NF-κB在脂多糖诱导小鼠脓毒症急性肺损伤中对ANXA2表达的影响

Effect of nuclear transcription factor-κB(NF-κB)on annexin A2(ANXA2)expression in lipopolysaccharids(LPS)-induced acute lung injury(ALI)in mice with sepsis

目的观察脂多糖(LPS)诱导脓毒症急性肺损伤(ALI)小鼠肺组织中膜联蛋白A2(ANXA2)的表达水平,探讨ANXA2的表达与核转录因子-κB(NF-κB)信号通路的关系。方法健康雄性C57BL/6小鼠18只,随机分为空白对照组、脂多糖组(LPS组)及LPS+NF-κB抑制剂组(以下为抑制剂组),每组6只。抑制剂组腹腔注射NF-κB信号通路抑制剂吡咯烷二硫代甲酸铵(PDTC)50 mg/kg,1 h后LPS组及抑制剂组腹腔注射LPS 7.5 mg/kg,观察12 h,全身麻醉后采血并处死小鼠。HE染色观察肺组织病理学特征,测右肺中叶湿干重、计算湿/干重比值,ELISA法检测血清ANXA2及左肺肺泡灌洗液中ANXA2、肿瘤坏死因子-α(TNF-α)水平,免疫组化法检测肺组织ANXA2、NF-κBp65、p-NF-κBp65蛋白平均光密度(MOD)值,RT-qPCR检测肺组织中NF-κBp65、TNF-α及IL-6 mRNA相对表达量,WB检测肺组织ANXA2、NF-κBp65、p-NF-κBp65、Claudin1蛋白表达量。结果与空白对照组比较,LPS组肺组织病理损伤严重,可见细支气管上皮细胞坏死脱落、肺泡间隔增厚、肺泡腔内巨噬细胞和淋巴细胞渗出、少许出血。与空白对照组比较,LPS组右肺中叶湿/干重比值,血清ANXA2及肺泡灌洗液ANXA2、TNF-α水平,肺组织NF-κBp65、TNF-α及IL-6 mRNA相对表达量,肺组织ANXA2、NF-κBp65、p-NF-κBp65蛋白MOD值以及蛋白表达均显著升高(P<0.05),而Claudin1蛋白表达显著下降(P<0.05);与LPS组比较,抑制剂组以上各项观察指标均明显改善(P<0.05)。结论NF-κB信号通路在LPS诱导小鼠脓毒症相关ALI肺组织中可调控ANXA2的表达。

Objective To observe the expression of annexin A2(ANXA2)in lung tissues of lipopolysaccha-ride(LPS)-induced acute lung injury(ALI)mice,and to explore the relationship between the expression of ANXA2 and nuclear factor-κB(NF-κB)signaling pathway.Methods 18 healthy male C57BL/6 mice were randomly divided into control group,LPS group and LPS+NF-κB inhibitor group(the following was the inhibitor group),with 6 mice in each group.The mice in the inhibitor group were intraperitoneally in-jected with NF-κB signaling pathway inhibitor ammonium pyrrolidine dithiocarbate(PDTC)50 mg/kg,LPS group and inhibitor group were intraperitoneally injected with LPS 7.5 mg/kg 1 h later,observed for 12 h,blood samples was collected after general anesthesia,and the mice were killed.Lung histopathologi-cal features were observed with HE staining,the middle lobe of the right lung was measured by wet and dry weight,and the ratio of wet and dry weight was calculated.The concentrations of ANXA2 in serum and ANXA2 and TNF-αin the left lung alveolar perfusion fluid were measured by ELISA.The mean of optical density(MOD)of ANXA2,NF-κBp65 and p-NF-κBp65 in lung tissue was determined by immuno-histochemistry,and the relative mRNA expression of NF-κBp65,TNF-αand IL-6 in lung tissue was deter-mined by RT-qPCR.The relative expression levels of ANXA2,NF-κBp65,p-NF-κBp65 and Claudin1 in lung tissues were determined by WB.Results Compared with control group,the lung histopathological injury in LPS group was severe,including necrosis and exfoliation of bronchiolar epithelial cells,thicken-ing of alveolar septum,extravasation of macrophages and lymphocytes in the alveolar cavity and occasional bleeding.In LPS group,compared with control group,the ratio of wet/dry weight in the middle lobe of right lung,the concentration levels of ANXA2 in serum and ANXA2 and TNF-αin alveolar perfusion flu-id,the relative mRNA expression levels of NF-κBp65,TNF-αand IL-6 in lung tissue,the protein MOD values of ANXA2,NF-κBp65 and p-NF-κBp65 and their relative expression levels in lung tissues were sig-nificantly increased(P<0.05);While the relative expression of Claudin1 protein in lung tissues was sig-nificantly decreased(P<0.05).Compared with LPS group,the above observation indexes in inhibitor group were significantly improved(P<0.05).Conclusion NF-κB signaling pathway regulates ANXA2 expression in LPS-induced mouse sepsis associated ALI lung tissue.