Small Peptide Could Heal Broken Hearts

A broken heart may one day be able to mend itself with the help of a small peptide that prods undifferentiated heart cells to morph into new heart muscle, according to a report in Nature (DOI: 10.1038/nature10188). Heart attacks currently lead to permanent heart damage, but the discovery by Paul R. Riley of University College London and colleagues sets the stage for scientists to develop a treatment that could enable hearts to produce new cardiomyocytes and self-repair the damage. Riley’s team worked with a peptide called thymosin β4 that had previously been shown to help outer-layer heart cells cope with injury. The researchers found that thymosin β4 induced outer-layer progenitor cells in mice to differentiate into cardiomyocytes that could “structurally and functionally integrate with resident muscle.” The putative peptide drug is unlikely to land in the clinic, however, unless scientists can get it to produce greater quantities of cardiomyocytes, they note.