牡荆素调控Epac1/CaMKⅡ通路减轻小鼠急性心肌缺血再灌注损伤的作用机制  

Protective effect and mechanism of vitexin regulating Epac1/CaMKⅡpathway on acute myocardial ischemia reperfusion injury in mice

作　　者：甘琴 杨换花 张玲玉 刘小嘉 董六一 Gan Qin;Yang Huanhua;Zhang Lingyu;Liu Xiaojia;Dong Liuyi(Dept of Pharmacology,School of Basic Medicine,Anhui Medical University,Hefei 230032;Dept of Basic Medicine,Hefei Technology College,Hefei 230012)

机构地区：[1]安徽医科大学基础医学院药理学教研室,合肥230032 [2]合肥职业技术学院基础医学教研室,合肥230012

出　　处：《安徽医科大学学报》2023年第10期1652-1656,共5页Acta Universitatis Medicinalis Anhui

基　　金：安徽省自然科学基金(编号:2108085MH254);安徽省高等学校自然科学研究项目(编号:KJ2021A1387)。

摘　　要：目的研究小鼠心肌缺血再灌注损伤(MIRI)中Epac1/CaMKⅡ信号通路的作用,并探明牡荆素(VT)对急性MIRI的保护作用。方法取C57/BL小鼠随机分为5组,每组8只,分别为假手术组(Sham组),缺血再灌注组(I/R组),缺血再灌注+VT组(VT设置3、6、12 mg/kg 3个剂量组)。小鼠左冠状动脉前降支(LAD)结扎,使部分心脏组织缺血30 min,血液再灌注120 min,构建小鼠MIRI模型。Sham组小鼠只手术不结扎LAD。检测小鼠血清中乳酸脱氢酶(LDH)水平;取小鼠左室心肌组织进行HE染色观察心肌病理组织学变化;免疫组织化学观察心肌组织中Epac1的表达水平;Western blot法测定Epac1、Rap1、CaMKⅡ、ERK/p-ERK蛋白表达的变化。结果与Sham组比较,I/R组小鼠血清中LDH百分比水平显著升高,心肌组织中Epac1、Rap1、CaMKⅡ蛋白表达显著上调,ERK1/2磷酸化水平降低。与I/R组比较,VT(3、6、12 mg/kg)预处理组可显著降低小鼠血清中LDH水平,抑制小鼠心肌组织中Epac1、Rap1与CaMKⅡ蛋白表达,促进ERK1/2磷酸化。病理组织学结果显示,I/R组小鼠心肌纤维排列紊乱、断裂,间隙增加,炎性细胞浸润明显;VT(3、6、12 mg/kg)预处理组小鼠心肌纤维排列较整齐,炎性细胞浸润较少。结论VT可能通过调节Epac1/CaMKⅡ信号通路,下调CaMKⅡ蛋白表达,促进ERK磷酸化,有效减轻MIRI。Objective To investigate the role of Epac1/CaMKⅡsignaling pathway in myocardial ischemia reperfusion injury(MIRI)in mice,and to investigate the protective effect of vitexin(VT)on acute MIRI.Methods C57/BL mice were randomly divided into 5 groups:Sham surgery group(Sham),ischemia reperfusion group(I/R),and ischemia reperfusion+vitexin group(function 3,6,12 mg/kg groups).Ligation of the left anterior descending coronary artery(LAD coronary artery)in mice resulted in ischemia of part of the heart tissue for 30min and reperfusion of the blood for 120min.Mouse myocardial ischemia reperfusion injury(MIRI)model was established.In the sham operation group,only the LAD was not ligated.Serum LDH levels of mice were detected.Hematoxylin-eosin(H&E)staining was performed on the left ventricular myocardium of mice to observe the histopathological changes.The expression level of Epac1 in myocardial tissue was observed by immunohistochemistry.The protein expressions of Epac1,Rap1,CaMKⅡand ERK/p-ERK were determined by Western Blot.Results Compared with Sham group,serum LDH level of mice in I/R group was significantly increased,protein expressions of Epac1,Rap1 and CaMKⅡin myocardial tissue were significantly up-regulated,and ERK1/2 phosphorylation level was decreased.Compared with I/R group,vitexin(3,6,12 mg/kg)pretreatment group decreased serum LDH level,inhibited Epac1,Rap1 and CaMKⅡprotein expression in mouse myocardial tissue,and promoted ERK1/2 phosphorylation(P<0.05 or P<0.01).The histopathological results showed that the myocardial fibers in the I/R group were disordered and broken,with increased gaps and obvious inflammatory cell infiltration.In the vitexin treatment group,the myocardial fibers were arranged more neatly and inflammatory cells were infiltrated less.Conclusion Vitexin may regulate Epac1/CaMKⅡsignaling pathway,down-regulate CaMKⅡprotein expression,increase ERK phosphorylation,and effectively reduce MIRI.

关 键 词：牡荆素 Epac1 CaMKⅡ 心肌缺血再灌注损伤 

分 类 号：R285.5[医药卫生—中药学]