基于PARP1/SIRT1信号通路介导的脂质代谢及线粒体氧化损伤探究鼠尾草酸抗酒精性肝病的作用机制

Lipid metabolism disorder and mitochondrial oxidative damage play a vital role in the pathological mechanisms of alcoholic liver disease (ALD). poly ADP-ribose polymerase-1 (PARP1 ) has been reported to participate in the regulation of lipid metabolism and mitochondrial function, and is correlated with ALD, however, the related molecular mechanisms in ALD remain unknown. Carnosic acid (CA) is extracted from Rosmarinus officinalls L and has been reported to protect against ALD by affecting lipid metabolism via the SIRT1-ChREBP pathway and by affecting oxidative stress via the SIRT1-p66shc pathway. The preliminary experiments showed that CA significantly decreased PARP1 in ALD, which was negatively correlated with the expression of SIRT1. Furthermore, the knockout of PARP1 in vitro significantly increased SIRT1 expression, leading to the alleviation of the ethanol-induced lipid accumulation and mitochondrial oxidative damage. In the proposal, a variety of advanced molecular biology methods will be used for confirming the vital role of PARP1/SIRT1 signal pathway in regulating lipid metabolism and mitochondrial oxidative damage in the protection against ALD, and revealed the molecular mechanism that CA regulated SIRT1-ChREBP and SIRT1-p66shc pathway via PARP1 in ALD. The proposal contributes to the development and clinical application of rosemary extract, and represents an attractive pharmacological target for the development of CA to arrest ALD.

脂质代谢紊乱及线粒体氧化损伤是酒精性肝病（ALD）发病机制的重要因素。1型多聚ADP核糖合成酶（PARP1）参与脂质代谢及线粒体功能调节，且与ALD密切相关，但具体机制不清。鼠尾草酸（CA）为中药迷迭香的提取物，我们既往研究表明其通过激活SIRT1，抑制ChREBP、p66shc介导的脂质堆积、线粒体氧化损伤，从而减轻ALD。近期发现：在ALD中，CA能显著抑制PARP1的高表达，与SIRT1低表达呈负相关；体外干扰PARP1后，SIRT1表达升高，脂质堆积、线粒体损伤减轻。本项目拟结合动物、离体细胞模型，阐明PARP1/SIRT1通路调控脂质代谢及线粒体氧化损伤在ALD中的重要作用以及揭示CA通过作用于PARP1，激活SIRT1-ChREBP和SIRT1-p66shc通路减轻ALD的分子机制。本研究有助于迷迭香提取物的临床应用，为防治ALD提供科学依据和治疗靶点。

脂质代谢紊乱及线粒体氧化损伤是酒精性肝病（ALD）发病机制的重要因素。鼠尾草酸（CA）为中药迷迭香的提取物，其对大鼠酒精性肝损伤具有明显的保护作用。该保护作用与1型多聚ADP核糖合成酶（PARP1）的抑制、SIRT1的诱导进而调节碳水化合物反应原件结合蛋白（ChREBP）和衔接蛋白p66shc分别介导的脂质代谢及肝细胞线粒体损伤有关。本研究利用对慢性酒精性肝损伤的动物模型及AML12细胞模型，采用Westernblot、RNAi等分子生物学方法，明确鼠尾草酸在酒精液体饲料造模的大鼠体内抗慢性酒精性肝损伤的药效评价；探讨大鼠慢性酒精性肝损伤模型PARP1变化与SIRT1、p66shc等表达的相关性及CA的干预作用；阐明PARP1/SIRT1/ChREBP及PARP1/SIRT1/p66shc在慢性酒精性肝损伤中的调控作用及鼠尾草酸对其的保护机制。.主要研究成果：CA在体内体外对慢性酒精性肝损伤具有保护作用，其保护作用与抑制PARP1有关，且具有时间与剂量的依赖性；通过RNA干扰技术，证明CA可通过抑制PARP1，激活SIRT1/ChREBP及SIRT1/p66shc信号通路；首次证实CA通过抑制PARP1, 激活SIRT1/ChREBP及SIRT1/p66shc信号通路减轻脂质堆积及线粒体氧化损伤，从而减轻慢性酒精性肝损伤。.本项目首次发现天然产物CA对PARP1的抑制作用，首次阐明PARP1/SIRT1通路调控脂质代谢及线粒体氧化损伤在ALD中的重要作用及揭示CA通过作用PARP1，激活SIRT1/ChREBP和SIRT1/p66shc通路减轻ALD的分子机制。本研究有助于迷迭香提取物的临床应用，为开发治疗该疾病的新药提供有希望的药理学靶点。