Institute for Nanobiotechnology, Johns Hopkins University, Baltimore, MD, USA.
Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA.
Fluids Barriers CNS. 2022 Nov 5;19(1):87. doi: 10.1186/s12987-022-00377-1.
The blood-brain barrier (BBB) plays a pivotal role in brain health and disease. In the BBB, brain microvascular endothelial cells (BMECs) are connected by tight junctions which regulate paracellular transport, and express specialized transporter systems which regulate transcellular transport. However, existing in vitro models of the BBB display variable accuracy across a wide range of characteristics including gene/protein expression and barrier function. Here, we use an isogenic family of fluorescently-labeled iPSC-derived BMEC-like cells (iBMECs) and brain pericyte-like cells (iPCs) within two-dimensional confluent monolayers (2D) and three-dimensional (3D) tissue-engineered microvessels to explore how 3D microenvironment regulates gene expression and function of the in vitro BBB. We show that 3D microenvironment (shear stress, cell-ECM interactions, and cylindrical geometry) increases BBB phenotype and endothelial identity, and alters angiogenic and cytokine responses in synergy with pericyte co-culture. Tissue-engineered microvessels incorporating junction-labeled iBMECs enable study of the real-time dynamics of tight junctions during homeostasis and in response to physical and chemical perturbations.
血脑屏障（BBB）在大脑健康和疾病中起着关键作用。在 BBB 中，脑微血管内皮细胞（BMEC）通过紧密连接连接在一起，这些连接调节细胞旁转运，并且表达专门的转运系统来调节细胞转运。然而，现有的 BBB 体外模型在包括基因/蛋白质表达和屏障功能在内的广泛特征上显示出不同的准确性。在这里，我们使用一组荧光标记的诱导多能干细胞衍生的 BMEC 样细胞（iBMEC）和脑周细胞样细胞（iPC）在二维（2D）和三维（3D）组织工程微血管中的同源家族内来探索 3D 微环境如何调节体外 BBB 的基因表达和功能。我们表明，3D 微环境（剪切力、细胞-ECM 相互作用和圆柱状几何形状）增加了 BBB 表型和内皮特性，并与周细胞共培养协同改变了血管生成和细胞因子反应。结合了连接标记的 iBMEC 的组织工程微血管能够研究在稳态和响应物理和化学干扰期间紧密连接的实时动态。
