VEGF Modulates The Effects Of Proliferation In Granulosa Cells

Follicle selection is associated with an increase in the expression of vascular endothelial growth factor (VEGF) and its receptors in granulosa cells, however, the roles of VEGF in regulating the function of these or other non-endothelial cells in the ovary have not been explored in detail.Explore the pathway of VEGF promote Granulosa cells can know the novel and important roles of VEGF in proliferation apoptosis.The study on the expression of VEGF in ovary of sheep not only bring the theory base for the high propagate and breeding regulation and reproductive potential but also establish the foundation of developing vaccine and medicine for the reproductive performance.The current study used sheep cell cultures to investigate potential roles of VEGF in the regulation of granulosa cell function during prolifation and apoptosis.The granulosa cell from10adult female small fat-tail sheep’s morphologically healthy follicles2to7mmin diameternd was cultured and stimulated with different concentrations of VEGF (5to25ng/mL).The cellular proliferation was detected by MTT, the expression of P-ERK1/2and p-JNK was detected by western blot and theAnnexin V-FITC detect apoptosis.The results of MTT showed a significant affection of granulosa cell proliferation by different concentration of VEGF and the5ng/ml was the best. Western blot showed the expression of P-ERK1/2increased significantly with the increasing of VEGF concentrations, and the optimized was5ng/ml (P<0.05), the continued increasing of VEGF was insignificant to effect the expression of P-ERK1/2, like the10,15and20ng/ml. However, the inhibition of VEGF with the concentration of25ng/ml weakened with the continued culture. The Conclusion shown that different levels of VEGF affect different proliferation in granulosa cell, especially in5ng/ml.The expressions of P-ERK1/2in48h is a little higher than in24h,and the peak of the expression also in5ng/ml. The expressions of P-JNK the same as P-ERK1/2,5ng/ml show the high leveal.We can conclude that VEGF can activate ERK1/2and JNK pathway and then increase the proliferation on sheep’s granulosa cellsInterestingly, the stimulatory effects of VEGF on ERK1/2phosphorylation in granulosa cells were abolished by specific chemical inhibition of VEGF receptor2(VEGFR2). These results suggest novel and important roles of VEGF and its receptor, VEGFR2, in mediating and/or enhancing the proliferation in granulosa cells. The FMC show VEGFcan inhibition the apoptosis of granulosa cells. The results of this study suggest potentially important roles of VEGF, independent of its angiogenic effects, in the regulation of granulosacell function at different stages during the development of the dominant follicle. Studies should follow to confirm the proposed novel role of VEGFR2in mediating peri-ovulatory responses.