Richardson L L, Kleinman H K, Dym M
Department of Cell Biology, Georgetown University Medical Center, Washington, DC 20007, USA.
J Androl. 1998 Mar-Apr;19(2):145-55.
The basement membrane plays an important role in maintaining the structural and functional integrity of tissues. Altered basement membrane structure has been associated with severe functional impairment of the testis in several conditions, including vasectomy, autoimmune orchitis, cryptorchidism, and following x-irradiation. We have used efferent duct ligation as a model to examine seminiferous tubular basement membrane morphology, synthesis, and gene expression to determine whether altered basement membrane synthesis is responsible for the aberrant structures noted after tissue injury. On days 2 and 3 after ligation, both the seminiferous epithelium and the basement membrane appeared normal, but 7 days after ligation, the seminiferous epithelium began to degenerate. The basement membrane appeared detached from the epithelium, and redundant patches of basement membrane were observed adjacent to the Sertoli cells at 14 and 21 days postligation. Immunoprecipitation indicated an increase in laminin protein synthesis in the ligated tubules at the same time. Northern blot analysis showed increases in transcript levels for laminin as well as collagen IV and heparan sulfate proteoglycan. These data show that new protein synthesis is responsible, at least in part, for the duplication of the basement membrane coincident with the tissue damage caused by efferent duct ligation.
基底膜在维持组织的结构和功能完整性方面发挥着重要作用。在多种情况下，包括输精管结扎、自身免疫性睾丸炎、隐睾症以及X射线照射后，基底膜结构的改变与睾丸的严重功能损害有关。我们使用输出小管结扎作为模型来检查生精小管基底膜的形态、合成和基因表达，以确定基底膜合成的改变是否是组织损伤后出现异常结构的原因。结扎后第2天和第3天，生精上皮和基底膜均显示正常，但结扎后7天，生精上皮开始退化。基底膜似乎与生精上皮分离，并且在结扎后14天和21天，在支持细胞附近观察到基底膜的多余斑块。免疫沉淀表明，同时结扎小管中层粘连蛋白的合成增加。Northern印迹分析显示层粘连蛋白以及IV型胶原和硫酸乙酰肝素蛋白聚糖的转录水平增加。这些数据表明，新的蛋白质合成至少部分地导致了与输出小管结扎引起的组织损伤同时发生的基底膜复制。
