Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.409
Filtrar
1.
Int J Mol Sci ; 22(16)2021 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-34445751

RESUMO

Sarcopenia, the age-related decline in muscle mass and function, derives from multiple etiological mechanisms. Accumulative research suggests that reactive oxygen species (ROS) generation plays a critical role in the development of this pathophysiological disorder. In this communication, we review the various signaling pathways that control muscle metabolic and functional integrity such as protein turnover, cell death and regeneration, inflammation, organismic damage, and metabolic functions. Although no single pathway can be identified as the most crucial factor that causes sarcopenia, age-associated dysregulation of redox signaling appears to underlie many deteriorations at physiological, subcellular, and molecular levels. Furthermore, discord of mitochondrial homeostasis with aging affects most observed problems and requires our attention. The search for the primary suspect of the fundamental mechanism for sarcopenia will likely take more intense research for the secret of this health hazard to the elderly to be unlocked.


Assuntos
Proteínas Musculares/metabolismo , Estresse Oxidativo , Sarcopenia/etiologia , Sarcopenia/metabolismo , Transdução de Sinais , Proteínas Quinases Ativadas por AMP/metabolismo , Animais , Apoptose , Homeostase , Humanos , Inflamação/metabolismo , Mitocôndrias/metabolismo , NAD/metabolismo , Junção Neuromuscular/metabolismo , Oxirredução , Peroxirredoxinas/metabolismo , Regeneração
2.
J Virol ; 95(19): e0092321, 2021 09 09.
Artigo em Inglês | MEDLINE | ID: mdl-34260286

RESUMO

Peroxiredoxin 1 (PRDX1) is a cellular antioxidant enzyme that is crucial for diverse fundamental biological processes, such as autophagy, inflammation, and carcinogenesis. However, molecular mechanisms underpinning its diverse roles are not well understood. Here, we report that PRDX1 positively regulates interferon (IFN) induction and that pseudorabies virus (PRV) targets PRDX1 to evade IFN induction. PRV UL13 encodes a serine/threonine kinase important for PRV infection, although its biological function remains obscure. We identified PRDX1 as a UL13-interacting protein. Virological and biochemical assays demonstrate that PRDX1 promotes IFN induction by interacting with TANK-binding kinase 1 (TBK1) and IκB kinase ε (IKKε). Conversely, UL13 accelerates PRDX1 degradation via the ubiquitin-proteosome pathway in a kinase-dependent manner. In doing so, PRV inhibits IFN induction during productive infection, which requires PRDX1 expression. This study uncovers an essential role of PRDX1 in the innate immune response and reveals a new viral immune evasion strategy to counteract cellular defenses. IMPORTANCE PRV interacts with numerous cellular proteins during productive infection. Here, we demonstrated the interaction of viral protein UL13 with the antioxidant enzyme PRDX1, which functions in multiple signal transduction pathways. We found that PRDX1 participates in the type I IFN pathway by interacting with TBK1 and IKKε, thereby negatively regulating PRV propagation. However, UL13 ubiquitinates PRDX1, which routes PRDX1 into proteasomes for degradation and effectively reduces its expression. These results illuminate the fundamental role that PRDX1 plays in the IFN pathway, and they identify a potential target for the control of PRV infection.


Assuntos
Herpesvirus Suídeo 1/fisiologia , Quinase I-kappa B/metabolismo , Imunidade Inata , Peroxirredoxinas/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Virais/metabolismo , Animais , Linhagem Celular , Células HEK293 , Herpesvirus Suídeo 1/imunologia , Humanos , Evasão da Resposta Imune , Interferon Tipo I/biossíntese , Mutação , Complexo de Endopeptidases do Proteassoma/metabolismo , Transdução de Sinais , Ubiquitinação , Proteínas Virais/genética , Replicação Viral
3.
Int J Mol Sci ; 22(11)2021 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-34199590

RESUMO

In living cells Reactive Oxygen Species (ROS) participate in intra- and inter-cellular signaling and all cells contain specific systems that guard redox homeostasis. These systems contain both enzymes which may produce ROS such as NADPH-dependent and other oxidases or nitric oxide synthases, and ROS-neutralizing enzymes such as catalase, peroxiredoxins, thioredoxins, thioredoxin reductases, glutathione reductases, and many others. Most of the genes coding for these enzymes contain sequences targeted by micro RNAs (miRNAs), which are components of RNA-induced silencing complexes and play important roles in inhibiting translation of their targeted messenger RNAs (mRNAs). In this review we describe miRNAs that directly target and can influence enzymes responsible for scavenging of ROS and their possible role in cellular redox homeostasis. Regulation of antioxidant enzymes aims to adjust cells to survive in unstable oxidative environments; however, sometimes seemingly paradoxical phenomena appear where oxidative stress induces an increase in the levels of miRNAs which target genes which are supposed to neutralize ROS and therefore would be expected to decrease antioxidant levels. Here we show examples of such cellular behaviors and discuss the possible roles of miRNAs in redox regulatory circuits and further cell responses to stress.


Assuntos
Antioxidantes/metabolismo , Homeostase/genética , MicroRNAs/genética , Estresse Oxidativo/genética , Glutationa Redutase/genética , Glutationa Redutase/metabolismo , Humanos , Óxido Nítrico Sintase/genética , Óxido Nítrico Sintase/metabolismo , Oxirredução , Peroxirredoxinas/genética , Peroxirredoxinas/metabolismo , Tiorredoxinas/genética , Tiorredoxinas/metabolismo
4.
Appl Microbiol Biotechnol ; 105(14-15): 5701-5717, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34258640

RESUMO

The oxidative and nitrosative responses generated by animals and plants are important defenses against infection and establishment of pathogenic microorganisms such as bacteria, fungi, and protozoa. Among distinct oxidant species, hydroperoxides are a group of chemically diverse compounds that comprise small hydrophilic molecules, such as hydrogen peroxide and peroxynitrite, and bulky hydrophobic species, such as organic hydroperoxides. Peroxiredoxins (Prx) are ubiquitous enzymes that use a highly reactive cysteine residue to decompose hydroperoxides and can also perform other functions, like molecular chaperone and phospholipase activities, contributing to microbial protection against the host defenses. Prx are present in distinct cell compartments and, in some cases, they can be secreted to the extracellular environment. Despite their high abundance, Prx expression can be further increased in response to oxidative stress promoted by host defense systems, by treatment with hydroperoxides or by antibiotics. In consequence, some isoforms have been described as virulence factors, highlighting their importance in pathogenesis. Prx are very diverse and are classified into six different classes (Prx1-AhpC, BCP-PrxQ, Tpx, Prx5, Prx6, and AhpE) based on structural and biochemical features. Some groups are absent in hosts, while others present structural peculiarities that differentiate them from the host's isoforms. In this context, the intrinsic characteristics of these enzymes may aid the development of new drugs to combat pathogenic microorganisms. Additionally, since some isoforms are also found in the extracellular environment, Prx emerge as attractive targets for the production of diagnostic tests and vaccines. KEY POINTS: • Peroxiredoxins are front-line defenses against host oxidative and nitrosative stress. • Functional and structural peculiarities differ pathogen and host enzymes. • Peroxiredoxins are potential targets to microbicidal drugs.


Assuntos
Peróxido de Hidrogênio , Peroxirredoxinas , Animais , Oxirredução , Estresse Oxidativo , Peroxirredoxinas/genética , Peroxirredoxinas/metabolismo , Plantas/metabolismo
5.
J Biol Chem ; 297(1): 100866, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34118234

RESUMO

Genetically encoded fluorescent H2O2 probes continue to advance the field of redox biology. Here, we compare the previously established peroxiredoxin-based H2O2 probe roGFP2-Tsa2ΔCR with the newly described OxyR-based H2O2 probe HyPer7, using yeast as the model system. Although not as sensitive as roGFP2-Tsa2ΔCR, HyPer7 is much improved relative to earlier HyPer versions, most notably by ratiometric pH stability. The most striking difference between the two probes is the dynamics of intracellular probe reduction. HyPer7 is rapidly reduced, predominantly by the thioredoxin system, whereas roGFP2-Tsa2ΔCR is reduced more slowly, predominantly by the glutathione system. We discuss the pros and cons of each probe and suggest that future side-by-side measurements with both probes may provide information on the relative activity of the two major cellular reducing systems.


Assuntos
Técnicas Biossensoriais/métodos , Proteínas de Escherichia coli/metabolismo , Peróxido de Hidrogênio/análise , Peroxirredoxinas/metabolismo , Proteínas Repressoras/metabolismo , Técnicas Biossensoriais/normas , Proteínas de Escherichia coli/genética , Genes Reporter , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Peróxido de Hidrogênio/metabolismo , Peroxidases/genética , Peroxidases/metabolismo , Peroxirredoxinas/genética , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Proteínas Repressoras/genética , Saccharomyces cerevisiae , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo
6.
Braz J Med Biol Res ; 54(9): e10931, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34076143

RESUMO

Tobacco can induce reactive oxygen species (ROS) production extensively in cells, which is a major risk factor for oral leukoplakia (OLK) development. Peroxiredoxin 1 (Prx1) is a key antioxidant protein, upregulated in a variety of malignant tumors. We previously found that nicotine, the main ingredient of tobacco, promotes oral carcinogenesis via regulating Prx1. The aim of the present study was to screen and identify the Prx1 interacting proteins and investigate the mechanisms of nicotine on the development of OLK. Through liquid chromatography-tandem mass spectrometry combined with bioinformatics analysis, the candidate Prx1 interacting proteins of cofilin-1 (CFL1), tropomyosin alpha-3 chain (TPM3), and serine/threonine-protein phosphatase 2A 65 kDa regulatory subunit A alpha isoform (PPP2R1A) were screened in human dysplastic oral keratinocyte cells treated with nicotine. CFL1, TPM3, and PPP2R1A were highly expressed in human OLK tissues. The expression of CFL1 increased and the expression of PPP2R1A decreased in OLK of smokers compared to that in OLK of non-smokers. Nicotine upregulated CFL1 and downregulated PPP2R1A in 4-nitro-quinoline-1-oxide (4NQO)-induced OLK tissues in mice in part dependent on Prx1. Furthermore, the in-situ interaction of CFL1, TPM3, and PPP2R1A with Prx1 were validated in human OLK tissues. Our results suggested that tobacco might promote the development of OLK via regulating Prx1 and its interacting proteins CFL1 and PPP2R1A.


Assuntos
Leucoplasia Oral , Nicotina , Peroxirredoxinas , Animais , Carcinogênese , Proteínas de Transporte , Proteínas de Homeodomínio , Leucoplasia Oral/induzido quimicamente , Camundongos , Peroxirredoxinas/metabolismo
7.
Nat Commun ; 12(1): 3720, 2021 06 17.
Artigo em Inglês | MEDLINE | ID: mdl-34140524

RESUMO

Low levels of reactive oxygen species (ROS) are crucial for maintaining cancer stem cells (CSCs) and their ability to resist therapy, but the ROS regulatory mechanisms in CSCs remains to be explored. Here, we discover that prohibitin (PHB) specifically regulates mitochondrial ROS production in glioma stem-like cells (GSCs) and facilitates GSC radiotherapeutic resistance. We find that PHB is upregulated in GSCs and is associated with malignant gliomas progression and poor prognosis. PHB binds to peroxiredoxin3 (PRDX3), a mitochondrion-specific peroxidase, and stabilizes PRDX3 protein through the ubiquitin-proteasome pathway. Knockout of PHB dramatically elevates ROS levels, thereby inhibiting GSC self-renewal. Importantly, deletion or pharmacological inhibition of PHB potently slows tumor growth and sensitizes tumors to radiotherapy, thus providing significant survival benefits in GSC-derived orthotopic tumors and glioblastoma patient-derived xenografts. These results reveal a selective role of PHB in mitochondrial ROS regulation in GSCs and suggest that targeting PHB improves radiotherapeutic efficacy in glioblastoma.


Assuntos
Neoplasias Encefálicas/metabolismo , Glioblastoma/metabolismo , Células-Tronco Neoplásicas/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Proteínas Repressoras/metabolismo , Adulto , Idoso , Animais , Astrocitoma/metabolismo , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patologia , Linhagem Celular Tumoral , Progressão da Doença , Resistencia a Medicamentos Antineoplásicos , Feminino , Regulação Neoplásica da Expressão Gênica/genética , Técnicas de Inativação de Genes , Glioblastoma/genética , Glioblastoma/patologia , Glioblastoma/radioterapia , Humanos , Masculino , Camundongos , Pessoa de Meia-Idade , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Gradação de Tumores , Peroxirredoxinas/metabolismo , Prognóstico , Complexo de Endopeptidases do Proteassoma/metabolismo , Proteínas Repressoras/antagonistas & inibidores , Proteínas Repressoras/genética , Análise Serial de Tecidos , Ensaios Antitumorais Modelo de Xenoenxerto
8.
Aging (Albany NY) ; 13(10): 13926-13940, 2021 05 24.
Artigo em Inglês | MEDLINE | ID: mdl-34030134

RESUMO

Peroxiredoxin II (Prx II) is involved in proliferation, differentiation, and aging in various cell types. However, Prx II-mediated stem cell regulation is poorly understood. Here, dermal mesenchymal stem cells (DMSCs), cell-growth factor-rich conditioned medium from DMSCs (DMSC-CM), and DMSC-derived exosomes (DMSC-Exos) were used to explore the regulatory role of Prx II in DMSC wound healing. Following treatment, wound healing was significantly decelerated in Prx II-/- DMSCs than in Prx II+/+ DMSCs. In vitro stimulation with 10 µM H2O2 significantly increased apoptosis in Prx II-/- DMSCs compared with Prx II+/+ DMSCs. The mRNA expression levels of EGF, b-FGF, PDGF-B, and VEGF did not significantly differ between Prx II-/- and Prx II+/+ DMSCs. Fibroblasts proliferated comparably when treated with Prx II+/+ DMSC-CM or Prx II-/- DMSC-CM. Wound healing was significantly higher in the Prx II-/- DMSC-Exos-treated group than in the Prx II+/+ DMSCs-Exos-treated group. Moreover, microRNA (miR)-21-5p expression levels were lower and miR-221 levels were higher in Prx II-/- DMSCs than in Prx II+/+ DMSCs. Therefore, our results indicate that Prx II accelerated wound healing by protecting DMSCs from reactive oxygen species-induced apoptosis; however, Prx II did not regulate cell/growth factor secretion. Prx II potentially regulates exosome functions via miR-21-5p and miR-221.


Assuntos
Derme/citologia , Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais/citologia , Peroxirredoxinas/metabolismo , Cicatrização , Animais , Apoptose , Meios de Cultivo Condicionados/farmacologia , Exossomos/efeitos dos fármacos , Exossomos/metabolismo , Exossomos/ultraestrutura , Deleção de Genes , Peróxido de Hidrogênio/toxicidade , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Células-Tronco Mesenquimais/metabolismo , Camundongos Knockout , MicroRNAs/genética , MicroRNAs/metabolismo , Estresse Oxidativo/efeitos dos fármacos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Cicatrização/genética
9.
Genes (Basel) ; 12(5)2021 04 29.
Artigo em Inglês | MEDLINE | ID: mdl-33946853

RESUMO

The human pathogenic fungus Aspergillus fumigatus is readily eradicated by the innate immunity of immunocompetent human hosts, but can cause severe infections, such as invasive aspergillosis (IA), in immunocompromised individuals. During infection, the fungal redox homeostasis can be challenged by reactive oxygen species (ROS), either derived from the oxidative burst of innate immune cells or the action of antifungal drugs. The peroxiredoxin Asp f3 was found to be essential to cause IA in mice, but how Asp f3 integrates with fungal redox homeostasis remains unknown. Here, we show that in vivo, Asp f3 acts as a sensor for ROS. While global transcription in fungal hyphae under minimal growth conditions was fully independent of Asp f3, a robust induction of the oxidative stress response required the presence of the peroxiredoxin. Hyphae devoid of Asp f3 failed to activate several redox active genes, like members of the gliotoxin biosynthesis gene cluster and integral members of the Afyap1 regulon, the central activator of the ROS defense machinery in fungi. Upon deletion of the asp f3 gene Afyap1 displayed significantly reduced nuclear localization during ROS exposure, indicating that Asp f3 can act as an intracellular redox sensor for several target proteins.


Assuntos
Aspergillus fumigatus/metabolismo , Proteínas Fúngicas/metabolismo , Estresse Oxidativo , Peroxirredoxinas/metabolismo , Transdução de Sinais , Aspergillus fumigatus/genética , Proteínas Fúngicas/genética , Peroxirredoxinas/genética , Espécies Reativas de Oxigênio/metabolismo , Transcriptoma
10.
Biomed Pharmacother ; 139: 111673, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33965729

RESUMO

Zingiber roseum is native to Bangladesh and widely used in folk medicine. This present study was designed to assess the ameliorative potential of Zingiber roseum rhizome extract in carbon tetrachloride (CCl4) induced hepatotoxicity in mice model. Seven phenolic compounds were identified and quantified by HPLC analysis in the plant extract, including quercetin, myricetin, catechin hydrate, trans-ferulic acid, trans-cinnamic acid, (-) epicatechin, and rosmarinic acid. Hepatotoxicity was induced by administrating a single intraperitoneal injection of CCl4 (10 mL/kg) on 7th day of treatment. The results revealed that plant extract at all doses (100, 200 and 400 mg/kg) significantly reduced (p < 0.05) the elevated serum aspartate aminotransferase (AST), alanine aminotransferase (ALT) and alkaline phosphatase (ALP) concentrations, and these effects were comparable to that of standard drug silymarin. Histopathological examination also revealed the evidence of recovery from CCL4 induced cellular damage when pretreated with Z. roseum rhizome extract. The in-vivo hepatoprotective effects were further investigated by the in-silico study of the aforementioned compounds with liver-protective enzymes such as superoxide dismutase (SOD), peroxiredoxin, and catalase. The strong binding affinities (ranging from -7.3359 to -9.111 KCal/mol) between the phenolic compounds (except trans-cinnamic acid) and oxidative stress enzymes inhibit ROS production during metabolism. The compounds were also found non-toxic in computational prediction, and a series of biological activities like antioxidant, anticarcinogen, cardio-protectant, hepato-protectant have been detected.


Assuntos
Intoxicação por Tetracloreto de Carbono/prevenção & controle , Doença Hepática Induzida por Substâncias e Drogas/prevenção & controle , Polifenóis/química , Polifenóis/farmacologia , Rizoma/química , Zingiberaceae/química , Animais , Intoxicação por Tetracloreto de Carbono/patologia , Catalase/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/enzimologia , Doença Hepática Induzida por Substâncias e Drogas/patologia , Cromatografia Líquida de Alta Pressão , Feminino , Fígado/enzimologia , Fígado/patologia , Testes de Função Hepática , Camundongos , Simulação de Acoplamento Molecular , Estresse Oxidativo/efeitos dos fármacos , Peroxirredoxinas/metabolismo , Extratos Vegetais/farmacologia , Substâncias Protetoras/farmacologia , Espécies Reativas de Oxigênio , Silimarina/uso terapêutico , Superóxido Dismutase/metabolismo
11.
J Biol Chem ; 296: 100665, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33895140

RESUMO

Peroxiredoxins (PRDXs) catalyze the reduction of hydrogen peroxide (H2O2). PRDX4 is the only peroxiredoxin located within the endoplasmic reticulum (ER) and is the most highly expressed H2O2 scavenger in the ER. PRDX4 has emerged as an important player in numerous diseases, such as fibrosis and metabolic syndromes, and its overoxidation is a potential indicator of ER redox stress. It is unclear how overoxidation of PRDX4 governs its oligomerization state and interacting partners. Herein, we addressed these questions via nonreducing Western blots, mass spectrometry, and site-directed mutagenesis. We report that the oxidation of PRDX4 in lung epithelial cells treated with tertbutyl hydroperoxide caused a shift of PRDX4 from monomer/dimer to high molecular weight (HMW) species, which contain PRDX4 modified with sulfonic acid residues (PRDX4-SO3), as well as of a complement of ER-associated proteins, including protein disulfide isomerases important in protein folding, thioredoxin domain-containing protein 5, and heat shock protein A5, a key regulator of the ER stress response. Mutation of any of the four cysteines in PRDX4 altered the HMW species in response to tertbutyl hydroperoxide as well as the secretion of PRDX4. We also demonstrate that the expression of ER oxidoreductase 1 alpha, which generates H2O2 in the ER, increased PRDX4 HMW formation and secretion. These results suggest a link between SO3 modification in the formation of HMW PRDX4 complexes in cells, whereas the association of key regulators of ER homeostasis with HMW oxidized PRDX4 point to a putative role of PRDX4 in regulating ER stress responses.


Assuntos
Estresse do Retículo Endoplasmático , Retículo Endoplasmático/metabolismo , Células Epiteliais/metabolismo , Pulmão/metabolismo , Peroxirredoxinas/química , Peroxirredoxinas/metabolismo , Dobramento de Proteína , Animais , Camundongos , Domínios e Motivos de Interação entre Proteínas , Multimerização Proteica
12.
Aging (Albany NY) ; 13(8): 11170-11187, 2021 03 26.
Artigo em Inglês | MEDLINE | ID: mdl-33819194

RESUMO

Colon cancer stem cells (CCSCs) play an important role in facilitating colon cancer occurrence, metastasis and drug resistance. The results of our previous studies confirmed that the well-studied antioxidant gene peroxiredoxin-2 (PRDX2) promotes colon cancer progression. However, the underlying function and mechanisms associated with PRDX2 remodeling in the context of CCSCs have remained poorly studied. In our present study, we demonstrated that PRDX2 is highly expressed in CD133/CD44-positive colon cancer tissues and spheroid CD133+CD44+ CCSCs. PRDX2 overexpression was shown to be closely correlated with CD133+CD44+ CCSCs in colon cancer. Furthermore, PRDX2 depletion markedly suppressed CD133+CD44+ CCSC stemness maintenance, tumor initiation, migration and invasion and liver metastasis. Furthermore, the expression of various EMT markers and Wnt/ß-catenin signaling proteins was altered after PRDX2 inhibition. In addition, PRDX2 knockdown led to increased ROS production in CD133+CD44+ CCSCs, sensitizing CCSCs to oxidative stress and chemotherapy. These results suggest that PRDX2 could be a possible therapeutic target in CCSCs.


Assuntos
Neoplasias do Colo/patologia , Neoplasias Hepáticas/genética , Células-Tronco Neoplásicas/patologia , Peroxirredoxinas/metabolismo , Animais , Colo/patologia , Neoplasias do Colo/genética , Feminino , Regulação Neoplásica da Expressão Gênica , Técnicas de Silenciamento de Genes , Células HCT116 , Células HT29 , Humanos , Neoplasias Hepáticas/secundário , Camundongos , Peroxirredoxinas/genética , Esferoides Celulares , Ensaios Antitumorais Modelo de Xenoenxerto
13.
Redox Biol ; 42: 101959, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33895094

RESUMO

Peroxiredoxins (Prdxs) sense and assess peroxide levels, and signal through protein interactions. Understanding the role of the multiple structural and post-translational modification (PTM) layers that tunes the peroxiredoxin specificities is still a challenge. In this review, we give a tabulated overview on what is known about human and bacterial peroxiredoxins with a focus on structure, PTMs, and protein-protein interactions. Armed with numerous cellular and atomic level experimental techniques, we look at the future and ask ourselves what is still needed to give us a clearer view on the cellular operating power of Prdxs in both stress and non-stress conditions.


Assuntos
Peróxidos , Peroxirredoxinas , Humanos , Peróxido de Hidrogênio , Oxirredução , Peroxirredoxinas/metabolismo , Personalidade , Transdução de Sinais
14.
Anticancer Res ; 41(4): 1831-1840, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33813388

RESUMO

BACKGROUND/AIM: Peroxiredoxin V (Prx V) plays crucial roles in cellular apoptosis and proliferation in various cancer cells by regulating the cellular reactive oxygen species (ROS) levels. MATERIALS AND METHODS: Here, we examined the possible regulatory effects of Prx V on doxorubicin (DOX)-induced cellular apoptosis and its mechanisms in the human gastric adenocarcinoma cell line (AGS cells). RESULTS: Our findings suggest that Prx V knockdown may significantly increase the DOX-induced apoptosis by aggravating intracellular ROS accumulation. We also found that DOX-induced mitochondrial ROS levels and membrane permeability were significantly higher in short hairpin Prx V cells than in mock cells, and these phenomena were dramatically reversed by ROS scavenger treatment. Prx V knockdown also significantly upregulated the cleaved caspase 9, 3, and B-cell lymphoma 2 (Bcl2)-associated agonist of cell death/Bcl2 protein expression levels, suggesting that Prx V knockdown activates mitochondria-dependent apoptotic signaling pathways. CONCLUSION: Taken together, this study suggests that Prx V may be a strong molecular target for gastric cancer (GC) chemotherapy, and further elucidates the role of Prx V in oxidative stress-induced cell apoptosis.


Assuntos
Adenocarcinoma/tratamento farmacológico , Antibióticos Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Doxorrubicina/farmacologia , Inativação Gênica , Mitocôndrias/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Peroxirredoxinas/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Neoplasias Gástricas/tratamento farmacológico , Adenocarcinoma/enzimologia , Adenocarcinoma/genética , Adenocarcinoma/patologia , Proteínas Reguladoras de Apoptose/metabolismo , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica , Humanos , Mitocôndrias/enzimologia , Mitocôndrias/patologia , Peroxirredoxinas/genética , Transdução de Sinais , Neoplasias Gástricas/enzimologia , Neoplasias Gástricas/genética , Neoplasias Gástricas/patologia
15.
Redox Biol ; 43: 101980, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33905956

RESUMO

Intravenous infusion of high dose (>10 g) vitamin C (IVC) is a common alternative cancer therapy. IVC results in millimolar levels of circulating ascorbate, which is proposed to generate cytotoxic quantities of H2O2 in the presence of transition metal ions. In this study we report on the in vitro and in vivo effects of millimolar ascorbate on erythrocytes. Addition of ascorbate to whole blood increased erythrocyte intracellular ascorbate approximately 35-fold. Within 10 min of ascorbate addition, we detected increased oxidation of erythrocyte peroxiredoxin 2 (Prx2), a major thiol antioxidant protein and a sensitive marker of H2O2 production. Up to 50% of Prx2 was present in the oxidised form after 60 min. The presence of extracellular catalase, removal of plasma or the addition of a metal chelator did not prevent ascorbate-induced Prx2 oxidation, suggesting that the H2O2 responsible for Prx2 oxidation was generated within the erythrocyte. Ascorbate is known to increase the rate of haemoglobin autoxidation and H2O2 production. Through spectral monitoring of oxidised haemoglobin we estimated a generation rate of 15 µM H2O2/min inside erythrocytes. We also investigated changes in erythrocyte ascorbate concentration and Prx2 oxidation following IVC infusion in a cohort of patients with cancer. Plasma ascorbate levels ranged from 7.8 to 35 mM immediately post infusion, while erythrocyte ascorbate levels reached 1.5-3.4 mM 4 h after beginning infusion. Transient oxidation of erythrocyte Prx2 was observed. We conclude that erythrocytes accumulate ascorbate during IVC infusion, providing a significant reservoir of ascorbate, and this ascorbate increases H2O2 generation within the cells. The consequence of increased erythrocyte Prx2 oxidation warrants further investigation.


Assuntos
Peróxido de Hidrogênio , Peroxirredoxinas , Ácido Ascórbico , Eritrócitos/metabolismo , Proteínas de Homeodomínio , Humanos , Oxirredução , Peroxirredoxinas/metabolismo
16.
Exp Mol Pathol ; 120: 104641, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33901418

RESUMO

Several mechanisms have been suggested to explain the adverse effects of air pollutants on airway cells. One such explanation is the presence of high concentrations of oxidants and pro-oxidants in environmental pollutants. All animal and plant cells have developed several mechanisms to prevent damage by oxidative molecules. Among these, the peroxiredoxins (PRDXs) are of interest due to a high reactivity with reactive oxygen species (ROS) through the functioning of the thioredoxin/thioredoxin reductase system. This study aimed to verify the gene expression patterns of the PRDX family in bronchial epithelial airway cells (BEAS-2B) cells exposed to diesel exhaust particles (DEPs) at a concentration of 15 µg/mL for 1 or 2 h because this it is a major component of particulate matter in the atmosphere. There was a significant decrease in mRNA fold changes of PRDX2 (0.43 ± 0.34; *p = 0.0220), PRDX5 (0.43 ± 0.34; *p = 0.0220), and PRDX6 (0.33 ± 0.25; *p = 0.0069) after 1 h of exposure to DEPs. The reduction in mRNA levels may consequently lead to a decrease in the levels of PRDX proteins, increasing oxidative stress in bronchial epithelial cells BEAS-2B and thus, negatively affecting cellular functions.


Assuntos
Brônquios/metabolismo , Células Epiteliais/metabolismo , Regulação da Expressão Gênica , Material Particulado/efeitos adversos , Peroxirredoxinas/metabolismo , Emissões de Veículos/análise , Brônquios/efeitos dos fármacos , Brônquios/patologia , Células Cultivadas , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/patologia , Humanos , Peroxirredoxinas/genética
17.
J Biol Chem ; 296: 100494, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33667550

RESUMO

Peroxiredoxin 2 (Prdx2) is a thiol peroxidase with an active site Cys (C52) that reacts rapidly with H2O2 and other peroxides. The sulfenic acid product condenses with the resolving Cys (C172) to form a disulfide which is recycled by thioredoxin or GSH via mixed disulfide intermediates or undergoes hyperoxidation to the sulfinic acid. C172 lies near the C terminus, outside the active site. It is not established whether structural changes in this region, such as mixed disulfide formation, affect H2O2 reactivity. To investigate, we designed mutants to cause minimal (C172S) or substantial (C172D and C172W) structural disruption. Stopped flow kinetics and mass spectrometry showed that mutation to Ser had minimal effect on rates of oxidation and hyperoxidation, whereas Asp and Trp decreased both by ∼100-fold. To relate to structural changes, we solved the crystal structures of reduced WT and C172S Prdx2. The WT structure is highly similar to that of the published hyperoxidized form. C172S is closely related but more flexible and as demonstrated by size exclusion chromatography and analytical ultracentrifugation, a weaker decamer. Size exclusion chromatography and analytical ultracentrifugation showed that the C172D and C172W mutants are also weaker decamers than WT, and small-angle X-ray scattering analysis indicated greater flexibility with partially unstructured regions consistent with C-terminal unfolding. We propose that these structural changes around C172 negatively impact the active site geometry to decrease reactivity with H2O2. This is relevant for Prdx turnover as intermediate mixed disulfides with C172 would also be disruptive and could potentially react with peroxides before resolution is complete.


Assuntos
Cisteína/química , Cisteína/metabolismo , Peróxido de Hidrogênio/metabolismo , Peroxirredoxinas/química , Peroxirredoxinas/metabolismo , Sequência de Aminoácidos , Domínio Catalítico , Cristalografia por Raios X , Humanos , Peróxido de Hidrogênio/química , Mutação , Oxidantes/química , Oxidantes/metabolismo , Oxirredução , Relação Estrutura-Atividade
18.
Cell Death Dis ; 12(3): 265, 2021 03 12.
Artigo em Inglês | MEDLINE | ID: mdl-33712558

RESUMO

NOXA, a BH3-only proapoptotic protein involved in regulating cell death decisions, is highly expressed but short-lived in colorectal cancer (CRC). Neddylated cullin-5 (CUL5)-mediated ubiquitination and degradation of NOXA is crucial to prevent its overaccumulation and maintain an appropriate action time. However, how this process is manipulated by CRC cells commonly exposed to oxidative stress remain unknown. The peroxiredoxin PRDX1, a conceivable antioxidant overexpressed in CRC tissues, has been shown to inhibit apoptosis and TRAF6 ubiquitin-ligase activity. In this study, we found that PRDX1 inhibits CRC cell apoptosis by downregulating NOXA. Mechanistically, PRDX1 promotes NOXA ubiquitination and degradation, which completely depend on CUL5 neddylation. Further studies have demonstrated that PRDX1 oligomers bind with both the Nedd8-conjugating enzyme UBE2F and CUL5 and that this tricomplex is critical for CUL5 neddylation, since silencing PRDX1 or inhibiting PRDX1 oligomerization greatly dampens CUL5 neddylation and NOXA degradation. An increase in reactive oxygen species (ROS) is not only a hallmark of cancer cells but also the leading driving force for PRDX1 oligomerization. As shown in our study, although ROS play a role in upregulating NOXA mRNA transcription, ROS scavenging in CRC cells by N-acetyl-L-cysteine (NAC) can significantly reduce CUL5 neddylation and extend the NOXA protein half-life. Therefore, in CRC, PRDX1 plays a key role in maintaining intracellular homeostasis under conditions of high metabolic activity by reinforcing UBE2F-CUL5-mediated degradation of NOXA, which is also evidenced in the resistance of CRC cells to etoposide treatment. Based on these findings, targeting PRDX1 could be an effective strategy to overcome the resistance of CRC to DNA damage-inducing chemotherapeutics.


Assuntos
Neoplasias Colorretais/enzimologia , Proteínas Culina/metabolismo , Peroxirredoxinas/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Apoptose , Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Proteínas Culina/genética , Regulação Neoplásica da Expressão Gênica , Células HCT116 , Células HEK293 , Células HT29 , Meia-Vida , Humanos , Peroxirredoxinas/genética , Multimerização Proteica , Proteólise , Proteínas Proto-Oncogênicas c-bcl-2/genética , Espécies Reativas de Oxigênio/metabolismo , Enzimas de Conjugação de Ubiquitina/genética , Enzimas de Conjugação de Ubiquitina/metabolismo , Ubiquitinação
19.
Biochemistry (Mosc) ; 86(1): 84-91, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33705284

RESUMO

2-Cys peroxiredoxins are abundant thiol proteins that react efficiently with a wide range of peroxides. Unlike other enzymes, their exceptionally high reactivity does not rely on cofactors. The mechanism of oxidation and reduction of peroxiredoxins places them in a good position to act as antioxidants as well as key players in redox signaling. Understanding of the intimate details of peroxiredoxin functioning is important for translational research.


Assuntos
Peroxirredoxinas/metabolismo , Animais , Humanos , Oxirredução , Transdução de Sinais
20.
Mol Immunol ; 133: 184-193, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33744653

RESUMO

Natural killer enhancing factor (NKEF)-A/B is a member of Peroxiredoxin (Prxs) family, which is named for the function of enhancing NK cells activity. NKEF also plays essential roles in multiple physiology/pathology processes including inflammation regulation, cancer development and redox reactions. However, the regulatory effects of fish NKEF on immune cells remain largely unknown. In this study, the full-length cDNA of NKEF-A (Accession No. MK584553, designated as On-NKEF-A) was identified from Nile tilapia (Oreochromis niloticus). On-NKEF-A encoded a 198 amino acid peptide with molecular mass of 22.085 kDa. On-NKEF-A protein contained a typical 2-Cys family domain, two active sites (51aa and 172aa) that were conserved in mammals, birds, amphibians and fish. Phylogenetic analysis showed that On-NKEF-A had the closest relationship with Zebra mbuna (Maylandia zebra) NKEF. The On-NKEF-A transcription was present in all examined tissues or organs. And the relative high expression levels of On-NKEF-A was found in head kidney leucocytes and nonspecific cytotoxic cells (NCC). After Streptococcus agalactiae stimulation, On-NKEF-A was significantly up-regulated in head kidney, spleen, gill and skin. Also, On-NKEF-A was markedly induced post S. agalactiae, LPS and poly I:C stimulation in head kidney-derived NCC. Moreover, On-NKEF-A was mainly distributed in cytoplasm of fathead minnow cells (FHM cells). The further in vitro analysis found that the recombinant protein of On-NKEF-A (rOn-NKEF-A) could induce the expression of various molecular markers of B cells, macrophages and NCC, enhanced the cytotoxicity of NCC via increasing the effectors expression. The present data collectively indicate that On-NKEF-A participates in anti-bacterial immune response via regulating NCC activity, which will provide new ideas to further explore the defense mechanism of fish against bacteria.


Assuntos
Ciclídeos/imunologia , Proteínas de Peixes/metabolismo , Células Matadoras Naturais/imunologia , Peroxirredoxinas/metabolismo , Streptococcus agalactiae/imunologia , Sequência de Aminoácidos , Animais , Ciclídeos/microbiologia , Doenças dos Peixes/imunologia , Doenças dos Peixes/microbiologia , Proteínas de Peixes/genética , Proteínas de Peixes/farmacocinética , Brânquias/metabolismo , Rim Cefálico/metabolismo , Imunidade Inata/genética , Imunidade Inata/imunologia , Peroxirredoxinas/genética , Peroxirredoxinas/farmacocinética , Domínios Proteicos/genética , Pele/metabolismo , Baço/metabolismo , Infecções Estreptocócicas/imunologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...