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1.
Exerc Immunol Rev ; 26: 24-42, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32139353

RESUMO

INTRODUCTION: The essential amino acid tryptophan (TRP) is primarily degraded through the kynurenine (KYN) pathway, which is dysregulated in several chronic diseases. KYN pathway metabolites have immune- and neuro-modulatory properties and are involved in th de novo synthesis of nicotinamide adenine dinucleotide (NAD+). Currently, little evidence exists demonstrating that physical exercise may influence this pathway. However, differences between acute and chronic stimuli as well as the influence of exercise modalities remain to be investigated. Here, we provide an overview of existing studies and present results of a randomized cross-over trial on acute effects of a single-bout of resistance and endurance exercise. METHODS: 24 healthy male adults conducted both an acute endurance exercise (EE) and resistance exercise (RE) session. Blood samples were collected before, immediately after and one hour after cessation of each exercise session. Outcomes comprised serum levels of TRP, KYN, kynurenic acid (KA), quinolinic acid (QA) and calculated ratios. Gene expression of the enzymes indoleamine 2,3 dioxygenase (IDO) 1 and kynurenine aminotransferase (KAT) 4 was measured in peripheral blood mononuclear cells (PBMCs). Moreover, serum concentrations of the potential KYN pathway mediators interleukin (IL)-6 and cortisol were determined. Finally, we investigated baseline correlations between immune cell subsets, potential mediators and initial KYN pathway activation outcomes. RESULTS: The KYN/TRP ratio correlated positively with IL-6 and CD56bright NK-cells and negatively with CD56dim NKcells. Expression of IDO1 in PBMCs correlated positively with IL-6, regulatory T-cells and CD56bright NK-cells, whereas negative correlations to cytotoxic T-cells and CD56dim NKcells were revealed. A significant time effect on KYN/TRP ratio was detected for RE. Regarding KA and KA/KYN ratio, an increase after exercise followed by a decrease at the follow- up measurement was revealed in EE. KAT4 expression also increased after exercise in EE. Moreover, elevated QA levels were observed after the EE session. CONCLUSIONS: In contrast to chronic exercise interventions, single-bouts of endurance exercise provoke acute alterations on KYN pathway outcomes in humans. Our results indicate that EE induces stronger alterations than RE. Enhanced conversion of KYN to both, KA and QA suggest a peripheral KYN clearance, thereby preventing pathological accumulation within the CNS. Future acute and chronic exercise studies are needed to examine the role of NAD+ synthesis starting with TRP and the interplay between KYN pathway activation and mid- to long-term immunological modulations.


Assuntos
Treino Aeróbico , Cinurenina/sangue , Leucócitos Mononucleares/imunologia , Treinamento de Resistência , Adulto , Estudos Cross-Over , Exercício , Humanos , Hidrocortisona/imunologia , Indolamina-Pirrol 2,3,-Dioxigenase/imunologia , Interleucina-6/imunologia , Ácido Cinurênico/sangue , Leucócitos Mononucleares/enzimologia , Masculino , Ácido Quinolínico/sangue , Transaminases/imunologia , Triptofano/sangue
2.
Talanta ; 206: 120245, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31514823

RESUMO

A novel L-tryptophan (L-Trp) electrochemical sensor is fabricated, which is based on the molecularly imprinted copolymer (MIP) of dual -functional monomers and ionic liquid (i.e. 1-butyl-3-methylimidazolium hexafluorophosphate) functionalized multi-walled carbon nanotubes (MWCNTs@IL). The MWCNTs@IL is prepared via ion exchange, while the MIP is synthesized by using L-Trp as template, styrene and 4-vinylbenzoic acid as functional monomers, Triton X-100 as emulsifier, 1, 2-divinylbenzene as cross-linking reagent and K2S2O8 as initiator. Prior to copolymerization the functional monomer 4-vinylbenzoic acid is combined with the template molecule by forming amide bond. The template molecule is eluted by hydrolysis, and rebound by electrostatic, hydrogen-bond and π-π interaction. To construct L-Trp sensor a little of Nafion is introduced to enhance the stability and to promote rebinding. The resulting sensor Nafion-MIP-MWCNTs@IL/GCE shows a wide linear range (8 nM-26 µM) and a low detection limit (6 nM). It is successfully applied to the determination of L-Trp in oral liquid and human serum samples.


Assuntos
Técnicas Eletroquímicas/métodos , Polímeros/química , Triptofano/sangue , Técnicas Eletroquímicas/instrumentação , Eletrodos , Polímeros de Fluorcarboneto/química , História Medieval , Humanos , Imidazóis/química , Limite de Detecção , Impressão Molecular/métodos , Nanotubos de Carbono/química , Polimerização , Polímeros/síntese química , Reprodutibilidade dos Testes , Estereoisomerismo , Estireno/química , Estirenos/química , Triptofano/química
3.
J Sports Sci Med ; 18(4): 669-673, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31827351

RESUMO

Regular physical activity and exercise interventions are suspected to have anti-inflammatory effects depending on exercise modality, thereby potentially reducing the risk and progress of several chronic diseases. Alterations in the kynurenine pathway may represent a link between inflammatory responses following acute exercise and chronic anti-inflammatory properties, such as increased levels of regulatory T-cells (Treg). Here, we hypothesize that acute exercise activates the kynurenine pathway and physical fitness is associated with proportions of circulating anti-inflammatory Treg in older healthy women. Nineteen older healthy female participants (55 years (SD: ± 5.6)) completed a cardiopulmonary incremental exercise test (CPET) with spirometry on a bicycle ergometer until exhaustion with maximum oxygen uptake (VO2max) as outcome. Blood samples were taken before (T0) and one minute after (T1) the CPET. Levels of tryptophan, serotonin and kynurenine were determined by enzyme-linked immunosorbent assays. Flow cytometry was used to identify proportions of T-cell subsets. Both, kynurenine (p = 0.003, d = 0.40) and the kynurenine/tryptophan ratio (p = 0.034, d = 0.48) increased significantly after acute exercise. Moreover, participants` VO2max was strongly correlated with Treg levels (p < 0.001, r = 0.689). This is the first study indicating a kynurenine pathway activation following acute exercise in older healthy women. The observed correlation between Treg levels and VO2max emphasizes a potential link between short-term upregulated kynurenine levels and longer-term anti-inflammatory properties of exercise. Future research is needed to clarify to what extend acute exercise-induced activations of the kynurenine pathway contribute to Treg differentiation.


Assuntos
Exercício/fisiologia , Cinurenina/sangue , Linfócitos T Reguladores/metabolismo , Idoso , Biomarcadores/sangue , Índice de Massa Corporal , Diferenciação Celular , Feminino , Humanos , Consumo de Oxigênio/fisiologia , Resistência Física/fisiologia , Aptidão Física/fisiologia , Projetos Piloto , Serotonina/sangue , Linfócitos T Reguladores/imunologia , Triptofano/sangue
4.
Artigo em Inglês | MEDLINE | ID: mdl-31586884

RESUMO

A sensitive, rapid and reliable ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed and validated to assay tryptophan (TRP) and its nine metabolites, including kynurenine (KYN), kynurenic acid (KYNA), 3-hydroxykynurenine (3-HK), 3-hydroxyanthranilic acid (3-HAA), xanthurenic acid (XA), 5-hydroxytryptamine (5-HT), 5-hydroxyindoleacetic acid (5-HIAA), 3-indolepropionic acid (IPA) and 3-indoleacetic acid (IAA) in human plasma. Tryptophan-d5 (TRP-d5) and carbamazepine (CAR) were applied to the method quantification, where TRP-d5 was the corresponding internal standard (IS) for TRP and KYN, and CAR was the corresponding IS for the other analytes. Plasma samples were processed by deproteinisation with acetonitrile, followed by separation on an Acquity UPLC HSS T3 column by using gradient elution with 0.1% (v/v) formic acid in water and acetonitrile and detection by electrospray ionisation tandem mass spectrometry in positive ion multiple reaction monitoring (MRM) within a total run time of 5 min. The calibration ranges were 3-600 ng/mL for 3-HK, 1.5-300 ng/mL for 5-HT, 25-5000 ng/mL for KYN, 1-200 ng/mL for XA, 100-20,000 ng/mL for TRP, 5-1000 ng/mL for KYNA, 2-400 ng/mL for 3-HAA, 2.5-500 ng/mL for 5-HIAA and 10-2000 ng/mL for IAA and IPA. All intra- and inter-day analytical variations were acceptable. Matrix effect and recovery evaluation proved that matrix effect can be negligible, and sample preparation approach was effective. The newly developed method can simultaneously determine a panel of TRP metabolites and was successfully applied in the clinical study characterising TRP metabolism in healthy volunteers.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Espectrometria de Massas em Tandem/métodos , Triptofano/sangue , Triptofano/metabolismo , Ácido 3-Hidroxiantranílico/análise , Ácido 3-Hidroxiantranílico/química , Ácido 3-Hidroxiantranílico/metabolismo , Adulto , Feminino , Humanos , Ácido Cinurênico/sangue , Ácido Cinurênico/química , Ácido Cinurênico/metabolismo , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Triptofano/química
5.
Nat Commun ; 10(1): 4346, 2019 09 25.
Artigo em Inglês | MEDLINE | ID: mdl-31554815

RESUMO

Despite remarkable success of immune checkpoint inhibitors, the majority of cancer patients have yet to receive durable benefits. Here, in order to investigate the metabolic alterations in response to immune checkpoint blockade, we comprehensively profile serum metabolites in advanced melanoma and renal cell carcinoma patients treated with nivolumab, an antibody against programmed cell death protein 1 (PD1). We identify serum kynurenine/tryptophan ratio increases as an adaptive resistance mechanism associated with worse overall survival. This advocates for patient stratification and metabolic monitoring in immunotherapy clinical trials including those combining PD1 blockade with indoleamine 2,3-dioxygenase/tryptophan 2,3-dioxygenase   (IDO/TDO) inhibitors.


Assuntos
Carcinoma de Células Renais/tratamento farmacológico , Everolimo/uso terapêutico , Neoplasias Renais/tratamento farmacológico , Melanoma/tratamento farmacológico , Metabolômica , Nivolumabe/uso terapêutico , Adaptação Fisiológica/efeitos dos fármacos , Idoso , Antineoplásicos/uso terapêutico , Carcinoma de Células Renais/sangue , Carcinoma de Células Renais/metabolismo , Ensaios Clínicos como Assunto , Feminino , Humanos , Estimativa de Kaplan-Meier , Neoplasias Renais/sangue , Neoplasias Renais/metabolismo , Cinurenina/sangue , Masculino , Melanoma/sangue , Melanoma/metabolismo , Pessoa de Meia-Idade , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Receptor de Morte Celular Programada 1/metabolismo , Resultado do Tratamento , Triptofano/sangue
6.
Biomolecules ; 9(6)2019 06 22.
Artigo em Inglês | MEDLINE | ID: mdl-31234553

RESUMO

In this study, we reported facile synthesis of Fe3O4/C composite and its application for the cost-effective and sensitive determination of tryptophan (Trp) in human serum samples. Fe3O4/C composites were prepared by a simple one-pot hydrothermal method followed by a mild calcination procedure, using FeCl3∙6H2O as Fe3O4 precursor, and glucose as reducing agent and carbon source simultaneously. The Fe3O4/C composite modified glassy carbon electrode (Fe3O4/C/GCE) was prepared by drop-casting method. The microstructure and morphology of Fe3O4/C composite was characterized by powder X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. Due to large specific surface area and synergistic effect from Fe3O4 nanoparticles and carbon coating, Fe3O4/C composite showed excellent electrocatalytic activity toward the oxidation of Trp. As a result, the proposed Fe3O4/C/GCE displayed superior analytical performances toward Trp determination, with two wide detection ranges (1.0-80 µM and 80-800 µM) and a low detection limit (0.26 µM, S/N = 3). Moreover, successful detection of Trp in human serum samples further validate the practicability of the proposed sensor.


Assuntos
Carbono/química , Análise Custo-Benefício , Eletroquímica/instrumentação , Limite de Detecção , Nanopartículas de Magnetita/química , Nanocompostos/química , Triptofano/análise , Eletroquímica/economia , Eletrodos , Humanos , Temperatura Ambiente , Fatores de Tempo , Triptofano/sangue , Triptofano/química
7.
Brain Stimul ; 12(5): 1135-1142, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31176607

RESUMO

BACKGROUND: Prior studies suggest that activation of the tryptophan catabolism via the kynurenine pathway by proinflammatory cytokines may be involved in the pathophysiology of depression. Electroconvulsive therapy (ECT) is an effective treatment for major depression (MD) with immunomodulation as one of the proposed modes of action. OBJECTIVE: The aim of this study was to investigate serum concentrations of tryptophan and kynurenine pathway metabolites in MD patients and healthy controls, and to explore the effect of ECT on components of the kynurenine pathway. METHODS: The study included 27 moderately to severely depressed patients referred to ECT. Blood samples were collected prior to treatment and after the completed ECT-series. Baseline samples were also collected from 14 healthy, age- and sex-matched controls. Serum concentrations of tryptophan, kynurenine, 3-hydroxykynurenine (HK), kynurenic acid (KA), xanthurenic acid (XA), anthranilic acid (AA), 3-hydroxyanthranilic acid (HAA), quinolinic acid (QA), picolinic acid (Pic), pyridoxal 5'-phosphat (PLP), riboflavin, neopterin and cotinine were measured. RESULTS: Patients with MD had lower levels of neuroprotective kynurenine-pathway metabolites (KA, XA and Pic) and lower metabolite ratios (KA/Kyn and KA/QA) reflecting reduced neuroprotection compared to controls. The concentration of the inflammatory marker neopterin was increased after ECT, along with Pic and the redox active and immunosuppressive metabolite HAA. CONCLUSION: In this pilot study, we found increased concentrations of inflammatory marker neopterin and putative neuroprotective kynurenine metabolites HAA and Pic in MD patients after ECT. Further research in larger cohorts is required to conclude whether ECT exerts its therapeutic effects via changes in the kynurenine pathway.


Assuntos
Transtorno Depressivo Maior/sangue , Transtorno Depressivo Maior/terapia , Eletroconvulsoterapia/métodos , Cinurenina/sangue , Triptofano/sangue , Adulto , Biomarcadores/sangue , Transtorno Depressivo Maior/diagnóstico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Estudos Prospectivos , Resultado do Tratamento , Adulto Jovem
8.
PLoS One ; 14(6): e0218218, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31181125

RESUMO

INTRODUCTION: Dogs with protein-losing enteropathy (PLE) have decreased serum tryptophan concentrations, which may contribute to disease pathogenesis. Indoleamine-pyrrole 2,3-dioxygenase-1 (IDO-1) expression is associated with low serum tryptophan concentrations and is increased in the gastrointestinal tract of humans with inflammatory bowel disease (IBD). Therefore, the objective of our study was to determine if the mRNA expression of IDO-1 is increased in the duodenal mucosa of dogs with PLE as compared to dogs with chronic enteropathy (CE) and healthy dogs, and whether this expression is correlated with changes in serum tryptophan concentration. METHODS: Our study was a retrospective study using archived paraffin-embedded duodenal biopsy specimens from 8 healthy Beagle dogs from the Iowa State University Canine Service Colony and 18 and 6 client-owned dogs diagnosed with CE and PLE, respectively at the Bristol Veterinary School. A novel RNA in situ hybridization (ISH) technology, RNAscope, was used to identify IDO-1 mRNA mucosal expression in duodenal tissues. An IDO-1 specific probe was hybridized onto 10 duodenal biopsy sections from each dog whereby RNAscope signal (mRNA expression) was quantified by a single operator using light microscopy. RESULTS: Dogs with PLE had significantly higher mRNA expression of IDO-1 in the duodenal mucosa compared to healthy dogs (mucosal percentage IDO-1 positive: P = 0.0093, (mean ± S.D) control: 19.36 ± 7.08, PLE: 34.12 ± 5.98, average fold difference: 1.76 and mucosal IDO-1 H-score: P = 0.0356, (mean ± S.D) control: 45.26 ± 19.33, PLE: 84.37 ± 19.86, average fold difference: 1.86). The duodenal mucosal mRNA expression of IDO-1 was negatively correlated with serum tryptophan concentrations in dogs with PLE (mucosal IDO-1 H-score: Spearman's rank correlation coefficient = -0.94, P = 0.0048). CONCLUSIONS: In conclusion, our study suggests that decreased serum tryptophan concentrations in dogs with PLE is associated with increased intestinal IDO-1 expression. Further studies are needed to determine potential inflammatory pathways responsible for increased expression of IDO-1 in the intestinal tract of dogs with PLE.


Assuntos
Indolamina-Pirrol 2,3,-Dioxigenase/genética , Mucosa Intestinal/metabolismo , Enteropatias Perdedoras de Proteínas/metabolismo , RNA Mensageiro/metabolismo , Triptofano/sangue , Animais , Cães , Duodeno , Enteropatias Perdedoras de Proteínas/veterinária , Estudos Retrospectivos
9.
Biosci Biotechnol Biochem ; 83(9): 1756-1765, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31119994

RESUMO

Depressive disorders are partly caused by chronic inflammation through the kynurenine (KYN) pathway. Preventive intervention using anti-inflammatory reagents may be beneficial for alleviating the risk of depression. In this study, we focused on the Japanese local citrus plant, Citrus tumida hort. ex Tanaka (C. tumida; CT), which contains flavonoids such as hesperidin that have anti-inflammatory actions. The dietary intake of 5% immature peels of CT fruits slightly increased stress resilience in a subchronic and mild social defeat (sCSDS) model in mice. Moreover, the dietary intake of 0.1% hesperidin significantly increased stress resilience and suppressed KYN levels in the hippocampus and prefrontal cortex in these mice. In addition, KYN levels in the hippocampus and prefrontal cortex were significantly correlated with the susceptibility to stress. In conclusion, these results suggest that dietary hesperidin increases stress resilience by suppressing the augmentation of KYN signaling under sCSDS.


Assuntos
Citrus/química , Dieta , Hesperidina/administração & dosagem , Hipocampo/efeitos dos fármacos , Cinurenina/metabolismo , Córtex Pré-Frontal/efeitos dos fármacos , Resiliência Psicológica/efeitos dos fármacos , Comportamento Social , Estresse Psicológico/prevenção & controle , Animais , Comportamento Animal , Corticosterona/sangue , Hesperidina/farmacologia , Hipocampo/metabolismo , Interleucina-1beta/sangue , Interleucina-6/sangue , Cinurenina/sangue , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos ICR , Córtex Pré-Frontal/metabolismo , Triptofano/sangue
10.
Oxid Med Cell Longev ; 2019: 8461048, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31089419

RESUMO

Graft vasculopathy is the main feature of chronic rejection in organ transplantation, with oxidative stress being a major trigger. Inflammation-associated prooxidant processes may be controlled by antioxidants; however, interference with redox-regulated mechanisms is a complex endeavor. An essential feature of the cellular immune response is the acceleration of tryptophan (Trp) breakdown, leading to the formation of several bioactive catabolites. Long-term activation of this immunobiochemical pathway contributes to the establishment of a tolerogenic environment, thereby supporting allograft survival. Herein, the impact of the antioxidant sodium sulfite on the development of graft vasculopathy was assessed in murine aortic transplantation. Allogeneic (BALB/c to C57BL/6) heterotopic murine aortic transplantations were performed. Animals were left untreated or were treated with 10 µl of 0.1 M, of 0.01 M sodium sulfite, or of 0.1 M sodium sulfate, intraperitoneally once/day, until postoperative day (POD) 100. Grafts were assessed by histology, immunohistochemistry, and adhesion molecule gene expression. Serum concentrations of tryptophan and its catabolite kynurenine (Kyn) were measured. On day 100, graft vasculopathy was significantly increased upon treatment with 0.1 M sodium sulfite, compared to allogeneic untreated controls (p = 0.004), which correlated with a significant increase of α-smooth-muscle-actin, Vcam-1, and P-selectin. Serum Kyn concentrations increased in the allogeneic control group over time (p < 0.05, POD ≥ 50), while low-dose sodium sulfite treatment (0.01 M) treatment resulted in a decrease in Kyn levels over time (p < 0.05, POD ≥ 10), compared to the respective baselines (p < 0.05). Longitudinal analysis of serum metabolite concentrations in the different treatment groups further identified an overall effect of sodium sulfite on Kyn concentrations. Antioxidative treatment may result in ambivalent consequences. Our data reveal that an excess of antioxidants like sodium sulfite can aggravate allograft vasculopathy, which further highlights the challenges associated with interventions that interfere with the complex interplay of redox-regulated inflammatory processes.


Assuntos
Aloenxertos/efeitos dos fármacos , Aorta/transplante , Sulfitos/farmacologia , Triptofano/metabolismo , Doenças Vasculares/etiologia , Doenças Vasculares/patologia , Animais , Biomarcadores/sangue , Espessura Intima-Media Carotídea , Cinurenina/sangue , Complexo Principal de Histocompatibilidade , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Selectina-P/genética , Selectina-P/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Triptofano/sangue , Molécula 1 de Adesão de Célula Vascular/genética , Molécula 1 de Adesão de Célula Vascular/metabolismo
11.
Seizure ; 69: 265-272, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31129366

RESUMO

PURPOSE: There is growing evidence to support the role of the kynurenine pathway in the anticonvulsant efficacy of ketogenic diets (KDs) in refractory epilepsy. The aim of the present study was to measure blood levels of tryptophan (TRP) and its kynurenine derivatives and correlate them with seizure reduction after starting the KD in children with refractory epilepsy. METHODS: Sixteen children (9 F/7 M; 7.1 ± 5.1 years) with refractory epilepsy were treated with the KDs. Clinical efficacy and metabolic ketosis were monitored throughout the study; blood levels of TRP, kynurenine (KYN), kynurenic acid (KYNA), and 3-OH-kynurenine (3-OH-KYN) were measured at 3, 6, and 12 months on the diet and compared to the pre-KD levels. RESULTS: Out of 16 children, 14 attained a ≥50% reduction (responders) in seizure frequency 3 months after starting the KD. In the 14 responders, TRP levels decreased numerically (18-25%) but not significantly (P = 0.077) compared to the pre-KD control values. KYN levels decreased significantly (30-57%; P = 0.001) compared to the pre-KD control levels while KYNA levels significantly increased (38-96%; P < 0.001). KYNA/KYN ratios significantly increased (100-323%; P = 0.003) while 3-OH-KYN levels (P = 0.680) and KYN/TRP ratios (P = 0.385) remained unchanged. Higher concentrations of KYNA and lower concentrations of KYN (P < 0.05) were found in patients who attained a higher reduction in seizure frequencies on the KD. CONCLUSIONS: We report a pattern of changes in the blood level of kynurenines in patients with refractory epilepsy who started the KD. The results of this study further support the role of specific kynurenines (e.g. KYNA) in the efficacy of the KD in refractory epilepsy.


Assuntos
Dieta Cetogênica , Epilepsia Resistente a Medicamentos/sangue , Epilepsia Resistente a Medicamentos/dietoterapia , Cinurenina/sangue , Triptofano/sangue , Adolescente , Biomarcadores/sangue , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Ácido Cinurênico/sangue , Masculino , Estudos Prospectivos , Resultado do Tratamento
12.
Biomolecules ; 9(5)2019 05 08.
Artigo em Inglês | MEDLINE | ID: mdl-31072043

RESUMO

In this paper, a nanocomposite of cuprous oxide and electrochemically reduced graphene oxide (Cu2O‒ERGO) was prepared by a simple and low-cost method; hereby, a new method for the electrochemical determination of tryptophan (Trp) by this composite modified glassy carbon electrode (GCE) is proposed. The prepared materials and modified electrodes were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and cyclic voltammetry (CV). The results showed that Cu2O‒ERGO/GCE had good electrocatalytic activity for Trp. The effects of supporting electrolyte, scanning rate, accumulation potential, and accumulation time on the determination of Trp were studied. Under the optimum experimental conditions, Trp was quantitatively analyzed by square-wave voltammetry (SWV). The oxidation peak current of Trp had a good linear relationship with its concentration in the range of 0.02‒20 µM, and the detection limit was 0.01 µM (S/N = 3). In addition, the modified electrode has high sensitivity, good repeatability, and long-term stability. Finally, the proposed method has been successfully applied in the determination of Trp concentration in practical samples.


Assuntos
Cobre/química , Eletroquímica/métodos , Grafite/química , Nanocompostos/química , Nanopartículas/química , Triptofano/análise , Calibragem , Eletrodos , Humanos , Limite de Detecção , Nanopartículas/ultraestrutura , Oxirredução , Reprodutibilidade dos Testes , Ácidos Sulfúricos/química , Triptofano/sangue , Difração de Raios X
13.
BMC Infect Dis ; 19(1): 223, 2019 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-30832615

RESUMO

BACKGROUND: Indoleamine 2, 3-dioxygenase (IDO) is a key enzyme in the degradation of tryptophan (Trp) to kynurenine (Kyn). We measured IDO activity as the Kyn to Trp ratio, and investigated whether IDO could be used to assess prognosis of acquired immune deficiency Sydrome (AIDS) patients with pneumocystis pneumonia (PCP). METHODS: The Kyn and Trp concentration were measured by UPLC-MS/MS in plasma samples. A total of 49 AIDS-PCP patients were included in the analysis. Clinical characteristics and Kyn/Trp ratio were compared between survivors and non-survivors. RESULTS: Kyn/Trp ratio was significantly lower after anti-PCP treatment in AIDS patients with PCP (P < 0.0001). Plasma Kyn/Trp ratio was higher in patients with PaO2/FiO2 ≤ 300 mmHg than in those with PaO2/FiO2 > 300 mmHg (P = 0.007). Kyn/Trp ratio, D-dimer and CRP showed much higher AUC for predicting death of AIDS-PCP patients. Kyn/Trp ratio was useful for predicting the mortality of AIDS-PCP due to a significantly higher Kyn/Trp ratio in the non-survivors (P = 0.002). And the high Kyn/Trp ratio group had higher mortality rate than low Kyn/Trp group (32.1% vs. 9.1%, respectively, p = 0.024). CONCLUSION: Activation of the kynurenine pathway is associated with the severity and fatal outcomes of AIDS patients with pneumocystis pneumonia.


Assuntos
Infecções por HIV/patologia , Pneumonia/diagnóstico , Adulto , Antifúngicos/uso terapêutico , Área Sob a Curva , Biomarcadores/metabolismo , Cromatografia Líquida de Alta Pressão , Estudos de Coortes , Feminino , Infecções por HIV/complicações , Infecções por HIV/mortalidade , Humanos , Indolamina-Pirrol 2,3,-Dioxigenase/metabolismo , Cinurenina/análise , Cinurenina/sangue , Masculino , Pessoa de Meia-Idade , Pneumocystis/isolamento & purificação , Pneumonia/complicações , Pneumonia/tratamento farmacológico , Pneumonia/microbiologia , Prognóstico , Curva ROC , Taxa de Sobrevida , Espectrometria de Massas em Tandem , Triptofano/análise , Triptofano/sangue
14.
Artigo em Inglês | MEDLINE | ID: mdl-30862026

RESUMO

Metabolic syndrome (MetS) is a cluster of conditions, increasing the risk of developing diseases that can lead to premature death. Interferon γ-inducible (the production of which is dependent on the IFNγ rs2430561 polymorphism) tryptophan-kynurenine inflammatory cascade helps to understand the increased association between inflammatory process and MetS, which is why we seek the relationship between the IFNγ gene polymorphisms and serum levels of markers of interferon-gamma (IFNγ)-inducible inflammatory cascade. The study sample consisted of 416 women, including 118 (28.4%) with MetS. The research procedure involved interview, anthropometric measurements, and blood collection. Kynurenine levels were significantly higher in the group of women with MetS. In the group with MetS, the A/T genotype of the IFNγ gene was accompanied by higher kynurenine levels. A direct relationship between the IFNγ gene polymorphisms and the rest of the markers of IFNγ-inducible inflammatory cascade was not confirmed with regard to MetS in 45 to 60-year-old women. A disparity in the kynurenine level, as well as the relationship between the presence of the A/T genotype of the IFNγ gene and a higher level of kynurenine in the group of women with MetS, may indicate an association between inflammation, metabolic disorders and tryptophan-kynurenine inflammatory cascade.


Assuntos
Inflamação/genética , Interferon gama/genética , Síndrome Metabólica/genética , Polimorfismo Genético , Biomarcadores/sangue , Feminino , Genótipo , Humanos , Indolamina-Pirrol 2,3,-Dioxigenase/sangue , Inflamação/metabolismo , Interferon gama/sangue , Cinurenina/sangue , Cinurenina/metabolismo , Síndrome Metabólica/metabolismo , Pessoa de Meia-Idade , Serotonina/sangue , Triptofano/sangue , Triptofano/metabolismo
15.
Amino Acids ; 51(5): 783-793, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30868261

RESUMO

Chronic immune activation and ensuing inflammation that accompany HIV infection lead to adverse metabolic consequences and an increased risk of type 2 diabetes (T2D). We examined the additive effects of T2D on circulating biomarkers involved in inflammation, coagulation, and vascular function along with plasma amino acids in people living with HIV (PLWH). This cross-sectional study included PLWH with and without T2D (n = 32 total). Analyses involved a multiplex platform for circulating biomarkers and gas chromatography-vacuum ultraviolet spectroscopy for plasma amino acids. In PLWH and T2D, both fibrinogen (2.0 ± 0.6 vs 1.6 ± 0.4 µg/mL, p = 0.02) and von Willebrand factor (vWF) (40.8 ± 17.2 vs 26.7 ± 13.8 µg/mL, p = 0.02) were increased and tryptophan (47 ± 6 vs 53 ± 8 nmol/mL, p = 0.03) and threonine (102 ± 25 vs 125 ± 33 nmol/mL, p = 0.03) were decreased. Fibrinogen, as a biomarker of inflammation, and vWF, as a biomarker of endothelial dysfunction, are augmented by the combined effects of HIV and T2D and may contribute to the pathogenesis of T2D in PLWH. Chronic immune activation and inflammation compromise the integrity of the intestinal mucosa, which increases mucus production. Tryptophan metabolism is altered by a loss of intestinal membrane integrity and threonine is consumed in the production of mucus. Metabolic competition arising from increased protein synthesis in the setting of chronic inflammation along with the associated loss in intestinal membrane integrity may be a primary mechanism in the pathogenesis of T2D in PLWH and requires further investigation.


Assuntos
Biomarcadores/sangue , Diabetes Mellitus Tipo 2/sangue , Fibrinogênio/análise , Infecções por HIV/complicações , Treonina/sangue , Triptofano/sangue , Fator de von Willebrand/análise , Estudos Transversais , Diabetes Mellitus Tipo 2/diagnóstico , Diabetes Mellitus Tipo 2/etiologia , Feminino , HIV/isolamento & purificação , Infecções por HIV/virologia , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Risco
16.
Anal Biochem ; 574: 7-14, 2019 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-30885797

RESUMO

The development of a validated method, applicable for the measurement of tryptophan (TRP) and serotonin (5-HT), and that of the neuroprotective branch of the kynurenine pathway from several different biological matrices, including mouse brain, is described. Following the spectral analysis of the metabolites, they were quantified with reversed-phase high-performance liquid chromatography (HPLC), using separate internal standards (ISs) for UV (3-nitro-L-tyrosine) and fluorescent (the newly utilized 4-hydroxyquinazoline-2-carboxylic acid) detectors. With regard to validation parameters, selectivity, linearity, limit of detection, limit of quantification, precision and recovery were determined. Although the linearity ranges were different for the assessed matrices, the correlation coefficient was >0.999 in each case. Furthermore, good intra- and inter-day precision values were obtained with coefficient of variation <5%, and bias <6.5% (except the 5-HT level in brain samples), respectively. The recoveries varied between 82.5% and 116%. The currently developed methods yield opportunities for the assessment of concentration changes in the TRP metabolism from a wide range of biological matrices, therefore they may well be utilized in future clinical and preclinical studies, especially in view that so many metabolites with the application of ISs have not been detected from mouse brain with such a simple HPLC method before.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Triptofano/metabolismo , Animais , Encéfalo/metabolismo , Calibragem , Ácido Cinurênico/sangue , Ácido Cinurênico/metabolismo , Limite de Detecção , Camundongos , Camundongos Endogâmicos C57BL , Padrões de Referência , Reprodutibilidade dos Testes , Serotonina/sangue , Serotonina/metabolismo , Espectrofotometria Ultravioleta/métodos , Triptofano/sangue , Triptofano/normas
17.
Artigo em Inglês | MEDLINE | ID: mdl-30836315

RESUMO

l-Tryptophan (Trp) metabolites and related neurotransmitters play crucial roles in physiological functions, and their imbalances are implicated in the pathology of depression, Alzheimer's disease and other diseases. Measurement of Trp metabolites and related neurotransmitters possesses a great potential to elucidate the disease mechanisms and evaluate the outcomes of therapeutic interventions. A simple, rapid, sensitive and specific liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed for simultaneous determination of Trp, l-kynurenine (Kyn), kynurenic acid (Kyna), 3-hydroxykynurenine (3-HK), 5-hydroxytryptamine (5-HT), 5-hydroxyindoleacetic acid (5-HIAA), norepinephrine (NE), l-glutamic acid (Glu), γ-aminobutyric acid (GABA) and acetylcholine (ACh) in mice serum and the brain tissues in a single chromatographic run. Samples were spiked with the internal standard, mixed with trifluoroacetic acid to precipitate protein and analyzed by LC-MS/MS. Chromatographic separation was achieved using a Restek Ultra Aqueous C18 column in combination with a gradient elution within 8 min. Mass spectrometric detection was performed using multiple reaction monitoring with electrospray ionization source in positive mode. The method exhibited good selectivity and correlation coefficient values for the calibration curves of each analyte were >0.99. The limit of detection and quantification ranged from 0.96 to 24.48 nmol/L and 3.42 to 244.82 nmol/L, respectively. The intra- and inter-day precision were ≤13.92%. All analytes were stable in prepared samples at room temperature in the autosampler for 24 h. This method was successfully applied to the analysis of biological samples from control and chronic mild stress (CMS) induced depression mice. It was found that Kyn and 3-HK pathways were enhanced by CMS, while the levels of Trp, Kyna, 5-HIAA, Glu, GABA and ACh were significantly reduced. The changes in 5-HT and NE levels were not uniform in the periphery and the brain. This method can therefore be applied to analyze Trp metabolites and related neurotransmitters levels to monitor disease states, study the mechanisms and outcomes of therapeutic interventions.


Assuntos
Química Encefálica/fisiologia , Cromatografia Líquida/métodos , Neurotransmissores/análise , Espectrometria de Massas em Tandem/métodos , Triptofano/análise , Animais , Limite de Detecção , Modelos Lineares , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Neurotransmissores/sangue , Neurotransmissores/metabolismo , Reprodutibilidade dos Testes , Triptofano/sangue , Triptofano/metabolismo
18.
BMC Neurol ; 19(1): 37, 2019 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-30849952

RESUMO

BACKGROUND: Studies have shown positive effects of therapeutic exercise on motor- and cognitive function as well as on psychosocial outcomes in persons with multiple sclerosis (MS). A reduction of inflammatory stress through physical exercise has been suspected as one key mechanism, mediating the positive effects of exercise in the context of MS. The primary objective of this trial is to investigate the acute and chronic effects of different exercise modalities on (anti-)inflammatory immune signalling as well as on cognitive and functional capacity in persons with MS. METHODS: A two armed single-blind randomized controlled design will investigate 72 persons with relapsing remitting or secondary progressive MS (EDSS 3.0-6.0), during 3 weeks of inpatient rehabilitation. Participants will be randomized into either a high-intensity interval training (HIIT) or a moderate continuous training group; the latter represents the local standard therapy (ST). Both groups will exercise 3x per week. The HIIT group will perform 5 × 1.5-min high-intensive exercise bouts at 95-100% of their maximum heart rate (HRmax) followed by active breaks of unloaded pedalling (60% HRmax) for 2 min. In contrast, the ST group will exercise for 24 min continuously at 65% of HRmax. The proportion of circulating regulatory T-cells will be measured as primary outcome. Secondary outcomes comprise numbers and proportions of further immune cells including Th17-cells, soluble factors ((anti-) inflammatory cytokines, tryptophan metabolites), endurance capacity, cognitive performance, processing skills for activities of daily living, fatigue, depression and healthcare-related quality of life. Outcomes will be assessed before (T0) and after (T3) the 3-week exercise intervention program. Blood samples of T0 will be taken immediately before the first exercise session. Additionally, blood samples for the soluble factors will be collected immediately after (T1) and three hours (T2) after the first exercise session of each group. DISCUSSION: This study will be the first to investigate both acute and chronic effects of aerobic exercise on immune function and disease associated biomarkers in persons with MS. Combining biological analyses with cognitive and functional capacity assessments may contribute to a better understanding of responses to rehabilitative training, needed to improve exercise recommendations for persons with MS. TRIAL REGISTRATION: This trial was prospectively registered at ClinicalTrials.gov ( NCT03652519 ; 29 August 2018).


Assuntos
Cognição , Terapia por Exercício/métodos , Treinamento Intervalado de Alta Intensidade , Esclerose Múltipla Crônica Progressiva/reabilitação , Esclerose Múltipla Recidivante-Remitente/reabilitação , Atividades Cotidianas , Adulto , Biomarcadores/sangue , Citocinas/sangue , Tolerância ao Exercício , Fadiga/etiologia , Fadiga/prevenção & controle , Humanos , Esclerose Múltipla Crônica Progressiva/imunologia , Esclerose Múltipla Crônica Progressiva/psicologia , Esclerose Múltipla Recidivante-Remitente/imunologia , Esclerose Múltipla Recidivante-Remitente/psicologia , Qualidade de Vida , Método Simples-Cego , Linfócitos T Reguladores/metabolismo , Células Th17/metabolismo , Fatores de Tempo , Resultado do Tratamento , Triptofano/sangue
19.
J Pharm Biomed Anal ; 168: 30-37, 2019 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-30784887

RESUMO

Detection of amino acids (AAs) in blood is helpful to diagnose some diseases. In this work, a method is developed for determination of trace amounts of AAs in bovine blood by combining solid phase extraction (SPE) and capillary electrophoresis (CE). Zeolitic imidazolate framework-8 (ZIF-8) nanoparticles are prepared and used as adsorbents to simultaneously extract three AAs (tryptophan, tyrosine, phenylalanine). Under the optimum extraction conditions, the extraction efficiencies of ZIF-8 for AAs are 95.1% (tryptophan), 91.1% (tyrosine), and 90.1% (phenylalanine), respectively. Interestingly, ZIF-8 demonstrates good extraction ability for AAs in high concentration of acetonitrile (ACN) aqueous solutions. Thus, they can be directly used to extract AAs from the deproteinized blood sample using ACN. An α-cyclodextrin-mediated cation selective exhaustive injection-sweeping CE method is developed for analysis of the extracted AAs. The detection limits for AAs range from 0.13 to 0.37 µg mL-1 using the SPE/CE method. Standard addition method is used to evaluate the feasibility of the method in bovine blood samples. The standard addition curves demonstrate good linearity with determination coefficient > 0.9912.


Assuntos
Imidazóis/química , Fenilalanina/análise , Triptofano/análise , Tirosina/análise , Animais , Bovinos , Eletroforese Capilar/métodos , Limite de Detecção , Nanopartículas , Fenilalanina/sangue , Extração em Fase Sólida/métodos , Triptofano/sangue , Tirosina/sangue , Zeolitas/química
20.
Chem Commun (Camb) ; 55(21): 3156-3159, 2019 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-30801096

RESUMO

Room temperature phosphorescent (RTP) γ-CD-CB[6]-cowheeled [4]rotaxanes were synthesized by implanting a naphthalene axle into the cavity of iodine-substituted γ-CDs. The strong green RTP was quenched exclusively by Trp while no RTP quenching was observed with other major physiological amino acids or with the Trp-containing protein HSA, demonstrating a highly specific sensing of free Trp.


Assuntos
Hidrocarbonetos Aromáticos com Pontes/química , Imidazóis/química , Substâncias Luminescentes/química , Rotaxanos/química , Triptofano/análise , gama-Ciclodextrinas/química , Hidrocarbonetos Aromáticos com Pontes/síntese química , Humanos , Imidazóis/síntese química , Substâncias Luminescentes/síntese química , Medições Luminescentes/métodos , Rotaxanos/síntese química , Temperatura Ambiente , Triptofano/sangue , gama-Ciclodextrinas/síntese química
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