Chronic Alcohol, Dementia, and CNS Fluid Homeostasis

项目概要/摘要 中年酒精使用障碍（AUD）是老年痴呆症的重要独立预测因素， 血管性认知障碍和痴呆（VCID），包括常见亚型脑淀粉样蛋白 淀粉样β蛋白（A β）沉积于脑血管是一种脑血管病（CAA）。仅仅十年， 从2005年至2014年，老年人酗酒率总体上升了20%，仅女性就上升了50%。的 酒精对中枢神经系统（CNS）毒性作用的机制尚不完全清楚 这就限制了旨在减少或预防重工业国家疾病负担的战略的制定。 有无CAA VCID的饮酒者。酒精对中枢神经系统的损害作用的一个根本原因是 了解CNS液体稳态失调。初步证据表明，与酒精有关的 异常的流体稳态表现为脑室扩大和CSF流动动力学改变。在 特别是人类，这表现为侧脑室扩大，不仅反映了组织损失， 本身也会导致组织损伤和认知障碍。我们认为乙醇破坏了 液体稳态的基本原理，通过减少CSF流经相互连接的胶质淋巴和淋巴 通过生物化学和神经免疫改变，从而直接损害组织。的 胶质淋巴/淋巴系统的功能支持流体稳态，并清除废物和毒素， 个脑袋我们提出的研究包括一系列全面的实验，以定量分析酒精的 对正常脑中CSF分泌、胶质淋巴和淋巴转运以及CSF/淋巴"组学"分析的影响 和CAA VCID病理学在目标1中，我们将确定cEtoh如何干扰大鼠CSF分泌 有/无VCID，使用新型MRI采集方法测量脉络膜CSF分泌以及血液 脉络丛和皮质的灌注。我们还将实施MRI序列来测量大脑 在有/无VCID的cEtoh暴露大鼠中进行形态测量，并对CSF、脑膜和脑组织进行样本研究 病理学和生化淋巴和炎症因子。在目标2中，我们将评估cEtoh如何影响 胶质-淋巴转运、脑和脑膜淋巴病理学、淋巴废物输出和 有/无VCID的大鼠的认知。我们将使用动态对比增强MRI和计算流体 动力学，以测量CSF流动动力学、胶质淋巴转运和淋巴废物引流， cEtoh和VCID，以及CAA病理学和认知能力下降。在目标3中，我们将研究cEtoh如何妥协 CSF和淋巴液中的生化信号和生物物理变化，包括调节体液的蛋白质 体积（肾素-血管紧张素）和在离子转运/信号传导（电压依赖性钙信号， V型质子ATP酶和碳酸酐酶）。我们识别的分子途径可以在以后进行探测 治疗益处。

Project Summary/Abstract Alcohol use disorder (AUD) in mid-life is a significant, independent predictor of late-life dementia, particularly vascular cognitive impairment and dementia (VCID) that includes the common subtype cerebral amyloid angiopathy (CAA) characterized by deposits of amyloid-β (Aβ) in the cerebral vasculature. In only one decade, from 2005-2014, the rate of alcohol binging among the elderly rose 20% overall and by 50% in women only. The mechanisms underlying alcohol’s toxic effects on the central nervous system (CNS) remain incompletely understood, which limits the development of strategies targeted to reduce or prevent disease burden in heavy drinkers with and without CAA VCID. An underlying cause of alcohol’s damaging effects on the CNS is a poorly understood dysregulation of CNS fluid homeostasis. Preliminary evidence indicates that alcohol-associated abnormal fluid homeostasis manifests as enlarged cerebral ventricles and altered CSF flow dynamics. In humans, specifically, this manifests as lateral ventricular enlargement, and may reflect not only tissue loss but also itself be contributing to tissue damage and cognitive impairment. We propose that ethanol disrupts fundamentals of fluid homeostasis, by reducing CSF flow through the interconnected glymphatic and lymphatic systems, through biochemical and neuroimmune alterations thereby directly damaging the tissue. The functioning of glymphatic/lymphatic system supports fluid homeostasis and clears waste and toxins from the brain. Our proposed studies include a comprehensive series of experiments to quantitatively analyze alcohol’s effects on CSF secretion, glymphatic and lymphatic transport, and CSF/lymph ‘omics’ profiling in normal brain and with CAA VCID pathology. In Aim 1, we will determine how cEtoh interferes with CSF secretion in rats with/without VCID, using a novel MRI acquisition method to measure choroidal CSF secretion, as well as blood perfusion of the choroid plexus and cortex. We will also implement MRI sequences to measure brain morphometry in cEtoh-exposed rats with/without VCID and sample CSF, the meninges, and brain tissue to study pathology and biochemical lymphatic and inflammatory factors. In Aim 2, we will assess how cEtoh affects glymphatic-lymphatic transport, cerebral and meningeal lymphatic pathology, lymphatic waste output and cognition in rats with/without VCID. We will use dynamic contrast-enhanced MRI and computational fluid dynamics to measure CSF flow dynamics, glymphatic transport, and lymphatic waste drainage as affected by cEtoh and VCID, as well on CAA pathology and cognitive decline. In Aim 3 we will study how cEtoh compromises biochemical signaling and bio-physical changes in the CSF and lymph, including proteins that regulate fluid volume (renin-angiotensin) and proteins functioning in ion transport/signaling (Voltage dependent calcium signal, V-type proton ATPase and Carbonic Anhydrase). Molecular pathways that we identify can later be probed for therapeutic benefit.