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1.
Eur J Med Chem ; 186: 111883, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31761385

RESUMO

As part of a continuing study, we designed and synthesized four series of 1-phenylimidazole-4-carboxylic acid derivatives as xanthine oxidoreductase (XOR) inhibitors, evaluated their in vitro inhibitory potencies against XOR and hypouricemic effects in mice, and determined their structure-activity relationships (SARs). Most of the compounds exhibited in vitro XOR inhibition at the nanomolar level. In comparison to febuxostat (half-maximal inhibitory concentration [IC50] value of 7.0 nM), compounds Ie and IVa exhibited the most promising XOR inhibitory effects with IC50 values of 8.0 and 7.2 nM, respectively. In the potassium oxonate/hypoxanthine-induced acute and long-term hyperuricemia mouse models, compounds Ie and IVa displayed significant hypouricemic potencies (P < 0.05), that were slightly weaker than and similar to febuxostat, respectively. More interestingly, both compounds showed a capacity to improve kidney damage by decreasing creatinine and urea nitrogen levels compared to the long-term hyperuricemia mouse group (P < 0.05), while febuxostat showed no significant effect.


Assuntos
Ácidos Carboxílicos/farmacologia , Inibidores Enzimáticos/farmacologia , Imidazóis/farmacologia , Xantina Desidrogenase/antagonistas & inibidores , Animais , Ácidos Carboxílicos/síntese química , Ácidos Carboxílicos/química , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Hiperuricemia/induzido quimicamente , Hiperuricemia/tratamento farmacológico , Hiperuricemia/metabolismo , Imidazóis/síntese química , Imidazóis/química , Camundongos , Camundongos Endogâmicos ICR , Modelos Moleculares , Estrutura Molecular , Relação Estrutura-Atividade , Xantina Desidrogenase/metabolismo
2.
Nat Commun ; 10(1): 4904, 2019 10 28.
Artigo em Inglês | MEDLINE | ID: mdl-31659168

RESUMO

Xanthine oxidoreductase has been implicated in cancer. Nonetheless, the role played by its two convertible forms, xanthine dehydrogenase (XDH) and oxidase (XO) during tumorigenesis is not understood. Here we produce XDH-stable and XO-locked knock-in (ki) mice to address this question. After tumor transfer, XO ki mice show strongly increased tumor growth compared to wild type (WT) and XDH ki mice. Hematopoietic XO expression is responsible for this effect. After macrophage depletion, tumor growth is reduced. Adoptive transfer of XO-ki macrophages in WT mice increases tumor growth. In vitro, XO ki macrophages produce higher levels of reactive oxygen species (ROS) responsible for the increased Tregs observed in the tumors. Blocking ROS in vivo slows down tumor growth. Collectively, these results indicate that the balance of XO/XDH plays an important role in immune surveillance of tumor development. Strategies that inhibit the XO form specifically may be valuable in controlling cancer growth.


Assuntos
Neoplasias/enzimologia , Xantina Desidrogenase/genética , Xantina Oxidase/genética , Animais , Proliferação de Células , Feminino , Técnicas de Introdução de Genes , Humanos , Macrófagos/enzimologia , Macrófagos/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Neoplasias/genética , Neoplasias/metabolismo , Neoplasias/fisiopatologia , Espécies Reativas de Oxigênio/metabolismo , Xantina Desidrogenase/metabolismo , Xantina Oxidase/metabolismo
3.
Plant Physiol Biochem ; 143: 364-374, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31542638

RESUMO

Xanthine dehydrogenase (XDH) is essential for the assimilation of symbiotically fixed nitrogen in ureidic legumes. Uric acid, produced in the reaction catalyzed by XDH, is the precursor of the ureides, allantoin and allantoate, which are the main N-transporting molecules in these plants. XDH and uric acid have been reported to be involved in the response to stress, both in plants and animals. However, the physiological role of XDH under stressful conditions in ureidic legumes remains largely unexplored. In vitro assays showed that Phaseolus vulgaris XDH (PvXDH) can behave as a dehydrogenase or as an oxidase. Therefore, it could potentially protect against oxidative radicals or, in contrast, it could increase their production. In silico analysis of the upstream genomic region of XDH coding gene from P. vulgaris revealed the presence of several stress-related cis-regulatory elements. PvXDH mRNA and enzymatic activity in plants treated with stress-related phytohormones or subjected to dehydration and stressful temperatures showed several fold induction. However, PvXDH activity was in vivo and in vitro inhibited by nitric oxide in leaves but not in nodules. In extracts from RNAi PvXDH silenced nodules, with lower levels of uric acid, XDH activity was inhibited by SNP which indicates that uric acid produced by XDH in the nodules of this ureidic legume could help to protect XDH against the inhibitory effects of nitric oxide.


Assuntos
Óxido Nítrico/metabolismo , Phaseolus/metabolismo , Folhas de Planta/metabolismo , Ácido Úrico/metabolismo , Xantina Desidrogenase/metabolismo , Regulação da Expressão Gênica de Plantas , Phaseolus/genética , Xantina Desidrogenase/genética
5.
Artigo em Inglês | MEDLINE | ID: mdl-30822215

RESUMO

This report presents the substrate inhibitory effect of xanthine (XN) on microbial growth and optimisation of effective parameters to achieve high enzyme activity of xanthine oxidoreductase (XOR) through statistical design. Three efficient isolated strains (Pseudomonas aeruginosa CEBP1 and CEBP2, Pseudomonas sp. CEB1G) were screened for growth kinetic studies. Substrate inhibitory models (eg. Aiba, Edward) could explain the growth kinetics of CEBP1, CEBP2 and CEB1G very well with various initial [XN] (S0), e.g., 0.1-35 g L-1. Highest XOR activity was obtained at stationary phase when biomass yield was high. Highest catalytic efficiency (kcat/KM) of XOR was obtained by CEBP1 at optimum specific growth rate of 0.082 h-1 and biomass yield of 0.196 g g-1 at S0 = 5 g L-1. The effects of S0, pH and temperature were studied by Box-Behnken experimental design to evaluate the interactive effects of the significant variables influencing XOR production by CEBP1. ANOVA with high correlation coefficient (R2 > 0.99) and lower 'Prob > F'value (< 0.05) validated the second order polynomial model for the enzyme production. The highest XOR activity of 31.2 KU min-1 mg-1 was achieved by CEBP1 under optimised conditions (35 °C; S0=5 g L-1; pH = 7.0) as compared to any report in literature. A sevenfold substrate affinity of the enzyme was observed after purification.


Assuntos
Engenharia Metabólica , Modelos Teóricos , Pseudomonas/crescimento & desenvolvimento , Pseudomonas/metabolismo , Xantina Desidrogenase/biossíntese , Animais , Biomassa , Reatores Biológicos/microbiologia , Reatores Biológicos/normas , Calibragem , Catálise , Interpretação Estatística de Dados , Cinética , Engenharia Metabólica/métodos , Engenharia Metabólica/normas , Engenharia Metabólica/estatística & dados numéricos , Oxirredução , Projetos de Pesquisa , Xantina Desidrogenase/metabolismo
6.
Int J Mol Sci ; 20(5)2019 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-30845710

RESUMO

In a previous study on chromate toxicity, an increase in the 2Fe2S electron paramagnetic resonance (EPR) signal from mitochondria was found upon addition of chromate to human bronchial epithelial cells and bovine airway tissue ex vivo. This study was undertaken to show that a chromate-induced increase in the 2Fe2S EPR signal is a general phenomenon that can be used as a low-temperature EPR method to determine the maximum concentration of 2Fe2S centers in mitochondria. First, the low-temperature EPR method to determine the concentration of 2Fe2S clusters in cells and tissues is fully developed for other cells and tissues. The EPR signal for the 2Fe2S clusters N1b in Complex I and/or S1 in Complex II and the 2Fe2S cluster in xanthine oxidoreductase in rat liver tissue do not change in intensity because these clusters are already reduced; however, the EPR signals for N2, the terminal cluster in Complex I, and N4, the cluster preceding the terminal cluster, decrease upon adding chromate. More surprising to us, the EPR signals for N3, the cluster preceding the 2Fe2S cluster in Complex I, also decrease upon adding chromate. Moreover, this method is used to obtain the concentration of the 2Fe2S clusters in white blood cells where the 2Fe2S signal is mostly oxidized before treatment with chromate and becomes reduced and EPR detectable after treatment with chromate. The increase of the g = 1.94 2Fe2S EPR signal upon the addition of chromate can thus be used to obtain the relative steady-state concentration of the 2Fe2S clusters and steady-state concentration of Complex I and/or Complex II in mitochondria.


Assuntos
Brônquios/química , Cromatos/efeitos adversos , Fígado/química , Mitocôndrias/química , Animais , Brônquios/citologia , Brônquios/efeitos dos fármacos , Bovinos , Linhagem Celular Tumoral , Espectroscopia de Ressonância de Spin Eletrônica , Complexo I de Transporte de Elétrons/metabolismo , Complexo II de Transporte de Elétrons/metabolismo , Células Epiteliais/citologia , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Humanos , Fígado/efeitos dos fármacos , Camundongos , Mitocôndrias/efeitos dos fármacos , Ratos , Xantina Desidrogenase/metabolismo
7.
Toxicol Appl Pharmacol ; 366: 17-24, 2019 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-30684528

RESUMO

Ryanodine receptors have an important role in the regulation of intracellular calcium levels in the nervous system and muscle. It has been described that ryanodine receptors influence keratinocyte differentiation and barrier homeostasis. Our goal was to examine the role of ryanodine receptors in the healing of full-thickness dermal wounds by means of in vitro and in vivo methods. The effect of ryanodine receptors on wound healing, microcirculation and inflammation was assessed in an in vivo mouse wound healing model, using skin fold chambers in the dorsal region, and in HaCaT cell scratch wound assay in vitro. SKH-1 mice were subjected to sterile saline (n = 36) or ryanodine receptor agonist 4-chloro-m-cresol (0.5 mM) (n = 42) or ryanodine receptor antagonist dantrolene (100 µM) (n = 42). Application of ryanodine receptor agonist 4-chloro-m-cresol did not influence the studied parameters significantly, whereas ryanodine receptor antagonist dantrolene accelerated the wound closure. Inhibition of the calcium channel also increased the vessel diameters in the wound edges during the process of healing and increased the blood flow in the capillaries at all times of measurement. Furthermore, application of dantrolene decreased xanthine-oxidoreductase activity during the inflammatory phase of wound healing. Inhibition of ryanodine receptor-mediated effects positively influence wound healing. Thus, dantrolene may be of therapeutic potential in the treatment of wounds.


Assuntos
Bloqueadores dos Canais de Cálcio/farmacologia , Dantroleno/farmacologia , Queratinócitos/efeitos dos fármacos , Canal de Liberação de Cálcio do Receptor de Rianodina/efeitos dos fármacos , Pele/efeitos dos fármacos , Cicatrização/efeitos dos fármacos , Ferimentos Penetrantes/tratamento farmacológico , Animais , Velocidade do Fluxo Sanguíneo , Sinalização do Cálcio/efeitos dos fármacos , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Modelos Animais de Doenças , Humanos , Queratinócitos/metabolismo , Queratinócitos/patologia , Masculino , Camundongos Pelados , Microcirculação/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Canal de Liberação de Cálcio do Receptor de Rianodina/metabolismo , Pele/irrigação sanguínea , Pele/lesões , Pele/metabolismo , Fatores de Tempo , Ferimentos Penetrantes/metabolismo , Ferimentos Penetrantes/patologia , Ferimentos Penetrantes/fisiopatologia , Xantina Desidrogenase/metabolismo
8.
Insect Biochem Mol Biol ; 105: 43-50, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30610924

RESUMO

During nitrogen metabolism, animals convert toxic ammonia to less toxic forms. Uric acid (UA) is an end product of this process in terrestrial insects. In lepidopteran larvae, a large amount of UA is stored in the integument via a phenomenon known as storage excretion. Physiologically, integumental UA plays crucial roles as a barrier against sunlight and as a white pigment for larval pigmentation patterns. Conventionally, UA is thought to be synthesized in the fat body, the insect equivalent of the liver of vertebrates, and to be transported to the epidermis via the hemolymph. Here, we reconsidered the conventional theory by a mosaic analysis targeting genes governing UA synthesis, using CRISPR/Cas9 mutagenesis and a traditional genetic method in Bombyx mori. Notably, we observed mosaic larvae in which the integument comprised both UA-containing white and UA-lacking translucent areas, indicating that UA synthesis in the epidermis is indispensable to the accumulation of a large amount of highly insoluble UA in the epidermis. Our results thus provide a genetic basis for storage excretion wherein lepidopteran insects use nitrogenous waste to adapt to their environment.


Assuntos
Bombyx/metabolismo , Nitrogênio/metabolismo , Ácido Úrico/metabolismo , Animais , Bombyx/genética , Proteínas de Transporte/metabolismo , Coenzimas/metabolismo , Feminino , Masculino , Proteínas de Membrana/metabolismo , Metaloproteínas/metabolismo , Pteridinas/metabolismo , Pele/metabolismo , Xantina Desidrogenase/metabolismo
9.
Redox Biol ; 21: 101070, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30576922

RESUMO

Obesity and related pathologies such as diabetes and metabolic syndrome are associated with chronic inflammation and cancer. The serum level of xanthine oxidoreductase (XOR) is correlated to obesity-associated metabolic disorders. XOR can play a role in the pathogenesis of both metabolic syndrome and cancer through the inflammatory response and the oxidative stress elicited by the products of its activity. The reactive oxygen and nitrogen species and the uric acid derived from XOR concur to the development of hypertension, dyslipidemia and insulin resistance and participate in both cell transformation and proliferation, as well as in the progression and metastasis process. Despite the availability of different drugs to inhibit in vivo XOR activity, the complexity of XOR inhibition effects should be carefully considered before clinical application, save in the case of symptomatic hyperuricemia.


Assuntos
Síndrome Metabólica/complicações , Síndrome Metabólica/metabolismo , Neoplasias/etiologia , Neoplasias/metabolismo , Xantina Desidrogenase/metabolismo , Animais , Transformação Celular Neoplásica/metabolismo , Progressão da Doença , Ativação Enzimática , Humanos , Síndrome Metabólica/epidemiologia , Neoplasias/epidemiologia , Medição de Risco , Xantina Desidrogenase/genética
10.
Plant Physiol ; 178(3): 1027-1044, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30190419

RESUMO

The nitrogen (N)-rich ureides allantoin and allantoate, which are products of purine catabolism, play a role in N delivery in Leguminosae. Here, we examined their role as an N source in nonlegume plants using Arabidopsis (Arabidopsis thaliana) plants mutated in XANTHINE DEHYDROGENASE1 (AtXDH1), a catalytic bottleneck in purine catabolism. Older leaves of the Atxdh1 mutant exhibited early senescence, lower soluble protein, and lower organic N levels as compared with wild-type older leaves when grown with 1 mm nitrate but were comparable to the wild type under 5 mm nitrate. Similar nitrate-dependent senescence phenotypes were evident in the older leaves of allantoinase (Ataln) and allantoate amidohydrolase (Ataah) mutants, which also are impaired in purine catabolism. Under low-nitrate conditions, xanthine accumulated in older leaves of Atxdh1, whereas allantoin accumulated in both older and younger leaves of Ataln but not in wild-type leaves, indicating the remobilization of xanthine-degraded products from older to younger leaves. Supporting this notion, ureide transporter expression was enhanced in older leaves of the wild type in low-nitrate as compared with high-nitrate conditions. Elevated transcripts and proteins of AtXDH and AtAAH were detected in low-nitrate-grown wild-type plants, indicating regulation at protein and transcript levels. The higher nitrate reductase activity in Atxdh1 leaves compared with wild-type leaves indicated a need for nitrate assimilation products. Together, these results indicate that the absence of remobilized purine-degraded N from older leaves of Atxdh1 caused senescence symptoms, a result of higher chloroplastic protein degradation in older leaves of low-nitrate-grown plants.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/enzimologia , Nitratos/metabolismo , Nitrogênio/metabolismo , Purinas/metabolismo , Xantina Desidrogenase/metabolismo , Alantoína/metabolismo , Amidoidrolases/genética , Amidoidrolases/metabolismo , Arabidopsis/genética , Arabidopsis/fisiologia , Proteínas de Arabidopsis/genética , Proteína 5 Relacionada à Autofagia/genética , Proteína 5 Relacionada à Autofagia/metabolismo , Família da Proteína 8 Relacionada à Autofagia/genética , Família da Proteína 8 Relacionada à Autofagia/metabolismo , Mutação , Folhas de Planta/enzimologia , Folhas de Planta/genética , Folhas de Planta/fisiologia , Fatores de Tempo , Ureo-Hidrolases/genética , Ureo-Hidrolases/metabolismo , Xantina Desidrogenase/genética
11.
Redox Biol ; 19: 274-289, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30196191

RESUMO

Nitric oxide radical (NO) is a signaling molecule involved in several physiological and pathological processes and a new nitrate-nitrite-NO pathway has emerged as a physiological alternative to the "classic" pathway of NO formation from L-arginine. Since the late 1990s, it has become clear that nitrite can be reduced back to NO under hypoxic/anoxic conditions and exert a significant cytoprotective action in vivo under challenging conditions. To reduce nitrite to NO, mammalian cells can use different metalloproteins that are present in cells to perform other functions, including several heme proteins and molybdoenzymes, comprising what we denominated as the "non-dedicated nitrite reductases". Herein, we will review the current knowledge on two of those "non-dedicated nitrite reductases", the molybdoenzymes xanthine oxidoreductase and aldehyde oxidase, discussing the in vitro and in vivo studies to provide the current picture of the role of these enzymes on the NO metabolism in humans.


Assuntos
Aldeído Oxidase/metabolismo , Óxido Nítrico/biossíntese , Óxido Nítrico/metabolismo , Nitritos/metabolismo , Xantina Desidrogenase/metabolismo , Animais , Humanos , Nitratos/metabolismo , Nitrito Redutases/metabolismo , Oxirredução , Espécies Reativas de Nitrogênio/metabolismo
12.
Biosci Rep ; 38(5)2018 10 31.
Artigo em Inglês | MEDLINE | ID: mdl-30104401

RESUMO

Uric acid (UA) is the end product of the catabolism of purines, and its serum levels are commonly increased in cancer patients. We aimed to explore the transcriptional regulation of tumour uricogenesis in human tumours, and relate uricogenesis with tumour pathological and pharmacological findings. Using data from The Cancer Genome Atlas (TCGA), we analysed the expression levels of xanthine dehydrogenase (XDH) and adenine phosphoribosyltransferase (APRT), two key enzymes in UA production and the purine salvage pathway, respectively. We found large differences between tumour types and individual tumours in their expression of XDH and APRT Variations in locus-specific DNA methylation and gene copy number correlated with the expression levels of XDH and APRT in human tumours respectively. We explored the consequences of this differential regulation of uricogenesis. Tumours with high levels of XDH mRNA were characterised by higher expression of several genes encoding pro-inflammatory and immune cytokines, and increased levels of tumour infiltration with immune cells. Finally, we studied cancer drug sensitivity using data from the National Cancer Institute-60 (NCI-60) database. A specific correlation was found between the expression levels of APRT and cell sensitivity to the chemotherapeutic agent 5-fluorouracil (5-FU). Our findings underline the existence of great differences in uricogenesis between different types of human tumours. The study of uricogenesis offers promising perspectives for the identification of clinically relevant molecular biomarkers and for tumour stratification in the therapeutic context.


Assuntos
Adenina Fosforribosiltransferase/genética , Neoplasias/genética , Ácido Úrico/sangue , Xantina Desidrogenase/genética , Adenina Fosforribosiltransferase/metabolismo , Variações do Número de Cópias de DNA/genética , Metilação de DNA/genética , Bases de Dados Factuais , Resistencia a Medicamentos Antineoplásicos/genética , Feminino , Fluoruracila/farmacologia , Regulação Neoplásica da Expressão Gênica/genética , Humanos , Masculino , Neoplasias/sangue , Neoplasias/classificação , Xantina Desidrogenase/metabolismo
13.
J Trace Elem Med Biol ; 49: 72-78, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29895374

RESUMO

Compounds containing trace elements copper or zinc are potential gout and hyperuricemia suppressant by virtue of their inhibiting effect on xanthine oxidase/xanthine dehydrogenase (XOD/XDH) and anti-inflammatory and anti-oxidative function. In this study, compounds Cu(hmy-paa)·SO4·H2O (simplified as CuHP) and Zn(hmy-paa)·SO4·H2O (simplified as ZnHP) are synthesized, where hmy-paa stands for 3-(4-hydroxy-3-methoxyphenyl)-N-(1H-pyrazol-3-yl)acrylamide). The ligand hmy-paa is composed of functional ferulic acid and 3-aminopyrazole. The XOD and XDH activity of the mouse liver homogenate could efficiently be inhibited by CuHP and ZnHP. XOD has been recognized as one of the promising targets for the treatment of hyperuricemia. Fluorescence spectrometry study indicates that the interaction between the compound and XOD could be strengthened by the introduction of metals. In vitro drug efficacy study illustrates that metals copper and zinc distinctly improves the uric acid reducing efficacy by suppressing XOD activation. Hyperuricemia mouse model is induced by co-treatment of hypoxanthine and oteracil potassium. Intraperitoneal injection of CuHP and ZnHP to hyperuricemia mice exhibits a significant effect on reducing serum uric acid. The serum creatinine value detection indicates that the side effect of CuHP and ZnHP on renal function is weak. The computational docking simulation exhibits the tightly binding mode between the compound and XOD. Consequently, compounds CuHP and ZnHP are new type candidates for the treatment of gout and hyperuricemia.


Assuntos
Cobre/química , Inibidores Enzimáticos/química , Inibidores Enzimáticos/uso terapêutico , Hiperuricemia/tratamento farmacológico , Hiperuricemia/metabolismo , Oligoelementos/química , Xantina Oxidase/metabolismo , Zinco/química , Animais , Ácidos Cumáricos/metabolismo , Masculino , Camundongos , Ácido Úrico/metabolismo , Xantina Desidrogenase/metabolismo
14.
Obesity (Silver Spring) ; 26(7): 1168-1178, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29877616

RESUMO

OBJECTIVE: The production of uric acid in murine white adipose tissue (mWAT), and that such production was augmented in obese mice, was recently reported. However, little is known about the secretion of metabolites associated with purine catabolism in human WAT (hWAT). The present study analyzed this in hWAT. METHODS: Freshly isolated hWAT and mWAT were cultured. The secretion of metabolites associated with purine catabolism was measured. Tissue distribution profiles of genes associated with purine metabolism and metabolite profiling of adipocytes in hypoxia were analyzed. RESULTS: Secretion of hypoxanthine from hWAT was higher than those of xanthine and uric acid. On the other hand, secretion of uric acid was relatively higher than xanthine and hypoxanthine in mWAT. Xanthine oxidoreductase (XOR) mRNA expression levels in hWAT were markedly lower than that in the human liver. In murine tissues, XOR mRNA expression levels in mWAT were comparable with those in the liver. Cultured human adipocytes secreted hypoxanthine, and its secretion was increased under hypoxia. The metabolic analysis of human adipocytes showed that hypoxia increased metabolites associated with de novo biosynthesis of purine nucleotides. CONCLUSIONS: The present study revealed that hypoxanthine was secreted from human adipose tissue, and the secretion might be increased in local hypoxia.


Assuntos
Tecido Adiposo/metabolismo , Hipoxantina/metabolismo , Hipóxia/metabolismo , Células 3T3-L1 , Adipócitos/metabolismo , Tecido Adiposo Branco/metabolismo , Adolescente , Adulto , Animais , Células Cultivadas , Humanos , Hipóxia/genética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Ácido Úrico/metabolismo , Xantina/metabolismo , Xantina Desidrogenase/genética , Xantina Desidrogenase/metabolismo , Adulto Jovem
15.
FEBS Lett ; 592(12): 2126-2139, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29749013

RESUMO

Nitric oxide (NO) is an important gasotransmitter involved in numerous intra- and intercellular signaling events. In addition to the oxidative pathway of NO generation, which includes three NO synthase (NOS) isoforms in mammals, a reductive pathway contributes to NO generation. In this pathway, nitrite is reduced to NO by various metal-containing proteins. Among these, all members of the eukaryotic molybdenum (Mo)-dependent enzyme family were found to be able to reduce nitrite to NO. This Review focuses on the current state of research in the field of Mo-dependent nitrite reduction in eukaryotes. An overview on the five eukaryotic Mo-enzymes is given, and similarities as well as differences in their nitrite reduction mechanisms are presented and discussed in the context of physiological relevance.


Assuntos
Vias Biossintéticas , Molibdênio/química , Óxido Nítrico/biossíntese , Nitritos/química , Aldeído Oxidase/química , Aldeído Oxidase/metabolismo , Animais , Humanos , Nitrato Redutase/química , Nitrato Redutase/metabolismo , Oxirredutases/química , Oxirredutases/metabolismo , Conformação Proteica , Sulfito Oxidase/química , Sulfito Oxidase/metabolismo , Xantina Desidrogenase/metabolismo
16.
Artigo em Inglês | MEDLINE | ID: mdl-29723117

RESUMO

Hereditary xanthinuria (type I) is caused by an inherited deficiency of the xanthine oxidorectase (XDH/XO), and is characterized by very low concentration of uric acid in blood and urine and high concentration of urinary xanthine, leading to urolithiasis. Type II results from a combined deficiency of XDH/XO and aldehyde oxidase. Patients present with hematuria, renal colic, urolithiasis or even acute renal failure. Clinical symptoms are the same for both types. In a third type, clinically distinct, sulfite oxidase activity is missing as well as XDH/XO and aldehyde oxidase. The prevalence is not known, but about 150 cases have been described so far. Hypouricemia is sometimes overlooked, that´s why we have set up the diagnostic flowchart. This consists of a) evaluation of uric acid concentrations in serum and urine with exclusion of primary renal hypouricemia, b) estimation of urinary xanthine, c) allopurinol loading test, which enables to distinguish type I and II; and finally assay of xanthine oxidoreductase activity in plasma with molecular genetic analysis. Following this diagnostic procedure we were able to find first patients with hereditary xanthinuria in our Czech population. We have detected nine cases, which is one of the largest group worldwide. Four patients were asymptomatic. All had profound hypouricemia, which was the first sign and led to referral to our department. Urinary concentrations of xanthine were in the range of 170-598 mmol/mol creatinine (normal < 30 mmol/mol creatinine). Hereditary xanthinuria is still unrecognized disorder and subjects with unexplained hypouricemia need detailed purine metabolic investigation.


Assuntos
Aldeído Oxidase/deficiência , Erros Inatos do Metabolismo/epidemiologia , Erros Inatos do Metabolismo da Purina-Pirimidina/epidemiologia , Purinas/metabolismo , Xantina Desidrogenase/deficiência , Xantina Desidrogenase/metabolismo , Adulto , Aldeído Oxidase/sangue , Aldeído Oxidase/urina , Alopurinol/metabolismo , Criança , Pré-Escolar , República Tcheca/epidemiologia , Diagnóstico Diferencial , Humanos , Erros Inatos do Metabolismo/sangue , Erros Inatos do Metabolismo/diagnóstico , Erros Inatos do Metabolismo/urina , Erros Inatos do Metabolismo da Purina-Pirimidina/sangue , Erros Inatos do Metabolismo da Purina-Pirimidina/diagnóstico , Erros Inatos do Metabolismo da Purina-Pirimidina/urina , Erros Inatos do Transporte Tubular Renal/sangue , Erros Inatos do Transporte Tubular Renal/epidemiologia , Erros Inatos do Transporte Tubular Renal/urina , Ácido Úrico/sangue , Ácido Úrico/urina , Cálculos Urinários/sangue , Cálculos Urinários/epidemiologia , Cálculos Urinários/urina , Xantina/sangue , Xantina/urina , Xantina Desidrogenase/sangue , Xantina Desidrogenase/urina
17.
Biochim Biophys Acta Mol Basis Dis ; 1864(8): 2557-2565, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29733945

RESUMO

Xanthine oxidoreductase (XOR) could contribute to the pathogenesis of metabolic syndrome through the oxidative stress and the inflammatory response induced by XOR-derived reactive oxygen species and uric acid. Hyperuricemia is strongly linked to hypertension, insulin resistance, obesity and hypertriglyceridemia. The serum level of XOR is correlated to triglyceride/high density lipoprotein cholesterol ratio, fasting glycemia, fasting insulinemia and insulin resistance index. Increased activity of endothelium-linked XOR may promote hypertension. In addition, XOR is implicated in pre-adipocyte differentiation and adipogenesis. XOR and uric acid play a role in cell transformation and proliferation as well as in the progression and metastatic process. Collected evidences confirm the contribution of XOR and uric acid in metabolic syndrome. However, in some circumstances XOR and uric acid may have anti-oxidant protective outcomes. The dual-face role of both XOR and uric acid explains the contradictory results obtained with XOR inhibitors and suggests caution in their therapeutic use.


Assuntos
Endotélio Vascular/metabolismo , Síndrome Metabólica/metabolismo , Ácido Úrico/metabolismo , Xantina Desidrogenase/metabolismo , Adipócitos/metabolismo , Adipócitos/patologia , Adipogenia , Animais , Diferenciação Celular , Endotélio Vascular/patologia , Humanos , Hipertensão/metabolismo , Hipertensão/patologia , Hiperuricemia/metabolismo , Hiperuricemia/patologia , Síndrome Metabólica/patologia
18.
Mol Biol Rep ; 45(4): 419-432, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29767342

RESUMO

Reactive oxygen species (ROS) play key roles in many physiological processes. In particular, the sterilization mechanism of bacteria using ROS in macrophages is a very important function for biological defense. Xanthine dehydrogenase (XDH) and aldehyde oxidase (AOX), members of the molybdo-flavoenzyme subfamily, are known to generate ROS. Although these enzymes occur in many vertebrates, some insects, and plants, little research has been conducted on XDHs and AOXs in crustaceans. Here, we cloned the entire cDNA sequences of XDH (MjXDH: 4328 bp) and AOX (MjAOX: 4425 bp) from Marsupenaeus japonicus (kuruma shrimp) using reverse transcriptase-polymerase chain reaction (RT-PCR) and random amplification of cDNA ends (RACE). Quantitative real-time RT-PCR transcriptional analysis revealed that MjXDH mRNA is highly expressed in heart and stomach tissues, whereas MjAOX mRNA is highly expressed in the lymphoid organ and intestinal tissues. Furthermore, expression of MjAOX was determined to be up-regulated in the lymphoid organ in response to Vibrio penaeicida at 48 and 72 h after injection; in contrast, hydrogen peroxide (H2O2) concentrations increased significantly at 6, 12, 48, and 72 h after injection with white spot syndrome virus (WSSV) and at 72 h after injection with V. penaeicida. To the best of our knowledge, this study is the first to have identified and cloned XDH and AOX from a crustacean species.


Assuntos
Aldeído Oxidase/genética , Penaeidae/metabolismo , Xantina Desidrogenase/genética , Aldeído Oxidase/metabolismo , Aldeído Oxidase/fisiologia , Sequência de Aminoácidos/genética , Animais , Sequência de Bases/genética , Clonagem Molecular , DNA Complementar , Perfilação da Expressão Gênica/métodos , Peróxido de Hidrogênio/análise , Imunidade Inata/genética , Penaeidae/genética , Penaeidae/microbiologia , Espécies Reativas de Oxigênio/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Alinhamento de Sequência , Frutos do Mar , Vibrio/patogenicidade , Vírus da Síndrome da Mancha Branca 1/patogenicidade , Xantina Desidrogenase/metabolismo , Xantina Desidrogenase/fisiologia
19.
Circ J ; 82(7): 1892-1899, 2018 06 25.
Artigo em Inglês | MEDLINE | ID: mdl-29643318

RESUMO

BACKGROUND: Xanthine oxidoreductase (XOR) is an enzyme that catalyzes the formation of uric acid from hypoxanthine and xanthine, leading to an increase in superoxide and reactive oxygen species. Activation of XOR promotes oxidative stress-related tissue injury. We investigated the associations between metabolic parameters and plasma XOR activity measured by a sensitive and accurate assay using a combination of liquid chromatography and triple quadrupole mass spectrometry to detect [13C2,15N2]-uric acid using [13C2,15N2]-xanthine as a substrate.Methods and Results:A total of 627 Japanese subjects (M/F, 292/335) from the Tanno-Sobetsu Study, a population-based cohort, were recruited. Plasma XOR activity was significantly higher in males than in females, and habitual smoking was associated with elevation of activity. Plasma XOR activity was positively correlated with body mass index (BMI; r=0.323, P<0.001), waist circumference, blood pressure, and levels of liver enzymes including alanine transaminase (r=0.694, P<0.001), uric acid (r=0.249, P<0.001), triglycerides (r=0.312, P<0.001), hemoglobin A1c, fasting glucose, insulin and HOMA-R (r=0.238, P<0.001) as a marker of insulin resistance and was negatively correlated with high-density lipoprotein cholesterol level. On stepwise and multivariate regression analyses, BMI, smoking and levels of alanine transaminase, uric acid, triglycerides and HOMA-R were independent predictors of plasma XOR activity after adjustment for age and gender. CONCLUSIONS: Plasma XOR activity is a novel biomarker of metabolic disorders in a general population.


Assuntos
Doenças Metabólicas/diagnóstico , Xantina Desidrogenase/sangue , Idoso , Idoso de 80 Anos ou mais , Grupo com Ancestrais do Continente Asiático , Biomarcadores/sangue , HDL-Colesterol/sangue , Cromatografia Líquida , Estudos de Coortes , Feminino , Humanos , Resistência à Insulina , Masculino , Espectrometria de Massas , Doenças Metabólicas/enzimologia , Doenças Metabólicas/epidemiologia , Pessoa de Meia-Idade , Xantina Desidrogenase/metabolismo
20.
Drug Metab Pharmacokinet ; 33(1): 77-81, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29342419

RESUMO

Hyperuricemia induces gout and kidney stones and accelerates the progression of renal and cardiovascular diseases. Adenosine 5'-triphosphate-binding cassette subfamily G member 2 (ABCG2) is a urate transporter, and common dysfunctional variants of ABCG2, non-functional Q126X (rs72552713) and semi-functional Q141K (rs2231142), are risk factors for hyperuricemia and gout. A recent genome wide association study suggested that allopurinol, a serum uric acid-lowering drug that inhibits xanthine dehydrogenase, is a potent substrate of ABCG2. In this study, we aimed to examine the transport of xanthine dehydrogenase inhibitors via ABCG2. Our results show that ABCG2 transports oxypurinol, an active metabolite of allopurinol, whereas allopurinol and febuxostat, a new xanthine dehydrogenase inhibitor, are not substrates of ABCG2. The amount of oxypurinol transported by ABCG2 vesicles significantly increased in the presence of ATP, compared to that observed with mock vesicles. Since the half-life of oxypurinol is longer than that of allopurinol, the xanthine dehydrogenase-inhibiting effect of allopurinol mainly depends on its metabolite, oxypurinol. Our results indicate that the serum level of oxypurinol would increase in patients with ABCG2 dysfunction.


Assuntos
Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/metabolismo , Alopurinol/metabolismo , Proteínas de Neoplasias/metabolismo , Oxipurinol/metabolismo , Xantina Desidrogenase/antagonistas & inibidores , Xantina Desidrogenase/metabolismo , Transporte Biológico/fisiologia , Membrana Celular/metabolismo , Inibidores Enzimáticos/metabolismo , Células HEK293 , Células Hep G2 , Humanos , Hiperuricemia/metabolismo
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