p42/44 MAPK介导结缔组织生长因子刺激系膜细胞合成分形素

目的检测结缔组织生长因子(CTGF)是否可诱导大鼠肾小球系膜细胞分泌趋化因子分形素(fractalkine,FLK)并探讨其作用机制。方法应用CTGF刺激培养的静息系膜细胞,在刺激后不同时间点,应用RT-PCR方法测定FLKmR-NA的表达,应用ELISA法测定系膜细胞培养上清液中FLK的水平。应用趋化试验测定系膜细胞的培养上清液对单核细胞THP-1的趋化作用。应用Western blot测定CTGF对系膜细胞中磷酸化的蛋白激酶(p42/44MAPK)表达的作用。应用p42/44MAPK抑制剂PD98059或UO126预处理,观察CTGF对该上清液中FLK分泌的影响。结果应用CTGF刺激后,系膜细胞中FLK mRNA的表达上升,其培养上清液中FLK的含量增加。抗FLK抗体可部分地阻止系膜细胞的培养上清液对单核细胞的趋化作用。CTGF可诱导p42/p44MAPK磷酸化,PD98059或UO126可抑制这一作用,并部分抑制CTGF诱导的系膜细胞培养上清液中FLK的分泌。结论CTGF可刺激系膜细胞分泌FLK,其作用机制与p42/p44MAPK的磷酸化有关。

p42/44 MAPK mediates synthesis of fractalkine by mesangial cells stimulated by connective tissue growth factor

AIM: To examine whether connective tissue growth factor (CTGF) induces the production of fractalkine (FLK) by glomerular mesangial cells of rats, and explore the mechanism of signal pathway of CTGF actions. METHODS: The mRNA expression of FLK was analyzed by RT-PCR in cultured mesangial cells stimulated by CTGF. The protein of FLK in the supernatants of cells was determined by ELISA. The chemotactic effect of the supernatants on monocytes was assessed by the in vitro chemotaxis assay. The phosphorylation of p42/44 MAPK was assessed by Western blot. RESULTS: Treatment of the cells with CTGF enhanced the mRNA expression of FLK and concentration of FLK in the supernatants. Pretreatment of the supernatants of CTGF-treated cells with anti-FLK antibodies partially inhibited the chemotactic effect of the supernatants on monocytes. CTGF increased the p42/44MAPK phosphorylation. Pretreatment of the cells with PD98059 or UO126, inhibitors of phosphorylated p42/44 MAKP, decreased the CTGF-induced expression of phosphorylated p42/44 MAPK and concentration of FLK in supernatants. CONCLUSION: CTGF-induced secretion of FLK by mesangial cells was associated with the phosphorylation of p24/p44 MAPK.[