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===========================================

超过提供的空间。触觉异常性症的特征是通常无毒性的皮肤刺激，异常痛苦，并且通常与周围神经损伤有关。它部分归因于伤害性C纤维突触的丧失，而机械感应性Ag纤维的同时发芽和突触发生在脊柱层层II中。我们的长期目标是表征损伤后成熟脊髓中轴突发芽，靶细胞识别和突触形成的分子机制。经典的钙粘蛋白是一个富含突触的细胞粘附分子的家族，在发育过程中在中枢神经系统的其他部分中与突触形成，靶向和可塑性密切相关。在这里，我们研究了以下假设：调节钙粘蛋白的定位和功能是成年大鼠坐骨神经损伤引起的主要分子发芽和突触重组的关键分子成分。最初的研究表明，多种经典的钙粘蛋白在脊髓中表达。差异分布在脊柱和细胞类型之间；并且大多是突触本地化的。为了扩展这一点，在AIM 1中，经典钙粘蛋白的正常细胞和突触分布的特征在于原位杂交，免疫细胞化学化学和钙粘蛋白的免疫荧光定位与cadherins的免疫荧光定位，以选择性地标记为背侧角中AB和C纤维的突触终止。共聚焦显微镜将用于确定哪种经典的钙粘蛋白与AB纤维和C纤维突触相关。 AIM 2将检验以下假设：钙粘蛋白mRNA表达的变化和钙粘蛋白蛋白募集到新形成的突触是损伤诱导的背角回路可塑性的分子机制的组成部分。 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）存在于由发芽的AB轴突形成的异常突触。这些研究将揭示钙粘蛋白粘附分子如何参与轴突发芽和新的突触形成的分子事件，并在周围神经损伤引起的成年脊髓中形成。这里的工作将有助于理解如何防止触觉的这种不良适应性可塑性。 PerformancSeite（S）（S）（组织，ITY，State）Sinai Mount Medicine Box 1065，Neurobiology，Neurobiology 1425 Madison Ave.纽约，纽约，纽约，纽约，10029-6574 Kepersonnels =========================================================================== end ========================================