New tools for understanding the blood brain barrier

了解血脑屏障的新工具

• 批准号: 8754153
• 负责人: CHENGHUA GU
• 金额: $ 84.75万
• 依托单位: HARVARD MEDICAL SCHOOL
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-30 至 2019-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8754153
• 关键词: Address; Alzheimer' s Disease; Blood - brain barrier anatomy; Blood Vessels; Brain Neoplasms; Central Nervous System Diseases; Chemicals; Controlled Environment; Cues; Development; Disease; Drug Delivery Systems; Endothelial Cells; Endothelium; Environment; Gene Expression Profile; Genetic; In Vitro; Knowledge; Lead; Maps; Molecular; Monitor; Multiple Sclerosis; Nerve Degeneration; Nervous system structure; Neuraxis; Neurologic; Optics; Parkinson Disease; Pathway interactions; Peripheral; Pharmaceutical Preparations; Pharmacologic Substance; Process; Property; Public Health; Regulation; Research; Research Personnel; Resolution; Role; Route; Stem cells; Stroke; Synaptic Transmission; System; Techniques; Therapeutic; Therapeutic Agents; Tight Junctions; Time; Toxin; Vascular System; base; in vitro Model; in vivo; nervous system disorder; neuroinflammation; novel; pathogen; prevent; reconstitution; relating to nervous system; restoration; tool; transcytosis

DESCRIPTION (provided by applicant): The central nervous system (CNS) requires a tightly controlled environment free of toxins and pathogens to provide the proper chemical conditions for synaptic transmission. This environment is maintained by the 'blood brain barrier' (BBB), which is composed of highly specialized blood vessels whose endothelium display specialized tight junctions and unusually low rates of transcellular vesicular transport (transcytosis). While BBB breakdown has recently been associated with various neurological disorders, an intact BBB also poses a major obstacle for drug delivery to the CNS. Pharmaceutical companies spend billions of dollars to develop drugs that can penetrate the BBB to treat disease. However, little progress has been made on manipulating the BBB due to a significant knowledge gap in understanding how BBB function is regulated and identifying the essential molecular constituents governing its processes. This limited understanding has also thwarted our ability to therapeutically manipulate the BBB. The major impediment to understanding the BBB is identifying its essential constituent and unraveling the mechanism by which these key regulators control BBB function. However, the current in vitro models rely on fully differentiated endothelial cells, which already contain unique properties that prevent their use in reconstitution studies. Similarly, the main technique to study the BBB has been EM, however its static snapshots do not provide information on active and dynamic vesicular transport, directionality, or their specifi routes to allow investigators to interrogate the key molecular mechanisms that regulate BBB integrity. Recently, with our research background in developmental co-wiring of nervous and vascular systems, we used the traditional developmental approach, to first mapped the precise timing of BBB formation and then identified neural cues that induce CNS endothelium to acquire BBB properties, and molecules with possible roles in BBB function from simple transcriptome comparisons between CNS and peripheral endothelial cells. Surprisingly, we also found that instead of a physical buildup or disruption of structurally important tight junctions as previously thought, transcytosis regulation seems to be the more likely the major mechanism underlying BBB integrity. In characterizing these developmental properties, I realized that these findings are just the tip of the iceberg and that truly fundamental questions remain in identifying the core pathway and understand how they regulate BBB function. New tools thus are needed for understanding the BBB. Here we propose first to develop a new stem cell-based system to allow reconstitution of a functional BBB in vitro, and then to develop a genetic-optical system for monitoring the functional integrity of the BBB in vivo at subcellular resolution in real time. This integrated approach will address fundamental questions about the regulation of the BBB, which will then lead to more effective therapeutic strategies and specific targets for BBB restoration and manipulation.

描述（由申请人提供）：中枢神经系统（CNS）需要一个严格控制的环境，没有毒素和病原体，为突触传递提供适当的化学条件。这种环境是由“血脑屏障”（BBB）维持的，它由高度特化的血管组成，其内皮显示出特化的紧密连接和异常低的跨细胞囊泡运输率（胞饮）。虽然血脑屏障的破坏最近与各种神经系统疾病有关，但血脑屏障的完整也对药物递送到中枢神经系统构成了主要障碍。制药公司花费数十亿美元开发能够穿透血脑屏障治疗疾病的药物。然而，由于在了解血脑屏障功能如何调节和识别控制其过程的基本分子成分方面存在重大知识差距，因此在操纵血脑屏障方面取得的进展很少。这种有限的理解也阻碍了我们在治疗上操纵血脑屏障的能力。了解血脑屏障的主要障碍是确定其基本成分并揭示这些关键调节因子控制血脑屏障功能的机制。然而，目前的体外模型依赖于完全分化的内皮细胞