CNS MYELINATION--ROLE OF AXOLEMMAL PROTEINS

髓鞘的沉积和维持是神经系统的重要组成部分。 系统功能无法存款和/或 维持这层膜，从轻微的运动和感觉缺陷 严重的智力迟钝和过早死亡，都与 髓鞘丢失的严重程度。虽然我们对它的结构了解很多， 髓鞘膜的功能，高度有序的机制， 并且不理解该膜的选择性加工。其实在 与周围神经系统形成鲜明对比， 神经元接触，神经元在中枢神经系统中的直接作用 (CNS)髓鞘形成尚未建立。我们相信神经元 直接在髓鞘形成中使用PAN，我们的目标是识别轴突 参与的蛋白质。我们的方法是产生单克隆的 轴突质膜蛋白特异性抗体，并检查 这些抗体干扰CNS髓鞘生成的能力。用于 在体外髓鞘形成生物测定中，我们开发了一种系统， 小脑切片培养以评估髓鞘产生和沉积。 利用这种生物测定法，我们已经确定了一个抗轴膜单克隆抗体， 抑制髓鞘形成的抗体。我们初步鉴定了 该单克隆抗体表明它针对一个或两个神经元， 细胞表面蛋白质，可能在两种细胞的髓鞘形成中发挥直接作用， 中枢和外周神经系统。的主要目的 这项研究计划是分离和表征这些蛋白质， 以确定它们在髓鞘形成中的确切作用。净化， 克隆和功能分析将作为研究的范例 在进一步的筛选中， 髓鞘形成生物测定我们在这里描述的方法将允许 鉴定这些蛋白质，并能够阐明其 功能只有在了解了关键参与者之后，我们才能 完全理解髓鞘形成的机制。

Myelin deposition and maintenance is a critical component of nervous system function. Medical consequences of the inability to deposit and/or maintain this membrane, which range from minor motor and sensory deficits to severe mental retardation and early death, are directly related to the severity of myelin loss. Although much is known about the structure and the function of the myelin membrane, the mechanism of the highly ordered and selective elaboration of this membrane is not understood. In fact, in sharp contrast to the peripheral nervous system where myelination requires neuronal contact, a direct role for neurons in central nervous system (CNS) myelination has not been established. We believe that neurons do take pan directly in myelination and our goal is to identify axonal proteins that are involved. Our approach has been to generate monoclonal antibodies specific for axonal plasma membrane proteins and examine the ability of these antibodies to interfere with CNS myelinogenesis. For an in vitro myelination bioassay, we developed a system which utilizes rat cerebellar slice cultures to assess myelin production and deposition. Using this bioassay, we have identified an anti-axolemmal monoclonal antibody that inhibits myelination. Our preliminary characterization of this monoclonal indicates that it is directed against one or two neuronal cell surface proteins, likely to play a direct role in myelination in both the central and the peripheral nervous system. The primary objective of this research proposal is to isolate and characterize these proteins in order to determine their precise role in myelination. Purification, cloning and functional analysis will serve as a paradigm for examination of additional axolemmal proteins identified in further screens using the myelination bioassay. The approach which we describe here will allow the identification of these proteins and enable the elucidation of their function. Only after the key participants are known, will we be able to fully understand the mechanism of myelination.