TY - JOUR
T1 - Activation of NFκB is necessary for IL-1β-induced cyclooxygenase-2 (COX-2) expression in human gingival fibroblasts
AU - Nakao, Sumi
AU - Ogata, Yorimasa
AU - Shimizu-Sasaki, Emi
AU - Yamazaki, Muneyoshi
AU - Furuyama, Shunsuke
AU - Sugiya, Hiroshi
PY - 2000
Y1 - 2000
N2 - The immediate-early cyclooxygenase-2 (COX-2) gene encodes an inducible prostaglandin synthase enzyme which is implicated in inflammatory and proliferative diseases. COX-2 is highly induced during cell activation by various factors, including mitogens, hormones and cytokines. Since pro- inflammatory cytokine IL-1β has been shown to induce prostaglandin E2 (PGE2) release in human gingival fibroblasts (HGF), here we analyzed the effect of IL-1β on the expression of COX-2 and the activation of NFκB in HGF. Northern hybridization analysis revealed that IL-1β (200 pg/ml) increased the expression of COX-2 mRNA in HGF. The effect of IL-1β was abrogated by herbimycin A, a protein tyrosine kinase inhibitor, and enhanced by orthovanadate, a protein tyrosine phosphatase inhibitor. IL-1β-induced PGE2 release was blocked by the tyrosine kinase inhibitor and increased by the tyrosine phosphatase inhibitor. The results of transient transfection assays using chimeric constructs of the human COX-2 promoter (nt-1432~+59) ligated to a luciferase reporter gene indicated that IL-1β stimulated the transcriptional activity~1.5-fold. Gel mobility shift assays with a radiolabelled COX-2-NFκB oligonucleotide (nts-223 to -214) revealed an increase in the binding of nuclear proteins from IL-1β-stimulated HGF. This increase of DNA-protein complex formation induced by IL-1β was blocked by herbimycin A and another tyrosine kinase inhibitor, genistein. These results suggest that NFκB is an important transcription factor for IL-1β-induced COX-2 gene expression, and is involved in inducing COX-2 gene transcription through tyrosine phosphorylation in HGF.
AB - The immediate-early cyclooxygenase-2 (COX-2) gene encodes an inducible prostaglandin synthase enzyme which is implicated in inflammatory and proliferative diseases. COX-2 is highly induced during cell activation by various factors, including mitogens, hormones and cytokines. Since pro- inflammatory cytokine IL-1β has been shown to induce prostaglandin E2 (PGE2) release in human gingival fibroblasts (HGF), here we analyzed the effect of IL-1β on the expression of COX-2 and the activation of NFκB in HGF. Northern hybridization analysis revealed that IL-1β (200 pg/ml) increased the expression of COX-2 mRNA in HGF. The effect of IL-1β was abrogated by herbimycin A, a protein tyrosine kinase inhibitor, and enhanced by orthovanadate, a protein tyrosine phosphatase inhibitor. IL-1β-induced PGE2 release was blocked by the tyrosine kinase inhibitor and increased by the tyrosine phosphatase inhibitor. The results of transient transfection assays using chimeric constructs of the human COX-2 promoter (nt-1432~+59) ligated to a luciferase reporter gene indicated that IL-1β stimulated the transcriptional activity~1.5-fold. Gel mobility shift assays with a radiolabelled COX-2-NFκB oligonucleotide (nts-223 to -214) revealed an increase in the binding of nuclear proteins from IL-1β-stimulated HGF. This increase of DNA-protein complex formation induced by IL-1β was blocked by herbimycin A and another tyrosine kinase inhibitor, genistein. These results suggest that NFκB is an important transcription factor for IL-1β-induced COX-2 gene expression, and is involved in inducing COX-2 gene transcription through tyrosine phosphorylation in HGF.
KW - COX-2
KW - Gene regulation
KW - Human gingival fibroblasts
KW - IL-1β
KW - NFκB
KW - Tyrosine phosphorylation
UR - http://www.scopus.com/inward/record.url?scp=0033624495&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0033624495&partnerID=8YFLogxK
U2 - 10.1023/a:1007155525020
DO - 10.1023/a:1007155525020
M3 - Article
C2 - 10942208
AN - SCOPUS:0033624495
SN - 0300-8177
VL - 209
SP - 113
EP - 118
JO - Molecular and Cellular Biochemistry
JF - Molecular and Cellular Biochemistry
IS - 1-2
ER -