A team of American scientists led by Doctor Edward Morrisey (University of Pennsylvania, Philadelphia) has highlighted the possibility of regenerating cardiac muscle cells post-infarction in mice. Current attempts to repair the heart involve surgery or a heart transplant. Tests have also been carried out with the injection of embryo stem cells.
The technique discovered involves two microRNA injections “capable of specifically inhibiting two key elements” in cell mechanics “preventing the proliferation of cardiomyocytes in adults”. Scientists have observed the regeneration of cardiac muscle tissue in mice without any adverse effect on other organs. The American team will continue tests on animals such as pigs in order “to resemble human conditions more closely”. This new approach therefore constitutes an alternative to the use of embryo stem cells.
As far as Jean-Sébastien Silvestre, Inserm Research Director at the Cardiovascular Research Centre, Hôpital Européen Georges Pompidou in Paris is concerned, “this new strategy seems to be the Holy Grail of cardiac therapy, which is to regenerate the heart”. He nevertheless remains measured, “The capacity to regenerate a heart damaged by years of smoking or diabetes is probably not the same as regenerating a healthy murine heart”.
 microRNAs are genome-coded molecules that regulate gene expression.