NLRP3炎症小体通过溶酶体/cathepsin通路介导乙型肝炎合并非酒精性脂肪肝损伤的机制研究

Chronic hepatitis B (CHB) and non-alcoholic fatty liver disease (NAFLD) are two commonest liver diseases in China, with considerably high rate of comorbidity. However, how CHB and NAFLD interact and manifest themselves clinically among patients from different regions of the country have not been well understood. In our preliminary study on CHB patients comorbid with NAFLD, the hepatic lysosome-cathepsin-NLRP3 pathways were found to be both activated. To characterize the epidemiological and pathological features of CHB-NAFLD comorbidity, this present investigation sets out by to study patients from the Shenzhen region and a mouse model for this condition. Based on clinical sample and corresponding animal tissues of CHB-NAFLD comorbidity, we will examine gene expression changes in lysosomal proteins, cathepsin B/D and NLRP3 inflammasome, thereby clarifying the signaling mechanisms underlying cellular injury. In addtion, by constructing a virus-induced CHB-NAFLD comorbidity model for knockdown of specific proteins, or using the NLRP3-specific inhibitor MCC950, we will attempt to confirm whether the above-mentioned pathways, particularly that of NLRP3 inflammasome, could be potential drug targets for treament of CHB-NAFLD comorbidity. Through studying the epidemiological and pathological features, and interactions of CHB-NAFLD comorbidity, it is hoped that we can elucidate the disease mechanisms and identify therapeutic targets, thereby providing a theoretical basis for basic research and therapeutic intervention for this diseased condition and exploring useful therapeutic agents for clinical intervention.

慢性乙型肝炎（CHB）和非酒精性脂肪性肝病（NAFLD）是我国最常见的肝脏疾病，且临床上CHB患者中合并发生NAFLD的比例较高。但我国不同地区两者合并发生的临床特征以及疾病相互影响的确切病理机制仍有待阐明。本研究组前期发现在CHB合并NAFLD患者中，肝脏内溶酶体-cathepsin-NLRP3炎症小体通路被协同激活。本项目拟以深圳地区CHB合并NAFLD临床患者及对应小鼠模型为对象，首先分析该地区该疾病的流行病学特征，然后在临床和动物模型中研究该通路与肝细胞协同损伤之间的关系，最后，通过构建肝脏特异基因敲低的小鼠模型，或使用NLRP3特异抑制剂MCC950，确认上述通路是否可以作为治疗CHB合并NAFLD的潜在靶点。本研究有望揭示CHB合并NAFLD的新流行病学特征、相互影响的病理新机制和治疗新靶点，不仅为这些疾病的基础研究和临床治疗提供新的理论基础，而且为临床治疗提供新的候选药物。

慢性乙型肝炎(CHB)和非酒精性脂肪性肝病(NAFLD)/非酒精性脂肪性肝炎(NASH)是世界上最常见的肝脏疾病，临床上CHB患者合并发生NAFLD/NASH的态势仍在不断升高，但其潜在的病理机制和相互关系尚不清楚。CHB 和 NAFLD/NASH合并存在是否会协同 HBV 影响肝病的进程或结局、两者之间怎样相互影响，目前尚有诸多争议。炎症小体在肝脏疾病中的参与机制受到了较广泛的关注，但是在合并疾病中的研究很少；研究与CHB 合并 NAFLD/NASH 患者相关的肝脏炎症分子机制，有助于理解两种疾病合并发生过程中的病理生理状态，为临床CHB 合并 NAFLD/NASH患者更好地早期发现、病情评估、治疗策略等提供参考。本项目通过收集深圳地区CHB 合并 NAFLD 患者的临床样本，围绕肝病变-溶酶体/cathepsin-NLRP3炎症小体参与调控CHB 合并 NAFLD/NASH疾病的机制进行研究，以期解析这些疾病发生发展过程中关键蛋白的调控机制。.本项目的研究成果明确了深圳地区CHB合并NAFLD患者的流行病学特征和风险因素，发现ALT、AST、是否高血糖和HBV-DNA拷贝数与CHB患者有无合并NAFLD有显著相关性；进一步阐明CHB合并NAFLD对疾病相互进程以及治疗效果的影响，CHB合并NAFLD并不加重患者肝脏炎症程度，但是合并NAFLD降低了CHB患者的抗病毒治疗效果。我们揭示了溶酶体-cathepsin-NLRP3炎症小体通路在CHB合并NAFLD/NASH发病过程中的新机制，通过敲低小鼠肝脏中NLRP3基因的表达，能够明显降低HBV/NASH小鼠的病毒活性，显著改善HBV/NASH小鼠的肥胖、胰岛素抵抗和肝损伤等症状。同时探讨NLRP3炎症小体作为治疗CHB合并NAFLD潜在靶点的可行性，应用小分子抑制剂MCC950明显改善了肝脏组织学的改变。这些研究成果为CHB合并NAFLD/NASH发病机制的研究、新药的开发与治疗等提供理论依据和新思路。项目取得的重要成果如下：（1）项目组发表有基金号标注的论文15篇，其中SCI论文5篇；（2）申请专利1项。