Store-operated calcium channels in neuropathic pain

描述（由申请人提供）：神经性疼痛代表了执业医师的临床挑战，也是社会的巨大负担。虽然神经性疼痛的机制仍有待建立，钙渗透性离子通道和受体已涉及疼痛以及与慢性疼痛状态相关的神经可塑性。钙库操纵的钙通道（SOC）是一种高度钙选择性的阳离子通道，通过内质网释放和消耗钙来激活。SOC通道的激活导致许多钙依赖性细胞过程所需的持续的高细胞溶质Ca 2+水平。SOC通道由新发现的奥赖亚基（Orai 1/2/3，孔形成亚基）和非兴奋细胞中的基质相互作用分子（STIM）1和STIM 2（ER Ca 2+传感器，充当它们的激活剂）组成。在神经系统中，已知SOC通道影响神经递质释放和突触可塑性。STIM 2是缺血诱导的细胞内钙离子在神经元中积累所必需的，但SOC通道的基本性质和神经元中SOC通道的分子组成尚未被探索。最近，我们发现SOC通道在脊髓背角神经元中有功能性表达，并证实SOC通道的激活参与突触传递。这些观察结果提出的问题SOC通道的功能和耦合到这些通道的激活疼痛信号传递的信号通路的性质。我们还发现SOC通道的表达在备用神经损伤（SNI）后的不同时间点上调。基于这些发现，我们推测SOC通道可能在神经病理性疼痛中发挥作用。为了验证我们的假设，我们将结合联合收割机膜片钳记录、钙成像记录、Taqman实时荧光定量PCR和行为测试等方法。总的来说，我们的长期目标是确定参与慢性疼痛的关键分子靶点。本研究的目的是确定SOC通道的基本性质，鉴定编码背角神经元SOC通道的分子，并确定SOC通道家族在神经病理性疼痛中的作用。本研究的预期结果是识别疼痛通路中新的钙信号，以及神经病理性疼痛发生和维持的新机制。

DESCRIPTION (provided by applicant): Neuropathic pain represents a clinical challenge for the practicing physician and is a great burden to society. Although the mechanisms underlying neuropathic pain remain to be established, calcium-permeable ion channels and receptors have been implicated in pain as well as in the neuroplasticity associated with chronic pain states. Store-operated calcium (SOC) channels are highly Ca2+-selective cation channels that are activated by the release and depletion of calcium from the endoplasmic reticulum. Activation of SOC channels leads to sustained high cytosolic Ca2+ levels that are required for many calcium-dependent cellular processes. SOC channels are composed of newly 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) in non-excitable cells. In the nervous system, SOC channels are known to influence neurotransmitter release and synaptic plasticity. STIM2 is essential for ischemia-induced cytosolic Ca2+ accumulation in neurons, but the basic properties of SOC channels and molecular components underlying SOC channels in neurons are unexplored. Recently, we found that SOC channels are functionally expressed in spinal dorsal horn neurons and demonstrated that activation of SOC channels is involved in synaptic transmission. These observations raise questions as to the function of SOC channels and to the nature of the signaling pathways that are coupled to the activation of these channels in pain signal transmission. We also found that the expression of the SOC channels is upregulated at different time points after spare nerve injury (SNI). Based on these findings, we hypothesize that the SOC channels may play a role in neuronpathic pain. To test our hypothesis, we will combine the methods of patch-clamp recording, calcium imaging recording, Taqman real-time-PCR and behavioral testing. Overall, our long-term goal is to identify key molecular targets involved in chronic pain. The goals of this proposal are to determine basic properties of SOC channels, to identify molecules encoding SOC channels in dorsal horn neurons, and to determine the role of SOC channel family in neuropathic pain. The expected outcome of this research is the identification of new calcium signaling in pain pathway and a new mechanism underlying the development and maintenance of neuropathic pain.