Optimization of culture conditions for maintaining porcine induced pluripotent stem cells

DNA Cell Biol. 2014 Jan;33(1):1-11. doi: 10.1089/dna.2013.2095. Epub 2013 Nov 20.

Abstract

Ground state porcine induced pluripotent stem cells (piPSCs), which retain the potential to generate chimeric animal and germline transmission, are difficult to produce. This study investigated morphological and biological progression at the early stage of porcine somatic cell reprogramming, and explored suitable conditions to increase the induction efficiency of piPSCs. A cocktail of defined transcription factors was used to generate piPSCs. The amphotropic retrovirus, which carried human OCT4 (O), SOX2 (S), KLF4 (K), C-MYC (M), TERT (T), and GFP, were used to infect porcine embryonic fibroblasts (PEFs). The number of clones derived from OSKM (4F) and OSKMT (4F+T) was significantly higher than that from SKM (3F) and SKMT (3F+T), suggesting that OCT4 played a critical role in regulating porcine cell reprogramming. The number of alkaline phosphatase-positive clones from a medium with leukemia inhibitory factor (LIF) and basic fibroblast growth factor (bFGF) (M1 medium) was significantly higher than that with insulin and 2i PD0325901/CHIR99021 (M2 medium), indicating that insulin and 2i could not effectively maintain piPSC propagation. In the M1 medium, piPSC lines could not maintain the typical self-renewal morphology on gelatin-coated and Matrigel-coated plates. Without the mouse embryonic fibroblast (MEF) feeder, piPSCs started to simultaneously differentiate. Based on the potential for self-renewal and activation of pluripotent markers, we found that the culture condition of 4F+T plus LIF and bFGF plus MEF feeder promoted PEF reprogramming more efficiently than the other conditions tested here. Two piPSC lines (IB-1 and IB-2) were derived and maintained for up to 20 passages in vitro.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Culture Techniques / methods*
  • Cellular Reprogramming
  • Fetus / cytology
  • Fibroblast Growth Factor 2 / genetics
  • Fibroblast Growth Factor 2 / metabolism
  • Fibroblast Growth Factor 2 / pharmacology*
  • Fibroblasts / cytology*
  • Fibroblasts / drug effects
  • Fluorescent Antibody Technique
  • Genetic Vectors / genetics
  • Humans
  • Induced Pluripotent Stem Cells / cytology*
  • Kruppel-Like Factor 4
  • Kruppel-Like Transcription Factors / genetics
  • Kruppel-Like Transcription Factors / metabolism
  • Kruppel-Like Transcription Factors / pharmacology*
  • Leukemia Inhibitory Factor / genetics
  • Leukemia Inhibitory Factor / metabolism
  • Leukemia Inhibitory Factor / pharmacology*
  • Mice
  • Polymerase Chain Reaction
  • Retroviridae / genetics
  • Swine

Substances

  • KLF4 protein, human
  • Klf4 protein, mouse
  • Kruppel-Like Factor 4
  • Kruppel-Like Transcription Factors
  • Leukemia Inhibitory Factor
  • Fibroblast Growth Factor 2