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Title: Induction of cyclooxygenase-2 by heat shock protein 60 in macrophages and endothelial cells.

Authors: Billack, Blase; Heck, Diane E; Mariano, Thomas M; Gardner, Carol R; Sur, Runa; Laskin, Debra L; Laskin, Jeffrey D

Published In Am J Physiol Cell Physiol, (2002 Oct)

Abstract: The 60-kDa heat shock protein (HSP60), an endogenous ligand for the toll-like 4 receptor, is generated in response to inflammation, tissue injury, and/or stress and stimulates macrophages to produce cytotoxic and proinflammatory mediators including nitric oxide, tumor necrosis factor (TNF)-alpha, interleukin (IL)-6, and IL-12. In the present studies we report that HSP60 is an effective inducer of cyclooxygenase-2 (COX-2) in macrophages, as well as endothelial cells. In both cell types, the synthesis of COX-2 was coordinate with induction of nitric oxide synthase (NOS)-2 and with nitric oxide production. With the use of promoter constructs in transient transfection assays, optimal expression of COX-2 in macrophages was found to require nuclear factor (NF)-kappaB, the cAMP-response element (CRE), and NF-IL-6, but not the E-box. Mobility shift assays revealed that HSP60 induced NF-kappaB and CRE binding activity, while CCAAT/enhancer binding protein (C/EBP), which binds to NF-IL-6, was constitutively active in the cells. Both c-Jun and CRE binding protein (CREB) bound to the CRE, while C/EBP-beta bound to NF-IL-6. These data indicate that NF-kappaB, C/EBP-beta, c-Jun, and CREB are important in HSP60-induced expression of COX-2. The c-Jun-NH(2)-terminal kinase (JNK), p44/42 mitogen-activated protein (MAP) kinase [extracellular signal-regulated kinase 1/2 (ERK1/2)], and p38 MAP kinase were rapidly activated by HSP60 in the macrophages. PD-98059, an inhibitor of phosphorylation of ERK1/2, caused a marked inhibition of HSP60-induced COX-2 and NOS-2 expression. Unexpectedly, SB-203580, a p38 kinase antagonist, was found to block HSP60-induced expression of COX-2, but not NOS-2. These data indicate that both ERK1/2 kinase and p38 kinase play a role in regulating HSP60-induced expression of COX-2.

PubMed ID: 12225989 Exiting the NIEHS site

MeSH Terms: Animals; CCAAT-Enhancer-Binding Proteins/metabolism; Cells, Cultured; Chaperonin 60/pharmacology*; Cyclic AMP Response Element-Binding Protein/metabolism; Cyclooxygenase 2; Endothelium/cytology; Endothelium/drug effects; Endothelium/enzymology*; Enzyme Induction/drug effects*; Enzyme Inhibitors/pharmacology; Gene Expression Regulation/drug effects*; Genes, Reporter; Interferon-gamma/pharmacology; Isoenzymes/antagonists & inhibitors; Isoenzymes/genetics; Isoenzymes/metabolism*; Lipopolysaccharides/pharmacology; Macrophages/cytology; Macrophages/drug effects; Macrophages/enzymology*; Mice; Mitogen-Activated Protein Kinases/metabolism; Mutagenesis, Site-Directed; Nitric Oxide Synthase Type II; Nitric Oxide Synthase/genetics; Nitric Oxide Synthase/metabolism; Nitric Oxide/biosynthesis; Promoter Regions, Genetic; Prostaglandin-Endoperoxide Synthases/genetics; Prostaglandin-Endoperoxide Synthases/metabolism*; RNA, Messenger/biosynthesis; Rats; Regulatory Sequences, Nucleic Acid/physiology; Transcription Factors/metabolism; Transfection

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