Human primed and naïve PSCs are both competent in differentiating into bona fide trophoblast stem cells

Abstract

SummaryCells of the trophoblast lineage constitute the major part of placental tissues in higher mammals. Recent derivation of human trophoblast stem cells (TSC) from placental cytotrophoblasts (CT) and from human naïve PSCs opens new opportunities for studying development and function of human placenta. Several recent reports have suggested that naïve human PSCs retain an exclusive potential to give rise to bona fide TSCs. Here we report that inhibition of TGFβ pathway and avoiding WNT stimulation, leads to direct and robust conversion of primed human pluripotent stem cells into TSCs. Systematic side by side comparative analysis showed that the latter are equivalent to previously derived TSC lines. Primed PSC derived TSC lines exhibit self-renewal, are able to differentiate into the main trophoblast lineages, and present RNA and epigenetic profiles that are indistinguishable from the TSC lines derived from placenta or naïve PSCs. Our findings underscore a residual plasticity in primed human PSCs that allows converting directly into pre-implantation extra-embryonic cell lineages.HighlightsPrimed human PSCs readily convert into TSCs upon inhibition of TGF pathwayCHIR inhibits conversion to TSC in primed but not in naive hPSCsPrimed human PSC derived TSCs line are indistinguishable from placental and naïve derived TSCsYAP is sufficient for TSC induction from hPSCs and necessary for TSC maintenance.

Accessing the human trophoblast stem cell state from pluripotent and somatic cells

“…Several recent studies indicate that it is possible to generate hTSC-like cells directly from primed hPSCs under modified culture conditions. A short pulse of BMP4, BMP4 and IWP2, or A83-01 can redirect primed hESCs away from a neural fate and towards a trophoblast identity [99][100][101][102][103][104]. However, there may be subtle but significant differences between hTSC-like cells derived from naïve and primed cells, such as the expression level of placentally imprinted C19 miRNAs [105], which is one of the original trophoblast criteria proposed by Lee et al [38].…”

“…The generation of hTSCs from primed hPSCs was reported via micromesh culture [99] or by pre-treatment with BMP4, a combination of BMP4 and the WNT inhibitor IWP2, or the TGFβ inhibitor A83-01 before applying hTSC media (Fig. 3) [100][101][102][103][104]. The resulting cells share several global features with primary hTSCs, including gene expression, differentiation potential towards EVT and STB lineages, and increased chromatin accessibility at trophoblast-specific genes.…”

“…3 Derivation of hTSC-like cells from primed hPSCs. Primed hPSCs can be transitioned through an intermediate cell type with a pulse of BMP4 ± IWP2 or A83-01, followed by SAVECY medium to acquire an hTSC-like state [31,100,[102][103][104]112] a unique feature of primary trophoblast [38]. Building on their scRNA-seq analysis, Liu and colleagues [36] identified GATA2 and TFAP2C as important regulators during somatic cell reprogramming into naïve iPSCs.…”