TNFR-Fc上调Nrf2表达改善小鼠急性肺损伤氧化损伤的作用

TNFR-Fc up-Regulates Nrf2 Expression and Improves Oxidative Damage in Acute Lung Injury Mice

目的探讨肿瘤坏死因子受体-Fc融合蛋白(tumor necrosis factor receptor-Fc fusion protein,TNFR-Fc)逆转急性肺损伤(acute lung injury,ALI)过程中受抑制的红系衍生的核因子2相关因子2(nuclear factor erythroid-2 related factor 2,Nrf2)表达,并纠正肺组织氧化损伤的作用。方法小鼠分为对照组、ALI组、干预组,以气管内滴入脂多糖(lipopolysaccharide,LPS)复制ALI小鼠模型,干预组小鼠腹腔内注射TNFR-Fc,酶联免疫吸附试验(enzyme-linked immunosorbent assay,ELISA)法检测血清/支气管肺泡灌洗液(broncheo-alveolar lavage fluid,BALF)中白细胞介素6(interleukin 6,IL-6)与IL-10浓度。Western blot检测肺组织Nrf2表达水平,比色法检测肺组织丙二醛(malondialdehyde,MDA)与总抗氧化能力(total antioxidant capacity,T-AOC)。实时荧光逆转录定量聚合酶链反应(real-time reverse transcription quantitative polymerase chain reaction,RT-qPCR)检测肺组织氧化酶转录水平。结果干预组小鼠血清与BALF的IL-6浓度较ALI组显著下降(血清:1073.48±156.062 vs.1739.03±423.206,P<0.05;BALF:468.37±123.615 vs.1440.15±184.585,P<0.05),BALF中IL-10浓度与ALI组相仿(P>0.05)。干预组小鼠肺组织Nrf2相对表达水平(11.66±1.317 vs.3.00±0.184,P<0.001)与T-AOC(0.26±0.015 vs.0.22±0.020,P=0.034)高于ALI组,MDA浓度稍低于ALI组(22.51±3.875 vs.25.40±3.239,P=0.288)。干预组黄嘌呤氧化酶(xanthine oxidase,XO)基因转录强度显著低于ALI组(1.09±0.361 vs.2.46±0.650,P=0.008),而超氧化物歧化酶(superoxide dismutase,SOD)基因转录水平相仿(P>0.05)。结论LPS致ALI时Nrf2表达水平下降,伴随肺组织氧化损伤,而通过TNFR-Fc降低炎症反应强度后,Nrf2表达水平增高,逆转ALI的肺组织氧化损伤。

Objective To investigate the role of tumor necrosis factor receptor-Fc fusion protein(TNFR-Fc)in the reversal of acute lung injury(ALI)inhibits nuclear factor erythroid-2 related factor 2(Nrf2)expression and corrects oxidative damage in lung tissue.Methods Mice were divided into control group,ALI group and intervention group.The model of ALI was reproduced by intratracheal instillation of lipopolysaccharide(LPS).TNFR-Fc was intraperitoneally injected into mice in the intervention group,and concentrations of interleukin 6(IL-6)and IL-10 in serum/broncheo-alveolar lavage fluid(BALF)were detected by enzyme-linked immunosorbent assay(ELISA).Nrf2 expression level was detected by Western blot.Malondialdehyde(MDA)and total antioxidant capacity(T-AOC)in lung tissues were detected by colorimetry.The gene transcription level of oxidative enzymes in lung tissues were detected by real-time reverse transcription quantitative polymerase chain reaction(RT-qPCR).Results IL-6 concentrations of serum and BALF in intervention group were significantly lower than ALI group(serum:1073.48±156.062 vs.1739.03±423.206,P<0.05;BALF:468.37±123.615 vs.1440.15±184.585,P<0.05),while IL-10 concentration in BALF was similar to ALI group(P>0.05).The relative expression levels of Nrf2(11.66±1.317 vs.3.00±0.184,P<0.001)and T-AOC(0.26±0.015 vs.0.22±0.020,P=0.034)in lung tissues of mice in intervention group were higher than those in ALI group.MDA concentration was lower in intervention group than that in ALI group(22.51±3.875 vs.25.40±3.239,P=0.288).The transcription level of xanthine oxidase(XO)gene in intervention group was significantly lower than that in ALI group(1.09±0.361 vs.2.46±0.650,P=0.008),the superoxide dismutase(SOD)gene transcription level was similar between ALI group and intervention group(P>0.05).Conclusion The expression level of Nrf2 decreases when LPS induced ALI,leading oxidative damage of lung tissue.After reducing the intensity of inflammatory response by TNFR-Fc,the expression level of Nrf2 increases,reversing the oxidative damage of ALI lung tissue.