title: Upregulation of matrix metalloproteinase expression by poly(I:C) in corneal fibroblasts: role of NF-κB and interleukin-1ß.
abstract: OBJECTIVE
  To characterize the mechanism of corneal ulceration associated with viral keratitis, the authors investigated the effects of polyinosinic-polycytidylic acid [poly(I:C)], a synthetic analog of viral double-stranded RNA, on the expression of matrix metalloproteinases (MMPs) in human corneal fibroblasts.
  
  
  METHODS
  The expression of MMPs in human corneal fibroblasts cultured in the absence or presence of poly(I:C) was examined by immunoblot analysis, gelatin zymography, and quantitative reverse transcription-polymerase chain reaction analysis. The phosphorylation of the NF-κB inhibitor protein IκB-α was assessed by immunoblot analysis, and the concentration of interleukin (IL)-1β in culture supernatants was measured by enzyme-linked immunosorbent assay.
  
  
  RESULTS
  Poly(I:C) increased the expression of MMP-1 and MMP-3 in corneal fibroblasts at the mRNA and protein levels. It also induced the phosphorylation of IκB-α and the secretion of IL-1β in these cells. The poly(I:C)-induced expression of MMP-1 and MMP-3 was attenuated by a synthetic inhibitor of NF-κB signaling and by IL-1 receptor antagonist; the latter also inhibited poly(I:C)-induced phosphorylation of IκB-α.
  
  
  CONCLUSIONS
  Poly(I:C) induces the expression of MMP-1 and MMP-3 in human corneal fibroblasts in a manner dependent on activation of the transcription factor NF-κB and on IL-1β secretion. These effects may play an important role in corneal ulceration associated with viral keratitis.
authors.affiliation: Department of Ocular Pathophysiology, Yamaguchi University School of Medicine, Yamaguchi, Japan. k.kimura@yamaguchi-u.ac.jp
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Kimura
authors.forename: Tomoko
authors.initials: T
authors.lastname: Orita
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Kondo
authors.forename: Hongyan
authors.initials: H
authors.lastname: Zhou
authors.forename: Teruo
authors.initials: T
authors.lastname: Nishida
mesh_terms: D000998:Antiviral Agents / Q000494:pharmacology*; D002478:Cells, Cultured; D003315:Cornea / Q000187:drug effects* / Q000201:enzymology; D004797:Enzyme-Linked Immunosorbent Assay; D005347:Fibroblasts / Q000187:drug effects / Q000201:enzymology; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects*; D006801:Humans; D020672:I-kappa B Proteins / Q000378:metabolism; D015151:Immunoblotting; D053583:Interleukin-1beta / Q000378:metabolism*; D020781:Matrix Metalloproteinase 1 / Q000235:genetics / Q000378:metabolism; D019278:Matrix Metalloproteinase 3 / Q000235:genetics / Q000378:metabolism; D020782:Matrix Metalloproteinases / Q000235:genetics* / Q000378:metabolism; D000072000:NF-KappaB Inhibitor alpha; D016328:NF-kappa B / Q000378:metabolism*; D010766:Phosphorylation; D011070:Poly I-C / Q000494:pharmacology*; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015854:Up-Regulation
chemical_list: D000998:Antiviral Agents; D020672:I-kappa B Proteins; D053583:Interleukin-1beta; D016328:NF-kappa B; C000606204:NFKBIA protein, human; D012333:RNA, Messenger; D000072000:NF-KappaB Inhibitor alpha; D020782:Matrix Metalloproteinases; D019278:Matrix Metalloproteinase 3; D020781:Matrix Metalloproteinase 1; D011070:Poly I-C