title: Serratia marcescens serralysin induces inflammatory responses through protease-activated receptor 2.
abstract: The Serratia marcescens-derived protease serralysin is considered to play an important role in the pathogenesis of infection. Protease-activated receptor 2 (PAR-2) is activated by trypsin and also several other trypsin-like serine proteases, leading to the modulation of inflammatory and immune responses. However, little is known about the activation of PAR-2 by bacterial proteases and its roles in bacterial infection. In this study, we investigated whether S. marcescens serralysin activates host inflammatory responses through PAR-2. Our results demonstrated that serralysin induces interleukin-6 (IL-6) and IL-8 mRNA expression in a human lung squamous cell carcinoma, EBC-l cells. In addition, serralysin activated activator protein 1 (AP-1)-, CCAAT/enhancer-binding protein (C/EBP)-, and nuclear factor-kappaB (NF-kappaB)-driven promoters in EBC-1 cells. An electrophoretic mobility shift assay showed that serralysin activates the binding of AP-1, C/EBPbeta, and NF-kappaB in the cells. Inactivation of serralysin resulted in the failure of transactivation of AP-1-, C/EBP-, and NF-kappaB-driven promoters in the cells. Furthermore, serralysin activated AP-1-, C/EBP-, and NF-kappaB-driven promoters via PAR-2 in HeLa cells. PAR-2 antagonist peptides decreased serralysin-induced transactivation of AP-1-, C/EBP-, and NF-kappaB-driven promoters in EBC-1 cells. Considered together, these results suggest that serralysin requires PAR-2 to activate the critical transcription factors AP-1, C/EBPbeta, and NF-kappaB for host inflammatory responses.
authors.affiliation: Department of Bacteriology, Kurume University School of Medicine, 67 Asahi-machi, Kurume, Fukuoka 830-0011, Japan.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Kida
authors.forename: Hiroyoshi
authors.initials: H
authors.lastname: Inoue
authors.forename: Takashi
authors.initials: T
authors.lastname: Shimizu
authors.forename: Koichi
authors.initials: K
authors.lastname: Kuwano
mesh_terms: D022762:CCAAT-Enhancer-Binding Proteins / Q000378:metabolism; D045744:Cell Line, Tumor; D024202:Electrophoretic Mobility Shift Assay; D006367:HeLa Cells; D006801:Humans; D007249:Inflammation / Q000276:immunology* / Q000382:microbiology; D015850:Interleukin-6 / Q000096:biosynthesis; D016209:Interleukin-8 / Q000096:biosynthesis; D008666:Metalloendopeptidases / Q000276:immunology* / Q000378:metabolism; D016328:NF-kappa B / Q000378:metabolism; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000032:analysis; D044464:Receptor, PAR-2 / Q000276:immunology* / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012706:Serratia marcescens / Q000201:enzymology / Q000276:immunology*; D018808:Transcription Factor AP-1 / Q000378:metabolism; D015533:Transcriptional Activation; D014162:Transfection
chemical_list: D022762:CCAAT-Enhancer-Binding Proteins; D015850:Interleukin-6; D016209:Interleukin-8; D016328:NF-kappa B; D012333:RNA, Messenger; D044464:Receptor, PAR-2; D018808:Transcription Factor AP-1; D008666:Metalloendopeptidases; C095666:serralysin