ATAC-seq in NrESC

ATAC-seq in NrESC_1, NrESC_16, ESC, EPSC Embryonic stem cells upon extrinsic induction could self-assemble into blastocyst-like structures. However, the intrinsic regulation of such blastoid forming potential remain to be addressed. We discover that the activity of nuclear receptor subfamily 1, group H, member 2 (Nr1h2) in expanded potential stem cell (EPSC) positively correlates with blastoid efficiency and quality. In addition, Nr1h2 agonist, T0901317, improves natural blastocyst development. Surprisingly, Nr1h2-activated ESC (NrESC) is rewired towards a distinct pluripotency state that is capable of self-organizing into blastoids and contribute to embryonic and extraembryonic lineage. We hypothesize that Nr1h2 activation broadly affects the transcriptome landscape by regulating chromatin accessibility and epigenome to rewire ESC state. Indeed, from ATAC-seq analysis, we observe some genomic regions progressively gained accessibility in NrESC over passages, which lead to a unique chromatin accessibility profile in NrESC compared to conventional ESC and EPSC. Binding motifs of Pou5f1, Sox2 and Tead4, which are known master regulator of blastocyst lineage specification, showed gained accessibility in NrESC. In summary, our study demonstrates a novel Nr1h2-centric regulation of expanded pluripotency in terms of chromatin reorganization.