血管紧张素Ⅱ对大鼠HSCs分泌ECM影响机制的研究

Effects of angiotensin Ⅱ on ECM secretion of HSCs in rats

目的探讨血管紧张素Ⅱ（AngⅡ）刺激大鼠肝脏星状细胞（HSCs）分泌细胞外基质（ECM）的可能机制。方法采用胶原酶原位循环灌流法分离大鼠肝星状细胞（HSCs）。①用不同浓度AngⅡ（10^-9～10^-5 mol／L）处理HSCs，酶联免疫吸附法检测各组HSCs层黏蛋白（LN）、透明质酸（HA）、Ⅲ型前胶原（PcⅢ）和Ⅳ型胶原（CⅣ）水平。以未经AngⅡ处理的HSCs作为对照组。②选择使ECM分泌显著增加的AngⅡ处理组HSCs，抽提RNA后采用RT-PCR技术测定转化生长因子-β1（TGF—β1）和结缔组织生长因子（CTGF）mRNA表达，并与新鲜分离的大鼠HSCs和对照组HSCs进行比较。结果与对照组比较，AngⅡ各浓度处理组HSCs的LN和HA分泌水平均明显增加（P〈0．01），且呈剂量依赖关系；AngⅡ10^-7～10^-5 mol／L处理组HSCs的PcⅢ和CⅣ分泌水平也显著增加（P〈0．01）。RT—PCR检测结果显示，与新鲜分离大鼠和对照组HSCs比较，有较高ECM分泌水平的10μmol／L AngⅡ处理组HSCs的TGF—β1和CTGF mRNA表达水平明显升高。结论AngⅡ能刺激大鼠HSCs分泌ECM，其通过促进TGF—β1表达经CTGF介导而参与肝脏纤维化的发生。

Objective To explore the the mechanism secretion of hepatic stellate cells （HSCs） in rats of angiotensinⅡ （AngⅡ） in promoting extracellular matrix （ECM） Methods HSCs were isolated by using collagenase in situ liver recirculating perfusion. （1）Some components of ECM secreted by HSCs including laminin （LN）, hyaluronic acid （HA）, procollagen Ⅲ （Pc Ⅲ）and collageniv （CⅣ） were detected by ELISA method after stimulation by different doses of AngⅡ （10^-9 -10^-5 mol/L）. HSCs without stimulation were served as control. （2）The HSCs of AngⅡ which could increase ECM secretion were selected and then RNA was extracted. The expression of transforming growth factor-β1 （TGF-β1 ） and connective tissue growth factor （CTGF） mRNA was detected by RT-PCR, and was compared with that isolated and activated in culture and controls. Results Compared with control group, the levels of LN and HA of of HSCs significantly increased in a dosedependent manner after stimulation by Ang Ⅱ with different concentrations（P 〈 0.01 ）. The levels of PC Ⅲ and C Ⅳ of HSCs also significantly increased after stimulation by 10^-7 - 10^-5 mol/L Ang Ⅱ （P 〈0.01）. It was revealed by RT-PCR that the expression of TGF-β1 and CTGF mRNA significantly increased after stimulation by 10^-6 mol/L Ang Ⅱ , compared with that isolated and activated in culture and controls. Conclusion Ang Ⅱ can stimulate ECM secretion of HSCs in rats. Ang Ⅱ participates in hepatic fibrosis by enhancing the expressions of TGF-β1 and CTGF.