PM2.5对大鼠肺组织Nrf2/HO-1通路的影响及维生素C的干预作用

Effect of PM2.5 on Nrf2/HO-1 pathway in lung tissue of rats and intervention of vitamin C

目的:观察PM 2.5对大鼠肺组织Nrf2/HO-1通路的影响及维生素C的干预作用。 方法:选用雄性Wistar大鼠40只,采用随机数字表法分为5组,分别为空白对照组、生理盐水对照组、PM 2.5染毒组及维生素C低、高剂量组。PM 2.5染毒组给予PM 2.5气管滴注,每周1次,共4周;维生素C组染毒同PM 2.5染毒组,维生素C低、高剂量组于实验开始后每天分别给予10 g/L、30 g/L维生素C 10 ml/kg灌胃至实验结束。最后一次气管滴药结束24 h后处死大鼠。光镜下观察大鼠肺组织形态,用蛋白质印迹、聚合酶链反应分别检测大鼠肺组织中Nrf2、HO-1蛋白及HO-1 mRNA表达水平。 结果:与空白对照组、生理盐水对照组比较,PM 2.5染毒组大鼠肺组织中HO-1、Nrf2总蛋白及核蛋白均下降,HO-1 mRNA表达下降( P值均<0.05);给予维生素C干预后大鼠肺组织中HO-1、Nrf2总蛋白及核蛋白及HO-1 mRNA表达明显升高( P值均<0.05)。 结论:PM 2.5可通过影响Nrf2/HO-1信号通路的功能引起肺组织氧化损伤,抗氧化剂维生素C具有保护作用。

Objective Td explore the effect of PM2.5 on Nrf2/HO-1 pathway in lung tissue of rats and intervention of vitamin C.Methods Forty healthy adult male Wistar rats were selected and divided into five groups using random number table method:control group,normal saline group,PM2s group,low dose vitamin C group and high-dose vitamin C group.The rats in PM2.5 group,low-dose and high-dose vitarmin C groups were given trachea instillationof 1ml/kg PM2.5(75 g/L)suspension liquid once a week for four weeks.The rats in low dose and high-dose vitamin Cgroups were respectively given 10 ml/kg vitamin C(10 g/L and 30 g/L)every day during the experiment.The rats were killed 24 hours later after the last time of trachea instillation.The lung tissue morphology of rats was observed under light microscope The protein expressions of Nrf2 and HO-1 and mRNA level of HO-1 in the lung tissue were detected by W estern blotting and reverse transcription-polymerase chain reaction.Results Compared with control group,normal saline group,the protein expressions of Nrf2 and HO-1 and mRNA level of HO-1 in the lung tissue of PM2:group were decreased(all P<0.05),they were increased significantly in vitamin Cgroup(all P<0.05).Conclusions PM2s can cause oxidative damage of lung tissue by Nrf2/HO-1 signaling pathway.Vitamin C may act as an antioxidant by upregulating Nrf2/HO-1 pathway.