PubMed
Gut Microbiota and Derived Metabolites Mediate Obstructive Sleep Apnea Induced Atherosclerosis
bioRxiv [Preprint]. 2024 Nov 19:2024.11.18.624205. doi: 10.1101/2024.11.18.624205.ABSTRACTBACKGROUND: Obstructive sleep apnea (OSA) is characterized by intermittent hypoxia/hypercapnia (IHC), affects predominantly obese individuals, and increases atherosclerosis risk. Since we and others have implicated gut microbiota and metabolites in atherogenesis, we dissected their contributions to OSA-induced atherosclerosis.RESULTS: Atherosclerotic lesions were compared between conventionally-reared specific pathogen free (SPF) and germ-free (GF) ApoE -/- mice following a high fat high cholesterol diet (HFHC), with and without IHC conditions. The fecal microbiota and metabolome were profiled using 16S rRNA gene amplicon sequencing and untargeted tandem mass spectrometry (LC-MS/MS) respectively. Phenotypic data showed that HFHC significantly increased atherosclerosis as compared to regular chow (RC) in both aorta and pulmonary artery (PA) of SPF mice. IHC exacerbated lesions in addition to HFHC. Differential abundance analysis of gut microbiota identified an enrichment of Akkermansiaceae and a depletion of Muribaculaceae (formerly S24-7) family members in the HFHC-IHC group. LC-MS/MS showed a dysregulation of bile acid profiles with taurocholic acid, taurodeoxycholic acid, and 12-ketodeoxycholic acid enriched in the HFHC-IHC group, long-chain N-acyl amides, and phosphatidylcholines. Interestingly, GF ApoE -/- mice markedly reduced atherosclerotic formation relative to SPF ApoE -/- mice in the aorta under HFHC/IHC conditions. In contrast, microbial colonization did not show a significant impact on the atherosclerotic progression in PA.CONCLUSIONS: In summary, this research demonstrated that (1) IHC acts cooperatively with HFHC to induce atherosclerosis; (2) gut microbiota modulate atherogenesis, induced by HFHC/IHC, in the aorta not in PA; (3) different analytical methods suggest that a specific imbalance between Akkermansiaceae and Muribaculaceae bacterial families mediate OSA-induced atherosclerosis; and (4) derived bile acids, such as deoxycholic acid and lithocholic acid, regulate atherosclerosis in OSA. The knowledge obtained provides novel insights into the potential therapeutic approaches to prevent and treat OSA-induced atherosclerosis.PMID:39605650 | PMC:PMC11601605 | DOI:10.1101/2024.11.18.624205
Appearance of green tea compounds in plasma following acute green tea consumption is modulated by the gut microbiome in mice
bioRxiv [Preprint]. 2024 Nov 13:2024.07.11.603097. doi: 10.1101/2024.07.11.603097.ABSTRACTStudies have suggested that phytochemicals in green tea have systemic anti-inflammatory and neuroprotective effects. However, the mechanisms behind these effects are poorly understood, possibly due to differential metabolism of phytochemicals resulting from variation in gut microbiome composition. To unravel this complex relationship, our team utilized a novel combined microbiome analysis and metabolomics approach applied to low complexity microbiome (LCM) and human colonized (HU) gnotobiotic mice treated with an acute dose of powdered matcha green tea. A total of 20 LCM mice received 10 distinct human fecal slurries for an n=2 mice per human gut microbiome; 9 LCM mice remained un-colonized with human slurries throughout the experiment. We performed untargeted metabolomics on green tea and plasma to identify green tea compounds that were found in plasma of LCM and HU mice that had consumed green tea. 16S ribosomal RNA gene sequencing was performed on feces of all mice at study end to assess microbiome composition. We found multiple green tea compounds in plasma associated with microbiome presence and diversity (including acetylagmatine, lactiflorin, and aspartic acid negatively associated with diversity). Additionally, we detected strong associations between bioactive green tea compounds in plasma and specific gut bacteria, including associations between spiramycin and Gemmiger , and between wildforlide and Anaerorhabdus . Additionally, some of the physiologically relevant green tea compounds are likely derived from plant-associated microbes, highlighting the importance of considering foods and food products as meta-organisms. Overall, we describe a novel workflow for discovering relationships between individual food compounds and composition of the gut microbiome.IMPORTANCE: Foods contain thousands of unique and biologically important compounds beyond the macro- and micro-nutrients listed on nutrition facts labels. In mammals, many of these compounds are metabolized by the community of microbes in the colon. These microbes may impact the thousands of biologically important compounds we consume; therefore, understanding microbial metabolism of food compounds will be important for understanding how foods impact health. We used metabolomics to track green tea compounds in plasma of mice with and without complex microbiomes. From this, we can start to recognize certain groups of green tea-derived compounds that are impacted by mammalian microbiomes. This research presents a novel technique for understanding microbial metabolism of food-derived compounds in the gut, which can be applied to other foods.PMID:39605610 | PMC:PMC11601224 | DOI:10.1101/2024.07.11.603097
Resource landscape shapes the composition and stability of the human vaginal microbiota
bioRxiv [Preprint]. 2024 Nov 13:2024.11.12.622464. doi: 10.1101/2024.11.12.622464.ABSTRACTThe vaginal microbiota has demonstrated associations with women's and newborns' health. Despite its comparatively simple composition relative to other human microbiota systems, the ecological processes that underpin the dynamics and stability of vaginal microbial communities remain mechanistically elusive. A crucial, yet so far under-explored, aspect of vaginal microbiota ecology is the role played by nutritional resources. Glycogen and its derivatives, produced by vaginal epithelia, are accessible to all bacterial constituents of the microbiota. Concurrently, free sialic acid and fucose offer supplementary nutritional resources for bacterial strains capable of cleaving them from glycans, which are structurally integral to mucus. Notably, bacteria adept at sialic acid exploitation are often correlated with adverse clinical outcomes and are frequently implicated in bacterial vaginosis (BV). In this study, we introduce a novel mathematical model tailored to human vaginal microbiota dynamics to explore the interactions between bacteria and their respective nutritional landscapes. Our resource-based model examines the impact of the relative availability of glycogen derivatives (accessible to all bacterial species) and sialic acid (exclusive to some BV-associated bacteria) on the composition of the vaginal microbiota. Our findings elucidate that the prevalence of BV-associated bacteria is intricately linked to their exclusive access to specific nutritional resources. This private access fortifies communities dominated by BV-associated bacteria, rendering them resilient to compositional transitions. We provide empirical support for our model's predictions from longitudinal microbiota composition and metabolomic data, collected from a North American cohort. The insights gleaned from this study shed light on potential pathways for BV prevention.PMID:39605590 | PMC:PMC11601336 | DOI:10.1101/2024.11.12.622464
Metabolomic Analysis of Murine Tissues Infected with Brucella melitensis
bioRxiv [Preprint]. 2024 Nov 16:2024.11.16.623915. doi: 10.1101/2024.11.16.623915.ABSTRACTBrucella is a gram negative, facultative, intracellular bacterial pathogen that constitutes a substantial threat to human and animal health. Brucella can replicate in a variety of tissues and can induce immune responses that alter host metabolite availability. Here, mice were infected with B. melitensis and murine spleens, livers, and female reproductive tracts were analyzed by GC-MS to determine tissue-specific metabolic changes at one-, two- and four-weeks post infection. The most remarkable changes were observed at two-weeks post-infection when relative to uninfected tissues, 42 of 329 detected metabolites in reproductive tracts were significantly altered by Brucella infection, while in spleens and livers, 68/205 and 139/330 metabolites were significantly changed, respectively. Several of the altered metabolites in host tissues were linked to the GABA shunt and glutaminolysis. Treatment of macrophages with GABA did not alter control of B. melitensis infection, and deletion of the putative GABA transporter BMEI0265 did not alter B. melitensis virulence. While glutaminolysis inhibition did not affect control of B. melitensis in macrophages, glutaminolysis was required for macrophage IL-1β production in response to B. melitensis . In sum, these results indicate that Brucella infection alters host tissue metabolism and that these changes could have effects on inflammation and the outcome of infection.PMID:39605528 | PMC:PMC11601316 | DOI:10.1101/2024.11.16.623915
Sugar phosphate-mediated inhibition of peptidoglycan precursor synthesis
bioRxiv [Preprint]. 2024 Nov 14:2024.11.13.623475. doi: 10.1101/2024.11.13.623475.ABSTRACTAntibiotic tolerance, the widespread ability of diverse pathogenic bacteria to sustain viability in the presence of typically bactericidal antibiotics for extended time periods, is an understudied steppingstone towards antibiotic resistance. The Gram-negative pathogen Vibrio cholerae , the causative agent of cholera, is highly tolerant to β-lactam antibiotics. We previously found that the disruption of glycolysis, via deletion of pgi ( vc0374 , glucose-6-phosphate isomerase), resulted in significant cell wall damage and increased sensitivity towards β-lactam antibiotics. Here, we uncover the mechanism of this resulting damage. We find that glucose causes growth inhibition, partial lysis, and a damaged cell envelope in Δ pgi . Supplementation with N-acetylglucosamine, but not other carbon sources (either from upper glycolysis, TCA cycle intermediates, or cell wall precursors) restored growth, re-established antibiotic resistance towards β-lactams, and recovered cellular morphology of a pgi mutant exposed to glucose. Targeted metabolomics revealed the cell wall precursor synthetase enzyme GlmU ( vc2762 , coding for the bifunctional enzyme that converts glucosamine-1P to UDP-GlcNAc) as a critical bottleneck and mediator of glucose toxicity in Δ pgi . In vitro assays of GlmU revealed that sugar phosphates (primarily glucose-1-phosphate) inhibit the acetyltransferase activity of GlmU (likely competitively), resulting in compromised PG and LPS biosynthesis. These findings identify GlmU as a critical branchpoint enzyme between central metabolism and cell envelope integrity and reveal the molecular mechanism of Δ pgi glucose toxicity in Vibrio cholerae .IMPORTANCE: Sugar-phosphate toxicity is a well characterized phenomenon that is seen within diverse bacterial species, and yet the molecular underpinnings remain elusive. We previously discovered that disrupting Vibrio cholerae's ability to eat glucose (by disrupting the pgi gene), also resulted in a damaged cell envelope. Upon deletion of pgi , glucose-phosphate levels rapidly build and inhibit the enzymatic activity of GlmU, a key step of bacterial peptidoglycan precursor synthesis. GlmU inhibition causes enhanced killing by antibiotics and a pronounced cell envelope defect. Thus, GlmU serves as a prime target for novel drug development. This research opens new routes through which central metabolism and sugar-phosphate toxicity modulate antibiotic susceptibility.PMID:39605520 | PMC:PMC11601392 | DOI:10.1101/2024.11.13.623475
Interlaboratory comparison of standardised metabolomics and lipidomics analyses in human and rodent blood using the MxP Quant 500 kit
bioRxiv [Preprint]. 2024 Nov 14:2024.11.13.619447. doi: 10.1101/2024.11.13.619447.ABSTRACTMetabolomics and lipidomics are pivotal in understanding phenotypic variations beyond genomics. However, quantification and comparability of mass spectrometry (MS)-derived data are challenging. Standardised assays can enhance data comparability, enabling applications in multi-center epidemiological and clinical studies. Here we evaluated the performance and reproducibility of the MxP® Quant 500 kit across 14 laboratories. The kit allows quantification of 634 different metabolites from 26 compound classes using triple quadrupole MS. Each laboratory analysed twelve samples, including human plasma and serum, lipaemic plasma, NIST SRM 1950, and mouse and rat plasma, in triplicates. 505 out of the 634 metabolites were measurable above the limit of detection in all laboratories, while eight metabolites were undetectable in our study. Out of the 505 metabolites, 412 were observed in both human and rodent samples. Overall, the kit exhibited high reproducibility with a median coefficient of variation (CV) of 14.3 %. CVs in NIST SRM 1950 reference plasma were below 25 % and 10 % for 494 and 138 metabolites, respectively. To facilitate further inspection of reproducibility for any compound, we provide detailed results from the in-depth evaluation of reproducibility across concentration ranges using Deming regression. Interlaboratory reproducibility was similar across sample types, with some species-, matrix-, and phenotype-specific differences due to variations in concentration ranges. Comparisons with previous studies on the performance of MS-based kits (including the AbsoluteIDQ p180 and the Lipidyzer) revealed good concordance of reproducibility results and measured absolute concentrations in NIST SRM 1950 for most metabolites, making the MxP® Quant 500 kit a relevant tool to apply metabolomics and lipidomics in multi-center studies.PMID:39605511 | PMC:PMC11601468 | DOI:10.1101/2024.11.13.619447
Chronic Viral Reactivation and Associated Host Immune Response and Clinical Outcomes in Acute COVID-19 and Post-Acute Sequelae of COVID-19
bioRxiv [Preprint]. 2024 Nov 16:2024.11.14.622799. doi: 10.1101/2024.11.14.622799.ABSTRACTChronic viral infections are ubiquitous in humans, with individuals harboring multiple latent viruses that can reactivate during acute illnesses. Recent studies have suggested that SARS- CoV-2 infection can lead to reactivation of latent viruses such as Epstein-Barr Virus (EBV) and cytomegalovirus (CMV), yet, the extent and impact of viral reactivation in COVID-19 and its effect on the host immune system remain incompletely understood. Here we present a comprehensive multi-omic analysis of viral reactivation of all known chronically infecting viruses in 1,154 hospitalized COVID-19 patients, from the Immunophenotyping Assessment in a COVID-19 Cohort (IMPACC) study, who were followed prospectively for twelve months. We reveal significant reactivation of Herpesviridae , Enteroviridae , and Anelloviridae families during acute stage of COVID-19 (0-40 days post- hospitalization), each exhibiting distinct temporal dynamics. We also show that viral reactivation correlated with COVID-19 severity, demographic characteristics, and clinical outcomes, including mortality. Integration of cytokine profiling, cellular immunophenotyping, metabolomics, transcriptomics, and proteomics demonstrated virus-specific host responses, including elevated pro-inflammatory cytokines (e.g. IL-6, CXCL10, and TNF), increased activated CD4+ and CD8+ T-cells, and upregulation of cellular replication genes, independent of COVID-19 severity and SARS-CoV-2 viral load. Notably, persistent Anelloviridae reactivation during convalescence (≥3 months post-hospitalization) was associated with Post-Acute Sequelae of COVID-19 (PASC) symptoms, particularly physical function and fatigue. Our findings highlight a remarkable prevalence and potential impact of chronic viral reactivation on host responses and clinical outcomes during acute COVID-19 and long term PASC sequelae. Our data provide novel immune, transcriptomic, and metabolomic biomarkers of viral reactivation that may inform novel approaches to prognosticate, prevent, or treat acute COVID- 19 and PASC.PMID:39605478 | PMC:PMC11601417 | DOI:10.1101/2024.11.14.622799
Adaptations in gut Bacteroidales facilitate stable co-existence with their lytic bacteriophages
bioRxiv [Preprint]. 2024 Nov 17:2024.11.17.624012. doi: 10.1101/2024.11.17.624012.ABSTRACTBACKGROUND: Bacteriophages (phages) and bacteria within the gut microbiome persist in long-term stable coexistence. These interactions are driven by eco-evolutionary dynamics, where bacteria employ a variety of mechanisms to evade phage infection, while phages rely on counterstrategies to overcome these defences. Among the most abundant phages in the gut are the crAss-like phages that infect members of the Bacteroidales, in particular Bacteroides . In this study, we explored some of the mechanisms enabling the co-existence of four phage-Bacteroidales host pairs in vitro using a multi-omics approach (transcriptomics, proteomics and metabolomics). These included three Bacteroides species paired with three crAss-like phages ( Bacteroides intestinalis and ϕcrAss001, Bacteroides xylanisolvens and ϕcrAss002, and an acapsular mutant of Bacteroides thetaiotaomicron with DAC15), and Parabacteroides distasonis paired with the siphovirus ϕPDS1.RESULTS: We show that phase variation of individual capsular polysaccharides (CPSs) is the primary mechanism promoting phage co-existence in Bacteroidales, but this is not the only strategy. Alternative resistance mechanisms, while potentially less efficient than CPS phase variation, can be activated to support bacterial survival by regulating gene expression and resulting in metabolic adaptations, particularly in amino acid degradation pathways. These mechanisms, also likely regulated by phase variation, enable bacterial populations to persist in the presence of phages, and vice versa . An acapsular variant of B. thetaiotaomicron demonstrated broader transcriptomic, proteomic, and metabolomic changes, supporting the involvement of additional resistance mechanisms beyond CPS variation.CONCLUSIONS: This study advances our understanding of long-term phage-host interaction, offering insights into the long-term persistence of crAss-like phages and extending these observations to other phages, such as ϕPDS1. Knowledge of the complexities of phage-bacteria interactions is essential for designing effective phage therapies and improving human health through targeted microbiome interventions.PMID:39605433 | PMC:PMC11601342 | DOI:10.1101/2024.11.17.624012
MAT2a and AHCY inhibition disrupts antioxidant metabolism and reduces glioblastoma cell survival
bioRxiv [Preprint]. 2024 Nov 24:2024.11.23.624981. doi: 10.1101/2024.11.23.624981.ABSTRACTGlioblastoma (GBM) is a highly aggressive primary malignant adult brain tumor that inevitably recurs with a fatal prognosis. This is due in part to metabolic reprogramming that allows tumors to evade treatment. We therefore must uncover the pathways mediating these adaptations to develop novel and effective treatments. We searched for genes that are essential in GBM cells as measured by a whole-genome pan-cancer CRISPR screen available from DepMap and identified the methionine metabolism genes MAT2A and AHCY . We conducted genetic knockdown, evaluated mitochondrial respiration, and performed targeted metabolomics to study the function of these genes in GBM. We demonstrate that MAT2A or AHCY knockdown induces oxidative stress, hinders cellular respiration, and reduces the survival of GBM cells. Furthermore, selective MAT2a or AHCY inhibition reduces GBM cell viability, impairs oxidative metabolism, and changes the metabolic profile of these cells towards oxidative stress and cell death. Mechanistically, MAT2a or AHCY regulates spare respiratory capacity, the redox buffer cystathionine, lipid and amino acid metabolism, and prevents DNA damage in GBM cells. Our results point to the methionine metabolic pathway as a novel vulnerability point in GBM.SIGNIFICANCE: We demonstrated that methionine metabolism maintains antioxidant production to facilitate pro-tumorigenic ROS signaling and GBM tumor cell survival. Importantly, targeting this pathway in GBM can potentially reduce tumor growth and improve survival in patients.PMID:39605416 | PMC:PMC11601785 | DOI:10.1101/2024.11.23.624981
Serum metabolome profiling in patients with mild cognitive impairment reveals sex differences in lipid metabolism
bioRxiv [Preprint]. 2024 Nov 13:2024.11.11.623108. doi: 10.1101/2024.11.11.623108.ABSTRACTAlzheimer's disease (AD) affects more women than men. Although women live longer than men, it is not longevity alone, but other factors, including metabolic changes, that contribute to the higher risk of AD in women. Metabolic pathways have been implicated in AD progression, but studies to date examined targeted pathways, leaving many metabolites unmeasured. Sex is often a neglected biological variable, and most metabolomic studies were not designed to investigate sex differences in metabolomic profiles. Here, we performed untargeted metabolomic profiling of sera from male and female patients with mild cognitive impairment (MCI), a common precursor to AD, and matched controls. We discovered significant metabolic changes in individuals with MCI, and found several pathways that were strongly associated with sex. Peptide energy metabolism demonstrated sexual dimorphism. Lipid pathways exhibited the strongest differences between female and male MCI patients, including specific phosphatidylcholine lipids, lysophospholipids, long-chain fatty acids, and monoacylglycerols. 1-palmitoleoyl glycerol and 1-arachidonoyl glycerol were higher in female MCI subjects than in male MCI subjects with no differences between control males and females. Conversely, specific dicarboxylic fatty acids were lower in female MCI subjects than male MCI subjects. In cultured astrocytes, 1-arachidonoyl glycerol promoted phosphorylation of the transcriptional regulator sphingosine kinase 2, which was inhibited by the transient receptor potential vanilloid 1 receptor antagonists, as well as chromatin remodelling. Overall, we identified novel sex-specific metabolites in MCI patients that could serve as biomarkers of MCI in both sexes, help further define AD etiology, and reveal new potential prevention strategies for AD.HIGHLIGHTS: Individuals with MCI experience significant metabolic changes.Lipid pathways demonstrated the strongest sexual dimorphism in MCI.1-monoacylglycerols showed a robust sex association, being higher in MCI females.Sex-specific metabolites may be MCI biomarkers in each sex.PMID:39605322 | PMC:PMC11601308 | DOI:10.1101/2024.11.11.623108
Mechanism of jianxin granules in the treatment of heart failure based on proteomics and metabolomics
Chin Med. 2024 Nov 28;19(1):165. doi: 10.1186/s13020-024-01009-6.ABSTRACTBACKGROUND: Heart failure (HF) is associated with high mortality and rehospitalization rates, highlighting the need for novel therapeutic approaches. Jianxin (JX) granules, a Traditional Chinese Medicine formulation, have been patented for the treatment of HF. However, the specific therapeutic effects and underlying mechanisms of JX granules have not been fully elucidated. This study aimed at investigating the effects and mechanism of JX granules in the treatment of HF based on proteomics and metabolomic profiling.METHODS: HF model was established in rats by ligation of left coronary artery. The successfully modeled rats were randomly divided into three groups: the model group, the JX granules group, and Sacubitril/Valsartan (S/V) group. Four weeks after treatment, left ventricular (LV) function was evaluated via echocardiography. LV fibrosis and apoptosis were examined through histological analyses, while mitochondrial morphology was assessed using transmission electron microscopy. Quantitative assessment of oxidative stress was also conducted. Proteomics was used to identify the differentially expressed proteins and potential pathways. Metabolomics was utilized to elucidate the variations in metabolism. Then western blotting and in vitro analyses were performed.RESULTS: A rat model of HF was established, evidenced by a decrease in left ventricular ejection fraction (LVEF), stroke volume (SV), and left ventricular fractional shortening (LVFS), alongside diminished adenosine triphosphate (ATP) content, elevated oxidative stress, augmented apoptosis, and disrupted pyruvate metabolism. Treatment with JX granules ameliorated these effects, improving systolic function, reducing ventricular chamber size, and increasing LVEF, SV, and LVFS, as assessed by echocardiography. Additionally, JX granules attenuated cardiac fibrosis and improved mitochondrial structure, as evidenced by less vacuolation and clearer mitochondrial cristae, when compared to the model group. The treatment also regulated apoptosis-related protein expression, partially reversing the increase in cleaved Caspase-9, cleaved Caspase-3, and Bax and the suppression of Bcl-2 observed in the heart failure rats. All of these effects were similar to S/V. Proteomic and metabolomic analyses identified key differential genes, such as triosephosphate isomerase 1 (TPI1), lactate dehydrogenase B (LDHB), pyruvate kinase M (PKM), protein kinase B (Akt), Pyruvate Dehydrogenase Beta (PDHB) and lactate dehydrogenase A (LDHA), as well as vital pathways including carbon metabolism, the PI3K-Akt signaling pathway, pyruvate metabolism, and HIF-1α signaling pathway. Moreover, JX granules mitigated oxidative stress, inhibited apoptosis, and activated Akt in H9c2 cells exposed to angiotensin II, which could be reversed by the PI3K inhibitor LY294002.CONCLUSION: JX granules improve HF in parallel to the efficacy of S/V, at least in part, through enhancing pyruvate metabolism, inhibiting oxidative stress and activating PI3K/Akt pathway.PMID:39605071 | DOI:10.1186/s13020-024-01009-6
Even moderate liver fat accumulation below conventional fatty liver cutoffs is linked to multiple metabolomic alterations and gestational dysglycemia in Asian women of reproductive age
BMC Med. 2024 Nov 27;22(1):561. doi: 10.1186/s12916-024-03779-0.ABSTRACTBACKGROUND: It is not clear if conventional liver fat cutoff of 5.56% weight which has been used for identifying fatty liver in western populations is also applicable for Asians. In Asian women of reproductive age, we evaluate the optimum metabolic syndrome (MetS)-linked liver fat cutoff, the specific metabolomic alterations apparent at this cutoff, as well as prospective associations of preconception liver fat levels with gestational dysglycemia.METHODS: Liver fat (measured by magnetic resonance spectroscopy), MetS, and nuclear magnetic resonance (NMR)-based plasma metabolomic profiles were assessed in 382 Asian women, who were planning to conceive. Ninety-eight women went on to become pregnant and received an oral glucose tolerance test at week 26 of gestation.RESULTS: The optimum liver fat cutoff for diagnosing MetS was 2.07%weight. Preconception liver fat was categorized into Low (liver fat < 2.07%), Moderate (2.07% ≤ liver fat < 5.56%), and High (liver fat ≥ 5.56%) groups. Individual MetS traits showed worsening trends, going from Low to Moderate to High groups. Multiple plasma metabolomic alterations, previously linked to incident type 2 diabetes (T2D), were already evident in the Moderate group (adjusted for ethnicity, age, parity, educational attainment, and BMI). Both a cross-sectional multi-metabolite score for incident T2D and mid-gestational glucose area under the curve showed increasing trends, going from Low to Moderate to High groups (p < 0.001 for both). Gestational diabetes incidence was 2-fold (p = 0.23) and 7-fold (p < 0.001) higher in the Moderate and High groups relative to the Low group.CONCLUSIONS: In Asian women of reproductive age, moderate liver fat accumulation below the conventional fatty liver cutoff was not metabolically benign and was linked to gestational dysglycemia. The newly derived cutoff can aid in screening individuals before adverse metabolic phenotypes have consolidated, which provides a longer window for preventive strategies.PMID:39605006 | DOI:10.1186/s12916-024-03779-0
Gut microbiota analysis and LC-MS-based metabolomics to investigate AMPK/NF-kappaB regulated by Clostridium butyricum in the treatment of acute pancreatitis
J Transl Med. 2024 Nov 27;22(1):1072. doi: 10.1186/s12967-024-05764-w.ABSTRACTBACKGROUND: Acute pancreatitis (AP) is an inflammatory condition with potentially life-threatening complications. This study investigates the therapeutic potential of Clostridium butyricum for modulating the inflammatory cascade through the AMPK/NF-κB signaling pathway, focusing on inflammation induced by AP. LC-MS analysis of serum samples from AP patients highlighted the regulation of lipid metabolism and inflammation, and found that metabolites involved in the inhibition of NF-κB phosphorylation and the AMPK activation pathway were downregulated. We hypothesized that pre-administration of Clostridium butyricum and its culture supernatant could mitigate AP-induced damage by modulating the AMPK/NF-κB pathway.METHODS: Lipopolysaccharide (LPS)-induced cell inflammation models. LPS combined with CAE induced acute pancreatitis in mice. We divided mice into four groups: Con, AP, AP + C.Buty (AP with Clostridium butyricum treatment), and AP + CFS (AP with culture supernatant treatment). Analyses were performed using WB, RT-qPCR, Elisa, flow cytometry, IHC, and HE, respectively.RESULTS: Our study shows that CFS can reduce the apoptosis of LPS-induced cellular inflammation and reduce the release of LPS-induced cytoinflammatory factors through the AMPK/NF-κB pathway in vitro. In vivo, Clostridium butyricum and its supernatant significantly reduced inflammatory markers, and corrected histopathological alterations in AP mice. Gut microbiota analysis further supported these results, showing that Clostridium butyricum and its supernatant could restore the balance of intestinal flora disrupted by AP.CONCLUSIONS: Mechanistically, our results indicated that the therapeutic effects of Clostridium butyricum are mediated through the activation of AMPK, leading to the inhibition of the NF-κB pathway, thereby reducing the production of pro-inflammatory cytokines. Clostridium butyricum and its culture supernatant exert a protective effect against AP-induced damage by modulating the AMPK/NF-κB signaling pathway. Future studies will further elucidate the molecular mechanisms underlying the beneficial effects of Clostridium butyricum in AP and explore its clinical applicability in human subjects.PMID:39604956 | DOI:10.1186/s12967-024-05764-w
<em>In vivo</em> mechanism of the interaction between trimethylamine lyase expression and glycolytic pathways
Food Funct. 2024 Nov 28. doi: 10.1039/d4fo03809f. Online ahead of print.ABSTRACTRecent studies confirmed that host-gut microbiota interactions modulate disease-linked metabolite TMA production via TMA lyase. However, microbial enzyme production mechanisms remain unclear. In the present study, we investigated the impact of dietary and intervention factors on gut microbiota, microbial gene expression, and the interplay between TMA lyase and glycolytic pathways in mice. Using 16S rRNA gene sequencing, metagenomics, and metabolomics, the gut microbiota composition and microbial functional gene expression profiles related to TMA lyase and glycolytic enzymes were determined. The results revealed that distinct diets and intervention factors altered gut microbiota, gene expression, and metabolites linked to glycine metabolism and glycolysis. Notably, an arabinoxylan-rich diet suppressed genes linked to choline, glycine, glycolysis, and TMA lyase, favoring glycine utilization via pyruvate pathways. Glycolytic inhibitors amplified these effects, mainly inhibiting pyruvate kinase. Our findings underscored the crosstalk between TMA lyase and glycolytic pathways, regulating glycine levels, and suggested avenues for targeted interventions and personalized diets to curb choline TMA lyase production.PMID:39604809 | DOI:10.1039/d4fo03809f
Carnitine Metabolite as a Potential Circulating Biomarker for Sarcopenia in Men
Endocrinol Metab (Seoul). 2024 Nov 28. doi: 10.3803/EnM.2024.2117. Online ahead of print.ABSTRACTBACKGROUND: Sarcopenia, a multifactorial disorder involving metabolic disturbance, suggests potential for metabolite biomarkers. Carnitine (CN), essential for skeletal muscle energy metabolism, may be a candidate biomarker. We investigated whether CN metabolites are biomarkers for sarcopenia.METHODS: Associations between the CN metabolites identified from an animal model of sarcopenia and muscle cells and sarcopenia status were evaluated in men from an age-matched discovery (72 cases, 72 controls) and a validation (21 cases, 47 controls) cohort.RESULTS: An association between CN metabolites and sarcopenia showed in mouse and cell studies. In the discovery cohort, plasma C5-CN levels were lower in sarcopenic men (P=0.005). C5-CN levels in men tended to be associated with handgrip strength (HGS) (P=0.098) and were significantly associated with skeletal muscle mass (P=0.003). Each standard deviation increase in C5-CN levels reduced the odds of low muscle mass (odd ratio, 0.61; 95% confidence interval [CI], 0.42 to 0.89). The area under the receiver operating characteristic curve (AUROC) of CN score using a regression equation of C5-CN levels, for sarcopenia was 0.635 (95% CI, 0.544 to 0.726). In the discovery cohort, addition of CN score to HGS significantly improved AUROC from 0.646 (95% CI, 0.575 to 0.717; HGS only) to 0.727 (95% CI, 0.643 to 0.810; P=0.006; HGS+CN score). The improvement was confirmed in the validation cohort (AUROC=0.563; 95% CI, 0.470 to 0.656 for HGS; and AUROC=0.712; 95% CI, 0.569 to 0.855 for HGS+CN score; P=0.027).CONCLUSION: C5-CN, indicative of low muscle mass, is a potential circulating biomarker for sarcopenia in men. Further studies are required to confirm these results and explore sarcopenia-related metabolomic changes.PMID:39604802 | DOI:10.3803/EnM.2024.2117
Integrating proteomics and metabolomics to evaluate impact of semen collection techniques on the quality and cryotolerance of goat semen
Sci Rep. 2024 Nov 27;14(1):29489. doi: 10.1038/s41598-024-80556-2.ABSTRACTResults of artificial insemination (AI) are affected by changes in sperm quality and the function throughout collection and preservation procedures. Proteome and metabolome alterations of sperm treated with the different procedures in goat, however, aren't fully understood. To this end, we sought to investigate the impacts of rectal probe electrostimulation (EE) and artificial vagina (AV) semen collection methods on the quality and the cryotolerance of goat sperm, with additional focus on proteomic and metabolomic analyses. Semen samples were collected from Yunshang black goats and categorized into four groups: fresh sperm collected via AV (XAZ), fresh sperm collected via EE (XEZ), frozen sperm post-AV collection (DAZ) and frozen sperm post-EE collection (DEZ). Four comparisons (XAZ vs. XEZ, DAZ vs. XAZ, DEZ vs. XEZ, DAZ vs. DEZ) were performed, respectively. This study first evaluated sperm motility, acrosome integrity, plasma membrane integrity, mitochondrial activity, and reactive oxygen species (ROS) levels. The results indicated that there were no significant differences in fresh sperm quality parameters between the EE and AV methods. However, notable differences emerged post-cryopreservation. Specifically, the AV method proved more advantageous in preserving the motility, integrities of acrosome and plasma membrane, mitochondrial activity of frozen sperm compared to the EE method. Through the multi-omics approaches, a total of 210 differentially abundant proteins (DAPs) related to sperm characteristics and function were identified across the four comparations. Moreover, 32 differentially abundant metabolites (DAMs) were detected. Comprehensive bioinformatics analysis underscored significant molecular pathways in the co-enrichment of DAPs and DAMs, particularly focusing on the citrate cycle, ROS, oxidative phosphorylation, and glycine, serine, and threonine metabolism etc. We elucidated the differential impacts of AV and EE collection methods on the quality and cryotolerance of goat semen from omics perspectives, which offer a critical foundation for further exploration into optimizing semen collection and cryopreservation techniques in goat breeding program.PMID:39604559 | DOI:10.1038/s41598-024-80556-2
Development of metabolic signatures of plant-rich dietary patterns using plant-derived metabolites
Eur J Nutr. 2024 Nov 28;64(1):29. doi: 10.1007/s00394-024-03511-x.ABSTRACTBACKGROUND: Diet is an important modifiable lifestyle factor for human health, and plant-rich dietary patterns are associated with lower risk of non-communicable diseases in numerous studies. However, objective assessment of plant-rich dietary exposure in nutritional epidemiology remains challenging.OBJECTIVES: This study aimed to develop and evaluate metabolic signatures of the most widely used plant-rich dietary patterns using a targeted metabolomics method comprising 108 plant food metabolites.METHODS: A total of 218 healthy participants were included, aged 51.5 ± 17.7 years, with 24 h urine samples measured using ultra-high-performance liquid chromatography-mass spectrometry. The validation dataset employed three sample types to test the robustness of the signature, including 24 h urine (n = 88), plasma (n = 195), and spot urine (n = 198). Adherence to the plant-rich diet was assessed using a priori plant-rich dietary patterns calculated using Food Frequency Questionnaires. A combination of metabolites evaluating the adherence to a specific diet was identified as metabolic signature. We applied linear regression analysis to select the metabolites significantly associated with dietary patterns (adjusting energy intake), and ridge regression to estimate penalized weights of each candidate metabolite. The correlation between metabolic signature and the dietary pattern was assessed by Spearman analysis (FDR < 0.05).RESULTS: The metabolic signatures consisting of 42, 22, 35, 15, 33, and 33 predictive metabolites across different subclasses were found to be associated with adherence to Amended Mediterranean Score (A-MED), Original MED (O-MED), Dietary Approaches to Stop Hypertension (DASH), Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND), healthy Plant-based Diet Index (hPDI) and unhealthy PDI (uDPI), respectively. The overlapping and distinct predictive metabolites across six dietary patterns predominantly consisted of phenolic acids (n = 38), including 14 cinnamic acids, 14 hydroxybenzoic acids, seven phenylacetic acids, and three hippuric acids. Six metabolites were included in all signatures, including two lignans: enterolactone-glucuronide, enterolactone-sulfate, and four phenolic acids: cinnamic acid, cinnamic acid-4'-sulfate, 2'-hydroxycinnamic acid, and 4-methoxybenzoic acid-3-sulfate. The established signatures were robustly correlated with dietary patterns in the validation datasets (r = 0.13-0.40, FDR < 0.05).CONCLUSIONS: We developed and evaluated a set of metabolic signatures that reflected the adherence to plant-rich dietary patterns, suggesting the potential of these signatures to serve as an objective assessment of free-living eating habits.PMID:39604558 | DOI:10.1007/s00394-024-03511-x
Exploring molecular mechanisms of postoperative delirium through multi-omics strategies in plasma exosomes
Sci Rep. 2024 Nov 27;14(1):29466. doi: 10.1038/s41598-024-80865-6.ABSTRACTCurrently, the diagnosis of delirium is solely based on clinical observation, lacking objective diagnostic tools, and the regulatory networks and pathological mechanisms behind it are not yet fully understood. Exosomes have garnered considerable interest as potential biomarkers for a variety of illnesses. This research aimed to delineate both the proteomic and metabolomic landscapes inherent to exosomes, assessing their diagnostic utility in postoperative delirium (POD) and understanding the underlying pathophysiological frameworks. Integrated analyses of proteomics and metabolomics were conducted on exosomes derived from plasma of individuals from both the non-postoperative delirium (NPOD) control group and the POD group. Subsequently, the study utilized the Connectivity Map (CMap) methodology for the identification of promising small-molecule drugs and carried out molecular docking assessments to explore the binding affinities with the enzyme MMP9 of these identified molecules. We identified significant differences in exosomal metabolites and proteins between the POD and control groups, highlighting pathways related to neuroinflammation and blood-brain barrier (BBB) integrity. Our CMap analysis identified potential small-molecule therapeutics, and molecular docking studies revealed two compounds with high affinity to MMP9, suggesting a new therapeutic avenue for POD. This study highlights MMP9, TLR2, ICAM1, S100B, and glutamate as key biomarkers in the pathophysiology of POD, emphasizing the roles of neuroinflammation and BBB integrity. Notably, molecular docking suggests mirin and orantinib as potential inhibitors targeting MMP9, providing new therapeutic avenues. The findings broaden our understanding of POD mechanisms and suggest targeted strategies for its management, reinforcing the importance of multidimensional biomarker analysis and molecular targeting in POD intervention.PMID:39604493 | DOI:10.1038/s41598-024-80865-6
Metabolic reprogramming in saliva of mice treated with the environmental and tobacco carcinogen dibenzo[def, p]chrysene
Sci Rep. 2024 Nov 27;14(1):29517. doi: 10.1038/s41598-024-80921-1.ABSTRACTThe goal of this study is to develop a non-invasive approach for early detection of oral squamous cell carcinoma (OSCC) using our established mouse model that faithfully recapitulates the human disease. We present for the first time a comparative metabolomic profiling of saliva samples of the tobacco smoke constituent, dibenzo[def, p]pyrene, (DB[a, l]P) vs. DMSO (control)-treated mice using an established and highly sensitive LC-MS/MS approach. DB[a, l]P was administered by topical application into the mouse oral cavity (25 µmol, 3x week for 6 weeks) and saliva was collected 24 h after the last dose of carcinogen administration. Using an untargeted metabolomics approach (negative and positive modes), we found that DB[a, l]P differentially altered several metabolites known to be involved in the carcinogenesis process when compared to DMSO. Of particular significance, we found that DB[a, l]P significantly enriched the levels of phosphatidic acid, known to bind and activate mTORC which can enhance proliferation and promote carcinogenesis. Pathway enrichment analysis revealed that DB[a, l]P altered two major lipid metabolism pathways (phospholipid biosynthesis and glycerolipid metabolism). Collectively, our results using saliva as a safe and non-invasive approach, provide additional mechanistic insights on DB[a, l]P-induced OSCC and potential biomarkers for early detection and an opportunity for cancer interception via reprogramming lipid metabolism.PMID:39604478 | DOI:10.1038/s41598-024-80921-1
Glycosphingolipids and their impact on platelet activity in a murine model of fabry disease
Sci Rep. 2024 Nov 27;14(1):29488. doi: 10.1038/s41598-024-80633-6.ABSTRACTFabry disease is an X-linked lysosomal storage disorder caused by deficiency of the lysosomal enzyme ⍺-galactosidase-A (⍺-Gal A), resulting in widespread accumulation of terminal galactose-containing glycosphingolipids (GSLs) and the impairment of multiple organ systems. Thrombotic events are common in Fabry patients, with strokes and heart attacks being significant contributors to a shortened lifespan in patients of both genders. Previously, we developed an ⍺-Gal A-knockout (KO) murine model that recapitulates most Fabry symptomologies and demonstrated that platelets from KO males become sensitized to agonist-mediated activation. In the current report, we used mass spectrometry, platelet-based assays and histology to define further the mechanisms linking GSL accumulation with thrombotic phenotypes in both sexes. Sera and platelets from ⍺-Gal A-KO females have elevated levels of Fabry-associated GSLs relative to wild-type females, but accumulated less of these GSLs than KO males. Correspondingly, KO females demonstrate a less severe thrombotic phenotypes than KO males. Notably, treatment of platelets from wild-type animals with globotriaosylceramide (Gb3) increased baseline platelet activation and aggregation. In contrast, several control GSLs did not stimulate platelet responses. These data suggest that chronically high concentrations of the Fabry-associated GSL, Gb3, contributes to the prothrombotic phenotypes experienced by Fabry patients by directly stimulating platelet activation.PMID:39604471 | DOI:10.1038/s41598-024-80633-6