Phospholipase A<sub>2</sub> and arthritis

Bomalaski, John S.; Clark, Mike A.

doi:10.1002/art.1780360208

Cited by 79 publications

(38 citation statements)

References 81 publications

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“…In RA, production of IL-1␤ and TNF␣ is increased in the inflamed synovial tissue, and these cytokines enhance cPLA2 secretion from fibroblasts, chondrocytes, and other cells in the synovium with increasing level of cPLA2 in the joint fluid (22,32,33). On the other hand, IL-1␤ and TNF␣ also induce COX-2 production in macrophages, fibroblasts, and synovial lining cells.…”

Section: Discussionmentioning

confidence: 99%

Intraarticular Osteoid Osteoma Associated with Synovitis: A Possible Role of Cyclooxygenase-2 Expression by Osteoblasts in the Nidus

Kawaguchi

Sato

Hasegawa³

et al. 2000

Modern Pathology

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To clarify the condition of development of synovitis associated with intraarticular osteoid osteoma (OO), expressions of cyclooxygenase-2 (COX-2) protein and its messenger ribonucleic acid were investigated both in the nidus and the synovial tissue using immunohistochemical and reverse transcription-polymerase chain reaction analyses. Diffuse and strong COX-2 immunoreactivity was found in osteoblast-like tumor cells in the nidus of all six cases of OO (three of six cases were intraarticular OO associated with synovitis) and one case of osteoblastoma associated with synovitis. Expression of COX-2 messenger ribonucleic acid was demonstrated in one case of OO associated with synovitis, and was higher in the nidus than that in the inflamed synovial tissue. However, there were no significant difference between the nidus and synovium in the expression of cytosolic phospholipase A2, one of the enzymes involved in arachidonic acid metabolism, and inflammatory cytokines such as interleukin-1␤ and tumor necrosis factor alpha. Finally, as there was only one case in which the examinations of gene expression were performed, no definitive overall conclusions could be reached; rather it is suggested that COX-2 expressed primarily by osteoblasts in the nidus of intraarticular OO may play a role in activating the pathway of arachidonic acid metabolism, resulting in synovitis of the involved joint.

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Section: Discussionmentioning

confidence: 99%

Intraarticular Osteoid Osteoma Associated with Synovitis: A Possible Role of Cyclooxygenase-2 Expression by Osteoblasts in the Nidus

Kawaguchi

Sato

Hasegawa³

et al. 2000

Modern Pathology

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“…PLA2 enzymes may be involved in cell proliferation and signal transduction as well as in the pathogenesis of disease processes such as inflammation (Mukherjee et al, 1994). Secretory PLA2s with the biochemical properties of group II enzymes can be induced and secreted from cytokine-stimulated cells (Daniels et al, 1992;Glaser et al, 1993;Angel et al, 1993), and they are present at high levels in synovial fluid, peripheral blood, neutrophils and monocytes of patients with rheumatoid arthritis (Kramer et al, 1989;Bomalaski & Clark, 1993). In this experimental model the synthesis and secretion of PLA2 can be induced by TNFa, for this cytokine enhances the expression of group II PLA2 and may also facilitate membrane phospholipid hydrolysis by this enzyme (Kudo et al, 1993).…”

Section: Discussionmentioning

confidence: 99%

“…**P<0.01. Kudo et al, 1993;Weiss et al, 1994), or participation in a proliferative response and regulation of cytokine synthesis (Bomalaski & Clark, 1993). The marine natural product scalaradial inhibits in vitro recombinant human synovial and bee venom PLA2 in an irreversible way (de Carvalho & Jacobs, 1991;Marshall et al, 1994), whereas it shows a lower potency on cytosolic PLA2 preparations .…”

Section: Discussionmentioning

confidence: 99%

Involvement of secretory phospholipase A₂ activity in the zymosan rat air pouch model of inflammation

Payá

Terencio

Ferrándiz

et al. 1996

British J Pharmacology

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1 In the zymosan rat air pouch model of inflammation we have assessed the time dependence of phospholipase A2 (PLA2) accumulation in the inflammatory exudates as well as cell migration, myeloperoxidase activity, prostaglandin E2 (PGE2) and leukotriene B4 (LTB4) levels. 2 A significant increase in PLA2 activity was detected in 1,200 g supernatants of exudates 8 h after injection of zymosan into rat air pouch. This event coincided with peaks in cell accumulation (mainly neutrophils) and myeloperoxidase activity in exudates and was preceded by a rise in eicosanoid levels. 3 This enzyme (without further purification) behaved as a secretory type II PLA2 with an optimum pH at 7-8 units, lack of selectivity for arachidonate release and dependence on mM calcium concentrations for maximal activity. 4 The PLA2 inhibitors manoalide and scalaradial inhibited this enzyme activity in vitro in a concentration-dependent manner. Scalaradial also inhibited zymosan stimulated myeloperoxidase release in vitro.5 Injection of the marine PLA2 inhibitor scalaradial together with zymosan into the pouch at doses of 0.5, 1 and 5 umol per pouch resulted in a dose-dependent inhibition of PLA2 activity in exudates collected 8 h later. Myeloperoxidase levels and cell migration were also decreased, while eicosanoid levels were not modified. 6 Colchicine administration to rats prevented infiltration and decreased PLA2 levels in the 8 h zymosan-injected air pouch. 7 These results indicate that during inflammatory response to zymosan in the rat air pouch a secretory PLA2 activity is released into the exudates. The source of this activity is mainly the neutrophil which migrates into the pouch. 8 Scalaradial exerts anti-inflammatory effects in the zymosan air pouch.

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“…Phospholipase A2 has a pivotal role in the generation of lipid mediators and when induced and released by cytokines or growth factors (Gilman & Chang, 1990;Oka & Arita, 1991;Spaargaren et al, 1992), the soluble form is thought to mediate 1 Author for correspondence. inflammation in a variety of diseases (Bomalaski et al, 1991;Bomalaski & Clark, 1993). We have shown that the extracellular 14 kDa PLA2 does not play a role in macrophage PGE2 biosynthesis and proposed that a cell-associated 85 kDa PLA2 may regulate this process .…”

Section: Introductionmentioning

confidence: 79%

Prostaglandin E₂ requirement for transforming growth factor β₂ inhibition of elicited macrophage 14 kDa phospholipase A₂ release

McCord

Bolognese

Marshall

1995

British J Pharmacology

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1 Cultured elicited-peritoneal macrophages release a soluble type 11 14 kDa phospholipase A2 (PLA2) over time, reaching a plateau by 20-24 h of incubation and maintaining these levels over 72 h. Prostaglandin E2 (PGE2) is also produced but does not plateau until 48-72 h. 2 Transforming growth factor fI (TGFfB) reduces cellular 14 kDa PLA2 and its subsequent release by approximately half, but does not alter PGE2 production. Co-incubation of TGF#l with indomethacin interfered, in a concentration-dependent manner, with the ability of TGF#f to reduce cellular 14 kDa PLA2 and its subsequent release over 24 h. The regulation of TGFfj was not specific to indomethacin since other non-steroidal anti-inflammatory drugs had the same effect. This suggested that cyclooxygenase activity was essential for TGF#l to exert its effect and indeed, the addition of exogenous PGE2 restored the TGF#f action.3 PGE2 alone exerted a concentration-dependent negative feedback action on elicited-macrophage 14 kDa PLA2 release. The inhibitory concentration (IC50 = 180 ng PGE2 ml-') approximated the PGE2 levels measured in the 24 h macrophage conditioned media (85-140 ng PGE2 ml-') where PLA2 release began to plateau. Further, incubation of cells with indomethacin over 48 h resulted in the enhancement of 14 kDa PLA2 activity compared to that released from untreated cells. Forskolin failed to inhibit 14 kDa PLA2 release, suggesting PGE2 was not acting through an increase in adenylate cyclase. 4 Taken together, the data are consistent with the immunosuppressive aspects reported for both mediators during inflammation and demonstrates the requirement of PGE2 for TGF/3 action on the elicited macrophage.

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Phospholipase A₂ and arthritis

Cited by 79 publications

References 81 publications

Intraarticular Osteoid Osteoma Associated with Synovitis: A Possible Role of Cyclooxygenase-2 Expression by Osteoblasts in the Nidus

Intraarticular Osteoid Osteoma Associated with Synovitis: A Possible Role of Cyclooxygenase-2 Expression by Osteoblasts in the Nidus

Involvement of secretory phospholipase A₂ activity in the zymosan rat air pouch model of inflammation

Prostaglandin E₂ requirement for transforming growth factor β₂ inhibition of elicited macrophage 14 kDa phospholipase A₂ release

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Phospholipase A2 and arthritis

Cited by 79 publications

References 81 publications

Intraarticular Osteoid Osteoma Associated with Synovitis: A Possible Role of Cyclooxygenase-2 Expression by Osteoblasts in the Nidus

Intraarticular Osteoid Osteoma Associated with Synovitis: A Possible Role of Cyclooxygenase-2 Expression by Osteoblasts in the Nidus

Involvement of secretory phospholipase A2 activity in the zymosan rat air pouch model of inflammation

Prostaglandin E2 requirement for transforming growth factor β2 inhibition of elicited macrophage 14 kDa phospholipase A2 release

Contact Info

Product

Resources

About

Phospholipase A₂ and arthritis

Involvement of secretory phospholipase A₂ activity in the zymosan rat air pouch model of inflammation

Prostaglandin E₂ requirement for transforming growth factor β₂ inhibition of elicited macrophage 14 kDa phospholipase A₂ release