Figure 5.

The increased cell senescence, p38 mitogen-activated protein kinase (MAPK) phosphorylation, and downregulated sirtuin 3 (SIRT3) expression induced by hydrogen peroxide (H₂O2) were enhanced in PGRMC1 knockdown chorion cells. A, Senescence cell histochemical staining of chorion cells treated with 0 and 300 μM H₂O2 for 24 hours in scrambled small-interfering RNA (siRNA)-transfected chorion cells (CsiRNA) and in PGRMC1 knockdown cells (PsiRNA). SA-β-Gal-positive chorion cells are blue in representative images. B, The proportion of SA-β-Gal-positive chorion cells is summarized in a bar graph. C, Representative Western blot image to demonstrate the p38 MAPK phosphorylation under 300 μM H₂O2 treatment at 30 minutes in CsiRNA and PsiRNA groups. Densitometry analysis was summarized in a bar graph (N = 8). D, Representative Western blot image to demonstrate SIRT3 protein expression in CsiRNA and PsiRNA groups and densitometry analysis was summarized in a bar graph (N = 10). MAPK indicates mitogen-activated protein kinases; H₂O2, hydrogen peroxide; PGRMC1, progesterone receptor membrane component 1; siRNA, small-interfering RNA; SIRT3, sirtuin 3.