Variation of Human Neural Stem Cells Generating Organizer States In Vitro before Committing to Cortical Excitatory or Inhibitory Neuronal Fates

Abstract

SUMMARY Better understanding of the progression of neural stem cells (NSCs) in the developing cerebral cortex is important for modeling neurogenesis and defining the pathogenesis of neuropsychiatric disorders. Here, we use RNA sequencing, cell imaging, and lineage tracing of mouse and human in vitro NSCs and monkey brain sections to model the generation of cortical neuronal fates. We show that conserved signaling mechanisms regulate the acute transition from proliferative NSCs to committed glutamatergic excitatory neurons. As human telencephalic NSCs develop from pluripotency in vitro , they transition through organizer states that spatially pattern the cortex before generating glutamatergic precursor fates. NSCs derived from multiple human pluripotent lines vary in these early patterning states, leading differentially to dorsal or ventral telencephalic fates. This work furthers systematic analyses of the earliest patterning events that generate the major neuronal trajectories of the human telencephalon.

ASD modelling in organoids reveals imbalance of excitatory cortical neuron subtypes during early neurogenesis

“…1E , F and S2E , Table S3 ) (Hanashima et al, 2004; Muzio and Mallamaci, 2005). Therefore, the hem organizer‘s role for the development of the mammalian cortical plate fate in vivo (Caronia- Brown et al, 2014) and in human stem cell differentiation in vitro (Micali et al, 2020) was reproduced in organoids. The MCP included both putative ependymal cells (GMNC+, FOXJ1+) and choroid plexus cells (TTR+, cluster 15) ( Figs.…”

“…Similarly, high fraction of IN was associated with expression of TFs of the RG-LGE lineage (e.g., GSX2, SIX3, DLX1/2 ). In contrast, the abundance of EN-PP was driven by a different set of TFs linked to more medial regions of the pallium, including ZIC1 and PROX1, expressed in the cortical hem organizer (Inoue et al, 2008; Micali et al ., 2020). ZIC1 is an activator of WNT signaling (Merzdorf and Sive, 2006), and consistently, expression of several other activators of the WNT signaling pathway ( WLS, WNT7B ) in RG cells were also predictors of EN-PP abundance ( Fig.…”

Molecular programs of regional specification and neural stem cell fate progression in developing macaque telencephalon

“…Organoids were directed towards a dorso-caudal or antero-ventral telencephalic identity by modulating RSPO3- and FGF8-induced patterning signaling, respectively. Treatment was done during their early differentiation (day in vitro, DIV8-21) when neuroepithelial cells form telencephalic organizer states ( 40 ). Then, organoids were cultured with the same basal differentiation medium and analyzed at DIV35.…”

Expression bias in retinoic acid responsive genes defines variations in neural differentiation of human pluripotent stem cells

“…The transcriptomic architecture of self-organization that we define here allows mapping of regional embryonic signatures within hPSCs preceding the full expression of classical organizer cell types. We have previously reported a regional neural fate bias spanning the dorso-ventral telencephalic axis, which was also divergent in hiPSC lines from a single donor (15). We showed that this lineage bias in neural stem cells resulted from the differential emergence of transcriptomic signatures that led to the formation of the dorso-caudal organizer, the cortical hem, or the antero-ventral domain identity.…”

“…The urgency to address this need is illustrated by recent work reporting developmental differences between hPSC lines in generating regionally specified neural precursors and their possible implications in the etiology of neurodevelopmental disorders (14)(15)(16)(17)(18)(19)(20)(21). Here we employ cellular and genomic approaches to define functionally relevant variation in hPSC lines during in vitro morphogenesis as they traverse the earliest events in forebrain and hindbrain development.…”