PubMed

Related Articles Prioritization of Candidate Genes in QTL Regions for Physiological and Biochemical Traits Underlying Drought Response in Barley (Hordeum vulgare L.). Front Plant Sci. 2018;9:769 Authors: Gudys K, Guzy-Wrobelska J, Janiak A, Dziurka MA, Ostrowska A, Hura K, Jurczyk B, Żmuda K, Grzybkowska D, Śróbka J, Urban W, Biesaga-Koscielniak J, Filek M, Koscielniak J, Mikołajczak K, Ogrodowicz P, Krystkowiak K, Kuczyńska A, Krajewski P, Szarejko I Abstract Drought is one of the most adverse abiotic factors limiting growth and productivity of crops. Among them is barley, ranked fourth cereal worldwide in terms of harvested acreage and production. Plants have evolved various mechanisms to cope with water deficit at different biological levels, but there is an enormous challenge to decipher genes responsible for particular complex phenotypic traits, in order to develop drought tolerant crops. This work presents a comprehensive approach for elucidation of molecular mechanisms of drought tolerance in barley at the seedling stage of development. The study includes mapping of QTLs for physiological and biochemical traits associated with drought tolerance on a high-density function map, projection of QTL confidence intervals on barley physical map, and the retrievement of positional candidate genes (CGs), followed by their prioritization based on Gene Ontology (GO) enrichment analysis. A total of 64 QTLs for 25 physiological and biochemical traits that describe plant water status, photosynthetic efficiency, osmoprotectant and hormone content, as well as antioxidant activity, were positioned on a consensus map, constructed using RIL populations developed from the crosses between European and Syrian genotypes. The map contained a total of 875 SNP, SSR and CGs, spanning 941.86 cM with resolution of 1.1 cM. For the first time, QTLs for ethylene, glucose, sucrose, maltose, raffinose, α-tocopherol, γ-tocotrienol content, and catalase activity, have been mapped in barley. Based on overlapping confidence intervals of QTLs, 11 hotspots were identified that enclosed more than 60% of mapped QTLs. Genetic and physical map integration allowed the identification of 1,101 positional CGs within the confidence intervals of drought response-specific QTLs. Prioritization resulted in the designation of 143 CGs, among them were genes encoding antioxidants, carboxylic acid biosynthesis enzymes, heat shock proteins, small auxin up-regulated RNAs, nitric oxide synthase, ATP sulfurylases, and proteins involved in regulation of flowering time. This global approach may be proposed for identification of new CGs that underlies QTLs responsible for complex traits. PMID: 29946328 [PubMed]

Related Articles Repeated Administration of D-Amphetamine Induces Distinct Alterations in Behavior and Metabolite Levels in 129Sv and Bl6 Mouse Strains. Front Neurosci. 2018;12:399 Authors: Vanaveski T, Narvik J, Innos J, Philips MA, Ottas A, Plaas M, Haring L, Zilmer M, Vasar E Abstract The main goal of the study was to characterize the behavioral and metabolomic profiles of repeated administration (for 11 days) of d-amphetamine (AMPH, 3 mg/kg i. p.), indirect agonist of dopamine (DA), in widely used 129S6/SvEvTac (129Sv) and C57BL/6NTac (Bl6) mouse strains. Acute administration of AMPH (acute AMPH) induced significantly stronger motor stimulation in Bl6. However, repeated administration of AMPH (repeated AMPH) caused stronger motor sensitization in 129Sv compared acute AMPH. Body weight of 129Sv was reduced after repeated saline and AMPH, whereas no change occurred in Bl6. In the metabolomic study, acute AMPH induced an elevation of isoleucine and leucine, branched chain amino acids (BCAA), whereas the level of hexoses was reduced in Bl6. Both BCAAs and hexoses remained on level of acute AMPH after repeated AMPH in Bl6. Three biogenic amines [asymmetric dimethylarginine (ADMA), alpha-aminoadipic acid (alpha-AAA), kynurenine] were significantly reduced after repeated AMPH. Acute AMPH caused in 129Sv a significant reduction of valine, lysophosphatidylcholines (lysoPC a C16:0, lysoPC a C18:2, lysoPC a C20:4), phosphatidylcholine (PC) diacyls (PC aa C34:2, PC aa C36:2, PC aa C36:3, PC aa C36:4) and alkyl-acyls (PC ae C38:4, PC ae C40:4). However, repeated AMPH increased the levels of valine and isoleucine, long-chain acylcarnitines (C14, C14:1-OH, C16, C18:1), PC diacyls (PC aa C38:4, PC aa C38:6, PC aa C42:6), PC acyl-alkyls (PC ae C38:4, PC ae C40:4, PC ae C40:5, PC ae C40:6, PC ae C42:1, PC ae C42:3) and sphingolipids [SM(OH)C22:1, SM C24:0] compared to acute AMPH in 129Sv. Hexoses and kynurenine were reduced after repeated AMPH compared to saline in 129Sv. The established changes probably reflect a shift in energy metabolism toward lipid molecules in 129Sv because of reduced level of hexoses. Pooled data from both strains showed that the elevation of isoleucine and leucine was a prominent biomarker of AMPH-induced behavioral sensitization. Simultaneously a significant decline of hexoses, citrulline, ADMA, and kynurenine occurred. The reduced levels of kynurenine, ADMA, and citrulline likely reflect altered function of N-methyl-D-aspartate (NMDA) and NO systems caused by repeated AMPH. Altogether, 129Sv strain displays stronger sensitization toward AMPH and larger variance in metabolite levels than Bl6. PMID: 29946233 [PubMed]

Related Articles Dietary Intakes and Circulating Concentrations of Branched-Chain Amino Acids in Relation to Incident Type 2 Diabetes Risk Among High-Risk Women with a History of Gestational Diabetes Mellitus. Clin Chem. 2018 Jun 26;: Authors: Tobias DK, Clish C, Mora S, Li J, Liang L, Hu FB, Manson JE, Zhang C Abstract BACKGROUND: Circulating branched-chain amino acids (BCAAs; isoleucine, leucine, valine) are consistently associated with increased type 2 diabetes (T2D) risk, but the relationship with dietary intake of BCAAs is less clear. METHODS: The longitudinal Nurses' Health Study II cohort conducted a blood collection from 1996 to 1999. We profiled plasma metabolites among 172 incident T2D cases and 175 age-matched controls from women reporting a history of gestational diabetes before blood draw. We estimated dietary energy-adjusted BCAAs from food frequency questionnaires. We used conditional logistic regression models to estimate odds ratios (OR) and 95% CI of T2D risk across quartiles (Q1-Q4) of BCAAs, adjusting for age, body mass index (BMI), physical activity, family history, and other established risk factors. We also assessed joint exposure to below/above medians of diet and plasma concentrations, with lower diet/lower plasma as reference. RESULTS: Dietary and plasma BCAA concentrations were positively associated with incident T2D (diet Q4 vs Q1 OR = 4.6, CI = 1.6, 13.4; plasma Q4 vs Q1 OR = 4.4, CI = 1.4, 13.4). Modeling the joint association indicated that higher diet BCAAs were associated with T2D when plasma concentrations were also higher (OR = 6.0, CI = 2.1, 17.2) but not when concentrations were lower (OR = 1.6, CI = 0.61, 4.1). Conversely, higher plasma BCAAs were associated with increased T2D for either lower or higher diet. CONCLUSIONS: Independent of BMI and other risk factors, higher diet and plasma BCAA concentrations were associated with an increased incident T2D risk among high-risk women with a history of gestational diabetes, supporting impaired BCAA metabolism as conferring T2D risk. PMID: 29945965 [PubMed - as supplied by publisher]

Related Articles Restricted immune activation and internalisation of anti-idiotype complexes between drug and antidrug antibodies. Ann Rheum Dis. 2018 Jun 26;: Authors: van Schie KA, Kruithof S, Ooijevaar-de Heer P, Derksen NIL, van de Bovenkamp FS, Saris A, Vidarsson G, Bentlage AEH, Jiskoot W, Romeijn S, Koning RI, Bos E, Stork EM, Koeleman CAM, Wuhrer M, Wolbink G, Rispens T Abstract OBJECTIVES: Therapeutic antibodies can provoke an antidrug antibody (ADA) response, which can form soluble immune complexes with the drug in potentially high amounts. Nevertheless, ADA-associated adverse events are usually rare, although with notable exceptions including infliximab. The immune activating effects and the eventual fate of these 'anti-idiotype' complexes are poorly studied, hampering assessment of ADA-associated risk of adverse events. We investigated the in vitro formation and biological activities of ADA-drug anti-idiotype immune complexes using patient-derived monoclonal anti-infliximab antibodies. METHODS: Size distribution and conformation of ADA-drug complexes were characterised by size-exclusion chromatography and electron microscopy. Internalisation of and immune activation by complexes of defined size was visualised with flow imaging, whole blood cell assay and C4b/c ELISA. RESULTS: Size and conformation of immune complexes depended on the concentrations and ratio of drug and ADA; large complexes (>6 IgGs) formed only with high ADA titres. Macrophages efficiently internalised tetrameric and bigger complexes in vitro, but not dimers. Corroborating these results, ex vivo analysis of patient sera demonstrated only dimeric complexes in circulation.No activation of immune cells by anti-idiotype complexes was observed, and only very large complexes activated complement. Unlike Fc-linked hexamers, anti-idiotype hexamers did not activate complement, demonstrating that besides size, conformation governs immune complex potential for triggering effector functions. CONCLUSIONS: Anti-idiotype ADA-drug complexes generally have restricted immune activation capacity. Large, irregularly shaped complexes only form at high concentrations of both drug and ADA, as may be achieved during intravenous infusion of infliximab, explaining the rarity of serious ADA-associated adverse events. PMID: 29945923 [PubMed - as supplied by publisher]

18 new pubmed citations were retrieved for your search. Click on the search hyperlink below to display the complete search results: metabolomics These pubmed results were generated on 2018/06/27PubMed 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.

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 2018/06/26PubMed 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.

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 2018/06/26PubMed 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.

Related Articles Simultaneous quantification of straight-chain and branched-chain short chain fatty acids by gas chromatography mass spectrometry. J Chromatogr B Analyt Technol Biomed Life Sci. 2018 Jun 18;1092:359-367 Authors: He L, Prodhan MAI, Yuan F, Yin X, Lorkiewicz PK, Wei X, Feng W, McClain C, Zhang X Abstract Biomedical research in areas such as metabolic disorders, neuromodulatory, and immunomodulatory conditions involves lipid metabolism and demands a reliable and inexpensive method for quantification of short chain fatty acids (SCFAs). We report a GC-MS method for analysis of all straight-chain and branched-chain SCFAs using pentafluorobenzyl bromide (PFBBr) as derivatization reagent. We optimized the derivatization and GC-MS conditions using a mixture containing all eight SCFA standards, i.e., five straight-chain and three branched-chain SCFAs. The optimal derivatization conditions were derivatization time 90 min, temperature 60 °C, pH 7, and (CH3)2CO:H2O ratio 2:1 (v:v). Comparing the performance of different GC column configurations, a 30 m DB-225ms hyphenated with a 30 m DB-5ms column in tandem showed the best separation of SCFAs. Using the optimized experiment conditions, we simultaneously detected all SCFAs with much improved detection limit, 0.244-0.977 μM. We further applied the developed method to measure the SCFAs in mouse feces and all SCFAs were successfully quantified. The recovery rates of the eight SCFAs ranged from 55.7% to 97.9%. PMID: 29936372 [PubMed - as supplied by publisher]

Related Articles Isoniazid-induced hepatotoxicity and neurotoxicity in rats investigated by 1H NMR based metabolomics approach. Toxicol Lett. 2018 Jun 21;: Authors: Ruan LY, Fan JT, Hong W, Zhao H, Li MH, Jiang L, Fu YH, Xing YX, Chen C, Wang JS Abstract Isoniazid (INH) is a well-known therapeutic and preventive agent against tuberculosis. However, high rates of side effects with various symptoms concerning hepatotoxicity and neurotoxicity have been reported, hindering its wide and safe application in clinic. In this investigation, rats were intoxicated with INH by gavage at doses of 200 and 400 mg/kg for 7 consecutive days to develop a rat model of acute INH-induced toxicity, which was investigated by a 1H NMR-based metabolomics complemented with clinical assays, histopathological inspection and western blotting. INH decreased the weights of dosed rats and induced seizure and hepatic steatosis dose-dependently. Orthogonal signal correction partial least-squares discriminant analysis (OSC-PLS-DA) of the NMR profiles of rat livers, brains and serum revealed that INH dose-dependently induced oxidative stress, disorders of excitatory and inhibitory amino acid neurotransmitters, and disturbances of energy metabolism and osmotic balance, which could help clarify the mechanisms of INH-induced hepatotoxicity and neurotoxicity. This integrated metabolomics approach showcased its ability to characterize the global metabolic status of organism, providing a powerful and feasible tool to probe drug induced toxicity or side effects. PMID: 29936297 [PubMed - as supplied by publisher]

Related Articles Omics approaches to understand sourdough fermentation processes. Int J Food Microbiol. 2018 Jun 07;: Authors: Weckx S, Van Kerrebroeck S, De Vuyst L Abstract The application of omics methodologies helps to further unravel sourdough fermentation processes. Of all methodologies applied, metagenetics is the most used one to analyse sourdoughs, allowing to elucidate their microbial structure, albeit that it is based on the sequencing of a very small part of whole-community DNA. Although shotgun metagenomics, metatranscriptomics, metaproteomics, and meta-metabolomics are very promising to analyse sourdough fermentations and the terminology is often used in a confusing way, they have not been fully used sensu stricto yet. For instance, up to now, metatranscriptomics is restricted to the use of a functional gene microarray for lactic acid bacteria. Further, meta-metabolomics often deals with metabolite target analysis of sourdough fermentation samples to determine the actual concentrations of residual substrates and metabolites produced as well as to list their volatilome solely. In contrast, genomics has been applied several times, albeit that the whole-genome sequence of only one yeast strain and of 41 lactic acid bacterial strains, originally isolated from sourdoughs, is available. However, the genomics data accessible in public databases should be considered with caution because of inaccurate gene annotations, due to automated annotation pipelines, thereby possibly overruling original, high-quality, well-curated gene annotations. PMID: 29935929 [PubMed - as supplied by publisher]

Related Articles Different milk feeding intensities during the first 4 weeks of rearing dairy calves: Part 3: Plasma metabolomics analysis reveals long-term metabolic imprinting in Holstein heifers. J Dairy Sci. 2018 Jun 20;: Authors: Kenéz Á, Koch C, Korst M, Kesser J, Eder K, Sauerwein H, Huber K Abstract Adequate nutrition of calves is a fundamental requirement for efficient production in later life. Suboptimal nutrition before weaning could have detrimental long-term effects on metabolic health and could thereby decrease production efficiency. In this study, the metabolomic profiles of German Holstein calves reared on whole milk ad libitum (n = 10), milk replacer ad libitum (n = 9), and milk replacer in restricted amounts (n = 9) were compared. Furthermore, this profiling approach was extended to the first lactation in the same animals for characterizing the long-term effect of quantitative and qualitative dietary manipulations affecting calves during development in a period that is sensitive to metabolic imprinting. Blood plasma samples were collected on d 3, 22, and 52 of life as well as during wk 4 before and wk 3 and 8 after the first calving. Samples were subjected to a targeted metabolomics analysis using the AbsoluteIDQ p180 kit of Biocrates Life Science AG (Innsbruck, Austria). Profiling of metabolomics data was performed by principal component analysis and heatmap visualization of the metabolome, as well as by comparing fold changes and t-test statistics of metabolites. A quantitative identification of 180 plasma metabolites was possible, belonging to the metabolite classes of acyl-carnitines, AA, biogenic amines, phosphatidylcholines, lysophosphatidylcholines, sphingomyelins, and hexoses. Comparing metabolite concentrations between ad libitum-reared and restrictively reared animals revealed significant differences both during calfhood as well as during first lactation. Most dominantly, acylcarnitines of both short- and long-chain length were more abundant in ad libitum reared animals in the long-term, suggesting alterations in mitochondrial function, most likely indicating adaptive mechanisms of energy expenditure. Furthermore, plasma sphingomyelin concentrations were affected by ad libitum versus restricted milk replacer feeding, which can imply long-term modulatory mechanisms affecting insulin sensitivity. The functional characterization of the identified metabolic patterns, particularly the alterations of single lipid species, is required for further improving our understanding of the links between early nutrition shaping metabolic development and a healthy productive life of Holstein dairy cows. PMID: 29935828 [PubMed - as supplied by publisher]

Related Articles Re: Laíns et al.: Human plasma metabolomics study across all stages of age-related macular degeneration identifies potential lipid biomarkers (Ophthalmology. 2018;125:245-254). Ophthalmology. 2018 Jul;125(7):e45-e46 Authors: Liu B, Chen S PMID: 29935673 [PubMed - in process]

Related Articles Karenia brevis allelopathy compromises the lipidome, membrane integrity, and photosynthesis of competitors. Sci Rep. 2018 Jun 22;8(1):9572 Authors: Poulin RX, Hogan S, Poulson-Ellestad KL, Brown E, Fernández FM, Kubanek J Abstract The formation, propagation, and maintenance of harmful algal blooms are of interest due to their negative effects on marine life and human health. Some bloom-forming algae utilize allelopathy, the release of compounds that inhibit competitors, to exclude other species dependent on a common pool of limiting resources. Allelopathy is hypothesized to affect bloom dynamics and is well established in the red tide dinoflagellate Karenia brevis. K. brevis typically suppresses competitor growth rather than being acutely toxic to other algae. When we investigated the effects of allelopathy on two competitors, Asterionellopsis glacialis and Thalassiosira pseudonana, using nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry (MS)-based metabolomics, we found that the lipidomes of both species were significantly altered. However, A. glacialis maintained a more robust metabolism in response to K. brevis allelopathy whereas T. pseudonana exhibited significant alterations in lipid synthesis, cell membrane integrity, and photosynthesis. Membrane-associated lipids were significantly suppressed for T. pseudonana exposed to allelopathy such that membranes of living cells became permeable. K. brevis allelopathy appears to target lipid biosynthesis affecting multiple physiological pathways suggesting that exuded compounds have the ability to significantly alter competitor physiology, giving K. brevis an edge over sensitive species. PMID: 29934632 [PubMed - in process]

Related Articles New plasma preparation approach to enrich metabolome coverage in untargeted metabolomics: plasma protein bound hydrophobic metabolite release with proteinase K. Sci Rep. 2018 Jun 22;8(1):9541 Authors: Wawrzyniak R, Kosnowska A, Macioszek S, Bartoszewski R, Jan Markuszewski M Abstract Plasma untargeted metabolomics is a common method for evaluation of the mechanisms underlying human pathologies and identification of novel biomarkers. The plasma proteins provide the environment for transport of hydrophobic metabolites. The current sample preparation protocol relies on the immediate precipitation of proteins and thus leads to co-precipitation of a significant fraction of hydrophobic metabolites. Here we present a new simple procedure that overcomes the co-precipitation problem and improves metabolome coverage. Introducing an additional step preceding the protein precipitation, namely limited digestion with proteinase K, allows release of associated metabolites through the relaxation of the native proteins tertiary structure. The modified protocol allows clear detection of hydrophobic metabolites including fatty acids and phospholipids. Considering the potential involvement of the hydrophobic metabolites in human cardiovascular and cancer diseases, the method may constitute a novel approach in plasma untargeted metabolomics. PMID: 29934622 [PubMed - in process]

Related Articles Pyruvate dehydrogenase complex plays a central role in brown adipocyte energy expenditure and fuel utilization during short-term beta-adrenergic activation. Sci Rep. 2018 Jun 22;8(1):9562 Authors: Held NM, Kuipers EN, van Weeghel M, van Klinken JB, Denis SW, Lombès M, Wanders RJ, Vaz FM, Rensen PCN, Verhoeven AJ, Boon MR, Houtkooper RH Abstract Activation of brown adipose tissue (BAT) contributes to total body energy expenditure through energy dissipation as heat. Activated BAT increases the clearance of lipids and glucose from the circulation, but how BAT accommodates large influx of multiple substrates is not well defined. The purpose of this work was to assess the metabolic fluxes in brown adipocytes during β3-adrenergic receptor (β3-AR) activation.T37i murine preadipocytes were differentiated into brown adipocytes and we used Seahorse respirometry employing a set of specific substrate inhibitors in the presence or absence of β3-AR agonist CL316,243. The main substrate used by these brown adipocytes were fatty acids, which were oxidized equally during activation as well as during resting condition. [U-13C]-glucose tracer-based metabolomics revealed that the flux through the TCA cycle was enhanced and regulated by pyruvate dehydrogenase (PDH) activity. Based on 13C-tracer incorporation in lipids, it appeared that most glucose was oxidized via TCA cycle activity, while some was utilized for glycerol-3-phosphate synthesis to replenish the triglyceride pool. Collectively, we show that while fatty acids are the main substrates for oxidation, glucose is also oxidized to meet the increased energy demand during short term β3-AR activation. PDH plays an important role in directing glucose carbons towards oxidation. PMID: 29934543 [PubMed - in process]

Related Articles Publisher Correction: Thymosin α1 represents a potential potent single-molecule-based therapy for cystic fibrosis. Nat Med. 2018 Jun 22;: Authors: Romani L, Oikonomou V, Moretti S, Iannitti RG, D'Adamo MC, Villella VR, Pariano M, Sforna L, Borghi M, Bellet MM, Fallarino F, Pallotta MT, Servillo G, Ferrari E, Puccetti P, Kroemer G, Pessia M, Maiuri L, Goldstein AL, Garaci E Abstract In the version of this article originally published, the amino acid sequence for Tα1 described in the Online Methods is incorrect. The sequence is described as "Ac-SDAAVDTSSEITTJDLKEKKEVVEEAEN-OH". It should be "Ac-SDAAVDTSSEITTKDLKEKKEVVEEAEN-OH". The error has been corrected in the HTML and PDF versions of this article. PMID: 29934535 [PubMed - as supplied by publisher]

Related Articles Author Correction: Thymosin α1 represents a potential potent single-molecule-based therapy for cystic fibrosis. Nat Med. 2018 Jun 22;: Authors: Romani L, Oikonomou V, Moretti S, Iannitti RG, D'Adamo MC, Villella VR, Pariano M, Sforna L, Borghi M, Bellet MM, Fallarino F, Pallotta MT, Servillo G, Ferrari E, Puccetti P, Kroemer G, Pessia M, Maiuri L, Goldstein AL, Garaci E Abstract In the version of this article originally published, some labels in Fig. 1f are incorrect. The "β-actin" labels on the second and fourth rows of blots should instead be "β-tubulin". The error has been corrected in the HTML and PDF versions of this article. PMID: 29934534 [PubMed - as supplied by publisher]

Related Articles Reference samples guide variable selection for correlation of wine sensory and volatile profiling data. Food Chem. 2018 Nov 30;267:344-354 Authors: Sherman E, Harbertson JF, Greenwood DR, Villas-Bôas SG, Fiehn O, Heymann H Abstract The relationship between wine flavour and wine volatile composition is well recognised, however with thousands of compounds in wine the exact nature of individual contributions may be hard to determine due to synergistic and masking effects. Untargeted chemical analyses coupled with descriptive sensory and partial least squares regression modelling can help unravel interactions to identify groups of compounds that contribute to sensory properties. Variable selection is often applied prior to modelling to eliminate irrelevant variables. In this study, sensory references used to train the sensory panel were chemically analysed and employed to reduce the number of variables used to construct the models. This novel variable selection approach was compared against the inclusion of all variables and the most commonly applied variable selection method - analysis of variance. Models constructed from variables present in sensory references performed similarly to other models and identified interesting groups of compounds to investigate further. PMID: 29934177 [PubMed - in process]

Related Articles New in vitro model derived from brain-specific Mut-/- mice confirms cerebral ammonium accumulation in methylmalonic aciduria. Mol Genet Metab. 2018 Jun 18;: Authors: Remacle N, Forny P, Cudré-Cung HP, Gonzalez-Melo M, do Vale-Pereira S, Henry H, Teav T, Gallart-Ayala H, Braissant O, Baumgartner M, Ballhausen D Abstract BACKGROUND: Methylmalonic aciduria (MMAuria) is an inborn error of metabolism leading to neurological deterioration. In this study, we used 3D organotypic brain cell cultures derived from embryos of a brain-specific Mut-/- (brain KO) mouse to investigate mechanisms leading to brain damage. We challenged our in vitro model by a catabolic stress (temperature shift). RESULTS: Typical metabolites for MMAuria as well as a massive NH4+ increase were found in the media of brain KO cultures. We investigated different pathways of intracerebral NH4+ production and found increased expression of glutaminase 2 and diminished expression of GDH1 in Mut-/- aggregates. While all brain cell types appeared affected in their morphological development in Mut-/- aggregates, the most pronounced effects were observed on astrocytes showing swollen fibers and cell bodies. Inhibited axonal elongation and delayed myelination of oligodendrocytes were also noted. Most effects were even more pronounced after 48 h at 39 °C. Microglia activation and an increased apoptosis rate suggested degeneration of Mut-/- brain cells. NH4+ accumulation might be the trigger for all observed alterations. We also found a generalized increase of chemokine concentrations in Mut-/- culture media at an early developmental stage followed by a decrease at a later stage. CONCLUSION: We proved for the first time that Mut-/- brain cells are indeed able to produce the characteristic metabolites of MMAuria. We confirmed significant NH4+ accumulation in culture media of Mut-/- aggregates, suggesting that intracellular NH4+ concentrations might even be higher, gave first clues on the mechanisms leading to NH4+ accumulation in Mut-/- brain cells, and showed the involvement of neuroinflammatory processes in the neuropathophysiology of MMAuria. PMID: 29934063 [PubMed - as supplied by publisher]

Related Articles Metabolomic and BH3 profiling of esophageal cancers: novel assessment methods for precision therapy. BMC Gastroenterol. 2018 Jun 22;18(1):94 Authors: Taylor Ripley R, Surman DR, Diggs LP, Trepel JB, Lee MJ, Ryan J, Davis JL, Steinberg SM, Hernandez JM, Hoang C, Kenney CM, Bond CD, Kunst TF, Letai A, Schrump DS Abstract BACKGROUND: Esophageal cancers accounted for nearly 16,000 deaths in 2016. The number of patients with esophageal cancers increases every year. Neoadjuvant chemoradiotherapy (nCRT) prior to esophagectomy is a standard treatment for esophageal cancers. The patients who have no residual tumor (pathological complete response (pCR)) at surgery are the most likely to experience long term survival. Accurately determining which patients will have a pCR will improve prognostic information for patients and families, confirm lack of response to nCRT, or avoid surgery if no residual tumor is present. Imaging, endoscopy, and liquid biomarkers have all failed to detect pCR without performing an esophagectomy. METHODS: In this study, we are enrolling patients with esophageal adenocarcinoma and squamous cell carcinoma. Patients will undergo standard evaluation including CT scans, laboratory tests, endoscopy with biopsies, and evaluation by a thoracic surgeon. Tissue biopsy is required for enrollment that will be sent for BH3 profiling and metabolomics. Patients will be treated with standard nCRT followed by surgery. Patients with metastatic disease are not eligible. Surgery at the National Cancer Institute will be minimally-invasive robotic surgery. Patients will remain on study indefinitely with regular clinic visits and imaging tests. DISCUSSION: The mitochondria are critically involved in the intrinsic pathway apoptosis. Bcl-2 homology domain 3 (BH3) profiling is a technique to measure a cell's susceptibility to apoptosis. BH3 profiling measures the relative interactions of proteins that induce or block apoptosis. The collective balance of these proteins determines whether a cell is near the threshold to undergo apoptosis. If the cell is near this threshold, then the tumor may be more likely to die when treated with nCRT. The mitochondria secrete metabolites that may be detectable as biomarkers. Metabolomics is a global assessment of all metabolite changes that has been performed for detection, monitoring, prognosis, and treatment response in cancers. Stratification of patients based on whether pCR occurs or not may elucidate metabolomic signatures that may be associated with response. We are asking whether BH3 profiling or a metabolomic signature will correlate with tumor death after nCRT for esophageal cancer. TRIAL REGISTRATION: NCT03223662 ; Clinicaltrials.gov. July 21, 2017. PMID: 29933761 [PubMed - in process]