title: Excessive Cellular Proliferation Negatively Impacts Reprogramming Efficiency of Human Fibroblasts.
abstract: The impact of somatic cell proliferation rate on induction of pluripotent stem cells remains controversial. Herein, we report that rapid proliferation of human somatic fibroblasts is detrimental to reprogramming efficiency when reprogrammed using a lentiviral vector expressing OCT4, SOX2, KLF4, and cMYC in insulin-rich defined medium. Human fibroblasts grown in this medium showed higher proliferation, enhanced expression of insulin signaling and cell cycle genes, and a switch from glycolytic to oxidative phosphorylation metabolism, but they displayed poor reprogramming efficiency compared with cells grown in normal medium. Thus, in contrast to previous studies, our work reveals an inverse correlation between the proliferation rate of somatic cells and reprogramming efficiency, and also suggests that upregulation of proteins in the growth factor signaling pathway limits the ability to induce pluripotency in human somatic fibroblasts.
  
  
  CONCLUSIONS
  The efficiency with which human cells can be reprogrammed is of interest to stem cell biology. In this study, human fibroblasts cultured in media containing different concentrations of growth factors such as insulin and insulin-like growth factor-1 exhibited variable abilities to proliferate, with consequences on pluripotency. This occurred in part because of changes in the expression of proteins involved in the growth factor signaling pathway, glycolysis, and oxidative phosphorylation. These findings have implications for efficient reprogramming of human cells.
authors.affiliation: Sections of Islet Cell and Regenerative Biology and Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA;
authors.forename: Manoj K
authors.initials: MK
authors.lastname: Gupta
authors.affiliation: Sections of Islet Cell and Regenerative Biology and Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA;
authors.forename: Adrian Kee Keong
authors.initials: AK
authors.lastname: Teo
authors.affiliation: Sections of Islet Cell and Regenerative Biology and Howard Hughes Medical Institute, Department of Stem Cell and Regenerative Biology, Harvard Stem Cell Institute, Harvard University, Cambridge, Massachusetts, USA.
authors.forename: Tata Nageswara
authors.initials: TN
authors.lastname: Rao
authors.affiliation: Sections of Islet Cell and Regenerative Biology and Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA;
authors.forename: Shweta
authors.initials: S
authors.lastname: Bhatt
authors.affiliation: Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA; Integrative Physiology and Metabolism, Joslin Diabetes Center, and.
authors.forename: Andre
authors.initials: A
authors.lastname: Kleinridders
authors.affiliation: Sections of Islet Cell and Regenerative Biology and Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA;
authors.forename: Jun
authors.initials: J
authors.lastname: Shirakawa
authors.affiliation: Sections of Islet Cell and Regenerative Biology and Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA;
authors.forename: Tomozumi
authors.initials: T
authors.lastname: Takatani
authors.affiliation: Sections of Islet Cell and Regenerative Biology and Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA;
authors.forename: Jiang
authors.initials: J
authors.lastname: Hu
authors.affiliation: Sections of Islet Cell and Regenerative Biology and Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA;
authors.forename: Dario F
authors.initials: DF
authors.lastname: De Jesus
authors.affiliation: Sections of Islet Cell and Regenerative Biology and Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA;
authors.forename: Rebecca
authors.initials: R
authors.lastname: Windmueller
authors.affiliation: Sections of Islet Cell and Regenerative Biology and Howard Hughes Medical Institute, Department of Stem Cell and Regenerative Biology, Harvard Stem Cell Institute, Harvard University, Cambridge, Massachusetts, USA.
authors.forename: Amy J
authors.initials: AJ
authors.lastname: Wagers
authors.affiliation: Sections of Islet Cell and Regenerative Biology and Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA; rohit.kulkarni@joslin.harvard.edu.
authors.forename: Rohit N
authors.initials: RN
authors.lastname: Kulkarni
mesh_terms: D002455:Cell Division / Q000187:drug effects; D015687:Cell Hypoxia; D002478:Cells, Cultured; D000067470:Cellular Reprogramming Techniques; D003470:Culture Media / Q000494:pharmacology; D005347:Fibroblasts / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D018816:Genes, cdc; D006019:Glycolysis / Q000187:drug effects; D006801:Humans; D057026:Induced Pluripotent Stem Cells / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D007328:Insulin / Q000494:pharmacology; D036341:Intercellular Signaling Peptides and Proteins / Q000494:pharmacology; D000090062:Kruppel-Like Factor 4; D010085:Oxidative Phosphorylation / Q000187:drug effects; D015398:Signal Transduction / Q000187:drug effects
chemical_list: D003470:Culture Media; D007328:Insulin; D036341:Intercellular Signaling Peptides and Proteins; C000715467:KLF4 protein, human; D000090062:Kruppel-Like Factor 4
keywords: Cell proliferation; Human pluripotency; Insulin signaling; Reprogramming