为探究膜联蛋白A1(Annexin A1,ANXA1)拟肽Ac2-26对急性心力衰竭(acute heart failure,AHF)模型大鼠的血流动力学与心肌线粒体损伤的影响及作用机制,将研究对象分为对照组、模型组和Ac2-26组(每组15只大鼠),模型组和Ac2-26组大鼠构建AHF模型,且Ac2-26组静脉输注Ac2-26,对照组和模型组静脉输注等体积生理盐水,1次/d,连续14 d.彩色多普勒超声仪检测各组大鼠的血流动力学指标变化;H-E染色观察各组大鼠的心肌组织病理学损伤情况;TUNEL染色观察各组大鼠心肌细胞的凋亡情况;透射电子显微镜观察各组大鼠的心肌线粒体结构;线粒体分离试剂盒分离各组大鼠心肌组织线粒体,JC-1染色观察线粒体膜电位变化;免疫组织化学染色观察各组大鼠心肌组织巨噬细胞标志物CD68、M1型巨噬细胞标志物iNOS与M2型巨噬细胞标志物CD206的表达;实时荧光定量PCR检测各组大鼠心肌组织中TNF-α、IL-6、TGF-β、IL-10及重组人精氨酸酶1(Arginase 1,Arg-1)的mRNA相对表达量;Western blotting检测各组大鼠心肌组织中IL-10、Arg-1和CD206的蛋白表达水平.与模型组比较,Ac2-26组大鼠左心室收缩压(left ventricular systolic pressure,LVSP)与 + 左心室内压最大上升速率(maximum increase rate of left ventricular pressure,+LV dp/dtmax)均升高,左心室舒张末压(left ventricular end-diastolic pressure,LVEDP)与-左心室内压最大下降速率(maximum decrease rate of left ventricular pressure,-LV dp/dtmax)均下降,心率(heart rate,HR)升高;心肌组织中心肌细胞数较多,细胞间隙缩小,炎症细胞和巨噬细胞浸润现象明显减轻;TUNEL染色阳性率下降,心肌细胞线粒体损伤减轻、结构相对完整,线粒体膜电位升高;心肌组织中iNOS阳性表达减少,而CD68和CD206的阳性表达均增加;TNF-α、IL-6的mRNA相对表达量均下调,TGF-β、IL-10和Arg-1的mRNA相对表达量均上调;同时,IL-10、Arg-1和CD206的蛋白表达水平也均上调.由此,Ac2-26可以改善AHF大鼠的血流动力学状态,减轻心肌细胞线粒体的损伤,该作用可能与促进巨噬细胞向抑炎性M2型极化有关.
Ac2-26-induced macrophage polarization from M1 to M2 regulates hemo-dynamics and mitochondrial damage in acute heart failure rats
To explore the effect and mechanism of Annexin A1(ANXA1)peptidomimetic Ac2-26 on hemodynamics and myo-cardial mitochondrial damage in the acute heart failure(AHF)model,rats were divided into control group,model group,and Ac2-26 group(fifteen rats per group).AHF model was established in the model group and Ac2-26 group.Rats in Ac2-26 group were also intravenously injected with Ac2-26 once a day for fourteen days,whereas the control group and model group were treated with the same volume of saline.Color doppler ultrasound was used to detect the hemodynamic indexes.H-E staining was used to evaluate the pathological damage of myocardial tissue.TUNEL staining was used to detect the apoptosis of cardio-myocytes.Transmission electron microscope(TEM)was used to observe the mitochondrial structure.Changes in mitochondrial membrane potential were also evaluated.Macrophage marker CD68,M1 marker iNOS,and M2 marker CD206 were detected by immunohistochemistry.mRNA expressions of TNF-α,IL-6,TGF-β,IL-10 and recombinant human Arginase 1(Arg-1)and protein expression levels of IL-10,Arg-1 and CD206 were evaluated by qRT-PCR and Western blotting,respectively.Compared with the model group,the left ventricular systolic pressure( LVSP)and maximum increase rate of left ventricular pressure( + LV dp/dtmax)of rats in the Ac2-26 group were increased,left ventricular end-diastolic pressure(LVEDP)and maximum decrease rate of left ventricular pressure( - LV dp/dtmax)were decreased,and heart rate( HR)was increased; The number of cardiomyocytes in the myocardial tissue was large,and the inter-cellular space was narrowed,and the infiltration of inflammatory cells and macrophages was also relieved; The positive rate of TUNEL staining was decreased,the damage of myocardial mitochondria was relieved,the structure was relatively intact,and the mitochondrial membrane potential was increased; The positive expression of iNOS in myocardial tissue was decreased,and the positive expressions of CD68 and CD206 were increased; The relative mRNA expressions of TNF-α and IL-6 were both down-regulated,while those of TGF-β,IL-10 and Arg-1 were all up-regulated.Meanwhile,the protein levels of IL-10,Arg-1,and CD206 were also up-regulated,and all the differences were statistically significant(all P＜0.05).In conclusion,Ac2-26 treatment has improved hemodynamics and alleviated mitochondrial damage,leading to the recovery of cardiac function in AHF rats.The mechanism may be related to macrophage polarization change from M1 to M2.
万方数据
维普
