Fig. 6

Calcium chelator BAPTA-AM attenuates cardiomyocyte apoptosis and reduces endoplasmic reticulum stress. A AO staining showed that BAPTA-AM reduced apoptosis, however, apoptosis increased after inhibition of S1R. B Western blot showed that BAPTA-AM decreased apoptosis, while inhibition of S1R increased apoptosis. C The statistical analysis diagrams of apoptotic cell percentage (n = 3). D The statistical analysis diagrams of Bcl2, Bax protein level relative to GAPDH (n = 3). E The statistical analysis diagrams of immunofluorescence staining reflecting S1R expression (n = 3). F The statistical analysis diagrams of immunofluorescence staining reflecting S1R and IP3R expression (n = 3). G Immunofluorescence showed that the endoplasmic reticulum was tightly connected to the S1R and the addition of BAPTA-AM did not affect the expression of the S1R. H Immunofluorescence showed a decrease in intracellular IP3R expression after addition of BAPTA-AM, and conversely, an increase in IP3R expression after inhibition of the S1R. I Western blot showed addition of BAPTA-AM inhibited PERK and IP3R-VDAC1-MCU signaling pathways and alleviated endoplasmic reticulum stress and mitochondrial damage. J The statistical analysis diagrams of IP3R, S1R, Bip, PERK, p-PERK, eIF2α, p-eIF2α, ATF4, VDAC1, and MCU protein expression relative to GAPDH in cardiomyocyte (n = 3). **p < 0.01; ***p < 0.005; ****p < 0.001