Effect of PHB knockdown on STS-induced caspase-3 cleavage and apoptosis. Undifferentiated (A) and differentiated (B) granulosa cells were infected with adenoviral-shPHB (MOI = 10, adenoviral-shNeg as control) for 48 h and then cultured with STS (1μM, 2 h). The contents of cleaved, intact caspase-3 and PHB were examined by Western blot and the apoptosis rate of granulosa cells were assessed by nuclear morphology (Hoechst staining). Data are presented as mean ± SEM of three independent experiments and analyzed by two-way ANOVA and subsequently by Bonferroni post hoc test. **, p < 0.01 (compared with LacZ). NS: not significant.