氧化苦参碱对醛固酮诱导大鼠心肌纤维化的作用及机制

Effect and mechanism of oxymatrine on myocardial fibrosis induced by aldosterone in rats

目的探讨氧化苦参碱(OMT)对醛固酮(ALD)诱导大鼠心肌纤维化(MF)的作用及其机制。方法40只健康雄性Sprague-Dawley(SD)大鼠随机均分为对照组、模型组、25 mg/kg OMT(低剂量)组及50 mg/kg OMT(高剂量)组,对照组大鼠予等容积生理盐水皮下注射、自由饮水,其余各组大鼠采用ALD皮下注射联合高钠盐饮水复制大鼠MF模型,持续4周,处死各组大鼠,取左心室;制作心肌组织切片,采用天狼星红染色观察各组大鼠心肌组织的胶原特点;采用碱水解法检测各组大鼠心肌羟脯胺酸(HYP)含量,采用Western blot法检测各组大鼠心肌成纤维细胞转分化(FMT)指标[Ⅰ型胶原(ColⅠ)、基质金属蛋白酶9(MMP9)、MMP2、基质金属蛋白酶抑制剂2(TIMP2)及TIMP1]水平和Notch-1信号蛋白(Jagged-1、Notch-1、DLL-4及Hes-1)表达。结果与对照组比较,模型组大鼠心肌组织见大量胶原纤维沉积、残留心肌数目少、心肌组织排列紊乱,心肌HYP含量升高(P<0.05),心肌组织中ColⅠ、MMP9、MMP2、TIMP2及TIMP1水平升高(P<0.05),Jagged-1、Notch-1、DLL-4及Hes-1蛋白表达升高(P<0.05);与模型组相比,OMT低、高剂量组大鼠心肌组织胶原减少及MMP2、TIMP2、TIMP1水平降低(P<0.05),OMT低剂量组大鼠心肌组织HYP含量、ColⅠ、MMP9水平及Jagged-1、Notch-1、DLL-4蛋白表达降低(P<0.05)。结论OMT可缓解ALD诱导的大鼠MF过程,其机制可能与下调Nothc-1信号相关蛋白的表达有关。

Objective To investigate the effect and mechanism of oxymatrine(OMT)on myocardial fibrosis(MF)of rats induced by aldosterone(ALD).Methods Fifty healthy male SD rats were randomly divided into 4 groups:the control group,the model group,the 25 mg/kg OMT(low dose)group,and the 50 mg/kg OMT(high dose)group,respectively.Rats of the control group were subcutaneously injected with equal volume of normal saline and freely drank water.Rats in other groups were reproduced models of MF by hypodermic injection of ALD with high sodium salt diet for four weeks.Rats in each group were sacrificed and left ventricles were taken.Myocardial tissue sections were made and the collagen characteristics were observed by Sirius red staining.The myocardial hydroxyproline content was determined by alkaline hydrolysis method.The fibroblast-myofibroblast transition(FMT)indexes[typeⅠcollagen(ColⅠ),matrix metalloproteinase 9(MMP9),matrix metalloproteinase 2(MMP2),tissue inhibitor of metalloproteinase 2(TIMP2),and tissue inhibitor of metalloproteinase 1(TIMP1)]and protein expression of Notch-1 signal(Jagged-1,Notch-1,DLL-4,and Hes-1)were detected by Western blot.Results Compared with the control group,a large number of collagen fibers in the model group were deposited,with fewer cardiomyocytes residues and disorganized cardiomyocytes,the content of hydroxyproline(HYP)in myocardium of rats increased significantly(P<0.05).In the model group the expression of ColⅠ,MMP9,MMP2,TIMP2,and TIMP1 significantly increased(P<0.05).and Jagged-1,Notch-1,DLL-4,and Hes-1 significantly increased too(P<0.05).Compared with the model group,myocardial collagen decreased,MMP2,TIMP2,and TIMP1 decreased significantly in OMT low and high dose groups(P<0.05).The content of HYP and the expression of ColⅠ,MMP9,Jagged-1,Notch-1,and DLL-4 decreased in OMT low dose group(P<0.05).Conclusion OMT can ameliorate ALD-induced MF of rats,and its mechanism is related to the inhibition of the protein expression of Notch-1 signal.