Generation of human induced pluripotent stem (Ips) cells in serum- and feeder-free defined culture and TGF-Β1 regulation of pluripotency

PLoS One. 2014 Jan 29;9(1):e87151. doi: 10.1371/journal.pone.0087151. eCollection 2014.

Abstract

Human Embryonic Stem cells (hESCs) and human induced Pluripotent Stem cells (hiPSCs) are commonly maintained on inactivated mouse embryonic fibroblast as feeder cells in medium supplemented with FBS or proprietary replacements. Use of culture medium containing undefined or unknown components has limited the development of applications for pluripotent cells because of the relative lack of knowledge regarding cell responses to differentiating growth factors. In addition, there is no consensus as to the optimal formulation, or the nature of the cytokine requirements of the cells to promote their self-renewal and inhibit their differentiation. In this study, we successfully generated hiPSCs from human dental pulp cells (DPCs) using Yamanaka's factors (Oct3/4, Sox2, Klf4, and c-Myc) with retroviral vectors in serum- and feeder-free defined culture conditions. These hiPSCs retained the property of self-renewal as evaluated by the expression of self-renewal marker genes and proteins, morphology, cell growth rates, and pluripotency evaluated by differentiation into derivatives of all three primary germ layers in vitro and in vivo. In this study, we found that TGF-β1 increased the expression levels of pluripotency markers in a dose-dependent manner. However, increasing doses of TGF-β1 suppressed the growth rate of hiPSCs cultured under the defined conditions. Furthermore, over short time periods the hiPSCs cultured in hESF9 or hESF9T exhibited similar morphology, but hiPSCs maintained in hESF9 could not survive beyond 30 passages. This result clearly confirmed that hiPSCs cultured in hESF9 medium absolutely required TGF-β1 to maintain pluripotency. This simple serum-free adherent monoculture system will allow us to elucidate the cell responses to growth factors under defined conditions and can eliminate the risk might be brought by undefined pathogens.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Culture Techniques
  • Cell Differentiation
  • Cell Line
  • Cell Proliferation
  • Cell Shape
  • Cell Transformation, Neoplastic
  • Culture Media, Serum-Free
  • Dental Pulp / cytology
  • Embryoid Bodies / physiology
  • Genetic Vectors
  • Humans
  • Induced Pluripotent Stem Cells / physiology*
  • Induced Pluripotent Stem Cells / transplantation
  • Karyotype
  • Kruppel-Like Transcription Factors / biosynthesis
  • Kruppel-Like Transcription Factors / genetics
  • Mice
  • Mice, SCID
  • Octamer Transcription Factor-3 / biosynthesis
  • Octamer Transcription Factor-3 / genetics
  • Proto-Oncogene Proteins c-myc / biosynthesis
  • Proto-Oncogene Proteins c-myc / genetics
  • Retroviridae / genetics
  • SOXB1 Transcription Factors / biosynthesis
  • SOXB1 Transcription Factors / genetics
  • Teratoma / pathology
  • Transcriptome
  • Transduction, Genetic
  • Transforming Growth Factor beta1 / physiology*

Substances

  • Culture Media, Serum-Free
  • GKLF protein
  • Kruppel-Like Transcription Factors
  • MYC protein, human
  • Octamer Transcription Factor-3
  • POU5F1 protein, human
  • Proto-Oncogene Proteins c-myc
  • SOX2 protein, human
  • SOXB1 Transcription Factors
  • TGFB1 protein, human
  • Transforming Growth Factor beta1

Grant support

This work was supported in part by research grants (no. 22659369 and 24890139) from the Japanese Ministry of Education, Culture, Sports, Science and Technology to TO and SY. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.