Electrically Induced Calcium Handling in Cardiac Progenitor Cells.

For nearly a century, the heart was viewed as a terminally differentiated organ until the discovery of a resident population of cardiac stem cells known as cardiac progenitor cells (CPCs). It has been shown that the regenerative capacity of CPCs can be enhanced by ex vivo modification. Preconditioning CPCs could provide drastic improvements in cardiac structure and function; however, a systematic approach to determining a mechanistic basis for these modifications founded on the physiology of CPCs is lacking. We have identified a novel property of CPCs to respond to electrical stimulation by initiating intracellular Ca ²⁺ oscillations. We used confocal microscopy and intracellular calcium imaging to determine the spatiotemporal properties of the Ca ²⁺ signal and the key proteins involved in this process using pharmacological inhibition and confocal Ca ²⁺ imaging. Our results provide valuable insights into mechanisms to enhance the therapeutic potential in stem cells and further our understanding of human CPC physiology.