RESUMEN

Canopy shade enhances the activity of PHYTOCHROME INTERACTING FACTORs (PIFs) to boost auxin synthesis in the cotyledons. Auxin, together with local PIFs and their positive regulator CONSTITUTIVELY PHOTOMORPHOGENIC 1 (COP1), promotes hypocotyl growth to facilitate access to light. Whether shade alters the cellular redox status thereby affecting growth responses, remains unexplored. Here, we show that, under shade, high auxin levels increased reactive oxygen species and nitric oxide accumulation in the hypocotyl of Arabidopsis. This nitroxidative environment favored the promotion of hypocotyl growth by COP1 under shade. We demonstrate that COP1 is S-nitrosylated, particularly under shade. Impairing this redox regulation enhanced COP1 degradation by the proteasome and diminished the capacity of COP1 to interact with target proteins and to promote hypocotyl growth. Disabling this regulation also generated transversal asymmetries in hypocotyl growth, indicating poor coordination among different cells, which resulted in random hypocotyl bending and predictably low ability to compete with neighbors. These findings highlight the significance of redox signaling in the control of diffuse growth during shade avoidance.

Asunto(s)

Proteínas de Arabidopsis , Arabidopsis , Hipocótilo , Especies Reactivas de Oxígeno , Ubiquitina-Proteína Ligasas , Arabidopsis/metabolismo , Arabidopsis/crecimiento & desarrollo , Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Especies Reactivas de Oxígeno/metabolismo , Hipocótilo/crecimiento & desarrollo , Hipocótilo/metabolismo , Ubiquitina-Proteína Ligasas/metabolismo , Óxido Nítrico/metabolismo , Ácidos Indolacéticos/metabolismo , Luz , Regulación de la Expresión Génica de las Plantas/efectos de la radiación , Oxidación-Reducción , Transducción de Señal

RESUMEN

Genetic and environmental factors have been linked with neurodegeneration, especially in the elderly. Yet, efforts to impede neurodegenerative processes have at best addressed symptoms instead of underlying pathologies. The gap in the understanding of neuro-behavioral plasticity is consistent from insects to mammals, and cockroaches have been proven to be effective models for studying the toxicity mechanisms of various chemicals. We therefore used head injection of 74 and 740 nmol STZ in Nauphoeta cinerea to elucidate the mechanisms of chemical-induced neurotoxicity, as STZ is known to cross the blood-brain barrier. Neurolocomotor assessment was carried out in a new environment, while head homogenate was used to estimate metabolic, neurotransmitter and redox activities, followed by RT-qPCR validation of relevant cellular signaling. STZ treatment reduced the distance and maximum speed travelled by cockroaches, and increased glucose levels while reducing triglyceride levels in neural tissues. The activity of neurotransmitter regulators - AChE and MAO was exacerbated, with concurrent upregulation of glucose sensing and signaling, and increased mRNA levels of redox regulators and inflammation-related genes. Consequently, STZ neurotoxicity is conserved in insects, with possible implications for using N. cinerea to target the multi-faceted mechanisms of neurodegeneration and test potential anti-neurodegenerative agents.

Asunto(s)

Acetilcolinesterasa , Monoaminooxidasa , Oxidación-Reducción , Estreptozocina , Animales , Monoaminooxidasa/metabolismo , Oxidación-Reducción/efectos de los fármacos , Acetilcolinesterasa/metabolismo , Cucarachas , Encéfalo/metabolismo , Encéfalo/efectos de los fármacos , Conducta Animal/efectos de los fármacos

RESUMEN

Tributyltin (TBT) is an organotin compound that has several adverse health effects, including the development of obesity. Although obesity is strongly associated with adipose redox imbalance, there is a lack of information on whether TBT promotes a pro-oxidative environment in WAT. Thus, adult male Wistar rats were randomly exposed to either vehicle (ethanol 0.4%) or TBT (1000 ng/kg) for 30 days. Body and fat pad masses, visceral fat morphology, lipid peroxidation, protein carbonylation, redox status markers, and catalase activity were evaluated. TBT promoted increased adiposity and visceral fat, with hypertrophic adipocytes, but did not alter body mass and subcutaneous fat. ROS production and lipid peroxidation were elevated in TBT group, as well as catalase protein expression and activity, although protein oxidation and glutathione peroxidase protein expression remained unchanged. In conclusion, this is the first study to demonstrate that subacute TBT administration leads to visceral adipose redox imbalance, with increased oxidative stress. This enlights the understanding of the metabolic toxic outcomes of continuous exposure to TBT in mammals.

Asunto(s)

Adiposidad , Catalasa , Grasa Intraabdominal , Peroxidación de Lípido , Oxidación-Reducción , Estrés Oxidativo , Ratas Wistar , Compuestos de Trialquiltina , Animales , Masculino , Compuestos de Trialquiltina/toxicidad , Oxidación-Reducción/efectos de los fármacos , Grasa Intraabdominal/efectos de los fármacos , Grasa Intraabdominal/metabolismo , Adiposidad/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , Peroxidación de Lípido/efectos de los fármacos , Catalasa/metabolismo , Ratas , Especies Reactivas de Oxígeno/metabolismo , Tejido Adiposo Blanco/metabolismo , Tejido Adiposo Blanco/efectos de los fármacos , Carbonilación Proteica/efectos de los fármacos , Glutatión Peroxidasa/metabolismo

RESUMEN

OBJECTIVE: Obesity represents a significant global health challenge characterized by chronic low-grade inflammation and metabolic dysregulation. The hypothalamus, a key regulator of energy homeostasis, is particularly susceptible to obesity's deleterious effects. This study investigated the role of the immunoproteasome, a specialized proteasomal complex implicated in inflammation and cellular homeostasis, during metabolic diseases. METHODS: The levels of the immunoproteasome ß5i subunit were analyzed by immunostaining, western blotting, and proteasome activity assay in mice fed with either a high-fat diet (HFD) or a regular diet (CHOW). We also characterized the impact of autophagy inhibition on the levels of the immunoproteasome ß5i subunit and the activation of the AKT pathway. Finally, through confocal microscopy, we analyzed the contribution of ß5i subunit inhibition on mitochondrial function by flow cytometry and mitophagy assay. RESULTS: Using an HFD-fed obese mouse model, we found increased immunoproteasome levels in hypothalamic POMC neurons. Furthermore, we observed that palmitic acid (PA), a major component of saturated fats found in HFD, increased the levels of the ß5i subunit of the immunoproteasome in hypothalamic neuronal cells. Notably, the increase in immunoproteasome expression was associated with decreased autophagy, a critical cellular process in maintaining homeostasis and suppressing inflammation. Functionally, PA disrupted the insulin-glucose axis, leading to reduced AKT phosphorylation and increased intracellular glucose levels in response to insulin due to the upregulation of the immunoproteasome. Mechanistically, we identified that the protein PTEN, a key regulator of insulin signaling, was reduced in an immunoproteasome-dependent manner. To further investigate the potential therapeutic implications of these findings, we used ONX-0914, a specific immunoproteasome inhibitor. We demonstrated that this inhibitor prevents PA-induced insulin-glucose axis imbalance. Given the interplay between mitochondrial dysfunction and metabolic disturbances, we explored the impact of ONX-0914 on mitochondrial function. Notably, ONX-0914 preserved mitochondrial membrane potential and attenuated mitochondrial ROS production in the presence of PA. Moreover, we found that ONX-0914 reduced mitophagy in the presence of PA. CONCLUSIONS: Our findings strongly support the pathogenic involvement of the immunoproteasome in hypothalamic neurons in the context of HFD-induced obesity and metabolic disturbances. Targeting the immunoproteasome highlights a promising therapeutic strategy to mitigate the detrimental effects of obesity on the insulin-glucose axis and cellular homeostasis. This study provides valuable insights into the mechanisms driving obesity-related metabolic diseases and offers potential avenues for developing novel therapeutic interventions.

Asunto(s)

Dieta Alta en Grasa , Hipotálamo , Ratones Endogámicos C57BL , Neuronas , Obesidad , Complejo de la Endopetidasa Proteasomal , Animales , Dieta Alta en Grasa/efectos adversos , Ratones , Hipotálamo/metabolismo , Obesidad/metabolismo , Neuronas/metabolismo , Neuronas/efectos de los fármacos , Complejo de la Endopetidasa Proteasomal/metabolismo , Masculino , Enfermedades Metabólicas/metabolismo , Enfermedades Metabólicas/etiología , Oligopéptidos

RESUMEN

Zinc (Zn) is an essential trace element; it exhibits a plethora of physiological properties and biochemical functions. It plays a pivotal role in regulating the cell cycle, apoptosis, and DNA organization, as well as in protein, lipid, and carbohydrate metabolism. Among other important processes, Zn plays an essential role in reproductive health. The ZIP and ZnT proteins are responsible for the mobilization of Zn within the cell. Zn is an inert antioxidant through its interaction with a variety of proteins and enzymes to regulate the redox system, including metallothioneins (MTs), metalloenzymes, and gene regulatory proteins. The role of Zn in the reproductive system is of great importance; processes, such as spermatogenesis and sperm maturation that occur in the testicle and epididymis, respectively, depend on this element for their development and function. Zn modulates the synthesis of androgens, such as testosterone, for these reproductive processes, so Zn deficiency is related to alterations in sperm parameters that lead to male infertility.

Asunto(s)

Epidídimo , Testículo , Zinc , Masculino , Zinc/metabolismo , Epidídimo/metabolismo , Humanos , Testículo/metabolismo , Animales , Espermatogénesis , Espermatozoides/metabolismo , Infertilidad Masculina/metabolismo , Maduración del Esperma/fisiología

RESUMEN

Potentially harmful element (PHE) bioavailability is important to environmental contamination and must be checked under several soil conditions. This study aimed to assess Fe, Mn, and PHE uptake by rice (Oryza sativa) grown on flooded and non-flooded Fe tailings collected from the Doce River basin after its collapse in Brazil. After 65 days of sowing, shoots and roots were harvested to determine PHE concentrations. The mean concentrations of Mn in shoots and Fe in the roots of rice grown on the flooded tailings were 2140 mg kg-1 and 15,219 mg kg-1, respectively. Mn was extensively translocated from roots to shoots (translocation factor (TF) = 2). Conversely, Fe accumulated in roots (TF = 0.015) and caused morphological damage to this rice organ. The application of macro and micronutrients lessened Fe toxicity in the roots of rice cultivated on the flooded tailings. The flooding of tailings influenced more Fe accumulation than Mn accumulation by rice plants. The PHE Ag, As, Cd, Ni, Hg, Pb, and Sb exhibited low total concentrations (maximum of 9 mg kg-1 for Ni and a minimum of 0.2 mg kg-1 for Cd, Hg, and Sb), and it was not observed an increase in their availability under tailings flooding conditions.

Asunto(s)

Hierro , Manganeso , Oryza , Ríos , Brasil , Hierro/metabolismo , Inundaciones , Contaminantes del Suelo/metabolismo , Monitoreo del Ambiente , Raíces de Plantas/metabolismo

RESUMEN

Most redox processes that break/form bonds involve net 2e- changes, and many are coupled to protons. Yet most proton-coupled electron transfer (PCET) studies focus on 1e-/1H+ reactions. Reported here is a family of molecular models that undergo tunable 2e-/2H+ redox changes. Complexes [(X2bpy)RuII(en*)2](PF6)2 and [(X2bpy)RuIV(en*-H)2](PF6)2 have been synthesized with bpy=2,2'-bipyridine with 4,4'-subtitutions X=-NMe2, -OMe, -Me, -H, -CF3; and en*=2,3-dimethyl-2,3-butanediamine. They have been characterized by IR, UV-vis, and NMR spectroscopies, XRD, electrochemistry, mass spectrometry, DFT and (TD)DFT computations. The introduction of electron-withdrawing and donating groups at the 4,4'-position of the bpy ligand affects the complexes' redox potentials, pKa's, and Bond Dissociation Free Energies (BDFEs) of the N-H bonds in the en* ligands. The average BDFEs for the overall 2e-/2H+ PCET span over 5 kcal/mol. Notably, these complexes all show marked potential inversion over an extended range, ΔpKa>25 units and ΔE0>1.4 V. Potential inversion remains despite the electronic influence of bpy's substitutions which regulate N-H properties several bonds apart by trans-effect over dπ-molecular orbitals at the Ru center. The experimental and computational results presented in this work support the presence of strong coupling between electrons and protons, for modelling insights of 2e-/2H+ transfer reactivity.

RESUMEN

The maternal diet and egg incubation temperature are some of the factors that can influence the embryonic development and performance of the newly chicks at 15 d of age. This study evaluated the effects of adding a blend of organic acids, essential oils, curcumin, tannins, vitamin E, and zinc microencapsulated in to the diet of female quails (Coturnix coturnix japonica) on their productive, reproductive performance and redox parameters of their eggs and the interaction of maternal diet × incubation temperature on embryo (E16 and E18) and chicks development. At 98 d of age, 64 female quails with a mean body weight of 150 g ± 0.5 were distributed into two treatments: a Basal diet or a diet supplemented with blend (Sannimix). The eggs from each female were incubated at 37.5°C (Control) and 38.5°C (High Temperature) throughout the incubation period. After hatching, chicks were distributed in a 2 (maternal diet) × 2 (incubation temperature) factorial design. Female quails supplemented with Sannimix showed better productive and reproductive performance and produced higher-quality embryos. Their offspring had greater weight at hatch and at 15 d of age. The eggs and offspring of supplemented with Sannimix female quails showed better oxidative stability. At E16 and E18, High Temperature increased yolk sac utilization and gene expression of the growth hormone receptor (GHR). At E16, embryos from supplemented with Sannimix female quail had higher expression of insulin-like growth factor type I (IGFI) and heat shock protein 70 kDa genes. At 15 d of age, highest expression of the GHR and IGFI genes was observed in chicks from female quails fed the Sannimix diet, regardless of incubation temperature. Regarding the maternal diet × incubation temperature an improved result was observed for chicks from female quails fed with Sannimix even when eggs are exposed to High Temperature during the incubation. The supplementation of quail diets with blend Sannimix improves productive and reproductive performance, egg quality and their embryos, as well as their offspring quality.

Asunto(s)

Alimentación Animal , Coturnix , Curcumina , Dieta , Suplementos Dietéticos , Aceites Volátiles , Vitamina E , Zinc , Animales , Alimentación Animal/análisis , Dieta/veterinaria , Femenino , Suplementos Dietéticos/análisis , Coturnix/crecimiento & desarrollo , Aceites Volátiles/administración & dosificación , Vitamina E/administración & dosificación , Zinc/administración & dosificación , Zinc/metabolismo , Curcumina/administración & dosificación , Curcumina/farmacología , Taninos/administración & dosificación , Temperatura , Reproducción/efectos de los fármacos , Fenómenos Fisiológicos Nutricionales de los Animales/efectos de los fármacos , Desarrollo Embrionario/efectos de los fármacos

RESUMEN

Glioblastoma (GBM) is an aggressive form of cancer affecting the Central Nervous System (CNS) of thousands of people every year. Redox alterations have been shown to play a key role in the development and progression of these tumors as Reactive Oxygen Species (ROS) formation is involved in the modulation of several signaling pathways, transcription factors, and cytokine formation. The second-generation oral alkylating agent temozolomide (TMZ) is the first-line chemotherapeutic drug used to treat of GBM, though patients often develop primary and secondary resistance, reducing its efficacy. Antioxidants represent promising and potential coadjutant agents as they can reduce excessive ROS formation derived from chemo- and radiotherapy, while decreasing pharmacological resistance. S-allyl-cysteine (SAC) has been shown to inhibit the proliferation of several types of cancer cells, though its precise antiproliferative mechanisms remain poorly investigated. To date, SAC effects have been poorly explored in GBM cells. Here, we investigated the effects of SAC in vitro, either alone or in combination with TMZ, on several toxic and modulatory endpoints-including oxidative stress markers and transcriptional regulation-in two glioblastoma cell lines from rats, RG2 and C6, to elucidate some of the biochemical and cellular mechanisms underlying its antiproliferative properties. SAC (1-750 µM) decreased cell viability in both cell lines in a concentration-dependent manner, although C6 cells were more resistant to SAC at several of the tested concentrations. TMZ also produced a concentration-dependent effect, decreasing cell viability of both cell lines. In combination, SAC (1 µM or 100 µM) and TMZ (500 µM) enhanced the effects of each other. SAC also augmented the lipoperoxidative effect of TMZ and reduced cell antioxidant resistance in both cell lines by decreasing the TMZ-induced increase in the GSH/GSSG ratio. In RG2 and C6 cells, SAC per se had no effect on Nrf2/ARE binding activity, while in RG2 cells TMZ and the combination of SAC + TMZ decreased this activity. Our results demonstrate that SAC, alone or in combination with TMZ, exerts antitumor effects mediated by regulatory mechanisms of redox activity responses. SAC is also a safe drug for testing in other models as it produces non-toxic effects in primary astrocytes. Combined, these effects suggest that SAC affords antioxidant properties and potential antitumor efficacy against GBM.

RESUMEN

Unbalanced redox status and constitutive STAT3 activation are related to several aspects of tumor biology and poor prognosis, including metastasis and drug resistance. The triple-negative breast cancer (TNBC) is listed as the most aggressive and exhibits the worst prognosis among the breast cancer subtypes. Although the mechanism of reactive oxygen species (ROS) generation led to STAT3 activation is described, there is no data concerning the STAT3 influence on redox homeostasis in TNBC. To address the role of STAT3 signaling in redox balance, we inhibited STAT3 in TNBC cells and investigated its impact on total ROS levels, contents of hydroperoxides, nitric oxide (NO), and total glutathione (GSH), as well as the expression levels of 3-nitrotyrosine (3NT), nuclear factor (erythroid-derived 2)-like 2 (Nrf2), and nuclear factor kappa B (NF-κB)/p65. Our results indicate that ROS levels depend on the STAT3 activation, while the hydroperoxide level remained unchanged, and NO and 3NT expression increased. Furthermore, GSH levels, Nrf2, and NF-κB/p65 protein levels are decreased in the STAT3-inhibited cells. Accordingly, TNBC patients' data from TCGA demonstrated that both STAT3 mRNA levels and STAT3 signature are correlated to NF-κB/p65 and Nrf2 signatures. Our findings implicate STAT3 in controlling redox balance and regulating redox-related genes' expression in triple-negative breast cancer.

RESUMEN

Melanogenesis-stimulated B16-F10 cells enter in a quiescent state, present inhibited mitochondrial respiration and increased reactive oxygen species levels. These alterations suggest that these cells may be under redox signaling, allowing tumor survival. The aim of this study was to evaluate redox-modified proteins in B16-F10 cells after melanogenesis stimulation and rose bengal-photodynamic therapy (RB-PDT). A redox proteomics label-free approach based on the biotin switch assay technique with biotin-HPDP and N-ethylmaleimide was used to assess the thiol-oxidized protein profile. Aconitase was oxidized at Cys-448 and Cys-451, citrate synthase was oxidized at Cys-202 and aspartate aminotransferase (Got2) was oxidized at Cys-272 and Cys-274, exclusively after melanogenesis stimulation. After RB-PDT, only guanine nucleotide-binding protein subunit beta-2-like 1 (Gnb2l1) was oxidized (Cys-168). In contrast, melanogenesis stimulation followed by RB-PDT led to the oxidation of different cysteines in Gnb2l1 (Cys-153 and Cys-249). Besides that, glyceraldehyde-3-phosphate dehydrogenase (Gapdh) presented oxidation at Cys-245, peptidyl-prolyl cis-trans isomerase A (Ppia) was oxidized at Cys-161 and 5,6-dihydroxyindole-2-carboxylic acid oxidase (Tyrp1) was oxidized at Cys-65, Cys-30, and Cys-336 after melanogenesis stimulation followed by RB-PDT. The redox alterations observed in murine melanoma cells and identification of possible target proteins are of great importance to further understand tumor resistance mechanisms.

RESUMEN

Understanding the complex biological processes of cells in culture, particularly those related to metabolism, can be biased by culture conditions, since the choice of energy substrate impacts all of the main metabolic pathways. When glucose is replaced by galactose, cells decrease their glycolytic flux, working as an in vitro model of limited nutrient availability. However, the effect of these changes on related physiological processes such as redox control is not well documented, particularly in endothelial cells, where mitochondrial oxidation is considered to be low. We evaluated the differences in mitochondrial dynamics and function in endothelial cells exposed to galactose or glucose culture medium. We observed that cells maintained in galactose-containing medium show a higher mitochondrial oxidative capacity, a more fused mitochondrial network, and higher intercellular coupling. These factors are documented to impact the cellular response to oxidative stress. Therefore, we analyzed the levels of two main redox regulators and found that bovine aortic endothelial cells (BAEC) in galactose media had higher levels of FOXO3 and lower levels of Nrf2 than those in glucose-containing media. Thus, cultures of endothelial cells in a galactose-containing medium may provide a more suitable target for the study of in vitro mitochondrial-related processes than those in glucose-containing media; the medium deeply influences redox signaling in these cells.

RESUMEN

Ligand-protected gold clusters remain potential building blocks for envisaged molecular materials. The archetypal Au38(SR)24 cluster can be viewed as a robust template for the fusion of two Au25(SR)18 - cluster units, retaining a bi-icosahedral Au23 core. Via electrochemical properties, the overall charge state can be selectively tuned, enabling the access of 14 valence electron (ve) species featuring a single intercluster bond and nearby charge from -1 to +3, achieving related species bearing 15- to 11-ve with variable intercluster bond orders. Here, we explore the characteristics of intermediate intercluster bond orders in order to provide insights into the plausible electron communication between the constituent building blocks, with Au38(SR)24, as a representative template. Our results denote a small structural variation along -1 to +3 charge states, provided by the core-protecting ligand interaction, which is enhanced towards more oxidized species. The remaining unpaired electron from intermediate intercluster bond orders of 1.5 for Au38(SR)24 1-, 1.5 for Au38(SR)24 1+, and 2.5 for Au38(SR)24 3+, holds delocalized characteristics between the building block units, favoring electron communication for conductive and cooperative cluster aggregates. Such features are relevant for the formation of molecular electronic device applications, favoring the rationalization prior to engaging in explorative synthesis of larger ligand-protected cluster aggregates.

RESUMEN

Hypertrophic cardiomyopathy (HCM) is a heart condition characterized by cellular and metabolic dysfunction, with mitochondrial dysfunction playing a crucial role. Although the direct relationship between genetic mutations and mitochondrial dysfunction remains unclear, targeting mitochondrial dysfunction presents promising opportunities for treatment, as there are currently no effective treatments available for HCM. This review adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis Extension for Scoping Reviews guidelines. Searches were conducted in databases such as PubMed, Embase, and Scopus up to September 2023 using "MESH terms". Bibliographic references from pertinent articles were also included. Hypertrophic cardiomyopathy (HCM) is influenced by ionic homeostasis, cardiac tissue remodeling, metabolic balance, genetic mutations, reactive oxygen species regulation, and mitochondrial dysfunction. The latter is a common factor regardless of the cause and is linked to intracellular calcium handling, energetic and oxidative stress, and HCM-induced hypertrophy. Hypertrophic cardiomyopathy treatments focus on symptom management and complication prevention. Targeted therapeutic approaches, such as improving mitochondrial bioenergetics, are being explored. This includes coenzyme Q and elamipretide therapies and metabolic strategies like therapeutic ketosis. Understanding the biomolecular, genetic, and mitochondrial mechanisms underlying HCM is crucial for developing new therapeutic modalities.

Asunto(s)

Cardiomiopatía Hipertrófica , Mutación , Oxidación-Reducción , Transducción de Señal , Humanos , Cardiomiopatía Hipertrófica/genética , Cardiomiopatía Hipertrófica/metabolismo , Animales , Mitocondrias/metabolismo , Mitocondrias/genética , Estrés Oxidativo , Especies Reactivas de Oxígeno/metabolismo

RESUMEN

In response to the spread of artemisinin (ART) resistance, ART-based hybrid drugs were developed, and their activity profile was characterized against drug-sensitive and drug-resistant Plasmodium falciparum parasites. Two hybrids were found to display parasite growth reduction, stage-specificity, speed of activity, additivity of activity in drug combinations, and stability in hepatic microsomes of similar levels to those displayed by dihydroartemisinin (DHA). Conversely, the rate of chemical homolysis of the peroxide bonds is slower in hybrids than in DHA. From a mechanistic perspective, heme plays a central role in the chemical homolysis of peroxide, inhibiting heme detoxification and disrupting parasite heme redox homeostasis. The hybrid exhibiting slow homolysis of peroxide bonds was more potent in reducing the viability of ART-resistant parasites in a ring-stage survival assay than the hybrid exhibiting fast homolysis. However, both hybrids showed limited activity against ART-induced quiescent parasites in the quiescent-stage survival assay. Our findings are consistent with previous results showing that slow homolysis of peroxide-containing drugs may retain activity against proliferating ART-resistant parasites. However, our data suggest that this property does not overcome the limited activity of peroxides in killing non-proliferating parasites in a quiescent state.

Asunto(s)

Antimaláricos , Artemisininas , Plasmodium falciparum , Artemisininas/farmacología , Antimaláricos/farmacología , Plasmodium falciparum/efectos de los fármacos , Resistencia a Medicamentos/efectos de los fármacos , Microsomas Hepáticos/metabolismo , Humanos , Pruebas de Sensibilidad Parasitaria , Animales , Peróxidos/farmacología

RESUMEN

Heme is a prosthetic group of proteins involved in vital physiological processes. It participates, for example, in redox reactions crucial for cell metabolism due to the variable oxidation state of its central iron atom. However, excessive heme can be cytotoxic due to its prooxidant properties. Therefore, the control of intracellular heme levels ensures the survival of organisms, especially those that deal with high concentrations of heme during their lives, such as hematophagous insects. The export of heme initially attributed to the feline leukemia virus C receptor (FLVCR) has recently been called into question, following the discovery of choline uptake by the same receptor in mammals. Here, we found that RpFLVCR is a heme exporter in the midgut of the hematophagous insect Rhodnius prolixus, a vector for Chagas disease. Silencing RpFLVCR decreased hemolymphatic heme levels and increased the levels of intracellular dicysteinyl-biliverdin, indicating heme retention inside midgut cells. FLVCR silencing led to increased expression of heme oxygenase (HO), ferritin, and mitoferrin mRNAs while downregulating the iron importers Malvolio 1 and 2. In contrast, HO gene silencing increased FLVCR and Malvolio expression and downregulated ferritin, revealing crosstalk between heme degradation/export and iron transport/storage pathways. Furthermore, RpFLVCR silencing strongly increased oxidant production and lipid peroxidation, reduced cytochrome c oxidase activity, and activated mitochondrial biogenesis, effects not observed in RpHO-silenced insects. These data support FLVCR function as a heme exporter, playing a pivotal role in heme/iron metabolism and maintenance of redox balance, especially in an organism adapted to face extremely high concentrations of heme.

Asunto(s)

Hemo , Mitocondrias , Oxidación-Reducción , Rhodnius , Animales , Hemo/metabolismo , Rhodnius/metabolismo , Mitocondrias/metabolismo , Receptores Virales/metabolismo , Receptores Virales/genética , Virus de la Leucemia Felina/metabolismo , Proteínas de Insectos/metabolismo , Proteínas de Insectos/genética

RESUMEN

Type II pneumocytes are the target of the SARS-CoV-2 virus, which alters their redox homeostasis to increase reactive oxygen species (ROS). Melatonin (MT) has antioxidant proprieties and protects mitochondrial function. In this study, we evaluated whether treatment with MT compensated for the redox homeostasis alteration in serum from COVID-19 patients. We determined oxidative stress (OS) markers such as carbonyls, glutathione (GSH), total antioxidant capacity (TAC), thiols, nitrites (NO2-), lipid peroxidation (LPO), and thiol groups in serum. We also studied the enzymatic activities of glutathione peroxidase (GPx), glutathione-S-transferase (GST), reductase (GR), thioredoxin reductase (TrxR), extracellular superoxide dismutase (ecSOD) and peroxidases. There were significant increases in LPO and carbonyl quantities (p ≤ 0.03) and decreases in TAC and the quantities of NO2-, thiols, and GSH (p < 0.001) in COVID-19 patients. The activities of the antioxidant enzymes such as ecSOD, TrxR, GPx, GST, GR, and peroxidases were decreased (p ≤ 0.04) after the MT treatment. The treatment with MT favored the activity of the antioxidant enzymes that contributed to an increase in TAC and restored the lost redox homeostasis. MT also modulated glucose homeostasis, functioning as a glycolytic agent, and inhibited the Warburg effect. Thus, MT restores the redox homeostasis that is altered in COVID-19 patients and can be used as adjuvant therapy in SARS-CoV-2 infection.

Asunto(s)

Antioxidantes , Tratamiento Farmacológico de COVID-19 , COVID-19 , Homeostasis , Melatonina , Oxidación-Reducción , Estrés Oxidativo , SARS-CoV-2 , Melatonina/uso terapéutico , Melatonina/farmacología , Humanos , Oxidación-Reducción/efectos de los fármacos , COVID-19/metabolismo , COVID-19/virología , COVID-19/sangre , Homeostasis/efectos de los fármacos , Antioxidantes/metabolismo , Antioxidantes/uso terapéutico , Estrés Oxidativo/efectos de los fármacos , Masculino , Femenino , Persona de Mediana Edad , SARS-CoV-2/efectos de los fármacos , Peroxidación de Lípido/efectos de los fármacos , Anciano , Adulto , Especies Reactivas de Oxígeno/metabolismo , Glutatión/metabolismo , Glutatión/sangre

RESUMEN

Cancer development and progression are intimately related with post-translational protein modifications, e.g., highly reactive thiol moiety of cysteines enables structural rearrangements resulting in redox biological switches. In this context, redox proteomics techniques, such as 2D redox DIGE, biotin switch assay and OxIcat are fundamental tools to identify and quantify redox-sensitive proteins and to understand redox mechanisms behind thiol modifications. Given the great variability in redox proteomics protocols, problems including decreased resolution of peptides and low protein amounts even after enrichment steps may occur. Considering the biological importance of thiol's oxidation in melanoma, we adapted the biotin-switch assay technique for melanoma cells in order to overcome the limitations and improve coverage of detected proteins.

Asunto(s)

Biotina , Melanoma , Oxidación-Reducción , Proteómica , Proteómica/métodos , Melanoma/metabolismo , Melanoma/patología , Humanos , Línea Celular Tumoral , Biotina/química , Biotina/metabolismo , Compuestos de Sulfhidrilo/química , Compuestos de Sulfhidrilo/metabolismo

RESUMEN

PURPOSE: Considering that the combination of dasatinib and quercetin (D + Q) demonstrated a neuroprotective action, as well as that females experience a decline in hormonal levels during aging and this is linked to increased susceptibility to Alzheimer's disease, in this study we evaluated the effect of D + Q on inflammatory and oxidative stress markers and on acetylcholinesterase and Na+, K+-ATPase activities in brain of female mice. METHODS: Female C57BL/6 mice were divided in Control and D (5 mg/kg) + Q (50 mg/kg) treated. Treatment was administered via gavage for three consecutive days every two weeks starting at 30 days of age. The animals were euthanized at 6 months of age and at 14 months of age. RESULTS: Results indicate an increase in reactive species (RS), thiol content and lipid peroxidation followed by a reduction in nitrite levels and superoxide dismutase, catalase and glutathione S-transferase activity in the brain of control animals with age. D+Q protected against age-associated increase in RS and catalase activity reduction. Acetylcholinesterase activity was increased, while Na+, K+-ATPase activity was reduced at 14 months of age and D+Q prevented this reduction. CONCLUSION: These data demonstrate that D+Q can protect against age-associated neurochemical alterations in the female brain.

Asunto(s)

Acetilcolinesterasa , Senoterapéuticos , Ratas , Femenino , Ratones , Animales , Catalasa/metabolismo , Acetilcolinesterasa/metabolismo , Ratas Wistar , Ratones Endogámicos C57BL , Antioxidantes/farmacología , Estrés Oxidativo , Quercetina/farmacología , Encéfalo/metabolismo , Superóxido Dismutasa/metabolismo , Adenosina Trifosfatasas

RESUMEN

Mucopolysaccharidosis type II (MPS II; Hunter syndrome) is a lysosomal storage disease caused by mutations in the gene encoding the enzyme iduronate 2-sulfatase (IDS) and biochemically characterized by the accumulation of glycosaminoglycans (GAGs) in different tissues. It is a multisystemic disorder that presents liver abnormalities, the pathophysiology of which is not yet established. In the present study, we evaluated bioenergetics, redox homeostasis, and mitochondrial dynamics in the liver of 6-month-old MPS II mice (IDS-). Our findings show a decrease in the activity of α-ketoglutarate dehydrogenase and an increase in the activities of succinate dehydrogenase and malate dehydrogenase. The activity of mitochondrial complex I was also increased whereas the other complex activities were not affected. In contrast, mitochondrial respiration, membrane potential, ATP production, and calcium retention capacity were not altered. Furthermore, malondialdehyde levels and 2',7'-dichlorofluorescein oxidation were increased in the liver of MPS II mice, indicating lipid peroxidation and increased ROS levels, respectively. Sulfhydryl and reduced glutathione levels, as well as glutathione S-transferase, glutathione peroxidase (GPx), superoxide dismutase, and catalase activities were also increased. Finally, the levels of proteins involved in mitochondrial mass and dynamics were decreased in knockout mice liver. Taken together, these data suggest that alterations in energy metabolism, redox homeostasis, and mitochondrial dynamics can be involved in the pathophysiology of liver abnormalities observed in MPS II.