title: Regulation of expression of matrix metalloproteinase-9 by JNK in Raw 264.7 cells: presence of inhibitory factor(s) suppressing MMP-9 induction in serum and conditioned media.
abstract: Matrix metalloproteinase-9 (MMP-9) secreted from macrophages plays an important role in tissue destruction and inflammation through degradation of matrix proteins and proteolytic activation of cytokines/chemokines. Whereas the MEK-ERK and PI3K- Akt pathways up-regulate MMP-9 expression, regulation of MMP-9 by JNK remains controversial. Presently, we aimed to determine the role of JNK in MMP-9 regulation in Raw 264.7 cells. Inhibition of JNK by the JNK inhibitor SP600125 induced MMP-9 in the absence of serum and suppressed the expression of TNF-alpha, IL-6 and cyclooxygenase-2 in LPS-treated Raw 264.7 cells. In a knockdown experiment with small interfering RNA, suppression of JNK1 induced MMP-9 expression. Interestingly, mouse serum suppressed SP600125- mediated MMP-9 induction, similar to IFN-gamma. However, the inhibitory activity of mouse serum was not affected by pyridone 6, which inhibits Janus kinase downstream to IFN-gamma. In addition to mouse serum, conditioned media of Raw 264.7 cells contained the inhibitory factor(s) larger than 10 kDa, which suppressed SP600125- or LPS-induced MMP-9 expression. Taken together, these data suggest that JNK1 suppresses MMP-9 expression in the absence of serum. In addition, the inhibitory factor(s) present in serum or secreted from macrophages may negatively control MMP-9 expression.
authors.affiliation: Department of Molecular Cell Biology, Sungkyunkwan University School of Medicine, Suwon 440-746, Korea. yslee@skku.edu
authors.forename: Yun Song
authors.initials: YS
authors.lastname: Lee
authors.forename: Huong Thi
authors.initials: HT
authors.lastname: Lan Tran
authors.forename: Quang
authors.initials: Q
authors.lastname: Van Ta
mesh_terms: D000818:Animals; D000873:Anthracenes / Q000378:metabolism; D002460:Cell Line; D017077:Culture Media, Conditioned / Q000737:chemistry*; D004789:Enzyme Activation; D004790:Enzyme Induction; D004791:Enzyme Inhibitors / Q000378:metabolism; D048049:Extracellular Signal-Regulated MAP Kinases / Q000235:genetics / Q000378:metabolism; D015971:Gene Expression Regulation, Enzymologic; D020935:MAP Kinase Signaling System / Q000502:physiology; D008264:Macrophages / Q000166:cytology / Q000378:metabolism*; D020780:Matrix Metalloproteinase 9 / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D048055:Mitogen-Activated Protein Kinase 8 / Q000235:genetics / Q000378:metabolism*; D016328:NF-kappa B / Q000235:genetics / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt / Q000235:genetics / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D048051:p38 Mitogen-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism
chemical_list: D000873:Anthracenes; D017077:Culture Media, Conditioned; D004791:Enzyme Inhibitors; D016328:NF-kappa B; D014409:Tumor Necrosis Factor-alpha; C432165:pyrazolanthrone; D051057:Proto-Oncogene Proteins c-akt; D048049:Extracellular Signal-Regulated MAP Kinases; D048055:Mitogen-Activated Protein Kinase 8; D048051:p38 Mitogen-Activated Protein Kinases; D020780:Matrix Metalloproteinase 9