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

超出所提供的空间。触觉异常性疼痛的特征在于通常无害的皮肤刺激变得异常非常疼痛，并且通常可以与周围神经损伤相关联地发生。这部分归因于伤害性C-纤维突触的丧失，伴随着机械感受性Ag-纤维进入脊髓板层II的出芽和突触发生。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家族，其与发育过程中CNS其他部分的突触形成、靶向和可塑性密切相关。在这里，我们研究的假设，钙粘蛋白的定位和功能的调节是一个关键的分子组成部分的脊髓内发芽和突触重组诱导坐骨神经损伤的成年大鼠。初步研究表明，多种经典钙粘蛋白在脊髓中表达;在脊髓层和细胞类型中差异分布;并且大多数位于突触中。为了扩展这一点，在目标1中，经典钙粘蛋白的正常细胞和突触分布的特点是结合原位杂交，免疫细胞化学和联合免疫荧光定位的钙粘蛋白选择性标记的突触终止的AB和C-纤维在背角。共聚焦显微镜将用于确定哪种经典钙粘蛋白与AB纤维和C纤维突触相关。目的2将测试的假设，在钙粘蛋白mRNA表达的变化和钙粘蛋白的新形成的突触的招聘是损伤诱导的可塑性的背角电路的分子机制的一个组成部分。将成年大鼠进行坐骨神经挤压，并将半定量RT-PCR和免疫印迹、原位杂交、免疫细胞化学和银纤维直接标记的组合用于阐明脊髓和DRG神经元响应于损伤的钙粘蛋白mRNA和蛋白表达水平的变化，这种变化的时间过程，以及在由出芽的AB轴突形成的异常突触处存在的钙粘蛋白的身份。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诱导的成人脊髓轴突发芽和新突触形成的分子事件。这里的工作将有助于了解如何防止这种适应不良的可塑性，可能是触觉异常的基础。 西奈山医学院（Mount Sinai School of Medicine Box 1065，Neurobiology 1425麦迪逊大街）。纽约，NY 10029-6574钥匙人员=