RESUMO
Heme enzyme dysfunction causes a group of diseases called porphyrias. Particularly, a decrease in porphobilinogen deaminase, involved in the third step of heme biosynthesis, leads to acute intermittent porphyria (AIP). Considering our previous works demonstrating the multiplicity of brain metabolisms affected by porphyrinogenic agents, this study aimed to elucidate whether they cause any alteration on the mitochondrial respiratory chain. The activities of respiratory chain complexes (I to IV) were measured in encephalon mitochondria of CF1 male mice receiving volatile anesthetics: isoflurane (2 mL/kg) and sevoflurane (1.5 mL/kg), ethanol (30%), allylisopropylacetamide (AIA) (350 mg/kg), and barbital (167 mg/kg). Moreover, they were compared versus animals with pathological levels of 5-aminolevulinic acid (ALA, 40 mg/kg). Complex I-III activity was induced by isoflurane and decreased by AIA, ethanol, and ALA. Complex II-III activity was increased by sevoflurane and decreased by isoflurane and AIA. Complex II activity was increased by sevoflurane and barbital and decreased by AIA, ethanol, and ALA. Complex IV activity was increased by barbital and ALA and decreased by sevoflurane. The damage to the respiratory chain by ALA could be reflecting the pathophysiological condition of patients with AIP. Better understanding the broad effect of porphyrinogenic drugs and the mechanisms acting on the onset of AIP is vital in translational medicine.
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Rhodotorula mucilaginosa survives extreme conditions through several mechanisms, among them its carotenoid production and its branched mitochondrial respiratory chain (RC). Here, the branched RC composition was analyzed by biochemical and complexome profiling approaches. Expression of the different RC components varied depending on the growth phase and the carbon source present in the medium. R. mucilaginosa RC is constituted by all four orthodox respiratory complexes (CI to CIV) plus several alternative oxidoreductases, in particular two type-II NADH dehydrogenases (NDH2) and one alternative oxidase (AOX). Unlike others, in this yeast the activities of the orthodox and alternative respiratory complexes decreased in the stationary phase. We propose that the branched RC adaptability is an important factor for survival in extreme environmental conditions; thus, contributing to the exceptional resilience of R. mucilaginosa.
Assuntos
Extremófilos , Rhodotorula , Transporte de Elétrons , Rhodotorula/química , Rhodotorula/metabolismo , Membranas Mitocondriais/metabolismoRESUMO
Excessive fructose consumption is associated with the incidence of obesity and systemic inflammation, resulting in increased oxidative damage and failure to the function of brain structures. Thus, we hypothesized that fructose consumption will significantly increase inflammation, oxidative damage, and mitochondrial dysfunction in the mouse brain and, consequently, memory damage. The effects of different fructose concentrations on inflammatory and biochemical parameters in the mouse brain were evaluated. Male Swiss mice were randomized into four groups: control, with exclusive water intake, 5%, 10%, and 20% fructose group. The 10% and 20% fructose groups showed an increase in epididymal fat, in addition to higher food consumption. Inflammatory markers were increased in epididymal fat and in some brain structures. In the evaluation of oxidative damage, it was possible to observe significant increases in the hypothalamus, prefrontal cortex, and hippocampus. In the epididymal fat and in the prefrontal cortex, there was a decrease in the activity of the mitochondrial respiratory chain complexes and an increase in the striatum. Furthermore, short memory was impaired in the 10% and 20% groups but not long memory. In conclusion, excess fructose consumption can cause fat accumulation, inflammation, oxidative damage, and mitochondrial dysfunction, which can damage brain structures and consequently memory.
Assuntos
Frutose , Obesidade , Camundongos , Masculino , Animais , Frutose/efeitos adversos , Estresse Oxidativo , Inflamação , EncéfaloRESUMO
Bacillus subtilis is a Gram-positive bacterium with a respiratory chain embedded in the cytoplasmic membrane. The respiratory chain is bifurcated after menaquinol into a cytochrome b6c + caa3 branch and a branch with up to three quinol oxidases. The complexes that generate the proton gradient are b6c, associated with caa3 and aa3 oxidase. The b6c and caa3 complexes form a supercomplex, and it is proposed to form respiratory strings in the membrane. There is still information missing about the quinol branch and if the primary oxidase quinol aa3 is associated with the electron donor complexes. It is unclear whether succinate quinone reductase (SQR) can form associations with the quinol branch or the cytochrome branch. In this paper, we show the separation of an almost pure b6c complex associated with cytochromes c550 and c551. We obtained a b6c + caa3 supercomplex of 600 kDa and SQR, aa3, and NADH dehydrogenase by dodecyl maltoside solubilization and separation of the respiratory chain components by ionic exchange chromatography. We found that aa3 does not associate with other complexes. SQR was associated with the b6c complex in a mutant lacking aa3. This association could facilitate electron transfer from SQR to menaquinone-7. The lack of associations between the abundant quinol oxidase aa3 and other complexes is a feature we cannot explain yet.
Assuntos
Bacillus subtilis , Hidroquinonas , Transporte de Elétrons , Complexo II de Transporte de ElétronsRESUMO
AIM: To analyze the consumption of oxygen and to quantify the mitochondrial respiratory chain proteins (OXPHOS) in the gastrocnemius muscle of rats exposed to cigarette smoke and/or RT practitioners. MAIN METHODS: Wistar rats were divided into groups: Control (C), Smoker (S), Exercise (E) and Exercise Smoker (ES). Groups F and ES were exposed to the smoke of 4 cigarettes for 30 min, 2× a day, 5× a week, for 16 weeks. Groups E and ES performed four climbs with progressive load, 1× per day, 5× per week, for 16 weeks. The gastrocnemius muscle was collected for analysis of OXPHOS content and oxygen consumption. Groups S (vs. C) and ES (vs. C and E) showed lower body weight gain when observing the evolution curve. KEY FINDINGS: The S rats showed a reduction in the NDUFB8 proteins of complex 1, SDHB of complex 2, MTC01 of complex 4 and ATP5A of complex 5 (ATP Synthase) compared to Group C. Additionally, S rats also showed increased consumption of O2 in Basal, Leak, Complex I and I/II combined measures compared to the other groups, suggesting that the activity of the mitochondria of these animals increased in terms of coupling and uncoupling parameters. SIGNIFICANCE: Our data suggest that exposure to cigarette smoke for 16 weeks is capable of causing impairment of mitochondrial function with reduced expression of respiratory chain proteins in skeletal muscle. However, the RT was effective in preventing impairment of mitochondrial function in the skeletal muscle of rats exposed to secondary cigarette smoke.
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Fumar Cigarros , Treinamento Resistido , Humanos , Ratos , Animais , Ratos Wistar , Músculo Esquelético/metabolismo , Mitocôndrias , Nicotiana/efeitos adversos , Oxigênio/metabolismo , Trifosfato de Adenosina/metabolismoRESUMO
Chagas Disease, caused by the protozoan parasite Trypanosoma cruzi, affects nearly eight million people in the world. T. cruzi is a complex taxon represented by different strains with particular characteristics, and it has the ability to infect and interact with almost any nucleated cell. The T. cruzi-host cell interactions will trigger molecular signaling cascades in the host cell that will depend on the particular cell type and T. cruzi strain, and also on many different experimental variables. In this review we collect data from multiple transcriptomic and functional studies performed in different infection models, in order to highlight key differences between works that in our opinion should be addressed when comparing and discussing results. In particular, we focus on changes in the respiratory chain and oxidative phosphorylation of host cells in response to infection, which depends on the experimental model of T. cruzi infection. Finally, we also discuss host cell responses which reiterate independently of the strain, cell type and experimental conditions.
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Doença de Chagas , Trypanosoma cruzi , Comunicação Celular , Interações Hospedeiro-Parasita , Humanos , Transdução de Sinais , Transcriptoma , Trypanosoma cruzi/genéticaRESUMO
OBJECTIVES: Doxorubicin is a highly effective chemotherapeutic agent for treating several types of cancer; however, it can induce cardiotoxicity. We evaluated the influence of Pera and Moro orange juices on cardiac remodeling induced by acute administration of doxorubicin in rats. METHODS: We allocated 120 male Wistar rats into six groups: control (C), Pera orange juice (PO), Moro orange juice (MO), doxorubicin (D), doxorubicin + Pera orange juice (DPO), and doxorubicin + Moro orange juice (DMO). Groups PO and DPO received Pera orange juice, MO and DMO received Moro orange juice, and C and D received water with maltodextrin (100 g/L) for 4 wk. Subsequently, groups D, DPO, and DMO received 20 mg/kg doxorubicin and C, PO, and MO received saline. Echocardiogram and euthanasia were performed 48 h after doxorubicin injection. Juice and animal-serum flavonoid identification and quantification were evaluated by liquid chromatography/electrospray ionization multistage mass spectrometry. Oxidative stress and myocardial metabolism were evaluated by spectrophotometry. RESULTS: Systolic and diastolic left ventricular dysfunction increased oxidative stress and pathologic changes in myocardial energy metabolism of rats treated with doxorubicin. Intake of both orange juices improved left ventricular function, decreased oxidative stress, and attenuated the myocardial energy metabolism changes. Moro orange juice had a more pronounced effect than Pera orange juice in glutathione peroxidase activity, citrate synthase, and ß-hydroxyacyl-CoA dehydrogenase activity. CONCLUSIONS: Pera and Moro orange juices attenuated cardiac remodeling induced by doxorubicin, improved myocardial energy metabolism, and attenuated oxidative stress. However, Moro orange juice was more effective than Pera orange juice in modifying energy metabolism.
Assuntos
Citrus sinensis , Disfunção Ventricular Esquerda , Animais , Cardiotoxicidade/etiologia , Doxorrubicina/toxicidade , Metabolismo Energético , Masculino , Estresse Oxidativo , Ratos , Ratos Wistar , Disfunção Ventricular Esquerda/induzido quimicamenteRESUMO
The Amazonian aquatic ecosystem undergoes seasonal variations and daily changes that directly affect the availability of oxygen. During the day the levels of oxygen can reach supersaturation, and at night can drop to zero. In this way, aquatic organisms are exposed daily to physiological challenges regarding the availability of oxygen. The present study revealed significant differences in the physiology and performance of two cichlids: Geophagus proximus (black water cichlid - from Negro River) and Chaetobranchopsis orbicularis (white water cichlid - from Amazon River), exposed to hypoxia. The white water cichlid showed lower value (1.99 ± 0.79 pKa) of critical pressure of oxygen (Pcrit) and a longer time (68.00 ± 14.11 min) for total loss of balance (LOE); however, this species showed 50% mortality during exposure to hypoxia, while the black water cichlid did not show mortality. Both cichlids presented a decrease in O2 consumption rate (OCR) during hypoxia.. In this sense, it was observed that the black water cichlid presented several physiological strategies during hypoxia, such as, a significant increase in plasma cortisol levels, nucleoside triphosphate diphosphohydrolase activity (for adenosine diphosphate (ADP) as a substrate) in the gills, and the activity of adenosine deaminase (ADA) in gills and liver, in addition to a significant increase in the activity of complexes (II-III) in the transporter chain of electrons in both analyzed tissues and succinate dehydrogenase activity of gills' mitochondria. On the other hand, the only physiological change observed in the white water cichlid was a significant reduction in the activity of complexes II-III in gills and liver. Based on our findings, we can hypothesize that the white water cichlid specie has less tolerant to hypoxia when compared to the black water cichlid.
Assuntos
Ciclídeos/metabolismo , Hipóxia/metabolismo , Receptores Purinérgicos/metabolismo , Animais , Transporte de Elétrons , Água Doce , Hidrocortisona/sangue , Mitocôndrias Hepáticas/metabolismo , América do Sul , Especificidade da EspécieRESUMO
OBJECTIVES: To evaluate the clinical symptoms and biochemical findings and establish the genetic etiology in a cohort of pediatric patients with combined deficiencies of the mitochondrial respiratory chain complexes. STUDY DESIGN: Clinical and biochemical data were collected from 55 children. All patients were subjected to sequence analysis of the entire mitochondrial genome, except when the causative mutations had been identified based on the clinical picture. Whole exome sequencing/whole genome sequencing (WES/WGS) was performed in 32 patients. RESULTS: Onset of disease was generally early in life (median age, 6 weeks). The most common symptoms were muscle weakness, hypotonia, and developmental delay/intellectual disability. Nonneurologic symptoms were frequent. Disease causing mutations were found in 20 different nuclear genes, and 7 patients had mutations in mitochondrial DNA. Causative variants were found in 18 of the 32 patients subjected to WES/WGS. Interestingly, many patients had low levels of coenzyme Q10 in muscle, irrespective of genetic cause. CONCLUSIONS: Children with combined enzyme defects display a diversity of clinical symptoms with varying age of presentation. We established the genetic diagnosis in 35 of the 55 patients (64%). The high diagnostic yield was achieved by the introduction of massive parallel sequencing, which also revealed novel genes and enabled elucidation of new disease mechanisms.
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DNA Mitocondrial/genética , Doenças Metabólicas/genética , Doenças Mitocondriais/genética , Mutação , Ubiquinona/análogos & derivados , Adolescente , Adulto , Criança , Pré-Escolar , Análise Mutacional de DNA , Humanos , Lactente , Recém-Nascido , Doenças Metabólicas/enzimologia , Doenças Mitocondriais/enzimologia , Ubiquinona/sangue , Sequenciamento do Exoma , Adulto JovemRESUMO
An increase in crop competitiveness relative to weed interference has the potential to reduce crop yield losses. In this study, the effects of phytoalexin resveratrol were examined in Zea mays L. (corn) and in the weed species Ipomoea grandifolia (Dammer) O'Donell (morning glory). At a concentration range from 220 to 2200 µM resveratrol exerted a stimulus on Z. mays seedling growth that was more pronounced at low concentrations; in the weed species I. grandifolia, resveratrol exerted inhibitory action on seedling growth in all of the assayed concentration range. In I. grandifolia, resveratrol also inhibited the respiratory activity of the primary roots. In mitochondria isolated from Z. mays roots, resveratrol at concentrations above 440 µM inhibited the respiration coupled to ADP phosphorylation and the activities of NADH-oxidase, succinate-oxidase, and ATPsynthase. These effects were not reproduced in Z. mays grown in the presence of resveratrol as the respiratory activities of the roots were not affected. The finding that the resveratrol exerts beneficial effects on growth of Z. mays seedlings and inhibits the growth of I. grandifolia heightens the potential of resveratrol application for crop protection.
Assuntos
Metabolismo Energético/efeitos dos fármacos , Ipomoea/efeitos dos fármacos , Resveratrol/farmacologia , Zea mays/efeitos dos fármacos , Ipomoea/crescimento & desenvolvimento , Ipomoea/metabolismo , Complexos Multienzimáticos/metabolismo , NADH NADPH Oxirredutases/metabolismo , Oxirredutases/metabolismo , Proteínas de Plantas/metabolismo , Plantas Daninhas/efeitos dos fármacos , Plantas Daninhas/crescimento & desenvolvimento , Plantas Daninhas/metabolismo , Resveratrol/análise , Sesquiterpenos/análise , Sesquiterpenos/farmacologia , Zea mays/crescimento & desenvolvimento , Zea mays/metabolismo , FitoalexinasRESUMO
Phenylketonuria (PKU) is a metabolic disorder accumulating phenylalanine (Phe) and its metabolites in plasma and tissues of the patients. Regardless of the mechanisms, which Phe causes brain impairment, are poorly understood, energy deficit may have linked to the neurotoxicity in PKU. It is widely recognized that creatine is involved in maintaining of cerebral energy homeostasis. Because of this, in a previous work, we incorporated it into liposomes and this increased the concentration of creatine in the cerebral cortex. Here, we examined the effect of creatine nanoliposomes on parameters of oxidative stress, enzymes of phosphoryl transfer network, and activities of the mitochondrial respiratory chain complexes (RCC) in the cerebral cortex of young rats chemically induced hyperphenylalaninemia (HPA). HPA was induced with L-phenylalanine (5.2 µmol/g body weight; twice a day; s.c.), and phenylalanine hydroxylase inhibitor, α-methylphenylalanine (2.4 µmol/g body weight; once a day; i.p.), from the 7th to the 19th day of life. HPA reduced the activities of pyruvate kinase, creatine kinase, and complex II + III of RCC in the cerebral cortex. Creatine nanoliposomes prevented the inhibition of the activities of the complexes II + III, caused by HPA, and changes oxidative profile in the cerebral cortex. Considering the importance of the mitochondrial respiratory chain for brain energy production, our results suggesting that these nanoparticles protect against neurotoxicity caused by HPA, and can be viable candidates for treating patients HPA.
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Creatina/metabolismo , Lipossomos/metabolismo , Fenilcetonúrias/metabolismo , Animais , Encéfalo/metabolismo , Córtex Cerebral/metabolismo , Córtex Cerebral/patologia , Creatina/fisiologia , Creatina Quinase/metabolismo , Metabolismo Energético , Feminino , Hipocampo/metabolismo , Masculino , Nanopartículas/uso terapêutico , Oxirredução , Estresse Oxidativo/efeitos dos fármacos , Fenilalanina/metabolismo , Ratos , Ratos WistarRESUMO
Studies have indicated that epilepsy, an important neurological disease, can generate oxidative stress and mitochondrial dysfunction, among other damages to the brain. In this context, the use of antioxidant compounds could provide neuroprotection and help to reduce the damage caused by epileptic seizures and thereby the use of anticonvulsant drugs. Rosmarinic acid (RA) is an ester of caffeic acid and 3,4-dihydroxyphenylactic acid that prevents cell damage caused by free radicals, acting as an antioxidant. It also presents anti-inflammatory, antimutagenic, and antiapoptotic properties. In this work, we used two models of acute seizure, 4-aminopyridine (4-AP) and picrotoxin (PTX)-induced seizures in mice, to investigate the anticonvulsant, antioxidant, and neuroprotective profile of RA. Diazepam and valproic acid, antiepileptic drugs already used in the treatment of epilepsy, were used as positive controls. Although RA could not prevent seizures in the models used in this study, neither enhance the latency time to first seizure at the tested doses, it exhibited an antioxidant and neuroprotective effect. RA (8 and 16 mg/kg) decreased reactive oxygen species production, superoxide dismutase activity, and DNA damage, measured in hippocampus, after seizures induced by PTX and 4-AP. Catalase activity was decreased by RA only after seizures induced by 4-AP. The activity of the mitochondrial complex II was increased by RA in hippocampus samples after both seizure models. The results obtained in this study suggest that RA is able to reduce cell damage generated by the 4-AP and PTX seizures and therefore could represent a potential candidate in reducing pathophysiological processes involved in epilepsy.
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Anticonvulsivantes/farmacologia , Cinamatos/farmacologia , Depsídeos/farmacologia , Complexo II de Transporte de Elétrons/metabolismo , Mitocôndrias/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Convulsões/tratamento farmacológico , 4-Aminopiridina/farmacologia , Animais , Antioxidantes/metabolismo , Comportamento Animal/efeitos dos fármacos , Dano ao DNA , Modelos Animais de Doenças , Complexo II de Transporte de Elétrons/genética , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Camundongos , Mitocôndrias/metabolismo , Estresse Oxidativo/genética , Picrotoxina/farmacologia , Convulsões/metabolismo , Ácido RosmarínicoRESUMO
BACKGROUND: High fat or fructose induces non-alcoholic fatty liver disease (NAFLD) accompanied of mitochondrial dysfunction and oxidative stress. Controversy remains about whether fructose or fat is more deleterious for NAFLD development. To get more insights about this issue and to determine if the severity of liver disease induced by fructose or fat is related to degree of mitochondrial dysfunction, we compared the effects of diets containing high fat (HF), fructose (Fr) or high fat plus fructose (HF + Fr) on NAFLD development, mitochondrial function, ROS production and lipid peroxidation. METHODS: Wistar rats were assigned to four groups: Control, fed with standard rodent chow; High fat (HF), supplemented with lard and hydrogenated vegetable oil; Fructose (Fr), supplemented with 25% fructose in the drinking water; High fat plus fructose group (HF + Fr), fed with both HF and Fr diets. Rats were sacrificed after 6 weeks of diets consumption and the liver was excised for histopathological analysis by hematoxylin and eosin staining and for mitochondria isolation. Mitochondrial function was evaluated by measuring both mitochondrial respiration and complex I activity. Lipid peroxidation and ROS production were evaluated in mitochondria by the thiobarbituric acid method and with the fluorescent ROS probe 2,4-H2DCFDA, respectively. RESULTS: Fr group underwent the lower degree of both liver damage and mitochondrial dysfunction that manifested like less than 20% of hepatocytes with microvesicular steatosis and partial decrease in state 3 respiration, respectively. HF group displayed an intermediate degree of damage as it showed 40% of hepatocytes with microvesicular steatosis and diminution of both state 3 respiration and complex I activity. HF + Fr group displayed more severe damage as showed microvesicular steatosis in 60% of hepatocytes and inflammation, while mitochondria exhibited fully inhibited state 3 respiration, impaired complex I activity and increased ROS generation. Exacerbation of mitochondrial lipid peroxidation was observed in both the Fr and HF + Fr groups. CONCLUSION: Severity of liver injury induced by fructose or fat was related to the degree of dysfunction and oxidative damage in mitochondria. Attention should be paid on the serious effects observed in the HF + Fr group as the typical Western diet is rich in both fat and carbohydrates.
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Frutose/administração & dosagem , Inflamação/metabolismo , Hepatopatia Gordurosa não Alcoólica/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Animais , Dieta Hiperlipídica/efeitos adversos , Gorduras na Dieta/administração & dosagem , Gorduras na Dieta/efeitos adversos , Suplementos Nutricionais/efeitos adversos , Frutose/efeitos adversos , Hepatócitos/efeitos dos fármacos , Humanos , Inflamação/etiologia , Inflamação/patologia , Peroxidação de Lipídeos/efeitos dos fármacos , Fígado/efeitos dos fármacos , Fígado/lesões , Fígado/patologia , Mitocôndrias Hepáticas/efeitos dos fármacos , Mitocôndrias Hepáticas/patologia , Hepatopatia Gordurosa não Alcoólica/etiologia , Hepatopatia Gordurosa não Alcoólica/patologia , RatosRESUMO
The aim of this research study was to understand the mechanism of action of Salvia officinalis (Lamiaceae) essential oil (EO) on Aedes aegypti larvae. We evaluated the effect on DNA damage, acetylcholinesterase (AChE) inhibition and mitochondrial enzymatic alterations. The major components were analyzed in silico using OSIRIS and Molispiration free software. Aedes aegypti DNA was extracted from mosquito larvae between third (L3) and fourth (L4) instars to determine the DNA fragmentation or degradation at S. officinalis EO lethal concentrations (LC10, LC20, LC50, and LC90). DNA integrity was assessed in both LCs in larvae treated for 24â¯h and in larvae homogenized with EO; we also assessed purified DNA larvae by a densitometric analysis. The AChE inhibition was quantified in protein larvae L3-L4 following Ellman's method and the enzymatic activities related to the mitochondrial respiratory chain of mitochondrial proteins was estimated by spectrophotometry. In silico analysis of 1,8-cineol and of α-thujone, major EO components, showed that they were highly permeable in biological membranes without mutagenic risks. Alterations in the integrity of DNA were observed in larvae exposed and homogenized with S. officinalis EO. The EO induced an AChE inhibition of 37⯱â¯2.6% to IC50. On the other hand, mitochondrial bioenergetics suggest that EO inhibits electrons entry to the respiratory chain, via Complex II. AChE activity alteration causes mortality of individuals, by blocking the insect cholinergic functions. These results indicate that EO affects the integrity of DNA, the mitochondrial respiration chain and the AChE activity.
Assuntos
Aedes/efeitos dos fármacos , Inibidores da Colinesterase/farmacologia , Óleos Voláteis/farmacologia , Óleos de Plantas/farmacologia , Salvia officinalis/química , Animais , Inibidores da Colinesterase/química , Dano ao DNA/efeitos dos fármacos , Inseticidas/química , Inseticidas/farmacologia , Larva/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Óleos Voláteis/química , Folhas de Planta/química , Óleos de Plantas/químicaRESUMO
We assessed the utility of near-infrared spectroscopy to evaluate neonates with mitochondrial disorders. We observed abnormally high cerebral oxygen saturation levels indicating insufficient tissue oxygen utilization. We propose that near-infrared spectroscopy may be an additional tool in the diagnostic evaluation of a suspected mitochondrial disorder.
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Unidades de Terapia Intensiva Neonatal , Doenças Mitocondriais/diagnóstico por imagem , Espectroscopia de Luz Próxima ao Infravermelho , Encéfalo/diagnóstico por imagem , Circulação Cerebrovascular , Eletroencefalografia , Feminino , Idade Gestacional , Humanos , Recém-Nascido , Terapia Intensiva Neonatal , Ácido Láctico/sangue , Masculino , Doenças Mitocondriais/genética , Oximetria , Oxigênio/metabolismo , PerfusãoRESUMO
New molecular hybrids were synthesized by combining tetrahydroquinoline (THQ) and isoxazole (ISX) scaffolds, in search for chemical structures with improved pharmacological properties. Our tetrahydroquinoline (THQ) and isoxazole (ISX) hybrids differ in the X and Y substituents: FM53 (Xâ¯=â¯H; Y= H), FM49 (Xâ¯=â¯CH3; Y= OCH3), FM50 (Xâ¯=â¯Cl; Y= H) and FM48 (Xâ¯=â¯Cl; Y= OCH3). Aiming at exploring their bioactivity in liver cancer cells, in this paper we report the effect of four THQ-ISX hybrids on viability, respiration and oxidative stress in Hep-G2 human hepatoma cells. In addition, we measured the alterations induced by these compounds on oxygen uptake and respiratory chain enzymes in isolated mitochondria. Cell viability assay indicated that these THQ-ISX hybrids displayed antiproliferative activity on Hep-G2 cells. Among these, FM50 (IC50â¯=â¯5.2⯱â¯1.9⯵M) and FM53 (IC50â¯=â¯6.8⯱â¯0.7⯵M) had the highest cytotoxicity. These four hybrids also inhibited the Hep-G2 cells respiration in the uncoupled state, with FM50 decreasing all respiratory states (basal, leak, uncoupled). While only FM49 and FM53 altered the Hep-G2 cells redox function. In terms of mitochondrial bioenergetics, THQ-ISX hybrids decreased the oxygen consumption in state 3 (via complex I and II), and also inhibited NADH oxidase and NADH cytochrome c reductase enzyme activities. In these experiments, the structural homologues FM50 and FM53 had a remarkable inhibitory effect (~50%) with respect to FM49 and FM48. These results show that THQ-ISX hybrids are promising compounds for hepatoma cancer treatment and that the phenyl substituent (Y= H) in the ISX scaffold intensifies both, the cytotoxicity in Hep-G2 cells and, inhibition of electron transport through complex I of the mitochondrial respiratory chain.
Assuntos
Metabolismo Energético/efeitos dos fármacos , Isoxazóis/química , Mitocôndrias Hepáticas/metabolismo , Quinolinas/química , Animais , Antineoplásicos/química , Antineoplásicos/metabolismo , Antineoplásicos/farmacologia , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patologia , Sobrevivência Celular/efeitos dos fármacos , Células Hep G2 , Humanos , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patologia , Masculino , Complexos Multienzimáticos/metabolismo , NADH NADPH Oxirredutases/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Ratos , Ratos WistarRESUMO
Microcin J25 (MccJ25), an antimicrobial peptide, targets the respiratory chain but the exact mechanism by which it does so remains unclear. Here, we reveal that MccJ25 is able to inhibit the enzymatic activity of the isolated cytochrome bd-I from E. coli and induces at the same time production of reactive oxygen species. MccJ25 behaves as a dose-dependent weak inhibitor. Intriguingly, MccJ25 is capable of producing a change in the oxidation state of cytochrome bd-I causing its partial reduction in the presence of cyanide. These effects are specific for cytochrome bd-I, since the peptide is not able to act on purified cytochrome bo3.
Assuntos
Antibacterianos/farmacologia , Bacteriocinas/farmacologia , Citocromos/metabolismo , Complexo de Proteínas da Cadeia de Transporte de Elétrons/metabolismo , Proteínas de Escherichia coli/metabolismo , Escherichia coli/enzimologia , Oxirredutases/antagonistas & inibidores , Oxirredutases/metabolismo , Cianetos/farmacologia , Grupo dos Citocromos b , Citocromos/antagonistas & inibidores , Citocromos/genética , Complexo de Proteínas da Cadeia de Transporte de Elétrons/antagonistas & inibidores , Complexo de Proteínas da Cadeia de Transporte de Elétrons/genética , Escherichia coli/efeitos dos fármacos , Proteínas de Escherichia coli/antagonistas & inibidores , Proteínas de Escherichia coli/genética , Oxirredução , Oxirredutases/genética , Espécies Reativas de Oxigênio/metabolismoRESUMO
Crude oil (CO) is a super mixture of chemical compounds whose toxic effects are reported in fish species according to international guidelines. In the current study a proteomic analysis of oxidized proteins (ox) was performed on the brain and liver of Nile tilapia exposed to WAF obtained from relevant environmental loads (0.01, 0.1 and 1.0â¯g/L) of Maya CO. Results have shown that oxidation of specific proteins was a newly discovered organ-dependent process able to disrupt key functions in Nile tilapia. In control fish, enzymes involved on aerobic metabolism (liver aldehyde dehydrogenase and brain dihydrofolate reductase) and liver tryptophan--tRNA ligase were oxidized. In WAF-treated liver specimens, fructose-bisphosphate aldolase (FBA), ß-galactosidase (ß-GAL) and dipeptidyl peptidase 9 (DPP-9) were detected in oxidized form. oxDPP-9 could be favorable by reducing the risk associated with altered glucose metabolism, the opposite effects elicited by oxFBA and oxß-GAL. oxTrypsin showed a clear adverse effect by reducing probably the hepatocyte capacity to achieve proteolysis of oxidized proteins as well as for performing the proper digestive function. Additionally, enzyme implicated in purine metabolism adenosine (deaminase) was oxidized. Cerebral enzymes of mitochondrial respiratory chain complex (COX IV, COX5B), of glycosphingolipid biosynthesis (ß-N-acetylhexosaminidase), involved in catecholamines degradation (catechol O-methyltransferase), and microtubule cytoskeleton (stathmin) were oxidized in WAF-treated specimens. This response suggests, in the brain, an adverse scenario for the mitochondrial respiration process and for ATP provision as for ischemia/reoxygenation challenges. Proteomic analysis of oxidized proteins is a promising tool for monitoring environmental quality influenced by hydrocarbons dissolved in water.
Assuntos
Encéfalo/efeitos dos fármacos , Ciclídeos , Fígado/efeitos dos fármacos , Petróleo/toxicidade , Proteoma , Poluentes Químicos da Água/toxicidade , Animais , Encéfalo/metabolismo , Catalase/metabolismo , Catecolaminas/metabolismo , Monitoramento Ambiental , Glutationa Peroxidase/metabolismo , Glicoesfingolipídeos/metabolismo , Peroxidação de Lipídeos , Fígado/metabolismo , Microtúbulos/metabolismo , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Proteólise , Espécies Reativas de Oxigênio/metabolismo , Estatmina/metabolismo , Superóxido Dismutase/metabolismoRESUMO
Mitochondrial dysfunction, a common factor in several diseases is accompanied with reactive oxygen species (ROS) production. These molecules react with proteins and lipids at their site of generation, establishing a vicious cycle which might result in further mitochondrial injury. It is well established that mitochondrial respiratory complexes can be organized into supramolecular structures called supercomplexes (SCs) or respirasomes; yet, the physiological/pathological relevance of these structures remains unresolved. Changes in their stabilization and content have been documented in Barth's syndrome, degenerative diseases such as Parkinson's and Alzheimer, cardiovascular diseases including heart failure and ischemia-reperfusion damage, as well as in aging. Under pathological conditions, SCs stability could have relevant biomedical implications or might be used as a reliable marker of mitochondrial damage. The purpose of this review is to recapitulate the current state of the significance on mitochondrial bioenergetics of these structures and their possible role in pathophysiologies related with ROS increase.
Assuntos
Envelhecimento/metabolismo , Doença de Alzheimer/enzimologia , Síndrome de Barth/enzimologia , Complexo de Proteínas da Cadeia de Transporte de Elétrons/metabolismo , Mitocôndrias/enzimologia , Membranas Mitocondriais/metabolismo , Doença de Parkinson/enzimologia , Envelhecimento/patologia , Doença de Alzheimer/patologia , Animais , Síndrome de Barth/patologia , Metabolismo Energético , Humanos , Membranas Mitocondriais/patologia , Doença de Parkinson/patologia , Espécies Reativas de Oxigênio/metabolismoRESUMO
Electron leakage from dysfunctional respiratory chain and consequent superoxide formation leads to mitochondrial and cell injury during ischemia and reperfusion (IR). In this work we evaluate if the supramolecular assembly of the respiratory complexes into supercomplexes (SCs) is associated with preserved energy efficiency and diminished oxidative stress in post-ischemic hearts treated with the antioxidant N-acetylcysteine (NAC) and the cardioprotective maneuver of Postconditioning (PostC). Hemodynamic variables, infarct size, oxidative stress markers, oxygen consumption and the activity/stability of SCs were compared between groups. We found that mitochondrial oxygen consumption and the activity of respiratory complexes are preserved in mitochondria from reperfused hearts treated with both NAC and PostC. Both treatments contribute to recover the activity of individual complexes. NAC reduced oxidative stress and maintained SCs assemblies containing Complex I, Complex III, Complex IV and the adapter protein SCAFI more effectively than PostC. On the other hand, the activities of CI, CIII and CIV associated to SCs assemblies were preserved by this maneuver, suggesting that the activation of other cardioprotective mechanisms besides oxidative stress contention might participate in maintaining the activity of the mitochondrial respiratory complexes in such superstructures. We conclude that both the monomeric and the SCs assembly of the respiratory chain contribute to the in vivo functionality of the mitochondria. However, although the ROS-induced damage and the consequent increased production of ROS affect the assembly of SCs, other levels of regulation as those induced by PostC, might participate in maintaining the activity of the respiratory complexes in such superstructures.