SLOW AXONAL TRANSPORT IN CNS DEVELOPMENT

中枢神经系统发育中的慢轴突运输

• 批准号: 3402793
• 负责人: Monica Oblinger
• 金额: $ 16.16万
• 依托单位: ROSALIND FRANKLIN UNIV OF MEDICINE & SCI
• 依托单位国家: 美国
• 财政年份: 1985
• 资助国家: 美国
• 起止时间: 1985-09-01 至 1993-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3402793
• 关键词: actins; axon; axon reaction; central nervous system disorders; cytoskeleton; fluorimetry; gel electrophoresis; gene expression; genetic transcription; genetic translation; hamsters; immunochemistry; injury; laboratory rat; messenger RNA; microtubule associated protein; microtubules; monoclonal antibody; motor cortex; nervous system regeneration; neural plasticity; neurofilament; neurofilament proteins; neurogenesis; neuronal transport; nucleic acid probes; phosphorylation; protein biosynthesis; pyramidal tracts; radioassay; transport proteins; tubulin

A major problem in contemporary medicine is the failure of regrowth of injured CNS axons. Cytoskeletal proteins have a central role in axonal growth both during developmental and after injury. The process of delivery of cytoskeletal elements is vectorial; transcription, translation and assembly occur largely in the cell body and the products are exported to the axon where important posttranslational modifications occur. The cytoskeleton then continually moves by slow axonal transport to the terminal. Following injury, this vectorial process must apply cytoskeletal elements to the growing regions in order for a new axon to form. One of the possible explanations for mammalian CNS regenerative failure is that some aspect of this vectorial process is suboptimal. We propose to continue studies which examine this hypothesis by conducting both longitudinal studies of a CNS system which undergoes a critical period of development in which regeneration fails and by comparative studies that examine injured peripheral neurons. The hamster corticospinal system provides the CNS model since these neurons elaborate axons entirely postnatally and maintain the ability to regenerate after injury for the first 2 postnatal weeks. After that critical period, injury results in regenerative failure and permanent functional loss. We will first examine changes in the mRNA levels of the low and high molecular weight neurofliament proteins, two different beta tubulins and actin during normal development of corticospinal neuronals using quantitative in situ hybridization with cDNA probes. This will provide information on the initial appearance of transcriptional products, clues on the extent to which major cytoskeletal genes are transcriptionally coregulated, and target changes which occur during the critical period for regrowth of this system. Immunochemical studies of developing corticospinal neurons with specific monoclonal antibodies will complement the studies of mRNA changes by examining both the expression and modification of major cytoskeletal proteins. Second, we will axotomize corticospinal neurons at different developmental stages and determine how cytoskeletal gene expression changes using quantitative in situ hybridization with cDNA probes. Immunochemical studies will provide information about the protein products and changes in their posttranslational modifications (such as NF phosphorylation) that result after injury. Third, we will conduct comparative studies of the injury response of the dorsal root ganglion (DRG) cell to determine the molecular changes mounted

现代医学的一个主要问题是再生失败 受伤的中枢神经系统轴突。 细胞骨架蛋白具有核心作用 发育期间和损伤后的轴突生长。 这 细胞骨架元件的传递过程是矢量的； 转录、翻译和组装主要发生在细胞中 身体和产品被输出到重要的轴突 发生翻译后修饰。 那么细胞骨架 通过缓慢的轴突运输不断移动到终点站。 受伤后，该矢量过程必须应用细胞骨架 元素添加到生长区域，以便形成新的轴突。 哺乳动物中枢神经系统再生的可能解释之一 失败的是这个向量过程的某些方面是 次优。 我们建议继续研究以检验这一点 通过对中枢神经系统系统进行纵向研究的假设 正处于发展的关键时期 再生失败并通过检查受伤的比较研究 周围神经元。 仓鼠皮质脊髓系统提供 中枢神经系统模型，因为这些神经元完全在出生后形成轴突 并在受伤后第一时间保持再生能力 产后2周。 在这个关键时期之后，受伤会导致 再生失败和永久性功能丧失。 我们首先会 检查低分子和高分子 mRNA 水平的变化 重量神经丝蛋白，两种不同的β微管蛋白和 皮质脊髓神经元正常发育过程中的肌动蛋白 与 cDNA 探针进行定量原位杂交。 这将 提供有关转录最初出现的信息 产品，有关主要细胞骨架基因的程度的线索 转录共同调节，以及发生的目标变化 在该系统再生的关键时期。 皮质脊髓神经元发育的免疫化学研究 特异性单克隆抗体将补充 mRNA 研究 通过检查主要的表达和修饰来改变 细胞骨架蛋白。 其次，我们将皮质脊髓轴突切断 不同发育阶段的神经元并决定如何 使用原位定量分析细胞骨架基因表达变化 与cDNA探针杂交。 免疫化学研究将 提供有关蛋白质产品及其变化的信息 翻译后修饰（例如 NF 磷酸化） 受伤后的结果。 三、我们要进行比较研究 of the injury response of the dorsal root ganglion (DRG) cell to 确定安装的分子变化