Replacement of Oct4 by Tet1 during iPSC induction reveals an important role of DNA methylation and hydroxymethylation in reprogramming

Cell Stem Cell. 2013 Apr 4;12(4):453-69. doi: 10.1016/j.stem.2013.02.005. Epub 2013 Mar 14.


DNA methylation and demethylation have been proposed to play an important role in somatic cell reprogramming. Here, we demonstrate that the DNA hydroxylase Tet1 facilitates pluripotent stem cell induction by promoting Oct4 demethylation and reactivation. Moreover, Tet1 (T) can replace Oct4 and initiate somatic cell reprogramming in conjunction with Sox2 (S), Klf4 (K), and c-Myc (M). We established an efficient TSKM secondary reprogramming system and used it to characterize the dynamic profiles of 5-methylcytosine (5mC), 5-hydroxymethylcytosine (5hmC), and gene expression during reprogramming. Our analysis revealed that both 5mC and 5hmC modifications increased at an intermediate stage of the process, correlating with a transition in the transcriptional profile. We also found that 5hmC enrichment is involved in the demethylation and reactivation of genes and regulatory regions that are important for pluripotency. Our data indicate that changes in DNA methylation and hydroxymethylation play important roles in genome-wide epigenetic remodeling during reprogramming.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 5-Methylcytosine / metabolism
  • Animals
  • Cellular Reprogramming* / genetics
  • Cytosine / analogs & derivatives*
  • Cytosine / metabolism
  • DNA Methylation* / genetics
  • DNA-Binding Proteins / metabolism*
  • Embryonic Stem Cells / cytology
  • Embryonic Stem Cells / metabolism
  • Enhancer Elements, Genetic / genetics
  • Gene Expression Regulation, Developmental
  • Induced Pluripotent Stem Cells / cytology*
  • Induced Pluripotent Stem Cells / metabolism*
  • Kruppel-Like Factor 4
  • Kruppel-Like Transcription Factors / metabolism
  • Mice
  • Models, Biological
  • Octamer Transcription Factor-3 / metabolism*
  • Proto-Oncogene Proteins / metabolism*
  • Proto-Oncogene Proteins c-myc / metabolism
  • SOXB1 Transcription Factors / metabolism
  • Transcription, Genetic
  • Transcriptome / genetics


  • DNA-Binding Proteins
  • Klf4 protein, mouse
  • Kruppel-Like Factor 4
  • Kruppel-Like Transcription Factors
  • Octamer Transcription Factor-3
  • Pou5f1 protein, mouse
  • Proto-Oncogene Proteins
  • Proto-Oncogene Proteins c-myc
  • SOXB1 Transcription Factors
  • TET1 protein, mouse
  • 5-hydroxymethylcytosine
  • 5-Methylcytosine
  • Cytosine

Associated data

  • GEO/GSE39639