背景:非酒精性脂肪性肝炎(NASH),非酒精性脂肪性肝病进展中的炎症亚型,正在成为威胁人类健康的严重负担,但迄今为止还没有批准的药物。Mononoside是源自山茱萸的天然活性物质,在我们先前的研究中已被证实在调节脂质代谢方面具有巨大的潜力。然而,其抑制NASH进展的作用和机制尚不清楚。
目的:我们的工作旨在从调节脂质吞噬的角度探讨单糖苷延缓NASH进展的作用及其调控机制。
结果:雄性C57BL/6小鼠饲喂高脂高果糖饮食16周,建立NASH小鼠模型。经过8周的高脂肪和高果糖喂养,给这些小鼠服用不同剂量的莫罗尼苷。H&E染色,ORO染色,Masson染色,RNA-seq,免疫印迹,并通过免疫荧光法测定莫诺苷延缓NASH进展的作用和分子机制。在这项研究中,我们发现莫罗尼苷能有效减轻肝脏脂质代谢紊乱和炎症反应激活,从而限制了高脂肪和高果糖饮食喂养小鼠从单纯性脂肪肝到NASH的进展。机械上,我们通过转录组测序确定了AMPK信号传导是莫诺苷阳性疗效的关键分子途径.我们的结果表明,莫诺苷通过促进AMPKα磷酸化介导的脂质吞噬和脂肪酸氧化来维持肝脂质代谢稳态并抑制NLRP3炎性体活化。在棕榈酸处理的细胞模型中观察到一致的结果。特别值得注意的是,体内和体外沉默AMPKα可逆转莫诺苷诱导的脂质吞噬通量增强和NLRP3炎性体抑制,强调AMPKα激活在莫诺苷抑制NASH进展中的关键作用。
结论:总之,本研究首次提供了强有力的证据,证明莫诺苷通过促进AMPK依赖性吸脂性和抑制NLRP3炎性体激活来抑制NASH进展,这表明莫罗尼甙有望成为开发NASH治疗药物的潜在分子实体。
BACKGROUND: Non-alcoholic steatohepatitis (NASH), the inflammatory subtype in the progression of non-alcoholic fatty liver disease, is becoming a serious burden threatening human health, but no approved medication is available to date. Mononoside is a natural active substance derived from Cornus officinalis and has been confirmed to have great potential in regulating lipid metabolism in our previous studies. However, its effect and mechanism to inhibit the progression of NASH remains unclear.
OBJECTIVE: Our work aimed to explore the action of mononoside in delaying the progression of NASH and its regulatory mechanisms from the perspective of regulating lipophagy.
RESULTS: Male C57BL/6 mice were fed with a high-fat and high-fructose diet for 16 weeks to establish a NASH mouse model. After 8 weeks of high-fat and high-fructose feeding, these mice were administrated with different doses of morroniside. H&E staining, ORO staining, Masson staining, RNA-seq, immunoblotting, and immunofluorescence were performed to determine the effects and molecular mechanisms of morroniside in delaying the progression of NASH. In this study, we found that morroniside is effective in attenuating hepatic lipid metabolism disorders and inflammatory response activation, thereby limiting the progression from simple fatty liver to NASH in high-fat and high-fructose diet-fed mice. Mechanistically, we identified AMPK signaling as the key molecular pathway for the positive efficacy of morroniside by transcriptome sequencing. Our results revealed that morroniside maintained hepatic lipid metabolism homeostasis and inhibited NLRP3 inflammasome activation by promoting
AMPKα phosphorylation-mediated lipophagy and fatty acid oxidation. Consistent results were observed in palmitic acid-treated cell models. Of particular note, silencing
AMPKα both in vivo and in vitro reversed morroniside-induced lipophagy flux enhancement and NLRP3 inflammasome inhibition, emphasizing the critical role of
AMPKα activation in the effect of morroniside in inhibiting NASH progression.
CONCLUSIONS: In summary, the present study provides strong evidence for the first time that morroniside inhibits NASH progression by promoting AMPK-dependent lipophagy and inhibiting NLRP3 inflammasome activation, suggesting that morroniside is expected to be a potential molecular entity for the development of therapeutic drugs for NASH.