Functional analysis of erbB2 signaling in myelin-forming glial cells

髓鞘形成神经胶质细胞中 erbB2 信号的功能分析

• 批准号: 7523849
• 负责人: HAESUN A KIM
• 金额: $ 26.01万
• 依托单位: RUTGERS THE STATE UNIV OF NJ NEWARK
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-07-01 至 2012-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7523849
• 关键词: 1-Phosphatidylinositol 3-Kinase; Address; Adult; Axon; Behavioral; Binding; Biochemical; Charcot-Marie-Tooth Disease; Chemotherapy-Oncologic Procedure; Coculture Techniques; Complex; Cytoplasmic Tail; Demyelinating Diseases; Demyelinations; Development; Diabetes Mellitus; Diagnostic tests; Dimerization; Distal; Dominant-Negative Mutation; Endocytosis; Genetic; Goals; Hand; Homo; Image; Image Analysis; In Vitro; Injury; Leprosy; Ligand Binding; Ligands; Link; MAP Kinase Gene; Mediating; Molecular; Monitor; Myelin; Nerve; Nerve Degeneration; Neuraxis; Neuregulin 1; Neurodegenerative Disorders; Neuroglia; Neurons; Neuropathy; Pathologic; Pathway interactions; Peripheral Nerves; Peripheral Nervous System; Phosphoinositide-3-Kinase, Catalytic, Gamma Polypeptide; Play; Prevention; Process; Public Health; Publishing; Range; Ras/Raf; Receptor Activation; Receptor Protein-Tyrosine Kinases; Receptor Signaling; Regenerative Medicine; Research; Role; Schwann Cells; Secondary to; Signal Pathway; Signal Transduction; Staging; Syndrome; System; Testing; Therapeutic; cell behavior; cell type; gain of function; gene repression; gene therapy; in vitro Model; in vivo; inhibitor/antagonist; innovation; loss of function; motor deficit; mutant; myelination; nerve injury; receptor; receptor function; repaired; response; response to injury; sciatic nerve; therapy development; tool; trafficking

DESCRIPTION (provided by applicant): The long-term objective of this research is to define molecular mechanisms that are involved in demyelination and re-myelination of the peripheral nervous system (PNS). Demyelination is linked to the loss of all or part of neuronal functions because of the intimate connection between myelinating glial cells and axons. Therefore, the prevention of demyelination or promoting re-myelination is an important therapeutic objective for neurodegenerative diseases of the PNS and the CNS. We and others have shown recently that a function of receptor tyrosine kinase, erbB2, is associated with triggering PNS demyelination. ErbB2 function is also involved in promoting PNS myelination. The mechanisms by which erbB2 elicits two opposing roles in the PNS is unknown. Understanding the receptor signaling mechanisms has important implications for prevention of demyelinating neurodegenerative diseases and regenerative medicines. The broad goal of the present study is to define erbB2 function in initiating injury-induced PNS demyelination. Three specific aims are proposed: 1) determine the mechanism by which erbB2 promotes PNS demyelination, 2) determine whether erbB2 activation is sufficient to induce PNS demyelination and 3) determine the mechanism of signal transduction that is associated with the demyelinating function of erbB2. The study plan exploits a new in vitro compartmentalized Schwann cell-neuron co-culture system that recapitulates Schwann cell nerve injury responses in vivo. The system serves as a powerful tool for studying signal transduction using both pharmacological and genetic intervention. To investigate erbB2 function (Aim 1), we will use an adenoviral delivery system to express dominant-negative erbB2 mutant in adult myelinating Schwann cells, during different stages of PNS demyelination, which will enable us to achieve a conditional erbB2 inhibition both in vivo and in vitro. For the erbB2 gain-of-function study in Aim 2, we will use an innovative regulated erbB2 homo- and hetero-dimerization system. This system allows us to generate ectopic erbB2 signaling within myelinating Schwann cells, independent of the endogenous receptor and the ligand. For the signaling function raised in Aim 3, we will use both biochemical and imaging approaches to define erbB2-signaling mechanism that is associated with the demyelinating function of the receptor. PUBLIC HEALTH RELEVANCE Demyelination is a common pathologic feature in many PNS neurodegenerative diseases including Charcot-Marie-Tooth syndrome, Guillian-Barre syndrome, neuropathies secondary to diabetes and cancer chemotherapy, infectious neuropathy and motor deficits related to glial injury. Demyelination is also linked to the loss of all or part of neuronal functions because of the intimate connection between myelinating glial cells and the axons. Therefore, the prevention of demyelination is an important therapeutic objective for neurodegenerative diseases of the PNS and the CNS. Recent studies suggest that erbB2 activation might play a role in mediating PNS demyelination. Therefore, aberrant activation of the receptor or the associated cytoplasmic effectors may underlie a wide range of demyelinating disorders. Understanding the signal mechanism that initiates demyelination may have implications for the development of therapies that block erbB2 activation or diagnostic tests for detecting early demyelination before further progression of neurodegeneration.

描述（由申请人提供）：本研究的长期目标是确定参与周围神经系统（PNS）脱髓鞘和再髓鞘形成的分子机制。由于髓鞘胶质细胞与轴突之间的密切联系，脱髓鞘与神经元功能的全部或部分丧失有关。因此，预防脱髓鞘或促进再髓鞘形成是PNS和CNS神经退行性疾病的重要治疗目标。我们和其他人最近已经表明，受体酪氨酸激酶erbB2的功能与触发PNS脱髓鞘有关。ErbB2功能也参与促进PNS髓鞘形成。erbB2在PNS中引发两种相反作用的机制尚不清楚。了解受体信号传导机制对预防脱髓鞘性神经退行性疾病和再生药物具有重要意义。本研究的主要目的是确定erbB2在启动损伤诱导的PNS脱髓鞘中的功能。我们提出了三个具体目的：1)确定erbB2促进PNS脱髓鞘的机制，2)确定erbB2激活是否足以诱导PNS脱髓鞘，3)确定与erbB2脱髓鞘功能相关的信号转导机制。该研究计划利用一种新的体外区隔化雪旺细胞-神经元共培养系统，再现体内雪旺细胞神经损伤反应。该系统可作为研究信号转导的有力工具，使用药理学和遗传干预。为了研究erbB2的功能（目的1），我们将使用腺病毒传递系统，在PNS脱髓鞘的不同阶段，在成年髓鞘雪旺细胞中表达显性阴性erbB2突变体，这将使我们能够在体内和体外实现条件erbB2抑制。在Aim 2的erbB2功能获得研究中，我们将使用一种创新的调节erbB2同源和异源二聚化系统。该系统允许我们在髓鞘雪旺细胞内产生异位erbB2信号，独立于内源性受体和配体。对于Aim 3中提出的信号功能，我们将使用生化和成像方法来定义与受体脱髓鞘功能相关的erbb2信号机制。脱髓鞘是许多PNS神经退行性疾病的常见病理特征，包括charco - marie - tooth综合征、Guillian-Barre综合征、继发于糖尿病和癌症化疗的神经病变、感染性神经病变和与神经胶质损伤相关的运动缺陷。由于髓鞘胶质细胞与轴突之间的密切联系，脱髓鞘也与全部或部分神经元功能的丧失有关。因此，预防脱髓鞘是PNS和CNS神经退行性疾病的重要治疗目标。最近的研究表明erbB2的激活可能在PNS脱髓鞘中起作用。因此，受体或相关的细胞质效应物的异常激活可能是多种脱髓鞘疾病的基础。了解引发脱髓鞘的信号机制可能对开发阻断erbB2激活的治疗方法或在神经退行性疾病进一步发展之前检测早期脱髓鞘的诊断测试具有重要意义。