A mesenchymal-to-epithelial transition initiates and is required for the nuclear reprogramming of mouse fibroblasts

Cell Stem Cell. 2010 Jul 2;7(1):51-63. doi: 10.1016/j.stem.2010.04.014. Epub 2010 Jun 17.

Abstract

Epithelial-to-mesenchymal transition (EMT) is a developmental process important for cell fate determination. Fibroblasts, a product of EMT, can be reset into induced pluripotent stem cells (iPSCs) via exogenous transcription factors but the underlying mechanism is unclear. Here we show that the generation of iPSCs from mouse fibroblasts requires a mesenchymal-to-epithelial transition (MET) orchestrated by suppressing pro-EMT signals from the culture medium and activating an epithelial program inside the cells. At the transcriptional level, Sox2/Oct4 suppress the EMT mediator Snail, c-Myc downregulates TGF-beta1 and TGF-beta receptor 2, and Klf4 induces epithelial genes including E-cadherin. Blocking MET impairs the reprogramming of fibroblasts whereas preventing EMT in epithelial cells cultured with serum can produce iPSCs without Klf4 and c-Myc. Our work not only establishes MET as a key cellular mechanism toward induced pluripotency, but also demonstrates iPSC generation as a cooperative process between the defined factors and the extracellular milieu. PAPERCLIP:

MeSH terms

  • Animals
  • Cadherins / genetics
  • Cadherins / metabolism
  • Cells, Cultured
  • Cellular Reprogramming / genetics
  • Cellular Reprogramming / physiology*
  • Chromatin Immunoprecipitation
  • Enzyme-Linked Immunosorbent Assay
  • Epithelial Cells / metabolism
  • Epithelial Cells / pathology*
  • Fibroblasts / cytology
  • Induced Pluripotent Stem Cells / cytology
  • Induced Pluripotent Stem Cells / metabolism
  • Kruppel-Like Transcription Factors / genetics
  • Kruppel-Like Transcription Factors / metabolism
  • Mesoderm / metabolism
  • Mesoderm / pathology*
  • Mice
  • Models, Biological
  • Octamer Transcription Factor-3 / genetics
  • Octamer Transcription Factor-3 / metabolism
  • Proto-Oncogene Proteins c-myc / genetics
  • Proto-Oncogene Proteins c-myc / metabolism
  • Reverse Transcriptase Polymerase Chain Reaction
  • SOXB1 Transcription Factors / genetics
  • SOXB1 Transcription Factors / metabolism

Substances

  • Cadherins
  • GKLF protein
  • Kruppel-Like Transcription Factors
  • Myc protein, mouse
  • Octamer Transcription Factor-3
  • Pou5f1 protein, mouse
  • Proto-Oncogene Proteins c-myc
  • SOXB1 Transcription Factors
  • Sox2 protein, mouse

Associated data

  • GEO/GSE15267
  • GEO/GSE21062
  • GEO/GSE21064
  • GEO/GSE21067