Requirement of IP3 receptor 3 (IP(3)R3) in nitric oxide induced cardiomyocyte differentiation of mouse embryonic stem cells

Nitric oxide (NO) markedly induces cardiomyocyte (CM) differentiation of embryonic stem (ES) cells. Here we examined the role of the Ca2+ signaling in the NO-induced CM differentiation of mouse ES cells. We found that NO induced intracellular Ca2+ increases in ES cells in a dose-dependent manner, and application of IP3 pathway antagonists not only significantly inhibited this induced Ca2+ increase but also abolished NO-induced CM differentiation of ES cells. Subsequently, all 3 types of inositol 1, 4, 5-trisphosphate (IP3) receptors (IP(3)Rs) in mouse ES cells were individually or triply knocked down. Interestingly, only knockdown of type 3 IP3R (IP(3)R3) or triple-knockdown of three types of IP(3)Rs significantly inhibited the NO-induced Ca2+ increases. Consistently, IP(3)R3 knockdown blocked the NO-induced CM differentiation of ES cells. CMs derived from IP(3)R3 knockdown ES cells also showed both structural and functional defects. In summary, our results indicate that the IP(3)R3-Ca2+ pathway is required for NO-induced CM differentiation of ES cells. (C) 2016 Elsevier Inc. All rights reserved.;Nitric oxide (NO) markedly induces cardiomyocyte (CM) differentiation of embryonic stem (ES) cells. Here we examined the role of the Ca2+ signaling in the NO-induced CM differentiation of mouse ES cells. We found that NO induced intracellular Ca2+ increases in ES cells in a dose-dependent manner, and application of IP3 pathway antagonists not only significantly inhibited this induced Ca2+ increase but also abolished NO-induced CM differentiation of ES cells. Subsequently, all 3 types of inositol 1, 4, 5-trisphosphate (IP3) receptors (IP(3)Rs) in mouse ES cells were individually or triply knocked down. Interestingly, only knockdown of type 3 IP3R (IP(3)R3) or triple-knockdown of three types of IP(3)Rs significantly inhibited the NO-induced Ca2+ increases. Consistently, IP(3)R3 knockdown blocked the NO-induced CM differentiation of ES cells. CMs derived from IP(3)R3 knockdown ES cells also showed both structural and functional defects. In summary, our results indicate that the IP(3)R3-Ca2+ pathway is required for NO-induced CM differentiation of ES cells. (C) 2016 Elsevier Inc. All rights reserved.