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1.
J Proteome Res ; 21(3): 599-611, 2022 03 04.
Article in English | MEDLINE | ID: mdl-34758617

ABSTRACT

Acylcholines are comprised of an acyl chain esterified to a choline moiety; acetylcholine is the best-characterized member of this class, functioning as a neurotransmitter in the central and peripheral nervous systems as well as an inhibitor of cytokine production by macrophages and other innate immune cells. Acylcholines are metabolized by a class of cholinesterases, including acetylcholinesterase (a specific regulator of acetylcholine levels) and butyrylcholinesterase (BChE, an enigmatic enzyme whose function has not been resolved by genetic knockout models). BChE provides reserve capacity to hydrolyze acetylcholine, but its importance is arguable given acetylcholinesterase is the most catalytically efficient enzyme characterized to date. While known to be substrates of BChE in vitro, endogenous production of long-chain acylcholines is a recent discovery enabled by untargeted metabolomics. Compared to acetylcholine, long-chain acylcholines show greater stability in circulation with homeostatic levels-dictated by synthesis and clearance-suggested to impact cholinergic receptor sensitivity of acetylcholine with varying levels of antagonism. Acylcholines then provide a link between BChE and non-neuronal acetylcholine signaling, filling a gap in understanding around how imbalances between acylcholines and BChE could modulate inflammatory disease, such as the "cytokine storm" identified in severe COVID-19. Areas for further research, development, and clinical testing are outlined.


Subject(s)
Butyrylcholinesterase , COVID-19 , Acetylcholinesterase/genetics , Acetylcholinesterase/metabolism , Butyrylcholinesterase/genetics , Butyrylcholinesterase/metabolism , Cholinergic Agents , Humans , SARS-CoV-2
2.
Front Microbiol ; 12: 713234, 2021.
Article in English | MEDLINE | ID: mdl-34475864

ABSTRACT

Non-alcoholic fatty liver disease (NAFLD) is the leading cause of chronic liver disease in western countries both in children and adults. Metabolic dysregulation associated with gut microbial dysbiosis may influence disease progression from hepatic steatosis to inflammation and subsequent fibrosis. Using a multi-omics approach, we profiled the oral and fecal microbiome and plasma metabolites from 241 predominantly Latino children with non-alcoholic steatohepatitis (NASH), non-alcoholic fatty liver (NAFL), and controls. Children with more severe liver pathology were dysbiotic and had increased gene content associated with lipopolysaccharide biosynthesis and lipid, amino acid and carbohydrate metabolism. These changes were driven by increases in Bacteroides and concomitant decreases of Akkermansia, Anaerococcus, Corynebacterium, and Finegoldia. Non-targeted mass spectrometry revealed perturbations in one-carbon metabolism, mitochondrial dysfunction, and increased oxidative stress in children with steatohepatitis and fibrosis. Random forests modeling of plasma metabolites was highly predictive of non-alcoholic steatohepatitis (NASH) (97% accuracy) and hepatic fibrosis, steatosis and lobular inflammation (93.8% accuracy), and can differentiate steatohepatitis from simple steatosis (90.0% accuracy). Multi-omics predictive models for disease and histology findings revealed perturbations in one-carbon metabolism, mitochondrial dysfunction, and increased oxidative stress in children with steatohepatitis and fibrosis. These results highlight the promise of non-invasive biomarkers for the growing epidemic of fatty liver disease.

4.
Sci Rep ; 11(1): 6506, 2021 03 22.
Article in English | MEDLINE | ID: mdl-33753762

ABSTRACT

Gonadotropin administration during infertility treatment stimulates the growth and development of multiple ovarian follicles, yielding heterogeneous oocytes with variable capacity for fertilization, cleavage, and blastocyst formation. To determine how the intrafollicular environment affects oocyte competency, 74 individual rhesus macaque follicles were aspirated and the corresponding oocytes classified as failed to cleave, cleaved but arrested prior to blastulation, or those that formed blastocysts following in vitro fertilization. Metabolomics analysis of the follicular fluid (FF) identified 60 unique metabolites that were significantly different between embryo classifications, of which a notable increase in the intrafollicular ratio of cortisol to cortisone was observed in the blastocyst group. Immunolocalization of the glucocorticoid receptor (GR, NR3C1) revealed translocation from the cytoplasm to nucleus with oocyte maturation in vitro and, correlation to intrafollicular expression of the 11-hydroxy steroid dehydrogenases that interconvert these glucocorticoids was detected upon an ovulatory stimulus in vivo. While NR3C1 knockdown in oocytes had no effect on their maturation or fertilization, expansion of the associated cumulus granulosa cells was inhibited. Our findings indicate an important role for NR3C1 in the regulation of follicular processes via paracrine signaling. Further studies are required to define the means through which the FF cortisol:cortisone ratio determines oocyte competency.


Subject(s)
Fertilization in Vitro/methods , Follicular Fluid/metabolism , Glucocorticoids/metabolism , In Vitro Oocyte Maturation Techniques/methods , Metabolome , Oocytes/cytology , Ovulation , Animals , Blastocyst/cytology , Female , Macaca mulatta , Male , Oocyte Retrieval/methods , Oocytes/metabolism , Receptors, Glucocorticoid/metabolism
5.
Aging (Albany NY) ; 12(12): 11914-11941, 2020 06 01.
Article in English | MEDLINE | ID: mdl-32482911

ABSTRACT

Age-related declines in physical performance predict cognitive impairment, disability, chronic disease exacerbation, and mortality. We conducted a metabolome-wide association study of physical performance among Bogalusa Heart Study participants. Bonferroni corrected multivariate-adjusted linear regression was employed to examine cross-sectional associations between single metabolites and baseline gait speed (N=1,227) and grip strength (N=1,164). In a sub-sample of participants with repeated assessments of gait speed (N=282) and grip strength (N=201), significant metabolites from the cross-sectional analyses were tested for association with change in physical performance over 2.9 years of follow-up. Thirty-five and seven metabolites associated with baseline gait speed and grip strength respectively, including six metabolites that associated with both phenotypes. Three metabolites associated with preservation or improvement in gait speed over follow-up, including: sphingomyelin (40:2) (P=2.6×10-4) and behenoyl sphingomyelin (d18:1/22:0) and ergothioneine (both P<0.05). Seven metabolites associated with declines in gait speed, including: 1-carboxyethylphenylalanine (P=8.8×10-5), and N-acetylaspartate, N-formylmethionine, S-adenosylhomocysteine, N-acetylneuraminate, N2,N2-dimethylguanosine, and gamma-glutamylphenylalanine (all P<0.05). Two metabolite modules reflecting sphingolipid and bile acid metabolism associated with physical performance (minimum P=7.6×10-4). These results add to the accumulating evidence suggesting an important role of the human metabolome in physical performance and specifically implicate lipid, nucleotide, and amino acid metabolism in early physical performance decline.


Subject(s)
Aging/blood , Metabolome/physiology , Physical Functional Performance , Adult , Aging/metabolism , Biomarkers/blood , Biomarkers/metabolism , Cross-Sectional Studies , Female , Follow-Up Studies , Humans , Longitudinal Studies , Male , Metabolomics , Middle Aged
6.
Nutr Metab Cardiovasc Dis ; 30(5): 777-787, 2020 05 07.
Article in English | MEDLINE | ID: mdl-32131987

ABSTRACT

BACKGROUND AND AIMS: Dyslipidemia has been identified as a major risk factor for cardiovascular disease. We aimed to identify metabolites and metabolite modules showing novel association with lipids among Bogalusa Heart Study (BHS) participants using untargeted metabolomics. METHODS AND RESULTS: Untargeted ultrahigh performance liquid chromatography-tandem mass spectroscopy was used to quantify serum metabolites of 1 243 BHS participants (816 whites and 427 African-Americans). The association of single metabolites with lipids was assessed using multiple linear regression models to adjust for covariables. Weighted correlation network analysis was utilized to identify modules of co-abundant metabolites and examine their covariable adjusted correlations with lipids. All analyses were conducted according to race and using Bonferroni-corrected α-thresholds to determine statistical significance. Thirteen metabolites with known biochemical identities showing novel association achieved Bonferroni-significance, p < 1.04 × 10-5, and showed consistent effect directions in both whites and African-Americans. Twelve were from lipid sub-pathways including fatty acid metabolism (arachidonoylcholine, dihomo-linolenoyl-choline, docosahexaenoylcholine, linoleoylcholine, oleoylcholine, palmitoylcholine, and stearoylcholine), monohydroxy fatty acids (2-hydroxybehenate, 2-hydroxypalmitate, and 2-hydroxystearate), and lysoplasmalogens [1-(1-enyl-oleoyl)-GPE (P-18:1) and 1-(1-enyl-stearoyl)-GPE (P-18:0)]. The gamma-glutamylglutamine, peptide from the gamma-glutamyl amino acid sub-pathway, were also identified. In addition, four metabolite modules achieved Bonferroni-significance, p < 1.39 × 10-3, in both whites and African-Americans. These four modules were largely comprised of metabolites from lipid sub-pathways, with one module comprised of metabolites which were not identified in the single metabolite analyses. CONCLUSION: The current study identified 13 metabolites and 4 metabolite modules showing novel association with lipids, providing new insights into the physiological mechanisms regulating lipid levels.


Subject(s)
Cardiovascular Diseases/blood , Chromatography, High Pressure Liquid , Dyslipidemias/blood , Lipids/blood , Metabolomics , Tandem Mass Spectrometry , Adult , Black or African American , Biomarkers/blood , Cardiovascular Diseases/diagnosis , Cardiovascular Diseases/ethnology , Cross-Sectional Studies , Dyslipidemias/diagnosis , Dyslipidemias/ethnology , Female , Humans , Louisiana/epidemiology , Male , Middle Aged , Phenotype , Predictive Value of Tests , Race Factors , Risk Factors , White People
7.
Metabolomics ; 15(12): 149, 2019 11 13.
Article in English | MEDLINE | ID: mdl-31720858

ABSTRACT

INTRODUCTION: Chronic kidney disease (CKD) is a major public health challenge given its high global prevalence and associated risks of cardiovascular disease and progression to end stage renal disease. Although it is known that numerous metabolic changes occur in CKD patients, identifying novel metabolite associations with kidney function may enhance our understanding of the physiologic pathways relating to CKD. OBJECTIVES: The objective of this study was to elucidate novel metabolite associations with kidney function among participants of two community-based cohorts with carefully ascertained metabolomics, kidney function, and covariate data. METHODS: Untargeted ultrahigh-performance liquid chromatography-tandem mass spectrometry was used to detect and quantify blood metabolites. We used multivariate adjusted linear regression to examine associations between single metabolites and creatinine-based estimated glomerular filtration rate (eGFRcr) among 1243 Bogalusa Heart Study (BHS) participants (median eGFRcr: 94.4, 5th-95th percentile: 66.0-119.6 mL/min/1.73 m2). Replication, determined by statistical significance and consistent effect direction, was tested using gold standard measured glomerular filtration rate (mGFR) among 260 Multi-Ethnic Study of Atherosclerosis (MESA) participants (median mGFR: 72.0, 5th-95th percentile: 43.5-105.0 mL/min/1.73 m2). All analyses used Bonferroni-corrected alpha thresholds. RESULTS: Fifty-one novel metabolite associations with kidney function were identified, including 12 from previously unrelated sub-pathways: N6-carboxymethyllysine, gulonate, quinolinate, gamma-CEHC-glucuronide, retinol, methylmalonate, 3-hydroxy-3-methylglutarate, 3-aminoisobutyrate, N-methylpipecolate, hydroquinone sulfate, and glycine conjugates of C10H12O2 and C10H14O2(1). Significant metabolites were generally inversely associated with kidney function and smaller in mass-to-charge ratio than non-significant metabolites. CONCLUSION: The 51 novel metabolites identified may serve as early, clinically relevant, kidney function biomarkers.


Subject(s)
Biomarkers/blood , Renal Insufficiency, Chronic/metabolism , Aged , Aged, 80 and over , Atherosclerosis/complications , Atherosclerosis/metabolism , Chromatography, Liquid/methods , Creatinine/blood , Female , Glomerular Filtration Rate/physiology , Humans , Kidney Function Tests/methods , Longitudinal Studies , Male , Metabolomics/methods , Middle Aged , Renal Insufficiency, Chronic/physiopathology
8.
Nat Commun ; 10(1): 4052, 2019 09 06.
Article in English | MEDLINE | ID: mdl-31492856

ABSTRACT

Metabolites are active controllers of cellular physiology, but their role in complex behaviors is less clear. Here we report metabolic changes that occur during the transition between hunger and satiety in Drosophila melanogaster. To analyze these data in the context of fruit fly metabolic networks, we developed Flyscape, an open-access tool. We show that in response to eating, metabolic profiles change in quick, but distinct ways in the heads and bodies. Consumption of a high sugar diet dulls the metabolic and behavioral differences between the fasted and fed state, and reshapes the way nutrients are utilized upon eating. Specifically, we found that high dietary sugar increases TCA cycle activity, alters neurochemicals, and depletes 1-carbon metabolism and brain health metabolites N-acetyl-aspartate and kynurenine. Together, our work identifies the metabolic transitions that occur during hunger and satiation, and provides a platform to study the role of metabolites and diet in complex behavior.


Subject(s)
Drosophila melanogaster/physiology , Hunger/physiology , Metabolic Networks and Pathways/physiology , Metabolome/physiology , Satiation/physiology , Animals , Brain/metabolism , Brain/physiology , Diet , Drosophila melanogaster/metabolism , Eating/physiology , Fasting/physiology , Humans , Metabolomics/methods
9.
PLoS Genet ; 15(9): e1008208, 2019 09.
Article in English | MEDLINE | ID: mdl-31553721

ABSTRACT

Variation in steroid hormone levels has wide implications for health and disease. The genes encoding the proteins involved in steroid disposition represent key determinants of interindividual variation in steroid levels and ultimately, their effects. Beginning with metabolomic data from genome-wide association studies (GWAS), we observed that genetic variants in the orphan transporter, SLC22A24 were significantly associated with levels of androsterone glucuronide and etiocholanolone glucuronide (sentinel SNPs p-value <1x10-30). In cells over-expressing human or various mammalian orthologs of SLC22A24, we showed that steroid conjugates and bile acids were substrates of the transporter. Phylogenetic, genomic, and transcriptomic analyses suggested that SLC22A24 has a specialized role in the kidney and appears to function in the reabsorption of organic anions, and in particular, anionic steroids. Phenome-wide analysis showed that functional variants of SLC22A24 are associated with human disease such as cardiovascular diseases and acne, which have been linked to dysregulated steroid metabolism. Collectively, these functional genomic studies reveal a previously uncharacterized protein involved in steroid homeostasis, opening up new possibilities for SLC22A24 as a pharmacological target for regulating steroid levels.


Subject(s)
Organic Cation Transport Proteins/metabolism , Steroids/metabolism , Symporters/metabolism , Androsterone/analogs & derivatives , Androsterone/genetics , Androsterone/metabolism , Animals , Biological Transport , Genome-Wide Association Study/methods , HEK293 Cells , Humans , Metabolomics/methods , Models, Molecular , Organic Cation Transport Proteins/chemistry , Organic Cation Transport Proteins/genetics , Phylogeny , Polymorphism, Single Nucleotide , Symporters/chemistry , Symporters/genetics
10.
Aging (Albany NY) ; 11(14): 5124-5139, 2019 07 21.
Article in English | MEDLINE | ID: mdl-31327759

ABSTRACT

BACKGROUND: Metabolomics study provides an opportunity to identify novel molecular determinants of altered cognitive function. METHODS: During 2013 to 2016 Bogalusa Heart Study (BHS) visit, 1,177 participants underwent untargeted, ultrahigh performance liquid chromatography-tandem mass spectroscopy metabolomics profiling. Global cognition and five cognition domains were also assessed. The cross-sectional associations of single metabolites with cognition were tested using multiple linear regression models. Weighted correlation network analysis was used to examine the covariable-adjusted correlations of modules of co-abundant metabolites with cognition. Analyses were conducted in the overall sample and according to both ethnicity and sex. RESULTS: Five known metabolites and two metabolite modules robustly associated with cognition across overall and stratified analyses. Two metabolites were from lipid sub-pathways including fatty acid metabolism [9-hydroxystearate; minimum P-value (min-P)=1.11×10-5], and primary bile acid metabolism (glyco-alpha-muricholate; min-P=4.10×10-5). One metabolite from the glycogen metabolism sub-pathway (maltose; min-P=9.77×10-6), one from the polyamine metabolism sub-pathway (N-acetyl-isoputreanine; min-P=1.03×10-5), and one from the purine metabolism sub-pathway (7-methylguanine; min-P=1.19×10-5) were also identified. Two metabolite modules reflecting bile acid metabolism and androgenic steroids correlated with cognition (min-P=5.00×10-4 and 3.00×10-3, respectively). CONCLUSION: The novel associations of 5 known metabolites and 2 metabolite modules with cognition provide insights into the physiological mechanisms regulating cognitive function.


Subject(s)
Cognition/physiology , Metabolome , Cross-Sectional Studies , Female , Humans , Longitudinal Studies , Male , Metabolomics , Middle Aged , Phenotype
11.
Cell ; 177(6): 1448-1462.e14, 2019 05 30.
Article in English | MEDLINE | ID: mdl-31150621

ABSTRACT

Mammals rely on a network of circadian clocks to control daily systemic metabolism and physiology. The central pacemaker in the suprachiasmatic nucleus (SCN) is considered hierarchically dominant over peripheral clocks, whose degree of independence, or tissue-level autonomy, has never been ascertained in vivo. Using arrhythmic Bmal1-null mice, we generated animals with reconstituted circadian expression of BMAL1 exclusively in the liver (Liver-RE). High-throughput transcriptomics and metabolomics show that the liver has independent circadian functions specific for metabolic processes such as the NAD+ salvage pathway and glycogen turnover. However, although BMAL1 occupies chromatin at most genomic targets in Liver-RE mice, circadian expression is restricted to ∼10% of normally rhythmic transcripts. Finally, rhythmic clock gene expression is lost in Liver-RE mice under constant darkness. Hence, full circadian function in the liver depends on signals emanating from other clocks, and light contributes to tissue-autonomous clock function.


Subject(s)
ARNTL Transcription Factors/physiology , Circadian Clocks/genetics , Liver/metabolism , ARNTL Transcription Factors/metabolism , Animals , CLOCK Proteins/metabolism , Circadian Clocks/physiology , Circadian Rhythm/genetics , Female , Gene Expression Regulation , Homeostasis , Light , Male , Mice , Mice, Knockout , Models, Animal , Organ Specificity/physiology , Photoperiod , Suprachiasmatic Nucleus/metabolism
12.
Methods Mol Biol ; 1922: 525-548, 2019.
Article in English | MEDLINE | ID: mdl-30838598

ABSTRACT

Early childhood caries (ECC) is a biofilm-mediated disease. Social, environmental, and behavioral determinants as well as innate susceptibility are major influences on its incidence; however, from a pathogenetic standpoint, the disease is defined and driven by oral dysbiosis. In other words, the disease occurs when the natural equilibrium between the host and its oral microbiome shifts toward states that promote demineralization at the biofilm-tooth surface interface. Thus, a comprehensive understanding of dental caries as a disease requires the characterization of both the composition and the function or metabolic activity of the supragingival biofilm according to well-defined clinical statuses. However, taxonomic and functional information of the supragingival biofilm is rarely available in clinical cohorts, and its collection presents unique challenges among very young children. This paper presents a protocol and pipelines available for the conduct of supragingival biofilm microbiome studies among children in the primary dentition, that has been designed in the context of a large-scale population-based genetic epidemiologic study of ECC. The protocol is being developed for the collection of two supragingival biofilm samples from the maxillary primary dentition, enabling downstream taxonomic (e.g., metagenomics) and functional (e.g., transcriptomics and metabolomics) analyses. The protocol is being implemented in the assembly of a pediatric precision medicine cohort comprising over 6000 participants to date, contributing social, environmental, behavioral, clinical, and biological data informing ECC and other oral health outcomes.


Subject(s)
Bacteria/genetics , Biofilms , Dental Caries/microbiology , Metabolomics/methods , Metagenomics/methods , Tooth, Deciduous/microbiology , Bacteria/isolation & purification , Bacteria/metabolism , Child, Preschool , DNA, Bacterial/genetics , Dental Caries/etiology , Gene Expression Profiling/methods , Gingiva/microbiology , Humans , Microbiota , RNA, Bacterial/genetics , Sequence Analysis, DNA/methods , Sequence Analysis, RNA/methods , Software , Specimen Handling/methods , Transcriptome
13.
Cell Metab ; 29(2): 443-456.e5, 2019 02 05.
Article in English | MEDLINE | ID: mdl-30595481

ABSTRACT

During wound injury, efferocytosis fills the macrophage with a metabolite load nearly equal to the phagocyte itself. A timely question pertains to how metabolic phagocytic signaling regulates the signature anti-inflammatory macrophage response. Here we report the metabolome of activated macrophages during efferocytosis to reveal an interleukin-10 (IL-10) cytokine escalation that was independent of glycolysis yet bolstered by apoptotic cell fatty acids and mitochondrial ß-oxidation, the electron transport chain, and heightened coenzyme NAD+. Loss of IL-10 due to mitochondrial complex III defects was remarkably rescued by adding NAD+ precursors. This activated a SIRTUIN1 signaling cascade, largely independent of ATP, that culminated in activation of IL-10 transcription factor PBX1. Il-10 activation by the respiratory chain was also important in vivo, as efferocyte mitochondrial dysfunction led to cardiac rupture after myocardial injury. These findings highlight a new paradigm whereby macrophages leverage efferocytic metabolites and electron transport for anti-inflammatory reprogramming that culminates in organ repair.


Subject(s)
Fatty Acids/metabolism , Interleukin-10/metabolism , Macrophages/metabolism , Mitochondria/metabolism , NAD/metabolism , Animals , Cytophagocytosis , Electron Transport , Humans , Inflammation/metabolism , Jurkat Cells , Macrophages/cytology , Mice , Mice, Inbred C57BL , Oxidation-Reduction , Wound Healing
14.
Mol Autism ; 9: 35, 2018.
Article in English | MEDLINE | ID: mdl-29854372

ABSTRACT

Background: Children with autism spectrum disorder (ASD) have urinary metabolites suggesting impairments in several pathways, including oxidative stress, inflammation, mitochondrial dysfunction, and gut microbiome alterations. Sulforaphane, a supplement with indirect antioxidant effects that are derived from broccoli sprouts and seeds, was recently shown to lead to improvements in behavior and social responsiveness in children with ASD. We conducted the current open-label study to determine if we could identify changes in urinary metabolites that were associated with clinical improvements with the goal of identifying a potential mechanism of action. Methods: Children and young adults enrolled in a school for children with ASD and related neurodevelopmental disorders were recruited to participate in a 12-week, open-label study of sulforaphane. Fasting urinary metabolites and measures of behavior (Aberrant Behavior Checklist-ABC) and social responsiveness (Social Responsiveness Scale-SRS) were measured at baseline and at the end of the study. Pearson's correlation coefficient was calculated for the pre- to post-intervention change in each of the two clinical scales (ABS and SRS) versus the change in each metabolite. Results: Fifteen children completed the 12-week study. Mean scores on both symptom measures showed improvements (decreases) over the study period, but only the change in the SRS was significant. The ABC improved - 7.1 points (95% CI - 17.4 to 3.2), and the SRS improved - 9.7 points (95% CI - 18.7 to - 0.8). We identified 77 urinary metabolites that were correlated with changes in symptoms, and they clustered into pathways of oxidative stress, amino acid/gut microbiome, neurotransmitters, hormones, and sphingomyelin metabolism. Conclusions: Urinary metabolomics analysis is a useful tool to identify pathways that may be involved in the mechanism of action of treatments targeting abnormal physiology in ASD. Trial registration: This study was prospectively registered at clinicaltrials.gov (NCT02654743) on January 11, 2016.


Subject(s)
Antioxidants/therapeutic use , Autistic Disorder/drug therapy , Isothiocyanates/therapeutic use , Metabolome , Adolescent , Antioxidants/administration & dosage , Antioxidants/analysis , Autistic Disorder/urine , Biomarkers/urine , Brassica/chemistry , Child , Female , Humans , Isothiocyanates/administration & dosage , Isothiocyanates/analysis , Male , Social Behavior , Sulfoxides , Young Adult
15.
Hum Mol Genet ; 27(12): 2113-2124, 2018 06 15.
Article in English | MEDLINE | ID: mdl-29635516

ABSTRACT

Tuberous sclerosis complex (TSC) is an autosomal dominant neurodevelopmental disorder and the quintessential disorder of mechanistic Target of Rapamycin Complex 1 (mTORC1) dysregulation. Loss of either causative gene, TSC1 or TSC2, leads to constitutive mTORC1 kinase activation and a pathologically anabolic state of macromolecular biosynthesis. Little is known about the organ-specific metabolic reprogramming that occurs in TSC-affected organs. Using a mouse model of TSC in which Tsc2 is disrupted in radial glial precursors and their neuronal and glial descendants, we performed an unbiased metabolomic analysis of hippocampi to identify Tsc2-dependent metabolic changes. Significant metabolic reprogramming was found in well-established pathways associated with mTORC1 activation, including redox homeostasis, glutamine/tricarboxylic acid cycle, pentose and nucleotide metabolism. Changes in two novel pathways were identified: transmethylation and polyamine metabolism. Changes in transmethylation included reduced methionine, cystathionine, S-adenosylmethionine (SAM-the major methyl donor), reduced SAM/S-adenosylhomocysteine ratio (cellular methylation potential), and elevated betaine, an alternative methyl donor. These changes were associated with alterations in SAM-dependent methylation pathways and expression of the enzymes methionine adenosyltransferase 2A and cystathionine beta synthase. We also found increased levels of the polyamine putrescine due to increased activity of ornithine decarboxylase, the rate-determining enzyme in polyamine synthesis. Treatment of Tsc2+/- mice with the ornithine decarboxylase inhibitor α-difluoromethylornithine, to reduce putrescine synthesis dose-dependently reduced hippocampal astrogliosis. These data establish roles for SAM-dependent methylation reactions and polyamine metabolism in TSC neuropathology. Importantly, both pathways are amenable to nutritional or pharmacologic therapy.


Subject(s)
Brain/metabolism , Metabolomics , Tuberous Sclerosis/metabolism , Animals , Brain/pathology , Cystathionine/genetics , Cystathionine beta-Synthase/genetics , DNA Methylation/genetics , Disease Models, Animal , Eflornithine/administration & dosage , Humans , Mechanistic Target of Rapamycin Complex 1/genetics , Methionine Adenosyltransferase/genetics , Mice , Neurons/metabolism , Neurons/pathology , Polyamines/metabolism , Putrescine/biosynthesis , S-Adenosylmethionine/metabolism , Tuberous Sclerosis/genetics , Tuberous Sclerosis/pathology , Tuberous Sclerosis Complex 1 Protein/genetics , Tuberous Sclerosis Complex 2 Protein/genetics
16.
Sci Rep ; 8(1): 1006, 2018 01 17.
Article in English | MEDLINE | ID: mdl-29343811

ABSTRACT

Biological aging profoundly impairs muscle function, performance, and metabolism. Because the progression of metabolic alterations associated with aging muscle has not been chronicled, we tracked the metabolic profiles of flight muscle from middle to advanced age in Manduca sexta to identify key molecules during the progression of muscle aging, as well as to evaluate the utility of the M. sexta system for molecular dissection of muscle aging. We identified a number of differences between Diel Time, Sexes, and Muscle Ages, including changes in metabolites related to energetics, extracellular matrix turnover, and glutathione metabolism. Increased abundances of glycolytic metabolites suggest a shift toward increased glycolysis with advancing age, whereas decreased abundances in lysolipids and acylcarnitines reflect decreasing beta-oxidation. We also observed a shift towards decreased polyamine metabolism with age, which might result in an age-related decline in lipid metabolism possibly due to regulation of energy metabolism by polyamines. Collectively, our findings demonstrate the feasibility of our system and approach and provide a deeper understanding of lepidopteran aging. More importantly, the results identify the key altered metabolic pathways that collectively contribute to the muscle aging phenotype and thereby improve our understanding of muscle senescence.


Subject(s)
Aging/metabolism , Manduca/metabolism , Metabolome , Muscle Development/physiology , Muscles/metabolism , Animals , Female , Flight, Animal/physiology , Glutathione/metabolism , Glycolysis/physiology , Lipid Metabolism/physiology , Male , Manduca/growth & development , Oxidative Phosphorylation , Polyamines/metabolism
17.
Arthritis Rheumatol ; 69(10): 1984-1995, 2017 10.
Article in English | MEDLINE | ID: mdl-28622455

ABSTRACT

OBJECTIVE: HLA-B27-associated spondyloarthritides are associated with an altered intestinal microbiota and bowel inflammation. We undertook this study to identify HLA-B27-dependent changes in both host and microbial metabolites in the HLA-B27/ß2 -microglobulin (ß2 m)-transgenic rat and to determine whether microbiota-derived metabolites could impact disease in this major model of spondyloarthritis. METHODS: Cecal contents were collected from Fischer 344 33-3 HLA-B27/ß2 m-transgenic rats and wild-type controls at 6 weeks (before disease) and 16 weeks (with active bowel inflammation). Metabolomic profiling was performed by high-throughput gas and liquid chromatography-based mass spectrometry. HLA-B27/ß2 m-transgenic rats were treated with the microbial metabolites propionate or butyrate in drinking water for 10 weeks, and disease activity was subsequently assessed. RESULTS: Our screen identified 582 metabolites, of which more than half were significantly altered by HLA-B27 expression at 16 weeks. Both microbial and host metabolites were altered, with multiple pathways affected, including those for amino acid, carbohydrate, xenobiotic, and medium-chain fatty acid metabolism. Differences were even observed at 6 weeks, with up-regulation of histidine, tyrosine, spermidine, N-acetylmuramate, and glycerate in HLA-B27/ß2 m-transgenic rats. Administration of the short-chain fatty acid propionate significantly attenuated HLA-B27-associated inflammatory disease, although this was not associated with increased FoxP3+ T cell induction or with altered expression of the immunomodulatory cytokines interleukin-10 (IL-10) or IL-33 or of the tight junction protein zonula occludens 1. HLA-B27 expression was also associated with altered host expression of messenger RNA for the microbial metabolite receptors free fatty acid receptor 2 (FFAR2), FFAR3, and niacin receptor 1. CONCLUSION: HLA-B27 expression profoundly impacts the intestinal metabolome, with changes evident in rats even at age 6 weeks. Critically, we demonstrate that a microbial metabolite, propionate, attenuates development of HLA-B27-associated inflammatory disease. These and other microbiota-derived bioactive mediators may provide novel treatment modalities in HLA-B27-associated spondyloarthritides.


Subject(s)
Cecum/metabolism , Gastrointestinal Microbiome , HLA-B27 Antigen/genetics , Spondylarthropathies/metabolism , Animals , Butyric Acid/pharmacology , Cecum/microbiology , Chromatography, High Pressure Liquid , Disease Models, Animal , Fatty Acids, Volatile/metabolism , Flow Cytometry , Gas Chromatography-Mass Spectrometry , Gene Expression Profiling , Glyceric Acids/metabolism , Histidine/metabolism , Interleukin-10/immunology , Interleukin-33/immunology , Lymph Nodes/cytology , Mass Spectrometry , Mesentery , Metabolomics , Muramic Acids/metabolism , Propionates/pharmacology , Rats , Rats, Inbred F344 , Rats, Transgenic , Spermidine/metabolism , Spleen/cytology , Spondylarthropathies/genetics , Spondylarthropathies/immunology , T-Lymphocytes/immunology , Tyrosine/metabolism , Up-Regulation , beta 2-Microglobulin/genetics
18.
Nature ; 539(7630): 570-574, 2016 11 24.
Article in English | MEDLINE | ID: mdl-27820945

ABSTRACT

Professional phagocytes (such as macrophages) and non-professional phagocytes (such as epithelial cells) clear billions of apoptotic cells and particles on a daily basis. Although professional and non-professional macrophages reside in proximity in most tissues, whether they communicate with each other during cell clearance, and how this might affect inflammation, is not known. Here we show that macrophages, through the release of a soluble growth factor and microvesicles, alter the type of particles engulfed by non-professional phagocytes and influence their inflammatory response. During phagocytosis of apoptotic cells or in response to inflammation-associated cytokines, macrophages released insulin-like growth factor 1 (IGF-1). The binding of IGF-1 to its receptor on non-professional phagocytes redirected their phagocytosis, such that uptake of larger apoptotic cells was reduced whereas engulfment of microvesicles was increased. IGF-1 did not alter engulfment by macrophages. Macrophages also released microvesicles, whose uptake by epithelial cells was enhanced by IGF-1 and led to decreased inflammatory responses by epithelial cells. Consistent with these observations, deletion of IGF-1 receptor in airway epithelial cells led to exacerbated lung inflammation after allergen exposure. These genetic and functional studies reveal that IGF-1- and microvesicle-dependent communication between macrophages and epithelial cells can critically influence the magnitude of tissue inflammation in vivo.


Subject(s)
Epithelial Cells/cytology , Macrophages/cytology , Phagocytes/cytology , Phagocytosis , Pneumonia , Allergens/immunology , Animals , Apoptosis , Cell Communication , Cytokines/metabolism , Epithelial Cells/immunology , Epithelial Cells/metabolism , Female , Fibroblasts/cytology , Humans , Macrophages/immunology , Macrophages/metabolism , Male , Mice , Phagocytes/immunology , Phagocytes/metabolism , Pneumonia/immunology , Pneumonia/metabolism , Receptor, IGF Type 1/deficiency , Receptor, IGF Type 1/metabolism , Respiratory System/cytology , Somatomedins/metabolism
19.
J Nutr ; 146(9): 1641-50, 2016 09.
Article in English | MEDLINE | ID: mdl-27489005

ABSTRACT

BACKGROUND: Although a reductionist approach has sought to understand the roles of individual nutrients and biochemicals in foods, it has become apparent that there can be differences when studying food components in isolation or within the natural matrix of a whole food. OBJECTIVE: The objective of this study was to determine the ability of whole-food intake to modulate the development of obesity and other metabolic dysfunction in mice fed a high-fat (HF), Western-style obesogenic diet. To test the hypothesis that an n-3 (ω-3) polyunsaturated fatty acid-rich food could synergize with other, largely polyphenol-rich foods by producing greater reductions in metabolic disease conditions, the intake of English walnuts was evaluated in combination with 9 other whole foods. METHODS: Eight-week-old male C57Bl/6J mice were fed low-fat (LF; 10% fat) and HF control diets, along with an HF diet with 8.6% (wt:wt) added walnuts for 9 wk. The HF control diet contained 46% fat with added sucrose (10.9%, wt:wt) and cholesterol (1%, wt:wt); the added sucrose and cholesterol were not present in the LF diet. Other groups were provided the walnut diet with a second whole food-raspberries, apples, cranberries, tart cherries, broccoli sprouts, olive oil, soy protein, or green tea. All of the energy-containing whole foods were added at an energy level equivalent to 1.5 servings/d. Body weights, food intake, and glucose tolerance were determined. Postmortem, serum lipids and inflammatory markers, hepatic fat, gene expression, and the relative concentrations of 594 biochemicals were measured. RESULTS: The addition of walnuts with either raspberries, apples, or green tea reduced glucose area under the curve compared with the HF diet alone (-93%, -64%, and -54%, respectively, P < 0.05). Compared with HF-fed mice, mice fed walnuts with either broccoli sprouts or green tea (-49% and -61%, respectively, P < 0.05) had reduced hepatic fat concentrations. There were differences in global gene expression patterns related to whole-food content, with many examples of differences in LF- and HF-fed mice, HF- and walnut-fed mice, and mice fed walnuts and walnuts plus other foods. The mean ± SEM increase in relative hepatic concentrations of the n-3 fatty acids α-linolenic acid, eicosapentanoic acid, and docosapentanoic acid in all walnut-fed groups was 124% ± 13%, 159% ± 11%, and 114% ± 10%, respectively (P < 0.0001), compared with LF- and HF-fed mice not consuming walnuts. CONCLUSIONS: In obese male mice, walnut consumption with an HF Western-style diet caused changes in hepatic fat concentrations, gene expression patterns, and fatty acid concentrations. The addition of a second whole food in combination with walnuts produced other changes in metabolite concentrations and gene expression patterns and other physiologic markers. Importantly, these substantial changes occurred in mice fed typical amounts of intake, representing only 1.5 servings each food/d.


Subject(s)
Diet, High-Fat , Diet, Western , Juglans , Nuts , Obesity/metabolism , Animals , Biomarkers/blood , Body Weight , Chemokine CCL2/blood , Cholesterol/blood , Eicosapentaenoic Acid , Energy Intake , Fatty Acids, Omega-3 , Gene Expression , Interleukin-6/blood , Liver/metabolism , Male , Metabolomics , Mice , Mice, Inbred C57BL , Mice, Obese , Obesity/genetics , Triglycerides/blood , Tumor Necrosis Factor-alpha/blood , alpha-Linolenic Acid
20.
Biol Pharm Bull ; 39(7): 1179-86, 2016.
Article in English | MEDLINE | ID: mdl-27374292

ABSTRACT

Serum metabolites can reflect the diffusion/export of biochemicals from various organs. They can serve as biomarkers related to diseases and therapeutic efficacy/toxicity. While studies in Caucasians suggested that subject gender and age can affect circulating metabolite profiles, the Japanese population has not been surveyed. Our objective was to delineate gender- and age-associated differences in serum metabolite profiles among Japanese populations. Using a mass spectrometry-based global metabolomics approach, 516 endogenous metabolites were detected in sera from Japanese individuals. The principal component analysis identified gender as the primary component, followed by age, suggesting that these two criteria were key contributors to variations in the dataset. Gender-associated differences were observed in 31 and 25% of metabolites in the young (age 25-35) and old (ages 55-65) populations, respectively, in redox homeostasis, and in steroid and purine nucleotide metabolism pathways. Age-associated differences were observed in 24 and 23% of metabolites in men and women, respectively. No pathway was commonly highlighted. Thus, gender and age impact on metabolite profiles in the Japanese population. Our results provide useful information to explore biomarkers for clinical applications in the Japanese population and to assess the applicability of known biomarkers identified in other populations to the Japanese population.


Subject(s)
Aging/metabolism , Metabolome , Serum/metabolism , Adult , Aged , Aging/blood , Asian People , Biomarkers/blood , Female , Humans , Male , Middle Aged , Principal Component Analysis , Sex Characteristics
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