Roles Of Fas And TNF-α Systems In Corticosterone-and CRH-induced Apoptosis Of Mouse Oviduct Epithelial Cells

Previous studies in our laboratory have shown that restraint stress of female mice before embryo implantation could promote the secretion of stress hormones CRH and CORT in large quantities and induced apoptosis of oviduct epithelial cells which Fas L/Fas system and TNF-α/TNFR1 system were involved in.It was further demonstrated in vitro that CRH and CORT induced apoptosis of tubal epithelial cells through the Fas signaling pathway,but whether the TNF-system was involved in remained unclear.In this study,we used the model of mouse oviduct epithelial cells added CRH and CORT in vitro to study which signal pathway of the apoptosis of oviduct epithelial cells they affect.The results showed that in the experimental group the proportion of healthy cells decreased significantly as well as the proportion of apoptosis increased significantly,（healthy cells:89.6%vs 64.8%vs 64.8%,early apoptosis:9.4%vs 29.5%vs 29.9%）（P<0.05）,and the ratio of Bcl-2/Bax decreased significantly compared with the control group after adding CRH(2×10^-6 M)and CORT(1×10^-5 M)（P<0.05）,indicating that the addition of CRH and CORT promoted the apoptosis of tubal epithelial cells.The addition of CRH to tubal epithelial cells in vitro resulted in significantly higher expression of TNF-and Fas L compared with the control group,while the expression of Fas L was significantly increased after adding CORT,but the expression of TNF-αwas significantly decreased.We used si RNA interference technology to knock down the expression levels of TNF-αand Fas L in fallopian tube epithelial cells,and then cultured with hormone.It was found that after knocking down Fas L,the ratio of Bcl-2/Bax in cultured fallopian tube epithelial cells cultured with CRH and CORT was significantly increased（P<0.05）.However,After knocking down TNF,although the ratio of Bcl-2/Bax in the tubal epithelial cells cultured with CRH in vitro increased significantly（P<0.05）,the ratio of Bcl-2/Bax in the CORT group decreased significantly.In addition,compared with the control group,the proportion of healthy cells was significantly increased and the proportion of apoptotic cells decreased significantly（healthy cells:63.2%vs 70.7%vs 70.1%,early apoptosis:31.7%vs26.4%vs 27.4%）after the addition of CRH after knocking down Fas L and TNF-α.Similarly,compared with the control group,the proportion of healthy cells increased significantly and the proportion of apoptotic cells decreased significantly（healthy cells:62.6%vs 71.1%,early apoptosis:33.3%vs 27.7%）in the tubal epithelial cells in vitro cultured with CORT after knocking down Fas L.However,when TNF-αwas knocked down and CORT was added to culture oviduct epithelial cells in vitro,The proportion of healthy cells and early apoptotic cells was not significantly different from that of the control group.（healthy cells:62.6%vs 63.0%,early apoptosis:33.3%vs 31.0%）.After acquiring oviduct epithelial cells from Fas L deficient and TNF knockout mice,CRH and CORT were added in vitro.Compared with wild-type mouse cells,the apoptosis of the two mutant cells was alleviated after adding CRH（healthy cells:66.9%vs 81.8%vs 81.1%,early apoptosis:24.2%vs 16.4%vs 16.8%）.However,when CORT was added,only the apoptosis of mice with Fas L gene mutation was alleviated,but not in TNF-αknockout mice.In conclusion,our experimental results showed that CRH induced apoptosis of oviduct epithelial cells involved Fas and TNF-αsystems,while CORT induced apoptosis of oviduct epithelial cells through Fas pathway,but not TNF-αsystem.