title: Small RNA-mediated regulation of iPS cell generation.
abstract: Somatic cells can be reprogrammed to an ES-like state to create induced pluripotent stem cells (iPSCs) by ectopic expression of four transcription factors, Oct4, Sox2, Klf4 and cMyc. Here, we show that cellular microRNAs (miRNAs) regulate iPSC generation. Knock-down of key microRNA pathway proteins resulted in significant decreases in reprogramming efficiency. Three miRNA clusters, miR-17∼92, miR-106b∼25 and miR-106a∼363, were shown to be highly induced during early reprogramming stages. Several miRNAs, including miR-93 and miR-106b, which have very similar seed regions, greatly enhanced iPSC induction and modulated mesenchymal-to-epithelial transition step in the initiation stage of reprogramming, and inhibiting these miRNAs significantly decreased reprogramming efficiency. Moreover, miR-iPSC clones reached the fully reprogrammed state. Further analysis revealed that Tgfbr2 and p21 are directly targeted by these miRNAs and that siRNA knock-down of both genes indeed enhanced iPSC induction. Here, for the first time, we demonstrate that miR-93 and its family members directly target TGF-β receptor II to enhance iPSC generation. Overall, we demonstrate that miRNAs function in the reprogramming process and that iPSC induction efficiency can be greatly enhanced by modulating miRNA levels in cells.
authors.affiliation: Program for RNA Biology, Sanford-Burnham Medical Research Institute, La Jolla, CA, USA.
authors.forename: Zhonghan
authors.initials: Z
authors.lastname: Li
authors.forename: Chao-Shun
authors.initials: CS
authors.lastname: Yang
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Nakashima
authors.forename: Tariq M
authors.initials: TM
authors.lastname: Rana
mesh_terms: D000818:Animals; D014408:Biomarkers, Tumor / Q000235:genetics / Q000378:metabolism; D015153:Blotting, Western; D054337:Cell Dedifferentiation; D002454:Cell Differentiation; D049109:Cell Proliferation; D002478:Cells, Cultured; D065150:Cellular Reprogramming; D004622:Embryo, Mammalian / Q000166:cytology / Q000378:metabolism; D053595:Embryonic Stem Cells / Q000502:physiology*; D058750:Epithelial-Mesenchymal Transition; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism; D020869:Gene Expression Profiling; D057026:Induced Pluripotent Stem Cells / Q000166:cytology* / Q000502:physiology*; D000090062:Kruppel-Like Factor 4; D008156:Luciferases / Q000378:metabolism; D051379:Mice; D008819:Mice, Nude; D035683:MicroRNAs / Q000502:physiology*; D009687:Nuclear Proteins / Q000502:physiology; D020411:Oligonucleotide Array Sequence Analysis; D012323:RNA Processing, Post-Transcriptional; D012333:RNA, Messenger / Q000235:genetics; D034741:RNA, Small Interfering; D018125:Receptors, Transforming Growth Factor beta / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013724:Teratoma / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D014158:Transcription, Genetic; D016212:Transforming Growth Factor beta / Q000235:genetics / Q000378:metabolism
chemical_list: D014408:Biomarkers, Tumor; C000715468:Klf4 protein, mouse; D000090062:Kruppel-Like Factor 4; D035683:MicroRNAs; D009687:Nuclear Proteins; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D018125:Receptors, Transforming Growth Factor beta; D016212:Transforming Growth Factor beta; D008156:Luciferases