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1.
Nat Commun ; 12(1): 5243, 2021 09 02.
Artigo em Inglês | MEDLINE | ID: mdl-34475406

RESUMO

Peroxisome, a special cytoplasmic organelle, possesses one or more kinds of oxidases for hydrogen peroxide (H2O2) production and catalase for H2O2 degradation, which serves as an intracellular H2O2 regulator to degrade toxic peroxides to water. Inspired by this biochemical pathway, we demonstrate the reactive oxygen species (ROS) induced tumor therapy by integrating lactate oxidase (LOx) and catalase (CAT) into Fe3O4 nanoparticle/indocyanine green (ICG) co-loaded hybrid nanogels (designated as FIGs-LC). Based on the O2 redistribution and H2O2 activation by cascading LOx and CAT catalytic metabolic regulation, hydroxyl radical (·OH) and singlet oxygen (1O2) production can be modulated for glutathione (GSH)-activated chemodynamic therapy (CDT) and NIR-triggered photodynamic therapy (PDT), by manipulating the ratio of LOx and CAT to catalyze endogenous lactate to produce H2O2 and further cascade decomposing H2O2 into O2. The regulation reactions of FIGs-LC significantly elevate the intracellular ROS level and cause fatal damage to cancer cells inducing the effective inhibition of tumor growth. Such enzyme complex loaded hybrid nanogel present potential for biomedical ROS regulation, especially for the tumors with different redox state, size, and subcutaneous depth.


Assuntos
Antineoplásicos/farmacologia , Nanogéis/química , Peroxissomos/enzimologia , Fotoquimioterapia/métodos , Animais , Antineoplásicos/química , Catalase/química , Catalase/metabolismo , Catálise , Linhagem Celular Tumoral , Óxido Ferroso-Férrico/química , Glutationa/metabolismo , Humanos , Peróxido de Hidrogênio/metabolismo , Verde de Indocianina/química , Camundongos , Oxigenases de Função Mista/química , Oxigenases de Função Mista/metabolismo , Nanopartículas/química , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Oxigênio/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Microambiente Tumoral/efeitos dos fármacos
2.
Braz J Biol ; 83: e242942, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34468508

RESUMO

Thimerosal is an organomercurial compound, which is used in the preparation of intramuscular immunoglobulin, antivenoms, tattoo inks, skin test antigens, nasal products, ophthalmic drops, and vaccines as a preservative. In most of animal species and humans, the kidney is one of the main sites for mercurial compounds deposition and target organs for toxicity. So, the current research was intended to assess the thimerosal induced nephrotoxicity in male rats. Twenty-four adult male albino rats were categorized into four groups. The first group was a control group. Rats of Group-II, Group-III, and Group-IV were administered with 0.5µg/kg, 10µg/kg, and 50µg/kg of thimerosal once a day, respectively. Thimerosal administration significantly decreased the activities of catalase (CAT), superoxide dismutase (SOD), peroxidase (POD), glutathione reductase (GR), glutathione (GSH), and protein content while increased the thiobarbituric acid reactive substances (TBARS) and hydrogen peroxide (H2O2) levels dose-dependently. Blood urea nitrogen (BUN), creatinine, urobilinogen, urinary proteins, kidney injury molecule-1 (KIM-1), and neutrophil gelatinase-associated lipocalin (NGAL) levels were substantially increased. In contrast, urinary albumin and creatinine clearance was reduced dose-dependently in thimerosal treated groups. The results demonstrated that thimerosal significantly increased the inflammation indicators including nuclear factor kappaB (NF-κB), tumor necrosis factor-α (TNF-α), Interleukin-1ß (IL-1ß), Interleukin-6 (IL-6) levels and cyclooxygenase-2 (COX-2) activities, DNA and histopathological damages dose-dependently. So, the present findings ascertained that thimerosal exerted nephrotoxicity in male albino rats.


Assuntos
Estresse Oxidativo , Timerosal , Animais , Peróxido de Hidrogênio/metabolismo , Rim , Masculino , Ratos , Superóxido Dismutase/metabolismo , Timerosal/metabolismo , Timerosal/toxicidade
3.
Ecotoxicol Environ Saf ; 223: 112564, 2021 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-34340154

RESUMO

Chromium (Cr) disrupts the growth and physiology of plants. Selenium (Se) is considered as a promising option to help plants ameliorate Cr toxicity. To investigate the effects of exogenous Se on reactive oxygen species (ROS) burst and programmed cell death (PCD) in root tip cells under Cr stress, hydroponic experiments were carried out with Chinese cabbage seedlings grown in Hoagland solution containing 1 mg L-1 Cr and 0.1 mg L-1 Se. Results showed that Se scavenged the overproduction of H2O2 and O2-·, and alleviated the level of lipid peroxidation in root tips stressed by Cr. Moreover, Se effectively prevented DNA degradation and reduced the number of apoptotic cells in root tips. Compared with Cr treatment, Se supplementation reduced the content of ROS and malondialdehyde in mitochondria by 38.23% and 17.52%, respectively. Se application decreased the opening degree of mitochondrial permeability transition pores by 32.30%, increased mitochondrial membrane potential by 40.91%, alleviated the release of cyt c from mitochondria into cytosol by 18.42% and caused 57.40% decrease of caspase 3-like protease activity, and thus restored mitochondrial dysfunction caused by Cr stress. In addition, the alteration of Se on mitochondrial physiological properties maintained calcium homeostasis between mitochondria and cytosol, which further contributed to reducing the appearance of Cr-induced PCD. Findings suggested that Se restored mitochondrial dysfunction, which further rescued root tip cells from PCD, consequently activating defense strategies to protect plants from Cr toxicity and maintaining plant growth.


Assuntos
Brassica , Selênio , Apoptose , China , Cromo/metabolismo , Cromo/toxicidade , Peróxido de Hidrogênio/metabolismo , Peróxido de Hidrogênio/toxicidade , Meristema/metabolismo , Mitocôndrias , Selênio/metabolismo , Selênio/farmacologia
4.
Inorg Chem ; 60(17): 12984-12999, 2021 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-34369772

RESUMO

Three new classes of ionic organoselenium compounds containing cationic benzimidazolium and imidazolium ring systems with selenocyanates as counterions are described. The cyclization of N,N'-disubstituted benzimidazolium and imidazolium bromides having N-(CH2)2-Br and N-(CH2)3-Br groups in the presence of potassium selenocyanate (KSeCN) led to formation of the corresponding selenazolium selenocyanates (21a, 21b, 22a, and 22b) and selenazinium selenocyanates (21c, 21d, 22c, and 22d). However, the open-chain selenocyanates with additional selenocyanate counterions (21e, 21f, 22e, and 22f) were formed from the N,N'-disubstituted benzimidazolium and imidazolium bromides having N-(CH2)6-Br groups. Mechanistic studies were carried out to understand the feasibility of such cyclization processes in the presence of KSeCN. The compounds were studied further for their potencies to catalytically reduce H2O2 in the presence of thiols. Interestingly, the cyclic selenazolium (21a, 21b, 22a, and 22b) and selenazinium compounds (21c, 21d, 22c, and 22d) exhibited significantly higher antioxidant activities than the corresponding acyclic selenocyanates (21f, 22e, and 22f). Selected compounds (22d and 22e) were further evaluated for their potencies in modulating the intracellular level of reactive oxygen species (ROS) in a representative macrophage cell line (RAW 264.7). Owing to the cationic nature of compounds, they may target and scavenge mitochondrial ROS in the cellular medium.


Assuntos
Antioxidantes/farmacologia , Benzimidazóis/farmacologia , Compostos Organosselênicos/farmacologia , Animais , Antioxidantes/síntese química , Benzimidazóis/síntese química , Cianatos/síntese química , Cianatos/farmacologia , Ciclização , Peróxido de Hidrogênio/química , Peróxido de Hidrogênio/metabolismo , Camundongos , Compostos Organosselênicos/síntese química , Oxirredução , Células RAW 264.7 , Compostos de Selênio/síntese química , Compostos de Selênio/farmacologia
5.
Int J Mol Sci ; 22(15)2021 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-34361070

RESUMO

In cancer therapy, radioresistance or chemoresistance cells are major problems. We established clinically relevant radioresistant (CRR) cells that can survive over 30 days after 2 Gy/day X-ray exposures. These cells also show resistance to anticancer agents and hydrogen peroxide (H2O2). We have previously demonstrated that all the CRR cells examined had up-regulated miR-7-5p and after miR-7-5p knockdown, they lost radioresistance. However, the mechanism of losing radioresistance remains to be elucidated. Therefore, we investigated the role of miR-7-5p in radioresistance by knockdown of miR-7-5p using CRR cells. As a result, knockdown of miR-7-5p increased reactive oxygen species (ROS), mitochondrial membrane potential, and intracellular Fe2+ amount. Furthermore, miR-7-5p knockdown results in the down-regulation of the iron storage gene expression such as ferritin, up-regulation of the ferroptosis marker ALOX12 gene expression, and increases of Liperfluo amount. H2O2 treatment after ALOX12 overexpression led to the enhancement of intracellular H2O2 amount and lipid peroxidation. By contrast, miR-7-5p knockdown seemed not to be involved in COX-2 and glycolysis signaling but affected the morphology of CRR cells. These results indicate that miR-7-5p control radioresistance via ROS generation that leads to ferroptosis.


Assuntos
Ferroptose , Regulação Neoplásica da Expressão Gênica , MicroRNAs/genética , Neoplasias Bucais/patologia , Tolerância a Radiação , Espécies Reativas de Oxigênio/metabolismo , Araquidonato 12-Lipoxigenase/metabolismo , Células HeLa , Humanos , Peróxido de Hidrogênio/metabolismo , Potencial da Membrana Mitocondrial , Neoplasias Bucais/genética , Neoplasias Bucais/radioterapia , Transdução de Sinais , Células Tumorais Cultivadas
6.
Free Radic Biol Med ; 174: 135-143, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34363947

RESUMO

Aquaporin-8 (AQP8) is a peroxiporin, a transmembrane water and hydrogen peroxide (H2O2) transport protein expressed in the mitochondrial and plasma membranes of pancreatic ß-cells. AQP8 protein expression is low under physiological conditions, but it increases after cytokine exposure both, in vitro and in vivo, possibly related to a NF-κB consensus sequence in the promoter. AQP8 knockdown (KD) insulin-producing RINm5F cells are particularly susceptible to cytokine-mediated oxidative stress. Cytokine (a mixture of IL-1ß, TNF-α, and IFN-γ) treated AQP8 KD cells exhibited pronounced sensitivity to reactive oxygen and nitrogen species (ROS and RNS), resulting in a significant loss of ß-cell viability due to enhanced toxicity of the increased concentrations of H2O2 and hydroxyl radicals (●OH) in mitochondria of AQP8 KD cells. This viability loss went along with increased caspase activities, reduced nitrite concentration (representative of nitric oxide (NO●) accumulation) and increased lipid peroxidation. The explanation for the increased toxicity of the proinflammatory cytokines in AQP8 KD cells resides in the fact that efflux of the H2O2 generated during oxidative stress in the ß-cell mitochondria is hampered through the loss of the peroxiporin channels in the mitochondrial membranes of the AQP8 KD cells. The increased proinflammatory cytokine toxicity due to loss of AQP8 expression in the KD ß-cell mitochondria is thus the result of increased rates of apoptosis. This decreased cell viability is caused by increased levels of oxidative stress along with a ferroptosis-mediated cell death component due to decreased NO● generation.


Assuntos
Aquaporinas , Células Secretoras de Insulina , Animais , Citocinas/genética , Peróxido de Hidrogênio/metabolismo , Peróxido de Hidrogênio/toxicidade , Insulina/metabolismo , Células Secretoras de Insulina/metabolismo , Ratos
7.
Int J Mol Sci ; 22(14)2021 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-34299239

RESUMO

Estrogens are steroid hormones that play a crucial role in the regulation of the reproductive and non-reproductive system physiology. Among non-reproductive systems, the nervous system is mainly affected by estrogens due to their antioxidant, anti-apoptotic, and anti-inflammatory activities, which are mediated by membranous and nuclear estrogen receptors, and also by non-estrogen receptor-associated estrogen actions. Neuronal viability and functionality are also associated with the maintenance of mitochondrial functions. Recently, the localization of estrogen receptors, especially estrogen receptor beta, in the mitochondria of many types of neuronal cells is documented, indicating the direct involvement of the mitochondrial estrogen receptor beta (mtERß) in the maintenance of neuronal physiology. In this study, cell lines of N2A cells stably overexpressing a mitochondrial-targeted estrogen receptor beta were generated and further analyzed to study the direct involvement of mtERß in estrogen neuroprotective antioxidant and anti-apoptotic actions. Results from this study revealed that the presence of estrogen receptor beta in mitochondria render N2A cells more resistant to staurosporine- and H2O2-induced apoptotic stimuli, as indicated by the reduced activation of caspase-9 and -3, the increased cell viability, the increased ATP production, and the increased resistance to mitochondrial impairment in the presence or absence of 17-ß estradiol (E2). Thus, the direct involvement of mtERß in antioxidant and anti-apoptotic activities is documented, rendering mtERß a promising therapeutic target for mitochondrial dysfunction-associated degenerative diseases.


Assuntos
Receptor beta de Estrogênio/metabolismo , Mitocôndrias/metabolismo , Neuroblastoma/metabolismo , Animais , Antioxidantes/metabolismo , Apoptose/efeitos dos fármacos , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Estradiol/farmacologia , Receptor beta de Estrogênio/genética , Estrogênios/metabolismo , Estrogênios/farmacologia , Peróxido de Hidrogênio/metabolismo , Camundongos , Mitocôndrias/fisiologia , Células-Tronco Neurais/metabolismo , Neuroblastoma/genética , Neurônios/metabolismo , Neurônios/fisiologia , Neuroproteção/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Receptores de Estrogênio/metabolismo
8.
Nan Fang Yi Ke Da Xue Xue Bao ; 41(6): 953-959, 2021 Jun 20.
Artigo em Chinês | MEDLINE | ID: mdl-34238751

RESUMO

OBJECTIVE: To investigate the apoptosis- inducing effect of fucoxanthin in human prostate cancer PC-3 cells and the underlying mechanism. OBJECTIVE: The viability and apoptosis of PC-3 cells treated with fucoxanthin were analyzed using commercial kits, and the mitochondrial membrane potential, mitochondrial morphology and mitochondrial superoxide were detected using fluorescence probe staining. The contents of ATP, H2O2, malondialdehyde (MDA), superoxide and the total antioxidant capacity of PC-3 cells were determined. The protein expressions of Bcl-2, Bax and cytochrome c were detected with Western blotting, and the activity of caspase-9 and caspase- 3/7 was detected using corresponding kits. OBJECTIVE: Fucoxanthin significantly inhibited the viability of PC-3 cells in a time- and dose-dependent manner, and dose-dependently induced apoptosis of the cells (P < 0.05). Fucoxanthin-treated PC-3 cells showed significantly decreased mitochondrial membrane potential, mitochondrial fragmentation and increased superoxide level in the mitochondria (P < 0.05), and these effects of fucoxanthin were dose- dependent. Fucoxanthin dose-dependently decreased ATP level and the total antioxidant capacity of PC-3 cells, increased the contents of H2O2, MDA and superoxide (all P < 0.05), enhanced the protein expressions of Bax and cytochrome c in the cytoplasm, and lowered the protein expressions of Bcl-2 and cytochromes in the mitochondria (P < 0.05). OBJECTIVE: Fucoxanthin induces apoptosis of PC-3 cells by triggering mitochondrial dysfunction to cause oxidative stress and by activating mitochondria-mediated apoptotic signaling pathways, suggesting its potential in prostate cancer treatment.


Assuntos
Peróxido de Hidrogênio , Neoplasias da Próstata , Apoptose , Humanos , Peróxido de Hidrogênio/metabolismo , Masculino , Potencial da Membrana Mitocondrial , Mitocôndrias/metabolismo , Estresse Oxidativo , Células PC-3 , Neoplasias da Próstata/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Xantofilas , Proteína X Associada a bcl-2/metabolismo
9.
J Dairy Sci ; 104(9): 9532-9542, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34218913

RESUMO

Ionizing radiation (IR) is widely used in the diagnosis and treatment of various cancers. However, IR can cause damage to human health by producing reactive oxygen species. Lactococcus lactis is a type of microorganism that is beneficial to human health and has a strong antioxidant capacity. In this study, the protective effect of normal and IR-induced L. lactis IL1403 cell-free extracts (CFE and IR-CFE, respectively) against oxidative damage in vitro and the radioprotective effect of IR-CFE in vivo was evaluated using 60Coγ-induced oxidative damage model in mice. Results showed that IR-CFE exhibited a stronger oxidative damage-protective effect than CFE for L. lactis IL1403 under H2O2 in vitro. Moreover, IR-CFE also showed strong radioprotective effect on hepatocyte cells (AML-12) under radiation condition, and the effect was better than that of CFE. Animal experiment indicated that IR-CFE could reduce the IR-induced damage to the hematopoietic system by increasing the number of white blood cells and red blood cells in peripheral blood of irradiated mice. It was also observed that IR-CFE could markedly alleviate the 60Coγ-induced oxidative stress via increasing the activities of superoxide dismutase and glutathione peroxidase, enhancing the levels of glutathione, and decreasing the contents of malondialdehyde in serum, liver, and spleen. In addition, IR-CFE also could reduce the activities of alanine transaminase and aspartate aminotransferase in serum, thereby reducing radiation damage to the liver. These results suggested that IR-CFE could be considered as potential candidates for natural radioprotective agents. This study provides a theoretical basis for improving the application of lactic acid bacteria.


Assuntos
Lactococcus lactis , Protetores contra Radiação , Animais , Antioxidantes/metabolismo , Extratos Celulares , Peróxido de Hidrogênio/metabolismo , Fígado/metabolismo , Camundongos , Estresse Oxidativo
10.
Free Radic Biol Med ; 172: 675-687, 2021 08 20.
Artigo em Inglês | MEDLINE | ID: mdl-34289395

RESUMO

Steroids and insulin-like growth factors (Igfs) are indispensable for folliculogenesis and reproductive fitness in the vertebrate ovary. The intrafollicular redox balance is also of immense importance for ovarian follicles wherein low levels of ROS are being utilized for cell signalling and regulation of gene expression; its excess may interfere with normal physiological processes leading to ovotoxicity. However, the functional relevance of ovarian steroidogenesis in maintaining the follicular microenvironment with coordinated redox homeostasis and intra-ovarian growth factors axis is relatively less understood. Using zebrafish full-grown (FG) ovarian follicles in vitro, our study shows that blocking steroid biosynthesis with anti-steroidal drugs, DL-aminoglutethimide (AG) or Trilostane (Trilo), prevents hCG (LH analogue)-induced StAR expression concomitant with a robust increase in intrafollicular ROS levels. Congruent with heightened intracellular levels of superoxide anions (O2•-) and hydrogen peroxide (H2O2), priming with AG or Trilo abrogates the transcript abundance of major antioxidant enzyme genes (SOD1, SOD2, and CAT) in hCG-stimulated follicles. Significantly, blocking steroidogenesis attenuates transcript abundance of HSP70 but elevates NOX4 expression potentially through ERα-mediated pathway. Importantly, disrupted redox balance in AG/Trilo pre-incubated FG follicles negatively impacts hCG-mediated activation of PKA/CREB signaling and transcriptional activation of igf ligands. Elevated ROS attenuation of antioxidant defense parameters and impaired endocrine and autocrine/paracrine homeostasis converge upon reduced p34cdc2 (Thr-161) phosphorylation, a reliable marker for MPF activation, and resumption of meiotic G2-M1 transition in hCG-treated follicles. Collectively, altered redox homeostasis in steroid-depleted follicles has a significant negative influence on GTH (LH) regulation of follicular events, specifically Igf synthesis, meiotic maturational competence and ovarian fitness.


Assuntos
Somatomedinas , Peixe-Zebra , Animais , Feminino , Homeostase , Peróxido de Hidrogênio/metabolismo , Oócitos/metabolismo , Oxirredução , Somatomedinas/metabolismo , Esteroides , Peixe-Zebra/metabolismo
11.
Biomolecules ; 11(6)2021 06 16.
Artigo em Inglês | MEDLINE | ID: mdl-34208749

RESUMO

Since the first description of hydrogen sulfide (H2S) as a toxic gas in 1713 by Bernardino Ramazzini, most studies on H2S have concentrated on its toxicity. In 1989, Warenycia et al. demonstrated the existence of endogenous H2S in the brain, suggesting that H2S may have physiological roles. In 1996, we demonstrated that hydrogen sulfide (H2S) is a potential signaling molecule, which can be produced by cystathionine ß-synthase (CBS) to modify neurotransmission in the brain. Subsequently, we showed that H2S relaxes vascular smooth muscle in synergy with nitric oxide (NO) and that cystathionine γ-lyase (CSE) is another producing enzyme. This study also opened up a new research area of a crosstalk between H2S and NO. The cytoprotective effect, anti-inflammatory activity, energy formation, and oxygen sensing by H2S have been subsequently demonstrated. Two additional pathways for the production of H2S with 3-mercaptopyruvate sulfurtransferase (3MST) from l- and d-cysteine have been identified. We also discovered that hydrogen polysulfides (H2Sn, n ≥ 2) are potential signaling molecules produced by 3MST. H2Sn regulate the activity of ion channels and enzymes, as well as even the growth of tumors. S-Sulfuration (S-sulfhydration) proposed by Snyder is the main mechanism for H2S/H2Sn underlying regulation of the activity of target proteins. This mini review focuses on the key findings on H2S/H2Sn signaling during the first 25 years.


Assuntos
Sulfeto de Hidrogênio/química , Sulfeto de Hidrogênio/metabolismo , Sulfetos/metabolismo , Animais , Encéfalo/metabolismo , Cistationina gama-Liase/metabolismo , Cisteína/metabolismo , Humanos , Peróxido de Hidrogênio/metabolismo , Canais Iônicos , Óxido Nítrico/metabolismo , Transdução de Sinais/fisiologia , Sulfetos/química , Transmissão Sináptica
12.
Methods Mol Biol ; 2342: 257-284, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34272698

RESUMO

Aldehyde oxidase (AO) has emerged as an important drug metabolizing enzyme over the last decade. Several compounds have failed in the clinic because the clearance or toxicity was underestimated by preclinical species. Human AO is much more active than rodent AO, and dogs do not have functional AO. Metabolic products from AO-catalyzed oxidation are generally nonreactive and often they have much lower solubility. AO metabolism is not limited to oxidation as AO can also catalyze reduction of oxygen and nitrite. Reduction of oxygen leads to the reactive oxygen species (ROS) superoxide radical anion and hydrogen peroxide. Reduction of nitrite leads to the formation of nitric oxide with potential pharmacological implications. AO is also reported to catalyze the reductive metabolism of nitro-compounds, N-oxides, sulfoxides, isoxazoles, isothiazoles, nitrite, and hydroxamic acids. These reductive transformations may cause toxicity due to the formation of reactive metabolites. Moreover, the inhibition kinetics are complex, and multiple probe substrates should be used when assessing the potential for DDIs. Finally, AO appears to be amenable to computational predictions of both regioselectivity and rates of reaction, which holds promise for virtual screening.


Assuntos
Aldeído Oxidase/química , Aldeído Oxidase/metabolismo , Inibidores Enzimáticos/química , Aldeído Oxidase/antagonistas & inibidores , Animais , Catálise , Cães , Desenho de Fármacos , Inibidores Enzimáticos/farmacocinética , Humanos , Peróxido de Hidrogênio/metabolismo , Modelos Moleculares , Oxirredução , Conformação Proteica , Relação Estrutura-Atividade , Superóxidos/metabolismo
13.
Free Radic Biol Med ; 173: 1-6, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34273538

RESUMO

Obesity has been associated with increased production of reactive oxygen species (ROS), which may be involved in the development of cardiovascular disease and type 2 diabetes (T2D). Endurance exercise lowers ROS production and increases antioxidant capacity in muscle cells, but it is currently unknown whether high intensity interval training (HIT) elicits the same effects. Twelve sedentary obese subjects at risk of developing T2D took part in a six-week intervention, performing three HIT sessions per week (five 1-min sets of high-intensity cycling (125% of VO2peak), with 90 s recovery in between sets). Muscle biopsies were obtained for assessment of ROS production (H2O2 emission), mitochondrial respiratory capacity, and antioxidant protein levels before and after the intervention. H2O2 emission decreased 60.4% after the intervention (Succinate 3 mmolï½¥l-1), concurrent with a 35.1% increase in protein levels of the antioxidant manganese superoxide dismutase (MnSOD) and a trend towards increased levels of the antioxidant catalase (p = 0.06, 72.9%). These findings were accompanied by a 19% increased mitochondrial respiratory capacity (CI + II), a 6.9% increased VO2peak and a 1.7% lower body fat percentage. These effects were achieved after just 15 min of high-intensity work and 40 min of total time spent per week. Overall, this suggests that a relatively small amount of HIT is sufficient to induce beneficial effects on ROS production and antioxidant status in muscle cells, which may lower oxidative stress and potentially protect against the development of cardiovascular disease.


Assuntos
Antioxidantes , Diabetes Mellitus Tipo 2 , Adulto , Antioxidantes/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Humanos , Peróxido de Hidrogênio/metabolismo , Músculo Esquelético/metabolismo , Obesidade/metabolismo , Estresse Oxidativo , Fatores de Risco
14.
Mol Oral Microbiol ; 36(5): 267-277, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34314577

RESUMO

Streptococcal pyruvate oxidase (SpxB) is a hydrogen peroxide-generating enzyme and plays a critical role in Streptococcus sanguinis interspecies interactions, but less is known about its biochemistry. We examined SpxB subcellular localization using protein fractionation and microscopy and found SpxB to be primarily cytoplasmic, but a small portion is also membrane associated. Potential post-translational modifications of SpxB were determined using coimmunoprecipitation and mass spectrometry. Two mutant strains were constructed to further validate the presence of predicted site-specific post-translational modifications. These site mutated SpxB proteins exhibited reduced solubility in vivo, which likely contributes to the observed phenotypic changes in colony morphology, bacterial growth, and H2 O2 production. Overall, our data suggest that SpxB post-translational modifications likely play a major role to regulate SpxB function in S. sanguinis.


Assuntos
Piruvato Oxidase , Streptococcus sanguis , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Peróxido de Hidrogênio/metabolismo , Processamento de Proteína Pós-Traducional , Piruvato Oxidase/genética , Piruvato Oxidase/metabolismo , Solubilidade , Streptococcus/genética , Streptococcus/metabolismo , Streptococcus sanguis/genética , Streptococcus sanguis/metabolismo
15.
BMC Plant Biol ; 21(1): 326, 2021 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-34229625

RESUMO

BACKGROUND: Glycolate oxidase (GLO) is not only a key enzyme in photorespiration but also a major engine for H2O2 production in plants. Catalase (CAT)-dependent H2O2 decomposition has been previously reported to be involved in the regulation of IAA biosynthesis. However, it is still not known which mechanism contributed to the H2O2 production in IAA regulation. RESULTS: In this study, we found that in glo mutants of rice, as H2O2 levels decreased IAA contents significantly increased, whereas high CO2 abolished the difference in H2O2 and IAA contents between glo mutants and WT. Further analyses showed that tryptophan (Trp, the precursor for IAA biosynthesis in the Trp-dependent biosynthetic pathway) also accumulated due to increased tryptophan synthetase ß (TSB) activity. Moreover, expression of the genes involved in Trp-dependent IAA biosynthesis and IBA to IAA conversion were correspondingly up-regulated, further implicating that both pathways contribute to IAA biosynthesis as mediated by the GLO-dependent production of H2O2. CONCLUSION: We investigated the function of GLO in IAA signaling in different levels from transcription, enzyme activities to metabolic levels. The results suggest that GLO-dependent H2O2 signaling, essentially via photorespiration, confers regulation over IAA biosynthesis in rice plants.


Assuntos
Oxirredutases do Álcool/metabolismo , Peróxido de Hidrogênio/metabolismo , Ácidos Indolacéticos/metabolismo , Oryza/enzimologia , Oxirredutases do Álcool/genética , Vias Biossintéticas/efeitos da radiação , Respiração Celular/efeitos da radiação , Regulação da Expressão Gênica de Plantas/efeitos da radiação , Luz , Modelos Biológicos , Mutação/genética , Oryza/genética , Oryza/efeitos da radiação , Peroxissomos/metabolismo , Peroxissomos/efeitos da radiação , Fenótipo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Triptofano/metabolismo
16.
Int J Mol Sci ; 22(9)2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-34062819

RESUMO

An oxidative burst is an early response of plants to various biotic/abiotic stresses. In plant-microbe interactions, the plant body can induce oxidative burst to activate various defense mechanisms to combat phytopathogens. A localized oxidative burst is also one of the typical behaviors during hypersensitive response (HR) caused by gene-for-gene interaction. In this study, the occurrence of oxidative burst and its signaling pathways was studied from different levels of disease severity (i.e., susceptible, intermediate, and resistant) in the B. napus-L. maculans pathosystem. Canola cotyledons with distinct levels of resistance exhibited differential regulation of the genes involved in reactive oxygen species (ROS) accumulation and responses. Histochemical assays were carried out to understand the patterns of H2O2 accumulation and cell death. Intermediate and resistant genotypes exhibited earlier accumulation of H2O2 and emergence of cell death around the inoculation origins. The observations also suggested that the cotyledons with stronger resistance were able to form a protective region of intensive oxidative bursts between the areas with and without hyphal intrusions to block further fungal advancement to the uninfected regions. The qPCR analysis suggested that different onset patterns of some marker genes in ROS accumulation/programmed cell death (PCD) such as RBOHD, MPK3 were associated with distinct levels of resistance from B. napus cultivars against L. maculans. The observations and datasets from this article indicated the distinct differences in ROS-related cellular behaviors and signaling between compatible and incompatible interactions.


Assuntos
Cotilédone/genética , Resistência à Doença/genética , Doenças das Plantas/genética , Explosão Respiratória/genética , Brassica napus/genética , Brassica napus/parasitologia , Morte Celular/genética , Cotilédone/parasitologia , Epistasia Genética , Genótipo , Peróxido de Hidrogênio/metabolismo , Leptosphaeria/genética , Leptosphaeria/patogenicidade , Doenças das Plantas/parasitologia , Proteínas de Plantas/genética , Transdução de Sinais/genética , Estresse Fisiológico/genética
17.
Int J Mol Sci ; 22(9)2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-34062832

RESUMO

To the present day, no efficient plant protection method against economically important bacterial phytopathogens from the Pectobacteriaceae family has been implemented into agricultural practice. In this view, we have performed a multivariate optimization of the operating parameters of the reaction-discharge system, employing direct current atmospheric pressure glow discharge, generated in contact with a flowing liquid cathode (FLC-dc-APGD), for the production of a plasma-activated liquid (PAL) of defined physicochemical and anti-phytopathogenic properties. As a result, the effect of the operating parameters on the conductivity of PAL acquired under these conditions was assessed. The revealed optimal operating conditions, under which the PAL of the highest conductivity was obtained, were as follows: flow rate of the solution equaled 2.0 mL min-1, the discharge current was 30 mA, and the inorganic salt concentration (ammonium nitrate, NH4NO3) in the solution turned out to be 0.50% (m/w). The developed PAL exhibited bacteriostatic and bactericidal properties toward Dickeya solani IFB0099 and Pectobacterium atrosepticum IFB5103 strains, with minimal inhibitory and minimal bactericidal concentrations equaling 25%. After 24 h exposure to 25% PAL, 100% (1-2 × 106) of D. solani and P. atrosepticum cells lost viability. We attributed the antibacterial properties of PAL to the presence of deeply penetrating, reactive oxygen and nitrogen species (RONS), which were, in this case, OH, O, O3, H2O2, HO2, NH, N2, N2+, NO2-, NO3-, and NH4+. Putatively, the generated low-cost, eco-friendly, easy-to-store, and transport PAL, exhibiting the required antibacterial and physicochemical properties, may find numerous applications in the plant protection sector.


Assuntos
Antibacterianos/farmacologia , Flores/crescimento & desenvolvimento , Pectobacterium/metabolismo , Espécies Reativas de Nitrogênio/metabolismo , Agricultura , Antibacterianos/química , Pressão Atmosférica , Líquidos Corporais/química , Flores/efeitos da radiação , Peróxido de Hidrogênio/metabolismo , Nitratos/farmacologia , Pectobacterium/crescimento & desenvolvimento , Pectobacterium/efeitos da radiação , Gases em Plasma/farmacologia , Espécies Reativas de Oxigênio/química
18.
Nat Commun ; 12(1): 3393, 2021 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-34099712

RESUMO

The iron gall ink-triggered chemical corrosion of hand-written documents is a big threat to Western cultural heritages, which was demonstrated to result from the iron gall (GA-Fe) chelate-promoted reactive oxygen species generation. Such a phenomenon has inspired us to apply the pro-oxidative mechanism of GA-Fe to anticancer therapy. In this work, we construct a composite cancer nanomedicine by loading gallate into a Fe-engineered mesoporous silica nanocarrier, which can degrade in acidic tumor to release the doped Fe3+ and the loaded gallate, forming GA-Fe nanocomplex in situ. The nanocomplex with a highly reductive ligand field can promote oxygen reduction reactions generating hydrogen peroxide. Moreover, the resultant two-electron oxidation form of GA-Fe is an excellent Fenton-like agent that can catalyze hydrogen peroxide decomposition into hydroxyl radical, finally triggering severe oxidative damage to tumors. Such a therapeutic approach by intratumoral synthesis of GA-Fe nano-metalchelate may be instructive to future anticancer researches.


Assuntos
Antineoplásicos/administração & dosagem , Ácido Gálico/administração & dosagem , Ferro/administração & dosagem , Nanopartículas Metálicas/administração & dosagem , Neoplasias/tratamento farmacológico , Animais , Antineoplásicos/química , Antineoplásicos/metabolismo , Catálise , Complexos de Coordenação/administração & dosagem , Complexos de Coordenação/química , Complexos de Coordenação/metabolismo , Portadores de Fármacos/química , Feminino , Ácido Gálico/química , Ácido Gálico/metabolismo , Células HeLa , Células Endoteliais da Veia Umbilical Humana , Humanos , Peróxido de Hidrogênio/química , Peróxido de Hidrogênio/metabolismo , Concentração de Íons de Hidrogênio , Radical Hidroxila/química , Radical Hidroxila/metabolismo , Injeções Intravenosas , Ferro/química , Ferro/metabolismo , Ligantes , Nanopartículas Metálicas/química , Camundongos , Neoplasias/patologia , Oxirredução , Oxigênio/metabolismo , Dióxido de Silício/química , Ensaios Antitumorais Modelo de Xenoenxerto
19.
Molecules ; 26(10)2021 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-34069787

RESUMO

We evaluated photosystem II (PSII) functionality in potato plants (Solanum tuberosum L.) before and after a 15 min feeding by the leaf miner Tuta absoluta using chlorophyll a fluorescence imaging analysis combined with reactive oxygen species (ROS) detection. Fifteen minutes after feeding, we observed at the feeding zone and at the whole leaf a decrease in the effective quantum yield of photosystem II (PSII) photochemistry (ΦPSII). While at the feeding zone the quantum yield of regulated non-photochemical energy loss in PSII (ΦNPQ) did not change, at the whole leaf level there was a significant increase. As a result, at the feeding zone a significant increase in the quantum yield of non-regulated energy loss in PSII (ΦNO) occurred, but there was no change at the whole leaf level compared to that before feeding, indicating no change in singlet oxygen (1O2) formation. The decreased ΦPSII after feeding was due to a decreased fraction of open reaction centers (qp), since the efficiency of open PSII reaction centers to utilize the light energy (Fv'/Fm') did not differ before and after feeding. The decreased fraction of open reaction centers resulted in increased excess excitation energy (EXC) at the feeding zone and at the whole leaf level, while hydrogen peroxide (H2O2) production was detected only at the feeding zone. Although the whole leaf PSII efficiency decreased compared to that before feeding, the maximum efficiency of PSII photochemistry (Fv/Fm), and the efficiency of the water-splitting complex on the donor side of PSII (Fv/Fo), did not differ to that before feeding, thus they cannot be considered as sensitive parameters to monitor biotic stress effects. Chlorophyll fluorescence imaging analysis proved to be a good indicator to monitor even short-term impacts of insect herbivory on photosynthetic function, and among the studied parameters, the reduction status of the plastoquinone pool (qp) was the most sensitive and suitable indicator to probe photosynthetic function under biotic stress.


Assuntos
Enterobius/fisiologia , Luz , Complexo de Proteína do Fotossistema II/metabolismo , Folhas de Planta/parasitologia , Folhas de Planta/efeitos da radiação , Espécies Reativas de Oxigênio/metabolismo , Solanum tuberosum/parasitologia , Solanum tuberosum/efeitos da radiação , Animais , Transporte de Elétrons , Comportamento Alimentar , Peróxido de Hidrogênio/metabolismo , Teoria Quântica
20.
Biochimie ; 188: 45-51, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34087390

RESUMO

Aquaporins (AQPs) are transmembrane water channels and some of them are permeable in addition to water to other small solutes including hydrogen peroxide. The sperm cells of mammals and fishes express different AQPs, although there is no agreement in the literature on their localization. In humans, AQP3 and AQP11 are expressed mainly in the tail, AQP7 in the head and AQP8 in the midpiece. Thanks to the results of experiments with KO mice and to data obtained by comparing sub-fertile patients with normospermic subjects, the importance of AQPs for the normal functioning of sperms to ensure normal fertility emerged. AQP3, AQP7 and AQP11 appeared involved in the sperm volume regulation, a key role for fertility because osmoadaptation protect the sperm against a swelling and tail bending that could affect sperm motility. AQP8 seems to have a fundamental role in regulating the elimination of hydrogen peroxide, the most abundant reactive oxygen species (ROS), and therefore in the response to oxidative stress. In this review, the human AQPs expression, their localization and functions, as well as their relevance in normal fertility are discussed. To understand better the AQPs role in human sperm functionality, the results of studies obtained in other animal species were also considered.


Assuntos
Aquaporinas/fisiologia , Peróxido de Hidrogênio/metabolismo , Espermatozoides/fisiologia , Água/metabolismo , Animais , Aquaporinas/classificação , Humanos , Masculino , Estresse Oxidativo , Motilidade Espermática , Espermatozoides/citologia
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