Cadherin adhesion proteins in spinal cord plasticity

脊髓可塑性中的钙粘蛋白粘附蛋白

• 批准号: 6819985
• 负责人: GEORGE W. HUNTLEY
• 金额: $ 24.15万
• 依托单位: ICAHN SCHOOL OF MEDICINE AT MOUNT SINAI
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-12-15 至 2006-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6819985
• 关键词: Cadherin; adhesion; proteins; spinal; cord

EXCEEDTHE SPACE PROVIDED. Tactile allodynia is characterized by normally non-noxious cutaneous stimuli that become abnormally very painful, and can often occur in association with peripheral nerve injury. It has been attributed partly to loss of nociceptive C-fiber synapses with concommitant sprouting and synaptogenesis of mechanoreceptive Ag-fibers into spinal lamina II. Our long-term goal is to characterize molecular mechanisms of axon sprouting, target cell recognition and synapse formation in mature spinal cord following injury. The classic cadherins are a family of synaptically-enriched cell adhesion molecules which have been strongly linked to synapse formation, targeting and plasticity in other parts of the CNS during development. Here, we examine the hypothesis that regulation of cadherin localization and function is a critical molecular component of intraspinal sprouting and synaptic reorganization induced by sciatic nerve injury in adult rats. Initial studies demonstrate multiple classic cadherins are expressed in spinal cord; are differentially distributed across spinal layers and cell types; and are mostly synaptically localized. To extend this, in Aim 1, the normal cellular and synaptic distribution of classic cadherins will be characterized by a combination of in situ hybridization, immunocytochemistry and combined immunofluorescent localization of cadherins to selectively labeled synaptic terminations of AB- and C-fibers in dorsal horn. Confocal microscopy will be used to determine which classic cadherin (s) associate with AB-fiber and C-fiber synapses. Aim 2 will test the hypothesis that changes in cadherin mRNA expression and recruitment of cadherin protein to newly formed synapses is a component of the molecular mechanisms of injury-induced plasticity of dorsal horn circuitry. Adult rats will be subjected to sciatic nerve crush, and a combination of semi-quantitative RT-PCR and immunoblotting, in situ hybridization, immunocytochemistry, and direct labeling of Ag-fibers will be used to elucidate changes in cadherin mRNA and protein levels of expression by spinal cord and DRG neurons in response to injury, the time-course of such changes, and the identity of the cadherin(s) present at the aberrant synapses formed by sprouted AB axons. These studies will reveal how cadherin adhesion molecules participate in the molecular events that underlie axon sprouting and new synapse formation in the adult spinal cord induced by peripheral nerve injury. The work here will contribute to an understanding of how to prevent such maladaptive plasticity of the kind which may underlie tactile allodvnia. PERFORMANCSEITE(S)(organizationc,ity,state) The Mount Sinai School of Medicine Box 1065, Neurobiology 1425 Madison Ave. New York, NY 10029-6574 KEYPERSONNELS ========================================Section End===========================================

超出提供的空间。触觉异常性疼痛的特征是通常无害的皮肤刺激变得异常非常疼痛，并且通常与周围神经损伤有关。其部分原因在于伤害感受性 C 纤维突触的丧失，同时机械感受性 Ag 纤维的发芽和突触发生进入椎板 II。我们的长期目标是表征损伤后成熟脊髓中轴突萌发、靶细胞识别和突触形成的分子机制。经典的钙粘蛋白是突触富集的细胞粘附分子家族，在发育过程中与中枢神经系统其他部分的突触形成、靶向和可塑性密切相关。在这里，我们研究了这样的假设：钙粘蛋白定位和功能的调节是成年大鼠坐骨神经损伤诱导的椎内出芽和突触重组的关键分子组成部分。初步研究表明多种经典钙粘蛋白在脊髓中表达。不同的脊髓层和细胞类型分布；并且大多是突触局部化的。为了扩展这一目标，在目标 1 中，经典钙粘蛋白的正常细胞和突触分布将通过结合原位杂交、免疫细胞化学和钙粘蛋白的联合免疫荧光定位到背角中 AB 纤维和 C 纤维的选择性标记突触末端来表征。 。共聚焦显微镜将用于确定哪些经典钙粘蛋白与 AB 纤维和 C 纤维突触相关。目标 2 将检验以下假设：钙粘蛋白 mRNA 表达的变化和钙粘蛋白向新形成的突触的募集是损伤诱导的背角电路可塑性分子机制的一个组成部分。成年大鼠将受到坐骨神经挤压，并结合半定量 RT-PCR 和免疫印迹、原位杂交、免疫细胞化学和 Ag 纤维直接标记来阐明钙粘蛋白 mRNA 和蛋白表达水平的变化脊髓和 DRG 神经元对损伤的反应、这些变化的时间过程以及由发芽的 AB 形成的异常突触中存在的钙粘蛋白的身份轴突。这些研究将揭示钙粘蛋白粘附分子如何参与周围神经损伤引起的成人脊髓中轴突萌发和新突触形成的分子事件。这里的工作将有助于理解如何防止这种可能构成触觉异常的适应不良可塑性。 PERFORMANCSEITE(S)(organizationc,ity,state) The Mount Sinai School of Medicine Box 1065, Neurobiology 1425 Madison Ave. New York, NY 10029-6574 关键人员 ================= =======================章节结束========================= =================