High-resolution Metabolomics Profiling Research Articles

Metabolomic signatures of ideal cardiovascular health in black adults

Plasma metabolomics profiling is an emerging methodology to identify metabolic pathways underlying cardiovascular health (CVH). The objective of this study was to define metabolomic profiles underlying CVH in a cohort of Black adults, a population that is understudied but suffers from disparate levels of CVD risk factors. The Morehouse-Emory Cardiovascular (MECA) Center for Health Equity study cohort consisted of 375 Black adults (age 53 ± 10, 39% male) without known CVD. CVH was determined by the AHA Life’s Simple 7 (LS7) score, calculated from measured blood pressure, body mass index (BMI), fasting blood glucose and total cholesterol, and self-reported physical activity, diet, and smoking. Plasma metabolites were assessed using untargeted high-resolution metabolomics profiling. A metabolome wide association study (MWAS) identified metabolites associated with LS7 score after adjusting for age and sex. Using Mummichog software, metabolic pathways that were significantly enriched in metabolites associated with LS7 score were identified. Metabolites representative of these pathways were compared across clinical domains of LS7 score and then developed into a metabolomics risk score for prediction of CVH. We identified novel metabolomic signatures and pathways associated with CVH in a cohort of Black adults without known CVD. Representative and highly prevalent metabolites from these pathways included glutamine, glutamate, urate, tyrosine and alanine, the concentrations of which varied with BMI, fasting glucose, and blood pressure levels. When assessed in conjunction, these metabolites were independent predictors of CVH. One SD increase in the novel metabolomics risk score was associated with a 0.88 higher LS7 score, which translates to a 10.4% lower incident CVD risk. We identified novel metabolomic signatures of ideal CVH in a cohort of Black Americans, showing that a core group of metabolites central to nitrogen balance, bioenergetics, gluconeogenesis, and nucleotide synthesis were associated with CVH in this population.

Assessing Metabolic Differences Associated with Exposure to Polybrominated Biphenyl and Polychlorinated Biphenyls in the Michigan PBB Registry.

Polybrominated biphenyls (PBB) and polychlorinated biphenyls (PCB) are persistent organic pollutants with potential endocrine-disrupting effects linked to adverse health outcomes. In this study, we utilize high-resolution metabolomics (HRM) to identify internal exposure and biological responses underlying PCB and multigenerational PBB exposure for participants enrolled in the Michigan PBB Registry. HRM profiling was conducted on plasma samples collected from 2013 to 2014 from a subset of participants enrolled in the Michigan PBB Registry, including 369 directly exposed individuals (F0) who were alive when PBB mixtures were accidentally introduced into the food chain and 129 participants exposed to PBB in utero or through breastfeeding, if applicable (F1). Metabolome-wide association studies were performed for PBB-153 separately for each generation and (PCB-118, PCB-138, PCB-153, and PCB-180) in the two generations combined, as both had direct PCB exposure. Metabolite and metabolic pathway alterations were evaluated following a well-established untargeted HRM workflow. Mean levels were [standard deviation (SD): 13.9] for PBB-153 and (SD: 0.788) for . Sixty-two and 26 metabolic features were significantly associated with PBB-153 in F0 and F1 [false discovery rate (FDR) ], respectively. There were 2,861 features associated with (FDR ). Metabolic pathway enrichment analysis using a bioinformatics tool revealed perturbations associated with in numerous oxidative stress and inflammation pathways (e.g., carnitine shuttle, glycosphingolipid, and vitamin B9 metabolism). Metabolic perturbations associated with PBB-153 in F0 were related to oxidative stress (e.g., pentose phosphate and vitamin C metabolism) and in F1 were related to energy production (e.g., pyrimidine, amino sugars, and lysine metabolism). Using authentic chemical standards, we confirmed the chemical identity of 29 metabolites associated with levels (level 1 evidence). Our results demonstrate that serum PBB-153 is associated with alterations in inflammation and oxidative stress-related pathways, which differed when stratified by generation. We also found that was associated with the downregulation of important neurotransmitters, serotonin, and 4-aminobutanoate. These findings provide novel insights for future investigations of molecular mechanisms underlying PBB and PCB exposure on health. https://doi.org/10.1289/EHP12657.

Abstract 10677: A Systems Biology Approach Demonstrating the Association Between Mir 122-5p and Glutamine Metabolism With Cardiovascular Health in Black Adults: Results From the Morehouse-Emory Cardiovascular (meca) Center for Health Equity

Intro: Integrative analysis of extracellular microRNA (miRNA) and metabolomics is a novel approach to identifying molecular pathways underlying cardiovascular health (CVH). Levels of miRNAs are linked to cardiovascular disease (CVD), while cardiometabolic risk factors are known to alter activity of select metabolic pathways. We identified miRNAs and metabolites underlying CVH in a cohort of Black adults through an integrative analysis of extracellular miRNA levels, metabolite concentrations and clinical factors associated with CVH. Methods: The MECA cohort consisted of 371 Black adults (age 53+10, 38.5% male) without known CVD. CVH was determined by Life’s Simple 7 (LS7) score, calculated from blood pressure, fasting glucose, cholesterol, BMI, exercise, diet, and smoking. Metabolite concentrations in plasma was assessed by high-resolution metabolomics profiling, and expression of miRs-122-5p, -150-5p, and -30c-5p was assessed by RT-qPCR. Metabolome wide association study (MWAS) identified metabolites associated with LS7. Association of miRNA levels with CVH clinical domains was assessed using Spearman correlation. Integrative analysis of select miRNAs, metabolites, and CVH clinical domains was performed using the program xMWAS. Results: Expression of 30 metabolites was associated with improved CVH (FDR<0.2) where glutamine was higher (p=0.005), and glutamate was lower (p<0.001). Integrative analysis showed association between miR-122-5p, glutamine and fasting glucose. miR-122-5p expression independently correlated with fasting glucose (p=0.03) and glutamine/glutamate is known to be associated with glucose metabolism. In silico and in vitro analyses revealed glutamine synthetase as a potential target of miR-122-5p (Fig). Conclusions: We demonstrate novel associations between glutamine, miR-122-5p and fasting glucose in CVH, suggesting that select metabolites and miRNAs are markers of CVH and maybe potential therapeutic targets.

Abstract 12505: Patients With Heart Failure Living in Socioeconomically Deprived Neighborhoods Have Unique Metabolomic Profiles

Introduction: Patients living in neighborhoods with lower socioeconomic status have a greater risk for incident heart failure (HF), more severe symptoms, and increased risk of adverse clinical outcomes. We used high resolution metabolomics profiling to identify novel biomarkers associated with neighborhood socioeconomic status (nSES) in patients with HFrEF. Methods: The Area Deprivation Index (ADI) was used to characterize nSES in a discovery (n=170) and a validation (n=166) cohort of patients with HFrEF. Targeted and untargeted high-resolution plasma metabolomics profiling coupled with partial least-squares discriminant analysis (PLS-DA) was used to identify metabolites and metabolic pathways uniquely perturbed in patients in the highest tertile of the ADI (indicating lower nSES). Metabolites with a variable importance in projection (VIP) > 1 entered pathway enrichment analysis. Results: Compared to patients in the lower and middle ADI tertiles, patients with HFrEF living in the highest ADI tertile were more likely to be Black, and had higher body mass index and lower ejection fraction (all P < 0.01). PLS-DA confirmed metabolites that may be associated with worse diet quality in patients in both the discovery and validation cohorts who lived in neighborhoods in the highest ADI tertile, including amino acids and their metabolic products (carnitine, methionine, tryptophan, phenylalanine, valine, phenethylamine, indole), and urate. Moreover, metabolites associated with the human exposome (5-valerolactone, 1-naphthylamine) were also identified. Pathway enrichment analysis revealed branched-chain amino acid metabolism, fatty acid metabolism, and purine metabolism as part of this distinct metabolic signature ( Figure ). Conclusions: Patients with HFrEF living in neighborhoods with lower SES have a distinct metabolic signature that may, in part, be related to worse diet quality and more severe HF.

Abstract 12058: The Impact of Cardiovascular Health Intervention on Plasma Metabolomic Profiles

Introduction: Previously, we used plasma metabolomics profiling to identify metabolites underlying cardiovascular health (CVH) in participants of the Morehouse-Emory Cardiovascular (MECA) Center for Health Equity Study. Herein, we explored whether a health intervention could alter plasma concentrations of metabolites associated with CVH in MECA participants with poor CVH. Methods: 71 Black adults without known cardiovascular disease and with poor CVH, defined as AHA Life’s Simple 7 (LS7) score <8, were given a technology-enabled behavioral intervention platform (Health360x) for 6 months with or without access to a health coach. Metabolites were assessed pre- and post-intervention by untargeted high-resolution metabolomics profiling. Metabolome wide association study (MWAS) was conducted to identify differentially expressed metabolites and Mummichog was used to identify metabolic pathways that were differentially enriched after the intervention. Annotations were performed by matching to an in-house library of confirmed metabolites. Paired t-test and Wilcoxon signed-rank test were used to compare clinical metrics. Results: Mean age was 55 + 9.0 years, 69% female. Total LS7 scores improved from 6.2 ( + 1.49) to 6.5 ( + 1.74) with the intervention. While total and subcomponent LS7 scores and clinical metrics (BMI, blood pressure, glucose and cholesterol levels) trended toward improvement, the changes were not statistically significant. MWAS identified 18 metabolites that were significantly changed after intervention, including glutamine and glutamate. Pathway analysis demonstrated 30 metabolic pathways that were significantly changed with intervention, including glutamate, aspartate, asparagine, arginine and proline metabolism. Conclusions: Six-months of lifestyle intervention altered activity of 30 metabolic pathways without significant alterations in the clinical metrics. These metabolites and pathways appear to be indicators of a healthier lifestyle in the Black population, potentially supporting their use as markers of CVH and possible therapeutic targets.

Metabolic changes associated with polybrominated biphenyls and polychlorinated biphenyls in the Michigan PBB registry

Background: Polybrominated Biphenyls (PBBs) and Polychlorinated Biphenyls (PCBs) are endocrine-disrupting chemicals (EDCs). In Michigan, people were exposed to PBBs during a time-limited contamination event in the 1970s and are continuously exposed to PCBs. Using high-resolution metabolomics (HRM), this study aimed to identify biological mechanisms underlying human health effects of PBB and PCB exposure. Methods: HRM profiling was conducted on serum samples from the Michigan PBB Registry collected from a subset of 500 individuals representing both F0 (directly exposed to PBB) and F1 (exposed through parents) generations from 2011 to 2014. This study measured PBB-153 stratified by generation and ƩPCB (PCB-118, PCB-138, PCB-153, and PCB-180) in the total combined subset (as all experienced direct PCB exposure). Metabolite and metabolic pathway perturbation were evaluated using an untargeted HRM workflow. Results: Both exposure measures had high detection levels. Mean levels were 1.75-ng/mL (SD: 13.9) for PBB-153 and 1.04-ng/mL (SD: 0.788) for ΣPCBs. 124 and 86 metabolomic features were significantly associated with PBB-153 in F0 and F1 (p<0.005), respectively. There were 2,861 features associated with ΣPCB (FDR corrected p<0.2). Pathway enrichment analysis revealed perturbations associated with ΣPCB in numerous oxidative stress and inflammation pathways (e.g., carnitine shuttle, glycosphingolipid, and vitamin B9 metabolism). Perturbations associated with PBB-153 in F0 were related to oxidative stress pathways (e.g., pentose phosphate and vitamin C metabolism) and in F1 were related to energy production (e.g., pyrimidine, aminosugars, and lysine metabolism). Authentic chemical standards were used to confirm the chemical identity of 29 metabolites associated with ΣPCB levels and 10 metabolites associated with PBB-153 levels. Conclusions: Our results demonstrated that serum PBB-153 and ΣPCB levels were associated with perturbations in inflammation and oxidative stress-related pathways, which differed when stratified by generation. These findings support future investigations of molecular mechanisms underlying PBB and PCB exposure on health, emphasizing exposure timing.

Assessment of metabolic perturbations associated with exposure to phthalates among pregnant African American women

BackgroundPhthalates have been linked with numerous harmful health effects. Limited data are available on the molecular mechanism underlying phthalate toxicity on human health. In this study, we measured urinary phthalate metabolites and used high-resolution metabolomics (HRM) to identify biological perturbations associated with phthalate exposures among pregnant African American (AA) women, who are disproportionately exposed to high phthalates levels. MethodsWe used untargeted HRM profiling to characterize serum samples collected during early (8–14 weeks gestation) and late (24–30 weeks gestation) pregnancy from 73 participants from the Atlanta AA Maternal-Child cohort. We measured eight urinary phthalate metabolites in early and late pregnancy, including Monoethyl phthalate (MEP), Mono(2-ethlyhexyl) phthalate (MEHP), and Mono (2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), to assess maternal exposures to phthalates. Metabolite and metabolic pathway perturbation were evaluated using an untargeted HRM workflow. ResultsGeometric mean creatinine-adjusted levels of urinary MEP, MEHP, and MEHHP were 67.3, 1.4, and 4.1 μg/g creatinine, respectively, with MEP and MEHP higher than the mean levels of non-Hispanic blacks in the general US population (2015–2016). There were 73 and 1435 metabolic features significantly associated with at least one phthalate metabolite during early and late pregnancy (p < 0.005), respectively. Pathway enrichment analysis revealed perturbations in four inflammation- and oxidative-stress-related pathways associated with phthalate metabolite levels during both early and late pregnancy, including glycerophospholipid, urea cycle, arginine, and tyrosine metabolism. We confirmed 10 metabolites with level-1 evidence, which are associated with urinary phthalates, including thyroxine and thiamine, which were negatively associated with MEP, as well as tyramine and phenethylamine, which were positively associated with MEHP and MEHHP. ConclusionOur results demonstrated that urinary phthalate levels were associated with perturbations in biological pathways connected with inflammation, oxidative stress, and endocrine disruption. The findings support future targeted investigations on molecular mechanisms underlying the impact of maternal phthalates exposure on adverse health outcomes.

Assessment of metabolic perturbations associated with prenatal phthalate exposure among pregnant African American women

BACKGROUND AND AIM: Phthalates have been linked with numerous harmful health effects. Limited data are available on the molecular mechanism underlying phthalate toxicity on human health. In this analysis, we measured urinary phthalate metabolites and conducted high-resolution metabolomics (HRM) to identify biological perturbations associated with phthalate exposures among pregnant African American (AA) women, who are disproportionately exposed to high phthalates levels. METHODS: We used untargeted HRM profiling to characterize serum samples collected during early (8-14 weeks gestation) and late (24-30 weeks gestation) pregnancy from 73 participants from the Atlanta AA Maternal-Child cohort. We measured 8 urinary phthalate metabolites in early and late pregnancy, including Monoethyl phthalate (MEP), Mono-n-butyl phthalate (MBP), Mono(2-ethlyhexyl) phthalate (MEHP), and Mono (2-ethyl-5-hydroxyhexyl phthalate (MEHHP), to assess maternal exposures to phthalates. Metabolite and metabolic pathway perturbation were evaluated using an untargeted HRM workflow. RESULTS:Geometric mean creatinine-adjusted levels of urinary MEP, MBP, MEHP, and MEHHP were 67.3, 6.6, 1.4, and 4.1 μg/g creatinine, respectively, with MEP and MEHP higher than the mean levels of Non-Hispanic blacks in the general US population (2015-2016). There were 814 and 1,435 metabolic features significantly associated with at least one phthalate metabolites during early and late pregnancy, respectively. Metabolic pathway enrichment analysis revealed perturbations in four inflammation- and oxidative stress-related pathways associated with phthalate metabolite levels during both early and late pregnancy, including glycerophospholipid, urea cycle, arginine, and tyrosine metabolism. We confirmed 10 metabolites associated with urinary phthalates, including thyroxine and thiamine, which were negatively associated with MEP, as well as tyramine and phenethylamine, which were positively associated with MEHP and MEHHP. CONCLUSIONS:Our results demonstrate that urinary phthalate levels are associated with perturbations in biological pathways connected with inflammation and oxidative stress. The findings support future hypothesis-testing investigations on potential molecular mechanisms underlying the impact of maternal phthalates exposure on adverse health outcomes. KEYWORDS: Phthalates, Metabolomics, Prenatal Phthalate Exposures, Biological Pathway

High-resolution metabolomics of exposure to tobacco smoke during pregnancy and adverse birth outcomes in the Atlanta African American Maternal-Child cohort

BACKGROUND AND AIM: Exposure to tobacco smoke during pregnancy has been associated with a series of adverse reproductive outcomes; however, the underlying molecular mechanisms are not well-established. In this analysis, we measured urinary cotinine, a widely used biomarker of tobacco exposure, and conducted high-resolution metabolomics (HRM) to identify biological perturbations associated with prenatal tobacco smoke exposures and adverse birth outcomes. METHODS: We collected early and late pregnancy urine samples for cotinine measurement and serum samples for HRM profiling from 105 pregnant women from the Atlanta African American Maternal-Child cohort (2014-2016). Using an untargeted HRM workflow, we investigated how the biological perturbations in maternal metabolome mediate the association between prenatal smoke exposures and adverse birth outcomes (preterm birth, early term birth vs. full term birth; gestational age at birth) using a meet-in-the-middle approach. RESULTS:The median maternal urinary cotinine level was 4.77 ug/g creatinine, with 29 subjects higher than 100 ug/g creatinine. In total, 16,481 and 13,043 metabolic features were extracted from serum samples using hilic and c18 columns, respectively. Thirteen metabolic pathways were found to be associated with cotinine level and adverse birth outcomes during early and late pregnancy, including tryptophan, histidine, urea cycle, arginine, and proline metabolism. We confirmed 47 metabolites associated with cotinine exposure, preterm birth, and shorter gestational length, which include glutamate, serine, choline, and taurine; these metabolites are closely involved in endogenous inflammation, vascular reactivity, and lipid peroxidation processes. CONCLUSIONS:The metabolic perturbations associated with cotinine exposure were closely connected within a metabolic network related to inflammation, oxidative stress, placental vascularization, and insulin action, which could contribute to shorter gestations. The findings support the future development of targeted interventions to reduce adverse birth outcomes associated with tobacco smoke exposure, especially among African American who are disproportionately exposed to high tobacco smoke and experience higher rates of adverse birth outcomes. KEYWORDS: Tobacco Smoke Exposures, Metabolomics, Birth Outcomes, Preterm Birth

Application of high-resolution metabolomics to identify biological pathways perturbed by traffic-related air pollution

BackgroundSubstantial research has investigated the adverse effects of traffic-related air pollutants (TRAP) on human health. Convincing associations between TRAP and respiratory and cardiovascular diseases are known, but the underlying biological mechanisms are not well established. High-resolution metabolomics (HRM) is a promising platform for untargeted characterization of molecular mechanisms between TRAP and health indexes. ObjectivesWe examined metabolic perturbations associated with short-term exposures to TRAP, including carbon monoxide (CO), nitrogen dioxide (NO2), ozone (O3), fine particulate matter (PM2.5), organic carbon (OC), and elemental carbon (EC) among 180 participants of the Center for Health Discovery and Well-Being (CHDWB), a cohort of Emory University-affiliated employees. MethodsA cross-sectional study was conducted on baseline visits of 180 CHDWB participants enrolled during 2008–2012, in whom HRM profiling was determined in plasma samples using liquid chromatography-high-resolution mass spectrometry with positive and negative electrospray ionization (ESI) modes. Ambient pollution concentrations were measured at an ambient monitor near downtown Atlanta. Metabolic perturbations associated with TRAP exposures were assessed following an untargeted metabolome-wide association study (MWAS) framework using feature-specific Tobit regression models, followed by enriched pathway analysis and chemical annotation. ResultsSubjects were predominantly white (76.1%) and non-smokers (95.6%), and all had at least a high school education. In total, 7821 and 4123 metabolic features were extracted from the plasma samples by the negative and positive ESI runs, respectively. There are 3421 features significantly associated with at least one air pollutant by negative ion mode, and 1691 features by positive ion mode. Biological pathways enriched by features associated with the pollutants are primarily involved in nucleic acids damage/repair (e.g., pyrimidine metabolism), nutrient metabolism (e.g., fatty acid metabolism), and acute inflammation (e.g., histidine metabolism and tyrosine metabolism). NO2 and EC were associated most consistently with these pathways. We confirmed the chemical identity of 8 metabolic features in negative ESI and 2 features in positive ESI, including metabolites closely linked to oxidative stress and inflammation, such as histamine, tyrosine, tryptophan, and proline. ConclusionsWe identified a range of ambient pollutants, including components of TRAP, associated with differences in the metabolic phenotype among the cohort of 180 subjects. We found Tobit models to be a robust approach to handle missing data among the metabolic features. The results were encouraging of further use of HRM and MWAS approaches for characterizing molecular mechanisms underlying exposure to TRAP.

Abstract 14230: Integration of Vascular Phenotyping With Metabolomic Profiling in Black Subjects With Heart Failure With Reduced Ejection Fraction

Introduction: Impaired vascular function in blacks contributes to a higher risk of heart failure (HF) compared to other race/ethnicities. Hypothesis: Black patients with HF with reduced ejection fraction (HFrEF) will have worse digital microvascular function measured using peripheral arterial tonometry (PAT). High resolution metabolomics profiling will identify novel biomarkers of vascular function. Methods: PAT was used to estimate the reactive hyperemia index (RHI) in blacks and whites with HFrEF (N=154, age: 53.7 ± 13.0 yrs, 48.7% female, 61.0% black) and healthy controls (N=200, age: 43.2 ± 14.0 yrs, 47.0% female, 27.0% black). Linear regression was used to determine if race was associated with RHI after adjustment for traditional CV risk factors. High-resolution plasma metabolomics profiling and pathway analysis, followed by metabolite confirmation with mass spectrometry were used to derive a metabolomics score (MS) from metabolites that were significantly associated with RHI, different between blacks and whites, and attenuated the association of black race with RHI. Results: Black subjects were younger in both the HFrEF and control cohorts. Blacks with HFrEF were more likely to have nonischemic HF and hypertension, more likely to be on hydralazine-nitrates and diuretics. RHI was lower in blacks than whites both in subjects with HFrEF (1.8 ± 0.5 vs. 2.0 ± 0.5, P=0.02) and in healthy controls (2.1 ± 0.5 vs. 2.4 ± 0.5, P=0.003). Black race was independently associated with lower RHI (adjusted β=-0.221, P=0.03). MS comprising metabolites representative of cardiac cachexia (3-Methyl-Histidine, L-Histidine, Creatinine), vascular collagen turnover (4-hydroxyproline), purine metabolism and oxidative stress (uric acid) attenuated the association of black race with RHI by 49.8%. Conclusion: Integration of vascular phenotyping with metabolomic profiling reveals a novel MS that attenuates the association of black race with impaired microvascular function.

Abstract P192: Integrative Analysis of Extracellular Molecular Profiles Associated With Cardiovascular Health in Black Americans: Results From the Morehouse-Emory Cardiovascular (MECA) Center for Health Equity

Introduction: While cardiovascular disease (CVD) morbidity and mortality is particularly pronounced among Black Americans, there is a great deal of intra-racial heterogeneity within the population. Our objective was to identify novel circulating biomarkers (extracellular miRNA and metabolites) that predict cardiovascular health (CVH) within Blacks, while providing insight into CVD pathophysiology. Hypothesis: We hypothesize that an integrative analysis of miRNA and metabolomics profiles will enable a systems biology approach to understanding CVH as defined by the American Heart Association's Life’s Simple 7 (LS7) score within Blacks. Methods: Platelet free plasma (PFP) was collected from 382 Black adults (age 53 + 10, 40% male) without known CVD living in Atlanta, GA. CVH was determined by LS7 scores calculated from measured blood pressure, blood glucose, cholesterol, body mass index (BMI), and self-reported exercise, diet, and smoking. In the discovery phase, next generation sequencing was performed on PFP samples from 20 participants with low CVH (LS7 &lt; 6) and 20 with high CVH (LS7 &gt; 10). DESeq was used to identify differentially expressed miRNAs. In the validation phase, RT-qPCR was used to assess levels of eight miRNAs in 382 samples. Spearman correlation and linear regression analyses were performed to assess ability of miRNA levels to predict LS7. High-resolution metabolomics profiling was performed on all 382 samples. Integrative analysis of miRNA, metabolomics profiles, and clinical domains of CVH (LS7) was performed using the program xMWAS to determine connectivity among these markers. Results: RNA sequencing identified 13 extracellular miRNAs differentially expressed between low CVH and high CVH (FDR &lt; 0.05). Analysis of data from validation phase found the expression of four extracellular miRNAs (miRs-122, -150, -30c, -769-3p) significantly correlated with LS7. Metabolome wide association study (MWAS) identified 141 features that were differentially expressed between low and high CVH with false discovery rate of &lt;0.2: 54 features were lower in low LS7, and 87 were higher in low LS7. These metabolomics features were enriched in 19 metabolic pathways, including glutathione metabolism, alanine and aspartate metabolism, and methionine and cysteine metabolism. Integrative analysis revealed 6 clusters in which differentially expressed miRNAs, metabolites and clinical domains of CVH were connected. Conclusions: CVH in Blacks is associated with distinct extracellular miRNA and metabolomics profiles, and these molecular profiles are associated with pathways linked to vascular dysfunction. Integrative analysis revealed connectivity between miRNA-metabolome networks and clinical domains of CVH. This novel method represents an unique opportunity to gain insights into epigenetic and environmental influences on CVD disparities.

Reprint of “Metabolome Wide Association Study of Serum Poly and Perfluoroalkyl Substances (PFASs) in Pregnancy and Early Postpartum”

High-resolution metabolomics (HRM) profiling of metabolic fingerprints can improve understanding of how poly and perfluoroalkyl substances (PFASs) induce metabolic alterations of in utero environment and impact fetal health. HRM profiling and quantification of PFASs were performed for 397 maternal perinatal serum samples collected from 1959-1967 in the Child Health and Development Studies (CHDS). We used Metabolome-Wide Association Studies (MWAS) and pathway enrichment analysis for metabolic associations with PFOS, its precursor EtFOSAA, and EtFOSAA-to-PFOS ratio. Distinct metabolic profiles were found with EtFOSAA and PFOS. Urea cycle metabolites such as arginine, lysine and creatine had opposite associations with EtFOSAA (negative) and PFOS (positive); whereas, carnitine shuttle metabolites were found to be exclusively and positively associated with PFOS indicating perturbation in fatty acid metabolism. These differential metabolic associations for precursor and end-product represent an important first step in identifying how PFASs alter the in utero environment and potentially leads to disease risk.

Metabolic GWAS of elite athletes reveals novel genetically-influenced metabolites associated with athletic performance

Genetic research of elite athletic performance has been hindered by the complex phenotype and the relatively small effect size of the identified genetic variants. The aims of this study were to identify genetic predisposition to elite athletic performance by investigating genetically-influenced metabolites that discriminate elite athletes from non-elite athletes and to identify those associated with endurance sports. By conducting a genome wide association study with high-resolution metabolomics profiling in 490 elite athletes, common variant metabolic quantitative trait loci (mQTLs) were identified and compared with previously identified mQTLs in non-elite athletes. Among the identified mQTLs, those associated with endurance metabolites were determined. Two novel genetic loci in FOLH1 and VNN1 are reported in association with N-acetyl-aspartyl-glutamate and Linoleoyl ethanolamide, respectively. When focusing on endurance metabolites, one novel mQTL linking androstenediol (3alpha, 17alpha) monosulfate and SULT2A1 was identified. Potential interactions between the novel identified mQTLs and exercise are highlighted. This is the first report of common variant mQTLs linked to elite athletic performance and endurance sports with potential applications in biomarker discovery in elite athletic candidates, non-conventional anti-doping analytical approaches and therapeutic strategies.

Untargeted high-resolution metabolomics to measure and describe the “perfluorome”

OPS 59: The Exposome: progress in methods and applications, Room 412, Floor 4, August 28, 2019, 1:30 PM - 3:00 PM Background/Aim: Poly- and perfluorinated alkyl substances (PFAS) are used in industrial processes and consumer products. Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS), two PFAS, have been phased out of use in the United States because of their biological and environmental persistence, widespread detection in human sera, and concern over adverse health effects. However, other PFAS have not been well studied. Thus, we aimed to describe exposure to a suite of PFAS – the perfluorome – in order to characterize profiles of exposure to a broad range of PFAS. Methods: We quantified serum concentrations of six PFAS with targeted methods, and conducted untargeted high-resolution metabolomics profiling of serum from 114 8-year old children from Cincinnati, Ohio. We performed Principal Component Analysis (PCA) to characterize serum PFAS profiles. Results: We annotated 178 PFAS measured by untargeted methods and categorized 137 them into families based on their chemical structures. The first three principle components (PC) explained 20% of the variation of these 137 PFAS. Fluorotelomer-related compounds loaded strongly on the first three PCs. Perfluoroalkyl carbonyls, including PFOA, also loaded strongly on PC2. PFOS loaded strongly on PC5, in addition to perfluorohexane sulfonic acid (PFHxS), and perfluorodecanoic acid (PFDA). Notably, correlations between targeted and untargeted methods were strong (r ≥ 0.9), except for PFOA (r = 0.45) and perfluorononanoic acid (PFNA; r = 0.24). Conclusions: In this cohort, we tentatively identified 178 different PFAS in 8-year old children’s serum. Two families of PFAS (fluorotelomer-related compounds and perfluoroalkyl carbonyls), representing exposure to chemicals used in surfactant and surface protection products and their production, were important in explaining the variance of the perfluorome. Future studies should evaluate the potential health risks associated with exposure to these other PFAS.

Metabolome Wide Association Study of Serum Poly and Perfluoroalkyl Substances (PFASs) in Pregnancy and Early Postpartum

High-resolution metabolomics (HRM) profiling of metabolic fingerprints can improve understanding of how poly and perfluoroalkyl substances (PFASs) induce metabolic alterations of in utero environment and impact fetal health. HRM profiling and quantification of PFASs were performed for 397 maternal perinatal serum samples collected from 1959-1967 in the Child Health and Development Studies (CHDS). We used Metabolome-Wide Association Studies (MWAS) and pathway enrichment analysis for metabolic associations with PFOS, its precursor EtFOSAA, and EtFOSAA-to-PFOS ratio. Distinct metabolic profiles were found with EtFOSAA and PFOS. Urea cycle metabolites such as arginine, lysine and creatine had opposite associations with EtFOSAA (negative) and PFOS (positive); whereas, carnitine shuttle metabolites were found to be exclusively and positively associated with PFOS indicating perturbation in fatty acid metabolism. These differential metabolic associations for precursor and end-product represent an important first step in identifying how PFASs alter the in utero environment and potentially leads to disease risk.

Perturbations of the arginine metabolome following exposures to traffic-related air pollution in a panel of commuters with and without asthma

BackgroundMechanisms underlying the effects of traffic-related air pollution on people with asthma remain largely unknown, despite the abundance of observational and controlled studies reporting associations between traffic sources and asthma exacerbation and hospitalizations. ObjectivesTo identify molecular pathways perturbed following traffic pollution exposures, we analyzed data as part of the Atlanta Commuters Exposure (ACE-2) study, a crossover panel of commuters with and without asthma. MethodsWe measured 27 air pollutants and conducted high-resolution metabolomics profiling on blood samples from 45 commuters before and after each exposure session. We evaluated metabolite and metabolic pathway perturbations using an untargeted metabolome-wide association study framework with pathway analyses and chemical annotation. ResultsMost of the measured pollutants were elevated in highway commutes (p < 0.05). From both negative and positive ionization modes, 17,586 and 9087 metabolic features were extracted from plasma, respectively. 494 and 220 unique features were associated with at least 3 of the 27 exposures, respectively (p < 0.05), after controlling confounders and false discovery rates. Pathway analysis indicated alteration of several inflammatory and oxidative stress related metabolic pathways, including leukotriene, vitamin E, cytochrome P450, and tryptophan metabolism. We identified and annotated 45 unique metabolites enriched in these pathways, including arginine, histidine, and methionine. Most of these metabolites were not only associated with multiple pollutants, but also differentially expressed between participants with and without asthma. The analysis indicated that these metabolites collectively participated in an interrelated molecular network centering on arginine metabolism, underlying the impact of traffic-related pollutants on individuals with asthma. ConclusionsWe detected numerous significant metabolic perturbations associated with in-vehicle exposures during commuting and validated metabolites that were closely linked to several inflammatory and redox pathways, elucidating the potential molecular mechanisms of traffic-related air pollution toxicity. These results support future studies of metabolic markers of traffic exposures and the corresponding molecular mechanisms.

Use of high-resolution metabolomics for the identification of metabolic signals associated with traffic-related air pollution

BackgroundHigh-resolution metabolomics (HRM) is emerging as a sensitive tool for measuring environmental exposures and biological responses. The aim of this analysis is to assess the ability of high-resolution metabolomics (HRM) to reflect internal exposures to complex traffic-related air pollution mixtures. MethodsWe used untargeted HRM profiling to characterize plasma and saliva collected from participants in the Dorm Room Inhalation to Vehicle Emission (DRIVE) study to identify metabolic pathways associated with traffic emission exposures. We measured a suite of traffic-related pollutants at multiple ambient and indoor sites at varying distances from a major highway artery for 12 weeks in 2014. In parallel, 54 students living in dormitories near (20 m) or far (1.4 km) from the highway contributed plasma and saliva samples. Untargeted HRM profiling was completed for both plasma and saliva samples; metabolite and metabolic pathway alternations were evaluated using a metabolome-wide association study (MWAS) framework with pathway analyses. ResultsWeekly levels of traffic pollutants were significantly higher at the near dorm when compared to the far dorm (p < 0.05 for all pollutants). In total, 20,766 metabolic features were extracted from plasma samples and 29,013 from saliva samples. 45% of features were detected and shared in both plasma and saliva samples. 1291 unique metabolic features were significantly associated with at least one or more traffic indicator, including black carbon, carbon monoxide, nitrogen oxides and fine particulate matter (p < 0.05 for all significant features), after controlling for confounding and false discovery rate. Pathway analysis of metabolic features associated with traffic exposure indicated elicitation of inflammatory and oxidative stress related pathways, including leukotriene and vitamin E metabolism. We confirmed the chemical identities of 10 metabolites associated with traffic pollutants, including arginine, histidine, γ‑linolenic acid, and hypoxanthine. ConclusionsUsing HRM, we identified and verified biological perturbations associated with primary traffic pollutant in panel-based setting with repeated measurement. Observed response was consistent with endogenous metabolic signaling related to oxidative stress, inflammation, and nucleic acid damage and repair. Collectively, the current findings provide support for the use of untargeted HRM in the development of metabolic biomarkers of traffic pollution exposure and response.

Metabolomic profiling associated with deployment‐related stressors in Army personnel

Pre‐deployment identification of risk and resilience factors is crucial in developing targets to reduce or prevent posttraumatic stress symptoms in military personnel. The Fort Campbell Cohort study was designed to assess pre‐deployment biological and behavioral markers and build predictive models to identify risk and resistance for posttraumatic stress disorder (PTSD) following deployment. The aim of the current study was to use high‐resolution metabolomics profiling to identify metabolic pathways and networks associated with PTSD checklist score differences and changes across multiple pre and post‐deployment time points. In addition, we have investigated how deployment affects metabolomics profile changes within individuals independent of PTSD score changes. Untargeted metabolomics profiling of plasma has been completed using both liquid and gas chromatography with mass spectrometry. Our preliminary data indicates that deployment has complex metabolic effects that must be considered in evaluation of deployment‐associated exposures in military personnel. Our in depth‐data analysis may further elucidate pathways, novel compounds, and biomarkers associated with PTSD in its relation to military deployment. These findings may have clinical implications for understanding the pathogenesis of PTSD and provide insights to avert chronic PTSD.Disclaimers: Research was conducted in compliance with all Federal requirements. The views expressed are those of the authors and do not constitute endorsement by the U.S. ArmySupport or Funding InformationFunding support from Military Operational Medicine Research Program, MOMRP is highly acknowledged.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Human Suction Blister Fluid Composition Determined Using High-Resolution Metabolomics.

Interstitial fluid (ISF) surrounds the cells and tissues of the body. Since ISF has molecular components similar to plasma, as well as compounds produced locally in tissues, it may be a valuable source of biomarkers for diagnostics and monitoring. However, there has not been a comprehensive study to determine the metabolite composition of ISF and to compare it to plasma. In this study, the metabolome of suction blister fluid (SBF), which largely consists of ISF, collected from 10 human volunteers was analyzed using untargeted high-resolution metabolomics (HRM). A wide range of metabolites were detected in SBF, including amino acids, lipids, nucleotides, and compounds of exogenous origin. Various systemic and skin-derived metabolite biomarkers were elevated or found uniquely in SBF, and many other metabolites of clinical and physiological significance were well correlated between SBF and plasma. In sum, using untargeted HRM profiling, this study shows that SBF can be a valuable source of information about metabolites relevant to human health.