STRESS MODULATION OF CHOLINE TRANSPORT BY CHOROID PLEXUS

脉络丛胆碱运输的应激调节

• 批准号: 6032689
• 负责人: Alice Renee Villalobos
• 金额: $ 5.03万
• 依托单位: UNIVERSITY OF CONNECTICUT STORRS
• 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 2000-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6032689
• 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，以预测内源性和异种生物有机阳离子在整个脑脊液（CSF）闭孔屏障中介导的内源性和异种生物有机阳离子的转运的实验系统。 这项拟议的研究的直接目的是表征脉络丛上皮的作用，该脉络丛上皮的作用包括心室CSF屏障在中枢神经系统中胆碱水平调节。 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途径的神经递质对行为的神经控制至关重要的，例如睡眠 - 饮用循环循环和学习或记忆。 胆碱的可用性是乙酰胆碱合成的速率限制，对于新生儿的正常脑发育至关重要。 拟议的研究将检验以下假设：胆碱是在心室CSF血液屏障上积极运输的，因此，药理和生理化学应力对这种主动运输过程的调节可能会改变胆碱的大脑水平。 该假设将直接使用从新生大鼠分离的脉络膜上皮细胞的原发性培养系统进行检验。 放射性示例，分子生物学，免疫化学和荧光显微镜技术将同时使用该提案的特定目的。这些是i。）细胞机制的表征，这些机制通过脉络丛介导胆碱横穿CSF血液屏障的胆碱转运； ii。）热休克蛋白Hsp27在轻度热压力后快速诱导胆碱转运的调节的表征，iii）检查热应激诱导的脉络丛胆碱转运的热应诱导的热保护。 大脑中游离胆碱水平的缺陷与儿童和中枢神经疾病的中枢神经发育有关，例如阿尔茨海默氏病，大脑缺血和中央有机磷酸盐神经毒性的成人。 因此，对跨CSF血液屏障的胆碱运输的能量和调节将有更有效的预防，管理和治疗此类疾病的能量和调节。