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

Metabolite signatures of doxorubicin induced toxicity in human induced pluripotent stem cell-derived cardiomyocytes.

Thu, 20/04/2017 - 12:59
Related Articles Metabolite signatures of doxorubicin induced toxicity in human induced pluripotent stem cell-derived cardiomyocytes. Amino Acids. 2017 Apr 18;: Authors: Chaudhari U, Ellis JK, Wagh V, Nemade H, Hescheler J, Keun HC, Sachinidis A Abstract Drug-induced off-target cardiotoxicity, particularly following anti-cancer therapy, is a major concern in new drug discovery and development. To ensure patient safety and efficient pharmaceutical drug development, there is an urgent need to develop more predictive cell model systems and distinct toxicity signatures. In this study, we applied our previously proposed repeated exposure toxicity methodology and performed (1)H NMR spectroscopy-based extracellular metabolic profiling in culture medium of human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) exposed to doxorubicin (DOX), an anti-cancer agent. Single exposure to DOX did not show alteration in the basal level of extracellular metabolites while repeated exposure to DOX caused reduction in the utilization of pyruvate and acetate, and accumulation of formate compared to control culture medium. During drug washout, only pyruvate showed reversible effect and restored its utilization by hiPSC-CMs. On the other hand, formate and acetate showed irreversible effect in response to DOX exposure. DOX repeated exposure increased release of lactate dehydrogenase (LDH) in culture medium suggesting cytotoxicity events, while declined ATP levels in hiPSC-CMs. Our data suggests DOX perturbed mitochondrial metabolism in hiPSC-CMs. Pyruvate, acetate and formate can be used as metabolite signatures of DOX induced cardiotoxicity. Moreover, the hiPSC-CMs model system coupled with metabolomics technology offers a novel and powerful approach to strengthen cardiac safety assessment during new drug discovery and development. PMID: 28421296 [PubMed - as supplied by publisher]

Systems biology of seeds: deciphering the molecular mechanisms of seed storage, dormancy and onset of germination.

Thu, 20/04/2017 - 12:59
Related Articles Systems biology of seeds: deciphering the molecular mechanisms of seed storage, dormancy and onset of germination. Plant Cell Rep. 2017 Apr 18;: Authors: Sreenivasulu N Abstract Seeds are heterogeneous storage reserves with wide array of storage compounds that include various soluble carbohydrates, starch polymer, storage proteins and lipids. These stored reserves comprise 70% of the world's caloric intake in the form of food and animal feed produced through sustainable agriculture, which contributes to food and nutritional security. Seed systems biology remains an enigmatic subject in understanding seed storage processes, maturation and pre-germinative metabolism. The reviews and research articles covered in this special issue of Plant Cell Reports highlight recent advances made in the area of seed biology that cover various systems biology applications such as gene regulatory networks, metabolomics, epigenetics and the role of micro-RNA in seed development. PMID: 28421280 [PubMed - as supplied by publisher]

Transcriptomic and Metabolomics Profiling of Phage-Host Interactions between Phage PaP1 and Pseudomonas aeruginosa.

Thu, 20/04/2017 - 12:59
Related Articles Transcriptomic and Metabolomics Profiling of Phage-Host Interactions between Phage PaP1 and Pseudomonas aeruginosa. Front Microbiol. 2017;8:548 Authors: Zhao X, Shen M, Jiang X, Shen W, Zhong Q, Yang Y, Tan Y, Agnello M, He X, Hu F, Le S Abstract The basic biology of bacteriophage-host interactions has attracted increasing attention due to a renewed interest in the therapeutic potential of bacteriophages. In addition, knowledge of the host pathways inhibited by phage may provide clues to novel drug targets. However, the effect of phage on bacterial gene expression and metabolism is still poorly understood. In this study, we tracked phage-host interactions by combining transcriptomic and metabolomic analyses in Pseudomonas aeruginosa infected with a lytic bacteriophage, PaP1. Compared with the uninfected host, 7.1% (399/5655) of the genes of the phage-infected host were differentially expressed genes (DEGs); of those, 354 DEGs were downregulated at the late infection phase. Many of the downregulated DEGs were found in amino acid and energy metabolism pathways. Using metabolomics approach, we then analyzed the changes in metabolite levels in the PaP1-infected host compared to un-infected controls. Thymidine was significantly increased in the host after PaP1 infection, results that were further supported by increased expression of a PaP1-encoded thymidylate synthase gene. Furthermore, the intracellular betaine concentration was drastically reduced, whereas choline increased, presumably due to downregulation of the choline-glycine betaine pathway. Interestingly, the choline-glycine betaine pathway is a potential antimicrobial target; previous studies have shown that betB inhibition results in the depletion of betaine and the accumulation of betaine aldehyde, the combination of which is toxic to P. aeruginosa. These results present a detailed description of an example of phage-directed metabolism in P. aeruginosa. Both phage-encoded auxiliary metabolic genes and phage-directed host gene expression may contribute to the metabolic changes observed in the host. PMID: 28421049 [PubMed - in process]

Honeybee gut microbiota promotes host weight gain via bacterial metabolism and hormonal signaling.

Thu, 20/04/2017 - 12:59
Related Articles Honeybee gut microbiota promotes host weight gain via bacterial metabolism and hormonal signaling. Proc Natl Acad Sci U S A. 2017 Apr 18;: Authors: Zheng H, Powell JE, Steele MI, Dietrich C, Moran NA Abstract Social bees harbor a simple and specialized microbiota that is spatially organized into different gut compartments. Recent results on the potential involvement of bee gut communities in pathogen protection and nutritional function have drawn attention to the impact of the microbiota on bee health. However, the contributions of gut microbiota to host physiology have yet to be investigated. Here we show that the gut microbiota promotes weight gain of both whole body and the gut in individual honey bees. This effect is likely mediated by changes in host vitellogenin, insulin signaling, and gustatory response. We found that microbial metabolism markedly reduces gut pH and redox potential through the production of short-chain fatty acids and that the bacteria adjacent to the gut wall form an oxygen gradient within the intestine. The short-chain fatty acid profile contributed by dominant gut species was confirmed in vitro. Furthermore, metabolomic analyses revealed that the gut community has striking impacts on the metabolic profiles of the gut compartments and the hemolymph, suggesting that gut bacteria degrade plant polymers from pollen and that the resulting metabolites contribute to host nutrition. Our results demonstrate how microbial metabolism affects bee growth, hormonal signaling, behavior, and gut physicochemical conditions. These findings indicate that the bee gut microbiota has basic roles similar to those found in some other animals and thus provides a model in studies of host-microbe interactions. PMID: 28420790 [PubMed - as supplied by publisher]

Control of potassium homeostasis is an essential function of the second messenger cyclic di-AMP in Bacillus subtilis.

Thu, 20/04/2017 - 12:59
Related Articles Control of potassium homeostasis is an essential function of the second messenger cyclic di-AMP in Bacillus subtilis. Sci Signal. 2017 Apr 18;10(475): Authors: Gundlach J, Herzberg C, Kaever V, Gunka K, Hoffmann T, Weiß M, Gibhardt J, Thürmer A, Hertel D, Daniel R, Bremer E, Commichau FM, Stülke J Abstract The second messenger cyclic di-adenosine monophosphate (c-di-AMP) is essential in the Gram-positive model organism Bacillus subtilis and in related pathogenic bacteria. It controls the activity of the conserved ydaO riboswitch and of several proteins involved in potassium (K(+)) uptake. We found that the YdaO protein was conserved among several different bacteria and provide evidence that YdaO functions as a K(+) transporter. Thus, we renamed the gene and protein KimA (K(+) importer A). Reporter activity assays indicated that expression beyond the c-di-AMP-responsive riboswitch of the kimA upstream regulatory region occurred only in bacteria grown in medium containing low K(+) concentrations. Furthermore, mass spectrometry analysis indicated that c-di-AMP accumulated in bacteria grown in the presence of high K(+) concentrations but not in low concentrations. A bacterial strain lacking all genes encoding c-di-AMP-synthesizing enzymes was viable when grown in medium containing low K(+) concentrations, but not at higher K(+) concentrations unless it acquired suppressor mutations in the gene encoding the cation exporter NhaK. Thus, our results indicated that the control of potassium homeostasis is an essential function of c-di-AMP. PMID: 28420751 [PubMed - in process]

CK2.1, a bone morphogenetic protein receptor type Ia mimetic peptide, repairs cartilage in mice with destabilized medial meniscus.

Thu, 20/04/2017 - 12:59
Related Articles CK2.1, a bone morphogenetic protein receptor type Ia mimetic peptide, repairs cartilage in mice with destabilized medial meniscus. Stem Cell Res Ther. 2017 Apr 18;8(1):82 Authors: Akkiraju H, Srinivasan PP, Xu X, Jia X, Safran CBK, Nohe A Abstract BACKGROUND: Osteoarthritis (OA) of the knee involves degeneration of articular cartilage of the diarthrodial joints. Current treatment options temporarily relieve the joint pain but do not restore the lost cartilage. We recently designed a novel bone morphogenetic protein receptor type I (BMPRI) mimetic peptide, CK2.1, that activates BMPRIa signaling in the absence of bone morphogenetic protein (BMP). Our previous research demonstrated that CK2.1 induced chondrogenesis in vitro and in vivo; however, it is unknown if CK2.1 restores damaged articular cartilage in vivo. In this study, we demonstrate that CK2.1 induced articular cartilage (AC) repair in an OA mouse model. METHODS: We designed hyaluronic acid (HA)-based hydrogel particles (HGPs) that slowly release CK2.1. HGP-CK2.1 particles were tested for chondrogenic potency on pluripotent mesenchymal stem cells (C3H10T1/2 cells) and locally injected into the intra-articular capsule in mice with cartilage defects. C57BL/6J mice were operated on to destabilize the medial meniscus and these mice were kept for 6 weeks after surgery to sustain OA-like damage. Mice were then injected via the intra-articular capsule with HGP-CK2.1; 4 weeks after injection the mice were sacrificed and their femurs were analyzed for cartilage defects. RESULTS: Immunohistochemical analysis of the cartilage demonstrated complete repair of the AC compared to sham-operated mice. Immunofluorescence analysis revealed collagen type IX production along with collagen type II in the AC of mice injected with HGP-CK2.1. Mice injected with phosphate-buffered saline (PBS) and HGP alone had greater collagen type X and osteocalcin production, in sharp contrast to those injected with HGP-CK2.1, indicating increased chondrocyte hypertrophy. CONCLUSIONS: Our results demonstrate that the slow release HGP-CK2.1 drives cartilage repair without the induction of chondrocyte hypertrophy. The peptide CK2.1 could be a powerful tool in understanding the signaling pathways contributing to the repair process, and also may be used as a potential therapeutic for treating degenerative cartilage diseases such as OA. PMID: 28420447 [PubMed - in process]

Metabolomic Profiling of the Synergistic Effects of Melittin in Combination with Cisplatin on Ovarian Cancer Cells.

Thu, 20/04/2017 - 12:59
Related Articles Metabolomic Profiling of the Synergistic Effects of Melittin in Combination with Cisplatin on Ovarian Cancer Cells. Metabolites. 2017 Apr 14;7(2): Authors: Alonezi S, Tusiimire J, Wallace J, Dufton MJ, Parkinson JA, Young LC, Clements CJ, Park JK, Jeon JW, Ferro VA, Watson DG Abstract Melittin, the main peptide present in bee venom, has been proposed as having potential for anticancer therapy; the addition of melittin to cisplatin, a first line treatment for ovarian cancer, may increase the therapeutic response in cancer treatment via synergy, resulting in improved tolerability, reduced relapse, and decreased drug resistance. Thus, this study was designed to compare the metabolomic effects of melittin in combination with cisplatin in cisplatin-sensitive (A2780) and resistant (A2780CR) ovarian cancer cells. Liquid chromatography (LC) coupled with mass spectrometry (MS) was applied to identify metabolic changes in A2780 (combination treatment 5 μg/mL melittin + 2 μg/mL cisplatin) and A2780CR (combination treatment 2 μg/mL melittin + 10 μg/mL cisplatin) cells. Principal components analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA) multivariate data analysis models were produced using SIMCA-P software. All models displayed good separation between experimental groups and high-quality goodness of fit (R²) and goodness of prediction (Q²), respectively. The combination treatment induced significant changes in both cell lines involving reduction in the levels of metabolites in the tricarboxylic acid (TCA) cycle, oxidative phosphorylation, purine and pyrimidine metabolism, and the arginine/proline pathway. The combination of melittin with cisplatin that targets these pathways had a synergistic effect. The melittin-cisplatin combination had a stronger effect on the A2780 cell line in comparison with the A2780CR cell line. The metabolic effects of melittin and cisplatin in combination were very different from those of each agent alone. PMID: 28420117 [PubMed - in process]

Analysis of Sub-Lethal Toxicity of Perfluorooctane Sulfonate (PFOS) to Daphnia magna Using ¹H Nuclear Magnetic Resonance-Based Metabolomics.

Thu, 20/04/2017 - 12:59
Related Articles Analysis of Sub-Lethal Toxicity of Perfluorooctane Sulfonate (PFOS) to Daphnia magna Using ¹H Nuclear Magnetic Resonance-Based Metabolomics. Metabolites. 2017 Apr 14;7(2): Authors: Kariuki MN, Nagato EG, Lankadurai BP, Simpson AJ, Simpson MJ Abstract ¹H nuclear magnetic resonance (NMR)-based metabolomics was used to characterize the response of Daphnia magna after sub-lethal exposure to perfluorooctane sulfonate (PFOS), a commonly found environmental pollutant in freshwater ecosystems. Principal component analysis (PCA) scores plots showed significant separation in the exposed samples relative to the controls. Partial least squares (PLS) regression analysis revealed a strong linear correlation between the overall metabolic response and PFOS exposure concentration. More detailed analysis showed that the toxic mode of action is metabolite-specific with some metabolites exhibiting a non-monotonic response with higher PFOS exposure concentrations. Our study indicates that PFOS exposure disrupts various energy metabolism pathways and also enhances protein degradation. Overall, we identified several metabolites that are sensitive to PFOS exposure and may be used as bioindicators of D. magna health. In addition, this study also highlights the important utility of environmental metabolomic methods when attempting to elucidate acute and sub-lethal pollutant stressors on keystone organisms such as D. magna. PMID: 28420092 [PubMed - in process]

Skeletal Muscle Nucleo-Mitochondrial Crosstalk in Obesity and Type 2 Diabetes.

Thu, 20/04/2017 - 12:59
Related Articles Skeletal Muscle Nucleo-Mitochondrial Crosstalk in Obesity and Type 2 Diabetes. Int J Mol Sci. 2017 Apr 14;18(4): Authors: Devarshi PP, McNabney SM, Henagan TM Abstract Skeletal muscle mitochondrial dysfunction, evidenced by incomplete beta oxidation and accumulation of fatty acid intermediates in the form of long and medium chain acylcarnitines, may contribute to ectopic lipid deposition and insulin resistance during high fat diet (HFD)-induced obesity. The present review discusses the roles of anterograde and retrograde communication in nucleo-mitochondrial crosstalk that determines skeletal muscle mitochondrial adaptations, specifically alterations in mitochondrial number and function in relation to obesity and insulin resistance. Special emphasis is placed on the effects of high fat diet (HFD) feeding on expression of nuclear-encoded mitochondrial genes (NEMGs) nuclear receptor factor 1 (NRF-1) and 2 (NRF-2) and peroxisome proliferator receptor gamma coactivator 1 alpha (PGC-1α) in the onset and progression of insulin resistance during obesity and how HFD-induced alterations in NEMG expression affect skeletal muscle mitochondrial adaptations in relation to beta oxidation of fatty acids. Finally, the potential ability of acylcarnitines or fatty acid intermediates resulting from mitochondrial beta oxidation to act as retrograde signals in nucleo-mitochondrial crosstalk is reviewed and discussed. PMID: 28420087 [PubMed - in process]

Metabolic profiling reveals new serum biomarkers of lupus nephritis.

Thu, 20/04/2017 - 12:59
Related Articles Metabolic profiling reveals new serum biomarkers of lupus nephritis. Lupus. 2017 Jan 01;:961203317694256 Authors: Li J, Xie XW, Zhou H, Wang B, Zhang MJ, Tang FY Abstract Metabolomics has been applied to explore altered metabolite profiles in disease and identify unique metabolic signatures specific to certain pathologies. The aim of the current study is to characterize the metabolic profile of patients diagnosed with lupus nephritis (LN) and explore new insights into underlying disease processes. A metabolomic approach using ultra-high-performance liquid chromatography coupled with high-resolution mass spectrometry (UPLC-HRMS) was developed in serum samples from 32 LN patients, 30 idiopathic nephrotic syndrome (INS) patients and 28 healthy controls (HCs). Potential biomarkers were screened from orthogonal projection to latent structures discriminate analysis (OPLS-DA) and further evaluated by receiver operating characteristic analysis (ROC). A total of 14 potential biomarkers were screened and tentatively identified for LN patients compared to HCs. Compared to HCs and INS patients, the LN patients had increased serum levels of sorbitol and glycocholic acid metabolites and decreased levels of cortisol, creatinine and L-aspartyl-L-phenylalanine. A panel of three metabolomics (theophylline, oxidized glutathione and capric acid) was identified as biomarkers of LN with a sensitivity of 87.50% and a specificity of 67.86% using ROC analysis. Our results suggest that UPLC-HRMS based quantification of circulating metabolites was a useful tool for identification of biomarkers with the ability to segregate LN patients from INS patients and HCs. The potential biomarkers indicated that the LN metabolic disturbance may be closely associated with inflammation injury, oxidative stress and phospholipid metabolism. PMID: 28420061 [PubMed - as supplied by publisher]

metabolomics; +18 new citations

Wed, 19/04/2017 - 12:39
18 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 2017/04/19PubMed comprises more than millions of 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.

Role of EGF on in situ culture of equine preantral follicles and metabolomics profile.

Tue, 18/04/2017 - 12:05
Role of EGF on in situ culture of equine preantral follicles and metabolomics profile. Res Vet Sci. 2017 Apr 08;115:155-164 Authors: Aguiar FLN, Lunardi FO, Lima LF, Bruno JB, Alves BG, Magalhães-Padilha DM, Cibin FWS, Berioni L, Apgar GA, Lo Turco EG, Gastal EL, Figueiredo JR Abstract The effects of epidermal growth factor (EGF) concentrations (0, 10, 50, and 100ng/ml) on in vitro culture (IVC) of equine preantral follicles were evaluated using histology, estradiol and reactive oxygen species (ROS) production and metabolomics. After IVC, the percentage of normal follicles was lower (P<0.05) for all treatments when compared to non-cultured control. EGF 50ng/ml treatment had more (P<0.05) normal follicles at Day 7 of culture when compared with EGF 0 and 100ng/ml. EGF 50ng/ml had more (P<0.05) developing follicles than the 0ng/ml and 10ng/ml EGF treatments. Follicular and oocyte diameters were greater (P<0.05) with EGF 50ng/ml than the other cultured treatments, but similar (P>0.05) to the non-cultured control. From Day 1 to Day 7 estradiol production increased (P<0.05) in all EGF treatments. EGF 50ng/ml was the only treatment that maintained ROS production through IVC. Metabolomics profiles of the spent media indicated that eleven ions from variable influence in the projection (VIP) scores were higher represented in the EGF 50ng/ml treatment. In conclusion, EGF 50ng/ml treatment maintained follicle survival and ROS production, and promoted activation of cultured equine preantral follicles enclosed in ovarian tissue. PMID: 28414979 [PubMed - as supplied by publisher]

[Pharmacometabonomics - the novel way to personalized drug therapy].

Tue, 18/04/2017 - 12:05
[Pharmacometabonomics - the novel way to personalized drug therapy]. Biomed Khim. 2017 Mar;63(2):115-123 Authors: Maslov DL, Balashova EE, Lokhov PG, Archakov AI Abstract The review is devoted to pharmacometabonomics - a new branch of science focused on personalization of drug therapy through the comprehensive analysis of metabolites of patient's biological fluids. It considers the history of pharmacometabonomic, positioning to other "-omic" sciences, and system approach, realized by this science, in determination of individual therapeutic dose of the drugs and also a technical implementation of pharmacometabonomic based on direct mass spectrometry of blood plasma metabolites. Special attention is paid to a comparative analysis of pharmacometabonomics and other main approaches to personalized therapy in the clinic, such as pharmacogenetics and therapeutic drug monitoring. Finally, prospects of pharmacometabonomics applications in clinical practice were also discussed. PMID: 28414282 [PubMed - in process]

Nuclear magnetic resonance metabolomics and human liver diseases: The principles and evidence associated with protein and carbohydrate metabolism.

Tue, 18/04/2017 - 12:05
Related Articles Nuclear magnetic resonance metabolomics and human liver diseases: The principles and evidence associated with protein and carbohydrate metabolism. Biomed Rep. 2017 Apr;6(4):387-395 Authors: Le Moyec L, Triba MN, Nahon P, Bouchemal N, Hantz E, Goossens C, Amathieu R, Savarin P Abstract During the last decade, metabolomics has become widely used in the field of human diseases. Numerous studies have demonstrated that this is a powerful technique for improving the understanding, diagnosis and management of various types of liver disease, such as acute and chronic liver diseases, and liver transplantation. Nuclear magnetic resonance (NMR) spectroscopy is one of the two most commonly applied methods for metabolomics. The aim of the present review was to investigate the results from recent key publications focusing on aspects of protein and carbohydrate metabolism. The review includes existing procedures, which are currently used for NMR data acquisition and statistical analysis. In addition, notable results obtained by these studies on protein and carbohydrate metabolism concerning human liver diseases are presented. PMID: 28413636 [PubMed - in process]

Discrimination of pancreatic cancer and pancreatitis by LC-MS metabolomics.

Tue, 18/04/2017 - 12:05
Related Articles Discrimination of pancreatic cancer and pancreatitis by LC-MS metabolomics. Metabolomics. 2017;13(5):61 Authors: Lindahl A, Heuchel R, Forshed J, Lehtiö J, Löhr M, Nordström A Abstract INTRODUCTION: Pancreatic ductal adenocarcinoma (PDAC) is the fifth most common cause of cancer-related death in Europe with a 5-year survival rate of <5%. Chronic pancreatitis (CP) is a risk factor for PDAC development, but in the majority of cases malignancy is discovered too late for curative treatment. There is at present no reliable diagnostic marker for PDAC available. OBJECTIVES: The aim of the study was to identify single blood-based metabolites or a panel of metabolites discriminating PDAC and CP using liquid chromatography-mass spectrometry (LC-MS). METHODS: A discovery cohort comprising PDAC (n = 44) and CP (n = 23) samples was analyzed by LC-MS followed by univariate (Student's t test) and multivariate (orthogonal partial least squares-discriminant analysis (OPLS-DA)) statistics. Discriminative metabolite features were subject to raw data examination and identification to ensure high feature quality. Their discriminatory power was then confirmed in an independent validation cohort including PDAC (n = 20) and CP (n = 31) samples. RESULTS: Glycocholic acid, N-palmitoyl glutamic acid and hexanoylcarnitine were identified as single markers discriminating PDAC and CP by univariate analysis. OPLS-DA resulted in a panel of five metabolites including the aforementioned three metabolites as well as phenylacetylglutamine (PAGN) and chenodeoxyglycocholate. CONCLUSION: Using LC-MS-based metabolomics we identified three single metabolites and a five-metabolite panel discriminating PDAC and CP in two independent cohorts. Although further study is needed in larger cohorts, the metabolites identified are potentially of use in PDAC diagnostics. PMID: 28413374 [PubMed - in process]

Membrane potential independent transport of NH3 in the absence of ammonium permeases in Saccharomyces cerevisiae.

Tue, 18/04/2017 - 12:05
Related Articles Membrane potential independent transport of NH3 in the absence of ammonium permeases in Saccharomyces cerevisiae. BMC Syst Biol. 2017 Apr 17;11(1):49 Authors: Cueto-Rojas HF, Milne N, van Helmond W, Pieterse MM, van Maris AJA, Daran JM, Wahl SA Abstract BACKGROUND: Microbial production of nitrogen containing compounds requires a high uptake flux and assimilation of the N-source (commonly ammonium), which is generally coupled with ATP consumption and negatively influences the product yield. In the industrial workhorse Saccharomyces cerevisiae, ammonium (NH4(+)) uptake is facilitated by ammonium permeases (Mep1, Mep2 and Mep3), which transport the NH4(+) ion, resulting in ATP expenditure to maintain the intracellular charge balance and pH by proton export using the plasma membrane-bound H(+)-ATPase. RESULTS: To decrease the ATP costs for nitrogen assimilation, the Mep genes were removed, resulting in a strain unable to uptake the NH4(+) ion. Subsequent analysis revealed that growth of this ∆mep strain was dependent on the extracellular NH3 concentrations. Metabolomic analysis revealed a significantly higher intracellular NHX concentration (3.3-fold) in the ∆mep strain than in the reference strain. Further proteomic analysis revealed significant up-regulation of vacuolar proteases and genes involved in various stress responses. CONCLUSIONS: Our results suggest that the uncharged species, NH3, is able to diffuse into the cell. The measured intracellular/extracellular NHX ratios under aerobic nitrogen-limiting conditions were consistent with this hypothesis when NHx compartmentalization was considered. On the other hand, proteomic analysis indicated a more pronounced N-starvation stress response in the ∆mep strain than in the reference strain, which suggests that the lower biomass yield of the ∆mep strain was related to higher turnover rates of biomass components. PMID: 28412970 [PubMed - in process]

(1)H-NMR analysis of feces: new possibilities in the helminthes infections research.

Tue, 18/04/2017 - 12:05
Related Articles (1)H-NMR analysis of feces: new possibilities in the helminthes infections research. BMC Infect Dis. 2017 Apr 17;17(1):275 Authors: Kostidis S, Kokova D, Dementeva N, Saltykova IV, Kim HK, Choi YH, Mayboroda OA Abstract BACKGROUND: Analysis of the stool samples is an essential part of routine diagnostics of the helminthes infections. However, the standard methods such Kato and Kato-Katz utilize only a fraction of the information available. Here we present a method based on the nuclear magnetic resonance spectroscopy (NMR) which could be auxiliary to the standard procedures by evaluating the complex metabolic profiles (or phenotypes) of the samples. METHOD: The samples were collected over the period of June-July 2015, frozen at -20 °C at the site of collection and transferred within four hours for the permanent storage at -80 °C. Fecal metabolites were extracted by mixing aliquots of about 100 mg thawed stool material with 0.5 mL phosphate buffer saline, followed by the homogenization and centrifugations steps. All NMR data were recorded using a Bruker 600 MHz AVANCE II spectrometer equipped with a 5 mm triple resonance inverse cryoprobe and a z-gradient system. RESULTS: Here we report an optimized method for NMR based metabolic profiling/phenotyping of the stools samples. Overall, 62 metabolites were annotated in the pool sample using the 2D NMR spectra and the Bruker Biorefcode database. The compounds cover a wide range of the metabolome including amino acids and their derivatives, short chain fatty acids (SCFAs), carboxylic acids and their derivatives, amines, carbohydrates, purines, alcohols and others. An exploratory analysis of the metabolic profiles reveals no strong trends associated with the infection status of the patients. However, using the penalized regression as a variable selection method we succeeded in finding a subset of eleven variables which enables to discriminate the patients on basis of their infections status. CONCLUSIONS: A simple method for metabolic profiling/phenotyping of the stools samples is reported and tested on a pilot opisthorchiasis cohort. To our knowledge this is the first report of a NMR-based feces analysis in the context of the helminthic infections. PMID: 28412936 [PubMed - in process]

Genetic variability of the phloem sap metabolite content of maize (Zea mays L.) during the kernel-filling period.

Tue, 18/04/2017 - 12:05
Related Articles Genetic variability of the phloem sap metabolite content of maize (Zea mays L.) during the kernel-filling period. Plant Sci. 2016 Nov;252:347-357 Authors: Yesbergenova-Cuny Z, Dinant S, Martin-Magniette ML, Quilleré I, Armengaud P, Monfalet P, Lea PJ, Hirel B Abstract Using a metabolomic approach, we have quantified the metabolite composition of the phloem sap exudate of seventeen European and American lines of maize that had been previously classified into five main groups on the basis of molecular marker polymorphisms. In addition to sucrose, glutamate and aspartate, which are abundant in the phloem sap of many plant species, large quantities of aconitate and alanine were also found in the phloem sap exudates of maize. Genetic variability of the phloem sap composition was observed in the different maize lines, although there was no obvious relationship between the phloem sap composition and the five previously classified groups. However, following hierarchical clustering analysis there was a clear relationship between two of the subclusters of lines defined on the basis of the composition of the phloem sap exudate and the earliness of silking date. A comparison between the metabolite contents of the ear leaves and the phloem sap exudates of each genotype, revealed that the relative content of most of the carbon- and nitrogen-containing metabolites was similar. Correlation studies performed between the metabolite content of the phloem sap exudates and yield-related traits also revealed that for some carbohydrates such as arabitol and sucrose there was a negative or positive correlation with kernel yield and kernel weight respectively. A posititive correlation was also found between kernel number and soluble histidine. PMID: 27717471 [PubMed - indexed for MEDLINE]

Urinary Metabolic Phenotyping Reveals Differences in the Metabolic Status of Healthy and Inflammatory Bowel Disease (IBD) Children in Relation to Growth and Disease Activity.

Tue, 18/04/2017 - 12:05
Related Articles Urinary Metabolic Phenotyping Reveals Differences in the Metabolic Status of Healthy and Inflammatory Bowel Disease (IBD) Children in Relation to Growth and Disease Activity. Int J Mol Sci. 2016 Aug 11;17(8): Authors: Martin FP, Ezri J, Cominetti O, Da Silva L, Kussmann M, Godin JP, Nydegger A Abstract BACKGROUND: Growth failure and delayed puberty are well known features of children and adolescents with inflammatory bowel disease (IBD), in addition to the chronic course of the disease. Urinary metabonomics was applied in order to better understand metabolic changes between healthy and IBD children. METHODS: 21 Pediatric patients with IBD (mean age 14.8 years, 8 males) were enrolled from the Pediatric Gastroenterology Outpatient Clinic over two years. Clinical and biological data were collected at baseline, 6, and 12 months. 27 healthy children (mean age 12.9 years, 16 males) were assessed at baseline. Urine samples were collected at each visit and subjected to ¹H Nuclear Magnetic Resonance (NMR) spectroscopy. RESULTS: Using ¹H NMR metabonomics, we determined that urine metabolic profiles of IBD children differ significantly from healthy controls. Metabolic differences include central energy metabolism, amino acid, and gut microbial metabolic pathways. The analysis described that combined urinary urea and phenylacetylglutamine-two readouts of nitrogen metabolism-may be relevant to monitor metabolic status in the course of disease. CONCLUSION: Non-invasive sampling of urine followed by metabonomic profiling can elucidate and monitor the metabolic status of children in relation to disease status. Further developments of omic-approaches in pediatric research might deliver novel nutritional and metabolic hypotheses. PMID: 27529220 [PubMed - indexed for MEDLINE]

Elucidation of the complex metabolic profile of cerebrospinal fluid using an untargeted biochemical profiling assay.

Mon, 17/04/2017 - 14:15
Related Articles Elucidation of the complex metabolic profile of cerebrospinal fluid using an untargeted biochemical profiling assay. Mol Genet Metab. 2017 Apr 09;: Authors: Kennedy AD, Pappan KL, Donti TR, Evans AM, Wulff JE, Miller LAD, Reid Sutton V, Sun Q, Miller MJ, Elsea SH Abstract We sought to determine the molecular composition of human cerebrospinal fluid (CSF) and identify the biochemical pathways represented in CSF to understand the potential for untargeted screening of inborn errors of metabolism (IEMs). Biochemical profiles for each sample were obtained using an integrated metabolomics workflow comprised of four chromatographic techniques followed by mass spectrometry. Secondarily, we wanted to compare the biochemical profile of CSF with those of plasma and urine within the integrated mass spectrometric-based metabolomic workflow. Three sample types, CSF (N=30), urine (N=40) and EDTA plasma (N=31), were analyzed from retrospectively collected pediatric cohorts of equivalent age and gender characteristics. We identified 435 biochemicals in CSF representing numerous biological and chemical/structural families. Sixty-three percent (273 of 435) of the biochemicals detected in CSF also were detected in urine and plasma, another 32% (140 of 435) were detected in either plasma or urine, and 5% (22 of 435) were detected only in CSF. Analyses of several metabolites showed agreement between clinically useful assays and the metabolomics approach. An additional set of CSF and plasma samples collected from the same patient revealed correlation between several biochemicals detected in paired samples. Finally, analysis of CSF from a pediatric case with dihydropteridine reductase (DHPR) deficiency demonstrated the utility of untargeted global metabolic phenotyping as a broad assessment to screen samples from patients with undifferentiated phenotypes. The results indicate a single CSF sample processed with an integrated metabolomics workflow can be used to identify a large breadth of biochemicals that could be useful for identifying disrupted metabolic patterns associated with IEMs. PMID: 28412083 [PubMed - as supplied by publisher]

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