The biosynthesis of extracellular-matrix components by bovine retinal endothelial cells displaying distinctive morphological phenotypes.
The biosynthesis of extracellular-matrix components by bovine retinal endothelial cells displaying distinctive morphological phenotypes.
复制标题
牛视网膜内皮细胞生物合成细胞外基质成分，表现出独特的形态表型。
作者：
A. Canfield;A. Schor;S. Schor;M. E. Grant
以往的研究表明，牛视网膜微血管内皮细胞的形态和行为受到体外培养条件的影响。本文介绍了牛视网膜内皮细胞在表现为“鹅卵石”或“发芽”表型的条件下生物合成基质大分子的数据。新合成的基质蛋白通过其特有的电泳迁移率、与特定抗体的免疫沉淀、对酶消化的敏感性和层析行为来鉴定。IV型前胶原是早期传代细胞合成的主要胶原蛋白，形成“鹅卵石”单层。相反，表现出发芽形态的细胞转变为主要合成间质纤维胶原蛋白(I型和III型)。在所有实验条件下，视网膜内皮细胞均可合成纤维连接蛋白。一种非胶原性糖蛋白。47,000也是这些细胞的主要生物合成产物。凝血酶原蛋白的合成在很大程度上取决于细胞培养底物的性质。这种糖蛋白是由培养在涂有明胶的培养皿上的鹅卵石内皮细胞大量合成的，而将细胞培养在胶原凝胶上后，它的合成明显减少，当细胞被培养在胶原凝胶中时，这种蛋白似乎不存在。传代后期的视网膜细胞主要合成I型前胶原，数量不一的III型前胶原，仅有少量的IV型前胶原，无论细胞是呈鹅卵石状还是发芽状。
Previous studies have indicated that the morphology and behaviour of bovine retinal microvessel endothelial cells are influenced by culture conditions in vitro. Data are presented here concerning the biosynthesis of matrix macromolecules by bovine retinal endothelial cells cultured under conditions in which the cells display either the 'cobblestone' or the 'sprouting' phenotype. Newly synthesized matrix proteins were identified by their characteristic electrophoretic mobilities, immunoprecipitation with specific antibodies, susceptibilities to enzymic digestions and chromatographic behaviour. Type IV procollagen was the major collagenous species synthesized by early-passage cells forming a 'cobblestone' monolayer. In contrast, cells displaying the 'sprouting' morphology switched to the predominant synthesis of interstitial fibrillar collagens (types I and III). Fibronectin was synthesized by retinal endothelial cells under all the experimental conditions studied. A non-collagenous glycoprotein of Mr approx. 47,000 was also a major biosynthetic product of these cells. The synthesis of thrombospondin was very much dependent on the nature of the substratum on which the cells were cultured. This glycoprotein was synthesized in large amounts by 'cobblestone' endothelial cells cultured on gelatin-coated dishes, whereas its synthesis was markedly decreased by culturing the cells on collagen gels, and the protein appeared to be absent when the cells were plated within collagen gels ('sprouting' cells). Late-passage retinal cells synthesized predominantly type I procollagen, variable amounts of type III procollagen and only traces of type IV procollagen, irrespective of whether the cells displayed a 'cobblestone' or 'sprouting' morphology.