SCHWANN CELL AXON INTERACTION IN VITRO

本项目的长期目标是了解 雪旺细胞和轴突之间的相互作用。 这些包括 识别、粘附的机制，特别是 分化的过程相对于合成的基础 板层和髓磷脂。 本提案的近期目标 是关注分化过程中的早期分子事件 施万细胞的一部分 具体目标1和2旨在 检查特定的转录和翻译控制 髓鞘蛋白P0和P2。 据了解，添加牛 轴膜对培养的大鼠雪旺细胞的作用增加 P0蛋白的表达。 这种表达是如何调节的 （转录增加，P0-mRNA稳定，或 翻译或翻译后控制）将得到解决，因为 以及翻译后修饰的可能作用， 蛋白质的寡糖部分在P0靶向其 施旺细胞的目的地 类似的问题将得到解决 髓鞘P2蛋白;虽然没有糖基化，P2蛋白是 可能与脂质运输有关， 关于其表达的早期事件可能有助于阐明其作用 在髓鞘形成中。 P0和P2都将通过以下方式进行研究： 免疫荧光、生物化学和分子生物学 技术. 这些研究之所以成为可能， 获得并维持大量的雪旺细胞培养 通过用SV 40大T细胞转染分离的雪旺细胞， 抗原基因在金属硫蛋白启动子的控制下。 特异性目的3旨在改善表达调控 通过使用合成的金属硫蛋白启动子， 并确定大T抗原是否影响 髓鞘特异性成分。 在后一种情况下， 大T抗原对髓磷脂蛋白表达的影响可能具有一定的临床意义。 与人类进行性脱髓鞘疾病直接相关 多灶性白质脑病，一种由JC病毒引起的疾病。 此外，全面了解 轴突和雪旺细胞应该提供了深入了解 脱髓鞘的病理生理学以及 髓鞘再生 这可能会导致一种更合理的方法， 人类周围神经疾病的治疗。

The long term goals of this project are to understand the bases of the interactions between Schwann cells and axons. These include the mechanism of recognition, adhesion and in particular, the process of differentiation with respect to the synthesis of basal lamina and myelin. The immediate aims in the present proposal are to focus on the early molecular events during differentiation of the Schwann cell. Specific Aims 1 and 2 are designed to examine transcriptional and translational control of specific myelin proteins P0 and P2. It is known that addition of bovine axolemma to rat Schwann cells in culture results in increased expression of P0 protein. How this expression is regulated (increased transcription, stabilization of P0-mRNA, or translational or post-translational control) will be addressed, as well as the possible role of post-translational modification of the oligosaccharide portion of the protein in targeting of P0 to its destination in Schwann cells. Similar questions will be addressed to myelin P2 protein; although not glycosylated, P2 protein is probably involved in lipid transport and therefore information about the early events in its expression may shed light on its role in myelination. Both P0 and P2 will be studied by immunofluorescence, biochemical and molecular biological techniques. These studies are made possible by our ability to obtain and maintain large quantities of Schwann cells in culture by transfection of isolated Schwann cells with the SV40 large T antigen gene under the control of a metallothionein promoter. Specific Aim 3 is designed to improve the regulation of expression of the T antigen by use of synthetic metallothionein promoters, and to determine whether large T antigen affects the expression of myelin-specific components. In the latter instance, the effect of large T antigen on the expression of myelin protein may have a direct bearing on a human demyelinating disease, progressive multifocal leucoencephalopathy, a disease caused by JC virus. Moreover, the overall understanding of the interaction between axons and Schwann cells should provide insight into the pathophysiology of demyelination as well as repair by remyelination. This could result in a more rational approach to the treatment of human peripheral nerve diseases.