Induction of cyclooxygenase-2 in macrophages by catalase: role of NF-κB and PI3K signaling pathways

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Abstract

Induction of COX-2 by catalase in smooth muscle cells, endothelial cells, and neuronal cells has been previously reported. However, the mechanism by which catalase up-regulates COX-2 remains poorly understood. In this study, we investigated the effect of catalase on induction of COX-2 in macrophages. The addition of catalase into Raw 264.7 macrophages induced COX-2 expression that was correlated with increased COX-2 transcription and mRNA stability. Catalase also induced activation of NF-κB, PI3K, ERKs, p38s, or JNKs. Catalase-induced COX-2 expression was abrogated by treatment of MG-132 (a NF-κB inhibitor) or LY294002 (a PI3K inhibitor), but not by treatment of PD98059 (an ERK inhibitor), SB203580 (a p38 inhibitor), or SP600125 (a JNK inhibitor). Moreover, inhibition of PI3K by LY294002 caused partial decrease of catalase-induced COX-2 transcription and steady-state COX-2 transcript levels, but not COX-2 mRNA stability. Together, these results suggest that catalase induces the expression of COX-2 in Raw 264.7 macrophages, and the induction is related with activation of NF-κB transcription factor and PI3K signaling pathway.

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Materials and methods

Materials. Catalase (C-40), aprotinin, leupeptin, and 3-amino-1,2,4-triazole (AT) were purchased from Sigma. Antibodies against anti-rabbit or mouse secondary horseradish peroxidase and ECL Western detection reagents were purchased from Amersham Biosciences. PD98059 (an ERK inhibitor), SB203580 (a p38 inhibitor), LY294002 (a PI3K inhibitor), SP600125 (a JNK inhibitor), Z-Leu-Leu-Leu-H (MG132, a proteosomal and NF-κB inhibitor), rapamycin (an inhibitor of mammalian target of rapamycin/S6 kinase

Induction of COX-2 in Raw 264.7 macrophages by catalase

We initially investigated the effect of different concentrations of catalase on COX-2 protein and mRNA expression in Raw cells. As shown in Fig. 1A, the addition of catalase into Raw cells for 6 h induced a dose-dependent increase of COX-2 protein and mRNA. There were already substantial amounts of COX-2 protein and mRNA expression by treatment with catalase at 100 U/ml. Expression levels of COX-2 protein and mRNA were further elevated as treatment doses of catalase were increased. Data of

Discussion

In this study, we have demonstrated that catalase induces the expression of COX-2 in Raw 264.7 macrophages. Furthermore, we have shown that the COX-2 induction by catalase in Raw cells requires its enzymatic activity, based on the fact that catalase, which lost its activity by AT, a catalase activity inhibitor before addition to cells, concomitantly lost its COX-2 inducing ability. Mechanistic analyses have further shown that the catalase-induced COX-2 expression in Raw cells is correlated with

Acknowledgements

We deeply thank Dr. H. Herschman (UCLA, CA) for providing us a luciferase DNA construct containing a murine COX-2 promoter. This work was supported by the Korea Science and Engineering Foundation (KOSEF) through the Chronic Disease Research Center at Keimyung University.

References (35)

  • G. Bleau et al.

    Measurement of hydrogen peroxide in biological samples containing high levels of ascorbic acid

    Anal. Biochem.

    (1998)
  • C.D. Putnam et al.

    Active and inhibited human catalase structures: ligand and NADPH binding and catalytic mechanism

    J. Mol. Biol.

    (2000)
  • A.G. Martin et al.

    Regulation of nuclear factor kappa B transactivation. Implication of phosphatidylinositol 3-kinase and protein kinase C zeta in c-Rel activation by tumor necrosis factor alpha

    J. Biol. Chem.

    (2001)
  • B. Vanhaesebroeck et al.

    Signaling by distinct classes of phosphoinositide 3-kinases

    Exp. Cell Res.

    (1999)
  • R.A. Brown et al.

    Insulin activates the alpha isoform of class II phosphoinositide 3-kinase

    J. Biol. Chem.

    (1999)
  • W.L. Smith et al.

    Cyclooxygenases: structural, cellular, and molecular biology

    Annu. Rev. Biochem.

    (2000)
  • K. Kobayashi et al.

    Arachidonic acid cascade and gastric mucosal injury, protection, and healing: topics of this decade

    J. Clin. Gastroenterol.

    (1995)
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