NANOG-OCT4-SOX2 Regulatory Module in Human Embryonic Stem Cells (dataset 4)

The transcription factors Nanog, Oct4 and Sox2 are the master regulators of pluripotency in mouse embryonic stem cells (mESCs), however, their functions in human ESCs (hESCs) have not been rigorously defined. Here we show that the requirements for NANOG, OCT4 and SOX2 in hESCs differ from those in mESCs. Both NANOG and OCT4 are required for self-renewal and repress differentiation. OCT4 controls both extraembryonic and epiblast-derived cell fates in a BMP4-dependent manner. OCT4-depleted hESCs commit to trophectoderm and primitive endoderm in the presence of BMP4, but undergo neuroectoderm differentiation in the absence of BMP4. NANOG represses neuroectoderm and neural crest commitment, but has little or no effect on the other lineages. We find that SOX2 is not required for self-renewal because it is redundant with SOX3, which is induced in SOX2-depleted hESCs. Simultaneous depletion of both SOX2 and SOX3 induces differentiation into the primitive streak. Unexpectedly, we identify significant variability in the usage of pluripotency factors by individual hESC lines, suggesting that the pluripotency network is remodelled to support a continuum of developmental states. Our study revises the general view of how NANOG, OCT4 and SOX2 orchestrate self-renewal in hESCs.