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A high-level meeting has paved the way for global trials to begin on hundreds of patients.

British scientists have found a way to use stem cells to repair damaged tissue which could help millions living with heart failure, the UKs leading cause of death.

Scarring due to disease or heart attacks affects more than two million people in Britain.

This would be the biggest breakthrough since the first transplants three decades ago

Professor Steve Westaby

Initial trials involving more than 100 patients are being planned for the autumn at two London hospitals.

World renowned cardiac surgeon Professor Steve Westaby, who helped pioneer the revolutionary technique, said it had been thought that repairing heart damage was impossible.

But results from a long-term trial that began in Greece five years ago have shown that this is not the case.

Preliminary data from this trial showed the engineered stem cells, known as Heartcel, can reverse scarring by up to 79 per cent.

The data, presented at the European Society of Cell and Gene Therapy in Florence, showed an average of 40 per cent reduction in heart damage in those on the treatment.

Last month researchers finalised talks with European and US regulators to discuss the timetable for global trials next year involving 500 people.

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6 early signs of a heart attack

Professor Westaby, from the John Radcliffe Hospital, Oxford, said: I am very excited at the prospect of a trial which will hopefully lead to the availability of this stem cell treatment to thousands of patients annually in the UK.

Other scientists have tried in vain to repair damaged heart muscle using stem cells over the past few decades.

This is the first time scarring has been shown to be reversible. It could herald an end to transplants and lead to a treatment for heart failure within three to five years.

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Professor Westaby said: This would be the biggest breakthrough since the first transplants three decades ago.

Professor Westaby has been working on the technique for more than a decade and is carrying out the study with Professor Kim Fox, head of the National Heart and Lung Institute, at Imperial College London.

The implanted stem cells were created by medical outfit Celixir, co-founded by Nobel laureate Professor Martin Evans, the first scientist to culture mice embryonic stem cells in a laboratory.

Professor Westaby was inspired to work on the breakthrough in 1999 after a four-month-old baby girls heart healed itself after he carried out a major life-saving operation.

Kirsty Collier, from Swindon, was dying of a serious and rare heart defect. In a last ditch effort Professor Westaby cut away a third of her badly damaged heart.

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Surprisingly it began to beat. Fourteen years later a scan has shown that the heart had healed itself.

Now Kirsty, 18, has a normal one. Professor Westaby said: She was essentially dead and was only resurrected by what I regarded at the time as a completely bizarre operation.

The fact there was no sign of heart damage told me there were foetal stem cells in babies hearts that could remove scarring of heart muscle. That never happens in adults.

Its all down to the clues we got from Kirstys operation.

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Heart failure BREAKTHROUGH: Stem cells trial offers hope to millions - Express.co.uk

Cardiac Stem Cells Comments Off on Heart failure BREAKTHROUGH: Stem cells trial offers hope to millions – Express.co.uk | February 25th, 2017

Dr. Jeffrey Spees, an associate professor of medicine at the University of Vermonts College of Medicine, will present Rescue and Repair of Cardiac Tissue After Injury: Turning Star Trek into Sesame Street, on Wednesday, March 1, at the Town and Country Resort, 876 Mountain Road, Stowe. Doors open at 1 p.m. and the lecture begins promptly at 1:30 p.m. This is the eighth Osher Lifelong Learning Institute lecture of the winter series.

Spees earned his Ph.D. in physiological and molecular ecology at the University of California, Davis. At UVM he teaches courses in developmental neurobiology, human structure and function and stem cells and regenerative medicine.

Spees has directed the Stem Cell Core in UVMs Department of Medicine and was one of the founding members of the New England Stem Cell Consortium. Spees and his colleagues have developed and applied for a patent for a therapy using a protein complex that is highly protective and keeps cells alive. He will discuss this research and its role in repairing cardiac tissue to improve cardiac function after a heart attack.

Vermont musicologist Joel Najman will present the final lecture of the winter series, Rock n Roll: From Elvis to Lady Gaga, on Wednesday, March 8.

The lecture is $5 and refreshments will be served after the talk. To check on weather cancellations, listen to WDEV 550 AM or WLVB 93.9 FM or call Town and Country Resort at 253-7595. To sponsor a lecture, a series or refreshments, call Dick Johannesen, 253-8475. Information: learn.uvm.edu/osher.

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Cardiac injury, recovery is topic of Osher lecture - Stowe Today

Cardiac Stem Cells Comments Off on Cardiac injury, recovery is topic of Osher lecture – Stowe Today | February 25th, 2017

Cells within our bodies divide and change over time, with thousands of chemical reactions occurring within each cell daily. This makes it difficult for scientists to understand whats happening inside. New nanostraws offer a non-disruptive way to find out.

A problem with the current method of cell sampling, called lysing, is that it ruptures the cell. Once the cell is destroyed, it cant be sampled from again. This new sampling system relies on tiny tubes 600 times smaller than a strand of hair that allow researchers to sample a single cell at a time. The nanostraws penetrate a cells outer membrane, without damaging it, and draw out proteins and genetic material from the cells salty interior.

Its like a blood draw for the cell, says Nicholas Melosh, an associate professor of materials science and engineering at Stanford University and senior author of a paper describing the work in the Proceedings of the National Academy of Sciences.

The nanostraw sampling technique, according to Melosh, will significantly impact our understanding of cell development and could lead to much safer and effective medical therapies because the technique allows for long term, non-destructive monitoring.

What we hope to do, using this technology, is to watch as these cells change over time and be able to infer how different environmental conditions and chemical cocktails influence their developmentto help optimize the therapy process, Melosh says.

If researchers can fully understand how a cell works, then they can develop treatments that will address those processes directly. For example, in the case of stem cells, researchers are uncovering ways of growing entire, patient-specific organs. The trick is, scientists dont really know how stem cells develop.

For stem cells, we know that they can turn into many other cell types, but we do not know the evolutionhow do they go from stem cells to, say, cardiac cells? There is always a mystery. This sampling technique will give us a clearer idea of how its done, says Yuhong Cao, a graduate student and first author on the paper.

The sampling technique could also inform cancer treatments and answer questions about why some cancer cells are resistant to chemotherapy while others are not.

With chemotherapy, there are always cells that are resistant, says Cao. If we can follow the intercellular mechanism of the surviving cells, we can know, genetically, its response to the drug.

The sampling platform on which the nanostraws are grown is tinyabout the size of a gumball. Its called the Nanostraw Extraction (NEX) sampling system, and it was designed to mimic biology itself.

In our bodies, cells are connected by a system of gates through which they send each other nutrients and molecules, like rooms in a house connected by doorways. These intercellular gates, called gap junctions, are what inspired Melosh six years ago, when he was trying to determine a non-destructive way of delivering substances, like DNA or medicines, inside cells. The new NEX sampling system is the reverse, observing whats happening within rather than delivering something new.

Its a super exciting time for nanotechnology, Melosh says. Were really getting to a scale where what we can make controllably is the same size as biological systems.

Building the NEX sampling system took years to perfect. Not only did Melosh and his team need to ensure cell sampling with this method was possible, they needed to see that the samples were actually a reliable measure of the cell content, and that samples, when taken over time, remained consistent.

When the team compared their cell samples from the NEX with cell samples taken by breaking the cells open, they found that 90 percent of the samples were congruous. Meloshs team also found that when they sampled from a group of cells day after day, certain molecules that should be present at constant levels remained the same, indicating that their sampling accurately reflected the cells interior.

With help from collaborators Sergiu P. Pasca, assistant professor of psychiatry and behavioral sciences, and Joseph Wu, professor of radiology, Melosh and coworkers tested the NEX sampling method not only with generic cell lines, but also with human heart tissue and brain cells grown from stem cells. In each case, the nanostraw sampling reflected the same cellular contents as lysing the cells.

The goal of developing this technology, according to Melosh, was to make an impact in medical biology by providing a platform that any lab could build. Only a few labs across the globe, so far, are employing nanostraws in cellular research, but Melosh expects that number to grow dramatically.

We want as many people to use this technology as possible, he says.

Funding for the work came from the National Institute of Standards and Technology, the Knut and Alice Wallenberg Foundation, the National Institutes of Health, Stanford Bio-X, the Progenitor Cell Biology Consortium, the National Institute of Mental Health, an MQ Fellow award, the Donald E. and Delia B. Baxter Foundation, and the Child Health Research Institute.

Source: Jackie Flynn forStanford University

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Nanostraw doesn't destroy cells as it samples their guts - Futurity: Research News

Cardiac Stem Cells Comments Off on Nanostraw doesn’t destroy cells as it samples their guts – Futurity: Research News | February 23rd, 2017

Tiny nanostraws may offer a glimpse into a cells contents without causing any damage to the cell.

The nanostraws were developed by researchers at Stanford University, who devised a method of sampling cell contents without disrupting its natural processes, which is a staple of current cell sampling methods.

The new method relies on tiny tubes 600 times smaller than a stand of hair that allow researchers to sample a single cell at a time. The nanostraws are able to penetrate a cells outer membrane without damaging it and draw out proteins and genetic material from the cells salty interior.

It's like a blood draw for the cell, Nicholas Melosh, an associate professor of materials science and engineering and senior author on a paper, said in a statement.

According to Melosh, this technique will significantly impact the understanding of cell development and could yield much safer and effective medical therapies because it allows for long term, non-destructive monitoring.

What we hope to do, using this technology, is to watch as these cells change over time and be able to infer how different environmental conditions and 'chemical cocktails' influence their developmentto help optimize the therapy process, he said.

If researchers gain a better grasp on how a cell works they can address those processes directly.

For stem cells, we know that they can turn into many other cell types but we do not know the evolutionhow do they go from stem cells to, say, cardiac cells? Yuhong Cao, a graduate student and first author on the paper, said in a statement. This sampling technique will give us a clearer idea of how it's done.

A benefit of the sampling method is it could inform cancer treatments and answer questions about why some cancer cells are resistant to chemotherapy while others are not.

With chemotherapy, there are always cells that are resistant, Cao said. If we can follow the intercellular mechanism of the surviving cells, we can know, genetically, its response to the drug.

The nanostraws are grown in a small sampling platform designed to mimic biology called the Nanostraw Extraction (NEX) sampling system.

Cells divide and change over time, with thousands of chemical reactions occurring within each cell every day, which makes it difficult to truly understand the inner workings of cells.

Currently, scientists use a method of cell sampling called lysing, which ruptures the cell. However, once a cell is destroyed it cannot be sampled from again.

Cells in our bodies are connected by a system of gates through which they send each other nutrients and molecules.

Melosh was inspired to develop the new system when he observed the intercellular gates after he was trying to determine a non-destructive way of delivering substances, including DNA or medicines, inside cells.

The new sampling system is the reverse of that process, as scientists are able to observe whats happening within a cell.

When the research team compared their cells samples from the NEX with cell samples taken by breaking the cells open, they found that 95 percent of the samples were congruous.

The team also found that when they sampled from a group of cells day after day, certain molecules that should be present at constant levels remained the same, which indicated that their sampling accurately reflected the cells interior.

The team not only sampled generic cell lines but also with human heart tissue and brain cells grown from stem cells and in each case the nanostraw sampling reflected the same cellular contents as lysing the cells.

The study was published in the Proceedings of the National Academy of Sciences of the United States of America.

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Nanostraws Sample Cells Without Damage - R & D Magazine

Cardiac Stem Cells Comments Off on Nanostraws Sample Cells Without Damage – R & D Magazine | February 23rd, 2017

The decade-old excitement surrounding the potential for autologous cell therapy to treat cardiovascular disease may have fizzled into futility for many clinicians. But according to a new European consensus document, its possible this technology will yet find a way into future practice .

One of the problems the field has faced is that people got super excited 10 years ago because it was overhyped, and essentially . . . it led to the expectation that every time we presented [something] at clinical meetings, the field would move forward. And of course that wasnt the case, chair of the European Society of Cardiology stem cell task force and lead author Anthony Mathur, MD (St Bartholomews Hospital West Smithfield, London, England), told TCTMD.

The reason why I think people have run out of steam on this one is that theyve shared the 10-year journey with us. Anthony Mathur

Mathur contrasted the story of cell therapy to that of drug or device development, which is usually kept private until promising phase III data are available to support its routine use. What we've done is weve exposed the clinical and scientific community to a journey that in pharma we just wouldn't see as clinicians, he said. The reason why I think people have run out of steam on this one is that theyve shared the 10-year journey with us.

The document, which appeared online February 15, 2017, ahead of print in the European Heart Journal, was written as an update to a slightly more optimistic statement from the same task force published in 2006.

Of all of the recommendations that the original document made, very few have borne fruit. For example, the task force suggested the completion of a randomized trial for the use of autologous stem cells to treat acute MI patients presenting after more than 12 hours or who fail to respond to therapy. A trial such as this has not been undertaken and likely wont happen, given that primary angioplasty practice in Europe and the United States has revolutionized the treatment of acute MI and drastically lowered mortality, Mathur said. Any new method of treating acute MI will find it really tough to demonstrate an improvement unless its a complete game changer.

Since these patients may well develop heart failure, for which chronic cell therapy strategies are under development, research efforts should refocus there for now, the task force writes.

However, they stand by one 2006 recommendation for a randomized trial of autologous cells in acute MI patients presenting within 12 hours and treated with immediate revascularization. The ongoing phase III BAMI trial, undertaken by members of this task force including Mathur, will study just that but results are not expected for several years. Once these results are available, it will be time to either draw a line under it or ask for regulatory approval, but it's sort of pointless to keep rehashing the whole thing and going back asking the same question, Mathur said.

Careful But Hopeful

Looking back, Mathur said that the trajectory of cell therapy in cardiology has taught him to be self-critical and very careful about what we say, and to understand that it is okay to stop doing certain things that were once thought to be appropriate. Also, because those involved in translational research lack the tools that give us an evidence or an idea of the signal that we should expect in larger clinical trials, [a] lot of what weve come across is potentially unexpected. Unfortunately, it also means . . . weve probably disregarded areas of research based on the signals we haven't seen in smaller studies simply because, in a way, the tools we have arent sensitive enough to pick it up, he said.

If there is any biological signal found in a phase II study, Mathur stressed the importance of trying to complete a phase III study in order to unlock these unexpected kernels.

Far from being defeated, he said he is hopeful that cell therapy will pan out in some way for cardiac patients. Whether cell therapy worked or not, it's all about the amazing stories and how it changed people's lives seemingly for the better. So thats something thats difficult to drop, Mathur said. We have seen a signal for patients in heart failure in which there seems to be some sort of benefit. And some might say its purely psychological. Fine, but these people who were told there was nothing else that could be done got better.

The rest is here:
Less Acute MI, More HF: European Task Force Shifts Support for 'Overhyped' Cell Therapy Research - TCTMD

Cardiac Stem Cells Comments Off on Less Acute MI, More HF: European Task Force Shifts Support for ‘Overhyped’ Cell Therapy Research – TCTMD | February 23rd, 2017

Science Daily

Researchers implicate suspect in heart disease linked to diabetes ... Science Daily Scientists have struggled to trace the specific biology behind diabetes-associated heart disease risk or find ways to intervene. Now, researchers have hunted ... and more »

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Researchers implicate suspect in heart disease linked to diabetes ... - Science Daily

Cardiac Stem Cells Comments Off on Researchers implicate suspect in heart disease linked to diabetes … – Science Daily | February 22nd, 2017

February 21, 2017 by Mark Derewicz Top Row: Heart arteries in normal mice, diabetic mice, and normal mice with deleted IRS-1 gene. Bottom row: when artery is wounded, diabetic mice with less IRS-1 and normal mice with deleted IRS-1 gene show much greater blockage due to over-proliferation of smooth muscle cells. Credit: Clemmons Lab, UNC School of Medicine

People with diabetes are at high risk of developing heart disease. Despite knowing this, scientists have struggled to trace the specific biology behind that risk or find ways to intervene. Now, UNC School of Medicine researchers have hunted down a possible culprit - a protein called IRS-1, which is crucial for the smooth muscle cells that make up veins and arteries.

According to a study published in the Journal of Biological Chemistry, too little of IRS-1 causes cells to revert to a "dedifferentiated" or stem-cell like state, and this may contribute to the buildup of plaque in the heart's arteries, a condition known as atherosclerosis, which increases the risk of heart attack, stroke, and other forms of heart disease.

"When diabetes is poorly managed, your blood sugar goes up and the amount of this protein goes down, so the cells become subject to abnormal proliferation," said senior author David R. Clemmons, MD, Sarah Graham Kenan Professor of Medicine at the UNC School of Medicine. "We need to conduct more studies, but we think this cell pathway may have significant implications for how high blood glucose leads to atherosclerosis in humans."

The research could bring scientists one step closer to finding drugs to help stave off heart disease in people with diabetes, who are twice as likely to have heart disease or experience a stroke, as compared to people without diabetes. People with diabetes also tend to experience major cardiac events at a younger age.

The study focused on the cells that form the walls of veins and arteries, known as vascular smooth muscle cells. The main function of these cells is to contract whenever the heart beats, helping to push oxygen-rich blood to the body's tissues. When plaque builds up along the arterial walls, these cells gradually lose their ability to contract.

In their previous work, Clemmons and colleagues discovered that diabetes can trigger an abnormal cell signaling pathway that causes vascular smooth muscle cells to proliferate, which contributes to atherosclerosis. But their attempts to correct the abnormal signaling pathway didn't seem to completely solve the problem, leading them to suspect another factor.

In the new study, the team found that IRS-1 acts as an inhibitor of the abnormal signaling pathway thereby keeping the vascular smooth muscle cells differentiated, or specialized. In the absence of IRS-1, the cells revert to a stem-cell like state, which in turn activates the abnormal signaling pathway and promotes cell proliferation.

In people with diabetes, the presence of IRS-1 is strongly influenced by how well - or how poorly - blood sugar is kept in check. Previous studies have shown that patients who frequently or consistently have high blood sugar show dramatic reductions in IRS-1. The new study is the first to link this reduction with a predisposition for heart disease.

"The study suggests that you can't just inhibit the abnormal signaling, which we've already figured out how to do," Clemmons said. "Our work suggests you probably have to restore the normal signaling pathway, at least to some extent, in order to completely restore the cells to normal cell health, differentiation, and functioning."

As a next step, the Clemmons lab will look for things that might stimulate the synthesis of this protein even in the presence of high blood glucose.

To prove that IRS-1 acts as a brake on the abnormal signaling pathway that leads to cell proliferation, the team conducted experiments in three different types of mice: healthy mice, diabetic mice, and nondiabetic mice that were genetically engineered to produce no IRS-1. The scientists made a small incision in the blood vessels of the animals and then watched to see how the vascular smooth muscle cells reacted. In healthy mice, the incision stimulated wound healing but little cellular proliferation. In both the diabetic animals and the nondiabetic IRS-1 deficient animals, the researchers observed a marked increase in abnormal cellular proliferation.

The findings suggest that it may be possible to counteract the deleterious effects of high blood sugar on atherosclerosis by developing drugs that boost IRS-1.

Clemmons said the activities of IRS-1 might also play a role in other diabetes complications, such as eye and kidney disease. The researchers plan to study those potential links.

Explore further: Researchers use stem cells to regenerate the external layer of a human heart

A process using human stem cells can generate the cells that cover the external surface of a human heartepicardium cellsaccording to a multidisciplinary team of researchers.

After a heart attack, or myocardial infarction, a patient's long-term prognosis depends on the ability of the heart tissue to heal and remodel. Immune system activation and inflammatory responses that occur in the aftermath ...

According to the American Heart Association, approximately 2,200 Americans die each day from heart attacks, strokes and other cardiovascular diseases. The most common cause is blocked blood vessels that can no longer supply ...

People with any form of diabetes are at greater risk of developing cardiovascular conditions than people without the disease. Moreover, if they undergo an operation to open up a clogged artery by inserting a "stent" surgical ...

Patients with diabetes and metabolic syndrome are at increased risk of atherosclerosis and subsequent heart disease. It is not fully understood why atherosclerosis is increased with diabetes, but it has been proposed that ...

Scientists have implicated a type of stem cell in the calcification of blood vessels that is common in patients with chronic kidney disease. The research will guide future studies into ways to block minerals from building ...

People with diabetes are at high risk of developing heart disease. Despite knowing this, scientists have struggled to trace the specific biology behind that risk or find ways to intervene. Now, UNC School of Medicine researchers ...

A long-term study by Monash University researchers - the first of its kind - has found that gastric band surgery has significant benefits for moderately overweight people with type 2 diabetes. Previous studies have focused ...

Blood sugar triggers the secretion of insulin from cells in the pancreas, a process that is impaired in diabetes. A team of Yale researchers have identified a mechanism at the membranes of these pancreatic cells that controls ...

Alpha cells in the pancreas can be induced in living mice to quickly and efficiently become insulin-producing beta cells when the expression of just two genes is blocked, according to a study led by researchers at the Stanford ...

A new study by researchers at King's College London has found that patients with diabetes suffering from the early stages of kidney disease have a deficiency of the protective 'anti-ageing' hormone, Klotho.

Why do some people get Type 2 diabetes, while others who live the same lifestyle never do?

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I was diagnosed with type 2 Diabetes and put on Metformin on June 26th, 2016. I started the ADA diet and followed it 100% for a few weeks and could not get my blood sugar to go below 140. Finally i began to panic and called my doctor, he told me to get used to it. He said I would be on metformin my whole life and eventually insulin. At that point i knew something wasn't right and began to do a lot of research. On August 13th I found Lisa's diabetes story (google " HOW EVER I FREED MYSELF FROM THE DIABETES " ) I read that article from end to end because everything the writer was saying made absolute sense. I started the diet that day and the next morning my blood sugar was down to 100 and now i have a fasting blood sugar between Mid 70's and the 80's. My doctor took me off the metformin after just three week of being on this lifestyle change. I have lost over 30 pounds and 6+ inches around my waist in a month

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Researchers implicate suspect in heart disease linked to diabetes - Medical Xpress

Cardiac Stem Cells Comments Off on Researchers implicate suspect in heart disease linked to diabetes – Medical Xpress | February 21st, 2017

Cells within our bodies divide and change over time, with thousands of chemical reactions occurring within each cell daily. This makes it difficult for scientists to understand whats happening inside. Now, tiny nanostraws developed by Stanford researchers offer a method of sampling cell contents without disrupting its natural processes.

Nicholas Melosh, associate professor of materials science and engineering, developed a new, non-destructive system for sampling cells with nanoscale straws. The system could help uncover mysteries about how cells function. (Image credit: L.A. Cicero)

A problem with the current method of cell sampling, called lysing, is that it ruptures the cell. Once the cell is destroyed, it cant be sampled from again. This new sampling system relies on tiny tubes 600 times smaller than a strand of hair that allow researchers to sample a single cell at a time. The nanostraws penetrate a cells outer membrane, without damaging it, and draw out proteins and genetic material from the cells salty interior.

Its like a blood draw for the cell, said Nicholas Melosh, an associate professor of materials science and engineering and senior author on a paper describing the work published recently in Proceedings of the National Academy of Sciences.

The nanostraw sampling technique, according to Melosh, will significantly impact our understanding of cell development and could lead to much safer and effective medical therapies because the technique allows for long term, non-destructive monitoring.

What we hope to do, using this technology, is to watch as these cells change over time and be able to infer how different environmental conditions and chemical cocktails influence their development to help optimize the therapy process, Melosh said.

If researchers can fully understand how a cell works, then they can develop treatments that will address those processes directly. For example, in the case of stem cells, researchers are uncovering ways of growing entire, patient-specific organs. The trick is, scientists dont really know how stem cells develop.

For stem cells, we know that they can turn into many other cell types, but we do not know the evolution how do they go from stem cells to, say, cardiac cells? There is always a mystery. This sampling technique will give us a clearer idea of how its done, said Yuhong Cao, a graduate student and first author on the paper.

The sampling technique could also inform cancer treatments and answer questions about why some cancer cells are resistant to chemotherapy while others are not.

With chemotherapy, there are always cells that are resistant, said Cao. If we can follow the intercellular mechanism of the surviving cells, we can know, genetically, its response to the drug.

The sampling platform on which the nanostraws are grown is tiny about the size of a gumball. Its called the Nanostraw Extraction (NEX) sampling system, and it was designed to mimic biology itself.

In our bodies, cells are connected by a system of gates through which they send each other nutrients and molecules, like rooms in a house connected by doorways. These intercellular gates, called gap junctions, are what inspired Melosh six years ago, when he was trying to determine a non-destructive way of delivering substances, like DNA or medicines, inside cells. The new NEX sampling system is the reverse, observing whats happening within rather than delivering something new.

Its a super exciting time for nanotechnology, Melosh said. Were really getting to a scale where what we can make controllably is the same size as biological systems.

Building the NEX sampling system took years to perfect. Not only did Melosh and his team need to ensure cell sampling with this method was possible, they needed to see that the samples were actually a reliable measure of the cell content, and that samples, when taken over time, remained consistent.

When the team compared their cell samples from the NEX with cell samples taken by breaking the cells open, they found that 90 percent of the samples were congruous. Meloshs team also found that when they sampled from a group of cells day after day, certain molecules that should be present at constant levels remained the same, indicating that their sampling accurately reflected the cells interior.

With help from collaborators Sergiu P. Pasca, assistant professor of psychiatry and behavioral sciences, and Joseph Wu, professor of radiology, Melosh and co-workers tested the NEX sampling method not only with generic cell lines, but also with human heart tissue and brain cells grown from stem cells. In each case, the nanostraw sampling reflected the same cellular contents as lysing the cells.

The goal of developing this technology, according to Melosh, was to make an impact in medical biology by providing a platform that any lab could build. Only a few labs across the globe, so far, are employing nanostraws in cellular research, but Melosh expects that number to grow dramatically.

We want as many people to use this technology as possible, he said. Were trying to help advance science and technology to benefit mankind.

Melosh is also a professor in the photon science directorate at SLAC National Accelerator Laboratory, a member of Stanford Bio-X, the Child Health Research Institute, the Stanford Neurosciences Institute, Stanford ChEM-H and the Precourt Institute for Energy. Wu is also the Simon H. Stertzer, MD, Professor; he is director of the Stanford Cardiovascular Institute and a member of Stanford Bio-X, the Child Health Research Institute, Stanford ChEM-H and the Stanford Cancer Institute. Pasca is also a member of Stanford Bio-X, the Child Health Research Institute, the Stanford Neurosciences Institute and Stanford ChEM-H.

The work was funded by the National Institute of Standards and Technology, the Knut and Alice Wallenberg Foundation, the National Institutes of Health, Stanford Bio-X, the Progenitor Cell Biology Consortium, the National Institute of Mental Health, an MQ Fellow award, the Donald E. and Delia B. Baxter Foundation and the Child Health Research Institute.

Link:
Stanford-developed nanostraws sample a cell's contents without damage - Stanford University News

Cardiac Stem Cells Comments Off on Stanford-developed nanostraws sample a cell’s contents without damage – Stanford University News | February 21st, 2017

SOUTH SAN FRANCISCO, CA--(Marketwired - February 13, 2017) - VistaGen Therapeutics Inc. (VTGN), a clinical-stage biopharmaceutical company focused on developing new generation medicines for depression and other central nervous system (CNS) disorders, today reported financial results for the third quarter of fiscal 2017 ended December 31, 2016.

The Company also provided a corporate update, including anticipated milestones for AV-101, its new generation, orally available CNS prodrug candidate in Phase 2 development, initially for the adjunctive treatment of major depressive disorder (MDD) in patients with an inadequate response to standard antidepressant therapies approved by the U.S. Food and Drug Administration (FDA).

"We are excited about our progress during the last quarter, with several key advances related to our MDD-focused programs for AV-101, as well as potential regenerative medicine and drug rescue applications of our cardiac stem cell technology. Following productive discussions with the FDA last quarter, our team and key advisors have been working diligently to complete the diverse regulatory and technical activities necessary to support the planned launch of our Phase 2b study of AV-101 next quarter, a study we believe has game-changing potential for the millions of patients who battle MDD every day with inadequate therapies," commented Shawn Singh, Chief Executive Officer of VistaGen. "Also, our recent sublicense agreement with BlueRock Therapeutics was an important advance in our cardiac stem cell program while we remain primarily focused on our Phase 2 programs for AV-101. With potentially catalytic milestones in the coming quarters, we believe we are poised to unlock significant value for our shareholders throughout 2017," added Mr. Singh.

Recent Corporate Highlights:

The U.S. National Institute of Mental Health (NIMH) is currently conducting and fully funding a 20 to 25-patient Phase 2a study of AV-101 as a monotherapy for treatment-resistant MDD under VistaGen's Cooperative Research and Development Agreement (CRADA) with the NIMH (Phase 2a Study). Dr. Carlos Zarate Jr., Chief, Section on the Neurobiology and Treatment of Mood Disorders and Chief of Experimental Therapeutics and Pathophysiology Branch at the NIMH and a leading clinical expert on the use of ketamine for treatment-resistant MDD, is the Principal Investigator of the Phase 2a Study. Following recent guidance from the NIMH, the Company currently anticipates that the NIMH will complete the Phase 2a Study by the end of 2017.

VistaGen is preparing to launch a 280-patient, multi-center, double-blind, placebo controlled Phase 2b efficacy and safety study evaluating AV-101 as a new generation adjunctive treatment for MDD patients with an inadequate response to standard, FDA-approved antidepressant therapies. The Company currently anticipates commencing patient enrollment in the Phase 2b Study in the second quarter of 2017. Dr. Maurizio Fava of Harvard University Medical School will serve as the Principal Investigator of VistaGen's AV-101 Phase 2b Study. Topline clinical results from the Phase 2b Study are currently anticipated by the end of 2018.

Dr. Mark Smith, Chief Medical Officer of VistaGen, commented, "We look forward to starting patient enrollment in our Phase 2b study of AV-101 as an adjunctive therapy in the treatment of MDD. We believe we have significantly de-risked this Phase 2b study with a clinical trial methodology that is designed to overcome the challenge of placebo effects in psychiatric clinical trials. Based on the study protocol we have designed in collaboration with key opinion leaders in depression and neuroscience, including our Principal Investigator, Dr. Fava, we expect that achieving a successful outcome of our Phase 2b study will be integral in realizing AV-101's potential to displace atypical antipsychotics and non-drug interventions in the current depression treatment paradigm, representing a much needed treatment solution for physicians and patients, as well as an enormous opportunity for VistaGen."

Expected Near-Term Milestones:

"The NIMH recently updated us on their timelines for the completion of the Phase 2a study of AV-101 as a monotherapy for MDD. The Phase 2a study protocol requires considerable time and dedication from both the study participants and the multi-disciplinary NIMH teams involved. Patient enrollment for the Phase 2a study remains ongoing and we currently anticipate the NIMH's completion of the study by the end of 2017. Our top priority is to execute our plans for our Phase 2b study of AV-101 as a new generation adjunctive treatment of MDD, and we remain on track to launch that important study in the second quarter. As part of our Phase 2 program, this Phase 2b study has been specifically designed to achieve important outcomes that will be key to advancing AV-101 into a pivotal program in MDD and more broadly beyond MDD, as we continue to advance our global commercialization strategy. We are confident that our Phase 2 program is a major step forward in positioning AV-101 as a potentially transformative adjunctive treatment of MDD and other CNS disorders," concluded Mr. Singh.

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Summary of Financial Results for the Third Quarter of Fiscal 2017 Ended December 31, 2016

Revenue

The Company recognized $1.25 million in sublicense revenue pursuant to its cardiac stem cell technology sublicense agreement with BlueRock Therapeutics, a next generation regenerative medicine company established by Bayer AG and Versant Ventures, in the third fiscal quarter ended December 31, 2016.

Research and Development Expenses

Research and development expense totaled $1.61 million for the third fiscal quarter ended December 31, 2016, compared to $806,300 for the quarter ended December 31, 2015, reflecting increasing focus on nonclinical and clinical development of AV-101 and preparations for launch of the AV-101 Phase 2b Study in the second quarter of 2017.

General and Administrative Expenses

General and administrative expense increased to $2.3 million in the third fiscal quarter ended December 31, 2016, from $1.3 million for the same period in the prior year. The increase in G&A expense is the result of increased noncash stock compensation expense attributable to option and warrant grants in the period to employees, independent members of the Company's Board of Directors and consultants and other noncash expense related to grants of equity securities in payment of certain professional services, and a combination of corporate expenses, including investor relations and corporate development initiatives.

Net Loss

For the third fiscal quarter ended December 31, 2016, the Company reported a net loss of approximately $2.6 million, or a net loss attributable to common stockholders of $0.34 per common share, compared to a net loss of approximately $2.1 million, or a net loss attributable to common stockholders of $1.95 per common share for the same period in the prior year.

Cash and Cash Equivalents

As of December 31, 2016, the Company had approximately $5.6 million of cash, cash equivalents and short term receivables, including a $1.25 million short term sublicense fee receivable from BlueRock Therapeutics pursuant to the Company's December 2016 technology sublicense agreement with BlueRock Therapeutics. In January 2017, the Company received the $1.25 million sublicense fee payment from BlueRock Therapeutics and currently believes it has sufficient financial resources to fund its expected operations at least through the first half of 2017, including preparation for and launch of its planned AV-101 Phase 2b Study in MDD.

About VistaGen

VistaGen Therapeutics, Inc. (VTGN), is a clinical-stage biopharmaceutical company focused on developing new generation medicines for depression and other central nervous system (CNS) disorders. VistaGen's lead CNS product candidate, AV-101, is a new generation oral antidepressant drug candidate in Phase 2 development. AV-101's mechanism of action is fundamentally differentiated from all FDA-approved antidepressants and atypical antipsychotics used adjunctively to treat MDD, with potential to drive a paradigm shift towards a new generation of safer and faster-acting antidepressants. AV-101 is currently being evaluated by the U.S. National Institute of Mental Health (NIMH) in a Phase 2a monotherapy study in MDD being fully funded by the NIMH and conducted by Dr. Carlos Zarate Jr., Chief, Section on the Neurobiology and Treatment of Mood Disorders and Chief of Experimental Therapeutics and Pathophysiology Branch at the NIMH. VistaGen is preparing to launch a 280-patient Phase 2b study of AV-101 as an adjunctive treatment for MDD patients with inadequate response to standard, FDA-approved antidepressant therapies. Dr. Maurizio Fava of Harvard University will be the Principal Investigator of the Phase 2b study. AV-101 may also have the potential to treat multiple CNS disorders and neurodegenerative diseases in addition to MDD, including chronic neuropathic pain, epilepsy, Parkinson's disease and Huntington's disease, where modulation of the NMDAR, AMPA pathway and/or key active metabolites of AV-101 may achieve therapeutic benefit.

VistaStem Therapeutics is VistaGen's wholly owned subsidiary focused on applying human pluripotent stem cell (hPSC) technology, internally and with third-party collaborators, to discover, rescue, develop and commercialize proprietary new chemical entities (NCEs), including small molecule NCEs with regenerative potential, for CNS and other diseases, and cellular therapies involving stem cell-derived blood, cartilage, heart and liver cells. In December 2016, VistaGen exclusively sublicensed to BlueRock Therapeutics LP, a next generation regenerative medicine company established by Bayer AG and Versant Ventures, rights to certain proprietary technologies relating to the production of cardiac stem cells for the treatment of heart disease.

For more information, please visit http://www.vistagen.com and connect with VistaGen on Twitter, LinkedIn and Facebook.

Forward-Looking Statements

The statements in this press release that are not historical facts may constitute forward-looking statements that are based on current expectations and are subject to risks and uncertainties that could cause actual future results to differ materially from those expressed or implied by such statements. Those risks and uncertainties include, but are not limited to, risks related to the successful launch, continuation and results of the NIMH's Phase 2a (monotherapy) and/or the Company's planned Phase 2b (adjunctive therapy) clinical studies of AV-101 in MDD, and other CNS diseases and disorders, protection of its intellectual property, and the availability of substantial additional capital to support its operations, including the development activities described above. These and other risks and uncertainties are identified and described in more detail in VistaGen's filings with the Securities and Exchange Commission (SEC). These filings are available on the SEC's website at http://www.sec.gov. VistaGen undertakes no obligation to publicly update or revise any forward-looking statements.

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VistaGen Therapeutics Reports Fiscal Third Quarter 2017 Financial ... - Yahoo Finance

Cardiac Stem Cells Comments Off on VistaGen Therapeutics Reports Fiscal Third Quarter 2017 Financial … – Yahoo Finance | February 18th, 2017

OSAKA, Japan & LEUVEN, Belgium--(BUSINESS WIRE)--Takeda Pharmaceutical Company Limited (TSE:4502) (Takeda) and TiGenix NV (Euronext Brussels and Nasdaq:TIG) (TiGenix) today announced new data from the Phase 3 ADMIRE-CD clinical trial, which indicated that investigational compound Cx601, a suspension of allogeneic expanded adipose-derived stem cells (eASC), maintained long-term remission of treatment refractory complex perianal fistulas in patients with Crohns disease over 52 weeks.1 Results were presented at the 12th Congress of the European Crohns and Colitis Organisation (ECCO).

The ADMIRE-CD trial is a randomized, double-blind, controlled, Phase 3 trial, designed to investigate the efficacy and safety of the investigational compound Cx601 for the treatment of complex perianal fistulas in patients with Crohns disease.2 Patients were randomized to a single administration of Cx601 cells or placebo (control), both added to standard of care.1 A significantly greater proportion of patients in the Cx601 group versus the control group achieved clinical and radiological combined remission* (56.3% and 38.6%; p=0.010), and clinical remission (59.2% and 41.6%; p=0.013) at week 52 in the modified intention-to-treat population (mITT).1 Of those mITT patients who had shown combined remission at week 24, a greater number in the Cx601 group versus the control group reported no relapse at week 52 (75.0% and 55.9%).1 The rates and types of treatment related adverse events (non-serious and serious) and discontinuations due to adverse events were indicated to be similar in both groups (Cx601: 20.4%; control: 26.5%).1

Crohns disease is a chronic inflammatory disease of the gastrointestinal tract, which is thought to affect up to 1.6 million people in Europe.3 Complex perianal fistulas are a complication for people living with Crohns disease and there are limited treatment options. Recognizing the rare and debilitating nature of the disorder, and lack of treatment options, in 2009 the European Commission granted Cx601 orphan designation for the treatment of anal fistula. In March 2016, TiGenix announced that it submitted the Marketing Authorization Application (MAA) to the European Medicines Agency (EMA) for Cx601, and a decision by the EMA is expected in 2017. Additionally, in September 2016 orphan drug status was received from the Swiss Agency for Therapeutic Products (Swissmedic) regarding Cx601 for the rare disease complex perianal fistulas in Crohns disease.4

Perianal fistulizing Crohns disease is difficult to treat with currently available therapies and often leads to pain, swelling, infection and incontinence, said Dr. Asit Parikh, Head of Takedas Gastroenterology Therapeutic Area Unit. Existing therapies are limited and associated with complications and a high failure rate. Cx601 may offer patients an alternative treatment option.

These data highlight that the efficacy and safety of a single administration of Cx601 were maintained during one year of follow up, said Dr. Marie Paule Richard, Chief Medical Officer at TiGenix. It is important to also note that the definition of combined remission used in the ADMIRE-CD study, which includes both clinical and radiological assessment by MRI, is more stringent than the criteria commonly used in previous large scale, randomized clinical trials evaluating perianal fistulas in Crohns disease, based only on clinical assessment.

A global pivotal Phase 3 trial for U.S. registration with Cx601 for the treatment of complex perianal fistulas is expected to be initiated by TiGenix in 2017. In the U.S., TiGenix intends to apply for fast track designation from the U.S. Food and Drug Administration (FDA), which would facilitate and expedite the development and review process in the U.S.

Takedas Commitment to Gastroenterology

Takeda is a global leader in gastroenterology. With expertise spanning more than 25 years, the companys dedication to innovation continues to evolve and have a lasting impact. ENTYVIO (vedolizumab) demonstrates Takedas global capabilities and expansion into the specialty care market in gastroenterology and biologics. Designed and developed specifically to target the gastrointestinal (GI) tract, ENTYVIO was launched in 2014 for the treatment of adults with moderate to severe ulcerative colitis and Crohns disease. TAKECAB (vonoprazan fumarate) is Takeda's potassium-competitive acid blocker and was launched in Japan in 2015. Takeda also markets motility agent AMITIZA (lubiprostone), which originally launched in 2006 for the treatment of chronic idiopathic constipation, and received subsequent approval to treat irritable bowel syndrome with constipation and opioid-induced constipation. Preceding these notable launches, Takeda pioneered gastroenterological breakthroughs in proton pump inhibitors beginning in the 1990s with lansoprazole.Through specialized and strategic in-house development, external partnerships, in-licensing and acquisitions, Takeda currently has a number of promising early stage GI assets in development, and remains committed to delivering innovative, therapeutic options for patients with gastrointestinal and liver diseases.

About Takeda Pharmaceutical Company

Takeda Pharmaceutical Company Limited is a global, R&D-driven pharmaceutical company committed to bringing better health and a brighter future to patients by translating science into life-changing medicines. Takeda focuses its research efforts on oncology, gastroenterology and central nervous system therapeutic areas. It also has specific development programs in specialty cardiovascular diseases as well as late-stage candidates for vaccines. Takeda conducts R&D both internally and with partners to stay at the leading edge of innovation. New innovative products, especially in oncology and gastroenterology, as well as its presence in emerging markets, fuel the growth of Takeda. More than 30,000 Takeda employees are committed to improving quality of life for patients, working with our partners in health care in more than 70 countries. For more information, visit http://www.takeda.com/news.

About TiGenix

TiGenix NV (Euronext Brussels and Nasdaq: TIG) is an advanced biopharmaceutical company focused on developing and commercializing novel therapeutics from its proprietary platforms of allogeneic, or donor-derived, expanded stem cells. Our lead product candidate from the adipose-derived stem cell technology platform is Cx601, which is in registration with the EMA for the treatment of complex perianal fistulas in Crohns disease patients. Our adipose-derived stem cell product candidate Cx611 has completed a Phase I sepsis challenge trial and a Phase I/II trial in rheumatoid arthritis. Effective July 31, 2015, TiGenix acquired Coretherapix, whose lead cellular product candidate, AlloCSC-01, is currently in a Phase II clinical trial in acute myocardial infarction. In addition, the second product candidate from the cardiac stem cell-based platform acquired from Coretherapix, AlloCSC-02, is being developed in a chronic indication. On July 4, 2016, TiGenix entered into a licensing agreement with Takeda, a large pharmaceutical company active in gastroenterology, under which Takeda acquired the exclusive right to develop and commercialize Cx601 for complex perianal fistulas outside the United States. TiGenix is headquartered in Leuven (Belgium) and has operations in Madrid (Spain).

About Cx601

Cx601 is a suspension of allogeneic expanded adipose-derived stem cells (eASC) locally injected. Cx601 is an investigational compound being developed in Crohns disease for the treatment of complex perianal fistulas showing inadequate response to at least one conventional or biologic therapy including antibiotics, immunosuppressants, or anti-TNF agents. Crohns disease is a chronic inflammatory disease of the intestine and, as a complication of it, patients can suffer from complex perianal fistulas, for which there is currently no effective treatment. In 2009, the European Commission granted Cx601 orphan designation for the treatment of anal fistulas, recognizing the debilitating nature of the disease and the lack of treatment options. Cx601 has met the primary end-point in the Phase 3 ADMIRE-CD study, a randomized, double-blind, controlled trial run in Europe and Israel and designed to comply with the requirements laid down by the EMA. Madrid Network issued a soft loan to help finance this Phase 3 study, which was funded by the Secretary of State for Research, Development and Innovation (Ministry of Economy and Competitiveness) within the framework of the INNTEGRA plan. In this trial, patients were randomized to a single administration of Cx601 cells or placebo (control), both added to standard of care. The studys primary endpoint was combined remission, defined as clinical assessment at week 24 of closure of all treated external openings draining at baseline despite gentle finger compression, and absence of collections >2cm confirmed by MRI. In the ITT population (n=212), Cx601 achieved statistically significant superiority (p=0.024) on the primary endpoint with 50% combined remission at week 24 compared to 34% in the control arm. Efficacy results were robust and consistent across all statistical populations. Treatment emergent adverse events (non-serious and serious) and discontinuations due to adverse events were comparable between Cx601 and control arms. The 24-week results have been published by The Lancet, one of the most highly regarded and well known medical journals in the world. The Phase 3 study has completed a follow-up analysis at 52 weeks confirming its sustained efficacy and safety profile. Top line follow-up data showed that in the ITT population Cx601 achieved statistical superiority (p=0.012) with 54% combined remission at week 52 compared to 37% in the control arm. Long-term results also showed that, of patients with combined remission at week 24, a higher proportion of patients treated with Cx601 had no relapse at week 52 (75.0% vs. 55.9%). Based on the positive 24-weeks Phase 3 study results, TiGenix has submitted a Marketing Authorization Application to the EMA in early 2016. TiGenix is preparing to develop Cx601 in the U.S. after having reached an agreement with the FDA through a special protocol assessment procedure (SPA) in 2015. On July 4, 2016, TiGenix entered into a licensing agreement with Takeda, a pharmaceutical company leader in gastroenterology, whereby Takeda acquired an exclusive right to develop and commercialize Cx601 for complex perianal fistulas in Crohns patients outside of the U.S.

-Ends-

____________

* defined as clinical assessment of closure of all treated external openings draining at baseline, despite gentle finger compression, and absence of collections >2cm confirmed by MRI

References

1 Pans, J, Garca-Olmo, D, Van Assche, G, et al., Long-term efficacy and safety of Cx601, allogeneic expanded adipose-derived mesenchymal stem cells, for complex perianal fistulas in Crohns Disease: 52-week results of a phase III randomized controlled trial. ECCO 2017; Barcelona: Abstract OP009.

2 Clinicaltrials.gov. Adipose Derived Mesenchymal Stem Cells for Induction of Remission in Perianal Fistulizing Crohn's Disease (ADMIRE-CD). https://clinicaltrials.gov/ct2/show/NCT01541579?term=cx601&rank=2. Published February 2012. Accessed February 9, 2017.

3 Burisch, J, Jess, T, Martinato, M, et al., on behalf of ECCO EpiCom. The burden of inflammatory bowel disease in Europe. J Crohns Colitis. 2013; 7: 322-337.

4 Swissmedic. About us Collaboration National collaboration Patients and Users. Available at https://www.swissmedic.ch/ueber/01398/01400/03296/index.html?lang=en. Accessed February 9, 2017.

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Takeda and TiGenix Report New Data Highlighting Maintenance of ... - Business Wire (press release)

Cardiac Stem Cells Comments Off on Takeda and TiGenix Report New Data Highlighting Maintenance of … – Business Wire (press release) | February 17th, 2017

Seventy-year-old Peggy Agar has known since she was in her 40s that she and her 12 siblings might be at risk for familial cardiomyopathy, a genetic form of heart disease.

Her mother was diagnosed with it in 1987, and several of her brothers were also subsequently diagnosed with cardiomyopathy.

Given our family history, our family knew we had to be vigilant to keep our hearts as strong as possible, says Agar, who lives in Bloomfield.

But now thanks to the power of genetic testing at UConn Healths Pat and Jim Calhoun Cardiology Center, Agar and her family can determine which family members may be at risk.

Through a routine blood sample, Agars gene sequences were analyzed by Dr. Travis Hinson, a cardiovascular physician-scientist who is a new faculty member with a joint appointment at UConn Health and the Jackson Laboratory for Genomic Medicine.

Hinsons advanced genetic analysis revealed that Agar carries a gene mutation that causes dilated cardiomyopathy, a disease of the heart muscle that potentially leads to an enlarged, weakened heart and ultimately heart failure. He identified that Agar carries a mutation in the largest gene in the body called titin that leads to dilated cardiomyopathy in about 1 in 5 patients with a positive family history. In 2015, his laboratory published these findings in the journal Science, where he studied miniature beating human heart tissues engineered from stem cells from patients with conditions similar to Agars.

Hinson says knowing their genetic predisposition allows patients and families to understand why heart disease may continue to be prevalent generation after generation in their family.

If you carry the cardiomyopathy gene, you have a 50 percent chance of passing it to your offspring, says Hinson. Now with the power of genetic testing, we can tell each family member definitely early in their life whether they carry the cardiomyopathy genetic mutation, and intervene early to try to prevent any symptoms of the disease before they occur.

Agar says the genetic test results will arm her familys younger and future generations with important knowledge.

Now our family can better safeguard ourselves and younger generations at an early age to take extra precautions when it comes to our heart health, she says. Because of the way this myopathy develops in our family, we have learned that it is very important when we seek medical care that the physicians we see are aware of this family history.

Another positive aspect of the testing is that family members who are found not to have the gene no longer need to worry about passing the gene on to their children.

Agar has received comprehensive treatment from a team of physicians at UConn Healths Calhoun Cardiology Center, including cardiologist Dr. Jason Ryan and electrophysiologist Dr. Christopher Pickett. Since she was first diagnosed with cardiomyopathy in 2009, she has been treated for its complications. These include atrial fibrillation, the most common form of arrhythmia, and ventricular tachycardia, life-threatening and chaotic heart beats that can cause premature or sudden death. To protect her heart against dangerous arrhythmias, Agar takes daily medication; has received cardioversions (which convert an arrhythmia to a normal rhythm) and an ablation procedure (the destruction of tinyparts of heart tissue with radio frequency waves that are triggering arrhythmia); and has an implantable cardio-defibrillator.

As a result of the personalized team approach among the cardiologists who care for her at the Calhoun Cardiology Center, Agars heart function has been nearly normalized. She is grateful to the entire team.

Ive been fortunate, she says. UConns cardiac health team and their staff have been very supportive. They are truly experts in their field and treat me in a very professional and personal manner. They welcome questions and listen to my concerns. They convey the feeling that they truly care about my well-being.

Cardiomyopathy is the most common cause of heart failure. While it can be a genetic condition, it can also be caused by a heart attack or unhealthy lifestyle.

Agar advises others who may have a recurring theme of heart trouble in their family to seek care and not ignore it. With appropriate treatment, she says, cardiac problems dont necessarily have to significantly impact your quality of life. Remember that you are in charge of your own health. Pay attention to the advice of your health care professionals and do those things that are necessary for good health.

To learn more about the Calhoun Cardiology Center at UConn Health, visit: health.uconn.edu/cardiology.

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Cardiovascular Genetic Testing Empowers Patient, Family - UConn Today

Cardiac Stem Cells Comments Off on Cardiovascular Genetic Testing Empowers Patient, Family – UConn Today | February 15th, 2017

February 15, 2017 A single human induced pluripotent stem cell-derived cardiomyocyte (hiPSC-CM). Cells such as these were used to assess tyrosine kinase inhibitors for cardiotoxicity in a high-throughput fashion. Credit: Dr. Arun Sharma at Dr. Joseph Wus laboratory at Stanford University

Researchers at the Stanford University School of Medicine used heart muscle cells made from stem cells to rank commonly used chemotherapy drugs based on their likelihood of causing lasting heart damage in patients.

Drugs known as tyrosine kinase inhibitors can be an effective treatment for many types of cancers, but they also have severe and sometimes fatal side effects. Using lab-grown heart cells, Stanford researchers were able to assess the drugs' various effects on heart muscle cells, including whether the cells survived, were able to beat rhythmically and effectively, responded appropriately to electrophysiological signals and communicated with one another.

The researchers found that their assay can accurately identify those tyrosine kinase inhibitors already known to be the most dangerous in patients. In the future, they believe their system may prove useful in the early stages of drug development to screen new compounds for cardiotoxicity.

"This type of study represents a critical step forward from the usual process running from initial drug discovery and clinical trials in human patients," said Joseph Wu, MD, PhD, director of the Stanford Cardiovascular Institute and a professor of cardiovascular medicine and of radiology. "It will help pharmaceutical companies better focus their efforts on developing safer drugs, and it will provide patients more effective drugs with fewer side effects."

A paper describing the research will be published Feb. 15 in Science Translational Medicine. Wu, who holds the Simon H. Stertzer Professorship, is the senior author. Former graduate student Arun Sharma, PhD, is the lead author.

'Multiple measurements'

"We used multiple measurements to accurately predict which of the tyrosine kinase inhibitors were the most cardiotoxic," said Sharma. "The drugs with the lowest safety indices in our study were also those identified by the Food and Drug Administration as the most cardiotoxic to patients. Other drugs that are not as cardiotoxic performed much better in our assays."

Validating the researchers' cardiac-safety test on drugs with extensive clinical track records is necessary before the assay can be used to predict with confidence the likely clinical outcomes of drugs still under development.

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Sharma, Wu and their colleagues created heart muscle cells called cardiomyocytes from induced pluripotent stem cells, or iPS cells, from 11 healthy people and two people with kidney cancer. They grew the lab-made cardiomyocytes in a dish and tested the effects of 21 commonly used tyrosine kinase inhibitors on the cells.

They found that treatment with drug levels equivalent to those taken by patients often caused the cells to beat irregularly and begin to die. The cells also displayed differences in the electrophysiological signaling that controls their contraction. The researchers used these and other measurements to develop a cardiac safety index for each drug.

They found that those drugs known to be particularly dangerous to heart function, such as nilotinib, which is approved for the treatment of chronic myelogenous leukemia, and vandetanib, which is approved for the treatment of some types of thyroid cancer, also had the lowest safety indices based on the assay; conversely, those known to be better tolerated by patients ranked higher on their safety index. Prescribing information for both nilotinib and vandetanib contains warnings from the FDA about the drugs' potential cardiotoxicity.

An activity increase in an insulin responsive pathway

Six of the 21 tyrosine kinase inhibitors tested were assigned cardiac safety indices at or below 0.1the threshold limit at which the researchers designated a drug highly cardiotoxic. Three of these six are known to inhibit the same two signaling pathways: VEGFR2 and PDGFR. The researchers noticed that cells treated with these three drugs ramped up the activity of a cellular signaling pathway that responds to insulin or IGF1, an insulinlike growth factor.

This discovery, coupled with the fact that treatment with insulin or IGF1 is known to enhance heart function during adverse cardiac events such as heart attacks, led the researchers to experiment further. They found that exposing the cells to insulin or IGF1 made it less likely they would die due to tyrosine kinase inhibitors blocking the VEGFR2 and PDGFR pathways. Although more research is needed, these findings suggest it may be possible to alleviate some of the heart damage in patients receiving these chemotherapies.

The current study mirrors another by Wu's lab that was published in April 2016 in Nature Medicine. That research focused on the toxic effect of a chemotherapy drug called doxorubicin on iPS cell-derived cardiomyocytes. Doxorubicin, which indiscriminately kills any replicating cells, is increasingly being replaced by more targeted, cancer-specific therapies such as the tyrosine kinase inhibitors tested in the current study.

"The switch from doxorubicin is a result of the paradigm shift in cancer treatment to personalized, precise treatment as emphasized by President Obama's 2015 Precision Medicine Initiative," said Wu. "Moving even further, we're discovering that many tyrosine kinase inhibitors are themselves significantly cardiotoxic, and some have been withdrawn from the market. There is a critical need for a way to 'safety test' all drugs earlier in development before they are administered to patients. Our drug safety index is a step in that direction."

Explore further: Stem cell-based screening methods may predict heart-related side effects of drugs

More information: "High-throughput screening of tyrosine kinase inhibitor cardiotoxicity with human induced pluripotent stem cells," Science Translational Medicine, stm.sciencemag.org/lookup/doi/10.1126/scitranslmed.aaf2584

Coaxing stem cells from patients to become heart cells may help clinicians personalize drug treatments and prevent heart-related toxicity.

Heart muscle cells made from induced pluripotent stem cells faithfully mirror the expression patterns of key genes in the donor's native heart tissue, according to researchers at the Stanford University School of Medicine. ...

Researchers at Moffitt Cancer Center have determined that chronic myeloid leukemia patients who are treated with a class of oral chemotherapy drugs known as a tyrosine kinase inhibitors have significant side effects and quality-of-life ...

Some cancers can be effectively treated with drugs inhibiting proteins known as receptor tyrosine kinases, but not those cancers caused by mutations in the KRAS gene. A team of researchers led by Jeffrey Engelman, at Massachusetts ...

Acute myeloid leukemia (AML) is a cancer of myeloid stem cells that develops in both adult and pediatric populations. Mutations that cause hyperactivation of the FMS-like tyrosine kinase 3 (FLT3) are commonly found in AML, ...

Fat cells are not simply big blobs of lipid quietly standingby in the bodyinstead, they send out hormones and other signaling proteins that affect many types of tissues. Scientists at Joslin Diabetes Center now have identified ...

Researchers at the Stanford University School of Medicine used heart muscle cells made from stem cells to rank commonly used chemotherapy drugs based on their likelihood of causing lasting heart damage in patients.

Research published today in Nature from scientists at Huntsman Cancer Institute (HCI) at the University of Utah shows how epithelial cells naturally turn over, maintaining constant numbers between cell division and cell death.

Scientists are working to understand the mechanisms that make weight loss so complicated. Exercise burns calories, of course, but scientists are also looking at how the body burns more energy to stay warm in cold temperatures.

Biologists have known for decades that enduring a short period of mild stress makes simple organisms and human cells better able to survive additional stress later in life. Now, scientists at Sanford Burnham Prebys Medical ...

A puzzling question has lurked behind SMA (spinal muscular atrophy), the leading genetic cause of death in infants.

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Scientists create scorecard index for heart-damaging chemo drugs - Medical Xpress

Cardiac Stem Cells Comments Off on Scientists create scorecard index for heart-damaging chemo drugs – Medical Xpress | February 15th, 2017

Scientists are one step closer to mimicking the way biological systems interact and process information in the body -- a vital step toward developing new forms of biorobotics and novel treatment approaches for several muscle-related health problems such as muscular degenerative disorders, arrhythmia and limb loss.

Using cardiac muscle cells and cardiac fibroblasts -- cells found in connective heart tissue -- researchers at the University of Notre Dame have created a "living diode," which can be used for cell-based information processing, according to a recent study in Advanced Biosystems. Bioengineers created the muscle-based circuitry through a novel, self-forming, micro patterning approach.

Using muscle cells opens the door to functional, biological structures or "computational tissues" that would allow an organ to control and direct mechanical devices in the body. The design arranges the two types of cells in a rectangular pattern, separating excitable cells from nonexcitable cells, allowing the team to transduce electrical signals unidirectionally and achieve a diode function using living cells. In addition to the diode-like function, the natural pacing ability of the muscle cells allowed Pinar Zorlutuna, assistant professor of aerospace and mechanical engineering, and her team to pass along information embedded in the electrical signals by modulating the frequency of the cells' electrical activity. Zorlutuna's research was funded by the National Science Foundation.

"Muscle cells have the unique ability to respond to external signals while being connected to fibroblasts internally through intercellular junctions. By combining these two cell types, we have the ability to initiate, amplify and propagate signals directionally," said Zorlutuna, who is also director of the Tissue Engineering Laboratory at the university. "The success of these muscle-cell diodes offers a path toward linking such cell-based circuitry to a living system -- and creating functional control units for biomedical engineering applications such as bioactuators or biosensors."

The team's work presents a new option in biocomputing, which has focused primarily on using gene circuitries of genetically modified single-cells or neuronal networks doped with chemical additives to create information processing systems. The single-cell options are slower to process information since they relay on chemical processes, and neuronal-based approaches can misfire signals, firing backward up to 10 percent of the time.

Zorlutuna explores biomimetic environments in order to understand and control cell behavior. She also studies cell-cell and cell-environment interactions through tissue and genetic engineering, and micro- and nanotechnology at the Notre Dame Center for Nano Science and Technology. She is a researcher at the University's Center for Stem Cells and Regenerative Medicine and the Harper Cancer Research Institute.

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Researchers develop 'living diode' using cardiac muscle cells - Science Daily

Cardiac Stem Cells Comments Off on Researchers develop ‘living diode’ using cardiac muscle cells – Science Daily | February 15th, 2017

BusinessKorea

Myocardial Stem Cell Patch Developed with 3D Printer BusinessKorea The myocardial patch, which is printed with a 3D printer and attached to the hearts of such patients for blood vessel and tissue regeneration, has a structure in which cardiac extracellular matrices are used as bio ink and cardiac stem cells and ...

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Myocardial Stem Cell Patch Developed with 3D Printer - BusinessKorea

Cardiac Stem Cells Comments Off on Myocardial Stem Cell Patch Developed with 3D Printer – BusinessKorea | February 11th, 2017

When Becky's baby girl started sweating, vomiting and struggling to breathe while breastfeeding , she knew something was wrong.

But despite taking her daughter, Kirsty, to the GP numerous times, she was dismissed as "neurotic" and "unable to cope", a new book reveals.

Even when the six-month-old was finally referred to hospital for X-Rays, paediatricians wrongly diagnosed her condition as bronchitis.

It was only when she was close to death, lying limp and grey in her terrified mum's arms, that the true cause of her illness was diagnosed.

She had severe heart failure after "multiple heart attacks" - which she had suffered from 'silently', unable to communicate or understand them.

Kirsty wasnt gaining weight," writes world-famous cardiac surgeon Stephen Westaby in his remarkable book, Fragile Lives , published today.

"She had a pasty, washed-out look and a cough like a dogs bark.

In reality, this baby was suffering repeated small heart attacks with excruciating chest pain that she could neither communicate nor understand.

"The human body can be outlandishly cruel.

Stephen, from Oxford, operated on Kirsty following her ALCAPA (anomalous left coronary artery from the pulmonary artery) diagnosis.

He found the situation "even worse" than he had thought and, at one point, Becky and her husband were warned they would likely lose their baby.

However, in a desperate, last-ditch attempt to save the youngster's life, Stephen carried out a procedure that had never been done before in a child.

He made her heart smaller by removing almost a third of it, before stitching the organ back up until it looked like a "quivering black banana".

Amazingly, he saved his tiny patient's life.

Today, Kirsty is an 18-year-old, athletic student. She has been able to attend school, go to prom and spend time with her friends.

Her incredible story is one of many featured in Stephen's new book, which details some of the surgeon's most extraordinary and poignant cases.

Others include a woman who lived the horror of locked-in syndrome, and a man whose life was powered by a battery for more than seven years

They all include drama, emotion and blood (lots of it).

Having grown up on a council estate in Scunthorpe, North Lincolnshire, Stephen went into cardiac surgery after watching his granddad die of heart failure.

He tells Mirror Online that, despite his passion for the speciality and his determination, he "never anticipated" he would even get to medical school.

But over the past nearly 40 years, he has become an acclaimed heart surgeon and pioneer, responsible for a number of significant developments in the field.

He invented a T-Y stent - dubbed the "Westaby" tube - to bypass damaged airways, and became the first surgeon to fit a patient with a new type of artificial heart.

The patient, Peter, died aged 69 after over seven years of "extra life". "He was the first to reveal the true potential of blood pump technology," writes Stephen in his book.

The surgeon, who has worked in hospitals in the UK and abroad, says he learned "very early on" that a lot of patients were being turned away for heart transplants.

"Although transplants were great for patients, a lot of others were being turned away," he says. "Very few people can have heart transplants.

"They need someone else to die to get their heart.

He says that, even as a trainee, he was interested in alternative options for the unfortunate patients who could not receive a transplant.

In his book, he describes how, as a student, he was called to assist an operation on a young car crash victim after drinking pints in the pub.

"Bad problem, both the injury and the beer," he writes in his book.

"Not so much the amount of alcohol - we were used to that - more the volume of urine to pass during a four-hour operation."

To get through the surgery without losing concentration or having to leave, he reveals how he used rubber tubing so his urine would run into his surgical boots.

He admits, at one point, he had to cough loudly to disguise the "squelching sound".

When you start doing any surgery, it is scary. It takes you a few months to get into," says the dad-of-two. "Its very taxing."

In subsequent decades, Stephen went on to save hundreds of lives, repeatedly taking chances and pushing the boundaries of heart surgery.

This was all part of being a pioneer, pushing the profession to its limit," he says.

Far from working nine-to-five, the surgeon spent his mornings, afternoons and evenings dedicated to his "day job".

To become a heart surgeon I believe you have to work continuously in the way I did in the old days," he tells Mirror Online.

"We had ward rounds at 5am, then wed operate at 7am.

Stephen would spend the rest of the day operating on patients, before going to the research lab. In the evenings, he'd return to intensive care.

"It needs that sort of dedication," he says.

Indeed, it was this dedication that saw him cut a conference in Australia short to rush back to perform life-saving surgery on Kirsty.

Stephen had been in the country for just 13 hours when he received a call from Nick Archer, his paediatric cardiology colleague at Oxfords John Radcliffe Hospital.

No one calls with good news at night, he notes in his book.

And he was right.

He was told that there was a sick baby with ALCAPA - a rare but serious cardiac anomaly - who desperately needed his help.

He later discovered that Kirsty - in whom fate had installed a lethal self-destruct mechanism" - had shown signs of distress within days of her birth.

Her mum Becky, who already had a three-year-old son, noticed beads of sweat were trickling from her baby's nose whenever she tried to breastfeed her.

However, a paediatrician dismissed the infant's symptoms, Stephen writes in his book, deeming the move an example of "p***-poor medicine".

Within a matter of weeks, Kirsty was sweating, vomiting and struggling to breathe during feeds. However, she had no temperature.

Her concerned mum repeatedly took her to visit the doctor, but was "deemed neurotic and unable to cope", according to Fragile Lives.

At the time, Becky's husband was working abroad, away from their daughter who had a "pasty look" and a "cough like a dog's bark".

After eventually managing to get Kirsty referred to a hospital for X-Rays, Becky was told that her baby was suffering from bronchitis.

Feeling desperate and certain that something "dreadful" was going to happen, she later took the "grey" youngster to another hospital.

But there, she was diagnosed with the same condition.

Now late at night, Becky demanded a further X-Ray. Shockingly, she was "told off for her unreasonable attitude," Stephen writes in his moving book.

However, after the scan, the mum finally had her fears confirmed.

Her daughter was found to have a massive heart, with medics having reportedly misinterpreted heart shadows on her X-Rays as fluid.

Kirsty was rushed to Oxford's specialist childrens heart unit. By then, she was very cold and suffering from severe heart failure, Stephen says.

While flying back from Australia, the surgeon devised an alternative technique for the operation in a bid to increase the baby's chance of survival.

After landing in the UK, however, he was shocked by Kirsty's condition.

"She was emaciated, with virtually no body fat, her heaving ribs and rapid breathing a consequence of her congested lungs, and her abdomen swollen with fluid," he writes.

He adds: Without immediate surgery, shed be dead within days.

Joined by his surgical team, Stephen opened up the baby's small body with a scalpel blade, an electrical saw and a rib retractor while her parents faced an anxious wait.

He describes in his book how he found her heart to be the size of a lemon.

Babies' hearts are typically the size of a walnut.

Stephen then goes on to explain how he replumbed Kirsty's heart's blood supply and removed up to 30 per cent of her organ in an attempt to save her.

Incredibly, the surgery was a success.

The operation "provided some of the first evidence that an infants own cardiac stem cells can regenerate heart muscle and actually remove fibrous tissue," Stephen says.

"Adult hearts cannot recover in the same way," he writes.

Speaking to the Mirror Online, the surgeon describes how he "always put the patient first", even if it meant the possibility of being sacked.

He admits he did things "off piste" and, when he didn't have the money to perform certain procedures, he would raise charitable funds.

I used to operate on everyone from premature babies in their cots to people all the way through to their nineties," he says.

"Every one is precious."

He adds that it takes a "special sort of person" - one who is extremely skilled, gutsy and empathetic - to operate on babies and children.

"I think you find it difficult every time you lose a patient, no matter how high risk they are," he says.

"I used to really hate having to go out of an operating theatre and telling [relatives] their loved one had died.

Stephen, who describes his own story as one of "grim determination", worked on around 12,000 patients during his career.

He estimates between 300 and 400 died earlier than they would have.

I did lose an awful lot of patients," he says.

"There are lots of cases that have stuck with me.

But he adds: "Very few heart patients die because the surgeon doesnt do a good job.

He says some patients suffer complications which aren't managed well, while the quality of the intensive care team can also have an impact.

Nowadays, surgeons' death rates are published. There is also a risk of legal action by grief-stricken and angry relatives, Stephen says.

This 'naming and shaming' culture, he claims, is having a negative effect on the profession and putting graduates off from going into heart surgery.

"It's a worrying time for trainees," he says, describing how there are "serious weaknesses" with the system. "Surgeons now have their death rates published."

He adds that this also means it's difficult to maintain consistent intensive care teams.

"There's a lot of agency nurses, people not familiar with protocol," he says.

Stephen, who established the Oxford Heart Centre in the 1980s, recently retired from surgery after developing Dupuytren's contracture, or a 'claw hand'.

"My hand was warped into the position in which I held the scissors, the needle holder, the sternal saw," the 68-year-old writes in his book.

Now, he is working in two "very exciting" roles, one of which involves a proposed Wellness and Life Science Village in Llanelli, Wales.

He is also medical director at the regenerative medicine firm, Celixir , which he says has made "very important" developments for people with heart failure.

Reflecting on his incredible career, Stephen, who lives with his wife, Sarah, 63, acknowledges that he "didn't give enough time" to his family.

He met his spouse - a "free spirit from Africa" - over an open chest in Accident & Emergency, where she was working as a sister.

Stephen has a 38-year-old daughter - by his first wife, Jane - and a 28-year-old son - by Sarah, as well as two young granddaughters.

I never gave enough time to my kids and my grandchildren," he admits.

But he adds that one of the reasons he wrote his book, "was so they could see why I wasnt with them as much as I could be".

Stephen appeared on ITV's This Morning today, along with Kirsty and Becky.

Viewers have since taken to social media to praise his "amazing" and "remarkable" work, with some calling for him to be knighted.

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Mum dismissed as 'neurotic and unable to cope' after baby girl ... - Mirror.co.uk

Cardiac Stem Cells Comments Off on Mum dismissed as ‘neurotic and unable to cope’ after baby girl … – Mirror.co.uk | February 9th, 2017

A new revolutionary stem cell technique is being used to treat those suffering from damaged muscles without the cancer risk that was previously present. This was the first time that researchers had successfully implanted synthetic stem cardiac cells that managed to repair the muscle that a previous heart attack has weakened. Cancer was previously a risk with traditional stem cell therapy as scientists were unable to stop formertumors as the cells continued to replicate.

This procedure is mostly performed on those suffering from blood or bone marrow cancers such as leukemia. But, researchers are also working on developing effective stem cell treatments for those diagnosed with neurodegenerative diseases such as Parkinsons and heart disease too.

Synthetic stem cells are very handy because unlike natural stem cells, theyre easy to preserve and can be adapted to be used in various parts of the body. Ke Cheng, associate professor of molecular biomedical sciences at North Carolina State University, said, We are hoping that this may be the first step towards a truly off-the-shelf cell product that would enable people to receive beneficial stem cell therapies when theyre needed, without costly delays.

[The study can be found here.]

The GLP aggregated and excerpted this blog/article to reflect the diversity of news, opinion, and analysis. Read full, original post:Pioneering Stem Cell Technique Promise Muscle Regeneration Without Cancer Risk

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Regrowing heart muscles without cancer risk, using synthetic stem cells - Genetic Literacy Project

Cardiac Stem Cells Comments Off on Regrowing heart muscles without cancer risk, using synthetic stem cells – Genetic Literacy Project | February 7th, 2017

Induced pluripotent stem cells (iPSCs) are adult cells that have been genetically reprogrammed to an embryonic stem celllike state by being forced to express genes and factors important for maintaining the defining properties of embryonic stem cells. Although these cells meet the defining criteria for pluripotent stem cells, it is not known if iPSCs and embryonic stem cells differ in clinically significant ways. Mouse iPSCs were first reported in 2006, and human iPSCs were first reported in late 2007. Mouse iPSCs demonstrate important characteristics of pluripotent stem cells, including expressing stem cell markers, forming tumors containing cells from all three germ layers, and being able to contribute to many different tissues when injected into mouse embryos at a very early stage in development. Human iPSCs also express stem cell markers and are capable of generating cells characteristic of all three germ layers.

Although additional research is needed, iPSCs are already useful tools for drug development and modeling of diseases, and scientists hope to use them in transplantation medicine. Viruses are currently used to introduce the reprogramming factors into adult cells, and this process must be carefully controlled and tested before the technique can lead to useful treatment for humans. In animal studies, the virus used to introduce the stem cell factors sometimes causes cancers. Researchers are currently investigating non-viral delivery strategies. In any case, this breakthrough discovery has created a powerful new way to "de-differentiate" cells whose developmental fates had been previously assumed to be determined. In addition, tissues derived from iPSCs will be a nearly identical match to the cell donor and thus probably avoid rejection by the immune system. The iPSC strategy creates pluripotent stem cells that, together with studies of other types of pluripotent stem cells, will help researchers learn how to reprogram cells to repair damaged tissues in the human body.

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Stem Cell Basics VI. | stemcells.nih.gov

Cardiac Stem Cells Comments Off on Stem Cell Basics VI. | stemcells.nih.gov | February 3rd, 2017

Cardiac muscle cells or cardiomyocytes (also known as myocardiocytes[1] or cardiac myocytes[2]) are the muscle cells (myocytes) that make up the cardiac muscle. Each myocardial cell contains myofibrils, which are specialized organelles consisting of long chains of sarcomeres, the fundamental contractile units of muscle cells. Cardiomyocytes show striations similar to those on skeletal muscle cells. Unlike multinucleated skeletal cells, the majority of cardiomyocytes contain only one nucleus, although they may have as many as four.[3] Cardiomyocytes have a high mitochondrial density, which allows them to produce adenosine triphosphate (ATP) quickly, making them highly resistant to fatigue.

There are two types of cells within the heart: the cardiomyocytes and the cardiac pacemaker cells. Cardiomyocytes make up the atria (the chambers in which blood enters the heart) and the ventricles (the chambers where blood is collected and pumped out of the heart). These cells must be able to shorten and lengthen their fibers and the fibers must be flexible enough to stretch. These functions are critical to the proper form during the beating of the heart.[4]

Cardiac pacemaker cells carry the impulses that are responsible for the beating of the heart. They are distributed throughout the heart and are responsible for several functions. First, they are responsible for being able to spontaneously generate and send out electrical impulses. They also must be able to receive and respond to electrical impulses from the brain. Lastly, they must be able to transfer electrical impulses from cell to cell.[5]

All of these cells are connected by cellular bridges. Porous junctions called intercalated discs form junctions between the cells. They permit sodium, potassium and calcium to easily diffuse from cell to cell. This makes it easier for depolarization and repolarization in the myocardium. Because of these junctions and bridges the heart muscle is able to act as a single coordinated unit.[6][7]

The cardiomyocytes are about 100 to 150 micrometers long and 15 to 20 micrometers in diameter.[citation needed]

Humans are born with a set number of heart muscle cells, or cardiomyocytes, which increase in size as heart grows larger during childhood development. Recent evidence suggests that cardiomyocytes are actually slowly turned over as we age, but that less than 50% of the cardiomyocytes we are born with are replaced during a normal life span.[8] The growth of individual cardiomyocytes not only occurs during normal heart development, it also occurs in response to extensive exercise (athletic heart syndrome), heart disease, or heart muscle injury such as after a myocardial infarction. A healthy adult cardiomyocyte has a cylindrical shape that is approximately 100m long and 10-25m in diameter. Cardiomyocyte hypertrophy occurs through sarcomerogenesis, the creation of new sarcomere units in the cell. During heart volume overload, cardiomyocytes grow through eccentric hypertrophy.[9] The cardiomyocytes extend lengthwise but have the same diameter, resulting in ventricular dilation. During heart pressure overload, cardiomyocytes grow through concentric hypertrophy.[9] The cardiomyocytes grow larger in diameter but have the same length, resulting in heart wall thickening.

Cardiac action potential consists of two cycles, a rest phase and an active phase. These two phases are commonly understood as systole and diastole. The rest phase is considered polarized. The resting potential during this phase of the beat separates the ions such as sodium, potassium and calcium. Myocardial cells possess the property of automaticity or spontaneous depolarization. This is the direct result of a membrane which allows sodium ions to slowly enter the cell until the threshold is reached for depolarization. Calcium ions follow and extend the depolarization even further. Once calcium stops moving inward, potassium ions move out slowly to produce repolarization. The very slow repolarization of the CMC membrane is responsible for the long refractory period.[10][11]

Myocardial infarction, commonly known as a heart attack, occurs when the heart's supplementary blood vessels are obstructed by an unstable build-up of white blood cells, cholesterol, and fat. With no blood flow, the cells die, causing whole portions of cardiac tissue to die. Once these tissues are lost, they cannot be replaced, thus causing permanent damage. Current research indicates, however, that it may be possible to repair damaged cardiac tissue with stem cells,[12] as human embryonic stem cells can differentiate into cardiomyocytes under appropriate conditions.[13]

The cardiomyopathies are a group of diseases characterized by disruptions to cardiac muscle cell growth and / or organization. Presentation can range from asymptomatic to sudden cardiac death.

Cardiomyopathy can be caused by genetic, endocrine, environmental, or other factors.

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Cardiac muscle cell - Wikipedia

Cardiac Stem Cells Comments Off on Cardiac muscle cell – Wikipedia | February 3rd, 2017

Induced stem cells (iSC) are stem cells derived from somatic, reproductive, pluripotent or other cell types by deliberate epigenetic reprogramming. They are classified as either totipotent (iTC), pluripotent (iPSC) or progenitor (multipotentiMSC, also called an induced multipotent progenitor celliMPC) or unipotent(iUSC) according to their developmental potential and degree of dedifferentiation. Progenitors are obtained by so-called direct reprogramming or directed differentiation and are also called induced somatic stem cells.

Three techniques are widely recognized:[1]

In 1895 Thomas Morgan removed one of a frog's two blastomeres and found that amphibians are able to form whole embryos from the remaining part. This meant that the cells can change their differentiation pathway. In 1924 Spemann and Mangold demonstrated the key importance of cellcell inductions during animal development.[20] The reversible transformation of cells of one differentiated cell type to another is called metaplasia.[21] This transition can be a part of the normal maturation process, or caused by an inducement.

One example is the transformation of iris cells to lens cells in the process of maturation and transformation of retinal pigment epithelium cells into the neural retina during regeneration in adult newt eyes. This process allows the body to replace cells not suitable to new conditions with more suitable new cells. In Drosophila imaginal discs, cells have to choose from a limited number of standard discrete differentiation states. The fact that transdetermination (change of the path of differentiation) often occurs for a group of cells rather than single cells shows that it is induced rather than part of maturation.[22]

The researchers were able to identify the minimal conditions and factors that would be sufficient for starting the cascade of molecular and cellular processes to instruct pluripotent cells to organize the embryo. They showed that opposing gradients of bone morphogenetic protein (BMP) and Nodal, two transforming growth factor family members that act as morphogens, are sufficient to induce molecular and cellular mechanisms required to organize, in vivo or in vitro, uncommitted cells of the zebrafish blastula animal pole into a well-developed embryo.[23]

Some types of mature, specialized adult cells can naturally revert to stem cells. For example, "chief" cells express the stem cell marker Troy. While they normally produce digestive fluids for the stomach, they can revert into stem cells to make temporary repairs to stomach injuries, such as a cut or damage from infection. Moreover, they can make this transition even in the absence of noticeable injuries and are capable of replenishing entire gastric units, in essence serving as quiescent "reserve" stem cells.[24] Differentiated airway epithelial cells can revert into stable and functional stem cells in vivo.[25]

After injury, mature terminally differentiated kidney cells dedifferentiate into more primordial versions of themselves and then differentiate into the cell types needing replacement in the damaged tissue[26] Macrophages can self-renew by local proliferation of mature differentiated cells.[27][28] In newts, muscle tissue is regenerated from specialized muscle cells that dedifferentiate and forget the type of cell they had been. This capacity to regenerate does not decline with age and may be linked to their ability to make new stem cells from muscle cells on demand.[29]

A variety of nontumorigenic stem cells display the ability to generate multiple cell types. For instance, multilineage-differentiating stress-enduring (Muse) cells are stress-tolerant adult human stem cells that can self-renew. They form characteristic cell clusters in suspension culture that express a set of genes associated with pluripotency and can differentiate into endodermal, ectodermal and mesodermal cells both in vitro and in vivo.[30][31][32][33][34]

Other well-documented examples of transdifferentiation and their significance in development and regeneration were described in detail.[35][36]

Induced totipotent cells can be obtained by reprogramming somatic cells with somatic-cell nuclear transfer (SCNT). The process involves sucking out the nucleus of a somatic (body) cell and injecting it into an oocyte that has had its nucleus removed[3][5][37][38]

Using an approach based on the protocol outlined by Tachibana et al.,[3] hESCs can be generated by SCNT using dermal fibroblasts nuclei from both a middle-aged 35-year-old male and an elderly, 75-year-old male, suggesting that age-associated changes are not necessarily an impediment to SCNT-based nuclear reprogramming of human cells.[39] Such reprogramming of somatic cells to a pluripotent state holds huge potentials for regenerative medicine. Unfortunately, the cells generated by this technology, potentially are not completely protected from the immune system of the patient (donor of nuclei), because they have the same mitochondrial DNA, as a donor of oocytes, instead of the patients mitochondrial DNA. This reduces their value as a source for autologous stem cell transplantation therapy, as for the present, it is not clear whether it can induce an immune response of the patient upon treatment.

Induced androgenetic haploid embryonic stem cells can be used instead of sperm for cloning. These cells, synchronized in M phase and injected into the oocyte can produce viable offspring.[40]

These developments, together with data on the possibility of unlimited oocytes from mitotically active reproductive stem cells,[41] offer the possibility of industrial production of transgenic farm animals. Repeated recloning of viable mice through a SCNT method that includes a histone deacetylase inhibitor, trichostatin, added to the cell culture medium,[42] show that it may be possible to reclone animals indefinitely with no visible accumulation of reprogramming or genomic errors[43] However, research into technologies to develop sperm and egg cells from stem cells raises bioethical issues.[44]

Such technologies may also have far-reaching clinical applications for overcoming cytoplasmic defects in human oocytes.[3][45] For example, the technology could prevent inherited mitochondrial disease from passing to future generations. Mitochondrial genetic material is passed from mother to child. Mutations can cause diabetes, deafness, eye disorders, gastrointestinal disorders, heart disease, dementia and other neurological diseases. The nucleus from one human egg has been transferred to another, including its mitochondria, creating a cell that could be regarded as having two mothers. The eggs were then fertilised and the resulting embryonic stem cells carried the swapped mitochondrial DNA.[46] As evidence that the technique is safe author of this method points to the existence of the healthy monkeys that are now more than four years old and are the product of mitochondrial transplants across different genetic backgrounds.[47]

In late-generation telomerase-deficient (Terc/) mice, SCNT-mediated reprogramming mitigates telomere dysfunction and mitochondrial defects to a greater extent than iPSC-based reprogramming.[48]

Other cloning and totipotent transformation achievements have been described.[49]

Recently some researchers succeeded to get the totipotent cells without the aid of SCNT. Totipotent cells were obtained using the epigenetic factors such as oocyte germinal isoform of histone.[50] Reprogramming in vivo, by transitory induction of the four factors Oct4, Sox2, Klf4 and c-Myc in mice, confers totipotency features. Intraperitoneal injection of such in vivo iPS cells generates embryo-like structures that express embryonic and extraembryonic (trophectodermal) markers.[51]

iPSc were first obtained in the form of transplantable teratocarcinoma induced by grafts taken from mouse embryos.[52] Teratocarcinoma formed from somatic cells.[53]Genetically mosaic mice were obtained from malignant teratocarcinoma cells, confirming the cells' pluripotency.[54][55][56] It turned out that teratocarcinoma cells are able to maintain a culture of pluripotent embryonic stem cell in an undifferentiated state, by supplying the culture medium with various factors.[57] In the 1980s, it became clear that transplanting pluripotent/embryonic stem cells into the body of adult mammals, usually leads to the formation of teratomas, which can then turn into a malignant tumor teratocarcinoma.[58] However, putting teratocarcinoma cells into the embryo at the blastocyst stage, caused them to become incorporated in the inner cell mass and often produced a normal chimeric (i.e. composed of cells from different organisms) animal.[59][60][61] This indicated that the cause of the teratoma is a dissonance - mutual miscommunication between young donor cells and surrounding adult cells (the recipient's so-called "niche").

In August 2006, Japanese researchers circumvented the need for an oocyte, as in SCNT. By reprograming mouse embryonic fibroblasts into pluripotent stem cells via the ectopic expression of four transcription factors, namely Oct4, Sox2, Klf4 and c-Myc, they proved that the overexpression of a small number of factors can push the cell to transition to a new stable state that is associated with changes in the activity of thousands of genes.[7]

Reprogramming mechanisms are thus linked, rather than independent and are centered on a small number of genes.[62] IPSC properties are very similar to ESCs.[63] iPSCs have been shown to support the development of all-iPSC mice using a tetraploid (4n) embryo,[64] the most stringent assay for developmental potential. However, some genetically normal iPSCs failed to produce all-iPSC mice because of aberrant epigenetic silencing of the imprinted Dlk1-Dio3 gene cluster.[18]

An important advantage of iPSC over ESC is that they can be derived from adult cells, rather than from embryos. Therefore, it became possible to obtain iPSC from adult and even elderly patients.[9][65][66]

Reprogramming somatic cells to iPSC leads to rejuvenation. It was found that reprogramming leads to telomere lengthening and subsequent shortening after their differentiation back into fibroblast-like derivatives.[67] Thus, reprogramming leads to the restoration of embryonic telomere length,[68] and hence increases the potential number of cell divisions otherwise limited by the Hayflick limit.[69]

However, because of the dissonance between rejuvenated cells and the surrounding niche of the recipient's older cells, the injection of his own iPSC usually leads to an immune response,[70] which can be used for medical purposes,[71] or the formation of tumors such as teratoma.[72] The reason has been hypothesized to be that some cells differentiated from ESC and iPSC in vivo continue to synthesize embryonic protein isoforms.[73] So, the immune system might detect and attack cells that are not cooperating properly.

A small molecule called MitoBloCK-6 can force the pluripotent stem cells to die by triggering apoptosis (via cytochrome c release across the mitochondrial outer membrane) in human pluripotent stem cells, but not in differentiated cells. Shortly after differentiation, daughter cells became resistant to death. When MitoBloCK-6 was introduced to differentiated cell lines, the cells remained healthy. The key to their survival, was hypothesized to be due to the changes undergone by pluripotent stem cell mitochondria in the process of cell differentiation. This ability of MitoBloCK-6 to separate the pluripotent and differentiated cell lines has the potential to reduce the risk of teratomas and other problems in regenerative medicine.[74]

In 2012 other small molecules (selective cytotoxic inhibitors of human pluripotent stem cellshPSCs) were identified that prevented human pluripotent stem cells from forming teratomas in mice. The most potent and selective compound of them (PluriSIn #1) inhibits stearoyl-coA desaturase (the key enzyme in oleic acid biosynthesis), which finally results in apoptosis. With the help of this molecule the undifferentiated cells can be selectively removed from culture.[75][76] An efficient strategy to selectively eliminate pluripotent cells with teratoma potential is targeting pluripotent stem cell-specific antiapoptotic factor(s) (i.e., survivin or Bcl10). A single treatment with chemical survivin inhibitors (e.g., quercetin or YM155) can induce selective and complete cell death of undifferentiated hPSCs and is claimed to be sufficient to prevent teratoma formation after transplantation.[77] However, it is unlikely that any kind of preliminary clearance,[78] is able to secure the replanting iPSC or ESC. After the selective removal of pluripotent cells, they re-emerge quickly by reverting differentiated cells into stem cells, which leads to tumors.[79] This may be due to the disorder of let-7 regulation of its target Nr6a1 (also known as Germ cell nuclear factor - GCNF), an embryonic transcriptional repressor of pluripotency genes that regulates gene expression in adult fibroblasts following micro-RNA miRNA loss.[80]

Teratoma formation by pluripotent stem cells may be caused by low activity of PTEN enzyme, reported to promote the survival of a small population (0,1-5% of total population) of highly tumorigenic, aggressive, teratoma-initiating embryonic-like carcinoma cells during differentiation. The survival of these teratoma-initiating cells is associated with failed repression of Nanog as well as a propensity for increased glucose and cholesterol metabolism.[81] These teratoma-initiating cells also expressed a lower ratio of p53/p21 when compared to non-tumorigenic cells.[82] In connection with the above safety problems, the use iPSC for cell therapy is still limited.[83] However, they can be used for a variety of other purposes - including the modeling of disease,[84] screening (selective selection) of drugs, toxicity testing of various drugs.[85]

It is interesting to note that the tissue grown from iPSCs, placed in the "chimeric" embryos in the early stages of mouse development, practically do not cause an immune response (after the embryos have grown into adult mice) and are suitable for autologous transplantation[86] At the same time, full reprogramming of adult cells in vivo within tissues by transitory induction of the four factors Oct4, Sox2, Klf4 and c-Myc in mice results in teratomas emerging from multiple organs.[51] Furthermore, partial reprogramming of cells toward pluripotency in vivo in mice demonstrates that incomplete reprogramming entails epigenetic changes (failed repression of Polycomb targets and altered DNA methylation) in cells that drive cancer development.[87]

Determining the unique set of cellular factors that is needed to be manipulated for each cell conversion is a long and costly process that involved much trial and error. As a result, this first step of identifying the key set of cellular factors for cell conversion is the major obstacle researchers face in the field of cell reprogramming. An international team of researchers have developed an algorithm, called Mogrify(1), that can predict the optimal set of cellular factors required to convert one human cell type to another. When tested, Mogrify was able to accurately predict the set of cellular factors required for previously published cell conversions correctly. To further validate Mogrify's predictive ability, the team conducted two novel cell conversions in the laboratory using human cells and these were successful in both attempts solely using the predictions of Mogrify.[89][90][91] Mogrify has been made available online for other researchers and scientists.

By using solely small molecules, Deng Hongkui and colleagues demonstrated that endogenous "master genes" are enough for cell fate reprogramming. They induced a pluripotent state in adult cells from mice using seven small-molecule compounds.[17] The effectiveness of the method is quite high: it was able to convert 0.02% of the adult tissue cells into iPSCs, which is comparable to the gene insertion conversion rate. The authors note that the mice generated from CiPSCs were "100% viable and apparently healthy for up to 6 months". So, this chemical reprogramming strategy has potential use in generating functional desirable cell types for clinical applications.[92][93]

In 2015th year a robust chemical reprogramming system was established with a yield up to 1,000-fold greater than that of the previously reported protocol. So, chemical reprogramming became a promising approach to manipulate cell fates.[94]

The fact that human iPSCs capable of forming teratomas not only in humans but also in some animal body, in particular in mice or pigs, allowed to develop a method for differentiation of iPSCs in vivo. For this purpose, iPSCs with an agent for inducing differentiation into target cells are injected to genetically modified pig or mouse that has suppressed immune system activation on human cells. The formed teratoma is cut out and used for the isolation of the necessary differentiated human cells[95] by means of monoclonal antibody to tissue-specific markers on the surface of these cells. This method has been successfully used for the production of functional myeloid, erythroid and lymphoid human cells suitable for transplantation (yet only to mice).[96] Mice engrafted with human iPSC teratoma-derived hematopoietic cells produced human B and T cells capable of functional immune responses. These results offer hope that in vivo generation of patient customized cells is feasible, providing materials that could be useful for transplantation, human antibody generation and drug screening applications. Using MitoBloCK-6[74] and/or PluriSIn # 1 the differentiated progenitor cells can be further purified from teratoma forming pluripotent cells. The fact, that the differentiation takes place even in the teratoma niche, offers hope that the resulting cells are sufficiently stable to stimuli able to cause their transition back to the dedifferentiated (pluripotent) state and therefore safe. A similar in vivo differentiation system, yielding engraftable hematopoietic stem cells from mouse and human iPSCs in teratoma-bearing animals in combination with a maneuver to facilitate hematopoiesis, was described by Suzuki et al.[97] They noted that neither leukemia nor tumors were observed in recipients after intravenous injection of iPSC-derived hematopoietic stem cells into irradiated recipients. Moreover, this injection resulted in multilineage and long-term reconstitution of the hematolymphopoietic system in serial transfers. Such system provides a useful tool for practical application of iPSCs in the treatment of hematologic and immunologic diseases.[98]

For further development of this method animal in which is grown the human cell graft, for example mouse, must have so modified genome that all its cells express and have on its surface human SIRP.[99] To prevent rejection after transplantation to the patient of the allogenic organ or tissue, grown from the pluripotent stem cells in vivo in the animal, these cells should express two molecules: CTLA4-Ig, which disrupts T cell costimulatory pathways and PD-L1, which activates T cell inhibitory pathway.[100]

See also: US 20130058900 patent.

In the near-future, clinical trials designed to demonstrate the safety of the use of iPSCs for cell therapy of the people with age-related macular degeneration, a disease causing blindness through retina damaging, will begin. There are several articles describing methods for producing retinal cells from iPSCs[101][102] and how to use them for cell therapy.[103][104] Reports of iPSC-derived retinal pigmented epithelium transplantation showed enhanced visual-guided behaviors of experimental animals for 6 weeks after transplantation.[105] However, clinical trials have been successful: ten patients suffering from retinitis pigmentosa have had their eyesight restoredincluding a woman who had only 17 percent of her vision left.[106]

Chronic lung diseases such as idiopathic pulmonary fibrosis and cystic fibrosis or chronic obstructive pulmonary disease and asthma are leading causes of morbidity and mortality worldwide with a considerable human, societal and financial burden. So there is an urgent need for effective cell therapy and lung tissue engineering.[107][108] Several protocols have been developed for generation of the most cell types of the respiratory system, which may be useful for deriving patient-specific therapeutic cells.[109][110][111][112][113]

Some lines of iPSCs have the potentiality to differentiate into male germ cells and oocyte-like cells in an appropriate niche (by culturing in retinoic acid and porcine follicular fluid differentiation medium or seminiferous tubule transplantation). Moreover, iPSC transplantation make a contribution to repairing the testis of infertile mice, demonstrating the potentiality of gamete derivation from iPSCs in vivo and in vitro.[114]

The risk of cancer and tumors creates the need to develop methods for safer cell lines suitable for clinical use. An alternative approach is so-called "direct reprogramming" - transdifferentiation of cells without passing through the pluripotent state.[115][116][117][118][119][120] The basis for this approach was that 5-azacytidine - a DNA demethylation reagent - can cause the formation of myogenic, chondrogenic and adipogeni clones in the immortal cell line of mouse embryonic fibroblasts[121] and that the activation of a single gene, later named MyoD1, is sufficient for such reprogramming.[122] Compared with iPSC whose reprogramming requires at least two weeks, the formation of induced progenitor cells sometimes occurs within a few days and the efficiency of reprogramming is usually many times higher. This reprogramming does not always require cell division.[123] The cells resulting from such reprogramming are more suitable for cell therapy because they do not form teratomas.[120] For example, Chandrakanthan et al., & Pimanda describe the generation of tissue-regenerative multipotent stem cells (iMS cells) by treating mature bone and fat cells transiently with a growth factor (platelet-derived growth factorAB (PDGF-AB)) and 5-Azacytidine. These authors claim that: "Unlike primary mesenchymal stem cells, which are used with little objective evidence in clinical practice to promote tissue repair, iMS cells contribute directly to in vivo tissue regeneration in a context-dependent manner without forming tumors" and so "has significant scope for application in tissue regeneration."[124][125][126]

Originally only early embryonic cells could be coaxed into changing their identity. Mature cells are resistant to changing their identity once they've committed to a specific kind. However, brief expression of a single transcription factor, the ELT-7 GATA factor, can convert the identity of fully differentiated, specialized non-endodermal cells of the pharynx into fully differentiated intestinal cells in intact larvae and adult roundworm Caenorhabditis elegans with no requirement for a dedifferentiated intermediate.[127]

The cell fate can be effectively manipulated by epigenome editing. In particular, by directly activating of specific endogenous gene expression with CRISPR-mediated activator. When dCas9 (that has been modified so that it no longer cuts DNA, but still can be guided to specific sequences and to bind to them) is combined with transcription activators, it can precisely manipulate endogenous gene expression. Using this method, Wei et al., enhanced the expression of endogenous Cdx2 and Gata6 genes by CRISPR-mediated activators, thus directly converted mouse embryonic stem cells into two extraembryonic lineages, i.e., typical trophoblast stem cells and extraembryonic endoderm cells.[128] An analogous approach was used to induce activation of the endogenous Brn2, Ascl1, and Myt1l genes to convert mouse embryonic fibroblasts to induced neuronal cells.[129] Thus, transcriptional activation and epigenetic remodeling of endogenous master transcription factors are sufficient for conversion between cell types. The rapid and sustained activation of endogenous genes in their native chromatin context by this approach may facilitate reprogramming with transient methods that avoid genomic integration and provides a new strategy for overcoming epigenetic barriers to cell fate specification.

Another way of reprogramming is the simulation of the processes that occur during amphibian limb regeneration. In urodele amphibians, an early step in limb regeneration is skeletal muscle fiber dedifferentiation into a cellulate that proliferates into limb tissue. However, sequential small molecule treatment of the muscle fiber with myoseverin, reversine (the aurora B kinase inhibitor) and some other chemicals: BIO (glycogen synthase-3 kinase inhibitor), lysophosphatidic acid (pleiotropic activator of G-protein-coupled receptors), SB203580 (p38 MAP kinase inhibitor), or SQ22536 (adenylyl cyclase inhibitor) causes the formation of new muscle cell types as well as other cell types such as precursors to fat, bone and nervous system cells.[130]

The researchers discovered that GCSF-mimicking antibody can activate a growth-stimulating receptor on marrow cells in a way that induces marrow stem cells that normally develop into white blood cells to become neural progenitor cells. The technique[131] enables researchers to search large libraries of antibodies and quickly select the ones with a desired biological effect.[132]

Schlegel and Liu[133] demonstrated that the combination of feeder cells[134][135][136] and a Rho kinase inhibitor (Y-27632) [137][138] induces normal and tumor epithelial cells from many tissues to proliferate indefinitely in vitro. This process occurs without the need for transduction of exogenous viral or cellular genes. These cells have been termed "Conditionally Reprogrammed Cells (CRC)". The induction of CRCs is rapid and results from reprogramming of the entire cell population. CRCs do not express high levels of proteins characteristic of iPSCs or embryonic stem cells (ESCs) (e.g., Sox2, Oct4, Nanog, or Klf4). This induction of CRCs is reversible and removal of Y-27632 and feeders allows the cells to differentiate normally.[133][139][140] CRC technology can generate 2106 cells in 5 to 6 days from needle biopsies and can generate cultures from cryopreserved tissue and from fewer than four viable cells. CRCs retain a normal karyotype and remain nontumorigenic. This technique also efficiently establishes cell cultures from human and rodent tumors.[133][141][142]

The ability to rapidly generate many tumor cells from small biopsy specimens and frozen tissue provides significant opportunities for cell-based diagnostics and therapeutics (including chemosensitivity testing) and greatly expands the value of biobanking.[133][141][142] Using CRC technology, researchers were able to identify an effective therapy for a patient with a rare type of lung tumor.[143] Engleman's group[144] describes a pharmacogenomic platform that facilitates rapid discovery of drug combinations that can overcome resistance using CRC system. In addition, the CRC method allows for the genetic manipulation of epithelial cells ex vivo and their subsequent evaluation in vivo in the same host. While initial studies revealed that co-culturing epithelial cells with Swiss 3T3 cells J2 was essential for CRC induction, with transwell culture plates, physical contact between feeders and epithelial cells is not required for inducing CRCs and more importantly that irradiation of the feeder cells is required for this induction. Consistent with the transwell experiments, conditioned medium induces and maintains CRCs, which is accompanied by a concomitant increase of cellular telomerase activity. The activity of the conditioned medium correlates directly with radiation-induced feeder cell apoptosis. Thus, conditional reprogramming of epithelial cells is mediated by a combination of Y-27632 and a soluble factor(s) released by apoptotic feeder cells.[145]

Riegel et al.[146] demonstrate that mouse ME cells isolated from normal mammary glands or from mouse mammary tumor virus (MMTV)-Neuinduced mammary tumors, can be cultured indefinitely as conditionally reprogrammed cells (CRCs). Cell surface progenitor-associated markers are rapidly induced in normal mouse ME-CRCs relative to ME cells. However, the expression of certain mammary progenitor subpopulations, such as CD49f+ ESA+ CD44+, drops significantly in later passages. Nevertheless, mouse ME-CRCs grown in a three-dimensional extracellular matrix gave rise to mammary acinar structures. ME-CRCs isolated from MMTV-Neu transgenic mouse mammary tumors express high levels of HER2/neu, as well as tumor-initiating cell markers, such as CD44+, CD49f+ and ESA+ (EpCam). These patterns of expression are sustained in later CRC passages. Early and late passage ME-CRCs from MMTV-Neu tumors that were implanted in the mammary fat pads of syngeneic or nude mice developed vascular tumors that metastasized within 6 weeks of transplantation. Importantly, the histopathology of these tumors was indistinguishable from that of the parental tumors that develop in the MMTV-Neu mice. Application of the CRC system to mouse mammary epithelial cells provides an attractive model system to study the genetics and phenotype of normal and transformed mouse epithelium in a defined culture environment and in vivo transplant studies.

A different approach to CRC is to inhibit CD47a membrane protein that is the thrombospondin-1 receptor. Loss of CD47 permits sustained proliferation of primary murine endothelial cells, increases asymmetric division and enables these cells to spontaneously reprogram to form multipotent embryoid body-like clusters. CD47 knockdown acutely increases mRNA levels of c-Myc and other stem cell transcription factors in cells in vitro and in vivo. Thrombospondin-1 is a key environmental signal that inhibits stem cell self-renewal via CD47. Thus, CD47 antagonists enable cell self-renewal and reprogramming by overcoming negative regulation of c-Myc and other stem cell transcription factors.[147] In vivo blockade of CD47 using an antisense morpholino increases survival of mice exposed to lethal total body irradiation due to increased proliferative capacity of bone marrow-derived cells and radioprotection of radiosensitive gastrointestinal tissues.[148]

Differentiated macrophages can self-renew in tissues and expand long-term in culture.[27] Under certain conditions macrophages can divide without losing features they have acquired while specializing into immune cells - which is usually not possible with differentiated cells. The macrophages achieve this by activating a gene network similar to one found in embryonic stem cells. Single-cell analysis revealed that, in vivo, proliferating macrophages can derepress a macrophage-specific enhancer repertoire associated with a gene network controlling self-renewal. This happened when concentrations of two transcription factors named MafB and c-Maf were naturally low or were inhibited for a short time. Genetic manipulations that turned off MafB and c-Maf in the macrophages caused the cells to start a self-renewal program. The similar network also controls embryonic stem cell self-renewal but is associated with distinct embryonic stem cell-specific enhancers.[28]

Hence macrophages isolated from MafB- and c-Maf-double deficient mice divide indefinitely; the self-renewal depends on c-Myc and Klf4.[149]

Indirect lineage conversion is a reprogramming methodology in which somatic cells transition through a plastic intermediate state of partially reprogrammed cells (pre-iPSC), induced by brief exposure to reprogramming factors, followed by differentiation in a specially developed chemical environment (artificial niche).[150]

This method could be both more efficient and safer, since it does not seem to produce tumors or other undesirable genetic changes and results in much greater yield than other methods. However, the safety of these cells remains questionable. Since lineage conversion from pre-iPSC relies on the use of iPSC reprogramming conditions, a fraction of the cells could acquire pluripotent properties if they do not stop the de-differentation process in vitro or due to further de-differentiation in vivo.[151]

A common feature of pluripotent stem cells is the specific nature of protein glycosylation of their outer membrane. That distinguishes them from most nonpluripotent cells, although not white blood cells.[152] The glycans on the stem cell surface respond rapidly to alterations in cellular state and signaling and are therefore ideal for identifying even minor changes in cell populations. Many stem cell markers are based on cell surface glycan epitopes including the widely used markers SSEA-3, SSEA-4, Tra 1-60 and Tra 1-81.[153] Suila Heli et al.[154] speculate that in human stem cells extracellular O-GlcNAc and extracellular O-LacNAc, play a crucial role in the fine tuning of Notch signaling pathway - a highly conserved cell signaling system, that regulates cell fate specification, differentiation, leftright asymmetry, apoptosis, somitogenesis, angiogenesis and plays a key role in stem cell proliferation (reviewed by Perdigoto and Bardin[155] and Jafar-Nejad et al.[156])

Changes in outer membrane protein glycosylation are markers of cell states connected in some way with pluripotency and differentiation.[157] The glycosylation change is apparently not just the result of the initialization of gene expression, but perform as an important gene regulator involved in the acquisition and maintenance of the undifferentiated state.[158]

For example, activation of glycoprotein ACA,[159] linking glycosylphosphatidylinositol on the surface of the progenitor cells in human peripheral blood, induces increased expression of genes Wnt, Notch-1, BMI1 and HOXB4 through a signaling cascade PI3K/Akt/mTor/PTEN and promotes the formation of a self-renewing population of hematopoietic stem cells.[160]

Furthermore, dedifferentiation of progenitor cells induced by ACA-dependent signaling pathway leads to ACA-induced pluripotent stem cells, capable of differentiating in vitro into cells of all three germ layers.[161] The study of lectins' ability to maintain a culture of pluripotent human stem cells has led to the discovery of lectin Erythrina crista-galli (ECA), which can serve as a simple and highly effective matrix for the cultivation of human pluripotent stem cells.[162]

Cell adhesion protein E-cadherin is indispensable for a robust pluripotent phenotype.[163] During reprogramming for iPS cell generation, N-cadherin can replace function of E-cadherin.[164] These functions of cadherins are not directly related to adhesion because sphere morphology helps maintaining the "stemness" of stem cells.[165] Moreover, sphere formation, due to forced growth of cells on a low attachment surface, sometimes induces reprogramming. For example, neural progenitor cells can be generated from fibroblasts directly through a physical approach without introducing exogenous reprogramming factors.

Physical cues, in the form of parallel microgrooves on the surface of cell-adhesive substrates, can replace the effects of small-molecule epigenetic modifiers and significantly improve reprogramming efficiency. The mechanism relies on the mechanomodulation of the cells' epigenetic state. Specifically, "decreased histone deacetylase activity and upregulation of the expression of WD repeat domain 5 (WDR5)a subunit of H3 methyltranferaseby microgrooved surfaces lead to increased histone H3 acetylation and methylation". Nanofibrous scaffolds with aligned fibre orientation produce effects similar to those produced by microgrooves, suggesting that changes in cell morphology may be responsible for modulation of the epigenetic state.[166]

Substrate rigidity is an important biophysical cue influencing neural induction and subtype specification. For example, soft substrates promote neuroepithelial conversion while inhibiting neural crest differentiation of hESCs in a BMP4-dependent manner. Mechanistic studies revealed a multi-targeted mechanotransductive process involving mechanosensitive Smad phosphorylation and nucleocytoplasmic shuttling, regulated by rigidity-dependent Hippo/YAP activities and actomyosin cytoskeleton integrity and contractility.[167]

Mouse embryonic stem cells (mESCs) undergo self-renewal in the presence of the cytokine leukemia inhibitory factor (LIF). Following LIF withdrawal, mESCs differentiate, accompanied by an increase in cellsubstratum adhesion and cell spreading. Restricted cell spreading in the absence of LIF by either culturing mESCs on chemically defined, weakly adhesive biosubstrates, or by manipulating the cytoskeleton allowed the cells to remain in an undifferentiated and pluripotent state. The effect of restricted cell spreading on mESC self-renewal is not mediated by increased intercellular adhesion, as inhibition of mESC adhesion using a function blocking anti E-cadherin antibody or siRNA does not promote differentiation.[168] Possible mechanisms of stem cell fate predetermination by physical interactions with the extracellular matrix have been described.[169][170]

A new method has been developed that turns cells into stem cells faster and more efficiently by 'squeezing' them using 3D microenvironment stiffness and density of the surrounding gel. The technique can be applied to a large number of cells to produce stem cells for medical purposes on an industrial scale.[171][172]

Cells involved in the reprogramming process change morphologically as the process proceeds. This results in physical difference in adhesive forces among cells. Substantial differences in 'adhesive signature' between pluripotent stem cells, partially reprogrammed cells, differentiated progeny and somatic cells allowed to develop separation process for isolation of pluripotent stem cells in microfluidic devices,[173] which is:

Stem cells possess mechanical memory (they remember past physical signals)with the Hippo signaling pathway factors:[174] Yes-associated protein (YAP) and transcriptional coactivator with PDZ-binding domain (TAZ) acting as an intracellular mechanical rheostatthat stores information from past physical environments and influences the cells' fate.[175][176]

Stroke and many neurodegenerative disorders such as Parkinson's disease, Alzheimer's disease, amyotrophic lateral sclerosis need cell replacement therapy. The successful use of converted neural cells (cNs) in transplantations open a new avenue to treat such diseases.[177] Nevertheless, induced neurons (iNs), directly converted from fibroblasts are terminally committed and exhibit very limited proliferative ability that may not provide enough autologous donor cells for transplantation.[178] Self-renewing induced neural stem cells (iNSCs) provide additional advantages over iNs for both basic research and clinical applications.[118][119][120][179][180]

For example, under specific growth conditions, mouse fibroblasts can be reprogrammed with a single factor, Sox2, to form iNSCs that self-renew in culture and after transplantation can survive and integrate without forming tumors in mouse brains.[181] INSCs can be derived from adult human fibroblasts by non-viral techniques, thus offering a safe method for autologous transplantation or for the development of cell-based disease models.[180]

Neural chemically induced progenitor cells (ciNPCs) can be generated from mouse tail-tip fibroblasts and human urinary somatic cells without introducing exogenous factors, but - by a chemical cocktail, namely VCR (V, VPA, an inhibitor of HDACs; C, CHIR99021, an inhibitor of GSK-3 kinases and R, RepSox, an inhibitor of TGF beta signaling pathways), under a physiological hypoxic condition.[182] Alternative cocktails with inhibitors of histone deacetylation, glycogen synthase kinase and TGF- pathways (where: sodium butyrate (NaB) or Trichostatin A (TSA) could replace VPA, Lithium chloride (LiCl) or lithium carbonate (Li2CO3) could substitute CHIR99021, or Repsox may be replaced with SB-431542 or Tranilast) show similar efficacies for ciNPC induction.[182] Zhang, et al.,[183] also report highly efficient reprogramming of mouse fibroblasts into induced neural stem cell-like cells (ciNSLCs) using a cocktail of nine components.

Multiple methods of direct transformation of somatic cells into induced neural stem cells have been described.[184]

Proof of principle experiments demonstrate that it is possible to convert transplanted human fibroblasts and human astrocytes directly in the brain that are engineered to express inducible forms of neural reprogramming genes, into neurons, when reprogramming genes (Ascl1, Brn2a and Myt1l) are activated after transplantation using a drug.[185]

Astrocytesthe most common neuroglial brain cells, which contribute to scar formation in response to injurycan be directly reprogrammed in vivo to become functional neurons that formed networks in mice without the need of cell transplantation.[186] The researchers followed the mice for nearly a year to look for signs of tumor formation and reported finding none. The same researchers have turned scar-forming astrocytes into progenitor cells called neuroblasts that regenerated into neurons in the injured adult spinal cord.[187]

Without myelin to insulate neurons, nerve signals quickly lose power. Diseases that attack myelin, such as multiple sclerosis, result in nerve signals that cannot propagate to nerve endings and as a consequence lead to cognitive, motor and sensory problems. Transplantation of oligodendrocyte precursor cells (OPCs), which can successfully create myelin sheaths around nerve cells, is a promising potential therapeutic response. Direct lineage conversion of mouse and rat fibroblasts into oligodendroglial cells provides a potential source of OPCs. Conversion by forced expression of both eight[188] or of the three[189] transcription factors Sox10, Olig2 and Zfp536, may provide such cells.

Cell-based in vivo therapies may provide a transformative approach to augment vascular and muscle growth and to prevent non-contractile scar formation by delivering transcription factors[115] or microRNAs[14] to the heart.[190] Cardiac fibroblasts, which represent 50% of the cells in the mammalian heart, can be reprogrammed into cardiomyocyte-like cells in vivo by local delivery of cardiac core transcription factors ( GATA4, MEF2C, TBX5 and for improved reprogramming plus ESRRG, MESP1, Myocardin and ZFPM2) after coronary ligation.[115][191] These results implicated therapies that can directly remuscularize the heart without cell transplantation. However, the efficiency of such reprogramming turned out to be very low and the phenotype of received cardiomyocyte-like cells does not resemble those of a mature normal cardiomyocyte. Furthermore, transplantation of cardiac transcription factors into injured murine hearts resulted in poor cell survival and minimal expression of cardiac genes.[192]

Meanwhile, advances in the methods of obtaining cardiac myocytes in vitro occurred.[193][194] Efficient cardiac differentiation of human iPS cells gave rise to progenitors that were retained within infarcted rat hearts and reduced remodeling of the heart after ischemic damage.[195]

The team of scientists, who were led by Sheng Ding, used a cocktail of nine chemicals (9C) for transdifferentiation of human skin cells into beating heart cells. With this method, more than 97% of the cells began beating, a characteristic of fully developed, healthy heart cells. The chemically induced cardiomyocyte-like cells (ciCMs) uniformly contracted and resembled human cardiomyocytes in their transcriptome, epigenetic, and electrophysiological properties. When transplanted into infarcted mouse hearts, 9C-treated fibroblasts were efficiently converted to ciCMs and developed into healthy-looking heart muscle cells within the organ.[196] This chemical reprogramming approach, after further optimization, may offer an easy way to provide the cues that induce heart muscle to regenerate locally.[197]

In another study, ischemic cardiomyopathy in the murine infarction model was targeted by iPS cell transplantation. It synchronized failing ventricles, offering a regenerative strategy to achieve resynchronization and protection from decompensation by dint of improved left ventricular conduction and contractility, reduced scarring and reversal of structural remodelling.[198] One protocol generated populations of up to 98% cardiomyocytes from hPSCs simply by modulating the canonical Wnt signaling pathway at defined time points in during differentiation, using readily accessible small molecule compounds.[199]

Discovery of the mechanisms controlling the formation of cardiomyocytes led to the development of the drug ITD-1, which effectively clears the cell surface from TGF- receptor type II and selectively inhibits intracellular TGF- signaling. It thus selectively enhances the differentiation of uncommitted mesoderm to cardiomyocytes, but not to vascular smooth muscle and endothelial cells.[200]

One project seeded decellularized mouse hearts with human iPSC-derived multipotential cardiovascular progenitor cells. The introduced cells migrated, proliferated and differentiated in situ into cardiomyocytes, smooth muscle cells and endothelial cells to reconstruct the hearts. In addition, the heart's extracellular matrix (the substrate of heart scaffold) signalled the human cells into becoming the specialised cells needed for proper heart function. After 20 days of perfusion with growth factors, the engineered heart tissues started to beat again and were responsive to drugs.[201]

Reprogramming of cardiac fibroblasts into induced cardiomyocyte-like cells (iCMs) in situ represents a promising strategy for cardiac regeneration. Mice exposed in vivo, to three cardiac transcription factors GMT (Gata4, Mef2c, Tbx5) and the small-molecules: SB-431542 (the transforming growth factor (TGF)- inhibitor), and XAV939 (the WNT inhibitor) for 2 weeks after myocardial infarction showed significantly improved reprogramming (reprogramming efficiency increased eight-fold) and cardiac function compared to those exposed to only GMT.[202]

See also: review[203]

The elderly often suffer from progressive muscle weakness and regenerative failure owing in part to elevated activity of the p38 and p38 mitogen-activated kinase pathway in senescent skeletal muscle stem cells. Subjecting such stem cells to transient inhibition of p38 and p38 in conjunction with culture on soft hydrogel substrates rapidly expands and rejuvenates them that result in the return of their strength.[204]

In geriatric mice, resting satellite cells lose reversible quiescence by switching to an irreversible pre-senescence state, caused by derepression of p16INK4a (also called Cdkn2a). On injury, these cells fail to activate and expand, even in a youthful environment. p16INK4a silencing in geriatric satellite cells restores quiescence and muscle regenerative functions.[205]

Myogenic progenitors for potential use in disease modeling or cell-based therapies targeting skeletal muscle could also be generated directly from induced pluripotent stem cells using free-floating spherical culture (EZ spheres) in a culture medium supplemented with high concentrations (100ng/ml) of fibroblast growth factor-2 (FGF-2) and epidermal growth factor.[206]

Unlike current protocols for deriving hepatocytes from human fibroblasts, Saiyong Zhu et al., (2014)[207] did not generate iPSCs but, using small molecules, cut short reprogramming to pluripotency to generate an induced multipotent progenitor cell (iMPC) state from which endoderm progenitor cells and subsequently hepatocytes (iMPC-Heps) were efficiently differentiated. After transplantation into an immune-deficient mouse model of human liver failure, iMPC-Heps proliferated extensively and acquired levels of hepatocyte function similar to those of human primary adult hepatocytes. iMPC-Heps did not form tumours, most probably because they never entered a pluripotent state.

These results establish the feasibility of significant liver repopulation of mice with human hepatocytes generated in vitro, which removes a long-standing roadblock on the path to autologous liver cell therapy.

Cocktail of small molecules, Y-27632, A-83-01 (a TGF kinase/activin receptor like kinase (ALK5) inhibitor), and CHIR99021 (potent inhibitor of GSK-3), can convert rat and mouse mature hepatocytes in vitro into proliferative bipotent cells - CLiPs (chemically induced liver progenitors). CLiPs can differentiate into both mature hepatocytes and biliary epithelial cells that can form functional ductal structures. In long-term culture CLiPs did not lose their proliferative capacity and their hepatic differentiation ability, and can repopulate chronically injured liver tissue.[208]

Complications of Diabetes mellitus such as cardiovascular diseases, retinopathy, neuropathy, nephropathy and peripheral circulatory diseases depend on sugar dysregulation due to lack of insulin from pancreatic beta cells and can be lethal if they are not treated. One of the promising approaches to understand and cure diabetes is to use pluripotent stem cells (PSCs), including embryonic stem cells (ESCs) and induced PCSs (iPSCs).[209] Unfortunately, human PSC-derived insulin-expressing cells resemble human fetal cells rather than adult cells. In contrast to adult cells, fetal cells seem functionally immature, as indicated by increased basal glucose secretion and lack of glucose stimulation and confirmed by RNA-seq of whose transcripts.[210]

An alternative strategy is the conversion of fibroblasts towards distinct endodermal progenitor cell populations and, using cocktails of signalling factors, successful differentiation of these endodermal progenitor cells into functional beta-like cells both in vitro and in vivo.[211]

Overexpression of the three transcription factors, PDX1 (required for pancreatic bud outgrowth and beta-cell maturation), NGN3 (required for endocrine precursor cell formation) and MAFA (for beta-cell maturation) combination (called PNM) can lead to the transformation of some cell types into a beta cell-like state.[212] An accessible and abundant source of functional insulin-producing cells is intestine. PMN expression in human intestinal "organoids" stimulates the conversion of intestinal epithelial cells into -like cells possibly acceptable for transplantation.[213]

Adult proximal tubule cells were directly transcriptionally reprogrammed to nephron progenitors of the embryonic kidney, using a pool of six genes of instructive transcription factors (SIX1, SIX2, OSR1, Eyes absent homolog 1(EYA1), Homeobox A11 (HOXA11) and Snail homolog 2 (SNAI2)) that activated genes consistent with a cap mesenchyme/nephron progenitor phenotype in the adult proximal tubule cell line.[214] The generation of such cells may lead to cellular therapies for adult renal disease. Embryonic kidney organoids placed into adult rat kidneys can undergo onward development and vascular development.[215]

As blood vessels age, they often become abnormal in structure and function, thereby contributing to numerous age-associated diseases including myocardial infarction, ischemic stroke and atherosclerosis of arteries supplying the heart, brain and lower extremities. So, an important goal is to stimulate vascular growth for the collateral circulation to prevent the exacerbation of these diseases. Induced Vascular Progenitor Cells (iVPCs) are useful for cell-based therapy designed to stimulate coronary collateral growth. They were generated by partially reprogramming endothelial cells.[150] The vascular commitment of iVPCs is related to the epigenetic memory of endothelial cells, which engenders them as cellular components of growing blood vessels. That is why, when iVPCs were implanted into myocardium, they engrafted in blood vessels and increased coronary collateral flow better than iPSCs, mesenchymal stem cells, or native endothelial cells.[216]

Ex vivo genetic modification can be an effective strategy to enhance stem cell function. For example, cellular therapy employing genetic modification with Pim-1 kinase (a downstream effector of Akt, which positively regulates neovasculogenesis) of bone marrowderived cells[217] or human cardiac progenitor cells, isolated from failing myocardium[218] results in durability of repair, together with the improvement of functional parameters of myocardial hemodynamic performance.

Stem cells extracted from fat tissue after liposuction may be coaxed into becoming progenitor smooth muscle cells (iPVSMCs) found in arteries and veins.[219]

The 2D culture system of human iPS cells[220] in conjunction with triple marker selection (CD34 (a surface glycophosphoprotein expressed on developmentally early embryonic fibroblasts), NP1 (receptor - neuropilin 1) and KDR (kinase insert domain-containing receptor)) for the isolation of vasculogenic precursor cells from human iPSC, generated endothelial cells that, after transplantation, formed stable, functional mouse blood vessels in vivo, lasting for 280 days.[221]

To treat infarction, it is important to prevent the formation of fibrotic scar tissue. This can be achieved in vivo by transient application of paracrine factors that redirect native heart progenitor stem cell contributions from scar tissue to cardiovascular tissue. For example, in a mouse myocardial infarction model, a single intramyocardial injection of human vascular endothelial growth factor A mRNA (VEGF-A modRNA), modified to escape the body's normal defense system, results in long-term improvement of heart function due to mobilization and redirection of epicardial progenitor cells toward cardiovascular cell types.[222]

RBC transfusion is necessary for many patients. However, to date the supply of RBCs remains labile. In addition, transfusion risks infectious disease transmission. A large supply of safe RBCs generated in vitro would help to address this issue. Ex vivo erythroid cell generation may provide alternative transfusion products to meet present and future clinical requirements.[223][224] Red blood cells (RBC)s generated in vitro from mobilized CD34 positive cells have normal survival when transfused into an autologous recipient.[225] RBC produced in vitro contained exclusively fetal hemoglobin (HbF), which rescues the functionality of these RBCs. In vivo the switch of fetal to adult hemoglobin was observed after infusion of nucleated erythroid precursors derived from iPSCs.[226] Although RBCs do not have nuclei and therefore can not form a tumor, their immediate erythroblasts precursors have nuclei. The terminal maturation of erythroblasts into functional RBCs requires a complex remodeling process that ends with extrusion of the nucleus and the formation of an enucleated RBC.[227] Cell reprogramming often disrupts enucleation. Transfusion of in vitro-generated RBCs or erythroblasts does not sufficiently protect against tumor formation.

The aryl hydrocarbon receptor (AhR) pathway (which has been shown to be involved in the promotion of cancer cell development) plays an important role in normal blood cell development. AhR activation in human hematopoietic progenitor cells (HPs) drives an unprecedented expansion of HPs, megakaryocyte- and erythroid-lineage cells.[228] See also Concise Review:[229][230] The SH2B3 gene encodes a negative regulator of cytokine signaling and naturally occurring loss-of-function variants in this gene increase RBC counts in vivo. Targeted suppression of SH2B3 in primary human hematopoietic stem and progenitor cells enhanced the maturation and overall yield of in-vitro-derived RBCs. Moreover, inactivation of SH2B3 by CRISPR/Cas9 genome editing in human pluripotent stem cells allowed enhanced erythroid cell expansion with preserved differentiation.[231] (See also overview.[230][232])

Platelets help prevent hemorrhage in thrombocytopenic patients and patients with thrombocythemia. A significant problem for multitransfused patients is refractoriness to platelet transfusions. Thus, the ability to generate platelet products ex vivo and platelet products lacking HLA antigens in serum-free media would have clinical value. An RNA interference-based mechanism used a lentiviral vector to express short-hairpin RNAi targeting 2-microglobulin transcripts in CD34-positive cells. Generated platelets demonstrated an 85% reduction in class I HLA antigens. These platelets appeared to have normal function in vitro[233]

One clinically-applicable strategy for the derivation of functional platelets from human iPSC involves the establishment of stable immortalized megakaryocyte progenitor cell lines (imMKCLs) through doxycycline-dependent overexpression of BMI1 and BCL-XL. The resulting imMKCLs can be expanded in culture over extended periods (45 months), even after cryopreservation. Halting the overexpression (by the removal of doxycycline from the medium) of c-MYC, BMI1 and BCL-XL in growing imMKCLs led to the production of CD42b+ platelets with functionality comparable to that of native platelets on the basis of a range of assays in vitro and in vivo.[234] Thomas et al., describe a forward programming strategy relying on the concurrent exogenous expression of 3 transcription factors: GATA1, FLI1 and TAL1. The forward programmed megakaryocytes proliferate and differentiate in culture for several months with megakaryocyte purity over 90% reaching up to 2x105 mature megakaryocytes per input hPSC. Functional platelets are generated throughout the culture allowing the prospective collection of several transfusion units from as few as one million starting hPSCs.[235] See also overview[236]

A specialised type of white blood cell, known as cytotoxic T lymphocytes (CTLs), are produced by the immune system and are able to recognise specific markers on the surface of various infectious or tumour cells, causing them to launch an attack to kill the harmful cells. Thence, immunotherapy with functional antigen-specific T cells has potential as a therapeutic strategy for combating many cancers and viral infections.[237] However, cell sources are limited, because they are produced in small numbers naturally and have a short lifespan.

A potentially efficient approach for generating antigen-specific CTLs is to revert mature immune T cells into iPSCs, which possess indefinite proliferative capacity in vitro and after their multiplication to coax them to redifferentiate back into T cells.[238][239][240]

Another method combines iPSC and chimeric antigen receptor (CAR)[241] technologies to generate human T cells targeted to CD19, an antigen expressed by malignant B cells, in tissue culture.[242] This approach of generating therapeutic human T cells may be useful for cancer immunotherapy and other medical applications.

Invariant natural killer T (iNKT) cells have great clinical potential as adjuvants for cancer immunotherapy. iNKT cells act as innate T lymphocytes and serve as a bridge between the innate and acquired immune systems. They augment anti-tumor responses by producing interferon-gamma (IFN-).[243] The approach of collection, reprogramming/dedifferentiation, re-differentiation and injection has been proposed for related tumor treatment.[244]

Dendritic cells (DC) are specialized to control T-cell responses. DC with appropriate genetic modifications may survive long enough to stimulate antigen-specific CTL and after that be completely eliminated. DC-like antigen-presenting cells obtained from human induced pluripotent stem cells can serve as a source for vaccination therapy.[245]

CCAAT/enhancer binding protein- (C/EBP) induces transdifferentiation of B cells into macrophages at high efficiencies[246] and enhances reprogramming into iPS cells when co-expressed with transcription factors Oct4, Sox2, Klf4 and Myc.[247] with a 100-fold increase in iPS cell reprogramming efficiency, involving 95% of the population.[248] Furthermore, C/EBPa can convert selected human B cell lymphoma and leukemia cell lines into macrophage-like cells at high efficiencies, impairing the cells' tumor-forming capacity.[249]

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Cardiac Stem Cells Comments Off on Induced stem cells – Wikipedia | November 28th, 2016

An isolated cardiac muscle cell, beating

Cardiac muscle (heart muscle) is an involuntary, striated muscle that is found in the walls and histological foundation of the heart, specifically the myocardium. Cardiac muscle is one of three major types of muscle, the others being skeletal and smooth muscle. These three types of muscle all form in the process of myogenesis. The cells that constitute cardiac muscle, called cardiomyocytes or myocardiocytes, predominantly contain only one nucleus, although populations with two to four nuclei do exist.[1][2][pageneeded] The myocardium is the muscle tissue of the heart, and forms a thick middle layer between the outer epicardium layer and the inner endocardium layer.

Coordinated contractions of cardiac muscle cells in the heart pump blood out of the atria and ventricles to the blood vessels of the left/body/systemic and right/lungs/pulmonary circulatory systems. This complex mechanism illustrates systole of the heart.

Cardiac muscle cells, unlike most other tissues in the body, rely on an available blood and electrical supply to deliver oxygen and nutrients and remove waste products such as carbon dioxide. The coronary arteries help fulfill this function.

Cardiac muscle has cross striations formed by rotating segments of thick and thin protein filaments. Like skeletal muscle, the primary structural proteins of cardiac muscle are myosin and actin. The actin filaments are thin, causing the lighter appearance of the I bands in striated muscle, whereas the myosin filament is thicker, lending a darker appearance to the alternating A bands as observed with electron microscopy. However, in contrast to skeletal muscle, cardiac muscle cells are typically branch-like instead of linear.

Another histological difference between cardiac muscle and skeletal muscle is that the T-tubules in the cardiac muscle are bigger and wider and track laterally to the Z-discs. There are fewer T-tubules in comparison with skeletal muscle. The diad is a structure in the cardiac myocyte located at the sarcomere Z-line. It is composed of a single T-tubule paired with a terminal cisterna of the sarcoplasmic reticulum. The diad plays an important role in excitation-contraction coupling by juxtaposing an inlet for the action potential near a source of Ca2+ ions. This way, the wave of depolarization can be coupled to calcium-mediated cardiac muscle contraction via the sliding filament mechanism. Cardiac muscle forms these instead of the triads formed between the sarcoplasmic reticulum in skeletal muscle and T-tubules. T-tubules play critical role in excitation-contraction coupling (ECC). Recently, the action potentials of T-tubules were recorded optically by Guixue Bu et al.[3]

The cardiac syncytium is a network of cardiomyocytes connected to each other by intercalated discs that enable the rapid transmission of electrical impulses through the network, enabling the syncytium to act in a coordinated contraction of the myocardium. There is an atrial syncytium and a ventricular syncytium that are connected by cardiac connection fibres.[4] Electrical resistance through intercalated discs is very low, thus allowing free diffusion of ions. The ease of ion movement along cardiac muscle fibers axes is such that action potentials are able to travel from one cardiac muscle cell to the next, facing only slight resistance. Each syncytium obeys the all or none law.[5]

Intercalated discs are complex adhering structures that connect the single cardiomyocytes to an electrochemical syncytium (in contrast to the skeletal muscle, which becomes a multicellular syncytium during mammalian embryonic development). The discs are responsible mainly for force transmission during muscle contraction. Intercalated discs consist of three different types of cell-cell junctions: the actin filament anchoring adherens junctions, the intermediate filament anchoring desmosomes , and gap junctions. They allow action potentials to spread between cardiac cells by permitting the passage of ions between cells, producing depolarization of the heart muscle. However, novel molecular biological and comprehensive studies unequivocally showed that intercalated discs consist for the most part of mixed-type adhering junctions named area composita (pl. areae compositae) representing an amalgamation of typical desmosomal and fascia adhaerens proteins (in contrast to various epithelia).[6][7][8] The authors discuss the high importance of these findings for the understanding of inherited cardiomyopathies (such as arrhythmogenic right ventricular cardiomyopathy).

Under light microscopy, intercalated discs appear as thin, typically dark-staining lines dividing adjacent cardiac muscle cells. The intercalated discs run perpendicular to the direction of muscle fibers. Under electron microscopy, an intercalated disc's path appears more complex. At low magnification, this may appear as a convoluted electron dense structure overlying the location of the obscured Z-line. At high magnification, the intercalated disc's path appears even more convoluted, with both longitudinal and transverse areas appearing in longitudinal section.[9]

In contrast to skeletal muscle, cardiac muscle requires extracellular calcium ions for contraction to occur. Like skeletal muscle, the initiation and upshoot of the action potential in ventricular cardiomyocytes is derived from the entry of sodium ions across the sarcolemma in a regenerative process. However, an inward flux of extracellular calcium ions through L-type calcium channels sustains the depolarization of cardiac muscle cells for a longer duration. The reason for the calcium dependence is due to the mechanism of calcium-induced calcium release (CICR) from the sarcoplasmic reticulum that must occur during normal excitation-contraction (EC) coupling to cause contraction. Once the intracellular concentration of calcium increases, calcium ions bind to the protein troponin, which allows myosin to bind to actin and contraction to occur.

Until recently, it was commonly believed that cardiac muscle cells could not be regenerated. However, a study reported in the April 3, 2009 issue of Science contradicts that belief.[10] Olaf Bergmann and his colleagues at the Karolinska Institute in Stockholm tested samples of heart muscle from people born before 1955 who had very little cardiac muscle around their heart, many showing with disabilities from this abnormality. By using DNA samples from many hearts, the researchers estimated that a 4-year-old renews about 20% of heart muscle cells per year, and about 69 percent of the heart muscle cells of a 50-year-old were generated after he or she was born.

One way that cardiomyocyte regeneration occurs is through the division of pre-existing cardiomyocytes during the normal aging process.[11] The division process of pre-existing cardiomyocytes has also been shown to increase in areas adjacent to sites of myocardial injury. In addition, certain growth factors promote the self-renewal of endogenous cardiomyocytes and cardiac stem cells. For example, insulin-like growth factor 1, hepatocyte growth factor, and high-mobility group protein B1 increase cardiac stem cell migration to the affected area, as well as the proliferation and survival of these cells.[12] Some members of the fibroblast growth factor family also induce cell-cycle re-entry of small cardiomyocytes. Vascular endothelial growth factor also plays an important role in the recruitment of native cardiac cells to an infarct site in addition to its angiogenic effect.

Based on the natural role of stem cells in cardiomyocyte regeneration, researchers and clinicians are increasingly interested in using these cells to induce regeneration of damaged tissue. Various stem cell lineages have been shown to be able to differentiate into cardiomyocytes, including bone marrow stem cells. For example, in one study, researchers transplanted bone marrow cells, which included a population of stem cells, adjacent to an infarct site in a mouse model. Nine days after surgery, the researchers found a new band of regenerating myocardium.[13] However, this regeneration was not observed when the injected population of cells was devoid of stem cells, which strongly suggests that it was the stem cell population that contributed to the myocardium regeneration. Other clinical trials have shown that autologous bone marrow cell transplants delivered via the infarct-related artery decreases the infarct area compared to patients not given the cell therapy.[14]

Occlusion (blockage) of the coronary arteries by atherosclerosis and/or thrombosis can lead to myocardial infarction (heart attack), where part of the myocardium is injured due to ischemia (not receiving enough oxygen). This occurs because coronary arteries are functional end arteries - i.e. there is almost no overlap in the areas supplied by different arteries (anastomoses) so that if one fails, others cannot adequately perfuse the region, unlike in other tissues.

Certain viruses lead to myocarditis (inflammation of the myocardium). Cardiomyopathies are inherent diseases of the myocardium, many of which are caused by genetic mutations.

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Cardiac muscle - Wikipedia

Cardiac Stem Cells Comments Off on Cardiac muscle – Wikipedia | November 27th, 2016