Mowat-Wilson syndrome factor ZEB2 controls early formation of human neural crest through BMP signaling modulation.

Mowat-Wilson syndrome is caused by mutations in ZEB2, with patients exhibiting characteristics indicative of neural crest (NC) defects. We examined the contribution of ZEB2 to human NC formation using a model based on human embryonic stem cells. We found ZEB2 to be one of the earliest factors expressed in prospective human NC, and knockdown revealed a role for ZEB2 in establishing the NC state while repressing pre-placodal and non-neural ectoderm genes. Examination of ZEB2 N-terminal mutant NC cells demonstrates its requirement for the repression of enhancers in the NC gene network and proper NC cell terminal differentiation into osteoblasts and peripheral neurons and neuroglia. This ZEB2 mutation causes early misexpression of BMP signaling ligands, which can be rescued by the attenuation of BMP. Our findings suggest that ZEB2 regulates early human NC specification by modulating proper BMP signaling and further elaborate the molecular defects underlying Mowat-Wilson syndrome.

WNT/ß-catenin modulates the axial identity of embryonic stem cell-derived human neural crest.

WNT/ß-catenin signaling is crucial for neural crest (NC) formation, yet the effects of the magnitude of the WNT signal remain ill-defined. Using a robust model of human NC formation based on human pluripotent stem cells (hPSCs), we expose that the WNT signal modulates the axial identity of NCs in a dose-dependent manner, with low WNT leading to anterior OTX+ HOX- NC and high WNT leading to posterior OTX- HOX+ NC. Differentiation tests of posterior NC confirm expected derivatives, including posterior-specific adrenal derivatives, and display partial capacity to generate anterior ectomesenchymal derivatives. Furthermore, unlike anterior NC, posterior NC exhibits a transient TBXT+/SOX2+ neuromesodermal precursor-like intermediate. Finally, we analyze the contributions of other signaling pathways in posterior NC formation, which suggest a crucial role for FGF in survival/proliferation, and a requirement of BMP for NC maturation. As expected retinoic acid (RA) and FGF are able to modulate HOX expression in the posterior NC. Surprisingly, early RA supplementation prohibits NC formation. This work reveals for the first time that the amplitude of WNT signaling can modulate the axial identity of NC cells in humans.