PHLDA3介导IRE1-Xbp1通路在内质网应激肝损伤的调控作用及分子机制研究

Our previous clinical observations found that significant inflammation infiltration, oxidative damage and metabolic disorders occurred in injured liver tissue of patients, gradually developing as further deteriorative condition. It indicates that screening of a effective regulatory effector targeting phenotypic change of liver injury may be a substitute avenue for anti-liver damage. Studies have shown that the maintenance of homeostasis of the endoplasmic reticulum plays an important role in normal physiological function of hepatocytes. However, functional molecular signaling pathways responsible for liver cell fate are still with specific conclusion when occurring in endoplasmic reticulum stress-induced liver injury. This project proposes a scientific hypothesis that endoplasmic reticulum stress induces activation of PHLDA3 effector, which further accelerates the cell death through regulating associated signal pathway and results in increased liver disease. Therefore, this project will specifically down-regulated expression of liver PHLDA3 activity (in vivo and in vitro models) cells through gene silencing technology (shRNA and siRNA), while three classical mouse models of liver injury are established. By using variety of molecular biology techniques, collaboratively analyse PHLDA3 on expressions of key upstream regulators and downstream effectors (gene and protein levels) associated with IRE1-Xbp1 pathway in endoplasmic reticulum stress-induced liver impairment, as well as explore relevant molecular mechanisms involved, thus providing a new treatment strategy for clinical liver injury.

我们前期临床观察发现，病人肝损伤组织有明显的炎症浸润、氧化应激和代谢紊乱，并逐渐发展为进一步的损伤病情，提示筛选有效的调控因子靶标肝损伤表型分化是一个有前景的抗肝损伤途径。研究表明，维持内质网稳态在肝细胞正常功能中发挥重要的生理作用。然而，内质网应激致肝损伤发生后，负责肝细胞存活的功能分子信号通路还没有具体定论。本项目提出了科学假设，即内质网应激促使PHLDA3因子激活，后者进一步通过调控相关信号通路加速诱导肝细胞死亡，从而加重肝病病情。故本项目将通过基因沉默技术（shRNA和siRNA）特异性地下调肝细胞PHLDA3表达活性（体内和体外模型），同时建立三种经典肝损伤小鼠模型。经各种分子生物技术手段，协同分析PHLDA3对内质网应激肝损伤IRE1-Xbp1通路中关键的上游调节因子与下游效应因子（基因与蛋白水平）表达的影响，并探究相关的分子调控机制，从而为临床抗肝损伤治疗提供新的策略。

通过本项目实施（No. 81660091），我们课题组揭示了PHLDA3介导IRE1-Xbp1通路在内质网应激肝损伤的分子调控作用及机制，为临床抗肝损伤治疗提供新的策略。在本课题组全体科研人员的努力下，申请人以第一作者/通讯作者及其他作者成功发表较高水平SCI论文9篇（高被引论文1篇），科研成果得到了国内专家的一致认可与。实用新型专利1项。在项目实施期间，本课题组努力实践临床观察-基础验证-转化预测的主流研究策略，进而为本项目的转化前景奠定基础。课题组成员及参与科研的学生已熟练掌握细胞培养、免疫染色、分子生物学、组织细胞学及转录组学等重要科研技能，有力地促进本团队今年的科研发展。在项目实施期间，也加强了本课题组与国内优秀科研团队的交流和合作。