结缔组织生长因子通过活化Erk-1/2信号通路促成肌纤维细胞生成  

Connective tissue growth factor promotes the proliferation of myofibroblast through Erk-1/2 signaling pathway

作　　者：黄海长[1] 杨敏[1] 李惊子[1] 王海燕[1] 

机构地区：[1]北京大学第一医院肾脏内科北京大学肾脏病研究所,100034

出　　处：《中华医学杂志》2005年第19期1322-1326,共5页National Medical Journal of China

基　　金：国家自然科学基金资助项目(30270612);教育部教育振兴行动计划专项基金(985工程)资助项目

摘　　要：目的探讨结缔组织生长因子(CTGF)协同转化生长因子β1(TGFβ1)促进成肌纤维细胞生成分子机制。方法用TGFβ1预处理大鼠肾间质成纤维细胞(NRK49F),使部分细胞转化为成肌纤维细胞,然后将预处理后的细胞分为对照组,CTGF刺激组,TGFβ1刺激组和PD98059干预组。通过免疫细胞化学双染技术分别检测成肌纤维细胞标志蛋白α平滑肌肌动蛋白(αSMA)和掺入的细胞增殖标志物5溴2'脱氧尿嘧啶(BrdU);并以Western免疫印迹法检测αSMA水平。结果TGFβ1预处理的各组细胞都有胞浆内αSMA染色阳性,CTGF刺激组αSMA蛋白表达均明显高于对照组(P<0.05);但CTGF组部分αSMA阳性细胞核内BrdU阳性率明显高于对照组和TGFβ1组。进一步实验显示CTGF刺激细胞30min能明显诱导细胞内Erk1/2磷酸化,TGFβ1组无此反应。用PD98059阻断Erk1/2磷酸化可以明显抑制CTGF引起的细胞核内BrdU阳性表达和αSMA蛋白表达(P<0.05)。结论CTGF通过Erk1/2信号通路促进TGFβ1诱导的成肌纤维细胞增殖。Objective To investigate the mechanism by which connective tissue growth factor (CTGF) enhances transforming growth factor-β_1 (TGF-β_1)-mediated myofibroblastic activation in renal interstitial fibroblast NRK-49F. Methods NRK-49F cells were pretreated by TGF-β_1 so that some cells transform into myofibroblasts, and then the cells were devided into vechile, CTGF treated group, TGF-β_1 treated group, and PD98059 intervene group. The hallmark of myofibroblast, α-SMA immunostaining and marker of cellular proliferation, BrdU incorporation were determined by immunocytochemistry doublestaining. The protein level of α-SMA was determined by Western blot analysis. Results CTGF induced a proliferative response in myofibroblast initiated by TGF-β_1, whereas TGF-β_1 had no action on proliferation. Although CTGF could not induce myofibroblastic activation in renal interstitial fibroblast, it upregulated the protein level of α-smooth muscle actin significantly in cells pretreated by TGF-β1 (P<0.05). Significant phosphorylation of Erk-1/2 was detected after incubation with CTGF for 30 min in the cells pretreated by TGF-β_1, while TGF-β_1 did not have this ability. Inhibition of Erk-1/2 activation by Mek kinase inhibitor PD98059 suppressed CTGF-mediated myofibroblasts proliferation and significantly down-regulated expression of α-SMA protein in cells pretreated by TGF-β_1 (P<0.05). Conclusion CTGF induced a proliferative response in TGF-β_1-initiated myofibroblasts, and this action is likely dependent on the activation of Erk-1/2 signaling pathway.

关 键 词：结缔组织 生长因子 Erk-1/2 信号通路 成肌纤维细胞 

分 类 号：R363[医药卫生—病理学]