Human embryonic stem cells with biological and epigenetic characteristics similar to those of mouse ESCs

Abstract

Human and mouse embryonic stem cells (ESCs) are derived from blastocyst-stage embryos but have very different biological properties, and molecular analyses suggest that the pluripotent state of human ESCs isolated so far corresponds to that of mouse-derived epiblast stem cells (EpiSCs). Here we rewire the identity of conventional human ESCs into a more immature state that extensively shares defining features with pluripotent mouse ESCs. This was achieved by ectopic induction of Oct4, Klf4, and Klf2 factors combined with LIF and inhibitors of glycogen synthase kinase 3β (GSK3β) and mitogen-activated protein kinase (ERK1/2) pathway. Forskolin, a protein kinase A pathway agonist which can induce Klf4 and Klf2 expression, transiently substitutes for the requirement for ectopic transgene expression. In contrast to conventional human ESCs, these epigenetically converted cells have growth properties, an X-chromosome activation state (XaXa), a gene expression profile, and a signaling pathway dependence that are highly similar to those of mouse ESCs. Finally, the same growth conditions allow the derivation of human induced pluripotent stem (iPS) cells with similar properties as mouse iPS cells. The generation of validated “naïve” human ESCs will allow the molecular dissection of a previously undefined pluripotent state in humans and may open up new opportunities for patient-specific, disease-relevant research.

LacdiNAc (GalNAcβ1-4GlcNAc) Contributes to Self-Renewal of Mouse Embryonic Stem Cells by Regulating Leukemia Inhibitory Factor/STAT3 Signaling

“…mEpiSC-like cells were induced to revert to mESCs as described previously [25,42]. In brief, the EpiSC-like cells were seeded on inactivated MEFs as small clumps and cultured with serum-free medium containing 1,000 U/ml LIF, 1 lM PD0325901 (Wako), 3 lM CHIR99021 (Wako), 10 lM forskolin (Stemgent, San Diego, CA, www.stemgent.com), and 2 lM SB431542 (Wako).…”

“…and that these different states reflected differences in signaling required for maintenance of self-renewal [25]. However, the key factors that underlie the differences in signaling between mESCs and hESCs have yet to be clarified.…”

Mechanism and methods to induce pluripotency

“…Overexpressing Klf4 prompted mouse epiblast derived stem cells (EpiSCs) to enter the naïve ES cell state . Similarly, human ES cells and iPS cells with elevated levels of Klf4 and Oct4 or Klf4 and Klf2 exhibiting mouse ESC characteristics were able to grow in a medium containing leukemia inhibitory factor (LIF) and 2i (ERK1/2 and GSK3 inhibitors), and had both X chromosomes activated (Hanna et al, 2010a).…”

Concise Review: Induced Pluripotent Stem Cells Versus Embryonic Stem Cells: Close Enough or Yet Too Far Apart?

“…The possibility of directly converting human pluripotent cells into mouse-like ESC is tempting. So far it has been achieved by constitutive expression of transcription factors, producing either metastable cells without proper epigenetic activation of major pluripotency regulators [22], or cells stable for only several passages [23]. Possibly, the optimal isolation and culture conditions required for human ESC culture have not yet been met.…”