摘要
目的探讨姜黄素对早期脓毒症大鼠心肌细胞中核苷酸结合寡聚化结构域样受体蛋白(NLRP3)炎性小体的作用及其机制。方法24只雄性SD大鼠随机(随机数字法)分为3组:假手术组(Sham组,n=8)、脓毒症组(Sepsis组,n=8)、姜黄素干预组(Cur组,n=8)。采用盲肠结扎穿孔术(CLP)制备大鼠脓毒症模型,造模后腹腔注射姜黄素100 mg/kg,24 h后重复给药,Sepsis组注射生理盐水。于6、24、48 h通过ELISA法检测大鼠血浆中心肌损伤特异性肌钙蛋白T(cTnT)水平;取48 h大鼠心肌组织经苏木精-伊红(HE)染色观察心肌病理损伤情况;通过TUNEL法检测心肌细胞凋亡情况;Western-blot法检测Cleaved caspase-1、NLRP3、IL-1β蛋白的表达情况;透射电镜下观察心肌细胞内部超微结构改变。结果Cur组6、24、48 h大鼠血浆cTnT水平明显低于Sepsis组,差异有统计学意义(P<0.05);HE染色可见Sepsis组心肌炎性细胞浸润,细胞水肿、坏死,而Cur组仅见部分细胞水肿和坏死现象;TUNEL染色可见Cur组心肌细胞凋亡(28.4±2.3)%低于Sepsis组(43.6±3.8)%,P<0.05;Western-blot检测Cur组Cleaved caspase-1、NLRP3、IL-1β蛋白表达低于Sepsis组,高于Sham组,P<0.05。透射电镜下Sham组细胞核膜完整、染色质分布均匀;Sepsis组细胞核染色质边集、体积固缩,线粒体嵴断裂、空化现象,肌小节部分断裂;Cur组细胞核染色质部分边集,线粒体轻度水肿扩张,形态基本完整。结论姜黄素抑制脓毒症大鼠NLRP3介导的急性心肌损伤,其机制可能与下调Cleaved caspase-1、IL-1β蛋白表达引起的细胞焦亡有关。
Objective To investigate the effect of curcumin on the nucleotide-binding oligomerization domain-like receptor protein(NLRP3)inflammasome in cardiomyocytes of rats with early sepsis and its mechanism.Methods Twenty-four male SD rats were randomly divided into three groups:the sham-operated group(sham group,n=8),the sepsis group(n=8),and the curcumin intervention group(Cur group,n=8).A rat model of sepsis was prepared by cecal ligation and perforation(CLP).After modeling,100 mg/kg of curcumin was intraperitoneally injected and repeated 24 h later.Rats in the sepsis group were injected with normal saline.The levels of myocardial injury-specific troponin T(cTnT)in rat plasma were detected by ELISA at 6,24,and 48 h.Hematoxylin-eosin(HE)staining was used to observe the pathological injury of the myocardium in the myocardial tissue of rat at 48 h.The apoptosis of cardiomyocytes was detected by TUNEL assay.The expression levels of Cleaved caspase-1,NLRP3 and IL-1βprotein were detected by Western blot,and the ultrastructural changes of the cardiomyocytes were observed under a transmission electron microscope.Results The levels of cTnT in rat plasma at 6,24,and 48 h in the Cur group were significantly lower than those in the sepsis group(P<0.05).HE staining showed infiltration,cell edema and necrosis of myocardial inflammatory cells in the sepsis group,while only partial cell edema and necrosis were observed in the Cur group.TUNEL assay showed that the apoptosis of cardiomyocytes in the Cur group was significantly lower than that in the sepsis group[(28.4±2.3)%vs.(43.6±3.8)%,P<0.05].The expression levels of Cleaved caspase-1,NLRP3 and IL-1βin the Cur group were lower than those in the sepsis group and higher than those in the sham-operated group(P<0.05).Under transmission electron microscopy,the nuclei in the sham-operated group had intact membranes and uniform chromatin distribution;in the sepsis group chromatin margination,pyknosis,mitochondrial cristae breakage,cavitation,and partial breakage of sarcomere were observed;while in the Cur group partial chromatin margination,slightly edema and dilation of mitochondria,with basically complete morphology were observed.Conclusions Curcumin inhibits NLRP3-mediated acute myocardial injury in septic rats,and its mechanism may be related to pyroptosis induced by the down-regulation of the expression of Cleaved caspase-1 and IL-1βprotein.
作者
李青松
陈俊杰
李永宁
王立峰
Li Qingsong;Chen Junjie;Li Yongning;Wang Lifeng(Department of Cardiology,The First Affiliated Hospital of Dalian Medical University,Dalian 116001,China;Department of Emergency Medicine,The First Affiliated Hospital of Dalian Medical University,Dalian 116001,China)
出处
《中华急诊医学杂志》
CAS
CSCD
北大核心
2022年第2期173-178,共6页
Chinese Journal of Emergency Medicine
基金
辽宁省自然科学基金项目(2019-ZD-0644)。
