CLONAL LINES OF THE NERVOUS SYSTEM

神经系统的克隆系

• 批准号: 3394340
• 负责人: STEVEN E PFEIFFER
• 金额: $ 21.72万
• 依托单位: UNIVERSITY OF CONNECTICUT SCH OF MED/DNT
• 依托单位国家: 美国
• 财政年份: 1977
• 资助国家: 美国
• 起止时间: 1977-01-01 至 1994-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3394340
• 关键词: antiidiotype antibody; autoradiography; axon; cell differentiation; cell line; cell migration; cell population study; cell type; central nervous system; cerebrosides; chemical binding; clone cells; developmental genetics; early embryonic stage; electron microscopy; flow cytometry; fluorescent dye /probe; gene expression; growth media; immunocytochemistry; laboratory rabbit; laboratory rat; membrane activity; mixed tissue /cell culture; monoclonal antibody; myelin; myelination; myelinopathy; neurochemistry; neurogenesis; neurotrophic factors; newborn animals; nucleic acid probes; oligodendroglia; protein kinase C; radioimmunoassay; radiotracer; surface antigens; synchronous cell division

The formation of myelin sheath in the CNS by oligodendrocytes (OL) is a complex developmental process with numerous intermediate steps. Programmed myelin gene expression is regulated by both genetic factors intrinsic to these cells,and by environmental influences encountered as the cells proliferate and migrate from their sites of embryological origin to their neurons. During this period OL progenitor differentiation proceeds along a specific lineage pathway in a highly regulated sequence of events, resulting in the formation of myelinated neuronal axons. This project aims to increase our understanding of how extrinsic factors regulate OL differentiation and myelin formation by identifying and characterizing environmental factors that regulate myelinogenesis,and by analyzing the cellular and molecular mechanisms by which they operate. The project focuses on events occuring during the early stages of myelinogenesis,during which progenitor cells become committed specifically to the lineage,and differentiate into identifiable OL. A critical step in this developmental lineage,characterized experimentally by the expression of the O4 antigen but the absence of galactocerebroside (i.e., O4+GalC- ),will be examined. During this stage the progenitor cells are triggered to initiate the cascade of terminal differentiation,heralded by the expression of galactocerebroside,and followed sequentially by a complement of myelin-specific structural components. We have recently developed a procedure for the immuno-isolation of O4+GalC- cells. Two subpopulations exist within the isolated O4+GalC- progenitor population, a major (80%) subpopulation of "proligodendrocytes" that rapidly and synchronously differentiate into authentic OL in culture,and a minor (20%) subpopulation of "procrastocytes" that remain GalC-. These two coexisting populations will be further characterized with the regard to the environmental regulation of their survival,proliferation,migration,and differentiation,by both previously identified "broad spectrum" growth factors and by novel activities that we have demonstrated in cell- conditioned media. These studies will emphasize the analysis of the cellular mechanisms involved,and the purification and characterization of previously unidentified factors. We have shown that the differentiation of OL progenitors in dissoclated cultures of rat brain can be either stimulated or reversibly inhibited during this critical developmental stage by OL-specific monoclonal antibodies,in particular anti-galactolipids. We have hypothesized that the target antigens act as receptors and ligands in the response of OL to their environment. An analysis will be carried out to determined (a) the cellular and biochemical mechanisms by which these antibody pertubations proceed,(b) the identification of the molecular identities of the cell surface complexes of which these antigens are a part,and (c) the target binding sites on OL themselves and on other cells with which these oligodendrocyte surface antigens interact. These data will contribute to our understanding of a critical step of OL differentiation,thereby providing useful clues to processes critical to myelin formation,maintenance,and remyelination in both the normal and pathological state. In particular,these data are expected to bear on the stimulation of remyelination in disease states such as Multiple Sclerosis by providing information of the information of the environmental requirements for the successful transplantation of OL progenitors and the activation of dormant progenitors that appear to exist in the adult CNS.

少突胶质细胞（OL）在中枢神经系统中的髓鞘形成是一个 复杂的发展过程，具有许多中间步骤。 编程的髓磷脂基因表达受两个遗传因素的调节 这些细胞固有的，以及通过环境影响遇到的 细胞扩散并从胚胎起源迁移 致神经元。 在此期间OL祖细胞分化 在高度调节的序列中沿特定谱系途径进行进行 事件，导致形成髓神经元轴突。 这 项目旨在提高我们对外在因素如何的理解 通过识别和 表征调节脊髓纤维化的环境因素，并通过 分析其操作的细胞和分子机制。 该项目着重于在早期阶段发生的事件 骨髓生成，在此期间祖细胞变得专门投入 到谱系，并分化为可识别的OL。 关键的一步 这种发育谱系，以表达方式进行实验表征 O4抗原但缺乏半乳脑乳糖苷（即O4+Galc- ）将被检查。 在此阶段触发祖细胞 启动一系列终端差异化，预示着 半乳脑的表达，然后依次进行补体 髓磷脂特异性结构成分。 我们最近开发了 O4+GALC细胞免疫溶解的程序。两个亚群 存在于孤立的O4+Galc-祖细胞种群中，主要是（80％） 迅速和同步的“刺激细胞”的亚群 在培养中分为正宗的OL，而次要（20％）亚群 仍然是galc-的“拖延细胞”的。 这两个共存人群 将进一步以环境为特征 调节其生存，增殖，迁移和 通过以前确定的“广泛”生长的分化 因素和通过我们在细胞中证明的新型活动 条件媒体。 这些研究将强调分析 涉及的细胞机制以及纯化和表征 以前未识别的因素。 我们已经证明了元素在解析中的分化 大鼠脑的培养物可以刺激或可逆地抑制 在OL特异性单克隆的关键发育阶段 抗体，特别是抗半乳脂。 我们假设 靶抗原充当OL反应中的受体和配体 他们的环境。 将进行分析以确定（a） 细胞和生化机制，这些抗体均匀性 继续，（b）鉴定细胞的分子身份 这些抗原是一部分的表面复合物，（c）目标 在OL本身和其他细胞上的结合位点 少突胶质细胞表面抗原相互作用。 这些数据将有助于我们理解OL的关键步骤 差异化，从而提供有用的线索来处理至关重要的处理 正常和 病理状态。 特别是，这些数据有望在 在疾病状态（例如多发性硬化症）中刺激再髓样 通过提供环境信息的信息 成功移植OL祖细胞和 成年中枢神经系统中似乎存在的休眠祖细胞的激活。