胶质细胞源性神经营养因子在小鼠生精恢复过程中的表达和意义

目的:分析并探讨胶质细胞源性神经营养因子(GDNF)在小鼠恢复生精过程中的表达变化,及其与精原干细胞增殖与分化的关系。方法:间隔24 d 2次腹腔注射白消安建立小鼠生精恢复过程的动物模型。根据第二次给药后的不同时间随机分为1、2、3、4、6、8、10周共7组(8只/组),8只正常小鼠作对照组,分别于相应时点取材,进行光镜和电镜的研究。采用半定量逆转录聚合酶链反应(RT-PCR)检测不同时间GDNF mRNA的表达变化;并采用原位杂交技术检测GDNFmRNA表达定位。结果:2次给药后第1-2周,GDNF mRNA的表达明显增强,在第2周达到高峰;在给药后第3-4周明显下降,并在第4周达到低谷;随后几周内表达又逐渐增强,于第10周恢复到正常水平。原位杂交显示,GDNF由sertoli细胞表达。结论:在小鼠生精恢复过程中,GDNF的高水平表达促进精原干细胞自我更新,对于维持生精上皮干细胞数量的稳定具有十分重要的意义。

Expression and significance of GDNF gene in spermatogenesis recovery of mouse

Objectives: To discuss the expression and significance of glial cell derived neurotrophic factor (GDNF) in the spermatogenesis recovery of mouse. Methods: Adult Kunming mice were injected introperitoneally with 2 doses of busulfan (10 mg/kg) 24 days apart so as to establish the spermatogenesis recovery model. Testes were harvested at week 1,2, 3,4, 6, 8,10 after the second injection, while 8 normal mice were used as control. The spermatogenesis recovery was observed by light and electron microscopy, the GDNF mRNA was measured by semi-quantitative RT-PCR and in situ hybridization. Results: After the second injection the expression of GDNF mRNA increased significantly at week 1 and reached its peak at week 2 then it reduced significantly at week 3 and reached its valley at week 4. It increased gradually and recovered at week 10. The GDNF mRNA was mainly expressed by Sertoli cells. Conclusion: In the course of spermatogenesis recovery, the expression of GDNF at a high level plays a key role to promote self-renewal and maintain the number of spermatogonial stem cells.