Abstract
Interleukin-8 (IL-8) is one of cytokines detected at sites of inflammation and in macrophage-foam cells of atherosclerotic lesions. The expression of IL-8 gene can be induced in cholesterol loaded THP-1 macrophages by oxidized low density lipoprotein. We report for the first time that the expression of human IL-8 gene in THP-1 macrophages is upregulated in a time- and concentration-dependent manner by prostaglandin D2 metabolite 15-deoxy-delta12, 14 prostaglandin J2 (15d-PGJ2), which is a natural ligand for activation of peroxisome proliferator-activated receptor-gamma transcription factor. Studies to identify the signal transduction pathways involved showed that IL-8 upregulation-mediated by 15d-PGJ2 was markedly inhibited when the THP-1 macrophages were incubated with a highly selective and cell-permeable inhibitor of the mitogen-activated protein kinase (MAPK) signaling pathway, 2'-amino-3'-methoxyflavone (PD98059). This inhibition was concentration-dependent, suggesting that 15d-PGJ2 regulates the expression of IL-8 gene in THP-1 macrophages through a MAPK signaling pathway. In contrast, THP-1 macrophages when treated with pyrrolidine dithiocarbamate, an anti-oxidant and the selective inhibitor for nuclear factor kappaB, showed an enhanced 15d-PGJ2-mediated upregulation of IL-8 gene expression. The data presented in this report may contribute to unravel some of the mechanisms behind the inflammatory component of atherosclerosis.
Publication types
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Comparative Study
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Research Support, U.S. Gov't, Non-P.H.S.
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Cholesterol, LDL / drug effects
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Cholesterol, LDL / genetics
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Cholesterol, LDL / metabolism
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Dose-Response Relationship, Drug
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Humans
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Immunologic Factors / pharmacology*
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Interleukin-8 / biosynthesis*
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Interleukin-8 / genetics*
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Macrophages / metabolism*
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Mitogen-Activated Protein Kinases / antagonists & inhibitors
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Mitogen-Activated Protein Kinases / pharmacology
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Muscle, Smooth, Vascular / cytology
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Muscle, Smooth, Vascular / metabolism
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NF-kappa B / biosynthesis
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NF-kappa B / drug effects
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NF-kappa B / genetics
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Prostaglandin D2 / analogs & derivatives*
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Prostaglandin D2 / metabolism*
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Prostaglandin D2 / pharmacology*
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RNA, Messenger / drug effects
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RNA, Messenger / genetics
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RNA, Messenger / metabolism
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Receptors, Cytoplasmic and Nuclear / biosynthesis
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Receptors, Cytoplasmic and Nuclear / drug effects
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Receptors, Cytoplasmic and Nuclear / genetics
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Signal Transduction / drug effects
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Signal Transduction / genetics
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Transcription Factors / biosynthesis
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Transcription Factors / drug effects
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Transcription Factors / genetics
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Tretinoin / pharmacology
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Tumor Cells, Cultured
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Up-Regulation / drug effects
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Up-Regulation / genetics*
Substances
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15-deoxy-delta(12,14)-prostaglandin J2
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Cholesterol, LDL
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Immunologic Factors
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Interleukin-8
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NF-kappa B
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RNA, Messenger
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Receptors, Cytoplasmic and Nuclear
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Transcription Factors
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Tretinoin
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Mitogen-Activated Protein Kinases
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Prostaglandin D2