Aspartate metabolism and pyruvate homeostasis triggered by oxidative stress in Pseudomonas fluorescens : a functional metabolomic study
Abstract There is mounting evidence that metabolic reprogramming is critical for the survival of organisms exposed to changing and stressed environments. Using the soil microbe Pseudomonas fluorescens as a model system, we demonstrate that the metabolic networks aimed at the conversion of aspartate into pyruvate are enhanced in the presence of hydrogen peroxide (H2O2). The metabolites pyruvate, oxaloacetate and acetate were increased in the treated cultures as measured by HPLC. Enzymes such as aspartate transaminase and phosphoenolpyruvate carboxylase (PEPC) that mediate the conversion of aspartate to phosphoenolp...
Source: Metabolomics - August 1, 2015 Category: Biology Source Type: research

Projected Orthogonalized CHemical Encounter MONitoring (POCHEMON) for microbial interactions in co-culture
Abstract Micro-organismal interspecies competition induces highly complex ecological interactions. Its associated biochemistry is an extremely rich source for bioactive molecules, that can be evaluated by comparing assays of separated species to ‘co-cultures’ in which they compete. The untargeted view that metabolomics provides, gives unprecedented insight into the wealth of involved metabolites. Currently used multivariate data analysis methods in metabolomics, like principal component analysis, do not focus upon up- and down-regulation of constitutive metabolite pools during competition. This severe...
Source: Metabolomics - June 30, 2015 Category: Biology Source Type: research

Metabolomics as a tool for diagnosis and monitoring in coeliac disease
Abstract Coeliac disease (CD) is a well defined condition contributed to by both genetic and environmental factors. The clinical management of CD is becoming increasingly complex as the disparity between symptoms, biological markers and mucosal pathology becomes more apparent. The only available treatment for CD is a life-long strict gluten-free diet (GFD), but up to 86 % of adult patients fail to achieve complete mucosal recovery even after 2 years of a GFD. The only accurate means of monitoring recovery on a GFD is via histology, which is cumbersome and resource intensive. Therefore, there is a need f...
Source: Metabolomics - June 30, 2015 Category: Biology Source Type: research

A hypothetical astrocyte–microglia lactate shuttle derived from a 1 H NMR metabolomics analysis of cerebrospinal fluid from a cohort of South African children with tuberculous meningitis
In this study a proton magnetic resonance (1H NMR)-based metabolomics analysis and several chemometric methods were applied to data generated from lumber cerebrospinal fluid (CSF) samples from three experimental groups: (1) South African infants and children with confirmed TBM, (2) non-meningitis South African infants and children as controls, and (3) neurological controls from the Netherlands. A total of 16 NMR-derived CSF metabolites were identified, which clearly differentiated between the controls and TBM cases under investigation. The defining metabolites were the combination of perturbed glucose and highly elevated l...
Source: Metabolomics - June 30, 2015 Category: Biology Source Type: research

Untargeted metabolomics studies employing NMR and LC–MS reveal metabolic coupling between Nanoarcheum equitans and its archaeal host Ignicoccus hospitalis
Abstract Interspecies interactions are the basis of microbial community formation and infectious diseases. Systems biology enables the construction of complex models describing such interactions, leading to a better understanding of disease states and communities. However, before interactions between complex organisms can be understood, metabolic and energetic implications of simpler real-world host-microbe systems must be worked out. To this effect, untargeted metabolomics experiments were conducted and integrated with proteomics data to characterize key molecular-level interactions between two hyperthermophilic...
Source: Metabolomics - June 30, 2015 Category: Biology Source Type: research

Metabolomics reveals differential metabolic adjustments of normal and overweight subjects during overfeeding
This study is one of the first to describe the metabolic trajectories that differentiate the responses of overweight (OW) from lean individuals during weight gain. Nineteen lean and 19 OW male volunteers were submitted to moderate weight gain using a lipid-enriched overfeeding protocol designed to add about 3,300 kJ per day in excess to their usual diet. Metabolic explorations in combination with plasma and urine metabolomic profiles using liquid chromatography coupled with mass spectrometry were determined along 8 weeks to compare metabolic trajectories and determine early changes in metabolic processes after id...
Source: Metabolomics - June 30, 2015 Category: Biology Source Type: research

A metabolomics approach shows that catechin-enriched green tea attenuates ultraviolet B-induced skin metabolite alterations in mice
In this study, catechin-enriched green tea (CGT) administration significantly attenuated ultraviolet (UV) B-induced mouse skin alterations, i.e., increases in wrinkle formation, thickness, erythema, and transepidermal water loss, and decreases in hydration, elasticity, and collagen fiber content. The metabolites in the mouse skin after UVB irradiation and CGT administration were profiled using comprehensive MS-based metabolomics techniques such as ultra-performance liquid chromatography-quadrupole time-of-flight-mass spectrometry (TOF-MS), gas chromatography-TOF-MS, and NanoMate tandem-MS. From these analysis, we revel tha...
Source: Metabolomics - June 30, 2015 Category: Biology Source Type: research

Comprehensive VOC profiling of an apple germplasm collection by PTR-ToF-MS
Abstract Fruit quality is generally represented by several components, among which aroma plays a fundamental role in determining the overall appreciation. To generate a comprehensive data inventory of aroma compounds in apple, a large collection represented by 190 apple accessions was characterized by a proton transfer reaction-time of flight-mass spectrometry (PTR-ToF-MS) instrument, a valid alternative to a gas chromatography-mass spectrometry (GS-MS) apparatus. The analytical performance of this instrument allowed to profile volatile organic compound (VOC) spectra of a portion of apple fruit flesh in a short t...
Source: Metabolomics - June 30, 2015 Category: Biology Source Type: research

Postprandial metabolic events in mini-pigs: new insights from a combined approach using plasma metabolomics, tissue gene expression, and enzyme activity
Abstract To unravel metabolic adaptations preceding the occurrence of metabolic dysregulations, a nutritional challenge appears as the best tool capable to reveal metabolic disturbances compared to single-point measurements at the static fasting (PA) state. The aim of the present work was to study the metabolic trajectories at the postprandial (PP) state in a relevant human nutrition animal model combining plasma metabolome analysis with classical metabolism exploration tools. In a first trial, three mini pigs were fed a test meal and arterial blood samples withdrawn before and over 4 h following the meal fo...
Source: Metabolomics - June 30, 2015 Category: Biology Source Type: research

Standardizing the experimental conditions for using urine in NMR-based metabolomic studies with a particular focus on diagnostic studies: a review
Abstract The metabolic composition of human biofluids can provide important diagnostic and prognostic information. Among the biofluids most commonly analyzed in metabolomic studies, urine appears to be particularly useful. It is abundant, readily available, easily stored and can be collected by simple, noninvasive techniques. Moreover, given its chemical complexity, urine is particularly rich in potential disease biomarkers. This makes it an ideal biofluid for detecting or monitoring disease processes. Among the metabolomic tools available for urine analysis, NMR spectroscopy has proven to be particularly well-su...
Source: Metabolomics - June 30, 2015 Category: Biology Source Type: research

Can we trust untargeted metabolomics? Results of the metabo-ring initiative, a large-scale, multi-instrument inter-laboratory study
In conclusion, untargeted metabolomics analyses report consistent information within and across instruments of various technologies, even without prior standardisation. (Source: Metabolomics)
Source: Metabolomics - June 30, 2015 Category: Biology Source Type: research

Embedding standards in metabolomics: the Metabolomics Society data standards task group
(Source: Metabolomics)
Source: Metabolomics - June 30, 2015 Category: Biology Source Type: research

Identification of the 12-oxojasmonoyl-isoleucine, a new intermediate of jasmonate metabolism in Arabidopsis, by combining chemical derivatization and LC–MS/MS analysis
This study illustrates the underestimated potential of chemical derivatization for rapid metabolite identification in modern metabolomics and enriches our knowledge of the jasmonates family. (Source: Metabolomics)
Source: Metabolomics - June 30, 2015 Category: Biology Source Type: research

One minute with the Metabolomics Society’s Honorary Fellows 2015
(Source: Metabolomics)
Source: Metabolomics - June 30, 2015 Category: Biology Source Type: research

Off-line two-dimensional liquid chromatography for metabolomics: an example using Agaricus bisporus mushrooms exposed to UV irradiation
Abstract It has previously been shown that irradiation with UV light increases the vitamin D content of certain mushroom species, but the effect on other nutrients is unknown, and is difficult to assess due to the complexity of the sample matrix. Here, an offline reversed phase × reversed phase two-dimensional liquid chromatography methodology was developed and applied to Agaricus bisporus mushrooms in order to demonstrate the potential of the technique and assess the effect of UV irradiation on the mushroom’s metabolic profile. The method allowed the detection of 158 peaks in a single analy...
Source: Metabolomics - June 30, 2015 Category: Biology Source Type: research

Training needs in metabolomics
(Source: Metabolomics)
Source: Metabolomics - June 30, 2015 Category: Biology Source Type: research

Temporal metabolomic responses of cultured HepG2 liver cells to high fructose and high glucose exposures
Abstract High fructose consumption has been implicated with deleterious effects on human health, including hyperlipidemia elicited through de novo lipogenesis. However, more global effects of fructose on cellular metabolism have not been elucidated. In order to explore the metabolic impact of fructose-containing nutrients, we applied both GC-TOF and HILIC-QTOF mass spectrometry metabolomic strategies using extracts from cultured HepG2 cells exposed to fructose, glucose, or fructose + glucose. Cellular responses were analyzed in a time-dependent manner, incubated in media containing 5.5 mM glucose&n...
Source: Metabolomics - May 11, 2015 Category: Biology Source Type: research

Metabolomic and proteomic analysis of breast cancer patient samples suggests that glutamate and 12-HETE in combination with CA15-3 may be useful biomarkers reflecting tumour burden
Abstract Evaluation of protein and metabolite expression patterns in blood using mass spectrometry and high-throughput antibody-based screening platforms has potential for the discovery of new biomarkers for managing breast cancer patient treatment. Previously identified blood-based breast cancer biomarkers, including cancer antigen 15.3 (CA15-3) are useful in combination with imaging (computed tomography scans, magnetic resonance imaging, X-rays) and physical examination for monitoring tumour burden in advanced breast cancer patients. However, these biomarkers suffer from insufficient levels of accuracy and with...
Source: Metabolomics - May 11, 2015 Category: Biology Source Type: research

Metabolic fate of fructose in human adipocytes: a targeted 13 C tracer fate association study
This study demonstrated that fructose stimulates anabolic processes in adipocytes robustly, including glutamate and de novo fatty acid synthesis. Furthermore, fructose also augments the release of free palmitate from fully differentiated adipocytes. These results imply that in the presence of fructose, the metabolic response of adipocytes in culture is altered in a dose dependent manner, particularly favoring increased glutamate and fatty acid synthesis and release, warranting further in vivo studies. (Source: Metabolomics)
Source: Metabolomics - May 11, 2015 Category: Biology Source Type: research

Metabolic transformation of breast cancer in a MCF-7 xenograft mouse model and inhibitory effect of volatile oil from Saussurea lappa Decne treatment
Abstract Breast cancer results from multi-step carcinogenesis, and the transforming process from normal to malignant cells is associated with profound metabolic disturbances. The metabolic transformation due to interplay between tumor and host during the development of breast cancer and its implications for breast cancer therapy have not been extensively investigated. Here, we report a metabonomic study on MCF-7 xenograft mice to delineate characteristic metabolic transformation during the development of breast cancer using a comprehensive two-dimensional gas chromatography–time-of-flight mass spectrometry ...
Source: Metabolomics - May 11, 2015 Category: Biology Source Type: research

The influence of scaling metabolomics data on model classification accuracy
Abstract Correctly measured classification accuracy is an important aspect not only to classify pre-designated classes such as disease versus control properly, but also to ensure that the biological question can be answered competently. We recognised that there has been minimal investigation of pre-treatment methods and its influence on classification accuracy within the metabolomics literature. The standard approach to pre-treatment prior to classification modelling often incorporates the use of methods such as autoscaling, which positions all variables on a comparable scale thus allowing one to achieve separati...
Source: Metabolomics - May 11, 2015 Category: Biology Source Type: research

Metabolomics analysis reveals insights into biochemical mechanisms of mental stress-induced left ventricular dysfunction
Abstract Mental stress induced left ventricular dysfunction (LVD) has been associated with a greater risk of adverse events in coronary heart disease (CHD) patients independent of conventional risk indicators. The underlying biochemical mechanisms of this cardiovascular condition are poorly understood. Our objective was to use metabolomics technology to identify biochemical changes that co-occur with mental stress-induced LVD in patients with clinically stable CHD. Participants were adult CHD patients who were recruited for mental stress-induced myocardial ischemia screening. For this study, we randomly selected ...
Source: Metabolomics - May 11, 2015 Category: Biology Source Type: research

Correction of precursor and product ion relative abundances in order to standardize CID spectra and improve Ecom 50 accuracy for non-targeted metabolomics
Abstract Quantitative biases in the abundance of precursor and product ions due to mass discrimination in RF-only ion guides results in inaccurate collision induced dissociation (CID) spectra. We evaluated the effects of collision cell RF voltage and collision energy on CID spectra using ten singly protonated compounds (46–854 Da) in an orthogonal acceleration time-of-flight mass spectrometer. The relative ion transfer efficiency, i.e. the relative amount of ions transferred through the ion guide at any particular RF voltage was shown to be dependent on the ion’s m/z. We developed an algorith...
Source: Metabolomics - May 11, 2015 Category: Biology Source Type: research

Integration of untargeted metabolomics with transcriptomics reveals active metabolic pathways
We present an analytical strategy that uses data obtained from high resolution liquid chromatography–mass spectrometry and a bioinformatics toolset for detecting actively changing metabolic pathways upon external perturbation. We begin with untargeted metabolite profiling to nominate altered metabolites and identify pathway candidates, followed by validation of those pathways with transcriptomics. Using the model organisms Rhodospirillum rubrum and Bacillus subtilis, our results reveal metabolic pathways that are interconnected with methionine salvage. The rubrum-type methionine salvage pathway is interconnected with...
Source: Metabolomics - May 11, 2015 Category: Biology Source Type: research

MarVis-Pathway: integrative and exploratory pathway analysis of non-targeted metabolomics data
Abstract A central aim in the evaluation of non-targeted metabolomics data is the detection of intensity patterns that differ between experimental conditions as well as the identification of the underlying metabolites and their association with metabolic pathways. In this context, the identification of metabolites based on non-targeted mass spectrometry data is a major bottleneck. In many applications, this identification needs to be guided by expert knowledge and interactive tools for exploratory data analysis can significantly support this process. Additionally, the integration of data from other omics platform...
Source: Metabolomics - May 11, 2015 Category: Biology Source Type: research

Predicting retention time in hydrophilic interaction liquid chromatography mass spectrometry and its use for peak annotation in metabolomics
Abstract Liquid chromatography coupled to mass spectrometry (LCMS) is widely used in metabolomics due to its sensitivity, reproducibility, speed and versatility. Metabolites are detected as peaks which are characterised by mass-over-charge ratio (m/z) and retention time (rt), and one of the most critical but also the most challenging tasks in metabolomics is to annotate the large number of peaks detected in biological samples. Accurate m/z measurements enable the prediction of molecular formulae which provide clues to the chemical identity of peaks, but often a number of metabolites have identical molecular formu...
Source: Metabolomics - May 11, 2015 Category: Biology Source Type: research

A metabolomics approach to unravel the regulating role of phytohormones towards carotenoid metabolism in tomato fruit
This study aimed at deepening the knowledge on the regulatory role of phytohormones in carotenoid metabolism. More specifically, it was envisaged to reveal the phytohormones involved in the metabolism of α-carotene, β-carotene, lycopene, lutein and zeaxanthin. To this purpose, the phytohormone profiles of 50 tomato fruits were determined by high-resolution Orbitrap mass spectrometry and evaluated towards the associated carotenoid levels. Data mining was performed by differential expression and orthogonal partial least squares analyses. This metabolomics approach revealed 5 phytohormonal metabolites, which signif...
Source: Metabolomics - May 11, 2015 Category: Biology Source Type: research

A pilot study of the onset of hepatic encephalopathy (OHE) in mice induced by thioacetamide and the protective effect of taurine by holistic metabolic characterization
Abstract Hepatic encephalopathy (HE) is a severe neuropsychiatric complication due to acute or chronic liver failure. In this work, an acute thioacetamide induced HE mice model was established to investigate the metabolic events in the onset of HE (OHE) and the protective role of taurine (TAU). Sera for biochemical evaluation, and livers and cortexes for histopathological inspection and NMR-based metabolomic investigation were collected. Principal component analysis and orthogonal partial least squares-discriminant analysis were performed to excavate differential metabolites of OHE, and explore the protective rol...
Source: Metabolomics - May 11, 2015 Category: Biology Source Type: research

GC–MS based targeted metabolic profiling identifies changes in the wheat metabolome following deoxynivalenol treatment
In this study we established a targeted GC–MS based metabolomics workflow comprising a standardized experimental setup for growth, treatment and sampling of wheat ears and subsequent GC–MS analysis followed by data processing and evaluation of QC measures using tailored statistical and bioinformatics tools. This workflow was applied to wheat samples of six genotypes with varying levels of Fusarium resistance, treated with either DON or water, and harvested 0, 12, 24, 48 and 96 h after treatment. The results suggest that the primary carbohydrate metabolism and transport, the citric acid cycle and the primar...
Source: Metabolomics - May 11, 2015 Category: Biology Source Type: research

Controlling the quality of metabolomics data: new strategies to get the best out of the QC sample
Abstract The type and use of quality control (QC) samples is a ‘hot topic’ in metabolomics. QCs are not novel in analytical chemistry; however since the evolution of using QCs to control the quality of data in large scale metabolomics studies (first described in 2011), the need for detailed knowledge of how to use QCs and the effects they can have on data treatment is growing. A controlled experiment has been designed to illustrate the most advantageous uses of QCs in metabolomics experiments. For this, samples were formed from a pool of plasma whereby different metabolites were spiked into two groups...
Source: Metabolomics - May 11, 2015 Category: Biology Source Type: research

Prediction of intracellular metabolic states from extracellular metabolomic data
Abstract Metabolic models can provide a mechanistic framework to analyze information-rich omics data sets, and are increasingly being used to investigate metabolic alternations in human diseases. An expression of the altered metabolic pathway utilization is the selection of metabolites consumed and released by cells. However, methods for the inference of intracellular metabolic states from extracellular measurements in the context of metabolic models remain underdeveloped compared to methods for other omics data. Herein, we describe a workflow for such an integrative analysis emphasizing on extracellular metabolo...
Source: Metabolomics - May 11, 2015 Category: Biology Source Type: research

Phytochemical distinction between Pelargonium sidoides (“Umckaloabo”) and P.   reniforme through 1 H-NMR and UHPLC–MS metabolomic profiling
Abstract Two Pelargonium species which are indigenous to South Africa; P. sidoides DC and P. reniforme Curt., are highly valued traditional remedies used primarily for the treatment of upper respiratory tract infections. The ethnobotanical value of P. sidoides has led to the commercialisation of herbal medicinal products such as Umckaloabo® that are marketed internationally. Although the two species can be distinguished by leaf shape and flower colour, the rhizomes which are used for preparation of the commercial extracts are morphologically similar. Non-targeted 1H-NMR and UHPLC–MS metab...
Source: Metabolomics - May 11, 2015 Category: Biology Source Type: research

Longitudinal evaluation of salivary profile from children with dental caries before and after treatment
Abstract Saliva is a biofluid largely used in metabolomics for the assessment of local and systemic diseases. Our group has previously demonstrated the salivary metabolomic signature of children with dental caries (Fidalgo et al. Metabolomics 9(3):657–666, 2013). The aim of the current study was investigation, using NMR spectroscopy, of the changes observed for metabolite markers for caries lesions before and after dental treatment. Saliva from children with and without dental caries before and after treatment was analyzed by NMR. Partial least squared discriminant analysis (PLS-DA) conducted on the spe...
Source: Metabolomics - May 11, 2015 Category: Biology Source Type: research

Lipidomic analysis of plasma samples from women with polycystic ovary syndrome
Abstract Polycystic ovary syndrome (PCOS) is a common disorder affecting between 5 and 18 % of females of reproductive age and can be diagnosed based on a combination of clinical, ultrasound and biochemical features, none of which on its own is diagnostic. A lipidomic approach using liquid chromatography coupled with accurate mass high-resolution mass-spectrometry (LC-HRMS) was used to investigate if there were any differences in plasma lipidomic profiles in women with PCOS compared with control women at different stages of menstrual cycle. Plasma samples from 40 women with PCOS and 40 controls aged betw...
Source: Metabolomics - May 11, 2015 Category: Biology Source Type: research

Comprehensive characterization and evaluation of hepatocellular carcinoma by LC–MS based serum metabolomics
In this study, 587 sera from HCC patients, hepatitis B virus (HBV) infected subjects and healthy control subjects were employed to characterize metabolic alterations using a liquid chromatography tandem mass spectrometry-based metabolomics approach. d-Galactose significantly increased whereas undecanoyl-l-carnitine and PE (P-18:0/0:0) decreased in HCC patients when compared with non-HCC controls (HBVs and NCs). These metabolites were finally identified as independent diagnostic factors for HCC discrimination. The combination of discriminative metabolites and alpha-fetoprotein could also significantly improve the diagnostic...
Source: Metabolomics - April 19, 2015 Category: Biology Source Type: research

Ask not what your Society can do for you, ask what you can do for your Society!
(Source: Metabolomics)
Source: Metabolomics - April 19, 2015 Category: Biology Source Type: research

Functional genomics and metabolomics reveal the toxicological effects of cadmium in Mus musculus mice
Abstract Cadmium (Cd) is an environmental pollutant that accumulates in the organisms causing serious health problems. Over the past decades, omics studies have been conducted trying to elucidate changes in the genome, the transcriptome or the proteome after Cd exposure. Metabolomics is relatively new to the omics revolution, but has shown enormous potential for investigating biological systems or their perturbations. When metabolomic data are interpreted in combination with genomic, transcriptomic and proteomic results, in the so-called systems biology approach, a holistic knowledge of the organism/process under ...
Source: Metabolomics - April 12, 2015 Category: Biology Source Type: research

Metabolomics Society’s International Affiliations
(Source: Metabolomics)
Source: Metabolomics - April 10, 2015 Category: Biology Source Type: research

Exposure to perfluorononanoic acid combined with a low-dose mixture of 14 human-relevant compounds disturbs energy/lipid homeostasis in rats
This study verifies that a chemical mixture given at high-end human exposure levels can affect lipid homeostasis and that the combined use of metabolomics and transcriptomics can provide complimentary information allowing for a detailed analysis of affected signaling pathways. (Source: Metabolomics)
Source: Metabolomics - April 9, 2015 Category: Biology Source Type: research

Sex differences in urine metabolites related with risk of diabetes using NMR spectroscopy: results of the study of health in pomerania
In conclusion, we confirmed the potential of metabolomics to assess the risk of type 2 diabetes and detected pronounced sex differences. Moreover, we demonstrated the practicability of spot urine samples as potential non-invasive diabetes screening approach. (Source: Metabolomics)
Source: Metabolomics - April 2, 2015 Category: Biology Source Type: research

Global profiling of the muscle metabolome: method optimization, validation and application to determine exercise-induced metabolic effects
Abstract Skeletal muscle represents a crucial metabolic organ in the body characterized by a tremendous metabolic plasticity and the ability to influence important metabolic events elsewhere in the body. In order to understand the metabolic implications of skeletal muscle, it is imperative to characterize the metabolites within the tissue itself. In this work we aimed at developing a suitable analytical pipeline to analyze the metabolome of muscle tissue. Methanol/chloroform/water at neutral pH was selected as the method of choice for metabolite extraction prior to analysis by chromatographic-mass spectrometry sy...
Source: Metabolomics - February 27, 2015 Category: Biology Source Type: research

Sparse multi-block PLSR for biomarker discovery when integrating data from LC–MS and NMR metabolomics
The objective of this study was to implement a multivariate method which analyzes multi-block metabolomics data and performs variable selection in order to discover potential biomarkers, simultaneously. We call this method sparse multi-block partial least squares regression (Sparse MBPLSR). To achieve this method, we first defined a nonlinear iterative partial least squares (NIPALS) algorithm for Sparse PLSR, thereafter we extended it to Sparse MBPLSR. Since over-fitting is an issue when variable selection is involved, we implemented a cross model validation (CMV) to assess the reliability and stability of the selecte...
Source: Metabolomics - February 27, 2015 Category: Biology Source Type: research

A workflow for bacterial metabolic fingerprinting and lipid profiling: application to Ciprofloxacin challenged Escherichia coli
Abstract The field of lipidomics focuses upon the non-targeted analysis of lipid composition, the process of which follows similar routines to those applied in conventional metabolic profiling, however lipidomics differs with respect to the sample preparation steps and chosen analytical platform applied to the sample analysis. Conventionally, lipidomics has applied analytical techniques such as direct infusion mass spectrometry and more recently reverse phase liquid chromatography–mass spectrometry, for the detection of mono-, di-, and tri-acyl glycerols, phospholipids, and other complex lipophilic species ...
Source: Metabolomics - February 27, 2015 Category: Biology Source Type: research

Diabetes associated metabolomic perturbations in NOD mice
This study examined the circulating metabolomic profiles of NOD mice progressing or not progressing to T1D. Total beta-cell mass was quantified in the intact pancreas using transgenic NOD mice expressing green fluorescent protein under the control of mouse insulin I promoter. While both progressor and non-progressor animals displayed lymphocyte infiltration and endoplasmic reticulum stress in the pancreas tissue, overt T1D did not develop until animals lost ~70 % of the total beta-cell mass. Gas chromatography time of flight mass spectrometry was used to measure>470 circulating metabolites in male and female progre...
Source: Metabolomics - February 27, 2015 Category: Biology Source Type: research

Metabolomics in non-arteritic anterior ischemic optic neuropathy patients by liquid chromatography–quadrupole time-of-flight mass spectrometry
Abstract Non-Arteritic Anterior Ischemic Optic Neuropathy (NAION) is a rare ischemic disease that affects the optic nerve. Pathophysiology and mechanism of ischemia of NAION remain uncertain, so the aim of this work is to establish the first metabolic fingerprinting of patients with NAION to discover possible new biomarkers. Twenty-four patients, aged 39–85 years, diagnosed with NAION, after a sudden loss of vision, were recruited for the study. Plasma samples of patients and controls were fingerprinted with liquid chromatography coupled to quadrupole time-of-flight by electrospray ionization, and obta...
Source: Metabolomics - February 27, 2015 Category: Biology Source Type: research

Quantitative trait loci analysis to study the genetic regulation of non-polar metabolites in perennial ryegrass
This study is a two-phase experiment in which we have profiled transesterified non-polar metabolites in a Lolium perenne population consisting of parents, F1 and 325 F2 genotypes. These were grown in a replicated field trial, then analysed in batches by a targeted approach using gas-chromatography mass spectrometry (GC–MS), which identified 17 metabolites. The metabolite data was analysed using a mixed model that included random effects of field replicate, laboratory batch and technical replication to derive genotype means for QTL mapping. Using a linkage map of 326 markers, mainly Diversity Array Technology markers,...
Source: Metabolomics - February 27, 2015 Category: Biology Source Type: research

Impact of induced drought stress on the metabolite profiles of barley grain
Abstract The aim of the study was to investigate the impact of drought stress on the metabolite profiles of barley (Hordeum vulgare L.) grain against the background of natural variability depending on growing location and season. Six barley genotypes were field-grown (i) under normal weather conditions at two different sites and (ii) under induced drought conditions, using a Rain-Out-Shelter. Both trials were performed in three consecutive seasons (2010–2012). Samples were subjected to a gas chromatography-mass spectrometry metabolite profiling procedure, based on the extraction and fractionation of a broad...
Source: Metabolomics - February 27, 2015 Category: Biology Source Type: research

Fast sampling for quantitative microbial metabolomics: new aspects on cold methanol quenching: metabolite co-precipitation
We report that the co-precipitation is a hitherto neglected phenomenon and concluded that its degree strongly linked to culturing conditions (i.e. media composition) and chemical properties of the particular metabolite. Thus, intracellular metabolite levels measured from samples collected by cold methanol quenching might be uncertain and variably biased due to corruption by described phenomena. (Source: Metabolomics)
Source: Metabolomics - February 27, 2015 Category: Biology Source Type: research

Parasitoid venom induces metabolic cascades in fly hosts
Abstract Parasitoid wasps inject insect hosts with a cocktail of venoms to manipulate the physiology, development, and immunity of the hosts and to promote development of the parasitoid offspring. The jewel wasp Nasonia vitripennis is a model parasitoid with at least 79 venom proteins. We conducted a high-throughput analysis of Nasonia venom effects on temporal changes of 249 metabolites in pupae of the flesh fly host (Sarcophaga bullata), over a 5-day time course. Our results show that venom does not simply arrest the metabolism of the fly host. Rather, it targets specific metabolic processes while keeping hosts...
Source: Metabolomics - February 27, 2015 Category: Biology Source Type: research

A ‘rule of 0.5’ for the metabolite-likeness of approved pharmaceutical drugs
Abstract We exploit the recent availability of a community reconstruction of the human metabolic network (‘Recon2’) to study how close in structural terms are marketed drugs to the nearest known metabolite(s) that Recon2 contains. While other encodings using different kinds of chemical fingerprints give greater differences, we find using the 166 Public MDL Molecular Access (MACCS) keys that 90 % of marketed drugs have a Tanimoto similarity of more than 0.5 to the (structurally) ‘nearest’ human metabolite. This suggests a ‘rule of 0.5’ mnemonic for assessing the metabolite-...
Source: Metabolomics - February 27, 2015 Category: Biology Source Type: research