E2F/TRAIL介导增殖和凋亡失衡在HBV相关慢加急性肝衰竭衰竭中的作用研究

In China, HBV-infected acute-on-chronic liver failure(ACLF) cases account for more than 80% of ACLF cases owing to a high incidence of chronic HBV infection.The lack of effective therapeutic options for the majority of ACLF patients results in a dramatic deterioration with a subsequently poor prognosis, leading to a high mortality rate of the disease. Hepatocyte apoptosis is considered to be a main reason contributed to liver damage. Virus-specific CD8+ T-cell responses through Fas/FasL and NK cells responses through NKG2D/NKG2DL pathway play important roles in acute liver failure.But the detailed mechenism in HBV-related ACLF is still unclear. Basis on our previous studies and by reviwing the references, we hypothesed that proliferation inhibition mediated by E2F transcription factors and apoptosis induced by TRAIL may play roles in HBV-related ACLF.This study is designed to determine: ① whether E2F/TRAIL are involved in HBV-related acute-on-chronic liver failure by using blood and liver biosy from ACLF patients.②wheher hepatocytes proliferation and apoptosis are affected by HBV infection or HBV gene transduction.③ how TRAIL apoptotic role in hepatocytes is modulated by HBV gene products by using HBV and HBV genes infected HepRG cell.

在中国，HBV 感染相关的慢加急性肝衰竭（acute-on-chronic liver failure，ACLF）患者约占肝衰竭患者总数的80%。乙型肝炎相关ACLF预后差，病死率高，与肝细胞过度凋亡密切相关，但其发病机制仍不清楚。通过国内外文献复习和前期工作基础，我们推测HBV感染增强TRAIL诱导凋亡敏感性并介导肝细胞的过度凋亡，同时E2F介导的肝细胞增殖能力受抑制，这可能是HBV相关慢加急性肝衰竭发生的一个新机制。为证实这一假说，我们将采用分子生物学、细胞免疫组化和流式细胞仪等技术，从整体水平研究肝衰竭病人外周血和肝组织中TRAIL/E2F的表达情况；并进一步从细胞层次，观察乙型肝炎病毒感染对TRAIL表达增加或活化的影响，及其对肝细胞凋亡/增殖抑制的作用及相关机制。本课题将从新的视觉阐明HBV相关ACLF 发生的分子机制，并为ACLF的防治提供新的靶点。

在中国，HBV 感染相关的慢加急性肝衰竭（acute-on-chronic liver failure，ACLF）患者约占肝衰竭患者总数的80%。乙型肝炎相关ACLF预后差，病死率高，目前仍无特异性治疗措施。研究和阐明HBV相关ACLF的发生机制，有助于为其有效防治提供新靶点。细胞增殖和凋亡动态平衡是维持肝细胞功能的两个重要途径，本研究拟从肝细胞凋亡与增殖的失衡来研究肝衰竭发生的可能机制。结果显示：1. HBV相关慢加急性肝衰竭 (HBV-ACLF) 病人外周血NK细胞高度活化并高表达细胞毒性配体TRAIL，HBV-ACLF患者血清炎性因子水平升高，与NK细胞表面TRAIL和CD69受体表达显著相关。2. HBV感染增加肝细胞表面TRAIL受体DR4和DR5表达，来自HBV-ACLF患者的NK细胞通过TRAIL介导肝细胞凋亡。3. HBV-ACLF患者肝脏免疫组化显示E2F1表达减低而E2F4表达增加，提示肝细胞增殖能力降低。4. NK细胞表面激活的TRAIL与肝细胞表面TRAIL受体结合，可通过激活Caspase途径引起肝细胞凋亡。本研究提示HBV 相关慢加急性肝衰竭病人TRAIL/TRAIL 受体激活，肝细胞凋亡增加，而肝细胞增殖能力降低，从新的视觉阐明其发生机制，为慢加急性肝衰竭的防治提供新思路和新靶点。