摘要
目的探讨心阴片激活沉默信息调节因子1(SIRT1)抑制内皮间质转化(EndMT)改善慢性心力衰竭大鼠心肌纤维化的作用及机制。方法采用主动脉弓缩窄术复制压力负荷型慢性心力衰竭大鼠模型。将60只SD大鼠随机分为假手术组、模型组、心阴片低剂量组(0.315 g·kg^(-1))、心阴片中剂量组(0.63 g·kg^(-1))、心阴片高剂量组(1.26 g·kg^(-1))、EX527组[1.26 g·kg^(-1)心阴片+5 mg·kg^(-1)EX527(SIRT1抑制剂)],每组10只。各给药组按照上述设定剂量灌胃给药,每天1次,连续8周。采用超声心动图检测大鼠心功能,包括左室射血分数(LVEF)、左室短轴缩短率(LVFS)、舒张末期左室内径(LVIDd)、收缩末期左室内径(LVIDs)等心功能指标;HE、Masson染色法观察大鼠心肌组织病理变化,分析心肌组织的胶原纤维相对面积占比;Western Blot法检测心肌组织相关蛋白的表达水平;qRT-PCR法检测心肌组织相关基因的表达水平。结果与假手术组比较,模型组大鼠的LVEF、LVFS水平明显降低(P<0.05),LVIDd、LVIDs水平明显升高(P<0.05);心肌细胞增大,并有大量的炎性细胞浸润,肌原纤维紊乱,胶原纤维沉积增多,胶原纤维相对面积占比明显升高(P<0.05);心肌组织CollagenⅠ、CollagenⅢ蛋白表达量明显增加(P<0.05),SIRT1、CD31、VE-cadherin蛋白表达明显下调(P<0.05),α-SMA、FSP1、TGF-β1、p-Smad2/3蛋白表达明显上调(P<0.05);心肌组织SIRT1、VE-cadherin mRNA表达明显下调(P<0.05),α-SMA、TGF-β1、Smad2/3 mRNA表达明显上调(P<0.05)。与模型组比较,心阴片中、高剂量组大鼠的LVEF、LVFS水平明显升高(P<0.05),心肌组织CD31、VE-cadherin蛋白表达明显上调(P<0.05),α-SMA、FSP1蛋白表达明显下调(P<0.05)。心阴片各剂量组大鼠的LVIDd、LVIDs水平明显降低(P<0.05);心肌细胞明显缩小,炎性细胞浸润及胶原纤维沉积明显减轻,胶原纤维相对面积占比明显降低(P<0.05);心肌组织CollagenⅠ、CollagenⅢ蛋白表达量明显减少(P<0.05),SIRT1蛋白表达明显上调(P<0.05),TGF-β1、p-Smad2/3蛋白表达明显下调(P<0.05);心肌组织SIRT1、VE-cadherin mRNA表达明显上调(P<0.05),α-SMA、TGF-β1、Smad2/3 mRNA表达明显下调(P<0.05)。与模型组比较,EX527组大鼠的心功能、心肌组织病理变化及其他检测指标均无明显变化(P>0.05)。结论心阴片能够有效防治慢性心力衰竭大鼠的心肌纤维化,明显改善其心功能,其机制可能是通过激活SIRT1调控TGF-β1/Smad2/3信号通路,从而抑制EndMT的发生。
Objective To investigate the effect and mechanism of Xinyin Tablets(XYT)in ameliorating myocardial fibrosis in rats with chronic heart failure(CHF)by activating sirtuin 1(SIRT1)to inhibit endothelial-mesenchymal transition(EndMT).Methods A pressure overload-induced CHF rat model was established by transverse aortic constriction.Sixty SD rats were randomly divided into six groups(n=10 per group):sham-operated group,model group,low-dose XYT group(0.315 g·kg^(-1)),medium-dose XYT group(0.63 g·kg^(-1)),high-dose XYT group(1.26 g·kg^(-1)),and EX527 group(1.26 g·kg^(-1)XYT+5 mg·kg^(-1)EX527,a SIRT1 inhibitor).Drugs were administered daily by gavage for 8 consecutive weeks.Echocardiography was used to assess cardiac function,including left ventricular ejection fraction(LVEF),fractional shortening(LVFS),left ventricular internal dimension at end-diastole(LVIDd),and left ventricular internal dimension at end-systole(LVIDs).Myocardial pathological changes were observed via HE and Masson staining,and the relative collagen fiber area was calculated.The expression levels of related proteins and genes in myocardial tissue were detected by Western Blot and qRT-PCR,respectively.Results Compared with the sham-operated group,the model group showed significantly decreased LVEF and LVFS(P<0.05),and increased LVIDd and LVIDs(P<0.05).Myocardial cells were enlarged with significant inflammatory cell infiltration,disorganized myofibrils,increased collagen deposition,and a significantly elevated relative collagen fiber area(P<0.05).Protein expression of CollagenⅠand CollagenⅢwas increased(P<0.05),while SIRT1,CD31,and VE-cadherin protein expression was downregulated(P<0.05).Protein expression ofα-SMA,FSP1,TGF-β1,and p-Smad2/3 was upregulated(P<0.05).mRNA expression of SIRT1 and VE-cadherin was downregulated(P<0.05),whileα-SMA,TGF-β1,and Smad2/3 mRNA expression was upregulated(P<0.05).Compared with the model group,the medium-and high-dose XYT groups exhibited significantly increased LVEF and LVFS(P<0.05),upregulated protein expression of CD31 and VE-cadherin(P<0.05),and downregulated protein expression ofα-SMA and FSP1(P<0.05).All XYT dose groups showed significantly decreased LVIDd and LVIDs(P<0.05),reduced myocardial cell size,alleviated inflammatory infiltration,decreased collagen deposition,and a significantly reduced relative collagen fiber area(P<0.05).Protein expression of Collagen I and CollagenⅢwas decreased(P<0.05),SIRT1 expression was upregulated(P<0.05),and TGF-β1 and p-Smad2/3 expression was downregulated(P<0.05).mRNA expression of SIRT1 and VE-cadherin was upregulated(P<0.05),whileα-SMA,TGF-β1,and Smad2/3 mRNA expression was downregulated(P<0.05).No significant changes were observed in cardiac function,myocardial histopathological changes and other detected indicators in the EX527 group compared with the model group(P>0.05).Conclusion XYT can effectively prevent and treat myocardial fibrosis and significantly improve cardiac function in rats with CHF.Its mechanism may involve activating SIRT1 to regulate the TGF-β1/Smad2/3 signaling pathway,thereby inhibiting EndMT.
作者
李巧
褚庆民
叶桃春
刘树林
刘敏
LI Qiao;CHU Qingmin;YE Taochun;LIU Shulin;LIU Min(The First Affiliated Hospital of Guangzhou University of Chinese Medicine/Guangdong Clinical Research Academy of Chinese Medicine,Guangzhou 510405 Guangdong,China;The First School of Clinical Medicine,Guangzhou University of Chinese Medicine,Guangzhou 510405 Guangdong,China)
出处
《中药新药与临床药理》
北大核心
2026年第2期199-207,共9页
Traditional Chinese Drug Research and Clinical Pharmacology
基金
国家自然科学基金青年科学基金项目(82205236)
广东省中医药局科研项目(20231099)。
