丹参酮Ⅱ_A对心衰心室重构I型胶原基因启动子活性的影响

Influence of tanshinone Ⅱ_A on activity of promoter of α1(I) collagen gene in ventricular remodeling of heart failure

目的探讨心衰心室重构中血管紧张素Ⅱ(AngⅡ)对人α1(Ⅰ)胶原基因启动子活性的调控作用和中药单体丹参酮ⅡA(tanshinoneⅡA,TSN)药物干预的影响环节。方法将人α1(I)胶原基因上游-2.5 Kb长度的启动子片段与氯霉素乙酰基转移酶(CAT)报告基因组成重组体pCOLH2.5,采用脂质体法转染至培养的大鼠心肌成纤维细胞和ELISA法测定CAT活性的方法,观察不同浓度TSN对pCOLH2.5活性及由AngⅡ诱导的pCOLH2.5活性的影响。结果AngⅡ可剂量依赖性地促进pCOLH2.5的活性,表现为其剂量增大时重组体CAT活性相对增加,与对照组比较有显著性差异(P<0.05)。TSN能抑制pCOLH2.5的活性,并随着药物浓度的增加,其抑制作用亦增强。与对照组、低浓度组比较,差异有显著性(P<0.05)。而且在与AngⅡ共同作用时,pCOLH2.5 CAT的升高幅度明显减少(P<0.01)。结论在心肌成纤维细胞中,AngⅡ具有促进人α1(Ⅰ)胶原基因启动子的转录活性作用。TSN能下调人α1(Ⅰ)胶原基因启动子的激活,并可部分拮抗AngⅡ的促进作用。

Objective ObjectiveTo study the regulation of angiotensin Ⅱ （AngⅡ） on promoter aαivity of human α 1 （Ⅰ） collagen gene and the interferential effeα of tanshinone Ⅱ A （TSN） in the ventficular remodeling of heart failure. Methods To compose a recombinant-pCOLH2.5 from the upstream of the promoter fragments of 2. 5Kb in length of human α 1 （Ⅰ） collagen gene and chloramphenicol acetyhransferase （CAT）. To observe the influence of TSN at different concentrations on pCOLH2.5 aαivity and the pCOLH2.5 aαivity induced by AngⅡ through the elaioplast transfection to cultured rat myocardial fibroblasts and ELISA technique for detection of CAT aαivity. Results AngⅡ promoted the activity of pCOLH2.5 in dose - dependent manner. The aαivity of CAT in pCOLH2.5 increased along with the dose of AngⅡ raise, which was significantly different compared with the control group （P 〈 0. 05）. TSN could inhibit the activity of pCOLH2.5 and its inhibitory effect increased along with its concentration （P 〈0.05 ）. （P〈0. 01）. in myocardial gene and has raise, which was significantly different compared with the control group and low-dose group The joint effect of AngⅡ and TSN could inhibit the raising range of CAT in pCOLH2.5 Conclusion AngⅡ can improve the transcription activity of human α 1 （Ⅰ） collagen gene fibroblasts, while TSN can inhibit the activation of the promoter of human α 1 （Ⅰ） collagen an antagonism to AngⅡ partially.