Primary cilium-autophagy-Nrf2 (PAN) axis links the cell cycle to neuroectoderm fate in human embryonic stem cells

Under defined differentiation conditions human embryonic stem cells (hESCs) can be directed toward a mesendodermal (ME) or neuroectoderm (NE) fate, the first decision during hESC differentiation. Coupled with G1 lengthening a divergent ciliation pattern emerged within the first 24 hours of induced lineage specification and these changes heralded a neuroectoderm decision before any neural precursor markers were expressed. By day 2, increased ciliation in NE precursors induced autophagy that resulted in the inactivation of Nrf2. Nrf2 binds directly to upstream regions of the OCT4 and NANOG genes to promote their expression and represses NE derivation. Nrf2 suppression was sufficient to rescue poorly neurogenic iPSC lines. Only after these events have been initiated do neural precursor markers get expressed at day 4. Thus we have identified a primary cilium-autophagy-Nrf2 (PAN) axis coupled to cell cycle progression that directs hESCs toward NE. Overall design: Transcriptome analysis of hESC-derived neuroectoderm and mesendoderm cells