title: Specificity, duplex degradation and subcellular localization of antagomirs.
abstract: MicroRNAs (miRNAs) are an abundant class of 20-23-nt long regulators of gene expression. The study of miRNA function in mice and potential therapeutic approaches largely depend on modified oligonucleotides. We recently demonstrated silencing miRNA function in mice using chemically modified and cholesterol-conjugated RNAs termed 'antagomirs'. Here, we further characterize the properties and function of antagomirs in mice. We demonstrate that antagomirs harbor optimized phosphorothioate modifications, require >19-nt length for highest efficiency and can discriminate between single nucleotide mismatches of the targeted miRNA. Degradation of different chemically protected miRNA/antagomir duplexes in mouse livers and localization of antagomirs in a cytosolic compartment that is distinct from processing (P)-bodies indicates a degradation mechanism independent of the RNA interference (RNAi) pathway. Finally, we show that antagomirs, although incapable of silencing miRNAs in the central nervous system (CNS) when injected systemically, efficiently target miRNAs when injected locally into the mouse cortex. Our data further validate the effectiveness of antagomirs in vivo and should facilitate future studies to silence miRNAs for functional analysis and in clinically relevant settings.
authors: Laboratory of Metabolic Diseases, The Rockefeller University, 1230 York Avenue, New York, NY 10021, USA.
authors: Jan
authors: J
authors: Krützfeldt
authors: Satoru
authors: S
authors: Kuwajima
authors: Ravi
authors: R
authors: Braich
authors: Kallanthottathil G
authors: KG
authors: Rajeev
authors: John
authors: J
authors: Pena
authors: Thomas
authors: T
authors: Tuschl
authors: Muthiah
authors: M
authors: Manoharan
authors: Markus
authors: M
authors: Stoffel
mesh_terms: D000818:Animals; D000070416:Antagomirs; D020137:Base Pair Mismatch; D002540:Cerebral Cortex / Q000378:metabolism; D020868:Gene Silencing; D007267:Injections; D007700:Kinetics; D051379:Mice; D008810:Mice, Inbred C57BL; D035683:MicroRNAs / Q000378:metabolism*; D009841:Oligonucleotides / Q000008:administration & dosage* / Q000032:analysis / Q000737:chemistry*; D013873:Thionucleotides / Q000737:chemistry
chemical_list: D000070416:Antagomirs; D035683:MicroRNAs; D009841:Oligonucleotides; D013873:Thionucleotides; C520440:antagomir-122