VGLL1 regulates extraembryonic lineage specification in human [RNA-seq II]

Placenta abnormality is one of the key reasons for early pregnancy loss but the regulatory mechanisms underlying placenta formation are largely unknown. Here, we applied a human naïve pluripotent stem cell (PSC) derived TE model to explore the driven regulatory machinery. We demonstrate that VGLL1 (vestigiallikefamilymember1) is crucial for TE self-renewal and TE-specific gene expression, thus suppressing VGLL1 leads to severely impaired cell proliferation and skewed TE induction. VGLL1 exerts its function through interacting with TEAD4 (TEA domain transcription factor 4) and colocalize at target gene promoters and enhancers. Further investigation uncovers the enrichment of H3K27ac active histone marks at genomic regions occupied by VGLL1-TEAD4 complex, indicates a close association between them. Overall, our data reveals the critical function model of VGLL1-TEAD4 in human TE derivation, highlighting a potential interspecies difference between human and mouse TE induction. Overall design: Human naïve PSCs were dissociated into single cells with a 1:1 mixture of 0.5 mM EDTA and TrypLE Express and plated at a density of 100,000 cell/well of 6-well plate on Geltrex in TE induction medium (1:1 mix of Neurobasal medium (Gibco) and DMEM/F12 (HyClone) supplemented with N2 (Gibco) and B27 (Gibco), penicillin-streptomycin (HyClone), Glutamax (Gibco), ß-mercaptoethanol (Sigma), 1 µM PD0325901 (Axon) and 1 µM A83-01 (Selleck)) for five days. TELCs at day 5 were used for downstream analysis throughout this study. For generating expandable TSCs, TELCs at day 5 were dissociated into single cells with TrypLE and plated on Geltrex-coated six-well plates at a 1:4-1:8 split ratio in TSC medium (DMEM/F12 supplemented with N2 and B27, penicillin-streptomycin, Glutamax, ß-mercaptoethanol, 1.5 µg/ml L-ascorbic acid, 50 ng/ml EGF (PeproTech), 0.5 µM A83-01 (Selleck), 1 µM SB431542 (Selleck), 2 µM CHIR99021 (Axon), 0.8 mM VPA (Vetec) and 5 µM Y-27632 (Axon)) supplemented with 10 µM Y-27632.