IL-6/sIL-6R enhances cathepsin B and L production via caveolin-1-mediated JNK-AP-1 pathway in human gingival fibroblasts.
Interleukin (IL)-6 has an important role in inflammatory diseases. Lysosomal enzymes cathepsins are widely expressed as cysteine proteases regulating inflammatory process. Caveolin-1 (Cav-1) is a scaffolding/regulatory membrane protein that interacts with signaling molecules. In this study, we investigated the role of Cav-1 on (1) the productivity, and (2) the enzymatic activity of cathepsin B and L in human gingival fibroblasts (HGFs) treated with IL-6 in the presence of soluble form of IL-6 receptor (sIL-6R). At first, we established the siRNA-mediated Cav-1 down-regulating in vitro systems by transient transfection of Cav-1 siRNA. The siRNA-mediated Cav-1 down-regulated cells were treated with IL-6/sIL-6R for indicated times. Then, cell lysates were collected, and examined the IL-6-induced signaling pathway, cathepsin B and L production, and measurement of cathepsins activity. To investigate the cathepsin L activity, cathepsin-(B + L) activity was measured after pretreatment with CA-074Me, a specific inhibitor for cathepsin B. We found that IL-6/sIL-6R enhanced significantly both production and activity of cathepsin B and L in HGFs. Interestingly, IL-6-mediated phosphorylation of both p44/42 MAPK and JNK was dramatically suppressed in Cav-1 down-regulated HGFs treated with IL-6/sIL-6R. In addition, both production and activity of cathepsin B and L were also significantly suppressed. Importantly, we demonstrated that JNK inhibition, but not p44/42 MAPK inhibition, significantly diminished IL-6/sIL-6R-induced cathepsin B and L production. Taken together, we concluded that IL-6/sIL-6R enhances cathepsin B and L production via IL-6/sIL-6R-mediated Cav-1-JNK-AP-1 pathway in HGFs. Our findings indicate that Cav-1 might be a therapeutic target for IL-6-mediated tissue degradation in periodontitis.
Department of Pathophysiology-Periodontal Science, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan.
Tomoko
T
Yamaguchi
Koji
K
Naruishi
Hideo
H
Arai
Fusanori
F
Nishimura
Shogo
S
Takashiba
D000873:Anthracenes / Q000494:pharmacology; D002401:Cathepsin B / Q000037:antagonists & inhibitors / Q000378:metabolism*; D056668:Cathepsin L; D002403:Cathepsins / Q000378:metabolism*; D051242:Caveolin 1 / Q000235:genetics / Q000378:metabolism*; D002478:Cells, Cultured; D003546:Cysteine Endopeptidases / Q000378:metabolism*; D004151:Dipeptides / Q000494:pharmacology; D005347:Fibroblasts / Q000187:drug effects / Q000201:enzymology*; D005419:Flavonoids / Q000494:pharmacology; D005881:Gingiva / Q000166:cytology / Q000201:enzymology; D006801:Humans; D015850:Interleukin-6 / Q000378:metabolism*; D048031:JNK Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism; D010518:Periodontitis / Q000201:enzymology / Q000378:metabolism; D010766:Phosphorylation; D011480:Protease Inhibitors / Q000494:pharmacology; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000378:metabolism; D019947:Receptors, Interleukin-6 / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism*; D015398:Signal Transduction; D013997:Time Factors; D018808:Transcription Factor AP-1 / Q000378:metabolism*; D014162:Transfection; D015854:Up-Regulation
D000873:Anthracenes; C400541:CA 074 methyl ester; C495540:CAV1 protein, human; D051242:Caveolin 1; D004151:Dipeptides; D005419:Flavonoids; C508600:IL6 protein, human; C508603:IL6R protein, human; D015850:Interleukin-6; D011480:Protease Inhibitors; D047428:Protein Kinase Inhibitors; D034741:RNA, Small Interfering; D019947:Receptors, Interleukin-6; D011994:Recombinant Proteins; D018808:Transcription Factor AP-1; C432165:pyrazolanthrone; D048031:JNK Mitogen-Activated Protein Kinases; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D002403:Cathepsins; D003546:Cysteine Endopeptidases; D002401:Cathepsin B; C534281:CTSL protein, human; D056668:Cathepsin L; C093973:2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one