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

摘要/摘要 阿尔茨海默病(AD)患者的脑微血管发生改变，但几乎没有方法可以 检查活组织中的细胞过程。存活的脑微血管(MV)可以从 在威斯康星州进行快速尸检(尸检12小时)的受试者的整个脑组织 神经病理学(NP)核心。威斯康星大学NP核心中心的捐赠者被诊断为 痴呆症或非痴呆症，所有大脑标本都进行了广泛的神经病理检查 评估。这项提议利用创新的方法来快速获得和维护可存活的大脑 MV在标准组织培养条件下，在支持性液体培养基中至少培养5天， 这为研究阿尔茨海默病患者和非阿尔茨海默病患者大脑中的微血管系统提供了一个独特的机会。 MV结构和组成的许多方面促成了与以下内容相关的交互 广告。对于此R03，重点放在管腔表面和初始的两个组件上 脑与体循环的接口：1)脑微血管内皮细胞 细胞(BEC)，2)糖萼，一种动态的细胞外基质(ECM)凝胶层 BEC的管腔表面。 以下两个假设将得到检验。首先，痴呆症患者的MV有类似的 BEC特异性活性和整体代谢活性，但衰老BEC患病率增加 相对于非痴呆者的MV。第二，痴呆症患者的MV较大 与MV相比，糖萼脱落反映了降解酶的增加。 没有痴呆症。样本和结果测量将根据临床情况进行初步检查 诊断为痴呆症或非痴呆症，然后根据随后的详细情况重新分类 神经病理学标准。 目标1将定义BEC与痴呆症和非痴呆症MV样本在以下方面的区别 对BEC特异性活性、整体代谢活性和BEC衰老进行结果测量。 目标2将确定痴呆症和非痴呆症MV在新的阶段有何不同 细胞外基质的合成及其降解标记物。糖萼的研究将集中在肝素上 硫酸盐蛋白多糖(HSPGs)和透明质酸(HA)。所获得的知识将提供 为可行的、具有治疗性的干扰/干预实验奠定基础 对缓解痴呆症患者有害MV改变的启示。

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.