SYNTHESIS OF FIBRONECTIN BY CULTURED HUMAN ENDOTHELIAL CELLS
SYNTHESIS OF FIBRONECTIN BY CULTURED HUMAN ENDOTHELIAL CELLS
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DOI：
10.1084/jem.147.6.1779
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发表时间：
1978-01-01
影响因子：
15.3
通讯作者：
MOSHER, DF
中科院分区：
文献类型：
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作者：
JAFFE, EA;MOSHER, DF
血浆纤维连接蛋白可能是血液中主要的非免疫颗粒性调理蛋白，在血液凝固的最后阶段与纤维蛋白交联。纤维连接蛋白也以不溶性形式存在于基底膜中，特别是内皮细胞下层和松散结缔组织中。利用人血浆纤维连接蛋白抗体，在免疫荧光显微镜下发现在培养的人内皮细胞及其周围的细胞外基质中存在纤维连接蛋白。培养的人内皮细胞将纤维连接蛋白释放到与人血浆中纤维连接蛋白免疫相同的培养基中。培养的人内皮细胞用[3H]亮氨酸标记。采用抗纤维连接蛋白偶联蛋白A-Sepharose或双抗体免疫沉淀法分离内皮细胞培养后培养基和细胞单层尿素提取物中的放射性纤维连接蛋白，并用十二烷基硫酸钠-聚丙烯酰胺凝胶电泳对其进行鉴定。体外培养的内皮细胞合成的[3H]纤维连接蛋白在还原后具有相同的分子量（.apprx）。20万)作为血浆纤维连接蛋白。未还原时，内皮细胞合成的[3H]纤维连接蛋白作为二聚体迁移，血浆纤维连接蛋白也是如此。纤维连接蛋白约占0.75%。内皮细胞合成并释放15%的蛋白质到培养基中。培养的内皮细胞合成纤维连接蛋白，将其分泌到培养基中，并结合到细胞外基质中。内皮细胞可能是循环血浆纤维连接蛋白合成的主要部位。来源于内皮细胞的纤维连接蛋白可能是内皮下层的重要结构成分。
Plasma fibronectin is probably the major nonimmune particulate opsonin in blood and is cross-linked to fibrin during the final stage of blood coagulation. Fibronectin also occurs in an insoluble form in basement membranes especially those underlying endothelial cells and in loose connective tissue. Fibronectin was demonstrated in cultured human endothelial cells and in the surrounding extracellular matrix by immunofluorescence microscopy by using antibody to human plasma fibronectin. Cultured human endothelial cells released fibronectin into the culture medium which was immunologically identical to the fibronectin in human plasma. Cultured human endothelial cells were labeled with [3H] leucine. The radioactive fibronectin in the endothelial postculture medium and in urea extracts of cellular monolayers was isolated with anti-fibronectin coupled to Protein A-Sepharose or double antibody immunoprecipitation and characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. When reduced, the [3H] fibronectin synthesized by cultured endothelial cells had the same MW (.apprx. 200,000) as plasma fibronectin. Unreduced, the [3H] fibronectin synthesized by endothelial cells migrated as a dimer, as did plasma fibronectin. Fibronectin accounted for .apprx. 15% of the protein synthesized and released by endothelial cells into the culture medium. Cultured endothelial cells synthesized fibronectin, secreted it into the culture medium, and incorporated it into extracellular matrix. The endothelial cell may be a major site of synthesis of circulating plasma fibronectin. Fibronectin derived from endothelial cells may be an important structural component of the subendothelium.