The role of ATP13A5 ATPase in determining blood-brain pericyte functions

摘要 血脑屏障（BBB）提供限制循环病原体进入的物理屏障， 环境毒素、免疫细胞和人体代谢废物进入中枢神经系统（CNS）; 它还为大脑提供关键的能量代谢物，如葡萄糖和乳酸盐，必需氨基酸，脂肪酸， 酸和维生素，以及调节分子和生长激素通过选择性运输系统。BBB的 还有助于清除大脑自身的代谢废物，包括过量的神经递质和蛋白质 分子，如阿尔茨海默氏症的淀粉样蛋白-β物种（Aβ），为神经元提供严格控制的 微环境我们从神经退行性疾病药物开发失败中吸取的教训 近年来，疾病导致我们重新审视BBB，不仅是因为它对CNS疾病的贡献， 阿尔茨海默氏病和相关痴呆症（ADRD），而且还绕过了药物输送这一可怕的障碍。 答案可能在于使BBB与其他BBB从根本上不同的生物学机制。 血管系统的一部分。因此，当前提案的主要目标是确定遗传 将BBB与非BBB血管系统分开的标志物，并描述了 潜在地驱动动物模型中BBB的特化和维持。 已知脑内皮细胞通过紧密连接形成更紧密密封的屏障，并消除 转胞吞作用它们还与星形胶质细胞和血管周围壁细胞密切相互作用， 特殊的血管周围结构，如基底膜，周细胞覆盖和星形胶质细胞终足。 近世纪以来，人们已经知道，即使在大脑中，血管细胞也是异质的，并且一些血管细胞在大脑中也是异质的。 脑区域不受BBB保护，特别是脑室周围器官（CVO）。然而， 标记物或遗传工具可用于我们可靠地识别和分离BBB和非BBB血管系统。 使用单细胞转录组学和数据挖掘，我们已经确定了标记，并产生了新的转基因 用于分离BBB和非BBB血管细胞的工具。因此，我们建议进一步确定 脑内皮细胞和周细胞的异质性。我们的初步数据表明，Atp 13 a5是唯一的， 脑周细胞和必要的血脑屏障的完整性，我们假设，Atp 13 a5是获得脑周细胞在 血脑屏障特化，并要求周细胞的作用，加强血脑屏障，特别是在老化和阿尔茨海默氏症 疾病我们计划在体外分子和细胞水平上确定其生物学功能，并在体内使用 一个迷人的模特我们希望新的标记物和工具将有助于我们更好地了解大脑 BBB功能背景下的血管生物学和异质性，以及它们对CNS的贡献 疾病，例如，ADRD。

Abstract The blood-brain barrier (BBB) provides a physical barrier limiting the entrance of circulating pathogens and environmental toxins, immune cells and body’s metabolic waste products into the central nervous system (CNS); it also supplies the brain with critical energy metabolites such as glucose and lactate, essential amino acids, fatty acids and vitamins, and regulatory molecules and growth hormones via selective transport systems. The BBB also helps clear brain’s own metabolic wastes including excess of neurotransmitters and proteinaceous molecules such as Alzheimer’s amyloid-β species (Aβ), providing neurons with a tightly controlled microenvironment. The lessons we learned from the failures of drug development for the neurodegenerative diseases have led us to revisit the BBB in recent years, not only for its contribution to CNS diseases such as Alzheimer’s disease and related dementia (ADRD), but also to circumvent this formidable barrier for drug delivery. The answers may remain in the biological mechanisms that make the BBB fundamentally different from other parts of the vascular system. Therefore, the major goal of the current proposal is to determine the genetic marker(s) that separates the BBB from non-BBB vascular system, and delineate a molecular mechanism that potentially drives the specialization and maintenance of the BBB in animal models. Brain endothelial cells are known to form a more tightly sealed barrier through tight junctions and eliminating transcytosis. They are also in close interactions with astrocytes and perivascular mural cells, resulting in specialized perivascular structures such as the basement membrane, pericyte coverage and astrocytic endfeet. It has been known for nearly a century that vascular cells are heterogeneous even within the brain, and several brain regions are not protected by the BBB, particular the circumventricular organs (CVOs). However, no good marker or genetic tool is available for us to reliably identify and separate the BBB and non-BBB vascular system. Using single cell transcriptomics and data mining, we have identified markers and generated new transgenic tools for separating BBB and non-BBB vascular cells. Therefore, we propose to further determine the heterogeneity of brain endothelial cells and pericytes. As our preliminary data indicate that Atp13a5 is unique to brain pericytes and essential for BBB integrity, we hypothesize that Atp13a5 is acquired by brain pericytes during BBB specialization, and required for pericyte’s role in fortifying the BBB, particularly in aging and Alzheimer’s disease. We plan to determine its biological functions in vitro at molecular and cellular levels, and in vivo using a knockout model. We hope that the new marker and tools will help us to achieve a better understanding of brain vascular biology and heterogeneity in the context of BBB functions, as well as their contributions to CNS disorders, e.g., ADRD.