NFkB-mediated collagen regulation by SAMe in HSCs

HSC 中 SAMe 介导的 NFkB 介导的胶原蛋白调节

• 批准号: 7009644
• 负责人: LAURA W SCHRUM
• 金额: $ 20.38万
• 依托单位: UNIVERSITY OF NORTH CAROLINA CHARLOTTE
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-02-01 至 2009-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7009644
• 关键词: I kappa B beta; S adenosylmethionine; acetaldehyde; collagen; ethanol; fibrosis; gene induction /repression; intravital microscopy; laboratory rat; liver cells; liver disorder; liver metabolism; mitogen activated protein kinase; nuclear factor kappa beta; protein biosynthesis; transfection; western blottings

DESCRIPTION (provided by applicant): Hepatic fibrosis is characterized by an increase in type I collagen deposition which alters the normal architecture of the liver leading to liver dysfunction. Many etiologies have been associated with hepatic fibrosis with chronic alcohol consumption being the leading cause of liver fibrosis in the United States. The hepatic stellate cell (HSC) is the primary cell type in the liver responsible for excess synthesis of collagen during fibrosis. Following exposure to alcohol, the HSC undergoes a transformation from a quiescent, vitamin A storing cell to that of an activated, collagen producing myofibroblast-like cell. The effects of alcohol on the activation of HSCs have been implicated to alcohol-induced oxidative stress. The metabolism of ethanol leads to the production of free radicals that have been linked to the development of alcohol-induced liver injury. Thus, diminishing oxidative damage by the use of antioxidants may serve as successful therapeutic treatments for liver diseases caused by numerous agents including alcohol. S-adenosyI-L-methionine (SAMe), the precursor of glutathione, has potential usefulness as an antioxidant. SAMe has been shown to improve hepatic fibrosis; however, the molecular mechanisms of SAMe in liver fibrosis is not understood. The role of SAMe as an antioxidant implicates the redox-sensitive transcription factor nuclear factor kappa B (NFkB) and the pathway(s) that regulates its activity as being a key player which may mediate the antioxidant effects of SAMe. SAMe's attenuation of liver fibrosis may occur through the regulation of certain transcription factors that modulate collagen expression in the HSC. Thus, this proposal hypothesizes that the antioxidant SAMe inhibits alcohol-induced collagen expression by modulating NFkB activity in the HSC. The results of these studies will aid in the development of novel therapeutics aimed at preventing the progression of oxidative-induced hepatic fibrosis.

描述（由申请人提供）：肝纤维化的特征是 I 型胶原沉积增加，这改变了肝脏的正常结构，导致肝功能障碍。许多病因与肝纤维化有关，在美国，长期饮酒是肝纤维化的主要原因。肝星状细胞（HSC）是肝脏中负责纤维化过程中胶原蛋白过度合成的主要细胞类型。接触酒精后，HSC 会从静止的维生素 A 储存细胞转变为活化的、产生胶原蛋白的肌成纤维细胞样细胞。酒精对 HSC 激活的影响与酒精诱导的氧化应激有关。乙醇的代谢会导致自由基的产生，自由基与酒精引起的肝损伤的发生有关。因此，通过使用抗氧化剂减少氧化损伤可以成功治疗由包括酒精在内的多种物质引起的肝脏疾病。 S-腺苷-L-甲硫氨酸 (SAMe) 是谷胱甘肽的前体，具有作为抗氧化剂的潜在用途。 SAMe 已被证明可以改善肝纤维化；然而，SAMe 在肝纤维化中的分子机制尚不清楚。 SAMe 作为抗氧化剂的作用涉及氧化还原敏感转录因子核因子 kappa B (NFkB) 和调节其活性的途径，作为介导 SAMe 抗氧化作用的关键参与者。 SAMe 可能通过调节 HSC 中胶原蛋白表达的某些转录因子来减轻肝纤维化。因此，该提议假设抗氧化剂 SAMe 通过调节 HSC 中的 NFkB 活性来抑制酒精诱导的胶原蛋白表达。这些研究的结果将有助于开发旨在预防氧化诱导的肝纤维化进展的新疗法。