SR9009在脓毒症心肌损伤中与NLRP3的关系

Relationship between SR9009 and NLRP3 in septic myocardial injury

目的:评价Rev-erbα激动剂SR9009在脂多糖(LPS)诱导的脓毒症心肌损伤小鼠中与NLRP3炎症小体的关系。方法:健康雄性C57BL/6小鼠32只,腹腔注射LPS(15 mg/kg)构建脓毒症心肌损伤模型,随机分为对照组(control组)、脓毒症组(LPS组)、SR9009组(SR组)、脓毒症+SR9009组(LPS+SR组),每组8只。在LPS+SR组中,在注射LPS前18 h腹腔注射50 mg/kg SR9009,SR组仅于同时间点按50 mg/kg腹腔注射SR9009而未注射LPS。超声心动图检测心脏功能,HE染色检测心脏组织损伤程度,ELISA法检测血清中肌钙蛋白(cTnI)、肌酸激酶同工酶(CK-MB)、乳酸脱氢酶(LDH)的含量。Western Blot法检测NLRP3、IL-1β和IL-18的蛋白相对表达量。结果:与control组比较,SR组无明显变化,而LPS组左室壁相对厚度和左心室射血分数均显著降低,而左室收缩末容积显著升高,血清心肌酶cTnI、CK-MB和LDH水平升高,心肌组织NLRP3、IL-1β和IL-18表达上调(P<0.05),心肌组织病理损伤加重;与LPS组相比,LPS+SR组左室壁相对厚度和左心室射血分数均显著升高,左室收缩末容积显著降低,血清中cTnI、CK-MB和LDH的含量显著下调;炎症小体NLRP3及促炎细胞因子IL-1β、IL-18的表达量下调(P<0.05),心肌组织病理损伤减轻。结论:SR9009通过抑制炎症小体NLRP3及促炎细胞因子IL-1β和IL18而发挥对脓毒症心肌损伤小鼠的保护作用。

Objective:To evaluate the relationship between Rev-erbαagonist SR9009 and NLRP3 inflammasome in lipopolysaccharide(LPS)-induced septic myocardial injury mice.Methods:A total of thirty-two healthy male C57BL/6 mice were intraperitoneally injected with LPS(15 mg/kg)to establish the myocardial injury model of sepsis.They were randomly divided into the control group(control group),sepsis group(LPS group),SR9009 group(SR group),and sepsis+SR9009 group(LPS+SR group),with eight rats in each group.In the LPS+SR group,SR9009 was intraperitoneally administered at 50 mg/kg 18 hours before LPS injection,and the mice in the SR9009 group were intraperitoneally injected with SR9009 at 50 mg/kg at the same time without LPS injection.Echocardiography was used to detect cardiac function,and HE staining was used to detect the degree of cardiac tissue damage.The contents of troponin(cTnI),creatine kinase isoenzyme(CK-MB),and lactate dehydrogenase(LDH)in serum were detected by ELISA.Western Blot was used to detect the relative protein expressions of NLRP3,IL-1β,and IL-18.Results:Compared with those in the control group,no significant changes were found in the SR group,while in the LPS group,the left ventricular wall thickness and left ventricular ejection fraction were significantly decreased,left ventricular end-systolic volume was significantly increased,the serum levels of myocardial enzymes cTnI,CK-MB,and LDH were also significantly increased,the expression of NLRP3,IL-1β,and IL-18 in myocardial tissue was up-regulated(P<0.05),and significant pathological changes of myocardial tissue were found.Compared with the changes in the LPS group,the LPS+SR group showed significantly increased left ventricular wall thickness and left ventricular ejection fraction,decreased left ventricular end-systolic volume,and decreased serum levels of cTnI,CK-MB,and LDH.The expression of inflammasome NLRP3 and proinflammatory cytokines IL-1βand IL-18 was also down-regulated(P<0.05),and pathological damage of myocardial tissue was alleviated after SR9009 treatment.Conclusion:SR9009 plays a protective role in sepsis-induced myocardial injury in mice by inhibiting NLRP3,IL-1β,and IL-18.