HEME OXYGENASE-1 IN HEPATIC ISCHEMIA/REPERFUSION INJURY

血红素加氧酶-1 在肝缺血/再灌注损伤中的作用

• 批准号: 6631347
• 负责人: Jerzy W Kupiec-Weglinski
• 金额: $ 33.55万
• 依托单位: UNIVERSITY OF CALIFORNIA LOS ANGELES
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-04-01 至 2008-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6631347
• 关键词: Kupffer's cell; RNase protection assay; T cell receptor; apoptosis; biological signal transduction; cell cell interaction; cellular immunity; cytoprotection; enzyme activity; enzyme induction /repression; enzyme linked immunosorbent assay; genetically modified animals; heme oxygenase; hyaluronate; in situ hybridization; laboratory mouse; liver ischemia /hypoxia; liver transplantation; polymerase chain reaction; postoperative complications; receptor expression; reperfusion; terminal nick end labeling; tissue /cell culture; western blottings

DESCRIPTION (provided by applicant): lschemia/reperfusion (I/R) insult remains one of the major limitations of orthotopic liver transplantation (OLT). This proposal is built upon the insights gained from our studies on a novel approach of inducing heme oxygenase-1 (HO-1) expression in OLTs. We hypothesize that: (i) HO-I facilitates a systemic mileu, which via STAT6 pathway leads to emergence of a dominant "cytoprotectlve" type-2 T cell subset; (ii) HO-1 depresses apoptotic machinery and triggers type-2 anti-apoptotic cytoprotactive mechanisms; (iii) hyaluronic acid (HA) provides a "danger" signal to activate toll-like receptor 4 (TLR 4) complex on Kupffer cells; HO-1 - TLR 4 cross-talk prevents l/R insult by keeping Kupffer cetl activation in check. We propose following specific aims: (1). To evaluate local vs. systemic ceil requirements for HO-1-facilitated cytoprotection; By using HO-1 Tg mice, we will determine impact of local (endothelial/parenchymal) vs. systemic (lymphocyte) HO-1 expression. We will analyze which hepatic components vs. spleen T cell subsets are instrumental in HO-1 effects. The role of STAT6 in the emergence of a dominant HO-1-dependent cytoprotective type-2 T cell will be assessed. (2). To dissect apoptotic/anti-apoptotic pathways in the mechanism of HO-1-facilitated cytoprotection: We plan to determine the molecular basis of HO-1 mediated cytoprotection in OLT recipients and in primary mouse hepatocyte cultures upon the death signaling machinery (TNF/FasL), and apoptotic stimuli (ROS). This will include activation of caspases, cytochrome c release, and expression of anti-/pro-apoptotic genes. We will analyze whether HO-1-mediated depression of apoptotic machinery in hepatocytes and upregulation of endothelial anti-apoptotic molecules represents local hepatic or systemic T cell-dependent feature. (3). To explore cross-talk between HO-1 and TLR 4 complex - I/R injury a case for innate immunity? We will study how HA, shed from damaged sinusoidai endothelial cells, interacts with Kupffer cells, to what extent HA triggers expression/activation of Kupffer ceils in TLR 4 mutant/deficient vs. WT mice. The ability of sHA to affect hepatic I/R insult in TLR 4 mutant/TLR 4 KO mice will be probed. We will analyze by which mechanism depression of HO activity affects innate immunity balance, and triggers phenotypic/functional TLR4 activation.

描述（由申请人提供）： LSCHEMIA/REPEREFUSION（I/R）侮辱仍然是原位肝移植（OLT）的主要局限性之一。 该提议建立在我们对诱导OLT中血红素氧酶-1（HO-1）表达的新方法的研究中获得的见解。我们假设：（i）HO-I促进了系统的Mileu，该系统通过STAT6途径导致出现主要的“ Cytoprotectlve”型2型T细胞子集； （ii）HO-1抑制凋亡机制和触发器2型抗凋亡细胞保护性机制； （iii）透明质酸（HA）提供了一个“危险”信号，以激活库普弗细胞上的Toll样受体4（TLR 4）复合物； HO-1-TLR 4串扰可以通过检查Kupffer CETL激活来防止L/R损害。我们提出以下特定目的：（1）。评估局部与系统性CEIL的要求，对HO-1的细胞保护作用；通过使用HO-1 TG小鼠，我们将确定局部（内皮/实质）与全身性（淋巴细胞）HO-1表达的影响。我们将分析哪些肝脏成分与脾脏T细胞子集对HO-1效应有用。 STAT6在主要依赖HO-1依赖性细胞保护型2型T细胞的出现中的作用将得到评估。 （2）。在HO-1-辅助细胞保护的机理中剖析凋亡/抗凋亡途径：我们计划确定OLT受体中HO-1介导的细胞保护的分子基础，以及在死亡信号机械（TNF/FASL）和凋亡刺激（ROSE）（tnf/FASL）上的原代小鼠肝细胞培养物中的分子基础。这将包括胱天蛋白酶的激活，细胞色素C释放以及抗/促凋亡基因的表达。我们将分析HO-1介导的肝细胞中凋亡机制的抑郁症以及内皮抗凋亡分子的上调代表局部肝或全身T细胞依赖性特征。 （3）。探索HO-1和TLR 4复合物之间的串扰-I/R伤害是先天免疫的案例？我们将研究如何与kupffer细胞相互作用的损坏的正弦内皮细胞脱落，在多大程度上，HA在TLR 4突变体/缺陷/缺陷中与WT小鼠的表达/激活。将探测SHA在TLR 4突变体/TLR 4 KO小鼠中影响肝I/R损伤的能力。我们将通过哪种机理抑制HO活性影响先天免疫平衡，并触发表型/功能性TLR4激活。