Cyclin G1在小鼠卵巢颗粒细胞的表达及调控

目的:探讨cyclinG1在小鼠卵巢颗粒细胞的表达以及促性腺激素对其表达的调控作用。方法:以免疫组化方法检测小鼠卵巢颗粒细胞中cyclinG1的表达情况;取性成熟小鼠的颗粒细胞进行体外培养,分别加入卵泡刺激素(FSH)和绒毛膜促性腺激素(hCG)作用12h后,收集细胞,提取细胞总RNA,采用半定量RTPCR检测cyclinG1表达水平的变化。结果:免疫组化结果显示cyclinG1在不同发育阶段卵泡的颗粒细胞和卵丘细胞中均有较强表达,而黄体细胞中表达较少。RTPCR结果显示,FSH与hCG分别作用于体外培养的颗粒细胞12h后,与对照组比较,hCG可使cyclinG1的表达水平明显降低(P<0.01),FSH对其表达水平影响不明显(P>0.05)。结论:小鼠卵巢颗粒细胞中存在cyclinG1表达;hCG可降低cyclinG1在颗粒细胞中的表达水平,提示cyclinG1在颗粒细胞增殖分化过程中可能发挥正调节作用。

Expression and regulation of cyclin G1 in mouse granulosa cells

Objective:To investigate the expression of cyclin G1 in mouse granulosa cells and whether the level of cyclin G1 expression is regulated by gonadotropins. Methods: The immunohistochemistry was used to analyze the expression of cyclin G1 in mice ovarian granulosa cells.Granulosa cells from sexual mature mice were cultured in vitro and then treated with follicle-stimulating hormone(FSH)and human chorionic gonadotropin(hCG)respectively.Total RNA was purified from each sample.The changes in expression level of cyclin G1 was analyzed by semiquantitative RT-PCR in which GAPDH (glyceraldehyde-3-phosphate dehydrogenase) was used as control for the integrity of the RNA. Results: cyclin G1 was detected in granulosa cells and cumulus cells of all developmental stages ovarian follicles,while its expression in corpora lutea was significantly decreased.Semiquantitative RT-PCR showed that cyclin G1 was decreased in response to hCG(P<0.01),but no significantly difference was found to FSH compared with control(P>0.05). Conclusion:The results showed that cyclin G1 mRNA was decreased in granulosa cells by treatment with hCG,indicating that cyclin G1 may act as a positive effector during mouse granulosa cells proliferation and differentiation.