Molecular receptors on Group III-IV sensory neurons detecting muscle metabolites

描述（由申请人提供）：III-IV组感觉神经元上的分子受体检测肌肉代谢物慢性心力衰竭、慢性阻塞性肺病（COPD）和其他慢性疲劳性疾病引起的疲劳是严重的、使人衰弱的，并对这些患者的长期结局产生不良影响。更多的患者受到特发性、损伤或疾病引起的短期疲劳和肌痛的影响，这些疲劳和肌痛有时会通过治疗缓解，或者由于未知的原因变成慢性。大量证据表明，III/IV组肌肉传入的外周感觉失调和自主神经失调可能导致或促成慢性心力衰竭的过度疲劳。我们的长期目标是确定向感觉和运动系统发出疲劳信号的基本机制，并确定在心力衰竭和COPD等疾病中引起疲劳增强的机制。在接下来的三年里，我们提出了一个全面的评估III/IV组肌肉传入神经元上的分子受体，赋予这些专门的末梢检测和信号的能力，肌肉代谢物的增加，发生肌肉收缩和运动。本文提出的实验将使用：用途：1）创新的神经元收获和定量实时PCR（qPCR）来确定哪些分子受体在III/IV组传入神经元中选择性表达。2)钙成像、细胞收获和qPCR，以确定疲劳选择性神经元如何选择性地编码非疼痛水平的代谢物。3)免疫组化以确定表达的mRNA是否是插入膜中的翻译蛋白。4)代谢物激活电流的全细胞记录，以确定分子受体蛋白的功能;和5）神经肌肉制备物中的单单位电生理学记录，以确定哪种代谢物原位激活这些感觉神经元。这些实验的结果将为疲劳作为一个综合系统的概念提供基础科学背景，该综合系统对心血管/自主神经系统、疲劳的感觉-知觉体验和运动系统抑制具有强大的影响。这一概念以及所发现的分子受体将为心力衰竭患者、COPD患者和其他患有长期不明原因疲劳的患者所经历的过度疲劳提供合理的、有针对性的有效治疗。

DESCRIPTION (provided by applicant): Molecular receptors on Group III-IV sensory neurons detecting muscle metabolites Fatigue due to chronic heart failure, chronic obstructive pulmonary disorder (COPD), and other chronic fatiguing disorders is serious, debilitating, and creates poor prognoses for long-term outcomes in these patients. Many more patients are affected by idiopathic, injury, or disease-caused short-term fatigue and myalgia that sometimes remits with treatment or for unknown reasons becomes chronic. Considerable evidence indicates that peripheral sensory dysregulation of group III/IV muscle afferents, and autonomic dysregulation may cause or contribute to the excessive fatigue of chronic heart failure. Our long-term goal is to determine the fundamental mechanisms that signal fatigue to sensory and motor systems, and determine the mechanisms that cause enhanced fatigue in diseases such as heart failure and COPD. In the next three years, we propose a comprehensive evaluation of the molecular receptors on group III/IV muscle afferent neurons that endow these specialized endings with the ability to detect and signal the increases in muscle metabolites that occur with muscle contraction and exercise. Experiments proposed here will use: 1) innovative neuron harvesting and quantitative real-time, PCR (qPCR) to determine which molecular receptors are expressed selectively in group III/IV afferent neurons. 2) calcium imaging, cell harvesting and qPCR to determine how fatigue-selective neurons selectively encode non-painful levels of metabolites. 3) immunohistochemistry to determine if mRNA expressed is translated protein inserted into membrane. 4) whole-cell recording of metabolite activated currents to determine the function of the molecular receptor proteins; and 5) single unit electrophysiological recording in a nerve muscle preparation to determine which metabolites activate these sensory neurons in situ. The results of these experiments will provide the basic science background for the concept of fatigue as an integrated system with powerful influence on the cardiovascular/autonomic system, the sensory-perceptual experience of fatigue, and motor system inhibition. This concept, and the molecular receptors discovered will lead to rational, targeted effective treatments for the excessive fatigue experienced by heart failure patients, patients with COPD, and other patients suffering from prolonged, unexplained fatigue.