Retinoid Mediated Protection Against Reactive Oxygen Species Induced Cytotoxicity

类维生素A介导的针对活性氧诱导的细胞毒性的保护

• 批准号: 9231148
• 负责人: Serrine S Lau
• 金额: $ 25.59万
• 依托单位: WAYNE STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-09-01 至 2017-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9231148
• 关键词: Retinoid; Mediated; Protection; Against; Reactive

Project Summary We have shown that retinoid signaling is engaged during 11-deoxy-16,16-dimethyl PGE2 (DDM-PGE2) mediated cytoprotection against reactive oxygen species (ROS) induced necrotic/oncotic cell death. Proteomics analyses revealed that cytoprotection is associated with the increased synthesis of a select number of proteins, including retinol binding protein (RBP), actin, and glucose-regulated protein 78 (Grp78). We subsequently confirmed that all-trans-retinoic acid (aTRA) replicates DDM-PGE2-mediated cytoprotection in vitro, and more importantly, a single dose of aTRA (1 mg/kg, 6h pretreatment) completely protects mice from renal ischemia/reperfusion (I/R) injury. Furthermore, at this therapeutic dose, aTRA induces Nrf2-responsive antioxidant HO-1 and NQO1 genes, as well as nuclear retinoic acid receptors RAR?, RAR?2, RAR?2, and retinoid X receptors RXR? in the kidney. The revised application is designed to determine the molecular mechanisms by which aTRA affords cytoprotection in vitro, and the extent to which this mechanism(s) of cytoprotection is recapitulated in vivo. Our central hypothesis is that aTRA-induced cytoprotection is mediated by mechanisms similar to ischemic preconditioning. In Specific Aim 1 we propose to determine the ability of aTRA to offer cytoprotection in an in vitro model (human renal epithelial HK-2 cells) of hypoxia/reoxygenation injury, and to optimize protocols for aTRA-mediated cytoprotection in an in vivo ischemia/reperfuson model (IR). We will also ascertain whether the protective effects are mediated, at least in part, via the upregulation of anti-oxidant enzymes. The biological effects of retinoids are typically mediated via interaction with their cognate nuclear receptors, namely, retinoic acid receptors (RAR) and retinoid X receptors (RXR). The extent to which RAR and/or RXR participate in aTRA- mediated cytoprotection is not known, and Specific Aim 2 will determine, in both the in vitro and in vivo models of I/R, whether aTRA-mediated cytoprotection requires interaction with RAR and/or RXR. Specific Aims 1 and 2 are therefore designed to establish the recruitment of retinoid signaling as a potential therapeutic intervention in conditions where ROS play an important role in the pathology of the disease, such as those involving ischemia reperfusion injury (Specific Aim 1), and to initially characterize the pharmacological basis of this effect (Specific Aim 2). The third and final Specific Aim is designed to identify the molecular mechanisms by which aTRA accomplishes cytoprotection, with each sub- aim focusing on a target that has already been identified in preliminary studies as playing an important role in the cytoprotective response. Specifically, those mediators are Nrf2, Grp78, and p38 MAPK, each of which is also a key mediator of ischemia preconditioning. Specific Aim 3 will therefore determine whether (i) aTRA- mediated induction of the anti-oxidant stress response is dependent upon Nrf2; (ii) aTRA-mediated cytoprotection requires the recruitment of the ER (Grp78) mediated stress response pathway; (iii) the recruitment of Nrf2 by aTRA is dependent on p38 MAPK-Grp78 interactions; and (iv) the mechanism(s) of cytoprotection identified in the in vitro model are recapitulated in the in vivo model by testing aTRA induced renoprotection in Nrf2-/- mice. The significance of the current studies resides in their potential to enhance our understanding of retinoid mediated cytoprotection at the molecular and cellular level, which can subsequently provide insights into novel therapeutic strategies effective for clinical interventions during chemical induced tissue injury or hypoxia/ischemia-reperfusion injury.

项目摘要 我们已经证明，在11-脱氧-16，16-二甲基前列腺素E2（DDM-PGE2）介导的 对活性氧（ROS）诱导的坏死/坏死细胞死亡的细胞保护作用。蛋白质组学分析 揭示了细胞保护作用与选择数量的蛋白质的合成增加有关，包括 视黄醇结合蛋白（RBP）、肌动蛋白和葡萄糖调节蛋白78（Grp78）。我们随后证实， 全反式维甲酸（aTRA）在体外复制了DDM-PGE 2介导的细胞保护作用，更重要的是， 单剂量aTRA（1mg/kg，预处理6h）完全保护小鼠肾缺血/再灌注（I/R） 损伤此外，在该治疗剂量下，aTRA诱导Nrf2响应性抗氧化剂HO-1和NQO1基因， 以及核视黄酸受体RAR？，RAR？2、RAR？2、维甲酸X受体RXR？在肾脏中。 修订后的申请旨在确定aTRA提供的分子机制 体外细胞保护，以及这种细胞保护机制在体内重演的程度。我们 中心假设是aTRA诱导的细胞保护作用是由类似于缺血的机制介导的， 预处理在具体目标1中，我们建议确定aTRA在一种免疫缺陷中提供细胞保护的能力。 体外模型（人肾上皮HK-2细胞）缺氧/复氧损伤，并优化方案， 在体内缺血/再灌注模型（IR）中aTRA介导的细胞保护。我们亦会确定 保护作用至少部分地通过抗氧化酶的上调来介导。生物 类维生素A的作用通常通过与它们的同源核受体，即视黄酸 酸受体（RAR）和类维生素A X受体（RXR）。RAR和/或RXR参与aTRA的程度 在体外和体内模型中，介导的细胞保护作用尚不清楚，具体目标2将确定 对于I/R，aTRA介导的细胞保护是否需要与RAR和/或RXR相互作用。具体目标1和2 因此，旨在建立类维生素A信号的募集作为一种潜在的治疗干预， 其中ROS在疾病的病理学中起重要作用的病症，例如涉及缺血的病症 再灌注损伤（具体目标1），并初步表征这种作用的药理学基础（具体目标1）， 目标2）。第三个也是最后一个特异性目的旨在确定aTRA 完成细胞保护，每个子目标都集中在已经确定的目标上， 初步研究认为在细胞保护反应中起重要作用。具体而言，这些调解人是 Nrf2、Grp78和p38 MAPK，它们中的每一个也是缺血预处理的关键介质。具体目标3 因此将确定（i）aTRA介导的抗氧化应激反应的诱导是否依赖于 （ii）aTRA介导的细胞保护需要ER（Grp78）介导的应激的募集 （iii）aTRA对Nrf2的募集依赖于p38 MAPK-Grp78相互作用;和（iv） 在体外模型中鉴定的细胞保护机制在体内模型中通过测试 aTRA在Nrf2-/-小鼠中诱导肾保护。当前研究的重要性在于它们的潜力， 增强我们对维甲酸介导的细胞保护作用在分子和细胞水平上的理解， 随后提供了对化学治疗期间临床干预有效新治疗策略的见解， 诱导的组织损伤或缺氧/缺血-再灌注损伤。