RESUMEN
Metabolic homeostasis in mammals is tightly regulated by the complementary actions of insulin and glucagon. The secretion of these hormones from pancreatic ß-cells and α-cells, respectively, is controlled by metabolic, endocrine, and paracrine regulatory mechanisms and is essential for the control of blood levels of glucose. The deregulation of these mechanisms leads to various pathologies, most notably type 2 diabetes, which is driven by the combined lesions of impaired insulin action and a loss of the normal insulin secretion response to glucose. Glucose stimulates insulin secretion from ß-cells in a bi-modal fashion, and new insights about the underlying mechanisms, particularly relating to the second or amplifying phase of this secretory response, have been recently gained. Other recent work highlights the importance of α-cell-produced proglucagon-derived peptides, incretin hormones from the gastrointestinal tract and other dietary components, including certain amino acids and fatty acids, in priming and potentiation of the ß-cell glucose response. These advances provide a new perspective for the understanding of the ß-cell failure that triggers type 2 diabetes.
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Diabetes Mellitus Tipo 2/fisiopatología , Glucosa/metabolismo , Homeostasis , Secreción de Insulina , Células Secretoras de Insulina/fisiología , Animales , Humanos , Células Secretoras de Insulina/citologíaRESUMEN
Identifying interventions that more effectively promote healthy growth of children with undernutrition is a pressing global health goal. Analysis of human milk oligosaccharides (HMOs) from 6-month-postpartum mothers in two Malawian birth cohorts revealed that sialylated HMOs are significantly less abundant in those with severely stunted infants. To explore this association, we colonized young germ-free mice with a consortium of bacterial strains cultured from the fecal microbiota of a 6-month-old stunted Malawian infant and fed recipient animals a prototypic Malawian diet with or without purified sialylated bovine milk oligosaccharides (S-BMO). S-BMO produced a microbiota-dependent augmentation of lean body mass gain, changed bone morphology, and altered liver, muscle, and brain metabolism in ways indicative of a greater ability to utilize nutrients for anabolism. These effects were also documented in gnotobiotic piglets using the same consortium and Malawian diet. These preclinical models indicate a causal, microbiota-dependent relationship between S-BMO and growth promotion.
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Desarrollo Infantil , Desnutrición/dietoterapia , Leche Humana/química , Leche/química , Oligosacáridos/metabolismo , Animales , Bacteroides fragilis/genética , Bifidobacterium/clasificación , Bifidobacterium/genética , Química Encefálica , Modelos Animales de Enfermedad , Escherichia coli/genética , Heces/microbiología , Vida Libre de Gérmenes , Humanos , Lactante , Malaui , Masculino , Metabolómica , Ratones , Ratones Endogámicos C57BL , MicrobiotaRESUMEN
AIMS/HYPOTHESIS: Physiological gestational diabetes mellitus (GDM) subtypes that may confer different risks for adverse pregnancy outcomes have been defined. The aim of this study was to characterise the metabolome and genetic architecture of GDM subtypes to address the hypothesis that they differ between GDM subtypes. METHODS: This was a cross-sectional study of participants in the Hyperglycemia and Adverse Pregnancy Outcome (HAPO) study who underwent an OGTT at approximately 28 weeks' gestation. GDM was defined retrospectively using International Association of Diabetes and Pregnancy Study Groups/WHO criteria, and classified as insulin-deficient GDM (insulin secretion <25th percentile with preserved insulin sensitivity) or insulin-resistant GDM (insulin sensitivity <25th percentile with preserved insulin secretion). Metabolomic analyses were performed on fasting and 1 h serum samples in 3463 individuals (576 with GDM). Genome-wide genotype data were obtained for 8067 individuals (1323 with GDM). RESULTS: Regression analyses demonstrated striking differences between the metabolomes for insulin-deficient or insulin-resistant GDM compared to those with normal glucose tolerance. After adjustment for covariates, 33 fasting metabolites, including 22 medium- and long-chain acylcarnitines, were uniquely associated with insulin-deficient GDM; 23 metabolites, including the branched-chain amino acids and their metabolites, were uniquely associated with insulin-resistant GDM; two metabolites (glycerol and 2-hydroxybutyrate) were associated with the same direction of association with both subtypes. Subtype differences were also observed 1 h after a glucose load. In genome-wide association studies, variants within MTNR1B (rs10830963, p=3.43×10-18, OR 1.55) and GCKR (rs1260326, p=5.17×10-13, OR 1.43) were associated with GDM. Variants in GCKR (rs1260326, p=1.36×10-13, OR 1.60) and MTNR1B (rs10830963, p=1.22×10-9, OR 1.49) demonstrated genome-wide significant association with insulin-resistant GDM; there were no significant associations with insulin-deficient GDM. The lead SNP in GCKR, rs1260326, was associated with the levels of eight of the 25 fasting metabolites that were associated with insulin-resistant GDM and ten of 41 1 h metabolites that were associated with insulin-resistant GDM. CONCLUSIONS/INTERPRETATION: This study demonstrates that physiological GDM subtypes differ in their metabolome and genetic architecture. These findings require replication in additional cohorts, but suggest that these differences may contribute to subtype-related adverse pregnancy outcomes.
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Diabetes Gestacional , Hiperglucemia , Resistencia a la Insulina , Femenino , Embarazo , Humanos , Glucemia/metabolismo , Resistencia a la Insulina/genética , Resultado del Embarazo , Prueba de Tolerancia a la Glucosa , Estudio de Asociación del Genoma Completo , Estudios Transversales , Estudios Retrospectivos , Insulina/metabolismo , Glucosa/metabolismoRESUMEN
BACKGROUND: The circulating metabolome, reflecting underlying cellular processes and disease biology, has not been fully characterized in patients with idiopathic pulmonary fibrosis (IPF). We evaluated whether circulating levels of metabolites correlate with the presence of IPF, with the severity of IPF, or with the risk of clinically relevant outcomes among patients with IPF. METHODS: We analyzed enrollment plasma samples from 300 patients with IPF in the IPF-PRO Registry and 100 individuals without known lung disease using a set of targeted metabolomics and clinical analyte modules. Linear regression was used to compare metabolite and clinical analyte levels between patients with IPF and controls and to determine associations between metabolite levels and measures of disease severity in patients with IPF. Unadjusted and adjusted univariable Cox regression models were used to evaluate associations between circulating metabolites and the risk of mortality or disease progression among patients with IPF. RESULTS: Levels of 64 metabolites and 5 clinical analytes were significantly different between patients with IPF and controls. Among analytes with greatest differences were non-esterified fatty acids, multiple long-chain acylcarnitines, and select ceramides, levels of which were higher among patients with IPF versus controls. Levels of the branched-chain amino acids valine and leucine/isoleucine were inversely correlated with measures of disease severity. After adjusting for clinical factors known to influence outcomes, higher levels of the acylcarnitine C:16-OH/C:14-DC were associated with all-cause mortality, lower levels of the acylcarnitine C16:1-OH/C14:1DC were associated with all-cause mortality, respiratory death, and respiratory death or lung transplant, and higher levels of the sphingomyelin d43:2 were associated with the risk of respiratory death or lung transplantation. CONCLUSIONS: IPF has a distinct circulating metabolic profile characterized by increased levels of non-esterified fatty acids, long-chain acylcarnitines, and ceramides, which may suggest a more catabolic environment that enhances lipid mobilization and metabolism. We identified select metabolites that were highly correlated with measures of disease severity or the risk of disease progression and that may be developed further as biomarkers. TRIAL REGISTRATION: ClinicalTrials.gov; No: NCT01915511; URL: www. CLINICALTRIALS: gov .
Asunto(s)
Carnitina , Fibrosis Pulmonar Idiopática , Humanos , Carnitina/análogos & derivados , Ceramidas , Progresión de la Enfermedad , Ácidos Grasos , Fibrosis Pulmonar Idiopática/metabolismo , Metaboloma , Sistema de RegistrosRESUMEN
The concept that gut microbiome-expressed functions regulate ponderal growth has important implications for infant and child health, as well as animal health. Using an intergenerational pig model of diet restriction (DR) that produces reduced weight gain, we developed a feature-selection algorithm to identify representative characteristics distinguishing DR fecal microbiomes from those of full-fed (FF) pigs as both groups consumed a common sequence of diets during their growth cycle. Gnotobiotic mice were then colonized with DR and FF microbiomes and subjected to controlled feeding with a pig diet. DR microbiomes have reduced representation of genes that degrade dominant components of late growth-phase diets, exhibit reduced production of butyrate, a key host-accessible energy source, and are causally linked to reduced hepatic fatty acid metabolism (ß-oxidation) and the selection of alternative energy substrates. The approach described could aid in the development of guidelines for microbiome stewardship in diverse species, including farm animals, in order to support their healthy growth.
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Butiratos/metabolismo , Microbioma Gastrointestinal/fisiología , Metabolismo de los Lípidos/fisiología , Desnutrición/metabolismo , Monoéster Fosfórico Hidrolasas/metabolismo , alfa-Glucosidasas/metabolismo , Algoritmos , Animales , Peso Corporal , Dieta/métodos , Dietoterapia/métodos , Modelos Animales de Enfermedad , Heces/microbiología , Vida Libre de Gérmenes , Hígado/metabolismo , Masculino , Desnutrición/fisiopatología , Ratones , Ratones Endogámicos C57BL , Almidón/metabolismo , Sacarosa/metabolismo , Porcinos , Ácido Taurocólico/metabolismoRESUMEN
Hepatic steatosis associated with high-fat diet, obesity, and type 2 diabetes is thought to be the major driver of severe liver inflammation, fibrosis, and cirrhosis. Cytosolic acetyl CoA (AcCoA), a central metabolite and substrate for de novo lipogenesis (DNL), is produced from citrate by ATP-citrate lyase (ACLY) and from acetate through AcCoA synthase short chain family member 2 (ACSS2). However, the relative contributions of these two enzymes to hepatic AcCoA pools and DNL rates in response to high-fat feeding are unknown. We report here that hepatocyte-selective depletion of either ACSS2 or ACLY caused similar 50% decreases in liver AcCoA levels in obese mice, showing that both pathways contribute to the generation of this DNL substrate. Unexpectedly however, the hepatocyte ACLY depletion in obese mice paradoxically increased total DNL flux measured by D2O incorporation into palmitate, whereas in contrast, ACSS2 depletion had no effect. The increase in liver DNL upon ACLY depletion was associated with increased expression of nuclear sterol regulatory element-binding protein 1c and of its target DNL enzymes. This upregulated DNL enzyme expression explains the increased rate of palmitate synthesis in ACLY-depleted livers. Furthermore, this increased flux through DNL may also contribute to the observed depletion of AcCoA levels because of its increased conversion to malonyl CoA and palmitate. Together, these data indicate that in fat diet-fed obese mice, hepatic DNL is not limited by its immediate substrates AcCoA or malonyl CoA but rather by activities of DNL enzymes.
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Diabetes Mellitus Tipo 2 , Lipogénesis , Hígado , Proteína 1 de Unión a los Elementos Reguladores de Esteroles , Animales , Ratones , Acetilcoenzima A/metabolismo , Adenosina Trifosfato/metabolismo , ATP Citrato (pro-S)-Liasa/genética , ATP Citrato (pro-S)-Liasa/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Hepatocitos/metabolismo , Hígado/metabolismo , Malonil Coenzima A/metabolismo , Ratones Obesos , Palmitatos/metabolismo , Proteína 1 de Unión a los Elementos Reguladores de Esteroles/genética , Proteína 1 de Unión a los Elementos Reguladores de Esteroles/metabolismoRESUMEN
BACKGROUND: Sodium-glucose cotransporter-2 inhibitors are foundational therapy in patients with heart failure with reduced ejection fraction (HFrEF), but underlying mechanisms of benefit are not well defined. We sought to investigate the relationships between sodium-glucose cotransporter-2 inhibitor treatment, changes in metabolic pathways, and outcomes using targeted metabolomics. METHODS: DEFINE-HF (Dapagliflozin Effects on Biomarkers, Symptoms and Functional Status in Patients With HF With Reduced Ejection Fraction) was a placebo-controlled trial of dapagliflozin in HFrEF. We performed targeted mass spectrometry profiling of 63 metabolites (45 acylcarnitines [markers of fatty acid oxidation], 15 amino acids, and 3 conventional metabolites) in plasma samples at randomization and 12 weeks. Using mixed models, we identified principal components analysis-defined metabolite clusters that changed differentially with treatment and examined the relationship between change in metabolite clusters and change in Kansas City Cardiomyopathy Questionnaire scores and NT-proBNP (N-terminal probrain natriuretic peptide). Models were adjusted for relevant clinical covariates and nominal P<0.05 with false discovery rate-adjusted P<0.10 was used to determine statistical significance. RESULTS: Among the 234 DEFINE-HF participants with targeted metabolomic data, the mean age was 62.0±11.1 years, 25% were women, 38% were Black, and mean ejection fraction was 27±8%. Dapagliflozin increased ketone-related and short-chain acylcarnitine as well as medium-chain acylcarnitine principal components analysis-defined metabolite clusters compared with placebo (nominal P=0.01, false discovery rate-adjusted P=0.08 for both clusters). However, ketosis (ß-hydroxybutyrate levels >500 µmol/L) was achieved infrequently (3 [2.5%] in dapagliflozin arm versus 1 [0.9%] in placebo arm) and supraphysiologic levels were not observed. Increases in long-chain acylcarnitine, long-chain dicarboxylacylcarnitine, and aromatic amino acid metabolite clusters were associated with decreases in Kansas City Cardiomyopathy Questionnaire scores (ie, worse quality of life) and increases in NT-proBNP levels, without interaction by treatment group. CONCLUSIONS: In this study of targeted metabolomics in a placebo-controlled trial of sodium-glucose cotransporter-2 inhibitors in HFrEF, we observed effects of dapagliflozin on key metabolic pathways, supporting a role for altered ketone and fatty acid biology with sodium-glucose cotransporter-2 inhibitors in patients with HFrEF. Only physiologic levels of ketosis were observed. In addition, we identified several metabolic biomarkers associated with adverse HFrEF outcomes. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT02653482.
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Cardiomiopatías , Insuficiencia Cardíaca , Cetosis , Inhibidores del Cotransportador de Sodio-Glucosa 2 , Disfunción Ventricular Izquierda , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Compuestos de Bencidrilo/efectos adversos , Biomarcadores , Cardiomiopatías/complicaciones , Ácidos Grasos , Glucósidos , Cetonas/uso terapéutico , Calidad de Vida , Inhibidores del Cotransportador de Sodio-Glucosa 2/farmacología , Inhibidores del Cotransportador de Sodio-Glucosa 2/uso terapéutico , Volumen Sistólico/fisiología , Disfunción Ventricular Izquierda/complicacionesRESUMEN
BACKGROUND: Whether differences in circulating long chain acylcarnitines (LCAC) are seen in heart failure (HF) patients with and without diabetes mellitus (DM), and whether these biomarkers report on exercise capacity and clinical outcomes, remains unknown. The objective of the current study was to use metabolomic profiling to identify biomarkers that report on exercise capacity, clinical outcomes, and differential response to exercise in HF patients with and without DM. METHODS: Targeted mass spectrometry was used to quantify metabolites in plasma from participants in the heart failure: a controlled trial investigating outcomes of exercise training (HF-ACTION) trial. Principal components analysis was used to identify 12 uncorrelated factors. The association between metabolite factors, diabetes status, exercise capacity, and time to the primary clinical outcome of all-cause mortality or all-cause hospitalization was assessed. RESULTS: A total of 664 participants were included: 359 (54%) with DM. LCAC factor levels were associated with baseline exercise capacity as measured by peak oxygen consumption (beta 0.86, p = 2 × 10-7, and were differentially associated in participants with and without DM (beta 1.58, p = 8 × 10-8 vs. 0.67, p = 9 × 10-4, respectively; p value for interaction = 0.012). LCAC levels changed to a lesser extent in participants with DM after exercise (mean ∆ 0.09, p = 0.24) than in those without DM (mean ∆ 0.16, p = 0.08). In univariate and multivariate modeling, LCAC factor levels were associated with time to the primary outcome (multivariate HR 0.80, p = 2.74 × 10-8), and were more strongly linked to outcomes in diabetic participants (HR 0.64, p = 3.21 × 10-9 v. HR 0.90, p = 0.104, p value for interaction = 0.001). When analysis was performed at the level of individual metabolites, C16, C16:1, C18, and C18:1 had the greatest associations with both exercise capacity and outcomes, with higher levels associated with worse outcomes. Similar associations with time to the primary clinical outcome were not found in a control group of patients without HF from the CATHeterization GENetics (CATHGEN) study. CONCLUSIONS: LCAC biomarkers are associated with exercise status and clinical outcomes differentially in HF patients with and without DM. Impaired fatty acid substrate utilization and mitochondrial dysfunction both at the level of the skeletal muscle and the myocardium may explain the decreased exercise capacity, attenuated response to exercise training, and poor clinical outcomes seen in patients with HF and DM. Trial Registration clinicaltrials.gov Identifier: NCT00047437.
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Carnitina/análogos & derivados , Cardiomiopatías Diabéticas/sangre , Tolerancia al Ejercicio , Insuficiencia Cardíaca/sangre , Anciano , Biomarcadores/sangre , Carnitina/sangre , Ensayos Clínicos como Asunto , Cardiomiopatías Diabéticas/diagnóstico , Cardiomiopatías Diabéticas/mortalidad , Cardiomiopatías Diabéticas/fisiopatología , Femenino , Estado de Salud , Insuficiencia Cardíaca/diagnóstico , Insuficiencia Cardíaca/mortalidad , Insuficiencia Cardíaca/fisiopatología , Hospitalización , Humanos , Masculino , Metaboloma , Metabolómica , Persona de Mediana Edad , Pronóstico , Medición de Riesgo , Factores de Riesgo , Espectrometría de Masas en Tándem , Factores de TiempoRESUMEN
Genetic manipulation via transgene overexpression, RNAi, or Cas9-based methods is central to biomedical research. Unfortunately, use of these tools is often limited by vector options. We have created a modular platform (pMVP) that allows a gene of interest to be studied in the context of an array of promoters, epitope tags, conditional expression modalities, and fluorescent reporters, packaged in 35 custom destination vectors, including adenovirus, lentivirus, PiggyBac transposon, and Sleeping Beauty transposon, in aggregate >108,000 vector permutations. We also used pMVP to build an epigenetic engineering platform, pMAGIC, that packages multiple gRNAs and either Sa-dCas9 or x-dCas9(3.7) fused to one of five epigenetic modifiers. Importantly, via its compatibility with adenoviral vectors, pMAGIC uniquely enables use of dCas9/LSD1 fusions to interrogate enhancers within primary cells. To demonstrate this, we used pMAGIC to target Sa-dCas9/LSD1 and modify the epigenetic status of a conserved enhancer, resulting in altered expression of the homeobox transcription factor PDX1 and its target genes in pancreatic islets and insulinoma cells. In sum, the pMVP and pMAGIC systems empower researchers to rapidly generate purpose-built, customized vectors for manipulation of gene expression, including via targeted epigenetic modification of regulatory elements in a broad range of disease-relevant cell types.
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Sistemas CRISPR-Cas/genética , Ingeniería Genética/métodos , Vectores Genéticos/genética , Proteínas de Homeodominio/genética , Transactivadores/genética , Transgenes/genética , Adenoviridae/genética , Animales , Elementos Transponibles de ADN/genética , Elementos de Facilitación Genéticos/genética , Epigenómica/métodos , Edición Génica/métodos , Regulación de la Expresión Génica/genética , Células HEK293 , Histona Demetilasas/genética , Humanos , Insulinoma/metabolismo , Islotes Pancreáticos/metabolismo , Lentivirus/genética , Ratones , Regiones Promotoras Genéticas/genética , ARN Guía de Kinetoplastida/genética , RatasRESUMEN
AIMS/HYPOTHESIS: Our study aimed to integrate maternal metabolic and genetic data related to insulin sensitivity during pregnancy to provide novel insights into mechanisms underlying pregnancy-induced insulin resistance. METHODS: Fasting and 1 h serum samples were collected from women in the Hyperglycemia and Adverse Pregnancy Outcome study who underwent an OGTT at â¼28 weeks' gestation. We obtained targeted and non-targeted metabolomics and genome-wide association data from 1600 and 4528 mothers, respectively, in four ancestry groups (Northern European, Afro-Caribbean, Mexican American and Thai); 1412 of the women had both metabolomics and genome-wide association data. Insulin sensitivity was calculated using a modified insulin sensitivity index that included fasting and 1 h glucose and C-peptide levels after a 75 g glucose load. RESULTS: Per-metabolite and network analyses across the four ancestries identified numerous metabolites associated with maternal insulin sensitivity before and 1 h after a glucose load, ranging from amino acids and carbohydrates to fatty acids and lipids. Genome-wide association analyses identified 12 genetic variants in the glucokinase regulatory protein gene locus that were significantly associated with maternal insulin sensitivity, including a common functional missense mutation, rs1260326 (ß = -0.2004, p = 4.67 × 10-12 in a meta-analysis across the four ancestries). This SNP was also significantly associated with multiple fasting and 1 h metabolites during pregnancy, including fasting and 1 h triacylglycerols and 2-hydroxybutyrate and 1 h lactate, 2-ketoleucine/ketoisoleucine and palmitoleic acid. Mediation analysis suggested that 1 h palmitoleic acid contributes, in part, to the association of rs1260326 with maternal insulin sensitivity, explaining 13.7% (95% CI 4.0%, 23.3%) of the total effect. CONCLUSIONS/INTERPRETATION: The present study demonstrates commonalities between metabolites and genetic variants associated with insulin sensitivity in the gravid and non-gravid states and provides insights into mechanisms underlying pregnancy-induced insulin resistance. Graphical abstract.
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Resistencia a la Insulina/genética , Metabolómica , Embarazo/genética , Proteínas Adaptadoras Transductoras de Señales/genética , Adulto , Pueblo Asiatico , Población Negra , Diabetes Gestacional/genética , Diabetes Gestacional/metabolismo , Femenino , Estudio de Asociación del Genoma Completo , Prueba de Tolerancia a la Glucosa , Humanos , Resistencia a la Insulina/fisiología , Análisis de Mediación , Americanos Mexicanos , Mutación Missense , Polimorfismo de Nucleótido Simple , Embarazo/metabolismo , Población Blanca , Adulto JovenRESUMEN
Elevations in circulating levels of branched-chain amino acids (BCAAs) are associated with a variety of cardiometabolic diseases and conditions. Restriction of dietary BCAAs in rodent models of obesity lowers circulating BCAA levels and improves whole-animal and skeletal-muscle insulin sensitivity and lipid homeostasis, but the impact of BCAA supply on heart metabolism has not been studied. Here, we report that feeding a BCAA-restricted chow diet to Zucker fatty rats (ZFRs) causes a shift in cardiac fuel metabolism that favors fatty acid relative to glucose catabolism. This is illustrated by an increase in labeling of acetyl-CoA from [1-13C]palmitate and a decrease in labeling of acetyl-CoA and malonyl-CoA from [U-13C]glucose, accompanied by a decrease in cardiac hexokinase II and glucose transporter 4 protein levels. Metabolomic profiling of heart tissue supports these findings by demonstrating an increase in levels of a host of fatty-acid-derived metabolites in hearts from ZFRs and Zucker lean rats (ZLRs) fed the BCAA-restricted diet. In addition, the twofold increase in cardiac triglyceride stores in ZFRs compared with ZLRs fed on chow diet is eliminated in ZFRs fed on the BCAA-restricted diet. Finally, the enzymatic activity of branched-chain ketoacid dehydrogenase (BCKDH) is not influenced by BCAA restriction, and levels of BCAA in the heart instead reflect their levels in circulation. In summary, reducing BCAA supply in obesity improves cardiac metabolic health by a mechanism independent of alterations in BCKDH activity.
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Aminoácidos de Cadena Ramificada/deficiencia , Dieta , Miocardio/metabolismo , Obesidad/metabolismo , Triglicéridos/metabolismo , Acetilcoenzima A/metabolismo , Aminoácidos de Cadena Ramificada/sangre , Animales , Glucosa/metabolismo , Masculino , Malonil Coenzima A/metabolismo , Metabolómica , Palmitatos/metabolismo , Proteínas Quinasas/metabolismo , Ratas , Ratas ZuckerRESUMEN
Sirtuins are a family of proteins that regulate biological processes such as cellular stress and aging by removing posttranslational modifications (PTMs). We recently identified several novel PTMs that can be removed by sirtuin 4 (SIRT4), which is found in mitochondria. We showed that mice with a global loss of SIRT4 [SIRT4-knockout (KO) mice] developed an increase in glucose- and leucine-stimulated insulin secretion, and this was followed by accelerated age-induced glucose intolerance and insulin resistance. Because whole body SIRT4-KO mice had alterations to nutrient-stimulated insulin secretion, we hypothesized that SIRT4 plays a direct role in regulating pancreatic ß-cell function. Thus, we tested whether ß-cell-specific ablation of SIRT4 would recapitulate the elevated insulin secretion seen in mice with a global loss of SIRT4. Tamoxifen-inducible ß-cell-specific SIRT4-KO mice were generated, and their glucose tolerance and glucose- and leucine-stimulated insulin secretion were measured over time. These mice exhibited normal glucose- and leucine-stimulated insulin secretion and maintained normal glucose tolerance even as they aged. Furthermore, 832/13 ß-cells with a CRISPR/Cas9n-mediated loss of SIRT4 did not show any alterations in nutrient-stimulated insulin secretion. Despite the fact that whole body SIRT4-KO mice demonstrated an age-induced increase in glucose- and leucine-stimulated insulin secretion, our current data indicate that the loss of SIRT4 specifically in pancreatic ß-cells, both in vivo and in vitro, does not have a significant impact on nutrient-stimulated insulin secretion. These data suggest that SIRT4 controls nutrient-stimulated insulin secretion during aging by acting on tissues external to the ß-cell, which warrants further study.
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Secreción de Insulina/fisiología , Células Secretoras de Insulina/metabolismo , Proteínas Mitocondriales/metabolismo , Sirtuinas/metabolismo , Animales , Glucosa/farmacología , Intolerancia a la Glucosa/metabolismo , Resistencia a la Insulina , Islotes Pancreáticos/citología , Islotes Pancreáticos/metabolismo , Leucina/farmacología , Ratones , Ratones Noqueados , Mitocondrias/metabolismo , Nutrientes , Procesamiento Proteico-PostraduccionalRESUMEN
Disturbances in cardiac metabolism underlie most cardiovascular diseases. Metabolomics, one of the newer omics technologies, has emerged as a powerful tool for defining changes in both global and cardiac-specific metabolism that occur across a spectrum of cardiovascular disease states. Findings from metabolomics studies have contributed to better understanding of the metabolic changes that occur in heart failure and ischemic heart disease and have identified new cardiovascular disease biomarkers. As technologies advance, the metabolomics field continues to evolve rapidly. In this review, we will discuss the current state of metabolomics technologies, including consideration of various metabolomics platforms and elements of study design; the emerging utility of stable isotopes for metabolic flux studies; and the use of metabolomics to better understand specific cardiovascular diseases, with an emphasis on recent advances in the field.
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Enfermedades Cardiovasculares/metabolismo , Metabolómica , Animales , Cromatografía Liquida , Predicción , Humanos , Isótopos/análisis , Espectrometría de Masas , Metabolómica/métodos , Ratones , Miocardio/metabolismo , Resonancia Magnética Nuclear Biomolecular , Proteoma , Proyectos de Investigación , Medición de Riesgo , Manejo de EspecímenesRESUMEN
Nearly unlimited supplies of energy-dense foods and technologies that encourage sedentary behaviour have introduced a new threat to the survival of our species: obesity and its co-morbidities. Foremost among the co-morbidities is type 2 diabetes, which is projected to afflict 300 million people worldwide by 2020. Compliance with lifestyle modifications such as reduced caloric intake and increased physical activity has proved to be difficult for the general population, meaning that pharmacological intervention may be the only recourse for some. This epidemiological reality heightens the urgency for gaining a deeper understanding of the processes that cause metabolic failure of key tissues and organ systems in type 2 diabetes, as reviewed here.
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Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Tipo 2/patología , Resistencia a la Insulina/fisiología , Células Secretoras de Insulina/patología , Animales , Diabetes Mellitus Tipo 2/genética , Glucosa/metabolismo , Humanos , Insulina/metabolismo , Transducción de SeñalRESUMEN
AIMS/HYPOTHESIS: We aimed to determine the association of maternal metabolites with newborn adiposity and hyperinsulinaemia in a multi-ethnic cohort of mother-newborn dyads. METHODS: Targeted and non-targeted metabolomics assays were performed on fasting and 1 h serum samples from a total of 1600 mothers in four ancestry groups (Northern European, Afro-Caribbean, Mexican American and Thai) who participated in the Hyperglycemia and Adverse Pregnancy Outcome (HAPO) study, underwent an OGTT at ~28 weeks gestation and whose newborns had anthropometric measurements at birth. RESULTS: In this observational study, meta-analyses demonstrated significant associations of maternal fasting and 1 h metabolites with birthweight, cord C-peptide and/or sum of skinfolds across ancestry groups. In particular, maternal fasting triacylglycerols were associated with newborn sum of skinfolds. At 1 h, several amino acids, fatty acids and lipid metabolites were associated with one or more newborn outcomes. Network analyses revealed clusters of fasting acylcarnitines, amino acids, lipids and fatty acid metabolites associated with cord C-peptide and sum of skinfolds, with the addition of branched-chain and aromatic amino acids at 1 h. CONCLUSIONS/INTERPRETATION: The maternal metabolome during pregnancy is associated with newborn outcomes. Maternal levels of amino acids, acylcarnitines, lipids and fatty acids and their metabolites during pregnancy relate to fetal growth, adiposity and cord C-peptide, independent of maternal BMI and blood glucose levels.
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Peso al Nacer/fisiología , Hiperinsulinismo/metabolismo , Metaboloma , Adulto , Péptido C/sangre , Femenino , Prueba de Tolerancia a la Glucosa , Humanos , Recién Nacido , Masculino , Metabolómica , Embarazo , Resultado del Embarazo , Triglicéridos/sangreRESUMEN
BACKGROUND: Peripheral blood metabolite profiles have yielded mechanistic insights into various cardiovascular disease states. We hypothesized that peripheral blood metabolite profiles would be associated with new onset atrial fibrillation (AF). METHODS AND RESULTS: The study population comprised 1892 patients without AF at baseline, who, as part the MURDOCK Cardiovascular Disease Study molecular profiling cohort (n = 2023), had previously had determination of levels of 69 metabolites from frozen, fasting plasma specimens obtained during coronary angiography. We used Cox proportional hazards models to examine the association of 13 uncorrelated metabolite factors created from these data using principal components analysis (PCA) with new occurrences of AF during a median follow up of 2.8 (0.1-4.9) years. A total of 233 patients developed new AF (12.3%) during follow up. Patients with new onset AF were older (median 67 vs. 60 years); more often white (82 vs. 71%) and male (68 vs. 60%), and had more comorbidities than those who did not develop AF. After adjustment, PCA factor 1 (medium chain acylcarnitines; hazard ratio [HR]: 1.11 [1.01-1.22]), factor 2 (short chain dicarboxylacylcarnitines; HR: 1.21 [1.09-1.34]) and factor 5 (long chain acylcarnitines; HR: 1.19 [1.06-1.34]) were associated with new onset AF. CONCLUSION: Metabolite profiles were associated with new onset AF among patients referred for coronary angiography. Validation of these observations in broader patient populations may provide better mechanistic insight into the development of AF, and may provide new opportunities for prevention and treatment.
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Fibrilación Atrial/sangre , Biomarcadores/sangre , Anciano , Aminoácidos/sangre , Fibrilación Atrial/diagnóstico por imagen , Carbohidratos/sangre , Carnitina/análogos & derivados , Carnitina/sangre , Angiografía Coronaria , Ácidos Grasos/sangre , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Mitocondrias Cardíacas/metabolismo , Análisis de Componente Principal , Modelos de Riesgos Proporcionales , Factores de RiesgoRESUMEN
Acetylation is increasingly recognized as an important metabolic regulatory posttranslational protein modification, yet the metabolic consequence of mitochondrial protein hyperacetylation is unknown. We find that high-fat diet (HFD) feeding induces hepatic mitochondrial protein hyperacetylation in mice and downregulation of the major mitochondrial protein deacetylase SIRT3. Mice lacking SIRT3 (SIRT3KO) placed on a HFD show accelerated obesity, insulin resistance, hyperlipidemia, and steatohepatitis compared to wild-type (WT) mice. The lipogenic enzyme stearoyl-CoA desaturase 1 is highly induced in SIRT3KO mice, and its deletion rescues both WT and SIRT3KO mice from HFD-induced hepatic steatosis and insulin resistance. We further identify a single nucleotide polymorphism in the human SIRT3 gene that is suggestive of a genetic association with the metabolic syndrome. This polymorphism encodes a point mutation in the SIRT3 protein, which reduces its overall enzymatic efficiency. Our findings show that loss of SIRT3 and dysregulation of mitochondrial protein acetylation contribute to the metabolic syndrome.
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Síndrome Metabólico/genética , Síndrome Metabólico/metabolismo , Proteínas Mitocondriales/metabolismo , Sirtuina 3/genética , Acetilación , Animales , Dieta Alta en Grasa , Humanos , Ratones , Ratones Noqueados , Modelos Biológicos , Sirtuina 3/metabolismoRESUMEN
Background: Recent studies, primarily in non-Hispanic whites, suggest that dietary patterns have distinct metabolomic signatures that may influence disease risk. However, evidence in South Asians, a group with unique dietary patterns and a high prevalence of cardiometabolic risk, is lacking. Objective: We investigated the metabolomic profiles associated with 2 distinct dietary patterns among a sample of Asian Indians living in the United States. We also examined the cross-sectional associations between metabolomic profiles and cardiometabolic risk markers. Methods: We used cross-sectional data from 145 Asian Indians, aged 45-79 y, in the Metabolic Syndrome and Atherosclerosis in South Asians Living in America (MASALA) pilot study. Metabolomic profiles were measured from fasting serum samples. Usual diet was assessed by using a validated food-frequency questionnaire. We used principal components analysis to derive dietary and metabolomic patterns. We used adjusted general linear regression models to examine associations between dietary patterns, individual food groups, metabolite patterns, and cardiometabolic risk markers. Results: We observed 2 major principal components or metabolite clusters, the first comprised primarily of medium- to long-chain acylcarnitines (metabolite pattern 1) and the second characterized by branched-chain amino acids, aromatic amino acids, and short-chain acylcarnitines (metabolite pattern 2). A "Western/nonvegetarian" pattern was significantly and positively associated with metabolite pattern 2 (all participants: ß ± SE = 0.180 ± 0.090, P = 0.05; participants without type 2 diabetes: ß ± SE = 0.323 ± 0.090, P = 0.0005). In all participants, higher scores on metabolite pattern 2 were adversely associated with measures of glycemia (fasting insulin: ß ± SE = 2.91 ± 1.29, P = 0.03; 2-h insulin: ß ± SE = 22.1 ± 10.3, P = 0.03; homeostasis model assessment of insulin resistance: ß ± SE = 0.94 ± 0.42, P = 0.03), total adiponectin (ß ± SE = -1.46 ± 0.47, P = 0.002), lipids (total cholesterol: ß ± SE = 7.51 ± 3.45, P = 0.03; triglycerides: ß ± SE = 14.4 ± 6.67, P = 0.03), and a radiographic measure of hepatic fat (liver-to-spleen attenuation ratio: ß ± SE = -0.83 ± 0.42, P = 0.05). Conclusions: Our findings suggest that a "Western/nonvegetarian" dietary pattern is associated with a metabolomic profile that is related to an adverse cardiometabolic profile in Asian Indians. Public health efforts to reduce cardiometabolic disease burden in this high-risk group should focus on consuming a healthy plant-based diet.
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Enfermedades Cardiovasculares/etiología , Conducta Alimentaria , Enfermedades Metabólicas/etiología , Metabolómica , Anciano , Biomarcadores , Estudios Transversales , Encuestas sobre Dietas , Femenino , Humanos , India , Masculino , Persona de Mediana EdadRESUMEN
The HIV-1 envelope protein (Env) has evolved to subvert the host immune system, hindering viral control by the host. The tryptophan metabolic enzyme kynureninase (KYNU) is mimicked by a portion of the HIV Env gp41 membrane proximal region (MPER) and is cross-reactive with the HIV broadly neutralizing Ab (bnAb) 2F5. Molecular mimicry of host proteins by pathogens can lead to autoimmune disease. In this article, we demonstrate that neither the 2F5 bnAb nor HIV MPER-KYNU cross-reactive Abs elicited by immunization with an MPER peptide-liposome vaccine in 2F5 bnAb VHDJH and VLJL knock-in mice and rhesus macaques modified KYNU activity or disrupted tissue tryptophan metabolism. Thus, molecular mimicry by HIV-1 Env that promotes the evasion of host anti-HIV-1 Ab responses can be directed toward nonfunctional host protein epitopes that do not impair host protein function. Therefore, the 2F5 HIV Env gp41 region is a key and safe target for HIV-1 vaccine development.
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Vacunas contra el SIDA/inmunología , Proteína gp41 de Envoltorio del VIH/metabolismo , Infecciones por VIH/inmunología , VIH-1/inmunología , Hidrolasas/metabolismo , Péptidos/metabolismo , Triptófano/metabolismo , Animales , Anticuerpos Neutralizantes/metabolismo , Reacciones Cruzadas , Anticuerpos Anti-VIH/metabolismo , Proteína gp41 de Envoltorio del VIH/genética , Proteína gp41 de Envoltorio del VIH/inmunología , Interacciones Huésped-Patógeno , Humanos , Hidrolasas/genética , Hidrolasas/inmunología , Evasión Inmune , Macaca mulatta , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Imitación Molecular , Péptidos/genética , Péptidos/inmunología , Vacunación , Vacunas de SubunidadRESUMEN
Levels of certain circulating short-chain dicarboxylacylcarnitine (SCDA), long-chain dicarboxylacylcarnitine (LCDA) and medium chain acylcarnitine (MCA) metabolites are heritable and predict cardiovascular disease (CVD) events. Little is known about the biological pathways that influence levels of most of these metabolites. Here, we analyzed genetics, epigenetics, and transcriptomics with metabolomics in samples from a large CVD cohort to identify novel genetic markers for CVD and to better understand the role of metabolites in CVD pathogenesis. Using genomewide association in the CATHGEN cohort (N = 1490), we observed associations of several metabolites with genetic loci. Our strongest findings were for SCDA metabolite levels with variants in genes that regulate components of endoplasmic reticulum (ER) stress (USP3, HERC1, STIM1, SEL1L, FBXO25, SUGT1) These findings were validated in a second cohort of CATHGEN subjects (N = 2022, combined p = 8.4x10-6-2.3x10-10). Importantly, variants in these genes independently predicted CVD events. Association of genomewide methylation profiles with SCDA metabolites identified two ER stress genes as differentially methylated (BRSK2 and HOOK2). Expression quantitative trait loci (eQTL) pathway analyses driven by gene variants and SCDA metabolites corroborated perturbations in ER stress and highlighted the ubiquitin proteasome system (UPS) arm. Moreover, culture of human kidney cells in the presence of levels of fatty acids found in individuals with cardiometabolic disease, induced accumulation of SCDA metabolites in parallel with increases in the ER stress marker BiP. Thus, our integrative strategy implicates the UPS arm of the ER stress pathway in CVD pathogenesis, and identifies novel genetic loci associated with CVD event risk.