How stem cell research could help repair heart attack damage

Chances are you’ve heard of stem cells. Even if you haven’t, you’ll know of Dolly the cloned sheep – the original ‘poster girl’ of this sensational field of scientific research.

Dolly’s creation in 1996 saw scientists accused of ‘playing God’, but while stem cell research does raise ethical questions, it may also hold the key to mending hearts damaged by a heart attack and has many other potential uses.

It’s an amazing breakthrough

Professor Chris Denning

Two professors at the cutting edge of stem cell research tell us how their work could affect people’s lives in the future.

“In the past, we couldn’t have conceived of these studies,” says Chris Denning, Professor of Stem Cell Biology at the University of Nottingham. “But what was once impossible is now possible.”

He’s referring to induced pluripotent stem (iPS) cells. Their development won Shinya Yamanaka and John Gurdon the Nobel Prize for Physiology or Medicine in 2012. But what are iPS cells, and why is this type of research such a big deal?

iPS cells explained

Until recently, to conduct stem cell research scientists needed to obtain human embryonic stem cells from spare IVF embryos with the consent of those involved. These embryonic cells could be coaxed into becoming any human body cell.

Today, you can simply take a skin biopsy or a blood sample from a patient, isolate skin or blood cells and, by adding four genes, convince them that they are stem cells.

“The gene cocktail used can differ, but the most common factors are called the Yamanaka factors, after Shinya Yamanaka, and are all stem cell-related genes,” explains Professor Denning. The beauty of the iPS cell technique lies in its simplicity.

“Everybody thought he [Yamanaka] was crazy when he presented iPS cells at one big international conference. Within a year several labs had repeated the technique. Yamanaka was a superstar; the Japanese government invested £65.1m in him. Just six years later, he won the Nobel Prize.”

Patient in a dish

By adding specific growth factors, you can turn iPS cells into beating heart cells in a dish. This means it’s possible to study people with heart conditions without conducting invasive procedures.

“Imagine you have an inherited heart condition,” says Professor Denning (pictured right). “I say: ‘I would like to investigate it using some of your heart cells, so I need to crack your chest open and cut out a little piece of your heart. But because the cells only last a few weeks in the lab, can I come back the next week and do the same again?’ It’s not going to happen.

“Now, I can take a skin biopsy, do the genetic programming that turns it into stem cells and keep growing them. We’re still working with the same population of cells we reprogrammed in 2008 and all we took was a skin biopsy the size of a matchstick head.”

Professor Denning uses iPS cells to research inherited conditions that lead to sudden death. “When patients with this condition get stressed or experience strange stimuli, they can start to experience terrible arrhythmias,” he explains.

“What we’re able to do in a lab is mimic the person’s condition in a culture dish. This is because the cells retain the genetic abnormalities present in those who donated the skin biopsy.”

New drug therapies to regenerate dead cells?

‘Patients in a dish’ could also help create new drugs. “If you’re a person with a condition and someone says they want to test 1,000 different drugs in you, you would say ‘I think not’ – some of them might be harmful,” says Professor Denning. “But if you can replicate these things, you can ask if those drugs work when tested in a dish.”

He says what makes this cutting-edge work worthwhile is seeing the impact it might have on people’s lives. “Once in a while, you have a little bit of a breakthrough, but I have to say that the thing that made me happiest was when we published our 2011 paper. Our clinical colleagues forwarded it on to a patient’s family and the father replied to thank us for the work we’re doing in this area. That is why we’re doing it.”

When someone suffers a heart attack, cells in the heart are starved of oxygen and die. This can lead to the chronic and life-limiting condition heart failure, for which there’s currently no cure.

We don’t know how to mend or regenerate dead cells, but stem cell research could unlock new ways of doing precisely that.

We fund three pioneering Centres of Regenerative Medicine led by Imperial College London and the Universities of Edinburgh and Oxford, working with other top UK universities to study how to regrow, repair or replace damaged or diseased hearts and blood vessels.

Professor Sian Harding’s team, from the Centre led by Imperial College London, has developed a 3D stem cell patch that can ‘beat’. The patches are designed to be attached to a damaged heart, physically supporting the damaged heart muscle and helping it pump more efficiently, while also releasing natural chemicals that stimulate the heart cells to repair and regenerate. Eventually, the aim is that the heart would incorporate the patch. Early studies have shown the patches are safe in animals and the team are now planning safety trials in humans.

Thanks to BHF research and the people who support us, there is real hope that stem cells can be used to repair the damaged heart in future.