title: Two-phase analysis of molecular pathways underlying induced pluripotent stem cell induction.
abstract: Induced pluripotent stem cells (iPSCs) can be reprogrammed from adult somatic cells by transduction with Oct4, Sox2, Klf4, and c-Myc, but the molecular cascades initiated by these factors remain poorly understood. Impeding their elucidation is the stochastic nature of the iPS induction process, which results in heterogeneous cell populations. Here we have synchronized the reprogramming process by a two-phase induction: an initial stable intermediate phase following transduction with Oct4, Klf4, and c-Myc, and a final iPS phase following overexpression of Sox2. This approach has enabled us to examine temporal gene expression profiles, permitting the identification of Sox2 downstream genes critical for induction. Furthermore, we have validated the feasibility of our new approach by using it to confirm that downregulation of transforming growth factor β signaling by Sox2 proves essential to the reprogramming process. Thus, we present a novel means for dissecting the details underlying the induction of iPSCs, an approach with significant utility in this arena and the potential for wide-ranging implications in the study of other reprogramming mechanisms.
authors.affiliation: MOE Key Laboratory of Model Animal for Disease Study, Model Animal Research Center of Nanjing University, Nanjing, Jiangsu, People's Republic of China.
authors.forename: Zhaoyu
authors.initials: Z
authors.lastname: Lin
authors.forename: Philip
authors.initials: P
authors.lastname: Perez
authors.forename: Debin
authors.initials: D
authors.lastname: Lei
authors.forename: Jingyue
authors.initials: J
authors.lastname: Xu
authors.forename: Xiang
authors.initials: X
authors.lastname: Gao
authors.forename: Jianxin
authors.initials: J
authors.lastname: Bao
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D002478:Cells, Cultured / Q000166:cytology; D005260:Female; D005347:Fibroblasts / Q000166:cytology; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D007150:Immunohistochemistry; D057026:Induced Pluripotent Stem Cells / Q000166:cytology* / Q000378:metabolism; D000090062:Kruppel-Like Factor 4; D051741:Kruppel-Like Transcription Factors / Q000235:genetics / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D008819:Mice, Nude; D050814:Octamer Transcription Factor-3 / Q000235:genetics / Q000378:metabolism; D010957:Plasmids / Q000235:genetics / Q000378:metabolism; D016271:Proto-Oncogene Proteins c-myc / Q000235:genetics / Q000378:metabolism; D012190:Retroviridae / Q000235:genetics / Q000378:metabolism; D055748:SOXB1 Transcription Factors / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction; D013724:Teratoma / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D016212:Transforming Growth Factor beta / Q000235:genetics / Q000378:metabolism*
chemical_list: C000715468:Klf4 protein, mouse; D000090062:Kruppel-Like Factor 4; D051741:Kruppel-Like Transcription Factors; C489428:Myc protein, mouse; D050814:Octamer Transcription Factor-3; C494174:Pou5f1 protein, mouse; D016271:Proto-Oncogene Proteins c-myc; D055748:SOXB1 Transcription Factors; C527783:Sox2 protein, mouse; D016212:Transforming Growth Factor beta