LIPID PEROXIDATION\CELL SIGNALING-CC14-INDUCED FIBROSIS

描述：(改编自《调查者摘要》)： 本项目旨在确立乙醛产品的机械作用(S) 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。越来越清楚的是，这些 化学反应的醛表现出一系列的细胞效应 从酶抑制到提高特定基因的转录 在胶原蛋白合成和纤维化方面。调查者的工作假说 预测AP-1和NFkappaB是影响ITO细胞的关键系统 4-HNE和丙二醛，其结果(S)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 假说将在三个特定的目标中系统地评估，使用肝脏 进展过程中分离的大鼠非实质细胞和实质细胞 CCl4诱导的肝硬变。在具体目标1中，PI将建立 4-HNE和丙二醛作为AP-1调控元件的促纤维化作用 涉及α1-(1)前胶原的转录失调， 金属蛋白酶-1和组织金属蛋白酶抑制因子-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NFkB信号通路在时间过程中的变化 CC14诱导的肝纤维化，并确定如何调节这一途径 在Ito细胞中影响肝细胞的细胞死亡。在具体目标3中，实验 利用肝细胞、枯否细胞和伊藤细胞的共培养将进行 鉴定4-HNE或丙二醛的细胞来源并确定其能力 这些醛扩散到相邻的细胞中并对其产生影响。这些因素的影响 Ito电池上的醛将根据与Kupffer的相互作用进行评估 细胞衍生细胞因子肿瘤坏死因子α和转化生长因子β，目的是识别 潜在影响的细胞介质的细胞来源和靶点 细胞死亡的途径。 这些研究将极大地提高对机械作用的理解(S) 化学性肝损伤中脂质过氧化的醛类产物 和纤维化症。识别新的细胞靶点和特定的机制 可以为开发有效的治疗方法提供信息 改善肝炎性和肝炎性疾病特定成分的干预措施 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.