High-mannose glycans from Schistosoma mansoni eggs are important for priming of Th2 responses via Dectin-2 and prostaglandin E2.

The parasitic helminth Schistosoma mansoni is a potent inducer of type 2 immune responses by stimulating dendritic cells (DCs) to prime T helper 2 (Th2) responses. We previously found that S. mansoni soluble egg antigens (SEA) promote the synthesis of Prostaglandin E2 (PGE2) by DCs through ERK-dependent signaling via Dectin-1 and Dectin-2 that subsequently induces OX40L expression, licensing them for Th2 priming, yet the ligands present in SEA involved in driving this response and whether specific targeting of PGE2 synthesis by DCs could affect Th2 polarization are unknown. We here show that the ability of SEA to bind Dectin-2 and drive ERK phosphorylation, PGE2 synthesis, OX40L expression, and Th2 polarization is impaired upon cleavage of high-mannose glycans by Endoglycosidase H treatment. This identifies high-mannose glycans present on glycoproteins in SEA as important drivers of this signaling axis. Moreover, we find that OX40L expression and Th2 induction are abrogated when microsomal prostaglandin E synthase-1 (mPGES) is selectively inhibited, but not when a general COX-1/2 inhibitor is used. This shows that the de novo synthesis of PGE2 is vital for the Th2 priming function of SEA-stimulated DCs as well as points to the potential existence of other COX-dependent lipid mediators that antagonize PGE2-driven Th2 polarization. Lastly, specific PGE2 inhibition following immunization with S. mansoni eggs dampened the egg-specific Th cell response. In summary, our findings provide new insights in the molecular mechanisms underpinning Th2 induction by S. mansoni and identify druggable targets for potential control of helminth driven-Th2 responses.

DHCR24 inhibitor SH42 increases desmosterol without preventing atherosclerosis development in mice.

The liver X receptor (LXR) is considered a therapeutic target for atherosclerosis treatment, but synthetic LXR agonists generally also cause hepatic steatosis and hypertriglyceridemia. Desmosterol, a final intermediate in cholesterol biosynthesis, has been identified as a selective LXR ligand that suppresses inflammation without inducing lipogenesis. Δ24-Dehydrocholesterol reductase (DHCR24) converts desmosterol into cholesterol, and we previously showed that the DHCR24 inhibitor SH42 increases desmosterol to activate LXR and attenuate experimental peritonitis and metabolic dysfunction-associated steatotic liver disease. Here, we aimed to evaluate the effect of SH42 on atherosclerosis development in APOE∗3-Leiden.CETP mice and low-density lipoproteins (LDL) receptor knockout mice, models for lipid- and inflammation-driven atherosclerosis, respectively. In both models, SH42 increased desmosterol without affecting plasma lipids. While reducing liver lipids in APOE∗3-Leiden.CETP mice, and regulating populations of circulating monocytes in LDL receptor knockout mice, SH42 did not attenuate atherosclerosis in either model.

A cell-free nutrient-supplemented perfusate allows four-day ex vivo metabolic preservation of human kidneys.

The growing disparity between the demand for transplants and the available donor supply, coupled with an aging donor population and increasing prevalence of chronic diseases, highlights the urgent need for the development of platforms enabling reconditioning, repair, and regeneration of deceased donor organs. This necessitates the ability to preserve metabolically active kidneys ex vivo for days. However, current kidney normothermic machine perfusion (NMP) approaches allow metabolic preservation only for hours. Here we show that human kidneys discarded for transplantation can be preserved in a metabolically active state up to 4 days when perfused with a cell-free perfusate supplemented with TCA cycle intermediates at subnormothermia (25 °C). Using spatially resolved isotope tracing we demonstrate preserved metabolic fluxes in the kidney microenvironment up to Day 4 of perfusion. Beyond Day 4, significant changes were observed in renal cell populations through spatial lipidomics, and increases in injury markers such as LDH, NGAL and oxidized lipids. Finally, we demonstrate that perfused kidneys maintain functional parameters up to Day 4. Collectively, these findings provide evidence that this approach enables metabolic and functional preservation of human kidneys over multiple days, establishing a solid foundation for future clinical investigations.

mARC1 in MASLD: Modulation of lipid accumulation in human hepatocytes and adipocytes.

BACKGROUND: Mutations in the gene MTARC1 (mitochondrial amidoxime-reducing component 1) protect carriers from metabolic dysfunction-associated steatohepatitis (MASH) and cirrhosis. MTARC1 encodes the mARC1 enzyme, which is localized to the mitochondria and has no known MASH-relevant molecular function. Our studies aimed to expand on the published human genetic mARC1 data and to observe the molecular effects of mARC1 modulation in preclinical MASH models. METHODS AND RESULTS: We identified a novel human structural variant deletion in MTARC1, which is associated with various biomarkers of liver health, including alanine aminotransferase levels. Phenome-wide Mendelian Randomization analyses additionally identified novel putatively causal associations between MTARC1 expression, and esophageal varices and cardiorespiratory traits. We observed that protective MTARC1 variants decreased protein accumulation in in vitro overexpression systems and used genetic tools to study mARC1 depletion in relevant human and mouse systems. Hepatocyte mARC1 knockdown in murine MASH models reduced body weight, liver steatosis, oxidative stress, cell death, and fibrogenesis markers. mARC1 siRNA treatment and overexpression modulated lipid accumulation and cell death consistently in primary human hepatocytes, hepatocyte cell lines, and primary human adipocytes. mARC1 depletion affected the accumulation of distinct lipid species and the expression of inflammatory and mitochondrial pathway genes/proteins in both in vitro and in vivo models. CONCLUSIONS: Depleting hepatocyte mARC1 improved metabolic dysfunction-associated steatotic liver disease-related outcomes. Given the functional role of mARC1 in human adipocyte lipid accumulation, systemic targeting of mARC1 should be considered when designing mARC1 therapies. Our data point to plasma lipid biomarkers predictive of mARC1 abundance, such as Ceramide 22:1. We propose future areas of study to describe the precise molecular function of mARC1, including lipid trafficking and subcellular location within or around the mitochondria and endoplasmic reticulum.

Tandem Mass Spectrometry across Platforms.

PubChem serves as a comprehensive repository, housing over 100 million unique chemical structures representing the breadth of our chemical knowledge across numerous fields including metabolism, pharmaceuticals, toxicology, cosmetics, agriculture, and many more. Rapid identification of these small molecules increasingly relies on electrospray ionization (ESI) paired with tandem mass spectrometry (MS/MS), particularly by comparison to genuine standard MS/MS data sets. Despite its widespread application, achieving consistency in MS/MS data across various analytical platforms remains an unaddressed concern. This study evaluated MS/MS data derived from one hundred molecular standards utilizing instruments from five manufacturers, inclusive of quadrupole time-of-flight (QTOF) and quadrupole orbitrap "exactive" (QE) mass spectrometers by Agilent (QTOF), Bruker (QTOF), SCIEX (QTOF), Waters (QTOF), and Thermo QE. We assessed fragment ion variations at multiple collisional energies (0, 10, 20, and 40 eV) using the cosine scoring algorithm for comparisons and the number of fragments observed. A parallel visual analysis of the MS/MS spectra across instruments was conducted, consistent with a standard procedure that is used to circumvent the still prevalent issue of mischaracterizations as shown for dimethyl sphingosine and C20 sphingosine. Our analysis revealed a notable consistency in MS/MS data and identifications, with fragment ions' m/z values exhibiting the highest concordance between instrument platforms at 20 eV, the other collisional energies (0, 10, and 40 eV) were significantly lower. While moving toward a standardized ESI MS/MS protocol is required for dependable molecular characterization, our results also underscore the continued importance of corroborating MS/MS data against standards to ensure accurate identifications. Our findings suggest that ESI MS/MS manufacturers, akin to the established norms for gas chromatography mass spectrometry instruments, should standardize the collision energy at 20 eV across different instrument platforms.

Distinct intestinal microbial signatures linked to accelerated systemic and intestinal biological aging.

BACKGROUND: People living with HIV (PLWH), even when viral replication is controlled through antiretroviral therapy (ART), experience persistent inflammation. This inflammation is partly attributed to intestinal microbial dysbiosis and translocation, which may lead to non-AIDS-related aging-associated comorbidities. The extent to which living with HIV - influenced by the infection itself, ART usage, sexual orientation, or other associated factors - affects the biological age of the intestines is unclear. Furthermore, the role of microbial dysbiosis and translocation in the biological aging of PLWH remains to be elucidated. To investigate these uncertainties, we used a systems biology approach, analyzing colon and ileal biopsies, blood samples, and stool specimens from PLWH on ART and people living without HIV (PLWoH) as controls. RESULTS: PLWH exhibit accelerated biological aging in the colon, ileum, and blood, as measured by various epigenetic aging clocks, compared to PLWoH. Investigating the relationship between microbial translocation and biological aging, PLWH had decreased levels of tight junction proteins in the intestines, along with increased microbial translocation. This intestinal permeability correlated with faster biological aging and increased inflammation. When investigating the relationship between microbial dysbiosis and biological aging, the intestines of PLWH had higher abundance of specific pro-inflammatory bacteria, such as Catenibacterium and Prevotella. These bacteria correlated with accelerated biological aging. Conversely, the intestines of PLWH had lower abundance of bacteria known for producing the anti-inflammatory short-chain fatty acids, such as Subdoligranulum and Erysipelotrichaceae, and these bacteria were associated with slower biological aging. Correlation networks revealed significant links between specific microbial genera in the colon and ileum (but not in feces), increased aging, a rise in pro-inflammatory microbe-related metabolites (e.g., those in the tryptophan metabolism pathway), and a decrease in anti-inflammatory metabolites like hippuric acid. CONCLUSIONS: We identified specific microbial compositions and microbiota-related metabolic pathways that are intertwined with intestinal and systemic biological aging. This microbial signature of biological aging is likely reflecting various factors including the HIV infection itself, ART usage, sexual orientation, and other aspects associated with living with HIV. A deeper understanding of the mechanisms underlying these connections could offer potential strategies to mitigate accelerated aging and its associated health complications. Video Abstract.

A polyphenol-rich plant extract prevents hypercholesterolemia and modulates gut microbiota in western diet-fed mice.

Introduction: Totum-070 is a combination of five plant extracts enriched in polyphenols to target hypercholesterolemia, one of the main risk factors for cardiovascular diseases. The aim of this study was to investigate the effects of Totum-070 on cholesterol levels in an animal model of diet-induced hypercholesterolemia. Methods: C57BL/6JOlaHsd male mice were fed a Western diet and received Totum-070, or not, by daily gavage (1g/kg and 3g/kg body weight) for 6 weeks. Results: The Western diet induced obesity, fat accumulation, hepatic steatosis and increased plasma cholesterol compared with the control group. All these metabolic perturbations were alleviated by Totum-070 supplementation in a dose-dependent manner. Lipid excretion in feces was higher in mice supplemented with Totum-070, suggesting inhibition of intestinal lipid absorption. Totum-070 also increased the fecal concentration of short chain fatty acids, demonstrating a direct effect on intestinal microbiota. Discussion: The characterization of fecal microbiota by 16S amplicon sequencing showed that Totum-070 supplementation modulated the dysbiosis associated with metabolic disorders. Specifically, Totum-070 increased the relative abundance of Muribaculum (a beneficial bacterium) and reduced that of Lactococcus (a genus positively correlated with increased plasma cholesterol level). Together, these findings indicate that the cholesterol-lowering effect of Totum-070 bioactive molecules could be mediated through multiple actions on the intestine and gut microbiota.

Spatially and temporally resolved metabolome of the human oral cavity.

Saliva is a complex bodily fluid composed of secretions by major and minor salivary glands. Salivary glands and their secretions are known to be unevenly distributed in the human oral cavity. Moreover, saliva flow rate and composition vary across locations and time of the day. This remarkable heterogeneity of salivary secretions suggests that different subtypes of saliva fulfill different functions. By coupling a non-invasive and facile collection method with comprehensive metabolomic profiling, we investigated the spatial and temporal distributions of salivary components. We identified location-specific metabolite profiles, novel oscillating metabolites, and location-specific diurnal patterns. In summary, our study paves the way for a deeper and more comprehensive understanding of the complex dynamics and functionalities of the salivary metabolome and its integration in multi-omics studies related to oral and systemic (patho-)physiology.

Arachidonic acid-derived lipid mediators in multiple sclerosis pathogenesis: fueling or dampening disease progression?

BACKGROUND: Multiple sclerosis (MS) is a chronic autoimmune disease of the central nervous system (CNS), characterized by neuroinflammation, demyelination, and neurodegeneration. Considering the increasing prevalence among young adults worldwide and the disabling phenotype of the disease, a deeper understanding of the complexity of the disease pathogenesis is needed to ultimately improve diagnosis and personalize treatment opportunities. Recent findings suggest that bioactive lipid mediators (LM) derived from ω-3/-6 polyunsaturated fatty acids (PUFA), also termed eicosanoids, may contribute to MS pathogenesis. For example, disturbances in LM profiles and especially those derived from the ω-6 PUFA arachidonic acid (AA) have been reported in people with MS (PwMS), where they may contribute to the chronicity of neuroinflammatory processes. Moreover, we have previously shown that certain AA-derived LMs also associated with neurodegenerative processes in PwMS, suggesting that AA-derived LMs are involved in more pathological events than solely neuroinflammation. Yet, to date, a comprehensive overview of the contribution of these LMs to MS-associated pathological processes remains elusive. MAIN BODY: This review summarizes and critically evaluates the current body of literature on the eicosanoid biosynthetic pathway and its contribution to key pathological hallmarks of MS during different disease stages. Various parts of the eicosanoid pathway are highlighted, namely, the prostanoid, leukotriene, and hydroxyeicosatetraenoic acids (HETEs) biochemical routes that include specific enzymes of the cyclooxygenases (COXs) and lipoxygenases (LOX) families. In addition, cellular sources of LMs and their potential target cells based on receptor expression profiles will be discussed in the context of MS. Finally, we propose novel therapeutic approaches based on eicosanoid pathway and/or receptor modulation to ultimately target chronic neuroinflammation, demyelination and neurodegeneration in MS. SHORT CONCLUSION: The eicosanoid pathway is intrinsically linked to specific aspects of MS pathogenesis. Therefore, we propose that novel intervention strategies, with the aim of accurately modulating the eicosanoid pathway towards the biosynthesis of beneficial LMs, can potentially contribute to more patient- and MS subtype-specific treatment opportunities to combat MS.

Ethnic Disparities in Lipid Metabolism and Clinical Outcomes between Dutch South Asians and Dutch White Caucasians with Type 2 Diabetes Mellitus.

Type 2 diabetes mellitus (T2DM) poses a higher risk for complications in South Asian individuals compared to other ethnic groups. To shed light on potential mediating factors, we investigated lipidomic changes in plasma of Dutch South Asians (DSA) and Dutch white Caucasians (DwC) with and without T2DM and explore their associations with clinical features. Using a targeted quantitative lipidomics platform, monitoring over 1000 lipids across 17 classes, along with 1H NMR based lipoprotein analysis, we studied 51 healthy participants (21 DSA, 30 DwC) and 92 T2DM patients (47 DSA, 45 DwC) from the MAGNetic resonance Assessment of VICTOza efficacy in the Regression of cardiovascular dysfunction in type 2 dIAbetes mellitus (MAGNA VICTORIA) study. This comprehensive mapping of the circulating lipidome allowed us to identify relevant lipid modules through unbiased weighted correlation network analysis, as well as disease and ethnicity related key mediatory lipids. Significant differences in lipidomic profiles, encompassing various lipid classes and species, were observed between T2DM patients and healthy controls in both the DSA and DwC populations. Our analyses revealed that healthy DSA, but not DwC, controls already exhibited a lipid profile prone to develop T2DM. Particularly, in DSA-T2DM patients, specific lipid changes correlated with clinical features, particularly diacylglycerols (DGs), showing significant associations with glycemic control and renal function. Our findings highlight an ethnic distinction in lipid modules influencing clinical outcomes in renal health. We discover distinctive ethnic disparities of the circulating lipidome and identify ethnicity-specific lipid markers. Jointly, our discoveries show great potential as personalized biomarkers for the assessment of glycemic control and renal function in DSA-T2DM individuals.

Serum bile acids associate with liver volume in polycystic liver disease and decrease upon treatment with lanreotide.

BACKGROUND: Polycystic liver disease (PLD) is a common extrarenal manifestation of autosomal dominant polycystic kidney disease (ADPKD). Bile acids may play a role in PLD pathogenesis. We performed a post-hoc exploratory analysis of bile acids in ADPKD patients, who had participated in a trial on the effect of a somatostatin analogue. Our hypothesis was that serum bile acid levels increase in PLD, and that lanreotide, which reduces liver growth, may also reduce bile acid levels. Furthermore, in PLD, urinary excretion of bile acids might contribute to renal disease. METHODS: With liquid chromatography-mass spectrometry, 11 bile acids in serum and 6 in urine were quantified in 105 PLD ADPKD patients and 52 age-, sex-, mutation- and eGFR-matched non-PLD ADPKD patients. Sampling was done at baseline and after 120 weeks of either lanreotide or standard care. RESULTS: Baseline serum levels of taurine- and glycine-conjugated bile acids were higher in patients with larger livers. In PLD patients, multiple bile acids decreased upon treatment with lanreotide but remained stable in untreated subjects. Changes over time did not correlate with changes in liver volume. Urine bile acid levels did not change and did not correlate with renal disease progression. CONCLUSION: In ADPKD patients with PLD, baseline serum bile acids were associated with liver volume. Lanreotide reduced bile acid levels and has previously been shown to reduce liver volume. However, in this study, the decrease in bile acids was not associated with the change in liver volume.

Totum-070, a Polyphenol-Rich Plant Extract, Prevents Hypercholesterolemia in High-Fat Diet-Fed Hamsters by Inhibiting Intestinal Cholesterol Absorption.

Atherosclerotic cardiovascular disease is the leading cause of mortality worldwide, and hypercholesterolemia is a central risk factor for atherosclerosis. This study evaluated the effects of Totum-070, a plant-based polyphenol-rich supplement, in hamsters with high-fat diet (HFD)-induced dyslipidemia. The molecular mechanisms of action were explored using human Caco2 enterocytes. Totum-070 supplementation reduced the total cholesterol (-41%), non-HDL cholesterol (-47%), and triglycerides (-46%) in a dose-dependent manner, compared with HFD. HFD-induced hepatic steatosis was also significantly decreased by Totum-070, an effect associated with the reduction in various lipid and inflammatory gene expression. Upon challenging with olive oil gavage, the post-prandial triglyceride levels were strongly reduced. The sterol excretion in the feces was increased in the HFD-Totum-070 groups compared with the HFD group and associated with reduction of intestinal cholesterol absorption. These effects were confirmed in the Caco2 cells, where incubation with Totum-070 inhibited cholesterol uptake and apolipoprotein B secretion. Furthermore, a microbiota composition analysis revealed a strong effect of Totum-070 on the alpha and beta diversity of bacterial species and a significant decrease in the Firmicutes to Bacteroidetes ratio. Altogether, our findings indicate that Totum-070 lowers hypercholesterolemia by reducing intestinal cholesterol absorption, suggesting that its use as dietary supplement may be explored as a new preventive strategy for cardiovascular diseases.

Distinct Intestinal Microbial Signatures Linked to Accelerated Biological Aging in People with HIV.

Background: People with HIV (PWH), even with controlled viral replication through antiretroviral therapy (ART), experience persistent inflammation. This is partly due to intestinal microbial dysbiosis and translocation. Such ongoing inflammation may lead to the development of non-AIDS-related aging-associated comorbidities. However, there remains uncertainty regarding whether HIV affects the biological age of the intestines and whether microbial dysbiosis and translocation influence the biological aging process in PWH on ART. To fill this knowledge gap, we utilized a systems biology approach, analyzing colon and ileal biopsies, blood samples, and stool specimens from PWH on ART and their matched HIV-negative counterparts. Results: Despite having similar chronological ages, PWH on ART exhibit accelerated biological aging in the colon, ileum, and blood, as measured by various epigenetic aging clocks, compared to HIV-negative controls. Investigating the relationship between microbial translocation and biological aging, PWH on ART had decreased levels of tight junction proteins in the colon and ileum, along with increased microbial translocation. This increased intestinal permeability correlated with faster intestinal and systemic biological aging, as well as increased systemic inflammation. When investigating the relationship between microbial dysbiosis and biological aging, the intestines of PWH on ART had higher abundance of specific pro-inflammatory bacterial genera, such as Catenibacterium and Prevotella. These bacteria significantly correlated with accelerated local and systemic biological aging. Conversely, the intestines of PWH on ART had lower abundance of bacterial genera known for producing short-chain fatty acids and exhibiting anti-inflammatory properties, such as Subdoligranulum and Erysipelotrichaceae, and these bacteria taxa were associated with slower biological aging. Correlation networks revealed significant links between specific microbial genera in the colon and ileum (but not in feces), increased aging, a rise in pro-inflammatory microbial-related metabolites (e.g., those in the tryptophan metabolism pathway), and a decrease in anti-inflammatory metabolites like hippuric acid and oleic acid. Conclusions: We identified a specific microbial composition and microbiome-related metabolic pathways that are intertwined with both intestinal and systemic biological aging in PWH on ART. A deeper understanding of the mechanisms underlying these connections could potentially offer strategies to counteract premature aging and its associated health complications in PWH.

Impaired gut microbiota-mediated short-chain fatty acid production precedes morbidity and mortality in people with HIV.

Antiretroviral therapy (ART) has dramatically lengthened lifespan among people with HIV (PWH), but this population experiences heightened rates of inflammation-related comorbidities. HIV-associated inflammation is linked with an altered microbiome; whether such alterations precede inflammation-related comorbidities or occur as their consequence remains unknown. We find that ART-treated PWH exhibit depletion of gut-resident bacteria that produce short-chain fatty acids (SCFAs)-crucial microbial metabolites with anti-inflammatory properties. Prior reports establish that fecal SCFA concentrations are not depleted in PWH. We find that gut-microbiota-mediated SCFA production capacity is better reflected in serum than in feces and that PWH exhibit reduced serum SCFA, which associates with inflammatory markers. Leveraging stool and serum samples collected prior to comorbidity onset, we find that HIV-specific microbiome alterations precede morbidity and mortality in ART-treated PWH. Among these microbiome alterations, reduced microbiome-mediated conversion of lactate to propionate precedes mortality in PWH. Thus, gut microbial fiber/lactate conversion to SCFAs may modulate HIV-associated comorbidity risk.

Fatty acid desaturation and lipoxygenase pathways support trained immunity.

Infections and vaccines can induce enhanced long-term responses in innate immune cells, establishing an innate immunological memory termed trained immunity. Here, we show that monocytes with a trained immunity phenotype, due to exposure to the Bacillus Calmette-Guérin (BCG) vaccine, are characterized by an increased biosynthesis of different lipid mediators (LM) derived from long-chain polyunsaturated fatty acids (PUFA). Pharmacological and genetic approaches show that long-chain PUFA synthesis and lipoxygenase-derived LM are essential for the BCG-induced trained immunity responses of human monocytes. Furthermore, products of 12-lipoxygenase activity increase in monocytes of healthy individuals after BCG vaccination. Grasping the underscoring lipid metabolic pathways contributes to our understanding of trained immunity and may help to identify therapeutic tools and targets for the modulation of innate immune responses.

The two enantiomers of 2-hydroxyglutarate differentially regulate cytotoxic T cell function.

2-Hydroxyglutarate (2HG) is a byproduct of the tricarboxylic acid (TCA) cycle and is readily detected in the tissues of healthy individuals. 2HG is found in two enantiomeric forms: S-2HG and R-2HG. Here, we investigate the differential roles of these two enantiomers in cluster of differentiation (CD)8+ T cell biology, where we find they have highly divergent effects on proliferation, differentiation, and T cell function. We show here an analysis of structural determinants that likely underlie these differential effects on specific α-ketoglutarate (αKG)-dependent enzymes. Treatment of CD8+ T cells with exogenous S-2HG, but not R-2HG, increased CD8+ T cell fitness in vivo and enhanced anti-tumor activity. These data show that S-2HG and R-2HG should be considered as two distinct and important actors in the regulation of T cell function.

A novel polyphenol-rich combination of 5 plant extracts prevents high-fat diet-induced body weight gain by regulating intestinal macronutrient absorption in mice.

Global prevalence of obesity and type 2 diabetes are rapidly increasing to pandemic proportions. A novel supplement composed of 5 plant extracts from olive leaf, bilberry, artichoke, chrysanthellum, and black pepper was designed to prevent type 2 diabetes development in people at risk. It was previously shown to improve body weight and glucose control in preclinical rodent models, with these effects being accompanied by increased fecal energy excretion and in vitro inhibition of several digestive enzymes. Thus, we hypothesized that, in mice fed a high-fat diet (HFD), a single dose of this botanical supplementation would decrease the responses to oral fat and carbohydrate tolerance tests, and that chronic supplementation would result in increased fecal triglyceride content. We showed that acute administration in HFD-fed mice (1.452 g/kg body weight) markedly reduced circulating triglycerides following an oral lipid gavage, whereas glycemic responses to various carbohydrate tests were only mildly affected. When incorporated into the food (2.5%) of HFD-fed mice, chronic supplementation prevented body weight gain and improved glucose homeostasis and lipid tolerance. Fecal free fatty acid content, but not triglyceride, was significantly increased in supplemented animals, suggesting reduced lipid absorption in the digestive tract. Congruently, this botanical supplementation downregulated several genes associated with fatty acid transport whose expression was increased by HFD, principally in the jejunum. This study provides novel insights as for the mode of action behind the antiobesity effect of this plant-based supplementation, in HFD-fed mice.

Metabolomic and Lipidomic Analysis of the Colorectal Adenocarcinoma Cell Line HT29 in Hypoxia and Reoxygenation.

The poor availability of oxygen and nutrients in malignant tumors drives the activation of various molecular responses and metabolic reprogramming in cancer cells. Hypoxic tumor regions often exhibit resistance to chemotherapy and radiotherapy. One approach to enhance cancer therapy is to indirectly increase tumor oxygen availability through targeted metabolic reprogramming. Thus, understanding the underlying metabolic changes occurring during hypoxia and reoxygenation is crucial for improving therapy efficacy. In this study, we utilized the HT29 colorectal adenocarcinoma cell line as a hypoxia-reoxygenation model to investigate central carbon and lipid metabolism. Through quantitative NMR spectroscopy and flow injection analysis - differential mobility spectroscopy-tandem mass spectrometry (FIA-DMS-MS/MS) analysis, we observed alterations in components of mitochondrial metabolism, redox status, specific lipid classes, and structural characteristics of lipids during hypoxia and up to 24 h of reoxygenation. These findings contribute to our understanding of the metabolic changes occurring during reoxygenation and provide the basis for functional studies aimed at metabolic pathways in cancer cells.

Association of Arachidonic Acid-Derived Lipid Mediators With Disease Severity in Patients With Relapsing and Progressive Multiple Sclerosis.

BACKGROUND AND OBJECTIVES: Excessive activation of certain lipid mediator (LM) pathways plays a role in the complex pathogenesis of multiple sclerosis (MS). However, the relationship between bioactive LMs and different aspects of CNS-related pathophysiologic processes remains largely unknown. Therefore, in this study, we assessed the association of bioactive LMs belonging to the ω-3/ω-6 lipid classes with clinical and biochemical (serum neurofilament light [sNfL] and serum glial fibrillary acidic protein [sGFAP]) parameters and MRI-based brain volumes in patients with MS (PwMS) and healthy controls (HCs). METHODS: A targeted high-performance liquid chromatography-tandem mass spectrometry approach was used on plasma samples of PwMS and HCs of the Project Y cohort, a cross-sectional population-based cohort that contains PwMS all born in 1966 in the Netherlands and age-matched HCs. LMs were compared between PwMS and HCs and were correlated with levels of sNfL, sGFAP, disability (Expanded Disability Status Scale [EDSS]), and brain volumes. Finally, significant correlates were included in a backward multivariate regression model to identify which LMs best related to disability. RESULTS: The study sample consisted of 170 patients with relapsing remitting MS (RRMS), 115 patients with progressive MS (PMS), and 125 HCs. LM profiles of patients with PMS significantly differed from those of patients with RRMS and HCs, particularly patients with PMS showed elevated levels of several arachidonic acid (AA) derivatives. In particular, 15-hydroxyeicosatetraenoic acid (HETE) (r = 0.24, p < 0.001) correlated (average r = 0.2, p < 0.05) with clinical and biochemical parameters such as EDSS and sNfL. In addition, higher 15-HETE levels were related to lower total brain (r = -0.24, p = 0.04) and deep gray matter volumes (r = -0.27, p = 0.02) in patients with PMS and higher lesion volume (r = 0.15, p = 0.03) in all PwMS. DISCUSSION: In PwMS of the same birth year, we show that ω-3 and ω-6 LMs are associated with disability, biochemical parameters (sNfL, GFAP), and MRI measures. Furthermore, our findings indicate that, particularly, in patients with PMS, elevated levels of specific products of the AA pathway, such as 15-HETE, associate with neurodegenerative processes. Our findings highlight the potential relevance of ω-6 LMs in the pathogenesis of MS.

Dimethyl itaconate induces long-term innate immune responses and confers protection against infection.

Itaconate is an immunomodulatory metabolite produced by immune cells under microbial stimulation and certain pro-inflammatory conditions and triggers antioxidant and anti-inflammatory responses. We show that dimethyl itaconate, a derivative of itaconate previously linked to suppression of inflammation and widely employed as an alternative to the endogenous metabolite, can induce long-term transcriptional, epigenomic, and metabolic changes, characteristic of trained immunity. Dimethyl itaconate alters glycolytic and mitochondrial energetic metabolism, ultimately leading to increased responsiveness to microbial ligand stimulation. Subsequently, mice treated with dimethyl itaconate present increased survival to infection with Staphylococcus aureus. Additionally, itaconate levels in human plasma correlate with enhanced ex vivo pro-inflammatory cytokine production. Collectively, these findings demonstrate that dimethyl itaconate displays short-term anti-inflammatory characteristics and the capacity to induce long-term trained immunity. This pro-and anti-inflammatory dichotomy of dimethyl itaconate is likely to induce complex immune responses and should be contemplated when considering itaconate derivatives in a therapeutic context.