ITO CELL ACTIVATION BY HEPATOCYTES IN ALCOHOLIC FIBROSIS

酒精性纤维化中肝细胞对 ITO 细胞的激活

• 批准号: 6497146
• 负责人: JOHN F REICHARD
• 金额: $ 2.62万
• 依托单位: UNIVERSITY OF COLORADO DENVER
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-02-01 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/6497146
• 关键词: biological signal transduction; cell cell interaction; cell differentiation; cell line; cell type; cytochrome P450; cytokine; cytokine receptors; ethanol; extracellular matrix; fibrosis; gene expression; laboratory rat; lipid peroxides; liver cells; oxidative stress; peroxidation; receptor expression

Myofibroblastic transdifferentiation of quiescent Ito cells is characteristic of alcohol-induced fibrosis and is responsible for increased production of extracellular matrix; however, factors initiating Ito cell activation are unknown. The overall goal of this proposal is to delineate the mechanism(s) by which CYP2E1- expressing hepatocytes initiate transdifferentiation of quiescent Ito cells to myofibroblasts. The first Specific Aim is designed to determine the role of CYP2E1-mediated lipid peroxidation in triggering cytokine release from stressed hepatocytes. This will be accomplished by producing a non-transformed hepatocyte cell line that stably over-expresses CYP2E1. Oxidative stress will be assessed by measuring alcohol induced glutathione depletion and unsaturated aldehyde liberation. Cytokines produced in response to oxidative stress will be identified. In situ hybridization will demonstrate expression of identified cytokine genes in ethanol-fed rats. The second aim is to characterize the activation of quiescent Ito cells by CYP2E1-expressing hepatocytes, and to investigate the contribution of Kupffer cells to hepatocyte-mediated Ito cell activation. Transdifferentiation will be investigated utilizing a culture system that does not produce Ito cell culture-activation. The third aim will describe the cytokine dependent signal transduction pathways which stimulate quiescent Ito cells transformation to the myofibroblast phenotype. The precise temporal relationship between initiation of Ito cell transdifferentiation, transcription factor activation and cytokine signal transduction pathway activation will be explored. The in vivo relationship between cytokine production, Ito cell activation and cytokine receptor expression will be described.

静止的Ito细胞的肌成纤维细胞转分化是酒精诱导的纤维化的特征，并负责增加细胞外基质的产生;然而，启动Ito细胞活化的因素是未知的。 本提案的总体目标是描述表达CYP 2 E1的肝细胞启动静止Ito细胞转分化为肌成纤维细胞的机制。 第一个特定目的旨在确定CYP 2 E1介导的脂质过氧化在触发应激肝细胞释放细胞因子中的作用。 这将通过生产稳定过表达CYP 2 E1的非转化肝细胞系来实现。 将通过测量酒精诱导的谷胱甘肽消耗和不饱和醛释放来评估氧化应激。 将鉴定响应于氧化应激产生的细胞因子。 原位杂交将证明在乙醇喂养的大鼠中鉴定的细胞因子基因的表达。 第二个目的是表征表达CYP 2 E1的肝细胞对静止Ito细胞的激活，并研究枯否细胞对肝细胞介导的Ito细胞激活的贡献。 将使用不产生Ito细胞培养活化的培养系统研究转分化。 第三个目标将描述细胞因子依赖的信号转导途径，刺激静止的Ito细胞转化为肌成纤维细胞表型。 Ito细胞转分化启动、转录因子激活和细胞因子信号转导通路激活之间的精确时间关系将被探索。 将描述细胞因子产生、Ito细胞活化和细胞因子受体表达之间的体内关系。