Progress in repairing Hearts
Scientists have turned back the hands of a biological clock to rejuvenate ageing and damaged human heart cells. Using stem cells, they reset a molecular mechanism that determines the rate at which cells age. Although the work on human cells was confined to the laboratory, the same technique has been successfully tested in mice and pigs.Researchers in the US managed to get new heart tissue to grow in the animals in just four weeks. They hope the advance will lead to new treatments for heart failure.
“Modifying aged human cardiac cells from elderly patients adds to the cell’s ability to regenerate damaged heart muscle, making stem cell engineering a viable option,” said lead scientist Dr Sadia Mohsin, from San Diego State University in California.
In the laboratory studies, Dr Mohsin’s team worked on heart tissue surgically removed from elderly patients. Stem cells from the samples were treated with a growth protein called PIM-1.
The effect was to boost activity of an enzyme called telomerase, which has a direct impact on ageing. The research was presented at a meeting of the American Heart Association in New Orleans and published in the Journal of the American College of Cardiology.
Optimistic – We are!
The Sunday Times has reported the following information reference fixing damaged hearts. It goes to show that research and more interestingly practical steps are being made on stem cell development for injured hearts.
American researchers believe that artificial hearts developed in laboratories could start beating within weeks. The experiment is a major step towards the first ‘grow-your-own’ heart. The organs were created by removing muscle cells from donor organs to leave behind tough hearts of connective tissue. Researchers then injected stem cells which multiplied and grew around the structure, eventually turning into healthy heart cells. Dr Doris Taylor, an expert in regenerative medicine at the University of Minnesota in Minneapolis, said: ‘The hearts are growing, and we hope they will show signs of beating within the next few weeks.” ‘There are many hurdles to overcome to generate a fully functioning heart, but my prediction is that it may one day be possible to grow entire organs for transplant.’
Patients given normal heart transplants must take drugs to suppress their immune systems for the rest of their lives.
This can increase the risk of high blood pressure, kidney failure and diabetes.
If new hearts could be made using a patient’s own stem cells, it is less likely they would be rejected.
So how are they doing it…
The lab-grown organs have been created using these types of cells – the body’s immature ‘master cells’ which have the ability to turn into different types of tissue. The experiment follows a string of successes for researchers trying to create spare body parts for transplants.
In 2007, British doctors grew a human heart valve using stem cells taken from a patient’s bone marrow
Grow your own heart
- The donor heart is removed from the body; pig hearts may also be suitable as they are very similair to humans.
- Detergents are then used to strip the cells from the heart leaving behind the protein skeleton or ‘ghost heart’.
- Stem cells grown from cells taken from a patient are then added to the ghost heart.
- The stem cells then multiply and generate new heart cells. now all that is left is the hope that these will start beating.
A year later, scientists grew a beating animal heart for the first time.
Dr Taylor’s team have already created beating rat and pig hearts. Although they were too weak to be used in animals, the work was an important step towards tailor-made organs. In their latest study, reported at the American College of Cardiology’s annual conference in New Orleans, researchers created new organs using human hearts taken from dead bodies. The scientists stripped the cells from the dead hearts with a powerful detergent, leaving ‘ghost heart’ scaffolds made from the protein collagen.
The ghost hearts were then injected with millions of stem cells, which had been extracted from patients and supplied with nutrients. The stem cells ‘recognised’ the collagen heart structure and began to turn into heart muscle cells. The hearts have yet to start beating – but if they do, they could be strong enough to pump blood.
However, the race to create a working heart faces many obstacles. One of the biggest is getting enough oxygen to the organ through a complex network of blood vessels. Scientists also need to ensure the heart cells beat in time. Dr Taylor indicated that: ‘We are a long way off creating a heart for transplant, but we think we’ve opened a door to building any organ for human transplant.’
We are of course will be following the developments carefully especially with the British Heart Foundations “Mending Broken Hearts Campaign” in aid of raising £50 million for research into mending broken hearts.