Wnt Inhibition Facilitates RNA-Mediated Reprogramming of Human Somatic Cells to Naive Pluripotency

Summary In contrast to conventional human pluripotent stem cells (hPSCs) that are related to post-implantation embryo stages, naive hPSCs exhibit features of pre-implantation epiblast. Naive hPSCs are established by resetting conventional hPSCs, or are derived from dissociated embryo inner cell masses. Here we investigate conditions for transgene-free reprogramming of human somatic cells to naive pluripotency. We find that Wnt inhibition promotes RNA-mediated induction of naive pluripotency. We demonstrate application to independent human fibroblast cultures and endothelial progenitor cells. We show that induced naive hPSCs can be clonally expanded with a diploid karyotype and undergo somatic lineage differentiation following formative transition. Induced naive hPSC lines exhibit distinctive surface marker, transcriptome, and methylome properties of naive epiblast identity. This system for efficient, facile, and reliable induction of transgene-free naive hPSCs offers a robust platform, both for delineation of human reprogramming trajectories and for evaluating the attributes of isogenic naive versus conventional hPSCs.
Highlights • Generation of transgene-free human naive iPSCs by RNA-mediated reprogramming • Wnt inhibition facilitates naive iPSC production and expansion • Naive iPSCs retain a diploid karyotype • Naive iPSCs are transcriptomically related to pre-implantation human epiblast
Molecular reprogramming can induce different states of pluripotency. In this paper, Ge Guo and colleagues report that naive stem cells related to the blastocyst stage human embryo can be generated reliably from human somatic cells using RNA delivery of reprogramming factors. Reprogramming is enhanced by inhibition of the Wnt pathway, which also stabilizes the human naive state.