METHODS: The combination between Fructose-palmitate-cholesterol diet (FPC) and Streptozotocin (STZ) (FPC+STZ) was used to construct diabetic NASH mouse model. The in vivo effects of silencing acid-sensitive Ion Channel 1a (ASIC1a) were examined with an adeno-associated virus 9 (AAV9) carrying ASIC1a short hairpin RNA (shRNA) in FPC+STZ model.
RESULTS: The mice fed with FPC for 12 weeks had insulin resistance, hyperinsulinemia, lipid accumulation, and increased hepatic levels of inflammatory factors. However, it still did not develop remarkable liver fibrosis. Most interestingly, noticeable fibrotic scars were observed in the liver of mice from FPC+STZ group. Furthermore, insulin therapy significantly ameliorated FPC+STZ-induced NASH-related liver fibrosis, indicating that hyperglycemia is of great significance in NASH development and progression. Importantly, ASIC1a was found to be involved in the pathogenesis of diabetic NASH as demonstrated that silencing ASIC1a in HSCs significantly ameliorated FPC+STZ-induced NASH fibrosis. Mechanistically, ASIC1a interacted with Poly Adp-adenosine ribose polymerase (PARP1) to promote HSC activation by inducing autophagy.
CONCLUSIONS: A FPC diet combined with an injection of STZ induces a diabetic NASH mouse model in a shorter period. Targeting ASIC1a may provide a novel therapeutic target for the treatment of diabetic NASH.
方法:采用果糖-棕榈酸-胆固醇饮食(FPC)和链脲佐菌素(STZ)(FPC+STZ)联合构建糖尿病NASH小鼠模型。在FPCSTZ模型中,使用携带ASIC1a短发夹RNA(shRNA)的腺相关病毒9(AAV9)检查了沉默酸敏感性离子通道1a(ASIC1a)的体内作用。
结果:用FPC喂养12周的小鼠出现胰岛素抵抗,高胰岛素血症,脂质积累,肝脏炎症因子水平升高。然而,它仍然没有出现明显的肝纤维化。最有趣的是,在来自FPC+STZ组的小鼠的肝脏中观察到明显的纤维化疤痕。此外,胰岛素治疗显著改善FPC+STZ诱导的NASH相关肝纤维化,提示高血糖在NASH发生发展中具有重要意义。重要的是,发现ASIC1a参与糖尿病NASH的发病机理,如证明HSC中沉默ASIC1a显著改善FPC+STZ诱导的NASH纤维化。机械上,ASIC1a与多聚腺苷核糖聚合酶(PARP1)相互作用,通过诱导自噬促进HSC活化。
结论:FPC饮食结合注射STZ在较短时间内诱导糖尿病NASH小鼠模型。靶向ASIC1a可能为糖尿病NASH的治疗提供新的治疗靶点。