转化生长因子β1诱导肌纤维母细胞分化机制的研究  

The mechanism of transforming growth factor β1 in myofibroblast differentiation

作　　者：刘宏旭[1] 王斯闻[2] 赵成海[3] 刘洋[4] 李玉[1] 张其刚[1] 丛巍[1] 兰心刚[1] 许顺[1] 韩立波[1] 张林[1] 

机构地区：[1]中国医科大学附属第一医院胸外科,沈阳110001 [2]中国医科大学附属第四医院ICU [3]中国医科大学病理生理教研室 [4]中国医科大学病理教研室

出　　处：《中华外科杂志》2007年第14期986-989,共4页Chinese Journal of Surgery

摘　　要：目的探讨肺移植后闭塞性细支气管炎中转化生长因子β1(TGF-β1)诱导肌纤维母细胞分化的机制。方法闭塞性细支气管炎动物模型采用 Smad3野生型和基因敲除小鼠进行的同种异体异位气管移植,并采用原代培养的气管纤维母细胞,通过免疫组化、免疫荧光、Western Blotting、逆转录聚合酶链反应和 DNA 凝胶电泳迁移率检测等手段,检测肌纤维母细胞分化的标志物α平滑肌肌动蛋白(αSMA)的表达,以及 Smad3、p38和 ERK1/2的激活。结果在闭塞性细支气管炎的受累气道中,发现有αSMA 的大量表达。对纤维母细胞进行的离体研究,发现 TGF-β1诱导 Smad3激活,表现为蛋白磷酸化、细胞核转位和 DNA 结合。TGF-β1引起肌纤维母细胞分化增加,表现为αSMA 在转录和蛋白水平的表达增加;而在缺乏 Smad3的纤维母细胞中,TGF-β1诱导的肌纤维母细胞分化明显减少(t=2.080,P=0.027;t=1.982,P=0.032),但未完全消除。TGF-β1可通过激活 p38和ERK1/2来促进少量肌纤维母细胞的分化。结论 TGF-β1可通过激活 Smad3依赖性和非依赖性信号传导途径,主要是 Smad3依赖性途径,来促使纤维母细胞向肌纤维母细胞的转化,最终导致闭塞性细支气管炎的发展。Objective To investigate the mechanism underlying myofibroblast differentiation induced by transforming growth factor（TGF） β1 in obliterative bronchiolitis following lung transplantation. Methods Heterotopic tracheal transplation was performed in Smad3 wild-type and knock-out mice to simulate the lung transplantion in human. Murine tracheal fibroblasts cultivated in primary culture were used for in vitro study. Immunohistochemistry, immunocytochemistry, Western Blotting, RT-PCR and DNA eletrophoresis mobility gel shift assay were conducted to detect the expression of or-smooth muscle actin （αSMA）, the marker of fibroblast-myofibroblast differentiation, and the activation of Smad3, p38 and ERK1/2. Results In affected airways of experimental obliterative bronchiolitis, abundant expression of αSMA were found. In vitro study for tracheal fibroblasts, the activation of Smad3 by TGF-β1 presents as three major forms, phosphorylation, nuclear translocation and DNA binding. In Smad3 wild-type fibroblasts, TGF-β1 induces the increase of the myofibroblasts transformation, characterized by the elevation of otSMA, both at transcription and protein level. While in Smad3 knock-out fibroblasts, the transformation of myofibroblasts induced by TGF-β1 is significantly decreased （t = 2. 080, P = 0. 027;t = 1. 982, P = 0. 032 ）, but not completely abolished. Further study in Smad3-deficient fibroblasts demonstrates that p38 and ERK1/ 2 could be activated by TGF-β1 and result in fibroblast differentiation. Conclusions TGF-β1 could promote the transformation of fibroblasts into myofibroblasts in Smad3 dependent and independent signal pathways, especially the Smad3 dependent path, and result in the development of obliterative bronchiolitis.

关 键 词：转化生长因子Β 细支气管炎 闭塞性 肌纤维母细胞 

分 类 号：R329[医药卫生—人体解剖和组织胚胎学]