Project description:Human cortical organoids (hCOs), derived from human embryonic stem cells (hESCs), provide an excellent platform to study human brain development and diseases in complex 3D tissue. However, current hCOs lack microvasculature, resulting in limited oxygen and nutrient delivery to inner-most parts of hCOs. Previous studies demonstrated that the expression of human ETS variant 2 (hETV2) directly converts human fibroblasts to functional endothelial cells. Here, we engineered hESCs to ectopically express hETV2 to create in vitro vasculature in hCOs, namely vhCOs (vascularized hCOs). hETV2-expressing cells in hCOs contributed to forming a complex vascular network in hCOs. Importantly, the presence of vascularization resulted in enhanced functional maturation of organoids. We found that vhCOs acquired several blood-brain barrier (BBB) characteristics including increased expression of tight junctions, nutrient transporters, and trans-endothelial electrical resistance. Finally, hETV2-induced endothelium supported the formation of perfused blood vessels in vivo. These vhCOs form vasculature that resemble early prenatal brain, and present a robust model to study brain disease in vitro.
Project description:Blood vessels show various COVID-19-related conditions including thrombosis and cytokine propagation. Existing in vitro blood vessel models cannot represent the consequent changes in the vascular structure or determine the initial infection site, making it difficult to evaluate how epithelial and endothelial tissues are damaged. Here, we developed a microphysiological system (MPS) that co-culture the bronchial organoids and the vascular bed to analyze infection site and interactions. In this system, virus-infected organoids caused damage in vascular structure. However, vasculature was not damaged or infected when the virus was directly introduced to vascular bed. The knockout of interferon-related genes and inhibition of the JAK/STAT pathway reduced the vascular damage, indicating the protective effect of interferon response suppression. The results demonstrate selective infection of bronchial epithelial cells and vascular damage by cytokines and also indicate the applicability of MPS to investigate how the infection influences vascular structure and functions.
Project description:Human cortical organoids (hCOs), derived from human embryonic stem cells (hESCs), provide a platform to study human brain development and diseases in complex three-dimensional tissue. However, current hCOs lack microvasculature, resulting in limited oxygen and nutrient delivery to the inner-most parts of hCOs. We engineered hESCs to ectopically express human ETS variant 2 (ETV2). ETV2-expressing cells in hCOs contributed to forming a complex vascular-like network in hCOs. Importantly, the presence of vasculature-like structures resulted in enhanced functional maturation of organoids. We found that vascularized hCOs (vhCOs) acquired several blood-brain barrier characteristics, including an increase in the expression of tight junctions, nutrient transporters and trans-endothelial electrical resistance. Finally, ETV2-induced endothelium supported the formation of perfused blood vessels in vivo. These vhCOs form vasculature-like structures that resemble the vasculature in early prenatal brain, and they present a robust model to study brain disease in vitro.
Project description:Organoid techniques provide unique platforms to model brain development and neurological disorders. While organoids recapitulating corticogenesis were established, a system modeling human medial ganglionic eminence (MGE) development, a critical ventral brain domain producing cortical interneurons and related lineages, remains to be developed. Here, we describe a system to generate MGE or cortex-specific organoids from human pluripotent stem cells. These organoids recapitulate the developments of MGE and cortex domains respectively. Population and single-cell transcriptomic profiling revealed transcriptional dynamics and lineage productions during MGE and cortical organoids development. Chromatin accessibility landscapes were found to be involved in this process. Furthermore, MGE and cortical organoids generated physiologically functional neurons and neuronal networks. Finally, we applied fusion organoids as a model to investigate human interneuron migration. Together, our study provides a new platform for generating domain-specific brain organoids, for modeling human interneuron migration, and offers deeper insight into molecular dynamics during human brain development.
Project description:Organoid techniques provide unique platforms to model brain development and neurological disorders. While organoids recapitulating corticogenesis were established, a system modeling human medial ganglionic eminence (MGE) development, a critical ventral brain domain producing cortical interneurons and related lineages, remains to be developed. Here, we describe a system to generate MGE or cortex-specific organoids from human pluripotent stem cells. These organoids recapitulate the developments of MGE and cortex domains respectively. Population and single-cell transcriptomic profiling revealed transcriptional dynamics and lineage productions during MGE and cortical organoids development. Chromatin accessibility landscapes were found to be involved in this process. Furthermore, MGE and cortical organoids generated physiologically functional neurons and neuronal networks. Finally, we applied fusion organoids as a model to investigate human interneuron migration. Together, our study provides a new platform for generating domain-specific brain organoids, for modeling human interneuron migration, and offers deeper insight into molecular dynamics during human brain development.
Project description:Organoid techniques provide unique platforms to model brain development and neurological disorders. While organoids recapitulating corticogenesis were established, a system modeling human medial ganglionic eminence (MGE) development, a critical ventral brain domain producing cortical interneurons and related lineages, remains to be developed. Here, we describe a system to generate MGE or cortex-specific organoids from human pluripotent stem cells. These organoids recapitulate the developments of MGE and cortex domains respectively. Population and single-cell transcriptomic profiling revealed transcriptional dynamics and lineage productions during MGE and cortical organoids development. Chromatin accessibility landscapes were found to be involved in this process. Furthermore, MGE and cortical organoids generated physiologically functional neurons and neuronal networks. Finally, we applied fusion organoids as a model to investigate human interneuron migration. Together, our study provides a new platform for generating domain-specific brain organoids, for modeling human interneuron migration, and offers deeper insight into molecular dynamics during human brain development.
Project description:Human brain organoids replicate much of the cellular diversity and developmental anatomy of the human brain. However, the physiology of neuronal circuits within organoids remains under-explored. With high-density CMOS microelectrode arrays and shank electrodes, we captured spontaneous extracellular activity from brain organoids derived from human induced pluripotent stem cells. We inferred functional connectivity from spike timing, revealing a large number of weak connections within a skeleton of significantly fewer strong connections. A benzodiazepine increased the uniformity of firing patterns and decreased the relative fraction of weakly connected edges. Our analysis of the local field potential demonstrate that brain organoids contain neuronal assemblies of sufficient size and functional connectivity to co-activate and generate field potentials from their collective transmembrane currents that phase-lock to spiking activity. These results point to the potential of brain organoids for the study of neuropsychiatric diseases, drug action, and the effects of external stimuli upon neuronal networks.
Project description:We describe the different cell types and their differential gene expression patterns present in six-month-old cortical organoids following single cell analysis.