Calcineurin and Neuropathic Pain

钙调神经磷酸酶和神经性疼痛

• 批准号: 8413040
• 负责人: VJEKOSLAV MILETIC
• 金额: $ 31.77万
• 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 2017-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8413040
• 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; 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

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.

项目摘要/摘要 钙调神经酶（蛋白质磷酸酶3，先前蛋白质磷酸酶2B）扮演着关键 在调节大脑中依赖活性的突触可塑性方面的作用。发展的发展 神经性疼痛似乎取决于某些基础的机制 大脑突触可塑性。在阐明其中一些方面取得了很多进展 机制但我们的知识中存在许多差距。结果神经性疼痛 继续接受不足的治疗。在此应用程序中，我们希望填写其中一些 当我们寻求阐明钙调神经酶是否在调节损伤引诱中起作用时，空白 脊柱背喇叭中的可塑性。 我们的初步数据显示，在 动物脊髓背角神经元的同侧后突触后密度（PSD） 在慢性狭窄损伤（CCI）之后表现出神经性疼痛行为 坐骨神经或脊髓结扎（SNL）。 CCI后的疼痛行为减弱 通过鞘内注射外源性钙调蛋白。鞘内应用 钙调神经蛋白抑制剂FK-506在对照中引起疼痛行为，未受伤的动物。这些 数据表明钙调神经酶和神经性疼痛之间有联系，但仍然存在 尚不清楚PSD中磷酸酶的丧失如何影响 神经性疼痛。在此应用中，我们假设至少三个负面后果 钙调神经素的损失。由A激酶锚定蛋白形成的复合物的破坏 （AKAP），蛋白激酶A（PKA）和钙调神经酶（AIM 1）。持续的磷酸化和 在PSD膜中插入AMPA受体（AIM 2）。磷酸化 - AMPA，NMDA和代谢型谷氨酸受体的依赖性物理联系 （mglur）通过建立或加强联系的家庭 脚手架蛋白PSD-95，Shank和Homer（AIM 3）。 另外，在大脑中，海马突触允许的钙调神经酶活性丧失 从短期到长期记忆的过渡。很容易假设 过渡到神经性疼痛是PSD失去钙调蛋白的结果 脊柱背角神经元（AIM 4）。 PSD中的钙调蛋白活性可能严重限制高频传入活性 通过引起长期可塑性，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 部分是由于脊柱中钙调蛋白介导的去磷酸化的丧失 背角。没有去磷酸化以防止对PSD进行重塑 有利的突触增强只有夸张的唤起反应才会由 主要传入活动。这种增强的感觉输入表现为神经性 疼痛。 总体而言，我们努力实现两个目标。从蜂窝的角度来看，我们希望描绘 神经损伤对脊柱背角PSD蛋白质基质的后果 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。