Integrative Molecular Phenotyping
INTEGRATIVE MOLECULAR
PHENOTYPING
WHEELOCK LABORATORY
DEPARTMENT OF MEDICAL
BIOCHEMISTRY AND BIOPHYSICS
WHEELOCK LABORATORY
DEPARTMENT OF MEDICAL
BIOCHEMISTRY AND BIOPHYSICS
WHEELOCK LABORATORY
DEPARTMENT OF MEDICAL
BIOCHEMISTRY AND BIOPHYSICS
WHEELOCK LABORATORY
DEPARTMENT OF MEDICAL
BIOCHEMISTRY AND BIOPHYSICS
WHEELOCK LABORATORY
DEPARTMENT OF MEDICAL
BIOCHEMISTRY AND BIOPHYSICS
WHEELOCK LABORATORY

PubMed

Metabolomics and Transcriptomics Analyses Reveals the Molecular Regulatory Mechanisms of Walnut (<em>Juglans regia</em> L.) Embryos in Response to Shade Treatment

Fri, 14/07/2023 - 12:00
Int J Mol Sci. 2023 Jun 29;24(13):10871. doi: 10.3390/ijms241310871.ABSTRACTThe walnut is an important nut that has numerous uses worldwide. However, due to dwarf and close plantation methods as well as continuous cloudy or rainy days that occur during periods of walnut oil accumulation, the walnut fruit exhibits varying degrees of stress under low-light conditions. However, the effects of shade on metabolites and genes in walnut embryos remain unclear in the literature. The purpose of this study is to investigate the lipid biosynthesis process that occurs in walnut embryos under shade treatment via the use of metabolomics and transcriptomics analyses. The results indicate that the oil content decreases significantly under shaded conditions, while the protein content increases significantly. The expression levels of fatty acid desaturase 2 (FAD2) and stearoyl-ACP-desaturase (SAD) involved in the lipid biosynthesis mechanism were significantly reduced in the shaded group, which resulted in reductions in oleic (C18:1), linoleic (C18:2), and α-linolenic (C18:3) acids. The reduced oil content was consistent with the downregulation of genes associated with the lipid biosynthesis mechanism. In the amino acid biosynthesis process, the upregulated cysteine synthase (cscK) and anthranilate synthase beta subunit 2 (trpG) genes promoted the accumulation of L-aspartic acid and L-citrulline. The increase in protein content was consistent with the upregulation of genes related to amino acid biosynthesis. Thus, our study provides new insights into the regulatory mechanisms of shade underlying overall walnut fruit quality.PMID:37446044 | DOI:10.3390/ijms241310871

Metabolic Dysregulation Explains the Diverse Impacts of Obesity in Males and Females with Gastrointestinal Cancers

Fri, 14/07/2023 - 12:00
Int J Mol Sci. 2023 Jun 29;24(13):10847. doi: 10.3390/ijms241310847.ABSTRACTThe prevalence of obesity, defined as the body mass index (BMI) ≥ 30 kg/m2, has reached epidemic levels. Obesity is associated with an increased risk of various cancers, including gastrointestinal ones. Recent evidence has suggested that obesity disproportionately impacts males and females with cancer, resulting in varied transcriptional and metabolic dysregulation. This study aimed to elucidate the differences in the metabolic milieu of adenocarcinomas of the gastrointestinal (GI) tract both related and unrelated to sex in obesity. To demonstrate these obesity and sex-related effects, we utilized three primary data sources: serum metabolomics from obese and non-obese patients assessed via the Biocrates MxP Quant 500 mass spectrometry-based kit, the ORIEN tumor RNA-sequencing data for all adenocarcinoma cases to assess the impacts of obesity, and publicly available TCGA transcriptional analysis to assess GI cancers and sex-related differences in GI cancers specifically. We applied and integrated our unique transcriptional metabolic pipeline in combination with our metabolomics data to reveal how obesity and sex can dictate differential metabolism in patients. Differentially expressed genes (DEG) analysis of ORIEN obese adenocarcinoma as compared to normal-weight adenocarcinoma patients resulted in large-scale transcriptional reprogramming (4029 DEGs, adj. p < 0.05 and |logFC| > 0.58). Gene Set Enrichment and metabolic pipeline analysis showed genes enriched for pathways relating to immunity (inflammation, and CD40 signaling, among others) and metabolism. Specifically, we found alterations to steroid metabolism and tryptophan/kynurenine metabolism in obese patients, both of which are highly associated with disease severity and immune cell dysfunction. These findings were further confirmed using the TCGA colorectal adenocarcinoma (CRC) and esophageal adenocarcinoma (ESCA) data, which showed similar patterns of increased tryptophan catabolism for kynurenine production in obese patients. These patients further showed disparate alterations between males and females when comparing obese to non-obese patient populations. Alterations to immune and metabolic pathways were validated in six patients (two obese and four normal weight) via CD8+/CD4+ peripheral blood mononuclear cell RNA-sequencing and paired serum metabolomics, which showed differential kynurenine and lipid metabolism, which corresponded with altered T-cell transcriptome in obese populations. Overall, obesity is associated with differential transcriptional and metabolic programs in various disease sites. Further, these alterations, such as kynurenine and tryptophan metabolism, which impact both metabolism and immune phenotype, vary with sex and obesity together. This study warrants further in-depth investigation into obesity and sex-related alterations in cancers that may better define biomarkers of response to immunotherapy.PMID:37446025 | DOI:10.3390/ijms241310847

The Regulatory Network of Sweet Corn (<em>Zea mays</em> L.) Seedlings under Heat Stress Revealed by Transcriptome and Metabolome Analysis

Fri, 14/07/2023 - 12:00
Int J Mol Sci. 2023 Jun 29;24(13):10845. doi: 10.3390/ijms241310845.ABSTRACTHeat stress is an increasingly significant abiotic stress factor affecting crop yield and quality. This study aims to uncover the regulatory mechanism of sweet corn response to heat stress by integrating transcriptome and metabolome analyses of seedlings exposed to normal (25 °C) or high temperature (42 °C). The transcriptome results revealed numerous pathways affected by heat stress, especially those related to phenylpropanoid processes and photosynthesis, with 102 and 107 differentially expressed genes (DEGs) identified, respectively, and mostly down-regulated in expression. The metabolome results showed that 12 or 24 h of heat stress significantly affected the abundance of metabolites, with 61 metabolites detected after 12 h and 111 after 24 h, of which 42 metabolites were detected at both time points, including various alkaloids and flavonoids. Scopoletin-7-o-glucoside (scopolin), 3-indolepropionic acid, acetryptine, 5,7-dihydroxy-3',4',5'-trimethoxyflavone, and 5,6,7,4'-tetramethoxyflavanone expression levels were mostly up-regulated. A regulatory network was built by analyzing the correlations between gene modules and metabolites, and four hub genes in sweet corn seedlings under heat stress were identified: RNA-dependent RNA polymerase 2 (RDR2), UDP-glucosyltransferase 73C5 (UGT73C5), LOC103633555, and CTC-interacting domain 7 (CID7). These results provide a foundation for improving sweet corn development through biological intervention or genome-level modulation.PMID:37446023 | DOI:10.3390/ijms241310845

Integration of Transcriptomic and Metabolomic Profiles Provides Insights into the Influence of Nitrogen on Secondary Metabolism in <em>Fusarium sacchari</em>

Fri, 14/07/2023 - 12:00
Int J Mol Sci. 2023 Jun 29;24(13):10832. doi: 10.3390/ijms241310832.ABSTRACTNitrogen availability might play an essential role in plant diseases by enhancing fungal cell growth and influencing the expression of genes required for successful pathogenesis. Nitrogen availability could modulate secondary metabolic pathways as evidenced by the significant differential expression of several core genes involved in mycotoxin biosynthesis and genes encoding polyketide synthase/nonribosomal peptide synthetases, cytochrome P450 and carbohydrate-active enzymes in Fusarium sacchari, grown on different nitrogen sources. A combined analysis was carried out on the transcript and metabolite profiles of regulatory metabolic processes and the virulence of Fusarium sacchari grown on various nitrogen sources. The nitrogen regulation of the gibberellin gene cluster included the metabolic flux and multiple steps of gibberellin synthesis. UHPLC-MS/MS-based metabolome analysis revealed the coordination of these related transcripts and the accumulation of gibberellin metabolites. This integrated analysis allowed us to uncover additional information for a more comprehensive understanding of biological events relevant to fungal secondary metabolic regulation in response to nitrogen availability.PMID:37446015 | DOI:10.3390/ijms241310832

Transcriptomic and Metabolomic Analyses Provide Insights into the Pathogenic Mechanism of the Rice False Smut Pathogen <em>Ustilaginoidea virens</em>

Fri, 14/07/2023 - 12:00
Int J Mol Sci. 2023 Jun 28;24(13):10805. doi: 10.3390/ijms241310805.ABSTRACTRice false smut, caused by the fungal pathogen Ustilaginoidea virens, is a worldwide rice fungal disease. However, the molecular mechanism of the pathogenicity of the fungus U. virens remains unclear. To understand the molecular mechanism of pathogenesis of the fungus U. virens, we performed an integrated analysis of the transcriptome and metabolome of strongly (S) and weakly (W) virulent strains both before and after the infection of panicles. A total of 7932 differential expressed genes (DEGs) were identified using transcriptome analysis. Gene ontology (GO) and metabolic pathway enrichment analysis indicated that amino acid metabolism, autophagy-yeast, MAPK signaling pathway-yeast, and starch and sucrose metabolism were closely related to the pathogenicity of U. virens. Genes related to pathogenicity were significantly upregulated in the strongly virulent strain, and were ATG, MAPK, STE, TPS, and NTH genes. However, genes involved in the negative regulation of pathogenesis were significantly downregulated and contained TOR kinase, TORC1, and autophagy-related protein genes. Metabolome analysis identified 698 differentially accumulated metabolites (DAMs), including 13 categories of organic acids and derivatives, lipids and lipid-like molecules, organoheterocyclic compounds. The significantly enriched pathways of DAMs mainly included amino acids and carbohydrates, and they accumulated after infection by the S strain. To understand the relevance of DEGs and DAMs in the pathogenicity of U. virens, transcriptomic and metabolomic data were integrated and analyzed. These results further confirmed that the pathogenesis of U. virens was regulated by DEGs and DAMs related to these four pathways, involving arginine and proline metabolism, lysine biosynthesis, alanine, aspartate and glutamate metabolism, and starch and sugar metabolism. Therefore, we speculate that the pathogenicity of U. virens is closely related to the accumulation of amino acids and carbohydrates, and to the changes in the expression of related genes.PMID:37445981 | DOI:10.3390/ijms241310805

Integrating Microbiome Analysis, Metabolomics, Bioinformatics, and Histopathology to Elucidate the Protective Effects of Pomegranate Juice against Benzo-alpha-pyrene-Induced Colon Pathologies

Fri, 14/07/2023 - 12:00
Int J Mol Sci. 2023 Jun 27;24(13):10691. doi: 10.3390/ijms241310691.ABSTRACTPolycyclic aromatic hydrocarbons, e.g., benzo[a]pyrene (BaP), are common dietary pollutants with potential carcinogenic activity, while polyphenols are potential chemopreventive antioxidants. Although several health benefits are attributed to polyphenol-rich pomegranate, little is known about its interaction with BaP. This study integrates histochemical, microbiomic, and metabolomic approaches to investigate the protective effects of pomegranate juice from BaP-induced pathologies. To this end, 48 Sprague-Dawley rats received, for four weeks, either pomegranate, BaP, both, or neither (n = 12 rats per group). Whereas histochemical examination of the colon indicated tissue damage marked by mucin depletion in BaP-fed animals, which was partially restored by administration of pomegranate juice, the fecal microbiome and metabolome retained their resilience, except for key changes related to pomegranate and BaP biotransformation. Meanwhile, dramatic microbiome restructuring and metabolome shift were observed as a consequence of the elapsed time (age factor). Additionally, the analysis allowed a thorough examination of fecal microbiome-metabolome associations, which delineated six microbiome clusters (marked by a differential abundance of Lactobacillaceae and Prevotellaceae, Rumincococcaceae, and Erysipelotrichaceae) and two major metabolome clusters (a sugar- and amino-acids-dominated metabotype vs. a cluster of fatty acids and hydrocarbons), with sugar alcohols maintaining a unique signature. In conclusion, using paired comparisons to minimize inter-individual animal variations allowed the dissection of temporal vs. treatment-derived variations. Microbiome-metabolome association clusters may be further exploited for metabotype prediction and gut-health biomarker discovery.PMID:37445869 | DOI:10.3390/ijms241310691

Plasma Metabolomic Profiling after Feeding Dried Distiller's Grains with Solubles in Different Cattle Breeds

Fri, 14/07/2023 - 12:00
Int J Mol Sci. 2023 Jun 26;24(13):10677. doi: 10.3390/ijms241310677.ABSTRACTDried distiller's grains with solubles (DDGS) are rich in nutrients and can enhance animals' growth and immunity. However, there are few reports on the effects of a diet of DDGS on plasma metabolism and the related action pathways in domestic animals. In this study, groups of Guanling yellow cattle (GY) and Guanling crossbred cattle (GC) having a basal diet served as the control groups (GY-CG and GC-CG), and DDGS replacing 25% of the diet of GY and GC served as the replacement groups (GY-RG and GC-RG), with three cattle in each group. Plasma samples were prepared for metabolomic analysis. Based on multivariate statistical and univariate analyses, differential metabolites and metabolic pathways were explored. Twenty-nine significantly different metabolites (p < 0.05) were screened in GY-RG compared with those in GY-CG and were found to be enriched in the metabolic pathways, including choline metabolism in cancer, linolenic acid metabolism, and amino acid metabolism. Nine metabolites showed significant differences (p < 0.05) between GC-RG and GC-CG and were mainly distributed in the metabolic pathways of choline metabolism in cancer, glycerophospholipid metabolism, prostate cancer metabolism, and gonadotropin-releasing hormone (GnRH) secretion. These results suggest that a DDGS diet may promote healthy growth and development of experimental cattle by modulating these metabolic pathways. Our findings not only shed light on the nutritional effects of the DDGS diet and its underlying mechanisms related to metabolism but also provide scientific reference for the feed utilization of DDGS.PMID:37445854 | DOI:10.3390/ijms241310677

TCA cycle metabolites associated with adverse outcomes after acute coronary syndrome: mediating effect of renal function

Thu, 13/07/2023 - 12:00
Front Cardiovasc Med. 2023 Jun 27;10:1157325. doi: 10.3389/fcvm.2023.1157325. eCollection 2023.ABSTRACTAIMS: To examine relationships of tricarboxylic acid (TCA) cycle metabolites with risk of cardiovascular events and mortality after acute coronary syndrome (ACS), and evaluate the mediating role of renal function in these associations.METHODS: This is a prospective study performed among 309 ACS patients who were followed for a mean of 6.7 years. During this period 131 patients developed major adverse cardiovascular events (MACE), defined as the composite of myocardial infarction, hospitalization for heart failure, and all-cause mortality, and 90 deaths were recorded. Plasma concentrations of citrate, aconitate, isocitrate, succinate, malate, fumarate, α-ketoglutarate and d/l-2-hydroxyglutarate were quantified using LC-tandem MS. Multivariable Cox regression models were used to estimate hazard ratios, and a counterfactual-based mediation analysis was performed to test the mediating role of estimated glomerular filtration rate (eGFR).RESULTS: After adjustment for traditional cardiovascular risk factors and medications, positive associations were found between isocitrate and MACE (HR per 1 SD, 1.25; 95% CI: 1.03, 1.50), and between aconitate, isocitrate, d/l-2-hydroxyglutarate and all-cause mortality (HR per 1 SD, 1.41; 95% CI: 1.07, 1.84; 1.58; 95% CI: 1.23, 2.02; 1.38; 95% CI: 1.14, 1.68). However, these associations were no longer significant after additional adjustment for eGFR. Mediation analyses demonstrated that eGFR is a strong mediator of these associations.CONCLUSION: These findings underscore the importance of TCA metabolites and renal function as conjunctive targets in the prevention of ACS complications.PMID:37441709 | PMC:PMC10333508 | DOI:10.3389/fcvm.2023.1157325

Ascorbic acid induces MLC2v protein expression and promotes ventricular-like cardiomyocyte subtype in human induced pluripotent stem cells derived cardiomyocytes

Thu, 13/07/2023 - 12:00
Theranostics. 2023 Jul 3;13(11):3872-3896. doi: 10.7150/thno.80801. eCollection 2023.ABSTRACTIntroduction: The potentially unlimited number of cardiomyocyte (CMs) derived from human induced pluripotent stem cells (hiPSCs) in vitro facilitates high throughput applications like cell transplantation for myocardial repair, disease modelling, and cardiotoxicity testing during drug development. Despite promising progress in these areas, a major disadvantage that limits the use of hiPSC derived CMs (hiPSC-CMs) is their immaturity. Methods: Three hiPSC lines (PCBC-hiPSC, DP3-hiPSCs, and MLC2v-mEGFP hiPSC) were differentiated into CMs (PCBC-CMs, DP3-CMs, and MLC2v-CMs, respectively) with or without retinoic acid (RA). hiPSC-CMs were either maintained up to day 30 of contraction (D30C), or D60C, or purified using lactate acid and used for experiments. Purified hiPSC-CMs were cultured in basal maturation medium (BMM) or BMM supplemented with ascorbic acid (AA) for 14 days. The AA treated and non-treated hiPSC-CMs were characterized for sarcomeric proteins (MLC2v, TNNI3, and MYH7), ion channel proteins (Kir2.1, Nav1.5, Cav1.2, SERCA2a, and RyR), mitochondrial membrane potential, metabolomics, and action potential. Bobcat339, a selective and potent inhibitor of DNA demethylation, was used to determine whether AA promoted hiPSC-CM maturation through modulating DNA demethylation. Results: AA significantly increased MLC2v expression in PCBC-CMs, DP3-CMs, MLC2v-CMs, and RA induced atrial-like PCBC-CMs. AA treatment significantly increased mitochondrial mass, membrane potential, and amino acid and fatty acid metabolism in PCBC-CMs. Patch clamp studies showed that AA treatment induced PCBC-CMs and DP3-CMs adaptation to a ventricular-like phenotype. Bobcat339 inhibited MLC2v protein expression in AA treated PCBC-CMs and DP3-CMs. DNA demethylation inhibition was also associated with reduced TET1 and TET2 protein expressions and reduced accumulation of the oxidative product, 5 hmC, in both PCBC-CMs and DP3-CMs, in the presence of AA. Conclusions: Ascorbic acid induced MLC2v protein expression and promoted ventricular-like CM subtype in hiPSC-CMs. The effect of AA on hiPSC-CM was attenuated with inhibition of TET1/TET2 mediated DNA demethylation.PMID:37441603 | PMC:PMC10334833 | DOI:10.7150/thno.80801

Electroacupuncture treatment ameliorates metabolic disorders in obese ZDF rats by regulating liver energy metabolism and gut microbiota

Thu, 13/07/2023 - 12:00
Front Endocrinol (Lausanne). 2023 Jun 27;14:1207574. doi: 10.3389/fendo.2023.1207574. eCollection 2023.ABSTRACTMetabolic disorders represent a major therapeutic challenge to public health worldwide due to their dramatically increasing prevalence. Acupuncture is widely used as adjuvant therapy for multiple metabolic diseases. However, detailed biological interpretation of the acupuncture stimulations is still limited. The gut and the liver are intrinsically connected and related to metabolic function. Microbial metabolites might affect the gut-liver axis through multiple mechanisms. Liver metabolomics and 16S rRNA sequencing were used to explore the specific mechanism of electroacupuncture in treating ZDF rats in this study. Electroacupuncture effectively improved glycolipid metabolism disorders of the ZDF rats. Histopathology confirmed that electroacupuncture improved diffuse hepatic steatosis and hepatocyte vacuolation, and promoted glycogen accumulation in the liver. The treatment significantly improved microbial diversity and richness and upregulated beneficial bacteria that maintain intestinal epithelial homeostasis and decreased bacteria with detrimental metabolic features on host metabolism. Liver metabolomics showed that the main effects of electroacupuncture include reducing the carbon flow and intermediate products in the TCA cycle, regulating the metabolism of various amino acids, and inhibiting hepatic glucose output and de novo lipogenesis. The gut-liver axis correlation analysis showed a strong correlation between the liver metabolites and the gut microbiota, especially allantoin and Adlercreutzia. Electroacupuncture treatment can improve abnormal energy metabolism by reducing oxidative stress, ectopic fat deposition, and altering metabolic fluxes. Our results will help us to further understand the specific mechanism of electroacupuncture in the treatment of metabolic diseases.PMID:37441502 | PMC:PMC10335763 | DOI:10.3389/fendo.2023.1207574

Contribution of Circulating Host and Microbial Tryptophan Metabolites Toward Ah Receptor Activation

Thu, 13/07/2023 - 12:00
Int J Tryptophan Res. 2023 Jul 7;16:11786469231182510. doi: 10.1177/11786469231182510. eCollection 2023.ABSTRACTThe aryl hydrocarbon receptor (AHR) is a ligand activated transcription factor that plays an integral role in homeostatic maintenance by regulating cellular functions such as cellular differentiation, metabolism, barrier function, and immune response. An important but poorly understood class of AHR activators are compounds derived from host and bacterial metabolism of tryptophan. The commensal bacteria of the gut microbiome are major producers of tryptophan metabolites known to activate the AHR, while the host also produces AHR activators through tryptophan metabolism. We used targeted mass spectrometry-based metabolite profiling to determine the presence and metabolic source of these metabolites in the sera of conventional mice, germ-free mice, and humans. Surprisingly, sera concentrations of many tryptophan metabolites are comparable between germ-free and conventional mice. Therefore, many major AHR-activating tryptophan metabolites in mouse sera are produced by the host, despite their presence in feces and mouse cecal contents. Here we present an investigation of AHR activation using a complex mixture of tryptophan metabolites to examine the biological relevance of circulating tryptophan metabolites. AHR activation is rarely studied in the context of a mixture at relevant concentrations, as we present here. The AHR activation potentials of individual and pooled metabolites were explored using cell-based assays, while ligand binding competition assays and ligand docking simulations were used to assess the detected metabolites as AHR agonists. The physiological and biomedical relevance of the identified metabolites was investigated in the context of a cell-based model for rheumatoid arthritis. We present data that reframe AHR biology to include the presence of a mixture of ubiquitous tryptophan metabolites, improving our understanding of homeostatic AHR activity and models of AHR-linked diseases.PMID:37441265 | PMC:PMC10334013 | DOI:10.1177/11786469231182510

Targeted metabolomics analysis of nucleosides and the identification of biomarkers for colorectal adenomas and colorectal cancer

Thu, 13/07/2023 - 12:00
Front Mol Biosci. 2023 Jun 27;10:1163089. doi: 10.3389/fmolb.2023.1163089. eCollection 2023.ABSTRACTThe morbidity and mortality of colorectal cancer (CRC) have been increasing in recent years, and early detection of CRC can improve the survival rate of patients. RNA methylation plays crucial roles in many biological processes and has been implicated in the initiation of various diseases, including cancer. Serum contains a variety of biomolecules and is an important clinical sample for biomarker discovery. In this study, we developed a targeted metabolomics method for the quantitative analysis of nucleosides in human serum samples by using liquid chromatography with tandem mass spectrometry (LC-MS/MS). We successfully quantified the concentrations of nucleosides in serum samples from 51 healthy controls, 37 patients with colorectal adenomas, and 55 patients with CRC. The results showed that the concentrations of N 6-methyladenosine (m6A), N 1-methyladenosine (m1A), and 3-methyluridine (m3U) were increased in patients with CRC, whereas the concentrations of N 2-methylguanosine (m2G), 2'-O-methyluridine (Um), and 2'-O-methylguanosine (Gm) were decreased in patients with CRC, compared with the healthy controls and patients with colorectal adenomas. Moreover, the levels of 2'-O-methyluridine and 2'-O-methylguanosine were lower in patients with colorectal adenomas than those in healthy controls. Interestingly, the levels of Um and Gm gradually decreased in the following order: healthy controls to colorectal adenoma patients to CRC patients. These results revealed that the aberrations of these nucleosides were tightly correlated to colorectal adenomas and CRC. In addition, the present work will stimulate future investigations about the regulatory roles of these nucleosides in the initiation and development of CRC.PMID:37441164 | PMC:PMC10334214 | DOI:10.3389/fmolb.2023.1163089

Impact of the pentose phosphate pathway on metabolism and pathogenesis of Staphylococcus aureus

Thu, 13/07/2023 - 12:00
PLoS Pathog. 2023 Jul 13;19(7):e1011531. doi: 10.1371/journal.ppat.1011531. Online ahead of print.ABSTRACTStaphylococcus aureus is an important pathogen that leads to significant disease through multiple routes of infection. We recently published a transposon sequencing (Tn-seq) screen in a mouse acute pneumonia model and identified a hypothetical gene (SAUSA300_1902, pgl) with similarity to a lactonase of Escherichia coli involved in the pentose phosphate pathway (PPP) that was conditionally essential. Limited studies have investigated the role of the PPP in physiology and pathogenesis of S. aureus. We show here that mutation of pgl significantly impacts ATP levels and respiration. RNA-seq analysis of the pgl mutant and parent strains identified compensatory changes in gene expression for glucose and gluconate as well as reductions in the pyrimidine biosynthesis locus. These differences were also evident through unbiased metabolomics studies and 13C labeling experiments that showed mutation of pgl led to reductions in pyrimidine metabolism including decreases in ribose-5P, UMP and GMP. These nucleotide reductions impacted the amount of extracellular DNA in biofilms and reduced biofilm formation. Mutation also limited the capacity of the strain to resist oxidant damage induced by hydrogen peroxide and paraquat and subsequent intracellular survival inside macrophages. Changes in wall teichoic acid impacted susceptibility to hydrogen peroxide. We demonstrated the importance of these changes on virulence in three different models of infection, covering respiratory, skin and septicemia, demonstrating the need for proper PPP function in all models. This work demonstrates the multifaceted role metabolism can play in multiple aspects of S. aureus pathogenesis.PMID:37440594 | DOI:10.1371/journal.ppat.1011531

Gene expression and metabolic activity of Streptococcus mutans during exposure to dietary carbohydrates glucose, sucrose, lactose, and xylitol

Thu, 13/07/2023 - 12:00
Mol Oral Microbiol. 2023 Jul 13. doi: 10.1111/omi.12428. Online ahead of print.ABSTRACTRecent RNA sequencing studies have given us a deeper insight into the cariogenic impact of carbohydrate sources in the bacterium Streptococcus mutans, the principal microbial agent in dental caries etiopathogenesis. The process of dental caries development is facilitated by the ability of this bacterium to ferment some carbohydrates into organic acids contributing to a pH decrease in the oral cavity and the demineralization of the hard tissues of the tooth. Furthermore, in dental caries progression, biofilm formation, which starts and ends with free planktonic cells, plays an important role and has several unique properties called virulence factors. The most cariogenic carbohydrate is sucrose, an easily metabolizable source of energy that induces the acidification and synthesis of glucans, forming typical bacterial cell clumps. We used multifaceted methodological approaches to compare the transcriptomic and metabolomic profiles of S. mutans growing in planktonic culture on preferred and nonpreferred carbohydrates and in fasting conditions. Streptococcus mutans in a planktonic culture with lactose produced the same pH drop as glucose and sucrose. By contrast, xylitol and lactose showed high effectiveness in regulating intracellular polysaccharide metabolism, cell wall structure, and overall virulence involved in the initial phase of biofilm formation and structure but with an opposite pattern compared with sucrose and glucose. Our results confirmed the recent findings that xylitol and lactose play a vital role in biofilm structure. However, they do not reduce its formation, which is related to the creation of a cariogenic environment.PMID:37440366 | DOI:10.1111/omi.12428

Mechanism of Xiaoyao San in treating non-alcoholic fatty liver disease with liver depression and spleen deficiency: based on bioinformatics, metabolomics and <em>in vivo</em> experiments

Thu, 13/07/2023 - 12:00
J Biomol Struct Dyn. 2023 Jul 13:1-19. doi: 10.1080/07391102.2023.2231544. Online ahead of print.ABSTRACTXiaoyao san (XYS) plays an important role in treatment of non-alcoholic fatty liver disease (NAFLD) with liver stagnation and spleen deficiency, but its specific mechanism is still unclear. This study aimed to investigate the material basis and mechanism by means of network pharmacology, metabolomics, systems biology and molecular docking methods. On this basis, NAFLD rat model with liver stagnation and spleen deficiency was constructed and XYS was used to intervene, and liver histopathology, biochemical detection, enzyme-linked immunosorbent assay, quantitative PCR assay and western blotting were used to further verify the mechanism. Through the above research methods, network pharmacology study showed that there were 94 targets in total for XYS in the treatment of NAFLD. Metabolomics study showed that NAFLD with liver depression and spleen deficiency had a total of 73 differential metabolites. Systems biology found that PTGS2 and PPARG were the core targets; Quercetin, kaempferol, naringenin, beta-sitosterol and stigmasterol were the core active components; AA, cAMP were the core metabolites. And molecular docking showed that the core active components can act well on the key targets. Animal experiments showed that XYS could improve liver histopathology, increase 5HT and NA, decrease INS and FBG, improve blood lipids and liver function, decrease AA, increase cAMP, down-regulate PTGS2, up-regulate PPARG, and decrease PGE2 and 15d-PGJ2. In conclusion, XYS might treat NAFLD with liver depression and spleen deficiency by down-regulating PTGS2, up-regulating PPARG, reducing AA content, increasing cAMP, improving insulin resistance, affecting glucose and lipid metabolism, inhibiting oxidative stress and inflammatory response.Communicated by Ramaswamy H. Sarma.PMID:37440274 | DOI:10.1080/07391102.2023.2231544

Retinal Metabolic Profile on IMPG2 Deficiency Mice with Subretinal Lesions

Thu, 13/07/2023 - 12:00
Adv Exp Med Biol. 2023;1415:457-463. doi: 10.1007/978-3-031-27681-1_67.ABSTRACTThe interphotoreceptor matrix (IPM) is the extracellular matrix between the photoreceptors and the retinal pigment epithelium (RPE). The IPM has two proteoglycans: the IPM proteoglycans 1 and 2 (IMPG1 and IMPG2, respectively). Patients with mutations on IMPG2 develop subretinal vitelliform lesions that affect vision. We previously created an IMPG2 knockout (KO) mice model that generates subretinal lesions similar to those found in humans. These subretinal lesions in IMPG2 KO mice retinas are, in part, composed of mislocalized IMPG1. In addition, IMPG2 KO mice show microscopic IMPG1 material accumulation between the RPE and the photoreceptor outer segments. In this work we discuss the possibility that material accumulation on IMPG2 KO mice retinas affects photoreceptor metabolism. To further investigate this idea, we used targeted metabolomics to profile retinal metabolome on IMPG2 KO mice. The metabolite set enrichment analysis showed reduced glutamate metabolism, urea cycle, and galactose metabolism suggesting affected energy metabolism in mice retinas of IMPG2 KO mice with subretinal lesion.PMID:37440072 | DOI:10.1007/978-3-031-27681-1_67

Rod Photoreceptor-Specific Ablation of Metformin Target, AMPK, in a Preclinical Model of Autosomal Recessive Retinitis Pigmentosa

Thu, 13/07/2023 - 12:00
Adv Exp Med Biol. 2023;1415:403-408. doi: 10.1007/978-3-031-27681-1_59.ABSTRACTRetinal gene therapies have shown tremendous progress in the past decade, but the sheer number of disease-causing mutations makes their applicability challenging. In this study we test our hypothesis that retinitis pigmentosa-associated retinal degeneration can be prevented through AMP-activated protein kinase (AMPK)-associated metabolic pathway reprogramming using a gene-independent model of degeneration and rescue. We show that recue of photoreceptor structure and function is not achieved through our model of metabolic reprogramming. These results suggest that RP may not be treatable through AMPK pathway modulation-based therapies.PMID:37440064 | DOI:10.1007/978-3-031-27681-1_59

Multi-Omics Reveals the Impact of Exogenous Short-Chain Fatty Acid Infusion on Rumen Homeostasis: Insights into Crosstalk between the Microbiome and the Epithelium in a Goat Model

Thu, 13/07/2023 - 12:00
Microbiol Spectr. 2023 Jul 13:e0534322. doi: 10.1128/spectrum.05343-22. Online ahead of print.ABSTRACTEmerging data have underscored the significance of exogenous supplementation of butyrate in the regulation of rumen development and homeostasis. However, the effects of other short-chain fatty acids (SCFAs), such as acetate or propionate, has received comparatively less attention, and the consequences of extensive exogenous SCFA infusion remain largely unknown. In our study, we conducted a comprehensive investigation by infusion of three SCFAs to examine their respective roles in regulating the rumen microbiome, metabolism, and epithelium homeostasis. Data demonstrated that the infusion of sodium acetate (SA) increased rumen index while also promoting SCFA production and absorption through the upregulation of SCFA synthetic enzymes and the mRNA expression of SLC9A1 gene. Moreover, both SA and sodium propionate infusion resulted in an enhanced total antioxidant capacity, an increased concentration of occludin, and higher abundances of specific rumen bacteria, such as "Candidatus Saccharimonas," Christensenellaceae R-7, Butyrivibrio, Rikenellaceae RC9 gut, and Alloprevotella. In addition, sodium butyrate (SB) infusion exhibited positive effects by increasing the width of rumen papilla and the thickness of the stratum basale. SB infusion further enhanced antioxidant capacity and barrier function facilitated by cross talk with Monoglobus and Incertae Sedis. Furthermore, metabolome and transcriptome data revealed distinct metabolic patterns in rumen contents and epithelium, with a particular impact on amino acid and fatty acid metabolism processes. In conclusion, our data provided novel insights into the regulator effects of extensive infusion of the three major SCFAs on rumen fermentation patterns, antioxidant capacity, rumen barrier function, and rumen papilla development, all achieved without inducing rumen epithelial inflammation. IMPORTANCE The consequences of massive exogenous supplementation of SCFAs on rumen microbial fermentation and rumen epithelium health remain an area that requires further exploration. In our study, we sought to investigate the specific impact of administering high doses of exogenous acetate, propionate, and butyrate on rumen homeostasis, with a particular focus on understanding the interaction between the rumen microbiome and epithelium. Importantly, our findings indicated that the massive infusion of these SCFAs did not induce rumen inflammation. Instead, we observed enhancements in antioxidant capacity, strengthening of rumen barrier function, and promotion of rumen papilla development, which were facilitated through interactions with specific rumen bacteria. By addressing existing knowledge gaps and offering critical insights into the regulation of rumen health through SCFA supplementation, our study holds significant implications for enhancing the well-being and productivity of ruminant animals.PMID:37439665 | DOI:10.1128/spectrum.05343-22

P2X7-receptor pathway involvement in the anti-inflammatory activity of medicinal plants

Thu, 13/07/2023 - 12:00
Chem Biodivers. 2023 Jul 13:e202300427. doi: 10.1002/cbdv.202300427. Online ahead of print.ABSTRACTMedicinal plants used in European folk medicine attached to Lamiales, Gentianales or Asterales orders are used to treat inflammatory disorders. Many targets have been identified but to date, implication of purinergic receptor P2X7 activation has not yet been investigated. We managed to evaluate the protective effect on P2X7 activation by plant extracts used as anti-inflammatory in European folk medicine by the YO-PRO-1 uptake dye in vitro bioassay. Results revealed that among our selected plants, species from Scrophularia and Plantago genus were able to decrease significantly P2X7 activation (> 50% at 0.1 and 1 µg/mL). UPLC-MS, dereplication and metabolomic analysis of Scrophularia extracts, allowed us to identify the cinnamoyl-iridoid harpagoside as putative inhibitor of P2X7 activation. These results open a new research field regarding the anti-inflammatory mechanism of cinnamoyl-iridoids bearing plants, which may involve the P2X7 receptor.PMID:37439445 | DOI:10.1002/cbdv.202300427

Metabolic signatures of cardiorenal dysfunction in plasma from sickle cell patients as a function of therapeutic transfusion and hydroxyurea treatment

Thu, 13/07/2023 - 12:00
Haematologica. 2023 Jul 13. doi: 10.3324/haematol.2023.283288. Online ahead of print.ABSTRACTMetabolomics studies in sickle cell disease (SCD) have been so far limited to tens of samples, owing to technical and experimental limitations. To overcome these limitations, we performed plasma metabolomics analyses on 596 samples from patients with SCD enrolled in the WALK-PHaSST study. Clinical covariates informed the biological interpretation of metabolomics data, including genotypes (hemoglobin SS, hemoglobin SC), history of recent transfusion (HbA%), response to hydroxyurea treatment (HbF%). We investigated metabolic correlates to the degree of intravascular hemolysis, cardiorenal function, as determined by tricuspid regurgitation velocity (TRV), estimated glomerular filtration rate (eGFR), and overall hazard ratio (unadjusted or adjusted by age). Recent transfusion events or hydroxyurea treatment were associated with elevation in plasma free fatty acids and decreases in acyl-carnitines, urate, kynurenine, indoles, carboxylic acids, and glycine- or taurine-conjugated bile acids. High levels of these metabolites, along with low levels of plasma S1P and L-arginine were identified as top markers of hemolysis, cardiorenal function (TRV, eGFR), and overall hazard ratio. We thus uploaded all omics and clinical data on a novel online portal that we used to identify a potential mechanism of dysregulated red cell S1P synthesis and export as a contributor to the more severe clinical manifestations in patients with the SS genotype compared to SC. In conclusion, plasma metabolic signatures - including low S1P, arginine and elevated kynurenine, acyl-carnitines and bile acids - are associated with clinical manifestation and therapeutic efficacy in SCD patients, suggesting new avenues for metabolic interventions in this patient population.PMID:37439373 | DOI:10.3324/haematol.2023.283288

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