Is heart regeneration on the right track?

Myocardial infarction can cause irreversible heart muscle cell damage and lingering cardiac problems that can eventually lead to heart failure. For over a decade, researchers have been trying to coax stem cells to differentiate into cardiomyocytes to repair damaged heart tissue, with limited success. In 'Bedside to Bench', Christine L. Mummery and Richard T. Lee lay out a framework for re-evaluating cardiac cell therapies in the context of two recent clinical trials, in which autologous cardiac stem cells derived from heart biopsies were transferred into patients, with promising, albeit difficult to interpret, results. Results from previous clinical trials using autologous bone marrow–derived adult stem cells to induce cardiac regeneration add to the debate about how to cautiously move forward in the cardiac regeneration field and to the questions that need to be urgently answered at the bench. In 'Bench to Bedside', Young-Jae Nam, Kunhua Song and Eric N. Olson discuss a number of recent studies in rodents showing that cardiac fibroblasts can be reprogrammed, via miRNAs and a transcription factor 'cocktail', to express cardiac genes, which resulted in improved cardiac function in the animals, suggesting a new way forward for fixing damaged heart tissue.