Figure 1.

SOX10 transcription factor accelerates oligodendrogenesis in hiPSC-derived organoids

(A) Schematic representation of the protocol for generating submillimetric organoids and integrating hiPSC-derived microglia.

(B–E) Gene expression (normalized to GAPDH) of NES, TUBB3, MAP2, GFAP, S100B, SOX10, MBP, OLIG2, and CNP in SOX10-eGFP organoids—exposed and not exposed to doxycycline for inducing SOX10 expression—at 2, 5, and 8 weeks of differentiation, as determined by real-time qPCR (mixed effect analysis, followed by multiple comparison test) (for doxycycline-treated organoids: RNA samples each consisting of ∼150 organoids from 5 hiPSC lines from 2 differentiation experiments; for doxycycline-untreated organoids: RNA samples each consisting of ∼150 organoids from 5 hiPSC lines from 1 differentiation experiment). Data are represented as average Z score ± SD.

(F) Immunostaining of Nestin⁺ and SOX10⁺ cells in doxycycline-treated organoids after 2 weeks of differentiation (magnification, 30X).

(G) Immunostaining of Tuj1⁺ and SOX10⁺ cells in doxycycline-treated organoids after 5 weeks of differentiation (magnification, 30X).

(H) Electron microscopy images of doxycycline-treated organoids after 10 weeks of differentiation showing a synaptic junction containing vesicles (white arrowhead).

(I) Electron microscopy images of doxycycline-treated organoids after 8 weeks of differentiation showing axonal projections (white arrowhead).

(J) Immunostaining of GFAP⁺ (30X) and S100B⁺ cells (30X) in cryosections from 8-week-old doxycycline-treated organoids.

(K) Immunostaining of PDGFRα⁺ and SOX10⁺ cells in cryosections from 5-week-old doxycycline-treated organoids (30X).

(L) Immunostaining of BCAS1⁺ and SOX10⁺ cells in cryosections from 8-week-old doxycycline-treated organoids (30X).

(M and N) Immunostaining of MBP⁺ cells in cryosections from 8-week-old doxycycline-treated organoids (30X).

(O) Electron microscopy images of organoids showing myelination at different time points (additional examples in Figure S2C).

(P) Immunolabeling of TMEM119⁺ cells and MAP2⁺ in cryosections from 9-week-old organoids (30X).

(Q) Immunolabeling of IBA1⁺ cells, MBP⁺, and MAP2⁺ cells in cryosections from 9-week-old organoids (30X). Abbreviations: NPC, neural precursor cells.