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Significance: Mitochondria play a critical role in the physiology of the heart by controlling cardiac metabolism, function, and remodeling. Accumulation of fragmented and damaged mitochondria is a hallmark of cardiac diseases. Recent Advances: Disruption of quality control systems that maintain mitochondrial number, size, and shape through fission/fusion balance and mitophagy results in dysfunctional mitochondria, defective mitochondrial segregation, impaired cardiac bioenergetics, and excessive oxidative stress. Critical Issues: Pharmacological tools that improve the cardiac pool of healthy mitochondria through inhibition of excessive mitochondrial fission, boosting mitochondrial fusion, or increasing the clearance of damaged mitochondria have emerged as promising approaches to improve the prognosis of heart diseases. Future Directions: There is a reasonable amount of preclinical evidence supporting the effectiveness of molecules targeting mitochondrial fission and fusion to treat cardiac diseases. The current and future challenges are turning these lead molecules into treatments. Clinical studies focusing on acute (i.e., myocardial infarction) and chronic (i.e., heart failure) cardiac diseases are needed to validate the effectiveness of such strategies in improving mitochondrial morphology, metabolism, and cardiac function. Antioxid. Redox Signal. 36, 844-863.
Asunto(s)
Insuficiencia Cardíaca , Infarto del Miocardio , Insuficiencia Cardíaca/metabolismo , Humanos , Mitocondrias/metabolismo , Dinámicas Mitocondriales , Mitofagia , Infarto del Miocardio/metabolismoRESUMEN
Extensive use of neonicotinoids insecticides (NNIs) rapidly garnered widespread attention in the toxicology, since they have been found in human samples, including urine, blood, breast milk and hair. However, the precise mechanism is not completely clear regarding the NNIs-induced hepatotoxicity. In this study, we exposed male mice to three neonicotinoids (dinotefuran (DIN), nitenpyram (NIT) and acetamiprid (ACET) for 30 days. Our results showed that NNIs remarkably induced morphological damage in the liver. Simultaneously, we found that three neonicotinoids could activate the store operated Ca2+ entry (SOCE) in the liver. Further results confirmed that reactive oxide species (ROS) scavenger n-acetylcysteine (NAC) attenuated DIN-induced calcium ion (Ca2+) overload and S-phase arrest via restoring protein expression of SOCE and S phase related genes in L02 hepatocytes. Moreover, we found that NAC obviously combated mitochondrial dysfunction caused by DIN via restoring mitochondrial membrane potential. Meanwhile, DIN treatment significantly increased pyruvate content, impaired the activities of tricarboxylic acid (TCA) cycle rate-limiting enzymes and inhibited adenosine triphosphate (ATP) generation, but these effects were reversed by Serca specific activator CDN1163. Collectively, perturbation of redox states can be recognized as the center of S-phase arrest and Ca2+ overload after NNIs exposure. In this regard, Ca2+ homeostasis dysregulation is a causative event of mitochondrial bioenergetic dysfunction in the liver. These data provides a new perspective for understanding NNI-induced hepatotoxicity mechanisms.
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Dietary polyphenols act in cancer prevention and may inhibit carcinogenesis. A possible mitochondrial mechanism for carcinogen-induced neoplastic transformation and chemoprevention by polyphenols, however, is largely unexplored. Using the Bhas 42 cell model of carcinogen-induced neoplastic transformation, we investigated benzo[a]pyrene (B[a]P) along with different polyphenols for their effects on mitochondrial content and function, and on mitochondrial and intracellular ROS generation. Bhas 42 cells were either co-treated with 5 µM polyphenol starting 2 h before exposure to 4 µM B[a]P for 24 or 72 h, or pre-treated with polyphenol for 24 h and removed prior to B[a]P exposure. Exposure to B[a]P decreased mitochondrial content (by 46% after 24 h and 30% after 72 h), decreased mitochondrial membrane potential and cellular ATP, and increased generation of mitochondrial superoxide and intracellular ROS. Polyphenol co-treatments protected against the decreased mitochondrial content, with resveratrol being the most effective (increasing the mitochondrial content after 72 h by 75%). Measurements after 24 h of mRNA for mitochondria-related proteins and of SIRT1 enzyme activity suggested an involvement of increased mitochondrial biogenesis in the polyphenol effects. The polyphenol co-treatments also ameliorated B[a]P-induced deficits in mitochondrial function (most strongly resveratrol), and increases in generation of mitochondrial superoxide and intracellular ROS. Notably, 24 h pre-treatments with polyphenols strongly suppressed subsequent B[a]P-induced increases, after 24 and 72 h, in mitochondrial superoxide and intracellular ROS generation, with resveratrol being the most effective. In conclusion, the results support a mechanism for B[a]P carcinogenesis involving impaired mitochondrial function and increased mitochondria-derived ROS, that can be ameliorated by dietary polyphenols. The evidence supports an increase in mitochondrial biogenesis behind the strong chemoprevention by resveratrol, and a mitochondrial antioxidant effect in chemoprevention by quercetin.
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Benzo(a)pireno , Estilbenos , Benzo(a)pireno/toxicidad , Flavonoides/metabolismo , Potencial de la Membrana Mitocondrial , Mitocondrias/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Resveratrol/metabolismo , Estilbenos/farmacologíaRESUMEN
Emerging scaffold structures made of carbon nanomaterials, such as graphene oxide (GO) have shown efficient bioconjugation with common biomolecules. Previous studies described that GO promotes the differentiation of neural stem cells and may be useful for neural regeneration. In this study, we examined the capacity of GO, full reduced (FRGO), and partially reduced (PRGO) powder and film to support survival, proliferation, differentiation, maturation, and bioenergetic function of a dopaminergic (DA) cell line derived from the mouse substantia nigra (SN4741). Our results show that the morphology of the film and the species of graphene (GO, PRGO, or FRGO) influences the behavior and function of these neurons. In general, we found better biocompatibility of the film species than that of the powder. Analysis of cell viability and cytotoxicity showed good cell survival, a lack of cell death in all GO forms and its derivatives, a decreased proliferation, and increased differentiation over time. Neuronal maturation of SN4741 in all GO forms, and its derivatives were assessed by increased protein levels of tyrosine hydroxylase (TH), dopamine transporter (DAT), the glutamate inward rectifying potassium channel 2 (GIRK2), and of synaptic proteins, such as synaptobrevin and synaptophysin. Notably, PRGO-film increased the levels of Tuj1 and the expression of transcription factors specific for midbrain DA neurons, such as Pitx3, Lmx1a, and Lmx1b. Bioenergetics and mitochondrial dysfunction were evaluated by measuring oxygen consumption modified by distinct GO species and were different between powder and film for the same GO species. Our results indicate that PRGO-film was the best GO species at maintaining mitochondrial function compared to control. Finally, different GO forms, and particularly PRGO-film was also found to prevent the loss of DA cells and the decrease of the α-synuclein (α-syn) in a molecular environment where oxidative stress has been induced to model Parkinson's disease. In conclusion, PRGO-film is the most efficient graphene species at promoting DA differentiation and preventing DA cell loss, thus becoming a suitable scaffold to test new drugs or develop constructs for Parkinson's disease cell replacement therapy.
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TIMM50 is an essential component of the TIM23 complex, the mitochondrial inner membrane machinery that imports cytosolic proteins containing a mitochondrial targeting presequence into the mitochondrial inner compartment. Whole exome sequencing (WES) identified compound heterozygous pathogenic mutations in TIMM50 in an infant patient with rapidly progressive, severe encephalopathy. Patient fibroblasts presented low levels of TIMM50 and other components of the TIM23 complex, lower mitochondrial membrane potential, and impaired TIM23-dependent protein import. As a consequence, steady-state levels of several components of mitochondrial respiratory chain were decreased, resulting in decreased respiration and increased ROS production. Growth of patient fibroblasts in galactose shifted energy production metabolism toward oxidative phosphorylation (OxPhos), producing an apparent improvement in most of the above features but also increased apoptosis. Complementation of patient fibroblasts with TIMM50 improved or restored these features to control levels. Moreover, RNASEH1 and ISCU mutant fibroblasts only shared a few of these features with TIMM50 mutant fibroblasts. Our results indicate that mutations in TIMM50 cause multiple mitochondrial bioenergetic dysfunction and that functional TIMM50 is essential for cell survival in OxPhos-dependent conditions.
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Encefalopatías/fisiopatología , Proteínas de Transporte de Membrana/genética , Enfermedades Mitocondriales/fisiopatología , Mutación , Fosforilación Oxidativa , Encefalopatías/diagnóstico , Encefalopatías/patología , Supervivencia Celular , Células Cultivadas , Femenino , Fibroblastos/patología , Prueba de Complementación Genética , Humanos , Lactante , Italia , Enfermedades Mitocondriales/diagnóstico , Enfermedades Mitocondriales/patología , Proteínas del Complejo de Importación de Proteínas Precursoras MitocondrialesRESUMEN
Chronic Progressive External Ophthalmoplegia (CPEO) is characterized by ptosis and ophthalmoplegia and is usually caused by mitochondrial DNA (mtDNA) deletions or mt-tRNA mutations. The aim of the present work was to clarify the genetic defect in a patient presenting with CPEO and elucidate the underlying pathogenic mechanism. This 62-year-old female first developed ptosis of the right eye at the age of 12 and subsequently the left eye at 45 years, and was found to have external ophthalmoplegia at the age of 55 years. Histopathological abnormalities were detected in the patient's muscle, including ragged-red fibres, a mosaic pattern of COX-deficient muscle fibres and combined deficiency of respiratory chain complexes I and IV. Genetic investigation revealed the "common deletion" in the patient's muscle and fibroblasts. Moreover, a novel, heteroplasmic mt-tRNASer(UCN) variant (m.7486G>A) in the anticodon loop was detected in muscle homogenate (50%), fibroblasts (11%) and blood (4%). Single-fibre analysis showed segregation with COX-deficient fibres for both genetic alterations. Assembly defects of mtDNA-encoded complexes were demonstrated in fibroblasts. Functional analyses showed significant bioenergetic dysfunction, reduction in respiration rate and ATP production and mitochondrial depolarization. Multilamellar bodies were detected by electron microscopy, suggesting disturbance in autophagy. In conclusion, we report a CPEO patient with two possible genetic origins, both segregating with biochemical and histochemical defect. The "common mtDNA deletion" is the most likely cause, yet the potential pathogenic effect of a novel mt-tRNASer(UCN) variant cannot be fully excluded.
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ADN Mitocondrial/genética , Mutación/genética , Eliminación de Secuencia/genética , Succinato Deshidrogenasa/genética , Femenino , Humanos , Persona de Mediana Edad , Mitocondrias/genética , Mitocondrias/patología , Fibras Musculares Esqueléticas/patología , Músculo Esquelético/patología , Succinato Deshidrogenasa/metabolismoRESUMEN
AIM: Owing to their catalytic properties as reactive oxygen species scavengers, cerium oxide nanoparticles (nanoceria) have become an extremely promising candidate for medical applications, especially in the treatment of diseases where oxidative stress has been proposed as one of the main pathogenesis factors. MATERIALS & METHODS: In this work, nanoceria antioxidant power has been tested in primary cultured skin fibroblasts, derived from healthy individuals, by evaluating the mitochondrial function both in basal condition and after an oxidative insult. RESULTS & CONCLUSION: Combined with a clear lack of toxicity, antioxidant activity makes nanoceria promising in a wide range of clinical applications sharing the common signature of a global bioenergetic dysfunction.
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Antioxidantes/administración & dosificación , Antioxidantes/farmacología , Cerio/uso terapéutico , Portadores de Fármacos/química , Fibroblastos/efectos de los fármacos , Nanopartículas/química , Adulto , Células Cultivadas , Cerio/farmacología , Metabolismo Energético/efectos de los fármacos , Femenino , Fibroblastos/metabolismo , Humanos , Masculino , Persona de Mediana Edad , Mitocondrias/efectos de los fármacos , Mitocondrias/metabolismo , Nanopartículas/ultraestructura , Oxidación-Reducción/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , Especies Reactivas de Oxígeno/metabolismoRESUMEN
Accumulation of glycine (GLY) is the biochemical hallmark of glycine encephalopathy (GE), an aminoacidopathy characterized by severe neurological dysfunction that may lead to early death. In the present study, we evaluated the effect of a single intracerebroventricular administration of GLY on bioenergetics, redox homeostasis, and histopathology in brain of neonatal rats. Our results demonstrated that GLY decreased the activities of the respiratory chain complex IV and creatine kinase, induced reactive species generation, and diminished glutathione (GSH) levels 1, 5, and 10 days after GLY injection in cerebral cortex of 1-day-old rats. GLY also increased malondialdehyde (MDA) levels 5 days after GLY infusion in this brain region. Furthermore, GLY differentially modulated the activities of superoxide dismutase, catalase, and glutathione peroxidase depending on the period tested after GLY administration. In contrast, bioenergetics and redox parameters were not altered in brain of 5-day-old rats. Regarding the histopathological analysis, GLY increased S100ß staining in cerebral cortex and striatum, and GFAP in corpus callosum of 1-day-old rats 5 days after injection. Finally, we verified that melatonin prevented the decrease of complex IV and CK activities and GSH concentrations, and the increase of MDA levels and S100ß staining caused by GLY. Based on our findings, it may be presumed that impairment of redox and energy homeostasis and glial reactivity induced by GLY may contribute to the neurological dysfunction observed in GE.
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Corteza Cerebral/patología , Metabolismo Energético/efectos de los fármacos , Glicina/administración & dosificación , Homeostasis/efectos de los fármacos , Neuroglía/patología , Animales , Animales Recién Nacidos , Antioxidantes/metabolismo , Supervivencia Celular/efectos de los fármacos , Cuerpo Calloso/metabolismo , Creatina Quinasa/metabolismo , Complejo IV de Transporte de Electrones/metabolismo , Proteína Ácida Fibrilar de la Glía/metabolismo , Glutatión/metabolismo , Inyecciones Intraventriculares , Peroxidación de Lípido/efectos de los fármacos , Malondialdehído/metabolismo , Melatonina/farmacología , Neuroglía/efectos de los fármacos , Neuroglía/metabolismo , Oxidación-Reducción , Ratas Wistar , Especies Reactivas de Oxígeno/metabolismo , Proteínas S100/metabolismoRESUMEN
Sulfite oxidase (SO) deficiency is biochemically characterized by the accumulation of sulfite, thiosulfate and S-sulfocysteine in tissues and biological fluids of the affected patients. The main clinical symptoms include severe neurological dysfunction and brain abnormalities, whose pathophysiology is still unknown. The present study investigated the in vitro effects of sulfite and thiosulfate on mitochondrial homeostasis in rat brain mitochondria. It was verified that sulfite per se, but not thiosulfate, decreased state 3, CCCP-stimulated state and respiratory control ratio in mitochondria respiring with glutamate plus malate. In line with this, we found that sulfite inhibited the activities of glutamate and malate (MDH) dehydrogenases. In addition, sulfite decreased the activity of a commercial solution of MDH, that was prevented by antioxidants and dithiothreitol. Sulfite also induced mitochondrial swelling and reduced mitochondrial membrane potential, Ca(2+) retention capacity, NAD(P)H pool and cytochrome c immunocontent when Ca(2+) was present in the medium. These alterations were prevented by ruthenium red, cyclosporine A (CsA) and ADP, supporting the involvement of mitochondrial permeability transition (MPT) in these effects. We further observed that N-ethylmaleimide prevented the sulfite-elicited swelling and that sulfite decreased free thiol group content in brain mitochondria. These findings indicate that sulfite acts directly on MPT pore containing thiol groups. Finally, we verified that sulfite reduced cell viability in cerebral cortex slices and that this effect was prevented by CsA. Therefore, it may be presumed that disturbance of mitochondrial energy homeostasis and MPT induced by sulfite could be involved in the neuronal damage characteristic of SO deficiency.
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Encéfalo/efectos de los fármacos , Metabolismo Energético/efectos de los fármacos , Homeostasis/efectos de los fármacos , Mitocondrias/efectos de los fármacos , Proteínas de Transporte de Membrana Mitocondrial/efectos de los fármacos , Compuestos de Sulfhidrilo/química , Sulfitos/farmacología , Errores Innatos del Metabolismo de los Aminoácidos/metabolismo , Errores Innatos del Metabolismo de los Aminoácidos/patología , Animales , Encéfalo/metabolismo , Proliferación Celular , Citocromos c/metabolismo , Immunoblotting , Masculino , Potencial de la Membrana Mitocondrial/efectos de los fármacos , Mitocondrias/metabolismo , Mitocondrias Hepáticas/efectos de los fármacos , Mitocondrias Hepáticas/metabolismo , Proteínas de Transporte de Membrana Mitocondrial/metabolismo , Poro de Transición de la Permeabilidad Mitocondrial , NADP/metabolismo , Consumo de Oxígeno/efectos de los fármacos , Ratas , Ratas Wistar , Compuestos de Sulfhidrilo/metabolismo , Sulfito-Oxidasa/deficiencia , Sulfito-Oxidasa/metabolismoRESUMEN
Sulfite oxidase (SO) deficiency is biochemically characterized by tissue accumulation and high urinary excretion of sulfite, thiosulfate and S-sulfocysteine. Affected patients present severe neurological symptoms and cortical atrophy, whose pathophysiology is still poorly established. Therefore, in the present work we investigated the in vitro effects of sulfite and thiosulfate on important parameters of energy metabolism in the brain of young rats. We verified that sulfite moderately inhibited the activity of complex IV, whereas thiosulfate did not alter any of the activities of the respiratory chain complexes. It was also found that sulfite and thiosulfate markedly reduced the activity of total creatine kinase (CK) and its mitochondrial and cytosolic isoforms, suggesting that these metabolites impair brain cellular energy buffering and transfer. In contrast, the activity of synaptic Na(+),K(+)-ATPase was not altered by sulfite or thiosulfate. We also observed that the inhibitory effect of sulfite and thiosulfate on CK activity was prevented by melatonin, reduced glutathione and the combination of both antioxidants, as well as by the nitric oxide synthase N(ω)-nitro-l-arginine methyl ester, indicating the involvement of reactive oxygen and nitrogen species in these effects. Sulfite and thiosulfate also increased 2',7'-dichlorofluorescin oxidation and hydrogen peroxide production and decreased the activity of the redox sensor aconitase enzyme, reinforcing a role for oxidative damage in the effects elicited by these metabolites. It may be presumed that the disturbance of cellular energy and redox homeostasis provoked by sulfite and thiosulfate contributes to the neurological symptoms and abnormalities found in patients affected by SO deficiency.