摘要
目的:探讨miR-145对创伤性脑损伤(TBI)后炎症反应和免疫调节的作用。方法:将雄性C57BL/6小鼠随机分为假手术组(Sham)、模型组(TBI)、TBI+NC agomir组、TBI+miR-145 agomir组。改良神经损伤严重程度评分(mNSS)用于评估创伤后神经功能;MWM测试评估TBI后小鼠的神经认知功能;流式细胞术检测各组小鼠脑组织中Tregs数量;ELISA检测各组小鼠海马中炎症细胞因子表达;免疫组化检测各组小鼠海马中活化的小胶质细胞/巨噬细胞Iba-1表达;RT-qPCR检测M1/M2小胶质细胞/巨噬细胞标志物基因iNOS、CD11b、CD206和Arg1表达;TUNEL染色和神经元细胞核免疫荧光标记(NeuN)的双重染色检测神经元凋亡。结果:与Sham组比较,TBI组小鼠海马组织中miR-145表达显著降低,神经功能损伤增加,脑组织中Tregs在CD4+T细胞群中百分比降低,海马组织中IL-1β、IL-6、TNF-α、IL-4、IL-10和TGF-β表达显著升高,活化的小胶质细胞/巨噬细胞Iba-1数量增多,iNOS、CD11b、CD206和Arg1表达水平显著升高,神经元凋亡升高,Notch1、p21和Hes1 mRNA和蛋白水平均显著升高(P<0.05);与TBI+NC agomir组比较,TBI+miR-145 agomir组小鼠海马中miR-145表达显著升高,神经功能损伤减轻,脑组织中Tregs在CD4+T细胞群中的百分比显著升高,海马中促炎因子IL-1β、IL-6、TNF-α表达显著降低,抗炎因子IL-4、IL-10和TGF-β表达显著升高,活化的小胶质细胞/巨噬细胞Iba-1数量显著减少,iNOS和CD11b表达降低,CD206和Arg1表达水平显著升高,神经元凋亡减少,Notch1、p21和Hes1 mRNA和蛋白水平均显著降低(均P<0.05)。结论:miR-145过表达通过提高Tregs水平,促进小胶质细胞M2极化,调节创伤后神经炎症反应及改善行为功能障碍,这一机制可能通过Notch信号通路介导。
Objective:To investigate the role of miR-145 in inflammatory response and immune regulation after traumatic brain injury(TBI).Methods:Male C57BL/6 mice were randomly divided into sham operation group(Sham),model group(TBI),TBI+NC agomir group and TBI+miR-145 agomir group.Modified Nerve Injury Severity Score(mNSS)was used to evaluate neurological function after trauma.MWM test was used toevaluates neurocognitive function of mice after TBI.Flow cytometry was used to detect the number of Tregs in tbrain tissue of each group of mice.ELISA was used to detect expressions of inflammatory cytokines in hippocampus of each group of mice.Immunohistochemistry was used to detect expression of activated microglia/macrophage Iba-1 in hippocampus of each group of mice.RT-qPCR was used to detect expressions of M1/M2 microglia/macrophage marker genes iNOS,CD11b,CD206 and Arg1.TUNEL staining and neuronal nuclear immunity double staining with fluorescent label(NeuN)were used to detect neuronal apoptosis.Results:Compared with Sham group,expression of miR-145 in hippocampus of mice in TBI group was significantly decreased,the neurological damage was increased,and percentage of Tregs in CD4^(+)T cell population in brain tissue was decreased.Expression levels of IL-1β,IL-6,TNF-α,IL-4,IL-10 and TGF-βin hippocampus were significantly increased,the number of activated microglia/macrophage IBA-1 was increased,expression levels of iNOS CD11b,CD206 and Arg1 were significantly increased,and the neuronal apoptosis was increased.Notch1,p21 and Hes1 mRNA and protein levels were significantly increased(all P<0.05).Compared with TBI+NC agomir group,expression of miR-145 in hippocampus of mice in TBI+miR-145 agomir group was significantly increased,and neurological damage was reduced.Percentage of Tregs in CD4^(+)T cell population in brain tissue was significantly increased,expressions of pro-inflammatory cytokines IL-1β,IL-6,and TNF-αwere decreased,while anti-inflammatory cytokines IL-4,IL-10 and TGF-βwere significantly increased in hippocampus.The number of activated microglia/macrophage IBA-1 was significantly decreased,expression levels of iNOS and CD11b were decreased,while expression levels of CD206 and Arg1 were significantly increased.mRNA and protein levels of Notch1,p21 and Hes1 were significantly reduced(all P<0.05).Conclusion:Overexpression of miR-145 promotes M2 polarization of microglia to regulate post-traumatic neuroinflammatory response and improve behavioral dysfunction by increasing Treg level,which may be mediated by Notch signaling pathway.
作者
胡德献
孙衍昶
冯基高
莫业和
HU Dexian;SUN Yanchang;FENG Jigao;MO Yehe(Department of Neurosurgery,Second Affiliated Hospital of Hainan Medical College,Haikou 570311,China)
出处
《中国免疫学杂志》
CAS
CSCD
2024年第3期497-502,共6页
Chinese Journal of Immunology
基金
海南省卫生健康行业科研项目(21A200277)。
