PubMed

Related Articles Metabolomics Identifies Biomarker Pattern for Early Diagnosis of Hepatocellular Carcinoma: from Diethylnitrosamine Treated Rats to Patients. Sci Rep. 2015;5:16101 Authors: Zeng J, Huang X, Zhou L, Tan Y, Hu C, Wang X, Niu J, Wang H, Lin X, Yin P Abstract Early diagnosis of hepatocellular carcinoma (HCC) remains challenging to date. Characteristic metabolic deregulations of HCC may enable novel biomarkers discovery for early diagnosis. A capillary electrophoresis-time of flight mass spectrometry (CE-TOF/MS)-based metabolomics approach was performed to discover and validate potential biomarkers for HCC from the diethylnitrosamine-induced rat hepatocarcinogenesis model to human subjects. Time series sera from the animal model were evaluated using multivariate and univariate analyses to reveal dynamic metabolic changes. Two independent human cohorts (populations I and II) containing 122 human serum specimens were enrolled for validations. A novel biomarker pattern of ratio creatine/betaine which reflects the balance of methylation was identified. This biomarker pattern achieved effective classification of pre-HCC and HCC stages in animal model. It was still effective in the diagnosis of HCC from high-risk patients with cirrhotic nodules, achieving AUC values of 0.865 and 0.905 for two validation cohorts, respectively. The diagnosis of small HCC from cirrhosis with an AUC of 0.928 highlighted the potential for early diagnosis. This ratio biomarker can also improve the diagnostic performance of α-fetoprotein (AFP). This study demonstrates the efficacy of present strategy for biomarker discovery, and the potential of metabolomics approach to provide novel insights for disease study. PMID: 26526930 [PubMed - in process]

Related Articles Drug cytotoxicity and signaling pathway analysis with three-dimensional tumor spheroids in a microwell-based microfluidic chip for drug screening. Anal Chim Acta. 2015 Oct 22;898:85-92 Authors: Chen Y, Gao D, Liu H, Lin S, Jiang Y Abstract Currently, there has been a growing need for developing in vitro models to better reflect organism response to chemotherapy at tissue level. For this reason, a microfluidic platform was developed for mimicking physiological microenvironment of solid tumor with multicellular tumor spheroids (MTS) for anticancer drug screening. Importantly, the power of this system over traditional systems is that it is simple to operate and high integration in a more physiologically relevant context. As a proof of concept, long-term MTS cultures with uniform structure were realized on the microfluidic based platform. The response of doxorubicin and paclitaxel on different types of spheroids were simultaneously performed by in situ Live/Dead fluorescence stain to provide spatial distribution of dead cells as well as cytotoxicity information. In addition, the established platform combined with microplate reader was capable to determine the cytotoxicity of different sized MTS, showing a more powerful tool than cell staining examination at the end-point of assay. The HCT116 spheroids were then lysed on chip followed by signaling transduction pathway analysis. To our knowledge, the on chip drug screening study is the first to address the drug susceptibility testing and the offline detailed drug signaling pathway analysis combination on one system. Thus, this novel microfluidic platform provides a useful tool for drug screening with tumor spheroids, which is crucial for drug discovery and development. PMID: 26526913 [PubMed - in process]

Related Articles A novel approach for LC-MS/MS-based chiral metabolomics fingerprinting and chiral metabolomics extraction using a pair of enantiomers of chiral derivatization reagents. Anal Chim Acta. 2015 Oct 22;898:73-84 Authors: Takayama T, Mochizuki T, Todoroki K, Min JZ, Mizuno H, Inoue K, Akatsu H, Noge I, Toyo'oka T Abstract Chiral metabolites are found in a wide variety of living organisms and some of them are understood to be physiologically active compounds and biomarkers. However, the overall analysis of chiral metabolomics is quite difficult due to the high number of metabolites, the significant diversity in their physicochemical properties, and concentration range from metabolite-to-metabolite. To solve this difficulty, we developed a novel approach for chiral metabolomics fingerprinting and chiral metabolomics extraction, which is based on the labeling of a pair of enantiomers of chiral derivatization reagents (i.e., DMT-(S,R)-Pro-OSu and DMT-3(S,R)-Apy) and precursor ion scan chromatography of the derivatives. The multivariate statistics is also required for this strategy. The proposed procedures were evaluated by the detection of a diagnostic marker (i.e., d-lactic acid) using the saliva of diabetic patients. This method was used for the determination of biomarker candidates of chiral amines and carboxyls in Alzheimer's disease (AD) brain homogenates. As the results, l-phenylalanine (L-Phe) and l-lactic acid (L-LA) were identified as the decreased and increased biomarker candidates in the AD brain, respectively. Therefore, the proposed approach seems to be helpful for the determination of non-target chiral metabolomics possessing amines and carboxyls. PMID: 26526912 [PubMed - in process]

Related Articles Quantification of (1)H NMR Spectra from Human Plasma. Metabolomics. 2015 Dec;11(6):1702-1707 Authors: de Graaf RA, Prinsen H, Giannini C, Caprio S, Herzog RI Abstract Human plasma is a biofluid that is high in information content, making it an excellent candidate for metabolomic studies. (1)H NMR has been a popular technique to detect several dozen metabolites in blood plasma. In order for (1)H NMR to become an automated, high-throughput method, challenges related to (1) the large signal from lipoproteins and (2) spectral overlap between different metabolites have to be addressed. Here diffusion-weighted (1)H NMR is used to separate lipoprotein and metabolite signals based on their large difference in translational diffusion. The metabolite (1)H NMR spectrum is then quantified through spectral fitting utilizing full prior knowledge on the metabolite spectral signatures. Extension of the scan time by 3 minutes or 15% per sample allowed the acquisition of a (1)H NMR spectrum with high diffusion weighting. The metabolite (1)H NMR spectra could reliably be modeled with 28 metabolites. Excellent correlation was found between results obtained with diffusion NMR and ultrafiltration. The combination of minimal sample preparation together with minimal user interaction during processing and quantification provides a metabolomics technique for automated, quantitative (1)H NMR of human plasma. PMID: 26526515 [PubMed - as supplied by publisher]

Related Articles Metabolic alterations in the sera of Chinese patients with mild persistent asthma: a GC-MS-based metabolomics analysis. Acta Pharmacol Sin. 2015 Nov;36(11):1356-66 Authors: Chang C, Guo ZG, He B, Yao WZ Abstract AIM: To character the specific metabolomics profiles in the sera of Chinese patients with mild persistent asthma and to explore potential metabolic biomarkers. METHODS: Seventeen Chinese patients with mild persistent asthma and age- and sex-matched healthy controls were enrolled. Serum samples were collected, and serum metabolites were analyzed using GC-MS coupled with a series of multivariate statistical analyses. RESULTS: Clear intergroup separations existed between the asthmatic patients and control subjects. A list of differential metabolites and several top altered metabolic pathways were identified. The levels of succinate (an intermediate in tricarboxylic acid cycle) and inosine were highly upregulated in the asthmatic patients, suggesting a greater effort to breathe during exacerbation and hypoxic stress due to asthma. Other differential metabolites, such as 3,4-dihydroxybenzoic acid and phenylalanine, were also identified. Furthermore, the differential metabolites possessed higher values of area under the ROC curve (AUC), suggesting an excellent clinical ability for the prediction of asthma. CONCLUSION: Metabolic activity is significantly altered in the sera of Chinese patients with mild persistent asthma. The data might be helpful for identifying novel biomarkers and therapeutic targets for asthma. PMID: 26526201 [PubMed - in process]

Related Articles [Metabolome Analysis of Human Serum: Implications for Early Detection of Colorectal Cancer]. Rinsho Byori. 2015 Mar;63(3):328-35 Authors: Yamazaki Y Abstract With the recent development of novel technologies capable of comprehensively detecting and accurately identifying small molecules within biological samples--the field of metabolomics--new information about disease biology is emerging. A comprehensive metabolomics strategy was used to discover novel small molecules which were significantly decreased in the serum of colorectal cancer (CRC) patients relative to normal individuals. The metabolite markers, hydroxylated polyunsaturated ultra long-chain fatty acids (hPULCFAs), were characterized using HPLC-coupled tandem mass spectrometry, and a high-throughput screening (HTS) method compatible with conventional triple-quadrupole mass spectrometers in clinical labs. around the world was developed. The HTS method was used to determine serum levels of the 28 carbon-containing hPULCFA C28H46O4 (named GTA-446) in independent clinical validation studies to investigate the effect of tumor removal after surgery, chemo- or radiation therapy and the correlation with age. We have also obtained results from a two-year prospective trial. Serum samples from a representative cohort of physician-referred colonoscopy subjects (n = 4,923) were collected between July 2008 and August 2010. Ninety-eight new CRC cases were detected in the colonoscopy cohort. Overall sensitivity in this cohort was 85.7%, with 86.5% in the early stage (0-II) and 84.8% in the late-stage (III-IV). This trial represents the first prospective study of this magnitude investigating a metabolic biomarker for CRC. The results indicate that pre-colonoscopy screening using serum GTA-446 levels is a viable approach to detecting early-stage CRC. PMID: 26524856 [PubMed - in process]

Related Articles Accumulation of Glycoconjugates of 3-Methyl-4-hydroxyoctanoic Acid in Fruits, Leaves, and Shoots of Vitis vinifera cv. Monastrell following Foliar Applications of Oak Extract or Oak Lactone. J Agric Food Chem. 2015 May 13;63(18):4533-8 Authors: Pardo-Garcia AI, Wilkinson KL, Culbert JA, Lloyd ND, Alonso GL, Salinas MR Abstract Grapevines are capable of absorbing volatile compounds present in the vineyard during the growing season, and in some cases, volatiles have been found to accumulate in fruits or leaves in glycoconjugate forms, that is, with one or more sugar moieties attached. The presence of oak lactone in wine is usually attributable to oak maturation, but oak lactone has been detected in wines made with fruit from grapevines treated with oak extract or oak lactone. This study investigated the accumulation of glycoconjugates of 3-methyl-4-hydroxyoctanoic acid (i.e., the ring-opened form of oak lactone) in the fruits, leaves, and shoots of Monastrell grapevines following foliar application of either oak extract or oak lactone at approximately 7 days postveraison. Fruits, leaves, and shoots were collected at three different time points, including at maturity. The oak lactone content of fruit was determined by gas chromatography-mass spectrometry, with declining concentrations observed in fruit from grapevines treated with oak lactone with ripening. The concentrations of a β-d-glucopyranoside of 3-methyl-4-hydroxyoctanoic acid in fruits, leaves, and shoots was determined by liquid chromatography-tandem mass spectrometry, with the highest oak lactone glucoside levels observed in leaves of grapevines treated with oak lactone. A glucose-glucose disaccharide was also tentatively identified. These results demonstrate both ring-opening and glycosylation of oak lactone occurred after experimental treatments were imposed. PMID: 25912091 [PubMed - indexed for MEDLINE]

Related Articles Low MITF/AXL ratio predicts early resistance to multiple targeted drugs in melanoma. Nat Commun. 2014;5:5712 Authors: Müller J, Krijgsman O, Tsoi J, Robert L, Hugo W, Song C, Kong X, Possik PA, Cornelissen-Steijger PD, Foppen MH, Kemper K, Goding CR, McDermott U, Blank C, Haanen J, Graeber TG, Ribas A, Lo RS, Peeper DS Abstract Increased expression of the Microphthalmia-associated transcription factor (MITF) contributes to melanoma progression and resistance to BRAF pathway inhibition. Here we show that the lack of MITF is associated with more severe resistance to a range of inhibitors, while its presence is required for robust drug responses. Both in primary and acquired resistance, MITF levels inversely correlate with the expression of several activated receptor tyrosine kinases, most frequently AXL. The MITF-low/AXL-high/drug-resistance phenotype is common among mutant BRAF and NRAS melanoma cell lines. The dichotomous behaviour of MITF in drug response is corroborated in vemurafenib-resistant biopsies, including MITF-high and -low clones in a relapsed patient. Furthermore, drug cocktails containing AXL inhibitor enhance melanoma cell elimination by BRAF or ERK inhibition. Our results demonstrate that a low MITF/AXL ratio predicts early resistance to multiple targeted drugs, and warrant clinical validation of AXL inhibitors to combat resistance of BRAF and NRAS mutant MITF-low melanomas. PMID: 25502142 [PubMed - indexed for MEDLINE]

Related Articles Clinical and non-targeted metabolomic profiling of homozygous carriers of Transcription Factor 7-like 2 variant rs7903146. Sci Rep. 2014;4:5296 Authors: Wagner R, Li J, Kenar E, Kohlbacher O, Machicao F, Häring HU, Fritsche A, Xu G, Lehmann R Abstract An important role of the type 2 diabetes risk variant rs7903146 in TCF7L2 in metabolic actions of various tissues, in particular of the liver, has recently been demonstrated by functional animal studies. Accordingly, the TT diabetes risk allele may lead to currently unknown alterations in human. Our study revealed no differences in the kinetics of glucose, insulin, C-peptide and non-esterified fatty acids during an OGTT in homozygous participants from a German diabetes risk cohort (n = 1832) carrying either the rs7903146 CC (n = 15) or the TT (n = 15) genotype. However, beta-cell function was impaired for TT carriers. Covering more than 4000 metabolite ions the plasma metabolome did not reveal any differences between genotypes. Our study argues against a relevant impact of TCF7L2 rs7903146 on the systemic level in humans, but confirms the role in the pathogenesis of type 2 diabetes in humans as a mechanism impairing insulin secretion. PMID: 24925104 [PubMed - indexed for MEDLINE]

Related Articles Cherry tomatoes metabolic profile determined by ¹H-High Resolution-NMR spectroscopy as influenced by growing season. Food Chem. 2014 Nov 1;162:215-22 Authors: Masetti O, Ciampa A, Nisini L, Valentini M, Sequi P, Dell'Abate MT Abstract The content of the most valuable metabolites present in the lipophilic fraction of Protected Geographical Indication cherry tomatoes produced in Pachino (Italy) was observed for 2 cultivated varieties, i.e. cv. Naomi and cv. Shiren, over a period of 3 years in order to observe variations due to relevant climatic parameters, e.g. solar radiation and average temperature, characterising different seasons. (1)H-NMR spectroscopy was applied and spectral data were processed by means of Principal Component Analysis (PCA). We found that the metabolic profile was different for the two considered cultivated varieties and they were differently affected by climatic conditions. Major metabolites influenced by cropping period were α-tocopherol and the unsaturated lipid fraction in Naomi cherry tomatoes, and chlorophylls and phospholipids in Shiren variety, respectively. These results furnished useful information on seasonal dynamics of such important nutritional metabolites contained in tomatoes, confirming also NMR spectroscopy as powerful tool to define a complete metabolic profiling. PMID: 24874378 [PubMed - indexed for MEDLINE]

Related Articles Impaired metabolic reactivity to oxidative stress in early psychosis patients. Schizophr Bull. 2014 Sep;40(5):973-83 Authors: Fournier M, Ferrari C, Baumann PS, Polari A, Monin A, Bellier-Teichmann T, Wulff J, Pappan KL, Cuenod M, Conus P, Do KQ Abstract Because increasing evidence point to the convergence of environmental and genetic risk factors to drive redox dysregulation in schizophrenia, we aim to clarify whether the metabolic anomalies associated with early psychosis reflect an adaptation to oxidative stress. Metabolomic profiling was performed to characterize the response to oxidative stress in fibroblasts from control individuals (n = 20) and early psychosis patients (n = 30), and in all, 282 metabolites were identified. In addition to the expected redox/antioxidant response, oxidative stress induced a decrease of lysolipid levels in fibroblasts from healthy controls that were largely muted in fibroblasts from patients. Most notably, fibroblasts from patients showed disrupted extracellular matrix- and arginine-related metabolism after oxidative stress, indicating impairments beyond the redox system. Plasma membrane and extracellular matrix, 2 regulators of neuronal activity and plasticity, appeared as particularly susceptible to oxidative stress and thus provide novel mechanistic insights for pathophysiological understanding of early stages of psychosis. Statistically, antipsychotic medication at the time of biopsy was not accounting for these anomalies in the metabolism of patients' fibroblasts, indicating that they might be intrinsic to the disease. Although these results are preliminary and should be confirmed in a larger group of patients, they nevertheless indicate that the metabolic signature of reactivity to oxidative stress may provide reliable early markers of psychosis. Developing protective measures aimed at normalizing the disrupted pathways should prevent the pathological consequences of environmental stressors. PMID: 24687046 [PubMed - indexed for MEDLINE]

Diagnostic approach to breast cancer patients based on target metabolomics in saliva by liquid chromatography with tandem mass spectrometry. Clin Chim Acta. 2015 Oct 30; Authors: Takayama T, Tsutsui H, Shimizu I, Toyama T, Yoshimoto N, Endo Y, Inoue K, Todoroki K, Min JZ, Mizuno H, Toyo'oka T Abstract BACKGROUND: Breast cancer is one of the most fearful diseases due to its increasing worldwide prevalence. A number of screening tests has been employed including clinical examinations and mammography. However, another screening method, which is a simple, not embarrassing, and low cost, is highly desired. Based on these findings, we are currently investigating the determination of polyamines including their acetylated structures for the diagnosis of breast cancer patients. We established a diagnostic approach to breast cancer patients based on the ratios of polyamines in saliva by a UPLC-MS/MS analysis. METHODS: Twelve polyamines including their acetylated form were labeled with DBD-F, separated by a reversed-phase chromatography and detected by a Xevo TQ-S tandem mass spectrometer. RESULTS: Eight polyamines (e.g., SPM, CAD, Ac-SPM, N1-Ac-SPD, N8-Ac-SPD) strongly correlated with the cancer patients. A simple 1-order equation was developed for the discrimination of the breast cancer patients and healthy persons (Y=0.5XSPM-3XAc-SPM-0.15XSPD-3.5XN8-Ac-SPD+0.5XN1-Ac-SPD+0.04XCAD). The concordance rate of the breast cancer patients and the healthy persons by the equation was 88% and 76% on the training set, respectively, whereas those on the validation set was both 88%. The score Y in the equation tended to correlate with the cancer stage of the patients and increased with the more serious conditions. The determination of polyamines in the saliva after the cancer patient operations was also performed to identify the concentration change before and after the surgical treatment. The discriminant analysis using 6 polyamines (i.e., N8-Ac-SPD, N1-Ac-SPD, CAD, DAc-SPD, PUT, and Ac-PUT), which were the most influenced molecules derived from the ROC analysis, was performed using the relative percentage. Both the sensitivity and specificity indicated nearly 80% from the ROC analysis result using the ratio of N8-Ac-SPD/(N1-Ac-SPD+N8-Ac-SPD). CONCLUSION: The discrimination equation appears to be useful for the diagnosis of breast cancer patients. Furthermore, the ratio of N8-Ac-SPD/(N1-Ac-SPD+N8-Ac-SPD) may be adopted as an index of the health status after the surgical treatment. PMID: 26523874 [PubMed - as supplied by publisher]

Cell-based screens and phenomics with fission yeast. Crit Rev Biochem Mol Biol. 2015 Nov 2;:1-10 Authors: Rallis C, Bähler J Abstract Next-generation sequencing approaches have considerably advanced our understanding of genome function and regulation. However, the knowledge of gene function and complex cellular processes remains a challenge and bottleneck in biological research. Phenomics is a rapidly emerging area, which seeks to rigorously characterize all phenotypes associated with genes or gene variants. Such high-throughput phenotyping under different conditions can be a potent approach toward gene function. The fission yeast Schizosaccharomyces pombe (S. pombe) is a proven eukaryotic model organism that is increasingly used for genomewide screens and phenomic assays. In this review, we highlight current large-scale, cell-based approaches used with S. pombe, including computational colony-growth measurements, genetic interaction screens, parallel profiling using barcodes, microscopy-based cell profiling, metabolomic methods and transposon mutagenesis. These diverse methods are starting to offer rich insights into the relationship between genotypes and phenotypes. PMID: 26523839 [PubMed - as supplied by publisher]

Chicken, beams, and Campylobacter: rapid differentiation of foodborne bacteria via vibrational spectroscopy and MALDI-mass spectrometry. Analyst. 2015 Nov 2; Authors: Muhamadali H, Weaver D, Subaihi A, AlMasoud N, Trivedi DK, Ellis DI, Linton D, Goodacre R Abstract Campylobacter species are one of the main causes of food poisoning worldwide. Despite the availability of established culturing and molecular techniques, due to the fastidious nature of these microorganisms, simultaneous detection and species differentiation still remains challenging. This study focused on the differentiation of eleven Campylobacter strains from six species, using Fourier transform infrared (FT-IR) and Raman spectroscopies, together with matrix-assisted laser desorption ionisation-time of flight-mass spectrometry (MALDI-TOF-MS), as physicochemical approaches for generating biochemical fingerprints. Cluster analysis of data from each of the three analytical approaches provided clear differentiation of each Campylobacter species, which was generally in agreement with a phylogenetic tree based on 16S rRNA gene sequences. Notably, although C. fetus subspecies fetus and venerealis are phylogenetically very closely related, using FT-IR and MALDI-TOF-MS data these subspecies were readily differentiated based on differences in the lipid (2920 and 2851 cm(-1)) and fingerprint regions (1500-500 cm(-1)) of the FT-IR spectra, and the 500-2000 m/z region of the MALDI-TOF-MS data. A finding that was further investigated with targeted lipidomics using liquid chromatography-mass spectrometry (LC-MS). Our results demonstrate that such metabolomics approaches combined with molecular biology techniques may provide critical information and knowledge related to the risk factors, virulence, and understanding of the distribution and transmission routes associated with different strains of foodborne Campylobacter spp. PMID: 26523729 [PubMed - as supplied by publisher]

Systemic differences in serum metabolome: a cross sectional comparison of women with localised and widespread pain and controls. Sci Rep. 2015;5:15925 Authors: Hadrévi J, Björklund M, Kosek E, Hällgren S, Antti H, Fahlström M, Hellström F Abstract Chronic musculoskeletal pain exists either as localised to a single region or as widespread to multiple sites in several quadrants of the body. Prospective studies indicate that widespread pain could act as a far end of a continuum of musculoskeletal pain that started with chronic localised pain. The mechanism by which the transition from localised pain to widespread occurs is not clear, although many studies suggest it to be an altered metabolism. In this study, systemic metabolic differences between women with chronic localised neck-shoulder pain (NP), women with chronic widespread pain (CWP) and women who were healthy (CON) were assessed. Blood samples were analysed taking a metabolomics approach using gas chromatography mass spectrometry (GC-MS) and orthogonal partial least square discriminant analysis (OPLS-DA). The metabolomics analysis showed a clear systematic difference in the metabolic profiles between the subjects with NP and the CON but only a weak systematic difference between the subjects with CWP and the CON. This most likely reflects a difference in the portion of the metabolome influenced by the two pain conditions. In the NP group, the overall metabolic profile suggests that processes related to energy utilisation and lipid metabolism could be central aspects of mechanisms maintaining disorder. PMID: 26522699 [PubMed - in process]

Identification of elevated urea as a severe, ubiquitous metabolic defect in the brain of patients with Huntington's disease. Biochem Biophys Res Commun. 2015 Oct 29; Authors: Patassini S, Begley P, Reid SJ, Xu J, Church SJ, Curtis M, Dragunow M, Waldvogel HJ, Unwin RD, Snell RG, Faull RL, Cooper GJ Abstract Huntington's disease (HD) is a neurodegenerative disorder wherein the aetiological defect is a mutation in the Huntington's gene (HTT), which alters the structure of the huntingtin protein through the lengthening of a polyglutamine tract and initiates a cascade that ultimately leads to dementia and premature death. However, neurodegeneration typically manifests in HD only in middle age, and processes linking the causative mutation to brain disease are poorly understood. Here, our objective was to elucidate further the processes that cause neurodegeneration in HD, by measuring levels of metabolites in brain regions known to undergo varying degrees of damage. We applied gas-chromatography/mass spectrometry-based metabolomics in a case-control study of eleven brain regions in short post-mortem-delay human tissue from nine well-characterized HD patients and nine controls. Unexpectedly, a single major abnormality was evident in all eleven brain regions studied across the forebrain, midbrain and hindbrain, namely marked elevation of urea, a metabolite formed in the urea cycle by arginase-mediated cleavage of arginine. Urea cycle activity localizes primarily in the liver, where it functions to incorporate protein-derived amine-nitrogen into urea for recycling or urinary excretion. It also occurs in other cell-types, but systemic over-production of urea is not known in HD. These findings are consistent with impaired local urea regulation in brain, by up-regulation of synthesis and/or defective clearance. We hypothesize that defective brain urea metabolism could play a substantive role in the pathogenesis of neurodegeneration, perhaps via defects in osmoregulation or nitrogen metabolism. Brain urea metabolism is therefore a target for generating novel monitoring/imaging strategies and/or therapeutic interventions aimed at ameliorating the impact of HD in patients. PMID: 26522227 [PubMed - as supplied by publisher]

Clostridium difficile secreted Pro-Pro endopeptidase PPEP-1 (ZMP1/CD2830) modulates adhesion through cleavage of the collagen binding protein CD2831. FEBS Lett. 2015 Oct 29; Authors: Hensbergen PJ, Klychnikov OI, Bakker D, Dragan I, Kelly ML, Minton NP, Corver J, Kuijper EJ, Drijfhout JW, van Leeuwen HC Abstract The Clostridium difficile cd2830 gene product is a secreted metalloprotease, named Pro-Pro endopeptidase (PPEP-1). PPEP-1 cleaves C. difficile cell surface proteins (e.g. CD2831). Here, we confirmed that PPEP-1 has a unique preference for prolines surrounding the scissile bond. Moreover, we show that it exhibits a high preference for an asparagine at the P2 position and hydrophobic residues at the P3 position. Using a PPEP-1 knockout C. difficile strain, we demonstrate that the removal of the collagen binding protein CD2831 is fully attributable to PPEP-1 activity. The PPEP-1 knockout strain demonstrated higher affinity for collagen type I with attenuated virulence in hamsters. PMID: 26522134 [PubMed - as supplied by publisher]

Identification of novel candidate plasma metabolite biomarkers for distinguishing serous ovarian carcinoma and benign serous ovarian tumors. Gynecol Oncol. 2015 Oct 29; Authors: Buas MF, Gu H, Djukovic D, Zhu J, Drescher CW, Urban N, Raftery D, Li CI Abstract OBJECTIVE: Serous ovarian carcinoma (OC) represents a leading cause of cancer-related death among U.S women. Non-invasive tools have recently emerged for discriminating benign from malignant ovarian masses, but evaluation remains ongoing, without widespread implementation. In the last decade, metabolomics has matured into a new avenue for cancer biomarker development. Here, we sought to identify novel plasma metabolite biomarkers to distinguish serous ovarian carcinoma and benign ovarian tumor. METHODS: Using liquid chromatography-mass spectrometry, we conducted global and targeted metabolite profiling of plasma isolated at the time of surgery from 50 serous OC cases and 50 serous benign controls. RESULTS: Global lipidomics analysis identified 34 metabolites (of 372 assessed) differing significantly (P<0.05) between cases and controls in both training and testing sets, with 17 candidates satisfying FDR q<0.05, and two reaching Bonferroni significance. Targeted profiling of ~150 aqueous metabolites identified a single amino acid, alanine, as differentially abundant (P<0.05). A multivariate classification model built using the top four lipid metabolites achieved an estimated AUC of 0.85 (SD=0.07) based on Monte Carlo cross validation. Evaluation of a hybrid model incorporating both CA125 and lipid metabolites was suggestive of increased classification accuracy (AUC=0.91, SD=0.05) relative to CA125 alone (AUC=0.87, SD=0.07), particularly at high fixed levels of sensitivity, without reaching significance. CONCLUSIONS: Our results provide insight into metabolic changes potentially correlated with the presence of serous OC versus benign ovarian tumor and suggest that plasma metabolites may help differentiate these two conditions. PMID: 26521694 [PubMed - as supplied by publisher]

[Metabolomics study of doxorubicin induced hepatotoxicity]. Yao Xue Xue Bao. 2015 Jun;50(6):708-13 Authors: Niu QY, Liu YT, Li ZY, Qin XM Abstract To reveal the underlying mechanism of doxorubicin induced hepatotoxicity, an NMR-based metabolomic approach combined with multivariate statistical analysis was used to observe its metabolic alternations of rat liver. Sixteen differential metabolites between model rats and normal rats were characterized as potential pathological biomarkers related to doxorubicin induced hepatotoxicity. Six pathways, including phenylalanine, tyrosine and tryptophan biosynthesis, valine, leucine and isoleucine biosynthesis, phenylalanine metabolism, glycine, serine and threonine metabolism, alanine, aspartate and glutamate metabolism, and tyrosine metabolism were regarded as the targeted metabolic pathways according to Metabolic Pathway Analysis (MetPA). The results suggested that the metabolic perturbations in rats with doxorubicin induced hepatotoxicity were mainly involved in amino acid metabolism, lipid pathways, purine metabolism, energy metabolism, dysfunction of biotransformation and oxidative stress. The investigation revealed the effects of doxorubicin on liver in a holistic metabolic way, which laid a foundation for further studies on its toxicity mechanism. PMID: 26521441 [PubMed - in process]

Related Articles Metabolic profiling reveals altered sugar and secondary metabolism in response to UGPase overexpression in Populus. BMC Plant Biol. 2014;14:265 Authors: Payyavula RS, Tschaplinski TJ, Jawdy SS, Sykes RW, Tuskan GA, Kalluri UC Abstract BACKGROUND: UDP-glucose pyrophosphorylase (UGPase) is a sugar-metabolizing enzyme (E.C. 2.7.7.9) that catalyzes a reversible reaction of UDP-glucose and pyrophosphate from glucose-1-phosphate and UTP. UDP-glucose is a key intermediate sugar that is channeled to multiple metabolic pathways. The functional role of UGPase in perennial woody plants is poorly understood. RESULTS: We characterized the functional role of a UGPase gene in Populus deltoides, PdUGPase2. Overexpression of the native gene resulted in increased leaf area and leaf-to-shoot biomass ratio but decreased shoot and root growth. Metabolomic analyses showed that manipulation of PdUGPase2 results in perturbations in primary, as well as secondary metabolism, resulting in reduced sugar and starch levels and increased phenolics, such as caffeoyl and feruloyl conjugates. While cellulose and lignin levels in the cell walls were not significantly altered, the syringyl-to-guaiacyl ratio was significantly reduced. CONCLUSIONS: These results demonstrate that PdUGPase2 plays a key role in the tightly coupled primary and secondary metabolic pathways and perturbation in its function results in pronounced effects on growth and metabolism beyond cell wall biosynthesis of Populus. PMID: 25287590 [PubMed - indexed for MEDLINE]