组蛋白去乙酰化酶介导的自噬-NLRP3炎症小体轴对急性肝衰竭细胞焦亡途径的影响

Acute liver failure(ALF) is a critically disease with extremely high mortality. There is no good treatment in clinical practice. Several studies have shown that cell pyroptosis pathway is the central part of liver cell necrosis during pathogenesis of ALF. Autophagy-NLRP3 inflammasome axis plays a two-way regulation effects on cell pyroptosis pathway. Our previous study revealed that targeting knockdown or overexpression of histone deacetylase 2 (HDAC2) could accordingly up-regulate or down-regulate the autophagy gene ULK1. Through quantitative proteomics analysis, HDAC6 inhibitor could inhibit the expression of inflammasome-related genes Caspase-1 and GSDMDc-1 in the liver of ALF animal model. Meanwhile, both HDAC2 and HDAC6 inhibitors could ameliorate ALF. However, how HDACs regulate hepatocyte pyroptosis in ALF by the autophagy-NLRP3 inflammasome axis deserves further study. This study will be performed from three aspects of cell, animal and clinical experiments. LPS/D-gal will be used to interfere in hepatocyte cell line and in rat ALF model. HDACs inhibitor, shRNA and lentivirus will be used to study the modulation of histone acetylation, the changes of key molecular genes and protein expression in autophagy-NLRP3 inflammasome axis. Clinical peripheral blood samples from ALF patients will be also collected to verify the above changes. Through this study, we identify the HDAC2 negatively regulates autophagy and HDAC6 positively regulate the inflammasome activation, serially affecting pyroptosis pathway, and provide scientific basis for the treatment of ALF.

急性肝衰竭(ALF)是病死率极高的危重病症,临床无较好治疗方法。研究表明,自噬-NLRP3炎症小体轴对ALF肝细胞坏死中心环节——细胞焦亡有双向调控作用。前期基因测序靶向敲低和过表达组蛋白去乙酰化酶(HDAC)2基因,自噬基因ULK1会相应上调和下调;蛋白组学发现,HDAC6抑制剂可抑制ALF动物模型肝内炎症小体相关基因Caspase-1和GSDMDc-1;同时,HDAC2及HDAC6抑制剂均对ALF有治疗作用。但HDACs如何通过自噬-NLRP3炎症小体轴调控ALF细胞焦亡值得深入研究。本课题拟从细胞、动物及临床实验三个层面进行，LPS/D-gal处理肝细胞株和大鼠,予HDACs抑制剂、shRNA、慢病毒及焦亡抑制剂干预,明确组蛋白和该轴中关键分子的变化,并在临床中验证该变化。据此明确HDAC2负调控自噬及HDAC6正调控炎症小体活化,串联抑制细胞焦亡,为寻找ALF治疗方案提供科学依据。

急性肝衰竭（ALF）是病死率极高的危重病症，临床无较好治疗方法。研究表明，自噬-NLRP3炎症小体轴对ALF肝细胞坏死中心环节—“细胞焦亡”有双向调控作用。前期基因测序靶向敲低和过表达组蛋白去乙酰化酶（HDAC）2基因，自噬基因ULK1会相应上调和下调；蛋白组学发现，HDAC6抑制剂可抑制ALF动物模型肝内炎症小体相关基因Caspase-1和GSDMDc-1；同时，HDAC2及HDAC6抑制剂均对ALF有治疗作用。但HDACs如何通过自噬-NLRP3炎症小体轴调控ALF细胞焦亡尚不清楚。基于此，我们提出假说：HDAC2可负向调控ULK1基因，HDAC6正向调控炎症小体相关的Caspase-1蛋白和GSDMDc-1蛋白，通过抑制HDAC2及HDAC6分子则可分别促进自噬和抑制炎症小体通路，进而抑制肝衰竭过程中的细胞焦亡过程。本项目从细胞、动物及临床实验三个层面进行，应用LPS/D-gal处理肝细胞株和大鼠，予HDACs抑制剂、shRNA、慢病毒及焦亡抑制剂干预，明确了组蛋白和该轴中关键分子的变化，并在临床中验证该变化。.本项目研究取得了一系列有科学价值的成果：①M1型巨噬细胞焦亡在急性肝衰竭合并急性肾损伤的过程中发挥重要作用；②相比于细胞凋亡，肝细胞焦亡在细胞炎症损伤过程中更能灵敏、提前反应细胞损伤程度；③细胞外组蛋白H3通过NOD2和VSIG4/NLRP3诱导的细胞焦亡在脓毒症发病过程中产生重要作用；④HDAC6抑制剂ACY1215通过调节ATM/F-actin信号通路抑制急性肝衰竭过程中NLRP3炎症小体的激活；⑤HDAC2通过K68乙酰化位点调控ULK1介导的急性肝衰竭肝细胞焦亡途径；⑥慢性乙型肝炎患者肝脏病理炎症程度与肝脏焦亡程度呈正相关，等。本项目通过明确HDAC2负调控自噬及HDAC6正调控炎症小体活化，串联抑制细胞焦亡，为寻找ALF治疗方案提供科学依据。