The interaction of secreted phospholipase A2-IIA with the microbiota alters its lipidome and promotes inflammation
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA783025 | ENA |
REPOSITORIES: ENA
Dataset's files
| Action | DRS | |||
|---|---|---|---|---|
| SRR17020900_1.fastq.gz | Fastqsanger.gz | |||
| SRR17020900_2.fastq.gz | Fastqsanger.gz | |||
| SRR17021000_1.fastq.gz | Fastqsanger.gz | |||
| SRR17021000_2.fastq.gz | Fastqsanger.gz | |||
| SRR17020901_1.fastq.gz | Fastqsanger.gz |
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Project description:Secreted phospholipase A2-IIA (sPLA2-IIA) hydrolyzes phospholipids to liberate lysophospholipids and fatty acids. Given its poor activity toward eukaryotic cell membranes, its role in the generation of proinflammatory lipid mediators is unclear. Conversely, sPLA2-IIA efficiently hydrolyzes bacterial membranes. Here, we show that sPLA2-IIA impacts on the immune system by acting on the intestinal microbial flora. Using mice overexpressing transgene-driven human sPLA2-IIA, we found that the intestinal microbiota was critical for both induction of an immune phenotype and promotion of inflammatory arthritis. The expression of sPLA2-IIA led to alterations of the intestinal microbiota composition, but housing in a more stringent pathogen-free facility revealed that its expression could affect the immune system in the absence of changes to the composition of this flora. In contrast, untargeted lipidomic analysis focusing on bacteria-derived lipid mediators revealed that sPLA2-IIA could profoundly alter the fecal lipidome. The data suggest that a singular protein, sPLA2-IIA, produces systemic effects on the immune system through its activity on the microbiota and its lipidome.
2021-11-25 | GSE189441 | GEO
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:Simplified analogs of YM-26734, a known inhibitor of secreted phospholipase A(2) (sPLA(2)) group IIA, were synthesized and found to also display potent inhibition at low nanomolar concentrations. Analogs were based on the didodecanoylphloroglucinol portion of YM-26734 which contains the predicted active site calcium binding group.
| S-EPMC2578825 | biostudies-literature
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:Metabolic disorders including obesity and insulin resistance have their basis in dysregulated lipid metabolism and low-grade inflammation. In a microarray search of unique lipase-related genes whose expressions are associated with obesity, we found that two secreted phospholipase A2s (sPLA2s), PLA2G5 and PLA2G2E, were robustly induced in adipocytes of obese mice. Analyses of Pla2g5-/- and Pla2g2e-/- mice revealed distinct and previously unrecognized roles of these sPLA2s in diet-induced obesity. PLA2G5 hydrolyzed phosphatidylcholine in fat-overladen low-density lipoprotein to release unsaturated fatty acids, which prevented palmitate-induced M1 macrophage polarization. As such, PLA2G5 tipped the immune balance toward an M2 state, thereby counteracting adipose tissue inflammation, insulin resistance, hyperlipidemia and obesiy. PLA2G2E altered minor lipoprotein phospholipids, phosphatidylserine and phosphatidylethanolamine, and moderately facilitated lipid accumulation in adipose tissue and liver. Collectively, the identification of metabolic sPLA2s adds this gene family to a growing list of lipolytic enzymes that act as metabolic coordinators. white adipose tissues of C57BL/6 mice; two-condition experimentM-bM-^@M-^Shigh fat diet or low fat diet feeding for 18 weeks; 2 replicates, respectively
2014-03-20 | E-GEOD-56038 | biostudies-arrayexpress
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:Human group IIA secretory phospholipase A2 (hGIIA) promotes the proliferation of cancer cells, making it a compelling therapeutic target, but it is also significant in other inflammatory conditions. Consequently, suitable inhibitors of hGIIA have always been sought. The activation of phospholipases A2 and the catalysis of glycerophospholipid substrates generally leads to the release of fatty acids such as arachidonic acid (AA) and lysophospholipid, which are then converted to mediator compounds, including prostaglandins, leukotrienes, and the platelet-activating factor. However, this ability of hGIIA to provide AA is not a complete explanation of its biological role in inflammation, as it has now been shown that it also exerts proinflammatory effects by a catalysis-independent mechanism. This mechanism is likely to be highly dependent on key specific molecular interactions, and the full mechanistic descriptions of this remain elusive. The current candidates for the protein partners that may mediate this catalysis-independent mechanism are also introduced in this review. A key discovery has been that selective inhibition of the catalysis-independent activity of hGIIA is achieved with cyclised derivatives of a pentapeptide, FLSYK, derived from the primary sequence of hGIIA. The effects of hGIIA on cell function appear to vary depending on the pathology studied, and so its mechanism of action is complex and context-dependent. This review is comprehensive and covers the most recent developments in the understanding of the many facets of hGIIA function and inhibition and the insight they provide into their clinical application for disease treatment. A cyclic analogue of FLSYK, c2, the most potent analogue known, has now been taken into clinical trials targeting advanced prostate cancer.
| S-EPMC7583969 | biostudies-literature
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. Mast cell maturation; immature and mature bone marrow-derived mast cells (BMMCs); Four-condition experiment (mature BMMCs vs immature BMMCs, Pla2g3M-bM-^@M-^S/M-bM-^@M-^S vs Pla2g3+/+); 3 replicates of Pla2g3+/+ BMMCs, 4 replicates of Pla2g3M-bM-^@M-^S/M-bM-^@M-^S BMMCs, 4 replicates of Pla2g3+/+ cocultured BMMCs, 3 replicates of Pla2g3M-bM-^@M-^S/M-bM-^@M-^S cocultured BMMCs
2013-03-09 | E-GEOD-44980 | biostudies-arrayexpress
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
Project description:There is an urgent need to identify the cellular and molecular mechanisms responsible for severe COVID-19 that results in death. We initially performed both untargeted and targeted lipidomics as well as focused biochemical analyses of 127 plasma samples and found elevated metabolites associated with secreted phospholipase A2 (sPLA2) activity and mitochondrial dysfunction in patients with severe COVID-19. Deceased COVID-19 patients had higher levels of circulating, catalytically active sPLA2 group IIA (sPLA2-IIA), with a median value that was 9.6-fold higher than that for patients with mild disease and 5.0-fold higher than the median value for survivors of severe COVID-19. Elevated sPLA2-IIA levels paralleled several indices of COVID-19 disease severity (e.g., kidney dysfunction, hypoxia, multiple organ dysfunction). A decision tree generated by machine learning identified sPLA2-IIA levels as a central node in the stratification of patients who died from COVID-19. Random forest analysis and least absolute shrinkage and selection operator-based (LASSO-based) regression analysis additionally identified sPLA2-IIA and blood urea nitrogen (BUN) as the key variables among 80 clinical indices in predicting COVID-19 mortality. The combined PLA-BUN index performed significantly better than did either one alone. An independent cohort (n = 154) confirmed higher plasma sPLA2-IIA levels in deceased patients compared with levels in plasma from patients with severe or mild COVID-19, with the PLA-BUN index-based decision tree satisfactorily stratifying patients with mild, severe, or fatal COVID-19. With clinically tested inhibitors available, this study identifies sPLA2-IIA as a therapeutic target to reduce COVID-19 mortality.
| S-EPMC8483752 | biostudies-literature