PubMed

Wildtype motoneurons, ALS-Linked SOD1 mutation and glutamate profoundly modify astrocyte metabolism and lactate shuttling. Glia. 2017 Jan 31;: Authors: Madji Hounoum B, Mavel S, Coque E, Patin F, Vourc'h P, Marouillat S, Nadal-Desbarats L, Emond P, Corcia P, Andres CR, Raoul C, Blasco H Abstract The selective degeneration of motoneuron that typifies amyotrophic lateral sclerosis (ALS) implicates non-cell-autonomous effects of astrocytes. However, mechanisms underlying astrocyte-mediated neurotoxicity remain largely unknown. According to the determinant role of astrocyte metabolism in supporting neuronal function, we propose to explore the metabolic status of astrocytes exposed to ALS-associated conditions. We found a significant metabolic dysregulation including purine, pyrimidine, lysine, and glycerophospholipid metabolism pathways in astrocytes expressing an ALS-causing mutated superoxide dismutase-1 (SOD1) when co-cultured with motoneurons. SOD1 astrocytes exposed to glutamate revealed a significant modification of the astrocyte metabolic fingerprint. More importantly, we observed that SOD1 mutation and glutamate impact the cellular shuttling of lactate between astrocytes and motoneurons with a decreased in extra- and intra-cellular lactate levels in astrocytes. Based on the emergent strategy of metabolomics, this work provides novel insight for understanding metabolic dysfunction of astrocytes in ALS conditions and opens the perspective of therapeutics targets through focusing on these metabolic pathways. GLIA 2017. PMID: 28139855 [PubMed - as supplied by publisher]

A Metabolome-Wide Study of Dry Eye Disease Reveals Serum Androgens as Biomarkers. Ophthalmology. 2017 Jan 28;: Authors: Vehof J, Hysi PG, Hammond CJ Abstract PURPOSE: To test the association between serum metabolites and dry eye disease (DED) using a hypothesis-free metabolomics approach. DESIGN: Cross-sectional association study. PARTICIPANTS: A total of 2819 subjects from the population-representative TwinsUK cohort in the United Kingdom, with a mean age of 57 years (range, 17-82 years). METHODS: We tested associations between 222 known serum metabolites and DED. All subjects underwent nontargeted metabolomic analysis of plasma samples using gas and liquid chromatography in combination with mass spectrometry (Metabolon Inc., Durham, NC). Dry eye disease was defined from the validated Short Questionnaire for Dry Eye Syndrome (SQDES) as a previous diagnosis of DED by a clinician or "often" or "constant" symptoms of dryness and irritation. Analyses were performed with linear mixed effect models that included age, BMI, and sex as covariates, corrected for multiple testing. MAIN OUTCOME MEASURES: Primary outcome was DED as defined by the SQDES, and secondary outcomes were symptom score of DED and a clinical diagnosis of DED. RESULTS: Prevalence of DED as defined by the SQDES was 15.5% (n = 436). A strong and metabolome-wide significant association with DED was found with decreased levels of the metabolites androsterone sulfate (P = 0.00030) and epiandrosterone sulfate (P = 0.00036). Three other metabolites involved in androgen metabolism, 4-androsten-3beta,17beta-diol disulfate 1 and 2, and dehydroepiandrosterone sulfate, were the next most strongly associated of the 222 metabolites, but did not reach metabolome-wide significance. Dryness and irritation symptoms, as opposed to a clinical diagnosis, were particularly strongly associated with decreased androgen steroid metabolites, with all reaching metabolome-wide significance (androsterone sulfate, P = 0.000000029; epiandrosterone sulfate, P = 0.0000040; 4-androsten-3beta,17beta-diol disulfate 1, P = 0.000016; 4-androsten-3beta,17beta-diol disulfate 2, P = 0.000064; and dehydroepiandrosterone sulfate, P = 0.00011). Of these 5 androgens, epiandrosterone sulfate (P = 0.0076) was most associated with 2-year incidence of clinician-diagnosed DED. In addition, we found decreased glycerophosphocholines to be associated with DED, although not at metabolome-wide significance. CONCLUSIONS: This hypothesis-free metabolomic approach found decreased serum androgens to be highly associated with DED and adds important evidence to the growing body of research that links androgens to ocular surface disease and DED. PMID: 28139245 [PubMed - as supplied by publisher]

Chiral separation of short chain aliphatic hydroxycarboxylic acids on cinchonan carbamate-based weak chiral anion exchangers and zwitterionic chiral ion exchangers. J Chromatogr A. 2017 Jan 24;: Authors: Calderón C, Lämmerhofer M Abstract Chiral short chain aliphatic hydrocarboxylic acids (HCAs) are common compounds being part of different biological processes. In order to control and understand these processes is of pivotal importance to determine the identity of the involved enantiomer or their enantiomeric ratio. In this study the capacity of quinine- and quinidine-derived chiral stationary phases to perform the enantioseparation of eight chiral HCAs (tartaric acid, isocitric acid, malic acid, glyceric acid, 2-hydroxyglutaric acid, 2-hydroxybutyric acid, lactic acid and 3-hydroxybutyric acid) was evaluated. MS-compatible conditions consisting of ACN/MeOH mixtures as eluents with formic acid, acetic acid and/or their ammonium salts as additives, temperatures between 10 and 25°C (except for -20°C for 3-hydroxybutyric acid) and a flow rate of 1.00mL/min yielded full baseline resolution for all studied HCAs. Elution order for the HCA enantiomers was determined revealing different behaviors between the studied compounds. PMID: 28139228 [PubMed - as supplied by publisher]

The effects of graded levels of calorie restriction: IX. Global metabolomic screen reveals modulation of carnitines, sphingolipids and bile acids in the liver of C57BL/6 mice. Aging Cell. 2017 Jan 31;: Authors: Green CL, Mitchell SE, Derous D, Wang Y, Chen L, Han JJ, Promislow DE, Lusseau D, Douglas A, Speakman JR Abstract Calorie restriction (CR) remains the most robust intervention to extend lifespan and improve health span. Using a global mass spectrometry-based metabolomic approach, we identified 193 metabolites that were significantly differentially expressed (SDE) in the livers of C57BL/6 mice, fed graded levels of CR (10, 20, 30 and 40% CR) compared to mice fed ad libitum for 12 h a day. The differential expression of metabolites also varied with the different feeding groups. Pathway analysis revealed that graded CR had an impact on carnitine synthesis and the carnitine shuttle pathway, sphingosine-1-phosphate (S1P) signalling and methionine metabolism. S1P, sphingomyelin and L-carnitine were negatively correlated with body mass, leptin, insulin-like growth factor- 1 (IGF-1) and major urinary proteins (MUPs). In addition, metabolites which showed a graded effect, such as ceramide, S1P, taurocholic acid and L-carnitine, responded in the opposite direction to previously observed age-related changes. We suggest that the modulation of this set of metabolites may improve liver processes involved in energy release from fatty acids. S1P also negatively correlated with catalase activity and body temperature, and positively correlated with food anticipatory activity. Injecting mice with S1P or an S1P receptor 1 agonist did not precipitate changes in body temperature, physical activity or food intake suggesting that these correlations were not causal relationships. PMID: 28139067 [PubMed - as supplied by publisher]

Amino Acid Profiles of Serum and Urine in Search for Prostate Cancer Biomarkers: a Pilot Study. Int J Med Sci. 2017;14(1):1-12 Authors: Dereziński P, Klupczynska A, Sawicki W, Pałka JA, Kokot ZJ Abstract There is a great interest in searching for diagnostic biomarkers in prostate cancer patients. The aim of the pilot study was to evaluate free amino acid profiles in their serum and urine. The presented paper shows the first comprehensive analysis of a wide panel of amino acids in two different physiological fluids obtained from the same groups of prostate cancer patients (n = 49) and healthy men (n = 40). The potential of free amino acids, both proteinogenic and non-proteinogenic, as prostate cancer biomarkers and their utility in classification of study participants have been assessed. Several metabolites, which deserve special attention in the further metabolomic investigations on searching for prostate cancer markers, were indicated. Moreover, free amino acid profiles enabled to classify samples to one of the studied groups with high sensitivity and specificity. The presented research provides a strong evidence that ethanolamine, arginine and branched-chain amino acids metabolic pathways can be a valuable source of markers for prostate cancer. The altered concentrations of the above-mentioned metabolites suggest their role in pathogenesis of prostate cancer and they should be further evaluated as clinically useful markers of prostate cancer. PMID: 28138303 [PubMed - in process]

Comparative Effects of LY3020371, a Potent and Selective mGlu2/3 Receptor Antagonist, and Ketamine, a Non-Competitive NMDA Receptor Antagonist, in Rodents: Evidence Supporting Use for the Treatment of Depression. J Pharmacol Exp Ther. 2017 Jan 30;: Authors: Witkin JM, Mitchell S, Wafford K, Carter G, Gilmour G, Li J, Eastwood B, Overshiner C, Li X, Rorick-Kehn L, Rasmussen K, Anderson W, Nikolayev A, Tolstikov V, Kuo MS, Catlow J, Li R, Smith S, Mitch C, Ornstein P, Swanson S, Monn J Abstract The ability of the NMDA receptor antagonist ketamine to alleviate symptoms in patients suffering from treatment resistant depression (TRD) is well documented. In this report, we directly compare in vivo biological responses in rodents elicited by a recently discovered mGlu2/3 receptor antagonist (LY3020371) with those produced by ketamine. Both LY3020371 and ketamine increased the number of spontaneously active DA cells in the ventral tegmental area of anesthetized rats, increased O2 in the anterior cingulate cortex, promoted wakefulness, enhanced the efflux of biogenic amines in the prefrontal cortex, and produced antidepressant-related behavioral effects in SSRI-sensitive and -insensitive rodent models. The ability of LY3020371 to produce antidepressant-like effects in the forced-swim assay in rats was associated with cerebral spinal fluid (CSF) drug levels that matched concentrations required for functional antagonist activity in native rat brain tissue preparations. Metabolomic pathway analyses from analytes recovered from rat CSF and hippocampus demonstrated that both LY3020371 and ketamine activated common pathways involving GRIA2 and ADORA1. A diester analog of LY3020371 (LY3027788) was an effective oral prodrug; when given orally, it recapitulated effects of intravenous doses of LY3020371 in the forced-swim and wake-promotion assays, and augmented the antidepressant-like effects of fluoxetine or citalopram without altering plasma or brain levels of these compounds. The broad overlap of biological responses produced by LY3020371 and ketamine supports the hypothesis that mGlu2/3 receptor blockade might be a novel therapeutic approach for the treatment of TRD patients. LY3020371 and LY3027788 represent molecules that are ready for clinical test of this hypothesis. PMID: 28138040 [PubMed - as supplied by publisher]

The effects of liraglutide in mice with diet-induced obesity studied by metabolomics. J Endocrinol. 2017 Jan 30;: Authors: Buganova M, Pelantova H, Holubova M, Sediva B, Maletinska L, Zelezna B, Kunes J, Kacer P, Kuzma M, Haluzik M Abstract Liraglutide is the glucagon-like peptide-1 receptor agonist widely used for the treatment of type 2 diabetes mellitus. Recently, it has been demonstrated to decrease cardiovascular morbidity and mortality in patients with type 2 diabetes and high cardiovascular risk. While the major modes of liraglutide action are well-known, its detailed action at the metabolic level has not been studied. To this end, we explored the effect of 2-week liraglutide treatment in C57BL/6 male mice with obesity and diabetes induced by 13 weeks of high-fat diet using NMR spectroscopy to capture the changes in urine metabolic profile induced by the therapy. The liraglutide treatment decreased body and fat pads weight along with blood glucose and triglyceride levels. NMR spectroscopy identified 11 metabolites significantly affected by liraglutide treatment as compared to high-fat diet-fed control group. These metabolites included ones involved in nicotinamide adenine dinucleotide metabolism, β-oxidation of fatty acids and microbiome changes. While majority of the metabolites changed after liraglutide treatment were similar as the ones previously identified after vildagliptin administration in a similar mouse model, the changes in creatinine, taurine and trigonelline were specific for liraglutide administration. The significance of these changes and its possible use in the personalization of antidiabetic therapy in humans requires further research. PMID: 28138003 [PubMed - as supplied by publisher]

Sparse network modeling and Metscape-based visualization methods for the analysis of large-scale metabolomics data. Bioinformatics. 2017 Jan 30;: Authors: Basu S, Duren W, Evans CR, Burant CF, Michailidis G, Karnovsky A Abstract MOTIVATION: Recent technological advances in mass spectrometry, development of richer mass spectral libraries and data processing tools have enabled large scale metabolic profiling. Biological interpretation of metabolomics studies heavily relies on knowledge-based tools that contain information about metabolic pathways. Incomplete coverage of different areas of metabolism and lack of information about non-canonical connections between metabolites limits the scope of applications of such tools. Furthermore, the presence of a large number of unknown features, which cannot be readily identified, but nonetheless can represent bona fide compounds, also considerably complicates biological interpretation of the data. RESULTS: Leveraging recent developments in the statistical analysis of high-dimensional data, we developed a new Debiased Sparse Partial Correlation algorithm (DSPC) for estimating partial correlation networks and implemented it as a Java-based CorrelationCalculator program. We also introduce a new version of our previously developed tool Metscape that enables building and visualization of correlation networks. We demonstrate the utility of these tools by constructing biologically relevant networks and in aiding identification of unknown compounds. AVAILABILITY: http://metscape.med.umich.eduSupplementary information: Supplementary data are available at Bioinformatics online. PMID: 28137712 [PubMed - as supplied by publisher]

Metabolomics in the Diagnosis and Pharmacotherapy of Lung Diseases. Curr Pharm Des. 2017 Jan 30; Authors: Devillier P, Salvator H, Naline E, Couderc LJ, Grassin-Delyle S Abstract Metabolomics is of the increasing interests in medical research and the study of respiratory diseases. This novel type of small molecule analysis can be performed not only on conventional biological samples such as plasma or urine but also on sputum, bronchoalveolar fluid, exhaled breath condensate or exhaled breath itself (which is particularly relevant for research on respiratory diseases). On one hand, powerful analytical methodologies (including mass spectrometry and nuclear magnetic resonance spectroscopy) are labour-intensive but enable the exhaustive identification of metabolites. On the other hand, electronic noses can be used for exhaled breath analysis. Although the latter devices do not contain metabolite-specific sensors, they produce a condition- or treatment-specific "breathprint" based on pattern recognition. Breath analysis with electronic noses is non-invasive, and can be performed at the bedside in real time. Here, we review the literature on metabolomics studies in respiratory medicine, with a focus on the evaluation of responses to pharmacotherapy. PMID: 28137216 [PubMed - as supplied by publisher]

Related Articles Metabolomic Approach for Discrimination of Four- and Six-Year-Old Red Ginseng (Panax ginseng) Using UPLC-QToF-MS. Chem Pharm Bull (Tokyo). 2016 Sep 01;64(9):1298-303 Authors: Shin JS, Park HW, In G, Seo HK, Won TH, Jang KH, Cho BG, Han CK, Shin J Abstract Panax ginseng C.A. MEYER is one of the most popular medicinal herbs in Asia and the chemical constituents are changed by processing methods such as steaming or sun drying. Metabolomic analysis was performed to distinguish age discrimination of four- and six-year-old red ginseng using ultra-performance liquid chromatography quadruple time of flight mass spectrometry (UPLC-QToF-MS) with multivariate statistical analysis. Principal component analysis (PCA) showed clear discrimination between extracts of red ginseng of different ages and suggest totally six discrimination markers (two for four-year-old and four for six-year-old red ginseng). Among these, one marker was isolated and the structure determined by NMR spectroscopic analysis was 13-cis-docosenamide (marker 6-1) from six-year-old red ginseng. This is the first report of a metabolomic study regarding the age differentiation of red ginseng using UPLC-QToF-MS and determination of the structure of the marker. These results will contribute to the quality control and standardization as well as provide a scientific basis for pharmacological research on red ginseng. PMID: 27383266 [PubMed - indexed for MEDLINE]

Related Articles Metabonomic changes from pancreatic intraepithelial neoplasia to pancreatic ductal adenocarcinoma in tissues from rats. Cancer Sci. 2016 Jun;107(6):836-45 Authors: Wen S, Li Z, Feng J, Bai J, Lin X, Huang H Abstract Pancreatic ductal adenocarcinoma (PDAC) is one of the most malignant tumors and is difficult to diagnose in the early phase. This study was aimed at obtaining the metabolic profiles and characteristic metabolites of pancreatic intraepithelial neoplasia (PanIN) and PDAC tissues from Sprague-Dawley (SD) rats to establish metabonomic methods used in the early diagnosis of PDAC. In the present study, the animal models were established by embedding 7,12-dimethylbenzanthracene (DMBA) in the pancreas of SD rats to obtain PanIN and PDAC tissues. After the preprocessing of tissues, (1) H nuclear magnetic resonance (NMR) spectroscopy combined with multivariate and univariate statistical analysis was applied to identify the potential metabolic signatures and the corresponding metabolic pathways. Pattern recognition models were successfully established and differential metabolites, including glucose, amino acids, carboxylic acids and coenzymes, were screened out. Compared with the control, the trends in the variation of several metabolites were similar in both PanIN and PDAC. Kynurenate and methionine levels were elevated in PanIN but decreased in PDAC, thus, could served as biomarkers to distinguish PanIN from PDAC. Our results suggest that NMR-based techniques combined with multivariate statistical analysis can distinguish the metabolic differences among PanIN, PDAC and normal tissues, and, therefore, present a promising approach for physiopathologic metabolism investigations and early diagnoses of PDAC. PMID: 27019331 [PubMed - indexed for MEDLINE]

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Related Articles (1)H NMR-based metabolomics reveals sub-lethal toxicity of a mixture of diabetic and lipid-regulating pharmaceuticals on amphibian larvae. Aquat Toxicol. 2017 Jan 23;184:123-132 Authors: Melvin SD, Habener LJ, Leusch FD, Carroll AR Abstract Pharmaceuticals are widely used for the treatment of various physical and psychological ailments. Due to incomplete removal during sewage treatment many pharmaceuticals are frequently detected in aquatic waterways at trace concentrations. The diversity of pharmaceutical contaminants and potential for complex mixtures to occur makes it very difficult to predict the toxicity of these compounds on wildlife, and robust methods are therefore needed to explore sub-lethal effects. Metabolic syndrome is one of the most widespread health concerns currently facing the human population, and various drugs, including anti-diabetic medications and lipid- and cholesterol-lowering fibrates and statins, are widely prescribed as treatment. In this study, we exposed striped marsh frog (Limnodynastes peronii) tadpoles to a mixture of the drugs metformin, atorvastatin and bezafibrate at 0.5, 5, 50 and 500μg/L to explore possible effects on growth and development, energy reserves (triglycerides and cholesterol), and profiles of small polar metabolites extracted from hepatic tissues. It was hypothesised that exposure would result in a general reduction in energy reserves, and that this would subsequently correspond with reduced growth and development. Responses differed from expected outcomes based on the known mechanisms of these compounds in humans, with no changes to hepatic triglycerides or cholesterol and a general increase in mass and condition with increasing exposure concentration. Deviation from the expected response patterns may be explained by differences in the receptivity or uptake of the compounds in non-mammalian species. Proton nuclear magnetic resonance ((1)H NMR) spectroscopy revealed evidence of broad metabolic dysregulation in exposed animals, and possible interaction between the solvent and mixture. Specifically, increased lactic acid and branched-chain amino acids were observed, with responses tending to follow a non-monotonic pattern. Overall, results demonstrate that a mixture of drugs commonly prescribed to treat human metabolic syndrome is capable of eliciting physiological and developmental effects on larval amphibians. Importantly, outcomes further suggest that it may not be possible to predict toxicological effects in non-target wildlife based on our knowledge of how these compounds act in humans. PMID: 28131079 [PubMed - as supplied by publisher]

Related Articles Constitutive heterologous overexpression of a TIR-NB-ARC-LRR gene encoding a putative disease resistance protein from wild Chinese Vitis pseudoreticulata in Arabidopsis and tobacco enhances resistance to phytopathogenic fungi and bacteria. Plant Physiol Biochem. 2017 Jan 17;112:346-361 Authors: Wen Z, Yao L, Singer SD, Muhammad H, Li Z, Wang X Abstract Plants use resistance (R) proteins to detect pathogen effector proteins and activate their innate immune response against the pathogen. The majority of these proteins contain an NB-ARC (nucleotide-binding adaptor shared by APAF-1, R proteins, and CED-4) domain along with a leucine-rich repeat (LRR), and some also bear a toll interleukin 1 receptor (TIR) domain. In this study, we characterized a gene encoding a TIR-NB-ARC-LRR R protein (VpTNL1) (GenBank accession number KX649890) from wild Chinese grapevine Vitis pseudoreticulata accession "Baihe-35-1", which was identified previously from a transcriptomic analysis of leaves inoculated with powdery mildew (PM; Erysiphe necator (Schw.)). The VpTNL1 transcript was found to be highly induced in V. pseudoreticulata following inoculation with E. necator, as well as treatment with salicylic acid (SA). Sequence analysis demonstrated that the deduced amino acid sequence contained a TIR domain at the N-terminus, along with an NB-ARC and four LRRs domains within the C-terminus. Constitutive expression of VpTNL1 in Arabidopsis thaliana resulted in either a wild-type or dwarf phenotype. Intriguingly, the phenotypically normal transgenic lines displayed enhanced resistance to Arabidopsis PM, Golovinomyces cichoracearum, as well as to the virulent bacterial pathogen Pseudomonas syringae pv. tomato DC3000. Similarly, constitutive expression of VpTNL1 in Nicotiana tabacum was found to confer enhanced resistance to tobacco PM, Erysiphe cichoacearum DC. Subsequent isolation of the VpTNL1 promoter and deletion analysis indicated that TC-rich repeats and TCA elements likely play an important role in its response to E. necator and SA treatment, respectively. Taken together, these results indicate that VpTNL1 contributes to PM resistance in grapevine and provide an interesting gene target for the future amelioration of grape via breeding and/or biotechnology. PMID: 28131063 [PubMed - as supplied by publisher]

Related Articles The Genetic Architecture of Coronary Artery Disease: Current Knowledge and Future Opportunities. Curr Atheroscler Rep. 2017 Feb;19(2):6 Authors: Hartiala J, Schwartzman WS, Gabbay J, Ghazalpour A, Bennett BJ, Allayee H Abstract PURPOSE OF REVIEW: We provide an overview of our current understanding of the genetic architecture of coronary artery disease (CAD) and discuss areas of research that provide excellent opportunities for further exploration. RECENT FINDINGS: Large-scale studies in human populations, coupled with rapid advances in genetic technologies over the last decade, have clearly established the association of common genetic variation with risk of CAD. However, the effect sizes of the susceptibility alleles are for the most part modest and collectively explain only a small fraction of the overall heritability. By comparison, evidence that rare variants make a substantial contribution to risk of CAD has been somewhat disappointing thus far, suggesting that other biological mechanisms have yet to be discovered. Emerging data suggests that novel pathways involved in the development of CAD can be identified through complementary and integrative systems genetics strategies in mice or humans. There is also convincing evidence that gut bacteria play a previously unrecognized role in the development of CAD, particularly through metabolism of certain dietary nutrients that lead to proatherogenic metabolites in the circulation. A major effort is now underway to functionally understand the newly discovered genetic and biological associations for CAD, which could lead to the development of potentially novel therapeutic strategies. Other important areas of investigation for understanding the pathophysiology of CAD, including epistatic interactions between genes or with either sex and environmental factors, have not been studied on a broad scope and represent additional opportunities for future studies. PMID: 28130654 [PubMed - in process]

Related Articles CYP27A1 loss dysregulates cholesterol homeostasis in prostate cancer. Cancer Res. 2017 Jan 27;: Authors: Alfaqih MA, Nelson ER, Liu W, Safi R, Jasper JS, Macias E, Geradts J, Dubois LG, Thompson W, Freeman MR, Chang CY, Chi JT, McDonnell DP, Freedland SJ Abstract In this study, we used a bioinformatic approach to identify genes whose expression is dysregulated in human prostate cancers. One of the most dramatically downregulated genes identified encodes CYP27A1, an enzyme involved in regulating cellular cholesterol homeostasis. Importantly, lower CYP27A1 transcript levels were associated with shorter disease-free survival and higher tumor grade. Loss of CYP27A1 in prostate cancer was confirmed at the protein level by immunostaining for CYP27A1 in annotated tissue microarrays. Restoration of CYP27A1 expression in cells where its gene was silenced attenuated their growth in vitro and in tumor xenografts. Studies performed in vitro revealed that treatment of prostate cancer cells with 27-hydroxycholesterol (27HC), an enzymatic product of CYP27A1, reduced cellular cholesterol content in prostate cancer cell lines by inhibiting the activation of sterol regulatory-element binding protein 2 (SREBP2) and downregulating low-density lipoprotein receptor (LDLR) expression. Our findings suggest that CYP27A1 is a critical cellular cholesterol sensor in prostate cells and that dysregulation of the CYP27A1/27HC axis contributes significantly to prostate cancer pathogenesis. PMID: 28130224 [PubMed - as supplied by publisher]

Related Articles Farnesoid X Receptor Activation Promotes Hepatic Amino Acid Catabolism and Ammonium Clearance in Mice. Gastroenterology. 2017 Jan 24;: Authors: Massafra V, Milona A, Vos HR, Ramos RJ, Gerrits J, Willemsen EC, Ramos Pittol JM, Ijssennagger N, Houweling M, Prinsen HC, Verhoeven-Duif NM, Burgering BM, van Mil SW Abstract BACKGROUND & AIMS: The nuclear receptor subfamily 1 group H member 4 (NR1H4 or farnesoid X receptor, FXR) regulates bile acid synthesis, transport, and catabolism. FXR also regulates post-prandial lipid and glucose metabolism. We performed quantitative proteomic analyses of liver tissues from mice to evaluate these functions and investigate whether FXR regulates amino acid metabolism. METHODS: To study the role of FXR in mouse liver, we used mice with a disruption of Nr1h4 (FXR-knockout mice) and compared them to floxed control mice. Mice were gavaged with the FXR agonist obeticholic acid or vehicle for 11 days. Proteome analyses, as well as targeted metabolomics and chromatin immunoprecipitation, were performed on the livers of these mice. Primary rat hepatocytes were used to validate the role of FXR in amino acid catabolism by gene expression and metabolomics studies. Finally, control mice and mice with liver-specific disruption of Nr1h4 (liverFXR-knockout mice) were refed with a high-protein diet after 6 hours fasting and gavaged a (15)NH4Cl tracer. Gene expression and the metabolome were studied respectively in the livers and plasma from these mice. RESULTS: In livers of control mice and primary rat hepatocytes, activation of FXR with obeticholic acid increased expression of proteins that regulate amino acid degradation, ureagenesis, and glutamine synthesis. We found FXR to bind to regulatory sites of genes encoding these proteins in control livers. Liver tissues from FXR-knockout mice had reduced expression of urea cycle proteins, and accumulated precursors of ureagenesis, compared to control mice. In liverFXR-knockout mice on a high-protein diet, the plasma concentration of newly formed urea was significantly decreased compared with controls. In addition, liverFXR-knockout mice had reduced hepatic expression of enzymes that regulate ammonium detoxification, compared with controls. In contrast, obeticholic acid increased expression of genes encoding enzymes involved in ureagenesis compared to vehicle in C57Bl/6 mice. CONCLUSIONS: In livers of mice, FXR regulates amino acid catabolism and detoxification of ammonium via ureagenesis and glutamine synthesis. Failure of the urea cycle and hyperammonemia are common in patients with acute and chronic liver diseases; compounds that activate FXR might promote ammonium clearance in these patients. PMID: 28130067 [PubMed - as supplied by publisher]

Related Articles Identification of new biosignatures for clinical outcomes in stable coronary artery disease - The study protocol and initial observations of a prospective follow-up study in Taiwan. BMC Cardiovasc Disord. 2017 Jan 28;17(1):42 Authors: Leu HB, Yin WH, Tseng WK, Wu YW, Lin TH, Yeh HI, Chang KC, Wang JH, Wu CC, Chen JW Abstract BACKGROUND: Either classic or novel biomarkers have not been well investigated for clinical outcomes of coronary artery disease (CAD) in Asian people especially ethnic Chinese. We reported here a prospective national-based follow-up study that aims to elucidate the clinical profiles and to identify the new biosignatures (especially the non-lipid profile and inflammatory biomakers) for future clinical outcomes in a sizable cohort of stable CAD patients in Taiwan. METHODS: A total of 2500 CAD patients under stable condition after successful percutaneous coronary intervention will be enrolled for clinical data collection and blood/urine sampling in northern, southern, western, or eastern part of Taiwan between 2012 and 2017. They will be regularly followed up at least annually for 5 years to assess all cause deaths, hard clinical events (including cardiovascular death, nonfatal myocardial infarction, nonfatal stroke), and total cardiovascular events (including hard events, unplanned revascularization procedures, unplanned hospitalization for refractory or unstable angina, and for other causes such as stroke, transient ischemic attack, heart failure, or peripheral arterial occlusive disease). The classic and newly defined biosignatures will be compared in patients with and without clinical events during follow-up. The novel biomarkers will be identified via metabolomics analyses. Additionally, psychological personality and lifestyle data will be incorporated to explore the new dimensional views of the complex mechanisms of the disease. Till December 2014, the initial 1663 patients have been successfully enrolled. Among them, 85.93% are male; 36.22% have type 2 diabetes; 64.82% have hypertension; 56.04% are smokers and 20.44% have a family history of CAD. Their lipid profiles are under contemporary medical control with a mean plasma total cholesterol level of 163.51 ± 36.99 mg/dL and a mean low-density lipoprotein cholesterol level of 95.21 ± 29.98 mg/dL. DISCUSSION: This nationwide study has successfully started to update the contemporary information and to investigate the potential predictors for clinical outcomes of stable CAD patients in Taiwan. The identification of new biomarkers, lifestyle and psychological personality may help to elucidate the complex mechanisms and provide the novel rational to the individual treatment strategies in Asian especially ethnic Chinese patients with CAD. PMID: 28129736 [PubMed - in process]

Metabolomics for informing adverse outcome pathways: Androgen receptor activation and the pharmaceutical spironolactone. Aquat Toxicol. 2017 Jan 16;184:103-115 Authors: Davis JM, Ekman DR, Skelton DM, LaLone CA, Ankley GT, Cavallin JE, Villeneuve DL, Collette TW Abstract One objective in developing adverse outcome pathways (AOPs) is to connect biological changes that are relevant to risk assessors (i.e., fecundity) to molecular and cellular-level alterations that might be detectable at earlier stages of a chemical exposure. Here, we examined biochemical responses of fathead minnows (Pimephales promelas) to inform an AOP relevant to spironolactone's activation of the androgen receptor, as well as explore other biological impacts possibly unrelated to this receptor. Liquid chromatography with high resolution mass spectrometry (LC-MS) was used to measure changes in endogenous polar metabolites in livers of male and female fish that were exposed to five water concentrations of spironolactone (0, 0.05, 0.5, 5, or 50μgL(-1)) for 21days. Metabolite profiles were affected at the two highest concentrations (5 and 50μgL(-1)), but not in the lower-level exposures, which agreed with earlier reported results of reduced female fecundity and plasma vitellogenin (VTG) levels. We then applied partial least squares regression to assess whether metabolite alterations covaried with changes in fecundity, VTG gene expression and protein concentrations, and plasma 17β-estradiol and testosterone concentrations. Metabolite profiles significantly covaried with all measured endpoints in females, but only with plasma testosterone in males. Fecundity reductions occurred in parallel with changes in metabolites important in osmoregulation (e.g., betaine), membrane transport (e.g., l-carnitine), and biosynthesis of carnitine (e.g., methionine) and VTG (e.g., glutamate). Based on a network analysis program (i.e., mummichog), spironolactone also affected amino acid, tryptophan, and fatty acid metabolism. Thus, by identifying possible key events related to changes in biochemical pathways, this approach built upon an established AOP describing spironolactone's androgenic properties and highlighted broader implications potentially unrelated to androgen receptor activation, which could form a basis for the development of an AOP network. PMID: 28129603 [PubMed - as supplied by publisher]

Differential regulation of sphingolipid metabolism in plasma, hippocampus and cerebral cortex of mice administered sphingolipid modulating agents. J Neurochem. 2017 Jan 27;: Authors: Giles C, Takechi R, Mellett NA, Meikle PJ, Dhaliwal S, Mamo JC Abstract Accumulation of ceramide is implicated in mediating the cellular responses to stress and aberrant sphingolipid metabolism is frequently associated with metabolic and neurodegenerative diseases. It is often assumed that (1) peripheral disturbances in sphingolipid concentrations are reflective of processes occurring in the brain, or (2) circulating sphingolipids directly influence cerebral sphingolipid abundance. In order to address these assumptions, this study explores, in a physiological system, the metabolic pathways regulating sphingolipid metabolism in the brain and plasma of mice. Male C57Bl/6 were maintained on a low fat (CTRL) or saturated fat enriched (SFA) diet with, or without the provision of sphingolipid modulating agents. Following six months of feeding, the abundance of seven sphingolipid classes was assessed by LC-ESI-MS/MS in the hippocampus (HPF), cerebral cortex (CTX) and plasma. Long-term consumption of the SFA diet increased ceramide and dihydroceramide in the plasma. Inhibiting de novo synthesis ameliorated this effect, while inhibition of acidic sphingomyelinase, or the sphingosine-1-phosphate receptor agonist did not. SFA feeding did not influence sphingolipid levels in either the HPF or CTX. De novo synthesis inhibition reduced ceramide in the CTX, whilst treatment with a sphingosine-1-phosphate receptor agonist reduced ceramides in the HPF. Analysis of the individual ceramide species revealed the effects were chain-length dependent. Both positive and negative correlations were observed between plasma and HPF/CTX ceramide species. The findings in this study show that HPF and CTX sphingolipid concentration are influenced by distinct pathways, independent of peripheral sphingolipid concentration. This article is protected by copyright. All rights reserved. PMID: 28129448 [PubMed - as supplied by publisher]