Cohen M P, Saini R, Klepser H, Vasanthi L G
Diabetes. 1987 Jun;36(6):758-63. doi: 10.2337/diab.36.6.758.
We examined the ability of fibronectin, an extracellular glycoprotein that interacts with cell surfaces and matrix components, to bind to glomerular basement membrane and the effect of diabetes on this binding. 125I-labeled fibronectin binding to rat glomerular basement membrane (GBM) was dose dependent, related to time and amount of basement membrane, and inhibited by unlabeled fibronectin but not by unrelated proteins. Binding was reduced approximately 60% when GBM was pretreated with collagenase and approximately 24% when pretreated with chondroitinase plus heparinase. Treatment with NaCl had little effect on binding, whereas reduction with beta-mercaptoethanol removed approximately 25% of the bound 125I-fibronectin. Binding to samples prepared from rats with streptozocin-induced diabetes was significantly increased compared with that observed with control preparations at all concentrations of fibronectin and of basement membrane tested. The findings provide direct evidence that fibronectin binds to GBM and that this binding, which represents a biologic function of the protein, is enhanced in diabetes.
我们研究了纤连蛋白（一种可与细胞表面及基质成分相互作用的细胞外糖蛋白）与肾小球基底膜结合的能力以及糖尿病对这种结合的影响。125I标记的纤连蛋白与大鼠肾小球基底膜（GBM）的结合呈剂量依赖性，与基底膜的时间和量相关，且可被未标记的纤连蛋白抑制，但不受无关蛋白质抑制。当GBM用胶原酶预处理时，结合减少约60%；用软骨素酶加肝素酶预处理时，结合减少约24%。用NaCl处理对结合影响不大，而用β-巯基乙醇处理可去除约25%结合的125I-纤连蛋白。在所有测试的纤连蛋白和基底膜浓度下，与链脲佐菌素诱导糖尿病大鼠制备的样品的结合相比对照制剂显著增加。这些发现提供了直接证据，表明纤连蛋白与GBM结合，且这种结合（代表该蛋白的一种生物学功能）在糖尿病中增强。
