p38 MAPK在小鼠睾丸不同发育阶段的表达和定位

为探讨丝裂原活化蛋白激酶p38 MAPK在小鼠睾丸不同发育阶段的表达，应用蛋白质免疫印迹杂交技术和免疫组织化学SABC法检测1至7周龄小鼠睾丸p38 MAPK的表达、定位及发育变化，并通过图像分析技术对免疫组织化学结果进行统计学分析。免疫印迹杂交发现，p38 MAPK在2～7周龄小鼠睾丸中均有表达。免疫组织化学结果显示，在2周龄小鼠睾丸曲细精管上皮中即可观察到p38 MAPK免疫阳性反应，免疫反应阳性细胞为精原细胞；3、4、5周龄小鼠睾丸仅有个别曲细精管上皮可见p38 MAPK免疫阳性反应；6、7周龄小鼠睾丸中p38 MAPK表达较丰富，免疫反应阳性细胞为精原细胞和初级精母细胞，免疫阳性反应物均主要位于细胞核内。在7周龄小鼠睾丸中还可见到部分间质细胞的细胞质亦呈p38 MAPK阳性。这些结果提示，p38 MAPK可能对生精细胞的增殖分化具有调控作用。

Expression and location of p38 MAPK in the mouse testis during postnatal development

In order to elucidate the mechanism of p38 Mitogen-activated protein kinase (p38 MAPK) action in spermatogenesis, we investigated the expression and developmental changes of p38 MAPK in mouse testis during postnatal development. In this study, whole testes were collected from 1- to 7 -week-old male mice. We examined the expression of p38 MAPK during mouse testicular development by means of Western blots and its cellular localization by the immunohistochemical SABC method. The percentage of immunohistochemical positive area at each developmental stage was measured with an image analysis system. After a variance homogeneity test, the data were analyzed by one-way ANOVA with SPSS 10 0 for Windows. The Western blots showed that p38 MAPK was expressed in 2- to 7-week-old mice testis, i.e., there was one band in the testes of mice from each developmental group. The immunostaining of p38 MAPK occurred first in the spermatogonium of 2-week-old mice's testes, and positive substance was located in the nucleus. Only a few semini- ferous tubules were p38 MAPK positive in 3- to 5-week-old mice, whereas the expression of p38 MAPK was abundant in testes of 6- and 7-week-old mice. The immunostaining of p38 MAPK was localized in the nucleus of the spermatogonium and primary spermatocyte. In addition, the cytoplasm of some Leydig cells in the testes of 7-week-old mice was p38 MAPK positive. Nothing was observed in the negative controls. The result of image and statistical analysis showed that the expression of p38 MAPK decreased after 2 weeks and increased again until weeks 6-7. We systemically investigated the expression and localization of p38 MAPK in the mouse testis at different developmental stages. The immunostaining of p38 MAPK was mainly present in the spermatogonium and primary spermatocytes, so it could appear that p38 MAPK may contribute to the mitotic proliferation of the spermatogonium and the early phase of succedent meiosis. Our finding of p38 MAPK expression in Leydig cells suggests that it may influence the function of the testis by regulating the function of these cells. The cellular localization and developmental changes of p38 MAPK in mouse testis suggest that it may play an important role in promoting testicular development and maintaining spermatogenesis,which provides an insight into the regulatory mechanism of p38 MAPK in mouse spermatogenesis and testicular function,and has important significance for comprehensively understanding the mechanism by which p38 MAPK acts in reproduction and development.