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2.
Artigo em Inglês | MEDLINE | ID: mdl-33535020

RESUMO

RATIONALE: A link between sphingolipids, 17q21 genetic variants and childhood asthma has been suggested, but the underlying mechanisms and characteristics of such asthma endotype remain to be elucidated. OBJECTIVE: To study the sphingolipid-associated childhood asthma endotype using multi-omics data. METHODS: We used untargeted LC-MS plasma metabolomics profiles at age 6 months and 6 years from >500 children in the COPSAC2010 birth cohort focusing on sphingolipids, and integrated 17q21 genotype and nasal gene expression of serine palmitoyl-CoA transferase (SPT), i.e. the rate-limiting enzyme in the de novo sphingolipid synthesis, in relation to asthma development and lung function traits from infancy till age 6 years. Replication was sought in the independent VDAART cohort. MEASUREMENTS AND MAIN RESULTS: Lower levels of ceramides and sphingomyelins at age 6 months were associated with increased risk of developing asthma before age 3, which was also observed in VDAART. At age 6 years, lower levels of key phosphosphingolipids, e.g. sphinganine-1-phosphate were associated with increased airway resistance. This relationship was dependent on 17q21 genotype and nasal SPT gene expression with significant interaction between genotype and phosphosphingolipids levels and between genotype and SPT expression, showing lower phosphosphingolipids and reduced SPT expression with increasing number of at-risk alleles. However, the findings did not pass FDR<0.05. CONCLUSIONS: This exploratory study suggests the existence of a childhood asthma endotype with early onset and increased airway resistance that is characterized by reduced sphingolipid levels that is associated with 17q21 genetic variants and expression of the SPT enzyme.

4.
Biochim Biophys Acta Mol Cell Biol Lipids ; 1866(5): 158886, 2021 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-33450390

RESUMO

15-hydroxyeicosatetraenoic acid (15-HETE) is an arachidonic acid derived lipid mediator which can originate both from 15-lipoxygenase (15-LOX) activity and cyclooxygenase (COX) activity. The enzymatic source determines the enantiomeric profile of the 15-HETE formed. 15-HETE is the most abundant arachidonic acid metabolite in the human lung and has been suggested to influence the pathophysiology of asthma. Mast cells are central effectors in asthma, but there are contradictory reports on whether 15-HETE originates from 15-LOX or COX in human mast cells. This prompted the current study where the pathway of 15-HETE biosynthesis was examined in three human mast cell models; the cell line LAD2, cord blood derived mast cells (CBMC) and tissue isolated human lung mast cells (HLMC). Levels and enantiomeric profiles of 15-HETE and levels of the downstream metabolite 15-KETE, were analyzed by UPLC-MS/MS after stimulation with anti-IgE or calcium ionophore A23187 in the presence and absence of inhibitors of COX isoenzymes. We found that 15-HETE was produced by COX-1 in human mast cells under these experimental conditions. Unexpectedly, chiral analysis showed that the 15(R) isomer was predominant and gradually accumulated, whereas the 15(S) isomer was metabolized by the 15-hydroxyprostaglandin dehydrogenase. We conclude that during physiological conditions, i.e., without addition of exogenous arachidonic acid, both enantiomers of 15-HETE are produced by COX-1 in human mast cells but that the 15(S) isomer is selectively depleted by undergoing further metabolism. The study highlights that 15-HETE cannot be used as an indicator of 15-LOX activity for cellular studies, unless chirality and sensitivity to pharmacologic inhibition is determined.

5.
Clin Exp Allergy ; 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33449404

RESUMO

BACKGROUND: The major mast cell prostanoid PGD2 is targeted for therapy of asthma and other diseases, because the biological actions include bronchoconstriction, vasodilation and regulation of immune cells mediated by three different receptors. It is not known if the alternative to selectively inhibit the biosynthesis of PGD2 affects release of other prostanoids in human mast cells. OBJECTIVES: To determine the biochemical consequences of inhibition of the hematopoietic prostaglandin D synthase (hPGDS) PGD2 in human mast cells. METHODS: Four human mast cell models, LAD2, cord blood derived mast cells (CBMC), peripheral blood derived mast cells (PBMC) and human lung mast cells (HLMC), were activated by anti-IgE or ionophore A23187. Prostanoids were measured by UPLC-MS/MS. RESULTS: All mast cells almost exclusively released PGD2 when activated by anti-IgE or A23187. The biosynthesis was in all four cell types entirely initiated by COX-1. When pharmacologic inhibition of hPGDS abolished formation of PGD2 , PGE2 was detected and release of TXA2 increased. Conversely, when the thromboxane synthase was inhibited, levels of PGD2 increased. Adding exogenous PGH2 confirmed predominant conversion to PGD2 under control conditions, and increased levels of TXB2 and PGE2 when hPGDS was inhibited. However, PGE2 was formed by non-enzymatic degradation. CONCLUSIONS: Inhibition of hPGDS effectively blocks mast cell dependent PGD2 formation. The inhibition was associated with redirected use of the intermediate PGH2 and shunting into biosynthesis of TXA2 . However, the levels of TXA2 did not reach those of PGD2 in naïve cells. It remains to determine if this diversion occurs in vivo and has clinical relevance.

8.
Proc Natl Acad Sci U S A ; 117(52): 33619-33627, 2020 12 29.
Artigo em Inglês | MEDLINE | ID: mdl-33318177

RESUMO

Intraocular pressure-sensitive retinal ganglion cell degeneration is a hallmark of glaucoma, the leading cause of irreversible blindness. Here, we used RNA-sequencing and metabolomics to examine early glaucoma in DBA/2J mice. We demonstrate gene expression changes that significantly impact pathways mediating the metabolism and transport of glucose and pyruvate. Subsequent metabolic studies characterized an intraocular pressure (IOP)-dependent decline in retinal pyruvate levels coupled to dysregulated glucose metabolism prior to detectable optic nerve degeneration. Remarkably, retinal glucose levels were elevated 50-fold, consistent with decreased glycolysis but possibly including glycogen mobilization and other metabolic changes. Oral supplementation of the glycolytic product pyruvate strongly protected from neurodegeneration in both rat and mouse models of glaucoma. Investigating further, we detected mTOR activation at the mechanistic nexus of neurodegeneration and metabolism. Rapamycin-induced inhibition of mTOR robustly prevented glaucomatous neurodegeneration, supporting a damaging role for IOP-induced mTOR activation in perturbing metabolism and promoting glaucoma. Together, these findings support the use of treatments that limit metabolic disturbances and provide bioenergetic support. Such treatments provide a readily translatable strategy that warrants investigation in clinical trials.


Assuntos
Glaucoma/metabolismo , Glucose/metabolismo , Neuroproteção , Fármacos Neuroprotetores/farmacologia , Ácido Pirúvico/metabolismo , Sirolimo/farmacologia , Animais , Modelos Animais de Doenças , Glaucoma/patologia , Glaucoma/fisiopatologia , Pressão Intraocular/efeitos dos fármacos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos DBA , Degeneração Neural/patologia , Degeneração Neural/fisiopatologia , Neuroproteção/efeitos dos fármacos , Ratos Sprague-Dawley , Retina/efeitos dos fármacos , Retina/patologia , Retina/fisiopatologia , Serina-Treonina Quinases TOR/metabolismo
9.
Artigo em Inglês | MEDLINE | ID: mdl-33229588

RESUMO

Tumor-associated macrophages (TAMs) can have protumor properties, including suppressing immune responses, promoting vascularization and, consequently, augmenting tumor progression. To stop TAM-mediated immunosuppression, we use a novel treatment by injecting antibodies specific for scavenger receptor MARCO, which is expressed on a specific subpopulation of TAMs in the tumor. We now report the location of this TAM as well as the pleiotropic mechanism of action of anti-MARCO antibody treatment on tumor progression and further show that this is potentially relevant to humans. Using specific targeting, we observed decreased tumor vascularization, a switch in the metabolic program of MARCO-expressing macrophages, and activation of natural killer (NK) cell killing through TNF-related apoptosis-inducing ligand (TRAIL). This latter activity reverses the effect of melanoma cell-conditioned macrophages in blocking NK activation and synergizes with T cell-directed immunotherapy, such as antibodies to PD-1 or PD-L1, to enhance tumor killing. Our study thus reveals an approach to targeting the immunosuppressive tumor microenvironment with monoclonal antibodies to enhance NK cell activation and NK cell-mediated killing. This can complement existing T cell-directed immunotherapy, providing a promising approach to combinatorial immunotherapy for cancer.

10.
Metabolites ; 10(11)2020 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-33182712

RESUMO

Human health and well-being are intricately linked to environmental quality. Environmental exposures can have lifelong consequences. In particular, exposures during the vulnerable fetal or early development period can affect structure, physiology and metabolism, causing potential adverse, often permanent, health effects at any point in life. External exposures, such as the "chemical exposome" (exposures to environmental chemicals), affect the host's metabolism and immune system, which, in turn, mediate the risk of various diseases. Linking such exposures to adverse outcomes, via intermediate phenotypes such as the metabolome, is one of the central themes of exposome research. Much progress has been made in this line of research, including addressing some key challenges such as analytical coverage of the exposome and metabolome, as well as the integration of heterogeneous, multi-omics data. There is strong evidence that chemical exposures have a marked impact on the metabolome, associating with specific disease risks. Herein, we review recent progress in the field of exposome research as related to human health as well as selected metabolic and autoimmune diseases, with specific emphasis on the impacts of chemical exposures on the host metabolome.

11.
Eur Respir Rev ; 29(157)2020 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-33004525

RESUMO

Lung cancer is the leading cause of death from cancer worldwide. Recent studies demonstrated that the tumour microenvironment (TME) is pivotal for tumour progression, providing multiple targeting opportunities for therapeutic strategies. As one of the most abundant stromal cell types in the TME, tumour-associated macrophages (TAMs) exhibit high plasticity. Malignant cells alter their metabolic profiles to adapt to the limited availability of oxygen and nutrients in the TME, resulting in functional alteration of TAMs. The metabolic features of TAMs are strongly associated with their functional plasticity, which further impacts metabolic profiling in the TME and contributes to tumourigenesis and progression. Here, we review the functional determination of the TME by TAM metabolic alterations, including glycolysis as well as fatty acid and amino acid metabolism, which in turn are influenced by environmental changes. Additionally, we discuss metabolic reprogramming of TAMs to a tumouricidal phenotype as a potential antitumoural therapeutic strategy.

13.
Artigo em Inglês | MEDLINE | ID: mdl-32750662

RESUMO

Cystic fibrosis (CF) is a recessively inherited fatal disease that is the subject of extensive research and ongoing development of therapeutics targeting the defective protein, cystic fibrosis transmembrane conductance regulator (CFTR). Despite progress, the link between CFTR and clinical symptoms is incomplete. The severe CF phenotypes are associated with a deficiency of linoleic acid, which is the precursor of arachidonic acid. The release of arachidonic acid from membranes via phospholipase A2 is the rate-limiting step for eicosanoid synthesis and is increased in CF, which contributes to the observed inflammation. A potential deficiency of docosahexaenoic acid may lead to decreased levels of specialized pro-resolving mediators. This pathophysiology may contribute to an early and sterile inflammation, mucus production, and to bacterial colonization, which further increases inflammation and potentiates the clinical symptoms. Advances in lipid technology will assist in elucidating the role of lipid metabolism in CF, and stimulate therapeutic modulations of inflammation.


Assuntos
Ácido Araquidônico/metabolismo , Regulador de Condutância Transmembrana em Fibrose Cística/metabolismo , Fibrose Cística/metabolismo , Ácidos Docosa-Hexaenoicos/deficiência , Ácido Linoleico/deficiência , Ácido Araquidônico/deficiência , Fibrose Cística/fisiopatologia , Humanos , Inflamação/metabolismo , Ácido Linoleico/metabolismo , Metabolismo dos Lipídeos , Pulmão/metabolismo , Pulmão/microbiologia , Pulmão/fisiopatologia , Muco/metabolismo
14.
Front Immunol ; 11: 1968, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32849657

RESUMO

Immune surveillance of cancer cells is facilitated by the Natural Killer Group 2D (NKG2D) receptor expressed by different lymphocyte subsets. It recognizes NKG2D ligands that are rarely expressed on healthy cells, but upregulated by tumorigenesis, presenting a target for immunological clearance. The molecular mechanisms responsible for NKG2D ligand regulation remain complex. Here we report that cancer cell metabolism supports constitutive surface expression of the NKG2D ligand MHC class I chain-related proteins A (MICA). Knockout of the N-glycosylation gene N-acetylglucosaminyltransferase V (MGAT5) in HEK293 cells induced altered metabolism and continuous high MICA surface expression. MGAT5 knockout cells were used to examine the association of cell metabolism and MICA expression through genetic, pharmacological and metabolic assays. Findings were verified in cancer cell lines. Cells with constitutive high MICA expression showed enhanced spare respiratory capacity and elevated mitochondrial efflux of citrate, determined by extracellular flux analysis and metabolomics. MICA expression was reduced by inhibitors of mitochondrial function, FCCP and etomoxir e.g., and depended on conversion of citrate to acetyl-CoA and oxaloacetate by ATP citrate lyase, which was also observed in several cancer cell types. Assay for Transposase-Accessible Chromatin using sequencing (ATAC-seq) analysis revealed that upregulated MICA transcription was associated with an open chromatin structure at the MICA transcription start site. We identify mitochondria and cytoplasmic citrate as key regulators of constitutive MICA expression and we propose that metabolic reprogramming of certain cancer cells facilitates MICA expression and NKG2D-mediated immune recognition.

15.
Prostaglandins Other Lipid Mediat ; 151: 106474, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32783924

RESUMO

Meibomian gland dysfunction (MGD) represents a major cause of dry eye and ocular discomfort. Lipid mediators, often termed oxylipins, can be produced enzymatically or non-enzymatically, and may modulate inflammatory processes in MGD. Here, we aimed to assess the longitudinal changes of lipid mediators after various eyelid treatments (eyelid warming and thermopulsation) over 12 weeks. Secondly, we aimed to assess the chirality of mono-hydroxyl lipid mediators from tears of MGD and healthy participants. Tears lipid mediators were extracted from Schirmer's strips and levels were quantified by liquid chromatography mass spectrometry (LC-MS) techniques. We quantified 33 lipid mediators in the tear, 18 of which (including 11-HETE, 20-OH-LTB4, and 15-oxoETE) were reduced significantly after treatment. Changes in concentrations of 10-HDoHE (r = 0.54) and 15-oxoETE (r = 0.54) were correlated to the number of meibomian gland plugs at baseline, so increased severity of MGD was associated with treatment-induced change in lipid mediators. The chiral analysis demonstrated that 5(S)-HETE, 12(S)-HETE, 15(S)-HETE, 14(S)-HDoHE, 17(S)-HDoHE and 11(R)-HETE were produced with significant enantiomeric excess (ee %) in controls compared to patients, due to enantiomer selective enzymatic action, whereas most lipid mediators were racemates in patients, due to dominance of oxidative effects which have no enantiomeric preference. Treatment of MGD restored the concentrations of 15(S)-HETE, 14(S)-HDoHE and 17(S)-HDoHE with significant ee values, suggesting reduction in oxidative action. Overall, MGD therapy reduced pro-inflammatory molecules generated by lipoxygenase and oxidative stress.

16.
Anal Chem ; 92(16): 11310-11317, 2020 08 18.
Artigo em Inglês | MEDLINE | ID: mdl-32648737

RESUMO

Data-independent acquisition mass spectrometry (DIA-MS) is essential for information-rich spectral annotations in untargeted metabolomics. However, the acquired MS2 spectra are highly complex, posing significant annotation challenges. We have developed a correlation-based deconvolution (CorrDec) method that uses ion abundance correlations in multisample studies using DIA-MS as an update of our MS-DIAL software. CorrDec is based on the assumption that peak intensities of precursor and fragment ions correlate across samples and exploits this quantitative information to deconvolute complex DIA spectra. CorrDec clearly improved deconvolution of the original MS-DIAL deconvolution method (MS2Dec) in a dilution series of chemical standards and a 224-sample urinary metabolomics study. The primary advantage of CorrDec over MS2Dec is the ability to discriminate coeluting low-abundance compounds. CorrDec requires the measurement of multiple samples to successfully deconvolute DIA spectra; however, our randomized assessment demonstrated that CorrDec can contribute to studies with as few as 10 unique samples. The presented methodology improves compound annotation and identification in multisample studies and will be useful for applications in large cohort studies.

17.
Artigo em Inglês | MEDLINE | ID: mdl-32667261

RESUMO

RATIONALE: New approaches are needed to guide personalized treatment of asthma. OBJECTIVE: To test if urinary eicosanoid metabolites can direct asthma phenotyping. METHODS: Urinary metabolites of prostaglandins (PGs), cysteinyl-leukotrienes (LTs) and isoprostanes were quantified in the Unbiased Biomarkers for the Prediction of Respiratory Diseases Outcomes (U-BIOPRED) study including 86 adults with mild-to-moderate asthma (MMA), 411 with severe asthma (SA), and 100 healthy controls (HC). Validation was performed internally in 302 SA subjects followed-up after 12-18 months, and externally in 95 adolescents with asthma. MEASUREMENT AND MAIN RESULTS: Metabolite levels in HC were unrelated to age, BMI and sex, except for the PGE2-pathway. Eicosanoid levels were generally greater in MMA relative to HC, with further elevations in SA. However, PGE2-metabolite levels were either the same or lower in male non-smoking asthmatics as in HC. Metabolite levels were unchanged in asthmatics adherent to oral corticosteroid treatment as documented by urinary prednisolone detection, whereas SA treated with omalizumab had lower levels of LTE4 and the PGD2 metabolite 2,3-dinor-11ß-PGF2α. High levels of LTE4 and PGD2-metabolites were associated with lower lung-function, and increased levels of exhaled nitric oxide and eosinophil markers in blood, sputum and urine in U-BIOPRED and in adolescents with asthma. These type-2 (T2) asthma associations were reproduced in the follow-up visit of the U-BIOPRED study, and found to be as sensitive to detect T2 inflammation as the established biomarkers. CONCLUSIONS: Monitoring of urinary eicosanoids can identify T2 asthma and introduces a new non-invasive approach for molecular phenotyping of adult and adolescent asthma. This article is open access and distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives License 4.0 (http://creativecommons.org/licenses/by-nc-nd/4.0/).

18.
Artigo em Inglês | MEDLINE | ID: mdl-32512364

RESUMO

n-3 and n-6 polyunsaturated fatty acids (PUFAs) and their lipid mediator metabolites are associated with inflammation. We investigated the effect of dietary intake of plant- and animal-derived n-3 PUFAs and fish protein on the circulatory concentrations of lipid mediators. Seventy-nine subjects with impaired fasting glucose who completed the controlled dietary intervention after randomization to the fatty fish (FF, n=20), lean fish (LF, n=21), Camelina sativa oil (CSO, n=18) or control group (n=20) for 12 weeks were studied. Lipid mediator profiling from fasting plasma samples before and after the intervention was performed by liquid chromatography-mass spectrometry (LC-MS/MS). The FF diet increased concentrations of 18-hydroxyeicosapentaenoic acid (18-HEPE) and 4- and 17-hydroxydocosahexaenoic acid (4-, 17-HDoHE) derived from eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), respectively. Concentrations of lipid mediators derived from α-linolenic acid (ALA) increased and arachidonic acid (AA) derived 5-iso prostaglandin F2α-VI decreased in the CSO group. There were no significant changes in lipid mediators in the LF group. The dietary intake of both plant and animal-based n-3 PUFAs increased circulatory concentrations of lipid mediators with potential anti-inflammatory properties.

19.
Circulation ; 142(8): 776-789, 2020 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-32506925

RESUMO

BACKGROUND: Aortic valve stenosis (AVS), which is the most common valvular heart disease, causes a progressive narrowing of the aortic valve as a consequence of thickening and calcification of the aortic valve leaflets. The beneficial effects of omega-3 polyunsaturated fatty acids (n-3 PUFAs) in cardiovascular prevention have recently been demonstrated in a large randomized, controlled trial. In addition, n-3 PUFAs serve as the substrate for the synthesis of specialized proresolving mediators, which are known by their potent beneficial anti-inflammatory, proresolving, and tissue-modifying properties in cardiovascular disease. However, the effects of n-3 PUFA and specialized proresolving mediators on AVS have not yet been determined. The aim of this study was to identify the role of n-3 PUFA-derived specialized proresolving mediators in relation to the development of AVS. METHODS: Lipidomic and transcriptomic analyses were performed in human tricuspid aortic valves. Apoe-/- mice and wire injury in C57BL/6J mice were used as models for mechanistic studies. RESULTS: We found that n-3 PUFA incorporation into human stenotic aortic valves was higher in noncalcified regions compared with calcified regions. Liquid chromatography tandem mass spectrometry-based lipid mediator lipidomics identified that the n-3 PUFA-derived specialized proresolving mediator resolvin E1 was dysregulated in calcified regions and acted as a calcification inhibitor. Apoe-/- mice expressing the Caenorhabditis elegans Fat-1 transgene (Fat-1tg×Apoe-/-), which enables the endogenous synthesis of n-3 PUFA and increased valvular n-3 PUFA content, exhibited reduced valve calcification, lower aortic valve leaflet area, increased M2 macrophage polarization, and improved echocardiographic parameters. Finally, abrogation of the resolvin E1 receptor ChemR23 enhanced disease progression, and the beneficial effects of Fat-1tg were abolished in the absence of ChemR23. CONCLUSIONS: n-3 PUFA-derived resolvin E1 and its receptor ChemR23 emerge as a key axis in the inhibition of AVS progression and may represent a novel potential therapeutic opportunity to be evaluated in patients with AVS.

20.
J Hepatol ; 73(4): 817-828, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32294533

RESUMO

BACKGROUND & AIMS: Acute-on-chronic liver failure (ACLF) is a newly described syndrome, which develops in patients with acute decompensation of cirrhosis, and is characterized by intense systemic inflammation, multiple organ failures and high short-term mortality. The profile of circulating lipid mediators, which are endogenous signaling molecules that play a major role in inflammation and immunity, is poorly characterized in ACLF. METHODS: In the current study, we assessed the profile of lipid mediators by liquid chromatography coupled to tandem mass spectrometry in plasma from patients with acute decompensation of cirrhosis, with (n = 119) and without (n = 127) ACLF, and from healthy controls (n = 18). Measurements were prospectively repeated in 191 patients with acute decompensation of cirrhosis during a 28-day follow-up period. RESULTS: Fifty-nine lipid mediators (out of 100) were detected in plasma from cirrhotic patients, of which 16 were significantly associated with disease status. Among these, 11 lipid mediators distinguished patients at any stage from healthy controls, whereas 2 lipid mediators (LTE4 and 12-HHT, both derived from arachidonic acid) shaped a minimal plasma fingerprint that discriminated patients with ACLF from those without. Levels of LTE4 distinguished ACLF grade 3 from ACLF grades 1 and 2, followed the clinical course of the disease (increased with worsening and decreased with improvement) and positively correlated with markers of inflammation and non-apoptotic cell death. Moreover, LTE4 together with LXA5 (derived from eicosapentaenoic acid) and EKODE (derived from linoleic acid) were associated with short-term mortality. LXA5 and EKODE formed a signature associated with coagulation and liver failures. CONCLUSION: Taken together, these findings uncover specific lipid mediator profiles associated with disease severity and prognosis in patients with acute decompensation of cirrhosis. LAY SUMMARY: Acute-on-chronic liver failure (ACLF) is characterized by intense systemic inflammation, multiple organ failures and high short-term mortality. In the current study, we assessed the plasma lipid profile of 100 bioactive lipid mediators in healthy controls, patients with decompensated cirrhosis, and those who had developed ACLF. We identified lipid mediator signatures associated with inflammation and non-apoptotic cell death that discriminate disease severity and evolution, short-term mortality and organ failures.

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