Dreyfus M, Lahav J
Department of Polymer Research, Weizmann Institute of Science, Rehovot, Israel.
Eur J Cell Biol. 1988 Dec;47(2):275-82.
Thrombospondin (TSP) is a multifunctional protein synthesized by several cell types in culture, among them endothelial cells, and incorporated into the extracellular matrix (ECM) of these cells. In vitro it has been detected in most interstitial spaces, and its presence has been suggested to be developmentally controlled. With the aim of elucidating the role of TSP in the extracellular matrix, we studied the build-up of this protein in the matrix as a function of cell type density and age in culture. The development of the TSP matrix was compared to that of fibronectin (FN) and of von Willebrand Factor (VWF) in the same cultures using our monoclonal anti-TSP antibody B7-3 and monospecific anti-FN or anti-VWF antibodies. In cultures of bovine aortic endothelial cells (BAEC) we observed that both the pattern and distribution of TSP in the matrix changed with cell density and time in culture; it started as a completely amorphous dense layer of protein when the cells were sparse and changed to well organized fibrils when the cells had been confluent for a while. The first appearance of the fibrillar arrays of TSP coincides perfectly with that of the FN fibers; extracellular VWF also was first detected at this point. From this time in culture, there was an increasing coincidence of the TSP with the FN and the VWF matrices suggesting the formation of a complex multicomponent structure of the fibrillar network.(ABSTRACT TRUNCATED AT 250 WORDS)
血小板反应蛋白（TSP）是一种多功能蛋白，由培养中的多种细胞类型合成，其中包括内皮细胞，并整合到这些细胞的细胞外基质（ECM）中。在体外，它已在大多数间质空间中被检测到，并且其存在被认为受发育调控。为了阐明TSP在细胞外基质中的作用，我们研究了这种蛋白在基质中的积累与培养中的细胞类型密度和年龄的关系。使用我们的单克隆抗TSP抗体B7-3以及单特异性抗FN或抗VWF抗体，将同一培养物中TSP基质的发育与纤连蛋白（FN）和血管性血友病因子（VWF）的发育进行了比较。在牛主动脉内皮细胞（BAEC）培养物中，我们观察到基质中TSP的模式和分布随细胞密度和培养时间而变化；当细胞稀疏时，它开始是一层完全无定形的致密蛋白层，而当细胞汇合一段时间后，它会变成组织良好的纤维。TSP纤维状阵列的首次出现与FN纤维的出现完全吻合；此时也首次检测到细胞外VWF。从培养的这个时候起，TSP与FN和VWF基质的重合度越来越高，这表明形成了一种复杂的纤维状网络多组分结构。（摘要截于250字）
