Purinergic G protein signal integration in nociceptors

描述（由申请人提供）：慢性疼痛每年影响超过5000万美国人，导致个人和社会在生活质量下降，生产力下降和医疗保健消费方面付出巨大代价。改善急性和慢性疼痛条件的治疗需要对疼痛刺激的传输和感知的潜在过程有透彻的了解。发现急性和慢性疼痛的分子和细胞机制对开发新的治疗方法至关重要，特别是在从急性到慢性疼痛过渡的调节机制方面。我们实验室最近的研究已经确定了一种内源性镇痛机制，该机制存在于传递疼痛的外周感觉神经元中，由G蛋白偶联受体（gpcr）介导二磷酸腺苷（ADP）。本项目将研究通过Gi/o信号传导的ADP受体在炎症损伤引起的痛觉过敏中的作用，以及GPCR激酶GRK2和GRK3在痛觉过敏过程中对P2Y信号的调节，并探索这些受体在改善由腺苷酸环化酶介导的痛觉过敏中非常有效的假设，腺苷酸环化酶是炎症性疼痛的基本成分。特异性目的1将在体外研究GRK2和GRK3在背根神经节（DRG）神经元中的分布及其对P2Y信号的调控。特异性目的2将确定GRK2和GRK3是否在炎症损伤的情况下共同调节，并将通过体外实时cAMP成像检查GRK信号改变对P2Y受体抑制腺苷酸环化酶的影响。特异性目的3将确定P2Y信号调节的变化在多大程度上有助于体内炎症性痛觉过敏的解决，以及是否操纵这些通路可能为治疗炎症性疼痛提供一种新的方法。本研究将探讨Gi/o偶联P2Y受体作为新型镇痛药物靶点的价值，并将促进我们对GPCR功能和外周神经系统伤害性加工的基本机制的理解。

DESCRIPTION (provided by applicant): Chronic pain affects more than 50 million Americans per year, resulting in extraordinary personal and societal costs in diminished quality of life, los productivity and health care consumption. Improved treatments of acute and chronic pain conditions require a thorough understanding of the processes underlying the transmission and perception of painful stimuli. Discovery of the molecular and cellular mechanisms underlying acute and chronic pain is critical to the development of new treatments, particularly in mechanisms regulating the transition from acute to chronic pain. Recent studies from our laboratory have identified an endogenous analgesic mechanism that is present in peripheral sensory neurons conveying pain and is mediated by G protein-coupled receptors (GPCRs) for adenosine diphosphate (ADP). This project will investigate the role of ADP receptors signaling through Gi/o in hyperalgesia resulting from inflammatory injury, the regulation of P2Y signaling by GPCR kinases GRK2 and GRK3 during hyperalgesia, and will explore the hypothesis that these receptors are highly effective in ameliorating hyperalgesia mediated by adenylyl cyclase, a fundamental component of inflammatory pain. Specific Aim 1 will investigate the distribution of GRK2 and GRK3 in dorsal root ganglion (DRG) neurons and their regulation of P2Y signaling in vitro. Specific Aim 2 will determine whether GRK2 and GRK3 are co-regulated in the setting of inflammatory injury, and will examine the impact of altered GRK signaling on P2Y receptor inhibition of adenylyl cyclase using real-time cAMP imaging in vitro. Specific Aim 3 will determine the extent to which changes in the regulation of P2Y signaling contribute to the resolution of inflammatory hyperalgesia in vivo and whether manipulation of these pathways may provide a novel approach to the treatment of inflammatory pain. This proposal will examine the value of Gi/o-coupled P2Y receptors as targets for novel analgesic drugs, and will advance our understanding of fundamental mechanisms regulating GPCR function and nociceptive processing in the peripheral nervous system.