PubMed

MCT1 Modulates Cancer Cell Pyruvate Export and Growth of Tumors that Co-express MCT1 and MCT4. Cell Rep. 2016 Feb 10; Authors: Hong CS, Graham NA, Gu W, Espindola Camacho C, Mah V, Maresh EL, Alavi M, Bagryanova L, Krotee PA, Gardner BK, Behbahan IS, Horvath S, Chia D, Mellinghoff IK, Hurvitz SA, Dubinett SM, Critchlow SE, Kurdistani SK, Goodglick L, Braas D, Graeber TG, Christofk HR Abstract Monocarboxylate transporter 1 (MCT1) inhibition is thought to block tumor growth through disruption of lactate transport and glycolysis. Here, we show MCT1 inhibition impairs proliferation of glycolytic breast cancer cells co-expressing MCT1 and MCT4 via disruption of pyruvate rather than lactate export. MCT1 expression is elevated in glycolytic breast tumors, and high MCT1 expression predicts poor prognosis in breast and lung cancer patients. Acute MCT1 inhibition reduces pyruvate export but does not consistently alter lactate transport or glycolytic flux in breast cancer cells that co-express MCT1 and MCT4. Despite the lack of glycolysis impairment, MCT1 loss-of-function decreases breast cancer cell proliferation and blocks growth of mammary fat pad xenograft tumors. Our data suggest MCT1 expression is elevated in glycolytic cancers to promote pyruvate export that when inhibited, enhances oxidative metabolism and reduces proliferation. This study presents an alternative molecular consequence of MCT1 inhibitors, further supporting their use as anti-cancer therapeutics. PMID: 26876179 [PubMed - as supplied by publisher]

A combined non-targeted and targeted metabolomics approach to study the stereoselective metabolism of benalaxyl enantiomers in mouse hepatic microsomes. Environ Pollut. 2016 Feb 10;212:358-365 Authors: Wang X, Wang D, Wang Y, Zhang P, Zhou Z, Zhu W Abstract Understanding of xenobiotic metabolism is necessary for risk assessment as well as toxicological research. In the present study, nanoLC/LTQ-Orbitrap mass based non-targeted metabolomics method coupled with ultra-performance liquid chromatography (UPLC)/triple quadrupole mass based targeted metabolomics method was carried out to investigate the stereoselective metabolism of benalaxyl in mouse hepatic microsomes. As a result, 7 metabolites of benalaxyl were identified, including 5 previously reported and 2 newly identified metabolites in present work. Hydroxylation, oxidation and esterolysis were major biotransformation reactions of benalaxyl in mouse hepatic microsomes. For stereoselective metabolism study, (-)-R-benalaxyl degraded much faster than its antipode with the t1/2 of 81.24 and 190.38 min for (-)-R- and (+)-S-benalaxyl, respectively. More importantly, stereoselectivity was also observed in the formation of the identified metabolites. In conclusion, the combined use of the mass spectrometry based targeted and non-targeted metabolomics provided a new approach to investigate stereoselective metabolism and identify novel metabolites of chiral pesticides. This study highlights the stereoselective metabolic profile of benalaxyl enantiomers and provides reliable data for benalaxyl toxicological risk assessment in mammal. PMID: 26874317 [PubMed - as supplied by publisher]

Lean-seafood intake decreases urinary markers of mitochondrial lipid and energy metabolism in healthy subjects: metabolomics results from a randomized crossover intervention study. Mol Nutr Food Res. 2016 Feb 13; Authors: Schmedes M, Aadland EK, Sundekilde UK, Jacques H, Lavigne C, Graff IE, Eng Ø, Holthe A, Mellgren G, Young JF, Bertram HC, Liaset B, Clausen MR Abstract SCOPE: Proteins constitute an important part of the human diet, but understanding of the effects of different dietary protein sources on human metabolism is sparse. We aimed to elucidate diet-induced metabolic changes through untargeted urinary metabolomics after 4 wks of intervention with lean-seafood or non-seafood diets. METHODS: In a randomized controlled trial with crossover design 20 healthy subjects consumed 2 balanced diets that varied in main protein sources for 4 wks. Morning spot urine samples were collected before and after each intervention period. Untargeted metabolomics based on (1) H NMR spectroscopy and LC-MS analyses were applied to characterize the urinary metabolic response to the interventions. RESULTS: The lean-seafood diet period reduced the urinary level of L-carnitine, 2,6-dimethylheptanoylcarnitine and N-2-pyridone-5-carboxamide (2PY), relative to the non-seafood period. The dietary analysis revealed that the higher urinary level of trimethylamine-N-oxide (TMAO) after the lean-seafood diet period and guanidinoacetate and 3-methylhistidine (3MH) after the non-seafood diet period was related to the endogenous content of these compounds in the diets. CONCLUSIONS: Our data reveal that 4 wks of lean-seafood intake reduces urinary excretion of metabolites involved in mitochondrial lipid and energy metabolism possibly facilitating a higher lipid catabolism in healthy subjects after the lean-seafood intake. This article is protected by copyright. All rights reserved. PMID: 26873789 [PubMed - as supplied by publisher]

The study on serum and urine of renal interstitial fibrosis rats induced by unilateral ureteral obstruction based on metabonomics and network analysis methods. Anal Bioanal Chem. 2016 Feb 12; Authors: Xiang Z, Sun H, Cai X, Chen D Abstract Transmission of biological information is a biochemical process of multistep cascade from genes/proteins to metabolites. However, because most metabolites reflect the terminal information of the biochemical process, it is difficult to describe the transmission process of disease information in terms of the metabolomics strategy. In this paper, by incorporating network and metabolomics methods, an integrated approach was proposed to systematically investigate and explain the molecular mechanism of renal interstitial fibrosis. Through analysis of the network, the cascade transmission process of disease information starting from genes/proteins to metabolites was putatively identified and uncovered. The results indicated that renal fibrosis was involved in metabolic pathways of glycerophospholipid metabolism, biosynthesis of unsaturated fatty acids and arachidonic acid metabolism, riboflavin metabolism, tyrosine metabolism, and sphingolipid metabolism. These pathways involve kidney disease genes such as TGF-β1 and P2RX7. Our results showed that combining metabolomics and network analysis can provide new strategies and ideas for the interpretation of pathogenesis of disease with full consideration of "gene-protein-metabolite." Graphical Abstract ᅟ. PMID: 26873208 [PubMed - as supplied by publisher]

Target-based metabolomics for the quantitative measurement of 37 pathway metabolites in rat brain and serum using hydrophilic interaction ultra-high-performance liquid chromatography-tandem mass spectrometry. Anal Bioanal Chem. 2016 Feb 12; Authors: Chen J, Hou W, Han B, Liu G, Gong J, Li Y, Zhong D, Liao Q, Xie Z Abstract Amino acids, neurotransmitters, purines, and pyrimidines are bioactive molecules that play fundamental roles in maintaining various physiological functions. Their metabolism is closely related to the health, growth, development, reproduction, and homeostasis of organisms. Most recently, comprehensive measurements of these metabolites have shown their potential as innovative approaches in disease surveillance or drug intervention. However, simultaneous measurement of these metabolites presents great difficulties. Here, we report a novel quantitative method that uses hydrophilic interaction ultra-high-performance liquid chromatography-tandem mass spectrometry (HILIC-UPLC-MS/MS), which is highly selective, high throughput, and exhibits better chromatographic behavior than existing methods. The developed method enabled the rapid quantification of 37 metabolites, spanning amino acids, neurotransmitters, purines, and pyrimidines pathways, within 6.5 min. The compounds were separated on an ACQUITY UPLC® BEH Amide column. Serum and brain homogenate were extracted by protein precipitation. The intra- and interday precision of all of the analytes was less than 11.34 %, and the accuracy was between -11.74 and 11.51 % for all quality control (QC) levels. The extraction recoveries of serum ranged from 84.58 % to 116.43 % and those of brain samples from 80.80 % to 119.39 %, while the RSD was 14.61 % or less for all recoveries. This method was used to successfully characterize alterations in the rat brain and, in particular, their dynamics in serum. The following study was performed to simultaneously test global changes of these metabolites in a serotonin antagonist p-chlorophenylalanine (PCPA)-induced anxiety and insomnia rat model to understand the effect and mechanism of PCPA. Taken together, these results show that the method is able to simultaneously monitor a large panel of metabolites and that this protocol may represent a metabolomic method to diagnose toxicological and pathophysiological states. Graphical Abstract Overview of experimental workflow. PMID: 26873199 [PubMed - as supplied by publisher]

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Related Articles Metabolomic and Transcriptomic Comparison of Solid-State and Submerged Fermentation of Penicillium expansum KACC 40815. PLoS One. 2016;11(2):e0149012 Authors: Kim HY, Heo DY, Park HM, Singh D, Lee CH Abstract Penicillium spp. are known to harbor a wide array of secondary metabolites with cryptic bioactivities. However, the metabolomics of these species is not well-understood in terms of different fermentation models and conditions. The present study involved metabolomics profiling and transcriptomic analysis of Penicillium expansum 40815 under solid-state fermentation (SSF) and submerged fermentation (SmF). Metabolite profiling was carried out using ultra-performance liquid chromatography quadruple time-of-flight mass spectrometry with multivariate analysis, followed by transcriptomic analyses of differentially expressed genes. In principal component analysis, the metabolite profiling data was studied under different experimental sets, including SSF and SmF. The significantly different metabolites such as polyketide metabolites (agonodepside B, rotiorin, verrucosidin, and ochrephilone) and corresponding gene transcripts (polyketide synthase, aromatic prenyltransferase, and terpenoid synthase) were primarily detected under SmF conditions. In contrast, the meroterpenoid compounds (andrastin A and C) and their genes transcripts were exclusively detected under SSF conditions. We demonstrated that the metabolite production and its corresponding gene expression levels in P. expansum 40815 were significantly influenced by the varying growth parameters and the immediate environment. This study further provides a foundation to produce specific metabolites by regulating fermentation conditions. PMID: 26863302 [PubMed - as supplied by publisher]

Related Articles Plasma First Resuscitation Reduces Lactate Acidosis, Enhances Redox Homeostasis, Amino Acid and Purine Catabolism in a Rat Model of Profound Hemorrhagic Shock. Shock. 2016 Feb 6; Authors: D'Alessandro A, Moore HB, Moore EE, Wither MJ, Nemkov T, Morton AP, Gonzalez E, Chapman MP, Fragoso M, Slaughter A, Sauaia A, Silliman CC, Hansen KC, Banerjee A Abstract The use of aggressive crystalloid resuscitation to treat hypoxemia, hypovolemia and nutrient deprivation promoted by massive blood loss may lead to the development of the blood vicious cycle of acidosis, hypothermia, and coagulopathy and, utterly, death. Metabolic acidosis is one of the many metabolic derangements triggered by severe trauma/hemorrhagic shock, also including enhanced proteolysis, lipid mobilization, as well as traumatic diabetes. Appreciation of the metabolic benefit of plasma first resuscitation is an important concept. Plasma resuscitation has been shown to correct hyperfibrinolysis secondary to severe hemorrhage better than normal saline. Here we hypothesize that plasma first resuscitation corrects metabolic derangements promoted by severe hemorrhage better than resuscitation with normal saline. Ultra-high-performance liquid chromatography-mass spectrometry-based metabolomics analyses were performed to screen plasma metabolic profiles upon shock and resuscitation with either platelet-free plasma or normal saline in a rat model of severe hemorrhage. Of the 251 metabolites that were monitored, 101 were significantly different in plasma vs normal saline resuscitated rats. Plasma resuscitation corrected lactate acidosis by promoting glutamine/amino acid catabolism and purine salvage reactions. Plasma first resuscitation may benefit critically injured trauma patients by relieving the lactate burden and promoting other non-clinically measured metabolic changes. In the light of our results, we propose that plasma resuscitation may promote fueling of mitochondrial metabolism, through the enhancement of glutaminolysis/amino acid catabolism and purine salvage reactions. The treatment of trauma patients in hemorrhagic shock with plasma first resuscitation is likely not only to improve coagulation, but also to promote substrate-specific metabolic corrections. PMID: 26863033 [PubMed - as supplied by publisher]

Related Articles Adjustments to the preanalytical phase of quantitative cell-free DNA analysis. Data Brief. 2016 Mar;6:326-9 Authors: Bronkhorst AJ, Aucamp J, Pretorius PJ Abstract Evaluating the kinetics of cell-free DNA (cfDNA) in the blood of cancer patients could be a strong auxiliary component to the molecular characterization of cfDNA, but its potential clinical significance is obscured by the absence of an analytical consensus. To utilize quantitative cfDNA assessment with confidence, it is crucial that the preanalytical phase is standardized. In a previous publication, several preanalytical variables that may affect quantitative measurements of cfDNA were identified, and the most confounding variables were assessed further using the growth medium of cultured cancer cells as a source of cfDNA ("Cell-free DNA: Preanalytical variables" [1]). The data accompanying this report relates to these experiments, which includes numerous changes to the sample handling and isolation protocols, and can be used for the interpretation of these results and other similar experiments by different researchers. PMID: 26862578 [PubMed]

Related Articles Short and long term prognosis in perinatal asphyxia: An update. World J Clin Pediatr. 2016 Feb 8;5(1):67-74 Authors: Ahearne CE, Boylan GB, Murray DM Abstract Interruption of blood flow and gas exchange to the fetus in the perinatal period, known as perinatal asphyxia, can, if significant, trigger a cascade of neuronal injury, leading on to neonatal encephalopathy (NE) and resultant long-term damage. While the majority of infants who are exposed to perinatal hypoxia-ischaemia will recover quickly and go on to have a completely normal survival, a proportion will suffer from an evolving clinical encephalopathy termed hypoxic-ischaemic encephalopathy (HIE) or NE if the diagnosis is unclear. Resultant complications of HIE/NE are wide-ranging and may affect the motor, sensory, cognitive and behavioural outcome of the child. The advent of therapeutic hypothermia as a neuroprotective treatment for those with moderate and severe encephalopathy has improved prognosis. Outcome prediction in these infants has changed, but is more important than ever, as hypothermia is a time sensitive intervention, with a very narrow therapeutic window. To identify those who will benefit from current and emerging neuroprotective therapies we must be able to establish the severity of their injury soon after birth. Currently available indicators such as blood biochemistry, clinical examination and electrophysiology are limited. Emerging biological and physiological markers have the potential to improve our ability to select those infants who will benefit most from intervention. Biomarkers identified from work in proteomics, metabolomics and transcriptomics as well as physiological markers such as heart rate variability, EEG analysis and radiological imaging when combined with neuroprotective measures have the potential to improve outcome in HIE/NE. The aim of this review is to give an overview of the literature in regards to short and long-term outcome following perinatal asphyxia, and to discuss the prediction of this outcome in the early hours after birth when intervention is most crucial; looking at both currently available tools and introducing novel markers. PMID: 26862504 [PubMed]

Related Articles Integrating candidate metabolites and biochemical factors to elucidate the action mechanism of Xue-sai-tong injection based on (1)H NMR metabolomics. J Chromatogr B Analyt Technol Biomed Life Sci. 2016 Feb 4; Authors: Jiang M, Zhao X, Wang L, Xu L, Zhang Y, Li Z Abstract A strategy of integrating candidate metabolites with crucial biochemical factors was proposed in this study to discover relevant biological functions for interpreting the action mechanism of Traditional Chinese Medicines (TCM). This approach was applied to Xue-Sai-Tong injection (XST) to reveal the action mechanism based on the metabolic response in an ischemia/reperfusion (I/R) rat model by analyzing NMR profile. Partial least squares discriminate analysis (PLS-DA) was used to compare metabolic profiles of serum samples and revealed nine metabolites altered by I/R injury could be restored to normal status (sham-operated group) under the therapy of XST. The pathway enrichment analysis suggested the metabolic changes were mainly involved in pyruvate metabolism, glycolysis, and citrate cycle. The functional roles of the candidate metabolites were further identified by Pearson correlation analysis with the key biochemical factors in serum. The results indicated pyruvate, succinate, acetate and lysine showed significant associations with the oxidative stress factors. Elevated level of pyruvate was found as an essential metabolic response for the major effect of XST against I/R injury by enhancing glycolysis and overcoming the induced reactive oxygen species (ROS). This metabolomics approach provides a better understanding of the mechanisms of TCM and helps to develop a holistic view of TCM efficacy. PMID: 26862062 [PubMed - as supplied by publisher]

Related Articles Metabolite profiles of diabetes incidence and intervention response in the Diabetes Prevention Program. Diabetes. 2016 Feb 9; Authors: Walford GA, Ma Y, Clish C, Florez JC, Wang TJ, Gerszten RE, Diabetes Prevention Program Research Group Abstract Identifying novel biomarkers of type 2 diabetes risk may improve prediction and prevention among individuals at high risk of the disease and elucidate new biological pathways relevant to diabetes development. We performed plasma metabolite profiling in the Diabetes Prevention Program (DPP), a completed trial that randomized high-risk individuals to lifestyle, metformin, or placebo interventions. Previously reported markers, branched chain and aromatic amino acids and glutamine/glutamate, were associated with incident diabetes (P<0.05 for all), but these associations were attenuated upon adjustment for clinical and biochemical measures. By contrast, baseline levels of betaine (also known as glycine betaine, HR 0.84 per SD log metabolite level, P=0.02) and three other metabolites were associated with incident diabetes even after adjustment. Moreover, betaine was increased by the lifestyle intervention, which was the most effective approach to preventing diabetes, and increases in betaine at 2 years were also associated with lower diabetes incidence (P=0.01). Our findings indicate betaine is a marker of diabetes risk among high-risk individuals both at baseline and during preventive interventions, and complement animal models demonstrating a direct role for betaine in modulating metabolic health. PMID: 26861782 [PubMed - as supplied by publisher]

Related Articles Random Sample Consensus combined with Partial Least Squares regression (RANSAC-PLS) for microbial metabolomics data mining and phenotype improvement. J Biosci Bioeng. 2016 Feb 6; Authors: Teoh ST, Kitamura M, Nakayama Y, Putri S, Mukai Y, Fukusaki E Abstract In recent years, the advent of high-throughput omics technology has made possible a new class of strain engineering approaches, based on identification of possible gene targets for phenotype improvement from omic-level comparison of different strains or growth conditions. Metabolomics, with its focus on the omic level closest to the phenotype, lends itself naturally to this semi-rational methodology. When a quantitative phenotype such as growth rate under stress is considered, regression modeling using multivariate techniques such as partial least squares (PLS) is often used to identify metabolites correlated with the target phenotype. However, linear modeling techniques such as PLS require a consistent metabolite-phenotype trend across the samples, which may not be the case when outliers or multiple conflicting trends are present in the data. To address this, we proposed a data-mining strategy that utilizes random sample consensus (RANSAC) to select subsets of samples with consistent trends for construction of better regression models. By applying a combination of RANSAC and PLS (RANSAC-PLS) to a dataset from a previous study (gas chromatography/mass spectrometry metabolomics data and 1-butanol tolerance of 19 yeast mutant strains), new metabolites were indicated to be correlated with tolerance within certain subsets of the samples. The relevance of these metabolites to 1-butanol tolerance were then validated from single-deletion strains of corresponding metabolic genes. The results showed that RANSAC-PLS is a promising strategy to identify unique metabolites that provide additional hints for phenotype improvement, which could not be detected by traditional PLS modeling using the entire dataset. PMID: 26861498 [PubMed - as supplied by publisher]

Related Articles Identification of Conserved and Diverse Metabolic Shifts during Rice Grain Development. Sci Rep. 2016;6:20942 Authors: Hu C, Tohge T, Chan SA, Song Y, Rao J, Cui B, Lin H, Wang L, Fernie AR, Zhang D, Shi J Abstract Seed development dedicates to reserve synthesis and accumulation and uncovering its genetic and biochemical mechanisms has been a major research focus. Although proteomic and transcriptomic analyses revealed dynamic changes of genes and enzymes involved, the information regarding concomitant metabolic changes is missing. Here we investigated the dynamic metabolic changes along the rice grain development of two japonica and two indica cultivars using non-targeted metabolomics approach, in which we successfully identified 214 metabolites. Statistical analyses revealed both cultivar and developmental stage dependent metabolic changes in rice grains. Generally, the stage specific metabolic kinetics corresponded well to the physiological status of the developing grains, and metabolic changes in developing rice grain are similar to those of dicot Arabidopsis and tomato at reserve accumulation stage but are different from those of dicots at seed desiccation stage. The remarkable difference in metabolite abundances between japonica and indica rice grain was observed at the reserve accumulation stage. Metabolite-metabolite correlation analysis uncovered potential new pathways for several metabolites. Taken together, this study uncovered both conserved and diverse development associated metabolic kinetics of rice grains, which facilitates further study to explore fundamental questions regarding the evolution of seed metabolic capabilities as well as their potential applications in crop improvement. PMID: 26860358 [PubMed - in process]

Related Articles Metabonomic analysis of the anti-inflammatory effects of volatile oils of Angelica sinensis on rat model of acute inflammation. Biomed Chromatogr. 2015 Jun;29(6):902-10 Authors: Zhang WQ, Hua YL, Zhang M, Ji P, Li JX, Zhang L, Li PL, Wei YM Abstract Metabonomics based on GC-MS was used to study the possible anti-inflammatory mechanisms of volatile oils of Angelica sinensis (VOAS) in rats with acute inflammation. Acute inflammation was induced by subcutaneous injection of carrageenan in rats. The levels of prostaglandin E2 (PGE2 ), histamine (HIS) and 5-hydroxytryptamine (5-HT) in the inflammatory fluid were detected. Principal component analysis and orthogonal partial least squares-discriminant analysis models were performed for pattern recognition analysis. After the administration of VOAS, the levels of PGE2 , HIS, and 5-HT returned to levels observed in normal group. According to GC-MS analysis, the intervention of VOAS in rats with acute inflammation induced substantial and characteristic changes in their metabolic profiles. Fourteen metabolite biomarkers, namely, lactic acid, malic acid, citric acid, trans-dehydroandrosterone, aldosterone, linoleic acid, hexadecanoic acid, pregnenolone, octadecenoic acid, myristic acid, l-histidine, octadecanoic acid, arachidonic acid (AA) and l-tryptophan, were detected in the inflammatory fluid. The levels of all biomarkers either increased or decreased significantly in model groups. VOAS possibly intervened in the metabolic process of inflammation by altering histidine metabolism, tryptophan metabolism, AA metabolism, steroid hormone biosynthesis, fatty acid metabolism and energy metabolism. Metabonomics was used to reflect an organism's physiological and metabolic state comprehensively, and it is a potentially powerful tool that reveals the anti-acute-inflammatory mechanism of VOAS. PMID: 25515821 [PubMed - indexed for MEDLINE]

Metabolomics study on the antitumor effect of marine natural compound flexibilide in HCT-116 colon cancer cell line. J Chromatogr B Analyt Technol Biomed Life Sci. 2016 Jan 8;1014:17-23 Authors: Gao D, Wang Y, Xie W, Yang T, Jiang Y, Guo Y, Guan J, Liu H Abstract A marine natural compound flexibilide isolated from the soft coral Sinularia flexibilis has been found to have antitumor activity. However, its pharmacological mechanism on tumor cells has not been studied. Herein, an ultra-performance liquid chromatography coupled to quadrupole time of-flight mass spectrometry (UPLC/Q-TOF MS) based metabolomics approach was established to investigate the antitumor effect of flexibilide on HCT-116 cells and its action mechanism. Q-TOF MS and MS/MS were used to identify significantly different metabolites. Comparing flexibilide-treated HCT-116 cells group with control group (dimethyl sulfoxide), 19 distinct metabolites involved in sphingolipid metabolism, alanine, aspartate and glutamate metabolism, d-glutamine and d-glutamate metabolism, glycerophospholipid metabolism, pyrimidine metabolism and others were discovered and identified. The significant decrease of phosphatidylcholine (PC) and phosphocholine levels and increase of lysophosphatidylcholine (LysoPC) levels in flexibilide treated cells suggested down-regulation of PC biosynthesis pathway. The decrease of sphingolipids reflected the lesions of cell membrane, and the up-regulation of sphingosine-1-phosphate indicated that TRAF2 and caspase-8 were likely to be activated by flexibilide and further caused cell apoptosis. Furthermore, TCA cycle was deemed to be down-regulated after flexibilide treatment, which might lead to an unsustainable of mitochondrial transmembrane potential MMP). The further measured descreased MMP with the increasing concentration of flexibilide treatment indiciated the dysfunction of mitochondrial which might finally lead to apoptosis. The UPLC/Q-TOF MS based metabolomics approach provides new insights into the mechanistic studies of flexibilide on tumor cells, which benefit its further improvement and application. PMID: 26859520 [PubMed - as supplied by publisher]

Impact of Freezing Delay Time on Tissue Samples for Metabolomic Studies. Front Oncol. 2016;6:17 Authors: Haukaas TH, Moestue SA, Vettukattil R, Sitter B, Lamichhane S, Segura R, Giskeødegård GF, Bathen TF Abstract INTRODUCTION: Metabolic profiling of intact tumor tissue by high-resolution magic angle spinning (HR MAS) MR spectroscopy (MRS) provides important biological information possibly useful for clinical diagnosis and development of novel treatment strategies. However, generation of high-quality data requires that sample handling from surgical resection until analysis is performed using systematically validated procedures. In this study, we investigated the effect of postsurgical freezing delay time on global metabolic profiles and stability of individual metabolites in intact tumor tissue. MATERIALS AND METHODS: Tumor tissue samples collected from two patient-derived breast cancer xenograft models (n = 3 for each model) were divided into pieces that were snap-frozen in liquid nitrogen at 0, 15, 30, 60, 90, and 120 min after surgical removal. In addition, one sample was analyzed immediately, representing the metabolic profile of fresh tissue exposed neither to liquid nitrogen nor to room temperature. We also evaluated the metabolic effect of prolonged spinning during the HR MAS experiments in biopsies from breast cancer patients (n = 14). All samples were analyzed by proton HR MAS MRS on a Bruker Avance DRX600 spectrometer, and changes in metabolic profiles were evaluated using multivariate analysis and linear mixed modeling. RESULTS: Multivariate analysis showed that the metabolic differences between the two breast cancer models were more prominent than variation caused by freezing delay time. No significant changes in levels of individual metabolites were observed in samples frozen within 30 min of resection. After this time point, levels of choline increased, whereas ascorbate, creatine, and glutathione (GS) levels decreased. Freezing had a significant effect on several metabolites but is an essential procedure for research and biobank purposes. Furthermore, four metabolites (glucose, glycine, glycerophosphocholine, and choline) were affected by prolonged HR MAS experiment time possibly caused by physical release of metabolites caused by spinning or due to structural degradation processes. CONCLUSION: The MR metabolic profiles of tumor samples are reproducible and robust to variation in postsurgical freezing delay up to 30 min. PMID: 26858940 [PubMed]

Central Role of Pyruvate Kinase in Carbon Co-Catabolism of Mycobacterium tuberculosis. J Biol Chem. 2016 Feb 8; Authors: Noy T, Vergnolle O, Hartman TE, Rhee KY, Jacobs WR, Berney M, Blanchard JS Abstract Mycobacterium tuberculosis (Mtb) displays a high degree of metabolic plasticity to adapt to challenging host environments. Genetic evidence suggests that Mtb relies mainly on fatty acid catabolism in the host. However, Mtb also maintains a functional glycolytic pathway and its role in the cellular metabolism of Mtb has yet to be understood. Pyruvate kinase catalyzes the last and rate-limiting step in glycolysis and the Mtb genome harbors one putative pyruvate kinase (pykA, Rv1617). Here we show that pykA encodes an active pyruvate kinase that is allosterically activated by glucose-6-phosphate (G6P) and adenosine monophosphate (AMP). Deletion of pykA prevents Mtb growth in the presence of fermentable carbon sources and has a cidal effect in the presence of glucose that correlates with elevated levels of the toxic catabolite methylglyoxal. Growth attenuation was also observed in media containing a combination of short chain fatty acids and glucose and surprisingly, in media containing odd- and even chain fatty acids alone. Untargeted high-sensitivity metabolomics revealed that inactivation of pyruvate kinase leads to accumulation of phosphoenolpyruvate (PEP), citrate and aconitate, which was consistent with allosteric inhibition of isocitrate dehydrogenase by PEP. This metabolic block could be relieved by addition of the alpha-ketoglutarate precursor glutamate. Taken together, our study identifies an essential role of pyruvate kinase in preventing metabolic block during carbon co-catabolism in Mtb. PMID: 26858255 [PubMed - as supplied by publisher]

Amino Acid Metabolism is Altered in Adolescents with Nonalcoholic Fatty Liver Disease-An Untargeted, High Resolution Metabolomics Study. J Pediatr. 2016 Feb 5; Authors: Jin R, Banton S, Tran VT, Konomi JV, Li S, Jones DP, Vos MB Abstract OBJECTIVE: To conduct an untargeted, high resolution exploration of metabolic pathways that was altered in association with hepatic steatosis in adolescents. STUDY DESIGN: This prospective, case-control study included 39 Hispanic-American, obese adolescents aged 11-17 years evaluated for hepatic steatosis using magnetic resonance spectroscopy. Of these 39 individuals, 30 had hepatic steatosis ≥5% and 9 were matched controls with hepatic steatosis <5%. Fasting plasma samples were analyzed in triplicate using ultra-high resolution metabolomics on a Thermo Fisher Q Exactive mass spectrometry system, coupled with C18 reverse phase liquid chromatography. Differences in plasma metabolites between adolescents with and without nonalcoholic fatty liver disease (NAFLD) were determined by independent t tests and visualized using Manhattan plots. Untargeted pathway analyses using Mummichog were performed among the significant metabolites to identify pathways that were most dysregulated in NAFLD. RESULTS: The metabolomics analysis yielded 9583 metabolites, and 7711 with 80% presence across all samples remained for statistical testing. Of these, 478 metabolites were associated with the presence of NAFLD compared with the matched controls. Pathway analysis revealed that along with lipid metabolism, several major amino acid pathways were dysregulated in NAFLD, with tyrosine metabolism being the most affected. CONCLUSIONS: Metabolic pathways of several amino acids are significantly disturbed in adolescents with elevated hepatic steatosis. This is a novel finding and suggests that these pathways may be integral in the mechanisms of NAFLD. PMID: 26858195 [PubMed - as supplied by publisher]

European headache federation consensus on technical investigation for primary headache disorders. J Headache Pain. 2015 Dec;17(1):5 Authors: Mitsikostas DD, Ashina M, Craven A, Diener HC, Goadsby PJ, Ferrari MD, Lampl C, Paemeleire K, Pascual J, Siva A, Olesen J, Osipova V, Martelletti P, EHF committee Abstract The diagnosis of primary headache disorders is clinical and based on the diagnostic criteria of the International Headache Society (ICHD-3-beta). However several brain conditions may mimic primary headache disorders and laboratory investigation may be needed. This necessity occurs when the treating physician doubts for the primary origin of headache. Features that represent a warning for a possible underlying disorder causing the headache are new onset headache, change in previously stable headache pattern, headache that abruptly reaches the peak level, headache that changes with posture, headache awakening the patient, or precipitated by physical activity or Valsalva manoeuvre, first onset of headache ≥50 years of age, neurological symptoms or signs, trauma, fever, seizures, history of malignancy, history of HIV or active infections, and prior history of stroke or intracranial bleeding. All national headache societies and the European Headache Alliance invited to review and comment the consensus before the final draft. The consensus recommends brain MRI for the case of migraine with aura that persists on one side or in brainstem aura. Persistent aura without infarction and migrainous infarction require brain MRI, MRA and MRV. Brain MRI with detailed study of the pituitary area and cavernous sinus, is recommended for all TACs. For primary cough headache, exercise headache, headache associated with sexual activity, thunderclap headache and hypnic headache apart from brain MRI additional tests may be required. Because there is little and no good evidence the committee constructed a consensus based on the opinion of experts, and should be treated as imperfect. PMID: 26857820 [PubMed - in process]