The Microvasculature in Alzheimer’s Disease: Viable Microvessels for Studies of Brain Endothelial and Glycocalyx Health

摘要/总结 阿尔茨海默病（AD）的脑微血管系统发生改变，但很少有方法可以 检查活组织中的细胞过程。活脑微血管（MV）可以从 在华盛顿大学进行快速尸检（死后<12小时）的受试者的全脑组织 神经病理学（NP）核心。UW NP核心中的供体受试者具有以下临床诊断： 痴呆或无痴呆，所有脑标本均接受广泛的神经病理学检查， 考核该提案利用创新的方法快速获得和维持可行的大脑 MV在标准组织培养条件下在支持性液体培养基中培养至少5天， 这提供了一个独特的机会，研究微血管系统在大脑与非AD。 MV结构和组成的许多方面有助于与以下相关的相互作用： AD.对于该R 03，重点是管腔表面和初始的2个组件 脑与体循环之间的界面：1）脑微血管内皮 细胞（BEC），和2）糖萼，细胞外基质（ECM）的动态凝胶样层， BEC的管腔表面。 将检验以下2个假设。首先，痴呆症患者的MV有类似的 BEC特异性活力和总体代谢活性，但衰老BEC的患病率增加 相对于没有痴呆症的人的MV。其次，痴呆症患者的MV 糖萼脱落，这反映了增加的降解酶，相对于MV从那些 没有痴呆。样本和结局指标将根据临床 诊断为痴呆或无痴呆，然后根据随后的详细情况重新分类 神经病理学标准。 目的1将定义来自痴呆和非痴呆MV标本的BEC在以下方面的差异： BEC特异性活力、总体代谢活性和BEC衰老的结果测量。 目的2将确定痴呆和非痴呆MV的糖萼在新生时有何不同。 ECM的合成和ECM降解的标志物。糖萼的研究将集中在乙酰肝素上 硫酸蛋白聚糖（HSPG）和透明质酸（HA）。获得的知识将提供 干扰/干预实验的基础是可行的，并具有治疗作用 对缓解痴呆症的有害MV变化的影响。

ABSTRACT/SUMMARY Brain microvasculature is altered in Alzheimer’s Disease (AD), but there are few methods to examine cellular processes in living tissue. Viable brain microvessels (MV) can be isolated from whole brain tissue of subjects undergoing rapid autopsy (<12 hours post mortem) in the UW Neuropathology (NP) Core. The donor subjects in the UW NP Core have a clinical diagnosis of dementia or no dementia, and all brain specimens undergo extensive neuropathologic assessment. This proposal utilizes innovative methods to rapidly obtain and maintain viable brain MV for a minimum of 5 days in supportive liquid media under standard tissue culture conditions, which affords a unique opportunity to study the microvasculature in brains with and without AD. Many aspects of MV structure and composition contribute to interactions that are relevant to AD. For this R03, the focus is on the luminal surface and the 2 components that are the initial interface between the brain and the systemic circulation: 1) the brain microvascular endothelial cell (BEC), and 2) the glycocalyx, a dynamic gel-like layer of extracellular matrix (ECM) that lines the luminal surface of BEC. The following 2 hypotheses will be tested. First, MV from those with dementia have similar BEC-specific viability and overall metabolic activity, but increased prevalence of senescent BEC relative to MV from those without dementia. Second, MV from those with dementia have greater glycocalyx shedding, which reflects increased degradative enzymes, relative to MV from those without dementia. Samples and outcome measures will be initially examined based on the clinical diagnosis of dementia or no dementia, and then re-classified according to subsequent detailed neuropathologic criteria. Aim 1 will define how BEC from dementia and no dementia MV specimens differ with respect to outcome measures of BEC-specific viability, overall metabolic activity, and BEC senescence. Aim 2 will determine how the glycocalyx from dementia and no dementia MV differ in de novo synthesis of ECM and markers of ECM degradation. Studies of glycocalyx will focus on heparan sulfate proteoglycans (HSPGs) and hyaluronan (HA). Knowledge gained will provide the foundation for perturbation/intervention experiments that are feasible, and have therapeutic implications for the mitigation of deleterious MV changes with dementia.