LIPID PEROXIDATION\CELL SIGNALING-CC14-INDUCED FIBROSIS

描述：（改编自研究者摘要）： 本项目旨在确定以下产品的机械作用： 脂质过氧化（4-羟基壬烯醛[4-HNE]和丙二醛[MDA]）， 化学性肝纤维化越来越明显的是， 化学反应性醛显示出一系列细胞效应， 从酶抑制到增加特定基因的转录 胶原合成和纤维化。调查员的工作假设 预测AP-1和NF-κ B是Ito细胞中的关键系统， 4-HNE和MDA，其结果表现为胶原蛋白失衡 肝细胞死亡过程的合成/降解和失调。这 将使用肝脏在3个特定目标中对假设进行系统评价 从大鼠中分离的非实质细胞和实质细胞在进展过程中 四氯化碳诱发的肝硬化在具体目标1中，PI将建立 4-HNE和MDA作为AP-1中调节元件的纤维化潜力 涉及α 1-（1）前胶原的转录失调， 金属蛋白酶-1（MMP-1）和组织金属蛋白酶抑制剂-1（TIMP-1） 培养的伊藤细胞中的基因。为具体目标2提出的实验将 研究Ito细胞中NF κ B信号通路在时间过程中的变化 CC 14诱导的肝纤维化，并确定如何调节这一途径 影响肝细胞中的细胞死亡。在具体目标3中， 将使用肝细胞、枯否细胞和Ito细胞的共培养物进行 以鉴定4-HNE或MDA的细胞来源，并确定 这些醛扩散进入并影响相邻细胞。成效为何 将根据与Kupffer的相互作用来评价醛对Ito细胞的影响 细胞衍生的细胞因子TNF α和TGF β，目的是鉴定 细胞介质的细胞来源和靶点， 细胞死亡的途径。 这些研究将大大提高对机械作用的理解 化学性肝损伤中脂质过氧化产物的变化 和纤维化。新的细胞靶点和特定机制的鉴定 可以提供信息，导致开发有效的治疗方法， 用于改善肝脏炎症和炎症性疾病的特定组分的干预， 纤维化过程

DESCRIPTION: (Adapted from the Investigator's Abstract): The long-range goal of this project is to establish the mechanistic role(s) of aldehydic products of lipid peroxidation (4-hydroxynonenal [4-HNE] and malondialdehyde [MDA]) in chemical-induced liver fibrosis. It has become increasingly clear that these chemically reactive aldehydes display a spectrum of cellular effects ranging from enzyme inhibition to increasing transcription of specific genes involved in collagen synthesis and fibrosis. The investigator's working hypothesis predicts that AP-1 and NFkappaB are critical systems in Ito cells affected by 4-HNE and MDA the result(s) of which are manifested in an imbalance of collagen synthesis/degradation and dysregulation of hepatocyte death processes. This hypothesis will be systematically evaluated in 3 specific aims using hepatic nonparenchymal and parenchymal cells isolated form rat during the progression of CCl4-induced cirrhosis. In Specific Aim 1, the PI will establish the fibrogenic potential of 4-HNE and MDA as regulatory elements in AP-1 transcriptional dysregulation involving alpha1-(1) procollagen, metalloproteinase-1 (MMP-1) and tissue metalloproteinase inhibitor-1 (TIMP-1) genes in cultured Ito cells. Experiments proposed for Specific Aim 2 will investigate changes NFkB signaling pathways in Ito cells during the time course of CC14-induced hepatic fibrosis and determine how regulation of this pathway in Ito cells affects cell death in hepatocytes. In Specific Aim 3, experiments using co-cultures of hepatocytes, Kupffer cells and Ito cells will be performed to identify the cellular origin of 4-HNE or MDA and determine the ability of these aldehydes to diffuse into and effect adjacent cells. The effects of these aldehydes on Ito cells will be evaluated in terms of interactions with Kupffer cell-derived cytokines TNFalpha, and TGFbeta with the goal of identifying cellular sources and targets of cellular mediators that potentially influence pathways of cell death. These studies will greatly enhance the understanding of the mechanistic role(s) of aldehydic products of lipid peroxidation in chemical-induced liver injury and fibrosis. Identification of novel cellular targets and specific mechanisms could provide information leading to development of effective therapeutic interventions for ameliorating specific components of hepatic inflammatory and fibrotic processes.