title: Synergic reprogramming of mammalian cells by combined exposure to mitotic Xenopus egg extracts and transcription factors.
abstract: Transfer of somatic cell nuclei to enucleated eggs and ectopic expression of specific transcription factors are two different reprogramming strategies used to generate pluripotent cells from differentiated cells. However, these methods are poorly efficient, and other unknown factors might be required to increase their success rate. Here we show that Xenopus egg extracts at the metaphase stage (M phase) have a strong reprogramming activity on mouse embryonic fibroblasts (MEFs). First, they reset replication properties of MEF nuclei toward a replication profile characteristic of early development, and they erase several epigenetic marks, such as trimethylation of H3K9, H3K4, and H4K20. Second, when MEFs are reversibly permeabilized in the presence of M-phase Xenopus egg extracts, they show a transient increase in cell proliferation, form colonies, and start to express specific pluripotency markers. Finally, transient exposure of MEF nuclei to M-phase Xenopus egg extracts increases the success of nuclear transfer to enucleated mouse oocytes and strongly synergizes with the production of pluripotent stem cells by ectopic expression of transcription factors. The mitotic stage of the egg extract is crucial, because none of these effects is detected when using interphasic Xenopus egg extracts. Our data demonstrate that mitosis is essential to make mammalian somatic nuclei prone to reprogramming and that, surprisingly, the heterologous Xenopus system has features that are conserved enough to remodel mammalian nuclei.
authors: Centre National de la Recherche Scientifique (CNRS), Institute of Human Genetics, 34396 Montpellier, France.
authors: Olivier
authors: O
authors: Ganier
authors: Stéphane
authors: S
authors: Bocquet
authors: Isabelle
authors: I
authors: Peiffer
authors: Vincent
authors: V
authors: Brochard
authors: Philippe
authors: P
authors: Arnaud
authors: Aurore
authors: A
authors: Puy
authors: Alice
authors: A
authors: Jouneau
authors: Robert
authors: R
authors: Feil
authors: Jean-Paul
authors: JP
authors: Renard
authors: Marcel
authors: M
authors: Méchali
mesh_terms: D000818:Animals; D001483:Base Sequence; D054337:Cell Dedifferentiation / Q000235:genetics / Q000502:physiology*; D002478:Cells, Cultured; D042002:Chromatin Assembly and Disassembly / Q000235:genetics; D017931:DNA Primers / Q000235:genetics; D005260:Female; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism; D066298:In Vitro Techniques; D057026:Induced Pluripotent Stem Cells / Q000166:cytology / Q000378:metabolism; D051379:Mice; D008938:Mitosis; D053652:Nuclear Transfer Techniques; D009865:Oocytes / Q000166:cytology / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism*; D014981:Xenopus
chemical_list: D017931:DNA Primers; D014157:Transcription Factors