【摘要】 目的 研究抑制核苷酸结合寡聚化结构域样受体蛋白3(NLRP3)炎性小体对心脏缺血/再灌注（I/R）损伤大鼠心脏重构的作用及机制。方法 30只雄性SD大鼠随机分为3组（每组10只）：Control组、I/R+MCC950组和I/R+Vehicle组，后两组建立心脏I/R损伤模型，分别腹腔注射MCC950(10 mg/kg)或等量生理盐水，每天一次持续7 d,Control组只开胸不建模，腹腔注射生理盐水方案同前。记录造模3 d和7 d的心脏超声指标，心电图参数和心率变异性参数。以天狼猩红染色检测心脏纤维化，TUNEL染色检测心肌细胞凋亡，免疫荧光染色检测心脏交感神经重构相关分子的表达，以及室旁核小胶质细胞激活和NLRP3通路相关分子的表达。以蛋白免疫印迹检测心脏纤维化、凋亡和NLRP3信号通路相关分子的蛋白表达。结果 与Control组相比，I/R+Vehicle组左心室收缩末期内径（LVIDs）和左心室舒张末期内径（LVIDd）增加（P均<0.05），左心室射血分数（LVEF）和左心室缩短分数（LVFS）降低（P均<0.05）；心电图QRS波时限、QT间期和校正的QT间期（QTc）延长（P均<0.05），低频功率（LF）、低频功率和高频功率比值（LF/HF）增加（P均<0.05）；心脏纤维化面积增加（P<0.05）,TUNEL染色阳性细胞数量增多（P<0.05），心室抗凋亡相关斑点样蛋白（ASC）和白介素-1β(IL-1β)表达增加（P均<0.05），心室酪氨酸羟化酶（TH）、生长相关蛋白-43(GAP43)和神经肽Y(NPY)的表达增加（P均<0.05），室旁核小胶质细胞ASC、半胱氨酸天冬氨酸蛋白水解酶-1(Caspase-1)和IL-1β的表达增加（P均<0.05）。MCC950干预显著改善以上变化，与I/R+Vehicle组相比，I/R+MCC950组LVIDs和LVIDd减小（P均<0.05）,LVEF和LVFS增加（P均<0.05）；心电图QRS波时限、QT间期和QTc明显缩短，LF和LF/HF降低（P均<0.05）；心脏纤维化面积明显减少、TUNEL染色阳性细胞数量减少、心室ASC和IL-1β、TH、GAP43和NPY的表达减少（P均<0.05），室旁核小胶质细胞ASC、Caspase-1和IL-1β的表达降低（P均<0.05）。结论 抑制NLRP3炎性小体可抑制室旁核小胶质细胞和神经元的激活，降低心脏交感神经活性，减轻心脏I/R损伤后的心脏结构重构、电重构和交感神经重构。更多还原

【Abstract】 Objective To explore the effect and mechanism of inhibiting nod-like receptor protein 3(NLRP3) inflammasome on cardiac remodeling in cardiac ischemia/reperfusion(I/R) injury rats. Methods Thirty male Sprague-Dawley rats were randomly divided into three groups: Control group, I/R+Vehicle group, and I/R+MCC950 group, with 10 rats in each group. After establishing a cardiac I/R injury model, MCC950(10 mg/kg) or an equal amount of saline was injected intraperitoneally according to the group every day for 7 days. The Control group only opened the chest without intervention, and intraperitoneal injected with saline as the same. Cardiac function was evaluated via cardiac ultrasound. Electrocardiogram parameters and heart rate variability were analyzed. The cardiac fibrosis was evaluated via picrosirius red staining. The cardiomyocyte apoptosis was evaluated via TUNEL staining. The expression of molecules associated with cardiac sympathetic activation and remodeling, and the activation of microglia and NLRP3 pathway-related molecules were evaluated via immunofluorescence. The protein expression of molecules associated with cardiac fibrosis, apoptosis and NLRP3 signaling pathway was evaluated via Western Blotting. Results Compared with the Control group, the I/R+Vehicle group showed increased left ventricular internal diameter at end-systole(LVIDs) and left ventricular internal diameter at end-diastole(LVIDd)(all P<0.05), decreased left ventricular ejection fraction(LVEF) and left ventricular factional shortening(LVFS)(all P<0.05), The QRS duration, QT interval, and corrected QT interval(QTc) were prolonged, the low frequency(LF) and the ratio of low frequency and high frequency(LF/HF) increased(all P<0.05). The cardiac fibrosis was more severe(P<0.05). The number of TUNEL~+ cells increased(P<0.05). The expression of apoptosis-associated speck-like protein containing a CARD(ASC) and interleukin-1 beta(IL-1β) increased in the ventricle(all P<0.05). The expression of tyrosine hydroxylase(TH), growth-associated protein-43(GAP43), and neuropeptide Y(NPY) increased in the ventricle, and the expression of ASC、 Caspase-1 and IL-1β increased in the microglia of paraventricular nucleus(all P<0.05). MCC950 treatment significantly improved the changes above. Compared with the I/R+Vehicle group, the I/R+MCC950 group showed decreased LVIDs and LVIDd(all P<0.05), increased LVEF and LVFS(all P<0.05), The QRS duration, QT interval, and QTc were significantly shortened, and the LF and LF/HF ratio decreased(all P<0.05). The cardiac fibrosis was less severe(P<0.05). The number of TUNEL~+ cells decreased. The expression of ASC and IL-1β decreased in the ventricle(all P<0.05). The expression of TH, GAP43, and NPY decreased in the ventricle, and the expression of ASC, Caspase-1, and IL-1β decreased in the microglia of paraventricular nucleus(all P<0.05). Conclusion Inhibiting the NLRP3 inflammasome reduced cardiac sympathetic activity and inhibited cardiac electrical remodeling and sympathetic remodeling after cardiac I/R injury by inhibiting the activation of microglia and neurons in the paraventricular nucleus of hypothalamus.更多还原