KLF17 promotes human naïve pluripotency but is not required for its establishment

Abstract

Current knowledge of the transcriptional regulation of human pluripotency is incomplete, with lack of inter-species conservation observed. Single-cell transcriptomics analysis of human embryos previously enabled us to identify transcription factors, including the zinc-finger protein KLF17, that are enriched in the human epiblast and naïve hESCs. Here we show that KLF17 is expressed coincident with the known pluripotency-associated factors NANOG and SOX2 across human blastocyst development. We investigate the function of KLF17 using primed and naïve hESCs for gain- and loss-of-function analyses. We find that ectopic expression of KLF17 in primed hESCs is sufficient to induce a naïve-like transcriptome and that KLF17 can drive transgene-mediated resetting to naïve pluripotency. This implies a role for KLF17 in establishing naïve pluripotency. However, CRISPR-Cas9-mediated knockout studies reveal that KLF17 is not required for naïve pluripotency acquisition in vitro. Transcriptome analysis of naïve hESCs identifies subtle effects on metabolism and signalling pathways following KLF17 loss-of-function, and possible redundancy with other KLF paralogues. Overall, we show that KLF17 is sufficient, but not necessary, for naïve pluripotency under the given in vitro conditions.

Histone remodeling reflects conserved mechanisms of bovine and human preimplantation development

“…For example, whereas GATA3 induces TE fate (Ralston et al , 2010; Deglincerti et al , 2016; Gerri et al , 2020a), GATA6 and GATA4 are implicated in primitive endoderm specification and maintenance (Chazaud et al , 2006; Plusa et al , 2008; Roode et al , 2012). Among KLFs, which generally play roles in pluripotency maintenance, KLF2 marks murine epiblast but is absent in humans, whereas KLF17 is widespread in human blastocysts but absent in mouse (Yeo et al , 2014; Blakeley et al , 2015; Lea et al , 2021). Enrichment of KLF motifs in bovine morula, ICM, and TE is reminiscent of the widespread expression of KLF17 in human embryos, but it remains to be determined which member(s) of the KLF family are active in bovine; several candidates are expressed at the blastocyst stage, including KLF6 , which undergoes a 14‐fold increase in expression between the 16‐cell and blastocyst stages (Fig EV5B).…”

Resetting H3K4me3, H3K27ac, H3K9me3 and H3K27me3 during the maternal-to-zygotic transition and blastocyst lineage specification in bovine embryos

“…For example, whereas GATA3 induces TE fate 59,62,63 , GATA6 and GATA4 are implicated in primitive endoderm specification and maintenance [64][65][66] . Among KLFs, which generally play roles in pluripotency maintenance, KLF2 marks murine epiblast but is absent in humans , whereas KLF17 is widespread in human blastocysts but absent in mouse [67][68][69] . The enrichment of KLF motifs in bovine morula, ICM, and TE is reminiscent of the widespread expression KLF17 in human embryos, but it remains to be determined which member(s) of the KLF family are active in bovine; several candidates are expressed at the blastocyst stage, including KLF6, which undergoes a 14-fold increase in expression between the 16-cell and blastocyst stages (Extended Fig.…”

NANOGP1, a tandem duplicate of NANOG, exhibits partial functional conservation in human naïve pluripotent stem cells

“…By engineering cells that expressed gene-specific CRISPR-interference to transcriptionally repress NANOGP1 , we found that naïve hPSCs were unaffected by the robust knockdown of NANOGP1 . Interestingly, the capacity of NANOGP1 to induce naïve pluripotency but be unnecessary for its maintenance parallels another naïve pluripotency factor – KLF17 ( Lea et al, 2021 ). In contrast, the knockdown of NANOG caused naïve hPSCs to exit the naïve state and differentiate towards the trophoblast lineage.…”