Mechanisms of Muscle Afferent Sensitization after Ischemia

缺血后肌肉传入敏化的机制

基本信息

批准号：
8914940
负责人：
Michael P Jankowski
金额：
$ 32.51万
依托单位：
CINCINNATI CHILDRENS HOSP MED CTR
依托单位国家：
美国
项目类别：
财政年份：
2013
资助国家：
美国
起止时间：
2013-09-17 至 2016-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8914940
关键词：
ASIC channel Acute Affect Afferent Neurons Anatomy Animals Behavioral Biological Assay Cardiovascular Diseases Cardiovascular system Cells Complex Regional Pain Syndromes Cutaneous Data Development Disease Drug Formulations Esthesia Event Fatigue Fiber Gene Expression Genes Goals Health Heating Hematological Disease Homeostasis Human Individual Injury Ischemia Knowledge Lead Mechanics Mediating Modeling Molecular Mus Muscle Musculoskeletal Pain Myalgia Nerve Neurons Nociception Nociceptors Pain Patients Pattern Peripheral Peripheral Nerves Peripheral Vascular Diseases Phase Phenotype Physiological Play Population Preparation Property Purinoceptor Reflex action Reperfusion Therapy Reporting Reverse Transcriptase Polymerase Chain Reaction Role Running Sickle Cell Anemia Small Interfering RNA Spinal Cord Spinal Ganglia Stimulus Structure of ulnar nerve System Techniques Testing Therapeutic Studies Tissues United States Up-Regulation artery occlusion base behavior test brachial artery chronic pain experience grasp in vivo insight median nerve molecular phenotype neurochemistry novel pain behavior pain receptor prevent public health relevance receptor research study response sensor sickle cell crisis

项目摘要

DESCRIPTION (provided by applicant): Musculoskeletal pain resulting from tissue ischemia with reperfusion is a major health issue that affects millions of people in the United States. Peripheral ischemia/ reperfusion occurs in blood disorders like sickle cell disease, and in cardiovascular disorders such as peripheral vascular disease. Ischemia/ reperfusion are also thought to be the underlying cause of complex regional pain syndrome. While much is known about the functional properties and plasticity of cutaneous nociceptors following peripheral injuries and how these fibers contribute to pain, relatively little is known about the functional properties of group III and IV muscle afferents and their role in muscle pain development. The major goal of this proposal is to determine the molecular mechanisms of muscle afferent sensitization that may underlie muscle pain during ischemia and after tissue reperfusion. We hypothesize that these distinct phases cause differential changes in heat, mechanical and chemo-sensitivity in muscle afferents, which are mediated by upregulation of purinergic receptors during ischemia and acid sensing ion channels after reperfusion leading to muscle pain. In order to increase our knowledge of muscle afferents, we developed a novel ex vivo forepaw muscle, median & ulnar nerves, dorsal root ganglion (DRG), spinal cord recording preparation that enables us to comprehensively phenotype these afferents in mouse. We are also able to analyze the central anatomy, and the neurochemical or molecular phenotypes of these afferents using combinations of ex vivo recording with immunocytochemical and single cell RT-PCR analyses. In Specific Aim 1, we will determine if upregulation of purinergic receptors, P2Y1 and P2X5, regulate the observed changes in heat and chemosensitivity in muscle afferents, respectively during ischemia using in vivo siRNA-mediated knockdown of these genes in single peripheral nerves in conjunction with ex vivo recording preparations. Next, in Specific Aim 2, we will utilize a similar approach to SA1 except we will determine if upregulation of ASIC1 and ASIC3 regulate the novel changes in mechanical and metabolite responses in muscle afferents, respectively after transient ischemia with tissue reperfusion. Finally, in Specific Aim 3, we will determine if upregulation of P2Y1 and P2X5 regulate muscle pain during ischemia while upregulation of ASIC1 and ASIC3 regulate muscle pain after reperfusion by analyzing the effects of receptor knockdown on recognized muscle pain behavior tests between these two phases. This study will enable us to characterize the changes in both non-nociceptive and nociceptive muscle afferents after ischemia/ reperfusion and identify unique mechanisms associated with muscle afferent sensitization that underlie muscle pain development. This may lead to the formulation of more appropriate treatments for musculoskeletal pain associated with ischemia/ reperfusion that target the proper pain receptor(s) or primary afferent subpopulation(s).

描述（由申请人提供）：由再灌注的组织缺血引起的肌肉骨骼疼痛是一个主要的健康问题，影响了美国数百万的人。周围缺血/再灌注发生在诸如镰状细胞病等血液疾病中，以及心血管疾病（如周围血管疾病）。缺血/再灌注也被认为是复杂区域疼痛综合征的根本原因。尽管对外周损伤后皮肤伤害感受器的功能特性和可塑性知之甚少，以及这些纤维如何导致疼痛，但对III和IV组肌肉传入的功能性能及其在肌肉疼痛发育中的作用相对较少。该提议的主要目的是确定肌肉传入敏化的分子机制，这些肌肉传入敏化的肌肉疼痛是缺血期间和组织再灌注后肌肉疼痛的基础。我们假设这些不同的阶段会导致肌肉传入中的热，机械和化学敏感性的变化，这些变化是通过在缺血和再灌注后的缺血感和酸感应离子通道的上调导致肌肉疼痛的上调。为了提高我们对肌肉传入的了解，我们开发了一种新型的前脚部肌肉，中值和尺神经，背根神经节（DRG），脊髓记录准备准备，使我们能够在小鼠中全面表观表型。我们还能够使用离体记录与免疫细胞化学和单细胞RT-PCR分析的组合来分析这些传入的中央解剖学以及这些传入的神经化学或分子表型。在特定目标1中，我们将确定嘌呤能受体P2Y1和P2X5的上调是否调节在缺血期间使用体内siRNA介导的在与Ex Vivo Recordations Injunction相结合的单个外围神经中这些基因的体内siRNA介导的这些基因的在缺血期间观察到的热量和化学敏感性的变化。接下来，在特定的目标2中，我们将使用类似的SA1方法，除非我们确定ASIC1和ASIC3的上调是否在肌肉传入中分别调节肌肉传入中机械和代谢物反应的新变化，并在瞬时缺血并进行了组织再灌注后。最后，在特定的目标3中，我们将确定P2Y1和P2X5的上调是否在缺血期间调节肌肉疼痛，而ASIC1和ASIC3的上调通过分析受体敲低对这两个阶段之间公认的肌肉疼痛行为测试的影响来调节肌肉疼痛。这项研究将使我们能够表征缺血/再灌注后的非伤害性和伤害性肌肉传入的变化，并确定与肌肉疼痛发展相关的与肌肉传入敏感性相关的独特机制。这可能会导致对与缺血/再灌注有关的肌肉骨骼疼痛的更合适的治疗方法，该肌肉/再灌注针对适当的疼痛受体或原发性传入亚群（S）。