Plasma metabolites mediate the effect of HbA1c on incident cardiovascular disease

Disease patterns of coronary heart disease and type 2 diabetes harbored distinct and shared genetic architecture

BACKGROUND

Coronary heart disease (CHD) and type 2 diabetes (T2D) are two complex diseases with complex interrelationships. However, the genetic architecture of the two diseases is often studied independently by the individual single-nucleotide polymorphism (SNP) approach. Here, we presented a genotypic-phenotypic framework for deciphering the genetic architecture underlying the disease patterns of CHD and T2D.

METHOD

A data-driven SNP-set approach was performed in a genome-wide association study consisting of subpopulations with different disease patterns of CHD and T2D (comorbidity, CHD without T2D, T2D without CHD and all none). We applied nonsmooth nonnegative matrix factorization (nsNMF) clustering to generate SNP sets interacting the information of SNP and subject. Relationships between SNP sets and phenotype sets harboring different disease patterns were then assessed, and we further co-clustered the SNP sets into a genetic network to topologically elucidate the genetic architecture composed of SNP sets.

RESULTS

We identified 23 non-identical SNP sets with significant association with CHD or T2D (SNP-set based association test, P < 3.70 × [Formula: see text]). Among them, disease patterns involving CHD and T2D were related to distinct SNP sets (Hypergeometric test, P < 2.17 × [Formula: see text]). Accordingly, numerous genes (e.g., KLKs, GRM8, SHANK2) and pathways (e.g., fatty acid metabolism) were diversely implicated in different subtypes and related pathophysiological processes. Finally, we showed that the genetic architecture for disease patterns of CHD and T2D was composed of disjoint genetic networks (heterogeneity), with common genes contributing to it (pleiotropy).

CONCLUSION

The SNP-set approach deciphered the complexity of both genotype and phenotype as well as their complex relationships. Different disease patterns of CHD and T2D share distinct genetic architectures, for which lipid metabolism related to fibrosis may be an atherogenic pathway that is specifically activated by diabetes. Our findings provide new insights for exploring new biological pathways.

Unraveling the Serum Metabolomic Profile of Acrylamide-Induced Cardiovascular Toxicity

Acrylamide has been reported as an important dietary risk factor from carbohydrate-rich processing food. However, systemic biological effects on the serum metabolomics induced by acrylamide have poorly been understood. In the present study, we evaluated the metabolic profiles in a rat serum after exposure to acrylamide using ultrahigh-performance liquid chromatography combined with quadrupole-orbitrap high-resolution mass spectrometry. The serum biochemical parameters of the treated and control groups were also determined using an automatic biochemical analyzer. Compared with the control group, 10 metabolites were significantly upregulated, including citric acid, d-(-)-fructose, gluconic acid, l-ascorbic acid 2-sulfate, 2-hydroxycinnamic acid, valine, l-phenylalanine, prolylleucine, succinic acid, and cholic acid, while 5 metabolites were significantly downregulated, including 3-hydroxybutyric acid, 4-oxoproline, 2,6-xylidine, 4-phenyl-3-buten-2-one, and N-ethyl-N-methylcathinone in the serum of 4-week-old rats exposed to acrylamide in the high-dose group (all P < 0.05). Importantly, acrylamide exposure affected metabolites mainly involved in the citrate cycle, valine, leucine, and isoleucine biosyntheses, phenylalanine, tyrosine and tryptophan biosyntheses, and pyruvate metabolism. These results suggested that exposure to acrylamide in rats exhibited marked systemic metabolic changes and affected the cardiovascular system. This study will provide a theoretical basis for exploring the toxic mechanism and will contribute to the diagnosis and prevention of acrylamide-induced cardiovascular toxicity.

Serum Metabolomics Reveals Underlying Mechanisms of Cholesterol-Lowering Effects of Oat Consumption: A Randomized Controlled Trial in a Mildly Hypercholesterolemic Population

INTRODUCTION

The purpose of this study is to examine the effects of oat supplementation on serum lipid in a population of adults with mild hypercholesterolemia and reveal the underlying mechanisms with serum untargeted metabolomics.

METHODS AND RESULTS

In this placebo-controlled trial, 62 participants from Nanjing, China, with mild elevations in cholesterol are randomly assigned to receive 80 g oats (containing 3 g beta-glucan) or rice daily for 45 days. Fasting blood samples are collected at the beginning, middle, and end of the trial. Compared with the rice group, oat consumption significantly decreases serum total cholesterol (TC) (-8.41%, p = 0.005), low-density lipoprotein cholesterol (LDL-c) (-13.93%, p = 0.001), and non high-density lipoprotein cholesterol (non-HDL-c) (-10.93%, p = 0.017) levels. There are no significant between-group differences in serum triglyceride (TG), apolipoprotein B (Apo B), glycated albumin, or fasting blood glucose levels. An orthogonal partial least squares discriminant analysis (OPLS-DA) suggests a clear separation in metabolic profiles between the groups after the intervention. Twenty-one metabolites in the oat group are significantly different from those in the rice group, among which 14 metabolites show a decreased trend. In comparison, seven metabolites show an increased trend. Correlations analysis from both groups indicate that most metabolites [e.g., sphinganine and phosphatidylcholine (PC)(20:5(5Z,8Z,11Z,14Z,17Z)/20:1(11Z))] have positive correlations with serum cholesterol levels. Kyoto Encyclopedia of Gene and Genomes pathway analysis suggests that oat consumption regulated glycerophospholipid, alanine, aspartate and glutamate, sphingolipid, and retinol metabolism.

CONCLUSION

Oat consumption has beneficial effects on serum lipids profiles. The underlying mechanisms involve glycerophospholipid, alanine, aspartate and glutamate, sphingolipid, and retinol metabolism in adults.

The mediation effect of serum metabolites on the relationship between long-term smoking exposure and esophageal squamous cell carcinoma

BACKGROUND

Long-term smoking exposure will increase the risk of esophageal squamous cell carcinoma (ESCC), whereas the mechanism is still unclear. We conducted a cross-sectional study to explore whether serum metabolites mediate the occurrence of ESCC caused by cigarette smoking.

METHODS

Serum metabolic profiles and lifestyle information of 464 participants were analyzed. Multiple logistic regression was used to estimate adjusted odds ratios (ORs) and 95% confidence intervals (CIs) of smoking exposure to ESCC risk. High-dimensional mediation analysis and univariate mediation analysis were performed to screen potential intermediate metabolites of smoking exposure for ESCC.

RESULTS

Ever smoking was associated with a 3.11-fold increase of ESCC risk (OR = 3.11, 95% CI 1.63-6.05), and for each cigarette-years increase in smoking index, ESCC risk increased by 56% (OR = 1.56, 95% CI 1.18-2.13). A total of 5 metabolites were screened as mediators by high-dimensional mediation analysis. In addition, glutamine, histidine, and cholic acid were further proved existing mediation effects according to univariate mediation analysis. And the proportions of mediation of histidine and glutamine were 40.47 and 30.00%, respectively. The mediation effect of cholic acid was 8.98% according to the analysis of smoking index.

CONCLUSIONS

Our findings suggest that cigarette smoking contributed to incident ESCC, which may be mediated by glutamine, histidine and cholic acid.

Study of the Mechanism of Action of Guanxin Shutong Capsules in the Treatment of Coronary Heart Disease Based on Metabolomics

Background: Guan-Xin-Shu-Tong capsule (GXSTC) is a traditional Chinese medicine (TCM) that has been used to treat coronary heart disease (CHD) for many years in China. However, the holistic mechanism of GXSTC against CHD is still unclear. Therefore, the purpose of this paper was to systematically explore the mechanism of action GXSTC in the treatment of CHD rats using a metabolomics strategy.

Methods: A CHD model was induced by ligation of the left anterior descending coronary artery (LAD). In each group, echocardiography was performed; the contents of creatine kinase (CK), lactate dehydrogenase (LDH) and aspartate transaminase (AST) in serum were determined; and the myocardial infarct size was measured. The metabolites in plasma were analyzed by UHPLC-MS/MS-based untargeted metabolomics. Then, multivariate statistical analysis was performed to screen potential biomarkers associated with the GXSTC treatment in the LAD-induced rat CHD model. Finally, the MetaboAnalyst 4.0 platform was used for metabolic pathway enrichment analysis.

Results: GXSTC was able to regulate the contents of CK, LDH and AST; restore impaired cardiac function; and significantly reduce the myocardial infarction area in model rats. Twenty-two biomarkers and nine metabolic pathways of GXSTC in the treatment of CHD were identified through UHPLC-MS/MS-based untargeted metabolomics analysis.

Conclusion: GXSTC regulates metabolic disorders of endogenous components in LAD-induced CHD rats. The anti-CHD mechanism of GXSTC is mainly related to the regulation of amino acid, lipid and hormonal metabolism. This study provides an overall view of the mechanism underlying the action of GXSTC against CHD.

Plasma metabolites mediate the effect of HbA1c on incident cardiovascular disease

Background

We aim to discover whether HbA1c affects incident cardiovascular disease (CVD) through regulating endogenous metabolites.

Methods and Results

Totally, 2019 plasma samples were analyzed by liquid chromatography‐quadrupole time‐of‐flight mass spectrometry. Logistic regression and linear regression were used to screen metabolites which were associated with both CVD and HbA1c. The VanderWeele's mediation approach was performed to assess the direct effect and indirect effect (IE) in the counterfactual model. Forty‐eight metabolites showed an association with both HbA1c and CVD risk. Forty‐four of the 48 metabolites worked as mediators mediated in HbA1c's effect on CVD (odds ratio [OR]_IE from 0.997 to 6.098, false discovery rate q < 0.05, mediated proportion from 0.4% to 85.4%). Pathway enrichment analysis indicated that different metabolic pathway showed significant IE (butanoate metabolism OR_IE = 1.058, mediated proportion = 16.0%; alanine, aspartate and glutamate metabolism OR_IE = 1.082, mediated proportion = 21.8%; TCA (citric acid) cycle metabolism OR_IE = 1.048, mediated proportion = 13.8%; phenylalanine metabolism OR_IE = 1.067, mediated proportion = 18.4%; glycerophospholipid metabolism OR_IE = 3.007, mediated proportion = 82.2%; all the P < .01).

Conclusions

Our findings suggest that metabolites mediate the effect of HbA1c on incident CVD and provide a new study sight into pathogenesis of CVD.