SPINAL CORD INJURY: ALTERATIONS IN BARRIER PERMEABILITY

脊髓损伤：屏障渗透性的改变

• 批准号: 3406648
• 负责人: LINDA J. NOBLE
• 金额: $ 10.08万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 1985
• 资助国家: 美国
• 起止时间: 1985-08-01 至 1990-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3406648
• 关键词: adenosinetriphosphatase; alkaline phosphatase; apical membrane; developmental neurobiology; electron microscopy; embryo /fetus; histochemistry /cytochemistry; laboratory rat; macromolecule; microscopy; newborn animals; nonsurgical revascularization; oligosaccharides; protein structure; spinal cord injury; spinal shock; transport proteins; trauma; vascular endothelium permeability

The passage of macromolecules across the blood-CNS barrier is severely restricted by the paucity of transendothelial vesicular transport (VT). It is clear that in injury states and during development, VT does occur and in the case of the former is linked to edema formation and subsequent pathologic events. Although in the developing CNS VT may serve as an important mechanism for nutrient transport across immature endothelial cells, we believe that this relatively non-selective mechanism may render the developing CNS more vulnerable. This is particularly relevant to understanding the toxic effects of environmental agents or drugs which impair the developing CNS but do not effect the mature CNS. Therefore, in this proposal we have selected developmental and injury models in order to evaluate changes in the structural features of the endothelial cell which are associated with VT. The overall purpose of this proposal is to 1: examine the role of endothelial surface charge and glycoprotein structure in macromolecular transport across spinal cord microvessels and 2: evaluate the relationship between endothelial enzymes and transendothelial VT. We propose that the blood-spinal cord barrier to macromolecular transport is dependent upon a distinctive glycocalyx, resulting in an anionic surface charge, and that an immature or disrupted glycocalyx is associated with macromolecular transport. Furthermore, we hypothesize that vascular membrane alterations are not confined to VT but are also reflected in the loss or redistribution of endothelial enzymes. Outcome measures include quantitative light and electron microscopy of endothelial enzymes and surface charge and structure. The development of enzymes (alkaline phosphatase, gamma glutamyl transpeptidase, and Na, K, ATPase) will be studied cytochemically beginning at embryonic day II. Furthermore, development of constituents of the endothelial glycocalyx will be analyzed using biotinylated lectins (Concanavalin A, Ricinus communis, and soybean agglutinin) to localize oligosaccharide residues on the luminal plasma membrane. Finally, the relationship between VT and luminal surface charge during development will be examined using the macromolecular tracer horseradish peroxidase in conjunction with anionic and cationized ferritin. Similar outcome measures will be applied to both spinal cord contusive and freeze injury models. The former model provides a source of vessels which exhibit transient VT. The latter model was selected in order to study the relationship between and orderly pattern of vascular regeneration and mechanisms associated with reconstitution of vascular integrity. These studies will provide a necessary foundation for understanding regulatory control of macromolecules across the barrier with an ultimate goal of identifying factors which may contribute to barrier modulation and/or stabilization after CNS trauma or during early CNS development.

大分子在血液CNS屏障中的通过是 严重限制了跨内皮囊泡的缺乏 运输（VT）。 显然，在伤害状态和期间 开发，VT确实发生了，在前者的情况下是 与水肿形成和随后的病理事件有关。 尽管在开发的CNS VT中可能是重要的 营养转运的机制跨过未成熟的内皮 细胞，我们认为这种相对非选择性机制 可能会使开发的中枢神经系统更加脆弱。 这是 与了解 损害开发中枢神经系统的环境药物或药物 但不要影响成熟的中枢神经系统。 因此，在这个建议中我们 选择了发展模型和伤害模型 评估内皮细胞的结构特征的变化 与VT相关的。 该提议的总体目的是：1：检查 内皮表面电荷和糖蛋白结构 大分子跨脊髓微血管和2： 评估内皮酶与 跨内皮VT。 我们提出了脊髓 大分子转运的障碍取决于 独特的糖蛋白，导致阴离子表面电荷，并且 未成熟或破坏的糖脂与 大分子转运。 此外，我们假设 血管膜的改变不仅限于VT，但也是 反映在内皮酶的损失或重新分布中。 结果指标包括定量光和电子 内皮酶和表面电荷的显微镜，以及 结构。 酶的发展（碱性磷酸酶， γ谷氨酰基转肽酶和Na，K，ATPase）将是 从胚胎第二天开始研究细胞化学。 此外，发展内皮成分的发展 将使用生物素化凝集素分析糖脂蛋白 （姜黄素A，Ricinus Communis和大豆凝集素） 将寡糖残基定位在腔等离子体上 膜。 最后，VT和Luminal之间的关系 开发过程中的表面充电将使用 大分子示踪辣根过氧化物酶与 阴离子和阳离子铁蛋白。 类似的结果指标将是 应用于脊髓抑制和冻伤模型。 前者提供了展示的血管来源 瞬态VT。 选择后一种模型是为了研究 血管再生和有序模式之间的关系 和与血管重构相关的机制 正直。 这些研究将为 了解整个大分子的调节控制 障碍的最终目标是确定可能的因素 CNS后有助于屏障调制和/或稳定 创伤或中枢神经系统早期开发期间。