Masur S K, Conors R J, Cheung J K, Antohi S
Department of Ophthalmology, Mount Sinai School of Medicine of the City University of New York, NY 10029-6574, USA.
Invest Ophthalmol Vis Sci. 1999 Apr;40(5):904-10.
To investigate the adhesion characteristics of corneal myofibroblasts in a cell culture model.
Immunocytochemistry, immunoprecipitation, western blot analysis, and attachment assays were used to evaluate matrix adhesion characteristics of myofibroblasts.
Myofibroblasts, defined by their expression of the smooth muscle isoform of alpha-actin, were evaluated and compared with fibroblasts. Myofibroblasts had larger vinculin-containing focal adhesions and expressed more of the classic fibronectin receptor (FNR) alpha5beta1 per cell. However, myofibroblasts had less surface expression of the higher molecular weight alpha4 subunit of another FNR, alpha4beta1, than did fibroblasts. Myofibroblasts adhered more avidly in an integrin-dependent manner to fibronectin than did fibroblasts. The attachment to fibronectin was actin-dependent for both phenotypes, but the myofibroblasts' adhesion was more resistant to disruption by cytochalasin than were fibroblasts'. In addition to the previously described expression of a 135-kDa classic cadherin, myofibroblasts also expressed a 115-kDa mesenchymal cadherin, cadherin-11.
Differentiation of corneal fibroblasts into myofibroblasts is associated with characteristics that would indicate that the latter have a special role in wound closure. The increase in focal and cell adhesion molecules that accompanies smooth muscle-specific actin expression provides the basis for the myofibroblasts' enhanced cell-fibronectin and cell-cell adhesion.
在细胞培养模型中研究角膜肌成纤维细胞的黏附特性。
采用免疫细胞化学、免疫沉淀、蛋白质印迹分析和黏附试验来评估肌成纤维细胞的基质黏附特性。
对通过α-肌动蛋白平滑肌异构体表达定义的肌成纤维细胞进行评估，并与成纤维细胞进行比较。肌成纤维细胞含有更大的含纽蛋白的黏着斑，且每个细胞表达更多的经典纤连蛋白受体（FNR）α5β1。然而，与成纤维细胞相比，肌成纤维细胞另一种FNR即α4β1的高分子量α4亚基的表面表达较少。与成纤维细胞相比，肌成纤维细胞以整合素依赖的方式更强烈地黏附于纤连蛋白。两种表型对纤连蛋白的黏附均依赖于肌动蛋白，但肌成纤维细胞的黏附比成纤维细胞的黏附更能抵抗细胞松弛素的破坏。除了先前描述的135 kDa经典钙黏蛋白的表达外，肌成纤维细胞还表达一种115 kDa间充质钙黏蛋白，即钙黏蛋白-11。
角膜成纤维细胞向肌成纤维细胞的分化与一些特性相关，这些特性表明后者在伤口愈合中具有特殊作用。伴随平滑肌特异性肌动蛋白表达的黏着斑和细胞黏附分子的增加为肌成纤维细胞增强的细胞-纤连蛋白和细胞-细胞黏附提供了基础。
