GSE184562
Chemical conversion of human conventional Pluripotent Stem Cells to Trophoblast Stem Cells following transient naive genes activation.
In human embryos, naive pluripotent cells of the inner cell mass (ICM) generate epiblast, primitive endoderm and trophectoderm (TE) lineage, whence trophoblast cells derive. In vitro, naive pluripotent stem cells (PSCs) retain this potential and efficiently generate trophoblast stem cells (TSCs), while conventional PSCs form TSCs at low efficiency. Transient histone deacetylase and MEK inhibitions with LIF stimulation is used to chemically reset conventional to naive PSCs. Here we report that chemical resetting induces expression of both naive and TSC markers and of placental imprinted genes. A modified chemical resetting protocol allows for the fast and efficient conversion of conventional PSCs into TSCs, entailing shutdown of pluripotency genes and full activation of the trophoblast master regulators, without induction of amnion markers. Chemical resetting generates a plastic intermediate state, characterised by co-expression of naive and TSC markers, after which cells steer towards one of the two fates in response to the signalling environment. The efficiency and rapidity of our system will be useful to study cell fate transitions, and to generate models of placental disorders. Overall design: Study of transcriptional changes appearing after chemical resetting protocols from primed human iPSCs to naïve human iPSCs and trophoblast stem cells. Samples analyzed: 3 replicates of H9 primed-ESCs (primed controls), 3 replicates of HPD00 primed-iPSCs (primed controls), 3 replicates of HPD01 naive-iPSCs (naïve controls), 3 replicates of HPD06 naive-iPSCs (naïve controls),  4 replicates of KiPS primed-iPSCs (primed controls), 4 replicates of KiPS-chemical resetting (post-chemical resetting samples). For the time-point analysis of the chemical conversion: 4 replicates of KiPS primed-iPSCs (primed controls), 3 replicates of H9 naive-TSCs (TSC controls), 3 replicates of HPD06 naive-TSCs (TSC controls), 3 replicates of ccTSC.01 (post-chemical resetting samples), 3 replicates of ccTSC.02 (post-chemical resetting samples), replicates of different timepoints during the chemical conversion (chemical resetting samples).