血管紧张素Ⅱ诱导被动致敏人气道平滑肌细胞合成Ⅰ型胶原

Angiotensin Ⅱ induces collagen Ⅰ synthesis in human passively sensitized airway smooth-muscle cells in vitro

目的探讨血管紧张素Ⅱ(AngⅡ)及其Ⅰ型受体(Angiotensin Type 1 Receptor,AT1R)拮抗剂洛沙坦(Losartan)对被动致敏人气道平滑肌细胞(human airway smooth muscle cells,HASMCs)合成Ⅰ型胶原的影响。方法体外培养HASMCs,按处理因素将细胞分为4组:①被动致敏组(10%哮喘血清);②被动致敏+AngⅡ组(10%哮喘血清+10-7mol/L AngⅡ);③被动致敏+Losartan组(10%哮喘血清+10-6mol/L Losartan);④被动致敏+AngⅡ+Losartan组(10%哮喘血清+10-7mol/L AngⅡ+10-6mol/L Losartan)。免疫荧光染色法鉴定HASMCs,荧光定量PCR检测Ⅰ型胶原mRNA表达,ELISA检测Ⅰ型胶原蛋白分泌。结果 10-7mol/l AngⅡ作用于被动致敏的HASMCs 24 h后,Ⅰ型胶原mRNA及蛋白的表达较被动致敏组明显增加(P<0.01)。在Losartan存在的情况下,AngⅡ对被动致敏HASMCsⅠ型胶原mRNA及蛋白表达的促进作用明显受到抑制(P<0.01)。结论 AngⅡ能促进被动致敏的HASMCs分泌Ⅰ型胶原,可能是通过与AT1R结合而实现的。

Objective To determine the effects of angiotensin（Ang） Ⅱ and losartan,an antagonist of angiotensin type 1 receptor（AT1R）,on the production of collagen type Ⅰ in human passively sensitized airway smooth muscle cells.Methods After human airway smooth muscle cells were isolated from normal bronchial tissue samples,and primarily cultured and identified by immunofluorescence staining of α-actin.The obtained cells were divided into the following 4 groups：① passively sensitized group：10% serum from asth-matic patients;② passively sensitized ＋ AngⅡ group：10% serum from asthmatic patients ＋ AngⅡ（final concentration of 10-7mol / L）;③ passively sensitized ＋ losartan group：10% serum from asthmatic patients ＋ losartan（final concentration of 10-6mol / L）;④ passively sensitized ＋ AngⅡ ＋ losartan group：10% serum from asthmatic patients ＋ AngⅡ（final concentration of 10-7mol / L） ＋ losartan（final concentration of 10-6mol / L）.The effect of AngⅡ and losartan on the collagen type Ⅰ mRNA expression in the passively sensitized HASMCs was detected by real-time RT-PCR,and its protein content was analyzed by ELISA.Results Compared to control group,the mRNA expression and protein release of collagen type Ⅰ in AngⅡ-induced group（10-7mol / L for 24 h） was significantly higher（P 0.01）.Losartan treatment produced a significantly inhibitory effect on the expression of mRNA and protein synthesis（P 0.01）.Conclusion AngⅡ induces the synthesis of collagen type Ⅰ by human passively sensitized airway smooth muscle cells,which might be through binding with AT1R.