Human keratinocytes synthesize and secrete the extracellular matrix protein, thrombospondin.
Human keratinocytes synthesize and secrete the extracellular matrix protein, thrombospondin.
复制标题
人类角质形成细胞合成并分泌细胞外基质蛋白血小板反应蛋白。
DOI：
10.1111/1523-1747.ep12525350
复制
发表时间：
1987
期刊：
影响因子：
--
通讯作者：
Clark,RA
中科院分区：
文献类型：
--
作者：
Wikner,NE;Dixit,VM;Frazier,WA;Clark,RA
血小板反应蛋白（TSP）是一种糖蛋白，最初被认为是血小板的内源性凝集素，也可由成纤维细胞、内皮细胞、肺细胞、平滑肌细胞和巨噬细胞合成。凝血反应蛋白被细分为与肝素、纤维连接蛋白、胶原蛋白和特定细胞受体特异性结合的功能域。见于肾、肺、平滑肌和皮肤的基底膜内。因此，TSP可能是细胞与基质之间的重要纽带。在表皮-真皮交界处也有血栓反应蛋白的报道。我们希望确定人角质形成细胞是否合成和分泌TSP。在没有成纤维细胞饲养层的培养基中培养纯人角质形成细胞。用兔多克隆或小鼠单克隆抗体对人血小板TSP进行免疫荧光染色，在角质形成细胞的细胞质内产生特异性的颗粒状染色。培养基和细胞裂解物从代谢标记为[35S]蛋氨酸的培养基中收获。三氯乙酸沉淀、十二烷基硫酸钠-聚丙烯酰胺凝胶电泳（SDS-PAGE）和放射自显影显示，在培养基和细胞裂解物中都有一条与纯化血小板TSP相结合的主要标记带。用多克隆或单克隆抗TSP抗体免疫沉淀，SDS-PAGE和放射自显影鉴定该条带为TSP。因此，培养的角质形成细胞合成并分泌TSP。血小板反应蛋白可能在表皮与细胞外基质的相互作用中起重要作用。
Thrombospondin (TSP) a glycoprotein originally identified as the endogenous lectin of platelets, is also synthesized by fibroblasts, endothelial cells, pneumocytes, smooth muscle cells, and macrophages. Thrombospondin is subdivided into functional domains which bind specifically to heparin, fibronectin, collagen, and to specific cellular receptors. It is found within the basement membranes of kidney, lung, smooth muscle, and skin. Thus TSP may serve as an important link between cells and matrices. Thrombospondin also has been reported at the epidermal-dermal junction. We wished to determine whether human keratinocytes synthesize and secrete TSP.Pure human keratinocytes were grown in defined medium without fibroblast feeder layers. Immunofluorescent staining with either rabbit polyclonal or mouse monoclonal antibodies to human platelet TSP yielded specific granular staining within the cytoplasm of keratinocytes. Culture media and cellular lysates were harvested from cultures metabolically labeled with [35S]methionine. Trichloroacetic acid precipitation, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and autoradiography revealed a major labeled band comigrating with purified platelet TSP in both the media and the cellular lysates. Immunoprecipitation with either the polyclonal or the monoclonal anti-TSP antibodies followed by SDS-PAGE and autoradiography identified this band as TSP. Thus keratinocytes in culture synthesize and secrete TSP. Thrombospondin may play an important role in epidermal interactions with extracellular matrix.