Human ES cell derived cardiomyocytes for cell replacement therapy: a current update.

Cardiovascular diseases are the leading cause of death globally. The pluripotency and indefinite proliferative capacity of embryonic stem (ES) cells make them a promising candidate for the cell replacement therapy where the damaged cells are replaced by the functional cells derived from stem cells in vitro. Emerging results with human ES cells for the myocardial repair are encouraging, but this approach is still in its infancy and is under extensive investigation. The daily upcoming experimental observations are reinforcing the solid hope that ES cells will be the potential source for use in cell replacement therapy. Although this demands serious considerations ethically and on practical applicability, the newly upcoming discoveries show that the adult human fibroblasts can be reprogrammed to embryonic stem cell like cells (called induced pluripotent stem cells) which can be used for cell replacement therapies. Remarkably, this obviates the need for the embryo destruction and overcomes related immunological problems which are the long time hurdles for the ES cell based cell replacement therapy. This review weighs the actual stand off in the human ES cells based cell replacement therapy for the treatment of cardiovascular degenerative diseases with a special emphasis on the hurdles and challenges to be resolved before the onset of clinical trials and the potential of the recently reported "induced pluripotent stem cells" for their use in cell replacement therapy.