Latest released the research study onGlobal Hematopoietic Stem Cell Transplantation Market, offers a detailed overview of the factors influencing the global business scope.Hematopoietic Stem Cell TransplantationMarket research report shows the latest market insights, current situation analysis with upcoming trends and breakdown of the products and services. The report provides key statistics on the market status, size, share, growth factors of theHematopoietic Stem Cell Transplantation Market. The study covers emerging players data, including: competitive landscape, sales, revenue and global market share of top manufacturers.

Top players in Global Hematopoietic Stem Cell Transplantation Market are:

Gilead Sciences Inc. (United States)

Thermo Fisher Scientific (United States)

PromoCell (Germany)

CellGenix Technologie Transfer GmbH (Germany)

Cesca Therapeutics Inc.(United States)

R&D Systems (United States)

Genlantis (United States)

Lonza Group Ltd.(Switzerland)

TiGenix N.V.(Belgium)

ScienCell Research Laboratories (United States)

Regen Biopharma Inc. (United States)

China Cord Blood Corp (Hong Kong)

CBR Systems Inc. (United States)

Free Sample Report + All Related Graphs & Charts @: https://www.advancemarketanalytics.com/sample-report/69543-global-hematopoietic-stem-cell-transplantation-market-1

Brief Overview on Hematopoietic Stem Cell Transplantation

Despite the increasing availability of smart antineoplastic therapies in recent years, Hematopoietic stem cell transplantation (HSCT) remains an optimal treatment modality for many hematologic malignancies. HSCT is one of a range of therapeutic options which is available to patients suffering from various diseases. It is a widely accepted treatment for many life-threatening diseases. The treatment is available to patients who suffer from refractory or relapsing neoplastic disease and non-neoplastic genetic disorders, as well as from chronic bone marrow failure. Hematopoietic stem cells are young or immature blood cells which are found to be living in bone marrow. These blood cells when matures in bone marrow very few enters into bloodstream. These cells that enter bloodstream are called as peripheral blood stems cells. Hematopoietic stem cells transplantation is the replacement of absent, diseased or damaged hematopoietic stem cells due to chemotherapy or radiation, with healthy hematopoietic stem cells.

Recent Development in Global Hematopoietic Stem Cell Transplantation Market:

In January 2019, Paul-Ehrlich Institute discovered important surface molecules supporting hematopoietic recovery after transplantation of blood stem cells. The protein C receptor on hematopoietic stem cell improves stem cell transplantation. Transplantation of blood stem cells (HSCTs) is an important treatment for the patients with hematopoietic disorders

Keep yourself up-to-date with latest market trends and changing dynamics due to COVID Impact and Economic Slowdown globally. Maintain a competitive edge by sizing up with available business opportunity in Hematopoietic Stem Cell Transplantation Market various segments and emerging territory.

Market Drivers

Market Trend

Market Challenges

Market Restraints:

Market Opportunities:

Region Included are: North America, Europe, Asia Pacific, Oceania, South America, Middle East & Africa

Country Level Break-Up: United States, Canada, Mexico, Brazil, Argentina, Colombia, Chile, South Africa, Nigeria, Tunisia, Morocco, Germany, United Kingdom (UK), the Netherlands, Spain, Italy, Belgium, Austria, Turkey, Russia, France, Poland, Israel, United Arab Emirates, Qatar, Saudi Arabia, China, Japan, Taiwan, South Korea, Singapore, India, Australia and New Zealand etc.

Enquire for customization in Report @: https://www.advancemarketanalytics.com/enquiry-before-buy/69543-global-hematopoietic-stem-cell-transplantation-market-1

Strategic Points Covered in Table of Content of Global Hematopoietic Stem Cell Transplantation Market:

Chapter 1: Introduction, market driving force product Objective of Study and Research Scope the Global Hematopoietic Stem Cell Transplantation market

Chapter 2: Exclusive Summary the basic information of the Global Hematopoietic Stem Cell Transplantation Market.

Chapter 3: Displaying the Market Dynamics- Drivers, Trends and Challenges of the Global Hematopoietic Stem Cell Transplantation

Chapter 4: Presenting the Global Hematopoietic Stem Cell Transplantation Market Factor Analysis Porters Five Forces, Supply/Value Chain, PESTEL analysis, Market Entropy, Patent/Trademark Analysis.

Chapter 5: Displaying the by Type, End User and Region 2013-2020

Chapter 6: Evaluating the leading manufacturers of the Global Hematopoietic Stem Cell Transplantation market which consists of its Competitive Landscape, Peer Group Analysis, BCG Matrix & Company Profile

Chapter 7: To evaluate the market by segments, by countries and by manufacturers with revenue share and sales by key countries in these various regions.

Chapter 8 & 9: Displaying the Appendix, Methodology and Data Source

Finally, Global Hematopoietic Stem Cell Transplantation Market is a valuable source of guidance for individuals and companies.

Data Sources & Methodology

The primary sources involve the industry experts from the Global Hematopoietic Stem Cell Transplantation Market including the management organizations, processing organizations, analytics service providers of the industrys value chain. All primary sources were interviewed to gather and authenticate qualitative & quantitative information and determine the future prospects.

In the extensive primary research process undertaken for this study, the primary sources Postal Surveys, telephone, Online & Face-to-Face Survey were considered to obtain and verify both qualitative and quantitative aspects of this research study. When it comes to secondary sources Companys Annual reports, press Releases, Websites, Investor Presentation, Conference Call transcripts, Webinar, Journals, Regulators, National Customs and Industry Associations were given primary weightage.

Get More Information: https://www.advancemarketanalytics.com/reports/69543-global-hematopoietic-stem-cell-transplantation-market-1

What benefits does AMA research study is going to provide?

Definitively, this report will give you an unmistakable perspective on every single reality of the market without a need to allude to some other research report or an information source. Our report will give all of you the realities about the past, present, and eventual fate of the concerned Market.

Thanks for reading this article; you can also get individual chapter wise section or region wise report version like North America, Europe or Asia.

About Author:

Advance Market Analytics is Global leaders of Market Research Industry provides the quantified B2B research to Fortune 500 companies on high growth emerging opportunities which will impact more than 80% of worldwide companies revenues.

Our Analyst is tracking high growth study with detailed statistical and in-depth analysis of market trends & dynamics that provide a complete overview of the industry. We follow an extensive research methodology coupled with critical insights related industry factors and market forces to generate the best value for our clients. We Provides reliable primary and secondary data sources; our analysts and consultants derive informative and usable data suited for our clients business needs. The research study enables clients to meet varied market objectives a from global footprint expansion to supply chain optimization and from competitor profiling to M&As.

Contact Us:

Craig Francis (PR & Marketing Manager)AMA Research & Media LLPUnit No. 429, Parsonage Road Edison, NJNew Jersey USA 08837Phone: +1 (206) 317 1218[emailprotected]

Connect with us athttps://www.linkedin.com/company/advance-market-analyticshttps://www.facebook.com/AMA-Research-Media-LLP-344722399585916https://twitter.com/amareport

View post:
Hematopoietic Stem Cell Transplantation Market is Stunning Worldwide Gaining Revolution in Eyes of Global Exposure - Owned

Bone Marrow Stem Cells Comments Off on Hematopoietic Stem Cell Transplantation Market is Stunning Worldwide Gaining Revolution in Eyes of Global Exposure – Owned | August 15th, 2020

Journalists received not one but three announcements this week from American Gene Technologies (AGT) touting the most promising potential cure for HIV in the world. But such claims amount to unjustified hype, advocates say. The experimental therapy has not yet been tested in humans andif it worksit could be years before its ready for clinical use.

AGT just received clearance from the Food and Drug Administration (FDA) to start the first Phase I human clinical trial of its genetically modified T-cell product, dubbed AGT103-T, which the company is developing in collaboration with researchers at the National Institute of Allergy and Infectious Disease.

From its research, AGT believes a cure is attainable and is now taking the significant step of testing in humans, the company announced in a press release. Added AGT founder and CEOJeff Galvin, I am confidentAGT103-Twill be an important step toward an eventual cure for HIV.

But advocates say such claims are not only premature, they are also harmful in giving people with HIV the false impression that a cure is around the corner.

AGTs public relations strategy preys on the emotions of people living with HIV and has a deleterious effect on the understanding of the cure field overall, Seattle advocate Michael Louella told POZ. They make their outrageous comments, and these are then picked up and believed to be certain truth. Any attempt to promote a more nuanced and better-grounded understanding of gene therapy or the clinical process becomes impossible.

Although HIV can be suppressed indefinitely with combination antiretroviral therapy, it has proved exceedingly difficult to cure because a so-called reservoir of latent virus can remain hidden from the drugs in resting immune cells. Only two people appear to have been cured after bone marrow transplants from donors with HIV-resistant stem cellsa procedure far too dangerous for people who dont have life-threatening blood cancer.

Nonetheless, researchers are exploring numerous cure strategies, ranging from flushing HIV out of resting cells to genetically engineering immune cells to make them resistant to the virus. Most experts expect that a combination approach will likely be needed to maintain durable control of HIV after stopping antiretroviral therapythe definition of a functional cure.

AGTs process involves collecting immune cells from a patient and selecting those cells that target HIV antigens. A harmless lentivirus vector is then used to insert genes into the HIV-specific CD4 T cells that disable CCR5 receptorswhich most strains of HIV use to enter cellsas well as genes involved in HIV replication. The genetically modified CD4 cells are then reinfused back into the same patient in a single dose. The entire process takes 11 days.

The company said it expects the approach will provide durable control of genetically diverse strains of HIV, including those that use a different receptor (known as CXCR4) to enter cells. The experimental therapy should work to remove infected cells from the body and decrease or eliminate the need for lifelong antiretroviral treatment, AGT claims.

Another company, Sangamo BioSciences, previously reported promising results from early studies using a different gene therapy technique (a zinc finger nuclease) to edit out CCR5 receptors from T cells. Although it did not cure HIV, some study participants saw a reduction in the size of their viral reservoir and a long-term increase in CD4 counts. More recently, Chinese researcher He Jiankui used yet another technique (CRISPR-Cas9) to disable the CCR5 gene in human embryos in an effort to protect them from HIV.

AGTs approach not only uses a different gene-editing method to disable CCR5, but it also selects CD4 T cells that target HIV and protects them from destruction by the virus, thereby helping the selected cells survive and avoiding the wasted effort of modifying cells that wont attack HIV.

A recent medical journal report described preclinical studies of the approach, which showed that it is feasible to manufacture the modified HIV-specific CD4 T cells. AGT claims that in laboratory studies, the product demonstrates the ability to clear itself of HIV when challenged with the virus and HIV-infected human cells. The company has not yet reported results from studies of the experimental therapy in animals.

These findings were used to support AGTs investigational new drug application to the FDA to allow the company to proceed with a Phase I study in human volunteers, which will be conducted in Baltimore and Washington, DC. Eligible participants must have been on antiretroviral therapy for one to three years, have an undetectable viral load, have a stable CD4 count above 500 and may not have any AIDS-defining conditions.

AGT expects to enroll the first participant in September, with the first infusion of genetically modified T cells to be administered in December. The company said it expects initial data by the end of the year.

But this will be far too soon to determine whether the altered T cells persist in the body or whether they can maintain long-term viral suppression after antiretroviral therapy is discontinued.

Saying AGT believes there is a high likelihood that participants in the upcoming trial will be cured is beyond outrageous and completely undermines informed consent because its an unethical inducement to participate [in trials], Richard Jefferys of the Treatment Action Group told POZ.

And its not based on a shred of evidence. To my knowledge, theres no humanized mouse data, no macaque dataits all theory, he continued. "I would hope that they pause to reconsider their PR strategy and broaden their consultation with stakeholders, including community-based advocates.

Click here for more news about HIV cure research.

Originally posted here:
Gene Therapy Cure Claims Are Premature, Advocates Say - POZ

Bone Marrow Stem Cells Comments Off on Gene Therapy Cure Claims Are Premature, Advocates Say – POZ | August 15th, 2020

INTRODUCTION

In recent years, a number of growth factors have been tested in clinical trials for a variety of therapeutic applications including bone regeneration and neovascularization of ischemic tissues. Despite early promising results, the results obtained in larger phase 2 trials have often not shown the expected benefit to patients (1, 2), with some having marked adverse effects (35). The Infuse bone graft, which consists of recombinant human bone morphogenetic protein-2 (rhBMP-2) soaked onto a collagen sponge at a dosage of 1.5 mg/ml, has received Food and Drug Administration approval for certain spinal, dental, and trauma indications and is in widespread clinical use. However, major complications and adverse effects have increasingly been attributed because of the off-label use of the product (3, 4). Clinically, the current delivery vehicle for BMP-2 is a collagen powder or sponge that has been shown to result in a large initial burst release, which contrasts with the expression profile observed during normal fracture repair where BMP expression increases until day 21, suggesting a need for slower and more sustained growth factor release profile (6, 7). Furthermore, because of the short half-life of the growth factor and the harsh fracture environment (5), supraphysiological dosages of BMP-2 are being delivered to elicit bone regeneration, which has been linked to adverse effects such as heterotopic ossification. Therefore, there is a clear clinical need to develop alternative strategies to deliver single or multiple growth factors to the site of injury with sustainable and physiologically relevant dosages such that repair is induced without these adverse effects.

A number of growth factors have been shown to be expressed at different phases of fracture healing, including vascular endothelial growth factor (VEGF) and BMPs. The coupled relationship in bone healing, both physical and biochemical, between blood vessels and bone cells has long been recognized (8, 9). During fracture healing, VEGF is released directly after injury and predominately drives the formation of the fracture hematoma (9). Inhibition of VEGF has been shown to disrupt the repair of fractures and large bone defects (1012). Despite this, VEGF delivery alone is often not sufficient to heal critically sized bone defects, which may be due to suboptimal dosing or the timing of VEGF release. Furthermore, VEGF does not appear to drive progenitor cell differentiation toward the chondrogenic or osteogenic lineage; therefore, combination therapies with BMPs have been developed in an attempt to accelerate the regeneration of large bone defects (9, 1318). During normal fracture healing, VEGF expression peaks around day 5/10 (19, 20) and then decreases, whereas BMP-2 expression increases constantly until day 21, suggesting a need for delivery systems that support the early release of VEGF and the sustained release of BMP-2 (6, 7, 19, 20). To this end, composite polymer systems have been used to deliver VEGF and BMP-2 in a sequential fashion (1518). The timed release of VEGF/BMP-2 was found to enhance ectopic bone formation (1618); however, in an orthotopic defect, no significant benefit was observed (17, 18). This may be due to the high dose of VEGF used in these studies (18), which has previously been shown to disrupt osteogenesis as a result of abnormal angiogenesis and vascular structure (8), or due to suboptimal growth factor release profiles from these constructs. This suggests that novel strategies are required for delivering low-dosage VEGF and BMP-2, with tight temporal control, to enhance vascularization and subsequent bone formation in orthotopic defects. Nanoparticles such as hydroxyapatite (HA) and laponite are known to be osteoinductive and have previously been shown to facilitate the adsorption and immobilization of proteins such as VEGF and BMP-2 because of the strong attraction between the nanoparticles and the growth factor (2123). This motivates the integration of these nanoparticles into regenerative implants to enable tight temporal control over the rate at which encapsulated growth factors are released into damaged tissue.

Processes such as angiogenesis are regulated not only by the temporal presentation of growth factors but also by spatial gradients of morphogens that regulate chemotactic cell migration. Using microfluidic devices (24, 25) or three-dimensional (3D) culture models (26, 27), it has been demonstrated that endothelial cell migration is mediated by gradients in VEGF. However, it is unclear whether incorporating gradients of VEGF into tissue-engineered scaffolds will enhance angiogenesis in vivo. Here, we used emerging multiple-tool biofabrication techniques (28) to deliver VEGF and BMP-2 with distinct spatiotemporal release profiles to enhance the regeneration of critically sized bone defects. To tune the temporal release of these morphogens from 3D printed constructs, we functionalized alginate-based bioinks with different nanoparticles known to bind these regulatory factors. Both the spatial position and temporal release of growth factor from the 3D printed implant determined its therapeutic potential. By slowing the release of BMP-2, it was possible to enhance bone formation in vivo within predefined positions of the implant. Furthermore, introducing spatial gradients of VEGF into 3D printed implants enhanced vascularization in vivo compared to controls homogenously loaded with the same total amount of growth factor. We also demonstrate accelerated large bone defect healing, with minimal ectopic bone formation, using 3D printed implants containing a spatial gradient of VEGF and spatially localized BMP-2.

To produce a printable bioink, various weight concentrations of methylcellulose were first added to RGD -irradiated alginate. Print fidelity (as measured by the filament spreading ratio) improved by increasing the methylcellulose content [see fig. S1 (A and B)]; however, the capacity to print multiple layers of material worsens because of the overly adhesive nature of the ink. For these reasons, a weight concentration of 2:1 (w/w) alginate to methylcellulose was chosen for all bioinks, as it substantially increased the print fidelity while allowing multiple layers of material to be accurately deposited.

To tune the temporal release profile of growth factor (here, VEGF), clay nanoparticles (22, 23, 29) or hydroxyapatite nanoparticles (nHA) (21) were added to the alginate-methylcellulose bioink. Adding methylcellulose to the alginate to produce a printable ink significantly increased the release of VEGF compared to that observed from alginate only [see fig. S1 (C and D)]. The addition of laponite, a clay-based nanoparticle, markedly slowed the release of VEGF (see fig. S1C), while the incorporation of nHA only had a small effect on growth factor release, producing a slightly more gradual release profile (see fig. S1D). This blend (alginate, methylcellulose, and nHA) will hereafter be referred to as the vascular bioink, as it allowed for the near complete release of VEGF over 10 days, mimicking that observed during normal fracture healing (19, 20). No laponite was included in this vascular bioink.

To demonstrate the utility of this vascular bioink, two strategies were compared to print implants containing a spatial gradient of VEGF (see fig. S1E). In the first, VEGF (100 ng/ml) was printed into the central 5-mm core of constructs 8 mm in diameter and 4 mm high, with a VEGF-free bioink used to print the periphery of the construct. In the second, VEGF (80 ng/ml) was printed into the center of the construct, and VEGF (20 ng/ml) was printed around the periphery of the implant. Control constructs containing a homogenous distribution of VEGF were also printed. One hour after printing, clear spatial differences in VEGF localization were observed in both gradient constructs, while roughly the same amount of protein was detected in the core and periphery of the homogenous VEGF control (see fig. S1F). Fourteen days after printing, a spatial gradient still existed in the construct that initially had all VEGF loaded into its central region, with no gradient observed in the other groups (see fig. S1G). This demonstrates that spatial gradients of growth factor can be maintained within constructs for at least 14 days after printing.

We next sought to assess whether depositing spatial gradients of VEGF within 3D printed polycaprolactone (PCL) implants would accelerate vascularization of the constructs in vivo. To this end, Homogenous VEGF, Gradient VEGF, and No VEGF constructs were implanted subcutaneously in the back of mice (see Fig. 1A), where the total amount of growth factor (25 ng) within the two VEGF-containing implants was constant. Two weeks after implantation, histological analysis of hematoxylin and eosin (H&E)stained samples revealed the presence of vessels in the Homogenous VEGF and Gradient VEGF groups; however, there were no obvious vessels present in the No VEGF group (see Fig. 1B). These vessels appeared mature, complete with smooth muscle actin (-SMA) and von Willebrand factor (vWF)stained walls and perfused with erythrocytes (see fig. S2A). The Homogenous VEGF constructs had vessels predominantly located in the periphery of the scaffold, with little to none present within the center of the scaffold. On the other hand, vessels were present both in the periphery and in the center of the Gradient VEGF group. Four weeks after implantation, all three experimental groups had mature vessels present (see Fig. 1C and fig. S2B). Similar to the Homogeneous VEGF group, the No VEGF group had vessels predominantly located in the periphery of the constructs, with little to none present within the center of the construct. When quantified, at both 2 and 4 weeks, there were significantly more vessels present in the Gradient VEGF group compared to both the Homogenous VEGF and No VEGF group (see Fig. 1D). There was significantly more vessels present in the periphery of the Gradient VEGF constructs at both 2 and 4 weeks in vivo compared to the other two experimental groups [see Fig. 1 (E and F)]. There was also a trend toward a larger number of vessels present in the center of the Gradient VEGF construct at 4 weeks compared to No VEGF (P = 0.09) and Homogenous VEGF (P = 0.1) groups (see Fig. 1F).

(A) Schematic of the 3D printed scaffold and experimental groups. Construct design (4 mm in diameter, 5 mm in height). H&E-stained sections of the three experimental groups at (B) 2 and (C) 4 weeks in vivo. Images were taken at 20. Arrows denote vessels. (D) Total number of vessels of the experimental groups at 2 and 4 weeks in vivo. Number of vessels present in the center versus the periphery at (E) 2 and (F) 4 weeks in vivo. **P < 0.01. Error bars denote SDs (n = 8 animals; n = 5 slices per animal). FBS, fetal bovine serum; pen/strep, penicillin/streptomycin.

Recognizing that a slower and more sustained release of BMP-2 could be beneficial for promoting osteogenesis (6, 7), we next sought to compare bone formation in vivo within implants with temporally distinct growth factor release profiles. To the base alginate-methylcellulose bioink (here termed the Fast BMP-2 Release bioink), laponite at varying w/w ratios of laponite to alginate were compared to determine the optimum ratio to generate a Slow BMP-2 Release bioink (see fig. S3). As there was little difference in the growth factor release profile from the different groups, a 6:1 alginate:laponite w/w ratio was chosen to minimize the amount of laponite in the bioink. The addition of laponite markedly slowed the in vitro release of BMP-2 from the bioink, resulting in a reasonable constant release of growth factor from day 7 to day 35 (see Fig. 2C). The addition of laponite also had no significant effect on the degradation rate of the bioink (Fig. 2B).

(A) Schematic of the experimental groups. Construct design (4 mm in diameter, 5 mm in height). MEM, alpha minimum essential medium. (B) Degradation of the two bioinks. (C) Cumulative release of BMP-2 of the fast release bioink versus the slow release bioink. (D) 3D reconstructions of the CT data for each group at 8 weeks. (E) CT analysis on total mineral deposition of each of the groups after 8 weeks in vivo. (F) CT analysis on the location of mineral deposition of each of the groups after 8 weeks in vivo. ***P < 0.001; error bars denote SDs (n = 8 animals). (G) Goldners trichromestained sections of both groups after 8 weeks in vivo. Images were taken at 20. White arrows denote developing bone tissue, and black arrows denote blood vessels. (H) Quantification of the amount of new bone formation per total area. Error bars denote SDs; **P < 0.01 (n = 8 animals, n = 6 slices per animal).

To assess whether slow and sustained release of BMP-2 would enhance ectopic bone formation in vivo, Fast BMP-2 Release (laponite) and Slow BMP-2 Release (+laponite) bioinks were mixed with bone marrowderived mesenchymal stem cells (BMSCs), deposited within 3D printed scaffolds, and then implanted subcutaneously in the back of mice (see Fig. 2A). Seeding these bioinks with MSCs was used to test their potential for promoting osteogenesis in an ectopic location. BMP-2 was specifically localized around the periphery of the implant. This pattern of growth factor presentation was chosen to test the capacity of the printed implants to spatially localize bone formation in vivo (note that the geometry of the implant is the same as that which will be used in the segmental defect study below, with the BMP-2 localized to the periphery of the implant such that bone would only form along the cortical shaft of the damaged limb rather than throughout). Eight weeks after implantation, there was significantly more mineral within the Slow BMP-2 Release group compared to the Fast BMP-2 Release group [see Fig. 2 (D and E)]. Microcomputed tomography (CT) reconstructions revealed that the mineral was preferentially deposited around the periphery of the constructs where the BMP-2 was localized [see Fig. 2 (D and F)]. Histological staining further verified this finding, with positive staining for new bone seen predominantly in the periphery of both groups (see Fig. 2G, denoted by white arrows). Quantification revealed that the Slow BMP-2 Release constructs had significantly more new bone formation per total area of construct (see Fig. 2H).

We next sought to assess whether the delayed release of BMP-2 from printed constructs containing spatial gradients in VEGF would enhance angiogenesis and bone formation within critically sized bone defects. To this end, VEGF gradient only, BMP-2 gradient only, and Composite (VEGF+BMP-2 gradient) constructs were printed and implanted in a 5-mm rat femoral defect (see Fig. 3A) and compared to an empty defect.

(A) Schematic of the 3D printed experimental groups including key features of the developed bioinks and the segmental defect procedure. Construct design (4 mm in diameter, 5 mm in height). (B) CT angiography representative images of vessel diameter. Red arrows denote leaky blood vessels denoted by pools of contrast agent. Quantification on (C) total vessel volume, (D) average vessel diameter, and (E) connectivity for all groups after 2 weeks in vivo. *P < 0.05 and **P < 0.01; error bars denote SDs (n = 9 animals). (F) Immunohistochemical staining of nuclei (blue), vWF (red), and SMA (green) of the experimental groups at 2 weeks after implantation. Images were taken at 40 and 63. Yellow arrows denote vessels with SMA and vWF dual staining; white arrows denote slightly less mature vessels with only vWF positive staining.

Two weeks after implantation, CT angiography was used to quantify and visualize the early vascular network that had formed within the defect site. 3D reconstructions revealed that vascular networks had formed in all four experimental groups (see Fig. 3B). When quantified, there was a significant increase in vessel volume in the Composite group compared to the VEGF gradient group (see Fig. 3C). There was also a significant increase in average vessel thickness in the BMP-2 gradient and Composite groups compared to the VEGF gradient group (see Fig. 3D). Although there was no significant difference in the connectivity of the vessels, there was a trend (P = 0.1) toward increased connectivity in the Composite group compared to the VEGF gradient group (see Fig. 3E). 3D reconstructions also revealed the presence of primitive immature blood vessels depicted by large globules of contrast agent (denoted by the red arrows in Fig. 3B). There appeared to be fewer primitive blood vessels present in the Composite group than the other three experimental groups. This was further verified by SMA and vWF staining, which revealed a larger number of vessels with only positive vWF-stained walls in the Empty and VEGF gradient groups (see Fig. 3F, denoted by white arrows). On the other hand, there were predominately more mature vessels with SMA and vWF-stained walls in both the BMP-2 gradient and Composite groups (see Fig. 3F, denoted by yellow arrows). Note that the differences in angiogenesis seen between the VEGF gradient and Composite groups (same amount of VEGF in both groups) could at least partially be explained by looking at the VEGF release profile from both groups (see fig. S4). The addition of the osteoinductive ink around the implant periphery significantly reduced the VEGF release rate from construct into the media, with a more linear release of growth factor over time.

Two weeks after surgery, defects within the Empty group were filled with a fibrous tissue (see Fig. 4A). In contrast, positive staining for cartilage and new bone deposition was observed in the BMP-2 gradient and Composite groups, suggesting that new bone was forming at least partially via endochondral ossification. When quantified, there was a trend toward increased cartilage development (red staining in Safranin O images) in both the BMP-2 gradient (P = 0.12) and Composite (P = 0.18) groups compared to the Empty (see Fig. 4B). No significant differences in bone formation was observed between any of the groups at week 2; however, the CT reconstructions showed mineralized calluses beginning to form in the BMP-2 gradient and Composite groups, which was less evident in the Empty and VEGF gradient groups [see Fig. 4 (C and D)].

(A) H&E- and Safranin Ostained sections of all groups after 2 weeks in vivo. Images were taken at 20. DB denotes cartilage undergoing endochondral ossification to become developing bone, and B denotes positive new bone tissue. Quantification of the amount of (B) bone formation and (C) developing bone per total area. Error bars denote SDs (n = 9 animals). (D) CT reconstructed images of the defect site.

Next, CT analysis was used to visualize and quantify bone formation within the defects at 4, 8, 10, and 12 weeks after implantation. Compared to the Empty group, there were significantly higher levels of new bone formation in the Composite group as early as 8 weeks after implantation [see Fig. 5 (A and B)]. A consistent pattern of healing was observed in the Composite group, with bone forming down through the PCL scaffold framework (see Fig. 5A and fig. S5). After 10 weeks of implantation, significantly higher levels of bone formation was observed in the BMP-2 gradient and Composite groups compared to the Empty group. By 12 weeks, all three experimental groups contained significantly higher levels of new bone compared to the Empty group. Twelve weeks after implantation, bone density mapping revealed that the new bone formed in the experimental groups consisted of a dense cortical-like bone present around the periphery of defect, comparable to the adjacent native bone (1200 mg HA/cm3) (see Fig. 5C). Quantitative densitometry analysis revealed no significant difference in the average density (mg HA/cm3) of the new bone that did form between any of the groups over the 12 weeks (see Fig. 5D).

(A) Reconstructed in vivo CT analysis of bone formation in the defects. (B) Quantification of total bone volume (mm3) in the defects at each time point. (C) Representative images of CT bone densities in the defects at 12 weeks halfway through the defect (scale bar, 1 mm throughout). (D) Average bone density (mg HA/cm3) in the defects at each time point. (E) Outline of ROI bone volume analysis including definitions of core, annulus, and heterotopic regions. (F) Total bone volume (mm3) in each region at 12 weeks. **P < 0.01, ***P < 0.001, and ****P < 0.0001; error bars denote SDs (n = 9 animals).

To assess the levels of heterotopic bone formation, region of interest (ROI) bone volume analysis was performed on the week 12 reconstructions. The total bone volume was quantified in the core, annulus, and heterotopic regions of the defect (see Fig. 5E). In all three experimental groups, bone preferentially formed in the annulus of the defect, with little ectopic bone formation (see Fig. 5F). All three experimental groups had significantly higher total bone volume in the annulus of the defect compared to the Empty annulus, with the highest total bone volume present in the Composite group.

We next sought to assess the nature of new bone tissue being formed using histological staining. Goldners trichrome staining revealed predominantly fibrous tissue formation, similar to what was seen previously at 2 weeks, in the Empty group (see Fig. 6A). There was positive staining for new bone, complete with marrow cavities, in all three experimental groups at 12 weeks after implantation. When quantified, there was significantly more bone found in all three experimental groups compared to the Empty group (see Fig. 6B). There were also significantly higher amounts of bone marrow present in the Composite group compared to the Empty group (see Fig. 6C). As observed in the CT 3D reconstructions, it is clear that the bone is forming down through the PCL scaffold framework, specifically in the Composite group. Safranin O staining revealed the presence of cartilage in all three experimental groups after 12 weeks, demonstrating that bone is continuing to develop via endochondral ossification. When quantified, there was significantly more cartilage present in the Composite group compared to all other groups at this time point (see Fig. 6D).

(A) Goldners trichrome and Safranin Ostained sections of all groups after 12 weeks in vivo. Images were taken at 20. BM denotes bone marrow. PCL denotes areas where the PCL frame was. DB denotes cartilage undergoing endochondral ossification to become new bone, and B denotes positive bone tissue. Quantification of the amount of (B) bone formation, (C) bone marrow, and (D) developing bone per total area. Error bars denote SDs. *P < 0.05, **P < 0.01, and ****P < 0.0001 (n = 9 animals).

Despite the tremendous potential of growth factor delivery, the results obtained in larger clinical trials have not always shown the expected benefit to patients (2), with some studies reporting marked adverse effects (35). The reasons for this are multifaceted, from the delivery methods to the supraphysiological dosages needed to elicit a therapeutic effect and the costs and adverse effects attached to these high doses. This study presents a novel alternative approach for spatiotemporally controlled delivery of growth factors. We developed a range of nanoparticle-functionalized bioinks to precisely control the temporal release of growth factors from 3D printed implants. Using multiple tool biofabrication techniques, we were able to print constructs containing spatiotemporal gradients of growth factors, which allowed for controlled tissue regeneration without the need for supraphysiological dosages. Specifically, the appropriate patterning of VEGF enhanced angiogenesis in vivo and, when coupled with defined BMP-2 localization and release kinetics, enhanced large bone defect healing with little heterotopic bone formation.

Alginate hydrogels are commonly used for bone tissue engineering, with a number of studies demonstrating the bone regeneration potential of RGD functionalized and -irradiated alginate (3033), making it a promising base bioink for the 3D bioprinting of osteogenic implants. However, one drawback to using RGD -irradiated alginate as a bioink is its low viscosity. It is imperative when printing multilayered structures that the bioink have appropriate rheological properties to prevent collapsing or sagging of the printed structure. The addition of methylcellulose to alginate-based bioinks was found to have a significant effect on both printability and the rate of growth factor release. The addition of methylcellulose has previously been shown to substantially increase the print fidelity of an alginate base bioink (22, 34, 35), although typically using higher concentrations than the one used in this study. Adding methylcellulose also accelerated the rate of growth factor release. This was previously seen with albumin release from alginate-methylcellulose beads (36). Such a polymeric network is at least partially defined by physical entanglements between the alginate or methylcellulose chains. As methylcellulose is characterized by high swellability, when the alginate/methylcellulose bioink is exposed to the medium, it swells rapidly, resulting in accelerated growth factor release from the bioink. The addition of methylcellulose may also have neutralized the charge on the alginate, which would also influence growth factor release kinetics. In contrast, the addition of nanoparticles, and, in particular, laponite, slowed the release of growth factor from the inks. Both nHA and laponite have previously been shown to facilitate with the adsorption and immobilization of VEGF within a hydrogel due to the strong attraction between the nanoparticles and the growth factor (2123). The stronger association between growth factors and laponite can be linked to the physiochemical properties of these particles (22, 29). These disc-shaped particles [typically 25 nm in diameter and 1 nm in thickness (37)] are characterized by a highly negatively charged face and a positively charged rim (22), with a zeta potential of 61 mV (as determined by the manufacturer). This allowed the positively charged growth factors such as VEGF to form strong electrostatic bonds with the negatively charged face of the nanoparticles (22). In contrast, the nHA nanoparticles used in this study, which we have previously shown to have a zeta potential of around 5 mV (38), would form a slightly weaker electrostatic bond with the VEGF. The addition of laponite to bioinks has also previously been shown to influence their mechanical properties (37). While we did not directly assess whether the addition of laponite influenced the stiffness of our ink, we did observe that it had no effect on their degradability, and on the basis of w/w ratio used in this study, we do not believe it had marked effects on mechanical properties such as matrix stiffness. Previous studies have shown that when using high concentrations of alginate (similar to that used in this study), the addition of laponite does not markedly affect the rheological properties of the bioink (37). However, future studies should investigate the overall mechanical properties of a bioink, as this may also influence its osteogenic potential (39). A potential limitation of laponite is that the strong electrostatic bond can limit the amount of growth factor released from a delivery system in the short-medium term (22). In this study, by tuning the ratio of laponite to alginate, it was possible to engineer bioinks that released most of their loaded protein over 35 days. Therefore, using specifically selected nanoparticles, it is possible to develop bioinks that support growth factor release profiles spanning days to weeks.

Using multiple-tool biofabrication, we demonstrated that distinct growth factor gradients can be established and maintained over time and that incorporating these gradients into printed implants can enhance sprouting angiogenesis in vivo. The process of sprouting angiogenesis begins with the selection of a distinct site on the mother vessel where sprout formation is initiated. This distinct site is referred to as the tip cell, and as the new sprout elongates, branches, and connects with other sprouts, the selection process for the tip cell is constantly reiterated (40). Previous studies have shown in the early postnatal retinas that tip cell migration depends on a gradient of VEGF-A and its proliferation is regulated by its concentration (40, 41). Therefore, the increase in vessel infiltration observed in VEGF gradient implants can possibly be attributed to tip cell migration and proliferation toward the areas of high VEGF concentration (40, 41). In contrast, when VEGF was homogenously distributed within the implant, there was less of a chemotactic effect, resulting in lower levels of vessel infiltration into the center of the construct.

When this bioprinting strategy was used to deliver both growth factors within a large bone defect, there was a significant increase in vessel infiltration within implants containing both a VEGF gradient and BMP-2 compared to those containing VEGF alone. Although it has been shown that delivery of BMP-2 alone can enhance new blood vessel formation within bone defects (42, 43), previous studies have not reported a benefit to delivering both growth factors to the defect site (17, 18). The finding that the laponite-functionalized bioink around the periphery of the implant was slowing the release of VEGF from the implant may partially explain the higher levels of vessel infiltration observed within the composite implant, with the slower VEGF release profile being perhaps more conducive to angiogenesis within the orthotopic environment. Somewhat unexpectedly, despite enhancing overall levels of bone formation, VEGF delivery alone did not increase early vessel infiltration into the implant. Note that orthotopic hematomas, generated by the surgical procedure, would have provided all defects with a source of endogenous chemotactic, angiogenic, and mitogenic growth factors (17). This may have mitigated the effect that an implant containing a VEGF gradient alone had on early angiogenesis.

3D printed implants containing spatial gradients of VEGF, coupled with defined BMP-2 localization, enhanced large bone defect healing with little heterotopic bone formation. Critically, this increase in bone healing was achieved using very low concentrations of exogenous growth factors. The concentration of VEGF used in this study was substantially less (80 to 160 times less) than previous studies (17, 18). Achieving therapeutic benefits with these low concentrations of growth factors is important for multiple reasons, not least of which is the observation that high concentrations of VEGF have been previously shown to disrupt osteogenesis as the result of abnormal angiogenesis and vascular structure (8). Furthermore, the concentrations of BMP-2 used here are at least an order of magnitude lower than that used previously to repair similar sized defects in a rat femoral defect model (28, 31). Repair in these studies is typically associated with a substantial amount of heterotopic bone formation (28, 31). Directly comparing to previous work in our lab, which used a clinically relevant BMP-2 dose in the same defect model (28), the results from this study exhibited substantially less heterotrophic bone formation [10% versus 50% (28) of total bone volume]. Although we did not observe full bone bridging after 12 weeks, new bone was still being formed via the process of endochondral ossification at 12 weeks, suggesting that regeneration was still proceeding. Allowing some level of physiological loading earlier in the healing process would likely have further accelerated regeneration (44). Together, the results from this study demonstrate the potential of 3D printing morphogen gradients for controlled tissue regeneration (with minimal heterotopic bone formation) without the need of supraphysiological dosages.

The translation of tissue engineering concepts from bench to bedside is a challenging, expensive, and time-consuming process. Numerous products have not made it past phase 2 trials, as they have not shown the expected benefit in patients (1, 2), while others have been associated with marked adverse effects (35). Here, we describe a previously unidentified approach for spatiotemporally defined growth factor delivery and demonstrate a potential clinical utility in the regeneration of large bone defects or the increased vascularization of any 3D printed construct. Proof-of-concept studies in small animals established the potential of these growth factor loaded bioinks for inducing enhanced angiogenesis and bone regeneration without the need for supraphysiological dosages. The benefit of this precise localization of growth factors in both time and space is that it allows for tightly controlled angiogenesis and new tissue formation, thereby reducing off-target effects. It is envisioned that this platform technology could be applied to the controlled regeneration of numerous different tissue types.

This study was designed to test whether the delayed release of BMP-2 from bioprinted constructs containing spatial gradients in VEGF will first enhance vascularization and sequentially enhance orthotopic bone regeneration. All animal experiments were conducted in accordance with the recommendations and guidelines of The Health Products Regulatory Authority, the competent authority in Ireland responsible for the implementation of Directive 2010/63/EU on the protection of animals used for scientific purposes in accordance with the requirements of the Statutory Instrument no. 543 of 2012. Subcutaneous mouse experiments were carried out under license (AE 19136/P069), and the rat femoral defect experiments were carried out under license (AE19136/P087) approved by The Health Products Regulatory Authority and in accordance with protocols approved by the Trinity College Dublin Animal Research Ethics Committee. The n for rodent models were based on the predicted variance in the model and was powered to detect 0.05 significance. For the subcutaneous surgeries, constructs were implanted in a balanced manner, such that each group contained an implant placed at each of the subcutaneous locations and samples for both surgical procedures were randomly distributed across the operated animals. For the rat surgeries, three rats from the empty group died from unforeseen complications and so were removed from the n number at the 12-week time point. One rat from the BMP-2 gradient group at 12-week time point was also removed, as it was deemed a statistical outlier using the Grubbs test.

Lowmolecular weight sodium alginate (58,000 g/mol) was prepared by irradiating sodium alginate (196, 000 g/mol; Protanal LF 20/40, Pronova Biopolymers, Oslo, Norway) at a gamma dose of 50,000 gray, as previously described (45). RGD-modified alginate was prepared by coupling the GGGGRGDSP to the alginate using standard carbodiimide chemistry. All bioinks were prepared by dissolving the RGD -irradiated alginate in growth medium, which consisted of alpha minimum essential medium (MEM) (GlutaMAX; Gibco, Biosciences, Ireland), 10% fetal bovine serum (FBS) (EU Thermo Fisher Scientific), penicillin (100 U/ml; Sigma-Aldrich), and streptomycin (100 g/ml; Sigma-Aldrich) (pen-strep) to make up a final concentration of 3.5% (w/v).

3D bioplotter from RegenHU (3DDiscovery) was used to evaluate the printability of the generated bioinks. The printability of varying the w/w ratio (2:1, 1:1, and 1:2) of methylcellulose to alginate was evaluated by measuring the spreading ratio as previously described (39)Spreading Ratio=Printed Filament DiameterActual Needle Diameter

To establish whether increasing the viscosity of the bioink influences growth factor release, methylcellulose (Sigma-Aldrich) was also added at ratio of 1:2 (w/w) to a 3.5% alginate solution of RGD -irradiated alginate. To establish whether the addition of clay-based particles to the bioink could further tailor the growth factor release profile of the bioinks, a 3.5% RGD -irradiated alginate solution was made, and either methylcellulose (2:1) (w/w) or a combination of both methylcellulose and laponite (Laponite XLG, BYK Additives & Instruments, UK) (6:3:1) (w/w) was added.

To establish whether the addition of nHA to the alginate would facilitate the adsorption and immobilization of growth factors within the hydrogel due to their strong electrostatic attraction between nHAs, three bioinks were tested (21). nHAs were prepared following a previously described protocol (46). A 3.5% RGD -irradiated alginate solution was made, and either methylcellulose (1:2) (w/w) or a combination of methylcellulose and nHA (2:1:2) (w/w) particles was added.

For all the growth factor release studies, VEGF (100 ng/ml; Gibco Life Technologies, Gaithersburg, MD, USA) was added to the solutions using dual-syringe approach, before precross-linking with 60 mM CaSO4 to make the bioinks as previously described (39). All constructs were cultured in growth medium in normoxic conditions, and media from each sample were changed bi-weekly. For VEGF release study, medium samples were taken (days 0, 3, 5, and 10) and snap-frozen at 80C. Hydrogels were also snap-frozen at 80C on day 0 to quantify the concentration of growth factor present in the constructs directly after printing.

To demonstrate the utility of the vascular bioink, two strategies were compared to print implants containing a spatial gradient of VEGF. The vascular bioink was prepared, cross-linked with 60 mM CaSO4, and printed to generate three experimental groups: (i) Homogenous VEGF. Bioink loaded with VEGF (100 ng/ml) was used to print constructs 8 mm in diameter and 4 mm high. (ii) Gradient 1. Bioink loaded with VEGF (100 ng/ml) was used to print a central 5-mm core with a VEGF-free bioink printed around the periphery of the 8-mm-diameter construct. (iii) Gradient 2. VEGF (80 ng/ml) was printed into the core, and VEGF (20 ng/ml) was printed into the periphery. Postprinting constructs were cross-linked again in a bath of 100 mM CaCl2 for 1 min. Constructs were cultured in growth medium in normoxic conditions for 14 days in vitro. The center and periphery of each construct were separated by coring out the center from the periphery of the scaffold and then snap-frozen at 80C, 1 hour after printing, and after 14 days in vitro.

To investigate whether the addition of laponite can tailor the growth factor release profile over a long culture period, a base bioink (Fast BMP-2 Release) and a laponite bioink (Slow BMP-2 Release) were compared. For both growth factor release profiles, a dual-syringe approach was used to deliver BMP-2 (200 ng/ml; PeproTech, UK) to the solutions before precross-linking with 60 mM CaSO4 to make the bioinks. These were printed into a 100 mM CaCl2 soak agarose mold to generate final constructs of 6 mm by 6 mm high. In addition to comparing the growth factor release profile of the two bioinks, the degradation rate of the bioinks was also investigated. These scaffolds were cultured in normoxic conditions for up to 35 days and media from each sample were changed weekly. For BMP-2 release study, medium samples were taken (days 0, 5, 7, 14, 21, and 35) and snap-frozen at 80C. Printed hydrogels were also snap-frozen at 80C on day 0 to quantify the concentration of growth factor present in the constructs directly after printing. For the degradation study, samples were washed and snap-frozen at 80C and each time point (days 0, 5, 7, 14, and 21). Samples were lyophilized by placing the samples in a freeze dryer (FreeZone Triad, Labconco, Kansas City, USA). Each sample was then weighed using an analytical balance (Mettler Toledo, XS205).

An enzyme-linked immunosorbent assay was used to quantify the levels of VEGF and BMP-2 (Bio-Techne, MN, USA) released by the alginates. The alginate samples were depolymerized with 1 ml of citrate buffer (150 mM sodium chloride, 55 mM sodium citrate, and 20 mM EDTA in H2O) for 15 min at 37C. The cell culture media and depolymerized alginate samples were analyzed at the specific time points detailed above. Assays were carried out as per the manufacturers protocol and analyzed on a microplate reader at a wavelength of 450 nm.

BMSCs were obtained from the femur of a 4-month-old porcine donor as previously described (47). All expansion was conducted in normoxic conditions, expanded in growth medium where the medium was changed twice weekly. Cells were used at the end of passage 3.

A 3D bioplotter from RegenHU (3DDiscovery) was used to print all of the scaffolds. Using a 30-gauge needle, constructs of 4 mm 5 mm high with both lateral and horizontal porosity and a fiber spacing of 1.2 mm were printed with PCL (Cappa, Perstop). The printing parameters of the PCL were as follows: temperature of thermopolymer tank (69C), temperature of thermopolymer head (72C), pressure (1 bar), screw speed (30 rpm), and feed rate (3 mm/s). Scaffolds were sterilized using ethylene oxide sterilization before hydrogel printing.

For the VEGF gradient study, the vascular bioink was prepared, cross-linked with 60 mM CaSO4, and printed within the PCL framework to generate three experimental groups: (i) No VEGF, bioink not loaded with VEGF; (ii) Homogenous, bioink loaded with VEGF (100 ng/ml) deposited (25 ng per construct) throughout the construct; and (iii) Gradient, bioink loaded with VEGF (500 ng/ml) deposited in the center (25 ng per construct) and VEGF-free bioink deposited on the outside (see Fig. 1A). Postprinting constructs were cross-linked again in a bath of 100 mM CaCl2 for 1 min.

For the BMP-2 release study, both a fast and slow release bioink were prepared and using the dual syringe approach, porcine MSCs were (2 106/ml) mixed to both bioinks to have an overall seeding density of 500 105 porcine MSCs/construct before being cross-linked with 60 mM CaSO4. Both bioinks were printed within the PCL framework to generate two experimental groups: (i) Fast release, fast release bioink loaded with BMP-2 (2 g/ml; 0.5 g per construct) deposited only in the periphery with the fast release bioink not loaded with BMP-2 in the center; and (ii) Slow release, slow release bioink loaded with BMP-2 (2 g/ml; 0.5 g per construct) deposited only in the periphery with the fast release bioink not loaded with BMP-2 in the center (see Fig. 2A). Postprinting constructs were cross-linked again in a bath of 100 mM CaCl2 for 1 min.

For the rat femoral defect, the vascular bioink, the osteoinductive bioink, and a base bioink (3.5% RGD -irradiated alginate and 1.75% methylcellulose) were prepared, cross-linked with 60 mM CaSO4, and printed within the PCL framework to generate three experimental groups: (i) VEGF Gradient, the vascular bioink loaded with VEGF (500 ng/ml) in the center of the implant and base bioink in the periphery; (ii) BMP-2 gradient, the osteoinductive bioink loaded with BMP-2 (10 g/ml) in the implant periphery (2 g per construct), with the base bioink in the center; and (iii) Composite (VEGF+BMP-2), the osteoinductive bioink in the periphery with the vascular bioink in the center (see Fig. 3A). Postprinting constructs were cross-linked again in a bath of 100 mM CaCl2 for 1 min.

Subcutaneous surgeries were performed on 20 8-week-old female BALB/c OlaHsd-Foxn 1nu nude mice (12 mice for the VEGF gradient study and 8 for the BMP-2 gradient study) (Envigo, Oxon, UK) as previously described (47). Scaffolds were 3D printed the morning of surgeries and implanted that day. Constructs were implanted in a balanced manner, such that each group contained an implant placed at each of the two subcutaneous locations and samples were randomly distributed across the operated animals.

For the rat segmental surgery, 72 12-week-old F344 Fischer male rats (Envigo, Oxon, UK) were anesthetized in an induction box using a mix of isoflurane and oxygen, initially at a flow rate of isoflurane of 5 liters/min to induce, followed by ~3 liters/min to maintain anesthesia. Once anesthetized, the animal was transferred to a heating plate that was preheated to 37C and preoperative analgesia was provided by buprenorphine (0.03 mg/ml). Surgical access to the femur was achieved via an anterolateral longitudinal skin incision and separation of the hindlimb muscles, the vastus lateralis, and biceps femoris. The femoral diaphysis was exposed by circumferential elevation of attached muscles, and the periosteum was removed. Before the creation of the defect, a PEEK plate was fixed to the anterolateral femur and was held in position using a clamp. Holes were created in the femur with a surgical drill using the plate as a template. Screws were then inserted into the drill holes in the femur to maintain the fixation plate in position. A 5-mm segmental defect was created using an oscillating surgical saw under constant irrigation with sterile saline solution. In the test groups, a scaffold was placed in the defect after a thorough washout of the surgical site. In the case of the empty defect group, the gap between bone ends was left empty. Soft tissue was accurately readapted with absorbable suture material. Closure of the skin wound was achieved using suture material and tissue glue.

Eight weeks after surgery, the BMP-2 gradient scaffolds were extracted and incubated in paraformaldehyde for 24 hours before being imaged via CT scans on a MicroCT42 (Scanco Medical, Brttisellen, Switzerland) as previously described (47).

Two weeks after surgery, 24 rats underwent a vascular perfusion protocol developed by Daly et al. (28). Briefly, the rat was sacrificed using CO2 asphyxiation, and the thoracic cavity was opened to insert a 20-gauge needle through the left ventricle of the heart. The inferior cava was cut and solutions of heparin (25 U/ml), and then, phosphate-buffered saline (PBS) was perfused through the vasculature using a peristaltic pump (Masterflex, Cole-Parmer, Vernon Hills, IL, USA) until the vasculature system was completely flushed clear. A solution of 10% formalin was then perfused for 5 min. Animals received a final perfusion of 20- to 25-ml radiopaque contrast agent MICROFIL (Flow Tech, Carver, MA, USA) and were left at 4C overnight. Explants were extracted and incubated in PBS for 24 hours before being imaged via CT scans on a MicroCT42 (Scanco Medical, Brttisellen, Switzerland) at 70 kVp, 113 A, and a 10-m voxel size. The volume of interest (VOI) was determined by positioning a 5-mm circle around the cross section of the femur with an overall length of 6.26 mm. MICROFIL has the same threshold as bone mineral, and therefore, to segment perfused vasculature from mineralized tissue within each construct, two scans were analyzed: calcified construct versus decalcified construct. The calcified constructs were scanned and postprocessed using a threshold value that accurately depicted both the mineral content and the vessel volume by visual inspection of the 2D grayscale tomograms (Scanco Medical MicroCT42). Noise was removed using a low-pass Gaussian filter (sigma = 1.2, support = 2), and a global threshold of 210 was applied. Next, samples were decalcified in EDTA (15 weight %, pH 7.4) for 2 weeks with the decalcification solution replaced daily (decalcified constructs). After 2 weeks, these decalcified constructs were scanned using the same settings and postprocessed at the same threshold as the calcified constructs to determine mineral content. Mineralized tissue content was determined by subtracting the bone volume of the decalcified scans from the calcified scans. Next, the decalcified scans were postprocessed at a threshold of 99 that accurately depicted just the vessel volume upon visual inspection of the 2D grayscale tomograms.

CT scans were performed on the rats using a Scanco Medical vivaCT 80 system (Scanco Medical, Bassersdorf, Switzerland). Rats (n = 9) were scanned at 4, 8, 10, and 12 weeks after surgery to assess defect bridging and bone formation within the defect. First, anesthesia was induced in an induction box using a mix of isoflurane and oxygen, initially at a flow rate of isoflurane of 5 liters/min to induce, followed by ~3 liters/min to maintain anesthesia. Next, the rats were placed inside the vivaCT scanner, and anesthesia was maintained by isoflurane-oxygen throughout the scan. Next, a radiographic scan of the whole animal was used to isolate the rat femur. The animals femur was aligned parallel to the scanning field of view to simplify the bone volume assessments. Scans were performed using a voltage of 70 kVp and a current of 113 A. A Gaussian filter (sigma = 0.8, support = 1) was used to suppress noise, and a global threshold of 210 was applied. A voxel resolution of 35 m was used throughout. 3D evaluation was carried out on the segmented images to determine bone volume and density and to reconstruct a 3D image. Bone volume and bone density in the defects were quantified by measuring the total quantity of mineral in the central 130 slices of the defect. To differentiate regional differences in bone formation, three VOIs were created. Concentric 2 mm, 4 mm, and 10 mm were aligned with the defect and used to encompass bone formation. The VOIs were aligned using untreated native bone along the femur. The core bone volume was quantified from the inner 2-mm VOI. The annular bone volume was quantified by subtracting the 2-mm VOI from the 4-mm VOI. Ectopic bone volume was quantified by subtracting the 4-mm VOI from the 10-mm VOI. The bone volume percentages for each region were then calculated by dividing the corresponding bone volume (i.e., bone volume in the annulus) by the total bone volume in the defect. The bone volume and densities were then quantified using scripts provided by Scanco.

For segmental defect samples, all constructs that were not being processed for vascular-CT imaging, were decalcified in Decalcifying Solution-Lite (Sigma-Aldrich) for 1 week before tissue processing. Once decalcified, all samples were dehydrated and embedded in paraffin using an automatic tissue processor (Leica ASP300, Leica). All samples were sectioned with a thickness of 8 m using a rotary microtome (Leica Microtome RM2235, Leica). Sections were stained with H&E for vessel infiltration, Safranin O to assess sulphated glycosaminoglycans (sGAG) content, and Goldners trichrome for bone formation. Quantitative analysis was performed on multiple H&E-stained slices, whereby vessels (positive staining for endothelium and erythrocytes present within the lumen), were counted on separate sections taken throughout each construct and averaged for each construct. Safranin O sections were evaluated for new developing bone (positive sGAG content). Massons trichromestained sections were evaluated for new bone formation. The percentage of developing bone, new bone, and marrow per total area of construct was measured in separate sections with the Deconvolution ImageJ plugin.

Immunofluorescence analysis was used to detect -SMA and vWF as previously described (47). Briefly, following blocking step, sections were then incubated overnight at +4C with goat polyclonal -SMA (1:250; ab21027, Abcam) in PBS with 3% of donkey serum (w/v) and 1% bovine serum albumin (BSA). After three washing steps with PBS containing 1% w/v BSA, the sections were incubated with Alexa Fluor 488 donkey anti-goat secondary antibody (1:200; ab150129, Abcam) for 1 hour at room temperature in the dark. The samples were washed three times in PBS with 1% w/v BSA, and the slides were then incubated overnight at +4C with rabbit polyclonal vWF antibody (1:200; ab6994, Abcam) in PBS with 3% of donkey serum (w/v) and 1% BSA (all from Sigma-Aldrich). After three washing steps with PBS and 1% w/v BSA, the sections were incubated with Alexa Fluor 647 donkey anti-rabbit secondary antibody (1:200; ab150075, Abcam) for 1 hour at room temperature in the dark. Last, samples were washed three times with PBS and 1% w/v BSA, and the sections were mounted using 4,6-diamidino-2-phenylindole mounting media (Sigma-Aldrich). Fluorescence emission was detected using a confocal laser scanning microscopy (Olympus FluoView 1000).

Results were expressed as means SD. Statistics was performed using the following variables: (i) When there were two groups and one time point, a standard two-tailed t test was performed. (ii) When there were more than two groups and one time point, a one-way analysis of variance (ANOVA) was performed. (iii) When there were more than two groups and multiple time points, a two-way ANOVA was performed. All analyses were performed using GraphPad (GraphPad Software, La Jolla, CA, USA; http://www.graphpad.com). For all comparisons, the level of significance was P 0.05.

Acknowledgments: We thank the staff at the Bioresources Unit in Trinity College Dublin for veterinary assistance and technical support. Funding: This publication has emanated from research supported by a research grant from the European Research Council (ERC) under grant no. 647004, the Irish Research Council (GOIPD/2016/324), and NIHs NIAMS grant R01AR063194. Author contributions: F.E.F. was responsible for technical design, development of bioinks, performing all animal surgeries, performing vessel perfusion, all CT scans, data interpretation, histological analysis, and drafting the paper. P.P. assisted with the rat surgeries and assisted with the vessel perfusions. L.H.A.v.D. assisted with CT analyses and CT scans. J.N. and D.C.B. assisted with all animal surgeries. J.-Y.S. and E.A. developed the RGD -irradiated alginate. D.J.K. conceived and helped design the experiments, oversaw the collection of results and data interpretation, and finalized the paper. Competing interests: Research undertaken in the laboratory of D.J.K. at Trinity College Dublin is part-funded by Johnson & Johnson. The authors declare no other competing interests. Data and materials availability: All data needed to evaluate the conclusions in the paper are present in the paper and/or the Supplementary Materials. Additional data related to this paper may be requested from the authors.

Read this article:
3D bioprinting spatiotemporally defined patterns of growth factors to tightly control tissue regeneration - Science Advances

Bone Marrow Stem Cells Comments Off on 3D bioprinting spatiotemporally defined patterns of growth factors to tightly control tissue regeneration – Science Advances | August 15th, 2020

Global Stem Cell Therapy Market is expected to reach an approximate CAGR of 10.3% during the forecast period. The use of stem cell for treating medical conditions is referred to as stem cell therapy. Stem cells are undifferentiated cells and differentiate into specialized cell types.

This ability of stem cells to differentiate into cells of interest is used to treat diseases like diabetes, heart disease, hematopoietic disorders (for example leukemia, thalassemia, and others), degenerative disorders (osteoarthritis, Alzheimers disease, Parkinsons disease, chronic renal failure, congestive cardiac failure,) and others.

Some of the key players are Osiris Therapeutics, Inc. (US), MEDIPOST Co., Ltd. (South Korea), Anterogen Co., Ltd. (South Korea), Pharmicell Co., Ltd. (South Korea), Holostem Terapie Avanzate S.r.l. (Italy), JCR Pharmaceuticals Co., Ltd. (Japan), NuVasive, Inc. (US), RTI Surgical, Inc. (US), and AlloSource (US), Thermo Fisher Scientific are some of the key players operating in the global stem cell therapy market.

Avail Sample copy For this Report at: https://www.marketresearchfuture.com/sample_request/6422

Global Stem Cell Therapy Market, by Technique,

Global Stem Cell Therapy Market, by Product Type

Global Stem Cell Therapy Market, by Application

Global Stem Cell Therapy Market, by End-User

Geographically, Americas is the largest in the market owing to the increasing prevalence of heart diseases and growing healthcare expenditure. According to the Centers for Disease Control and Prevention in November 2017, report every year 735,000 Americans have a heart problem. Such a high number of heart patients in the Americas drives the market growth in this region.

Brows Full Report at: https://www.marketresearchfuture.com/reports/stem-cell-therapy-market-6422

Europe (UK, Belgium, France, and Netherlands) is the second largest global stem cell therapy market during the forecast period. The increasing occurrence of stroke, cancer, and osteoarthritis drives the market in this region. According to Anthony Nolan organization 2017, annual review 1.4million people register for donating stem cell in 2017. Also, more than 2,200 searches for a lifesaving stem cell transplant were made in 2017 by UK people. Such a high demand for Stem cell transplantation in this region promotes the market.

Asia-Pacific was projected to be the fastest growing region for the global stem cell therapy market in 2017. The market is expected to witness growth owing to the rising prevalence of smoking in this region.

According to the American Cancer Society, Inc 2018, report China 48.9%, India 16.2%, Japan 11.2% accounts of cancer cases in this region. Such a high cancer rate in this region favors the stem cell therapy market in this region.

The Middle East and Africa accounts for the least share due to low per capita income and lack of availability of well-trained healthcare professionals. However, the rising oncology and technology both at the hospital level and in the community are expected to influence the market in a positive way.

Enquire Discount for this Report at: https://www.marketresearchfuture.com/check-discount/6422

Key factors responsible for the market growth are the rising awareness for therapeutic application of stem cells in disease management, rising research for stem cell therapy applications, development of advanced genetic analysis techniques, increasing public-private investments for stem cell research, growing research in identification of new stem cell lines, and new developments in stem cell banking infrastructure are driving the growth of the global stem cell therapy market. Stem cells are used in the treatment of Alzheimers by replacing the diseased cells with stem cells

About Market Research Future:

At Market Research Future (MRFR), we enable our customers to unravel the complexity of various industries through our Cooked Research Report (CRR), Half-Cooked Research Reports (HCRR), Raw Research Reports (3R), Continuous-Feed Research (CFR), and Market Research & Consulting Services.

Contact:

Market Research Future

+1 646 845 9312

Email:[emailprotected]

Continue reading here:
Stem Cell Therapy Market Application Growth, Technology, Trends and Key Players Developments on Regional Industry Size Till 2023 - eRealty Express

Cardiac Stem Cells Comments Off on Stem Cell Therapy Market Application Growth, Technology, Trends and Key Players Developments on Regional Industry Size Till 2023 – eRealty Express | August 15th, 2020

Mystified by the need for defibrillation to save a 10-year-old from drowning, Michael Ackerman, M.D., Ph.D., vowed to dig for answers. That pivotal case during a Mayo Clinic pediatric cardiology residency was the catalyst for Dr. Ackermans career in genetic sleuthing of inherited sudden cardiac death syndromes. With help from the Center for Regenerative Medicine Biotrust, Dr. Ackermans team reprograms cell lines to zero in on precise causes and possible treatments for genetic heart disorders that increase the risk of sudden cardiac death. His research and practice focus on inherited conditions like long QT syndrome (LQTS), catecholaminergic polymorphic ventricular tachycardia (CPVT) and Brugada syndrome (BrS) along with heart muscle diseases such as hypertrophic cardiomyopathy (HCM).

Working with the Center for Regenerative Medicine has opened up a whole new investigative arm to our lab. It is bench to bedside research. We take cells from a blood sample from my patients and then reprogram those cells to become cardiac cells. This research effort has been a powerful tool in gene discovery to prove beyond a shadow of a doubt when a monogenetic variant is indeed the cause of a sudden cardiac death syndrome, says Dr. Ackerman.

Reprogramming cells to identify disease-causing mutations

Reprogramming a patients cells is like a step back in time to when the cells were initially forming in the mothers womb. At that time, cells were dividing and could become any type of cell or tissue in the body. Reprogrammed cells, known as induced pluripotent stem cells, can be redirected to become new heart cells. Dr. Ackermans team uses these patient-specific cell lines to create a disease in a dish model and investigate whether genetic mutations are causing the patients genetic heart disease such as long QT syndrome.

Once we think weve found the root cause of disease, we then go to the patients cell line. We ask, does it show in the dish, in that patients re-engineered heart cells, a prolonged QT cellular phenotype? If it does, then we edit out and correct that variant of interest and at the cellular level test whether the abnormality disappears, says Dr. Ackerman.

Dr. Ackermans team then introduces that genetic variant into normal, healthy cells. If those cells produce a long QT phenotype, they have proof that exact genetic variant is the cause.

Using this disease in a dish model and other genetic sleuthing strategies, Dr. Ackermans team has discovered six of the 17 known genes that cause long QT syndrome. And, they have recently described two entirely new syndromes. One is triadin knockout syndrome, a heart arrhythmia that could lead to cardiac arrest in children during exercise. The second is an autosomal recessive genetic mechanism for calcium release channel deficiency syndrome, prevalent within Amish communities. That key discovery solved the mystery of why so many Amish children were dying suddenly during ordinary childhood play. The disease in a dish model is also useful for discovering new therapies. After creating the patients disease in a dish, Dr. Ackermans team tests potential new drug compounds to see if they could be effective.

We are developing a new gene therapy for the most common genetic subtype of long QT syndrome.With this model, the gene therapy vector is essentially curing the diseased long QT phenotype in the dish, says Dr. Ackerman.

Almost quit research

Dr. Ackerman began medical and graduate school at Mayo Clinic in 1988, where he worked in a research lab next to then fellow trainee, Andre Terzic, M.D., Ph.D., who now is director of Mayo Clinic Center for Regenerative Medicine. Initially not seeing the relevance to patient care, Dr. Ackerman finished his Ph.D. and left research vowing to never, ever return. True to his mentors predictions that youll be back, Mike, Dr. Ackerman felt the pull back to research to address unmet medical needs of his patients.He joined Mayo Clinics faculty in 2000 as one of the first genetic cardiologists with a goal of establishing a practice for patients at risk of sudden cardiac death from genetic heart diseases. Dr. Ackerman now directs the Mayo Clinic Windland Smith Rice Genetic Heart Rhythm Clinic and the Mayo Clinic Windland Smith Rice Sudden Death Genomics Laboratory.

Dr. Ackermans return to research has provided many answers for patients, with over 600 peer-reviewed publications that have occurred since that time 23 years ago when Dr. Ackerman and his team first solved that 10-year-old boys near fatal drowning. It was a mutation in the gene causing type 1 long QT syndrome.

Dr. Ackerman is one of the innovators the Center for Regenerative Medicine collaborates with as it seeks to be a global leader and trusted destination for regenerative care driven by research and education.

###

Tags: Brugada syndrome, Center for Regenerative Medicine Biotrust, hypertrophic cardiomyopathy, long Q T syndrome, Mayo Clinic Center for Regenerative Medicine, Michael Ackerman, People, Research, Stem cell research, sudden cardiac death

Read the rest here:
Using stem cells to find causes and treatments to prevent ...

Cardiac Stem Cells Comments Off on Using stem cells to find causes and treatments to prevent … | August 15th, 2020

"You start to feel like there's this temptation of fate," she said. "Once your allusion of permanence is shattered, you feel like anything could happen."

But it was exactly this that made her want to go through with it. After planning so many funerals, going to the hospital to give bone marrow that would help a young boy and his family seemed the right thing to do.

Losing time with her own relatives made her adamant about the ability to help give more time to someone else.

In June, she underwent physical tests and surgery to extract the bone marrow. She felt mostly OK like she had fallen on ice and "got out of laundry for a few days." She knows she can't speak for all donors, but for her, it was a fairly swift recovery.

She thought of the child's family. She remembered her four children at age 7.

"I remember how little they were," she said. "You just want to protect them."

She doesn't know anything more about the boy, and DMKS can't release more information because of privacy laws. His family can reach out to her, but Leone says she's not expecting any communication because she is sure they have plenty going on with him undergoing treatment.

But she isn't seeking gratitude. In fact, she feels she has been given a gift. The thought that perhaps she is able to help is a bright spot in a tough year.

Go here to see the original:
Chicago mom of 4 donates bone marrow to 7-year-old boy she doesn't know. 'You just want to protect them.' - Herald & Review

Bone Marrow Stem Cells Comments Off on Chicago mom of 4 donates bone marrow to 7-year-old boy she doesn’t know. ‘You just want to protect them.’ – Herald & Review | August 13th, 2020

New Jersey, United States,- Verified Market Researchhas recently published an extensive report on the Stem Cell Therapy Market to its ever-expanding research database. The report provides an in-depth analysis of the market size, growth, and share of the Stem Cell Therapy Market and the leading companies associated with it. The report also discusses technologies, product developments, key trends, market drivers and restraints, challenges, and opportunities. It provides an accurate forecast until 2027. The research report is examined and validated by industry professionals and experts.

The report also explores the impact of the COVID-19 pandemic on the segments of the Stem Cell Therapy market and its global scenario. The report analyzes the changing dynamics of the market owing to the pandemic and subsequent regulatory policies and social restrictions. The report also analyses the present and future impact of the pandemic and provides an insight into the post-COVID-19 scenario of the market.

Global Stem Cell Therapy Market was valued at USD 117.66 million in 2019 and is projected to reach USD 255.37 million by 2027, growing at a CAGR of 10.97% from 2020 to 2027.

The report further studies potential alliances such as mergers, acquisitions, joint ventures, product launches, collaborations, and partnerships of the key players and new entrants. The report also studies any development in products, R&D advancements, manufacturing updates, and product research undertaken by the companies.

Leading Key players of Stem Cell Therapy Market are:

Competitive Landscape of the Stem Cell Therapy Market:

The market for the Stem Cell Therapy industry is extremely competitive, with several major players and small scale industries. Adoption of advanced technology and development in production are expected to play a vital role in the growth of the industry. The report also covers their mergers and acquisitions, collaborations, joint ventures, partnerships, product launches, and agreements undertaken in order to gain a substantial market size and a global position.

1.Stem Cell Therapy Market, By Cell Source:

Adipose Tissue-Derived Mesenchymal Stem Cells Bone Marrow-Derived Mesenchymal Stem Cells Cord Blood/Embryonic Stem Cells Other Cell Sources

2.Stem Cell Therapy Market, By Therapeutic Application:

Musculoskeletal Disorders Wounds and Injuries Cardiovascular Diseases Surgeries Gastrointestinal Diseases Other Applications

3.Stem Cell Therapy Market, By Type:

Allogeneic Stem Cell Therapy Market, By Application Musculoskeletal Disorders Wounds and Injuries Surgeries Acute Graft-Versus-Host Disease (AGVHD) Other Applications Autologous Stem Cell Therapy Market, By Application Cardiovascular Diseases Wounds and Injuries Gastrointestinal Diseases Other Applications

Regional Analysis of Stem Cell Therapy Market:

A brief overview of the regional landscape:

From a geographical perspective, the Stem Cell Therapy Market is partitioned into

North Americao U.S.o Canadao MexicoEuropeo Germanyo UKo Franceo Rest of EuropeAsia Pacifico Chinao Japano Indiao Rest of Asia PacificRest of the World

Key coverage of the report:

Other important inclusions in Stem Cell Therapy Market:

About us:

Verified Market Research is a leading Global Research and Consulting firm servicing over 5000+ customers. Verified Market Research provides advanced analytical research solutions while offering information enriched research studies. We offer insight into strategic and growth analyses, Data necessary to achieve corporate goals, and critical revenue decisions.

Our 250 Analysts and SMEs offer a high level of expertise in data collection and governance use industrial techniques to collect and analyze data on more than 15,000 high impact and niche markets. Our analysts are trained to combine modern data collection techniques, superior research methodology, expertise, and years of collective experience to produce informative and accurate research.

Contact us:

Mr. Edwyne Fernandes

US: +1 (650)-781-4080UK: +44 (203)-411-9686APAC: +91 (902)-863-5784US Toll-Free: +1 (800)-7821768

Email: [emailprotected]

See the article here:
Stem Cell Therapy Market Size by Top Companies, Regions, Types and Application, End Users and Forecast to 2027 - Bulletin Line

Bone Marrow Stem Cells Comments Off on Stem Cell Therapy Market Size by Top Companies, Regions, Types and Application, End Users and Forecast to 2027 – Bulletin Line | August 13th, 2020

Unlike other CAR T-cell therapies, clinical success was not associated with significant complications from therapy, said Dr. Jonathan Serody. This means this treatment should be available to patients in a clinic setting and would not require patients to be hospitalized, which is critical in our current environment.

Results from the parallel phase 1 and phase 2 studies also demonstrated that the CAR T-cell therapy was safe and did not produce any serious or severe side effects.

Researchers from the UNC Lineberger Comprehensive Cancer Center and Baylor College of Medicine administered anti-CD30 CAR T cells to 41 patients with relapsed or refractory Hodgkin lymphoma. All patients underwent lymphodepletion with bendamustine alone, bendamustine and fludarabine, or cyclophosphamide and fludarabine prior to the anti-CD30 CAR T-cell therapy.

Measuring safety was the primary goal of the two parallel studies.

The overall response rate, or the percentage of partial or complete responses to therapy, among 37 evaluable patients was 62%. Thirty-four of the patients received fludarabine-based lymphodepletion 17 of which received it with bendamustine, and the other half received it with cyclophosphamide. Two of these patients were considered to be complete response at infusion and maintained the response, so they were not included in final analysis.

The overall response rate among the remaining patients was 72%, with 59% of patients achieving a complete response. After a median follow-up of 533 days, researchers identified the one-year progression free survival rate to be 36% and the one-year overall survival rate to be 94%.

This is particularly exciting because the majority of these patients had lymphomas that had not responded well to other powerful new therapies, said senior study author Dr. Barbara Savoldo, professor in the Department of Microbiology and Immunology at the UNC School of Medicine, in a press release.Patients within the study had received a median of seven previous lines of therapy that included checkpoint inhibitors and autologous or allogeneic stem cell therapies, therapies known to be powerful but also tend to come with a host of side effects.

However, treatment with the anti-CD30 CART cells demonstrated a favorable safety profile. Although 10 patients developed cytokine release syndrome, all cases were considered minor.

Patients who received fludarabine-containing lymphodepletion were the only participants in the study to have a response to the anti-CD30 CAR T-cell therapy.

Although CD30 CAR T (cells) showed modest activity in (Hodgkin lymphoma) when infused without lymphodepletion, robust clinical responses were achieved when these cells were infused in hosts lymphodepleted with fludarabine-containing regimens, the authors wrote.

The activity of this new therapy is quite remarkable and while we need to confirm these findings in a larger study, this treatment potentially offers a new approach for patients who currently have very limited options to treat their cancer, said Dr. Jonathan Serody, director of the bone marrow transplant and cellular therapy program at UNC Lineberger Comprehensive Cancer Center, in the release. Additionally, unlike other CAR T-cell therapies, clinical success was not associated with significant complications from therapy. This means this treatment should be available to patients in a clinic setting and would not require patients to be hospitalized, which is critical in our current environment.

Follow this link:
Novel CAR T-Cell Therapy Shows Promise in Advanced Hodgkin Lymphoma - Curetoday.com

Bone Marrow Stem Cells Comments Off on Novel CAR T-Cell Therapy Shows Promise in Advanced Hodgkin Lymphoma – Curetoday.com | August 13th, 2020

Jakafi may offer a survival benefit for patients with myelofibrosis and an increased number of circulating blasts, a recent study found.

While the presence of circulation blasts in the blood is considered an important factor in patient prognosis, the impact of bone marrow blasts on survival is not as well defined. To better understand the connection between the amount of blasts found in the blood and bone marrow together, all in regard to patient prognosis, researchers performed a retrospective analysis of 1,316 patients with myelofibrosis, a type of myeloproliferative neoplasm (MPN).

These patients (median age, 66 years), who all presented to the University of Texas MD Anderson Cancer Center in Houston, Texas, from July 1984 and 2018, had to have available circulation blasts in the blood and bone marrow percentages to be included in the analysis. Survival was noted as the time from the date of referral to the date of last follow-up or death, whichever came first. The median follow-up was 27 months.

Among the total, 700 (53%) had 0% circulation blasts in the blood and less than 5% had bone marrow blasts. Of the remaining patients who had 1% or greater circulation blasts in the blood, the range was as follows:

The researchers also found that higher percentages of circulating blasts in the blood had a negative correlation with hemoglobin and platelets, but a positive correlation with white blood cells, age and the presence of symptoms, among other factors.

Out of the total group, 523 patients (44%) received the JAK1/JAK2 inhibitor Jakafi. The authors noted that patients who received this treatment and also had 10% or less blasts, regardless of whether they were in the blood or bone marrow, saw a superior overall survival rate compared to those with similar disease features who did not receive Jakafi.

The studys authors went on to conclude that patients who have circulating blasts in the blood of 4% or more have an unfavorable prognosis; however, Jakafi offers a significant survival benefit to patients with circulating blasts in the blood of 10% or less, making a combination approach to treatment vital in improving the outcomes of patients with myelofibrosis.

Go here to see the original:
Jakafi May Offer Survival Benefit in Subset of Patients with Myelofibrosis - Curetoday.com

Bone Marrow Stem Cells Comments Off on Jakafi May Offer Survival Benefit in Subset of Patients with Myelofibrosis – Curetoday.com | August 13th, 2020

Poverty, Government apathy and Covid-19 induced-lockdown restricting travel proved fatal for little Kishan, a 11-year-old boy suffering from Aplastic anemia, a life-threatening blood disorder condition in which the bone marrow and stem cells do not produce enough blood cells

Facing severe financial constraints and waiting timely medical aid, first at Safdarjung Hospital and then AIIMS, both Government hospitals in Delhi, Kishans life was cut short in March this year amid Covid-19 pandemic.

However, Kishans is not a lone case. Dr Nita Radhakrishnan, paediatric haemato-oncologist at Super Speciality Paediatric Hospital, Noida, Uttar Pradesh says that as the deadly Coronavirus captured the attention of the nation in the most unprecedented manner, the non-Covid patients particularly those with the Aplastic anemia have suffered the most in the crisis.

She gave instances of her two teenage patients who succumbed to blood disorder in the Covid catastrophe. Manish (name change), a 17-year-old was suffering with on-and-off fever, gum bleeding, and melena for three months, he came to us in December last year just when Coronavirus had started spreading its tentacles from China to other parts of the world.

The boy was diagnosed with severe Aplastic anemia and was recommended requisite treatment like regular hospital visit for red cell transfusion before he could be given bone marrow transplant (BMT), a life saving treatment.

However, while the family was not able to visit our hospital in Noida due to the covid-lockdown, no blood products were available at the hospital near to the patients locality. In want of blood, Manish could not survive more days.

13-year-old Suresh (name change) too faced similar fate. While Government funds could not be sanctioned for his BMT in time the boy could not visit the Noida hospital for further follow-up due to travel restrictions. Two weeks later, Suresh died due to hemorrhage at his native place, lamented the doctor.

These are just two reported cases from the NCR hospital located near the countrys capital. Several have gone unreported. The Government has no policy nor any long-term plan for such patients.

The prognosis of severe aplastic anemia in our country is dismal. The incidence of 46 per million population of childhood aplastic anemia in India and other Asian countries is higher than what is observed in the West, explains Dr Radhakrishnan. The scenario is gloomy for the patients afflicted with the disease as they need blood transfusion almost every 20 days.

A significant proportion of patients of aplastic anemia (around 30 per cent) die before any definitive treatment is initiated. A study by AIIMS based on a recent series of patients follow-up showed that out of 1501 patients diagnosed over last seven years, only 303 ie 20 per cent received the definitive treatment modalities through either BMT or IST with ATG and cyclosporine, says Dr Radhakrishnan in her case report Aplastic anemia: Non-COVID casualties in the Covid-19 era, published in the latest edition of Indian Journal of Palliative Care.

The doctors have sought urgent intervention. Dr Radhakrishnan says that as we await the peak of Covid-19 in our country and possibly secondary and tertiary waves thereafter, patients with aplastic anemia who are the sickest among all hematological illnesses would benefit greatly from urgent intervention from the Government to ensure timely treatment.

Those suffering with Aplastic anemia, there is mostly delay in diagnosis, delay in initiation of treatment due to monetary constraints, non-inclusion of the disease under government schemes such as Ayushman Bharat and NHM and delay in sanction of money from other Government schemes such as Rashtriya Arogya Nidhi, Chief Minister and Prime Ministers relief fund often due to lack of proper documents, she added.

Delay means, risk of contracting fungal infections and increase in drug-resistant bacterial infections increase which further hamper the treatment, point out Dr Ravi Shankar and Dr Savitri Singh in the study.

Though the Union Health Ministry, after few days of lockdown period, issued directions for continuing treatment for essential health services including reproductive and maternal health services, newborn care, severe malnutrition, and NCDs including cancer care, palliative care, dialysis, and care of disabled, unfortunately those with Aplastic anemia got ignored.

This despite of the fact that these patients are at the highest risk of death following a break in the treatment of few weeks, notes Dr Radhakrishnan.

Because of the closure of offices and absence of staff, during the lockdown period, there was delay in sanction of usual grants due to the lockdown of offices and inability in generating documents such as income certificate from the tehsils.

For instance, Suresh and Manish, both our patients received the Government grant after around 34 months of applying for the same. But both had died before they could reach the hospital for treatment, lamented the hematologist.

View post:
Covid-19 Impact: Patients with aplastic anemia at receiving end - Daily Pioneer

Bone Marrow Stem Cells Comments Off on Covid-19 Impact: Patients with aplastic anemia at receiving end – Daily Pioneer | August 13th, 2020

INTRODUCTION

The ability to regenerate complex body parts varies considerably in the animal kingdom. While planarian and hydra are able to regenerate their entire bodies, many avian and mammalian species mostly stop at the wound healing stage without a reparative regeneration process (1). This disparity may result from complexity differences among organisms by nature, yet it leaves us the hope that we may learn from highly regenerative species to improve our own regenerative potential.

Zebrafish is known for its ability to regenerate multiple complex body structures (2). Among regenerable tissues, the caudal fin serves as a great model due to its faithful and rapid regeneration, ease of manipulation, and relatively low complexity. A key step in regeneration is the formation of the blastema, a layer of proliferative and undifferentiated cells that accumulates between the wound site and the wound epidermis following initial wound closure. This step occurs in response to appendage loss and is one of the key features that separates regenerative systems from nonregenerative systems. At later stages of regeneration, the blastema further proliferates and differentiates to regenerate the missing complex structures.

However, the molecular signatures of blastemal cell state transitions during regeneration in zebrafish remain elusive. The state of a cell can be represented by its collective gene expression profile, which has only been measured in bulk for all genes or in specific lineages of cells for a subset of genes during caudal fin regeneration. Prior work has shown that both proliferation of progenitors and dedifferentiation of adult lineage cells contribute to the blastema (38). Progenitors respond to injury cue and proliferate as in normal development. Cells derived from mature adult lineages, however, lose their lineage-specific markers while obtaining progenitor-like markers when they proliferate. Neither type of cell gains multipotency, but rather, they proliferate and regenerate with lineage restrictions. The limited resolution and throughput of these approaches have prevented a more systematic understanding of blastema cells. The advent of single-cell transcriptomic technologies promises to reveal signals masked at the bulk tissue level (9), granting us an opportunity to define and monitor cellular state transition in regenerating fin at an unprecedented resolution.

In this study, we generated single-cell transcriptomic maps of regenerating fin tissue. These maps allowed us to separate the contribution from different cell types and track the transcriptomic dynamics in cell state transitions during regeneration. By comparing with the profiles obtained from uninjured fin tissue, we identified cell types involved in regeneration. We demonstrated the activation of cell cyclerelated programs shared across cell types as well as cell typespecific programs. Furthermore, we defined the heterogeneity in both epithelial and blastemal populations and their functional relations to the regeneration process.

To better understand cell type involvement in fin regeneration, we characterized single-cell transcriptional landscapes for both preinjury and regenerating caudal fin tissues using the 10x Genomics platform (see Materials and Methods and table S1) (9). We sampled regenerating fins from 1, 2, and 4 days post-amputation (dpa) time points to interrogate the stages of blastema formation, outgrowth, and maintenance (Fig. 1A). Fin samples were collected from multiple fish to control for individual variation while at the same position along the proximal-distal axis to avoid positional effects. To establish the transcriptional ground states for each cell type in the fin tissue, we first focused on cells collected from the preinjury time point. Via an unsupervised clustering of 4134 cells, we identified epithelial cells (epcam and cdh1), hematopoietic cells (mpeg1.1 and cxcr3.2), and mesenchymal cells (msx1b and twist1a) (fig. S1, A and B) (1014). Epithelial cells are from three transcriptionally distinct subgroups, representing the superficial (krt4), intermediate (tp63), and basal layers (tp63 and krtt1c19e) of the epithelium (fig. S1, A and B) (15, 16).

(A) General experimental design. Zebrafish caudal fin tissues at preinjury and 1/2/4 dpa stages were collected. (B) Clustering assignments for caudal fin cells collected from each stage. Uniform Manifold Approximation and Projection (UMAP) axes were calculated from the integrated cells dataset as in (C). (C) Clustering assignments for caudal fin cells collected from both preinjury and regenerating stages. Cells were plotted on UMAP axes. Color coding is the same as in (E). (D) Percentage distribution of the major cell types captured in caudal fin, grouped by their stage of collection. Color coding is the same as in (E). (E) Differential expressions of the key marker genes by the identified major cell types. Color gradient: normalized relative expression level. Dot size: percentage of cells in the cluster that express the specified gene.

To determine whether the same cell types existed in the regenerating stages, we performed analysis using two different approaches: (i) Cells from each stage were clustered independently, and (ii) cells from both uninjured fins and injured fins were integrated through the anchoring approach (see Materials and Methods; Fig. 1, B, C, and E; and table S2) (17). For both approaches, we regressed out cell cycle effects before principal components analysis (PCA). Agreement between cluster assignments was measured using Hubert and Arabies adjusted Rand index (ARI). An average ARI of 0.86 (preinjury, 0.86; 1 dpa, 0.85; 2 dpa, 0.90; and 4 dpa, 0.83) indicated that clustering results generated using the two approaches were highly consistent. Cell types identified in the preinjury cells presented consistently across all regenerating stages, suggesting that regenerating fins contain the same cell types as the preinjury fins.

New regenerates are built up by the proliferation and migration of cells located at a number of fin segments away from the amputation plane (2). In response to injury cues, these cells gained the ability to detach from local tissue, enter cell cycle, and migrate toward the wound site while undergoing transcriptional reprogramming. We computationally separated S phase, G2-M phase, and G1-phase cells based on the expression level of cell cyclerelated genes and performed clustering analysis using only S phase cells (see Materials and Methods and fig. S2A). In this cycling cell population, we identified epithelial, mesenchymal, and hematopoietic cell groups as before (Fig. 2, A to C, and table S3). Our data support a model in which cells likely keep their original identities during proliferation.

(A) Cell type clustering of S phase cells plotted onto UMAP axes calculated by S phase cell only. Cells are colored by the general cell types merged from major cells types in Fig. 1B. (B) Stage distribution of S phase cells. Cells were plotted on the same UMAP axes as in (A) and colored by stage when the cells were collected. (C) Relative expression levels of the top 30 differentially expressed genes from each cluster of only S phase cells. (D) Venn diagrams of numbers of genes shared between the cell cycleactivated genetic programs. Left, included all genes; right, included only cell cyclerelated genes (see Materials and Methods).

Next, we asked whether different regenerating cell types exhibited similar or distinct cell cycle regulations. To this end, we identified genes up-regulated in S phase cells compared to G1 phase cells in each cell type, respectively (logFC, >0.25; minimum percentage, >10%). Of the 1098 differentially expressed genes, 161 were shared across all three groups of comparisons (Fig. 2D and table S4). Of these shared genes, at least 54 genes were related to cell cycle regulation, underscoring a shared program governing cell cycle reentry (criteria described in Materials and Methods). In contrast, hundreds of genes differentially highly expressed in S phase exhibited cell typespecific pattern, of which dozens were related to cell cycle (Fig. 2D). We next evaluated the degree of conservation of these enriched genes by asking what fraction did not have human orthologs that had been curated in the Metascape database (18). Twenty-five percent of genes in the epithelial cellspecific group had no human ortholog, whereas all shared groups had at most 15% genes without a human ortholog, suggesting that enriched genes shared by cell types were more evolutionarily conserved (fig. S2C).

Some cell typespecific S-G1 enriched genes were also expressed in a cell typespecific manner regardless of their cell cycle phases: For example, psmb8a and psmb9a shared similar epithelial-hematopoietic enrichments (fig. S2D). The human homologs of these genes (PSMB8 and PSMB9) encode 5i and 1i subunits of the immunoproteasome (19). Together with 2i and PA28 subunits of the proteasome, they turn the proteasome into immunoproteasome and take part in immune response (20). Immunoproteasome digests peptides more efficiently, promoting antigen presentation by a major histocompatibility complex (MHC) class I molecule. Although they did not pass the differential expression criteria in the S-G1 comparison, zebrafish psmb10, psme1, and psme2 shared a differential expression signature similar to that of psmb8a and psmb9a, suggesting that zebrafish might use the same group of subunits for the assembly of immunoproteasomes that might help increase immune responses during regeneration, especially in epithelial and hematopoietic cells (fig. S2, D and E). In addition, we found three genes that shared the same expression signature with the immunoproteasome subunits (psmb13a, psmb12, and psma6l) (fig. S2E) without known human or mouse homologs, suggesting that they might form zebrafish-specific proteasomes with functional relevance to regeneration (19).

Consistent with current knowledge, we observed three transcriptionally distinct subgroups in the preinjury epcam+ epithelial cells, representing the superficial, intermediate, and basal layers of the adult zebrafish epithelium (Fig. 3A and fig. S1B) (15, 16). By integrating cells from all stages during regeneration, we found clusters of cells that corresponded to all three layers of the epithelium after injury (Fig. 1, B and C). In addition, we captured a rare agr2+ population (referred to as mucosal-like epithelium herein) that was too small to be clustered by itself in the preinjury stage (Fig. 1E). These cells shared general epithelial features with the other epithelial layers but exhibited higher expression of a unique set of 200 genes. We examined the expression distribution of the orthologs of these genes in human tissues (The Human Protein Atlas, http://proteinatlas.org/) (21). Among the top 30 genes with human orthologs, 11 showed enriched expressions in proximal digestive or gastrointestinal tract and another 11 in bone marrow of blood lineages, suggesting that this population is analogous to cells in the mucosa in mammalian systems (table S2). In zebrafish, agr2 is required for the differentiation of the mucosal-producing goblet cells in the intestinal epithelium (22). To confirm the cell typespecific expression pattern of this gene in the fin tissue, we performed in situ hybridization on agr2 in both uninjured and regenerating fin tissues (see Materials and Methods). agr2 transcripts are scattered within the epithelium regardless of the sample collection stage and reflect a round morphology of the cell expressing it (fig. S3, A, C, E, and G to I). A proportion of agr2+ cells overlap with positive dark blue staining of Alcian blue in serial sections, suggesting that these cells are mucous cells that are known to exist in the caudal fin epithelium (fig. S3, B, D, and F) (23).

(A) Diagram of the stratified adult zebrafish epithelium. (B) Differential expressions of claudin family and keratin family genes in epithelial subgroups shown as a dot plot. Known epithelial markers krt4, fn1b, tp63, and krtt1c19e were included for comparison. Cells were first grouped by major cell types and then separated into preinjury and regenerating stages. Darkness of dot color: relative expression level. Dot size: percentage of cells in the cluster that express the specified gene. (C) In situ hybridization targeting krt1-19d, cldna, cldn1, and krt4 of 4-dpa fin tissues. Brown dots indicate positive RNA signals from target genes, while pale blue blocks represent hematoxylin-stained cell nuclei. Zoomed-in views are presented. Original images can be found in fig. S4. All epithelial layers are above the black dotted lines. (D) Clustering assignment of epithelial cells plotted on UMAP axes calculated with only epithelial cells. Cells are colored by their epithelial layer identity as in (A). (E) The same UMAP visualization as in (D), with cells colored by stage of collection. Arrows connect the groups of comparison, with a direction from preinjury stage to regenerating stages (1, 2, and 4 dpa). Numbers next to the green triangle: number of genes up-regulated in regenerating stage. Numbers next to the red triangle: number of genes down-regulated in regenerating stage. (F) Clustered GO enrichment for genes up-regulated in regenerating basal, intermediate, and superficial epithelial cells comparing to their preinjury counterparts. GTPase, guanosine triphosphatase; ER, endoplasmic reticulum; PKN, protein kinases N; snRNP, small nuclear ribonucleoprotein.

Although the same three-layer classification of epithelial cells could be defined when cells from regenerating stages were integrated with the preinjury cells, the expression of the commonly used layer-specific marker genes changed dramatically during regeneration: Superficial epithelial marker krt4 expanded into basal and intermediate layers of the epithelium, the intermediate layer marker fn1b was also highly expressed in the basal layer, and the basal epithelial marker krtt1c19e was barely detectable in the postinjury cell populations (Fig. 3B) (15, 16). To better understand the molecular features of the epithelial populations, we identified genes significantly more highly expressed in epithelial cells than in hematopoietic and mesenchymal cells and found that cell-cell junction genes ranked high in the list. Among these, genes from the claudin and keratin families were detected at a ratio 20-fold higher than that in randomly selected detectable genes (2 test, P value of <0.0001). We focused on expression patterns of all claudin and keratin genes in zebrafish and found that cldne, cldnf, krt1-19d, and krt17 labeled the superficial cluster; cldnh labeled the mucosal-like cluster; cldna, krt93, and krt94 labeled the intermediate cluster; and cldn1 and cldni labeled the basal cluster (Fig. 3B). Claudin genes are expressed in a tissue-specific manner in zebrafish and are generally considered to be the proteins responsible for regulating the paracellular permeability in the vertebrate epithelium (24). Their differential expression signature in both uninjured and regenerating tissues suggests that they might play important roles in maintaining the permeability in each epithelial population. On the other hand, the expression of keratin genes displayed less restriction across the three layers relative to claudin genes but stronger dependence on regenerating states (Fig. 3B). The differential expression signature suggests that they might perform epithelial subtyperelated function in regeneration. To verify their expression pattern, we performed RNA in situ hybridization targeting the known marker krt4 and new candidates, including krt1-19d, cldna, and cldn1 (Fig. 3C) as well as cldne, krt94, and cldni (fig. S4, A to H). Comparing with the known marker krt4, these genes exhibited more restricted expression patterns in epithelial layers, better representing the molecular signatures of different epithelial populations in the fin tissue regardless of regeneration status (Fig. 3, B and C).

The three epithelial layers were present across the regeneration stages albeit with varying proportions (Fig. 1D). The proportion of basal epithelial cells peaked at 2 dpa, reaching up to 42%, whereas the superficial layer epithelial cells decreased from 27 to 6% at 2 dpa (the coefficient of variations of cell proportions between biological replicates is below 15%). The observed compositional change of the two epithelial populations is consistent with a previous finding that the initial migration of superficial layer cells to the new regenerates is followed by replenishment by basal epithelial cells (25). This basal replenishment was also reflected in the two-dimensional Uniform Manifold Approximation and Projection (UMAP) calculation from only epithelial cells, in which preinjury cells were separated by their respective layers, whereas regenerating cells were closer in the projection space (Fig. 3, D and E). Superficial layer cells from before and after injury stages were in juxtaposition to each other, consistent with our knowledge that this layer of epithelial cells directly migrates to and covers the wound site (25). On the other hand, basal layer cells from before and after injury stages were more distantly separated, suggesting more dramatic changes between resting and regenerating basal epithelial cells.

To understand the mechanisms of epithelium regeneration, we compared the transcriptome between preinjury and regenerating cells for the three epithelial layers. Basal layer cells up-regulated 1271 genes and down-regulated 198 genes during regeneration; both were the highest numbers across all comparisons (numbers of differentially expressed genes were from Wilcoxon rank sum test, adjusted P value of < 0.01; Fig. 3E). We performed gene ontology (GO) enrichment analysis on genes up-regulated in the regenerating stage by layer and found both common and layer-specific programs associated with regeneration (18). All three layers were enriched for oxidative phosphorylation (dre00190), proteasome (dre03050), and cell redox homeostasis (GO:0045454). While basal and intermediate layer cells could be regulated by Rho guanosine triphosphatasemediated Wnt signaling for extracellular matrix organization and actin filament depolymerization, respectively (R-DRE-195258, R-DRE-5625740, R-DRE-195721, GO:0030198, and GO:0030042), superficial layer cells showed enrichment mainly for general transcriptional and translational regulations (Fig. 3F). When comparing the expression profiles between regenerating superficial epithelial and basal epithelial, we saw enrichment for antigen presentation and apoptosis features in the superficial layer (table S5). In addition, the superficial layer contained the lowest proportion of cells in S phase or G2-M phase, further supporting that superficial layer epithelium was most likely maintained by migration and proliferation from other layers (fig. S2B).

Subcluster identification within regenerating basal epithelial cells revealed two subgroups that represented different functionalities during regeneration, one labeled by distally distributed fgf24, while the other by proximally distributed lef1 (fig. S5, A to C) (26, 27). We compared expression profiles between group I (distal) and group II (proximal) cells and found that their suggested functionalities were consistent with their expected roles in regeneration: The distal subgroup (or distal wound epidermis) up-regulated genes associated with extracellular matrix degradation, and the proximal subgroup (or proximal wound epidermis) up-regulated genes associated with organization of extracellular matrix, skeletal system development, and negative regulation of locomotion (fig. S5, D and E). In addition, the increase of proximal cell proportion was accompanied by the decrease of distal cell proportion, suggesting that basal layer epithelium become gradually active in promoting blastema proliferation and differentiation during the initial regeneration process (fig. S5C). To confirm the distribution of these cells, we performed RNA in situ hybridization targeting two candidate genes, stmn1b and sema3b, one from each cluster. The expression of stmn1b was first observed at the basal layer of the wound epidermis at 1 dpa but diminished as regeneration proceeded (fig. S4, I to K). On the contrary, sema3b showed expression at later stages and was enriched in the relatively proximal portion of the basal layer epithelium (fig. S4, L to N). The expression dynamics of these two genes matched the predicted proportion changes of the two clusters (fig. S5C). While sema3b was more restricted to the basal layer, stmn1b showed low expression levels in the intermediate layer as well, potentially suggesting that this subpopulation could be labeling cells transitioning from the basal layer to the other layers of epithelium.

We next performed subcluster analysis within the hematopoietic cluster and found four subpopulations (Fig. 4, A to C and table S6). The first three populations were enriched for the macrophage marker mpeg1.1, with the cluster H1 being M1-like (lgals2+ and lcp1+) and the cluster H3 M2-like (ctsc+ and lgmn+) (Fig. 4D) (12). We speculated that the cluster H2 represented a transition state between M1-like and M2-like or a state before the macrophages differentiate toward M1-like or M2-like. From 1 to 4 dpa, the proportion of M1-like macrophages remained at a constant level, while that of M2-like macrophages expanded (Fig. 4B), potentially suggesting a shift in the function of macrophages in the new regenerates from pro-inflammatory toward anti-inflammatory as regeneration proceeded. Macrophages are important for proper blastema proliferation (28). The change in the proportions of M1/M2-like macrophage in our data matched with that observed in the larvae fin, suggesting that the adults followed a similar rule for immune cell recruitment after injury.

(A) Subcluster assignments of the hematopoietic cells. Cells were plotted on UMAP axes. The same color code is used for (B) to (D). (B) Proportion of subgroups of hematopoietic cells. (C) Expression enrichment of the top 30 differentially expressed genes in the four subclusters within hematopoietic cluster shown as a heatmap. (D) Expression distribution of genes associated with macrophage activation grouped by subclusters. Expression levels were log normalized by Seurat. y axis: cluster identity. z axis: cell density. (E) Expressions of pigment cell markers gch2 and mlpha in the hematopoietic population.

The cluster H4 enriched for genes including mlpha and gch2, both well-characterized markers for the chromatophore lineages in zebrafish (Fig. 4E) (29). Chromatophores are derived from neural crest lineage, yet here, they clustered with macrophages that were from hematopoietic lineage. One possibility is that this clustering result could be driven by features related to antigen presentation via MHC class II, a feature of pigment cells based on studies using human melanocytes (30). The proportion of this cluster decreased as regeneration started, agreeing with the known pattern of fin stripe recovery after amputation (Fig. 4B) (31).

To understand the component and function of the cells in the mesenchymal cell cluster before and during fin regeneration, we focused on genes enriched in this cluster and found previously identified blastema marker genes that are required for fin regeneration, including the muscle segment homeobox family members msx1b and msx3 and the insulin-like growth factor signaling ligand igf2b (logFC, >0.25; minimum percentage, >25%; and adjusted P value of <1 105, as listed in table S1) (2, 13). The mesenchymal cluster expressed these genes nearly exclusively, confirming their blastema identity in regenerating stages (fig. S6A). In addition, we found key genes involved in zebrafish bone development and regeneration: twist1a, the transcription factor that controls the skeletal development by regulating the expression of runx2 (14); cx43, the gap junction protein required for building the fin ray up to the right length; and hapln1a and serpinh1b, two genes downstream of cx43 (32, 33). By performing conserved marker analysis using Seurat, we found that msx1b and twist1a were also among the markers conserved across all stages, underscoring shared features that existed between regenerating and preinjury mesenchymal cells (maximum P values across stages: 4.72 1010 and 2.84 109 for msx1b and twist1a, respectively). This theme of building and supporting bone tissues in mesenchymal cells was not only reflected by a handful of genes: GO analysis of all the detected up-regulated genes in this cluster revealed significant enrichment of genes associated with GO terms, including fin regeneration (GO:0031101) and skeletal system development (GO:0001501) (fig. S6B). When more stringent criteria for differential expression were used, genes were also significantly enriched for GO terms, including skeletal system morphogenesis (GO:0048705) and extracellular matrix organization (GO:0030198) (fig. S6C).

Previous work has shown that blastema comprises bone cells and non-bone cells but has not defined the cell types and the regeneration process of each type (23, 34, 35). To better understand the regeneration process by cell type, we performed clustering analysis within the mesenchymal cluster and identified nine distinct subgroups (Fig. 5A and fig. S6D). Of the two preinjury subgroups, M-2 represented the mature bone lineage, which was enriched for expressions of bglap, mgp, and sost (fig. S6E) (36, 37). Comparing to M-2, cluster M-1 presented low expression levels of bglap, mgp, and sost and high expression levels of a group of other genes, including fhl1a, fhl2a, and tagln (fig. S6E). Mammalian orthologs of these genes are required for chondrogenesis and osteogenesis, leading us to speculate that cluster M-1 could represent the supporting non-bone cell lineage in the preinjury state (38, 39).

(A) Subclustering assignments of mesenchymal cells shown on UMAP axes. Cells are colored by their cluster assignments and connected by Slingshot-reconstructed trajectories. Lineage 1: 1-2-3-4; lineage 2: 1-2-3-5-6; lineage 3: 1-2-3-5-7-8; lineage 4: 1-2-3-5-9. (B) By-lineage highlighting of mesenchymal cells. Cells with colors other than gray represent the cells included in each corresponding lineage in (A). (C) Expression distribution of genes labeling cell lineages and cell states in mesenchymal cells. Gene feature plots were connected by estimated lineages using the same lineage color code as in (A). (D to G) In situ hybridization targeting the tnfaip6 gene in (D) preinjury, (E) 1-dpa, and [(F) and (G)] 4-dpa fin tissues. Brown dots indicate positive RNA signals from target genes, while pale blue blocks represent hematoxylin-stained cell nuclei. A zoomed-in view for the region inside the focused rectangle is provided within (D). (G) Zoomed-in view for the region highlighted by a rectangle in (F). Dotted lines indicate the amputation plane. All scale bars, 100 m.

The remaining seven populations came from regenerates. Pseudotime analysis via Slingshot (40) suggested that these subgroups formed four trajectories, all initiated from the tnfaip6+ cluster (M-3), which was composed mainly of 1-dpa cells (Fig. 5, B and C, and fig. S6D). tnfaip6 was ranked top by an adjusted P value in the differentially expressed genes labeling the regeneration initiation cluster and was also expressed exclusively in the mesenchymal cluster (Fig. 5C and fig. S6A). The mammalian ortholog of this gene is required for proliferation and proper differentiation of mesenchymal stem cells (MSCs) and balances the mineralization via osteogenesis inhibitions (41). The expression of tnfaip6 in the postinjury zebrafish fin suggested that it could also be required in the early stages of regeneration for promoting mesenchymal proliferation. To confirm the expression pattern of tnfaip6, we performed RNA in situ hybridization for uninjured and regenerating fin tissues targeting this gene (Fig. 5, D and E). In the uninjured fin, tnfaip6 was expressed in a segmental pattern, presumably enriching at joints between bone segments. At 1 dpa, tnfaip6 was expressed not only near the bony rays but also in the cavity, showing a general activation in the mesenchymal population. As regeneration proceeded from 1 to 4 dpa, mesenchymal cells divided into cdh11+ (M-4) and tph1b+ (M-5) branches, with the latter further divided into mmp13a+ (M-6), tagln+ (M-7), and vcanb+ (M-9) branches (Fig. 5C and fig. S6D). The mmp13+ (M-6) cluster maintained a high-level tnfaip6 expression, whereas all other branches had a lower but detectable tnfaip6 expression. This was consistent with the observation we made from in situ hybridization at 4 dpa targeting tnfaip6: the broad expression in the mesenchymal population and segmental enrichments similar to that in the uninjured fin (Fig. 5, F and G).

The four trajectories initiated from the tnfaip6+ cluster revealed four putative lineages representing bone and non-bone cells in the blastema. cdh11+ lineage 1 specifically expressed runx2 and osterix/sp7, which are the key transcription factors regulating osteogenesis (fig. S6E) (42). Mammalian ortholog of cdh11 could induce Sp7-dependent bone and cartilage formation in vivo, suggesting that the cdh11+ branch in the blastema represented the regenerating osteoblasts (43). Genes highly expressed at the end of this lineage (M-4) compared to the initiation point (M-3) were associated with bone mineralization and skeletal system development, further supporting their bone cell identity (table S7).

Mesenchymal cells outside the osteoblast branch shared enrichment for tph1b and aldh1a2 expressions at 2 dpa, followed by and1 expression at 4 dpa (Fig. 5C and fig. S6F). These three genes had been suggested to label joint fibroblasts, fibroblast-derived blastema cells, and actinotrichia-forming cells in the blastema, respectively (34, 35, 44). However, their expression signatures implied that instead of labeling separate populations in the blastema, they might be labeling different states of the same non-osteoblastic cells at the early stage of fin regeneration.

Upon 4 dpa, these non-osteoblastic cells diverged into three groups (Fig. 5C and fig. S6D). To understand this separation, we performed differential expression analysis for each branch between cells at the end of the lineage tree (lineage 1, M-4; lineage 2, M-6; lineage 3, M-7 and M-8; and lineage 4, M-9) and cells in the initiation cluster (M-3). Genes highly expressed at the lineage end points were included for GO analysis for functional predictions (logFC, >0.25; minimum percentage of >25%; and adjusted P value of <0.01). These three lineages were also associated with skeletal system development or extracellular matrix organizations as were the bone cell lineage; however, the association was driven by a nearly completely different set of genes (table S7). Unlike the osteoblast lineage, none of these three non-bone cell lineages showed enrichment for bone mineralization, suggesting that these cells might indirectly contribute to bone formation. In lineage 2, top differentially expressed genes mmp13a and ogn both have mammalian orthologs that are associated with bone formation (Fig. 5C and fig. S6F) (45, 46). In addition, this lineage presented up-regulation of DLX family genes, especially dlx5a, suggesting the reactivation of fin outgrowthrelated developmental programs during regeneration (fig. S6F and table S7) (47). Lineages 3 and 4 both enriched for estrogen response and expressed the retinoic acid (RA) synthesis gene aldh1a2. However, only lineage 3 displayed up-regulation of the RA-degrading enzyme cyp26b1 (fig. S6F and table S7). The cyp26b1high-aldh1a2low pattern helped to reduce RA levels in the blastema, promoting redifferentiation of the osteoblasts (44). The differentiation-promoting signature was also reflected in the enrichment of genes, including col6a1 and tagln, whose mammalian orthologs are essential for bone formation (fig. S6F and table S7) (39, 48). These genes were also enriched in the preinjury non-bone cell population, suggesting a connection between this subset of the non-bone cells and their preinjury counterparts (Fig. 5C and fig. S6F). Top up-regulated genes in lineage 4, on the other hand, were main contributors of the extracellular matrix, including and1/2, loxa, and vcanb (35, 49, 50). Enriched expression of these genes suggested that this lineage could be responsible for creating and organizing the fibrous environment. Together, the various non-osteoblastic cells could potentially work collaboratively with the osteoblasts in creating the environment for bone tissue regeneration.

Genes that had been suggested to label progenitors contributing to fin regeneration (mmp9 and cxcl12a) and several orthologs of known mammalian MSC markers (lrrc15, prrx1a/b, and pdgfra) (6, 7, 51, 52) were expressed almost exclusively in the mesenchymal cluster (fig. S6A). Consistent with the observations made in the lineage-tracing study, the mmp9 expression was associated with the regenerating bone cell lineage (lineage 1; Fig. 5B and fig. S6E) (7). However, mmp9 was detected only in a small portion of the mesenchymal cells and was highly expressed in the basal epithelium cells at similar proportions. On the other hand, we observed coenrichment of cxcl12a (previously known as sdf-1) and orthologs of the known mammalian MSC markers in the preinjury population (fig. S6E). cxcl12a-expressing cells in zebrafish were found to carry osteogenic, adipogenic, and chondrogenic characteristics in vitro like MSCs would do and contributed to the mesenchyme of the newly developing bony rays during fin regeneration (6, 53). The coenrichment pattern suggested that some of the preinjury cxcl12a-expressing cells could be MSCs in the fin tissue, which contribute to fin regeneration.

Zebrafish caudal fin is a unique regeneration system to model the injury response and regeneration of vertebrate appendages despite being a simple structure without muscular and adipose tissues. Major components of the regenerating caudal fin are epithelial cells covering the wound site and blastemal cells producing the connective tissue and bone matrices. Early studies established that actively proliferating blastema is the key to regeneration. Formed by cell migration and proliferation, this layer of cells continues in outgrowth and differentiation, rebuilding the complex body structure. Despite efforts in understanding its importance, basic questions regarding the formation of blastema remained: (i) Which type of cells contributes to the blastema and (ii) how do they shape the regeneration process?

Using single-cell transcriptomes, we defined cell types in both preinjury and postinjury fin tissues. Although regenerating cells were drastically different from their preinjury counterparts, both stage-specific and integrated clustering analysis revealed the same major cell type compositions in the fin tissues regardless of their time of collection. Common cell types detected include epithelial cells from all three layers, hematopoietic cells, and mesenchymal cells. Our data lay a foundation for lineage-targeted analysis to investigate the role of epithelial layers and subtypes in fin regeneration.

For each cell type to be a consistent component in the regenerated fin, cell cycle entry is required. We found that both common and unique cell cycle programs activated in the regenerating fin, with the shared ones appearing to be more evolutionarily conserved than the unique ones. Among the genes showing cell typespecific S phase enrichment, several immunoproteasome subunits also showed a clear cell typespecific expression. We speculated that the increasing level of immunoproteasome subunits in epithelial and hematopoietic cells specifically might accelerate antigen processing and presentation, which could be important for immune cell recruitment and tumor necrosis factorinduced blastemal proliferation (54).

Epithelial cells were the most abundant cell type in the profiled fins and could be clustered into four different subgroups, including the three layers in the adult fish epithelium and the mucosal-like cells within the intermediate layer. However, markers labeling these layers did not perform well in separating cell groups when only regenerating cells were considered. An unbiased differential expression test suggested that some members of the krt and cldn families were expressed in specific layers more consistently throughout regeneration. RNA in situ hybridization targeting cldne, krt1-19d, cldna, krt94, cldni, and cldn1 confirmed their exclusive layer-specific expression pattern, underscoring their potential to serve as markers for the distinct epithelial layers during regeneration. Our epithelium-specific analysis suggested that basal layer epithelial cells proliferate and could be the main source for replenishing the other two layers of the epithelium, similar to findings in a previous study based on genetic lineage tracing in zebrafish and echoing findings made using the axolotl limb regeneration model (25, 55). We observed higher apoptosis and lower proliferation features in the superficial epithelial layer compared to the other layers. At the same time, we observed transition patterns in gene expression, connecting the basal to the intermediate and the superficial layer during regeneration.

The behavior of mucosal-like cells during regeneration had been rarely reported for zebrafish in literature. We found in this study that this group of cells was an integral part of the regeneration process. Enrichment of foxp1b in this population and enrichment of foxp4 in basal and intermediate epithelial cells supported that zebrafish foxp homologs could be involved in regulating agr2 expression as does the Fox family in mice and, furthermore, the mucin production in the epithelium during regeneration (Fig. 1E) (56). The protein encoded by amphibian homologs of agr2, nAG (from newts) and aAG (from axolotl), are necessary and sufficient for salamander limb regeneration (57, 58). They are expressed in both dermal glands and the nerve sheaththe pattern of which has also been recovered from single-cell RNA sequencing (scRNA-seq) analysis (55). Regeneration deficiencies caused by denervation before amputation can be rescued by the ectopic expression of nAG. Although we do not have data supporting the nerve sheath expression pattern, as shown for the amphibian models, we hypothesize that agr2 could similarly mediate neuronal signals in zebrafish during regeneration.

Macrophages are critical players in the zebrafish caudal fin regeneration (28, 54). We observed subgroups of the mpeg1.1+ macrophage population in the regenerating fin tissue, resembling M1 and M2 macrophages in mammalian systems. However, we were not able to recover other immune cell population in the hematopoietic cells. This could potentially be due to the systematic bias against certain cell types during tissue dissociation and droplet incorporation in the microfluidic device. The same bias might also explain why we were not able to recover some other known players in the regenerating fin tissue, including neurons and endothelial cells (4). Increasing the number of cells sampled for scRNA-seq or performing scRNA-seq on sorted hematopoietic lineage cells would help to better understand the involvement of these populations in the regeneration process.

The expression profiles of mesenchymal cells captured from the postinjury stages resembled those of blastema in histology studies. We found four connected but distinct lineages representing both bone and non-bone cells in the blastema. All four lineages initiated from one cluster mostly consisted of 1-dpa cells and enriched for the tnfaip6 expression. A similar scenario has been observed in the axolotl limb regeneration model. By using scRNA-seq on a lineage-labeled axolotl model, Gerber et al. (58) found that connective tissue cells funnel into a progenitor state at initiation. Whether the cluster identified in our study represented a shared cell origin for the blastema or a shared state across mesenchymal cell types in the initial blastema-formation stage requires further investigation. High proportion of epithelial population in the fins could also hamper the discovery of relatively rare population with multipotency. Finer dissection before single-cell profiling might help in future study designs in capturing these populations.

While the bone cell lineage has been well studied in the regenerating fin, non-bone cells had been labeled by different markers and given different names and their intercorrelations left to be clarified. We found that tph1b, aldh1a2, and and1/and2 genes were shared among the non-bone cell lineages and could be labeling states instead of types of blastemal cells during regeneration. Meanwhile, differential analysis revealed similar enrichment for bone formation in all lineages yet distinct associations with reactivation of developmental programs, RA signaling, and collagen metabolism, underscoring their collaborative and complementary roles in the regeneration process.

Our scRNA-seq data also provided more details about the fish system we are working with. For all sample collections, we used the transgenic strain Tg(sp7:EGFP)b1212, which specifically labels osteoblast lineage in the fish (59). It was reported that green fluorescence signal could be detected in the fish skin after 72 hours post-fertilization. This ectopic expression, however, does not interfere with confocal imaging of skeletal structures of fish at any stage due to the fact that they lie in different planes of focus. What these cells are and why they expressed the transgene were unclear. In this study, we obtained a holistic view of the transgene expression pattern in the fin region regardless of whether that was associated with the cell type of interest, i.e., osteoblasts in this context. Unsupervised clustering on the expression profiles from single fin cells suggested that green fluorescent protein (GFP) is not only expressed in the mesenchymal but also highly enriched in the superficial layer epithelium (table S2). A closer examination of this classic reporter gene construct revealed that the regulatory region of sp7 used for the construction of the transgene did not exactly represent the endogenous sp7 regulatory region. Tg(sp7:EGFP)b1212 was generated from bacterial artificial chromosome transgenesis using CH73-243G6 as the backbone, which did not contain the first exon of sp7 according to the annotation of the current genome assembly (chr6:58630884-58720045 and GRCz10), leading to the usage of a regulatory sequence different from the endogenous version. Whether this usage difference contributed to the ectopic expression pattern of the transgene requires further study. This finding points to the potential of using single-cellbased approaches in reporter line validation and more thorough analysis of the transgene behavior.

All zebrafish were used in accordance with protocol no. 20190041 approved by the Washington University Institutional Animal Care and Use Committee. Wild-type and Tg(sp7:EGFP) strains are maintained under standard husbandry in the Washington University Fish Facility, with the system water temperature at 28.5C and a day-night cycle controlled as 14-hour light/10-hour dark. For fin amputation, we anesthetized 1-year-old fish with MS-222 (0.16 g/liter) in the system water and then removed the distal half of their caudal fin with sterilized razor blades. The fish were then sent back to circulating water system for recovery. We collected regenerating fin tissue from 39 fish by doing secondary fin amputation at the primary cutting plane with the same anesthesia and recovery procedures.

Collected fin tissues were digested by Accumax (Innovative Cell Technologies), filtered through 40-m cell strainers, and washed with 1 Dulbeccos phosphate-buffered saline (DPBS)0.04% bovine serum albumin to generate single-cell suspensions. Libraries were constructed from these cell suspensions following the instruction of the Chromium Single Cell Gene Expression Solution 3 v2 (10x Genomics) and were subsequently sequenced on HiSeq2500 (Illumina) with read lengths of 26 + 75 (Read1 + Read2). Raw reads were processed by Cell Ranger (10x Genomics) with default parameters for read tagging, alignment to zebrafish reference genome (GRCz10), and feature counting based on Ensembl release 91 (cellranger count). EGFP sequence was added into the reference genome as a separate chromosome for mapping reads from the reporter gene.

We performed unsupervised clustering using Seurat v3.0 following the procedure of normalization (SCTransform), highly variable gene detection, dimensional reduction (principal components analysis), and cells clustering (Louvain clustering at resolutions from 0.1 to 0.6) (17). For integrating the four stages in finding conserved cell types, we used the anchoring approach provided by Seurat v3. Cell clustering was based on the top principal components that account for most of the cell-cell variances. The same set of principal components was used in UMAP calculation for visualization as well.

We found differentially expressed genes in each cluster by comparing the expression profiles of them with those of the rest of the cells using Wilcoxon rank sumbased approach with the criteria of log fold change more than 0.25 and a minimum cell percentage of 0.25. The same criteria were applied to all pairwise comparisons, unless stated otherwise. We made functional connections between the list of differentially expressed genes and the type of cell that they most likely represent by testing for GO term enrichment (18) and manual curation by searching The Zebrafish Information Network database and PubMed. Certain cell clusters were taken as independent samples for secondary clustering following the same unsupervised clustering procedures.

We calculated the by-cell average expression level of a set of S phase or G2-M phase markers suggested by Seurat that are detected in our zebrafish dataset and normalized by subtracting aggregated expression of control genes. Although G1 phase cells are also within cell cycle, they are hardly separable from G0 cells. To avoid false-positive labeling for active cycling cells, we set stringent thresholds and only included cells with |S.score G2M.score| > 0.1 in the S or G2-M group, while cells with both S.score and G2M.score below zero as G1. Other cells were not included in this part of the analysis. Differentially expressed genes were also identified by Wilcoxon rank sumbased approach. These differentially expressed genes were considered to be cell cycle related if they were in the list of genes associated with R-DRE-1640170 Cell Cycle and/or cycling marker genes used for cell cycle phase score calculations.

We collected uninjured and regenerating fin tissues from casper (nacrew2/w2;roya9/a9) fish and fixed in 4% paraformaldehyde overnight (60). Fixed tissues were subsequently submerged in 10% sucrose in 1 PBS, 20% sucrose in 1 PBS, and 30% sucrose in 1 PBS for 4 hours each. After sucrose exchange, tissues were embedded in Optimal Cutting Temperature (O.C.T.) compound (Fisher Healthcare Tissue-Plus) and snap frozen on dry ice. The frozen tissue blocks were then processed into 15-m sections on a Leica CM1950 cryostat. We performed RNA in situ hybridization targeting krt4, cldne, krt1-19d, cldna, krt94, cldni, cldn1, agr2, sema3b, stmn1b, and tnfaip6 for mRNA detection using an RNAscope kit (Advanced Cell Diagnostics, Hayward, CA, USA). Alcian blue/periodic acidSchiff (PAS) staining was subsequently performed on the same section or separately on a consecutive serial section following the manufacturers protocol (Newcomer Supply). Microscopic images were taken by ZEISS Axio Observer.

Cell trajectories were constructed using Slingshot v1.3.1 (40). Through initial subclustering and cell type identifications, we found one subcluster with high epcam expression, potentially a doublet cell contamination from the major cell type classifications. We removed this group of cells from all downstream analysis within the mesenchymal cluster. We used UMAP embedding and subclustering assignments as input for the Slingshot calculation.

We performed nonparametric Wilcoxon rank sum test to identify differentially expressed genes across cell groups as implemented in Seurat. P values were adjusted by all features in the dataset using Bonferroni correction.

See the article here:
Cellular diversity of the regenerating caudal fin - Science Advances

Bone Marrow Stem Cells Comments Off on Cellular diversity of the regenerating caudal fin – Science Advances | August 13th, 2020

Some skin, eggs and tissue samples are all that remain of Malaysia's last rhino, Iman, who died last November after years of failed breeding attempts.

Now scientists are pinning their hopes on experimental stem cell technology to bring back the Malaysian variant of the Sumatran rhinoceros, making use of cells from Iman and two other dead rhinos.

"I'm very confident," molecular biologist Muhammad Lokman Md Isa told Reuters in his laboratory at the International Islamic University of Malaysia.

"If everything is functioning, works well and everybody supports us, it's not impossible."

The smallest among the world's rhinos, the Sumatran species was declared extinct in the wild in Malaysia in 2015. Once it had roamed across Asia, but hunting and forest clearance reduced its numbers to just 80 in neighboringIndonesia.

Iman, 25, died in a nature reserve on Borneo island, following massive blood loss caused by uterine tumors, within six months of the death of Malaysia's last male rhino, Tam.

Efforts to get the two to breed had not worked.

"He was the equivalent of a 70-year-old man, so of course you don't expect the sperm to be all that good," said John Payne of the Borneo Rhino Alliance (BORA), who has campaigned for about four decades to save Malaysia's rhinos.

"It was obvious that, to increase the chances of success, one should get sperm and eggs from the rhinos inIndonesia. But right till today,Indonesiais still not keen on this."

Across the border

Indonesia's environment ministry disputed accusations of cross-border rivalry as a reason why Malaysia's rhinos died out, saying talks continue on ways to work with conservationists in the neighboring southeast Asian nation.

"Because this is part of diplomatic relations, the implementation must be in accordance with the regulation of each country," said Indra Exploitasia, the ministry's director for biodiversity conservation.

The Malaysian scientists plan to use cells from the dead rhinos to produce sperm and eggs that will yield test-tube babies to be implanted into a living animal or a closely related species, such as the horse.

The plan is similar to one for the African northern white rhinoceros, which number just two. Researchers in that effort reported some success in 2018 in producing embryonic stem cells for the southern white rhino.

But the process is still far from producing a whole new animal, say Thomas Hildebrandt and Cesare Galli, the scientists leading the research.

And even if it worked, the animals' lack of genetic diversity could pose a threat to long-term survival, Galli told Reuters.

Indonesian scientist Arief Boediono is among those helping in Malaysia, hoping success will provide lessons to help his country's rhinos.

"It may take five, 10, 20 years, I don't know," Arief added. "But there has already been some success involving lab rats in Japan, so that means there is a chance."

Japanese researchers have grown teeth and organs such as pancreas and kidneys using embryonic stem cells from rats and mice in efforts to grow replacement human organs.

For now, however, Iman's hide will be stuffed and put on display alongside Tam in a Borneo museum.

Your premium period will expire in 0 day(s)

Subscribe to get unlimited access Get 50% off now

See original here:
Back from the dead? Stem cells give hope for revival of Malaysia's extinct rhinos - The Jakarta Post - Jakarta Post

Skin Stem Cells Comments Off on Back from the dead? Stem cells give hope for revival of Malaysia’s extinct rhinos – The Jakarta Post – Jakarta Post | August 13th, 2020

Aug 13 (Reuters) - Every week, Reuters journalists produce scores of multimedia features and human-interest stories from around the world.

Below are some engaging stories selected by our editors, as well as explanatory context and background on world headlines. For a full schedule of news and events, please go to our editorial calendar on Reuters Connect here

Baby George, born amid Beirut blast, is light in the darkness

BEIRUT, Aug 12 - Stepping into the delivery room where his wife Emmanuelle was about to give birth, Edmond Khnaisser meant to capture their sons first moments on camera. Instead, he recorded the instant the biggest blast in Lebanons history sent windows crashing onto the hospital bed. (LEBANON-SECURITY/BLAST-BABY (TV, PIX), moved, 401 words)

Squeegee selfies: Tel Aviv tower-washer is rising TikTok star

TEL AVIV, Aug 11 - Twirling to hip hop over chasms of steel and glass, soapy squeegee in one hand and a smartphone in the other, Noa Toledo is an Israeli social media star who aims to encourage other women to take on her traditionally male-dominated job. (ISRAEL-SOCIALMEDIA/WINDOW WASHER (TV, PIX), moved, 155 words)

From carats to peanuts: how a pandemic upended the global diamond industry

JOHANNESBURG/MUMBAI, Aug 12 - As the coronavirus pandemic shuttered mines from Lesotho to Canada and disrupted supply chains, Rajen Patel swapped diamond polishing for peanut farming. (HEALTH-CORONAVIRUS/DIAMONDS (PIX, GRAPHICS), by Helen Reid, Tanisha Heiberg and Rajendra Jadhav, 828 words)

Raphael did a nose-job in self-portrait, face reconstruction suggests

ROME, Aug 11 - Raphael probably didnt like his nose, and replaced it with an idealised version in his famous self-portrait. (ARTS-ITALY/RAPHAEL (PIX, TV), by Philip Pullella, 399 words)

Back from the dead? Stem cells give hope for revival of Malaysias extinct rhinos

KUANTAN, Malaysia, Aug 12 - Some skin, eggs and tissue samples are all that remain of Malaysias last rhino, Iman, who died last November after years of failed breeding attempts. (MALAYSIA-WILDLIFE/RHINO (TV, PIX), by Joseph Sipalan, 517 words)

Dream destination cafes offer taste of paradise in blockaded Gaza strip

GAZA, Aug 11 - Mediterranean waves crash below patrons snacking on freshly-caught fish at the Maldive Gaza cafe, offering a glimpse of paradise to Palestinians confined to the blockaded strip. (PALESTINIANS-GAZA/MALDIVES (TV, PIX), by Nidal al-Mughrabi, 207 words)

Virtually identical: Grounded Japanese try foreign holidays with a difference

TOKYO, Aug 12 - Japanese businessman Katsuo Inoue chose Italy for this years summer vacation, and he enjoyed the trimmings of a business class cabin and soaked up the sights of Florence and Rome - without ever leaving Tokyo. (HEALTH CORONAVIRUS/JAPAN-VR TRAVEL (TV, PIX), by Akira Tomoshige, 296 words)

For the art collector with everything, the $1.5 million COVID mask

MOTZA, Israel, Aug 12 - Art rather than ostentation is the rationale behind the worlds most expensive coronavirus mask, say the Israeli jewellers who are crafting the $1.5 million object for an unnamed U.S.-based client. (HEALTH-CORONAVIRUS/ISRAEL-MASK (TV, PIX), moved, 234 words)

Coping with campus coronavirus: U.S. fraternities, sororities give it the old college try

MADISON, Wisconsin, Aug 12 - Sixteen gallons of hand sanitizer sat in the foyer of the Alpha Epsilon Phi sorority house at the University of Wisconsin as house mother Karen Mullis reconfigured tables in the dining room to maintain social distancing. (HEALTH-CORONAVIRUS/FRATERNITIES-SORORITIES (PIX, GRAPHIC), by Brendan OBrien, 754 words)

Some U.S. colleges stick to in-person reopening in pandemic despite doubts, pushback

Aug 11 - Many U.S. universities are revamping campuses to resume in-person classes despite COVID-19, drawing criticism from some college town residents and critics who say schools are putting profits before public safety. (HEALTH-CORONAVIRUS/UNIVERSITIES (PIX, TV, GRAPHIC), by Jan Wolfe and Catherine Koppel, 729 words)

EXPLAINER-The U.S. push to extend U.N. arms embargo on Iran

Where Biden and Trump stand on key issues (tmsnrt.rs/3iDd4YG)

FACTBOX-Who is speaking at the Democratic National Convention - and why

NEWSMAKER-How Kamala Harris found the political identity that had eluded her

FACTBOX-Political crisis unfolds in Belarus after presidential vote

EXPLAINER-Microsofts TikTok bid spotlights Windows makers history with China

FACTBOX-Who is Jimmy Lai, the media tycoon arrested in Hong Kong?

FACTBOX-How financial firms in Hong Kong may be affected by U.S. sanctions

UNDERSTANDING COVID-19

EXPLAINER-When will a coronavirus vaccine be ready?

FACTBOX-World reaction to Russias COVID-19 vaccine

FACTBOX-U.S., UK spend billions to take lead in securing coronavirus vaccines

GRAPHIC-U.S. COVID-19 deaths drop for first time in four weeks (tmsnrt.rs/2WTOZDR)

The Lifeline Pipeline: the drugs, tests and tactics that may conquer coronavirus (reut.rs/3bhMUaE)

Coronavirus and the global economy (tmsnrt.rs/3cg7OXF)

The new normal: How far is far enough? (tmsnrt.rs/3dKqnnn)

Prominent people diagnosed with COVID-19

Global tracker (tmsnrt.rs/2W82n73)

U.S. tracker (tmsnrt.rs/2ySIhG0) (Compiled by Leela de Kretser, Patrick Enright and Tiffany Wu)

Follow this link:
IN CASE YOU MISSED ITSchedule of Reuters features from this week - Reuters

Skin Stem Cells Comments Off on IN CASE YOU MISSED ITSchedule of Reuters features from this week – Reuters | August 13th, 2020

Is it acne, a rash or maybe something more serious? Skin disorders can vary in both symptoms and severity. Some skin conditions are minor, some are serious but treatable, and others, like skin cancer, can be life-threatening. Here are 18 common (and a few less common) skin conditions with photos to help you ID them. Remember to always reach out to your physician for a proper diagnosis and treatment.

Acne | Actinic keratosis | Basal cell carcinoma | Blisters | Carbuncle | Cellulitis | Chicken pox | Cold sores | Contact dermatitis | Eczema | Hives | Latex allergy | Lupus | Measles | Melanoma | Psoriasis | Rosacea | Squamous cell carcinoma

Suffering from acne? Youre not alone. Acne is the most common condition dermatologists treat 40 to 50 million Americans struggle with acne at any given time.

Acne can show up almost anywhere on the skin as blackheads, papules and pustules or pimples, cysts and nodules

Acne starts when dead skin cells dont shed properly and clog your pores.

Some acne can be treated with over-the-counter products, while others require professional help, including prescription medication and treatments.

Read more about acne and how to treat it.

These precancerous lesions often appear as rough spots on the skin. Actinic keratosis is common, but if left untreated it can turn into squamous cell carcinoma.

The appearance of actinic keratosis can vary from bumps that look like pimples or acne to rough lesions that are red, pink or gray.

When cells in the skin called keratinocytes are damaged by UV rays, it can cause actinic keratosis.

While not always necessary, treatments may include removal of the actinic keratosis with liquid nitrogen, chemical peels, scraping or other therapies.

Read more about actinic keratosis and how to treat it.

Basal cell carcinoma is the most common type of skin cancer. It affects approximately 2.6 million people in the U.S. each year. Do you know how to spot it?

Basal cell carcinoma is much more common in people who have light skin. Symptoms tend to be the same color as the skin or pink. Its important to look for any changes in your skin.

Exposure from ultraviolet rays (UV) from the sun or indoor tanning is a primary cause of basal cell carcinoma.

Your dermatologist may be able to remove a basal cell carcinoma tumor when doing a biopsy. Sometimes a Mohs surgery is recommended.

Read more about basal cell carcinoma and how to spot it.

A common skin condition, most people develop blisters once in a while.

Blisters are small, painful sacs of fluid.

Blisters can be caused by friction, such as by a shoe rubbing against the skin, or by sunburns, heat or skin diseases.

Blisters tend to heal on their own, but a blister can be drained if its too painful.

Read more about blisters and how to treat them.

Sometimes confused with a spider bite, a carbuncle is a group of boils that stem from an infection of the skin and are connected to each other.

Red, tender bumps, or boils, that contain pus are signs of a carbuncle. Carbuncles can eventually rupture, and pus will leak out of them.

A bacterial infection, such as Staphylococcus aureus, is often the cause of a carbuncle.

If a carbuncle is small, you may be able to treat it at home with warm compresses and bandages. Otherwise, your dermatologist can make an incision to drain the pus.

Read more about carbuncles and how to treat them.

Cellulitis is an infection of the skin in which the skin becomes red and swollen. It typically occurs after you get a cut or wound.

When you have cellulitis, an area of your skin often on one of your legs becomes red, swollen, warm and possibly painful.

Cellulitis can be caused by two different types of bacteria: streptococcus (aka strep) or staphylococcus (aka staph).

Antibiotics like penicillin, cephalosporin or erythromycin are normally used to treat cellulitis.

Read more about cellulitis and how to treat it.

Also called varicella, this highly contagious disease mostly strikes children.

A fever may precede it, but the unique chicken pox rash appears on the skin with itchy blisters that look like lots of little dew drops.

The varicella-zoster virus (VZV) causes chicken pox as well as shingles. Its unlikely to get chicken pox if youve had the chicken pox vaccine.

The best treatment for chicken pox is prevention through vaccination. An early case of chicken pox may be treated with antiviral drugs. Other remedies can be used to ease symptoms.

Read more about chicken pox and how to treat it.

Trending stories,celebrity news and all the best of TODAY.

Also known as fever blisters, cold sores are blisters, or clusters of blisters, that appear on your lips or near your mouth.

Symptoms of cold sores can vary. The sores may start with a tingling, burning or other sensation, then break open and scab over.

Cold sores are caused by the herpes simplex virus. Outbreaks are triggered by stress, fatigue, illness and other factors.

Read more about cold sores and how to treat them.

Almost everyone gets contact dermatitis at some point. There are two main types of contact dermatitis allergic and irritant. Both trigger a rash.

Symptoms of allergic contact dermatitis may include itching, rash, dryness and other symptoms. Cracked, itchy, chapped skin with sores may be signs of irritant contact dermatitis.

Contact dermatitis is caused by something that touches your skin like poison ivy, nickel, fragrances, latex or other irritants and triggers a rash.

The best treatment for contact dermatitis is to avoid whatever it is that triggers your rash. Beyond that, your dermatologist may also recommend antihistamine pills, moisturizers or topical steroids.

Read more about contact dermatitis and how to treat it.

Eczema is a condition that causes red, itchy patches on the skin. It often starts at a young age often people with eczema get it when they're babies.

Eczema is almost always itchy, but otherwise symptoms can vary from person to person. Skin infected with eczema can be dry, dark, scaly, swollen or oozing.

Eczema may be caused by an overactive immune system, but its not entirely clear what causes the condition.

There is no cure for eczema, but symptoms can be managed with medications and other therapies.

Read more about eczema and how to treat it

The onset of hives can be mysterious, and though hives usually go away in less than 24 hours, new ones can repeatedly appear.

Hives appear on the skin as slightly swollen, raised pink or red patches. You may have one hive, a group of hives that may be separate or connected together.

Its difficult to pinpoint the cause of hives, but there are many triggers that can cause hives, from insect bites and allergic reactions to medication, stress and heat.

The go-to treatment for hives is usually antihistamines.

Read more about hives and how to treat them.

People with an allergy to latex are allergic to a protein found in the sap of the Brazilian rubber tree.

Different symptoms appear with different types of latex allergies. One type causes a rash on the skin; another can cause anaphylaxis, which can result in a swelling of the airways and difficulty breathing.

When your immune system reacts as though latex is a harmful substance, it causes an allergic reaction to latex.

Since theres no cure for latex allergies, your best bet is to avoid coming into contact with latex.

Read more about latex allergy and how to treat it.

An autoimmune disease that causes pain and inflammation, lupus can affect your skin, as well as your kidneys, heart, joints and lungs.

A red butterfly-shaped rash that appears on the nose and cheeks is one common sign of lupus, but symptoms of lupus will vary, depending on the type of lupus you have.

There are a number of factors that may play a role in whether you develop rosacea, but experts dont know for certain what causes the skin condition.

There is no cure for rosacea, but the condition can be managed to help keep symptoms from worsening.

Read more about lupus and how to treat it.

Also known as rubeola, measles is a contagious and potentially deadly disease that usually strikes children.

Beyond the signifying red, spotted rash, measles may also be accompanied by a fever, cough, runny nose and other symptoms.

A virus that infects the respiratory tract and spreads throughout the body causes measles. Its one of the most contagious diseases.

The best treatment is prevention through a vaccine. Otherwise, high doses of vitamin A, bed rest and medications to reduce pain and fever may help.

Read more about measles and how to treat it.

Its one of the less common skin cancers, but melanoma is the most dangerous because it can easily spread to other parts of your body.

Melanoma tumors tend to be black or brown, but can sometimes be pink, tan or white. Anyone can get melanoma, but people with light skin are at greater risk.

UV light exposure from ultraviolet rays from the sun or indoor tanning causes most melanomas.

Treatments depend on how advanced the melanoma is and where the tumor is located. It may include surgery, radiation, chemotherapy or other therapies.

Read more about melanoma and how to treat it.

Psoriasis affects more than 8 million people in the U.S. It typically starts in the teen years or early 20s, though it can occur at any age.

When you have psoriasis, your body makes new skin cells quickly, and the cells typically build up in thick, scaly patches on the skin called plaques.

There are a number of factors that may contribute to causing psoriasis. The immune system and genetics may play a role. Certain triggers can also cause the onset of psoriasis and psoriasis flare-ups.

Psoriasis doesnt have a cure, there are medications and treatments that can help manage the condition.

Read more about psoriasis and how to treat it.

This common inflammatory skin condition causes redness of the face.

In addition to causing facial redness, if rosacea is not treated, it can cause visible blood vessels, breakouts like acne and other symptoms.

There are a number of factors that may play a role in whether you develop rosacea, but experts dont know for certain what causes the skin condition.

There is no cure for rosacea, but the condition can be managed to help keep symptoms from worsening.

Read more about rosacea and how to treat it.

Also known as cutaneous squamous cell carcinoma, this cancer develops when the squamous cells in the top layer of your skin grow out of control.

Though its linked with exposure to ultraviolet rays, squamous cell carcinoma can crop up in areas that dont get much sun. Watch out for rough, scaly patches, sores that dont heal or anything else that looks suspicious.

Squamous cell carcinoma is mainly caused by UV rays from the sun or indoor tanning.

Treatments for squamous cell carcinoma may include surgery, radiation or other therapies. Catching it early is key.

Read more about squamous cell carcinoma and how to treat it.

Read the original:
Skin Disorders: Pictures, symptoms, causes and help - TODAY - TODAY

Skin Stem Cells Comments Off on Skin Disorders: Pictures, symptoms, causes and help – TODAY – TODAY | August 13th, 2020

After months of reviewing close to 300 beauty products and wellness facilities, and tallying, here are the best skincare products of this year, and lest we forget, your top pick! And so without further ado, here are the Beauty & Wellness Awards winners.

As technology continues to advance and discoveries are made each day,we do our part in dipping our toe in the proverbial pool of beauty toexplore the latest and greatest. Embracing the new is part of our job asinvestigative beauty aficionados, and as we dig through the recentdebuts, weve found some newbies that have found a permanent spot onour top shelf that we highly recommend checking out.

1

Best Face Cream: First Aid Beauty Ultra Repair Cream

For even the most sensitive skin, FAB delivers animpressive amount of hydration without anyirritation. The luscious whipped-cream texturespreads easily over the face, yet still holds wellenough for make-up to sit over nicely.

Ultra Repair Cream

HK$249/170g; HK$109/56.7G

2

Best Hydrating Serum: Skin Need 100% Hyaluronic Acid B5

The ultimate water magnet, thisserum locks in all the hydration youneed. Its easily absorbed, so yourskin feels fresh and clean without atrace of stickiness. The heavy doseof hyaluronic acid binds and trapsmoisture to the skin.

100% Hyaluronic Acid B5

HK$598

3

Best Reparative Formula: Wildsmith Skin Active Repair Radiance Polisher

Exfoliate to your hearts content and skinsneed the gentle grains of walnut shell androsehip-seed powder sloughs away deadskin cells and polishes the skins surface. Mixthe desired amount with any facial cleanserto create your very own scrub.

Skin Active Repair Radiance Polisher

HK$254

4

Best Body Cream: Augustinus Bader The Body Cream

A fresh launch from world-leadingstem cell and biomedical pioneerand scientist, Professor AugustinusBader, The Body Cream is officiallythe newest must-have item in bodyand skin care. Powered by thebrands patented Trigger FactorComplex (TFC8), this cellularrenewal cream reawakens dormantstem cells and results in firmer,toned skin with a reduction incellulite and stretch marks.

5

Readers Choice: Drunk Elephant F-balm

Electrolytes pump us full of hydration. And if its good to ingest. Why wouldnt it be topically? This waterfacial masque hydratant nourishes and repairs parched skin while you sleep. Its cooling effects are especially appreciated this season.

All of the Drunk Elephant products are naturally formulated and cater directly to your skins health. Oi Tak Kan, Prestige Reader

Read more:
Beauty & Wellness Awards 2020: New Kids on the Block - Prestige Online

Skin Stem Cells Comments Off on Beauty & Wellness Awards 2020: New Kids on the Block – Prestige Online | August 12th, 2020

KUANTAN, Malaysia Some skin, eggs and tissue samples are all that remain of Malaysia's last rhino, Iman, who died last November after years of failed breeding attempts.

Now scientists are pinning their hopes on experimental stem cell technology to bring back the Malaysian variant of the Sumatran rhinoceros, making use of cells from Iman and two other dead rhinos.

"I'm very confident," molecular biologist Muhammad Lokman Md Isa told Reuters in his laboratory at the International Islamic University of Malaysia.

"If everything is functioning, works well and everybody supports us, it's not impossible."

The smallest among the world's rhinos, the Sumatran species was declared extinct in the wild in Malaysia in 2015. Once it had roamed across Asia, but hunting and forest clearance reduced its numbers to just 80 in neighbouring Indonesia.

Iman, 25, died in a nature reserve on Borneo island, following massive blood loss caused by uterine tumours, within six months of the death of Malaysia's last male rhino, Tam.

Efforts to get the two to breed had not worked.

"He was the equivalent of a 70-year-old man, so of course you don't expect the sperm to be all that good," said John Payne of the Borneo Rhino Alliance (BORA), who has campaigned for about four decades to save Malaysia's rhinos.

"It was obvious that, to increase the chances of success, one should get sperm and eggs from the rhinos in Indonesia. But right till today, Indonesia is still not keen on this."

ACROSS THE BORDER

Indonesia's environment ministry disputed accusations of cross-border rivalry as a reason why Malaysia's rhinos died out, saying talks continue on ways to work with conservationists in the neighbouring southeast Asian nation.

"Because this is part of diplomatic relations, the implementation must be in accordance with the regulation of each country," said Indra Exploitasia, the ministry's director for biodiversity conservation.

The Malaysian scientists plan to use cells from the dead rhinos to produce sperm and eggs that will yield test-tube babies to be implanted into a living animal or a closely related species, such as the horse.

The plan is similar to one for the African northern white rhinoceros, which number just two. Researchers in that effort reported some success in 2018 in producing embyronic stem cells for the southern white rhino.

But the process is still far from producing a whole new animal, say Thomas Hildebrandt and Cesare Galli, the scientists leading the research.

And even if it worked, the animals' lack of genetic diversity could pose a threat to long-term survival, Galli told Reuters.

Indonesian scientist Arief Boediono is among those helping in Malaysia, hoping success will provide lessons to help his country's rhinos.

"It may take five, 10, 20 years, I don't know," Arief added. "But there has already been some success involving lab rats in Japan, so that means there is a chance."

Japanese researchers have grown teeth and organs such as pancreas and kidneys using embryonic stem cells from rats and mice in efforts to grow replacement human organs.

For now, however, Iman's hide will be stuffed and put on display alongside Tam in a Borneo museum.

(Editing by Matthew Tostevin and Clarence Fernandez)

Originally posted here:
Back From the Dead? Stem Cells Give Hope for Revival of Malaysia's Extinct Rhinos - The New York Times

Skin Stem Cells Comments Off on Back From the Dead? Stem Cells Give Hope for Revival of Malaysia’s Extinct Rhinos – The New York Times | August 12th, 2020

No roars at Augusta as Masters to be played without fansNews / 12 mins ago

1 dead, 1 injured in deputy-involved shooting in Anderson Co., K-9 shot and killedNews / 20 mins ago

Going On At The Greenville LibraryEntertainment / 1 hour ago

Work It Wednesday - Skin UndertonesEntertainment / 2 hours ago

It's back to the future or forward to the past on National Vinyl Record DayEntertainment / 2 hours ago

Wellness By Design - Help With Joint Pain Using Stem CellsEntertainment / 2 hours ago

Jamarcus Tells Us What He Has Been Up To In York County SCEntertainment / 2 hours ago

Race is on to make COVID-19 changes for November electionNews / 4 hours ago

Carolina Morning Weather Aug. 12Weather / 6 hours ago

'Put forth a little bit of effort': Greenville County Schools Superintendent talks virtual learning dress codeNews / 12 hours ago

Bentley tries taking PAC-12 shutdown in strideSports / 14 hours ago

HSRZ Team Preview: Wade Hampton GeneralsSports / 14 hours ago

See the original post:
Going On At The Greenville Library - WSPA 7News

Skin Stem Cells Comments Off on Going On At The Greenville Library – WSPA 7News | August 12th, 2020

In mouse studies, the specialized grafts integrated with host networks and behaved much like neurons in a healthy, undamaged spinal cord.

Using stem cells to restore lost functions due to spinal cord injury (SCI) has long been an ambition of scientists and doctors. Nearly 18,000 people in the United States suffer SCIs each year, with another 294,000 persons living with an SCI, usually involving some degree of permanent paralysis or diminished physical function, such as bladder control or difficulty breathing.

In a new study, published August 5, 2020 in Cell Stem Cell , researchers at University of California San Diego School of Medicine report successfully implanting highly specialized grafts of neural stem cells directly into spinal cord injuries in mice, then documenting how the grafts grew and filled the injury sites, integrating with and mimicking the animals existing neuronal network.

Until this study, said the studys first author Steven Ceto, a postdoctoral fellow in the lab of Mark H. Tuszynski, MD, PhD, professor of neurosciences and director of the Translational Neuroscience Institute at UC San Diego School of Medicine, neural stem cell grafts being developed in the lab were sort of a black box.

Although previous research, including published workby Tuszynski and colleagues, had shown improved functioning in SCI animal models after neural stem cell grafts, scientists did not know exactly what was happening.

We knew that damaged host axons grew extensively into (injury sites), and that graft neurons in turn extended large numbers of axons into the spinal cord, but we had no idea what kind of activity was actually occurring inside the graft itself, said Ceto. We didnt know if host and graft axons were actually making functional connections, or if they just looked like they could be.

Ceto, Tuszynski and colleagues took advantage of recent technological advances that allow researchers to both stimulate and record the activity of genetically and anatomically defined neuron populations with light rather than electricity. This ensured they knew exactly which host and graft neurons were in play, without having to worry about electric currents spreading through tissue and giving potentially misleading results.

They discovered that even in the absence of a specific stimulus, graft neurons fired spontaneously in distinct clusters of neurons with highly correlated activity, much like in the neural networks of the normal spinal cord. When researchers stimulated regenerating axons coming from the animals brain, they found that some of the same spontaneously active clusters of graft neurons responded robustly, indicating that these networks receive functional synaptic connections from inputs that typically drive movement. Sensory stimuli, such as a light touch and pinch, also activated graft neurons.

We showed that we could turn on spinal cord neurons below the injury site by stimulating graft axons extending into these areas, said Ceto. Putting all these results together, it turns out that neural stem cell grafts have a remarkable ability to self-assemble into spinal cord-like neural networks that functionally integrate with the host nervous system. After years of speculation and inference, we showed directly that each of the building blocks of a neuronal relay across spinal cord injury are in fact functional.

Tuszynski said his team is now working on several avenues to enhance the functional connectivity of stem cell grafts, such as organizing the topology of grafts to mimic that of the normal spinal cord with scaffolds and using electrical stimulation to strengthen the synapses between host and graft neurons.

While the perfect combination of stem cells, stimulation, rehabilitation and other interventions may be years off, patients are living with spinal cord injury right now, Tuszynski said. Therefore, we are currently working with regulatory authorities to move our stem cell graft approach into clinical trials as soon as possible. If everything goes well, we could have a therapy within the decade.

Co-authors of the study are Kohel J. Sekiguchi and Axel Nimmerjahn, Salk Institute for Biological Studies and Yoshio Takashima, UC San Diego and Veterans Administration Medical Center, San Diego.

Funding for this research came, in part, from Wings for Life, the University of California Frontiers of Innovation Scholars Program, the Veterans Administration (Gordon Mansfield Spinal Cord Injury Collaborative Consortium, RR&D B7332R), the National Institutes of Health (grants NS104442 and NS108034), The Craig H. Neilsen Foundation, the Kakajima Foundation, the Bernard and Anne Spitzer Charitable Trust and the Dr. Miriam and Sheldon G. Adelson Medical Research Foundation.

Source: Scott LaFee, UC San Diego School of Medicine

Posted on August 5th, 2020 in Uncategorized.

See the article here:
Stem Cell Grafts Show Functionality in Spinal Cord Injuries

Spinal Cord Stem Cells Comments Off on Stem Cell Grafts Show Functionality in Spinal Cord Injuries | August 12th, 2020

Colorized scanning electron micrograph of a cultured human neuron. Photo credit: Thomas Deerinck, UC San Diego National Center for Microscopy and Imaging

Using stem cells to restore lost functions due to spinal cord injury (SCI) has long been an ambition of scientists and doctors. Nearly 18,000 people in the United States suffer SCIs each year, with another 294,000 persons living with an SCI, usually involving some degree of permanent paralysis or diminished physical function, such as bladder control or difficulty breathing.

In a new study, published August 5, 2020 in Cell Stem Cell, researchers at University of California San Diego School of Medicine report successfully implanting highly specialized grafts of neural stem cells directly into spinal cord injuries in mice, then documenting how the grafts grew and filled the injury sites, integrating with and mimicking the animals existing neuronal network.

Until this study, said the studys first author Steven Ceto, a postdoctoral fellow in the lab of Mark H. Tuszynski, MD, PhD, professor of neurosciences and director of the Translational Neuroscience Institute at UC San Diego School of Medicine, neural stem cell grafts being developed in the lab were sort of a black box.

Although previous research, including published work by Tuszynski and colleagues, had shown improved functioning in SCI animal models after neural stem cell grafts, scientists did not know exactly what was happening.

We knew that damaged host axons grew extensively into (injury sites), and that graft neurons in turn extended large numbers of axons into the spinal cord, but we had no idea what kind of activity was actually occurring inside the graft itself, said Ceto. We didnt know if host and graft axons were actually making functional connections, or if they just looked like they could be.

Ceto, Tuszynski and colleagues took advantage of recent technological advances that allow researchers to both stimulate and record the activity of genetically and anatomically defined neuron populations with light rather than electricity. This ensured they knew exactly which host and graft neurons were in play, without having to worry about electric currents spreading through tissue and giving potentially misleading results.

They discovered that even in the absence of a specific stimulus, graft neurons fired spontaneously in distinct clusters of neurons with highly correlated activity, much like in the neural networks of the normal spinal cord. When researchers stimulated regenerating axons coming from the animals brain, they found that some of the same spontaneously active clusters of graft neurons responded robustly, indicating that these networks receive functional synaptic connections from inputs that typically drive movement. Sensory stimuli, such as a light touch and pinch, also activated graft neurons.

We showed that we could turn on spinal cord neurons below the injury site by stimulating graft axons extending into these areas, said Ceto. Putting all these results together, it turns out that neural stem cell grafts have a remarkable ability to self-assemble into spinal cord-like neural networks that functionally integrate with the host nervous system. After years of speculation and inference, we showed directly that each of the building blocks of a neuronal relay across spinal cord injury are in fact functional.

Tuszynski said his team is now working on several avenues to enhance the functional connectivity of stem cell grafts, such as organizing the topology of grafts to mimic that of the normal spinal cord with scaffolds and using electrical stimulation to strengthen the synapses between host and graft neurons.

While the perfect combination of stem cells, stimulation, rehabilitation and other interventions may be years off, patients are living with spinal cord injury right now, Tuszynski said. Therefore, we are currently working with regulatory authorities to move our stem cell graft approach into clinical trials as soon as possible. If everything goes well, we could have a therapy within the decade.

Co-authors of the study are Kohel J. Sekiguchi and Axel Nimmerjahn, Salk Institute for Biological Studies and Yoshio Takashima, UC San Diego and Veterans Administration Medical Center, San Diego.

Funding for this research came, in part, from Wings for Life, the University of California Frontiers of Innovation Scholars Program, the Veterans Administration (Gordon Mansfield Spinal Cord Injury Collaborative Consortium, RR&D B7332R), the National Institutes of Health (grants NS104442 and NS108034), The Craig H. Neilsen Foundation, the Kakajima Foundation, the Bernard and Anne Spitzer Charitable Trust and the Dr. Miriam and Sheldon G. Adelson Medical Research Foundation.

Original post:
Implanted Neural Stem Cell Grafts Show Functionality in ...

Spinal Cord Stem Cells Comments Off on Implanted Neural Stem Cell Grafts Show Functionality in … | August 12th, 2020

Although spinal cord injuries (SCI) are not as prevalent as other debilitating conditions, they can be particularly devastating. Patients often lose motor control and sensibility and require assistance with everyday tasks. Most people are familiar with the case of Christopher Reeve, an American actor who played Superman in the 70s and 80s. He suffered a cervical spinal cord injury and was left paralyzed from the neck down. Reeve became an advocate for research into a potential cure using stem cells.

The World Health Organization estimates that every year up to 500,000 people suffer this type of injury worldwide. In Canada, approximately 85,000 people are currently living with some type of SCI.

The possibility of repairing damage sustained by the spinal cord is one of the most exciting potential applications of regenerative medicine. There have been promising advancements in this field and it is just a matter of time before they give way to actual treatments. Access to these treatments is just one of the many advantages of cell banking.

Inside the spinal column, which runs from the base of the skull to the coccyx, lies a fragile structure made up of nervous tissue. This is the spinal cord. Its job is to carry nerve signals from the brain to the rest of the body.

The spinal cord is very delicate and while it is protected by the vertebrae, it can easily be damaged either by trauma or disease. Injuries are graded according to their severity on a scale designed by the American Spinal Injury Association (ASIA) that goes from A to E (A being a complete injury, where all motor and sensory function is lost. E represents normal function). The severity of the injury is inversely correlated with the probability of recovery. According to the American Association of Neurological Surgeons, nearly half of all spinal cord injuries are complete.

In addition to the physical damage, spinal cord injuries are incredibly challenging in psychological terms. The more severe the injury, the more likely it is that the individual will lose the ability to care for himself. As reported in Mayo Clinic Proceedings, adults with spinal cord injury are at a higher risk of developing mental health disorders. Additionally, the rate of suicide increases three-fold among patients with this type of injury compared to the general population.

In a study published in Topics in Spinal Cord Injury Rehabilitation, researchers from the University of Alabama analyzed data from patients that sustained spinal cord injuries from 2005 to 2011. They found that automobile crashes (31.5% of cases) and falls (25.3%) account for more than half of all incidents. Other common causes are gunshot wounds, motorcycle crashes, and diving accidents. Although not frequent, diseases can cause spinal cord injury as well, specifically cancer, and osteoporosis.

Considering all causes, men account for 8 out of every 10 cases of spinal cord injury. Additionally, according to the Mayo Clinic, people are more likely to suffer traumatic cord injuries between the ages of 16 and 30. Avoiding risky behavior is the most effective strategy for preventing spinal cord injury.

In addition to the ASIA scale, which ranks injury by the severity of the damage, spinal cord injuries can be classified depending on the area affected. There are four types of spinal cord injury: cervical, thoracic, lumbar, and sacral.

The uppermost portion of the spine (vertebrae C1 to C7) is called the cervical section. Traumatic cord injuries in this area can lead to quadriplegia or full paralysis. This is the sort of injury that actor Christopher Reeve sustained. He shattered his C-1 and C-2 vertebrae in a horseback riding accident. Baseball player Roy Campanella damaged his C-5 and C-6 vertebrae in an automobile accident.

The thoracic spine is comprised of 12 vertebrae (T-1 to T-12) and it is located below the cervical section. An injury to this area could result in loss of use of the chest, upper back, and abdominals.

The lumbar section of the spine is located in the lower back. It comprises five vertebrae (L1 to L5). An injury to this area can leave an individual paraplegic, unable to move or feel anything below the point of injury. Deng Pufang, son of Chinas former leader Deng Xiaoping, suffered a lumbar spinal cord injury and became paralyzed.

The sacral section is located between the lumbar section and the coccyx. Injury to this area may cause loss of function in the hips and legs. Bladder function may be compromised as well. Injuries to this section of the spine are less common than cervical, thoracic, or lumbar injuries.

A discovery made by researchers John B. Gurdon and Shinya Yamanaka, for which they won the 2012 Nobel Prize in Medicine, may hold the key to repairing spinal cord injury. They found a way to induce adult cells, like those located in your hair follicles, to become pluripotent. Once this happens, these cells, called induced pluripotent stem cells (iPSCs), can become any cell type in the body.

A team of researchers from Keio University in Japan injected mice that had suffered spinal cord injury with neural cells derived from human iPSCs. These cells were able to successfully migrate and differentiate into their appropriate neural lineages, and they performed synapses. This means that they became exactly the type of cell needed in the place of injury and they successfully communicated with each other.

According to the scientists, compared to the control group, the mice injected with iPSCs had a significantly better functional recovery. The results of this trial, published in Proceedings of the National Academy of Sciences of the United States of America, are a step forward in the path towards eventually promoting complete functional recovery of spinal cord injury in humans.

Once this method is perfected and made available to the public, doctors will need a cell sample that they can turn into neural cells to treat people who suffer from spinal cord injury. It is important to note that the sooner that sample is taken and preserved, the higher its therapeutic potential will be, not only to treat spinal cord injury but many other conditions like Parkinsons, Alzheimers and macular degeneration.This means that the sooner you take action and have your live cells cryopreserved, the better prepared you will be to take advantage of the revolution of regenerative medicine that is coming. To learn more about the ways you can have your cells banked at Acorn, click here.

See original here:
Repairing damage caused by spinal cord injury with stem cells

Spinal Cord Stem Cells Comments Off on Repairing damage caused by spinal cord injury with stem cells | August 12th, 2020