title: MyoD gene suppression by Oct4 is required for reprogramming in myoblasts to produce induced pluripotent stem cells.
abstract: Expression of the four transcription factors, that is, Oct4, Sox2, cMyc, and Klf4 has been shown to generate induced pluripotent stem cells (iPSCs) from many types of specialized differentiated somatic cells. It remains unclear, however, whether fully committed skeletal muscle progenitor cells (myoblasts) have the potency to undergo reprogramming to develop iPSCs in line with previously reported cases. To test this, we have isolated genetically marked myoblasts derived from satellite cell of adult mouse muscles using the Cre-loxP system (Pax7-CreER:R26R and Myf5-Cre:R26R). On infection with retroviral vectors expressing the four factors, these myoblasts gave rise to myogenic lineage tracer lacZ-positive embryonic stem cell (ESC)-like colonies. These cells expressed ESC-specific genes and were competent to differentiate into all three germ layers and germ cells, indicating the successful generation of myoblast-derived iPSCs. Continuous expression of the MyoD gene, a master transcription factor for skeletal muscle specification, inhibited this reprogramming process in myoblasts. In contrast, reprogramming myoblasts isolated from mice lacking the MyoD gene led to an increase in reprogramming efficiency. Our data also indicated that Oct4 acts as a transcriptional suppressor of MyoD gene expression through its interaction with the upstream enhancer region. Taken together, these results indicate that suppression of MyoD gene expression by Oct4 is required for the initial reprogramming step in the development of iPSCs from myoblasts. This data suggests that the skeletal muscle system provides a well-defined differentiation model to further elaborate on the effects of iPSC reprogramming in somatic cells.
authors.affiliation: Stem Cell Institute, University of Minnesota Medical School, Minneapolis, Minnesota 55455, USA.
authors.forename: Shuichi
authors.initials: S
authors.lastname: Watanabe
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Hirai
authors.forename: Yoko
authors.initials: Y
authors.lastname: Asakura
authors.forename: Christopher
authors.initials: C
authors.lastname: Tastad
authors.forename: Mayank
authors.initials: M
authors.lastname: Verma
authors.forename: Charles
authors.initials: C
authors.lastname: Keller
authors.forename: James R
authors.initials: JR
authors.lastname: Dutton
authors.forename: Atsushi
authors.initials: A
authors.lastname: Asakura
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D065150:Cellular Reprogramming / Q000235:genetics*; D015536:Down-Regulation / Q000235:genetics; D005260:Female; D057026:Induced Pluripotent Stem Cells / Q000378:metabolism / Q000502:physiology*; D000090062:Kruppel-Like Factor 4; D051379:Mice; D008813:Mice, Inbred ICR; D016688:Mice, Inbred NOD; D018345:Mice, Knockout; D016513:Mice, SCID; D017570:MyoD Protein / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D032446:Myoblasts / Q000166:cytology / Q000378:metabolism / Q000502:physiology*; D050814:Octamer Transcription Factor-3 / Q000378:metabolism / Q000502:physiology*; D011247:Pregnancy
chemical_list: C000715468:Klf4 protein, mouse; D000090062:Kruppel-Like Factor 4; D017570:MyoD Protein; C057363:MyoD1 myogenic differentiation protein; D050814:Octamer Transcription Factor-3