51. Activation of toll-like receptor-9 induces matrix metalloproteinase-9 expression through Akt and tumor necrosis factor-α signaling
- Author
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Jin-Gu Lee, ChuHee Lee, Suk-Hwan Baek, Byung-Ro Chin, Yoe-Sik Bae, Jae-Ryong Kim, Sun-Hye Lee, and Eun-Jung Lim
- Subjects
MAPK/ERK pathway ,CpG oligodeoxunucleotide ,Tumor necrosis factor ,CpG Oligodeoxynucleotide ,Biophysics ,Biochemistry ,Cell Line ,Mice ,Adjuvants, Immunologic ,Toll-like receptor ,Structural Biology ,Genetics ,Animals ,Receptors, Tumor Necrosis Factor, Type II ,Molecular Biology ,Protein kinase B ,PI3K/AKT/mTOR pathway ,Tumor Necrosis Factor-alpha ,Chemistry ,Macrophages ,Akt ,hemic and immune systems ,Cell Biology ,respiratory system ,Molecular biology ,Cell biology ,Toll-Like Receptor 9 ,Matrix metalloproteinase ,Matrix Metalloproteinase 9 ,Oligodeoxyribonucleotides ,CpG site ,Receptors, Tumor Necrosis Factor, Type I ,Enzyme Induction ,Signal transduction ,Proto-Oncogene Proteins c-akt ,Signal Transduction - Abstract
CpG oligodeoxunucleotide (ODN) plays an important role in immune cell function. The present study examined whether temporal control of toll-like receptor (TLR)-9 by CpG ODN can regulate the expression of matrix metalloproteinase-9 (MMP-9). CpG ODN induced the release of tumor necrosis factor (TNF)-alpha and the expression of TNF receptor (TNFR)-II, but not of TNFR-I, in a time-dependent manner and stimulated significant, though delayed, MMP-9 expression. The endosomal acidification inhibitors, chloroquine or bafilomycin A, inhibited CpG ODN-induced TNF-alpha, TNFR-II, and MMP-9 expression. CpG ODN induced the phosphorylation of Akt, and the inhibition of Akt by LY294002 suppressed CpG ODN-induced TNF-alpha, TNFR-II, and MMP-9 expressions. Moreover, neutralizing TNF-alpha antibody significantly suppressed CpG ODN-induced MMP-9 expression, suggesting the involvement of TNF-alpha. These observations suggest that CpG ODN may play important roles in macrophage activation by regulating the expression of MMP-9 via a TLR-9/Akt/TNF-alpha-dependent signaling pathway.
- Published
- 2006
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