title: Nasal mucosal microRNA expression in children with respiratory syncytial virus infection.
abstract: BACKGROUND
  Respiratory syncytial virus (RSV) infection is a common cause of pediatric hospitalization. microRNA, key regulators of the immune system, have not previously been investigated in respiratory specimens during viral infection. We investigated microRNA expression in the nasal mucosa of 42 RSV-positive infants, also comparing microRNA expression between disease severity subgroups.
  
  
  METHODS
  Nasal mucosa cytology specimens were collected from RSV-positive infants and healthy controls. 32 microRNA were selected by microarray for qPCR verification in 19 control, 16 mild, 7 moderate and 19 severe disease samples.
  
  
  RESULTS
  Compared to healthy controls, RSV-positive infants downregulated miR-34b, miR-34c, miR-125b, miR-29c, mir125a, miR-429 and miR-27b and upregulated miR-155, miR-31, miR-203a, miR-16 and let-7d. On disease subgroups analysis, miR-125a and miR-429 were downregulated in mild disease (p=0.03 and 0.02, respectively), but not in severe disease (p=0.3 and 0.3).
  
  
  CONCLUSIONS
  microRNA expression in nasal epithelium cytology brushings of RSV-positive infants shows a distinct profile of immune-associated miRNA. miR-125a has important functions within NF-κB signaling and macrophage function. The lack of downregulation of miR-125a and miR-429 in severe disease may help explain differences in disease manifestations on infection with RSV.
authors.affiliation: Department of Pediatric and Adolescent Medicine, Akershus University Hospital, 1478, Lørenskog, Norway. christopher.inchley@medisin.uio.no.|Institute of Clinical Medicine, University of Oslo, 0316, Oslo, Norway. christopher.inchley@medisin.uio.no.
authors.forename: Christopher S
authors.initials: CS
authors.lastname: Inchley
authors.affiliation: Department of Pediatric and Adolescent Medicine, Akershus University Hospital, 1478, Lørenskog, Norway. Tonje.Sonerud@ahus.no.|Department of Clinical Molecular Biology and Laboratory Sciences (EpiGen), Akershus University Hospital, 1478, Lørenskog, Norway. Tonje.Sonerud@ahus.no.
authors.forename: Tonje
authors.initials: T
authors.lastname: Sonerud
authors.affiliation: Department of Pediatric and Adolescent Medicine, Akershus University Hospital, 1478, Lørenskog, Norway. Hans.Olav.Fjaerli@ahus.no.
authors.forename: Hans O
authors.initials: HO
authors.lastname: Fjærli
authors.affiliation: Department of Pediatric and Adolescent Medicine, Akershus University Hospital, 1478, Lørenskog, Norway. britt.nakstad@medisin.uio.no.|Institute of Clinical Medicine, University of Oslo, 0316, Oslo, Norway. britt.nakstad@medisin.uio.no.
authors.forename: Britt
authors.initials: B
authors.lastname: Nakstad
mesh_terms: D015415:Biomarkers / Q000378:metabolism; D016022:Case-Control Studies; D015536:Down-Regulation; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D035683:MicroRNAs / Q000276:immunology* / Q000378:metabolism; D009297:Nasal Mucosa / Q000276:immunology* / Q000378:metabolism / Q000821:virology; D020411:Oligonucleotide Array Sequence Analysis; D011446:Prospective Studies; D060888:Real-Time Polymerase Chain Reaction; D018357:Respiratory Syncytial Virus Infections / Q000276:immunology* / Q000378:metabolism; D018113:Respiratory Syncytial Virus, Human / Q000276:immunology*; D012720:Severity of Illness Index; D015854:Up-Regulation
chemical_list: D015415:Biomarkers; D035683:MicroRNAs