title: MicroRNA-146a induction during influenza H3N2 virus infection targets and regulates TRAF6 levels in human nasal epithelial cells (hNECs).
abstract: We have previously shown that human nasal epithelial cells (hNECs) are highly permissive cells for respiratory viruses including influenza A virus (IAV) and respiratory syncytial virus. Recent studies have indicated that microRNAs (miRNAs) are involved in virus-host relationship, and this led us to investigate its essential roles in the in vitro hNECs model derived from multiple donors. By comparing the differential expression of miRNAs upon IAV infection among animal and cell line studies, candidates were selected with focus on the initial immune response. After infection of influenza H3N2 virus, hNECs showed constant increase virus titer at 24-72h post-infection (hpi); accompanied with a significantly elevated level of miR-146a-5p at 72 hpi. The exponential elevation of progeny virus titer correlated with a key influenza sensing Toll-like receptor (TLR)7 pathway. TLR7 downstream gene transcripts, myeloid differentiation primary response gene 88 (MyD88), interferon regulator factor 7 (IRF7), and interferon-β (IFN-β) were significantly upregulated at 48 and 72 hpi, while interleukin-1 receptor-associated kinase 1 (IRAK1) and TNF receptor associated factor-6 (TRAF6) were unchanged. Interestingly, when miR-146a was overexpressed with miRNA mimics prior to H3N2 infection, further decreased transcripts of TRAF6, but not IRAK1, were detected. By using the in vitro hNEC model, we demonstrated that H3N2-induced miR-146a specifically targets and regulates TRAF6 expression; but not IRAK expression in the nasal epithelium. We also found that unlike the cell model studies that lead to our studies, when ran across a heterogeneous model of different individual, miRNA signals were highly varied and the expression of most miRNAs, including miR-146a-5p, was more subdued compared to homogenous cell line model, highlighting a need for a more thorough analysis of miRNA signals and targets in a model more mimicking a clinical influenza infection.
authors.affiliation: Department of Otolaryngology, Renmin Hospital of Wuhan University, Wuhan 430060, Hubei Province, PR China; Department of Otolaryngology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
authors.forename: Yuqin
authors.initials: Y
authors.lastname: Deng
authors.affiliation: Department of Otolaryngology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
authors.forename: Yan
authors.initials: Y
authors.lastname: Yan
authors.affiliation: Department of Otolaryngology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
authors.forename: Kai Sen
authors.initials: KS
authors.lastname: Tan
authors.affiliation: Department of Otolaryngology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
authors.forename: Jing
authors.initials: J
authors.lastname: Liu
authors.affiliation: Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
authors.forename: Vincent T
authors.initials: VT
authors.lastname: Chow
authors.affiliation: Department of Otolaryngology, Renmin Hospital of Wuhan University, Wuhan 430060, Hubei Province, PR China. Electronic address: taozezhang@163.com.
authors.forename: Ze-Zhang
authors.initials: ZZ
authors.lastname: Tao
authors.affiliation: Department of Otolaryngology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore. Electronic address: entwdy@nus.edu.sg.
authors.forename: De-Yun
authors.initials: DY
authors.lastname: Wang
mesh_terms: D000328:Adult; D000368:Aged; D000818:Animals; D004285:Dogs; D005260:Female; D006801:Humans; D053122:Influenza A Virus, H3N2 Subtype; D007251:Influenza, Human / Q000235:genetics* / Q000378:metabolism; D050839:Interferon Regulatory Factor-7 / Q000235:genetics / Q000378:metabolism; D016899:Interferon-beta / Q000235:genetics / Q000378:metabolism; D053592:Interleukin-1 Receptor-Associated Kinases / Q000235:genetics / Q000378:metabolism; D047908:Intracellular Signaling Peptides and Proteins; D061985:Madin Darby Canine Kidney Cells; D008297:Male; D035683:MicroRNAs / Q000235:genetics*; D053594:Myeloid Differentiation Factor 88 / Q000235:genetics / Q000378:metabolism; D020545:Respiratory Mucosa / Q000378:metabolism*; D048029:TNF Receptor-Associated Factor 6 / Q000235:genetics / Q000378:metabolism*; D051199:Toll-Like Receptor 7 / Q000235:genetics / Q000378:metabolism
chemical_list: C494234:IRF7 protein, human; D050839:Interferon Regulatory Factor-7; D047908:Intracellular Signaling Peptides and Proteins; C542542:MIRN146 microRNA, human; C507779:MYD88 protein, human; D035683:MicroRNAs; D053594:Myeloid Differentiation Factor 88; C495348:TLR7 protein, human; D048029:TNF Receptor-Associated Factor 6; C000604754:Tifab protein, human; D051199:Toll-Like Receptor 7; D016899:Interferon-beta; C507768:IRAK1 protein, human; D053592:Interleukin-1 Receptor-Associated Kinases
keywords: Human nasal epithelial cells (hNECs); Influenza H3N2 virus; Innate immunity; MicroRNA-146a-5p; TNF receptor associated factor-6 (TRAF6)