Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 3.362
Filtrar
1.
Nat Commun ; 11(1): 4055, 2020 08 13.
Artigo em Inglês | MEDLINE | ID: mdl-32792504

RESUMO

Although metastasis is the most common cause of cancer deaths, metastasis-intrinsic dependencies remain largely uncharacterized. We previously reported that metastatic pancreatic cancers were dependent on the glucose-metabolizing enzyme phosphogluconate dehydrogenase (PGD). Surprisingly, PGD catalysis was constitutively elevated without activating mutations, suggesting a non-genetic basis for enhanced activity. Here we report a metabolic adaptation that stably activates PGD to reprogram metastatic chromatin. High PGD catalysis prevents transcriptional up-regulation of thioredoxin-interacting protein (TXNIP), a gene that negatively regulates glucose import. This allows glucose consumption rates to rise in support of PGD, while simultaneously facilitating epigenetic reprogramming through a glucose-fueled histone hyperacetylation pathway. Restoring TXNIP normalizes glucose consumption, lowers PGD catalysis, reverses hyperacetylation, represses malignant transcripts, and impairs metastatic tumorigenesis. We propose that PGD-driven suppression of TXNIP allows pancreatic cancers to avidly consume glucose. This renders PGD constitutively activated and enables metaboloepigenetic selection of additional traits that increase fitness along glucose-replete metastatic routes.


Assuntos
Cromatina/metabolismo , Glucose/metabolismo , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patologia , Animais , Transporte Biológico/genética , Transporte Biológico/fisiologia , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Reprogramação Celular/genética , Reprogramação Celular/fisiologia , Imunoprecipitação da Cromatina , Epigênese Genética/genética , Camundongos , Camundongos Nus , Neoplasias Pancreáticas/genética , Fosfogluconato Desidrogenase/genética , Fosfogluconato Desidrogenase/metabolismo , Tiorredoxinas/genética , Tiorredoxinas/metabolismo
2.
Nat Commun ; 11(1): 4254, 2020 08 26.
Artigo em Inglês | MEDLINE | ID: mdl-32848143

RESUMO

Pulmonary fibrosis (PF) is a major public health problem with limited therapeutic options. There is a clear need to identify novel mediators of PF to develop effective therapeutics. Here we show that an ER protein disulfide isomerase, thioredoxin domain containing 5 (TXNDC5), is highly upregulated in the lung tissues from both patients with idiopathic pulmonary fibrosis and a mouse model of bleomycin (BLM)-induced PF. Global deletion of Txndc5 markedly reduces the extent of PF and preserves lung function in mice following BLM treatment. Mechanistic investigations demonstrate that TXNDC5 promotes fibrogenesis by enhancing TGFß1 signaling through direct binding with and stabilization of TGFBR1 in lung fibroblasts. Moreover, TGFß1 stimulation is shown to upregulate TXNDC5 via ER stress/ATF6-dependent transcriptional control in lung fibroblasts. Inducing fibroblast-specific deletion of Txndc5 mitigates the progression of BLM-induced PF and lung function deterioration. Targeting TXNDC5, therefore, could be a novel therapeutic approach against PF.


Assuntos
Fibrose Pulmonar Idiopática/etiologia , Fibrose Pulmonar Idiopática/metabolismo , Isomerases de Dissulfetos de Proteínas/metabolismo , Fibrose Pulmonar/etiologia , Fibrose Pulmonar/metabolismo , Receptor do Fator de Crescimento Transformador beta Tipo I/metabolismo , Tiorredoxinas/metabolismo , Fator de Crescimento Transformador beta1/metabolismo , Animais , Bleomicina/toxicidade , Modelos Animais de Doenças , Estresse do Retículo Endoplasmático , Deleção de Genes , Humanos , Fibrose Pulmonar Idiopática/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Isomerases de Dissulfetos de Proteínas/genética , Dobramento de Proteína , Estabilidade Proteica , Fibrose Pulmonar/patologia , Receptor do Fator de Crescimento Transformador beta Tipo I/química , Transdução de Sinais , Tiorredoxinas/antagonistas & inibidores , Tiorredoxinas/genética , Regulação para Cima
3.
PLoS Pathog ; 16(7): e1008774, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32716974

RESUMO

S-glutathionylation is an important post-translational modification (PTM) process that targets protein cysteine thiols by the addition of glutathione (GSH). This modification can prevent proteolysis caused by the excessive oxidation of protein cysteine residues under oxidative or nitrosative stress conditions. Recent studies have suggested that protein S-glutathionylation plays an essential role in the control of cell-signaling pathways by affecting the protein function in bacteria and even humans. In this study, we investigated the effects of S-glutathionylation on physiological regulation within Streptococcus mutans, the primary etiological agent of human dental caries. To determine the S-glutathionylated proteins in bacteria, the Cys reactive isobaric reagent iodoacetyl Tandem Mass Tag (iodoTMT) was used to label the S-glutathionylated Cys site, and an anti-TMT antibody-conjugated resin was used to enrich the modified peptides. Proteome profiling identified a total of 357 glutathionylated cysteine residues on 239 proteins. Functional enrichment analysis indicated that these S-glutathionylated proteins were involved in diverse important biological processes, such as pyruvate metabolism and glycolysis. Furthermore, we studied a thioredoxin-like protein (Tlp) to explore the effect of S-glutathionylation on interspecies competition between oral streptococcal biofilms. Through site mutagenesis, it was proved that glutathionylation on Cys41 residue of Tlp is crucial to protect S. mutans from oxidative stress and compete with S. sanguinis and S. gordonii. An addition rat caries model showed that the loss of S-glutathionylation attenuated the cariogenicity of S. mutans. Taken together, our study provides an insight into the S-glutathionylation of bacterial proteins and the regulation of oxidative stress resistance and interspecies competition.


Assuntos
Cárie Dentária/microbiologia , Interações Microbianas/fisiologia , Streptococcus mutans/metabolismo , Streptococcus mutans/patogenicidade , Tiorredoxinas/metabolismo , Animais , Proteínas de Bactérias/metabolismo , Biofilmes , Cárie Dentária/metabolismo , Humanos , Processamento de Proteína Pós-Traducional , Proteoma/metabolismo , Ratos
4.
Proc Natl Acad Sci U S A ; 117(28): 16283-16291, 2020 07 14.
Artigo em Inglês | MEDLINE | ID: mdl-32611810

RESUMO

The difficulty of achieving robust functional expression of insect nicotinic acetylcholine receptors (nAChRs) has hampered our understanding of these important molecular targets of globally deployed neonicotinoid insecticides at a time when concerns have grown regarding the toxicity of this chemotype to insect pollinators. We show that thioredoxin-related transmembrane protein 3 (TMX3) is essential to enable robust expression in Xenopus laevis oocytes of honeybee (Apis mellifera) and bumblebee (Bombus terrestris) as well as fruit fly (Drosophila melanogaster) nAChR heteromers targeted by neonicotinoids and not hitherto robustly expressed. This has enabled the characterization of picomolar target site actions of neonicotinoids, findings important in understanding their toxicity.


Assuntos
Proteínas de Insetos/metabolismo , Inseticidas/farmacologia , Neonicotinoides/farmacologia , Agonistas Nicotínicos/farmacologia , Receptores Nicotínicos/metabolismo , Acetilcolina/farmacologia , Animais , Abelhas/metabolismo , Relação Dose-Resposta a Droga , Drosophila melanogaster/metabolismo , Proteínas de Insetos/agonistas , Proteínas de Insetos/genética , Oócitos/metabolismo , Subunidades Proteicas/antagonistas & inibidores , Subunidades Proteicas/genética , Subunidades Proteicas/metabolismo , Receptores Nicotínicos/genética , Tiorredoxinas/genética , Tiorredoxinas/metabolismo , Xenopus laevis
5.
Arch Biochem Biophys ; 690: 108416, 2020 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-32502471

RESUMO

Alkaptonuria (AKU) is a rare metabolic disease correlated with the deficiency of homogentisate 1,2-dioxygenase and leading to an accumulation of the metabolite homogentisic acid (HGA) which can be subjected to oxidation and polymerization reactions. These events are considered a trigger for the induction of oxidative stress in AKU but, despite the large description of an altered redox status, the underlying pathogenetic processes are still unstudied. In the present study, we investigated the molecular mechanisms responsible for the oxidative damage present in an osteoblast-based cellular model of AKU. Bone, in fact, is largely affected in AKU patients: severe osteoclastic resorption, osteoporosis, even for pediatric cases, and an altered rate of remodeling biomarkers have been reported. In our AKU osteoblast cell model, we found a clear altered redox homeostasis, determined by elevated hydrogen peroxide (H2O2) levels and 4HNE protein adducts formation. These findings were correlated with increased NADPH oxidase (NOX) activity and altered mitochondrial respiration. In addition, we observed a decreased activity of superoxide dismutase (SOD) and reduced levels of thioredoxin (TRX) that parallel the decreased Nrf2-DNA binding. Overall, our results reveal that HGA is able to alter the cellular redox homeostasis by modulating the endogenous ROS production via NOX activation and mitochondrial dysfunctions and impair the cellular response mechanism. These findings can be useful for understanding the pathophysiology of AKU, not yet well studied in bones, but which is an important source of comorbidities that affect the life quality of the patients.


Assuntos
Alcaptonúria/metabolismo , Homeostase/fisiologia , Linhagem Celular , Proteínas de Ligação a DNA/metabolismo , Ácido Homogentísico/metabolismo , Humanos , Peróxido de Hidrogênio/metabolismo , Mitocôndrias/metabolismo , Mitocôndrias/ultraestrutura , NADPH Oxidases/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Osteoblastos/citologia , Oxirredução , Estresse Oxidativo/fisiologia , Transdução de Sinais , Superóxido Dismutase/metabolismo , Tiorredoxinas/metabolismo
6.
Toxicol Appl Pharmacol ; 401: 115079, 2020 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-32497534

RESUMO

Thioredoxin 1 (Trx1) and telomerase play key roles in the development and progression process of most tumors, and they both are promising drug therapy targets. We have, for the first time, discovered that Trx1 and telomerase had a dual-target synergistic effect. Based on that results, we designed a series of 6-dithio-2'-deoxyguanosine analogs (named as YLS00X) and verified whether they can inhibit Trx1 and telomerase simultaneously. TrxR1/Trx1 system activity and telomerase expression were significantly inhibited by 6-dithio-2'-deoxyguanosine analogs, especially YLS004. YLS004 can also cause ROS accumulation, and induce tumor cell apoptosis. The vitro antitumor activity of 6-dithio-2'-deoxyguanosine analogs using MTT assay on 11 different human cancer cells and found that human colon cancer cells(HCT116) and melanoma cells (A375) were the most sensitive cells to 6-dithio-2'-deoxyguanosine analogs treatment and vivo xenografts models also confirmed that. The serum biochemical parameters and multiple organs HE staining results of subacute experiments indicated that YLS004 might be mildly toxic to immune organs, including the thymus, spleen, and hematopoietic system. Besides, YLS004 was rapidly metabolized in the rats' blood. Our study revealed that YLS004, a Trx1 and telomerase inhibitor, has strong anti-tumor effects to colon cancer and melanoma cells and is a promising new candidate drug.


Assuntos
Desoxiguanosina/análogos & derivados , Desoxiguanosina/administração & dosagem , Sistemas de Liberação de Medicamentos/métodos , Espécies Reativas de Oxigênio/agonistas , Telomerase/antagonistas & inibidores , Tiorredoxinas/antagonistas & inibidores , Células A549 , Animais , Antineoplásicos/administração & dosagem , Antineoplásicos/química , Apoptose/efeitos dos fármacos , Apoptose/fisiologia , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/fisiologia , Relação Dose-Resposta a Droga , Células HCT116 , Células HT29 , Células Hep G2 , Humanos , Células K562 , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Ratos , Espécies Reativas de Oxigênio/metabolismo , Telomerase/metabolismo , Tiorredoxinas/metabolismo
7.
PLoS One ; 15(4): e0231114, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32243476

RESUMO

Meiosis and oocyte maturation are tightly regulated processes. The meiosis arrest female 1 (MARF1) gene is essential for meiotic progression in animals; however, its detailed function remains unclear. In this study, we examined the molecular mechanism of dMarf1, a Drosophila homolog of MARF1 encoding an OST and RNA Recognition Motif (RRM) -containing protein for meiotic progression and oocyte maturation. Although oogenesis progressed in females carrying a dMarf1 loss-of-function allele, the dMarf1 mutant oocytes were found to contain arrested meiotic spindles or disrupted microtubule structures, indicating that the transition from meiosis I to II was compromised in these oocytes. The expression of the full-length dMarf1 transgene, but none of the variants lacking the OST and RRM motifs or the 47 conserved C-terminal residues among insect groups, rescued the meiotic defect in dMarf1 mutant oocytes. Our results indicate that these conserved residues are important for dMarf1 function. Immunoprecipitation of Myc-dMarf1 revealed that several mRNAs are bound to dMarf1. Of those, the protein expression of nanos (nos), but not its mRNA, was affected in the absence of dMarf1. In the control, the expression of Nos protein became downregulated during the late stages of oogenesis, while it remained high in dMarf1 mutant oocytes. We propose that dMarf1 translationally represses nos by binding to its mRNA. Furthermore, the downregulation of Nos induces cycB expression, which in turn activates the CycB/Cdk1 complex at the onset of oocyte maturation.


Assuntos
Proteínas de Ciclo Celular/metabolismo , Diferenciação Celular , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/citologia , Drosophila melanogaster/metabolismo , Oócitos/citologia , Oócitos/metabolismo , Proteínas de Ligação a RNA/metabolismo , Motivos de Aminoácidos , Animais , Proteínas de Ciclo Celular/química , Proteínas de Ciclo Celular/genética , Fusão Celular , Sequência Conservada , Ciclina B , Regulação para Baixo , Proteínas de Drosophila/química , Proteínas de Drosophila/genética , Feminino , Regulação da Expressão Gênica , Meiose , Proteínas Mutantes/metabolismo , Mutação/genética , Oogênese , Ovário/metabolismo , Ligação Proteica , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Proteínas de Ligação a RNA/química , Proteínas de Ligação a RNA/genética , Tiorredoxinas/metabolismo
8.
Vet Res ; 51(1): 38, 2020 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-32156317

RESUMO

Rhodococcus equi is an intracellular veterinary pathogen that is becoming resistant to current antibiotherapy. Genes involved in preserving redox homeostasis could be promising targets for the development of novel anti-infectives. Here, we studied the role of an extracellular thioredoxin (Etrx3/REQ_13520) in the resistance to phagocytosis. An etrx3-null mutant strain was unable to survive within macrophages, whereas the complementation with the etrx3 gene restored its intracellular survival rate. In addition, the deletion of etrx3 conferred to R. equi a high susceptibility to sodium hypochlorite. Our results suggest that Etrx3 is essential for the resistance of R. equi to specific oxidative agents.


Assuntos
Infecções por Actinomycetales/veterinária , Proteínas de Bactérias/genética , Macrófagos/microbiologia , Fagocitose , Rhodococcus equi/genética , Tiorredoxinas/genética , Infecções por Actinomycetales/imunologia , Animais , Proteínas de Bactérias/metabolismo , Camundongos , Mutação , Tiorredoxinas/metabolismo
9.
Ecotoxicol Environ Saf ; 193: 110259, 2020 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-32097787

RESUMO

In this paper, the effects of 100 mM NaCl and NaHCO3 stress on reactive oxygen species (ROS) and physiological and proteomic aspects of ROS metabolism in mulberry seedling leaves were studied. The results showed that NaCl stress had little effect on photosynthesis and respiration of mulberry seedling leaves. Superoxide dismutase (SOD) activity and the expression of related proteins in leaves increased by varying degrees, and accumulation of superoxide anion (O2·-) not observed. Under NaHCO3 stress, photosynthesis and respiration were significantly inhibited, while the rate of O2·- production rate and H2O2 content increased. The activity of catalase (CAT) and the expression of CAT (W9RJ43) increased under NaCl stress. In response to NaHCO3 stress, the activity and expression of CAT were significantly decreased, but the ability of H2O2 scavenging of peroxidase (POD) was enhanced. The ascorbic acid-glutathione (AsA-GSH) cycle in mulberry seedling leaves was enhancement in both NaCl and NaHCO3 stress. The expression of 2-Cys peroxiredoxin BAS1 (2-Cys Prx BAS1), together with thioredoxin F (TrxF), thioredoxin O1 (TrxO1), thioredoxin-like protein CITRX (Trx CITRX), and thioredoxin-like protein CDSP32 (Trx CDSP32) were significantly increased under NaCl stress. Under NaHCO3 stress, the expression of the electron donor of ferredoxin-thioredoxin reductase (FTR), together with Trx-related proteins, such as thioredoxin M (TrxM), thioredoxin M4 (TrxM4), thioredoxin X (TrxX), TrxF, and Trx CSDP32 were significantly decreased, suggesting that the thioredoxin-peroxiredoxin (Trx-Prx) pathway's function of scavenging H2O2 of in mulberry seedling leaves was inhibited. Taken together, under NaCl stress, excessive production of O2·- mulberry seedlings leaves was inhibited, and H2O2 was effectively scavenged by CAT, AsA-GSH cycle and Trx-Prx pathway. Under NaHCO3 stress, despite the enhanced functions of POD and AsA-GSH cycle, the scavenging of O2·- by SOD was not effective, and that of H2O2 by CAT and Trx-Prx pathway were inhibited; and in turn, the oxidative damage to mulberry seedling leaves could not be reduced.


Assuntos
Antioxidantes/metabolismo , Morus/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Bicarbonato de Sódio/toxicidade , Cloreto de Sódio/toxicidade , Peróxido de Hidrogênio/metabolismo , Morus/crescimento & desenvolvimento , Morus/metabolismo , Peroxirredoxinas/metabolismo , Fotossíntese/efeitos dos fármacos , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/metabolismo , Proteômica , Plântula/efeitos dos fármacos , Plântula/metabolismo , Tiorredoxinas/metabolismo
10.
Am J Pathol ; 190(5): 994-1005, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32084370

RESUMO

Long-term hyperoxia exposure may cause lung damage with characteristic inflammation. Long noncoding RNA of maternally expressed 3 (MEG3) is up-regulated in lung tissues exposed to hyperoxia; however, the underlying mechanism is unclear. Hyperoxia-induced cells and mouse models were used to study these mechanisms. Molecular assays were used to detect cell viability, cytotoxicity, and expression of miR-18a, MEG3, and inflammatory cytokines. The interaction among MEG3, miR-18a, and thioredoxin-interacting protein (TXNIP) was verified; and pyroptosis-related proteins were analyzed. The in vivo model was established by exposing MEG3 knockdown mice to hyperoxia. Hematoxylin and eosin staining was used to assess pathologic alterations of lung tissues. Hyperoxia suppressed cell viability, induced cell damage, and exacerbated the secretion of IL-1ß and IL-18. Hyperoxia inhibited miR-18a, with increased expression of MEG3, TXNIP, and nonobese diabetic-like receptor family pyrin domain containing 3 (NLRP3). MEG3 aggravated TXNIP expression by binding to miR-18a. Knockdown of MEG3 rescued hyperoxia-induced pyroptosis by up-regulating miR-18a. Furthermore, knockdown of MEG3 inhibited NLRP3 inflammasome activity and caspase-1 signaling by miR-18a. In vivo knockdown of MEG3 and overexpression of miR-18a relieved hyperoxia-induced lung injury via restraining NLRP3 inflammasome-mediated pyroptosis, whereas miR-18a inhibition reversed these effects. In conclusion, knockdown of MEG3 inhibits pyroptosis to alleviate hyperoxia lung injury by suppressing NLRP3 inflammasome and caspase-1 signaling via regulating miR-18a-TXNIP axis.


Assuntos
Proteínas de Transporte/metabolismo , Hiperóxia/metabolismo , Lesão Pulmonar/metabolismo , MicroRNAs/metabolismo , RNA Longo não Codificante/metabolismo , Tiorredoxinas/metabolismo , Animais , Técnicas de Silenciamento de Genes , Hiperóxia/complicações , Inflamassomos/metabolismo , Lesão Pulmonar/etiologia , Camundongos , Piroptose/fisiologia , Transdução de Sinais/fisiologia
11.
Biochim Biophys Acta Mol Basis Dis ; 1866(6): 165716, 2020 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-32061776

RESUMO

Thiosulfate sulfurtransferase (TST, EC 2.8.1.1), also known as Rhodanese, is a mitochondrial enzyme which catalyzes the transfer of sulfur in several molecular pathways. After its initial identification as a cyanide detoxification enzyme, it was found that its functions also include sulfur metabolism, modification of iron­sulfur clusters and the reduction of antioxidants glutathione and thioredoxin. TST deficiency was shown to be strongly related to the pathophysiology of metabolic diseases including diabetes and obesity. This review summarizes research related to the enzymatic properties and functions of TST, to then explore the association between the effects of TST on mitochondria and development of diseases such as diabetes and obesity.


Assuntos
Antioxidantes/metabolismo , Doenças Metabólicas/genética , Enxofre/metabolismo , Tiossulfato Sulfurtransferase/genética , Glutationa/metabolismo , Humanos , Proteínas com Ferro-Enxofre/genética , Doenças Metabólicas/enzimologia , Doenças Metabólicas/patologia , Selênio/metabolismo , Tiorredoxinas/genética , Tiorredoxinas/metabolismo , Tiossulfato Sulfurtransferase/metabolismo
12.
Biochem Biophys Res Commun ; 524(3): 582-588, 2020 04 09.
Artigo em Inglês | MEDLINE | ID: mdl-32029274

RESUMO

Colorectal cancer (CRC) is the third most commonly malignancy worldwide. The incidence of CRC is on the rise and leads to indisputable society burden due to the high cost of cancer treatments. Resistance to oxaliplatin-chemotherapy is the major cause for treatment failure and CRC-related death. In this study, we anticipated that TXNDC9 might demonstrate a protective role in oxaliplatin-resistant CRC cells. TXNDC9 was found significantly upregulated when treated with oxaliplatin. Manipulation of TXNDC9 expression largely affected the oxaliplatin-induced cell death. Moreover, TXNDC9 regulates autophagy and apoptosis in response to oxaliplatin treatment in HT29 cells via the Nrf2 pathway. Taken together, our findings explore the biological role of TXNDC9 in oxaliplatin resistance in CRC cells and may identify a novel therapeutic target to counteract drug resistance to oxaliplatin in CRC.


Assuntos
Adenocarcinoma/patologia , Apoptose , Autofagia , Neoplasias Colorretais/patologia , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Oxaliplatina/farmacologia , Tiorredoxinas/metabolismo , Adenocarcinoma/genética , Apoptose/efeitos dos fármacos , Apoptose/genética , Autofagia/efeitos dos fármacos , Autofagia/genética , Neoplasias Colorretais/genética , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Células HT29 , Humanos , Fator 2 Relacionado a NF-E2/metabolismo , Tiorredoxinas/genética , Regulação para Cima/efeitos dos fármacos
13.
Chemistry ; 26(45): 10175-10184, 2020 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-32097513

RESUMO

The thioredoxin system is highly conserved system found in all living cells and comprises NADPH, thioredoxin, and thioredoxin reductase. This system plays a critical role in preserving a reduced intracellular environment, and its involvement in regulating a wide range of cellular functions makes it especially vital to cellular homeostasis. Its critical role is not limited to healthy cells, it is also involved in cancer development, and is overexpressed in many cancers. This makes the thioredoxin system a promising target for cancer drug development. As such, over the last decade, many inhibitors have been developed that target the thioredoxin system, most of which are small molecules targeting the thioredoxin reductase C-terminal redox center. A few inhibitors of thioredoxin have also been developed. We believe that more efforts should be invested in developing protein/peptide-based inhibitors against both thioredoxin reductase and/or thioredoxin.


Assuntos
Antineoplásicos/farmacologia , NADP/química , Neoplasias/tratamento farmacológico , Tiorredoxina Dissulfeto Redutase/metabolismo , Tiorredoxinas/uso terapêutico , Antineoplásicos/química , Desenvolvimento de Medicamentos , Humanos , Oxirredução , Tiorredoxina Dissulfeto Redutase/química , Tiorredoxinas/metabolismo
14.
Inorg Chem ; 59(5): 2711-2718, 2020 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-32049511

RESUMO

Selenoenzymes, containing a selenocysteine (Sec) residue, fulfill important roles in biology. The mammalian thioredoxin reductase selenoenzymes are key regulators of antioxidant defense and redox signaling and are inhibited by methylmercury species and by the gold-containing drug auranofin. It has been proposed that such inhibition is mediated by metal binding to Sec in the enzyme. However, direct structural observations of these classes of inhibitors binding to selenoenzymes have been few to date. Here we therefore have used extended X-ray absorption fine structure as a direct structural probe to investigate binding to the selenium site in recombinant rat thioredoxin reductase 1 (TrxR1). The results demonstrate for the first time the direct and complete binding of the metal atom of the inhibitors to the selenium atom in TrxR1 for both methylmercury and auranofin, indicating that TrxR1 inhibition indeed can be attributed to such direct metal-selenium binding.


Assuntos
Auranofina/química , Auranofina/farmacologia , Compostos de Metilmercúrio/química , Compostos de Metilmercúrio/farmacologia , Selenocisteína/química , Tiorredoxinas/antagonistas & inibidores , Tiorredoxinas/química , Animais , Sítios de Ligação/efeitos dos fármacos , Ratos , Selenocisteína/metabolismo , Tiorredoxinas/metabolismo
15.
Food Microbiol ; 87: 103389, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31948630

RESUMO

To overcome the deleterious effects of hydrogen peroxide, Lactobacillus plantarum elicits an adaptive response to oxidative stress. In this study, global transcriptomic analysis revealed that L. plantarum CAUH2 expanded its carbon source utilizing profile and enhanced glycolysis to produce more ATP to confront with H2O2 stress. Some antioxidant enzymes including NADH peroxidase, thioredoxin reductase and glutathione peroxidase were 6.11, 36.76 and 6.23-fold up-regulated at transcription level for H2O2 scavenging. Meanwhile, free ferrous iron (Fe2+) was maintained at low concentrations in the cytoplasm, which could limit Fenton reaction and reduce the production of hydroxyl radicals. To repair DNA lesion caused by H2O2, both base excision repair system and recombinational DNA repair pathway were employed by L. plantarum CAUH2. In addition, the expression of methionine sulfoxide reductases and thioredoxin were up-regulated to repair oxidized proteins. It is noteworthy that some transcriptional regulators (Spx, CcpA and MarR1) were predicted to participate in the adaptive response to H2O2 stress, suggesting that L. plantarum CAUH2 utilized a wide array of sensors to monitor oxidative stress and modulated the transcriptional regulation network under H2O2 stress. These findings provide novel insight into the protective mechanisms developed by L. plantarum to cope with oxidative stress.


Assuntos
Proteínas de Bactérias/genética , Peróxido de Hidrogênio/farmacologia , Lactobacillus plantarum/efeitos dos fármacos , Lactobacillus plantarum/genética , Proteínas de Bactérias/metabolismo , Perfilação da Expressão Gênica , Glutationa Peroxidase/genética , Glutationa Peroxidase/metabolismo , Lactobacillus plantarum/enzimologia , Lactobacillus plantarum/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Peroxidases/genética , Peroxidases/metabolismo , Tiorredoxinas/genética , Tiorredoxinas/metabolismo , Transcriptoma/efeitos dos fármacos
16.
PLoS Comput Biol ; 16(1): e1007102, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31951606

RESUMO

Cells contain a thiol redox regulatory network to coordinate metabolic and developmental activities with exogenous and endogenous cues. This network controls the redox state and activity of many target proteins. Electrons are fed into the network from metabolism and reach the target proteins via redox transmitters such as thioredoxin (TRX) and NADPH-dependent thioredoxin reductases (NTR). Electrons are drained from the network by reactive oxygen species (ROS) through thiol peroxidases, e.g., peroxiredoxins (PRX). Mathematical modeling promises access to quantitative understanding of the network function and was implemented by using published kinetic parameters combined with fitting to known biochemical data. Two networks were assembled, namely the ferredoxin (FDX), FDX-dependent TRX reductase (FTR), TRX, fructose-1,6-bisphosphatase (FBPase) pathway with 2-cysteine PRX/ROS as oxidant, and separately the FDX, FDX-dependent NADP reductase (FNR), NADPH, NTRC-pathway for 2-CysPRX reduction. Combining both modules allowed drawing several important conclusions of network performance. The resting H2O2 concentration was estimated to be about 30 nM in the chloroplast stroma. The electron flow to metabolism exceeds that into thiol regulation of FBPase more than 7000-fold under physiological conditions. The electron flow from NTRC to 2-CysPRX is about 5.32-times more efficient than that from TRX-f1 to 2-CysPRX. Under severe stress (30 µM H2O2) the ratio of electron flow to the thiol network relative to metabolism sinks to 1:251 whereas the ratio of e- flow from NTRC to 2-CysPRX and TRX-f1 to 2-CysPRX rises up to 1:67. Thus, the simulation provides clues on experimentally inaccessible parameters and describes the functional state of the chloroplast thiol regulatory network.


Assuntos
Cloroplastos/metabolismo , Redes e Vias Metabólicas/fisiologia , Oxirredução , Espécies Reativas de Oxigênio/metabolismo , Arabidopsis/metabolismo , Arabidopsis/fisiologia , Proteínas de Arabidopsis/metabolismo , Simulação por Computador , Ferredoxinas/metabolismo , Peróxido de Hidrogênio/metabolismo , Proteínas com Ferro-Enxofre/metabolismo , NADP/metabolismo , Oxirredutases/metabolismo , Compostos de Sulfidrila/metabolismo , Tiorredoxinas/metabolismo
17.
Proc Natl Acad Sci U S A ; 117(3): 1321-1329, 2020 01 21.
Artigo em Inglês | MEDLINE | ID: mdl-31896586

RESUMO

Cysteine thiols of many cancer-associated proteins are attractive targets of anticancer agents. Herein, we unequivocally demonstrate a distinct thiol-targeting property of gold(III) mesoporphyrin IX dimethyl ester (AuMesoIX) and its anticancer activities. While the binding of cysteine thiols with metal complexes usually occurs via M-S bond formation, AuMesoIX is unique in that the meso-carbon atom of the porphyrin ring is activated by the gold(III) ion to undergo nucleophilic aromatic substitution with thiols. AuMesoIX was shown to modify reactive cysteine residues and inhibit the activities of anticancer protein targets including thioredoxin, peroxiredoxin, and deubiquitinases. Treatment of cancer cells with AuMesoIX resulted in the formation of gold-bound sulfur-rich protein aggregates, oxidative stress-mediated cytotoxicity, and accumulation of ubiquitinated proteins. Importantly, AuMesoIX exhibited effective antitumor activity in mice. Our study has uncovered a gold(III)-induced ligand scaffold reactivity for thiol targeting that can be exploited for anticancer applications.


Assuntos
Antineoplásicos/química , Cisteína/química , Ouro/química , Mesoporfirinas/química , Animais , Antineoplásicos/farmacocinética , Antineoplásicos/uso terapêutico , Enzimas Desubiquitinantes/química , Enzimas Desubiquitinantes/metabolismo , Células HCT116 , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Neoplasias Experimentais/tratamento farmacológico , Peroxirredoxinas/química , Peroxirredoxinas/metabolismo , Ligação Proteica , Tiorredoxinas/química , Tiorredoxinas/metabolismo , Distribuição Tecidual
18.
mBio ; 11(1)2020 01 28.
Artigo em Inglês | MEDLINE | ID: mdl-31992623

RESUMO

Diverse intracellular pathogens rely on eukaryotic cell surface disulfide reductases to invade host cells. Pharmacologic inhibition of these enzymes is cytotoxic, making it impractical for treatment. Identifying and mechanistically dissecting microbial proteins that co-opt surface reductases could reveal novel targets for disrupting this common infection strategy. Anaplasma phagocytophilum invades neutrophils by an incompletely defined mechanism to cause the potentially fatal disease granulocytic anaplasmosis. The bacterium's adhesin, Asp14, contributes to invasion by virtue of its C terminus engaging an unknown receptor. Yeast-two hybrid analysis identified protein disulfide isomerase (PDI) as an Asp14 binding partner. Coimmunoprecipitation confirmed the interaction and validated it to be Asp14 C terminus dependent. PDI knockdown and antibody-mediated inhibition of PDI reductase activity impaired A. phagocytophilum infection of but not binding to host cells. Infection during PDI inhibition was rescued when the bacterial but not host cell surface disulfide bonds were chemically reduced with tris(2-carboxyethyl)phosphine-HCl (TCEP). TCEP also restored bacterial infectivity in the presence of an Asp14 C terminus blocking antibody that otherwise inhibits infection. A. phagocytophilum failed to productively infect myeloid-specific-PDI conditional-knockout mice, marking the first demonstration of in vivo microbial dependency on PDI for infection. Mutational analyses identified the Asp14 C-terminal residues that are critical for binding PDI. Thus, Asp14 binds and brings PDI proximal to A. phagocytophilum surface disulfide bonds that it reduces, which enables cellular and in vivo infection.IMPORTANCE Anaplasma phagocytophilum infects neutrophils to cause granulocytic anaplasmosis, an emerging potentially fatal disease and the second-most common tick-borne illness in the United States. Treatment options are limited, and no vaccine exists. Due to the bacterium's obligatory intracellular lifestyle, A. phagocytophilum survival and pathogenesis are predicated on its ability to enter host cells. Understanding its invasion mechanism will yield new targets for preventing bacterial entry and, hence, disease. We report a novel entry pathway in which the A. phagocytophilum outer membrane protein Asp14 binds host cell surface protein disulfide isomerase via specific C-terminal residues to promote reduction of bacterial surface disulfide bonds, which is critical for cellular invasion and productive infection in vivo Targeting the Asp14 C terminus could be used to prevent/treat granulocytic anaplasmosis. Our findings have broad implications, as a thematically similar approach could be applied to block infection by other intracellular microbes that exploit cell surface reductases.


Assuntos
Adesinas Bacterianas/metabolismo , Anaplasma phagocytophilum/fisiologia , Ehrlichiose/metabolismo , Ehrlichiose/microbiologia , Interações Hospedeiro-Patógeno , Isomerases de Dissulfetos de Proteínas/metabolismo , Adesinas Bacterianas/química , Animais , Modelos Animais de Doenças , Ativação Enzimática , Humanos , Camundongos , Ligação Proteica , Domínios e Motivos de Interação entre Proteínas , Tiorredoxinas/metabolismo
19.
Int J Mol Sci ; 21(2)2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31952224

RESUMO

Neuroindole melatonin, a hormone synthesized during the night mainly-but not exclusively-by the pineal gland of all vertebrates, functions as an adapting signal to the light-dark cycle. Its antioxidant, neuroprotective, anti-inflammatory, and antitumor properties are all well-known and widely reported. Melanoma is one of the most common carcinomas among developed countries and a type of tumor particularly difficult to fight back in medium/advanced stages. In contrast to other types of cancer, influence of melatonin on melanoma has been scarcely investigated. Thus, we have chosen the murine melanoma model B16-F10 cell line to study antiproliferative and antitumoral actions of melatonin. For this purpose, we combined both, cell culture and in vivo models. Melatonin reduced either, growth rate or migration of B16-F10 cells. Furthermore, melanin synthesis was altered by melatonin, promoting its synthesis. Melatonin also induced a G2/M cell cycle arrest and altered the cytoskeletal organization. To corroborate these results, we tested the effect of melatonin in the in vivo model of B16-F10 cell injection in the tail vein, which causes numerous lung metastases. Two different strategies of melatonin administration were used, namely, in drinking water, or daily intraperitoneal injection. However, contrary to what occurred in cell culture, no differences were observed between control and melatonin treated groups. Results obtained led us to conclude that melatonin exerts an antiproliferative and anti-migrating effect on this melanoma model by interfering with the cytoskeleton organization, but this pharmacological effect cannot be translated in vivo as the indole did not prevent metastasis in the murine model, suggesting that further insights into the effects of the indole in melanoma cells should be approached to understand this apparent paradox.


Assuntos
Proliferação de Células/efeitos dos fármacos , Citoesqueleto/efeitos dos fármacos , Melanoma Experimental/metabolismo , Melatonina/farmacologia , Actinas/genética , Actinas/metabolismo , Animais , Antioxidantes/administração & dosagem , Antioxidantes/farmacologia , Catalase/metabolismo , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Citoesqueleto/genética , Citoesqueleto/metabolismo , Pontos de Checagem da Fase G2 do Ciclo Celular/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/secundário , Melaninas/metabolismo , Melanoma Experimental/genética , Melanoma Experimental/patologia , Melatonina/administração & dosagem , Camundongos Endogâmicos C57BL , Superóxido Dismutase/metabolismo , Tiorredoxinas/metabolismo , Tubulina (Proteína)/genética , Tubulina (Proteína)/metabolismo
20.
J Virol ; 94(7)2020 03 17.
Artigo em Inglês | MEDLINE | ID: mdl-31915282

RESUMO

The virus-induced signaling adaptor (VISA) complex plays a critical role in the innate immune response to RNA viruses. However, the mechanism of VISA complex formation remains unclear. Here, we demonstrate that thioredoxin 2 (TRX2) interacts with VISA at mitochondria both in vivo and in vitro Knockdown and knockout of TRX2 enhanced the formation of the VISA-associated complex, as well as virus-triggered activation of interferon regulatory factor 3 (IRF3) and transcription of the interferon beta 1 (IFNB1) gene. TRX2 inhibits the formation of VISA aggregates by repressing reactive oxygen species (ROS) production, thereby disrupting the assembly of the VISA complex. Furthermore, our data suggest that the C93 residue of TRX2 is essential for inhibition of VISA aggregation, whereas the C283 residue of VISA is required for VISA aggregation. Collectively, these findings uncover a novel mechanism of TRX2 that negatively regulates VISA complex formation.IMPORTANCE The VISA-associated complex plays pivotal roles in inducing type I interferons (IFNs) and eliciting the innate antiviral response. Many host proteins are identified as VISA-associated-complex proteins, but how VISA complex formation is regulated by host proteins remains enigmatic. We identified the TRX2 protein as an important regulator of VISA complex formation. Knockout of TRX2 increases virus- or poly(I·C)-triggered induction of type I IFNs at the VISA level. Mechanistically, TRX2 inhibits the production of ROS at its C93 site, which impairs VISA aggregates at its C283 site, and subsequently impedes the assembly of the VISA complex. Our findings suggest that TRX2 plays an important role in the regulation of VISA complex assembly.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Regulação Viral da Expressão Gênica , Imunidade Inata , Proteínas Mitocondriais/metabolismo , Infecções por Respirovirus/imunologia , Vírus Sendai/imunologia , Tiorredoxinas/metabolismo , Células HEK293 , Células HeLa , Humanos , Fator Regulador 3 de Interferon/metabolismo , Interferon beta-1a/metabolismo , Poli I-C/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais , Células THP-1
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA