Calcineurin and Neuropathic Pain

钙调神经磷酸酶和神经性疼痛

• 批准号: 8790776
• 负责人: VJEKOSLAV MILETIC
• 金额: $ 32.92万
• 依托单位: UNIVERSITY OF WISCONSIN-MADISON
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-02-01 至 2016-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8790776
• 关键词: A kinase anchoring protein; AMPA Receptors; Acute; Analgesics; Animals; Attenuated; Biological; Brain; Calcineurin; Calcineurin inhibitor; Complex; Cyclic AMP-Dependent Protein Kinases; Data; Development; Exhibits; Family; Frequencies; Goals; Hippocampus (Brain); Inflammation; Injury; Intrathecal Injections; Ipsilateral; Knowledge; Lead; Ligation; Link; Mediating; Membrane; Metabotropic Glutamate Receptors; N-Methylaspartate; Peripheral nerve injury; Persistent pain; Phosphoric Monoester Hydrolases; Phosphorylation; Play; Posterior Horn Cells; Protein Dephosphorylation; Protein phosphatase; Proteins; Role; Scaffolding Protein; Sensory Process; Specificity; Spinal; Spinal nerve structure; Synapses; Synaptic plasticity; Therapeutic; abstracting; chronic constriction injury; density; dorsal horn; long term memory; nerve injury; novel; pain behavior; painful neuropathy; prevent; response; sciatic nerve; sensory input

Project Summary/Abstract Calcineurin (protein phosphatase 3, previously protein phosphatase 2B) plays a pivotal role in regulating activity-dependent synaptic plasticity in the brain. The development of neuropathic pain appears dependent upon some of the same mechanisms that underlie brain synaptic plasticity. Much progress has been made in elucidating some of these mechanisms but many gaps in our knowledge remain. As a result neuropathic pain continues to be inadequately treated. In this application we wish to fill in some of these gaps as we seek to elucidate whether calcineurin plays a role in regulating injury-elicited plasticity in the spinal dorsal horn. Our preliminary data revealed significantly lower calcineurin activity and content in the ipsilateral post-synaptic density (PSD) of spinal dorsal horn neurons in animals exhibiting neuropathic pain behavior following chronic constriction injury (CCI) of the sciatic nerve or spinal nerve ligation (SNL). The pain behavior after CCI was attenuated by an intrathecal injection of exogenous calcineurin. An intrathecal application of the calcineurin inhibitor FK-506 elicited pain behavior in control, uninjured animals. These data suggested a connection between calcineurin and neuropathic pain but it remains unclear how the loss of the phosphatase in the PSD may influence the development of neuropathic pain. In this application we postulate at least three negative consequences of calcineurin's loss. Disruption of a complex formed by the A kinase anchoring protein (AKAP), protein kinase A (PKA) and calcineurin (Aim 1). Persistent phosphorylation and insertion of AMPA receptors in the PSD membrane (Aim 2). Phosphorylation- dependent physical linking of AMPA, NMDA and metabotropic glutamate receptor (mGluR) families through the establishment or enhancement of links between the scaffolding proteins PSD-95, Shank and Homer (Aim 3). In addition, in the brain a loss of calcineurin activity at hippocampal synapses permits the transition from short to long-term memory. It is tempting to hypothesize that the transition to neuropathic pain is a consequence of the loss of calcineurin from the PSD of spinal dorsal horn neurons (Aim 4). Calcineurin activity in the PSD may critically constrain high-frequency afferent activity from eliciting long-lasting plasticity because the latter may signify the development of neuropathic pain. In other words, nerve injury may give rise to neuropathic pain at least in part as a result of the loss of calcineurin-mediated dephosphorylation in the spinal dorsal horn. With no dephosphorylation to prevent a remodeling of the PSD which favors synaptic enhancement only exaggerated evoked responses would be elicited by primary afferent activity. This enhanced sensory input manifests then as neuropathic pain. Overall we strive to achieve two goals. From a cellular perspective we wish to delineate the consequences of nerve injury on the protein matrix of the PSD in spinal dorsal horn neurons. From a therapeutic perspective we seek better target specificity for more effective analgesic treatments.

项目概要/摘要 钙调神经磷酸酶（蛋白磷酸酶 3，以前的蛋白磷酸酶 2B）发挥着关键作用 调节大脑活动依赖性突触可塑性的作用。的发展 神经性疼痛似乎依赖于某些相同的机制 大脑突触可塑性。在阐明其中一些方面已经取得了很大进展 但我们的知识仍然存在许多差距。结果是神经性疼痛 仍然没有得到充分的治疗。在此应用程序中，我们希望填写其中一些 当我们试图阐明钙调神经磷酸酶是否在调节损伤引起的过程中发挥作用时，存在差距 脊髓背角的可塑性。 我们的初步数据显示，钙调磷酸酶活性和含量显着降低 动物脊髓背角神经元的同侧突触后密度（PSD） 慢性压迫性损伤（CCI）后表现出神经性疼痛行为 坐骨神经或脊神经结扎（SNL）。 CCI后疼痛行为减弱 通过鞘内注射外源性钙调神经磷酸酶。鞘内应用 钙调神经磷酸酶抑制剂 FK-506 在未受伤的对照动物中引发疼痛行为。这些 数据表明钙调神经磷酸酶和神经性疼痛之间存在联系，但这种联系仍然存在 目前尚不清楚 PSD 中磷酸酶的缺失如何影响 PSD 的发展 神经性疼痛。在此应用中，我们假设至少三个负面后果 钙调神经磷酸酶的损失。 A 激酶锚定蛋白形成的复合物的破坏 (AKAP)、蛋白激酶 A (PKA) 和钙调神经磷酸酶（目标 1）。持续磷酸化和 将 AMPA 受体插入 PSD 膜（目标 2）。磷酸化- AMPA、NMDA 和代谢型谷氨酸受体的依赖物理连接 (mGluR) 家族通过建立或增强之间的联系 支架蛋白 PSD-95、Shank 和 Homer（目标 3）。 此外，在大脑中，海马突触钙调神经磷酸酶活性的丧失使得 从短期记忆到长期记忆的转变。人们很容易假设 转变为神经性疼痛是 PSD 中钙调神经磷酸酶丢失的结果 脊髓背角神经元（目标 4）。 PSD 中的钙调神经磷酸酶活性可能严重限制高频传入活动 避免引发持久的可塑性，因为后者可能意味着 神经性疼痛。换句话说，神经损伤至少可能引起神经性疼痛 部分原因是脊髓中钙调神经磷酸酶介导的去磷酸化作用丧失 背角。没有去磷酸化来防止 PSD 重塑， 有利于突触增强，只有夸大的诱发反应才会被引发 初级传入活动。这种增强的感觉输入表现为神经病性 疼痛。 总的来说，我们努力实现两个目标。我们希望从细胞的角度描绘 神经损伤对脊髓背角PSD蛋白基质的影响 神经元。从治疗的角度来看，我们寻求更好的目标特异性 有效的镇痛治疗。