Figure 7.

ERO1α-mediated stimulation of IP₃R activity is critical for ER Ca²⁺ release. (A) Representative images of p-IP3R showed that OGD treatment increased the phosphorylation of IP₃R, which was reversed by EndoA2 overexpression and further strengthened by EndoA2 siRNA knockdown. Scale bars: 50 µm (n=6). (B) Representative images of t-IP₃R showed that t-IP₃R was not changed under the indicated conditions (n=4). (C) Pretreatment with 2-APB inhibited intracellular Ca²⁺ release induced by OGD treatment. Scale bars: 50 µm. (n=6). (D-E) Western blotting results showed the expression of cleaved caspase-3, Bax and Bcl-2 after being treated with 2-APB. Densitometric analyses showed that the change of apoptosis-related protein induced by OGD was reversed by pretreatment with 2-APB (n=6, * p <0.05 vs. control, # p <0.05 vs. OGD). (F) qRT-PCR detection of ERO1α mRNA expression. EndoA2 overexpression decreased ERO1α mRNA expression induced by OGD, while EndoA2 siRNA knockdown further increased it (n=6, ** p <0.01 vs. control, ## p <0.01 vs. OGD+Ad-lacZ or OGD+neg). (G) Representative images showed that ERO1α siRNA knockdown attenuated the phosphorylation of IP₃R induced by OGD or EndoA2 siRNA knockdown. Scale bars: 50 µm (n=6). (H-I) Western blotting results showed that ERO1α siRNA knockdown reversed the change of apoptosis-related protein induced by OGD or EndoA2 siRNA knockdown (n=6, * p <0.05 vs. control, # p <0.05 vs. OGD+neg, & p <0.05 vs. OGD+EndoA2 si).