中文摘要：

目的探索G蛋白偶联受体激酶结合蛋白1（GIT1）的RNA发夹结构对骨折愈合过程中软骨细胞分化的影响。方法按Hiltunen A方法制作闭合性大鼠左侧胫骨标准骨折模型,将40只大鼠均分成两组：对照组于骨折端注射含GIT1 WT的慢病毒;实验组骨折端注射含GIT1 RNA发夹结构（GIT1-RNAh）的慢病毒。Western blot检测蛋白表达,免疫组化法检测骨折愈合14、21 d软骨细胞内Ⅱ型胶原的表达,免疫荧光染色方法检测骨折愈合14、21 d软骨细胞的凋亡。结果对照组骨折端的骨痂内检测到GIT1蛋白的表达;而实验组骨痂内GIT1蛋白的表达明显被抑制,软骨细胞异常增生,Ⅱ型胶原的表达明显增加,软骨细胞的凋亡明显被抑制。结论 GIT1-RNAh通过降低GIT1蛋白的表达干扰了软骨细胞的分化,从而影响骨折愈合。

英文摘要：

Objective To investigate the effect of G protein coupled receptor kinase interacting protein 1（GIT1） RNA hairpin（GIT1-RNAh） on chondrocyte deffereniation during curing of fracture.Methods The bone fracture models were established according to Hiltunen A method.The mice were divided into two groups with 20 mice each.The mice in group A were injected GIT1 lentivirus as the controls and mice in group B were injected GIT1-RNAh lentivirus.The protein expression was detected by Western blot and collagen Ⅱexpression was detected by immunohistochemistry and cell apoptosis was checked with immunofluorence on the 14th and 21st day after fracture.Results GIT1 protein was expressed in fracture callus in group A.The mice in group B showed that GIT1 protein expression was inhibited in fracture callus,the collagen Ⅱexpression was significantly increased and chondrocyte apoptosis was significantly inhibited.Conclusion GIT1-RNAh interferes with chondrocyte differentiation by inhibiting GIT1 protein expression.