Feedback inhibition of ammonium (methylammonium) ion transport in Escherichia coli by glutamine and glutamine analogs

International Nuclear Information System (INIS)

Jayakumar, A.; Hong, J.S.; Barnes, E.M. Jr.

1987-01-01

When cultured with glutamate or glutamine as the nitrogen source, Escherichia coli expresses a specific ammonium (methylammonium) transport system. Over 95% of the methylammonium transport activity in washed cells was blocked by incubation with 100 μM L-glutamine in the presence of chloramphenicol (100 μg/ml). The inhibition of transport by L-glutamine was noncompetitive with respect to the [ 14 C]methylammonium substrate. D-Glutamine had no significant effect. The glutamine analogs γ-L-glutamyl hydroxamate and γ-L-glutamyl hydrazide were also noncompetitive inhibitors of methylammonium transport, suggesting that glutamine metabolism is not required. The role of the intracellular glutamine pool in the regulation of ammonium transport was investigated by using mutants carrying defects in the operon of glnP, the gene for the glutamine transporter. The glnP mutants had normal rates of methylammonium transport but were refractory to glutamine inhibition. Glycylglycine, a noncompetitive inhibitor of methylammonium uptake in wild-type cells, was equipotent in blocking transport in glnP mutants. Although ammonium transport is also subject to repression by growth of E. coli in the presence of ammonia, this phenomenon is unrelated to glutamine inhibition

The Effect of Single Portion Glutamine Supplement Consumption on Injury Indices of Muscle After Eccentric Resistance Exercise

OpenAIRE

Azadeh Najarzadeh; Hadi Atarod; Hasan Mozaffari-Khosravi; Ali Dehghani; Foad Asjodi

2015-01-01

Abstract Background: Delayed muscular soreness after resistance exercises or eccentric trainings is probably because of muscle damage and injury. Nutrition by playing a crucial role in both protein synthesize and catabolism can influence the extent of muscle injury. The objective of this study was to assess the effect of single portion of Glutamine supplement consumption on injury indices of muscle after a session eccentric resistance exercise. Materials and Methods: this study used a ...

The Glutamine Transporters and Their Role in the Glutamate/GABA-Glutamine Cycle

DEFF Research Database (Denmark)

Leke, Renata; Schousboe, Arne

2016-01-01

in this neural communication, i.e., the transporters responsible for glutamine efflux from astrocytes and influx into the neurons, such as the members of the SNAT, LAT, y(+)LAT, and ASC families of transporters. The SNAT family consists of the transporter isoforms SNAT3 and SNAT5 that are related to efflux from......Glutamine is a key amino acid in the CNS, playing an important role in the glutamate/GABA-glutamine cycle (GGC). In the GGC, glutamine is transferred from astrocytes to neurons, where it will replenish the inhibitory and excitatory neurotransmitter pools. Different transporters participate...... the astrocytic compartment, and SNAT1 and SNAT2 that are associated with glutamine uptake into the neuronal compartment. The isoforms SNAT7 and SNAT8 do not have their role completely understood, but they likely also participate in the GGC. The isoforms LAT2 and y(+)LAT2 facilitate the exchange of neutral amino...

Similar Responses of Intestinal T Cells From Untreated Children and Adults With Celiac Disease to Deamidated Gluten Epitopes.

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Ráki, Melinda; Dahal-Koirala, Shiva; Yu, Hao; Korponay-Szabó, Ilma R; Gyimesi, Judit; Castillejo, Gemma; Jahnsen, Jørgen; Qiao, Shuo-Wang; Sollid, Ludvig M

2017-09-01

Celiac disease is a chronic small intestinal inflammatory disorder mediated by an immune response to gluten peptides in genetically susceptible individuals. Celiac disease is often diagnosed in early childhood, but some patients receive a diagnosis late in life. It is uncertain whether pediatric celiac disease is distinct from adult celiac disease. It has been proposed that gluten-reactive T cells in children recognize deamidated and native gluten epitopes, whereas T cells from adults only recognize deamidated gluten peptides. We studied the repertoire of gluten epitopes recognized by T cells from children and adults. We examined T-cell responses against gluten by generating T-cell lines and T-cell clones from intestinal biopsies of adults and children and tested proliferative response to various gluten peptides. We analyzed T cells from 14 children (2-5 years old) at high risk for celiac disease who were followed for celiac disease development. We also analyzed T cells from 6 adults (26-55 years old) with untreated celiac disease. All children and adults were positive for HLA-DQ2.5. Biopsies were incubated with gluten digested with chymotrypsin (modified or unmodified by the enzyme transglutaminase 2) or the peptic-tryptic digest of gliadin (in native and deamidated forms) before T-cell collection. Levels of T-cell responses were higher to deamidated gluten than to native gluten in children and adults. T cells from children and adults each reacted to multiple gluten epitopes. Several T-cell clones were cross-reactive, especially clones that recognized epitopes from γ-and ω-gliadin. About half of the generated T-cell clones from children and adults reacted to unknown epitopes. T-cell responses to different gluten peptides appear to be similar between adults and children at the time of diagnosis of celiac disease. Copyright © 2017 AGA Institute. Published by Elsevier Inc. All rights reserved.

Glutamine Synthetase: Localization Dictates Outcome

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Alessandra Castegna

2018-02-01

Full Text Available Glutamine synthetase (GS is the adenosine triphosphate (ATP-dependent enzyme that catalyses the synthesis of glutamine by condensing ammonium to glutamate. In the circulatory system, glutamine carries ammonia from muscle and brain to the kidney and liver. In brain reduction of GS activity has been suggested as a mechanism mediating neurotoxicity in neurodegenerative disorders. In cancer, the delicate balance between glutamine synthesis and catabolism is a critical event. In vitro evidence, confirmed in vivo in some cases, suggests that reduced GS activity in cancer cells associates with a more invasive and aggressive phenotype. However, GS is known to be highly expressed in cells of the tumor microenvironment, such as fibroblasts, adipocytes and immune cells, and their ability to synthesize glutamine is responsible for the acquisition of protumoral phenotypes. This has opened a new window into the complex scenario of the tumor microenvironment, in which the balance of glutamine consumption versus glutamine synthesis influences cellular function. Since GS expression responds to glutamine starvation, a lower glutamine synthesizing power due to the absence of GS in cancer cells might apply a metabolic pressure on stromal cells. This event might push stroma towards a GS-high/protumoral phenotype. When referred to stromal cells, GS expression might acquire a ‘bad’ significance to the point that GS inhibition might be considered a conceivable strategy against cancer metastasis.

Glutamine supplementation maintains intramuscular glutamine concentrations and normalizes lymphocyte function in infected early weaned pigs.

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Yoo, S S; Field, C J; McBurney, M I

1997-11-01

Numerous studies in humans and rats have shown that glutamine supplementation during stressful conditions has favorable outcomes. However, the requirements for glutamine during weaning are unknown. Thus, the effects of glutamine supplementation in healthy and infected weaned pigs were investigated. At 21 d of age, pigs were weaned to an elemental diet supplemented with glutamine (+Gln) or an isonitrogenous diet containing nonessential amino acids (-Gln). At 26 d of age, pigs were intraperitoneally injected with Escherichia coli (+Ecoli) or buffered saline (-Ecoli) and killed at 28 d of age. Infection decreased (P Ecoli+Gln pigs were greater (P Ecoli-Gln pigs and not different than those of noninfected pigs. Hence, glutamine supplementation maintained muscular glutamine concentrations and normalized lymphocyte function in infected pigs.

The Glutamine Transporters and Their Role in the Glutamate/GABA-Glutamine Cycle

DEFF Research Database (Denmark)

Leke, Renata; Schousboe, Arne

2016-01-01

in this neural communication, i.e., the transporters responsible for glutamine efflux from astrocytes and influx into the neurons, such as the members of the SNAT, LAT, y(+)LAT, and ASC families of transporters. The SNAT family consists of the transporter isoforms SNAT3 and SNAT5 that are related to efflux from...... and translational mechanisms, which are induced by several determinants such as amino acid deprivation, hormones, pH, and the activity of different signaling pathways. Dysfunctional glutamine transporter activity has been associated with the pathophysiological mechanisms of certain neurologic diseases......, such as Hepatic Encephalopathy and Manganism. However, there might also be other neuropathological conditions associated with an altered GGC, in which glutamine transporters are dysfunctional. Hence, it appears to be of critical importance that the physiological and pathological aspects of glutamine transporters...

The Glutamine-Glutamate/GABA Cycle

DEFF Research Database (Denmark)

Walls, Anne B; Waagepetersen, Helle S; Bak, Lasse Kristoffer

2015-01-01

information about glutamine transfer. The present review will give information about glutamine trafficking and the tools used to map it as exemplified by discussions of published work employing brain cell cultures as well as intact animals. It will be documented that considerably more glutamine is transferred...

The production and crystallization of the human leukocyte antigen class II molecules HLA-DQ2 and HLA-DQ8 complexed with deamidated gliadin peptides implicated in coeliac disease

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Henderson, Kate N.; Reid, Hugh H.; Borg, Natalie A.; Broughton, Sophie E.; Huyton, Trevor [The Protein Crystallography Unit, Department of Biochemistry and Molecular Biology, School of Biomedical Sciences, Monash University, Clayton, Victoria 3800 (Australia); Anderson, Robert P. [Autoimmunity and Transplantation Division, Walter and Eliza Hall Institute, 1G Royal Parade, Parkville, Victoria 3050 (Australia); Department of Gastroenterology, The Royal Melbourne Hospital, Grattan Street, Parkville, Victoria 3050 (Australia); McCluskey, James [Department of Microbiology and Immunology, University of Melbourne, Parkville, Victoria 3010 (Australia); Rossjohn, Jamie, E-mail: jamie.rossjohn@med.monash.edu.au [The Protein Crystallography Unit, Department of Biochemistry and Molecular Biology, School of Biomedical Sciences, Monash University, Clayton, Victoria 3800 (Australia)

2007-12-01

The production and crystallization of human leukocyte antigen class II molecules HLA-DQ2 and HLA-DQ8 in complex with deamidated gliadin peptides is reported. Crystals of HLA-DQ2{sup PQPELPYPQ} diffracted to 3.9 Å, while the HLA-DQ8{sup EGSFQPSQE} crystals diffracted to 2.1 Å, allowing structure determination by molecular replacement. The major histocompatibility complex (MHC) class II molecules HLA-DQ2 and HLA-DQ8 are key risk factors in coeliac disease, as they bind deamidated gluten peptides that are subsequently recognized by CD4{sup +} T cells. Here, the production and crystallization of both HLA-DQ2 and HLA-DQ8 in complex with the deamidated gliadin peptides DQ2 α-I (PQPELPYPQ) and DQ8 α-I (EGSFQPSQE), respectively, are reported.

Plasma Glutamine Concentrations in Liver Failure.

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Gunnel Helling

Full Text Available Higher than normal plasma glutamine concentration at admission to an intensive care unit is associated with an unfavorable outcome. Very high plasma glutamine levels are sometimes seen in both acute and chronic liver failure. We aimed to systematically explore the relation between different types of liver failure and plasma glutamine concentrations.Four different groups of patients were studies; chronic liver failure (n = 40, acute on chronic liver failure (n = 20, acute fulminant liver failure (n = 20, and post-hepatectomy liver failure (n = 20. Child-Pugh and Model for End-stage Liver Disease (MELD scores were assessed as indices of liver function. All groups except the chronic liver failure group were followed longitudinally during hospitalisation. Outcomes were recorded up to 48 months after study inclusion.All groups had individuals with very high plasma glutamine concentrations. In the total group of patients (n = 100, severity of liver failure correlated significantly with plasma glutamine concentration, but the correlation was not strong.Liver failure, regardless of severity and course of illness, may be associated with a high plasma glutamine concentration. Further studies are needed to understand whether high glutamine levels should be regarded as a biomarker or as a contributor to symptomatology in liver failure.

Amide to Alkyne Interconversion via a Nickel/Copper-Catalyzed Deamidative Cross-Coupling of Aryl and Alkenyl Amides.

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Srimontree, Watchara; Chatupheeraphat, Adisak; Liao, Hsuan-Hung; Rueping, Magnus

2017-06-16

A nickel-catalyzed deamidative cross-coupling reaction of amides with terminal alkynes as coupling partners was disclosed. This newly developed methodology allows the direct interconversion of amides to alkynes and enables a facile route for C(sp2)-C(sp) bond formation in a straightforward and mild fashion.

Amide to Alkyne Interconversion via a Nickel/Copper-Catalyzed Deamidative Cross-Coupling of Aryl and Alkenyl Amides

KAUST Repository

Srimontree, Watchara; Chatupheeraphat, Adisak; Liao, Hsuan-Hung; Rueping, Magnus

2017-01-01

A nickel-catalyzed deamidative cross-coupling reaction of amides with terminal alkynes as coupling partners was disclosed. This newly developed methodology allows the direct interconversion of amides to alkynes and enables a facile route for C(sp2)-C(sp) bond formation in a straightforward and mild fashion.

Amide to Alkyne Interconversion via a Nickel/Copper-Catalyzed Deamidative Cross-Coupling of Aryl and Alkenyl Amides

KAUST Repository

Srimontree, Watchara

2017-06-05

A nickel-catalyzed deamidative cross-coupling reaction of amides with terminal alkynes as coupling partners was disclosed. This newly developed methodology allows the direct interconversion of amides to alkynes and enables a facile route for C(sp2)-C(sp) bond formation in a straightforward and mild fashion.

Glutaminase enzyme biosensor for determination of glutamine in cerebrospinal fluid, human serum and l-glutamine capsule

International Nuclear Information System (INIS)

Bagriyanik, D.B.; Karakus, E

2014-01-01

Ammonium-selective glutamine biosensor was prepared by immobilizing glutaminase on poly(vinylchloride) (PVC) ammonium membrane electrode containing palmitic acid prepared by using nonactine. The response of glutamine biosensor was linear over the concentration range of 1.0x10-11.0x10-4M and slope was Nernstian. We determined optimum working conditions of the biosensor such as buffer concentration, buffer pH, lifetime, response time, linear working range and other response characteristics. The optimum buffer concentration and pH of proposed glutamine biosensor were determined as 20mM and pH 7.5, respectively. The interference effects of some ions and amino acids that may be present in body fluids were also investigated. The Km and Vmax values of glutaminase were determined. Additionally, glutamine assay in several biological samples such as healthy human serum, cerebrospinal fluid (CSF) and commercial glutamine capsule were also successfully carried out by using the standard addition method. The results were good agreement with previously reported values. (author)

Glutamine supplementation suppresses herpes simplex virus reactivation.

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Wang, Kening; Hoshino, Yo; Dowdell, Kennichi; Bosch-Marce, Marta; Myers, Timothy G; Sarmiento, Mayra; Pesnicak, Lesley; Krause, Philip R; Cohen, Jeffrey I

2017-06-30

Chronic viral infections are difficult to treat, and new approaches are needed, particularly those aimed at reducing reactivation by enhancing immune responses. Herpes simplex virus (HSV) establishes latency and reactivates frequently, and breakthrough reactivation can occur despite suppressive antiviral therapy. Virus-specific T cells are important to control HSV, and proliferation of activated T cells requires increased metabolism of glutamine. Here, we found that supplementation with oral glutamine reduced virus reactivation in latently HSV-1-infected mice and HSV-2-infected guinea pigs. Transcriptome analysis of trigeminal ganglia from latently HSV-1-infected, glutamine-treated WT mice showed upregulation of several IFN-γ-inducible genes. In contrast to WT mice, supplemental glutamine was ineffective in reducing the rate of HSV-1 reactivation in latently HSV-1-infected IFN-γ-KO mice. Mice treated with glutamine also had higher numbers of HSV-specific IFN-γ-producing CD8 T cells in latently infected ganglia. Thus, glutamine may enhance the IFN-γ-associated immune response and reduce the rate of reactivation of latent virus infection.

Exploring Biological and Geological Age-related Changes through Variations in Intra- and Intertooth Proteomes of Ancient Dentine.

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Procopio, Noemi; Chamberlain, Andrew T; Buckley, Michael

2018-03-02

Proteomic analyses are becoming more widely used in archeology not only due to the greater preservation of proteins in ancient specimens than DNA but also because they can offer different information, particularly relating to compositional preservation and potentially a means to estimate biological and geological age. However, it remains unclear to what extent different burial environments impact these aspects of proteome decay. Teeth have to date been much less studied than bone but are ideal to explore how proteins decay with time due to the negligible turnover that occurs in dentine relative to bone. We investigated the proteome variability and deamidation levels of different sections of molar teeth from archeological bovine mandibles as well as their mandibular bone. We obtained a greater yield of proteins from the crown of the teeth but did not find differences between the different molars analyzed within each mandible. We also obtained the best variety of protein from a well-preserved mandible that was not the youngest one in terms of chronological age, showing the influence of the preservation conditions on the final proteomic outcome. Intriguingly, we also noticed an increase in abundance levels of fetuin-A in biologically younger mandibles as reported previously, but the opposite trend in tooth dentine. Interestingly, we observed higher glutamine deamidation levels in teeth from the geologically oldest mandible despite it being the biologically youngest specimen, showing that the archeological age strongly impacts on the level of deamidations observed, much more so than biological aging. This indicates that the glutamine deamidation ratio of selected peptides may act as a good predictor of the relative geochronological age of archeological specimens.

The effect of glutamine administration on urinary ammonium excretion in normal subjects and patients with renal disease.

Science.gov (United States)

Welbourne, T; Weber, M; Bank, N

1972-07-01

The effect of acute changes in the delivery rate of glutamine to the kidney on urinary ammonium excretion was studied in man. Healthy subjects and patients with intrinsic renal disease were studied under three different acid-base conditions: unaltered acid-base balance; NH(4)Cl-induced acidosis; and NaHCO(3)-induced alkalosis. Anhydrous L-glutamine was administered orally in a single dose of 260 mmoles during each of these three acid-base states. We found that endogenous venous plasma glutamine concentration fell during acidosis and rose during alkalosis in both healthy subjects and patients with renal disease. In healthy subjects, orally administered glutamine raised plasma glutamine concentration markedly over a 2-3 hr period. This was accompanied by an increase in urinary ammonium excretion and a rise in urine pH under normal acid-base conditions and during metabolic acidosis. No increase in ammonium excretion occurred when glutamine was administered during metabolic alkalosis in spite of an equivalent rise in plasma glutamine concentration. In patients with renal disease, endogenous venous plasma glutamine concentration was lower than in healthy subjects, perhaps as a result of mild metabolic acidosis. Acute oral glutamine loading failed to increase urinary ammonium excretion significantly during either unaltered acid-base conditions or after NH(4)Cl-induced acidosis, even though plasma glutamine rose as high as in healthy subjects. We conclude from these observations that glutamine delivery to the kidney is a rate-limiting factor for ammonium excretion in healthy subjects, both before and after cellular enzyme adaptation induced by metabolic acidosis. In contrast, in patients with renal disease, glutamine delivery is not rate-limiting for ammonium excretion. Presumably other factors, such as surviving renal mass and the activity of intracellular enzymes necessary for ammonia synthesis limit ammonium excretion in these patients.

Detection of specific IgA antibodies against a novel deamidated 8-Mer gliadin peptide in blood plasma samples from celiac patients.

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Sara Vallejo-Diez

Full Text Available We studied whether celiac disease (CD patients produce antibodies against a novel gliadin peptide specifically generated in the duodenum of CD patients by a previously described pattern of CD-specific duodenal proteases. Fingerprinting and ion-trap mass spectrometry of CD-specific duodenal gliadin-degrading protease pattern revealed a new 8-mer gliadin-derived peptide. An ELISA against synthetic deamidated 8-mer peptides (DGP 8-mer was used to study the presence of IgA anti-DGP 8-mer antibodies in plasma samples from 81 children (31 active CD patients (aCD, 17 CD patients on a gluten-free diet (GFD, 10 healthy controls (C and 23 patients with other gastrointestinal pathology (GP and 101 adults (16 aCD, 12 GFD, 27 C and 46 GP-patients. Deamidation of the 8-mer peptide significantly increased the reactivity of the IgA antibodies from CD patients against the peptide. Significant IgA anti-DGP 8-mer antibodies levels were detected in 93.5% of aCD-, 11.8% of GFD- and 4.3% of GP-patients in children. In adults, antibodies were detected in 81.3% of aCD-patients and 8.3% of GFD-patients while were absent in 100% of C- and GP-patients. Duodenal CD-specific gliadin degrading proteases release an 8-mer gliadin peptide that once deamidated is an antigen for specific IgA antibodies in CD patients which may provide a new accurate diagnostic tool in CD.

Nutrition Modulation of Cardiotoxicity and Anticancer Efficacy Related to Doxorubicin Chemotherapy by Glutamine and ω-3 Polyunsaturated Fatty Acids

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Xue, Hongyu; Ren, Wenhua; Denkinger, Melanie; Schlotzer, Ewald; Wischmeyer, Paul E.

2015-01-01

Background Doxorubicin (DOX) has been one of the most effective antitumor agents against a broad spectrum of malignancies. However, DOX-induced cardiotoxicity forms the major cumulative dose-limiting factor. Glutamine and ω-3 polyunsaturated fatty acids (PUFAs) are putatively cardioprotective during various stresses and/or have potential chemosensitizing effects during cancer chemotherapy. Methods Antitumor activity and cardiotoxicity of DOX treatment were evaluated simultaneously in a MatBIII mammary adenocarcinoma tumor-bearing rat model treated with DOX (cumulative dose 12 mg/kg). Single or combined treatment of parenteral glutamine (0.35 g/kg) and ω-3 PUFAs (0.19 g/kg eicosapentaenoic acid and 0.18 g/kg docosahexaenoic acid) was administered every other day, starting 6 days before chemotherapy initiation until the end of study (day 50). Results Glutamine alone significantly prevented DOX-related deterioration of cardiac function, reduced serum cardiac troponin I levels, and diminished cardiac lipid peroxidation while not affecting tumor inhibition kinetics. Single ω-3 PUFA treatment significantly enhanced antitumor activity of DOX associated with intensified tumoral oxidative stress and enhanced tumoral DOX concentration while not potentiating cardiac dysfunction or increasing cardiac oxidative stress. Intriguingly, providing glutamine and ω-3 PUFAs together did not consistently confer a greater benefit; conversely, individual benefits on cardiotoxicity and chemosensitization were mostly attenuated or completely lost when combined. Conclusions Our data demonstrate an interesting differentiality or even dichotomy in the response of tumor and host to single parenteral glutamine and ω-3 PUFA treatments. The intriguing glutamine × ω-3 PUFA interaction observed draws into question the common assumption that there are additive benefits of combinations of nutrients that are beneficial on an individual basis. PMID:25888676

Introduction to the Glutamate-Glutamine Cycle

DEFF Research Database (Denmark)

Sonnewald, Ursula; Schousboe, Arne

2016-01-01

. This is metabolically impossible unless it is assumed that at least two distinct pools of these amino acids exist. This combined with the finding that the enzyme synthesizing glutamine from glutamate was expressed in astrocytes but not in neurons formed the basis of the notion that a cycle must exist in which glutamate......The term 'glutamate-glutamine cycle' was coined several decades ago based on the observation that using certain (14)C-labeled precursors for studies of brain metabolism the specific radioactivity of glutamine generated from glutamate was higher than that of glutamate, its immediate precursor...... released from neurons is transported into astrocytes, converted to glutamine which is subsequently returned to neurons and converted to glutamate by an enzyme the activity of which is much higher in neurons than in astrocytes. Originally this cycle was supposed to function in a stoichiometric fashion...

Introduction to the Glutamate-Glutamine Cycle

DEFF Research Database (Denmark)

Sonnewald, Ursula; Schousboe, Arne

2016-01-01

released from neurons is transported into astrocytes, converted to glutamine which is subsequently returned to neurons and converted to glutamate by an enzyme the activity of which is much higher in neurons than in astrocytes. Originally this cycle was supposed to function in a stoichiometric fashion......The term 'glutamate-glutamine cycle' was coined several decades ago based on the observation that using certain (14)C-labeled precursors for studies of brain metabolism the specific radioactivity of glutamine generated from glutamate was higher than that of glutamate, its immediate precursor....... This is metabolically impossible unless it is assumed that at least two distinct pools of these amino acids exist. This combined with the finding that the enzyme synthesizing glutamine from glutamate was expressed in astrocytes but not in neurons formed the basis of the notion that a cycle must exist in which glutamate...

Determination of glutamine and glutamic acid in mammalian cell cultures using tetrathiafulvalene modified enzyme electrodes.

Science.gov (United States)

Mulchandani, A; Bassi, A S

1996-01-01

Tetrathiafulvalene (TTF) mediated amperometric enzyme electrodes have been developed for the monitoring of L-glutamine and L-glutamic acid in growing mammalian cell cultures. The detection of glutamine was accomplished by a coupled enzyme system comprised of glutaminase plus glutamate oxidase, while the detection of glutamic acid was carried out by a single enzyme, glutamate oxidase. The appropriate enzyme(s) were immoblized on the Triton-X treated surface of tetrathiafulvalene modified carbon paste electrodes by adsorption, in conjunction with entrapment by an electrochemically deposited copolymer film of 1,3-phenylenediamine and resorcinol. Operating conditions for the glutamine enzyme electrode were optimized with respect to the amount of enzymes immoblized, pH, temperature and mobile phase flow rate for operation in a flow injection (FIA) system. When applied to glutamine and glutamic acid measurements in mammalian cell culture in FIA, the results obtained with enzyme electrodes were in excellent agreement with those determined by enzymatic analysis.

Glutamine and glutamate: Nonessential or essential amino acids?

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Malcolm Watford

2015-09-01

Full Text Available Glutamine and glutamate are not considered essential amino acids but they play important roles in maintaining growth and health in both neonates and adults. Although glutamine and glutamate are highly abundant in most feedstuffs there is increasing evidence that they may be limiting during pregnancy, lactation and neonatal growth, particularly when relatively low protein diets are fed. Supplementation of diets with glutamine, glutamate or both at 0.5 to 1.0% to both suckling and recently weaned piglets improves intestinal and immune function and results in better growth. In addition such supplementation to the sow prevents some of the loss of lean body mass during lactation, and increases milk glutamine content. However, a number of important questions related to physiological condition, species under study and the form and amount of the supplements need to be addressed before the full benefits of glutamine and glutamate supplementation in domestic animal production can be realized. Keywords: Amino acid, Glutamate, Glutamine, Lactation, Pregnancy, Growth

Endogenous glutamine decrease is associated with pancreatic cancer progression.

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Roux, Cecilia; Riganti, Chiara; Borgogno, Sammy Ferri; Curto, Roberta; Curcio, Claudia; Catanzaro, Valeria; Digilio, Giuseppe; Padovan, Sergio; Puccinelli, Maria Paola; Isabello, Monica; Aime, Silvio; Cappello, Paola; Novelli, Francesco

2017-11-10

Pancreatic ductal adenocarcinoma (PDAC) is becoming the second leading cause of cancer-related death in the Western world. The mortality is very high, which emphasizes the need to identify biomarkers for early detection. As glutamine metabolism alteration is a feature of PDAC, its in vivo evaluation may provide a useful tool for biomarker identification. Our aim was to identify a handy method to evaluate blood glutamine consumption in mouse models of PDAC. We quantified the in vitro glutamine uptake by Mass Spectrometry (MS) in tumor cell supernatants and showed that it was higher in PDAC compared to non-PDAC tumor and pancreatic control human cells. The increased glutamine uptake was paralleled by higher activity of most glutamine pathway-related enzymes supporting nucleotide and ATP production. Free glutamine blood levels were evaluated in orthotopic and spontaneous mouse models of PDAC and other pancreatic-related disorders by High-Performance Liquid Chromatography (HPLC) and/or MS. Notably we observed a reduction of blood glutamine as much as the tumor progressed from pancreatic intraepithelial lesions to invasive PDAC, but was not related to chronic pancreatitis-associated inflammation or diabetes. In parallel the increased levels of branched-chain amino acids (BCAA) were observed. By contrast blood glutamine levels were stable in non-tumor bearing mice. These findings demonstrated that glutamine uptake is measurable both in vitro and in vivo . The higher in vitro avidity of PDAC cells corresponded to a lower blood glutamine level as soon as the tumor mass grew. The reduction in circulating glutamine represents a novel tool exploitable to implement other diagnostic or prognostic PDAC biomarkers.

Plasma glutamine levels before cardiac surgery are related to post-surgery infections; an observational study

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Hanneke Buter

2016-11-01

Full Text Available Abstract Background A low plasma glutamine level was found in 34% of patients after elective cardiothoracic surgery. This could be a result of the inflammation caused by surgical stress or the use of extracorporeal circulation (ECC. But it is also possible that plasma glutamine levels were already lowered before surgery and reflect an impaired metabolic state and a higher likelihood to develop complications. In the present study plasma glutamine levels were measured before and after cardiac surgery and we questioned whether there is a relation between plasma glutamine levels and duration of ECC and the occurrence of postoperative infections. Methods We performed a single-centre prospective, observational study in a closed-format, 20-bed, mixed ICU in a tertiary teaching hospital. We included consecutive patients after elective cardiac surgery with use of extracorporeal circulation. Blood samples were collected on the day prior to surgery and at admission on the ICU. The study was approved by the local Medical Ethics Committee (Regional Review Committee Patient-related Research, Medical Centre Leeuwarden, nWMO 115, April 28th 2015. Results Ninety patients were included. Pre-operative plasma glutamine level was 0.42 ± 0.10 mmol/l and post-operative 0.38 ± 0.09 mmol/l (p < 0.001. There was no relation between duration of extracorporeal circulation or aortic occlusion time and changes in plasma glutamine levels. A logistic regression analysis showed a significant correlation between the presence of a positive culture during the post-operative course and pre-operative plasma glutamine levels (p = 0.04. Conclusion Plasma glutamine levels are significantly lower just after cardiac surgery compared to pre-operative levels. We did not find a relation between the decrease in plasma glutamine levels and the duration of extracorporeal circulation or aortic clamp time. There was a correlation between pre-operative plasma glutamine levels

Introduction to the Glutamate-Glutamine Cycle.

Science.gov (United States)

Sonnewald, Ursula; Schousboe, Arne

2016-01-01

The term 'glutamate-glutamine cycle' was coined several decades ago based on the observation that using certain 14 C-labeled precursors for studies of brain metabolism the specific radioactivity of glutamine generated from glutamate was higher than that of glutamate, its immediate precursor. This is metabolically impossible unless it is assumed that at least two distinct pools of these amino acids exist. This combined with the finding that the enzyme synthesizing glutamine from glutamate was expressed in astrocytes but not in neurons formed the basis of the notion that a cycle must exist in which glutamate released from neurons is transported into astrocytes, converted to glutamine which is subsequently returned to neurons and converted to glutamate by an enzyme the activity of which is much higher in neurons than in astrocytes. Originally this cycle was supposed to function in a stoichiometric fashion but more recent research has seriously questioned this.This volume of Advances in Neurobiology is intended to provide a detailed discussion of recent developments in research aimed at delineating the functional roles of the cycle taking into account that in order for this system to work there must be a tight coupling between metabolism of glutamate in astrocytes, transfer of glutamine to neurons and de novo synthesis of glutamine in astrocytes. To understand this, knowledge about the activity and regulation of the enzymes and transporters involved in these processes is required and as can be seen from the table of contents these issues will be dealt with in detail in the individual chapters of the book.

GLUTAMINE AND HYPERAMMONEMIC CRISES IN PATIENTS WITH UREA CYCLE DISORDERS

Science.gov (United States)

Lee, B.; Diaz, G.A.; Rhead, W.; Lichter-Konecki, U.; Feigenbaum, A.; Berry, S.A.; Le Mons, C.; Bartley, J.; Longo, N.; Nagamani, S.C.; Berquist, W.; Gallagher, R.C.; Harding, C.O.; McCandless, S.E.; Smith, W.; Schulze, A.; Marino, M.; Rowell, R.; Coakley, D.F.; Mokhtarani, M.; Scharschmidt, B.F.

2016-01-01

Blood ammonia and glutamine levels are used as biomarkers of control in patients with urea cycle disorders (UCDs). This study was undertaken to evaluate glutamine variability and utility as a predictor of hyperammonemic crises (HACs) in UCD patients. Methods The relationships between glutamine and ammonia levels and the incidence and timing of HACs were evaluated in over 100 adult and pediatric UCD patients who participated in clinical trials of glycerol phenylbutyrate. Results The median (range) intra-subject 24-hour coefficient of variation for glutamine was 15% (8–29%) as compared with 56% (28%–154%) for ammonia, and the correlation coefficient between glutamine and concurrent ammonia levels varied from 0.17 to 0.29. Patients with baseline (fasting) glutamine values >900 µmol/L had higher baseline ammonia levels (mean [SD]: 39.6 [26.2] µmol/L) than patients with baseline glutamine ≤900 µmol/L (26.6 [18.0] µmol/L). Glutamine values >900 µmol/L during the study were associated with an approximately 2-fold higher HAC risk (odds ratio [OR]=1.98; p=0.173). However, glutamine lost predictive significance (OR=1.47; p=0.439) when concomitant ammonia was taken into account, whereas the predictive value of baseline ammonia ≥ 1.0 upper limit of normal (ULN) was highly statistically significant (OR=4.96; p=0.013). There was no significant effect of glutamine >900 µmol/L on time to first HAC crisis (hazard ratio [HR]=1.14; p=0.813), but there was a significant effect of baseline ammonia ≥ 1.0 ULN (HR=4.62; p=0.0011). Conclusions The findings in this UCD population suggest that glutamine is a weaker predictor of HACs than ammonia and that the utility of the predictive value of glutamine will need to take into account concurrent ammonia levels. PMID:26586473

l-glutamine and l-alanine supplementation increase glutamine-glutathione axis and muscle HSP-27 in rats trained using a progressive high-intensity resistance exercise.

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Leite, Jaqueline Santos Moreira; Raizel, Raquel; Hypólito, Thaís Menezes; Rosa, Thiago Dos Santos; Cruzat, Vinicius Fernandes; Tirapegui, Julio

2016-08-01

In this study we investigated the chronic effects of oral l-glutamine and l-alanine supplementation, either in their free or dipeptide form, on glutamine-glutathione (GLN-GSH) axis and cytoprotection mediated by HSP-27 in rats submitted to resistance exercise (RE). Forty Wistar rats were distributed into 5 groups: sedentary; trained (CTRL); and trained supplemented with l-alanyl-l-glutamine, l-glutamine and l-alanine in their free form (GLN+ALA), or free l-alanine (ALA). All trained animals were submitted to a 6-week ladder-climbing protocol. Supplementations were offered in a 4% drinking water solution for 21 days prior to euthanasia. Plasma glutamine, creatine kinase (CK), myoglobin (MYO), and erythrocyte concentration of reduced GSH and glutathione disulfide (GSSG) were measured. In tibialis anterior skeletal muscle, GLN-GSH axis, thiobarbituric acid reactive substances (TBARS), and the expression of heat shock factor 1 (HSF-1), 27-kDa heat shock protein (HSP-27), and glutamine synthetase were determined. In CRTL animals, high-intensity RE reduced muscle glutamine levels and increased GSSG/GSH rate and TBARS, as well as augmented plasma CK and MYO levels. Conversely, l-glutamine-supplemented animals showed an increase in plasma and muscle levels of glutamine, with a reduction in GSSG/GSH rate, TBARS, and CK. Free l-alanine administration increased plasma glutamine concentration and lowered muscle TBARS. HSF-1 and HSP-27 were high in all supplemented groups when compared with CTRL (p alanine, in both a free or dipeptide form, improve the GLN-GSH axis and promote cytoprotective effects in rats submitted to high-intensity RE training.

Glutamine deprivation induces interleukin-8 expression in ataxia telangiectasia fibroblasts.

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Kim, Min-Hyun; Kim, Aryung; Yu, Ji Hoon; Lim, Joo Weon; Kim, Hyeyoung

2014-05-01

To investigate whether glutamine deprivation induces expression of inflammatory cytokine interleukin-8 (IL-8) by determining NF-κB activity and levels of oxidative indices (ROS, reactive oxygen species; hydrogen peroxide; GSH, glutathione) in fibroblasts isolated from patients with ataxia telangiectasia (A-T). We used A-T fibroblasts stably transfected with empty vector (Mock) or with human full-length ataxia telangiectasia mutated (ATM) cDNA (YZ5) and mouse embryonic fibroblasts (MEFs) transiently transfected with ATM small interfering RNA (siRNA) or with non-specific control siRNA. The cells were cultured with or without glutamine or GSH. ROS levels were determined using a fluorescence reader and confocal microscopy. IL-8 or murine IL-8 homolog, keratinocyte chemoattractant (KC), and hydrogen peroxide levels in the medium were determined by enzyme-linked immunosorbent assay and colorimetric assay. GSH level was assessed by enzymatic assay, while IL-8 (KC) mRNA level was measured by reverse transcription-polymerase chain reaction (RT-PCR) and/or quantitative real-time PCR. NF-κB DNA-binding activity was determined by electrophoretic mobility shift assay. Catalase activity and ATM protein levels were determined by O2 generation and Western blotting. While glutamine deprivation induced IL-8 expression and increased NF-κB DNA-binding activity in Mock cells, both processes were decreased by treatment of cells with glutamine or GSH or both glutamine and GSH. Glutamine deprivation had no effect on IL-8 expression or NF-κB DNA-binding activity in YZ5 cells. Glutamine-deprived Mock cells had higher oxidative stress indices (increases in ROS and hydrogen peroxide, reduction in GSH) than glutamine-deprived YZ5 cells. In Mock cells, glutamine deprivation-induced oxidative stress indices were suppressed by treatment with glutamine or GSH or both glutamine and GSH. GSH levels and catalase activity were lower in Mock cells than YZ5 cells. MEFs transfected with ATM siRNA and

Glutamine and glutamate as vital metabolites

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Newsholme P.

2003-01-01

Full Text Available Glucose is widely accepted as the primary nutrient for the maintenance and promotion of cell function. This metabolite leads to production of ATP, NADPH and precursors for the synthesis of macromolecules such as nucleic acids and phospholipids. We propose that, in addition to glucose, the 5-carbon amino acids glutamine and glutamate should be considered to be equally important for maintenance and promotion of cell function. The functions of glutamine/glutamate are many, i.e., they are substrates for protein synthesis, anabolic precursors for muscle growth, they regulate acid-base balance in the kidney, they are substrates for ureagenesis in the liver and for hepatic and renal gluconeogenesis, they act as an oxidative fuel for the intestine and cells of the immune system, provide inter-organ nitrogen transport, and act as precursors of neurotransmitter synthesis, of nucleotide and nucleic acid synthesis and of glutathione production. Many of these functions are interrelated with glucose metabolism. The specialized aspects of glutamine/glutamate metabolism of different glutamine-utilizing cells are discussed in the context of glucose requirements and cell function.

Prolonged continuous intravenous infusion of the dipeptide L-alanine- L-glutamine significantly increases plasma glutamine and alanine without elevating brain glutamate in patients with severe traumatic brain injury.

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Nägeli, Mirjam; Fasshauer, Mario; Sommerfeld, Jutta; Fendel, Angela; Brandi, Giovanna; Stover, John F

2014-07-02

Low plasma glutamine levels are associated with worse clinical outcome. Intravenous glutamine infusion dose- dependently increases plasma glutamine levels, thereby correcting hypoglutaminemia. Glutamine may be transformed to glutamate which might limit its application at a higher dose in patients with severe traumatic brain injury (TBI). To date, the optimal glutamine dose required to normalize plasma glutamine levels without increasing plasma and cerebral glutamate has not yet been defined. Changes in plasma and cerebral glutamine, alanine, and glutamate as well as indirect signs of metabolic impairment reflected by increased intracranial pressure (ICP), lactate, lactate-to-pyruvate ratio, electroencephalogram (EEG) activity were determined before, during, and after continuous intravenous infusion of 0.75 g L-alanine-L-glutamine which was given either for 24 hours (group 1, n = 6) or 5 days (group 2, n = 6) in addition to regular enteral nutrition. Lab values including nitrogen balance, urea and ammonia were determined daily. Continuous L-alanine-L-glutamine infusion significantly increased plasma and cerebral glutamine as well as alanine levels, being mostly sustained during the 5 day infusion phase (plasma glutamine: from 295 ± 62 to 500 ± 145 μmol/ l; brain glutamine: from 183 ± 188 to 549 ± 120 μmol/ l; plasma alanine: from 327 ± 91 to 622 ± 182 μmol/ l; brain alanine: from 48 ± 55 to 89 ± 129 μmol/ l; p alanine-L-glutamine infusion (0.75 g/ kg/ d up to 5 days) increased plasma and brain glutamine and alanine levels. This was not associated with elevated glutamate or signs of potential glutamate-mediated cerebral injury. The increased nitrogen load should be considered in patients with renal and hepatic dysfunction. Clinicaltrials.gov NCT02130674. Registered 5 April 2014.

The importance of cytosolic glutamine synthetase in nitrogen assimilation and recycling

Energy Technology Data Exchange (ETDEWEB)

Bernard, S.M.; Habash, D.Z.

2009-07-02

Glutamine synthetase assimilates ammonium into amino acids, thus it is a key enzyme for nitrogen metabolism. The cytosolic isoenzymes of glutamine synthetase assimilate ammonium derived from primary nitrogen uptake and from various internal nitrogen recycling pathways. In this way, cytosolic glutamine synthetase is crucial for the remobilization of protein-derived nitrogen. Cytosolic glutamine synthetase is encoded by a small family of genes that are well conserved across plant species. Members of the cytosolic glutamine synthetase gene family are regulated in response to plant nitrogen status, as well as to environmental cues, such as nitrogen availability and biotic/abiotic stresses. The complex regulation of cytosolic glutamine synthetase at the transcriptional to post-translational levels is key to the establishment of a specific physiological role for each isoenzyme. The diverse physiological roles of cytosolic glutamine synthetase isoenzymes are important in relation to current agricultural and ecological issues.

Pyruvate carboxylase is required for glutamine-independent growth of tumor cells

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Cheng, Tzuling; Sudderth, Jessica; Yang, Chendong; Mullen, Andrew R.; Jin, Eunsook S.; Matés, José M.; DeBerardinis, Ralph J.

2011-01-01

Tumor cells require a constant supply of macromolecular precursors, and interrupting this supply has been proposed as a therapeutic strategy in cancer. Precursors for lipids, nucleic acids, and proteins are generated in the tricarboxylic acid (TCA) cycle and removed from the mitochondria to participate in biosynthetic reactions. Refilling the pool of precursor molecules (anaplerosis) is therefore crucial to maintain cell growth. Many tumor cells use glutamine to feed anaplerosis. Here we studied how “glutamine-addicted” cells react to interruptions of glutamine metabolism. Silencing of glutaminase (GLS), which catalyzes the first step in glutamine-dependent anaplerosis, suppressed but did not eliminate the growth of glioblastoma cells in culture and in vivo. Profiling metabolic fluxes in GLS-suppressed cells revealed induction of a compensatory anaplerotic mechanism catalyzed by pyruvate carboxylase (PC), allowing the cells to use glucose-derived pyruvate rather than glutamine for anaplerosis. Although PC was dispensable when glutamine was available, forcing cells to adapt to low-glutamine conditions rendered them absolutely dependent on PC for growth. Furthermore, in other cell lines, measuring PC activity in nutrient-replete conditions predicted dependence on specific anaplerotic enzymes. Cells with high PC activity were resistant to GLS silencing and did not require glutamine for survival or growth, but displayed suppressed growth when PC was silenced. Thus, PC-mediated, glucose-dependent anaplerosis allows cells to achieve glutamine independence. Induction of PC during chronic suppression of glutamine metabolism may prove to be a mechanism of resistance to therapies targeting glutaminolysis. PMID:21555572

Assay of glutamine phosphoribosylpyrophosphate amidotransferase using [1-14C]phosphoribosylpyrophosphate

International Nuclear Information System (INIS)

Ross, G.R.; Idriss, S.D.; Willis, R.C.; Seegmiller, J.E.

1983-01-01

Glutamine phosphoribosylpyrophosphate amidotransferase (EC 2.4.2.14) catalyzes the transfer of the amide group of glutamine to 5-phospho-α-D-ribose-1-pyrophosphate. It is the first enzyme committed to the synthesis of purines by the de novo pathway. Previous assays of enzyme activity have either measured the phosphoribosylpyrophosphate-dependent disappearance of radioactive glutamine or have linked this reaction to subsequent steps in the purine pathway. A new assay for activity of the enzyme by directly measuring the synthesis of the product of the reaction, 5-β-phosphoribosyl-1-amine, using [1- 14 C]phosphoribosylpyrophosphate as substrate is described. Substrate and product are separated by thin-layer chromatography and identified by autoradiography. Glutamine or ammonia may be used as substrates; the apparent K/sub m/ values of the human lymphoblast enzyme are 0.46 mM for glutamine and 0.71 mM for ammonia. GMP is a considerably more potent inhibitor of the human lymphoblast enzyme than is AMP; 6-diazo-5-oxo-L-norleucine inhibits only glutamine-dependent activity and has no effect on ammonia-dependent activity

Changes in Activities of Glutamine Synthetase during Grain Filling and Their Relation to Rice Quality

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Zheng-xun JIN

2007-09-01

Full Text Available Four japonica rice varieties differed in cooking and eating qualities were used in a pot experiment to study the relationship between the activities of glutamine synthetase during grain filling and rice quality. The activities of glutamine synthetase gradually increased and then declined as a single peak curve in the course of grain filling. The 15th day after heading was a turning point, before which the enzymatic activities in the inferior rice varieties with high protein content were higher than those in the superior rice varietie with low protein content, and after which it was converse. The activity of glutamine synthetase in grain was correlated with the taste meter value, peak viscosity and breakdown negatively at the early stage of grain filling whereas positively at the middle and late stages. Moreover, it was correlated with the protein content of rice grain and setback positively at the early stage and negatively at the middle and late stages. The correlation degree varied with the course of grain filling. From 15 days to 20 days after heading was a critical stage, in which the direction of correlation between the activity of glutamine synthetase and taste meter value and RVA properties of rice changed.

Simultaneous monitoring of oxidation, deamidation, isomerization, and glycosylation of monoclonal antibodies by liquid chromatography-mass spectrometry method with ultrafast tryptic digestion.

Science.gov (United States)

Wang, Yi; Li, Xiaojuan; Liu, Yan-Hui; Richardson, Daisy; Li, Huijuan; Shameem, Mohammed; Yang, Xiaoyu

Monoclonal antibodies are subjected to a wide variety of post-translational modifications (PTMs) that cause structural heterogeneity. Characterization and control of these modifications or quality attributes are critical to ensure antibody quality and to define any potential effects on the ultimate safety and potency of antibody therapeutics. The biopharmaceutical industry currently uses numerous tools to analyze these quality attributes individually, which requires substantial time and resources. Here, we report a simple and ultrafast bottom-up liquid chromatography-mass spectrometry (uLC-MS) method with 5 min tryptic digestion to simultaneously analyze multiple modifications, including oxidation, deamidation, isomerization, glycation, glycosylation, and N-terminal pyro-glutamate formation, which can occur during antibody production in mammalian cell culture, during purification and/or on storage. Compared to commonly used preparation procedures, this uLC-MS method eliminates assay artifacts of falsely-increased Met oxidation, Asp isomerization, and Asn deamidation, a problem associated with long digestion times in conventional LC-MS methods. This simple, low artifact multi-attribute uLC-MS method can be used to quickly and accurately analyze samples at any stage of antibody drug development, in particular for clone and media selection during cell culture development.

Ion exclusion chromatography for the purification of L-glutamine; Ion haijo chromatography ni yoru L-glutamine no seiseiho no kenkyu

Energy Technology Data Exchange (ETDEWEB)

Ito, H.; Nishi, A.; Naruse, M. [Ajinomoto Co. Inc., Kawasaki (Japan)

1998-09-05

Ion exclusion chromatography for the purification of L-glutamine is studied. L-glutamine is usually produced by fermentation and used in pharmaceuticals. By using a model solution of L-glutamine and L-glutamic acid, the optimum cation exchange resin is examined. As a result of the experiments, it is found that a cation exchange resin which has smaller crosslinkage and smaller diameter is better. Ammonium sulfate, L-glutamic acid and pyrrolidonecarboxylic acid, which are usually contained in fermentation broth as impurities, are effectively separated by this method. Moreover, the experimental data of the chromatography is expressed fairly well by the differential equations which express the mass transfer in the fixed bed. 8 refs., 5 figs., 2 tabs.

Effect of. gamma. radiation in relatively low dose on the activity of glutaminase in subcellular fraction of brain and liver cells. [Rats

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Tkach, V M

1973-01-01

The effect of ..gamma..-irradiation at a dose of 40 rads was studied on the exchange of glutamine in rats. It has been shown that the irradiation leads to a significant lowering of the activity of glutaminamidohydrolase (I) in brain mitochondria and in the liver after 1, 3, 7, 15, and 30 days post exposure. In the fractions containing nuclei, fraction of myofibrillae and connective tissue, a slow down of the deamidation of glutamine also takes place, and only after 7 days the ammonium separation from glutamine increases and returns to normal. At the 15 and 30 days a second wave of the lower rate of the activity of I takes place. The type of the changes of I is the same in both organs, but in the liver it is expressed to a lesser degree. (JPRS)

Analysis of the post-translational modifications of the individual amino acids in lens proteins which were induced by aging and irradiation

International Nuclear Information System (INIS)

Fujii, Noriko; Kim, Ingu; Saito, Takeshi; Takata, Takumi

2017-01-01

The eye lens is a transparent organ that functions to focus light and images on the retina. The transparency and high refraction of the lens are maintained by the function of α-, β- and γ-crystallins. These long-lived proteins are subject to various post-translational modifications, such as oxidation, deamidation, truncation and isomerization, which occur gradually during the aging process. Such modifications, which are generated by UV light and oxidative stress, decrease crystallin solubility and lens transparency, and ultimately lead to the development of age-related cataracts. Here, we irradiated young rat lenses with γ-rays (5-500 Gy) and extracted the water-soluble (WS) and insoluble (WI) protein fractions. The WS and WI lens proteins were digested with trypsin, and the resulting peptides were analyzed by one-shot LC-MS/MS to determine the specific sites of oxidation of methionine and tryptophan, deamidation of asparagine and glutamine, and isomerization of aspartyl in rat α- and β-crystallins in the WS and WI fractions. Oxidation and deamidation occurred in several crystallins after irradiation at more than, respectively, 50 Gy and 5 Gy; however, isomerization did not occur in any crystallin even after exposure to 500 Gy of irradiation. The number of oxidation and deamidation sites was much higher in the WI than in the WS fraction. Furthermore, the oxidation and deamidation sites in rat crystallins resemble those reported in crystallins from human age-related cataracts. Thus, this study on post-translational modifications of crystallins induced by ionizing irradiation may provide useful information relevant to the formation of human age-related cataracts. (author)

ATP-dependent and NAD-dependent modification of glutamine synthetase from Rhodospirillum rubrum in vitro

International Nuclear Information System (INIS)

Woehle, D.L.; Lueddecke, B.A.; Ludden, P.W.

1990-01-01

Glutamine synthetase from the photosynthetic bacterium Rhodospirillum rubrum is the target of both ATP- and NAD-dependent modification. Incubation of R. rubrum cell supernatant with [α- 32 P]NAD results in the labeling of glutamine synthetase and two other unidentified proteins. Dinitrogenase reductase ADP-ribosyltransferase does not appear to be responsible for the modification of glutamine synthetase or the unidentified proteins. The [α- 32 P]ATP- and [α- 32 P] NAD-dependent modifications of R. rubrum glutamine synthetase appear to be exclusive and the two forms of modified glutamine synthetase are separable on two-dimensional gels. Loss of enzymatic activity by glutamine synthetase did not correlate with [α- 32 P]NAD labeling. This is in contrast to inactivation by nonphysiological ADP-ribosylation of other glutamine synthetases by an NAD:arginine ADP-ribosyltransferase from turkey erythrocytes. A 32 P-labeled protein spot comigrates with the NAD-treated glutamine synthetase spot when glutamine synthetase purified from H 3 32 PO 4 -grown cells is analyzed on two-dimensional gels. The adenylylation site of R. rubrum glutamine synthetase has been determined to be Leu-(Asp)-Tyr-Leu-Pro-Pro-Glu-Glu-Leu-Met; the tyrosine residue is the site of modification

Antibodies against deamidated gliadin peptides identify adult coeliac disease patients negative for antibodies against endomysium and tissue transglutaminase.

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Dahle, C; Hagman, A; Ignatova, S; Ström, M

2010-07-01

This study was done to evaluate the diagnostic utility of antibodies against deamidated gliadin peptides compared to traditional markers for coeliac disease. To evaluate diagnostic utility of antibodies against deamidated gliadin peptide (DGP). Sera from 176 adults, referred for endoscopy without previous analysis of antibodies against tissue transglutaminase (tTG) or endomysium (EmA), were retrospectively analysed by ELISAs detecting IgA/IgG antibodies against DGP or a mixture of DGP and tTG, and compared with IgA-tTG and EmA. Seventy-nine individuals were diagnosed with coeliac disease. Receiver operating characteristic analyses verified the manufacturers' cut-off limits except for IgA/IgG-DGP/tTG. In sera without IgA deficiency, the sensitivity was higher for IgA/IgG-DGP (0.85-0.87) compared with IgA-tTg (0.76) and EmA (0.61). All tests showed high specificity (0.95-1.00). Eighteen coeliac disease-sera were negative regarding IgA-tTG, nine of which were positive for IgA/IgG-DGP. Sera from coeliac disease-patients >70 years were more often negative for IgA-tTG (50%) and IgA/IgG-DGP (36%) than younger patients (15% and 8% respectively) (P adult coeliac disease patients negative for antibodies against endomysium and tissue transglutaminase. Serology is often negative in elderly patients with coeliac disease; a small bowel biopsy should therefore be performed generously before coeliac disease is excluded.

No allelic variation in genes with high gliadin homology in patients with celiac disease and type 1 diabetes

DEFF Research Database (Denmark)

Nielsen, Christian; Hansen, Dorte; Husby, Steffen

2004-01-01

recognize gluten-derived peptides in which specific glutamine residues are deamidated to glutamic acid by tissue transglutaminase. Recently, intestinally expressed human genes with high homology to DQ2-gliadin celiac T-cell epitopes have been identified. Single or double point mutations which would increase...... the celiac T-cell epitope homology, and mutation in these genes, leading to the expression of glutamic acid at particular positions, could hypothetically be involved in the initiation of CD in HLA-DQ2-positive children. Six gene regions with high celiac T-cell epitope homology were investigated for single......-nucleotide polymorphisms using direct sequencing of DNA from 20 CD patients, 27 type 1 diabetes mellitus (T1DM) patients with associated CD, 24 patients with T1DM without CD and 110 healthy controls, all of Caucasian origin. No variants in any of these genes in any of the investigated groups were found. We conclude...

Effects of glutamine, taurine and their association on inflammatory pathway markers in macrophages.

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Sartori, Talita; Galvão Dos Santos, Guilherme; Nogueira-Pedro, Amanda; Makiyama, Edson; Rogero, Marcelo Macedo; Borelli, Primavera; Fock, Ricardo Ambrósio

2018-06-01

The immune system is essential for the control and elimination of infections, and macrophages are cells that act as important players in orchestrating the various parts of the inflammatory/immune response. Amino acids play important role in mediating functionality of the inflammatory response, especially mediating macrophages functions and cytokines production. We investigated the influence of glutamine, taurine and their association on the modulation of inflammatory pathway markers in macrophages. The RAW 264.7 macrophage cell line was cultivated in the presence of glutamine and taurine and proliferation rates, cell viability, cell cycle phases, IL-1α, IL-6, IL-10 and TNF-α as well as H 2 O 2 production and the expression of the transcription factor, NFκB, and its inhibitor, IκBα, were evaluated. Our results showed an increase in viable cells and increased proliferation rates of cells treated with glutamine concentrations over 2 mM, as well as cells treated with both glutamine and taurine. The cell cycle showed a higher percentage of cells in the phases S, G2 and M when they were treated with 2 or 10 mM glutamine, or with glutamine and taurine in cells stimulated with lipopolysaccharide. The pNFκB/NFκB showed reduced ratio expression when cells were treated with 10 mM of glutamine or with glutamine in association with taurine. These conditions also resulted in reduced TNF-α, IL-1α and H 2 O 2 production, and higher production of IL-10. These findings demonstrate that glutamine and taurine are able to modulate macrophages inflammatory pathways, and that taurine can potentiate the effects of glutamine, illustrating their immunomodulatory properties.

Effect of L-glutamine levels in piglets diets challenged with Escherichia coli lipopolysacharides

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Arturo Pardo L.

2014-09-01

Full Text Available Objective. To evaluate the effect of different levels of L-glutamine on weaned and immunologically challenged piglets with Escherichia coli lipopolysaccharides (LPS on performance parameters, serum cortisol and defense cells. Materials and methods. Four levels of L –glutamine were evaluated (0, 1.0, 1.5, 2.0% as well as the addition, or no addition, of LPS (0.3μg. 96 piglets were used (48 castrated males and 48 females of Agroceres x PenArlan lineage, with an initial age of 21 days and 6.06±0.852 kg live weight. An experimental design was used on randomized blocks in a factorial setting 4 x 2 (levels of L- glutamine with or without challenge. Results. Cubic effect was shown for daily weight gain of unchallenged animals, and was better with the addition of 0.41% L- glutamine. Feed conversion improved with increased levels of L -glutamine for challenged animals. In the evaluation of defense cells, there was interaction of leukocytes with the levels of L- glutamine and the immune challenge. Eosinophils and lymphocytes showed a quadratic effect for the levels of L –glutamine, with a maximum value of 1.30% and 0.5%, respectively. Conclusions. L -glutamine supplementation of up to 2% in the diet improves feed conversion and favors the immune serum of weaned piglets challenged with LPS of E. coli.

Effects of hyperthyroidism and hypothyroidism on glutamine metabolism by skeletal muscle of the rat.

Science.gov (United States)

Parry-Billings, M; Dimitriadis, G D; Leighton, B; Bond, J; Bevan, S J; Opara, E; Newsholme, E A

1990-01-01

1. The effects of hyperthyroidism and hypothyroidism on the concentrations of glutamine and other amino acids in the muscle and plasma and on the rates of glutamine and alanine release from incubated isolated stripped soleus muscle of the rat were investigated. 2. Hyperthyroidism decreased the concentration of glutamine in soleus muscle but was without effect on that in the gastrocnemius muscle or in the plasma. Hyperthyroidism also increased markedly the rate of release of glutamine from the incubated soleus muscle. 3. Hypothyroidism decreased the concentrations of glutamine in the gastrocnemius muscle and plasma but was without effect on that in soleus muscle. Hypothyroidism also decreased markedly the rate of glutamine release from the incubated soleus muscle. 4. Thyroid status was found to have marked effects on the rate of glutamine release by skeletal muscle per se, and may be important in the control of this process in both physiological and pathological conditions. PMID:2268261

Insecticidal activity of glufosinate through glutamine depletion in a caterpillar.

Science.gov (United States)

Kutlesa, N J; Caveney, S

2001-01-01

The herbicide glufosinate-ammonium (GLA) is a competitive inhibitor of glutamine synthetase (GS), an enzyme converting glutamate to glutamine in both plants and animals. Because GS is essential for ammonia detoxification in plants, GLA treatment disrupts photorespiration by causing a build-up of ammonia and a loss of glutamine in plant tissues. This study reports that GLA applied to leaf surfaces is also toxic to 5th-instar caterpillars of the skipper butterfly Calpodes ethlius (LD50 = 400 mg kg-1). After ingesting GLA, caterpillars stopped feeding and became dehydrated through a loss of rectal function. Caterpillars showed symptoms of neurotoxicity, such as proleg tremors, body convulsions and complete paralysis before death. Incubation of several tissues isolated from normal feeding-stage caterpillars with the GS substrates glutamate and ammonium showed that GLA inhibited GS activity in vitro. Within 24 h of ingesting GLA, caterpillars had a greatly reduced glutamine content and the ammonium ion levels had more than doubled. Injection of ammonium chloride into non-GLA-treated caterpillars had no deleterious effect, suggesting that glutamine depletion, and not a rise in body ammonium, was the primary cause of GLA toxicity following GS inhibition. This was supported by the observation that the onset of the symptoms of GLA poisoning could be postponed by giving GLA-fed caterpillars several subsequent daily injections of glutamine. The effective GLA dose fed to 5th-instar caterpillars in this study was comparable to the amount that might realistically by acquired from feeding on GLA-treated crops.

Regulation of the glutamine transporter SN1 by extracellular pH and intracellular sodium ions

International Nuclear Information System (INIS)

Broeer, A.; Broeer, S.; Setiawan, I.; Lang, F.

2001-01-01

Full text: SN1 has recently been identified as one of the major glutamine transporters in hepatocytes and brain astrocytes. It appears to be the molecular correlate of the system N amino acid transporter. Two different transport mechanisms have been proposed for this transporter. Either an electroneutral mechanism, in which glutamine uptake is coupled to an exchange of 1Na + and 1H + , or an electrogenic mechanism coupled to the exchange of 2Na + against 1H + . This study was performed to solve the discrepancies and to investigate the reversibility of the transporter. When expressed in Xenopus laevis oocytes glutamine uptake activity increased strongly with increasing pH. In agreement with the pH-dependence we found that uptake of glutamine was accompanied by an alkalization of the cytosol, indicating that SN1 mediates Glutamine/H + -Antiport. Uptake of glutamine into oocytes was Na + -dependent. Analysis of the Na + -dependence of glutamine transport and Flux studies using 22 Na + indicated that two or more sodium ions were cotransported together with glutamine. However, at the same time intracellular Na + was exchanged against extracellular Na + . Taken together with the results of the pH-dependence it is proposed that SN1 mediates a Na + /Na + -exchange and a Na + /H + -exchange, both being coupled to the transport of glutamine. In agreement with this mechanism we found that acidic pH caused a reversal of the transporter. To investigate the source of the glutamine-induced inward currents, we compared inward currents generated by the 1Na + /glutamine cotransporter ATA1 with those generated by SN1. Currents induced by glutamine uptake in SN1 expressing oocytes were only a fraction of the currents induced by glutamine in ATA1 expressing oocytes, indicating that they were not generated by a stoichiometric uptake of ions. It is concluded that SN1 is tightly regulated by pH and intracellular Na + -ions and is capable of mediating glutamine uptake and release

Effect of intermittent glutamine supplementation on skeletal muscle is not long-lasting in very old rats.

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Meynial-Denis, D; Beaufrère, A-M; Mignon, M; Patureau Mirand, P

2013-01-01

Muscle is the major site for glutamine synthesis via glutamine synthetase (GS). This enzyme is increased 1.5-2 fold in 25-27-mo rats and may be a consequence of aging-induced stress. This stimulation is similar to the induction observed following a catabolic state such as glucocorticoid treatment (6 to 24 months). Although oral glutamine supply regulates the plasma glutamine level, nothing is known if this supplementation is interrupted before the experiment. Adult (8-mo) and very old (27-mo) female rats were exposed to intermittent glutamine supplementation for 50 % of their age lifetime. Treated rats received glutamine added to their drinking water and control rats water alone but the effect of glutamine supplementation was only studied 15 days after the last supplementation. Glutamine pretreatment discontinued 15 days before the experiment increased plasma glutamine to ~ 0.6 mM, a normal value in very old rats. However, it failed to decrease the up-regulated GS activity in skeletal muscle from very old rats. Our results suggest that long-term treatment with glutamine started before advanced age but discontinued 15 days before rat sacrifice is effective in increasing plasma glutamine to recover basal adult value and in maintaining plasma glutamine in very old rats, but has no long-lasting effect on the GS activity of skeletal muscle with advanced age.

Glutamine granule-supplemented enteral nutrition maintains immunological function in severely burned patients.

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Peng, Xi; Yan, Hong; You, Zhongyi; Wang, Pei; Wang, Shiliang

2006-08-01

Glutamine is an important energy source for immune cells. It is a necessary nutrient for cell proliferation, and serves as specific fuel for lymphocytes, macrophages, and enterocytes when it is present in appropriate concentrations. The purpose of this clinical study was to observe the effects of enteral nutrition supplemented with glutamine granules on immunologic function in severely burned patients. Forty-eight severely burned patients (total burn surface area 30-75%, full thickness burn area 20-58%) who met the requirements of the protocol joined this double-blind randomized controlled clinical trail. Patients were randomly divided into two groups: burn control group (B group, 23 patients) and glutamine treated group (Gln group, 25 patients). There was isonitrogenous and isocaloric intake in both groups, Gln and B group patents were given glutamine granules or placebo (glycine) at 0.5 g/kgd for 14 days with oral feeding or tube feeding, respectively. The plasma level of glutamine and several indices of immunologic function including lymphocyte transformation ratio, neutrophil phagocytosis index (NPI), CD4/CD8 ratio, the content of immunoglobulin, complement C3, C4 and IL-2 levels were determined. Moreover, wound healing rate of burn area was observed and then hospital stay was recorded. The results showed significantly reduced plasma glutamine and damaged immunological function after severe burn Indices of cellular immunity function were remarkably decreased from normal controls. After taking glutamine granules for 14 days, plasma glutamine concentration was significantly higher in Gln group than that in B group (607.86+/-147.25 micromol/L versus 447.63+/-132.38 micromol/L, P0.05). In addition, wound healing was better and hospital stay days were reduced in Gln group (46.59+/-12.98 days versus 55.68+/-17.36 days, Pburn; supplemented glutamine granules with oral feeding or tube feeding abate the degree of immunosuppression, improve immunological function

The role of glutamine transport in metabolism in the brain cortical tissue slice

International Nuclear Information System (INIS)

Hare, N.; Bubb, W.A.; Rae, C.; Broeer, S.

2001-01-01

The widely accepted 'glutamate/glutamine cycle' holds that glutamate released as a neurotransmitter in the brain is taken up by surrounding astrocytes, converted to neuro-inactive glutamine and transported back to neurons for reconversion to glutamate. Little, however, is known about the role of glutamine transport in this process. The situation is complicated by the fact that glutamine is transported by a variety of general amino-acid transporters of low specificity. The role of these transporters in flux of glutamine through the glutamate/glutamine cycle was investigated by 13 C NMR monitoring of the flux of C from [3- 13 C]L-lactate in guinea pig cortical tissue slices in the presence of competitive inhibitors of the A-type(α-(methylamino)isobutyrate; MeAIB) and N-type (histidine) transporters. The presence of each inhibitor (10 mM) produced no significant decrease in total metabolite pool size but resulted in a significant decrease in flux of [ 13 C] into the neurotransmitters glutamate and GABA and also into glutamine and alanine. The factional enrichment of glutamate and GABA was also significantly lower. By contrast there was no effect on the amount of [ 13 C] incorporated into aspartate isotopomers which may represent a predominantly astrocyte-labelled pool. These results are consistent with involvement of glutamine transporters in the recycling of synaptic glutamate by demonstrating partial blockage of incorporation of [ 13 C] label into neuronal metabolites

Glutamine prevents oxidative stress in a model of portal hypertension.

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Zabot, Gilmara Pandolfo; Carvalhal, Gustavo Franco; Marroni, Norma Possa; Licks, Francielli; Hartmann, Renata Minuzzo; da Silva, Vinícius Duval; Fillmann, Henrique Sarubbi

2017-07-07

To evaluate the protective effects of glutamine in a model of portal hypertension (PH) induced by partial portal vein ligation (PPVL). Male Wistar rats were housed in a controlled environment and were allowed access to food and water ad libitum . Twenty-four male Wistar rats were divided into four experimental groups: (1) control group (SO) - rats underwent exploratory laparotomy; (2) control + glutamine group (SO + G) - rats were subjected to laparotomy and were treated intraperitoneally with glutamine; (3) portal hypertension group (PPVL) - rats were subjected to PPVL; and (4) PPVL + glutamine group (PPVL + G) - rats were treated intraperitoneally with glutamine for seven days. Local injuries were determined by evaluating intestinal segments for oxidative stress using lipid peroxidation and the activities of glutathione peroxidase (GPx), endothelial nitric oxide synthase (eNOS) and inducible nitric oxide synthase (iNOS) after PPVL. Lipid peroxidation of the membrane was increased in the animals subjected to PH ( P 0.05). The activity of the antioxidant enzyme GTx was decreased in the gut of animals subjected to PH compared with that in the control group of animals not subjected to PH ( P 0.05). At least 10 random, non-overlapping images of each histological slide with 200 × magnification (44 pixel = 1 μm) were captured. The sum means of all areas, of each group were calculated. The mean areas of eNOS staining for both of the control groups were similar. The PPVL group showed the largest area of staining for eNOS. The PPVL + G group had the second highest amount of staining, but the mean value was much lower than that of the PPVL group ( P < 0.01). For iNOS, the control (SO) and control + G (SO + G) groups showed similar areas of staining. The PPVL group contained the largest area of iNOS staining, followed by the PPVL + G group; however, this area was significantly smaller than that of the group that underwent PH without glutamine ( P < 0.01). Treatment with

Early Administration of Glutamine Protects Cardiomyocytes from Post-Cardiac Arrest Acidosis

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Yan-Ren Lin

2016-01-01

Full Text Available Postcardiac arrest acidosis can decrease survival. Effective medications without adverse side effects are still not well characterized. We aimed to analyze whether early administration of glutamine could improve survival and protect cardiomyocytes from postcardiac arrest acidosis using animal and cell models. Forty Wistar rats with postcardiac arrest acidosis (blood pH < 7.2 were included. They were divided into study (500 mg/kg L-alanyl-L-glutamine, n=20 and control (normal saline, n=20 groups. Each of the rats received resuscitation. The outcomes were compared between the two groups. In addition, cardiomyocytes derived from human induced pluripotent stem cells were exposed to HBSS with different pH levels (7.3 or 6.5 or to culture medium (control. Apoptosis-related markers and beating function were analyzed. We found that the duration of survival was significantly longer in the study group (p<0.05. In addition, in pH 6.5 or pH 7.3 HBSS buffer, the expression levels of cell stress (p53 and apoptosis (caspase-3, Bcl-xL markers were significantly lower in cardiomyocytes treated with 50 mM L-glutamine than those without L-glutamine (RT-PCR. L-glutamine also increased the beating function of cardiomyocytes, especially at the lower pH level (6.5. More importantly, glutamine decreased cardiomyocyte apoptosis and increased these cells’ beating function at a low pH level.

Importance of glutamine metabolism in leukemia cells by energy production through TCA cycle and by redox homeostasis.

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Goto, Mineaki; Miwa, Hiroshi; Shikami, Masato; Tsunekawa-Imai, Norikazu; Suganuma, Kazuto; Mizuno, Shohei; Takahashi, Miyuki; Mizutani, Motonori; Hanamura, Ichiro; Nitta, Masakazu

2014-07-01

Some cancer cells depend on glutamine despite of pronounced glycolysis. We examined the glutamine metabolism in leukemia cells, and found that HL-60 cells most depended on glutamine in the 4 acute myelogenous leukemia (AML) cell lines examined: growth of HL-60 cells was most suppressed by glutamine deprivation and by inhibition of glutaminolysis, which was rescued by tricarboxylic acid (TCA) cycle intermediate, oxaloacetic acid. Glutamine is also involved in antioxidant defense function by increasing glutathione. Glutamine deprivation suppressed the glutathione content and elevated reactive oxygen species most evidently in HL-60 cells. Glutamine metabolism might be a therapeutic target in some leukemia.

Effects of hyperthyroidism and hypothyroidism on glutamine metabolism by skeletal muscle of the rat.

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Parry-Billings, M; Dimitriadis, G D; Leighton, B; Bond, J; Bevan, S J; Opara, E; Newsholme, E A

1990-01-01

1. The effects of hyperthyroidism and hypothyroidism on the concentrations of glutamine and other amino acids in the muscle and plasma and on the rates of glutamine and alanine release from incubated isolated stripped soleus muscle of the rat were investigated. 2. Hyperthyroidism decreased the concentration of glutamine in soleus muscle but was without effect on that in the gastrocnemius muscle or in the plasma. Hyperthyroidism also increased markedly the rate of release of glutamine from the...

Glutamine Synthetase Deficiency in Murine Astrocytes Results in Neonatal Death

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He, Youji; Hakvoort, Theodorus B. M.; Vermeulen, Jacqueline L. M.; Labruyère, Wilhelmina T.; de Waart, D. Rudi; van der Hel, W. Saskia; Ruijter, Jan M.; Uylings, Harry B. M.; Lamers, Wouter H.

2010-01-01

Glutamine synthetase (GS) is a key enzyme in the "glutamine-glutamate cycle" between astrocytes and neurons, but its function in vivo was thus far tested only pharmacologically. Crossing GS(fl/lacZ) or GS(fl/f)l mice with hGFAP-Cre mice resulted in prenatal excision of the GS(fl) allele in

Effects of glutamine on performance and intestinal mucosa morphometry of broiler chickens vaccinated against coccidiosis

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Brenda Carla Luquetti

2016-08-01

Full Text Available ABSTRACT This study aimed to assess the effects of glutamine as feed additive on performance and intestinal mucosa morphometry of broiler chickens vaccinated against coccidiosis. A total of 400 day-old male chicks were randomly assigned to four treatments (NVNG – no vaccination, no glutamine supplementation; NVG – no vaccination, glutamine supplementation (10 g kg−1; VNG – vaccination, no glutamine supplementation; VG – vaccination, glutamine supplementation replicated four times with 25 birds per replicate. A commercial sprayed-on vaccine against coccidiosis containing Eimeria acervulina, E. maxima, E. mivati, and E. tenella was administered at the hatchery. Broiler performance was evaluated from 1-28 days, and morphometric parameters were analyzed at 14, 21, and 28 days of age. Body weight gain and feed intake were negatively affected by vaccination, but not by glutamine. Vaccination increased crypt depth in the duodenum and jejunum at 21 and 28 days. In conclusion, this study showed that glutamine was not able to increase weight gain of broiler chickens, irrespective of whether the animals were vaccinated or not against coccidiosis. Glutamine supplementation was able to improve feed conversion in vaccinated birds suggesting trophic effect on intestinal epithelium improving.

Clinical and protein metabolic efficacy of glutamine granules-supplemented enteral nutrition in severely burned patients.

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Peng, Xi; Yan, Hong; You, Zhongyi; Wang, Pei; Wang, Shiliang

2005-05-01

As an abundant amino acid in the human body, glutamine has many important metabolic roles that may protect or promote tissue integrity and enhance the immune system. A relative deficiency of glutamine in such patients could compromise recovery and result in prolonged illness and an increase in late mortality. The purpose of this clinical study is to observe the effects of enteral supplement with glutamine granules on protein metabolism in severely burned patients. Forty-eight severe burn patients (total burn surface area 30-75%, full thickness burn area 20-58%) who met the requirements of the protocol joined this double-blind randomized controlled clinical trial. Patients were randomly divided into two groups: burn control group (B group, 23 patients) and glutamine treated group (Gln group, 25 patients). There was isonitrogenous and isocaloric intake in both groups, glutamine and B group patents were supplemented with glutamine granules or placebo (glycine) at 0.5 g/kg per day for 14 days with oral feeding or tube feeding, respectively. The level of plasma glutamine, plasma protein content, urine nitrogen and urine 3-methylhistidine (3-MTH) excretion were determined, wound healing rate of the burned area and hospital stay were recorded. The results showed that there were significant reductions in plasma glutamine level and abnormal protein metabolism. After supplement with glutamine granules for 14 days, the plasma glutamine concentration was significantly higher than that in B group (607.86+/-147.25 micromol/L versus 447.63+/-132.38 micromol/L, P0.05). On the other hand, the amount of urine nitrogen and 3-MTH excreted in Gln group were significantly lower than that in B group. In addition, wound healing was faster and hospital stay days were shorter in Gln group than B group (46.59+/-12.98 days versus 55.68+/-17.36 days, P<0.05). These indicated that supplement glutamine granules with oral feeding or tube feeding could abate the degree of glutamine depletion

Supplementation of diets for weaned piglets withL-Valine and L-Glutamine+ L-Glutamic acid

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Naiara Diedrich Rodrigues

2015-10-01

Full Text Available The objective of this study was to evaluate the effects of supplementation of diets for weaned piglets with L-valine and L-glutamine + L-glutamic acid on performance, frequency of diarrhea, organ weight, digesta pH, intestinal morphology, and economic viability. Seventy-two piglets with a live weight of 7.53 ± 0.84 kg and 24 days of age were used. The animals were submitted to the following four treatments from 24 to 46 days of age: diet not supplemented with amino acids (control diet, CD; diet supplemented with glutamine + glutamic acid (GD; diet supplemented with glutamine + glutamic acid + valine (GVD, and diet supplemented with valine (VD. Two sequential phases (pre-initial I and pre-initial II with a duration of 12 and 11 days, respectively, were established. A completely randomized design, consisting of six repetitions and three pigs per experimental unit, was used. Nine days after weaning, at 32 days of age, a piglet per pen was slaughtered for the evaluation of organ weight, digesta pH and intestinal morphology. All animals received a single diet from days 47 to 65. No effects on performance were observed during the pre-initial phases I and II; however, when the whole study period was considered (24 to 65 days of age, piglets fed GVD consumed less feed and exhibited better feed conversion than animals of the VD group. With respect to morphometric parameters, GD provided a greater ileal crypt depth than CD and VD. There was an economic advantage of diets supplemented with L-valine and L-glutamine + L-glutamic acid, validating their use in diets for weaned piglets until 46 days of age.

[Imbalance of system of glutamin - glutamic acid in the placenta and amniotic fluid at placental insufficiency].

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Pogorelova, T N; Gunko, V O; Linde, V A

2014-01-01

Metabolism of glutamine and glutamic acid has been investigated in the placenta and amniotic fluid under conditions of placental insufficiency. The development of placental insufficiency is characterized by the increased content of glutamic acid and a decrease of glutamine in both placenta and amniotic fluid. These changes changes were accompanied by changes in the activity of enzymes involved in the metabolism of these amino acids. There was a decrease in glutamate dehydrogenase activity and an increase in glutaminase activity with the simultaneous decrease of glutamine synthetase activity. The compensatory decrease in the activity of glutamine keto acid aminotransferase did not prevent a decrease in the glutamine level. The impairments in the system glutamic acid-glutamine were more pronounced during the development of premature labor.

GLUTAMIN MEMPERCEPAT WAKTU PEMULIHAN JUMLAH SEL LIMFOSIT LIEN SETELAH AKTIVITAS FISIK MAKSIMAL PADA MENCIT (GLUTAMINE SHORTENS RECOVERY TIME OF LIEN LYMPHOCYTES AFTER EXCESSIVE PHYSICAL ACTIVITY IN MICE

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I Made Jawi

2007-06-01

Full Text Available The immunologic? system? of the body requires? suitable recovery time after? excessive physical? activity. The recovery? time of spleen lymphocytes after? excessive? physical activity? in one? investigation was? 3? days. The? aim? of this? research is to identify?the role of? glutamine? in shortening? the recovery time of? spleen? lymphocytes? after?excessive physical activity. The? study? was conducted? on? 70? adults? Balb/c mice which? were? divided? into? 7? groups, with? a randomized control? group post-test? only design. In this? study? an observation? was made on? spleen? lymphocytes? of control, after? excessive? physical activity(in the the? form of swimming? until? near? drowning with glutamine,? without glutamine ?and? after? the? recovery time of 1 and 2 days? of? each of? the 10 mice. Spleen? lymphocytes? were? counted in spleen preparation by mikroskop. The data obtained were tested? by? one way Anova. The findings? showed? that the number of spleen? lymphocytes significantly decrease after? excessive? physical activity?? in the?glutamine? and? non glutamine groups ( p < 0,05.The number of spleen? lymphocytes? was? not different as compered to control group or returned? to normal after recovery? time? of 1? day? in? the? glutamine group (p > 0,05 .?In the nonglutamine group the number of spleen lymphocytes was different from control group until 2 days (p<0,05 . From this finding it can be concluded that glutamine? shortens the recovery time of spleen lymphocytes? after? excessive? physical activity in mice.

Glutamine acts as a neuroprotectant against DNA damage, beta-amyloid and H2O2-induced stress.

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Jianmin Chen

Full Text Available Glutamine is the most abundant free amino acid in the human blood stream and is 'conditionally essential' to cells. Its intracellular levels are regulated both by the uptake of extracellular glutamine via specific transport systems and by its intracellular synthesis by glutamine synthetase (GS. Adding to the regulatory complexity, when extracellular glutamine is reduced GS protein levels rise. Unfortunately, this excess GS can be maladaptive. GS overexpression is neurotoxic especially if the cells are in a low-glutamine medium. Similarly, in low glutamine, the levels of multiple stress response proteins are reduced rendering cells hypersensitive to H(2O(2, zinc salts and DNA damage. These altered responses may have particular relevance to neurodegenerative diseases of aging. GS activity and glutamine levels are lower in the Alzheimer's disease (AD brain, and a fraction of AD hippocampal neurons have dramatically increased GS levels compared with control subjects. We validated the importance of these observations by showing that raising glutamine levels in the medium protects cultured neuronal cells against the amyloid peptide, Aβ. Further, a 10-day course of dietary glutamine supplementation reduced inflammation-induced neuronal cell cycle activation, tau phosphorylation and ATM-activation in two different mouse models of familial AD while raising the levels of two synaptic proteins, VAMP2 and synaptophysin. Together, our observations suggest that healthy neuronal cells require both intracellular and extracellular glutamine, and that the neuroprotective effects of glutamine supplementation may prove beneficial in the treatment of AD.

Pilot study with a glutamine-supplemented enteral formula in critically ill infants

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Barbosa Eliana

1999-01-01

Full Text Available Seriously ill infants often display protein-calorie malnutrition due to the metabolic demands of sepsis and respiratory failure. Glutamine has been classified as a conditionally essential amino acid, with special usefulness in critical patients. Immunomodulation, gut protection, and prevention of protein depletion are mentioned among its positive effects in such circumstances. With the intent of evaluating the tolerance and clinical impact of a glutamine supplement in seriously ill infants, a prospective randomized study was done with nine patients. Anthropometric and biochemical determinations were made, and length of stay in the intensive care unit (ICU, in the hospital, and under artificial ventilation, and septic morbidity and mortality were tabulated. Infants in the treatment group (n=5 were enterally administered 0.3 g/kg of glutamine, whereas controls received 0.3 g/kg of casein during a standard period of five days. Septic complications occurred in 75% of the controls (3/4 versus 20% of the glutamine-treated group (1/5, p<=0.10, and two patients in the control group died of bacterial infections (50% vs. 0%, p<=0.10. Days in the ICU, in the hospital, and with ventilation numerically favored glutamine therapy, although without statistical significance. The supplements were usually well tolerated, and no patient required discontinuation of the program. The conclusion was that glutamine supplementation was safe and tended to be associated with less infectious morbidity and mortality in this high-risk population.

Elevated glutamine/glutamate ratio in cerebrospinal fluid of first episode and drug naive schizophrenic patients

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Lindström Leif H

2005-01-01

Full Text Available Abstract Background Recent magnetic resonance spectroscopy (MRS studies report that glutamine is altered in the brains of schizophrenic patients. There were also conflicting findings on glutamate in cerebrospinal fluid (CSF of schizophrenic patients, and absent for glutamine. This study aims to clarify the question of glutamine and glutamate in CSF of first episode and drug naive schizophrenic patients. Method Levels of glutamine and glutamate in CSF of 25 first episode and drug-naive male schizophrenic patients and 17 age-matched male healthy controls were measured by a high performance liquid chromatography. Results The ratio (126.1 (median, 117.7 ± 27.4 (mean ± S.D. of glutamine to glutamate in the CSF of patients was significantly (z = -3.29, p = 0.001 higher than that (81.01 (median, 89.1 ± 22.5 (mean ± S.D. of normal controls although each level of glutamine and glutamate in patients was not different from that of normal controls. Conclusion Our data suggests that a disfunction in glutamate-glutamine cycle in the brain may play a role in the pathophysiology of schizophrenia.

Evidence for an operative glutamine translocator in chloroplasts from maritime pine (Pinus pinaster Ait.) cotyledons.

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Claros, M G; Aguilar, M L; Cánovas, F M

2010-09-01

In higher plants, ammonium is assimilated into amino acids through the glutamine synthetase (GS)/glutamate synthase (GOGAT) cycle. This metabolic cycle is distributed in different cellular compartments in conifer seedlings: glutamine synthesis occurs in the cytosol and glutamate synthesis within the chloroplast. A method for preparing intact chloroplasts of pine cotyledons is presented with the aim of identifying a glutamine-glutamate translocator. Glutamine-glutamate exchange has been studied using the double silicone layer system, suggesting the existence of a translocator that imports glutamine into the chloroplast and exports glutamate to the cytoplasm. The translocator identified is specific for glutamine and glutamate, and the kinetic constants for both substrates indicate that it is unsaturated at intracellular concentrations. Thus, the experimental evidence obtained supports the model of the GS/GOGAT cycle in developing pine seedlings that accounts for the stoichiometric balance of metabolites. As a result, the efficient assimilation of free ammonia produced by photorespiration, nitrate reduction, storage protein mobilisation, phenylpropanoid pathway or S-adenosylmethionine synthesis is guaranteed.

Addition of Alanyl-Glutamine to Dialysis Fluid Restores Peritoneal Cellular Stress Responses - A First-In-Man Trial.

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Klaus Kratochwill

Full Text Available Peritonitis and ultrafiltration failure remain serious complications of chronic peritoneal dialysis (PD. Dysfunctional cellular stress responses aggravate peritoneal injury associated with PD fluid exposure, potentially due to peritoneal glutamine depletion. In this randomized cross-over phase I/II trial we investigated cytoprotective effects of alanyl-glutamine (AlaGln addition to glucose-based PDF.In a prospective randomized cross-over design, 20 stable PD outpatients underwent paired peritoneal equilibration tests 4 weeks apart, using conventional acidic, single chamber 3.86% glucose PD fluid, with and without 8 mM supplemental AlaGln. Heat-shock protein 72 expression was assessed in peritoneal effluent cells as surrogate parameter of cellular stress responses, complemented by metabolomics and functional immunocompetence assays.AlaGln restored peritoneal glutamine levels and increased the primary outcome heat-shock protein expression (effect 1.51-fold, CI 1.07-2.14; p = 0.022, without changes in peritoneal ultrafiltration, small solute transport, or biomarkers reflecting cell mass and inflammation. Further effects were glutamine-like metabolomic changes and increased ex-vivo LPS-stimulated cytokine release from healthy donor peripheral blood monocytes. In patients with a history of peritonitis (5 of 20, AlaGln supplementation decreased dialysate interleukin-8 levels. Supplemented PD fluid also attenuated inflammation and enhanced stimulated cytokine release in a mouse model of PD-associated peritonitis.We conclude that AlaGln-supplemented, glucose-based PD fluid can restore peritoneal cellular stress responses with attenuation of sterile inflammation, and may improve peritoneal host-defense in the setting of PD.

Influence of glutamine on the effect of resistance exercise on cardiac ANP in rats

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Romeu Rodrigues de Souza

2015-03-01

Full Text Available Various nutritional supplements (herbs, vitamins, and micronutrients improve responses and adaptations to resistance exercise. ANP is a heart hormone that contributes to fluid, electrolyte and blood pressure homeostasis through its natriuretic and vasodilative actions. In the present study, the adaptation of ANP in response to resistance exercise was investigated in rats supplemented with glutamine for five weeks. The results showed that supplementation with glutamine did not influence the number of ANP granules per atrial cardiocyte in sedentary animals. In exercised-trained rats, the number and diameter of the granules was significantly higher in comparison with the control group and in exercised animals supplemented with glutamine there was significant increase in the number and diameter of ANP granules compared with controls. Altogether, these data indicated that in resistance exercise rats, glutamine significantly enhances cardiac ANP thus implicating the beneficial effects of glutamine supplementation to the ANP system.

Differential inhibition of adenylylated and deadenylylated forms of M. tuberculosis glutamine synthetase as a drug discovery platform.

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A Theron

Full Text Available Glutamine synthetase is a ubiquitous central enzyme in nitrogen metabolism that is controlled by up to four regulatory mechanisms, including adenylylation of some or all of the twelve subunits by adenylyl transferase. It is considered a potential therapeutic target for the treatment of tuberculosis, being essential for the growth of Mycobacterium tuberculosis, and is found extracellularly only in the pathogenic Mycobacterium strains. Human glutamine synthetase is not regulated by the adenylylation mechanism, so the adenylylated form of bacterial glutamine synthetase is of particular interest. Previously published reports show that, when M. tuberculosis glutamine synthetase is expressed in Escherichia coli, the E. coli adenylyl transferase does not optimally adenylylate the M. tuberculosis glutamine synthetase. Here, we demonstrate the production of soluble adenylylated M. tuberulosis glutamine synthetase in E. coli by the co-expression of M. tuberculosis glutamine synthetase and M. tuberculosis adenylyl transferase. The differential inhibition of adenylylated M. tuberulosis glutamine synthetase and deadenylylated M. tuberulosis glutamine synthetase by ATP based scaffold inhibitors are reported. Compounds selected on the basis of their enzyme inhibition were also shown to inhibit M. tuberculosis in the BACTEC 460TB™ assay as well as the intracellular inhibition of M. tuberculosis in a mouse bone-marrow derived macrophage assay.

Differential inhibition of adenylylated and deadenylylated forms of M. tuberculosis glutamine synthetase as a drug discovery platform.

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Theron, A; Roth, R L; Hoppe, H; Parkinson, C; van der Westhuyzen, C W; Stoychev, S; Wiid, I; Pietersen, R D; Baker, B; Kenyon, C P

2017-01-01

Glutamine synthetase is a ubiquitous central enzyme in nitrogen metabolism that is controlled by up to four regulatory mechanisms, including adenylylation of some or all of the twelve subunits by adenylyl transferase. It is considered a potential therapeutic target for the treatment of tuberculosis, being essential for the growth of Mycobacterium tuberculosis, and is found extracellularly only in the pathogenic Mycobacterium strains. Human glutamine synthetase is not regulated by the adenylylation mechanism, so the adenylylated form of bacterial glutamine synthetase is of particular interest. Previously published reports show that, when M. tuberculosis glutamine synthetase is expressed in Escherichia coli, the E. coli adenylyl transferase does not optimally adenylylate the M. tuberculosis glutamine synthetase. Here, we demonstrate the production of soluble adenylylated M. tuberulosis glutamine synthetase in E. coli by the co-expression of M. tuberculosis glutamine synthetase and M. tuberculosis adenylyl transferase. The differential inhibition of adenylylated M. tuberulosis glutamine synthetase and deadenylylated M. tuberulosis glutamine synthetase by ATP based scaffold inhibitors are reported. Compounds selected on the basis of their enzyme inhibition were also shown to inhibit M. tuberculosis in the BACTEC 460TB™ assay as well as the intracellular inhibition of M. tuberculosis in a mouse bone-marrow derived macrophage assay.

Prevention of gastrointestinal injury by using glutamine in cardiac surgery

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С. М. Ефремов

2015-10-01

Full Text Available A pilot double-blind, placebo-controlled, randomized study The aim of this study was to evaluate the efficiency of perioperative administration of glutamine to preserve intestinal integrity in patients undergoing cardiac surgery. 24 patients scheduled for elective coronary artery bypass surgery under cardiopulmonary bypass were included in this prospective, randomized, double-blind placebo controlled pilot study. 12 patients were randomized to receive glutamine (20% solution of N(2-L-alanyl-L-glutamine 0.4 g/kg a day, while the remaining 12 patients received an equivalent placebo dose (0.9% solution of NaCl. Infusion of glutamine/placebo was started after the induction of anesthesia and was continued for 24 hours. The primary end-point was dynamics of plasma concentration of a specific marker of intestinal damage, intestinal fatty acid binding protein (I-FABP. The secondary end-points were liver fatty acid binding protein (L-FABP, alpha glutathione s-transferase (aGST, heat shock protein 70 (HSP 70. There were no between-group differences of all the studied biochemical parameters at any stage of the study. Plasma I-FABP levels (median [25-75 percentile] were markedly elevated during CPB and remained the same postoperatively: 962 (577-2 067 and 883 (444-1 625 г/ml 5 min after un-clamping of aorta, 2203 (888-3 429 and 1 560 (506-2 657 г/ml 2 hours post-bypass, 897 (555-1 424 and 794 (505-951 г/ml 6 hours post-bypass in the GLN and control groups respectively. Perioperative administration of glutamine in dose of 0.4 g/kg a day does not appear to preserve intestinal integrity in low risk cardiac surgery patients.

Brain MRS glutamine as a biomarker to guide therapy of hyperammonemic coma.

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O'Donnell-Luria, Anne H; Lin, Alexander P; Merugumala, Sai K; Rohr, Frances; Waisbren, Susan E; Lynch, Rebecca; Tchekmedyian, Vatche; Goldberg, Aaron D; Bellinger, Andrew; McFaline-Figueroa, J Ricardo; Simon, Tracey; Gershanik, Esteban F; Levy, Bruce D; Cohen, David E; Samuels, Martin A; Berry, Gerard T; Frank, Natasha Y

2017-05-01

Acute idiopathic hyperammonemia in an adult patient is a life-threatening condition often resulting in a rapid progression to irreversible cerebral edema and death. While ammonia-scavenging therapies lower blood ammonia levels, in comparison, clearance of waste nitrogen from the brain may be delayed. Therefore, we used magnetic resonance spectroscopy (MRS) to monitor cerebral glutamine levels, the major reservoir of ammonia, in a gastric bypass patient with hyperammonemic coma undergoing therapy with N-carbamoyl glutamate and the ammonia-scavenging agents, sodium phenylacetate and sodium benzoate. Improvement in mental status mirrored brain glutamine levels, as coma persisted for 48h after plasma ammonia normalized. We hypothesize that the slower clearance for brain glutamine levels accounts for the delay in improvement following initiation of treatment in cases of chronic hyperammonemia. We propose MRS to monitor brain glutamine as a noninvasive approach to be utilized for diagnostic and therapeutic monitoring purposes in adult patients presenting with idiopathic hyperammonemia. Copyright © 2017 Elsevier Inc. All rights reserved.

Utilization of glutamine by the retina: an autoradiographic and metabolic study

Energy Technology Data Exchange (ETDEWEB)

Voaden, M J; Lake, N; Marshall, J; Morjaria, B [Institute of Ophthalmology, London (UK). Dept. of Visual Science

1978-10-01

The cells able to accumulate exogenously applied (/sup 3/H) glutamine in rat, cat, frog, pigeon and guinea pig retinas have been located by autoradiography, and the fate of the labelled glutamine, as regards its incorporation into aspartic, glutamic and ..gamma..-amino-butyric acids, followed for 60 min. The results support the notion of glutamine as a precursor of transmitter amino acids in some neurones. In particular, it would appear to be a source of a relatively stable pool of GABA which may be located, with species variation, in amacrine or ganglion cells. In the pigeon retina glutamate pool incorporates and retains a major percentage of the label, and perikarya in the middle of the inner nuclear layer of the tissue are predominantly labelled.

Response to Dietary Supplementation of Glutamine in Broiler Chickens Subjected to Transportation Stress

Directory of Open Access Journals (Sweden)

Majid SHAKERI

2016-07-01

Full Text Available The main purpose of this study was to determine effects of glutamine supplementation on performance and blood parameters including Hsp70 and acute phase protein when chicken were subjected to transportation stress. A total of four hundred day-old-male cobb-500 chicks were obtained directly from a local hatchery. The chicks were allotted to two groups as: immediate placement (1 hour after hatching with access to feed and water and placement after 24h transportation without access to feed and water. The experiment consisted of a factorial arrangement of 2 different diets and 2 different time of placement. Chicks from each placement group were fed either basal diet or basal diet + 1% glutamine from 1 to 21 days of age. The results indicated that dietary glutamine improved the body weight gain and feed conversion ratio significantly when chicks were subjected to delayed or immediate placement. In conclusion, supplementing chicken with glutamine in diet can reduce negative effects of delayed access to feed and water during transportation. Moreover, APP concentration and HSP70 level were positively affected when chicks supplemented with glutamine in the diet.

Lack of functional benefit with glutamine versus placebo in Duchenne muscular dystrophy: a randomized crossover trial.

Directory of Open Access Journals (Sweden)

Elise Mok

Full Text Available Oral glutamine decreases whole body protein breakdown in Duchenne muscular dystrophy (DMD. We evaluated the functional benefit of 4 months oral glutamine in DMD.30 ambulant DMD boys were included in this double-blind, randomized crossover trial with 2 intervention periods: glutamine (0.5 g/kg/d and placebo, 4 months each, separated by a 1-month wash-out, at 3 outpatient clinical investigation centers in France. Functional benefit was tested by comparing glutamine versus placebo on change in walking speed at 4 months. Secondary outcome measures were: 2-minute walk test, work, power, muscle mass (urinary creatinine, markers of myofibrillar protein breakdown (urinary 3-methyl-histidine/creatinine, serum creatine phospho-kinase, body composition (fat free mass, fat mass percentage, safety and oral nutrient intake. There was no improvement in the primary end point (walking speed or in secondary measures of muscle function (2-minute walk test, work, power in the glutamine group compared with placebo. However, subjects receiving glutamine or placebo showed no deterioration in functional measures over the course of the 9-month trial. No differences in muscle mass, markers of protein breakdown or serum creatine phosho-kinase were observed, except for a blunted increase in fat free mass in the glutamine group which led to a greater increase in fat mass percentage. Glutamine was safe and well-tolerated.This trial did not identify additional benefit of 4 months oral glutamine over placebo on muscle mass or function in ambulatory DMD boys. Although apparently safe, current data cannot support routine supplementation in this population as a whole, until further research proves otherwise.(ClinicalTrials.gov NCT00296621.

The effect of free glutamine and peptide ingestion on the rate of muscle glycogen resynthesis in man

DEFF Research Database (Denmark)

Van Hall, Gerrit; Saris, W H; van de Schoor, P A

2000-01-01

hydrolysate (26% glutamine) and 3) a whey hydrolysate (6.6% glutamine). Plasma glutamine, decreased by approximately 20% during recovery with ingestion of the control drink, no changes with ingestion of the protein hydrolysates drinks, and a 2-fold increase with ingestion of the free glutamine drinks....... The rate of glycogen resynthesis was not significantly different in the four tests: 28 +/- 5, 26 +/- 6, 33 +/- 4, and 34 +/- 3 mmol glucosyl units x kg(-1) dry weight muscle x h(-1) for the control, glutamine, wheat- and whey hydrolysate ingestion, respectively. It is concluded that ingestion...... of a glutamine/carbohydrate mixture does not increase the rate of glycogen resynthesis in muscle. Glycogen resynthesis rates were higher, although not statistically significant, after ingestion of the drink containing the wheat (21 +/- 8%) and whey protein hydrolysate (20 +/- 6%) compared to ingestion...

Maternal L-glutamine supplementation prevents prenatal alcohol exposure-induced fetal growth restriction in an ovine model.

Science.gov (United States)

Sawant, Onkar B; Wu, Guoyao; Washburn, Shannon E

2015-06-01

Prenatal alcohol exposure is known to cause fetal growth restriction and disturbances in amino acid bioavailability. Alterations in these parameters can persist into adulthood and low birth weight can lead to altered fetal programming. Glutamine has been associated with the synthesis of other amino acids, an increase in protein synthesis and it is used clinically as a nutrient supplement for low birth weight infants. The aim of this study was to explore the effect of repeated maternal alcohol exposure and L-glutamine supplementation on fetal growth and amino acid bioavailability during the third trimester-equivalent period in an ovine model. Pregnant sheep were randomly assigned to four groups, saline control, alcohol (1.75-2.5 g/kg), glutamine (100 mg/kg, three times daily) or alcohol + glutamine. In this study, a weekend binge drinking model was followed where treatment was done 3 days per week in succession from gestational day (GD) 109-132 (normal term ~147). Maternal alcohol exposure significantly reduced fetal body weight, height, length, thoracic girth and brain weight, and resulted in decreased amino acid bioavailability in fetal plasma and placental fluids. Maternal glutamine supplementation successfully mitigated alcohol-induced fetal growth restriction and improved the bioavailability of glutamine and glutamine-related amino acids such as glycine, arginine, and asparagine in the fetal compartment. All together, these findings show that L-glutamine supplementation enhances amino acid availability in the fetus and prevents alcohol-induced fetal growth restriction.

Reductive glutamine metabolism by IDH1 mediates lipogenesis under hypoxia

Science.gov (United States)

Metallo, Christian M.; Gameiro, Paulo A.; Bell, Eric L.; Mattaini, Katherine R.; Yang, Juanjuan; Hiller, Karsten; Jewell, Christopher M.; Johnson, Zachary R.; Irvine, Darrell J.; Guarente, Leonard; Kelleher, Joanne K.; Vander Heiden, Matthew G.; Iliopoulos, Othon; Stephanopoulos, Gregory

2013-01-01

Acetyl coenzyme A (AcCoA) is the central biosynthetic precursor for fatty acid synthesis and protein acetylation. In the conventional view of mammalian cell metabolism, AcCoA is primarily generated from glucose-derived pyruvate through the citrate shuttle and adenosine triphosphate citrate lyase (ACL) in the cytosol1-3. However, proliferating cells that exhibit aerobic glycolysis and those exposed to hypoxia convert glucose to lactate at near stoichiometric levels, directing glucose carbon away from the tricarboxylic acid cycle (TCA) and fatty acid synthesis4. Although glutamine is consumed at levels exceeding that required for nitrogen biosynthesis5, the regulation and utilization of glutamine metabolism in hypoxic cells is not well understood. Here we show that human cells employ reductive metabolism of alpha-ketoglutarate (αKG) to synthesize AcCoA for lipid synthesis. This isocitrate dehydrogenase 1 (IDH1) dependent pathway is active in most cell lines under normal culture conditions, but cells grown under hypoxia rely almost exclusively on the reductive carboxylation of glutamine-derived αKG for de novo lipogenesis. Furthermore, renal cell lines deficient in the von Hippel-Lindau (VHL) tumor suppressor protein preferentially utilize reductive glutamine metabolism for lipid biosynthesis even at normal oxygen levels. These results identify a critical role for oxygen in regulating carbon utilization in order to produce AcCoA and support lipid synthesis in mammalian cells. PMID:22101433

Growth factors regulate glutamine synthetase activity in ...

African Journals Online (AJOL)

Khaled

2012-07-10

Jul 10, 2012 ... glutamate and ammonia, which in turn, cells are supplied with ammonia ... out to determine the maximum growth time at which cells will be .... Western blot technique for detection the glutamine synthetase enzyme. Lane 1;.

Glutamine domain of the chimeric protein, CAD, that initiates pyrimidine biosynthesis in mammalian cells

International Nuclear Information System (INIS)

Kelly, R.E.; Kim, H.; Evans, D.R.

1986-01-01

Glutamine dependent carbamyl phosphate synthesis, the first step in mammalian de novo pyrimidine biosynthesis, is catalyzed by a 240 kDa chimeric protein, CAD, that also has the aspartate transcarbamylase and dihydroorotase activities. The complex was found to have a separate glutaminase activity of 0.04 μmol/min/mg, that increased five fold in the presence of bicarbonate and ATP. To determine whether the glutaminase activity, which provides ammonia for carbamyl phosphate synthesis, is associated with a separate structural domain (GLN), CAD was subjected to controlled proteolysis with elastase. The glutaminase, glutamine and ammonia dependent carbamyl phosphate synthetase activities, as well as the partial reactions; carbamyl phosphate dependent ATP synthesis and bicarbonate dependent ATPase, were correlated with the concentration of the various proteolytic fragments that accumulated in the digest. While the glutamine dependent carbamyl phosphate synthetase was rapidly inactivated, the glutaminase activity was found to be very resistant to proteolysis. The glutamine binding site of CAD was also specifically modified with 6-diazo-5-oxo-L-norleucine (DON). The modification was accompanied by a loss of both glutaminase and glutamine dependent carbamyl phosphate synthetase activities. Bicarbonate and ATP increased the rate of reaction of CAD with DON, while glutamine protected against inactivation. The stoichiometry of the reaction and the identity of the modified proteolytic fragments was determined using 14 C labelled DON

Randomised trial of glutamine and selenium supplemented parenteral nutrition for critically ill patients. Protocol Version 9, 19 February 2007 known as SIGNET (Scottish Intensive care Glutamine or seleNium Evaluative Trial

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Vale Luke D

2007-09-01

Full Text Available Abstract Background Mortality rates in the Intensive Care Unit and subsequent hospital mortality rates in the UK remain high. Infections in Intensive Care are associated with a 2–3 times increased risk of death. It is thought that under conditions of severe metabolic stress glutamine becomes "conditionally essential". Selenium is an essential trace element that has antioxidant and anti-inflammatory properties. Approximately 23% of patients in Intensive Care require parenteral nutrition and glutamine and selenium are either absent or present in low amounts. Both glutamine and selenium have the potential to influence the immune system through independent biochemical pathways. Systematic reviews suggest that supplementing parenteral nutrition in critical illness with glutamine or selenium may reduce infections and mortality. Pilot data has shown that more than 50% of participants developed infections, typically resistant organisms. We are powered to show definitively whether supplementation of PN with either glutamine or selenium is effective at reducing new infections in critically ill patients. Methods/design 2 × 2 factorial, pragmatic, multicentre, double-blind, randomised controlled trial. The trial has an enrolment target of 500 patients. Inclusion criteria include: expected to be in critical care for at least 48 hours, aged 16 years or over, patients who require parenteral nutrition and are expected to have at least half their daily nutritional requirements given by that route. Allocation is to one of four iso-caloric, iso-nitrogenous groups: glutamine, selenium, both glutamine & selenium or no additional glutamine or selenium. Trial supplementation is given for up to seven days on the Intensive Care Unit and subsequent wards if practicable. The primary outcomes are episodes of infection in the 14 days after starting trial nutrition and mortality. Secondary outcomes include antibiotic usage, length of hospital stay, quality of life and

Randomised trial of glutamine and selenium supplemented parenteral nutrition for critically ill patients. Protocol Version 9, 19 February 2007 known as SIGNET (Scottish Intensive care Glutamine or seleNium Evaluative Trial).

Science.gov (United States)

Andrews, Peter J D; Avenell, Alison; Noble, David W; Campbell, Marion K; Battison, Claire G; Croal, Bernard L; Simpson, William G; Norrie, John; Vale, Luke D; Cook, Jonathon; de Verteuil, Robyn; Milne, Anne C

2007-09-20

Mortality rates in the Intensive Care Unit and subsequent hospital mortality rates in the UK remain high. Infections in Intensive Care are associated with a 2-3 times increased risk of death. It is thought that under conditions of severe metabolic stress glutamine becomes "conditionally essential". Selenium is an essential trace element that has antioxidant and anti-inflammatory properties. Approximately 23% of patients in Intensive Care require parenteral nutrition and glutamine and selenium are either absent or present in low amounts. Both glutamine and selenium have the potential to influence the immune system through independent biochemical pathways. Systematic reviews suggest that supplementing parenteral nutrition in critical illness with glutamine or selenium may reduce infections and mortality. Pilot data has shown that more than 50% of participants developed infections, typically resistant organisms. We are powered to show definitively whether supplementation of PN with either glutamine or selenium is effective at reducing new infections in critically ill patients. 2 x 2 factorial, pragmatic, multicentre, double-blind, randomised controlled trial. The trial has an enrollment target of 500 patients. Inclusion criteria include: expected to be in critical care for at least 48 hours, aged 16 years or over, patients who require parenteral nutrition and are expected to have at least half their daily nutritional requirements given by that route. Allocation is to one of four iso-caloric, iso-nitrogenous groups: glutamine, selenium, both glutamine & selenium or no additional glutamine or selenium. Trial supplementation is given for up to seven days on the Intensive Care Unit and subsequent wards if practicable. The primary outcomes are episodes of infection in the 14 days after starting trial nutrition and mortality. Secondary outcomes include antibiotic usage, length of hospital stay, quality of life and cost-effectiveness. To date more than 285 patients have been

Glutamine deficiency induces DNA alkylation damage and sensitizes cancer cells to alkylating agents through inhibition of ALKBH enzymes.

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Thai Q Tran

2017-11-01

Full Text Available Driven by oncogenic signaling, glutamine addiction exhibited by cancer cells often leads to severe glutamine depletion in solid tumors. Despite this nutritional environment that tumor cells often experience, the effect of glutamine deficiency on cellular responses to DNA damage and chemotherapeutic treatment remains unclear. Here, we show that glutamine deficiency, through the reduction of alpha-ketoglutarate, inhibits the AlkB homolog (ALKBH enzymes activity and induces DNA alkylation damage. As a result, glutamine deprivation or glutaminase inhibitor treatment triggers DNA damage accumulation independent of cell death. In addition, low glutamine-induced DNA damage is abolished in ALKBH deficient cells. Importantly, we show that glutaminase inhibitors, 6-Diazo-5-oxo-L-norleucine (DON or CB-839, hypersensitize cancer cells to alkylating agents both in vitro and in vivo. Together, the crosstalk between glutamine metabolism and the DNA repair pathway identified in this study highlights a potential role of metabolic stress in genomic instability and therapeutic response in cancer.

Glutamine deficiency induces DNA alkylation damage and sensitizes cancer cells to alkylating agents through inhibition of ALKBH enzymes.

Science.gov (United States)

Tran, Thai Q; Ishak Gabra, Mari B; Lowman, Xazmin H; Yang, Ying; Reid, Michael A; Pan, Min; O'Connor, Timothy R; Kong, Mei

2017-11-01

Driven by oncogenic signaling, glutamine addiction exhibited by cancer cells often leads to severe glutamine depletion in solid tumors. Despite this nutritional environment that tumor cells often experience, the effect of glutamine deficiency on cellular responses to DNA damage and chemotherapeutic treatment remains unclear. Here, we show that glutamine deficiency, through the reduction of alpha-ketoglutarate, inhibits the AlkB homolog (ALKBH) enzymes activity and induces DNA alkylation damage. As a result, glutamine deprivation or glutaminase inhibitor treatment triggers DNA damage accumulation independent of cell death. In addition, low glutamine-induced DNA damage is abolished in ALKBH deficient cells. Importantly, we show that glutaminase inhibitors, 6-Diazo-5-oxo-L-norleucine (DON) or CB-839, hypersensitize cancer cells to alkylating agents both in vitro and in vivo. Together, the crosstalk between glutamine metabolism and the DNA repair pathway identified in this study highlights a potential role of metabolic stress in genomic instability and therapeutic response in cancer.

Proximal tubule-specific glutamine synthetase deletion alters basal and acidosis-stimulated ammonia metabolism

NARCIS (Netherlands)

Lee, Hyun-Wook; Osis, Gunars; Handlogten, Mary E.; Lamers, Wouter H.; Chaudhry, Farrukh A.; Verlander, Jill W.; Weiner, I. David

2016-01-01

Glutamine synthetase (GS) catalyzes the recycling of NH4 (+) with glutamate to form glutamine. GS is highly expressed in the renal proximal tubule (PT), suggesting ammonia recycling via GS could decrease net ammoniagenesis and thereby limit ammonia available for net acid excretion. The purpose of

Structure-Function Relationship of Transporters in the Glutamate–Glutamine Cycle of the Central Nervous System

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Mariko Kato Hayashi

2018-04-01

Full Text Available Many kinds of transporters contribute to glutamatergic excitatory synaptic transmission. Glutamate is loaded into synaptic vesicles by vesicular glutamate transporters to be released from presynaptic terminals. After synaptic vesicle release, glutamate is taken up by neurons or astrocytes to terminate the signal and to prepare for the next signal. Glutamate transporters on the plasma membrane are responsible for transporting glutamate from extracellular fluid to cytoplasm. Glutamate taken up by astrocyte is converted to glutamine by glutamine synthetase and transported back to neurons through glutamine transporters on the plasma membranes of the astrocytes and then on neurons. Glutamine is converted back to glutamate by glutaminase in the neuronal cytoplasm and then loaded into synaptic vesicles again. Here, the structures of glutamate transporters and glutamine transporters, their conformational changes, and how they use electrochemical gradients of various ions for substrate transport are summarized. Pharmacological regulations of these transporters are also discussed.

effects of enteral glutamine supplementation on reduction

African Journals Online (AJOL)

Objective: To determine the effect of enteral glutamine in reducing the incidence of ... in use. These modalities include among others; topical antibacterial agents, early excision of eschar, and ... in the burns unit and plastic surgery ward 4D of.

Quantitation and localisation of (in vitro) transglutaminase-catalysed glutamine hydroxylation using mass spectrometry

NARCIS (Netherlands)

Piersma, S.R.; Pijpekamp, A. van de; Wijngaards, G.; Gruppen, H.; Boumans, H.

2002-01-01

A mass spectrometric approach was chosen to quantify and localise in vitro enzymatically modified glutamine (Gln) residues in a glutamine-rich protein. This protein (named dB1), a cloned domain of the high molecular weight wheat glutenin subunit Dx5, was modified by microbial transglutaminase

Serum Glutamine Levels as a Potential Diagnostic Biomarker in Sepsis following Surgery for Peritonitis.

Science.gov (United States)

Yang, Chun-Ju; Huang, Ting-Shuo; Lee, Tung-Liang; Yang, Kang-Chung; Yuan, Shin-Sheng; Lu, Ruey-Hwa; Hsieh, Chung-Ho; Shyu, Yu-Chiau

2017-12-31

Few diagnostic biomarkers for sepsis after emergency peritonitis surgery are available to clinicians, and, thus, it is important to develop new biomarkers for patients undergoing this procedure. We investigated whether serum glutamine and selenium levels could be diagnostic biomarkers of sepsis in individuals recovering from emergency peritonitis surgery. From February 2012 to March 2013, patients who had peritonitis diagnosed at the emergency department and underwent emergency surgery were screened for eligibility. Serum glutamine and selenium levels were obtained at pre-operative, post-operative and recovery time points. The average level of pre-operation serum glutamine was significantly different from that on the recovery day (0.317 ± 0.168 vs. 0.532 ± 0.155 mM, P peritonitis. We recommend including glutamine as a biomarker for sepsis severity assessment in addition to the commonly used clinical indicators.

The utilization of glutamine by the retina: an autoradiographic and metabolic study

International Nuclear Information System (INIS)

Voaden, M.J.; Lake, N.; Marshall, J.; Morjaria, B.

1978-01-01

The cells able to accumulate exogenously applied [ 3 H] glutamine in rat, cat, frog, pigeon and guinea pig retinas have been located by autoradiography, and the fate of the labelled glutamine, as regards its incorporation into aspartic, glutamic and γ-amino-butyric acids, followed for 60 min. The results support the notion of glutamine as a precursor of transmitter amino acids in some neurones. In particular, it would appear to be a source of a relatively stable pool of GABA which may be located, with species variation, in amacrine or ganglion cells. In the pigeon retina glutamate pool incorporates and retains a major percentage of the label, and perikarya in the middle of the inner nuclear layer of the tissue are predominantly labelled. (author)

Distinctive properties and expression profiles of glutamine synthetase from a plant symbiotic fungus.

Science.gov (United States)

Montanini, Barbara; Betti, Marco; Márquez, Antonio J; Balestrini, Raffaella; Bonfante, Paola; Ottonello, Simone

2003-01-01

The nucleotide sequences reported in this paper have been submitted to the GenBank(R)/EBI Nucleotide Sequence Databases with accession numbers AF462037 (glutamine synthetase) and AF462032 (glutamate synthase). Nitrogen retrieval and assimilation by symbiotic ectomycorrhizal fungi is thought to play a central role in the mutualistic interaction between these organisms and their plant hosts. Here we report on the molecular characterization of the key N-assimilation enzyme glutamine synthetase from the mycorrhizal ascomycete Tuber borchii (TbGS). TbGS displayed a strong positive co-operativity ( n =1.7+/-0.29) and an unusually high S(0.5) value (54+/-16 mM; S(0.5) is the substrate concentration value at which v =(1/2) V (max)) for glutamate, and a correspondingly low sensitivity towards inhibition by the glutamate analogue herbicide phosphinothricin. The TbGS mRNA, which is encoded by a single-copy gene in the Tuber genome, was up-regulated in N-starved mycelia and returned to basal levels upon resupplementation of various forms of N, the most effective of which was nitrate. Both responses were accompanied by parallel variations of TbGS protein amount and glutamine synthetase activity, thus indicating that TbGS levels are primarily controlled at the pre-translational level. As revealed by a comparative analysis of the TbGS mRNA and of the mRNAs for the metabolically related enzymes glutamate dehydrogenase and glutamate synthase, TbGS is not only the sole messenger that positively responds to N starvation, but also the most abundant under N-limiting conditions. A similar, but even more discriminating expression pattern, with practically undetectable glutamate dehydrogenase mRNA levels, was observed in fruitbodies. The TbGS mRNA was also found to be expressed in symbiosis-engaged hyphae, with distinctively higher hybridization signals in hyphae that were penetrating among and within root cells. PMID:12683951

Prefrontal changes in the glutamate-glutamine cycle and neuronal/glial glutamate transporters in depression with and without suicide

NARCIS (Netherlands)

Zhao, J.; Verwer, R.W.H.; van Wamelen, D.J.; Qi, X.R.; Gao, S.F.; Lucassen, P.J.; Swaab, D.F.

2016-01-01

There are indications for changes in glutamate metabolism in relation to depression or suicide. The glutamate-glutamine cycle and neuronal/glial glutamate transporters mediate the uptake of the glutamate and glutamine. The expression of various components of the glutamate-glutamine cycle and the

Glutamine synthetase gene evolution: A good molecular clock

International Nuclear Information System (INIS)

Pesole, G.; Lanvave, C.; Saccone, C.; Bozzetti, M.P.; Preparata, G.

1991-01-01

Glutamine synthetase gene evolution in various animals, plants, and bacteria was evaluated by a general stationary Markov model. The evolutionary process proved to be unexpectedly regular even for a time span as long as that between the divergence of prokaryotes from eukaryotes. This enabled us to draw phylogenetic trees for species whose phylogeny cannot be easily reconstructed from the fossil record. The calculation of the times of divergence of the various organelle-specific enzymes led us to hypothesize that the pea and bean chloroplast genes for these enzymes originated from the duplication of nuclear genes as a result of the different metabolic needs of the various species. The data indicate that the duplication of plastid glutamine synthetase genes occurred long after the endosymbiotic events that produced the organelles themselves

Brain glutamine synthesis requires neuronal-born aspartate as amino donor for glial glutamate formation.

Science.gov (United States)

Pardo, Beatriz; Rodrigues, Tiago B; Contreras, Laura; Garzón, Miguel; Llorente-Folch, Irene; Kobayashi, Keiko; Saheki, Takeyori; Cerdan, Sebastian; Satrústegui, Jorgina

2011-01-01

The glutamate-glutamine cycle faces a drain of glutamate by oxidation, which is balanced by the anaplerotic synthesis of glutamate and glutamine in astrocytes. De novo synthesis of glutamate by astrocytes requires an amino group whose origin is unknown. The deficiency in Aralar/AGC1, the main mitochondrial carrier for aspartate-glutamate expressed in brain, results in a drastic fall in brain glutamine production but a modest decrease in brain glutamate levels, which is not due to decreases in neuronal or synaptosomal glutamate content. In vivo (13)C nuclear magnetic resonance labeling with (13)C(2)acetate or (1-(13)C) glucose showed that the drop in brain glutamine is due to a failure in glial glutamate synthesis. Aralar deficiency induces a decrease in aspartate content, an increase in lactate production, and lactate-to-pyruvate ratio in cultured neurons but not in cultured astrocytes, indicating that Aralar is only functional in neurons. We find that aspartate, but not other amino acids, increases glutamate synthesis in both control and aralar-deficient astrocytes, mainly by serving as amino donor. These findings suggest the existence of a neuron-to-astrocyte aspartate transcellular pathway required for astrocyte glutamate synthesis and subsequent glutamine formation. This pathway may provide a mechanism to transfer neuronal-born redox equivalents to mitochondria in astrocytes.

Effects of various glutamine concentrations on gene expression and steviol glycosides accumulation in Stevia rebaudiana Bertoni.

Science.gov (United States)

Esmaeili, Fatemeh; Ghaheri, Matin; Kahrizi, Danial; Mansouri, Mohsen; Safavi, Seyed Mehdi; Ghorbani, Tayebeh; Muhammadi, Sarre; Rahmanian, Elham; Vaziri, Siavash

2018-02-10

Stevia rebaudiana Bertoni is one of the most important biologically sourced and low-calorie sweeteners that contains a lots of Steviol glycosides. Tissue culture is the best method for propagation of stevia and micro nutrients can affect both morphological traits and steviol glycosides production. In the present study, we investigated the effect of different concentrations of glutamine (10, 20, 30 and 40 g/l) on expression of UGT74G1 and UGT76G1 genes and stevioside and rebaudioside A accumulation in the leaves of stevia under in vitro conditions. The highest level of expression for UGT74G1 (1.000 Total lab unit) was seen at plants grown in MS media without glutamine and the highest gene expression level for UGT76G1 (1.321 Total lab unit) was observed at plants grown in 2% glutamine. Based on HPLC results, the highest amount of stevioside (22.74) was accumulated in plants which were under 3% glutamine treatment and the lowest production level of stevioside (16.19) was resulted under MS (0 glutamine) medium. The highest rebaudioside A (12.19) accumulation was observed under 2% glutamine treatment and the lowest accumulation of rebaudioside A (8.41) was seen at plants grown in MS medium.

Effect of glutamine synthetase inhibition on brain and interorgan ammonia metabolism in bile duct ligated rats.

Science.gov (United States)

Fries, Andreas W; Dadsetan, Sherry; Keiding, Susanne; Bak, Lasse K; Schousboe, Arne; Waagepetersen, Helle S; Simonsen, Mette; Ott, Peter; Vilstrup, Hendrik; Sørensen, Michael

2014-03-01

Ammonia has a key role in the development of hepatic encephalopathy (HE). In the brain, glutamine synthetase (GS) rapidly converts blood-borne ammonia into glutamine which in high concentrations may cause mitochondrial dysfunction and osmolytic brain edema. In astrocyte-neuron cocultures and brains of healthy rats, inhibition of GS by methionine sulfoximine (MSO) reduced glutamine synthesis and increased alanine synthesis. Here, we investigate effects of MSO on brain and interorgan ammonia metabolism in sham and bile duct ligated (BDL) rats. Concentrations of glutamine, glutamate, alanine, and aspartate and incorporation of (15)NH(4)(+) into these amino acids in brain, liver, muscle, kidney, and plasma were similar in sham and BDL rats treated with saline. Methionine sulfoximine reduced glutamine concentrations in liver, kidney, and plasma but not in brain and muscle; MSO reduced incorporation of (15)NH(4)(+) into glutamine in all tissues. It did not affect alanine concentrations in any of the tissues but plasma alanine concentration increased; incorporation of (15)NH(4)(+) into alanine was increased in brain in sham and BDL rats and in kidney in sham rats. It inhibited GS in all tissues examined but only in brain was an increased incorporation of (15)N-ammonia into alanine observed. Liver and kidney were important for metabolizing blood-borne ammonia.

Protective effects of L-glutamine against toxicity of deltamethrin in the cerebral tissue

Directory of Open Access Journals (Sweden)

Varol S

2016-04-01

Full Text Available Sefer Varol, Hasan Hüseyin Özdemir, Mehmet Uğur Çevik, Yaşar Altun, Ibrahim Ibiloğlu, Aysun Ekinci, Aslıhan Okan Ibiloğlu, Metin Balduz, Demet Arslan, Recep Tekin, Fesih Aktar, Mehmet Ufuk Aluçlu Department of Neurology, Faculty of Medicine, Dicle University, Diyarbakir, Turkey Background: Deltamethrin (DLM is a broad-spectrum synthetic dibromo-pyrethroid pesticide that is widely used for agricultural and veterinary purposes. However, human exposure to the pesticide leads to neurotoxicity. Glutamine is one of the principal, free intracellular amino acids and may also be an antioxidant. This study was undertaken in order to examine the neuroprotective and antioxidant potential of L-glutamine against DLM toxicity in female Wistar albino rats. Materials and methods: The rats were divided into the following groups (n=10: Group I: control (distilled water; 10 mL/kg, po one dose, Group II: L-glutamine (1.5 g/kg, po one dose, Group III: DLM (35 mg/kg, po one dose, and Group IV: DLM (35 mg/kg, po one dose and L-glutamine (1.5 g/kg, po one dose after 4 hours. Total oxidant status (TOS, total antioxidant status (TAS, tumor necrosis factor-α, interleukin (IL-1β, and IL-6 levels and apoptosis were evaluated in brain tissue. Results: DLM-treated animals had a significant increase in brain biochemical parameters, as well as TOS and TAS. Furthermore, the histopathological examination showed neuronal cell degeneration in the cerebral tissue. L-Glutamine treatment decreased the elevated brain levels of TOS and neuronal cell degeneration. There was no difference in tumor necrosis factor-α, IL-1β, and IL-6 levels between the groups. Conclusion: L-Glutamine may reduce the toxic effects of DLM in the cerebral tissue through antioxidant properties. Keywords: deltamethrin, L-glutamine, rat

Plasma glutamine is a minor precursor for the synthesis of citrulline: A multispecies study

Science.gov (United States)

Glutamine is considered the main precursor for citrulline synthesis in many species, including humans. The transfer of 15N from 2[15N]-glutamine to citrulline has been used as evidence for this precursor-product relationship. However, work in mice has shown that nitrogen and carbon tracers follow di...

Glutamine reduces postprandial glycemia and augments the glucagon-like peptide-1 response in type 2 diabetes patients

DEFF Research Database (Denmark)

Samocha-Bonet, Dorit; Wong, Olivia; Synnott, Emma-Leigh

2011-01-01

Impaired glucagon-like peptide (GLP-1) secretion or response may contribute to ineffective insulin release in type 2 diabetes. The conditionally essential amino acid glutamine stimulates GLP-1 secretion in vitro and in vivo. In a randomized, crossover study, we evaluated the effect of oral...... glutamine, with or without sitagliptin (SIT), on postprandial glycemia and GLP-1 concentration in 15 type 2 diabetes patients (glycated hemoglobin 6.5 ± 0.6%). Participants ingested a low-fat meal (5% fat) after receiving either water (control), 30 g l-glutamine (Gln-30), 15 g L-glutamine (Gln-15), 100 mg...... concentration and limiting postprandial glycemia in type 2 diabetes....

Effect of rapid weight loss and glutamine supplementation on immunosuppression of combat athletes: a double-blind, placebo-controlled study.

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Tritto, Aline C C; Amano, Mariane T; De Cillo, Maria E; Oliveira, Vinicius A; Mendes, Sandro H; Yoshioka, Caroline; Roschel, Hamilton; Camara, Niels Olsen S; Gualano, Bruno; Artioli, Guilherme G

2018-02-01

The role of plasma glutamine concentration and glutamine supplementation on immunosuppression was investigated in combat athletes. Twenty-three male athletes were randomly assigned to receive glutamine (21 g/day, n=12) or placebo (ovalbumin, n=11) for 10 days. Six athletes who did not lose weight served as controls. Athletes were assessed 21 days before (-21d), 1 day before (-1d) and 5 days after (+5d) a competition. Weight reduction was similar between glutamine (-8.2%± 4.1%) and placebo (-8.5%±2.4%) and negligible in control (-0.6%±1.4%). In both weight-loss groups, the majority of athletes reported symptoms of upper respiratory symptoms, as assessed by the Wisconsin upper respiratory symptom survey questionnaire. Only two athletes reported symptoms in the control group. Immune cell function remained unchanged throughout the study except for an increase in neutrophil phagocytic activity (placebo: -21d=5,251±2,986; -1d=17,428±22,374; +5d=21,125±21,934; glutamine: -21d=6,096±3,549; -1d=11,029±17,113; +5d=28,186±21,032 FI) and a minor change in monocyte phagocytic activity (placebo: -21d=4,421±3,634; -1d=3,329±6,283; +5d=3,243± 2,553; glutamine: -21d=4,051±3,186; -1d=3,106±2,625; +5d=4,981± 4,598) in both glutamine and placebo after weight loss. Plasma glutamine and cortisol remained unchanged across the study. creatine kinase levels were increased in placebo (-21d=125.2±54.1; -1d=187.2± 73.5; +5d=111.3±59.1 U/L) but not in glutamine (-21d=136.2±58.2; -1d= 168.8±65.0; +5d=129.7±64.0 U/L). Rapid weight loss increased the frequency and severity of infection symptoms, but this was neither associated with plasma glutamine depletion nor counteracted by glutamine supplementation.

Effects of L-glutamine supplementation on maternal and fetal hemodynamics in gestating ewes exposed to alcohol

OpenAIRE

Sawant, Onkar B.; Ramadoss, Jayanth; Hankins, Gary D.; Wu, Guoyao; Washburn, Shannon E.

2014-01-01

Not much is known about effects of gestational alcohol exposure on maternal and fetal cardiovascular adaptations. This study determined whether maternal binge alcohol exposure and L-glutamine supplementation could affect maternal-fetal hemodynamics and fetal regional brain blood flow during the brain growth spurt period. Pregnant sheep were randomly assigned to one of four groups: saline control, alcohol (1.75–2.5 g/kg body weight), glutamine (100 mg/kg body weight) or alcohol + glutamine. A ...

Cerebral glucose metabolism and the glutamine cycle as detected by in vivo and in vitro 13C NMR spectroscopy.

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García-Espinosa, María A; Rodrigues, Tiago B; Sierra, Alejandra; Benito, Marina; Fonseca, Carla; Gray, Heather L; Bartnik, Brenda L; García-Martín, María L; Ballesteros, Paloma; Cerdán, Sebastián

2004-01-01

We review briefly 13C NMR studies of cerebral glucose metabolism with an emphasis on the roles of glial energetics and the glutamine cycle. Mathematical modeling analysis of in vivo 13C turnover experiments from the C4 carbons of glutamate and glutamine are consistent with: (i) the glutamine cycle being the major cerebral metabolic route supporting glutamatergic neurotransmission, (ii) glial glutamine synthesis being stoichiometrically coupled to glycolytic ATP production, (iii) glutamine serving as the main precursor of neurotransmitter glutamate and (iv) glutamatergic neurotransmission being supported by lactate oxidation in the neurons in a process accounting for 60-80% of the energy derived from glucose catabolism. However, more recent experimental approaches using inhibitors of the glial tricarboxylic acid (TCA) cycle (trifluoroacetic acid, TFA) or of glutamine synthase (methionine sulfoximine, MSO) reveal that a considerable portion of the energy required to support glutamine synthesis is derived from the oxidative metabolism of glucose in the astroglia and that a significant amount of the neurotransmitter glutamate is produced from neuronal glucose or lactate rather than from glial glutamine. Moreover, a redox switch has been proposed that allows the neurons to use either glucose or lactate as substrates for oxidation, depending on the relative availability of these fuels under resting or activation conditions, respectively. Together, these results suggest that the coupling mechanisms between neuronal and glial metabolism are more complex than initially envisioned.

Ammonium absorption mechanism of rice seedling roots and 15N-labelling pattern of their glutamine-amide group, 2

International Nuclear Information System (INIS)

Arima, Yasuhiro; Kumazawa, Kikuo

1975-01-01

The processes of producing glutamine and asparagine at the initial stage of the absorption and assimilation of ammonia in rice seedling roots were examined in relation to glutamic acid, aspartic acid and ammonia by 15 N-labelling method. When ( 15 NH 4 ) 2 SO 4 was absorbed into the roots, 15 N concentration appeared very high in glutamine-amide radical and ammonia. It was also higher in amide radical than in amino radical in both glutamine and asparagine, while 15 N concentration in the amino radical of glutamine and asparagine were far lower than that of corresponding glutamine acid and aspartic acid. From these facts, glutamine-amide radical seems to be produced directly from the ammonia in culture media at the contact point of root cells and the culture media, while there is some possibility that asparagine-amide radical is formed from other amino compounds than ammonia. Also the amino radical of aspartic acid seems to be produced not only by the transamination from glutamic acid but also by the reductive amination of oxalautic acid by ammonium. (Kobatake, H.)

Intravenous glutamine enhances COX-2 activity giving cardioprotection.

LENUS (Irish Health Repository)

McGuinness, Jonathan

2009-03-01

Preconditioning, a highly evolutionary conserved endogenous protective response, provides the most powerful form of anti-infarct protection known. We investigated whether acute intravenous glutamine, through an effect on cyclooxygenase (COX)-2 and heat shock protein (HSP) 72, might induce preconditioning.

Reaction Mechanism of Mycobacterium Tuberculosis Glutamine Synthetase Using Quantum Mechanics/Molecular Mechanics Calculations.

Science.gov (United States)

Moreira, Cátia; Ramos, Maria J; Fernandes, Pedro Alexandrino

2016-06-27

This paper is devoted to the understanding of the reaction mechanism of mycobacterium tuberculosis glutamine synthetase (mtGS) with atomic detail, using computational quantum mechanics/molecular mechanics (QM/MM) methods at the ONIOM M06-D3/6-311++G(2d,2p):ff99SB//B3LYP/6-31G(d):ff99SB level of theory. The complete reaction undergoes a three-step mechanism: the spontaneous transfer of phosphate from ATP to glutamate upon ammonium binding (ammonium quickly loses a proton to Asp54), the attack of ammonia on phosphorylated glutamate (yielding protonated glutamine), and the deprotonation of glutamine by the leaving phosphate. This exothermic reaction has an activation free energy of 21.5 kcal mol(-1) , which is consistent with that described for Escherichia coli glutamine synthetase (15-17 kcal mol(-1) ). The participating active site residues have been identified and their role and energy contributions clarified. This study provides an insightful atomic description of the biosynthetic reaction that takes place in this enzyme, opening doors for more accurate studies for developing new anti-tuberculosis therapies. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

[Effect of glutamine on small intestinal repair in weanling rats after chronic diarrhea].

Science.gov (United States)

Huang, Zu-xiong; Ye, Li-yan; Zheng, Zhi-yong; Chen, Xin-min; Ren, Rong-na; Tong, Guo-yuan

2005-05-01

To investigate the nutrient effect of glutamine on small intestinal repair in weanling rats after chronic diarrhea. Forty 21-day-old wistar rats were randomly divided into five groups (8 in each). Animal model of chronic diarrhea was induced by a lactose enriched diet in the weanling Wistar rat, normal control group was fed with a standard semipurified diet, and after 14 days the rats in both groups were killed to test the establishment of the model. After the establishment of the model, the other groups were fed with the standard semipurified diet to recover for 7 days, and were randomly divided into three groups: non-intervention group, glutamine (Gln)-intervention group and control group. Glutamine concentrations in blood was detected by high-performance liquid chromatography (HPLC). Morphological changes including villus height and villus surface area of the jejunum were measured under a light microscope and electron microscope, expression of proliferating cell nuclear antigen (PCNA) as an index of cell proliferation was observed using immunohistochemical staining and image analysis. The diarrhea rate in model group was 100 percent, average diarrhea index was 1.16 +/- 0.06, but both diarrhea rate and average diarrhea index in control group were 0 (P body weight, plasma Gln concentration, villus height, villus surface area and expression of PCNA in non-intervened group compared with the control group (P body weight, villus height and villus surface area in Gln-intervened group compared with control group (P 0.05). And compared with non-intervened group, except for body weight (P > 0.05), plasma glutamine, villus height, villus surface area and expression of PCNA were all significantly increased in Gln-intervened group. Chronic diarrhea can induce malnutrition and reduce the villus height, villus surface area, expression of PCNA and plasm glutamine concentration. Oral glutamine could improve the proliferation of crypt cell and promote repair of intestinal mucosa

The effect of glutamine-enriched enteral nutrition on intestinal permeability in very-low-birth-weight infants : A randomized controlled trial

NARCIS (Netherlands)

van den Berg, Anemone; Fetter, Willem P. F.; Westerbeek, Elisabeth A. M.; van der Vegt, Ina M.; van der Molen, Hilda R. A.; van Elburg, Ruurd M.

2006-01-01

Background: Very-low-birth-weight (VLBW) infants are susceptible to glutamine depletion. Glutamine depletion has negative effects on intestinal integrity. The lower infection rate in VLBW infants receiving glutamine-enriched enteral nutrition may originate from improved intestinal integrity, as

The effect of glutamine-enriched enteral nutrition on intestinal permeability in very-low-birth-weight infants: A randomized controlled trial

NARCIS (Netherlands)

van den Berg, Anemone; Fetter, Willem P. F.; Westerbeek, Elisabeth A. M.; van der Vegt, Ina M.; van der Molen, Hilda R. A.; van Elburg, Ruurd M.

2006-01-01

Background: Very-low-birth-weight (VLBW) infants are susceptible to glutamine depletion. Glutamine depletion has negative effects on intestinal integrity. The lower infection rate in VLBW infants receiving glutamine-enriched enteral nutrition may originate from improved intestinal integrity, as

De Novo Glutamine Synthesis

Science.gov (United States)

He, Qiao; Shi, Xinchong; Zhang, Linqi; Yi, Chang; Zhang, Xuezhen

2016-01-01

Purpose: The aim of this study was to investigate the role of de novo glutamine (Gln) synthesis in the proliferation of C6 glioma cells and its detection with 13N-ammonia. Methods: Chronic Gln-deprived C6 glioma (0.06C6) cells were established. The proliferation rates of C6 and 0.06C6 cells were measured under the conditions of Gln deprivation along with or without the addition of ammonia or glutamine synthetase (GS) inhibitor. 13N-ammonia uptake was assessed in C6 cells by gamma counting and in rats with C6 and 0.06C6 xenografts by micro–positron emission tomography (PET) scanning. The expression of GS in C6 cells and xenografts was assessed by Western blotting and immunohistochemistry, respectively. Results: The Gln-deprived C6 cells showed decreased proliferation ability but had a significant increase in GS expression. Furthermore, we found that low concentration of ammonia was sufficient to maintain the proliferation of Gln-deprived C6 cells, and 13N-ammonia uptake in C6 cells showed Gln-dependent decrease, whereas inhibition of GS markedly reduced the proliferation of C6 cells as well as the uptake of 13N-ammoina. Additionally, microPET/computed tomography exhibited that subcutaneous 0.06C6 xenografts had higher 13N-ammonia uptake and GS expression in contrast to C6 xenografts. Conclusion: De novo Gln synthesis through ammonia–glutamate reaction plays an important role in the proliferation of C6 cells. 13N-ammonia can be a potential metabolic PET tracer for Gln-dependent tumors. PMID:27118759

[Cardioprotective effects of glutamine in patients with ischemic heart disease operated under conditions of extracorporeal blood circulation].

Science.gov (United States)

Lomivorotov, V V; Efremov, S M; Shmyrev, V A; Ponomarev, D N; Sviatchenko, A V; Kniaz'kova, L G

2012-01-01

It was conducted a study of glutamine cardioptotective effects during perioperative use in patients with ischemic heart disease, operated under CB. Exclusion criteria were: left ventricular ejection fraction less than 50%, diabetes melitus, myocardial infarction less than 3 months ago, Patients of the study group (n=25) had glutamine (20% solution N(2)-L-alanine-L-glutamine ("Dipeptiven" Fresenius Kabi, Germany); 0.4 g/kg/day. Patients of control group (n=25) received placebo (0.9% NaCl solution). The main indicators were the dynamics of troponin I, as well as central hemodynamics parameters. On the 1-st day after operation the concentration of troponin I was significantly lower in the glutamine-group compared placebo-group (1.280 (0.840-2.230) 2.410 (1.060-6.600) ng/ml; p=0.035). 4 hours after CB in a glutamine-group also had significantly large indicators of cardiac index (2.58 (2.34-2.91) l/min/m2 vs 2.03 (1.76-2.32)) l/min/m2; p=0,002) and stroke index (32.8 (27.8-36.0.) ml/m2 vs 26.1 (22.6-31.8) ml/m2; p=0.023). Systemic vascular resistance index was significantly lower in glutamine-group (1942 (1828-2209) dyn x s/cm(-5)/m2 vs 2456 (2400-3265) dyn x s/cm(-5)/m2; p=0.001). Conclusion. Perioperative use of N(2)-L-alanine-L-glutamine during the first 24 hours ofperioperative period gives cardioprotective effect in patients with ischemic heart disease operated under CB.

Glutamine Supplemented Parenteral Nutrition to Prevent Ventilator-Associated Pneumonia in the Intensive Care Unit

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Meltem Türkay Aydoğmuş

2012-12-01

Full Text Available Objective: Ventilator-associated pneumonia (VAP is a form of nosocomial pneumonia that increases patient morbidity and mortality, length of hospital stay, and healthcare costs. Glutamine preserves the intestinal mucosal structure, increases immune function, and reduces harmful changes in gut permeability in patients receiving total parenteral nutrition (TPN. We hypothesized that TPN supplemented by glutamine might prevent the development of VAP in patients on mechanical ventilator support in the intensive care unit (ICU. Material and Methods: With the approval of the ethics committee and informed consent from relatives, 60 patients who were followed in the ICU with mechanical ventilator support were included in our study. Patients were divided into three groups. The first group received enteral nutrition (n=20, and the second was prescribed TPN (n=20 while the third group was given glutamine-supplemented TPN (n=20. C-reactive protein (CRP, sedimentation rate, body temperature, development of purulent secretions, increase in the amount of secretions, changes in the characteristics of secretions and an increase in requirement of deep tracheal aspiration were monitored for seven days by daily examination and radiographs. Results: No statistically significant difference was found among groups in terms of development of VAP (p=0.622. Conclusion: Although VAP developed at a lower rate in the glutamine-supplemented TPN group, no statistically significant difference was found among any of the groups. Glutamine-supplemented TPN may have no superiority over unsupplemented enteral and TPN in preventing VAP.

Glutamine supplemented parenteral nutrition to prevent ventilator-associated pneumonia in the intensive care unit.

Science.gov (United States)

Aydoğmuş, Meltem Türkay; Tomak, Yakup; Tekin, Murat; Katı, Ismail; Hüseyinoğlu, Urfettin

2012-12-01

Ventilator-associated pneumonia (VAP) is a form of nosocomial pneumonia that increases patient morbidity and mortality, length of hospital stay, and healthcare costs. Glutamine preserves the intestinal mucosal structure, increases immune function, and reduces harmful changes in gut permeability in patients receiving total parenteral nutrition (TPN). We hypothesized that TPN supplemented by glutamine might prevent the development of VAP in patients on mechanical ventilator support in the intensive care unit (ICU). With the approval of the ethics committee and informed consent from relatives, 60 patients who were followed in the ICU with mechanical ventilator support were included in our study. Patients were divided into three groups. The first group received enteral nutrition (n=20), and the second was prescribed TPN (n=20) while the third group was given glutamine-supplemented TPN (n=20). C-reactive protein (CRP), sedimentation rate, body temperature, development of purulent secretions, increase in the amount of secretions, changes in the characteristics of secretions and an increase in requirement of deep tracheal aspiration were monitored for seven days by daily examination and radiographs. No statistically significant difference was found among groups in terms of development of VAP (p=0.622). Although VAP developed at a lower rate in the glutamine-supplemented TPN group, no statistically significant difference was found among any of the groups. Glutamine-supplemented TPN may have no superiority over unsupplemented enteral and TPN in preventing VAP.

L-glutamine supplementation prevents the development of experimental diabetic cardiomyopathy in streptozotocin-nicotinamide induced diabetic rats.

Directory of Open Access Journals (Sweden)

Sachin L Badole

Full Text Available The objective of the present investigation was to evaluate the effect of L-glutamine on cardiac myopathy in streptozotocin-nicotinamide induced diabetic rats. Diabetes was induced in overnight fasted Sprague Dawely rats by using intraperitonial injection of streptozotocin (55 mg/kg. Nicotinamide (100 mg/kg, i.p. was administered 20 min before administration of streptozotocin. Experimental rats were divided into Group I: non-diabetic control (distilled water; 10 ml/kg, p.o., II: diabetic control (distilled water, 10 ml/kg, p.o., III: L-glutamine (500 mg/kg, p.o. and IV: L-glutamine (1000 mg/kg, p.o.. All groups were diabetic except group I. The plasma glucose level, body weight, electrocardiographic abnormalities, hemodynamic changes and left ventricular contractile function, biological markers of cardiotoxicity, antioxidant markers were determined after 4 months after STZ with nicotinamide injection. Histopathological changes of heart tissue were carried out by using H and E stain. L-glutamine treatment improved the electrocardiographic, hemodynamic changes; LV contractile function; biological markers; oxidative stress parameters and histological changes in STZ induced diabetic rats. Results from the present investigation demonstrated that L-glutamine has seemed a cardioprotective activity.

The standard enthalpies of formation of L-asparagine and L-{alpha}-glutamine

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Contineanu, Iulia, E-mail: icontineanu@yahoo.com [Institute of Physical Chemistry ' I.G. Murgulescu' , Spl. Independentei 202, Bucharest (Romania); Neacsu, Ana, E-mail: anna_matache@yahoo.com [Institute of Physical Chemistry ' I.G. Murgulescu' , Spl. Independentei 202, Bucharest (Romania); Perisanu, Stefan T., E-mail: stefan.perisanu@upb.ro [Laboratory of General Chemistry, Polytechnic University of Bucharest, str. Polizu nr. 1, Bucuresti (Romania)

2010-01-10

The energies of combustion of L-asparagine and L-{alpha}-glutamine were measured in a static bomb adiabatic calorimeter. Corrections were made for the heats due to the ignition of sample and for the nitric acid formation. The derived enthalpies of formation in solid state of asparagine monohydrate, nonhydrated asparagine and glutamine are respectively -1084.1 {+-} 3.0, -788.1 {+-} 4.7 and -834.3 {+-} 4.6 kJ mol{sup -1}. The data of enthalpy of formation are compared with the literature values and with estimated values by means of group additivity, using parameters recommended by Domalski and Hearing. The discrepancies between experimental and calculated values are explained by considering the number and strength of intermolecular hydrogen bonds. The dehydration of asparagine monohydrate and the possible melting of the three amino acids were investigated by means of DSC. Glutamine melts without considerable decomposition at about 182 {sup o}C, while asparagines decompose during the fusion process (208 {sup o}C).

Glutamine deprivation enhances antitumor activity of 3-bromopyruvate through the stabilization of monocarboxylate transporter-1.

Science.gov (United States)

Cardaci, Simone; Rizza, Salvatore; Filomeni, Giuseppe; Bernardini, Roberta; Bertocchi, Fabio; Mattei, Maurizio; Paci, Maurizio; Rotilio, Giuseppe; Ciriolo, Maria Rosa

2012-09-01

Anticancer drug efficacy might be leveraged by strategies to target certain biochemical adaptations of tumors. Here we show how depriving cancer cells of glutamine can enhance the anticancer properties of 3-bromopyruvate, a halogenated analog of pyruvic acid. Glutamine deprival potentiated 3-bromopyruvate chemotherapy by increasing the stability of the monocarboxylate transporter-1, an effect that sensitized cells to metabolic oxidative stress and autophagic cell death. We further elucidated mechanisms through which resistance to chemopotentiation by glutamine deprival could be circumvented. Overall, our findings offer a preclinical proof-of-concept for how to employ 3-bromopyruvate or other monocarboxylic-based drugs to sensitize tumors to chemotherapy. ©2012 AACR.

Glutamine-enriched enteral diet increases renal arginine production

NARCIS (Netherlands)

Houdijk, A. P.; van Leeuwen, P. A.; Teerlink, T.; FLINKERBUSCH, E. L.; Boermeester, M. A.; Sauerwein, H. P.; Wesdorp, R. I.

1994-01-01

Arginine (Arg) is generated in the kidney by the conversion of circulating citrulline. The most important source for circulating citrulline is the metabolism of glutamine (Gln) by the gut. In this study, we investigated the influence of an enteral diet enriched with Gln on renal Arg synthesis in the

The impact of use of Glutamine on patients with head and neck tumors in radiotherapy and chemotherapy treatment

International Nuclear Information System (INIS)

Boligon, Caroline Schardong; Huth, Adriane

2011-01-01

Introduction: patients with head and neck neoplasia usually show malnutrition or a nutritional risk, because of common symptoms like: dysphagia, odynophagia and xerostomia. Objective: this study aimed to verify the impact of using amino glutamine in patients with head and neck neoplasia and under radiotherapy and chemotherapy treatment concomitantly. Methods: the research was quantitative, cross-sectional, descriptive and exploratory. The data was collected from nutritional evaluation, and patients chart consultation. The patients were divided in a control group (without use of glutamine) and a test group (with use of glutamine). 16 patients, 13 of which were men and three were women, participated in the research. Results: The control group presented mucositis grades I to IV while patients who used the amino glutamine showed mucositis grades I to II only. It could be observed that the Nutritional Risk Index decreased, which represents higher nutritional risk in patients from the control group only. In patients who used glutamine, this decrease was not significant. Conclusion: these results suggest that the use of glutamine in patients with head and neck tumors and under antineoplastic therapy helps to maintain their nutritional stage and to prevent mucositis throughout their treatment, mainly grades III and IV, which prevents adequate and regular eating and nourishment. (author)

Reduced brain glutamine in female varsity rugby athletes after concussion and in non-concussed athletes after a season of play.

Science.gov (United States)

Schranz, Amy L; Manning, Kathryn Y; Dekaban, Gregory A; Fischer, Lisa; Jevremovic, Tatiana; Blackney, Kevin; Barreira, Christy; Doherty, Timothy J; Fraser, Douglas D; Brown, Arthur; Holmes, Jeff; Menon, Ravi S; Bartha, Robert

2018-04-01

The purpose of this study was to use non-invasive proton magnetic resonance spectroscopy (MRS) and diffusion tensor imaging (DTI) to monitor changes in prefrontal white matter metabolite levels and tissue microstructure in female rugby players with and without concussion (ages 18-23, n = 64). Evaluations including clinical tests and 3 T MRI were performed at the beginning of a season (in-season) and followed up at the end of the season (off-season). Concussed athletes were additionally evaluated 24-72 hr (n = 14), three months (n = 11), and six months (n = 8) post-concussion. Reduced glutamine at 24-72 hr and three months post-concussion, and reduced glutamine/creatine at three months post-concussion were observed. In non-concussed athletes (n = 46) both glutamine and glutamine/creatine were lower in the off-season compared to in-season. Within the MRS voxel, an increase in fractional anisotropy (FA) and decrease in radial diffusivity (RD) were also observed in the non-concussed athletes, and correlated with changes in glutamine and glutamine/creatine. Decreases in glutamine and glutamine/creatine suggest reduced oxidative metabolism. Changes in FA and RD may indicate neuroinflammation or re-myelination. The observed changes did not correlate with clinical test scores suggesting these imaging metrics may be more sensitive to brain injury and could aid in assessing recovery of brain injury from concussion. © 2017 Wiley Periodicals, Inc.

Supplementation with a combination of beta-hydroxy-beta-methylbutyrate (HMB), arginine, and glutamine is safe and could improve hematological parameters.

Science.gov (United States)

Rathmacher, J A; Nissen, S; Panton, L; Clark, R H; Eubanks May, P; Barber, A E; D'Olimpio, J; Abumrad, N N

2004-01-01

Combining the amino acids arginine and glutamine with the leucine metabolite beta-hydroxy-beta-methylbutyrate (HMB) has been shown to reverse lean tissue loss in cancer and acquired immunodeficiency syndrome (AIDS) patients. Although each of these nutrients has been shown to be safe, the safety of this mixture has not been reported. Three double-blind studies examined the safety of the combination of HMB, arginine and glutamine on blood chemistries, hematology, emotional profile, and adverse events. Study 1 was conducted in healthy adult males (n = 34), study 2 was in HIV patients with AIDS-associated weight loss (n = 43), and study 3 was in cancer patients with wasting (n = 32). Volunteers were assigned to either a placebo or a mixture of 3 g HMB, 14 g arginine, and 14 g glutamine per day. Across the 3 studies, HMB, arginine, and glutamine supplementation was not associated with any adverse indicators of health. The only significant changes noted were positive indicators of health status. HMB, arginine, and glutamine supplementation was associated with an improvement in emotional profile (p = .05), a decreased feeling of weakness (p = .03), and increased red blood cells, hemoglobin, hematocrit, lymphocytes, and eosinophils (p HMB, arginine, and glutamine supplementation, which was possibly caused by the additional nitrogen consumed or to the fact that ureagenesis is influenced by arginine and glutamine supplementation. These results show that HMB, arginine, and glutamine can be safely used to treat muscle wasting associated with AIDS and cancer.

The effect of glutamine infusion on the inflammatory response and HSP70 during human experimental endotoxaemia

DEFF Research Database (Denmark)

Andreasen, Anne Sofie; Pedersen-Skovsgaard, Theis; Mortensen, Ole Hartvig

2009-01-01

was associated with alterations in white blood cell and differential counts, tumour necrosis factor-alpha, IL-6, temperature and heart rate, but glutamine affected neither the endotoxin-induced change in these variables nor the expression of HSP70 in BMNCs. CONCLUSIONS: Endotoxin reduced plasma glutamine...

The structures of cytosolic and plastid-located glutamine synthetases from Medicago truncatula reveal a common and dynamic architecture

International Nuclear Information System (INIS)

Torreira, Eva; Seabra, Ana Rita; Marriott, Hazel; Zhou, Min; Llorca, Óscar; Robinson, Carol V.; Carvalho, Helena G.; Fernández-Tornero, Carlos; Pereira, Pedro José Barbosa

2014-01-01

The experimental models of dicotyledonous cytoplasmic and plastid-located glutamine synthetases unveil a conserved eukaryotic-type decameric architecture, with subtle structural differences in M. truncatula isoenzymes that account for their distinct herbicide resistance. The first step of nitrogen assimilation in higher plants, the energy-driven incorporation of ammonia into glutamate, is catalyzed by glutamine synthetase. This central process yields the readily metabolizable glutamine, which in turn is at the basis of all subsequent biosynthesis of nitrogenous compounds. The essential role performed by glutamine synthetase makes it a prime target for herbicidal compounds, but also a suitable intervention point for the improvement of crop yields. Although the majority of crop plants are dicotyledonous, little is known about the structural organization of glutamine synthetase in these organisms and about the functional differences between the different isoforms. Here, the structural characterization of two glutamine synthetase isoforms from the model legume Medicago truncatula is reported: the crystallographic structure of cytoplasmic GSII-1a and an electron cryomicroscopy reconstruction of plastid-located GSII-2a. Together, these structural models unveil a decameric organization of dicotyledonous glutamine synthetase, with two pentameric rings weakly connected by inter-ring loops. Moreover, rearrangement of these dynamic loops changes the relative orientation of the rings, suggesting a zipper-like mechanism for their assembly into a decameric enzyme. Finally, the atomic structure of M. truncatula GSII-1a provides important insights into the structural determinants of herbicide resistance in this family of enzymes, opening new avenues for the development of herbicide-resistant plants

The structures of cytosolic and plastid-located glutamine synthetases from Medicago truncatula reveal a common and dynamic architecture

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Torreira, Eva [Centro de Investigaciones Biológicas – CSIC, Ramiro de Maeztu 9, 28040 Madrid (Spain); Seabra, Ana Rita [IBMC – Instituto de Biologia Molecular e Celular, Universidade do Porto, Rua do Campo Alegre 823, 4150-180 Porto (Portugal); Marriott, Hazel; Zhou, Min [University of Oxford, South Parks Road, Oxford OX1 3QZ (United Kingdom); Llorca, Óscar [Centro de Investigaciones Biológicas – CSIC, Ramiro de Maeztu 9, 28040 Madrid (Spain); Robinson, Carol V. [University of Oxford, South Parks Road, Oxford OX1 3QZ (United Kingdom); Carvalho, Helena G. [IBMC – Instituto de Biologia Molecular e Celular, Universidade do Porto, Rua do Campo Alegre 823, 4150-180 Porto (Portugal); Fernández-Tornero, Carlos, E-mail: cftornero@cib.csic.es [Centro de Investigaciones Biológicas – CSIC, Ramiro de Maeztu 9, 28040 Madrid (Spain); Pereira, Pedro José Barbosa, E-mail: cftornero@cib.csic.es [IBMC – Instituto de Biologia Molecular e Celular, Universidade do Porto, Rua do Campo Alegre 823, 4150-180 Porto (Portugal); Centro de Investigaciones Biológicas – CSIC, Ramiro de Maeztu 9, 28040 Madrid (Spain)

2014-04-01

The experimental models of dicotyledonous cytoplasmic and plastid-located glutamine synthetases unveil a conserved eukaryotic-type decameric architecture, with subtle structural differences in M. truncatula isoenzymes that account for their distinct herbicide resistance. The first step of nitrogen assimilation in higher plants, the energy-driven incorporation of ammonia into glutamate, is catalyzed by glutamine synthetase. This central process yields the readily metabolizable glutamine, which in turn is at the basis of all subsequent biosynthesis of nitrogenous compounds. The essential role performed by glutamine synthetase makes it a prime target for herbicidal compounds, but also a suitable intervention point for the improvement of crop yields. Although the majority of crop plants are dicotyledonous, little is known about the structural organization of glutamine synthetase in these organisms and about the functional differences between the different isoforms. Here, the structural characterization of two glutamine synthetase isoforms from the model legume Medicago truncatula is reported: the crystallographic structure of cytoplasmic GSII-1a and an electron cryomicroscopy reconstruction of plastid-located GSII-2a. Together, these structural models unveil a decameric organization of dicotyledonous glutamine synthetase, with two pentameric rings weakly connected by inter-ring loops. Moreover, rearrangement of these dynamic loops changes the relative orientation of the rings, suggesting a zipper-like mechanism for their assembly into a decameric enzyme. Finally, the atomic structure of M. truncatula GSII-1a provides important insights into the structural determinants of herbicide resistance in this family of enzymes, opening new avenues for the development of herbicide-resistant plants.

Effects of Glutamine on Gastric Emptying of Low- and High-Nutrient Drinks in Healthy Young Subjects—Impact on Glycaemia

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Yang T. Du

2018-06-01

Full Text Available Glutamine is a potent stimulus for the release of glucagon-like peptide-1, which increases postprandial insulin and slows gastric emptying (GE. We determined the effects of glutamine on GE of, and glycaemic responses to, low- and high-nutrient drinks in eight healthy males (mean age 21.6 ± 0.7 years and BMI 22.9 ± 0.7 kg/m2. Participants were studied on four occasions on which they consumed either a low-nutrient (beef soup; 18 kcal or high-nutrient (75 g dextrose; 255 kcal drink, each with or without 30 g of glutamine (120 kcal, in a randomised, crossover design. GE (2D ultrasound, blood glucose and plasma insulin concentrations were measured concurrently. Glutamine slowed GE (half emptying time (T50 of both low- (45 ± 3 min vs. 26 ± 2 min, p < 0.001, and high-nutrient, (100 ± 5 min vs. 77 ± 5 min, p = 0.03 drinks, however, there was no effect on GE of the high nutrient drinks when expressed as kcal/min (3.39 ± 0.21 kcal/min vs. 3.81 ± 0.20 kcal/min, p = 0.25. There was no change in blood glucose after the low-nutrient drinks with or without glutamine, despite a slight increase in plasma insulin with glutamine (p = 0.007. The rise in blood glucose following the high-nutrient drink (p = 0.0001 was attenuated during the first 60 min by glutamine (p = 0.007. We conclude that in healthy subjects, glutamine slows GE of both low- and high-nutrient drinks comparably and attenuates the rise in blood glucose after the high-nutrient glucose drink.

Differential inhibition of adenylylated and deadenylylated forms of M. tuberculosis glutamine synthetase as a drug discovery platform

CSIR Research Space (South Africa)

Theron, Anjo

2017-10-01

Full Text Available mechanism, so the adenylylated form of bacterial glutamine synthetase is of particular interest. Previously published reports show that, when M. tuberculosis glutamine synthetase is expressed in Escherichia coli, the E. coli adenylyl transferase does...

Perioperative Alanyl-Glutamine-Supplemented Parenteral Nutrition in Chronic Radiation Enteritis Patients With Surgical Intestinal Obstruction: A Prospective, Randomized, Controlled Study.

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Yao, Danhua; Zheng, Lei; Wang, Jian; Guo, Mingxiao; Yin, Jianyi; Li, Yousheng

2016-04-01

A prospective, randomized, controlled study was performed to evaluate the effects of perioperative alanyl-glutamine-supplemented parenteral nutrition (PN) support on the immunologic function, intestinal permeability, and nutrition status of surgical patients with chronic radiation enteritis (CRE)-induced intestinal obstruction. Patients who received 0.4 g/kg/d alanyl-glutamine and isonitrogenous PN were assigned to an alanyl-glutamine-supplemented PN (Gln-PN) group and a control group, respectively. Serum levels of alanine aminotransferase and glutamine, body fat mass (FM), immunologic function, and intestinal permeability were measured before and after surgery. Serum glutamine levels of the Gln-PN group significantly exceeded that of the control group (P nutrition state and intestinal motility of surgical patients with CRE-induced intestinal obstruction. © 2015 American Society for Parenteral and Enteral Nutrition.

Effects of L-glutamine supplementation on the myenteric neurons from the duodenum and cecum of diabetic rats

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Jacqueline Nelisis Zanoni

2011-03-01

Full Text Available CONTEXT: Peripheral neuropathy is one of the chronic complications of diabetes mellitus and is directly related to gastrointestinal consequences of the disease. Myenteric neurons are affected in some pathological conditions such as diabetic neuropathy. The imbalance between cellular antioxidants and free radicals, leading to an increase in oxidative stress, is considered one of the main factors responsible for neuronal damages in diabetes. Drugs that reduce the oxidative stress may play a significant role in the treatment of neurological complications of diabetes mellitus. OBJECTIVE: To evaluate the effect of L-glutamine supplementation on the myenteric neurons from the cecum and duodenum of Wistar rats with streptozotocin-induced diabetes mellitus. METHODS: The animals were divided in four groups (n = 5: non-treated normoglycemics, normoglycemics treated with L-glutamine, non-treated diabetics and diabetics treated with L-glutamine from the 4th day of diabetes induction on. The amino acid L-glutamine was added to their diet at 1%. Giemsa's technique was employed to stain the myenteric neurons. We determined the cell body area of 500 neurons in each group studied. The quantitative analysis was performed by sampling in an area of 16.6 mm² in the cecum and 3.6 mm² in the duodenum of each animal. RESULTS: After the supplementation with L-glutamine in the duodenum, we observed a preservation of neuronal density in groups normoglycemic and diabetic (P<0.05. We also observed a preservation of the cell bodies area in diabetic animals (group treated with L-glutamine (P<0.05. In the cecum, that preservation was not evident. CONCLUSION: Supplementation with L-glutamine (1% promoted a neuroprotective effect on the myenteric neurons from the duodenum of rats, both in terms of natural aging and of diabetes mellitus.

Glutamine-derived 2-hydroxyglutarate is associated with disease progression in plasma cell malignancies

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Gonsalves, Wilson I.; Hitosugi, Taro; Ghosh, Toshi; Jevremovic, Dragan; Petterson, Xuan-Mai; Wellik, Linda; Kumar, Shaji K.; Nair, K. Sreekumaran

2018-01-01

The production of the oncometabolite 2-hydroxyglutarate (2-HG) has been associated with c-MYC overexpression. c-MYC also regulates glutamine metabolism and drives progression of asymptomatic precursor plasma cell (PC) malignancies to symptomatic multiple myeloma (MM). However, the presence of 2-HG and its clinical significance in PC malignancies is unknown. By performing 13C stable isotope resolved metabolomics (SIRM) using U[13C6]Glucose and U[13C5]Glutamine in human myeloma cell lines (HMCLs), we show that 2-HG is produced in clonal PCs and is derived predominantly from glutamine anaplerosis into the TCA cycle. Furthermore, the 13C SIRM studies in HMCLs also demonstrate that glutamine is preferentially utilized by the TCA cycle compared with glucose. Finally, measuring the levels of 2-HG in the BM supernatant and peripheral blood plasma from patients with precursor PC malignancies such as smoldering MM (SMM) demonstrates that relatively elevated levels of 2-HG are associated with higher levels of c-MYC expression in the BM clonal PCs and with a subsequent shorter time to progression (TTP) to MM. Thus, measuring 2-HG levels in BM supernatant or peripheral blood plasma of SMM patients offers potential early identification of those patients at high risk of progression to MM, who could benefit from early therapeutic intervention. PMID:29321378

Synthesis of Biobased Succinonitrile from Glutamic Acid and Glutamine

NARCIS (Netherlands)

Lammens, T.M.; Nôtre, Le J.; Franssen, M.C.R.; Scott, E.L.; Sanders, J.P.M.

2011-01-01

Succinonitrile is the precursor of 1,4-diaminobutane, which is used for the industrial production of polyamides. This paper describes the synthesis of biobased succinonitrile from glutamic acid and glutamine, amino acids that are abundantly present in many plant proteins. Synthesis of the

Monoclonal antibody heterogeneity analysis and deamidation monitoring with high-performance cation-exchange chromatofocusing using simple, two component buffer systems.

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Kang, Xuezhen; Kutzko, Joseph P; Hayes, Michael L; Frey, Douglas D

2013-03-29

The use of either a polyampholyte buffer or a simple buffer system for the high-performance cation-exchange chromatofocusing of monoclonal antibodies is demonstrated for the case where the pH gradient is produced entirely inside the column and with no external mixing of buffers. The simple buffer system used was composed of two buffering species, one which becomes adsorbed onto the column packing and one which does not adsorb, together with an adsorbed ion that does not participate in acid-base equilibrium. The method which employs the simple buffer system is capable of producing a gradual pH gradient in the neutral to acidic pH range that can be adjusted by proper selection of the starting and ending pH values for the gradient as well as the buffering species concentration, pKa, and molecular size. By using this approach, variants of representative monoclonal antibodies with isoelectric points of 7.0 or less were separated with high resolution so that the approach can serve as a complementary alternative to isoelectric focusing for characterizing a monoclonal antibody based on differences in the isoelectric points of the variants present. Because the simple buffer system used eliminates the use of polyampholytes, the method is suitable for antibody heterogeneity analysis coupled with mass spectrometry. The method can also be used at the preparative scale to collect highly purified isoelectric variants of an antibody for further study. To illustrate this, a single isoelectric point variant of a monoclonal antibody was collected and used for a stability study under forced deamidation conditions. Copyright © 2013 Elsevier B.V. All rights reserved.

Physiological hypercortisolemia increases proteolysis, glutamine, and alanine production

International Nuclear Information System (INIS)

Darmaun, D.; Matthews, D.E.; Bier, D.M.

1988-01-01

Physiological elevations of plasma cortisol levels, as are encountered in stress and severe trauma, were produced in six normal subjects by infusing them with hydrocortisone for 64 h. Amino acid kinetics were measured in the postabsorptive state using three 4-h infusions of L-[1- 13 C]leucine, L-phenyl[ 2 H 5 ]phenylalanine, L-[2- 15 N]glutamine, and L-[1- 13 C]alanine tracers (1) before, (2) at 12 h, and (3) at 60 h of cortisol infusion. Before and throughout the study, the subjects ate a normal diet of adequate protein and energy intake. The cortisol infusion raised plasma cortisol levels significantly from 10 ± 1 to 32 ± 4 μg/dl, leucine flux from 83 ± 3 to 97 ± 3 μmol·kg -1 ·h -1 , and phenylalanine flux from 34 ± 1 to 39 ± 1 (SE) μmol·kg -1 ·h -1 after 12 h of cortisol infusion. These increases were maintained until the cortisol infusion was terminated. These nearly identical 15% increases in two different essential amino acid appearance rates are reflective of increased whole body protein breakdown. Glutamine flux rose by 12 h of cortisol infusion and remained elevated at the same level at 64 h. The increase in flux was primarily due to a 55% increase in glutamine de novo synthesis. Alanine flux increased with acute hypercortisolemia and increased further at 60 h of cortisol infusion, a result primarily of increased alanine de novo synthesis. Insulin, alanine, and lactate plasma levels responded similarly with significant rises between the acute and chronic periods of cortisol infusion. Thus hypercortisolemia increases both protein breakdown and the turnover of important nonessential amino acids for periods of up to 64 h

Effect of carbohydrate supplementation on plasma glutamine during prolonged exercise and recovery

DEFF Research Database (Denmark)

Van Hall, Gerrit; Saris, W H; Wagenmakers, A J

1998-01-01

. Eight well-trained subjects cycled at an alternating workload of 50 and 80% Wmax until exhaustion (59 to 140 min). During the exercise bout the subjects received either water (control) or a carbohydrate (CHO) drink (83 g CHO x l(-1), 2 ml x kg(-1) per kg body weight every 15 min). Plasma glutamine......%) decreased below the pre-exercise level. The plasma alanine and the total amino acid concentration was still suppressed after 7 h of recovery. In conclusion, carbohydrate supplementation had neither an effect during exercise nor during recovery on the concentration of plasma glutamine or other amino acids...

Regional tumour glutamine supply affects chromatin and cell identity

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Højfeldt, Jonas W; Helin, Kristian

2016-01-01

Limited perfusion of solid tumours produces a nutrient-deprived tumour core microenvironment. Low glutamine levels in the tumour core are now shown to lead to reduced levels of α-ketoglutarate and decreased histone demethylase activity, thereby promoting a less differentiated and more therapy-res...

Impaired Hippocampal Glutamate and Glutamine Metabolism in the db/db Mouse Model of Type 2 Diabetes Mellitus

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Andersen, Jens Velde; Nissen, Jakob Dahl; Christensen, Sofie Kjellerup

2017-01-01

Type 2 diabetes mellitus (T2DM) is a risk factor for the development of Alzheimer's disease, and changes in brain energy metabolism have been suggested as a causative mechanism. The aim of this study was to investigate the cerebral metabolism of the important amino acids glutamate and glutamine...... significantly reduced 13C labeling in glutamate, glutamine, GABA, citrate, and aspartate from metabolism of [U-13C]glutamate. Additionally, reduced 13C labeling were observed in GABA, citrate, and aspartate from [U-13C]glutamine metabolism in hippocampal slices of db/db mice when compared to controls. None...

Structure of the Dispase Autolysis-inducing Protein from Streptomyces mobaraensis and Glutamine Cross-linking Sites for Transglutaminase.

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Fiebig, David; Schmelz, Stefan; Zindel, Stephan; Ehret, Vera; Beck, Jan; Ebenig, Aileen; Ehret, Marina; Fröls, Sabrina; Pfeifer, Felicitas; Kolmar, Harald; Fuchsbauer, Hans-Lothar; Scrima, Andrea

2016-09-23

Transglutaminase from Streptomyces mobaraensis (MTG) is an important enzyme for cross-linking and modifying proteins. An intrinsic substrate of MTG is the dispase autolysis-inducing protein (DAIP). The amino acid sequence of DAIP contains 5 potential glutamines and 10 lysines for MTG-mediated cross-linking. The aim of the study was to determine the structure and glutamine cross-linking sites of the first physiological MTG substrate. A production procedure was established in Escherichia coli BL21 (DE3) to obtain high yields of recombinant DAIP. DAIP variants were prepared by replacing four of five glutamines for asparagines in various combinations via site-directed mutagenesis. Incorporation of biotin cadaverine revealed a preference of MTG for the DAIP glutamines in the order of Gln-39 ≫ Gln-298 > Gln-345 ∼ Gln-65 ≫ Gln-144. In the structure of DAIP the preferred glutamines do cluster at the top of the seven-bladed β-propeller. This suggests a targeted cross-linking of DAIP by MTG that may occur after self-assembly in the bacterial cell wall. Based on our biochemical and structural data of the first physiological MTG substrate, we further provide novel insight into determinants of MTG-mediated modification, specificity, and efficiency. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Alanyl-glutamine dipeptide restores the cytoprotective stress proteome of mesothelial cells exposed to peritoneal dialysis fluids.

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Kratochwill, Klaus; Boehm, Michael; Herzog, Rebecca; Lichtenauer, Anton Michael; Salzer, Elisabeth; Lechner, Michael; Kuster, Lilian; Bergmeister, Konstantin; Rizzi, Andreas; Mayer, Bernd; Aufricht, Christoph

2012-03-01

Exposure of mesothelial cells to peritoneal dialysis fluids (PDF) results in cytoprotective cellular stress responses (CSR) that counteract PDF-induced damage. In this study, we tested the hypothesis that the CSR may be inadequate in relevant models of peritoneal dialysis (PD) due to insufficient levels of glutamine, resulting in increased vulnerability against PDF cytotoxicity. We particularly investigated the role of alanyl-glutamine (Ala-Gln) dipeptide on the cytoprotective PDF stress proteome. Adequacy of CSR was investigated in two human in vitro models (immortalized cell line MeT-5A and mesothelial cells derived from peritoneal effluent of uraemic patients) following exposure to heat-sterilized glucose-based PDF (PD4-Dianeal, Baxter) diluted with medium and, in a comparative proteomics approach, at different levels of glutamine ranging from depletion (0 mM) via physiological (0.7 mM) to pharmacological levels (8 mM administered as Ala-Gln). Despite severe cellular injury, expression of cytoprotective proteins was dampened upon PDF exposure at physiological glutamine levels, indicating an inadequate CSR. Depletion of glutamine aggravated cell injury and further reduced the CSR, whereas addition of Ala-Gln at pharmacological level restored an adequate CSR, decreasing cellular damage in both PDF exposure systems. Ala-Gln specifically stimulated chaperoning activity, and cytoprotective processes were markedly enhanced in the PDF stress proteome. Taken together, this study demonstrates an inadequate CSR of mesothelial cells following PDF exposure associated with low and physiological levels of glutamine, indicating a new and potentially relevant pathomechanism. Supplementation of PDF with pharmacological doses of Ala-Gln restored the cytoprotective stress proteome, resulting in improved resistance of mesothelial cells to exposure to PDF. Future work will study the clinical relevance of CSR-mediated cytoprotection.

Effects of L-glutamine supplementation on maternal and fetal hemodynamics in gestating ewes exposed to alcohol.

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Sawant, Onkar B; Ramadoss, Jayanth; Hankins, Gary D; Wu, Guoyao; Washburn, Shannon E

2014-08-01

Not much is known about effects of gestational alcohol exposure on maternal and fetal cardiovascular adaptations. This study determined whether maternal binge alcohol exposure and L-glutamine supplementation could affect maternal-fetal hemodynamics and fetal regional brain blood flow during the brain growth spurt period. Pregnant sheep were randomly assigned to one of four groups: saline control, alcohol (1.75-2.5 g/kg body weight), glutamine (100 mg/kg body weight) or alcohol + glutamine. A chronic weekend binge drinking paradigm between gestational days (GD) 99 and 115 was utilized. Fetuses were surgically instrumented on GD 117 ± 1 and studied on GD 120 ± 1. Binge alcohol exposure caused maternal acidemia, hypercapnea, and hypoxemia. Fetuses were acidemic and hypercapnic, but not hypoxemic. Alcohol exposure increased fetal mean arterial pressure, whereas fetal heart rate was unaltered. Alcohol exposure resulted in ~40 % reduction in maternal uterine artery blood flow. Labeled microsphere analyses showed that alcohol induced >2-fold increases in fetal whole brain blood flow. The elevation in fetal brain blood flow was region-specific, particularly affecting the developing cerebellum, brain stem, and olfactory bulb. Maternal L-glutamine supplementation attenuated alcohol-induced maternal hypercapnea, fetal acidemia and increases in fetal brain blood flow. L-Glutamine supplementation did not affect uterine blood flow. Collectively, alcohol exposure alters maternal and fetal acid-base balance, decreases uterine blood flow, and alters fetal regional brain blood flow. Importantly, L-glutamine supplementation mitigates alcohol-induced acid-base imbalances and alterations in fetal regional brain blood flow. Further studies are warranted to elucidate mechanisms responsible for alcohol-induced programming of maternal uterine artery and fetal circulation adaptations in pregnancy.

Effects of honey, glutamine and their combination on canine small ...

African Journals Online (AJOL)

olayemitoyin

and adaptation, evidenced by increased in residual bowel Villi height (27.71µm), ... advantage over glutamine or honey and may be a preferred treatment for short bowel syndrome patients. .... good general health based on complete clinical.

Glutamine-dependent carbamoyl-phosphate synthetase and other enzyme activities related to the pyrimidine pathway in spleen of Squalus acanthias (spiny dogfish).

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Anderson, P M

1989-01-01

The first two steps of urea synthesis in liver of marine elasmobranchs involve formation of glutamine from ammonia and of carbamoyl phosphate from glutamine, catalysed by glutamine synthetase and carbamoyl-phosphate synthetase, respectively [Anderson & Casey (1984) J. Biol. Chem. 259, 456-462]; both of these enzymes are localized exclusively in the mitochondrial matrix. The objective of this study was to establish the enzymology of carbamoyl phosphate formation and utilization for pyrimidine nucleotide biosynthesis in Squalus acanthias (spiny dogfish), a representative elasmobranch. Aspartate carbamoyltransferase could not be detected in liver of dogfish. Spleen extracts, however, had glutamine-dependent carbamoyl-phosphate synthetase, aspartate carbamoyltransferase, dihydro-orotase, and glutamine synthetase activities, all localized in the cytosol; dihydro-orotate dehydrogenase, orotate phosphoribosyltransferase, and orotidine-5'-decarboxylase activities were also present. Except for glutamine synthetase, the levels of all activities were very low. The carbamoyl-phosphate synthetase activity is inhibited by UTP and is activated by 5-phosphoribosyl 1-pyrophosphate. The first three enzyme activities of the pyrimidine pathway were eluted in distinctly different positions during gel filtration chromatography under a number of different conditions; although complete proteolysis of inter-domain regions of a multifunctional complex during extraction cannot be excluded, the evidence suggests that in dogfish, in contrast to mammalian species, these three enzymes of the pyrimidine pathway exist as individual polypeptide chains. These results: (1) establish that dogfish express two different glutamine-dependent carbamoyl-phosphate synthetase activities, (2) confirm the report [Smith, Ritter & Campbell (1987) J. Biol. Chem. 262, 198-202] that dogfish express two different glutamine synthetases, and (3) provide indirect evidence that glutamine may not be available in liver for

Exogenous glutamine increases lipid accumulation in developing seeds of castor bean (Ricinus communis L. cultured in vitro

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Zhang Yang

2015-01-01

Full Text Available This report describes biomass production and compositional changes of developing castor seeds in response to change in the nitrogen resource (glutamine of the medium. During the early developmental period (24-36 days after pollination, oil was found to initially accumulate in the developing seeds. Carbohydrates and oil were inversely related after glutamine provision (35 mM, in the culture medium. [U-14C] sucrose labeling was used to investigate the effect of metabolic fluxes among different storage materials. Addition of glutamine led to a 7% increase of labeling in lipids and an inverse decrease of labeling in carbohydrates. It was postulated that changes in the glutamine concentration in the medium are likely to influence the partitioning of resources between the various storage products, especially carbohydrates and oil. These observations will contribute to a better understanding of assimilate partitioning in developing castor seeds and the development of molecular strategies to improve castor bean seed quality and plant breeding studies.

Effects of adding different levels of Glutamine to modified Beltsville extender on the survival of frozen rooster semen.

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Khiabani, Aytak Bakhshayesh; Moghaddam, Gholamali; Kia, Hossein Daghigh

2017-09-01

The aim of the present study was to investigate the effects of l-glutamine on the quality of frozen-thawed rooster semen. Semen samples were collected from eight mature roosters (Ross 308). After initial semen assessments, samples of adequate quality were mixed together and diluted with modified Beltsville extender without l-glutamine (control) and supplemented with 2.5, 5, and 7.5mM l-glutamine. Semen straws were subjected to cryopreservation and evaluated twice at 15-day intervals. After thawing, sperm viability, total and progressive sperm motilities were measured by Eosin-Nigrosine and Computer-Aided Sperm Analysis (CASA), respectively. The results showed that sperm functions decreased on day 30 compared to day 15. The extender supplemented with 5mM glutamine improved (prooster sperm to be frozen for longer. Copyright © 2017 Elsevier B.V. All rights reserved.

Phage display selection of efficient glutamine-donor substrate peptides for transglutaminase 2.

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Keresztessy, Zsolt; Csosz, Eva; Hársfalvi, Jolán; Csomós, Krisztián; Gray, Joe; Lightowlers, Robert N; Lakey, Jeremy H; Balajthy, Zoltán; Fésüs, László

2006-11-01

Understanding substrate specificity and identification of natural targets of transglutaminase 2 (TG2), the ubiquitous multifunctional cross-linking enzyme, which forms isopeptide bonds between protein-linked glutamine and lysine residues, is crucial in the elucidation of its physiological role. As a novel means of specificity analysis, we adapted the phage display technique to select glutamine-donor substrates from a random heptapeptide library via binding to recombinant TG2 and elution with a synthetic amine-donor substrate. Twenty-six Gln-containing sequences from the second and third biopanning rounds were susceptible for TG2-mediated incorporation of 5-(biotinamido)penthylamine, and the peptides GQQQTPY, GLQQASV, and WQTPMNS were modified most efficiently. A consensus around glutamines was established as pQX(P,T,S)l, which is consistent with identified substrates listed in the TRANSDAB database. Database searches showed that several proteins contain peptides similar to the phage-selected sequences, and the N-terminal glutamine-rich domain of SWI1/SNF1-related chromatin remodeling proteins was chosen for detailed analysis. MALDI/TOF and tandem mass spectrometry-based studies of a representative part of the domain, SGYGQQGQTPYYNQQSPHPQQQQPPYS (SnQ1), revealed that Q(6), Q(8), and Q(22) are modified by TG2. Kinetic parameters of SnQ1 transamidation (K(M)(app) = 250 microM, k(cat) = 18.3 sec(-1), and k(cat)/K(M)(app) = 73,200) classify it as an efficient TG2 substrate. Circular dichroism spectra indicated that SnQ1 has a random coil conformation, supporting its accessibility in the full-length parental protein. Added together, here we report a novel use of the phage display technology with great potential in transglutaminase research.

Combined Effects of Tauroursodeoxycholic Acid and Glutamine on Bacterial Translocation in Obstructive Jaundiced Rats

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Ahmet Rahmi Hatipoğlu

2013-12-01

Full Text Available Background: Bacterial Translocation is believed to be an important factor on mortality and morbidity in Obstructive Jaundiced. Aims: We investigated the probable or estimated positive effects of tauroursodeoxycholic acid, which has antibacterial and regulatory effects on intestinal flora, together with glutamine on BT in an experimental obstructive jaundiced rat model. Study Design: Animal experimentation. Methods: Forty adult, male, Sprague Dawley rats were used in this study. Animals were randomised and divided into five groups of eight each: sham (Sh; control (common bile duct ligation, CBDL; and supplementation groups administered tauroursodeoxycholic acid (CBDL+T, glutamine (CBDL+G, or tauroursodeoxycholic acid plus glutamine (CBDL+TG. Blood and liver, spleen, MLN, and ileal samples were taken via laparotomy under sterile conditions for investigation of bacterial translocation and intestinal mucosal integrity and hepatic function tests on the tenth postoperative day. Results: There were statistically significant differences in BT rates in all samples except the spleen of the CBDL+TG group compared with the CBDL group (p=0.041, p=0.026, and p=0.041, respectively. Conclusion: It is essential to protect hepatic functions besides maintaining intestinal mucosal integrity in the active struggle against BT occurring in obstructive jaundice. The positive effect on intestinal mucosal integrity can be increased if glutamine is used with tauroursodeoxycholic acid, which also has hepatoprotective and immunomodulatory features.

Some amino acids levels: glutamine,glutamate, and homocysteine, in plasma of children with chronic kidney disease.

Science.gov (United States)

Fadel, Fatina I; Elshamaa, Manal F; Essam, Rascha G; Elghoroury, Eman A; El-Saeed, Gamila S M; El-Toukhy, Safinaz E; Ibrahim, Mona Hamed

2014-03-01

The high prevalence of protein-energy malnutrition is a critical issue for patients with chronic kidney disease (CKD). Serum albumin is the most commonly used nutritional marker. Another index is plasma amino acid (AA) profile. Of these, the plasma levels of glutamine, glutamate and homocysteine, correlate well with nutritional status. We measured some plasma AAs in children with different stages CKD to provide information in monitoring the therapeutic strategy, particularly in AA supplementary therapy or protein restriction. Three amino acids were evaluated along with albumin and high sensitivity C-reactive protein (hs-CRP) in 30 patients with advanced CKD stages 4 and 5. They were divided into two groups undergoing conservative treatment (CT) (n=15) or hemodialysis (HD) (n=15). An additional group of patients with nephrotic syndrome [CKD stage 2] was also studied to assess the alterations of plasma free amino acids with the early stage of CKD. Another 30 age- and sex-matched healthy children served as controls. A significant increase in plasma concentration of amino acid glutamine was observed in children with advanced CKD stages 4 and 5 when compared with controls (P=0.02).Plasma glutamine level was significantly higher in ESRD children on HD than in children with nephrotic syndrome (P=0.02). We did not find a significant difference between HD children and CT children as regard to glutamine level. Notable differences were in the plasma homocysteine level detected in the CKD groups patients, which was greater than that in controls (P=0.0001). Plasma homocysteine level was significantly higher in children on HD than in children with nephrotic syndrome (P=0.01). A significant differences was observed in hs-CRP levels between the CKD groups and the controls (P=0.04). Albumin levels were lower in CKD groups than in controls (p=0.01). Glutamine showed significant positive correlations with blood urea level (r=0.84, P=0.002) and blood ammonia level (r=0.72, P=0

Quantitative analysis of 15N labeled positional isomers of glutamine and citrulline via electrospray ionization tandem mass spectrometry of their dansyl derivatives

Science.gov (United States)

The enteral metabolism of glutamine and citrulline are intertwined because, while glutamine is one of the main fuel sources for the enterocyte, citrulline is one of its products. It has been shown that the administration of 15N labeled glutamine results in the incorporation of the 15N label into cit...

Quantitative analysis of 15N-labeled positional isomers of glutamine and citrulline via electrospray ionization tandem mass spectrometry of their dansyl derivatives.

Science.gov (United States)

Marini, Juan C

2011-05-15

The enteral metabolisms of glutamine and citrulline are intertwined because, while glutamine is one of the main fuel sources for the enterocyte, citrulline is one of its products. It has been shown that the administration of (15)N-labeled glutamine results in the incorporation of the (15)N label into citrulline, but it is not clear which of the three nitrogen groups of citrulline is actually labeled. To determine the (15)N-enrichment of the positional isomers of glutamine and citrulline, a rapid liquid chromatography/tandem mass spectrometry (LC/MS/MS) method was developed. The amino acids were analyzed as their dansyl derivatives. The product ion resulting from the loss of NH(3) from the omega carbon allows for the determination of the enrichment of the ureido (citrulline) or amido groups (glutamine). The protonated pyrrolidine (citrulline) or 5-oxopyrrolidine (glutamine) product ion contains the 2-N (amino group) and is used to determine its enrichment. The method described showed no ion suppression and a wide dynamic range ranging from 1.3 picomoles to 2 nanomoles for citrulline. Background samples and standards resulted in enrichments not different from those theoretically expected. The enrichment curves for the different glutamine and citrulline isotopomers were linear (R(2)  > 0.998) over the range of enrichments studied. The method developed provides an additional insight into the metabolism of glutamine and citrulline tracing the precursor-product relationship between these two amino acids. Copyright © 2011 John Wiley & Sons, Ltd.

The Separation and Quantitation of Peptides with and without Oxidation of Methionine and Deamidation of Asparagine Using Hydrophilic Interaction Liquid Chromatography with Mass Spectrometry (HILIC-MS)

Science.gov (United States)

Badgett, Majors J.; Boyes, Barry; Orlando, Ron

2017-05-01

Peptides with deamidated asparagine residues and oxidized methionine residues are often not resolved sufficiently to allow quantitation of their native and modified forms using reversed phase (RP) chromatography. The accurate quantitation of these modifications is vital in protein biotherapeutic analysis because they can affect a protein's function, activity, and stability. We demonstrate here that hydrophilic interaction liquid chromatography (HILIC) adequately and predictably separates peptides with these modifications from their native counterparts. Furthermore, coefficients describing the extent of the hydrophilicity of these modifications have been derived and were incorporated into a previously made peptide retention prediction model that is capable of predicting the retention times of peptides with and without these modifications.

Glutamine-Elicited Secretion of Glucagon-Like Peptide 1 Is Governed by an Activated Glutamate Dehydrogenase.

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Andersson, Lotta E; Shcherbina, Liliya; Al-Majdoub, Mahmoud; Vishnu, Neelanjan; Arroyo, Claudia Balderas; Aste Carrara, Jonathan; Wollheim, Claes B; Fex, Malin; Mulder, Hindrik; Wierup, Nils; Spégel, Peter

2018-03-01

Glucagon-like peptide 1 (GLP-1), secreted from intestinal L cells, glucose dependently stimulates insulin secretion from β-cells. This glucose dependence prevents hypoglycemia, rendering GLP-1 analogs a useful and safe treatment modality in type 2 diabetes. Although the amino acid glutamine is a potent elicitor of GLP-1 secretion, the responsible mechanism remains unclear. We investigated how GLP-1 secretion is metabolically coupled in L cells (GLUTag) and in vivo in mice using the insulin-secreting cell line INS-1 832/13 as reference. A membrane-permeable glutamate analog (dimethylglutamate [DMG]), acting downstream of electrogenic transporters, elicited similar alterations in metabolism as glutamine in both cell lines. Both DMG and glutamine alone elicited GLP-1 secretion in GLUTag cells and in vivo, whereas activation of glutamate dehydrogenase (GDH) was required to stimulate insulin secretion from INS-1 832/13 cells. Pharmacological inhibition in vivo of GDH blocked secretion of GLP-1 in response to DMG. In conclusion, our results suggest that nonelectrogenic nutrient uptake and metabolism play an important role in L cell stimulus-secretion coupling. Metabolism of glutamine and related analogs by GDH in the L cell may explain why GLP-1 secretion, but not that of insulin, is activated by these secretagogues in vivo. © 2017 by the American Diabetes Association.

Antioxidant defence of L-glutamine on mitochondrial function in ...

African Journals Online (AJOL)

Myocardial infarction is a major public health concern and the leading cause of death all over the world. A better understanding of the processes involved in myocardial infarction has stimulated the search for biomolecules, which could limit the myocardial injury. We determined the protective activity of L-glutamine on ...

Contribution of extracellular glutamine as an anaplerotic substrate to neuronal metabolism: a re-evaluation by multinuclear NMR spectroscopy in primary cultured neurons.

Science.gov (United States)

Shokati, Touraj; Zwingmann, Claudia; Leibfritz, Dieter

2005-10-01

Multinuclear NMR spectroscopy is used to investigate the effect of glutamine on neuronal glucose metabolism. Primary neurons were incubated with [1-(13C)]glucose in the absence or presence of glutamine (2 mM) and/or NH4Cl (5 mM). After ammonia-treatment, the concentrations of high-energy phosphates decreased up to 84% of control, which was aggravated in glutamine-containing medium (up to 42% of control). These effects could not be attributed to changes in mitochondrial glucose oxidation. Withdrawal of glutamine decreased amino acid concentrations, e.g. of glutamate to 53%, but also considerably lessened the 13C enrichment in [4-(13C)]glutamate to 8.3% of control, and decreased the 13C-enrichment in acetyl-CoA entering the Krebs cycle (P neuronal glutamate stores, glutamate formation is mainly attributed to its de novo synthesis from glucose. Furthermore, mitochondrial glucose metabolism strongly depends on the supply of carbons from glutamine, indicating that exogenous glutamine is a well-suited substrate to replenish neuronal Krebs cycle intermediates.

Lymphocyte Glucose and Glutamine Metabolism as Targets of the Anti-Inflammatory and Immunomodulatory Effects of Exercise

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Frederick Wasinski

2014-01-01

Full Text Available Glucose and glutamine are important energetic and biosynthetic nutrients for T and B lymphocytes. These cells consume both nutrients at high rates in a function-dependent manner. In other words, the pathways that control lymphocyte function and survival directly control the glucose and glutamine metabolic pathways. Therefore, lymphocytes in different functional states reprogram their glucose and glutamine metabolism to balance their requirement for ATP and macromolecule production. The tight association between metabolism and function in these cells was suggested to introduce the possibility of several pathologies resulting from the inability of lymphocytes to meet their nutrient demands under a given condition. In fact, disruptions in lymphocyte metabolism and function have been observed in different inflammatory, metabolic, and autoimmune pathologies. Regular physical exercise and physical activity offer protection against several chronic pathologies, and this benefit has been associated with the anti-inflammatory and immunomodulatory effects of exercise/physical activity. Chronic exercise induces changes in lymphocyte functionality and substrate metabolism. In the present review, we discuss whether the beneficial effects of exercise on lymphocyte function in health and disease are associated with modulation of the glucose and glutamine metabolic pathways.

Glutamine-enriched enteral nutrition in very low-birth-weight infants

NARCIS (Netherlands)

van den Berg, Anemone; van Zwol, Annelies; Moll, Henriëtte A.; Fetter, Willem P. F.; van Elburg, Ruurd M.

2007-01-01

Objective: To determine the effect of glutamine-enriched enteral nutrition in very low- birth- weight infants on the incidence of allergic and infectious diseases during the first year of life. Design: Follow- up study. Setting: Tertiary care hospital. Participants: All surviving infants who

Inhibition of glutamine synthesis induces glutamate dehydrogenase-dependent ammonia fixation into alanine in co-cultures of astrocytes and neurons.

Science.gov (United States)

Dadsetan, Sherry; Bak, Lasse K; Sørensen, Michael; Keiding, Susanne; Vilstrup, Hendrik; Ott, Peter; Leke, Renata; Schousboe, Arne; Waagepetersen, Helle S

2011-09-01

It has been previously demonstrated that ammonia exposure of neurons and astrocytes in co-culture leads to net synthesis not only of glutamine but also of alanine. The latter process involves the concerted action of glutamate dehydrogenase (GDH) and alanine aminotransferase (ALAT). In the present study it was investigated if the glutamine synthetase (GS) inhibitor methionine sulfoximine (MSO) would enhance alanine synthesis by blocking the GS-dependent ammonia scavenging process. Hence, co-cultures of neurons and astrocytes were incubated for 2.5h with [U-(13)C]glucose to monitor de novo synthesis of alanine and glutamine in the absence and presence of 5.0 mM NH(4)Cl and 10 mM MSO. Ammonia exposure led to increased incorporation of label but not to a significant increase in the amount of these amino acids. However, in the presence of MSO, glutamine synthesis was blocked and synthesis of alanine increased leading to an elevated content intra- as well as extracellularly of this amino acid. Treatment with MSO led to a dramatic decrease in glutamine content and increased the intracellular contents of glutamate and aspartate. The large increase in alanine during exposure to MSO underlines the importance of the GDH and ALAT biosynthetic pathway for ammonia fixation, and it points to the use of a GS inhibitor to ameliorate the brain toxicity and edema induced by hyperammonemia, events likely related to glutamine synthesis. Copyright © 2011 Elsevier Ltd. All rights reserved.

Oral supplementations with L-glutamine or L-alanyl-L-glutamine do not change metabolic alterations induced by long-term high-fat diet in the B6.129F2/J mouse model of insulin resistance.

Science.gov (United States)

Bock, Patricia Martins; Krause, Mauricio; Schroeder, Helena Trevisan; Hahn, Gabriela Fernandes; Takahashi, Hilton Kenji; Schöler, Cinthia Maria; Nicoletti, Graziella; Neto, Luiz Domingos Zavarize; Rodrigues, Maria Inês Lavina; Bruxel, Maciel Alencar; Homem de Bittencourt, Paulo Ivo

2016-01-01

In this work, we aimed to investigate the effects of long-term supplementations with L-glutamine or L-alanyl-L-glutamine in the high-fat diet (HFD)-fed B6.129SF2/J mouse model over insulin sensitivity response and signaling, oxidative stress markers, metabolism and HSP70 expression. Mice were fed in a standard low-fat diet (STA) or a HFD for 20 weeks. In the 21th week, mice from the HFD group were allocated in five groups and supplemented for additional 8 weeks with different amino acids: HFD control group (HFD-Con), HFD + dipeptide L-alanyl-L-glutamine group (HFD-Dip), HFD + L-alanine group (HFD-Ala), HFD + L-glutamine group (HFD-Gln), or the HFD + L-alanine + L-glutamine (in their free forms) group (HFD-Ala + Gln). HFD induced higher body weight, fat pad, fasted glucose, and total cholesterol in comparison with STA group. Amino acid supplementations did not induce any modifications in these parameters. Although insulin tolerance tests indicated insulin resistance in all HFD groups, amino acid supplementations did not improve insulin sensitivity in the present model. There were also no significant differences in the immunocontents of insulin receptor, Akt, and Toll-like receptor-4. Notably, total 70 kDa heat shock protein (HSP72 + HSP73) contents in the liver was markedly increased in HFD-Con group as compared to STA group, which might suggest that insulin resistance is only in the beginning. Apparently, B6.129SF2/J mice are more resistant to the harmful effects of HFD through a mechanism that may include gut adaptation, reducing the absorption of nutrients, including amino acids, which may explain the lack of improvements in our intervention.

Oral glutamine increases circulating glucagon-like peptide 1, glucagon, and insulin concentrations in lean, obese, and type 2 diabetic subjects

DEFF Research Database (Denmark)

Greenfield, Jerry R; Farooqi, I Sadaf; Keogh, Julia M

2008-01-01

objective was to determine whether glutamine increases circulating GLP-1 and GIP concentrations in vivo and, if so, whether this is associated with an increase in plasma insulin. DESIGN: We recruited 8 healthy normal-weight volunteers (LEAN), 8 obese individuals with type 2 diabetes or impaired glucose...... plasma insulin concentrations. Glutamine stimulated glucagon secretion in all 3 study groups. CONCLUSION: Glutamine effectively increases circulating GLP-1, GIP, and insulin concentrations in vivo and may represent a novel therapeutic approach to stimulating insulin secretion in obesity and type 2......BACKGROUND: Incretin hormones, such as glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP), play an important role in meal-related insulin secretion. We previously demonstrated that glutamine is a potent stimulus of GLP-1 secretion in vitro. OBJECTIVE: Our...

Dose intercomparison for 400–500 keV electrons using FWT-60 film and glutamine (spectrophotometric readout) dosimeters

DEFF Research Database (Denmark)

Gupta, B. L.; Nilekani, S. R.; Gehringer, P.

1986-01-01

This paper describes the dose and the depth dose measurements with FWT-60 film and glutamine (Spectrophotometric readout) dosimeters for 400–500 keV electrons. The glutamine powder was spread uniformly in polyethylene bags and the powder thickness in each bag was 5 mg cm−2. Both techniques show...

Effects of Standard and/or Glutamine Dipeptide and/or Omega-3 ...

African Journals Online (AJOL)

Supplemented Parenteral Nutrition on Neutrophil Functions, Interleukin-8 Level and Length of ... Standard TPN and glutamine and lipid emulsion with omega 3 fatty acids were given to colorectal cancer patients and the effects of these to neutrophil ...

Irradiation temperature effect on glutamine (spectrophotometric readout) dosimeter

International Nuclear Information System (INIS)

Gupta, B.L.; Narayan, G.R.; Nilekani, S.R.; Bhat, R.M.

2001-01-01

For the dose estimation using glutamine dosimeter, 20 mg L-glutamine powder is dissolved in 10 ml of a solution which contains 2x10 -3 mol dm -3 ferrous ammonium sulphate and 10 -4 mol dm -3 xylenol orange in aerated aqueous 0.033 mol dm -3 sulphuric acid (FX). The plot of absorbance at 549 nm against dose is non-linear, however, the plot of 1/absorbance vs. 1/dose is linear. The slope of this linear plot changes above an absorbance of 0.3 corresponding to a dose of about 15 kGy. The response of the dosimeter is independent of irradiation temperature in the temperature range of 23-30 deg. C within the uncertainty of dose measurement. Below 23 deg. C, the absorbance decreases by 1.23% per deg. sign C decrease in temperature while between 30 and 40 deg. C, the absorbance increases by 0.75% per deg. C increase in temperature. Above 40 deg. C, the absorbance increases by 0.2% per deg. C only. The absorbance is corrected for the irradiation temperature and the dose is read from a calibration graph at 25 deg. C. Either a linear or polynomial relation can be used for the dose calculation

The Effectiveness of Combined Use of Antioxidant and Glutamine in Abdominal Sepsis

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V. V. Nazaretyan

2017-01-01

Full Text Available Aim of the study: the effectiveness of concomitant use of antioxidant therapy with antioxidant 2-ethyl-6- methyl-3-hydroxypyridine succinate (mexidol and intensive nutritional support with glutamine in patients with abdominal sepsis (AS. Materials and methods. 170 patients with abdominal sepsis (AS involved in the study were separated into two groups. Patients of group 1 (control group, n=70 received basic treatment. Patients from group 2 (n=100 were divided into 2 subgroups. Patients from the subgroup 21 (n=70, in additon to the basic treatment, received intravenously, by drop infusion, mexidol (2000 mg per day and dipeptiven (27.5 g per day, patients from subgroup 22 (n=30 additionally to that received per os glutamine. Survival analysis was carried out according to the Kaplan-Meier method with using of the Cox's F-test and Mantel-Cox test for testing of statistical hypotheses. Results. Treatment outcomes analysis showed that in the basic group 2, mortality was lower than in the control group 1. A statistically significant increase of cumulative part in the survivors was revealed using mexidol and glutamine. Conclusion. Concomitant intravenous administration of medications had positive effects on treatment outcomes. Following on from the analysis results, we may suggest that the pair mexidol + dipeptiven interrupts the cascade of development of abdominal sepsis and contributes to avoiding a critical condition during sepsis.

Evolution of the Maillard Reaction in Glutamine or Arginine-Dextrinomaltose Model Systems

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Silvia Pastoriza

2016-12-01

Full Text Available Enteral formulas are foods designed for medical uses to feed patients who are unable to eat normally. They are prepared by mixing proteins, amino acids, carbohydrates and fats and submitted to sterilization. During thermal treatment, the Maillard reaction takes place through the reaction of animo acids with reducing sugars. Thus, although glutamine and arginine are usually added to improve the nutritional value of enteral formulas, their final concentration may vary. Thus, in the present paper the early, intermediate, and advanced states of the Maillard reaction were studied in model systems by measuring loss of free amino acids through the decrease of fluorescence intensity with o-phtaldialdehyde (OPA, 5-Hydroximethylfurfural (HMF, furfural, glucosylisomaltol, fluorescence, and absorbance at 420 nm. The systems were prepared by mixing glutamine or arginine with dextrinomaltose (similar ingredients to those used in special enteral formula, and heated at 100 °C, 120 °C and 140 °C for 0 to 30 min. The recorded changes in the concentration of furanic compounds was only useful for longer heating times of high temperatures, while absorbance and fluorescence measurements were useful in all the assayed conditions. In addition, easiness and sensitivity of absorbance and fluorescence make them useful techniques that could be implemented as indicators for monitoring the manufacture of special enteral formulas. Glucosylisomaltol is a useful indicator to monitor the manufacture of glutamine-enriched enteral formulas.

Evolution of the Maillard Reaction in Glutamine or Arginine-Dextrinomaltose Model Systems.

Science.gov (United States)

Pastoriza, Silvia; Rufián-Henares, José Ángel; García-Villanova, Belén; Guerra-Hernández, Eduardo

2016-12-07

Enteral formulas are foods designed for medical uses to feed patients who are unable to eat normally. They are prepared by mixing proteins, amino acids, carbohydrates and fats and submitted to sterilization. During thermal treatment, the Maillard reaction takes place through the reaction of animo acids with reducing sugars. Thus, although glutamine and arginine are usually added to improve the nutritional value of enteral formulas, their final concentration may vary. Thus, in the present paper the early, intermediate, and advanced states of the Maillard reaction were studied in model systems by measuring loss of free amino acids through the decrease of fluorescence intensity with o -phtaldialdehyde (OPA), 5-Hydroximethylfurfural (HMF), furfural, glucosylisomaltol, fluorescence, and absorbance at 420 nm. The systems were prepared by mixing glutamine or arginine with dextrinomaltose (similar ingredients to those used in special enteral formula), and heated at 100 °C, 120 °C and 140 °C for 0 to 30 min. The recorded changes in the concentration of furanic compounds was only useful for longer heating times of high temperatures, while absorbance and fluorescence measurements were useful in all the assayed conditions. In addition, easiness and sensitivity of absorbance and fluorescence make them useful techniques that could be implemented as indicators for monitoring the manufacture of special enteral formulas. Glucosylisomaltol is a useful indicator to monitor the manufacture of glutamine-enriched enteral formulas.

15N-enrichments of ammonia and glutamine in blood after infusion of 15N-ammonia in chickens fed low or high protein diet

International Nuclear Information System (INIS)

Karasawa, Yutaka; Koh, Katsuki

1985-01-01

In this experment, the blood ammonia and glutamine amide came from infused ammonia were determined when N-15 labeled ammonium acetate was intraportally infused into the chickens fed 5 or 20 % protein diet. The data obtained indicated that the infused ammonia was taken into blood glutamine amide, and also accumulated in blood as it is, in both dietary groups. 10 to 12 months old White Leghorn male birds were used. The experimental diet was fed once a day for 5 days to the birds weighting about 1.2 kg by 35 g per kg body weight. The experimental diet was consumed within 40 min in all cases. Cardiac and portal catheterization were performed for blood collection and ammonia infusion, respectively. After finishing the infusion, blood samples were taken to analyze the ammonia and glutamine contents and their N-15 enrichment. Statistical difference was not observed in the appearance of N-15 in ammonia and glutamine amide between two dietary groups. The N-15 enrichment in blood ammonia and the amide of plasma glutamine, and the calculated exogenous nitrogen in the ammonia and glutamine amide tended to be more in the 5 % protein diet group than the other. (Kako, I.)

Digestion of a single meal affects gene expression of ion and ammonia transporters and glutamine synthetase activity in the gastrointestinal tract of freshwater rainbow trout.

Science.gov (United States)

Bucking, Carol; Wood, Chris M

2012-04-01

Experiments on freshwater rainbow trout, Oncorhynchus mykiss, demonstrated how digestion affected the transcriptional expression of gastrointestinal transporters following a single satiating meal (~3% body mass ration) after a 1-week fast. Quantitative real-time polymerase chain reaction was employed to measure the relative mRNA expression of three previously cloned and sequenced transporters [H(+)-K(+)-ATPase (HKA), Na(+)/HCO(3)(-) cotransporter (NBC), and the Rhesus glycoprotein (Rhbg1; an ammonia transporter)] over a 24-h time course following feeding. Plasma total ammonia increased about threefold from pre-feeding levels to 288 μmol l(-1), whereas total ammonia levels in chyme supernatant reached a sixfold higher value (1.8 mmol l(-1)) than plasma levels. Feeding did not appear to have a statistically significant effect on the relative mRNA expression of the gastric HKA or Rhbg1. However, the relative mRNA expression of gastric NBC was increased 24 h following the ingestion of a meal. Along the intestinal tract, feeding increased the relative mRNA expression of Rhbg1, but had no effect on the expression of NBC. Expression of the gastric HKA was undetectable in the intestinal tract of freshwater rainbow trout. Digestion increased the activity of glutamine synthetase in the posterior intestine at 12 and 24 h following feeding. This study is among the first to show that there are digestion-associated changes in gene expression and enzyme activity in the gastrointestinal tract of teleost fish illustrating the dynamic plasticity of this organ. These post-prandial changes occur over the relative short-term duration of digesting a single meal.

Interactions of glutamine dipeptides with sodium dodecyl sulfate in aqueous solution measured by volume, conductivity, and fluorescence spectra

Energy Technology Data Exchange (ETDEWEB)

Yan Zhenning, E-mail: yanzzn@zzu.edu.cn [Department of Chemistry, Zhengzhou University, Zhengzhou, Henan 450001 (China); Sun Ximeng; Li Weiwei; Li Yu [Department of Chemistry, Zhengzhou University, Zhengzhou, Henan 450001 (China); Wang Jianji [Department of Chemistry, Henan Normal University, Xinxiang, Henan 453007 (China)

2011-10-15

Highlights: > Ion-ion and ion-polar group interactions are dominant interactions. > The SDS addition and temperature increase cause a dehydration effect on dipeptides. > The addition of dipeptide in water decreases the c{sub cmc} of SDS. > Enthalpy-entropy compensation takes place during micellization. > Micelle aggregation number was decreased by addition of glutamine dipeptides. - Abstract: Densities, conductivities, and fluorescence spectra of {l_brace}sodium dodecyl sulfate (SDS) + glutamine dipeptide + water{r_brace} mixtures were measured as a function of temperature. The density data have been utilized to calculate apparent molar volumes, standard partial molar volumes (V{sub 2,{phi}}{sup o}), standard partial molar volumes of transfer from water to aqueous SDS solutions ({Delta}{sub t}V{sup o}), the hydration number, partial molar expansibility (E{sub {phi}}{sup o}), and Hepler's constant of glutamine dipeptides. The critical micellar concentration (c{sub cmc}) and the degree of counterion dissociation of SDS micelles obtained from electrical conductivity data have been estimated at various concentrations of glutamine dipeptide. Thermodynamic parameters of micellization of SDS in aqueous dipeptide solutions have been determined from c{sub cmc} values and an enthalpy-entropy compensation effect was observed for the ternary systems. The pyrene fluorescence spectra were used to study the change of micropolarity produced by the interaction of SDS with glutamine dipeptide, and the aggregation behavior of SDS. The results have been interpreted in terms of solute-solvent interactions and structural changes in the mixed solutions.

Selective 15N labeling and direct observation by NMR of the active-site glutamine of Fe-containing superoxide dismutase

International Nuclear Information System (INIS)

Vance, Carrie K.; Kang, Young M.; Miller, Anne-Frances

1997-01-01

The glutamine in position 69 is one of only three conserved active-site amino acid differences between Fe- and Mn-containing superoxide dismutases (SODs). We have refined the conditions for extremely selective labeling of the side chains of glutamine with 15N, and thus obtained dramatically simplified spectra, despite the large size of Fe-SOD. The improved resolution afforded by such highly specific labeling permits the use of direct 15N detection to observe and assign Gln 69, even though its distance to the paramagnetic Fe2+ is only 5A. Selective glutamine side-chain labeling is inexpensive and has general utility for large (and paramagnet-containing) proteins

Effects of Dietary Glutamine Supplementation on the Body Composition and Protein Status of Early-Weaned Mice Inoculated with Mycobacterium bovis Bacillus Calmette-Guerin

Science.gov (United States)

Rogero, Marcelo Macedo; Borges, Maria Carolina; de Castro, Inar Alves; Pires, Ivanir S. O.; Borelli, Primavera; Tirapegui, Julio

2011-01-01

Glutamine, one of the most abundant amino acids found in maternal milk, favors protein anabolism. Early-weaned babies are deprived of this source of glutamine, in a period during which endogenous biosynthesis may be insufficient for tissue needs in states of metabolic stress, mainly during infections. The objective of this study was to verify the effects of dietary glutamine supplementation on the body composition and visceral protein status of early-weaned mice inoculated with Mycobacterium bovis Bacillus Calmette-Guérin (BCG). Mice were weaned early on their 14th day of life and seperated into two groups, one of which was fed a glutamine-free diet (n = 16) and the other a glutamine-supplemented diet (40 g/kg diet) (n = 16). At 21 days of age, some mice were intraperitoneally injected with BCG. Euthanasia was performed at the 28th day of age. BCG inoculation significantly reduced body weight (P < 0.001), lean mass (P = 0.002), water (P = 0.006), protein (P = 0.007) and lipid content (P = 0.001) in the carcass. Dietary glutamine supplementation resulted in a significant increase in serum IGF-1 (P = 0.019) and albumin (P = 0.025) concentration, muscle protein concentration (P = 0.035) and lipid content (P = 0.002) in the carcass. In conclusion, dietary glutamine supplementation had a positive influence on visceral protein status but did not affect body composition in early-weaned mice inoculated with BCG. PMID:22254124

Effects of Dietary Glutamine Supplementation on the Body Composition and Protein Status of Early-Weaned Mice Inoculated with Mycobacterium bovis Bacillus Calmette-Guerin

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Ivanir S. O. Pires

2011-08-01

Full Text Available Glutamine, one of the most abundant amino acids found in maternal milk, favors protein anabolism. Early-weaned babies are deprived of this source of glutamine, in a period during which endogenous biosynthesis may be insufficient for tissue needs in states of metabolic stress, mainly during infections. The objective of this study was to verify the effects of dietary glutamine supplementation on the body composition and visceral protein status of early-weaned mice inoculated with Mycobacterium bovis Bacillus Calmette-Guérin (BCG. Mice were weaned early on their 14th day of life and seperated into two groups, one of which was fed a glutamine-free diet (n = 16 and the other a glutamine-supplemented diet (40 g/kg diet (n = 16. At 21 days of age, some mice were intraperitoneally injected with BCG. Euthanasia was performed at the 28th day of age. BCG inoculation significantly reduced body weight (P < 0.001, lean mass (P = 0.002, water (P = 0.006, protein (P = 0.007 and lipid content (P = 0.001 in the carcass. Dietary glutamine supplementation resulted in a significant increase in serum IGF-1 (P = 0.019 and albumin (P = 0.025 concentration, muscle protein concentration (P = 0.035 and lipid content (P = 0.002 in the carcass. In conclusion, dietary glutamine supplementation had a positive influence on visceral protein status but did not affect body composition in early-weaned mice inoculated with BCG.

Evidence for Tautomerisation of Glutamine in BLUF Blue Light Receptors by Vibrational Spectroscopy and Computational Chemistry

Science.gov (United States)

Domratcheva, Tatiana; Hartmann, Elisabeth; Schlichting, Ilme; Kottke, Tilman

2016-01-01

BLUF (blue light sensor using flavin) domains regulate the activity of various enzymatic effector domains in bacteria and euglenids. BLUF features a unique photoactivation through restructuring of the hydrogen-bonding network as opposed to a redox reaction or an isomerization of the chromophore. A conserved glutamine residue close to the flavin chromophore plays a central role in the light response, but the underlying modification is still unclear. We labelled this glutamine with 15N in two representative BLUF domains and performed time-resolved infrared double difference spectroscopy. The assignment of the signals was conducted by extensive quantum chemical calculations on large models with 187 atoms reproducing the UV-vis and infrared signatures of BLUF photoactivation. In the dark state, the comparatively low frequency of 1,667 cm−1 is assigned to the glutamine C=O accepting a hydrogen bond from tyrosine. In the light state, the signature of a tautomerised glutamine was extracted with the C=N stretch at ~1,691 cm−1 exhibiting the characteristic strong downshift by 15N labelling. Moreover, an indirect isotope effect on the flavin C4=O stretch was found. We conclude that photoactivation of the BLUF receptor does not only involve a rearrangement of hydrogen bonds but includes a change in covalent bonds of the protein. PMID:26947391

Glutamine and alanine-induced differential expression of intracellular IL-6, IL-8, and TNF-α in LPS-stimulated monocytes in human whole-blood.

Science.gov (United States)

Raspé, C; Czeslick, E; Weimann, A; Schinke, C; Leimert, A; Kellner, P; Simm, A; Bucher, M; Sablotzki, A

2013-04-01

To investigate the effects of the commonly-used immunomodulators l-glutamine, l-alanine, and the combination of both l-alanyl-l-glutamine (Dipeptamin(®)) on intracellular expression of IL-6, IL-8, and TNF-α during endotoxemia, lipopolysaccharide (LPS)-stimulated human monocytes in a whole blood system were investigated by flow cytometry. Whole blood of twenty-seven healthy volunteers was stimulated with LPS and incubated with three different amino acid solutions (1. l-glutamine, 2. l-alanine, 3. l-alanyl-l-glutamine, each concentration 2 mM, 5 mM, incubation time 3 h). CD14(+) monocytes were phenotyped in whole-blood and intracellular expression of cytokines was assessed by flow cytometry. Our investigations showed for the first time in whole blood probes, imitating best physiologically present cellular interactions, that l-glutamine caused a dose-independent inhibitory effect on IL-6 and TNF-α production in human monocytes stimulated with LPS. However, l-alanine had contrary effects on IL-6 expression, significantly upregulating expression of IL-6 in LPS-treated monocytes. The impact of l-alanine on the expression of TNF-α was comparable with glutamine. Neither amino acid was able to affect IL-8 production in LPS-stimulated monocytes. The combination of both did not influence significantly IL-6 and IL-8 expression in monocytes during endotoxemia, however strongly reduced TNF-α production. For the regulation of TNF-α, l-glutamine, l-alanine and the combination of both show a congruent and exponentiated downregulating effect during endotoxemia, for the modulation of IL-6, l-glutamine and l-alanine featured opposite regulation leading to a canceling impact of each other when recombining both amino acids. Copyright © 2013 Elsevier Ltd. All rights reserved.

A randomised trial of enteral glutamine supplementation for very preterm children showed no beneficial or adverse long-term neurodevelopmental outcomes

NARCIS (Netherlands)

Twilhaar, E. Sabrina; de Kieviet, Jorrit F.; Oosterlaan, Jaap; van Elburg, Ruurd M.

2017-01-01

This study evaluated the long-term effects of enteral glutamine supplementation on neurodevelopmental outcomes of a Dutch cohort of very preterm children at 13 years of age. The cohort was enrolled in a randomised placebo-controlled trial between 2001-2003 in which infants received glutamine- or

Impact of dietary glutamine on amino acid digestibility values and ...

African Journals Online (AJOL)

Nebonid F. Namroud

2017-05-22

May 22, 2017 ... optimum growth during and after the critical period of birds' life. However ... For the first 18 days of incubation, the temperature was set at. 37.8 ºC ... Segments were cut longitudinally and flushed with cold phosphate-buffered saline (PBS). For ...... Muscle glutamine depletion in the intensive care unit. Int. J.

Is long term creatine and glutamine supplementation effective in enhancing physical performance of military police officers?

Science.gov (United States)

da Silveira, Celismar Lázaro; de Souza, Thiago Siqueira Paiva; Batista, Gilmário Ricarte; de Araújo, Adenilson Targino; da Silva, Júlio César Gomes; de Sousa, Maria do Socorro Cirilo; Marta, Carlos; Garrido, Nuno Domingo

2014-09-29

The objective of this study was to analyze the effect of supplementation with creatine and glutamine on physical fitness of military police officers. Therefore, an experimental double blind study was developed, with the final sample composed by 32 men randomly distributed into three groups: a group supplemented with creatine (n=10), glutamine (n=10) and a placebo group (n=12) and evaluated in three distinct moments, in an interval of three months (T1, T2 and T3). The physical training had a weekly frequency of 5 sessions × 90 min, including strength exercises, local muscular resistance, flexibility and both aerobic and anaerobic capacity. After analyzing the effect of time, group and interaction (group × time) for measures that indicated the physical capabilities of the subjects, a significant effect of time for the entire variable was identified (p0,05). In face of the results it was concluded that supplementation with creatine and glutamine showed no ergogenic effect on physical performance in military police officers.

7T Proton Magnetic Resonance Spectroscopy of Gamma-Aminobutyric Acid, Glutamate, and Glutamine Reveals Altered Concentrations in Patients With Schizophrenia and Healthy Siblings

DEFF Research Database (Denmark)

Thakkar, Katharine N; Rösler, Lara; Wijnen, Jannie P

2017-01-01

BACKGROUND: The N-methyl-D-aspartate receptor hypofunction model of schizophrenia predicts dysfunction in both glutamatergic and gamma-aminobutyric acidergic (GABAergic) transmission. We addressed this hypothesis by measuring GABA, glutamate, glutamine, and the sum of glutamine plus glutamate...... concentrations in vivo in patients with schizophrenia using proton magnetic resonance spectroscopy at 7T, which allows separation of metabolites that would otherwise overlap at lower field strengths. In addition, we investigated whether altered levels of GABA, glutamate, glutamine, and the sum of glutamine plus...... glutamate reflect genetic vulnerability to schizophrenia by including healthy first-degree relatives. METHODS: Proton magnetic resonance spectroscopy at 7T was performed in 21 patients with chronic schizophrenia who were taking medication, 23 healthy first-degree relatives of patients with schizophrenia...

Glutamine Triggers and Potentiates Glucagon-Like Peptide-1 Secretion by Raising Cytosolic Ca2+ and cAMP

OpenAIRE

Tolhurst, Gwen; Zheng, Yue; Parker, Helen E.; Habib, Abdella M.; Reimann, Frank; Gribble, Fiona M.

2011-01-01

L-glutamine stimulates glucagon-like peptide 1 (GLP-1) secretion in human subjects and cell lines. As recent advances have enabled the study of primary GLP-1–releasing L cells, this study aimed to characterize glutamine-sensing pathways in native murine L cells. L cells were identified using transgenic mice with cell-specific expression of fluorescent markers. Cells were studied in primary colonic cultures from adult mice, or purified by flow cytometry for expression analysis. Intracellular C...

Glutamine-enriched enteral diet increases splanchnic blood flow in the rat

NARCIS (Netherlands)

Houdijk, A. P.; van Leeuwen, P. A.; Boermeester, M. A.; van Lambalgen, T.; Teerlink, T.; FLINKERBUSCH, E. L.; Sauerwein, H. P.; Wesdorp, R. I.

1994-01-01

The hemodynamic consequences of glutamine (Gln)-enriched nutrition have not been investigated. This study investigates the effects of a Gln-enriched enteral diet on organ blood flows and systemic hemodynamics. Male Fischer 344 rats (n = 24) were randomized to a group that received a 12.5% (wt/wt)

Glutamine prevents gastric oxidative stress in an animal model of portal hypertension gastropathy.

Science.gov (United States)

Marques, Camila; Mauriz, José L; Simonetto, Douglas; Marroni, Claudio A; Tuñon, María J; González-Gallego, Javier; Marrón, Norma P

2011-01-01

Portal hypertension (PHI) is a clinical syndrome characterized by increases of the blood flow and/or of the vascular resistance in the portal system. A direct consequence of PHI can appearance different lesions on the gastric mucosa and submucosa, cumulatively termed portal hypertensive gastropathy (PHG). To investigate the effects of glutamine on oxidative stress in an experimental model of PHG induced by partial portal vein ligation (PPVL). Portal pressure, transaminase and alkaline phosphatase activity were quantified. Gastric tissue damage was assessed by histological analysis. Oxidative stress was measured by quantification of cytosolic concentration of thiobarbituric acid reactive substances (TBARS), hydroperoxide-initiated chemiluminescence (QL), and nitric oxide (NO) production. Moreover, activities of the antioxidant enzymes superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT) were analyzed. Transaminase and alkaline phosphatase activities were not significantly modified by PPVL, indicating absence of liver injury. Histological analysis of gastric sections showed a lost of normal architecture, with edema and vasodilatation. TBARS, QL, and NO production were significantly increased in PPVL animals. A reduction of SOD activity was found. Glutamine administration markedly alleviated histological abnormalities and oxidative stress, normalized SOD activity, and blocked NO overproduction. Our results confirm that the use of molecules with antioxidant capacity can provide protection of the gastric tissue in portal hypertension. Glutamine treatment can be useful to reduce the oxidative damage induced by PHI on gastric tissue.

Effects of combined pulse electromagnetic field stimulation plus glutamine on the healing of colonic anastomosis in rats.

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Girgin, Sadullah; Gedik, Ercan; Ozturk, Hayrettin; Akpolat, Veysi; Akbulut, Veysi; Kale, Ebru; Buyukbayram, Huseyin; Celik, Salih

2009-04-01

An experimental study was designed to investigate the effect of combined pulse electromagnetic field (PEMF) stimulation plus glutamine administration on colonic anastomosis. Anastomosis of the left colon was performed in 28 rats, which were divided into four groups; Group 1: normal resection anastomosis plus oral 50 mg/kg/day glutamine; Group 2: normal resection anastomosis plus PEMF stimulation plus oral 50 mg/kg/day glutamine; Group 3: normal resection anastomosis plus PEMF stimulation; Group 4: normal resection anastomosis. On the seventh postoperative day, the animals were killed and the bursting pressure and tissue hydroxyproline concentration of the anastomosis were analyzed and compared. The mean anastomotic bursting pressure in Group 2 was significantly higher than in Groups 1 and 4. On the other hand, the mean anastomotic bursting pressure in Group 1 was significantly higher than in Group 4. The collagen deposition and the fibroblast infiltration were significantly increased on the seventh day in Group 3 compared the other groups. On the other hand, Groups 1 and 2 had higher scores for collagen deposition and fibroblast infiltration than Group 4. In conclusion, burst pressures, hydroxyproline, and histologic features (fibroblast infiltration and collagen deposition) were improved in the PEMF group, and both PEMF and glutamine-enriched nutrition provide a significant gain in the strength of colonic anastomoses in rats.

Rapid approach for cloning bacterial single-genes directly from soils ...

African Journals Online (AJOL)

Obtaining functional genes of bacteria from environmental samples usually depends on library-based approach which is not favored as its large amount of work with small possibility of positive clones. A kind of bacterial single-gene encoding glutamine synthetase (GS) was selected as example to detect the efficiency of ...

Analysis of Peptides and Conjugates by Amino Acid Analysis

DEFF Research Database (Denmark)

Højrup, Peter

2015-01-01

Amino acid analysis is a highly accurate method for characterization of the composition of synthetic peptides. Together with mass spectrometry, it gives a reliable control of peptide quality and quantity before conjugation and immunization.Peptides are hydrolyzed, preferably in gas phase, with 6 M...... HCl at 110 °C for 20-24 h and the resulting amino acids analyzed by ion-exchange chromatography with post-column ninhydrin derivatization. Depending on the hydrolysis conditions, tryptophan is destroyed, and cysteine also, unless derivatized, and the amides, glutamine and asparagine, are deamidated...... to glutamic acid and aspartic acid, respectively. Three different ways of calculating results are suggested, and taking the above limitations into account, a quantitation better than 5 % can usually be obtained....

Glutamine methylation in histone H2A is an RNA-polymerase-I-dedicated modification

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Tessarz, Peter; Santos-Rosa, Helena; Robson, Sam C.; Sylvestersen, Kathrine B.; Nelson, Christopher J.; Nielsen, Michael L.; Kouzarides, Tony

2014-01-01

Nucleosomes are decorated with numerous post-translational modifications capable of influencing many DNA processes. Here we describe a new class of histone modification, methylation of glutamine, occurring on yeast histone H2A at position 105 (Q105) and human H2A at Q104. We identify Nop1 as the methyltransferase in yeast and demonstrate that fibrillarin is the orthologue enzyme in human cells. Glutamine methylation of H2A is restricted to the nucleolus. Global analysis in yeast, using an H2AQ105me-specific antibody, shows that this modification is exclusively enriched over the 35S ribosomal DNA transcriptional unit. We show that the Q105 residue is part of the binding site for the histone chaperone FACT (facilitator of chromatin transcription) complex. Methylation of Q105 or its substitution to alanine disrupts binding to FACT in vitro. A yeast strain mutated at Q105 shows reduced histone incorporation and increased transcription at the ribosomal DNA locus. These features are phenocopied by mutations in FACT complex components. Together these data identify glutamine methylation of H2A as the first histone epigenetic mark dedicated to a specific RNA polymerase and define its function as a regulator of FACT interaction with nucleosomes.

effects of standard and/or glutamine dipeptide and/or omega-3 fatty

African Journals Online (AJOL)

2013-02-01

Feb 1, 2013 ... effects of these to neutrophil functions and IL-8 levels are compared. Methods: ... acid solution to S-O group and TPN with omega 3 fatty acids solution and glutamine to S-D-O group ..... exudation involving multiple cell types.

Simultaneous infusion of glutamine and branched-chain amino acids (BCAA) to septic rats does not have more favorable effect on protein synthesis in muscle, liver, and small intestine than separate infusions.

Science.gov (United States)

Holecek, Milan; Muthny, Tomas; Kovarik, Miroslav; Sispera, Ludek

2006-01-01

Glutamine and branched-chain amino acids (BCAA; valine, leucine, and isoleucine) are used as nutrition supplements in the treatment of proteocatabolic illness. We hypothesized that simultaneous administration of BCAA and glutamine affects protein metabolism more significantly than separate administration. In the present study, we evaluated their effect on protein synthesis in skeletal muscle, liver, and jejunum of septic rats. Twenty-four hours after induction of sepsis by subcutaneous injection of turpentine, the rats were infused for 6 hours with 5 mL of 1.75% glutamine, 1.75% BCAA, 1.75% glutamine+BCAA, or saline solution. The control group consisted of intact rats infused with saline. Protein synthesis was measured at the end of infusion by a "flooding method" with [3,4,5-(3)H]phenylalanine. In turpentine-treated animals, we observed a decrease in glutamine concentration in blood plasma and skeletal muscle, a decrease in BCAA concentration in liver and jejunum, and a decrease in protein synthesis in all tissues. Glutamine or glutamine+BCAA infusion increased glutamine concentration in plasma and muscle and stimulated protein synthesis in the liver. The BCAA infusion enhanced concentrations of BCAA in plasma and tissues, but the effect of BCAA on protein synthesis was insignificant. Synergistic effect of simultaneous infusion of glutamine and BCAA on protein synthesis was not observed. We conclude that glutamine infusion to rats with septic injury may significantly improve impaired protein synthesis in the liver and that there is no synergistic effect of glutamine and BCAA infusion on protein synthesis in skeletal muscle, liver, and jejunum.

Is Long Term Creatine and Glutamine Supplementation Effective in Enhancing Physical Performance of Military Police Officers?

Directory of Open Access Journals (Sweden)

Lázaro da Silveira Celismar

2014-12-01

Full Text Available The objective of this study was to analyze the effect of supplementation with creatine and glutamine on physical fitness of military police officers. Therefore, an experimental double blind study was developed, with the final sample composed by 32 men randomly distributed into three groups: a group supplemented with creatine (n=10, glutamine (n=10 and a placebo group (n=12 and evaluated in three distinct moments, in an interval of three months (T1, T2 and T3. The physical training had a weekly frequency of 5 sessions x 90 min, including strength exercises, local muscular resistance, flexibility and both aerobic and anaerobic capacity. After analyzing the effect of time, group and interaction (group x time for measures that indicated the physical capabilities of the subjects, a significant effect of time for the entire variable was identified (p0,05. In face of the results it was concluded that supplementation with creatine and glutamine showed no ergogenic effect on physical performance in military police officers.

A meta-analysis of trials using the intention to treat principle for glutamine supplementation in critically ill patients with burn.

Science.gov (United States)

Lin, Jiun-Jie; Chung, Xiu-Juan; Yang, Chung-Yih; Lau, Hui-Ling

2013-06-01

During critical illness, the demand for glutamine may exceed that which can be mobilized from muscle stores. Infections increase mortality, morbidity, length-of-stay, antibiotic usage and the cost of care. This is a major health care issue. RCTs were identified from the electronic databases: the Cochrane Library, MEDLINE, PubMed web of knowledge and hand searching journals. The trials compared the supplementation with glutamine and non-supplementation in burn. Statistical analysis was performed using RevMan5.1 software, from Cochrane Collaboration. 216 papers showed a match, in the keyword search. Upon screening the title, reading the abstract and the entire article, only four RCTs, involving 155 patients, were included. For both the glutamine group and control group, total burn surface area (TBSA) (MD=2.02, 95% CI -2.17, 6.21, p=0.34) was similar. Glutamine supplementation was associated with a statistically significant decrease in the number of patients with gram-negative bacteremia (OR 0.27, 95% CI 0.08-0.92, p=0.04) and hospital mortality (OR=0.13, 95% CI 0.03, 0.51, p=0.004), however, no statistical difference was noted between groups, for the other results. Glutamine supplemented nutrition can be associated with a reduction in mortality in hospital, complications due to gram-negative bacteremia in burn patients. Further larger and better quality trials are required, in order to determine whether any differences are statistically and clinically important. Copyright © 2012 Elsevier Ltd and ISBI. All rights reserved.

Zinc, vitamin A, and glutamine supplementation in Brazilian shantytown children at risk for diarrhea results in sex-specific improvements in verbal learning

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Aldo A. M. Lima

2013-01-01

Full Text Available OBJECTIVE: To identify the impact of supplemental zinc, vitamin A, and glutamine, alone or in combination, on long-term cognitive outcomes among Brazilian shantytown children with low median height-for-age z-scores. METHODS: A randomized, double-blind, placebo-controlled trial was conducted in children aged three months to nine years old from the urban shanty compound community of Fortaleza, Brazil. Demographic and anthropometric information was assessed. The random treatment groups available for cognitive testing (total of 167 children were: (1 placebo, n = 25; (2 glutamine, n = 23; (3 zinc, n = 18; (4 vitamin A, n = 19; (5 glutamine+zinc, n = 20; (6 glutamine+vitamin A, n = 21; (7 zinc+vitamin A, n = 23; and (8 glutamine+zinc+vitamin A, n = 18. Neuropsychological tests were administered for the cognitive domains of non-verbal intelligence and abstraction, psychomotor speed, verbal memory and recall ability, and semantic and phonetic verbal fluency. Statistical analyses were performed using SPSS, version 16.0. ClinicalTrials.gov: NCT00133406. RESULTS: Girls receiving a combination of glutamine, zinc, and vitamin A had higher mean age-adjusted verbal learning scores than girls receiving only placebo (9.5 versus 6.4, p = 0.007 and girls receiving zinc+vitamin A (9.5 versus 6.5, p = 0.006. Similar group differences were not found between male study children. CONCLUSIONS: The findings suggest that combination therapy offers a sex-specific advantage on tests of verbal learning, similar to that seen among female patients following traumatic brain injury.

Disruption of the Glutamate–Glutamine Cycle Involving Astrocytes in an Animal Model of Depression for Males and Females

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Rappeneau, Virginie; Blaker, Amanda; Petro, Jeff R.; Yamamoto, Bryan K.; Shimamoto, Akiko

2016-01-01

Background: Women are twice as likely as men to develop major depression. The brain mechanisms underlying this sex disparity are not clear. Disruption of the glutamate–glutamine cycle has been implicated in psychiatric disturbances. This study identifies sex-based impairments in the glutamate–glutamine cycle involving astrocytes using an animal model of depression. Methods: Male and female adult Long-Evans rats were exposed to chronic social defeat stress (CSDS) for 21 days, using a modified resident-intruder paradigm. Territorial aggression was used for males and maternal aggression was used for females to induce depressive-like deficits for intruders. The depressive-like phenotype was assessed with intake for saccharin solution, weight gain, estrous cycle, and corticosterone (CORT). Behaviors displayed by the intruders during daily encounters with residents were characterized. Rats with daily handling were used as controls for each sex. Ten days after the last encounter, both the intruders and controls were subjected to a no-net-flux in vivo microdialysis to assess glutamate accumulation and extracellular glutamine in the nucleus accumbens (NAc). The contralateral hemispheres were used for determining changes in astrocytic markers, including glial fibrillary acidic protein (GFAP) and glutamate transporter-1 (GLT-1). Results: Both male and female intruders reduced saccharin intake over the course of CSDS, compared to their pre-stress period and to their respective controls. Male intruders exhibited submissive/defensive behaviors to territorial aggression by receiving sideways threats and bites. These males showed reductions in striatal GLT-1 and spontaneous glutamine in the NAc, compared to controls. Female intruders exhibited isolated behaviors to maternal aggression, including immobility, rearing, and selfgrooming. Their non-reproductive days were extended. Also, they showed reductions in prefrontal and accumbal GFAP+ cells and prefrontal GLT-1, compared to

Conformation-Specific IR and UV Spectroscopy of the Amino Acid Glutamine: Amide-Stacking and Hydrogen Bonding in AN Important Residue in Neurodegenerative Diseases

Science.gov (United States)

Walsh, Patrick S.; Dean, Jacob C.; Zwier, Timothy S.

2014-06-01

Glutamine plays an important role in several neurodegenerative diseases including Huntington's disease (HD) and Alzheimer's disease (AD). An intriguing aspect of the structure of glutamine is its incorporation of an amide group in its side chain, thereby opening up the possibility of forming amide-amide H-bonds between the peptide backbone and side chain. In this study the conformational preferences of two capped gluatamines Z(carboxybenzyl)-Glutamine-X (X=OH, NHMe) are studied under jet-cooled conditions in the gas phase in order to unlock the intrinsic structural motifs that are favored by this flexible sidechain. Conformational assignments are made by comparing the hydride stretch ( 3100-3700 cm-1) and amide I and II ( 1400-1800 cm-1) resonant ion-dip infrared spectra with predictions from harmonic frequency calculations. Assigned structures will be compared to previously published results on both natural and unnatural residues. Particular emphasis will be placed on the comparison between glutamine and unconstrained γ-peptides due to the similar three-carbon spacing between backbone and side chain in glutamine to the backbone spacing in γ-peptides. The ability of the glutamine side-chain to form amide stacked conformations will be a main focus, along with the prevalence of extended backbone type structures. W. H. James, III, C W. Müller, E. G. Buchanan, M. G. D. Nix, L. Guo, L. Roskop, M. S. Gordon, L. V. Slipchenko, S. H. Gellman, and T. S. Zwier, J. Am. Chem. Soc., 2009, 131(40), 14243-14245.

7T Proton Magnetic Resonance Spectroscopy of Gamma-Aminobutyric Acid, Glutamate, and Glutamine Reveals Altered Concentrations in Patients With Schizophrenia and Healthy Siblings

NARCIS (Netherlands)

Thakkar, Katharine N; Rösler, Lara; Wijnen, Jannie P; Boer, Vincent O.; Klomp, Dennis W J; Cahn, Wiepke; Kahn, René S; Neggers, Sebastiaan F W

BACKGROUND: The N-methyl-D-aspartate receptor hypofunction model of schizophrenia predicts dysfunction in both glutamatergic and gamma-aminobutyric acidergic (GABAergic) transmission. We addressed this hypothesis by measuring GABA, glutamate, glutamine, and the sum of glutamine plus glutamate

Effect of glutamine synthetase inhibition on brain and interorgan ammonia metabolism in bile duct ligated rats

DEFF Research Database (Denmark)

Fries, Andreas W; Dadsetan, Sherry; Keiding, Susanne

2014-01-01

, and aspartate and incorporation of (15)NH4(+) into these amino acids in brain, liver, muscle, kidney, and plasma were similar in sham and BDL rats treated with saline. Methionine sulfoximine reduced glutamine concentrations in liver, kidney, and plasma but not in brain and muscle; MSO reduced incorporation...... of (15)NH4(+) into glutamine in all tissues. It did not affect alanine concentrations in any of the tissues but plasma alanine concentration increased; incorporation of (15)NH4(+) into alanine was increased in brain in sham and BDL rats and in kidney in sham rats. It inhibited GS in all tissues examined...

Time dependent effects of haloperidol on glutamine and GABA homeostasis and astrocyte activity in the rat brain

Science.gov (United States)

Konopaske, Glenn T.; Bolo, Nicolas R.; Basu, Alo C.; Renshaw, Perry F.; Coyle, Joseph T.

2013-01-01

Rationale Schizophrenia is a severe, persistent, and fairly common mental illness. Haloperidol is widely used and is effective against the symptoms of psychosis seen in schizophrenia. Chronic oral haloperidol administration decreased the number of astrocytes in the parietal cortex of macaque monkeys (Konopaske et al. Biol Psych, 2008). Since astrocytes play a key role in glutamate metabolism, chronic haloperidol administration was hypothesized to modulate astrocyte metabolic function and glutamate homeostasis. Objectives This study investigated the effects of chronic haloperidol administration on astrocyte metabolic activity and glutamate, glutamine, and GABA homeostasis. Methods We used ex vivo 13C magnetic resonance spectroscopy along with high performance liquid chromatography after [1-13C]glucose and [1,2-13C]acetate administration to analyze forebrain tissue from rats administered oral haloperidol for 1 or 6 months. Results Administration of haloperidol for 1 month produced no changes in 13C labeling of glutamate, glutamine, or GABA, or in their total levels. However, a 6 month haloperidol administration increased 13C labeling of glutamine by [1,2-13C]acetate. Moreover, total GABA levels were also increased. Haloperidol administration also increased the acetate/glucose utilization ratio for glutamine in the 6 month cohort. Conclusions Chronic haloperidol administration in rats appears to increase forebrain GABA production along with astrocyte metabolic activity. Studies exploring these processes in subjects with schizophrenia should take into account the potential confounding effects of antipsychotic medication treatment. PMID:23660600

Systematic replacement of lysine with glutamine and alanine in Escherichia coli malate synthase G: effect on crystallization

International Nuclear Information System (INIS)

Anstrom, David M.; Colip, Leslie; Moshofsky, Brian; Hatcher, Eric; Remington, S. James

2005-01-01

Alanine and glutamine mutations were made to the same 15 lysine positions on the surface of E. coli malate synthase G and the impact on crystallization observed. The results support lysine replacement for improvement of crystallization and provide insight into site selection and type of amino-acid replacement. Two proposals recommend substitution of surface lysine residues as a means to improve the quality of protein crystals. In proposal I, substitution of lysine by alanine has been suggested to improve crystallization by reducing the entropic cost of ordering flexible side chains at crystal contacts. In proposal II, substitution of lysine by residues more commonly found in crystal contacts, such as glutamine, has been proposed to improve crystallization. 15 lysine residues on the surface of Escherichia coli malate synthase G, distributed over a variety of secondary structures, were individually mutated to both alanine and glutamine. For 28 variants, detailed studies of the effect on enzymatic activity and crystallization were conducted. This has permitted direct comparison of the relative effects of the two types of mutations. While none of the variants produced crystals suitable for X-ray structural determination, small crystals were obtained in a wide variety of conditions, in support of the general approach. Glutamine substitutions were found to be more effective than alanine in producing crystals, in support of proposal II. Secondary structure at the site of mutation does not appear to play a major role in determining the rate of success

Modulation of the nuclear factor-kappa B (NF-κB) signalling pathway by glutamine in peritoneal macrophages of a murine model of protein malnutrition.

Science.gov (United States)

da Silva Lima, Fabiana; Rogero, Marcelo Macedo; Ramos, Mayara Caldas; Borelli, Primavera; Fock, Ricardo Ambrósio

2013-06-01

Protein malnutrition affects resistance to infection by impairing the inflammatory response, modifying the function of effector cells, such as macrophages. Recent studies have revealed that glutamine-a non-essential amino acid, which could become conditionally essential in some situations like trauma, infection, post-surgery and sepsis-is able to modulate the synthesis of cytokines. The aim of this study was to evaluate the effect of glutamine on the expression of proteins involved in the nuclear factor-kappa B (NF-κB) signalling pathway of peritoneal macrophages from malnourished mice. Two-month-old male Balb/c mice were submitted to protein-energy malnutrition (n = 10) with a low-protein diet containing 2 % protein, whereas control mice (n = 10) were fed a 12 % protein-containing diet. The haemogram and analysis of plasma glutamine and corticosterone were evaluated. Peritoneal macrophages were pre-treated in vitro with glutamine (0, 0.6, 2 and 10 mmol/L) for 24 h and then stimulated with 1.25 μg LPS for 30 min, and the synthesis of TNF-α and IL-1α and the expression of proteins related to the NF-κB pathway were evaluated. Malnourished animals had anaemia, leucopoenia, lower plasma glutamine and increased corticosterone levels. TNF-α production of macrophages stimulated with LPS was significantly lower in cells from malnourished animals when cultivated in supraphysiological (2 and 10 mmol/L) concentrations of glutamine. Further, glutamine has a dose-dependent effect on the activation of macrophages, in both groups, when stimulated with LPS, inducing a decrease in TNF-α and IL-1α production and negatively modulating the NF-κB signalling pathway. These data lead us to infer that the protein malnutrition state interferes with the activation of macrophages and that higher glutamine concentrations, in vitro, have the capacity to act negatively in the NF-κB signalling pathway.

N-acetylcysteine prevents HIV gp 120-related damage of human cultured astrocytes: correlation with glutamine synthase dysfunction

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Costa Nicola

2007-12-01

Full Text Available Abstract Background HIV envelope gp 120 glycoprotein is released during active HIV infection of brain macrophages thereby generating inflammation and oxidative stress which contribute to the development of the AIDS-Dementia Complex (ADC. Gp120 has also been found capable to generate excitotoxic effect on brain tissue via enhancement of glutamatergic neurotransmission, leading to neuronal and astroglial damage, though the mechanism is still to be better understood. Here we investigated on the effect of N-acetylcysteine (NAC, on gp120-induced damage in human cultured astroglial cells and the possible contribution of gp120-related reacting oxygen species (ROS in the imbalanced activity of glutamine synthase (GS, the enzyme that metabolizes glutamate into glutamine within astroglial cells playing a neuroprotective role in brain disorders. Results Incubation of Lipari human cultured astroglial cells with gp 120 (0.1–10 nM produced a significant reduction of astroglial cell viability and apoptosis as evaluated by TUNEL reaction and flow cytometric analysis (FACS. This effect was accompanied by lipid peroxidation as detected by means of malondialdehyde assay (MDA. In addition, gp 120 reduced both glutamine concentration in astroglial cell supernatants and GS expression as detected by immunocytochemistry and western blotting analysis. Pre-treatment of cells with NAC (0.5–5 mM, dose-dependently antagonised astroglial apoptotic cell death induced by gp 120, an effect accompanied by significant attenuation of MDA accumulation. Furthermore, both effects were closely associated with a significant recovery of glutamine levels in cell supernatants and by GS expression, thus suggesting that overproduction of free radicals might contribute in gp 120-related dysfunction of GS in astroglial cells. Conclusion In conclusion, the present experiments demonstrate that gp 120 is toxic to astroglial cells, an effect accompanied by lipid peroxidation and by altered

PDHA1 gene knockout in prostate cancer cells results in metabolic reprogramming towards greater glutamine dependence

Science.gov (United States)

Li, Yaqing; Li, Xiaoran; Li, Xiaoli; Zhong, Yali; Ji, Yasai; Yu, Dandan; Zhang, Mingzhi; Wen, Jian-Guo; Zhang, Hongquan; Goscinski, Mariusz Adam; Nesland, Jahn M.; Suo, Zhenhe

2016-01-01

Alternative pathways of metabolism endowed cancer cells with metabolic stress. Inhibiting the related compensatory pathways might achieve synergistic anticancer results. This study demonstrated that pyruvate dehydrogenase E1α gene knockout (PDHA1 KO) resulted in alterations in tumor cell metabolism by rendering the cells with increased expression of glutaminase1 (GLS1) and glutamate dehydrogenase1 (GLUD1), leading to an increase in glutamine-dependent cell survival. Deprivation of glutamine induced cell growth inhibition, increased reactive oxygen species and decreased ATP production. Pharmacological blockade of the glutaminolysis pathway resulted in massive tumor cells apoptosis and dysfunction of ROS scavenge in the LNCaP PDHA1 KO cells. Further examination of the key glutaminolysis enzymes in human prostate cancer samples also revealed that higher levels of GLS1 and GLUD1 expression were significantly associated with aggressive clinicopathological features and poor clinical outcome. These insights supply evidence that glutaminolysis plays a compensatory role for cell survival upon alternative energy metabolism and targeting the glutamine anaplerosis of energy metabolism via GLS1 and GLUD1 in cancer cells may offer a potential novel therapeutic strategy. PMID:27462778

Deamidated gliadin peptide antibodies as a routine test for celiac disease: a prospective analysis.

Science.gov (United States)

Volta, Umberto; Granito, Alessandro; Parisi, Claudia; Fabbri, Angela; Fiorini, Erica; Piscaglia, Maria; Tovoli, Francesco; Grasso, Valentina; Muratori, Paolo; Pappas, Georgios; De Giorgio, Roberto

2010-03-01

This study was designed to establish whether deamidated gliadin peptide antibodies (DGP-AGA) could improve the serologic workup for celiac disease (CD). The best serologic approach for CD screening is currently based on the combined detection of tissue transglutaminase (tTGA), endomysial (EmA), and gliadin antibodies (AGA). One hundred forty-four consecutive patients with gastrointestinal and extraintestinal signs suggestive for CD were investigated using serologic tests, that is, IgG and IgA DGP-AGA, IgA tTGA, IgA EmA, and duodenal biopsy. Forty-eight out of 144 patients (33%) had CD with different severity of villous atrophy. IgA tTGA showed 93.7% sensitivity compared with 91.6% for IgA EmA, 84.3% for IgA DGP-AGA, and 82.3% for IgG DGP-AGA. Of the 3 cases negative for IgA tTGA, IgA EmA, and IgA DGP-AGA, 2 had total IgA deficiency, although both were positive for IgG DGP-AGA. IgG DGP-AGA showed a very high specificity for CD (98.9%), not only superior to IgA DGP-AGA (79.8%), but also to IgA tTGA (96.6%) and very close to IgA EmA (100%). Our prospective study shows that the combined search for IgA tTGA and IgG DGP-AGA provides the best diagnostic accuracy for CD, allowing the identification of all CD cases---except one---with a very high specificity. The serologic workup for CD screening could be significantly improved by the routine introduction of IgG DGP-AGA together with IgA tTGA, thus reducing the number of tests and with an obvious advantage in terms of cost-efficacy.

Cytosolic glutamine synthetase in barley

DEFF Research Database (Denmark)

Thomsen, Hanne Cecilie

remobilisation from ageing plant parts. Thus, GS is highly involved in determining crop yield and NUE. The major objective of this PhD project was to investigate the NUE properties of transgenic barley designed to constitutively overexpress a GS1 isogene (HvGS1.1). These transgenic lines exhibited an increased...... for N demand. Of the GS isogenes, only the transcript levels of root HvGS1.1 increased when plants were transferred from high to low N. This change coincided with an increase in total GS activity. Pronounced diurnal variation was observed for root nitrate transporter genes and GS isogenes in both root...... fertilizer requirement. The enzyme glutamine synthetase (GS) has been a major topic in plant nitrogen research for decades due to its central role in plant N metabolism. The cytosolic version of this enzyme (GS1) plays an important role in relation to primary N assimilation as well as in relation to N...

Addiction to Coupling of the Warburg Effect with Glutamine Catabolism in Cancer Cells

Directory of Open Access Journals (Sweden)

Bradley Smith

2016-10-01

Full Text Available Metabolic reprogramming is critical to oncogenesis, but the emergence and function of this profound reorganization remain poorly understood. Here we find that cooperating oncogenic mutations drive large-scale metabolic reprogramming, which is both intrinsic to cancer cells and obligatory for the transition to malignancy. This involves synergistic regulation of several genes encoding metabolic enzymes, including the lactate dehydrogenases LDHA and LDHB and mitochondrial glutamic pyruvate transaminase 2 (GPT2. Notably, GPT2 engages activated glycolysis to drive the utilization of glutamine as a carbon source for TCA cycle anaplerosis in colon cancer cells. Our data indicate that the Warburg effect supports oncogenesis via GPT2-mediated coupling of pyruvate production to glutamine catabolism. Although critical to the cancer phenotype, GPT2 activity is dispensable in cells that are not fully transformed, thus pinpointing a metabolic vulnerability specifically associated with cancer cell progression to malignancy.

L-Glutamine Metabolism Is Not A Major Source Of Increased Free ...

African Journals Online (AJOL)

10 weeks (2K-1C) and 4 weeks (1K-1C) respectively after renal artery clamping, clipped rats exhibited elevated blood pressures (P<0.001), which was sustained under anaesthesia. No significant difference in plasma glutamine levels were found in hypertensive rats compared to controls (11.3±1.3 mg/l in 2K-1C vs.

Comparison of the eight weeks of supplementation Creatine and Glutamine consumption along with resistance exercise on the level of ALP in female mice

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A eskandari

2015-11-01

Full Text Available Background and purpose: in recent years, in order to improve power, speed, the increase in the volume of the musculature, preventing sports injuries and maintain the muscle performance athletes use from different resistance exercises and food supplements. In this regard, present study has been conducted with the aim of comparison the influence of an 8 week period consumption of creatine (2 gr.kg-1.day-1 in 1st week and 0.48 gr.kg-1.day-1during 2nd to 8th weeks and glutamine (1 gr.kg-1.day-1 from first to eighth weeks along with resistance exercise on level of ALP of female mice. Materials and methods: This experimental study was done on 80 Small adult female mice of Surrey species (28 ± 5 gram. The animals were randomly divided into 8 groups of: resistance exercise, resistance exercise + creatine, resistance exercise + glutamine, resistance exercise + glutamine + creatine, creatine, glutamine, creatine + glutamine and control groups (N= 10. Resistance exercise (5 days a week was including: climbing (4 sets, 5 times repetition with two minutes rest between the sets from a ladder (with the height of one meter and including 26 steps and bearing 30 percent of the weight of the Mouse body (hanging from tail in the first week and the increasing it up to 200 percent of body weight till the last week of the experiment. During 48 hours after the last practice session of resistance exercise, the blood sample was taken and the the level of ALP has been measured. Findings:The results showed that the level of ALP enzyme in creatine + glutamine + resistance exercise groug had been increased in comparison with the control group (144.3 ± 15.86 in comparison with 234.7 ± 25.69 U.L-1 P < 0.05. Conclusion: The results of this research indicate Creatine and Glutamine supplementation consumption along with resistance exercise increases in the level of ALP enzyme in the liver of mice.

Disruption of the glutamate-glutamine cycle involving astrocytes in an animal model of depression for males and females

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Virginie Rappeneau

2016-12-01

Full Text Available Background: Women are twice as likely as men to develop major depression (MD. The brain mechanisms underlying this sex disparity are not clear. Disruption of the glutamate-glutamine cycle has been implicated in psychiatric disturbances. This study identifies sex-based impairments in the glutamate-glutamine cycle involving astrocytes using an animal model of depression. Methods: Male and female adult Long-Evans rats were exposed to chronic social defeat stress (CSDS for 21 days, using a modified resident-intruder paradigm. Territorial aggression was used for males and maternal aggression was used for females to induce depressive-like deficits for intruders. The depressive-like phenotype was assessed with intake for saccharin solution, weight gain, estrous cycle, and corticosterone (CORT. Behaviors displayed by the intruders during daily encounters with residents were characterized. Rats with daily handling were used as controls for each sex. Ten days after the last encounter, both the intruders and controls were subjected to a no-net-flux in vivo microdialysis to assess glutamate accumulation and extracellular glutamine in the nucleus accumbens (NAc. The contralateral hemispheres were used for determining changes in astrocytic markers, including glial fibrillary acidic protein (GFAP and glutamate transporter-1 (GLT-1. Results: Both male and female intruders reduced saccharin intake over the course of CSDS, compared to their pre-stress period and to their respective controls. Male intruders exhibited submissive/defensive behaviors to territorial aggression by receiving sideways threats and bites. These males showed reductions in striatal GLT-1 and spontaneous glutamine in the NAc, compared to controls. Female intruders exhibited isolated behaviors to maternal aggression, including immobility, rearing, and self-grooming. Their non-reproductive days were extended. Also, they showed reductions in prefrontal and accumbal GFAP+ cells and prefrontal GLT

Aging Reduces an ERRalpha-Directed Mitochondrial Glutaminase Expression Suppressing Glutamine Anaplerosis and Osteogenic Differentiation of Mesenchymal Stem Cells.

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Huang, Tongling; Liu, Renzhong; Fu, Xuekun; Yao, Dongsheng; Yang, Meng; Liu, Qingli; Lu, William W; Wu, Chuanyue; Guan, Min

2017-02-01

Aging deteriorates osteogenic capacity of mesenchymal stem/stromal cells (MSCs), contributing to imbalanced bone remodeling and osteoporosis. Glutaminase (Gls) catabolizes glutamine into glutamate at the first step of mitochondrial glutamine (Gln)-dependent anaplerosis which is essential for MSCs upon osteogenic differentiation. Estrogen-related receptor α (ERRα) regulates genes required for mitochondrial function. Here, we found that ERRα and Gls are upregulated by osteogenic induction in human MSCs (hMSCs). In contrast, osteogenic differentiation capacity and glutamine consumption of MSCs, as well as ERRα, Gls and osteogenic marker genes are significantly reduced with age. We demonstrated that ERRα binds to response elements on Gls promoter and affects glutamine anaplerosis through transcriptional induction of Gls. Conversely, mTOR inhibitor rapamycin, ERRα inverse agonist compound 29 or Gls inhibitor BPTES leads to reduced Gln anaplerosis and deteriorated osteogenic differentiation of hMSCs. Importantly, overexpression of ERRα or Gls restored impairment by these inhibitors. Finally, we proved that compensated ERRα or Gls expression indeed potentiated Gln anaplerosis and osteogenic capability of elderly mice MSCs in vitro. Together, we establish that Gls is a novel ERRα target gene and ERRα/Gls signaling pathway plays an important role in osteogenic differentiation of MSCs, providing new sights into novel regenerative therapeutics development. Our findings suggest that restoring age-related mitochondrial Gln-dependent anaplerosis may be beneficial for degenerative bone disorders such as osteoporosis. Stem Cells 2017;35:411-424. © 2016 AlphaMed Press.

Chemical modification of L-glutamine to alpha-amino glutarimide on autoclaving facilitates Agrobacterium infection of host and non-host plants: A new use of a known compound

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Das Pralay

2011-05-01

Full Text Available Abstract Background Accidental autoclaving of L-glutamine was found to facilitate the Agrobacterium infection of a non host plant like tea in an earlier study. In the present communication, we elucidate the structural changes in L-glutamine due to autoclaving and also confirm the role of heat transformed L-glutamine in Agrobacterium mediated genetic transformation of host/non host plants. Results When autoclaved at 121°C and 15 psi for 20 or 40 min, L-glutamine was structurally modified into 5-oxo proline and 3-amino glutarimide (α-amino glutarimide, respectively. Of the two autoclaved products, only α-amino glutarimide facilitated Agrobacterium infection of a number of resistant to susceptible plants. However, the compound did not have any vir gene inducing property. Conclusions We report a one pot autoclave process for the synthesis of 5-oxo proline and α-amino glutarimide from L-glutamine. Xenobiotic detoxifying property of α-amino glutarimide is also proposed.

Effects of L-glutamine on rectal temperature and some markers of oxidative stress in Red Sokoto goats during the hot-dry season.

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Ocheja, Ohiemi Benjamin; Ayo, Joseph Olusegun; Aluwong, Tagang; Minka, Ndazo Salka

2017-08-01

The experiment investigated the ameliorative effects of L-glutamine administration on rectal temperature (RT), erythrocyte osmotic fragility (EOF), serum antioxidant enzyme activities and malondialdehyde (MDA) concentration in Red Sokoto goats during the hot-dry season. Twenty eight healthy Red Sokoto goats, comprising 14 experimental (administered 0.2 g/kg of L-glutamine dissolved in 10 mL of distilled water, once daily for 21 days) and 14 control (administered equivalent of distilled water) goats served as subjects. Rectal temperature (measured at 6:00, 13:00 and 18:00 h) and blood samples (taken at 8:00 h) were obtained from all subjects weekly, before, during and after L-glutamine administration. Data obtained were compared using one-way repeated-measures ANOVA, followed by Tukey's post-hoc test. The dry-bulb temperature, relative humidity and temperature-humidity index for the study period ranged between 24.0 and 37.5 °C, 26.0 and 84.0% and 73.0 and 86.3, respectively. L-glutamine administration decreased (P heat-stressed goats during the hot-dry season.

Growth hormone enhances fat-free mass and glutamine availability in patients with short-bowel syndrome: an ancillary double-blind, randomized crossover study.

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Seguy, David; Darmaun, Dominique; Duhamel, Alain; Thuillier, François; Cynober, Luc; Cortot, Antoine; Gottrand, Frédéric; Messing, Bernard

2014-09-01

Benefits of recombinant human growth hormone (rhGH) alone or combined with glutamine in patients with intestinal failure because of short-bowel syndrome remain controversial. We explored effects of rhGH on whole-body protein metabolism in patients with short-bowel syndrome with intestinal failure (SBS-IF) to gain insight into its mechanism of action. Eight stable hyperphagic patients with severe SBS-IF received, in a double-blind, randomized crossover study, low-dose rhGH (0.05 mg · kg⁻¹ · d⁻¹) and a placebo for two 3-wk periods. Leucine and glutamine kinetics under fasting and fed conditions, fat-free mass (FFM), and serum insulin were determined on the final day of each treatment. rhGH increased FFM and nonoxidative leucine disposal (NOLD; an index of protein synthesis) (P de novo synthesis (P de novo synthesis and intestinal absorption increase glutamine availability over the physiologic range, suggesting that beneficial effects of rhGH in hyperphagic patients might be achieved without glutamine supplementation. © 2014 American Society for Nutrition.

Knockout of GAD65 has major impact on synaptic GABA synthesized from astrocyte-derived glutamine

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Walls, Anne Byriel; Eyjolfsson, Elvar M.; Smeland, Olav B.

2011-01-01

γ-Aminobutyric acid (GABA) synthesis from glutamate is catalyzed by glutamate decarboxylase (GAD) of which two isoforms, GAD65 and GAD67, have been identified. The GAD65 has repeatedly been shown to be important during intensified synaptic activity. To specifically elucidate the significance of G...... glutamine both via direct synthesis and via a pathway involving mitochondrial metabolism. Furthermore, a severe neuronal hypometabolism, involving glycolysis and tricarboxylic acid (TCA) cycle activity, was observed in cerebral cortex of GAD65 knockout mice.......65 for maintenance of the highly compartmentalized intracellular and intercellular GABA homeostasis, GAD65 knockout and corresponding wild-type mice were injected with [1-(13)C]glucose and the astrocyte-specific substrate [1,2-(13)C]acetate. Synthesis of GABA from glutamine in the GABAergic synapses...

7T Proton Magnetic Resonance Spectroscopy of Gamma-Aminobutyric Acid, Glutamate, and Glutamine Reveals Altered Concentrations in Patients With Schizophrenia and Healthy Siblings.

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Thakkar, Katharine N; Rösler, Lara; Wijnen, Jannie P; Boer, Vincent O; Klomp, Dennis W J; Cahn, Wiepke; Kahn, René S; Neggers, Sebastiaan F W

2017-03-15

The N-methyl-D-aspartate receptor hypofunction model of schizophrenia predicts dysfunction in both glutamatergic and gamma-aminobutyric acidergic (GABAergic) transmission. We addressed this hypothesis by measuring GABA, glutamate, glutamine, and the sum of glutamine plus glutamate concentrations in vivo in patients with schizophrenia using proton magnetic resonance spectroscopy at 7T, which allows separation of metabolites that would otherwise overlap at lower field strengths. In addition, we investigated whether altered levels of GABA, glutamate, glutamine, and the sum of glutamine plus glutamate reflect genetic vulnerability to schizophrenia by including healthy first-degree relatives. Proton magnetic resonance spectroscopy at 7T was performed in 21 patients with chronic schizophrenia who were taking medication, 23 healthy first-degree relatives of patients with schizophrenia, and 24 healthy nonrelatives. Glutamate, glutamine, and GABA were measured cortically and subcortically in bilateral basal ganglia and occipital cortex. Patients with schizophrenia had reduced cortical GABA compared with healthy relatives and the combined sample of healthy relatives and healthy nonrelatives, suggesting that altered GABAergic systems in schizophrenia are associated with either disease state or medication effects. Reduced cortical glutamine relative to healthy control subjects was observed in patients with schizophrenia and the combined sample of healthy relatives and patients with schizophrenia, suggesting that altered glutamatergic metabolite levels are associated with illness liability. No group differences were found in the basal ganglia. Taken together, these findings are consistent with alterations in GABAergic and glutamatergic systems in patients with schizophrenia and provide novel insights into these systems in healthy relatives. Copyright © 2016 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

Activation of the TOR Signalling Pathway by Glutamine Regulates Insect Fecundity.

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Zhai, Yifan; Sun, Zhongxiang; Zhang, Jianqing; Kang, Kui; Chen, Jie; Zhang, Wenqing

2015-05-29

The target of rapamycin (TOR) positively controls cell growth in response to nutrients such as amino acids. However, research on the specific nutrients sensed by TOR is limited. Glutamine (Gln), a particularly important amino acid involved in metabolism in organisms, is synthesised and catalysed exclusively by glutamine synthetase (GS), and our previous studies have shown that Gln may regulate fecundity in vivo levels of the brown planthopper (BPH) Nilaparvata lugens. Until now, it has remained unclear whether Gln activates or inhibits the TOR signalling pathway. Here, we performed the combined analyses of iTRAQ (isobaric tags for relative and absolute quantification) and DGE (tag-based digital gene expression) data in N. lugens at the protein and transcript levels after GS RNAi, and we found that 52 pathways overlap, including the TOR pathway. We further experimentally demonstrate that Gln activates the TOR pathway by promoting the serine/threonine protein kinase AKT and inhibiting the 5'AMP-activated protein kinase AMPK phosphorylation activity in the pest. Furthermore, TOR regulates the fecundity of N. lugens probably by mediating vitellogenin (Vg) expression. This work is the first report that Gln activates the TOR pathway in vivo.

The ratio of acetate-to-glucose oxidation in astrocytes from a single 13C NMR spectrum of cerebral cortex.

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Marin-Valencia, Isaac; Hooshyar, M Ali; Pichumani, Kumar; Sherry, A Dean; Malloy, Craig R

2015-01-01

The (13) C-labeling patterns in glutamate and glutamine from brain tissue are quite different after infusion of a mixture of (13) C-enriched glucose and acetate. Two processes contribute to this observation, oxidation of acetate by astrocytes but not neurons, and preferential incorporation of α-ketoglutarate into glutamate in neurons, and incorporation of α-ketoglutarate into glutamine in astrocytes. The acetate:glucose ratio, introduced previously for analysis of a single (13) C NMR spectrum, provides a useful index of acetate and glucose oxidation in the brain tissue. However, quantitation of relative substrate oxidation at the cell compartment level has not been reported. A simple mathematical method is presented to quantify the ratio of acetate-to-glucose oxidation in astrocytes, based on the standard assumption that neurons do not oxidize acetate. Mice were infused with [1,2-(13) C]acetate and [1,6-(13) C]glucose, and proton decoupled (13) C NMR spectra of cortex extracts were acquired. A fit of those spectra to the model indicated that (13) C-labeled acetate and glucose contributed approximately equally to acetyl-CoA (0.96) in astrocytes. As this method relies on a single (13) C NMR spectrum, it can be readily applied to multiple physiologic and pathologic conditions. Differences in (13) C labeling of brain glutamate and glutamine have been attributed to metabolic compartmentation. The acetate:glucose ratio, introduced for description of a (13) C NMR (nuclear magnetic resonance) spectrum, is an index of glucose and acetate oxidation in brain tissue. A simple mathematical method is presented to quantify the ratio of acetate-to-glucose oxidation in astrocytes from a single NMR spectrum. As kinetic analysis is not required, the method is readily applicable to analysis of tissue extracts. α-KG = alpha-ketoglutarate; CAC = citric acid cycle; GLN = glutamine; GLU = glutamate. © 2014 International Society for Neurochemistry.

Combined glutamate and glutamine levels in pain-processing brain regions are associated with individual pain sensitivity.

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Zunhammer, Matthias; Schweizer, Lauren M; Witte, Vanessa; Harris, Richard E; Bingel, Ulrike; Schmidt-Wilcke, Tobias

2016-10-01

The relationship between glutamate and γ-aminobutyric acid (GABA) levels in the living human brain and pain sensitivity is unknown. Combined glutamine/glutamate (Glx), as well as GABA levels can be measured in vivo with single-voxel proton magnetic resonance spectroscopy. In this cross-sectional study, we aimed at determining whether Glx and/or GABA levels in pain-related brain regions are associated with individual differences in pain sensitivity. Experimental heat, cold, and mechanical pain thresholds were obtained from 39 healthy, drug-free individuals (25 men) according to the quantitative sensory testing protocol and summarized into 1 composite measure of pain sensitivity. The Glx levels were measured using point-resolved spectroscopy at 3 T, within a network of pain-associated brain regions comprising the insula, the anterior cingulate cortex, the mid-cingulate cortex, the dorsolateral prefrontal cortex, and the thalamus. GABA levels were measured using GABA-edited spectroscopy (Mescher-Garwood point-resolved spectroscopy) within the insula, the anterior cingulate cortex, and the mid-cingulate cortex. Glx and/or GABA levels correlated positively across all brain regions. Gender, weekly alcohol consumption, and depressive symptoms were significantly associated with Glx and/or GABA levels. A linear regression analysis including all these factors indicated that Glx levels pooled across pain-related brain regions were positively associated with pain sensitivity, whereas no appreciable relationship with GABA was found. In sum, we show that the levels of the excitatory neurotransmitter glutamate and its precursor glutamine across pain-related brain regions are positively correlated with individual pain sensitivity. Future studies will have to determine whether our findings also apply to clinical populations.

Molecular Mechanisms of Glutamine Synthetase Mutations that Lead to Clinically Relevant Pathologies.

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Benedikt Frieg

2016-02-01

Full Text Available Glutamine synthetase (GS catalyzes ATP-dependent ligation of ammonia and glutamate to glutamine. Two mutations of human GS (R324C and R341C were connected to congenital glutamine deficiency with severe brain malformations resulting in neonatal death. Another GS mutation (R324S was identified in a neurologically compromised patient. However, the molecular mechanisms underlying the impairment of GS activity by these mutations have remained elusive. Molecular dynamics simulations, free energy calculations, and rigidity analyses suggest that all three mutations influence the first step of GS catalytic cycle. The R324S and R324C mutations deteriorate GS catalytic activity due to loss of direct interactions with ATP. As to R324S, indirect, water-mediated interactions reduce this effect, which may explain the suggested higher GS residual activity. The R341C mutation weakens ATP binding by destabilizing the interacting residue R340 in the apo state of GS. Additionally, the mutation is predicted to result in a significant destabilization of helix H8, which should negatively affect glutamate binding. This prediction was tested in HEK293 cells overexpressing GS by dot-blot analysis: Structural stability of H8 was impaired through mutation of amino acids interacting with R341, as indicated by a loss of masking of an epitope in the glutamate binding pocket for a monoclonal anti-GS antibody by L-methionine-S-sulfoximine; in contrast, cells transfected with wild type GS showed the masking. Our analyses reveal complex molecular effects underlying impaired GS catalytic activity in three clinically relevant mutants. Our findings could stimulate the development of ATP binding-enhancing molecules by which the R324S mutant can be repaired extrinsically.

Cell Death-Autophagy Loop and Glutamate-Glutamine Cycle in Amyotrophic Lateral Sclerosis

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Shu Yuan

2017-07-01

Full Text Available Although we know that amyotrophic lateral sclerosis (ALS is correlated with the glutamate-mediated corticomotor neuronal hyperexcitability, detailed ALS pathology remains largely unexplained. While a number of drugs have been developed, no cure exists so far. Here, we propose a hypothesis of neuronal cell death—incomplete autophagy positive-feedback loop—and summarize the role of the neuron-astrocyte glutamate-glutamine cycle in ALS. The disruption of these two cycles might ideally retard ALS progression. Cerebrovascular injuries (such as multiple embolization sessions and strokes induce neuronal cell death and the subsequent autophagy. ALS impairs autophagosome-lysosome fusion and leads to magnified cell death. Trehalose rescues this impaired fusion step, significantly delaying the onset of the disease, although it does not affect the duration of the disease. Therefore, trehalose might be a prophylactic drug for ALS. Given that a major part of neuronal glutamate is converted from glutamine through neuronal glutaminase (GA, GA inhibitors may decrease the neuronal glutamate accumulation, and, therefore, might be therapeutic ALS drugs. Of these, Ebselen is the most promising one with strong antioxidant properties.

Double-blinded, placebo-controlled trial on intravenous L-alanyl-L-glutamine in the incidence of oral mucositis following chemoradiotherapy in patients with head-and-neck cancer

International Nuclear Information System (INIS)

Cerchietti, Leandro C.A.; Navigante, Alfredo H.; Lutteral, Maribel A.; Castro, Monica A.; Kirchuk, Ricardo; Bonomi, Marcelo; Cabalar, Maria Esther; Roth, Berta; Negretti, Graciela; Sheinker, Beatriz; Uchima, Patricia

2006-01-01

Purpose: We performed this double-blinded, placebo-controlled study to determine the safety and efficacy of L-alanyl-L-glutamine in the prevention of mucositis in patients with head-and-neck cancer. Methods and Materials: Thirty-two patients with head-and-neck cancer were treated with chemoradiotherapy (CRT) (radiotherapy daily up to 70 Gy plus cisplatin/5-fluoruracil once a week) and were asked to participate. Twenty-nine patients received the CRT schedule and were double-blindly assigned to receive either intravenous L-alanyl-L-glutamine 0.4 g/kg weight/day or an equal volume of saline (placebo) during chemotherapy days. Results: Fourteen patients received L-alanyl-L-glutamine and 15 received placebo. Mucositis was assessed by the Objective Mucositis Score (OMS) and the World Health Organization (WHO) grading system. There was a significant difference in incidence of mucositis developed in patients receiving placebo compared with those who received L-alanyl-L-glutamine (p = 0.035). The number of patients with severe objective mucositis (OMS >1.49) was higher in the placebo group compared with the L-alanyl-L-glutamine group (67% vs. 14%, p 0.007). L-alanyl-L-glutamine patients experienced less pain (three highest Numeric Rating Scale scores of 1.3/10 vs. 6.3/10 respectively, p = 0.008) and need for feeding tubes (14% vs. 60% respectively, p = 0.020) compared with placebo patients. No adverse effects related to the drug or the infusions were noted in either group. Conclusion: For patients with head-and-neck cancer receiving CRT, intravenous L-alanyl-L-glutamine may be an effective preventive measure to decrease the severity of mucositis

Mitochondrial Sirt3 supports cell proliferation by regulating glutamine-dependent oxidation in renal cell carcinoma

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Choi, Jieun; Koh, Eunjin; Lee, Yu Shin; Lee, Hyun-Woo; Kang, Hyeok Gu; Yoon, Young Eun; Han, Woong Kyu; Choi, Kyung Hwa; Kim, Kyung-Sup

2016-01-01

Clear cell renal carcinoma (RCC), the most common malignancy arising in the adult kidney, exhibits increased aerobic glycolysis and low mitochondrial respiration due to von Hippel-Lindau gene defects and constitutive hypoxia-inducible factor-α expression. Sirt3 is a major mitochondrial deacetylase that mediates various types of energy metabolism. However, the role of Sirt3 as a tumor suppressor or oncogene in cancer depends on cell types. We show increased Sirt3 expression in the mitochondrial fraction of human RCC tissues. Sirt3 depletion by lentiviral short-hairpin RNA, as well as the stable expression of the inactive mutant of Sirt3, inhibited cell proliferation and tumor growth in xenograft nude mice, respectively. Furthermore, mitochondrial pyruvate, which was used for oxidation in RCC, might be derived from glutamine, but not from glucose and cytosolic pyruvate, due to depletion of mitochondrial pyruvate carrier and the relatively high expression of malic enzyme 2. Depletion of Sirt3 suppressed glutamate dehydrogenase activity, leading to impaired mitochondrial oxygen consumption. Our findings suggest that Sirt3 plays a tumor-progressive role in human RCC by regulating glutamine-derived mitochondrial respiration, particularly in cells where mitochondrial usage of cytosolic pyruvate is severely compromised. -- Highlights: •Sirt3 is required for the maintenance of RCC cell proliferation. •Mitochondrial usage of cytosolic pyruvate is severely compromised in RCC. •Sirt3 supports glutamine-dependent oxidation in RCC.

Evaluating Factor XIII Specificity for Glutamine-Containing Substrates Using a MALDI-TOF Mass Spectrometry Assay

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Doiphode, Prakash G.; Malovichko, Marina V.; Mouapi, Kelly Njine; Maurer, Muriel C.

2014-01-01

Activated Factor XIII (FXIIIa) catalyzes the formation of γ-glutamyl-ε-lysyl cross-links within the fibrin blood clot network. Although several cross-linking targets have been identified, the characteristic features that define FXIIIa substrate specificity are not well understood. To learn more about how FXIIIa selects its targets, a matrix-assisted laser desorption ionization – time of flight mass spectrometry (MALDI-TOF MS) based assay was developed that could directly follow the consumption of a glutamine-containing substrate and the formation of a cross-linked product with glycine ethylester. This FXIIIa kinetics assay is no longer reliant on a secondary coupled reaction, on substrate labeling, or on detecting the final deacylation portion of the transglutaminase reaction. With the MALDI-TOF MS assay, glutamine-containing peptides derived from α2-antiplasmin, S. Aureus fibronectin binding protein A, and thrombin activatable fibrinolysis inhibitor were examined directly. Results suggest that the FXIIIa active site surface responds to changes in substrate residues following the reactive glutamine. The P-1 substrate position is sensitive to charge character and the P-2 and P-3 to the broad FXIIIa substrate specificity pockets. The more distant P-8 to P-11 region serves as a secondary substrate anchoring point. New knowledge on FXIIIa specificity may be used to design better substrates or inhibitors of this transglutaminase. PMID:24751466

Mitochondrial Sirt3 supports cell proliferation by regulating glutamine-dependent oxidation in renal cell carcinoma

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Choi, Jieun; Koh, Eunjin; Lee, Yu Shin; Lee, Hyun-Woo; Kang, Hyeok Gu [Department of Biochemistry and Molecular Biology, Brain Korea 21 PLUS Project for Medical Sciences, Institute of Genetic Science, Integrated Genomic Research Center for Metabolic Regulation, Yonsei University College of Medicine, Seoul 120-752 (Korea, Republic of); Yoon, Young Eun; Han, Woong Kyu [Department of Urology, Urological Science Institute, Yonsei University College of Medicine, Seoul 120-752 (Korea, Republic of); Choi, Kyung Hwa [Department of Urology, CHA Bundang Medical Center, CHA University, Seongnam 463-712 (Korea, Republic of); Kim, Kyung-Sup, E-mail: KYUNGSUP59@yuhs.ac [Department of Biochemistry and Molecular Biology, Brain Korea 21 PLUS Project for Medical Sciences, Institute of Genetic Science, Integrated Genomic Research Center for Metabolic Regulation, Yonsei University College of Medicine, Seoul 120-752 (Korea, Republic of)

2016-06-03

Clear cell renal carcinoma (RCC), the most common malignancy arising in the adult kidney, exhibits increased aerobic glycolysis and low mitochondrial respiration due to von Hippel-Lindau gene defects and constitutive hypoxia-inducible factor-α expression. Sirt3 is a major mitochondrial deacetylase that mediates various types of energy metabolism. However, the role of Sirt3 as a tumor suppressor or oncogene in cancer depends on cell types. We show increased Sirt3 expression in the mitochondrial fraction of human RCC tissues. Sirt3 depletion by lentiviral short-hairpin RNA, as well as the stable expression of the inactive mutant of Sirt3, inhibited cell proliferation and tumor growth in xenograft nude mice, respectively. Furthermore, mitochondrial pyruvate, which was used for oxidation in RCC, might be derived from glutamine, but not from glucose and cytosolic pyruvate, due to depletion of mitochondrial pyruvate carrier and the relatively high expression of malic enzyme 2. Depletion of Sirt3 suppressed glutamate dehydrogenase activity, leading to impaired mitochondrial oxygen consumption. Our findings suggest that Sirt3 plays a tumor-progressive role in human RCC by regulating glutamine-derived mitochondrial respiration, particularly in cells where mitochondrial usage of cytosolic pyruvate is severely compromised. -- Highlights: •Sirt3 is required for the maintenance of RCC cell proliferation. •Mitochondrial usage of cytosolic pyruvate is severely compromised in RCC. •Sirt3 supports glutamine-dependent oxidation in RCC.

Antioxidant properties of glutamine and its role in VEGF-Akt pathways in portal hypertension gastropathy.

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Marques, Camila; Licks, Francielli; Zattoni, Ingrid; Borges, Beatriz; de Souza, Luiz Eduardo Rizzo; Marroni, Claudio Augusto; Marroni, Norma Possa

2013-07-28

To investigate the effects of glutamine on oxidative/nitrosative stress and the vascular endothelial growth factor (VEGF)-Akt-endothelial nitric oxide synthase (eNOS) signaling pathway in an experimental model of portal hypertension induced by partial portal vein ligation (PPVL). Portal hypertension was induced by PPVL. The PPVL model consists of a partial obstruction of the portal vein, performed using a 20 G blunt needle as a guide, which is gently removed after the procedure. PPVL model was performed for 14 d beginning treatment with glutamine on the seventh day. On the fifteenth day, the mesenteric vein pressure was checked and the stomach was removed to test immunoreactivity and oxidative stress markers. We evaluated the expression and the immunoreactivity of proteins involved in the VEGF-Akt-eNOS pathway by Western blotting and immunohistochemical analysis. Oxidative stress was measured by quantification of the cytosolic concentration of thiobarbituric acid reactive substances (TBARS) as well as the levels of total glutathione (GSH), superoxide dismutase (SOD) activity, nitric oxide (NO) production and nitrotyrosine immunoreactivity. All data are presented as the mean ± SE. The production of TBARS and NO was significantly increased in PPVL animals. A reduction of SOD activity was detected in PPVL + G group. In the immunohistochemical analyses of nitrotyrosine, Akt and eNOS, the PPVL group exhibited significant increases, whereas decreases were observed in the PPVL + G group, but no difference in VEGF was detected between these groups. Western blotting analysis detected increased expression of phosphatidylinositol-3-kinase (PI3K), P-Akt and eNOS in the PPVL group compared with the PPVL + G group, which was not observed for the expression of VEGF when comparing these groups. Glutamine administration markedly alleviated oxidative/nitrosative stress, normalized SOD activity, increased levels of total GSH and blocked NO overproduction as well as the formation of

Metabolic Cooperation of Glucose and Glutamine Is Essential for the Lytic Cycle of Obligate Intracellular Parasite Toxoplasma gondii*

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Nitzsche, Richard; Zagoriy, Vyacheslav; Lucius, Richard; Gupta, Nishith

2016-01-01

Toxoplasma gondii is a widespread protozoan parasite infecting nearly all warm-blooded organisms. Asexual reproduction of the parasite within its host cells is achieved by consecutive lytic cycles, which necessitates biogenesis of significant energy and biomass. Here we show that glucose and glutamine are the two major physiologically important nutrients used for the synthesis of macromolecules (ATP, nucleic acid, proteins, and lipids) in T. gondii, and either of them is sufficient to ensure the parasite survival. The parasite can counteract genetic ablation of its glucose transporter by increasing the flux of glutamine-derived carbon through the tricarboxylic acid cycle and by concurrently activating gluconeogenesis, which guarantee a continued biogenesis of ATP and biomass for host-cell invasion and parasite replication, respectively. In accord, a pharmacological inhibition of glutaminolysis or oxidative phosphorylation arrests the lytic cycle of the glycolysis-deficient mutant, which is primarily a consequence of impaired invasion due to depletion of ATP. Unexpectedly, however, intracellular parasites continue to proliferate, albeit slower, notwithstanding a simultaneous deprivation of glucose and glutamine. A growth defect in the glycolysis-impaired mutant is caused by a compromised synthesis of lipids, which cannot be counterbalanced by glutamine but can be restored by acetate. Consistently, supplementation of parasite cultures with exogenous acetate can amend the lytic cycle of the glucose transport mutant. Such plasticity in the parasite's carbon flux enables a growth-and-survival trade-off in assorted nutrient milieus, which may underlie the promiscuous survival of T. gondii tachyzoites in diverse host cells. Our results also indicate a convergence of parasite metabolism with cancer cells. PMID:26518878

Expression of glutamine transporter isoforms in cerebral cortex of rats with chronic hepatic encephalopathy

DEFF Research Database (Denmark)

Leke, Renata; Escobar, Thayssa D.C.; Rama Rao, Kakulavarapu V.

2015-01-01

Hepatic encephalopathy (HE) is a neuropsychiatric disorder that occurs due to acute and chronic liver diseases, the hallmark of which is the increased levels of ammonia and subsequent alterations in glutamine synthesis, i.e. conditions associated with the pathophysiology of HE. Under physiological...

Deprive to kill: Glutamine closes the gate to anticancer monocarboxylic drugs

OpenAIRE

Cardaci, Simone; Ciriolo, Maria Rosa

2012-01-01

Killing properties of antitumor drugs can be enhanced by strategies targeting biochemical adaptations of cancer cells. Recently, we reported that depriving cancer cells of glutamine is a feasible approach to enhance antitumor effects of the alkylating analog of pyruvic acid, 3-bromopyruvate, which rely on the induction of autophagic cell death by metabolic-oxidative stress. 3-bromopyruvate chemopotentiation is the result of its increased intracellular uptake mediated by the monocarboxylate tr...

Nano-nutrition of chicken embryos. The effect of silver nanoparticles and glutamine on molecular responses, and the morphology of pectoral muscle

DEFF Research Database (Denmark)

Sawosz, Filip; Pineda, Lane Manalili; Hotowy, Anna Malgorzata

2012-01-01

Background: It has been demonstrated that concentrations of certain amino acids in the egg, in late-term embryos, are not sufficient to fully support embryonic development. One of the methods to assure an adequate nutrient content in the egg is in ovo administration of nutrients, which increases...... and vascular endothelial growth factor. We have therefore tested if silver nanoparticles can affect muscle development of chicken embryos and, furthermore, if they can be used in in ovo nutrition as carriers of nutrients e.g. glutamine into muscle cells. Methods: 160 broiler eggs were randomly divided...... into the control group (Control) without injection and injected groups with hydrocolloids of nanoparticles of silver (Nano-Ag), glutamine (Glu) and the complex of nanoparticles of silver and glutamine (Nano-Ag/Glu). The embryos were evaluated on day 20 of incubation. Samples of the breast muscles were collected...

Inhibition of glutamine synthesis induces glutamate dehydrogenase-dependent ammonia fixation into alanine in co-cultures of astrocytes and neurons

DEFF Research Database (Denmark)

Dadsetan, Sherry; Bak, Lasse Kristoffer; Sørensen, Michael

2011-01-01

study it was investigated if the glutamine synthetase (GS) inhibitor methionine sulfoximine (MSO) would enhance alanine synthesis by blocking the GS-dependent ammonia scavenging process. Hence, co-cultures of neurons and astrocytes were incubated for 2.5h with [U-(13)C]glucose to monitor de novo......It has been previously demonstrated that ammonia exposure of neurons and astrocytes in co-culture leads to net synthesis not only of glutamine but also of alanine. The latter process involves the concerted action of glutamate dehydrogenase (GDH) and alanine aminotransferase (ALAT). In the present...

Separation and determination of acetyl-glutamine enantiomers by HPLC–MS and its application in pharmacokinetic study

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Xiaoxiao Zhang

2017-10-01

Full Text Available A high-performance liquid chromatography coupled with mass spectrometry (HPLC–MS method was established for the separation and determination of acetyl-glutamine enantiomers (acetyl-L-glutamine and acetyl-D-glutamine simultaneously. Baseline separation was achieved on Chiralpak AD-H column (250 mm × 4.6 mm, 5 µm. n-Hexane (containing 0.1% acetic acid and ethanol (75:25, v/v were used as mobile phase at a flow rate of 0.6 mL/min. The detection was operated in the negative ion mode with an ESI source. [M-H]− m/z 187.0540 for enantiomers and [M-H]− m/z 179.0240 for aspirin (IS were selected as detecting ions. The linear range of the calibration curve for each enantiomer was 0.05–40 µg/mL. The precision of this method at concentrations of 0.5–20 µg/mL was within 7.23%, and the accuracy was 99.81%–107.81%. The precision at LOQ (0.05 µg/mL was between 16.28% and 17.56%, which was poor than that at QC levels. The average extraction recovery was higher than 85% for both enantiomers at QC levels. The pharmacokinetics of enantiomers was found to be stereoselective. There was not chiral inversion in vivo or in vitro between enantiomers.

Effects of Glutamine and Alanine Supplementation on Central Fatigue Markers in Rats Submitted to Resistance Training

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Audrey Yule Coqueiro

2018-01-01

Full Text Available Recent evidence suggests that increased brain serotonin synthesis impairs performance in high-intensity intermittent exercise and specific amino acids may modulate this condition, delaying fatigue. This study investigated the effects of glutamine and alanine supplementation on central fatigue markers in rats submitted to resistance training (RT. Wistar rats were distributed in: sedentary (SED, trained (CON, trained and supplemented with alanine (ALA, glutamine and alanine in their free form (G + A, or as dipeptide (DIP. Trained groups underwent a ladder-climbing exercise for eight weeks, with progressive loads. In the last 21 days, supplementations were offered in water with a 4% concentration. Albeit without statistically significance difference, RT decreased liver glycogen, and enhanced the concentrations of plasma glucose, free fatty acids (FFA, hypothalamic serotonin, and ammonia in muscle and the liver. Amino acids affected fatigue parameters depending on the supplementation form. G + A prevented the muscle ammonia increase by RT, whereas ALA and DIP augmented ammonia and glycogen concentrations in muscle. DIP also increased liver ammonia. ALA and G + A reduced plasma FFA, whereas DIP increased this parameter, free tryptophan/total tryptophan ratio, hypothalamic serotonin, and the serotonin/dopamine ratio. The supplementations did not affect physical performance. In conclusion, glutamine and alanine may improve or impair central fatigue markers depending on their supplementation form.

Metabolic Cooperation of Glucose and Glutamine Is Essential for the Lytic Cycle of Obligate Intracellular Parasite Toxoplasma gondii.

Science.gov (United States)

Nitzsche, Richard; Zagoriy, Vyacheslav; Lucius, Richard; Gupta, Nishith

2016-01-01

Toxoplasma gondii is a widespread protozoan parasite infecting nearly all warm-blooded organisms. Asexual reproduction of the parasite within its host cells is achieved by consecutive lytic cycles, which necessitates biogenesis of significant energy and biomass. Here we show that glucose and glutamine are the two major physiologically important nutrients used for the synthesis of macromolecules (ATP, nucleic acid, proteins, and lipids) in T. gondii, and either of them is sufficient to ensure the parasite survival. The parasite can counteract genetic ablation of its glucose transporter by increasing the flux of glutamine-derived carbon through the tricarboxylic acid cycle and by concurrently activating gluconeogenesis, which guarantee a continued biogenesis of ATP and biomass for host-cell invasion and parasite replication, respectively. In accord, a pharmacological inhibition of glutaminolysis or oxidative phosphorylation arrests the lytic cycle of the glycolysis-deficient mutant, which is primarily a consequence of impaired invasion due to depletion of ATP. Unexpectedly, however, intracellular parasites continue to proliferate, albeit slower, notwithstanding a simultaneous deprivation of glucose and glutamine. A growth defect in the glycolysis-impaired mutant is caused by a compromised synthesis of lipids, which cannot be counterbalanced by glutamine but can be restored by acetate. Consistently, supplementation of parasite cultures with exogenous acetate can amend the lytic cycle of the glucose transport mutant. Such plasticity in the parasite's carbon flux enables a growth-and-survival trade-off in assorted nutrient milieus, which may underlie the promiscuous survival of T. gondii tachyzoites in diverse host cells. Our results also indicate a convergence of parasite metabolism with cancer cells. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Hyperhydricity Phenomena Problem in Embryonic Callus of Date Palm, Solving by Glutamine and NH4+: No3- Ratio in Basal Nutrient Medium

International Nuclear Information System (INIS)

El-Dawayaty, M.M.; Zayed, Z.E.; Abdel-Gelil, L.M.

2012-01-01

Hyperhydricity is a serious problem faced in vitro date palm propagation which directly effects on the commercial production. So we try to solve this problem by studying, the effect of glutamine as the organic source of nitrogen and NH 4 + :NO 3- ratio as the inorganic source of nitrogen to decrease hyperhydricity phenomena and to produce normal somatic embryos of date palm cv. Gondila.Vitrified embryonic callus were inoculated on MS basal nutrient medium modified with glutamine levels and NH 4 + : NO 3 - ratio. Five concentration ratios of NH 4 : NO 3 (10:15, 15:10, 0:20, 20:0, 0:0 ml/l) were used with 0.1 mg/l NAA for 8 weeks throughout 2 recultures. There were gradually increasing in the percentage of vitrified embryonic callus differentiation to normal somatic embryos by increasing glutamine levels from 0.0 to 400 mg/l. Glutamine at the lowest level (50 mg/l) increased significantly the number of vitrified somatic embryos. Ammonium as the sole source of N resulted in depression in somatic embryos differentiation and escalated the frequency of hyperhydricity whereas,if nitrate was used as the sole N source, somatic embryos good quality were produced and hyperhydricity was eliminated

A randomised trial of enteral glutamine supplementation for very preterm children showed no beneficial or adverse long-term neurodevelopmental outcomes.

Science.gov (United States)

Twilhaar, E Sabrina; de Kieviet, Jorrit F; Oosterlaan, Jaap; van Elburg, Ruurd M

2018-04-01

This study evaluated the long-term effects of enteral glutamine supplementation on neurodevelopmental outcomes of a Dutch cohort of very preterm children at 13 years of age. The cohort was enrolled in a randomised placebo-controlled trial between 2001 and 2003 in which infants received glutamine- or alanine-supplemented enteral nutrition during the first month of life. Participants were invited for follow-up at a mean age of 13.30 years. Motor, neurocognitive, academic and behavioural outcomes were assessed in 61 children. No differences were found between the groups regarding motor, intellectual, academic and behavioural functioning. Forward span visuospatial working memory performance was better in the controls (crude/adjusted model: d = 0.67/0.64, p = 0.02/0.02), but no difference was found for backward span. After the data were adjusted for confounders, the groups differed regarding parent-rated attention (crude/adjusted model: d = 0.47/0.73, p = 0.07/0.003), but both groups scored within the normal range. This was the first study on the long-term effects of enteral glutamine supplementation on the neurodevelopmental outcomes of very preterm children. Our study provided no evidence that enteral glutamine supplementation had any beneficial or adverse effects on the children's motor, neurocognitive, academic and behavioural outcomes at 13 years of age. ©2017 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

Lack of cardioprotection from metabolic support with glutamine or glutamate in a porcine coronary occlusion model

DEFF Research Database (Denmark)

Kristensen, Jens; Mæng, Michael; Mortensen, Ulrik

2005-01-01

vascular resistance, while glutamate preserved cardiac output during infusion. CONCLUSION: Substrate supplementation with the anaplerotic precursors glutamine and glutamate is ineffective as adjunctive therapy for severe myocardial ischemia. Beneficial effects documented in less complex experimental...

Noncoding RNA of Glutamine Synthetase I Modulates Antibiotic Production in Streptomyces coelicolor A3(2)

NARCIS (Netherlands)

D'Alia, Davide; Nieselt, Kay; Steigele, Stephan; Mueller, Jonas; Verburg, Ilse; Takano, Eriko; Alia, Davide D’; Müller, Jonas

Overexpression of antisense chromosomal cis-encoded noncoding RNAss (ncRNAs) in glutamine synthetase I resulted in a decrease in growth, protein synthesis, and antibiotic production in Streptomyces coelicolor. In addition, we predicted 3,597 cis-encoded ncRNAs and validated 13 of them

Cyclization of the N-Terminal X-Asn-Gly Motif during Sample Preparation for Bottom-Up Proteomics

DEFF Research Database (Denmark)

Zhang, Xumin; Højrup, Peter

2010-01-01

We, herein, report a novel -17 Da peptide modification corresponding to an N-terminal cyclization of peptides possessing the N-terminal motif of X-Asn-Gly. The cyclization occurs spontaneously during sample preparation for bottom-up proteomics studies. Distinct from the two well-known N-terminal ......We, herein, report a novel -17 Da peptide modification corresponding to an N-terminal cyclization of peptides possessing the N-terminal motif of X-Asn-Gly. The cyclization occurs spontaneously during sample preparation for bottom-up proteomics studies. Distinct from the two well-known N......-terminal cyclizations, cyclization of N-terminal glutamine and S-carbamoylmethylcysteine, it is dependent on pH instead of [NH(4)(+)]. The data set from our recent study on large-scale N(α)-modified peptides revealed a sequence requirement for the cyclization event similar to the well-known deamidation of Asn to iso...

Comprehensive characterization of glutamine synthetase-mediated selection for the establishment of recombinant CHO cells producing monoclonal antibodies

DEFF Research Database (Denmark)

Noh, Soo Min; Shin, Seunghyeon; Min Lee, Gyun

2018-01-01

To characterize a glutamine synthetase (GS)-based selection system, monoclonal antibody (mAb) producing recombinant CHO cell clones were generated by a single round of selection at various methionine sulfoximine (MSX) concentrations (0, 25, and 50 μM) using two different host cell lines (CHO-K1...... and GS-knockout CHO). Regardless of the host cell lines used, the clones selected at 50 μM MSX had the lowest average specific growth rate and the highest average specific production rates of toxic metabolic wastes, lactate and ammonia. Unlike CHO-K1, high producing clones could be generated...... in the absence of MSX using GS-knockout CHO with an improved selection stringency. Regardless of the host cell lines used, the clones selected at various MSX concentrations showed no significant difference in the GS, heavy chain, and light chain gene copies (P > 0.05). Furthermore, there was no correlation...

Interactions of MK-801 with glutamate-, glutamine- and methamphetamine-evoked release of [3H]dopamine from striatal slices

International Nuclear Information System (INIS)

Bowyer, J.F.; Scallet, A.C.; Holson, R.R.; Lipe, G.W.; Slikker, W. Jr.; Ali, S.F.

1991-01-01

The interactions of MK-801 [(+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d] cyclohepten-5,10-imine], glutamate and glutamine with methamphetamine (METH)-evoked release of [ 3 H]dopamine were assessed in vitro to determine whether MK-801 inhibition of METH neurotoxicity might be mediated presynaptically, and to evaluate the effects of glutamatergic stimulation on METH-evoked dopamine release. MK-801 inhibition of glutamate- or METH-evoked dopamine release might reduce synaptic dopamine levels during METH exposure and decrease the formation of 6-hydroxydopamine or other related neurotoxins. Without Mg 2+ present, 40 microM and 1 mM glutamate evoked a N-methyl-D-aspartate receptor-mediated [ 3 H]dopamine and [ 3 H]metabolite (tritium) release of 3 to 6 and 12 to 16% of total tritium stores, respectively, from striatal slices. With 1.50 mM Mg 2+ present, 10 mM glutamate alone or in combination with the dopamine uptake blocker nomifensine released only 2.1 or 4.2%, respectively, of total tritium stores, and release was only partially dependent on N-methyl-D-aspartate-type glutamate receptors. With or without 1.50 mM Mg 2+ present, 0.5 or 5 microM METH evoked a substantial release of tritium (5-8 or 12-21% of total stores, respectively). METH-evoked dopamine release was not affected by 5 microM MK-801 but METH-evoked release was additive with glutamate-evoked release. Without Mg 2+ present, 1 mM glutamine increased glutamate release and induced the release of [ 3 H]dopamine and metabolites. Both 0.5 and 5 microM METH also increased tritium release with 1 mM glutamine present. When striatal slices were exposed to 5 microM METH this glutamine-evoked release of glutamate was increased more than 50%

Hypoxia-Like Signatures Induced by BCR-ABL Potentially Alter the Glutamine Uptake for Maintaining Oxidative Phosphorylation.

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Pallavi Sontakke

Full Text Available The Warburg effect is probably the most prominent metabolic feature of cancer cells, although little is known about the underlying mechanisms and consequences. Here, we set out to study these features in detail in a number of leukemia backgrounds. The transcriptomes of human CB CD34+ cells transduced with various oncogenes, including BCR-ABL, MLL-AF9, FLT3-ITD, NUP98-HOXA9, STAT5A and KRASG12V were analyzed in detail. Our data indicate that in particular BCR-ABL, KRASG12V and STAT5 could impose hypoxic signaling under normoxic conditions. This coincided with an upregulation of glucose importers SLC2A1/3, hexokinases and HIF1 and 2. NMR-based metabolic profiling was performed in CB CD34+ cells transduced with BCR-ABL versus controls, both cultured under normoxia and hypoxia. Lactate and pyruvate levels were increased in BCR-ABL-expressing cells even under normoxia, coinciding with enhanced glutaminolysis which occurred in an HIF1/2-dependent manner. Expression of the glutamine importer SLC1A5 was increased in BCR-ABL+ cells, coinciding with an increased susceptibility to the glutaminase inhibitor BPTES. Oxygen consumption rates also decreased upon BPTES treatment, indicating a glutamine dependency for oxidative phosphorylation. The current study suggests that BCR-ABL-positive cancer cells make use of enhanced glutamine metabolism to maintain TCA cell cycle activity in glycolytic cells.

Deletion of Type I glutamine synthetase deregulates nitrogen metabolism and increases ethanol production in Clostridium thermocellum

Energy Technology Data Exchange (ETDEWEB)

Rydzak, Thomas [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Biosciences Division, BioEnergy Science Center; Garcia, David [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Biosciences Division, BioEnergy Science Center; Stevenson, David M. [Univ. of Wisconsin, Madison, WI (United States). Dept. of Bacteriology; Sladek, Margaret [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Biosciences Division, BioEnergy Science Center; Klingeman, Dawn M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Biosciences Division, BioEnergy Science Center; Holwerda, Evert K. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Biosciences Division; Dartmouth College, Hanover, NH (United States). Thayer School of Engineering; Amador-Noguez, Daniel [Univ. of Wisconsin, Madison, WI (United States). Dept. of Bacteriology; Brown, Steven D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Biosciences Division, BioEnergy Science Center; Guss, Adam M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Biosciences Division, BioEnergy Science Center

2017-05-01

Clostridium thermocellum rapidly deconstructs cellulose and ferments resulting hydrolysis products into ethanol and other products, and is thus a promising platform organism for the development of cellulosic biofuel production via consolidated bioprocessing. And while recent metabolic engineering strategies have targeted eliminating canonical fermentation products (acetate, lactate, formate, and H₂), C. thermocellum also secretes amino acids, which has limited ethanol yields in engineered strains to approximately 70% of the theoretical maximum. To decrease amino acid secretion, we attempted to reduce ammonium assimilation by deleting the Type I glutamine synthetase (glnA) in C. thermocellum. Deletion of glnA reduced levels of secreted valine and total amino acids by 53% and 44% respectively, and increased ethanol yields by 53%. RNA-seq analysis revealed that genes encoding the RNF-complex were more highly expressed in ΔglnA and may have a role in improving NADH-availability for ethanol production. While a significant up-regulation of genes involved in nitrogen assimilation and urea uptake suggested that deletion of glnA induces a nitrogen starvation response, metabolomic analysis showed an increase in intracellular glutamine and α-ketoglutarate levels indicative of nitrogen-rich conditions. Here, we propose that deletion of glnA causes deregulation of nitrogen metabolism, leading to overexpression of nitrogen metabolism genes and, in turn, elevated glutamine/α-ketoglutarate levels. Here we demonstrate that perturbation of nitrogen assimilation is a promising strategy to redirect flux from the production of nitrogenous compounds toward biofuels in C. thermocellum.

Antagonizing Bcl-2 family members sensitizes neuroblastoma and Ewing's sarcoma to an inhibitor of glutamine metabolism.

Directory of Open Access Journals (Sweden)

Rachelle R Olsen

Full Text Available Neuroblastomas (NBL and Ewing's sarcomas (EWS together cause 18% of all pediatric cancer deaths. Though there is growing interest in targeting the dysregulated metabolism of cancer as a therapeutic strategy, this approach has not been fully examined in NBL and EWS. In this study, we first tested a panel of metabolic inhibitors and identified the glutamine antagonist 6-diazo-5-oxo-L-norleucine (DON as the most potent chemotherapeutic across all NBL and EWS cell lines tested. Myc, a master regulator of metabolism, is commonly overexpressed in both of these pediatric malignancies and recent studies have established that Myc causes cancer cells to become "addicted" to glutamine. We found DON strongly inhibited tumor growth of multiple tumor lines in mouse xenograft models. In vitro, inhibition of caspases partially reversed the effects of DON in high Myc expressing cell lines, but not in low Myc expressing lines. We further showed that induction of apoptosis by DON in Myc-overexpressing cancers is via the pro-apoptotic factor Bax. To relieve inhibition of Bax, we tested DON in combination with the Bcl-2 family antagonist navitoclax (ABT-263. In vitro, this combination caused an increase in DON activity across the entire panel of cell lines tested, with synergistic effects in two of the N-Myc amplified neuroblastoma cell lines. Our study supports targeting glutamine metabolism to treat Myc overexpressing cancers, such as NBL and EWS, particularly in combination with Bcl-2 family antagonists.

Glutamine methylation in histone H2A is an RNA-polymerase-I-dedicated modification

DEFF Research Database (Denmark)

Tessarz, Peter; Santos-Rosa, Helena; Robson, Sam C

2014-01-01

as the methyltransferase in yeast and demonstrate that fibrillarin is the orthologue enzyme in human cells. Glutamine methylation of H2A is restricted to the nucleolus. Global analysis in yeast, using an H2AQ105me-specific antibody, shows that this modification is exclusively enriched over the 35S ribosomal DNA...

Office-Based Point of Care Testing (IgA/IgG-Deamidated Gliadin Peptide) for Celiac Disease.

Science.gov (United States)

Lau, Michelle S; Mooney, Peter D; White, William L; Rees, Michael A; Wong, Simon H; Hadjivassiliou, Marios; Green, Peter H R; Lebwohl, Benjamin; Sanders, David S

2018-06-19

Celiac disease (CD) is common yet under-detected. A point of care test (POCT) may improve CD detection. We aimed to assess the diagnostic performance of an IgA/IgG-deamidated gliadin peptide (DGP)-based POCT for CD detection, patient acceptability, and inter-observer variability of the POCT results. From 2013-2017, we prospectively recruited patients referred to secondary care with gastrointestinal symptoms, anemia and/or weight loss (group 1); and patients with self-reported gluten sensitivity with unknown CD status (group 2). All patients had concurrent POCT, IgA-tissue transglutaminase (IgA-TTG), IgA-endomysial antibodies (IgA-EMA), total IgA levels, and duodenal biopsies. Five hundred patients completed acceptability questionnaires, and inter-observer variability of the POCT results was compared among five clinical staff for 400 cases. Group 1: 1000 patients, 58.5% female, age 16-91, median age 57. Forty-one patients (4.1%) were diagnosed with CD. The sensitivities of the POCT, IgA-TTG, and IgA-EMA were 82.9, 78.1, and 70.7%; the specificities were 85.4, 96.3, and 99.8%. Group 2: 61 patients, 83% female; age 17-73, median age 35. The POCT had 100% sensitivity and negative predictive value in detecting CD in group 2. Most patients preferred the POCT to venepuncture (90.4% vs. 2.8%). There was good inter-observer agreement on the POCT results with a Fleiss Kappa coefficient of 0.895. The POCT had comparable sensitivities to serology, and correctly identified all CD cases in a gluten sensitive cohort. However, its low specificity may increase unnecessary investigations. Despite its advantage of convenience and rapid results, it may not add significant value to case finding in an office-based setting.

Mitochondrial citrulline synthesis from ammonia and glutamine in the liver of ureogenic air-breathing catfish, Clarias batrachus (Linnaeus).

Science.gov (United States)

Kharbuli, Zaiba Y; Biswas, Kuheli; Saha, Nirmalendu

2007-12-01

The possible synthesis of citrulline, a rate limiting step for urea synthesis via the ornithine-urea cycle (OUC) in teleosts was tested both in the presence of ammonia and glutamine as nitrogen-donating substrates by the isolated liver mitochondria of ureogenic air-breathing walking catfish, C. batrachus. Both ammonia and glutamine could be used as nitrogen-donating substrates for the synthesis of citrulline by the isolated liver mitochondria, since the rate of citrulline synthesis was almost equal in presence of both the substrates. The citrulline synthesis by the isolated liver mitochondria requires succinate at a concentration of 0.1 mM as an energy source, and also requires the involvement of intramitochondrial carbonic anhydrase activity for supplying HCO3 as another substrate for citrulline synthesis. The rate of citrulline synthesis was further stimulated significantly by the isolated liver mitochondria of the fish after pre-exposure to 25 mM NH4Cl for 7 days. Due to possessing this biochemical adaptational strategy leading to the amelioration of ammonia toxicity mainly by channeling ammonia directly and/or via the formation of glutamine to the OUC, this air-breathing catfish could succeed in surviving in high external ammonia, which it faces in its natural habitat in certain seasons of the year.

Combined enteral infusion of glutamine, carbohydrates, and antioxidants modulates gut protein metabolism in humans.

Science.gov (United States)

Coëffier, Moïse; Claeyssens, Sophie; Lecleire, Stéphane; Leblond, Jonathan; Coquard, Aude; Bôle-Feysot, Christine; Lavoinne, Alain; Ducrotté, Philippe; Déchelotte, Pierre

2008-11-01

Available data suggest that nutrients can affect intestinal protein metabolism, which contributes to the regulation of gut barrier function. We aimed to assess whether an oral nutritional supplement (ONS) containing glutamine (as the dipeptide Ala-Gln), carbohydrates, and antioxidants would modulate duodenal protein metabolism in healthy humans. Thirty healthy control subjects were included and, over a period of 5 h, received by nasogastric tube either saline or ONS providing 11.7 kcal/kg as 0.877 g Ala-Gln/kg, 3.9 g carbohydrates/kg, and antioxidants (29.25 mg vitamin C/kg, 9.75 mg vitamin E/kg, 195 microg beta-carotene/kg, 5.85 mg Se/kg, and 390 microg Zn/kg) or glutamine (0.585 g/kg, 2.34 kcal/kg). Simultaneously, a continuous intravenous infusion of l-[1-(13)C]-leucine was done until endoscopy. Leucine enrichment was assessed by using gas chromatography-mass spectrometric analysis, and mucosal fractional synthesis rate was calculated by using intracellular amino acid enrichment as precursor. Mucosal proteolytic pathways were also evaluated. ONS infusion resulted in a doubling increase (P < 0.01) of duodenal fractional synthesis rate and a significant (P < 0.05) decrease in cathepsin D-mediated proteolysis compared with saline, whereas proteasome and Ca(2+)-dependent activities were unaffected. ONS infusion significantly (P < 0.01) decreased duodenal glutathione but not glutathione disulfide concentrations or the ratio of glutathione to glutathione disulfide. Insulinemia increased after ONS infusion, whereas plasma essential amino acids decreased. Infusion of glutamine alone did not reproduce ONS effects. ONS infusion improves duodenal protein balance in healthy humans. Further investigations are needed to study the origin of these effects and to evaluate ONS supply in stressed persons.

Time-resolved transcriptome analysis of Bacillus subtilis responding to valine, glutamate, and glutamine.

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Bang-Ce Ye

Full Text Available Microorganisms can restructure their transcriptional output to adapt to environmental conditions by sensing endogenous metabolite pools. In this paper, an Agilent customized microarray representing 4,106 genes was used to study temporal transcript profiles of Bacillus subtilis in response to valine, glutamate and glutamine pulses over 24 h. A total of 673, 835, and 1135 amino-acid-regulated genes were identified having significantly changed expression at one or more time points in response to valine, glutamate, and glutamine, respectively, including genes involved in cell wall, cellular import, metabolism of amino-acids and nucleotides, transcriptional regulation, flagellar motility, chemotaxis, phage proteins, sporulation, and many genes of unknown function. Different amino acid treatments were compared in terms of both the global temporal profiles and the 5-minute quick regulations, and between-experiment differential genes were identified. The highlighted genes were analyzed based on diverse sources of gene functions using a variety of computational tools, including T-profiler analysis, and hierarchical clustering. The results revealed the common and distinct modes of action of these three amino acids, and should help to elucidate the specific signaling mechanism of each amino acid as an effector.

Glutamine synthetase in Medicago truncatula, unveiling new secrets of a very old enzyme

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Ana Rita Seabra

2015-07-01

Full Text Available Glutamine Synthetase (GS catalyses the first step at which nitrogen is brought into cellular metabolism and is also involved in the reassimilation of ammonium released by a number of metabolic pathways. Due to its unique position in plant nitrogen metabolism, GS plays essential roles in all aspects of plant development, from germination to senescence, and is a key component of nitrogen use efficiency (NUE and plant yield. Understanding the mechanisms regulating GS activity is therefore of utmost importance and a great effort has been dedicated to understand how GS is regulated in different plant species. The present review summarizes exciting recent developments concerning the structure and regulation of glutamine synthetase isoenzymes, using the model legume Medicago truncatula. These include the understanding of the structural determinants of both the cytosolic and plastid located isoenzymes, the existence of a seed-specific GS gene unique to M. truncatula and closely related species and the discovery that GS isoenzymes are regulated by nitric oxide at the post-translational level. The data is discussed and integrated with the potential roles of the distinct GS isoenzymes within the whole plant context.

Glutamine supplementation of parenteral nutrition does not improve intestinal permeability, nitrogen balance, or outcome in newborns and infants undergoing digestive-tract surgery: results from a double-blind, randomized, controlled trial

NARCIS (Netherlands)

E.W. Steyerberg (Ewout); F.W.J. Hazebroek (Frans); M. Mourik; G.J.J.M. Borsboom (Gerard); T. Rietveld (Trinet); J.G.M. Huijmans (Jan); D. Tibboel (Dick); M.J.I.J. Albers (Marcel)

2005-01-01

textabstractOBJECTIVE: To assess the effect of isocaloric isonitrogenous parenteral glutamine supplementation on intestinal permeability and nitrogen loss in newborns and infants after major digestive-tract surgery. SUMMARY BACKGROUND DATA: Glutamine supplementation in critically

Direct Correlation between Motile Behavior and Protein Abundance in Single Cells.

Directory of Open Access Journals (Sweden)

Yann S Dufour

2016-09-01

Full Text Available Understanding how stochastic molecular fluctuations affect cell behavior requires the quantification of both behavior and protein numbers in the same cells. Here, we combine automated microscopy with in situ hydrogel polymerization to measure single-cell protein expression after tracking swimming behavior. We characterized the distribution of non-genetic phenotypic diversity in Escherichia coli motility, which affects single-cell exploration. By expressing fluorescently tagged chemotaxis proteins (CheR and CheB at different levels, we quantitatively mapped motile phenotype (tumble bias to protein numbers using thousands of single-cell measurements. Our results disagreed with established models until we incorporated the role of CheB in receptor deamidation and the slow fluctuations in receptor methylation. Beyond refining models, our central finding is that changes in numbers of CheR and CheB affect the population mean tumble bias and its variance independently. Therefore, it is possible to adjust the degree of phenotypic diversity of a population by adjusting the global level of expression of CheR and CheB while keeping their ratio constant, which, as shown in previous studies, confers functional robustness to the system. Since genetic control of protein expression is heritable, our results suggest that non-genetic diversity in motile behavior is selectable, supporting earlier hypotheses that such diversity confers a selective advantage.

Crystal structures of mammalian glutamine synthetases illustrate substrate-induced conformational changes and provide opportunities for drug and herbicide design.

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Krajewski, Wojciech W; Collins, Ruairi; Holmberg-Schiavone, Lovisa; Jones, T Alwyn; Karlberg, Tobias; Mowbray, Sherry L

2008-01-04

Glutamine synthetase (GS) catalyzes the ligation of glutamate and ammonia to form glutamine, with concomitant hydrolysis of ATP. In mammals, the activity eliminates cytotoxic ammonia, at the same time converting neurotoxic glutamate to harmless glutamine; there are a number of links between changes in GS activity and neurodegenerative disorders, such as Alzheimer's disease. In plants, because of its importance in the assimilation and re-assimilation of ammonia, the enzyme is a target of some herbicides. GS is also a central component of bacterial nitrogen metabolism and a potential drug target. Previous studies had investigated the structures of bacterial and plant GSs. In the present publication, we report the first structures of mammalian GSs. The apo form of the canine enzyme was solved by molecular replacement and refined at a resolution of 3 A. Two structures of human glutamine synthetase represent complexes with: a) phosphate, ADP, and manganese, and b) a phosphorylated form of the inhibitor methionine sulfoximine, ADP and manganese; these structures were refined to resolutions of 2.05 A and 2.6 A, respectively. Loop movements near the active site generate more closed forms of the eukaryotic enzymes when substrates are bound; the largest changes are associated with the binding of the nucleotide. Comparisons with earlier structures provide a basis for the design of drugs that are specifically directed at either human or bacterial enzymes. The site of binding the amino acid substrate is highly conserved in bacterial and eukaryotic GSs, whereas the nucleotide binding site varies to a much larger degree. Thus, the latter site offers the best target for specific drug design. Differences between mammalian and plant enzymes are much more subtle, suggesting that herbicides targeting GS must be designed with caution.

Deletion of Type I glutamine synthetase deregulates nitrogen metabolism and increases ethanol production in Clostridium thermocellum.

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Rydzak, Thomas; Garcia, David; Stevenson, David M; Sladek, Margaret; Klingeman, Dawn M; Holwerda, Evert K; Amador-Noguez, Daniel; Brown, Steven D; Guss, Adam M

2017-05-01

Clostridium thermocellum rapidly deconstructs cellulose and ferments resulting hydrolysis products into ethanol and other products, and is thus a promising platform organism for the development of cellulosic biofuel production via consolidated bioprocessing. While recent metabolic engineering strategies have targeted eliminating canonical fermentation products (acetate, lactate, formate, and H 2 ), C. thermocellum also secretes amino acids, which has limited ethanol yields in engineered strains to approximately 70% of the theoretical maximum. To investigate approaches to decrease amino acid secretion, we attempted to reduce ammonium assimilation by deleting the Type I glutamine synthetase (glnA) in an essentially wild type strain of C. thermocellum. Deletion of glnA reduced levels of secreted valine and total amino acids by 53% and 44% respectively, and increased ethanol yields by 53%. RNA-seq analysis revealed that genes encoding the RNF-complex were more highly expressed in ΔglnA and may have a role in improving NADH-availability for ethanol production. While a significant up-regulation of genes involved in nitrogen assimilation and urea uptake suggested that deletion of glnA induces a nitrogen starvation response, metabolomic analysis showed an increase in intracellular glutamine levels indicative of nitrogen-rich conditions. We propose that deletion of glnA causes deregulation of nitrogen metabolism, leading to overexpression of nitrogen metabolism genes and, in turn, elevated glutamine levels. Here we demonstrate that perturbation of nitrogen assimilation is a promising strategy to redirect flux from the production of nitrogenous compounds toward biofuels in C. thermocellum. Copyright © 2017. Published by Elsevier Inc.

Creatine, Glutamine plus Glutamate, and Macromolecules Are Decreased in the Central White Matter of Premature Neonates around Term.

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Meriam Koob

Full Text Available Preterm birth represents a high risk of neurodevelopmental disabilities when associated with white-matter damage. Recent studies have reported cognitive deficits in children born preterm without brain injury on MRI at term-equivalent age. Understanding the microstructural and metabolic underpinnings of these deficits is essential for their early detection. Here, we used diffusion-weighted imaging and single-voxel 1H magnetic resonance spectroscopy (MRS to compare brain maturation at term-equivalent age in premature neonates with no evidence of white matter injury on conventional MRI except diffuse excessive high-signal intensity, and normal term neonates. Thirty-two infants, 16 term neonates (mean post-conceptional age at scan: 39.8±1 weeks and 16 premature neonates (mean gestational age at birth: 29.1±2 weeks, mean post-conceptional age at scan: 39.2±1 weeks were investigated. The MRI/MRS protocol performed at 1.5T involved diffusion-weighted MRI and localized 1H-MRS with the Point RESolved Spectroscopy (PRESS sequence. Preterm neonates showed significantly higher ADC values in the temporal white matter (P<0.05, the occipital white matter (P<0.005 and the thalamus (P<0.05. The proton spectrum of the centrum semiovale was characterized by significantly lower taurine/H2O and macromolecules/H2O ratios (P<0.05 at a TE of 30 ms, and reduced (creatine+phosphocreatine/H2O and (glutamine+glutamate/H2O ratios (P<0.05 at a TE of 135 ms in the preterm neonates than in full-term neonates. Our findings indicate that premature neonates with normal conventional MRI present a delay in brain maturation affecting the white matter and the thalamus. Their brain metabolic profile is characterized by lower levels of creatine, glutamine plus glutamate, and macromolecules in the centrum semiovale, a finding suggesting altered energy metabolism and protein synthesis.

Proximal tubule-specific glutamine synthetase deletion alters basal and acidosis-stimulated ammonia metabolism

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Lee, Hyun-Wook; Osis, Gunars; Handlogten, Mary E.; Lamers, Wouter H.; Chaudhry, Farrukh A.; Verlander, Jill W.

2016-01-01

Glutamine synthetase (GS) catalyzes the recycling of NH4+ with glutamate to form glutamine. GS is highly expressed in the renal proximal tubule (PT), suggesting ammonia recycling via GS could decrease net ammoniagenesis and thereby limit ammonia available for net acid excretion. The purpose of the present study was to determine the role of PT GS in ammonia metabolism under basal conditions and during metabolic acidosis. We generated mice with PT-specific GS deletion (PT-GS-KO) using Cre-loxP techniques. Under basal conditions, PT-GS-KO increased urinary ammonia excretion significantly. Increased ammonia excretion occurred despite decreased expression of key proteins involved in renal ammonia generation. After the induction of metabolic acidosis, the ability to increase ammonia excretion was impaired significantly by PT-GS-KO. The blunted increase in ammonia excretion occurred despite greater expression of multiple components of ammonia generation, including SN1 (Slc38a3), phosphate-dependent glutaminase, phosphoenolpyruvate carboxykinase, and Na+-coupled electrogenic bicarbonate cotransporter. We conclude that 1) GS-mediated ammonia recycling in the PT contributes to both basal and acidosis-stimulated ammonia metabolism and 2) adaptive changes in other proteins involved in ammonia metabolism occur in response to PT-GS-KO and cause an underestimation of the role of PT GS expression. PMID:27009341

Glutamine/glutamate (Glx) concentration in prefrontal cortex predicts reversal learning performance in the marmoset.

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Lacreuse, Agnès; Moore, Constance M; LaClair, Matthew; Payne, Laurellee; King, Jean A

2018-07-02

This study used Magnetic Resonance Spectroscopy (MRS) to identify potential neurometabolitic markers of cognitive performance in male (n = 7) and female (n = 8) middle-aged (∼5 years old) common marmosets (Callithrix jacchus). Anesthetized marmosets were scanned with a 4.7 T/40 cm horizontal magnet equipped with 450 mT/m magnetic field gradients and a 20 G/cm magnetic field gradient insert, within 3 months of completing the CANTAB serial Reversal Learning task. Neurometabolite concentrations of N-Acetyl Asparate, Myo-Inositol, Choline, Phosphocreatine + creatine, Glutamate and Glutamine were acquired from a 3 mm 3 voxel positioned in the Prefrontal Cortex (PFC). Males acquired the reversals (but not simple discriminations) faster than the females. Higher PFC Glx (glutamate + glutamine) concentration was associated with faster acquisition of the reversals. Interestingly, the correlation between cognitive performance and Glx was significant in males, but not in females. These results suggest that MRS is a useful tool to identify biochemical markers of cognitive performance in the healthy nonhuman primate brain and that biological sex modulates the relationship between neurochemical composition and cognition. Copyright © 2018 Elsevier B.V. All rights reserved.

Intravenous glutamine does not modify leucocyte count but shortens duration of mucositis after bone marrow transplant

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María Belén Andrade Hernández

2018-04-01

Full Text Available Rationale: Intravenous administration of Glutamine dipeptides (Gln has been proposed as treatment of oral mucositis following a bone marrow transplant (BMT. Objective: To establish the effects of intravenous Gln supplementation upon the severity of oral mucositis after BMT. Study design: Retrospective, analytical. Study serie: Records from 25 patients (Males: 56.0%; BMT cause: Leukemia: 64.0% who developed oral mucositis (Grades III – IV: 48.0% after BMT (Autologous: 44.0% at the "Juan Tanca Marengo" Hospital (Guayaquil, Ecuador between 2009 – 2017. Glutamine source: Dipeptiven©®: 13 grams of Gln suspended in 100 milliliters of a 20% solution of the alanine-glutamine dipeptide (Fresenius-Kabi©®, Germany. Materials and Methods: Gln-treated patients received 3(4.0% of the treatment leg, 5 (20.0%; 6 (12.0%; 7 (48.0%; or 10 (16.0% doses of the dipeptide until resolution of the symptoms. Impact of Gln was estimated from changes observed in the severity and duration of mucositis, white blood cell counts, and body weight regarding 25 non-Gln treated patients (Males: 68.0%; Leukemias: 32.0%; Autologous graft: 68.0%; Grade III – IV mucositis: 48.0%. Results: Intravenously-administered Gln shortened duration of oral mucositis: Gln-Treated: 12.5 ± 5.1 days vs. Non-Gln Treated: 21.3 ± 17.8 days (p < 0.05. Also, intravenous Gln marginally ameliorated loss of body weight: Gln-Treated -4.5 ± 5.5% vs. Non-Gln Treated: -7.5 ± 5.7% (p = 0.07. Conclusions: Intravenous Gln administration shortens duration of oral mucositis following BMT. Gln effect might be translated to a lesser weight loss in patients with oral mucositis.

Oral feeding with L-Glutamine and Nucleotides: impact on some GALT (gut associated lymphoid tissue parameters and cell proliferation/death rates in weaning piglets

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V. Bontempo

2011-03-01

Full Text Available Dietary supplementation with glutamine and nucleotides may be useful during piglets weaning, when a rough passage from milk suckling to a solid feed may cause a strong reduction of the length of intestinal villi height and the depth of the crypts, and consequently of the intestinal digestive and absorptive capacities (Van Beers-Schreurs et al., 1998. Glutamine stimulates cell proliferation and activates protein kinases, suggesting that it could control the regularly alternating cellular apoptosis/proliferation sequence (Rhoads et al., 2000...

Activity of the lactate-alanine shuttle is independent of glutamate-glutamine cycle activity in cerebellar neuronal-astrocytic cultures

DEFF Research Database (Denmark)

Bak, Lasse K; Sickmann, Helle M; Schousboe, Arne

2004-01-01

The glutamate-glutamine cycle describes the neuronal release of glutamate into the synaptic cleft, astrocytic uptake, and conversion into glutamine, followed by release for use as a neuronal glutamate precursor. This only explains the fate of the carbon atoms, however, and not that of the ammonia....... Recently, a role for alanine has been proposed in transfer of ammonia between glutamatergic neurons and astrocytes, denoted the lactate-alanine shuttle (Waagepetersen et al. [ 2000] J. Neurochem. 75:471-479). The role of alanine in this context has been studied further using cerebellar neuronal cultures...... and corresponding neuronal-astrocytic cocultures. A superfusion paradigm was used to induce repetitively vesicular glutamate release by N-methyl-D-aspartate (NMDA) in the neurons, allowing the relative activity dependency of the lactate-alanine shuttle to be assessed. [(15)N]Alanine (0.2 mM), [2-(15)N]/[5-(15)N...

Vaccatides: Antifungal Glutamine-Rich Hevein-Like Peptides from Vaccaria hispanica

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Ka H. Wong

2017-06-01

Full Text Available Hevein and hevein-like peptides are disulfide-constrained chitin-binding cysteine-rich peptides. They are divided into three subfamilies, 6C-, 8C-, and 10C-hevein-like peptides, based on the number of cysteine residues. In addition, hevein-like peptides can exist in two forms, short and long. The long C-terminal form found in hevein and 10C-hevein-like peptides contain a C-terminal protein cargo. In contrast, the short form without a protein cargo is found in all three subfamilies. Here, we report the discovery and characterization of two novel glutamine-rich and protein cargo-free 8C-hevein-like peptides, vaccatides vH1 and vH2, from Vaccaria hispanica of the Caryophyllaceae family. Proteomic analyses showed that the vaccatides are 40–41 amino acids in length and contain a chitin-binding domain. NMR determination revealed that vaccatide vH2 displays a highly compact structure with a N-terminal cystine knot and an addition C-terminal disulfide bond. Stability studies showed that this compact structure renders vaccatide vH2 resistant to thermal, chemical and proteolytic degradation. The chitin-binding vH2 was shown to inhibit the mycelium growth of four phyto-pathogenic fungal strains with IC50 values in the micromolar range. Our findings show that vaccatides represent a new family of 8C-hevein-like peptides, which are protein cargo-free and glutamine-rich, characteristics that differentiate them from the prototypic hevein and the 10C-hevein-like peptides. In summary, this study enriches the existing library of hevein-like peptides and provides insight into their molecular diversity in sequence, structure and biosynthesis. Additionally, their highly disulfide-constrained structure could be used as a scaffold for developing metabolically and orally active peptidyl therapeutics.

Medicago truncatula contains a second gene encoding a plastid located glutamine synthetase exclusively expressed in developing seeds

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Seabra Ana R

2010-08-01

Full Text Available Abstract Background Nitrogen is a crucial nutrient that is both essential and rate limiting for plant growth and seed production. Glutamine synthetase (GS, occupies a central position in nitrogen assimilation and recycling, justifying the extensive number of studies that have been dedicated to this enzyme from several plant sources. All plants species studied to date have been reported as containing a single, nuclear gene encoding a plastid located GS isoenzyme per haploid genome. This study reports the existence of a second nuclear gene encoding a plastid located GS in Medicago truncatula. Results This study characterizes a new, second gene encoding a plastid located glutamine synthetase (GS2 in M. truncatula. The gene encodes a functional GS isoenzyme with unique kinetic properties, which is exclusively expressed in developing seeds. Based on molecular data and the assumption of a molecular clock, it is estimated that the gene arose from a duplication event that occurred about 10 My ago, after legume speciation and that duplicated sequences are also present in closely related species of the Vicioide subclade. Expression analysis by RT-PCR and western blot indicate that the gene is exclusively expressed in developing seeds and its expression is related to seed filling, suggesting a specific function of the enzyme associated to legume seed metabolism. Interestingly, the gene was found to be subjected to alternative splicing over the first intron, leading to the formation of two transcripts with similar open reading frames but varying 5' UTR lengths, due to retention of the first intron. To our knowledge, this is the first report of alternative splicing on a plant GS gene. Conclusions This study shows that Medicago truncatula contains an additional GS gene encoding a plastid located isoenzyme, which is functional and exclusively expressed during seed development. Legumes produce protein-rich seeds requiring high amounts of nitrogen, we postulate

Glutamine Supplementation in Sick Children: Is It Beneficial?

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Elise Mok

2011-01-01

Full Text Available The purpose of this review is to provide a critical appraisal of the literature on Glutamine (Gln supplementation in various conditions or illnesses that affect children, from neonates to adolescents. First, a general overview of the proposed mechanisms for the beneficial effects of Gln is provided, and subsequently clinical studies are discussed. Despite safety, studies are conflicting, partly due to different effects of enteral and parenteral Gln supplementation. Further insufficient evidence is available on the benefits of Gln supplementation in pediatric patients. This includes premature infants, infants with gastrointestinal disease, children with Crohn's disease, short bowel syndrome, malnutrition/diarrhea, cancer, severe burns/trauma, Duchenne muscular dystrophy, sickle cell anemia, cystic fibrosis, and type 1 diabetes. Moreover, methodological issues have been noted in some studies. Further mechanistic data is needed along with large randomized controlled trials in select populations of sick children, who may eventually benefit from supplemental Gln.

Comprehensive characterization of glutamine synthetase-mediated selection for the establishment of recombinant CHO cells producing monoclonal antibodies.

Science.gov (United States)

Noh, Soo Min; Shin, Seunghyeon; Lee, Gyun Min

2018-03-29

To characterize a glutamine synthetase (GS)-based selection system, monoclonal antibody (mAb) producing recombinant CHO cell clones were generated by a single round of selection at various methionine sulfoximine (MSX) concentrations (0, 25, and 50 μM) using two different host cell lines (CHO-K1 and GS-knockout CHO). Regardless of the host cell lines used, the clones selected at 50 μM MSX had the lowest average specific growth rate and the highest average specific production rates of toxic metabolic wastes, lactate and ammonia. Unlike CHO-K1, high producing clones could be generated in the absence of MSX using GS-knockout CHO with an improved selection stringency. Regardless of the host cell lines used, the clones selected at various MSX concentrations showed no significant difference in the GS, heavy chain, and light chain gene copies (P > 0.05). Furthermore, there was no correlation between the specific mAb productivity and these three gene copies (R 2  ≤ 0.012). Taken together, GS-mediated gene amplification does not occur in a single round of selection at a MSX concentration up to 50 μM. The use of the GS-knockout CHO host cell line facilitates the rapid generation of high producing clones with reduced production of lactate and ammonia in the absence of MSX.

Survey of Synergistic Effect of L-carnitine with Glutamine on Body Composition and Dietary Intake in Soccer Players: A Double-blind, Randomized Clinical Trial

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Mohammad Hozoori

2016-10-01

Full Text Available Background: The present study was conducted to investigate the possible effects of L-carnitine and glutamine and their synergistic effects on male soccer athletes. Methods: 28 male soccer players (21.1 ± 0.7 y were enrolled in a randomized pre and post intervention, double-blind design. Before the intervention, their performances were assessed by Bruce protocol, and their body composition was measured with the body composition analyzer. Then, athletes were randomly allocated into four groups: 2 g L-glutamine, 2 g L-carnitine, 2 g L-carnitine + 2 g L-glutamine and placebo. Supplements were prescribed for 21 days and after three weeks, athletes' performances and body composition were re-evaluated. Results: The results showed that body weight, body fat percentage, lean muscle mass, and dietary intake made no significant changes in different groups of athletes. In between groups comparison, results did not significantly change in any performance indices. However, in L-carnitine supplement group, the results of pre and post intervention showed that the running distance and maximal oxygen uptake (VO2max increased significantly while the subjective sense of fatigue decreased significantly. Conclusions: Based on our findings, a three-week prescription of separateor combined glutamine and L-carnitine, had no effects on body composition or dietary intake in soccer players. But, the athletes' energy intake was more than the one reported in other studies. Although further studies are required to assess these effects on athletic performance.

Effects of Supplementation with BCAA and L-glutamine on Blood Fatigue Factors and Cytokines in Juvenile Athletes Submitted to Maximal Intensity Rowing Performance.

Science.gov (United States)

Koo, Ga Hee; Woo, Jinhee; Kang, Sungwhun; Shin, Ki Ok

2014-08-01

[Purpose] This study was conducted to understand the impacts of BCAA (branched-chain amino acid) and glutamine supplementation on the degree of blood fatigue factor stimulation and cytokines along with performance of exercise at the maximal intensity. [Subjects] Five male juvenile elite rowing athletes participated in this study as the subjects; they took 3 tests and received placebo supplementation (PS), BCAA supplementation (BS), and glutamine supplementation (GS). [Methods] The exercise applied in the tests was 2,000 m of rowing at the maximal intensity using an indoor rowing machine, and blood samples were collected 3 times, while resting, at the end of exercise, and after 30 min of recovery, to analyze the blood fatigue factors (lactate, phosphorous, ammonia, creatine kinase (CK)) and blood cytokines (IL (interleukin)-6, 8, 15). [Results] The results of the analysis showed that the levels of blood phosphorous in the BS and GS groups at the recovery stage were decreased significantly compared with at the end of exercise, and the level of CK appeared lower in the GS group alone at recovery stage than at the end of exercise. The level of blood IL-15 in the PS and BS groups appeared higher at the end of exercise compared with the resting stage. [Conclusion] It seemed that glutamine supplementation had a positive effect on the decrease in fatigue factor stimulation at the recovery stage after maximal intensity exercise compared with supplementation with the placebo or BCAA. Besides, pre-exercise glutamine supplementation seemed to help enhance immune function and the defensive inflammatory reaction.

Energy metabolism and glutamate-glutamine cycle in the brain: a stoichiometric modeling perspective.

Science.gov (United States)

Massucci, Francesco A; DiNuzzo, Mauro; Giove, Federico; Maraviglia, Bruno; Castillo, Isaac Perez; Marinari, Enzo; De Martino, Andrea

2013-10-10

The energetics of cerebral activity critically relies on the functional and metabolic interactions between neurons and astrocytes. Important open questions include the relation between neuronal versus astrocytic energy demand, glucose uptake and intercellular lactate transfer, as well as their dependence on the level of activity. We have developed a large-scale, constraint-based network model of the metabolic partnership between astrocytes and glutamatergic neurons that allows for a quantitative appraisal of the extent to which stoichiometry alone drives the energetics of the system. We find that the velocity of the glutamate-glutamine cycle (Vcyc) explains part of the uncoupling between glucose and oxygen utilization at increasing Vcyc levels. Thus, we are able to characterize different activation states in terms of the tissue oxygen-glucose index (OGI). Calculations show that glucose is taken up and metabolized according to cellular energy requirements, and that partitioning of the sugar between different cell types is not significantly affected by Vcyc. Furthermore, both the direction and magnitude of the lactate shuttle between neurons and astrocytes turn out to depend on the relative cell glucose uptake while being roughly independent of Vcyc. These findings suggest that, in absence of ad hoc activity-related constraints on neuronal and astrocytic metabolism, the glutamate-glutamine cycle does not control the relative energy demand of neurons and astrocytes, and hence their glucose uptake and lactate exchange.

Glutamine and ornithine alpha-ketoglutarate supplementation on malate dehydrogenases expression in hepatectomized rats.

Science.gov (United States)

Guimarães Filho, Artur; Cunha, Rodrigo Maranguape Silva da; Vasconcelos, Paulo Roberto Leitão de; Guimarães, Sergio Botelho

2014-06-01

To evaluate the relative gene expression (RGE) of cytosolic (MDH1) and mitochondrial (MDH2) malate dehydrogenases enzymes in partially hepatectomized rats after glutamine (GLN) or ornithine alpha-ketoglutarate (OKG) suplementation. One-hundred and eight male Wistar rats were randomly distributed into six groups (n=18): CCaL, GLNL and OKGL and fed calcium caseinate (CCa), GLN and OKG, 0.5 g/Kg by gavage, 30 minutes before laparotomy. CCaH, GLNH and OKGH groups were likewise fed 30 minutes before 70% partial hepatectomy. Blood and liver samples were collected three, seven and 14 days after laparotomy/hepatectomy for quantification of MDH1/MDH2 enzymes using the real-time polymerase chain reaction (PCR) methodology. Relative enzymes expression was calculated by the 2-(ΔΔC)T method using the threshold cycle (CT) value for normalization. MDH1/MDH2 RGE was not different in hepatectomized rats treated with OKG compared to rats treated with CCa. However, MDH1/MDH2 RGE was greater on days 3 (321:1/26.48:1) and 7 (2.12:1/2.48:1) while MDH2 RGE was greater on day 14 (7.79:1) in hepatectomized rats treated with GLN compared to control animals. Glutamine has beneficial effects in liver regeneration in rats by promoting an up-regulation of the MDH1 and MDH2 relative gene expression.

Energy metabolism and glutamate-glutamine cycle in the brain: a stoichiometric modeling perspective

Science.gov (United States)

2013-01-01

Background The energetics of cerebral activity critically relies on the functional and metabolic interactions between neurons and astrocytes. Important open questions include the relation between neuronal versus astrocytic energy demand, glucose uptake and intercellular lactate transfer, as well as their dependence on the level of activity. Results We have developed a large-scale, constraint-based network model of the metabolic partnership between astrocytes and glutamatergic neurons that allows for a quantitative appraisal of the extent to which stoichiometry alone drives the energetics of the system. We find that the velocity of the glutamate-glutamine cycle (Vcyc) explains part of the uncoupling between glucose and oxygen utilization at increasing Vcyc levels. Thus, we are able to characterize different activation states in terms of the tissue oxygen-glucose index (OGI). Calculations show that glucose is taken up and metabolized according to cellular energy requirements, and that partitioning of the sugar between different cell types is not significantly affected by Vcyc. Furthermore, both the direction and magnitude of the lactate shuttle between neurons and astrocytes turn out to depend on the relative cell glucose uptake while being roughly independent of Vcyc. Conclusions These findings suggest that, in absence of ad hoc activity-related constraints on neuronal and astrocytic metabolism, the glutamate-glutamine cycle does not control the relative energy demand of neurons and astrocytes, and hence their glucose uptake and lactate exchange. PMID:24112710

Glutamine and ornithine alpha-ketoglutarate supplementation on malate dehydrogenases expression in hepatectomized rats

OpenAIRE

Guimarães Filho, Artur; Cunha, Rodrigo Maranguape Silva da; Vasconcelos, Paulo Roberto Leitão de; Guimarães, Sergio Botelho

2014-01-01

PURPOSE: To evaluate the relative gene expression (RGE) of cytosolic (MDH1) and mitochondrial (MDH2) malate dehydrogenases enzymes in partially hepatectomized rats after glutamine (GLN) or ornithine alpha-ketoglutarate (OKG) suplementation. METHODS: One-hundred and eight male Wistar rats were randomly distributed into six groups (n=18): CCaL, GLNL and OKGL and fed calcium caseinate (CCa), GLN and OKG, 0.5g/Kg by gavage, 30 minutes before laparotomy. CCaH, GLNH and OKGH groups were likewise fe...

The impact of use of Glutamine on patients with head and neck tumors in radiotherapy and chemotherapy treatment; O Impacto do uso de Glutamina em pacientes com tumores de cabeca e pescoco em tratamento radioterapico e quimioterapico

Energy Technology Data Exchange (ETDEWEB)

Boligon, Caroline Schardong, E-mail: caronut@bol.com.b [Hospital de Caridade de Ijui, RS (Brazil); Huth, Adriane, E-mail: adriane.huth@unijui.edu.b [UNIJUI, RS (Brazil). Dept. Ciencias da Saude

2011-07-01

Introduction: patients with head and neck neoplasia usually show malnutrition or a nutritional risk, because of common symptoms like: dysphagia, odynophagia and xerostomia. Objective: this study aimed to verify the impact of using amino glutamine in patients with head and neck neoplasia and under radiotherapy and chemotherapy treatment concomitantly. Methods: the research was quantitative, cross-sectional, descriptive and exploratory. The data was collected from nutritional evaluation, and patients chart consultation. The patients were divided in a control group (without use of glutamine) and a test group (with use of glutamine). 16 patients, 13 of which were men and three were women, participated in the research. Results: The control group presented mucositis grades I to IV while patients who used the amino glutamine showed mucositis grades I to II only. It could be observed that the Nutritional Risk Index decreased, which represents higher nutritional risk in patients from the control group only. In patients who used glutamine, this decrease was not significant. Conclusion: these results suggest that the use of glutamine in patients with head and neck tumors and under antineoplastic therapy helps to maintain their nutritional stage and to prevent mucositis throughout their treatment, mainly grades III and IV, which prevents adequate and regular eating and nourishment. (author)

Coeliac disease autoantibodies mediate significant inhibition of tissue transglutaminase.

LENUS (Irish Health Repository)

Byrne, Greg

2012-02-01

The detection of antibodies directed against tissue transglutaminase (tTG) in serum is a sensitive and specific test for suspected coeliac disease. tTG is a ubiquitous, multifunctional enzyme that has been implicated in many important physiological processes as well as the site-specific deamidation of glutamine residues in gluten-derived peptides. This modification of gluten peptides facilitates their binding to HLA-DQ2, which results in amplification of the T-cell response to gluten. The purpose of this study was to investigate the possibility that patient IgA autoantibodies directed against tTG interfere with the crosslinking activity of the enzyme. IgA autoantibodies against tTG were isolated\\/depleted from patient serum and tested for their capacity to interfere with tTG activity in vitro using a sensitive fluorescence-based activity assay. We have demonstrated that autoantibodies cause significant inhibition of tTG-mediated crosslinking at equimolar and 2:1 ratios of antibody to enzyme.

Inactivation of the glutamine/amino acid transporter ASCT2 by 1,2,3-dithiazoles: proteoliposomes as a tool to gain insights in the molecular mechanism of action and of antitumor activity

International Nuclear Information System (INIS)

Oppedisano, Francesca; Catto, Marco; Koutentis, Panayiotis A.; Nicolotti, Orazio; Pochini, Lorena; Koyioni, Maria; Introcaso, Antonellina; Michaelidou, Sophia S.; Carotti, Angelo; Indiveri, Cesare

2012-01-01

The ASCT2 transport system catalyses a sodium-dependent antiport of glutamine and other neutral amino acids which is involved in amino acid metabolism. A library of 1,2,3-dithiazoles was designed, synthesized and evaluated as inhibitors of the glutamine/amino acid ASCT2 transporter in the model system of proteoliposomes reconstituted with the rat liver transporter. Fifteen of the tested compounds at concentration of 20 μM or below, inhibited more than 50% the glutamine/glutamine antiport catalysed by the reconstituted transporter. These good inhibitors bear a phenyl ring with electron withdrawing substituents. The inhibition was reversed by 1,4-dithioerythritol indicating that the effect was likely owed to the formation of mixed sulfides with the protein's Cys residue(s). A dose–response analysis of the most active compounds gave IC 50 values in the range of 3–30 μM. Kinetic inhibition studies indicated a non-competitive inhibition, presumably because of a potential covalent interaction of the dithiazoles with cysteine thiol groups that are not located at the substrate binding site. Indeed, computational studies using a homology structural model of ASCT2 transporter, suggested as possible binding targets, Cys-207 or Cys-210, that belong to the CXXC motif of the protein. -- Highlights: ► Non‐competitive inhibition of ASCT2 by 1,2,3-dithiazoles was studied in proteoliposomes. ► Different 1,2,3-dithiazoles were synthesized and evaluated as transporter inhibitors. ► Many compounds potently inhibited the glutamine/glutamine antiport catalyzed by ASCT2. ► The inhibition was reversed by DTE indicating reaction with protein Cys. ► The most active compounds gave IC 50 in the range of 3–30 μM.

Inactivation of the glutamine/amino acid transporter ASCT2 by 1,2,3-dithiazoles: proteoliposomes as a tool to gain insights in the molecular mechanism of action and of antitumor activity

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Oppedisano, Francesca [Dipartimento di Biologia Cellulare Università della Calabria, via P. Bucci 4 c, 87036 Arcavacata di Rende (CS) (Italy); Catto, Marco [Dipartimento Farmaco-Chimico, Università degli Studi “Aldo Moro,”, via Orabona 4, 70125 Bari (Italy); Koutentis, Panayiotis A. [Department of Chemistry, University of Cyprus, P.O. Box 20537, 1678 Nicosia (Cyprus); Nicolotti, Orazio [Dipartimento Farmaco-Chimico, Università degli Studi “Aldo Moro,”, via Orabona 4, 70125 Bari (Italy); Pochini, Lorena [Dipartimento di Biologia Cellulare Università della Calabria, via P. Bucci 4 c, 87036 Arcavacata di Rende (CS) (Italy); Koyioni, Maria [Department of Chemistry, University of Cyprus, P.O. Box 20537, 1678 Nicosia (Cyprus); Introcaso, Antonellina [Dipartimento Farmaco-Chimico, Università degli Studi “Aldo Moro,”, via Orabona 4, 70125 Bari (Italy); Michaelidou, Sophia S. [Department of Chemistry, University of Cyprus, P.O. Box 20537, 1678 Nicosia (Cyprus); Carotti, Angelo, E-mail: carotti@farmchim.uniba.it [Dipartimento Farmaco-Chimico, Università degli Studi “Aldo Moro,”, via Orabona 4, 70125 Bari (Italy); Indiveri, Cesare, E-mail: indiveri@unical.it [Dipartimento di Biologia Cellulare Università della Calabria, via P. Bucci 4 c, 87036 Arcavacata di Rende (CS) (Italy)

2012-11-15

The ASCT2 transport system catalyses a sodium-dependent antiport of glutamine and other neutral amino acids which is involved in amino acid metabolism. A library of 1,2,3-dithiazoles was designed, synthesized and evaluated as inhibitors of the glutamine/amino acid ASCT2 transporter in the model system of proteoliposomes reconstituted with the rat liver transporter. Fifteen of the tested compounds at concentration of 20 μM or below, inhibited more than 50% the glutamine/glutamine antiport catalysed by the reconstituted transporter. These good inhibitors bear a phenyl ring with electron withdrawing substituents. The inhibition was reversed by 1,4-dithioerythritol indicating that the effect was likely owed to the formation of mixed sulfides with the protein's Cys residue(s). A dose–response analysis of the most active compounds gave IC{sub 50} values in the range of 3–30 μM. Kinetic inhibition studies indicated a non-competitive inhibition, presumably because of a potential covalent interaction of the dithiazoles with cysteine thiol groups that are not located at the substrate binding site. Indeed, computational studies using a homology structural model of ASCT2 transporter, suggested as possible binding targets, Cys-207 or Cys-210, that belong to the CXXC motif of the protein. -- Highlights: ► Non‐competitive inhibition of ASCT2 by 1,2,3-dithiazoles was studied in proteoliposomes. ► Different 1,2,3-dithiazoles were synthesized and evaluated as transporter inhibitors. ► Many compounds potently inhibited the glutamine/glutamine antiport catalyzed by ASCT2. ► The inhibition was reversed by DTE indicating reaction with protein Cys. ► The most active compounds gave IC{sub 50} in the range of 3–30 μM.

Chronic probiotic supplementation with or without glutamine does not influence the eHsp72 response to a multi-day ultra-endurance exercise event.

Science.gov (United States)

Marshall, Hannah; Chrismas, Bryna Catherine Rose; Suckling, Craig Anthony; Roberts, Justin D; Foster, Josh; Taylor, Lee

2017-08-01

Probiotic and glutamine supplementation increases tissue Hsp72, but their influence on extracellular Hsp72 (eHsp72) has not been investigated. The aim of this study was to investigate the effect of chronic probiotic supplementation, with or without glutamine, on eHsp72 concentration before and after an ultramarathon. Thirty-two participants were split into 3 independent groups, where they ingested probiotic capsules (PRO; n = 11), probiotic + glutamine powder (PGLn; n = 10), or no supplementation (CON; n = 11), over a 12-week period prior to commencement of the Marathon des Sables (MDS). eHsp72 concentration in the plasma was measured at baseline, 7 days pre-race, 6-8 h post-race, and 7 days post-race. The MDS increased eHsp72 concentrations by 124% (F [1,3] = 22.716, p 0.05). In conclusion, the MDS caused a substantial increase in eHsp72 concentration, indicating high levels of systemic stress. However, chronic PRO or PGLn supplementation did not affect eHsp72 compared with control pre- or post-MDS. Given the role of eHsp72 in immune activation, the commercially available supplements used in this study are unlikely to influence this cascade.

Nitrogen Starvation and TorC1 Inhibition Differentially Affect Nuclear Localization of the Gln3 and Gat1 Transcription Factors Through the Rare Glutamine tRNACUG in Saccharomyces cerevisiae

Science.gov (United States)

Tate, Jennifer J.; Rai, Rajendra; Cooper, Terrance G.

2015-01-01

A leucine, leucyl-tRNA synthetase–dependent pathway activates TorC1 kinase and its downstream stimulation of protein synthesis, a major nitrogen consumer. We previously demonstrated, however, that control of Gln3, a transcription activator of catabolic genes whose products generate the nitrogenous precursors for protein synthesis, is not subject to leucine-dependent TorC1 activation. This led us to conclude that excess nitrogen-dependent down-regulation of Gln3 occurs via a second mechanism that is independent of leucine-dependent TorC1 activation. A major site of Gln3 and Gat1 (another GATA-binding transcription activator) control occurs at their access to the nucleus. In excess nitrogen, Gln3 and Gat1 are sequestered in the cytoplasm in a Ure2-dependent manner. They become nuclear and activate transcription when nitrogen becomes limiting. Long-term nitrogen starvation and treatment of cells with the glutamine synthetase inhibitor methionine sulfoximine (Msx) also elicit nuclear Gln3 localization. The sensitivity of Gln3 localization to glutamine and inhibition of glutamine synthesis prompted us to investigate the effects of a glutamine tRNA mutation (sup70-65) on nitrogen-responsive control of Gln3 and Gat1. We found that nuclear Gln3 localization elicited by short- and long-term nitrogen starvation; growth in a poor, derepressive medium; Msx or rapamycin treatment; or ure2Δ mutation is abolished in a sup70-65 mutant. However, nuclear Gat1 localization, which also exhibits a glutamine tRNACUG requirement for its response to short-term nitrogen starvation or growth in proline medium or a ure2Δ mutation, does not require tRNACUG for its response to rapamycin. Also, in contrast with Gln3, Gat1 localization does not respond to long-term nitrogen starvation. These observations demonstrate the existence of a specific nitrogen-responsive component participating in the control of Gln3 and Gat1 localization and their downstream production of nitrogenous precursors

Chemical Etching, AFM, Laser Damage Threshold, and Nonlinear Optical Studies of Potential Nonlinear Optical Crystal: Bis (L-Glutamine Potassium Nitrate

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Redrothu Hanumantharao

2013-01-01

Full Text Available A novel semiorganic nonlinear optical crystal bis (L-glutamine potassium nitrate (BGPN grown by slow evaporation technique at ambient temperature. The grown crystal surface has been analyzed by chemical etching and atomic force microscopy (AFM studies. Amplitude parameters like area roughness, roughness average, valley height, valley depth, peak height, and peak valley height were measured successfully from AFM studies. Etching studies were carried out by various solvents like water, methanol and ethanol. The etching study indicates the occurrence of different types of etch pit patterns like striations and steplike pattern. The laser damage threshold energy has been measured by irradiating laser beam using a Q-switched Nd: YAG laser (1064 nm. Second harmonic generation (SHG studies have been performed by famous Kurtz powder technique with reference to standard potassium dihydrogen phosphate single crystals (KDP. It is found from this technique that SHG efficiency of BGPN is in comparison to that of standard KDP crystals.

Brain alanine formation as an ammonia-scavenging pathway during hyperammonemia: effects of glutamine synthetase inhibition in rats and astrocyte–neuron co-cultures

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Dadsetan, Sherry; Kukolj, Eva; Bak, Lasse K; Sørensen, Michael; Ott, Peter; Vilstrup, Hendrik; Schousboe, Arne; Keiding, Susanne; Waagepetersen, Helle S

2013-01-01

Hyperammonemia is a major etiological toxic factor in the development of hepatic encephalopathy. Brain ammonia detoxification occurs primarily in astrocytes by glutamine synthetase (GS), and it has been proposed that elevated glutamine levels during hyperammonemia lead to astrocyte swelling and cerebral edema. However, ammonia may also be detoxified by the concerted action of glutamate dehydrogenase (GDH) and alanine aminotransferase (ALAT) leading to trapping of ammonia in alanine, which in vivo likely leaves the brain. Our aim was to investigate whether the GS inhibitor methionine sulfoximine (MSO) enhances incorporation of 15NH4+ in alanine during acute hyperammonemia. We observed a fourfold increased amount of 15NH4 incorporation in brain alanine in rats treated with MSO. Furthermore, co-cultures of neurons and astrocytes exposed to 15NH4Cl in the absence or presence of MSO demonstrated a dose-dependent incorporation of 15NH4 into alanine together with increased 15N incorporation in glutamate. These findings provide evidence that ammonia is detoxified by the concerted action of GDH and ALAT both in vivo and in vitro, a mechanism that is accelerated in the presence of MSO thereby reducing the glutamine level in brain. Thus, GS could be a potential drug target in the treatment of hyperammonemia in patients with hepatic encephalopathy. PMID:23673435

Brain alanine formation as an ammonia-scavenging pathway during hyperammonemia: effects of glutamine synthetase inhibition in rats and astrocyte-neuron co-cultures.

Science.gov (United States)

Dadsetan, Sherry; Kukolj, Eva; Bak, Lasse K; Sørensen, Michael; Ott, Peter; Vilstrup, Hendrik; Schousboe, Arne; Keiding, Susanne; Waagepetersen, Helle S

2013-08-01

Hyperammonemia is a major etiological toxic factor in the development of hepatic encephalopathy. Brain ammonia detoxification occurs primarily in astrocytes by glutamine synthetase (GS), and it has been proposed that elevated glutamine levels during hyperammonemia lead to astrocyte swelling and cerebral edema. However, ammonia may also be detoxified by the concerted action of glutamate dehydrogenase (GDH) and alanine aminotransferase (ALAT) leading to trapping of ammonia in alanine, which in vivo likely leaves the brain. Our aim was to investigate whether the GS inhibitor methionine sulfoximine (MSO) enhances incorporation of (15)NH4(+) in alanine during acute hyperammonemia. We observed a fourfold increased amount of (15)NH4 incorporation in brain alanine in rats treated with MSO. Furthermore, co-cultures of neurons and astrocytes exposed to (15)NH4Cl in the absence or presence of MSO demonstrated a dose-dependent incorporation of (15)NH4 into alanine together with increased (15)N incorporation in glutamate. These findings provide evidence that ammonia is detoxified by the concerted action of GDH and ALAT both in vivo and in vitro, a mechanism that is accelerated in the presence of MSO thereby reducing the glutamine level in brain. Thus, GS could be a potential drug target in the treatment of hyperammonemia in patients with hepatic encephalopathy.

An ultra­high field Magnetic Resonance Spectroscopy study of post exercise brain lactate, glutamate and glutamine change in the human brain.

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Andrea eDennis

2015-12-01

Full Text Available During strenuous exercise there is a progressive increase in lactate uptake and metabolism into the brain as workload and plasma lactate levels increase. Although it is now widely accepted that the brain can metabolise lactate, few studies have directly measured brain lactate following vigorous exercise. Here, we used ultra-high field Magnetic Resonance Spectroscopy of the brain to obtain static measures of brain lactate, as well as brain glutamate and glutamine after vigorous exercise. The aims of our experiment were to (a track the changes in brain lactate following recovery from exercise and, (b to simultaneously measure the signals from brain glutamate and glutamine. The results of our experiment showed that vigorous exercise resulted in a significant increase in brain lactate. Furthermore, both glutamate and glutamine were successfully resolved, and as expected, although contrary to some previous reports, we did not observe any significant change in either amino acid after exercise. We did however observe a negative correlation between glutamate and a measure of fitness. These results support the hypothesis that peripherally-derived lactate is taken up by the brain when available. Our data additionally highlight the potential of ultra-high field magnetic resonance spectroscopy as a non-invasive way of measuring multiple brain metabolite changes with exercise.

Uptake and metabolism of L-[3H]glutamate and L-[3H]glutamine in adult rat cerebellar slices

International Nuclear Information System (INIS)

de Barry, J.; Vincendon, G.; Gombos, G.

1983-01-01

Using very low concentrations (1 mumol range) of L-2-3-[ 3 H]glutamate, ( 3 H-Glu) or L-2-3-[ 3 H]glutamine ( 3 H-Gln), the authors have previously shown by autoradiography that these amino acids were preferentially taken up in the molecular layer of the cerebellar cortex. Furthermore, the accumulation of 3 H-Glu was essentially glial in these conditions. Uptake and metabolism of either ( 3 H-Glu) or ( 3 H-Gln) were studied in adult rat cerebellar slices. Both amino acids were rapidly converted into other metabolic compounds: after seven minutes of incubation in the presence of exogenous 3 H-Glu, 70% of the tissue accumulated radioactivity was found to be in compounds other than glutamate. The main metabolites were Gln (42%), alpha-ketoglutarate (25%) and GABA (1,4%). In the presence of exogenous 3 H-Gln the rate of metabolism was slightly slower (50% after seven minutes of incubation) and the metabolites were also Glu (29%), alpha-ketoglutarate (15%) and GABA (5%). Using depolarizing conditions (56 mM KCl) with either exogenous 3 H-Glu or 3 H-Gln, the radioactivity was preferentially accumulated in glutamate compared to control. From these results we conclude: i) there are two cellular compartments for the neurotransmission-glutamate-glutamine cycle; one is glial, the other neuronal; ii) these two cellular compartments contain both Gln and Glu; iii) transmitter glutamate is always in equilibrium with the so-called ''metabolic'' pool of glutamate; iv) the regulation of the glutamate-glutamine cycle occurs at least at two different levels: the uptake of glutamate and the enzymatic activity of the neuronal glutaminase

Oral Supplementation with Beta-Hydroxy-Beta-Methylbutyrate, Arginine, and Glutamine Improves Lean Body Mass in Healthy Older Adults.

Science.gov (United States)

Ellis, Amy C; Hunter, Gary R; Goss, Amy M; Gower, Barbara A

2018-04-19

Oral intake of beta-hydroxy-beta-methylbutyrate (HMB), arginine, and glutamine may ameliorate muscle loss by stimulating protein synthesis and decreasing protein degradation while simultaneously decreasing inflammation. Previous studies provide evidence for improvement in body composition with dietary supplementation of these ingredients among patients with muscle-wasting diseases. The objectives of this study were to examine the effects of this amino acid mixture on lean body mass, muscle volume, and physical function among healthy older adults. Thirty-one community-dwelling men and women, aged 65-89 years, were randomized to either two oral doses of the amino acid supplement (totaling 3 g HMB, 14 g arginine, 14 g glutamine) or placebo daily for six months. At baseline and month six, lean body mass was measured by air displacement plethysmography, dual-energy X-ray absorptiometry (DXA), and four-compartment model. Muscle volume of quadriceps was quantified by magnetic resonance imaging (MRI), and participants performed a battery of tests to assess physical function. As compared to the placebo group, the treatment group exhibited improvement in a timed stair climb (p =.016) as well as significant increases in lean body mass by all methods of assessment (p lean mass in the supplement group only (p =.035). However, no change was observed in MRI-derived quadriceps volume. Dietary supplementation with HMB, arginine, and glutamine improved total body lean mass among a small sample of healthy older adults. Further research is indicated to elucidate mechanisms of action and to determine whether supplementation may benefit frail elders. Registered under ClinicalTrials.gov identifier no. NCT01057082.

Stereospecific assignment of the asparagine and glutamine sidechain amide protons in proteins from chemical shift analysis

Energy Technology Data Exchange (ETDEWEB)

Harsch, Tobias; Schneider, Philipp; Kieninger, Bärbel; Donaubauer, Harald; Kalbitzer, Hans Robert, E-mail: hans-robert.kalbitzer@biologie.uni-regensburg.de [University of Regensburg, Institute of Biophysics and Physical Biochemistry and Centre of Magnetic Resonance in Chemistry and Biomedicine (Germany)

2017-02-15

Side chain amide protons of asparagine and glutamine residues in random-coil peptides are characterized by large chemical shift differences and can be stereospecifically assigned on the basis of their chemical shift values only. The bimodal chemical shift distributions stored in the biological magnetic resonance data bank (BMRB) do not allow such an assignment. However, an analysis of the BMRB shows, that a substantial part of all stored stereospecific assignments is not correct. We show here that in most cases stereospecific assignment can also be done for folded proteins using an unbiased artificial chemical shift data base (UACSB). For a separation of the chemical shifts of the two amide resonance lines with differences ≥0.40 ppm for asparagine and differences ≥0.42 ppm for glutamine, the downfield shifted resonance lines can be assigned to H{sup δ21} and H{sup ε21}, respectively, at a confidence level >95%. A classifier derived from UASCB can also be used to correct the BMRB data. The program tool AssignmentChecker implemented in AUREMOL calculates the Bayesian probability for a given stereospecific assignment and automatically corrects the assignments for a given list of chemical shifts.

New perspectives on glutamine synthetase in grasses.

Science.gov (United States)

Swarbreck, Stéphanie M; Defoin-Platel, M; Hindle, M; Saqi, M; Habash, Dimah Z

2011-02-01

Members of the glutamine synthetase (GS) gene family have now been characterized in many crop species such as wheat, rice, and maize. Studies have shown that cytosolic GS isoforms are involved in nitrogen remobilization during leaf senescence and emphasized a role in seed production particularly in small grain crop species. Data from the sequencing of genomes for model crops and expressed sequence tag (EST) libraries from non-model species have strengthened the idea that the cytosolic GS genes are organized in three functionally and phylogenetically conserved subfamilies. Using a bioinformatic approach, the considerable publicly available information on high throughput gene expression was mined to search for genes having patterns of expression similar to GS. Interesting new hypotheses have emerged from searching for co-expressed genes across multiple unfiltered experimental data sets in rice. This approach should inform new experimental designs and studies to explore the regulation of the GS gene family further. It is expected that understanding the regulation of GS under varied climatic conditions will emerge as an important new area considering the results from recent studies that have shown nitrogen assimilation to be critical to plant acclimation to high CO(2) concentrations.

Efeito da suplementação com L-alanil-L-glutamina sobre a resposta de hipersensibilidade do tipo tardio em ratos submetidos ao treinamento intenso Effect of L-glutamine and L-alanyl-L-glutamine supplementation on the response to delayed-type hypersensitivity test (DTH in rats submitted to intense training

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Marcelo Macedo Rogero

2002-12-01

Full Text Available O treinamento intenso e o exercício exaustivo podem ocasionar imunossupressão em atletas por meio da diminuição da concentração plasmática de glutamina. O presente estudo verificou inicialmente o efeito da suplementação com L-glutamina e L-alanilL-glutamina sobre a resposta ao teste de hipersensibilidade do tipo tardio (HTT em ratos submetidos ao treinamento intenso em natação durante seis semanas. Posteriormente, foi avaliado o efeito dessas intervenções nutricionais sobre a contagem total e porcentual de leucócitos e concentração sérica de anticorpos IgG anti-albumina de soro bovino, em animais submetidos ao teste de exaustão e recuperados durante o período de 3 horas. Não houve efeito do treinamento e da suplementação sobre a resposta ao teste de HTT. Animais suplementados apresentaram maior concentração de glutamina no plasma (PIntense training and exhaustive exercise may cause immunesupression in athletes by reducing plasma glutamine concentration. Initially, this study verified the effect of L-glutamine and L-alanyl-L-glutamine supplementation on the response to delayed-type hypersensitivity test (DTH in rats submitted to intense swimming training for six weeks. Later on, we assessed the effect of these nutritional interventions on total and differential white blood cell counts and on concentration of anti-bovine serum albumin IgG antibodies, in animals submitted to exhaustion test and a three-hour recovery period. There was no effect of training and supplementation on the response to DTH. Supplemented animals presented greatest plasma glutamine concentration (p<0.05, though this increase in glutaminemia did not interfere on the serum IgG antibody concentration. The recovery period after intense exercise resulted in decreased glutaminemia as compared with the values obtained immediately after exhaustion test (p<0.05. Increase in corticosterone levels induced by strenuous exercises led to leukocytosis, neutrophilia

Cancerous epithelial cell lines shed extracellular vesicles with a bimodal size distribution that is sensitive to glutamine inhibition

International Nuclear Information System (INIS)

Santana, Steven Michael; Kirby, Brian J; Antonyak, Marc A; Cerione, Richard A

2014-01-01

Extracellular shed vesicles (ESVs) facilitate a unique mode of cell–cell communication wherein vesicle uptake can induce a change in the recipient cell's state. Despite the intensity of ESV research, currently reported data represent the bulk characterization of concentrated vesicle samples with little attention paid to heterogeneity. ESV populations likely represent diversity in mechanisms of formation, cargo and size. To better understand ESV subpopulations and the signaling cascades implicated in their formation, we characterize ESV size distributions to identify subpopulations in normal and cancerous epithelial cells. We have discovered that cancer cells exhibit bimodal ESV distributions, one small-diameter and another large-diameter population, suggesting that two mechanisms may govern ESV formation, an exosome population and a cancer-specific microvesicle population. Altered glutamine metabolism in cancer is thought to fuel cancer growth but may also support metastatic niche formation through microvesicle production. We describe the role of a glutaminase inhibitor, compound 968, in ESV production. We have discovered that inhibiting glutamine metabolism significantly impairs large-diameter microvesicle production in cancer cells. (paper)

Mixed ligand complexes of essential metal ions with L-glutamine and succinic acid in SLS-water mixtures

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Bindu Hima Gandham

2012-01-01

Full Text Available Speciation of mixed ligand complexes of Co(II, Ni(II and Cu(II with L-glutamine and succinic acid was studied in varying amounts (0.0-2.5% w/v of sodium lauryl sulphate in aqueous solutions maintaining an ionic strength of 0.16 mol L-1 (NaCl at 303.0 K. Titrations were carried out in the presence of different relative concentrations (M : L : X = 1 : 2 : 2, 1 : 4 : 2, 1 : 2 : 4 of metal (M to L-glutamine (L to succinic acid (X with sodium hydroxide. Stability constants of ternary complexes were refined with MINIQUAD75. The best-fit chemical models were selected based on statistical parameters and residual analysis. The species detected were ML2X, MLX, MLXH and MLXH2 for Co(II, Ni(II and Cu(II. Extra stability of ternary complexes compared to their binary complexes was believed to be due to electrostatic interactions of the side chains of ligands, charge neutralization, chelate effect, stacking interactions and hydrogen bonding. The species distribution with pH at different compositions of SLS and plausible equilibria for the formation of species were also presented.

Design of composite microparticle systems based on pectin and waste material of propolis for modified l-alanyl-l-glutamine release and with immunostimulant activity.

Science.gov (United States)

Villa Nova, Mônica; Ratti, Bianca A; Herculano, Leandro S; Bittencourt, Paulo R S; Novello, Cláudio R; Bazotte, Roberto Barbosa; Lautenschlager, Sueli de Oliveira Silva; Bruschi, Marcos Luciano

2017-12-12

Catabolic conditions like acquired immunodeficiency syndrome, cancer, and burn can cause immunosuppression. Amino acids such as alanine and glutamine are essential for the activity of the immune system. Propolis is immunostimulant and the waste of propolis extraction has been reused with technological and therapeutic purposes. Therefore, this study describes the association of propolis byproduct extract (BPE) with pectin to prepare spray-dried microparticles containing the dipeptide l-alanyl-l-glutamine as stimulant systems of neutrophils. The use of a factorial design allowed selecting the best formulation, which was characterized by morphology, size, and entrapment efficiency analyses. In addition, the systems were characterized by thermal and X-ray diffraction analysis, Fourier-transform infrared spectroscopy, in vitro drug release, and in vitro cytotoxicity and stimulation test of neutrophils. Small well-structured microparticles with good entrapment efficiency values were achieved. Thermal stability of formulation was observed, and it was proved that pectin, BPE and l-alanyl-l-glutamine were dispersed throughout the matrix. The drug was released from the microparticles during 24 h governed by swelling and diffusion. The drug-loaded formulations showed a significant stimulating effect on neutrophils. These structures could increase the activity of immune cells, and other in vitro and in vivo studies should be performed in the future.

A randomised trial of enteral glutamine supplementation for very preterm children showed no beneficial or adverse long-term neurodevelopmental outcomes

NARCIS (Netherlands)

Twilhaar, E.S.; de Kieviet, J.F.; Oosterlaan, J.; van Elburg, R.M.

2017-01-01

Aim This study evaluated the long-term effects of enteral glutamine supplementation on neurodevelopmental outcomes of a Dutch cohort of very preterm children at 13 years of age. Methods The cohort was enrolled in a randomised placebo-controlled trial between 2001 and 2003 in which infants received

Ammonium assimilation in rice based on the occurrence of 15N and inhibition of glutamine synthetase activity

Energy Technology Data Exchange (ETDEWEB)

Magalhaes, J. R.; Huber, D. M.; Lee, T. C.; Tsai, C. Y.

1995-07-01

Assimilation of ammonium (NH4) into free amino acids and total reduced nitrogen (N) was monitored in both roots and shoots of two-week old rice seedlings supplied with 5 mM 99% (15NH4)2SO4 in aerated hydroponic culture with or without a 2 h preincubation with 1 mM methionine sulfoximine (MSX) an inhibitor of glutamine synthetase (GS) activity. 15NH4 was not assimilated into amino acids when the GS/GOGAT (glutamate synthase) cycle was inhibited by MSX. Inhibition of glutamine synthetase (GS) activity in roots with MSX increased both the amount of NH4 and the abundance of 15N labeled NH4. In contrast, the amount of Gln and Glu, and their proportions as 15N, decreased in roots when GS activity was inhibited. This research confirms the importance of GS/GOGAT in NH4 assimilation in rice roots. 15N-labeled studies indicate that NH4 ions incorporated by roots of rice are transformed primarily into glutamine (Gin) and glutamic acid (Glu) before being converted to other amino acids through transamination. The formation of amino acids such as aspartic acid (Asp) and alanine (Ala) directly from free NH4 in roots also has been reported. Translocation of free NH4 to plant shoots, based on the concentration of free NH4 in xylem exudate, has been reported in tomato, although NH4 in shoots primarily originates from nitrate reduction in the shoot. Photorespiration also can contribute to the accumulation of NH4 in leaves. The GS/GOGAT cycle appears to be primarily responsible for the assimilation of exogenously supplied NH4 and NH4 derived from nitrate reduction in leaves, as well as NH4 derived from photorespiration. Genetic evidence cited to support this conclusion includes the lethal effect of photorespiratory conditions on plant mutants deficient in chloroplast-localized GS and GOGAT activities, and the rapid accumulation of free NH4 in GS-deficient mutants under photorespiratory conditions. The present study was initiated to quantify the in vivo amino acid synthesis in rice

Ammonium assimilation in rice based on the occurrence of 15N and inhibition of glutamine synthetase activity

International Nuclear Information System (INIS)

Magalhaes, J.R.; Huber, D.M.; Lee, T.C.; Tsai, C.Y.

1995-01-01

Assimilation of ammonium (NH4) into free amino acids and total reduced nitrogen (N) was monitored in both roots and shoots of two-week old rice seedlings supplied with 5 mM 99% (15NH4)2SO4 in aerated hydroponic culture with or without a 2 h preincubation with 1 mM methionine sulfoximine (MSX) an inhibitor of glutamine synthetase (GS) activity. 15NH4 was not assimilated into amino acids when the GS/GOGAT (glutamate synthase) cycle was inhibited by MSX. Inhibition of glutamine synthetase (GS) activity in roots with MSX increased both the amount of NH4 and the abundance of 15N labeled NH4. In contrast, the amount of Gln and Glu, and their proportions as 15N, decreased in roots when GS activity was inhibited. This research confirms the importance of GS/GOGAT in NH4 assimilation in rice roots. 15N-labeled studies indicate that NH4 ions incorporated by roots of rice are transformed primarily into glutamine (Gin) and glutamic acid (Glu) before being converted to other amino acids through transamination. The formation of amino acids such as aspartic acid (Asp) and alanine (Ala) directly from free NH4 in roots also has been reported. Translocation of free NH4 to plant shoots, based on the concentration of free NH4 in xylem exudate, has been reported in tomato, although NH4 in shoots primarily originates from nitrate reduction in the shoot. Photorespiration also can contribute to the accumulation of NH4 in leaves. The GS/GOGAT cycle appears to be primarily responsible for the assimilation of exogenously supplied NH4 and NH4 derived from nitrate reduction in leaves, as well as NH4 derived from photorespiration. Genetic evidence cited to support this conclusion includes the lethal effect of photorespiratory conditions on plant mutants deficient in chloroplast-localized GS and GOGAT activities, and the rapid accumulation of free NH4 in GS-deficient mutants under photorespiratory conditions. The present study was initiated to quantify the in vivo amino acid synthesis in rice

Side-chain dynamics of a detergent-solubilized membrane protein: Measurement of tryptophan and glutamine hydrogen-exchange rates in M13 coat protein by 1H NMR spectroscopy

International Nuclear Information System (INIS)

O'Neil, J.D.J.; Sykes, B.D.

1989-01-01

M13 coat protein is a small (50 amino acids) lipid-soluble protein that becomes an integral membrane protein during the infection stage of the life cycle of the M13 phage and is therefore used as a model membrane protein. To study side-chain dynamics in the protein, the authors have measured individual hydrogen-exchange rates for a primary amide in the side chain of glutamine-15 and for the indole amine of tryptophan-26. The protein was solubilized with the use of perdeuteriated sodium dodecyl sulfate (SDS), and hydrogen-exchange rates were measured by using 1 H nuclear magnetic resonance spectroscopy. The glutamine-15 syn proton exchanged at a rate identical with that in glutamine model peptides except that the pH corresponding to minimum exchange was elevated by about 1.5 pH units. The tryptophan-26 indole amine proton exchange was biphasic, suggesting that two populations of tryptophan-26 exist. It is suggested that the two populations may reflect protein dimerization or aggregation in the SDS micelles. The pH values of minimum exchange for tryptophan-26 in both environments were also elevated by 1.3-1.9 pH units. This phenomenon is reproduced when small tryptophan- and glutamine-containing hydrophobic peptides are dissolved in the presence of SDS micelles. The electrostatic nature of this phenomenon is proven by showing that the minimum pH for exchange can be reduced by dissolving the hydrophobic peptides in the positively charged detergent micelle dodecyltrimethylammonium bromide

Inhibition of Glutamine Synthetase: A Potential Drug Target in Mycobacterium tuberculosis

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Sherry L. Mowbray

2014-08-01

Full Text Available Tuberculosis is an infectious disease caused by Mycobacterium tuberculosis. Globally, tuberculosis is second only to AIDS in mortality and the disease is responsible for over 1.3 million deaths each year. The impractically long treatment schedules (generally 6–9 months and unpleasant side effects of the current drugs often lead to poor patient compliance, which in turn has resulted in the emergence of multi-, extensively- and totally-drug resistant strains. The development of new classes of anti-tuberculosis drugs and new drug targets is of global importance, since attacking the bacterium using multiple strategies provides the best means to prevent resistance. This review presents an overview of the various strategies and compounds utilized to inhibit glutamine synthetase, a promising target for the development of drugs for TB therapy.

Reduced Hsp70 and Glutamine in Pediatric Severe Malaria Anemia

DEFF Research Database (Denmark)

Kempaiah, Prakasha; Dokladny, Karol; Karim, Zachary

2016-01-01

by decreased HSPA1A, a heat shock protein (Hsp) 70 coding gene. Hsp70 is a ubiquitous chaperone that regulates Nuclear Factor-kappa B (NF-κB) signaling and production of pro-inflammatory cytokines known to be important in malaria pathogenesis (e.g., IL-1β, IL-6 and TNF-α). Since the role of host Hsp70...... in malaria pathogenesis is unexplored, we investigated Hsp70 and molecular pathways in children with SMA. Validation experiments revealed that leukocytic HSP70 transcripts were reduced in SMA relative to non-severe malaria, and that intraleukocytic hemozoin (PfHz) was associated with lower HSP70. HSP70...... was correlated with reticulocyte production and Hb. Since glutamine (Gln) up-regulates Hsp70, modulates NF-κB activation, and attenuates over-expression of pro-inflammatory cytokines, circulating Gln was measured in children with malaria. Reduced Gln was associated with increased risk of developing SMA...

Molecular identification and characterisation of the glycine transporter (GLYT1) and the glutamine/glutamate transporter (ASCT2) in the rat lens

DEFF Research Database (Denmark)

Lim, Julie; Lorentzen, Karen Axelgaard; Kistler, Joerg

2006-01-01

Glutathione (GSH) is an essential antioxidant required for the maintenance of lens transparency. In the lens, GSH is maintained at unusually high concentrations as a result of direct GSH uptake and/or intracellular de novo synthesis from its precursor amino acids; cysteine, glycine and glutamine/...

Effects of alanyl-glutamine supplementation on the small intestinal mucosa barrier in weaned piglets

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Shen Xing

2017-02-01

Full Text Available Objective The study was to investigate the effects of alanyl-glutamine (Ala-Gln and glutamine (Gln supplementation on the intestinal mucosa barrier in piglets. Methods A total of 180 barrows with initial weight 10.01±0.03 kg were randomly allocated to three treatments, and each treatment consisted of three pens and twenty pigs per pen. The piglets of three groups were fed with control diet [0.62% alanine (Ala], Ala-Gln diet (0.5% Ala-Gln, Gln diet (0.34% Gln and 0.21% Ala, respectively. Results The results showed that in comparison with control diet, dietary Ala-Gln supplementation increased the height of villi in duodenum and jejunum (p<0.05, Gln supplementation increased the villi height of jejunum (p<0.05, Ala-Gln supplementation up-regulated the mRNA expressions of epidermal growth factor receptor and insulin-like growth factor 1 receptor in jejunal mucosa (p<0.05, raised the mRNA expressions of Claudin-1, Occludin, zonula occludens protein-1 (ZO-1 and the protein levels of Occludin, ZO-1 in jejunal mucosa (p<0.05, Ala-Gln supplementation enlarged the number of goblet cells in duodenal and ileal epithelium (p<0.05, Gln increased the number of goblet cells in duodenal epithelium (p<0.05 and Ala-Gln supplementation improved the concentrations of secretory immunoglobulin A and immunoglobulin G in the jejunal mucosa (p<0.05. Conclusion These results demonstrated that dietary Ala-Gln supplementation could maintain the integrity of small intestine and promote the functions of intestinal mucosa barriers in piglets.

The role of adrenal hormones in the response of glutamine synthetase to fasting in adult and old rats.

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Mezzarobba, V; Torrent, A; Leydier, I; Alles, S; Brajon, B; Mignon, M; Attaix, D; Meynial-Denis, D

2003-12-01

During fasting, skeletal muscle exports increased amounts of glutamine (Gln) while increasing the production of this amino acid by glutamine synthetase (GS) in order to maintain the intramuscular Gln pool. Glucocorticoid hormones are believed to be the principal mediators of GS induction during stress conditions. The aim of this study was to evaluate (1) the effect of fasting on GS activity and expression in skeletal muscle during aging and consequently, (2) the role of glucocorticoids in fasting-induced GS activity. Male Wistar rats (6-, 22-month old) were fasted for 5 days and both the activity and expression of GS were measured in tibialis anterior muscle. To better demonstrate the role of glucocorticoids in the response of GS to fasting, we suppressed their action by RU38486 administration (a potent glucocorticoid antagonist) and their production by adrenalectomy in fed and fasted rats. An increase in fasting-induced GS activity was observed in skeletal muscles from both adult and aged rats. Adrenalectomy, but surprisingly not RU38486, suppressed the fasting-induced increase in GS activity and expression. The data clearly show that the GS responsiveness to fasting was not modified by aging in skeletal muscle.

Glutamate/glutamine metabolism coupling between astrocytes and glioma cells: neuroprotection and inhibition of glioma growth.

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Yao, Pei-Sen; Kang, De-Zhi; Lin, Ru-Ying; Ye, Bing; Wang, Wei; Ye, Zu-Cheng

2014-07-18

Glioma glutamate release has been shown to promote the growth of glioma cells and induce neuronal injuries from epilepsy to neuronal death. However, potential counteractions from normal astrocytes against glioma glutamate release have not been fully evaluated. In this study, we investigated the glutamate/glutamine cycling between glioma cells and astrocytes and their impact on neuronal function. Co-cultures of glioma cells with astrocytes (CGA) in direct contact were established under different mix ratio of astrocyte/glioma. Culture medium conditioned in these CGAs were sampled for HPLC measurement, for neuronal ratiometric calcium imaging, and for neuronal survival assay. We found: (1) High levels of glutaminase expression in glioma cells, but not in astrocytes, glutaminase enables glioma cells to release large amount of glutamate in the presence of glutamine. (2) Glutamate levels in CGAs were directly determined by the astrocyte/glioma ratios, indicating a balance between glioma glutamate release and astrocyte glutamate uptake. (3) Culture media from CGAs of higher glioma/astrocyte ratios induced stronger neuronal Ca(2+) response and more severe neuronal death. (4) Co-culturing with astrocytes significantly reduced the growth rate of glioma cells. These results indicate that normal astrocytes in the brain play pivotal roles in glioma growth inhibition and in reducing neuronal injuries from glioma glutamate release. However, as tumor growth, the protective role of astrocytes gradually succumb to glioma cells. Copyright © 2014 Elsevier Inc. All rights reserved.

BLOOD AMMONIA AND GLUTAMINE AS PREDICTORS OF HYPERAMMONEMIC CRISES IN UREA CYCLE DISORDER PATIENTS

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Lee, Brendan; Diaz, George A.; Rhead, William; Lichter-Konecki, U.; Feigenbaum, Annette; Berry, Susan A.; Le Mons, C.; Bartley, James A; Longo, Nicola; Nagamani, Sandesh C.; Berquist, William; Gallagher, Renata; Bartholomew, Dennis; Harding, Cary O.; Korson, Mark S.; McCandless, Shawn E.; Smith, Wendy; Cederbaum, Stephen; Wong, Derek; Merritt, J. Lawrence; Schulze, A.; Vockley, Gerard.; Kronn, David; Zori, Roberto; Summar, Marshall; Milikien, D.A.; Marino, M.; Coakley, D.F.; Mokhtarani, M.; Scharschmidt, B.F.

2014-01-01

Purpose To examine predictors of ammonia exposure and hyperammonemic crises (HAC) in patients with urea cycle disorders (UCDs). Methods The relationships between fasting ammonia, daily ammonia exposure, and HACs were analyzed in >100 UCD patients. Results Fasting ammonia correlated strongly with daily ammonia exposure (r=0.764, p200% (purea nitrogen. Fasting glutamine correlated weakly with AUC0-24 and was not a significant predictor of HACs. Conclusions Fasting ammonia correlates strongly and positively with daily ammonia exposure and with the risk and rate of HACs, suggesting that UCD patients may benefit from tight ammonia control. PMID:25503497

Functional and Transcriptomic Characterization of Peritoneal Immune-Modulation by Addition of Alanyl-Glutamine to Dialysis Fluid.

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Herzog, Rebecca; Kuster, Lilian; Becker, Julia; Gluexam, Tobias; Pils, Dietmar; Spittler, Andreas; Bhasin, Manoj K; Alper, Seth L; Vychytil, Andreas; Aufricht, Christoph; Kratochwill, Klaus

2017-07-24

Peritonitis remains a major cause of morbidity and mortality during chronic peritoneal dialysis (PD). Glucose-based PD fluids reduce immunological defenses in the peritoneal cavity. Low concentrations of peritoneal extracellular glutamine during PD may contribute to this immune deficit. For these reasons we have developed a clinical assay to measure the function of the immune-competent cells in PD effluent from PD patients. We then applied this assay to test the impact on peritoneal immune-competence of PD fluid supplementation with alanyl-glutamine (AlaGln) in 6 patients in an open-label, randomized, crossover pilot trial (EudraCT 2012-004004-36), and related the functional results to transcriptome changes in PD effluent cells. Ex-vivo stimulation of PD effluent peritoneal cells increased release of interleukin (IL) 6 and tumor necrosis factor (TNF) α. Both IL-6 and TNF-α were lower at 1 h than at 4 h of the peritoneal equilibration test but the reductions in cytokine release were attenuated in AlaGln-supplemented samples. AlaGln-supplemented samples exhibited priming of IL-6-related pathways and downregulation of TNF-α upstream elements. Results from measurement of cytokine release and transcriptome analysis in this pilot clinical study support the conclusion that suppression of PD effluent cell immune function in human subjects by standard PD fluid is attenuated by AlaGln supplementation.

Sensitive, specific radioisotope assay for L-glutamine-D-fructose-6- phosphat aminotransferase

International Nuclear Information System (INIS)

Callahan, M.; Tourian, A.; Hung, W.Y.

1981-01-01

A sensitive and specific radioassay for L-glutamine-D-fructose-6-phosphate aminotransferase (EC 5.3.1.19) activity is presented. Picomoles of product are measurable, and the assay can be applied to systems having limited quantities of available protein, particularly in extracts of either cell or organ cultures. The assay is at least 10,000 times more sensitive under K 1 concentrations of fructose 6-phosphate than the modified Elson-Morgan colorimetric assay and 20 times more sensitive under saturating conditions of fructose 6-phosphate. As little as 0.5 μg of cell-extract protein will yield measurable product. In contrast, 280 μg of crude-extract protein from colon is required with the modified Elson-Morgan colorimetric assay

Glutamina: aspectos bioquímicos, metabólicos, moleculares e suplementação Glutamine: biochemical, metabolic, molecular aspects and supplementation

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Vinicius Fernandes Cruzat

2009-10-01

Full Text Available A glutamina é o aminoácido livre mais abundante no plasma e no tecido muscular. Nutricionalmente é classificada como um aminoácido não essencial, uma vez que pode ser sintetizada pelo organismo a partir de outros aminoácidos. A glutamina está envolvida em diferentes funções, tais como a proliferação e desenvolvimento de células, o balanço acidobásico, o transporte da amônia entre os tecidos, a doação de esqueletos de carbono para a gliconeogênese, a participação no sistema antioxidante e outras. Por meio de técnicas de biologia molecular, estudos demonstram que a glutamina pode também influenciar diversas vias de sinalização celular, em especial a expressão de proteínas de choque térmico (HSPs. As HSPs contribuem para a manutenção da homeostasia da célula na presença de agentes estressores, tais como as espécies reativas de oxigênio (ERO. Em situações de elevado catabolismo muscular, como após exercícios físicos intensos e prolongados, a concentração de glutamina pode tornar-se reduzida. A menor disponibilidade desse aminoácido pode diminuir a resistência da célula a lesões, levando a processos de apoptose celular. Por essas razões, a suplementação com L-glutamina, tanto na forma livre, quanto como dipeptídeo, tem sido investigada. Alguns aspectos bioquímicos, metabólicos e mecanismos moleculares da glutamina, bem como os efeitos de sua suplementação, são abordados no presente trabalho.Glutamine is the most frequent free amino acid in the serum and muscular tissue. Nutritionally, it is classified as a non-essential amino acid, once it can be synthesized by the body from other amino acids. Glutamine is involved in different functions, such as cell proliferation and development, basic acid balance, ammonia transportation between tissues, carbon skeleton donation to the gluconeogenesis, participation in the antioxidant system, among others. Molecular biology techniques show that it may also

Enzymatic-fluorometric analyses for glutamine, glutamate and free amino groups in protein-free plasma and milk

DEFF Research Database (Denmark)

Larsen, Torben; Fernández, Carlos J.

2017-01-01

This Technical Research Communication describes new analytical methods for free, unbound glutamic acid and glutamine in protein-free blood plasma and milk and introduces the use of quantitation of free amino groups in the same matrices for descriptive and analytical purposes. The present enzymatic......-fluorometric methods are easily performed within one working day, allowing for ‘high throughput’ assays of animal trials. These assays could support and enable further studies in lactation physiology with the objective of improved metabolic health....

Glucose, Lactate, β-Hydroxybutyrate, Acetate, GABA, and Succinate as Substrates for Synthesis of Glutamate and GABA in the Glutamine-Glutamate/GABA Cycle.

Science.gov (United States)

Hertz, Leif; Rothman, Douglas L

2016-01-01

The glutamine-glutamate/GABA cycle is an astrocytic-neuronal pathway transferring precursors for transmitter glutamate and GABA from astrocytes to neurons. In addition, the cycle carries released transmitter back to astrocytes, where a minor fraction (~25 %) is degraded (requiring a similar amount of resynthesis) and the remainder returned to the neurons for reuse. The flux in the cycle is intense, amounting to the same value as neuronal glucose utilization rate or 75-80 % of total cortical glucose consumption. This glucose:glutamate ratio is reduced when high amounts of β-hydroxybutyrate are present, but β-hydroxybutyrate can at most replace 60 % of glucose during awake brain function. The cycle is initiated by α-ketoglutarate production in astrocytes and its conversion via glutamate to glutamine which is released. A crucial reaction in the cycle is metabolism of glutamine after its accumulation in neurons. In glutamatergic neurons all generated glutamate enters the mitochondria and its exit to the cytosol occurs in a process resembling the malate-aspartate shuttle and therefore requiring concomitant pyruvate metabolism. In GABAergic neurons one half enters the mitochondria, whereas the other one half is released directly from the cytosol. A revised concept is proposed for the synthesis and metabolism of vesicular and nonvesicular GABA. It includes the well-established neuronal GABA reuptake, its metabolism, and use for resynthesis of vesicular GABA. In contrast, mitochondrial glutamate is by transamination to α-ketoglutarate and subsequent retransamination to releasable glutamate essential for the transaminations occurring during metabolism of accumulated GABA and subsequent resynthesis of vesicular GABA.

Synthesis, characterization, and biological evaluation of poly(L-γ-glutamyl-glutamine-paclitaxel nanoconjugate

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Sang Van

2010-10-01

Full Text Available Sang Van1, Sanjib K Das1, Xinghe Wang1, Zhongling Feng1, Yi Jin1, Zheng Hou1, Fu Chen1, Annie Pham1, Nan Jiang1, Stephen B Howell2, Lei Yu11Nitto Denko Technical Corporation, Oceanside, CA, USA; 2Moores Cancer Center, University of California, La Jolla, San Diego, CA, USAAbstract: The purpose of this study was to develop a novel, highly water-soluble poly(L-γ-glutamyl-glutamine-paclitaxel nanoconjugate (PGG-PTX that would improve the therapeutic index of paclitaxel (PTX. PGG-PTX is a modification of poly(L-glutamic acid-paclitaxel conjugate (PGA-PTX in which an additional glutamic acid has been added to each glutamic side chain in the polymer. PGG-PTX has higher water-solubility and faster dissolution than PGA-PTX. Unlike PGA-PTX, PGG-PTX self-assembles into nanoparticles, whose size remains in the range of 12–15 nm over the concentration range from 25 to 2,000 µg/mL in saline. Its critical micellar concentration in saline was found to be ~25 µg/mL. The potency of PGG-PTX when tested in vitro against the human lung cancer H460 cell line was comparable to other known polymer-PTX conjugates. However, PGG-PTX possesses lower toxicity compared with PGA-PTX in mice. The maximum tolerated dose of PGG-PTX was found to be 350 mg PTX/kg, which is 2.2-fold higher than the maximum tolerated dose of 160 mg PTX/kg reported for the PGA-PTX. This result indicates that PGG-PTX was substantially less toxic in vivo than PGA-PTX.Keywords: nanoconjugates, poly(L-glutamic acid, poly(L-γ-glutamyl-glutamine-paclitaxel, nanoparticles, anticancer

Synthesis, spectral characterization and biological studies of some organotin(IV) complexes of L-proline, trans-hydroxy- L-proline and L-glutamine

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Nath, Mala; Jairath, Ruchi; Eng, George; Song, Xueqing; Kumar, Ashok

2005-12-01

New organotin(IV) complexes of the general formula R 3Sn(L) (where R = Me, n-Bu and HL = L-proline; R = Me, Ph and HL = trans-hydroxy- L-proline and L-glutamine) and R 2Sn(L) 2 (where R = n-Bu, Ph and HL = L-proline; R = Ph, HL = trans-hydroxy- L-proline) have been synthesized by the reaction of R nSnCl 4- n (where n = 2 or 3) with sodium salt of the amino acid (HL). n-Bu 2Sn(Pro) 2 was synthesized by the reaction of n-Bu 2SnO with L-proline under azeotropic removal of water. The bonding and coordination behavior in these complexes have been discussed on the basis of IR and 119Sn Mössbauer spectroscopic studies in the solid-state. Their coordination behavior in solution has been discussed with the help of multinuclear ( 1H, 13C and 119Sn) NMR spectral studies. The 119Sn Mössbauer and IR studies indicate that L-proline and trans-hydroxy- L-proline show similar coordination behavior towards organotin(IV) compounds. Pentacoordinate trigonal-bipyramidal and hexacoordinate octahedral structures, respectively, have been proposed for the tri- and diorganotin(IV) complexes of L-proline and trans-hydroxy- L-proline, in which the carboxylate group acts as bidentate group. L-Glutamine shows different coordination behavior towards organotin(IV) compounds, it acts as monoanionic bidentate ligand coordinating through carboxylate and amino group. The triorganotin(IV) complexes of L-glutamine have been proposed to have trigonal-bipyramidal environment around tin. The newly synthesized complexes have been tested for their antiinflammatory and cardiovascular activities. Their LD 50 values are >1000 mg kg -1.

Metabolite profile of koji amazake and its lactic acid fermentation product by Lactobacillus sakei UONUMA.

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Oguro, Yoshifumi; Nishiwaki, Toshikazu; Shinada, Ryota; Kobayashi, Kazuya; Kurahashi, Atsushi

2017-08-01

The koji amazake is a traditional sweet Japanese beverage. It has been consumed for over a thousand years in Japan; nonetheless, little is yet known of the ingredients in koji amazake. Therefore, this study aimed to analyze the metabolites of koji amazake using a metabolomics approach. Additionally, we reformed the flavor of koji amazake by lactic acid fermentation (LAF-amazake) using Lactobacillus sakei UONUMA, which was isolated from snow caverns. The purpose of this article is to identify the ingredients in these beverages. In LAF-amazake and koji amazake, sugars, amino acids, organic acids, and vitamin B complex were determined in the two beverages, and over 300 compounds were detected in total. Thirteen saccharides were identified including two unknown trisaccharides, and there were no differences in these between the two beverages. In LAF-amazake, lactic acid, vitamin B2 (riboflavin), B3 (nicotinic acid and nicotinamide), and B6 (pyridoxine) were significantly increased as compared to koji amazake, whereas malate and glutamine decreased. These results suggested that LAF, malolactic fermentation, and glutamine deamidation occurred simultaneously in LAF-amazake. L. sakei UONUMA strains produced these vitamins. Moreover, it was surprising that acetylcholine, a well-known neurotransmitter, was newly generated in LAF-amazake. Here, we have succeeded in reforming the flavor of koji amazake and obtained these metabolic data on the two beverages. The present study could provide useful basic information for promoting functional analyses of koji amazake and LAF-amazake for human health. Copyright © 2017 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Nano-Nutrition of Chicken Embryos. The Effect of in Ovo Administration of Diamond Nanoparticles and l-Glutamine on Molecular Responses in Chicken Embryo Pectoral Muscles

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Marta Grodzik

2013-11-01

Full Text Available It has been demonstrated that the content of certain amino acids in eggs is not sufficient to fully support embryonic development. One possibility to supply the embryo with extra nutrients and energy is in ovo administration of nutrients. Nanoparticles of diamond are highly biocompatible non-toxic carbonic structures, and we hypothesized that bio-complexes of diamond nanoparticles with l-glutamine may affect molecular responses in breast muscle. The objective of the investigation was to evaluate the effect of diamond nanoparticle (ND and l-glutamine (Gln on expression of growth and differentiation factors of chicken embryo pectoral muscles. ND, Gln, and Gln/ND solutions (50 mg/L were injected into fertilized broiler chicken eggs at the beginning of embryogenesis. Muscle tissue was dissected at day 20 of incubation and analysed for gene expression of FGF2, VEGF-A, and MyoD1. ND and especially Gln/ND up-regulated expression of genes related to muscle cell proliferation (FGF2 and differentiation (MyoD1. Furthermore, the ratio between FGF2 and MyoD1 was highest in the Gln/ND group. At the end of embryogenesis, Gln/ND enhanced both proliferation and differentiation of pectoral muscle cells and differentiation dominated over proliferation. These preliminary results suggest that the bio-complex of glutamine and diamond nanoparticles may accelerate growth and maturation of muscle cells.

The amino acid transporters of the glutamate/GABA-glutamine cycle and their impact on insulin and glucagon secretion

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Monica eJenstad

2013-12-01

Full Text Available Intercellular communication is pivotal in optimising and synchronising cellular responses to keep internal homeostasis and to respond adequately to external stimuli. In the central nervous system (CNS, glutamatergic and GABAergic signals are postulated to be dependent on the glutamate/GABA-glutamine (GGG cycle for vesicular loading of neurotransmitters, for inactivating the signal and for the replenishment of the neurotransmitters. Islets of Langerhans release the hormones insulin and glucagon, but share similarities with CNS cells in for example transcriptional control of development and differentiation, and chromatin methylation. Interestingly, proteins involved in the CNS in secretion of the neurotransmitters and emitting their responses as well as the regulation of these processes, are also found in islet cells. Moreover, high levels of glutamate, GABA and glutamine and their respective vesicular and plasma membrane transporters have been shown in the islet cells and there is emerging support for these amino acids and their transporters playing important roles in the maturation and secretion of insulin and glucagon. In this review, we will discuss the feasibility of recent data in the field in relation to the biophysical properties of the transporters (Slc1, Slc17, Slc32 and Slc38 and physiology of hormone secretion in islets of Langerhans.

Relationship among Glutamine, γ-Aminobutyric Acid, and Social Cognition in Autism Spectrum Disorders

Science.gov (United States)

Sikoglu, Elif M.; Hodge, Steven M.; Edden, Richard A.E.; Foley, Ann; Kennedy, David N.; Moore, Constance M.; Frazier, Jean A.

2015-01-01

Abstract Objective: An imbalance of excitatory and inhibitory neurotransmission in autism spectrum disorder (ASD) has been proposed. We compared glutamate (Glu), glutamine (Gln), and γ-aminobutyric acid (GABA) levels in the anterior cingulate cortex (ACC) of 13 males with ASD and 14 typically developing (TD) males (ages 13–17), and correlated these levels with intelligence quotient (IQ) and measures of social cognition. Methods: Social cognition was evaluated by administration of the Social Responsiveness Scale (SRS) and the Reading the Mind in the Eyes Test (RMET). We acquired proton magnetic resonance spectroscopy (1H-MRS) data from the bilateral ACC using the single voxel point resolved spectroscopy sequence (PRESS) to quantify Glu and Gln, and Mescher–Garwood point-resolved spectroscopy sequence (MEGA-PRESS) to quantify GABA levels referenced to creatine (Cr). Results: There were higher Gln levels (p=0.04), and lower GABA/Cre levels (p=0.09) in the ASD group than in the TD group. There was no difference in Glu levels between groups. Gln was negatively correlated with RMET score (rho=−0.62, p=0.001) and IQ (rho=−0.56, p=0.003), and positively correlated with SRS scores (rho=0.53, p=0.007). GABA/Cre levels were positively correlated with RMET score (rho=0.34, p=0.09) and IQ (rho=0.36, p=0.07), and negatively correlated with SRS score (rho=−0.34, p=0.09). Conclusions: These data suggest an imbalance between glutamatergic neurotransmission and GABA-ergic neurotransmission in ASD. Higher Gln levels and lower GABA/Cre levels were associated with lower IQ and greater impairments in social cognition across groups. PMID:25919578

Metabolic Cooperation of Glucose and Glutamine Is Essential for the Lytic Cycle of Obligate Intracellular Parasite Toxoplasma gondii*

OpenAIRE

Nitzsche, Richard; Zagoriy, Vyacheslav; Lucius, Richard; Gupta, Nishith

2015-01-01

Toxoplasma gondii is a widespread protozoan parasite infecting nearly all warm-blooded organisms. Asexual reproduction of the parasite within its host cells is achieved by consecutive lytic cycles, which necessitates biogenesis of significant energy and biomass. Here we show that glucose and glutamine are the two major physiologically important nutrients used for the synthesis of macromolecules (ATP, nucleic acid, proteins, and lipids) in T. gondii, and either of them is sufficient to ensure ...

Astrocytes and Glutamate Homoeostasis in Alzheimer's Disease: A Decrease in Glutamine Synthetase, But Not in Glutamate Transporter-1, in the Prefrontal Cortex

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Magdalena Kulijewicz-Nawrot

2013-09-01

Full Text Available Astrocytes control tissue equilibrium and hence define the homoeostasis and function of the CNS (central nervous system. Being principal homoeostatic cells, astroglia are fundamental for various forms of neuropathology, including AD (Alzheimer's disease. AD is a progressive neurodegenerative disorder characterized by the loss of cognitive functions due to specific lesions in mnesic-associated regions, including the mPFC (medial prefrontal cortex. Here, we analyzed the expression of GS (glutamine synthetase and GLT-1 (glutamate transporter-1 in astrocytes in the mPFC during the progression of AD in a triple-transgenic mouse model (3xTg-AD. GS is an astrocyte-specific enzyme, responsible for the intracellular conversion of glutamate into glutamine, whereas the removal of glutamate from the extracellular space is accomplished mainly by astroglia-specific GLT-1. We found a significant decrease in the numerical density (Nv, cells/mm3 of GS-positive astrocytes from early to middle ages (1–9 months; at the age of 1 month by 17%, 6 months by 27% and 9 months by 27% when compared with control animals in parallel with a reduced expression of GS (determined by Western blots, which started at the age of 6 months and was sustained up to 12 months of age. We did not, however, find any changes in the expression of GLT-1, which implies an intact glutamate uptake mechanism. Our results indicate that the decrease in GS expression may underlie a gradual decline in the vital astrocyte-dependent glutamate–glutamine conversion pathway, which in turn may compromise glutamate homoeostasis, leading towards failures in synaptic connectivity with deficient cognition and memory.

Analysis and physiological implications of renal 2-oxoglutaramate metabolism.

Science.gov (United States)

Nissim, I; Wehrli, S; States, B; Nissim, I; Yudkoff, M

1991-07-01

The relative significance of the flux through the glutamine aminotransferase (glutaminase II) pathway to renal ammoniagenesis is poorly understood. A basic and unresolved question is whether 2-oxoglutaramate (2-OGM), a product of the glutaminase II reaction, is deamidated to yield 2-oxoglutarate and NH3, or whether 2-OGM accumulates as an unreactive lactam, depending on the environmental pH. In the current studies we utilized 13C n.m.r. as well as 15N n.m.r. as well as 15N n.m.r. to demonstrate that 2-OGM occurs as a lactam, i.e. 5-hydroxypyroglutamate, regardless of the environmental pH. Our additional aims were to determine whether human kidney cells (HK cells) in culture can produce 2-OGM and to ascertain a pH-dependent relationship between NH3 and 2-OGM production from glutamine. We therefore developed an isotope dilution assay for 2-OGM utilizing 5-hydroxy[4-13C,1-15N]pyroglutamate as the labelled species. Incubations of HK cells in minimal essential medium supplemented with 1 mM-[2-15N]glutamine demonstrated significantly higher production of 2-OGM at pH 6.8 and lower production at pH 7.6 compared with pH 7.4. Similarly both 15NH3 and [15N]alanine formation were significantly higher in acute acidosis (pH 6.8) and lower in acute alkalosis (pH 7.6) compared with that at physiological pH. Addition of 1 mM-amino-oxyacetate to the incubation medium at pH 7.4 significantly diminished [15N]alanine and 2-OGM production, but the production of 15NH3 via the glutamate dehydrogenase pathway was significantly stimulated. The current observations indicate that the glutaminase II pathway plays a minor role and that flux through glutamate dehydrogenase is the predominant site for regulation of ammoniagenesis in human kidney.

Contribution of glutamate decarboxylase in Lactobacillus reuteri to acid resistance and persistence in sourdough fermentation.

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Su, Marcia S; Schlicht, Sabine; Gänzle, Michael G

2011-08-30

Acid stress impacts the persistence of lactobacilli in industrial sourdough fermentations, and in intestinal ecosystems. However, the contribution of glutamate to acid resistance in lactobacilli has not been demonstrated experimentally, and evidence for the contribution of acid resistance to the competitiveness of lactobacilli in sourdough is lacking. It was therefore the aim of this study to investigate the ecological role of glutamate decarboxylase in L. reuteri. A gene coding for a putative glutamate decarboxylase, gadB, was identified in the genome of L. reuteri 100-23. Different from the organization of genetic loci coding for glutamate decarboxylase in other lactic acid bacteria, gadB was located adjacent to a putative glutaminase gene, gls3. An isogenic deletion mutant, L. reuteri ∆gadB, was generated by a double crossover method. L. reuteri 100-23 but not L. reuteri ∆gadB converted glutamate to γ-aminobutyrate (GABA) in phosphate butter (pH 2.5). In sourdough, both strains converted glutamine to glutamate but only L. reuteri 100-23 accumulated GABA. Glutamate addition to phosphate buffer, pH 2.5, improved survival of L. reuteri 100-23 100-fold. However, survival of L. reuteri ∆gadB remained essentially unchanged. The disruption of gadB did not affect growth of L. reuteri in mMRS or in sourdough. However, the wild type strain L. reuteri 100-23 displaced L. reuteri ∆gadB after 5 cycles of fermentation in back-slopped sourdough fermentations. The conversion of glutamate to GABA by L. reuteri 100-23 contributes to acid resistance and to competitiveness in industrial sourdough fermentations. The organization of the gene cluster for glutamate conversion, and the availability of amino acids in cereals imply that glutamine rather than glutamate functions as the substrate for GABA formation. The exceptional coupling of glutamine deamidation to glutamate decarboxylation in L. reuteri likely reflects adaptation to cereal substrates.

Labeling of amino acid (L-Glutamine) with technetium-99m and biological evaluation

International Nuclear Information System (INIS)

Ahmed, S. S.; Abass, S. A. E.; Karim, L. M.; Risan, R. H.; Abdulkarim, H. M.; Zia, M. A.; Manjy, A.N.; Hamed, S. A.

2012-12-01

The study of labeling of some amino acid 9 9mT c has been carried before (1, 2). Some were found to be chemically valuable, while some others had no clinical value although, they provided US with knowledge on the mechanism of labeling and biodistribution. In this paper we experimented the possibility of labeling L-Glutamine with Tc 9 '9 m and studied its biological behavior the study revealed that the optimal pH for the formation of higher percentage of the complex is about (2.5-2.55). Biodistribution carried in balb/c mice showed that the complex accumulates in soft tissue of the abdomen. This fining may indicate good clinical value in diagnosis of soft tissue tumors of lesion. (Author)

Suplementação enteral e parenteral com glutamina em neonatos pré-termo e com baixo peso ao nascer Enteral and parenteral supplementation with glutamine in preterm and low-birth-weight neonates

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Maria Carolina Borges

2008-03-01

Full Text Available A glutamina é o aminoácido livre mais abundante no sangue e no músculo esquelético, bem como é o principal substrato energético para células de elevado turnover, como enterócitos e leucócitos. Adicionalmente, a glutamina representa o principal aminoácido transferido para o feto pela placenta e, juntamente com o glutamato, constituem os aminoácidos mais abundantes no leite materno. Todavia, bebês nascidos prematuramente sofrem interrupção abrupta do fornecimento placentário de glutamina, o que acarreta em dependência exclusiva da síntese endógena ou do fornecimento exógeno deste aminoácido. Aliado a isso, neonatos pré-termo (PT e com baixo peso ao nascer (BPN, freqüentemente, recebem apenas nutrição parenteral total nas primeiras semanas de vida, a qual não contém glutamina. Cabe ainda destacar que esses bebês possuem pouca massa muscular e, portanto, seus estoques de glutamina são limitados. Uma vez que neonatos PT e com BPN estão sujeitos a intenso crescimento e a inúmeros estresses fisiológicos, é possível que a glutamina seja um nutriente condicionalmente essencial nessa fase da vida, fato que estimulou a realização de estudos com a finalidade de avaliar os possíveis benefícios clínicos da suplementação enteral e parenteral com glutamina em neonatos PT e com BPN.Glutamine is the most abundant amino acid found in the blood and skeletal muscle, and is the principal energetic substrate for cells with a high turnover, such as enterocytes and leucocytes. Furthermore, glutamine is the most important amino acid that is passed to the foetus via the placenta, and together with glutamate, is the most abundant amino acid in maternal milk. Preterm infants suffer an abrupt interruption in the supply of glutamine via the placenta, which leads to an exclusive dependence on the endogenous synthesis or the exogenous supply of this amino acid. Preterm neonates (PT as well as low-birth-weight neonates (LBW frequently

Nitrogen Control in Pseudomonas aeruginosa : A Role for Glutamine in the Regulation of the Synthesis of NADP-Dependent Glutamate Dehydrogenase, Urease and Histidase

NARCIS (Netherlands)

Janssen, Dick B.; Herst, Patricia M.; Joosten, Han M.L.J.; Drift, Chris van der

1981-01-01

In Pseudomonas aeruginosa the formation of urease, histidase and some other enzymes involved in nitrogen assimilation is repressed by ammonia in the growth medium. The key metabolite in this process appears to be glutamine or a product derived from it, since ammonia and glutamate did not repress

Effects of creep feeding and supplemental glutamine or glutamine plus glutamate (Aminogut) on pre- and post-weaning growth performance and intestinal health of piglets

Science.gov (United States)

2013-01-01

Background Creep feeding is used to stimulate piglet post-weaning feed consumption. L-Glutamine (GLN) is an important source of fuel for intestinal epithelial cells. The objective of this study was to determine the impact of creep feeding and adding GLN or AminoGut (AG; containing glutamine + glutamate) to pre- and post-weaning diets on pig performance and intestinal health. Litters (N = 120) were allotted to four treatments during 14–21 d of lactation: 1) No creep feed (NC, n = 45); 2) creep fed control diet (CFCD, n = 45); 3) creep fed 1% GLN (CFGLN, n = 15); 4) creep fed .88% AG (CFAG, n = 15). After weaning, the NC and CFCD groups were sub-divided into three groups (n = 15 each), receiving either a control nursery diet (NC-CD, CFCD-CD) or a diet supplemented with either GLN (NC-GLN, CFCD-GLN) or with AG (NC-AG, CFCD-AG). Litters that were creep fed with diets containing GLN or AG also were supplemented with those amino acids in the nursery diets (CFGLN-GLN, CFAG-AG). Glutamine was added at 1% in all three post-weaning diet phases and AG was added at .88% in phase 1 and 2 and at .66% in phase 3. Results Feed conversion (feed/gain) showed means among treatment means close to significance (P = 0.056) and Tukey’s test for pairwise mean comparisons showed that Pigs in the CFGLN-GLN group had the best feed conversion (feed/gain) in the first three-week period post-weaning, exceeding (P = 0.044) controls (CFCD-CD) by 34%. The NC-AG group had (P = 0.02) the greatest feed intake in the last three week of the study, exceeding controls (CFCD-CD) by 12%. CFGLN-GLN, CFCD-GLN and sow reared (SR) pigs had the greatest (P = 0.049) villi height exceeding the CFCD-AG group by 18%, 20% and 19% respectively. The CFAG-AG group had the deepest (P = 0.001) crypts among all treatments. CFGLN-GLN, CFCD-GLN and SR groups had the greatest (P = 0.001) number of cells proliferating (PCNA) exceeding those in the NC-CD group by 43%, 54

Effects of creep feeding and supplemental glutamine or glutamine plus glutamate (Aminogut) on pre- and post-weaning growth performance and intestinal health of piglets.

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Cabrera, Rafael A; Usry, James L; Arrellano, Consuelo; Nogueira, Eduardo T; Kutschenko, Marianne; Moeser, Adam J; Odle, Jack

2013-08-03

Creep feeding is used to stimulate piglet post-weaning feed consumption. L-Glutamine (GLN) is an important source of fuel for intestinal epithelial cells. The objective of this study was to determine the impact of creep feeding and adding GLN or AminoGut (AG; containing glutamine + glutamate) to pre- and post-weaning diets on pig performance and intestinal health. Litters (N = 120) were allotted to four treatments during 14-21 d of lactation: 1) No creep feed (NC, n = 45); 2) creep fed control diet (CFCD, n = 45); 3) creep fed 1% GLN (CFGLN, n = 15); 4) creep fed .88% AG (CFAG, n = 15). After weaning, the NC and CFCD groups were sub-divided into three groups (n = 15 each), receiving either a control nursery diet (NC-CD, CFCD-CD) or a diet supplemented with either GLN (NC-GLN, CFCD-GLN) or with AG (NC-AG, CFCD-AG). Litters that were creep fed with diets containing GLN or AG also were supplemented with those amino acids in the nursery diets (CFGLN-GLN, CFAG-AG). Glutamine was added at 1% in all three post-weaning diet phases and AG was added at .88% in phase 1 and 2 and at .66% in phase 3. Feed conversion (feed/gain) showed means among treatment means close to significance (P = 0.056) and Tukey's test for pairwise mean comparisons showed that Pigs in the CFGLN-GLN group had the best feed conversion (feed/gain) in the first three-week period post-weaning, exceeding (P = 0.044) controls (CFCD-CD) by 34%. The NC-AG group had (P = 0.02) the greatest feed intake in the last three week of the study, exceeding controls (CFCD-CD) by 12%. CFGLN-GLN, CFCD-GLN and sow reared (SR) pigs had the greatest (P = 0.049) villi height exceeding the CFCD-AG group by 18%, 20% and 19% respectively. The CFAG-AG group had the deepest (P = 0.001) crypts among all treatments. CFGLN-GLN, CFCD-GLN and SR groups had the greatest (P = 0.001) number of cells proliferating (PCNA) exceeding those in the NC-CD group by 43%, 54% and 63% respectively

Risk-Conferring Glutamatergic Genes and Brain Glutamate Plus Glutamine in Schizophrenia

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Juan R. Bustillo

2017-06-01

Full Text Available BackgroundThe proton magnetic resonance spectroscopy (1H-MRS signals from glutamate (or the combined glutamate and glutamine signal—Glx have been found to be greater in various brain regions in people with schizophrenia. Recently, the Psychiatric Genetics Consortium reported that several common single-nucleotide polymorphisms (SNPs in glutamate-related genes confer increased risk of schizophrenia. Here, we examined the relationship between presence of these risk polymorphisms and brain Glx levels in schizophrenia.Methods1H-MRS imaging data from an axial, supraventricular tissue slab were acquired in 56 schizophrenia patients and 67 healthy subjects. Glx was measured in gray matter (GM and white matter (WM regions. The genetic data included six polymorphisms genotyped across an Illumina 5M SNP array. Only three of six glutamate as well as calcium-related SNPs were available for examination. These included three glutamate-related polymorphisms (rs10520163 in CLCN3, rs12704290 in GRM3, and rs12325245 in SLC38A7, and three calcium signaling polymorphisms (rs1339227 in RIMS1, rs7893279 in CACNB2, and rs2007044 in CACNA1C. Summary risk scores for the three glutamate and the three calcium polymorphisms were calculated.ResultsGlx levels in GM positively correlated with glutamate-related genetic risk score but only in younger (≤36 years schizophrenia patients (p = 0.01. Glx levels did not correlate with calcium risk scores. Glx was higher in the schizophrenia group compared to levels in controls in GM and WM regardless of age (p < 0.001.ConclusionElevations in brain Glx are in part, related to common allelic variants of glutamate-related genes known to increase the risk for schizophrenia. Since the glutamate risk scores did not differ between groups, some other genetic or environmental factors likely interact with the variability in glutamate-related risk SNPs to contribute to an increase in brain Glx early in the illness.

Glutamina e turnover do carbono da mucosa intestinal de leitões desmamados Glutamine and carbon turnover of the intestinal mucosa of weaned piglets

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Fabiana Ribeiro Caldara

2010-12-01

Full Text Available Um experimento foi conduzido para verificar a influência da glutamina no turnover do carbono na mucosa intestinal de leitões desmamados. Nove matrizes receberam dietas compostas basicamente de plantas do ciclo fotossintético C4 durante toda a gestação (d‰13C = 17,12 e lactação (d‰13C = -19,26. Os leitões foram desmamados aos 21 dias de idade e 68 deles foram alimentados com ração composta de plantas do ciclo fotossintético C3 (d‰13C = -25,12. Os leitões foram aleatoriamente distribuídos em duas dietas: uma sem suplementação de glutamina; e outra suplementada com 1% de glutamina. Aos 0; 1; 1,5; 2; 2,5; 3; 3,5; 4; 4,5; 5; 5,5; 8; 11; 15, 20; 29 e 46 dias pós-desmame, dois leitões de cada dieta foram abatidos para coleta de amostras da mucosa intestinal, que foram analisadas quanto à composição isotópica de d‰13C e mensurada a velocidade de substituição do carbono no tempo. Os valores da meia-vida do carbono para a mucosa intestinal foram de 6,0 e 3,5 dias para as dietas controle e com glutamina, respectivamente. A glutamina acelerou a velocidade de substituição do carbono na mucosa intestinal, evidenciando sua ação benéfica na recuperação da estrutura do intestino após o desmame.An experiment was carried out to evaluate the influence of glutamine on the carbon turnover in the intestinal mucosa of weaned piglets. Nine matrices received diets predominantly composed by photosintetic cycle C4 plants during the gestation (d‰13C = -17.12 and lactation (d‰13C = -19.26. The piglets were weaned at 21 days of age, and 68 animals were fed rations composed by photosintetic cycle C3 plants (d‰13C = -25.12. The piglets were distributed at random in two treatments: one diet without glutamine supplementation and the other diet supplemented with 1% of glutamine. On days 0; 1; 1.5; 2; 2.5; 3; 3.5; 4; 4.5; 5; 5.5; 8; 11; 15, 20; 29 and 46 after weaning, two piglets from each diet were slaughtered for collection of samples

Specificity of exogenous acetate and glutamate as astrocyte substrates examined in acute brain slices from female mice using methionine sulfoximine (MSO) to inhibit glutamine synthesis

DEFF Research Database (Denmark)

Andersen, Jens Velde; McNair, Laura Frendrup; Schousboe, Arne

2017-01-01

Removal of endogenously released glutamate is mediated primarily by astrocytes and exogenous (13) C-labeled glutamate has been applied to study glutamate metabolism in astrocytes. Likewise, studies have clearly established the relevance of (13) C-labeled acetate as an astrocyte specific metabolic...... cortical slices from female NMRI mice were incubated in media containing [1,2-(13) C]acetate or [U-(13) C]glutamate, with or without methionine sulfoximine (MSO) to inhibit glutamine synthetase (GS). Tissue extracts were analyzed by gas chromatography-mass spectrometry. Blocking GS abolished the majority...... of glutamine (13) C-labeling from [1,2-(13) C]acetate as intended. However, (13) C-labeling of GABA was only 40-50% reduced by MSO, suggesting considerable neuronal uptake of acetate. Moreover, labeling of glutamate from [1,2-(13) C]acetate in the presence of MSO exceeded the level probable from exclusive...

Arginyl-glutamine dipeptide or docosahexaenoic acid attenuates hyperoxia-induced small intestinal injury in neonatal mice.

Science.gov (United States)

Li, Nan; Ma, Liya; Liu, Xueyan; Shaw, Lynn; Li Calzi, Sergio; Grant, Maria B; Neu, Josef

2012-04-01

Supplementation studies of glutamine, arginine, and docosahexaenoic acid (DHA) have established the safety of each of these nutrients in neonates; however, the potential for a more stable and soluble dipeptide, arginyl-glutamine (Arg-Gln) or DHA with anti-inflammatory properties, to exert benefits on hyperoxia-induced intestinal injury has not been investigated. Arg-Gln dipeptide has been shown to prevent retinal damage in a rodent model of oxygen-induced injury. The objective of the present study was to investigate whether Arg-Gln dipeptide or DHA could also attenuate markers of injury and inflammation to the small intestine in this same model. Seven-day-old mouse pups were placed with their dams in 75% oxygen for 5 days. After 5 days of hyperoxic exposure (P7-P12), pups were removed from hyperoxia and allowed to recover in atmospheric conditions for 5 days (P12-P17). Mouse pups received Arg-Gln (5g·kg·day) or DHA (5g·kg·day) or vehicle orally started on P12 through P17. Distal small intestine (DSI) histologic changes, myeloperoxidase (MPO), lactate dehydrogenase (LDH), inflammatory cytokines, and tissue apoptosis were evaluated. Hyperoxic mice showed a greater distortion of overall villus structure and with higher injury score (PDHA supplementation groups were more similar to the room air control group. Supplementation of Arg-Gln or DHA reduced hyperoxia-induced MPO activity (PDHA returned LDH activity to the levels of control. Hyperoxia induced apoptotic cell death in DSIs, and both Arg-Gln and DHA reversed this effect (PDHA may limit some inflammatory and apoptotic processes involved in hyperoxic-induced intestinal injury in neonatal mice.

Amino acid transport across the tonoplast of vacuoles isolated from barley mesophyll protoplasts: Uptake of alanine, leucine, and glutamine

International Nuclear Information System (INIS)

Dietz, K.J.; Jaeger, R.; Kaiser, G.; Martinoia, E.

1990-01-01

Mesophyll protoplasts from leaves of well-fertilized barley (Hordeum vulgare L.) plants contained amino acids at concentrations as high as 120 millimoles per liter. With the exception of glutamic acid, which is predominantly localized in the cytoplasm, a major part of all other amino acids was contained inside the large central vacuole. Alanine, leucine, and glutamine are the dominant vacuolar amino acids in barley. Their transport into isolated vacuoles was studied using 14 C-labeled amino acids. Uptake was slow in the absence of ATP. A three- to sixfold stimulation of uptake was observed after addition of ATP or adenylyl imidodiphosphate an ATP analogue not being hydrolyzed by ATPases. Other nucleotides were ineffective in increasing the rate of uptake. ATP-Stimulated amino acid transport was not dependent on the transtonoplast pH or membrane potential. p-Chloromercuriphenylsulfonic acid and n-ethyl maleimide increased transport independently of ATP. Neutral amino acids such as valine or leucine effectively decreased the rate of alanine transport. Glutamine and glycine were less effective or not effective as competitive inhibitors of alanine transport. The results indicate the existence of a uniport translocator specific for neutral or basic amino acids that is under control of metabolic effectors

Examination of the efficacy of acute L-alanyl-L-glutamine ingestion during hydration stress in endurance exercise

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Yamamoto Linda M

2010-02-01

Full Text Available Abstract Background The effect of acute L-alanyl-L-glutamine (AG; Sustamine™ ingestion on performance changes and markers of fluid regulation, immune, inflammatory, oxidative stress, and recovery was examined in response to exhaustive endurance exercise, during and in the absence of dehydration. Methods Ten physically active males (20.8 ± 0.6 y; 176.8 ± 7.2 cm; 77.4 ± 10.5 kg; 12.3 ± 4.6% body fat volunteered to participate in this study. During the first visit (T1 subjects reported to the laboratory in a euhydrated state to provide a baseline (BL blood draw and perform a maximal exercise test. In the four subsequent randomly ordered trials, subjects dehydrated to -2.5% of their baseline body mass. For T2, subjects achieved their goal weight and were not rehydrated. During T3 - T5, subjects reached their goal weight and then rehydrated to 1.5% of their baseline body mass by drinking either water (T3 or two different doses (T4 and T5 of the AG supplement (0.05 g·kg-1 and 0.2 g·kg-1, respectively. Subjects then exercised at a workload that elicited 75% of their VO2 max on a cycle ergometer. During T2 - T5 blood draws occurred once goal body mass was achieved (DHY, immediately prior to the exercise stress (RHY, and immediately following the exercise protocol (IP. Resting 24 hour (24P blood samples were also obtained. Blood samples were analyzed for glutamine, potassium, sodium, aldosterone, arginine vasopressin (AVP, C-reactive protein (CRP, interleukin-6 (IL-6, malondialdehyde (MDA, testosterone, cortisol, ACTH, growth hormone and creatine kinase. Statistical evaluation of performance, hormonal and biochemical changes was accomplished using a repeated measures analysis of variance. Results Glutamine concentrations for T5 were significantly higher at RHY and IP than T2 - T4. When examining performance changes (difference between T2 - T5 and T1, significantly greater times to exhaustion occurred during T4 (130.2 ± 340.2 sec and T5 (157.4 �

Glutamine synthetase gene knockout-human embryonic kidney 293E cells for stable production of monoclonal antibodies.

Science.gov (United States)

Yu, Da Young; Lee, Sang Yoon; Lee, Gyun Min

2018-05-01

Previously, it was inferred that a high glutamine synthetase (GS) activity in human embryonic kidney (HEK) 293E cells results in elevated resistance to methionine sulfoximine (MSX) and consequently hampers GS-mediated gene amplification and selection by MSX. To overcome this MSX resistance in HEK293E cells, a GS-knockout HEK293E cell line was generated using the CRISPR/Cas9 system to target the endogenous human GS gene. The GS-knockout in the HEK293E cell line (RK8) was confirmed by Western blot analysis of GS and by observation of glutamine-dependent growth. Unlike the wild type HEK293E cells, the RK8 cells were successfully used as host cells to generate a recombinant HEK293E cell line (rHEK293E) producing a monoclonal antibody (mAb). When the RK8 cells were transfected with the GS expression vector containing the mAb gene, rHEK293E cells producing the mAb could be selected in the absence as well as in the presence of MSX. The gene copies and mRNA expression levels of the mAb in rHEK293E cells were also quantified using qRT-PCR. Taken together, the GS-knockout HEK293E cell line can be used as host cells to generate stable rHEK293E cells producing a mAb through GS-mediated gene selection in the absence as well as in the presence of MSX. © 2018 Wiley Periodicals, Inc.

In Vivo PET Assay of Tumor Glutamine Flux and Metabolism: In-Human Trial of 18F-(2S,4R)-4-Fluoroglutamine.

Science.gov (United States)

Dunphy, Mark P S; Harding, James J; Venneti, Sriram; Zhang, Hanwen; Burnazi, Eva M; Bromberg, Jacqueline; Omuro, Antonio M; Hsieh, James J; Mellinghoff, Ingo K; Staton, Kevin; Pressl, Christina; Beattie, Bradley J; Zanzonico, Pat B; Gerecitano, John F; Kelsen, David P; Weber, Wolfgang; Lyashchenko, Serge K; Kung, Hank F; Lewis, Jason S

2018-05-01

Purpose To assess the clinical safety, pharmacokinetics, and tumor imaging characteristics of fluorine 18-(2S,4R)-4-fluoroglutamine (FGln), a glutamine analog radiologic imaging agent. Materials and Methods This study was approved by the institutional review board and conducted under a U.S. Food and Drug Administration-approved Investigational New Drug application in accordance with the Helsinki Declaration and the Health Insurance Portability and Accountability Act. All patients provided written informed consent. Between January 2013 and October 2016, 25 adult patients with cancer received an intravenous bolus of FGln tracer (mean, 244 MBq ± 118, <100 μg) followed by positron emission tomography (PET) and blood radioassays. Patient data were summarized with descriptive statistics. FGln biodistribution and plasma amino acid levels in nonfasting patients (n = 13) were compared with those from patients who fasted at least 8 hours before injection (n = 12) by using nonparametric one-way analysis of variance with Bonferroni correction. Tumor FGln avidity versus fluorodeoxyglucose (FDG) avidity in patients with paired PET scans (n = 15) was evaluated with the Fisher exact test. P < .05 was considered indicative of a statistically significant difference. Results FGln PET depicted tumors of different cancer types (breast, pancreas, renal, neuroendocrine, lung, colon, lymphoma, bile duct, or glioma) in 17 of the 25 patients, predominantly clinically aggressive tumors with genetic mutations implicated in abnormal glutamine metabolism. Acute fasting had no significant effect on FGln biodistribution and plasma amino acid levels. FGln-avid tumors were uniformly FDG-avid but not vice versa (P = .07). Patients experienced no adverse effects. Conclusion Preliminary human FGln PET trial results provide clinical validation of abnormal glutamine metabolism as a potential tumor biomarker for targeted radiotracer imaging in several different cancer types. © RSNA, 2018 Online

A single amino-acid substitution toggles chloride dependence of the alpha-amylase paralog amyrel in Drosophila melanogaster and Drosophila virilis species.

Science.gov (United States)

Claisse, Gaëlle; Feller, Georges; Bonneau, Magalie; Da Lage, Jean-Luc

2016-08-01

In animals, most α-amylases are chloride-dependent enzymes. A chloride ion is required for allosteric activation and is coordinated by one asparagine and two arginine side chains. Whereas the asparagine and one arginine are strictly conserved, the main chloride binding arginine is replaced by a glutamine in some rare instances, resulting in the loss of chloride binding and activation. Amyrel is a distant paralogue of α-amylase in Diptera, which was not characterized biochemically to date. Amyrel shows both substitutions depending on the species. In Drosophila melanogaster, an arginine is present in the sequence but in Drosophila virilis, a glutamine occurs at this position. We have investigated basic enzymological parameters and the dependence to chloride of Amyrel of both species, produced in yeast, and in mutants substituting arginine to glutamine or glutamine to arginine. We found that the amylolytic activity of Amyrel is about thirty times weaker than the classical Drosophila α-amylase, and that the substitution of the arginine by a glutamine in D. melanogaster suppressed the chloride-dependence but was detrimental to activity. In contrast, changing the glutamine into an arginine rendered D. virilis Amyrel chloride-dependent, and interestingly, significantly increased its catalytic efficiency. These results show that the chloride ion is not mandatory for Amyrel but stimulates the reaction rate. The possible phylogenetic origin of the arginine/glutamine substitution is also discussed. Copyright © 2016 Elsevier Ltd. All rights reserved.

The Populus superoxide dismutase gene family and its responses to drought stress in transgenic poplar overexpressing a pine cytosolic glutamine synthetase (GS1a.

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Juan Jesús Molina-Rueda

Full Text Available BACKGROUND: Glutamine synthetase (GS plays a central role in plant nitrogen assimilation, a process intimately linked to soil water availability. We previously showed that hybrid poplar (Populus tremula X alba, INRA 717-1B4 expressing ectopically a pine cytosolic glutamine synthetase gene (GS1a display enhanced tolerance to drought. Preliminary transcriptome profiling revealed that during drought, members of the superoxide dismutase (SOD family were reciprocally regulated in GS poplar when compared with the wild-type control, in all tissues examined. SOD was the only gene family found to exhibit such patterns. RESULTS: In silico analysis of the Populus genome identified 12 SOD genes and two genes encoding copper chaperones for SOD (CCSs. The poplar SODs form three phylogenetic clusters in accordance with their distinct metal co-factor requirements and gene structure. Nearly all poplar SODs and CCSs are present in duplicate derived from whole genome duplication, in sharp contrast to their predominantly single-copy Arabidopsis orthologs. Drought stress triggered plant-wide down-regulation of the plastidic copper SODs (CSDs, with concomitant up-regulation of plastidic iron SODs (FSDs in GS poplar relative to the wild type; this was confirmed at the activity level. We also found evidence for coordinated down-regulation of other copper proteins, including plastidic CCSs and polyphenol oxidases, in GS poplar under drought conditions. CONCLUSIONS: Both gene duplication and expression divergence have contributed to the expansion and transcriptional diversity of the Populus SOD/CCS families. Coordinated down-regulation of major copper proteins in drought-tolerant GS poplars supports the copper cofactor economy model where copper supply is preferentially allocated for plastocyanins to sustain photosynthesis during drought. Our results also extend previous findings on the compensatory regulation between chloroplastic CSDs and FSDs, and suggest that this

Alterations in Cerebral Cortical Glucose and Glutamine Metabolism Precedes Amyloid Plaques in the APPswe/PSEN1dE9 Mouse Model of Alzheimer's Disease

DEFF Research Database (Denmark)

Andersen, Jens V; Christensen, Sofie K; Aldana, Blanca I

2017-01-01

slices of APPswe/PSEN1dE9 mice incubated in media containing [U-(13)C]glucose. No changes in glial [1,2-(13)C]acetate metabolism were observed. Cerebral cortical slices from APPswe/PSEN1dE9 mice exhibited a reduced capacity for uptake and oxidative metabolism of glutamine. Furthermore, the ATP synthesis......Alterations in brain energy metabolism have been suggested to be of fundamental importance for the development of Alzheimer's disease (AD). However, specific changes in brain energetics in the early stages of AD are poorly known. The aim of this study was to investigate cerebral energy metabolism...... in the APPswe/PSEN1dE9 mouse prior to amyloid plaque formation. Acutely isolated cerebral cortical and hippocampal slices of 3-month-old APPswe/PSEN1dE9 and wild-type control mice were incubated in media containing [U-(13)C]glucose, [1,2-(13)C]acetate or [U-(13)C]glutamine, and tissue extracts were analyzed...

Succinimide Formation from an NGR-Containing Cyclic Peptide: Computational Evidence for Catalytic Roles of Phosphate Buffer and the Arginine Side Chain

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Ryota Kirikoshi

2017-02-01

Full Text Available The Asn-Gly-Arg (NGR motif and its deamidation product isoAsp-Gly-Arg (isoDGR have recently attracted considerable attention as tumor-targeting ligands. Because an NGR-containing peptide and the corresponding isoDGR-containing peptide target different receptors, the spontaneous NGR deamidation can be used in dual targeting strategies. It is well known that the Asn deamidation proceeds via a succinimide derivative. In the present study, we computationally investigated the mechanism of succinimide formation from a cyclic peptide, c[CH2CO-NGRC]-NH2, which has recently been shown to undergo rapid deamidation in a phosphate buffer. An H2PO4− ion was explicitly included in the calculations. We employed the density functional theory using the B3LYP functional. While geometry optimizations were performed in the gas phase, hydration Gibbs energies were calculated by the SM8 (solvation model 8 continuum model. We have found a pathway leading to the five-membered ring tetrahedral intermediate in which both the H2PO4− ion and the Arg side chain act as catalyst. This intermediate, once protonated at the NH2 group on the five-membered ring, was shown to easily undergo NH3 elimination leading to the succinimide formation. This study is the first to propose a possible catalytic role for the Arg side chain in the NGR deamidation.

Controlling the prion propensity of glutamine/asparagine-rich proteins.

Science.gov (United States)

Paul, Kacy R; Ross, Eric D

2015-01-01

The yeast Saccharomyces cerevisiae can harbor a number of distinct prions. Most of the yeast prion proteins contain a glutamine/asparagine (Q/N) rich region that drives prion formation. Prion-like domains, defined as regions with high compositional similarity to yeast prion domains, are common in eukaryotic proteomes, and mutations in various human proteins containing prion-like domains have been linked to degenerative diseases, including amyotrophic lateral sclerosis. Here, we discuss a recent study in which we utilized two strategies to generate prion activity in non-prion Q/N-rich domains. First, we made targeted mutations in four non-prion Q/N-rich domains, replacing predicted prion-inhibiting amino acids with prion-promoting amino acids. All four mutants formed foci when expressed in yeast, and two acquired bona fide prion activity. Prion activity could be generated with as few as two mutations, suggesting that many non-prion Q/N-rich proteins may be just a small number of mutations from acquiring aggregation or prion activity. Second, we created tandem repeats of short prion-prone segments, and observed length-dependent prion activity. These studies demonstrate the considerable progress that has been made in understanding the sequence basis for aggregation of prion and prion-like domains, and suggest possible mechanisms by which new prion domains could evolve.

Glutamine Attenuates Acute Lung Injury Caused by Acid Aspiration

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Chih-Cheng Lai

2014-08-01

Full Text Available Inadequate ventilator settings may cause overwhelming inflammatory responses associated with ventilator-induced lung injury (VILI in patients with acute respiratory distress syndrome (ARDS. Here, we examined potential benefits of glutamine (GLN on a two-hit model for VILI after acid aspiration-induced lung injury in rats. Rats were intratracheally challenged with hydrochloric acid as a first hit to induce lung inflammation, then randomly received intravenous GLN or lactated Ringer’s solution (vehicle control thirty min before different ventilator strategies. Rats were then randomized to receive mechanical ventilation as a second hit with a high tidal volume (TV of 15 mL/kg and zero positive end-expiratory pressure (PEEP or a low TV of 6 mL/kg with PEEP of 5 cm H2O. We evaluated lung oxygenation, inflammation, mechanics, and histology. After ventilator use for 4 h, high TV resulted in greater lung injury physiologic and biologic indices. Compared with vehicle treated rats, GLN administration attenuated lung injury, with improved oxygenation and static compliance, and decreased respiratory elastance, lung edema, extended lung destruction (lung injury scores and lung histology, neutrophil recruitment in the lung, and cytokine production. Thus, GLN administration improved the physiologic and biologic profiles of this experimental model of VILI based on the two-hit theory.

Astrocytic and neuronal oxidative metabolism are coupled to the rate of glutamate-glutamine cycle in the tree shrew visual cortex.

Science.gov (United States)

Sonnay, Sarah; Poirot, Jordan; Just, Nathalie; Clerc, Anne-Catherine; Gruetter, Rolf; Rainer, Gregor; Duarte, João M N

2018-03-01

Astrocytes play an important role in glutamatergic neurotransmission, namely by clearing synaptic glutamate and converting it into glutamine that is transferred back to neurons. The rate of this glutamate-glutamine cycle (V NT ) has been proposed to couple to that of glucose utilization and of neuronal tricarboxylic acid (TCA) cycle. In this study, we tested the hypothesis that glutamatergic neurotransmission is also coupled to the TCA cycle rate in astrocytes. For that we investigated energy metabolism by means of magnetic resonance spectroscopy (MRS) in the primary visual cortex of tree shrews (Tupaia belangeri) under light isoflurane anesthesia at rest and during continuous visual stimulation. After identifying the activated cortical volume by blood oxygenation level-dependent functional magnetic resonance imaging, 1 H MRS was performed to measure stimulation-induced variations in metabolite concentrations. Relative to baseline, stimulation of cortical activity for 20 min caused a reduction of glucose concentration by -0.34 ± 0.09 µmol/g (p glucose infusion was employed to measure fluxes of energy metabolism. Stimulation of glutamatergic activity, as indicated by a 20% increase of V NT , resulted in increased TCA cycle rates in neurons by 12% ( VTCAn, p glucose oxidation and to mitochondrial metabolism in both neurons and astrocytes. © 2017 Wiley Periodicals, Inc.

The molecular basis for oat intolerance in patients with celiac disease.

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Helene Arentz-Hansen

2004-10-01

Full Text Available BACKGROUND: Celiac disease is a small intestinal inflammatory disorder characterized by malabsorption, nutrient deficiency, and a range of clinical manifestations. It is caused by an inappropriate immune response to dietary gluten and is treated with a gluten-free diet. Recent feeding studies have indicated oats to be safe for celiac disease patients, and oats are now often included in the celiac disease diet. This study aimed to investigate whether oat intolerance exists in celiac disease and to characterize the cells and processes underlying this intolerance. METHODS AND FINDINGS: We selected for study nine adults with celiac disease who had a history of oats exposure. Four of the patients had clinical symptoms on an oats-containing diet, and three of these four patients had intestinal inflammation typical of celiac disease at the time of oats exposure. We established oats-avenin-specific and -reactive intestinal T-cell lines from these three patients, as well as from two other patients who appeared to tolerate oats. The avenin-reactive T-cell lines recognized avenin peptides in the context of HLA-DQ2. These peptides have sequences rich in proline and glutamine residues closely resembling wheat gluten epitopes. Deamidation (glutamine-->glutamic acid conversion by tissue transglutaminase was involved in the avenin epitope formation. CONCLUSIONS: We conclude that some celiac disease patients have avenin-reactive mucosal T-cells that can cause mucosal inflammation. Oat intolerance may be a reason for villous atrophy and inflammation in patients with celiac disease who are eating oats but otherwise are adhering to a strict gluten-free diet. Clinical follow-up of celiac disease patients eating oats is advisable.

Blood ammonia and glutamine as predictors of hyperammonemic crises in patients with urea cycle disorder.

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Lee, Brendan; Diaz, George A; Rhead, William; Lichter-Konecki, Uta; Feigenbaum, Annette; Berry, Susan A; Le Mons, Cindy; Bartley, James A; Longo, Nicola; Nagamani, Sandesh C; Berquist, William; Gallagher, Renata; Bartholomew, Dennis; Harding, Cary O; Korson, Mark S; McCandless, Shawn E; Smith, Wendy; Cederbaum, Stephen; Wong, Derek; Merritt, J Lawrence; Schulze, Andreas; Vockley, Jerry; Vockley, Gerard; Kronn, David; Zori, Roberto; Summar, Marshall; Milikien, Douglas A; Marino, Miguel; Coakley, Dion F; Mokhtarani, Masoud; Scharschmidt, Bruce F

2015-07-01

The aim of this study was to examine predictors of ammonia exposure and hyperammonemic crises in patients with urea cycle disorders. The relationships between fasting ammonia, daily ammonia exposure, and hyperammonemic crises were analyzed in >100 patients with urea cycle disorders. Fasting ammonia correlated strongly with daily ammonia exposure (r = 0.764; P 200% (P urea cycle disorder subtype, dietary protein intake, or blood urea nitrogen. Fasting glutamine correlated weakly with daily ammonia exposure assessed as 24-hour area under the curve and was not a significant predictor of hyperammonemic crisis. Fasting ammonia correlates strongly and positively with daily ammonia exposure and with the risk and rate of hyperammonemic crises, suggesting that patients with urea cycle disorder may benefit from tight ammonia control.

Natural variation of the amino-terminal glutamine-rich domain in Drosophila argonaute2 is not associated with developmental defects.

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Daniel Hain

2010-12-01

Full Text Available The Drosophila argonaute2 (ago2 gene plays a major role in siRNA mediated RNA silencing pathways. Unlike mammalian Argonaute proteins, the Drosophila protein has an unusual amino-terminal domain made up largely of multiple copies of glutamine-rich repeats (GRRs. We report here that the ago2 locus produces an alternative transcript that encodes a putative short isoform without this amino-terminal domain. Several ago2 mutations previously reported to be null alleles only abolish expression of the long, GRR-containing isoform. Analysis of drop out (dop mutations had previously suggested that variations in GRR copy number result in defects in RNAi and embryonic development. However, we find that dop mutations genetically complement transcript-null alleles of ago2 and that ago2 alleles with variant GRR copy numbers support normal development. In addition, we show that the assembly of the central RNAi machinery, the RISC (RNA induced silencing complex, is unimpaired in embryos when GRR copy number is altered. In fact, we find that GRR copy number is highly variable in natural D. melanogaster populations as well as in laboratory strains. Finally, while many other insects share an extensive, glutamine-rich Ago2 amino-terminal domain, its primary sequence varies drastically between species. Our data indicate that GRR variation does not modulate an essential function of Ago2 and that the amino-terminal domain of Ago2 is subject to rapid evolution.

The neuropharmacology of L-theanine(N-ethyl-L-glutamine): a possible neuroprotective and cognitive enhancing agent.

Science.gov (United States)

Nathan, Pradeep J; Lu, Kristy; Gray, M; Oliver, C

2006-01-01

L-theanine (N-ethyl-L-glutamine) or theanine is a major amino acid uniquely found in green tea. L-theanine has been historically reported as a relaxing agent, prompting scientific research on its pharmacology. Animal neurochemistry studies suggest that L-theanine increases brain serotonin, dopamine, GABA levels and has micromolar affinities for AMPA, Kainate and NMDA receptors. In addition has been shown to exert neuroprotective effects in animal models possibly through its antagonistic effects on group 1 metabotrophic glutamate receptors. Behavioural studies in animals suggest improvement in learning and memory. Overall, L-theanine displays a neuropharmacology suggestive of a possible neuroprotective and cognitive enhancing agent and warrants further investigation in animals and humans.

Physicochemical and microbiological changes in irradiated fresh pork loins

International Nuclear Information System (INIS)

Dogbevi, M.K.; Vachon, C.; Lacroix, M.

1999-01-01

The effect of γ-irradiation on the physicochemical and microbiological properties of fresh pork was studied. Radiation treatments were carried out under air on fresh pork loins at doses of 2, 4 and 8 kGy and the loins were evaluated for deamidation, solubility, sulphydryl content and surface hydrophobicity. Deamidation was significantly (p⩽0.05) affected by the treatment with 98% deamidation at a dose of 8 kGy. No significant changes (p>0.05) were noted in sulphydryl content under the same conditions. The increase in deamidation resulted in a decrease in hydrophobicity and an increase in protein solubility. γ-irradiation also reduced the number of microorganisms in the meat. Mesophiles were more resistant to the irradiation treatment than psychrotrophs and Pseudomonas. All irradiated pork samples (1 or 3 kGy) had a bacterial count lower that 10(7) CFU/g after 15 days of storage. A minimal dose of 1 kGy was sufficient to increase the shelf life of fresh pork loins although variations in initial pork contamination was found to be the determining factor accounting for the effectiveness of the treatment

Immunonutrition - the influence of early postoperative glutamine supplementation in enteral/parenteral nutrition on immune response, wound healing and length of hospital stay in multiple trauma patients and patients after extensive surgery.

Science.gov (United States)

Lorenz, Kai J; Schallert, Reiner; Daniel, Volker

2015-01-01

In the postoperative phase, the prognosis of multiple trauma patients with severe brain injuries as well as of patients with extensive head and neck surgery mainly depends on protein metabolism and the prevention of septic complications. Wound healing problems can also result in markedly longer stays in the intensive care unit and general wards. As a result, the immunostimulation of patients in the postoperative phase is expected to improve their immunological and overall health. A study involving 15 patients with extensive ENT tumour surgery and 7 multiple-trauma patients investigated the effect of enteral glutamine supplementation on immune induction, wound healing and length of hospital stay. Half of the patients received a glutamine-supplemented diet. The control group received an isocaloric, isonitrogenous diet. In summary, we found that total lymphocyte counts, the percentage of activated CD4+DR+ T helper lymphocytes, the in-vitro response of lymphocytes to mitogens, as well as IL-2 plasma levels normalised faster in patients who received glutamine-supplemented diets than in patients who received isocaloric, isonitrogenous diets and that these parameters were even above normal by the end of the second postoperative week. We believe that providing critically ill patients with a demand-oriented immunostimulating diet is fully justified as it reduces septic complications, accelerates wound healing, and shortens the length of ICU (intensive care unit) and general ward stays.

SU-F-I-68: Longitudinal Neurochemical Changes On Rat Prefrontal Cortex of Single Prolonged Stress Model by Using Proton Magnetic Resonance Spectroscopy at 9.4T

International Nuclear Information System (INIS)

Lim, S-I; Yoo, C-H; Song, K-H; Choe, B-Y; Woo, D-C

2016-01-01

Purpose: Single prolonged stress (SPS) is an animal model of posttraumatic stress disorder (PTSD). However, it has not been known how PTSD develops from the first exposure to traumatic events and neurochemical differences between acute/single stress and PTSD-triggering stress. Therefore, the object of this study is to determine time-dependent neurochemical changes in prefrontal cortex (PFC) of rats using in vivo proton magnetic resonance spectroscopy (1H-MRS). Methods: Male Sprague-Dawley rats (n=14; body weight=200–220g) were used. The SPS protocol was used in this study. Rats were restrained for 2h and then immediately forced to swim for 20min in water (20–24 Celsius). After a 15-min recuperation period, rats were exposed to ether (using a desiccator) until general anesthesia occurred (<5min). In vivo proton MRS was performed 30min before the SPS (Base), approximately 10min after the SPS (D+0), 3 (D+3) and 7 (D+7) days after SPS to investigate time-dependent changes on metabolites levels in the PFC. Acquisition of in vivo MRS spectra and MRI was conducted at the four time points using 9.4 T Agilent Scanner. Concentration of metabolites was quantified by LCModel. Results: Statistical significance was analyzed using one-way ANOVA with post hoc Tukey HSD tests to assess the metabolite changes in the PFC. The SPS resulted in significant stress-induced differences for 7 days in glutamine (F(3,52)=6.750, P=0.001), choline-containing compounds (F(3,52)=16.442, P=0.000), glutamine/glutamate concentrations (F(3,52)=7.352, P=0.000). Conclusion: PTSD in human is associated with decreased neuronal activity in the PFC. In this study, SPS altered total choline, glutamine levels but not NAA levels in the PFC of the rats. Therefore, for the three stressors and quiescent period of seven days, SPS attenuated excitatory tone and membrane turnover but did not affect neural integrity in the PFC.

SU-F-I-68: Longitudinal Neurochemical Changes On Rat Prefrontal Cortex of Single Prolonged Stress Model by Using Proton Magnetic Resonance Spectroscopy at 9.4T

Energy Technology Data Exchange (ETDEWEB)

Lim, S-I; Yoo, C-H [Department of Biomedical Engineering, and Research Institute of Biomedical Engineering, The Catholic University of Korea College of Medicine, Seoul, Seoul (Korea, Republic of); Asan Institute for Life Sciences, Asan Medical Center, Seoul, Seoul (Korea, Republic of); Song, K-H; Choe, B-Y [Department of Biomedical Engineering, and Research Institute of Biomedical Engineering, The Catholic University of Korea College of Medicine, Seoul, Seoul (Korea, Republic of); Woo, D-C [Asan Institute for Life Sciences, Asan Medical Center, Seoul, Seoul (Korea, Republic of)

2016-06-15

Purpose: Single prolonged stress (SPS) is an animal model of posttraumatic stress disorder (PTSD). However, it has not been known how PTSD develops from the first exposure to traumatic events and neurochemical differences between acute/single stress and PTSD-triggering stress. Therefore, the object of this study is to determine time-dependent neurochemical changes in prefrontal cortex (PFC) of rats using in vivo proton magnetic resonance spectroscopy (1H-MRS). Methods: Male Sprague-Dawley rats (n=14; body weight=200–220g) were used. The SPS protocol was used in this study. Rats were restrained for 2h and then immediately forced to swim for 20min in water (20–24 Celsius). After a 15-min recuperation period, rats were exposed to ether (using a desiccator) until general anesthesia occurred (<5min). In vivo proton MRS was performed 30min before the SPS (Base), approximately 10min after the SPS (D+0), 3 (D+3) and 7 (D+7) days after SPS to investigate time-dependent changes on metabolites levels in the PFC. Acquisition of in vivo MRS spectra and MRI was conducted at the four time points using 9.4 T Agilent Scanner. Concentration of metabolites was quantified by LCModel. Results: Statistical significance was analyzed using one-way ANOVA with post hoc Tukey HSD tests to assess the metabolite changes in the PFC. The SPS resulted in significant stress-induced differences for 7 days in glutamine (F(3,52)=6.750, P=0.001), choline-containing compounds (F(3,52)=16.442, P=0.000), glutamine/glutamate concentrations (F(3,52)=7.352, P=0.000). Conclusion: PTSD in human is associated with decreased neuronal activity in the PFC. In this study, SPS altered total choline, glutamine levels but not NAA levels in the PFC of the rats. Therefore, for the three stressors and quiescent period of seven days, SPS attenuated excitatory tone and membrane turnover but did not affect neural integrity in the PFC.

Initiation of Swarming Motility by Proteus mirabilis Occurs in Response to Specific Cues Present in Urine and Requires Excess l-Glutamine

Science.gov (United States)

Armbruster, Chelsie E.; Hodges, Steven A.

2013-01-01

Proteus mirabilis, a leading cause of catheter-associated urinary tract infection (CaUTI), differentiates into swarm cells that migrate across catheter surfaces and medium solidified with 1.5% agar. While many genes and nutrient requirements involved in the swarming process have been identified, few studies have addressed the signals that promote initiation of swarming following initial contact with a surface. In this study, we show that P. mirabilis CaUTI isolates initiate swarming in response to specific nutrients and environmental cues. Thirty-three compounds, including amino acids, polyamines, fatty acids, and tricarboxylic acid (TCA) cycle intermediates, were tested for the ability to promote swarming when added to normally nonpermissive media. l-Arginine, l-glutamine, dl-histidine, malate, and dl-ornithine promoted swarming on several types of media without enhancing swimming motility or growth rate. Testing of isogenic mutants revealed that swarming in response to the cues required putrescine biosynthesis and pathways involved in amino acid metabolism. Furthermore, excess glutamine was found to be a strict requirement for swarming on normal swarm agar in addition to being a swarming cue under normally nonpermissive conditions. We thus conclude that initiation of swarming occurs in response to specific cues and that manipulating concentrations of key nutrient cues can signal whether or not a particular environment is permissive for swarming. PMID:23316040

Reduced parietooccipital white matter glutamine measured by proton magnetic resonance spectroscopy in treated graves' disease patients

DEFF Research Database (Denmark)

Danielsen, Else Rubæk; Elberling, T.V.; Rasmussen, Åse Krogh

2008-01-01

CONTEXT: Graves' disease is an autoimmune disease of the thyroid gland. Patients often have affective and cognitive complaints, whether these disappear after treatment remains disputed. OBJECTIVE: Our objective was to evaluate cerebral biochemistry in acute and treated Graves' disease. DESIGN: We...... conducted a prospective study, investigating volunteers once and patients before and 1 yr after treatment. SETTING: The study was performed at a radiology department, a memory disorder clinic, and two endocrinology clinics. PATIENTS AND OTHER PARTICIPANTS: Of 53 consecutively referred, newly diagnosed...... and a battery of biochemical, affective, and cognitive tests were used. RESULTS: Previously reported findings of reduced choline and myo-inositol in acute Graves' disease were confirmed and reversibility was demonstrated. Parieto-occipital white matter glutamine was and remained significantly reduced (P

Possible links between intestinal permeablity and food processing: a potential therapeutic niche for glutamine

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Jean Robert Rapin

2010-01-01

Full Text Available Increased intestinal permeability is a likely cause of various pathologies, such as allergies and metabolic or even cardiovascular disturbances. Intestinal permeability is found in many severe clinical situations and in common disorders such as irritable bowel syndrome. In these conditions, substances that are normally unable to cross the epithelial barrier gain access to the systemic circulation. To illustrate the potential harmfulness of leaky gut, we present an argument based on examples linked to protein or lipid glycation induced by modern food processing. Increased intestinal permeability should be largely improved by dietary addition of compounds, such as glutamine or curcumin, which both have the mechanistic potential to inhibit the inflammation and oxidative stress linked to tight junction opening. This brief review aims to increase physician awareness of this common, albeit largely unrecognized, pathology, which may be easily prevented or improved by means of simple nutritional changes.

Possible Links between Intestinal Permeablity and Food Processing: A Potential Therapeutic Niche for Glutamine

Science.gov (United States)

Rapin, Jean Robert; Wiernsperger, Nicolas

2010-01-01

Increased intestinal permeability is a likely cause of various pathologies, such as allergies and metabolic or even cardiovascular disturbances. Intestinal permeability is found in many severe clinical situations and in common disorders such as irritable bowel syndrome. In these conditions, substances that are normally unable to cross the epithelial barrier gain access to the systemic circulation. To illustrate the potential harmfulness of leaky gut, we present an argument based on examples linked to protein or lipid glycation induced by modern food processing. Increased intestinal permeability should be largely improved by dietary addition of compounds, such as glutamine or curcumin, which both have the mechanistic potential to inhibit the inflammation and oxidative stress linked to tight junction opening. This brief review aims to increase physician awareness of this common, albeit largely unrecognized, pathology, which may be easily prevented or improved by means of simple nutritional changes. PMID:20613941

Neurotransmitter synthesis from CNS glutamine for central control of breathing

International Nuclear Information System (INIS)

Hoop, B.; Systrom, D.; Chiang, C.H.; Shih, V.E.; Kazemi, H.

1986-01-01

The maximum rate at which CNS glutamine (GLN) derived from glutamate (GLU) can be sequestered for synthesis of neurotransmitter GLU and/or γ-aminobutyric acid (GABA) has been determined in pentobarbital-anesthetized dogs. A total of 57 animals were studied under normal, hypoxic (Pa/sub O2/ greater than or equal to 20 mmHg), or hypercapnic (Pa/sub CO2/ less than or equal to 71 mm Hg) conditions. Thirteen of these were bilaterally vagotomized and carotid body denervated and studied only under normoxic or hypoxic conditions. In 5 animals cerebrospinal fluid GLN transfer rate constant k was measured using 13 N-ammonia tracer. Measured cerebral cortical (CC) and medullary (MED) GLN concentrations c are found to vary with GLU metabolic rate r according to c-C/sub m/r/(r+R), where r, the product of k and corresponding tissue GLU concentration, is assumed equal to the maximum GLN metabolic rate via pathways other than for neurotransmitter synthesis. The constants C/sub m/ and R are the predicted maximum GLN concentration and its maximum rate of sequestration for neurotransmitter synthesis, respectively. For both CNS tissue types in all animals, C/sub m/ = 20.9 +- 7.4 (SD) mmoles/kg wet wt(mM) and R = 6.2 +- 2.3 mM/min. These values are consistent with results obtained in anesthetized rats

Haplotype analysis of the genes encoding glutamine synthetase plastic isoforms and their association with nitrogen-use- and yield-related traits in bread wheat.

Science.gov (United States)

Li, Xin-Peng; Zhao, Xue-Qiang; He, Xue; Zhao, Guang-Yao; Li, Bin; Liu, Dong-Cheng; Zhang, Ai-Min; Zhang, Xue-Yong; Tong, Yi-Ping; Li, Zhen-Sheng

2011-01-01

Glutamine synthetase (GS) plays a key role in the growth, nitrogen (N) use and yield potential of cereal crops. Investigating the haplotype variation of GS genes and its association with agronomic traits may provide useful information for improving wheat N-use efficiency and yield. We isolated the promoter and coding region sequences of the plastic glutamine synthetase isoform (GS2) genes located on chromosomes 2A, 2B and 2D in bread wheat. By analyzing nucleotide sequence variations of the coding region, two, six and two haplotypes were distinguished for TaGS2-A1 (a and b), TaGS2-B1 (a-f) and TaGS2-D1 (a and b), respectively. By analyzing the frequency data of different haplotypes and their association with N use and agronomic traits, four major and favorable TaGS2 haplotypes (A1b, B1a, B1b, D1a) were revealed. These favorable haplotypes may confer better seedling growth, better agronomic performance, and improved N uptake during vegetative growth or grain N concentration. Our data suggest that certain TaGS2 haplotypes may be valuable in breeding wheat varieties with improved agronomic performance and N-use efficiency. © The Authors (2010). Journal compilation © New Phytologist Trust (2010).

[Impact of glutamine, eicosapntemacnioc acid, branched-chain amino acid supplements on nutritional status and treatment compliance of esophageal cancer patients on concurrent chemoradiotherapy and gastric cancer patients on chemotherapy].

Science.gov (United States)

Cong, Minghua; Song, Chenxin; Zou, Baohua; Deng, Yingbing; Li, Shuluan; Liu, Xuehui; Liu, Weiwei; Liu, Jinying; Yu, Lei; Xu, Binghe

2015-03-17

To explore the effects of glutamine, eicosapntemacnioc acid (EPA) and branched-chain amino acids supplements in esophageal cancer patients on concurrent chemoradiotherapy and gastric cancer patients on chemotherapy. From April 2013 to April 2014, a total of 104 esophageal and gastric carcinoma patients on chemotherapy or concurrent chemoradiotherapy were recruited and randomly divided into experimental and control groups. Both groups received dietary counseling and routine nutritional supports while only experimental group received supplements of glutamine (20 g/d), EPA (3.3 g/d) and branched-chain amino acids (8 g/d). And body compositions, blood indicators, incidence of complications and completion rates of therapy were compared between two groups. After treatment, free fat mass and muscle weight increased significantly in experiment group while decreased in control group (P nutrition status, decrease the complications and improve compliance for esophageal cancer patients on concurrent chemo-radiotherapy and gastric cancer patients on postoperative adjuvant chemotherapy.

Age-dependent decrease in glutamine synthetase expression in the hippocampal astroglia of the triple transgenic Alzheimer's disease mouse model: Mechanism for deficient glutamatergic transmission?

Czech Academy of Sciences Publication Activity Database

Olabarria, M.; Noristani, H. N.; Verkhratsky, Alexei; Rodríguez Arellano, Jose Julio

2011-01-01

Roč. 6, č. 1 (2011), s. 55-63 ISSN 1750-1326 R&D Projects: GA ČR GA309/09/1696; GA ČR(CZ) GAP304/11/0184; GA ČR GA305/08/1384; GA ČR GA309/08/1381 Institutional research plan: CEZ:AV0Z50390703 Keywords : astroglia * glutamine synthetase * Alzheimer ?'?s disease Subject RIV: FH - Neurology Impact factor: 4.278, year: 2011

Inhibitory plant serpins with a sequence of three glutamine residues in the reactive center

DEFF Research Database (Denmark)

Hejgaard, Jørn

2005-01-01

Serpins appear to be ubiquitous in eukaryotes, except fungi, and are also present in some bacteria, archaea and viruses. Inhibitory serpins with a glutamine as the reactive-center P1 residue have been identified exclusively in a few plant species. Unique serpins with a reactive center sequence...... of three Gln residues at P3-P1 or P2-P1' were isolated from barley and wheat grain, respectively. Barley BSZ3 was an irreversible inhibitor of chymotrypsin, with a second-order association rate constant for complex formation k(a)' of the order of 10(4) M-1 s(-1) ; however, only a minor fraction...... of the serpin molecules reacted with chymotrypsin, with the majority insensitive to cleavage in the reactive center loop. Wheat WSZ3 was cleaved specifically at P8 Thr and was not an inhibitor of chymotrypsin. These reactive-center loops may have evolved conformations that are optimal as inhibitory baits...

The transcriptional activator NtrC controls the expression and activity of glutamine synthetase in Herbaspirillum seropedicae.

Science.gov (United States)

Persuhn, D C; Souza, E M; Steffens, M B; Pedrosa, F O; Yates, M G; Rigo, L U

2000-11-15

The role of the Ntr system in Herbaspirillum seropedicae was determined via ntrB and ntrC mutants. Three phenotypes were identified in these mutants: Nif(-), deficiency in growth using nitrate, and low glutamine synthetase (GS) activity. All phenotypes were restored by the plasmid pKRT1 containing the intact glnA, ntrB and ntrC genes of H. seropedicae. The promoter region of glnA was subcloned into a beta-galactosidase fusion vector and the results suggested that NtrC positively regulates the glnA promoter in response to low nitrogen. The H. seropedicae ntrC and ntrB mutant strains showed a deficiency of adenylylation/deadenylylation of GS, indicating that NtrC and NtrB are involved in both transcription and activity control of GS in this organism.

Metabolic Alterations Caused by KRAS Mutations in Colorectal Cancer Contribute to Cell Adaptation to Glutamine Depletion by Upregulation of Asparagine Synthetase

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Kosuke Toda

2016-11-01

Full Text Available A number of clinical trials have shown that KRAS mutations of colorectal cancer (CRC can predict a lack of responses to anti-epidermal growth factor receptor–based therapy. Recently, there have been several studies to elucidate metabolism reprogramming in cancer. However, it remains to be investigated how mutated KRAS can coordinate the metabolic shift to sustain CRC tumor growth. In this study, we found that KRAS mutation in CRC caused alteration in amino acid metabolism. KRAS mutation causes a marked decrease in aspartate level and an increase in asparagine level in CRC. Using several human CRC cell lines and clinical specimens of primary CRC, we demonstrated that the expression of asparagine synthetase (ASNS, an enzyme that synthesizes asparagine from aspartate, was upregulated by mutated KRAS and that ASNS expression was induced by KRAS-activated signaling pathway, in particular PI3K-AKT-mTOR pathway. Importantly, we demonstrated that KRAS-mutant CRC cells could become adaptive to glutamine depletion through asparagine biosynthesis by ASNS and that asparagine addition could rescue the inhibited growth and viability of cells grown under the glutamine-free condition in vitro. Notably, a pronounced growth suppression of KRAS-mutant CRC was observed upon ASNS knockdown in vivo. Furthermore, combination of L-asparaginase plus rapamycin markedly suppressed the growth of KRAS-mutant CRC xenografts in vivo, whereas either L-asparaginase or rapamycin alone was not effective. These results indicate ASNS might be a novel therapeutic target against CRCs with mutated KRAS.

Immunonutrition – the influence of early postoperative glutamine supplementation in enteral/parenteral nutrition on immune response, wound healing and length of hospital stay in multiple trauma patients and patients after extensive surgery

Directory of Open Access Journals (Sweden)

Lorenz, Kai J.

2015-12-01

Full Text Available Introduction: In the postoperative phase, the prognosis of multiple trauma patients with severe brain injuries as well as of patients with extensive head and neck surgery mainly depends on protein metabolism and the prevention of septic complications. Wound healing problems can also result in markedly longer stays in the intensive care unit and general wards. As a result, the immunostimulation of patients in the postoperative phase is expected to improve their immunological and overall health. Patients and methods: A study involving 15 patients with extensive ENT tumour surgery and 7 multiple-trauma patients investigated the effect of enteral glutamine supplementation on immune induction, wound healing and length of hospital stay. Half of the patients received a glutamine-supplemented diet. The control group received an isocaloric, isonitrogenous diet.Results: In summary, we found that total lymphocyte counts, the percentage of activated CD4+DR+ T helper lymphocytes, the in-vitro response of lymphocytes to mitogens, as well as IL-2 plasma levels normalised faster in patients who received glutamine-supplemented diets than in patients who received isocaloric, isonitrogenous diets and that these parameters were even above normal by the end of the second postoperative week.Summary: We believe that providing critically ill patients with a demand-oriented immunostimulating diet is fully justified as it reduces septic complications, accelerates wound healing, and shortens the length of ICU (intensive care unit and general ward stays.

The association between glutamine repeats in the androgen receptor gene and personality traits in dromedary camel (Camelus dromedarius).

Science.gov (United States)

Ramadan, Sherif; Nowier, Amira M; Hori, Yusuke; Inoue-Murayama, Miho

2018-01-01

Temperament traits such as fearfulness are important as they define an animal's responses to its environment and handling. The increasing automation of daily tasks and growing population limits contact between camels and humans. Such limitations contribute to fear of humans and changes in physical environment. Monoamine oxidase A (MAOA) and androgen receptor (AR) genes are important candidates associated with mammal personality. In our analysis, MAOA exon 15 showed no polymorphism but a novel polymorphism was seen in the camel AR exon 1; 16, 17, 18, and 19 glutamine repeats were detected. We genotyped 138 camels belonging to four Egyptian breeds: Maghrabi (n = 90), Sudani (n = 15), Somali (n = 23), and Baladi (n = 10) for AR. Out of the 90 genotyped Maghrabi camels, we evaluated responses of 33 and 32 mature females to a novel object and exposure to an unfamiliar person, respectively. AR gene showed a significant association based on the principal component (PC) score, which indicated the fear of human touch, and the PC score indicates fear during interaction with novel objects. Individuals carrying a shorter genotype in homozygote (S/S) were found to be more fearful. Furthermore, we found that Sudani and Somali breeds had a higher frequency of shorter genotype (S/S), which was associated with increased fearfulness. These findings reflect the behavioral tendency and consequently, affect the use of this breed. This is the first report showing the role of AR glutamine repeats influencing a behavioral trait in dromedary camels and leading to inter-breed differences. Fear-related traits reported here are important because camels cope with various types of stresses and fear, resulting from the demands of intensive production systems and racing events. However, further studies, employing functional genomics and linkage analysis are necessary for confirming the relationship between fearfulness and genetic variation.

The association between glutamine repeats in the androgen receptor gene and personality traits in dromedary camel (Camelus dromedarius.

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Sherif Ramadan

Full Text Available Temperament traits such as fearfulness are important as they define an animal's responses to its environment and handling. The increasing automation of daily tasks and growing population limits contact between camels and humans. Such limitations contribute to fear of humans and changes in physical environment. Monoamine oxidase A (MAOA and androgen receptor (AR genes are important candidates associated with mammal personality. In our analysis, MAOA exon 15 showed no polymorphism but a novel polymorphism was seen in the camel AR exon 1; 16, 17, 18, and 19 glutamine repeats were detected. We genotyped 138 camels belonging to four Egyptian breeds: Maghrabi (n = 90, Sudani (n = 15, Somali (n = 23, and Baladi (n = 10 for AR. Out of the 90 genotyped Maghrabi camels, we evaluated responses of 33 and 32 mature females to a novel object and exposure to an unfamiliar person, respectively. AR gene showed a significant association based on the principal component (PC score, which indicated the fear of human touch, and the PC score indicates fear during interaction with novel objects. Individuals carrying a shorter genotype in homozygote (S/S were found to be more fearful. Furthermore, we found that Sudani and Somali breeds had a higher frequency of shorter genotype (S/S, which was associated with increased fearfulness. These findings reflect the behavioral tendency and consequently, affect the use of this breed. This is the first report showing the role of AR glutamine repeats influencing a behavioral trait in dromedary camels and leading to inter-breed differences. Fear-related traits reported here are important because camels cope with various types of stresses and fear, resulting from the demands of intensive production systems and racing events. However, further studies, employing functional genomics and linkage analysis are necessary for confirming the relationship between fearfulness and genetic variation.

A diet containing whey protein, glutamine, and TGFbeta modulates gut protein metabolism during chemotherapy-induced mucositis in rats.

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Boukhettala, Nabile; Ibrahim, Ayman; Claeyssens, Sophie; Faure, Magali; Le Pessot, Florence; Vuichoud, Jacques; Lavoinne, Alain; Breuillé, Denis; Déchelotte, Pierre; Coëffier, Moïse

2010-08-01

Mucositis, a common side effect of chemotherapy, is characterized by compromised digestive function, barrier integrity and immune competence. Our aim was to evaluate the impact of a specifically designed diet Clinutren Protect (CP), which contains whey proteins, TGFbeta-rich casein, and free glutamine, on mucositis in rats. Mucositis was induced by three consecutive injections (day 0, day 1, day 2) of methotrexate (2.5 mg/kg). Rats had free access to CP or placebo diets from days -7 to 9. In the placebo diet, whey proteins and TGFbeta-rich casein were replaced by TGFbeta-free casein and glutamine by alanine. Intestinal parameters were assessed at day 3 and 9. Values, expressed as mean +/- SEM, were compared using two-way ANOVA. At day 3, villus height was markedly decreased in the placebo (296 +/- 11 microm) and CP groups (360 +/- 10 microm) compared with controls (464 +/- 27 microm), but more markedly in the placebo as compared to CP group. The intestinal damage score was also reduced in the CP compared with the placebo group. Glutathione content increased in the CP compared with the placebo group (2.2 +/- 0.2 vs. 1.7 +/- 0.2 micromol/g tissue). Gut protein metabolism was more affected in the placebo than in the CP group. The fractional synthesis rate was decreased in the placebo group (93.8 +/- 4.9%/day) compared with controls (121.5 +/- 12.1, P < 0.05), but not in the CP group (106.0 +/- 13.1). In addition, at day 9, rats exhibited improved body weight and food intake recovery in the CP compared to the placebo group. Clinutren Protect feeding reduces intestinal injury in the acute phase of methotrexate-induced mucositis in rats and improves recovery.

The glutamate-glutamine(GABA cycle: importance of late postnatal development and potential reciprocal interactions between biosynthesis and degradation

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Leif eHertz

2013-05-01

Full Text Available The gold standard for studies of glutamate-glutamine(GABA cycling and its connections to brain biosynthesis from glucose of glutamate and GABA and their subsequent metabolism are the elegant in vivo studies by 13C magnetic resonance spectroscopy (NMR, showing the large fluxes in the cycle. However, simpler experiments in intact brain tissue (e.g. immunohistochemistry, brain slices, cultured brain cells and mitochondria have also made important contributions to the understanding of details, mechanisms and functional consequences of glutamate/GABA biosynthesis and degradation. The purpose of this review is to attempt to integrate evidence from different sources regarding i the enzyme(s responsible for the initial conversion of -ketoglutarate to glutamate; ii the possibility that especially glutamate oxidation is essentially confined to astrocytes; and iii the ontogenetically very late onset and maturation of glutamine-glutamate(GABA cycle function. Pathway models based on the functional importance of aspartate for glutamate synthesis suggest the possibility of interacting pathways for biosynthesis and degradation of glutamate and GABA and the use of transamination as the default mechanism for initiation of glutamate oxidation. The late development and maturation are related to the late cortical gliogenesis and convert brain cortical function from being purely neuronal to becoming neuronal-astrocytic. This conversion is associated with huge increases in energy demand and production, and the character of potentially incurred gains of function are discussed. These may include alterations in learning mechanisms, in mice indicated by lack of pairing of odor learning with aversive stimuli in newborn animals but the development of such an association 10-12 days later. The possibility is suggested that analogous maturational changes may contribute to differences in the way learning is accomplished in the newborn human brain and during later development.

Glutamine synthetase activity in solanaceous cell suspensions accumulating alkaloids or not. 13C NMR and enzymatic assay

International Nuclear Information System (INIS)

Mesnard, F.; Marty, D.; Monti, J.P.; Gillet-Manceau, F.; Fliniaux, M.A.

1999-01-01

The metabolism of labelled pyruvate followed by 13 C NMR and the measure of glutamine synthetase (GS) showed, according to previous results, a high activity of this enzyme in suspension cells of Nicotiana plumbaginifolia. This activity could derive glutamate from the alkaloid synthesizing pathways. However, a recent work showed that the rate of the GS gene transcription was inversely proportional to the Gln/Glu ratio. The measures of Gln and Glu concentrations in Nicotiana plumbaginifolia cells revealed that high GS activity correlates with the weak value of Gln/Glu ratio. Therefore, the hypothesis of GS dysfunction for the non-biosynthesis of alkaloids in N. plumbaginifolia suspension cells can be discarded. This conclusion is strengthened by the results obtained when using a GS inhibitor. (author)

CNF1-like deamidase domains: common Lego bricks among cancer-promoting immunomodulatory bacterial virulence factors.

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Ho, Mengfei; Mettouchi, Amel; Wilson, Brenda A; Lemichez, Emmanuel

2018-05-03

Alterations of the cellular proteome over time due to spontaneous or toxin-mediated enzymatic deamidation of glutamine (Gln) and asparagine (Asn) residues contribute to bacterial infection and might represent a source of aging-related diseases. Here, we put into perspective what is known about the mode of action of the CNF1 toxin from pathogenic E. coli, a paradigm of bacterial deamidases that activate Rho GTPases, to illustrate the importance of determining whether exposure to these factors are risk factors in the etiology age-related diseases, such as cancer. In particular, through in silico analysis of the distribution of the CNF1-like deamidase active site Gly-Cys-(Xaa)n-His sequence motif in bacterial genomes, we unveil the wide distribution of the super-family of CNF-like toxins and CNF-like deamidase domains among members of the enterobacteriacae and in association with a large variety of toxin delivery systems. We extent our discussion with recent findings concerning cellular systems that control activated Rac1 GTPase stability and provide protection against cancer. These findings point to the urgency for developing holistic approaches toward personalized medicine that include monitoring for asymptomatic carriage of pathogenic toxin-producing bacteria and that ultimately might lead to improved public health and increased lifespans.

Thirteen-week oral toxicity study of L-glutamine in rats.

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Tsubuku, Shoji; Hatayama, Kazuhisa; Mawatari, Kazunori; Smriga, Miro; Kimura, Takeshi

2004-01-01

L-Glutamine (Gln) is a semiessential amino acid used in enteral feeding in critically ill patients, and is contained in numerous dietary supplements available to the general public. This study evaluated toxicological effects of Gln in male and female Sprague-Dawley rats. Gln produced by Ajinomoto Co. (Tokyo, Japan) was incorporated into a standard diet at doses equal to 1.25%, 2.5%, and 5.0% (w/w), respectively. A control group of rats received only a standard diet. All diets were administered ad libitum for 13 consecutive weeks. To examine recoverability of any potential effects, the administration period was followed by a 5-week recovery period, during which only the standard diet was provided to all animals. Throughout the administration and recovery periods, no deaths were observed, and no changes in diet consumption, ophthalmologic findings, gross pathology, and histopathology were detected. Several changes in urine parameters (total protein, urine pH, and a positive incidence (+/-) of ketone bodies) were observed in the 2.5% and 5.0% groups at the end of the administration period. Minor increases were found in hematology parameters for the 5.0% group (platelet count, gamma-globulin, lactate dehydrogenase [LDH]), but all changes were within physiological range. No effects of administration were observed in the 1.25% group. The no-observed-adverse-effect level (NOAEL) for Gln was estimated at 1.25% for both genders (males 0.83 +/- 0.01 g/kg/day; females, 0.96 +/- 0.06 g/kg/day).

Improving the efficiency of CHO cell line generation using glutamine synthetase gene knockout cells.

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Fan, Lianchun; Kadura, Ibrahim; Krebs, Lara E; Hatfield, Christopher C; Shaw, Margaret M; Frye, Christopher C

2012-04-01

Although Chinese hamster ovary (CHO) cells, with their unique characteristics, have become a major workhorse for the manufacture of therapeutic recombinant proteins, one of the major challenges in CHO cell line generation (CLG) is how to efficiently identify those rare, high-producing clones among a large population of low- and non-productive clones. It is not unusual that several hundred individual clones need to be screened for the identification of a commercial clonal cell line with acceptable productivity and growth profile making the cell line appropriate for commercial application. This inefficiency makes the process of CLG both time consuming and laborious. Currently, there are two main CHO expression systems, dihydrofolate reductase (DHFR)-based methotrexate (MTX) selection and glutamine synthetase (GS)-based methionine sulfoximine (MSX) selection, that have been in wide industrial use. Since selection of recombinant cell lines in the GS-CHO system is based on the balance between the expression of the GS gene introduced by the expression plasmid and the addition of the GS inhibitor, L-MSX, the expression of GS from the endogenous GS gene in parental CHOK1SV cells will likely interfere with the selection process. To study endogenous GS expression's potential impact on selection efficiency, GS-knockout CHOK1SV cell lines were generated using the zinc finger nuclease (ZFN) technology designed to specifically target the endogenous CHO GS gene. The high efficiency (∼2%) of bi-allelic modification on the CHO GS gene supports the unique advantages of the ZFN technology, especially in CHO cells. GS enzyme function disruption was confirmed by the observation of glutamine-dependent growth of all GS-knockout cell lines. Full evaluation of the GS-knockout cell lines in a standard industrial cell culture process was performed. Bulk culture productivity improved two- to three-fold through the use of GS-knockout cells as parent cells. The selection stringency was

Photoperiodic regulation of glycogen metabolism, glycolysis, and glutamine synthesis in tanycytes of the Siberian hamster suggests novel roles of tanycytes in hypothalamic function.

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Nilaweera, Kanishka; Herwig, Annika; Bolborea, Matei; Campbell, Gill; Mayer, Claus D; Morgan, Peter J; Ebling, Francis J P; Barrett, Perry

2011-11-01

The objective of this study is to investigate the impact of photoperiod on the temporal and spatial expression of genes involved in glucose metabolism in the brain of the seasonal mammal Phodopus sungorus (Siberian hamster). In situ hybridization was performed on brain sections obtained from male hamsters held in long photoperiod (high body weight and developed testes) or short photoperiod (reduced body weight with testicular regression). This analysis revealed upregulation in expression of genes involved in glycogen and glucose metabolism in short photoperiod and localized to the tanycyte layer of the third ventricle. On the basis of these data and a previously identified photoperiod-dependent increase in activity of neighboring hypothalamic neurons, we hypothesized that the observed expression changes may reflect alteration in either metabolic fuel or precursor neurotransmitter supply to surrounding neurons. Gene expression analysis was performed for genes involved in lactate and glutamate transport. This analysis showed that the gene for the lactate transporter MCT2 and glutamate transporter GLAST was decreased in the tanycyte layer in short photoperiod. Expression of mRNA for glutamine synthetase, the final enzyme in the synthesis of the neuronal neurotransmitter precursor, glutamine, was also decreased in short photoperiod. These data suggest a role for tanycytes in modulating glutamate concentrations and neurotransmitter supply in the hypothalamic environment. Copyright © 2011 Wiley-Liss, Inc.

Light induces changes in activities of Na+/K+(NH4+-ATPase, H+/K+(NH4+-ATPase and glutamine synthetase in tissues involved directly or indirectly in light-enhanced calcification in the giant clam Tridacna squamosa

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Alex Y K Ip

2015-03-01

Full Text Available The objective of this study was to determine the effects of 12 h of exposure to light, as compared with 12 h of exposure to darkness (control, on enzymatic activities of transporters involved in the transport of NH4+ or H+, and activities of enzymes involved in converting NH4+ to glutamate/glutamine in inner mantle, outer mantle and ctenidia of the giant clam, Tridacna squamosa. Exposure to light resulted in a significant increase in the effectiveness of NH4+ in substitution for K+ to activate Na+/K+-ATPase (NKA, manifested as a significant increase in the Na+/NH4+-activated-NKA activity in the inner mantle. However, similar phenomena were not observed in the extensible outer mantle, which contained abundant symbiotic zooxanthellae. Hence, during light-enhanced calcification, H+ released from CaCO3 deposition could react with NH3 to form NH4+ in the extrapallial fluid, and NH4+ could probably be transported into the shell-facing inner mantle epithelium through NKA. Light also induced an increase in the activity of glutamine synthetase, which converts NH4+ and glutamate to glutamine, in the inner mantle. Taken together, these results explained observations reported elsewhere that light induced a significant increase in pH and a significant decrease in ammonia concentration in the extrapallial fluid, as well as a significant increase in the glutamine concentration in the inner mantle, of T. squamosa. Exposure of T. squamosa to light also led to a significant decrease in the N-ethylmaleimide (NEM-sensitive-V-H+-ATPase (VATPase in the inner mantle, and significant increases in the Na+/K+-activated-NKA, H+/NH4+-activated-H+/K+-ATPase and NEM-sensitive-VATPase activities in ctenidia, indicating that light-enhanced calcification might perturb Na+ homeostasis and acid/base balance in the hemolymph, and might involve the active uptake of NH4+ from the environment. This is the first report on light having direct enhancing effects on activities of certain

Mid-Season Leaf Glutamine Predicts End-Season Maize Grain Yield and Nitrogen Content in Response to Nitrogen Fertilization under Field Conditions

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Travis Goron

2017-06-01

Full Text Available After uptake in cereal crops, nitrogen (N is rapidly assimilated into glutamine (Gln and other amino acids for transport to sinks. Therefore Gln has potential as an improved indicator of soil N availability compared to plant N demand. Gln has primarily been assayed to understand basic plant physiology, rather than to measure plant/soil-N under field conditions. It was hypothesized that leaf Gln at early-to-mid season could report the N application rate and predict end-season grain yield in field-grown maize. A three-year maize field experiment was conducted with N application rates ranging from 30 to 218 kg ha−1. Relative leaf Gln was assayed from leaf disk tissue using a whole-cell biosensor for Gln (GlnLux at the V3-V14 growth stages. SPAD (Soil Plant Analysis Development and NDVI (Normalized Difference Vegetation Index measurements were also performed. When sampled at V6 or later, GlnLux glutamine output consistently correlated with the N application rate, end-season yield, and grain N content. Yield correlation outperformed GreenSeekerTM NDVI, and was equivalent to SPAD chlorophyll, indicating the potential for yield prediction. Additionally, depleting soil N via overplanting increased GlnLux resolution to the earlier V5 stage. The results of the study are discussed in the context of luxury N consumption, leaf N remobilization, senescence, and grain fill. The potential and challenges of leaf Gln and GlnLux for the study of crop N physiology, and future N management are also discussed.

De Novo Glutamine Synthesis: Importance for the Proliferation of Glioma Cells and Potentials for Its Detection With 13N-Ammonia.

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He, Qiao; Shi, Xinchong; Zhang, Linqi; Yi, Chang; Zhang, Xuezhen; Zhang, Xiangsong

2016-01-01

The aim of this study was to investigate the role of de novo glutamine (Gln) synthesis in the proliferation of C6 glioma cells and its detection with (13)N-ammonia. Chronic Gln-deprived C6 glioma (0.06C6) cells were established. The proliferation rates of C6 and 0.06C6 cells were measured under the conditions of Gln deprivation along with or without the addition of ammonia or glutamine synthetase (GS) inhibitor. (13)N-ammonia uptake was assessed in C6 cells by gamma counting and in rats with C6 and 0.06C6 xenografts by micro-positron emission tomography (PET) scanning. The expression of GS in C6 cells and xenografts was assessed by Western blotting and immunohistochemistry, respectively. The Gln-deprived C6 cells showed decreased proliferation ability but had a significant increase in GS expression. Furthermore, we found that low concentration of ammonia was sufficient to maintain the proliferation of Gln-deprived C6 cells, and (13)N-ammonia uptake in C6 cells showed Gln-dependent decrease, whereas inhibition of GS markedly reduced the proliferation of C6 cells as well as the uptake of (13)N-ammoina. Additionally, microPET/computed tomography exhibited that subcutaneous 0.06C6 xenografts had higher (13)N-ammonia uptake and GS expression in contrast to C6 xenografts. De novo Gln synthesis through ammonia-glutamate reaction plays an important role in the proliferation of C6 cells. (13)N-ammonia can be a potential metabolic PET tracer for Gln-dependent tumors. © The Author(s) 2016.

Effect of Nutrient Dilution and Glutamine Supplementation on Growth Performance, Small Intestine Morphology and Immune Response of Broilers

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majid gheshlagh olyayee

2016-11-01

Full Text Available Introduction Glutamine (Gln, a semi-essential or conditionally essential amino acid, is an abundant amino acid in plasma and skeletal muscle. It is the main energy substrate for cells that undergo intense replication, such as enterocytes, lymphocytes, macrophages, neutrophils and kidney cells and plays an important role in their function and homeostasis. Apart from providing nitrogen for protein synthesis, Gln is a precursor for nucleic acids, nucleotides, hexose amines, the nitric oxide precursor arginine (Arg, and the major antioxidant-glutathione. It plays a central role in nitrogen transport between tissues, specifically from muscle to gut, kidney, and liver. In addition to its role as a gluconeogenic substrate in the liver, kidney, and intestine, Gln is involved in the renal handling of ammonia, serving as a regulator of acid base homeostasis. So the aim of this study was to evaluate the effect of nutrient dilution and L- glutamine (Gln supplementation on growth performance, intestine morphology and immune response of broilers during starter (0 to 10 days, growth (11 to 24 days and finisher (25 to 42 days periods. Materials and methods A total of 320 one-day-old male Ross 308 broiler chicks were randomly assigned to eight treatments with 4 replicates and 10 chicks per each. In this study two levels of nutrient dilution (Ross 308 broiler nutrition recommendation and 5% diluted and 4 levels of Gln supplementation (0, 0.5, 1 and 1.5% were used in a completely randomized design as factorial arrangement 2×4. Growth performance was measured periodically. In order to investigate jejenual histomorphology such as villus height, depth of crypt, villus height to depth of crypt ratio, villus width, muscle layer thickness and epithelium thickness, on day 42 after 4 h fasting, one bird per each replicate was randomly selected, slaughtered and 1 cm of middle section of jejenum was cut. Cellular immune response was assessed in 40-d-old chick using the in

Amino acid metabolism of Lemna minor L

International Nuclear Information System (INIS)

Rhodes, D.; Rich, P.J.; Brunk, D.G.

1989-01-01

A serious limitation to the use of N(O,S)-heptafluorobutyryl isobutyl amino acid derivatives in the analysis of 15 N-labeling kinetics of amino acids in plant tissues, is that the amides glutamine and asparagine undergo acid hydrolysis to glutamate and aspartate, respectively, during derivatization. This led us to consider an alternative procedure for derivatization of glutamine and asparagine with N-methyl-N-(tert-butyldimethylsilyl)-trifluoroacetamide in pyridine. Gas chromatography-mass spectrometry yielded fragment ions (M-57) of mass 417 and 431 for the [ 14 N]asparagine and [ 14 N]glutamine derivatives, respectively, suitable for monitoring unlabeled, single- 15 N- and double- 15 N-labeled amide species from the ion clusters at mass to charge ratio (m/z) 415 to 423 for asparagine, and m/z 429 to 437 for glutamine. From separate analyses of the specific isotope abundance of the amino-N groups of asparagine and glutamine as their N-heptafluorobutyryl isobutyl derivatives, the specific amide-[ 15 N] abundance of these amino acids was determined

Social isolation stress and chronic glutathione deficiency have a common effect on the glutamine-to-glutamate ratio and myo-inositol concentration in the mouse frontal cortex.

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Corcoba, Alberto; Gruetter, Rolf; Do, Kim Q; Duarte, João M N

2017-09-01

Environmental stress can interact with genetic predisposition to increase the risk of developing psychopathology. In this work, we tested the hypothesis that social isolation stress interacts with impaired glutathione synthesis and have cumulative effects on the neurochemical profile of the frontal cortex. A mouse model with chronic glutathione deficit induced by knockout (-/-) of the glutamate-cysteine ligase modulatory subunit (Gclm) was exposed to social isolation stress from weaning to post-natal day 65. Using magnetic resonance methods at high-field (14.1 T), we analysed the neurochemical profile in the frontal cortex, brain size and ventricular volume of adult animals. Glutathione deficit was accompanied by elevated concentrations of N-acetylaspartate, alanine, and glutamine, as well as the ratio of glutamine-to-glutamate (Gln/Glu), and by a reduction in levels of myo-inositol and choline-containing compounds in the frontal cortex of -/- animals with respect to wild-type littermates. Although there was no significant interaction between social isolation stress and glutathione deficiency, mice reared in isolation displayed lower myo-inositol concentration (-8.4%, p social isolation had no effect on these parameters. We conclude that social isolation caused neurochemical alterations that may add to those associated to impaired glutathione synthesis. © 2017 International Society for Neurochemistry.

A sub-threshold dose of pilocarpine increases glutamine synthetase in reactive astrocytes and enhances the progression of amygdaloid-kindling epilepsy in rats.

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Sun, Hong-Liu; Deng, Da-Ping; Pan, Xiao-Hong; Wang, Chao-Yun; Zhang, Xiu-Li; Chen, Xiang-Ming; Wang, Chun-Hua; Liu, Yu-Xia; Li, Shu-Cui; Bai, Xian-Yong; Zhu, Wei

2016-03-02

The prognosis of patients exposed to a sub-threshold dose of a proconvulsant is difficult to establish. In this study, we investigated the effect of a single sub-threshold dose of the proconvulsant pilocarpine (PILO) on the progression of seizures that were subsequently induced by daily electrical stimulation (kindling) of the amygdaloid formation. Male Sprague–Dawley rats were each implanted with an electrode in the right basolateral amygdala and an indwelling cannula in the right ventricle. The animals were randomized into groups and were administered one of the following treatments: saline, PILO, saline+L-α-aminoadipic acid (L-AAA; one dosage tested), PILO+L-AAA, or PILO+L-methionine sulfoximine (three dosages tested). Amygdaloid stimulation and electroencephalography were performed once daily. We performed immunohistochemistry and western blot for glial fibrillary acidic protein and glutamine synthetase (GS). We also assayed the enzymic activity of GS in discrete brain regions. An intraperitoneal injection of a sub-threshold PILO dose enhanced the progression of amygdaloid-kindling seizures and was accompanied by an increase in reactive-astrocyte and GS (content and activity) in the hippocampus and piriform cortex. L-AAA and L-methionine sulfoximine, inhibitors of astrocytic and GS function, respectively, abolished the effect of PILO on amygdaloid-kindling seizures. We conclude that one sub-threshold dose of a proconvulsant may enhance the progression of subsequent epilepsy and astrocytic GS may play a role in this phenomenon. Thus, a future therapy for epilepsy could be inhibition of astrocytes and/or GS.

Glutamine synthetase activity in solanaceous cell suspensions accumulating alkaloids or not. {sup 13}C NMR and enzymatic assay; Activite de la glutamine synthetase dans des suspensions cellulaires de solanacees productrices ou non d'alcaloides. RMN du {sup 13}C et dosage enzymatique

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Mesnard, F.; Marty, D.; Monti, J.P. [Faculte de Pharmacie, 80 - Amiens (France). Laboratoire de Biophysique, Groupe de Recherche des Biomolecules: micro-environnement et Metabolisme; Gillet-Manceau, F.; Fliniaux, M.A. [Faculte de Pharmacie, 80 - Amiens (France). Laboratoire de Phytotechnologie

1999-09-01

The metabolism of labelled pyruvate followed by {sup 13}C NMR and the measure of glutamine synthetase (GS) showed, according to previous results, a high activity of this enzyme in suspension cells of Nicotiana plumbaginifolia. This activity could derive glutamate from the alkaloidsynthesizing pathways. However, a recent work showed that the rate of the GS gene transcription was inversely proportional to the Gln/Glu ratio. The measures of Gln and Glu concentrations in Nicotiana plumbaginifolia cells revealed that high GS activity correlates with the weak value of Gln/Glu ratio. Therefore, the hypothesis of GS dysfunction for the non-biosynthesis of alkaloids in N. plumbaginifolia suspension cells can be discarded. This conclusion is strengthened by the results obtained when using a GS inhibitor. (author)

The effects of glutamine-supplemented diet on the intestinal mucosa of the malnourished growing rat Os efeitos de dieta com suplementação de glutamina sobre a mucosa intestinal do rato desnutrido em crescimento

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Uenis Tannuri

2000-06-01

Full Text Available Glutamine is the most abundant amino acid in the blood and plays a key role in the response of the small intestine to systemic injuries. Mucosal atrophy is an important phenomenon that occurs in some types of clinical injury, such as states of severe undernutrition. Glutamine has been shown to exert powerful trophic effects on the gastrointestinal mucosa after small bowel resection or transplant, radiation injury, surgical trauma, ischemic injury and administration of cytotoxic drugs. Since no study has been performed on the malnourished animal, we examined whether glutamine exerts a trophic effect on the intestinal mucosa of the malnourished growing rat. Thirty-five growing female rats (aged 21 days were divided into 4 groups: control - chow diet; malnutrition diet; malnutrition+chow diet; and malnutrition+glutamine-enriched chow diet (2%. For the first 15 days of the experiment, animals in the test groups received a malnutrition diet, which was a lactose-enriched diet designed to induce diarrhea and malnutrition. For the next 15 days, these animals received either the lactose-enriched diet, a regular chow diet or a glutamine-enriched chow diet. After 30 days, the animals were weighed, sacrificed, and a section of the jejunum was taken and prepared for histological examination. All the animals had similar weights on day 1 of experiment, and feeding with the lactose-enriched diet promoted a significant decrease in body weight in comparison to the control group. Feeding with both experimental chow-based diets promoted significant body weight gains, although the glutamine-enriched diet was more effective. RESULTS: The morphological and morphometric analyses demonstrated that small intestinal villous height was significantly decreased in the malnourished group, and this change was partially corrected by the two types of chow-based diet. Crypt depth was significantly increased by malnutrition, and this parameter was partially corrected by the two

The effect of oral supplementation with a combination of beta-hydroxy-beta-methylbutyrate, arginine and glutamine on wound healing: a retrospective analysis of diabetic haemodialysis patients

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Sipahi, Savas; Gungor, Ozkan; Gunduz, Mehmet; Cilci, Mehmet; Demirci, Mustafa Cahit; Tamer, Ali

2013-01-01

Background Diabetes is an important reason for end-stage renal failure and diabetic foot wounds worsen the life qualities of these patients. Protein and amino acid support accelerates the wound healing. The purpose of this retrospective study is to examine the effect of beta-hydroxy-beta-methylbutyrate, arginine and glutamine (Abound?) supplementation on the wound healing. Methods A total of 11 diabetic dialysis patients were included in this retrospective study aiming to evaluate the effect ...

Weight loss and morphometric study of intestinal mucosa in rats after massive intestinal resection: influence of a glutamine-enriched diet Perda de peso e estudo morfométrico da mucosa intestinal de ratos submetidos à ressecção subtotal de intestino delgado: influência do uso de dieta com glutamina

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Sidney Resende Ribeiro

2004-01-01

Full Text Available Short-bowel syndrome is responsible for significant metabolic alterations that compromise nutritional status. Glutamine is considered an essential nutrient for enterocytes, so beneficial effects from supplementation of the diet with glutamine are hypothesized. PURPOSE: In this study, the effect of a diet enriched with glutamine was evaluated in rats undergoing extensive small bowel resection, with analysis of postoperative weight loss and intestinal morphometrics of villi height, crypt depth, and thickness of the duodenal and remnant jejunal mucosa. METHODS: Three groups of male Wistar rats were established receiving the following diets: with glutamine, without glutamine, and the standard diet of laboratory ration. All animals underwent an extensive small bowel resection, including the ileocecal valve, leaving a remnant jejunum of only 25 cm from the pylorus that was anastomosed lateral-laterally to the ascendant colon. The animals were weighed at the beginning and end of the experiment (20th postoperative day. Then they were killed and the remnant intestine was removed. Fragments of duodenal and jejunal mucosa were collected from the remnant intestine and submitted to histopathologic exam. The morphometric study of the intestinal mucosa was accomplished using a digital system (KS 300 connected to an optic microscope. Morphometrics included villi height, crypt depth, and the total thickness of intestinal mucosa. RESULTS: The weight loss comparison among the 3 groups showed no significant loss difference. The morphometric studies showed significantly taller duodenal villi in the glutamine group in comparison to the without glutamine group, but not different from the standard diet group. The measurements obtained comparing the 3 groups for villi height, crypt depth, and thickness of the remnant jejunum mucosa were greater in the glutamine-enriched diet group than for the without-glutamine diet group, though not significantly different from with

Engineering Escherichia coli Nicotinic Acid Mononucleotide Adenylyltransferase for Fully Active Amidated NAD Biosynthesis.

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Wang, Xueying; Zhou, Yongjin J; Wang, Lei; Liu, Wujun; Liu, Yuxue; Peng, Chang; Zhao, Zongbao K

2017-07-01

NAD and its reduced form NADH function as essential redox cofactors and have major roles in determining cellular metabolic features. NAD can be synthesized through the deamidated and amidated pathways, for which the key reaction involves adenylylation of nicotinic acid mononucleotide (NaMN) and nicotinamide mononucleotide (NMN), respectively. In Escherichia coli , NAD de novo biosynthesis depends on the protein NadD-catalyzed adenylylation of NaMN to nicotinic acid adenine dinucleotide (NaAD), followed by NAD synthase-catalyzed amidation. In this study, we engineered NadD to favor NMN for improved amidated pathway activity. We designed NadD mutant libraries, screened by a malic enzyme-coupled colorimetric assay, and identified two variants, 11B4 (Y84V/Y118D) and 16D8 (A86W/Y118N), with a high preference for NMN. Whereas in the presence of NMN both variants were capable of enabling the viability of cells of E. coli BW25113-derived NAD-auxotrophic strain YJE003, for which the last step of the deamidated pathway is blocked, the 16D8 expression strain could grow without exogenous NMN and accumulated a higher cellular NAD(H) level than BW25113 in the stationary phase. These mutants established fully active amidated NAD biosynthesis and offered a new opportunity to manipulate NAD metabolism for biocatalysis and metabolic engineering. IMPORTANCE Adenylylation of nicotinic acid mononucleotide (NaMN) and adenylylation of nicotinamide mononucleotide (NMN), respectively, are the key steps in the deamidated and amidated pathways for NAD biosynthesis. In most organisms, canonical NAD biosynthesis follows the deamidated pathway. Here we engineered Escherichia coli NaMN adenylyltransferase to favor NMN and expressed the mutant enzyme in an NAD-auxotrophic E. coli strain that has the last step of the deamidated pathway blocked. The engineered strain survived in M9 medium, which indicated the implementation of a functional amidated pathway for NAD biosynthesis. These results enrich

Mineral nitrogen sources differently affect root glutamine synthetase isoforms and amino acid balance among organs in maize.

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Prinsi, Bhakti; Espen, Luca

2015-04-03

Glutamine synthetase (GS) catalyzes the first step of nitrogen assimilation in plant cell. The main GS are classified as cytosolic GS1 and plastidial GS2, of which the functionality is variable according to the nitrogen sources, organs and developmental stages. In maize (Zea mays L.) one gene for GS2 and five genes for GS1 subunits are known, but their roles in root metabolism are not yet well defined. In this work, proteomic and biochemical approaches have been used to study root GS enzymes and nitrogen assimilation in maize plants re-supplied with nitrate, ammonium or both. The plant metabolic status highlighted the relevance of root system in maize nitrogen assimilation during both nitrate and ammonium nutrition. The analysis of root proteomes allowed a study to be made of the accumulation and phosphorylation of six GS proteins. Three forms of GS2 were identified, among which only the phosphorylated one showed an accumulation trend consistent with plastidial GS activity. Nitrogen availabilities enabled increments in root total GS synthetase activity, associated with different GS1 isoforms according to the nitrogen sources. Nitrate nutrition induced the specific accumulation of GS1-5 while ammonium led to up-accumulation of both GS1-1 and GS1-5, highlighting co-participation. Moreover, the changes in thermal sensitivity of root GS transferase activity suggested differential rearrangements of the native enzyme. The amino acid accumulation and composition in roots, xylem sap and leaves deeply changed in response to mineral sources. Glutamine showed the prevalent changes in all nitrogen nutritions. Besides, the ammonium nutrition was associated with an accumulation of asparagine and reducing sugars and a drop in glutamic acid level, significantly alleviated by the co-provision with nitrate. This work provides new information about the multifaceted regulation of the GS enzyme in maize roots, indicating the involvement of specific isoenzymes/isoforms, post

Gene expression, cellular localisation and function of glutamine synthetase isozymes in wheat (Triticum aestivum L.)

DEFF Research Database (Denmark)

Bernard, Stéphanie M.; Møller, Anders Laurell Blom; Dionisio, Giuseppe

2008-01-01

). Phylogenetic analysis showed that the wheat GS sub-families together with the GS genes from other monocotyledonous species form four distinct clades. Immunolocalisation studies in leaves, stems and rachis in plants at flowering showed GS protein to be present in parenchyma, phloem companion and perifascicular......We present the first cloning and study of glutamine synthetase (GS) genes in wheat (Triticum aestivum L.). Based on sequence analysis, phylogenetic studies and mapping data, ten GS sequences were classified into four sub-families: GS2 (a, b and c), GS1 (a, b and c), GSr (1 and 2) and GSe (1 and 2...... sheath cells. In situ localisation confirmed that GS1 transcripts were present in the perifascicular sheath cells whilst those for GSr were confined to the vascular cells. Studies of the expression and protein profiles showed that all GS sub-families were differentially expressed in the leaves, peduncle...

Regulation of glutamine synthetase isoforms in two differentially drought-tolerant rice (Oryza sativa L.) cultivars under water deficit conditions.

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Singh, Kamal Krishna; Ghosh, Shilpi

2013-02-01

KEY MESSAGE : The regulation of GS isoforms by WD was organ specific. Two GS isoforms i.e. OsGS1;1 and OsGS2 were differentially regulated in IR-64 (drought-sensitive) and Khitish (drought-tolerant) cultivars of rice. Water deficit (WD) has adverse effect on rice (Oryza sativa L.) and acclimation requires essential reactions of primary metabolism to continue. Rice plants utilize ammonium as major nitrogen source, which is assimilated into glutamine by the reaction of Glutamine synthetase (GS, EC 6.3.1.2). Rice plants possess one gene (OsGS2) for chloroplastic GS2 and three genes (OsGS1;1, OsGS1;2 and OsGS1;3) for cytosolic GS1. Here, we report the effect of WD on regulation of GS isoforms in drought-sensitive (cv. IR-64) and drought-tolerant (cv. Khitish) rice cultivars. Under WD, total GS activity in root and leaf decreased significantly in IR-64 seedlings in comparison to Khitish seedlings. The reduced GS activity in IR-64 leaf was mainly due to decrease in GS2 activity, which correlated with decrease in corresponding transcript and polypeptide contents. GS1 transcript and polypeptide accumulated in leaf during WD, however, GS1 activity was maintained at a constant level. Total GS activity in stem of both the varieties was insensitive to WD. Among GS1 genes, OsGS1;1 expression was differently regulated by WD in the two rice varieties. Its transcript accumulated more abundantly in IR-64 leaf than in Khitish leaf. Following WD, OsGS1;1 mRNA level in stem and root tissues declined in IR-64 and enhanced in Khitish. A steady OsGS1;2 expression patterns were noted in leaf, stem and root of both the cultivars. Results suggest that OsGS2 and OsGS1;1 expression may contribute to drought tolerance of Khitish cultivar under WD conditions.

Conformational changes induced by Mg2+ on the multiple forms of glutamine synthetase from Bacillus brevis Bb G1

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Suja Abraham

2013-01-01

Full Text Available Conformational changes play an important role in the function of proteins. Glutamine synthetase, an important enzyme of nitrogen metabolism, was purified under sporulating (GSala and non-sporulating (GSpyr conditions and the effect of Mg2+ on these multiple forms was studied by fluorescence spectroscopy to detect possible conformational changes that occur in the presenceof Mg2+. The substantial changes in the fluorescence emission maximum, fluorescence intensity and lifetime that occur in the presence of different concentrations of Mg2+, indicated major changes in molecular conformations in both forms of this enzyme. The fluorescent changes produced by the effect of Mg2+ in GSala was much more prominent than in GSpyr. These observations strongly support the possibility that GSala and GSpyr undergoes a conformational change on binding with Mg2+.

Stereospecific assignment of the NH2 resonances from the primary amides of asparagine and glutamine side chains in isotopically labeled proteins

International Nuclear Information System (INIS)

McIntosh, Lawrence P.; Brun, Emmanuel; Kay, Lewis E.

1997-01-01

An HMQC-based pulse scheme is presented for the stereospecific assignment of asparagine and glutamine side-chain amide protons. The approach makes use of the recently developed quantitative-J correlation spectroscopy [Bax, A. et al. (1994) Methods Enzymol., 239,79-105] to distinguish the E and Z primary amide protons and, as such, eliminates the need for assignments derived from more time-consuming and potentially ambiguous NOE methods. An application of this method to a uniformly 15N,13C-labeled cellulose-binding domain is presented. When used in combination with a NOESY-HSQC experiment, the predominant χ2 dihedral angles of two asparagine side chains in this protein can also be defined

A Novel, In-solution Separation of Endogenous Cardiac Sarcomeric Proteins and Identification of Distinct Charged Variants of Regulatory Light Chain*

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Scruggs, Sarah B.; Reisdorph, Rick; Armstrong, Mike L.; Warren, Chad M.; Reisdorph, Nichole; Solaro, R. John; Buttrick, Peter M.

2010-01-01

The molecular conformation of the cardiac myosin motor is modulated by intermolecular interactions among the heavy chain, the light chains, myosin binding protein-C, and titin and is governed by post-translational modifications (PTMs). In-gel digestion followed by LC/MS/MS has classically been applied to identify cardiac sarcomeric PTMs; however, this approach is limited by protein size, pI, and difficulties in peptide extraction. We report a solution-based work flow for global separation of endogenous cardiac sarcomeric proteins with a focus on the regulatory light chain (RLC) in which specific sites of phosphorylation have been unclear. Subcellular fractionation followed by OFFGEL electrophoresis resulted in isolation of endogenous charge variants of sarcomeric proteins, including regulatory and essential light chains, myosin heavy chain, and myosin-binding protein-C of the thick filament. Further purification of RLC using reverse-phase HPLC separation and UV detection enriched for RLC PTMs at the intact protein level and provided a stoichiometric and quantitative assessment of endogenous RLC charge variants. Digestion and subsequent LC/MS/MS unequivocally identified that the endogenous charge variants of cardiac RLC focused in unique OFFGEL electrophoresis fractions were unphosphorylated (78.8%), singly phosphorylated (18.1%), and doubly phosphorylated (3.1%) RLC. The novel aspects of this study are that 1) milligram amounts of endogenous cardiac sarcomeric subproteome were focused with resolution comparable with two-dimensional electrophoresis, 2) separation and quantification of post-translationally modified variants were achieved at the intact protein level, 3) separation of intact high molecular weight thick filament proteins was achieved in solution, and 4) endogenous charge variants of RLC were separated; a novel doubly phosphorylated form was identified in mouse, and singly phosphorylated, singly deamidated, and deamidated/phosphorylated forms were

Purification, crystallization and preliminary X-ray diffraction analysis of GatD, a glutamine amidotransferase-like protein from Staphylococcus aureus peptidoglycan.

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Vieira, Diana; Figueiredo, Teresa A; Verma, Anil; Sobral, Rita G; Ludovice, Ana M; de Lencastre, Hermínia; Trincao, Jose

2014-05-01

Amidation of peptidoglycan is an essential feature in Staphylococcus aureus that is necessary for resistance to β-lactams and lysozyme. GatD, a 27 kDa type I glutamine amidotransferase-like protein, together with MurT ligase, catalyses the amidation reaction of the glutamic acid residues of the peptidoglycan of S. aureus. The native and the selenomethionine-derivative proteins were crystallized using the sitting-drop vapour-diffusion method with polyethylene glycol, sodium acetate and calcium acetate. The crystals obtained diffracted beyond 1.85 and 2.25 Å, respectively, and belonged to space group P212121. X-ray diffraction data sets were collected at Diamond Light Source (on beamlines I02 and I04) and were used to obtain initial phases.

Glutamine Synthetases GLN1;2 and GLN2 in Relation to Arabidopsis Growth Response to Elevated Atmospheric Carbon Dioxide and Varying Nitrogen Forms

DEFF Research Database (Denmark)

Vurrakula, Swathi

content while diluting nitrogen concentrations. Such a reduction in nitrogen concentration will affect plant response to stress and seed/grain yield. Glutamine synthetase (GS) is the central nitrogen-assimilatory enzyme, performing primary and secondary nitrogen assimilation, in response to environmental....... Plants grown under elevated CO2 absorbed ammonia from the atmosphere, except with a high ammonium supply. GLN1;2 had a non-redundant role in determining vegetative growth and ammonium tolerance in response to elevated CO2. Under elevated CO2, GLN1;2 was compensable by GLN2 in assimilating nitrate...

A novel glutamine-rich putative transcriptional adaptor protein (TIG-1), preferentially expressed in placental and bone-marrow tissues.

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Abraham, S; Solomon, W B

2000-09-19

We used a subtractive hybridization protocol to identify novel expressed sequence tags (ESTs) corresponding to mRNAs whose expression was induced upon exposure of the human leukemia cell line K562 to the phorbol ester 12-O-tetradecanolyphorbol-13-acetate (TPA). The complete open reading frame of one of the novel ESTs, named TIG-1, was obtained by screening K562 cell and placental cDNA libraries. The deduced open reading frame of the TIG-1 cDNA encodes for a glutamine repeat-rich protein with a predicted molecular weight of 63kDa. The predicted open reading frame also contains a consensus bipartite nuclear localization signal, though no specific DNA-binding domain is found. The corresponding TIG-1 mRNA is ubiquitously expressed. Placental tissue expresses the TIG-1 mRNA 200 times more than the lowest expressing tissues such as kidney and lung. There is also preferential TIG-1 mRNA expression in cells of bone-marrow lineage.In-vitro transcription/translation of the TIG-1 cDNA yielded a polypeptide with an apparent molecular weight of 97kDa. Using polyclonal antibodies obtained from a rabbit immunized with the carboxy-terminal portion of bacterially expressed TIG-1 protein, a polypeptide with molecular weight of 97kDa was identified by Western blot analyses of protein lysates obtained from K562 cells. Cotransfection assays of K562 cells, using a GAL4-TIG-1 fusion gene and GAL4 operator-CAT, indicate that the TIG-1 protein may have transcriptional regulatory activity when tethered to DNA. We hypothesize that this novel glutamine-rich protein participates in a protein complex that regulates gene transcription. It has been demonstrated by Naar et al. (Naar, A.M., Beaurang, P.A., Zhou, S., Abraham, S., Solomon, W.B., Tjian, R., 1999, Composite co-activator ARC mediates chromatin-directed transcriptional activation. Nature 398, 828-830) that the amino acid sequences of peptide fragments obtained from a polypeptide found in a complex of proteins that alters chromatin

Adição de alanina, glicina e glutamina ao meio crioprotetor seminal de garanhões Mangalarga Marchador Addition of alanine, glycine and glutamine to frozen seminal extender from Mangalarga Marchador stallions

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Bruno Fagundes

2010-02-01

Full Text Available Objetivou-se neste trabalho verificar o efeito da adição de alanina, glicina e glutamina ao meio crioprotetor seminal de garanhões Mangalarga Marchador. Foram utilizados cinco garanhões provenientes do haras Lugavi. Três ejaculados de cada garanhão, após coleta e avaliação, foram divididos em seis tratamentos: sem adição de aminoácidos, adição de 40 mM de alanina, adição de 40 mM de glicina, adição de 60 mM de glutamina, adição de 7 mM de alanina + 7 mM de glicina + 20 mM de glutamina e adição de 40 mM de alanina + 40 mM de glicina + 60 mM de glutamina ao diluente de congelamento convencional. Foram avaliados os parâmetros motilidade total, motilidade progressiva, retidão, linearidade, velocidade média do percurso, velocidade linear, velocidade curvilínea, amplitude lateral de cabeça e frequência de batimentos dos espermatozoides por meio de análise espermática assistida por computador (CASA, funcionalidade da membrana plasmática por choque hiposmótico e integridade de membrana acrossomal pelo teste FITC-PSA. Não houve melhora nos parâmetros de motilidade e cinética espermática nem na funcionalidade de membrana, entretanto, a adição de aminoácidos ao meio crioprotetor seminal aumentou o número de espermatozoides com membrana acrossomal íntegra. Os melhores resultados neste teste são obtidos com 40 mM de alanina (78,6 ± 13,6, 40 mM de glicina (74,7 ± 19,6 ou 7 mM de alanina + 7 mM de glicina + 20 mM de glutamina (76,8 ± 17,5, porém outros estudos devem ser realizados para determinação da concentração ideal desses componentes.The objective of this study was to analyze the effect of the addition of alanine, glycine and glutamine on frozen seminal extender of Mangalarga marchador breed stallions. Five stallions were used from the Lugavi stables. Three ejaculates from each stallion were divided into six treatments: without the addition of amino acids, addition of 40 mM alanine, addition of 40 m

Growth hormone increases and maturation decreases glutamine synthetase turnover rate in rat liver

International Nuclear Information System (INIS)

Lin, C.K.

1985-01-01

An investigation was made of the effect of hypophysectomy and growth hormone (GH) replacement regimen (1 mg/100 g twice daily for 30 days); and maturation (from 25 up to 90 days) on the liver and brain glutamine synthetase (GS) mass and turnover rates in rats. The first order decay rate of enzyme 14 C radioactivity was determined between 1 and 4 days to obtain the half-life (T/sub 1/2/) of GS. The hepatic GS mass was determined by immunoassay. GS turnover (GS/sub s/) was calculated from T/sub 1/2/ and the GS mass (i.e., K = 0.693/T/sub 1/2/; GS/sub s/ = K x GS mass). It was concluded that: (1) GS specific activity is not decreased by hypophysectomy or increased by GH. These results suggested that observed endocrine induced changes in GS are due to changes in GS mass. (2) The liver GS turnover rate is significantly reduced by hypophysectomy and increased by GH replacement. It was proposed that GH specifically enhances synthesis of GS in the liver. (3) Maturation (25, 40, 60, and 90 days) decreases GS turnover rate in both liver and brain of normal rats. This similar effect of maturation suggests that the observed age induced decline in GS turnover rate is not related to GH in all tissues

Elevated prefrontal cortex γ-aminobutyric acid and glutamate-glutamine levels in schizophrenia measured in vivo with proton magnetic resonance spectroscopy.

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Kegeles, Lawrence S; Mao, Xiangling; Stanford, Arielle D; Girgis, Ragy; Ojeil, Najate; Xu, Xiaoyan; Gil, Roberto; Slifstein, Mark; Abi-Dargham, Anissa; Lisanby, Sarah H; Shungu, Dikoma C

2012-05-01

Postmortem studies have found evidence of γ-aminobutyric acid (GABA) deficits in fast-spiking, parvalbumin-positive interneurons in the prefrontal cortex in schizophrenia. Magnetic resonance spectroscopy studies in unmedicated patients have reported glutamine or glutamate-glutamine (Glx) elevations in this region. Abnormalities in these transmitters are thought to play a role in cognitive impairments in the illness. To measure GABA and Glx levels in vivo in 2 prefrontal brain regions in unmedicated and medicated patients with schizophrenia and healthy controls. Case-control study. Inpatient psychiatric research unit and associated outpatient clinic. Sixteen unmedicated patients with schizophrenia, 16 medicated patients, and 22 healthy controls matched for age, sex, ethnicity, parental socioeconomic status, and cigarette smoking. Proton magnetic resonance spectroscopy with a 3-T system and the J-edited spin-echo difference method. The GABA and Glx levels were measured in the dorsolateral and medial prefrontal cortex and normalized to the simultaneously acquired water signal. Working memory performance was assessed in all subjects. The GABA and Glx concentrations determined by proton magnetic resonance spectroscopy. In the medial prefrontal cortex region, 30% elevations were found in GABA (P = .02) and Glx (P = .03) levels in unmedicated patients compared with controls. There were no alterations in the medicated patients or in either group in the dorsolateral prefrontal cortex. Both regions showed correlations between GABA and Glx levels in patients and controls. No correlations with working memory performance were found. To our knowledge, this study presents the first GABA concentration measurements in unmedicated patients with schizophrenia, who showed elevations in both GABA and Glx levels in the medial prefrontal cortex but not the dorsolateral prefrontal cortex. Medicated patients did not show these elevations, suggesting possible normalization of levels with

Central ions and lateral asparagine/glutamine zippers stabilize the post-fusion hairpin conformation of the SARS coronavirus spike glycoprotein

International Nuclear Information System (INIS)

Duquerroy, Stephane; Vigouroux, Armelle; Rottier, Peter J.M.; Rey, Felix A.; Jan Bosch, Berend

2005-01-01

The coronavirus spike glycoprotein is a class I membrane fusion protein with two characteristic heptad repeat regions (HR1 and HR2) in its ectodomain. Here, we report the X-ray structure of a previously characterized HR1/HR2 complex of the severe acute respiratory syndrome coronavirus spike protein. As expected, the HR1 and HR2 segments are organized in antiparallel orientations within a rod-like molecule. The HR1 helices form an exceptionally long (120 A) internal coiled coil stabilized by hydrophobic and polar interactions. A striking arrangement of conserved asparagine and glutamine residues of HR1 propagates from two central chloride ions, providing hydrogen-bonding 'zippers' that strongly constrain the path of the HR2 main chain, forcing it to adopt an extended conformation at either end of a short HR2 α-helix

Glutamine synthetase activity and glutamate uptake in hippocampus and frontal cortex in portal hypertensive rats

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Acosta, Gabriela Beatriz; Fernández, María Alejandra; Roselló, Diego Martín; Tomaro, María Luján; Balestrasse, Karina; Lemberg, Abraham

2009-01-01

AIM: To study glutamine synthetase (GS) activity and glutamate uptake in the hippocampus and frontal cortex (FC) from rats with prehepatic portal vein hypertension. METHODS: Male Wistar rats were divided into sham-operated group and a portal hypertension (PH) group with a regulated stricture of the portal vein. Animals were sacrificed by decapitation 14 d after portal vein stricture. GS activity was determined in the hippocampus and FC. Specific uptake of radiolabeled L-glutamate was studied using synaptosome-enriched fractions that were freshly prepared from both brain areas. RESULTS: We observed that the activity of GS increased in the hippocampus of PH rats, as compared to control animals, and decreased in the FC. A significant decrease in glutamate uptake was found in both brain areas, and was more marked in the hippocampus. The decrease in glutamate uptake might have been caused by a deficient transport function, significantly and persistent increase in this excitatory neurotransmitter activity. CONCLUSION: The presence of moderate ammonia blood levels may add to the toxicity of excitotoxic glutamate in the brain, which causes alterations in brain function. Portal vein stricture that causes portal hypertension modifies the normal function in some brain regions. PMID:19533812

Chemical stability of insulin. 1. Hydrolytic degradation during storage of pharmaceutical preparations.

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Brange, J; Langkjaer, L; Havelund, S; Vølund, A

1992-06-01

Hydrolysis of insulin has been studied during storage of various preparations at different temperatures. Insulin deteriorates rapidly in acid solutions due to extensive deamidation at residue AsnA21. In neutral formulations deamidation takes place at residue AsnB3 at a substantially reduced rate under formation of a mixture of isoAsp and Asp derivatives. The rate of hydrolysis at B3 is independent of the strength of the preparation, and in most cases the species of insulin, but varies with storage temperature and formulation. Total transformation at B3 is considerably reduced when insulin is in the crystalline as compared to the amorphous or soluble state, indicating that formation of the rate-limiting cyclic imide decreases when the flexibility of the tertiary structure is reduced. Neutral solutions containing phenol showed reduced deamidation probably because of a stabilizing effect of phenol on the tertiary structure (alpha-helix formation) around the deamidating residue, resulting in a reduced probability for formation of the intermediate imide. The ratio of isoAsp/Asp derivative was independent of time and temperature, suggesting a pathway involving only intermediate imide formation, without any direct side-chain hydrolysis. However, increasing formation of Asp relative to isoAsp derivative was observed with decreasing flexibility of the insulin three-dimensional structure in the formulation. In certain crystalline suspensions a cleavage of the peptide bond A8-A9 was observed. Formation of this split product is species dependent: bovine greater than porcine greater than human insulin. The hydrolytic cleavage of the peptide backbone takes place only in preparations containing rhombohedral crystals in addition to free zinc ions.

Chemical stability of insulin. 4. Mechanisms and kinetics of chemical transformations in pharmaceutical formulation.

Science.gov (United States)

Brange, J

1992-01-01

Insulin decomposes by a multitude of chemical reactions [1-3]. It deamidates at two different residues by entirely different mechanisms. In acid, deamidation at AsnA21 is intramolecularly catalyzed by the protonated C-terminal, whereas above pH 6 an intermediate imide formation at residue AsnB3 leads to isoAsp and Asp derivatives. The imide formation requires a large rotation around the alpha-carbon/peptide carbonyl carbon bond at B3, corresponding to a 10 A movement of the B-chain N-terminal. The main determinant for the rate of B3 deamidation, as well as for the ratio between the two products formed, is the local conformational structure, which is highly influenced by various excipients and the physical state of the insulin. An amazing thermolysin-like, autoproteolytic cleavage of the A-chain takes place in rhombohedral insulin crystals, mediated by a concerted catalytic action by several, inter-hexameric functional groups and Zn2+. Intermolecular, covalent cross-linking of insulin molecules occurs via several mechanisms. The most prominent type of mechanism is aminolysis by the N-terminals, leading to isopeptide linkages with the A-chain side-chain amides of residues GlnA15, AsnA18 and AsnA21. The same type of reaction also leads to covalent cross-linking of the N-terminal in protamine with insulin. Disulfide exchange reactions, initiated by lysis of the A7-B7 disulfide bridge, lead mainly to formation of covalent oligo- and polymers. Activation energy (Ea) for the neutral deamidation and the aminolysis reactions was found to be 80 and 119 KJ/mol, respectively.

Glassy-state stabilization of a dominant negative inhibitor anthrax vaccine containing aluminum hydroxide and glycopyranoside lipid A adjuvants.

Science.gov (United States)

Hassett, Kimberly J; Vance, David J; Jain, Nishant K; Sahni, Neha; Rabia, Lilia A; Cousins, Megan C; Joshi, Sangeeta; Volkin, David B; Middaugh, C Russell; Mantis, Nicholas J; Carpenter, John F; Randolph, Theodore W

2015-02-01

During transport and storage, vaccines may be exposed to temperatures outside of the range recommended for storage, potentially causing efficacy losses. To better understand and prevent such losses, dominant negative inhibitor (DNI), a recombinant protein antigen for a candidate vaccine against anthrax, was formulated as a liquid and as a glassy lyophilized powder with the adjuvants aluminum hydroxide and glycopyranoside lipid A (GLA). Freeze-thawing of the liquid vaccine caused the adjuvants to aggregate and decreased its immunogenicity in mice. Immunogenicity of liquid vaccines also decreased when stored at 40°C for 8 weeks, as measured by decreases in neutralizing antibody titers in vaccinated mice. Concomitant with efficacy losses at elevated temperatures, changes in DNI structure were detected by fluorescence spectroscopy and increased deamidation was observed by capillary isoelectric focusing (cIEF) after only 1 week of storage of the liquid formulation at 40°C. In contrast, upon lyophilization, no additional deamidation after 4 weeks at 40°C and no detectable changes in DNI structure or reduction in immunogenicity after 16 weeks at 40°C were observed. Vaccines containing aluminum hydroxide and GLA elicited higher immune responses than vaccines adjuvanted with only aluminum hydroxide, with more mice responding to a single dose. © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association.

Arginine Deprivation Inhibits the Warburg Effect and Upregulates Glutamine Anaplerosis and Serine Biosynthesis in ASS1-Deficient Cancers

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Jeff Charles Kremer

2017-01-01

Full Text Available Targeting defects in metabolism is an underutilized strategy for the treatment of cancer. Arginine auxotrophy resulting from the silencing of argininosuccinate synthetase 1 (ASS1 is a common metabolic alteration reported in a broad range of aggressive cancers. To assess the metabolic effects that arise from acute and chronic arginine starvation in ASS1-deficient cell lines, we performed metabolite profiling. We found that pharmacologically induced arginine depletion causes increased serine biosynthesis, glutamine anaplerosis, oxidative phosphorylation, and decreased aerobic glycolysis, effectively inhibiting the Warburg effect. The reduction of glycolysis in cells otherwise dependent on aerobic glycolysis is correlated with reduced PKM2 expression and phosphorylation and upregulation of PHGDH. Concurrent arginine deprivation and glutaminase inhibition was found to be synthetic lethal across a spectrum of ASS1-deficient tumor cell lines and is sufficient to cause in vivo tumor regression in mice. These results identify two synthetic lethal therapeutic strategies exploiting metabolic vulnerabilities of ASS1-negative cancers.

Molecular evolution of glutamine synthetase II: Phylogenetic evidence of a non-endosymbiotic gene transfer event early in plant evolution

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Tartar Aurélien

2010-06-01

Full Text Available Abstract Background Glutamine synthetase (GS is essential for ammonium assimilation and the biosynthesis of glutamine. The three GS gene families (GSI, GSII, and GSIII are represented in both prokaryotic and eukaryotic organisms. In this study, we examined the evolutionary relationship of GSII from eubacterial and eukaryotic lineages and present robust phylogenetic evidence that GSII was transferred from γ-Proteobacteria (Eubacteria to the Chloroplastida. Results GSII sequences were isolated from four species of green algae (Trebouxiophyceae, and additional green algal (Chlorophyceae and Prasinophytae and streptophyte (Charales, Desmidiales, Bryophyta, Marchantiophyta, Lycopodiophyta and Tracheophyta sequences were obtained from public databases. In Bayesian and maximum likelihood analyses, eubacterial (GSIIB and eukaryotic (GSIIE GSII sequences formed distinct clades. Both GSIIB and GSIIE were found in chlorophytes and early-diverging streptophytes. The GSIIB enzymes from these groups formed a well-supported sister clade with the γ-Proteobacteria, providing evidence that GSIIB in the Chloroplastida arose by horizontal gene transfer (HGT. Bayesian relaxed molecular clock analyses suggest that GSIIB and GSIIE coexisted for an extended period of time but it is unclear whether the proposed HGT happened prior to or after the divergence of the primary endosymbiotic lineages (the Archaeplastida. However, GSIIB genes have not been identified in glaucophytes or red algae, favoring the hypothesis that GSIIB was gained after the divergence of the primary endosymbiotic lineages. Duplicate copies of the GSIIB gene were present in Chlamydomonas reinhardtii, Volvox carteri f. nagariensis, and Physcomitrella patens. Both GSIIB proteins in C. reinhardtii and V. carteri f. nagariensis had N-terminal transit sequences, indicating they are targeted to the chloroplast or mitochondrion. In contrast, GSIIB proteins of P. patens lacked transit sequences, suggesting

Kynurenine aminotransferase III and glutamine transaminase L are identical enzymes that have cysteine S-conjugate β-lyase activity and can transaminate L-selenomethionine.

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Pinto, John T; Krasnikov, Boris F; Alcutt, Steven; Jones, Melanie E; Dorai, Thambi; Villar, Maria T; Artigues, Antonio; Li, Jianyong; Cooper, Arthur J L

2014-11-07

Three of the four kynurenine aminotransferases (KAT I, II, and IV) that synthesize kynurenic acid, a neuromodulator, are identical to glutamine transaminase K (GTK), α-aminoadipate aminotransferase, and mitochondrial aspartate aminotransferase, respectively. GTK/KAT I and aspartate aminotransferase/KAT IV possess cysteine S-conjugate β-lyase activity. The gene for the former enzyme, GTK/KAT I, is listed in mammalian genome data banks as CCBL1 (cysteine conjugate beta-lyase 1). Also listed, despite the fact that no β-lyase activity has been assigned to the encoded protein in the genome data bank, is a CCBL2 (synonym KAT III). We show that human KAT III/CCBL2 possesses cysteine S-conjugate β-lyase activity, as does mouse KAT II. Thus, depending on the nature of the substrate, all four KATs possess cysteine S-conjugate β-lyase activity. These present studies show that KAT III and glutamine transaminase L are identical enzymes. This report also shows that KAT I, II, and III differ in their ability to transaminate methyl-L-selenocysteine (MSC) and L-selenomethionine (SM) to β-methylselenopyruvate (MSP) and α-ketomethylselenobutyrate, respectively. Previous studies have identified these seleno-α-keto acids as potent histone deacetylase inhibitors. Methylselenol (CH3SeH), also purported to have chemopreventive properties, is the γ-elimination product of SM and the β-elimination product of MSC catalyzed by cystathionine γ-lyase (γ-cystathionase). KAT I, II, and III, in part, can catalyze β-elimination reactions with MSC generating CH3SeH. Thus, the anticancer efficacy of MSC and SM will depend, in part, on the endogenous expression of various KAT enzymes and cystathionine γ-lyase present in target tissue coupled with the ability of cells to synthesize in situ either CH3SeH and/or seleno-keto acid metabolites. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

Glutamine-containing “turn-on” fluorescence sensor for the highly sensitive and selective detection of chromium (III) ion in water

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Zhao, Meili; Ma, Liguo; Zhang, Min; Cao, Weiguang; Yang, Liting; Ma, Li-Jun

2013-12-01

In this study, we reported a new fluorescence sensor for chromium (III) ion, dansyl-L-glutamine (1). The sensor displayed a unique selective fluorescence “turn-on” response to Cr3+ over other common metal ions in water. Notably, 1 still showed a ratiometric response to Cr3+ in UV-vis absorption spectra. The binding mechanism of 1 to Cr3+ was further clarified by using NMR and ESI-MS spectra. The experiment results indicated that the dual-responses of 1 to Cr3+ should attribute to the coordination of deprotonated sulfonamide group with Cr3+ and the protonation of the dimethylamino group due to the coordination of Cr3+ for 1. In addition, two chloride ions also coordinated to the complex of sensor-chromium (III) ion, which further strengthened the conformation of 1-Cr3+.

Glutamine and glutamic acid supplementation enhances performance of broiler chickens under the hot and humid tropical condition

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Joshua O. Olubodun

2015-02-01

Full Text Available Day-old (day 1 commercial broiler chickens were fed i basal diet (control, ii basal diet +0.5% AminoGut (AG, or iii basal diet +1% AG from 1 to 42 d of age under the hot and humid tropical environment. AminoGut is a commercial dietary supplement containing a mixture of L-glutamine (Gln and L-glutamic (Glu acid. Weight gain and feed conversion ratio during the starter (1 to 21 d and overall (1 to 42 d periods improved linearly and quadratically with AG supplementation when compared to control. Supplementing birds with AG significantly reduced overall mortality rate. At 21 and 42 d of age, intestinal (duodenum and ileum villi height and crypt depth showed both linear and quadratic positive responses to AG supplementation. Intestinal amylase activity increased linearly and quadratically on d 21, and linearly only on d 42. In conclusion, Gln and Glu supplementation was beneficial in improving the growth performance and survivability of broiler chickens under the hot and humid tropical environment.

Fibronectin-integrin signaling is required for L-glutamine's protection against gut injury.

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Stefanie Niederlechner

Full Text Available Extracellular matrix (ECM stabilization and fibronectin (FN-Integrin signaling can mediate cellular protection. L-glutamine (GLN is known to prevent apoptosis after injury. However, it is currently unknown if ECM stabilization and FN-Integrin osmosensing pathways are related to GLN's cell protective mechanism in the intestine.IEC-6 cells were treated with GLN with or without FN siRNA, integrin inhibitor GRGDSP, control peptide GRGESP or ERK1/2 inhibitors PD98059 and UO126 under basal and stressed conditions. Cell survival measured via MTS assay. Phosphorylated and/or total levels of cleaved caspase-3, cleaved PARP, Bax, Bcl-2, heat shock proteins (HSPs, ERK1/2 and transcription factor HSF-1 assessed via Western blotting. Cell size and F-actin morphology quantified by confocal fluorescence microscopy and intracellular GLN concentration by LC-MS/MS.GLN's prevention of FN degradation after hyperthermia attenuated apoptosis. Additionally, inhibition of FN-Integrin interaction by GRGDSP and ERK1/2 kinase inhibition by PD98059 inhibited GLN's protective effect. GRGDSP attenuated GLN-mediated increases in ERK1/2 phosphorylation and HSF-1 levels. PD98059 and GRGDSP also decreased HSP levels after GLN treatment. Finally, GRGDSP attenuated GLN-mediated increases in cell area size and disrupted F-actin assembly, but had no effect on intracellular GLN concentrations.Taken together, this data suggests that prevention of FN degradation and the FN-Integrin signaling play a key role in GLN-mediated cellular protection. GLN's signaling via the FN-Integrin pathway is associated with HSP induction via ERK1/2 and HSF-1 activation leading to reduced apoptosis after gut injury.

Influência da suplementação de glutamina sobre o desempenho e o desenvolvimento de vilos e criptas do intestino delgado de frangos Influence of glutamine supplementation on performance and intestinal villous and crypt development in broiler chickens

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A. Maiorka

2000-10-01

Full Text Available Investigou-se o efeito da suplementação de glutamina na dieta sobre o consumo de ração, ganho de peso e conversão alimentar e sobre a estrutura da mucosa intestinal de frangos. Foram utilizados 320 pintos de corte machos distribuídos em um delineamento inteiramente ao acaso com dois tratamentos e quatro repetições, sendo T1 suplementado com 1% de L-glutamina na dieta e T2 controle. Os índices de desempenho foram analisados aos 7, 21 e 49 dias de idade das aves. Aos 7 e 14 dias de idade oito aves foram sacrificadas para colheita de fragmentos de cada porção do intestino delgado para avaliação da morfometria intestinal em microscopia de luz em sistema analisador de imagens "Video Plan". As variáveis estudadas foram altura dos vilos, profundidade de cripta e relação vilo: cripta. A adição de 1% de glutamina à dieta de frangos não influenciou (P>0,05 o seu desempenho zootécnico. Entretanto, 1% de glutamina na ração foi capaz de alterar (PThis investigation was carried out in order to study the influence of glutamine supplementation in the ration on performance and on the intestinal structure development of broiler chickens. Three hundred and twenty day-old broiler chickens were used in a completely randomized experiment with two treatments and four repetitions, being T1 supplemented with 1% L-glutamine and T2 - control (not supplemented. The performance was evaluated (feed intake, body weight gain and feed conversion at 7, 21 and 49 days of age. At the same ages birds were sacrificed and samples from different parts of the intestine were collected (duodenum, jejunum and ileum to be submitted to morphometric studies under light microscopy using an image analysis system (Video Plan. The variables studied were villous height, crypt depth and villous:crypt ratio. It was demonstrated that 1% glutamine supplementation in the ration did not influence the broiler chicken performance (P>0.05 during the different phases of growth

Conformational Dynamics of apo-GlnBP Revealed by Experimental and Computational Analysis

KAUST Repository

Feng, Yitao

2016-10-13

The glutamine binding protein (GlnBP) binds l-glutamine and cooperates with its cognate transporters during glutamine uptake. Crystal structure analysis has revealed an open and a closed conformation for apo- and holo-GlnBP, respectively. However, the detailed conformational dynamics have remained unclear. Herein, we combined NMR spectroscopy, MD simulations, and single-molecule FRET techniques to decipher the conformational dynamics of apo-GlnBP. The NMR residual dipolar couplings of apo-GlnBP were in good agreement with a MD-derived structure ensemble consisting of four metastable states. The open and closed conformations are the two major states. This four-state model was further validated by smFRET experiments and suggests the conformational selection mechanism in ligand recognition of GlnBP. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

Conformational Dynamics of apo-GlnBP Revealed by Experimental and Computational Analysis

KAUST Repository

Feng, Yitao; Zhang, Lu; Wu, Shaowen; Liu, Zhijun; Gao, Xin; Zhang, Xu; Liu, Maili; Liu, Jianwei; Huang, Xuhui; Wang, Wenning

2016-01-01

The glutamine binding protein (GlnBP) binds l-glutamine and cooperates with its cognate transporters during glutamine uptake. Crystal structure analysis has revealed an open and a closed conformation for apo- and holo-GlnBP, respectively. However, the detailed conformational dynamics have remained unclear. Herein, we combined NMR spectroscopy, MD simulations, and single-molecule FRET techniques to decipher the conformational dynamics of apo-GlnBP. The NMR residual dipolar couplings of apo-GlnBP were in good agreement with a MD-derived structure ensemble consisting of four metastable states. The open and closed conformations are the two major states. This four-state model was further validated by smFRET experiments and suggests the conformational selection mechanism in ligand recognition of GlnBP. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

Data for iTRAQ secretomic analysis of Aspergillus fumigatus in response to different carbon sources

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Sunil S. Adav

2015-06-01

Full Text Available Here, we provide data related to the research article entitled “Quantitative proteomics study of Aspergillus fumigatus secretome revealed deamidation of secretory enzymes” by Adav et al. (J. Proteomics (2015 [1]. Aspergillus sp. plays an important role in lignocellulosic biomass recycling. To explore biomass hydrolyzing enzymes of A. fumigatus, we profiled secretome under different carbon sources such as glucose, cellulose, xylan and starch by high throughput quantitative proteomics using isobaric tags for relative and absolute quantification (iTRAQ. The data presented here represents the detailed comparative abundances of diverse groups of biomass hydrolyzing enzymes including cellulases, hemicellulases, lignin degrading enzymes, and peptidases and proteases; and their post translational modification like deamidation.

Neuronal Cell Death Induced by Mechanical Percussion Trauma in Cultured Neurons is not Preceded by Alterations in Glucose, Lactate and Glutamine Metabolism.

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Jayakumar, A R; Bak, L K; Rama Rao, K V; Waagepetersen, H S; Schousboe, A; Norenberg, M D

2016-02-01

Traumatic brain injury (TBI) is a devastating neurological disorder that usually presents in acute and chronic forms. Brain edema and associated increased intracranial pressure in the early phase following TBI are major consequences of acute trauma. On the other hand, neuronal injury, leading to neurobehavioral and cognitive impairments, that usually develop months to years after single or repetitive episodes of head trauma, are major consequences of chronic TBI. The molecular mechanisms responsible for TBI-induced injury, however, are unclear. Recent studies have suggested that early mitochondrial dysfunction and subsequent energy failure play a role in the pathogenesis of TBI. We therefore examined whether oxidative metabolism of (13)C-labeled glucose, lactate or glutamine is altered early following in vitro mechanical percussion-induced trauma (5 atm) to neurons (4-24 h), and whether such events contribute to the development of neuronal injury. Cell viability was assayed using the release of the cytoplasmic enzyme lactate dehydrogenase (LDH), together with fluorescence-based cell staining (calcein and ethidium homodimer-1 for live and dead cells, respectively). Trauma had no effect on the LDH release in neurons from 1 to 18 h. However, a significant increase in LDH release was detected at 24 h after trauma. Similar findings were identified when traumatized neurons were stained with fluorescent markers. Additionally (13)C-labeling of glutamate showed a small, but statistically significant decrease at 14 h after trauma. However, trauma had no effect on the cycling ratio of the TCA cycle at any time-period examined. These findings indicate that trauma does not cause a disturbance in oxidative metabolism of any of the substrates used for neurons. Accordingly, such metabolic disturbance does not appear to contribute to the neuronal death in the early stages following trauma.

Celiac disease: Prevalence, diagnosis, pathogenesis and treatment

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Gujral, Naiyana; Freeman, Hugh J; Thomson, Alan BR

2012-01-01

Celiac disease (CD) is one of the most common diseases, resulting from both environmental (gluten) and genetic factors [human leukocyte antigen (HLA) and non-HLA genes]. The prevalence of CD has been estimated to approximate 0.5%-1% in different parts of the world. However, the population with diabetes, autoimmune disorder or relatives of CD individuals have even higher risk for the development of CD, at least in part, because of shared HLA typing. Gliadin gains access to the basal surface of the epithelium, and interact directly with the immune system, via both trans- and para-cellular routes. From a diagnostic perspective, symptoms may be viewed as either “typical” or “atypical”. In both positive serological screening results suggestive of CD, should lead to small bowel biopsy followed by a favourable clinical and serological response to the gluten-free diet (GFD) to confirm the diagnosis. Positive anti-tissue transglutaminase antibody or anti-endomysial antibody during the clinical course helps to confirm the diagnosis of CD because of their over 99% specificities when small bowel villous atrophy is present on biopsy. Currently, the only treatment available for CD individuals is a strict life-long GFD. A greater understanding of the pathogenesis of CD allows alternative future CD treatments to hydrolyse toxic gliadin peptide, prevent toxic gliadin peptide absorption, blockage of selective deamidation of specific glutamine residues by tissue, restore immune tolerance towards gluten, modulation of immune response to dietary gliadin, and restoration of intestinal architecture. PMID:23155333

Exogenous transglutaminase improves multiple-stress tolerance in Lactococcus lactis and other lactic acid bacteria with glutamine and lysine in the cell wall.

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Li, Yu; Kan, Zhipeng; You, Yuanli; Gao, Xueling; Wang, Zhigeng; Fu, Ruiyan

2015-12-01

To increase the resistance of ingested bacteria to multiple environmental stresses, the role of transglutaminase in Lactococcus lactis and possible mechanisms of action were explored. L. lactis grown with transglutaminase exhibited significantly higher resistance to bile salts, stimulated gastric juice, antibiotics, NaCl, and cold stress compared to the control (cultured without transglutaminase), with no negative influence on cell growth. Transmission electron microscopy revealed that the cell walls of L. lactis cultured with 9 U transglutaminase/ml were approx. 1.9-times thicker than the control. Further analysis demonstrated that the multi-resistant phenotype was strain-specific; that is, it occurred in bacteria with the presence of glutamine and lysine in the peptidoglycan. Supplementation of culture media with transglutaminase is an effective, simple, and inexpensive strategy to protect specific ingested bacteria against multiple environmental challenges.

Engineered, highly reactive substrates of microbial transglutaminase enable protein labeling within various secondary structure elements.

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Rachel, Natalie M; Quaglia, Daniela; Lévesque, Éric; Charette, André B; Pelletier, Joelle N

2017-11-01

Microbial transglutaminase (MTG) is a practical tool to enzymatically form isopeptide bonds between peptide or protein substrates. This natural approach to crosslinking the side-chains of reactive glutamine and lysine residues is solidly rooted in food and textile processing. More recently, MTG's tolerance for various primary amines in lieu of lysine have revealed its potential for site-specific protein labeling with aminated compounds, including fluorophores. Importantly, MTG can label glutamines at accessible positions in the body of a target protein, setting it apart from most labeling enzymes that react exclusively at protein termini. To expand its applicability as a labeling tool, we engineered the B1 domain of Protein G (GB1) to probe the selectivity and enhance the reactivity of MTG toward its glutamine substrate. We built a GB1 library where each variant contained a single glutamine at positions covering all secondary structure elements. The most reactive and selective variants displayed a >100-fold increase in incorporation of a recently developed aminated benzo[a]imidazo[2,1,5-cd]indolizine-type fluorophore, relative to native GB1. None of the variants were destabilized. Our results demonstrate that MTG can react readily with glutamines in α-helical, β-sheet, and unstructured loop elements and does not favor one type of secondary structure. Introducing point mutations within MTG's active site further increased reactivity toward the most reactive substrate variant, I6Q-GB1, enhancing MTG's capacity to fluorescently label an engineered, highly reactive glutamine substrate. This work demonstrates that MTG-reactive glutamines can be readily introduced into a protein domain for fluorescent labeling. © 2017 The Protein Society.

Narrow-spectrum chemoreceptor cells in the walking legs of the lobster Homarus americanus: taste specialists

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Derby, C D; Atema, J

1982-01-01

The chemoreceptors in the legs of lobsters function in the localization and handling of food. By single-unit extracellular recording techniques, the specificity of single primary chemoreceptor cells is described here in detail. In contrast to what is known in vertebrates, narrow-spectrum chemoreceptors of several different types were found, each type responding with maximal sensitivity to only one of the following compounds: L-glutamate, L-glutamine, L-arginine, taurine, betaine, and ammonium chloride. Ammonium chloride sensitive cells were also highly specific. Other groups of narrow-spectrum cells - L-arginine, L-glutamine, taurine, and betaine sensitive chemoreceptors - showed equally strong specificity. These results indicate that the peripheral coding system in the legs of lobsters is based largely but perhaps not exclusively on narrow-spectrum chemoreceptor cells.

Intestinal intraluminal injection of glutamine increases trolox total equivalent antioxidant capacity (TEAC in hepatic ischemia-reperfusion Injeção na luz intestinal de glutamina aumenta a capacidade anti-oxidante total em equivalência ao trolox (TEAC na isquemia-reperfusão hepática

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Alberto Bicudo Salomão

2006-01-01

Full Text Available PURPOSE: To evaluate the effects of intraluminal injection of glutamine on the serum trolox equivalent antioxidant capacity in an experimental model of ischemia-reperfusion of the liver observing the applicability of modifications on the original assay method. METHODS: Thirty Wistar rats underwent laparotomy to perform a 20 cm blind sac of small bowel and occlusion of the hepatic hilo for 30 minutes and reperfusion for 5 minutes. Into the gut sac it was injected glutamine (glutamine group, n=10 or distilled water (control group, n=10. Ten other animals (sham group underwent laparotomy without artery occlusion. Blood samples were collected for trolox equivalent antioxidant capacity assays in different temperature conditions, reagent quantities and time for spectrophotometer readings. RESULTS: Total antioxidant capacity was significantly greater in glutamine group than in both control group (1,60[1,55-1,77] vs 1,44[1,27-1,53] and sham group (1,60[1,55-1,77] vs 1,48[1,45-1,59]. CONCLUSION: Glutamine enhanced serum antioxidant capacity. The assay technique consistently reflected the changes in the antioxidant defenses in this experimental model.OBJETIVO: Avaliar em um modelo experimental de isquemia-reperfusão hepática os efeitos da injeção intraluminal de glutamina na capacidade anti-oxidante total em equivalência ao trolox (TEAC do plasma, verificando a aplicabilidade de modificações ao método original de dosagem. MÉTODOS: Trinta ratos Wistar foram submetidos a laparotomia e confecção de uma alça fechada de 20 cm de comprimento envolvendo o intestinal delgado distal seguido do clampeamento do hilo hepático por 30 minutos e reperfusão por 5 minutos. Na alça fechada foi injetada glutamina (grupo glutamina; n=10 ou água destilada (grupo controle; n=10. Em dez animais (grupo sham não foi realizado clampeamento hilar. Coletou-se sangue para dosagem da capacidade antioxidante total em equivalência ao trolox em condições modificadas

Efeito da glutamina sobre o turnover do carbono (δ13C de músculos e vísceras de leitões desmamados: glutamina e turnover de carbono tecidual - DOI: 10.4025/actascianimsci.v30i3.5712 Effect of glutamine on carbon (δ13C turnover in the muscles and viscera of weaned piglets - DOI: 10.4025/actascianimsci.v30i3.5712

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Evandro Tadeu da Silva

2008-11-01

Full Text Available O estudo foi conduzido para verificar a influência da glutamina no turnover do carbono em tecidos de leitões. Nove porcas foram cobertas e receberam dietas compostas predominantemente por grãos de plantas do ciclo fotossintético C4 durante gestação e lactação. Aos 21 dias de idade, 48 leitões foram distribuídos aleatoriamente nos tratamentos: T1 = dieta C3, sem suplementação de glutamina, e T2 = dieta C3, suplementada com 1% de glutamina. Nos dias 0, 1, 2, 3, 4, 5, 8, 11, 15, 20, 29 e 46 pós-desmame, foram abatidos dois leitões/tratamento. Amostras dos músculos Psoas major e Masseter, fígado e pâncreas foram coletadas e analisadas quanto à composição e δ‰13C e mensurada a substituição do carbono em função do tempo. A glutamina acelerou a substituição do carbono em ambos os músculos, como observado pelos valores de meia-vida (T destes tecidos (T = 51,4 e 21,7 dias para Masseter e 31,5 e 20,3 dias para Psoas major, nos tratamentos sem e com suplementação de glutamina, respectivamente. Os valores de meia-vida do carbono das vísceras indicam que esse aminoácido também acelerou o turnover do carbono nestes órgãos. Os resultados indicam estímulo anabólico da glutamina sobre os tecidos avaliados.The study was carried out to verify the influence of glutamine on carbon turnover in the muscles and viscera of piglets. Nine sows were bred and received diets predominantly composed by grains of C4 photosynthetic cycle plants during gestation and lactation. The piglets were weaned at 21 days of age, and 48 animals were distributed at random in two treatments: T1 = C3 diet, without glutamine supplementation; and T2 = C3 diet, supplemented with 1% glutamine. On days 0, 1, 2, 3, 4, 5, 8, 11, 15, 20, 29 and 46 postweaning, two piglets per treatment were slaughtered. Samples of the Psoas major and Masseter muscles, liver and pancreas were collected and analyzed for δ‰13C composition, and carbon turnover was measured as a

Disrupted glutamate-glutamine cycle in acute encephalopathy with biphasic seizures and late reduced diffusion

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Takanashi, Jun-ichi; Terai, Masaru [Tokyo Women' s Medical University Yachiyo Medical Center, Department of Pediatrics, Yachiyo-shi (Japan); Mizuguchi, Masashi [The University of Tokyo, Department of Developmental Medical Sciences, Graduate School of Medicine, Tokyo (Japan); Barkovich, A.J. [University of California San Francisco, Department of Radiology and Biomedical Imaging, San Francisco, CA (United States)

2015-11-15

Acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) is the most common subtype of infectious pediatric encephalopathy in Japan. It is sometimes difficult to make an early diagnosis of AESD; excitotoxicity is postulated to be the pathogenesis based on elevated glutamine (Gln) and glutamate (Glu) complex (Glx = Glu + Gln) observed on MR spectroscopy. It is uncertain whether Gln or Glu contributes to the elevated Glx, or whether MR spectroscopy is useful for an early diagnosis. Five Japanese patients with AESD (three boys and two girls, 1 year of age) were enrolled in this study. MR spectroscopy was acquired from the frontal white matter (repetition time (TR) of 5000 ms, echo time (TE) of 30 ms) with a 1.5- or 3.0-T scanner. MR spectroscopy was performed four times for two patients, three times for one patient, and two times for two patients. Quantification of Glu and Gln was performed using LCModel. Glu was elevated in three of four studies on days 1-4 and became normal or low afterward. Gln was normal in three studies on days 1-2, elevated in all seven studies on days 4-12, and became normal or low afterward. These findings suggest that MR spectroscopy may be useful for an early diagnosis. Acute Glu elevation changes to subacute Gln elevation, suggesting that a disrupted Glu-Gln cycle may play an important role. (orig.)

Chemically modified carboxypeptidase Y with increased amidase activity

International Nuclear Information System (INIS)

Breddam, K.

1984-01-01

Treatment of carboxypeptidase Y with 14 C-iodoacetamide caused a drastic reduction in the peptidase activity towards FA-Phe-Leu-OH while the esterase activity towards FA-Phe-OMe, the amidase activity towards FA-Phe-NH 2 and the peptidyl amino acid amide hydrolase activity towards FA-Phe-Gly-NH 2 were much less affected. The loss of peptidase activity could be correlated with the incorporation of a single equivalent of reagent and it was demonstrated that the site of reaction was a methionyl residue, thus forming a sulfonium derivative. Analogous methionyl modifications were performed: carboxypeptidase Y modified with phenacylbromide hydrolysed substrates with bulky leaving groups in the P position, i.e. -OEt, -OBzl, -Gly-NH 2 ,-Gly-OH, and -Leu-OH, at reduced rates while substrates with small groups in that position, i.e. -OMe and -NH 2 , were hydrolysed with increased rates. These results indicate that the methionyl residue modified by phenacylbromide is located in the S binding site of the enzyme. Similar results were obtained with carboxypeptidase Y modified with m-nitrophen- acylbromide and p-nitrophenacylbromide. The increase in amidase activity and decrease in peptidyl amino acid amide hydrolase activity of carboxypeptidase Y following modification with phenacylbromide, m-nitrophenacylbromide, and p-nitrophenacylbromide was exploited in deamidation of peptide amides. These modified enzymes deamidated peptide amides with the exception of those containing a C-terminal glycyl or seryl residue in yields of 80-100% which is significantly higher than with unmodified carboxypeptidase Y. (author)

Glutamate/glutamine concentrations in the dorsal anterior cingulate vary with Post-Traumatic Stress Disorder symptoms.

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Harnett, Nathaniel G; Wood, Kimberly H; Ference, Edward W; Reid, Meredith A; Lahti, Adrienne C; Knight, Amy J; Knight, David C

2017-08-01

Trauma and stress-related disorders (e.g., Acute Stress Disorder; ASD and Post-Traumatic Stress Disorder; PTSD) that develop following a traumatic event are characterized by cognitive-affective dysfunction. The cognitive and affective functions disrupted by stress disorder are mediated, in part, by glutamatergic neural systems. However, it remains unclear whether neural glutamate concentrations, measured acutely following trauma, vary with ASD symptoms and/or future PTSD symptom expression. Therefore, the current study utilized proton magnetic resonance spectroscopy ( 1 H-MRS) to investigate glutamate/glutamine (Glx) concentrations within the dorsal anterior cingulate cortex (ACC) of recently (i.e., within one month) traumatized individuals and non-traumatized controls. Although Glx concentrations within dorsal ACC did not differ between recently traumatized and non-traumatized control groups, a positive linear relationship was observed between Glx concentrations and current stress disorder symptoms in traumatized individuals. Further, Glx concentrations showed a positive linear relationship with future stress disorder symptoms (i.e., assessed 3 months post-trauma). The present results suggest glutamate concentrations may play a role in both acute and future post-traumatic stress symptoms following a traumatic experience. The current results expand our understanding of the neurobiology of stress disorder and suggest glutamate within the dorsal ACC plays an important role in cognitive-affective dysfunction following a traumatic experience. Copyright © 2017 Elsevier Ltd. All rights reserved.

Origins of domestication and polyploidy in oca (Oxalis Tuberosa: Oxalidaceae). 2. Chloroplast-expressed glutamine synthetase data.

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Emshwiller, Eve; Doyle, Jeff J

2002-07-01

In continuing study of the origins of the octoploid tuber crop oca, Oxalis tuberosa Molina, we used phylogenetic analysis of DNA sequences of the chloroplast-active (nuclear encoded) isozyme of glutamine synthetase (ncpGS) from cultivated oca, its allies in the "Oxalis tuberosa alliance," and other Andean Oxalis. Multiple ncpGS sequences found within individuals of both the cultigen and a yet unnamed wild tuber-bearing taxon of Bolivia were separated by molecular cloning, but some cloned sequences appeared to be artifacts of polymerase chain reaction (PCR) recombination and/or Taq error. Nonetheless, three classes of nonrecombinant sequences each joined a different part of the O. tuberosa alliance clade on the ncpGS gene tree. Octoploid oca shares two sequence classes with the Bolivian tuber-bearing taxon (of unknown ploidy level). Fixed heterozygosity of these two sequence classes in all ocas sampled suggests that they represent homeologous loci and that oca is allopolyploid. A third sequence class, found in eight of nine oca plants sampled, might represent a third homeologous locus, suggesting that oca may be autoallopolyploid, and is shared with another wild tuber-bearing species, tetraploid O. picchensis of southern Peru. Thus, ncpGS data identify these two taxa as the best candidates as progenitors of cultivated oca.

Glutamine's protection against cellular injury is dependent on heat shock factor-1.

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Morrison, Angela L; Dinges, Martin; Singleton, Kristen D; Odoms, Kelli; Wong, Hector R; Wischmeyer, Paul E

2006-06-01

Glutamine (GLN) has been shown to protect cells, tissues, and whole organisms from stress and injury. Enhanced expression of heat shock protein (HSP) has been hypothesized to be responsible for this protection. To date, there are no clear mechanistic data confirming this relationship. This study tested the hypothesis that GLN-mediated activation of the HSP pathway via heat shock factor-1 (HSF-1) is responsible for cellular protection. Wild-type HSF-1 (HSF-1(+/+)) and knockout (HSF-1(-/-)) mouse fibroblasts were used in all experiments. Cells were treated with GLN concentrations ranging from 0 to 16 mM and exposed to heat stress injury in a concurrent treatment model. Cell viability was assayed with phenazine methosulfate plus tetrazolium salt, HSP-70, HSP-25, and nuclear HSF-1 expression via Western blot analysis, and HSF-1/heat shock element (HSE) binding via EMSA. GLN significantly attenuated heat-stress induced cell death in HSF-1(+/+) cells in a dose-dependent manner; however, the survival benefit of GLN was lost in HSF-1(-/-) cells. GLN led to a dose-dependent increase in HSP-70 and HSP-25 expression after heat stress. No inducible HSP expression was observed in HSF-1(-/-) cells. GLN increased unphosphorylated HSF-1 in the nucleus before heat stress. This was accompanied by a GLN-mediated increase in HSF-1/HSE binding and nuclear content of phosphorylated HSF-1 after heat stress. This is the first demonstration that GLN-mediated cellular protection after heat-stress injury is related to HSF-1 expression and cellular capacity to activate an HSP response. Furthermore, the mechanism of GLN-mediated protection against injury appears to involve an increase in nuclear HSF-1 content before stress and increased HSF-1 promoter binding and phosphorylation.

Differences in the roles of a glutamine amidotransferase subunit of pyridoxal 5'-phosphate synthase between Bacillus circulans and Bacillus subtilis.

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Itagaki, Shiori; Haga, Minami; Oikawa, Yuji; Sakoda, Ayaka; Ohke, Yoshie; Sawada, Hiroshi; Eguchi, Tadashi; Tamegai, Hideyuki

2013-01-01

BtrC2 of the butirosin producer Bacillus circulans is a non-catalytic subunit of 2-deoxy-scyllo-inosose (DOI) synthase that is involved in butirosin biosynthesis, and also a homolog of glutamine amidotransferase subunit (PdxT) of pyridoxal 5'-phosphate (PLP) synthase of Bacillus subtilis. BtrC2 has been found to have functions in B. circulans both in primary and secondary metabolism. In this study, we investigated the properties of PdxT of B. subtilis in order to determine whether the property of enzyme stabilization is universal among PdxT homologs. Complementation with PdxT in the btrC2 disruptant of B. circulans restored the growth and short-term production of antibiotics, but long-term production of antibiotics cannot be restored. Additionally, PdxT did not bind physically with or stabilize BtrC. Our results indicate that the function of BtrC2 in secondary metabolism is specific properties, not universal among PdxT homologs.

Functional specialization of one copy of glutamine phosphoribosyl pyrophosphate amidotransferase in ureide production from symbiotically fixed nitrogen in Phaseolus vulgaris.

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Coleto, Inmaculada; Trenas, Almudena T; Erban, Alexander; Kopka, Joachim; Pineda, Manuel; Alamillo, Josefa M

2016-08-01

Purines are essential molecules formed in a highly regulated pathway in all organisms. In tropical legumes, the nitrogen fixed in the nodules is used to generate ureides through the oxidation of de novo synthesized purines. Glutamine phosphoribosyl pyrophosphate amidotransferase (PRAT) catalyses the first committed step of de novo purine synthesis. In Phaseolus vulgaris there are three genes coding for PRAT. The three full-length sequences, which are intron-less genes, were cloned, and their expression levels were determined under conditions that affect the synthesis of purines. One of the three genes, PvPRAT3, is highly expressed in nodules and protein amount and enzymatic activity in these tissues correlate with nitrogen fixation activity. Inhibition of PvPRAT3 gene expression by RNAi-silencing and subsequent metabolomic analysis of the transformed roots shows that PvPRAT3 is essential for the synthesis of ureides in P. vulgaris nodules. © 2016 John Wiley & Sons Ltd.

Massive intestinal resection in rats fed up on glutamine: hepatic glycogen content valuation Ressecção intestinal extensa em ratos tratados com oferta oral de glutamina: avaliação do conteúdo hepático de glicogênio

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Ariney Costa de Miranda

2006-03-01

Full Text Available BACKGROUND: Glutamine has been widely used in treatment of small bowel syndrome and its metabolic effects on the small intestine are well known, however, it has been little studied its effects on hepatic metabolism under this condition. AIM: To verify through experimental model, a glutamine based supplemental diet, administered via oral to rats submitted to massive intestinal resection, evaluating weight evolution and hepatic glycogen content. MATERIAL AND METHODS: Male rats, Wistar, were allocated into three groups to undergo enterectomy. Following diets were applied: with glutamine (G group, without glutamine (NG group, and standard diet from the laboratory (R group. All animals had massive small intestine resection including ileocecal valve removal. After 20 days, all animals were sacrificed. The liver was removed to histological analysis by light microscopy. Slides were stained by periodic acid of Schiff with diastasis. RESULTS: All animals lost weight from the beginning to the end of experiment. Comparing weight loss average expressed in percentage, there was no difference statistically significant on this variance. In analyzed groups, the hepatic glycogen content did not differ statistically, in the histological method evaluated. CONCLUSION: Glutamine feeding via oral did not influence weight loss reduction of animal submitted to massive intestinal resection and did not stimulate glycogen synthesis and storage into hepatocytes.RACIONAL: A glutamina tem sido utilizada amplamente no tratamento da síndrome do intestino curto e seus efeitos metabólicos são bem conhecidos no intestino delgado, porém pouco se tem relatado sobre seus efeitos no metabolismo hepático nessa condição. OBJETIVO: Verificar em modelo experimental, o efeito de dieta suplementada com glutamina administrada por via oral, em ratos submetidos a ressecção intestinal extensa, na evolução ponderal e no conteúdo de glicogênio hepático. MATERIAL E MÉTODOS: Ratos

A Transient Upregulation of Glutamine Synthetase in the Dentate Gyrus Is Involved in Epileptogenesis Induced by Amygdala Kindling in the Rat.

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Hong-Liu Sun

Full Text Available Reduction of glutamine synthetase (GS function is closely related to established epilepsy, but little is known regarding its role in epileptogenesis. The present study aimed to elucidate the functional changes of GS in the brain and its involvement in epileptogenesis using the amygdala kindling model of epilepsy induced by daily electrical stimulation of basolateral amygdala in rats. Both expression and activity of GS in the ipsilateral dentate gyrus (DG were upregulated when kindled seizures progressed to stage 4. A single dose of L-methionine sulfoximine (MSO, in 2 µl, a selective GS inhibitor, was administered into the ipsilateral DG on the third day following the first stage 3 seizure (just before GS was upregulated. It was found that low doses of MSO (5 or 10 µg significantly and dose-dependently reduced the severity of and susceptibility to evoked seizures, whereas MSO at a high dose (20 µg aggravated kindled seizures. In animals that seizure acquisition had been successfully suppressed with 10 µg MSO, GS upregulation reoccurred when seizures re-progressed to stage 4 and re-administration of 10 µg MSO consistently reduced the seizures. GLN at a dose of 1.5 µg abolished the alleviative effect of 10 µg MSO and deleterious effect of 20 µg MSO on kindled seizures. Moreover, appropriate artificial microRNA interference (1 and 1.5×10(6 TU/2 µl of GS expression in the ipsilateral DG also inhibited seizure progression. In addition, a transient increase of GS expression and activity in the cortex was also observed during epileptogenesis evoked by pentylenetetrazole kindling. These results strongly suggest that a transient and region-specific upregulation of GS function occurs when epilepsy develops into a certain stage and eventually promotes the process of epileptogenesis. Inhibition of GS to an adequate degree and at an appropriate timing may be a potential therapeutic approach to interrupting epileptogenesis.

Glutamate-glutamine and GABA in brain of normal aged and patients with cognitive impairment.

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Huang, Dandan; Liu, Dan; Yin, Jianzhong; Qian, Tianyi; Shrestha, Susan; Ni, Hongyan

2017-07-01

To explore the changes of glutamate-glutamine (Glx) and gamma-aminobutyric acid (GABA) in the brain in normal old age and cognitive impairment using magnetic resonance spectroscopy (MRS). Seventeen normal young controls (NYC), 15 normal elderly controls (NEC), 21 patients with mild cognitive impairment (MCI) and 17 with Alzheimer disease (AD) patients were included in this study. Glx and GABA+ levels in the anterior cingulate cortex (ACC) and right hippocampus (rHP) were measured by using a MEGA-PRESS sequence. Glx/Cr and GABA+/Cr ratios were compared between NYC and NEC and between the three elderly groups using analysis of covariance (ANCOVA); the tissue fractions of voxels were used as covariates. The relationships between metabolite ratios and cognitive performance were analysed using Spearman correlation coefficients. For NEC and NYC groups, Glx/Cr and GABA+/Cr ratios were lower in NEC in ACC and rHP. For the three elderly groups, Glx/Cr ratio was lower in AD in ACC compared to NEC and MCI; Glx/Cr ratio was lower in AD in rHP compared to NEC. There was no significant decrease for GABA+/Cr ratio. Glx and GABA levels may decrease simultaneously in normal aged, and Glx level decreased predominantly in AD, and it is helpful in the early diagnosis of AD. • Glx and GABA levels may decrease simultaneously in normal aged. • Glx level may decrease predominantly in Alzheimer disease. • The balance in excitatory-inhibitory systems may be broken in AD. • Decreased Glx level may be helpful in early diagnosis of AD.

Efeitos do estresse agudo de contenção, do estresse crônico de natação e da administração de glutamina sobre a liberação de superóxido por macrófagos alveolares de ratos Effects of acute restraint stress, chronic swim stress and glutamine administration on the release of superoxide from alveolar macrophages of rats

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Elizabeth do Nascimento

2007-08-01

Full Text Available OBJETIVO: Avaliar a liberação de ânion superóxido por macrófagos alveolares em ratos submetidos ou não ao estresse agudo, ao exercício físico de natação e à suplementação com glutamina. MÉTODOS: Quarenta e dois ratos machos da linhagem Wistar com idade em torno de 62 (desvio-padrão=3 dias de idade foram divididos em grupos controle, treino, estresse e glutamina. Após a intervenção, macrófagos alveolares foram coletados e estimulados com acetato de formol miristato para a avaliação da liberação de ânion superóxido. RESULTADOS: Em comparação à primeira hora (controle=26,2, desvio-padrão=4,2; treino=28,7, desvio-padrão=5,1; estresse=20,3, desvio-padrão=4,4; glutamina=26,2, desvio-padrão=4,2, houve aumento (pOBJECTIVE: To assess the release of superoxide anion from alveolar macrophages of rats submitted or not to acute restraint stress, forced swimming and glutamine supplementation. METHODS: Forty-two male Wistar rats aging roughly 62 days (standard deviation=3 were randomly divided into four groups: control, training, stress and glutamine. After the intervention, alveolar macrophages were collected and stimulated with phorbol myristate acetate to assess the release of superoxide anion. RESULTS: When compared with the first hour (control=26.2, standard deviation=4.2; training=28.7, standard deviation=5.1; stress=20.3 , standard deviation=4.4; glutamine=26.2, standard deviation=4.2, the release of superoxide increased (p<0.001 in all experimental groups in the second hour (control=38.4, standard deviation=4.9; training=40.7, standard deviation=6.1; stress=30.2, standard deviation=5.6; glutamine=39.2, standard deviation=5.2 of observation. Training and glutamine supplementation did not induce differences in the release of superoxide from alveolar macrophages when compared with the control group. Only the rats submitted to stress showed a reduction in the release of superoxide in both the first (20.3, standard deviation

Increased Glutamate and Homocysteine and Decreased Glutamine Levels in Autism: A Review and Strategies for Future Studies of Amino Acids in Autism

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Ahmad Ghanizadeh

2013-01-01

Full Text Available There are many reports about the significant roles of some amino acids in neurobiology and treatment of autism. This is a critical review of amino acids levels in autism. No published review article about the level of amino acids in autism was found. The levels of glutamate and homocystein are increased in autism while the levels of glutamine and tryptophan are decreased. Findings regarding the plasma levels of taurine and lysine are controversial. The urinary levels of homocysteine and essential amino acids in both the untreated and treated autistic children are significantly less than those in the controls. The current literature suffers from many methodological shortcomings which needed to be considered in future studies. Some of them are age, gender, developmental level, autism symptoms severity, type of autism spectrum disorders, medical comorbidities, intelligent quotient, diet, concomitant medications, body mass index, and technical method of assessment of amino acids.

Increased Glutamate and Homocysteine and Decreased Glutamine Levels in Autism: A Review and Strategies for Future Studies of Amino Acids in Autism

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Ghanizadeh, Ahmad

2013-01-01

There are many reports about the significant roles of some amino acids in neurobiology and treatment of autism. This is a critical review of amino acids levels in autism. No published review article about the level of amino acids in autism was found. The levels of glutamate and homocystein are increased in autism while the levels of glutamine and tryptophan are decreased. Findings regarding the plasma levels of taurine and lysine are controversial. The urinary levels of homocysteine and essential amino acids in both the untreated and treated autistic children are significantly less than those in the controls. The current literature suffers from many methodological shortcomings which needed to be considered in future studies. Some of them are age, gender, developmental level, autism symptoms severity, type of autism spectrum disorders, medical comorbidities, intelligent quotient, diet, concomitant medications, body mass index, and technical method of assessment of amino acids. PMID:24167375

Plant nutritional status modulates glutamine synthetase levels in ripe tomatoes (Solanum lycopersicum cv. Micro-Tom).

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Scarpeci, Telma E; Marro, Martin L; Bortolotti, Santiago; Boggio, Silvana B; Valle, Estela M

2007-02-01

Tomato (Solanum lycopersicum) fruit ripening implies that chloroplastic proteins are degraded and new proteins are synthesized. Supplementary nutrition is frequently required when tomato plants begin to fruit and continues until the end of the plant's life cycle. Ammonium assimilation is crucial in these fruit maturation and ripening processes. Glutamine synthetase (GS; EC 6.3.1.2), the main ammonium-fixing enzyme in plants, could not be detected in red fruits of several tomato varieties when growing under standard nutrition. In this paper, we analyze the influence of the nutritional status on the ammonium assimilation capacity of ripe tomato (cv. Micro-Tom) fruit. For this purpose, GS expression and protein profiles were followed in mature green and red fruits harvested from plants grown under standard or supplemented nutrition. Under standard nutrient regime (weekly supplied with 0.5 x Hoagland solution) GS activity was found in chloroplasts (GS2) of mature green fruits, but it was not detected either in the chromoplasts or in the cytosol of red fruits. When plants were shifted to a supplemented nutritional regime (daily supplied with 0.5 x Hoagland solution), GS was found in red fruits. Also, cytosolic transcripts (gs1) preferentially accumulated in red fruits under high nutrition. These results indicate that mature green Micro-Tom fruits assimilate ammonia through GS2 under standard nutrition, while ripe red fruits accumulate GS1 under high nutrition, probably in order to assimilate the extra N-compounds made available through supplemented nutrition.

Sleep spindles are related to schizotypal personality traits and thalamic glutamine/glutamate in healthy subjects.

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Lustenberger, Caroline; O'Gorman, Ruth L; Pugin, Fiona; Tüshaus, Laura; Wehrle, Flavia; Achermann, Peter; Huber, Reto

2015-03-01

Schizophrenia is a severe mental disorder affecting approximately 1% of the worldwide population. Yet, schizophrenia-like experiences (schizotypy) are very common in the healthy population, indicating a continuum between normal mental functioning and the psychosis found in schizophrenic patients. A continuum between schizotypy and schizophrenia would be supported if they share the same neurobiological origin. Two such neurobiological markers of schizophrenia are: (1) a reduction of sleep spindles (12-15 Hz oscillations during nonrapid eye movement sleep), likely reflecting deficits in thalamo-cortical circuits and (2) increased glutamine and glutamate (Glx) levels in the thalamus. Thus, this study aimed to investigate whether sleep spindles and Glx levels are related to schizotypal personality traits in healthy subjects. Twenty young male subjects underwent 2 all-night sleep electroencephalography recordings (128 electrodes). Sleep spindles were detected automatically. After those 2 nights, thalamic Glx levels were measured by magnetic resonance spectroscopy. Subjects completed a magical ideation scale to assess schizotypy. Sleep spindle density was negatively correlated with magical ideation (r = -.64, P .1). The common relationship of sleep spindle density with schizotypy and thalamic Glx levels indicates a neurobiological overlap between nonclinical schizotypy and schizophrenia. Thus, sleep spindle density and magical ideation may reflect the anatomy and efficiency of the thalamo-cortical system that shows pronounced impairment in patients with schizophrenia. © The Author 2014. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center. All rights reserved. For permissions, please email: journals.permissions@oup.com.

The effects of glutamine/asparagine content on aggregation and heterologous prion induction by yeast prion-like domains.

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Shattuck, Jenifer E; Waechter, Aubrey C; Ross, Eric D

2017-07-04

Prion-like domains are low complexity, intrinsically disordered domains that compositionally resemble yeast prion domains. Many prion-like domains are involved in the formation of either functional or pathogenic protein aggregates. These aggregates range from highly dynamic liquid droplets to highly ordered detergent-insoluble amyloid-like aggregates. To better understand the amino acid sequence features that promote conversion to stable, detergent-insoluble aggregates, we used the prediction algorithm PAPA to identify predicted aggregation-prone prion-like domains with a range of compositions. While almost all of the predicted aggregation-prone domains formed foci when expressed in cells, the ability to form the detergent-insoluble aggregates was highly correlated with glutamine/asparagine (Q/N) content, suggesting that high Q/N content may specifically promote conversion to the amyloid state in vivo. We then used this data set to examine cross-seeding between prion-like proteins. The prion protein Sup35 requires the presence of a second prion, [PIN + ], to efficiently form prions, but this requirement can be circumvented by the expression of various Q/N-rich protein fragments. Interestingly, almost all of the Q/N-rich domains that formed SDS-insoluble aggregates were able to promote prion formation by Sup35, highlighting the highly promiscuous nature of these interactions.

Structural asymmetry of phosphodiesterase-9, potential protonation of a glutamic acid, and role of the invariant glutamine.

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Jing Hou

2011-03-01

Full Text Available PDE9 inhibitors show potential for treatment of diseases such as diabetes. To help with discovery of PDE9 inhibitors, we performed mutagenesis, kinetic, crystallographic, and molecular dynamics analyses on the active site residues of Gln453 and its stabilizing partner Glu406. The crystal structures of the PDE9 Q453E mutant (PDE9Q453E in complex with inhibitors IBMX and (S-BAY73-6691 showed asymmetric binding of the inhibitors in two subunits of the PDE9Q453E dimer and also the significant positional change of the M-loop at the active site. The kinetic analysis of the Q453E and E406A mutants suggested that the invariant glutamine is critical for binding of substrates and inhibitors, but is unlikely to play a key role in the differentiation between substrates of cGMP and cAMP. The molecular dynamics simulations suggest that residue Glu406 may be protonated and may thus explain the hydrogen bond distance between two side chain oxygens of Glu453 and Glu406 in the crystal structure of the PDE9Q453E mutant. The information from these studies may be useful for design of PDE9 inhibitors.

A Modified Bacillus Calmette-Guérin (BCG Vaccine with Reduced Activity of Antioxidants and Glutamine Synthetase Exhibits Enhanced Protection of Mice despite Diminished in Vivo Persistence

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Douglas S. Kernodle

2013-01-01

Full Text Available Early attempts to improve BCG have focused on increasing the expression of prominent antigens and adding recombinant toxins or cytokines to influence antigen presentation. One such modified BCG vaccine candidate has been withdrawn from human clinical trials due to adverse effects. BCG was derived from virulent Mycobacterium bovis and retains much of its capacity for suppressing host immune responses. Accordingly, we have used a different strategy for improving BCG based on reducing its immune suppressive capacity. We made four modifications to BCG Tice to produce 4dBCG and compared it to the parent vaccine in C57Bl/6 mice. The modifications included elimination of the oxidative stress sigma factor SigH, elimination of the SecA2 secretion channel, and reductions in the activity of iron co-factored superoxide dismutase and glutamine synthetase. After IV inoculation of 4dBCG, 95% of vaccine bacilli were eradicated from the spleens of mice within 60 days whereas the titer of BCG Tice was not significantly reduced. Subcutaneous vaccination with 4dBCG produced greater protection than vaccination with BCG against dissemination of an aerosolized challenge of M. tuberculosis to the spleen at 8 weeks post-challenge. At this time, 4dBCG-vaccinated mice also exhibited altered lung histopathology compared to BCG-vaccinated mice and control mice with less well-developed lymphohistiocytic nodules in the lung parenchyma. At 26 weeks post-challenge, 4dBCG-vaccinated mice but not BCG-vaccinated mice had significantly fewer challenge bacilli in the lungs than control mice. In conclusion, despite reduced persistence in mice a modified BCG vaccine with diminished antioxidants and glutamine synthetase is superior to the parent vaccine in conferring protection against M. tuberculosis. The targeting of multiple immune suppressive factors produced by BCG is a promising strategy for simultaneously improving vaccine safety and effectiveness.

The roles of MHC class II genes and post-translational modification in celiac disease.

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Sollid, Ludvig M

2017-08-01

Our increasing understanding of the etiology of celiac disease, previously considered a simple food hypersensitivity disorder caused by an immune response to cereal gluten proteins, challenges established concepts of autoimmunity. HLA is a chief genetic determinant, and certain HLA-DQ allotypes predispose to the disease by presenting posttranslationally modified (deamidated) gluten peptides to CD4 + T cells. The deamidation of gluten peptides is mediated by transglutaminase 2. Strikingly, celiac disease patients generate highly disease-specific autoantibodies to the transglutaminase 2 enzyme. The dual role of transglutaminase 2 in celiac disease is hardly coincidental. This paper reviews the genetic mapping and involvement of MHC class II genes in disease pathogenesis, and discusses the evidence that MHC class II genes, via the involvement of transglutaminase 2, influence the generation of celiac disease-specific autoantibodies.

Glycyl-glutamine in nucleus accumbens reduces ethanol intake in alcohol preferring (P) rats.

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Resch, Garth E; Shridharani, Shyam; Millington, William R; Garris, David R; Simpson, C Wayne

2005-10-05

Opioid peptides and glycyl-glutamine (Gly-Gln) have been implicated in the control of ethanol consumption. A recognized beta-endorphin cleavage product, Gly-Gln, inhibits voluntary alcohol consumption when microinjected into the nucleus accumbens (AcbSh) of P rats. To evaluate the site-specific efficacy of Gly-Gln on ethanol consumption following AcbSh application, ethanol preferring (P) rats were allowed to establish individual baseline ethanol/water consumption utilizing a voluntary self-administration paradigm. Subsequent to baseline ethanol consumption being established, bilateral guide cannulae were stereotaxically implanted +1 mm dorsal to the AcbSh for subsequent Gly-Gln (100 nmol/microl) or saline vehicle (1 microl) injections. Alcohol intake, body weight, and water intake were measured at 24 h post-injection intervals. Unilateral Gly-Gln injections reduced ethanol consumption 35.6% (P < 0.05) from pre-established baseline consumption (6.24 +/- 0.64 g/kg to 4.06 +/- 0.28 g/kg). Bilateral Gly-Gln injections further reduced consumption to 51.9% (6.4 +/- 1.0 g/kg to 3.08 +/- 0.65 g/kg at 24 h (P < 0.01) below established baseline values within 24 h without significant changes in body weight or water consumption. Also, the amino acid constituents of the dipeptide had no influence on ethanol consumption behavior; however, Gly-Gln efficacy was shown to be comparable to central beta-endorphin-(1-27) or intraperitoneal (i.p.) naltrexone-induced suppression of ethanol intake. These data indicate that the AcbSh exhibits a site-specific sensitivity to the suppressive actions of Gly-Gln or beta-endorphin-(1-27) injections that modulate voluntary ethanol consumption in P rats. These findings support the broader concept that select forebrain opioid-responsive neural sites may influence the development or expression of alcohol abuse syndromes in animal models or humans.

L-alanyl-L-glutamine ingestion maintains performance during a competitive basketball game

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Hoffman Jay R

2012-03-01

Full Text Available Abstract Background The purpose of this study was to examine the efficacy of L-alanyl-L-glutamine (AG ingestion on basketball performance, including jump power, reaction time, shooting accuracy and fatigue. Methods Ten women (21.2 ± 1.6 years; height: 177.8 ± 8.7 cm; body mass: 73.5 ± 8.0 kg, all scholarship NCAA Division I basketball players, volunteered for this study. Subjects participated in four trials, each consisting of a 40-min basketball game with controlled time-outs for rehydration. During the first trial (DHY subjects were not allowed to rehydrate, and the total weight lost during the contest was used to determine fluid replenishment during the subsequent three trials. During one trial subjects consumed only water (W, while during the other two trials subjects consumed the AG supplement mixed in water using either a low dose (1 g per 500 ml (AG1 or high dose (2 g per 500 ml (AG2 concentration. All data assessed prior to and following each game were converted into a Δ score (Post results - Pre results. All performance data were then analyzed using a one-way repeated measures analysis of variance. Results During DHY subjects lost 1.72 ± 0.42 kg (2.3% of their body mass. No differences in fluid intake (1.55 ± 0.43 L were seen between rehydration trials. A 12.5% (p = 0.016 difference in basketball shooting performance was noted between DHY and AG1 and an 11.1% (p = 0.029 difference was seen between AG1 and W. Visual reaction time was significantly greater following AG1 (p = 0.014 compared to DHY. Differences (p = 0.045 in fatigue, as determined by player loads, were seen only between AG2 and DHY. No differences were seen in peak or mean vertical jump power during any trial. Conclusion Rehydration with AG appears to maintain basketball skill performance and visual reaction time to a greater extent than water only.

L-alanyl-L-glutamine ingestion maintains performance during a competitive basketball game.

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Hoffman, Jay R; Williams, David R; Emerson, Nadia S; Hoffman, Mattan W; Wells, Adam J; McVeigh, Daniele M; McCormack, William P; Mangine, Gerald T; Gonzalez, Adam M; Fragala, Maren S

2012-03-07

The purpose of this study was to examine the efficacy of L-alanyl-L-glutamine (AG) ingestion on basketball performance, including jump power, reaction time, shooting accuracy and fatigue. Ten women (21.2 ± 1.6 years; height: 177.8 ± 8.7 cm; body mass: 73.5 ± 8.0 kg), all scholarship NCAA Division I basketball players, volunteered for this study. Subjects participated in four trials, each consisting of a 40-min basketball game with controlled time-outs for rehydration. During the first trial (DHY) subjects were not allowed to rehydrate, and the total weight lost during the contest was used to determine fluid replenishment during the subsequent three trials. During one trial subjects consumed only water (W), while during the other two trials subjects consumed the AG supplement mixed in water using either a low dose (1 g per 500 ml) (AG1) or high dose (2 g per 500 ml) (AG2) concentration. All data assessed prior to and following each game were converted into a Δ score (Post results - Pre results). All performance data were then analyzed using a one-way repeated measures analysis of variance. During DHY subjects lost 1.72 ± 0.42 kg (2.3%) of their body mass. No differences in fluid intake (1.55 ± 0.43 L) were seen between rehydration trials. A 12.5% (p = 0.016) difference in basketball shooting performance was noted between DHY and AG1 and an 11.1% (p = 0.029) difference was seen between AG1 and W. Visual reaction time was significantly greater following AG1 (p = 0.014) compared to DHY. Differences (p = 0.045) in fatigue, as determined by player loads, were seen only between AG2 and DHY. No differences were seen in peak or mean vertical jump power during any trial. Rehydration with AG appears to maintain basketball skill performance and visual reaction time to a greater extent than water only.

Characterization of a PEGylated protein therapeutic by ion exchange chromatography with on-line detection by native ESI MS and MS/MS.

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Muneeruddin, K; Bobst, C E; Frenkel, R; Houde, D; Turyan, I; Sosic, Z; Kaltashov, I A

2017-01-16

Detailed profiling of both enzymatic (e.g., glycosylation) and non-enzymatic (e.g., oxidation and deamidation) post-translational modifications (PTMs) is frequently required for the quality assessment of protein-based drugs. Challenging as it is, this task is further complicated for the so-called second-generation biopharmaceuticals, which also contain "designer PTMs" introduced to either enhance their pharmacokinetic profiles (e.g., PEGylated proteins) or endow them with therapeutic activity (e.g., protein-drug conjugates). Such modifications of protein covalent structure can dramatically increase structural heterogeneity, making the very notion of "molecular mass" meaningless, as ions representing different glycoforms of a PEGylated protein may have nearly identical distributions of ionic current as a function of m/z, making their contributions to the mass spectrum impossible to distinguish. In this work we demonstrate that a combination of ion exchange chromatography (IXC) with on-line detection by electrospray ionization mass spectrometry (ESI MS) and methods of ion manipulation in the gas phase (limited charge reduction and collision-induced dissociation) allows meaningful structural information to be obtained on a structurally heterogeneous sample of PEGylated interferon β-1a. IXC profiling of the protein sample gives rise to a convoluted chromatogram with several partially resolved peaks which can represent both deamidation and different glycosylation patterns within the protein, as well as varying extent of PEGylation. Thus, profiling the protein with on-line IXC/ESI/MS/MS allows it to be characterized by providing information on three different types of PTMs (designer, enzymatic and non-enzymatic) within a single protein therapeutic.

L-Glutamine in vitro Modulates some Immunomodulatory Properties of Bone Marrow Mesenchymal Stem Cells.

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Dos Santos, Guilherme Galvão; Hastreiter, Araceli Aparecida; Sartori, Talita; Borelli, Primavera; Fock, Ricardo Ambrósio

2017-08-01

Glutamine (GLUT) is a nonessential amino acid that can become conditionally essential under stress conditions, being able to act in the modulation of the immune responses. Mesenchymal stem cells (MSCs) are known to their capability in the modulation of immune responses through cell-cell contact and by the secretion of soluble factors. Considering that GLUT is an immunonutrient and little is known about the influence of GLUT on the capability of MSCs to modulate immune cells, this work aims to investigate how variations in GLUT concentrations in vitro could affect some immunomodulatory properties of MSCs. In order to evaluate the effects of GLUT on MSCs immunomodulatory properties, cell proliferation rates, the expression of NFκB and STAT-3, and the production of IL-1β, IL-6, IL-10, TGF-β and TNF-α by MSCs were assessed. Based on our findings, GLUT at high doses (10 mM) augmented the proliferation of MSCs and modulated immune responses by decreasing levels of pro-inflammatory cytokines, such as IL-1β and IL-6, and by increasing levels of anti-inflammatory cytokines IL-10 and TGF-β. In addition, MSCs cultured in higher GLUT concentrations (10 mM) expressed lower levels of NF-κB and higher levels of STAT-3. Furthermore, conditioned media from MSCs cultured at higher GLUT concentrations (10 mM) reduced lymphocyte and macrophage proliferation, increased IL-10 production by both cells types, and decreased IFN-γ production by lymphocytes. Overall, this study showed that 10 mM of GLUT is able to modify immunomodulatory properties of MSCs.

Quantitative multivoxel H-1 MR spectroscopy of the brain in children with acute liver failure

NARCIS (Netherlands)

Sijens, Paul E.; Alkefaji, Heyder; Lunsing, Roelineke J.; van Spronsen, Francjan J.; Meiners, Linda C.; Oudkerk, Matthijs; Verkade, Henkjan J.

Acute liver failure (ALF)-related encephalopathy was previously characterized by MR spectroscopy of single voxels containing both grey and white matter brain tissue. Quantitative multivoxel MRS was used here to compare grey and white matter brain tissue concentrations of glutamate/glutamine (Glx)

Interaction of PHM, PHI and 24-glutamine PHI with human VIP receptors from colonic epithelium: comparison with rat intestinal receptors

International Nuclear Information System (INIS)

Laburthe, M.; Couvineau, A.; Rouyer-Fessard, C.; Moroder, L.

1985-01-01

PHM, the human counterpart of porcine Peptide Histidine Isoleucine amide (PHI), is shown to be a VIP agonist with low potency on human VIP receptors located in colonic epithelial cell membranes. Its potency is identical to that of PHI but by 3 orders of magnitude lower than that of VIP itself in inhibiting 125 I-VIP binding and in stimulating adenylate cyclase activity. This contrasts markedly with the behavior of PHI on rat VIP receptors located in intestinal epithelial cell membranes where PHI is a potent agonist with a potency that is 1/5 that of VIP. In another connection, the authors show that 24-glutamine PHI has the same affinity as 24-glutamic acid PHI (the natural peptide) for rat or human VIP receptors. These results indicate that while PHI may exert some physiological function through its interaction with VIP receptors in rodents, its human counterpart PHM is a very poor agonist of VIP in human. Furthermore, they show that the drastic change in position 24 of PHI (neutral versus acid residue) does not affect the activity of PHI, at least on VIP receptors. 21 references, 1 figure

Effect of glutamine-enriched nutritional support on intestinal mucosal barrier function, MMP-2, MMP-9 and immune function in patients with advanced gastric cancer during perioperative chemotherapy.

Science.gov (United States)

Wang, Juan; Li, Yanfen; Qi, Yuanling

2017-09-01

We studied the effects of glutamine-enriched nutritional support on intestinal mucosal barrier, matrix metalloproteinase (MMP)-2, MMP-9 and immune function during perioperative chemotherapy in patients with advanced gastric cancer. The study was conducted on 94 patients with advanced gastric cancer admitted from April 2015 to March 2016. They were randomly divided into observation and control groups, n=47. Control group was given basic nutritional support whereas glutamine-enriched nutritional support was given to patients in observation group. High-performance liquid chromatography was used to measure lactulose and mannitol ratio in urine (L/M) and ELISA was used to measure D-lactate levels before chemotherapy and in the 1st, 2nd and 3rd cycle of chemotherapy. Immunoglobulin level was detected by immune turbidimetry assay, T lymphocyte subsets were determined by flow cytometry after 3 cycles of chemotherapy, MMP-2 and MMP-9 of patients were compared between the two groups. The serious adverse reactions incidence (grade and IV) of patients were observed. To evaluate the life quality of patients, QLQ-C30 was used after 6 months. The levels of L/M and D-lactate in both groups after the first cycle of chemotherapy were significantly higher than that before chemotherapy; they began to decline after the second or third cycle, but were still significantly higher than the levels before chemotherapy (pgroups after 1st, 2nd, 3rd cycle after chemotherapy, L/M and D-lactate levels of patients in the observation group were significantly lower than in the control group (pgroup was significantly lower than control group (pgroup were significantly higher than control group (pnutritional support can effectively protect the intestinal mucosal barrier function in patients with advanced gastric cancer in their perioperative chemotherapy, improve the level of MMP-2 and MMP-9 in patients with advanced gastric cancer, enhance their immune function, reduce the incidence of adverse

Alanyl-glutamine attenuates 5-fluorouracil-induced intestinal mucositis in apolipoprotein E-deficient mice

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C.V. Araújo

2015-06-01

Full Text Available Apolipoprotein E (APOE=gene, apoE=protein is a known factor regulating the inflammatory response that may have regenerative effects during tissue recovery from injury. We investigated whether apoE deficiency reduces the healing effect of alanyl-glutamine (Ala-Gln treatment, a recognized gut-trophic nutrient, during tissue recovery after 5-FU-induced intestinal mucositis. APOE-knockout (APOE-/- and wild-type (APOE+/+ C57BL6J male and female mice (N=86 were given either Ala-Gln (100 mM or phosphate buffered saline (PBS by gavage 3 days before and 5 days after a 5-fluorouracil (5-FU challenge (450 mg/kg, via intraperitoneal injection. Mouse body weight was monitored daily. The 5-FU cytotoxic effect was evaluated by leukometry. Intestinal villus height, villus/crypt ratio, and villin expression were monitored to assess recovery of the intestinal absorptive surface area. Crypt length, mitotic, apoptotic, and necrotic crypt indexes, and quantitative real-time PCR for insulin-like growth factor-1 (IGF-1 and B-cell lymphoma 2 (Bcl-2 intestinal mRNA transcripts were used to evaluate intestinal epithelial cell turnover. 5-FU challenge caused significant weight loss and leukopenia (P<0.001 in both mouse strains, which was not improved by Ala-Gln. Villus blunting, crypt hyperplasia, and reduced villus/crypt ratio (P<0.05 were found in all 5-FU-challenged mice but not in PBS controls. Ala-Gln improved villus/crypt ratio, crypt length and mitotic index in all challenged mice, compared with PBS controls. Ala-Gln improved villus height only in APOE-/- mice. Crypt cell apoptosis and necrotic scores were increased in all mice challenged by 5-FU, compared with untreated controls. Those scores were significantly lower in Ala-Gln-treated APOE+/+ mice than in controls. Bcl-2 and IGF-1 mRNA transcripts were reduced only in the APOE-/--challenged mice. Altogether our findings suggest APOE-independent Ala-Gln regenerative effects after 5-FU challenge.

Alanyl-glutamine attenuates 5-fluorouracil-induced intestinal mucositis in apolipoprotein E-deficient mice

Energy Technology Data Exchange (ETDEWEB)

Araújo, C.V. [Laboratório da Biologia da Cicatrização, Ontogenia e Nutrição de Tecidos, INCT - Instituto de Biomedicina do Semiárido Brasileiro, Faculdade de Medicina, Universidade Federal do Ceará, Fortaleza, CE (Brazil); Lazzarotto, C.R. [Laboratório de Biologia Molecular e do Desenvolvimento, Universidade de Fortaleza, Fortaleza, CE (Brazil); Aquino, C.C.; Figueiredo, I.L.; Costa, T.B.; Oliveira Alves, L.A. de [Laboratório da Biologia da Cicatrização, Ontogenia e Nutrição de Tecidos, INCT - Instituto de Biomedicina do Semiárido Brasileiro, Faculdade de Medicina, Universidade Federal do Ceará, Fortaleza, CE (Brazil); Ribeiro, R.A. [Laboratório da Inflamação e Câncer, INCT - Instituto de Biomedicina do Semiárido Brasileiro, Faculdade de Medicina, Universidade Federal do Ceará, Fortaleza, CE (Brazil); Bertolini, L.R. [Laboratório de Biologia Molecular e do Desenvolvimento, Universidade de Fortaleza, Fortaleza, CE (Brazil); Lima, A.A.M. [Laboratório de Doenças Infecciosas, INCT - Instituto de Biomedicina do Semiárido Brasileiro, Faculdade de Medicina, Universidade Federal do Ceará, Fortaleza, CE (Brazil); Brito, G.A.C. [Laboratório da Inflamação e Câncer, INCT - Instituto de Biomedicina do Semiárido Brasileiro, Faculdade de Medicina, Universidade Federal do Ceará, Fortaleza, CE (Brazil); Oriá, R.B. [Laboratório da Biologia da Cicatrização, Ontogenia e Nutrição de Tecidos, INCT - Instituto de Biomedicina do Semiárido Brasileiro, Faculdade de Medicina, Universidade Federal do Ceará, Fortaleza, CE (Brazil)

2015-04-28

Apolipoprotein E (APOE=gene, apoE=protein) is a known factor regulating the inflammatory response that may have regenerative effects during tissue recovery from injury. We investigated whether apoE deficiency reduces the healing effect of alanyl-glutamine (Ala-Gln) treatment, a recognized gut-trophic nutrient, during tissue recovery after 5-FU-induced intestinal mucositis. APOE-knockout (APOE{sup -/-}) and wild-type (APOE{sup +/+}) C57BL6J male and female mice (N=86) were given either Ala-Gln (100 mM) or phosphate buffered saline (PBS) by gavage 3 days before and 5 days after a 5-fluorouracil (5-FU) challenge (450 mg/kg, via intraperitoneal injection). Mouse body weight was monitored daily. The 5-FU cytotoxic effect was evaluated by leukometry. Intestinal villus height, villus/crypt ratio, and villin expression were monitored to assess recovery of the intestinal absorptive surface area. Crypt length, mitotic, apoptotic, and necrotic crypt indexes, and quantitative real-time PCR for insulin-like growth factor-1 (IGF-1) and B-cell lymphoma 2 (Bcl-2) intestinal mRNA transcripts were used to evaluate intestinal epithelial cell turnover. 5-FU challenge caused significant weight loss and leukopenia (P<0.001) in both mouse strains, which was not improved by Ala-Gln. Villus blunting, crypt hyperplasia, and reduced villus/crypt ratio (P<0.05) were found in all 5-FU-challenged mice but not in PBS controls. Ala-Gln improved villus/crypt ratio, crypt length and mitotic index in all challenged mice, compared with PBS controls. Ala-Gln improved villus height only in APOE{sup -/-} mice. Crypt cell apoptosis and necrotic scores were increased in all mice challenged by 5-FU, compared with untreated controls. Those scores were significantly lower in Ala-Gln-treated APOE{sup +/+} mice than in controls. Bcl-2 and IGF-1 mRNA transcripts were reduced only in the APOE{sup -/-}-challenged mice. Altogether our findings suggest APOE-independent Ala-Gln regenerative effects after 5-FU

Alanyl-glutamine attenuates 5-fluorouracil-induced intestinal mucositis in apolipoprotein E-deficient mice

International Nuclear Information System (INIS)

Araújo, C.V.; Lazzarotto, C.R.; Aquino, C.C.; Figueiredo, I.L.; Costa, T.B.; Oliveira Alves, L.A. de; Ribeiro, R.A.; Bertolini, L.R.; Lima, A.A.M.; Brito, G.A.C.; Oriá, R.B.

2015-01-01

Apolipoprotein E (APOE=gene, apoE=protein) is a known factor regulating the inflammatory response that may have regenerative effects during tissue recovery from injury. We investigated whether apoE deficiency reduces the healing effect of alanyl-glutamine (Ala-Gln) treatment, a recognized gut-trophic nutrient, during tissue recovery after 5-FU-induced intestinal mucositis. APOE-knockout (APOE -/- ) and wild-type (APOE +/+ ) C57BL6J male and female mice (N=86) were given either Ala-Gln (100 mM) or phosphate buffered saline (PBS) by gavage 3 days before and 5 days after a 5-fluorouracil (5-FU) challenge (450 mg/kg, via intraperitoneal injection). Mouse body weight was monitored daily. The 5-FU cytotoxic effect was evaluated by leukometry. Intestinal villus height, villus/crypt ratio, and villin expression were monitored to assess recovery of the intestinal absorptive surface area. Crypt length, mitotic, apoptotic, and necrotic crypt indexes, and quantitative real-time PCR for insulin-like growth factor-1 (IGF-1) and B-cell lymphoma 2 (Bcl-2) intestinal mRNA transcripts were used to evaluate intestinal epithelial cell turnover. 5-FU challenge caused significant weight loss and leukopenia (P<0.001) in both mouse strains, which was not improved by Ala-Gln. Villus blunting, crypt hyperplasia, and reduced villus/crypt ratio (P<0.05) were found in all 5-FU-challenged mice but not in PBS controls. Ala-Gln improved villus/crypt ratio, crypt length and mitotic index in all challenged mice, compared with PBS controls. Ala-Gln improved villus height only in APOE -/- mice. Crypt cell apoptosis and necrotic scores were increased in all mice challenged by 5-FU, compared with untreated controls. Those scores were significantly lower in Ala-Gln-treated APOE +/+ mice than in controls. Bcl-2 and IGF-1 mRNA transcripts were reduced only in the APOE -/- -challenged mice. Altogether our findings suggest APOE-independent Ala-Gln regenerative effects after 5-FU challenge

Repercussões da L-alanil-glutamina sobre as concentrações de lactato e lactato desidrogenase (LDH em pacientes com isquemia crítica dos membros inferiores submetidos a revascularização distal Repercussions of l-alanyl-glutamine upon the concentrations of lactate and lactate dehydrogenase (LDH in patients with critical ischemia of lower limbs subjected to distal revascularization

Directory of Open Access Journals (Sweden)

Wellington Forte Alves

2003-06-01

Full Text Available OBJETIVO: Investigar efeitos da L-alanil-glutamina nas concentrações musculares de lactato, e nas concentrações sanguíneas de LDH, em pacientes com isquemia crítica dos membros inferiores submetidos à revascularização distal. MÉTODOS: Dezesseis adultos (12-homens/4-mulheres foram distribuídos em 2 grupos (1-controle/2-estudo. Três horas após injeção endovenosa de 250 ml de L-alanil-glutamina a 20% adicionados a 750 ml de soro fisiológico (Grupo 2, ou 1000 ml de solução salina (Grupo 1, iniciava-se a revascularização, sob raquianestesia. Amostras musculares e de sangue (arterial/venoso foram coletadas no início do procedimento (TI, no final (TF, e 10 e 20 minutos após isquemia (T1/T2. RESULTADOS: Observou-se redução significante (pPURPOSE: Investigate the repercussions of L-alanyl-glutamine in muscular tissue concentrations of lactate, and venous and arterial blood concentrations of LDH, in patients with critical ischemia of the lower limbs submitted to distal revascularization. METHODS: Sixteen adults (12 male/4 female were distributed in 2 groups (1-Control/2-Experiment. Three hours after the intravenous injection of 250 ml of a 20% solution of L-alanyl-glutamine added to 750 ml of saline solution (Group 2; or 1000 ml of saline solution (Group 1, distal bypass was carried out under spinal anesthesia. Muscle and blood samples (arterial/venous were collected at the beginning of the surgical procedure (TI, at the end (TF, and 10 and 20 minutes after re-establishment of blood flow. RESULTS: Significant reduction (p<0,05 of lactate concentration was observed in healthy muscle tissue in L-alanyl-glutamine treated patients in comparison to control group, at all times studied. There was a significant reduction (p <0,05 in venous concentrations of LDH in treated patients at all times studied (TI/TFV/T1V/T2V; and in arterial blood during reperfusion (T1A/T2A. CONCLUSIONS: 1. Decreased lactate concentrations in healthy skeletal

Muscle free amino acid profiles are related to differences in skeletal muscle growth between single and twin ovine fetuses near term.

Science.gov (United States)

Sales, Francisco; Pacheco, David; Blair, Hugh; Kenyon, Paul; McCoard, Sue

2013-01-01

Twin sheep fetuses have reduced skeletal muscle weight near birth relative to singles as a result of restricted muscle hypertrophy. Intracellular free amino acids (FAA) are reported to regulate metabolic pathways which control muscle protein accretion, whereby reduced intracellular content of specific FAA may reduce their activation and therefore, muscle hypertrophy. The aim of this study was to determine whether differences in muscle weight between singleton and twin fetuses, under different maternal conditions is associated with reduced concentration of specific FAA. The FAA content in the semitendinosus muscle (ST) in singleton and twin fetuses (rank) at 140 days of gestation from heavy (H) or light (L) ewes fed ad libitum (A) or maintenance (M) level of nutrition was measured. Muscle weight was reduced in twin fetuses compared to singletons in all groups. Reduced concentrations of leucine, threonine and valine, but higher concentrations of methionine, ornithine, lysine and serine were found in twin fetuses compared to singletons. Maternal size and nutrition interaction with rank resulted in reduced glutamine in twins from HM-ewes (H-ewes under M nutrition) compared to their singleton counterparts. Maternal weight interaction with pregnancy rank reduced the concentration of arginine in twins, with a larger effect on H-ewes compared with L-ewes. Maternal size interaction with pregnancy rank resulted in twins from M-ewes to have lower alanine, while twins from A-ewes had lower aspartic acid concentration compared to singletons. The ST muscle weight was positively correlated only with arginine concentration after taking into account rank, size and nutrition. The present results indicate that reduced concentrations of specific intracellular FAA, such as arginine, leucine, valine, glutamine, which are known to play a role in muscle growth, could be acting as limiting factors for muscle hypertrophy in twin fetuses during late gestation. Ewe size and nutrition can

A single mutation in the E2 glycoprotein important for neurovirulence influences binding of Sindbis virus to neuroblastoma cells

NARCIS (Netherlands)

Lee, PY; Knight, R; Smit, JM; Wilschut, J; Griffin, DE

The amino acid at position 55 of the E2 glycoprotein (E2(55)) of Sindbis virus (SV) is a critical determinant of SV neurovirulence in mice. Recombinant virus strain TE (E2(55) = histidine) differs only at this position from virus strain 633 (E2(55) = glutamine), yet TE is considerably more

Efeito da suplementação de glutamina sobre variáveis hematológicas e do estado nutricional de ratas desnutridas Glutamine supplementation effect in hematological parameters and nutritional status of rats submitted to malnutrition protocol

Directory of Open Access Journals (Sweden)

Natália Cristina Lima Rodrigues

2007-12-01

Full Text Available RACIONAL: A glutamina é o aminoácido mais abundante no sangue, por desempenhar importante papel no sistema imune. É considerado aminoácido condicionalmente essencial em situações como desnutrição protéico-calórica. OBJETIVO: Verificar o efeito da dieta suplementada com glutamina sobre variáveis bioquímicas e hematológicas de ratas submetidas a protocolo de desnutrição, induzido por dieta rica em lactose. MÉTODOS: Ratas Wistar fêmeas (n=20 e com 21 dias de idade, foram submetidas ou não à desnutrição calórico-protéica induzida por diarréia, através da administração de dieta rica em lactose 60% durante 15 dias. Após o período de desnutrição, animais eutróficos ou desnutridos permaneceram durante 30 dias com oferta de diferentes dietas (padrão e experimentais. De acordo com estado e tratamento nutricionais, os animais foram distribuídos aleatoriamente em quatro grupos distintos: 1 GC: animais eutróficos + dieta padrão, 2 GD: animais desnutridos + dieta rica em lactose (60%, 3 GDGLN: animais desnutridos + dieta rica em glutamina (2%; e 4 GDP: animais desnutridos + dieta padrão. Após os 30 dias de tratamento nutricional, amostras de sangue foram obtidas por punção cardíaca para avaliação de variáveis bioquímicas (proteínas totais, albumina, uréia e hematológicas (quantificação da série vermelha e branca. RESULTADOS: Após 15 dias do início do experimento o ganho de peso dos grupos GD (46,4 ± 2,60g, GDGLN (39,2 ± 8,9g e GDP (33,2 ± 11,5g foi menor em relação ao controle (64 ± 4,24g, PBACKGROUND: Glutamine is the most abundant amino acid in blood stream, playing an important role in the immune system. It is conditionally considered an essential amino acid to certain state conditions such as protein-energy malnutrition. AIM: To verify the effect of glutamine diet supplemented on hematological and biochemical variables in rats subjected to protocol of malnutrition, induced by an enriched lactose

LncRNA TUG1 sponges miR-145 to promote cancer progression and regulate glutamine metabolism via Sirt3/GDH axis.

Science.gov (United States)

Zeng, Bing; Ye, Huilin; Chen, Jianming; Cheng, Di; Cai, Canfeng; Chen, Guoxing; Chen, Xiang; Xin, Haiyang; Tang, Chaoming; Zeng, Jun

2017-12-26

Long noncoding RNAs (lncRNAs) are important regulators in cancer progression. Deregulation of the lncRNA taurine upregulated gene 1 (TUG1) predicts poor prognosis and is implicated in the development of several cancers. In this study, we investigated the role of TUG1 in the pathogenesis of intrahepatic cholangiocarcinoma (ICC). We found that TUG1 is upregulated in ICC samples, which correlates with poor prognosis and adverse clinical pathological characteristics. Knockdown of TUG1 inhibited the proliferation, motility, and invasiveness of cultured ICC cells, and decreased tumor burden in a xenograft mouse model. When we explored the mechanisms underlying these effects, we found that TUG1 acts as an endogenous competing RNA (ceRNA) that 'sponges' miR-145, thereby preventing the degradation of Sirt3 mRNA and increasing expression of Sirt3 and GDH proteins. Accordingly, glutamine consumption, α-KG production, and ATP levels were dramatically decreased by TUG1 knockdown in ICC cells, and this effect was reversed by miR-145 inhibition. These findings indicate that the TUG1/miR-145/Sirt3/GDH regulatory network may provide a novel therapeutic strategy for treatment of ICC.

Specific nongluten proteins of wheat are novel target antigens in celiac disease humoral response

Science.gov (United States)

Background: Celiac disease is an immune-mediated enteropathy that is generally understood to be triggered by the ingestion of gluten proteins of wheat and related cereals. The skin manifestation of the condition is known as dermatitis herpetiformis. Antibody response to native and deamidated seque...

Impact of family history of alcoholism on glutamine/glutamate ratio in anterior cingulate cortex in substance-naïve adolescents.

Science.gov (United States)

Cohen-Gilbert, Julia E; Sneider, Jennifer T; Crowley, David J; Rosso, Isabelle M; Jensen, J Eric; Silveri, Marisa M

2015-12-01

Neuroimaging studies of individuals with family histories of alcoholism provide evidence suggesting neurobiological risk factors for alcoholism. Youth family history positive (FH+) for alcoholism exhibit increased impulsivity compared to family history negative (FH-) peers in conjunction with altered functional activation in prefrontal cortex, including anterior cingulate cortex (ACC). This study examined glutamate (Glu) and glutamine (Gln), amino acids vital to protein synthesis, cellular metabolism and neurotransmission, acquired from ACC and parieto-occipital cortex (POC) using magnetic resonance spectroscopy (MRS) at 4T. Participants were 28 adolescents (13 male, 12-14 yrs) and 31 emerging adults (16 male, 18-25 yrs), stratified into FH- and FH+ groups. Significantly higher ACC Gln/Glu was observed in emerging adults versus adolescents in FH- but not FH+ groups. In FH- adolescents, higher impulsivity was significantly associated with higher ACC Gln/Glu. In FH+ emerging adults, higher impulsivity was negatively associated with ACC Gln/Glu. No differences or associations were observed for POC. These findings provide preliminary evidence that family history of alcoholism is associated with a neurochemical profile that may influence normative age differences in glutamatergic metabolites and their association with impulse control, which together could confer greater genetic risk of addiction later in life. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Reduced γ-Aminobutyric Acid and Glutamate+Glutamine Levels in Drug-Naïve Patients with First-Episode Schizophrenia but Not in Those at Ultrahigh Risk

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Junjie Wang

2016-01-01

Full Text Available Altered γ-aminobutyric acid (GABA, glutamate (Glu levels, and an imbalance between GABAergic and glutamatergic neurotransmissions have been involved in the pathophysiology of schizophrenia. However, it remains unclear how these abnormalities impact the onset and course of psychosis. In the present study, 21 drug-naïve subjects at ultrahigh risk for psychosis (UHR, 16 drug-naïve patients with first-episode schizophrenia (FES, and 23 healthy controls (HC were enrolled. In vivo GABA and glutamate+glutamine (Glx levels in the medial prefrontal cortex were measured using proton magnetic resonance spectroscopy. Medial prefrontal GABA and Glx levels in FES patients were significantly lower than those in HC and UHR, respectively. GABA and Glx levels in UHR were comparable with those in HC. In each group, there was a positive correlation between GABA and Glx levels. Reduced medial prefrontal GABA and Glx levels thus may play an important role in the early stages of schizophrenia.

Reduced γ-Aminobutyric Acid and Glutamate+Glutamine Levels in Drug-Naïve Patients with First-Episode Schizophrenia but Not in Those at Ultrahigh Risk.

Science.gov (United States)

Wang, Junjie; Tang, Yingying; Zhang, Tianhong; Cui, Huiru; Xu, Lihua; Zeng, Botao; Li, Yu; Li, Gaiying; Li, Chunbo; Liu, Hui; Lu, Zheng; Zhang, Jianye; Wang, Jijun

2016-01-01

Altered γ -aminobutyric acid (GABA), glutamate (Glu) levels, and an imbalance between GABAergic and glutamatergic neurotransmissions have been involved in the pathophysiology of schizophrenia. However, it remains unclear how these abnormalities impact the onset and course of psychosis. In the present study, 21 drug-naïve subjects at ultrahigh risk for psychosis (UHR), 16 drug-naïve patients with first-episode schizophrenia (FES), and 23 healthy controls (HC) were enrolled. In vivo GABA and glutamate+glutamine (Glx) levels in the medial prefrontal cortex were measured using proton magnetic resonance spectroscopy. Medial prefrontal GABA and Glx levels in FES patients were significantly lower than those in HC and UHR, respectively. GABA and Glx levels in UHR were comparable with those in HC. In each group, there was a positive correlation between GABA and Glx levels. Reduced medial prefrontal GABA and Glx levels thus may play an important role in the early stages of schizophrenia.

Proteins and their modifications in a medieval mummy

Czech Academy of Sciences Publication Activity Database

Mikšík, Ivan; Sedláková, Pavla; Pataridis, Statis; Bortolotti, F.; Gottardo, R.

2016-01-01

Roč. 25, č. 11 (2016), s. 2037-2044 ISSN 0961-8368 R&D Projects: GA ČR(CZ) GA15-01948S Institutional support: RVO:67985823 Keywords : mummy * collagen * protein modification * deamidation * carbamylation * carboxymethylation Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 2.523, year: 2016

Regulation of the subunit composition of plastidic glutamine synthetase of the wild-type and of the phytochrome-deficient aurea mutant of tomato by blue/UV-A- or by UV-B-light

International Nuclear Information System (INIS)

Migge, A.; Carrayol, E.; Hirel, B.; Lohmann, M.; Meya, G.; Becker, T.W.

1998-01-01

The photomorphogenetic aurea mutant of tomato severely deficient in spectrophotometrically active phytochromes was used to study the light-regulation of the single-copy nuclear gene encoding plastidic glutamine synthetase (GS-2; EC 6.1.3.2). The de-etiolation of dark-grown aurea mutant seedling cotyledons showed an obligatory dependency on blue light. A limited red light-responsiveness of etiolated aurea cotyledons is, however, retained as seen by the stimulation of both the GS-2 transcript and protein level in the cotyledons of aurea seedlings during growth in red light. The subunits of the octameric GS-2 enzyme were represented by polypeptides with similar electrophoretic mobilities (polypeptides a) in etiolated wild-type or aurea mutant cotyledons. GS-2 proteins with similar apparent molecular masses were also seen in the cotyledons of red light-grown aurea mutant seedlings. In contrast, GS-2 polypeptides with different apparent molecular masses (polypeptides a and b) were detected in the cotyledons of wild-type seedlings grown in red light. This difference indicates that the (post-translational) modification of tomato GS-2 subunit composition is mediated by the photoreceptor phytochrome. The illumination of etiolated wild-type or aurea cotyledons with UV-A- or UV-B-light light resulted in an increase in both the GS-2 transcript and protein level. Following illumination of etiolated wild-type seedlings with UV-A-light, the relative proportion of the GS-2 polypeptides a and b was similar than upon irradiation with blue light but different than after exposure to UV-B- or red light. This result suggests the involvement of a blue/ UV-A-light-specific photoreceptor in the regulation of tomato GS-2 subunit composition. (author)

A conserved glutamine plays a central role in LOV domain signal transmission and duration

Science.gov (United States)

Nash, Abigail I.; Ko, Wen-Huang; Harper, Shannon M.; Gardner, Kevin H.

2009-01-01

Light is a key stimulus for plant biological functions, several of which are controlled by light-activated kinases known as phototropins, a group of kinases that contain two light-sensing domains (LOV, Light-Oxygen-Voltage domains) and a C-terminal serine/threonine kinase domain. The second sensory domain, LOV2, plays a key role in regulating kinase enzymatic activity via the photochemical formation of a covalent adduct between a LOV2 cysteine residue and an internally-bound flavin mononucleotide (FMN) chromophore. Subsequent conformational changes in LOV2 lead to the unfolding of a peripheral Jα helix, and ultimately, phototropin kinase activation. To date, the mechanism coupling bond formation and helix dissociation has remained unclear. Previous studies found that a conserved glutamine residue (Q513 in the Avena sativa phototropin 1 LOV2 (AsLOV2) domain) switches its hydrogen-bonding pattern with FMN upon light stimulation. Located in the immediate vicinity of the FMN binding site, this Gln residue is provided by the Iβ strand that interacts with the Jα helix, suggesting a route for signal propagation from the core of the LOV domain to its peripheral Jα helix. To test whether Q513 plays a key role in tuning the photochemical and transduction properties of AsLOV2, we designed two point mutations, Q513L and Q513N, and monitored the effects on the chromophore and protein using a combination of UV-visible absorbance and circular dichroism spectroscopy, limited proteolysis, and solution NMR. The results show that these mutations significantly dampen the changes between the dark and lit state AsLOV2 structures, leaving the protein in a pseudo-dark state (Q513L) or a pseudo-lit state (Q513N) conformation. Further, both mutations changed the photochemical properties of this receptor, particularly the lifetime of the photoexcited signaling states. Together, these data establish that this residue plays a central role in both spectral tuning and signal propagation from

Optimization of cell line development in the GS-CHO expression system using a high-throughput, single cell-based clone selection system.

Science.gov (United States)

Nakamura, Tsuyoshi; Omasa, Takeshi

2015-09-01

Therapeutic antibodies are commonly produced by high-expressing, clonal and recombinant Chinese hamster ovary (CHO) cell lines. Currently, CHO cells dominate as a commercial production host because of their ease of use, established regulatory track record, and safety profile. CHO-K1SV is a suspension, protein-free-adapted CHO-K1-derived cell line employing the glutamine synthetase (GS) gene expression system (GS-CHO expression system). The selection of high-producing mammalian cell lines is a crucial step in process development for the production of therapeutic antibodies. In general, cloning by the limiting dilution method is used to isolate high-producing monoclonal CHO cells. However, the limiting dilution method is time consuming and has a low probability of monoclonality. To minimize the duration and increase the probability of obtaining high-producing clones with high monoclonality, an automated single cell-based clone selector, the ClonePix FL system, is available. In this study, we applied the high-throughput ClonePix FL system for cell line development using CHO-K1SV cells and investigated efficient conditions for single cell-based clone selection. CHO-K1SV cell growth at the pre-picking stage was improved by optimizing the formulation of semi-solid medium. The efficiency of picking and cell growth at the post-picking stage was improved by optimization of the plating time without decreasing the diversity of clones. The conditions for selection, including the medium formulation, were the most important factors for the single cell-based clone selection system to construct a high-producing CHO cell line. Copyright © 2015 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Activation of MAPK/ERK signaling by Burkholderia pseudomallei cycle inhibiting factor (Cif.

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Mei Ying Ng

Full Text Available Cycle inhibiting factors (Cifs are virulence proteins secreted by the type III secretion system of some Gram-negative pathogenic bacteria including Burkholderia pseudomallei. Cif is known to function to deamidate Nedd8, leading to inhibition of Cullin E3 ubiquitin ligases (CRL and consequently induction of cell cycle arrest. Here we show that Cif can function as a potent activator of MAPK/ERK signaling without significant activation of other signaling pathways downstream of receptor tyrosine kinases. Importantly, we found that the ability of Cif to activate ERK is dependent on its deamidase activity, but independent of Cullin E3 ligase inhibition. This suggests that apart from Nedd8, other cellular targets of Cif-dependent deamidation exist. We provide evidence that the mechanism involved in Cif-mediated ERK activation is dependent on recruitment of the Grb2-SOS1 complex to the plasma membrane. Further investigation revealed that Cif appears to modify the phosphorylation status of SOS1 in a region containing the CDC25-H and proline-rich domains. It is known that prolonged Cullin E3 ligase inhibition leads to cellular apoptosis. Therefore, we hypothesize that ERK activation is an important mechanism to counter the pro-apoptotic effects of Cif. Indeed, we show that Cif dependent ERK activation promotes phosphorylation of the proapoptotic protein Bim, thereby potentially conferring a pro-survival signal. In summary, we identified a novel deamidation-dependent mechanism of action of the B. pseudomallei virulence factor Cif/CHBP to activate MAPK/ERK signaling. Our study demonstrates that bacterial proteins such as Cif can serve as useful molecular tools to uncover novel aspects of mammalian signaling pathways.

In vivo dynamic turnover of cerebral 13C isotopomers from [U- 13C]glucose

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Xu, Su; Shen, Jun

2006-10-01

An INEPT-based 13C MRS method and a cost-effective and widely available 11.7 Tesla 89-mm bore vertical magnet were used to detect dynamic 13C isotopomer turnover from intravenously infused [U- 13C]glucose in a 211 μL voxel located in the adult rat brain. The INEPT-based 1H → 13C polarization transfer method is mostly adiabatic and therefore minimizes signal loss due to B 1 inhomogeneity of the surface coils used. High quality and reproducible data were acquired as a result of combined use of outer volume suppression, ISIS, and the single-shot three-dimensional localization scheme built in the INEPT pulse sequence. Isotopomer patterns of both glutamate C4 at 34.00 ppm and glutamine C4 at 31.38 ppm are dominated first by a doublet originated from labeling at C4 and C5 but not at C3 (with 1JC4C5 = 51 Hz) and then by a quartet originated from labeling at C3, C4, and C5 (with 1JC3C4 = 35 Hz). A lag in the transition of glutamine C4 pattern from doublet-dominance to quartet dominance as compared to glutamate C4 was observed, which provides an independent verification of the precursor-product relationship between neuronal glutamate and glial glutamine and a significant intercompartmental cerebral glutamate-glutamine cycle between neurons and glial cells.

Effect of nerve growth factor on the synthesis of amino acids in PC12 cells

International Nuclear Information System (INIS)

Zielke, H.R.; Tildon, J.T.; Kauffman, F.C.; Baab, P.J.

1989-01-01

Radioactive short-chain fatty acids preferentially label glutamine relative to glutamate in brain due to compartmentation of glutamine and glutamate. To determine whether this phenomenon occurs in a single cell culture model, we examined the effect of fatty acid chain length on the synthesis as well as pool size of selected amino acids in rat pheochromocytoma PC12 cells, a cell culture model of the large glutamate compartment in neurons. Intracellular 14C-amino acids were quantitated by HPLC, and the incorporation of [U-14C]-glucose, [1-14C]-butyrate, [1-14C]-octanoate, and [1-14C]-palmitate into five amino acids was measured in native and NGF-treated PC12 cells. NGF pretreatment decreased the intracellular concentration of amino acids as did addition of fatty acids but these effects were not additive. Specific activities of amino acids in native cells labelled by 14C-octanoate were 1,300 DPM/nmol, 490 DPM/nmol, 200 DPM/nmol, and 110 DPM/nmol for glutamate, aspartate, glutamine, and serine, respectively. No radioactivity was detected in alanine. Similar specific activities were noted when 14C-butyrate was the precursor; however, there was at least 5-fold less if 14C-palmitate was the precursor. Pretreatment of cells with NGF decreased the specific activity of amino acids by 25-65%. Specific activities of amino acids synthesized from 14C-glucose decreased in the following order: glutamate, 1,640 DPM/nmol; aspartate, 1,210 DPM/nmol; alanine, 580 DPM/nmol; glutamine, 275 DPM/nmol; and serine, 80 DPM/nmol for native cells. NGF pretreatment decreased the specific activities of glutamate and glutamine, but not of the other 3 amino acids. The preferred precursor for glutamate synthesis in native PC12 cells was glucose followed by octanoate, butyrate and palmitate (16:6:3:1)

Transfected Cell Microarrays for the Expression of Membrane-Displayed Single-Chain Antibodies

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2011-01-01

QuickChange R© Site-Directed Mutagenesis Kit, were stored in 50 μl aliquots at –80◦C for up to 6 months (see Note 3). 4. NZY broth: 0.01% (w/v) NZ amine ( casein ...glutamine, 17 mM sodium bicarbonate, 1 mM sodium pyruvate, 1% antibiotic/antimycotic (v/v), 10% fetal bovine serum. The media can be stored at 4◦C for...FluoReporter FITC protein labeling kit (Molecular Probes) was stored at 4◦C shielded from light for up to 6 months. 2. 1 M sodium bicarbonate buffer pH9

In vivo production of non-glycosylated recombinant proteins in Nicotiana benthamiana plants by co-expression with Endo-β-N-acetylglucosaminidase H (Endo H) of Streptomyces plicatus

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Cicek, Kader; Gulec, Burcu; Ungor, Rifat; Hasanova, Gulnara

2017-01-01

A plant transient expression system, with eukaryotic post-translational modification machinery, offers superior efficiency, scalability, safety, and lower cost over other expression systems. However, due to aberrant N-glycosylation, this expression system may not be a suitable expression platform for proteins not carrying N-linked glycans in the native hosts. Therefore, it is crucial to develop a strategy to produce target proteins in a non-glycosylated form while preserving their native sequence, conformation and biological activity. Previously, we developed a strategy for enzymatic deglycosylation of proteins in planta by co-expressing bacterial peptide-N-glycosidase F (PNGase F). Though PNGase F removes oligosaccharides from glycosylated proteins, in so doing it causes an amino acid change due to the deamidation of asparagine to aspartate in the N-X-S/T site. Endo-β-N-acetylglucosaminidase (EC3.2.1.96, Endo H), another deglycosylating enzyme, catalyzes cleavage between two N-Acetyl-D-glucosamine residues of the chitobiose core of N-linked glycans, leaving a single N-Acetyl-D-glucosamine residue without the concomitant deamidation of asparagine. In this study, a method for in vivo deglycosylation of recombinant proteins in plants by transient co-expression with bacterial Endo H is described for the first time. Endo H was fully active in vivo. and successfully cleaved N-linked glycans from glycoproteins were tested. In addition, unlike the glycosylated form, in vivo Endo H deglycosylated Pfs48/45 was recognized by conformational specific Pfs48/45 monoclonal antibody, in a manner similar to its PNGase F deglycosylated counterpart. Furthermore, the deglycosylated PA83 molecule produced by Endo H showed better stability than a PNGase F deglycosylated counterpart. Thus, an Endo H in vivo deglycosylation approach provides another opportunity to develop vaccine antigens, therapeutic proteins, antibodies, and industrial enzymes. PMID:28827815

Glutamine Supplementation Attenuates Expressions of Adhesion Molecules and Chemokine Receptors on T Cells in a Murine Model of Acute Colitis

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Yu-Chen Hou

2014-01-01

Full Text Available Background. Migration of T cells into the colon plays a major role in the pathogenesis in inflammatory bowel disease. This study investigated the effects of glutamine (Gln supplementation on chemokine receptors and adhesion molecules expressed by T cells in mice with dextran sulfate sodium- (DSS- induced colitis. Methods. C57BL/6 mice were fed either a standard diet or a Gln diet replacing 25% of the total nitrogen. After being fed the diets for 5 days, half of the mice from both groups were given 1.5% DSS in drinking water to induce colitis. Mice were killed after 5 days of DSS exposure. Results. DSS colitis resulted in higher expression levels of P-selectin glycoprotein ligand- (PSGL- 1, leukocyte function-associated antigen- (LFA- 1, and C-C chemokine receptor type 9 (CCR9 by T helper (Th and cytotoxic T (Tc cells, and mRNA levels of endothelial adhesion molecules in colons were upregulated. Gln supplementation decreased expressions of PSGL-1, LFA-1, and CCR9 by Th cells. Colonic gene expressions of endothelial adhesion molecules were also lower in Gln-colitis mice. Histological finding showed that colon infiltrating Th cells were less in the DSS group with Gln administration. Conclusions. Gln supplementation may ameliorate the inflammation of colitis possibly via suppression of T cell migration.

Effects of short-term dietary restriction and glutamine supplementation in vitro on the modulation of inflammatory properties.

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C de Oliveira, Dalila; Santos, Ed Wilson; Nogueira-Pedro, Amanda; Xavier, José Guilherme; Borelli, Primavera; Fock, Ricardo Ambrósio

2018-04-01

Dietary restriction (DR) is a nutritional intervention that exerts profound effects on biochemical and immunologic parameters, modulating some inflammatory properties. Glutamine (GLN) is a conditionally essential amino acid that can modulate inflammatory properties. However, there is a lack of data evaluating the effects of DR and GLN supplementation, especially in relation to inflammatory cytokine production and the expression of transcription factors such as nuclear factor (NF)-κB. We subjected 3-mo-old male Balb/c mice to DR by reducing their food intake by 30%. DR animals lost weight and showed reduced levels of serum triacylglycerols, glucose, cholesterol, and calcium as well as a reduction in bone density. Additionally, blood, peritoneal, and spleen cellularity were reduced, lowering the number of peritoneal F4/80- and CD86-positive cells and the total number of splenic CD4- and CD8-positive cells. The production of interleukin (IL)-10 and the expression of NF-κB in splenic cells were not affected by DR or by GLN supplementation. However, peritoneal macrophages from DR animals showed reduced IL-12 and tumor necrosis factor-α production and increased IL-10 production with reduced phosphorylation of NF-κB expression. Additionally, GLN was able to modulate cytokine production by peritoneal cells from the control group, although no effects were observed in cells from the DR group. DR induces biochemical and immunologic changes, in particular by reducing IL-12 and tumor necrosis factor-α production by macrophages and clearly upregulating IL-10 production, whereas GLN supplementation did not modify these parameters in cells from DR animals. Copyright © 2017 Elsevier Inc. All rights reserved.

Development of an Improved Mammalian Overexpression Method for Human CD62L

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Brown, Haley A.; Roth, Gwynne; Holzapfel, Genevieve; Shen, Sarek; Rahbari, Kate; Ireland, Joanna; Zou, Zhongcheng; Sun, Peter D.

2014-01-01

We have previously developed a glutamine synthetase (GS)-based mammalian recombinant protein expression system that is capable of producing 5 to 30 mg/L recombinant proteins. The over expression is based on multiple rounds of target gene amplification driven by methionine sulfoximine (MSX), an inhibitor of glutamine synthetase. However, like other stable mammalian over expression systems, a major shortcoming of the GS-based expression system is its lengthy turn-around time, typically taking 4–6 months to produce. To shorten the construction time, we replaced the muti-round target gene amplifications with single-round in situ amplifications, thereby shortening the cell line construction to 2 months. The single-round in situ amplification method resulted in highest recombinant CD62L expressing CHO cell lines producing ~5mg/L soluble CD62L, similar to those derived from the multi-round amplification and selection method. In addition, we developed a MSX resistance assay as an alternative to utilizing ELISA for evaluating the expression level of stable recombinant CHO cell lines. PMID:25286402

Stable isotope dilution HILIC-MS/MS method for accurate quantification of glutamic acid, glutamine, pyroglutamic acid, GABA and theanine in mouse brain tissues.

Science.gov (United States)

Inoue, Koichi; Miyazaki, Yasuto; Unno, Keiko; Min, Jun Zhe; Todoroki, Kenichiro; Toyo'oka, Toshimasa

2016-01-01

In this study, we developed the stable isotope dilution hydrophilic interaction liquid chromatography with tandem mass spectrometry (HILIC-MS/MS) technique for the accurate, reasonable and simultaneous quantification of glutamic acid (Glu), glutamine (Gln), pyroglutamic acid (pGlu), γ-aminobutyric acid (GABA) and theanine in mouse brain tissues. The quantification of these analytes was accomplished using stable isotope internal standards and the HILIC separating mode to fully correct the intramolecular cyclization during the electrospray ionization. It was shown that linear calibrations were available with high coefficients of correlation (r(2)  > 0.999, range from 10 pmol/mL to 50 mol/mL). For application of the theanine intake, the determination of Glu, Gln, pGlu, GABA and theanine in the hippocampus and central cortex tissues was performed based on our developed method. In the region of the hippocampus, the concentration levels of Glu and pGlu were significantly reduced during reality-based theanine intake. Conversely, the concentration level of GABA increased. This result showed that transited theanine has an effect on the metabolic balance of Glu analogs in the hippocampus. Copyright © 2015 John Wiley & Sons, Ltd.

Blocking anaplerotic entry of glutamine into the TCA cycle sensitizes K-Ras mutant cancer cells to cytotoxic drugs.

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Saqcena, M; Mukhopadhyay, S; Hosny, C; Alhamed, A; Chatterjee, A; Foster, D A

2015-05-14

Cancer cells undergo a metabolic transformation that allows for increased anabolic demands, wherein glycolytic and tricarboxylic acid (TCA) cycle intermediates are shunted away for the synthesis of biological molecules required for cell growth and division. One of the key shunts is the exit of citrate from the mitochondria and the TCA cycle for the generation of cytosolic acetyl-coenzyme A that can be used for fatty acid and cholesterol biosynthesis. With the loss of mitochondrial citrate, cancer cells rely on the 'conditionally essential' amino acid glutamine (Q) as an anaplerotic carbon source for TCA cycle intermediates. Although Q deprivation causes G1 cell cycle arrest in non-transformed cells, its impact on the cancer cell cycle is not well characterized. We report here a correlation between bypass of the Q-dependent G1 checkpoint and cancer cells harboring K-Ras mutations. Instead of arresting in G1 in response to Q-deprivation, K-Ras-driven cancer cells arrest in either S- or G2/M-phase. Inhibition of K-Ras effector pathways was able to revert cells to G1 arrest upon Q deprivation. Blocking anaplerotic utilization of Q mimicked Q deprivation--causing S- and G2/M-phase arrest in K-Ras mutant cancer cells. Significantly, Q deprivation or suppression of anaplerotic Q utilization created synthetic lethality to the cell cycle phase-specific cytotoxic drugs, capecitabine and paclitaxel. These data suggest that disabling of the G1 Q checkpoint could represent a novel vulnerability of cancer cells harboring K-Ras and possibly other mutations that disable the Q-dependent checkpoint.

N-(Pivaloyloxy)alkoxy-carbonyl Prodrugs of the Glutamine Antagonist 6-Diazo-5-oxo-l-norleucine (DON) as a Potential Treatment for HIV Associated Neurocognitive Disorders.

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Nedelcovych, Michael T; Tenora, Lukáš; Kim, Boe-Hyun; Kelschenbach, Jennifer; Chao, Wei; Hadas, Eran; Jančařík, Andrej; Prchalová, Eva; Zimmermann, Sarah C; Dash, Ranjeet P; Gadiano, Alexandra J; Garrett, Caroline; Furtmüller, Georg; Oh, Byoungchol; Brandacher, Gerald; Alt, Jesse; Majer, Pavel; Volsky, David J; Rais, Rana; Slusher, Barbara S

2017-08-24

Aberrant excitatory neurotransmission associated with overproduction of glutamate has been implicated in the development of HIV-associated neurocognitive disorders (HAND). The glutamine antagonist 6-diazo-5-oxo-l-norleucine (DON, 14) attenuates glutamate synthesis in HIV-infected microglia/macrophages, offering therapeutic potential for HAND. We show that 14 prevents manifestation of spatial memory deficits in chimeric EcoHIV-infected mice, a model of HAND. 14 is not clinically available, however, because its development was hampered by peripheral toxicities. We describe the synthesis of several substituted N-(pivaloyloxy)alkoxy-carbonyl prodrugs of 14 designed to circulate inert in plasma and be taken up and biotransformed to 14 in the brain. The lead prodrug, isopropyl 6-diazo-5-oxo-2-(((phenyl(pivaloyloxy)methoxy)carbonyl)amino)hexanoate (13d), was stable in swine and human plasma but liberated 14 in swine brain homogenate. When dosed systemically in swine, 13d provided a 15-fold enhanced CSF-to-plasma ratio and a 9-fold enhanced brain-to-plasma ratio relative to 14, opening a possible clinical path for the treatment of HAND.

Glutaminolysis: A Hallmark of Cancer Metabolism.

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Yang, Lifeng; Venneti, Sriram; Nagrath, Deepak

2017-06-21

Glutamine is the most abundant circulating amino acid in blood and muscle and is critical for many fundamental cell functions in cancer cells, including synthesis of metabolites that maintain mitochondrial metabolism; generation of antioxidants to remove reactive oxygen species; synthesis of nonessential amino acids (NEAAs), purines, pyrimidines, and fatty acids for cellular replication; and activation of cell signaling. In light of the pleiotropic role of glutamine in cancer cells, a comprehensive understanding of glutamine metabolism is essential for the development of metabolic therapeutic strategies for targeting cancer cells. In this article, we review oncogene-, tumor suppressor-, and tumor microenvironment-mediated regulation of glutamine metabolism in cancer cells. We describe the mechanism of glutamine's regulation of tumor proliferation, metastasis, and global methylation. Furthermore, we highlight the therapeutic potential of glutamine metabolism and emphasize that clinical application of in vivo assessment of glutamine metabolism is critical for identifying new ways to treat patients through glutamine-based metabolic therapy.

Parallel Changes in Intracellular Water Volume and pH Induced by NH3/NH4+ Exposure in Single Neuroblastoma Cells

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Víctor M. Blanco

2013-12-01

not sufficient to trigger these responses. Inhibition of glutamine synthetase partially blocked the NH4Cl-induced swelling. Conclusions: A quantitative description of the osmotic changes produced by exposure to NH3/NH4+ in single neurons and glial cells shows that ∼35 to 45% of the initial cell swelling can be explained by intracellular accumulation of NH4+ due to rapid permeation and protonation of NH3. Another∼23% of the swelling can be accounted for by rapid glutamine accumulation. The results are discussed in terms of basic cell physiology and their potential relevance to the pathophysiology of hyperammonemic cellular brain edema.

Development of SI-traceable C-peptide certified reference material NMIJ CRM 6901-a using isotope-dilution mass spectrometry-based amino acid analyses.

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Kinumi, Tomoya; Goto, Mari; Eyama, Sakae; Kato, Megumi; Kasama, Takeshi; Takatsu, Akiko

2012-07-01

A certified reference material (CRM) is a higher-order calibration material used to enable a traceable analysis. This paper describes the development of a C-peptide CRM (NMIJ CRM 6901-a) by the National Metrology Institute of Japan using two independent methods for amino acid analysis based on isotope-dilution mass spectrometry. C-peptide is a 31-mer peptide that is utilized for the evaluation of β-cell function in the pancreas in clinical testing. This CRM is a lyophilized synthetic peptide having the human C-peptide sequence, and contains deamidated and pyroglutamylated forms of C-peptide. By adding water (1.00 ± 0.01) g into the vial containing the CRM, the C-peptide solution in 10 mM phosphate buffer saline (pH 6.6) is reconstituted. We assigned two certified values that represent the concentrations of total C-peptide (mixture of C-peptide, deamidated C-peptide, and pyroglutamylated C-peptide) and C-peptide. The certified concentration of total C-peptide was determined by two amino acid analyses using pre-column derivatization liquid chromatography-mass spectrometry and hydrophilic chromatography-mass spectrometry following acid hydrolysis. The certified concentration of C-peptide was determined by multiplying the concentration of total C-peptide by the ratio of the relative area of C-peptide to that of the total C-peptide measured by liquid chromatography. The certified value of C-peptide (80.7 ± 5.0) mg/L represents the concentration of the specific entity of C-peptide; on the other hand, the certified value of total C-peptide, (81.7 ± 5.1) mg/L can be used for analyses that does not differentiate deamidated and pyroglutamylated C-peptide from C-peptide itself, such as amino acid analyses and immunochemical assays.

Prince Cangrande’s Collagen: Study of Protein Modification on the Mummy of the Lord of Verona, Italy (1291–1329 AD)

Czech Academy of Sciences Publication Activity Database

Mikšík, Ivan; Sedláková, Pavla; Pataridis, Statis; Bortolotti, F.; Gottardo, R.; Tagliaro, F.

2014-01-01

Roč. 77, 21-22 (2014), s. 1503-1510 ISSN 0009-5893 R&D Projects: GA ČR(CZ) GAP206/12/0453; GA ČR(CZ) GA13-17224S Institutional support: RVO:67985823 Keywords : HPLC/MS * collagen * deamidation * mummy * protein modification Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 1.411, year: 2014

Limitations to the development of recombinant human embryonic kidney 293E cells using glutamine synthetase-mediated gene amplification: Methionine sulfoximine resistance.

Science.gov (United States)

Yu, Da Young; Noh, Soo Min; Lee, Gyun Min

2016-08-10

To investigate the feasibility of glutamine synthetase (GS)-mediated gene amplification in HEK293 cells for the high-level stable production of therapeutic proteins, HEK293E cells were transfected by the GS expression vector containing antibody genes and were selected at various methionine sulfoximine (MSX) concentrations in 96-well plates. For a comparison, CHOK1 cells were transfected by the same GS expression vector and selected at various MSX concentrations. Unlike CHOK1 cells, HEK293E cells producing high levels of antibodies were not selected at all. For HEK293E cells, the number of wells with the cell pool did not decrease with an increase in the concentration of MSX up to 500μM MSX. A q-RT-PCR analysis confirmed that the antibody genes in the HEK293E cells, unlike the CHOK1 cells, were not amplified after increasing the MSX concentration. It was found that the GS activity in HEK293E cells was much higher than that in CHOK1 cells (PMSX and therefore hampers GS-mediated gene amplification by MSX. Thus, in order to apply the GS-mediated gene amplification system to HEK293 cells, the endogenous GS expression level in HEK293 cells needs to be minimized by knock-out or down-regulation methods. Copyright © 2016 Elsevier B.V. All rights reserved.

Effect of 8-bromo-cAMP and dexamethasone on glutamate metabolism in rat astrocytes

International Nuclear Information System (INIS)

Zielke, H.R.; Tildon, J.T.; Landry, M.E.; Max, S.R.

1990-01-01

Glutamine synthetase (GS) activity in cultured rat astrocytes was measured in extracts and compared to the intracellular rate of glutamine synthesis by intact control astrocytes or astrocytes exposed to 1 mM 8-bromo-cAMP (8Br-cAMP) + 1 microM dexamethasone (DEX) for 4 days. GS activity in extracts of astrocytes treated with 8Br-cAMP + DEX was 7.5 times greater than the activity in extracts of control astrocytes. In contrast, the intracellular rate of glutamine synthesis by intact cells increased only 2-fold, suggesting that additional intracellular effectors regulate the expression of GS activity inside the intact cell. The rate of glutamine synthesis by astrocytes was 4.3 times greater in MEM than in HEPES buffered Hank's salts. Synthesis of glutamine by intact astrocytes cultured in MEM was independent of the external glutamine or ammonia concentrations but was increased by higher extracellular glutamate concentrations. In studies with intact astrocytes 80% of the original [U- 14 C]glutamate was recovered in the medium as radioactive glutamine, 2-3% as aspartate, and 7% as glutamate after 2 hours for both control and treated astrocytes. The results suggest: (1) astrocytes are highly efficient in the conversion of glutamate to glutamine; (2) induction of GS activity increases the rate of glutamate conversion to glutamine by astrocytes and the rate of glutamine release into the medium; (3) endogenous intracellular regulators of GS activity control the flux of glutamate through this enzymatic reaction; and (4) the composition of the medium alters the rate of glutamine synthesis from external glutamate

Effect of gamma irradiation on the microbiological quality and on the functional properties of proteins in dry red kidney beans (Phaseolus vulgaris)

International Nuclear Information System (INIS)

Dogbevi, M.K.; Vachon, C.; Lacroix, M.

2000-01-01

Gamma-irradiation was found to affect the physicochemical properties of dry red kidney beans. The highest dose used (8 kGy) significantly (P≤0.05) modified the extent of deamidation, the number of sulfhydryl groups, as well as the solubility and the hydrophobicity of the protein. Deamidation, protein solubility and hydrophobicity all increased with the irradiation dose while the number of sulfhydryl groups was reduced by the treatment. Furthermore, irradiation also affected the outgrowth of natural filamentous fungi contaminants present on the dry beans. A dose of 1.5 kGy reduced the number of filamentous fungi by 2 log cycles immediately after treatment. However, the highest dose used (3 kGy) did not eliminate the filamentous fungi completely. Moreover, the filamentous fungi population was a lot less diversified on the irradiated samples. Species of Aspergillus sp. and Penicillium sp. were more abundant on the unirradiated beans while the beans irradiated at 3 kGy contained were predominantly infected by species of Rhizopus sp. , Cladosporium sp. and Alternaria sp. (author)

Effect of gamma irradiation on the microbiological quality and on the functional properties of proteins in dry red kidney beans ( Phaseolus vulgaris)

Science.gov (United States)

Dogbevi, M. K.; Vachon, C.; Lacroix, M.

2000-03-01

Gamma-irradiation was found to affect the physicochemical properties of dry red kidney beans. The highest dose used (8 kGy) significantly ( P⩽0.05) modified the extent of deamidation, the number of sulfhydryl groups, as well as the solubility and the hydrophobicity of the protein. Deamidation, protein solubility and hydrophobicity all increased with the irradiation dose while the number of sulfhydryl groups was reduced by the treatment. Furthermore, irradiation also affected the outgrowth of natural filamentous fungi contaminants present on the dry beans. A dose of 1.5 kGy reduced the number of filamentous fungi by 2 log cycles immediately after treatment. However, the highest dose used (3 kGy) did not eliminate the filamentous fungi completely. Moreover, the filamentous fungi population was a lot less diversified on the irradiated samples. Species of Aspergillus sp. and Penicillium sp. were more abundant on the unirradiated beans while the beans irradiated at 3 kGy contained were predominantly infected by species of Rhizopus sp. , Cladosporium sp. and Alternaria sp.

Effect of gamma irradiation on the microbiological quality and on the functional properties of proteins in dry red kidney beans (Phaseolus vulgaris)

Energy Technology Data Exchange (ETDEWEB)

Dogbevi, M.K.; Vachon, C.; Lacroix, M. E-mail: Monique_Lacroix@iaf.uquebec.ca

2000-03-01

Gamma-irradiation was found to affect the physicochemical properties of dry red kidney beans. The highest dose used (8 kGy) significantly (P{<=}0.05) modified the extent of deamidation, the number of sulfhydryl groups, as well as the solubility and the hydrophobicity of the protein. Deamidation, protein solubility and hydrophobicity all increased with the irradiation dose while the number of sulfhydryl groups was reduced by the treatment. Furthermore, irradiation also affected the outgrowth of natural filamentous fungi contaminants present on the dry beans. A dose of 1.5 kGy reduced the number of filamentous fungi by 2 log cycles immediately after treatment. However, the highest dose used (3 kGy) did not eliminate the filamentous fungi completely. Moreover, the filamentous fungi population was a lot less diversified on the irradiated samples. Species of Aspergillus sp. and Penicillium sp. were more abundant on the unirradiated beans while the beans irradiated at 3 kGy contained were predominantly infected by species of Rhizopus sp. , Cladosporium sp. and Alternaria sp. (author)

Chronic exposure to glufosinate-ammonium induces spatial memory impairments, hippocampal MRI modifications and glutamine synthetase activation in mice.

Science.gov (United States)

Calas, André-Guilhem; Richard, Olivier; Même, Sandra; Beloeil, Jean-Claude; Doan, Bich-Thuy; Gefflaut, Thierry; Même, William; Crusio, Wim E; Pichon, Jacques; Montécot, Céline

2008-07-01

Glufosinate-ammonium (GLA), the active compound of a worldwide-used herbicide, acts by inhibiting the plant glutamine synthetase (GS) leading to a lethal accumulation of ammonia. GS plays a pivotal role in the mammalian brain where it allows neurotransmitter glutamate recycling within astroglia. Clinical studies report that an acute GLA ingestion induces convulsions and memory impairment in humans. Toxicological studies performed at doses used for herbicidal activity showed that GLA is probably harmless at short or medium range periods. However, effects of low doses of GLA on chronically exposed subjects are not known. In our study, C57BL/6J mice were treated during 10 weeks three times a week with 2.5, 5 and 10mg/kg of GLA. Effects of this chronic treatment were assessed at behavioral, structural and metabolic levels by using tests of spatial memory, locomotor activity and anxiety, hippocampal magnetic resonance imaging (MRI) texture analysis, and hippocampal GS activity assay, respectively. Chronic GLA treatments have effects neither on anxiety nor on locomotor activity of mice but at 5 and 10mg/kg induce (1) mild memory impairments, (2) a modification of hippocampal texture and (3) a significant increase in hippocampal GS activity. It is suggested that these modifications may be causally linked one to another. Since glutamate is the main neurotransmitter in hippocampus where it plays a crucial role in spatial memory, hippocampal MRI texture and spatial memory alterations might be the consequences of hippocampal glutamate homeostasis modification revealed by increased GS activity in hippocampus. The present study provides the first data that show cerebral alterations after chronic exposure to GLA.

Denys-Drash syndrome associated WT1 glutamine 369 mutants have altered sequence-preferences and altered responses to epigenetic modifications

Energy Technology Data Exchange (ETDEWEB)

Hashimoto, Hideharu; Zhang, Xing; Zheng, Yu; Wilson, Geoffrey G.; Cheng, Xiaodong

2016-09-04

Mutations in human zinc-finger transcription factor WT1 result in abnormal development of the kidneys and genitalia and an array of pediatric problems including nephropathy, blastoma, gonadal dysgenesis and genital discordance. Several overlapping phenotypes are associated with WT1 mutations, including Wilms tumors, Denys-Drash syndrome (DDS), Frasier syndrome (FS) and WAGR syndrome (Wilms tumor, aniridia, genitourinary malformations, and mental retardation). These conditions vary in severity from individual to individual; they can be fatal in early childhood, or relatively benign into adulthood. DDS mutations cluster predominantly in zinc fingers (ZF) 2 and 3 at the C-terminus of WT1, which together with ZF4 determine the sequence-specificity of DNA binding. We examined three DDS associated mutations in ZF2 of human WT1 where the normal glutamine at position 369 is replaced by arginine (Q369R), lysine (Q369K) or histidine (Q369H). These mutations alter the sequence-specificity of ZF2, we find, changing its affinity for certain bases and certain epigenetic forms of cytosine. X-ray crystallography of the DNA binding domains of normal WT1, Q369R and Q369H in complex with preferred sequences revealed the molecular interactions responsible for these affinity changes. DDS is inherited in an autosomal dominant fashion, implying a gain of function by mutant WT1 proteins. This gain, we speculate, might derive from the ability of the mutant proteins to sequester WT1 into unproductive oligomers, or to erroneously bind to variant target sequences.

Inhibition of nitrogen-fixing activity of the cyanobiont affects the localization of glutamine synthetase in hair cells of Azolla.

Science.gov (United States)

Uheda, Eiji; Maejima, Kazuhiro

2009-10-15

In the Azolla-Anabaena association, the host plant Azolla efficiently incorporates and assimilates ammonium ions that are released from the nitrogen-fixing cyanobiont, probably via glutamine synthetase (GS; EC 6.3.1.2) in hair cells, which are specialized cells protruding into the leaf cavity. In order to clarify the regulatory mechanism underlying ammonium assimilation in the Azolla-Anabaena association, Azolla plants were grown under an argon environment (Ar), in which the nitrogen-fixing activity of the cyanobiont was inhibited specifically and completely. The localization of GS in hair cells was determined by immunoelectron microscopy and quantitative analysis of immunogold labeling. Azolla plants grew healthily under Ar when nitrogen sources, such as NO(3)(-) and NH(4)(+), were provided in the growth medium. Both the number of cyanobacterial cells per leaf and the heterocyst frequency of the plants under Ar were similar to those of plants in a nitrogen environment (N(2)). In hair cells of plants grown under Ar, regardless of the type of nitrogen source provided, only weak labeling of GS was observed in the cytoplasm and in chloroplasts. In contrast, in hair cells of plants grown under N(2), abundant labeling of GS was observed in both sites. These findings indicate that specific inhibition of the nitrogen-fixing activity of the cyanobiont affects the localization of GS isoenzymes. Ammonium fixed and released by the cyanobiont could stimulate GS synthesis in hair cells. Simultaneously, the abundant GS, probably GS1, in these cells, could assimilate ammonium rapidly.

Glutamine reduces myocardial cell apoptosis in a rat model of sepsis by promoting expression of heat shock protein 90.

Science.gov (United States)

Li, Wanxia; Tao, Shaoyu; Wu, Qinghua; Wu, Tao; Tao, Ran; Fan, Jun

2017-12-01

Myocardial cell injury and cardiac myocyte apoptosis are associated with sepsis. Glutamine (Gln) has been reported to repair myocardial cell injury. The aim of this study was to explore the role of Gln on cardiac myocytes in a cecal ligation and puncture (CLP) model of sepsis in Wistar rats. Following induction of sepsis in a CLP rat model, viral encoding heat shock protein 90 (Hsp90) gene and Hsp90dsDNA were designed to express and knockdown Hsp90, respectively. Rat cardiac tissues were examined histologically, and apoptosis was detected by terminal deoxynucleotidyl transferase dUTP nick end labeling staining. The expression of B-cell lymphoma-2 (Bcl-2), Bcl-2-associated X protein, Hsp90, p53 upregulated modulator of apoptosis, and p53 was measured by western blotting and real-time polymerase chain reaction. Caspase-3, caspase-8, and caspase-9 were detected by enzyme-linked immunosorbent assay. Rat cardiac myocyte damage induced by CLP was reduced by Gln treatment and Hsp90 overexpression, and these changes were reversed by Hsp90 knockdown. Bcl-2 expression, Bcl-2-associated X protein, p53, p53 upregulated modulator of apoptosis, caspase-8, caspase-9, and caspase-3 activities were significantly upregulated in the CLP model, which were reduced by Gln treatment and Hsp90 overexpression. Gln reduced apoptosis of cardiac myocytes in a rat model of sepsis, by promoting Hsp90 expression. Further studies are needed to determine the possible therapeutic action of Gln in sepsis in human tissue. Copyright © 2017 Elsevier Inc. All rights reserved.

Benzo[a]pyrene affects Jurkat T cells in the activated state via the antioxidant response element dependent Nrf2 pathway leading to decreased IL-2 secretion and redirecting glutamine metabolism

Energy Technology Data Exchange (ETDEWEB)

Murugaiyan, Jayaseelan; Rockstroh, Maxie; Wagner, Juliane [Department of Proteomics, Helmholtz-Centre for Environmental Research — UFZ, Permoserstr. 15, 04318 Leipzig (Germany); Baumann, Sven [Department of Metabolomics, Helmholtz-Centre for Environmental Research — UFZ, Permoserstr. 15, 04318 Leipzig (Germany); Schorsch, Katrin [Department of Proteomics, Helmholtz-Centre for Environmental Research — UFZ, Permoserstr. 15, 04318 Leipzig (Germany); Trump, Saskia; Lehmann, Irina [Department of Environmental Immunology, Helmholtz-Centre for Environmental Research — UFZ, Permoserstr. 15, 04318 Leipzig (Germany); Bergen, Martin von [Department of Proteomics, Helmholtz-Centre for Environmental Research — UFZ, Permoserstr. 15, 04318 Leipzig (Germany); Department of Environmental Immunology, Helmholtz-Centre for Environmental Research — UFZ, Permoserstr. 15, 04318 Leipzig (Germany); Department of Biotechnology, Chemistry and Environmental Engineering, Aalborg University, Aalborg (Denmark); Tomm, Janina M., E-mail: Janina.tomm@ufz.de [Department of Proteomics, Helmholtz-Centre for Environmental Research — UFZ, Permoserstr. 15, 04318 Leipzig (Germany)

2013-06-15

There is a clear evidence that environmental pollutants, such as benzo[a]pyrene (B[a]P), can have detrimental effects on the immune system, whereas the underlying mechanisms still remain elusive. Jurkat T cells share many properties with native T lymphocytes and therefore are an appropriate model to analyze the effects of environmental pollutants on T cells and their activation. Since environmental compounds frequently occur at low, not acute toxic concentrations, we analyzed the effects of two subtoxic concentrations, 50 nM and 5 μM, on non- and activated cells. B[a]P interferes directly with the stimulation process as proven by an altered IL-2 secretion. Furthermore, B[a]P exposure results in significant proteomic changes as shown by DIGE analysis. Pathway analysis revealed an involvement of the AhR independent Nrf2 pathway in the altered processes observed in unstimulated and stimulated cells. A participation of the Nrf2 pathway in the change of IL-2 secretion was confirmed by exposing cells to the Nrf2 activator tBHQ. tBHQ and 5 μM B[a]P caused similar alterations of IL-2 secretion and glutamine/glutamate metabolism. Moreover, the proteome changes in unstimulated cells point towards a modified regulation of the cytoskeleton and cellular stress response, which was proven by western blotting. Additionally, there is a strong evidence for alterations in metabolic pathways caused by B[a]P exposure in stimulated cells. Especially the glutamine/glutamate metabolism was indicated by proteome pathway analysis and validated by metabolite measurements. The detrimental effects were slightly enhanced in stimulated cells, suggesting that stimulated cells are more vulnerable to the environmental pollutant model compound B[a]P. - Highlights: • B[a]P affects the proteome of Jurkat T cells also at low concentrations. • Exposure to B[a]P (50 nM, 5 μM) did not change Jurkat T cell viability. • Both B[a]P concentrations altered the IL-2 secretion of stimulated cells. �

Free Amino Acid Enriched Rotifer for Larval Grouper Cromileptes altivelis (Pengkayaan Rotifer dengan Asam Amino Bebas Untuk Larva Kerapu Bebek Cromileptes altivelis

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Dedi Jusadi

2015-12-01

Full Text Available Pembenihan ikan kerapu dihadapkan pada rendahnya sintasan, terutama fase awal hidupnya. Rendahnya sintasan diduga berhubungan dengan belum berkembangnya organ pencernaan larva dan tidak tersedianya pakan yang siap diserap tubuh. Pemberian asam amino bebas seperti taurin dan glutamin melalui rotifer diharapkan dapat meningkatan ketersediaan nutrien yang dapat diserap dengan cepat oleh larva, sehingga sintasan larva tinggi dan dapat tumbuh lebih cepat. Penelitian bertujuan mengukur pengaruh glutamin atau taurin terhadap sintasan dan pertumbuhan larva kerapu bebek Cromileptes altivelis. Larva umur 1 hari (10 ekor.L-1 dipelihara dalam bak fiberglass volume 500 L yang diisi air laut sampai 330 L. Larva diberi pakan rotifer diperkaya 0,5 g glutamin, 0,5 g taurin, atau tanpa glutamin dan taurin. Larva dipelihara selama 16 hari dengan pemberian pakan 2 kali  per hari. Satu jam setelah pemberian pakan dilakukan pengamatan terhadap jumlah rotifer dalam saluran pencernaan larva ikan. Hasil penelitian menunjukkan jumlah rotifer dalam saluran pencernaan larva meningkat seiring dengan bertambahnya umur. Namun, jumlah rata-rata rotifer yang dikonsumsi larva pada perlakuan 0,5 g glutamin atau 0,5 g taurin lebih banyak dibanding perlakuan tanpa taurin dan glutamin. Larva yang diberi rotifer hasil pengkayaan dengan 0,5 g glutamin atau 0,5 g taurin memiliki sintasan yang tidak berbeda (P>0,05, masing-masing 19,2±2,25%, dan 24,5±1,20%, dan secara signifikan lebih banyak dibanding larva di perlakuan tanpa glutamin dan taurin yang nilainya 13,0±1,70%. Larva yang diberi rotifer hasil pengkayaan dengan 0,5 g taurin secara signifikan lebih panjang (5,5±0,18 mm dari ikan di perlakuan 0,5 g glutamin (5,3±0,12 mm. Demikian juga, larva di perlakuan glutamin lebih panjang dari pelakuan tanpa glutamin dan taurin (5,0±0,16 mm. Pengkayaan rotifer menggunakan asam amino bebas taurin atau glutamin dapat meningkatkan sintasan dan pertumbuhan larva kerapu bebek. Namun

Interactive effects of glutamine and gamma-aminobutyric acid on growth performance and skeletal muscle amino acid metabolism of 22-42-day-old broilers exposed to hot environment

Science.gov (United States)

Hu, Hong; Bai, Xi; Shah, Assar Ali; Dai, Sifa; Wang, Like; Hua, Jinling; Che, Chuanyan; He, Shaojun; Wen, Aiyou; Jiang, Jinpeng

2016-06-01

The present experiment was conducted to investigate the interactive effects between dietary glutamine (Gln, 0 and 5 g/kg) and gamma-aminobutyric acid (GABA, 0 and 100 mg/kg) on growth performance and amino acid (AA) metabolism of broilers under hot environment. A total of 360 22-day-old Arbor Acres male chickens were randomly assigned to five treatment groups under thermoneutral chamber (PC, 23 °C) and cyclic heat stress (HS, 30-34 °C cycling) conditions. Compared with the PC group, cyclic HS decreased ( P muscle at 28, 35, and 42 days, while it increased ( P muscle, the Gln supplementation increased ( P muscle Gln concentrations, glutaminase activities, GS activities at 28 and 35 days, and DWG, GABA concentrations, and GABA-T activities at 28, 35, and 42 days in broilers under cyclic HS. In conclusion, the present results indicated that the interactions of exogenous Gln and GABA could offer a potential nutritional strategy to prevent HS-related depression in skeletal muscle Gln and GABA metabolism of broilers.

Investigation of Cortical Glutamate–Glutamine and γ-Aminobutyric Acid in Obsessive–Compulsive Disorder by Proton Magnetic Resonance Spectroscopy

Science.gov (United States)

Simpson, Helen B; Shungu, Dikoma C; Bender, James; Mao, Xiangling; Xu, Xiaoyan; Slifstein, Mark; Kegeles, Lawrence S

2012-01-01

Glutamatergic abnormalities in corticostriatal brain circuits are thought to underlie obsessive–compulsive disorder (OCD). Whether these abnormalities exist in adults with OCD is not clear. We used proton magnetic resonance spectroscopy (1H MRS) to test our hypothesis that unmedicated adults with OCD have reduced glutamate plus glutamine (Glx) levels in the medial prefrontal cortex (MPFC) compared with healthy controls. Levels of γ-aminobutyric acid (GABA) were also explored. Twenty-four unmedicated adults with OCD and 22 matched healthy control subjects underwent 1H MRS scans at 3.0 T. Resonances of both Glx and GABA were obtained using the standard J-editing technique and assessed as ratios relative to voxel tissue water (W) in the MPFC (the region of interest) and the dorsolateral prefrontal cortex (DLPFC) to explore the regional specificity of any finding. In the MPFC, Glx/W did not differ by diagnostic group (p=0.98) or sex (p=0.57). However, GABA/W was decreased in OCD (2.16±0.46 × 10−3) compared with healthy controls (2.43±0.45 × 10−3, p=0.045); moreover, age of OCD onset was inversely correlated with MPFC GABA/W (r=−0.50, p=0.015). MPFC GABA/W was higher in females than in males. In the DLPFC, there were no main effects of diagnosis or gender on Glx/W or GABA/W. These data indicate that unmedicated adults with OCD do not have Glx abnormalities in a MPFC voxel that includes the pregenual anterior cingulate cortex. However, they may have decreased MPFC GABA levels. How GABA abnormalities might contribute to corticostriatal dysfunction in OCD deserves further study. PMID:22850733

How proteases from Enterococcus faecalis contribute to its resistance to short alpha-helical antimicrobial peptides

Czech Academy of Sciences Publication Activity Database

Nešuta, Ondřej; Buděšínský, Miloš; Hadravová, Romana; Monincová, Lenka; Humpolíčková, Jana; Čeřovský, Václav

2017-01-01

Roč. 75, č. 7 (2017), č. článku ftx091. ISSN 2049-632X R&D Projects: GA TA ČR(CZ) TA04010638; GA MZd(CZ) NV16-27726A Institutional support: RVO:61388963 Keywords : antimicrobial peptides * biofilm * C-terminal deamidation * gelatinase * protease Subject RIV: EE - Microbiology, Virology OBOR OECD: Microbiology Impact factor: 2.335, year: 2016

Human apolipoprotein B (apoB) mRNA: Identification of two distinct apoB mRNAs, an mRNA with the apoB-100 sequence and an apoB mRNA containing a premature in-frame translational stop codon, in both liver and intestine

International Nuclear Information System (INIS)

Higuchi, K.; Hospattankar, A.V.; Law, S.W.; Meglin, N.; Cortright, J.; Brewer, H.B. Jr.

1988-01-01

Human apolipoprotein B (apoB) is present in plasma as two separate isoproteins, designated apoB-100 (512 kDa) and apoB-48 (250 kDa). ApoB is encoded by a single gene on chromosome 2, and a single nuclear mRNA is edited and processed into two separate apoB mRNAs. A 14.1-kilobase apoB mRNA codes for apoB-100, and the second mRNA, which codes for apoB-48, contains a premature stop codon generated by a single base substitution of cytosine to uracil at nucleotide 6,538, which converts the translated CAA codon coding for the amino acid glutamine at residue 2,153 in apoB-100 to a premature in-frame stop codon (UAA). Two 30-base synthetic oligonucleotides, designated apoB-Stop and apoB-Gln, were synthesized containing the complementary sequence to the stop codon (UAA) and glutamine codon (CAA), respectively. The combined results from these studies establish that both human intestine and liver contain the two distinct apoB mRNAs, an mRNA that codes for apoB-100 and an apoB mRNA that contains the premature stop codon, which codes for apoB-48. The premature in-frame stop codon is not tissue specific and is present in both human liver and intestine

Effects of glutamine pretreatment on learning and memory in heat-exposed rats

Institute of Scientific and Technical Information of China (English)

Shenghao Zhao; Lei Wang; Qin Wang; Siyi Wang; Chundi Deng; Xianfei Xie; Youe Yan; Hui Wang

2008-01-01

BACKGROUND: Glutamine (Gln) pretreatment can protect neural cells from injuries due to heat, ischemia, hypoxia, endotoxemia, and inflammatory factors.OBJECTIVE: To observe the effects of Gln pretreatment on learning and memory, survival time, and rectal temperature in heat-exposed rats.DESIGN, TIME AND SETTING: The present randomized grouping, neurobehavioral experiment was performed at the Laboratory of Department of Pharmacology, Basic School of Medicine, Wuhan University between March and September 2007.MATERIALS: Twenty-four healthy, Wistar rats were included in this study. SPX-160B biochemistry incubator (Shanghai Experimental Equipment Co., Ltd., China), probe electronic thermometer (11000 type, Maikepai Science and Technology Co., Ltd., China), Y-type maze box used in conjunction with MG-2 maze stimulator (Zhangjiagang Biomedical Instrument Factory, China), L-Gin (Batch No. 061218, 5 g/bottle, prepared into 10% aqueous solution, Amresco Company, USA) were used.METHODS: Twenty-four rats were randomly and evenly divided into 3 groups: heat-exposed, Gln low-lose, and Gln high-dose. Following learning and memory testing with the Y-maze, rats in the heat-exposed group were subjected to heat injury (40.5-41.5℃) in a biochemistry incubator. Rectal temperature was measured every 5 minutes. Thirty-five minutes after heat exposure, rats were removed and placed in the Y-type maze to test learning and memory again. Subsequently, the rats were returned to the same environment of thermal stimulation until they died. Rat survival time was recorded. Subsequent to learning and memory testing, rats in the Gln low-dose and high-dose groups received an i.p. injection of Gln (0.4 g/kg and 0.8 g/kg, respectively), and were exposed to heat injury. The remaining experimental procedures remained the same as for the heat-exposed group.MAIN OUTCOME MEASURES: Rat learning and memory, rectal temperature, and survival time in heat exposure environment.RESULTS: (1) In the Y

Value and Limits of Routine Histology Alone or Combined with Glutamine Synthetase Immunostaining in the Diagnosis of Hepatocellular Adenoma Subtypes on Surgical Specimens

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Paulette Bioulac-Sage

2013-01-01

Full Text Available Immunohistochemistry is a valid method to classify hepatocellular adenoma (HCA. The aim was to test the performance of routine histology combined to glutamine synthetase (GS staining to identify the 2 major HCA subtypes: HNF1α inactivated (H-HCA and inflammatory HCA (IHCA. 114 surgical cases, previously classified by immunohistochemistry, were analysed. Group A comprised 45 H-HCAs, 44 IHCAs, and 9 β-catenin-activated IHCAs (b-IHCA, and group B, 16 b-HCA and unclassified HCA (UHCA. Steatosis was the hallmark of H-HCA. IHCA and b-IHCA were mainly characterized by inflammation, thick arteries, and sinusoidal dilatation; b-IHCA could not be differentiated from IHCA by routine histology. Group B was identified by default. A control set (91 cases was analyzed using routine and GS stainings (without knowing immunohistochemical results. Among the 45 H-HCAs and 27 IHCAs, 40 and 24 were correctly classified, respectively. Among the 10 b-IHCAs, 4 were identified as such using additional GS. Eight of the 9 HCAs that were neither H-HCA nor IHCA were correctly classified. Conclusion. Routine histology allows to diagnose >85% of the 2 major HCA subtypes. GS is essential to identify b-HCA. This study demonstrates that a “palliative” diagnostic approach can be proposed, when the panel of specific antibodies is not available.

Bovine proteins containing poly-glutamine repeats are often polymorphic and enriched for components of transcriptional regulatory complexes

LENUS (Irish Health Repository)

Whan, Vicki

2010-11-23

Abstract Background About forty human diseases are caused by repeat instability mutations. A distinct subset of these diseases is the result of extreme expansions of polymorphic trinucleotide repeats; typically CAG repeats encoding poly-glutamine (poly-Q) tracts in proteins. Polymorphic repeat length variation is also apparent in human poly-Q encoding genes from normal individuals. As these coding sequence repeats are subject to selection in mammals, it has been suggested that normal variations in some of these typically highly conserved genes are implicated in morphological differences between species and phenotypic variations within species. At present, poly-Q encoding genes in non-human mammalian species are poorly documented, as are their functions and propensities for polymorphic variation. Results The current investigation identified 178 bovine poly-Q encoding genes (Q ≥ 5) and within this group, 26 genes with orthologs in both human and mouse that did not contain poly-Q repeats. The bovine poly-Q encoding genes typically had ubiquitous expression patterns although there was bias towards expression in epithelia, brain and testes. They were also characterised by unusually large sizes. Analysis of gene ontology terms revealed that the encoded proteins were strongly enriched for functions associated with transcriptional regulation and many contributed to physical interaction networks in the nucleus where they presumably act cooperatively in transcriptional regulatory complexes. In addition, the coding sequence CAG repeats in some bovine genes impacted mRNA splicing thereby generating unusual transcriptional diversity, which in at least one instance was tissue-specific. The poly-Q encoding genes were prioritised using multiple criteria for their likelihood of being polymorphic and then the highest ranking group was experimentally tested for polymorphic variation within a cattle diversity panel. Extensive and meiotically stable variation was identified

Influence of glutamine on morphological and functional changes of liver in the presence of extrahepatic biliary obstruction in rats Influência da glutamina em alterações funcionais e morfológicas do fígado na vigência de obstrução biliar extra-hepática em ratos

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Manoel Camelo de Paiva Neto

2010-08-01

Full Text Available PURPOSE: To study the influence of glutamine on functional and morphological changes of liver in the extrahepatic biliary obstruction through an experimental model in rats. METHODS: Seventy Wistar rats were divided into four groups: control (group C fictitious operation, (group FO, submitted to laparotomy with handling of bile ducts, but without hepatic duct ligation, (group EBO submitted to laparotomy and hepatic duct ligation, one of them submitted to supplementation with glutamine 2% (group G. The control group consisted of 6 animals. The animals from groups FO, EBO and G were divided into three groups consisting of 6 animals each, being sacrificed at 7, 14 and 21 days after operation, respectively. Blood samples were collected for biochemical analysis and a fragment of liver tissue was collected from the middle lobe for histological analysis. RESULTS: Both for biochemical analysis (BT, aspartate and alanine aminotransferase AST, ALT and alkaline phosphatase FAL and for histopathological changes (fibrosis, portal inflammation, parenchymal inflammation, hepatocytic changes and duct proliferation, no statistical difference between groups submitted to extrahepatic biliary obstruction (EBO with and without treatment with glutamine (G was observed. CONCLUSION: Glutamine supplementation did not alter the prognosis of liver enzymes and histopathological changes in animals submitted to extrahepatic biliary obstruction.OBJETIVO: Estudar a influência da glutamina em alterações funcionais e morfológicas do fígado na obstrução biliar extra-hepática por meio de um modelo experimental desenvolvido em ratos. MÉTODOS: Setenta ratos Wistar distribuídos em quatro grupos: controle (grupo C; operação fictícia (grupo OF, submetido à laparotomia com manuseio das vias biliares, mas sem ligadura do ducto hepático; (grupo OBE, submetido à laparotomia exploradora e ligadura do ducto hepático, sendo um deles submetido à suplementação com glutamina a

Characterization of amino acid metabolism by cultured rat kidney cells: Study with 15N

International Nuclear Information System (INIS)

Nissim, I.; States, B.; Yudkoff, M.; Segal, S.

1987-01-01

The present study evaluates the metabolism of glutamine and glutamate by normal rat kidney (NRK) cells. The major aim was to evaluate the effect of acute acidosis on the metabolism of amino acid and ammonia formation by cultured NRK cells. Experiments at either pH 7.0 or 7.4 were conducted with phosphate-buffered saline supplemented with either 1 mM [5- 15 N]glutamine, [2- 15 N]glutamine, or [ 15 N]glutamate. Incubation with either glutamine or glutamate as a precursor showed that production of ammonia and glucose was increased significantly at pH 7.0 vs 7.4. In experiments with [5- 15 N]glutamine, the authors found that ∼57 and 43% of ammonia N was derived from 5-N of glutamine at pH 7.4 and 7.0, respectively. Three major metabolic pathways of [2- 15 N]glutamine or [ 15 N]glutamate disposal were identified: (1) transamination reactions involving the pH-independent formation of [ 15 N] aspartate and [ 15 N]alanine; (2) the synthesis of [6- 15 NH 2 ]adenine nucleotide, a process more active at pH 7.4 vs. 7.0; and (3) glutamine synthesis from [ 15 N]glutamate, especially at pH 7.4. The data indicate that NRK cells in culture consume glutamine and glutamate and generate ammonia and various amino acids, depending on the H + concentration in the media. The studies suggest that these cell lines may provide a useful model for studying various aspects of the effect of pH on rat renal ammoniagenesis

Effect of high-dose growth hormone and glutamine on body composition, urine creatinine excretion, fatty acid absorption, and essential fatty acids status in short bowel patients - A randomized, double-blind, crossover, placebo-controlled study

DEFF Research Database (Denmark)

Jeppesen, P.B.; Szkudlarek, J.; Høy, Carl-Erik

2001-01-01

Background: Positive effects of high dose growth hormone and glutamine (GH+GLN) on body composition in short bowel patients have been described. Lack of effects on intestinal absorption found in some studies has been ascribed to concomitant essential fatty acid (EFA) deficiency. This study...... describes changes in body weight (BW) and composition, 24-h urine creatinine excretion, intestinal fatty acid absorption (total, saturated, unsaturated and EFA), and EFA status in relation to treatment with GH+GLN in s short bowel patients. Methods: A double-blind, crossover study between placebo and growth...... with baseline. Twenty-four-hour urine creatinine excretion did not differ between study periods. No changes in intestinal absorption of fatty acids were seen, and no changes in EFAs measured in plasma phospholipids were observed. Only 1 of 8 patients, who did not receive parenteral lipids, had a Holman index...

Use of 13N in studies of fixation of dinitrogen and assimilation of ammonium by cyanobacteria

International Nuclear Information System (INIS)

Meeks, J.C.; Wolk, C.P.; Thomas, J.; Austin, S.M.; Galonsky, A.; Michigan State Univ., East Lansing

1978-01-01

13 N (tsub(1/2)=10min) has been used to identify the initial products of assimilation of N 2 and NH 4 + by intact filaments of a number of cyanobacteria and by heterocysts isolated from Anabaena cylindrica. Ammonium, the amide nitrogen of glutamine, and the α-amino nitrogen of glutamate, in that order, were the first observed products of fixation of [ 13 N]N 2 . Amide-labelled glutamine was the initial product of metabolism of 13 NH 4 + by A. cylindrica grown with either NH 4 + or N 2 as the nitrogen source. Glutamate was the second major product of 13 NH 4 + assimilation. Isolated heterocysts form [ 13 N]glutamine but not [ 13 N]glutamate from [ 13 N]N 2 or 13 NH 4 + . Formation of [ 13 N]glutamine from [ 13 N]N 2 was inhibited by acetylene, indicating metabolic coupling of the activity of glutamine synthetase to that of nitrogenase in these cells. A diffusible substance produced by heterocysts inhibits nearby cells of the same filament from differentiating into heterocysts. Glutamine (or a derivative of glutamine) may be involved in inhibiting differentiation of vegetative cells. (author)

Dysregulation of the Glutamine Transporter Slc38a3 (SNAT3 and Ammoniagenic Enzymes in Obese, Glucose-Intolerant Mice

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Stephanie M. Busque

2014-08-01

Full Text Available Background/Aims: Uric acid nephrolithiasis is prevalent among patients with type 2 diabetes and metabolic syndrome; it is correlated with an acidic urine and lower urinary ammonium excretion and is likely associated with insulin resistance. Insulin stimulates ammoniagenesis in renal cell lines via increased phosphate-dependent glutaminase (PDG activity and glutamine metabolism. Ammonium excretion into the proximal tubule is mediated at least in part by the Na+/H+-exchanger NHE3 and in the collecting duct involving the Rhesus protein RhCG. Here we tested, whether obesity and insulin resistance in a diet-induced mouse model could contribute to deranged ammonium excretion. Methods: Obesity was induced by diet in mice and the impact on key molecules of proximal tubular ammoniagenesis and urinary acid excretion tested. Results: Diet-induced obesity was confirmed by pathological intraperitoneal glucose tolerance tests (IPGTT. Three groups of mice were compared: control mice; obese, glucose-intolerant with abnormal IPGTT (O-GI; or moderate weight with normal IPGTT (Non-Responders, NR. Basal urinary ammonium excretion did not differ among groups. However, acid loading increased urinary ammonium excretion in all groups, but to a lesser extent in the O-GI group. SNAT3 mRNA expression was enhanced in both obese groups. PDG expression was elevated only in acid-loaded O-GI mice, whereas PEPCK was enhanced in both O-GI and NR groups given NH4CI. NHE activity in the brush border membrane of the proximal tubule was strongly reduced in the O-GI group whereas RhCG expression was similar. Conclusion: In sum, obesity and glucose intolerance impairs renal ammonium excretion in response to NH4CI feeding most likely through reduced NHE activity. The stimulation of SNAT3 and ammoniagenic enzyme expression may be compensatory but futile.

Intravenous Glutamine Administration Modulates TNF-α/IL-10 Ratio and Attenuates NFkB Phosphorylation in a Protein Malnutrition Model.

Science.gov (United States)

Santos, Andressa Cristina Antunes; Correia, Carolina Argondizo; de Oliveira, Dalila Cunha; Nogueira-Pedro, Amanda; Borelli, Primavera; Fock, Ricardo Ambrosio

2016-12-01

Protein malnutrition (PM) is a major public health problem in developing countries, affecting the inflammatory response and increasing susceptibility to opportunistic infections. For this reason, an adequate nutritional intervention can improve the quality of life of patients. Glutamine (GLN) is a nonessential amino acid, but can be considered "conditionally essential" for macrophage function in stress situations, in which it plays a role in the improvement of the inflammatory response. Concerning this issue, in the current study, it was of interest to evaluate some biological aspects of peritoneal cells from a protein malnutrition (PM) mouse model challenged with lipopolysaccharide (LPS) and treated intravenously with GLN. Two-month-old male Balb/c mice were subjected to a low-protein diet (2 % protein) and stimulated intravenously with LPS 1 h prior to the injection of 0.75 mg/kg GLN. Malnourished animals showed a reduced number of total peritoneal cells. Malnourished animals stimulated with LPS or LPS plus GLN did not show differences in peritoneal cell counts; however, the control group showed increased cellularity after LPS stimulus, which was reversed after GLN injection. Further, in the animals from both groups stimulated with LPS, GLN decreased the circulating levels of TNF-α and the levels of TNF-α produced by peritoneal cells; additionally, GLN decreased the IL-10 circulating levels in the malnourished animals stimulated with LPS. In addition, peritoneal cells of the control and malnourished groups stimulated with LPS showed a negative modulation of the NFkB signaling pathway after GLN injection. In conclusion, this study shows that GLN has the capacity to reduce TNF-α synthesis as well as to act as a negative regulator of NFkB phosphorylation, leading to a positive outcome in the control of TNF-α production.

Possible role of glutamine synthetase in the NO signaling response in root nodules by contributing to the antioxidant defenses

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Liliana Santos Silva

2013-09-01

Full Text Available Nitric oxide (NO is emerging as an important regulatory player in the Rhizobium-legume symbiosis. The occurrence of NO during several steps of the symbiotic interaction suggests an important, but yet unknown, signaling role of this molecule for root nodule formation and functioning. The identification of the molecular targets of NO is key for the assembly of the signal transduction cascade that will ultimately help to unravel NO function. We have recently shown that the key nitrogen assimilatory enzyme Glutamine Synthetase (GS is a molecular target of NO in root nodules of Medicago truncatula, being post-translationally regulated by tyrosine nitration in relation to nitrogen fixation. In functional nodules of M. truncatula NO formation has been located in the bacteroid containing cells of the fixation zone, where the ammonium generated by bacterial nitrogenase is released to the plant cytosol and assimilated into the organic pools by plant GS. We propose that the NO-mediated GS post-translational inactivation is connected to nitrogenase inhibition induced by NO and is related to metabolite channeling to boost the nodule antioxidant defenses. Glutamate, a substrate for GS activity is also the precursor for the synthesis of glutathione (GSH, which is highly abundant in root nodules of several plant species and known to play a major role in the antioxidant defense participating in the ascorbate/GSH cycle. Existing evidence suggests that upon NO-mediated GS inhibition, glutamate could be channeled for the synthesis of GSH. According to this hypothesis, GS would be involved in the NO-signaling responses in root nodules and the NO-signaling events would meet the nodule metabolic pathways to provide an adaptive response to the inhibition of symbiotic nitrogen fixation by reactive nitrogen species (RNS.

Binge Toluene Exposure Alters Glutamate, Glutamine and GABA in the Adolescent Rat Brain as Measured by Proton Magnetic Resonance Spectroscopy*

Science.gov (United States)

Perrine, Shane A.; O'Leary-Moore, Shonagh K.; Galloway, Matthew P.; Hannigan, John H.; Bowen, Scott E.

2010-01-01

Despite the high incidence of toluene abuse in adolescents, little is known regarding the effect of binge exposure on neurochemical profiles during this developmental stage. In the current study, the effects of binge toluene exposure during adolescence on neurotransmitter levels were determined using high-resolution proton magnetic resonance spectroscopy ex vivo at 11.7 T. Adolescent male Sprague-Dawley rats were exposed to toluene (0, 8,000 , or 12,000 ppm) for 15 min twice daily from postnatal day 28 (P28) through P34 and then euthanized either one or seven days later (on P35 or P42) to assess glutamate, glutamine, and GABA levels in intact tissue punches from the medial prefrontal cortex (mPFC), anterior striatum and hippocampus. In the mPFC, toluene reduced glutamate one day after exposure, with no effect on GABA, while after seven days, glutamate was no longer affected but there was an increase in GABA levels. In the hippocampus, neither GABA nor glutamate was altered one day after exposure, whereas seven days after exposure, increases were observed in GABA and glutamate. Striatal glutamate and GABA levels measured after either one or seven days were not altered after toluene exposure. These findings show that one week of binge toluene inhalation selectively alters these neurotransmitters in the mPFC and hippocampus in adolescent rats, and that some of these effects endure at least one week after the exposure. The results suggest that age-dependent, differential neurochemical responses to toluene may contribute to the unique behavioral patterns associated with drug abuse among older children and young teens. PMID:21126832