AKAP MODULATES TRPV1 PHOSPHORYLATION AND SENSITIZATION

描述（由申请人提供）：神经元可塑性是记忆、运动和疼痛等多种功能中普遍存在的一个普遍特征。因此，对可塑性机制的基础研究有可能对高医学和科学影响的关键问题做出深远的贡献，特别是在外周疼痛的研究中。尽管疼痛障碍给社会和卫生保健系统带来了巨大的经济负担，但由于持续的外周疼痛，生活质量的损失是无法估量的。在这个应用中，我们通过关注主要传入神经元水平上的活动依赖性变化来解决这个问题，这些变化发生在对各种类型的损伤（包括慢性、神经性和炎症）的反应中。外周可塑性，即外周传入末端蛋白质的修饰/调节，强调了从正常的神经元信号通路到持续疼痛状态的超敏感、伤害性信号传导器的转变。最近，对伤害性信号传导的研究包括对受体通道的检查以及控制受体通道活性的调节生化和细胞机制。瞬时受体电位（TRP）受体通道TRPV1家族是研究外周疼痛感知的主要成员，因为它已被广泛研究，并在传递疼痛刺激（伤害感受器）的无髓鞘c型神经元亚群上表达。TRPV1在损伤反应中的翻译后修饰，包括磷酸化，显著改变通道活性，从而影响系统的可塑性。最近，我们已经证明某些TRPV1磷酸化事件在功能上依赖于支架蛋白a激酶锚定蛋白（AKAP）。最初，AKAP被描述为仅介导底物的蛋白激酶A （PKA）磷酸化，尽管最近的证据表明AKAP也与PKC相关并指导其信号通路。在这个应用中，我们提出验证AKAP组织TRPV1翻译后磷酸化的主要假设。为了实现这一目标，我们将首先评估AKAP150与蛋白激酶C （PKC）关联的改变是否会导致TRPV1磷酸化的改变和TRPV1通道活性的敏化。其次，我们将评估PKC的受体激活是否需要AKAP150来改变TRPV1磷酸化和TRPV1通道活性的敏化。第三，我们将在体内确定AKAP150是否通过PKA和PKC调节TRPV1的活性。我们的假设的验证将激发未来的努力，研究如何在临床相关情况下选择性地控制akap组织的TRPV1磷酸化修饰，以减轻外周疼痛。与公共卫生相关对神经元可塑性机制的基础研究对疼痛研究中具有高度医学和科学影响的关键问题具有深远贡献的潜力。尽管疼痛障碍给社会和卫生保健系统带来了巨大的经济负担，但由于持续疼痛而导致的不可估量的生活质量损失取代了这一负担。在本应用中，我们通过确定支架蛋白AKAP在调节外周痛觉神经元敏化中的作用来解决这个问题，从而激发抑制疼痛的新药的产生。

DESCRIPTION (provided by applicant): Neuronal plasticity is a general feature prevalent among functions as diverse as memory, movement, and pain. Therefore, fundamental research into mechanisms of plasticity has the potential for profound contributions to key questions of high medical and scientific impact, especially in the study of peripheral pain. Although pain disorders carry a large financial burden to society and the health care system, this is superseded by an incalculable loss in quality of life due to persistent peripheral pain. In this application, we address this issue by focusing on activity-dependent changes at the level of the primary afferent neuron that occur in response to various types of injury, including chronic, neuropathic and inflammatory. Peripheral plasticity, the modification/ modulation of proteins present at peripheral afferent terminals, highlights the transition from normal, neuronal signaling pathways into hypersensitive, nociceptive transducers of persistent, painful states. Recently, the study of nociceptive signaling has included the examination of receptor-channels and the modulatory biochemical and cellular mechanisms that control receptor-channel activity. The TRPV1 family of Transient Receptor Potential (TRP) receptor-channels serves as a principal member for the study of peripheral pain perception, as it has been examined extensively and is expressed on a subset of non-myelinated, C-type neurons that transmit painful stimuli (nociceptors). Post- translational modifications of TRPV1 in response to injury, including phosphorylation, significantly alter channel activity, and thereby affect the plasticity of the system. Recently, we have demonstrated that certain TRPV1 phosphorylation events are functionally dependent upon the scaffolding protein A-Kinase Anchoring Protein (AKAP). Initially, AKAP was characterized as solely mediating Protein Kinase A (PKA) phosphorylation of substrates, although recent evidence indicates that AKAP also associates with PKC and directs its signaling pathway as well. In this application, we propose to test the primary hypothesis that AKAP organizes the post- translational phosphorylation of TRPV1. To accomplish this, we will first evaluate whether alterations in AKAP150 association with Protein Kinase C (PKC) leads to alterations in TRPV1 phosphorylation and sensitization of TRPV1 channel activity. Second, we will evaluate whether receptor-activation of PKC requires AKAP150 to alter TRPV1 phosphorylation and sensitization of TRPV1 channel activity. Thirdly, we will determine whether AKAP150 modulates TRPV1 activity via PKA and PKC in vivo. Validation of our hypothesis will stimulate future endeavors to investigate how AKAP-organized modifications of TRPV1 phosphorylation by PKA can be selectively controlled in clinically relevant situations to relieve peripheral pain. PUBLIC HEALTH RELEVACNE Fundamental research into mechanisms of neuronal plasticity has the potential for profound contributions to key questions of high medical and scientific impact in the study of pain. Although pain disorders carry a large financial burden to society and the health care system, this is superseded by an incalculable loss in quality of life due to persistent pain. In this application, we address this issue by determining the role of the scaffolding protein AKAP in modulating the sensitization of pain-sensing neurons in the periphery, to inspire the generation of new drugs that will inhibit pain.