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1.
Yakugaku Zasshi ; 140(9): 1119-1128, 2020.
Artigo em Japonês | MEDLINE | ID: mdl-32879244

RESUMO

Humans are exposed to various xenobiotic electrophiles on a daily basis. Electrophiles form covalent adducts with nucleophilic residues of proteins. Redox signaling, which consists of effector molecules (e.g., kinases and transcription factors) and redox sensor proteins with low pKa cysteine residues, is involved in cell survival, cell proliferation, quality control of cellular proteins and oxidative stress response. Herein, we showed that at a low dose, xenobiotic electrophiles selectively modified redox sensor proteins through covalent modification of their reactive thiols, resulting in activation of a variety of redox signaling pathways. However, increasing the dose of xenobiotic electrophiles caused non-selective and extensive modification of cellular proteins involved in toxicity. Of interest, reactive sulfur species (RSS), such as hydrogen sulfide (H2S), cysteine persulfide (CysSSH), glutathione persulfide (GSSH) and even synthetic polysulfide (e.g., Na2S4), readily captured xenobiotic electrophiles, forming their sulfur adducts, which was associated with inactivation of the electrophiles. Our findings suggest that an adaptive response through redox signaling activation and RSS-mediated electrophile capturing is involved in the regulation of electrophilic stress.


Assuntos
Cisteína/análogos & derivados , Dissulfetos/metabolismo , Glutationa/análogos & derivados , Sulfeto de Hidrogênio/metabolismo , Oxirredução , Estresse Oxidativo , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais , Animais , Cisteína/metabolismo , Glutationa/metabolismo , Humanos , Compostos de Sulfidrila/metabolismo , Xenobióticos/metabolismo
2.
Anticancer Res ; 40(9): 5159-5170, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32878804

RESUMO

BACKGROUND/AIM: The aim of this study was to elucidate the possibility of sensitizing colon cancer cells to the chemotherapeutic drug SN38 and investigate its mechanism of action after combined treatment with electroporation (EP). MATERIALS AND METHODS: Cells were treated with SN38, EP and their combination for 24/48 h. The cell viability, actin cytoskeleton integrity, mitochondrial superoxide, hydroperoxides, total glutathione, phosphatidyl serine expression, DNA damages and expression of membrane ABC transporters were analyzed using conventional analytical tests. RESULTS: The combination of EP and SN38 affected cell viability and cytoskeleton integrity. This effect was accompanied by: (i) high production of intracellular superoxide and hydroperoxides and depletion of glutathione; (ii) increased DNA damage and apoptotic/ferroptotic cell death; (iii) changes in the expression of membrane ABC transporters - up-regulation of SLCO1B1 and retention of SN38 in the cells. CONCLUSION: The anticancer effect of the combined treatment of SN38 and EP is related to changes in the redox-homeostasis of cancer cells, leading to cell death via apoptosis and/or ferroptosis. Thus, electroporation has a potential to increase the sensitivity of cancer cells to conventional anticancer therapy with SN38.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Camptotecina/análogos & derivados , Camptotecina/farmacologia , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Oxirredução , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Neoplasias do Colo/metabolismo , Neoplasias do Colo/patologia , Dano ao DNA/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/genética , Sinergismo Farmacológico , Imunofluorescência , Glutationa/metabolismo , Humanos , Modelos Biológicos , Espécies Reativas de Oxigênio/metabolismo
3.
Ecotoxicol Environ Saf ; 204: 111069, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32758696

RESUMO

We studied the absorption, cytotoxicity and oxidative stress markers of Paralytic Shellfish Toxins (PST) from three extracts from Alexandrium catenella and A. ostenfeldii, in middle Oncorhynchus mykiss intestine in vitro and ex vivo preparations. We measured glutathione (GSH) content, glutathione-S transferase (GST), glutathione reductase (GR) and catalase (CAT) enzymatic activity, and lipid peroxidation in isolated epithelium exposed to 0.13 and 1.3 µM PST. ROS production and lysosomal membrane stability (as neutral red retention time 50%, NRRT50) were analyzed in isolated enterocytes exposed to PST alone or plus 3 µM of the ABCC transport inhibitor MK571. In addition, the concentration-dependent effects of PST on NRRT50 were assayed in a concentration range from 0 to 1.3 µM PST. We studied the effects of three different PST extracts on the transport rate of the ABCC substrate DNP-SG by isolated epithelium. The extract with highest inhibition capacity was selected for studying polarized DNP-SG transport in everted and non-everted intestinal segments. We registered lower GSH content and GST activity, and higher GR activity, with no significant changes in CAT activity, lipid peroxidation or ROS level. PST exposure decreased NRRT50 in a concentration-depend manner (IC50 = 0.0045 µM), but PST effects were not augmented by addition of MK571. All the three PST extracts inhibited ABCC transport activity, but this inhibition was effective only when the toxins were applied to the apical side of the intestine and DNP-SG transport was measured at the basolateral side. Our results indicate that PST are absorbed by the enterocytes from the intestine lumen. Inside the enterocytes, these toxins decrease GSH content and inhibit the basolateral ABCC transporters affecting the normal functions of the cell. Furthermore, PST produce a strong cytotoxic effect to the enterocytes by damaging the lysosomal membrane, even at low, non-neurotoxic concentrations.


Assuntos
Transportadores de Cassetes de Ligação de ATP/metabolismo , Glutationa/análogos & derivados , Mucosa Intestinal/efeitos dos fármacos , Lisossomos/efeitos dos fármacos , Oncorhynchus mykiss/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Saxitoxina/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Catalase/metabolismo , Dinoflagelados/metabolismo , Enterócitos/efeitos dos fármacos , Enterócitos/metabolismo , Glutationa/metabolismo , Glutationa Transferase/metabolismo , Mucosa Intestinal/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Lisossomos/metabolismo , Frutos do Mar
4.
Ecotoxicol Environ Saf ; 204: 111086, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32781345

RESUMO

In the present research, Silene vulgaris as a representative species growing on both unpolluted and heavy metal (HM) polluted terrains were used to identify ecotype-specific responses to metallic stress. Growth, cell ultrastructure and element accumulations were compared between non-metallicolous (NM), calamine (CAL) and serpentine (SER) specimens untreated with HMs and treated with Pb, Cd and Zn ions under in vitro conditions. Moreover, proteins' modifications related to their level, carbonylation and degradations via vacuolar proteases were verified and linked with potential mechanisms to cope with ions toxicity. Our experiment revealed diversified strategy of HM uptake in NM and both metallicolous ecotypes, in which antagonistic relationship of Zn and Pb/Cd ions provided survival benefits for the whole organism. Despite this similarity, growth rate and metabolic pathways induced in CAL and SER shoots varied significantly. Exposition to HMs in CAL culture led to drop in protein level by approximately 16% compared to the control. This parameter nearly correlated with the enhanced activity of proteases at pH 5.2 as well as possible glutamate changes to proline and reduced glutathione, resulting in intensified growth and first signs of cell senescence. In turn, SER shoots were characterized by growth retardation (to 53% of the control), although protein level and carbonylation were not modified, while a deeper insight into protein network showed its remodeling towards production of polyamines and 2-oxoglutarate delivered to the Krebs cycle. Contrary, an uncontrolled HM influx in NM shoots contributed to morpho-structural disorders accompanied by an increase activity of proteases involved in the degradation of oxidized proteins, what pointed to metal-induced autophagy. Taken together, S. vulgaris ecotypes respond to stress by triggering various mechanisms engaged their survival and/or death under HM treatment.


Assuntos
Cádmio/toxicidade , Chumbo/toxicidade , Proteínas de Plantas/metabolismo , Silene/efeitos dos fármacos , Poluentes do Solo/toxicidade , Zinco/toxicidade , Autofagia/efeitos dos fármacos , Bioacumulação/efeitos dos fármacos , Cádmio/metabolismo , Ecótipo , Glutationa/metabolismo , Chumbo/metabolismo , Modelos Teóricos , Estresse Oxidativo/efeitos dos fármacos , Brotos de Planta/efeitos dos fármacos , Brotos de Planta/crescimento & desenvolvimento , Brotos de Planta/metabolismo , Brotos de Planta/ultraestrutura , Silene/crescimento & desenvolvimento , Silene/metabolismo , Silene/ultraestrutura , Poluentes do Solo/metabolismo , Zinco/metabolismo
5.
Nature ; 585(7823): 113-118, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32814895

RESUMO

Cancer cells, including melanoma cells, often metastasize regionally through the lymphatic system before metastasizing systemically through the blood1-4; however, the reason for this is unclear. Here we show that melanoma cells in lymph experience less oxidative stress and form more metastases than melanoma cells in blood. Immunocompromised mice with melanomas derived from patients, and immunocompetent mice with mouse melanomas, had more melanoma cells per microlitre in tumour-draining lymph than in tumour-draining blood. Cells that metastasized through blood, but not those that metastasized through lymph, became dependent on the ferroptosis inhibitor GPX4. Cells that were pretreated with chemical ferroptosis inhibitors formed more metastases than untreated cells after intravenous, but not intralymphatic, injection. We observed multiple differences between lymph fluid and blood plasma that may contribute to decreased oxidative stress and ferroptosis in lymph, including higher levels of glutathione and oleic acid and less free iron in lymph. Oleic acid protected melanoma cells from ferroptosis in an Acsl3-dependent manner and increased their capacity to form metastatic tumours. Melanoma cells from lymph nodes were more resistant to ferroptosis and formed more metastases after intravenous injection than did melanoma cells from subcutaneous tumours. Exposure to the lymphatic environment thus protects melanoma cells from ferroptosis and increases their ability to survive during subsequent metastasis through the blood.


Assuntos
Ferroptose , Linfa/metabolismo , Melanoma/patologia , Metástase Neoplásica/patologia , Animais , Sobrevivência Celular , Coenzima A Ligases/metabolismo , Feminino , Ferroptose/efeitos dos fármacos , Glutationa/metabolismo , Humanos , Ferro/metabolismo , Masculino , Melanoma/sangue , Melanoma/metabolismo , Camundongos , Metástase Neoplásica/tratamento farmacológico , Ácido Oleico/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Fosfolipídeo Hidroperóxido Glutationa Peroxidase/metabolismo , Análise de Componente Principal
6.
Zhonghua Wei Zhong Bing Ji Jiu Yi Xue ; 32(7): 819-823, 2020 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-32788016

RESUMO

OBJECTIVE: To observe the changes of renal function in critically ill patients after using vancomycin and analyze the renal protective effect of reduced glutathione (GSH) on vancomycin nephrotoxicity. METHODS: The clinical data of patients with severe infection who were administered with vancomycin or plus infusion of GSH admitted to intensive care unit (ICU) of Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine from January 2012 to October 2019 were collected during the study period, and the patients were divided into only vancomycin group and vancomycin combined with GSH group. The gender, age, body weight, underlying diseases, clinical diagnosis, severity score, renal function before and after taking the medicine, average daily dose and treatment duration of vancomycin and GSH, length of ICU stay and clinical outcomes were recorded and analyzed. RESULTS: A total of 217 patients were enrolled, with 127 patients in the only vancomycin group, and 90 in the combination with GSH group. There was no statistically significant difference between the two groups in terms of gender, body weight, duration of vancomycin treatment, history of chronic kidney disease, and ICU mortality. The main causes of 217 patients admitted to the ICU were lung infection, sepsis/septic shock, and severe acute pancreatitis (SAP) and so on. The majority of patients in only vancomycin group had lung infections (63.0%), while the main etiology in combination with GSH group was SAP (46.7%). Compared with the only vancomycin group, the acute physiology and chronic health evaluation II (APACHE II) score in the combination with GSH group significantly decreased [15.0 (10.5, 21.0) vs. 27.0 (20.0, 31.0), P < 0.01], but the quick sequential organ failure assessment (qSOFA) score was significantly higher [1.0 (0, 1.0) vs. 0 (0, 0.2), P < 0.01], the basic renal function was poorer [serum creatinine (SCr, µmol/L): 102.0 (64.7, 178.0) vs. 56.0 (42.0, 71.0), blood urea nitrogen (BUN, mmol/L): 11.5 (6.7, 18.4) vs. 4.70 (3.5, 8.1), both P < 0.05], and the average daily dose of vancomycin was lower (mg×kg-1×d-1: 22.22±10.09 vs. 25.51±9.56, P < 0.05). The renal function of patients was getting worse significantly after vancomycin usage as compared with before [SCr (µmol/L): 68.0 (50.3, 103.4) vs. 56.0 (42.0, 71.0), BUN (mmol/L): 5.4 (3.6, 9.6) vs. 4.7 (3.5, 8.1), both P < 0.05]. However, the renal function indexes of the combination with GSH group were better than those before treatment [SCr (µmol/L): 81.0 (61.0, 129.0) vs. 102.0 (64.7, 178.0), P < 0.05; BUN (mmol/L): 8.4 (6.2, 17.8) vs. 11.5 (6.7, 18.4), P > 0.05], and the length of ICU stay was significantly shorter than that in the only vancomycin group [days: 29.0 (14.0, 54.2) vs. 37.0 (25.0, 55.0), P < 0.05]. CONCLUSIONS: The incidence of drug-induced renal injury caused by vancomycin is high. The GSH can significantly reduce their renal toxicity and shorten the length of hospital stay.


Assuntos
Antibacterianos/efeitos adversos , Glutationa/metabolismo , Rim/efeitos dos fármacos , Pancreatite , Vancomicina/efeitos adversos , Doença Aguda , China , Estado Terminal , Humanos , Unidades de Terapia Intensiva , Prognóstico , Estudos Retrospectivos
7.
J Toxicol Sci ; 45(8): 493-502, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32741899

RESUMO

Gefitinib (GEF) is the first selective tyrosine kinase inhibitor of epidermal growth factor receptor. It is associated with the occurrence of clinical drug-induced liver injury. Although GEF is metabolized to chemically reactive metabolites by cytochrome P450 3A and 1A enzymes and then conjugated to glutathione (GSH), whether these reactive metabolites contribute to GEF-induced toxicity remains unknown. In this study, we investigated whether GSH depletion can sensitize mice to liver injury caused by GEF. Male C57BL/6J mice were intraperitoneally pretreated with L-buthionine (S,R)-sulfoximine (BSO) at 700 mg/kg to inhibit GSH synthesis and then orally administered GEF at 500 mg/kg every 24 hr for 4 consecutive days. The coadministration of BSO and GEF increased plasma alanine aminotransferase (ALT) levels to approximately 700 U/L and 1600 U/L at 72 and 96 hr after the first administration, respectively, whereas the increase in plasma ALT levels in mice receiving GEF at 500 mg/kg alone was limited, suggesting that GSH plays a protective role in GEF-induced liver injury. Histological examination showed nuclear karyorrhexis and sporadic single hepatocyte death in the livers of BSO+GEF coadministered mice. In these mice, the hepatic expression levels of heme oxygenase 1 (Hmox1) and metallothionein 2 (Mt2) mRNA, caspase 3/7 enzymatic activity, and the amounts of 2-thiobarbiuric acid reactive substances were significantly increased, suggesting the presence of oxidative stress, which may be associated with hepatocellular death. Together, these results show that oxidative stress as well as the reactive metabolites of GEF are involved in GEF-induced liver injury in GSH-depleted mice.


Assuntos
Doença Hepática Induzida por Substâncias e Drogas/etiologia , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Gefitinibe/efeitos adversos , Gefitinibe/toxicidade , Glutationa/deficiência , Glutationa/metabolismo , Fígado/metabolismo , Fígado/patologia , Estresse Oxidativo , Inibidores de Proteínas Quinases/efeitos adversos , Inibidores de Proteínas Quinases/toxicidade , Animais , Butionina Sulfoximina/farmacologia , Doença Hepática Induzida por Substâncias e Drogas/patologia , Citocromo P-450 CYP3A/fisiologia , Progressão da Doença , Gefitinibe/metabolismo , Glutationa/fisiologia , Camundongos Endogâmicos C57BL , Inibidores de Proteínas Quinases/metabolismo
8.
Int J Nanomedicine ; 15: 4763-4778, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32753865

RESUMO

Introduction: Methotrexate exhibits poor cutaneous bioavailability and systemic side effects on topical administration, so there is an unmet need for a novel carrier and its optimized therapy. Methotrexate-loaded nanostructured lipid carriers (MTXNLCs) were formulated and characterized to determine in vitro drug release and evaluate the role of MTXNLC gel in the topical treatment of psoriasis. Methods: A solvent diffusion technique was employed to prepare MTXNLCs, which was optimized using 32 full factorial designs. The mean diameter and surface morphology of MTXNLCs was evaluated. The crystallinity of lyophilized MTXNLCs was characterized by differential scanning calorimetry (DSC) and powder X-ray diffraction (XRD). MTXNLCs were integrated in 1% w/w Carbopol 934 P gel base, and in vitro skin deposition studies in human cadaver skin (HCS) were carried out. Results: The optimized MTXNLCs were rod-shaped, with an average particle size of 253 ± 8.65 nm, a zeta potential of -26.4±0.86 mV, and EE of 54.00±1.49%. DSC and XRD data confirmed the formation of NLCs. Significantly higher deposition of MTX was found in HCS from MTXNLC gel (71.52 ±1.13%) as compared to MTX plain gel (38.48±0.96%). In vivo studies demonstrated significant improvement in therapeutic response and reduction in local side effects with MTXNLCs-loaded gel in the topical treatment of psoriasis. Anti-psoriatic efficacy of MTXNLCs 100 ug/cm2 compared with plain MTX gel was evaluated using imiquimod (IMQ)-induced psoriasis in BALB/c mice. The topical application of MTXNLCs to the mouse ear resulted in a significant reduction of psoriatic area and severity index, oxidative stress, inflammatory cytokines like TNF-α, IL-1ß, and IL-6 and IMQ-induced histopathological alterations in mouse ear samples. Conclusion: Developed formulation of MTXNLC gel demonstrated better anti-psoriatic activity and also displayed prolonged and sustained release effect, which shows that it can be a promising alternative to existing MTX formulation for the treatment of psoriasis.


Assuntos
Composição de Medicamentos , Géis/química , Imiquimode/uso terapêutico , Inflamação/tratamento farmacológico , Lipídeos/química , Metotrexato/uso terapêutico , Nanoestruturas/química , Psoríase/tratamento farmacológico , Administração Cutânea , Administração Tópica , Animais , Catalase/metabolismo , Citocinas/metabolismo , Portadores de Fármacos/química , Liberação Controlada de Fármacos , Glutationa/metabolismo , Humanos , Inflamação/patologia , Malondialdeído/metabolismo , Camundongos Endogâmicos BALB C , Nanoestruturas/ultraestrutura , Tamanho do Órgão , Superóxido Dismutase/metabolismo
9.
Ecotoxicol Environ Saf ; 202: 110963, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32800234

RESUMO

Harmful Phaeocystis blooms disrupt seawater recreation and pose serious challenges to aquatic animals. The growth performance, phenotypic traits, and antioxidant responses of Brachionus plicatilis Müller to different proportions of Phaeocystis globosa were evaluated. B. plicatilis rotifers were exposed to cultures with Chlorella sp. and P. globosa alone and in mixtures of these two algae with proportions of 25%, 50%, and 75%. The total proportions of the two algae were maintained at 100%. Results showed that P. globosa inhibited the rotifer net reproduction rate, intrinsic growth rate, and finite rate of increase (P < 0.01). It induced the formation of defense phenotypic traits in terms of the increased posterolateral spine length and the reduced body length, swimming speed, and grazing rate of B. plicatilis (P < 0.001). Superoxide dismutase and catalase activities decreased, but the reactive oxygen species levels increased as the proportions of P. globosa increased (P < 0.01). The mixture of 50% Chlorella and 50% Phaeocystis positively affected the glutathione content, glutathione peroxidase activity, and generation time of rotifers (P < 0.01). Although P. globosa released toxicants with harmful effects on the growth performance of B. plicatilis, rotifers changed their antioxidant defense system and formed defense phenotypic traits in response to eutrophic conditions.


Assuntos
Antioxidantes/metabolismo , Haptófitas/crescimento & desenvolvimento , Proliferação Nociva de Algas , Rotíferos/crescimento & desenvolvimento , Animais , Chlorella/crescimento & desenvolvimento , Glutationa/metabolismo , Fenótipo , Espécies Reativas de Oxigênio/metabolismo , Rotíferos/metabolismo , Rotíferos/fisiologia , Água do Mar/química , Natação
10.
Toxicol Lett ; 332: 118-129, 2020 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-32659471

RESUMO

Silver-based antimicrobials are widely used topically to treat infections associated with multi-drug resistant (MDR) pathogens. Expanding this topical use to aerosols to treat lung infections requires understanding and preventing silver toxicity in the respiratory tract. A key mechanism resulting in silver-induced toxicity is the production of reactive oxygen species (ROS). In this study, we have verified ROS generation in silver-treated bronchial epithelial cells prompting evaluation of three antioxidants, N-acetyl cysteine (NAC), ascorbic acid, and melatonin, to identify potential prophylactic agents. Among them, NAC was the only candidate that abrogated the ROS generation in response to silver acetate exposure resulting in the rescue of these cells from silver-associated toxicity. Further, this protective effect directly translated to preservation of metabolic activity, as demonstrated by the normal levels of citric acid cycle metabolites in NAC-pretreated silver acetate-exposed cells. Because the citric acid cycle remained functional, silver-exposed cells pre-incubated with NAC demonstrated significantly higher levels of adenosine triphosphate levels compared with NAC-free controls. Moreover, we found that this prodigious capacity of NAC to rescue silver acetate-exposed cells was due not only to its antioxidant activity, but also to its ability to directly bind silver. Despite binding to silver, NAC did not alter the antimicrobial activity of silver acetate.


Assuntos
Acetilcisteína/farmacologia , Antibacterianos/farmacologia , Depuradores de Radicais Livres/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Prata/farmacologia , Prata/toxicidade , Acetatos/farmacologia , Trifosfato de Adenosina/metabolismo , Ácido Ascórbico/farmacologia , Linhagem Celular , Cromatografia Gasosa-Espectrometria de Massas , Glutationa/metabolismo , Humanos , Melatonina/farmacologia , Testes de Sensibilidade Microbiana , Compostos de Prata/farmacologia , Superóxidos/metabolismo
11.
Toxicol Lett ; 332: 146-154, 2020 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-32683294

RESUMO

Occludin is an important tight junction (TJ) protein in pulmonary epithelial cells. In this study, we identified changes in occludin in arsenic-induced lung injury in vivo and in vitro. Upon intratracheal instillation with arsenic trioxide (As2O3) at a daily dose of 30 µg/kg for 1 week, levels of occludin mRNA and protein expression decreased significantly in mouse lung tissue. Levels of occludin mRNA and protein expression in BEAS-2B cells were reduced upon exposure to As2O3 in a concentration- and time-dependent manner. In addition, exposure to As2O3 significantly increased expression of p-p38, p-ERK1/2, p-ELK1, and MLCK in mouse lung tissue and BEAS-2B cells. Treatment with As2O3 induced oxidative stress in mouse lung tissue and BEAS-2B cells. In BEAS-2B cells, exposure to As2O3 reduced transepithelial resistance, which was partially restored with N-acetyl-cysteine (NAC) treatment. Reduced expression of occludin mRNA and protein induced by As2O3 was entirely restored with NAC and resveratrol. However, SB203580, PD98059, and ML-7 partially blocked As2O3-induced occludin reduction in BEAS-2B cells. These results indicate that As2O3 inhibits occludin expression in vivo and in vitro at least partially via the ROS/ERK/ELK1/MLCK and ROS/p38 MAPK signaling pathways.


Assuntos
Arsenitos/toxicidade , Pulmão/metabolismo , Ocludina/biossíntese , Transdução de Sinais/efeitos dos fármacos , Animais , Linhagem Celular , Regulação para Baixo/efeitos dos fármacos , Glutationa/metabolismo , Humanos , Pulmão/efeitos dos fármacos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Ocludina/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Peptídeos/efeitos dos fármacos , Peptídeos/metabolismo , Espécies Reativas de Oxigênio , Superóxido Dismutase/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/efeitos dos fármacos
12.
Chem Biol Interact ; 328: 109193, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-32668205

RESUMO

Embryonic studies have demonstrated the neurotoxic, teratogenic, and neurobehavioral toxicity of ethanol (EtOH). Although multiple mechanisms may contribute to these effects, oxidative stress has been described as the major damage pathway. In this regard, natural antioxidants have the potential to counteract oxidative stress-induced cellular damage. Therefore, the present study aimed to investigate the potential protective role of 24-epibrassinolide (24-EPI), a natural brassinosteroid with proved antioxidant properties, in EtOH-induced teratogenic effects during early zebrafish development. Embryos (~2 h post-fertilization - hpf) were exposed to 1 % EtOH, co-exposed to 24-EPI (0.01, 0.1 and 1 µM) and to 24-EPI alone (1 µM) for 24 h. Following exposure, biochemical evaluations were made at 26 hpf, developmental analysis was made throughout the embryo-larval period, and behavioural responses were evaluated at 120 hpf. Exposure to 1 % EtOH caused an increase in the number of malformations, which were diminished by 24-EPI. In addition, EtOH induced an accumulation of GSSG and consequent reduction of GSH:GSSG ratio, indicating the involvement of oxidative mechanisms in the EtOH-induced effects. These were reverted by 24-EPI as proved by the GSSG levels and GSH:GSSG ratio that returned to control values. Furthermore, exposure to EtOH resulted in behavioural deficits at 120 hpf as observed by the disrupted response to an aversive stimulus, suggesting the involvement of neurotoxic mechanisms. 24-EPI restored the behavioural deficits observed in a dose-dependent manner. The absence of effects in the embryos exposed solely to 24-EPI showed its safety during the exposure period. In conclusion, EtOH caused developmental teratogenicity and behavioural toxicity by inducing glutathione changes, which were prevented by 24-EPI.


Assuntos
Comportamento Animal , Brassinosteroides/farmacologia , Embrião não Mamífero/patologia , Etanol/toxicidade , Substâncias Protetoras/farmacologia , Esteroides Heterocíclicos/farmacologia , Teratogênese/efeitos dos fármacos , Peixe-Zebra/embriologia , Animais , Aprendizagem da Esquiva/efeitos dos fármacos , Comportamento Animal/efeitos dos fármacos , Embrião não Mamífero/anormalidades , Embrião não Mamífero/efeitos dos fármacos , Glutationa/metabolismo , Larva/efeitos dos fármacos , Comportamento Social
13.
Chem Biol Interact ; 328: 109197, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-32710900

RESUMO

The present study was undertaken to assess the effect of imatinib mesylate; a tyrosine kinase inhibitor and a well-known anticancer with numerous medical benefits on blood sugar levels, insulin, and glucagon secretion in an experimental model of STZ-induced diabetes mellitus. Type 1 diabetes mellitus (T1DM) was induced by a single I.P. injection of Streptozotocin (STZ) (50 mg/kg) in male Sprague-Dawley rats. Daily oral imatinib (10 mg/kg) and (20 mg/kg) for 4 weeks induced a significant attenuation in signs of DM in rats reflected in their assessed lab values. Biomarkers of cell injury, tissue necrosis, and apoptosis; caspase-3 were significantly reduced with imatinib treatment. Furthermore, pancreatic antioxidants defenses of which; superoxide dismutase (SOD) and catalase activities, reduced glutathione (GSH) concentration, and total antioxidant capacity have significantly improved with a simultaneous reduction in malondialdehyde (MDA) content. Histopathologically, imatinib treatment was associated with a minimal pancreatic injury and marked restoration of insulin content in ß-cells. Moreover, imatinib treatment revealed a significant reduction in the infiltration of macrophages in ß-cells. Imatinib's ameliorative impact on DM may be attributed to it's mediated protection and preservation of pancreatic ß-cells function and the improvement in serum insulin levels and hence the improvement of blood glucose and overall glycemic control.


Assuntos
Diabetes Mellitus Experimental/patologia , Mesilato de Imatinib/farmacologia , Células Secretoras de Insulina/metabolismo , Administração Oral , Animais , Antígenos CD/metabolismo , Antígenos de Diferenciação Mielomonocítica/metabolismo , Antioxidantes/metabolismo , Biomarcadores/sangue , Glicemia/metabolismo , Peso Corporal/efeitos dos fármacos , Caspase 3/metabolismo , Catalase/metabolismo , Diabetes Mellitus Experimental/sangue , Modelos Animais de Doenças , Glucagon/sangue , Glutationa/metabolismo , Insulina/sangue , Células Secretoras de Insulina/efeitos dos fármacos , Masculino , Malondialdeído/metabolismo , Tamanho do Órgão/efeitos dos fármacos , Oxirredução , Estresse Oxidativo/efeitos dos fármacos , Ratos Sprague-Dawley , Estreptozocina , Superóxido Dismutase/metabolismo
14.
Artigo em Inglês | MEDLINE | ID: mdl-32656654

RESUMO

Nitric oxide (NO) being a signaling molecule inside the plant cells, play significant role in signaling cascades and protection against environmental stresses. However, the protective role of NO in alleviating As toxicity in rice plants is currently not available. In the present study, the level of NO, nitrogen (N), inorganic N (nitrate, ammonium), thiols {TT (Total thiols), NPT (Nonprotein thiol)} and AAs contents along with N assimilating enzymes (NR, GDH, GOGAT) were analyzed after exposure of AsIII/NO treatment alone, and in combination. NO supplementation enhanced the content of N, inorganic N & thiol contents, NR, GOGAT activities, when compared with AsIII exposure alone. In AsIII exposed rice seedlings, content of AAs (except His, Arg, Met) reduced over the control, while supplementation of SNP improved AAs contents, compared to AsIII treatment alone. In conclusion, rice seedlings supplemented with NO tolerate the AsIII toxicity by reducing the N related parameters, thiol contents, altering the AA profile and enhanced the nutritional quality by increasing EAAs (essential amino acids) and NEAAs (non-essential amino acids).


Assuntos
Aminoácidos/metabolismo , Arsênico/efeitos adversos , Óxido Nítrico/metabolismo , Nitrogênio/metabolismo , Oryza/metabolismo , Poluentes do Solo/efeitos adversos , Compostos de Sulfidrila/metabolismo , Relação Dose-Resposta a Droga , Glutationa/metabolismo , Óxido Nítrico/administração & dosagem , Oryza/efeitos dos fármacos , Estresse Fisiológico
15.
Ecotoxicol Environ Saf ; 203: 110978, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32678757

RESUMO

In this study, hydroponic experiments were conducted to elucidate mechanism(s) that are associated with differential effects of low (5 µM) and high (25 µM) dose of cadmium (Cd) stress in tomato. Furthermore, emphasis has also been focused on any involvement of endogenous hydrogen sulfide (H2S) in differential behaviour of low and high doses of Cd stress. At low dose of Cd, root growth i.e. root fresh weight, length and fitness did not significantly alter when compared to the control seedlings. Though at low dose of Cd, cellular accumulation of Cd was slightly increased but this was accompanied by higher endogenous H2S and phytochelatins, L-cysteine desulfhydrase (DES) activity, activities of glutathione biosynthetic and AsA-GSH cycle enzymes, and maintained redox status of ascorbate and glutathione. However, addition of hypotaurine (HT, a scavenger of H2S) resulted in greater toxicity, even at low dose of Cd, and these responses resembled with higher dose of Cd stress such as greater decline in root growth, endogenous H2S and phytochelatins, activities of DES, glutathione biosynthesis and AsA-GSH cycle enzymes, disturbed redox status of ascorbate and glutathione which collectively led to higher oxidative stress in tomato roots. Moreover, addition of HT with higher dose of Cd also further enhanced its toxicity. Collectively, the results showed that differential behaviour of low and high dose of Cd stress is mediated by differential regulation of biochemical attributes in which endogenous H2S has a crucial role.


Assuntos
Cádmio/toxicidade , Sulfeto de Hidrogênio/metabolismo , Lycopersicon esculentum/efeitos dos fármacos , Fitoquelatinas/metabolismo , Raízes de Plantas/efeitos dos fármacos , Poluentes do Solo/toxicidade , Ácido Ascórbico/metabolismo , Glutationa/metabolismo , Lycopersicon esculentum/crescimento & desenvolvimento , Lycopersicon esculentum/metabolismo , Oxirredução , Estresse Oxidativo/efeitos dos fármacos , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Plântula/efeitos dos fármacos , Plântula/crescimento & desenvolvimento , Plântula/metabolismo
16.
PLoS One ; 15(7): e0236507, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32730281

RESUMO

In air-breathing fish a reduction of gill surface area reduces the danger of losing oxygen taken up in the air-breathing organ (ABO) to hypoxic water, but it also reduces the surface area available for ion exchange, so that ion regulation may at least in part be transferred to other organs, like the kidney or the gut. In the air-breathing Arapaima gigas, gill lamellae regress as development proceeds, and starting as a water-breathing embryo Arapaima turns into an obligate air-breathing fish with proceeding development, suggesting that ion regulation is shifted away from the gills as the fish grows. In Arapaima the kidney projects medially into the ABO and thus, probably a unique situation among fishes, is in close contact to the gas of the ABO. We therefore hypothesized that the kidney would be predestined to adopt an increased importance for ion homeostasis, because the elevated ATP turnover connected to ion transport can easily be met by aerobic metabolism based on the excellent oxygen supply directly from the ABO. We also hypothesized that in gill tissue the reduced ion regulatory activity should result in a reduced metabolic activity. High metabolic activity and exposure to high oxygen tensions are connected to the production of reactive oxygen species (ROS), therefore the tissues exposed to these conditions should have a high ROS defense capacity. Using in vitro studies, we assessed metabolic activity and ROS production of gill, kidney and ABO tissue, and determined the activity of ROS degrading enzymes in small (~ 5g, 2-3 weeks old) and larger (~ 670 g, 3-4 months old) A. gigas. Comparing the three tissues revealed that kidney tissue oxygen uptake by far exceeded the uptake measured in gill tissue or ABO. ROS production was particularly high in gill tissue, and all three tissues had a high capacity to degrade ROS. Gill tissue was characterized by high activities of enzymes involved in the glutathione pathway to degrade ROS. By contrast, the tissues of the ABO and in particular the kidney were characterized by high catalase activities, revealing different, tissue-specific strategies in ROS defense in this species. Overall the differences in the activity of cells taken from small and larger fish were not as pronounced as expected, while at the tissue level the metabolic activity of kidney cells by far exceeded the activity of ABO and gill cells.


Assuntos
Peixes/fisiologia , Consumo de Oxigênio/fisiologia , Espécies Reativas de Oxigênio/metabolismo , Animais , Brasil , Catalase/metabolismo , Brânquias/enzimologia , Brânquias/metabolismo , Glutationa/metabolismo , Glutationa Peroxidase/metabolismo , Rim/metabolismo , Mitocôndrias/metabolismo , Superóxido Dismutase/metabolismo
18.
Proc Natl Acad Sci U S A ; 117(32): 19228-19236, 2020 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-32703810

RESUMO

The ATP-binding cassette (ABC) transporter of mitochondria (Atm1) mediates iron homeostasis in eukaryotes, while the prokaryotic homolog from Novosphingobium aromaticivorans (NaAtm1) can export glutathione derivatives and confer protection against heavy-metal toxicity. To establish the structural framework underlying the NaAtm1 transport mechanism, we determined eight structures by X-ray crystallography and single-particle cryo-electron microscopy in distinct conformational states, stabilized by individual disulfide crosslinks and nucleotides. As NaAtm1 progresses through the transport cycle, conformational changes in transmembrane helix 6 (TM6) alter the glutathione-binding site and the associated substrate-binding cavity. Significantly, kinking of TM6 in the post-ATP hydrolysis state stabilized by MgADPVO4 eliminates this cavity, precluding uptake of glutathione derivatives. The presence of this cavity during the transition from the inward-facing to outward-facing conformational states, and its absence in the reverse direction, thereby provide an elegant and conceptually simple mechanism for enforcing the export directionality of transport by NaAtm1. One of the disulfide crosslinked NaAtm1 variants characterized in this work retains significant glutathione transport activity, suggesting that ATP hydrolysis and substrate transport by Atm1 may involve a limited set of conformational states with minimal separation of the nucleotide-binding domains in the inward-facing conformation.


Assuntos
Transportadores de Cassetes de Ligação de ATP/química , Proteínas de Bactérias/química , Sphingomonadaceae/metabolismo , Transportadores de Cassetes de Ligação de ATP/genética , Transportadores de Cassetes de Ligação de ATP/metabolismo , Trifosfato de Adenosina/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Sítios de Ligação , Cristalografia por Raios X , Glutationa/química , Glutationa/metabolismo , Ferro/metabolismo , Domínios Proteicos , Sphingomonadaceae/química , Sphingomonadaceae/genética
19.
Aquat Toxicol ; 225: 105552, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32615475

RESUMO

There is scarce investigation addressing interpopulation tolerance responses to address the influence of a history of chronic stress exposure, as that occurring in polluted environments, in photoautotrophs. We evaluated ecophysiological (photosynthetic activity) and metabolic (oxidative stress and damage) responses of two populations of green macroalga Ulva compressa from polluted (Ventanas) and non-polluted (Cachagua) localions of central Chile, and exposed to controlled hypersalinity conditions of 32 (control), 42, 62 and 82 psu (practical salinity units) for 6 h, 48 h and 6 d. Both primary production (ETRmax) and photosynthetic efficiency (αETR) were generally higher in the population from Cachagua compared to Ventanas at all times and salinities. Moreover, at most experimental times and salinities the population from Ventanas had greater levels of H2O2 and lipid peroxidation that individuals from Cachagua. Total ascorbate was higher in the population of Cachagua than Ventanas at 42 and 82 psu after 6 and 48 h, respectively, while at 6 d concentrations were similar between both populations at all salinities. Total glutathione was greater in both populations after 6 h at all salinities, but at 48 h its concentrations were higher only in the population from Cachagua, a trend that was maintained at 6 d under 82 psu only. Reduced and oxidized ascorbate (ASC and DHA, respectively) and glutathione (GSH and GSSG, respectively) demonstrated similar patterns between U. compressa populations, with an increase oxidation with greater salinities but efficient recycling to maintain sufficient batch of ASC and GSH. When assessing the expression of antioxidant enzymes catalase (CAT), superoxide dismutase (SOD) and dehydroascorbate reductase (DHAR), while the population of Ventanas displayed a general trend of upregulation with increasing salinities along the experiments, U. compressa from Cachagua revealed patterns of downregulation. Results demonstrated that although both populations were still viable after the applied hypersalinities during all experimental times, biological performance was usually more affected in the population from the Ventanas than Cachagua, likely due to a depressed baseline metabolism after a long history of exposition to environmental pollution.


Assuntos
Ulva/fisiologia , Poluentes Químicos da Água/toxicidade , Antioxidantes/metabolismo , Ácido Ascórbico/metabolismo , Catalase/metabolismo , Chile , Poluição Ambiental , Glutationa/metabolismo , Peróxido de Hidrogênio/metabolismo , Peroxidação de Lipídeos , Oxirredução , Estresse Oxidativo , Salinidade , Alga Marinha/metabolismo , Superóxido Dismutase/metabolismo , Ulva/enzimologia
20.
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
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