Calvo-Flores Guzmán Beatriz, Elizabeth Chaffey Tessa, Hansika Palpagama Thulani, Waters Sarah, Boix Jordi, Tate Warren Perry, Peppercorn Katie, Dragunow Michael, Waldvogel Henry John, Faull Richard Lewis Maxwell, Kwakowsky Andrea
Centre for Brain Research, Department of Anatomy and Medical Imaging, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand.
Centre for Brain Research, NeuroDiscovery Behavioural Unit, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand.
Front Mol Neurosci. 2020 Nov 2;13:522073. doi: 10.3389/fnmol.2020.552073. eCollection 2020.
Alzheimer's disease (AD), the most common chronic neurodegenerative disorder, has complex neuropathology. The principal neuropathological hallmarks of the disease are the deposition of extracellular β-amyloid (Aβ) plaques and neurofibrillary tangles (NFTs) comprised of hyperphosphorylated tau (p-tau) protein. These changes occur with neuroinflammation, a compromised blood-brain barrier (BBB) integrity, and neuronal synaptic dysfunction, all of which ultimately lead to neuronal cell loss and cognitive deficits in AD. Aβ was stereotaxically administered bilaterally into the CA1 region of the hippocampi of 18-month-old male C57BL/6 mice. This study aimed to characterize, utilizing immunohistochemistry and behavioral testing, the spatial and temporal effects of Aβ on a broad set of parameters characteristic of AD: p-tau, neuroinflammation, vascular pathology, pyramidal cell survival, and behavior. Three days after Aβ injection and before significant neuronal cell loss was detected, acute neuroinflammatory and vascular responses were observed. These responses included the up-regulation of glial fibrillary acidic protein (GFAP), cell adhesion molecule-1 (PECAM-1, also known as CD31), fibrinogen labeling, and an increased number of activated astrocytes and microglia in the CA1 region of the hippocampus. From day 7, there was significant pyramidal cell loss in the CA1 region of the hippocampus, and by 30 days, significant localized up-regulation of p-tau, GFAP, Iba-1, CD31, and alpha-smooth muscle actin (α-SMA) in the Aβ-injected mice compared with controls. These molecular changes in Aβ-injected mice were accompanied by cognitive deterioration, as demonstrated by long-term spatial memory impairment. This study is reporting a comprehensive examination of a complex set of parameters associated with intrahippocampal administration of Aβ in mice, their spatiotemporal interactions and combined contribution to the disease progression. We show that a single Aβ injection can reproduce aspects of the inflammatory, vascular, and p-tau induced pathology occurring in the AD human brain that lead to cognitive deficits.
阿尔茨海默病(AD)是最常见的慢性神经退行性疾病,具有复杂的神经病理学特征。该疾病的主要神经病理学标志是细胞外β淀粉样蛋白(Aβ)斑块的沉积以及由过度磷酸化的tau(p-tau)蛋白组成的神经原纤维缠结(NFTs)。这些变化伴随着神经炎症、血脑屏障(BBB)完整性受损以及神经元突触功能障碍,所有这些最终都会导致AD患者的神经元细胞丢失和认知缺陷。将Aβ立体定向双侧注射到18月龄雄性C57BL/6小鼠海马体的CA1区域。本研究旨在利用免疫组织化学和行为测试,表征Aβ对一系列广泛的AD特征参数的时空影响:p-tau、神经炎症、血管病理学、锥体细胞存活和行为。在Aβ注射后三天且在检测到明显的神经元细胞丢失之前,观察到了急性神经炎症和血管反应。这些反应包括胶质纤维酸性蛋白(GFAP)、细胞粘附分子-1(PECAM-1,也称为CD31)、纤维蛋白原标记的上调,以及海马体CA1区域中活化星形胶质细胞和小胶质细胞数量的增加。从第7天开始,海马体CA1区域出现明显的锥体细胞丢失,到30天时,与对照组相比,注射Aβ的小鼠中p-tau、GFAP、Iba-1、CD31和α平滑肌肌动蛋白(α-SMA)出现明显的局部上调。注射Aβ的小鼠中的这些分子变化伴随着认知能力的下降,长期空间记忆受损证明了这一点。本研究报告了对与小鼠海马体内注射Aβ相关的一组复杂参数、它们的时空相互作用以及对疾病进展的综合贡献的全面检查。我们表明,单次注射Aβ可以重现AD人类大脑中发生的炎症、血管和p-tau诱导的病理学方面,这些病理学导致认知缺陷。