Type 3 inositol 1,4,5-trisphosphate receptor negatively regulates apoptosis during mouse embryonic stem cell differentiation

Abstract

Ca 2 þ signals generated by inositol 1,4,5-trisphosphate receptors (IP 3 Rs) are crucial for cellular processes such as apoptosis and differentiation. However, the exact roles of IP 3 Rs and their contributions to Ca 2 þ signals in pluripotent embryonic stem (ES) cell behaviors remain largely unknown. In this study, we showed that the expression of type 3 IP 3 R (IP 3 R3) was transiently downregulated with a concomitant increase in apoptosis at the early differentiation stage of murine ES cells. Knockdown of IP 3 R3 by small interfering RNA increased apoptosis in differentiating cells but not in undifferentiated ES cells. Moreover, IP 3 R3 overexpression had the opposite effect. Consistently, IP 3 R3 knockdown altered Ca 2 þ oscillations in differentiating cells but not in undifferentiated ES cells. The apoptosis in differentiating IP 3 R3-knockdown cells was decreased by chelating intracellular Ca 2 þ with BAPTA-AM and increased in control ones. Furthermore, IP 3 R3 knockdown led to a suppression of the expression of mesodermal and mesoendodermal but not ectodermal markers. The differentiation suppressions were further confirmed by the impaired differentiation of mesodermal and some of the endodermal but not ectodermal derivatives. Such defects were partially because of the increased apoptosis in Flk-1 þ cells. These findings provide the first demonstration of the important role of IP 3 R3 in the regulation of apoptosis in early differentiating ES cells and subsequent lineage commitments through modulation of Ca 2 þ signals.

Expression profiles of histone lysine demethylases during cardiomyocyte differentiation of mouse embryonic stem cells

“…Interestingly, we found that all of these genes are constitutively upregulated during cardiac differentiation ( Figure 2A, Table 4). This expression pattern is similar to the expression patterns of genes related to the cardiac lineage decision, such as Flk-1, Nkx2.5, Mef2c, and cardiac specific marker Ncx1, as found in our previous [40,41] and present data ( Figure 1C), suggesting that these KDMs may be involved in lineage determination.…”

Ascorbic acid enhances the cardiac differentiation of induced pluripotent stem cells through promoting the proliferation of cardiac progenitor cells

“…Immunoblot analyses were performed according to the protocol described previously [45]. Protein samples were size fractionated www.cell-research.com | Cell Research Nan Cao et al 235 npg by SDS-polyacrylamide gel electrophoresis and the separated proteins were electrophoretically transferred to polyvinylindene difluoride membranes (Bio-Rad, Hercules, CA, USA).…”

Involvement of Rictor/mTORC2 in cardiomyocyte differentiation of mouse embryonic stem cells in vitro

“…mTORC2 could promote post-natal heart growth and maintain heart function in mice by synergistically interacting with PDK1 35. It is known that spontaneous apoptosis occured during the process of differentiation 36. mTORC2 was proved to be associated with apoptosis in osteosarcoma cell and breast cancer 37, 38.…”