Rogers Christopher Q, Ajmo Joanne M, You Min
Department of Molecular Pharmacology and Physiology, University of South Florida Health Sciences Center,Tampa, FL 33612, USA.
IUBMB Life. 2008 Dec;60(12):790-7. doi: 10.1002/iub.124.
Worldwide, one of the most prevalent forms of chronic disease is alcoholic fatty liver, which may progress to more severe forms of liver injury including steatohepatitis, fibrosis, and cirrhosis. The molecular mechanisms by which ethanol consumption causes accumulation of hepatic lipid are multiple and complex. Chronic ethanol exposure is thought to cause enhanced hepatic lipogenesis and impaired fatty acid oxidation by inhibiting key hepatic transcriptional regulators such as AMP-activated kinase (AMPK), sirtuin 1 (SIRT1), PPAR-gamma coactivator alpha (PGC-1alpha), peroxisome proliferator-activated receptor alpha (PPARalpha), and sterol regulatory element-binding protein 1 (SREBP-1). Adiponectin is an adipose-derived hormone with a variety of beneficial biological functions. Increasing evidence suggests that altered adiponectin production in adipose tissue and impaired expression of hepatic adiponectin receptors (AdipoRs) are associated with the development of alcoholic liver steatosis in several rodent models. More importantly, studies have demonstrated a protective role of adiponectin against alcoholic liver steatosis. The hepato-protective effect of adiponectin is largely mediated by the coordination of multiple signaling pathways in the liver, leading to enhanced fat oxidation, reduced lipid synthesis and prevention of hepatic steatosis. This review begins with an assessment of the current understanding of the role of adiponectin and its receptors in the regulation of lipid homeostasis in liver, with emphasis on their relationship to the development of alcoholic liver steatosis. Following sections will review hepatic signaling molecules involved in the protective actions of adiponectin against alcoholic fatty liver and summarize the current knowledge of regulatory mechanisms of adiponectin expression and secretion in response to chronic ethanol exposure. We will conclude with a discussion of potential strategies for treating human alcoholic fatty liver disease (AFLD), including nutritional and pharmacological modulation of adiponectin and its receptors.
在全球范围内,慢性疾病最普遍的形式之一是酒精性脂肪肝,它可能会发展为更严重的肝损伤形式,包括脂肪性肝炎、肝纤维化和肝硬化。乙醇摄入导致肝脏脂质积累的分子机制是多方面且复杂的。长期乙醇暴露被认为会通过抑制关键的肝脏转录调节因子,如腺苷酸活化蛋白激酶(AMPK)、沉默信息调节因子1(SIRT1)、过氧化物酶体增殖物激活受体γ辅激活因子α(PGC-1α)、过氧化物酶体增殖物激活受体α(PPARα)和固醇调节元件结合蛋白1(SREBP-1),从而增强肝脏脂肪生成并损害脂肪酸氧化。脂联素是一种源自脂肪组织的激素,具有多种有益的生物学功能。越来越多的证据表明,在几种啮齿动物模型中,脂肪组织中脂联素产生的改变以及肝脏脂联素受体(AdipoRs)表达受损与酒精性肝脂肪变性的发展有关。更重要的是,研究已经证明脂联素对酒精性肝脂肪变性具有保护作用。脂联素的肝脏保护作用在很大程度上是通过肝脏中多种信号通路的协同作用介导的,导致脂肪氧化增强、脂质合成减少以及预防肝脏脂肪变性。本综述首先评估目前对脂联素及其受体在肝脏脂质稳态调节中的作用的理解,重点关注它们与酒精性肝脂肪变性发展的关系。接下来的部分将综述参与脂联素对酒精性脂肪肝保护作用的肝脏信号分子,并总结目前关于脂联素表达和分泌对长期乙醇暴露反应的调节机制的知识。我们将以讨论治疗人类酒精性脂肪肝病(AFLD)的潜在策略作为结尾,包括对脂联素及其受体的营养和药理学调节。