二甲双胍对脑出血模型小鼠血肿周围脑组织炎症反应的影响

Effects of metformin on inflammation of brain tissue around hematoma in intracerebral hemorrhage mouse model

目的探讨二甲双胍干预小鼠脑出血(ICH)后血肿周围脑组织炎症反应的作用机制。方法 60只成年雄性C57/BL6小鼠,简单随机抽样分成3组:假手术组、模型组和二甲双胍组,每组20只。其中模型组和二甲双胍组经微量注射器向脑实质内注射Ⅵ型胶原酶(1μL,0.075 U)制作ICH模型,假手术组注射1μL生理盐水。二甲双胍组小鼠在造模后6 h予以二甲双胍(100 mg/kg)连续灌胃7 d,模型组予以等量的生理盐水灌胃。于治疗后第3、7天应用免疫组化染色方法检测血肿周围脑组织髓过氧化物酶(MPO)、离子钙接头蛋白(Iba-1)表达情况。Westernblot法检测出血后第3天血肿周围的白细胞介素(IL)-1β、肿瘤坏死因子(TNF)-α的表达。结果分组处理后第3、7天,与模型组相比,二甲双胍组小鼠血肿周围脑组织MPO和Iba-1阳性细胞数量明显减少(P<0.05)。处理后第3天,二甲双胍组IL-1β、TNF-α的表达水平较模型组降低(P<0.05)。结论二甲双胍能够减轻ICH后小鼠脑血肿周围炎症因子和炎症细胞的浸润以及小胶质细胞的过度激活。

Objective To evaluate the effect of metformin on inflammatory response around the hematoma afterintracerebral hemorrhage(ICH)in mice.Methods A total of60male C57/BL6mice were randomly divided into3groups:Sham group,model group and metformin group,20mice for each group.The model group and metformin group were injectedbacterial collagenase(1μL,0.075U)into the striatum.The Sham group was injected1μL saline into the striatum.Themetformin group was treated with metformin(gavage administration,100mg/kg)6h after ICH and for7consecutive days.The model group was given equal saline orally.The expression levels of myeloperoxidase(MPO)and the calcium bindingprotein1(Iba-1)around the hematoma(microglia)were detected by immunohistochemical staining at3days and7days afterICH.Interleukin-1βand TNF-αwere detected by Western blot assay at3days after ICH.Results Results ofimmunohistochemical staining showed that the positive expression levels of MPO and Iba-1were significantly lower thanthose in model group3days and7days after treatment(P<0.05).The expression levels of IL-1βand TNF-αweresignificantly lower in metformin group than those in model group3days after treatment(P<0.05).Conclusion Metformincan reduce the infiltration of inflammatory cytokines and inflammatory cells and the excessive activation of microglia afterICH in mice.