Defining molecular cornerstones during fibroblast to iPS cell reprogramming in mouse

Cell Stem Cell. 2008 Mar 6;2(3):230-40. doi: 10.1016/j.stem.2008.02.001. Epub 2008 Feb 14.

Abstract

Ectopic expression of the transcription factors Oct4, Sox2, c-Myc, and Klf4 in fibroblasts generates induced pluripotent stem (iPS) cells. Little is known about the nature and sequence of molecular events accompanying nuclear reprogramming. Using doxycycline-inducible vectors, we have shown that exogenous factors are required for about 10 days, after which cells enter a self-sustaining pluripotent state. We have identified markers that define cell populations prior to and during this transition period. While downregulation of Thy1 and subsequent upregulation of SSEA-1 occur at early time points, reactivation of endogenous Oct4, Sox2, telomerase, and the silent X chromosome mark late events in the reprogramming process. Cell sorting with these markers allows for a significant enrichment of cells with the potential to become iPS cells. Our results suggest that factor-induced reprogramming is a gradual process with defined intermediate cell populations that contain the majority of cells poised to become iPS cells.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Dedifferentiation* / genetics
  • Cells, Cultured
  • Female
  • Fibroblasts / cytology
  • Fibroblasts / metabolism*
  • Genetic Vectors
  • Lewis X Antigen
  • Mice
  • Mice, Transgenic
  • Pluripotent Stem Cells / cytology
  • Pluripotent Stem Cells / metabolism*
  • Telomerase / biosynthesis
  • Telomerase / genetics
  • Thy-1 Antigens / biosynthesis
  • Thy-1 Antigens / genetics
  • Time Factors
  • Transcription Factors / genetics
  • Transcription Factors / metabolism*
  • X Chromosome / genetics
  • X Chromosome / metabolism

Substances

  • Lewis X Antigen
  • Thy-1 Antigens
  • Transcription Factors
  • Telomerase