de Winter J P, Vanderstichele H M, Verhoeven G, Timmerman M A, Wesseling J G, de Jong F H
Department of Endocrinology and Reproduction, Medical Faculty, Erasmus University, Rotterdam, The Netherlands.
Endocrinology. 1994 Aug;135(2):759-67. doi: 10.1210/endo.135.2.8033824.
The expression of activin type II and IIB receptors and inhibin alpha-, beta A-, and beta B-subunit messenger RNAs (mRNAs), and the secretion of immunoreactive and bioactive activin during culture of testicular peritubular myoid cells and peritubular myoid cell lines were studied. Cultured peritubular myoid cells and cell lines expressed high levels of inhibin beta A-subunit mRNA and some inhibin alpha- and beta B-subunit mRNA. Activin receptor type II mRNA was also detected, whereas activin receptor type IIB mRNA expression was not found. Expression of the beta A-subunit mRNA was present immediately after isolation of the cells and increased during culture in Eagle's Minimum Essential Medium containing 10% fetal calf serum. beta A-Subunit mRNA expression was not regulated by the synthetic androgen R1881. Western blotting of peritubular myoid cell- and peritubular cell line-conditioned media with a polyclonal antiserum against recombinant activin-A revealed the presence of 25-kilodalton activin-A, whereas activin bioactivity was detected using the animal cap assay. Because of the secretion of activin-A by peritubular myoid cells, the effects of recombinant activin-A on Sertoli cell inhibin and transferrin secretion were examined. Activin-A stimulated both basal and FSH-stimulated inhibin and transferrin production by Sertoli cells after 72 h of culture. These effects resemble the effects of the testicular paracrine factor PmodS on Sertoli cell function. It is concluded that activin-A is secreted by peritubular cells in vitro and that activin-A shares a number of effects on Sertoli cell function with PmodS.
研究了睾丸生精小管周肌样细胞和生精小管周肌样细胞系培养过程中激活素II型和IIB型受体以及抑制素α、βA和βB亚基信使核糖核酸（mRNA）的表达，以及免疫反应性和生物活性激活素的分泌。培养的生精小管周肌样细胞和细胞系表达高水平的抑制素βA亚基mRNA以及一些抑制素α和βB亚基mRNA。还检测到激活素II型受体mRNA，而未发现激活素IIB型受体mRNA的表达。细胞分离后立即出现βA亚基mRNA的表达，并在含有10%胎牛血清的伊格尔最低限度基本培养基中培养期间增加。βA亚基mRNA的表达不受合成雄激素R1881的调节。用针对重组激活素A的多克隆抗血清对生精小管周肌样细胞和生精小管细胞系条件培养基进行蛋白质免疫印迹分析，结果显示存在25千道尔顿的激活素A，而使用动物帽试验检测到了激活素的生物活性。由于生精小管周肌样细胞分泌激活素A，因此研究了重组激活素A对支持细胞抑制素和转铁蛋白分泌的影响。培养72小时后，激活素A刺激支持细胞基础分泌以及促卵泡激素刺激的抑制素和转铁蛋白的产生。这些作用类似于睾丸旁分泌因子PmodS对支持细胞功能的作用。得出的结论是，激活素A在体外由生精小管周细胞分泌，并且激活素A与PmodS在支持细胞功能方面具有许多共同作用。
