Department of Chemical and Biomedical Engineering, FAMU-FSU College of Engineering, Florida State University, Tallahassee, FL, USA.
Department of Biomedical Sciences, College of Medicine, Florida State University, Tallahassee, Florida, USA.
Sci Rep. 2019 Apr 12;9(1):5977. doi: 10.1038/s41598-019-42439-9.
Human cerebral organoids derived from induced pluripotent stem cells (iPSCs) provide novel tools for recapitulating the cytoarchitecture of human brain and for studying biological mechanisms of neurological disorders. However, the heterotypic interactions of neurovascular units, composed of neurons, pericytes, astrocytes, and brain microvascular endothelial cells, in brain-like tissues are less investigated. The objective of this study is to investigate the impacts of neural spheroids and vascular spheroids interactions on the regional brain-like tissue patterning in cortical spheroids derived from human iPSCs. Hybrid neurovascular spheroids were constructed by fusion of human iPSC-derived cortical neural progenitor cell (iNPC) spheroids, endothelial cell (iEC) spheroids, and the supporting human mesenchymal stem cells (MSCs). Single hybrid spheroids were constructed at different iNPC: iEC: MSC ratios of 4:2:0, 3:2:1 2:2:2, and 1:2:3 in low-attachment 96-well plates. The incorporation of MSCs upregulated the secretion levels of cytokines VEGF-A, PGE2, and TGF-β1 in hybrid spheroid system. In addition, tri-cultured spheroids had high levels of TBR1 (deep cortical layer VI) and Nkx2.1 (ventral cells), and matrix remodeling genes, MMP2 and MMP3, as well as Notch-1, indicating the crucial role of matrix remodeling and cell-cell communications on cortical spheroid and organoid patterning. Moreover, tri-culture system elevated blood-brain barrier gene expression (e.g., GLUT-1), CD31, and tight junction protein ZO1 expression. Treatment with AMD3100, a CXCR4 antagonist, showed the immobilization of MSCs during spheroid fusion, indicating a CXCR4-dependent manner of hMSC migration and homing. This forebrain-like model has potential applications in understanding heterotypic cell-cell interactions and novel drug screening in diseased human brain.
人类诱导多能干细胞（iPSC）衍生的大脑类器官为重现人脑的细胞结构和研究神经发育障碍的生物学机制提供了新的工具。然而，由神经元、周细胞、星形胶质细胞和脑微血管内皮细胞组成的神经血管单元的异质相互作用在类脑组织中研究较少。本研究旨在探讨神经球体和血管球体相互作用对源自人 iPSC 的皮质球体中区域性类脑组织模式形成的影响。通过融合人 iPSC 衍生的皮质神经祖细胞（iNPC）球体、内皮细胞（iEC）球体和支持性人间充质干细胞（MSC）构建杂交神经血管球体。在低附着 96 孔板中，以不同的 iNPC:iEC:MSC 比例（4:2:0、3:2:1、2:2:2 和 1:2:3）构建单杂交球体。MSC 的掺入上调了杂交球体系统中细胞因子 VEGF-A、PGE2 和 TGF-β1 的分泌水平。此外，三培养球体具有高 TBR1（深层皮质 VI 层）和 Nkx2.1（腹侧细胞）以及基质重塑基因 MMP2 和 MMP3 的水平，以及 Notch-1，表明基质重塑和细胞-细胞通讯对皮质球体和类器官模式形成的关键作用。此外，三培养系统提高了血脑屏障基因（如 GLUT-1）、CD31 和紧密连接蛋白 ZO1 的表达。用 CXCR4 拮抗剂 AMD3100 处理显示 MSC 在球体融合过程中的固定，表明 hMSC 迁移和归巢的 CXCR4 依赖性方式。这种前脑样模型在理解异型细胞-细胞相互作用和疾病人类大脑中的新型药物筛选方面具有潜在应用。
