PubMed

Diverse Serum Manganese Species affect Brain Metabolites depending on Exposure Conditions. Chem Res Toxicol. 2015 May 29; Authors: Neth K, Lucio M, Walker A, Kanawati B, Zorn J, Schmitt-Kopplin P, Michalke B Abstract Occupational and environmental exposure to increased concentrations of Manganese (Mn) can lead to an accumulation of this element in the brain. The consequence is an irreversible damage of dopaminergic neurons leading to a disease called manganism with a clinical presentation similar to the one observed in Parkinson´s Disease. Human as well as animal studies indicate that Mn is mainly bound to low molecular mass (LMM) compounds such as Mn-citrate when crossing neural barriers. The shift towards LMM compounds might already take place in serum due to elevated Mn concentrations in the body.In this study we investigated Mn-species pattern in serum in two different animal models by size exclusion chromatography-inductively coupled plasma mass spectrometry (SEC-ICP-MS). A subchronic feeding of rats with elevated levels of Mn led to an increase in LMM compounds, mainly Mn-citrate and Mn bound to amino acids. In addition, a single i.v. injection of Mn showed an increase in Mn-transferrin and Mn bound to amino acids one hour after injection, while species values were rebalanced four days after the injection. Results from Mn-speciation were correlated to the brain metabolome determined by means of electrospray ionization ion cyclotron resonance Fourier transform mass spectrometry (ESI-ICR/FT-MS). The powerful combination of Mn-speciation in serum with metabolomics of the brain underlined the need for Mn-speciation in exposure scenarios instead of determination of whole Mn concentrations in blood. The progress of Mn-induced neuronal inflammation might therefore be assessed on basis of known serum Mn-species. PMID: 26024413 [PubMed - as supplied by publisher]

The Dilemma of Heterogeneity Tests in Meta-Analysis: A Challenge from a Simulation Study. PLoS One. 2015;10(5):e0127538 Authors: Li SJ, Jiang H, Yang H, Chen W, Peng J, Sun MW, Lu CD, Peng X, Zeng J Abstract INTRODUCTION: After several decades' development, meta-analysis has become the pillar of evidence-based medicine. However, heterogeneity is still the threat to the validity and quality of such studies. Currently, Q and its descendant I2 (I square) tests are widely used as the tools for heterogeneity evaluation. The core mission of this kind of test is to identify data sets from similar populations and exclude those are from different populations. Although Q and I2 are used as the default tool for heterogeneity testing, the work we present here demonstrates that the robustness of these two tools is questionable. METHODS AND FINDINGS: We simulated a strictly normalized population S. The simulation successfully represents randomized control trial data sets, which fits perfectly with the theoretical distribution (experimental group: p = 0.37, control group: p = 0.88). And we randomly generate research samples Si that fits the population with tiny distributions. In short, these data sets are perfect and can be seen as completely homogeneous data from the exactly same population. If Q and I2 are truly robust tools, the Q and I2 testing results on our simulated data sets should not be positive. We then synthesized these trials by using fixed model. Pooled results indicated that the mean difference (MD) corresponds highly with the true values, and the 95% confidence interval (CI) is narrow. But, when the number of trials and sample size of trials enrolled in the meta-analysis are substantially increased; the Q and I2 values also increase steadily. This result indicates that I2 and Q are only suitable for testing heterogeneity amongst small sample size trials, and are not adoptable when the sample sizes and the number of trials increase substantially. CONCLUSIONS: Every day, meta-analysis studies which contain flawed data analysis are emerging and passed on to clinical practitioners as "updated evidence". Using this kind of evidence that contain heterogeneous data sets leads to wrong conclusion, makes chaos in clinical practice and weakens the foundation of evidence-based medicine. We suggest more strict applications of meta-analysis: it should only be applied to those synthesized trials with small sample sizes. We call upon that the tools of evidence-based medicine should keep up-to-dated with the cutting-edge technologies in data science. Clinical research data should be made available publicly when there is any relevant article published so the research community could conduct in-depth data mining, which is a better alternative for meta-analysis in many instances. PMID: 26023932 [PubMed - as supplied by publisher]

Metabolomics Reveals that Aryl Hydrocarbon Receptor Activation by Environmental Chemicals Induces Systemic Metabolic Dysfunction in Mice. Environ Sci Technol. 2015 May 29; Authors: Zhang L, Hatzakis E, Nichols RG, Hao R, Correll JB, Smith PB, Chiaro CR, Perdew GH, Patterson AD Abstract Environmental exposure to dioxins and dioxin-like compounds poses a significant health risk for human health. Developing a better understanding of the mechanisms of toxicity through activation of the aryl hydrocarbon receptor (AHR) is likely to improve the reliability of risk assessment. In this study, the AHR-dependent metabolic responses of mice exposed to 2,3,7,8-tetrachlorodibenzofuran (TCDF) were assessed using global 1H nuclear magnetic resonance (NMR)-based metabolomics and targeted metabolic profiling of extracts obtained from serum and liver. 1H NMR analyses revealed that TCDF exposure suppressed gluconeogenesis and glycogenolysis, stimulated lipogenesis, and triggered inflammatory gene expression in an Ahr-dependent manner. Targeted analyses using gas chromatography mass spectrometry showed TCDF treatment altered the ratio of unsaturated/saturated fatty acids. Consistent with this observation, an increase in hepatic expression of stearoyl coenzyme A desaturase 1 was also observed. In addition, TCDF exposure resulted in inhibition of de novo fatty acid biosynthesis manifested by down-regulation of acetyl-CoA, malonyl-CoA and palmitoyl-CoA metabolites and related mRNA levels. In contrast, no significant changes in the levels of glucose and lipid were observed in serum and liver obtained from Ahr-null mice following TCDF treatment, thus strongly supporting the important role of the AHR in mediating the metabolic effects seen following TCDF exposure. PMID: 26023891 [PubMed - as supplied by publisher]

Quantification of folate metabolism using transient metabolic flux analysis. Cancer Metab. 2015;3:6 Authors: Tedeschi PM, Johnson-Farley N, Lin H, Shelton LM, Ooga T, Mackay G, Van Den Broek N, Bertino JR, Vazquez A Abstract BACKGROUND: Systematic quantitative methodologies are needed to understand the heterogeneity of cell metabolism across cell types in normal physiology, disease, and treatment. Metabolic flux analysis (MFA) can be used to infer steady state fluxes, but it does not apply for transient dynamics. Kinetic flux profiling (KFP) can be used in the context of transient dynamics, and it is the current gold standard. However, KFP requires measurements at several time points, limiting its use in high-throughput applications. RESULTS: Here we propose transient MFA (tMFA) as a cost-effective methodology to quantify metabolic fluxes using metabolomics and isotope tracing. tMFA exploits the time scale separation between the dynamics of different metabolites to obtain mathematical equations relating metabolic fluxes to metabolite concentrations and isotope fractions. We show that the isotope fractions of serine and glycine are at steady state 8 h after addition of a tracer, while those of purines and glutathione are following a transient dynamics with an approximately constant turnover rate per unit of metabolite, supporting the application of tMFA to the analysis of folate metabolism. Using tMFA, we investigate the heterogeneity of folate metabolism and the response to the antifolate methotrexate in breast cancer cells. Our analysis indicates that methotrexate not only inhibits purine synthesis but also induces an increase in the AMP/ATP ratio, activation of AMP kinase (AMPK), and the inhibition of protein and glutathione synthesis. We also find that in some cancer cells, the generation of one-carbon units from serine exceeds the biosynthetic demand. CONCLUSIONS: This work validates tMFA as a cost-effective methodology to investigate cell metabolism. Using tMFA, we have shown that the effects of treatment with the antifolate methotrexate extend beyond inhibition of purine synthesis and propagate to other pathways in central metabolism. PMID: 26023330 [PubMed]

Signaling through the Phosphatidylinositol 3-Kinase (PI3K)/ Mammalian Target of Rapamycin (mTOR) Axis is Responsible for Aerobic Glycolysis mediated by Glucose Transporter in Epidermal Growth Factor Receptor (EGFR)-mutated Lung Adenocarcinoma. J Biol Chem. 2015 May 28; Authors: Makinoshima H, Takita M, Saruwatari K, Umemura S, Obata Y, Ishii G, Matsumoto S, Sugiyama E, Ochiai A, Abe R, Goto K, Esumi H, Tsuchihara K Abstract Oncogenic epidermal growth factor receptor (EGFR) signaling plays an important role in regulating global metabolic pathways including aerobic glycolysis, the pentose phosphate pathway (PPP) and pyrimidine biosynthesis.　However, the molecular mechanism by which EGFR signaling regulates cancer cell metabolism is still unclear. To elucidate how EGFR signaling is linked to metabolic activity, we investigated the involvement of the RAS/MEK/ERK and PI3K/AKT/mTOR pathways on metabolic alteration in lung adenocarcinoma (LAD) cell lines with activating EGFR mutations. Although MEK inhibition did not alter lactate production and the extracellular acidification rate (ECAR), PI3K/mTOR inhibitors significantly suppressed glycolysis in EGFR-mutant LAD cells. Moreover, comprehensive metabolomics analysis revealed that the levels of glucose 6-phosphate (G6P) and 6-phosphogluconate (6PG) as early metabolites in glycolysis and PPP were decreased after inhibition of the PI3K/AKT/mTOR pathway, suggesting a linkage between PI3K signaling and the proper function of glucose transporters or hexokinases in glycolysis. Indeed, PI3K/mTOR inhibition effectively suppressed membrane localization of facilitative glucose transporter 1 (GLUT1), which instead accumulated in the cytoplasm. Finally, aerobic glycolysis and cell proliferation were down-regulated when GLUT1 gene expression　was suppressed　by RNA interference (RNAi). Taken together, these results suggest that PI3K/AKT/mTOR signaling is indispensable for the regulation of aerobic glycolysis in EGFR-mutated LAD cells. PMID: 26023239 [PubMed - as supplied by publisher]

Identification of regulatory network hubs that control lipid metabolism in Chlamydomonas reinhardtii. J Exp Bot. 2015 May 28; Authors: Gargouri M, Park JJ, Holguin FO, Kim MJ, Wang H, Deshpande RR, Shachar-Hill Y, Hicks LM, Gang DR Abstract Microalgae-based biofuels are promising sources of alternative energy, but improvements throughout the production process are required to establish them as economically feasible. One of the most influential improvements would be a significant increase in lipid yields, which could be achieved by altering the regulation of lipid biosynthesis and accumulation. Chlamydomonas reinhardtii accumulates oil (triacylglycerols, TAG) in response to nitrogen (N) deprivation. Although a few important regulatory genes have been identified that are involved in controlling this process, a global understanding of the larger regulatory network has not been developed. In order to uncover this network in this species, a combined omics (transcriptomic, proteomic and metabolomic) analysis was applied to cells grown in a time course experiment after a shift from N-replete to N-depleted conditions. Changes in transcript and protein levels of 414 predicted transcription factors (TFs) and transcriptional regulators (TRs) were monitored relative to other genes. The TF and TR genes were thus classified by two separate measures: up-regulated versus down-regulated and early response versus late response relative to two phases of polar lipid synthesis (before and after TAG biosynthesis initiation). Lipidomic and primary metabolite profiling generated compound accumulation levels that were integrated with the transcript dataset and TF profiling to produce a transcriptional regulatory network. Evaluation of this proposed regulatory network led to the identification of several regulatory hubs that control many aspects of cellular metabolism, from N assimilation and metabolism, to central metabolism, photosynthesis and lipid metabolism. PMID: 26022256 [PubMed - as supplied by publisher]

Fungal sterol C22-desaturase is not an antimycotic target as shown by selective inhibitors and testing on clinical isolates. Steroids. 2015 May 25; Authors: Müller C, Binder U, Maurer E, Grimm C, Giera M, Bracher F Abstract Inhibition of concise enzymes in ergosterol biosynthesis is one of the most prominent strategies for antifungal chemotherapy. Nevertheless, the enzymes sterol C5-desaturase and sterol C22-desaturase, which introduce double bonds into the sterol core and side chain, have not been fully investigated yet for their potential as antifungal drug targets. Lathosterol side chain amides bearing N-alkyl groups of proper length are known as potent inhibitors of the enzymes sterol C5-desaturase and sterol Δ(24)-reductase in mammalian cholesterol biosynthesis. Here we present the results of our evaluation of these amides for their ability to inhibit enzymes in fungal ergosterol biosynthesis. In the presence of inhibitor(s) an accumulation of sterols lacking a double bond at C22/23 (mainly ergosta-5,7-dien-3β-ol) was observed in Candida glabrata, Saccharomyces cerevisiae, and Yarrowia lipolytica. Hence, the lathosterol side chain amides were identified as selective inhibitors of the fungal sterol C22-desaturase, which was discussed as a specific target for novel antifungals. One representative inhibitor, (3S,20S)-20-N-butylcarbamoylpregn-7-en-3β-ol) was subjected to antifungal susceptibility testing on patient isolates according to modified EUCAST guidelines. But, the test organisms showed no significant reduction of cell growth and/or viability up to an inhibitor concentration of 100 μg/mL. This leads to the conclusion that sterol C22-desaturase is not an attractive target for the development of antifungals. PMID: 26022150 [PubMed - as supplied by publisher]

Related Articles Quantitative analysis of purine nucleotides indicates that purinosomes increase de novo purine biosynthesis. J Biol Chem. 2015 Mar 13;290(11):6705-13 Authors: Zhao H, Chiaro CR, Zhang L, Smith PB, Chan CY, Pedley AM, Pugh RJ, French JB, Patterson AD, Benkovic SJ Abstract Enzymes in the de novo purine biosynthesis pathway are recruited to form a dynamic metabolic complex referred to as the purinosome. Previous studies have demonstrated that purinosome assembly responds to purine levels in culture medium. Purine-depleted medium or 2-dimethylamino-4,5,6,7-tetrabromo-1H-benzimidazole (DMAT) treatment stimulates the purinosome assembly in HeLa cells. Here, several metabolomic technologies were applied to quantify the static cellular levels of purine nucleotides and measure the de novo biosynthesis rate of IMP, AMP, and GMP. Direct comparison of purinosome-rich cells (cultured in purine-depleted medium) and normal cells showed a 3-fold increase in IMP concentration in purinosome-rich cells and similar levels of AMP, GMP, and ratios of AMP/GMP and ATP/ADP for both. In addition, a higher level of IMP was also observed in HeLa cells treated with DMAT. Furthermore, increases in the de novo IMP/AMP/GMP biosynthetic flux rate under purine-depleted condition were observed. The synthetic enzymes, adenylosuccinate synthase (ADSS) and inosine monophosphate dehydrogenase (IMPDH), downstream of IMP were also shown to be part of the purinosome. Collectively, these results provide further evidence that purinosome assembly is directly related to activated de novo purine biosynthesis, consistent with the functionality of the purinosome. PMID: 25605736 [PubMed - indexed for MEDLINE]

Related Articles Exploring metabolic pathways and regulation through functional chemoproteomic and metabolomic platforms. Chem Biol. 2014 Sep 18;21(9):1171-84 Authors: Medina-Cleghorn D, Nomura DK Abstract Genome sequencing efforts have revealed a strikingly large number of uncharacterized genes, including poorly or uncharacterized metabolic enzymes, metabolites, and metabolic networks that operate in normal physiology, and those enzymes and pathways that may be rewired under pathological conditions. Although deciphering the functions of the uncharacterized metabolic genome is a challenging prospect, it also presents an opportunity for identifying novel metabolic nodes that may be important in disease therapy. In this review, we will discuss the chemoproteomic and metabolomic platforms used in identifying, characterizing, and targeting nodal metabolic pathways important in physiology and disease, describing an integrated workflow for functional mapping of metabolic enzymes. PMID: 25237861 [PubMed - indexed for MEDLINE]

Related Articles Integrated metabolic flux and omics analysis of Synechocystis sp. PCC 6803 under mixotrophic and photoheterotrophic conditions. Plant Cell Physiol. 2014 Sep;55(9):1605-12 Authors: Nakajima T, Kajihata S, Yoshikawa K, Matsuda F, Furusawa C, Hirasawa T, Shimizu H Abstract Cyanobacteria have flexible metabolic capability that enables them to adapt to various environments. To investigate their underlying metabolic regulation mechanisms, we performed an integrated analysis of metabolic flux using transcriptomic and metabolomic data of a cyanobacterium Synechocystis sp. PCC 6803, under mixotrophic and photoheterotrophic conditions. The integrated analysis indicated drastic metabolic flux changes, with much smaller changes in gene expression levels and metabolite concentrations between the conditions, suggesting that the flux change was not caused mainly by the expression levels of the corresponding genes. Under photoheterotrophic conditions, created by the addition of the photosynthesis inhibitor atrazine in mixotrophic conditions, the result of metabolic flux analysis indicated the significant repression of carbon fixation and the activation of the oxidative pentose phosphate pathway (PPP). Moreover, we observed gluconeogenic activity of upstream of glycolysis, which enhanced the flux of the oxidative PPP to compensate for NADPH depletion due to the inhibition of the light reaction of photosynthesis. 'Omics' data suggested that these changes were probably caused by the repression of the gap1 gene, which functions as a control valve in the metabolic network. Since metabolic flux is the outcome of a complicated interplay of cellular components, integrating metabolic flux with other 'omics' layers can identify metabolic changes and narrow down these regulatory mechanisms more effectively. PMID: 24969233 [PubMed - indexed for MEDLINE]

Related Articles Similar metabolic changes induced by HIPVs exposure as herbivore in Ammopiptanthus mongolicus. PLoS One. 2014;9(4):e95474 Authors: Sun J, Zhang X, Cao C, Mei X, Wang N, Yan S, Zong S, Luo Y, Yang H, Shen Y Abstract Herbivore-induced plant volatiles (HIPVs) are important compounds to prim neighboring undamaged plants; however, the mechanism for this priming process remains unclear. To reveal metabolic changes in plants exposed to HIPVs, metabolism of leaves and roots of Ammopiptanthus mongolicus seedlings exposed to HIPVs released from conspecific plants infested with larvae of Orgyia ericae were analyzed together with control and infested seedlings using nuclear magnetic resonance (NMR)-based metabolic technology and multi variate data analysis. Results presented showed that HIPVs exposure led to similar but specific metabolic changes compared with those induced by infestation in both leaves and roots. Furthermore, both HIPVs exposure and herbivore attack resulted in metabolic changes involving a series of primary and secondary metabolites in both leaves and roots. Taken together, these results suggested that priming of yet-damaged plants may be achieved by reconfiguring metabolic pathways in leaves and roots to make similar concentrations for all metabolites as those in seedlings infested. Therefore, we propose that improved readiness of defense induction of primed plants toward subsequent herbivore attack may be based on the similar metabolic profiling induced by HIPVs exposure as those caused by herbivore. PMID: 24748156 [PubMed - indexed for MEDLINE]

Related Articles Metabolomic analysis of cooperative adaptation between co-cultured Bacillus cereus and Ketogulonicigenium vulgare. PLoS One. 2014;9(4):e94889 Authors: Ding MZ, Zou Y, Song H, Yuan YJ Abstract The cooperative adaptation of subcultivated Bacillus cereus and Ketogulonicigenium vulgare significantly increased the productivity of 2-keto-L-gulonic acid, the precursor of vitamin C. The mechanism of cooperative adaptation of the serial subcultivated B. cereus and K. vulgare was investigated in this study by culturing the two strains orthogonally on agar plates. It was found that the swarming distance of B. cereus along the trace of K. vulgare on the plate decreased after 150 days' subcultivation. Metabolomic analysis on these co-cultured B. cereus and K. vulgare strains showed that their cooperative adaptation was accomplished by three key events: (i) the ability of nutrients (e.g., amino acids and purines) searching and intaking, and proteins biosynthesis is increased in the evolved B. cereus; (ii) the capability of protein degradation and amino acids transportation is enhanced in evolved K. vulgare; (iii) the evolved B. cereus was found to provide more nutrients (mostly amino acids and purines) to K. vulgare, thus strengthening the oxidation and energy generation of K. vulgare. Our results provided novel insights into the systems-level understanding of the cooperative adaptation between strains in synergistic consortium. PMID: 24728527 [PubMed - indexed for MEDLINE]

Related Articles A metabonomic analysis of serum from rats treated with ricinine using ultra performance liquid chromatography coupled with mass spectrometry. PLoS One. 2014;9(3):e90416 Authors: Peng J, Cai S, Wang L, Zhao N, Zhang TJ, Chen ZX, Meng FH Abstract A metabonomic approach based on ultra performance liquid chromatography coupled with mass spectrometry (UPLC/MS) was used to study the hepatotoxicity of ricinine in rats. Potential biomarkers of ricinine toxicity and toxicological mechanism were analyzed by serum metabonomic method. The significant differences in the metabolic profiling of the control and treated rats were clear by using the principal components analysis (PCA) of the chromatographic data. Significant changes of metabolite biomarkers like phenylalanine, tryptophan, cholic acid, LPC and PC were detected in the serum. These biochemical changes were related to the metabolic disorders in amino acids and phospholipids. This research indicates that UPLC/MS-based metabonomic analysis of serum samples can be used to predict the hepatotoxicity and further understand the toxicological mechanism induced by ricinine. This work shows that metabonomics method is a valuable tool in drug mechanism study. PMID: 24618672 [PubMed - indexed for MEDLINE]

Related Articles Controlling for confounding variables in MS-omics protocol: why modularity matters. Brief Bioinform. 2014 Sep;15(5):768-70 Authors: Smith R, Ventura D, Prince JT Abstract As the field of bioinformatics research continues to grow, more and more novel techniques are proposed to meet new challenges and improvements upon solutions to long-standing problems. These include data processing techniques and wet lab protocol techniques. Although the literature is consistently thorough in experimental detail and variable-controlling rigor for wet lab protocol techniques, bioinformatics techniques tend to be less described and less controlled. As the validation or rejection of hypotheses rests on the experiment's ability to isolate and measure a variable of interest, we urge the importance of reducing confounding variables in bioinformatics techniques during mass spectrometry experimentation. PMID: 23894105 [PubMed - indexed for MEDLINE]

21 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 2015/05/29PubMed 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.

Systems biology and metabolic modelling unveils limitations to polyhydroxybutyrate accumulation in sugarcane leaves; lessons for C4 engineering. Plant Biotechnol J. 2015 May 25; Authors: McQualter RB, Bellasio C, Gebbie LK, Petrasovits LA, Palfreyman RW, Hodson MP, Plan MR, Blackman DM, Brumbley SM, Nielsen LK Abstract In planta production of the bioplastic polyhydroxybutyrate (PHB) is one important way in which plant biotechnology can address environmental problems and emerging issues related to peak oil. However, high biomass C4 plants such as maize, switch grass and sugarcane develop adverse phenotypes including stunting, chlorosis and reduced biomass as PHB levels in leaves increase. In this study, we explore limitations to PHB accumulation in sugarcane chloroplasts using a systems biology approach, coupled with a metabolic model of C4 photosynthesis. Decreased assimilation was evident in high PHB-producing sugarcane plants, which also showed a dramatic decrease in sucrose and starch content of leaves. A subtle decrease in the C/N ratio was found which was not associated with a decrease in total protein content. An increase in amino acids used for nitrogen recapture was also observed. Based on the accumulation of substrates of ATP-dependent reactions, we hypothesized ATP starvation in bundle sheath chloroplasts. This was supported by mRNA differential expression patterns. The disruption in ATP supply in bundle sheath cells appears to be linked to the physical presence of the PHB polymer which may disrupt photosynthesis by scattering photosynthetically active radiation and/or physically disrupting thylakoid membranes. PMID: 26015295 [PubMed - as supplied by publisher]

Hsp70 and the Co-Chaperone StiA (Hop) Orchestrate Hsp90-Mediated Caspofungin Tolerance in Aspergillus fumigatus. Antimicrob Agents Chemother. 2015 May 26; Authors: Lamoth F, Juvvadi PR, Soderblom EJ, Moseley MA, Steinbach WJ Abstract Aspergillus fumigatus is the primary etiologic agent of invasive aspergillosis (IA), a major cause of death among immunosuppressed patients. Echinocandins (e.g. caspofungin) are increasingly used as second-line therapy for IA, but their activity is only fungistatic. The heat shock protein 90 (Hsp90) was previously shown to trigger tolerance to caspofungin and the paradoxical effect (i.e. decreased efficacy of caspofungin at higher concentrations). Here, we demonstrate the key role of another molecular chaperone, Hsp70, in governing the stress response to caspofungin via Hsp90 and their co-chaperone Hop/Sti1 (StiA in A. fumigatus). Mutation of the StiA-interacting domain of Hsp70 (C-terminal EELD motif) impaired thermal adaptation and caspofungin tolerance with loss of the caspofungin paradoxical effect. Impaired Hsp90 function and increased susceptibility to caspofungin was also observed following pharmacologic inhibition of the C-terminal domain of Hsp70 by pifithrin-μ or after stiA deletion, further supporting the link between Hsp70, StiA and Hsp90 in governing caspofungin tolerance. StiA was not required for the physical interaction between Hsp70 and Hsp90, but had distinct roles in regulating their function in caspofungin and heat stress responses. In conclusion, this study deciphering the physical and functional interactions of the Hsp70-StiA-Hsp90 complex provides new insights into the mechanisms of tolerance to caspofungin in A. fumigatus and revealed a key C-terminal motif of Hsp70, which can be targeted by specific inhibitors, such as pifithrin-μ, to enhance caspofungin antifungal activity against A. fumigatus. PMID: 26014950 [PubMed - as supplied by publisher]

Innovation in metabolomics to improve personalized healthcare. Ann N Y Acad Sci. 2015 May 26; Authors: Cacciatore S, Loda M Abstract Metabolomics is the systemic study of all small molecules (metabolites) and their concentration as affected by pathological and physiological alterations or environmental or other factors. Metabolic alterations represent a "window" on the complex interactions between genetic expression, enzyme activity, and metabolic reactions. Techniques, including nuclear magnetic resonance spectroscopy, mass spectrometry, Fourier-transform infrared, and Raman spectroscopy, have led to significant advances in metabolomics. The field is shifting from feasibility studies to biological and clinical applications. Fields of application range from cancer biology to stem cell research and assessment of xenobiotics and drugs in tissues and single cells. Cross-validation across high-throughput platforms has allowed findings from expression profiling to be confirmed with metabolomics. Specific genetic alterations appear to drive unique metabolic programs. These, in turn, can be used as biomarkers of genetic subtypes of prostate cancer or as discovery tools for therapeutic targeting of metabolic enzymes. Thus, metabolites in blood may serve as biomarkers of tumor state, including inferring driving oncogenes. Novel applications such as these suggest that metabolic profiling may be utilized in refining personalized medicine. PMID: 26014591 [PubMed - as supplied by publisher]

Brain metabolomics in rats after administration of ketamine. Biomed Chromatogr. 2015 May 26; Authors: Wen C, Zhang M, Zhang Y, Sun F, Ma J, Hu L, Lin G, Wang X Abstract In this study, we developed a brain metabolomic method, based on gas chromatography-mass spectrometry (GC/MS), to evaluate the effect of ketamine on rats. Pattern recognition analysis, including both principal component analysis (PCA) and partial least squares-discriminate analysis (PLS-DA) revealed that ketamine induced metabolic perturbations. Compared to the control group, the level of glycerol, uridine, cholesterol in rat brain of the ketamine group (50 mg/kg, 14 days) decreased, while the urea levels increased. Our results indicate that metabolomic methods based on GC/MS may be useful to elucidate ketamine abuse through the exploration of biomarkers. PMID: 26014584 [PubMed - as supplied by publisher]

Metabolomic analysis of wild and transgenic Nicotiana langsdorffii plants exposed to abiotic stresses: unraveling metabolic responses. Anal Bioanal Chem. 2015 May 27; Authors: Scalabrin E, Radaelli M, Rizzato G, Bogani P, Buiatti M, Gambaro A, Capodaglio G Abstract Nicotiana langsdorffii plants, wild and transgenic for the Agrobacterium rhizogenes rol C gene and the rat glucocorticoid receptor (GR) gene, were exposed to different abiotic stresses (high temperature, water deficit, and high chromium concentrations). An untargeted metabolomic analysis was carried out in order to investigate the metabolic effects of the inserted genes in response to the applied stresses and to obtain a comprehensive profiling of metabolites induced during abiotic stresses. High-performance liquid chromatography separation (HPLC) coupled to high-resolution mass spectrometry (HRMS) enabled the identification of more than 200 metabolites, and statistical analysis highlighted the most relevant compounds for each plant treatment. The plants exposed to heat stress showed a unique set of induced secondary metabolites, some of which were known while others were not previously reported for this kind of stress; significant changes were observed especially in lipid composition. The role of trichome, as a protection against heat stress, is here suggested by the induction of both acylsugars and glykoalkaloids. Water deficit and Cr(VI) stresses resulted mainly in enhanced antioxidant (HCAs, polyamine) levels and in the damage of lipids, probably as a consequence of reactive oxygen species (ROS) production. Moreover, the ability of rol C expression to prevent oxidative burst was confirmed. The results highlighted a clear influence of GR modification on plant stress response, especially to water deficiency-a phenomenon whose applications should be further investigated. This study provides new insights into the field of system biology and demonstrates the importance of metabolomics in the study of plant functioning. Graphical Abstract Untargeted metabolomic analysis was applied to wild type, GR and RolC modified Nicotiana Langsdorffii plants exposed to heat, water and Cr(VI) stresses. The key metabolites, highly affected by stress application, were identified, allowing to outline the main metabolic responses to stress in each plant genotype. PMID: 26014284 [PubMed - as supplied by publisher]