Nrf2基因缺失对子鼠肺组织发育的影响研究

THE EFFECTS OF NUCLEAR FACTOR ERYTHROID 2 RELATED FACTOR 2 GENE DELETION ON LUNG TISSUE DEVELOPMENT OF NEONATAL MICE

目的探究Nrf2基因缺失对子鼠肺组织发育的影响。方法分别采用C57BL/6孕鼠(WT)和Nrf2基因缺失孕鼠(Nrf2-/-)构建IUGR子鼠模型。根据出生体重将子鼠分为四组:WT Normal,WT IUGR,Nrf2-/-Normal,Nrf2-/-IUGR。观察各组体重变化,出生后2、4周分别取材,观察脑/肝比和肺组织形态变化;肺组织切片免疫组化染色进行CD31阳性细胞计数;qRT-PCR检测肺组织VEGFα和VEFR2 mRNA的相对水平。结果Nrf2-/-IUGR子鼠出生体重、7d、14d体重均显著低于WT IUGR子鼠(P<0.05);14d时Nrf2-/-子鼠脑/肝比均低于WT子鼠,28d时Nrf2-/-Normal子鼠高于WT Normal子鼠(P<0.05)。HE染色显示,Nrf2-/-子鼠肺泡塌陷和肺泡壁增厚的现象较WT子鼠更加严重。Nrf2-/-小鼠与WT小鼠的肺泡平均线性截距与CD31阳性细胞计数均有显著差异(P<0.05)。14d时,与WT子鼠相比,Nrf2-/-子鼠肺组织中VEGFα和VEFR2的mRNA的表达均显著上调(P<0.05)。结论Nrf2基因缺失可加重子鼠肺组织破坏和肺血管新生减少,诱导严重的肺发育不良。

Objective To explore the effects of Nrf2 gene deletion on lung tissue development of neonatal mice.Methods C57BL/6 pregnant mice(WT)and Nrf2-/-pregnant mice were used to build model mice of IUGR.According to birth weight,the neonatal mice were divided into four groups:WT Normal,WT IU-GR,Nrf2-/-Normal,and Nrf2-/-IUGR.Body weight changes were recorded weekly.Cerebrum to liver ratio and microscopic morphology of lung tissue was measured at 2,4 weeks after birth.Immunohisto-chemical staining was used to observe the expression level of CD31 positive cells in lung tissue section and qRT-PCR was used to detect the expression of VEGFαand VEGFR2 mRNA in lung tissue.Results Body weight of Nrf2-/-IUGR mice at day 0,7,14 after birth was significantly lower than those of WT IUGR mice(P<0.05).At day 14 after birth,cerebrum to liver ratio of Nrf2-/-normal mice was significantly lower than that of WT normal mice,but at day 28 the cerebrum to liver ratio of Nrf2-/-normal mice was significantly higher than that of WT normal mice(P<0.05).HE staining showed that more collapse and thicker alveolar wall was observed in the lung tissue section of Nrf2-/-mice than those of WT mice.There was significantly difference in the mean linear inter-cept of alveolar and CD31 expression between WT mice and Nrf2-/-mice.At day 14,compared to WT group,mRNA expression of VEGF-αand VEFR2 in lung tissue of Nrf2-/-mice was significantly up-reg-ulated(P<0.05).Conclusion Nrf2 gene deletion affected lung development of mice with more lung tissue destruction and less lung angiogenesis.