整合素诱导酪氨酸磷酸化蛋白在成纤维细胞原胶原基因表达中的作用

The role of adhesion moleculesinduced tyrosine phosphorylation proteins in procollagen expression in fibroblasts

目的：研究粘附分子整合素的细胞内信号传导途径之一——酪氨酸磷酸化在成纤维细胞表达原胶原基因中的作用。方法：利用抗整合素单抗及相应二抗的交联作用，模拟整合素在成纤维细胞表面簇集而诱导酪氨酸磷酸化，用蛋白印迹和ＲＴ－ＰＣＲ技术分别检测诱导生成的酪氨酸磷酸化蛋白和Ⅰ型原胶原ｍＲＮＡ水平；并观察阻断酪氨酸磷酸化后，酪氨酸磷酸化蛋白和Ⅰ型原胶原ｍＲＮＡ的变化。结果：整合素β１亚基在成纤维细胞表面簇集可诱导相对分子质量分别为９８０００和６５０００的酪氨酸磷酸化蛋白，且Ⅰ型原胶原ｍＲＮＡ的表达显著增加（Ｐ＜０．０１）；阻断酪氨酸磷酸化，不仅酪氨酸磷酸化蛋白显著减少（Ｐ＜０．０１），而且Ⅰ型原胶原ｍＲＮＡ的表达也降低（Ｐ＜０．０５）。结论：整合素β１亚基在成纤维细胞表面簇集诱导的酪氨酸磷酸化蛋白在Ⅰ型原胶原基因表达中具有重要作用。

Objective: To study the role of tyrosine phosphorylation in procollagen expression in fibroblasts. Methods: Tyrosine phosphorylation was induced by clustering of integrin 1 subunits, which was mimiced by means of the links of integrins on the surfaces of fibroblasts employing monoclonal antibody and the second antibody. Then proteins tyrosine phosphorylation and procollagen mRNA were detected respectively using immunoblotting and RTPCR. Besides, tyrosine phosphorylation was blocked with tyrosine kinase inhibitor, the alterations of protein tyrosine phosphorylation and procollagen were investigated. Results: Clustering of integrin 1 subunits on the surfaces of fibroblasts induced the productions of proteins tyrosine phosphorylation 98 000 and 65 000, 6 h later enhanced procollagen mRNA was also detected (P<0.01). After tyrosine phosphorylation was inhibited, procollagen 1() mRNA lowered (P<0.05) preceded by markedly diminishing of proteins tyrosine phosphorylation (P<0.01). Conclusion: Potei ns tyrosine phosphorylation induced by clustering of integrin 1 subunits on the surfaces of fibroblasts plays an important role in procollagen expression.