HO1 AND TLR4 IN LIVER ISCHEMIA/REPERFUSION INJURY IN TRANSPLANT RECIPIENTS

HO1 和 TLR4 在移植受者肝缺血/再灌注损伤中的作用

• 批准号: 7657516
• 负责人: Jerzy W Kupiec-Weglinski
• 金额: $ 36.96万
• 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 2014-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7657516
• 关键词: Ablation; Acute; Affect; Age; Aging; Anti-Inflammatory Agents; Anti-inflammatory; Antioxidants; Biological Response Modifiers; Blood Transfusion; CXCL10 gene; Cells; Cellular Stress Response; Chronic; Clinical; Clinical Data; Cryopreservation; Disease; Equilibrium; Etiology; Failure; Feedback; Functional disorder; Funding; General Population; Genes; Graft Rejection; HMGB1 gene; Harvest; Heat shock proteins; Hepatic; Hepatocellular Damage; Hepatocyte; Homeostasis; IRF3 gene; Immune; Immune response; Immunosuppression; Incidence; Inflammation; Interferons; Ischemia; Kidney; Kupffer Cells; Ligands; Link; Liver; Liver diseases; Mediating; Modality; Modeling; Molecular; Mus; Myocardial Ischemia; Natural Immunity; Nuclear; Organ; Organ Donor; Organ Preservation; Organ Transplantation; Outcome; Oxidants; Oxidation-Reduction; Oxidative Stress; Pathway interactions; Patients; Play; Population; Pregnancy; Process; Reperfusion Injury; Research; Rodent Model; Role; Severities; Signal Pathway; Signal Transduction; Small Interfering RNA; Staging; System; TLR2 gene; TLR4 gene; Texture; Therapeutic; Toll-like receptors; Transgenes; Transplant Recipients; Transplantation; Warm Ischemia; activation product; biological adaptation to stress; cell type; clinically relevant; combat; design; experience; facial transplantation; gene therapy; heme oxygenase-1; improved; improved functioning; insight; liver ischemia; liver transplantation; mouse model; novel; novel strategies; overexpression; prevent; prospective; public health relevance; response; success; type I interferon receptor

DESCRIPTION (provided by applicant): Orthotopic liver transplantation (OLT) is an effective therapeutic modality for the treatment of end-stage liver disease. However, ischemia/reperfusion injury (IRI), an exogenous Ag-independent component of the "harvesting" insult, remains one of the key limitations after OLT. Moreover, the quality of donor organs decreases along with the aging of general population and associated pathological conditions. This proposal is built upon the insights gained from our previous studies on a novel approach of combating organ IRI by locally inducing heme oxygenase-1 (HO-1) that protects against the severity of oxidative stress. Indeed, local HO-1 expression and functional response should be considered as a denominator of donor organ quality. We have also shown the role of innate immunity in liver IRI. Indeed, by utilizing a non-transplant mouse warm liver IRI model, we have documented that: (i) TLR4 activation mediates liver inflammation via IRF-3 pathway; (ii) CXCL10 regulates liver innate immune responses; (iii) Type-I IFN mediates synergy between Kupffer cells and hepatocytes, and (iv) endogenous TLR ligands are crucial in TLR4 activation-induced "sensoring" and IRI. To mimic the clinical scenario, we have recently developed a mouse model of prolonged liver cold preservation, followed by syngeneic OLT. We hypothesize that cross talk between the opposing pathways, i.e., HO-1 in the donor organ, and TLR4 in OLT recipients is instrumental in the mechanism of liver IRI. Our corollary hypothesis states that Nrf2, a bZIP transcriptional factor that regulates stress response/regulates cell redox balance, controls dysregulated HO-1 - TLR4 signaling during IRI. Aim 1. To analyze mechanisms by which suboptimal HO-1 deficient liver grafts affect IRI sequel and TLR4 signaling in OLT recipients. Livers from WT, HO-1 deficient (; KO) and HO-1 overexpressing (Tg) donors will be stored for 18 h at 4 C, and then transplanted to syngeneic WT mice. We will study (i) whether HO-1 expression and by which donor liver cell type affect IRI and OLT outcome, and (ii) if and how the local HO-1 expression in OLT affects host TLR4 signaling. Aim 2. To dissect mechanisms by which modulation of recipient TLR4 signaling ameliorate IRI and improve the outcome of suboptimal OLTs. Livers from WT or HO-1 deficient (; KO) donors will be stored for 18 h at 4 C, and then transplanted to syngeneic TRIF- or Type I IFN receptor (IFNAR)-KO mice. We will study (i) whether selective ablation of downstream TLR4 signaling in the host affect IRI sequel/OLT inflammation, and (ii) if HO-1- TLR4 cross talk can influence HMGB1-mediated IR inflammation and organ damage in OLT recipients. Aim 3. To analyze mechanisms by which Nrf2 signaling influence IRI in OLT recipients. Livers from donor mice that are Nrf2-deficient or Nrf2-overexpressing (hepatocyte-specific conditional disruption of the Keap1 gene, which represses Nrf2) will be stored for 18 h at 4 C, and transplanted to WT mice. By modulating oxidant (HO-1 siRNA) and inflammatory (anti-HMGB1/rHMGB1) responses, we will study the regulatory function of Nrf2 upon (i) HO-1 vs (ii) TLR4 signaling pathways during IRI in OLT recipients. PUBLIC HEALTH RELEVANCE: Host sensitization remains the major problem in clinical organ transplantation. Many prospective transplant patients are sensitized following blood transfusions, pregnancies, or failed previous grafts. This project is designed to analyze cell mediated mechanisms leading to accelerated rejection of organ allografts and ultimately to design novel and much needed therapeutic approaches to ameliorate transplant rejection in sensitized patients.

描述（由申请人提供）：原位肝移植（OLT）是治疗终末期肝病的有效治疗方式。然而，缺血/再灌注损伤（IRI）是“收获”侮辱的外源性AG独立组成部分，仍然是OLT后的关键局限性之一。此外，随着普通人群和相关病理状况的衰老，供体器官的质量降低。该提议建立在我们先前对局部诱导器官IRI的新方法的研究中获得的见解，该方法通过局部诱导血红素氧酶-1（HO-1）来防止氧化应激的严重程度。实际上，局部HO-1表达和功能反应应被视为捐赠器官质量的分母。我们还展示了先天免疫在肝脏IRI中的作用。实际上，通过利用非移植小鼠温暖的肝脏IRI模型，我们记录了：（i）TLR4激活通过IRF-3途径介导肝脏炎症； （ii）CXCL10调节肝脏先天免疫反应； （iii）I型IFN介导了Kupffer细胞和肝细胞之间的协同作用，并且（IV）内源性TLR配体在TLR4激活诱导的“感觉”和IRI中至关重要。为了模仿临床方案，我们最近开发了一种长时间肝冷保护的小鼠模型，然后是Syngeneic OLT。我们假设相反的途径之间的串扰，即供体器官中的HO-1，而OLT接受者中的TLR4在肝脏IRI机制中发挥了作用。我们的推论假设指出，NRF2是调节应力反应/调节细胞氧化还原平衡的BZIP转录因子，控制IRI期间HO -1 -TLR4信号失调。目的1。分析次优的HO-1缺陷肝移植会影响OLT受体中IRI续集和TLR4信号传导的机制。 WT的肝脏，HO-1缺陷（; KO）和HO-1过表达（TG）供体将在4 C下储存18小时，然后移植到Syngeneic WT小鼠中。我们将研究（i）HO-1表达以及供体肝细胞类型是否影响IRI和OLT结果，以及（ii）IF以及OLT中局部HO-1表达如何影响宿主TLR4信号传导。目标2。解剖受体TLR4信号传导改善IRI并改善次优OLT的结果的机制。 WT或HO-1缺陷（; KO）供体的肝脏将在4 C下储存18小时，然后移植至Syngeneic Trif-或I型IFN受体（IFNAR）-KO小鼠。我们将研究（i）宿主中下游TLR4信号的选择性消融是否会影响IRI续集/OLT炎症，并且（ii）如果HO-1-TLR4交叉讲座会影响OLT受体中HMGB1介导的IR炎症和器官损害。目的3。分析NRF2信号传导在OLT受体中影响IRI的机制。 NRF2缺陷型或过表达NRF2的供体小鼠的肝脏（抑制NRF2的KEAP1基因的肝细胞特异性条件破坏）将在4 C下储存18 h，并将其移植到WT小鼠中。通过调节氧化剂（HO-1 siRNA）和炎症（抗HMGB1/RHMGB1）响应，我们将研究NRF2在OLT接受者IRI期间IRI期间（I）HO-1 VS（I）HO-1 VS（I）HO-1 VS（I）的调节功能。公共卫生相关性：宿主敏化仍然是临床器官移植中的主要问题。输血，妊娠或以前的移植物失败后，许多前瞻性移植患者受到敏感。该项目旨在分析细胞介导的机制，从而加速了器官同种异体移植物的排斥，并最终设计出设计新颖的和急需的治疗方法，以减轻敏化患者的移植排斥反应。