纤维连接蛋白在大鼠肺纤维化中的作用

Role of fibronectin in rat pulmonary fibrosis

目的 研究纤维连接蛋白 (FN)在肺纤维化中的作用。方法 用免疫组织化学方法观察实验性大鼠肺纤维化纤维连接蛋白 (FN)的动态变化 ;用Northern印迹杂交和免疫细胞化学方法分别观察FN对体外培养的大鼠肺成纤维细胞Ⅰ、Ⅲ型前胶原mRNA和蛋白表达的影响。结果 (1)实验性肺纤维化大鼠肺组织内FN的含量持续增多 ;(2 )体外培养的肺成纤维细胞经FN作用 2h ,Ⅰ、Ⅲ型前胶原mRNA的表达即增强 ,分别在 12h、6h达到最大值 ,平均吸光度 (A值 )为对照组的 1 7、3 2倍 ;Ⅰ、Ⅲ型前胶原蛋白的表达亦增强 (P <0 0 1)。抗FN受体的抗体能部分抑制FN对胶原表达的上调作用 (P <0 0 5 )。结论 FN能够促进大鼠肺成纤维细胞合成Ⅰ、Ⅲ型胶原 。

Objective To study the roles of fibronectin(FN) played in rat pulmonary fibrosis. Methods The dynamic change of FN was observed in bleomycin induced rat pulmonary fibrosis using immunohistochemical technique. Northern blot analysis and immunocytochemistry techniques were performed to detect the expression of typeⅠ,Ⅲ procollagen mRNA and their relevant proteins in cultured rat pulmonary fibrobasts(PFbs) after FN treatment. Results (1) The pulmonary tissue of rats which received bleomycin showed continuously strong positive reaction with anti FN (2) The expression of typeⅠ,Ⅲ procollagen mRNA in rat PFbs enhanced at 2 h after FN treatment,and reached their peaks at 6 h,12 h respectively The expression of typeⅠ,Ⅲ procollagen proteins detected by immunocytochemistry was also increased after the FN treatment ( P <0 01) Anti integrin α 5 monoclonal antibody could partially inhibit the effect of FN on enhancing the expression of typeⅠ,Ⅲ procollagen in PFbs ( P <0 05). Conclusions FN could up regulate the synthesis of typeⅠ,Ⅲ procollagen mainly by enhancing the transcriptions of procollagen genes