MG53蛋白对创伤性脑损伤小鼠小胶质细胞极化和神经炎症的调控作用

Regulation of MG53 protein on microglial polarization and neuroinflammation in traumatic brain injury mice

目的:研究MG53蛋白对创伤性脑损伤(TBI)小鼠小胶质细胞极化和神经炎症的调控作用。方法:改良式自由落体法建立中度TBI小鼠模型,随机分为TBI组和MG53组,每组3只;免疫荧光检测脑组织中CD3、胶质纤维酸性蛋白(GFAP)、CD86、CD206和巢蛋白(Nestin)的表达;ELISA法检测血清IL-1β、TNF-α、IL-4和IL-10水平;qRT-PCR检测脑组织中CD86、诱导型一氧化氮合酶(iNOS)、CD206、精氨酸酶1(ARG1)、Nestin、双皮质醇(DCX)、脑源性神经营养因子(BDNF)、神经生长因子(NGF)mRNA的表达;Western blot检测脑组织中核苷酸结合寡聚化结构域样受体蛋白3(NLRP3)、Cleaved-Caspase-1和IL-1β蛋白的表达。结果:与TBI组相比,MG53组小鼠脑组织中CD3、GFAP的表达减少,血清中促炎因子IL-1β和TNF-α水平降低,而抗炎因子IL-4和IL-10水平升高(P<0.05)。此外,与TBI组相比,MG53组小鼠脑组织中CD86和iNOS mRNA表达降低,而CD206、Nestin、DCX、BDNF和NGF mRNA表达增加(P<0.05)。与TBI组相比,MG53组小鼠NLRP3、Cleaved-Caspase-1和IL-1β蛋白表达降低(P<0.05)。结论:MG53蛋白可能通过抑制NLRP3/Caspase-1/IL-1β信号通路,抑制小胶质细胞极化和神经炎症,进而对TBI小鼠发挥神经保护作用。

Aim:To explore the regulation of MG53 protein on microglial polarization and neuroinflammation in traumatic brain injury(TBI)mice.Methods:The mouse moderate TBI model was established by modified free fall method and randomly divided into TBI group and MG53 group(n=3).Immunofluorescence was used to detect the expressions of CD3,glial fibrillary acidic protein(GFAP),CD86,CD206 and Nestin.ELISA was utilized to detect the expressions of IL-1β,TNF-α,IL-4 and IL-10 in serum.qRT-PCR was used to examine the mRNA expressions of CD86,inducible nitric oxidet synthase(iNOS),CD206,arginase-1(ARG1),Nestin,doublecortion(DCX),brain-derived neurotrophic factor(BDNF)and nerve growth factor(NGF)in brain tissue.Western blot was performed to analyze the protein expressions of NOD-like receptor protein 3(NLRP3),Cleaved-Caspase-1 and IL-1βin brain tissue.Results:Compared with TBI group,the expressions of CD3 and GFAP in the brain tissue of MG53 group decreased,and the levels of IL-1βand TNF-αin the serum decreased,while the levels of IL-4 and IL-10 increased(P<0.05).In addition,compared with TBI group,MG53 group exhibited lower expressions of CD86 and iNOS mRNA,and higher expressions of CD206,Nestin,DCX,BDNF and NGF mRNA in the brain tissue(P<0.05).Furthermore,compared with TBI group,the protein expressions of NLRP3,Cleaved-Caspase-1,and IL-1βdecreased in MG53 group(P<0.05).Conclusion:MG53 protein may exert neuroprotective effects on TBI mice by inhibiting the NLRP3/Caspase-1/IL-1βsignaling pathway and thus inhibiting the microglial polarization and neuroinflammation.