食品有害物苯并(a)芘通过介导FOXO4磷酸化诱导肝细胞自噬性损伤的机制研究

项目名称： 食品有害物苯并(a)芘通过介导FOXO4磷酸化诱导肝细胞自噬性损伤的机制研究

项目编号： No.31501584

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 食品科学、农学基础与作物学

项目作者： 袁莉

作者单位： 陕西师范大学

项目金额： 22万元

中文摘要： 苯并(a)芘（BaP）是食品熏、炸、烧、烤等加工过程中产生的典型有害物。研究BaP对机体的损害机制可为其毒性干预和食品安全控制体系构建提供科学依据。近期研究表明，BaP可通过诱发细胞自噬损伤机体组织，但相关作用机制鲜有报道。叉头转录因子FOXO是调控许多基因转录的开关，在细胞自噬中起核心作用，但其家族成员FOXO4对自噬的作用尚不十分清楚。本项目拟以BaP作用HL-7702人肝细胞为研究对象，以FOXO4为靶点，通过采用自噬抑制剂和激活剂、磷酸化抑制剂和激活剂、FOXO4小RNA干扰、双荧光素酶报告基因等手段检测自噬泡数量和形态、FOXO4磷酸化和启动子活性、自噬特征蛋白和基因等，分析BaP对FOXO4转录活性及FOXO4对自噬特征蛋白的影响，阐明BaP通过介导FOXO4磷酸化调节其转录活性继而诱导细胞自噬的分子机制。研究结果为揭示食品有害物BaP的自噬性毒性机制及危害干预提供新线索。

中文关键词： 苯并芘；细胞自噬；转录因子FOXO4；磷酸化；损伤机制

英文摘要： Benzo-a-pyrene (BaP) is produced in the smoking, frying, grilling and toasting process during food production as a typical pollutant. Study on the cytotoxicity mechanisms of BaP on body could provide scientific evidence for toxicity intervention and food safety control system building. Previously researches have shown that BaP caused body tissue damage by inducing autophagy, however, the mechanism is still very rare.The forkhead box transcription factor FOXO proteins are regulatory switch for many gene transcription with a key player in cell autophagy, but the action mechanism of family member FOXO4 in autophagy is unclear. This project plans to focus on BaP and human normal liver HL7702 cells. Using cell autophagy inhibitor and activator, phosphorylation inhibitor and activator, FOXO4 siRNA, and dual luciferase reporter gene to examine the number and form of autophagosome, the phosphorylation and promoter activity of FOXO4, and the levels of autophagy-related proteins and genes. This project also analyzes the role of BaP on FOXO4 transcriptional activity, and the effect of FOXO4 on the transcription of autophagy-related proteins. Furthermore, this study attempts to explore the molecular mechanism of BaP in inducing autophagy in HL-7702 cells via mediating the phosphorylation and transcriptional activity of FOXO4, which may contribute to new clues for the reveal of cytotoxicity mechanisms and targeted intervention.

英文关键词： Benzo-a-pyrene;Cell Autophagy;Transcription Factor FOXO4;Phosphorylation;Injury Mechanism