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

PubMed

Approaches in studying the pharmacology of Chinese Medicine formulas: bottom-up, top-down-and meeting in the middle.

Thu, 29/03/2018 - 14:35
Related Articles Approaches in studying the pharmacology of Chinese Medicine formulas: bottom-up, top-down-and meeting in the middle. Chin Med. 2018;13:15 Authors: Huang T, Zhong LLD, Lin CY, Zhao L, Ning ZW, Hu DD, Zhang M, Tian K, Cheng CW, Bian ZX, for MZRW Research Group Abstract Investigating the pharmacology is key to the modernization of Chinese Medicine (CM) formulas. However, identifying which are the active compound(s) of CM formulas, which biological entities they target, and through which signaling pathway(s) they act to modify disease symptoms, are still difficult tasks for researchers, even when equipped with an arsenal of advanced modern technologies. Multiple approaches, including network pharmacology, pharmaco-genomics, -proteomics, and -metabolomics, have been developed to study the pharmacology of CM formulas. They fall into two general categories in terms of how they tackle a problem: bottom-up and top-down. In this article, we compared these two different approaches in several dimensions by using the case of MaZiRenWan (MZRW, also known as Hemp Seed Pill), a CM herbal formula for functional constipation. Multiple hypotheses are easy to be proposed in the bottom-up approach (e.g. network pharmacology); but these hypotheses are usually false positives and hard to be tested. In contrast, it is hard to suggest hypotheses in the top-down approach (e.g. pharmacometabolomics); however, once a hypothesis is proposed, it is much easier to be tested. Merging of these two approaches could results in a powerful approach, which could be the new paradigm for the pharmacological study of CM formulas. PMID: 29588653 [PubMed]

Metabolomics and biomarker discovery in Traumatic Brain Injury.

Thu, 29/03/2018 - 14:35
Related Articles Metabolomics and biomarker discovery in Traumatic Brain Injury. J Neurotrauma. 2018 Mar 27;: Authors: Banoei MM, Casault C, Metwaly SM, Winston BW Abstract Traumatic brain injury (TBI) is one of the leading cause of disability and mortality worldwide. The TBI pathogenesis can induce broad pathophysiological consequences and clinical outcomes due to the brain complexity. Thus, the diagnosis and prognosis of outcome are important issues for the management of mild, moderate and severe forms of TBI. Metabolomics of readily accessible biofluids is a promising tool for establishing more useful and reliable biomarkers of TBI than using clinical findings alone. Metabolites are an integral part of all biochemical and pathophysiological pathways. Metabolomic processes respond to the internal and external stimuli resulting in an alteration of metabolite concentrations. Current high throughput and highly sensitive analytical tools are capable of detecting and quantifying the small concentrations of metabolites allowing us to measure metabolite alterations following a pathological event when compared to a normal state or a different pathological process. Further, these metabolites biomarkers could be used for the assessment of injury severity as well as discovering of mechanisms of injury and defining structural damage in brain in TBI. Metabolite biomarkers can also be used for the prediction of outcome, monitoring treatment response, in the assessment of or prognosis of post-injury recovery and potentially in the use of neuroplasticity procedures. Metabolomics can also enhance our understanding of the pathophysiological mechanisms of TBI, both in primary and secondary injury. Thus, this review presents the promising application of metabolomics for the assessment of TBI as a stand alone platform or in association with proteomics in the clinical setting. PMID: 29587568 [PubMed - as supplied by publisher]

Bile Acids as Potential Biomarkers to Assess Liver Impairment in Polycystic Kidney Disease.

Thu, 29/03/2018 - 14:35
Related Articles Bile Acids as Potential Biomarkers to Assess Liver Impairment in Polycystic Kidney Disease. Int J Toxicol. 2018 Mar/Apr;37(2):144-154 Authors: Brock WJ, Beaudoin JJ, Slizgi JR, Su M, Jia W, Roth SE, Brouwer KLR Abstract Polycystic kidney disease is characterized by the progressive development of kidney cysts and declining renal function with frequent development of cysts in other organs including the liver. The polycystic kidney (PCK) rat is a rodent model of polycystic liver disease that has been used to study hepatorenal disease progression and evaluate pharmacotherapeutic interventions. Biomarkers that describe the cyst progression, liver impairment, and/or hepatic cyst burden could provide clinical utility for this disease. In the present study, hepatic cyst volume was measured by magnetic resonance imaging in PCK rats at 12, 16, and 20 weeks. After 20 weeks, Sprague Dawley (n = 4) and PCK (n = 4) rats were sacrificed and 42 bile acids were analyzed in the liver, bile, serum, and urine by liquid chromatography coupled to tandem mass spectrometry. Bile acid profiling revealed significant increases in total bile acids (molar sum of all measured bile acids) in the liver (13-fold), serum (6-fold), and urine (3-fold) in PCK rats, including those speciated bile acids usually associated with hepatotoxicity. Total serum bile acids correlated with markers of liver impairment (liver weight, total liver bile acids, total hepatotoxic liver bile acids, and cyst volume [ r > 0.75; P < 0.05]). Based on these data, serum bile acids may be useful biomarkers of liver impairment in polycystic hepatorenal disease. PMID: 29587557 [PubMed - in process]

Surface fitting for calculating the second dimension retention index in comprehensive two-dimensional gas chromatography mass spectrometry.

Thu, 29/03/2018 - 14:35
Related Articles Surface fitting for calculating the second dimension retention index in comprehensive two-dimensional gas chromatography mass spectrometry. J Chromatogr A. 2018 Mar 02;1539:62-70 Authors: Prodhan MAI, Yin X, Kim S, McClain C, Zhang X Abstract Comprehensive two-dimensional gas chromatography mass spectrometry (GC × GC-MS) has been widely used for analysis of volatile compounds. However, the second dimension retention index (I) of each compound is not widely used to aid compound identification owing to the limited accuracy of I calculation. We report a surface fitting approach to the calculation of I using n-alkanes (C7-C30) as references, where the second dimension retention time (2tR) and the second dimension column temperature (2Te) formed the X-Y plane and the I was the Z-axis to form the I surface. Compared to the conventional approach for calculating I using isovolatility curves, the surface fitting approach eliminated the construction of isovolatility curves for the reference compounds and gives better reproducibility. The goodness of the proposed surface fitting achieved R2 = 0.9999 and RMSE = 6.1 retention index units (iu). Ten-fold cross validation demonstrated the surface fitting approach had a good predictability with average R2 = 0.9999 and RMSE = 6.6 iu. The developed method was also applied to calculate the second dimension retention indices of compound standards in two commercial mixtures MegaMix A and MegaMix B. The mean standard deviation of the calculated I was only 1.6 iu for compounds in MegaMix A and 3.4 iu for compounds in MegaMix B. Compared with the literature results, the small value of standard deviation in the calculated retention index using surface fitting method shows that the surface fitting method has less measurement variability than the conventional isovolatility curve approach. PMID: 29395161 [PubMed - indexed for MEDLINE]

metabolomics; +19 new citations

Wed, 28/03/2018 - 14:12
19 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 2018/03/28PubMed comprises more than millions of citations for biomedical literature from MEDLINE, life science journals, and online books. Citations may include links to full-text content from PubMed Central and publisher web sites.

metabolomics; +34 new citations

Tue, 27/03/2018 - 22:53
34 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 2018/03/27PubMed comprises more than millions of citations for biomedical literature from MEDLINE, life science journals, and online books. Citations may include links to full-text content from PubMed Central and publisher web sites.

metabolomics; +34 new citations

Tue, 27/03/2018 - 19:52
34 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 2018/03/27PubMed comprises more than millions of citations for biomedical literature from MEDLINE, life science journals, and online books. Citations may include links to full-text content from PubMed Central and publisher web sites.

Metabolomic analysis of short-term sulfamethazine exposure on marine medaka (Oryzias melastigma) by comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry.

Mon, 26/03/2018 - 00:40
Metabolomic analysis of short-term sulfamethazine exposure on marine medaka (Oryzias melastigma) by comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry. Aquat Toxicol. 2018 Mar 08;198:269-275 Authors: Liu Y, Wang X, Li Y, Chen X Abstract Toxicological effects of sulfamethazine (SM2) have garnered increasing concern due to its wide applications in aquaculture and persistence in the aquatic environment. Most studies have main focused on freshwater fish (i.e. zebrafish), while information regarding effects of SM2 on marine species is still scarce. Here, the hepatotoxicities in marine medaka (Oryzias melastigma) with an increasing SM2 concentration exposures (0.01 mg/L, 0.1 mg/L and 1 mg/L) were assessed by comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry (GC × GC-TOF/MS) based metabolomics. Significant metabolites belonging to different metabolites classes were identified by multivariate statistical analysis. The increases levels of amino acids including alanine, asparagine, ornithine, proline, threonine, glutamic acid, lysine, tyrosine and phenylalanine were found in at least two exposure levels. Pathway analysis revealed that amino acids played important biological roles during SM2 exposure: up-regulation of high energy-related amino acids for energy alteration; immune function disorder, oxidative stress and corresponding toxicities defenses. The down regulations of sugar and fatty acid metabolism were observed with an increasing level of SM2 exposure, suggesting that extra energy for cellular defense and detoxification was demanded in terms of different stress request. This study provided an innovative perspective to explore possible SM2 induced hepatic damages at three exposure levels on a nontarget aquatic specie. PMID: 29573603 [PubMed - as supplied by publisher]

Metabolic perturbations in Welsh Ponies with insulin dysregulation, obesity, and laminitis.

Mon, 26/03/2018 - 00:40
Metabolic perturbations in Welsh Ponies with insulin dysregulation, obesity, and laminitis. J Vet Intern Med. 2018 Mar 23;: Authors: Jacob SI, Murray KJ, Rendahl AK, Geor RJ, Schultz NE, McCue ME Abstract BACKGROUND: Metabolomics, the study of small-molecule metabolites, has increased understanding of human metabolic diseases, but has not been used to study equine metabolic syndrome (EMS). OBJECTIVES: (1) To examine the serum metabolome of Welsh Ponies with and without insulin dysregulation before and during an oral sugar test (OST). (2) To identify differences in metabolites in ponies with insulin dysregulation, obesity, or history of laminitis. ANIMALS: Twenty Welsh Ponies (mean ± SD; 13.8 ± 9.0 years) classified as non-insulin dysregulated [CON] (n = 10, insulin < 30 mU/L) or insulin dysregulated [ID] (n = 10, insulin > 60 mU/L) at 75 minutes after administration of Karo syrup, obese (n = 6) or nonobese (n = 14), and history of laminitis (n = 9) or no history of laminitis (n = 11). METHODS: Case-control study. Metabolomic analysis was performed on serum obtained at 0 minutes (baseline) and 75 minutes during the OST. Data were analyzed with multivariable mixed linear models with significance set at P ≤ .05. RESULTS: Metabolomic analysis of 646 metabolites (506 known) detected significant metabolite differences. At baseline, 55 metabolites (insulin response), 91 metabolites (obesity status), and 136 metabolites (laminitis history) were different. At 75 minutes, 51 metabolites (insulin response), 102 metabolites (obesity status), and 124 metabolites (laminitis history) were different. CONCLUSIONS AND CLINICAL IMPORTANCE: Use of metabolomics could have diagnostic utility for early detection of EMS and provide new knowledge regarding the pathophysiology of metabolic perturbations associated with this condition that might lead to improved clinical management. PMID: 29572947 [PubMed - as supplied by publisher]

Omics-approaches for food authentication.

Mon, 26/03/2018 - 00:40
Omics-approaches for food authentication. Electrophoresis. 2018 Mar 23;: Authors: Creydt M, Fischer M Abstract The development of analytical strategies to fight against food fraud is currently one of the most developing fields in food science, as the food value chain becomes increasingly complex and global. Food can be certified by clear labeling, but also by objective analytical methods. As shown the last years, especially the omics technologies such as genomics, proteomics, metabolomics and isotopolomics are suitable to prove the geographical origin, the production or cultivation process, and the biological and the overall chemical identity of food. This article describes different analytical approaches beginning with non-targeted strategies as well as the further developmental stages of transferring the methods to routine laboratories. This article is protected by copyright. All rights reserved. PMID: 29572870 [PubMed - as supplied by publisher]

Untargeted metabolomics reveals a new mode of action of pretomanid (PA-824).

Mon, 26/03/2018 - 00:40
Untargeted metabolomics reveals a new mode of action of pretomanid (PA-824). Sci Rep. 2018 Mar 23;8(1):5084 Authors: Baptista R, Fazakerley DM, Beckmann M, Baillie L, Mur LAJ Abstract Pretomanid is a promising anti-tubercular drug currently at clinical phase III, but its mechanisms of action are currently unclear. This study aimed to: (i) reveal the metabolome of Mycobacterium smegmatis under pretomanid treatment; (ii) compare major sources of metabolite variation in bacteria treated with pretomanid treatment and other antibiotics; and (iii) to target metabolites responsible for the killing activity of pretomanid in mycobacteria. Untargeted high-resolution metabolite profiling was carried out using flow infusion electrospray ion high resolution mass spectrometry (FIE-HRMS) to identify and quantify metabolites. The identification of key metabolites was independently confirmed by gas-chromatography time-of flight mass spectrometry (GC-tofMS) in comparison to standards. Pretomanid treatments generated a unique distinctive metabolite profile when compared to ampicillin, ethambutol, ethionamide, isoniazid, kanamycin, linezolid, rifampicin and streptomycin. Metabolites which differed significantly only with pretomanid treatment were identified and mapped on to bacterial metabolic pathways. This targeted the pentose phosphate pathway with significant accumulation seen with fructose-6-phosphate, ribose-5-phosphate and glyceraldehyde-3-phosphate. These effects were linked to the accumulation of a toxic metabolite methylglyoxal. This compound showed significant antimicrobial activity (MIC 0.65 mM) against M. smegmatis. PMID: 29572459 [PubMed - in process]

The cross-tissue metabolic response of abalone (Haliotis midae) to functional hypoxia.

Mon, 26/03/2018 - 00:40
The cross-tissue metabolic response of abalone (Haliotis midae) to functional hypoxia. Biol Open. 2018 Mar 23;7(3): Authors: Venter L, Loots DT, Mienie LJ, Jansen van Rensburg PJ, Mason S, Vosloo A, Lindeque JZ Abstract Functional hypoxia is a stress condition caused by the abalone itself as a result of increased muscle activity, which generally necessitates the employment of anaerobic metabolism if the activity is sustained for prolonged periods. With that being said, abalone are highly reliant on anaerobic metabolism to provide partial compensation for energy production during oxygen-deprived episodes. However, current knowledge on the holistic metabolic response for energy metabolism during functional hypoxia, and the contribution of different metabolic pathways and various abalone tissues towards the overall accumulation of anaerobic end-products in abalone are scarce. Metabolomics analysis of adductor muscle, foot muscle, left gill, right gill, haemolymph and epipodial tissue samples indicated that South African abalone (Haliotis midae) subjected to functional hypoxia utilises predominantly anaerobic metabolism, and depends on all of the main metabolite classes (proteins, carbohydrates and lipids) for energy supply. Functional hypoxia caused increased levels of anaerobic end-products: lactate, alanopine, tauropine, succinate and alanine. Also, elevation in arginine levels was detected, confirming that abalone use phosphoarginine to generate energy during functional hypoxia. Different tissues showed varied metabolic responses to hypoxia, with functional hypoxia showing excessive changes in the adductor muscle and gills. From this metabolomics investigation, it becomes evident that abalone are metabolically able to produce sufficient amounts of energy when functional hypoxia is experienced. Also, tissue interplay enables the adjustment of H. midae energy requirements as their metabolism shifts from aerobic to anaerobic respiration during functional hypoxia.This article has an associated First Person interview with the first author of the paper. PMID: 29572259 [PubMed]

Circulating Branched-Chain Amino Acids and Incident Cardiovascular Disease in a Prospective Cohort of US Women.

Mon, 26/03/2018 - 00:40
Circulating Branched-Chain Amino Acids and Incident Cardiovascular Disease in a Prospective Cohort of US Women. Circ Genom Precis Med. 2018 Apr;11(4):e002157 Authors: Tobias DK, Lawler PR, Harada PH, Demler OV, Ridker PM, Manson JE, Cheng S, Mora S Abstract BACKGROUND: Circulating branched-chain amino acids (BCAAs; isoleucine, leucine, and valine) are strong predictors of type 2 diabetes mellitus (T2D), but their association with cardiovascular disease (CVD) is uncertain. We hypothesized that plasma BCAAs are positively associated with CVD risk and evaluated whether this was dependent on an intermediate diagnosis of T2D. METHODS: Participants in the Women's Health Study prospective cohort were eligible if free of CVD at baseline blood collection (n=27 041). Plasma metabolites were measured via nuclear magnetic resonance spectroscopy. Multivariable Cox regression models estimated hazard ratios (HRs) and 95% confidence intervals (CIs) for BCAAs with incident CVD (myocardial infarction, stroke, and coronary revascularization). RESULTS: We confirmed 2207 CVD events over a mean 18.6 years of follow-up. Adjusting for age, body mass index, and other established CVD risk factors, total BCAAs were positively associated with CVD (per SD: HR, 1.13; 95% CI, 1.08-1.18), comparable to LDL-C (low-density lipoprotein cholesterol) with CVD (per SD: HR, 1.12; 95% CI, 1.07-1.17). BCAAs were associated with coronary events (myocardial infarction: HR, 1.16; 95% CI, 1.06-1.26; revascularization: HR, 1.17; 95% CI, 1.11-1.25), and borderline significant association with stroke (HR, 1.07; 95% CI, 0.99-1.15). The BCAA-CVD association was greater (P interaction=0.036) among women who developed T2D before CVD (HR, 1.20; 95% CI, 1.08-1.32) versus women without T2D (HR, 1.08; 95% CI, 1.03-1.14). Adjusting for LDL-C, an established CVD risk factor, did not attenuate these findings; however, adjusting for HbA1c and insulin resistance eliminated the associations of BCAAs with CVD. CONCLUSIONS: Circulating plasma BCAAs were positively associated with incident CVD in women. Impaired BCAA metabolism may capture the long-term risk of the common cause underlying T2D and CVD. PMID: 29572205 [PubMed - in process]

metabolomics; +17 new citations

Sat, 24/03/2018 - 14:06
17 new pubmed citations were retrieved for your search. Click on the search hyperlink below to display the complete search results: metabolomics These pubmed results were generated on 2018/03/24PubMed comprises more than millions of citations for biomedical literature from MEDLINE, life science journals, and online books. Citations may include links to full-text content from PubMed Central and publisher web sites.

Non-Uniform and Absolute Minimal Sampling for High-Throughput Multidimensional NMR Applications.

Fri, 23/03/2018 - 20:03
Non-Uniform and Absolute Minimal Sampling for High-Throughput Multidimensional NMR Applications. Chemistry. 2018 Mar 22;: Authors: Li D, Hansen A, Bruschweiler-Li L, Bruschweiler R Abstract Many biomolecular NMR applications can benefit from the faster acquisition of multidimensional NMR data with high resolution and their automated analysis and interpretation. In recent years, a number of non-uniform sampling (NUS) approaches have been introduced for the reconstruction of multidimensional NMR spectra, such as compressed sensing, thereby bypassing traditional Fourier-transform processing. Such approaches are applicable to both biomacromolecules and small molecules and their complex mixtures and can be combined with homonuclear decoupling (pure shift) and covariance processing. For homonuclear 2D TOCSY experiments, absolute minimal sampling (AMS) permits the drastic shortening of measurement times necessary for high-throughput applications for identification and quantification of components in complex biological mixtures in the field of metabolomics. Such TOCSY spectra can be comprehensively represented by graph theoretical maximal cliques for the identification of entire spin systems and their subsequent query against NMR databases. Integration of these methods in webservers permits the rapid and reliable identification of mixture components. Recent progress is reviewed in this Minireview. PMID: 29566285 [PubMed - as supplied by publisher]

A Metabolomics Approach Uncovers Differences between Traditional and Commercial Dairy Products in Buryatia (Russian Federation).

Fri, 23/03/2018 - 20:03
A Metabolomics Approach Uncovers Differences between Traditional and Commercial Dairy Products in Buryatia (Russian Federation). Molecules. 2018 Mar 22;23(4): Authors: Pan L, Yu J, Mi Z, Mo L, Jin H, Yao C, Ren D, Menghe B Abstract Commercially available and traditional dairy products differ in terms of their manufacturing processes. In this study, commercially available and traditionally fermented cheese, yogurt, and milk beverages were analyzed and compared. The metabolomic technique of ultra-performance liquid chromatography-quadrupole-time of flight mass spectrometry (UPLC-Q-TOF) in the MSE mode was used in combination with statistical methods, including univariate analysis and chemometric analysis, to determine the differences in metabolite profiles between commercially and traditionally fermented dairy products. The experimental results were analyzed statistically and showed that traditional and commercial dairy products were well differentiated in both positive and negative ion modes, with significant differences observed between the samples. After screening for metabolite differences, we detected differences between traditional milk beverages and yogurt and their commercial counterparts in terms of the levels of compounds such as l-lysine, l-methionine, l-citrulline, l-proline, l-serine, l-valine and l-homocysteine, and of short peptides such as Asp-Arg, Gly-Arg, His-Pro, Pro-Asn. The greatest difference between commercially available and traditional cheese was in the short peptide composition, as commercially available and traditional cheese is rich in short peptides. PMID: 29565828 [PubMed - in process]

Alterations in Docosahexaenoic Acid-Related Lipid Cascades in Inflammatory Bowel Disease Model Mice.

Fri, 23/03/2018 - 20:03
Alterations in Docosahexaenoic Acid-Related Lipid Cascades in Inflammatory Bowel Disease Model Mice. Dig Dis Sci. 2018 Mar 21;: Authors: Nishiumi S, Izumi Y, Yoshida M Abstract BACKGROUND: Inflammatory bowel disease (IBD) is an intestinal disorder, involving chronic and relapsing inflammation of the digestive tract. Dysregulation of the immune system based on genetic, environmental, and other factors seems to be involved in the onset of IBD, but its exact pathogenesis remains unclear. Therefore, radical treatments for ulcerative colitis and Crohn's disease remain to be found, and IBD is considered to be a refractory disease. AIMS: The aim of this study is to obtain novel insights into IBD via metabolite profiling of interleukin (IL)-10 knockout mice (an IBD animal model that exhibits a dysregulated immune system). METHODS: In this study, the metabolites in the large intestine and plasma of IL-10 knockout mice were analyzed. In our analytical system, two kinds of analysis (gas chromatography/mass spectrometry and liquid chromatography/mass spectrometry) were used to detect a broader range of metabolites, including both hydrophilic and hydrophobic metabolites. In addition, an analysis of lipid mediators in the large intestine and ascites of IL-10 knockout mice was carried out. RESULTS: The levels of a variety of metabolites, including lipid mediators, were altered in IL-10 knockout mice. For example, high large intestinal and plasma levels of docosahexaenoic acid (DHA) were observed. In addition, arachidonic acid- and DHA-related lipid cascades were upregulated in the ascites of the IL-10 knockout mice. CONCLUSIONS: Our findings based on metabolite profiles including lipid mediators must contribute to development of researches about IBD. PMID: 29564669 [PubMed - as supplied by publisher]

CoIN: co-inducible nitrate expression system for secondary metabolites in Aspergillus nidulans.

Fri, 23/03/2018 - 20:03
CoIN: co-inducible nitrate expression system for secondary metabolites in Aspergillus nidulans. Fungal Biol Biotechnol. 2018;5:6 Authors: Wiemann P, Soukup AA, Folz JS, Wang PM, Noack A, Keller NP Abstract Background: Sequencing of fungal species has demonstrated the existence of thousands of putative secondary metabolite gene clusters, the majority of them harboring a unique set of genes thought to participate in production of distinct small molecules. Despite the ready identification of key enzymes and potential cluster genes by bioinformatics techniques in sequenced genomes, the expression and identification of fungal secondary metabolites in the native host is often hampered as the genes might not be expressed under laboratory conditions and the species might not be amenable to genetic manipulation. To overcome these restrictions, we developed an inducible expression system in the genetic model Aspergillus nidulans. Results: We genetically engineered a strain of A. nidulans devoid of producing eight of the most abundant endogenous secondary metabolites to express the sterigmatocystin Zn(II)2Cys6 transcription factor-encoding gene aflR and its cofactor aflS under control of the nitrate inducible niiA/niaD promoter. Furthermore, we identified a subset of promoters from the sterigmatocystin gene cluster that are under nitrate-inducible AflR/S control in our production strain in order to yield coordinated expression without the risks from reusing a single inducible promoter. As proof of concept, we used this system to produce β-carotene from the carotenoid gene cluster of Fusarium fujikuroi. Conclusion: Utilizing one-step yeast recombinational cloning, we developed an inducible expression system in the genetic model A. nidulans and show that it can be successfully used to produce commercially valuable metabolites. PMID: 29564145 [PubMed]

Untargeted metabolomics identifies trimethyllysine, a TMAO-producing nutrient precursor, as a predictor of incident cardiovascular disease risk.

Fri, 23/03/2018 - 20:03
Untargeted metabolomics identifies trimethyllysine, a TMAO-producing nutrient precursor, as a predictor of incident cardiovascular disease risk. JCI Insight. 2018 Mar 22;3(6): Authors: Li XS, Wang Z, Cajka T, Buffa JA, Nemet I, Hurd AG, Gu X, Skye SM, Roberts AB, Wu Y, Li L, Shahen CJ, Wagner MA, Hartiala JA, Kerby RL, Romano KA, Han Y, Obeid S, Lüscher TF, Allayee H, Rey FE, DiDonato JA, Fiehn O, Tang WHW, Hazen SL Abstract Using an untargeted metabolomics approach in initial (N = 99 subjects) and replication cohorts (N = 1,162), we discovered and structurally identified a plasma metabolite associated with cardiovascular disease (CVD) risks, N6,N6,N6-trimethyl-L-lysine (trimethyllysine, TML). Stable-isotope-dilution tandem mass spectrometry analyses of an independent validation cohort (N = 2,140) confirmed TML levels are independently associated with incident (3-year) major adverse cardiovascular event risks (hazards ratio [HR], 2.4; 95% CI, 1.7-3.4) and incident (5-year) mortality risk (HR, 2.9; 95% CI, 2.0-4.2). Genome-wide association studies identified several suggestive loci for TML levels, but none reached genome-wide significance; and d9(trimethyl)-TML isotope tracer studies confirmed TML can serve as a nutrient precursor for gut microbiota-dependent generation of trimethylamine (TMA) and the atherogenic metabolite trimethylamine N-oxide (TMAO). Although TML was shown to be abundant in both plant- and animal-derived foods, mouse and human fecal cultures (omnivores and vegans) showed slow conversion of TML to TMA. Furthermore, unlike chronic dietary choline, TML supplementation in mice failed to elevate plasma TMAO or heighten thrombosis potential in vivo. Thus, TML is identified as a strong predictor of incident CVD risks in subjects and to serve as a dietary precursor for gut microbiota-dependent generation of TMAO; however, TML does not appear to be a major microbial source for TMAO generation in vivo. PMID: 29563342 [PubMed - as supplied by publisher]

GC-MS-Based Endometabolome Analysis Differentiates Prostate Cancer from Normal Prostate Cells.

Fri, 23/03/2018 - 20:03
GC-MS-Based Endometabolome Analysis Differentiates Prostate Cancer from Normal Prostate Cells. Metabolites. 2018 Mar 19;8(1): Authors: Lima AR, Araújo AM, Pinto J, Jerónimo C, Henrique R, Bastos ML, Carvalho M, Guedes de Pinho P Abstract Prostate cancer (PCa) is an important health problem worldwide. Diagnosis and management of PCa is very complex because the detection of serum prostate specific antigen (PSA) has several drawbacks. Metabolomics brings promise for cancer biomarker discovery and for better understanding PCa biochemistry. In this study, a gas chromatography-mass spectrometry (GC-MS) based metabolomic profiling of PCa cell lines was performed. The cell lines include 22RV1 and LNCaP from PCa with androgen receptor (AR) expression, DU145 and PC3 (which lack AR expression), and one normal prostate cell line (PNT2). Regarding the metastatic potential, PC3 is from an adenocarcinoma grade IV with high metastatic potential, DU145 has a moderate metastatic potential, and LNCaP has a low metastatic potential. Using multivariate analysis, alterations in levels of several intracellular metabolites were detected, disclosing the capability of the endometabolome to discriminate all PCa cell lines from the normal prostate cell line. Discriminant metabolites included amino acids, fatty acids, steroids, and sugars. Six stood out for the separation of all the studied PCa cell lines from the normal prostate cell line: ethanolamine, lactic acid, β-Alanine, L-valine, L-leucine, and L-tyrosine. PMID: 29562689 [PubMed]

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