An elaborate regulation of Mammalian target of rapamycin activity is required for somatic cell reprogramming induced by defined transcription factors

Stem Cells Dev. 2012 Sep 20;21(14):2630-41. doi: 10.1089/scd.2012.0015. Epub 2012 May 17.

Abstract

The mammalian target of the rapamycin (mTOR) signaling pathway functions in many cellular processes, including cell growth, proliferation, differentiation, and survival. Recent advances have demonstrated that differentiated somatic cells can be directly reprogrammed into the pluripotent state by overexpression of several pluripotency transcription factors. However, whether the mTOR signaling pathway is involved in this somatic cell-reprogramming process remains unknown. Here, we provide evidence that an elaborate regulation of the mTOR activity is required for the successful reprogramming of somatic cells to pluripotency. The reprogramming of somatic cells collected from the Tsc2(-/-) embryo, in which the mTOR activity is hyperactivated, is entirely inhibited. By taking advantage of the secondary inducible pluripotent stem (iPS) system, we demonstrate that either elevating the mTOR activity by Tsc2 shRNA knockdown or using high concentrations of rapamycin to completely block the mTOR activity in cells derived from iPS mice greatly impairs somatic cell reprogramming. Secondary iPS induction efficiency can only be elevated by elaborately regulating the mTOR activity. Taken together, our data demonstrate that the precise regulation of the mTOR activity plays a critical role in the successful reprogramming of somatic cells to form iPS cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Differentiation*
  • Cell Proliferation
  • Embryo, Mammalian / cytology
  • Embryo, Mammalian / enzymology
  • Enzyme Activation
  • Female
  • Fibroblasts / cytology
  • Fibroblasts / drug effects
  • Fibroblasts / enzymology
  • Gene Expression Regulation, Enzymologic*
  • Induced Pluripotent Stem Cells / enzymology
  • Male
  • Mice
  • Mice, 129 Strain
  • Octamer Transcription Factor-3 / genetics
  • Octamer Transcription Factor-3 / metabolism*
  • RNA, Small Interfering / genetics
  • RNA, Small Interfering / metabolism
  • SOXB1 Transcription Factors / genetics
  • SOXB1 Transcription Factors / metabolism
  • Signal Transduction
  • Sirolimus / pharmacology
  • Specific Pathogen-Free Organisms
  • TOR Serine-Threonine Kinases / genetics
  • TOR Serine-Threonine Kinases / metabolism*
  • Tuberous Sclerosis Complex 2 Protein
  • Tumor Suppressor Proteins / genetics
  • Tumor Suppressor Proteins / metabolism

Substances

  • Octamer Transcription Factor-3
  • Pou5f1 protein, mouse
  • RNA, Small Interfering
  • SOXB1 Transcription Factors
  • Sox2 protein, mouse
  • Tsc2 protein, mouse
  • Tuberous Sclerosis Complex 2 Protein
  • Tumor Suppressor Proteins
  • TOR Serine-Threonine Kinases
  • mTOR protein, mouse
  • Sirolimus