Lebel Simon-Philippe, Chen Yong, Gingras Diane, Chung Albert E, Bendayan Moise
Department of Pathology and Cell Biology, Université de Montréal, CP 6128 Succ. Centre-Ville, Montreal, Quebec, Canada H3C 3J7.
J Histochem Cytochem. 2003 Nov;51(11):1467-78. doi: 10.1177/002215540305101107.
The architecture of the basement membranes is essential for proper function. This architecture is based on interactions among its components, which assemble in a complex network. Entactin-1 appears to be the mastermind of this assembling. In entactin-1-null transgenic mice, immunocytochemistry established the absence of entactin-1 in the glomerular basement membrane, and morphological thickening of this membrane was demonstrated. This prompted us to investigate the organization of other components of the glomerular basement membrane in the transgenic animals. The distribution of type IV collagen and laminin remained unchanged, whereas that of anionic charges was significantly altered. We also evaluated the impact of the absence of entactin-1 on cell relays by studying the alpha(3)- and the alpha(v)-integrins along the endothelial and epithelial glomerular cell plasma membranes. Only the density of alpha(v) was found to be increased. Finally, the filtration properties of the glomerular wall were evaluated by revealing endogenous albumin distribution across the basement membrane. This was altered in transgenic animals, suggesting changes in permselectivity properties. Entactin-1 appears to be an essential component in basement membranes because its absence appears to modify the molecular organization leading to alterations in functional properties.
基底膜的结构对于其正常功能至关重要。这种结构基于其各组成成分之间的相互作用，这些成分组装成一个复杂的网络。Entactin-1似乎是这种组装的策划者。在Entactin-1基因敲除的转基因小鼠中，免疫细胞化学证实肾小球基底膜中不存在Entactin-1，并显示该膜出现形态学增厚。这促使我们研究转基因动物中肾小球基底膜其他成分的组织情况。IV型胶原和层粘连蛋白的分布保持不变，而阴离子电荷的分布则发生了显著改变。我们还通过研究沿肾小球内皮细胞和上皮细胞质膜的α(3)-整合素和α(v)-整合素来评估Entactin-1缺失对细胞传递的影响。结果发现只有α(v)的密度增加。最后，通过揭示内源性白蛋白在基底膜上的分布来评估肾小球壁的滤过特性。转基因动物中这种分布发生了改变，表明其选择通透性特性发生了变化。Entactin-1似乎是基底膜中的一个重要成分，因为它的缺失似乎会改变分子组织，从而导致功能特性的改变。
