Figure 5.

Expression of PGRMC1 and mPRα in SIGCs stably transfected with PGRMC1 (PG). A, detection of PGRMC1 mRNA in PG- and V-transfected cells by RT-PCR and PGRMC1 protein in transfected cell membranes by Western blot analysis. B, Detection of mPRα mRNA and mPRα protein in PG and V cell membranes (for rat PGRMC1 and mPRα RT-PCR primers see Supplemental Figure 4). C, Immunocytochemistry of PGRMC1 (left) and mPRα (right) proteins in PG and V cells. D, Specific [³H]P4 binding to plasma membranes of PG and V cells in a single point assay. E, Effects of progesterone treatment (1 nM, 16 hours) on serum starvation-induced apoptosis of PG and V cells. F, Effects of transfection of PG SIGC cells with mPRα siRNA (si-mPRα) or nontarget siRNA (n-t) on membrane mPRα and PGRMC1 mRNA (bottom) and protein expression (top). G, Comparison of specific [³H]P4 binding to SIGCs transfected with mPRα or nontarget siRNA in a single-point binding assay. H, Effects of progesterone (P4) treatment (1 nM, 16 hours) on apoptosis of serum-starved SIGCs after transfection with mPRα or nontarget siRNA. V1,V2, PG1, PG2: separate clones of transfected SIGCs; M, DNA size marker and molecular weight marker; Veh, vehicle; Int, integrin. *, P < .05 compared with V controls (D) or corresponding Veh controls (H), n = 6; **, P < .01 compared with corresponding controls (F), n = 6; ***, P < .001 compared with corresponding V controls (E) or nontarget controls (G), n = 6. All the experiments were repeated 3 or more times and similar results were obtained in each experiment.