Conjugated Polyhydroxybenzene Derivatives Block Tumor Necrosis Factor-α–Mediated Nuclear Factor-κB Activation and Cyclooxygenase-2 Gene Transcription by Targeting IκB Kinase Activity
- 1Department of Pharmacology (C.-C.C., K.-T.C., S.-T.C.) and 2School of Pharmacy (J.-W.C.), College of Medicine, National Taiwan University, Taipei, Taiwan
- Dr. Ching-Chow Chen, Department of Pharmacology, College of Medicine, National Taiwan University, No.1, Jen-Ai Road, 1st Section, Taipei, 10018, Taiwan. E-mail:ccchen{at}ha.mc.ntu.edu.tw
Abstract
Because the transcription factor, nuclear factor (NF)-κB, plays a key role in cellular inflammatory and immune responses, components of the NF-κB–activating signaling pathways are frequently used as targets for anti-inflammatory agents. This study shows that 2-(3′4′-dihydroxyphenyl)-5-hydroxybenzo[b]furan (GF-015) and 2,3-di(3′4′-dihydroxy-transstyryl) pyridine (GF-90), two conjugated polyhydroxybenzene derivatives, inhibited a common step in NF-κB activation in human NCI-H292 epithelial cells by preventing tumor necrosis factor (TNF)-α– and 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced IκB kinase (IKK) complex activation. Both agents inhibited the TNF-α- or TPA-induced expression of cyclooxygenase (COX)-2 mRNA and protein, COX-2 promoter activity, and prostaglandin E2(PGE2) production. Overexpression of wild-type NF-κB–inducing kinase, IKKα, and IKKβ led, respectively, to 3.5-, 2.6-, and 2.6-fold increases in COX-2 promoter activity, and these effects were inhibited by both compounds. GF-015 and GF-90 also prevented the TNF-α- and TPA-induced activation of IKK and NF-κB–specific DNA-protein binding activity. These results suggest that the inhibitory effect of GF-015 and GF-90 on TNF-α–induced COX-2 protein expression was caused by suppression of IKK activity and NF-κB activation in the COX-2 promoter, resulting in attenuation of COX-2 gene expression and PGE2 production.
Footnotes
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This work was supported by a research grant from the National Science Council of Taiwan.
- Abbreviations:
- COX
- cyclooxygenase
- PG
- prostaglandin
- NF
- nuclear factor
- IκB
- inhibitory protein of nuclear factor-κB
- NIK
- nuclear factor-κB–inducing kinase
- IKK
- IκB kinase
- TNF
- tumor necrosis factor
- PKC
- protein kinase C
- GF-015
- 2-(3′4′-dihydroxyphenyl)-5-hydroxybenzo[b]furan
- GF-90
- 2,3-di(3′,4′-dihydroxy-transstyryl) pyridine
- FCS
- fetal calf serum
- ECL
- enhanced chemiluminescence
- SSC
- standard saline citrate
- TPA
- 12-O-tetradecanoylphorbol-13-acetate
- PAGE
- polyacrylamide gel electrophoresis
- TTBS
- 0.1% nonfat dry milk in Tris-buffered saline containing Tween 20
- PMSF
- phenylmethylsulfonyl fluoride
- DTT
- dithiothreitol
- GST
- glutathioneS-transferase
- MG132
- N-CBZ-Leu-Leu-Leu-al
- PBS
- phosphate-buffered saline
- NSAIDs
- nonsteroidal anti-inflammatory drugs
- NS-398
- N-(2-cyclohexyloxy-4-nitrophenyl)methane sulfonamide
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- Received March 20, 2001.
- Accepted August 21, 2001.
- The American Society for Pharmacology and Experimental Therapeutics
