The human blood-brain barrier (hBBB) is a highly specialized structure that regulates passage across blood and central nervous system (CNS) compartments. Despite its critical physiological role, there are no reliable in vitro models that can mimic hBBB development and function. Here, we constructed hBBB assembloids from brain and blood vessel organoids derived from human pluripotent stem cells. We validated the acquisition of blood-brain barrier (BBB)-specific molecular, cellular, transcriptomic, and functional characteristics and uncovered an extensive neuro-vascular crosstalk with a spatial pattern within hBBB assembloids. When we used patient-derived hBBB assembloids to model cerebral cavernous malformations (CCMs), we found that these assembloids recapitulated the cavernoma anatomy and BBB breakdown observed in patients. Upon comparison of phenotypes and transcriptome between patient-derived hBBB assembloids and primary human cavernoma tissues, we uncovered CCM-related molecular and cellular alterations. Taken together, we report hBBB assembloids that mimic the core properties of the hBBB and identify a potentially underlying cause of CCMs.

人类血脑屏障 (hBBB) 是一种高度专业化的结构，可调节血液和中枢神经系统 (CNS) 区室的通道。尽管 hBBB 具有重要的生理作用，但目前还没有可靠的体外模型可以模拟 hBBB 的发育和功能。在这里，我们利用源自人类多能干细胞的大脑和血管类器官构建了 hBBB 组合体。我们验证了血脑屏障 (BBB) 特异性分子、细胞、转录组和功能特征的获取，并发现了 hBBB 组合体内广泛的神经血管串扰与空间模式。当我们使用患者来源的 hBBB 组合体来模拟脑海绵状血管瘤 (CCM) 时，我们发现这些组合体重现了在患者中观察到的海绵状血管瘤解剖结构和 BBB 破裂。通过比较患者来源的 hBBB 组合体和原发性人类海绵状血管瘤组织之间的表型和转录组，我们发现了与 CCM 相关的分子和细胞改变。综上所述，我们报告了模拟 hBBB 核心特性的 hBBB 组合体，并确定了 CCM 的潜在潜在原因。