Relaxin has anti-apoptotic effects on human trophoblast-derived HTR-8/SV neo cells.

The study was conducted to evaluate the effects of human relaxin on apoptosis in the human trophoblast derived HTR-8/SV neo cell line, which is a possible model of human extravillous trophoblasts (EVTs). HTR-8/SV neo cells, cultured in phenol red free RPMI1640 medium, were treated with different doses of human recombinant (rH2) relaxin in serum-deprived conditions. RT-PCR was used for evaluating relaxin receptor: RXFP1 and RXFP2 expression in HTR-8/SV neo cells. The cell death was examined by TUNEL assay. Furthermore, we investigated caspase-3, cleaved PARP and Bcl-2 expressions by Western blot analysis to recognize the translational effects of anti-apoptotic and pro-apoptotic proteins. RXFP1 and RXFP2 mRNA expression was observed in HTR-8/SV neo cells. Compared with untreated control cultures, treatment with rH2 relaxin, decreased TUNEL-positive rate in HTR-8/SV neo cells was observed. Western blot analysis revealed that treatment with rH2 relaxin decreased the expression of caspase-3 and cleaved PARP, but in contrast increased Bcl-2 expression in those cells. These results suggest that rH2 relaxin has anti-apoptotic effects on HTR8/SV neo cells by decreasing pro-apoptotic caspase-3 and cleaved PARP expression and up-regulating anti-apoptotic Bcl-2 expression.