Functional BKCa channel in human resident cardiac stem cells expressing W8B2.
Recently, a new population of resident cardiac stem cells (CSCs) positive for the W8B2 marker has been identified. These CSCs are considered to be an ideal cellular source to repair myocardial damage after infarction. However, the electrophysiological profile of these cells has not been characterized yet. We first establish the conditions of isolation and expansion of W8B2+ CSCs from human heart biopsies using a magnetic sorting system followed by flow cytometry cell sorting. These cells display a spindle-shaped morphology, are highly proliferative, and possess self-renewal capacity demonstrated by their ability to form colonies. Besides, W8B2+ CSCs are positive for mesenchymal markers but negative for hematopoietic and endothelial ones. RT-qPCR and immunostaining experiments show that W8B2+ CSCs express some early cardiac-specific transcription factors but lack the expression of cardiac-specific structural genes. Using patch clamp in the whole-cell configuration, we show for the first time the electrophysiological signature of BKCa current in these cells. Accordingly, RT-PCR and western blotting analysis confirmed the presence of BKCa at both mRNA and protein levels in W8B2+ CSCs. Interestingly, BKCa channel inhibition by paxilline decreased cell proliferation in a concentration-dependent manner and halted cell cycle progression at the G0/G1 phase. The inhibition of BKCa also decreased the self-renewal capacity but did not affect migration of W8B2+ CSCs. Taken together, our results are consistent with an important role of BKCa channels in cell cycle progression and self-renewal in human cardiac stem cells.
['Ayad|Oualid|O|', 'Magaud|Christophe|C|', 'Sebille|Stéphane|S|', 'Bescond|Jocelyn|J|', 'Mimbimi|Chloé|C|', 'Cognard|Christian|C|', 'Faivre|Jean-Francois|JF|', 'Bois|Patrick|P|', 'Chatelier|Aurelien|A|']
D000954:Antigens, Surface D015415:Biomarkers D002121:Calcium Channel Blockers D002465:Cell Movement D049109:Cell Proliferation D000066673:Cell Self Renewal D002469:Cell Separation D048430:Cell Shape D002478:Cells, Cultured D005434:Flow Cytometry D006801:Humans D018189:Immunomagnetic Separation D007211:Indoles D051037:Large-Conductance Calcium-Activated Potassium Channel alpha Subunits D008863:Microspheres D032383:Myocytes, Cardiac D018408:Patch-Clamp Techniques D012333:RNA, Messenger D016192:Resting Phase, Cell Cycle D013234:Stem Cells
BKCa W8B2+ self-renewal proliferation migration