Naive Pluripotent Stem Cells Derived Directly from Isolated Cells of the Human Inner Cell Mass

Abstract

SummaryConventional generation of stem cells from human blastocysts produces a developmentally advanced, or primed, stage of pluripotency. In vitro resetting to a more naive phenotype has been reported. However, whether the reset culture conditions of selective kinase inhibition can enable capture of naive epiblast cells directly from the embryo has not been determined. Here, we show that in these specific conditions individual inner cell mass cells grow into colonies that may then be expanded over multiple passages while retaining a diploid karyotype and naive properties. The cells express hallmark naive pluripotency factors and additionally display features of mitochondrial respiration, global gene expression, and genome-wide hypomethylation distinct from primed cells. They transition through primed pluripotency into somatic lineage differentiation. Collectively these attributes suggest classification as human naive embryonic stem cells. Human counterparts of canonical mouse embryonic stem cells would argue for conservation in the phased progression of pluripotency in mammals.

Epigenetic foundations of pluripotent stem cells that recapitulate in vivo pluripotency

“…Naive human ES cells were similarly established directly from human blastocysts. 83 Consistent with ICM-like pluripotency, human ES cells in these conditions display global DNA hypomethylation and the gene expression patterns of naive markers and transposons, which are reminiscent of preimplantation human embryos [84][85][86] ( Figure 5). Of particularly note, inactive X chromosome becomes active in naive-like female cells in vitro, suggesting that reactivation of X chromosome occurs during naive conversion 84,87,88 (Figure 5).…”

Stem Cells: A Renaissance in Human Biology Research

“…Several notable advantages associated with naive pluripotency, such as high single cell cloning efficiency, facile genome editing capability and higher developmental potential, can facilitate gene targeting, relieve researchers from tedious clump passaging, and generate more mature cells for transplantation. To date, several studies reported de novo derivation of naive hPSCs from blastocysts (Gafni et al, 2013;Guo et al, 2016;Theunissen et al, 2014;Ware et al, 2014). It is important to note that diverse media formulations have been utilized to derive and cultivate naive hPSCs, and consequently, cultured cells display distinct molecular and cellular characteristics.…”

From stem cells to human development: a distinctly human perspective on early embryology, cellular differentiation and translational research

“…Building on the culture conditions and transcriptional networks that support the 'resetting' of mouse embryonic stem cells (ESCs) from their gastrulating epiblast-like state to a naïve state, Austin Smith has applied this strategy to generate karyotypically stable naïve-like human pluripotent stem cells (PSCs) from both dissociated human ICM cells (Guo et al, 2016) and existing human ESC lines without the use of transgenes. He discussed the challenges that remain towards achieving a 'ground state' in human: some transcription factors found in the mouse are absent, heterogeneity is observed, responsiveness to LIF is diminished and imprints are eroded.…”