Molecular mechanisms of store-operated calcium channels in pain

描述(申请人提供)：慢性疼痛仍然是一个主要的公共卫生问题，相当大的努力旨在更好地了解潜在的机制，以促进更有效和更安全的治疗方法的开发。我实验室的研究重点是商店操作的钙通道(SOCC)在疼痛调制中的作用。SOC通道由新近发现的Orai亚基(Orai1/2/3，造孔亚基)和基质相互作用分子(STIM)1和STIM2(内质网钙感受器，作为它们的激活剂)组成。通过内质网(ER)释放钙激活SOCCs，导致胞内持续高水平的钙离子，这是许多钙依赖的细胞过程所必需的。在中枢神经系统(CNS)中，SOC通道影响神经递质的释放和突触的可塑性。我们目前的R21资助结果表明，SOCC在背角神经元中有功能表达，其药理性质与不可兴奋细胞中的相似。我们已经确定STIM1和Orai1是背角神经元SOCCs的重要组成部分，并证明了STIM1和Orai1蛋白的敲除分别减少了备用神经损伤(SNI)诱导的神经病理性疼痛。最近，我们发现SOC抑制剂YM-58483不仅可以减轻神经病理性疼痛，还可以显著减轻炎症性疼痛。有趣的是，SOCC抑制剂在以后的时间点阻断了NMDA和mGluR1/5激动剂诱导的持续钙内流和伤害性行为，这表明SOCC参与了NMDA受体和mGluR1/5的功能。基于这些发现，我们假设SOCC参与疼痛是通过它们与NMDA受体和mGluR1/5的相互作用。为了验证这一假说，我们将结合膜片钳记录、钙成像记录、Western Blot分析和行为测试的方法。总体而言，我们的长期目标是了解慢性疼痛的机制。这项建议的目标是确定SOCC信号的内源性上游分子，并探索SOCC激活的功能后果。这些研究将扩大我们对SOCC信号如何调节疼痛的了解。我们的发现将在SOCC和I组mGluR之间以及SOCC和NMDA受体之间建立功能联系。这些研究将为疼痛和其他中枢神经系统疾病的机制提供新的见解，并可能为治疗干预提供新的方法。

DESCRIPTION (provided by applicant): Chronic pain continues to be a major public health concern with considerable effort directed towards achieving a better understanding of the underlying mechanisms to facilitate the development of more effective and safer therapeutics. The research in my lab focuses on the role of store-operated calcium channels (SOCCs) in the modulation of pain. SOC channels are composed of recently discovered Orai subunits (Orai1/2/3, pore-forming subunits), and stromal interaction molecules (STIM) 1 and STIM2 (the ER Ca2+ sensors, serve as their activators). Activation of SOCCs by the release of calcium from endoplasmic reticulum (ER) leads to sustained high levels of cytosolic Ca2+ that are required for many calcium-dependent cellular processes. In the central nervous system (CNS), SOC channels are known to influence neurotransmitter release and synaptic plasticity. Results from our current R21 grant have demonstrated that SOCCs are functionally expressed in dorsal horn neurons and their pharmacological properties are similar to those in non-excitable cells. We have identified STIM1 and Orai1 as essential components of SOCCs in dorsal horn neurons and have demonstrated that the knockdown of STIM1 and Orai1 proteins individually reduces spare nerve injury (SNI)-induced neuropathic pain. Recently, we found that the SOC inhibitor YM- 58483 not only attenuates neuropathic pain, but also dramatically diminishes inflammatory pain. Of interest is the finding that a SOCC inhibitor blocks NMDA and mGluR1/5 agonist- induced sustained calcium entry and nociceptive behavior at later time points, suggesting that SOCCs are involved in functions of NMDA receptors and mGluR1/5. Based on these findings, we hypothesize that SOCC involvement in pain is mediated by their interaction with NMDA receptors and mGluR1/5. To test this hypothesis, we will combine the methods of patch-clamp recording, calcium imaging recording, Western Blot analysis and behavioral testing. Overall, our long-term goal is to understand the mechanisms of chronic pain. The goals of this proposal are to identify endogenous upstream molecules of SOCC signaling and explore functional consequences of SOCC activation. These studies will extend our knowledge of how the SOCC signaling modulates pain. Our findings will establish functional links between SOCCs and group I mGluR, and between SOCCs and NMDA receptors. These studies will provide novel insights into mechanisms of pain and other CNS disorders and may suggest new approaches to therapeutic intervention.