巨噬细胞移动抑制因子抑制剂ISO-1对重症肺炎大鼠炎症反应的影响

Effects of macrophage migration inhibitory factor inhibitor ISO-1 on inflammatory response in rats with severe pneumonia

目的分析巨噬细胞移动抑制因子(MIF)抑制剂ISO-1对重症肺炎大鼠炎症反应影响。方法选取SPF级Wistar雄性大鼠45只,随机数字表法将大鼠分成3组,正常组、模型组、ISO-1组,每组各15只。除正常组外,其他大鼠制备重症肺炎模型,成功造模后正常组和模型组大鼠经尾部注射100 mL生理盐水,ISO-1组注射溶解ISO-1(7 mg/kg)的5%二甲基亚砜溶液(2 mL/kg)。分别在实验结束后观察各组大鼠肺组织病理情况,并行支气管肺泡灌洗液(BALF)细胞计数,检测肺组织内髓过氧化物酶(MPO)活性,检测各组大鼠BALF内炎症标志物CD14、降钙素原、C反应蛋白(CRP)水平,炎性因子白细胞介素(IL)-10、IL-6、IL-1及肿瘤坏死因子α(TNF-α)水平,Western blot检测干扰素调节因子(IRF3)、髓样分化因子88(MyD88)、核因子(NF)-κB p65、IκB-α蛋白表达。结果正常组大鼠肺部结构正常,无组织病理改变;模型组大鼠肺组织表征为广泛病理学异常与形态学受损,表现肺泡水肿、萎缩,肺泡壁厚度增大,嗜中性粒细胞浸润至肺泡腔内;ISO-1组大鼠相对于模型组大鼠其组织病理学受损显著减轻。与正常组相比,模型组大鼠动脉血二氧化碳分压(PaCO_(2))、BALF内细胞数量、MPO活性,TNF-α、IL-1、IL-6、IL-10、MyD88、IRF3蛋白表达水平均升高,CO_(2)含量、动脉血氧分压(PaO_(2))及氧饱和度(SO_(2))均降低;与模型组相比,ISO-1组PaCO_(2)、BALF内细胞数量、MPO活性,TNF-α、IL-1、IL-6、IL-10、MyD88、IRF3蛋白表达水平均降低,CO_(2)含量、PaO_(2)及SO_(2)均升高(P<0.05)。结论MIF抑制剂ISO-1可显著降低重症肺炎大鼠机体内炎性因子水平,改善大鼠肺组织病理情况,其作用机制可能与降低MyD88、NF-κB p65、IκB-α蛋白表达有关。

Objective To analyze the effect of macrophage migration inhibitory factor inhibitor ISO-1 on inflammatory response in rats with severe pneumonia.Methods SPF Wistar male rats(n=45)were assigned to one of the 3 groups(normal,model,or ISO-1)by random number table method,15 rats in each group.The rats in model group and ISO-1 group were used to prepare severe pneumonia models.After the model of severe pneumonia was successfully established,the rats in the normal group and the model group were injected with 100μL of normal saline through the tail,and the rats in ISO-1 group were injected with ISO-1(7 mg/kg)5%dissolved in dimethyl sulfoxide solution(2 mL/kg).The pathological changes of the lung tissues were observed for the rats in each group.The cells in bronchoalveolar lavage fluid(BALF)were counted.The activity of myeloperoxidase(MPO)in the lung tissue was detected.The inflammatory markers in the BALF were detected,including procalcitonin,C-reactive protein(CRP),and inflammatory factors,including interleukin(IL)-10,IL-6,IL-1,and tumor necrosis factor-α(TNF-α).Western blot was used to determine the expression of interferon regulatory factor(IRF3),myeloid differentiation factor 88(MyD88),NF-κB p65,IκB-αprotein in lung tissues.Results The lung structure was normal without histopathological changes for the rats in the normal group.The lung tissues of the rats in the model group were characterized by extensive pathological abnormalities and morphological damage,including alveolar edema,atrophy,increased alveolar wall thickness,and neutrophils.The cells infiltrated into the alveolar space.The rats in ISO-1 group showed significantly less histopathological damage than the rats in the model group.The rats in the model group showed significantly higher PaCO_(2),number of cells in BALF,MPO activity,TNF-α,IL-1,IL-6,and IL-10 levels in BALF,and expression of MyD88 and IRF3 proteins,but significantly lower CO_(2),PaO_(2)and SO_(2)compared with the normal group.The rats in ISO-1 group demonstrated significantly lower PaCO_(2),number of cells in BALF,MPO activity,TNF-α,IL-1,IL-6,and IL-10 levels in BALF,and expression of MyD88 and IRF3 proteins,but significantly higher CO_(2),PaO_(2),and SO_(2)levels(P<0.05)compared with the model group.Conclusions MIF inhibitor ISO-1 can significantly reduce the levels of inflammatory factors in rats with severe pneumonia and improve the pathology of lung tissues in rats.The underlying mechanism of action may be related to reduced expression of MyD88,NF-κB p65 and IκB-αproteins.