title: Expression of microRNA-93 and Interleukin-8 during Pseudomonas aeruginosa-mediated induction of proinflammatory responses.
abstract: In this study we analyzed the microRNA profile of cystic fibrosis (CF) bronchial epithelial IB3-1 cells infected with Pseudomonas aeruginosa by microarray and quantitative RT-PCR, demonstrating that microRNA 93 (miR-93), which is highly expressed in basal conditions, decreases during infection in parallel with increased expression of the IL-8 gene. The down-regulation of miR-93 after P. aeruginosa infection was confirmed in other bronchial cell lines derived from subjects with and without CF, namely CuFi-1 and NuLi-1 cells. Sequence analysis shows that the 3'-UTR region of IL-8 mRNA is a potential target of miR-93 and that the consensus sequence is highly conserved throughout molecular evolution. The possible involvement of miR-93 in IL-8 gene regulation was validated using three luciferase vectors, including one carrying the complete 3'-UTR region of the IL-8 mRNA and one carrying the same region with a mutated miR-93 site. Up-modulation of IL-8 after P. aeruginosa infection was counteracted in IB3-1, CuFi-1, and NuLi-1 cells by pre-miR-93 transfection. In addition, IL-8 was up-regulated in uninfected cells treated with antagomiR-93. Our results support the concept of a possible link between microRNA expression and IL-8 induction in bronchial epithelial cells infected with P. aeruginosa. Specifically, the data presented here indicate that, in addition to NF-κB-dependent up-regulation of IL-8 gene transcription, IL-8 protein expression is posttranscriptionally regulated by interactions of the IL-8 mRNA with the inhibitory miR-93.
authors.affiliation: 1 Department of Life Sciences and Biotechnology, Section of Biochemistry and Molecular Biology, and.
authors.forename: Enrica
authors.initials: E
authors.lastname: Fabbri
authors.forename: Monica
authors.initials: M
authors.lastname: Borgatti
authors.forename: Giulia
authors.initials: G
authors.lastname: Montagner
authors.forename: Nicoletta
authors.initials: N
authors.lastname: Bianchi
authors.forename: Alessia
authors.initials: A
authors.lastname: Finotti
authors.forename: Ilaria
authors.initials: I
authors.lastname: Lampronti
authors.forename: Valentino
authors.initials: V
authors.lastname: Bezzerri
authors.forename: Maria Cristina
authors.initials: MC
authors.lastname: Dechecchi
authors.forename: Giulio
authors.initials: G
authors.lastname: Cabrini
authors.forename: Roberto
authors.initials: R
authors.lastname: Gambari
mesh_terms: D020413:3' Untranslated Regions / Q000235:genetics; D001980:Bronchi / Q000382:microbiology; D002460:Cell Line; D003550:Cystic Fibrosis / Q000235:genetics / Q000382:microbiology; D015536:Down-Regulation; D004847:Epithelial Cells / Q000382:microbiology; D005786:Gene Expression Regulation; D006801:Humans; D007249:Inflammation / Q000235:genetics* / Q000382:microbiology*; D016209:Interleukin-8 / Q000235:genetics*; D035683:MicroRNAs / Q000235:genetics*; D064168:Minichromosome Maintenance Complex Component 7 / Q000235:genetics; D016328:NF-kappa B / Q000235:genetics; D011499:Protein Processing, Post-Translational; D011552:Pseudomonas Infections / Q000235:genetics* / Q000382:microbiology; D011550:Pseudomonas aeruginosa; D012333:RNA, Messenger / Q000235:genetics; D014158:Transcription, Genetic; D015854:Up-Regulation
chemical_list: D020413:3' Untranslated Regions; D016209:Interleukin-8; C543350:MIRN93 microRNA, human; D035683:MicroRNAs; D016328:NF-kappa B; D012333:RNA, Messenger; C101624:MCM7 protein, human; D064168:Minichromosome Maintenance Complex Component 7