TROPHIC FACTORS IN CHRONIC MOTOR NEURON DEGENERATION

慢性运动神经元变性中的营养因素

• 批准号: 2259826
• 负责人: ANDREA M CORSE
• 金额: $ 8.05万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-04-01 至 1999-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2259826
• 关键词: amyotrophic lateral sclerosis; cell growth regulation; cell sorting; choline acetyltransferase; cytotoxicity; enzyme activity; fibroblast growth factor; glutamates; growth factor receptors; immunocytochemistry; insulinlike growth factor; laboratory rat; migration inhibition factor; motor neurons; neural degeneration; neurogenesis; neuroprotectants; neurotransmitter receptor; neurotransmitter transport; neurotrophic factors; newborn animals; receptor expression; tissue /cell culture

The overall goal of our laboratory is to understand the mechanisms of selective vulnerability of motor neurons in amyotrophic lateral sclerosis (ALS) and to search for specific neuroprotective strategies applicable to motor neuron degenerations. The specific goal of this proposal is to determine whether (and by what mechanisms) recently engineered recombinant neurotrophic factors can be protective by (1) preserving the phenotype and survival of mature motor neurons, and (2) protecting them from experimentally induced chronic degeneration. Inevitably, much of the previous work identifying the role of neurotrophic factors in motor neuron survival has focused on models of the developing nervous system in which motor neurons undergo naturally occurring cell death (apoptosis). Few studies have actually considered the role of neurotrophic factors in postnatal motor neuron survival, when the process of naturally occurring motor neuron death is no longer applicable. The work outlined in this proposal will broaden our understanding of the effects of neurotrophic factors on motor neuron survival in the mature nervous system. Several such factors (CNTF, IGF) have already been rushed into clinical trials (some would say prematurely) for neurodegenerative diseases. This work will provide important preclinical data on the use of these factors as therapy in motor neuron diseases. A unique organotypic culture system has been developed in our laboratory for postnatal rat spinal cord. Because this preparation combines the advantages of long-term survival of mature motor neurons in culture with partially preserved synaptic connections, it is an ideal system in which to test whether neurotrophic factors can affect mature motor neuron survival or provide protection from degeneration. It simultaneously provides a way of determining any inherent toxicity of these growth factors, particularly those with cytokine like activity. The specific localization of choline acetyltransferase activity (ChAT) to large motor neurons in the ventral lumbar cord allows techniques for systematically assessing motor neuron viability. These include biochemical assay of ChAT activity and immunocytochemical staining of ChAT for morphologic analysis and cell counts. We also use the organotypic spinal cord cultures to provide a novel model of slow, glutamate-mediated motor neuron degeneration, a postulated mechanism of neurotoxicity in ALS. Long term incubation of spinal cord in the presence of threohydroxyaspartate, a potent glutamate transport inhibitor, reproduces relatively selective motor neuron degeneration. In this model, the neuroprotectant effects of the neurotrophic factors on motor neurons will be studied, providing further insight into the mechanisms of neurotrophic actions and potential pharmacologic strategies for therapies of motor neuron diseases such as ALS.

我们实验室的总体目标是了解 肌萎缩侧索硬化症运动神经元的选择性易损性 (ALS)并寻找适用于以下情况的特定神经保护策略： 运动神经元退化 该提案的具体目标是 确定是否（以及通过何种机制）最近工程重组 神经营养因子可以通过（1）保持表型和 成熟运动神经元的存活，以及（2）保护它们免受 实验性慢性变性 不可避免的是， 先前的工作确定了神经营养因子在运动神经元中的作用 生存集中在神经系统发育的模型上， 运动神经元经历自然发生的细胞死亡（凋亡）。 几 研究实际上已经考虑了神经营养因子在 出生后运动神经元的存活， 运动神经元死亡不再适用。 本报告概述的工作 这项提案将扩大我们对神经营养素的影响的理解， 影响成熟神经系统中运动神经元存活的因素。 几 这些因子（CNTF，IGF）已经被匆忙地投入临床试验 (some我会过早地说）用于神经退行性疾病。 这项工作 将提供关于使用这些因子的重要临床前数据， 运动神经元疾病的治疗。 本实验室建立了一套独特的器官型培养系统 用于产后大鼠脊髓。 因为这种准备结合了 培养中成熟运动神经元长期存活的优势 部分保存的突触连接，这是一个理想的系统， 测试神经营养因子是否会影响成熟运动神经元的存活 或提供保护免于退化。 它同时提供了一种方法， 确定这些生长因子的任何固有毒性，特别是 具有细胞因子样活性的细胞。 胆碱的特异性定位 乙酰转移酶活性（ChAT）的腹侧大运动神经元 腰髓允许系统评估运动神经元的技术 生存能力。 这些包括ChAT活性的生化测定， ChAT免疫细胞化学染色用于形态分析和细胞 道理 我们还使用器官型脊髓培养来提供 一种缓慢的谷氨酸介导的运动神经元变性的新模型， ALS中神经毒性的假定机制。 长期孵化 脊髓中存在苏式羟基天冬氨酸，一种有效的谷氨酸 运输抑制剂，复制相对选择性运动神经元 退化 在该模型中， 神经营养因子对运动神经元的影响将进一步研究， 深入了解神经营养作用和潜力的机制 用于治疗运动神经元疾病的药理学策略， 人症