The interaction of keratocytes with extracellular matrix components plays an important role in the maintenance of corneal transparency and shape as well as in the healing of corneal wounds. In particular, the interaction of these cells with collagen and cell-mediated collagen contraction contribute to wound closure. Endo180 is a receptor for collagen that mediates its cellular internalization. We have now examined the role of Endo180 in collagen contraction mediated by corneal fibroblasts (activated keratocytes). Antibodies to Endo180 inhibited the contractile activity of mouse corneal fibroblasts embedded in a three-dimensional collagen gel and cultured in the presence of serum, with this effect being both concentration and time dependent and essentially complete at an antibody concentration of 0.2 μg/ml. Whereas corneal fibroblasts cultured in a collagen gel manifested a flattened morphology with prominent stress fibers under control conditions, they showed a spindlelike shape with few stress fibers in the presence of antibodies to Endo180. Antibodies to Endo180 had no effect on the expression of α-smooth muscle actin or the extent of collagen degradation in collagen gel cultures of corneal fibroblasts. Immunohistofluorescence analysis did not detect the expression of Endo180 in the unwounded mouse cornea. However, Endo180 expression was detected in keratocytes migrating into the wound area at 3 days after a corneal incisional injury. Together, our results suggest that Endo180 is required for the contraction of collagen matrix mediated by corneal fibroblasts and that its expression in these cells may contribute to the healing of corneal stromal wounds.

中文翻译：

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角膜成纤维细胞介导的胶原蛋白凝胶收缩中对胶原蛋白受体Endo180的需求。

角膜细胞与细胞外基质成分的相互作用在维持角膜透明性和形状以及在角膜伤口的愈合中起重要作用。特别地，这些细胞与胶原蛋白的相互作用和细胞介导的胶原蛋白收缩有助于伤口闭合。Endo180是胶原蛋白的受体，介导其细胞内在化。现在，我们已经检查了Endo180在角膜成纤维细胞（活化的角膜细胞）介导的胶原蛋白收缩中的作用。Endo180抗体抑制了嵌入在三维胶原蛋白凝胶中并在血清存在下培养的小鼠角膜成纤维细胞的收缩活性，这种作用是浓度和时间依赖性的，并且在抗体浓度为0.2μg/ ml时基本完成。胶原蛋白凝胶中培养的角膜成纤维细胞在控制条件下表现出扁平的形态，应力纤维突出，而在Endo180抗体存在的情况下，它们呈纺锤状形状，应力纤维很少。Endo180抗体对角膜成纤维细胞胶原蛋白凝胶培养物中的α平滑肌肌动蛋白表达或胶原蛋白降解程度没有影响。免疫组织荧光分析未检测到未受伤的小鼠角膜中Endo180的表达。然而，在角膜切口损伤后3天迁移到伤口区域的角膜细胞中检测到Endo180表达。一起，