TREM2通过激活Th17细胞调节神经免疫炎症并保护局灶性脑缺血再灌注损伤  

TREM2 regulates neuroimmune inflammation and protects focal cerebral ischemia-reperfusion injury by activating Th17 cells

作　　者：陈海云 颜博[1] 何超明[1] 张磊 CHEN Haiyun;YAN Bo;HE Chaoming;ZHANG Lei(Department of Neurology,Sanya Central Hospital,the Third People's Hospital of Hainan Province,Sanya 572000,China)

机构地区：[1]三亚中心医院,海南省第三人民医院神经内科,三亚572000 [2]海南医学院基础医学与生命科学学院病理学教研室,海口571199

出　　处：《中国免疫学杂志》2023年第9期1822-1828,共7页Chinese Journal of Immunology

基　　金：海南省卫生健康行业科研项目(20A200137)。

摘　　要：目的:探讨髓细胞触发受体2(TREM2)调节局灶性脑缺血再灌注损伤和神经免疫炎症的作用和机制。方法:对小鼠的大脑行中动脉闭塞术(MCAO)以建立局灶性缺血再灌注损伤模型,分为假手术组(sham组)和MCAO组(n=6)。小干扰RNA(siRNA)构建TREM2的沉默质粒(TREM2 siRNA组),构建TREM2过表达质粒(pcDNA-TREM2组),以及各自的阴性对照(CON siRNA)组和pcDNA组分别感染MCAO小鼠。采用IL-17抑制剂苏金单抗(SEC)联合pcDNA-TREM2处理MCAO组(MCAO+pcDNA-TREM2+SEC组)。qPCR和Western blot检测TNF-α、IL-1β、IL-17和TREM2表达;免疫荧光法检测脑部TREM2定位;TTC染色评价脑损伤程度;流式细胞术检测Th17细胞比例。结果:TREM2表达于小胶质细胞,且MCAO组TREM2表达均增加(P<0.05)。沉默TREM2诱导神经元细胞凋亡(F=206.971,P=0.001)、梗死体积和神经功能障碍评分升高(均P<0.05),TNF-α和IL-1β的mRNA水平升高,IL-10降低(均P<0.05)。过表达TREM2导致TNF-α、IL-1β表达降低,而IL-10和IL-17表达及Th17阳性细胞比例升高(均P<0.05)。与MCAO+pcDNA-TREM2组比较,MCAO+pcDNA-TREM2+SEC组的Th17细胞比例降低、神经元百分比降低,脑损伤程度增加,TNF-α、IL-1β表达升高,IL-10和IL-17表达降低(均P<0.05)。结论:过表达TREM2可通过激活Th17细胞并抑制神经炎症从而保护局灶性脑缺血再灌注损伤。Objective:To explore the role and mechanism of myeloid trigger receptor 2(TREM2)in regulating focal cerebral ischemia-reperfusion injury and neuroimmune inflammation.Methods:Middle cerebral artery occlusion(MCAO)surgery was performed to establish a mouse model of focal ischemia-reperfusion injury,which was divided into sham operation group(sham group)and MCAO group(n=6).Small interfering RNA(siRNA)was used to construct TREM2 silencing plasmid(TREM2 siRNA group),and to construct TREM2 overexpression plasmid(pcDNA-TREM2 group),and their respective negative control(CON siRNA)group and pcDNA group were respectively infected with MCAO mice.The MCAO group was treated with IL-17 inhibitor secukinumab(SEC)combined with pcDNA-TREM2(MCAO+pcDNA-TREM2+SEC group).qPCR and Western blot were used to detect the expressions of TNF-α,IL-1β,IL-17 and TREM2;immunofluorescence method was used to detect the location of TREM2 in brain;TTC staining was used to evaluate the degree of brain damage;flow cytometry was used to detect the proportion of Th17 cells.Results:TREM2 was expressed in microglia,and the expression of TREM2 in the MCAO group increased(P<0.05).Silencing TREM2 induced neuronal apoptosis(F=206.971,P=0.001),infarct volume and neurological dysfunction score increased(all P<0.05),TNF-αand IL-1βmRNA levels increased,and IL-10 decreased(both P<0.05).Overexpression of TREM2 led to a decrease in the expressions of TNF-αand IL-1β,while expressions of IL-10 and IL-17 and the proportion of Th17 positive cells increased(all P<0.05).Compared with the MCAO+pcDNA-TREM2 group,the proportion of Th17 cells in the MCAO+pcDNA-TREM2+SEC group decreased,the percentage of neurons decreased,the degree of brain damage increased,the expressions of TNF-α,IL-1βwere increased,and IL-10,IL-17 were decreased(all P<0.05).Conclusion:Overexpression of TREM2 can protect against focal cerebral ischemia-reperfusion injury by activating Th17 cells and inhibiting neuroinflammation.

关 键 词：髓细胞触发受体2 TH17细胞 神经免疫炎症 局灶性脑缺血再灌注损伤 

分 类 号：R743.3[医药卫生—神经病学与精神病学]