Effects Of Estrogen Mediated By Gper On EGFR And C-fos Expression In Mice Ovary

Epidermal growth factor receptor is a transmembrane receptor of the tyrosine kinase receptor family. It mediates living organisms such as cell growth, proliferation and differentiation through binding with its ligand. It has been proved that the EGFR involved in the regulation of ovarian follicular development and oocyte maturation. C-fos gene is a proto-oncogene. It controls early cell division and proliferation and closely related to the proliferation and differentiation of ovarian granulosa cells. The EGFR and c-fos is the important factors in the membrane estrogen receptor signal transduction pathway mediated by G-protein-coupled estrogen receptor. In order to investigate the mechanism of GPER effect on EGFR and c-fos in ovary during the estrous cycle.This experiment use immunohistochemistry method and real-time quantitative RT-PCR method, through injected with different doses of GPER specific agonists G-1 and antagonists G-15 in estrous cycle mice, to research estrogen effect on EGFR and c-fos expression mediated by GPER in mouse ovary. The main results obtained are as follows:1. Distribution and expression of EGFR and c-fos in mice ovary during estrous cycleEGFR distributed in granulosa cells and oocytes of all levels of follicles in mouse ovary during the estrous cycle, and the closer to the oocyte, the granule cells expression stronger. The relative expression of EGFR in estrus is significantly higher than proestrus(P<0.05), the proestrus significantly higher than the diestrus(P <0.05), the lowest metestrous significantly lower than the other three periods(P <0.01). The expression of EGFR mRNA is consistent with the relative expression of EGFR.The distribution of c-fos in ovary mice during the estrous cycle is similar with EGFR. The relative expression of c-fos is estrus>proestrus>diestrus> metestrus, and the difference between the two adjacent extremely significantly(P <0.01). The expression of c-fos mRNA is consistent with the relative expression of and c-fos.2. Effect of G-1on expression of EGFR and c-fos in mice ovary during the estrus cycleIt can promote the expression of EGFR and EGFR mRNA after the diestrus mice treated with G-1. In addition to the metestrous, the relative expression of EGFR in the other three period ovary in 200 ng G-1 injection group and 1000 ng G-1 injection group are significantly increased(P<0.05). The expression of EGFR mRNA throughout the estrous cycle, its 200 ng G-1 injection group and 1000 ng G-1 injection group are significantly higher than the control(P <0.01).It can also promote the expression of c-fos and c-fos mRNA after the diestrus mice treat with G-1. The changes of c-fos relative expression in the estrous cycle is similar with EGFR. The expression of c-fos mRNA in diestrus, proestrus and estrus between different doses of G-1 injection group are extremly significant different(P <0.01). In metestrus 40 ng G-1 injection group and the control group had no significant difference(P>0.05). 1000 ng G-1 injection group and 200 ng G-1 injection group are extremly significantly different(P <0.01).3. Effect of G15 on expression of EGFR in mice ovary during the estrus cycleIt can decrease the expression of EGFR after the diestrus mice treated with G15. The relative expression of diestrus, proestrus and estrus in 0.3 nmolG15 injection group and 1.5 nmolG15 injected group decrease significantly and the difference is extremely significant(P<0.01); but there was no significant difference between 7.5 nmolG15 injection group and 1.5 nmolG15 injection group(P> 0.05). The expression of EGFR mRNA is consistent with the relative expression of and EGFR.In summary, the expression of EGFR and c-fos in mouse ovaries varies with the estrous cycle. It is closely related with ovarian follicle growth and physiological functions changes. G-1 and G15 can promote and inhibate the expression of EGFR and c-fos on the estrous cycle ovary indicate that GPER play a regulatory role on ovarian function activities by activating EGFR and c-fos in the signaling pathway.