Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 815
Filtrar
1.
Zhonghua Nan Ke Xue ; 26(2): 99-105, 2020 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-33346410

RESUMO

Objective: To explore the protective effect of Peroxiredoxin 4 (PRDX4) on the testes undergoing heat stress in PRDX4 knockout mice. METHODS: Twenty-four C57BL/6 mice underwent CRISPR/Cas9-mediated total knockout of the PRDX4 gene and another 24 wild-type mice were used as controls. At 9 weeks of age, the rats were subjected to 15-minute testicular heat stress in 43℃ water once a day for 3 days, or in 25℃ water as the control. Before and at 1 day and 5 weeks after treatment, 4 from each group were sacrificed respectively and their testes harvested for observation of histological changes by HE staining, detection of the apoptosis of spermatogenic cells by TUNEL and determination of the expression of PRDX4 by Western blot and those of the oxidative stress factors hydroxynonenal (HNE) and 8-OHdG by immunohistochemistry. RESULTS: No statistically significant differences were observed in testicular histology, the apoptosis rate of spermatogenic cells, and the expressions of HNE and 8-OHdG between the PRDX4 knockout mice and wild-type controls (P > 0.05). After 1-day 43℃ heat stress, the PRDX4 knockout mice showed a significantly increased apoptosis rate of spermatogenic cells as compared with the baseline (ï¼»38.65 ± 2.57ï¼½% vs ï¼»0.46 ± 0.06ï¼½%, P < 0.01), and so did the wild-type controls (ï¼»13.21 ± 1.43ï¼½% vs ï¼»0.33 ± 0.01ï¼½%, P < 0.01), higher in the PRDX4 knockout than in the wild-type control group even at 5 weeks after heat stress (ï¼»3.09 ± 0.16ï¼½% vs ï¼»1.45 ± 0.11ï¼½%, P < 0.01). The PRDX4 knockout mice also exhibited a markedly upregulated expression of 8-OHdG (38.25 ± 1.19 vs 19.54 ± 1.13, P < 0.01), and so did the wild-type controls (24.30 ± 1.65 vs 18.22 ± 1.18, P < 0.01), higher in the PRDX4 knockout than in the wild-type control group even at 5 weeks after heat stress (25.40 ± 1.57 vs 23.25 ± 1.48, P < 0.01). The expression of HNE, however, showed no statistically significant difference before and at 1 day after 43℃ heat stress either in the PRDX4 knockout mice or in the wild-type controls (P > 0.05), though remarkably higher in the former than in the latter group at 5 weeks after treatment (28.57 ± 0.56 vs 19.00 ± 1.35, P < 0.01). The expression of 8-OHdG was also higher in the PRDX4 knockout than in the wild-type control group at 5 weeks, but with no statistically significant difference (P > 0.05). CONCLUSIONS: PRDX4 can effectively protect the testis from heat stress and promote the restoration of its spermatogenic function.


Assuntos
Resposta ao Choque Térmico , Estresse Oxidativo , Peroxirredoxinas/genética , Testículo , Animais , Apoptose , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Testículo/metabolismo
2.
PLoS One ; 15(12): e0242465, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33332365

RESUMO

Peroxiredoxin 2 (PRDX2) is upregulated in various cancers including oral squamous cell carcinoma (OSCC). It is a known tumor promoter in some cancers, but its role in OSCC is unclear. This study aimed to investigate the effect of arecoline, an alkaloid of the betel nut, and human papillomavirus type 16 (HPV16) E6/E7 oncoproteins on induction of PRDX2 expression, and also the effects of PRDX2 overexpression in oral cell lines. Levels of PRDX2 protein were determined using western blot analysis of samples of exfoliated normal oral cells (n = 75) and oral lesion cells from OSCC cases (n = 75). Some OSCC cases were positive for HPV infection and some patients had a history of betel quid chewing. To explore the level of PRDX2 by western blot, the proteins were extracted from oral cell lines that were treated with arecoline or retroviruses containing HPV16 E6 gene and HPV16 E6/E7 expressing vector. For analysis of PRDX2 functions, cell proliferation, cell-cycle progression, apoptosis and migration was compared between oral cells overexpressing PRDX2 and cells with PRDX2-knockdown. PRDX2 expression levels tended to be higher in OSCC samples that were positive for HPV infection and had history of betel quid chewing. Arecoline treatment in vitro at low concentrations and overexpression of HPV16 E6 or E6/E7 in oral cells induced PRDX2 overexpression. Interestingly, in oral cells, PRDX2 promoted cell proliferation, cell-cycle progression (G2/M phase), cell migration and inhibited apoptosis. Upregulation of PRDX2 in oral cells was induced by arecoline and HPV16 oncoproteins and promoted growth of OSCC cells.


Assuntos
Arecolina/farmacologia , Carcinoma de Células Escamosas/genética , Regulação Neoplásica da Expressão Gênica , Neoplasias Bucais/genética , Proteínas Oncogênicas Virais/genética , Proteínas E7 de Papillomavirus/genética , Peroxirredoxinas/genética , Proteínas Repressoras/genética , Idoso , Apoptose/genética , Carcinoma de Células Escamosas/enzimologia , Carcinoma de Células Escamosas/patologia , Estudos de Casos e Controles , Ciclo Celular/efeitos dos fármacos , Ciclo Celular/genética , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Feminino , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Papillomavirus Humano 16/química , Papillomavirus Humano 16/genética , Papillomavirus Humano 16/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias Bucais/enzimologia , Neoplasias Bucais/patologia , Proteínas Oncogênicas Virais/metabolismo , Proteínas E7 de Papillomavirus/metabolismo , Peroxirredoxinas/antagonistas & inibidores , Peroxirredoxinas/metabolismo , Plasmídeos/química , Plasmídeos/metabolismo , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Proteínas Repressoras/metabolismo , Transdução de Sinais , Transfecção
3.
BMC Infect Dis ; 20(1): 694, 2020 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-32962648

RESUMO

BACKGROUND: Toxoplasma gondii infection endangers human health and affects animal husbandry. Serological detection is the main method used for epidemiological investigations and diagnosis of toxoplasmosis. The key to effective diagnosis of toxoplasmosis is the use of a standardized antigen and a specific and sensitive detection method. Peroxiredoxin is an antigenic protein and vaccine candidate antigen of T. gondii that has not yet been exploited for diagnostic application. METHODS: In this study, recombinant T. gondii peroxiredoxin protein (rTgPrx) was prepared and used in dot-immunogold-silver staining (Dot-IGSS) to detect IgG antibodies in serum from mice and pregnant women. The rTgPrx-Dot-IGSS method was established and optimized using mouse serum. Furthermore, serum samples from pregnant women were analyzed by rTgPrx-Dot-IGSS. RESULTS: Forty serum samples from mice infected with T. gondii and twenty negative serum samples were analyzed. The sensitivity and specificity of rTgPrx-Dot-IGSS were 97.5 and 100%, respectively, equivalent to those of a commercial ELISA kit for anti-Toxoplasma IgG antibody. Furthermore, 540 serum samples from pregnant women were screened with a commercial ELISA kit. Eighty-three positive and 60 negative serum samples were analyzed by rTgPrx-Dot-IGSS. The positive rate was 95.18%, comparable to that obtained with the commercial ELISA kit. CONCLUSIONS: The Dot-IGSS method with rTgPrx as an antigen might be useful for diagnosing T. gondii infection in individuals.


Assuntos
Imuno-Histoquímica/métodos , Peroxirredoxinas/imunologia , Complicações Parasitárias na Gravidez , Toxoplasmose/diagnóstico , Animais , Ensaio de Imunoadsorção Enzimática/métodos , Feminino , Humanos , Camundongos , Peroxirredoxinas/genética , Gravidez , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Sensibilidade e Especificidade , Coloração pela Prata , Toxoplasma/imunologia , Toxoplasma/patogenicidade , Toxoplasmose/parasitologia
4.
Proc Natl Acad Sci U S A ; 117(40): 24947-24956, 2020 10 06.
Artigo em Inglês | MEDLINE | ID: mdl-32968016

RESUMO

The acquisition of mutations plays critical roles in adaptation, evolution, senescence, and tumorigenesis. Massive genome sequencing has allowed extraction of specific features of many mutational landscapes but it remains difficult to retrospectively determine the mechanistic origin(s), selective forces, and trajectories of transient or persistent mutations and genome rearrangements. Here, we conducted a prospective reciprocal approach to inactivate 13 single or multiple evolutionary conserved genes involved in distinct genome maintenance processes and characterize de novo mutations in 274 diploid Saccharomyces cerevisiae mutation accumulation lines. This approach revealed the diversity, complexity, and ultimate uniqueness of mutational landscapes, differently composed of base substitutions, small insertions/deletions (InDels), structural variants, and/or ploidy variations. Several landscapes parallel the repertoire of mutational signatures in human cancers while others are either novel or composites of subsignatures resulting from distinct DNA damage lesions. Notably, the increase of base substitutions in the homologous recombination-deficient Rad51 mutant, specifically dependent on the Polζ translesion polymerase, yields COSMIC signature 3 observed in BRCA1/BRCA2-mutant breast cancer tumors. Furthermore, "mutome" analyses in highly polymorphic diploids and single-cell bottleneck lineages revealed a diverse spectrum of loss-of-heterozygosity (LOH) signatures characterized by interstitial and terminal chromosomal events resulting from interhomolog mitotic cross-overs. Following the appearance of heterozygous mutations, the strong stimulation of LOHs in the rad27/FEN1 and tsa1/PRDX1 backgrounds leads to fixation of homozygous mutations or their loss along the lineage. Overall, these mutomes and their trajectories provide a mechanistic framework to understand the origin and dynamics of genome variations that accumulate during clonal evolution.


Assuntos
Neoplasias da Mama/genética , Carcinogênese/genética , Mutação/genética , Saccharomyces cerevisiae/genética , Acetiltransferases/genética , Proteína BRCA1/genética , Proteína BRCA2/genética , Neoplasias da Mama/patologia , Dano ao DNA/genética , DNA Polimerase Dirigida por DNA , Diploide , Feminino , Endonucleases Flap/genética , Genoma Fúngico/genética , Humanos , Perda de Heterozigosidade/genética , Proteínas de Membrana/genética , Peroxirredoxinas/genética , Rad51 Recombinase/genética , Proteínas de Saccharomyces cerevisiae/genética , Sequenciamento Completo do Genoma
5.
Mol Immunol ; 126: 73-86, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32771671

RESUMO

Natural killer enhancing factor (NKEF) of peroxiredoxin family is an important innate immune molecule with having anti-oxidant activity. Although this gene has already been studied in a few fish species, it is yet to be identified and functionally characterised in Indian major carps. In the present study, the complete NKEF-B cDNA of rohu, Labeo rohita was cloned that encoded a putative protein of 197 amino acids. The phylogenetic study showed that L. rohita NKEF-B (LrNKEF-B) is closely related to NKEF-B of Cyprinus carpio and Danio rerio species. Tissue-specific expression of LrNKEF-B gene revealed the highest transcript level in the liver tissue. In the ontogeny study, the highest level of the expression was observed in milt and at 18 h post-development. The expression pattern of this gene was also studied in various pathogen models viz., Gram-negative bacteria (Aeromonas hydrophila), ectoparasite (Argulus siamensis) and a dsRNA viral analogue (poly I:C) in the liver and anterior kidney tissues of L. rohita juveniles. During A. hydrophila infection, the increase in expression of transcripts was observed at 3 h post-infection in both liver (15-fold) and anterior kidney (8-fold). In A. siamensis infection, the expression gradually increased up to 3 d post-infection in the anterior kidney, whereas in liver 3-fold up-regulation was noticed at 12 h post-infection. Similarly, during poly I:C stimulation, up-regulation of NKEF-B transcript was observed in anterior kidney from 1 h to 24 h post-stimulation and down-regulated afterwards whereas, the transcript level increased gradually from 6 h to 15 d post-stimulation in liver tissue. In vitro exposure to concanavalin, A and formalin-killed A. hydrophila upregulated NKEF-B gene expression in anterior kidney and peripheral blood leukocytes of L. rohita, however, down-regulated the same in the splenic leukocytes. A recombinant protein of LrNKEF-B (rLrNKEF-B) of 22 kDa was produced and it showed anti-oxidant activity by protecting supercoiled DNA and reducing insulin disulfide bonds. The minimum bactericidal concentration of this recombinant protein was found to be 4.54 µM against A. hydrophila and Staphylococcus aureus. Interestingly, rLrNKEF-B showed relative percent survival of 72.6 % in A. hydrophila challenged L. rohita, and the survival was found to be associated with a high level of expression of different cytokines, anti-oxidant genes and perforin in the rLrNKEF-B treated L. rohita. An indirect ELISA assay for estimation of NKEF was developed in L. rohita, and the concentrations of NKEF-B increased with time periods post A. hydrophila challenge viz., 0 h (42.56 ng/mL), 12 h (174 ng/mL) and 48 h (370 ng/mL) in rohu serum. Our results suggest a crucial role of LrNKEF-B in innate immunity against biotic stress and oxidative damage and also having antibacterial activity.


Assuntos
Carpas/imunologia , Doenças dos Peixes/imunologia , Proteínas de Peixes/imunologia , Imunidade Inata , Peroxirredoxinas/imunologia , Aeromonas hydrophila/imunologia , Animais , Arguloida/imunologia , Carpas/genética , Carpas/microbiologia , Carpas/parasitologia , Clonagem Molecular , Doenças dos Peixes/sangue , Doenças dos Peixes/microbiologia , Doenças dos Peixes/parasitologia , Proteínas de Peixes/genética , Proteínas de Peixes/metabolismo , Perfilação da Expressão Gênica , Rim Cefálico/enzimologia , Rim Cefálico/imunologia , Fígado/enzimologia , Fígado/imunologia , Estresse Oxidativo/imunologia , Peroxirredoxinas/genética , Filogenia , Poli I-C/imunologia , Espécies Reativas de Oxigênio/imunologia , Espécies Reativas de Oxigênio/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Proteínas Recombinantes/metabolismo , Staphylococcus aureus/imunologia
6.
Anticancer Res ; 40(8): 4491-4504, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32727779

RESUMO

BACKGROUND: Peroxiredoxin II (PRDX2) performs unique roles in cells. It can reduce peroxides through cysteine residues, and helps prevent the effects of oxidative stress on cells. It is closely related to the occurrence and development of various diseases, especially alcoholic liver injury and even liver cancer. The metabolism of alcohol in hepatocytes leads to the increase in the levels of reactive oxygen species (ROS), oxidative stress, injury, and apoptosis. Therefore, this study focused on the investigating the protection conferred by PRDX2 against alcohol-induced apoptosis of hepatocytes. MATERIALS AND METHODS: PRDX2 inhibition of alcohol-induced apoptosis in L02 hepatocytes was analyzed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, fluorescence microscopy, flow cytometry, western blotting and hematoxylin and eosin staining. RESULTS: The results showed that the levels of reactive oxygen species, protein kinase B, ß-catenin, B-cell lymphoma-2 (BCL2), BCL-XL, BCL2-associated X, cleaved caspase-3, and cleaved poly (ADP-ribose) polymerase in PRDX2-silenced cells were increased significantly after the treatment of cells with ethanol. Similar results were obtained in an in vivo Prdx2-knockout mouse model of alcoholic liver injury. Therefore, PRDX2 may regulate the phosphorylation of the AKT signal protein by eliminating reactive oxygen species from cells, and it inhibits the downstream mitochondria-dependent apoptosis pathway, and, thereby, the apoptosis of cells. CONCLUSION: Thus, PRDX2 may be a potential molecular target for the prevention and treatment of alcoholic liver injury.


Assuntos
Etanol/efeitos adversos , Hepatócitos/citologia , Peroxirredoxinas/genética , Transdução de Sinais , Apoptose , Linhagem Celular , Regulação da Expressão Gênica/efeitos dos fármacos , Inativação Gênica , Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Humanos , Fosforilação/efeitos dos fármacos , Poli(ADP-Ribose) Polimerases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais/efeitos dos fármacos , beta Catenina/metabolismo
7.
Proc Natl Acad Sci U S A ; 117(28): 16313-16323, 2020 07 14.
Artigo em Inglês | MEDLINE | ID: mdl-32601209

RESUMO

Peroxiredoxins are central to cellular redox homeostasis and signaling. They serve as peroxide scavengers, sensors, signal transducers, and chaperones, depending on conditions and context. Typical 2-Cys peroxiredoxins are known to switch between different oligomeric states, depending on redox state, pH, posttranslational modifications, and other factors. Quaternary states and their changes are closely connected to peroxiredoxin activity and function but so far have been studied, almost exclusively, outside the context of the living cell. Here we introduce the use of homo-FRET (Förster resonance energy transfer between identical fluorophores) fluorescence polarization to monitor dynamic changes in peroxiredoxin quaternary structure inside the crowded environment of living cells. Using the approach, we confirm peroxide- and thioredoxin-related quaternary transitions to take place in cellulo and observe that the relationship between dimer-decamer transitions and intersubunit disulfide bond formation is more complex than previously thought. Furthermore, we demonstrate the use of the approach to compare different peroxiredoxin isoforms and to identify mutations and small molecules affecting the oligomeric state inside cells. Mutagenesis experiments reveal that the dimer-decamer equilibrium is delicately balanced and can be shifted by single-atom structural changes. We show how to use this insight to improve the design of peroxiredoxin-based redox biosensors.


Assuntos
Peroxirredoxinas/química , Linhagem Celular , Transferência Ressonante de Energia de Fluorescência , Proteínas de Homeodomínio/química , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Humanos , Peróxido de Hidrogênio/metabolismo , Peróxido de Hidrogênio/farmacologia , Proteínas Luminescentes/química , Proteínas Luminescentes/genética , Proteínas Luminescentes/metabolismo , Mutação , Peroxirredoxinas/genética , Peroxirredoxinas/metabolismo , Multimerização Proteica/efeitos dos fármacos , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo
8.
Harmful Algae ; 94: 101808, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32414504

RESUMO

Chattonella spp. are known to produce large amounts of reactive oxygen species (ROS); however, little is known about the mechanisms involved in mitigating the intracellular accumulation of ROS. In this study, a time-series of biological responses in C. marina var. antiqua under different oxidative stress conditions, induced by adding H2O2 at the initial concentrations of 100 and 500 µM, was investigated. Although the added exogenous H2O2 was rapidly consumed at 3 h post-exposure (hpe), intracellular ROS levels were enhanced in the 500 µM H2O2 group but decreased in the 100 µM H2O2 group. Accompanied by increased intracellular ROS levels, the photosynthetic activity of C. marina var. antiqua was considerably inhibited in the 500 µM H2O2 group, but not in the 100 µM H2O2 group. The Fv/Fm ratio and PIABS were negatively correlated with the intracellular ROS level, while the ABS/RC, TR0/RC, and DI0/RC were positively correlated with the intracellular ROS level. Expression of the gene encoding 2-cysteine peroxiredoxin (2-Cys Prx) was up-regulated in 100 µM H2O2 group at 6 hpe, but was down-regulated in 100 µM H2O2 group at 3 and 6 hpe. A negative relationship between the 2-Cys Prx transcript levels and intracellular ROS levels was detected. Results of the 2-DE proteomic analysis confirmed that the 500 µM H2O2 treatment down-regulated the expression of 2-Cys Prx and induced more damage to photosynthetic abilities of C. marina var. antiqua.


Assuntos
Cisteína , Peroxirredoxinas , Cisteína/metabolismo , Peróxido de Hidrogênio , Estresse Oxidativo , Peroxirredoxinas/genética , Peroxirredoxinas/metabolismo , Proteômica
9.
Mol Carcinog ; 59(6): 661-669, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32339330

RESUMO

Gastrointestinal stromal tumor (GIST) is a common mesenchymal tumor in the gastrointestinal tract. Prostate cancer associated transcript 6 (PCAT6) is a long noncoding RNA (lncRNA) and plays a pivotal role in tumor formation. Present study was designed to explore the function of PCAT6 in GIST. Ki67 staining, colony formation and trypan blue staining assays revealed that PCAT6 boosted GIST cell proliferation but inhibited cell apoptosis. Also, sphere formation assay and Western blot uncovered the promoting role of PCAT6 in GIST stemness. Then, we identified that PCAT6 could activate Wnt/ß-catenin pathway. And the tumor facilitator role of Wnt/ß-catenin pathway was validated in the rescue assays. Next, miR-143-3p was identified as the downstream microRNA of PCAT6. Moreover, miR-143-3p itself served as a tumor suppressor in GIST. Subsequently, peroxiredoxin 5 (PRDX5) was verified as the target of miR-143-3p. PCAT6 promoted GIST cell proliferation and stemness via sponging miR-143-3p to upregulate PRDX5. In a word, PCAT6 promoted GIST cell proliferation and stemness but inhibited cell apoptosis via competing endogenous RNA pattern and activation of Wnt pathway, which might contribute to GIST treatment.


Assuntos
Neoplasias Gastrointestinais/patologia , Tumores do Estroma Gastrointestinal/patologia , Regulação Neoplásica da Expressão Gênica , MicroRNAs/genética , Peroxirredoxinas/metabolismo , RNA Longo não Codificante/genética , Via de Sinalização Wnt , Apoptose , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Proliferação de Células , Neoplasias Gastrointestinais/genética , Neoplasias Gastrointestinais/metabolismo , Tumores do Estroma Gastrointestinal/genética , Tumores do Estroma Gastrointestinal/metabolismo , Humanos , Células-Tronco Neoplásicas/metabolismo , Células-Tronco Neoplásicas/patologia , Peroxirredoxinas/genética , Prognóstico , Ativação Transcricional , Células Tumorais Cultivadas , beta Catenina/genética , beta Catenina/metabolismo
10.
Nat Commun ; 11(1): 1666, 2020 04 03.
Artigo em Inglês | MEDLINE | ID: mdl-32245970

RESUMO

Cyanobacteria are model organisms for photosynthesis and are attractive for biotechnology applications. To aid investigation of genotype-phenotype relationships in cyanobacteria, we develop an inducible CRISPRi gene repression library in Synechocystis sp. PCC 6803, where we aim to target all genes for repression. We track the growth of all library members in multiple conditions and estimate gene fitness. The library reveals several clones with increased growth rates, and these have a common upregulation of genes related to cyclic electron flow. We challenge the library with 0.1 M L-lactate and find that repression of peroxiredoxin bcp2 increases growth rate by 49%. Transforming the library into an L-lactate-secreting Synechocystis strain and sorting top lactate producers enriches clones with sgRNAs targeting nutrient assimilation, central carbon metabolism, and cyclic electron flow. In many examples, productivity can be enhanced by repression of essential genes, which are difficult to access by transposon insertion.


Assuntos
Proteínas de Bactérias/genética , Regulação Bacteriana da Expressão Gênica , Peroxirredoxinas/genética , Fotobiorreatores/microbiologia , Synechocystis/genética , Proteínas de Bactérias/metabolismo , Sistemas CRISPR-Cas/genética , Ácido Láctico/metabolismo , Peroxirredoxinas/metabolismo , Synechocystis/metabolismo
11.
Am J Physiol Regul Integr Comp Physiol ; 318(5): R1004-R1013, 2020 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-32292063

RESUMO

Both reactive nitrogen and oxygen species (RNS and ROS), such as nitric oxide, peroxynitrite, and hydrogen peroxide, have been implicated as mediators of pancreatic ß-cell damage during the pathogenesis of autoimmune diabetes. While ß-cells are thought to be vulnerable to oxidative damage due to reportedly low levels of antioxidant enzymes, such as catalase and glutathione peroxidase, we have shown that they use thioredoxin reductase to detoxify hydrogen peroxide. Thioredoxin reductase is an enzyme that participates in the peroxiredoxin antioxidant cycle. Peroxiredoxins are expressed in ß-cells and, when overexpressed, protect against oxidative stress, but the endogenous roles of peroxiredoxins in the protection of ß-cells from oxidative damage are unclear. Here, using either glucose oxidase or menadione to continuously deliver hydrogen peroxide, or the combination of dipropylenetriamine NONOate and menadione to continuously deliver peroxynitrite, we tested the hypothesis that ß-cells use peroxiredoxins to detoxify both of these reactive species. Either pharmacological peroxiredoxin inhibition with conoidin A or specific depletion of cytoplasmic peroxiredoxin 1 (Prdx1) using siRNAs sensitizes INS 832/13 cells and rat islets to DNA damage and death induced by hydrogen peroxide or peroxynitrite. Interestingly, depletion of peroxiredoxin 2 (Prdx2) had no effect. Together, these results suggest that ß-cells use cytoplasmic Prdx1 as a primary defense mechanism against both ROS and RNS.


Assuntos
Dano ao DNA , Peróxido de Hidrogênio/toxicidade , Células Secretoras de Insulina/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Peroxirredoxinas/metabolismo , Ácido Peroxinitroso/toxicidade , Animais , Morte Celular , Linhagem Celular Tumoral , Citoplasma/enzimologia , Citoproteção , Inibidores Enzimáticos/farmacologia , Células Secretoras de Insulina/enzimologia , Células Secretoras de Insulina/patologia , Masculino , Peroxirredoxinas/antagonistas & inibidores , Peroxirredoxinas/genética , Quinoxalinas/farmacologia , Interferência de RNA , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Ratos Sprague-Dawley , Transdução de Sinais , Tiorredoxina Redutase 1/metabolismo
12.
Mol Cell Biochem ; 468(1-2): 97-109, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32185676

RESUMO

Obesity was originally considered a disease endemic to developed countries but has since emerged as a global health problem. Obesity is characterized by abnormal or excessive lipid accumulation (World Health Organization, WHO) resulting from pre-adipocyte differentiation (adipogenesis). The endoplasmic reticulum (ER) produces proteins and cholesterol and shuttles these compounds to their target sites. Many studies have implicated ER stress, indicative of ER dysfunction, in adipogenesis. Reactive oxygen species (ROS) are also known to be involved in pre-adipocyte differentiation. Prx4 specific to the ER lumen exhibits ROS scavenging activity, and we thereby focused on ER-specific Prx4 in tracking changes in adipocyte differentiation and lipid accumulation. Overexpression of Prx4 reduced ER stress and suppressed lipid accumulation by regulating adipogenic gene expression during adipogenesis. Our results demonstrate that Prx4 inhibits ER stress, lowers ROS levels, and attenuates pre-adipocyte differentiation. These findings suggested enhancing the activity of Prx4 may be helpful in the treatment of obesity; the data also support the development of new therapeutic approaches to obesity and obesity-related metabolic disorders.


Assuntos
Adipócitos/metabolismo , Adipogenia/genética , Estresse do Retículo Endoplasmático/genética , Insulina/farmacologia , Obesidade/metabolismo , Peroxirredoxinas/metabolismo , Células 3T3-L1 , Adipócitos/efeitos dos fármacos , Adipócitos/enzimologia , Adipogenia/efeitos dos fármacos , Animais , Cálcio/metabolismo , Retículo Endoplasmático/metabolismo , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica/genética , Metabolismo dos Lipídeos/genética , Camundongos , Obesidade/genética , Peroxirredoxinas/genética , Espécies Reativas de Oxigênio/metabolismo
13.
Artigo em Chinês | MEDLINE | ID: mdl-32062888

RESUMO

Objective: To investigate the effect of peroxiredoxin 2 (Prx2) overexpression on fibroblast proliferation and collagen synthesis induced by transforming growth factor-ß1 (TGF-ß1) . Methods: Fibroblasts were randomly divided into control group (DMEM medium) , TGF-ß1 group (5 µg/L TGF-ß1) , negative control group (treated with 5 µg/L TGF-ß1 and transfected with empty lentiviral vector) , and Prx2 group (treated with 5 µg/L TGF-ß1 and transfected with Prx2 overexpression lentiviral vector) . MTT assay was used to measure cell proliferation, immunofluorescence assay was used to measure the expression of 8-OHdG, and Western blot was used to measure the expression of p-JNK, p-P38, collagen type I, collagen type III, and Prx2. SPSS 18.0 was used for statistical analysis. The continuous data were expressed as mean±standard deviation; an analysis of variance was used for comparison between groups, and the least significant difference t-test was used for further comparison between two groups. Results: Lentiviral transfection was performed successfully, and the Prx2 group had a significant increase in the protein expression of Prx2 (P<0.05) . Compared with the control group, the TGF-ß1 group had a significant increase in the proliferation ability (P<0.05) , and compared with the TGF-ß1 group, the Prx2 group had a significant reduction in the proliferation ability (P<0.05) . Compared with the control group, the TGF-ß1 group had significant increases in the expression of 8-OHdG, p-JNK, p-P38, collagen type I, and collagen type III (P<0.05) ; compared with the TGF-ß1 group, the negative control group had no significant changes in the expression of 8-OHdG, p-JNK, p-P38, collagen type I, and collagen type III (P>0.05) , while the Prx2 group had significant reductions in the above parameters (P<0.05) . Conclusion: Prx2 overexpression inhibits fibroblast proliferation and collagen synthesis induced by TGF-ß1 through inhibiting reactive oxygen species and activating the JNK and P38 pathways.


Assuntos
Proliferação de Células , Colágeno Tipo I/biossíntese , Fibroblastos/citologia , Peroxirredoxinas/genética , Fator de Crescimento Transformador beta1/farmacologia , Células Cultivadas , Fibroblastos/efeitos dos fármacos , Humanos , Transdução de Sinais , Transfecção
14.
Arch Virol ; 165(4): 809-822, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32103340

RESUMO

Oxidative stress is the process by which reactive molecules and free radicals are formed in cells. In this study, we report the blood-based gene expression profile of oxidative stress and antioxidant genes for identifying surrogate markers of liver tissue in chronic hepatitis C (CHC) patients by using real-time PCR. A total of 144 untreated patients diagnosed with CHC having genotype 3a and 20 healthy controls were selected for the present study. Liver biopsy staging and grading of CHC patients were performed using the METAVIR score. Total RNA was extracted from liver tissue and blood samples, followed by cDNA synthesis and real-time PCR. The relative expression of genes was calculated using the ΔΔCt method. The expression profile of 84 genes associated with oxidative stress and antioxidants was determined in liver tissue and blood samples. In liver tissue, 46 differentially expressed genes (upregulated, 27; downregulated, 19) were identified in CHC patients compared to normal samples. In blood, 61 genes (upregulated, 51; downregulated; 10) were significantly expressed in CHC patients. A comparison of gene expression in liver and whole blood showed that 20 genes were expressed in a similar manner in the liver and blood. The expression levels of commonly expressed liver and blood-based genes were also correlated with clinical factors in CHC patients. A receiver operating curve (ROC) analysis of oxidative stress genes (ALB, CAT, DHCR24, GPX7, PRDX5, and MBL2) showed that infections in patients with CHC can be distinguished from healthy controls. In conclusion, blood-based gene expression can reflect the behavior of oxidative stress genes in liver tissue, and this blood-based gene expression study in CHC patients explores new blood-based non-invasive biomarkers that represent liver damage.


Assuntos
Hepatite C Crônica/sangue , Fígado/metabolismo , Estresse Oxidativo , Adulto , Biomarcadores/sangue , Feminino , Regulação Neoplásica da Expressão Gênica , Hepatite C Crônica/genética , Humanos , Fígado/lesões , Masculino , Pessoa de Meia-Idade , Proteínas do Tecido Nervoso/sangue , Proteínas do Tecido Nervoso/genética , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/sangue , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/genética , Peroxidases/sangue , Peroxidases/genética , Peroxirredoxinas/sangue , Peroxirredoxinas/genética , Adulto Jovem
15.
Cell Commun Signal ; 18(1): 15, 2020 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-31987042

RESUMO

BACKGROUND: We have previously shown that the zinc finger transcription repressor SNAI2 (SLUG) represses tumor suppressor BRCA2-expression in non-dividing cells by binding to the E2-box upstream of the transcription start site. However, it is unclear how proliferating breast cancer (BC) cells that has higher oxidation state, overcome this repression. In this study, we provide insight into the mechanism of de-silencing of BRCA2 gene expression by PRDX5A, which is the longest member of the peroxiredoxin5 family, in proliferating breast cancer cells. METHODS: We used cell synchronization and DNA affinity pulldown to analyze PRDX5A binding to the BRCA2 silencer. We used oxidative stress and microRNA (miRNA) treatments to study nuclear localization of PRDX5A and its impact on BRCA2-expression. We validated our findings using mutational, reporter assay, and immunofluorescence analyses. RESULTS: Under oxidative stress, proliferating BC cells express PRDX5 isoform A (PRDX5A). In the nucleus, PRDX5A binds to the BRCA2 silencer near the E2-box, displacing SLUG and enhancing BRCA2-expression. Nuclear PRDX5A is translated from the second AUG codon in frame to the first AUG codon in the PRDX5A transcript that retains all exons. Mutation of the first AUG increases nuclear localization of PRDX5A in MDA-MB-231 cells, but mutation of the second AUG decreases it. Increased mitronic hsa-miRNA-6855-3p levels under oxidative stress renders translation from the second AUG preferable. Mutational analysis using reporter assay uncovered a miR-6855-3p binding site between the first and second AUG codon in the PRDX5A transcript. miR-6855-3p mimic increases accumulation of nuclear PRDX5A and inhibits reporter gene translation. CONCLUSION: Oxidative stress increases miR-6855-3p expression and binding to the inter-AUG sequence of the PRDX5A transcript, promoting translation of nuclear PRDX5A. Nuclear PRDX5A relieves SLUG-mediated BRCA2 silencing, resulting in increased BRCA2-expression.


Assuntos
Proteína BRCA2/metabolismo , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Inativação Gênica , MicroRNAs/metabolismo , Peroxirredoxinas/metabolismo , Fatores de Transcrição da Família Snail/metabolismo , Proteína BRCA2/genética , Núcleo Celular/genética , Núcleo Celular/metabolismo , Feminino , Humanos , MicroRNAs/genética , Oxirredução , Estresse Oxidativo , Peroxirredoxinas/genética , Ligação Proteica , Transporte Proteico , Fatores de Transcrição da Família Snail/genética
16.
Oncogene ; 39(2): 356-367, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31477836

RESUMO

Reactive oxygen species (ROS) and ROS-induced oxidative stress are associated with prostate cancer (PCa) development and castrate-resistant tumor progression. This is in part through the activation of the androgen receptor (AR) signaling. However, the molecular underpinning of ROS to activate AR remains poorly understood. Here, we report that the thioredoxin domain-containing 9 (TXNDC9) is an important regulator of ROS to trigger AR signaling. TXNDC9 expression is upregulated by ROS inducer, and increased TXNDC9 expression in patient tumors is associated with advanced clinical stages. TXNDC9 promotes PCa cell survival and proliferation. It is required for AR protein expression and AR transcriptional activity under oxidative stress conditions. Mechanistically, ROS inducers promote TXNDC9 to dissociate from PRDX1, but enhance a protein association with MDM2. Concurrently, PRDX1 enhances its association with AR. These protein interaction exchanges result in not only MDM2 protein degradation, but also PRDX1 mediated AR protein stabilization, and subsequent elevation of AR signaling. Blocking PRDX1 by its inhibitor, Conoidin A (CoA), suppresses AR signaling, PCa cell proliferation, and xenograft tumor growth even under androgen-deprived conditions. These tumor-suppressive effects of CoA were further strengthened when in combination with enzalutamide treatment. Together, these studies demonstrate that the TXNDC9-PRDX1 axis plays an important role for ROS to activate AR functions. It provides a proof-of-principle that co-targeting AR and PRDX1 may be more effective to control PCa growth.


Assuntos
Peroxirredoxinas/genética , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico , Receptores Androgênicos/genética , Tiorredoxinas/genética , Animais , Proliferação de Células/genética , Progressão da Doença , Regulação Neoplásica da Expressão Gênica/genética , Xenoenxertos , Humanos , Masculino , Camundongos , Estresse Oxidativo/genética , Peroxirredoxinas/antagonistas & inibidores , Feniltioidantoína/análogos & derivados , Feniltioidantoína/farmacologia , Próstata/metabolismo , Próstata/patologia , Neoplasias de Próstata Resistentes à Castração/genética , Neoplasias de Próstata Resistentes à Castração/patologia , Estabilidade Proteica , Proteínas Proto-Oncogênicas c-mdm2/genética , Quinoxalinas/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais
17.
Redox Biol ; 28: 101315, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31505325

RESUMO

Non-alcoholic fatty liver disease (NAFLD) is becoming the most common chronic liver disease globally. NAFLD-which can develop into liver fibrosis, nonalcoholic steatohepatosis, cirrhosis, and hepatocellular carcinoma-is defined as an excess accumulation of fat caused by abnormal lipid metabolism and excessive reactive oxygen species (ROS) generation in hepatocytes. Recently, we reported that Peroxiredoxin 5 (Prx5) plays an essential role in regulating adipogenesis and suggested the need to further investigation on the potential curative effects of Prx5 on obesity-induced fatty liver disease. In the present study, we focused on the role of Prx5 in fatty liver disease. We found that Prx5 overexpression significantly suppressed cytosolic and mitochondrial ROS generation. Additionally, Prx5 regulated the AMP-activated protein kinase pathway and lipogenic gene (sterol regulatory element binding protein-1 and FAS) expression; it also inhibited lipid accumulation, resulting in the amelioration of free fatty acid-induced hepatic steatosis. Silence of Prx5 triggered de novo lipogenesis and abnormal lipid accumulation in HepG2 cells. Concordantly, Prx5 knockout mice exhibited a high susceptibility to obesity-induced hepatic steatosis. Liver sections of Prx5-deletion mice fed on a high-fat diet displayed Oil Red O-stained dots and small leaky shapes due to immoderate fat deposition. Collectively, our findings suggest that Prx5 functions as a protective regulator in fatty liver disease and that it may be a valuable therapeutic target for the management of obesity-related metabolic diseases.


Assuntos
Dieta Hiperlipídica/efeitos adversos , Hepatopatia Gordurosa não Alcoólica/genética , Obesidade/genética , Peroxirredoxinas/genética , Proteínas Quinases Ativadas por AMP/metabolismo , Animais , Modelos Animais de Doenças , Técnicas de Inativação de Genes , Células Hep G2 , Humanos , Metabolismo dos Lipídeos , Masculino , Camundongos , Hepatopatia Gordurosa não Alcoólica/etiologia , Hepatopatia Gordurosa não Alcoólica/metabolismo , Obesidade/induzido quimicamente , Obesidade/complicações , Obesidade/metabolismo , Estresse Oxidativo , Transdução de Sinais
18.
Redox Biol ; 28: 101319, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31536951

RESUMO

BACKGROUND: Helicobacter pylori (H. pylori) infection is the main risk factor for gastric cancer. The role of antioxidant enzyme peroxiredoxin 2 (PRDX2) in gastric tumorigenesis remains unknown. In vitro (AGS and SNU-1 cell lines) and in vivo mouse models were utilized to investigate the role of PRDX2 in response to H. pylori infection (7.13, J166 or PMSS1 strain). We detected high levels of PRDX2 expression in gastric cancer tissues. Gastric cancer patients with high expression levels of PRDX2 had significantly worse overall and progression-free survival than those with low levels. H. pylori infection induced activation of NF-κB with increased expression of PRDX2, in in vitro and in vivo models. The knockdown of PRDX2 led to an increase in the levels of reactive oxygen species (ROS), oxidative DNA damage, and double-strand DNA breaks, in response to H. pylori infection, as measured by H2DCFDA, 8-oxoguanine, and p-H2AXγ assays. Luciferase reporter and ChIP assays confirmed the presence of a putative binding site of NF-κB-p65 on PRDX2 promoter region. The inhibition of PRDX2 significantly sensitized AGS and SNU-1 cells to cisplatin treatment. Our data suggest that the future development of therapeutic approaches targeting PRDX2 may be useful in the treatment of gastric cancer.


Assuntos
Cisplatino/farmacologia , Infecções por Helicobacter/metabolismo , Peroxirredoxinas/genética , Peroxirredoxinas/metabolismo , Neoplasias Gástricas/metabolismo , Regulação para Cima , Animais , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Infecções por Helicobacter/complicações , Infecções por Helicobacter/genética , Helicobacter pylori/patogenicidade , Humanos , Camundongos , Estadiamento de Neoplasias , Estresse Oxidativo , Prognóstico , Neoplasias Gástricas/etiologia , Neoplasias Gástricas/genética , Análise de Sobrevida
19.
Acta Trop ; 201: 105217, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31605692

RESUMO

Glycosomes of trypanosomatids are peroxisome-like organelles comprising unique metabolic features, among which the lack of the hallmark peroxisomal enzyme catalase. The absence of this highly efficient peroxidase from glycosomes is presumably compensated by other antioxidants, peroxidases of the peroxiredoxin (PRX) family being the most promising candidates for this function. Here, we follow on this premise and investigate the product of a Leishmania infantum gene coding for a putative glycosomal PRX (LigPRX). First, we demonstrate that LigPRX localizes to glycosomes, resorting to indirect immunofluorescence analysis. Second, we prove that purified recombinant LigPRX is an active peroxidase in vitro. Third, we generate viable LigPRX-depleted L. infantum promastigotes by classical homologous recombination. Surprisingly, phenotypic analysis of these knockout parasites revealed that promastigote survival, replication, and protection from oxidative and nitrosative insults can proceed normally in the absence of LigPRX. Noticeably, we also witness that LigPRX-depleted parasites can infect and thrive in mice to the same extent as wild type parasites. Overall, by disclosing the dispensable character of the glycosomal peroxiredoxin in L. infantum, this work excludes this enzyme from being a key component of the glycosomal hydroperoxide metabolism and contemplates alternative players for this function.


Assuntos
Leishmania infantum/genética , Leishmania infantum/metabolismo , Microcorpos/metabolismo , Oxirredutases/metabolismo , Peroxirredoxinas/metabolismo , Proteínas de Protozoários/genética , Proteínas de Protozoários/metabolismo , Animais , Camundongos , Microcorpos/genética , Oxirredutases/genética , Peroxirredoxinas/genética
20.
Microb Pathog ; 139: 103890, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31765768

RESUMO

Neisseria meningitidis is a human-restricted bacterium that can invade the bloodstream and cross the blood-brain barrier resulting in life-threatening sepsis and meningitis. Meningococci express a cytoplasmic peroxiredoxin-glutaredoxin (Prx5-Grx) hybrid protein that has also been identified on the bacterial surface. Here, recombinant Prx5-Grx was confirmed as a plasminogen (Plg)-binding protein, in an interaction which could be inhibited by the lysine analogue ε-aminocapronic acid. rPrx5-Grx derivatives bearing a substituted C-terminal lysine residue (rPrx5-GrxK244A), but not the active site cysteine residue (rPrx5-GrxC185A) or the sub-terminal rPrx5-GrxK230A lysine residue, exhibited significantly reduced Plg-binding. The absence of Prx5-Grx did not significantly reduce the ability of whole meningococcal cells to bind Plg, but under hydrogen peroxide-mediated oxidative stress, the N. meningitidis Δpxn5-grx mutant survived significantly better than the wild-type or complemented strains. Significantly, using human whole blood as a model of meningococcal bacteremia, it was found that the N. meningitidis Δpxn5-grx mutant had a survival defect compared with the parental or complemented strain, confirming an important role for Prx5-Grx in meningococcal pathogenesis.


Assuntos
Glutarredoxinas/metabolismo , Interações Hospedeiro-Patógeno , Infecções Meningocócicas/metabolismo , Infecções Meningocócicas/microbiologia , Neisseria meningitidis/fisiologia , Peroxirredoxinas/metabolismo , Plasminogênio/metabolismo , Ensaio de Imunoadsorção Enzimática , Glutarredoxinas/química , Glutarredoxinas/genética , Humanos , Peróxido de Hidrogênio/metabolismo , Infecções Meningocócicas/diagnóstico , Infecções Meningocócicas/mortalidade , Mutação , Peroxirredoxinas/química , Peroxirredoxinas/genética , Plasminogênio/química , Prognóstico , Ligação Proteica , Domínios e Motivos de Interação entre Proteínas
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA