Synthetic double-stranded RNA induces interleukin-32 in bronchial epithelial cells

Kyoko Ota, Mio Kawaguchi, Junichi Fujita, Fumio Kokubu, Shau Ku Huang, Yuko Morishima, Satoshi Matsukura, Masatsugu Kurokawa, Yukio Ishii, Hiroaki Satoh, Tohru Sakamoto, Nobuyuki Hizawa

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11 Citations (Scopus)

Abstract

Objective: Interleukin (IL)-32 is a novel cytokine and is involved in the pathogenesis of various inflammatory diseases, including asthma and COPD. However, the regulatory mechanisms of IL-32 expression and its precise pathogenic role remain to be defined. Given that viral infections are known to potentially cause and exacerbate airway inflammation, in this study, we investigated the expression of IL-32 induced by synthetic double-stranded (ds) RNA, and its signaling mechanisms involved. Methods: Bronchial epithelial cells were stimulated with synthetic dsRNA poly I:C. The levels of IL-32 expression were analyzed using real-time PCR and ELISA. The involvement of transforming growth factor β-activated kinase 1 (TAK1) and a subunit of nuclear factor-κB (NF-κB), p65 was determined by western blot analyses. TAK1 inhibitor, 5Z-7-Oxozeaenol and NF-κB inhibitor, BAY 11-7082 were added to the culture to identify key signaling events leading to the expression of IL-32. Finally, the effect of short interfering RNAs (siRNAs) targeting TAK1 and p65 was investigated. Results: dsRNA significantly induced IL-32 gene and protein expression, concomitant with activation of TAK1 and p65. Pretreatment of 5Z-7-Oxozeaenol diminished dsRNA-induced phosphorylation of NF-κB. Both 5Z-7-Oxozeaenol and BAY 11-7082 significantly abrogated dsRNA-induced IL-32 production. Moreover, transfection of the cells with siRNAs targeting TAK1 and p65 inhibited the expression of IL-32. Conclusions: The expression of IL-32 is induced by dsRNA via the TAK1-NF-κB signaling pathway in bronchial epithelial cells. IL-32 is involved in the pathogenesis of airway inflammation, and may be a novel therapeutic target for airway inflammatory diseases.

Original languageEnglish
Pages (from-to)335-343
Number of pages9
JournalExperimental Lung Research
Volume41
Issue number6
DOIs
Publication statusPublished - Jan 1 2015
Externally publishedYes

Keywords

  • bronchial epithelial cell
  • dsRNA
  • IL-32
  • NF-κB
  • p65
  • TAK1

ASJC Scopus subject areas

  • Molecular Biology
  • Pulmonary and Respiratory Medicine
  • Clinical Biochemistry

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  • Cite this

    Ota, K., Kawaguchi, M., Fujita, J., Kokubu, F., Huang, S. K., Morishima, Y., Matsukura, S., Kurokawa, M., Ishii, Y., Satoh, H., Sakamoto, T., & Hizawa, N. (2015). Synthetic double-stranded RNA induces interleukin-32 in bronchial epithelial cells. Experimental Lung Research, 41(6), 335-343. https://doi.org/10.3109/01902148.2015.1033569