原癌基因c-erbB_2在原始卵泡启动生长中的作用

目的:探讨原癌基因c-erbB2在原始卵泡启动生长中表达变化及可能的作用。方法:选用2日龄SD大鼠卵巢在Waymouth培养体系中进行体外培养,用原位杂交、RT-PCR和免疫组化方法检测c-erbB2mRNA和蛋白在原始卵泡启动生长中及在表皮生长因子(EGF)作用下的表达情况,用Westernblot方法同步测定卵泡活化生长的重要标志物——增殖细胞核抗原(PCNA)和磷酸化细胞外信号调节激酶1/2(p-ERK1/2)的表达情况,并分析p-ERK1/2与c-erbB2mRNA表达变化的相关关系。结果:伴随原始卵泡启动生长过程,PCNA表达逐渐增加,EGF能促进原始卵泡的增殖和分化;原始卵泡中有c-erbB2mRNA及蛋白的表达,且随原始卵泡的启动生长及在EGF作用下表达增强;RT-PCR结果显示,c-erbB2mRNA表达在2日龄大鼠卵巢培养8d后与培养0d相比显著增加(0.297±0.018vs0.178±0.011,P0.05),并在EGF作用下进一步增强;p-ERK1/2含量的变化与c-erbB2mRNA表达的变化呈显著的正相关关系(rs=0.900,P0.05)。结论:c-erbB2在原始卵泡启动生长中起重要促进作用,并为介导EGF促进原始卵泡启动生长的关键信号分子;ERK-MAPK信号通路可能在介导c-erbB2调控原始卵泡生长中起作用。

Roles of proto-oncogene c-erbB_2 during the initiation growth of rat primordial follicles

Objective：To study the expression and possible roles of proto-oncogene c-erbB2 during the initiation growth of primordial follicles.Methods：Ovaries were collected from 2-day-old SD rats and cultured in the Waymouth culture system.In-situ hybridization,RT-PCR and immunohistochemistry were performed to assess the expressions of c-erbB2 mRNA and protein during the initiation growth of primordial follicles and after the effect of EGF.Western blot was used to observe the PCNA,p-ERK1/2 contents and correlation analysis was used to study the correlation relationship between contents of p-ERK1/2 and expressions of c-erbB2 mRNA at the same time of the primordial follicles growth.Results：PCNA protein levels appeared to be more intense during the initiation growth of primordial follicles,EGF could promote the proliferation and differentiation of the primordial follicles.c-erbB2 mRNA existed in the oocytes endochylema and ErbB2 existed in the oocytes membran,the expressions of c-erbB2 mRNA and ErbB2 appeared to be more intense when primordial follicles were cultured for 8 d than cultured for 0 d in the Waymouth culture system and were further increased with 50 ng/ml EGF for 4 d and 8 d.The same results were observed by RT-PCR,too.p-ERK1/2 protein levels were consistent with the changes of c-erbB2 mRNA and protein.Furthermore,Spearman rank correlation analysis showed there was a significant positive correlation relationship between the changes of p-ERK1/2 and the changes of c-erbB2 mRNA during the primordial follicles growth and after the effect of EGF（rs=0.900,P0.05）.Conclusion：It was suggested that proto-oncogene c-erbB2 may be play an important role during the initiation growth of primordial follicles with EGF,and it is indirectly suggested that c-erbB2 promotes the development of the primordial follicles via ERK-MAPK signal transduction.