丹参酮IIA清除4-羟基壬烯醛治疗酒精性肝病的调控机制研究

Alcohol liver disease(ALD) remains a leading cause of death from liver diseases in the world. However, the safe and effective therapies for ALD in humans remain elusive, mainly due to the lack of our understanding on its detailed pathogenesis. Salvia, As a kind of traditional Chinese medicine, has unique advantages in the prevention and treatment of ALD, but the mechanism is not very clear, limiting its application in clinical treatment. Therefore, the research aiming to understand the cellular/molecular mechanisms of salvia in ALD treatment, is urgently needed. Emerging evidence suggests that oxidative stress play pivotal roles in the onset and progression of ALD. Chronic alcohol consumption produces a state of sustained chronic oxidative stress, eventually leading to excessive accumulation of lipid peroxides, the ultimate mediator of toxicity induced by oxidative stress. Of lipid peroxidates, 4-Hydroxynonenal(4-HNE) is the most abundant and reactive aldehydic products. We have obtained preliminary data showing that exposure to exogenous 4-HNE sensitized hepatocytes to TNF-α induced cytotoxicity, potentially via interfering with TNF-mediated NF-κ B signaling pathway. In our preliminary studies, we found that Tanshinone IIA, as the main monomer Salvia, can inhibit the liver cell death by removing excess 4-HNE through activating the PPAR-a level, but the mechanism is unclear. These data altogether support the following hypothesis: Tanshinone IIA reduces the 4-HNE level in hepatocyte by up-regulating PPAR-α expression, inhibiting 4-HNE generation or facilitating 4-HNE degradation, and then activating NF-κB anti-apoptotic pathway or blocking JNK apoptotic pathway, which is one of the mechanisms of Salvia in ALD treatment. In this proposal, we will systemically examine the role of Tanshinone IIA in protect hepatocytes by reducing 4-HNE level cell and attempt to delineate the underlying mechanisms involved in activating PPAR-a, clearing 4-HNE and regulating the cell signal pathway. In this proposal, we will employ multiple state-of-the-arts biomedical technologies, including shRNA transfection, immunoprecipitation, gene transfection, to name a few, to investigate the mechanisms underlying the effects of Tanshinone IIA in hepatocyte protection. Our ultimate goal is to provide new strategies for the clinical treatment and the development of novel therapeutic drugs based on Tanshinone IIA in treatment of ALD.

酒精性肝病（ALD）危害严重，且临床尚无有效治疗手段。活血化瘀中药丹参防治ALD具有独特优势，但作用机理不甚明确，限制了在临床治疗上的应用。课题组前期研究发现，4-羟基壬烯醛（4-HNE）是肝脏长期暴露于酒精后诱发氧化应激而产生的一种致病因子，中药丹参的主要单体丹参酮ⅡA可以上调肝细胞PPAR-α蛋白表达，从而降低4-HNE水平，抑制肝细胞死亡，然而机制尚不清楚。根据前期研究基础，本课题提出了"丹参酮ⅡA通过激活PPAR-α，抑制4-HNE的生成或促进4-HNE的降解，从而激活NF-κB抗凋亡通路或抑制JNK促凋亡通路，减轻酒精代谢产物4-HNE对肝脏的损伤是丹参治疗ALD的作用机制之一"的假说。拟从体内、体外两方面，利用RNA干扰等技术从系统学和细胞信号调控水平明确丹参酮ⅡA清除4-HNE抑制肝细胞死亡的作用，并阐明其机制及靶点，为以丹参酮ⅡA为主的治疗ALD的新型药物研发提供新的思路。

酒精性肝病（ALD）危害严重，且临床尚无有效治疗手段。活血化瘀中药丹参防治 ALD 具有独特优势，但作用机理不甚明确，限制了在临床治疗上的应用。课题组前期研究发现，4-羟基壬烯醛（4-HNE）是肝脏长期暴露于酒精后诱发氧化应激而产生的一种致病因子，中药丹参的主要单体丹参酮ⅡA 可以上调肝细胞 PPAR-α 蛋白表达，从而降低 4-HNE水平，抑制肝细胞死亡，然而机制尚不清楚。根据前期研究基础，本课题验证了“丹参酮ⅡA 通过激活 PPAR-α ，抑制 4-HNE 的生成或促进 4-HNE 的降解，从而激活 NF-κ B 抗凋亡通路或抑制 JNK 促凋亡通路，减轻酒精代谢产物 4-HNE 对肝脏的损伤是丹参治疗 ALD 的作用机制之一”的。本课题从体内和体外两方面实验，利用 RNA 干扰等技术从系统学和细胞信号调控水平明确了丹参酮ⅡA 清除 4-HNE 抑制肝细胞死亡的作用，并阐明其机制及靶点，为以丹参酮ⅡA为主的治疗 ALD 的新型药物研发提供了新的思路。