诱导多能干细胞分化的心肌细胞电生理特点.

BACKGROUND: Transplantation therapy after the directional differentiation of induced pluripotent stem cells can solve the immune elimination and ethical problems, and directional differentiation of induced pluripotent stem cells into cardiomyocytes provides the possibility of cardiomyocyte regeneration research. OBJECTIVE: To detect the electrophysiological function of cardiomyocytes differentiated from induced pluripotent stem cells. METHODS: By culturing induced pluripotent stem cells in vitro, direct suspension culture and differentiation medium were used to induce induced pluripotent stem cells to form embryoid bodies. Cell growth was observed and formation time, number and contraction rate of cardiomyocytes were recorded. The electrophysiological characteristics of cardiomyocytes were detected by Axon Axopatch 200B single probe ultra-low noise patch clamp amplifier and MED64 multi-electrode array system. The responsiveness of differentiated cardiomyocytes to isoproterenol was observed. Cardiac troponin T expression levels in differentiated cardiomyocytes were detected by immunofluorescence. RESULTS AND CONCLUSION: (1) The growth characteristics of induced pluripotent stem cells were similar to embryonic stem cells, resembling a bird’s nest and growing like a colony. (2) In the differentiation medium culture, induced pluripotent stem cells aggregated to form embryoid bodies of different sizes after 5 days of suspension culture. During the adherent growth of embryoid bodies, up to 10% of the colonies appeared beating cardiomyocytes, and the beating rate on the 20th and 25th days was significantly higher than other time points (P < 0.05). (3) Action potentials of ventricular, atrial and sinoatrial nodular cells were observed in induced pluripotent stem cells differentiated cardiomyocytes. (4) Isoproterenol could increase the spontaneous beat frequency of cardiomyocytes differentiated from induced pluripotent stem cells. (5) Cellular immunofluorescence indicated that cardiomyocytes differentiated from induced pluripotent stem cells were positive for cardiac troponin T. (6) The results confirm that cardiomyocytes differentiated from induced pluripotent stem cells have sinoatrial-like, atrial-like and ventricular-like action potentials, and have adrenaline signal transduction. [ABSTRACT FROM AUTHOR]