气道上皮损伤后支气管上皮-肌纤维母细胞转分化及转化生长因子β1的调节作用  

Epithelial-mesenchymai transition in injured bronchial epithelial cells and regulation by transforming growth factor-β1

作　　者：蔡闯[1] 徐军[1] 张敏[1] 钟南山[1] 

机构地区：[1]广州医学院第一附属医院广州呼吸疾病研究所,510120

出　　处：《国际呼吸杂志》2009年第10期577-581,F0003,共6页International Journal of Respiration

基　　金：国家自然科学基金资助项目（30230180）

摘　　要：目的观察支气管上皮细胞损伤后，细胞表型、超微结构、内皮素1（endothelin-1，ET-1）、转化生长因子β1（transforming growth factor-β1，TGF-β1）表达的动态变化以及TGF-β1对支气管上皮-肌纤维母细胞转分化（epithelial-mesenchymal transition，EMT）的调节。方法以多聚左旋精氨酸（PA）诱导支气管上皮16HBE-140细胞损伤，观察损伤后细胞培养液ET-1、T,GF-β1及乳酸脱氢酶（LDH）含量、细胞表型及超微结构的动态改变，ET-1对上皮细胞TGF-β1分泌的调节以及TGF-β1对EMT的促进作用。结果PA造成16HBE-140损伤，损伤后LDH、ET-1、TGF-β1释放增多。上皮修复过程中，一过性出现少量肌动蛋白阳性的细长梭形细胞，胞浆内同时可见肌微丝及丰富的粗面内质网，梭形细胞周围可见新分泌的胶原纤维，发生EMT。50μg／LTGF-β1能促进损伤上皮细胞的EMT，TGF-β1中和抗体能完全阻断EMT。ET-1能刺激上皮细胞分泌TGF-β1，且为ET-1A受体阻断剂-bq123完全阻断。结论支气管上皮细胞损伤后ET-1、TGF-β1表达上调，出现上皮一间充质转分化。TGF-β1能通过自分泌、旁分泌作用促进EMT。ET-1可能通过上调上皮细胞TGF-β1的表达参与EMT的调节。气道上皮损伤后上皮细胞的活化、EMT可能在支气管哮喘气道重塑中发挥重要作用。Objective To study phenotypic, ultrastructural changes, and releasing of endothelin-1 （ET-1） and transforming growth factor-β1 （TGF-β1 ） following bronchial epithelial injury, and to investigate the regulation of epithelial-mesenchymal transition（EMT） during epithelial restitution by TGF-β1. Methods Bronchial epithelial injury was induced by poly-L-arginine （PA） in 16HBE 14o cell line. ET-1, TGF-β1, lactate dehydrogenase （LDH） content in conditioned culture medium, phenotypic and ultrastructural changes were monitored dynamically along with the regulation of EMT during epithelial repair by TGF-β1. Results PA elicited epithelial injury in 16HBE 14o cells with elevation of LDH,increased releasing of ET-1 and TGF-β1 by injured epithelial cells. Transient EMT occurred during epithelial restitution, evidenced by emergence of spindle-shaped, a smooth actin immunostaining cells with stress microfilaments and enriched rough endoplasmie reticulum as well as newly-secreted collagen fibers. Co-incubation with 50 μg/L TGF-191 promoted EMT whereas TGF-β1 neutralizing antibody abrogated the transition. ET-1 stimulated epithelial release of TGF-β1 ,which was completely blocked by ET-1 receptor A antagonist,bq123, Conclusions There was overexpression of ET-1, TGF-β1 and transient EMT following bronchial epithelial injury. EMT was driven by TGF-β1 in autocrine/paracrine pattern. ET-1 possibly participated in EMT through stimulating epithelial release of TGF-β1. Epithelial activation and EMT following epithelial injury might play crucial roles in the pathogenesis of airway remodeling in bronchial asthma.

关 键 词：上皮细胞损伤 肌纤维母细胞 转化生长因子β1内皮素 

分 类 号：R5[医药卫生—内科学]