槲皮素促进小鼠脊髓损伤后巨噬细胞表型转变及功能恢复

摘要

目的 探讨槲皮素对小鼠脊髓损伤后损伤局部炎性反应的影响.方法 通过钳夹法构建C57BL/6小鼠T10节段脊髓损伤模型,随机分为脊髓损伤组(SCI组)和脊髓损伤+槲皮素治疗组(Quercetin组),术后1~14 d于腹腔注射槲皮素(1次/天),SCI组腹腔注射0.9%NaCl溶液.术后3、7和14 d,用激光共聚焦荧光显微镜观察巨噬细胞表型M1(iNOS)和M2(Arg1)并计数;用real-time PCR检测局部组织炎性因子mRNA的表达.用BMS量表对小鼠神经功能损伤修复情况进行评价.结果 与 SCI 组相比,Quercetin 组 M1(iNOS/CD11b)表型细胞的比例下降(P<0.05),M2(Arg1/CD11b)表型细胞的比例上调(P<0.05);同时,Quercetin组促炎因子(TNF-α、NOS2)的表达下降(P<0.05),抑炎因子(TGF-β、IL-10)的表达上调(P<0.05).且Quercetin组在损伤后7和14后BMS评分均显著高于SCI组(P<0.05).结论 槲皮素可以促进小鼠脊髓损伤后巨噬细胞表型由M1向M2表型转变,抑制炎性因子的表达,对炎性反应的调控是其发挥神经保护作用的可能机制之一.%Objective To investigate the effects of quercetin with a special focus on their effect on macrophage po-larization after SCI.Methods Adult C57 mice underwent T10 spinal cord clip compression injury,then were ran-domly divided into SCI group and quercetin group.1-14 d after SCI received quercetin by intraperitoneal injection(once a day)in quercetin group,and received same normal saline in the SCI group.3,7 and 14 d after SCI, the lesion section of SCI group and Quercetin group stained by immunofluorescent:M1 macrophages pheno-type cell labeled with iNOS, and M2 macrophages phenotype cell labeled with Arg1.The mRNA expression of inflammatory factors in lesion site was detected by RT-PCR.The motor function was evaluated by Basso mouse scale(BMS)after SCI.Results Compare with SCI group,the expression of arginase-1(associated with M2 mac-rophage phenotype)significantly increased in quercetin group(P<0.05).The expression of inducible nitric oxide synthase-iNOS(M1 phenotype marker)was down-regulated as demonstrated using immunohisto-chemistry(P<0.05).Furthermore,the production of NOS2 and tumor necrosis factor alpha was significantly reduced whereas the level of interleukin 10 and TGF-β were elevated in quercetin group(P<0.05).The time course of functional recov-ery revealed a gradual recovery in the subacute phase in quercetin group, little improvement was observed in SCI group(P<0.05).Conclusions It is found that quercetin may promote the shift of M1 to M2 phenotype and amelio-rate the inflammatory microenvironment.Furthermore,the roles of quercetin in immunity modulation may enhance neuroprotective effects and partially contribute to the locomotor functional recovery after SCI.