基于HIF通路与外泌体非编码RNA的砷暴露所致健康危害机制及风险评估研究

Arsenic exposure is a common hazardous factor in environment and occupation, which seriously endangers human’s health. With the in-depth understanding of the toxicity pathway (TP) and the adverse outcome pathway (AOP), the application of the research results based on the mechanisms of harmful factors-caused health hazards are more and more important. Our previous investigations have found that hypoxia inducible factor (HIF) pathway and the exosome non-coding RNA play important roles in damages induced by arsenic exposure. Using the following three models. (i) Cell experiments, the treatememt of lung and liver epithelial cells by arsenite, their secreted exosomes treated or co-cultured with lung fibroblasts or hepatic stellate cells, in the presence or absence of various interventions, respectively; (ii) Animal models, arsenic poisoning and carcinogenesis induced by different exposures of coal-burning, drinking-water, and embryo. (iii) Populations, established local high arsenic exposed population and early life exposure to arsenic cohort, we are going to investigate the molecular mechanisms of arsenic exposure-induced health hazard (the chronic obstructive pulmonary disease, cirrhosis of the liver, and cancer, etc) based on hypoxia inducible factor pathway and exosome non-coding RNA, in order to find early molecular events as an early, sensitive, and specific biomarkers for the risk assessment of arsenic exposure. The results of this investigation will not only further clarify the mechanism of health hazards caused by arsenic exposure, but also can identify early warning molecular markers for risk assessment, which is of important scientific significance and practical value to promote the precision control strategy.

砷暴露是常见的环境与职业有害因素，其严重危害人类健康。随着对毒性通路(TP)和有害结局路径(AOP)的深入了解，基于有害因素所致健康危害机制的研究结果应用于风险评估越来越受到重视。本项目在前期发现缺氧诱导因子(HIF)通路与外泌体非编码RNA在砷暴露所致损害中具有重要作用基础上，拟应用砷处理肺与肝上皮细胞，或用其分泌的外泌体处理或共培养肺成纤维细胞或肝星状细胞，并采取多种干预措施等细胞实验；燃煤型和饮水型及胚胎染毒的砷中毒和致癌动物模型；已建立的地方性高砷暴露人群和生命早期砷暴露人群队列，探讨HIF通路与外泌体非编码RNA在砷暴露所致慢性阻塞性肺病和肝硬化及肿瘤等健康危害的分子机制，发现早期分子事件作为早期敏感特异生物标志，应用于砷暴露的健康风险评估。研究结果不仅将进一步阐明砷暴露所致健康危害的机制，且可获得早期预警分子标志应用于风险评估，对推进精准防治策略具有重要科学意义和实用价值。

该项目利用不同水平亚砷酸钠慢性处理小鼠所致肝和肺纤维化动物模型，不同水平亚砷酸钠处理肝上皮细胞、肺支管上皮细胞、巨噬细胞、T细胞不同时间及其对肝星状细胞与肺肌成纤维细胞激活的影响，并采用一系列干预措施，结合砷中毒病区不同水平砷暴露人群的研究结果，创新性发现：（1）EVs miR-15b和circRNA_100284介导巨噬细胞和正常肝细胞与肝癌细胞间cross-talk紊乱及NF-κB调控miR-155和HIF-2α调控miR-191介导EMT和CSCs表型在砷暴露所致肝细胞恶性转化和肝癌发生发展中具有重要作用。（2）miR-21通过调控靶基因PDCD4与Twist1结合介导EMT和HIF-2α通过miR-191调控BASP1/WT1在砷暴露所致HBE细胞恶性转化及肺癌发生发展中具有重要作用。（3）miR-379-5p调控GSDMD介导肝细胞焦亡、外泌体lncRNA MALAT1调控miR-26b和miR-21调控PTEN介导巨噬细胞极化、miR-21调控HIF-1α介导肝细胞与肝星状细胞间cross-talk紊乱及miR-21通过PTEN/PI3K/AKT通路调节T细胞糖酵解及lncRNA HOTAIR调控miR-17-5p细胞Th17分化，通过激活肝星状细胞参与砷暴露所致肝纤维化。（4）LncRNAH19调控let-7a介导巨噬细胞M2极化、肺上皮细胞EVs miR-21介导糖酵解和H3K18乳酸化修饰调控YTHDF1通过m6A促进NREP水平及METTL3调控lncRNA E230001N04Rik m6A修饰介导肺泡上皮细胞衰老参与砷暴露所致肺肌成纤维细胞分化及肺纤维化。（5）砷暴露人群体内砷负荷增高亦存在多种微量元素异常，人群HA和CA水平与肝损伤风险呈正相关。（6）应用TP和AOP原理发现了一些重要分子起始事件、关健事件分别与砷暴露所致肝癌、肺癌、肝纤维化和肺纤维化四种有害结局的风险及意义。.研究结果揭示了砷暴露所致肝和肺组织肿瘤及纤维化的发病机制及风险，对于寻找控制砷暴露所致危害和防治的早期生物标志及发现新的防控措施具有较大科学意义和潜在应用价值，对于推动环境有害因素所致机体损害机制及风险评估具有重要学术价值。研究成果被国际权威CTD毒理学数据库收录，已发表论文28篇，其中SCI论文23篇，获省部研究成果2项，获后续国家级项目3项，培养研究生23名。