Direct cell conversion to cardiomyocytes

A method for converting mouse fibroblasts into spontaneously contracting cardiac cells using factors conventionally used for reprogramming differentiated cells to a pluripotent state is reported online in Nature Cell Biology this week. The strategy may represent an alternative, and potentially quicker, way of obtaining cells that can be used to study potential heart dysfunctions in the laboratory.

To understand the basis of cardiac-related syndromes, stem cells researchers have devoted significant effort to obtaining contractile heart muscle cells, known as cardiomyocytes, from sources of cells easily isolated from patients, such as skin cells. Given that the mammalian heart lacks significant regenerative capacity, such strategies could be eventually used for transplantation.

After briefly expressing factors that usually revert cell fate to an undifferentiated state in mouse fibroblasts, Sheng Ding and colleagues placed the cells in chemically defined growth solution containing molecules favourable to cardiogenic development. They found that rather than reprogramming to a pluripotent state, cells were tweaked towards heart lineage and form spontaneously contracting patches of differentiated cardiomyocytes. By avoiding the need to revert cells to a fully pluripotent state before re-differentiating them to cardiomyocytes, this strategy could provide a shortcut in the obtention of cells that could be used to study heart dysfunctions in a dish.