Metabolomic analysis of serum from obese adults with hyperlipemia by UHPLC-Q-TOF MS/MS

Circulating bacterial peptides and linked metabolomic signatures are indicative of early mortality in pediatric cirrhosis

BACKGROUND

Patients with pediatric cirrhosis-sepsis (PC-S) attain early mortality. Plasma bacterial composition, the cognate metabolites, and their contribution to the deterioration of patients with PC-S to early mortality are unknown. We aimed to delineate the plasma metaproteome-metabolome landscape and identify molecular indicators capable of segregating patients with PC-S predisposed to early mortality in plasma, and we further validated the selected metabolite panel in paired 1-drop blood samples using untargeted metaproteomics-metabolomics by UHPLC-HRMS followed by validation using machine-learning algorithms.

METHODS

We enrolled 160 patients with liver diseases (cirrhosis-sepsis/nonsepsis [n=110] and noncirrhosis [n=50]) and performed untargeted metaproteomics-metabolomics on a training cohort of 110 patients (Cirrhosis-Sepsis/Nonsepsis, n=70 and noncirrhosis, n=40). The candidate predictors were validated on 2 test cohorts-T1 (plasma test cohort) and T2 (1-drop blood test cohort). Both T1 and T2 had 120 patients each, of which 70 were from the training cohort.

RESULTS

Increased levels of tryptophan metabolites and Salmonella enterica and Escherichia coli-associated peptides segregated patients with cirrhosis. Increased levels of deoxyribose-1-phosphate, N5-citryl-d-ornithine, and Herbinix hemicellulolytic and Leifsonia xyli segregated patients with PC-S. MMCN-based integration analysis of WMCNA-WMpCNA identified key microbial-metabolic modules linked to PC-S nonsurvivors. Increased Indican, Staphylobillin, glucose-6-phosphate, 2-octenoylcarnitine, palmitic acid, and guanidoacetic acid along with L. xyli, Mycoplasma genitalium, and Hungateiclostridium thermocellum segregated PC-S nonsurvivors and superseded the liver disease severity indices with high accuracy, sensitivity, and specificity for mortality prediction using random forest machine-learning algorithm.

CONCLUSIONS

Our study reveals a novel metabolite signature panel capable of segregating patients with PC-S predisposed to early mortality using as low as 1-drop blood.

A unique inflammation-related mechanism by which high-fat diets induce depression-like behaviors in mice

BACKGROUND

High-fat diet (HFD) consumption is an important reason for promoting depression, but the mechanism is unclear. The present study aims to explore the relationship between metabolic disturbance and HFD-induced depression-like behaviors.

METHODS

Depression models were established by HFD consumption and chronic unpredictable mild stress (CUMS) in mice. Enzyme-linked immunosorbent assay, western blotting, real-time polymerase chain reaction, gas chromatography and metabolomic analysis were undertaken to investigate the 5-hydroxytryptamine (5-HT) system, neuroinflammation and to identify altered lipid metabolic pathways.

RESULTS

Depression-like behaviors, impaired 5-HT neurotransmission and disordered lipid metabolism were observed upon HFD consumption. Despite a similar reduction of high-density lipoprotein cholesterol in CUMS and HFD group, high levels of body low-density lipoprotein cholesterol in the HFD group could help distinguish HFD from CUMS. Levels of interleukin (IL)-1β, IL-6, tumor necrosis factor (TNF)-α and inflammation-related metabolites were increased in HFD mice, so a link between depression and inflammation was postulated. Different metabolites were enriched in the two groups. The linoleic acid (LA) metabolic pathway and expression of fatty acid desaturase (FADS)1 and FADS2 (key enzymes in LA metabolic pathway) were enhanced significantly in HFD mice compared with the control group.

LIMITATIONS

Causality analyses for HFD and inflammation-related features were not undertaken.

CONCLUSIONS

HFD-induced depression-like behaviors was characterized by more severely disordered metabolism of lipids (especially in the LA metabolic pathway) and increased levels of inflammatory mediators, which might be the reasons for the disturbance of serotonergic system in hippocampus.

Analysis of the mechanism of action of quercetin in the treatment of hyperlipidemia based on metabolomics and intestinal flora

Hyperlipidemia (HLP) is one of the main factors leading to cardiovascular diseases. Quercetin (QUE) is a naturally occurring polyhydroxy flavonoid compound that has a wide range of pharmacological effects. However, the potential mechanism for treating HLP remains unclear. Thus, the study aimed to investigate the role of QUE in HLP development and its underlying mechanisms in HLP rats based on the analysis of gut microbiota and plasma metabolomics. Following the establishment of an HLP model in rats, QUE was orally administered. Plasma samples and fecal samples were collected from HLP rats for microbiome 16S rDNA sequencing and metabolic UPLC-Q-Exactive-MS analysis. The results suggested that QUE could regulate dyslipidemia and inhibit the levels of TC, TG, and LDL-c. Additionally, histopathological findings revealed that QUE could reduce lipid deposition, ameliorate hepatic injury and steatosis in HFD-induced rats, and have a protective effect on the liver. The analysis and identification of plasma metabolomics showed that the intervention effect of QUE on HLP rats was related to 60 differential metabolites and signal pathways such as lactosamine, 11b-hydroxyprogesterone, arachidonic acid, glycerophospholipid, sphingolipid, glycerolipid, and linoleic acid metabolism. Combined with fecal microbiological analysis, it was found that QUE could significantly change the composition of intestinal flora in HLP rats, increase beneficial bacteria, and reduce the composition of harmful bacteria, attenuating the Firmicutes/Bacteroidetes ratio. The results of correlation analysis showed that the relative abundance level of Firmicutes, Deironobacterium, Fusobacterium, Bacteroides, and Escherichia coli was closely related to the change of differential metabolites. In summary, combined with metabolomics and gut microbiota studies, it is found that QUE can reduce lipid levels and improve liver function. The potential mechanism may be the regulation of metabolism and intestinal flora that play a role in reducing lipid levels, to achieve the purpose of treatment of HLP.

Systematic metabolomic studies identified adult adiposity biomarkers with acetylglycine associated with fat loss in vivo

Obesity is associated with various adverse health outcomes. Body fat (BF) distribution is recognized as an important factor of negative health consequences of obesity. Although metabolomics studies, mainly focused on body mass index (BMI) and waist circumference, have explored the biological mechanisms involved in the development of obesity, these proxy composite measures are not accurate and cannot reflect BF distribution, and thus may hinder accurate assessment of metabolic alterations and differential risk of metabolic disorders among individuals presenting adiposity differently throughout the body. Thus, the exact relations between metabolites and BF remain to be elucidated. Here, we aim to examine the associations of metabolites and metabolic pathways with BF traits which reflect BF distribution. We performed systematic untargeted serum metabolite profiling and dual-energy X-ray absorptiometry (DXA) whole body fat scan for 517 Chinese women. We jointly analyzed DXA-derived four BF phenotypes to detect cross-phenotype metabolite associations and to prioritize important metabolomic factors. Topology-based pathway analysis was used to identify important BF-related biological processes. Finally, we explored the relationships of the identified BF-related candidate metabolites with BF traits in different sex and ethnicity through two independent cohorts. Acetylglycine, the top distinguished finding, was validated for its obesity resistance effect through in vivo studies of various diet-induced obese (DIO) mice. Eighteen metabolites and fourteen pathways were discovered to be associated with BF phenotypes. Six of the metabolites were validated in varying sex and ethnicity. The obesity-resistant effects of acetylglycine were observed to be highly robust and generalizable in both human and DIO mice. These findings demonstrate the importance of metabolites associated with BF distribution patterns and several biological pathways that may contribute to obesity and obesity-related disease etiology, prevention, and intervention. Acetylglycine is highlighted as a potential therapeutic candidate for preventing excessive adiposity in future studies.

Overall metabolic network analysis of urine in hyperlipidemic rats treated with Bidens bipinnata L

Hyperlipidemia has been highlighted as one of the most prominent and global chronic conditions nowadays. Bidens bipinnata L. (BBL), a folk medicine in contemporary China, has efficacy in the treatment of hyperlipidemia (HLP) in China. Although some physiological and pathological function parameters of hyperlipidemia have been investigated, little information about the changes in small metabolites in biofluids has been reported. In the present study, global metabolic profiling with high-performance liquid chromatography-linear ion trap/Orbitrap high-resolution mass spectrometry (HPLC-LTQ/Orbitrap MS) combined with a pattern recognition method was performed to discover the underlying lipid-regulating mechanisms of BBL on hyperlipidemic rats induced by high-fat diet (HFD). The total of four metabolites, up- or down-regulated (p < 0.05 or 0.01), were identified and contributed to the progression of hyperlipidemia. These promising identified biomarkers underpin the metabolic pathway, including glyoxylate and dicarboxylate metabolism, the TCA cycle, sphingolipid metabolism and purine metabolism. They are disturbed in hyperlipidemic rats, and are identified using pathway analysis with MetPA. The altered metabolite indices could be regulated closer to normal levels after BBL intervention. The results demonstrated that urinary metabolomics is a powerful tool in the clinical diagnosis and treatment of hyperlipidemia to provide information on changes in metabolite pathways.

Effect of Bergamot and Laoxianghuang Polysaccharides on Gut Microbiota Derived from Patients with Hyperlipidemia: An Integrative Analysis of Microbiome and Metabolome during In Vitro Fermentation

The aim of this study was to investigate the effects of bergamot polysaccharide (BP) and Laoxianghuang polysaccharides (LPs, fermented bergamot) on the microbiome and metabolome during the in vitro fermentation of gut microbiota from patients with hyperlipidemia. Results indicated that both BP and LPs were able to increase the production of acetic acid, propionic acid, and butyric acid. However, only LPs could decrease the content of isobutyric acid and isovaleric acid, which are detrimental to gut health. A 16S rRNA analysis showed that both BP and LPs could reduce the proportion of Fusobacterium, whereas they increased the Bacteroides content in hyperlipidemia. Untargeted UPLC-MS/MS metabolomic profiling found six bio-markers that were significantly changed after BP and LPs intervention, and four of the down-regulated metabolites were long-chain fatty acids associated with vascular diseases. These findings provide new evidence that BP and LPs have the potential to regulate imbalances in the gut microbiota in patients with hyperlipidemia and ameliorate its metabolic abnormalities.

Integrative analysis of multi-omics data to detect the underlying molecular mechanisms for obesity in vivo in humans

BACKGROUND

Obesity is a complex, multifactorial condition in which genetic play an important role. Most of the systematic studies currently focuses on individual omics aspect and provide insightful yet limited knowledge about the comprehensive and complex crosstalk between various omics levels.

SUBJECTS AND METHODS

Therefore, we performed a most comprehensive trans-omics study with various omics data from 104 subjects, to identify interactions/networks and particularly causal regulatory relationships within and especially those between omic molecules with the purpose to discover molecular genetic mechanisms underlying obesity etiology in vivo in humans.

RESULTS

By applying differentially analysis, we identified 8 differentially expressed hub genes (DEHGs), 14 differentially methylated regions (DMRs) and 12 differentially accumulated metabolites (DAMs) for obesity individually. By integrating those multi-omics biomarkers using Mendelian Randomization (MR) and network MR analyses, we identified 18 causal pathways with mediation effect. For the 20 biomarkers involved in those 18 pairs, 17 biomarkers were implicated in the pathophysiology of obesity or related diseases.

CONCLUSIONS

The integration of trans-omics and MR analyses may provide us a holistic understanding of the underlying functional mechanisms, molecular regulatory information flow and the interactive molecular systems among different omic molecules for obesity risk and other complex diseases/traits.

Rhus chinensis Mill. Fruits Ameliorate Hepatic Glycolipid Metabolism Disorder in Rats Induced by High Fat/High Sugar Diet

Hepatic glycolipid metabolism disorder is considered as one of the key factors in the pathogenesis of many chronic diseases. The objective of this study was to investigate the protective effect and underlying mechanisms of Rhus chinensis Mill. fruits against hepatic glycolipid metabolic disorders in rats induced by a high fat/high sugar diet. Results showed that ethanol extract, especially at a dose of 600 mg/kg b.w., could effectively ameliorate glycolipid metabolic disorders in rats. The biochemical indexes, including CAT, GSH and HOMA-IR, were significantly improved by the administration of ethanol extract. Immunohistochemistry and Western blot analysis revealed that ethanol extract up-regulated the expression levels of PI3K/AKT, PPAR-α, and the phosphorylation of IRS1 and AMPK proteins, and down-regulated the expressions of SREBP-1 and FAS proteins in the liver, which are closely related to hepatic glycolipid metabolism. Those findings suggested that R. chinensis Mill. fruits could be developed as functional foods and/or nutraceuticals for preventing or controlling some chronic diseases related to hepatic glycolipid metabolism disorder.

Metabolomic analysis reveals potential biomarkers and serum metabolomic profiling in spontaneous intracerebral hemorrhage patients using UPLC/quadrupole time-of-flight MS

Spontaneous intracerebral hemorrhage (ICH) accounts for 10-20% of all strokes and contributes to higher mortalities and severe disabilities. The aims of this study were, therefore, to characterize novel biomarkers, metabolic disruptions, and mechanisms involving ICH. A total 30 ICH patients and 30 controls were enrolled in the study, and their clinical characteristics were analyzed. Nontargeted metabolomic analysis was conducted using ultra-performance liquid chromatography quadrupole time-of-flight tandem mass spectrometry (UPLC/Q-TOF). Multivariate statistical analysis and receiver operating characteristic curve analysis were used for screening and evaluating the predictive ability of biomarkers. ICH patients showed significantly higher systolic blood pressure, diastolic blood pressure, blood glucose levels, white blood cell counts, neutrophil count, percentage of neutrophils and globulin and a lower albumin/globin ratio when compared with controls. In sum, 11 important metabolites were identified, which were associated with disruption of fatty acid oxidation and sphingolipid and phospholipid metabolism, as well as increased inflammation, oxidative stress, and vascular pathologies. Further multiple logistic regression analyses of these metabolites showed that l-carnitine and phosphatidylcholine (20:3/22:6) have potential as biomarkers of ICH, and the area under the curve, sensitivity, specificity were 0.974, 90%, and 93%, respectively. These findings provide insights into the pathogenesis, early prevention, and diagnosis of ICH.

Metabolomic analysis of plasma from normal-weight adults with hypo-HDL cholesterolemia by UPLC-QTOF MS

High-density lipoprotein cholesterol (HDL-C) is negatively correlated with atherosclerotic cardiovascular disease. The prevalence of hypo-HDL cholesterolemia is as high as 33.9%. The plasma metabolomic differences between hypo-HDL cholesterolemia populations and normal controls were investigated using ultra-high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry. Participants with hypo-HDL cholesterolemia and normal controls were clearly discriminated from each other on the orthogonal partial least squares-discriminant analysis score plot and a total of 90 differential metabolites were identified, including down-regulated phosphatidylserine [18:0/20:3(8Z,11Z,14Z)], phosphatidylcholine [19:0/18:3(6Z,9Z,12Z)], phosphatidylserine, phosphatidylethanolamine [18:0/20:4(5Z,8Z,11Z,13E) (15Ke)], etc., and up-regulated triglyceride [15:0/18:1(9Z)/18:3(9Z,12Z,15Z)][iso6], 13-methyl-1-tritriacontene, tridodecylamine, etc. Most of the changed metabolites were lipids, notably, a significant part of which were odd chain fatty acid incorporated lipids. Carnitine shuttle was the most significant metabolic pathway, except for the disturbed glycerophospholipid metabolism, glycosphingolipid metabolism and sphingolipid metabolism in participants with hypo-HDL cholesterolemia. We identified the key metabolites and metabolic pathways that may be changed in hypo-HDL cholesterolemia participants, providing useful clues for studying the metabolic mechanisms and for early prevention of hypo-HDL cholesterolemia and dyslipidemia.

Plasma metabolomics analysis of the effects of drinking soda water on hyperglycemia mice using ultrahigh-pressure liquid chromatography-quadrupole-time of flight-mass spectrometry

The aim of this study was to evaluate the effects of a natural soda water [Shi Han Quan (SHQ)] on hyperglycemia and plasma metabolic profiling and explore the mechanism using metabolomics techniques. Kun-Ming mice weighing 26 ± 2 g were used for the hyperglycemia animal model with alloxan and divided into control, hyperglycemia (HG), and HG + SHQ soda water (SHQ) groups. The experiment lasted for 30 days. The plasma metabolomic profiling of mice was determined using ultrahigh-pressure liquid chromatography-quadrupole-time of flight-mass spectrometry. After the mice drank SHQ soda water, the levels of insulin and blood glucose were significantly lower in the SHQ group compared with the control group, and the level of insulin sensitivity [insulin sensitivity index (ISI)] was significantly higher in the SHQ group compared with the HG group. The mice in the different groups after SHQ intervention could be separated into distinct clusters, and nine major plasma metabolites with significant differences between groups were found closely associated with blood glucose and ISI. The metabolic pathway analysis of these metabolites involved abnormal fatty acid oxidation and phospholipid, acylcarnitine, and corticoid metabolism. The results suggested the metabolic changes and possible mechanism of SHQ improving the alloxan-induced HG, and the findings provided insights into the prevention and control of HG and diabetes.

Study on urine metabolic profiling and pathogenesis of hyperlipidemia

BACKGROUND

As a recognized risk factor for cardiovascular disease (CVD), hyperlipidemia (HLP) has developed into a high incidence disease that seriously threatens human health. Finding a new target for effective treatment of HLP will be a powerful way to reduce the incidence of CVD. The purpose of this study was to find potential biomarkers in urine of HLP patients and analyze their metabolic pathways to study the pathogenesis of HLP.

METHODS

An UPLC-Q-TOF/MS technology was used to detect the metabolites in urine of 60 HLP patients and 60 normal controls. Based on PLS-DA pattern recognition, potential biomarkers related to HLP were screened out.

RESULTS

22 potential biomarkers related to HLP were identified, which involved amino acid metabolism, fatty acid metabolism, nucleotide metabolism, steroid hormone metabolism and intestinal flora metabolism, and their possible pathogenesis was found to be related to inflammatory reaction and oxidative stress.

CONCLUSION

The non-targeted metabolomic method based on UPLC-Q-TOF/MS technology can effectively identify potential biomarkers in the urine of HLP patients and explore the possible pathogenesis. Our research will lay a foundation for finding new targets for the treatment of HLP and provide a basis for clinical research on the treatment of HLP.

Metabolomics Analyses to Investigate the Role of Diet and Physical Training

The metabolic and physiologic responses to healthy dietary habits and physical exercise have become an increasingly interesting research area, since equilibrated diet and regular physical activity are commonly recommended for their antioxidant capacity and for the prevention and treatment of several disorders as insulin resistance, dyslipidemia, obesity, and hypertension that may result in cardiovascular disease and type II diabetes.Nutritional and exercise-induced responses and the biological mechanisms that explain these associations have been tackled by several researchers using metabolomic approaches that have emerged as a powerful tool to comprehensively evaluate individual metabolic signatures, analyzing metabolome composition in serum, urine, stool, or tissue samples.The overview of the wide range of metabolites related to dietary and to physical training interventions reported from numerous human or animal studies endorses the complexity for assessing metabolic changes and compound identification, and a combination of targeted and non-targeted global profiling studies is recommended for increasing the understanding of nutrition and exercise metabolic mechanisms.The present protocol attempt to identify variations in human blood circulating metabolites with a multiplatform global analysis based on LC-MS, GC-MS, and NMR, combining targeted and untargeted strategies, to complete the holistic understanding of the serum metabolome.

Potential serum biomarkers and metabonomic profiling of serum in ischemic stroke patients using UPLC/Q-TOF MS/MS

Background

Stroke still has a high incidence with a tremendous public health burden and it is a leading cause of mortality and disability. However, biomarkers for early diagnosis are absent and the metabolic alterations associated with ischemic stroke are not clearly understood. The objectives of this case-control study are to identify serum biomarkers and explore the metabolic alterations of ischemic stroke.

Methods

Metabonomic analysis was performed using ultra-performance liquid chromatography quadrupole time-of-flight tandem mass spectrometry and multivariate statistical analysis was employed to study 60 patients with or without ischemic stroke (30 cases and 30 controls).

Results

Serum metabolic profiling identified a series of 12 metabolites with significant alterations, and the related metabolic pathways involved glycerophospholipid, sphingolipid, phospholipid, fat acid, acylcarnitine, heme, and purine metabolism. Subsequently, multiple logistic regression analyses of these metabolites showed uric acid, sphinganine and adrenoyl ethanolamide were potential biomarkers of ischemic stroke with an area under the receiver operating characteristic curve of 0.941.

Conclusions

These findings provide insights into the early diagnosis and potential pathophysiology of ischemic stroke.

Metabolic pathways of oleic and palmitic acid are intensified in PCOS patients with normal androgen levels

CONTEXT

The aetiology and pathogenesis polycystic ovary syndrome (PCOS) remain uncertain and thus the relative studies are still crucial.

OBJECTIVE

Our aim was to analyse the fatty acids profiles of the main phospholipids species in serum from women with PCOS classified into phenotypes, and to diagnose women more susceptible to the occurrence of inflammatory state.

DESIGN

PCOS screening tests were performed in The Clinic of Gynecology and Urogynecology of Pomeranian Medical University in the 2014-2015 years.

SETTING

The study are designed for general community and a primary care or referral center.

PATIENTS

39 patients with PCOS, diagnosed according to Rotterdam's criteria, and 14 healthy women, as a control group, participated in this study. Fatty acid profiles were investigated using gas chromatography. A total of 36 fatty acids and their derivatives were identified and quantified.

MAIN OUTCOME MEASURE

Changes in fatty acids profile in plasma from women with PCOS phenotypes are not identical.

RESULTS

The analyses showed lowered level of total SFA, increase in the concentration of caprylic acid and the activation of palmitic and oleic acids pathways. The level of nervonic acid was several times higher than in the control group, and the levels of behenic and tricosanoic acids were reduced.

CONCLUSIONS

In both phenotypes the alternative metabolic pathways of oleic acid were activated, but they were more pronounced in women with proper level of androgens. Gamma-linolenic acid (C18:3n6) can be a factor protecting hyperandrogenic women.

Impact of a cafeteria diet and daily physical training on the rat serum metabolome

Regular physical activity and healthy dietary patterns are commonly recommended for the prevention and treatment of metabolic syndrome (MetS), which is diagnosed at an alarmingly increasing rate, especially among adolescents. Nevertheless, little is known regarding the relevance of physical exercise on the modulation of the metabolome in healthy people and those with MetS. We have previously shown that treadmill exercise ameliorated different symptoms of MetS. The aim of this study was to investigate the impact of a MetS-inducing diet and different intensities of aerobic training on the overall serum metabolome of adolescent rats. For 8 weeks, young rats were fed either standard chow (ST) or cafeteria diet (CAF) and were subjected to a daily program of training on a treadmill at different speeds. Non-targeted metabolomics was used to identify changes in circulating metabolites, and a combination of multivariate analysis techniques was implemented to achieve a holistic understanding of the metabolome. Among all the identified circulating metabolites influenced by CAF, lysophosphatidylcholines were the most represented family. Serum sphingolipids, bile acids, acylcarnitines, unsaturated fatty acids and vitamin E and A derivatives also changed significantly in CAF-fed rats. These findings suggest that an enduring systemic inflammatory state is induced by CAF. The impact of physical training on the metabolome was less striking than the impact of diet and mainly altered circulating bile acids and glycerophospholipids. Furthermore, the serum levels of monocyte chemoattractant protein-1 were increased in CAF-fed rats, and C-reactive protein was decreased in trained groups. The leptin/adiponectin ratio, a useful marker of MetS, was increased in CAF groups, but decreased in proportion to training intensity. Multivariate analysis revealed that ST-fed animals were more susceptible to exercise-induced changes in metabolites than animals with MetS, in which moderate-intensity seems more effective than high-intensity training. Our results indicate that CAF has a strong negative impact on the metabolome of animals that is difficult to reverse by daily exercise.

Emerging role and recent applications of metabolomics biomarkers in obesity disease research

Metabolomics is a promising approach for the identification of metabolites which serve for early diagnosis, prediction of therapeutic response and prognosis of disease.