ERK5 and CD36 link oxidative stress to platelet dysfunction and ischemic injury

ERK5 和 CD36 将氧化应激与血小板功能障碍和缺血性损伤联系起来

基本信息

批准号：
10323025
负责人：
CRAIG N MORRELL
金额：
$ 63.2万
依托单位：
MEDICAL COLLEGE OF WISCONSIN
依托单位国家：
美国
项目类别：
财政年份：
2019
资助国家：
美国
起止时间：
2019-01-01 至 2023-12-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10323025
关键词：
Address Atherosclerosis Automobile Driving Biological Models Blood Blood Circulation Blood Platelets Blood coagulation CD36 gene Cell membrane Cells Chronic Chronic Disease Data Defect Diabetes Mellitus Diet Disease Disease model Dyslipidemias Environment Event Functional disorder Future Gene Expression Generations Genetic Genetic Models Goals Hemostatic Agents Human In Vitro Infarction Inflammation Inflammatory Interruption Intracellular Signaling Proteins Investigation Ischemia Knowledge Lead Ligands Link MAP Kinase Gene MAPK7 gene Malignant Neoplasms Mediating Megakaryocytes Mitogen-Activated Protein Kinases Mus Myocardial Infarction Obesity Organ Oxidation-Reduction Oxidative Stress Pathologic Pathway interactions Peptides Pharmacology Platelet Activation Protein Biosynthesis Proteins Publishing Reactive Oxygen Species Regulation Risk Series Signal Pathway Signal Transduction Signaling Protein Site Stress Stroke Systemic disease Testing Therapeutic Intervention Therapeutic Uses Thrombosis Thrombus Tissue Model Tissues Translations Ubiquitination base clinically significant extracellular heart damage in vivo in vivo Model insight ischemic injury myocardial damage new therapeutic target novel oxidant stress oxidized low density lipoprotein platelet function preservation prevent protein degradation protein expression receptor response sensor targeted treatment therapeutic target thrombotic tissue injury

项目摘要

Risk of arterial thrombosis, including myocardial infarction (MI) and stroke, is increased in the setting of systemic disease states associated with chronic inflammation, including cancer, diabetes, atherosclerosis and obesity. Inappropriate platelet activation is a driving mechanism of thrombosis in these settings and recent studies suggest that mechanisms of platelet activation in diseased states may be different from those in normal healthy conditions. Dissecting these novel mechanisms is the central goal of this multi-PI proposal. Recent published and preliminary studies showed that endogenous danger signals well known to be generated during diseased states, including oxidized low density lipoprotein, advanced glycated proteins, cell-derived microparticles, and S100A peptides all interact with a specific platelet receptor, CD36, to initiate intracellular signals that promote platelet activation and thrombosis. Furthemore platelets were found to express the MAP kinase ERK5, a known sensor of reactive oxygen species (ROS). Platelet ERK5 was then shown to act as a redox switch responsive to extracellular ROS under ischemic conditions, promoting platelet activation and enhancing myocardial damage during MI; and ERK5 was found to be activated downstream of CD36 in response to oxLDL-mediated ROS generation. Platelet specific deletion of ERK5 ameliorated platelet activation and the pro-thrombotic state associated with hyperlipidemic oxidant stress. We thus hypothesize that ERK5 serves as a central “node” in pathologic platelet activation, responding to receptor-mediated intracellular signals triggered by CD36 and non- receptor mediated extracellular signals (ROS) mediated by tissue ischemia, through both its signaling and protein regulation activities. Specific aim 1 will test the hypothesis that specific ROS generated by CD36 signaling maintains platelets in a pro-activated state via activation of ERK5. Human In vitro and mouse in vivo studies will use genetic models, diet-induced disease models, and highly specific CD36 ligands to identify critical cell membrane partners necessary for CD36-mediated ERK5 activation, as well as downstream effectors of ROS and ERK5 in platelets; and to determine how ERK5 signaling integrates with “classic” pathways of platelet activation to promote thrombosis. Aim 2 will test the hypothesis that ERK5 regulates platelet protein expression by modulating platelet protein translation and/or protein ubiquitination. In vitro and in vivo models will be used to determine whether changes in platelet protein expression in response to ROS are dependent on protein synthesis, degradation, or both. Aim 3 will determine mechanisms by which platelet ERK5 activation in the setting of tissue ischemia and extracellular ROS increases tissue and organ dysfunction. Genetic and pharmacologic approaches and in vivo models of MI and oxidant stress will be used. By understanding mechanisms of platelet ERK5 activation and downstream pathways these studies will provide insights into `dysregulated' platelet function in pathologic conditions and ischemic environments that may lead to new therapeutic targets and better understanding of why current therapies based on platelet function in healthy conditions are inadequate.

在全身性心脏病的情况下，动脉血栓形成的风险会增加，包括心肌梗死 (MI) 和中风。与慢性炎症相关的疾病状态，包括癌症、糖尿病、动脉粥样硬化和肥胖。在这些情况和最近的研究中，不适当的血小板激活是血栓形成的驱动机制表明疾病状态下血小板活化的机制可能与正常健康状态下的不同剖析这些新颖的机制是最近发布的多 PI 提案的中心目标。初步研究表明，众所周知，在患病期间会产生内源性危险信号状态，包括氧化低密度脂蛋白、高级糖化蛋白、细胞衍生的微粒和 S100A 肽均与特定血小板受体 CD36 相互作用，启动细胞内信号，促进此外，血小板还被发现表达 MAP 激酶 ERK5，这是一种已知的激酶。活性氧 (ROS) 传感器随后被证明可充当响应氧化还原开关。缺血条件下细胞外ROS，促进血小板活化，增强心肌损伤在 MI 期间，ERK5 被发现在 CD36 下游响应 oxLDL 介导的 ROS 被激活血小板特异性删除 ERK5 可改善血小板活化和促血栓形成状态。因此，我们推测 ERK5 是高脂血症氧化应激的中心“节点”。病理性血小板活化，响应由 CD36 和非-受体介导的细胞内信号触发受体介导的细胞外信号（ROS）由组织缺血通过其信号传导和蛋白质介导具体目标 1 将检验 CD36 信号传导产生特定 ROS 的假设。通过激活 ERK5 维持血小板处于促激活状态人类体外和小鼠体内研究将使用遗传模型、饮食诱发的疾病模型和高度特异性的 CD36 配体来识别关键细胞 CD36 介导的 ERK5 激活所需的膜伴侣以及 ROS 的下游效应器和血小板中的 ERK5；并确定 ERK5 信号如何与血小板的“经典”途径整合目标 2 将检验 ERK5 调节血小板蛋白表达的假设。通过调节血小板蛋白翻译和/或蛋白泛素化，将用于体外和体内模型。确定血小板蛋白表达对 ROS 的反应的变化是否依赖于蛋白质目标 3 将通过哪种机制决定血小板 ERK5 的激活。组织缺血和细胞外活性氧的增加会增加组织和器官功能障碍。通过了解血小板的机制，将使用 MI 和氧化应激的方法和体内模型。 ERK5 激活和下游这些通路研究将为“失调”血小板功能提供见解在病理条件和缺血环境中可能会导致新的治疗目标和更好的治疗了解为什么当前在健康条件下基于血小板功能的疗法是不够的。