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1.
J Toxicol Sci ; 45(9): 569-579, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32879256

RESUMO

Indoxyl, a derivative of indole originating from tryptophan, may undergo phase-II sulfate-conjugation pathway, thereby forming indoxyl sulfate (IS) in vivo. We previously reported that IS, a well-known uremic toxin, can increase the intracellular oxidation level and decrease the phagocytic activity in a differentiated HL-60 human macrophage cell model. Using the same cell model, the current study aimed to investigate whether indole and indoxyl (the metabolic precursors of indoxyl and IS, respectively) may cause macrophage immune dysfunction. Results obtained indicated that intracellular oxidation level and cytotoxicity markedly increased upon treatment with indole and indoxyl, in comparison with IS. Incubation of the cells with indole and indoxyl also resulted in attenuated phagocytic activity. Human serum albumin (HSA)-binding assay confirmed that tryptophan and IS, but not indole and indoxyl, could selectively bind to the site II in HSA. Collectively, the results indicated that indole and indoxyl may strongly down-regulate the phagocytic immune function of macrophages, whereas IS, formed upon sulfate conjugation of indoxyl, may exhibit enhanced HSA-binding capability, thereby reducing the adverse effects of indoxyl.


Assuntos
Indóis/efeitos adversos , Macrófagos/imunologia , Macrófagos/metabolismo , Oxirredução/efeitos dos fármacos , Fagocitose/efeitos dos fármacos , Fagocitose/imunologia , Diferenciação Celular/efeitos dos fármacos , Células Cultivadas , Células HL-60 , Humanos , Indicã/metabolismo , Macrófagos/efeitos dos fármacos , Ligação Proteica , Albumina Sérica/metabolismo , Triptofano/metabolismo
2.
Anticancer Res ; 40(9): 4843-4856, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32878772

RESUMO

Aberrant fatty acid (FA) metabolism has long been recognized in colorectal cancer (CRC) cells. Since de novo lipogenesis is required for CRC tumour growth and survival, the inhibition of FA metabolism is a promising potential therapeutic target. Inhibition of the opposite process, ß-oxidation of FAs, has also showed promising results in many CRC models. For patients with CRC, both FA synthesis and ß-oxidation inhibitors are promising potential therapeutic options as monotherapies or as combination therapies with other anticancer agents. In this review, we discuss recent reports concerning inhibitors of FA synthesis and ß-oxidation in various CRC models. The exact mechanisms of action of the selected compounds described in this review remain unknown and require precise evaluation before the development of new successful therapies for CRC is possible.


Assuntos
Antineoplásicos/farmacologia , Neoplasias Colorretais/metabolismo , Inibidores Enzimáticos/farmacologia , Ácidos Graxos/metabolismo , Antineoplásicos/uso terapêutico , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Neoplasias Colorretais/tratamento farmacológico , Inibidores Enzimáticos/uso terapêutico , Humanos , Metabolismo dos Lipídeos/efeitos dos fármacos , Oxirredução/efeitos dos fármacos
3.
Chem Biol Interact ; 330: 109234, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32860823

RESUMO

Cisplatin is an antineoplastic drug well recognized for its success in the battle against several types of cancer in adult, juvenile, and child populations. Meanwhile, this drug is also famous due to its serious side effects, such as hepatotoxicity. This study evaluated the hepatoprotective effectiveness of Diphenyl Diselenide (PhSe)2 and Ebselen in a model of cisplatin-induced toxicity in juvenile rats. Juvenile Wistar rats received a single intraperitoneal (i.p) injection of cisplatin (6 mg/kg) or saline solution, at postnatal day (PND) 21. Ebselen (11 mg/kg) or (PhSe)2 (12 mg/kg) was intragastrically (i.g) administered in rats from PND 21 to PND 25. At PND 26, the blood and liver were collected for the biochemistry assays. A single administration of cisplatin was enough to alter the makers of hepatic function (an increase of AST activity) and the blood lipid profile (an increase of cholesterol and triglycerides, TG). The cisplatin-induced metabolic disruption was demonstrated by the increase of hepatic glycogen and TG contents and hexokinase, glucose-6-phosphatase, and tyrosine aminotransferase activities; a decrease of citrate synthase activity and the levels of GLUT-2. Cisplatin-induced hepatic oxidative stress was characterized by an increase in reactive oxygen species, TBARS, protein carbonyl, and Nox levels as well as the decrease in NPSH levels. Ebselen and (PhSe)2 were effective against all alterations caused by this chemotherapy medication. The present findings highlight the (PhSe)2 and Ebselen similar hepatoprotective effectiveness against cisplatin-induced disruption of metabolic homeostasis and redox balance in juvenile rats.


Assuntos
Azóis/farmacologia , Derivados de Benzeno/farmacologia , Cisplatino/toxicidade , Homeostase/efeitos dos fármacos , Fígado/efeitos dos fármacos , Compostos Organosselênicos/farmacologia , Substâncias Protetoras/farmacologia , Animais , Lipídeos/sangue , Fígado/metabolismo , Oxirredução/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Ratos
4.
Nat Commun ; 11(1): 3881, 2020 08 04.
Artigo em Inglês | MEDLINE | ID: mdl-32753572

RESUMO

Cells typically respond to chemical or physical perturbations via complex signaling cascades which can simultaneously affect multiple physiological parameters, such as membrane voltage, calcium, pH, and redox potential. Protein-based fluorescent sensors can report many of these parameters, but spectral overlap prevents more than ~4 modalities from being recorded in parallel. Here we introduce the technique, MOSAIC, Multiplexed Optical Sensors in Arrayed Islands of Cells, where patterning of fluorescent sensor-encoding lentiviral vectors with a microarray printer enables parallel recording of multiple modalities. We demonstrate simultaneous recordings from 20 sensors in parallel in human embryonic kidney (HEK293) cells and in human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs), and we describe responses to metabolic and pharmacological perturbations. Together, these results show that MOSAIC can provide rich multi-modal data on complex physiological responses in multiple cell types.


Assuntos
Técnicas Biossensoriais/métodos , Células-Tronco Pluripotentes Induzidas/metabolismo , Microscopia de Fluorescência/métodos , Miócitos Cardíacos/metabolismo , Imagem Óptica/métodos , Potenciais de Ação/efeitos dos fármacos , Antagonistas Adrenérgicos beta/farmacologia , Técnicas Biossensoriais/instrumentação , Cálcio/química , Proteínas de Fluorescência Verde/metabolismo , Células HEK293 , Humanos , Peróxido de Hidrogênio/farmacologia , Concentração de Íons de Hidrogênio , Células-Tronco Pluripotentes Induzidas/citologia , Mitocôndrias/metabolismo , Miócitos Cardíacos/citologia , Miócitos Cardíacos/fisiologia , Imagem Óptica/instrumentação , Oxidantes/farmacologia , Oxirredução/efeitos dos fármacos , Propanolaminas/farmacologia
5.
Nat Commun ; 11(1): 3360, 2020 07 03.
Artigo em Inglês | MEDLINE | ID: mdl-32620763

RESUMO

Nonalcoholic fatty liver disease (NAFLD) is considered the next major health epidemic with an estimated 25% worldwide prevalence. No drugs have yet been approved and NAFLD remains a major unmet need. Here, we identify MCJ (Methylation-Controlled J protein) as a target for non-alcoholic steatohepatitis (NASH), an advanced phase of NAFLD. MCJ is an endogenous negative regulator of the respiratory chain Complex I that acts to restrain mitochondrial respiration. We show that therapeutic targeting of MCJ in the liver with nanoparticle- and GalNAc-formulated siRNA efficiently reduces liver lipid accumulation and fibrosis in multiple NASH mouse models. Decreasing MCJ expression enhances the capacity of hepatocytes to mediate ß-oxidation of fatty acids and minimizes lipid accumulation, which results in reduced hepatocyte damage and fibrosis. Moreover, MCJ levels in the liver of NAFLD patients are elevated relative to healthy subjects. Thus, inhibition of MCJ emerges as an alternative approach to treat NAFLD.


Assuntos
Ácidos Graxos/metabolismo , Proteínas de Choque Térmico HSP40/metabolismo , Fígado/patologia , Mitocôndrias/efeitos dos fármacos , Proteínas Mitocondriais/metabolismo , Chaperonas Moleculares/metabolismo , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Adulto , Idoso , Animais , Conjuntos de Dados como Assunto , Dieta Hiperlipídica/efeitos adversos , Modelos Animais de Doenças , Feminino , Proteínas de Choque Térmico HSP40/antagonistas & inibidores , Proteínas de Choque Térmico HSP40/genética , Hepatócitos/citologia , Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Humanos , Fígado/citologia , Fígado/efeitos dos fármacos , Masculino , Pessoa de Meia-Idade , Mitocôndrias/metabolismo , Proteínas Mitocondriais/antagonistas & inibidores , Proteínas Mitocondriais/genética , Chaperonas Moleculares/antagonistas & inibidores , Chaperonas Moleculares/genética , Nanopartículas/administração & dosagem , Hepatopatia Gordurosa não Alcoólica/etiologia , Hepatopatia Gordurosa não Alcoólica/patologia , Oxirredução/efeitos dos fármacos , Cultura Primária de Células , RNA Interferente Pequeno/administração & dosagem , RNA-Seq
6.
Mutat Res ; 854-855: 503201, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32660825

RESUMO

Oxidative stress is a critical factor in the pathogenesis of several gastrointestinal diseases. Sulforaphane (SFN), a bioactive compound found in cruciferous vegetables, activates the redox-sensitive nuclear erythroid 2-related factor 2 (NRF2). In addition to its protective role, SFN exerts cytotoxic effects on cancer cells. However, there is a lack of information concerning the toxicity of SFN in normal cells. We investigated the effects of SFN on cell viability, antioxidant defenses, and gene expression in human stomach mucosa cells (MNP01). SFN reduced ROS formation and protected the cells against induced oxidative stress but high concentrations increased apoptosis. An intermediate SFN concentration (8 µM) was chosen for RNA sequencing studies. We observed upregulation of genes of the NRF2 (antioxidant) pathway, the DNA damage response, and apoptosis signaling; whereas SFN downregulated cell cycle and DNA repair pathway genes. SFN may be cytoprotective at low concentrations and cytotoxic at high concentrations.


Assuntos
Apoptose/efeitos dos fármacos , Isotiocianatos/farmacologia , Membrana Mucosa/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Estômago/efeitos dos fármacos , Transcrição Genética/efeitos dos fármacos , Anticarcinógenos/farmacologia , Antioxidantes/farmacologia , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Humanos , Membrana Mucosa/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Oxirredução/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais/efeitos dos fármacos , Regulação para Cima/efeitos dos fármacos
7.
Nucleic Acids Res ; 48(15): 8663-8674, 2020 09 04.
Artigo em Inglês | MEDLINE | ID: mdl-32663277

RESUMO

Divalent metal cations are essential to the structure and function of the ribosome. Previous characterizations of the ribosome performed under standard laboratory conditions have implicated Mg2+ as a primary mediator of ribosomal structure and function. Possible contributions of Fe2+ as a ribosomal cofactor have been largely overlooked, despite the ribosome's early evolution in a high Fe2+ environment, and the continued use of Fe2+ by obligate anaerobes inhabiting high Fe2+ niches. Here, we show that (i) Fe2+ cleaves RNA by in-line cleavage, a non-oxidative mechanism that has not previously been shown experimentally for this metal, (ii) the first-order in-line rate constant with respect to divalent cations is >200 times greater with Fe2+ than with Mg2+, (iii) functional ribosomes are associated with Fe2+ after purification from cells grown under low O2 and high Fe2+ and (iv) a small fraction of Fe2+ that is associated with the ribosome is not exchangeable with surrounding divalent cations, presumably because those ions are tightly coordinated by rRNA and deeply buried in the ribosome. In total, these results expand the ancient role of iron in biochemistry and highlight a possible new mechanism of iron toxicity.


Assuntos
Cátions Bivalentes/metabolismo , Ferro/metabolismo , Clivagem do RNA/genética , Ribossomos/genética , Sítios de Ligação , Cátions Bivalentes/química , Ferro/química , Magnésio/química , Magnésio/metabolismo , Metais/química , Metais/metabolismo , Oxirredução/efeitos dos fármacos , Ribossomos/química
8.
Food Chem ; 333: 127528, 2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-32682231

RESUMO

Endogenous lipase and lipoxygenase play important roles in accelerating lipid oxidation. Polyphenols are a series of commonly used chemicals for preserving fish and seafood products, due to their positive inhibitory effects on lipid oxidation. However, the mechanism involved is still unknown. The inhibitory effects of chlorogenic acid (CGA) on lipase and lipoxygenase were investigated and explored with multi- spectroscopic and molecular docking approaches. Results showed that CGA could inhibit the activities of lipase and lipoxygenase with concentration increased in a highly dose-dependent manner. CGA quenched intrinsic fluorescence intensities of enzymes by static quenching and binding with CGA which led to changes in 3D structures of enzymes. Results of the molecular docking confirmed binding modes, binding sites and major interaction forces between CGA and enzymes, which reduced the corresponding activity. Thus, this study could provide basic mechanisms of the inhibitory effects of polyphenols on lipid oxidation during food preservation.


Assuntos
Ácido Clorogênico/metabolismo , Ácido Clorogênico/farmacologia , Metabolismo dos Lipídeos/efeitos dos fármacos , Inibidores de Lipoxigenase/metabolismo , Inibidores de Lipoxigenase/farmacologia , Simulação de Acoplamento Molecular , Animais , Sítios de Ligação , Conservação de Alimentos , Lipase/antagonistas & inibidores , Lipase/química , Lipase/metabolismo , Lipoxigenase/química , Lipoxigenase/metabolismo , Oxirredução/efeitos dos fármacos , Polifenóis/farmacologia , Espectrometria de Fluorescência
9.
Int J Mol Sci ; 21(11)2020 Jun 08.
Artigo em Inglês | MEDLINE | ID: covidwho-574726

RESUMO

Viruses use cell machinery to replicate their genome and produce viral proteins. For this reason, several intracellular factors, including the redox state, might directly or indirectly affect the progression and outcome of viral infection. In physiological conditions, the redox balance between oxidant and antioxidant species is maintained by enzymatic and non-enzymatic systems, and it finely regulates several cell functions. Different viruses break this equilibrium and induce an oxidative stress that in turn facilitates specific steps of the virus lifecycle and activates an inflammatory response. In this context, many studies highlighted the importance of redox-sensitive pathways as novel cell-based targets for therapies aimed at blocking both viral replication and virus-induced inflammation. In the review, we discuss the most recent findings in this field. In particular, we describe the effects of natural or synthetic redox-modulating molecules in inhibiting DNA or RNA virus replication as well as inflammatory pathways. The importance of the antioxidant transcription factor Nrf2 is also discussed. Most of the data reported here are on influenza virus infection. We believe that this approach could be usefully applied to fight other acute respiratory viral infections characterized by a strong inflammatory response, like COVID-19.


Assuntos
Antivirais/uso terapêutico , Oxirredução/efeitos dos fármacos , Viroses/tratamento farmacológico , Animais , Infecções por Coronavirus/tratamento farmacológico , Glutationa/metabolismo , Humanos , Inflamação/tratamento farmacológico , Influenza Humana/tratamento farmacológico , Viroses/imunologia , Viroses/patologia , Replicação Viral/efeitos dos fármacos
10.
Life Sci ; 257: 117918, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32525002

RESUMO

OBJECTIVE: To investigate protective efficacies and mechanisms of Cathelicidin-BF (BF-30) peptide on streptozotocin (STZ)-induced diabetic kidney injury. METHODS: Effects of BF-30 on hydrogen peroxide induced oxidative damage in HK-2 renal cells were assessed by CCK-8 method. Forty STZ-induced diabetic rats with kidney injury were randomly divided into model control group, BF-30 group at different doses (0.1, 0.3 and 0.9 mg/kg). Blood biochemical and kidney related indexes as well adrenal morphological changes, inflammation related markers of diabetic rats were measured. RESULTS: Cell viability of HK-2 cells with oxidative damage induced by hydrogen peroxide were significantly improved by BF-30 with 0.8 µg/mL for 56.5% and 1.6 µg/mL for 82.3% compared with control. Moreover, the decreased reactive oxygen species (ROS), and increased intracellular antioxidant enzymes GPX1, SOD2 and GSH were showed in BF-30 treated groups. In addition, co-incubation of BF-30 in HK-2 cells promoted the increase of p-AMPK and LC3, decreased activation of p-mTOR, BAX and Caspase 3. Chronic treatment of BF-30 improved the STZ-induced diabetic characteristics of diabetic kidney disease (DKD) model rats. Further renal histopathological examination revealed 12-week treatment of BF-30 effectively improved the morphology of nephropathy in DKD rats. Moreover, BF-30 also could ameliorate excessive oxidative stress, renal cell apoptosis and fibrosis, thereby protects renal tissues. CONCLUSION: BF-30 exerted protective effects on STZ-induced kidney injury mainly through the inhibiting oxidative stress in kidney tissue, reducing renal fibrosis, increasing autophagy, and reducing the renal cell apoptosis related proteins to decrease the cell damage and protect nephrocytes.


Assuntos
Lesão Renal Aguda/prevenção & controle , Catelicidinas/farmacologia , Rim/metabolismo , Animais , Antioxidantes/farmacologia , Apoptose/efeitos dos fármacos , Catelicidinas/metabolismo , Diabetes Mellitus Experimental/metabolismo , Feminino , Fibrose/metabolismo , Inflamação/metabolismo , Inflamação/patologia , Rim/patologia , Masculino , Oxirredução/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Substâncias Protetoras/farmacologia , Ratos , Ratos Sprague-Dawley , Espécies Reativas de Oxigênio/metabolismo , Estreptozocina/farmacologia
11.
Toxicol Appl Pharmacol ; 401: 115104, 2020 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-32531296

RESUMO

Nitrofurans (5-nitro-2-hydrazonylfuran as pharmacophore) are a group of widely used antimicrobial drugs but also associated to a variety of side effects. The molecular mechanisms that underlie the cytotoxic effects of nitrofuran drugs are not yet clearly understood. One-electron reduction of 5-nitro group by host enzymes and ROS production via redox cycling have been attributed as mechanisms of cell toxicity. However, the current evidence suggests that nitrofuran ROS generation by itself is uncapable to explain the whole toxic effects associated to nitrofuran consumption, proposing a nitro-reduction independent mechanism of toxicity. In the present work, a series of nitrated and non-nitrated derivatives of nitrofuran drugs were synthesized and evaluated in vitro for their cytotoxicity, ROS-producing capacity, effect on GSH-S-transferase and antibacterial activity. Our studies showed that in human cells non-nitrated derivatives were less toxic than parental drugs but, unexpectedly preserved the ability to generate intracellular ROS in similar amounts to nitrofurans despite not entering into a redox cycle mechanism. In addition, some non-nitrated derivatives although being uncapable to generate ROS exhibited the highest cell toxicity among all derivatives. Inhibition of cytosolic glutathione-S-transferase activity by some derivatives was also observed. Finally, only nitrofuran derivatives displayed antibacterial effect. Results suggest that the combined 2-hydrazonylfuran moiety, redox cycling of 5-nitrofuran, and inhibitory effects on antioxidant enzymes, would be finally responsible for the toxic effects of the studied nitrofurans on mammalian cells.


Assuntos
Antibacterianos/toxicidade , Microssomos Hepáticos/efeitos dos fármacos , Microssomos Hepáticos/metabolismo , Nitrofuranos/toxicidade , Espécies Reativas de Oxigênio/metabolismo , Células A549 , Animais , Antibacterianos/química , Células HCT116 , Células HEK293 , Células HL-60 , Células Hep G2 , Humanos , Masculino , Nitrofuranos/química , Oxirredução/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley
12.
PLoS One ; 15(6): e0234510, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32555619

RESUMO

Seeds stored in controlled conditions in gene banks, faster or slower lose their viability. The effects of seed moisture content levels (ca. 5, 8, 11%) combined with storage temperatures (-3°, -18°, -196°C) were investigated in terms of the description of seeds defined as orthodox under oxidative stress after seed storage, during germination, and initial seedling growth. Hydrogen peroxide (H2O2), thiobarbituric acid reactive substances (TBARS) and ascorbate (Asc) were analyzed in relation to seed germinability and seedlings emergence in three species: Malus sylvestris L., Prunus avium L. and Prunus padus L. The effect of seed storage conditions on H2O2 levels appeared in germinated seeds after the third year of storage in each species. The H2O2 levels were negatively correlated with the germination and seedling emergence of P. avium seeds after three years of storage under all examined combinations. The emergence of P. padus seedlings was not linked to any of the stress markers tested. The P. padus seed biochemical traits were least altered by storage conditions, and the seeds produced tolerant seedlings of relatively high levels of H2O2 and TBARS. To cope with different H2O2 levels, TBARS levels, and Asc levels in seeds of three species varying storage conditions different molecular responses, i.e. repairing mechanisms, were applied during stratification to compensate for the storage conditions and, as a result, seeds remained viable and seedlings were successfully established.


Assuntos
Malus/metabolismo , Prunus avium/metabolismo , Plântula/genética , Germinação/efeitos dos fármacos , Peróxido de Hidrogênio/metabolismo , Malus/crescimento & desenvolvimento , Oxirredução/efeitos dos fármacos , Prunus avium/crescimento & desenvolvimento , Plântula/crescimento & desenvolvimento , Sementes/genética , Sementes/crescimento & desenvolvimento , Sementes/metabolismo , Temperatura
13.
Int J Mol Sci ; 21(11)2020 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-32521619

RESUMO

Viruses use cell machinery to replicate their genome and produce viral proteins. For this reason, several intracellular factors, including the redox state, might directly or indirectly affect the progression and outcome of viral infection. In physiological conditions, the redox balance between oxidant and antioxidant species is maintained by enzymatic and non-enzymatic systems, and it finely regulates several cell functions. Different viruses break this equilibrium and induce an oxidative stress that in turn facilitates specific steps of the virus lifecycle and activates an inflammatory response. In this context, many studies highlighted the importance of redox-sensitive pathways as novel cell-based targets for therapies aimed at blocking both viral replication and virus-induced inflammation. In the review, we discuss the most recent findings in this field. In particular, we describe the effects of natural or synthetic redox-modulating molecules in inhibiting DNA or RNA virus replication as well as inflammatory pathways. The importance of the antioxidant transcription factor Nrf2 is also discussed. Most of the data reported here are on influenza virus infection. We believe that this approach could be usefully applied to fight other acute respiratory viral infections characterized by a strong inflammatory response, like COVID-19.


Assuntos
Antivirais/uso terapêutico , Oxirredução/efeitos dos fármacos , Viroses/tratamento farmacológico , Animais , Infecções por Coronavirus/tratamento farmacológico , Glutationa/metabolismo , Humanos , Inflamação/tratamento farmacológico , Influenza Humana/tratamento farmacológico , Viroses/imunologia , Viroses/patologia , Replicação Viral/efeitos dos fármacos
14.
Biol Res ; 53(1): 26, 2020 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-32513271

RESUMO

BACKGROUND: There is an emerging field to put into practice new strategies for developing molecules with antimicrobial properties. In this line, several metals and metalloids are currently being used for these purposes, although their cellular effect(s) or target(s) in a particular organism are still unknown. Here we aimed to investigate and analyze Au3+ toxicity through a combination of biochemical and molecular approaches. RESULTS: We found that Au3+ triggers a major oxidative unbalance in Escherichia coli, characterized by decreased intracellular thiol levels, increased superoxide concentration, as well as by an augmented production of the antioxidant enzymes superoxide dismutase and catalase. Because ROS production is, in some cases, associated with metal reduction and the concomitant generation of gold-containing nanostructures (AuNS), this possibility was evaluated in vivo and in vitro. CONCLUSIONS: Au3+ is toxic for E. coli because it triggers an unbalance of the bacterium's oxidative status. This was demonstrated by using oxidative stress dyes and antioxidant chemicals as well as gene reporters, RSH concentrations and AuNS generation.


Assuntos
Escherichia coli/efeitos dos fármacos , Ouro/toxicidade , Nanopartículas Metálicas/toxicidade , Oxirredução/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos
15.
Nucleic Acids Res ; 48(12): 6799-6810, 2020 07 09.
Artigo em Inglês | MEDLINE | ID: mdl-32484546

RESUMO

Structure and/or function of proteins are frequently affected by oxidative/nitrosative stress via posttranslational modifications. Aminoacyl-tRNA synthetases (aaRSs) constitute a class of ubiquitously expressed enzymes that control cellular protein homeostasis. Here, we found the activity of human mitochondrial (mt) threonyl-tRNA synthetase (hmtThrRS) is resistant to oxidative stress (H2O2) but profoundly sensitive to nitrosative stress (S-nitrosoglutathione, GSNO). Further study showed four Cys residues in hmtThrRS were modified by S-nitrosation upon GSNO treatment, and one residue was one of synthetic active sites. We analyzed the effect of modification at individual Cys residue on aminoacylation and editing activities of hmtThrRS in vitro and found that both activities were decreased. We further confirmed that S-nitrosation of mtThrRS could be readily detected in vivo in both human cells and various mouse tissues, and we systematically identified dozens of S-nitrosation-modified sites in most aaRSs, thus establishing both mitochondrial and cytoplasmic aaRS species with S-nitrosation ex vivo and in vivo, respectively. Interestingly, a decrease in the S-nitrosation modification level of mtThrRS was observed in a Huntington disease mouse model. Overall, our results establish, for the first time, a comprehensive S-nitrosation-modified aaRS network and a previously unknown mechanism on the basis of the inhibitory effect of S-nitrosation on hmtThrRS.


Assuntos
Mitocôndrias/genética , Nitrosação/genética , Estresse Nitrosativo/genética , Treonina-tRNA Ligase/genética , Aminoacil-tRNA Sintetases/genética , Aminoacilação/genética , Animais , Domínio Catalítico/efeitos dos fármacos , Células HeLa , Humanos , Peróxido de Hidrogênio/química , Peróxido de Hidrogênio/farmacologia , Cinética , Camundongos , Mitocôndrias/enzimologia , Oxirredução/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/genética , Processamento de Proteína Pós-Traducional/efeitos dos fármacos , Processamento de Proteína Pós-Traducional/genética , Treonina-tRNA Ligase/química
16.
Life Sci ; 254: 117787, 2020 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-32417372

RESUMO

AIMS: To evaluate the effects of esculin treatment on P2X7 receptor and mitochondrial dysfunction in the renal cortex of diabetic rats. MAIN METHODS: Male Wistar rats, 7 weeks old, were unilaterally nephrectomized. Part of these animals were induced to diabetes using streptozotocin (60 mg/kg). Diabetes was confirmed 48 h after induction, with blood glucose levels ≥200 mg/dL. Part of control and diabetic animals were selected to receive daily doses of esculin (50 mg/kg), during 8 weeks. The animals were placed in metabolic cages at the eighth week of protocol for 24 h urine collection and a small aliquot of blood was collected for biochemical analysis. After this procedure, the animals were euthanized and the remaining kidney was stored for histopathological analysis, Western blotting and mitochondrial high-resolution respirometry. KEY FINDINGS: Although esculin did not change metabolic parameters, renal biochemical function, neither TBARS in DM rats, esculin reduced P2X7 levels in these animals and restored mitochondrial function via glycolysis substrates and ß-oxidation. Besides, at the histological analysis, we observed that esculin reduced inflammatory infiltrates and collagen IV deposits as compared to diabetic group. SIGNIFICANCE: Esculin attenuated the development of renal injuries caused by hyperglycemia, proinflammatory and oxidative mechanisms mediated by P2X7 receptor, as seen by histological findings and improved mitochondrial function in diabetic animals. This suggests that esculin could be used as an adjuvant therapy to prevent the diabetic nephropathy.


Assuntos
Diabetes Mellitus Experimental/metabolismo , Esculina/farmacologia , Córtex Renal/metabolismo , Mitocôndrias/metabolismo , Receptores Purinérgicos P2X7/metabolismo , Animais , Glicemia/metabolismo , Diabetes Mellitus Experimental/patologia , Colágenos Fibrilares/metabolismo , Glicólise/efeitos dos fármacos , Inflamação/prevenção & controle , Córtex Renal/patologia , Masculino , Oxirredução/efeitos dos fármacos , Ratos , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismo
17.
Ecotoxicol Environ Saf ; 197: 110593, 2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-32294596

RESUMO

Arable land contamination with nickel (Ni) has become a major threat to worldwide crop production. Recently, melatonin has appeared as a promising stress-relief substance that can alleviate heavy metal-induced phytotoxicity in plants. However, the plausible underlying mechanism of melatonin function under Ni stress has not been fully substantiated in plants. Herein, we conducted an experiment that unveiled critical mechanisms in favor of melatonin-mediated Ni-stress tolerance in tomato. Ni stress markedly inhibited growth and biomass by impairing the photosynthesis, photosystem function, mineral homeostasis, root activity, and osmotic balance. In contrast, melatonin application notably reinforced the plant growth traits, increased photosynthesis efficiency in terms of chlorophyll content, upregulation of chlorophyll synthesis genes, i.e. POR, CAO, CHL G, gas exchange parameters, and PSII maximum efficiency (Fv/Fm), decreased Ni accumulation and increased mineral nutrient homeostasis. Moreover, melatonin efficiently restricted the hydrogen peroxide (H2O2) and superoxide radical production and increased RBOH expression and restored cellular integrity (less malondialdehyde and electrolyte leakage) through triggering the antioxidant enzyme activities and modulating AsA-GSH pools. Notably, oxidative stress was effectively mitigated by upregulation of several defense genes (SOD, CAT, APX, GR, GST, MDHAR, DHAR) and melatonin biosynthesis-related genes (TDC, T5S, SNAT, ASMT). Besides, melatonin treatment enhanced secondary metabolites (phenols, flavonoids, and anthocyanin) contents along with their encoding genes (PAL, CHS) expression, and these metabolites potentially restricted excess H2O2 accumulation. In conclusion, our findings deciphered the potential functions of melatonin in alleviating Ni-induced phytotoxicity in tomato through boosting the biomass production, photosynthesis, nutrient uptake, redox balance, and secondary metabolism.


Assuntos
Antioxidantes/farmacologia , Lycopersicon esculentum/efeitos dos fármacos , Melatonina/farmacologia , Níquel/toxicidade , Poluentes do Solo/toxicidade , Antioxidantes/metabolismo , Lycopersicon esculentum/crescimento & desenvolvimento , Lycopersicon esculentum/metabolismo , Melatonina/metabolismo , Níquel/metabolismo , Oxirredução/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/genética , Fotossíntese/efeitos dos fármacos , Metabolismo Secundário/efeitos dos fármacos , Metabolismo Secundário/genética , Plântula/efeitos dos fármacos , Plântula/crescimento & desenvolvimento , Plântula/metabolismo , Poluentes do Solo/metabolismo
18.
J Med Chem ; 63(10): 5568-5584, 2020 05 28.
Artigo em Inglês | MEDLINE | ID: mdl-32319768

RESUMO

Chemotherapy remains one of the dominant treatments to cure cancer. However, due to the many inherent drawbacks, there is a search for new chemotherapeutic drugs. Many classes of compounds have been investigated over the years to discover new targets and synergistic mechanisms of action including multicellular targets. In this work, we designed a new chemotherapeutic drug candidate against cancer, namely, [Ru(DIP)2(sq)](PF6) (Ru-sq) (DIP = 4,7-diphenyl-1,10-phenanthroline; sq = semiquinonate ligand). The aim was to combine the great potential expressed by Ru(II) polypyridyl complexes and the singular redox and biological properties associated with the catecholate moiety. Experimental evidence (e.g., X-ray crystallography, electron paramagnetic resonance, electrochemistry) demonstrates that the semiquinonate is the preferred oxidation state of the dioxo ligand in this complex. The biological activity of Ru-sq was then scrutinized in vitro and in vivo, and the results highlight the promising potential of this complex as a chemotherapeutic agent against cancer.


Assuntos
Antineoplásicos/química , Antineoplásicos/metabolismo , Quinonas/química , Quinonas/metabolismo , Rutênio/química , Rutênio/metabolismo , Animais , Antineoplásicos/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/fisiologia , Feminino , Células HeLa , Humanos , Ligantes , Camundongos , Camundongos Nus , Oxirredução/efeitos dos fármacos , Quinonas/farmacologia , Rutênio/farmacologia , Ensaios Antitumorais Modelo de Xenoenxerto/métodos
19.
PLoS One ; 15(3): e0230812, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32214399

RESUMO

The aim of this study was to assess the efficacy of lactic acid (LA), caprylic acid (CA), high- (HDI) and low- (LDI) dose gamma irradiation and LDI combined with LA or CA on the inactivation of a pool of Shiga toxin-producing Escherichia coli (STEC) strains inoculated on beef trimmings. The three most efficacious treatments were selected to study their effect on meat quality parameters and sensory attributes. The inoculum included five native STEC serogroups (O26, O103, O111, O145 and O157). The treatments applied were 0.5% LA, 0.04% CA, 0.5 kGy LDI, 2 kGy HDI, LDI+LA and LDI+CA. Beef trimmings were divided into two groups; one was inoculated with high (7 log CFU/g) and the other with low (1 log CFU/g) level of inoculum. Efficacy was assessed by estimating log reduction and reduction of stx- and eae-positive samples after enrichment, respectively. Results showed that treatments with organic acids alone were not effective in reducing STEC populations. For high inoculum samples, the most effective treatment was HDI followed by LDI+LA and LDI alone or combined with CA. For low inoculum samples, the most effective treatment was HDI followed by LDI alone or combined with organic acids. Concerning meat quality parameters and sensory attributes, irradiation treatments (LDI and HDI) caused minimal changes, while LDI+LA modified them significantly compared with the control. Therefore, based on our results, no benefits were observed after combining organic acids with gamma irradiation.


Assuntos
Caprilatos/farmacologia , Raios gama , Ácido Láctico/farmacologia , Carne Vermelha/microbiologia , Escherichia coli Shiga Toxigênica/efeitos dos fármacos , Escherichia coli Shiga Toxigênica/efeitos da radiação , Relação Dose-Resposta à Radiação , Qualidade dos Alimentos , Inocuidade dos Alimentos , Concentração de Íons de Hidrogênio , Metabolismo dos Lipídeos/efeitos dos fármacos , Metabolismo dos Lipídeos/efeitos da radiação , Viabilidade Microbiana/efeitos dos fármacos , Viabilidade Microbiana/efeitos da radiação , Oxirredução/efeitos dos fármacos , Oxirredução/efeitos da radiação , Escherichia coli Shiga Toxigênica/fisiologia , Paladar
20.
Nat Commun ; 11(1): 1228, 2020 03 06.
Artigo em Inglês | MEDLINE | ID: mdl-32144272

RESUMO

The BCL-2 antagonist venetoclax is highly effective in multiple myeloma (MM) patients exhibiting the 11;14 translocation, the mechanistic basis of which is unknown. In evaluating cellular energetics and metabolism of t(11;14) and non-t(11;14) MM, we determine that venetoclax-sensitive myeloma has reduced mitochondrial respiration. Consistent with this, low electron transport chain (ETC) Complex I and Complex II activities correlate with venetoclax sensitivity. Inhibition of Complex I, using IACS-010759, an orally bioavailable Complex I inhibitor in clinical trials, as well as succinate ubiquinone reductase (SQR) activity of Complex II, using thenoyltrifluoroacetone (TTFA) or introduction of SDHC R72C mutant, independently sensitize resistant MM to venetoclax. We demonstrate that ETC inhibition increases BCL-2 dependence and the 'primed' state via the ATF4-BIM/NOXA axis. Further, SQR activity correlates with venetoclax sensitivity in patient samples irrespective of t(11;14) status. Use of SQR activity in a functional-biomarker informed manner may better select for MM patients responsive to venetoclax therapy.


Assuntos
Compostos Bicíclicos Heterocíclicos com Pontes/farmacologia , Complexo II de Transporte de Elétrons/metabolismo , Complexo I de Transporte de Elétrons/metabolismo , Transporte de Elétrons/efeitos dos fármacos , Mieloma Múltiplo/tratamento farmacológico , Sulfonamidas/farmacologia , Compostos Bicíclicos Heterocíclicos com Pontes/uso terapêutico , Linhagem Celular Tumoral , Cromossomos Humanos Par 11/genética , Cromossomos Humanos Par 14/genética , Resistencia a Medicamentos Antineoplásicos , Complexo I de Transporte de Elétrons/antagonistas & inibidores , Complexo II de Transporte de Elétrons/antagonistas & inibidores , Técnicas de Silenciamento de Genes , Humanos , Proteínas de Membrana/genética , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Mieloma Múltiplo/genética , Mieloma Múltiplo/patologia , Mutação , Oxirredução/efeitos dos fármacos , Seleção de Pacientes , Prognóstico , Proteínas Proto-Oncogênicas c-bcl-2/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Sulfonamidas/uso terapêutico , Tenoiltrifluoracetona/farmacologia , Translocação Genética
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