Institute for Nanobiotechnology, Johns Hopkins University, Baltimore, MD, United States; Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, United States.
Institute for Nanobiotechnology, Johns Hopkins University, Baltimore, MD, United States; Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, MD, United States.
Biomaterials. 2019 Jan;190-191:24-37. doi: 10.1016/j.biomaterials.2018.10.023. Epub 2018 Oct 25.
Microvessels of the blood-brain barrier (BBB) regulate transport into the brain. The highly specialized brain microvascular endothelial cells, a major component of the BBB, express tight junctions and efflux transporters which regulate paracellular and transcellular permeability. However, most existing models of BBB microvessels fail to exhibit physiological barrier function. Here, using (iPSC)-derived human brain microvascular endothelial cells (dhBMECs) within templated type I collagen channels we mimic the cylindrical geometry, cell-extracellular matrix interactions, and shear flow typical of human brain post-capillary venules. We characterize the structure and barrier function in comparison to non-brain-specific microvessels, and show that dhBMEC microvessels recapitulate physiologically low solute permeability and quiescent endothelial cell behavior. Transcellular permeability is increased two-fold using a clinically relevant dose of a p-glycoprotein inhibitor tariquidar, while paracellular permeability is increased using a bolus dose of hyperosmolar agent mannitol. Lastly, we show that our human BBB microvessels are responsive to inflammatory cytokines via upregulation of surface adhesion molecules and increased leukocyte adhesion, but no changes in permeability. Human iPSC-derived blood-brain barrier microvessels support quantitative analysis of barrier function and endothelial cell dynamics in quiescence and in response to biologically- and clinically-relevant perturbations.
血脑屏障(BBB)的微血管调节着向大脑的物质转运。高度特化的脑微血管内皮细胞是 BBB 的主要组成部分,其表达紧密连接和外排转运蛋白,调节细胞旁和细胞内通透性。然而,大多数现有的 BBB 微血管模型都未能表现出生理屏障功能。在这里,我们在模板化的 I 型胶原通道内使用(iPSC)衍生的人脑微血管内皮细胞(dhBMEC)模拟了人脑中后微静脉的圆柱状几何形状、细胞-细胞外基质相互作用和剪切流。我们将其结构和屏障功能与非脑特异性微血管进行了比较,并表明 dhBMEC 微血管再现了生理上低溶质通透性和静止的内皮细胞行为。使用临床相关剂量的 P-糖蛋白抑制剂他利喹达,跨细胞通透性增加了两倍,而使用高渗剂甘露醇的脉冲剂量,细胞旁通透性增加。最后,我们表明,我们的人 BBB 微血管通过表面黏附分子的上调和白细胞黏附的增加对炎症细胞因子做出反应,但通透性没有变化。人类 iPSC 衍生的血脑屏障微血管支持在静止和响应于生物和临床相关干扰时对屏障功能和内皮细胞动力学进行定量分析。