莪术醇调控CCF抗酒精性脂肪肝中肝细胞衰老的作用机制

The current researches of alcoholic fatty liver disease (AFLD) are mainly focus on inhibition of lipid accumulation and induction of hepatocyte apoptosis. Senescence of hepatocyte and the related molecular mechanisms are rarely investigated. Our previous studies showed that curcumol could potently suppress alcohol-induced hepatocyte senescence and the formation of cytoplasmic chromatin fragments (CCF). We herein creationally put forward that curcumol has effects on AFLD associated with inhibition of cellular senescence by regulating the formation of CCF. To test these hypotheses, we first use the in vivo and in vitro AFLD model to investigate the correlation between the regulation of senescence associated secretory phenotype (SASP) cytokine secretion and senescence of hepatocyte under curcumol treatment. Then we use the plasmid transfection and gene silencing technologies to further study the molecular mechanism of repression of hepatocyte senescence by which curcumol regulates SASP cytokine secretion through CCF-cGAS-STING. Finally, Based on the establishment of the critical role of CCF-cGAS-STING in curcumol intervention of senescence of hepatocyte, we attempt to elucidate whether this effect is associated with LC3-lamin B1 interaction. Through these studies, we can interpret the actions of curcumol on hepatocyte senescence and elucidate the underlying molecular mechanisms. These studies provide basis for developing curcumol as promising anti-AFLD agent for clinical application.

酒精性脂肪肝（AFLD）目前国内外研究多聚焦于抑制肝细胞脂质堆积和细胞凋亡，忽略了肝细胞衰老及其相关机制在其中发挥的重要作用。我们前期工作初步表明，莪术醇（Curcumol）可有效抑制酒精诱导的肝细胞衰老及胞质染色质碎片（CCF）的形成。本项目创新性的提出Curcumol可能通过调控CCF的形成抑制肝细胞衰老进而具有抗AFLD的作用。为此，本研究拟利用酒精建立体内外AFLD模型，首先明确Curcumol调控衰老相关分泌表型（SASP）细胞因子分泌与肝细胞衰老相关；然后利用质粒转染、基因沉默等技术研究Curcumol通过CCF-cGAS-STING调控SASP细胞因子分泌继而抑制肝细胞衰老的分子机制，并明确CCF的形成是否依赖于LC3-lamin B1相互作用。以此从新的视角阐明Curcumol具有抗AFLD的作用及分子机制，预期研究成果有望为Curcumol防治AFLD提供新策略和新靶点。

文献调研显示肝细胞衰老在酒精性脂肪肝（AFLD）发展过程中起着重要作用，这表明抑制肝细胞衰老可能是防治AFLD的潜在策略。本课题主要研究莪术醇对AFLD中肝细胞衰老的影响及其调控机制。结果表明，莪术醇能够改善Lieber DeCarli酒精液体饲料喂养的小鼠肝脏以及乙醇处理的LO2细胞中的脂质沉积和损伤。体内和体外研究均表明，莪术醇可有效缓解乙醇诱导的肝细胞衰老，主要表现为衰老相关-β-半乳糖苷酶（SA-β-gal）活性降低、衰老相关标志物p16和p21表达下调以及端粒/端粒酶系统功能紊乱。进一步研究显示莪术醇显著抑制了乙醇诱导的细胞核外染色质片段（CCF）的形成和随后的cGAS-STING的激活，导致衰老相关分泌表型（SASP）因子分泌的显著减少。而莪术醇对CCF形成的抑制可能与阻断LC3B与Lamin B1的相互作用并维持核膜完整性相关。总之，这些结果表明莪术醇能够通过抑制肝细胞衰老来改善AFLD，这可能归因于其阻断LC3B和Lamin B1的相互作用以及随后CCF-cGAS-STING通路的失活。这些结果表明莪术醇在治疗AFLD中有很好的应用前景。