title: MicroRNA-302 increases reprogramming efficiency via repression of NR2F2.
abstract: MicroRNAs (miRNAs) have emerged as critical regulators of gene expression through translational inhibition and RNA decay and have been implicated in the regulation of cellular differentiation, proliferation, angiogenesis, and apoptosis. In this study, we analyzed global miRNA and mRNA microarrays to predict novel miRNA-mRNA interactions in human embryonic stem cells and induced pluripotent stem cells (iPSCs). In particular, we demonstrate a regulatory feedback loop between the miR-302 cluster and two transcription factors, NR2F2 and OCT4. Our data show high expression of miR-302 and OCT4 in pluripotent cells, while NR2F2 is expressed exclusively in differentiated cells. Target analysis predicts that NR2F2 is a direct target of miR-302, which we experimentally confirm by reporter luciferase assays and real-time polymerase chain reaction. We also demonstrate that NR2F2 directly inhibits the activity of the OCT4 promoter and thus diminishes the positive feedback loop between OCT4 and miR-302. Importantly, higher reprogramming efficiencies were obtained when we reprogrammed human adipose-derived stem cells into iPSCs using four factors (KLF4, C-MYC, OCT4, and SOX2) plus miR-302 (this reprogramming cocktail is hereafter referred to as "KMOS3") when compared to using four factors ("KMOS"). Furthermore, shRNA knockdown of NR2F2 mimics the over-expression of miR-302 by also enhancing reprogramming efficiency. Interestingly, we were unable to generate iPSCs from miR-302a/b/c/d alone, which is in contrast to previous publications that have reported that miR-302 by itself can reprogram human skin cancer cells and human hair follicle cells. Taken together, these findings demonstrate that miR-302 inhibits NR2F2 and promotes pluripotency through indirect positive regulation of OCT4. This feedback loop represents an important new mechanism for understanding and inducing pluripotency in somatic cells.
authors.affiliation: Department of Medicine, Division of Cardiology, Stanford University, Stanford, California, USA.
authors.forename: Shijun
authors.initials: S
authors.lastname: Hu
authors.forename: Kitchener D
authors.initials: KD
authors.lastname: Wilson
authors.forename: Zhumur
authors.initials: Z
authors.lastname: Ghosh
authors.forename: Leng
authors.initials: L
authors.lastname: Han
authors.forename: Yongming
authors.initials: Y
authors.lastname: Wang
authors.forename: Feng
authors.initials: F
authors.lastname: Lan
authors.forename: Katherine J
authors.initials: KJ
authors.lastname: Ransohoff
authors.forename: Paul
authors.initials: P
authors.lastname: Burridge
authors.forename: Joseph C
authors.initials: JC
authors.lastname: Wu
mesh_terms: D017667:Adipocytes / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D051837:COUP Transcription Factor II / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D002454:Cell Differentiation / Q000187:drug effects; D065150:Cellular Reprogramming / Q000187:drug effects / Q000235:genetics; D025461:Feedback, Physiological; D005260:Female; D005786:Gene Expression Regulation / Q000187:drug effects; D017930:Genes, Reporter; D006801:Humans; D057026:Induced Pluripotent Stem Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D000090062:Kruppel-Like Factor 4; D051741:Kruppel-Like Transcription Factors / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology; D008156:Luciferases; D035683:MicroRNAs / Q000235:genetics* / Q000378:metabolism / Q000494:pharmacology; D046228:Microarray Analysis; D050814:Octamer Transcription Factor-3 / Q000235:genetics* / Q000378:metabolism / Q000494:pharmacology; D061251:Primary Cell Culture; D011401:Promoter Regions, Genetic; D016271:Proto-Oncogene Proteins c-myc / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology; D034741:RNA, Small Interfering / Q000235:genetics; D055748:SOXB1 Transcription Factors / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology; D015398:Signal Transduction / Q000187:drug effects
chemical_list: D051837:COUP Transcription Factor II; D000090062:Kruppel-Like Factor 4; D051741:Kruppel-Like Transcription Factors; D008156:Luciferases; D035683:MicroRNAs; D050814:Octamer Transcription Factor-3; D016271:Proto-Oncogene Proteins c-myc; D034741:RNA, Small Interfering; D055748:SOXB1 Transcription Factors; C000715467:KLF4 protein, human; C532169:MIRN302A microRNA, human; C489427:MYC protein, human; C494173:POU5F1 protein, human; C527782:SOX2 protein, human; C095569:NR2F2 protein, human