3,3'-二吲哚甲烷通过抑制肝巨噬细胞炎症因子表达改善酒精性肝病的机制

Mechanism on 3,3 ′-diindomethane improving alcoholic liver disease by inhibition of inflammatory factor expression in hepatic macrophages

目的 观察3,3’-二吲哚甲烷(DIM)对小鼠酒精性肝病的改善作用及对其肝巨噬细胞激活的抑制作用,并初步探讨其分子作用机制。方法 将6~8周龄雄性C57BL/6J小鼠随机分为4组:正常对照组、酒精组、DIM组和酒精+DIM组,观察肝脏的病理改变和巨噬细胞相关炎症因子的表达;分离腹腔巨噬细胞,按正常对照组、酒精组(100 mmol/L)、DIM(10μmol/L)组和DIM(10μmol/L)+酒精(100 mmol/L)组处理后,观察原代巨噬细胞炎症因子的表达,Western blot检测NLRP3通路蛋白的表达。结果 病理结果显示,酒精组肝脏脂肪变性和炎症因子表达上升,DIM能够改善肝脏损伤和炎症细胞浸润。DIM明显降低了DIM+酒精组细胞因子TGF-β、TNF-α、IL-1a和IL-1b的水平。体外实验发现,DIM明显降低了酒精诱导巨噬细胞表达TGF-β、TNF-α、IL-1a和IL-1b的mRNA水平。蛋白检测的结果发现DIM明显降低了酒精诱导的NLRP3、Cleaved Caspase-1和Cleaved IL-1的蛋白水平。结论 DIM改善了小鼠酒精性肝病,抑制了巨噬细胞炎症因子的表达,NLRP3通路的下调可能是DIM抑制炎症因子表达的机制之一。

Objective To observe the improvement effect of 3,3’-diindolylmethane(DIM) on alcoholic liver disease in mice and the inhibition effect on the activation of liver macrophages,and preliminarily explore its molecular mechanism.Methods Male C57 BL/6 J mice aged 6-8 weeks were randomly divided into 4 groups:normal control,alcohol,DIM(50 mg/kg) and alcohol +DIM(50 mg/kg),the pathological changes of the liver and the expression of macrophage-related inflammatory factors were observed after the experiment;The peritoneal macrophages were isolated and treated in normal control group,alcohol group(100 mmol/L),DIM group(10 μ mol/L) and DIM group(10 μmol/L)+alcohol group(100 mmol/L).The expression of inflammatory factors in primary macrophages was observed,and the expression of NLRP3 pathway protein was detected by Western blot.Results Pathological results showed that hepatic steatosis and inflammatory factor expression increased after alcohol exposure,and DIM was able to significantly improve hepatic steatosis and inflammatory cell infiltration.DIM significantly reduced the levels of the cytokines TGF-b,TNF-a,IL-1 a,and IL-1 b.In vitro experiments revealed that DIM significantly reduced the mRNA levels of alcohol-induced macrophages expressing TGF-b,TNF-a,and IL-1 a and IL-1 b.The results of the protein detection test found that DIM significantly reduced the protein levels of alcohol-induced NLRP3,Cleaved Caspase-1,and Cleaved IL-1 b.Conclusion DIM improved alcoholic liver disease in mice by inhibiting inflammatory factor release from macrophages,and downregulation of NLRP3 pathway may be one of the mechanisms by which DIM suppresses the inflammatory response.