RESUMEN

ETHNOPHARMACOLOGICAL RELEVANCE: Gelsemium dynamized dilutions (GDD) are known as a remedy for a wide range of behavioral and psychological symptoms of depression and anxiety at ultra-low doses, yet the underlying mechanisms of the mode of action of G. sempervirens itself are not well understood. AIM OF THE STUDY: The present study was designed to examine the neuroprotective effects of Gelsemium preparations in counteracting stress-related mitochondrial dysfunctions in neuronal cells. MATERIALS AND METHODS: We started by studying how serum deprivation affects the mitochondrial functions of human neuroblastoma (SH-SY5Y) cells. Next, we looked into the potential of various Gelsemium dilutions to improve cell survival and ATP levels. After identifying the most effective dilutions, 3C and 5C, we tested their ability to protect SH-SY5Y cells from stress-induced mitochondrial deficits. We measured total and mitochondrial superoxide anion radicals using fluorescent dyes dihydroethidium (DHE) and the red mitochondrial superoxide indicator (MitoSOX). Additionally, we assessed total nitric oxide levels with 4,5-diaminofluorescein diacetate (DAF-2DA), examined the redox state using pRA305 cells stably transfected with a plasmid encoding a redox-sensitive green fluorescent protein, and analyzed mitochondrial network morphology using an automated high-content analysis device, Cytation3. Furthermore, we investigated bioenergetics by measuring ATP production with a bioluminescence assay (ViaLighTM HT) and evaluated mitochondrial respiration (OCR) and glycolysis (ECAR) using the Seahorse Bioscience XF24 Analyzer. Finally, we determined cell survival using an MTT reduction assay. RESULTS: Our research indicates that Gelsemium dilutions (3C and 5C) exhibited neuroprotective effects by: - Normalizing total and mitochondrial superoxide anion radicals and total nitric oxide levels. - Regulating the mitochondrial redox environment and mitochondrial networks morphology. - Increasing ATP generation as well as OCR and ECAR levels, thereby reducing the viability loss induced by serum withdrawal stress. CONCLUSIONS: These findings highlight that dynamized Gelsemium preparations may have neuroprotective effects against stress-induced cellular changes in the brain by regulating mitochondrial functions, essential for the survival, plasticity, and function of neurons in depression.

Asunto(s)

Supervivencia Celular , Mitocondrias , Neuronas , Fármacos Neuroprotectores , Humanos , Mitocondrias/efectos de los fármacos , Mitocondrias/metabolismo , Neuronas/efectos de los fármacos , Neuronas/metabolismo , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Fármacos Neuroprotectores/farmacología , Adenosina Trifosfato/metabolismo , Estrés Oxidativo/efectos de los fármacos , Óxido Nítrico/metabolismo , Extractos Vegetales/farmacología , Relación Dosis-Respuesta a Droga , Superóxidos/metabolismo

RESUMEN

Harnessing bacteria for superoxide production in bioremediation holds immense promise, yet its practical application is hindered by slow production rates and the relatively weak redox potential of superoxide. This study delves into a cost-effective approach to amplify superoxide production using an Arthrobacter strain, a prevalent soil bacterial genus. Our research reveals that introducing a carbon source along with specific iron-binding ligands, including deferoxamine (DFO), diethylenetriamine pentaacetate (DTPA), citrate, and oxalate, robustly augments microbial superoxide generation. Moreover, our findings suggest that these iron-binding ligands play a pivotal role in converting superoxide into hydroxyl radicals by modulating the electron transfer rate between Fe(III)/Fe(II) and superoxide. Remarkably, among the tested ligands, only DTPA emerges as a potent promoter of this conversion process when complexed with Fe(III). We identify an optimal Fe(III) to DTPA ratio of approximately 1:1 for enhancing hydroxyl radical production within the Arthrobacter culture. This research underscores the efficacy of simultaneously introducing carbon sources and DTPA in facilitating superoxide production and its subsequent conversion to hydroxyl radicals, significantly elevating bioremediation performance. Furthermore, our study reveals that DTPA augments superoxide production in cultures of diverse soils, with various soil microorganisms beyond Arthrobacter identified as contributors to superoxide generation. This emphasizes the universal applicability of DTPA across multiple bacterial genera. In conclusion, our study introduces a promising methodology for enhancing microbial superoxide production and its conversion into hydroxyl radicals. These findings hold substantial implications for the deployment of microbial reactive oxygen species in bioremediation, offering innovative solutions for addressing environmental contamination challenges.

Asunto(s)

Arthrobacter , Biodegradación Ambiental , Radical Hidroxilo , Hierro , Superóxidos , Radical Hidroxilo/metabolismo , Superóxidos/metabolismo , Arthrobacter/metabolismo , Hierro/metabolismo , Ligandos , Microbiología del Suelo , Contaminantes del Suelo/metabolismo , Deferoxamina/metabolismo

RESUMEN

BACKGROUND: Drug-induced liver injury (DILI) is the most important standard for the entrance of clinical drugs into the pharmaceutical market. The elevation of superoxide anion (O2•-) during drug metabolism can mediate apoptosis of hepatocytes and further generation of liver damage. Therefore, developing an effective imaging method for evaluating O2•- levels during DILI is of great importance. However, current reported O2•- fluorescent probes either use short excitation wavelengths or a single intensity detection system, limiting the accurate quantification of O2•- in deep tissue in vivo. RESULTS: We developed a NIR-excited ratiometric nanoprobe (CyD-UCNPs) by assembly of O2•--sensitive hemicyanine dyes (CyD) on the surface of Tm/Er-codoped upconversion nanoparticles (UCNPs) with the assistance of α-cyclodextrin, which exhibited a robust "turn-on" ratiometric sensing signal. In vitro experiments indicated that CyD-UCNPs respond well to O2•- with high selectivity. Furthermore, by taking advantage of the outstanding optical properties produced by the luminescent resonance energy transfer between the UCNPs and CyD upon the excitation of 980 nm, the ratiometric upconversion luminescence signal of CyD-UCNPs was successfully utilized to monitor the fluctuation of O2•- levels under phorbol-12-myristate-13-acetate (PMA)/cisplatin-induced oxidative stress in living cells, liver tissues, and zebrafish. More importantly, endogenous change in O2•- levels in the liver sites of mice during DILI and its prevention with L-carnitine was visualized using CyD-UCNPs. SIGNIFICANCE: This study provides a ratiometric NIR-excited imaging strategy for investigating the correlation between O2•- levels and DILI and its prevention, which is significant for early diagnosis of DILI and preclinical screening of anti-hepatotoxic drugs in vivo.

Asunto(s)

Carbocianinas , Enfermedad Hepática Inducida por Sustancias y Drogas , Colorantes Fluorescentes , Rayos Infrarrojos , Nanopartículas , Superóxidos , Enfermedad Hepática Inducida por Sustancias y Drogas/diagnóstico por imagen , Enfermedad Hepática Inducida por Sustancias y Drogas/metabolismo , Animales , Superóxidos/análisis , Superóxidos/metabolismo , Superóxidos/química , Ratones , Colorantes Fluorescentes/química , Carbocianinas/química , Nanopartículas/química , Humanos , Pez Cebra , Imagen Óptica , Transducción de Señal/efectos de los fármacos

RESUMEN

We describe the antioxidant capability of scavenging the superoxide radical of several tea and yerba mate samples using rotating ring-disk electrochemistry (RRDE). We directly measured superoxide concentrations and detected their decrease upon the addition of an antioxidant to the electrochemical cell. We studied two varieties of yerba mate, two varieties of black tea from Bangladesh, a sample of Pu-erh tea from China, and two components, caffeic acid and chlorogenic acid. All of these plant infusions and components showed strong antioxidant activities, virtually annihilating the available superoxide concentration. Using density functional theory (DFT) calculations, we describe a mechanism of superoxide scavenging via caffeic and chlorogenic acids. Superoxide can initially interact at two sites in these acids: the H4 catechol hydrogen (a) or the acidic proton of the acid (b). For (a), caffeic acid needs an additional π-π superoxide radical, which transfers electron density to the ring and forms a HO2- anion. A second caffeic acid proton and HO2- anion forms H2O2. Chlorogenic acid acts differently, as the initial approach of superoxide to the catechol moiety (a) is enough to form the HO2- anion. After an additional acidic proton of chlorogenic acid is given to HO2-, three well-separated compounds arise: (1) a carboxylate moiety, (2) H2O2, and a (3) chlorogenic acid semiquinone. The latter can capture a second superoxide in a π-π manner, which remains trapped due to the aromatic ring, as for caffeic acid. With enough of both acids and superoxide radicals, the final products are equivalent: H2O2 plus a complex of the type [X-acid-η-O2], X = caffeic, chlorogenic. Chlorogenic acid (b) is described by the following reaction: 2 O2•- + 2 chlorogenic acid → 2 chlorogenic carboxylate + O2 + H2O2, and so, it acts as a non-enzymatic superoxide dismutase (SOD) mimic, as shown via the product formation of O2 plus H2O2, which is limited due to chlorogenic acid consumption. Caffeic acid (b) differs from chlorogenic acid, as there is no acidic proton capture via superoxide. In this case, approaching a second superoxide to the H4 polyphenol moiety forms a HO2- anion and, later, an H2O2 molecule upon the transfer of a second caffeic acid proton.

Asunto(s)

Antioxidantes , Ácidos Cafeicos , Camellia sinensis , Ácido Clorogénico , Ilex paraguariensis , Superóxidos , Superóxidos/química , Superóxidos/metabolismo , Ácidos Cafeicos/química , Ácido Clorogénico/química , Ilex paraguariensis/química , Antioxidantes/química , Camellia sinensis/química , Teoría Funcional de la Densidad , Depuradores de Radicales Libres/química , Técnicas Electroquímicas , Extractos Vegetales/química

RESUMEN

Electrogenerated hydrophilic carbon (EHC) nanomaterials emerge as a highly attractive option for mimicking the activity of the superoxide dismutase enzyme (SOD) due to their exceptional water solubility and electron-transfer reversibility. Motivated by these properties, the EHC nanomaterials were utilized to assess the effect of ionic strength on the SOD-like activity. Superoxide anion radicals (O2•-) were generated using the hypoxanthine-xanthine oxidase system, with nitro blue tetrazolium chloride serving as the detecting system. A significant boost in the SOD-like activity was found via the addition of an electrolyte to the as-prepared nanomaterial solution. The effect of the electrolyte cation (Na+ and K+), as well as its counterion (Cl-, CH3COO-, and H2PO4-/HPO42-) were analyzed. Based on these studies, a new formulation for the preparation of the carbon-based nanomaterial was established. It was demonstrated that the SOD-like activity follows an enzyme-type catalytic activity rather than the stoichiometric scavenging of the superoxide anion radical. It was concluded that 12.71 µg/mL of the EHC nanomaterial exhibits catalytic activity comparable to 15.46 µg/mL of the native Cu/Zn-SOD enzyme. This study provides a starting point for the development of a new nanotool to fight the oxidative stress associated with pathophysiological conditions where SOD activity is depleted.

Asunto(s)

Carbono , Nanoestructuras , Superóxido Dismutasa , Superóxidos , Superóxido Dismutasa/metabolismo , Superóxido Dismutasa/química , Nanoestructuras/química , Concentración Osmolar , Carbono/química , Superóxidos/química , Xantina Oxidasa/química , Xantina Oxidasa/metabolismo

RESUMEN

Thermal burns are the most common type of burn injuries. Medical treatment for burns is crucial, especially for third-degree burns and when a significant surface area of the body is affected. One of the most pressing issues in modern medicine is the search for new effective means to accelerate the healing of burn wounds. Oxygen radicals play a significant role in maintaining homeostasis, forming the body's resistance to infection, and ensuring the regeneration of organs and tissues. In this study, a superoxide (O2-)-producing enzyme (SPE) from raspberries was applied (topically to the skin, injected under the wound surface, with solution concentrations of 12.75% and 5%) after a third-degree thermal burn to determine its reparative effects on the skin. To assess the condition of the animals that had suffered burn injuries and the healing process, blood parameters were analyzed, and cytogenetic indices of bone marrow from the femur of the animals were studied: mitotic index, number of polyploid cells, and chromosomal aberrations. When analyzing hematological, cytogenetic, and histological parameters, significant differences were found between the «clean burn¼ groups and the groups in which SPE was used in different concentrations and methods of application. The use of SPE in both concentrations contributed to a reduction in the area of burn wounds compared to a «clean burn¼. The survival rate of animals for 30 days (before the end of the experiment) was 100% when using a 12.75% SPE solution and 50% when using a 5% SPE solution. The use of SPE led to significant differences in hematological parameters from the «clean burn¼ group throughout the entire duration of the experiment, showing a tendency to normalize the parameters. Under the influence of the 12.75% SPE solution, there was a tendency toward normalization of the mitotic index, along with a significant reduction in the percentage of polyploid cells and chromosomal aberrations, which may indicate its beneficial effects. This study found that a 12.75% SPE solution derived from raspberries was more effective and had healing properties on third-degree thermal burns, promoting rapid healing of the burn wound.

Asunto(s)

Quemaduras , Rubus , Superóxidos , Cicatrización de Heridas , Quemaduras/patología , Quemaduras/tratamiento farmacológico , Animales , Ratas , Rubus/química , Cicatrización de Heridas/efectos de los fármacos , Superóxidos/metabolismo , Masculino , Aberraciones Cromosómicas/efectos de los fármacos , Ratas Wistar , Piel/efectos de los fármacos , Piel/patología , Piel/lesiones , Índice Mitótico

RESUMEN

Human space activities have been continuously increasing. Astronauts experiencing spaceflight are faced with health problems caused by special space environments such as microgravity, and the investigation of cell injury is fundamental. The development of a platform capable of cell culture and injury detection is the prerequisite for the investigation. Constructing a platform suitable for special conditions in space life science research is the key issue. The ground-based investigation is an indispensable part of the research. Accordingly, a simulated microgravity (SMG)-oriented integrated chip platform capable of 3D cell culture and in situ visual detection of superoxide anion radical (O2•-) is developed. SMG can cause oxidative stress in human cells, and O2•- is one of the signaling molecules. Thus, a O2•--responsive aggregation-induced emission (AIE) probe is designed, which shows high selectivity and sensitivity to O2•-. Moreover, the probe exhibits abilities of long-term and wash-free staining to cells due to the AIE behavior, which is precious for space cell imaging. Meanwhile, a chip with a high-aspect-ratio chamber for adequate medium storage for the lack of the perfusion system during the SMG experiment and a cell culture chamber which can integrate the extracellular matrix (ECM) hydrogel for the bioinspired 3D cell culture is fabricated. In addition, a porous membrane is introduced between the chambers to prevent the hydrogel from separating during the SMG experiment. The afforded AIE probe-ECM hydrogel-integrated chip can achieve 3D culturing of U87-MG cells and in situ fluorescent detection of endogenous O2•- in the cells after long-term staining under SMG. The chip provides a powerful and potential platform for ground-based investigation in space life science and biomedical research.

Asunto(s)

Técnicas Biosensibles , Hidrogeles , Superóxidos , Humanos , Superóxidos/análisis , Técnicas Biosensibles/instrumentación , Técnicas Biosensibles/métodos , Hidrogeles/química , Matriz Extracelular/química , Técnicas de Cultivo de Célula/instrumentación , Simulación de Ingravidez , Diseño de Equipo , Colorantes Fluorescentes/química , Dispositivos Laboratorio en un Chip , Ingravidez , Estrés Oxidativo

RESUMEN

The bactericidal activity of several antibiotics partially relies on the production of reactive oxygen species (ROS), which is generally linked to enhanced respiration and requires the Fenton reaction. Bacterial persister cells, an important cause of recurring infections, are tolerant to these antibiotics because they are in a dormant state. Here, we use Bacillus subtilis cells in stationary phase, as a model system of dormant cells, to show that pharmacological induction of membrane depolarization enhances the antibiotics' bactericidal activity and also leads to ROS production. However, in contrast to previous studies, this results primarily in production of superoxide radicals and does not require the Fenton reaction. Genetic analyzes indicate that Rieske factor QcrA, the iron-sulfur subunit of respiratory complex III, seems to be a primary source of superoxide radicals. Interestingly, the membrane distribution of QcrA changes upon membrane depolarization, suggesting a dissociation of complex III. Thus, our data reveal an alternative mechanism by which antibiotics can cause lethal ROS levels, and may partially explain why membrane-targeting antibiotics are effective in eliminating persisters.

Asunto(s)

Antibacterianos , Bacillus subtilis , Membrana Celular , Especies Reactivas de Oxígeno , Bacillus subtilis/efectos de los fármacos , Bacillus subtilis/metabolismo , Bacillus subtilis/fisiología , Especies Reactivas de Oxígeno/metabolismo , Antibacterianos/farmacología , Membrana Celular/metabolismo , Membrana Celular/efectos de los fármacos , Superóxidos/metabolismo , Potenciales de la Membrana/efectos de los fármacos , Complejo III de Transporte de Electrones/metabolismo , Complejo III de Transporte de Electrones/genética , Proteínas Bacterianas/metabolismo , Proteínas Bacterianas/genética

RESUMEN

The ability of Mycobacterium tuberculosis (Mtb) to tolerate nitric oxide (•NO) and superoxide (O2•-) produced by phagocytes contributes to its success as a human pathogen. Recombination of •NO and O2•- generates peroxynitrite (ONOO-), a potent oxidant produced inside activated macrophages causing lethality in diverse organisms. While the response of Mtb toward •NO and O2•- is well established, how Mtb responds to ONOO- remains unclear. Filling this knowledge gap is important to understand the persistence mechanisms of Mtb during infection. We synthesized a series of compounds that generate both •NO and O2•-, which should combine to produce ONOO-. From this library, we identified CJ067 that permeates Mtb to reliably enhance intracellular ONOO- levels. CJ067-exposed Mtb strains, including multidrug-resistant (MDR) and extensively drug-resistant (XDR) clinical isolates, exhibited dose-dependent, long-lasting oxidative stress and growth inhibition. In contrast, Mycobacterium smegmatis (Msm), a fast-growing, non-pathogenic mycobacterial species, maintained redox balance and growth in response to intracellular ONOO-. RNA-sequencing with Mtb revealed that CJ067 induces antioxidant machinery, sulphur metabolism, metal homeostasis, and a 4Fe-4S cluster repair pathway (suf operon). CJ067 impaired the activity of the 4Fe-4S cluster-containing TCA cycle enzyme, aconitase, and diminished bioenergetics of Mtb. Work with Mtb strains defective in SUF and IscS involved in Fe-S cluster biogenesis pathways showed that both systems cooperatively protect Mtb from intracellular ONOO- in vitro and inducible nitric oxide synthase (iNOS)-dependent growth inhibition during macrophage infection. Thus, Mtb is uniquely sensitive to intracellular ONOO- and targeting Fe-S cluster homeostasis is expected to promote iNOS-dependent host immunity against tuberculosis (TB).

Asunto(s)

Metabolismo Energético , Homeostasis , Proteínas Hierro-Azufre , Mycobacterium tuberculosis , Oxidación-Reducción , Ácido Peroxinitroso , Mycobacterium tuberculosis/metabolismo , Mycobacterium tuberculosis/genética , Mycobacterium tuberculosis/efectos de los fármacos , Ácido Peroxinitroso/metabolismo , Proteínas Hierro-Azufre/metabolismo , Proteínas Hierro-Azufre/genética , Humanos , Óxido Nítrico/metabolismo , Estrés Oxidativo , Mycobacterium smegmatis/metabolismo , Mycobacterium smegmatis/genética , Mycobacterium smegmatis/efectos de los fármacos , Superóxidos/metabolismo , Macrófagos/metabolismo , Macrófagos/microbiología , Tuberculosis/microbiología , Tuberculosis/metabolismo

RESUMEN

The study included 40 patients of both genders who underwent skin transplantation after a hand injury. The study aims to evaluate the oxidative stress parameters in patients' blood and serum levels of galectin-3 in order to investigate gender differences pre- and post- skin transplantation. The results of the study suggest a significant increase in superoxide anion radical levels, catalase activity, and reduced glutathione levels in females before skin transplantation. The surgical treatment caused significant increase in superoxide anion radical and hydrogen peroxide levels as prooxidants in males, while superoxide dismutase and catalase activity were also increased 7 days after the procedure. In females, superoxide anion radical and TBARS levels increased after surgical procedure as well as the activity of catalase. Regarding galectin-3 levels, a significant interaction between gender and time was observed (gender×time; p=0.000). Correlation analysis of different oxidative stress markers with gal-3 revealed the existence of a significant negative correlation of superoxide anion radical, catalase, and reduced glutathione with gal-3, but only in female patients. It can be concluded that OS as well as galectin-3 play important roles at least in the first 7 days of the postoperative period.

Asunto(s)

Catalasa , Galectina 3 , Glutatión , Traumatismos de la Mano , Estrés Oxidativo , Trasplante de Piel , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Adulto Joven , Proteínas Sanguíneas , Catalasa/sangre , Catalasa/metabolismo , Galectina 3/sangre , Galectina 3/metabolismo , Galectinas , Glutatión/sangre , Glutatión/metabolismo , Traumatismos de la Mano/cirugía , Traumatismos de la Mano/sangre , Traumatismos de la Mano/metabolismo , Peróxido de Hidrógeno/sangre , Peróxido de Hidrógeno/metabolismo , Caracteres Sexuales , Factores Sexuales , Superóxido Dismutasa/sangre , Superóxido Dismutasa/metabolismo , Superóxidos/metabolismo , Superóxidos/sangre , Sustancias Reactivas al Ácido Tiobarbitúrico/metabolismo

RESUMEN

Glucocorticoids (GCs) are known to stimulate pancreatic beta (ß)-cell apoptosis via several mechanisms, including oxidative stress. Our previous study suggested an increase in dexamethasone-induced pancreatic ß-cell apoptosis via a reduction of glutathione S-transferase P1 (GSTP1), which is an antioxidant enzyme. Imatinib, which is a tyrosine kinase inhibitor, also exerts antioxidant effect. This study aims to test our hypothesis that imatinib would prevent pancreatic ß-cell apoptosis induced by dexamethasone via increased GSTP1 expression and reduced oxidative stress. Our results revealed that dexamethasone significantly increased apoptosis in INS-1 cells when compared to the control, and that imatinib significantly decreased INS-1 cell apoptosis induced by dexamethasone. Moreover, dexamethasone significantly increased superoxide production in INS-1 cells when compared to the control; however, imatinib, when combined with dexamethasone, significantly reduced superoxide production in INS-1 cells. Dexamethasone significantly decreased GSTP1, p-ERK1/2, and BCL2 protein expression, but significantly increased p-JNK, p-p38, and BAX protein expression in INS-1 cells-all compared to control. Importantly, imatinib significantly ameliorated the effect of dexamethasone on the expression of GSTP1, p-ERK1/2, p-JNK, p-p38 MAPK, BAX, and BCL2. Furthermore-6-(7-nitro-2,1,3-benzoxadiazol-4-ylthio) hexanol (NBDHEX), which is a GSTP1 inhibitor, neutralized the protective effect of imatinib against pancreatic ß-cell apoptosis induced by dexamethasone. In conclusion, imatinib decreases pancreatic ß-cell apoptosis induced by dexamethasone via increased GSTP1 expression and reduced oxidative stress.

Asunto(s)

Apoptosis , Dexametasona , Gutatión-S-Transferasa pi , Mesilato de Imatinib , Células Secretoras de Insulina , Estrés Oxidativo , Mesilato de Imatinib/farmacología , Dexametasona/farmacología , Estrés Oxidativo/efectos de los fármacos , Apoptosis/efectos de los fármacos , Células Secretoras de Insulina/efectos de los fármacos , Células Secretoras de Insulina/metabolismo , Gutatión-S-Transferasa pi/metabolismo , Animales , Ratas , Línea Celular , Superóxidos/metabolismo

RESUMEN

BACKGROUND: Despite the increasing popularity of various materials for ischemia-reperfusion (I/R) injury mitigation, research on botulinum toxin type A (BoNTA) remains limited. This study assesses BoNTA's efficacy in protecting flaps from I/R injury by inhibiting the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase system and reducing reactive oxygen species (ROS) production. METHODS: Seventy-six Sprague-Dawley rats were studied. We examined the effects of BoNTA on superoxide production in four rats using a lucigenin-enhanced chemiluminescence assay (LECL). Another group of 60 rats had their superficial inferior epigastric artery (SIEA) flaps treated with either BoNTA or saline and clamped for 0, 1, and 4 hours before reperfusion. Flap survival and histological outcomes were assessed five days post-operation. ROS production in SIEA flaps and femoral vessels was analyzed in 12 additional rats, post-I/R injury. RESULTS: The LECL results showed that the BoNTA group had significantly lower superoxide production compared to controls, with notable reductions at 4 hours. While no significant differences were noted at the 0 and 1-hour marks, the 4-hour mark showed significant protective effects in BoNTA-treated groups. The survival rate was 90% for BoNTA-treated rats versus 60% for controls ( P = 0.028). Significant reductions in ROS were also observed in the 4-hour I/R group. CONCLUSIONS: BoNTA effectively protects against I/R injury by inhibiting the NADPH oxidase system and reducing ROS levels. These results support further investigation into the specific mechanisms of NADPH oxidase inhibition by BoNTA and its potential clinical applications, given its safety profile. CLINICAL RELEVANCE STATEMENT: The findings from the present study are expected to provide a basis for clinical studies regarding this use of BoNTA.

Asunto(s)

Toxinas Botulínicas Tipo A , NADPH Oxidasas , Ratas Sprague-Dawley , Especies Reactivas de Oxígeno , Daño por Reperfusión , Animales , Daño por Reperfusión/prevención & control , Daño por Reperfusión/etiología , Toxinas Botulínicas Tipo A/farmacología , Toxinas Botulínicas Tipo A/administración & dosificación , NADPH Oxidasas/metabolismo , NADPH Oxidasas/antagonistas & inhibidores , Ratas , Masculino , Especies Reactivas de Oxígeno/metabolismo , Colgajos Quirúrgicos/irrigación sanguínea , Superóxidos/metabolismo , Modelos Animales de Enfermedad

RESUMEN

Drug-induced liver injury (DILI) poses a significant risk to human health. Increasing evidence indicates that the superoxide anion (O2•-), as the precursor of the other reactive oxygen species, is key in the pathological processes associated with DILI. Nonetheless, understanding of the mechanisms of DILI is difficult due to the lack of an imaging tool for monitoring the fluctuation of O2•- levels during the progression of DILI. Herein, we developed an upconversion nanoprobe (Rbh-UCNs) for in vivo ratiometric tracking of endogenous O2•- in DILI. In this design, the addition of O2•- triggers the luminescent resonance energy transfer between Rbh and UCNs, which significantly enhances absorption centered at 534 nm and translates into a distinct decrease of the UCL emission at 543 nm, while the UCL emission peak at 654 nm and 800 nm are not significantly affected, offering a ratiometric UCL signal for the quantitative detection of O2•-. In addition, Rbh-UCNs could effectively visualize endogenous O2•- in living cells, zebrafish, and liver tissues upon stimulation with PMA or cisplatin. More importantly, tissue imaging of the liver region of mice revealed that the fluctuation of O2•- levels is associated with DILI and the protective effect of L-carnitine against DILI. Altogether, this study provides an available method for a deeper comprehension of the mechanisms underlying DILI and accelerating the development process of hepatoprotective medicines.

Asunto(s)

Enfermedad Hepática Inducida por Sustancias y Drogas , Superóxidos , Pez Cebra , Enfermedad Hepática Inducida por Sustancias y Drogas/diagnóstico por imagen , Animales , Superóxidos/análisis , Superóxidos/metabolismo , Ratones , Humanos , Nanopartículas/química , Nanopartículas/toxicidad , Rayos Infrarrojos , Imagen Óptica , Hígado/diagnóstico por imagen , Hígado/metabolismo , Luminiscencia

RESUMEN

Human manganese superoxide dismutase (MnSOD) is a crucial oxidoreductase that maintains the vitality of mitochondria by converting superoxide (O2●-) to molecular oxygen (O2) and hydrogen peroxide (H2O2) with proton-coupled electron transfers (PCETs). Human MnSOD has evolved to be highly product inhibited to limit the formation of H2O2, a freely diffusible oxidant and signaling molecule. The product-inhibited complex is thought to be composed of a peroxide (O22-) or hydroperoxide (HO2-) species bound to Mn ion and formed from an unknown PCET mechanism. PCET mechanisms of proteins are typically not known due to difficulties in detecting the protonation states of specific residues that coincide with the electronic state of the redox center. To shed light on the mechanism, we combine neutron diffraction and X-ray absorption spectroscopy of the product-bound, trivalent, and divalent states of the enzyme to reveal the positions of all the atoms, including hydrogen, and the electronic configuration of the metal ion. The data identifies the product-inhibited complex, and a PCET mechanism of inhibition is constructed.

Asunto(s)

Superóxido Dismutasa , Humanos , Superóxido Dismutasa/metabolismo , Superóxido Dismutasa/química , Peróxido de Hidrógeno/metabolismo , Peróxido de Hidrógeno/química , Manganeso/metabolismo , Manganeso/química , Transporte de Electrón , Oxidación-Reducción , Espectroscopía de Absorción de Rayos X , Superóxidos/metabolismo , Superóxidos/química , Protones , Electrones , Modelos Moleculares , Oxígeno/metabolismo , Oxígeno/química

RESUMEN

Nanoplastics (NPs) affect fertility. We evaluated the effects of NPs treatment on luteal and endothelial cells. We examined crucial markers of growth and redox status. NPs treatment did not induce changes in ATP levels in luteal cells, while it increased (p< 0.05) their proliferation. In endothelial cells, no change in proliferation was detected, while an increase (p<0.05) in ATP levels was observed. The increase of reactive oxygen species, superoxide anion (p<0.05) and nitric oxide (p<0.001) was detected in both cell types, which also showed changes in superoxide dismutase enzyme activity as well as an increase of non-enzymatic antioxidant power (p<0.05). A decrease (p<0.05) in progesterone production as well as an increase of vascular endothelial growth factor A levels were detected (p<0.05). In addition, a dose-dependent accumulation of NPs in endothelial cells was shown, that likely occurred through adhesion and internalization. Results underline potential risk of NPs for corpus luteum functionality.

Asunto(s)

Proliferación Celular , Cuerpo Lúteo , Células Endoteliales , Nanopartículas , Óxido Nítrico , Progesterona , Especies Reactivas de Oxígeno , Factor A de Crecimiento Endotelial Vascular , Animales , Femenino , Cuerpo Lúteo/efectos de los fármacos , Porcinos , Progesterona/metabolismo , Células Endoteliales/efectos de los fármacos , Células Endoteliales/metabolismo , Óxido Nítrico/metabolismo , Factor A de Crecimiento Endotelial Vascular/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Proliferación Celular/efectos de los fármacos , Nanopartículas/toxicidad , Superóxido Dismutasa/metabolismo , Adenosina Trifosfato/metabolismo , Microplásticos/toxicidad , Células Cultivadas , Superóxidos/metabolismo

RESUMEN

PURPOSE: While reactive oxygen species (ROS) have been identified as key redox signaling agents contributing to aging process, which and how specific oxidants trigger healthy longevity remain unclear. This paper aimed to explore the precise role and signaling mechanism of superoxide (O2•-) in health and longevity. METHODS: A tool for precise regulation of O2•- levels in vivo was developed based on the inhibition of superoxide dismutase 1 (SOD1) by tetrathiomolybdate (TM) in Caenorhabditis elegans (C. elegans). Then, we examined the effects of TM on lifespan, reproduction, lipofuscin accumulation, mobility, and stress resistance. Finally, the signaling mechanism for longevity induced by TM-O2•- was screened by transcriptome analysis and tested in sod-1 and argk-1 RNAi strains, sod-2, sod-3, and daf-16 mutants. RESULTS: TM promoted longevity in C. elegans with a concomitant extension of healthy lifespan as indicated by increasing fertility and mobility and reducing lipofuscin accumulation, as well as enhanced resistance to different abiotic stresses. Mechanically, TM could precisely regulate O2•- levels in nematodes via modulating SOD1 activity. An O2•- scavenger Mn(III)TBAP abolished TM-induced lifespan extension, while an O2•- generator paraquat at low concentration mimicked the life prolongation effects. The longevity in TM-treated worms was abolished by sod-1 RNAi but was not affected in sod-2 or sod-3 mutants. Further transcriptome analysis revealed arginine kinase ARGK-1 and its downstream insulin/insulin-like growth factor 1 signaling (IIS) as potential effectors for TM-O2•‾-induced longevity, and argk-1 RNAi or daf-16 mutant nullified the longevity. CONCLUSIONS: These findings indicate that it is feasible to precisely control specific oxidant in vivo and O2•- orchestrates TM-induced health and longevity in C. elegans via ARGK-1-IIS axis.

Asunto(s)

Proteínas de Caenorhabditis elegans , Caenorhabditis elegans , Longevidad , Molibdeno , Transducción de Señal , Superóxido Dismutasa , Superóxidos , Animales , Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/genética , Caenorhabditis elegans/efectos de los fármacos , Longevidad/efectos de los fármacos , Longevidad/genética , Proteínas de Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/genética , Superóxido Dismutasa/metabolismo , Superóxido Dismutasa/genética , Molibdeno/farmacología , Molibdeno/metabolismo , Superóxidos/metabolismo , Superóxido Dismutasa-1/metabolismo , Superóxido Dismutasa-1/genética , Estrés Oxidativo/efectos de los fármacos , Factores de Transcripción Forkhead/metabolismo , Factores de Transcripción Forkhead/genética , Especies Reactivas de Oxígeno/metabolismo , Interferencia de ARN

RESUMEN

Chemerin is an adipokine that contributes to metabolism regulation. Nucleus tractus solitarius (NTS) is the first relay station in the brain for accepting various visceral afferent activities for regulating cardiovascular activity. However, the roles of chemerin in the NTS in regulating sympathetic activity and blood pressure are almost unknown. This study aimed to determine the role and potential mechanism of chemerin in the NTS in modulating sympathetic outflow and blood pressure. Bilateral NTS microinjections were performed in anaesthetized adult male Sprague-Dawley rats. Renal sympathetic nerve activity (RSNA), mean arterial pressure (MAP) and heart rate (HR) were continuously recorded. Chemerin and its receptor chemokine-like receptor 1 (CMKLR1) were highly expressed in caudal NTS (cNTS). Microinjection of chemerin-9 to the cNTS increased RSNA, MAP and HR, which were prevented by CMKLR1 antagonist α-NETA, superoxide scavenger tempol or N-acetyl cysteine, nicotinamide adenine dinucleotide phosphate (NADPH) oxidase inhibitors diphenyleneiodonium or apocynin. Chemerin-9 increased superoxide production and NADPH oxidase activity in the cNTS. The increased superoxide production induced by chemerin-9 was inhibited by α-NETA. The effects of cNTS microinjection of chemerin-9 on the RSNA, MAP and HR were attenuated by the pretreatment with paraventricular nucleus (PVN) microinjection of NMDA receptor antagonist MK-801 rather than AMPA/kainate receptor antagonist CNQX. These results indicate that chemerin-9 in the NTS increases sympathetic outflow, blood pressure and HR via CMKLR1-mediated NADPH oxidase activation and subsequent superoxide production in anaesthetized normotensive rats. Glutamatergic inputs in the PVN are needed for the chemerin-9-induced responses.

Asunto(s)

Presión Sanguínea , Quimiocinas , Ratas Sprague-Dawley , Núcleo Solitario , Sistema Nervioso Simpático , Animales , Núcleo Solitario/efectos de los fármacos , Núcleo Solitario/fisiología , Núcleo Solitario/metabolismo , Masculino , Quimiocinas/metabolismo , Presión Sanguínea/efectos de los fármacos , Presión Sanguínea/fisiología , Sistema Nervioso Simpático/fisiología , Sistema Nervioso Simpático/efectos de los fármacos , Ratas , Receptores de Quimiocina/metabolismo , Frecuencia Cardíaca/efectos de los fármacos , Frecuencia Cardíaca/fisiología , Péptidos y Proteínas de Señalización Intercelular/farmacología , Péptidos y Proteínas de Señalización Intercelular/administración & dosificación , NADPH Oxidasas/metabolismo , Superóxidos/metabolismo

RESUMEN

Flow-injection spin-trapping electron paramagnetic resonance (FI-EPR) methods that involve the use of 5,5-dimethyl-pyrroline-N-oxide (DMPO) as a spin-trapping reagent have been developed for the kinetic study of the O2•- radical scavenging reactions occurring in the presence of various plant-derived and synthetic phenolic antioxidants (Aox), such as flavonoid, pyrogallol, catechol, hydroquinone, resorcinol, and phenol derivatives in aqueous media (pH 7.4 at 25 °C). The systematically estimated second-order rate constants (ks) of these phenolic compounds span a wide range (from 4.5 × 10 to 1.0 × 106 M-1 s-1). The semilogarithm plots presenting the relationship between ks values and oxidation peak potential (Ep) values of phenolic Aox are divided into three groups (A1, A2, and B). The ks-Ep plots of phenolic Aox bearing two or three OH moieties, such as pyrogallol, catechol, and hydroquinone derivatives, belonged to Groups A1 and A2. These molecules are potent O2•- radical scavengers with ks values above 3.8 × 104 (M-1 s-1). The ks-Ep plots of all phenol and resorcinol derivatives, and a few catechol and hydroquinone derivatives containing carboxyl groups adjacent to the OH groups, were categorized into the group poor scavengers (ks < 1.6 × 103 M-1 s-1). The ks values of each group correlated negatively with Ep values, supporting the hypothesis that the O2•- radical scavenging reaction proceeds via one-electron and two-proton processes. The processes were accompanied by the production of hydrogen peroxide at pH 7.4. Furthermore, the correlation between the plots of ks and the OH proton dissociation constant (pKa•) of the intermediate aroxyl radicals (ks-pKa• plots) revealed that the second proton transfer process could potentially be the rate-determining step of the O2•- radical scavenging reaction of phenolic compounds. The ks-Ep plots provide practical information to predict the O2•- radical scavenging activity of plant-derived phenolic compounds based on those molecular structures.

Asunto(s)

Depuradores de Radicales Libres , Oxidación-Reducción , Fenoles , Superóxidos , Espectroscopía de Resonancia por Spin del Electrón , Cinética , Fenoles/química , Depuradores de Radicales Libres/química , Superóxidos/química , Detección de Spin

RESUMEN

Clostridioides difficile causes a serious diarrheal disease and is a common healthcare-associated bacterial pathogen. Although it has a major impact on human health, the mechanistic details of C. difficile intestinal colonization remain undefined. C. difficile is highly sensitive to oxygen and requires anaerobic conditions for in vitro growth. However, the mammalian gut is not devoid of oxygen, and C. difficile tolerates moderate oxidative stress in vivo. The C. difficile genome encodes several antioxidant proteins, including a predicted superoxide reductase (SOR) that is upregulated upon exposure to antimicrobial peptides. The goal of this study was to establish SOR enzymatic activity and assess its role in protecting C. difficile against oxygen exposure. Insertional inactivation of sor rendered C. difficile more sensitive to superoxide, indicating that SOR contributes to antioxidant defense. Heterologous C. difficile sor expression in Escherichia coli conferred protection against superoxide-dependent growth inhibition, and the corresponding cell lysates showed superoxide scavenging activity. Finally, a C. difficile SOR mutant exhibited global proteome changes under oxygen stress when compared to the parent strain. Collectively, our data establish the enzymatic activity of C. difficile SOR, confirm its role in protection against oxidative stress, and demonstrate SOR's broader impacts on the C. difficile vegetative cell proteome.IMPORTANCEClostridioides difficile is an important pathogen strongly associated with healthcare settings and capable of causing severe diarrheal disease. While considered a strict anaerobe in vitro, C. difficile has been shown to tolerate low levels of oxygen in the mammalian host. Among other well-characterized antioxidant proteins, the C. difficile genome encodes a predicted superoxide reductase (SOR), an understudied component of antioxidant defense in pathogens. The significance of the research reported herein is the characterization of SOR's enzymatic activity, including confirmation of its role in protecting C. difficile against oxidative stress. This furthers our understanding of C. difficile pathogenesis and presents a potential new avenue for targeted therapies.

Asunto(s)

Clostridioides difficile , Estrés Oxidativo , Oxígeno , Superóxidos , Clostridioides difficile/genética , Clostridioides difficile/enzimología , Clostridioides difficile/metabolismo , Oxígeno/metabolismo , Superóxidos/metabolismo , Proteínas Bacterianas/metabolismo , Proteínas Bacterianas/genética , Oxidorreductasas/metabolismo , Oxidorreductasas/genética , Regulación Bacteriana de la Expresión Génica

RESUMEN

Methyl viologen (MV), also known as paraquat, is a widely used herbicide but has also been reported as highly toxic to different life forms. The mode of its operation is related to superoxide radical (O2.-) production and consequent oxidative damage. However, besides the damage to key macromolecules, reactive oxygen species (ROS; to which O2.- belongs) are also known as regulators of numerous ion transport systems located at cellular membranes. In this study, we used MV as a tool to probe the role of O2.- in regulating membrane-transport activity and systemic acquired tolerance in halophytic Chenopodium quinoa and glycophytic spinach plants. Both plant species showed growth reduction in terms of reduced shoot length, lower shoot fresh and dry weight, photosynthesis rate, and chlorophyll contents; however, quinoa showed less reduction in growth compared with spinach. This whole plant response was further examined by measuring the ion concentration, gene expression of ion transporters, activation of antioxidants, and osmolyte accumulation. We observed that at the mechanistic level, the differences in growth in response to MV were conferred by at least four complementary physiological mechanisms: (1) higher K+ loss from spinach leaves resulted from higher expression of MV-induced plasma membrane-based depolarization-activated K+ efflux GORK channel, (2) higher activation of high-affinity K+ uptake transporter HAK5 in quinoa, (3) higher antioxidant production and osmolyte accumulation in quinoa as compared with spinach, and (4) maintaining a higher rate of photosynthesis due to higher chlorophyll contents, and efficiency of photosystem II and reduced ROS and MDA contents. Obtained results also showed that MV induced O2.- significantly reduced N contents in both species but with more pronounced effects in glycophytic spinach. Taken together this study has shown the role of O2.- in regulating membrane ion transport and N metabolism in the leaves of halophyte vs. glycophyte in the context of oxidative stress tolerance.

Asunto(s)

Chenopodium quinoa , Homeostasis , Oxidación-Reducción , Fotosíntesis , Potasio , Spinacia oleracea , Superóxidos , Chenopodium quinoa/metabolismo , Spinacia oleracea/metabolismo , Spinacia oleracea/efectos de los fármacos , Superóxidos/metabolismo , Potasio/metabolismo , Clorofila/metabolismo , Paraquat/farmacología , Hojas de la Planta/metabolismo , Antioxidantes/metabolismo , Especies Reactivas de Oxígeno/metabolismo