We have purified a human non-pancreatic phospholipase A2 that is present in platelets and enriched rheumatoid synovial fluid.The enzyme calcium-dependent, has pH optimum of 8-10, shows striking preference for substrate presented the form Escherichia coli membranes.In E. assay exhibits an apparent specific activity 300 pmol/mg/min.Using oligonucleotide probes based on amino-terminal sequence data, we cloned corresponding gene from genomic DNA library expressed animal cells.The protein was...

Abstract Eicosanoids are key players in inflammatory diseases and cancer. Targeting their production by inhibiting Group IVA cytosolic phospholipase A 2 (cPLA α) offers a promising approach for cancer therapy. In this study, we synthesize second generation of thiazolyl ketone inhibitors cPLA α starting with compound GK470 (AVX235) test vitro cellular activities. We identify more potent selective lead molecule, GK420 (AVX420), which parallel AVX235 structurally unrelated compound, AVX002...

Secretory nonpancreatic type II phospholipase A 2 (snpPLA ) hydrolyzes fatty acids at the sn-2 position in phospholipids releasing free (FFAs) and lysophospholipids. These products may act as intracellular second messengers or can be further metabolized into proinflammatory lipid mediators. The presence of snpPLA extracellular fluids serum during inflammation has suggested a role enzyme this process. However, variety normal tissues suggests that also have physiological functions....

Excessive production of eicosanoids is characteristic many inflammatory diseases. In this study we show that ceramide, which an early messenger cytokine action, exerts a dual effect on the cytosolic phospholipase A2 (cPLA2), rate-limiting enzyme in arachidonic acid release and subsequent eicosanoid formation. Stimulation renal mesangial cells with exogenous short-chain ceramide analogs for 30 60 min leads to concentration-dependent increase not blocked by specific inhibitors...

Abstract TNF signaling mechanisms involved in activation of transcription factor NF-κB were studied the human keratinocyte cell line HaCaT. We show that TNF-induced was inhibited by well-known selective inhibitors cytosolic phospholipase A2 (cPLA2): trifluoromethyl ketone analogue arachidonic acid (AACOCF3) and methyl arachidonyl fluorophosphate. The eicosapentaenoic (EPACOCF3) also suppressed vitro cPLA2 enzyme activity with a similar potency as AACOCF3. (AACOCH3) eicosapentanoyl...

Phospholipase A2 acting on low density lipoproteins in the extracellular arterial intima may form proinflammatory lipid mediators. Human nonpancreatic secretory phospholipase has three regions that associate with sulfated glycosaminoglycans. The apoB-100 molecule also glycosaminoglycan binding could mediate its retention intima. Here we report human isolated from a transfected cell line binds to glycosaminoglycans secreted by cultured smooth muscle cells. A gel mobility shift assay showed...

Tumor necrosis factor (TNF)-α and interleukin (IL)-1β are potent activators of the transcription NF-κB, induced during inflammatory conditions. We have previously shown that both secretory cytosolic phospholipase A2(PLA2) involved in TNF-α- IL-1β-induced NF-κB activation. In this study, we addressed mechanism PLA2 involvement with respect to downstream arachidonic acid (AA) metabolites functional coupling between PLA2s mediating show addition inhibitors PLA2s, 5-lipoxygenase attenuate...

Abstract —Group IIA secretory nonpancreatic phospholipase A 2 (snpPLA ) is associated with collagen fibers in the extracellular matrix of human atherosclerotic plaques. Decorin, a small proteoglycan (PG) carrying chondroitin/dermatan sulfate glycosaminoglycans (GAGs), forms part network arteries. To explore whether snpPLA may be via interaction decorin, we performed (1) immunohistochemistry to compare relative vivo localization and decorin tissue (2) vitro experiments study between decorin....

Objective: The aim of this study was to determine the involvement pro-inflammatory phospholipase A2 (PLA2) enzymes in human chondrocytes from patients with osteoarthritis (OA).Methods: PLA2 OA analysed by (a) arachidonic acid (AA) and oleic release, (b) mRNA analysis, (c) prostaglandin E2 (PGE2) production cultured response various cytokines platelet activating factor (PAF).Results: Pro-inflammatory PAF stimulation led increased AA interleukin (IL)-1β tumour necrosis (TNF) being strongest...

Oxidized low-density lipoproteins (LDLs) play an important role during the development of atherosclerosis characterized by intimal inflammation and macrophage accumulation. A key component LDL is lysophosphatidylcholine (lysoPC). LysoPC a strong proinflammatory mediator, its mechanism uncertain, but it has been suggested to be mediated via platelet activating factor (PAF) receptor. Here, we report that PAF triggers pertussis toxin- (PTX-) sensitive intracellular signaling pathway leading...

IntroductionRheumatoid arthritis (RA) is an inflammatory disease of the joint characterized by chronic synovitis causing pain, swelling and loss function due to destruction cartilage bone. The complex series pathological events occurring in RA largely regulated via excessive production pro-inflammatory cytokines, most prominent being tumor necrosis factor (TNF). objective this work was elucidate possible involvement group IVA cytosolic phospholipase A2 (cPLA2α) TNF-induced regulation...

Group IVA cytosolic phospholipase A2 (GIVA cPLA2) is the rate-limiting provider of pro-inflammatory mediators in many tissues and thus an attractive target for development novel anti-inflammatory agents. In this work, we present synthesis new thiazolyl ketones study their activities vitro, cells, vivo. Within series compounds, methyl 2-(2-(4-octylphenoxy)acetyl)thiazole-4-carboxylate (GK470) was found to be most potent inhibitor GIVA cPLA2, exhibiting XI(50) value 0.011 mole fraction a mixed...

Group IVA cytosolic phospholipase A2 (cPLA2α) plays an important role in tumorigenesis and angiogenesis. It is overexpressed basal-like breast cancer (BLBC), which aggressive usually triple-negative, making it unresponsive to current targeted therapies. Here, we evaluated the anti-angiogenic effects of a specific cPLA2α inhibitor, AVX235, patient-derived triple-negative BLBC model. Mice bearing orthotopic xenografts received i.p. injections AVX235 or DMSO vehicle daily for 1 week then every...

As a regulator of cellular inflammation and proliferation, cytosolic phospholipase A2 α (cPLA2α) is promising therapeutic target for psoriasis; indeed, the cPLA2α inhibitor AVX001 has shown efficacy against plaque psoriasis in phase I/IIa clinical trial. To improve our understanding anti-psoriatic properties AVX001, we sought to determine how compound modulates keratinocyte hyperproliferation, key characteristics psoriatic epidermis. We measured eicosanoid release from human peripheral blood...

Abstract Background Cytosolic phospholipase A2 ( cPLA 2α) is an enzyme suggested as a therapeutic target in inflammatory skin diseases. AVX 001, 2α inhibitor, was investigated randomized, double‐blind, placebo‐controlled, split‐design, first‐in‐man study patients with mild to moderate psoriasis. Objectives The primary objective evaluate cutaneous safety and tolerability of 001 doses from 0.002% 5.0%. Safety assessed local reaction adverse events LSRAE ) grades 3‐4. secondary assessment...

Abstract —Phospholipase A 2 s (PLA s) constitute a family of enzymes that hydrolyze fatty acids membrane phospholipids, thus initiating the synthesis proinflammatory mediators. Various PLA have been detected in human atherosclerotic arteries (advanced lesions); however, only secretory group has shown to specifically low density lipoprotein (LDL)–associated phospholipids and, as such, may play potential role atherogenesis. In present study, we investigated expression pattern IIa, IV, and V...

Background and Purpose ω3‐polyunsaturated fatty acids (ω3‐ PUFAs ) are known to exert anti‐inflammatory effects in various disease models although their direct targets only poorly characterized. Experimental approach Here we report on two new c PLA 2 inhibitors, the ω3‐derivatives AVX 001 002, inflammatory PGE production cultures of renal mesangial cells. Key Results 002 dose‐dependently inhibited group IVA cytosolic phospholipase A (c an vitro activity assay with similar IC 50 values for...

Rheumatoid arthritis (RA) is an autoimmune disease characterized by chronic synovitis leading to destruction of cartilage and bone. PLA2 enzymes are key players in inflammation regulating the release unsaturated fatty acids such as arachidonic acid (AA), a precursor pro-inflammatory eicosanoids. Several lines evidence point toll-like receptors (TLRs) drivers joint RA. However, few studies have addressed implication activity downstream TLR activation synovium. Here, we aimed characterize...

The transcription factor nuclear κB (NF-κB) plays crucial roles in a wide variety of biological functions such as inflammation, stress, and immune responses. We have shown previously that secretory nonpancreatic (snp) cytosolic (c) phospholipase A₂ (PLA₂) regulate NF-κB activation response to tumor necrosis (TNF)-α or interleukin (IL)-1β functional coupling mediated by the 5-lipoxygenase (5-LO) metabolite leukotriene B₄ (LTB₄) exists between...