MiR-25 regulates Wwp2 and Fbxw7 and promotes reprogramming of mouse fibroblast cells to iPSCs.
BACKGROUND
miRNAs are a class of small non-coding RNAs that regulate gene expression and have critical functions in various biological processes. Hundreds of miRNAs have been identified in mammalian genomes but only a small number of them have been functionally characterized. Recent studies also demonstrate that some miRNAs have important roles in reprogramming somatic cells to induced pluripotent stem cells (iPSCs).


METHODS
We screened 52 miRNAs cloned in a piggybac (PB) vector for their roles in reprogramming of mouse embryonic fibroblast cells to iPSCs. To identify targets of miRNAs, we made Dgcr8-deficient embryonic stem (ES) cells and introduced miRNA mimics to these cells, which lack miRNA biogenesis. The direct target genes of miRNA were identified through global gene expression analysis and target validation.


CONCLUSIONS
We found that over-expressing miR-25 or introducing miR-25 mimics enhanced production of iPSCs. We identified a number of miR-25 candidate gene targets. Of particular interest were two ubiquitin ligases, Wwp2 and Fbxw7, which have been proposed to regulate Oct4, c-Myc and Klf5, respectively. Our findings thus highlight the complex interplay between miRNAs and transcription factors involved in reprogramming, stem cell self-renewal and maintenance of pluripotency.
Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, United Kingdom.
Dong
D
Lu
Matthew P A
MP
Davis
Cei
C
Abreu-Goodger
Wei
W
Wang
Lia S
LS
Campos
Julia
J
Siede
Elena
E
Vigorito
William C
WC
Skarnes
Ian
I
Dunham
Anton J
AJ
Enright
Pentao
P
Liu
D000818:Animals; D001483:Base Sequence; D065150:Cellular Reprogramming / Q000235:genetics*; D019295:Computational Biology; D044783:F-Box Proteins / Q000235:genetics*; D000073979:F-Box-WD Repeat-Containing Protein 7; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism*; D005786:Gene Expression Regulation; D057026:Induced Pluripotent Stem Cells / Q000166:cytology*; D051379:Mice; D035683:MicroRNAs / Q000235:genetics* / Q000378:metabolism*; D044767:Ubiquitin-Protein Ligases / Q000235:genetics*
D044783:F-Box Proteins; D000073979:F-Box-WD Repeat-Containing Protein 7; C513272:Fbxw7 protein, mouse; C558895:MIRN25 microRNA, mouse; D035683:MicroRNAs; C487995:Wwp2 protein, mouse; D044767:Ubiquitin-Protein Ligases