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RationaleIndirect airway hyperresponsiveness (AHR) is a fundamental feature of asthma that is manifest as exercise-induced bronchoconstriction (EIB). Secreted phospholipase A2 group X (sPLA2-X) plays a key role in regulating eicosanoid formation and the development of inflammation and AHR in murine models.ObjectivesWe sought to examine sPLA2-X in the airway epithelium and airway wall of patients with asthma, the relationship to AHR in humans, and the regulation and function of sPLA2-X within the epithelium.MethodsWe precisely phenotyped 34 patients with asthma (19 with and 15 without EIB) and 10 normal control subjects to examine in vivo differences in epithelial gene expression, quantitative morphometry of endobronchial biopsies, and levels of secreted protein. The regulation of sPLA2-X gene (PLA2G10) expression was examined in primary airway epithelial cell cultures. The function of epithelial sPLA2-X in eicosanoid formation was examined using PLA2 inhibitors and murine tracheal epithelial cells with Pla2g10 deletion.Measurements and main resultsWe found that sPLA2-X protein is increased in the airways of patients with asthma and that epithelial-derived sPLA2-X may be increased in association with indirect AHR. The expression of sPLA2-X increases during in vitro epithelial differentiation; is regulated by inflammatory signals including tumor necrosis factor, IL-13, and IL-17; and is both secreted from the epithelium and directly participates in the release of arachidonic acid by epithelial cells.ConclusionsThese data reveal a relationship between epithelial-derived sPLA2-X and indirect AHR in asthma and that sPLA2-X serves as an epithelial regulator of inflammatory eicosanoid formation. Therapies targeting epithelial sPLA2-X may be useful in asthma.

Objectives: This study sought to investigate the role of secretory phospholipase A2 (sPLA2)-IIA in cardiovascular disease.Background: Higher circulating levels of sPLA2-IIA mass or sPLA2 enzyme activity have been associated with increased risk of cardiovascular events. However, it is not clear if this association is causal. A recent phase III clinical trial of an sPLA2 inhibitor (varespladib) was stopped prematurely for lack of efficacy.Methods: We conducted a Mendelian randomization meta-analysis of 19 general population studies (8,021 incident, 7,513 prevalent major vascular events [MVE] in 74,683 individuals) and 10 acute coronary syndrome (ACS) cohorts (2,520 recurrent MVE in 18,355 individuals) using rs11573156, a variant in PLA2G2A encoding the sPLA2-IIA isoenzyme, as an instrumental variable.Results: PLA2G2A rs11573156 C allele associated with lower circulating sPLA2-IIA mass (38% to 44%) and sPLA2 enzyme activity (3% to 23%) per C allele. The odds ratio (OR) for MVE per rs11573156 C allele was 1.02 (95% confidence interval [CI]: 0.98 to 1.06) in general populations and 0.96 (95% CI: 0.90 to 1.03) in ACS cohorts. In the general population studies, the OR derived from the genetic instrumental variable analysis for MVE for a 1-log unit lower sPLA2-IIA mass was 1.04 (95% CI: 0.96 to 1.13), and differed from the non-genetic observational estimate (OR: 0.69; 95% CI: 0.61 to 0.79). In the ACS cohorts, both the genetic instrumental variable and observational ORs showed a null association with MVE. Instrumental variable analysis failed to show associations between sPLA2 enzyme activity and MVE.Conclusions: Reducing sPLA2-IIA mass is unlikely to be a useful therapeutic goal for preventing cardiovascular events. [ABSTRACT FROM AUTHOR]

Background: Gastroesophageal reflux and Barrett's esophagus are significant risk factors for the development of esophageal adenocarcinoma. Group IIa secretory phospholipase A 2 (sPLA 2 ) catalyzes the production of various proinflammatory metabolites and plays a critical role in promoting reflux-induced inflammatory changes within the distal esophagus. We hypothesized that inhibition of sPLA 2 in human Barrett's cells would attenuate adhesion molecule expression via decreased activation of nuclear factor kappa B (NF-κB) and decrease cell proliferation, possibly mitigating the invasive potential of Barrett's esophagus., Materials and Methods: Normal human esophageal epithelial cells (HET1A) and Barrett's cells (CPB) were assayed for baseline sPLA 2 expression. CPB cells were treated with a specific inhibitor of sPLA 2 followed by tumor necrosis factor-α. Protein expression was evaluated using immunoblotting. Cell proliferation was assessed using an MTS cell proliferation assay kit. Statistical analysis was performed using the Student's t-test or analysis of variance, where appropriate., Results: CPB cells demonstrated higher baseline sPLA 2 expression than HET1A cells (P = 0.0005). Treatment with 30 μM sPLA 2 inhibitor significantly attenuated intercellular adhesion molecule-1 (P = 0.004) and vascular cell adhesion molecule-1 (P < 0.0001) expression as well as decreased NF-κB activation (P = 0.002). sPLA 2 inhibition decreased cell proliferation in a dose-dependent manner (P < 0.001 for 15, 20, and 30 μM doses)., Conclusions: sPLA 2 inhibition in human Barrett's cells decreases cellular adhesive properties and NF-κB activation as well as decreases cell proliferation, signifying downregulation of the inflammatory response and possible attenuation of cellular malignant potential. These findings identify sPLA 2 inhibition as a potential chemopreventive target for premalignant lesions of the esophagus., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Almost all animal venoms contain secretory phospholipases A 2 (PLA 2 s), 14 kDa disulfide-rich enzymes that hydrolyze membrane phospholipids at the sn-2 position, releasing lysophospholipids and fatty acids. These proteins, depending on their sequence, show a wide variety of biochemical, toxic and pharmacological effects and deserve to be studied for their numerous possible applications, and to improve antivenom drugs. The cellular localization and activity of a protein can be studied by conjugating it with a tag. In this work, we applied an enzymatic labelling method, using Streptomyces mobaraense transglutaminase, on three snake venom PLA 2 s: a recombinant neuro- and myotoxic group I PLA 2 from Notechis scutatus scutatus, and two myotoxic group II PLA 2 s from Bothrops asper - one of them a natural catalytically inactive variant. We demonstrate that TGase can be used to produce active mono- or bi-derivatives of these three PLA 2 s modified at specific Lys residues, and that all three of these proteins, conjugated with fluorescent peptides, are internalized in primary myotubes., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

The first developed secretory phospholipase A 2 (sPLA 2 ) sensitive liposomal cisplatin formulation (LiPlaCis®) is currently undergoing clinical evaluation. In the present study we revisit and evaluate critical preclinical parameters important for the therapeutic potential and safety of platinum drugs, here oxaliplatin (L-OHP), formulated in sPLA 2 sensitive liposomes. We show the mole percentage of negatively charged phospholipid needed to obtain enzyme-sensitivity for saturated systems is ≥25% for 16-carbon chain lipid membranes, and >40% for 18-chain lipid membranes, which was surprising as 25% is used clinically in LiPlaCis®. Efficient sPLA 2 -dependent growth inhibition of colorectal cancer cells was demonstrated in vitro, where cell membrane degradation and cytolysis depends on the sensitivity of the formulation towards the enzyme and is governed by the amount of lysolipids generated and the presence of serum proteins. We found that serum proteins did not affect the lipase activity of the enzyme towards the membranes but instead sequester the lysolipid byproducts consequently inhibiting their detergent-like cytotoxic properties. In vivo therapeutic potential and safety of the liposomes was investigated in nude mice bearing sPLA 2 -deficient FaDu squamous carcinoma and sPLA 2 -expressing Colo205 colorectal adenocarcinoma. After intravenous injections, the tumor growth was suppressed for liposomal L-OHP relative to free drug, but only a weak response was observed for both slow- and fast-releasing sPLA 2 -sensitive formulations compared to non-sensitive liposomes. Also, the mice did not show longer survival. In turn, for the highly sPLA 2 -sensitive liposomes, multiple high doses caused petechial cutaneous hemorrhages, along with multifocal hepatonecrotic lesions, suggestive of premature activation in skin and liver irrespective of sPLA 2 -status of the tumor engraft. These results indicate that although liposomal carriers can improve the antitumor efficacy of platinum drugs, sPLA 2 -triggered release suffers from a narrow therapeutic index and has safety concerns., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Background: Airway remodeling is a detrimental and refractory process showing age-dependent clinical manifestations that are mechanistically undefined. The leukotriene (LT) and wingless/integrase (Wnt) pathways have been implicated in remodeling, but age-specific expression profiles and common regulators remained elusive., Objective: We sought to study the activation of the LT and Wnt pathways during early- or late-onset allergic airway inflammation and to address regulatory mechanisms and clinical relevance in normal human bronchial epithelial cells (NHBEs) and nasal polyp tissues., Methods: Mice were sensitized with house dust mite (HDM) allergens from days 3, 15, or 60 after birth. Remodeling factors in murine bronchoalveolar lavage fluid, lung tissue, or human nasal polyp tissue were analyzed by means of Western blotting, immunoassays, or histology. Regulatory mechanisms were studied in cytokine/HDM-stimulated NHBEs and macrophages., Results: Bronchoalveolar lavage fluid LT levels were increased in neonatal and adult but reduced in juvenile HDM-sensitized mice. Lungs of neonatally sensitized mice showed increased 5-lipoxygenase levels, whereas adult mice expressed more group 10 secretory phospholipase A 2 , Wnt5a, and transglutaminase 2 (Tgm2). Older mice showed colocalization of Wnt5a and LT enzymes in the epithelium, a pattern also observed in human nasal polyps. IL-4 promoted epithelial Wnt5a secretion, which upregulated macrophage Tgm2 expression, and Tgm2 inhibition in turn reduced LT release. Tgm2, group 10 secretory phospholipase A 2 , and LT enzymes in NHBEs and nasal polyps were refractory to corticosteroids., Conclusion: Our findings reveal age differences in LT and Wnt pathways during airway inflammation and identify a steroid-resistant cascade of Wnt5a, Tgm2, and LTs, which might represent a therapeutic target for airway inflammation and remodeling., (Copyright © 2016 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.)

The full-length sequence of a new secretory phospholipase A2 was identified in opium poppy seedlings (Papaver somniferum L.). The cDNA of poppy phospholipase A2, denoted as pspla2, encodes a protein of 159 amino acids with a 31 amino acid long signal peptide at the N-terminus. PsPLA2 contains a PLA2 signature domain (PA2c), including the Ca(2+)-binding loop (YGKYCGxxxxGC) and the catalytic site motif (DACCxxHDxC) with the conserved catalytic histidine and the calcium-coordinating aspartate residues. The aspartate of the His/Asp dyad playing an important role in animal sPLA2 catalysis is substituted by a serine residue. Furthermore, the PsPLA2 sequence contains 12 conserved cysteine residues to form 6 structural disulfide bonds. The calculated molecular weight of the mature PsPLA2 is 14.0 kDa. Based on the primary structure PsPLA2 belongs to the XIB group of PLA2s. Untagged recombinant PsPLA2 obtained by expression in Escherichia coli, renaturation from inclusion bodies and purification by cation-exchange chromatography was characterized in vitro. The pH optimum for activity of PsPLA2 was found to be pH 7, when using mixed micelles of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) and Triton X-100. PsPLA2 specifically cleaves fatty acids from the sn-2 position of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine and shows a pronounced preference for PC over phosphatidyl ethanolamine, -glycerol and -inositol. The active recombinant enzyme was tested in vitro against natural phospholipids isolated from poppy plants and preferably released the unsaturated fatty acids, linoleic acid and linolenic acid, from the naturally occurring mixture of substrate lipids., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Secretory phospholipase A2 (sPLA2) is an important enzyme that plays a key role in various inflammatory diseases including cancer and its inhibitors have been developed as preventive or therapeutic agents. In the present study, a series of new indole containing isoxazole derivatives (10a-10o) is synthesized and evaluated for their sPLA2 inhibitory activities. All compounds (10a-10o) showed significant sPLA2 inhibition activities both in vitro and in vivo studies which is substantiated in in silico studies. Among all the tested compounds, 10o showed potent sPLA2 inhibition activity, that is comparable or more to ursolic acid (positive control). Further studies demonstrated that 10o showed in vitro antiproliferative activity when tested against MCF-7 breast and DU145 prostate cancer cells. Furthermore, compounds 10a-10o obeyed lipinsky's rule of 5 and suggesting druggable properties. The in vitro, in vivo and in silico results are encouraging and warrant pre-clinical studies to develop sPLA2-inhibitory compound 10o as novel therapeutic agent for various inflammatory disorders and several malignancies., (Copyright © 2016 Elsevier Masson SAS. All rights reserved.)

The pla2 gene encoding a phospholipase A2 (EC 3.1.1.4) of Lactobacillus casei DSM20011 was cloned and expressed in the yeast Kluyveromyces lactis GG799 successfully for the first time. The structural pla2 gene fused in frame with the K. lactis secretion signal α-mating factor was integrated into the LAC4 locus and expressed under the control of the LAC4 promoter. sPLA2 activity was detected in the culture supernatant during shake flask culture of K. lactis/pKLAC1-pla2. In comparison with the control strain K. lactis/pKLAC1, SDS-PAGE analysis revealed a 17-kDa recombinant protein band in K. lactis/pKLAC1-pla2, which was consistent with the predicted molecular weight of the mature protein. Real-time quantitative PCR analysis indicated that the copy number of the integrated pla2 gene ranged from 2 to 6 and positively correlated with sPLA2 activity. When the inducer galactose was used as the carbon source, the sPLA2 activity in the culture supernatant of the recombinant that harbored six pla2 gene copies reached 1.96 ± 0.15 U/mL. The influence of the culture composition and conditions on the recombinant sPLA2 activity in shake flask culture were also studied. When the recombinant was cultured at 30°C in a YPD medium culture volume of 70 mL in a 250-mL shake flask with an initial pH of 7.0, the sPLA2 activity reached 2.16 ± 0.18 U/mL., (Copyright © 2015 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.)

We previously isolated four cDNAs in durum wheat, TdsPLA2I, TdsPLA2II, TdsPLA2III and TdsPLA2IV, that encode proteins with homology to plant secretory phospholipases A2 (sPLA2s) (Verlotta et al., Int. J. Mol. Sci., 14, 2013, 5146-5169). In this study, we have further characterized TdsPLA2II and TdsPLA2III sequences that, on the basis of our previous findings, might encode sPLA2 isoforms with different features. Functional analysis revealed that, similarly to other known sPLA2s, TdsPLA2II and TdsPLA2III have an optimum at pH 9.0, require Ca(2+), are heat stable, and are inhibited by the disulfide-bond-reducing agent dithiothreitol. However, differences emerged between these TdsPLA2 isoforms. Transcript analysis revealed that the TdsPLA2III gene is highly up-regulated under different environmental stresses; conversely, the TdsPLA2II gene is expressed at constant levels under almost all of the stress conditions examined. Moreover, TdsPLA2II is saturated at micromolar substrate and Ca(2+) concentrations, whereas TdsPLA2III requires millimolar concentrations to reach maximal activity. This suggests that TdsPLA2II normally functions under optimal conditions in vivo, whereas TdsPLA2III is only partially activated, depending on the specific phospholipid and Ca(2+) levels. Altogether these data lead to the hypothesis that in vivo TdsPLA2II and TdsPLA2III are differently regulated at both molecular and biochemical level and that TdsPLA2III plays a major role in durum wheat response to adverse environmental conditions., (Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.)

Secretory phospholipase A2 (sPLA2) catalyzes the hydrolysis of sn-2 linkage in the glycerophospholipid, thereby releasing fatty acid and 1-acyl lysophospholipid. Among sPLA2s from various organisms and tissues, group XIV fungal/bacterial sPLA2s are relatively less characterized compared to their mammalian counterparts. Here we report cloning, recombinant expression, refolding, and enzymatic characterization of two sPLA2s, NCU06650 and NCU09423, from the filamentous fungus Neurospora crassa. The hexahistidine-tagged putative mature region of both proteins was expressed in Escherichia coli. Inclusion bodies were solubilized using a high hydrostatic pressure refolding technique. NCU06650 was solubilized without any additives at alkaline pH, and the addition of arginine or non-detergent sulfobetain (NDSB) significantly improved the process at acidic pH. In contrast, NCU09423 was solubilized only when NDSB was added at alkaline pH. Both enzymes displayed a Ca(2+)-dependent lipolytic activity toward E. coli membrane. Mass spectrometry analysis using the synthetic phospholipids as substrates demonstrated that both enzymes preferentially cleaved the sn-2 ester linkage of substrates and generated 1-acyl lysophospholipids, demonstrating that they are bona fide PLA2., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Phospholipase A2 receptor 1 (PLA2R) mediates collagen-dependent migration. The mechanisms by which PLA2R interacts with collagen remain unclear. We produced HEK293 cells expressing full-length wild-type PLA2R or a truncated PLA2R that lacks fibronectin-like type II (FNII) domains or several regions of C-type lectin-like domain (CTLD). We show that the CTLD1-2 as well as the FNII domain of PLA2R are responsible for binding to collagen and for collagen-dependent migration. Thus, multiple regions and domains of the extracellular portion of PLA2R participate in the responses to collagen. These data suggest a potentially new mechanism for PLA2R-mediated biological response beyond that of a receptor for secretory PLA2., (Copyright © 2015. Published by Elsevier B.V.)

Secretory phospholipase A2 (sPLA2) generates bioactive lysophospholipids implicated in acute and chronic inflammation, but the pathophysiologic role of sPLA2 is poorly understood. Given that high-density lipoprotein (HDL) is the major substrate for sPLA2 in plasma, we investigated the effects of sPLA2-mediated modification of HDL (sPLA2-HDL) on neutrophil function, an essential arm of the innate immune response and atherosclerosis. Treatment of neutrophils with sPLA2-HDL rapidly prevented agonist-induced neutrophil activation, including shape change, neutrophil extracellular trap formation, CD11b activation, adhesion under flow and migration of neutrophils. The cholesterol-mobilizing activity of sPLA2-HDL was markedly increased when compared to native HDL, promoting a significant reduction of cholesterol-rich signaling microdomains integral to cellular signaling pathways. Moreover, sPLA2-HDL effectively suppressed agonist-induced rise in intracellular Ca²⁺ levels. Native HDL showed no significant effects and removing lysophospholipids from sPLA2-HDL abolished all anti-inflammatory activities. Overall, our studies suggest that the increased cholesterol-mobilizing activity of sPLA2-HDL and suppression of rise in intracellular Ca²⁺ levels are likely mechanism that counteracts agonist-induced activation of neutrophils. These counterintuitive findings imply that neutrophil trafficking and effector responses are altered by sPLA2-HDL during inflammatory conditions., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Phospholipase A2 (PLA2) cleave phospholipids preferentially at the sn-2 position, liberating free fatty acids and lysophospholipids. They are classified into six main groups based on size, location, function, substrate specificity and calcium requirement. These classes include secretory PLA2 (sPLA2), cytosolic (cPLA2), Ca(2+)-independent (iPLA2), platelet activating factor acetylhydrolases (PAF-AH), lysosomal PLA2 (LyPLA2) and adipose specific PLA2 (AdPLA2). It is hypothesized that PLA2 can serve as pharmacological targets for the therapeutic treatment of several diseases, including cardiovascular diseases, atherosclerosis, immune disorders and cancer. Special emphasis has been placed on inhibitors of sPLA2 isoforms as pharmacological moieties, mostly due to the fact that these enzymes are activated during inflammatory events and because their expression is increased in several diseases. This review focuses on understanding how sPLA2 isoform expression is altered during disease progression and the possible therapeutic interventions to specifically target sPLA2 isoforms, including new approaches using nano-particulate-based strategies., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Ethnopharmacological Relevance: Evening primrose (Oenothera biennis L., Onagraceae) is a wild medicinal plant of Central American origin that is now one of the most widely used herbal medicines in different parts of the world. Oil extracted from it seeds is traditionally used in the treatment of eczema, asthma, rheumatoid arthritis, breast problem, premenstrual and menopausal syndrome, all they have an inflammatory component. The present study demonstrates the in vitro anti-inflammatory effect of long-chain fatty alcohols, minor compounds isolated from Evening primrose oil (EPO)., Material and Methods: A mixture of long chain fatty alcohols (LCFAs) was isolated from the non-triacylglycerol fraction of the EPO. Hexacosanol (C26OH: 38.65%), tetracosanol (C24OH: 31.59%), docosanol (C22OH: 11.36%) and octocosanol (C28OH: 7.64%), were the major constituents, identified and quantified by GC and GC-MS. LCFA was tested with LPS stimulated murine peritoneal macrophage. This fraction, significantly and dose-dependently decreased nitric oxide production induced by LPS (P<0.001) and the inhibitory effect seems to be consequence of an action at the level of the inducible nitric-oxide synthethase (iNOS) gene enzyme expression rather than to a direct inhibitory action on enzyme activity. The release of PLA2 and TXB2 also was significantly inhibited by LCFAs (P<0.001) although LCFAs did not affect to PGE2 generation, however the western blot assay showed that LCFAs reduced cyclooxygenase-2 enzyme gene expression at all doses assayed. In the same way, the secretion of inflammatory cytokines interleukin 1β (IL-1β) and tumour necrosis factor α (TNF-α) from LPS-stimulated murine macrophage, were also significantly reduced (P<0.001)., Conclusion: These results demonstrates the anti-inflammatory activity of LCFAs, providing an additional value about the role of bioactive minor compounds in the beneficial effect of EPO and supports its traditional uses in inflammatory processes management., (© 2013 Elsevier Ireland Ltd. All rights reserved.)

Human non-pancreatic secretory phospholipase A2 (hnpsPLA2) is a group IIA phospholipase A2 which plays an important role in the innate immune response. This enzyme was found to exhibit bactericidal activity toward Gram-positive bacteria, but not Gram-negative ones. Though native hnpsPLA2 is active over a broad pH range, it is only highly active at alkaline conditions with the optimum activity pH of about 8.5. In order to make it highly active at neutral pH, we have obtained two hnpsPLA2 mutants, Glu89Lys and Arg100Glu that work better at neutral pH in a previous study. In the present study, we tested the bactericidal effects of the native hnpsPLA2 and the two mutants. Both native hnpsPLA2 and the two mutants exhibit bactericidal activity toward Gram-positive bacteria. Furthermore, they can also kill Escherichia coli, a Gram-negative bacterium. The two mutants showed better bactericidal activity for E. coli at neutral pH than the native enzyme, which is consistent with the enzyme activities. As hnpsPLA2 is highly stable and biocompatible, it may provide a promising therapy for bacteria infection treatment or other bactericidal applications., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Objective: Secretory phospholipase A2 (sPLA2) enzymes are thought to contribute to atherosclerosis. In this study we assessed levels of sPLA2 mass and activity, and their relationship to baseline characteristics of children with familial hypercholesterolemia (FH). Furthermore, we evaluated the effect of two years of pravastatin therapy on sPLA2 levels., Methods and Results: sPLA2-IIA mass and sPLA2 activity were measured at baseline and after two years in 187 children with FH (aged 8-18 years) randomized to pravastatin or placebo. At baseline, median [IQR] sPLA2-IIA mass and sPLA2 activity levels were 7.2 [5.8-13.2] ng/ml and 36.4 [29.8-47.1] U/ml, respectively. Both sPLA2-IIA mass and sPLA2 activity were significantly correlated with high-sensitivity C-reactive protein (r = 0.33, p < 0.001 and r = 0.386, p < 0 .001, respectively), but not with other cardiovascular risk factors. Baseline levels of sPLA2-IIA mass and sPLA2 activity were not significantly associated with carotid intima-media thickness (cIMT) at baseline or at the end of follow-up. After two years, sPLA2-IIA mass and sPLA2 activity levels were not significantly reduced in the pravastatin group (p = 0.20 and p = 0.63, respectively), nor in the placebo group (p = 0.17 and p = 0.11, respectively). Changes from baseline did not differ between the treatment groups for sPLA2-IIA mass (p = 0.48) and sPLA2 activity (p = 0.88)., Conclusions: sPLA2-IIA mass and sPLA2 activity were not significantly associated with cIMT in our pediatric FH cohort. This could indicate that the potential predictive role of sPLA2 as a biomarker of cardiovascular disease in children with FH is limited. Treatment with pravastatin did not reduce sPLA2-IIA mass or sPLA2 activity levels, as compared to placebo. Further studies with larger samples are required to address these issues., (Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.)

Iron accumulation and oxidative stress are hallmarks of retinas from patients with age-related macular degeneration (AMD). We have previously demonstrated that iron-overloaded retinas are a good in vitro model for the study of retinal degeneration during iron-induced oxidative stress. In this model we have previously characterized the role of cytosolic phospholipase A2 (cPLA2) and calcium-independent isoform (iPLA2). The aim of the present study was to analyze the implications of Group V secretory PLA2 (sPLA2), another member of PLA2 family, in cyclooxygenase (COX)-2 and nuclear factor kappa B (NF-κB) regulation. We found that sPLA2 is localized in cytosolic fraction in an iron concentration-dependent manner. By immunoprecipitation (IP) assays we also demonstrated an increased association between Group V sPLA2 and COX-2 in retinas exposed to iron overload. However, COX-2 activity in IP assays was observed to decrease in spite of the increased protein levels observed. p65 (RelA) NF-κB levels were increased in nuclear fractions from retinas exposed to iron. In the presence of ATK (cPLA2 inhibitor) and YM 26734 (sPLA2 inhibitor), the nuclear localization of both p65 and p50 NF-κB subunits was restored to control levels in retinas exposed to iron-induced oxidative stress. Membrane repair mechanisms were also analyzed by studying the participation of acyltransferases in phospholipid remodeling during retinal oxidation stress. Acidic phospholipids, such as phosphatidylinositol (PI) and phosphatidylserine (PS), were observed to show an inhibited acylation profile in retinas exposed to iron while phosphatidylethanolamine (PE) showed the opposite. The use of PLA2 inhibitors demonstrated that PS is actively deacylated during iron-induced oxidative stress. Results from the present study suggest that Group V sPLA2 has multiple intracellular targets during iron-induced retinal degeneration and that the specific role of sPLA2 could be related to inflammatory responses by its participation in NF-κB and COX-2 regulation., (Copyright © 2013 Elsevier Ltd. All rights reserved.)