大麻素受体2缺失促进伴刀豆球蛋白A所致急性肝损伤小鼠肝巨噬细胞的增殖与活化

Cannabinoid receptor 2 deletion promotes proliferation and activation of hepatic macrophages in mice with acute liver injury induced by concanavalin A

目的探讨大麻素受体2(CB2)缺失对伴刀豆球蛋白A(ConA)所致急性肝损伤小鼠肝巨噬细胞的影响。方法 20只8周龄野生型(WT)C57BL/6J雄性小鼠分为对照组、模型组; 20只CB2基因敲除(CB2^(-/-))C57BL/6J雄性小鼠随机分为CB2^(-/-)对照组、 CB2^(-/-)模型组。WT和CB2^(-/-)小鼠模型组尾静脉注射ConA(20 mg/kg)复制小鼠急性肝损伤模型,对照组注射等量PBS。造模9 h后,留取血清检测丙氨酸氨基转移酶(ALT), HE染色观察各组肝损伤情况, Western blot法分别检测肝巨噬细胞相关CD68、肿瘤坏死因子α(TNF-α)蛋白水平,免疫组织化学染色法检测肝组织F4/80的表达。结果与两组对照组相比,两组模型组小鼠肝脏损伤程度严重,血清ALT明显增高,肝组织F4/80阳性表达及CD68、 TNF-α蛋白水平均明显增强;与WT模型组比较, CB2^(-/-)模型组小鼠肝损伤程度和损伤面积增加,血清ALT有所增高,肝组织F4/80阳性表达以及CD68和TNF-α蛋白水平均有所升高。结论 CB2基因缺失促进ConA所致急性肝损伤小鼠肝脏中巨噬细胞的增殖与活化。

Objective To investigate the effect of cannabinoid receptor 2(CB2)gene deletion on liver macrophages in mice with acute liver injury induced by concanavalin A(ConA).Methods The mice with gene deletion were identified by PCR.Twenty 8-week-old wild-type C57BL/6J male mice were randomly divided into control group and model group.Twenty C57BL/6J male mice with the deletion of CB2 were divided into CB2-/-control group and CB2-/-model group.The wild-type and CB2-/-mouse model groups were injected with ConA 20 mg/kg via tail vein to replicate the model of acute liver injury,and the control groups were injected with the same amount of PBS.Nine hours after modeling,the serum was taken for the detection of alanine aminotransferase(ALT);the degree of liver injury in each group was observed by HE staining;the expression levels of CD68 and TNF-alpha proteins related to liver macrophages were detected by Western blotting;and the positive level of F4/80 in the liver tissue was detected by immunohistochemistry.Results Compared with the two control groups,the liver injury degree of mice in the model groups were serious;the serum ALT level significantly increased;the positive expression of F4/80 in the liver tissue;and the expression of CD68 and TNF-alpha proteins were significantly enhanced.Compared with the WT model group,the CB2-/-model group had an increase in the degree and area of liver injury,the serum ALT,the positive expression of F4/80 in the liver tissue,and the expression of CD68 and TNF-alpha proteins.Conclusion The deletion of CB2 gene increases the proliferation and activation of macrophages in the mice with ConA-induced acute liver injury.