【作者】 曾靖；

【导师】 张敏州；

【作者基本信息】 广州中医药大学 ， 中西医结合临床， 2020， 博士

【摘要】 目的:确证肝X受体α(LXRα)通过抑制NOX/ROS/TNF-α信号通路改善心肌梗死后心室重构;观察脑心通胶囊通过抑制NOX/ROS/TNF-α信号通路改善心室重构和具有上调LXRα mRNA表达的作用;揭示脑心通胶囊通过上调LXRα进而抑制NOX/ROS/TNF-α信号通路从而改善心室重构。方法:1.通过冠状动脉结扎法建立急性心肌梗死大鼠模型。实验一:将大鼠随机分为假手术组、模型组、LXRα激动剂组、LXRα抑制剂组,每组8只。实验二:将大鼠随机分为假手术组、模型组、他汀组、脑心通低剂量组、脑心通中剂量组、脑心通高剂量组,每组8只。实验三:将大鼠随机分为假手术组、模型组、脑心通组、脑心通+LXRα抑制剂组,每组8只。假手术组和模型组给予生理盐水2mL/d灌胃,LXRα激动剂组给予LXRα激动剂SR9238[30mg/kg·d)]灌胃,LXRα抑制剂组给予LXRα抑制剂GSK2033[30mg/kg·d)]灌胃,他汀组给予阿托伐他汀钙片[5mg/kg·d)]灌胃,脑心通低、中、高剂量组分别给予剂量为[0.19g/kg·d)]、[0.38g/kg-d)]、[0.76g/(kg·d)]的脑心通溶液灌胃4周,脑心通+LXRα抑制剂组给予脑心通胶囊[0.38g/kg·d)]+LXRα抑制剂GSK2033[30mg/kg-d)]灌胃,时间为4周。2.检测指标:实验一、实验二、实验三4周后采用心脏彩超检查大鼠左室舒张末期内径(LVIDd)、左室收缩末期内径(LVIDs)、左室射血分数(LVEF)、短轴收缩率(FS)、每搏输出量(SV)、心输出量(CO)。HE染色观察心肌组织病理变化。Masson染色观察心肌纤维化程度。RT-QPCR检测心肌组织LXRα mRNA、还原型辅酶Ⅱ氧化酶(NOX)mRNA、活性氧(ROS)、肿瘤坏死因子-α(TNF-α)mRNA、Ⅰ型胶原(COLⅠ)mRNA、Ⅲ 型胶原(COL Ⅲ)mRNA 的表达。结果:1.实验一:①与假手术组比较,模型组和LXRα抑制剂组心脏超声示LVIDd、LVIDs显著升高(P<0.01),EF、FS、SV、CO显著降低(P<0.01),HE染色示心肌细胞大量消失、纤维结缔组织大量增生和炎性细胞浸润,masson染色示胶原纤维增生、心肌纤维化,心肌组织LXRα mRNA表达显著降低(P<0.01),NOX mRNA、ROS、TNF-α mRNA、COL Ⅰ mRNA、COL Ⅲ mRNA表达显著增加(P<0.01)。②与模型组和LXRα抑制剂组比较,LXRα激动剂组心脏超声示LVIDd、LVIDs显著降低(P<0.01),EF、FS、SV、CO显著升高(P<0.01),HE染色示纤维结缔组织显著减少,masson染色示胶原纤维显著减少,心肌组织LXRα mRNA表达显著升高(P<0.01),NOX mRNA、ROS、TNF-α mRNA、COLⅠ mRNA、COL Ⅲ mRNA表达显著降低(P<0.01)。2.实验二:①与假手术组比较,模型组和脑心通低剂量组心脏超声示LVIDd、LVIDs显著升高(P<0.01),EF、FS、SV、CO显著降低(P<0.01),HE染色示心肌细胞大量消失、纤维结缔组织大量增生和炎性细胞浸润,masson染色示胶原纤维增生、心肌纤维化,心肌织LXRαmRNA表达显著降低(P<0.01),NOX mRNA、ROS、TNF-αmRNA、COLⅠmRNA、COLⅢmRNA表达显著增加(P<0.01)。②与模型组和脑心通低剂量组比较,他汀组、脑心通中剂量组和脑心通高剂量组心脏超声示LVIDd、LVIDs显著降低(P<0.01),EF、FS、SV、CO显著升高(P<0.01),HE染色示纤维结缔组织显著减少,masson染色示胶原纤维显著减少,心肌组织LXRα mRNA表达显著升高(P<0.01),NOX mRNA、ROS、TNF-α mRNA、COLⅠ mRNA、COLⅢ mRNA 表达显著降低(P<0.01)。3.实验三:①与假手术组比较,模型组和脑心通+LXRα抑制剂组心脏超声示LVIDd、LVIDs显著升高(P<0.01),EF、FS、SV、CO显著降低(P<0.01),HE染色示心肌细胞大量消失、纤维结缔组织大量增生和炎性细胞浸润,masson染色示胶原纤维增生、心肌纤维化,心肌组织LXRαmRNA表达显著降低(P<0.01),NOX mRNA、ROS、TNF-αmRNA、COL Ⅰ mRNA、COLⅢ mRNA表达显著增加(P<0.01)。②与模型组和脑心通+LXRα抑制剂组比较,脑心通组心脏超声示LVIDd、LVIDs显著降低(P<0.01),EF、FS、SV、CO显著升高(P<0.01),HE染色示纤维结缔组织显著减少,masson染色示胶原纤维显著减少,心肌组织LXRα mRNA表达显著升高(P<0.01),NOX mRNA、ROS、TNF-α mRNA、COL Ⅰ mRNA、COL Ⅲ mRNA 表达显著降低(P<0.01)。结论:1.LXRα可以通过抑制NOX/ROS/TNF-α信号通路改善心肌梗死后心室重构。2.脑心通胶囊通过抑制NOX/ROS/TNF-α信号通路改善心室重构和具有上调LXRαmRNA表达进而改善心肌梗死后心室重构的作用。3.脑心通胶囊通过上调LXRα进而抑制NOX/ROS/TNF-α信号通路从而改善心室重构。更多还原

【Abstract】 Objective:To determine whether liver X receptor α(LXRα)can improve ventricular remodeling after myocardial infarction by inhibiting the NOX/ROS/TNF-α signal pathway;To study whether Naoxintong Capsule could improve ventricular remodeling and up-regulate LXRa mRNA expression;To study whether Naoxintong Capsule could inhibit NOX/ROS/TNF-α signaling pathway by regulating LXRa to improve ventricular remodeling.Methods:1.The rat model of acute myocardial infarction was established by coronary artery ligation Experiment 1:Rats were randomly divided into the sham operation group,model group,LXRa agonist group,and an LXRa inhibitor group,with 8 animals in each group.Experiment 2:Rats were randomly divided into the sham operation group,model group,statin group,low-dosegroup of Naoxintong,middle-dose group of Naoxintong,and high-dose group of Naoxintong,with 8 rats in each group.Experiment 3:Rats were randomly divided into the sham operation group,model group,Naoxintong group,and Naoxintong+LXRa inhibitor group,with 8 animals in each group.The sham operation group and the model group were administrated with 2ml/d saline,the LXRα agonist group was administered with LXRa agonist SR9238[30mg/(kg·d)],and the LXRa inhibitor group was administered with LXRa inhibitor GSK2033[30mg/(kg·d)],the statin group was given atorvastatin calcium tablets[5mg/(kg·d)],and the Naoxintong low,medium and high dose groups were administrated with concentrations of[0·19g/(kg·d)]、[0.38g/(kg·d)]、[0.76g/(kg·d)]Naoxintong capsule,the Naoxintong+LXRa inhibitor group was given the Naoxintong capsule at a concentration of 0.38g/kg+LXRa inhibitor GSK2033[30mg/(kg·d)]gavage for 4 weeks.2.Detection indicators:Left ventricular end diastolic diameter(LVIDd),left ventricular end systolic diameter(LVIDs),left ventricular ejection fraction(LVEF),and short-axis contraction rate(FS),Stroke volume(SV),cardiac output(CO)were checked by echocardiography.HE staining was used to observe the pathological changes of myocardial tissue.Masson staining was used to observe the degree of myocardial fibrosis;RT-QPCR was used to monitor expression of LXRα mRNA,reduced coenzyme Ⅱ oxidase(NOX)mRNA,reactive oxygen species(ROS),tumor necrosis factor-α(TNF-α)mRNA,and type Ⅰcollagen(COL Ⅰ)mRNA,type Ⅲ collagen(COL Ⅲ)mRNA in myocardial tissue.Result:1.Experiment 1:①Compared with the sham operation group,the echocardiography of the model group and the LXRa inhibitor group showed that LVIDd and LVIDs significantly increased(P<0.01),and EF,FS,SV,and CO significantly decreased(P<0.01).HE Staining showed a large number of myocardial cells disappeared,fibrous connective tissue hyperplasia and inflammatory cell infiltration.Masson staining showed collagen fibrosis,myocardial fibrosis.The expression of LXRa mRNA significantly reduced(P<0.01),expression of NOX mRNA,ROS,TNF-α mRNA,COL Ⅰ mRNA and COL Ⅲ mRNA significantly increased(P<0.01).②Compared with the model group and the LXRa inhibitor group,cardiac ultrasound in the LXRa agonist group showed significant decrease in LVIDd and LVIDs(P<0.01),a significant increase in EF,FS,SV,and CO(P<0.01).HE staining showed fibrous connectives tissues significantly reduced.Masson staining showed a significant decrease in collagen fibers.The expression of LXRa mRNA in cardiac tissue significantly increased(P<0.01),and the expression of NOX mRNA,ROS,TNF-α mRNA;COL ⅠmRNA,and COL Ⅲ mRNA significantly reduced(P<0.01).2.Experiment 2:①Compared with the sham operation group,cardiac ultrasound in the model group and the low-dose group of Naoxintong showed significant increase in LVIDd and LVIDs(P<0.01),and significant decrease in EF,FS,SV,and CO(P<0.01).HE staining showed a large number of myocardial cells disappeared,fibrous connective tissue hyperplasia and inflammatory cell infiltration.Masson staining showed collagen fibrosis,myocardial fibrosis.The expression of LXRa mRNA significantly reduced(P<0.01).The expression of NOX mRNA,ROS,TNF-α mRNA,COL Ⅰ mRNA and COL Ⅲ mRNA increased significantly(P<0.01).② Compared with the model group and low-dose group of Naoxintong,cardiac ultrasound in statin group,middle-dose,high-dose group of naoxintong group showed significant reductions in LVIDd and LVIDs(P<0.01),and significant decrease in EF,FS,SV,CO(P<0.01),HE staining showed a significant reduction in fibrous connective tissue.Masson staining showed a significant reduction in collagen fibers.The expression of LXRa mRNA significantly increased(P<0.01),expression of NOX mRNA,ROS,TNF-α mRNA,COL Ⅰ mRNA,COL Ⅲ mRNA significantly reduced(P<0.01).3.Experiment 3:①Compared with the sham operation group,cardiac ultrasound of the model group and the Naoxintong+LXRα inhibitor group showed that LVIDd and LVIDs significantly increased(P<0.01),and EF,FS,SV,and CO significantly decreased(P<0.01).HE Staining showed a large number of myocardial cells disappeared,fibrous connective tissue hyperplasia and inflammatory cell infiltration.Masson staining showed collagen fibrosis,myocardial fibrosis.The expression of LXRα mRNA significantly reduced(P<0.01).NOX mRNA,ROS,TNF-α mRNA,COL Ⅰ mRNA and COL Ⅲ mRNA significantly increased(P<0<01).②Compared with the model group and the Naoxintong+LXRαinhibitor group,cardiac ultrasound in the Naoxintong group showed significant reduction in LVIDd and LVIDs(P<0.01),significant increase in EF,FS,SV,and CO(P<0.01).HE staining showed fibrous connectives tissues significantly reduced.Masson staining showed a significant decrease in collagen fibers.The expression of LXRa mRNA in cardiac tissue significantly increased(P<0.01),and expression of NOX mRNA,ROS,TNF-α mRNA,COL Ⅰ mRNA,COL Ⅲ mRNA significantly reduced(P<0.01).Conclusion:1.LXRα could improve ventricular remodeling after myocardial infarction by inhibiting the NOX/ROS/TNF-α signaling pathway.2.Naoxintong Capsule could improve ventricular remodeling by inhibiting NOX/ROS/TNF-α signal pathway and up-regrating LXRα mRNA expression.3.Naoxintong Capsule could improve ventricular remodeling by up-regulating LXRα and inhibiting NOX/ROS/TNF-α signal pathway.更多还原