Group IVE Cytosolic Phospholipase A2 Limits Psoriatic Inflammation by Mobilizing the Anti-inflammatory Lipid N-Acylethanolamine
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PROVIDER: PRJNA804886 | ENA |
REPOSITORIES: ENA
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Project description:Psoriasis is an inflammatory disorder characterized by keratinocyte hyper-proliferation and Th17-type immune responses. However, the roles of bioactive lipids and the regulation of their biosynthesis in this chronic skin disease are not fully understood. Herein, we show that group IVE cytosolic phospholipase A2 (cPLA2epsilon/PLA2G4E) plays a counterregulatory role against psoriatic inflammation by producing the non-canonical anti-inflammatory lipid N-acylethanolamine (NAE). Lipidomics analysis of mouse skin revealed that NAE species and their precursors (N-acyl-phosphatidylethanolamine and glycerophospho-N-acylethanolamine) were robustly increased in parallel with the ongoing process of imiquimod (IMQ)-induced psoriasis, accompanied by a marked upregulation of cPLA2epsilon in epidermal keratinocytes. Genetic deletion of cPLA2epsilon/Pla2g4e exacerbated IMQ-induced ear swelling and psoriatic marker expression, with a dramatic reduction of NAE-related lipids in IMQ-treated, and even normal, skin. Stimulation of cultured human keratinocytes with psoriatic cytokines concomitantly increased PLA2G4E expression and NAE production, and supplementation with NAEs significantly attenuated the cytokine-induced upregulation of the psoriatic marker S100A9. Increased expression of cPLA2epsilon was also evident in the epidermis of psoriatic patients. These findings reveal for the first time the in vivo role of cPLA2epsilon, which is highly induced in the keratinocytes of the psoriatic skin, promotes the biosynthesis of NAE-related lipids, and contributes to limiting psoriatic inflammation.
2022-03-31 | GSE196431 | GEO
Project description:Cytosolic phospholipase A2 alpha regulates TLR signaling and migration in metastatic 4T1 cells
| PRJNA574187 | ENA
Project description:Within the secreted phospholipase A2 (sPLA2) family, group X sPLA2 (sPLA2-X) has the highest capacity to hydrolyze cellular membranes and has long been thought to promote inflammation by releasing arachidonic acid (AA), a precursor of pro-inflammatory eicosanoids. Unexpectedly, we found that transgenic mice globally overexpressing human sPLA2-X (PLA2G10-Tg) displayed striking immunosuppressive and lean phenotypes with lymphopenia and increased M2-like macrophages, accompanied by marked elevation of free omega-3 polyunsaturated fatty acids (PUFAs) and their metabolites. Studies using Pla2g10-deficient mice revealed that endogenous sPLA2-X, which is highly expressed in the colon epithelium and spermatozoa, mobilized omega-3 PUFAs or their metabolites to protect against dextran sulfate sodium (DSS)-induced colitis and to promote fertilization, respectively. In colitis, sPLA2-X deficiency increased colorectal expression of Th17 cytokines, and omega-3 PUFAs attenuated their production by lamina propria cells partly through the fatty acid receptor GPR120. In comparison, cytosolic phospholipase A2 (cPLA2alpha) protects from colitis by mobilizing omega-6 AA metabolites including prostaglandin E2. Thus, our results underscore a previously unrecognized role of sPLA2-X as an omega-3 PUFA mobilizer in vivo, segregated mobilization of omega-3 and omega-6 PUFA metabolites by sPLA2-X and cPLA2alpha, respectively, in protection against colitis, and the novel role of a particular sPLA2-X-driven PUFA in fertilization.
2016-02-01 | GSE77144 | GEO
Project description:The role of Group IVA cytosolic phospholipase A2 (cPLA2M-NM-1) activation in regulating macrophage transcriptional responses to Candida albicans infection was investigated. cPLA2M-NM-1 releases arachidonic acid for the production of eicosanoids. In mouse resident peritoneal macrophages, prostacyclin, prostaglandin E2 and leukotriene C4 were produced within minutes of C. albicans addition before cyclooxygenase 2 expression. The production of TNFa was lower in C. albicans-stimulated cPLA2a+/+ than cPLA2a-/- macrophages due to an autocrine effect of prostaglandins that increased cAMP to a greater extent in cPLA2a+/+ than cPLA2a-/- macrophages. For global insight, differential gene expression in C. albicans-stimulated cPLA2a+/+ and cPLA2a-/- macrophages (3 h) was compared by microarray. cPLA2M-NM-1+/+ macrophages expressed 86 genes at lower levels and 181 genes at higher levels than cPLA2M-NM-1-/- macrophages (M-bM-^IM-%2-fold, p<0.05 ). Several pro-inflammatory genes were expressed at lower levels (Tnfa, Cx3cl1, Cd40, Ifng, several IFNg-inducible GTPases, Ccl5, Csf1, Edn1, CxCr7, Irf1, Irf4, Akna). Genes that dampen inflammation (Socs3, Il10, Crem, Stat3, Thbd, Thbs1, Abca1) and genes involved in host defense (Gja1, Csf3, Trem1, Hdc) were expressed at higher levels in cPLA2a+/+ macrophages. Representative genes expressed lower in cPLA2a+/+ macrophages (Tnfa and Csf1) were increased by treatment with a prostacyclin receptor antagonist and protein kinase A inhibitor, whereas genes expressed at higher levels (Crem, Nr4a2, Il10, Csf3) were suppressed. The results suggest that C. albicans stimulates an autocrine loop in macrophages involving cPLA2a, cyclooxygenase 1-derived prostaglandins and increased cAMP that globally effects expression of genes involved in host defense and inflammation. Resident peritoneal macrophages from Group IVA cytosolic phospholipase A2 (cPLA2a) +/+ and -/- mice were stimulated with Candida albicans (m.o.i. 2) for 3 hours and RNA isolated to evaluate the role of cPLA2a-derived lipid mediators on gene expression. Three independent experiments were analyzed.
2013-05-02 | E-GEOD-46533 | biostudies-arrayexpress
Project description:Besides promoting inflammation by mobilizing lipid mediators, secreted phospholipase A2 group IIA (sPLA2-IIA) prevents bacterial infection by degrading bacterial membranes. Here we show that despite the restricted intestinal expression of sPLA2-IIA in BALB/c mice, its genetic deletion leads to amelioration of cancer and exacerbation of psoriasis in distal skin. Intestinal expression of sPLA2-IIA is reduced after antibiotics treatment or under germ-free conditions, suggesting its upregulation by gut microbiota. Metagenome, transcriptome and metabolome analyses have revealed that sPLA2-IIA deficiency alters the gut microbiota, accompanied by notable changes in the intestinal expression of genes related to immunity and metabolism as well as the levels of various blood metabolites and fecal bacterial lipids, suggesting that sPLA2-IIA contributes to shaping of the gut microbiota. The skin phenotypes in Pla2g2a–/– mice are lost when they are co-housed with littermate wild-type mice, resulting in mixing of the microbiota between the genotypes, or when they are housed in a more stringent pathogen-free facility, where Pla2g2a expression in wild-type mice is low and the gut microbial compositions in both genotypes are nearly identical. Thus, our results highlight a new aspect of sPLA2-IIA as a modulator of gut microbiota, perturbation of which affects distal skin responses.
2022-01-01 | GSE182283 | GEO
Project description:Microenvironment-based alterations in mast cell phenotypes influence the susceptibility to anaphylaxis, yet the mechanisms underlying proper maturation of mast cells toward an anaphylaxis-sensitive phenotype are incompletely understood. Here we report that PLA2G3, a mammalian homolog of anaphylactic bee venom phospholipase A2, regulates this process. PLA2G3 secreted from mast cells is coupled with fibroblastic lipocalin-type PGD2 synthase (L-PGDS) to provide PGD2, which facilitates mast cell maturation via PGD2 receptor (DP1). Mice lacking PLA2G3, L-PGDS or DP1, mast cell-deficient mice reconstituted with PLA2G3- or DP1-null mast cells, or mast cells cocultured with L-PGDS-ablated fibroblasts exhibited impaired mast cell maturation and anaphylaxis. Thus, we describe a lipid-driven PLA2G3-L-PGDS-DP1 loop that drives mast cell maturation.
2013-03-09 | GSE44980 | GEO
Project description:Effect of group III phospholipase A2 deletion in antigen-induced asthma modeled lung
| PRJNA1047533 | ENA
Project description: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 of unsaturated fatty acids such as arachidonic acid (AA), a precursor of pro-inflammatory eicosanoids. Several lines of evidence point to toll-like receptors (TLRs) as drivers of synovitis and joint destruction in RA. However, few studies have addressed the implication of PLA2 activity downstream TLR activation in the synovium. Here, we aimed to characterize PLA2 enzyme involvement in TLR2-induced signaling in synovial fibroblast-like cells. TLRs1-7 and a range of sPLA2, iPLA2 and cPLA2 enzymes were found to be transcriptionally expressed in cultured synoviocytes. Activation of TLR2/1 and TLR2/6 led to phosphorylation of cPLA2α at Ser505, and induced AA release and PGE2 production; effects that were attenuated by cPLA2α inhibitors. In contrast, sPLA2 inhibitors did not affect AA or PGE2 release. cPLA2α inhibitors furthermore attenuated TLR-induced expression of IL-6, IL-8 and COX2. COX1/2 inhibitors attenuated TLR2/6-induced IL-6 transcription and protein production comparable to cPLA2α inhibition. Moreover, exogenously PGE2 added alone induced IL-6 production and completely rescued IL-6 transcription when added simultaneously with FSL-1 in the presence of a cPLA2α inhibitor. Our results demonstrate for the first time that cPLA2α is involved in TLR2/1- and TLR2/6-induced AA release, PGE2 production and pro-inflammatory cytokine expression in synoviocytes, possibly through COX/PGE2-dependent pathways. These findings expand our understanding of cPLA2α as a modulator of inflammatory molecular mechanisms in chronic diseases such as RA.
| S-EPMC4404349 | biostudies-literature
Project description:The role of Group IVA cytosolic phospholipase A2 (cPLA2α) activation in regulating macrophage transcriptional responses to Candida albicans infection was investigated. cPLA2α releases arachidonic acid for the production of eicosanoids. In mouse resident peritoneal macrophages, prostacyclin, prostaglandin E2 and leukotriene C4 were produced within minutes of C. albicans addition before cyclooxygenase 2 expression. The production of TNFa was lower in C. albicans-stimulated cPLA2a+/+ than cPLA2a-/- macrophages due to an autocrine effect of prostaglandins that increased cAMP to a greater extent in cPLA2a+/+ than cPLA2a-/- macrophages. For global insight, differential gene expression in C. albicans-stimulated cPLA2a+/+ and cPLA2a-/- macrophages (3 h) was compared by microarray. cPLA2α+/+ macrophages expressed 86 genes at lower levels and 181 genes at higher levels than cPLA2α-/- macrophages (≥2-fold, p<0.05 ). Several pro-inflammatory genes were expressed at lower levels (Tnfa, Cx3cl1, Cd40, Ifng, several IFNg-inducible GTPases, Ccl5, Csf1, Edn1, CxCr7, Irf1, Irf4, Akna). Genes that dampen inflammation (Socs3, Il10, Crem, Stat3, Thbd, Thbs1, Abca1) and genes involved in host defense (Gja1, Csf3, Trem1, Hdc) were expressed at higher levels in cPLA2a+/+ macrophages. Representative genes expressed lower in cPLA2a+/+ macrophages (Tnfa and Csf1) were increased by treatment with a prostacyclin receptor antagonist and protein kinase A inhibitor, whereas genes expressed at higher levels (Crem, Nr4a2, Il10, Csf3) were suppressed. The results suggest that C. albicans stimulates an autocrine loop in macrophages involving cPLA2a, cyclooxygenase 1-derived prostaglandins and increased cAMP that globally effects expression of genes involved in host defense and inflammation.
2013-05-02 | GSE46533 | GEO
Project description:Lipid mediators play pivotal roles in colorectal cancer and colitis, but only a limited member of the phospholipase A2 (PLA2) subtypes, which lie upstream of various lipid mediators, have been implicated in the positive or negative regulation of these diseases. Clinical and biochemical evidence suggests that secreted PLA2 group III (sPLA2-III) is associated with colorectal cancer, although its precise role remains obscure. Here we have found that sPLA2-III-null (Pla2g3-/-) mice are highly resistant to colon carcinogenesis. Furthermore, Pla2g3-/- mice are less susceptible to dextran sulfateinduced colitis, implying that the amelioration of colonic inflammation by sPLA2-III ablation may underlie the protective effect against colon cancer. Lipidomics analysis of the colon revealed significant reduction of pro-inflammatory/pro-tumorigenic lysophosholipids as well as unusual elevation of colon-protective fatty acids and their oxygenated metabolites in Pla2g3-/- mice. Overall, our results establish a role of sPLA2-III in the promotion of colorectal inflammation and cancer, expand our understanding of the divergent roles of multiple PLA2 enzymes in the gastrointestinal tract, and point to sPLA2-III as a novel druggable target for colorectal diseases.
2017-11-01 | GSE102389 | GEO