lncRNA H19及外泌体在砷所致肝硬化和肝癌中的作用机制研究

Arsenic contamination can cause serious body damages and tumors, among which liver cirrhosis and liver cancer are the most common diseases, but their molecular mechanisms are not clear. Long non-coding RNA (lncRNAs) and exosome, which transmits information between cells and cells, play important regulation roles in many diseases and tumors. However, there are few publishes about their mechanisms of the damages and tumors induced by environmental chemicals. Based on our preliminary results that epithelial-mesenchymal transition（EMT）and transformation of human hepatic epithelial cells were induced by arsenite, we are going to investigate the roles and molecular mechanisms of lncRNA H19 and exosome in arsenic-induced liver cirrhosis and hepatocellular carcinoma by using the following three models. (i) Cell model: liver epithelial cells were treated by arsenite and hepatic stellate cells were treated by exosomes derived from transformed liver epithelial cells or were co-cultured with liver epithelial cells, which were influenced by the treatments of sense or antisense lncRNA H19、miR-138, miR-29b-3p, or rescue experiment, respectively; (ii) Animal model: the CD1 mice model of liver damages and tumorigenesis induced by arsenite; (iii) Population:the population exposed to different levels of arsenic. Our results will be helpful to understand the molecular mechanisms underlying liver cirrhosis and hepatic carcinogenesis induced by arsenic, which will provide new clues to find early biomarkers and novel measures of preventing and treating arseniasis.

砷化物污染可引起严重的机体损害甚至肿瘤，其中肝硬化和肝癌是最常见的疾病，但其分子机制尚不清楚。长链非编码RNA(lncRNAs)和在细胞与细胞之间传递信息的外泌体在多种疾病及肿瘤中具有重要调控作用，而其在环境化学物所致损害和肿瘤中的作用机制研究报道甚少。本项目在已发现亚砷酸钠慢性处理引起肝上皮细胞发生上皮间质转化(EMT)及恶性转化的基础上，分别通过亚砷酸钠处理人肝上皮细胞、用从供体肝上皮细胞培养液中提取的外泌体或共培养等处理受体肝星状细胞，并观察正义和反义lncRNA H19、miR-138和miR-29b-3p及挽救实验对其影响；砷所致小鼠肝损害和致癌模型及不同程度砷暴露人群，分别从反向和正向在细胞、动物及人群三个层次探讨LncRNA H19及外泌体在砷所致肝硬化和肝癌中的作用及分子机制，以揭示砷引起肝硬化与肝癌的部分机制，为寻找砷所致危害的早期生物标志和发现新的防治措施提供新线索。

环境砷暴露所致砷中毒是常见的环境污染所致疾病与地方病，严重危害我国及世界多个国家和地区人民群众的健康，已经成为全球广泛关注的公共卫生问题之一。肝脏是砷暴露导致损害的主要靶器官，长期砷暴露可引起肝组织纤维化甚至肝癌，但其分子机制尚不清楚，而且也缺少砷中毒的早期生物标志与防控措施。.该项目利用不同水平亚砷酸钠（NaAsO2）慢性处理小鼠所致肝纤维化的动物模型；不同水平NaAsO2处理巨噬细胞、肝上皮细胞不同时间及其对肝星状细胞激活的影响，并采用一系列干预措施，结合不同水平砷暴露人群研究结果，在细胞和整体动物及人群水平，探讨了砷暴露所致肝癌和肝纤维化的分子机制。.创新性发现以下研究结果：（1）细胞外囊泡（EVs）miR-15b介导巨噬细胞与肝癌细胞之间的cross-talk紊乱在砷暴露所致肝细胞恶性转化和肝癌发生发展及侵袭转移中具有重要作用。（2）外泌体lncRNA MALAT1调控miR-26b介导肝细胞与肝星状细胞cross-talk紊乱参与了砷暴露所致肝纤维化。（3）miR-21调控PTEN介导巨噬细胞极化通过激活肝星状细胞参与砷暴露所致肝纤维化。（4）氧化应激诱导肝细胞NLRP3谷胱甘肽化修饰在砷暴露所致肝纤维化中具有重要作用。.研究结果揭示了砷暴露所致肝癌和肝纤维化的分子机制，对于寻找控制砷暴露所致危害和砷中毒防治的早期生物标志及发现新的防控措施具有较大的科学意义和潜在的应用价值，以为预防和控制砷暴露所致健康危害提供理论基础和科学依据。