Background Alzheimer’s disease (AD) is the most common form of neurodegenerative disease. It is an irreversible condition marked by irreversible cognitive loss, commonly attributed to the loss of hippocampal neurons due to the formation of senile plaques and neurofibrillary tangles. Although the sporadic form is the most prevalent, the presence of familial form (involving several genes such as APP, PSEN1, and PSEN2) of the disease is commonly used as a model for understanding the pathophysiology of the disease. The aim of this study is to investigate the effect of a mutation on PSEN1 and PSEN2 genes on the BBB function using induced pluripotent stem cells (iPSCs). Methods iPSC lines from patients suffering from a familial form of Alzheimer’s disease and harboring mutations in PSEN1 or PSEN2 were used in this study and compared to a control iPSC line. Cells were differentiated into brain microvascular endothelial cells (BMECs) following established differentiation protocols. Barrier function was assessed by measuring TEER and fluorescein permeability, drug transporter activity was assessed by uptake assay, glucose uptake and metabolism assessed by cell flux analyzer, mitochondrial potential by JC-1, and lysosomal acidification by acridine orange. Results iPSC-derived BMECs from the FAD patient presenting a mutation in the PSEN1 gene showed impaired barrier function compared to the FAD patient harboring a mutation in PSEN2 and to the control group. Such impaired barrier function correlated with poor tight junction complexes and reduced drug efflux pump activity. In addition, both PSEN1 and PSEN2-BMECs displayed reduced bioenergetics, lysosomal acidification, autophagy, while showing an increase in radical oxygen species (ROS) production. Finally, PSEN1- and PSEN2-BMECs showed an elevated secretion of Aβ1–40 peptides compared to control-BMECs. Conclusions Our study reports that iPSC-derived BMECs obtained from FAD patients showed impaired barrier properties and BMEC metabolism. In particular, mutation in the PSEN1 gene was associated with a more detrimental phenotype than mutation in PSEN2 , as noted by a reduced barrier function, reduced drug efflux pump activity, and diminished glucose metabolism. Therefore, assessing the contribution of genetic mutations associated with Alzheimer’s disease will allow us to better understand the contribution of the BBB in dementia, but also other neurodegenerative diseases.

中文翻译：

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PSEN1 或 PSEN2 基因突变的存在与体外脑内皮细胞表型受损有关

背景 阿尔茨海默病 (AD) 是最常见的神经退行性疾病。这是一种不可逆的病症，以不可逆的认知丧失为标志，通常归因于老年斑和神经原纤维缠结的形成导致海马神经元的丧失。虽然散发形式是最普遍的，但该疾病的家族形式（涉及多种基因，如 APP、PSEN1 和 PSEN2）的存在通常用作了解该疾病病理生理学的模型。本研究的目的是使用诱导多能干细胞 (iPSC) 研究 PSEN1 和 PSEN2 基因突变对 BBB 功能的影响。方法 本研究使用来自患有家族性阿尔茨海默病并携带 PSEN1 或 PSEN2 突变的患者的 iPSC 系，并与对照 iPSC 系进行比较。按照既定的分化方案，将细胞分化为脑微血管内皮细胞 (BMEC)。通过测量 TEER 和荧光素渗透性来评估屏障功能，通过摄取测定评估药物转运蛋白活性，通过细胞通量分析仪评估葡萄糖摄取和代谢，通过 JC-1 评估线粒体潜力，通过吖啶橙进行溶酶体酸化。结果与携带 PSEN2 突变的 FAD 患者和对照组相比，来自呈现 PSEN1 基因突变的 FAD 患者的 iPSC 衍生的 BMEC 显示屏障功能受损。这种受损的屏障功能与不良的紧密连接复合物和降低的药物外排泵活性相关。此外，PSEN1 和 PSEN2-BMECs 都显示出生物能学、溶酶体酸化、自噬减少，同时显示自由基氧 (ROS) 产生增加。最后，与对照 BMECs 相比，PSEN1-和 PSEN2-BMECs 显示出 Aβ1-40 肽的分泌增加。结论我们的研究报告称，从 FAD 患者获得的 iPSC 衍生的 BMEC 显示出屏障特性和 BMEC 代谢受损。特别是，与 PSEN2 突变相比，PSEN1 基因突变与更有害的表型相关，如屏障功能降低、药物外排泵活性降低和葡萄糖代谢降低所表明的那样。所以，