CLONAL LINES OF THE NERVOUS SYSTEM

神经系统的克隆系

• 批准号: 3394338
• 负责人: STEVEN E PFEIFFER
• 金额: $ 21.22万
• 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/3394338
• 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）在中枢神经系统中形成髓鞘是一个重要的过程。 复杂的发育过程，中间有许多步骤。 程序化髓鞘基因表达受两种遗传因素的调控 这些细胞固有的，并受到环境的影响， 细胞增殖并从其胚胎起源部位迁移 到他们的神经元。 在此期间，OL祖细胞分化 沿着一个高度调节的序列中的特定谱系途径进行 的事件，导致有髓鞘神经元轴突的形成。 这 该项目旨在增加我们对外在因素如何影响 通过识别和调节OL分化和髓鞘形成， 表征调节髓鞘生成的环境因素， 分析它们运作的细胞和分子机制。 该项目的重点是在早期阶段发生的事件， 髓鞘生成，在此期间，祖细胞特异性地 并分化成可识别的OL。 的关键步骤 这种发育谱系的实验特征是 O 4抗原但不存在半乳糖脑苷脂（即，O4+GalC- ），将予以审查。 在这个阶段，祖细胞被触发， 以启动终末分化的级联反应， 半乳糖苷的表达，随后依次是补体 髓鞘特异性的结构成分。 我们最近开发了一种 O 4 +GalC-细胞的免疫分离程序。两个亚群 存在于分离的O 4 +GalC-祖细胞群体中，主要（80%） “前突胶质细胞”亚群， 在培养物中分化为真正的OL，并且少数（20%）亚群 的“拖延细胞”保持GalC-。 这两个共存的种群 将进一步与环境方面的特点， 调节其生存、增殖、迁移， 分化，通过先前确定的“广谱”生长 我们已经在细胞中证明了这些新的活性， 条件培养基 这些研究将着重分析 涉及的细胞机制，以及纯化和表征 以前未发现的因素。 我们已经证明，OL祖细胞的分化在溶解的 大鼠脑培养物可以被刺激或可逆地抑制 在这个关键的发育阶段，通过OL特异性单克隆抗体 抗体，特别是抗半乳糖脂。 我们假设 靶抗原作为受体和配体参与OL对 他们的环境。 将进行分析以确定（a） 这些抗体扰动的细胞和生化机制 进行，（B）鉴定细胞的分子身份 这些抗原是其一部分的表面复合物，和（c）靶 OL自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的一个关键步骤 分化，从而提供有用的线索，关键的过程， 髓鞘形成，维持和髓鞘再生，在正常和 病态 特别是，这些数据预计将对 在疾病状态如多发性硬化中刺激髓鞘再生 通过提供环境信息的信息， 成功移植OL祖细胞的要求和 激活似乎存在于成年CNS中的休眠祖细胞。