title: MicroRNA miR-27 Inhibits Adenovirus Infection by Suppressing the Expression of SNAP25 and TXN2.
abstract: Recent studies have reported that host microRNAs (miRNAs) regulate infections by several types of viruses via various mechanisms and that inhibition of the miRNA processing factors enhances or prevents viral infection. However, it has not been clarified whether these effects of miRNAs extend to adenovirus (Ad) infection. Here we show that miR-27a and -b efficiently inhibit infection with an Ad via the downregulation of SNAP25 and TXN2, which are members of the SNARE proteins and the thioredoxin family, respectively. Approximately 80% reductions in Ad genomic copy number were found in cells transfected with miR-27a/b mimics, whereas there were approximately 2.5- to 5-fold larger copy numbers of the Ad genome following transfection with miR-27a/b inhibitors. Microarray gene expression analysis andin silicoanalysis demonstrated that SNAP25 and TXN2 are target genes of miR-27a/b. A reporter assay using plasmids containing the 3' untranslated regions of the SNAP25 and TXN2 genes showed that miR-27a/b directly suppressed SNAP25 and TXN2 expression through posttranscriptional gene silencing. Knockdown of SNAP25 led to a significant inhibition of Ad entry into cells. Knockdown of TXN2 induced cell cycle arrest at G1phase, leading to a reduction in Ad replication. In addition, overexpression of Ad-encoded small noncoding RNAs (VA-RNAs) restored the miR-27a/b-mediated reduction in infection level with a VA-RNA-lacking Ad mutant due to the VA-RNA-mediated inhibition of miR-27a/b expression. These results indicate that miR-27a and -b suppress SNAP25 and TXN2 expression via posttranscriptional gene silencing, leading to efficient suppression of Ad infection.IMPORTANCEAdenovirus (Ad) is widely used as a platform for replication-incompetent Ad vectors (Adv) and replication-competent oncolytic Ad (OAd) in gene therapy and virotherapy. Regulation of Ad infection is highly important for efficient gene therapies using both Adv and OAd. In this study, we demonstrate that miR-27a and -b, which are widely expressed in host cells, suppress SNAP25 and TXN2 expression through posttranscriptional gene silencing. Suppression of SNAP25 and TXN2 expression leads to inhibition of Ad entry into cells and to cell cycle arrest, respectively, leading to efficient suppression of Ad infection. Our findings provide important clues to the improvement of gene therapies using both Adv and OAd.
authors.affiliation: Laboratory of Biochemistry and Molecular Biology, Graduate School of Pharmaceutical Sciences, Osaka University, Suita, Osaka, Japan.|Institute for Frontier Life and Medical Sciences, Kyoto University, Sakyo-ku, Kyoto, Japan.
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Machitani
authors.affiliation: Laboratory of Biochemistry and Molecular Biology, Graduate School of Pharmaceutical Sciences, Osaka University, Suita, Osaka, Japan sakurai@phs.osaka-u.ac.jp mizuguch@phs.osaka-u.ac.jp.|Laboratory of Regulatory Sciences for Oligonucleotide Therapeutics, Clinical Drug Development Unit, Graduate School of Pharmaceutical Sciences, Osaka University, Suita, Osaka, Japan.
authors.forename: Fuminori
authors.initials: F
authors.lastname: Sakurai
authors.affiliation: Laboratory of Biochemistry and Molecular Biology, Graduate School of Pharmaceutical Sciences, Osaka University, Suita, Osaka, Japan.
authors.forename: Keisaku
authors.initials: K
authors.lastname: Wakabayashi
authors.affiliation: Laboratory of Biochemistry and Molecular Biology, Graduate School of Pharmaceutical Sciences, Osaka University, Suita, Osaka, Japan.
authors.forename: Kosuke
authors.initials: K
authors.lastname: Nakatani
authors.affiliation: Laboratory of Biochemistry and Molecular Biology, Graduate School of Pharmaceutical Sciences, Osaka University, Suita, Osaka, Japan.
authors.forename: Masashi
authors.initials: M
authors.lastname: Tachibana
authors.affiliation: Laboratory of Biochemistry and Molecular Biology, Graduate School of Pharmaceutical Sciences, Osaka University, Suita, Osaka, Japan sakurai@phs.osaka-u.ac.jp mizuguch@phs.osaka-u.ac.jp.|Laboratory of Hepatocyte Regulation, National Institutes of Biomedical Innovation, Health and Nutrition, Asagi, Ibaraki, Osaka, Japan.|iPS Cell-Based Research Project on Hepatic Toxicity and Metabolism, Graduate School of Pharmaceutical Sciences, Osaka University, Suita, Osaka, Japan.|Global Center for Medical Engineering and Informatics, Osaka University, Suita, Osaka, Japan.|Graduate School of Medicine, Osaka University, Suita, Osaka, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Mizuguchi
mesh_terms: D049109:Cell Proliferation; D003198:Computer Simulation; D015536:Down-Regulation; D018628:Gene Dosage; D055785:Gene Knockdown Techniques; D005822:Genetic Vectors / Q000235:genetics; D006367:HeLa Cells; D006801:Humans; D035683:MicroRNAs / Q000235:genetics*; D046228:Microarray Analysis; D024101:Mitochondrial Proteins / Q000235:genetics*; D034622:RNA Interference; D058727:RNA, Small Untranslated; D050825:Synaptosomal-Associated Protein 25 / Q000235:genetics*; D013879:Thioredoxins / Q000235:genetics*; D014162:Transfection
chemical_list: C531388:MIRN27 microRNA, human; D035683:MicroRNAs; D024101:Mitochondrial Proteins; D058727:RNA, Small Untranslated; C494208:SNAP25 protein, human; D050825:Synaptosomal-Associated Protein 25; C467002:TXN2 protein, human; D013879:Thioredoxins
keywords: SNAP25; TXN2; adenoviruses; miR-27; posttranscriptional gene silencing