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1.
Braz. j. biol ; 84: e249617, 2024. graf
Article in English | MEDLINE, LILACS, VETINDEX | ID: biblio-1345540

ABSTRACT

Abstract Hibernation is a natural condition of animals that lives in the temperate zone, although some tropical lizards also experience hibernation annually, such as the lizard native from South America, Salvator merianae, or "tegu" lizard. Even though physiological and metabolic characteristic associated with hibernation have been extensively studied, possible alterations in the red blood cells (RBC) integrity during this period remains unclear. Dehydration and fasting are natural consequences of hibernating for several months and it could be related to some cellular modifications. In this study, we investigated if the osmotic tolerance of RBCs of tegu lizard under hibernation is different from the cells obtained from animals while normal activity. Additionally, we indirectly investigated if the RBCs membrane of hibernating tegus could be associated with oxidation by quantifying oxidized biomolecules and the activity of antioxidant enzymes. Our findings suggest that RBCs are more fragile during the hibernation period, although we did not find evidence of an oxidative stress scenario associated with the accentuated fragility. Even though we did not exclude the possibility of oxidative damage during hibernation, we suggested that an increased RBCs volume as a consequence of hypoosmotic blood during hibernation could also affect RBCs integrity as noted.


Resumo A hibernação é uma condição natural dos animais que vivem na zona temperada, embora alguns lagartos tropicais também experenciem hibernação anualmente, como é o caso do lagarto nativo da América do Sul, Salvator merianae ou "teiú". Embora as características fisiológicas e metabólicas associadas à hibernação tenham sido amplamente estudadas, possíveis alterações na integridade das hemácias durante esse período ainda permanecem obscuras. A desidratação e o jejum são consequências naturais da hibernação por vários meses e podem estar relacionadas a algumas modificações celulares. Neste estudo, investigamos se a tolerância osmótica de hemácias do lagarto teiú sob hibernação são diferentes das células obtidas de animais em atividade normal. Além disso, investigamos indiretamente por meio da quantificação de biomoléculas oxidadas e da atividade de enzimas antioxidantes se a membrana das hemácias dos teiús em hibernação poderia estar associada à oxidação. Nossos resultados sugerem que as hemácias possuem maior fragilidade durante o período de hibernação, embora não tenhamos encontrado evidências de um cenário de estresse oxidativo associado à essa fragilidade acentuada. Embora não tenhamos excluído a possibilidade de dano oxidativo durante a hibernação, sugerimos que um aumento no volume das hemácias como consequência de sangue hipoosmótico durante a hibernação também poderia afetar a integridade de hemácias, tal como foi observado.


Subject(s)
Animals , Hibernation , Lizards , Oxidation-Reduction , Oxidative Stress , Erythrocytes
2.
Hematol., Transfus. Cell Ther. (Impr.) ; 43(4): 430-436, Oct.-Dec. 2021. graf, ilus
Article in English | LILACS | ID: biblio-1350823

ABSTRACT

ABSTRACT Background: In Philadelphia chromosome-negative myeloproliferative neoplasm (MPN) models, reactive oxygen species (ROS) are elevated and have been implicated in genomic instability, JAK2/STAT signaling amplification, and disease progression. Although the potential effects of ROS on the MPN phenotype, the effects of ruxolitinib treatment on ROS regulation have been poorly explored. Herein, we have reported the impact of ruxolitinib on redox signaling transcriptional network, and the effects of diphenyleneiodonium (DPI), a pan NOX inhibitor, in JAK2V617F-driven cellular models. Method: Redox signaling-related genes were investigated in SET2 cells upon ruxolitinib treatment by RNA-seq (GEO accession GSE69827). SET2 and HEL cells, which represent JAK2V617F-positive MPN cellular models with distinct sensitivity to apoptosis induced by ruxolitinib, were used. Cell viability was evaluated by MTT, apoptosis by annexin V/PI and flow cytometry, and cell signaling by quantitative PCR and Western blot. Main results: Ruxolitinib impacted on a network composed of redox signaling-related genes, and DUOX1 and DUOX2 were identified as potential modulators of ruxolitinib response. In SET2 and HEL cells, DPI reduced cell viability and, at low doses, it significantly potentiated ruxolitinib-induced apoptosis. In the molecular scenario, DPI inhibited STAT3, STAT5 and S6 ribosomal protein phosphorylation and induced PARP1 cleavage in JAK2V617F-positive cells. DPI combined with ruxolitinib increased PARP1 cleavage in SET2 cells and potentiated ruxolitinib-reduced STAT3, STAT5 and S6 ribosomal protein in HEL cells. Conclusion: Our study reveals a potential adaptation mechanism for resistance against ruxolitinib by transcriptionally reprogramming redox signaling in JAK2V617F cells and exposes redox vulnerabilities with therapeutic value in MPN cellular models.


Subject(s)
Janus Kinase 2 , Myelodysplastic-Myeloproliferative Diseases/drug therapy , Oxidation-Reduction , NADPH Oxidases , Dual Oxidases , Myeloproliferative Disorders
3.
Rev. cuba. oftalmol ; 34(2): e1018, 2021. tab, graf
Article in Spanish | LILACS, CUMED | ID: biblio-1341461

ABSTRACT

La catarata comprende la opacidad del cristalino, la cual puede afectar la corteza y el núcleo subcapsular anterior y posterior de manera progresiva, secundario a la acumulación de proteínas dañadas a este nivel, con pérdida del equilibrio entre la producción y la eliminación de las especies reactivas libres de oxígeno. La importancia de retrasar o identificar marcadores específicos, además de promover un nuevo blanco terapéutico, también es motivo de análisis y de estudio en diferentes líneas de investigación. Se realizó una revisión de la literatura del 01 de enero al 20 de julio del año 2020. Se utilizaron metabuscadores en inglés y español de PUBMED, INFOMED, CLINICALKEY, LILACS, EBSCO, SCIELO, PRISMA y UPTODATE, con el objetivo de identificar la nueva evidencia científica relacionada con el estrés oxidativo y su participación en la formación de la catarata. La barrera del cristalino funciona como un medio de intercambio entre diferentes moléculas, lo que impide el paso de antioxidantes al núcleo y provoca su opacificación. Las mitocondrias a nivel de la corteza del cristalino permiten la remoción de oxígeno. Posteriormente la fosforilación oxidativa forma radicales libres de superóxido que, de manera natural, con el paso del tiempo se acumulan a este nivel. Con la edad, la homeostasis adaptativa pierde la capacidad de responder ante los cambios de estrés oxidativo, por lo que el uso de antioxidantes -de manera profiláctica e intencionada- puede cambiar el destino último para esta patología. La falta de equilibrio en los procesos de óxido-reducción es responsable de la formación de la catarata(AU)


Cataract comprises opacification of the crystalline lens, which may progressively affect the cortex and the anterior subcapsular nucleus, secondary to accumulation of damaged proteins on this level, with loss of balance between production and elimination of free reactive oxygen species. The importance of delaying or identifying specific markers, as well as promoting a new therapeutic target, is the object of study and analysis of a variety of research lines. A review was conducted of the literature published from 1 January to 20 July 2020. Use was made of PubMed, Infomed, Clinical Key, Lilacs, EBSCO, SciELO, Prisma and UpToDate metasearch engines in English and Spanish to identify new scientific evidence about oxidative stress and its involvement in cataract formation. The crystalline lens barrier serves as a medium for exchange between various molecules, preventing entrance of antioxidants into the nucleus, which results in opacification. Mitochondria on the crystalline lens cortex allow oxygen removal. Oxidative phosphorylation then forms free superoxide radicals which naturally accumulate on this level with the passing of time. With aging, adaptive homeostasis loses its ability to respond to oxidative stress changes, but the prophylactic, targeted use of antioxidants may change the ultimate fate of this condition. Lack of balance in oxidation-reduction processes is the cause of cataract formation(AU)


Subject(s)
Humans , Oxidation-Reduction , Cataract/etiology , Reactive Oxygen Species , Homeostasis , Lens Cortex, Crystalline , Review Literature as Topic
4.
Int. braz. j. urol ; 47(1): 112-119, Jan.-Feb. 2021. tab, graf
Article in English | LILACS | ID: biblio-1134303

ABSTRACT

ABSTRACT Purpose: Understanding the effects of high oxidation reduction potential (ORP) levels on sperm parameters will help to identify patients with unexplained and male factor infertility who may have seminal oxidative stress and determine if ORP testing is needed. This study aimed to evaluate the association between seminal ORP and conventional sperm parameters. Materials and Methods: A total of 58 patients who provided a semen sample for simultaneous evaluation of sperm parameters and ORP between January and September 2019 were enrolled in this retrospective study. To identify normal and high ORP levels, a static ORP (sORP) cut-off value of 1.36mV/106sperm/mL was used. Sperm parameters were compared between infertile men with normal sORP (control group, n=23) and high sORP values (study group, n=35). Results: Men with sORP values >1.36mV/106sperm/mL had significantly lower total sperm count (TSC) (p <0.001), sperm concentration (p <0.001) and total motile sperm count (TMSC) (p <0.001). In addition, progressive motility (p=0.04) and fast forward progressive motility (p <0.001) were significantly lower in the study group. A negative correlation was found between sORP and TSC (r=-0.820, p <0.001), sperm concentration (r=-0.822, p <0.001), TMSC (r=-0.808, p <0.001) and progressive motility (r=-0.378, p=0.004). Non-progressive motility positively correlated with sORP (r=0.344, p=0.010). Conclusions: This study has shown that TSC, sperm concentration, progressive motility and TMSC are associated with seminal oxidative stress, indicated by a sORP cut-off of 1.36mV/106sperm/mL. Presence of oligozoospermia, reduced progressive motilty or low TMSC in sperm analysis should raise the suspicion of oxidative stress and warrants seminal ROS testing.


Subject(s)
Humans , Male , Sperm Motility , Infertility, Male , Oxidation-Reduction , Semen , Sperm Count , Spermatozoa , Retrospective Studies
5.
J. Health Biol. Sci. (Online) ; 9(1): 1-6, 2021. tab, graf
Article in English | LILACS | ID: biblio-1352368

ABSTRACT

Objective: In this work, rats isolated hearts were infused EPA before the ischemia period and during reperfusion for available get well in parameter relatives to redox reactions. Methods: The effect of EPA was tested on isolated hearts induced to ischemia and reperfusion, treatment occurred at different times (ischemia or reperfusion). Antioxidant capacity against peroxyl radicals, glutathione cysteine ligase activity, glutathione concentration, lactate dehydrogenase, and creatine kinase concentration was analyzed. Results: Hearts treated with eicosapentaenoic acid had the minor generation of species reactive oxygen and lipid damage after reperfusion. The GSH concentration was higher when the hearts were treated with eicosapentaenoic acid in the period of reperfusion. Conclusion: In conclusion, this study demonstrates that the dose of EPA (20µM) used before ischemia can act as a cardioprotective antioxidant molecule, prevented damage heart from ischemic and reperfusion injury


Objetivo: Neste trabalho, corações isolados de ratos foram infundidos com EPA antes do período de isquemia e durante a reperfusão para obtenção de melhora em parâmetros relativos às reações redox. Métodos: O efeito do EPA foi testado em corações isolados induzidos a isquemia e reperfusão, o tratamento ocorreu em diferentes momentos (isquemia ou reperfusão). A capacidade antioxidante contra os radicais peroxil, atividade da glutationa cisteína ligase, concentração de glutationa, lactato desidrogenase e concentração de creatina quinase foi analisada. Resultados: Corações tratados com ácido eicosapentaenóico tiveram a menor geração de espécies reativas de oxigênio e danos lipídicos após a reperfusão. A concentração de GSH foi maior quando os corações foram tratados com ácido eicosapentaenóico no período de reperfusão. Conclusão: Em conclusão, este estudo demonstra que a dose de EPA (20µM) utilizada antes da isquemia pode atuar como uma molécula antioxidante cardioprotetora, prevenindo danos ao coração por isquemia e lesão de reperfusão.


Subject(s)
Heart , Infarction , Ischemia , Oxidation-Reduction , Oxidoreductases , Reperfusion , Eicosapentaenoic Acid , Lactic Acid , Reference Parameters , Glutathione
6.
Article in Chinese | WPRIM | ID: wpr-878906

ABSTRACT

Nrf2 is the key transcription factor mainly for regulating oxidative homeostasis and cytoprotective responses against oxidative stress. Nrf2/Keap1 pathway is one of the most important cellular defense mechanisms against endogenous or exogenous oxidative stress. With its activation, a wide range of stress-related genes is transactivated to restore the cellular homeostasis. Recent studies revealed that the aberrant activation of Nrf2 is related to the malignant progression, chemotherapeutic drug resistance and poor prognosis. Nrf2 plays a crucial role in cancer malignancy and chemotherapeutic resistance by controlling the intracellular redox homeostasis through the activation of cytoprotective antioxidant genes. Nrf2 inhibitor containing many natural products has been deemed as a novel therapeutic strategy for human malignancies. This article reviews the progress of studies of the Nrf2/Keap1 pathway, and its biological impact in solid malignancies and molecular mechanisms for causing Nrf2 hyperactivation in cancer cells. In conclusion, we summarized the deve-lopment of Nrf2 inhibitors in recent years, in the expectation of providing reference for further drug development and clinical studies.


Subject(s)
Humans , Kelch-Like ECH-Associated Protein 1/metabolism , NF-E2-Related Factor 2/metabolism , Neoplasms/genetics , Oxidation-Reduction , Oxidative Stress
7.
Chinese Journal of Biotechnology ; (12): 816-830, 2021.
Article in Chinese | WPRIM | ID: wpr-878598

ABSTRACT

Due to abundant availability of shale gas and biogas, methane has been considered as one of the most potential carbon sources for industrial biotechnology. Methanotrophs carrying the native methane monooxygenase are capable of using methane as a sole energy and carbon source, which provides a novel strategy for reducing greenhouse gas emission and substituting edible substrates used in bioconversion processes. With the rapid development of genetic engineering tools and biosynthesis techniques, various strategies for improving the efficiency of methane bioconversion have been achieved to produce a variety of commodity bio-based products. Herein, we summarize several important aspects related with methane utilization and metabolic engineering of methanotrophs, including the modification of methane oxidation pathways, the construction of efficient cell factories, and biosynthesis of chemicals and fuels. Finally, the prospects and challenges of the future development of methane bioconversion are also discussed.


Subject(s)
Biofuels , Biotechnology , Metabolic Engineering , Methane , Oxidation-Reduction
8.
Acta Physiologica Sinica ; (6): 69-81, 2021.
Article in Chinese | WPRIM | ID: wpr-878237

ABSTRACT

Phospholipids are important components of biomembrane and lipoproteins. Phospholipids can be oxidized by free radicals/nonradicals and enzymes to form oxidized phospholipids (OxPLs), which can lead to further generation of oxidation products with different biological activities. Clinical evidence shows that OxPLs are constantly generated and transformed during the pathogenesis of atherosclerosis and accumulated at the lesion sites. OxPLs are highly heterogeneous mixtures that can influence the progress of atherosclerosis through a variety of related receptors or signaling pathways. This review summarizes the process of phospholipid oxidation, the related products, the interaction of OxPLs with endothelial cells, monocytes/macrophages, smooth muscle cells, platelets and lipoproteins involved in the pathological process of atherosclerosis, and the progress of the researches using OxPLs as a target to inhibit atherosclerosis in recent years.


Subject(s)
Atherosclerosis , Endothelial Cells , Humans , Myocytes, Smooth Muscle , Oxidation-Reduction , Phospholipids
9.
Chinese Journal of Biotechnology ; (12): 4147-4157, 2021.
Article in Chinese | WPRIM | ID: wpr-921495

ABSTRACT

Methanogens are unique microorganisms for methane production and the main contributor of the biogenic methane in atmosphere. Methyl-coenzyme M reductase (Mcr) catalyzes the last step of methane production in methanogenesis and the first step of methane activation in anaerobic oxidation of methane. The genes encoding this enzyme are highly conserved and are widely used as a marker in the identification and phylogenetic study of archaea. There has been a longstanding interest in its unique cofactor F430 and the underpinning mechanisms of enzymatic cleavage of alkane C-H bond. The recent breakthroughs of high-resolution protein and catalytic-transition-state structures further advanced the structure-function study of Mcr. In particular, the recent discovery of methyl-coenzyme M reductase-like (Mcr-like) enzymes that activates the anaerobic degradation of non-methane alkanes has attracted much interest in the molecular mechanisms of C-H activation without oxygen. This review summarized the advances on function-structure-mechanism study of Mcr/Mcr-like enzymes. Additionally, future directions in anaerobic oxidation of alkanes and greenhouse-gas control using Mcr/Mcr-like enzymes were proposed.


Subject(s)
Archaea/metabolism , Methane , Oxidation-Reduction , Oxidoreductases/metabolism , Phylogeny
10.
Mem. Inst. Oswaldo Cruz ; 115: e190405, 2020. graf
Article in English | LILACS | ID: biblio-1091247

ABSTRACT

BACKGROUND High-risk human papillomaviruses (HR-HPVs) are the etiological agents of cervical cancer. Among them, types 16 and 18 are the most prevalent worldwide. The HPV genome encodes three oncoproteins (E5, E6, and E7) that possess a high transformation potential in culture cells when transduced simultaneously. In the present study, we analysed how these oncoproteins cooperate to boost key cancer cell features such as uncontrolled cell proliferation, invasion potential, and cellular redox state imbalance. Oxidative stress is known to contribute to the carcinogenic process, as reactive oxygen species (ROS) constitute a potentially harmful by-product of many cellular reactions, and an efficient clearance mechanism is therefore required. Cells infected with HR-HPVs can adapt to oxidative stress conditions by upregulating the formation of endogenous antioxidants such as catalase, glutathione (GSH), and peroxiredoxin (PRX). OBJECTIVES The primary aim of this work was to study how these oncoproteins cooperate to promote the development of certain cancer cell features such as uncontrolled cell proliferation, invasion potential, and oxidative stress that are known to aid in the carcinogenic process. METHODS To perform this study, we generated three different HaCaT cell lines using retroviral transduction that stably expressed combinations of HPV-18 oncogenes that included HaCaT E5-18, HaCaT E6/E7-18, and HaCaT E5/E6/E7-18. FINDINGS Our results revealed a statistically significant increment in cell viability as measured by MTT assay, cell proliferation, and invasion assays in the cell line containing the three viral oncogenes. Additionally, we observed that cells expressing HPV-18 E5/E6/E7 exhibited a decrease in catalase activity and a significant augmentation of GSH and PRX1 levels relative to those of E5, E6/E7, and HaCaT cells. MAIN CONCLUSIONS This study demonstrates for the first time that HPV-18 E5, E6, and E7 oncoproteins can cooperate to enhance malignant transformation.


Subject(s)
Humans , Cell Transformation, Viral/genetics , Oncogene Proteins, Viral/metabolism , DNA-Binding Proteins/metabolism , Human papillomavirus 18/metabolism , Oxidation-Reduction , Gene Expression Regulation, Neoplastic , Cell Survival , Cell Line, Tumor/virology , Cell Proliferation
11.
Braz. arch. biol. technol ; 63: e20190072, 2020. graf
Article in English | LILACS | ID: biblio-1132180

ABSTRACT

Abstract In live organisms, there is a balance between the production of reactive oxygen species (ROS) and their neutralization. The increased level of these species leads to a condition called redox imbalance. The aim of this study was to evaluate the protective action of isobenzofuranones in primary cultures of hippocampal neurons subjected to redox imbalance. To accomplish this, MTT and LIVE/DEAD assays were initially performed. In the cultures pretreated with isobenzofuranones 1 and 2, there was a higher number of live cells when compared to that in the untreated ones. Regarding redox imbalance, there was a significant increase in the intracellular levels of ROS. The cultures pretreated with isobenzofuranones showed a reduction in ROS levels. Lipid peroxidation caused by oxidative damage was significantly reduced in the cultures pretreated with isobenzofuranones 1 and 2. Taken together, these data show the ability of isobenzofuranones 1 and 2 to significantly minimize cytotoxicity, cell death, intracellular levels of ROS and lipid peroxidation induced by redox imbalance. These results suggest that isobenzofuranones 1 and 2 represent a possible alternative therapy for the neurodegenerative disturbances that are triggered by ROS production increases.


Subject(s)
Animals , Male , Mice , Oxidation-Reduction/drug effects , Benzofurans/pharmacology , Reactive Oxygen Species , Neuroprotective Agents/pharmacology , Hydrogen Peroxide , Benzofurans/chemical synthesis , Cell Death , Primary Cell Culture , Hippocampus/cytology , Neurons/metabolism
12.
Biol. Res ; 53: 26, 2020. graf
Article in English | LILACS | ID: biblio-1124211

ABSTRACT

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


Subject(s)
Oxidation-Reduction/drug effects , Oxidative Stress/drug effects , Escherichia coli/drug effects , Metal Nanoparticles/toxicity , Gold/toxicity
13.
Article in Chinese | WPRIM | ID: wpr-828411

ABSTRACT

Quercetin is a kind of typical flavonoid, mainly found in various vegetables, fruits and Chinese herbs that are consumed daily, with the functions of anti-oxidation, anti-tumor, prevention and treatment of cardiovascular and cerebrovascular diseases. Quercetin is a natural compound with defined anti-tumor activity. Due to its low bioavailability and poor water solubility, quercetin has limitations in clinical application. The quercetin derivatives with good solubility, high bioavailability, metabolic stability, and low toxicity have been obtained through modification of quercetin structure. In recent years, a large number of quercetin ethers, esters, complexes, C-4 carbonyloxy substituted derivatives, A,B-ring modified compounds and other derivatives have been synthesized and tested for in vitro anticancer activity. The quercetin derivatives with anti-tumor activity synthesized in the last 5 years were reviewed in this paper.


Subject(s)
Biological Availability , Humans , Neoplasms , Oxidation-Reduction , Quercetin , Solubility
14.
Chinese Journal of Biotechnology ; (12): 2732-2740, 2020.
Article in Chinese | WPRIM | ID: wpr-878525

ABSTRACT

Dihydroorotate dehydrogenase is a flavin-dependent mitochondrial enzyme to catalyze the fourth step of the de novo synthesis of pyrimidine and to oxidize dihydroorotate to orotate. By selectively inhibiting dihydroorotate dehydrogenase, thereby inhibiting pyrimidine synthesis, the enzyme has been developed for the treatment of cancer, autoimmune diseases, bacterial or viral infections, parasitic diseases and so on. The development of inhibitory drugs requires a detailed understanding of the structural characteristics and catalytic cycle mechanism of dihydroorotate dehydrogenase. Therefore, this paper reviews these two aspects, and indicates perspectives of these inhibitors in clinical application.


Subject(s)
Catalysis , Mitochondria/metabolism , Oxidation-Reduction , Oxidoreductases Acting on CH-CH Group Donors/metabolism
15.
Chinese Journal of Biotechnology ; (12): 2674-2684, 2020.
Article in Chinese | WPRIM | ID: wpr-878520

ABSTRACT

By analyzing the shift of microbial communities under different iron/sulfur ratios, the response of metallurgical microorganisms to energy substrates was investigated based on molecular ecological networks. High-throughput sequencing of microbial samples from different domesticated batches was conducted to analyze the changes in community composition, alpha and beta diversity. Based on the molecular ecological network, the interactions between microorganisms under different iron/sulfur ratios were explored. Keystones were identified to analyze the community response to energy substrates. In the process of domestication based on different energy substrates, the dominant species in the in iron-rich and sulfur-less community were Acidithiobacillus ferrooxidans and A. ferriphilus. A. thiooxidans accounted for up to 90% in the sulfur-rich and iron-less community after 3 domesticating batches. The results of alpha and beta diversity analysis show that the domestication process of sulfur-rich and iron-less substrates reduced the diversity of microbial communities. Molecular ecological network analysis shows that the keystones were all rare species with low abundance. During the domestication by sulfur-rich and iron-less energy substrates, the bacterial species had a closer symbiotic relationship and the community was more stable. Through this domestication experiment, the impact of different energy substrates on microbial aggregation was clarified. Domesticating metallurgical microorganisms by using sulfur-rich and iron-less energy substrates made the microbial colonies to be more stable, which was conducive to the oxidation of iron and sulfur, promoting the dissolution of sulfide minerals. Our findings provide a reference for the directional domestication of metallurgical microorganisms.


Subject(s)
Acidithiobacillus/genetics , Iron , Minerals , Oxidation-Reduction , Sulfur
16.
Chinese Journal of Biotechnology ; (12): 2139-2150, 2020.
Article in Chinese | WPRIM | ID: wpr-878473

ABSTRACT

Thioredoxin reductase (TrxR) is one class of the most important antioxidant selenoproteins and is involved in regulating tumor genesis and progression. It has been reported that naphthoquinones can target and inhibit TrxR1 activity therefore produce reactive oxygen species (ROS) mediated by TrxR1, resulting into cellular redox imbalance and making the naphthoquinone compounds to become potential antitumor chemotherapy drugs. The purpose of this work is to explore the interaction between TrxR1 and menadione using biochemical and mass-spectrometric (MS) analyses, to further reveal the detailed mechanisms of TrxR1-mediated naphthoquinone reduction and inhibition of TrxR1 by naphthoquinone compounds. Using the site-directed mutagenesis and recombinantly expressed TrxR1 variants, we measured the steady-state kinetic parameters of menadione reduction mediated by TrxR1 and its variants, performed the inhibition analysis of menadione on TrxR1 activity, and eventually identified the interaction between menadione and TrxR1 through MS analysis. We found that Sec-to-Cys mutation at residue of 498 significantly enhanced the efficiency of TrxR1-mediated menadione reduction, though the Sec⁴⁹⁸ is capable to catalyze the menadione reduction, indicating that TrxR1-mediated menadione reduction is dominantly in a Se-independent manner. Mutation experiments showed that Cys⁴⁹⁸ is mainly responsible for menadione catalysis in comparison to Cys⁴⁹⁷, while the N-terminal Cys⁶⁴ is slightly stronger than Cys⁵⁹ regarding the menadione reduction. LC-MS results detected that TrxR1 was arylated with one molecule of menadione, suggesting that menadione irreversibly modified the hyper-reactive Sec residue at the C-terminus of selenoprotein TrxR1. This study revealed that TrxR1 catalyzes the reduction of menadione in a Se-independent manner meanwhile its activity is irreversibly inhibited by menadione. Hereby it will be useful for the research and development of naphthoquinone anticancer drugs targeting TrxR1.


Subject(s)
Catalysis , Drug Development , Oxidation-Reduction , Thioredoxin Reductase 1/metabolism , Vitamin K 3/metabolism
19.
Rev Assoc Med Bras (1992) ; 66(5): 600-606, 2020. tab, graf
Article in English | SES-SP, LILACS, SES-SP | ID: biblio-1136263

ABSTRACT

SUMMARY OBJECTIVE Lower physical fitness and poor motor performance were shown to be linked with higher levels of oxidative stress in children and adolescents with intellectual disabilities. Therefore, a moderate aerobic exercise for 12-weeks was performed to evaluate the effects of physical activity scores on motor functions, oxidative stress, and intelligence quotients (IQ) in school children with intellectual disability. METHODS A total of 65 school children aged (12-18 Yrs) were randomly included in this study. Intellectual disability (ID),motor skills,physical fitness(VO2max), total energy expenditure (TEE), MDA, 8-OHdG, TAC, NO, and total oxidative stress(OS)were assessed using pre-validated WISC-IQ score test, BOT-2 test, PA questionnaire, and immunoassay techniques respectively. RESULTS WISC-IQ and BOT-2 set scores of intellectual and motor skills performance showed a significant correlation with physical activity status and the regulation of oxidative stress-free radicals in school children with mild and moderate ID following 12 weeks of moderate exercise. The intellectual and motor skills performance of the participants correlated positively with the increase in TAC activity and physical fitness scores and negatively with MDA, 8-OHdG, NO, and Total-OS, respectively. Stepwise multiple regression analysis of the demographic, physical status and oxidative stress parameters explained around78.0 to 93.4 % of intellectual disability variation among schoolchildren. CONCLUSION Moderate aerobic training for12 weeks has a positive impact on improving intellectual ability of schoolchildren with ID via modulating redox status, improves physical fitness, and motor skills proficiency.


RESUMO OBJETIVO A baixa aptidão física e o baixo desempenho motor mostraram-se associados a níveis mais altos de estresse oxidativo em crianças e adolescentes com deficiência intelectual. Portanto, foi realizado um exercício aeróbico moderado por 12 semanas para avaliar os efeitos dos escores de atividade física nas funções motoras, estresse oxidativo e quocientes de inteligência (QI) em escolares com deficiência intelectual. MÉTODOS Um total de 65 crianças em idade escolar (12 a 18 anos) foi incluído aleatoriamente neste estudo. A incapacidade intelectual (DI), habilidades motoras, aptidão física (VO2máx), gasto energético total (ETE), MDA, 8-OHdG, TAC, NO e estresse oxidativo total (SG) foram avaliados pelo teste de pontuação Wisc-IQ pré-validado, teste BOT-2, questionário de PA e técnicas de imunoensaio, respectivamente. RESULTADOS Os escores do conjunto Wisc-IQ e BOT-2 do desempenho das habilidades intelectuais e motoras mostraram uma correlação significativa com o status da atividade física e a regulação dos radicais livres do estresse oxidativo em escolares com DI leve e moderada após 12 semanas de exercício moderado. O desempenho das habilidades intelectuais e motoras dos participantes correlacionou-se positivamente com o aumento dos escores de atividade TAC e aptidão física e negativamente com MDA, 8-OHdG, NO e Total-OS, respectivamente. Houve uma melhora significativa nas habilidades motoras, como áreas específicas de precisão motora fina, velocidade de corrida, agilidade, coordenação de membros superiores, força, coordenação bilateral e equilíbrio entre crianças em idade escolar após o programa de exercícios. A análise de regressão múltipla passo a passo dos parâmetros demográficos, do estado físico e do estresse oxidativo explicou em torno de 78,0 a 93,4% da variação da incapacidade intelectual entre os escolares. CONCLUSÃO O treinamento aeróbico moderado por 12 semanas tem um impacto positivo na melhoria da capacidade intelectual de escolares com DI por meio da modulação do status redox, melhora da aptidão física e proficiência em habilidades motoras.


Subject(s)
Humans , Child , Adolescent , Physical Fitness , Intellectual Disability , Oxidation-Reduction , Biomarkers/metabolism , Exercise , Oxidative Stress/physiology
20.
Braz. j. med. biol. res ; 53(6): e9237, 2020. tab, graf
Article in English | ColecionaSUS, LILACS, ColecionaSUS | ID: biblio-1132520

ABSTRACT

We investigated changes in oxidative biomarkers in brain regions such as brainstem, cerebellum, and cerebral cortex of 3-, 6-, 18-, 24-, and 30-month-old rats. We also assessed the effects of low-intensity exercise on these biomarkers in these regions of 6-, 18-, and 24-month-old rats that started exercise on a treadmill at 3, 15, and 21 months of age, respectively. Radiographic images of the femur were taken for all rats. A total of 25 rats (age: twelve 6-, ten 18-, ten 24-, and three 30-month-old rats) were used. Lipid hydroperoxide levels increased in cerebellum at 18 months. Total antioxidant activity exhibited lowest values in brainstem at 3 months. Superoxide dismutase activity did not exhibit significant changes during aging. Total thiol content exhibited lowest values in brain regions of 24- and 30-month-old rats. Exercise reduced total thiol content in brainstem at 6 months, but no change occurred in other regions and other ages. Femur increased its length and width and cortical thickness with advancing age. No change occurred in medullary width. Radiolucency increased and sclerosis was found in cortical and medullary bone with advancing age. Exercise reduced radiolucency and medullary sclerosis. Therefore, aging differentially changed oxidative biomarkers in different brain regions and radiographic measures of the femur. Low-intensity exercise only ameliorated some radiographic measurements of femur. Since the present study possessed limitations (small number of rats per group), a beneficial effect of regular low-intensity exercise on oxidative markers in brain cannot be ruled out.


Subject(s)
Animals , Male , Rats , Physical Conditioning, Animal/physiology , Brain/metabolism , Aging/physiology , Oxidative Stress/physiology , Femur/diagnostic imaging , Lipid Peroxides/analysis , Oxidation-Reduction , Aging/metabolism , Biomarkers/analysis , Lipid Peroxidation , Rats, Wistar , Femur/chemistry
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