急性脑梗死激活机体内NLRC4介导的炎症级联反应

Acute cerebral infarction activates NLRC4-mediated inflammatory cascades

目的探讨炎症小体NLR家族含CARD结构蛋白4(NLR family CARD domain-containing protein 4,NLRC4)的表达与急性脑梗死(acute cerebral infarction,ACI)之间的关系。方法选取2019年5月—2020年8月就诊于徐州医科大学附属淮海医院神经内科的39例ACI患者作为研究组,另选取同期于我院进行健康体检的40例患者作为对照组。酶联免疫吸附法检测患者及大鼠外周血中NLRC4、白介素-1β(IL-1β)及白介素-18(IL-18)的表达水平。通过阻断大鼠大脑中动脉血流24 h构建大鼠ACI动物模型,使用蛋白免疫印迹实验、组织切片免疫荧光染色实验评估缺血损伤对大鼠脑组织中NLRC4表达的影响。结果与对照组相比,研究组患者在年龄、体质量指数、性别构成、糖尿病以及吸烟情况方面差异无统计学意义(P>0.05),而高血压患者比例增高(P<0.05);血生化检查项目中,研究组患者外周血中C-反应蛋白水平较对照组显著升高(P<0.05),而高密度脂蛋白水平低于对照组(P<0.05);研究组患者外周血中NLRC4、IL-1β的表达较对照组显著升高(P<0.05)。蛋白免疫印迹实验结果显示NLRC4在缺血损伤大鼠脑组织中表达上调,差异有统计学意义(P<0.05);组织切片免疫荧光染色结果显示NLRC4在缺血损伤的神经元细胞中表达升高;ELISA结果显示NLRC4、IL-1β及IL-18在ACI大鼠外周血中的表达水平较对照组显著升高(P<0.05)。结论NLRC4及其介导的炎症小体信号在ACI脑组织中显著上调,具有作为新型ACI治疗靶点的潜力。

Objective To discuss the expression of NLR family CARD domain-containing protein 4(NLRC4)and its relationship with acute cerebral infarction(ACI).Methods A total of 39 ACI patients who were admitted in the Affiliated Huaihai Hospital of Xuzhou Medical University from May 2019 to August 2020 were selected and set as a study group.Meanwhile,40 patients who underwent physical examination in our hospital were selected as a control group.The expression of NLRC4,interleukin(IL)-1βand IL-18 in the peripheral blood of patients and rats were detected by ELISA.Then,an ACI rat model was established by blocking the blood flow of middle cerebral artery for 24 h.Immunofluorescence staining and Western blot were used to detect the expression of the NLRC4 in ischemic and sham operated brain tissue.Results Compared with the control group,the study group showed no statistical difference in age,sex,body mass index and diabetic and smoking history(P>0.05),with an increased proportion of hypertension(P<0.05).For blood biochemical tests,compared with the control group,the level of C-reactive protein in ACI patients significantly increased,but high-density lipoprotein levels were reduced(P<0.05).ELISA results showed that the levels of NLRC4 and IL-1βin the peripheral blood of ACI patients were significantly up-regulated(P<0.05).Immunofluorescence staining confirmed that the expression of NLRC4 in ischemic-injured neurons increased.According to ELISA results,the levels of NLRC4,IL-1βand IL-18 in the peripheral blood of ACI rats were remarkably higher than those in the control groups(P<0.05).Conclusions NLRC4 and its medicated inflammasome signals are remarkably up-regulated in ACI tissues,which suggest its potential role as a therapeutic target for stroke.