lncRNA Rmrp调控DDX5介导Th17分化在砷所致肝纤维化中作用机制研究

Arsenic exposure causes seriously body damages, among which liver fibrosis is one of the most common diseases, but the molecular mechanism is still unclear. The differentiation of T helper cell 17 (Th17) and its interleukin-17 (IL-17) are associated with various diseases. However, there are few publishes about the roles of Th17 differentiation in the mechanisms of body damages induced by environmental harmful factors. On the basis of the previous researchs, we are going to investigate the mechanism of Th17 differentiation mediated by lncRNA Rmrp-regulated DDX5 in arsenic-induced hepatic fibrosis in two levels of cells and animals by following experiments: After T lymphocyte were treated by arsenite and the up-regulation or down-regulation of lncRNA Rmrp and DDX5, T lymphocyte lncRNA Rmrp and DDX5 levels, IL-17 secretion levels, and the indicators of Th17 differentiation were detected. The index of hepatic stellate cell activation and fibrosis were determined after hepatic stellate cells were co-cultured with different treated T lymphocyte, which was treated by IL-17 recombinant protein or neutralizing antibody. Hepatic fibrosis of mice were observated after the C57BL/6 mice and lncRNA Rmrp-/- mice were chronically treated by arsenite. Our results will reveal some molecular mechanisms of arsenic-induced hepatic fibrosis, which will provide scientific basis to find early biomarkers and novel measures of preventing and treating arseniasis.

砷暴露引起严重的机体损害，其中肝纤维化是最常见疾病之一，但其分子机制尚不清楚。辅助性T细胞17(Th17)分化及分泌的白介素17(IL-17)与多种疾病发生发展有关，而其在环境有害因素所致机体损害中的作用机制研究报道甚少。本项目在前期研究基础上，拟探讨亚砷酸钠及上调或下调lncRNA Rmrp和DDX5水平处理后，分别检测T淋巴细胞lncRNA Rmrp和DDX5水平、IL-17分泌水平和Th17分化的指标；将以上不同处理的T淋巴细胞与肝星状细胞共培养，并检测上调或下调IL-17后肝星状细胞激活及纤维化指标；观察亚砷酸钠慢性处理野生型和lncRNA Rmrp敲除型小鼠的肝纤维化情况。从正向和反向在细胞和动物水平探讨lncRNA Rmrp调控DDX5介导Th17分化在砷所致肝纤维化中作用机制。揭示砷所致肝纤维化的部分分子机制，为寻找砷所致肝损害早期生物标志及发现新的防治措施提供科学依据。

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之一，长期低水平砷暴露可引起肝纤维化、肝硬化甚至肝癌，但其分子机制尚不清楚，目前也缺少有效的早期生物标志与防控措施。.该项目以表观遗传学为切入点，利用不同剂量亚砷酸钠（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T淋巴细胞和肝细胞及其对肝星状细胞（HSCs）激活的影响，并采用miR-21基因敲除和lncRNA HOTAIR基因沉默小鼠及一系列干预处理，在细胞和整体动物水平，从多角度、多层次，阐明T细胞免疫调节及肝细胞与HSCs间cross-talk在砷暴露所致肝纤维化中作用及其表观机制。.创新性发现：①miR-21通过PTEN/PI3K/AKT通路调节T细胞糖酵解而引起Th2极化，进而通过释放IL-13，促进HSCs的激活，参与砷暴露所致肝纤维化；②lncRNA HOTAIR调控miR-17-5p介导CD4+ T细胞Th17分化在砷所致肝纤维化中发挥重要作用；③miR-21通过pVHL调节HIF-1α泛素化降解，进而影响HIF-1α/VEGF信号通路，通过释放促纤维化因子VEGF介导肝细胞与HSCs间cross-talk异常在砷暴露所致肝纤维化过程中具有重要作用。.研究结果揭示了砷暴露所致肝纤维化的发病机制，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。研究成果达到国内领先水平，在环境与健康领域影响力较大的Journal of Hazardous Materials、Ecotoxicology and Environmental Safety 和Chemosphere等杂志发表SCI论文3篇，总影响因子达到30.296；发表于中科院1区杂志1篇，2区杂志2篇，且均为JCR分区1区杂志，其中第一标注2篇，第二标注1篇，后续又获得了中国博士后基金面上项目1项，并协助指导博士生1名和硕士生2名。