Cardiovascular Metabolomics

Effect of traditional Chinese medicine on metabolism disturbance in ischemic heart diseases

ETHNOPHARMACOLOGICAL RELEVANCE

Ischemic heart diseases (IHD), characterized by metabolic dysregulation, contributes majorly to the global morbidity and mortality. Glucose, lipid and amino acid metabolism are critical energy production for cardiomyocytes, and disturbances of these metabolism lead to the cardiac injury. Traditional Chinese medicine (TCM), widely used for treating IHD, have been demonstrated to effectively and safely regulate the cardiac metabolism reprogramming.

AIM OF THE REVIEW

This study discussed and analyzed the disturbed cardiac metabolism induced by IHD and development of formulas, extracts, single herb, bioactive compounds of TCM ameliorating IHD injury via metabolism regulation, with the aim of providing a basis for the development of clinical application of therapeutic strategies for TCM in IHD.

MATERIALS AND METHODS

With "ischemic heart disease", "myocardial infarction", "myocardial ischemia", "metabolomics", "Chinese medicine", "herb", "extracts" "medicinal plants", "glucose", "lipid metabolism", "amino acid" as the main keywords, PubMed, Web of Science, and other online search engines were used for literature retrieval.

RESULTS

IHD exhibits a close association with metabolism disorders, including but not limited to glycolysis, the TCA cycle, oxidative phosphorylation, branched-chain amino acids, fatty acid β-oxidation, ketone body metabolism, sphingolipid and glycerol-phospholipid metabolism. The therapeutic potential of TCM lies in its ability to regulate these disturbed cardiac metabolisms. Additionally, the active ingredients of TCM have depicted wonderful effects in cardiac metabolism reprogramming in IHD.

CONCLUSION

Drawing from the principles of TCM, we have pinpointed specific herbal remedies for the treatment of IHD, and leveraged advanced metabolomics technologies to uncover the effect of these TCMs on metabolomics alteration. In the future, further clinical experimental studies should be included to explore whether more TCM medicines can play a therapeutic role in IHD by reversing cardiac metabolism disorders; multi-omics would be conducted to explore more pathways and genes targeting such metabolism reprogramming by TCMs, and to seek more TCM therapies for IHD.

Metabolomics Characterization of Disease Markers in Diabetes and Its Associated Pathologies

With the change in lifestyle of people, there has been a considerable increase in diabetes, which brings with it certain follow-up pathological conditions, which lead to a substantial medical burden. Identifying biomarkers that aid in screening, diagnosis, and prognosis of diabetes and its associated pathologies would help better patient management and facilitate a personalized treatment approach for prevention and treatment. With the advancement in techniques and technologies, metabolomics has emerged as an omics approach capable of large-scale high throughput data analysis and identifying and quantifying metabolites that provide an insight into the underlying mechanism of the disease and its progression. Diabetes and metabolomics keywords were searched in correspondence with the assigned keywords, including kidney, cardiovascular diseases and critical illness from PubMed and Scopus, from its inception to Dec 2023. The relevant studies from this search were extracted and included in the study. This review is focused on the biomarkers identified in diabetes, diabetic kidney disease, diabetes-related development of CVD, and its role in critical illness.

The Use of Metabolomes in Risk Stratification of Heart Failure Patients: Protocol for a Scoping Review

BACKGROUND

Heart failure (HF) is a significant health problem that is often associated with major morbidity and mortality. Metabolic abnormalities occur in HF and may be used to identify individuals at risk of developing the condition. Furthermore, these metabolic changes may play a role in the pathogenesis and progression of HF. Despite this knowledge, the utility of metabolic changes in diagnosis, management, prognosis, and therapy for patients with chronic HF has not been systematically reviewed.

OBJECTIVE

This scoping review aims to systematically appraise the literature on metabolic changes in patients with HF, describe the role of these changes in pathogenesis, progression, and care, and identify knowledge gaps to inform future research.

METHODS

This review will be conducted using a strategy based on previous reports, the JBI Manual for Evidence Synthesis, and the Preferred Reporting Items for Systematic Reviews and Meta-Analysis Extension for Scoping Reviews (PRISMA-ScR) guidelines. A comprehensive search of electronic databases (Medline, EBSCOhost, Scopus, and Web of Science) will be conducted using keywords related to HF, myocardial failure, metabolomes, metabonomics, and analytical chemistry techniques. The search will include original peer-reviewed research papers (clinical studies conducted on humans and systematic reviews with or without a meta-analysis) published between January 2010 and September 2023. Studies that include patients with HF younger than 18 years or those not published in English will be excluded. Two authors (UGA and MB) will screen the titles and abstracts independently and perform a full-text screen of the relevant and eligible papers. Relevant data will be extracted and synthesized, and a third author or group will be consulted to resolve discrepancies.

RESULTS

This scoping review will span from January 2010 to September 2023, and the results will be published in a peer-reviewed, open-access journal as a scoping review in 2024. The presentation of the findings will use the PRISMA-ScR flow diagram and descriptive and narrative formats, including tables and graphical displays, to provide a comprehensive overview of the extracted data.

CONCLUSIONS

This review aims to collect and analyze the available evidence on metabolic changes in patients with HF, aiming to enhance our current understanding of this topic. Additionally, this review will identify the most commonly used and suitable sample, analytical method, and specific metabolomes to facilitate standardization, reproducibility of results, and application in the diagnosis, treatment, and risk stratification of patients with HF. Finally, it is hoped that this review's outcomes will inspire further research into the metabolomes of patients with HF in low- and middle-income countries.

TRIAL REGISTRATION

Open Science Framework; https://osf.io/sp6xj.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/53905.

Metabolomic signatures for blood pressure from early to late adolescence: findings from a U.S. cohort

INTRODUCTION

Metabolite signatures for blood pressure (BP) may reveal biomarkers, elucidate pathogenesis, and provide prevention targets for high BP. Knowledge regarding metabolites associated with BP in adolescence remains limited.

OBJECTIVES

Investigate the associations between metabolites and adolescent BP, both cross-sectionally (in early and late adolescence) and prospectively (from early to late adolescence).

METHODS

Participants are from the Project Viva prospective cohort. During the early (median: 12.8 years; N = 556) and late (median: 17.4 years; N = 501) adolescence visits, we conducted untargeted plasma metabolomic profiling and measured systolic (SBP) and diastolic BP (DBP). We used linear regression to identify metabolites cross-sectionally associated with BP at each time point, and to assess prospective associations of changes in metabolite levels from early to late adolescence with late adolescence BP. We used Weighted Gene Correlation Network Analysis and Spearman's partial correlation to identify metabolite clusters associated with BP at each time point.

RESULTS

In the linear models, higher androgenic steroid levels were consistently associated with higher SBP and DBP in early and late adolescence. A cluster of 59 metabolites, mainly composed of androgenic steroids, correlated with higher SBP and DBP in early adolescence. A cluster primarily composed of fatty acid lipids was marginally associated with higher SBP in females in late adolescence. Multiple metabolites, including those in the creatine and purine metabolism sub-pathways, were associated with higher SBP and DBP both cross-sectionally and prospectively.

CONCLUSION

Our results shed light on the potential metabolic processes and pathophysiology underlying high BP in adolescents.

Plasma Metabolome Predicts Aortic Stiffness and Future Risk of Coronary Artery Disease and Mortality After 23 Years of Follow-Up in the General Population

BACKGROUND

Increased aortic stiffness (arteriosclerosis) is associated with early vascular aging independent of age and sex. The underlying mechanisms of early vascular aging remain largely unexplored in the general population. We aimed to investigate the plasma metabolomic profile in aortic stiffness (vascular aging) and associated risk of incident cardiovascular disease and mortality.

METHODS AND RESULTS

We included 6865 individuals from 2 Swedish population-based cohorts. Untargeted plasma metabolomics was performed by liquid-chromatography mass spectrometry. Aortic stiffness was assessed directly by carotid-femoral pulse wave velocity (PWV) and indirectly by augmentation index (AIx@75). A least absolute shrinkage and selection operator (LASSO) regression model was created on plasma metabolites in order to predict aortic stiffness. Associations between metabolite-predicted aortic stiffness and risk of new-onset cardiovascular disease, cardiovascular mortality, and all-cause mortality were calculated. Metabolite-predicted aortic stiffness (PWV and AIx@75) was positively associated particularly with acylcarnitines, dimethylguanidino valeric acid, glutamate, and cystine. The plasma metabolome predicted aortic stiffness (PWV and AIx@75) with good accuracy (R2=0.27 and R2=0.39, respectively). Metabolite-predicted aortic stiffness (PWV and AIx@75) was significantly correlated with age, sex, systolic blood pressure, body mass index, and low-density lipoprotein. After 23 years of follow-up, metabolite-predicted aortic stiffness (PWV and AIx@75) was significantly associated with increased risk of new-onset coronary artery disease, cardiovascular mortality, and all-cause mortality.

CONCLUSIONS

Aortic stiffness is associated particularly with altered metabolism of acylcarnitines, cystine, and dimethylguanidino valeric acid. These metabolic disturbances predict increased risk of new-onset coronary artery disease, cardiovascular mortality, and all-cause mortality after more than 23 years of follow-up in the general population.

l-thyroxine attenuates extracellular Hsp90α-induced vascular endothelial calcification in diabetes mellitus, as revealed by parallel metabolic profiles

BACKGROUND AND AIMS

Diabetic atherosclerotic vascular disease is characterized by extensive vascular calcification. However, an elevated blood glucose level alone does not explain this pathogenesis. We investigated the metabolic markers underlying diabetic atherosclerosis and whether extracellular Hsp90α (eHsp90α) triggers vascular endothelial calcification in this particular metabolic environment.

METHODS

A parallel human/animal model metabolomics approach was used. We analyzed 40 serum samples collected from 24 patients with atherosclerosis and from the STZ-induced ApoE-/- mouse model. A multivariate statistical analysis of the data was performed, and mouse aortic tissue was collected for the assessment of plaque formation. In vitro, the effects of eHsp90α on endothelial cell calcification were assessed by serum analysis, Western blotting and immunoelectron microscopy.

RESULTS

Diabetic ApoE-/- mice showed more severe plaque lesions and calcification damage. Stearamide, oleamide, l-thyroxine, l-homocitrulline and l-citrulline are biomarkers of diabetic ASVD; l-thyroxine was downregulated in both groups, and the thyroid sensitivity index was correlated with serum Hsp90α concentration. In vitro studies showed that eHsp90α increased Runx2 expression in endothelial cells through the LRP1 receptor. l-thyroxine reduced the increase in Runx2 levels caused by eHsp90α and affected the distribution and expression of LRP1 through hydrogen bonding with glutamine at position 1054 in the extracellular segment of LRP1.

CONCLUSIONS

This study provides a mechanistic link between characteristic serum metabolites and diabetic atherosclerosis and thus offers new insight into the role of extracellular Hsp90α in promoting vascular calcification.

Changes in blood metabolomes as potential markers for severity and prognosis in doxorubicin-induced cardiotoxicity: a study in HER2-positive and HER2-negative breast cancer patients

BACKGROUND

We aimed to compare the changes in blood metabolomes and cardiac parameters following doxorubicin treatment in HER2-positive and HER2-negative breast cancer patients. Additionally, the potential roles of changes in blood metabolomes as severity and prognostic markers of doxorubicin-induced cardiotoxicity were determined.

METHODS

HER2-positive (n = 37) and HER2-negative (n = 37) breast cancer patients were enrolled. Cardiac function assessment and blood collection were performed at baseline and 2 weeks after completion of doxorubicin treatment in all patients, as well as at three months after completion of doxorubicin treatment in HER2-negative breast cancer patients. Blood obtained at all three-time points was processed for measuring cardiac injury biomarkers. Blood obtained at baseline and 2 weeks after completion of doxorubicin treatment were also processed for measuring systemic oxidative stress and 85 metabolome levels.

RESULTS

Cardiac injury and systolic dysfunction 2 weeks after completion of doxorubicin treatment were comparable between these two groups of patients. However, only HER2-negative breast cancer patients exhibited increased systemic oxidative stress and cardiac autonomic dysfunction at this time point. Moreover, 33 and 29 blood metabolomes were altered at 2 weeks after completion of doxorubicin treatment in HER2-positive and HER2-negative breast cancer patients, respectively. The changes in most of these metabolomes were correlated with the changes in cardiac parameters, both at 2 weeks and 3 months after completion of doxorubicin treatment.

CONCLUSIONS

The changes in blood metabolomes following doxorubicin treatment were dependent on HER2 status, and these changes might serve as severity and prognostic markers of doxorubicin-induced cardiotoxicity.

TRIAL REGISTRATION

The study was conducted under ethical approval from the Institutional Review Board of the Faculty of Medicine, Chiang Mai University (Registration number: MED-2563-07001; Date: April 28, 2020). The study also complied with the Declaration of Helsinki.

Smoking cessation only partially reverses cardiac metabolic and structural remodeling in mice

AIMS

Active cigarette smoking is a major risk factor for chronic obstructive pulmonary disease that remains elevated after cessation. Skeletal muscle dysfunction has been well documented after smoking, but little is known about cardiac adaptations to cigarette smoking. The underlying cellular and molecular cardiac adaptations, independent of confounding lifestyle factors, and time course of reversibility by smoking cessation remain unclear. We hypothesized that smoking negatively affects cardiac metabolism and induces local inflammation in mice, which do not readily reverse upon 2-week smoking cessation.

METHODS

Mice were exposed to air or cigarette smoke for 14 weeks with or without 1- or 2-week smoke cessation. We measured cardiac mitochondrial respiration by high-resolution respirometry, cardiac mitochondrial density, abundance of mitochondrial supercomplexes by electrophoresis, and capillarization, fibrosis, and macrophage infiltration by immunohistology, and performed cardiac metabolome and lipidome analysis by mass spectrometry.

RESULTS

Mitochondrial protein, supercomplex content, and respiration (all p < 0.03) were lower after smoking, which were largely reversed within 2-week smoking cessation. Metabolome and lipidome analyses revealed alterations in mitochondrial metabolism, a shift from fatty acid to glucose metabolism, which did not revert to control upon smoking cessation. Capillary density was not different after smoking but increased after smoking cessation (p = 0.02). Macrophage infiltration and fibrosis (p < 0.04) were higher after smoking but did not revert to control upon smoking cessation.

CONCLUSIONS

While cigarette-impaired smoking-induced cardiac mitochondrial function was reversed by smoking cessation, the remaining fibrosis and macrophage infiltration may contribute to the increased risk of cardiovascular events after smoking cessation.

Comprehensive Metabolomic Analysis of Human Heart Tissue Enabled by Parallel Metabolite Extraction and High-Resolution Mass Spectrometry

The heart contracts incessantly and requires a constant supply of energy, utilizing numerous metabolic substrates, such as fatty acids, carbohydrates, lipids, and amino acids, to supply its high energy demands. Therefore, a comprehensive analysis of various metabolites is urgently needed for understanding cardiac metabolism; however, complete metabolome analyses remain challenging due to the broad range of metabolite polarities, which makes extraction and detection difficult. Herein, we implemented parallel metabolite extractions and high-resolution mass spectrometry (MS)-based methods to obtain a comprehensive analysis of the human heart metabolome. To capture the diverse range of metabolite polarities, we first performed six parallel liquid-liquid extractions (three monophasic, two biphasic, and one triphasic) of healthy human donor heart tissue. Next, we utilized two complementary MS platforms for metabolite detection: direct-infusion ultrahigh-resolution Fourier-transform ion cyclotron resonance (DI-FTICR) and high-resolution liquid chromatography quadrupole time-of-flight tandem MS (LC-Q-TOF-MS/MS). Using DI-FTICR MS, 9644 metabolic features were detected where 7156 were assigned a molecular formula and 1107 were annotated by accurate mass assignment. Using LC-Q-TOF-MS/MS, 21,428 metabolic features were detected where 285 metabolites were identified based on fragmentation matching against publicly available libraries. Collectively, 1340 heart metabolites were identified in this study, which span a wide range of polarities including polar (benzenoids, carbohydrates, and nucleosides) as well as nonpolar (phosphatidylcholines, acylcarnitines, and fatty acids) compounds. The results from this study will provide critical knowledge regarding the selection of appropriate extraction and MS detection methods for the analysis of the diverse classes of human heart metabolites.

Diet-derived circulating antioxidants and risk of epilepsy: A study combining metabolomics and mendelian randomization

Background

Previous studies offer inconclusive results on the association between diet-derived circulating antioxidants and epilepsy.

Objective

This study aims to assess oxidative stress presence in epilepsy patients' circulation and investigate the causal link between diet-derived circulating antioxidants and epilepsy.

Methods

Untargeted metabolomics analysis was conducted on plasma samples from 62 epileptic patients and 20 healthy individuals to evaluate oxidative stress based on metabolite alterations in epilepsy patients' circulation. Two-sample Mendelian Randomization (MR) analysis examined the causation between diet-derived circulating antioxidants (measured by absolute levels and relative metabolite concentrations) and epilepsy, utilizing the inverse-variance weighted (IVW) method as the primary outcome, with complementary MR analysis methods (MR Egger, weighted median, weighted mode, and simple mode).

Results

Untargeted metabolomics analysis revealed elevated circulating oxidizing metabolites (palmitic acid, oleic acid, linoleic acid, and myristic acid) and reduced reducing metabolites (glutamine) in epilepsy patients, providing robust evidence of oxidative stress. The IVW analysis indicated significantly reduced epilepsy risk (odds ratio: 0.552; 95% confidence interval: 0.335-0.905, P = 0.018) with genetically determined higher absolute circulating β-carotene. However, other diet-derived circulating antioxidants (lycopene, retinol, ascorbic acid, and selenium) and antioxidant metabolites (α-tocopherol, γ-tocopherol, ascorbic acid, and retinol) did not significantly associate with epilepsy risk. Additional MR analysis methods and heterogeneity assessments confirmed the results' robustness.

Conclusion

This study provides compelling evidence of oxidative stress in epilepsy patients' circulation. However, the majority of diet-derived circulating antioxidants (lycopene, retinol, ascorbic acid, vitamin E, and selenium) are unlikely to causally associate with reduced epilepsy risk, except for β-carotene.

Serum metabolite signatures of cardiac function and morphology in individuals from a population-based cohort

BACKGROUND

Changes in serum metabolites in individuals with altered cardiac function and morphology may exhibit information about cardiovascular disease (CVD) pathway dysregulations and potential CVD risk factors. We aimed to explore associations of cardiac function and morphology, evaluated using magnetic resonance imaging (MRI) with a large panel of serum metabolites.

METHODS

Cross-sectional data from CVD-free individuals from the population-based KORA cohort were analyzed. Associations between 3T-MRI-derived left ventricular (LV) function and morphology parameters (e.g., volumes, filling rates, wall thickness) and markers of carotid plaque with metabolite profile clusters and single metabolites as outcomes were assessed by adjusted multinomial logistic regression and linear regression models.

RESULTS

In 360 individuals (mean age 56.3 years; 41.9% female), 146 serum metabolites clustered into three distinct profiles that reflected high-, intermediate- and low-CVD risk. Higher stroke volume (relative risk ratio (RRR): 0.53, 95%-CI [0.37; 0.76], p-value < 0.001) and early diastolic filling rate (RRR: 0.51, 95%-CI [0.37; 0.71], p-value < 0.001) were most strongly protectively associated against the high-risk profile compared to the low-risk profile after adjusting for traditional CVD risk factors. Moreover, imaging markers were associated with 10 metabolites in linear regression. Notably, negative associations of stroke volume and early diastolic filling rate with acylcarnitine C5, and positive association of function parameters with lysophosphatidylcholines, diacylphosphatidylcholines, and acylalkylphosphatidylcholines were observed. Furthermore, there was a negative association of LV wall thickness with alanine, creatinine, and symmetric dimethylarginine. We found no significant associations with carotid plaque.

CONCLUSIONS

Serum metabolite signatures are associated with cardiac function and morphology even in individuals without a clinical indication of CVD.

Cardiac macrophage metabolism in health and disease

Cardiac macrophages are essential mediators of cardiac development, tissue homeostasis, and response to injury. Cell-intrinsic shifts in metabolism and availability of metabolites regulate macrophage function. The human and mouse heart contain a heterogeneous compilation of cardiac macrophages that are derived from at least two distinct lineages. In this review, we detail the unique functional roles and metabolic profiles of tissue-resident and monocyte-derived cardiac macrophages during embryonic development and adult tissue homeostasis and in response to pathologic and physiologic stressors. We discuss the metabolic preferences of each macrophage lineage and how metabolism influences monocyte fate specification. Finally, we highlight the contribution of cardiac macrophages and derived metabolites on cell-cell communication, metabolic health, and disease pathogenesis.

Metabolomic associations of impaired awareness of hypoglycaemia in type 1 diabetes

This study investigates impaired awareness of hypoglycaemia (IAH), a complication of insulin therapy affecting 20-40% of individuals with type 1 diabetes. The exact pathophysiology is unclear, therefore we sought to identify metabolic signatures in IAH to elucidate potential pathophysiological pathways. Plasma samples from 578 individuals of the Dutch type 1 diabetes biomarker cohort, 67 with IAH and 108 without IAH (NAH) were analysed using the targeted metabolomics Biocrates AbsoluteIDQ p180 assay. Eleven metabolites were significantly associated with IAH. Genome-wide association studies of these 11 metabolites identified significant single nucleotide polymorphisms (SNPs) in C22:1-OH and phosphatidylcholine diacyl C36:6. After adjusting for the SNPs, 11 sphingomyelins and phosphatidylcholines were significantly higher in the IAH group in comparison to NAH. These metabolites are important components of the cell membrane and have been implicated to play a role in cell signalling in diabetes. These findings demonstrate the potential role of phosphatidylcholine and sphingomyelins in IAH.

Common data models to streamline metabolomics processing and annotation, and implementation in a Python pipeline

To standardize metabolomics data analysis and facilitate future computational developments, it is essential is have a set of well-defined templates for common data structures. Here we describe a collection of data structures involved in metabolomics data processing and illustrate how they are utilized in a full-featured Python-centric pipeline. We demonstrate the performance of the pipeline, and the details in annotation and quality control using large-scale LC-MS metabolomics and lipidomics data and LC-MS/MS data. Multiple previously published datasets are also reanalyzed to showcase its utility in biological data analysis. This pipeline allows users to streamline data processing, quality control, annotation, and standardization in an efficient and transparent manner. This work fills a major gap in the Python ecosystem for computational metabolomics.

Preoperative serum cortisone levels are associated with cognition in preschool-aged children with tetralogy of Fallot after corrective surgery: new evidence from human populations and mice

BACKGROUND

Tetralogy of Fallot (TOF) is the most common cyanotic congenital heart disease. Children with TOF would be confronted with neurological impairment across their lifetime. Our study aimed to identify the risk factors for cerebral morphology changes and cognition in postoperative preschool-aged children with TOF.

METHODS

We used mass spectrometry (MS) technology to assess the levels of serum metabolites, Wechsler preschool and primary scale of intelligence-Fourth edition (WPPSI-IV) index scores to evaluate neurodevelopmental levels and multimodal magnetic resonance imaging (MRI) to detect cortical morphological changes.

RESULTS

Multiple linear regression showed that preoperative levels of serum cortisone were positively correlated with the gyrification index of the left inferior parietal gyrus in children with TOF and negatively related to their lower visual spaces index and nonverbal index. Meanwhile, preoperative SpO2 was negatively correlated with levels of serum cortisone after adjusting for all covariates. Furthermore, after intervening levels of cortisone in chronic hypoxic model mice, total brain volumes were reduced at both postnatal (P) 11.5 and P30 days.

CONCLUSIONS

Our results suggest that preoperative serum cortisone levels could be used as a biomarker of neurodevelopmental impairment in children with TOF. Our study findings emphasized that preoperative levels of cortisone could influence cerebral development and cognition abilities in children with TOF.

Understanding aconite's anti-fibrotic effects in cardiac fibrosis

BACKGROUND

The prevalence of cardiac fibrosis, intricately linked to various cardiovascular diseases, continues to rise. Aconite, a traditional Chinese herb renowned for its cardiovascular benefits, holds promise in treating heart ailments. However, the mechanisms underlying its anti-fibrotic effects, particularly in cardiac fibrosis, remain elusive.

HYPOTHESIS/PURPOSE

This study aims to shed light on aconite's potential as an anti-fibrotic agent and elucidate its mechanisms in a rat model of isoproterenol (ISO)-induced cardiac fibrosis.

METHODS

By inducing cardiac fibrosis through ISO injection, the study investigates the role of decoction of white aconite (DWA) in mitigating fibrotic processes. Techniques including metabolomics, RT-qPCR, western blot, and immunofluorescence were employed to unveil the molecular changes induced by DWA.

RESULTS

DWA exhibited a remarkable reduction in echocardiographic parameters, cardiac weight increase, myocardial infarction extent, inflammatory cell infiltration, collagen deposition in heart tissue, and serum CK-MB, cTnT, cTnI levels post ISO injection. Metabolomic analysis unveiled DWA's modulation of 27 metabolites, especially in galactose metabolism, addressing metabolic disturbances in cardiac fibrosis. Additionally, DWA suppressed mRNA expression of fibrosis markers (Collagen I, CTGF, TGF-β), inhibited protein levels of MMP-9, α-SMA, and Galectin-3, while elevating TIMP1 expression.

CONCLUSION

DWA demonstrated potent anti-fibrotic effects by curbing collagen deposition and alleviating metabolic disruptions in cardiac fibrosis via the galactose metabolism pathway, possibly mediated by the Gal-3/TGF-β/Smad signaling pathway.

Dengzhanshengmai capsule alleviates heart failure and concomitantly decreases phenylacetylglutamine level, interacting with the intestinal microflora in rats

Heart failure (HF) is an advanced stage of most heart diseases. Some studies reported that Dengzhanshengmai (DZSM) capsule may improve HF, but its mechanisms are unclear. This study attempts to determine the function of DZSM in treating HF and investigates its potential mechanism. We demonstrated that DZSM can considerably reduce systemic inflammation, improve intestinal barrier functions and enhance cardiac functions in HF rats. Further investigations displayed that the beneficial effects of DZSM were related to the reduction of gut microbiota metabolite phenylacetylglutamine (PAGln) levels in serum and heart tissue. In addition, we demonstrated that PAGln can exacerbate the severity of HF in rats, and the serum PAGln levels in HF patients were higher than in healthy subjects. Moreover, by using microbial sequencing, we found that DZSM could alter the composition and function of the intestinal microbiota in HF rats, including decreased relative abundance of Turicibacter and Turicibacter_sp.TS3, and regulated the gene expression of PAGln synthesis-related enzymes. Therefore, our findings have contributed novel perspectives on the involvement of DZSM in treating HF, specifically in its regulation of intestinal flora and associated detrimental metabolites. Furthermore, our results have offered empirical evidence supporting the utilization of DZSM as a therapeutic approach for HF.

Cardiogenic Shock Integrated PHenotyping for Event Reduction: A Pilot Metabolomics Analysis

Cardiogenic shock (CS) portends a dismal prognosis if hypoperfusion triggers uncontrolled inflammatory and metabolic derangements. We sought to investigate metabolomic profiles and temporal changes in IL6, Ang-2, and markers of glycocalyx perturbation from admission to discharge in eighteen patients with heart failure complicated by CS (HF-CS). Biological samples were collected from 18 consecutive HF-CS patients at admission (T0), 48 h after admission (T1), and at discharge (T2). ELISA analytical techniques and targeted metabolomics were performed Seven patients (44%) died at in-hospital follow-up. Among the survivors, IL-6 and kynurenine were significantly reduced at discharge compared to baseline. Conversely, the amino acids arginine, threonine, glycine, lysine, and asparagine; the biogenic amine putrescine; multiple sphingolipids; and glycerophospholipids were significantly increased. Patients with HF-CS have a metabolomic fingerprint that might allow for tailored treatment strategies for the patients' recovery or stabilization.

Interaction between a Sulfated Polysaccharide from Sea Cucumber and Gut Microbiota Influences the Fat Metabolism in Rats

Due to its significant physiological effects, a sulfated polysaccharide has been considered an important nutrient of sea cucumber, but its metabolism in vivo is still unclear. The present study investigated the metabolism of a sea cucumber sulfated polysaccharide (SCSP) in rats and its influence on the metabolite profiles. The quantification by HPLC-MS/MS revealed that the blood level of SCSP achieved a maximum of 54.0 ± 4.8 μg/mL at 2 h after gavage, almost no SCSP was excreted through urine, and 55.4 ± 29.8% of SCSP was eliminated through feces within 24 h. These results prove the utilization of SCSP by gut microbiota, and a further microbiota sequencing analysis indicated that the SCSP utilization in the gut was positively correlated with Muribaculaceae and Clostridia_UCG-014. In addition, the non-targeted metabolomic analysis demonstrated the significant effects of SCSP administration on the metabolite profiles of blood, urine, and feces. It is worth noting that the SCSP supplement decreased palmitic acid, stearic acid, and oleic acid in blood and urine while increasing stearic acid, linoleic acid, and γ-linolenic acid in feces, suggesting the inhibition of fat absorption and the enhancement of fat excretion by SCSP, respectively. The present study shed light on the metabolism in vivo and the influence on the fat metabolism of SCSP.

Blood-Derived Lipid and Metabolite Biomarkers in Cardiovascular Research from Clinical Studies: A Recent Update

The primary prevention, early detection, and treatment of cardiovascular disease (CVD) have been long-standing scientific research goals worldwide. In the past decades, traditional blood lipid profiles have been routinely used in clinical practice to estimate the risk of CVDs such as atherosclerotic cardiovascular disease (ASCVD) and as treatment targets for the primary prevention of adverse cardiac events. These blood lipid panel tests often fail to fully predict all CVD risks and thus need to be improved. A comprehensive analysis of molecular species of lipids and metabolites (defined as lipidomics and metabolomics, respectively) can provide molecular insights into the pathophysiology of the disease and could serve as diagnostic and prognostic indicators of disease. Mass spectrometry (MS) and nuclear magnetic resonance (NMR)-based lipidomics and metabolomics analysis have been increasingly used to study the metabolic changes that occur during CVD pathogenesis. In this review, we provide an overview of various MS-based platforms and approaches that are commonly used in lipidomics and metabolomics workflows. This review summarizes the lipids and metabolites in human plasma/serum that have recently (from 2018 to December 2022) been identified as promising CVD biomarkers. In addition, this review describes the potential pathophysiological mechanisms associated with candidate CVD biomarkers. Future studies focused on these potential biomarkers and pathways will provide mechanistic clues of CVD pathogenesis and thus help with the risk assessment, diagnosis, and treatment of CVD.

Integration of metabolomics and network pharmacology to reveal the protective mechanism underlying Wogonoside in acute myocardial ischemia rats

ETHNOPHARMACOLOGICAL RELEVANCE

In traditional medicine, both Scutellaria baicalensis Georgi (SBG) and the traditional formulas composed of it have been used to treat a wide range of diseases, including cancer and cardiovascular. Wogonoside (Wog) is the biologically active flavonoid compound extracted from the root of SBG, with potential cardiovascular protective effects. However, the mechanisms underlying the protective effect of Wog on acute myocardial ischemia (AMI) have not yet been clearly elucidated.

AIM OF THE STUDY

To explore the protective mechanism of Wog on AMI rats by comprehensively integrating traditional pharmacodynamics, metabolomics, and network pharmacology.

METHODS

The rat was pretreatment with Wog at a dose of 20 mg/kg/d and 40 mg/kg/d once daily for 10 days and then ligated the left anterior descending coronary artery of rats to establish the AMI rat model. Electrocardiogram (ECG), cardiac enzyme levels, heart weight index (HWI), Triphenyltetrazolium chloride (TTC) staining, and histopathological analyses were adopted to evaluate the protective effect of Wog on AMI rats. Moreover, a serum metabolomic-based UHPLC-Q-Orbitrap MS approach was performed to find metabolic biomarkers and metabolic pathways, and network pharmacology analysis was applied to predict targets and pathways of Wog in treating AMI. Then, the network pharmacology and metabolomic results were integrated to elucidate the mechanism of Wog in treating AMI. Finally, RT- PCR was used to detect the mRNA expression levels of PTGS1, PTGS2, ALOX5, and ALOX15 to validate the result of integrated metabolomics and network analysis.

RESULTS

Pharmacodynamic studies suggest that Wog could effectively prevent the ST-segment of electrocardiogram elevation, reduce the myocardial infarct size, heart weight index, and cardiac enzyme levels, and alleviate cardiac histological damage in AMI rats. Metabolomics analysis showed that the disturbances of metabolic profile in AMI rats were partly corrected by Wog and the cardio-protection effects on AMI rats involved 32 differential metabolic biomarkers and 4 metabolic pathways. In addition, the integrated analysis of network pharmacology and metabolomics showed that 7 metabolic biomarkers, 6 targets, and 6 crucial pathways were the main mechanism for the therapeutic application of Wog for AMI. Moreover, the results of RT-PCR showed that PTGS1, PTGS2, ALOX5, and ALOX15 mRNA expression levels were reduced after treatment with Wog.

CONCLUSION

Wog exerts cardio-protection effects on AMI rats via the regulation of multiple metabolic biomarkers, multiple targets, and multiple pathways, our current study will provide strong scientific evidence supporting the therapeutic application of Wog for AMI.

Effect of genetically determined BCAA levels on cardiovascular diseases and their risk factors: A Mendelian randomization study

BACKGROUND AND AIMS

Observational studies have demonstrated that serum branched-chain amino acids (BCAAs) are associated with the risk of various cardiovascular diseases (CVDs) and their risk factors. However, the causal effect is unclear. The aim of this study was to investigate the effect of genetically determined BCAA levels on CVDs and their risk factors using Mendelian randomization (MR).

METHODS AND RESULTS

We performed univariable and multivariable MR analyses using summary-level data from multiple GWASs and the FinnGen consortium to investigate the association between BCAA levels and the risk of CVDs (myocardial infarction, ischemic stroke, and intracerebral hemorrhage) and their risk factors (atrial fibrillation, hypertension, heart failure, and valvular heart disease). We used the random-effects IVW approach as the primary statistical method and incorporated MR estimates from different data sources using the fixed-effects model. We found genetically determined total and individual BCAA levels and a high risk of hypertension. However, there is no evidence of a causal relationship between BCAA levels and 3 cardiovascular diseases and other their risk factors. The odds of hypertension increased per 1-SD increase in BCAA levels (OR = 1.02 95% CI: 1.01, 1.04; P = 0.005), valine (OR = 1.02 95% CI: 1.01, 1.03; P<0.0001), leucine (OR = 1.02 95% CI: 1.01, 1.04; P＜0.01), and isoleucine (OR = 1.02 95% CI: 1.01, 1.03; P < 0.0001). This result was also significant in the multivariable MR.

CONCLUSIONS

This MR study suggests that total and individual BCAA levels could be associated with a high risk of hypertension.

Characterizing substrate utilization during the fasted state using plasma high-resolution metabolomics

OBJECTIVES

High-resolution metabolomics enables global assessment of metabolites and molecular pathways underlying physiologic processes, including substrate utilization during the fasted state. The clinical index for substrate utilization, respiratory exchange ratio (RER), is measured via indirect calorimetry. The aim of this pilot study was to use metabolomics to identify metabolic pathways and plasma metabolites associated with substrate utilization in healthy, fasted adults.

METHODS

This cross-sectional study included 33 adults (mean age 27.7 ± 4.9 y, mean body mass index 24.8 ± 4 kg/m2). Participants underwent indirect calorimetry to determine resting RER after an overnight fast. Untargeted metabolomics was performed on fasted plasma samples using dual-column liquid chromatography and ultra-high-resolution mass spectrometry. Linear regression and pathway enrichment analyses identified pathways and metabolites associated with substrate utilization measured with indirect calorimetry.

RESULTS

RER was significantly associated with 1389 metabolites enriched within 13 metabolic pathways (P < 0.05). Lipid-related findings included general pathways, such as fatty acid activation, and specific pathways, such as C21-steroid hormone biosynthesis and metabolism, butyrate metabolism, and carnitine shuttle. Amino acid pathways included those central to metabolism, such as glucogenic amino acids, and pathways needed to maintain reduction-oxidation reactions, such as methionine and cysteine metabolism. Galactose and pyrimidine metabolism were also associated with RER (all P < 0.05).

CONCLUSIONS

The fasting plasma metabolome reflects the diverse macronutrient pathways involved in carbohydrate, amino acid, and lipid metabolism during the fasted state in healthy adults. Future studies should consider the utility of metabolomics to profile individual nutrient requirements and compare findings reported here to clinical populations.

Metabolomics signature of cardiovascular disease in patients with diabetes, a narrative review

Objectives

The exact underlying mechanism of developing diabetes-related cardiovascular disease (CVD) among patients with type 2 diabetes (T2D) is not clear. Metabolomics can provide a platform enabling the prediction, diagnosis, and understanding of the risk of CVD in patients with diabetes mellitus. The aim of this review is to summarize the available evidence on the relationship between metabolomics and cardiovascular diseases in patients with diabetes.

Methods

The literature was searched to find out studies that have investigated the relationship between the alteration of specific metabolites and cardiovascular diseases in patients with diabetes.

Results

Evidence proposed that changes in the metabolism of certain amino acids, lipids, and carbohydrates, independent of traditional CVD risk factors, are associated with increased CVD risk.

Conclusions

Metabolomics can provide a platform to enable the prediction, diagnosis, and understanding of the risk of CVD in patients with diabetes mellitus. The association of the alteration in specific metabolites with CVD may be considered in the investigations for the development of new therapeutic targets for the prevention of CVD in patients with diabetes mellitus.

Host-microbe tryptophan partitioning in cardiovascular diseases

The functional interdependencies between the molecular components of a biological process demand for a network medicine platform that integrates systems biology and network science, to explore the interactions among biological components in health and disease. Access to large-scale omics datasets (genomics, transcriptomics, proteomics, metabolomics, metagenomics, phenomics, etc.) has significantly advanced our opportunity along this direction. Studies utilizing these techniques have begun to provide us with a deeper understanding of how the interaction between the intestinal microbes and their host affects the cardiovascular system in health and disease. Within the framework of a multiomics network approach, we highlight here how tryptophan metabolism may orchestrate the host-microbes interaction in cardiovascular diseases and the implications for precision medicine and therapeutics, including nutritional interventions.

Next Generation, Modifiable Cardiometabolic Biomarkers: Mitochondrial Adaptation and Metabolic Resilience: A Scientific Statement From the American Heart Association

Cardiometabolic risk is increasing in prevalence across the life span with disproportionate ramifications for youth at socioeconomic disadvantage. Established risk factors and associated disease progression are harder to reverse as they become entrenched over time; if current trends are unchecked, the consequences for individual and societal wellness will become untenable. Interrelated root causes of ectopic adiposity and insulin resistance are understood but identified late in the trajectory of systemic metabolic dysregulation when traditional cardiometabolic risk factors cross current diagnostic thresholds of disease. Thus, children at cardiometabolic risk are often exposed to suboptimal metabolism over years before they present with clinical symptoms, at which point life-long reliance on pharmacotherapy may only mitigate but not reverse the risk. Leading-edge indicators are needed to detect the earliest departure from healthy metabolism, so that targeted, primordial, and primary prevention of cardiometabolic risk is possible. Better understanding of biomarkers that reflect the earliest transitions to dysmetabolism, beginning in utero, ideally biomarkers that are also mechanistic/causal and modifiable, is critically needed. This scientific statement explores emerging biomarkers of cardiometabolic risk across rapidly evolving and interrelated "omic" fields of research (the epigenome, microbiome, metabolome, lipidome, and inflammasome). Connections in each domain to mitochondrial function are identified that may mediate the favorable responses of each of the omic biomarkers featured to a heart-healthy lifestyle, notably to nutritional interventions. Fuller implementation of evidence-based nutrition must address environmental and socioeconomic disparities that can either facilitate or impede response to therapy.

The role of HIF-1α/HO-1 pathway in hippocampal neuronal ferroptosis in epilepsy

Epilepsy, a common central nervous system disorder, remains an enigma in pathogenesis. Emerging consensus designates hippocampal neuronal injury as a cornerstone for epileptogenic foci, pivotal in epileptic genesis and progression. Ferroptosis, a regulated cell death modality hinging on iron, catalyzes lipid reactive oxygen species formation through iron and membrane polyunsaturated fatty acid interplay, culminating in oxidative cell death. This research investigates the role of hypoxia-inducible factor (HIF)-1α/heme oxygenase (HO)-1 in hippocampal neuron ferroptosis during epilepsy. Untargeted metabolomics exposes metabolite discrepancies between epilepsy patients and healthy individuals, unveiling escalated oxidative stress, heightened bilirubin, and augmented iron metabolism in epileptic blood. Enrichment analyses unveil active HIF-1 pathway in epileptic pathogenesis, reinforced by HIF-1α signaling perturbations in DisGeNET database. PTZ-kindled mice model confirms increased ferroptotic markers, oxidative stress, HIF-1α, and HO-1 in epilepsy. Study implicates HIF-1α/HO-1 potentially regulates hippocampal neuronal ferroptosis, iron metabolism, and oxidative stress, thereby promoting the propagation of epilepsy.

Metabolomics and mitochondrial dysfunction in cardiometabolic disease

Circulating metabolites are indicators of systemic metabolic dysfunction and can be detected through contemporary techniques in metabolomics. These metabolites are involved in numerous mitochondrial metabolic processes including glycolysis, fatty acid β-oxidation, and amino acid catabolism, and changes in the abundance of these metabolites is implicated in the pathogenesis of cardiometabolic diseases (CMDs). Epigenetic regulation and direct metabolite-protein interactions modulate metabolism, both within cells and in the circulation. Dysfunction of multiple mitochondrial components stemming from mitochondrial DNA mutations are implicated in disease pathogenesis. This review will summarize the current state of knowledge regarding: i) the interactions between metabolites found within the mitochondrial environment during CMDs, ii) various metabolites' effects on cellular and systemic function, iii) how harnessing the power of metabolomic analyses represents the next frontier of precision medicine, and iv) how these concepts integrate to expand the clinical potential for translational cardiometabolic medicine.

Cardiovascular Disease and Alzheimer's Disease: The Heart-Brain Axis

Cardiovascular disease (CVD) remains one of the leading causes of morbidity and mortality in aging adults across the United States. Prior studies indicate that the presence of atherosclerosis, the pathogenic basis of CVD, is linked with dementias. Alzheimer's disease (AD) and AD-related dementias are a major public health challenge in the United States. Recent studies indicate that ≈3.7 million Americans ≥65 years of age had clinical AD in 2017, with projected increases to 9.3 million by 2060. Treatment options for AD remain limited. Development of disease-modifying therapies are challenging due, in part, to the long preclinical window of AD. The preclinical incubation period of AD starts in midlife, providing a critical window for identification and optimization of AD risk factors. Studies link AD with CVD risk factors such as hypertension, inflammation, and dyslipidemia. Both AD and CVD are progressive diseases with decades-long development periods. CVD can clinically manifest several years earlier than AD, making CVD and its risk factors a potential predictor of future AD. The current review focuses on the state of literature on molecular and metabolic pathways modulating the heart-brain axis underlying the potential association of midlife CVD risk factors and their effect on AD and related dementias. Further, we explore potential CVD/dementia preventive strategies during the window of opportunity in midlife and the future of research in the field in the multiomics and novel biomarker use era.

Inhibition of OAT1/3 and CMPF uptake attenuates myocardial ischemia-induced chronic heart failure via decreasing fatty acid oxidation and the therapeutic effects of ruscogenin

Chronic heart failure (CHF) as a long-term disease is highly prevalent in elder people worldwide. Early diagnosis and treatments are crucial for preventing the development of CHF. Herein, we aimed to identify novel diagnostic biomarker, therapeutic target and drug for CHF. Untargeted metabolomic analysis has been used to characterize the different metabolomic profile between CHF patients and healthy people. Meanwhile, the targeted metabolomic study demonstrated the elevation of 3-carboxy-4-methyl-5-propyl-2-furanpropanoic acid (CMPF) in the serum of CHF patients and coronary artery ligation-induced CHF mice. Subsequently, we firstly observed that elevation of CMPF impaired cardiac function and aggravated myocardial injury by enhancing fatty acid oxidation (FAO). Interestingly, inhibition of responsible transporters organic anion transporter 1/3 (OAT1/3) has been found to decrease the CMPF level, and suppress FAO-related key protein expressions including peroxisome proliferator-activated receptor alpha, peroxisome proliferative activated receptor-α, carnitine palmitoyl transferase 1, and malonyl CoA decarboxylase in coronary artery ligation-induced CHF mice. Meanwhile, the inhibitor of OAT1/3 presented an excellent improvement in cardiac function and histological injury. Based on the above findings, molecular docking was adopted to screen the potential therapeutic drug targeting OAT1/3, and ruscogenin (RUS) exhibited a great binding affinity with OAT1 and OAT3. Next, it was verified that RUS could remarkedly decrease the expression of OAT1/3 and CMPF levels in heart tissue of CHF mice, as well as suppress the expression of FAO-related proteins. What's more, RUS can effectively improve cardiac function, myocardial fibrosis and morphological damage. Collectively, this study provided a potential metabolic marker CMPF and novel target OAT1/3 for CHF, which were demonstrated to be involved in FAO. And RUS was identified as a potential anti-FAO drug for CHF by regulating OAT1/3.

Voltage-dependent anion channel 1 (VDAC1) overexpression alleviates cardiac fibroblast activation in cardiac fibrosis via regulating fatty acid metabolism

Cardiac fibrosis is characterized by the excessive deposition of extracellular matrix in the myocardium with cardiac fibroblast activation, leading to chronic cardiac remodeling and dysfunction. However, little is known about metabolic alterations in fibroblasts during cardiac fibrosis, and there is a lack of pharmaceutical treatments that target metabolic dysregulation. Here, we provided evidence that fatty acid β-oxidation (FAO) dysregulation contributes to fibroblast activation and cardiac fibrosis. With transcriptome, metabolome, and functional assays, we demonstrated that FAO was downregulated during fibroblast activation and cardiac fibrosis, and that perturbation of FAO reversely affected the fibroblast-to-myofibroblast transition. The decrease in FAO may be attributed to reduced long-chain fatty acid (LCFA) uptake. Voltage-dependent anion channel 1 (VDAC1), the main gatekeeper of the outer mitochondrial membrane (OMM), serves as the transporter of LCFA into the mitochondria for further utilization and has been shown to be decreased in myofibroblasts. In vitro, the addition of exogenous VDAC1 was shown to ameliorate cardiac fibroblast activation initiated by transforming growth factor beta 1 (TGF-β1) stimuli, and silencing of VDAC1 displayed the opposite effect. A mechanistic study revealed that VDAC1 exerts a protective effect by regulating LCFA uptake into the mitochondria, which is impaired by an inhibitor of carnitine palmitoyltransferase 1A. In vivo, AAV9-mediated overexpression of VDAC1 in myofibroblasts significantly alleviated transverse aortic constriction (TAC)-induced cardiac fibrosis and rescued cardiac function in mice. Finally, we treated mice with the VDAC1-derived R-Tf-D-LP4 peptide, and the results showed that R-Tf-D-LP4 prevented TAC-induced cardiac fibrosis and dysfunction in mice. In conclusion, this study provides evidence that VDAC1 maintains FAO metabolism in cardiac fibroblasts to repress fibroblast activation and cardiac fibrosis and suggests that the VDAC1 peptide is a promising drug for rescuing fibroblast metabolism and repressing cardiac fibrosis.

High-Fat Diet Alters Acylcarnitine Metabolism of the Retina and Retinal Pigment Epithelium/Choroidal Tissues in Laser-Induced Choroidal Neovascularization Rat Models

SCOPE

Choroidal neovascularization (CNV) is age-related macular degeneration's (AMD) main pathological change. High-fat diet (HFD) is associated with a form of CNV; however, the specific mechanism is unclear. Mitochondrial dysfunction, characterized by abnormal acylcarnitine, occurs during metabolic screening of serum or other body tissues in AMD. This study investigates HFD's role in retinal and retinal pigment epithelium (RPE)/choroidal acylcarnitine metabolism in CNV formation.

METHODS AND RESULTS

Chow diet and HFD-BN rats are laser-treated to induce CNV. Acylcarnitine species are quantitatively characterized by ultrahigh-performance liquid chromatography-tandem mass spectrometry. Optical coherence tomography and fundus fluorescein angiography evaluate CNV severity. HFD promotes weight gain, dyslipidemia, and CNV formation. In CNV rats, few medium-chain fatty acids (MCFAs) acylcarnitine in the RPE/choroid are initially affected. When an HFD is administered to these, even MCFA acylcarnitine in the RPE/choroid is found to decline. However, in the retina, odd acylcarnitines are increased, revealing "an opposite" change within the RPE/choroid, accompanied by influencing glycolytic key enzymes. The HFD+CNV group incorporated fewer long-chain acylcarnitines, like C18:2, into the retina than controls.

CONCLUSIONS

HFD hastens choroidal neovascularization. The study comprehensively documented acylcarnitine profiles in a CNV rat model. Acylcarnitine's odd-even and carbon-chain length properties may guide future therapeutics.

Comprehensive Metabolomic Analysis of Human Heart Tissue Enabled by Parallel Metabolite Extraction and High-Resolution Mass Spectrometry

The heart contracts incessantly and requires a constant supply of energy, utilizing numerous metabolic substrates such as fatty acids, carbohydrates, lipids, and amino acids to supply its high energy demands. Therefore, a comprehensive analysis of various metabolites is urgently needed for understanding cardiac metabolism; however, complete metabolome analyses remain challenging due to the broad range of metabolite polarities which makes extraction and detection difficult. Herein, we implemented parallel metabolite extractions and high-resolution mass spectrometry (MS)-based methods to obtain a comprehensive analysis of the human heart metabolome. To capture the diverse range of metabolite polarities, we first performed six parallel liquid-liquid extractions (three monophasic, two biphasic, and one triphasic extractions) of healthy human donor heart tissue. Next, we utilized two complementary MS platforms for metabolite detection - direct-infusion ultrahigh-resolution Fourier-transform ion cyclotron resonance (DI-FTICR) and high-resolution liquid chromatography quadrupole time-of-flight tandem MS (LC-Q-TOF MS/MS). Using DI-FTICR MS, 9,521 metabolic features were detected where 7,699 were assigned a chemical formula and 1,756 were assigned an annotated by accurate mass assignment. Using LC-Q-TOF MS/MS, 21,428 metabolic features were detected where 626 metabolites were identified based on fragmentation matching against publicly available libraries. Collectively, 2276 heart metabolites were identified in this study which span a wide range of polarities including polar (benzenoids, alkaloids and derivatives and nucleosides) as well as non-polar (phosphatidylcholines, acylcarnitines, and fatty acids) compounds. The results of this study will provide critical knowledge regarding the selection of appropriate extraction and MS detection methods for the analysis of the diverse classes of human heart metabolites.

Combining serum metabolomic profiles with traditional risk factors improves 10-year cardiovascular risk prediction in people with type 2 diabetes

AIMS

To identify a group of metabolites associated with incident cardiovascular disease (CVD) in people with type 2 diabetes and assess its predictive performance over-and-above a current CVD risk score (QRISK3).

METHODS AND RESULTS

A panel of 228 serum metabolites was measured at baseline in 1066 individuals with type 2 diabetes (Edinburgh Type 2 Diabetes Study) who were then followed up for CVD over the subsequent 10 years. We applied 100 repeats of Cox least absolute shrinkage and selection operator to select metabolites with frequency >90% as components for a metabolites-based risk score (MRS). The predictive performance of the MRS was assessed in relation to a reference model that was based on QRISK3 plus prevalent CVD and statin use at baseline. Of 1021 available individuals, 255 (25.0%) developed CVD (median follow-up: 10.6 years). Twelve metabolites relating to fluid balance, ketone bodies, amino acids, fatty acids, glycolysis, and lipoproteins were selected to construct the MRS that showed positive association with 10-year cardiovascular risk following adjustment for traditional risk factors [hazard ratio (HR) 2.67; 95% confidence interval (CI) 1.96, 3.64]. The c-statistic was 0.709 (95%CI 0.679, 0.739) for the reference model alone, increasing slightly to 0.728 (95%CI 0.700, 0.757) following addition of the MRS. Compared with the reference model, the net reclassification index and integrated discrimination index for the reference model plus the MRS were 0.362 (95%CI 0.179, 0.506) and 0.041 (95%CI 0.020, 0.071), respectively.

CONCLUSION

Metabolomics data might improve predictive performance of current CVD risk scores based on traditional risk factors in people with type 2 diabetes. External validation is warranted to assess the generalizability of improved CVD risk prediction using the MRS.

Metabolomic profiling of a neurodegenerative retina following optic nerve transection

The degeneration of retinal ganglion cells (RGCs) often causes irreversible vision impairment. Prevention of RGC degeneration can prevent or delay the deterioration of visual function. The present study aimed to investigate retinal metabolic profiles following optic nerve transection (ONT) injury and identify the potential metabolic targets for the prevention of RGC degeneration. Retinal samples were dissected from ONT group and non‑ONT group. The untargeted metabolomics were carried out using liquid chromatography‑tandem mass spectrometry. The involved pathways and biomarkers were analyzed using Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis and MetaboAnalyst 5.0. In the ONT group, 689 disparate metabolites were detected, including lipids and lipid‑like molecules. A total of 122 metabolites were successfully annotated and enriched in 50 KEGG pathways. Among them, 'sphingolipid metabolism' and 'primary bile acid biosynthesis' were identified involved in RGC degeneration. A total of five metabolites were selected as the candidate biomarkers for detecting RGC degeneration with an AUC value of 1. The present study revealed that lipid‑related metabolism was involved in the pathogenesis of retinal neurodegeneration. Taurine, taurochenodesoxycholic acid, taurocholic acid (TCA), sphingosine, and galabiosylceramide are shown as the promising biomarkers for the diagnosis of RGC degeneration.

Comprehensive transcriptomics and metabolomics analyses reveal that hyperhomocysteinemia is a high risk factor for coronary artery disease in a chinese obese population aged 40-65: a prospective cross-sectional study

BACKGROUND

Clinical observations suggest a complex relationship between obesity and coronary artery disease (CAD). This study aimed to characterize the intermediate metabolism phenotypes among obese patients with CAD and without CAD.

METHODS

Sixty-two participants who consecutively underwent coronary angiography were enrolled in the discovery cohort. Transcriptional and untargeted metabolomics analyses were carried out to screen for key molecular changes between obese patients with CAD (CAD obese), without CAD (Non-CAD obese), and Non-CAD leans. A targeted GC-MS metabolomics approach was used to further identify differentially expressed metabolites in the validation cohorts. Regression and receiver operator curve analysis were performed to validate the risk model.

RESULTS

We found common aberrantly expressed pathways both at the transcriptional and metabolomics levels. These pathways included cysteine and methionine metabolism and arginine and proline metabolism. Untargeted metabolomics revealed that S-adenosylhomocysteine (SAH), 3-hydroxybenzoic acid, 2-hydroxyhippuric acid, nicotinuric acid, and 2-arachidonoyl glycerol were significantly elevated in the CAD obese group compared to the other two groups. In the validation study, targeted cysteine and methionine metabolomics analyses showed that homocysteine (Hcy), SAH, and choline were significantly increased in the CAD obese group compared with the Non-CAD obese group, while betaine, 5-methylpropanedioic acid, S-adenosylmethionine, 4-PA, and vitamin B2 (VB2) showed no significant differences. Multivariate analyses showed that Hcy was an independent predictor of obesity with CAD (hazard ratio 1.7; 95%CI 1.2-2.6). The area under the curve based on the Hcy metabolomic (HCY-Mtb) index was 0.819, and up to 0.877 for the HCY-Mtb.index plus clinical variables.

CONCLUSION

This is the first study to propose that obesity with hyperhomocysteinemia is a useful intermediate metabolism phenotype that could be used to identify obese patients at high risk for developing CAD.

Metabolomic analysis reveals the metabolic disturbance in aortic dissection: Subtype difference and accurate diagnosis

BACKGROUND AND AIMS

Aortic dissection (AD), a severe clinical emergency with high mortality, is easily misdiagnosed as are other cardiovascular diseases. This study aimed at discovering plasma metabolic markers with the potential to diagnose AD and clarifying the metabolic differences between two subtypes of AD.

METHODS AND RESULTS

To facilitate the diagnosis of AD, we investigated the plasma metabolic profile by metabolomic approach. A total 482 human subjects were enrolled in the study: 80 patients with AD (50 with Stanford type A and 30 with Stanford type B), 198 coronary artery disease (CAD) patients, and 204 healthy individuals. Plasma samples were submitted to targeted metabolomic analysis. The partial least-squares discriminant analysis models were constructed to illustrate clear discrimination of AD patients with CAD patients and healthy control. Subsequently, the metabolites that were clinically relevant to the disturbances in AD were identified. Twenty metabolites induced the separation of AD patients and healthy control, 9 of which caused the separation of CAD patients and healthy control. There are 11 metabolites specifically down-regulated in AD group. Subgroup analysis showed that the levels of glycerol and uridine were dramatically lower in the plasma of patients with Stanford type A AD than those in the healthy control or Stanford type B AD groups.

CONCLUSION

This study characterized metabolomic profiles specifically associated with the pathogenesis and development of AD. The findings of this research may potentially lead to earlier diagnosis and treatment of AD.

Pericardial Inflammatory Mediators That Can Drive Postoperative Atrial Fibrillation in Cardiac Surgery Patients

Postoperative atrial fibrillation (POAF) is a common dysrhythmia that affects a significant number of patients undergoing cardiac surgery. Many studies aim to better understand this complex postsurgical complication by analysing circulating biomarkers in patients who develop POAF. More recently, the pericardial space was shown to contain inflammatory mediators that could trigger POAF. In this review we summarise recent studies that examine the immune mediators present in the pericardial space and their potential implications for the pathophysiology of POAF in cardiac surgery patients. Ongoing research in this area should better delineate the multifactorial etiology of POAF, where specific markers may be targeted to reduce the incidence of POAF and improve outcomes for this patient population.

Using urinary metabolomics to identify metabolic pathways linked to cardiac structural alterations in young adults: The African-PREDICT study

BACKGROUND AND AIMS

Risk factor exposure from young ages was shown to contribute to cardiovascular events - cardiac hypertrophy, which may be accompanied by an altered metabolism. To determine how early metabolic alterations associate with myocardial structural changes, we profiled urinary metabolites in young adults with cardiovascular disease (CVD) risk factor(s) and a control group without CVD risk factors.

METHODS AND RESULTS

We included healthy adults (N = 1202), aged 20-30 years, stratified based on risk factors, i.e., obesity, physical inactivity, elevated blood pressure (BP), hyperglycemia, dyslipidemia, low socio-economic status, smoking and excessive alcohol use - forming the CVD risk group (N = 1036) and the control group (N = 166). Relative wall thickness (RWT) and left ventricular mass index (LVMi) were measured using echocardiography. Targeted metabolomics data were obtained using a liquid chromatography-tandem mass spectrometry method. Clinic systolic BP, 24 h BP and RWT were higher in the CVD risk group compared to the control group (all P ≤ 0.031). Exclusively in the CVD risk group, RWT associated with creatine and dodecanoylcarnitine; while LVMi associated with glycine, serine, glutamine, threonine, alanine, citrulline, creatine, proline, pyroglutamic acid and glutamic acid (all P ≤ 0.040). Exclusively in the control group, LVMi associated with propionylcarnitine and butyrylcarnitine (all P ≤ 0.009).

CONCLUSION

In young adults without CVD, but with CVD risk factors, LVMi and RWT associated with metabolites linked energy metabolism (shifting from solely fatty acid oxidation to glycolysis, with impaired creatine kinase activity) and oxidative stress. Our findings support early onset metabolic changes accompanying cardiac structural alterations due to lifestyle and behavioural risk factors.

Prospects for Precision Medicine in Acute Myocardial Infarction: Patient-Level Insights into Myocardial Injury and Repair

The past decade has seen a marked expansion in the understanding of the pathobiology of acute myocardial infarction and the systemic inflammatory response that it elicits. At the same time, a portfolio of tools has emerged to characterise some of these processes in vivo. However, in clinical practice, key decision making still largely relies on assessment built around the timing of the onset of chest pain, features on electrocardiograms and measurements of plasma troponin. Better understanding the heterogeneity of myocardial injury and patient-level responses should provide new opportunities for diagnostic stratification to enable the delivery of more rational therapies. Characterisation of the myocardium using emerging imaging techniques such as the T1, T2 and T2* mapping techniques can provide enhanced assessments of myocardial statuses. Physiological measures, which include microcirculatory resistance and coronary flow reserve, have been shown to predict outcomes in AMI and can be used to inform treatment selection. Functionally informative blood biomarkers, including cellular transcriptomics; microRNAs; extracellular vesicle analyses and soluble markers, all give insights into the nature and timing of the innate immune response and its regulation in acute MI. The integration of these and other emerging tools will be key to developing a fuller understanding of the patient-level processes of myocardial injury and repair and should fuel new possibilities for rational therapeutic intervention.

Metabolomic profiling of cardiac allografts after controlled circulatory death

BACKGROUND

Assessment of myocardial viability during ex situ heart perfusion (ESHP) is based on the measurement of lactate concentrations. As this provides with limited information, we sought to investigate the metabolic signature associated with donation after circulatory death (DCD) and the impact of ESHP on the myocardial metabolome.

METHODS

Porcine hearts were retrieved either after warm ischemia (DCD group, N = 6); after brain-stem death (BSD group, N = 6); or without DCD nor BSD (Control group, N = 6). Hearts were perfused using normothermic oxygenated blood for 240 minutes. Plasma and myocardial samples were collected respectively every 30 and 60 minutes, and analyzed by an untargeted metabolomic approach using liquid chromatography coupled to high-resolution mass spectrometry.

RESULTS

Median duration of warm ischemia was 23 minutes [19-29] in DCD animals. Lactate level within myocardial biopsies was not significantly different between groups at T0 (p = 0.281), and remained stable over the 4-hour period of ESHP. More than 300 metabolites were detected in plasma and heart biopsy samples. Compared to BSD animals, metabolomics changes involving energy and nucleotide metabolisms were observed in plasma samples of DCD animals before initiation of ESHP, whereas 2 metabolites (inosine monophosphate and methylbutyrate) exhibited concentration changes in biopsy samples. Normalization of DCD metabolic profile was remarkable after 4 hours of ESHP.

CONCLUSION

A specific metabolic profile was observed in DCD hearts, mainly characterized by an increased nucleotide catabolism. DCD and BSD metabolomes proved normalized during ESHP. Complementary investigations are needed to correlate these findings to cardiac performances.

Diversity of cells and signals in the cardiovascular system

This white paper is the outcome of the seventh UC Davis Cardiovascular Research Symposium on Systems Approach to Understanding Cardiovascular Disease and Arrhythmia. This biannual meeting aims to bring together leading experts in subfields of cardiovascular biomedicine to focus on topics of importance to the field. The theme of the 2022 Symposium was 'Cell Diversity in the Cardiovascular System, cell-autonomous and cell-cell signalling'. Experts in the field contributed their experimental and mathematical modelling perspectives and discussed emerging questions, controversies, and challenges in examining cell and signal diversity, co-ordination and interrelationships involved in cardiovascular function. This paper originates from the topics of formal presentations and informal discussions from the Symposium, which aimed to develop a holistic view of how the multiple cell types in the cardiovascular system integrate to influence cardiovascular function, disease progression and therapeutic strategies. The first section describes the major cell types (e.g. cardiomyocytes, vascular smooth muscle and endothelial cells, fibroblasts, neurons, immune cells, etc.) and the signals involved in cardiovascular function. The second section emphasizes the complexity at the subcellular, cellular and system levels in the context of cardiovascular development, ageing and disease. Finally, the third section surveys the technological innovations that allow the interrogation of this diversity and advancing our understanding of the integrated cardiovascular function and dysfunction.

Urinary Exosomal Metabolites: Overlooked Clue for Predicting Cardiovascular Risk

Over the last decade, increasing research has focused on urinary exosomes (UEs) in biological fluids and their relationship with physiological and pathological processes. UEs are membranous vesicles with a size of 40-100 nm, containing a number of bioactive molecules such as proteins, lipids, mRNAs, and miRNAs. These vesicles are an inexpensive non-invasive source that can be used in clinical settings to differentiate healthy patients from diseased patients, thereby serving as potential biomarkers for the early identification of disease. Recent studies have reported the isolation of small molecules called exosomal metabolites from individuals' urine with different diseases. These metabolites could utilize for a variety of purposes, such as the discovery of biomarkers, investigation of mechanisms related to disease development, and importantly prediction of cardiovascular diseases (CVDs) risk factors, including thrombosis, inflammation, oxidative stress, hyperlipidemia as well as homocysteine. It has been indicated that alteration in urinary metabolites of N1-methylnicotinamide, 4-aminohippuric acid, and citric acid can be valuable in predicting cardiovascular risk factors, providing a novel approach to evaluating the pathological status of CVDs. Since the UEs metabolome has been clearly and precisely so far unexplored in CVDs, the present study has specifically addressed the role of the mentioned metabolites in the prediction of CVDs risk factors.

Fluoride induced metabolic disorder of endothelial cells

Endemic fluorosis is a global public health problem. Cardiovascular diseases caused by fluoride are closely related to endothelial cell injury. Metabolism disorder of endothelial cells (ECs) are recognized as the key factor of endothelial dysfunction which has been a hot topic in recent years. However, the toxic effect of fluoride on vascular endothelium has not been elucidated. The aim of this study was to explore the alteration of endothelial cell metabolites in Human Umbilical Vein Endothelial Cells (HUVECs) exposed to NaF using LC-MS/MS technique. The screening conditions were Variable Importance for the Projection (VIP) > 1 and P < 0.05. It was found that the expression of the metabolites Lumichrome and S-Methyl-5'-thioadenosine was upregulated and of the other metabolites, such as Creatine, L-Glutamate, Stearic acid was downregulated. Differential metabolites were found to be primarily related to FoxO、PI3K/Akt and apoptosis signaling pathways by Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis. From the perspective of metabolism, this study explored the possible mechanism of fluoride induced endothelial cell injury which providing theories and clues for subsequent studies.

Amino acid analysis as a method of discovering biomarkers for diagnosis of diabetes and its complications

Diabetes mellitus (DM) is a severe chronic diseases with a global prevalence of 9%, leading to poor health and high health care costs, and is a direct cause of millions of deaths each year. The rising epidemic of diabetes and its complications, such as retinal and peripheral nerve disease, is a huge burden globally. A better understanding of the molecular pathways involved in the development and progression of diabetes and its complications can facilitate individualized prevention and treatment. High diabetes mellitus incidence rate is caused mainly by lack of non-invasive and reliable methods for early diagnosis, such as plasma biomarkers. The incidence of diabetes and its complications in the world still grows so it is crucial to develop a new, faster, high specificity and more sensitive diagnostic technologies. With the advancement of analytical techniques, metabolomics can identify and quantify multiple biomarkers simultaneously in a high-throughput manner, and effective biomarkers can greatly improve the efficiency of diabetes and its complications. By providing information on potential metabolic pathways, metabolomics can further define the mechanisms underlying the progression of diabetes and its complications, help identify potential therapeutic targets, and improve the prevention and management of T2D and its complications. The application of amino acid metabolomics in epidemiological studies has identified new biomarkers of diabetes mellitus (DM) and its complications, such as branched-chain amino acids, phenylalanine and arginine metabolites. This study focused on the analysis of metabolic amino acid profiling as a method for identifying biomarkers for the detection and screening of diabetes and its complications. The results presented are all from recent studies, and in all cases analyzed, there were significant changes in the amino acid profile of patients in the experimental group compared to the control group. This study demonstrates the potential of amino acid profiles as a detection method for diabetes and its complications.

Multiple targets related to mitochondrial function unveiled by metabolomics and proteomics profiles of hearts from atrial fibrillation patients

Background: The prominent mitochondrial metabolic changes of the atrium reportedly have significant impact on electrical signals and structural remodeling which play important roles in the occurrence and development of atrial fibrillation (AF). However, the mechanism is not completely known.

Objective: This study was aimed to explore the mitochondrial metabolism reprogrammed in AF patients by integrating metabolomics as well as proteomics of human atrium tissues.

Methods and Results: Left atrial tissue samples were harvested from 10 non-valvular AF patients and 10 matched samples from healthy donors for transplantation. In metabolomics analysis, 113 metabolites were upregulated and 10 metabolites were downregulated in AF, where multiple pathways related to mitochondrial energy metabolism were enriched. Correlation analysis between the differentially expressed proteins and metabolites identified several hub proteins related to mitochondrial function including Glycerol-3-phosphate dehydrogenase 2 (GPD2), Synemin (SYNM), Plectin (PLEC), with MCC score of 27, 17, 16, respectively, which have the most interactions with the dysregulated metabolites and ranked at the top in network string interactions scored by MCC method. All 330 differentially expressed proteins including 225 upregulated and 105 downregulated molecules were revealed and analyzed, which identified the downregulation of GPD2 (p = 0.02 and FC = 0.77), PLEC (p &lt; 0.001 and FC = 0.71) and SYNM (p = 0.04 and FC = 0.76) in AF patients. Gene Set Variation Analysis (GSEA) showed mitochondrial metabolism-associated pathways including oxidative phosphorylation (NES: −1.73) and ATP biosynthetic process (NES: −2.29), were dramatically diversified in human AF. In GSVA, the expression levels of GPD2, PLEC, and SYNM were demonstrated to be associated with multiple metabolic pathways related to mitochondrial function (e.g., lipid metabolism and AMP activated protein kinase signaling) and cardiac structural and electrical remodeling (e.g., contractile fiber, ion homeostasis), which were proven vital in the development and maintenance of AF.

Conclusion: In all, this study provides new insights into understanding the mechanisms of AF progression, especially the reprogramming mitochondrial metabolism, and identifies several genes related to mitochondrial function as novel targets for AF, which may be involved in the occurrence and development of AF.

Metabolomics of early myocardial ischemia

INTRODUCTION

Diagnosing myocardial infarction is difficult during the initial phase. As, acute myocardial ischemia is associated with changes in metabolic pathways, metabolomics may provide ways of identifying early stages of ischemia. We investigated the changes in metabolites after induced ischemia in humans using nuclear magnetic resonance spectroscopy (NMR).

METHODS

We included patients undergoing elective coronary angiography showing normal coronary arteries. These were randomized into 4 groups and underwent coronary artery occlusion for 0, 30, 60 or 90 s. Blood was collected over the next 3 h and analyzed using NMR. We used 2-way ANOVA of time from baseline- and treatment group to find metabolites that changed significantly following the intervention and principal component analysis (PCA) to investigate changes between the 90 s ischemia- and control groups at 15 and 60 min after intervention.

RESULTS

We included 34 patients. The most pronounced changes were observed in the lipid metabolism where 38 of 112 lipoprotein parameters (34%) showed a significant difference between the patients exposed to ischemia and the control group. There was a decrease in total plasma triglycerides over the first hour followed by a normalization. The principal component analysis showed a effects of the treatment after just 15 min. These effects were dominated by changes in high-density lipoprotein. An increase in lactic acid levels was detected surprisingly late, 1-2 h after the ischemia.

CONCLUSION

We investigated the earliest changes in metabolites of patients undergoing brief myocardial ischemia and found that ischemia led to changes throughout the lipid metabolism as early as 15 min post-intervention.

Multiomics Network Medicine Approaches to Precision Medicine and Therapeutics in Cardiovascular Diseases

Cardiovascular diseases (CVD) are the leading cause of death worldwide and display complex phenotypic heterogeneity caused by many convergent processes, including interactions between genetic variation and environmental factors. Despite the identification of a large number of associated genes and genetic loci, the precise mechanisms by which these genes systematically influence the phenotypic heterogeneity of CVD are not well understood. In addition to DNA sequence, understanding the molecular mechanisms of CVD requires data from other omics levels, including the epigenome, the transcriptome, the proteome, as well as the metabolome. Recent advances in multiomics technologies have opened new precision medicine opportunities beyond genomics that can guide precise diagnosis and personalized treatment. At the same time, network medicine has emerged as an interdisciplinary field that integrates systems biology and network science to focus on the interactions among biological components in health and disease, providing an unbiased framework through which to integrate systematically these multiomics data. In this review, we briefly present such multiomics technologies, including bulk omics and single-cell omics technologies, and discuss how they can contribute to precision medicine. We then highlight network medicine-based integration of multiomics data for precision medicine and therapeutics in CVD. We also include a discussion of current challenges, potential limitations, and future directions in the study of CVD using multiomics network medicine approaches.

Mass spectrometry-based metabolomics for discovering active ingredients and exploring action mechanism of herbal medicine

Natural products derived from herbal medicine are a fruitful source of lead compounds because of their structural diversity and potent bioactivities. However, despite the success of active compounds derived from herbal medicine in drug discovery, some approaches cannot effectively elucidate the overall effect and action mechanism due to their multi-component complexity. Fortunately, mass spectrometry-based metabolomics has been recognized as an effective strategy for revealing the effect and discovering active components, detailed molecular mechanisms, and multiple targets of natural products. Rapid identification of lead compounds and isolation of active components from natural products would facilitate new drug development. In this context, mass spectrometry-based metabolomics has established an integrated pharmacology framework for the discovery of bioactivity-correlated constituents, target identification, and the action mechanism of herbal medicine and natural products. High-throughput functional metabolomics techniques could be used to identify natural product structure, biological activity, efficacy mechanisms, and their mode of action on biological processes, assisting bioactive lead discovery, quality control, and accelerating discovery of novel drugs. These techniques are increasingly being developed in the era of big data and use scientific language to clarify the detailed action mechanism of herbal medicine. In this paper, the analytical characteristics and application fields of several commonly used mass spectrometers are introduced, and the application of mass spectrometry in the metabolomics of traditional Chinese medicines in recent years and its active components as well as mechanism of action are also discussed.