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Background The interplay between branched‐chain amino acid (BCAA) metabolism, an important pathway in adiposity and cardiometabolic disease, and visceral adipose depots such as hepatic steatosis (HS) and epicardial adipose tissue is unknown. We leveraged the PROMISE clinical trial with centrally adjudicated coronary computed tomography angiography imaging to determine relationships between adipose depots, BCAA dysregulation, and coronary artery disease (CAD). Methods and Results The PROMISE (Prospective Multicenter Imaging Study for Evaluation of Chest Pain) trial randomized 10 003 outpatients with stable chest pain to computed tomography angiography versus standard‐of‐care diagnostics. For this study, we included 1798 participants with available computed tomography angiography data and biospecimens. Linear and logistic regression were used to determine associations between a molar sum of BCAAs measured by nuclear magnetic resonance spectroscopy with body mass index, adipose traits, and obstructive CAD. Mendelian randomization was then used to determine if BCAAs are in the causal pathway for adipose depots or CAD. The study sample had a mean age of 60 years (SD, 8.0), body mass index of 30.6 (SD, 5.9), and epicardial adipose tissue volume of 57.3 (SD, 21.3) cm 3 /m 2 ; 27% had HS, and 14% had obstructive CAD. BCAAs were associated with body mass index (multivariable beta 0.12 per SD increase in BCAA [95% CI, 0.08–0.17]; P =4×10 −8 ). BCAAs were also associated with HS (multivariable odds ratio [OR], 1.46 per SD increase in BCAAs [95% CI, 1.28–1.67]; P =2×10 −8 ), but BCAAs were associated only with epicardial adipose tissue volume (odds ratio, 1.18 [95% CI, 1.07–1.32]; P =0.002) and obstructive CAD (OR, 1.18 [95% CI, 1.04–1.34]; P =0.009) in univariable models. Two‐sample Mendelian randomization did not support the role of BCAAs as within the causal pathways for HS or CAD. Conclusions BCAAs have been implicated in the pathogenesis of cardiometabolic diseases, and adipose depots have been associated with the risk of CAD. Leveraging a large clinical trial, we further establish the role of dysregulated BCAA catabolism in HS and CAD, although BCAAs did not appear to be in the causal pathway of either disease. This suggests that BCAAs may serve as an independent circulating biomarker of HS and CAD but that their association with these cardiometabolic diseases is mediated through other pathways.

This study examined struggles to establish autonomy and relatedness with peers in adolescence and early adulthood as predictors of advanced epigenetic aging assessed at age 30. Participants (N = 154; 67 male and 87 female) were observed repeatedly, along with close friends and romantic partners, from ages 13 through 29. Observed difficulty establishing close friendships characterized by mutual autonomy and relatedness from ages 13 to 18, an interview-assessed attachment state of mind lacking autonomy and valuing of attachment at 24, and self-reported difficulties in social integration across adolescence and adulthood were all linked to greater epigenetic age at 30, after accounting for chronological age, gender, race, and income. Analyses assessing the unique and combined effects of these factors, along with lifetime history of cigarette smoking, indicated that each of these factors, except for adult social integration, contributed uniquely to explaining epigenetic age acceleration. Results are interpreted as evidence that the adolescent preoccupation with peer relationships may be highly functional given the relevance of such relationships to long-term physical outcomes.

BACKGROUND More than half of major adverse cardiovascular events (MACE) occur in the absence of obstructive coronary artery disease and are often attributed to the rupture of high‐risk coronary atherosclerotic plaque (HRP). Blood‐based biomarkers that associate with imaging‐defined HRP and predict MACE are lacking. METHODS AND RESULTS Nuclear magnetic resonance–based lipoprotein particle profiling was performed in the biomarker substudy of the PROMISE (Prospective Multicenter Imaging Study for Evaluation of Chest Pain) trial (N=4019) in participants who had stable symptoms suspicious for coronary artery disease. Principal components analysis was used to reduce the number of correlated lipoproteins into uncorrelated lipoprotein factors. The association of lipoprotein factors and individual lipoproteins of significantly associated factors with core laboratory determined coronary computed tomographic angiography features of HRP was determined using logistic regression models. The association of HRP‐associated lipoproteins with MACE was assessed in the PROMISE trial and validated in an independent coronary angiography biorepository (CATHGEN [Catheterization Genetics]) using Cox proportional hazards models. Lipoprotein factors composed of high‐density lipoprotein (HDL) subclasses were associated with HRP. In these factors, large HDL (odds ratio [OR], 0.70 [95% CI, 0.56–0.85]; P P =0.028) and HDL size (OR, 0.82 [95% CI, 0.69–0.96]; P =0.018) were associated with HRP in multivariable models. Medium HDL was associated with MACE in PROMISE (hazard ratio [HR], 0.76 [95% CI, 0.63–0.92]; P =0.004), which was validated in the CATHGEN biorepository (HR, 0.91 [95% CI, 0.88–0.94]; P CONCLUSIONS Large and medium HDL subclasses and HDL size inversely associate with HRP features, and medium HDL subclasses inversely associate with MACE in PROMISE trial participants. These findings may aid in the risk stratification of individuals with chest pain and provide insight into the pathobiology of HRP. REGISTRATION URL: https://clinicaltrials.gov ; Unique identifier: NCT01174550

Epigenetic clocks provide powerful tools for estimating health and lifespan but their ability to predict brain degeneration and neuronal damage during the aging process is unknown. In this study, we use GrimAge, an epigenetic clock correlated to several blood plasma proteins, to longitudinally investigate brain cellular microstructure in axonal white matter from a cohort of healthy aging individuals. Given the blood plasma correlations used to develop GrimAge, a specific focus was made on white matter hyperintensities, a visible neurological manifestation of small vessel disease, and the axonal pathways throughout each individual’s brain affected by their unique white matter hyperintensity location and volume. 98 subjects over 55 years of age were scanned at baseline with 41 returning for a follow-up scan 2 years later. Using diffusion MRI lesionometry, we reconstructed subject-specific networks of affected axonal tracts and examined the diffusion cellular microstructure composition of these areas, both at baseline and longitudinally, for evidence of cellular degeneration. A chronological age-adjusted version of GrimAge was significantly correlated with baseline WMH volume and markers of neuronal decline, indicated by increased extracellular free water, increased intracellular signal, and decreased axonal signal within WMH. By isolating subject-specific axonal regions ‘lesioned’ by crossing through a WMH, age-adjusted GrimAge was also able to predict longitudinal development of similar patterns of neuronal decline throughout the brain. This study is the first to establish a relationship between accelerated epigenetic GrimAge and brain cellular microstructure in humans.

Oxytocin (OT), the brain's most abundant neuropeptide, plays an important role in social salience and motivation. Clinical trials of the efficacy of OT in autism spectrum disorder (ASD) have reported mixed results due in part to ASD's complex etiology. We investigated whether genetic and epigenetic variation contribute to variable endogenous OT levels that modulate sensitivity to OT therapy. To carry out this analysis, we integrated genome-wide profiles of DNA-methylation, transcriptional activity, and genetic variation with plasma OT levels in 290 participants with ASD enrolled in a randomized controlled trial of OT. Our analysis identified genetic variants with novel association with plasma OT, several of which reside in known ASD risk genes. We also show subtle but statistically significant association of plasma OT levels with peripheral transcriptional activity and DNA-methylation profiles across several annotated gene sets. These findings broaden our understanding of the effects of the peripheral oxytocin system and provide novel genetic candidates for future studies to decode the complex etiology of ASD and its interaction with OT signaling and OT-based interventions. LAY SUMMARY: Oxytocin (OT) is an abundant chemical produced by neurons that plays an important role in social interaction and motivation. We investigated whether genetic and epigenetic factors contribute to variable OT levels in the blood. To this, we integrated genetic, gene expression, and non-DNA regulated (epigenetic) signatures with blood OT levels in 290 participants with autism enrolled in an OT clinical trial. We identified genetic association with plasma OT, several of which reside in known autism risk genes. We also show statistically significant association of plasma OT levels with gene expression and epigenetic across several gene pathways. These findings broaden our understanding of the factors that influence OT levels in the blood for future studies to decode the complex presentation of autism and its interaction with OT and OT-based treatment.

BACKGROUND: Experimental studies and small clinical trials have suggested that treatment with intranasal oxytocin may reduce social impairment in persons with autism spectrum disorder. Oxytocin has been administered in clinical practice to many children with autism spectrum disorder. METHODS: We conducted a 24-week, placebo-controlled phase 2 trial of intranasal oxytocin therapy in children and adolescents 3 to 17 years of age with autism spectrum disorder. Participants were randomly assigned in a 1:1 ratio, with stratification according to age and verbal fluency, to receive oxytocin or placebo, administered intranasally, with a total target dose of 48 international units daily. The primary outcome was the least-squares mean change from baseline on the Aberrant Behavior Checklist modified Social Withdrawal subscale (ABC-mSW), which includes 13 items (scores range from 0 to 39, with higher scores indicating less social interaction). Secondary outcomes included two additional measures of social function and an abbreviated measure of IQ. RESULTS: Of the 355 children and adolescents who underwent screening, 290 were enrolled. A total of 146 participants were assigned to the oxytocin group and 144 to the placebo group; 139 and 138 participants, respectively, completed both the baseline and at least one postbaseline ABC-mSW assessments and were included in the modified intention-to-treat analyses. The least-squares mean change from baseline in the ABC-mSW score (primary outcome) was −3.7 in the oxytocin group and −3.5 in the placebo group (least-squares mean difference, −0.2; 95% confidence interval, −1.5 to 1.0; P = 0.61). Secondary outcomes generally did not differ between the trial groups. The incidence and severity of adverse events were similar in the two groups. CONCLUSIONS: This placebo-controlled trial of intranasal oxytocin therapy in children and adolescents with autism spectrum disorder showed no significant between-group differences in the least-squares mean change from baseline on measures of social or cognitive functioning over a period of 24 weeks. (Funded by the National Institute of Child Health and Human Development; SOARS-B ClinicalTrials.gov number, NCT01944046.)

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.

Lymphoblastoid cell lines (LCLs) are generated by transforming primary B cells with Epstein–Barr virus (EBV) and are used extensively as model systems in viral oncology, immunology, and human genetics research. In this study, we characterized single-cell transcriptomic profiles of five LCLs and present a simple discrete-time simulation to explore the influence of stochasticity on LCL clonal evolution. Single-cell RNA sequencing (scRNA-seq) revealed substantial phenotypic heterogeneity within and across LCLs with respect to immunoglobulin isotype; virus-modulated host pathways involved in survival, activation, and differentiation; viral replication state; and oxidative stress. This heterogeneity is likely attributable to intrinsic variance in primary B cells and host–pathogen dynamics. Stochastic simulations demonstrate that initial primary cell heterogeneity, random sampling, time in culture, and even mild differences in phenotype-specific fitness can contribute substantially to dynamic diversity in populations of nominally clonal cells.

Introduction: People with type 2 diabetes mellitus (DM) have a large burden of cardiovascular (CV) morbidity and mortality, but the likelihood of these outcomes varies and existing risk calculators do not fully capture risk for individuals. Hypothesis: Circulating metabolites characterizing mitochondrial dysfunction may be novel predictors for CV outcomes. Methods: We performed targeted mass-spectrometry metabolite profiling (45 acylcarnitines, 15 amino acids) on baseline plasma samples from 568 cases (498 with major adverse cardiac events (MACE) and 131 with incident hospitalization for heart failure (hHF)) and 568 matched controls (without events) from the patients assigned to placebo in Trial Evaluating Cardiovascular Outcomes with Sitagliptin (TECOS). Matching was based on history of HF, coronary artery disease, BMI, hemoglobin A1C, creatinine, low-density lipoprotein cholesterol, fasting status and ejection fraction. Principal components analysis (PCA) was used for dimensionality reduction, and conditional logistic regression to determine association of PCA factors with MACE or hHF and for individual metabolites within significant factors (false discovery rate q Results: Of 12 PCA-derived metabolite factors, three were associated significantly with MACE or hHF; these factors were composed of: 1) short-chain dicarboxylacylcarnitines and long chain acylcarnitines (OR 1.50, q=0.03); 2) medium chain acylcarnitines (OR 1.28, q=0.001); 3) C5:1 and one medium-chain dicarboxylacylcarnitine (OR 1.17, q=0.03). Of these three factors, none were significantly associated with the individual components of MACE. Ten individual metabolites, including short- and medium-chain dicarboxylacylcarnitines and medium- and long-chain acylcarnitines, remained significantly associated with MACE (q Conclusions: Metabolites reporting on dysregulated mitochondrial fatty acid oxidation and endoplasmic reticulum stress are elevated in individuals with DM who progress to MACE and/or hHF. These biomarkers may improve CV risk prediction in DM patients and help highlight emerging risk mechanisms.

Lymphoblastoid Cell Lines (LCLs) are generated by transforming primary B cells with Epstein-Barr Virus (EBV) and are used extensively as model systems in viral oncology, immunology, and human genetics research. In this study, we characterized single-cell transcriptomic profiles of five LCLs and present a simple discrete-time simulation to explore the influence of stochasticity on LCL clonal evolution. Single-cell RNA sequencing revealed substantial phenotypic heterogeneity within and across LCLs with respect to immunoglobulin isotype; virus-modulated host pathways involved in survival, proliferation, and differentiation; viral replication state; and oxidative stress. This heterogeneity is likely attributable to intrinsic variance in primary B cells and host-pathogen dynamics. Stochastic simulations demonstrate that initial primary cell heterogeneity, random sampling, time in culture, and even mild differences in phenotype-specific fitness can contribute substantially to dynamic diversity in populations of nominally clonal cells.

Background Greater than half of major adverse cardiovascular events (MACE) occur in individuals with non-obstructive coronary artery disease (CAD) and may be related to the presence of high-risk coronary atherosclerotic plaque (HRP). HRP can be detected by coronary computed tomographic angiography (CTA) and is associated with increased MACE risk. Biomarkers associated with HRP may therefore aid in risk stratification in individuals with chest pain and provide insight into the biology of HRP. Purpose To determine whether nuclear magnetic resonance (NMR)-measured lipoprotein particles are associated with HRP independent of risk factors. Methods This study included 1755 stable symptomatic outpatients enrolled in the PROMISE trial who had coronary CTA performed. Thirty-seven lipoprotein particle parameters were measured in plasma using NMR. Principal components analysis was used to reduce the number of correlated lipoproteins into a smaller number of uncorrelated factors. HRP cases (N=277) were defined as presence of HRP features (positive remodeling, low CT attenuation or napkin-ring sign) with or without obstructive CAD; controls had no HRP and no obstructive CAD (N=1478). Multivariable logistic regression models adjusting for age, sex, diabetes, hypertension, BMI, smoking status and statin use were used to test for association of lipoprotein factors with HRP case/control status; lipoproteins loaded within significant factors (p Results HRP cases were less likely to be female than controls (36.8% vs. 56.6%) and were more likely to have diabetes (23.5% vs 19.6%), but were of similar age (60.1 vs 60.4 years [SD±8]) and with similar statin use (45.2% vs 44.4%). In multivariable models, two lipoprotein factors were associated with HRP: an HDL factor (OR 1.29 [95% CI, 1.10–1.52], p=0.002) and a triglyceride (TG) factor (OR 1.19 [1.03–1.36], p=0.01). Within these two factors, H6P (a large HDL subclass; OR 0.67 [0.54–0.82], p Conclusions In a cohort of low-risk patients from the PROMISE trial, large HDL and small TG particles were associated with CTA-defined HRP independent of risk factors. Large HDL particles were also associated with incident MACE in a separate high-risk cohort. The discordant direction of association of HDL subclasses with HRP and MACE is likely due to underlying HDL biology and requires further study. Acknowledgement/Funding The PROMISE trial was funded by the National Heart, Lung, and Blood Institute (grants R01HL098237, R01HL098236, R01HL98305, and R01HL098235)

This study examined the utility of serum neurofilament light chain (sNfL) and glial fibrillary acidic protein (sGFAP) as biomarkers in primary progressive multiple sclerosis in context with clinical severity, progression, and treatment. Using a single-molecule array (Quanterix), serum protein concentrations were measured from twenty-five participants semiannually for five years. There was no association between levels of either biomarker and disease severity, disease duration, or treatment group. Enrollment sNfL level was not associated with future clinical worsening. Precedent clinical worsening was not associated with last sGFAP measurement. These results suggest a limited role for these biomarkers in primary progressive disease management.