Induction of cyclooxygenase-2 by bovine type I collagen in macrophages via C/EBP and CREB activation by multiple cell signaling pathways

• Published in: Biochemical pharmacology 2004-06, Vol.67 (12), p.2239-2250
• Main Authors: Cho, Min Kyung, Cho, Yang Hee, Lee, Gum Hwa, Kim, Sang Geon
• Format: Article
• Language: English
• Subjects: Animals; Biological and medical sciences; C/EBP; Cattle; CCAAT-Enhancer-Binding Proteins - metabolism; Collagen Type I - pharmacology; COX-2; CREB; Cyclic AMP Response Element-Binding Protein - metabolism; Cyclooxygenase 2; Enzyme Induction - drug effects; ERK1/2; FAK; Isoenzymes - biosynthesis; Macrophages - drug effects; Macrophages - metabolism; Medical sciences; Mice; Mitogen-Activated Protein Kinases - metabolism; NF-kappa B - metabolism; p38-kinase; Pharmacology. Drug treatments; Phosphatidylinositol 3-Kinases - metabolism; PI3-kinase; Prostaglandin-Endoperoxide Synthases - biosynthesis; Signal Transduction - drug effects; Type I collagen
• ISSN: 0006-2952; 1873-2968
• DOI: 10.1016/j.bcp.2004.02.024

Bovine type I collagen (Col-I) is utilized for medical purposes such as cosmetic surgery and wrinkle removal. Cyclooxygenase-2 (COX-2) plays roles in pathophysiological processes including inflammation and tumorigenesis. This study examines the effects of Col-I on the COX-2 expression and the signaling pathways in macrophages. Col-I increased the levels of COX-2 protein and mRNA in serum-stimulated Raw264.7 cells in a time- and concentration-dependent manner. Treatment of cells with Col-I increased CCAAT/enhancer binding protein (C/EBP) DNA binding. Antibody supershift experiments revealed that C/EBP DNA binding activity induced by Col-I depended largely on C/EBPβ and C/EBPδ. Immunocytochemistry showed that Col-I induced nuclear translocation of C/EBPβ and C/EBPδ, whose activation contributes to COX-2 induction. Overexpression of the dominant-negative mutant form of C/EBP abolished COX-2 induction by Col-I. Col-I also increased cyclic-AMP response element binding protein (CREB) binding to DNA. Inhibition of focal adhesion kinase (FAK) or downstream phosphoinositide 3-kinase and p70S6 kinase by specific chemical inhibitors prevented COX-2 induction by Col-I, and C/EBP and CREB from binding to their consensus DNA oligonucleotides. Experiments using chemical inhibitors or dominant-negative mutant vectors showed that the mitogen-activated protein (MAP) kinase pathways including p38-kinase and extracellular signal-regulated kinase (ERK1/2), but not c-Jun N-terminal kinase (JNK1), simultaneously regulated COX-2 induction by Col-I. This was in agreement with inhibition of Col-I-inducible C/EBP and CREB DNA binding by concomitant treatment with SB203580 and PD98059. These results provide evidence that Col-I induces COX-2 in serum-stimulated macrophages and that the multiple cell signaling pathways involving Src-focal adhesion kinase, phosphoinositide 3-kinase, and MAP kinases regulate COX-2 induction by Col-I via C/EBP and CREB activation.