title: MicroRNA regulation via DNA methylation during the morula to blastocyst transition in mice.
abstract: Epigenetic regulation is responsible for transcriptional silencing of genes and parental imprinting. This study addresses the question whether microRNAs (miRNAs) could be affected by DNA methylation during morula-blastocyst transition. Mouse embryos were treated with/without a DNA methyltransferase inhibitor (5-aza-2'-deoxycytidine, 5-aza-dC, 10 nM-5 μM). Changes of miRNAs were analyzed by quantitative real-time (Q-PCR)-based megaplex pre-amp microRNA assays. Development from morula to blastocyst in mice was inhibited by 5-aza-dC in a dose-dependent manner (10 nM-5 μM), with half of the embryos arrested at morula stage when treated with levels of 5-aza-dC as low as 50 nM. In total, 48 down-regulated microRNAs and 17 up-regulated microRNAs (≥5-fold changes) were identified after 5-aza-dC treatment, including let-7e, mir-20a, mir-21, mir-34b, mir-128b and mir-452. Their predicted targets were selected based on software analysis, published databases and further confirmed by Q-PCR. At least eight targets, including dnmt3a, jagged 1, sp1, edg2, abcg4, numa1, tmsb10 and csf1r were confirmed. In conclusion, 5-aza-dC-modified microRNA profiles and identification of the microRNA's targets during the morula to blastocyst stage in mice provide information that helps us to explore the relationship between fertility, microRNA regulation and epigenetic intervention.
authors: Institute of Pharmacology, College of Medicine,  National Yang-Ming University, Taipei,  Taiwan.
authors: Yee-Ming
authors: YM
authors: Lee
authors: Huei-Wen
authors: HW
authors: Chen
authors: Pawan Kumar
authors: PK
authors: Maurya
authors: Ching-Mao
authors: CM
authors: Su
authors: Chii-Ruey
authors: CR
authors: Tzeng
mesh_terms: D000818:Animals; D001374:Azacitidine / Q000031:analogs & derivatives / Q000494:pharmacology; D019175:DNA Methylation; D015254:DNA Modification Methylases / Q000037:antagonists & inhibitors; D000077209:Decitabine; D004622:Embryo, Mammalian / Q000166:cytology; D047108:Embryonic Development / Q000187:drug effects / Q000235:genetics*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D044127:Epigenesis, Genetic; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects; D051379:Mice; D035683:MicroRNAs / Q000235:genetics* / Q000502:physiology
chemical_list: D004791:Enzyme Inhibitors; D035683:MicroRNAs; D000077209:Decitabine; D015254:DNA Modification Methylases; D001374:Azacitidine