TROPHIC DETERMINANTS OF OLIGODENDROCYTE DEVELOPMENT

少突胶质细胞发育的营养决定因素

• 批准号: 2267772
• 负责人: ANTHONY LORENTZ GARD
• 金额: $ 13.44万
• 依托单位: UNIVERSITY OF SOUTH ALABAMA
• 依托单位国家: 美国
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-09-30 至 1996-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2267772
• 关键词: antigens; astrocytes; cell cycle; cell death; cell differentiation; cell population study; cerebrosides; cerebrum; developmental neurobiology; fibroblast growth factor; growth factor; high performance liquid chromatography; laboratory mouse; laboratory rat; mutant; myelination; neurogenesis; oligodendroglia; protein kinase C; protein purification; protein structure function; receptor sensitivity; tissue /cell culture

Myelination of the CNS is an orderly process initiated by development of the oligodendrocyte (OL). During an early proliferative phase, migratory glial precursor cells seed axonal fiber tracts in brain as they enter a specific lineage. Post-migratory differentiation heralds the end of proliferation and the onset of programmed gene expression to construct the myelin sheath. The regulation of these events is complex, involving the interplay of factors intrinsic to the cell with environmental cues encountered along its developmental course. The overall aim of this project is to define specific environmental signals that direct myelinogenesis at a crucial juncture of OL development, and resolve the cellular and molecular mechanisms by which they operate. Investigation will focus in vitro on the growth control of cells that have reached an intermediate progenitor step of the lineage in vivo. In the rat these cells are defined by a distinct surface antigenic phenotype; O4 antigen is expressed in the absence of galactocerebroside, a marker for further differentiation. Preliminary studies were designed to expose, in defined cell culture, growth requirements of 04+GalC- as they form and proliferate in vivo. Immunoselection technology was applied to isolate the progenitors directly from premyelinating brain. It was shown that cells at this stage are committed to terminal differentiation in vitro, but require extrinsic signals for both survival and proliferation. Culture medium conditioned by astrocytes from neonatal rat brain specifically prevents the death of progenitor cultures, but is neither mitogenic nor inhibitory of their subsequent differentiation program. Because the activity is potent, proteinaceous (approximately 10-30 kDa), and distinct from tested mitogens (bFGF and PDGF) it is hypothesized that OL viability is promoted by an unrecognized trophic factor. Further experimentation in vitro will analyze this factor with regard to its (a) cellular action (b) purification and biochemical characterization (c) expression into adulthood and (d) relationship to a genetic model of accelerated OL death in the hypomyelinating jimpy mouse. Progenitor proliferation is restored normally by neuron-conditioned culture medium, as well as basic fibroblast growth factor (FGF) which at higher doses is mitogenic for "post-mitotic'. OL It is hypothesized that FGF plays a changing role during the OL lineage, with mitogenic as well as unrecognized functions. Further studies will characterize FGF receptors and related signal transduction pathways utilized by progenitors and differentiated oligodendrocytes. The capacity to culture both cell types in isolation and high yield enables pharmacological and biochemical analyses. These data are expected to contribute to our knowledge of the epigenetic control of myelinogenesis and will provide insight concerning a trophic basis for the etiology and prospective treatment of dysmyelinating diseases.

中枢神经系统的髓鞘化是通过开发的有序过程 少突胶质细胞（OL）。 在早期增生阶段，迁移 胶质前体细胞进入大脑中的轴突纤维纤维。 特定谱系。 迁移后分化预示了 增殖和编程基因表达的发作以构建 髓鞘。这些事件的调节很复杂，涉及 与环境线索的固有因素​​的相互作用 在其发展过程中遇到。 总体目的 项目是定义直接的特定环境信号 在OL发育的关键关键时期，脊髓纤维发生，并解决 它们运行的​​细胞和分子机制。 调查 将重点放在已经达到的细胞的生长控制上 体内谱系的中间祖细胞步骤。 在老鼠中 细胞由不同的表面抗原表型定义。 O4抗原是 在没有半乳脑乳剂的情况下表达，一个标记以进一步 分化。 初步研究旨在暴露于定义 细胞培养，生长需求为04+GALC-形成并增殖 体内。 采用免疫选择技术来隔离祖细胞 直接来自前髓的大脑。 结果表明该阶段的细胞 承诺在体外终末分化，但需要外部 生存和增殖的信号。 培养基 来自新生大鼠大脑的星形胶质细胞明确防止了死亡 祖细胞培养物，但既不是有丝分裂的，也不是其抑制作用 随后的分化计划。 因为活动有效， 蛋白质（约10-30 kDa），与测试有丝分裂原不同 （BFGF和PDGF）假设OL生存力是由 未识别的营养因素。 进一步的体外实验将分析 这个因素（a）细胞作用（b）纯化和 生化表征（C）表达成年和（d） 与加速死亡的遗传模型的关系 低西氏吉普小鼠。 正常恢复祖细胞增殖 通过神经元调节培养基以及基本成纤维细胞生长 因子（FGF），在较高剂量的“丝裂后”是有丝分裂的。 假设FGF在OL血统期间起着变化的作用， 具有有丝分裂的功能以及未认可的功能。 进一步的研究将会 表征FGF受体和相关信号转导途径 由祖细胞和分化的少突胶质细胞使用。 容量 培养两种细胞类型的孤立和高产量可以培养 药理和生化分析。 这些数据有望 有助于我们了解脊髓纤维形成的表观遗传控制和 将提供有关病因的营养基础的洞察力 前瞻性治疗障碍性疾病。