Abstract
Nonsteroidal anti-inflammatory drugs (NSAIDs) have been reported to induce apoptosis in a variety of cell lines. In this study, we examined the effect of NSAIDs on the growth and apoptosis of synovial cells from patients with rheumatoid arthritis and analyzed the activation of peroxisome proliferator-activated receptor γ (PPARγ) as a possible mechanism of action of NSAIDs. Cell proliferation and viability were assessed from 5-bromo-2′-deoxyuridine incorporation and by 4-[3-(4-iodophenyl)-2-(4-nitrophenyl)-2H-5-tetrazolio]-1,3-benzene disulfonate (WST-1) assay, respectively. The apoptosis of synovial cells was identified by DNA fragmentation assay and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assay. Indometacin, diclofenac, oxaprozin, and zaltoprofen reduced cell proliferation and induced apoptotic cell death in synovial cells, whereas ketoprofen and acetaminophen did not.N-[2-(cyclohexyloxyl)-4-nitrophenyl]-methanesulfonamide (NS-398), a selective cyclooxygenase-2 inhibitor, also inhibited cell proliferation, whereas it did not cause apoptosis. Rheumatoid synovial cells expressed PPARγ mRNA, and the PPARγ ligands 15-deoxy-Δ12,14-prostaglandin J2 and troglitazone reduced the proliferation and induced apoptosis in synovial cells. Luciferase reporter assay demonstrated that not only PPARγ ligands but also NSAIDs, which could induce apoptosis, increased the activation of PPARγ in synovial cells. Furthermore, the ability of NSAIDs and PPARγ ligands to stimulate the activation of PPARγ correlated with their ability to decrease cell viability(r = 0.92, p < 0.01) and ability to induce DNA fragmentation (r = 0.97, p < 0.001) in synovial cells. These results suggest that PPARγ is an attractive target for induction of apoptosis in rheumatoid synovial cells and that the activation of the PPARγ pathway is associated with the apoptotic action of NSAIDs.
Footnotes
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This work was supported in part by grants from Ministry of Education, Culture, Sports, Science and Technology of the Japanese Government. R.Y. is a guest researcher of St. Marianna University and belongs to Yakult Central Institute for Microbiological Research.
- Abbreviations:
- NSAID
- nonsteroidal anti-inflammatory drug
- COX
- cyclooxygenase
- PG
- prostaglandin
- PPARγ
- peroxisome proliferator-activated receptor γ
- 15dPGJ2
- 15-deoxy-Δ12,14-PGJ2
- TPA
- 12-O-tetradecanoylphorbol 13-acetate
- FBS
- fetal bovine serum
- IL-1β
- interleukin-1β
- BrdU
- 5-bromo-2′-deoxyuridine
- ELISA
- enzyme-linked immunosorbent assay
- WST-1
- 4-[3-(4-iodophenyl)-2-(4-nitrophenyl)-2H-5-tetrazolio]-1,3-benzene disulfonate
- TUNEL
- terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling
- RT-PCR
- reverse transcription-polymerase chain reaction
- PCR
- polymerase chain reaction
- bp
- base pair(s)
- PPRE
- peroxisome proliferator response element
- NS-398
- N-[2-(cyclohexyloxyl)-4-nitrophenyl]-methanesulfonamide
- Received January 25, 2002.
- Accepted March 15, 2002.
- The American Society for Pharmacology and Experimental Therapeutics
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