BIOCHEMICAL STUDY OF MYELINATION AND DEMYELINATION

本应用程序的总体目标是研究生物化学和 多发性硬化(MS)脱髓鞘的免疫学基础 实验性变态反应性脑脊髓炎(EAE)及其生化 影响髓鞘形成和再髓鞘形成的参数。我们的重点是 糖鞘糖脂(GSLS)在这些事件中的作用。由于GSLS是 主要定位于细胞表面，已知经历了细胞- 特定的、发育调节的变化，它们是极好的 用于监测髓鞘形成过程中发生的细胞事件的标志物 脱髓鞘。它们在这方面的重要性由以下方面进一步强调： (A)发现存在独特的糖脂抗原 神经系统和内皮细胞，以及(B)某些GSLS是强大的 免疫细胞生长和分化的调节剂。在…的第一个领域 研究的一个主要目标是提供更多关于髓鞘的生化数据 崩溃，相关的神经胶质反应，以及重新髓鞘形成。这是 由开发的几种新奇和高度敏感的 分析特定蜂窝GSL组件的程序。免疫学 对多发性硬化症的研究一直很广泛，有强有力的证据表明， 自身免疫机制可能在该病的发病机制中起重要作用。 疾病。涉及髓鞘和髓鞘的自身抗原(S) 多发性硬化症少突胶质细胞变性的定义尚不清楚。我们 假设MS和EAE的炎性脱髓鞘可能是 由CNS髓鞘蛋白特异性自身反应性T细胞触发 糖偶联物，并通过对靶抗原的体液反应 特异性地定位于内皮细胞和中枢神经系统。幽默 对内皮的反应可能是血管通透性的原因 改变之前的脱髓鞘。这一假设将通过以下方式进行检验 体外和体内模型系统。在第二个研究领域，我们 计划将重点放在合成高含量的半乳脑苷脂(GC)上 富含髓鞘的。由于GC有两种类型，因此有可能 它们是由两种不同的半乳糖基转移酶合成的。 我们计划提纯这两种酶，并研究它们的亚细胞 定位，并阐明酶活性的调节 在分子生物学技术的发展过程中。自.以来 半乳糖基转移酶明显存在于少突胶质细胞的血浆中 膜和髓鞘，我们认为它们可能起到膜黏附的作用。 形成髓鞘多层结构的分子。一个 了解半乳脑苷脂的合成和功能应 增强我们对调节髓鞘形成和再髓鞘形成的因素的认识。

The overall objective of this application is to study the biochemical and immunological basis of demyelination in multiple sclerosis (MS) and experimental allergic encephalomyelitis (EAE), as well as the biochemical parameters affecting myelination and remyelination. Our emphasis is placed on the role of glycosphingolipids (GSLs) in these events. Since GSLs are localized primarily on the cell surface and are known to undergo cell- specific, developmentally regulated changes, they serve as excellent markers for monitoring cellular events occurring during myelination and demyelination. Their importance in this regard is further underscored by: (a) the discovery that there are unique glycolipid antigens common to the nervous system and the endothelial cells, and (b) certain GSLs are powerful modulators of immune cell growth and differentiation. In the first area of research, a major goal is to provide additional biochemical data on myelin breakdown, the associated gliotic reactions, and remyelination. This is facilitated by the development of several novel and highly sensitive procedures for analyzing specific cellular GSL components. Immunological research in MS has been extensive, and there is strong evidence that an autoimmune mechanism may play an important role in the pathogenesis of this disease. The autoantigen(s) that are involved in myelin and oligodendroglial degeneration in MS have not been clearly defined. We hypothesize that the inflammatory demyelination in MS and EAE may be triggered by autoreactive T cells specific for CNS myelin proteins and glycoconjugates, and by humoral response against target antigens specifically localized in endothelial cells and the CNS. The humoral response against the endothelium may account for the vascular permeability change preceding demyelination. This hypothesis will be tested employing in vitro and in vivo model systems. In the second area of research, we plan to focus on the synthesis of galactocerebrosides (GC) which are highly enriched in myelin. Since there are two types of GC, the possibility exists that they are synthesized by two distinct galactosyltransferases. We plan to purify these two enzymes and to study their subcellular localization, and to elucidate the regulation of the enzyme activities during development by molecular biological techniques. Since galactosyltransferases are apparently found in oligodendroglial plasma membrane and myelin, we propose that they may function as membrane adhesion molecules for the formation of the multilamellar structure of myelin. An understanding of the synthesis and function of galactocerebrosides should enhance our knowledge on factors modulating myelination and remyelination.