scholarly journals Adenosine production inside rat polymorphonuclear leucocytes

1981 ◽  
Vol 200 (2) ◽  
pp. 399-403 ◽  
Author(s):  
A C Newby ◽  
C A Holmquist
Keyword(s):  
Adenosine Deaminase ◽  
Metabolic Pathway ◽  
Metabolic Pathways ◽  
Adenosine Kinase ◽  
Extracellular Nucleotides ◽  
Polymorphonuclear Leucocytes ◽  
Intact Cells

Adenosine synthesis was studied during 2-deoxyglucose-induced ATP catabolism in intact rat polymorphonuclear leucocytes. When both adenosine kinase (EC 2.7.1.20) and adenosine deaminase (EC 3.5.4.4) were selectively inhibited, adenosine accumulated. Adenosine formation took place inside the intact cells by a metabolic pathway independent of the ecto-5′-nucleotidase (EC 3.1.3.5). Distinct metabolic pathways are proposed for adenosine production from intracellular or extracellular nucleotides.

scholarly journals Role of adenosine deaminase, ecto-(5'-nucleotidase) and ecto-(non-specific phosphatase) in cyanide-induced adenosine monophosphate catabolism in rat polymorphonuclear leucocytes

1980 ◽  
Vol 186 (3) ◽  
pp. 907-918 ◽  
Author(s):  
A C Newby
Keyword(s):  
Adenosine Deaminase ◽  
Adenine Nucleotides ◽  
Specific Inhibitor ◽  
Adenosine Monophosphate ◽  
Polymorphonuclear Leucocytes ◽  
Intact Cells ◽  
Endogenous Substrates ◽  
A Minor

1. The role of adenosine deaminase (EC 3.5.4.4), ecto-(5'-nucleotidase) (EC 3.1.3.5) and ecto-(non-specific phosphatase) in the CN-induced catabolism of adenine nucleotides in intact rat polymorphonuclear leucocytes was investigated by inhibiting the enzymes in situ. 2. KCN (10mM for 90 min) induced a 20-30% fall in ATP concentration accompanied by an approximately equimolar increase in hypoxanthine, ADP, AMP and adenosine concentrations were unchanged, and IMP and inosine remained undetectable (less than 0.05 nmol/10(7) cells). 3. Cells remained 98% intact, as judged by loss of the cytoplasmic enzyme lactate dehydrogenase (EC 1.1.1.27). 4. Pentostatin (30 microM), a specific inhibitor of adenosine deaminase, completely inhibited hypoxanthine production from exogenous adenosine (55 microM), but did not black CN-induced hypoxanthine production or cause adenosine accumulation in intact cells. This implied that IMP rather than adenosine was an intermediate in AMP breakdown in response to cyanide. 5. Antibodies raised against purified plasma-membrane 5'-nucleotidase inhibited the ecto-(5'-nucleotidase) by 95-98%. Non-specific phosphatases were blocked by 10 mM-sodium beta-glycerophosphate. 6. These two agents together blocked hypoxanthine production from exogenous AMP and IMP (200 microM) by more than 90%, but had no effect on production from endogenous substrates. 7. These data suggest that ectophosphatases do not participate in CN-induced catabolism of intracellular AMP in rat polymorphonuclear leucocytes. 8. A minor IMPase, not inhibited by antiserum, was detected in the soluble fraction of disrupted cells.

Enzymatic profiling of blood plasma and lymphocytes in systemic lupus erythematosus: focus on purine and pyrimidine metabolizing enzymes

2019 ◽  
pp. 48-54
Author(s):  
С.А. Бедина ◽  
А.С. Трофименко ◽  
Е.Э. Мозговая ◽  
И.А. Зборовская
Keyword(s):  
Adenosine Deaminase ◽  
Lupus Erythematosus ◽  
Metabolic Pathways ◽  
Purine Nucleoside Phosphorylase ◽  
Cytidine Deaminase ◽  
Adenosine Kinase ◽  
Purine Nucleoside ◽  
Dihydroorotate Dehydrogenase ◽  
Imp Dehydrogenase ◽  
Nucleoside Phosphorylase

Изучение метаболизма пуриновых и пиримидиновых оснований при системной красной волчанке в настоящее время является актуальным направлением, как с позиций фундаментальной науки, так и в аспекте разработки инновационных средств лечения. Не менее важным является и энзимное профилирование, поскольку именно ферменты - перспективные предикторы ответа на терапию и удобные «мишени» для терапевтических воздействий. Цель исследования - описание профиля активности ключевых ферментов пуринового и пиримидинового метаболизма в плазме крови и в лизатах циркулирующих лимфоцитов у больных системной красной волчанкой. Методика. В плазме крови и лизатах лимфоцитов 50 больных системной красной волчанкой определяли активность комплекса из 10 ферментов пуринового и пиримидинового метаболизма. В качестве контроля использовали образцы 30 здоровых лиц. Оценка степени активности проводилась с использованием шкалы индексов ECLAM. Выделение лимфоцитов из венозной периферической крови проводили c помощью метода седиментации в градиенте плотности. Результаты. У больных системной красной волчанкой была установлена зависимость активности ферментов пуринового пиримидинового метаболизма от тяжести заболевания. Прямые корреляционные связи с индексом ECLAM выявлены в плазменной активности пуриннуклеозидфосфорилазы, аденозинкиназы, урацил/тимидиндегидрогеназы, ИМФ-дегидрогеназы, цитидиндезаминазы, тимидинкиназы, дигидрооротатдегидрогеназы, а также у активности аденозинкиназы, ИМФ-дегидрогеназы и тимидинкиназы в лизатах лимфоцитов. Обратные корреляционные связи с индексом ECLAM выявлены для аденозиндезаминазы, тимидинфосфорилазы в плазме и активности пуриннуклеозидфосфорилазы, аденозиндезаминазы, гуанилаткиназы, урацил/тимидиндегидрогеназы, цитидиндезаминазы, тимидинфосфорилазы, дигидрооротатдегидрогеназы в лизатах лимфоцитов. При системной красной волчанке в плазме наиболее информативными оказались показатели минимальной активности пуриннуклеозидфосфорилазы, аденозинкиназы и ИМФ-дегидрогеназы, в лимфоцитах - пуриннуклеозидфосфорилазы, аденозиндезаминазы и аденозинкиназы. Заключение. Изученные энзимные показатели можно использовать в качестве дополнительных маркеров активности системной красной волчанке. Purine and pyrimidine metabolic pathways are emerging topical areas of research from the perspective of both basic science and development of innovative therapies for systemic lupus erythematosus (SLE). It is particularly important, therefore, to disclose characteristic enzymatic patterns for further prediction of the response to treatment. Objective: to characterize activity patterns of the major enzymes of purine and pyrimidine metabolic pathways in SLE. Methods. Samples were obtained from 50 patients with verified SLE and 30 healthy controls. Disease activity was assessed using the ECLAM scale. Blood lymphocytes were isolated by a standard density gradient centrifugation procedure. Activities of 10 major purine and pyrimidine enzymes were measured in blood plasma and lysed lymphocytes. Results. For different enzyme groups, enzyme activities directly or inversely correlated with SLE severity. Plasma purine nucleoside phosphorylase, adenosine kinase, uracil/thymidine dehydrogenase, IMP dehydrogenase, cytidine deaminase, thymidine kinase, dihydroorotate dehydrogenase, and lymphocyte adenosine kinase, IMP dehydrogenase, and thymidine kinase activities positively correlated with the ECLAM score. Negative correlations with ECLAM score were found for plasma adenosine deaminase and thymidine phosphorylase, and for lymphocyte purine nucleoside phosphorylase, adenosine deaminase, guanylate kinase, uracil/thymidine dehydrogenase, cytidine deaminase, thymidine phosphorylase, and dihydroorotate dehydrogenase. Activities of plasma purine nucleoside phosphorylase, adenosine kinase, IMP dehydrogenase, and lymphocyte purine nucleoside phosphorylase, adenosine deaminase, and adenosine kinase activities had the highest correlations with minimal SLE activity and represented candidate markers for the disease severity. Conclusion. The studied enzymatic patterns can be used as auxiliary markers of SLE activity, with special emphasis on minimal disease activity.

scholarly journals The control of adenosine concentration in polymorphonuclear leucocytes, cultured heart cells and isolated perfused heart from the rat

1983 ◽  
Vol 214 (2) ◽  
pp. 317-323 ◽  
Author(s):  
A C Newby ◽  
C A Holmquist ◽  
J Illingworth ◽  
J D Pearson
Keyword(s):  
Adenine Nucleotide ◽  
Maximal Activity ◽  
Adenosine Kinase ◽  
Neonatal Rat ◽  
Heart Cells ◽  
Polymorphonuclear Leucocytes ◽  
Perfused Heart ◽  
Intact Cells ◽  
Adenosine Concentration ◽  
Rat Heart Cells

Rat polymorphonuclear leucocytes or neonatal-rat heart cells in culture were treated with 2′-deoxycoformycin and 5-iodotubercidin at concentrations that inhibited adenosine deaminase (EC 3.5.4.4) and adenosine kinase (EC 2.7.1.20) inside the intact cells, and the rate of adenosine accumulation was determined. The basal rate of adenosine formation was 2% (polymorphonuclear leucocytes) or 9% (heart cells) of the maximal activity of adenosine kinase also measured in intact cells. Greatly increased rates of adenosine formation were observed during adenine nucleotide catabolism. This condition also led to a decrease in adenosine kinase activity. When isolated rat hearts were perfused with 5-iodotubercidin alone at a concentration which inhibited adenosine kinase, no increase in tissue or perfusate adenosine or inosine concentration was observed. However, perfusion with hypoxic buffer or infusion of adenosine into the coronary circulation at a rate (20 nmol/min) equivalent to 40% of the activity of adenosine kinase caused large increases in effluent perfusate adenosine and inosine concentrations. These data argue unanimously against the existence of a substrate cycle controlling adenosine concentration. They suggest instead that an increase in the rate of adenosine formation is the principal cause of elevations in adenosine concentration during ATP catabolism.

scholarly journals Nucleotidase Cascades Are Catalyzed by Secreted Proteins of the Parasitic Nematode Trichinella spiralis

2002 ◽  
Vol 70 (9) ◽  
pp. 4917-4924 ◽  
Author(s):  
Kleoniki Gounaris
Keyword(s):  
Molecular Mass ◽  
Adenosine Deaminase ◽  
Parasitic Nematode ◽  
Trichinella Spiralis ◽  
Purinergic Signaling ◽  
Physiological Role ◽  
Apparent Molecular Mass ◽  
Extracellular Nucleotides ◽  
Secreted Proteins ◽  
Mediated Effects

ABSTRACT Extracellular nucleotides are signaling molecules whose receptor-mediated effects are involved in a variety of physiological responses in mammalian tissues. An overwhelming body of data indicate that inflammatory and other immune responses can be modulated by the availability and local concentrations of nucleotides via nucleotide receptor signaling, but this is only just beginning to be investigated in the context of infectious disease. Evidence is provided here that the parasitic nematode Trichinella spiralis can catalyze the conversion and thus modulate both the availability and concentration of extracellular nucleotides by means of the following secreted exoenzymes: apyrase, 5′-nucleotidase, and adenosine deaminase. These enzymes were characterized in terms of substrate specificity, kinetic behavior, pH, divalent cation preferences, and response to a series of compounds. The secreted 5′-nucleotidase was identified as a protein with an apparent molecular mass of 67 kDa after N-terminal amino acid sequencing of the purified protein. The presence of adenosine deaminase was confirmed in the secreted products by Western blotting with an antibody against a mammalian enzyme, as a protein with an apparent molecular mass of 38 kDa. These secreted proteins constitute an enzymatic cascade which catalyzes the degradation of extracellular nucleotides, with a potential physiological role in the regulation of purinergic signaling.

IDENTIFYING RELEVANT PATHWAYS AND BIOMARKERS IN CROHN’S DISEASE USING CONTEXTUALIZED METABOLIC NETWORK MODEL

2021 ◽  
Vol 27 (Supplement_1) ◽  
pp. S9-S10
Author(s):  
Brooklyn McGrew ◽  
Aman Shrivastava ◽  
Philip Fernandes ◽  
Lubaina Ehsan ◽  
Yash Sharma ◽  
...  
Keyword(s):  
Gene Expression ◽  
Crohn’S Disease ◽  
Fatty Acid ◽  
Crohn's Disease ◽  
Fatty Acid Synthesis ◽  
Metabolic Pathway ◽  
Metabolic Pathways ◽  
Acid Synthesis ◽  
Transcriptomic Data ◽  
Context Specific

Abstract Background Candidate markers for Crohn’s Disease (CD) may be identified via gene expression-based construction of metabolic networks (MN). These can computationally describe gene-protein-reaction associations for entire tissues and also predict the flux of reactions (rate of turnover of specific molecules via a metabolic pathway). Recon3D is the most comprehensive human MN to date. We used publicly available CD transcriptomic data along with Recon3D to identify metabolites as potential diagnostic and prognostic biomarkers. Methods Terminal ileal gene expression profiles (36,372 genes; 218 CD. 42 controls) from the RISK cohort (Risk Stratification and Identification of Immunogenetic and Microbial Markers of Rapid Disease Progression in Children with Crohn’s Disease) and their transcriptomic abundances were used. Recon3D was pruned to only include RISK dataset transcripts which determined metabolic reaction linkage with transcriptionally active genes. Flux balance analysis (FBA) was then run using RiPTiDe with context specific transcriptomic data to further constrain genes (Figure 1). RiPTiDe was independently run on transcriptomic data from both CD and controls. From the pruned and constricted MN obtained, reactions were extracted for further analysis. Results After applying the necessary constraints to modify Recon3D, 527 CD and 537 control reactions were obtained. Reaction comparison with a publicly available list of healthy small intestinal epithelial reactions (n=1282) showed an overlap of 80 CD and 84 control reactions. These were then further grouped based on their metabolic pathways. RiPTiDe identified context specific metabolic pathway activity without supervision and the percentage of forward, backward, and balanced reactions for each metabolic pathway (Figure 2). The metabolite concentrations in the small intestine was altered among CD patients. Notably, the citric acid cycle and malate-aspartate shuttle were affected, highlighting changes in mitochondrial metabolic pathways. This is illustrated by changes in the number of reactions at equilibrium between CD and control. Conclusions The results are relevant as cytosolic acetyl-CoA is needed for fatty acid synthesis and is obtained by removing citrate from the citric acid cycle. An intermediate removal from the cycle has significant cataplerotic effects. The malate-aspartate shuttle also allows electrons to move across the impermeable membrane in the mitochondria (fatty acid synthesis location). These findings are reported by previously published studies where gene expression for fatty acid synthesis is altered in CD patients along with mitochondrial metabolic pathway changes, resulting in altered cell homeostasis. In-depth analysis is currently underway with our work supporting the utility of potential metabolic biomarkers for CD diagnosis, management and improved care.

Renal interstitial adenosine metabolism during ischemia in dogs

2001 ◽  
Vol 280 (2) ◽  
pp. F231-F238 ◽  
Author(s):  
Akira Nishiyama ◽  
Shoji Kimura ◽  
Hong He ◽  
Katsuyuki Miura ◽  
Matlubur Rahman ◽  
...  
Keyword(s):  
Adenosine Deaminase ◽  
Adenosine Kinase ◽  
The Other ◽  
Local Inhibition ◽  
Other Hand ◽  
Adenosine Concentration ◽  
Anesthetized Dogs ◽  
Fluorometric Analysis

The present study was conducted to determine the metabolism of renal interstitial adenosine under resting conditions and during ischemia. By using a microdialysis method with HPLC-fluorometric analysis, renal interstitial concentrations of adenosine, inosine, and hypoxanthine were assessed in pentobarbital-anesthetized dogs. Average basal renal interstitial concentrations of adenosine, inosine, and hypoxanthine were 0.18 ± 0.04, 0.31 ± 0.05, and 0.35 ± 0.05 μmol/l, respectively. Local inhibition of adenosine kinase with iodotubercidin (10 μmol/l in perfusate) or inhibition of adenosine deaminase with erythro-9-(2-hydroxy-3-nonyl)adenine (EHNA; 100 μmol/l in perfusate) did not change adenosine concentrations in the nonischemic kidneys (0.18 ± 0.04 and 0.24 ± 0.05 μmol/l, respectively). On the other hand, treatment with iodotubercidin+EHNA significantly increased adenosine concentration (0.52 ± 0.07 μmol/l) with significant decreases in inosine and hypoxanthine levels (0.13 ± 0.03 and 0.19 ± 0.04 μmol/l, respectively). During 30 min of ischemia, adenosine, inosine, and hypoxanthine were significantly increased to 0.76 ± 0.29, 2.14 ± 0.45, and 21.8 ± 4.7 μmol/l, respectively. The treatment with iodotubercidin did not alter ischemia-induced increase in adenosine (0.84 ± 0.18 μmol/l); however, EHNA alone markedly enhanced adenosine accumulation (13.54 ± 2.16 μmol/l), the value of which was not augmented by an addition of iodotubercidin (15.80 ± 1.24 μmol/l). In contrast, ischemia-induced increases in inosine and hypoxanthine were inversely diminished by the treatment with iodotubercidin+EHNA (0.90 ± 0.20 and 9.86 ± 1.96 μmol/l, respectively). These results suggest that both adenosine kinase and adenosine deaminase contribute to the metabolism of renal interstitial adenosine under resting conditions, whereas adenosine produced during ischemia is mainly metabolized by adenosine deaminase and the rephosphorylation of adenosine by adenosine kinase is small.

scholarly journals Activities and some properties of 5′-nucleotidase, adenosine kinase and adenosine deaminase in tissues from vertebrates and invertebrates in relation to the control of the concentration and the physiological role of adenosine

1978 ◽  
Vol 174 (3) ◽  
pp. 965-977 ◽  
Author(s):  
J R S Arch ◽  
E A Newsholme
Keyword(s):  
Adenosine Deaminase ◽  
Physiological Role ◽  
Adenosine Kinase ◽  
British Library ◽  
Adenosine Concentration ◽  
Effects Of Ph ◽  
The Difference ◽  
Low Activity

1. The maximal activities of 5′-nucleotidase, adenosine kinase and adenosine deaminase together with the Km values for their respective substrates were measured in muscle, nervous tissue and liver from a large range of animals to provide information on the mechanism of control of adenosine concentration in the tissues. 2. Detailed evidence that the methods used were optimal for the extraction and assay of these enzymes has been deposited as Supplementary Publication SUP 50088 (16pages) at the British Library Lending Division, Boston Spa, Wetherby, West Yorkshire LS23 7BQ, U.K.,from whom copies can be obtained on the terms indicated in Biochem. J. (1978), 169, 5. This evidence includes the effects of pH and temperature on the activities of the enzymes. 3. In many tissues, the activities of 5′-nucleotidase were considerably higher than the sum of the activities of adenosine kinase and deaminase, which suggests that the activity of the nucleotidase must be markedly inhibited in vivo so that adenosine does not accumulate. In the tissues in which comparison is possible, the Km of the nucleotidase is higher than the AMP content of the tissue, and since some of the latter may be bound within the cell, the low concentration of substrate may, in part, be responsible for a low activity in vivo. 4. In most tissues and animals investigated, the values of the Km of adenosine kinase for adenosine are between one and two orders of magnitude lower than those for the deaminase. It is suggested that 5′-nucleotidase and adenosine kinase are simultaneously active so that a substrate cycle between AMP and adenosine is produced: the difference in Km values between kinase and deaminase indicates that, via the cycle, small changes in activity of kinase or nucleotidase produce large changes in adenosine concentration. 5. The activities of adenosine kinase or deaminase from vertebrate muscles are inversely correlated with the activities of phosphorylase in these muscles. Since the magnitude of the latter activities are indicative of the anaerobic nature of muscles, this negative correlation supports the hypothesis that an important role of adenosine is the regulation of blood flow in the aerobic muscles.

scholarly journals Transcriptome analysis of two inflorescence branching mutants reveals cytokinin is an important regulator in controlling inflorescence architecture in the woody plant Jatropha curcas

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Mao-Sheng Chen ◽  
Mei-Li Zhao ◽  
Gui-Juan Wang ◽  
Hui-Ying He ◽  
Xue Bai ◽  
...  
Keyword(s):  
Transcriptome Analysis ◽  
Metabolic Pathway ◽  
Jatropha Curcas ◽  
Woody Plant ◽  
Regulatory Mechanism ◽  
Adenosine Kinase ◽  
Inflorescence Architecture ◽  
Inflorescence Development ◽  
Order Branch ◽  
Important Regulator

Abstract Background In higher plants, inflorescence architecture is an important agronomic trait directly determining seed yield. However, little information is available on the regulatory mechanism of inflorescence development in perennial woody plants. Based on two inflorescence branching mutants, we investigated the transcriptome differences in inflorescence buds between two mutants and wild-type (WT) plants by RNA-Seq to identify the genes and regulatory networks controlling inflorescence architecture in Jatropha curcas L., a perennial woody plant belonging to Euphorbiaceae. Results Two inflorescence branching mutants were identified in germplasm collection of Jatropha. The duo xiao hua (dxh) mutant has a seven-order branch inflorescence, and the gynoecy (g) mutant has a three-order branch inflorescence, while WT Jatropha has predominantly four-order branch inflorescence, occasionally the three- or five-order branch inflorescences in fields. Using weighted gene correlation network analysis (WGCNA), we identified several hub genes involved in the cytokinin metabolic pathway from modules highly associated with inflorescence phenotypes. Among them, Jatropha ADENOSINE KINASE 2 (JcADK2), ADENINE PHOSPHORIBOSYL TRANSFERASE 1 (JcAPT1), CYTOKININ OXIDASE 3 (JcCKX3), ISOPENTENYLTRANSFERASE 5 (JcIPT5), LONELY GUY 3 (JcLOG3) and JcLOG5 may participate in cytokinin metabolic pathway in Jatropha. Consistently, exogenous application of cytokinin (6-benzyladenine, 6-BA) on inflorescence buds induced high-branch inflorescence phenotype in both low-branch inflorescence mutant (g) and WT plants. These results suggested that cytokinin is an important regulator in controlling inflorescence branching in Jatropha. In addition, comparative transcriptome analysis showed that Arabidopsis homologous genes Jatropha AGAMOUS-LIKE 6 (JcAGL6), JcAGL24, FRUITFUL (JcFUL), LEAFY (JcLFY), SEPALLATAs (JcSEPs), TERMINAL FLOWER 1 (JcTFL1), and WUSCHEL-RELATED HOMEOBOX 3 (JcWOX3), were differentially expressed in inflorescence buds between dxh and g mutants and WT plants, indicating that they may participate in inflorescence development in Jatropha. The expression of JcTFL1 was downregulated, while the expression of JcLFY and JcAP1 were upregulated in inflorescences in low-branch g mutant. Conclusions Cytokinin is an important regulator in controlling inflorescence branching in Jatropha. The regulation of inflorescence architecture by the genes involved in floral development, including TFL1, LFY and AP1, may be conservative in Jatropha and Arabidopsis. Our results provide helpful information for elucidating the regulatory mechanism of inflorescence architecture in Jatropha.

scholarly journals Metabolic Pathway Genes Associated with Susceptibility Genes to Coronary Artery Disease

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Heng Lu ◽  
Yi Chen ◽  
Linlin Li
Keyword(s):  
Coronary Artery Disease ◽  
Coronary Artery ◽  
Metabolic Pathway ◽  
Metabolic Pathways ◽  
Blood Lipids ◽  
Single Gene ◽  
Susceptibility Genes ◽  
Metabolic Factors ◽  
Citrate Cycle ◽  
Artery Disease

Coronary artery disease (CAD) is one of the leading threats to global health. Previous research has proven that metabolic pathway disorders, such as high blood lipids and diabetes, are one of the risk factors that mostly cause CAD. However, the crosstalk between metabolic pathways and CAD was mostly studied on physiology processes by analyzing a single gene function. A canonical correlation analysis was used to identify the metabolic pathways, which were integrated as a unit to coexpress with CAD susceptibility genes, and to resolve additional metabolic factors that are related to CAD. Seven pathways, including citrate cycle, ubiquinone, terpenoid quinone biosynthesis, and N-glycan biosynthesis, were identified as an integrated unit coexpressed with CAD genes. These pathways could not be revealed as a coexpressed pathway through traditional methods as each single gene has weak correlation. Furthermore, sets of genes in these pathways were candidate markers for diagnosis and detection from patients’ serum.

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