Induction of Myelinating Oligodendrocytes in Human Cortical Spheroids

Organoid technologies provide an accessible system in which to examine the generation, self-organization,and 3-dimensional cellular interactions during development of the human cerebral cortex. However, oligodendrocytes, the myelinating glia of the central nervous system and third major neural cell type, are conspicuously absent from current protocols. Here we reproducibly generate human oligodendrocytes and myelin in pluripotent stem cell-derived cortical spheroids. Transcriptional and immunohistochemical analysis of the spheroids demonstrates molecular features consistent with maturing human oligodendrocytes within 14 weeks of culture, including expression of MyRF, PLP1, and MBP proteins. Histological analysis by electron microscopy shows initial wrapping of human neuronal axons with myelin by 20 weeks and maturation to compact myelin by 30 weeks in culture. Treatment of spheroids with previously identified promyelinating drugs enhances the rate and extent of human oligodendrocyte generation and myelination. Furthermore, generation of spheroids from patients with a severe genetic myelin disorder, Pelizaeus-Merzbacher disease, demonstrates the ability to recapitulate human disease phenotypes, which were in turn improved with both pharmacologic and CRISPR-based approaches. Collectively, these 3-dimensional, multi-lineage cortical spheroids provide a versatile platform to observe and perturb the complex cellular interactions   that occur during developmental myelination of the brain and offer new opportunities for disease modeling and therapeutic development in human tissue. Overall design: RNAseq profiles comparing neuro-cortical spheroids and oligo-cortical spheroids

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Madhavan M, Nevin ZS, Shick HE, Garrison E, Clarkson-Paredes C, Karl M, Clayton BLL, Factor DC, Allan KC, Barbar L, Jain T, Douvaras P, Fossati V, Miller RH, Tesar PJ