Lipoxygenases peroxidise polyunsaturated fatty acids, resulting in oxylipins, which may act pro- or anti-inflammatory. Arachidonate 15-lipoxygenase type B was shown to play a role in the resolution of keratinocyte inflammation and is upregulated in psoriasis. Its murine ortholog, arachidonate 8-lipoxygenase (Alox8), differs in regiospecificity in that it adds molecular oxygen to the 8th and not 15th carbon of arachidonic acid. This study aimed to determine if Alox8 plays a role in the resolution of murine imiquimod-induced psoriasis. Alox8 knockout (KO) mice, which are not commercially available, were generated with a functional KO targeting the enzyme's active site. Untargeted Lipidomics revealed changes in the skin lipidome from both imiquimod-induced psoriasis as well as between wild-type and KO mice. Furthermore, LC-MS/MS revealed a functional KO with reductions in Alox8-specific oxylipins. Lipid peroxidation marker 4-hydroxynonenal was elevated in the epidermis of wild-type mice from imiquimod treatment, however, it was significantly reduced in Alox8 KO mice. Alox8 KO mice exhibited a thickened epidermis, resulting from reduced DNA damage and increased proliferation. Moreover, immune cell infiltration was enhanced in Alox8 KO mice, including a higher abundance of γδ T cells. Elevated cytokine levels of interleukin-17 and -22, accompanied by keratinocyte-produced C-X-C motif chemokine ligand 1, were detected in the skin of Alox8 KO mice. Additionally, cyclooxygenase 2 expression and prostaglandin E2 levels were enhanced in Alox8 KO mice. These data demonstrate an exacerbated and prolonged inflammatory psoriasis phenotype in Alox8 KO mice, implying that Alox8 aids in the resolution of murine psoriasis.

Chronic inflammatory diseases are a significant global burden and are associated with dysregulated resolution of inflammation. Therefore, promoting the process of resolution is a promising therapeutic approach. This study presents the potent anti-inflammatory and pro-resolving effects of a natural product-derived compound called C81. Administration of C81 in a therapeutic window resolved inflammation in the murine imiquimod-induced psoriasis model, and reduced microglial infiltration in a laser-induced choroidal neovascularisation model. Investigations into the underlying mechanisms of C81 identified the DYRK1B/STAT3 axis as a new regulator of inflammatory processes in leukocytes. The inhibition of DYRK1B by C81 resulted in attenuated STAT3 phosphorylation. The depletion of STAT3-regulated gene expression led to the inhibition of leukocyte adhesion and migration due to reduced integrin activation, and in addition to the inhibition of the release of pro-inflammatory mediators such as cytokines and eicosanoids. Importantly, the pro-resolving effects of C81 included the cell type-specific induction of apoptosis in neutrophils and a subsequent increase in efferocytosis. In conclusion, we report the DYRK1B/STAT3 axis as a novel and promising therapeutic target for activating the resolution of inflammation.

Renal fibrosis is the final pathological outcome of chronic kidney disease and is characterized by an excessive accumulation of extracellular matrix (ECM), leading to tissue dysfunction and, ultimately, organ failure. In this study, we investigated the mechanism by which elevated intracellular sphingosine levels in sphingosine kinase 2-deficient (Sphk2-/-) fibroblasts and mice attenuate profibrotic TGF-β signaling. Previously, we demonstrated that higher sphingosine levels suppress the expression of profibrotic factors in TGF-β-treated fibroblasts and a unilateral ureteral obstruction (UUO) mouse model by upregulating SMAD7, an inhibitor of TGF-β/SMAD signaling. Here, we identified miR-21 as a key post-transcriptional regulator of SMAD7 and show that protein kinase C (PKC) inhibition-via sphingosine supplementation, SPHK2 depletion, or pharmacological PKC inhibitors-reduces miR-21 expression. Mechanistically, this occurs through PKC-dependent inhibition of AP1-driven miR-21 transcription. Analysis of human diabetic kidney tissue revealed a significant upregulation of miR-21, contributing to ECM accumulation by suppressing SMAD7 protein expression, corroborating the critical role of miR-21 in renal fibrosis. These findings suggest that targeting the sphingosine-PKC-miR-21-SMAD7 axis may offer a novel therapeutic approach for renal fibrosis.

Parkinson’s disease (PD) involves α-synuclein (αSyn) oligomerization and aggregation, processes facilitated by glycosphingolipids. Defective glycosphingolipid transport and degradation—especially via the lipid-degrading enzyme glucocerebrosidase 1 (GCase, gene GBA1)—aggravate PD and increase dementia risk. Ambroxol is a mucolytic drug and has emerged as a promising add-on therapy for PD since it acts as a chaperone for misfolded GCase, thereby increases the likelihood that mutated and misfolded GCase eludes ER-associated degradation (ERAD) and is transported to its destination, the lysosome. In this study we investigated whether and how ambroxol provided therapeutic benefits for PD irrespective of the GBA1 mutation status. Pink1−/−/SNCAA53T double mutant PD mice were administered ambroxol either via the drinking water (120–150 mg·kg−1·d−1) or via food pellets (75–100 mg·kg−1·d−1) for approximately 6 months. During the treatments mice were observed in IntelliCages; and in motor, sensory and cognitive functions tests. After mice were euthanized, tissues were dissected for protein, lipidomic and metabolomic analyses. We showed that high-dose long-term ambroxol was well tolerated and led to mild behavioral and metabolic improvements but had adverse effects on brain sulfatides, lysosomal functions and mitochondrial cardiolipins. Notably, brain levels of glucosylceramides (GlcCer 16:0) were normalized, while sulfatides (SHexCer) further increased. Western blots revealed a modest reduction of αSyn and phosphorylated αSyn (P-Ser129). IntelliCage assessments showed increased exploratory activity with ambroxol, suggesting reduced bradykinesia, though sensory and motor functions remained unchanged. Lipidomic profiles of mitochondria showed accumulation of HexCer and triglycerides in PD mitochondria, regardless of treatment, while ambroxol led to an additional decline of cardiolipins including the most abundant tetralinoleoyl cardiolipins. In HT22 hippocampal neurons preloaded with αSyn pre-formed fibrils, ambroxol accumulated within lysosomes, increased lysosomal mass and sphingolipid content and promoted lysosomal enzyme release. Collectively, these results suggest that ambroxol confers transient behavioral benefits and modestly reduces αSyn pathology, albeit with potential drawbacks. In addition, its lysosomal accumulation may further disrupt sphingolipid metabolism and impair mitochondrial compensatory mechanisms. Ambroxol-induced lysosomal exocytosis may transiently relieve αSyn burden, but further interventions would be required to ensure αSyn clearance from the brain.

The tumor microenvironment (TME) is a pro-cancerous niche harboring immunosuppressive factors that are secreted by cancer cells and the surrounding cancer-supportive tissue, such as kynurenine, prostaglandin E2 and transforming growth factor β (TGFβ). These factors dampen the activity of cytotoxic lymphocytes like natural killer (NK) cells, allowing evasion of immune cell-mediated killing. To identify small molecules that counteract the immunosuppressive effect of the TME and restore NK cell-mediated cytotoxicity, we developed a phenotypic co-culture assay of cancer cells and primary lymphocytes suitable for medium-throughput screening. We discovered small molecules that restore NK cell-mediated cytotoxicity through diverse mechanisms. The potent TGFβ type I receptor (TGFβR-1) inhibitor, RepSox, stood out as superior to other TGFβR-1 inhibitors due to its ability to abolish the effects of both inhibitory factors used in our setup. This mode of action goes beyond TGFβR-1 inhibition and is related to the simultaneous abrogation of cyclooxygenase 1 (COX1) activity.

Protein S-palmitoylation is the process by which a palmitoyl fatty acid is attached to a cysteine residue of a protein via a thioester bond. A range of methodologies are available for the detection of protein S-palmitoylation. In this study, two methods for the S-palmitoylation of different proteins were compared after metabolic labeling of cells with 15-hexadecynoic acid (15-YNE) to ascertain their relative usefulness. It was hypothesized that labeling cells with a traceable lipid would affect lipid metabolism and the cellular lipidome. In this study, we developed a method to track 15-YNE incorporation into lipids using liquid chromatography high-resolution mass spectrometry (LC-HRMS) as well as protein palmitoylation in the same sample. We observed a time- and concentration-dependent S-palmitoylation of calnexin and succinate dehydrogenase complex flavoprotein subunit A (SDHA) depending on the cell type. The detection of S-palmitoylation with a clickable fluorophore or biotin azide followed by immunoprecipitation is shown to be equally useful. 15-YNE was observed to be incorporated into a wide array of lipid classes during the process, yet it did not appear to modify the overall lipid composition of the cells. In conclusion, we show that 15-YNE is a useful tracer to detect both protein S-palmitoylation and lipid metabolism in the same sample.

BACKGROUND AND AIMS:Eosinophilic esophagitis (EoE) is a chronic, inflammatory, and antigen-driven disease of the esophagus. Total transcriptome data revealed alterations in the endocannabinoid system, in particular, down-regulation of monoacylglycerol lipase (MGL) in biopsies of patients with active EoE. We investigated the consequence of MGL down-regulation in mucosal biopsies of patients, and its implications for EoE development, such as recruitment of eosinophils. METHODS:Levels of MGL substrate 2-arachidonoylglycerol, MGL enzyme activity, and MGL colocalization with epithelial cells were determined in mucosal esophageal biopsies of patients with EoE. Supernatant of human primary esophageal epithelial cells was used to determine eosinophil migration and activation. An inducible mouse model of EoE was used to test MGL inhibition and cannabinoid (CB) receptor antagonism in vivo. RESULTS:MGL expression in esophageal epithelial cells from patients with active EoE is decreased, whereas 2-arachidonoylglycerol is increased compared with control subjects. Inhibition of MGL in epithelial cells leads to a proinflammatory phenotype capable of attracting eosinophils via CB2. Similarly, the EoE mouse model indicates that absence of MGL results in higher eosinophil infiltration. Targeting CB2 reduced the number of infiltrating eosinophils in the esophagi of mice. CONCLUSIONS:This study is the first of its kind to investigate the involvement of altered expression of endocannabinoid system components in EoE, and partly explains recent findings of more inflammatory features post EoE-treatment in cannabis users. Our findings could pave the way for research into alternative treatment options for EoE and call for caution regarding the use of cannabinoids in EoE.

This dataset was generated from a preclinical study that used the relapsing-remitting experimental autoimmune encephalomyelitis (EAE) model in SJL/J mice to examine lipid signalling in neuroinflammation. The study examined how the reference compounds FTY720 (fingolimod, 0.5 mg/kg/day) affected the autotaxin/lysophosphatidic acid (ATX/LPA) axis and related lipid mediators. The mice were divided into three groups: control (no EAE), EAE, and EAE plus fingolimod. Tissue samples were collected from the plasma, cerebellum, hippocampus, and prefrontal cortex, resulting in 26 biological samples. Targeted lipidomics was performed using liquid chromatography-tandem mass spectrometry (LC-MS/MS) to quantify 62 lipid species, including lysophosphatidic acids, ceramides, sphingoid bases, and endocannabinoids. The dataset is provided in both raw and imputed formats, along with comprehensive sample-level metadata.The data are organized into three comma-separated values (CSV) files: (1) the original quantitative lipidomics data matrix with missing values, (2) a log₁₀-transformed imputed dataset with missing values addressed using random forest imputation, and (3) a metadata file detailing the characteristics of the samples, group assignments, and tissue type. Standardized variable naming and detailed metadata facilitate cross-referencing and integration with other datasets.This resource enables comparative analyses of lipid profiles across tissues and treatment groups. It supports statistical and machine learning applications and enables the evaluation of data augmentation strategies, including statistical and generative AI approaches. This dataset can be reused in studies of neuroinflammation, lipid signalling, and biomarker discovery, as well as in the development of methods for computational biology and omics data analysis.

Parkinson’s Disease (PD) is driven by pathological aggregates of alpha-synuclein (αSyn), whose formation is facilitated by impaired glycosphingolipid metabolism via acidic glucocerebrosidase (GCase). We investigated glucosylceramide (GlcCer) accumulation in human, mouse, and cellular PD models. Lipidomic analyses revealed elevated plasma GlcCer, especially GlcCer24:1, and a shift in phosphatidylcholine (PC) species in PD patients. PD patient skin fibroblasts accumulated more GlcCer under lysosomal stress. GlcCer and sulfatides (SHexCer) were increased in Pink1−/−SNCAA53T PD mouse brains, and HT22 neurons exposed to preformed αSyn fibrils accumulated GlcCer and ceramides. GlcCer24:1 enhanced fibril toxicity, but had no direct or indirect effect on G-protein coupled receptors. RNAseq of GlcCer24:1-treated dorsal root ganglion neurons showed upregulation of glycolipid response genes, similar to pathogen-related signaling. These data indicate extracellular GlcCer is elevated in PD and triggers innate immune responses in sensory neurons.

Several oxylipins are potent lipid mediators that regulate diverse aspects of health and disease and whose quantitative analysis by liquid chromatography-mass spectrometry (LC-MS) presents substantial technical challenges. As members of the lipidomics community, we developed technical recommendations to ensure best practices when quantifying oxylipins by LC-MS.

Chronic unpredictable and unavoidable stress is associated with mental health problems such as depression and anxiety, whereas cycles of stress and stress relief strengthen resilience. It has been suggested that increased breakdown of brain endocannabinoids (eCB) promotes a feeling of adversity. To assess the impact of stress on bioactive lipid homeostasis, we analyzed eCB, sphingolipids, and ceramides in seven brain regions and plasma in a mouse model of chronic unpredictable mild stress. Chronic unpredictable mild stress (CUMS) was associated with low levels of anandamide in hippocampus and prefrontal cortex in association with indicators of anxiety (elevated plus maze). Oppositely, CUMS caused elevated levels of sphingosine-1-phosphate (S1P d18:1) and sphinganine-1-phosphate (S1P d18:0) in the midbrain and thalamus, which was associated with readouts of increased stress resilience, i.e., marble burying and struggling in the tail suspension tests. In the periphery, elevated plasma levels of ceramides revealed similarities with human major depression and suggested unfavorable effects of stress on metabolism, but plasma lipids were not associated with body weight, sucrose consumption, or behavioral features of depression or anxiety. The observed brain site-specific lipid changes suggest that the forebrain succumbs to adverse stress effects while the midbrain takes up defensive adjustments.

Background and purposeEndocannabinoids are lipid mediators, which elicit complex biological effects that extend beyond the central nervous system. Tissue concentrations of endocannabinoids increase in atherosclerosis, and for the endocannabinoid N-arachidonoyl-ethanolamine (anandamide, AEA), this has been linked to an anti-inflammatory function. In this study, we set out to determine the anti-inflammatory mechanism of action of AEA, specifically focusing on vascular smooth muscle cells.Experimental approachRNA-sequencing, RT-qPCR, LC-MS/MS, NanoBit, ChIP, microscale thermophoresis, NMR structural footprinting, Gal4 reporter gene assays and loss of function approaches in cell and ex vivo organ culture were used.Key resultsAEA pretreatment attenuated the cytokine-mediated induction of inflammatory gene expression such as CCL2. This effect was also observed in preparations obtained from cannabinoid receptor knockout mice and after pertussis toxin treatment. The anti-inflammatory effect of AEA required preincubation, suggesting an effect through gene induction. AEA increased the expression of the nuclear receptors NR4A1 and NR4A2. Knockdown and knockout of these receptors blocked the AEA-mediated anti-inflammatory effect in cell culture and aortic organ culture, respectively. Conversely, NR4A agonists (CsnB, C-DIM12) attenuated inflammatory gene expression. AEA binds to NR4A, and mutations in NR4A attenuated this effect. The interaction of AEA with NR4A caused recruitment of the nuclear corepressor NCoR1 to the CCL2 promoter, resulting in gene suppression.Conclusion and implicationsBy binding to NR4A, AEA elicits an anti-inflammatory response in vascular smooth muscle cells. NR4A-binding by AEA analogues may represent novel anti-inflammatory agents.

The tumor microenvironment (TME) is a pro-cancerous niche harboring immunosuppressive factors that are secreted by cancer cells and the surrounding cancer-supportive tissue, such as kynurenine, prostaglandin E2 and transforming growth factor β (TGFβ). These factors dampen the activity of cytotoxic lymphocytes like natural killer (NK) cells, allowing evasion of immune cell-mediated killing. To identify small molecules that counteract the immunosuppressive effect of the TME and restore NK cell-mediated cytotoxicity, we developed a phenotypic co-culture assay of cancer cells and primary lymphocytes suitable for medium-throughput screening. We discovered small molecules that restore NK cell-mediated cytotoxicity through diverse mechanisms. The potent TGFβ type I receptor (TGFβR-1) inhibitor, RepSox, stood out as superior to other TGFβR-1 inhibitors due to its ability to abolish the effects of both inhibitory factors used in our setup. This mode of action goes beyond TGFβR-1 inhibition and is related to the simultaneous abrogation of cyclooxygenase 1 (COX1) activity. ### Competing Interest Statement The authors have declared no competing interest.

Lysophosphatidic acids (LPAs) evoke nociception and itch in mice and humans. In this study, we assessed the signaling paths. Hydroxychloroquine was injected intradermally to evoke itch in mice, which evoked an increase of LPAs in the skin and in the thalamus, suggesting that peripheral and central LPA receptors (LPARs) were involved in HCQ-evoked pruriception. To unravel the signaling paths, we assessed the localization of candidate genes and itching behavior in knockout models addressing LPAR5, LPAR2, autotaxin/ENPP2 and the lysophospholipid phosphatases, as well as the plasticity-related genes Prg1/LPPR4 and Prg2/LPPR3. LacZ reporter studies and RNAscope revealed LPAR5 in neurons of the dorsal root ganglia (DRGs) and in skin keratinocytes, LPAR2 in cortical and thalamic neurons, and Prg1 in neuronal structures of the dorsal horn, thalamus and SSC. HCQ-evoked scratching behavior was reduced in sensory neuron-specific Advillin-LPAR5−/− mice (peripheral) but increased in LPAR2−/− and Prg1−/− mice (central), and it was not affected by deficiency of glial autotaxin (GFAP-ENPP2−/−) or Prg2 (PRG2−/−). Heat and mechanical nociception were not affected by any of the genotypes. The behavior suggested that HCQ-mediated itch involves the activation of peripheral LPAR5, which was supported by reduced itch upon treatment with an LPAR5 antagonist and autotaxin inhibitor. Further, HCQ-evoked calcium fluxes were reduced in primary sensory neurons of Advillin-LPAR5−/− mice. The results suggest that LPA-mediated itch is primarily mediated via peripheral LPAR5, suggesting that a topical LPAR5 blocker might suppress “non-histaminergic” itch.

Background: Chemotherapy-induced peripheral neuropathy (CIPN) is a serious therapy-limiting side effect of commonly used anticancer drugs. Previous studies suggest that lipids may play a role in CIPN. Therefore, the present study aimed to identify the particular types of lipids that are regulated as a consequence of paclitaxel administration and may be associated with the occurrence of post-therapeutic neuropathy. Methods: High-resolution mass spectrometry lipidomics was applied to quantify d=255 different lipid mediators in the blood of n=31 patients drawn before and after paclitaxel therapy for breast cancer treatment. A variety of supervised statistical and machine-learning methods was applied to identify lipids that were regulated during paclitaxel therapy or differed among patients with and without post-therapeutic neuropathy. Results: Twenty-seven lipids were identified that carried relevant information to train machine learning algorithms to identify, in new cases, whether a blood sample was drawn before or after paclitaxel therapy with a median balanced accuracy of up to 90%. One of the top hits, sphinganine-1-phosphate (SA1P), was found to induce calcium transients in sensory neurons via the transient receptor potential vanilloid 1 (TRPV1) channel and sphingosine-1-phosphate receptors.SA1P also showed different blood concentrations between patients with and without neuropathy. Conclusions: Present findings suggest a role for sphinganine-1-phosphate in paclitaxel-induced biological changes associated with neuropathic side effects. The identified SA1P, through its receptors, may provide a potential drug target for co-therapy with paclitaxel to reduce one of its major and therapy-limiting side effects. Funding: This work was supported by the Deutsche Forschungsgemeinschaft (German Research Foundation, DFG, Grants SFB1039 A09 and Z01) and by the Fraunhofer Foundation Project: Neuropathic Pain as well as the Fraunhofer Cluster of Excellence for Immune-Mediated Diseases (CIMD). This work was also supported by the Leistungszentrum Innovative Therapeutics (TheraNova) funded by the Fraunhofer Society and the Hessian Ministry of Science and Arts. Jörn Lötsch was supported by the Deutsche Forschungsgemeinschaft (DFG LO 612/16-1).

Knowledge of the molecular pathogenesis of acute myeloid leukemia has advanced in recent years. Despite novel treatment options, acute myeloid leukemia remains a survival challenge for elderly patients. We have recently shown that the triphosphohydrolase SAMHD1 is one of the factors determining resistance to Ara-C treatment. Here, we designed and tested novel and simpler virus-like particles incorporating the lentiviral protein Vpx to efficiently and transiently degrade SAMHD1 and increase the efficacy of Ara-C treatment. The addition of minute amounts of lentiviral Rev protein during production enhanced the generation of virus-like particles. In addition, we found that our 2nd generation of virus-like particles efficiently targeted and degraded SAMHD1 in AML cell lines with high levels of SAMHD1, thereby increasing Ara-CTP levels and response to Ara-C treatment. Primary AML blasts were generally less responsive to VLP treatment. In summary, we have been able to generate novel and simpler virus-like particles that can efficiently deliver Vpx to target cells.

Nerve injury causes neuropathic pain and multilevel nerve barrier disruption. Nerve barriers consist of perineurial, endothelial and myelin barriers. So far, it is unclear whether resealing nerve barriers fosters pain resolution and recovery. To this end, we analysed the nerve barrier property portfolio, pain behaviour battery and lipidomics for precursors of specialized pro-resolving meditators (SPMs) and their receptors in chronic constriction injury of the rat sciatic nerve to identify targets for pain resolution by resealing the selected nerve barriers. Of the three nerve barriers—perineurium, capillaries and myelin—only capillary tightness specifically against larger molecules, such as fibrinogen, recuperated with pain resolution. Fibrinogen immunoreactivity was elevated in rats not only at the time of neuropathic pain but also in nerve biopsies from patients with (but not without) painful polyneuropathy, indicating that sealing of the vascular barrier might be a novel approach in pain treatment. Hydroxyeicosatetraenoic acid (15R-HETE), a precursor of aspirin-triggered lipoxin A4, was specifically upregulated at the beginning of pain resolution. Repeated local application of resolvin D1-laden nanoparticles or Fpr2 agonists sex-independently resulted in accelerated pain resolution and fibrinogen removal. Clearing macrophages (Cd206) were boosted and fibrinolytic pathways (Plat) were induced, while inflammation (Tnfα) and inflammasomes (Nlrp3) were unaffected by this treatment. Blocking TAM receptors (Tyro3, Axl and Mer) and tyrosine kinase receptors linking haemostasis and inflammation completely inhibited all the effects. In summary, nanoparticles can be used as transporters for fleeting lipids, such as SPMs, and therefore expand the array of possible therapeutic agents. Thus, the Fpr2–Cd206–TAM receptor axis may be a suitable target for strengthening the capillary barrier, removing endoneurial fibrinogen and boosting pain resolution in patients with chronic neuropathic pain.

Perceived stress is thought to contribute to the pathogenesis of metabolic, vascular, mental, and immune diseases, with different susceptibilities in women and men. The present study investigated if and how perceived stress and/or demographic variables, including sex, age, body mass index, regular prescription drugs, occasional analgesics, or dietary supplements, manifested in plasma lipidomic profiles obtained by targeted and untargeted mass spectrometry analyses. The study included 217 healthy women and 108 healthy men, aged 18-68 yr, who were recruited in a 2:1 female:male ratio to account for women with/without contraceptives. As expected, dehydroepiandrosterone sulfate (DHEAS) and ceramides were higher in men than women, and DHEAS decreased with age, whereas ceramides increased. Contrary to expectations, neither DHEAS nor ceramides were associated with perceived stress [Perceived Stress Questionnaire with 30 questions (PSQ30 questionnaire)], which was, however, associated with BMI in men but not in women. None of the lipid species or classes showed a similar "age × sex × BMI" interaction, but the endocannabinoid palmitoylethanolamide (PEA) correlated with body mass index (BMI) and hypertension. Independent of perceived stress, lysophosphatidylcholines (LPCs) were lower in women than men, whereas LPC metabolites, lysophosphatidic acids (LPAs), were higher in women. The LPA:LPC ratio was particularly high in women using oral contraceptives, suggesting a strong hormone-induced extracellular conversion of LPCs to LPAs, which is catalyzed by the phospholipase D, autotaxin. The results reveal complex sex differences in perceived stress and lipidomic profiles, the latter being exacerbated by contraceptive use, but perceived stress and lipids were not directly correlated.NEW & NOTEWORTHY Perceived stress (PSQ questionnaire) depends on the interaction of "sex × age × BMI." Plasma lipid profiles depend on sex and age. Natural sex differences are exacerbated by the use of contraceptives. Perceived stress is not correlated with specific plasma lipids or lipidomic profiles. Women have high LPA:LPC ratios in association with high levels of autotaxin.

The molecular mechanisms by which worm parasites evade host immunity are incompletely understood. In a mouse model of intestinal helminth infection using Heligmosomoides polygyrus bakeri (Hpb), we show that helminthic glutamate dehydrogenase (heGDH) drives parasite chronicity by suppressing macrophage-mediated host defense. Combining RNA-seq, ChIP-seq, and targeted lipidomics, we identify prostaglandin E2 (PGE2) as a major immune regulatory mechanism of heGDH. The induction of PGE2 and other immunoregulatory factors, including IL-12 family cytokines and indoleamine 2,3-dioxygenase 1, by heGDH required p300-mediated histone acetylation, whereas the enzyme's catalytic activity suppressed the synthesis of type 2-promoting leukotrienes by macrophages via 2-hydroxyglutarate. By contrast, the induction of immunoregulatory factors involved the heGDH N terminus by potentially mediating interactions with cellular targets (CD64 and GPNMB) identified by proteomics. Type 2 cytokines counteracted suppressive effects of heGDH on host defense, indicating that type 2 immunity can limit helminth-driven immune evasion. Thus, helminths harness a ubiquitous metabolic enzyme to epigenetically target type 2 macrophage activation and establish chronicity.