Damaged heart could be coaxed into mending itself

A broken heart could soon be coaxed into mending itself, says an Indian-origin scientist who led an international team which claims to have discovered a way of converting ordinary tissue into beating muscle cells.

Prof Deepak Srivastava of the Gladstone Institute at California University and his colleagues say the revolutionary treatment of repairing damage caused by cardiac arrests or old age would be available in just five years.

The technique works in a similar way to stem cells but instead of the new cells being grown outside the body and then injected back in, the method simply makes the cells switch at the point where they are needed, say the scientists.

The main problem is that when beating muscles cells -- known as cardiomyocytes -- die during an attack there's no way to reactivate them and the surrounding connective tissue -- known as fibroblasts -- cannot take over their role.

But, Prof Srivastava and his team have developed a way of reprogramming fibroblasts into cardiomyocytes. The system involves slowly administering three substances -- using an artificial tube called a stent -- into the blood that trigger the conversion, 'The Daily Telegraph' reported.

Professor Srivastava believes this could be achieved over just two weeks. "We first have to test if the same factors can convert human fibroblasts to beating heart muscle and then find ways to safely introduce these factors, or small molecules that mimic these factors, into the coronary circulation so they can reprogramme the existing fibroblasts in the heart," he said.

"I envision such factors being loaded into a stent that is placed in the coronary artery and can elute (allow to emerge) the reprogramming factors over 1-2 weeks. It is ambitious, but not unreasonable, to imagine being ready for a clinical trial in the next five years," he said.

In their research, the team found that they needed a combination of just three substance Gata4, Mef2c, and Tbx5 to efficiently convert fibroblasts into cells that could beat like cardiomyocytes.

One day after the three factors were introduced into mouse hearts, fibroblasts turned into cardiomyocyte-like cells within the beating heart. Up to 20 per cent made the switch.

"The ability to reprogramme fibroblasts into cardiomyocytes has many therapeutic implications. Half of the cells in the heart are fibroblasts, so the ability to call upon this reservoir of cells already in the organ to become beating heart cells has tremendous promise for cardiac regeneration," Srivastava wrote in 'Cell' journal.