樱桃汁和草莓汁激活Nrf2信号通路对砷诱导的人支气管上皮细胞损伤的保护作用

Juices of cherry and strawberry confer protection of human bronchial epithelial cells against arsenic-induced toxicity via activation of Nrf2 signaling pathway

目的研究草莓汁和樱桃汁对NF-E2相关因子2(Nrf2)信号通路的影响,以及两种果汁对砷诱导的人支气管上皮(HBE)细胞损伤的保护作用。方法选择人乳腺癌MDA-MB-231细胞系,分为空白对照组、萝卜硫素组,以及樱桃(草莓)汁1∶10、1∶20、1∶40和1∶80组(果汁稀释比例分别为1∶10、1∶20、1∶40和1∶80),采用抗氧化反应原件(ARE)荧光素酶报告基因和Westerm blotting筛选并确证两种果汁对Nrf2信号通路的影响;选择HBE细胞,分为空白对照组、萝卜硫素组,以及樱桃(草莓)汁1∶10、1∶20、1∶40组(果汁稀释比例分别为1∶10、1∶20和1∶40),采用QuantiChrom谷胱甘肽(GSH)试剂盒测定两种果汁对内源性抗氧化剂GSH水平的影响;采用MTT法和细胞转染技术评价两种果汁对砷诱导的HBE细胞的保护作用。结果草莓汁和樱桃汁能够剂量依赖地增强ARE荧光强度,上调MDA-MB-231细胞中Nrf2及其下游基因NADPH苯醌氧化还原醇(NQO1)和γ-谷氨酰半胱氨酸合成酶(γGCS)蛋白的表达;两种果汁能够提高HBE细胞内源性抗氧化剂GSH水平;两种果汁和砷处理HBE细胞后,果汁预处理的细胞生存率高于砷单独处理的细胞生存率,两种果汁表现出对砷诱导细胞毒性的保护作用,而这种保护作用在转染Nrf2-siRNA后消失。结论草莓汁和樱桃汁通过激活Nrf2信号通路抑制砷诱导的细胞毒性,对HBE细胞具有保护作用。

Objective To investigate the effects of cherry and strawberry juices on NF-E2-related factor 2（Nrf2）signa-ling pathway,and to evaluate their protection effects on arsenic-induced toxicity in human bronchial epithelial （HBE） cells.Methods Human breast cancer 23 1 cells were randomly divided into the control group,sulforaphen treated group,and juice treated groups （juice dilution ratios were 1∶10,1∶20,1∶40 and 1∶80,respectively）,and then antioxi-dant response element（ARE）luciferase reporter gene assay and Western blotting analysis were adopted for screening and identification of juice on Nrf2 signaling pathway;HBE cells were randomly divided into the control group,sul-foraphen treated group,and juice treated groups （juice dilution ratios were 1∶10,1∶20,and 1∶40,respectively）,and then the QuantiChrom glutathione （GSH）assay kit were used to detect the intracellular GSH levels;MTT assay and cell trans-fection were carried out to evaluate their protection effects against arsenic-induced toxicity in HBE cells.Results Juices of cherry and strawberry increased the luciferase activity in a dose-dependent manner,enhanced the protein expression of Nrf2 and its downstream genes NADPH：quinone oxidoreduefase Ⅰ（NQO1 ）and gamma glutamyl cysteine synthetase （γGCS）in MDA-MB-231 cells,and up-regulated the intracellular GSH levels in HBE cells.Co-treatment with juice and arsenic evidently improved HBE cell survival in response to arsenic treatment alone,while the juices no longer pro-tected the HBE cells whose Nrf2 expression was koncked down by Nrf2-siRNA.Conclusion Juices of cherry and strawberry confer the protection effects on HBE cells against arsenic-induced toxicity in a Nrf2-dependent manner.