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1.
Int J Nanomedicine ; 14: 4991-5015, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31371943

RESUMO

Purpose: This study evaluates the cytotoxicity of AuNPs coated with polyallylamine (AuNPs-PAA) and conjugated or not to the epidermal growth factor receptor (EGFR)-targeting antibody Cetuximab (AuNPs-PAA-Ctxb) in normal human kidney (HK-2), liver (THLE-2) and microvascular endothelial (TIME) cells, and compares it with two cancer cell lines that are EGFR-overexpressing (A431) or EGFR-negative (MDA-MB-453). Results: Conjugation of Cetuximab to AuNPs-PAA increased the AuNPs-PAA-Ctxb interactions with cells, but reduced their cytotoxicity. TIME cells exhibited the strongest reduction in viability after exposure to AuNPs-PAA(±Ctxb), followed by THLE-2, MDA-MB-453, HK-2 and A431 cells. This cell type-dependent sensitivity was strongly correlated to the inhibition of thioredoxin reductase (TrxR) and glutathione reductase (GR), and to the depolarization of the mitochondrial membrane potential. Both are suggested to initiate apoptosis, which was indeed detected in a concentration- and time-dependent manner. The role of oxidative stress in AuNPs-PAA(±Ctxb)-induced cytotoxicity was demonstrated by co-incubation of the cells with N-acetyl L-cysteine (NAC), which significantly decreased apoptosis and mitochondrial membrane depolarization. Conclusion: This study helps to identify the cells and tissues that could be sensitive to AuNPs and deepens the understanding of the risks associated with the use of AuNPs in vivo.


Assuntos
Antioxidantes/metabolismo , Ouro/química , Nanopartículas Metálicas/química , Acetilcisteína/farmacologia , Apoptose/efeitos dos fármacos , Caspase 3/metabolismo , Caspase 7/metabolismo , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Cetuximab/farmacologia , Endocitose/efeitos dos fármacos , Glutationa Redutase/metabolismo , Humanos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Nanopartículas Metálicas/ultraestrutura , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Tamanho da Partícula , Poliaminas/química , Substâncias Protetoras/farmacologia , Eletricidade Estática , Tiorredoxina Dissulfeto Redutase/metabolismo
2.
Biomed Khim ; 65(3): 165-179, 2019 Apr.
Artigo em Russo | MEDLINE | ID: mdl-31258141

RESUMO

Monocytes and macrophages play a key role in the development of inflammation: under the action of lipopolysaccharides (LPS), absorbed from the intestine, monocytes and macrophages form reactive oxygen species (ROS) and cytokines, this leads to the development of oxidative stress, inflammation and/or apoptosis in all types of tissues. In the cells LPS induce an "internal" TLR4-mediated MAP-kinase inflammatory signaling pathway and cytokines through the superfamily of tumor necrosis factor receptor (TNFR) and the "death domain" (DD) initiate an "external" caspase apoptosis cascade or necrosis activation that causes necroptosis. Many of the proteins involved in intracellular signaling cascades (MYD88, ASK1, IKKa/b, NF-kB, AP-1) are redox-sensitive and their activity is regulated by antioxidants thioredoxin, glutaredoxin, nitroredoxin, and glutathione. Oxidation of these signaling proteins induced by ROS enhances the development of inflammation and apoptosis, and their reduction with antioxidants, on the contrary, stabilizes the signaling cascades speed, preventing the vicious circle of oxidative stress, inflammation and apoptosis that follows it. Antioxidant (AO) enzymes thioredoxin reductase (TRXR), glutaredoxin reductase (GLRXR), glutathione reductase (GR) are required for reduction of non-enzymatic antioxidants (thioredoxin, glutaredoxin, nitroredoxin, glutathione), and AO enzymes (SOD, catalase, GPX) are required for ROS deactivation. The key AO enzymes (TRXR and GPX) are selenium-dependent; therefore selenium deficiency leads to a decrease in the body's antioxidant defense, the development of oxidative stress, inflammation, and/or apoptosis in various cell types. Nrf2-Keap1 signaling pathway activated by selenium deficiency and/or oxidative stress is necessary to restore redox homeostasis in the cell. In addition, expression of some genes is changed with selenium deficiency. Consequently, growth and proliferation of cells, their movement, development, death, and survival, as well as the interaction between cells, the redox regulation of intracellular signaling cascades of inflammation and apoptosis, depend on the selenium status of the body. Prophylactic administration of selenium-containing preparations (natural and synthetic (organic and inorganic)) is able to normalize the activity of AO enzymes and the general status of the body. Organic selenium compounds have a high bioavailability and, depending on their concentration, can act both as selenium donors to prevent selenium deficiency and as antitumor drugs due to their toxicity and participation in the regulation of signaling pathways of apoptosis. Known selenorganic compounds diphenyldiselenide and ethaselen share similarity with the Russian organo selenium compound, diacetophenonylselenide (DAPS-25), which serves as a source of bioavailable selenium, exhibits a wide range of biological activity, including antioxidant activity, that governs cell redox balance, inflammation and apoptosis regulation.


Assuntos
Apoptose , Inflamação/metabolismo , Estresse Oxidativo , Compostos de Selênio/metabolismo , Antioxidantes/metabolismo , Glutationa Redutase/metabolismo , Humanos , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Oxirredução , Espécies Reativas de Oxigênio/metabolismo , Selênio , Transdução de Sinais , Tiorredoxina Dissulfeto Redutase/metabolismo
3.
J Agric Food Chem ; 67(22): 6432-6444, 2019 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-31095381

RESUMO

Liquid feeding strategies have been devised with the aim of enhancing grain nutrient availability for livestock. It is characterized by a steeping/soaking period that softens the grains and initiates mobilization of seed storage reserves. The present study uses 2D gel-based proteomics to investigate the role of proteolysis and reduction by thioredoxins over a 48 h steeping period by monitoring protein abundance dynamics in barley-based liquid feed samples supplemented with either protease inhibitors or NADPH-dependent thioredoxin reductase/thioredoxin (NTR/Trx). Several full-length storage proteins were only identified in the water-extractable fraction of feed containing protease inhibitors, illustrating significant inhibition of proteolytic activities arising during the steeping period. Application of functional NTR/Trx to liquid feed reductively increased the solubility of known and potentially new Trx-target proteins, e.g., outer membrane protein X, and their susceptibility to proteolysis. Thus, the NTR/Trx system exhibits important potential as a feed additive to enhance nutrient digestibility in monogastric animals.


Assuntos
Ração Animal/análise , Hordeum/enzimologia , Proteínas de Plantas/química , Tiorredoxina Dissulfeto Redutase/química , Tiorredoxinas/química , Eletroforese em Gel Bidimensional , Manipulação de Alimentos , Hordeum/química , Extratos Vegetais/química , Extratos Vegetais/metabolismo , Proteínas de Plantas/metabolismo , Inibidores de Proteases/química , Inibidores de Proteases/metabolismo , Proteômica , Sementes/química , Sementes/enzimologia , Tiorredoxina Dissulfeto Redutase/metabolismo , Tiorredoxinas/metabolismo
4.
Gene ; 706: 32-42, 2019 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-31028868

RESUMO

The chloroplastic thioredoxins (Trxs), a family of thiol-disulphide oxidoreductases, are reduced by either ferredoxin (Fd)-dependent Trx reductase (FTR) or reduced nicotinamide adenine dinucleotide phosphate (NADPH)-dependent Trx reductase (NTR). Two Trx systems are present in chloroplasts including Trxs, Trx-like proteins, and reductase FTR and NTRC. FTR is the main reductant for Trxs in chloroplasts, while the flavoprotein NTRC integrates NTR and Trx activity, and plays multiple roles in the Calvin cycle, the oxidative pentose phosphate pathway (OPPP), anti-peroxidation, tetrapyrrole metabolism, ATP and starch synthesis, and photoperiodic regulation. In addition, not only there exists a reduction potential transfer pathway across the thylakoid membrane, but also FTR and NTRC coordinate with each other to regulate chloroplast redox homeostasis. Herein, we summarise the physiological functions of these two Trx reduction systems, discuss how both regulate redox homeostasis in plant plastids, and emphasize the significance of chloroplast thioredoxin systems in maintaining photosynthetic efficiency in plants.


Assuntos
Cloroplastos/metabolismo , Tiorredoxina Dissulfeto Redutase/fisiologia , Tiorredoxinas/fisiologia , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Cloroplastos/fisiologia , Ferredoxinas/metabolismo , Proteínas com Ferro-Enxofre , Oxirredução , Oxirredutases/metabolismo , Peroxirredoxinas/metabolismo , Fotossíntese/fisiologia , Plastídeos/metabolismo , Tiorredoxina Dissulfeto Redutase/metabolismo , Tiorredoxinas/metabolismo
5.
Chem Pharm Bull (Tokyo) ; 67(3): 186-191, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30827998

RESUMO

Gold compounds have a long history of use in medicine. Auranofin was developed more than 30 years ago as an oral therapy for rheumatoid arthritis. Now, however, auranofin is rarely used in clinical practice despite its efficacy for treating rheumatoid arthritis because more novel antirheumatic medications are available. Although its use in clinical practice has decreased, studies on auranofin have continued and it shows promise for the treatment of several different diseases, including cancer and bacterial and parasitic infections. Several potential novel applications of auranofin for treating human disease have been proposed. Auranofin inhibits the activity of thioredoxin reductase (TrxR), an enzyme of the thioredoxin (Trx) system that is important for maintaining the intracellular redox state. Particularly in cancers, TrxR inhibition leads to an increase in cellular oxidative stress and induces apoptosis. TrxR overexpression is associated with aggressive tumor progression and poor survival in patients with breast, ovarian, and lung cancers. The Trx system may represent an attractive target for the development of new cancer treatments. Therefore, the TrxR inhibitor auranofin may be a potent anticancer agent. This review summarizes the current understanding of auranofin for cancer therapy.


Assuntos
Antineoplásicos/farmacologia , Auranofina/farmacologia , Animais , Apoptose/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Humanos , Neoplasias/enzimologia , Neoplasias/metabolismo , Neoplasias/patologia , Oxirredução , Estresse Oxidativo/efeitos dos fármacos , Tiorredoxina Dissulfeto Redutase/antagonistas & inibidores , Tiorredoxina Dissulfeto Redutase/metabolismo , Tiorredoxinas/metabolismo
6.
Oxid Med Cell Longev ; 2019: 2471312, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30906501

RESUMO

Accumulation of oxidative insults on molecular and supramolecular levels could compromise renewal potency and architecture in the aging skin. To examine and compare morphological and ultrastructural changes with redox alterations during chronological skin aging, activities of antioxidant defense (AD) enzymes, superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), glutathione reductase (GR), thioredoxin reductase (TR), and methionine sulfoxide reductase A (MsrA), and the markers of oxidative damage of biomolecules-4-hydroxynonenal (HNE) and 8-oxoguanine (8-oxoG)-were examined in the rat skin during life (from 3 days to 21 months). As compared to adult 3-month-old skin, higher activities of CAT, GSH-Px, and GR and a decline in expression of MsrA are found in 21-month-old skin. These changes correspond to degenerative changes at structural and ultrastructural levels in epidermal and dermal compartments, low proliferation capacity, and higher levels of HNE-modified protein aldehydes (particularly in basal lamina) and 8-oxoG positivity in nuclei and mitochondria in the sebaceous glands and root sheath. In 3-day-old skin, higher activities of AD enzymes (SOD, CAT, GR, and TR) and MsrA expression correspond to intensive postnatal development and proliferation. In contrast to 21-month-old skin, a high level of HNE in young skin is not accompanied by 8-oxoG positivity or any morphological disturbances. Observed results indicate that increased activity of AD enzymes in elderly rat skin represents the compensatory response to accumulated oxidative damage of DNA and proteins, accompanied by attenuated repair and proliferative capacity, but in young rats the redox changes are necessary and inherent with processes which occur during postnatal skin development. Мorphological and ultrastructurаl changes are in line with the redox profile in the skin of young and old rats.


Assuntos
Envelhecimento/metabolismo , Pele/metabolismo , Pele/patologia , Aldeídos/metabolismo , Animais , Catalase/metabolismo , Proliferação de Células , Colágeno/ultraestrutura , Dano ao DNA , Desoxiguanosina/análogos & derivados , Desoxiguanosina/metabolismo , Fibroblastos/ultraestrutura , Glutationa Peroxidase/metabolismo , Glutationa Redutase/metabolismo , Masculino , Oxirredução , Oxirredutases/metabolismo , Antígeno Nuclear de Célula em Proliferação/metabolismo , Ratos Wistar , Pele/enzimologia , Pele/ultraestrutura , Superóxido Dismutase/metabolismo , Tiorredoxina Dissulfeto Redutase/metabolismo , Fatores de Tempo
7.
Biochimie ; 160: 1-13, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30710560

RESUMO

The redox homeostasis of cytoplasm is maintained by a series of disulfide exchange reactions mediated by proteins belonging to the thioredoxin superfamily. Thioredoxin and thioredoxin reductase, being the major members of the family, play a key role in oxidative stress response of Staphylococcus aureus. In this report, we have identified and characterised an active thioredoxin system of the mentioned pathogen. Crystal structure of thioredoxin2 (SaTrx2) in its reduced form reveals that it contains the conserved redox active WCXXC motif and a thioredoxin fold. Thioredoxin reductase2 (SaTR2) is a flavoprotein and consists of two Rossmann folds as the binding sites for FAD and NADPH. Crystal structure of the SaTR2 holoenzyme shows that the protein consists of two domains and the catalytic site comprises of an intramolecular disulfide bond formed between two sequentially distal cysteine residues. Biophysical and biochemical studies unveil that SaTrx2 and SaTR2 can physically interact in solution and in the course of sustaining the redox equilibrium, the latter reduces the former. Molecular docking has been performed to illustrate the interface formed between SaTrx2 and SaTR2 during the disulfide exchange reaction.


Assuntos
Dissulfetos/metabolismo , Conformação Proteica , Staphylococcus aureus/metabolismo , Tiorredoxina Dissulfeto Redutase/metabolismo , Tiorredoxinas/metabolismo , Sítios de Ligação , Domínio Catalítico , Cristalografia por Raios X , Dissulfetos/química , Modelos Moleculares , Mutagênese Sítio-Dirigida , Mutação , NADP/metabolismo , Oxirredução , Especificidade por Substrato , Tiorredoxina Dissulfeto Redutase/química , Tiorredoxina Dissulfeto Redutase/genética , Tiorredoxinas/química
8.
J Microbiol ; 57(2): 138-142, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30706342

RESUMO

Thermococcus onnurineus NA1, an obligate anaerobic hyperthermophilic archaeon, showed variable oxygen (O2) sensitivity depending on the types of substrate employed as an energy source. Unexpectedly, the culture with yeast extract as a sole energy source showed enhanced growth by 2-fold in the presence of O2. Genome-wide transcriptome analysis revealed the upregulation of several antioxidant-related genes encoding thioredoxin peroxidase (TON_0862), rubrerythrin (TON_0864), rubrerythrin-related protein (TON_0873), NAD(P)H rubredoxin oxidoreductase (TON_0865), or thioredoxin reductase (TON_1603), which can couple the detoxification of reactive oxygen species with the regeneration of NAD(P)+ from NAD(P)H. We present a plausible mechanism by which O2 serves to maintain the intracellular redox balance. This study demonstrates an unusual strategy of an obligate anaerobe underlying O2-mediated growth enhancement despite not having heme-based or cytochrome-type proteins.


Assuntos
Oxigênio/metabolismo , Thermococcus/enzimologia , Thermococcus/crescimento & desenvolvimento , Thermococcus/genética , Antioxidantes , Proteínas Arqueais/genética , Proteínas Arqueais/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Citocromos/genética , Citocromos/metabolismo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica em Archaea , Genes Arqueais/genética , Hemeproteínas/genética , Hemeproteínas/metabolismo , Hemeritrina/genética , Hemeritrina/metabolismo , NAD/metabolismo , NADH NADPH Oxirredutases/genética , NADH NADPH Oxirredutases/metabolismo , Oxirredução , Peroxirredoxinas/genética , Peroxirredoxinas/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Espécies Reativas de Oxigênio/toxicidade , Rubredoxinas/genética , Rubredoxinas/metabolismo , Thermococcus/metabolismo , Tiorredoxina Dissulfeto Redutase/genética , Tiorredoxina Dissulfeto Redutase/metabolismo , Transcriptoma , Regulação para Cima
9.
J Ind Microbiol Biotechnol ; 46(2): 241-248, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30604236

RESUMO

Among the Corynebacterium glutamicum ORFs that have been implicated in stress responses, we chose ORF cg3230, designated osnR, and analyzed it further. Unlike the osnR-deleted strain (ΔosnR), the osnR-overexpressing strain (P180-osnR) developed growth defects and increased sensitivity to various oxidants including H2O2. Transcription in the P180-osnR strain of genes such as sodA (superoxide dismutase), ftn (ferritin biosynthesis), and ahpD (alkyl hydroperoxide reductase; cg2674), which are involved in the detoxification of reactive oxygen species, was only 40% that of the wild type. However, transcription of katA, encoding H2O2-detoxifying catalase, was unchanged in this strain. Genes such as trxB (thioredoxin reductase) and mtr (mycothiol disulfide reductase), which play roles in redox homeostasis, also showed decreased transcription in the strain. 2D-PAGE analysis indicated that genes involved in redox reactions were considerably affected by osnR overexpression. The NADPH/NADP+ ratio of the P180-osnR strain (1.35) was higher than that of the wild-type stain (0.78). Collectively, the phenotypes of the ΔosnR and P180-osnR strains suggest a global regulatory role as well as a negative role for the gene in stress responses, particularly in katA-independent oxidative stress responses.


Assuntos
Corynebacterium glutamicum/genética , Genes Bacterianos , Estresse Oxidativo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Corynebacterium glutamicum/metabolismo , Regulação Bacteriana da Expressão Gênica , Homeostase , Peróxido de Hidrogênio/metabolismo , NADH NADPH Oxirredutases/genética , NADH NADPH Oxirredutases/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Tiorredoxina Dissulfeto Redutase/genética , Tiorredoxina Dissulfeto Redutase/metabolismo
10.
Aquat Toxicol ; 208: 90-97, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30639982

RESUMO

Global scale concerns regarding rise in microplastics pollution in the environment have recently aroused. Ingestion of microplastics by biota, including freshwater zooplankton has been well studied, however, despite keystone species in freshwater food webs, the molecular response (e.g. oxidative defense) of zooplankton in response to microplastics is still in its infancy. The thioredoxin (TRx) system has a vital function in cellular antioxidative defense via eliminating the excessive generation of reactive oxygen species (ROS). Therefore, it is necessary to investigate the effects of thioredoxin reductase (TRxR), due to its triggering the TRx catalysis cascade. The present study identified TRxR in Daphnia magna (Dm-TRxR) for the first time, and found that the full-length cDNA was 1862 bp long, containing an 1821-bp open reading frame. Homologous alignments showed the presence of conserved catalytic domain CVNVGC and the seleocysteine (SeCys) residue (U) located in the N- and C- terminal portions. Subsequently, the expression of Dm-TRxR, together with permease, arginine kinase (AK), was investigated by approach of quantitative real-time PCR after exposure to four (1.25-µm) polystyrene (PS) microbeads concentrations: 0 (control), 2, 4 and 8 mg L-1 for 10 days. Dm-TRxR, permease and AK mRNA were significantly upregulated after exposure to 2, 4 mg L-1 of PS, but then declined in the presence of 8 mg L-1 PS. The gene expression results suggested that oxidative defense, energy production and substance extra cellular transportation were significantly regulated by microplastic exposure. Collectively, the present study will advance our knowledge regarding the biological effects of microplastic pollution on zooplankton, and builds a foundation for freshwater environmental studies on mechanistic and biochemical responses to microplastics.


Assuntos
Daphnia/enzimologia , Daphnia/genética , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Plásticos/toxicidade , Poliestirenos/toxicidade , Tiorredoxina Dissulfeto Redutase/genética , Motivos de Aminoácidos , Sequência de Aminoácidos , Animais , Arginina Quinase/metabolismo , Sequência de Bases , Daphnia/efeitos dos fármacos , Daphnia/crescimento & desenvolvimento , Perfilação da Expressão Gênica , Proteínas de Membrana Transportadoras/metabolismo , Domínios Proteicos , Estrutura Terciária de Proteína , Análise de Sequência de Proteína , Tiorredoxina Dissulfeto Redutase/química , Tiorredoxina Dissulfeto Redutase/metabolismo , Poluentes Químicos da Água/toxicidade
11.
Physiol Plant ; 166(1): 211-225, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30578537

RESUMO

In natural growth habitats, plants face constant, unpredictable changes in light conditions. To avoid damage to the photosynthetic apparatus on thylakoid membranes in chloroplasts, and to avoid wasteful reactions, it is crucial to maintain a redox balance both within the components of photosynthetic electron transfer chain and between the light reactions and stromal carbon metabolism under fluctuating light conditions. This requires coordinated function of the photoprotective and regulatory mechanisms, such as non-photochemical quenching (NPQ) and reversible redistribution of excitation energy between photosystem II (PSII) and photosystem I (PSI). In this paper, we show that the NADPH-dependent chloroplast thioredoxin system (NTRC) is involved in the control of the activation of these mechanisms. In plants with altered NTRC content, the strict correlation between lumenal pH and NPQ is partially lost. We propose that NTRC contributes to downregulation of a slow-relaxing constituent of NPQ, whose induction is independent of lumenal acidification. Additionally, overexpression of NTRC enhances the ability to adjust the excitation balance between PSII and PSI, and improves the ability to oxidize the electron transfer chain during changes in light conditions. Thiol regulation allows coupling of the electron transfer chain to the stromal redox state during these changes.


Assuntos
Cloroplastos/metabolismo , Tiorredoxina Dissulfeto Redutase/metabolismo , NADP/metabolismo , Fotossíntese/fisiologia , Complexo de Proteína do Fotossistema I/metabolismo , Complexo de Proteína do Fotossistema II/metabolismo
12.
Med Res Rev ; 39(1): 5-39, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-29727025

RESUMO

Mammalian thioredoxin reductase (TrxR) enzymes are homodimeric flavin proteins sharing a unique yet essential selenocysteine residue at their C-terminus. TrxRs, together with their endogenous substrate thioredoxins, play a crucial role in regulating diverse cellular redox events. A wealth of evidence from both clinic observations and bench studies supports that overactivation/dysfunction of TrxRs has a close link to the onset and development of various diseases, such as cancer and neurodegeneration. Thus, an increasing interest has been attracted to find small molecule modulators of TrxRs during the past years. Herein, we briefly discussed the relevance of targeting TrxRs inhibition for cancer treatment, and presented the small molecule inhibitors of mammalian TrxRs published in the nonpatent literatures from 2011 to 2016. The mechanisms of inhibition by different classes of molecules were summarized, and some inhibitors with promising anticancer activity were further discussed. We expect this work would be a comprehensive reference in the medicinal chemistry, and have a broad audience across multiple disciplines.


Assuntos
Antineoplásicos/farmacologia , Inibidores Enzimáticos/farmacologia , Mamíferos/metabolismo , Bibliotecas de Moléculas Pequenas/farmacologia , Tiorredoxina Dissulfeto Redutase/antagonistas & inibidores , Animais , Antineoplásicos/química , Inibidores Enzimáticos/química , Humanos , Bibliotecas de Moléculas Pequenas/química , Tiorredoxina Dissulfeto Redutase/metabolismo
13.
Exp Mol Pathol ; 105(1): 32-36, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29852184

RESUMO

OBJECTIVE: Primary Sclerosing Cholangitis (PSC) is a severe cholestatic liver disease characterized by progressive peri-biliary tract inflammation, elevated oxidative stress and hepatocellular injury. A hallmark of PSC patients is the concurrent diagnosis of Inflammatory Bowel Disease occurring in approximately 70%-80% of PSC patients (PSC/IBD). We previously reported dysregulation of key anti-oxidant pathways in PSC/IBD. The objective of this study was to expand previous data by examining the abundance of thioredoxins (Trx) in PSC/IBD. METHODS: Using hepatic tissue and whole cell extracts isolated from age-matched healthy humans and patients diagnosed with end stage PSC/IBD, the protein abundance of thioredoxin, thioredoxin reductase (TrxR1), and their downstream substrates peroxiredoxins was assessed. RESULTS: Western blot analyses of thioredoxin and peroxiredoxin abundance revealed significant increases in abundance of Trx1 and TrxR1 whereas expression of thioredoxin-interacting protein was significantly decreased in PSC/IBD. Concurrently, abundance of cytosolic peroxiredoxins was not significantly impacted. The abundance of mitochondrial Trx2, along with peroxiredoxins 3, 5 and 6 were significantly decreased by concurrent PSC/IBD. Histological staining of Trx1/TrxR1 revealed elevated nuclear Trx1 and TrxR1 staining within cholangiocytes as well as an overall periportal increase in expression in PSC/IBD. An examination of additional anti-oxidant responses reveal suppression of gamma-glutamylcysteine synthetase and heme oxygenase (HO-1) whereas expression of the protein chaperone glucose regulated protein 78 increased suggesting elevated cellular stress in PSC/IBD. CONCLUSIONS: Results herein suggest that in addition to severe dysregulation of anti-oxidant responses, cholestasis impacts both cytosolic/nuclear (Trx1) as well as mitochondrial (Trx2) redox signaling and control pathways.


Assuntos
Colestase/metabolismo , Doenças Inflamatórias Intestinais/metabolismo , Peroxirredoxinas/genética , Tiorredoxina Dissulfeto Redutase/genética , Tiorredoxinas/genética , Estudos de Casos e Controles , Colestase/complicações , Colestase/genética , Heme Oxigenase-1/genética , Heme Oxigenase-1/metabolismo , Humanos , Doenças Inflamatórias Intestinais/complicações , Doenças Inflamatórias Intestinais/genética , Fígado/metabolismo , Estresse Oxidativo , Peroxirredoxinas/metabolismo , Transdução de Sinais , Tiorredoxina Dissulfeto Redutase/metabolismo , Tiorredoxinas/metabolismo
14.
Eur J Pharmacol ; 833: 131-144, 2018 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-29807031

RESUMO

Epilepsy is one of the furthermost common neurodegenerative diseases affecting above 50 million individuals worldwide. The pathogenesis of epileptic seizures is not satisfactorily explored, and hence more effective anti-convulsive therapies are indispensable. Current study aimed to investigate the mechanisms of the potential neuroprotective effects of sildenafil/selenium on chemically-induced convulsions in mice. Kindling model was induced using pentylenetetrazol (PTZ; 35 mg/Kg, 11 doses, intraperitoneally, every other day). PTZ-insulted groups were treated intraperitoneally with sildenafil (20 mg/Kg), selenium (0.2 mg/Kg) or their combination; 30 min before PTZ administration. PTZ-kindled model showed a significant loss of neuronal cells concurrently with nitrative/oxidative stress and lipid peroxidation. This was associated with enhanced expression of inducible nitric oxide synthase (iNOS), hemeoxygenase-1 (HO-1) and vascular endothelial growth factor (VEGF) along with increased activity of thioredoxin reductase (TrxR) in hippocampal tissue. Individual treatment with sildenafil or selenium showed partial neuroprotection, simultaneously with lower hippocampal expression of 4-hydroneonenal (4-HNE), nitrotyrosine, iNOS and HO-1, yet without reaching normal levels. Sildenafil, but not selenium, enhanced the expression of VEGF and the endothelial cell marker CD34. The joint treatment with sildenafil and selenium preserved hippocampal neuronal count, improved kindling score, blunted lipid peroxides and nitrotyrosine levels, concomitantly with iNOS inhibition, normalization of TrxR activity and HO-1 expression, and evident neo-angiogenesis. Current study demonstrated the roles of several central signalling cascades in the sildenafil/selenium-evoked neuroprotection represented in, at least in part, amelioration of nitrative/oxidative stress alongside modulation of angiogenesis. Thus, sildenafil combined with selenium could be repurposed as a potential therapeutic regimen for delaying epilepsy progression.


Assuntos
Epilepsia/prevenção & controle , Excitação Neurológica/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Convulsões/prevenção & controle , Selênio/farmacologia , Citrato de Sildenafila/farmacologia , Animais , Hipocampo/efeitos dos fármacos , Hipocampo/patologia , Masculino , Camundongos , Neurônios/efeitos dos fármacos , Neurônios/patologia , Estresse Oxidativo/efeitos dos fármacos , Pentilenotetrazol , Selênio/sangue , Selênio/farmacocinética , Tiorredoxina Dissulfeto Redutase/metabolismo , Fator A de Crescimento do Endotélio Vascular
15.
Int J Biol Macromol ; 117: 878-889, 2018 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-29807076

RESUMO

In this study, a Se-deficient mice model was successfully developed by feeding a Se-deficient diet (0.02 mg Se/kg diet) for 4 weeks, and Se supplementation by Se-polysaccharides (Se-GFP-22) was lasted for 4 weeks. The immunomodulatory activity and Se supplementation of Se-GFP-22 from Se-enriched G. frondosa was investigated. Results showed that Se-GFP-22 remarkably enhanced glutathione peroxidase (GSH-Px) and thioredoxin reductase (TrxR) activities in liver, kidney and plasma, and serum, liver, spleen and kidney Se levels of Se-deficient mice. Se-GFP-22 increased the thymus and spleen indices, phagocytic index, co-mitogenic (ConA- or LPS-stimulated) activities on splenocytes and DTH reaction. Se-GFP-22 caused significant increments in cytokine (IL-1ß, TNF-α and IFN-γ) levels and Ig G, Ig A, Ig M and Ig E levels. Se-GFP-22 exhibited superior immunomodulatory effects than GFP-22. These findings indicated that Se-GFP-22 promote the protective effects against Se deficiency-induced immunosuppression and could be a potential immunomodulatory agent and a dietary Se-supplement.


Assuntos
Grifola/química , Tolerância Imunológica/efeitos dos fármacos , Polissacarídeos/química , Polissacarídeos/farmacologia , Selênio/química , Selênio/deficiência , Animais , Proliferação de Células/efeitos dos fármacos , Citocinas/sangue , Suplementos Nutricionais , Glutationa Peroxidase/metabolismo , Linfócitos/citologia , Linfócitos/efeitos dos fármacos , Camundongos , Fagocitose/efeitos dos fármacos , Tiorredoxina Dissulfeto Redutase/metabolismo , Timo/citologia , Timo/efeitos dos fármacos , Timo/imunologia
16.
Inorg Chem ; 57(9): 5575-5584, 2018 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-29688719

RESUMO

Thioredoxin (Trx) is an important enzyme in the redox signaling pathway and is usually overexpressed in tumor cells. We demonstrate herein that the photoactive platinum(IV) anticancer complex trans,trans,trans-[Pt(N3)2(OH)2(Py)2] (1) can bind to His, Glu, and Gln residues of Trx upon the irradiation of blue light. More importantly, complex 1 can also induce the oxidation of Met, Trp, and the Cys catalytic sites to form disulfide bonds by generating reactive oxygen species (ROS) upon photoactivation. These eventually lead to inhibition of activity of Trx enzyme and the Trx system and further increase in the cellular ROS level. We speculate that the oxidative damage not only inhibits Trx activity but also greatly contributes to the anticancer action of complex 1.


Assuntos
Antineoplásicos/farmacologia , Inibidores Enzimáticos/farmacologia , Compostos de Platina/farmacologia , Tiorredoxina Dissulfeto Redutase/antagonistas & inibidores , Tiorredoxinas/antagonistas & inibidores , Antineoplásicos/síntese química , Antineoplásicos/química , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Cristalografia por Raios X , Ensaios de Seleção de Medicamentos Antitumorais , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Humanos , Concentração de Íons de Hidrogênio , Modelos Moleculares , Estrutura Molecular , Oxirredução/efeitos dos fármacos , Compostos de Platina/síntese química , Compostos de Platina/química , Tiorredoxina Dissulfeto Redutase/metabolismo , Tiorredoxinas/metabolismo
17.
J Am Chem Soc ; 140(10): 3784-3790, 2018 03 14.
Artigo em Inglês | MEDLINE | ID: mdl-29509009

RESUMO

To understand how intracellular proteins respond to oxidative stresses, the redox status of the target protein, as well as the intracellular redox potential ( EGSH), which is defined by the concentrations of reduced and oxidized glutathione, should be observed simultaneously within living cells. In this study, we developed a method that can monitor the redox status of thioredoxin (Trx) and EGSH by direct NMR observation of Trx and glutathione within living cells. Unlike the midpoint potential of Trx measured in vitro (∼ -300 mV), the intracellular Trx exhibited the redox transition at EGSH between -250 and -200 mV, the range known to trigger the oxidative stress-mediated signalings. Furthermore, we quantified the contribution of Trx reductase to the redox status of Trx, demonstrating that the redox profile of Trx is determined by the interplay between the elevation of EGSH and the reduction by Trx reductase and other endogenous molecules.


Assuntos
Glutationa/metabolismo , Estresse Oxidativo , Tiorredoxina Dissulfeto Redutase/metabolismo , Tiorredoxinas/metabolismo , Reatores Biológicos , Glutationa/análise , Células HeLa , Humanos , Espectroscopia de Ressonância Magnética/métodos , Modelos Moleculares , Oxirredução , Tiorredoxina Dissulfeto Redutase/análise , Tiorredoxinas/análise
18.
Eur J Med Chem ; 150: 633-641, 2018 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-29558734

RESUMO

A series of 22 novel metronidazole-triazole-styryl hybrids were synthesized and evaluated for their in vitro antiamoebic activity against HM1: IMSS strain of Entamoeba histolytica. Some of the hybrids were found to be more active (IC50 = 0.12-0.35 µM) than the reference drug metronidazole (IC50 = 1.79 µM). The most active compounds were found to be non-toxic (up to 50 µM) against the Vero cells showing a good safety profile of these hybrids. The docking and ADMET studies were also conducted to investigate the probable mode of action. Docking studies showed significant binding affinity in the active site of E. histolytica thioredoxin reductase (EhTrR) protein.


Assuntos
Antiprotozoários/farmacologia , Entamoeba histolytica/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Metronidazol/farmacologia , Estireno/farmacologia , Triazóis/farmacologia , Antiprotozoários/síntese química , Antiprotozoários/química , Relação Dose-Resposta a Droga , Entamoeba histolytica/enzimologia , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Metronidazol/química , Simulação de Acoplamento Molecular , Estrutura Molecular , Testes de Sensibilidade Parasitária , Relação Estrutura-Atividade , Estireno/química , Tiorredoxina Dissulfeto Redutase/antagonistas & inibidores , Tiorredoxina Dissulfeto Redutase/metabolismo , Triazóis/química
19.
Biochem Biophys Res Commun ; 496(2): 648-653, 2018 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-29331374

RESUMO

It has been known that hydrogen sulfide and/or polysulfides are produced from a (poly)sulfurated sulfur-acceptor substrate of 3-mercaptopyruvate sulfurtransferase (MST) via thioredoxin (Trx) reduction in vitro. In this study, we used thiosulfate as the donor substrate and the catalytic reaction was terminated on the formation of a persulfide or polysulfides. We can present alternative pathway of production of hydrogen sulfide and/or polysulfides from (poly)sulfurated catalytic-site cysteine of reaction intermediates of MST via Trx reduction. Matrix-assisted laser desorption ionization tandem time-of-flight mass spectrometric analysis revealed that after prolonged incubation of MST with thiosulfate, a trisulfide adduct becomes predominant at the sulfurated catalytic-site cysteine. When these adducts were reduced by Trx with reducing system (MST:Escherichia coli Trx:E. coli Trx reductase:NADPH = 1:5:0.02:12.5 molar ratio), liquid chromatography with tandem mass spectrometric analysis for monobromobimane-derivatized H2Sn revealed that H2S2 first appeared, and then H2S and H2S3 did later. The results were confirmed by high-performance liquid chromatography-fluorescence analysis.


Assuntos
Cisteína/metabolismo , Sulfeto de Hidrogênio/metabolismo , Sulfetos/metabolismo , Sulfurtransferases/metabolismo , Animais , Escherichia coli/metabolismo , Proteínas de Escherichia coli/metabolismo , Oxirredução , Ratos , Proteínas Recombinantes/metabolismo , Tiorredoxina Dissulfeto Redutase/metabolismo , Tiorredoxinas/metabolismo
20.
Aquat Toxicol ; 196: 35-42, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29328974

RESUMO

Because of its widespread use, the pharmaceutical acetaminophen (APAP) is frequently detected in aquatic environments. APAP can have serious physiological effects, such as reduced reproduction, low growth rates, and abnormal behavior, in aquatic organisms. However, the methods available for evaluation of the aquatic toxicity of APAP are of limited usefulness. The present study aimed to develop reliable and sensitive markers for evaluation of APAP toxicity using Daphnia as a model organism. We focused on N-acetyl-p-benzoquinoneimine (NAPQI) production from APAP via cytochrome P450 metabolism because NAPQI causes APAP toxicity. Daphnia magna were exposed to APAP (0, 50, or 100 mg/L for 12 h or 24 h), and the total metabolites were extracted and analyzed for NAPQI. Direct detection of NAPQI was difficult because of its high reactivity, and its peak was close to that for APAP. Therefore, we tried to identify molecular and biochemical indicators associated with NAPQI generation, elimination, and its interactions with macromolecules. We identified changes in CYP370A13 gene expression, glutathione depletion, inhibition of thioredoxin reductase activity, and production of reactive oxygen species as indicators of D. magna exposure to APAP. These indicators could be used to develop sensitive and accurate techniques to evaluate the environmental toxicity of APAP.


Assuntos
Acetaminofen/toxicidade , Sistema Enzimático do Citocromo P-450/metabolismo , Daphnia/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Acetaminofen/análise , Acetaminofen/metabolismo , Animais , Benzoquinonas/análise , Benzoquinonas/toxicidade , Cromatografia Líquida de Alta Pressão , Sistema Enzimático do Citocromo P-450/genética , Daphnia/metabolismo , Expressão Gênica/efeitos dos fármacos , Glutationa/metabolismo , Iminas/análise , Iminas/toxicidade , Inativação Metabólica , Masculino , Espécies Reativas de Oxigênio/metabolismo , Tiorredoxina Dissulfeto Redutase/metabolismo
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