GnIH对鸽卵泡颗粒细胞和膜细胞中生殖激素受体及类固醇激素生成的影响OA

The study aimed to investigate the effect of GnIH on gonadal development in pigeons.In this study,graded follicular granulosa cells and theca cells of Mimas breeding pigeons were subjected to primary culture,followed by separate treatments with different concentrations of GnIH polypeptide or transfected them with siRNA-GnIH for interference(n=6).For the GnIH polypeptide treatment assay,the control group(Group Ⅰ)was treated with PBS at a GnIH polypeptide concentration of 0 ng·mL-1,while the experimental groups(Groups Ⅱ,Ⅲ,and IV)were treated with GnIH polypeptides at concentrations of 1,10,and 100 ng·mL-1,respectively.For the GnIH interference assay,the control group was transfected with siRNA-NC,whereas the experimental group was transfected with siRNA-GnIH(5 μL,20 μmoL·L-1).The results showed that GnIH polypeptide treatment significantly downregulated the mRNA and protein levels of GnIH and FSHR in granulosa cells(P＜0.05),significantly decreased the mRNA levels of GnIHR,LHR,and StAR in granulosa cells(P＜0.05),significantly inhibited the secretion of E2 and P4 in granulosa cells(P＜0.05),and significantly upregulated the mRNA level of GnIH in theca cells(P＜0.05),while the mRNA level of GnIHR in theca cells gradually decreased with increasing treatment concentration.After siRNA-GnIH interference,the mRNA and protein levels of GnIH in both granulosa and theca cells were significantly downregulated(P＜0.05),while the mRNA levels of FSHR and LHR in granulosa and theca cells were significantly upregulated(P＜0.05).Additionally,the protein level of FSHR in theca cells was significantly increased(P＜0.05),and the mRNA and protein levels of StAR and 3β-HSD in both granulosa and theca cells were significantly upregulated(P＜0.05),along with the mRNA level of CYP19A1 was significantly upregulated in granulosa cells(P＜0.05).Furthermore,siRNA-GnIH promoted E2 expression in both granulosa and theca cells(P＜0.05),but inhibited P4 secretion in granulosa cells(P＜0.05).These results indicated that GnIH exerts similar effects on gonadotropin receptors and steroidogenesis in granulosa and theca cells of pigeon as observed in other avian species.GnIH polypeptide significantly suppresses gonadotropin receptor expression,downregulates steroidogenic pathway factors and inhibits steroid hormone secretion,whereas GnIH interference produces the opposite effects in granulosa cells.While GnIH polypeptide shows no significant impact,GnIH interference markedly enhances gonadotropin receptor expression,steroidogenic pathway activity and steroid hormone secretion in theca cells.