Non-steroidal Anti-inflammatory Drugs Inhibit Nitric Oxide-induced Apoptosis and Dedifferentiation of Articular Chondrocytes Independent of Cyclooxygenase Activity

Abstract

Nitric oxide (NO) causes apoptosis and dedifferentiation of articular chondrocytes by the modulation of extracellular signal-regulated kinase (ERK), p38 kinase, and protein kinase C (PKC) ␣ and -. In this study, we investigated the effects and mechanisms of non-steroidal anti-inflammatory drugs (NSAIDs), such as indomethacin, ketoprofen, ibuprofen, sulindac sulfide, and flurbiprofen, in NO-induced apoptosis and dedifferentiation of articular chondrocytes. We found that all of the examined NSAIDs inhibited apoptosis and dedifferentiation. NO production in chondrocytes caused activation of ERK-1/2 and p38 kinase, which oppositely regulate apoptosis and dedifferentiation. NO production also caused inhibition of PKC␣ and -independent of and dependent on, respectively, p38 kinase, which is required for apoptosis and dedifferentiation. Among the signaling molecules modulated by NO, NSAIDs blocked NO-induced activation of p38 kinase, potentiated ERK activation, and blocked inhibition of PKC␣ and -. NSAIDs also inhibited some of the apoptotic signaling that is downstream of p38 kinase and PKC, such as NFB activation, p53 accumulation, and caspase-3 activation. The inhibitory effects of NSAIDs on apoptosis and dedifferentiation were independent of the inhibition of cyclooxygenase (COX)-2 and prostaglandin E 2 (PGE 2 ) production, as evidenced by the observation that specific inhibition of COX-2 activity and PGE 2 production or exogenous PGE 2 did not affect NO-induced apoptosis and dedifferentiation. Taken together, our results indicate that NSAIDs block NO-induced apoptosis and dedifferentiation of articular chondrocytes by the modulation of ERK, p38 kinase, and PKC␣ and -in a manner independent of their ability to inhibit COX-2 and PGE 2 production.Chondrocytes are a unique cell type in which the differentiated phenotype is reversible. The phenotype of chondrocytes is regulated by the balance between anabolic and catabolic reactions of molecules, which are involved in the maintenance of cartilage homeostasis (1). Differentiated chondrocytes both in vivo and in vitro dedifferentiate into fibroblastic cells upon exposure to interleukin-1␤ (2, 3), retinoic acid (4), or nitric oxide (NO) 1 (5). Although the molecular mechanism is not yet clear, dedifferentiation of articular chondrocytes is believed to play a role in the pathophysiology of arthritis. In addition to dedifferentiation, increased apoptotic death of chondrocytes was observed in arthritic cartilage, and apoptosis is closely related to cartilage destruction (6, 7), indicating that chondrocyte apoptosis plays an important role in the pathogenesis of arthritis.NO is generally believed to be an important mediator of the dedifferentiation and apoptosis of articular chondrocytes in arthritic cartilage (5,8,9). NO is produced in chondrocytes by the action of proinflammatory cytokines, such as interleukin-1␤. NO production in chondrocytes causes activation of matrix metalloproteinases (10), decreased production of interleukin-1 receptor antagonists (11), inhibition of ...

Comparison of the COX‐inhibiting nitric oxide donator AZD3582 and rofecoxib in treating the signs and symptoms of Osteoarthritis of the knee

“…The reason for the slightly higher incidence in the AZD3582 375 mg and 750 mg twice a day groups than in the naproxen recipients is not known. Although inducible nitric oxide may alter cartilage metabolism by a number of possible mechanisms (29), the effects of exogenous nitric oxide or nitric oxide in the presence of NSAIDs (30) are not known; no evaluation of cartilage integrity was undertaken in this study.…”

p38 kinase mediates nitric oxide-induced apoptosis of chondrocytes through the inhibition of protein kinase C ζ by blocking autophosphorylation

“…The data in (a-c) represent mean and standard deviation, and in (d) and (e) represent a typical result from at least four independent experiments p38 kinase regulation of PKCf during apoptosis J-S Kim et al with NO-induced apoptosis requiring downregulation of PKCz. [15][16][17][18][19] The chondrocyte pro-and antiapoptotic functions of p38 kinase and PKCz, respectively, are also observed in other cell types. [21][22][23][24] Evidence that PKCz provides survival signals in chondrocytes is supported by the observations that ectopic expression of wild-type or constitutively active PKCz inhibited NO-induced apoptosis of articular chondrocytes, whereas inhibition of PKCz activity by PS-PKCz potentiated NO-induced apoptosis.…”

“…Chondrocytes from day 3 cultures were infected with either control adenovirus or adenovirus containing wild-type mouse PKCz cDNA, as previously described, 18 and infected cells were cultured in complete medium for 24 h. In some experiments, infected cells were treated with 1 mM SNP for an additional 12 h. Alternatively, chondrocytes were transfected with plasmids coding for wild-type p38 kinase, myc-tagged PKCz wild-type, regulatory domain, catalytic domain, or mutants (S113A, S186A, T560A, and S113A/S186A) using LipofectAMINE PLUS (Invitrogen, Carlsbad, CA, USA) as previously described. 19,33 The cells were cultured in complete medium for 24 h prior to further use.…”

“…13,14 PKCz functions as a survival signal during NO-induced apoptosis of articular chondrocytes since NO-induced chondrocyte apoptosis requires inhibition of PKCz. [15][16][17][18][19] The PKCz inhibition occurs as a result of NOinduced p38 kinase activation and the inhibition of PKCz activity is followed by proteolytic cleavage via the caspase-3-dependent pathway. 15 Our previous observation 15 that inhibition of caspase-3 did not rescue the inhibition of PKCz activity although cleavage of PKCz was significantly abrogated clearly indicated that inhibition of PKCz activity precedes its cleavage by caspase-3.…”

Gallotannin regulates apoptosis and COX-2 expression via Akt and p38kinase pathway in human lung cancer cell line, A549

“…GT additionally induced apoptotic cell death, as determined by DNA fragmentation ( Figure 1B). Because sodium nitroprusside (SNP), a nitric oxide donor, has been known as an inducer of apoptosis in various cell lines, we used as a positive control for DNA fragmentation in our data (Yoon et al 2003) ( Figure 1B). GT increased the ratio of apoptosis at 100 mM GT ( Figure 1B).…”