Regulation of oligodendrocyte differentiation by BMP

描述（由申请人提供）：少突胶质细胞的分化 从发育中的中枢神经系统中的神经外胚层干细胞， 空间限制，似乎取决于当地的环境因素 线索这种调节可能取决于各种因素，有些是归纳的， 如音刺猬，和其他压抑，如缺口信号。为了 了解少突胶质细胞的发育，并试图改善恢复 在髓鞘形成障碍或脱髓鞘之后，重要的是识别这些 并了解它们如何相互作用。 我们一直在研究一种可能的抑制少突胶质细胞的因子 发育，骨形态发生蛋白（BMP），转化 生长因子β家族参与背侧组织的特化， 调节中枢神经系统发育的许多不同方面， 也存在于成人中。我们在组织培养中的研究表明BMPs 2 和4对少突胶质细胞谱系具有阶段特异性作用。在 前祖细胞或前体阶段，BMP抑制分化为 少突胶质细胞并促进星形胶质细胞生成。BMP失去这种影响后， 少突胶质细胞成熟。骨形态发生蛋白对少突胶质细胞生成的影响 一直难以捉摸我们已经获得了三种类型的基因敲除小鼠， 使我们能够确定BMP在少突胶质细胞生成中的作用， 星形胶质细胞生成我们将采用神经管特异性条件性敲除， 最广泛表达的BMP受体，BMPR-IA，BMP-IB的敲除， 受体和其中两种受体均缺失的双敲除。初步 体外产生的数据表明，正常的BMP介导的抑制， 在源自Bmpr-la的培养物中，少突胶质细胞成熟被破坏 击倒和双击倒。BMP介导的星形胶质细胞生成只有在 在双敲除中，表明IA和IB的功能冗余 受体。我们计划分析这三个突变体来确定 每种I型受体的贡献以及 BMP信号的抑制。我们假设BMP的消除 体内的信号传导将导致异位和/或过早出现 少突胶质细胞伴随较少的星形胶质细胞。我们将执行 免疫组织化学方法对三种动物的脑和脊髓切片进行了研究。 突变体和对照以及蛋白质印迹以确定体内 方面的影响.然后，我们将在体外培养这些动物的少突胶质细胞， 确定BMP如何调节少突胶质细胞分化和星形胶质细胞 阵我们还将通过一种可能的方式来研究BMP的信号传导。 下游介质，分化抑制剂的Id蛋白家族。 我们的初步数据表明，身份证的表达在BMP突变体的改变。

DESCRIPTION (provided by applicant): The differentiation of oligodendrocytes from neuroectodermal stem cells in the developing central nervous system is spatially restricted and appears to depend on local factors for environmental cues. This regulation may depend on a variety of factors, some inductive, such as sonic hedgehog, and others repressive, such as notch signaling. In order to understand oligodendrocyte development and attempt to improve recovery following dysmyelination or demyelination, it is important to identify these factors and learn how they interact. We have been studying a possible repressive factors for oligodendrocyte development, bone morphogenetic protein (BMP), members of the transforming growth factor Beta family involved in specification of dorsal tissues, that modulate many diverse aspects of central nervous system development and are also present in the adult. Our studies in tissue culture have shown that BMPs 2 and 4 have stage-specific effects on the oligodendrocyte lineage. In the pre-progenitor or precursor stage, BMP inhibits differentiation to oligodendrocytes and promotes astrogliogenesis. BMP loses this affect after the oligodendrocyte matures. The effect of BMP on oligodendrogliogenesis in vivo has been elusive. We have obtained three types of knockout mice that will enable us to determine the role of BMP in oligodendrogliogenesis and astrogliogenesis. We will employ a neural tube-specific conditional knockout of the most widely expressed BMP receptor, BMPR-IA, a knockout of the BMP-IB receptor and a double knockout in which both receptors are deleted. Preliminary data generated in vitro indicates that the normal BMP-mediated suppression of oligodendrocyte maturation is disrupted in cultures derived from the Bmpr-la knockouts and double knockouts. BMP-mediated astrogliogenesis is only disrupted in the double knockouts suggesting a functional redundancy of the IA and IB receptors. We plan to analyze these three mutants to determine the relative contribution of each of the type I receptors as well as the overall effect of the inhibition of BMP signaling. We hypothesize that the elimination of BMP signaling in vivo will cause ectopic and/or premature appearance of oligodendrocytes concomitant with fewer astrocytes. We will perform immunohistochemistry on sections of brain and spinal cord from the three mutants and controls as well as western blotting to determine the in vivo effects. We will then culture oligodendrocytes from these animals in vitro and determine how BMP regulates oligodendrocyte differentiation and astrocyte formation. We will also look at signaling from BMP through a possible downstream mediator, the Id protein family of inhibitors of differentiation. Our preliminary data suggests that Id expression is altered in the BMP mutants.