Canfield A E, Schor A M, Schor S L, Grant M E
Biochem J. 1986 Apr 15;235(2):375-83. doi: 10.1042/bj2350375.
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.
以往的研究表明，体外培养条件会影响牛视网膜微血管内皮细胞的形态和行为。本文呈现了关于在使细胞呈现“鹅卵石”或“出芽”表型的条件下培养的牛视网膜内皮细胞合成基质大分子的数据。通过其特征性的电泳迁移率、用特异性抗体进行免疫沉淀、对酶消化的敏感性以及色谱行为来鉴定新合成的基质蛋白。IV型前胶原是形成“鹅卵石”单层的早期传代细胞合成的主要胶原种类。相比之下，呈现“出芽”形态的细胞转而主要合成间质纤维状胶原（I型和III型）。在所有研究的实验条件下，视网膜内皮细胞都能合成纤连蛋白。一种分子量约为47,000的非胶原糖蛋白也是这些细胞的主要生物合成产物。血小板反应蛋白的合成非常依赖于细胞所培养的基质的性质。在明胶包被的培养皿上培养的“鹅卵石”内皮细胞大量合成这种糖蛋白，而在胶原凝胶上培养细胞时其合成明显减少，并且当细胞接种在胶原凝胶内（“出芽”细胞）时该蛋白似乎不存在。晚期传代的视网膜细胞主要合成I型前胶原、数量不等的III型前胶原以及仅微量的IV型前胶原，无论细胞呈现“鹅卵石”还是“出芽”形态。
