Unhealthy ageing and memory loss associated with vascular insufficiency

与血管供血不足相关的不健康衰老和记忆丧失

• 批准号: 2746412
• 金额: --
• 依托单位: University of Nottingham
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2022
• 资助国家: 英国
• 起止时间: 2022 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2746412
• 关键词: Unhealthy; ageing; memory; loss; associated

Perivascular astrocytes are abundant in the brain and form a physical bridge between neurons and blood vessels. In addition, astrocytes control neurovascular coupling that serves to match local cerebral blood flow to regional neuronal energy use and ensures normal functioning of the brain. Vascular insufficiency takes place over several years without any obvious clinical symptoms and could be exacerbated by environmental stress or lifestyle choices (Ritchie et al. 2001). Astrocytes in particular respond to endothelial cell activation that arises from vascular insufficiency, and collectively these processes have a huge impact on brain function as we age. Recently, we have shown that when astrocytes react to pathological changes, they have dysregulated oxidative and nitric oxide pathways and this prevents astrocytes to regulate neurovascular coupling accordingly (Sarmiento et al. 2020). Therefore, we seek to further investigate the link between compromised energy resources and perivascular brain cells to better understand how neurovascular coupling may be affected and predispose the brain to damage and reduced function during unhealthy ageing. 1) You will be trained to optimise the culture of brain cells and/or brain slices from postnatal and adult mice. This is called primary culture, and it is an essential laboratory technique that requires a high level of skill. Subsequently, you will be trained to investigate the effects of oxygen-glucose deprivation (OGD). This is an experimental model of environmental stress that mimics what happens in the brain when there are insufficient nutrients, which may occur as a result of vascular insufficiency associated with age and may be compounded by lifestyle. You will be trained to assess the reactivity and health of astrocytes and endothelial cells (i.e., blood vessels) using specific cell markers (e.g., GFAP, STAT3, angiopoietin-2, CD-31), as well as signalling pathways associated with neurovascular coupling in the same cells (vasoactive molecules such as COX-1, iNOS, 20-HETE). In addition, electrophysiological measurements of endothelial and astrocytic functions in conjunction with measurements of intracellular calcium (Fura 2) and nitric oxide (DAF-FM) will be correlated to changes in cell markers and signalling pathways in the same environment stress.2) Following characterisation of astrocytic responses to ODG, you will use the optimised in vitro protocols to culture perivascular cells and/or brain slices from a mouse model that recapitulates features of vascular insufficiency such as endothelial activation, neuroinflammation and memory deficits (Boehm-Sturm et al. 2017, Stroke). This is a surgical model, and the possibility exists to be trained in animal handling and surgical procedures if you desire. Brain regions will be isolated for the culture of primary cells and/or slices to examine changes in the molecular pathways involved in response to vascular insufficiency as the next step in the translational pipeline. We hypothesise that the astrocytes will be primed towards a reactive phenotype as a result of the surgical procedure, and this will allow us to investigate molecular mechanisms that underpin this and may be amenable to treatment. Our groups have been working with several compounds that influence oxidative stress pathways in the brain, and these will be examined in the cultured cells, potentially in conjunction with further threshold manipulations of OGD with neuroprotective drugs. 3) Ultimately, compounds that provide benefit for the tissue culture could be tested in the same surgical mouse model. Functional outcomes will be assessed at the whole organism level using either magnetic resonance imaging (MRI) (which could include training in computational image analysis) or behaviour testing (depending on funding, and preferences of the student). However, mechanistic insight into the compound's efficacy will be confirmed using histology, and molecular biology techniques.

血管周围星形胶质细胞在大脑中丰富，并形成神经元和血管之间的物理桥梁。此外，星形胶质细胞控制神经血管偶联，用于使局部脑血流与区域神经元能量使用相匹配，并确保大脑的正常功能。血管功能不全持续数年，没有任何明显的临床症状，并且可能因环境压力或生活方式选择而加重（里奇等人，2001）。特别是星形胶质细胞对血管功能不全引起的内皮细胞激活做出反应，随着年龄的增长，这些过程对大脑功能产生巨大影响。最近，我们已经表明，当星形胶质细胞对病理变化做出反应时，它们会出现氧化和一氧化氮通路失调，这会阻止星形胶质细胞相应地调节神经血管偶联（Sarmiento et al. 2020）。因此，我们寻求进一步研究受损的能量资源和血管周围脑细胞之间的联系，以更好地了解神经血管耦合如何受到影响，并使大脑在不健康的衰老过程中容易受损和功能下降。1)您将接受培训，以优化出生后和成年小鼠的脑细胞和/或脑切片的培养。这就是所谓的原代培养，这是一个基本的实验室技术，需要高水平的技能。随后，您将接受培训，以研究氧葡萄糖剥夺（OGD）的影响。这是一个环境压力的实验模型，模拟了当营养不足时大脑中发生的事情，这可能是由于与年龄相关的血管功能不全而发生的，并且可能因生活方式而加剧。您将接受培训，以评估星形胶质细胞和内皮细胞的反应性和健康状况（即，血管）使用特定的细胞标记（例如，GFAP、STAT 3、血管生成素-2、CD-31），以及与相同细胞中的神经血管偶联相关的信号传导途径（血管活性分子，如考克斯-1、iNOS、20-HETE）。此外，内皮和星形胶质细胞功能的电生理学测量连同细胞内钙（Fura 2）和一氧化氮（DAF-FM）的测量将与相同环境应激中细胞标志物和信号传导途径的变化相关。2）在表征星形胶质细胞对ODG的反应之后，您将使用优化的体外方案从小鼠模型中培养血管周围细胞和/或脑切片，该模型重现了血管功能不全的特征，如内皮激活，神经炎症和记忆缺陷（Boehm-Sturm et al. 2017，Stroke）。这是一个外科手术模型，如果你愿意，你可以接受动物处理和外科手术的培训。将分离脑区域用于培养原代细胞和/或切片，以检查作为翻译管道中下一步的血管功能不全反应所涉及的分子途径的变化。我们假设星形胶质细胞将作为手术过程的结果而被引导朝向反应性表型，这将使我们能够研究支持这一点的分子机制，并且可能适合于治疗。我们的团队一直在研究影响大脑中氧化应激途径的几种化合物，这些化合物将在培养的细胞中进行检查，可能与神经保护药物对OGD的进一步阈值操作结合起来。3)最终，可以在相同的外科小鼠模型中测试为组织培养提供益处的化合物。将使用磁共振成像（MRI）（可能包括计算图像分析培训）或行为测试（取决于资金和学生的偏好）在整个生物体水平上评估功能结果。然而，将使用组织学和分子生物学技术来证实对化合物功效的机理见解。