Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.507
Filtrar
1.
Chem Biol Interact ; 330: 109114, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32735800

RESUMO

Tebuconazole (TEB) is a broad-spectrum conazole fungicide that has been used in agriculture in the control of foliar and soil-borne diseases of many crops. The present study has investigated the adverse effects of subchronic exposure to TEB on the kidney of male rats. Animals were divided into four equal groups and treated with TEB at increasing doses 0.9, 9 and 27 mg/kg body weight for 28 consecutive days. The results showed that TEB induced oxidative stress in the kidney demonstrated by an increase in malondialdehyde (MDA), protein carbonyl (PC), advanced oxidation protein product (AOPP) levels and DNA damage, as compared to the controls. Furthermore, superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) activities were increased in the renal tissue of treated rats. Moreover, significant decrease in reduced glutathione (GSH) content in TEB-treated rats was observed, while oxidized glutathione (GSSG) levels were increased, thus a marked fall in GSH/GSSG ratio was registered in the kidney. Glutathione reductase (GR) activity showed a significant increase after TEB exposure. Moreover, TEB down-regulated the expression of Bcl2 and up-regulated the expression of Bax and caspase 3, which triggered apoptosis via the Bax/Bcl2 and caspase pathway. Also, TEB administration resulted in altered biochemical indicators of renal function and varying lesions in the overall histo-architecture of renal tissues. Taken together, our findings brought into light the renal toxicity induced by TEB, which was found to be significant at low doses.


Assuntos
Apoptose/efeitos dos fármacos , Dano ao DNA/efeitos dos fármacos , Rim/patologia , Estresse Oxidativo/efeitos dos fármacos , Triazóis/toxicidade , Animais , Relação Dose-Resposta a Droga , Fungicidas Industriais/toxicidade , Regulação da Expressão Gênica , Glutationa/metabolismo , Dissulfeto de Glutationa/metabolismo , Glutationa Redutase/metabolismo , Rim/efeitos dos fármacos , Rim/metabolismo , Masculino , Oxirredução , Ratos , Ratos Wistar
2.
Sci Rep ; 10(1): 4881, 2020 03 17.
Artigo em Inglês | MEDLINE | ID: mdl-32184402

RESUMO

The current study aims to investigate retinal vascular function and its relationship with systemic anti-oxidative defence capacity in normal individuals versus those with early hypertensive changes according to the current ESC/ESH guidelines. Retinal microvascular function was assessed in 201 participants by means of dynamic retinal vessel analysis. Blood pressure, lipid panel, oxidized (GSH) & reduced glutathione (GSSG) were also evaluated for each participant. Individuals classed as grade 1 hypertension demonstrated higher retinal arterial baseline diameter fluctuation (p = 0.0012), maximum dilation percentage (p = 0.0007), time to maximum constriction (p = 0.0003) and lower arterial constriction slope (p = 0.0131). Individuals classed as high normal and grade 1 hypertension also demonstrated higher time to maximum dilation than individuals classed as optimal or normal. GSH levels correlated negatively with SBP, DBP and MBP values in all participants (p = 0.0010; p = 0.0350 and p = 0.0050) as well as with MBP values in high normal and grade 1 hypertension (p = 0.0290). The levels of GSSG correlated positively with SBP, DBP and MBP values in all participants (p = 0.0410; p = 0.0330 and, p = 0.0220). Our results point to the fact that microvascular alterations can be identifiable at BP values still considered within normal values and go in parallel with the changes observed in the level of oxidative stress.


Assuntos
Doenças Cardiovasculares/metabolismo , Doenças Cardiovasculares/fisiopatologia , Estresse Oxidativo/fisiologia , Adulto , Biomarcadores/metabolismo , Pressão Sanguínea/genética , Pressão Sanguínea/fisiologia , Doenças Cardiovasculares/genética , Feminino , Glutationa/metabolismo , Dissulfeto de Glutationa/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Estresse Oxidativo/genética , Retina/metabolismo
3.
J Biol Chem ; 295(10): 3055-3063, 2020 03 06.
Artigo em Inglês | MEDLINE | ID: mdl-32001619

RESUMO

In human cancer cells that harbor mutant KRAS and WT p53 (p53), KRAS contributes to the maintenance of low p53 levels. Moreover, KRAS depletion stabilizes and reactivates p53 and thereby inhibits malignant transformation. However, the mechanism by which KRAS regulates p53 is largely unknown. Recently, we showed that KRAS depletion leads to p53 Ser-15 phosphorylation (P-p53) and increases the levels of p53 and its target p21/WT p53-activated fragment 1 (WAF1)/CIP1. Here, using several human lung cancer cell lines, siRNA-mediated gene silencing, immunoblotting, quantitative RT-PCR, promoter-reporter assays, and reactive oxygen species (ROS) assays, we demonstrate that KRAS maintains low p53 levels by activating the NRF2 (NFE2-related factor 2)-regulated antioxidant defense system. We found that KRAS depletion led to down-regulation of NRF2 and its targets NQO1 (NAD(P)H quinone dehydrogenase 1) and SLC7A11 (solute carrier family 7 member 11), decreased the GSH/GSSG ratio, and increased ROS levels. We noted that the increase in ROS is required for increased P-p53, p53, and p21Waf1/cip1 levels following KRAS depletion. Downstream of KRAS, depletion of RalB (RAS-like proto-oncogene B) and IκB kinase-related TANK-binding kinase 1 (TBK1) activated p53 in a ROS- and NRF2-dependent manner. Consistent with this, the IκB kinase inhibitor BAY11-7085 and dominant-negative mutant IκBαM inhibited NF-κB activity and increased P-p53, p53, and p21Waf1/cip1 levels in a ROS-dependent manner. In conclusion, our findings uncover an important role for the NRF2-regulated antioxidant system in KRAS-mediated p53 suppression.


Assuntos
Antioxidantes/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Sistema y+ de Transporte de Aminoácidos/metabolismo , Linhagem Celular Tumoral , Inibidor de Quinase Dependente de Ciclina p21/genética , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Regulação para Baixo , Glutationa/metabolismo , Dissulfeto de Glutationa/metabolismo , Humanos , NAD(P)H Desidrogenase (Quinona)/metabolismo , Fosforilação , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Proto-Oncogênicas p21(ras)/antagonistas & inibidores , Proteínas Proto-Oncogênicas p21(ras)/genética , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais , Proteína Supressora de Tumor p53/genética , Proteínas ral de Ligação ao GTP/antagonistas & inibidores , Proteínas ral de Ligação ao GTP/genética , Proteínas ral de Ligação ao GTP/metabolismo
4.
Oxid Med Cell Longev ; 2019: 2192093, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31772701

RESUMO

Resistin is an adipokine involved in inflammation and able to induce the expression of other proinflammatory cytokines. It is known that, in human semen, resistin is correlated with inflammatory cytokines and sperm quality. The aim of this prospective study was to explore the potential relationship between resistin, lipid peroxidation (LPO), catalase (CAT) activity, and reduced and oxidized glutathione (GSH/GSSG) ratio in semen samples of infertile patients with leukocytospermia (no. 19), infertile patients with varicocele (no. 17), and fertile men (no. 17). Semen analysis was performed following the WHO guidelines, and sperm apoptosis and necrosis were evaluated with annexin V/propidium iodide assay. Seminal plasma samples were used to determine resistin levels by an immunological method, MDA concentration by a HPLC analysis with UV detection, GSH/GSSG ratio by an enzymatic method, CAT activity by a spectrophotometric method. The results showed that, in both groups of infertile patients, semen parameters were significantly reduced (P < 0.001) and sperm apoptosis and necrosis percentages were increased. Resistin levels were significantly higher in leukocytospermia and varicocele groups (P < 0.001 and P < 0.01, respectively) as well as MDA concentration (P < 0.001) compared to controls. The MDA level was also significantly increased in the leukocytospermia group versus the varicocele group (P < 0.05). The GSH/GSSG ratio was higher in fertile controls than the leukocytospermia group (P < 0.05) and the varicocele group (P < 0.001) and in the leukocytospermia group versus the varicocele group (P < 0.05). Both the leukocytospermia and varicocele groups showed increased values of CAT activities (P < 0.001) than controls. Briefly, the correlation between variables, calculated in the whole patient population, showed that resistin levels positively correlated with MDA levels, CAT activity, sperm apoptosis, and necrosis and negatively with sperm parameters and GSH/GSSG ratio. These results support an active role of resistin in an inflammatory process causing LPO, increase of CAT activity, and decrease of GSH/GSSG ratio in seminal plasma of infertile men vs. fertile controls.


Assuntos
Dissulfeto de Glutationa/metabolismo , Resistina/metabolismo , Sêmen/metabolismo , Adulto , Humanos , Peroxidação de Lipídeos , Masculino
5.
Oxid Med Cell Longev ; 2019: 7261842, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31781347

RESUMO

Ghrelin and obestatin are involved in many biological functions including reproduction. Growing evidences suggest that both peptides could exert protective and antioxidant activities. In this study, the relationships between ghrelin/obestatin, interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), malondialdehyde (MDA), reduced glutathione (GSH), oxidized glutathione (GSSG), expressed as the GSH/GSSG ratio, catalase (CAT), and semen parameters in infertile patients with varicocele or leukocytospermia and controls were investigated. Fifty-six infertile patients (32 with leukocytospermia and 24 with varicocele) and 14 controls participated in this study. Semen analysis was performed following the WHO guidelines. Apoptotic and necrotic sperm were scored by annexin V/propidium iodide assay. Seminal plasma samples were used for the following determinations: ghrelin, obestatin, IL-6, and TNF-α were measured by an immunological method, GSH/GSSG by an enzymatic method, and CAT by spectrophotometric determination. With respect to controls, both the leukocytospermia and varicocele groups showed altered sperm parameters, significantly increased sperm apoptosis (P = 0.009 and P = 0.011, respectively), IL-6 (P = 0.0001 and P = 0.004, respectively), and TNF-α levels (P = 0.0001 and P = 0.002, respectively); both groups had significantly decreased levels of ghrelin (P = 0.0001), obestatin (P = 0.0001 and P = 0.006, respectively), and GSH/GSSG ratio (P = 0.003 and P = 0.0001, respectively). The MDA concentration was significantly increased in the leukocytospermia group vs. controls (P = 0.0001), in the varicocele group vs. controls (P = 0.011), and in the leukocytospermia group vs. the varicocele group (P = 0.008). CAT activity was augmented in both the leukocytospermia and varicocele groups (P = 0.0001)vs. controls. The results indicate that both ghrelin and obestatin may play a protective role in human semen and this effect is probably due to their antioxidant properties.


Assuntos
Catalase/metabolismo , Grelina/metabolismo , Dissulfeto de Glutationa/metabolismo , Infertilidade Masculina/metabolismo , Interleucina-6/metabolismo , Sêmen/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Varicocele/metabolismo , Adulto , Humanos , Infertilidade Masculina/patologia , Masculino , Varicocele/patologia
6.
Int J Mol Sci ; 20(21)2019 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-31683668

RESUMO

Many details of oxidative folding of proteins remain obscure, in particular, the role of oxidized glutathione (GSSG). This study reveals some unknown aspects. When a reduced ribonuclease A refolds in the presence of GSSG, most of its eight cysteines accomplish a very fast glutathionylation. In particular, one single cysteine, identified as Cys95 by mass spectrometry, displays 3600 times higher reactivity when compared with an unperturbed protein cysteine. Furthermore, the other five cysteines show 40-50 times higher reactivity toward GSSG. This phenomenon is partially due to a low pKa value of most of these cysteines (average pKa = 7.9), but the occurrence of a reversible GSSG-ribonuclease complex (KD = 0.12 mM) is reasonably responsible for the extraordinary hyper-reactivity of Cys95. Neither hyper-reactivity nor some protein-disulfide complexes have been found by reacting a reduced ribonuclease with other natural disulfides i.e., cystine, cystamine, and homocystine. Hyper-reactivity of all cysteines was observed toward 5,5'-dithiobis-(2-nitrobenzoic acid). Given that GSSG is present in high concentrations in the endoplasmic reticulum, this property may shed light on the early step of its oxidative folding. The ultra-rapid glutathionylation of cysteines, only devoted to form disulfides, is a novel property of the molten globule status of the ribonuclease.


Assuntos
Cisteína/metabolismo , Dissulfeto de Glutationa/metabolismo , Glutationa/metabolismo , Ribonucleases/metabolismo , Animais , Bovinos , Dissulfetos/metabolismo , Ácido Ditionitrobenzoico/metabolismo , Concentração de Íons de Hidrogênio , Oxirredução , Estresse Oxidativo , Isomerases de Dissulfetos de Proteínas/metabolismo , Dobramento de Proteína , Ribonuclease Pancreático/química , Ribonuclease Pancreático/metabolismo , Ribonucleases/química , Compostos de Sulfidrila/metabolismo , Espectrometria de Massas em Tandem
7.
Redox Biol ; 26: 101294, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31450104

RESUMO

Previous studies have shown a significant increase in the mitochondrial generation of hydrogen peroxide (H2O2) and other peroxides in recently denervated muscle fibers. The mechanisms for generation of these peroxides and how the muscle responds to these peroxides are not fully established. The aim of this work was to determine the effect of denervation on the muscle content of proteins that may contribute to mitochondrial peroxide release and the muscle responses to this generation. Denervation of the tibialis anterior (TA) and extensor digitorum longus (EDL) muscles in mice was achieved by surgical removal of a small section of the peroneal nerve prior to its entry into the muscle. An increase in mitochondrial peroxide generation has been observed from 7 days and sustained up to 21 days following denervation in the TA muscle fibers. This increased peroxide generation was reduced by incubation of skinned fibers with inhibitors of monoamine oxidases, NADPH oxidases or phospholipase A2 enzymes and the muscle content of these enzymes together with peroxiredoxin 6 were increased following denervation. Denervated muscle also showed significant adaptations in the content of several enzymes involved in the protection of cells against oxidative damage. Morphological analyses indicated a progressive significant loss of muscle mass in the TA muscle from 7 days up to 21 days following denervation due to fiber atrophy but without fiber loss. These results support the possibility that, at least initially, the increase in peroxide production may stimulate adaptations in an attempt to protect the muscle fibers, but that these processes are insufficient and the increased peroxide generation over the longer term may activate degenerative and atrophic processes in the denervated muscle fibers.


Assuntos
Denervação Muscular , Músculo Esquelético/inervação , Músculo Esquelético/metabolismo , Oxirredução , Animais , Dissulfeto de Glutationa/metabolismo , Peróxido de Hidrogênio/metabolismo , Imuno-Histoquímica , Masculino , Camundongos , Camundongos Transgênicos , Mitocôndrias Musculares/metabolismo , Proteínas Mitocondriais/metabolismo , Fibras Musculares Esqueléticas/metabolismo , Fibras Musculares Esqueléticas/patologia , Músculo Esquelético/patologia , Transporte Proteico
8.
PLoS One ; 14(8): e0221160, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31412084

RESUMO

The rose-grass aphid (Methopolophium dirhodum Walk.) is a major pest of maize (Zea mays L.), but little is known about the biochemical interactions between M. dirhodum and its host plant. Thiol compounds and glutathione S-transferase (GST) play a crucial role in the defense responses of maize to biotic stress factors, including aphids. The purpose of this research was to evaluate the impact of M. dirhodum herbivory on the total thiol (TT), protein bound thiol (PT), reduced glutathione (GSH) and oxidized glutathione (GSSG) contents as well as the activity of GST in three varieties of Z. mays (Zlota Karlowa, Ambrozja and Plomyk), that were classified as aphid-susceptible, aphid-relatively resistant and aphid-resistant, respectively. The earliest and strongest aphid-triggered alterations in the levels of TT, PT and GSH, and the greatest induction of GST activity, were recorded in the resistant Plomyk seedlings in relation to the relatively resistant Ambrozja and the susceptible Zlota Karlowa.


Assuntos
Afídeos/fisiologia , Resistência à Doença , Dissulfeto de Glutationa/metabolismo , Glutationa Transferase/biossíntese , Proteínas de Plantas/metabolismo , Plântula , Zea mays , Animais , Doenças das Plantas/parasitologia , Folhas de Planta/metabolismo , Folhas de Planta/parasitologia , Plântula/metabolismo , Plântula/parasitologia , Zea mays/metabolismo , Zea mays/parasitologia
9.
Nano Lett ; 19(7): 4527-4534, 2019 07 10.
Artigo em Inglês | MEDLINE | ID: mdl-31244237

RESUMO

Reactive oxygen and nitrogen species (RONS), especially reactive nitrogen species (RNS) are intermediate products during incidence of nervous system diseases, showing continuous damage for traumatic brain injury (TBI). Here, we developed a carbogenic nanozyme, which shows an antioxidant activity 12 times higher than ascorbic acid (AA) and behaves as multienzyme mimetics. Importantly, the nanozyme exhibits an ultrahigh scavenging efficiency (∼16 times higher than AA) toward highly active RNS, such as •NO and ONOO- as well as traditional reactive oxygen species (ROS) including O2•-, H2O2, and •OH. In vitro experiments show that neuron cells injured by H2O2 or lipopolysaccharide can be significantly recovered after carbogenic nanozyme treatment via scavenging all kinds of RONS. Moreover, the carbogenic nanozyme can serve as various enzyme mimetics and eliminate the harmful peroxide and glutathione disulfide from injured mice, demonstrating its potential as a therapeutic for acute TBI.


Assuntos
Materiais Biomiméticos , Lesões Encefálicas Traumáticas , Dissulfeto de Glutationa/metabolismo , Peróxido de Hidrogênio/metabolismo , Nanoestruturas , Espécies Reativas de Nitrogênio/metabolismo , Doença Aguda , Animais , Materiais Biomiméticos/química , Materiais Biomiméticos/farmacologia , Lesões Encefálicas Traumáticas/tratamento farmacológico , Lesões Encefálicas Traumáticas/metabolismo , Lesões Encefálicas Traumáticas/patologia , Modelos Animais de Doenças , Camundongos , Nanoestruturas/química , Nanoestruturas/uso terapêutico
10.
Oxid Med Cell Longev ; 2019: 8219283, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31089418

RESUMO

Chronic kidney disease (CKD) is accompanied by a disturbed redox homeostasis, especially in end-stage patients, which is associated with pathological complications such as anemia, atherosclerosis, and muscle atrophy. However, limited evidence exists about redox disturbances before the end stage of CKD. Moreover, the available redox literature has not yet provided clear associations between circulating and tissue-specific (muscle) oxidative stress levels. The aim of the study was to evaluate commonly used redox status indices in the blood and in two different types of skeletal muscle (psoas, soleus) in the predialysis stages of CKD, using an animal model of renal insufficiency, and to investigate whether blood redox status indices could be reflecting the skeletal muscle redox status. Indices evaluated included reduced glutathione (GSH), oxidized glutathione (GSSG), glutathione reductase (GR), catalase (CAT), total antioxidant capacity (TAC), protein carbonyls (PC), and thiobarbituric acid reactive substances (TBARS). Results showed that blood GSH was higher in the uremic group compared to the control (17.50 ± 1.73 vs. 12.43 ± 1.01, p = 0.033). In both muscle types, PC levels were higher in the uremic group compared to the control (psoas: 1.086 ± 0.294 vs. 0.596 ± 0.372, soleus: 2.52 ± 0.29 vs. 0.929 ± 0.41, p < 0.05). The soleus had higher levels of TBARS, PC, GSH, CAT, and GR and lower TAC compared to the psoas in both groups. No significant correlations in redox status indices between the blood and skeletal muscles were found. However, in the uremic group, significant correlations between the psoas and soleus muscles in PC, GSSG, and CAT levels emerged, not present in the control. Even in the early stages of CKD, a disturbance in redox homeostasis was observed, which seemed to be muscle type-specific, while blood levels of redox indices did not seem to reflect the intramuscular condition. The above results highlight the need for further research in order to identify the key mechanisms driving the onset and progression of oxidative stress and its detrimental effects on CKD patients.


Assuntos
Músculo Esquelético/metabolismo , Insuficiência Renal/sangue , Insuficiência Renal/metabolismo , Animais , Catalase/metabolismo , Modelos Animais de Doenças , Feminino , Dissulfeto de Glutationa/metabolismo , Oxirredução , Carbonilação Proteica , Coelhos , Uremia/sangue
11.
Eur J Pharmacol ; 854: 159-166, 2019 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-30991047

RESUMO

After acute myocardial infarction (AMI), reactive oxygen species and oxidative stress have important roles in the progression to heart failure. As a therapeutic alternative, thyroid hormones (TH) revealed cardioprotective effects after AMI, including decreasing oxidative stress. Carvedilol beta-blocker, already used in the clinical treatment of AMI, also mitigate cardiac pathological remodelling. This study assessed the effects of post-AMI carvedilol and TH co-administration on oxidative stress and cardiac function as well as whether those effects were synergistic. Male Wistar rats were divided into five groups: sham-operated (SHAM), infarcted (MI), infarcted + TH (MI + TH), infarcted + carvedilol (MI + C) and infarcted + C + TH (MI + C + TH). Two days post-surgery, the SHAM and MI groups received saline, and treated groups received their respective treatments by gavage for 12 days. The animals were submitted to echocardiographic evaluation, ventricular catheterization and euthanized for heart collection to perform oxidative stress analysis. Treated groups improved for ejection fraction compared to the MI group. Carvedilol decreased the positive chronotropic TH effects in the MI + C + TH group. The MI and MI + C groups had increased reactive oxygen species and reduced sulfhydryl levels. Carvedilol and TH co-administration showed synergic effects in the MI + C + TH group, reducing reactive oxygen species levels and improving GSH/GSSG ratio. Moreover, co-treatment attenuated NADPH oxidase activity in the MI group. Therefore, this study showed for the first time that carvedilol and TH co-administration may improve redox balance and cardiac function after AMI. Such co-administration could represent a therapeutic strategy capable of preventing cardiac dysfunction and redox unbalance after AMI.


Assuntos
Carvedilol/farmacologia , Coração/efeitos dos fármacos , Coração/fisiopatologia , Infarto do Miocárdio/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Hormônios Tireóideos/farmacologia , Animais , Antioxidantes/metabolismo , Sinergismo Farmacológico , Eletrocardiografia/efeitos dos fármacos , Dissulfeto de Glutationa/metabolismo , Frequência Cardíaca/efeitos dos fármacos , Peroxidação de Lipídeos/efeitos dos fármacos , Masculino , Infarto do Miocárdio/sangue , Infarto do Miocárdio/fisiopatologia , NADPH Oxidases/metabolismo , Oxirredução , Ratos , Ratos Wistar , Espécies Reativas de Oxigênio/metabolismo , Compostos de Sulfidrila/metabolismo , Tireotropina/sangue
12.
PLoS One ; 14(4): e0215955, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31022254

RESUMO

Oxidative stress plays a key role in steatohepatitis induced by both xenobiotic agents and high fat diet (HFD). The present study aimed to evaluate hepatic oxidative stress and anti-oxidant systems response in rats exposed to HFD and/or non-toxic dose of dichlorodiphenyldichloroethylene (DDE), the first metabolite of dichlorodiphenyltrichloroethane. Groups of 8 rats were so treated for 4 weeks: 1- standard diet (N group); 2- standard diet plus DDE (10 mg/kg b.w.) (N+DDE group); 3- HFD (D group); 4- HFD plus DDE (D+DDE group). Oxidative stress was analyzed by determining malondialdehyde as lipid peroxidation product, while the anti-oxidant systems were evaluating by measuring the levels of the principal cytosolic and mitochondrial antioxidant proteins and enzymes, namely superoxide dismutase 1 and 2 (SOD1, SOD2), glutathione peroxidase 1 (GPx1) and uncoupling protein 2 (UCP2) involved in the control of hepatic reactive oxygens species (ROS) accumulation. The results showed malondialdehyde accumulation in livers of all groups, confirming the pro-oxidant effects of both HFD and DDE, but with a greater effect of DDE in absence of HFD. In addition, we found different levels of the analyzed anti-oxidant systems in the different groups. DDE mainly induced UCP2 and SOD2, while HFD mainly induced GPx1. Noteworthy, in the condition of simultaneous exposure to DDE and HFD, the anti-oxidant response was more similar to the one induced by HFD than to the response induced by DDE. Present findings confirmed that both HFD and xenobiotic exposure induced hepatic oxidative stress and showed that the anti-oxidant defense response was not the same in the diverse groups, suggesting that UCP2 induction could be an adaptive response to limit excessive ROS damage, mainly in condition of xenobiotic exposure.


Assuntos
Diclorodifenil Dicloroetileno/toxicidade , Dieta Hiperlipídica , Fígado Gorduroso/metabolismo , Fígado Gorduroso/patologia , Estresse Oxidativo/efeitos dos fármacos , Proteína Desacopladora 2/metabolismo , Xenobióticos/toxicidade , Animais , Antígenos CD/metabolismo , Antígenos de Diferenciação Mielomonocítica/metabolismo , Antioxidantes/metabolismo , Citocromo P-450 CYP2B1/metabolismo , Fígado Gorduroso/sangue , Regulação da Expressão Gênica/efeitos dos fármacos , Dissulfeto de Glutationa/metabolismo , Macrófagos do Fígado/efeitos dos fármacos , Macrófagos do Fígado/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Lipídeos/análise , Fígado/efeitos dos fármacos , Fígado/metabolismo , Fígado/patologia , Masculino , Metaboloma/efeitos dos fármacos , Oxirredução , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos Wistar , Proteína Desacopladora 2/genética , Ganho de Peso/efeitos dos fármacos
13.
Neurochem Res ; 44(7): 1613-1620, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30919283

RESUMO

Ischemic stroke is a leading cause of mortality and morbidity worldwide, and oxidative stress plays a significant role in the ischemia stage and reperfusion stage. Previous studies have indicated that both calcium/calmodulin-dependent protein kinase II (CaMKII) and glucose 6-phosphate dehydrogenase (G6PD) are involved in the oxidative stress. Thus, the aim of this study was to investigate the roles of CaMKIIα, an important isoform of CaMKII, and G6PD in a rat model of middle cerebral artery occlusion (MCAO). Intracerebroventricular injection of small interfering ribonucleic acid (siRNA) for CaMKIIα was performed at 48 h pre-MCAO surgery. Immunofluorescence Staining and western blot were performed to detect the expression of p-CaMKIIα and G6PD in the cortices. 2, 3, 5-Triphenyltetrazolium chloride (TTC) staining was performed to investigate the infarct volume. In addition, neurological deficit, reactive oxygen species (ROS), ratio of reduced-to-oxidized glutathione (GSH/GSSG) and ratio of reduced-to-oxidized oxidized nicotinamide adenine dinucleotide phosphate (NADPH/NADP+) were assessed. The results indicated that both p-CaMKIIα and G6PD were widely located in the neurons and astrocytes, and their expression was gradually increased in the cortices after MCAO, which was accompanied by increased level of ROS and decreased levels of GSH/GSSG and NADPH/NADP+. However, after treatment with siRNA for CaMKIIα, p-CaMKIIα expression was decreased and G6PD expression was increased. Moreover, inhibition of CaMKIIα improved the neurological deficit, reduced the infarct volume, decreased the level of ROS and increased the levels of GSH/GSSG and NADPH/NADP+. The results suggested that CaMKIIα inhibition exerted neuroprotective effects through regulating G6PD expression, which provides a new target for prevention and treatment of stroke.


Assuntos
Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/antagonistas & inibidores , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/metabolismo , Glucosefosfato Desidrogenase/metabolismo , Infarto da Artéria Cerebral Média/fisiopatologia , Estresse Oxidativo/fisiologia , Animais , Astrócitos/metabolismo , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/genética , Inativação Gênica , Dissulfeto de Glutationa/metabolismo , Masculino , NADP/metabolismo , Neurônios/metabolismo , RNA Interferente Pequeno/genética , Ratos Sprague-Dawley , Espécies Reativas de Oxigênio/metabolismo
14.
J Physiol Biochem ; 75(2): 185-197, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30868511

RESUMO

In this study, the effects of pharmacological concentrations of melatonin (1 µM-1 mM) on human pancreatic stellate cells (HPSCs) have been examined. Cell type-specific markers and expression of melatonin receptors were analyzed by western blot analysis. Changes in intracellular free Ca2+ concentration were followed by fluorimetric analysis of fura-2-loaded cells. Reduced glutathione (GSH) and oxidized glutathione (GSSG) levels were determined by fluorescence techniques. Production of reactive oxygen species (ROS) was monitored following 5-(and-6)-chloromethyl-2',7'-dichlorodihydrofluorescein diacetate acetyl ester and MitoSOX™ Red-derived fluorescence. Cell viability was studied using the AlamarBlue® test. Cultured cells expressed markers typical of stellate cells. However, cell membrane receptors for melatonin could not be detected. Thapsigargin, bradykinin, or melatonin induced changes in intracellular free Ca2+ concentration. In the presence of the indole, a decrease in the GSH/GSSG ratio was observed that depended on the concentration of melatonin used. Furthermore, the indole evoked a concentration-dependent increase in ROS production in the mitochondria and in the cytosol. Finally, melatonin decreased HPSC viability in a time and concentration-dependent manner. We conclude that melatonin, at pharmacological concentrations, induces changes in the oxidative state of HPSC. This might regulate cellular viability and could not involve specific plasma membrane receptors.


Assuntos
Glutationa/metabolismo , Melatonina/farmacologia , Células Estreladas do Pâncreas/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Animais , Cálcio/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Dissulfeto de Glutationa/metabolismo , Humanos , Camundongos , Pâncreas/metabolismo , Células Estreladas do Pâncreas/citologia , Células Estreladas do Pâncreas/efeitos dos fármacos , Ratos , Receptor MT1 de Melatonina/metabolismo
15.
Int J Mol Sci ; 20(6)2019 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-30893912

RESUMO

Age-related macular degeneration is the main cause of vision loss in the aged population worldwide. Drusen, extracellular lesions formed underneath the retinal pigment epithelial (RPE) cells, are a clinical feature of AMD and associated with AMD progression. RPE cells support photoreceptor function by providing nutrition, phagocytosing outer segments and removing metabolic waste. Dysfunction and death of RPE cells are early features of AMD. The translocator protein, TSPO, plays an important role in RPE cholesterol efflux and loss of TSPO results in increased intracellular lipid accumulation and reactive oxygen species (ROS) production. This study aimed to investigate the impact of TSPO knockout on RPE cellular metabolism by identifying the metabolic differences between wildtype and knockout RPE cells, with or without treatment with oxidized low density lipoprotein (oxLDL). Using liquid chromatography mass spectrometry (LC/MS), we differentiated several metabolic pathways among wildtype and knockout cells. Lipids amongst other intracellular metabolites were the most influenced by loss of TSPO and/or oxLDL treatment. Glucose, amino acid and nucleotide metabolism was also affected. TSPO deletion led to up-regulation of fatty acids and glycerophospholipids, which in turn possibly affected the cell membrane fluidity and stability. Higher levels of glutathione disulphide (GSSG) were found in TSPO knockout RPE cells, suggesting TSPO regulates mitochondrial-mediated oxidative stress. These data provide biochemical insights into TSPO-associated function in RPE cells and may shed light on disease mechanisms in AMD.


Assuntos
Células Epiteliais/metabolismo , Deleção de Genes , Metabolômica , Receptores de GABA/genética , Epitélio Pigmentado da Retina/citologia , Linhagem Celular , Análise Discriminante , Células Epiteliais/efeitos dos fármacos , Glucose/metabolismo , Dissulfeto de Glutationa/metabolismo , Humanos , Metabolismo dos Lipídeos/efeitos dos fármacos , Lipoproteínas LDL/farmacologia , Metaboloma/efeitos dos fármacos , Nucleotídeos/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Análise de Componente Principal , Receptores de GABA/metabolismo
16.
Eur J Dermatol ; 29(2): 167-173, 2019 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-30882351

RESUMO

Dermatitis herpetiformis (DH) and celiac disease (CD) are considered to be autoimmune diseases that share a specific trigger (gluten) and a common genetic background (HLA-DQ2/DQ8). However, the pathogenesis of DH is not yet fully understood and no data are available regarding a possible role of fibroblasts in this disease. The aim of this study was to assess baseline DNA damage in fibroblasts in DH-diagnosed patients vs. fibroblasts of controls without DH or CD. Primary fibroblast cultures were derived from dermal biopsies from DH patients and controls (without DH or CD). In vitro genotoxic damage was investigated using the comet assay and ɣH2AX test after different treatments (with 33mer peptide and digested gliadin [DG]) in order to investigate a correlation between oxidative stress (evaluated by reactive oxygen species formation) and glutathione content. Our results demonstrate a difference in baseline DNA damage between cutaneous fibroblasts of controls and DH patients, moreover, DNA damage significantly increased after exposure to gluten (DG and 33mer peptide) in fibroblasts from DH patients. DNA damage in fibroblasts from patients under dapsone treatment was similar to that of the control group. Our data indicate that oxidative stress and DNA damage may be characteristics of fibroblasts from DH patients who are not treated with dapsone, particularly after exposure to gliadin peptides.


Assuntos
Doença Celíaca/genética , Dano ao DNA , Dermatite Herpetiforme/genética , Fibroblastos/citologia , Adulto , Idoso , Doença Celíaca/imunologia , Ensaio Cometa , Dermatite Herpetiforme/imunologia , Feminino , Gliadina/metabolismo , Glutationa/metabolismo , Dissulfeto de Glutationa/metabolismo , Histonas/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Espécies Reativas de Oxigênio/metabolismo
17.
Neurochem Res ; 44(5): 1167-1181, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30806880

RESUMO

Menadione (2-methyl-1,4-naphthoquinone) is a synthetic derivative of vitamin K that allows rapid redox cycling in cells and thereby generates reactive oxygen species (ROS). To test for the consequences of a treatment of brain astrocytes with menadione, we incubated primary astrocyte cultures with this compound. Incubation with menadione in concentrations of up to 30 µM did not affect cell viability. In contrast, exposure of astrocytes to 100 µM menadione caused a time-dependent impairment of cellular metabolism and cell functions as demonstrated by impaired glycolytic lactate production and strong increases in the activity of extracellular lactate dehydrogenase and in the number of propidium iodide-positive cells within 4 h of incubation. In addition, already 5 min after exposure of astrocytes to menadione a concentration-dependent increase in the number of ROS-positive cells as well as a concentration-dependent and transient accumulation of cellular glutathione disulfide (GSSG) were observed. The rapid intracellular GSSG accumulation was followed by an export of GSSG that was prevented in the presence of MK571, an inhibitor of the multidrug resistance protein 1 (Mrp1). Menadione-induced glutathione (GSH) oxidation and ROS formation were found accelerated after glucose-deprivation, while the presence of dicoumarol, an inhibitor of the menadione-reducing enzyme NQO1, did not affect the menadione-dependent GSSG accumulation. Our study demonstrates that menadione rapidly depletes cultured astrocytes of GSH via ROS-induced oxidation to GSSG that is subsequently exported via Mrp1.


Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/efeitos dos fármacos , Astrócitos/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Dissulfeto de Glutationa/efeitos dos fármacos , Vitamina K 3/farmacologia , Animais , Astrócitos/metabolismo , Encéfalo/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Glutationa/efeitos dos fármacos , Glutationa/metabolismo , Dissulfeto de Glutationa/metabolismo , Glicólise/efeitos dos fármacos , Peróxido de Hidrogênio/metabolismo , Oxirredução , Ratos Wistar
18.
Redox Biol ; 21: 101050, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30654300

RESUMO

Cells evolved robust homeostatic mechanisms to protect against oxidation or alkylation by electrophilic species. Glutathione (GSH) is the most abundant intracellular thiol, protects cellular components from oxidation and is maintained in a reduced state by glutathione reductase (GR). Nitro oleic acid (NO2-OA) is an electrophilic fatty acid formed under digestive and inflammatory conditions that both reacts with GSH and induces its synthesis upon activation of Nrf2 signaling. The effects of NO2-OA on intracellular GSH homeostasis were evaluated. In addition to upregulation of GSH biosynthesis, we observed that NO2-OA increased intracellular GSSG in an oxidative stress-independent manner. NO2-OA directly inhibited GR in vitro by covalent modification of the catalytic Cys61, with kon of (3.45 ± 0.04) × 103 M-1 s-1, koff of (4.4 ± 0.4) × 10-4 s-1, and Keq of (1.3 ± 0.1) × 10-7 M. Akin to NO2-OA, the electrophilic Nrf2 activators bardoxolone-imidazole (CDDO-Im), bardoxolone-methyl (CDDO-Me) and dimethyl fumarate (DMF) also upregulated GSH biosynthesis while promoting GSSG accumulation, but without directly inhibiting GR activity. In vitro assays in which GR was treated with increasing GSH concentrations and GSH depletion experiments in cells revealed that GR activity is finely regulated via product inhibition, an observation further supported by theoretical (kinetic modeling of cellular GSSG:GSH levels) approaches. Together, these results describe two independent mechanisms by which electrophiles modulate the GSH/GSSG couple, and provide a novel conceptual framework to interpret experimentally determined values of GSH and GSSG.


Assuntos
Glutationa Redutase/química , Glutationa Redutase/metabolismo , Glutationa/biossíntese , Algoritmos , Alquilação , Sequência de Aminoácidos , Animais , Catálise , Domínio Catalítico , Dissulfeto de Glutationa/metabolismo , Espaço Intracelular , Cinética , Camundongos , Modelos Teóricos , Proteínas Associadas à Resistência a Múltiplos Medicamentos/antagonistas & inibidores , Proteínas Associadas à Resistência a Múltiplos Medicamentos/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Óxido Nítrico/metabolismo , Oxirredução , Estresse Oxidativo , Células RAW 264.7 , Espécies Reativas de Oxigênio , Compostos de Sulfidrila
19.
Ecotoxicol Environ Saf ; 171: 373-381, 2019 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-30616154

RESUMO

Considerable evidence exists that microorganisms play a significant role in the remediation of soil contaminated with heavy metals. Aspergillus aculeatus (A. aculeatus) isolated from Cd-polluted soil has been shown to increase the tolerance of turfgrasses to Cd stress. In this study, we assessed the tolerance, biosorption capacity for Cd and surface characteristics of this fungus and investigated the effect of plant inoculation with A. aculeatus on the lipid peroxidation, antioxidant activities and photosynthetic rates in rice cultivated in Cd-contaminated soil. The results indicated that the removal efficiency of A. aculeatus was 46.8% at a Cd concentration of 10 mg L-1. The A. aculeatus strains had the capacity to produce indole acetic acid, siderophore, and 1-aminocyclopropane-1-carboxylate deaminase and to solubilize phosphate. The O2- accumulation and the amount of MDA in rice roots inoculated with A. aculeatus were significantly lower than those in uninoculated plants. Nevertheless, no decrease in leaf ROS accumulation and photosynthetic activity was observed between the inoculated and uninoculated plants. Inoculation with A. aculeatus contained more of the ROS-scavenging metabolite GSH, a higher GSH/GSSG ratio, and higher antioxidative enzyme (SOD, POD, and CAT) activities, possibly explaining the lower ROS concentrations observed in inoculated roots in the presence of Cd. These results suggest that application of A. aculeatus has the potential to protect crops against Cd stress.


Assuntos
Antioxidantes/metabolismo , Aspergillus/efeitos dos fármacos , Cádmio/análise , Oryza/microbiologia , Fotossíntese , Aspergillus/metabolismo , Dissulfeto de Glutationa/metabolismo , Ácidos Indolacéticos , Peroxidação de Lipídeos , Malondialdeído/metabolismo , Oryza/efeitos dos fármacos , Fosfatos/metabolismo , Raízes de Plantas/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Sideróforos/metabolismo , Solo/química , Microbiologia do Solo , Poluentes do Solo/análise
20.
Animal ; 13(8): 1641-1650, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30458891

RESUMO

Glutathione (GSH) is considered to play an important role in maintaining the integrity of the small intestine. In piglets, altered mucosal GSH levels might therefore be involved in weaning-induced changes of the small intestinal morphology and barrier function. To test this hypothesis, we aimed to challenge the mucosal GSH redox status during the first 28 days after weaning, by feeding diets containing 5% fresh linseed oil (CON), or 2.5% (OF1) or 5% (OF2) peroxidized linseed oil (peroxide value 225 mEq O2/kg oil) and exploring the effects on gut integrity. Piglets were pair-fed and had a total daily feed allowance of 32 g/kg BW. A fourth treatment included animals that were fed the control diet ad libitum (ACON). Animals were sampled at days 5 and 28 post-weaning. The malondialdehyde (MDA) concentration and GSH redox status (GSH/GSSG Eh) were determined in blood, liver and small intestinal mucosa. Histomorphology of the duodenal and jejunal mucosa was determined, and Ussing chambers were used to assess fluorescein isothiocyanate dextran (FD4) and horseradish peroxidase (HRP) fluxes across the mucosa. Results show that peroxidized linseed oil imposed an oxidative challenge at day 28, but not at day 5 post-weaning. At day 28, increasing levels of dietary peroxides to pair-fed pigs linearly increased MDA levels in duodenal and jejunal mucosa. Moreover, FD4 fluxes were significantly increased in OF1 (+75%) and OF2 (+64%) in the duodenum, and HRP fluxes tended (P=0.099) to show similar differences, as compared to CON. This co-occurred with a significant 11 mV increase of the hepatic GSH/GSSG Eh, potentiated by a significantly increased GSH peroxidase activity for treatments OF1 (+47%) and OF2 (+63%) in liver as compared to CON. Furthermore; duodenal HRP flux significantly correlated with the hepatic glutathione disulphide (GSSG) level (r=0.650), as also observed in the jejunum for hepatic GSSG (r=0.627) and GSH/GSSG Eh (r=0.547). The jejunal permeability was not affected, but FD4 and HRP fluxes significantly correlated with the local GSH (r=0.619; r=0.733) and GSSG (r=0.635; r=0586) levels. Small intestinal histomorphology was not affected by dietary lipid peroxides, nor were there any correlations found with the GSH redox system. To conclude, under oxidative stress conditions, jejunal barrier function is related to the local and hepatic GSH redox system. It is suggested that the hepatic GSH system participates in the elimination of luminal peroxides, and thereby impacts on duodenal barrier function.


Assuntos
Glutationa/metabolismo , Intestino Delgado/efeitos dos fármacos , Óleo de Semente do Linho/farmacologia , Suínos/metabolismo , Ração Animal , Animais , Dieta/veterinária , Suplementos Nutricionais , Dissulfeto de Glutationa/metabolismo , Intestino Delgado/metabolismo , Intestino Delgado/fisiologia , Óleo de Semente do Linho/administração & dosagem , Óleo de Semente do Linho/química , Malondialdeído/metabolismo , Oxirredução , Estresse Oxidativo/efeitos dos fármacos , Desmame
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA