As part of a series of seminars, Dasman Diabetes Institute recently held a talk titled “Testosterone Enhances Cardiomyogenesis in Stem Cells and Recruits the Androgen Receptor to the MEF2C and HCN4 Genes”, presented by Dr. Ashraf Al Madhoun, Scientist / Team Leader, Pancreatic Islet Biology & Transplantation Unit at the Institute.

Testosterone is the male sex hormone that is critical for the development of the male sex characteristics. Testosterone mediates its action by binding to Androgen receptor. The presence of the androgen receptor in both sexes and its distribution in a wide variety of human organs including heart, skeletal muscles and thymus, promotes scientists to study the functional role of the hormone in these tissues. Studies have shown that testosterone enhances the formation of beating cardiomyocytes from stem cells, which is a critical step in field regenerative medicine for the treatment of heart defects. However the mechanism of this process has not been elucidated.

In the current issue of the Journal of Molecular and Cellular Cardiology, Dr. Ashraf Al Madhoun and his colleagues discovered the precise cellular and molecular mechanism by which testosterone mediates the enrichment of cardiomyocytes from stem cells. Testosterone improves the recruitment of androgen receptor to the regulatory regions of the myocyte enhancer factor-2C (MEF2C) and hyperpolarization-activated cyclic nucleotide-gated channel 4 (HCN4) genes, which induce cardiomyogenesis in stem cell. Interestingly, testosterone also stimulates Ca2+ channels and testosterone-induced cardiomyogenesis requires extracellular Ca2+ influx. These discoveries will help scientists to improve the use of stem cells for heart repair and healing.