c-myb调查大鼠睾丸间质细胞睾酮分泌

［摘要］采用离体细胞体外孵育法，观察反义c-myb寡脱氧核苷酸(oligodeoxynucleotides，ODN)，对人绒毛膜促性腺激素(human chorionic-gonadotropin hormone，hCG)诱导的大鼠间质细胞睾酮分泌的影响，并进一步探讨了外源性二丁酞cAMP(dbcAMP)ca2+以及蛋白质抑制剂放线菌酮(cycloheximide，CYX)对间质细胞中c-Myb蛋白表达和睾酮分泌的作用。结果表明，反义c-myb ODN呈剂量依赖性地抑制hCG诱导的离体间质细胞的睾酮分泌，同时使间质细胞中c-Myb蛋白免疫组化染色IOD值下降；而无义tat ODN没有相应的作用。100μmol/L的dbcAMP可进一步促使hCG诱导的间质细胞分泌睾酮，并且使间质细胞中c-Myb蛋白免疫组化染色IOD值升高，与hCG组相比，具有统计学意义。钙离子通道阻断剂维拉帕米(10μmol/L)和蛋白质抑制剂放线菌酮(50μg/ml)可使hCG诱导的大鼠间质细胞的睾酮分泌下降，并使间质细胞的c-Myb蛋白免疫组化染色IOD值降低。这些结果说明c-myb参与hCG诱导的大鼠睾丸间质细胞睾酮分泌作用。

［关键词］间质细胞；c-myb；反义寡脱氧核苷酸；睾酮

Effect of c-myb on hCG-induced testosterone secretion in isolated rat Leydig cells

［Abstract］The present study was carried out to investigate the effect of antisense cmyb oligodeoxynucleotides(ODN)on hCG-induced testosterone secretion in isolated rat Leydig cells.The effects of cAMP，ca2+and cycloheximide(CYX)on c-Myb protein expression and testosterone secretion were observed.The results showed that antisense c-myb ODN inhibited hCG-induced testosterone secretion of isolated rat Leydig cells in a dose-dependentmanner.At the same time，integral optical density immunostaining of Myb in Leydig cells was also remarkably reduced.Nonsense tat ODN had no effect on Leydig cells.Further experiments showed that dbcAMP(100μmol/L)obviously increased hCG-induced testosterone secretion and integral optical density(IOD)immunostaining of Myb in Leydig cells.Verapamil(10μmol/L)，a ca2+channel blocker，and cycloheximide(50μg/ml)，a protein synthesis inhibitor，reduced the immunostaining of c-Myb，and also lowered hCG-induced testosterone secretion in isolated rat Leydig cells.The results indicate that c-myb closely correlates with hCG-induced testosterone secretion，and that cAMP and ca2+-dependent pathway participates in the expression of protooncogene.(www.xing528.com)

［Key words］Leydig cells； c-myb； antisense oligodeoxynucleotides； testosterone

原癌基因(proto-oncogene)是细胞基因组的正常成分，其编码的产物多为细胞因子及受体、核内蛋白质等一类同细胞信号传递有关的蛋白，与细胞的增殖分化和信息传递等有密切关系，是生命所必需的基因［1］。近年来许多研究结果表明，某些原癌基因，特别是即时早期基因(immediate-early genes，IEGs)如c-fos，c-jun，c-myc等，它们的正常表达与睾丸间质细胞的睾酮分泌功能有着密切的关系［2-4］。然而有关c-myb原癌基因与正常间质细胞功能之间的关系报道极少。原癌基因c-myb，其表达的产物为c-Myb，属DNA结合核蛋白。这类蛋白质在胞浆中生成后，又进入细胞核内，作为转录因子与靶基因序列结合，从而调控某些基因转录以实现靶细胞的功能。本文利用反义cmyb寡脱氧核苷酸(oligodeoxynucleotides，ODN)阻断原癌基因c-myb表达，观察hCG诱导的大鼠睾丸间质细胞睾酮分泌的变化，并进一步探讨外源性二丁酞cAMP(dbcAMP)、放线菌酮(cycloheximide，CYX)和钙离子对间质细胞c-myb表达的影响。