Brief Report: Analysis of Endogenous Oct4 Activation during Induced Pluripotent Stem Cell Reprogramming Using an Inducible Oct4 Lineage Label§

Authors

  • Lucas V. Greder,

    1. Stem Cell Institute, University of Minnesota, Minneapolis, Minnesota, USA
    Search for more papers by this author
  • Sandeep Gupta,

    1. Stem Cell Institute, University of Minnesota, Minneapolis, Minnesota, USA
    2. Division of Renal Diseases and Hypertension, Department of Medicine, University of Minnesota, Minneapolis, Minnesota, USA
    Search for more papers by this author
  • Shunan Li,

    1. Stem Cell Institute, University of Minnesota, Minneapolis, Minnesota, USA
    2. Division of Renal Diseases and Hypertension, Department of Medicine, University of Minnesota, Minneapolis, Minnesota, USA
    Search for more papers by this author
  • Md. Joynal Abedin,

    1. Stem Cell Institute, University of Minnesota, Minneapolis, Minnesota, USA
    2. Division of Renal Diseases and Hypertension, Department of Medicine, University of Minnesota, Minneapolis, Minnesota, USA
    Search for more papers by this author
  • Abdulrahim Sajini,

    1. Stem Cell Institute, University of Minnesota, Minneapolis, Minnesota, USA
    Search for more papers by this author
  • Yoav Segal,

    Corresponding author
    1. Division of Renal Diseases and Hypertension, Department of Medicine, University of Minnesota, Minneapolis, Minnesota, USA
    2. Minneapolis VA Health Care System, Minneapolis, Minnesota, USA
    • Division of Renal Diseases and Hypertension, Department of Medicine, University of Minnesota, 717 Delaware Street SE, Suite 353, Minneapolis, Minnesota 55414, USA
    Search for more papers by this author
    • Telephone: 612-467-3271; Fax 612-727-5640

  • Jonathan M.W. Slack,

    1. Stem Cell Institute, University of Minnesota, Minneapolis, Minnesota, USA
    Search for more papers by this author
  • James R. Dutton

    Corresponding author
    1. Stem Cell Institute, University of Minnesota, Minneapolis, Minnesota, USA
    • Stem Cell Institute, University of Minnesota, Room 2-226 MTRF, 2001 6th Street SE, Minneapolis, Minnesota 55455, USA
    Search for more papers by this author
    • Telephone: 612-626-2762; Fax: 612-624-2436


  • Author contributions: L.V.G.: conception and design, collection and/or assembly of data, data analysis and interpretation, manuscript writing, and final approval of manuscript; S.G.: conception and design, financial support, administrative support, data analysis and interpretation, and final approval of manuscript; S.L., Md.J.A., and A.S.: collection and/or assembly of data, data analysis and interpretation, and final approval of manuscript.; Y.S. and J.R.D.: conception and design, financial support, administrative support, collection and/or assembly of data, data analysis and interpretation, manuscript writing, and final approval of manuscript; J.M.W.S.: conception and design, financial support, administrative support, data analysis and interpretation, manuscript writing, and final approval of manuscript.

  • Disclosure of potential conflicts of interest is found at the end of this article.

  • §

    First published online in STEM CELLSEXPRESS September 4, 2012.

Abstract

The activation of endogenous Oct4 transcription is a key step in the reprogramming of somatic cells into induced pluripotent stem (iPS) cells but until now it has been difficult to analyze this critical event in the reprogramming process. We have generated a transgenic mouse that expresses the tamoxifen-inducible Cre recombinase MerCreMer under the control of the endogenous Oct4 locus, enabling lineage tracing of Oct4 expression in cells in vivo or in vitro, during either reprogramming or differentiation. Using this novel resource, we have determined the timing and outcome of endogenous Oct4 induction during fibroblast reprogramming. We show that both the initiation of this key reprogramming step and the ability of cells activating endogenous Oct4 expression to complete reprogramming are not influenced by the presence of exogenous c-Myc, although the overall efficiency of the process is increased by c-Myc. Oct4 lineage tracing reveals that new reprogramming events continue to initiate over a period of 3 weeks. Furthermore, the analysis of mixed colonies, where only a subset of daughter cells induce endogenous Oct4 expression, indicates the role of unknown, stochastic events in the progression of reprogramming from the initial events to a pluripotent state. Our transgenic mouse model and cells derived from it provide powerful and precise new tools for the study of iPS cell reprogramming mechanisms and have wider implications for the investigation of the role of Oct4 during development. STEM CELLS2012;30:2596–2601

Ancillary