Integrative Molecular Phenotyping
INTEGRATIVE MOLECULAR
PHENOTYPING
WHEELOCK LABORATORY
DEPARTMENT OF MEDICAL
BIOCHEMISTRY AND BIOPHYSICS
WHEELOCK LABORATORY
DEPARTMENT OF MEDICAL
BIOCHEMISTRY AND BIOPHYSICS
WHEELOCK LABORATORY
DEPARTMENT OF MEDICAL
BIOCHEMISTRY AND BIOPHYSICS
WHEELOCK LABORATORY
DEPARTMENT OF MEDICAL
BIOCHEMISTRY AND BIOPHYSICS
WHEELOCK LABORATORY
DEPARTMENT OF MEDICAL
BIOCHEMISTRY AND BIOPHYSICS
WHEELOCK LABORATORY

PubMed

Antiandrogenic therapy with finasteride attenuates cardiac hypertrophy and left ventricular dysfunction.

Tue, 16/06/2015 - 13:43
Related Articles Antiandrogenic therapy with finasteride attenuates cardiac hypertrophy and left ventricular dysfunction. Circulation. 2015 Mar 24;131(12):1071-81 Authors: Zwadlo C, Schmidtmann E, Szaroszyk M, Kattih B, Froese N, Hinz H, Schmitto JD, Widder J, Batkai S, Bähre H, Kaever V, Thum T, Bauersachs J, Heineke J Abstract BACKGROUND: In comparison with men, women have a better prognosis when experiencing aortic valve stenosis, hypertrophic cardiomyopathy, or heart failure. Recent data suggest that androgens like testosterone or the more potent dihydrotestosterone contribute to the development of cardiac hypertrophy and failure. Therefore, we analyzed whether antiandrogenic therapy with finasteride, which inhibits the generation of dihydrotestosterone by the enzyme 5-α-reductase, improves pathological ventricular remodeling and heart failure. METHODS AND RESULTS: We found a strongly induced expression of all 3 isoforms of the 5-α-reductase (Srd5a1 to Srd5a3) in human and mouse hearts with pathological hypertrophy, which was associated with increased myocardial accumulation of dihydrotestosterone. Starting 1 week after the induction of pressure overload by transaortic constriction, mice were treated with finasteride for 2 weeks. Cardiac function, hypertrophy, dilation, and fibrosis were markedly improved in response to finasteride treatment in not only male, but also in female mice. In addition, finasteride also very effectively improved cardiac function and mortality after long-term pressure overload and prevented disease progression in cardiomyopathic mice with myocardial Gαq overexpression. Mechanistically, finasteride, by decreasing dihydrotestosterone, potently inhibited hypertrophy and Akt-dependent prohypertrophic signaling in isolated cardiac myocytes, whereas the introduction of constitutively active Akt blunted these effects of finasteride. CONCLUSIONS: Finasteride, which is currently used in patients to treat prostate disease, potently reverses pathological cardiac hypertrophy and dysfunction in mice and might be a therapeutic option for heart failure. PMID: 25632043 [PubMed - indexed for MEDLINE]

Comparative metabolite profiling of two rice genotypes with contrasting salt stress tolerance at the seedling stage.

Tue, 16/06/2015 - 13:43
Related Articles Comparative metabolite profiling of two rice genotypes with contrasting salt stress tolerance at the seedling stage. PLoS One. 2014;9(9):e108020 Authors: Zhao X, Wang W, Zhang F, Deng J, Li Z, Fu B Abstract BACKGROUND: Rice is sensitive to salt stress, especially at the seedling stage, with rice varieties differing remarkably in salt tolerance (ST). To understand the physiological mechanisms of ST, we investigated salt stress responses at the metabolite level. METHODS: Gas chromatography-mass spectrometry was used to profile metabolite changes in the salt-tolerant line FL478 and the sensitive variety IR64 under a salt-stress time series. Additionally, several physiological traits related to ST were investigated. RESULTS: We characterized 92 primary metabolites in the leaves and roots of the two genotypes under stress and control conditions. The metabolites were temporally, tissue-specifically and genotype-dependently regulated under salt stress. Sugars and amino acids (AAs) increased significantly in the leaves and roots of both genotypes, while organic acids (OAs) increased in roots and decreased in leaves. Compared with IR64, FL478 experienced greater increases in sugars and AAs and more pronounced decreases in OAs in both tissues; additionally, the maximum change in sugars and AAs occurred later, while OAs changed earlier. Moreover, less Na+ and higher relative water content were observed in FL478. Eleven metabolites, including AAs and sugars, were specifically increased in FL478 over the course of the treatment. CONCLUSIONS: Metabolic responses of rice to salt stress are dynamic and involve many metabolites. The greater ST of FL478 is due to different adaptive reactions at different stress times. At early salt-stress stages, FL478 adapts to stress by decreasing OA levels or by quickly depressing growth; during later stages, more metabolites are accumulated, thereby serving as compatible solutes against osmotic challenge induced by salt stress. PMID: 25265195 [PubMed - indexed for MEDLINE]

A multienzyme complex channels substrates and electrons through acetyl-CoA and methane biosynthesis pathways in Methanosarcina.

Tue, 16/06/2015 - 13:43
Related Articles A multienzyme complex channels substrates and electrons through acetyl-CoA and methane biosynthesis pathways in Methanosarcina. PLoS One. 2014;9(9):e107563 Authors: Lieber DJ, Catlett J, Madayiputhiya N, Nandakumar R, Lopez MM, Metcalf WW, Buan NR Abstract Multienzyme complexes catalyze important metabolic reactions in many organisms, but little is known about the complexes involved in biological methane production (methanogenesis). A crosslinking-mass spectrometry (XL-MS) strategy was employed to identify proteins associated with coenzyme M-coenzyme B heterodisulfide reductase (Hdr), an essential enzyme in all methane-producing archaea (methanogens). In Methanosarcina acetivorans, Hdr forms a multienzyme complex with acetyl-CoA decarbonylase synthase (ACDS), and F420-dependent methylene-H4MPT reductase (Mer). ACDS is essential for production of acetyl-CoA during growth on methanol, or for methanogenesis from acetate, whereas Mer is essential for methanogenesis from all substrates. Existence of a Hdr:ACDS:Mer complex is consistent with growth phenotypes of ACDS and Mer mutant strains in which the complex samples the redox status of electron carriers and directs carbon flux to acetyl-CoA or methanogenesis. We propose the Hdr:ACDS:Mer complex comprises a special class of multienzyme redox complex which functions as a "biological router" that physically links methanogenesis and acetyl-CoA biosynthesis pathways. PMID: 25232733 [PubMed - indexed for MEDLINE]

Allele compensation in tip60+/- mice rescues white adipose tissue function in vivo.

Tue, 16/06/2015 - 13:43
Related Articles Allele compensation in tip60+/- mice rescues white adipose tissue function in vivo. PLoS One. 2014;9(5):e98343 Authors: Gao Y, Hamers N, Rakhshandehroo M, Berger R, Lough J, Kalkhoven E Abstract Adipose tissue is a key regulator of energy homestasis. The amount of adipose tissue is largely determined by adipocyte differentiation (adipogenesis), a process that is regulated by the concerted actions of multiple transcription factors and cofactors. Based on in vitro studies in murine 3T3-L1 preadipocytes and human primary preadipocytes, the transcriptional cofactor and acetyltransferase Tip60 was recently identified as an essential adipogenic factor. We therefore investigated the role of Tip60 on adipocyte differentiation and function, and possible consequences on energy homeostasis, in vivo. Because homozygous inactivation results in early embryonic lethality, Tip60+/- mice were used. Heterozygous inactivation of Tip60 had no effect on body weight, despite slightly higher food intake by Tip60+/- mice. No major effects of heterozygous inactivation of Tip60 were observed on adipose tissue and liver, and Tip60+/- displayed normal glucose tolerance, both on a low fat and a high fat diet. While Tip60 mRNA was reduced to 50% in adipose tissue, the protein levels were unaltered, suggesting compensation by the intact allele. These findings indicate that the in vivo role of Tip60 in adipocyte differentiation and function cannot be properly addressed in Tip60+/- mice, but requires the generation of adipose tissue-specific knock out animals or specific knock-in mice. PMID: 24870614 [PubMed - indexed for MEDLINE]

The potential biomarker panels for identification of Major Depressive Disorder (MDD) patients with and without early life stress (ELS) by metabonomic analysis.

Tue, 16/06/2015 - 13:43
Related Articles The potential biomarker panels for identification of Major Depressive Disorder (MDD) patients with and without early life stress (ELS) by metabonomic analysis. PLoS One. 2014;9(5):e97479 Authors: Ding X, Yang S, Li W, Liu Y, Li Z, Zhang Y, Li L, Liu S Abstract OBJECTIVE: The lack of the disease biomarker to support objective laboratory tests still constitutes a bottleneck in the clinical diagnosis and evaluation of major depressive disorder (MDD) and its subtypes. We used metabonomic techniques to screen the diagnostic biomarker panels from the plasma of MDD patients with and without early life stress (ELS) experience. METHODS: Plasma samples were collected from 25 healthy adults and 46 patients with MDD, including 23 patients with ELS and 23 patients without ELS. Furthermore, gas chromatography/mass spectrometry (GC/MS) coupled with multivariate statistical analysis was used to identify the differences in global plasma metabolites among the 3 groups. RESULTS: The distinctive metabolic profiles exist either between healthy subjects and MDD patients or between the MDD patients with ELS experience (ELS/MDD patients) and the MDD patients without it (non-ELS/MDD patients), and some diagnostic panels of feature metabolites' combination have higher predictive potential than the diagnostic panels of differential metabolites. CONCLUSIONS: These findings in this study have high potential of being used as novel laboratory diagnostic tool for MDD patients and it with ELS or not in clinical application. PMID: 24870353 [PubMed - indexed for MEDLINE]

Combined systems approaches reveal highly plastic responses to antimicrobial peptide challenge in Escherichia coli.

Tue, 16/06/2015 - 13:43
Related Articles Combined systems approaches reveal highly plastic responses to antimicrobial peptide challenge in Escherichia coli. PLoS Pathog. 2014 May;10(5):e1004104 Authors: Kozlowska J, Vermeer LS, Rogers GB, Rehnnuma N, Amos SB, Koller G, McArthur M, Bruce KD, Mason AJ Abstract Obtaining an in-depth understanding of the arms races between peptides comprising the innate immune response and bacterial pathogens is of fundamental interest and will inform the development of new antibacterial therapeutics. We investigated whether a whole organism view of antimicrobial peptide (AMP) challenge on Escherichia coli would provide a suitably sophisticated bacterial perspective on AMP mechanism of action. Selecting structurally and physically related AMPs but with expected differences in bactericidal strategy, we monitored changes in bacterial metabolomes, morphological features and gene expression following AMP challenge at sub-lethal concentrations. For each technique, the vast majority of changes were specific to each AMP, with such a plastic response indicating E. coli is highly capable of discriminating between specific antibiotic challenges. Analysis of the ontological profiles generated from the transcriptomic analyses suggests this approach can accurately predict the antibacterial mode of action, providing a fresh, novel perspective for previous functional and biophysical studies. PMID: 24789011 [PubMed - indexed for MEDLINE]

Systems medicine: a new approach to clinical practice.

Tue, 16/06/2015 - 13:43
Related Articles Systems medicine: a new approach to clinical practice. Arch Bronconeumol. 2014 Oct;50(10):444-51 Authors: Cardinal-Fernández P, Nin N, Ruíz-Cabello J, Lorente JA Abstract Most respiratory diseases are considered complex diseases as their susceptibility and outcomes are determined by the interaction between host-dependent factors (genetic factors, comorbidities, etc.) and environmental factors (exposure to microorganisms or allergens, treatments received, etc.) The reductionist approach in the study of diseases has been of fundamental importance for the understanding of the different components of a system. Systems biology or systems medicine is a complementary approach aimed at analyzing the interactions between the different components within one organizational level (genome, transcriptome, proteome), and then between the different levels. Systems medicine is currently used for the interpretation and understanding of the pathogenesis and pathophysiology of different diseases, biomarker discovery, design of innovative therapeutic targets, and the drawing up of computational models for different biological processes. In this review we discuss the most relevant concepts of the theory underlying systems medicine, as well as its applications in the various biological processes in humans. PMID: 24397963 [PubMed - indexed for MEDLINE]

Metabolome-scale de novo pathway reconstruction using regioisomer-sensitive graph alignments.

Mon, 15/06/2015 - 12:38
Metabolome-scale de novo pathway reconstruction using regioisomer-sensitive graph alignments. Bioinformatics. 2015 Jun 15;31(12):i161-i170 Authors: Yamanishi Y, Tabei Y, Kotera M Abstract MOTIVATION: Recent advances in mass spectrometry and related metabolomics technologies have enabled the rapid and comprehensive analysis of numerous metabolites. However, biosynthetic and biodegradation pathways are only known for a small portion of metabolites, with most metabolic pathways remaining uncharacterized. RESULTS: In this study, we developed a novel method for supervised de novo metabolic pathway reconstruction with an improved graph alignment-based approach in the reaction-filling framework. We proposed a novel chemical graph alignment algorithm, which we called PACHA (Pairwise Chemical Aligner), to detect the regioisomer-sensitive connectivities between the aligned substructures of two compounds. Unlike other existing graph alignment methods, PACHA can efficiently detect only one common subgraph between two compounds. Our results show that the proposed method outperforms previous descriptor-based methods or existing graph alignment-based methods in the enzymatic reaction-likeness prediction for isomer-enriched reactions. It is also useful for reaction annotation that assigns potential reaction characteristics such as EC (Enzyme Commission) numbers and PIERO (Enzymatic Reaction Ontology for Partial Information) terms to substrate-product pairs. Finally, we conducted a comprehensive enzymatic reaction-likeness prediction for all possible uncharacterized compound pairs, suggesting potential metabolic pathways for newly predicted substrate-product pairs. CONTACT: maskot@bio.titech.ac.jp. PMID: 26072478 [PubMed - as supplied by publisher]

The Caenorhabditis elegans lipidome A primer for lipid analysis in Caenorhabditis elegans.

Mon, 15/06/2015 - 12:38
The Caenorhabditis elegans lipidome A primer for lipid analysis in Caenorhabditis elegans. Arch Biochem Biophys. 2015 Jun 10; Authors: Witting M, Schmitt-Kopplin P Abstract Lipids play important roles in biology, ranging from building blocks of membranes to signaling lipids. The nematode and model organism Caenorhabditis elegans has been used to explore lipid metabolism and several techniques for their analysis have been employed. These techniques include different possibilities ranging from visualization of lipid droplets, analysis of total fatty acids to analysis of complex lipids using lipidomics approaches. Lipidomics evolved from metabolomics, the latest off-spring of the "omics"-technologies and aims to characterize the lipid content of a given organism or system. Although being an extensively studied model organism, only a few applications of lipidomics to C. elegans have been reported to far, but the number is steadily increasing with more applications expected in the near future. This review gives an overview on the C. elegans lipidome, lipid classes it contains and ways to analyze them. It serves as primer for scientists interested in studying lipids in this model organism and list methods used so far and what information can be derived from them. Lastly, challenges and future (methodological) research directions, together with new methods potentially useful for C. elegans lipid research are discussed. PMID: 26072113 [PubMed - as supplied by publisher]

Multi-level systems biology modeling characterized the atheroprotective efficiencies of modified dairy fats in a hamster model.

Sun, 14/06/2015 - 14:24
Related Articles Multi-level systems biology modeling characterized the atheroprotective efficiencies of modified dairy fats in a hamster model. Am J Physiol Heart Circ Physiol. 2015 Jun 12;:ajpheart.00032.2015 Authors: Martin JC, Berton A, Ginies C, Bott R, Scheercousse P, Saddi A, Gripois D, Landrier JF, Dalemans D, Alessi MC, Delplanque B Abstract We assessed the atheroprotective efficiency of modified dairy fats in hyperlipidemic hamsters. A systems biology approach was implemented to reveal and quantify the dietary fat-related components of the disease. Three modified dairy fats (40% energy) were prepared from regular butter by mixing with a plant oil mixture, by removing cholesterol alone or by removing cholesterol in combination with reducing saturated fatty acids. A plant oil mixture with regular butter was used as the control diet. The atherosclerosis severity (aortic cholesteryl-ester level) was higher in the regular butter-fed hamsters than in the other four groups (P < 0.05). Eighty-seven of the 1666 variables measured from multi-platform analysis were found to be strongly associated with the disease. When aggregated into 10 biological clusters combined into a multivariate predictive equation, these 87 variables explained 81% of the disease variability. The biological cluster "regulation of lipid transport and metabolism" appeared central to atherogenic development relative to diets. The "vitamin E metabolism" cluster was the main driver of atheroprotection with the best performing transformed dairy fat. Under conditions that promote atherosclerosis, the impact of dairy fats on atherogenesis could be greatly ameliorated by technological modifications. Our modeling approach allowed for identifying and quantifying the contribution of complex factors to atherogenic development in each dietary setup. PMID: 26071539 [PubMed - as supplied by publisher]

Phenolic amides are potent inhibitors of de novo nucleotide biosynthesis.

Sun, 14/06/2015 - 14:24
Related Articles Phenolic amides are potent inhibitors of de novo nucleotide biosynthesis. Appl Environ Microbiol. 2015 Jun 12; Authors: Pisithkul T, Jacobson TB, O'Brien TJ, Stevenson DM, Amador-Noguez D Abstract An outstanding challenge towards efficient production of biofuels and value-added chemicals from plant biomass is the impact that lignocellulose-derived inhibitors have on microbial fermentations. Elucidating the mechanisms that underlie their toxicity is critical for developing strategies to overcome them. Here, using E. coli as a model system, we investigated the metabolic effects and toxicity mechanisms of feruloyl and coumaroyl amide, the predominant phenolic compounds in ammonia-pretreated biomass hydrolysates. Using metabolomics, isotope tracers, and biochemical assays, we show that these two phenolic amides act as potent and fast-acting inhibitors of purine and pyrimidine biosynthetic pathways. Feruloyl or coumaroyl amide exposure leads to: 1) rapid buildup of 5-phosphoribosylpyrophosphate (PRPP), a key precursor in nucleotide biosynthesis; 2) rapid decrease in the levels of pyrimidine biosynthetic intermediates; and 3) long-term generalized decrease in nucleotide and deoxynucleotide levels. Tracer experiments using (13)C-sugars and (15)N-ammonia demonstrated that carbon and nitrogen flux into nucleotides and deoxynucleotides are inhibited by these phenolic amides. We found that these effects are mediated via direct inhibition of glutamine amidotransferases that participate in nucleotide biosynthetic pathways. In particular, feruloyl amide is a competitive inhibitor of glutamine PRPP amidotransferase (PurF), which catalyzes the first committed step in de novo purine biosynthesis. Finally, external nucleoside supplementation prevents phenolic amide-mediated growth inhibition by allowing nucleotide biosynthesis via salvage pathways. The results presented here will help develop strategies to overcome toxicity of phenolic compounds and facilitate engineering of more efficient microbial producers of biofuels and chemicals. PMID: 26070680 [PubMed - as supplied by publisher]

Compartmentation of metabolism of the C12-, C9-, and C5-n-dicarboxylates in rat liver, investigated by mass isotopomer analysis: Anaplerosis from dodecanedioate.

Sun, 14/06/2015 - 14:24
Related Articles Compartmentation of metabolism of the C12-, C9-, and C5-n-dicarboxylates in rat liver, investigated by mass isotopomer analysis: Anaplerosis from dodecanedioate. J Biol Chem. 2015 Jun 12; Authors: Jin Z, Bian F, Tomcik K, Kelleher JK, Zhang GF, Brunengraber H Abstract We investigated the compartmentation of the catabolism of dodecanedioate (DODA), azelate and glutarate in perfused rat livers, using a combination of metabolomics and mass isotopomer analyses. Livers were perfused with recirculating or nonrecirculating buffer containing one fully (13)C-labeled dicarboxylate. Information on the peroxisomal vs mitochondrial catabolism was gathered from the labeling patterns of acetyl-CoA proxies, i.e., total acetyl-CoA, the acetyl moiety of citrate, C-1+2 of β-hydroxybutyrate, malonyl-CoA and acetylcarnitine. Additional information was obtained from the labeling patterns of citric acid cycle intermediates and related compounds. The data characterize the partial oxidation of DODA and azelate in peroxisomes, with terminal oxidation in mitochondria. We did not find evidence of peroxisomal oxidation of glutarate. Unexpectedly, DODA contributes a substantial fraction to anaplerosis of the citric acid cycle. This opens the possibility to use water-soluble DODA in nutritional or pharmacological anaplerotic therapy when other anaplerotic substrates are impractical or contraindicated, e.g., in propionic acidemia and methylmalonic acidemia. PMID: 26070565 [PubMed - as supplied by publisher]

metabolomics; +17 new citations

Sat, 13/06/2015 - 13:46
17 new pubmed citations were retrieved for your search. Click on the search hyperlink below to display the complete search results: metabolomics These pubmed results were generated on 2015/06/13PubMed comprises more than 24 million citations for biomedical literature from MEDLINE, life science journals, and online books. Citations may include links to full-text content from PubMed Central and publisher web sites.

p53 attenuates AKT signaling by modulating membrane phospholipid composition.

Thu, 11/06/2015 - 14:43
Related Articles p53 attenuates AKT signaling by modulating membrane phospholipid composition. Oncotarget. 2015 Jun 3; Authors: Rueda-Rincon N, Bloch K, Derua R, Vyas R, Harms A, Hankemeier T, Khan NA, Dehairs J, Bagadi M, Binda MM, Waelkens E, Marine JC, Swinnen JV Abstract The p53 tumor suppressor is the central component of a complex network of signaling pathways that protect organisms against the propagation of cells carrying oncogenic mutations. Here we report a previously unrecognized role of p53 in membrane phospholipids composition. By repressing the expression of stearoyl-CoA desaturase 1, SCD, the enzyme that converts saturated to mono-unsaturated fatty acids, p53 causes a shift in the content of phospholipids with mono-unsaturated acyl chains towards more saturated phospholipid species, particularly of the phosphatidylinositol headgroup class. This shift affects levels of phosphatidylinositol phosphates, attenuates the oncogenic AKT pathway, and contributes to the p53-mediated control of cell survival. These findings expand the p53 network to phospholipid metabolism and uncover a new molecular pathway connecting p53 to AKT signaling. PMID: 26061814 [PubMed - as supplied by publisher]

Pyrimidine Metabolism: Dynamic and Versatile Pathways in Pathogens and Cellular Development.

Thu, 11/06/2015 - 14:43
Related Articles Pyrimidine Metabolism: Dynamic and Versatile Pathways in Pathogens and Cellular Development. J Genet Genomics. 2015 May 20;42(5):195-205 Authors: Garavito MF, Narváez-Ortiz HY, Zimmermann BH Abstract The importance of pyrimidines lies in the fact that they are structural components of a broad spectrum of key molecules that participate in diverse cellular functions, such as synthesis of DNA, RNA, lipids, and carbohydrates. Pyrimidine metabolism encompasses all enzymes involved in the synthesis, degradation, salvage, interconversion and transport of these molecules. In this review, we summarize recent publications that document how pyrimidine metabolism changes under a variety of conditions, including, when possible, those studies based on techniques of genomics, transcriptomics, proteomics, and metabolomics. First, we briefly look at the dynamics of pyrimidine metabolism during nonpathogenic cellular events. We then focus on changes that pathogen infections cause in the pyrimidine metabolism of their host. Next, we discuss the effects of antimetabolites and inhibitors, and finally we consider the consequences of genetic manipulations, such as knock-downs, knock-outs, and knock-ins, of pyrimidine enzymes on pyrimidine metabolism in the cell. PMID: 26059768 [PubMed - as supplied by publisher]

Determination of the in vivo NAD/NADH ratio in S. cerevisiae under anaerobic conditions using alcohol dehydrogenase as sensor reaction.

Thu, 11/06/2015 - 14:43
Related Articles Determination of the in vivo NAD/NADH ratio in S. cerevisiae under anaerobic conditions using alcohol dehydrogenase as sensor reaction. Yeast. 2015 Jun 9; Authors: Bekers KM, Heijnen JJ, van Gulik WM Abstract With the current quantitative metabolomics techniques only whole cell concentrations of NAD and NADH can be quantified. These measurements cannot provide information on the in vivo redox state of the cells, which is determined by the ratio of the free forms only. In this work we quantified the free NAD/NADH ratio in yeast under anaerobic conditions using alcohol dehydrogenase (ADH) and the lumped reaction of glyceraldehyde-3-phosphate dehydrogenase and 3-phosphoglycerate kinase as sensor reactions. We show that with an alternative accurate acetaldehyde determination method, based on rapid sampling, instantaneous derivatization with 2,4 diaminophenol hydrazine (DNPH) and quantification with HPLC, the ADH catalyzed oxidation of ethanol to acetaldehyde can be applied as a relatively fast and simple sensor reaction to quantify the free NAD/NADH ratio under anaerobic conditions. We evaluated the applicability of ADH as a sensor reaction in the yeast Saccharomyces cerevisiae grown in anaerobic glucose limited chemostats during steady state and dynamic conditions. The results found in this study show that the cytosolic redox status (NAD/NADH ratio) of yeast is at least one order of magnitude lower, and thus much more reduced, under anaerobic conditions compared to aerobic glucose-limited steady state conditions. The more reduced state of the cytosol under anaerobic conditions has major implications for (central) metabolism. Accurate determination of the free NAD/NADH ratio is therefore of importance for the unravelling of in vivo enzyme kinetics and to judge accurately the thermodynamic reversibility of each redox reaction. PMID: 26059529 [PubMed - as supplied by publisher]

Meta-analysis of organ-specific differences in the structure of the immune infiltrate in major malignancies.

Thu, 11/06/2015 - 14:43
Related Articles Meta-analysis of organ-specific differences in the structure of the immune infiltrate in major malignancies. Oncotarget. 2015 May 20;6(14):11894-909 Authors: Stoll G, Bindea G, Mlecnik B, Galon J, Zitvogel L, Kroemer G Abstract Anticancer immunosurveillance is one of the major endogenous breaks of tumor progression. Here, we analyzed gene expression pattern indicative of the presence of distinct leukocyte subtypes within four cancer types (breast cancer, colorectal carcinoma, melanoma, and non-small cell lung cancer) and 20 different microarray datasets corresponding to a total of 3471 patients. Multiple metagenes reflecting the presence of such immune cell subtypes were highly reproducible across distinct cohorts. Nonetheless, there were sizable differences in the correlation patterns among such immune-relevant metagenes across distinct malignancies. The reproducibility of the correlations among immune-relevant metagenes was highest in breast cancer (followed by colorectal cancer, non-small cell lung cancer and melanoma), reflecting the fact that mammary carcinoma has an intrinsically better prognosis than the three other malignancies. Among breast cancer patients, we found that the expression of a lysosomal enzyme-related metagene centered around ASAH1 (which codes for N-acylsphingosine amidohydrolase-1, also called acid ceramidase) exhibited a higher correlation with multiple immune-relevant metagenes in patients that responded to neoadjuvant chemotherapy than in non-responders. Altogether, this meta-analysis revealed novel organ-specific features of the immune infiltrate in distinct cancer types, as well as a strategy for defining new prognostic biomarkers. PMID: 26059437 [PubMed - in process]

The Use of 'Omics Technology to Rationally Improve Industrial Mammalian Cell Line Performance.

Thu, 11/06/2015 - 14:43
Related Articles The Use of 'Omics Technology to Rationally Improve Industrial Mammalian Cell Line Performance. Biotechnol Bioeng. 2015 Jun 9; Authors: Lewis AM, Abu-Absi NR, Borys MC, Li ZJ Abstract Biologics represent an increasingly important class of therapeutics, with 7 of the 10 top selling drugs from 2013 being in this class. Furthermore, health authority approval of biologics in the immuno-oncology space is expected to transform treatment of patients with debilitating and deadly diseases. The growing importance of biologics in the healthcare field has also resulted in the recent approvals of several biosimilars. These recent developments, combined with pressure to provide treatments at lower costs to payers, are resulting in increasing need for the industry to quickly and efficiently develop high yielding, robust processes for the manufacture of biologics with the ability to control quality attributes within narrow distributions. Achieving this level of manufacturing efficiency and the ability to design processes capable of regulating growth, death and other cellular pathways through manipulation of media, feeding strategies and other process parameters will undoubtedly be facilitated through systems biology tools generated in academic and public research communities. Here we discuss the intersection of systems biology, 'Omics technologies, and mammalian bioprocess sciences. Specifically, we address how these methods in conjunction with traditional monitoring techniques represent a unique opportunity to better characterize and understand host cell culture state, shift from an empirical to rational approach to process development and optimization of bioreactor cultivation processes. We summarize six key areas: 1) research applied to parental, non-recombinant cell lines, 2) systems level datasets generated with recombinant cell lines, 3) datasets linking phenotypic traits to relevant biomarkers, 4) data depositories and bioinformatics tools, 5) in silico model development, and 6) examples where these approaches have been used to rationally improve cellular processes. We critically assess relevant and state of the art research being conducted in academic, government and industrial laboratories. Furthermore, we apply our expertise in bioprocess to define a potential model for integration of these systems biology approaches into biologics development. This article is protected by copyright. All rights reserved. PMID: 26059229 [PubMed - as supplied by publisher]

Combinatorial chemistry in nematodes: modular assembly of primary metabolism-derived building blocks.

Thu, 11/06/2015 - 14:43
Related Articles Combinatorial chemistry in nematodes: modular assembly of primary metabolism-derived building blocks. Nat Prod Rep. 2015 Jun 10; Authors: von Reuss SH, Schroeder FC Abstract Covering: up to 2015The nematode Caenorhabditis elegans was the first animal to have its genome fully sequenced and has become an important model organism for biomedical research. However, like many other animal model systems, its metabolome remained largely uncharacterized, until recent investigations demonstrated the importance of small molecule-based signalling cascades for virtually every aspect of nematode biology. These studies have revealed that nematodes are amazingly skilled chemists: using simple building blocks from conserved primary metabolism and a strategy of modular assembly, C. elegans and other nematode species create complex molecular architectures to regulate their development and behaviour. These nematode-derived modular metabolites (NDMMs) are based on the dideoxysugars ascarylose or paratose, which serve as scaffolds for attachment of moieties from lipid, amino acid, carbohydrate, citrate, and nucleoside metabolism. Mutant screens and comparative metabolomics based on NMR spectroscopy and MS have so-far revealed several 100 different ascarylose ("ascarosides") and a few paratose ("paratosides") derivatives, many of which represent potent signalling molecules that can be active at femtomolar levels, regulating development, behaviour, body shape, and many other life history traits. NDMM biosynthesis appears to be carefully regulated as assembly of different modules proceeds with very high specificity. Preliminary biosynthetic studies have confirmed the primary metabolism origin of some NDMM building blocks, whereas the mechanisms that underlie their highly specific assembly are not understood. Considering their functions and biosynthetic origin, NDMMs represent a new class of natural products that cannot easily be classified as "primary" or "secondary". We believe that the identification of new variants of primary metabolism-derived structures that serve important signalling functions in C. elegans and other nematodes provides a strong incentive for a comprehensive re-analysis of metabolism in higher animals, including humans. PMID: 26059053 [PubMed - as supplied by publisher]

Crosstalk between branched chain amino acids and hepatic mitochondria is compromised in nonalcoholic fatty liver disease.

Thu, 11/06/2015 - 14:43
Related Articles Crosstalk between branched chain amino acids and hepatic mitochondria is compromised in nonalcoholic fatty liver disease. Am J Physiol Endocrinol Metab. 2015 Jun 9;:ajpendo.00161.2015 Authors: Sunny NE, Kalavalapalli S, Bril F, Garrett TJ, Nautiyal M, Mathew JT, Williams CM, Cusi K Abstract Elevated plasma branched chain amino acids (BCAA) in the setting of insulin resistance have been relevant in predicting type 2 diabetes mellitus (T2DM) onset, but their role in the etiology of hepatic insulin resistance remains uncertain. We determined the link between BCAA and dysfunctional hepatic tri-carboxylic acid (TCA) cycle, which is a central feature of hepatic insulin resistance and nonalcoholic fatty liver disease (NAFLD). Plasma metabolites under basal fasting and euglycemic hyperinsulinemic clamps (insulin stimulation) were measured in 94 human subjects with varying degrees of insulin sensitivity, to identify their relationships with insulin resistance. Further, the impact of elevated BCAA on hepatic TCA cycle was determined in a diet induced mouse model of NAFLD, utilizing targeted metabolomics and nuclear magnetic resonance (NMR) based metabolic flux analysis. Insulin stimulation revealed robust relationships between human plasma BCAA and indices of insulin resistance, indicating chronic metabolic overload from BCAA. Human plasma BCAA and long chain acylcarnitines also showed a positive correlation, suggesting modulation of mitochondrial metabolism by BCAA. Concurrently, mice with NAFLD failed to optimally induce hepatic mTORC1, plasma ketones and hepatic long chain acylcarnitines, following acute elevation of plasma BCAA. Furthermore, elevated BCAA failed to induce multiple fluxes through hepatic TCA cycle in mice with NAFLD. Our data suggest that BCAA are essential to mediate efficient channeling of carbon substrates for oxidation through mitochondrial TCA cycle. Impairment of BCAA-mediated up-regulation of TCA cycle could be a significant contributor to mitochondrial dysfunction in NAFLD. PMID: 26058864 [PubMed - as supplied by publisher]

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