肝脏枯否细胞活化及其介导肝脏炎症的调控机制

The activation of hepatic Kupffer cells and production of inflammatory cytokines play critical roles in liver inflammation, and the regulatory mechanism is the important scientific question. The subscriber focused on the regulation of liver inflammation and carcinogenesis, and cancer progression, and has published papers in Cell, Cancer Cell, Nature Immunology, Cell Research, J.Immunol as first, co-first, and co-corresponding authors. Among them, the subscriber has suggested the important roles of DDX family members in the regulation of inflammation and carcinogenesis. In this study, based on our previous works, we used siRNA library functional screening strategy to knockdown the expression of DDX family members individually, and found that knockdown of DDX39, DHX58, or DDX60 significantly influenced inflammatory cytokine IL-6 production and effects. Hence, we intend to investigate the regulatory mechanisms of these DDX family members in the activation of Kupffer cells, production of inflammatory cytokine IL-6, the effects of IL-6, and the regulation of liver inflammation in mouse models, so as to suggest new mechanisms and therapeutic targets for liver inflammation.

肝脏枯否细胞活化及炎症因子表达在肝脏炎症中发挥核心作用，其炎症因子表达和效应的分子调控机制是其中关键的科学问题。申请人长期从事肝脏炎症和肿瘤发生以及肿瘤进展的调控机制研究，以第一、共同第一和共同通讯作者发表Cell、Cancer Cell、Nature Immunology、Cell Res、J.Immunol等论文，其中尤其关注了DDX家族分子在炎症调控和炎癌转化中的作用。本研究拟在前期基础上，通过小干扰RNA文库功能性筛选策略，逐一敲减DDX家族分子的表达，筛选在枯否细胞炎症因子表达和效应中发挥的重要调控作用的DDX家族分子，发现DDX39、DHX58、DDX60等分子调控重要炎症因子IL-6表达和效应的作用，并拟进一步研究其调控IL-6表达和效应的分子机制。此外，通过结合肝脏炎症小鼠模型，探求这些分子调控肝脏炎症疾病进展的作用及干预靶点价值，以期为肝脏炎症提出调控新机制和干预新思路。

本项目按照申请书中研究计划执行，探讨了DDX家族分子DDX58在肝脏区域免疫肝脏炎症和炎癌转化中的功能及机制，发现肝癌祖细胞中DDX58的表达降低，及其通过活化IL-6炎症因子效应信号通路，促进肝癌发生的功能和机制。本工作还发现肝癌祖细胞中GNAS的胞内定位发生改变，从胞膜移位至胞浆从而促进STAT3磷酸化活化和肝癌发生，及其促进肝脏炎癌转化的机制。此外，还发现肝细胞中miR-199，通过抑制肝细胞凋亡和肝脏炎症环境，进而抑制肝脏炎癌转化的分子机制。关于DDX家族分子DDX58在肝脏炎症调控中的工作，目前已投稿至Nature Cancer期刊，申请人为末位通讯作者，已获修回并处于补实验过程中。关于GNAS在肝癌祖细胞中定位改变并促进IL-6效应的工作，申请人为末位通讯作者，目前已获Hepatology期刊原则接受。关于miR-199调控肝细胞凋亡和肝脏炎癌转化的工作，申请人以末位通讯作者已于2020年发表于Oncogenesis期刊。