背景:心肌梗死(MI)引发强烈的炎症反应,与心肌纤维化和心脏重塑有关。白细胞介素(IL)-1β和IL-18是该反应的关键参与者,并受NLRP3炎症体控制。冬凌草甲素是一种新报道的NLRP3抑制剂,具有很强的抗炎活性。我们假设共价NLRP3抑制剂冬凌草甲素可以减少IL-1β和IL-18的表达并改善小鼠心肌梗死后的心肌纤维化。改善不良的心脏重塑,保持心脏功能。
方法:雄性C57BL/6小鼠进行左冠状动脉结扎以诱导MI,然后用冬凌草甲素(1、3或6mg/kg)治疗,MCC950(10mg/kg),CY-09(5mg/kg)或生理盐水,每周三次,共两周。心肌梗死四周后,评估了心功能和心肌纤维化。此外,用westernblot分析心肌炎症因子和纤维化标志物的表达,免疫荧光,酶联免疫吸附测定,和定量实时聚合酶链反应。
结果:冬凌草甲素治疗保留了左心室射血分数和缩短率,并显着限制了治疗小鼠的心肌梗塞面积。1mg/kg组心肌纤维化降低(15.98±1.64)%,3mg/kg组(17.39±2.45)%,6mg/kg组(16.76±3.06)%,对照组(23.38±1.65)%。此外,与Oridonin的结果相似,MCC950和CY-09还保留了心脏功能并减少了心肌纤维化。与未治疗组相比,冬凌草甲素治疗组的NLRP3,IL-1β和IL-18的表达水平降低。此外,冬凌草甲素治疗组的心肌巨噬细胞和中性粒细胞流入减少。
结论:在小鼠MI模型中,共价NLRP3-炎性体抑制剂冬凌草甲素减少心肌纤维化并保留心脏功能,这表明冬凌草甲素对急性心肌梗死患者的潜在治疗作用。
BACKGROUND: Myocardial infarction (MI) triggers a strong inflammatory response that is associated with myocardial fibrosis and cardiac remodeling. Interleukin (IL)-1β and IL-18 are key players in this response and are controlled by NLRP3-inflammatory bodies. Oridonin is a newly reported NLRP3 inhibitor with strong anti-inflammatory activity. We hypothesized that the covalent NLRP3 inhibitor Oridonin could reduce IL-1β and IL-18 expression and ameliorate myocardial fibrosis after myocardial infarction in mice, improve poor heart remodeling, and preserve heart function.
METHODS: Male C57BL/6 mice were subjected to left coronary artery ligation to induce MI and then treated with Oridonin (1, 3, or 6 mg/kg), MCC950 (10 mg/kg), CY-09 (5 mg/kg) or saline three times a week for two weeks. Four weeks after MI, cardiac function and myocardial fibrosis were assessed. In addition, myocardial expressions of inflammatory factors and fibrotic markers were analyzed by western blot, immunofluorescence, enzyme-linked immunosorbent assay, and quantitative real-time polymerase chain reaction.
RESULTS: Oridonin treatment preserved left ventricular ejection fraction and fractional shortening, and markedly limited the myocardial infarct size in treated mice. The myocardial fibrosis was lower in the 1 mg/kg group (15.98 ± 1.64)%, 3 mg/kg group (17.39 ± 2.45)%, and 6 mg/kg group (16.76 ± 3.06)% compared to the control group (23.38 ± 1.65)%. Moreover, similar with the results of Oridonin, MCC950 and CY-09 also preserved cardiac function and reduced myocardial fibrosis. The expression levels of NLRP3, IL-1β and IL-18 were decreased in the Oridonin treatment group compared to non-treated group. In addition, myocardial macrophage and neutrophil influxes were attenuated in the Oridonin treated group.
CONCLUSIONS: The covalent NLRP3-inflammasome inhibitor Oridonin reduces myocardial fibrosis and preserves cardiac function in a mouse MI model, which indicates potential therapeutic effect of Oridonin on acute MI patients.