STRESS MODULATION OF CHOLINE TRANSPORT BY CHOROID PLEXUS

脉络丛胆碱运输的应激调节

• 批准号: 6330614
• 负责人: Alice Renee Villalobos
• 金额: $ 18.73万
• 依托单位: UNIVERSITY OF ROCHESTER
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-12-10 至 2002-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6330614
• 关键词: acetylcholine; active transport; cerebrospinal fluid; choline; choroid plexus; electrophysiology; epithelium; fluorescence microscopy; heat shock proteins; heat stimulus; immunochemistry; ion transport; laboratory rat; microfilaments; microtubules; mitogen activated protein kinase; neuroprotectants; neurotransmitter biosynthesis; newborn animals; physiologic stressor; radiotracer; tissue /cell culture

The long term goal of this research is to establish an experimental system for predicting pharmacological and physicochemical stress-modulation of mediated transport of endogenous and xenobiotic organic cations across the cerebrospinal fluid (CSF)-blood barrier by the intact choroid plexus. The immediate objective of this proposed research is to characterize the role of the choroid plexus epithelium, which comprises the ventricular CSF-blood barrier, in regulation of choline levels in the central nervous system. Choline is a polar constituent of neuronal membranes and an immediate precursor to acetylcholine, the neurotransmitter for the central cholinergic neuronal pathways crucial in neural control of behaviors such as sleep-wake cycling and learning or memorization. Choline availability is rate-limiting in acetylcholine synthesis and critical to normal brain development in the neonate. The proposed research will test the hypothesis that choline is actively transported across the ventricular CSF-blood barrier and, therefore, modulation of this active transport process by pharmacological and physiochemical stresses may alter brain levels of choline. This hypothesis will be tested directly using a primary culture system of choroidal plexus epithelial cells isolated from neonatal rats. Radiotracer, molecular biology, immunochemistry and fluorescence microscopy techniques will be used concurrently to meet the specific aims of this proposal. These are i.) The characterization of cellular mechanisms that mediate choline transport across the CSF-blood barrier by choroid plexus; ii.) The characterization of the role of the heat shock protein, Hsp27, in rapidly induced modulation of choline transport following mild heat-stress, iii) the examination of heat stress-induced thermoprotection of choroid plexus choline transport. Deficits or increases in free choline levels in the brain are associated with central nervous development in children and central nervous disorders, such as Alzheimer s disease, cerebral ischemia and central organophosphate neurotoxidation in adults. Therefore, a greater understanding of the energetics and modulation of medicated choline transport across the CSF-blood barrier would allow more effective prevention, management and treatment of such disorders.

这项研究的长期目标是建立一个实验系统，用于预测完整脉络丛跨脑脊液（CSF）-血液屏障介导的内源性和外源性有机阳离子转运的药理学和物理化学应激调节。 这项研究的直接目标是表征脉络丛上皮（包括心室脑脊液血屏障）在调节中枢神经系统胆碱水平中的作用。 胆碱是神经元膜的极性成分，也是乙酰胆碱的直接前体，乙酰胆碱是中枢胆碱能神经元通路的神经递质，对于神经控制行为（如睡眠-觉醒循环和学习或记忆）至关重要。 胆碱的可用性是乙酰胆碱合成的速率限制，对于新生儿的正常大脑发育至关重要。 拟议的研究将检验胆碱主动转运穿过心室脑脊液血屏障的假设，因此，通过药理学和生理化学应激调节这种主动转运过程可能会改变大脑中胆碱的水平。 该假设将使用从新生大鼠中分离的脉络丛上皮细胞的原代培养系统直接进行测试。 将同时使用放射性示踪剂、分子生物学、免疫化学和荧光显微镜技术来满足该提案的具体目标。这些是 i.) 通过脉络丛介导胆碱跨脑脊液血屏障转运的细胞机制的表征； ii.) 热休克蛋白 Hsp27 在轻度热应激后快速诱导胆碱转运调节中的作用特征，iii) 检查热应激诱导的脉络丛胆碱转运热保护。 大脑中游离胆碱水平的缺乏或增加与儿童中枢神经发育和中枢神经疾病有关，例如阿尔茨海默病、脑缺血和成人中枢有机磷神经氧化。 因此，更好地了解药物胆碱跨脑脊液-血液屏障转运的能量和调节将有助于更有效地预防、管理和治疗此类疾病。