Category Archives: Stem Cells

4:49pm, Fri 16 Aug 2013 - last updated Fri 16 Aug 2013 Repairing damaged hearts in rats through stem cell treatment could work for human hearts as well. Photo:

You've had a heart attack. You're wheeled into A&E on a gurney. You survive, but your heart muscle is damaged. It's called heart failure - your heart just doesn't pump properly. Your long-term prospects look none too good.

All that could change if experiments on rats at Kings College on London are shown to hold for human beings too. After a heart attack, you would get an injection of heart stem cells - cells that can repair the damage to your heart muscles.

The stem cells would "home in" on your heart and grow into new muscle - triggering the stem cells already in your heart to leap onto action.

Sounds like science fiction, but Georgina Ellison, one of the Kings College researchers, told me it could be part of regular clinical practice within the next decade.

Everyone has stem cells in their hearts. Their job is to repair the normal wear and tear on your heart muscles by growing into new muscle cells. Trouble is, as you get older, the stem cells don't work as well. So if you have a heart problem like a heart attack or coronary artery disease, the stem cells can't cope.

Rats have heart stem cells too. When the researchers at Kings destroyed the rats' stem cells, they developed heart failure. When they put the stem cells back in, the failed hearts were restored to proper function. The implication for humans is obvious.

But even better you don't have to inject the stem cells directly into the heart for them to work. In humans that would be quite a serious procedure. Instead, the researchers simply injected the stem cells into a vein and they found their own way to the heart and started the repair process.

So if the same technique works in humans, a simple injection could treat heart failure - and might be able to prevent heart failure developing.

There's only one way of finding out if the technique works for us as well as for rats and that's to try it. So researchers in Spain and Belgium will start human trials of the technique early next year. If they're successful, stem cells could be used to treat heart failure before the end of the decade.

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Behaviour of stem cells in rats could help to treat heart failure

Stem cells have recently appeared in the press for being able to treat cancer, and as a recent study by UK scientists reveals, they might also be able to help repair hearts ravaged by cardiac disease.

When a heart is damaged, it cannot often repair the cells or make news ones. However, the new study shows that re-injected stem cells naturally home in on damaged regions of the heart to repair them.

The discovery could lead to less invasive treatments for heart failure, or early prevention of the condition that affects more than 750,000 Britons.

Heart failure occurs when the heart is too weak to pump blood around the body efficiently, leading to breathlessness, fatigue, and disability.

A leading cause of the condition is heart attacks, but it can also be triggered by genetic defects.

The new research set out to investigate the role of cardiac stem cells by removing them from rodents with heart failure.

Without the stem cells, the animals' hearts were unable to regenerate and recover.

Linoleic acid is essential to keep your heart healthy, so try to consume between two to four teaspoons a day.

Tomatoes are great for brightening the skin but more importantly, the food also acts as a blood purifier. It also contains lots of Vitamin K, which helps to prevent hemorrhages.

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Stem Cells Could Revolutionise Healing Heart Disease

Javascript is currently disabled in your web browser. For full site functionality, it is necessary to enable Javascript. In order to enable it, please see these instructions. 5 hours ago Previously, stem cells were thought to be organized in a strict hierarchy. In contrast, the new results show that the skin contains specialized stem cells holding a primary function, with the potential to change function if a need arises. This is illustrated in the figure, where the early stem cells were stained with a red protein a year before the pictures were taken. It shows that the stem cells maintain specialized functions as the skin develops and either forms the hair follicle, the fat gland or the barrier protecting us against environmental challenges. Credit: Kim Jensen, University of Copenhagen

All organs in our body rely on stem cells in order to maintain their function. The skin is our largest organ and forms a shield against the environment. New research results from BRIC, University of Copenhagen and Cambridge University, challenge current stem cell models and explains how the skin is maintained throughout life. The results have just been published in the recognized journal Cell Stem Cell.

New knowledge challenge stem cell models

The skin consists of many different cell types, including hair cells, fat- and sweat glands. It protects us against microbial and chemical attacks and forms a waterproof barrier that prevents fluid loss. Associate professor Kim Jensen' group from BRIC have through mapping of stem cell's behaviour in the skin found out that the skin uses a unique method to renew itself. Their results challenge the current perception of how our skin is renewed.

"Until now, the belief was that the skin's stem cells were organized in a strict hierarchy with a primitive stem cell type at the top of the hierarchy, and that this cell gave rise to all other cell types of the skin. However, our results show that there are differentiated levels of stem cells and that it is their close micro-environment that determines whether they make hair follicles, fat- or sweat glands, says Kim Jensen.

The new research from Kim Jensen completes the stem cell puzzle.

"Our data completes what is already known about the skin and its maintenance. Researchers have until now tried to fit their results into the old model for skin maintenance.

However, the results give much more meaning when we relate them to the new model that our research proposes, says Kim Jensen.

One such example is that it explains the current mystery of how skin cells can divide too much and initiate a skin cancer, without any traces of genetic change in the stem cells believed to maintain the outer layer of the skin. The research from the Jensen group may suggest that the reason that no changes can be found is, that these cells do not take part in the over-proliferation at all.

New knowledge of skin cancer and wound healing

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Shining stem cells reveals how our skin is maintained

By Vignesh Ramachandran2013-08-15 20:20:34 UTC

Scientists in Pennsylvania have successfully transplanted human stem cells into a mouse's heart intentionally stripped of its own cells. The mouse heart began beating, showing the exciting potential for regenerative medicine.

The University of Pittsburgh School of Medicine said researchers first removed all the cells from the mouse's heart to prepare the heart as a "scaffold" on order to test regeneration. In technical terms, this process is called "decellularization." The researchers then repopulated the heart with human cells.

It took a few weeks for the mouse heart to rebuild, but in the end, the heart began contracting at 40 to 50 beats per minute, as explained in the video above. According to the Mayo Clinic, a normal resting heart rate for adults ranges from 60 to 100 beats per minute.

The university said it needs to do more work to make this type of regenerated heart "contract strongly enough to be able to pump blood effectively" and figure out how to make the heart correctly regulate its speed.

So, what does this mean for humans?

Heart disease is the leading cause of death in the United States and in the world. In fact, one person in the U.S. dies from heart disease every 34 seconds.

The Pittsburgh scientists say regenerative medicine could replace tissue for damage caused during a heart attack. Tissue engineering could also someday yield entire organs for patients.

One of our next goals is to see if its feasible to make a patch of human heart muscle, Lei Yang, an assistant professor of developmental biology at the Pitt School of Medicine, said in a news release. We could use patches to replace a region damaged by a heart attack. That might be easier to achieve because it wont require as many cells as a whole human-sized organ would.

The university said there is potential to take a skin biopsy from a patient in order to develop personalized, special cells that help regenerate a new organ. That replacement organ could someday be sustainable enough to transplant.

See the article here:
Human Stem Cells Revive Mouse's Cell-Stripped Heart

By Vignesh Ramachandran2013-08-15 20:20:34 UTC

Scientists in Pennsylvania have successfully transplanted human stem cells into a mouse's heart intentionally stripped of its own cells. The mouse heart began beating, showing the exciting potential for regenerative medicine.

The University of Pittsburgh School of Medicine said researchers first removed all the cells from the mouse's heart to prepare the heart as a "scaffold" on order to test regeneration. In technical terms, this process is called "decellularization." The researchers then repopulated the heart with human cells.

It took a few weeks for the mouse heart to rebuild, but in the end, the heart began contracting at 40 to 50 beats per minute, as explained in the video above. According to the Mayo Clinic, a normal resting heart rate for adults ranges from 60 to 100 beats per minute.

The university said it needs to do more work to make this type of regenerated heart "contract strongly enough to be able to pump blood effectively" and figure out how to make the heart correctly regulate its speed.

So, what does this mean for humans?

Heart disease is the leading cause of death in the United States and in the world. In fact, one person in the U.S. dies from heart disease every 34 seconds.

The Pittsburgh scientists say regenerative medicine could replace tissue for damage caused during a heart attack. Tissue engineering could also someday yield entire organs for patients.

One of our next goals is to see if its feasible to make a patch of human heart muscle, Lei Yang, an assistant professor of developmental biology at the Pitt School of Medicine, said in a news release. We could use patches to replace a region damaged by a heart attack. That might be easier to achieve because it wont require as many cells as a whole human-sized organ would.

The university said there is potential to take a skin biopsy from a patient in order to develop personalized, special cells that help regenerate a new organ. That replacement organ could someday be sustainable enough to transplant.

See the article here:
Human Stem Cells Revive Mouse's Cell-Stripped Heart

Scientists said Tuesday they had used stem cells to grow human heart tissue that contracted spontaneously in a petri dish -- marking progress in the quest to manufacture transplant organs.

A team from the University of Pittsburgh, Pennsylvania, used induced pluripotent stem (iPS) cells generated from human skin cells to create precursor heart cells called MCPs.

iPS cells are mature human cells "reprogrammed" into a versatile, primitive state from which they can be prompted to develop into any kind of cell of the body.

The primitive heart cells created in this way were attached to a mouse heart "scaffold" from which the researchers had removed all mouse heart cells, they wrote in the journal Nature Communications.

The scaffold is a network of non-living tissue composed of proteins and carbohydrates to which cells adhere and grow on.

Placed on the 3D scaffold, the precursor cells grew and developed into heart muscle, and after 20 days of blood supply the reconstructed mouse organ "began contracting again at the rate of 40 to 50 beats per minute," said a University of Pittsburgh statement.

"It is still far from making a whole human heart," added senior researcher Lei Yang.

Ways have to be found to make the heart contract strongly enough to pump blood effectively and to rebuild the heart's electrical conduction system.

"However, we provide a novel resource of cells -- iPS cell-derived MCPs -- for future heart tissue engineering," Yang told AFP by email.

"We hope our study would be used in the future to replace a piece of tissue damaged by a heart attack, or perhaps an entire organ, in patients with heart disease."

Read more:
Scientists use stem cells to grow human heart tissue

Public release date: 15-Aug-2013 [ | E-mail | Share ]

Contact: Katya Nasim katya.nasim@kcl.ac.uk 44-207-848-3840 King's College London

Researchers at King's College London have for the first time highlighted the natural regenerative capacity of a group of stem cells that reside in the heart. This new study shows that these cells are responsible for repairing and regenerating muscle tissue damaged by a heart attack which leads to heart failure.

The study, published today in the journal Cell, shows that if the stem cells are eliminated, the heart is unable to repair after damage. If the cardiac stem cells are replaced the heart repairs itself, leading to complete cellular, anatomical and functional heart recovery, with the heart returning to normal and pumping at a regular rate.

Also, if the cardiac stem cells are removed and re-injected, they naturally 'home' to and repair the damaged heart, a discovery that could lead to less-invasive treatments and even early prevention of heart failure in the future.

The study, funded by the European Commission Seventh Framework Programme (FP7), set out to establish the role of cardiac stem cells (eCSCs) by first removing the cells from the hearts of rodents with heart failure. This stopped regeneration and recovery of the heart, demonstrating the intrinsic regenerative capacity of these cells for repairing the heart in response to heart failure.

Heart failure when the heart is unable to pump blood around the body adequately affects more than 750,000 people in the UK, causing breathlessness and impeding daily activities. Current treatments are aimed at treating the underlying causes, such as coronary heart disease, heart attack and blood pressure through lifestyle changes, medicines and in severe cases, surgery. These treatments are sometimes successful in preventing or delaying heart failure. However, once heart failure develops the only curative treatment is heart transplantation.

By revealing this robust homing mechanism, which causes cardiac stem cells to home to and repair the heart's damaged muscle, the findings could lead to less invasive treatments or even preventative measures aimed at maintaining or increasing the activity of the heart's own cardiac stem cells.

Dr Georgina Ellison, the first author of the paper and Professor Bernardo Nadal-Ginard, the study's corresponding author, both from the Centre of Human & Aerospace Physiological Sciences and the Centre for Stem Cells and Regenerative Medicine at King's, said: 'In a healthy heart the quantity of cardiac stem cells is sufficient to repair muscle tissue in the heart. However, in damaged hearts many of these cells cannot multiply or produce new muscle tissue. In these cases it could be possible to replace the damaged cardiac stem cells or add new ones by growing them in the laboratory and administering them intravenously.'

Dr Ellison added: 'Understanding the role and potential of cardiac stems cells could pave the way for a variety of new ways to prevent and treat heart failure. These new approaches involve maintaining or increasing the activity of cardiac stem cells so that muscle tissue in the heart can be renewed with new heart cells, replacing old cells or those damaged by wear and tear.

Link:
Heart's own stem cells offer hope for new treatment of heart failure

Public release date: 15-Aug-2013 [ | E-mail | Share ]

Contact: Katya Nasim katya.nasim@kcl.ac.uk 44-207-848-3840 King's College London

Researchers at King's College London have for the first time highlighted the natural regenerative capacity of a group of stem cells that reside in the heart. This new study shows that these cells are responsible for repairing and regenerating muscle tissue damaged by a heart attack which leads to heart failure.

The study, published today in the journal Cell, shows that if the stem cells are eliminated, the heart is unable to repair after damage. If the cardiac stem cells are replaced the heart repairs itself, leading to complete cellular, anatomical and functional heart recovery, with the heart returning to normal and pumping at a regular rate.

Also, if the cardiac stem cells are removed and re-injected, they naturally 'home' to and repair the damaged heart, a discovery that could lead to less-invasive treatments and even early prevention of heart failure in the future.

The study, funded by the European Commission Seventh Framework Programme (FP7), set out to establish the role of cardiac stem cells (eCSCs) by first removing the cells from the hearts of rodents with heart failure. This stopped regeneration and recovery of the heart, demonstrating the intrinsic regenerative capacity of these cells for repairing the heart in response to heart failure.

Heart failure when the heart is unable to pump blood around the body adequately affects more than 750,000 people in the UK, causing breathlessness and impeding daily activities. Current treatments are aimed at treating the underlying causes, such as coronary heart disease, heart attack and blood pressure through lifestyle changes, medicines and in severe cases, surgery. These treatments are sometimes successful in preventing or delaying heart failure. However, once heart failure develops the only curative treatment is heart transplantation.

By revealing this robust homing mechanism, which causes cardiac stem cells to home to and repair the heart's damaged muscle, the findings could lead to less invasive treatments or even preventative measures aimed at maintaining or increasing the activity of the heart's own cardiac stem cells.

Dr Georgina Ellison, the first author of the paper and Professor Bernardo Nadal-Ginard, the study's corresponding author, both from the Centre of Human & Aerospace Physiological Sciences and the Centre for Stem Cells and Regenerative Medicine at King's, said: 'In a healthy heart the quantity of cardiac stem cells is sufficient to repair muscle tissue in the heart. However, in damaged hearts many of these cells cannot multiply or produce new muscle tissue. In these cases it could be possible to replace the damaged cardiac stem cells or add new ones by growing them in the laboratory and administering them intravenously.'

Dr Ellison added: 'Understanding the role and potential of cardiac stems cells could pave the way for a variety of new ways to prevent and treat heart failure. These new approaches involve maintaining or increasing the activity of cardiac stem cells so that muscle tissue in the heart can be renewed with new heart cells, replacing old cells or those damaged by wear and tear.

Link:
Heart's own stem cells offer hope for new treatment of heart failure

A newly beating heart is part-mouse, part-human. For the first time, a mouse heart has been made to pulse again by stripping it of its own cells and rebuilding it with human ones (see video above).

To create the hybrid heart, Lei Yang at the University of Pittsburgh and colleagues took the heart from a mouse and, in a process that lasted 10 hours, removed all its cells. The remaining protein scaffold was then repopulated with human heart precursor cells stem cells that had differentiated into the three types of cell required for a heart. After a few weeks, the organ started to beat again. "Our engineered hearts contain about 70 per cent human heart precursor cells, which provide enough mechanical force for contraction," says Yang.

The precursor cells were derived from induced pluripotent stem cells generated from human skin cells, and were then turned into cardiac precursor cells. A previous study used human embryonic cells to achieve similar results, but the success rate in converting them to beating heart cells was very low.

Although the designer hearts do beat rhythmically, they aren't strong enough to pump blood effectively and the team found that the heart's rhythm differed from a normal mouse's heart. Yang thinks this is because the added cells were not as mature as adult heart cells or properly synchronised. "We did not rebuild the whole cardiac conduction system, which could control the rhythmic beatings of a heart," he says. The team's next step will be to improve the mechanical and electrical synchronisation of the heartbeat.

The study builds on previous work by Yang and colleagues where human heart precursor cells, derived from embryonic stem cells, successfully differentiated into different heart cells when injected into a mouse heart. In another recent study, a rat's heart was bioengineered by seeding a scaffold with another rat's stem cells.

Yang's long-term goal is to create human hearts that can be used for transplants, for drug testing and to better understand how a heart develops. "Using our method, we could generate both muscle and vascular-like structures in the engineered heart constructs," says Yang. "We hope to make a piece of human heart tissue soon but our dream is to regenerate a human heart organ."

The main challenge is to scale up the system to work with human heart scaffolds. There, the biggest problem will be the sheer number of cells needed to reseed a human heart.

Journal reference: Nature Communications, DOI: 10.1038/ncomms3307

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Link:
Mouse heart beats again thanks to human stem cells