Metabolomic profiling with NMR discriminates between biphosphonate and doxorubicin effects on B16 melanoma cells

1 - ArticleThe metabolomic profiles of B16 melanoma cells were investigated in vitro with high resolution-magic angle spinning proton magnetic resonance spectroscopy and OPLS multivariate statistical analyse We compared the profiles for untreated melanoma B16-F10 cells and Ca(2+) chelating EGTA, doxorubicin or BP7033 bisphosphonate treated cells The two last molecules are known to induce anti proliferative effects by different mechanisms of action in cells Untreated and EGTA treated cells had similar profiles and were considered together as control cells Several spectral regions could discriminate control from doxorubicin as well as BP7033 treated cells Doxorubicin and BP7033 displayed distinct metabolic profiles Important changes in neutral lipids and inositol were related to doxorubicin activity whereas BP7033 affected essentially phospholipids and alanine/lactate metabolism These results provide new putative targets for both drugs Metabolomics by NMR is shown here to be a good tool for the investigation of the mechanisms of action of drugs in pre clinical studie

Metabolomic approach by (1)h NMR spectroscopy of serum for the assessment of chronic liver failure in patients with cirrhosis

1 - ArticleAssessment of chronic liver failure (CLF) in cirrhotic patients is needed to make therapeutic decisions. A biological score is usually performed, using the Model for End-Stage Liver Disease (MELD), to evaluate CLF. Nevertheless, MELD does not take into account metabolic perturbations produced by liver-function impairment. In contrast, metabolomics can investigate many metabolic perturbations within biological systems. The purpose of this study was to assess whether metabolomic profiles of serum, obtained by proton NMR spectroscopy from cirrhotic patients, are affected by the severity of CLF. An orthogonal projection to latent-structure analysis was performed to compare MELD scores and NMR spectra of 124 patients with cirrhosis. The statistical model obtained showed a good explained variance (R(2)X = 0.87 and R(2)Y = 0.86) and a good predictability (Q(2)Y = 0.64). Metabolomic profiles showed significant differences regarding various metabolites depending of severity of CLF: levels of high-density lipoprotein and phosphocholine resonances were significantly higher in patients with mild CLF compared to severe CLF. Other metabolites such as lactate, pyruvate, glucose, amino acids, and creatinine were significantly higher in patients with severe CLF than mild CLF. Our conclusion is that metabolomic NMR analysis provides new insights into metabolic processes related to the severity of hepatic function impairment in cirrhosis

Metabolic profiling strategy of caenorhabditis elegans by whole-organism nuclear magnetic resonance

1 - ArticleIn this study, we present a methodology for metabotyping of C. elegans using H-1 high resolution magic angle spinning (HRMAS) whole-organism nuclear magnetic resonance (NMR). We demonstrate and characterize the robustness of our metabolic phenotyping method, discriminating wild-type N2 from mutant sod-1(tm776) animals, with the latter being an otherwise silent mutation, and we identify and quantify several confounding effects to establish guidelines to ensure optimal quality of the raw data across time and space. We monitor the sample stability under experimental conditions and examine variations arising from effects that can potentially confuse the biological interpretation or prevent the automation of the protocol, including sample culture (breeding of the worms by two biologists), sample preparation (freezing), NMR acquisition (acquisition by different spectroscopists, acquisition in different facilities), and the effect of the age of the animals. When working with intact model organisms, some of these exogenous effects are shown to be significant and therefore require control through experimental design and sample randomization

Energetics of endurance exercise in young horses determined by nuclear magnetic resonance metabolomics

International audienceLong-term endurance exercise severely affects metabolism in both human and animal athletes resulting in serious risk of metabolic disorders during or after competition. Young horses (up to 6 years old) can compete in races up to 90 km despite limited scientific knowledge of energetic metabolism responses to long distance exercise in these animals. The hypothesis of this study was that there would be a strong effect of endurance exercise on the metabolomic profiles of young horses and that the energetic metabolism response in young horses would be different from that of more experienced horses. Metabolomic profiling is a powerful method that combines Nuclear Magnetic Resonance (NMR) spectrometry with supervised Orthogonal Projection on Latent Structure (OPLS) statistical analysis. (1)H-NMR spectra were obtained from plasma samples drawn from young horses (before and after competition). The spectra obtained before and after the race from the same horse (92 samples) were compared using OPLS. The statistical parameters showed the robustness of the model (R2Y = 0.947, Q2Y = 0.856 and cros-validated ANOVA p < 0.001). For confirmation of the predictive value of the model, a test set of 104 sample spectra were projected by the model, which provided perfect predictions as the area under the receiving-operator curve was 1. The metabolomic profile determined with the OPLS model showed that glycemia after the race was lower than glycemia before the race, despite the involvement of lipid and protein catabolism. An OPLS model was calculated to compare spectra obtained on plasma taken after the race from 6-year-old horses and from experienced horses (cross-validated ANOVA p < 0.001). The comparison of metabolomic profiles in young horses to those from experienced horses showed that experienced horses maintained their glycemia with higher levels of lactate and a decrease of plasma lipids after the race

The impact of moderate altitude on exercise metabolism in recreational sportsmen: a nuclear magnetic resonance metabolomic approach

Although it is known that altitude impairs performance in endurance sports, there is no consensus on the involvement of energy substrates in this process. The objective of the present study was to determine whether the metabolomic pathways used during endurance exercise differ according to whether the effort is performed at SL or at moderate ALT (at the same exercise intensity, using proton nuclear magnetic resonance, 1H NMR). Twenty subjects performed two 60-min endurance exercise tests at sea level and at 2150 m at identical relative intensity on a cycle ergometer. Blood plasma was obtained from venous blood samples drawn before and after exercise. Proton NMR spectral analysis was then performed on the plasma samples. A multivariate statistical technique was applied to the NMR data. The respective relative intensities of the sea level and altitude endurance tests were essentially the same when expressed as a percentage of the VO2max measured during the corresponding incremental maximal exercise test. Lipid use was similar at sea level and at altitude. In the plasma, levels of glucose, glutamine, alanine and branched-chain amino acids had decreased after exercise at altitude but not after exercise at sea level. The decrease in plasma glucose and free amino acid levels observed after exercise at altitude indicated that increased involvement of the protein pathway was necessary but not sufficient for the maintenance of glycaemia. Metabolomics is a powerful means of gaining insight into the metabolic changes induced by exercise at altitude.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Use of nuclear magnetic resonance spectroscopy to assess renal dysfunction after hypertonic-hyperoncotic resuscitation in rats

1 - ArticleBackground. The aim of this study was to evaluate the renal tolerance of a hypertonic-hyperoncotic solution (HHS) administration during uncontrolled hemorrhagic shock (UHS). Methods: UHS was produced in rats by a preliminary bleed followed by tail amputation. Hydroxyethylstarch (HHS) 200/0.5 6% in NaCl 7.2% was administered to the HHS groups (n = 20) and normal saline (NS) to the NS group (n = 20). Infusion rates were adjusted to prevent mean arterial pressure (MAP) from falling either below 40 mm Hg in the HHS40 (n = 10) and NS40 groups (n = 10), or below 80 mm Hg in the HHS80 (n = 10) and NS80 groups (n = 10). Data obtained were compared with a sham group and a no resuscitation (NR) group. Nephrotoxicity was evaluated by nuclear magnetic resonance analysis in urine samples. Results: Survival was 60% in the NS40 group and 40% in the NS80 group, 70% in the HHS40 group, and 60% in the HHS80 group (p = not significant). Within and between target groups of 40 mm Hg MAP and 80 mm Hg MAP, there was no significant difference in survival. The mean values of renal metabolites to creatinine (ct) ratios were not significantly different among the six groups. Principal component analysis showed that the HHS80 group was characterized by an increase in allantoin/ct and urea/ct ratios demonstrating acute renal dysfunction and failure of nitrogen metabolism. Conclusions:. In prolonged UHS, an infusion of HHS may not increase the rate of survival. HHS infusion in normotensive resuscitation appears to be associated with renal toxicity

Identification of serum proton NMR metabolomic fingerprints associated with hepatocellular carcinoma in patients with alcoholic cirrhosis

International audiencePurpose Metabolomics depicts metabolic changes in biologic systems using a multiparametric analysis technique. This study assessed the metabolomic profiles of serum, obtained by proton nuclear magnetic resonance (NMR) spectroscopy, from cirrhotic patients with and without hepatocellular carcinoma (HCC). Experimental Design The study included 154 consecutive patients with compensated biopsy-proven alcoholic cirrhosis. Among these, 93 had cirrhosis without HCC, 28 had biopsy-proven HCC within the Milan criteria and were eligible for curative treatment (small HCC), and 33 had HCC outside the Milan criteria (large HCC). Proton spectra were acquired at 500 MHz. An orthogonal partial latent structure [orthogonal projection to latent structure (OPLS)] analysis model was built to discriminate large HCC spectra from cirrhotic spectra. Small HCC spectra were secondarily projected using previously built OPLS discriminant components. Results The OPLS model showed discrimination between cirrhotic and large HCC spectra. Metabolites that significantly increased with large HCC were glutamate, acetate, and N-acetyl glycoproteins, whereas metabolites that correlated with cirrhosis were lipids and glutamine. Projection of small HCC samples into the OPLS model showed a heterogeneous distribution between large HCC and cirrhotic samples. Small HCC patients with metabolomic profile similar to those of large HCC group had higher incidences of recurrence or death during follow-up. Conclusions Serum NMR-based metabolomics identified metabolic fingerprints that could be specific to large HCC in cirrhotic livers. From a metabolomic standpoint, some patients with small HCC, who are eligible for curative treatments, seem to behave as patients with advanced cancerous disease. It would be useful to further prospectively investigate these patients to define a subgroup with a worse prognosis. ©2012 AACR

Preliminary Modelling of Ship Manoeuvring in Ice Using a PMM

The Institute for Ocean Technology (IOT) of the National Research Council of Canada (http://www.iot-ito.nrc-cnrc.gc.ca/) has conducted physical, numerical and mathematical modeling of ship manoeuvring characteristics in ice, as part of a larger effort to develop reliable modeling techniques to assist in the design of new ice-worthy vessels and in the simulation of their navigating characteristics. This report presents results from a preliminary series of physical and mathematical modeling of the problem. The report focuses on the interaction processes and the influence of ship motions on the yaw moment exerted on the ship hull. The dominant ice-ship interaction processes are identified. The results show a large influence of ship motions and interaction geometry on the measured yaw moments. The geometrical aspect of the interaction processes is described and its influences on ice loads are discussed. Conclusions are made and recommendations for future works are provided.NRC publication: Ye

NMR Metabolomics Protocols for Drug Discovery

Drug discovery is an extremely difficult and challenging endeavor with a very high failure rate. The task of identifying a drug that is safe, selective and effective is a daunting proposition because disease biology is complex and highly variable across patients. Metabolomics enables the discovery of disease biomarkers, which provides insights into the molecular and metabolic basis of disease and may be used to assess treatment prognosis and outcome. In this regard, metabolomics has evolved to become an important component of the drug discovery process to resolve efficacy and toxicity issues, and as a tool for precision medicine. A detailed description of an experimental protocol is presented that outlines the application of NMR metabolomics to the drug discovery pipeline. This includes: (1) target identification by understanding the metabolic dysregulation in diseases, (2) predicting the mechanism of action of newly discovered or existing drug therapies, (3) and using metabolomics to screen a chemical lead to assess biological activity. Unlike other OMICS approaches, the metabolome is “fragile”, and may be negatively impacted by improper sample collection, storage and extraction procedures. Similarly, biologically-irrelevant conclusions may result from incorrect data collection, pre-processing or processing procedures, or the erroneous use of univariate and multivariate statistical methods. These critical concerns are also addressed in the protocol