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.

在系统性的情况下，包括心肌梗塞（MI）和中风在内的动脉血栓形成的风险有所增加与慢性感染有关的疾病状态，包括癌症，糖尿病，动脉粥样硬化和肥胖症。在这些环境和最近的研究中，不适当的血小板激活是血栓形成的驱动机制表明患病状态下血小板激活的机制可能与正常健康的机制不同状况。解剖这些新型机制是该多PI提案的核心目标。最新出版初步研究表明，内源性危险信号众所周知是在患病期间产生的包括氧化的低密度脂蛋白，晚期糖化蛋白，细胞衍生的微粒和包括氧化的状态 S100A都在与特定的血小板接收器CD36相互作用，以启动促进的细胞内信号血小板激活和血栓形成。发现进一步的血小板表达了MAP激酶ERK5，这是已知的活性氧的传感器（ROS）。然后，血小板ERK5被证明充当氧化还原开关。细胞外ROS在缺血性条件下，促进血小板激活并增强心肌损伤在Mi期间；发现ERK5因响应OXLDL介导的ROS而在CD36的下游激活一代。 ERK5的血小板特异性缺失改善血小板激活和促脉症状态与高脂氧化物应激有关。因此，我们假设ERK5充当了中心的“节点” 病理血小板激活，对接收器介导的细胞内信号响应于CD36和非 - 接收器通过组织缺血介导的细胞外信号（ROS），通过其信号和蛋白质介导监管活动。特定目标1将检验以下假设：CD36信号产生的特定ROS 通过激活ERK5将血小板保持在促活激活状态。人体体外和小鼠体内研究将使用遗传模型，饮食诱导的疾病模型和高度特异性的CD36配体鉴定关键细胞 CD36介导的ERK5激活所必需的膜合作伙伴以及ROS的下游效应和血小板中的ERK5；并确定ERK5信号如何与血小板的“经典”途径集成激活以促进血栓形成。 AIM 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的翻译和/或蛋白质泛素化。体外和体内模型将用于确定响应ROS的血小板蛋白表达的变化是否取决于蛋白合成，降解或两者兼而有之。 AIM 3将确定在设置中血小板ERK5激活的机制组织缺血和细胞外ROS会增加组织和器官功能障碍。遗传和药理将使用MI和氧化应激的方法和体内模型。通过了解血小板的机制 ERK5激活和下游途径这些研究将提供对“失调”血小板功能的见解在病理状况和缺血环境中，可能导致新的治疗靶标和更好了解为什么在健康条件下基于血小板功能的当前疗法不足。