PubMed
Oral nicotinamide provides robust, dose-dependent structural and metabolic neuroprotection of retinal ganglion cells in experimental glaucoma
Acta Neuropathol Commun. 2024 Aug 23;12(1):137. doi: 10.1186/s40478-024-01850-8.ABSTRACTA compromised capacity to maintain NAD pools is recognized as a key underlying pathophysiological feature of neurodegenerative diseases. NAD acts as a substrate in major cell functions including mitochondrial homeostasis, cell signalling, axonal transport, axon/Wallerian degeneration, and neuronal energy supply. Dendritic degeneration is an early marker of neuronal stress and precedes cell loss. However, little is known about dendritic structural preservation in pathologic environments and remodelling in mature neurons. Retinal ganglion cell dendritic atrophy is an early pathological feature in animal models of the disease and has been demonstrated in port-mortem human glaucoma samples. Here we report that a nicotinamide (a precursor to NAD through the NAD salvage pathway) enriched diet provides robust retinal ganglion cell dendritic protection and preserves dendritic structure in a rat model of experimental glaucoma. Metabolomic analysis of optic nerve samples from the same animals demonstrates that nicotinamide provides robust metabolic neuroprotection in glaucoma. Advances in our understanding of retinal ganglion cell metabolic profiles shed light on the energetic shift that triggers early neuronal changes in neurodegenerative diseases. As nicotinamide can improve visual function short term in existing glaucoma patients, we hypothesize that a portion of this visual recovery may be due to dendritic preservation in stressed, but not yet fully degenerated, retinal ganglion cells.PMID:39180087 | DOI:10.1186/s40478-024-01850-8
Multi-omics analyses reveal the responses of wheat (Triticum aestivum L.) and rhizosphere bacterial community to nano(micro)plastics stress
J Nanobiotechnology. 2024 Aug 23;22(1):507. doi: 10.1186/s12951-024-02777-x.ABSTRACTThe pervasive existence of nanoplastics (NPs) and microplastics (MPs) in soil has become a worldwide environmental concern. N/MPs exist in the environment in a variety of forms, sizes, and concentrations, while multi-omics studies on the comprehensive impact of N/MPs with different properties (e.g. type and size) on plants remain limited. Therefore, this study utilized multi-omics analysis methods to investigate the effects of three common polymers [polyethylene-NPs (PE-NPs, 50 nm), PE-MPs (PE-MPs, 10 μm), and polystyrene-MPs (PS-MPs, 10 μm)] on the growth and stress response of wheat, as well as the rhizosphere microbial community at two concentrations (0.05 and 0.5 g/kg). PS and PE exhibited different effects for the same particle size and concentration. PE-NPs had the most severe stress effects, resulting in reduced rhizosphere bacteria diversity, plant biomass, and antioxidant enzyme activity while increasing beneficial bacteria richness. N/MPs altered the expression of nitrogen-, phosphorus-, and sulfur-related functional genes in rhizosphere bacteria, thereby affecting photosynthesis, as well as metabolite and gene levels in wheat leaves. Partial least squares pathway models (PLSPMs) indicated that concentration, size, and type play important roles in the impact of N/MPs on the plant ecological environment, which could have essential implications for assessing the environmental risk of N/MPs.PMID:39180071 | DOI:10.1186/s12951-024-02777-x
HiPSC-derived 3D neural models reveal neurodevelopmental pathomechanisms of the Cockayne Syndrome B
Cell Mol Life Sci. 2024 Aug 23;81(1):368. doi: 10.1007/s00018-024-05406-w.ABSTRACTCockayne Syndrome B (CSB) is a hereditary multiorgan syndrome which-through largely unknown mechanisms-can affect the brain where it clinically presents with microcephaly, intellectual disability and demyelination. Using human induced pluripotent stem cell (hiPSC)-derived neural 3D models generated from CSB patient-derived and isogenic control lines, we here provide explanations for these three major neuropathological phenotypes. In our models, CSB deficiency is associated with (i) impaired cellular migration due to defective autophagy as an explanation for clinical microcephaly; (ii) altered neuronal network functionality and neurotransmitter GABA levels, which is suggestive of a disturbed GABA switch that likely impairs brain circuit formation and ultimately causes intellectual disability; and (iii) impaired oligodendrocyte maturation as a possible cause of the demyelination observed in children with CSB. Of note, the impaired migration and oligodendrocyte maturation could both be partially rescued by pharmacological HDAC inhibition.PMID:39179905 | DOI:10.1007/s00018-024-05406-w
Untargeted Metabolomics Revealed that Quercetin Inhibited Ferroptosis by Improving Metabolic Disorder in the Hippocampus of Perimenopausal Depression Model Rats
Mol Neurobiol. 2024 Aug 24. doi: 10.1007/s12035-024-04445-5. Online ahead of print.ABSTRACTPerimenopausal depression is often accompanied by metabolic disorders, which have long-term harmful effects on women's physical and mental health. Quercetin, a kind of phytoestrogen, has anti-inflammatory, antioxidant, and nerve-protective effects, and can regulate various metabolic disorders. This study aims to investigate the effect of quercetin on hippocampal metabolic disorder in perimenopausal depression rat models based on untargeted metabolomics technology. The rat model of perimenopausal depression was established by ovariectomy combined with chronic unpredictable mild stress (OVX-CUMS). Rats with no difference in sucrose preference were randomly divided into four groups (n = 12): sham group, OVX-CUMS group (model group), model plus quercetin group, and model plus 17β-estradiol group. At the end of the experiment, hippocampal tissues were collected for untargeted metabolomics analysis, morphological analysis, and detection of related indicators. Metabolomics identified 23 differential metabolites in the model group, and the pathway analysis discovered hippocampus metabolic abnormalities including the metabolism of arachidonic acid metabolism, glycerophospholipid metabolism, and ubiquinone biosynthesis, accompanied by an increase in oxidative stress, inflammation, and lipid peroxidation indicators. At the same time, the morphological characteristics of ferroptosis occurred in the hippocampus in the model group. These abnormal changes were reversed by treatment with quercetin or 17β-estradiol. Quercetin can improve perimenopausal depression by regulating hippocampal metabolic disorders and reducing hippocampal ferroptosis in rats. These findings provide a new strategy for the use of quercetin in the prevention and treatment of perimenopausal depression.PMID:39179684 | DOI:10.1007/s12035-024-04445-5
A Clostridioides difficile endolysin modulates toxin secretion without cell lysis
Commun Biol. 2024 Aug 23;7(1):1044. doi: 10.1038/s42003-024-06730-4.ABSTRACTThe Clostridia produce and secrete Large Clostridial Glucosylating Toxins (LCGTs) responsible for disease symptoms, but the secretion mechanism is largely unknown. Recently, a holin-like protein was shown to be essential for toxin secretion. Holins, typically bacteriophage-specific proteins, are part of the holin-endo(lysin) system that releases phage progeny. To determine if the clostridia also use a lysin, we investigated two conserved putative lysins, M7404_01910 and M7404_02200, in the release of the LCGTs TcdA and TcdB from a Clostridioides difficile ribotype 027 strain, M7404. Sequence analysis and structural modelling indicates that both proteins are related to N-acetylmuramoyl-l-alanine amidases, similar to CD27L, a lysin from the C. difficile phage ΦCD27. Disruption of these genes reveal that only M7404_02200 contributes to toxin secretion and does so in a non-lytic fashion. Peptidoglycan hydrolysis assays show that recombinant M7404_02200 is an active peptidoglycan amidase, confirming its role in TcdA and TcdB secretion in C. difficile M7404.PMID:39179651 | DOI:10.1038/s42003-024-06730-4
Metabolites profiling, in-vitro and molecular docking studies of five legume seeds for Alzheimer's disease
Sci Rep. 2024 Aug 23;14(1):19637. doi: 10.1038/s41598-024-68743-7.ABSTRACTEven though legumes are valuable medicinal plants with edible seeds that are extensively consumed worldwide, there is little information available on the metabolic variations between different dietary beans and their influence as potential anti-cholinesterase agents. High-resolution liquid chromatography coupled with mass spectrometry in positive and negative ionization modes combined with multivariate analysis were used to explore differences in the metabolic profiles of five commonly edible seeds, fava bean, black-eyed pea, kidney bean, red lentil, and chickpea. A total of 139 metabolites from various classes were identified including saponins, alkaloids, phenolic acids, iridoids, and terpenes. Chickpea showed the highest antioxidant and anti-cholinesterase effects, followed by kidney beans. Supervised and unsupervised chemometric analysis determined that species could be distinguished by their different discriminatory metabolites. The major metabolic pathways in legumes were also studied. Glycerophospholipid metabolism was the most significantly enriched KEGG pathway. Pearson's correlation analysis pinpointed 18 metabolites that were positively correlated with the anti-cholinesterase activity. Molecular docking of the biomarkers to the active sites of acetyl- and butyryl-cholinesterase enzymes revealed promising binding scores, validating the correlation results. The present study will add to the metabolomic analysis of legumes and their nutritional value and advocate their inclusion in anti-Alzheimer's formulations.PMID:39179586 | DOI:10.1038/s41598-024-68743-7
Unraveling the metabolomic profile and acute toxicity of ethanolic extract from Mimosa tenuiflora (Willd.) Poir. root bark
Toxicon. 2024 Aug 21:108076. doi: 10.1016/j.toxicon.2024.108076. Online ahead of print.ABSTRACTMimosa tenuiflora (Fabaceae) is popularly known in Brazil as "Jurema preta". From the bark of its root, "jurema wine" is obtained, a psychedelic drink used in Indigenous religious rituals in Northeastern Brazil. This work aimed to investigate the chemical composition and acute oral toxicity of the ethanolic extract of the root bark from M. tenuiflora (EEMt). EEMt was analyzed by UPLC-QToF-MS/MS and DI-ESI-IT-MSn. Oral administration of EEMt was performed once at doses of 300 and 2000 mg/kg in female Swiss mice. Signs and symptoms of intoxication, as well as mortality were monitored for 14 days. Thirteen compounds were annotated in EEMt: eight type B proanthocyanidins, three alkaloids, a glycosylated flavonol, and a dihydrochalcone derivative. The acute administration of 300 and 2000 mg/kg of EEMt did not show mortality. It also did not change the food intake or body weight of the animals. However, the relative weights of the kidneys were significantly changed for both doses. Changes in hematological and biochemical parameters were found. In addition, histopathological changes were also observed in the heart, liver, and kidneys. Thus, based on our findings, EEMt presented an LD50 greater than 2000 mg/kg and was therefore classified in category 5 of the Globally Harmonized Classification System (GHS). EEMt showed acute oral toxicity by altering hematological, biochemical and histological parameters.PMID:39179178 | DOI:10.1016/j.toxicon.2024.108076
Nicotinamide riboside modulates the reactive species interactome, bioenergetic status and proteomic landscape in a brain-region-specific manner
Neurobiol Dis. 2024 Aug 21:106645. doi: 10.1016/j.nbd.2024.106645. Online ahead of print.ABSTRACTNicotinamide riboside (NR), a precursor of nicotinamide adenine dinucleotide (NAD+), has robust cognitive benefits and alleviates neuroinflammation in AD mouse models without decreasing beta-amyloid plaque pathology. Such effects may be mediated by the reactive species interactome (RSI), at the metabolome level. In this study, we employed in vitro and in vivo models of oxidative stress/aging/AD to profile the effects of NR on neuronal survival, RSI, and the whole proteome characterization of cortex and hippocampus. RSI analysis yielded a complex modulation upon NR treatment. We constructed protein co-expression networks and correlated them to NR treatment and all measured reactive species. We observed brain-area specific effects of NR on co-expressed protein modules of oxidative phosphorylation, fatty acid oxidation, and neurotransmitter regulation pathways, which correlated with RSI components. The current study contributes to the understanding of modulation of the metabolome, specifically after NR, in AD and how it may play disease-modifying roles.PMID:39179121 | DOI:10.1016/j.nbd.2024.106645
Si-Ni-San alleviates intestinal and liver damage in ulcerative colitis mice by regulating cholesterol metabolism
J Ethnopharmacol. 2024 Aug 21:118715. doi: 10.1016/j.jep.2024.118715. Online ahead of print.ABSTRACTETHNOPHARMACOLOGICAL RELEVANCE: Si-Ni-San (SNS), a traditional Chinese medicinal formula derived from Treatise on Febrile Diseases, is considered effective in the treatment of inflammatory bowel diseases based upon thousands of years of clinical practice. However, the bioactive ingredients and underlying mechanisms are still unclear and need further investigation.AIM OF THE STUDY: This study aimed to evaluate the effect, explore the bioactive ingredients and the underlying mechanisms of SNS in ameliorating ulcerative colitis (UC) and associated liver injury in dextran sodium sulphate (DSS)-induced mouse colitis models.MATERIALS AND METHODS: The effect of SNS (1.5, 3, 6g/kg) on 3% DSS-induced acute murine colitis was evaluated by disease activity index (DAI), colon length, inflammatory cytokines, hematoxylin-eosin (H&E) staining, tight junction proteins expression, ALT, AST, and oxidative stress indicators. HPLC-ESI-IT/TOF MS was used to analyze the chemical components of SNS and the main xenobiotics in the colon of UC mice after oral administration of SNS. Network pharmacological study was then conducted based on the main xenobiotics. Flow cytometry and immunohistochemistry techniques were used to demonstrate the inhibitory effect of SNS on Th17 cells differentiation and the amelioration of Th17/Treg cell imbalance. LC-MS/MS, Real-time quantitative polymerase chain reaction (RT-qPCR), and western blotting techniques were performed to investigate the oxysterol-Liver X receptor (LXRs) signaling activity in colon. Targeted bile acids metabolomics was conducted to reveal the change of the two major pathways of bile acid synthesis in the liver, and the expression of key metabolic enzymes of bile acids synthesis was characterized by RT-qPCR and western blotting techniques.RESULTS: SNS (1.5, 3, 6g/kg) decreased the DAI scores, protected intestinal mucosa barrier, suppressed the production of pro-inflammatory cytokines, improved hepatic and splenic enlargement and alleviated liver injury in a dose-dependent manner. A total of 22 components were identified in the colon of SNS (6g/kg) treated colitis mice, and the top 10 components ranked by relative content were regarded as the potential effective chemical components of SNS, and used to conduct network pharmacology research. The efficacy of SNS was mediated by a reduction of Th17 cell differentiation, restoration of Th17/Treg cell homeostasis in the colon and spleen, and the experimental results were consistent with our hypothesis and the biological mechanism predicted by network pharmacology. Mechanistically, SNS regulated the concentration of 25-OHC and 27-OHC by up-regulated CH25H, CYP27A1 protein expression in colon, thus affected the expression and activity of LXR, ultimately impacted Th17 differentiation and Th17/Treg balance. It was also found that SNS repressed the increase of hepatic cholesterol and reversed the shift of BA synthesis to the acidic pathway in UC mice, which decreased the proportion of non-12-OH BAs in total bile acids (TBAs) and further ameliorated colitis and concomitant liver injury.CONCLUSIONS: This study set the stage for considering SNS as a multi-organ benefited anti-colitis prescription based on the significant effect of ameliorating intestinal and liver damage, and revealed that derivatives of cholesterol, namely oxysterols and bile acids, were closely involved in the mechanism of SNS anti-colitis effect.PMID:39179058 | DOI:10.1016/j.jep.2024.118715
The metabolic network response and tolerance mechanism of Thalassia hemprichii under high sulfide based on widely targeted metabolome and transcriptome
Sci Total Environ. 2024 Aug 21:175702. doi: 10.1016/j.scitotenv.2024.175702. Online ahead of print.ABSTRACTCostal eutrophication leads to increased sulfide levels in sediments, which has been identified as a major cause of the global decline in seagrass beds. The seagrass Thalassia hemprichii, a dominant tropical species in the Indo-Pacific, is facing a potential threat from sulfide, which can be easily reduced from sulfate in porewater under the influence of global climate change and eutrophication. However, its metabolic response and tolerance mechanisms to high sulfide remain unclear. Thus, the current study investigated the physiological responses and programmed metabolic networks of T. hemprichii through a three-week mesocosm experiment, integrating physiology, stable isotope, widely targeted metabolomics, transcriptomics, and microbial diversity assessments. High sulfide reduced the sediment microbial diversity, while increased sediment sulfate reduced bacterial abundance and δ34S. The exposure to sulfide enhanced root δ34S while decreased leaf δ34S in T. hemprichii. High sulfide was shown to inhibit photosynthesis via damaging PSII, which further reduced ATP production. In response, abundant up-regulated differentially expressed genes in energy metabolism, especially in oxidative phosphorylation, were activated to compensate high energy requirement. High sulfide also promoted autophagy by overexpressing the genes related to phagocytosis and phagolysosome. Meanwhile, metabolomic profiling revealed that the contents of many primary metabolites, such as carbohydrates and amino acids, were reduced in both leaves and roots, likely to provide more energy and synthesize stress-responsive secondary metabolites. Genes related to nitrate reduction and transportation were up-regulated to promote N uptake for sulfide detoxification. High sulfide levels specifically enhanced thiamine in roots, while increased jasmonic acid and flavonoid levels in leaves. The distinct differences in metabolism between roots and leaves might be related to sulfide levels and the growth-defense trade-off. Collectively, our work highlights the specific mechanisms underlying the response and tolerance of T. hemprichii to high sulfide, providing new insights into seagrass strategies for resisting sulfide.PMID:39179040 | DOI:10.1016/j.scitotenv.2024.175702
UV light exposure vs. vitamin D supplementation: a comparison of health benefits and vitamin D metabolism in a pig model
J Nutr Biochem. 2024 Aug 21:109746. doi: 10.1016/j.jnutbio.2024.109746. Online ahead of print.ABSTRACTThere is limited data on the effect of UV light exposure versus orally ingested vitamin D3 on vitamin D metabolism and health. A 4-week study with 16 pigs (as a model for human physiology) was conducted. The pigs were either supplemented with 20 µg/d vitamin D3 or exposed to UV light for 19 min/d to standardise plasma 25-hydroxyvitamin D3 levels. Important differences were higher levels of stored vitamin D3 in skin and subcutaneous fat, higher plasma concentrations of 3-epi-25-hydroxyvitamin D3 and increases of cutaneous lumisterol3 in UV-exposed pigs compared to supplemented pigs. UV light exposure compared to vitamin D3 supplementation resulted in lower hepatic cholesterol, higher circulating plasma nitrite, a marker of the blood pressure-lowering nitric oxide, and a reduction in the release of pro- and anti-inflammatory cytokines from stimulated peripheral blood mononuclear cells. However, plasma metabolome and stool microbiome analyses did not reveal any differences between the two groups. To conclude, the current data show important health relevant differences between oral vitamin D3 supplementation and UV light exposure. The findings may also partly explain the different vitamin D effects on health parameters obtained from association and intervention studies.PMID:39178919 | DOI:10.1016/j.jnutbio.2024.109746
Investigation of newborn blood metabolomics in varying intrauterine growth conditions
J Pediatr (Rio J). 2024 Aug 20:S0021-7557(24)00102-5. doi: 10.1016/j.jped.2024.07.009. Online ahead of print.ABSTRACTOBJECTIVES: This study aimed to investigate changes in the blood metabolic profiles of newborns with varying intrauterine growth conditions. Specifically, we analyzed the levels of amino acids, carnitine, and succinylacetone among full-term newborns, including small for gestational age (SGA), appropriate for gestational age (AGA), and large for gestational age (LGA). We aim to identify differential metabolites and metabolic pathways that may offer insights into clinical interventions.METHODS: A total of 5106 full-term newborns were included in the study. Blood samples were obtained from all newborns between 3 and 5 days after birth and analyzed using tandem mass spectrometry to detect blood metabolites. Subsequently, we screened for different metabolites and metabolic pathways among the groups using the MetaboAnalystR package (Version 1.0.1) in R software (R-3.6.0).RESULTS: The levels of blood amino acids and carnitine metabolism differed significantly among newborns with varying intrauterine growth conditions. Full-term SGA newborns exhibited a decrease in multiple amino acids and an increase in multiple carnitines, while full-term LGA newborns showed an increase in multiple amino acids and acylcarnitines.CONCLUSION: Continuous monitoring of the short-term and long-term growth and metabolic status of full-term SGA and LGA newborns is warranted with individualized dietary and nutritional adjustments to promote healthy growth in a timely manner. The findings of this research contribute to the broader understanding of SGA/LGA and shall inform future research on metabolomics, interventions, and long-term outcomes.PMID:39178913 | DOI:10.1016/j.jped.2024.07.009
Hawthorn-leaf flavonoid alleviate intestinal health and microbial dysbiosis problems induced by glyphosate
Ecotoxicol Environ Saf. 2024 Aug 22;284:116901. doi: 10.1016/j.ecoenv.2024.116901. Online ahead of print.ABSTRACTGlyphosate is the active ingredient in the herbicide (i.e., Roundup, Touchdown and Erasure), the safety of which has become a social concern. Hawthorn-leaf flavonoid (HF) possesses various biological functions, including antioxidant, regulating lipid metabolism and intestinal microbiota. Whether HF could reduce the health risk of pure glyphosate to birds remain unknown. The experiment aimed to evaluate the effects of pure glyphosate (25 mg/kg added to water) on the intestinal health and microbiota of chicks and the protective roles of HF (60 mg/kg added to the diet). Exposure to glyphosate decreased growth performance, ileal morphology structure, and antioxidant capacity, and increased the serum level of lipid and pro-inflammatory factors. 16S rRNA sequencing indicated that glyphosate decreased bacterial richness and the abundance of Lactobacillus, and increased proportions of pathogens in the ileum. Metabolomic results revealed that glyphosate increased the level of the cholic acid and fatty acids in the ileac digesta. Meanwhile, glyphosate down-regulated the protein expression associated with lipid transport, antioxidant and tight junction in the ileal mucosal tissue, and up-regulated the pro-inflammatory, oxidative stress proteins. However, dietary HF supplementation effectively mitigated the adverse effects of glyphosate and improved intestinal health of chicks. Therefore, dietary HF can ameliorate the harmful effects of glyphosate on birds, which highlights the potential application of HF in reducing the health risks.PMID:39178762 | DOI:10.1016/j.ecoenv.2024.116901
Exploring the anti-ovarian aging mechanism of He's Yangchao formula: Insights from multi-omics analysis in naturally aged mice
Phytomedicine. 2024 Aug 17;134:155961. doi: 10.1016/j.phymed.2024.155961. Online ahead of print.ABSTRACTBACKGROUND: The rapid acceleration of female reproductive aging has become a major public health concern. He's Yangchao formula (HSYC), a compound comprising eight herbs, has demonstrated efficacy in enhancing ovarian function. Thus, an in-depth study of its anti-ovarian aging mechanism is required.PURPOSE: To evaluate the anti-ovarian aging effect of HSYC in naturally aged mice and investigate the underlying mechanism by analyzing the gut microbiota (GM), metabolome, and transcriptome.METHODS: Young and advanced maternal age (AMA) mice were selected for this study. Hematoxylin and eosin staining, fluorescence staining, western blotting, and qPCR analyses were used to detect the phenotypes associated with ovarian aging. Subsequently, analyses of the GM, transcriptome, and metabolome analyses were performed to explore the potential mechanisms of action of HSYC. Finally, in vivo and in vitro experiments were performed to verify potential therapeutic mechanisms.RESULTS: HSYC promoted follicular development in AMA mice and ameliorated age-related mitochondrial dysfunction, apoptosis, and defects in DNA damage repair. GM analysis revealed that HSYC treatment significantly increased the abundance of Akkermansia and Turicibacter. Transcriptome and metabolome analyses showed that HSYC might mitigate ovarian aging by regulating metabolic pathways, amino acid metabolism, glutathione metabolism, and the synthesis of pantothenic acid and coenzyme A. Combined transcriptomic and metabolomic analyses identified the glutathione metabolic pathway as the key pathway through which HSYC counteracts ovarian aging. Additional experimental verification confirmed that HSYC upregulated the glutathione metabolic genes GPX8, GSTA1, and GSTA4, increased glutathione-related products (GSH), and reduced ROS levels.CONCLUSIONS: HSYC exerts beneficial therapeutic effects on ovarian aging by regulating multiple endogenous metabolites, targets, and metabolic pathways, with an emphasis on its anti-ovarian aging effects through the glutathione metabolic pathway. These findings underscore the innovative potential of HSYC in addressing ovarian aging and offer a novel therapeutic approach that targets multiple biological pathways to improve the reproductive health of women with AMA..PMID:39178679 | DOI:10.1016/j.phymed.2024.155961
Silymarin targets the FXR protein through microbial metabolite 7-keto-deoxycholic acid to treat MASLD in obese mice
Phytomedicine. 2024 Aug 8;133:155947. doi: 10.1016/j.phymed.2024.155947. Online ahead of print.ABSTRACTBACKGROUND: Silymarin is recognized for its excellent hepato-protective properties. Recent clinical studies have examined the effects of silymarin on metabolic dysfunction-associated steatotic liver disease (MASLD), highlighting the necessity of further exploration into optimal dosages, active components, and mechanisms of action.METHODS AND RESULTS: This study assessed the anti-inflammatory activity of the principal constituents of silymarin at the cellular level. The therapeutic effects of varying silymarin doses and components on MASLD in mouse models induced by a high-fat diet (HFD) were also examined. These findings indicate the superior efficacy of 80 mg kg-1 silymarin in mitigating liver steatosis and reducing lipid accumulation compared to 30 mg kg-1 silymarin or a combination of silybin and isosilybin A. The mechanism of silymarin involves regulating gut microbiota homeostasis and influencing the TLR4/NF-κB signalling pathway through LPS. Bile acid-targeted metabolomics analysis revealed that silymarin significantly decreases the HFD-induced increase in 7-keto-deoxycholic acid (7-KDCA). Further investigations suggested that 7-KDCA as an antagonist targeted farnesoid X receptor (FXR) and that both silybin and isosilybin A could directly interact with FXR.CONCLUSION: These findings elucidate that 80 mg kg-1 of silymarin can exert therapeutic effects on MASLD mice and offer novel insights into the mechanism of silymarin in treating MASLD. Especially, it was found that silymarin could regulate bile acid metabolism, reduce the concentration of 7-KDCA, and thus perform negative feedback regulation on FXR.PMID:39178642 | DOI:10.1016/j.phymed.2024.155947
Untargeted metabolomics analyses to identify a new sweet compound released during post-fermentation maceration of wine
Food Chem. 2024 Aug 8;461:140801. doi: 10.1016/j.foodchem.2024.140801. Online ahead of print.ABSTRACTThe sensory quality of a wine is mainly based on its aroma and flavor. Sweetness contributes in the gustatory balance of red wines. The investigation of compounds involved in this flavor was based on empirical observations, such as the increase in wine sweetness during yeast autolysis, concomitant to post-fermentation maceration in red winemaking. An untargeted metabolomics approach using UHPLC-HRMS has been developed to discover a new sweet molecule released during this stage. Among several markers highlighted, one compound was selected to be isolated by various separative techniques. It was unambiguously identified by NMR as N6-succinyladenosine and is reported for the first time in wine at an average concentration of 3.16 mg/L in 85 red wines. Furthermore, sensory analysis has highlighted its sweetness. In addition to discovering a new sweet compound in wine, this study proposes new tools for studying taste-active compounds in natural matrices.PMID:39178544 | DOI:10.1016/j.foodchem.2024.140801
Investigating the lipid profile of Anopheles stephensi mosquitoes across developmental life stages
Comp Biochem Physiol Part D Genomics Proteomics. 2024 Aug 14;52:101312. doi: 10.1016/j.cbd.2024.101312. Online ahead of print.ABSTRACTHolometabolous insects undergo a distinct transition in their development, tightly correlated with shifting feeding patterns from larval stages and some adult phases to non-feeding phases as pupae and during other adult phases. Furthermore, the intricate life cycle of mosquitoes involves a sequence of developmental stages influenced by aquatic and terrestrial factors, demanding precise energy resource orchestration. Lipids serve multifaceted roles, encompassing energy storage, membrane structure, and participation in signal transduction and molecular recognition processes. A significant gap in the current research landscape is the need for a comprehensive study exploring the lipid repertoire throughout the developmental stages of Anopheles stephensi mosquitoes. We undertook an analysis of the An. stephensi metabolome across all life stages. We hypothesized that An. stephensi mosquitoes will have unique lipid metabolite markers for each life stage. A specific extraction and LC-MS based lipidomic approach was used to test this hypothesis. Our findings demonstrated that our methods were successful, with lipids comprising 62.15 % of the analyzed metabolome. Additionally, phospholipids (PL), lysophospholipids (LPL), sphingomyelin (SM), and triglycerides (TG) were abundant and dynamic across all life stages. Interestingly, comparison between the L1 and L2 lipidome revealed a dominant pattern of specific TGs in decreased abundance between these two life stages. Lastly, 20-hydroxyecdysone (20E), was found to be present in similar abundance across all 4 larval stages. These data indicate that there may be lipid metabolome pathways serving unique roles during mosquito development that may be used to explore laboratory management of colonies, parasite resistance, and environmental adaptation.PMID:39178499 | DOI:10.1016/j.cbd.2024.101312
Probiotics-regulated lithocholic acid suppressed B-cell differentiation in neuromyelitis optica spectrum disorder
J Neuroimmunol. 2024 Aug 2;395:578422. doi: 10.1016/j.jneuroim.2024.578422. Online ahead of print.ABSTRACTIntestinal microbes play a crucial role in gut health and the immune-mediated central nervous system through the "gut-brain" axis. However, probiotic safety and efficacy in Neuromyelitis optica spectrum disorder (NMOSD) are not well-explored. A pilot clinic trial for NMOSD with probiotic intervention revealed alterations in the microbiota (increased Anaerostipes, Bacteroides; decreased Granulicatella, Streptococcus, Rothia). Metabolite analysis showed elevated 2-methylbutyric and isobutyric acids, reduced lithocholic acid (LCA), and glycodeoxycholic acid (GDCA). Immune markers Interleukin (IL-7), vascular endothelial growth factor (VEGF-A), and B lymphocyte chemoattractant (BLC) decreased, while plasma cells and transitional B cells increased post-probiotics, suggesting potential immunomodulatory effects on NMOSD.PMID:39178494 | DOI:10.1016/j.jneuroim.2024.578422
High-fat feeding drives the intestinal production and assembly of C<sub>16:0</sub> ceramides in chylomicrons
Sci Adv. 2024 Aug 23;10(34):eadp2254. doi: 10.1126/sciadv.adp2254. Epub 2024 Aug 23.ABSTRACTConsumption of a diet rich in saturated fat increases lipid absorption from the intestine, assembly into chylomicrons, and delivery to metabolic tissues via the lymphatic and circulatory systems. Accumulation of ceramide lipids, composed of sphingosine and a fatty acid, in metabolic tissues contributes to the pathogenesis of cardiovascular diseases, type 2 diabetes mellitus and cancer. Using a mesenteric lymph duct cannulated rat model, we showed that ceramides are generated by the intestine and assembled into chylomicrons, which are transported via the mesenteric lymphatic system. A lipidomic screen of intestinal-derived chylomicrons identified a diverse range of fatty acid, sphingolipid, and glycerolipid species that have not been previously detected in chylomicrons, including the metabolically deleterious C16:0 ceramide that increased in response to high-fat feeding in rats and human high-lipid meal replacement enteral feeding. In conclusion, high-fat feeding increases the export of intestinal-derived C16:0 ceramide in chylomicrons, identifying a potentially unknown mechanism through which ceramides are transported systemically to contribute to metabolic dysfunction.PMID:39178255 | DOI:10.1126/sciadv.adp2254
The nuclear export protein XPO1 provides a peptide ligand for natural killer cells
Sci Adv. 2024 Aug 23;10(34):eado6566. doi: 10.1126/sciadv.ado6566. Epub 2024 Aug 23.ABSTRACTXPO1 (Exportin-1/CRM1) is a nuclear export protein that is frequently overexpressed in cancer and functions as a driver of oncogenesis. Currently small molecules that target XPO1 are being used in the clinic as anticancer agents. We identify XPO1 as a target for natural killer (NK) cells. Using immunopeptidomics, we have identified a peptide derived from XPO1 that can be recognized by the activating NK cell receptor KIR2DS2 in the context of human leukocyte antigen-C. The peptide can be endogenously processed and presented to activate NK cells specifically through this receptor. Although high XPO1 expression in cancer is commonly associated with a poor prognosis, we show that the outcome of specific cancers, such as hepatocellular carcinoma, can be substantially improved if there is concomitant evidence of NK cell infiltration. We thus identify XPO1 as a bona fide tumor antigen recognized by NK cells that offers an opportunity for a personalized approach to NK cell therapy for solid tumors.PMID:39178254 | DOI:10.1126/sciadv.ado6566