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Sample records for oxidative stress-related mitochondrial

  1. Oxidative Stress Related Diseases in Newborns

    PubMed Central

    Aykac, Kubra

    2016-01-01

    We review oxidative stress-related newborn disease and the mechanism of oxidative damage. In addition, we outline diagnostic and therapeutic strategies and future directions. Many reports have defined oxidative stress as an imbalance between an enhanced reactive oxygen/nitrogen species and the lack of protective ability of antioxidants. From that point of view, free radical-induced damage caused by oxidative stress seems to be a probable contributing factor to the pathogenesis of many newborn diseases, such as respiratory distress syndrome, bronchopulmonary dysplasia, periventricular leukomalacia, necrotizing enterocolitis, patent ductus arteriosus, and retinopathy of prematurity. We share the hope that the new understanding of the concept of oxidative stress and its relation to newborn diseases that has been made possible by new diagnostic techniques will throw light on the treatment of those diseases. PMID:27403229

  2. Mitochondrial oxidative stress and mitochondrial DNA.

    PubMed

    Kang, Dongchon; Hamasaki, Naotaka

    2003-10-01

    Mitochondria produce reactive oxygen species (ROS) under physiological conditions in association with activity of the respiratory chain in aerobic ATP production. The production of ROS is essentially a function of O2 consumption. Hence, increased mitochondrial activity per se can be an oxidative stress to cells. Furthermore, production of ROS is markedly enhanced in many pathological conditions in which the respiratory chain is impaired. Because mitochondrial DNA, which is essential for execution of normal oxidative phosphorylation, is located in proximity to the ROS-generating respiratory chain, it is more oxidatively damaged than is nuclear DNA. Cumulative damage of mitochondrial DNA is implicated in the aging process and in the progression of such common diseases as diabetes, cancer, and heart failure.

  3. Signal Transduction by Mitochondrial Oxidants*

    PubMed Central

    Finkel, Toren

    2012-01-01

    The production of mitochondrial reactive oxygen species occurs as a consequence of aerobic metabolism. Mitochondrial oxidants are increasingly viewed less as byproducts of metabolism and more as important signaling molecules. Here, I review several notable examples, including the cellular response to hypoxia, aspects of innate immunity, the regulation of autophagy, and stem cell self-renewal capacity, where evidence suggests an important regulatory role for mitochondrial oxidants. PMID:21832045

  4. Oxidative Stress-Related Mechanisms and Antioxidant Therapy in Diabetic Retinopathy

    PubMed Central

    Miao, Xiao

    2017-01-01

    Diabetic retinopathy (DR) is one of the most common microvascular complications of diabetes and is the leading cause of blindness in young adults. Oxidative stress has been implicated as a critical cause of DR. Metabolic abnormalities induced by high-glucose levels are involved in the development of DR and appear to be influenced by oxidative stress. The imbalance between reactive oxygen species (ROS) production and the antioxidant defense system activates several oxidative stress-related mechanisms that promote the pathogenesis of DR. The damage caused by oxidative stress persists for a considerable time, even after the blood glucose concentration has returned to a normal level. Animal experiments have proved that the use of antioxidants is a beneficial therapeutic strategy for the treatment of DR, but more data are required from clinical trials. The aims of this review are to highlight the improvements to our understanding of the oxidative stress-related mechanisms underlying the development of DR and provide a summary of the main antioxidant therapy strategies used to treat the disease. PMID:28265339

  5. Integrated Approaches to Drug Discovery for Oxidative Stress-Related Retinal Diseases

    PubMed Central

    Hara, Hideaki

    2016-01-01

    Excessive oxidative stress induces dysregulation of functional networks in the retina, resulting in retinal diseases such as glaucoma, age-related macular degeneration, and diabetic retinopathy. Although various therapies have been developed to reduce oxidative stress in retinal diseases, most have failed to show efficacy in clinical trials. This may be due to oversimplification of target selection for such a complex network as oxidative stress. Recent advances in high-throughput technologies have facilitated the collection of multilevel omics data, which has driven growth in public databases and in the development of bioinformatics tools. Integration of the knowledge gained from omics databases can be used to generate disease-related biological networks and to identify potential therapeutic targets within the networks. Here, we provide an overview of integrative approaches in the drug discovery process and provide simple examples of how the approaches can be exploited to identify oxidative stress-related targets for retinal diseases. PMID:28053689

  6. Antioxidant capacities of flavones and benefits in oxidative-stress related diseases.

    PubMed

    Catarino, Marcelo D; Alves-Silva, Jorge M; Pereira, Olivia R; Cardoso, Susana M

    2015-01-01

    Flavonoids, a group of secondary metabolites widely distributed in the plant kingdom, have been acknowledged for their interesting medicinal properties. Among them, natural flavones, as well as some of their synthetic derivatives, have been shown to exhibit several biological activities, including antioxidant, anti-inflammatory, antitumor, anti-allergic, neuroprotective, cardioprotective and antimicrobial. The antioxidant properties of flavones allow them to demonstrate potential application as preventive and attenuating agents in oxidative stress, i.e., a biological condition that is closely associated to aging process and several diseases. Some flavones interfere in distinct oxidative-stress related events by directly reducing the levels of intracellular free radicals (hydroxyl, superoxide and nitric oxide) and/or of reactive species (e.g. hydrogen peroxide, peroxynitrite and hypochlorous acid) thus preventing their amplification and the consequent damage of other biomolecules such as lipids, proteins and DNA. Flavones can also hinder the activity of central free radical-producing enzymes, such as xanthine oxidase and nicotinamide adenine dinucleotide phosphate oxidase (NADPH-oxidase) or inducible nitric oxide synthase (iNOS) and can even modulate the intracellular levels of pro-oxidant and/or antioxidant enzymes. The evaluation of flavones antioxidant ability has been extensively determined in chemical or biological in vitro models, but in vivo therapy with individual flavones or with flavones-enriched extracts has also been reported. The present manuscript revises relevant studies focusing the preventive effects of flavones on stress-related diseases, namely the neurological and cardiovascular diseases, and diabetes and its associated complications.

  7. Oxidative Stress-Related Genetic Variants May Modify Associations of Phthalate Exposures with Asthma

    PubMed Central

    Wang, I-Jen; Karmaus, Wilfried J. J.

    2017-01-01

    Background: Phthalate exposure may increase the risk of asthma. Little is known about whether oxidative-stress related genes may alter this association. First, this motivated us to investigate whether genetic polymorphisms of the oxidative-stress related genes glutathione S-transferase Mu 1 (GSTM1), glutathione S-transferase pi 1 (GSTP1), superoxide dismutase 2 (SOD2), catalase (CAT), myeloperoxidase (MPO), and EPHX1 in children are associated with phthalate urine concentrations. Second, we addressed the question whether these genes may affect the influence of phthalates on asthma. Methods: In a case-control study composed of 126 asthmatic children and 327 controls, urine phthalate metabolites (monoethyl phthalate (MEP), monobutyl phthalate (MBP), monobenzyl phthalate (MBzP), and mono(2-ethyl-5-hydroxyhexyl)phthalate (MEHHP) were measured by UPLC-MS/MS at age 3. Genetic variants were analyzed by TaqMan assay. Information on asthma and environmental exposures was also collected. Analyses of variance and logistic regressions were performed. Results: Urine MEHHP levels were associated with asthma (adjusted OR 1.33, 95% CI (1.11–1.60). Children with the GSTP1 (rs1695) AA and SOD2 (rs5746136) TT genotypes had higher MEHHP levels as compared to GG and CC types, respectively. Since only SOD2 TT genotype was significantly associated with asthma (adjusted OR (95% CI): 2.78 (1.54–5.02)), we estimated whether SOD2 variants modify the association of MEHHP levels and asthma. As MEHHP concentrations were dependent on GSTP1 and SOD2, but the assessment of interaction requires independent variables, we estimated MEHHP residuals and assessed their interaction, showing that the OR for SOD2 TT was further elevated to 3.32 (1.75–6.32) when the residuals of MEHHP were high. Conclusions: Urine phthalate metabolite concentrations are associated with oxidative-stress related genetic variants. Genetic variants of SOD2, considered to be reflect oxidative stress metabolisms, might

  8. The cyclophilin D/Drp1 axis regulates mitochondrial fission contributing to oxidative stress-induced mitochondrial dysfunctions in SH-SY5Y cells.

    PubMed

    Xiao, Anqi; Gan, Xueqi; Chen, Ruiqi; Ren, Yanming; Yu, Haiyang; You, Chao

    2017-01-29

    Oxidative stress plays a central role in the pathogenesis of various neurodegenerative diseases. Increasing evidences have demonstrated that structural abnormalities in mitochondria are involved in oxidative stress related nerve cell damage. And Drp1 plays a critical role in mitochondrial dynamic imbalance insulted by oxidative stress-derived mitochondria. However, the status of mitochondrial fusion and fission pathway and its relationship with mitochondrial properties such as mitochondrial membrane permeability transition pore (mPTP) have not been fully elucidated. Here, we demonstrated for the first time the role of Cyclophilin D (CypD), a crucial component for mPTP formation, in the regulation of mitochondrial dynamics in oxidative stress treated nerve cell. We observed that CypD-mediated phosphorylation of Drp1 and subsequently augmented Drp1 recruitment to mitochondria and shifts mitochondrial dynamics toward excessive fission, which contributes to the mitochondrial structural and functional dysfunctions in oxidative stress-treated nerve cells. CypD depletion or over expression accompanies mitochondrial dynamics/functions recovery or aggravation separately. We also demonstrated first time the link between the CypD to mitochondrial dynamics. Our data offer new insights into the mechanism of mitochondrial dynamics which contribute to the mitochondrial dysfunctions, specifically the role of CypD in Drp1-mediated mitochondrial fission. The protective effect of CsA, or other molecules affecting the function of CypD hold promise as a potential novel therapeutic strategy for governing oxidative stress pathology via mitochondrial pathways.

  9. Oxidative Stress in Inherited Mitochondrial Diseases

    PubMed Central

    Hayashi, Genki; Cortopassi, Gino

    2015-01-01

    Mitochondria are a source of reactive oxygen species (ROS). Mitochondrial diseases are the result of inherited defects in mitochondrially-expressed genes. One potential pathomechanism for mitochondrial disease is oxidative stress. Oxidative stress can occur as the result of increased ROS production, or decreased ROS protection. The role of oxidative stresses in the five most common inherited mitochondrial diseases; Friedreich's ataxia (FA), LHON, MELAS, MERRF and Leigh Syndrome (LS) is discussed. Published reports for oxidative stress involvement in pathomechanism in these five mitochondrial diseases are reviewed. The strongest for oxidative stress pathomechanism among the five diseases was in Friedreich's ataxia. In addition, a meta-analysis was carried out to provide an unbiased evaluation of the role of oxidative stress in the five diseases, by searching for oxidative stress citation count frequency within each disease. Of the five most common mitochondrial diseases, the strongest support for oxidative stress is in Friedreich's ataxia (6.42%), followed by LHON (2.45%), MELAS (2.18%), MERRF (1.71%), and LS (1.03%). The increased frequency of oxidative stress citations was significant relative to the mean of the total pool of five diseases (p<0.01) and the mean of the four non-Friedreich's diseases (p<0.0001). Thus there is support for oxidative stress in all five most common mitochondrial diseases, but the strongest, significant support is for Friedreich's ataxia. PMID:26073122

  10. Aspirin increases mitochondrial fatty acid oxidation.

    PubMed

    Uppala, Radha; Dudiak, Brianne; Beck, Megan E; Bharathi, Sivakama S; Zhang, Yuxun; Stolz, Donna B; Goetzman, Eric S

    2017-01-08

    The metabolic effects of salicylates are poorly understood. This study investigated the effects of aspirin on fatty acid oxidation. Aspirin increased mitochondrial long-chain fatty acid oxidation, but inhibited peroxisomal fatty acid oxidation, in two different cell lines. Aspirin increased mitochondrial protein acetylation and was found to be a stronger acetylating agent in vitro than acetyl-CoA. However, aspirin-induced acetylation did not alter the activity of fatty acid oxidation proteins, and knocking out the mitochondrial deacetylase SIRT3 did not affect the induction of long-chain fatty acid oxidation by aspirin. Aspirin did not change oxidation of medium-chain fatty acids, which can freely traverse the mitochondrial membrane. Together, these data indicate that aspirin does not directly alter mitochondrial matrix fatty acid oxidation enzymes, but most likely exerts its effects at the level of long-chain fatty acid transport into mitochondria. The drive on mitochondrial fatty acid oxidation may be a compensatory response to altered mitochondrial morphology and inhibited electron transport chain function, both of which were observed after 24 h incubation of cells with aspirin. These studies provide insight into the pathophysiology of Reye Syndrome, which is known to be triggered by aspirin ingestion in patients with fatty acid oxidation disorders.

  11. Oxidative stress-related genotypes, fruit and vegetable consumption and breast cancer risk.

    PubMed

    Li, Yulin; Ambrosone, Christine B; McCullough, Marjorie J; Ahn, Jiyoung; Stevens, Victoria L; Thun, Michael J; Hong, Chi-Chen

    2009-05-01

    Dietary antioxidants may interact with endogenous sources of pro- and antioxidants to impact breast cancer risk. A nested case-control study of postmenopausal women (505 cases and 502 controls) from the Cancer Prevention Study-II Nutrition Cohort was conducted to examine the interaction between oxidative stress-related genes and level of vegetable and fruit intake on breast cancer risk. Genetic variations in catalase (CAT) (C-262T), myeloperoxidase (MPO) (G-463A), endothelial nitric oxide synthase (NOS3) (G894T) and heme oxygenase-1 (HO-1) [(GT)(n) dinucleotide length polymorphism] were not associated with breast cancer risk. Women carrying the low-risk CAT CC [odds ratio (OR) = 0.75, 95% confidence interval (CI) 0.50-1.11], NOS3 TT (OR = 0.54, 95% CI = 0.26-1.12, P-trend = 0.10) or HO-1 S allele and MM genotype (OR = 0.56, 95% CI = 0.37-0.55), however, were found to be at non-significantly reduced breast cancer risk among those with high vegetable and fruit intake (> or = median; P-interactions = 0.04 for CAT, P = 0.005 for NOS3 and P = 0.07 for HO-1). Furthermore, those with > or = 4 putative low-risk alleles in total had significantly reduced risk (OR = 0.53, 95% CI = 0.32-0.88, P-interaction = 0.006) compared with those with < or = 2 low-risk alleles. In contrast, among women with low vegetable and fruit intake (< median), the low-risk CAT CC (OR = 1.33, 95% CI = 0.89-1.99), NOS3 TT (OR = 2.93, 95% CI = 1.38-6.22) and MPO AA (OR = 2.09, 95% CI = 0.73-5.95) genotypes appeared to be associated with raised breast cancer risk, with significantly increased risks observed in those with > or = 4 low-risk alleles compared with participants with < or = 2 low-risk alleles (OR = 1.77, 95% CI = 1.05-2.99, P-interaction = 0.006). Our results support the hypothesis that there are joint effects of endogenous and exogenous antioxidants.

  12. Mitochondrial nitric oxide synthase regulates mitochondrial matrix pH.

    PubMed

    Ghafourifar, P; Richter, C

    1999-01-01

    Nitric oxide (nitrogen monoxide, NO) exerts a wide profile of its biological activities via regulation of respiration and respiration-dependent functions. The presence of nitric oxide synthase (NOS) in mitochondria (mtNOS) was recently reported by us (Ghafourifar and Richter, FEBS Lett. 418, 291-296, 1997) and others (Giulivi et al., J. Biol. Chem. 273, 11038-11043, 1998). Here we report that NO, provided by an NO donor as well as by mtNOS stimulation, regulates mitochondrial matrix pH, transmembrane potential and Ca2+ buffering capacity. Exogenously-added NO causes a dose-dependent matrix acidification. Also mtNOS stimulation, induced by loading mitochondria with Ca2+, causes mitochondrial matrix acidification and a drop in mitochondrial transmembrane potential. Inhibition of mtNOS's basal activity causes mitochondrial matrix alkalinization and provides a resistance to the sudden drop of mitochondrial transmembrane potential induced by mitochondrial Ca2+ uptake. We conclude that mtNOS plays a critical role in regulating mitochondrial delta(pH).

  13. Contribution of mitochondrial oxidative stress to hypertension

    PubMed Central

    Dikalov, Sergey I.; Dikalova, Anna E.

    2016-01-01

    Purpose of review In 1954 Harman proposed the free radical theory of aging, and in 1972 he suggested that mitochondria are both the source and the victim of toxic free radicals. Interestingly, hypertension is age-associated disease and clinical data show that by age 70, 70% of the population has hypertension and this is accompanied by oxidative stress. Antioxidant therapy however is not currently available and common antioxidants like ascorbate and vitamin E are ineffective in preventing hypertension. The present review focuses on molecular mechanisms of mitochondrial oxidative stress and therapeutic potential of targeting mitochondria in hypertension. Recent findings In the past several years, we have shown that the mitochondria become dysfunctional in hypertension and have defined novel role of mitochondrial superoxide radicals in this disease. We have shown that genetic manipulation of mitochondrial antioxidant enzyme superoxide dismutase (SOD2) affects blood pressure and have developed mitochondria-targeted therapies such as SOD2 mimetics that effectively lower blood pressure. The specific mechanism of mitochondrial oxidative stress in hypertension, however, remains unclear. Recent animal and clinical studies have demonstrated several hormonal, metabolic, inflammatory, and environmental pathways contributing to mitochondrial dysfunction and oxidative stress. Summary Nutritional supplements, calorie restriction, and life style change are the most effective preventive strategies to improve mitochondrial function and reduce mitochondrial oxidative stress. Aging associated mitochondrial dysfunction, however, reduces efficacy of these strategies. Therefore, we propose that new classes of mitochondria-targeted antioxidants can provide high therapeutic potential to improve endothelial function and reduce hypertension. PMID:26717313

  14. The effect of disulphides on mitochondrial oxidations

    PubMed Central

    Skrede, S.; Bremer, J.; Eldjarn, L.

    1965-01-01

    1. Nicotinamide nucleotide-linked mitochondrial oxidations were inhibited by the disulphides NNN′N′-tetraethylcystamine, cystamine and cystine diethyl ester, whereas l-homocystine, oxidized mercaptoethanol, oxidized glutathione, NN′-diacetylcystamine and tetrathionate were only slightly inhibitory. Mitochondrial oxidations were not blocked by the thiol cysteamine. 2. NAD-independent oxidations were not inhibited by cystamine. The oxidation of choline was initially stimulated. 3. The inactivation of isocitrate, malate and β-hydroxybutyrate oxidation of intact mitochondria could be partially reversed by external NAD. For the reactivation of α-oxoglutarate oxidation a thiol was also required. 4. A leakage of nicotinamide nucleotides from the mitochondria is suggested as the main cause of the inhibition. In addition, a strong inhibition of α-oxoglutarate dehydrogenase by cystamine was observed. A mixed disulphide formation with CoA and possibly also lipoic acid and lipoyl dehydrogenase is suggested to explain this inhibition. PMID:14342523

  15. Piracetam improves mitochondrial dysfunction following oxidative stress

    PubMed Central

    Keil, Uta; Scherping, Isabel; Hauptmann, Susanne; Schuessel, Katin; Eckert, Anne; Müller, Walter E

    2005-01-01

    Mitochondrial dysfunction including decrease of mitochondrial membrane potential and reduced ATP production represents a common final pathway of many conditions associated with oxidative stress, for example, hypoxia, hypoglycemia, and aging. Since the cognition-improving effects of the standard nootropic piracetam are usually more pronounced under such pathological conditions and young healthy animals usually benefit little by piracetam, the effect of piracetam on mitochondrial dysfunction following oxidative stress was investigated using PC12 cells and dissociated brain cells of animals treated with piracetam. Piracetam treatment at concentrations between 100 and 1000 μM improved mitochondrial membrane potential and ATP production of PC12 cells following oxidative stress induced by sodium nitroprusside (SNP) and serum deprivation. Under conditions of mild serum deprivation, piracetam (500 μM) induced a nearly complete recovery of mitochondrial membrane potential and ATP levels. Piracetam also reduced caspase 9 activity after SNP treatment. Piracetam treatment (100–500 mg kg−1 daily) of mice was also associated with improved mitochondrial function in dissociated brain cells. Significant improvement was mainly seen in aged animals and only less in young animals. Moreover, the same treatment reduced antioxidant enzyme activities (superoxide dismutase, glutathione peroxidase, and glutathione reductase) in aged mouse brain only, which are elevated as an adaptive response to the increased oxidative stress with aging. In conclusion, therapeutically relevant in vitro and in vivo concentrations of piracetam are able to improve mitochondrial dysfunction associated with oxidative stress and/or aging. Mitochondrial stabilization and protection might be an important mechanism to explain many of piracetam's beneficial effects in elderly patients. PMID:16284628

  16. Piracetam improves mitochondrial dysfunction following oxidative stress.

    PubMed

    Keil, Uta; Scherping, Isabel; Hauptmann, Susanne; Schuessel, Katin; Eckert, Anne; Müller, Walter E

    2006-01-01

    1.--Mitochondrial dysfunction including decrease of mitochondrial membrane potential and reduced ATP production represents a common final pathway of many conditions associated with oxidative stress, for example, hypoxia, hypoglycemia, and aging. 2.--Since the cognition-improving effects of the standard nootropic piracetam are usually more pronounced under such pathological conditions and young healthy animals usually benefit little by piracetam, the effect of piracetam on mitochondrial dysfunction following oxidative stress was investigated using PC12 cells and dissociated brain cells of animals treated with piracetam. 3.--Piracetam treatment at concentrations between 100 and 1000 microM improved mitochondrial membrane potential and ATP production of PC12 cells following oxidative stress induced by sodium nitroprusside (SNP) and serum deprivation. Under conditions of mild serum deprivation, piracetam (500 microM) induced a nearly complete recovery of mitochondrial membrane potential and ATP levels. Piracetam also reduced caspase 9 activity after SNP treatment. 4.--Piracetam treatment (100-500 mg kg(-1) daily) of mice was also associated with improved mitochondrial function in dissociated brain cells. Significant improvement was mainly seen in aged animals and only less in young animals. Moreover, the same treatment reduced antioxidant enzyme activities (superoxide dismutase, glutathione peroxidase, and glutathione reductase) in aged mouse brain only, which are elevated as an adaptive response to the increased oxidative stress with aging. 5.--In conclusion, therapeutically relevant in vitro and in vivo concentrations of piracetam are able to improve mitochondrial dysfunction associated with oxidative stress and/or aging. Mitochondrial stabilization and protection might be an important mechanism to explain many of piracetam's beneficial effects in elderly patients.

  17. Effect of carvedilol and nebivolol on oxidative stress-related parameters and endothelial function in patients with essential hypertension.

    PubMed

    Zepeda, Ramiro J; Castillo, Rodrigo; Rodrigo, Ramón; Prieto, Juan C; Aramburu, Ivonne; Brugere, Solange; Galdames, Katia; Noriega, Viviana; Miranda, Hugo F

    2012-11-01

    Oxidative stress and endothelial dysfunction have been associated with essential hypertension (EH) mechanisms. The purpose of this study was to evaluate the effect of carvedilol and nebivolol on the oxidative stress-related parameters and endothelial function in patients with EH. The studied population included 57 patients, either sex, between 30 and 75 years of age, with mild-to-moderate EH complications. Participants were randomized to receive either carvedilol (12.5 mg) (n = 23) or nebivolol (5 mg) (n = 21) for 12 weeks. Measurements included; 24-hr ambulatory blood pressure (BP), flow-mediated dilatation, levels of nitric oxide estimated as nitrite - a nitric oxide metabolite ( NO₂) - in plasma, and oxidative stress-related parameters in plasma and erythrocyte. EH patients who were treated with nebivolol or carvedilol showed systolic BP reductions of 17.4 and 19.9 mmHg, respectively, compared with baseline values (p < 0.01). Diastolic BP was reduced by 13.7 and 12.8 mmHg after the treatment with ebivolol and carvedilol, respectively (p < 0.01) (fig. 2B). Nebivolol and carvedilol showed 7.3% and 8.1% higher endothelium-dependent dilatation in relation to baseline values (p < 0.05). Ferric-reducing ability of plasma (FRAP) and reduced glutathione/oxidized glutathione (GSSH) ratio showed 31.5% and 29.6% higher levels in the carvedilol group compared with basal values; however, nebivolol-treated patients did not show significant differences after treatment. On the other hand, the NO₂ plasma concentration was not modified by the administration of carvedilol. However, nebivolol enhanced these levels in 62.1% after the treatment. In conclusion, this study demonstrated the antihypertensive effect of both beta-blockers. However, carvedilol could mediate these effects by an increase in antioxidant capacity and nebivolol through the raise in NO₂ concentration. Further studies are needed to determine the molecular mechanism of these effects.

  18. Profiles of oxidative stress-related microRNA and mRNA expression in auditory cells.

    PubMed

    Wang, Zhi; Liu, Yimin; Han, Ning; Chen, Xuemei; Yu, Wei; Zhang, Weisen; Zou, Fei

    2010-07-30

    Oxidative stress and high levels of reactive oxygen species (ROS) are risk factors of auditory cell injury and hearing impairment. MicroRNAs (miRNAs) are critical for the post-transcriptional regulation of gene expression and cell proliferation and survival. However, little is known about the impact of oxidative stress on the expression of miRNAs and their targeted mRNAs in auditory cells. We employed a cell model of oxidative stress by treatment of House Ear Institute-Organ of Corti 1 (HEI-OC1) cells with different concentrations of tert-butyl hydroperoxide (t-BHP) to examine the t-BHP-induced production of ROS and to determine the impact of t-BHP treatment on the relative levels of miRNA and mRNA transcripts in HEI-OC1 cells. We found that treatment with different concentrations of t-BHP promoted the production of ROS, but inhibited the proliferation of HEI-OC1 cells in a dose- and time-dependent manner. Furthermore, treatment with t-BHP induced HEI-OC1 cell apoptosis. Further microarray analyses revealed that treatment with t-BHP increased the transcription of 35 miRNAs, but decreased the expression of 40 miRNAs. In addition, treatment with t-BHP up-regulated the transcription of 2076 mRNAs, but down-regulated the levels of 580 mRNA transcripts. Notably, the up-regulated (or down-regulated) miRNAs were associated with the decreased (or increased) expression of predicted targeted mRNAs. Importantly, these differentially expressed mRNAs belonged to different functional categories, forming a network participating in the oxidative stress-related process in HEI-OC1 cells. Therefore, our findings may provide new insights into understanding the regulation of miRNAs on the oxidative stress-related gene expression and function in auditory cells.

  19. Therapeutic Strategies for Oxidative Stress-Related Cardiovascular Diseases: Removal of Excess Reactive Oxygen Species in Adult Stem Cells.

    PubMed

    Kim, Hyunyun; Yun, Jisoo; Kwon, Sang-Mo

    Accumulating evidence indicates that acute and chronic uncontrolled overproduction of oxidative stress-related factors including reactive oxygen species (ROS) causes cardiovascular diseases (CVDs), atherosclerosis, and diabetes. Moreover ROS mediate various signaling pathways underlying vascular inflammation in ischemic tissues. With respect to stem cell-based therapy, several studies clearly indicate that modulating antioxidant production at cellular levels enhances stem/progenitor cell functionalities, including proliferation, long-term survival in ischemic tissues, and complete differentiation of transplanted cells into mature vascular cells. Recently emerging therapeutic strategies involving adult stem cells, including endothelial progenitor cells (EPCs), for treating ischemic CVDs have highlighted the need to control intracellular ROS production, because it critically affects the replicative senescence of ex vivo expanded therapeutic cells. Better understanding of the complexity of cellular ROS in stem cell biology might improve cell survival in ischemic tissues and enhance the regenerative potentials of transplanted stem/progenitor cells. In this review, we will discuss the nature and sources of ROS, drug-based therapeutic strategies for scavenging ROS, and EPC based therapeutic strategies for treating oxidative stress-related CVDs. Furthermore, we will discuss whether primed EPCs pretreated with natural ROS-scavenging compounds are crucial and promising therapeutic strategies for vascular repair.

  20. Therapeutic Strategies for Oxidative Stress-Related Cardiovascular Diseases: Removal of Excess Reactive Oxygen Species in Adult Stem Cells

    PubMed Central

    Yun, Jisoo

    2016-01-01

    Accumulating evidence indicates that acute and chronic uncontrolled overproduction of oxidative stress-related factors including reactive oxygen species (ROS) causes cardiovascular diseases (CVDs), atherosclerosis, and diabetes. Moreover ROS mediate various signaling pathways underlying vascular inflammation in ischemic tissues. With respect to stem cell-based therapy, several studies clearly indicate that modulating antioxidant production at cellular levels enhances stem/progenitor cell functionalities, including proliferation, long-term survival in ischemic tissues, and complete differentiation of transplanted cells into mature vascular cells. Recently emerging therapeutic strategies involving adult stem cells, including endothelial progenitor cells (EPCs), for treating ischemic CVDs have highlighted the need to control intracellular ROS production, because it critically affects the replicative senescence of ex vivo expanded therapeutic cells. Better understanding of the complexity of cellular ROS in stem cell biology might improve cell survival in ischemic tissues and enhance the regenerative potentials of transplanted stem/progenitor cells. In this review, we will discuss the nature and sources of ROS, drug-based therapeutic strategies for scavenging ROS, and EPC based therapeutic strategies for treating oxidative stress-related CVDs. Furthermore, we will discuss whether primed EPCs pretreated with natural ROS-scavenging compounds are crucial and promising therapeutic strategies for vascular repair. PMID:27668035

  1. Ageing, oxidative stress, and mitochondrial uncoupling.

    PubMed

    Harper, M-E; Bevilacqua, L; Hagopian, K; Weindruch, R; Ramsey, J J

    2004-12-01

    Mitochondria are a cell's single greatest source of reactive oxygen species. Reactive oxygen species are important for many life sustaining processes of cells and tissues, but they can also induce cell damage and death. If their production and levels within cells is not effectively controlled, then the detrimental effects of oxidative stress can accumulate. Oxidative stress is widely thought to underpin many ageing processes, and the oxidative stress theory of ageing is one of the most widely acknowledged theories of ageing. As well as being the major source of reactive oxygen species, mitochondria are also a major site of oxidative damage. The purpose of this review is a concise and current review of the effects of oxidative stress and ageing on mitochondrial function. Emphasis is placed upon the roles of mitochondrial proton leak, the uncoupling proteins, and the anti-ageing effects of caloric restriction.

  2. The Role of Na/K-ATPase Signaling in Oxidative Stress Related to Obesity and Cardiovascular Disease.

    PubMed

    Srikanthan, Krithika; Shapiro, Joseph I; Sodhi, Komal

    2016-09-03

    Na/K-ATPase has been extensively studied for its ion pumping function, but, in the past several decades, has been identified as a scaffolding and signaling protein. Initially it was found that cardiotonic steroids (CTS) mediate signal transduction through the Na/K-ATPase and result in the generation of reactive oxygen species (ROS), which are also capable of initiating the signal cascade. However, in recent years, this Na/K-ATPase/ROS amplification loop has demonstrated significance in oxidative stress related disease states, including obesity, atherosclerosis, heart failure, uremic cardiomyopathy, and hypertension. The discovery of this novel oxidative stress signaling pathway, holds significant therapeutic potential for the aforementioned conditions and others that are rooted in ROS.

  3. Nickel inhibits mitochondrial fatty acid oxidation.

    PubMed

    Uppala, Radha; McKinney, Richard W; Brant, Kelly A; Fabisiak, James P; Goetzman, Eric S

    2015-08-07

    Nickel exposure is associated with changes in cellular energy metabolism which may contribute to its carcinogenic properties. Here, we demonstrate that nickel strongly represses mitochondrial fatty acid oxidation-the pathway by which fatty acids are catabolized for energy-in both primary human lung fibroblasts and mouse embryonic fibroblasts. At the concentrations used, nickel suppresses fatty acid oxidation without globally suppressing mitochondrial function as evidenced by increased glucose oxidation to CO2. Pre-treatment with l-carnitine, previously shown to prevent nickel-induced mitochondrial dysfunction in neuroblastoma cells, did not prevent the inhibition of fatty acid oxidation. The effect of nickel on fatty acid oxidation occurred only with prolonged exposure (>5 h), suggesting that direct inhibition of the active sites of metabolic enzymes is not the mechanism of action. Nickel is a known hypoxia-mimetic that activates hypoxia inducible factor-1α (HIF1α). Nickel-induced inhibition of fatty acid oxidation was blunted in HIF1α knockout fibroblasts, implicating HIF1α as one contributor to the mechanism. Additionally, nickel down-regulated the protein levels of the key fatty acid oxidation enzyme very long-chain acyl-CoA dehydrogenase (VLCAD) in a dose-dependent fashion. In conclusion, inhibition of fatty acid oxidation by nickel, concurrent with increased glucose metabolism, represents a form of metabolic reprogramming that may contribute to nickel-induced carcinogenesis.

  4. Oxidative stress-related mechanisms affecting response to aspirin in diabetes mellitus.

    PubMed

    Santilli, Francesca; Lapenna, Domenico; La Barba, Sara; Davì, Giovanni

    2015-03-01

    Type 2 diabetes mellitus (T2DM) is a major cardiovascular risk factor. Persistent platelet activation plays a key role in atherothrombosis in T2DM. However, current antiplatelet treatments appear less effective in T2DM patients vs nondiabetics at similar risk. A large body of evidence supports the contention that oxidative stress, which characterizes DM, may be responsible, at least in part, for less-than-expected response to aspirin, with multiple mechanisms acting at several levels. This review discusses the pathophysiological mechanisms related to oxidative stress and contributing to suboptimal aspirin action or responsiveness. These include: (1) mechanisms counteracting the antiplatelet effect of aspirin, such as reduced platelet sensitivity to the antiaggregating effects of NO, due to high-glucose-mediated oxidative stress; (2) mechanisms interfering with COX acetylation especially at the platelet level, e.g., lipid hydroperoxide-dependent impaired acetylating effects of aspirin; (3) mechanisms favoring platelet priming (lipid hydroperoxides) or activation (F2-isoprostanes, acting as partial agonists of thromboxane receptor), or aldose-reductase pathway-mediated oxidative stress, leading to enhanced platelet thromboxane A2 generation or thromboxane receptor activation; (4) mechanisms favoring platelet recruitment, such as aspirin-induced platelet isoprostane formation; (5) modulation of megakaryocyte generation and thrombopoiesis by oxidative HO-1 inhibition; and (6) aspirin-iron interactions, eventually resulting in impaired pharmacological activity of aspirin, lipoperoxide burden, and enhanced generation of hydroxyl radicals capable of promoting protein kinase C activation and platelet aggregation. Acknowledgment of oxidative stress as a major contributor, not only of vascular complications, but also of suboptimal response to antiplatelet agents in T2DM, may open the way to designing and testing novel antithrombotic strategies, specifically targeting

  5. Nickel Inhibits Mitochondrial Fatty Acid Oxidation

    PubMed Central

    Uppala, Radha; McKinney, Richard W.; Brant, Kelly A.; Fabisiak, James P.; Goetzman, Eric S.

    2015-01-01

    Nickel exposure is associated with changes in cellular energy metabolism which may contribute to its carcinogenic properties. Here, we demonstrate that nickel strongly represses mitochondrial fatty acid oxidation—the pathway by which fatty acids are catabolized for energy—in both primary human lung fibroblasts and mouse embryonic fibroblasts. At the concentrations used, nickel suppresses fatty acid oxidation without globally suppressing mitochondrial function as evidenced by increased glucose oxidation to CO2. Pre-treatment with L-carnitine, previously shown to prevent nickel-induced mitochondrial dysfunction in neuroblastoma cells, did not prevent the inhibition of fatty acid oxidation. The effect of nickel on fatty acid oxidation occurred only with prolonged exposure (>5 hr), suggesting that direct inhibition of the active sites of metabolic enzymes is not the mechanism of action. Nickel is a known hypoxia-mimetic that activates hypoxia inducible factor-1α (HIF1α). Nickel-induced inhibition of fatty acid oxidation was blunted in HIF1α knockout fibroblasts, implicating HIF1α as one contributor to the mechanism. Additionally, nickel down-regulated the protein levels of the key fatty acid oxidation enzyme very long-chain acyl-CoA dehydrogenase (VLCAD) in a dose-dependent fashion. In conclusion, inhibition of fatty acid oxidation by nickel, concurrent with increased glucose metabolism, represents a form of metabolic reprogramming that may contribute to nickel-induced carcinogenesis. PMID:26051273

  6. Impaired cardiac mitochondrial oxidative phosphorylation and enhanced mitochondrial oxidative stress in feline hypertrophic cardiomyopathy.

    PubMed

    Christiansen, Liselotte B; Dela, Flemming; Koch, Jørgen; Hansen, Christina N; Leifsson, Pall S; Yokota, Takashi

    2015-05-15

    Mitochondrial dysfunction and oxidative stress are important players in the development of various cardiovascular diseases, but their roles in hypertrophic cardiomyopathy (HCM) remain unknown. We examined whether mitochondrial oxidative phosphorylation (OXPHOS) capacity was impaired with enhanced mitochondrial oxidative stress in HCM. Cardiac and skeletal muscles were obtained from 9 domestic cats with spontaneously occurring HCM with preserved left ventricular systolic function and from 15 age-matched control cats. Mitochondrial OXPHOS capacities with nonfatty acid and fatty acid substrates in permeabilized fibers and isolated mitochondria were assessed using high-resolution respirometry. ROS release originating from isolated mitochondria was assessed by spectrofluorometry. Thiobarbituric acid-reactive substances were also measured as a marker of oxidative damage. Mitochondrial ADP-stimulated state 3 respiration with complex I-linked nonfatty acid substrates and with fatty acid substrates, respectively, was significantly lower in the hearts of HCM cats compared with control cats. Mitochondrial ROS release during state 3 with complex I-linked substrates and thiobarbituric acid-reactive substances in the heart were significantly increased in cats with HCM. In contrast, there were no significant differences in mitochondrial OXPHOS capacity, mitochondrial ROS release, and oxidative damage in skeletal muscle between groups. Mitochondrial OXPHOS capacity with both nonfatty acid substrates and fatty acid substrates was impaired with increased mitochondrial ROS release in the feline HCM heart. These findings provide new insights into the pathophysiology of HCM and support the hypothesis that restoration of the redox state in the mitochondria is beneficial in the treatment of HCM. Copyright © 2015 the American Physiological Society.

  7. Oxidative stress-related liver dysfunction by sodium arsenite: Alleviation by Pistacia lentiscus oil.

    PubMed

    Klibet, Fahima; Boumendjel, Amel; Khiari, Mohamed; El Feki, Abdelfattah; Abdennour, Cherif; Messarah, Mahfoud

    2016-01-01

    Pistacia lentiscus L. (Anacardiaceae) is an evergreen shrub widely distributed throughout the Mediterranean region. Pistacia lentiscus oil (PLo) was particularly known in North African traditional medicine. Thus, people of these regions have used it externally to treat sore throats, burns and wounds, as well as they employed it internally for respiratory allergies. PLo is rich in essential fatty acids, vitamin E and polyphenols. As a very active site of metabolism, liver is reported to be susceptible to arsenic (As) intoxication. The present study evaluates the protective effect of PLo against sodium arsenite-induced hepatic dysfunction and oxidative stress in experimental Wistar rats. Twenty-eight rats were equally divided into four groups; the first served as a control, the remaining groups were respectively treated with PLo (3.3 mL/kg body weight), sodium arsenite (5.55 mg/kg body weight) and a combination of sodium arsenite and PLo. After 21 consecutive days, cellular functions were evaluated by hematological, biochemical and oxidative stress markers. A significant decrease in the levels of red blood cells, haemoglobin (p ≤ 0.001), hematocrit (p ≤ 0.001), reduced glutathione and metallothionein (p ≤ 0.05) associated with a significant increase of malondialdehyde (p ≤ 0.001) were noticed in the arsenic-exposed group when compared to the control. The As-treated group also exhibited an increase in hepatic antioxidant enzymes namely superoxide dismutase, glutathione peroxidase (p ≤ 0.01) and catalase (p ≤ 0.05). However, the co-administration of PLo has relatively reduced arsenic effect. The results showed that arsenic intoxication disturbed the liver pro-oxidant/antioxidant status. PLo co-administration mitigates arsenic-induced oxidative damage in rat.

  8. Neuroendocrine Profile in a Rat Model of Psychosocial Stress: Relation to Oxidative Stress

    PubMed Central

    Colaianna, Marilena; Schiavone, Stefania; Zotti, Margherita; Tucci, Paolo; Morgese, Maria Grazia; Bäckdahl, Liselotte; Holmdahl, Rikard; Krause, Karl-Heinz; Cuomo, Vincenzo

    2013-01-01

    Abstract Aims: Psychosocial stress alters the hypothalamic-pituitary-adrenal axis (HPA-axis). Increasing evidence shows a link between these alterations and oxidant elevation. Oxidative stress is implicated in the stress response and in the pathogenesis of neurologic and psychiatric diseases. NADPH oxidases (NOXs) are a major source of reactive oxygen species (ROS) in the central nervous system. Here, we investigated the contributory role of NOX2-derived ROS to the development of neuroendocrine alterations in a rat model of chronic psychosocial stress, the social isolation. Results: Significant elevations in the hypothalamic levels of corticotropin-releasing factor and plasmatic adrenocorticotropic hormone were observed from 4 weeks of social isolation. Increased levels of peripheral markers of the HPA-axis (plasmatic and salivary corticosterone) were observed at a later time point of social isolation (7 weeks). Alteration in the exploratory activity of isolated rats followed the same time course. Increased expression of markers of oxidative stress (8-hydroxy-2-deoxyguanosine [8OhdG] and nitrotyrosine) and NOX2 mRNA was early detectable in the hypothalamus of isolated rats (after 2 weeks), but later (after 7 weeks) in the adrenal gland. A 3-week treatment with the antioxidant/NOX inhibitor apocynin stopped the progression of isolation-induced alterations of the HPA-axis. Rats with a loss-of-function mutation in the NOX2 subunit p47phox were totally protected from the alterations of the neuroendocrine profile, behavior, and increased NOX2 mRNA expression induced by social isolation. Innovation: We demonstrate that psychosocial stress induces early elevation of NOX2-derived oxidative stress in the hypothalamus and consequent alterations of the HPA-axis, leading ultimately to an altered behavior. Conclusion: Pharmacological targeting of NOX2 might be of crucial importance for the treatment of psychosocial stress-induced psychosis. Antioxid. Redox Signal. 18, 1385

  9. Oxidative Stress-Related Biomarkers in Postmenopausal Osteoporosis: A Systematic Review and Meta-Analyses

    PubMed Central

    Zhou, Qiaozhen; Zhu, Li; Zhang, Dafeng; Li, Ning; Li, Qiao; Dai, Panpan; Mao, Yixin; Li, Xumin

    2016-01-01

    Numerous studies suggested that oxidative stress (OS) played a central role in the onset and development of postmenopausal osteoporosis (PO); however, conflicting results were obtained as to the association of OS-related biomarkers and PO. This meta-analysis aimed to identify the association between these markers and PO, and explore factors that may explain the inconsistencies in these results. A systematic literature search was conducted in relevant database. Search terms and selection criteria were priorly determined to identify and include all studies that detected markers of OS in PO patients. We pooled data with a random effects meta-analysis with standardized mean differences and 95% confidence interval. Total 17 studies including 12 OS markers were adopted. The results showed that superoxide dismutase (SOD) in erythrocytes, catalase (CAT), total antioxidant status (TAS), hydroperoxides (HY), advanced oxidation protein products (AOPP), malondialdehyde (MDA), and vitamin B12 (VB12) in plasma/serum were not statistically different between the PO and control group, whereas significantly increased level of homocysteine (Hcy) and nitric oxide (NO), along with decreased SOD, glutathione peroxidase (GPx), folate, and total antioxidant power (TAP) in plasma/serum were obtained in the PO group. In summary, OS might serve as potential biomarkers in the etiopathophysiology and clinical course of PO. PMID:27594735

  10. Oxidative Stress-Related Biomarkers in Postmenopausal Osteoporosis: A Systematic Review and Meta-Analyses.

    PubMed

    Zhou, Qiaozhen; Zhu, Li; Zhang, Dafeng; Li, Ning; Li, Qiao; Dai, Panpan; Mao, Yixin; Li, Xumin; Ma, Jianfeng; Huang, Shengbin

    2016-01-01

    Numerous studies suggested that oxidative stress (OS) played a central role in the onset and development of postmenopausal osteoporosis (PO); however, conflicting results were obtained as to the association of OS-related biomarkers and PO. This meta-analysis aimed to identify the association between these markers and PO, and explore factors that may explain the inconsistencies in these results. A systematic literature search was conducted in relevant database. Search terms and selection criteria were priorly determined to identify and include all studies that detected markers of OS in PO patients. We pooled data with a random effects meta-analysis with standardized mean differences and 95% confidence interval. Total 17 studies including 12 OS markers were adopted. The results showed that superoxide dismutase (SOD) in erythrocytes, catalase (CAT), total antioxidant status (TAS), hydroperoxides (HY), advanced oxidation protein products (AOPP), malondialdehyde (MDA), and vitamin B12 (VB12) in plasma/serum were not statistically different between the PO and control group, whereas significantly increased level of homocysteine (Hcy) and nitric oxide (NO), along with decreased SOD, glutathione peroxidase (GPx), folate, and total antioxidant power (TAP) in plasma/serum were obtained in the PO group. In summary, OS might serve as potential biomarkers in the etiopathophysiology and clinical course of PO.

  11. Antioxidant and oxidative stress related responses in the Mediterranean land snail Cantareus apertus exposed to the carbamate pesticide Carbaryl.

    PubMed

    Leomanni, A; Schettino, T; Calisi, A; Gorbi, S; Mezzelani, M; Regoli, F; Lionetto, M G

    2015-02-01

    The aim of the present work was to study the alterations of the antioxidant defenses and the overall susceptibility to oxidative stress of the terrestrial snail Cantareus apertus exposed to the carbamate pesticide Carbaryl at a low environmentally realistic concentration. The animals were exposed to Lactuca sativa soaked for 1h in 1μM Carbaryl. The temporal dynamics of the responses was assessed by measurements at 3, 7 and 14days of exposure. C. apertus exposed to Carbaryl activates a number of enzymatic antioxidant responses, represented by the early induction of catalase, glutathione peroxidase, glutathione reductase, followed by a delayed induction of superoxide dismutase. Concomitantly, a derangement of the total oxyradical scavenging of the tissues was observed, suggesting an overall impairment of the tissue capability to neutralize ROS probably resulting from the overall negative balance between enzymatic antioxidant defense capability and oxidative stress intensity. This negative balance exposed the animals to the risk of oxidative stress damages including genotoxic damage. Compared to acetylcholinesterase inhibition, the antioxidant responses developed to Carbaryl exposure at the low concentration utilized showed a greater percentage variation in exposed organisms. The results pointed out the high sensitivity of the antioxidant and oxidative stress related responses to Carbaryl exposure at an environmental realistic concentration, demonstrating their usefulness in environmental monitoring and risk assessment. The study highlights also the usefulness of the terrestrial snail C. apertus as potential bioindicator species for assessing the risk of pesticide environmental contamination.

  12. BGP-15 Protects against Oxidative Stress- or Lipopolysaccharide-Induced Mitochondrial Destabilization and Reduces Mitochondrial Production of Reactive Oxygen Species

    PubMed Central

    Sumegi, Katalin; Fekete, Katalin; Antus, Csenge; Debreceni, Balazs; Hocsak, Eniko; Gallyas, Ferenc; Sumegi, Balazs; Szabo, Aliz

    2017-01-01

    Reactive oxygen species (ROS) play a critical role in the progression of mitochondria-related diseases. A novel insulin sensitizer drug candidate, BGP-15, has been shown to have protective effects in several oxidative stress-related diseases in animal and human studies. In this study, we investigated whether the protective effects of BGP-15 are predominantly via preserving mitochondrial integrity and reducing mitochondrial ROS production. BGP-15 was found to accumulate in the mitochondria, protect against ROS-induced mitochondrial depolarization and attenuate ROS-induced mitochondrial ROS production in a cell culture model, and also reduced ROS production predominantly at the complex I-III system in isolated mitochondria. At physiologically relevant concentrations, BGP-15 protected against hydrogen peroxide-induced cell death by reducing both apoptosis and necrosis. Additionally, it attenuated bacterial lipopolysaccharide (LPS)-induced collapse of mitochondrial membrane potential and ROS production in LPS-sensitive U-251 glioma cells, suggesting that BGP-15 may have a protective role in inflammatory diseases. However, BGP-15 did not have any antioxidant effects as shown by in vitro chemical and cell culture systems. These data suggest that BGP-15 could be a novel mitochondrial drug candidate for the prevention of ROS-related and inflammatory disease progression. PMID:28046125

  13. BGP-15 Protects against Oxidative Stress- or Lipopolysaccharide-Induced Mitochondrial Destabilization and Reduces Mitochondrial Production of Reactive Oxygen Species.

    PubMed

    Sumegi, Katalin; Fekete, Katalin; Antus, Csenge; Debreceni, Balazs; Hocsak, Eniko; Gallyas, Ferenc; Sumegi, Balazs; Szabo, Aliz

    2017-01-01

    Reactive oxygen species (ROS) play a critical role in the progression of mitochondria-related diseases. A novel insulin sensitizer drug candidate, BGP-15, has been shown to have protective effects in several oxidative stress-related diseases in animal and human studies. In this study, we investigated whether the protective effects of BGP-15 are predominantly via preserving mitochondrial integrity and reducing mitochondrial ROS production. BGP-15 was found to accumulate in the mitochondria, protect against ROS-induced mitochondrial depolarization and attenuate ROS-induced mitochondrial ROS production in a cell culture model, and also reduced ROS production predominantly at the complex I-III system in isolated mitochondria. At physiologically relevant concentrations, BGP-15 protected against hydrogen peroxide-induced cell death by reducing both apoptosis and necrosis. Additionally, it attenuated bacterial lipopolysaccharide (LPS)-induced collapse of mitochondrial membrane potential and ROS production in LPS-sensitive U-251 glioma cells, suggesting that BGP-15 may have a protective role in inflammatory diseases. However, BGP-15 did not have any antioxidant effects as shown by in vitro chemical and cell culture systems. These data suggest that BGP-15 could be a novel mitochondrial drug candidate for the prevention of ROS-related and inflammatory disease progression.

  14. Understanding and preventing mitochondrial oxidative damage

    PubMed Central

    Murphy, Michael P.

    2016-01-01

    Mitochondrial oxidative damage has long been known to contribute to damage in conditions such as ischaemia–reperfusion (IR) injury in heart attack. Over the past years, we have developed a series of mitochondria-targeted compounds designed to ameliorate or determine how this damage occurs. I will outline some of this work, from MitoQ to the mitochondria-targeted S-nitrosating agent, called MitoSNO, that we showed was effective in preventing reactive oxygen species (ROS) formation in IR injury with therapeutic implications. In addition, the protection by this compound suggested that ROS production in IR injury was mainly coming from complex I. This led us to investigate the mechanism of the ROS production and using a metabolomic approach, we found that the ROS production in IR injury came from the accumulation of succinate during ischaemia that then drove mitochondrial ROS production by reverse electron transport at complex I during reperfusion. This surprising mechanism led us to develop further new therapeutic approaches to have an impact on the damage that mitochondrial ROS do in pathology and also to explore how mitochondrial ROS can act as redox signals. I will discuss how these approaches have led to a better understanding of mitochondrial oxidative damage in pathology and also to the development of new therapeutic strategies. PMID:27911703

  15. Mechanisms of Mycotoxin-induced Dermal Toxicity and Tumorigenesis Through Oxidative Stress-related Pathways

    PubMed Central

    Doi, Kunio; Uetsuka, Koji

    2014-01-01

    Among the many mycotoxins, T-2 toxin, citrinin (CTN), patulin (PAT), aflatoxin B1 (AFB1) and ochratoxin A (OTA) are known to have the potential to induce dermal toxicity and/or tumorigenesis in rodent models. T-2 toxin, CTN, PAT and OTA induce apoptosis in mouse or rat skin. PAT, AFB1 and OTA have tumor initiating properties, and OTA is also a tumor promoter in mouse skin. This paper reviews the molecular mechanisms of dermal toxicity and tumorigenesis induced in rodent models by these mycotoxins especially from the viewpoint of oxidative stress-mediated pathways. PMID:24791061

  16. Novel quercetin derivatives: From redox properties to promising treatment of oxidative stress related diseases.

    PubMed

    Zizkova, Petronela; Stefek, Milan; Rackova, Lucia; Prnova, Marta; Horakova, Lubica

    2017-03-01

    A set of O-substituted quercetin derivatives was prepared with the aim to optimize bioavailability and redox properties of quercetin, a known agent with multiple health beneficial effects. Electron-acceptor/-donor properties of the agents were evaluated theoretically by quantum chemical calculations and by experimental methods in cell-free model systems (2,2-diphenyl-1-picrylhydrazyl (DPPH) test, the ferric reducing ability of plasma (FRAP), peroxynitrite scavenging, protein-thiol oxidation) and in cellular systems of fibroblasts, microglials and cancer lines. The order of individual antioxidant effects varied dependently on the system used. In cellular systems, quercetin derivatives were shown to be better antioxidants compared to quercetin. Monochloropivaloylquercetin (CPQ), monoacetylferuloylquercetin (MAFQ) and chloronaphthoquinonequercetin (CHNQ) showed a prominent inhibitory effect on the key enzymes involved in diabetic complications, aldose reductase and α-glucosidase, suggesting their promising therapeutic application. In the cellular models of BHNF-3 fibroblasts, microglial cell line BV-2, colorectal cancer cell lines HCT-116 and HT-29, CHNQ and CPQ were studied for their cytotoxic, antiproliferative and antiinflammatory properties. In the rat model, CHNQ attenuated colon inflammation induced by acetic acid. In summary, our studies revealed CPQ and CHNQ as potential remedies of chronic age-related metabolic or inflammatory diseases, including diabetes and neurodegenerations. Furthermore, CHNQ represents a novel promising agent exerting its anticancer effect through induction of oxidative stress-dependent cell death. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Oxidative stress-related mechanisms are associated with xenobiotics exerting excess toxicity to Fanconi anemia cells.

    PubMed Central

    Pagano, Giovanni; Manini, Paola; Bagchi, Debasis

    2003-01-01

    An extensive body of evidence has demonstrated the sensitivity of Fanconi anemia (FA) cells to redox-active xenobiotics, such as mitomycin C, diepoxybutane, cisplatin, and 8-methoxypsoralen plus ultraviolet irradiation, with toxicity mechanisms that are consistent with a deficiency of FA cells in coping with oxidative stress. A recent study has reported on excess sensitivity of FA complementation A group cells to chromium VI [Cr(VI)] toxicity, by postulating that a deficiency in Cr-DNA cross-link removal by FA cells and formation of Cr(VI)-associated cross-links may be the mechanism of Cr(VI)-induced cytotoxicity. However, the report failed to demonstrate any enhanced Cr uptake or, especially, any increase in Cr-DNA adducts. Thus, well-established findings on Cr(VI)-induced oxidative stress may explain excess sensitivity of FA cells to Cr(VI) in terms of its inability to cope with the Cr(VI)-induced prooxidant state. PMID:14594617

  18. Oxidative Stress, Mitochondrial Dysfunction, and Aging

    PubMed Central

    Cui, Hang; Kong, Yahui; Zhang, Hong

    2012-01-01

    Aging is an intricate phenomenon characterized by progressive decline in physiological functions and increase in mortality that is often accompanied by many pathological diseases. Although aging is almost universally conserved among all organisms, the underlying molecular mechanisms of aging remain largely elusive. Many theories of aging have been proposed, including the free-radical and mitochondrial theories of aging. Both theories speculate that cumulative damage to mitochondria and mitochondrial DNA (mtDNA) caused by reactive oxygen species (ROS) is one of the causes of aging. Oxidative damage affects replication and transcription of mtDNA and results in a decline in mitochondrial function which in turn leads to enhanced ROS production and further damage to mtDNA. In this paper, we will present the current understanding of the interplay between ROS and mitochondria and will discuss their potential impact on aging and age-related diseases. PMID:21977319

  19. Novel recombinant human lactoferrin: differential activation of oxidative stress related gene expression.

    PubMed

    Kruzel, Marian L; Actor, Jeffrey K; Zimecki, Michał; Wise, Jasen; Płoszaj, Paulina; Mirza, Shaper; Kruzel, Mark; Hwang, Shen-An; Ba, Xueqing; Boldogh, Istvan

    2013-12-01

    Lactoferrin, an iron-binding protein found in high concentrations in mammalian exocrine secretions, is an important component of the host defense system. It is also a major protein of the secondary granules of neutrophils from which is released upon activation. Due to its potential clinical utility, recombinant human lactoferrin (rhLF) has been produced in various eukaryotic expression systems; however, none of these are fully compatible with humans. Most of the biopharmaceuticals approved by the FDA for use in humans are produced in mammalian expression systems. The Chinese hamster ovary cells (CHO) have become the system of choice for proteins that require post-translational modifications, such as glycoproteins. The aim of this study was to scale-up expression and purification of rhLF in a CHO expression system, verify its glycan primary structure, and assess its biological properties in cell culture models. A stable CHO cell line producing >200mg/L of rhLF was developed and established. rhLF was purified by a single-step cation-exchange chromatography procedure. The highly homogenous rhLF has a molecular weight of approximately 80 kDa. MALDI-TOF mass spectrometric analysis revealed N-linked, partially sialylated glycans at two glycosylation sites, typical for human milk LF. This novel rhLF showed a protective effect against oxidative stress in a similar manner to its natural counterpart. In addition, rhLF revealed a modulatory effect on cellular redox via upregulation of key antioxidant enzymes. These data imply that the CHO-derived rhLF is fully compatible with the native molecule, thus it has promise for human therapeutic applications. Copyright © 2013 Elsevier B.V. All rights reserved.

  20. Vitamin E in oxidant stress-related cardiovascular pathologies: focus on experimental studies.

    PubMed

    Turan, Belma; Vassort, Guy

    2011-01-01

    The scope of this review is to summarize the important roles of vitamin E family members as protective agents in cardiovascular pathologies of different types of disease states and particularly in diabetes, including some of our research results, to illustrate how this recent knowledge is helping to better understand the roles of the vitamin E family in biology, in animals and humans specifically. Cardiovascular disease, a general name for a wide variety of diseases, disorders and conditions, is caused by disorders of the heart and blood vessels. Cardiovascular disease is the world's largest killer, claiming 17.1 million lives a year. Cardiovascular complications result from multiple parameters including glucotoxicity, lipotoxicity, fibrosis. Obesity and diabetes mellitus are also often linked to cardiovascular disease. In fact, cardiovascular disease is the most life-threatening of the diabetic complications and diabetics are 2- to 4-fold more likely to die of cardiovascular-related causes than non-diabetics. In order to prevent the tendency of cardiovascular disease, primary prevention is needed by modifying risk factors. Several recent studies, besides earlier ones, have reported beneficial effects of therapy with antioxidant agents, including trace elements, vitamins (E and/or C), other antioxidants, against the cardiovascular dysfunction. Hence, the use of peroxisome proliferator activated receptor-α (PPARα) agonists to reduce fatty acid oxidation, of trace elements such as selenium as antioxidant and other antioxidants such as vitamins E and C, contributes to the prevention of these dysfunctions. Moreover, therapy with antioxidants and the above vitamins to prevent or delay the onset and development of cardiovascular complications in diabetic patients and animal models has been investigated although these studies showed inconsistent results.

  1. Protective effects of selenium on oxidative damage and oxidative stress related gene expression in rat liver under chronic poisoning of arsenic.

    PubMed

    Xu, Zhao; Wang, Zhou; Li, Jian-jun; Chen, Chen; Zhang, Ping-chuan; Dong, Lu; Chen, Jing-hong; Chen, Qun; Zhang, Xiao-tian; Wang, Zhi-lun

    2013-08-01

    Arsenic (As) is a toxic metalloid existing widely in the environment, and chronic exposure to it through contaminated drinking water has become a global problem of public health. The present study focused on the protective effects of selenium on oxidative damage of chronic arsenic poisoning in rat liver. Rats were divided into four groups at random and given designed treatments for 20 weeks. The oxidative damage of liver tissue was evaluated by lipid peroxidation and antioxidant enzymes. Oxidative stress related genes were detected to reflect the liver stress state at the molecular level. Compared to the control and Na2SeO3 groups, the MDA content in liver tissue was decreased and the activities of antioxidant enzymes were increased in the Na2SeO3 intervention group. The mRNA levels of SOD1, CAT, GPx and Txnrd1 were increased significantly (P<0.05) in the combined Na2SeO3+NaAsO2 treatment group. The expressions of HSP70 and HO-1 were significantly (P<0.05) increased in the NaAsO2 group and reduced in the combined treatment group. The results indicate that long-term intake of NaAsO2 causes oxidative damage in the rat liver, and Na2SeO3 protects liver cells by adjusting the expression of oxidative stress related genes to improve the activities of antioxidant enzymes. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

  2. The leishmanicidal activity of oleuropein is selectively regulated through inflammation- and oxidative stress-related genes.

    PubMed

    Kyriazis, Ioannis D; Koutsoni, Olga S; Aligiannis, Nektarios; Karampetsou, Kalliopi; Skaltsounis, Alexios-Leandros; Dotsika, Eleni

    2016-08-09

    Much research effort has been focused on investigating new compounds derived from low-cost sources, such as natural products, for treating leishmaniasis. Oleuropein derived from numerous plants, particularly from the olive tree, Olea europaea L. (Oleaceae), is a biophenol with many biological activities. Our previous findings showed that oleuropein exhibits leishmanicidal effects against three Leishmania spp. in vitro, and minimizes the parasite burden in L. donovani-infected BALB/c mice. The aim of the present study is to investigate the possible mechanism(s) that mediate this leishmanicidal activity. We determined the efficacy of oleuropein in elevating ROS and NO production in L. donovani-infected J774A.1 macrophages and in explanted splenocytes and hepatocytes obtained from L. donovani-infected BALB/c mice. We also assessed the expression of genes that are related to inflammation, T-cell polarization and antioxidant defense, in splenocytes. Finally, we determined the ratios of specific IgG2a/IgG1 antibodies and DTH reactions in L. donovani-infected BALB/c mice treated with oleuropein. Oleuropein was able to elevate ROS production in both in vitro and in vivo models of visceral leishmaniasis and raised NO production in ex vivo cultures of splenocytes and hepatocytes. The extensive oxidative stress found in oleuropein-treated mice was obviated by the upregulation of the host's antioxidant enzyme (mGCLC) and the simultaneous downregulation of the corresponding enzyme of the parasite (LdGCLC). Moreover, oleuropein was able to mount a significant Th1 polarization characterized by the expression of immune genes (IL-12β, IL-10, TGF-β1, IFN-γ) and transcription factors (Tbx21 and GATA3). Moreover, this immunomodulatory effect was also correlated with an inhibitory effect on IL-1β gene expression, rather than with the expression of IL-1α, IL-1rn and TNF-α. Furthermore, oleuropein-treated BALB/c mice mounted a delayed-type hypersensitivity (DTH) response and an

  3. Role of mitochondrial oxidative stress in hypertension

    PubMed Central

    Ungvari, Zoltan

    2013-01-01

    Based on mosaic theory, hypertension is a multifactorial disorder that develops because of genetic, environmental, anatomical, adaptive neural, endocrine, humoral, and hemodynamic factors. It has been recently proposed that oxidative stress may contribute to all of these factors and production of reactive oxygen species (ROS) play an important role in the development of hypertension. Previous studies focusing on the role of vascular NADPH oxidases provided strong support of this concept. Although mitochondria represent one of the most significant sources of cellular ROS generation, the regulation of mitochondrial ROS generation in the cardiovascular system and its pathophysiological role in hypertension are much less understood. In this review, the role of mitochondrial oxidative stress in the pathophysiology of hypertension and cross talk between angiotensin II signaling, pathways involved in mechanotransduction, NADPH oxidases, and mitochondria-derived ROS are considered. The possible benefits of therapeutic strategies that have the potential to attenuate mitochondrial oxidative stress for the prevention/treatment of hypertension are also discussed. PMID:24043248

  4. Effects of hexaammine cobalt (III) chloride on oxidative stress-related parameters and drug metabolizing enzymes in mice.

    PubMed

    Singh, Amarjit; Kalla, Natwar R; Sharma, Raj P; Sharma, Rajeshwar

    2007-01-01

    Hexaammine cobalt (III) chloride has been advocated as a potential anticarcinogenic compound. There is no information on the effects of this compound on oxidative stress-related parameters in animals. In the present study the effects of administration of hexaammine cobalt (III) chloride in drinking water to balb/c male mice at doses of 25, 50, and 100 ppm for 14 weeks were examined. The tissue distribution of the compound was seen in liver, kidney, lung, intestine, blood, and spleen. The effects of the compound were monitored on levels of lipid peroxidation, GSH content, and activities of SOD, catalase, GST, and Cyt P450, along with the liver and kidney function tests. The results show that the cobalt accumulated maximally in kidney followed by liver, intestine, blood, spleen, and lung in decreasing order, in a dose-dependent manner. GSH and GST also showed increase in a dose-dependent manner while SOD and catalase showed increase with the highest dose only. Liver and kidney function tests showed no untoward change with any dose at the end of the study. The results suggest an antioxidant potentiating effect of the hexaammine cobalt (III) chloride besides nontoxicity to liver and kidney. Since the ability to induce an increase of GSH and GST along with other detoxifying enzymes by anticarcinogenic agents has been reported to correlate with the inhibition of tumorigenesis, the cobalt complex might qualify as a potential cancer chemopreventive agent.

  5. Oxidative stress and mitochondrial dysfunction in sepsis.

    PubMed

    Galley, H F

    2011-07-01

    Sepsis-related organ dysfunction remains the most common cause of death in the intensive care unit (ICU), despite advances in healthcare and science. Marked oxidative stress as a result of the inflammatory responses inherent with sepsis initiates changes in mitochondrial function which may result in organ damage. Normally, a complex system of interacting antioxidant defences is able to combat oxidative stress and prevents damage to mitochondria. Despite the accepted role that oxidative stress-mediated injury plays in the development of organ failure, there is still little conclusive evidence of any beneficial effect of systemic antioxidant supplementation in patients with sepsis and organ dysfunction. It has been suggested, however, that antioxidant therapy delivered specifically to mitochondria may be useful.

  6. Role for Mitochondrial Oxidants as Regulators of Cellular Metabolism

    PubMed Central

    Nemoto, Shino; Takeda, Kazuyo; Yu, Zu-Xi; Ferrans, Victor J.; Finkel, Toren

    2000-01-01

    Leakage of mitochondrial oxidants contributes to a variety of harmful conditions ranging from neurodegenerative diseases to cellular senescence. We describe here, however, a physiological and heretofore unrecognized role for mitochondrial oxidant release. Mitochondrial metabolism of pyruvate is demonstrated to activate the c-Jun N-terminal kinase (JNK). This metabolite-induced rise in cytosolic JNK1 activity is shown to be triggered by increased release of mitochondrial H2O2. We further demonstrate that in turn, the redox-dependent activation of JNK1 feeds back and inhibits the activity of the metabolic enzymes glycogen synthase kinase 3β and glycogen synthase. As such, these results demonstrate a novel metabolic regulatory pathway activated by mitochondrial oxidants. In addition, they suggest that although chronic oxidant production may have deleterious effects, mitochondrial oxidants can also function acutely as signaling molecules to provide communication between the mitochondria and the cytosol. PMID:10982848

  7. Modification of the association of bisphenol A with abnormal liver function by polymorphisms of oxidative stress-related genes.

    PubMed

    Kim, Jin Hee; Lee, Mee-Ri; Hong, Yun-Chul

    2016-05-01

    Some studies suggested oxidative stress as a possible mechanism for the relation between exposure to bisphenol A (BPA) and liver damage. Therefore, we evaluated modification of genetic polymorphisms of cyclooxygenase 2 (COX2 or PTGS2), epoxide hydrolase 1 (EPHX1), catalase (CAT), and superoxide dismutase 2 (SOD2 or MnSOD), which are oxidative stress-related genes, on the relation between exposure to BPA and liver function in the elderly. We assessed the association of visit-to-visit variations in BPA exposure with abnormal liver function by each genotype or haplotype after controlling for age, sex, BMI, alcohol consumption, exercise, urinary cotinine levels, and low density lipoprotein cholesterol using a GLIMMIX model. A significant association of BPA with abnormal liver function was observed only in participants with COX2 GG genotype at rs5277 (odds ratio (OR)=3.04 and p=0.0231), CAT genotype at rs769218 (OR=4.16 and p=0.0356), CAT CT genotype at rs769217 (OR=4.19 and p=0.0348), SOD2 TT genotype at rs4880 (OR=2.59 and p=0.0438), or SOD2 GG genotype at rs2758331 (OR=2.57 and p=0.0457). Moreover, we also found higher OR values in participants with a pair of G-G haplotypes for COX2 (OR=2.81 and p=0.0384), G-C-A haplotype for EPHX1 (OR=4.63 and p=0.0654), A-T haplotype for CAT (OR=4.48 and p=0.0245), or T-G-A haplotype for SOD2 (OR=2.91 and p=0.0491) compared with those with the other pair of haplotypes for each gene. Furthermore, the risk score composed of 4 risky pair of haplotypes showed interactive effect with BPA on abnormal liver function (p=0.0057). Our study results suggest that genetic polymorphisms of COX2, EPHX1, CAT, and SOD2 modify the association of BPA with liver function.

  8. Mitochondrial Fatty Acid Oxidation in Obesity

    PubMed Central

    Serra, Dolors; Mera, Paula; Malandrino, Maria Ida; Mir, Joan Francesc

    2013-01-01

    Abstract Significance: Current lifestyles with high-energy diets and little exercise are triggering an alarming growth in obesity. Excess of adiposity is leading to severe increases in associated pathologies, such as insulin resistance, type 2 diabetes, atherosclerosis, cancer, arthritis, asthma, and hypertension. This, together with the lack of efficient obesity drugs, is the driving force behind much research. Recent Advances: Traditional anti-obesity strategies focused on reducing food intake and increasing physical activity. However, recent results suggest that enhancing cellular energy expenditure may be an attractive alternative therapy. Critical Issues: This review evaluates recent discoveries regarding mitochondrial fatty acid oxidation (FAO) and its potential as a therapy for obesity. We focus on the still controversial beneficial effects of increased FAO in liver and muscle, recent studies on how to potentiate adipose tissue energy expenditure, and the different hypotheses involving FAO and the reactive oxygen species production in the hypothalamic control of food intake. Future Directions: The present review aims to provide an overview of novel anti-obesity strategies that target mitochondrial FAO and that will definitively be of high interest in the future research to fight against obesity-related disorders. Antioxid. Redox Signal. 19, 269–284. PMID:22900819

  9. A coulombic hypothesis of mitochondrial oxidative phosphorylation.

    PubMed

    Malpress, F H

    1984-08-21

    A coulombic hypothesis of mitochondrial oxidative phosphorylation is presented, founded upon the evidence for negative fixed charge formation during electron transport chain activity. The intermediary force is electrostatic (psi H) and not electrochemical (delta mu H). The electrochemical potential of the chemiosmotic hypothesis is identified as a "phantom" parameter which owes its delusive existence to the procedures by which it is measured. The connection between psi H and the conditional delta mu H values is examined; it entails the use of a variable conversion factor, f, where delta mu H (mV) = f psi H, and the concept of the "protonic status" of the diffuse double layer. A number of problems which beset the chemiosmotic view are reappraised in the light of the new interpretation, and find authentic solutions.

  10. Melatonin protects against common deletion of mitochondrial DNA-augmented mitochondrial oxidative stress and apoptosis.

    PubMed

    Jou, Mei-Jie; Peng, Tsung-I; Yu, Pai-Zu; Jou, Shuo-Bin; Reiter, Russel J; Chen, Jin-Yi; Wu, Hong-Yueh; Chen, Chih-Chun; Hsu, Lee-Fen

    2007-11-01

    Defected mitochondrial respiratory chain (RC), in addition to causing a severe ATP deficiency, often augments reactive oxygen species (ROS) generation in mitochondria (mROS) which enhances pathological conditions and diseases. Previously, we demonstrated a potent endogenously RC defect-augmented mROS associated dose-dependently with a commonly seen large-scale deletion of 4977 base pairs of mitochondrial DNA (mtDNA), i.e. the common deletion (CD). As current treatments for CD-associated diseases are rather supplementary and ineffective, we investigated whether melatonin, a potential mitochondrial protector, provides beneficial protection for CD-augmented mitochondrial oxidative stress and apoptosis particularly upon the induction of a secondary oxidative stress. Detailed mechanistic investigations were performed by using laser scanning dual fluorescence imaging microscopy to provide precise spatial and temporal resolution of mitochondrial events at single cell level. We demonstrate, for the first time, that melatonin significantly prevents CD-augmented mROS formation under basal conditions as well as at early time-points upon secondary oxidative stress induced by H2O2 exposure. Thus, melatonin prevents mROS-mediated depolarization of mitochondrial membrane potential (DeltaPsim) and subsequent opening of the mitochondrial permeability transition pore (MPTP) and cytochrome c release. Moreover, melatonin prevents depletion of cardiolipin which appears to be crucial for postponing later MPTP opening, disruption of the mitochondrial membrane and apoptosis. Finally, the protection provided by melatonin is superior to those caused by the suppression of mitochondrial Ca2+ regulators including the mitochondrial Na+-Ca2) exchanger, the MPTP, and the mitochondrial Ca2+ uniporter and by antioxidants including vitamin E and mitochondria-targeted coenzyme Q, MitoQ. As RC defect-augmented endogenous mitochondrial oxidative stress is centrally involved in a variety of pathological

  11. The Mitochondrial-Derived Peptide Humanin Protects RPE Cells From Oxidative Stress, Senescence, and Mitochondrial Dysfunction

    PubMed Central

    Sreekumar, Parameswaran G.; Ishikawa, Keijiro; Spee, Chris; Mehta, Hemal H.; Wan, Junxiang; Yen, Kelvin; Cohen, Pinchas; Kannan, Ram; Hinton, David R.

    2016-01-01

    Purpose To investigate the expression of humanin (HN) in human retinal pigment epithelial (hRPE) cells and its effect on oxidative stress–induced cell death, mitochondrial bioenergetics, and senescence. Methods Humanin localization in RPE cells and polarized RPE monolayers was assessed by confocal microscopy. Human RPE cells were treated with 150 μM tert-Butyl hydroperoxide (tBH) in the absence/presence of HN (0.5–10 μg/mL) for 24 hours. Mitochondrial respiration was measured by XF96 analyzer. Retinal pigment epithelial cell death and caspase-3 activation, mitochondrial biogenesis and senescence were analyzed by TUNEL, immunoblot analysis, mitochondrial DNA copy number, SA-β-Gal staining, and p16INK4a expression and HN levels by ELISA. Oxidative stress–induced changes in transepithelial resistance were studied in RPE monolayers with and without HN cotreatment. Results A prominent localization of HN was found in the cytoplasmic and mitochondrial compartments of hRPE. Humanin cotreatment inhibited tBH-induced reactive oxygen species formation and significantly restored mitochondrial bioenergetics in hRPE cells. Exogenous HN was taken up by RPE and colocalized with mitochondria. The oxidative stress–induced decrease in mitochondrial bioenergetics was prevented by HN cotreatment. Humanin treatment increased mitochondrial DNA copy number and upregulated mitochondrial transcription factor A, a key biogenesis regulator protein. Humanin protected RPE cells from oxidative stress–induced cell death by STAT3 phosphorylation and inhibiting caspase-3 activation. Humanin treatment inhibited oxidant-induced senescence. Polarized RPE demonstrated elevated cellular HN and increased resistance to cell death. Conclusions Humanin protected RPE cells against oxidative stress–induced cell death and restored mitochondrial function. Our data suggest a potential role for HN therapy in the prevention of retinal degeneration, including AMD. PMID:26990160

  12. Mitochondrial respiratory dysfunction-elicited oxidative stress and posttranslational protein modification in mitochondrial diseases.

    PubMed

    Wu, Yu-Ting; Wu, Shi-Bei; Lee, Wan-Yu; Wei, Yau-Huei

    2010-07-01

    Pathogenic mutation in mtDNA and mitochondrial dysfunction are associated with mitochondrial diseases. In this review, we discuss the oxidative stress-elicited mitochondrial protein modifications that may contribute to the pathophysiology of mitochondrial diseases. We demonstrated that excess ROS produced by defective mitochondria could increase the acetylation of microtubule proteins through the suppression of Sirt2, which results in perinuclear distribution of mitochondria in skin fibroblasts of patients with CPEO syndrome. Our recent work showed that mitochondrial dysfunction-induced oxidative stress can disrupt protein degradation system by inhibiting the ubiquitin-proteasome pathway and protease activity in human cells harboring mutant mtDNA. This in turn causes accumulation of aberrant proteins in mitochondria and renders the mutant cells more susceptible to apoptosis induced by oxidative stress. Furthermore, oxidative stress can modulate phosphorylation of mitochondrial proteins, which can affect metabolism in a number of diseases. Taken together, we suggest that oxidative stress-triggered protein modifications and defects in protein turnover play an important role in the pathogenesis and progression of mitochondrial diseases.

  13. Sulforaphane Inhibits Mitochondrial Permeability Transition and Oxidative Stress

    PubMed Central

    Greco, Tiffany; Shafer, Jonathan; Fiskum, Gary

    2012-01-01

    Exposure of mitochondria to oxidative stress and elevated Ca2+ promotes opening of the mitochondrial permeability transition pore (PTP), resulting in membrane depolarization, uncoupling of oxidative phosphorylation, and potentially cell death. This study tested the hypothesis that treatment of rats with sulforaphane (SFP), an activator of the Nrf2 pathway of antioxidant gene expression, increases the resistance of liver mitochondria to redox-regulated PTP opening and elevates mitochondrial levels of antioxidants. Rats were injected with SFP or drug vehicle and liver mitochondria were isolated 40 hr later. Respiring mitochondria actively accumulated added Ca2+, which was then released through PTP opening induced by agents that either cause an oxidized shift in the mitochondrial redox state or that directly oxidize protein thiol groups. SFP treatment of rats inhibited the rate of pro-oxidant-induced mitochondrial Ca2+ release and increased expression of the glutathione peroxidase/reductase system, thioredoxin, and malic enzyme. These results are the first to demonstrate that SFP treatment of animals increases liver mitochondrial antioxidant defenses and inhibits redox-sensitive PTP opening. This novel form of preconditioning could protect against a variety of pathologies that include oxidative stress and mitochondrial dysfunction in their etiologies. PMID:21986339

  14. Mitochondrial matrix P53 sensitizes cells to oxidative stress☆

    PubMed Central

    Koczor, Christopher A.; Torres, Rebecca A.; Fields, Earl J.; Boyd, Amy; Lewis, William

    2013-01-01

    A mitochondrial matrix-specific p53 construct (termed p53–290) in HepG2 cells was utilized to determine the impact of p53 in the mitochondrial matrix following oxidative stress. H2O2 exposure reduced cellular proliferation similarly in both p53–290 and vector cells, and p53–290 cells demonstrating decreased cell viability at 1 mM H2O2 (~85% viable). Mitochondrial DNA (mtDNA) abundance was decreased in a dose-dependent manner in p53–290 cells while no change was observed in vector cells. Oximetric analysis revealed reduced maximal respiration and reserve capacity in p53–290 cells. Our results demonstrate that mitochondrial matrix p53 sensitizes cells to oxidative stress by reducing mtDNA abundance and mitochondrial function. PMID:23499753

  15. Development and characterization of a hydrogen peroxide-resistant cholangiocyte cell line: A novel model of oxidative stress-related cholangiocarcinoma genesis

    SciTech Connect

    Thanan, Raynoo; Techasen, Anchalee; Hou, Bo; Jamnongkan, Wassana; Armartmuntree, Napat; Yongvanit, Puangrat; Murata, Mariko

    2015-08-14

    Oxidative stress is a cause of inflammation–related diseases, including cancers. Cholangiocarcinoma is a liver cancer with bile duct epithelial cell phenotypes. Our previous studies in animal and human models indicated that oxidative stress is a major cause of cholangiocarcinoma development. Hydrogen peroxide (H{sub 2}O{sub 2}) can generate hydroxyl radicals, which damage lipids, proteins, and nucleic acids, leading to cell death. However, some cells can survive by adapting to oxidative stress conditions, and selective clonal expansion of these resistant cells would be involved in oxidative stress-related carcinogenesis. The present study aimed to establish H{sub 2}O{sub 2}-resistant cell line from an immortal cholangiocyte cell line (MMNK1) by chronic treatment with low-concentration H{sub 2}O{sub 2} (25 μM). After 72 days of induction, H{sub 2}O{sub 2}-resistant cell lines (ox-MMNK1-L) were obtained. The ox-MMNK1-L cell line showed H{sub 2}O{sub 2}-resistant properties, increasing the expression of the anti-oxidant genes catalase (CAT), superoxide dismutase-1 (SOD1), superoxide dismutase-2 (SOD2), and superoxide dismutase-3 (SOD3) and the enzyme activities of CAT and intracellular SODs. Furthermore, the resistant cells showed increased expression levels of an epigenetics-related gene, DNA methyltransferase-1 (DNMT1), when compared to the parental cells. Interestingly, the ox-MMNK1-L cell line had a significantly higher cell proliferation rate than the MMNK1 normal cell line. Moreover, ox-MMNK1-L cells showed pseudopodia formation and the loss of cell-to-cell adhesion (multi-layers) under additional oxidative stress (100 μM H{sub 2}O{sub 2}). These findings suggest that H{sub 2}O{sub 2}-resistant cells can be used as a model of oxidative stress-related cholangiocarcinoma genesis through molecular changes such as alteration of gene expression and epigenetic changes. - Highlights: • An H{sub 2}O{sub 2}-resistant ox-MMNK1-L cells was established from

  16. Oxidative stress induces mitochondrial fragmentation in frataxin-deficient cells

    SciTech Connect

    Lefevre, Sophie; Sliwa, Dominika; Rustin, Pierre; Camadro, Jean-Michel; Santos, Renata

    2012-02-10

    Highlights: Black-Right-Pointing-Pointer Yeast frataxin-deficiency leads to increased proportion of fragmented mitochondria. Black-Right-Pointing-Pointer Oxidative stress induces complete mitochondrial fragmentation in {Delta}yfh1 cells. Black-Right-Pointing-Pointer Oxidative stress increases mitochondrial fragmentation in patient fibroblasts. Black-Right-Pointing-Pointer Inhibition of mitochondrial fission in {Delta}yfh1 induces oxidative stress resistance. -- Abstract: Friedreich ataxia (FA) is the most common recessive neurodegenerative disease. It is caused by deficiency in mitochondrial frataxin, which participates in iron-sulfur cluster assembly. Yeast cells lacking frataxin ({Delta}yfh1 mutant) showed an increased proportion of fragmented mitochondria compared to wild-type. In addition, oxidative stress induced complete fragmentation of mitochondria in {Delta}yfh1 cells. Genetically controlled inhibition of mitochondrial fission in these cells led to increased resistance to oxidative stress. Here we present evidence that in yeast frataxin-deficiency interferes with mitochondrial dynamics, which might therefore be relevant for the pathophysiology of FA.

  17. Oxidative stress and mitochondrial protein quality control in aging.

    PubMed

    Lionaki, Eirini; Tavernarakis, Nektarios

    2013-10-30

    Mitochondrial protein quality control incorporates an elaborate network of chaperones and proteases that survey the organelle for misfolded or unfolded proteins and toxic aggregates. Repair of misfolded or aggregated protein and proteolytic removal of irreversibly damaged proteins are carried out by the mitochondrial protein quality control system. Initial maturation and folding of the nuclear or mitochondrial-encoded mitochondrial proteins are mediated by processing peptidases and chaperones that interact with the protein translocation machinery. Mitochondrial proteins are subjected to cumulative oxidative damage. Thus, impairment of quality control processes may cause mitochondrial dysfunction. Aging has been associated with a marked decline in the effectiveness of mitochondrial protein quality control. Here, we present an overview of the chaperones and proteases involved in the initial folding and maturation of new, incoming precursor molecules, and the subsequent repair and removal of oxidized aggregated proteins. In addition, we highlight the link between mitochondrial protein quality control mechanisms and the aging process. This article is part of a Special Issue entitled: Posttranslational Protein modifications in biology and Medicine. Copyright © 2013 Elsevier B.V. All rights reserved.

  18. Characteristics and function of cardiac mitochondrial nitric oxide synthase.

    PubMed

    Dedkova, Elena N; Blatter, Lothar A

    2009-02-15

    We used laser scanning confocal microscopy in combination with the nitric oxide (NO)-sensitive fluorescent dye DAF-2 and the reactive oxygen species (ROS)-sensitive dyes CM-H(2)DCF and MitoSOX Red to characterize NO and ROS production by mitochondrial NO synthase (mtNOS) in permeabilized cat ventricular myocytes. Stimulation of mitochondrial Ca(2+) uptake by exposure to different cytoplasmic Ca(2+) concentrations ([Ca(2+)](i) = 1, 2 and 5 microm) resulted in a dose-dependent increase of NO production by mitochondria when L-arginine, a substrate for mtNOS, was present. Collapsing the mitochondrial membrane potential with the protonophore FCCP or blocking the mitochondrial Ca(2+) uniporter with Ru360 as well as blocking the respiratory chain with rotenone or antimycin A in combination with oligomycin inhibited mitochondrial NO production. In the absence of L-arginine, mitochondrial NO production during stimulation of Ca(2+) uptake was significantly decreased, but accompanied by increase in mitochondrial ROS production. Inhibition of mitochondrial arginase to limit L-arginine availability resulted in 50% inhibition of Ca(2+)-induced ROS production. Both mitochondrial NO and ROS production were blocked by the nNOS inhibitor (4S)-N-(4-amino-5[aminoethyl]aminopentyl)-N'-nitroguanidine and the calmodulin antagonist W-7, while the eNOS inhibitor L-N(5)-(1-iminoethyl)ornithine (L-NIO) or iNOS inhibitor N-(3-aminomethyl)benzylacetamidine, 2HCl (1400W) had no effect. The superoxide dismutase mimetic and peroxynitrite scavenger MnTBAP abolished Ca(2+)-induced ROS generation and increased NO production threefold, suggesting that in the absence of MnTBAP either formation of superoxide radicals suppressed NO production or part of the formed NO was transformed quickly to peroxynitrite. In the absence of L-arginine, mitochondrial Ca(2+) uptake induced opening of the mitochondrial permeability transition pore (PTP), which was blocked by the PTP inhibitor cyclosporin A and Mn

  19. Apigenin attenuates dopamine-induced apoptosis in melanocytes via oxidative stress-related p38, c-Jun NH2-terminal kinase and Akt signaling.

    PubMed

    Lin, Mao; Lu, Shan-Shan; Wang, Ao-Xue; Qi, Xiao-Yi; Zhao, Dan; Wang, Zhao-Hui; Man, Mao-Qiang; Tu, Cai-Xia

    2011-07-01

    Accumulating evidence suggests that the occurrence of oxidative stress leads to melanocyte degeneration in vitiligo. Elevated level of dopamine (DA), an initiator of oxidative stress, reportedly is found in patients with vitiligo and induces melanocyte death in vitro. DA-treated melanocytes have been used as a model to search for antioxidants for treating vitiligo. We investigated the protective effects of apigenin against DA-induced apoptosis in melanocytes and the molecular mechanism underlying those effects. Melanocytes with or without pretreatment with apigenin were exposed to DA. Then cell viabilities were measured by MTT assay. Cellular reactive oxygen species (ROS) levels and the percentage of apoptotic cells were detected by flow cytometry analysis. Activation of caspase 3, poly(ADP-ribose) polymerase (PARP) and oxidative stress-related signaling, including p38, c-Jun NH2-terminal kinase (JNK) and Akt, were assessed by Western blotting. Apigenin attenuated DA-induced apoptotic cell death, relieved ROS accumulation and activated caspase 3 and PARP, suggesting the protective effects of apigenin against DA-induced oxidative stress and apoptosis in melanocytes. Moreover, DA induced phosphorylation of p38, JNK and Akt, while inhibitors of p38, JNK and Akt significantly decreased DA-induced apoptosis. However, pretreatment with apigenin significantly inhibited DA-triggered activation of p38, JNK and Akt, suggesting the involvement of p38, JNK and Akt in the protective effects of apigenin against DA-induced cytotoxicity. These results suggest that apigenin attenuates dopamine-induced apoptosis in melanocytes via oxidative stress-related p38, JNK and Akt signaling and therefore could be a potential agent in treating vitiligo. Copyright © 2011 Japanese Society for Investigative Dermatology. Published by Elsevier Ireland Ltd. All rights reserved.

  20. Effects of glutamine supplementation on oxidative stress-related gene expression and antioxidant properties in rats with streptozotocin-induced type 2 diabetes.

    PubMed

    Tsai, Pei-Hsuan; Liu, Jun-Jen; Yeh, Chui-Li; Chiu, Wan-Chun; Yeh, Sung-Ling

    2012-04-01

    There are close links among hyperglycaemia, oxidative stress and diabetic complications. Glutamine (GLN) is an amino acid with immunomodulatory properties. The present study investigated the effect of dietary GLN on oxidative stress-relative gene expressions and tissue oxidative damage in diabetes. There were one normal control (NC) and two diabetic groups in the present study. Diabetes was induced by an intraperitoneal injection of nicotinamide followed by streptozotocin (STZ). Rats in the NC group were fed a regular chow diet. In the two diabetic groups, one group (diabetes mellitus, DM) was fed a common semi-purified diet while the other group received a diet in which part of the casein was replaced by GLN (DM-GLN). GLN provided 25% of total amino acid N. The experimental groups were fed the respective diets for 8 weeks, and then the rats were killed for further analysis. The results showed that blood thioredoxin-interacting protein (Txnip) mRNA expression in the diabetic groups was higher than that in the NC group. Compared with the DM group, the DM-GLN group had lower glutamine fructose-6-phosphate transaminase 1, a receptor of advanced glycation end products, and Txnip gene expressions in blood mononuclear cells. The total antioxidant capacity was lower and antioxidant enzyme activities were altered by the diabetic condition. GLN supplementation increased antioxidant capacity and normalised antioxidant enzyme activities. Also, the renal nitrotyrosine level and Txnip mRNA expression were lower when GLN was administered. These results suggest that dietary GLN supplementation decreases oxidative stress-related gene expression, increases the antioxidant potential and may consequently attenuate renal oxidative damage in rats with STZ-induced diabetes.

  1. Oxidative DNA damage causes mitochondrial genomic instability in Saccharomyces cerevisiae.

    PubMed

    Doudican, Nicole A; Song, Binwei; Shadel, Gerald S; Doetsch, Paul W

    2005-06-01

    Mitochondria contain their own genome, the integrity of which is required for normal cellular energy metabolism. Reactive oxygen species (ROS) produced by normal mitochondrial respiration can damage cellular macromolecules, including mitochondrial DNA (mtDNA), and have been implicated in degenerative diseases, cancer, and aging. We developed strategies to elevate mitochondrial oxidative stress by exposure to antimycin and H(2)O(2) or utilizing mutants lacking mitochondrial superoxide dismutase (sod2Delta). Experiments were conducted with strains compromised in mitochondrial base excision repair (ntg1Delta) and oxidative damage resistance (pif1Delta) in order to delineate the relationship between these pathways. We observed enhanced ROS production, resulting in a direct increase in oxidative mtDNA damage and mutagenesis. Repair-deficient mutants exposed to oxidative stress conditions exhibited profound genomic instability. Elimination of Ntg1p and Pif1p resulted in a synergistic corruption of respiratory competency upon exposure to antimycin and H(2)O(2). Mitochondrial genomic integrity was substantially compromised in ntg1Delta pif1Delta sod2Delta strains, since these cells exhibit a total loss of mtDNA. A stable respiration-defective strain, possessing a normal complement of mtDNA damage resistance pathways, exhibited a complete loss of mtDNA upon exposure to antimycin and H(2)O(2). This loss was preventable by Sod2p overexpression. These results provide direct evidence that oxidative mtDNA damage can be a major contributor to mitochondrial genomic instability and demonstrate cooperation of Ntg1p and Pif1p to resist the introduction of lesions into the mitochondrial genome.

  2. Mitochondrial oxidative stress significantly influences atherogenic risk and cytokine-induced oxidant production.

    PubMed

    Harrison, Corey M; Pompilius, Melissa; Pinkerton, Kent E; Ballinger, Scott W

    2011-05-01

    Oxidative stress associated with cardiovascular disease (CVD) risk factors contributes to disease development. However, less is known whether specific subcellular components play a role in disease susceptibility. In this regard, it has been previously reported that vascular mitochondrial damage and dysfunction are associated with atherosclerosis. However, no studies have determined whether altered mitochondrial oxidant production directly influences atherogenic susceptibility and response in primary cells to atherogenic factors such as tumor necrosis factor-α (TNF-α). We undertook this study to determine whether increased mitochondrial oxidant production affects atherosclerotic lesion development associated with CVD risk factor exposure and endothelial cell response to TNF-α. We assessed atherosclerotic lesion formation, oxidant stress, and mitochondrial DNA damage in male apolipoprotein E (apoE)-null mice with normal and decreased levels of mitochondrial superoxide dismutase-2 (SOD2; apoE(-/-) and apoE(-/-), SOD2(+/-), respectively) exposed to environmental tobacco smoke or filtered air. Atherogenesis, oxidative stress, and mitochondrial damage were significantly higher in apoE(-/-), SOD2(+/-) mice than in apoE(-/-) controls. Furthermore, experiments with small interfering RNA in endothelial cells revealed that decreased SOD2 activity increased TNF-α-mediated cellular oxidant levels compared with controls. Endogenous mitochondrial oxidative stress is an important CVD risk factor that can modulate atherogenesis and cytokine-induced endothelial cell oxidant generation. Consequently, CVD risk factors that induce mitochondrial damage alter cellular response to endogenous atherogenic factors, increasing disease susceptibility.

  3. NITRIC OXIDE, MITOCHONDRIAL HYPERPOLARIZATION AND T-CELL ACTIVATION

    PubMed Central

    Nagy, Gyorgy; Koncz, Agnes; Fernandez, David; Perl, Andras

    2007-01-01

    T lymphocyte activation is associated with nitric oxide (NO) production that plays an essential role in multiple T cell functions. NO acts as a messenger, activating soluble guanyl cyclase and participating in the transduction signaling pathways involving cyclic GMP. NO modulates mitochondrial events that are involved in apoptosis and regulates mitochondrial membrane potential and mitochondrial biogenesis in many cell types, including lymphocytes. Mitochondrial hyperpolarization (MHP), an early and reversible event during both T lymphocyte activation and apoptosis, is regulated by NO. Here, we discuss recent evidence that NO-induced MHP represents a molecular switch in multiple T cell signaling pathways. Overproduction of NO in systemic lupus erythematosus (SLE) induces mitochondrial biogenesis and alters Ca2+ signaling. Thus, while NO plays a physiological role in lymphocyte cell signaling, its overproduction may disturb normal T cell function, contributing to the pathogenesis of autoimmunity. PMID:17462531

  4. Oxidative stress and mitochondrial dysfunction in Kindler syndrome.

    PubMed

    Zapatero-Solana, Elisabeth; García-Giménez, Jose Luis; Guerrero-Aspizua, Sara; García, Marta; Toll, Agustí; Baselga, Eulalia; Durán-Moreno, Maria; Markovic, Jelena; García-Verdugo, Jose Manuel; Conti, Claudio J; Has, Cristina; Larcher, Fernando; Pallardó, Federico V; Del Rio, Marcela

    2014-12-21

    Kindler Syndrome (KS) is an autosomal recessive skin disorder characterized by skin blistering, photosensitivity, premature aging, and propensity to skin cancer. In spite of the knowledge underlying cause of this disease involving mutations of FERMT1 (fermitin family member 1), and efforts to characterize genotype-phenotype correlations, the clinical variability of this genodermatosis is still poorly understood. In addition, several pathognomonic features of KS, not related to skin fragility such as aging, inflammation and cancer predisposition have been strongly associated with oxidative stress. Alterations of the cellular redox status have not been previously studied in KS. Here we explored the role of oxidative stress in the pathogenesis of this rare cutaneous disease. Patient-derived keratinocytes and their respective controls were cultured and classified according to their different mutations by PCR and western blot, the oxidative stress biomarkers were analyzed by spectrophotometry and qPCR and additionally redox biosensors experiments were also performed. The mitochondrial structure and functionality were analyzed by confocal microscopy and electron microscopy. Patient-derived keratinocytes showed altered levels of several oxidative stress biomarkers including MDA (malondialdehyde), GSSG/GSH ratio (oxidized and reduced glutathione) and GCL (gamma-glutamyl cysteine ligase) subunits. Electron microscopy analysis of both, KS skin biopsies and keratinocytes showed marked morphological mitochondrial abnormalities. Consistently, confocal microscopy studies of mitochondrial fluorescent probes confirmed the mitochondrial derangement. Imbalance of oxidative stress biomarkers together with abnormalities in the mitochondrial network and function are consistent with a pro-oxidant state. This is the first study to describe mitochondrial dysfunction and oxidative stress involvement in KS.

  5. Storing red blood cells with vitamin C and N-acetylcysteine prevents oxidative stress-related lesions: a metabolomics overview

    PubMed Central

    Pallotta, Valeria; Gevi, Federica; D’Alessandro, Angelo; Zolla, Lello

    2014-01-01

    Background Recent advances in red blood cell metabolomics have paved the way for further improvements of storage solutions. Materials and methods In the present study, we exploited a validated high performance liquid chromatography-mass spectrometry analytical workflow to determine the effects of vitamin C and N-acetylcysteine supplementation (anti-oxidants) on the metabolome of erythrocytes stored in citrate-phosphate-dextrose saline-adenine-glucose-mannitol medium under blood bank conditions. Results We observed decreased energy metabolism fluxes (glycolysis and pentose phosphate pathway). A tentative explanation of this phenomenon could be related to the observed depression of the uptake of glucose, since glucose and ascorbate are known to compete for the same transporter. Anti-oxidant supplementation was effective in modulating the redox poise, through the promotion of glutathione homeostasis, which resulted in decreased haemolysis and less accumulation of malondialdehyde and oxidation by-products (including oxidized glutathione and prostaglandins). Discussion Anti-oxidants improved storage quality by coping with oxidative stress at the expense of glycolytic metabolism, although reservoirs of high energy phosphate compounds were preserved by reduced cyclic AMP-mediated release of ATP. PMID:25074788

  6. Oxidized mitochondrial DNA activates the NLRP3 inflammasome during apoptosis.

    PubMed

    Shimada, Kenichi; Crother, Timothy R; Karlin, Justin; Dagvadorj, Jargalsaikhan; Chiba, Norika; Chen, Shuang; Ramanujan, V Krishnan; Wolf, Andrea J; Vergnes, Laurent; Ojcius, David M; Rentsendorj, Altan; Vargas, Mario; Guerrero, Candace; Wang, Yinsheng; Fitzgerald, Katherine A; Underhill, David M; Town, Terrence; Arditi, Moshe

    2012-03-23

    We report that in the presence of signal 1 (NF-κB), the NLRP3 inflammasome was activated by mitochondrial apoptotic signaling that licensed production of interleukin-1β (IL-1β). NLRP3 secondary signal activators such as ATP induced mitochondrial dysfunction and apoptosis, resulting in release of oxidized mitochondrial DNA (mtDNA) into the cytosol, where it bound to and activated the NLRP3 inflammasome. The antiapoptotic protein Bcl-2 inversely regulated mitochondrial dysfunction and NLRP3 inflammasome activation. Mitochondrial DNA directly induced NLRP3 inflammasome activation, because macrophages lacking mtDNA had severely attenuated IL-1β production, yet still underwent apoptosis. Both binding of oxidized mtDNA to the NLRP3 inflammasome and IL-1β secretion could be competitively inhibited by the oxidized nucleoside 8-OH-dG. Thus, our data reveal that oxidized mtDNA released during programmed cell death causes activation of the NLRP3 inflammasome. These results provide a missing link between apoptosis and inflammasome activation, via binding of cytosolic oxidized mtDNA to the NLRP3 inflammasome.

  7. Oxidized Mitochondrial DNA Activates the NLRP3 Inflammasome During Apoptosis

    PubMed Central

    Shimada, Kenichi; Crother, Timothy R.; Karlin, Justin; Dagvadorj, Jargalsaikhan; Chiba, Norika; Chen, Shuang; Ramanujan, V. Krishnan; Wolf, Andrea J.; Vergnes, Laurent; Ojcius, David M.; Rentsendorj, Altan; Vargas, Mario; Guerrero, Candace; Wang, Yinsheng; Fitzgerald, Katherine A.; Underhill, David M.; Town, Terrence; Arditi, Moshe

    2012-01-01

    SUMMARY We report that in the presence of signal 1 (NF-κB), the NLRP3 inflammasome was activated by mitochondrial apoptotic signaling that licensed production of interleukin-1β (IL-1β). NLRP3 secondary signal activators such as ATP induced mitochondrial dysfunction and apoptosis, resulting in release of oxidized mitochondrial DNA (mtDNA) into the cytosol, where it bound to and activated the NLRP3 inflammasome. The anti-apoptotic protein Bcl-2 inversely regulated mitochondrial dysfunction and NLRP3 inflammasome activation. Mitochondrial DNA directly induced NLRP3 inflammasome activation, because macrophages lacking mtDNA had severely attenuated IL-1β production, yet still underwent apoptosis. Both binding of oxidized mtDNA to the NLRP3 inflammasome and IL-1β secretion could be competitively inhibited by the oxidized nucleoside, 8-OH-dG. Thus, our data reveal that oxidized mtDNA released during programmed cell death causes activation of the NLRP3 inflammasome. These results provide a missing link between apoptosis and inflammasome activation, via binding of cytosolic oxidized mtDNA to the NLRP3 inflammasome. PMID:22342844

  8. Nitric oxide affects plant mitochondrial functionality in vivo.

    PubMed

    Zottini, Michela; Formentin, Elide; Scattolin, Michela; Carimi, Francesco; Lo Schiavo, Fiorella; Terzi, Mario

    2002-03-27

    In this report, we show that nitric oxide affects mitochondrial functionality in plant cells and reduces total cell respiration due to strong inhibition of the cytochrome pathway. The residual respiration depends on the alternative pathway and novel synthesis of alternative oxidase occurs. These modifications are associated with depolarisation of the mitochondrial membrane potential and release of cytochrome c from mitochondria, suggesting a conserved signalling pathway in plants and animals. This signal cascade is triggered at the mitochondrial level and induces about 20% of cell death. In order to achieve a higher level of cell death, the addition of H(2)O(2) is necessary.

  9. Elevated mitochondrial oxidative stress impairs metabolic adaptations to exercise in skeletal muscle.

    PubMed

    Crane, Justin D; Abadi, Arkan; Hettinga, Bart P; Ogborn, Daniel I; MacNeil, Lauren G; Steinberg, Gregory R; Tarnopolsky, Mark A

    2013-01-01

    Mitochondrial oxidative stress is a complex phenomenon that is inherently tied to energy provision and is implicated in many metabolic disorders. Exercise training increases mitochondrial oxidative capacity in skeletal muscle yet it remains unclear if oxidative stress plays a role in regulating these adaptations. We demonstrate that the chronic elevation in mitochondrial oxidative stress present in Sod2 (+/-) mice impairs the functional and biochemical mitochondrial adaptations to exercise. Following exercise training Sod2 (+/-) mice fail to increase maximal work capacity, mitochondrial enzyme activity and mtDNA copy number, despite a normal augmentation of mitochondrial proteins. Additionally, exercised Sod2 (+/-) mice cannot compensate for their higher amount of basal mitochondrial oxidative damage and exhibit poor electron transport chain complex assembly that accounts for their compromised adaptation. Overall, these results demonstrate that chronic skeletal muscle mitochondrial oxidative stress does not impact exercise induced mitochondrial biogenesis, but impairs the resulting mitochondrial protein function and can limit metabolic plasticity.

  10. Dexamethasone and 1,25-dihydroxyvitamin D3 reduce oxidative stress-related DNA damage in differentiating osteoblasts.

    PubMed

    Pawlowska, Elzbieta; Wysokiński, Daniel; Tokarz, Paulina; Piastowska-Ciesielska, Agnieszka; Szczepanska, Joanna; Blasiak, Janusz

    2014-09-19

    The process of osteoblast differentiation is regulated by several factors, including RUNX2. Recent reports suggest an involvement of RUNX2 in DNA damage response (DDR), which is important due to association of differentiation with oxidative stress. In the present work we explore the influence of two RUNX2 modifiers, dexamethasone (DEX) and 1,25-dihydroxyvitamin D3 (1,25-D3), in DDR in differentiating MC3T3-E1 preosteoblasts challenged by oxidative stress. The process of differentiation was associated with reactive oxygen species (ROS) production and tert-butyl hydroperoxide (TBH) reduced the rate of differentiation. The activity of alkaline phosphatase (ALP), a marker of the process of osteoblasts differentiation, increased in a time-dependent manner and TBH further increased this activity. This may indicate that additional oxidative stress, induced by TBH, may accelerate the differentiation process. The cells displayed changes in the sensitivity to TBH in the course of differentiation. DEX increased ALP activity, but 1,25-D3 had no effect on it. These results suggest that DEX might stimulate the process of preosteoblasts differentiation. Finally, we observed a protective effect of DEX and 1,25-D3 against DNA damage induced by TBH, except the day 24 of differentiation, when DEX increased the extent of TBH-induced DNA damage. We conclude that oxidative stress is associated with osteoblasts differentiation and induce DDR, which may be modulated by RUNX2-modifiers, DEX and 1,25-D3.

  11. Changes in expression of oxidative stress related genes in grapefruit peel in response to yeast Metschnikowia fructicola

    USDA-ARS?s Scientific Manuscript database

    To gain insight into the mode of action of the yeast biocontrol agent, Metschnikowia fructicola, the transcription profiles of genes involved in oxidative stress were studied in grapefruit (Citrus paradis, 'Star Ruby') surface wounds following the application of the yeast antagonist. Three transcri...

  12. Tamoxifen inhibits mitochondrial oxidative stress damage induced by copper orthophenanthroline.

    PubMed

    Buelna-Chontal, Mabel; Hernández-Esquivel, Luz; Correa, Francisco; Díaz-Ruiz, Jorge Luis; Chávez, Edmundo

    2016-12-01

    In this work, we studied the effect of tamoxifen and cyclosporin A on mitochondrial permeability transition caused by addition of the thiol-oxidizing pair Cu(2+) -orthophenanthroline. The findings indicate that tamoxifen and cyclosporin A circumvent the oxidative membrane damage manifested by matrix Ca(2+) release, mitochondrial swelling, and transmembrane electrical gradient collapse. Furthermore, it was found that tamoxifen and cyclosporin A prevent the generation of TBARs promoted by Cu(2+) -orthophenanthroline, as well as the inactivation of the mitochondrial enzyme aconitase and disruption of mDNA. Electrophoretic analysis was unable to demonstrate a cross-linking reaction between membrane proteins. Yet, it was found that Cu(2+) -orthophenanthroline induced the generation of reactive oxygen species. It is thus plausible that membrane leakiness is due to an oxidative stress injury.

  13. Mitochondrial glycolate oxidation contributes to photorespiration in higher plants.

    PubMed

    Niessen, Markus; Thiruveedhi, Krishnaveni; Rosenkranz, Ruben; Kebeish, Rashad; Hirsch, Heinz-Josef; Kreuzaler, Fritz; Peterhänsel, Christoph

    2007-01-01

    The oxidation of glycolate to glyoxylate is an important reaction step in photorespiration. Land plants and charophycean green algae oxidize glycolate in the peroxisome using oxygen as a co-factor, whereas chlorophycean green algae use a mitochondrial glycolate dehydrogenase (GDH) with organic co-factors. Previous analyses revealed the existence of a GDH in the mitochondria of Arabidopsis thaliana (AtGDH). In this study, the contribution of AtGDH to photorespiration was characterized. Both RNA abundance and mitochondrial GDH activity were up-regulated under photorespiratory growth conditions. Labelling experiments indicated that glycolate oxidation in mitochondrial extracts is coupled to CO(2) release. This effect could be enhanced by adding co-factors for aminotransferases, but is inhibited by the addition of glycine. T-DNA insertion lines for AtGDH show a drastic reduction in mitochondrial GDH activity and CO(2) release from glycolate. Furthermore, photorespiration is reduced in these mutant lines compared with the wild type, as revealed by determination of the post-illumination CO(2) burst and the glycine/serine ratio under photorespiratory growth conditions. The data show that mitochondrial glycolate oxidation contributes to photorespiration in higher plants. This indicates the conservation of chlorophycean photorespiration in streptophytes despite the evolution of leaf-type peroxisomes.

  14. Effect of copper-hydroquinone complex on oxidative stress-related parameters in human erythrocytes (in vitro).

    PubMed

    Sarkar, Chandan; Mitra, Prasanta Kumar; Saha, Shyamaprasad; Nayak, Chittaranjan; Chakraborty, Ranadhir

    2009-02-01

    The effect of in vitro exposure of human erythrocytes to micromolar concentrations of hydroquinone and copper simultaneously on oxidative status-related biochemical parameters was studied. Hydroquinone is a component of cigarette smoke and serum copper level is increased in smokers. Copper forms a complex with hydroquinone and enhances its auto-oxidation to benzoquinone which covalently binds to sulfhydryl group containing compounds like reduced glutathione. In this study, copper increased H(2)O(2) production by hydroquinone. Hydroquinone either alone or in the presence of copper produced a decrease of reduced glutathione level without altering methemoglobin concentration and erythrocyte lipid peroxidation. Catalase inhibition by sodium azide depleted reduced glutathione level further. Copper-hydroquinone complex mediated glutathione depletion in the catalase containing RBC was not decreased by antioxidant, butylated hydroxytoluene. From the known facts and above findings, it is suggested that depletion of reduced glutathione by hydroquinone in the presence of copper in catalase active RBC may be due to the formation of 1, 4 benzoquinone adduct of reduced glutathione and to some extent due to binding of copper to the thiol group of reduced glutathione rather than conversion to oxidized glutathione via reactive oxygen species. Depletion of reduced glutathione by N-ethylmaleimide pretreatment followed by copper-hydroquinone treatment had no effect on methemoglobin level or lipid peroxidation. Furthermore, copper-hydroquinone complex did not increase erythrocyte susceptibility to oxidative stress. This suggests hydroquinone in the presence of copper does not contribute to erythrocyte membrane lipid peroxidation seen in smokers. Criteria for ideal antioxidant supplementation in smokers were suggested.

  15. Upregulation of Oxidative Stress Related Genes in a Chronic Kidney Disease Attributed to Specific Geographical Locations of Sri Lanka

    PubMed Central

    Sayanthooran, Saravanabavan; Gunerathne, Lishanthe; Abeysekera, Tilak D. J.; Sooriyapathirana, Suneth S.

    2016-01-01

    Objective. To infer the influence of internal and external oxidative stress in chronic kidney disease patients of unknown etiology (CKDu) in Sri Lanka, by analyzing expression of genes related directly or indirectly to oxidative stress: glutamate-cysteine ligase catalytic subunit (GCLC), glutathione S-transferase mu 1 (GSTM1), glucose-6-phosphate dehydrogenase (G6PD), fibroblast growth factor-23 (FGF23), and NLR family pyrin domain containing 3 (NLRP3). Methods. Reverse transcription quantitative polymerase chain reaction (RT-qPCR) was carried out for the selected populations: CKDu patients (n = 43), chronic kidney disease patients (CKD; n = 14), healthy individuals from a CKDu endemic area (GHI; n = 9), and nonendemic area (KHI; n = 16). Fold changes were quantified relative to KHI. Results. GCLC had greater than threefold upregulation in all three study groups, with a maximum of 7.27-fold upregulation in GHI (p = 0.000). GSTM1 was not expressed in 25.6% of CKDu and 42.9% of CKD patients, but CKDu patients expressing GSTM1 showed upregulation of 2.60-fold (p < 0.05). Upregulation of FGF23 and NLRP3 genes in CKD and CKDu was observed (p < 0.01), with greater fold changes in CKD. Conclusion. Results suggest higher influence of external sources of oxidative stress in CKDu, possibly owing to environmental conditions. PMID:27975059

  16. Upregulation of Oxidative Stress Related Genes in a Chronic Kidney Disease Attributed to Specific Geographical Locations of Sri Lanka.

    PubMed

    Sayanthooran, Saravanabavan; Magana-Arachchi, Dhammika N; Gunerathne, Lishanthe; Abeysekera, Tilak D J; Sooriyapathirana, Suneth S

    2016-01-01

    Objective. To infer the influence of internal and external oxidative stress in chronic kidney disease patients of unknown etiology (CKDu) in Sri Lanka, by analyzing expression of genes related directly or indirectly to oxidative stress: glutamate-cysteine ligase catalytic subunit (GCLC), glutathione S-transferase mu 1 (GSTM1), glucose-6-phosphate dehydrogenase (G6PD), fibroblast growth factor-23 (FGF23), and NLR family pyrin domain containing 3 (NLRP3). Methods. Reverse transcription quantitative polymerase chain reaction (RT-qPCR) was carried out for the selected populations: CKDu patients (n = 43), chronic kidney disease patients (CKD; n = 14), healthy individuals from a CKDu endemic area (GHI; n = 9), and nonendemic area (KHI; n = 16). Fold changes were quantified relative to KHI. Results. GCLC had greater than threefold upregulation in all three study groups, with a maximum of 7.27-fold upregulation in GHI (p = 0.000). GSTM1 was not expressed in 25.6% of CKDu and 42.9% of CKD patients, but CKDu patients expressing GSTM1 showed upregulation of 2.60-fold (p < 0.05). Upregulation of FGF23 and NLRP3 genes in CKD and CKDu was observed (p < 0.01), with greater fold changes in CKD. Conclusion. Results suggest higher influence of external sources of oxidative stress in CKDu, possibly owing to environmental conditions.

  17. The chloroplast membrane associated ceQORH putative quinone oxidoreductase reduces long-chain, stress-related oxidized lipids.

    PubMed

    Curien, Gilles; Giustini, Cécile; Montillet, Jean-Luc; Mas-Y-Mas, Sarah; Cobessi, David; Ferrer, Jean-Luc; Matringe, Michel; Grechkin, Alexander; Rolland, Norbert

    2016-02-01

    Under oxidative stress conditions the lipid constituents of cells can undergo oxidation whose frequent consequence is the production of highly reactive α,β-unsaturated carbonyls. These molecules are toxic because they can add to biomolecules (such as proteins and nucleic acids) and several enzyme activities cooperate to eliminate these reactive electrophile species. CeQORH (chloroplast envelope Quinone Oxidoreductase Homolog, At4g13010) is associated with the inner membrane of the chloroplast envelope and imported into the organelle by an alternative import pathway. In the present study, we show that the recombinant ceQORH exhibits the activity of a NADPH-dependent α,β-unsaturated oxoene reductase reducing the double bond of medium-chain (C⩾9) to long-chain (18 carbon atoms) reactive electrophile species deriving from poly-unsaturated fatty acid peroxides. The best substrates of ceQORH are 13-lipoxygenase-derived γ-ketols. γ-Ketols are spontaneously produced in the chloroplast from the unstable allene oxide formed in the biochemical pathway leading to 12-oxo-phytodienoic acid, a precursor of the defense hormone jasmonate. In chloroplasts, ceQORH could detoxify 13-lipoxygenase-derived γ-ketols at their production sites in the membranes. This finding opens new routes toward the understanding of γ-ketols role and detoxification.

  18. Mitochondrial Oxidative Damage in Aging and Alzheimer's Disease: Implications for Mitochondrially Targeted Antioxidant Therapeutics

    PubMed Central

    Reddy, P. Hemachandra

    2006-01-01

    The overall aim of this article is to review current therapeutic strategies for treating AD, with a focus on mitochondrially targeted antioxidant treatments. Recent advances in molecular, cellular, and animal model studies of AD have revealed that amyloid precursor protein derivatives, including amyloid beta (Aβ) monomers and oligomers, are likely key factors in tau hyperphosphorylation, mitochondrial oxidative damage, inflammatory changes, and synaptic failure in the brain tissue of AD patients. Several therapeutic strategies have been developed to treat AD, including anti-inflammatory, antioxidant, and antiamyloid approaches. Among these, mitochondrial antioxidant therapy has been found to be the most efficacious in reducing pathological changes and in not producing adverse effects; thus, mitochondrial antioxidant therapy is promising as a treatment for AD patients. However, a major limitation in applying mitochondrial antioxidants to AD treatment has been the inability of researchers to enhance antioxidant levels in mitochondria. Recently, however, there has been a breakthrough. Researchers have recently been able to promote the entry of certain antioxidants—including MitoQ, MitoVitE, MitoPBN, MitoPeroxidase, and amino acid and peptide-based SS tetrapeptides—into mitochondria, several hundred-fold more than do natural antioxidants. Once in the mitochondria, they rapidly neutralize free radicals and decrease mitochondrial toxicity. Thus, mitochondrially targeted antioxidants are promising candidates for treating AD patients. PMID:17047303

  19. A positive correlation between mercury and oxidative stress-related gene expression (GPX3 and GSTM3) is measured in female Double-crested Cormorant blood.

    PubMed

    Gibson, Laura A; Lavoie, Raphael A; Bissegger, Sonja; Campbell, Linda M; Langlois, Valerie S

    2014-08-01

    Mercury (Hg) is a widespread contaminant that has been shown to induce a wide range of adverse health effects in birds including reproductive, physiological and neurological impairments. Here we explored the relationship between blood total Hg concentrations ([THg]) and oxidative stress gene induction in the aquatic piscivorous Double-crested Cormorants (Phalacrocorax auritus) using a non-lethal technique, i.e., blood gene expression analysis. P. auritus blood was sampled at five sites across the Great Lakes basin, Ontario, Canada and was analyzed for [THg]. To assess cellular stress, the expression of glutathione peroxidases 1 and 3 (GPX1, GPX3), superoxide dismutase 1 (SOD1), heat-shock protein 70 kd-8 (HSP70-8) and glutathione S-transferase µ3 (GSTM3) were measured in whole blood samples using real-time RT-PCR. Results showed a significantly positive correlation between female blood [THg] and both GPX3 and GSTM3 expression. Different levels of oxidative stress experienced by males and females during the breeding season may be influencing the differential oxidative stress responses to blood [THg] observed in this study. Overall, these results suggest that Hg may lead to oxidative stress as some of the cellular stress-related genes were altered in the blood of female P. auritus and that blood gene expression analysis is a successful approach to assess bird health condition.

  20. Exercise and diet-induced weight loss attenuates oxidative stress related-coronary vasoconstriction in obese adolescents.

    PubMed

    Gao, Zhaohui; Novick, Marsha; Muller, Matthew D; Williams, Ronald J; Spilk, Samson; Leuenberger, Urs A; Sinoway, Lawrence I

    2013-02-01

    Obesity is a disease of oxidative stress (OS). Acute hyperoxia (breathing 100 % O(2)) can evoke coronary vasoconstriction by the oxidative quenching of nitric oxide (NO). To examine if weight loss would alter the hyperoxia-related coronary constriction seen in obese adolescents, we measured the coronary blood flow velocity (CBV) response to hyperoxia using transthoracic Doppler echocardiography before and after a 4-week diet and exercise regimen in 6 obese male adolescents (age 13-17 years, BMI 36.5 ± 2.3 kg/m(2)). Six controls of similar age and BMI were also studied. The intervention group lost 9 ± 1 % body weight, which was associated with a reduced resting heart rate (HR), reduced diastolic blood pressure (BP), and reduced RPP (all P < 0.05). Before weight loss, hyperoxia reduced CBV by 33 ± 3 %. After weight loss, CBV only fell by 15 ± 3 % (P < 0.05). In the control group, CBV responses to hyperoxia were unchanged during the two trials. Thus weight loss: (1) reduces HR, BP, and RPP; and (2) attenuates the OS-related coronary constrictor response seen in obese adolescents. We postulate that: (1) the high RPP before weight loss led to higher myocardial O(2) consumption, higher coronary flow and greater NO production, and in turn a large constrictor response to hyperoxia; and (2) weight loss decreased myocardial oxygen demand and NO levels. Under these circumstances, hyperoxia-induced vasoconstriction was attenuated.

  1. Oxidative stress and mitochondrial damage in coronary artery bypass graft surgery: effects of antioxidant treatments.

    PubMed

    Milei, J; Ferreira, R; Grana, D R; Boveris, A

    2001-01-01

    We examined antioxidant actions in 73 patients undergoing coronary artery surgery by assessing mitochondrial damage and oxidative stress in ventricular biopsies obtained at preischemia and postreperfusion. Those patients who received antioxidant therapy benefited by less oxidative stress and mitochondrial damage.

  2. Sirt3 Protects Dopaminergic Neurons from Mitochondrial Oxidative Stress.

    PubMed

    Shi, Han; Deng, Han-Xiang; Gius, David; Schumacker, Paul T; James Surmeier, D; Ma, Yong-Chao

    2017-03-24

    Age-dependent elevation in mitochondrial oxidative stress is widely posited to be a major factor underlying the loss of substantia nigra pars compacta (SNc) dopaminergic neurons in Parkinson's disease (PD). However, mechanistic links between aging and oxidative stress are not well understood. Sirtuin-3 (Sirt3) is a mitochondrial deacetylase that could mediate this connection. Indeed, genetic deletion of Sirt3 increased oxidative stress and decreased the membrane potential of mitochondria in SNc dopaminergic neurons. This change was attributable to increased acetylation and decreased activity of manganese superoxide dismutase (MnSOD). Site directed mutagenesis of lysine 68 to glutamine (K68Q), mimicking acetylation, decreased MnSOD activity in SNc dopaminergic neurons, whereas mutagenesis of lysine 68 to arginine (K68R), mimicking deacetylation, increased activity. Introduction of K68R MnSOD rescued mitochondrial redox status and membrane potential of SNc dopaminergic neurons from Sirt3 knockouts. Moreover, deletion of DJ-1, which helps orchestrate nuclear oxidant defenses, and Sirt3 in mice led to a clear age-related loss of SNc dopaminergic neurons. Lastly, K68 acetylation of MnSOD was significantly increased in the SNc of PD patients. Taken together, our studies suggest that an age-related decline in Sirt3 protective function is a major factor underlying increasing mitochondrial oxidative stress and loss of SNc dopaminergic neurons in PD.

  3. Mitochondrial dysfunction, oxidative stress, and major depressive disorder

    PubMed Central

    Tobe, Edward H

    2013-01-01

    There is controversy about depression being a physical illness, in part because a reproducible, sensitive, and specific biologic marker is not available. However, there is evidence that mitochondrial dysfunction and oxidative stress may be associated with abnormal brain function and mood disorders, such as depression. This paper reviews selected human and animal studies providing evidence that intracellular mitochondrial metabolic dysfunction in specific brain regions is associated with major depressive disorder. This supports the hypothesis that chronic mitochondrial dysfunction in specific tissues may be associated with depression. Evaluation of mitochondrial dysfunction in specific tissues may broaden the perspective of depression beyond theories about neurotransmitters or receptor sites, and may explain the persistent signs and symptoms of depression. PMID:23650447

  4. Clinical Implications Associated With the Posttranslational Modification-Induced Functional Impairment of Albumin in Oxidative Stress-Related Diseases.

    PubMed

    Watanabe, Hiroshi; Imafuku, Tadashi; Otagiri, Masaki; Maruyama, Toru

    2017-09-01

    Recent research findings indicate that the posttranslational modification of human serum albumin (HSA) such as oxidation, glycation, truncation, dimerization, and carbamylation is related to certain types of diseases. We report herein on a simple and rapid analytical method, using an electrospray ionization time-of-flight mass spectrometry technique, that allows posttranslational modifications of HSA to be quantitatively and qualitatively evaluated with a high degree of sensitivity. In patients with chronic liver disease, chronic renal disease, and diabetes mellitus, an increase in the level of oxidized cysteine-34 (Cys-34) of HSA accompanied by a decrease in the level of reduced Cys-34 was observed. The redox status of Cys-34 was correlated with ligand binding and the antioxidative functions of HSA. Available evidence indicates that monitoring the redox state of Cys-34 not only could be a useful marker for evaluating the progression of disease and its complications but also would permit therapeutic efficacy to be predicted. The redox state of Cys-34 was also used as an index of the quality of HSA preparations. These data suggest that monitoring the posttranslational modifications of HSA can be important, because the function of HSA is related not only to its serum concentration but also to the preservation of its structural integrity under disease conditions. Copyright © 2017. Published by Elsevier Inc.

  5. Oxidative stress related to chlorpyrifos exposure in rainbow trout: Acute and medium term effects on genetic biomarkers.

    PubMed

    Benedetto, A; Brizio, P; Squadrone, S; Scanzio, T; Righetti, M; Gasco, L; Prearo, M; Abete, M C

    2016-05-01

    Organophosphates (OPs) are derivatives of phosphoric acid widely used in agriculture as pesticides. Chlorpyrifos (CPF) is an OP that is extremely toxic to aquatic organisms. Rainbow trout (Oncorhynchus mykiss) is considered as a sentinel model species for ecotoxicology assessment in freshwater ecosystems. An exposure study was carried out on rainbow trout to investigate genetic responses to CPF-induced oxidative stress by Real-Time PCR, and to determine the accumulation dynamics of CPF and toxic metabolite chlorpyrifos-oxon (CPF-ox) in edible parts, by HPLC-MS/MS. Among the genes considered to be related to oxidative stress, a significant increase in HSP70 mRNA levels was observed in liver samples up to 14 days after CPF exposure (0.05 mg/L). CPF concentrations in muscle samples reach mean values of 285.25 ng/g within 96 hours of exposure, while CPF-ox concentrations were always under the limit of quantification (LOQ) of the applied method. Our findings lead us to consider HSP70 as a suitable genetic marker in rainbow trout for acute and medium-term monitoring of CPF exposure, complementary to analytical determinations. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Tissue expression analysis of FeMT3, a drought and oxidative stress related metallothionein gene from buckwheat (Fagopyrum esculentum).

    PubMed

    Samardzić, Jelena T; Nikolić, Dragana B; Timotijević, Gordana S; Jovanović, Zivko S; Milisavljević, Mira Đ; Maksimović, Vesna R

    2010-11-01

    Metallothionein type 3 (MT3) expression has previously been detected in leaves, fruits, and developing somatic embryos in different plant species. However, specific tissular and cellular localization of MT3 transcripts have remained unidentified. In this study, in situ RNA-RNA analysis revealed buckwheat metallothionein type 3 (FeMT3) transcript localization in vascular elements, mesophyll and guard cells of leaves, vascular tissue of roots and throughout the whole embryo. Changes in FeMT3 mRNA levels in response to drought and oxidative stress, as well as ROS scavenging abilities of the FeMT3 protein in yeast were also detected, indicating possible involvement of FeMT3 in stress defense and ROS related cellular processes. Copyright © 2010 Elsevier GmbH. All rights reserved.

  7. Impaired mitochondrial fat oxidation induces adaptive remodeling of muscle metabolism.

    PubMed

    Wicks, Shawna E; Vandanmagsar, Bolormaa; Haynie, Kimberly R; Fuller, Scott E; Warfel, Jaycob D; Stephens, Jacqueline M; Wang, Miao; Han, Xianlin; Zhang, Jingying; Noland, Robert C; Mynatt, Randall L

    2015-06-23

    The correlations between intramyocellular lipid (IMCL), decreased fatty acid oxidation (FAO), and insulin resistance have led to the hypothesis that impaired FAO causes accumulation of lipotoxic intermediates that inhibit muscle insulin signaling. Using a skeletal muscle-specific carnitine palmitoyltransferase-1 KO model, we show that prolonged and severe mitochondrial FAO inhibition results in increased carbohydrate utilization, along with reduced physical activity; increased circulating nonesterified fatty acids; and increased IMCLs, diacylglycerols, and ceramides. Perhaps more importantly, inhibition of mitochondrial FAO also initiates a local, adaptive response in muscle that invokes mitochondrial biogenesis, compensatory peroxisomal fat oxidation, and amino acid catabolism. Loss of its major fuel source (lipid) induces an energy deprivation response in muscle coordinated by signaling through AMP-activated protein kinase (AMPK) and peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC1α) to maintain energy supply for locomotion and survival. At the whole-body level, these adaptations result in resistance to obesity.

  8. Impaired mitochondrial fat oxidation induces adaptive remodeling of muscle metabolism

    PubMed Central

    Wicks, Shawna E.; Vandanmagsar, Bolormaa; Haynie, Kimberly R.; Fuller, Scott E.; Warfel, Jaycob D.; Stephens, Jacqueline M.; Wang, Miao; Han, Xianlin; Zhang, Jingying; Noland, Robert C.; Mynatt, Randall L.

    2015-01-01

    The correlations between intramyocellular lipid (IMCL), decreased fatty acid oxidation (FAO), and insulin resistance have led to the hypothesis that impaired FAO causes accumulation of lipotoxic intermediates that inhibit muscle insulin signaling. Using a skeletal muscle-specific carnitine palmitoyltransferase-1 KO model, we show that prolonged and severe mitochondrial FAO inhibition results in increased carbohydrate utilization, along with reduced physical activity; increased circulating nonesterified fatty acids; and increased IMCLs, diacylglycerols, and ceramides. Perhaps more importantly, inhibition of mitochondrial FAO also initiates a local, adaptive response in muscle that invokes mitochondrial biogenesis, compensatory peroxisomal fat oxidation, and amino acid catabolism. Loss of its major fuel source (lipid) induces an energy deprivation response in muscle coordinated by signaling through AMP-activated protein kinase (AMPK) and peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC1α) to maintain energy supply for locomotion and survival. At the whole-body level, these adaptations result in resistance to obesity. PMID:26056297

  9. Characterization of UPF peptides, members of the glutathione analogues library, on the basis of their effects on oxidative stress-related enzymes.

    PubMed

    Ehrlich, Kersti; Ida, Katrin; Mahlapuu, Riina; Kairane, Ceslava; Oit, Ingrid; Zilmer, Mihkel; Soomets, Ursel

    2009-06-01

    Previously the authors have designed and synthesized a library of antioxidative glutathione analogues called UPF peptides which are superior to glutathione in hydroxyl radical elimination. This paper is a follow-up study which investigated the effects of the most promising members of the library (UPF1 and UPF17) on oxidative stress-related enzymes. At concentrations used in vivo experiments neither UPF peptide influenced the activity of glutathione peroxidase (GPx) when purified enzyme or erythrocyte lysate was used. At higher concentrations they inhibited GPx activity. UPF peptides had no effect on glutathione reductase (GR) activity. Also they, as well as glutathione itself, slightly increased MnSOD activity in human brain mitochondria and inhibited oxidative burst caused by neutrophil NAD(P)H oxidase. RT-PCR measurements showed that UPF1 and UPF17 have no effect on GPx and MnSOD expression level in human blood mononuclear cells. The results of this study confirm that investigated UPF peptides do not interfere with the enzymatic mechanisms of antioxidative defence and can be used as themselves or as a lead for the protector molecule design against excessive oxidative stress.

  10. A novel locus in the oxidative stress-related gene ALOX12 moderates the association between PTSD and thickness of the prefrontal cortex

    PubMed Central

    Miller, Mark W.; Wolf, Erika J.; Sadeh, Naomi; Logue, Mark; Spielberg, Jeffrey M.; Hayes, Jasmeet P.; Sperbeck, Emily; Schichman, Steven A.; Stone, Angie; Carter, Weleetka C.; Humphries, Donald E.; Milberg, William; McGlinchey, Regina

    2015-01-01

    Oxidative stress has been implicated in many common age-related diseases and is hypothesized to play a role in posttraumatic stress disorder (PTSD)-related neurodegeneration (Miller and Sadeh, 2014). This study examined the influence of the oxidative stress-related genes ALOX 12 and ALOX 15 on the association between PTSD and cortical thickness. Factor analyses were used to identify and compare alternative models of the structure of cortical thickness in a sample of 218 veterans. The best-fitting model was then used for a genetic association analysis in White non-Hispanic participants (n = 146) that examined relationships between 33 single nucleotide polymorphisms (SNPs) spanning the two genes, 8 cortical thickness factors, and each SNP × PTSD interaction. Results identified a novel ALOX12 locus (indicated by two SNPs in perfect linkage disequilibrium: rs1042357 and rs10852889) that moderated the association between PTSD and reduced thickness of the right prefrontal cortex. A whole-cortex vertex-wise analysis showed this effect to be localized to clusters spanning the rostral middle frontal gyrus, superior frontal gyrus, rostral anterior cingulated cortex, and medial orbitofrontal cortex. These findings illustrate a novel factor-analytic approach to neuroimaging-genetic analyses and provide new evidence for the possible involvement of oxidative stress in PTSD-related neurodegeneration. PMID:26372769

  11. Oxidative stress and mitochondrial dysfunction-linked neurodegenerative disorders.

    PubMed

    Islam, Md Torequl

    2017-01-01

    Reactive species play an important role in physiological functions. Overproduction of reactive species, notably reactive oxygen (ROS) and nitrogen (RNS) species along with the failure of balance by the body's antioxidant enzyme systems results in destruction of cellular structures, lipids, proteins, and genetic materials such as DNA and RNA. Moreover, the effects of reactive species on mitochondria and their metabolic processes eventually cause a rise in ROS/RNS levels, leading to oxidation of mitochondrial proteins, lipids, and DNA. Oxidative stress has been considered to be linked to the etiology of many diseases, including neurodegenerative diseases (NDDs) such as Alzheimer diseases, Amyotrophic lateral sclerosis, Friedreich's ataxia, Huntington's disease, Multiple sclerosis, and Parkinson's diseases. In addition, oxidative stress causing protein misfold may turn to other NDDs include Creutzfeldt-Jakob disease, Bovine Spongiform Encephalopathy, Kuru, Gerstmann-Straussler-Scheinker syndrome, and Fatal Familial Insomnia. An overview of the oxidative stress and mitochondrial dysfunction-linked NDDs has been summarized in this review.

  12. A mitochondrial enzyme degrades carotenoids and protects against oxidative stress.

    PubMed

    Amengual, Jaume; Lobo, Glenn P; Golczak, Marcin; Li, Hua Nan M; Klimova, Tatyana; Hoppel, Charles L; Wyss, Adrian; Palczewski, Krzysztof; von Lintig, Johannes

    2011-03-01

    Carotenoids are the precursors for vitamin A and are proposed to prevent oxidative damage to cells. Mammalian genomes encode a family of structurally related nonheme iron oxygenases that modify double bonds of these compounds by oxidative cleavage and cis-to-trans isomerization. The roles of the family members BCMO1 and RPE65 for vitamin A production and vision have been well established. Surprisingly, we found that the third family member, β,β-carotene-9',10'-oxygenase (BCDO2), is a mitochondrial carotenoid-oxygenase with broad substrate specificity. In BCDO2-deficient mice, carotenoid homeostasis was abrogated, and carotenoids accumulated in several tissues. In hepatic mitochondria, accumulated carotenoids induced key markers of mitochondrial dysfunction, such as manganese superoxide dismutase (9-fold), and reduced rates of ADP-dependent respiration by 30%. This impairment was associated with an 8- to 9-fold induction of phosphor-MAP kinase and phosphor-AKT, markers of cell signaling pathways related to oxidative stress and disease. Administration of carotenoids to human HepG2 cells depolarized mitochondrial membranes and resulted in the production of reactive oxygen species. Thus, our studies in BCDO2-deficient mice and human cell cultures indicate that carotenoids can impair respiration and induce oxidative stress. Mammalian cells thus express a mitochondrial carotenoid-oxygenase that degrades carotenoids to protect these vital organelles.

  13. A mitochondrial enzyme degrades carotenoids and protects against oxidative stress

    PubMed Central

    Amengual, Jaume; Lobo, Glenn P.; Golczak, Marcin; Li, Hua Nan M.; Klimova, Tatyana; Hoppel, Charles L.; Wyss, Adrian; Palczewski, Krzysztof; von Lintig, Johannes

    2011-01-01

    Carotenoids are the precursors for vitamin A and are proposed to prevent oxidative damage to cells. Mammalian genomes encode a family of structurally related nonheme iron oxygenases that modify double bonds of these compounds by oxidative cleavage and cis-to-trans isomerization. The roles of the family members BCMO1 and RPE65 for vitamin A production and vision have been well established. Surprisingly, we found that the third family member, β,β-carotene-9′,10′-oxygenase (BCDO2), is a mitochondrial carotenoid-oxygenase with broad substrate specificity. In BCDO2-deficient mice, carotenoid homeostasis was abrogated, and carotenoids accumulated in several tissues. In hepatic mitochondria, accumulated carotenoids induced key markers of mitochondrial dysfunction, such as manganese superoxide dismutase (9-fold), and reduced rates of ADP-dependent respiration by 30%. This impairment was associated with an 8- to 9-fold induction of phosphor-MAP kinase and phosphor-AKT, markers of cell signaling pathways related to oxidative stress and disease. Administration of carotenoids to human HepG2 cells depolarized mitochondrial membranes and resulted in the production of reactive oxygen species. Thus, our studies in BCDO2-deficient mice and human cell cultures indicate that carotenoids can impair respiration and induce oxidative stress. Mammalian cells thus express a mitochondrial carotenoid-oxygenase that degrades carotenoids to protect these vital organelles.—Amengual, J., Lobo, G. P., Golczak, M., Li, H. N. M., Klimova, T., Hoppel, C. L., Wyss, A., Palczewski, K., von Lintig, J. A mitochondrial enzyme degrades carotenoids and protects against oxidative stress. PMID:21106934

  14. Mitochondrial oxidative stress and dysfunction in arsenic neurotoxicity: A review.

    PubMed

    Prakash, Chandra; Soni, Manisha; Kumar, Vijay

    2016-02-01

    Arsenic is a toxic metalloid present ubiquitously on earth. Since the last decade, it has gained considerable attention due to its severe neurotoxic effects. Arsenic can cross the blood-brain barrier and accumulate in different regions of the brain suggesting its role in neurological diseases. Arsenic exposure has been associated with reactive oxygen species generation, which is supposed to be one of the mechanisms of arsenic-induced oxidative stress. Mitochondria, being the major source of reactive oxygen species generation may present an important target of arsenic toxicity. It is speculated that the proper functioning of the brain depends largely on efficient mitochondrial functions. Multiple studies have reported evidence of brain mitochondrial impairment after arsenic exposure. In this review, we have evaluated the proposed mechanisms of arsenic-induced mitochondrial oxidative stress and dysfunction. The understanding of molecular mechanism of mitochondrial dysfunction may be helpful to develop therapeutic strategies against arsenic-induced neurotoxicity. The ameliorative measures undertaken in arsenic-induced mitochondrial dysfunction have also been highlighted. Copyright © 2015 John Wiley & Sons, Ltd.

  15. Mitochondrial-Nuclear Communication by Prohibitin Shuttling Under Oxidative Stress

    PubMed Central

    Sripathi, Srinivas; He, Weilue; Atkinson, Cameron; Smith, Joey; Liu, Zhicong; Elledge, Beth; Jahng, Wan Jin

    2017-01-01

    Mitochondrial-nuclear communication is critical to maintain mitochondrial activity under stress conditions. Adaptation of the mitochondria-nucleus network to changes in the intracellular oxidation and reduction milieu is critical for the survival of retinal and retinal pigment epithelial (RPE) cells, in relation to their high oxygen demand and rapid metabolism. However, the generation and transmittal of mitochondrial signal to the nucleus remains elusive. Previously, our in vivo study revealed that prohibitin is up-regulated in the retina but is down-regulated in RPE in the aging and diabetic model. In this study, the functional role of prohibitin in the retina and the RPE was studied using biochemical methods, including lipid binding assay, 2D gel electrophoresis, immunocytochemistry, Western blot, and knockdown approach. Protein depletion by siRNA characterized prohibitin as an anti-apoptotic molecule in mitochondria, while lipid binding assay demonstrated subcellular communications between mitochondria and the nucleus under oxidative stress. The changes of the expressions and localization of mitochondrial prohibitin triggered by reactive oxygen species are crucial for mitochondrial integrity. We propose that prohibitin shuttles between mitochondria and the nucleus as an anti-apoptotic molecule and a transcriptional regulator under stress environment in the retina and RPE. PMID:21879722

  16. Mitochondrial biology and oxidative stress in Parkinson disease pathogenesis.

    PubMed

    Henchcliffe, Claire; Beal, M Flint

    2008-11-01

    Parkinson disease (PD) is associated with progressive loss of dopaminergic neurons in the substantia nigra, as well as with more-widespread neuronal changes that cause complex and variable motor and nonmotor symptoms. Recent rapid advances in PD genetics have revealed a prominent role for mitochondrial dysfunction in the pathogenesis of the disease, and the products of several PD-associated genes, including SNCA, Parkin, PINK1, DJ-1, LRRK2 and HTR2A, show a degree of localization to the mitochondria under certain conditions. Impaired mitochondrial function is likely to increase oxidative stress and might render cells more vulnerable to this and other related processes, including excitotoxicity. The mitochondria, therefore, represent a highly promising target for the development of disease biomarkers by use of genetic, biochemical and bioimaging approaches. Novel therapeutic interventions that modify mitochondrial function are currently under development, and a large phase III clinical trial is underway to examine whether high-dose oral coenzyme Q10 will slow disease progression. In this Review, we examine evidence for the roles of mitochondrial dysfunction and increased oxidative stress in the neuronal loss that leads to PD and discuss how this knowledge might further improve patient management and aid in the development of 'mitochondrial therapy' for PD.

  17. Mitochondrial dysfunction associated with nitric oxide pathways in glutamate neurotoxicity.

    PubMed

    Manucha, Walter

    Multiple mechanisms underlying glutamate-induced neurotoxicity have recently been discussed. Likewise, a clear deregulation of the mitochondrial respiratory mechanism has been described in patients with neurodegeneration, oxidative stress, and inflammation. This article highlights nitric oxide, an atypical neurotransmitter synthesized and released on demand by the post-synaptic neurons, and has many important implications for nerve cell survival and differentiation. Consequently, synaptogenesis, synapse elimination, and neurotransmitter release, are nitric oxide-modulated. Interesting, an emergent role of nitric oxide pathways has been discussed as regards neurotoxicity from glutamate-induced apoptosis. These findings suggest that nitric oxide pathways modulation could prevent oxidative damage to neurons through apoptosis inhibition. This review aims to highlight the emergent aspects of nitric oxide-mediated signaling in the brain, and how they can be related to neurotoxicity, as well as the development of neurodegenerative diseases development.

  18. PEDF improves mitochondrial function in RPE cells during oxidative stress.

    PubMed

    He, Yuan; Leung, Kar Wah; Ren, Yuan; Pei, Jinzhi; Ge, Jian; Tombran-Tink, Joyce

    2014-09-11

    Oxidative stress plays an important role in health and aging. We have shown that oxidative stress impairs mitochondrial function and promotes RPE cell death in an age-dependent manner. This study investigates the role of pigment epithelium-derived factor (PEDF) in limiting oxidative stress-induced damage to RPE cells through mitochondrial pathways. Three groups of early-passaged RPE cells from donors 50 to 55, 60 to 65, and 70 to 75 years old (yo) were either preconditioned with PEDF followed by exposure to sublethal doses of hydrogen peroxide (H2O2) or post-treated with PEDF after H2O2 treatment. Effects of PEDF on mitochondrial function and cell viability were examined. Oxidative stress induced an age-dependent increase in LDH release, reactive oxygen species (ROS) levels, and cell death and a decrease in adenosine triphosphate (ATP) production and mitochondrial membrane potential (ΔΨm) in human RPE cells. Preconditioning or poststressed treatment with PEDF resulted in increased cell viability, inhibition of cytochrome c release and caspase 3 cleavage, and improved mitochondria function denoted by a decrease in ROS generation and increases in ATP production and ΔΨm. Oxidative stress also disrupted the reticular network, trafficking, and distribution of the mitochondria and blocked activation of phosphatidylinositol 3 kinase (PI3K), Akt, and Erk signaling in the cells. These effects were more pronounced in RPE cells from individuals>60 yo compared to the 50 to 55 yo age group. Pigment epithelium-derived factor mitigated negative effects of oxidative stress on mitochondrial remodeling and cellular distribution and unblocked its control of PI3K/Akt and mitogen-activated protein kinase (MAPK) signaling. Although PEDF potentiated both PI3K/Akt and MAPK signaling in the cells, stabilization of mitochondrial networks and function was dependent on its activation of PI3K/Akt. Specificity of PEDF's activity was confirmed using the pharmacological inhibitors LY294002

  19. Tat-HSP22 inhibits oxidative stress-induced hippocampal neuronal cell death by regulation of the mitochondrial pathway.

    PubMed

    Jo, Hyo Sang; Kim, Dae Won; Shin, Min Jea; Cho, Su Bin; Park, Jung Hwan; Lee, Chi Hern; Yeo, Eun Ji; Choi, Yeon Joo; Yeo, Hyeon Ji; Sohn, Eun Jeong; Son, Ora; Cho, Sung-Woo; Kim, Duk-Soo; Yu, Yeon Hee; Lee, Keun Wook; Park, Jinseu; Eum, Won Sik; Choi, Soo Young

    2017-01-04

    Oxidative stress plays an important role in the progression of various neuronal diseases including ischemia. Heat shock protein 22 (HSP22) is known to protect cells against oxidative stress. However, the protective effects and mechanisms of HSP22 in hippocampal neuronal cells under oxidative stress remain unknown. In this study, we determined whether HSP22 protects against hydrogen peroxide (H2O2)-induced oxidative stress in HT-22 using Tat-HSP22 fusion protein. We found that Tat-HSP22 transduced into HT-22 cells and that H2O2-induced cell death, oxidative stress, and DNA damage were significantly reduced by Tat-HSP22. In addition, Tat-HSP22 markedly inhibited H2O2-induced mitochondrial membrane potential, cytochrome c release, cleaved caspase-3, and Bax expression levels, while Bcl-2 expression levels were increased in HT-22 cells. Further, we showed that Tat-HSP22 transduced into animal brain and inhibited cleaved-caspase-3 expression levels as well as significantly inhibited hippocampal neuronal cell death in the CA1 region of animals in the ischemic animal model. In the present study, we demonstrated that transduced Tat-HSP22 attenuates oxidative stress-induced hippocampal neuronal cell death through the mitochondrial signaling pathway and plays a crucial role in inhibiting neuronal cell death, suggesting that Tat-HSP22 protein may be used to prevent oxidative stress-related brain diseases including ischemia.

  20. High-sensitive C-reactive protein level and oxidative stress-related status in former athletes in relation to traditional cardiovascular risk factors.

    PubMed

    Pihl, E; Zilmer, K; Kullisaar, T; Kairane, C; Pulges, A; Zilmer, M

    2003-12-01

    To analyze systemic and cellular oxidative stress-related indices as well as C-reactive protein level in former top-level athletes in relation to traditional cardiovascular risk factors. A cross-sectional study was performed in 53 former male athletes and 25 sedentary controls (age range: 39-59 years). We measured anthropometric factors (BMI, fat percentage, WHR), resting blood pressure (SBP, DBP), serum cholesterol (CHOL), high-density lipoprotein-cholesterol (HDL-C), low-density lipoprotein-cholesterol (LDL-C), triglycerides (TG), total antioxidant status (TAS), oxidized LDL-C (oxLDL), diene conjugates (DC), glutathione redox status, high-sensitive C-reactive protein (hsCRP), and leisure-time physical activity. Physically active former athletes had significantly lower mean overweight (BMI, fat percentage, WHR), better spectrum of atherogenesis indicators (CHOL, HDL-C, TG, TG:HDL-C ratio) and lower oxidative stress (oxLDL, oxLDL:LDL-C ratio, DC) values than sedentary ex-athletes. No significant differences in these variables were found between the sedentary ex-athletes and control group. Significant associations were found between physical activity (METs), SBP, DBP, hypertension, CHOL, HDL-C, TG, TG:HDL-C ratio, oxLDL, oxLDL:LDL-C ratio, DC and hsCRP. A physically active lifestyle is related to a lower cardiovascular disease (CVD) risk profile including a substantially lower systemic and cellular oxidative stress status as well as C-reactive protein level in middle-aged men. Copyright 2003 Elsevier Ireland Ltd.

  1. Mitochondrial dysfunction and oxidative damage in parkin-deficient mice.

    PubMed

    Palacino, James J; Sagi, Dijana; Goldberg, Matthew S; Krauss, Stefan; Motz, Claudia; Wacker, Maik; Klose, Joachim; Shen, Jie

    2004-04-30

    Loss-of-function mutations in parkin are the predominant cause of familial Parkinson's disease. We previously reported that parkin-/- mice exhibit nigrostriatal deficits in the absence of nigral degeneration. Parkin has been shown to function as an E3 ubiquitin ligase. Loss of parkin function, therefore, has been hypothesized to cause nigral degeneration via an aberrant accumulation of its substrates. Here we employed a proteomic approach to determine whether loss of parkin function results in alterations in abundance and/or modification of proteins in the ventral midbrain of parkin-/- mice. Two-dimensional gel electrophoresis followed by mass spectrometry revealed decreased abundance of a number of proteins involved in mitochondrial function or oxidative stress. Consistent with reductions in several subunits of complexes I and IV, functional assays showed reductions in respiratory capacity of striatal mitochondria isolated from parkin-/- mice. Electron microscopic analysis revealed no gross morphological abnormalities in striatal mitochondria of parkin-/- mice. In addition, parkin-/- mice showed a delayed rate of weight gain, suggesting broader metabolic abnormalities. Accompanying these deficits in mitochondrial function, parkin-/- mice also exhibited decreased levels of proteins involved in protection from oxidative stress. Consistent with these findings, parkin-/- mice showed decreased serum antioxidant capacity and increased protein and lipid peroxidation. The combination of proteomic, genetic, and physiological analyses reveal an essential role for parkin in the regulation of mitochondrial function and provide the first direct evidence of mitochondrial dysfunction and oxidative damage in the absence of nigral degeneration in a genetic mouse model of Parkinson's disease.

  2. Mitochondrial nitric oxide metabolism in rat muscle during endotoxemia.

    PubMed

    Alvarez, Silvia; Boveris, Alberto

    2004-11-01

    In this study, heart and diaphragm mitochondria produced 0.69 and 0.77 nmol nitric oxide (NO)/min mg protein, rates that account for 67 and 24% of maximal cellular NO production, respectively. Endotoxemia and septic shock occur with an exacerbated inflammatory response that damages tissue mitochondria. Skeletal muscle seems to be one of the main target organs in septic shock, showing an increased NO production and early oxidative stress. The kinetic properties of mitochondrial nitric oxide synthase (mtNOS) of heart and diaphragm were determined. For diaphragm, the KM values for O2 and L-Arg were 4.6 and 37 microM and for heart were 3.3 and 36 microM. The optimal pH for mtNOS activity was 6.5 for diaphragm and 7.0 for heart. A marked increase in mtNOS activity was observed in endotoxemic rats, 90% in diaphragm and 30% in heart. Diaphragm and heart mitochondrial O2*- and H2O2 production were 2- to 3-fold increased during endotoxemia and Mn-SOD activity showed a 2-fold increase in treated animals, whereas catalase activity was unchanged. One of the current hypotheses for the molecular mechanisms underlying the complex condition of septic shock is that the enhanced NO production by mtNOS leads to excessive peroxynitrite production and protein nitration in the mitochondrial matrix, causing mitochondrial dysfunction and contractile failure.

  3. Oxidative stress causes reversible changes in mitochondrial permeability and structure

    PubMed Central

    Cole, Nelson B.; Daniels, Mathew P.; Levine, Rodney L.; Kim, Geumsoo

    2010-01-01

    Mitochondria are a primary source as well a principal target of reactive oxygen species within cells. Using immunofluorescence microscopy, we have found that a number of mitochondrial matrix proteins are normally undetectable in formaldehyde fixed cells permeabilized with the cholesterol-binding detergent saponin. However, exogenous or endogenous oxidative stress applied prior to fixation altered the permeability of mitochondria, rendering these matrix proteins accessible to antibodies. Electron microscopy revealed a loss of matrix density and disorganization of inner-membrane cristae upon oxidative stress. Notably, the changes in permeability and in structure were rapidly reversed when the oxidative stress was relieved. The ability of reactive oxygen species to reversibly alter the permeability of the mitochondrial membrane provides a potential mechanism for communication within the cell such as between nucleus and mitochondria. PMID:20096768

  4. Mitochondrial dysfunction and oxidative stress in aging and cancer

    PubMed Central

    Kudryavtseva, Anna V.; Krasnov, George S.; Dmitriev, Alexey A.; Alekseev, Boris Y.; Kardymon, Olga L.; Sadritdinova, Asiya F.; Fedorova, Maria S.; Pokrovsky, Anatoly V.; Melnikova, Nataliya V.; Kaprin, Andrey D.; Moskalev, Alexey A.; Snezhkina, Anastasiya V.

    2016-01-01

    Aging and cancer are the most important issues to research. The population in the world is growing older, and the incidence of cancer increases with age. There is no doubt about the linkage between aging and cancer. However, the molecular mechanisms underlying this association are still unknown. Several lines of evidence suggest that the oxidative stress as a cause and/or consequence of the mitochondrial dysfunction is one of the main drivers of these processes. Increasing ROS levels and products of the oxidative stress, which occur in aging and age-related disorders, were also found in cancer. This review focuses on the similarities between ageing-associated and cancer-associated oxidative stress and mitochondrial dysfunction as their common phenotype. PMID:27270647

  5. Mitochondrial nitric oxide synthase, mitochondrial brain dysfunction in aging, and mitochondria-targeted antioxidants.

    PubMed

    Navarro, Ana; Boveris, Alberto

    2008-01-01

    This paper reviews the current ideas on nitric oxide (NO) physiology in brain and other mammalian organs and on the subcellular distribution of nitric oxide synthases (NOS) emphasizing on the evidence of a mitochondrial NOS isoform (mtNOS) that exhibits a mean activity of 0.86+/-0.09 nmol NO/min x mg protein in 13 mouse and rat organs. Mammalian brain aging is associated with mitochondrial dysfunction, determined as decreased electron transfer and enzymatic activities and as an increased content of phospholipid oxidation products and of protein oxidation/nitration products. Brain mtNOS is the most decreased enzymatic activity upon aging; decreased levels of NO are interpreted as the cause of decreased mitochondrial biogenesis in aged brain. The beneficial effect of high doses of vitamin E on mice survival and neurological function are related to its effect as antioxidant in brain mitochondria and to the preservation of mtNOS activity. Mitochondria-targeted antioxidants, phosphonium cation derivatives and antioxidant tetrapeptides, are reviewed in terms of structures and biological effects.

  6. Mitochondrial oxidant stress in locus coeruleus is regulated by activity and nitric oxide synthase

    PubMed Central

    Sanchez–Padilla, J.; Guzman, J.N.; Ilijic, E.; Kondapalli, J.; Galtieri, D.J.; Yang, B.; Schieber, S.; Oertel, W.; Wokosin, D.; Schumacker, P. T.; Surmeier, D. J.

    2014-01-01

    Summary Loss of noradrenergic locus coeruleus (LC) neurons is a prominent feature of aging–related neurodegenerative diseases, like Parkinson’s disease (PD). The basis of this vulnerability is not understood. To explore possible physiological determinants, LC neurons were studied using electrophysiological and optical approaches in ex vivo mouse brain slices. These studies revealed that autonomous activity in LC neurons was accompanied by oscillations in dendritic Ca2+ concentration attributable to opening of L–type Ca2+ channels. This oscillation elevated mitochondrial oxidant stress and was attenuated by inhibition of nitric oxide synthase. The relationship between activity and stress was malleable, as arousal and carbon dioxide, each increased the spike rate, but differentially affected mitochondrial oxidant stress. Oxidant stress also was increased in an animal model of PD. Thus, our results point to activity–dependent Ca2+ entry and a resulting mitochondrial oxidant stress as factors contributing to the vulnerability of LC neurons. PMID:24816140

  7. Exogenous NO depletes Cd-induced toxicity by eliminating oxidative damage, re-establishing ATPase activity, and maintaining stress-related hormone equilibrium in white clover plants.

    PubMed

    Liu, S L; Yang, R J; Pan, Y Z; Wang, M H; Zhao, Y; Wu, M X; Hu, J; Zhang, L L; Ma, M D

    2015-11-01

    Various nitric oxide (NO) regulators [including the NO donor sodium nitroprusside (SNP), the NO scavenger 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (cPTIO), the NO-synthase inhibitor N (G)-nitro-L-Arg-methyl ester (L-NAME), and the SNP analogues sodium nitrite/nitrate and sodium ferrocyanide] were investigated to elucidate the role of NO in white clover (Trifolium repens L.) plants after long-term (5 days) exposure to cadmium (Cd). A dose of 100 μM Cd stress significantly restrained plant growth and decreased the concentrations of chlorophyll and NO in vivo, whereas it disrupted the balance of stress-related hormones and enhanced the accumulation of Cd, thereby inducing reactive oxygen species (ROS) burst. However, the inhibition of plant growth was relieved by 50 μM SNP through its stimulation of ROS-scavenging compounds (ascorbic acid, ascorbate peroxidase, catalase, glutathione reductase, non-protein thiol, superoxide dismutase, and total glutathione), regulation of H(+)-ATPase activity of proton pumps, and increasing jasmonic acid and proline but decreasing ethylene in plant tissues. Even so, the alleviating effect of SNP on plant growth was counteracted by cPTIO and L-NAME and was not observed with SNP analogues, suggesting that the protective roles of SNP are related to the induction of NO. These results suggest that NO may improve the Cd tolerance of white clover plants by eliminating oxidative damage, re-establishing ATPase activity, and maintaining hormone equilibrium. Improving our understanding of the role of NO in white clover plants is key to expanding the plantations to various regions and the recovery of pasture species in the future.

  8. Differential influence of propofol on different cell types in terms of the expression of various oxidative stress-related enzymes in an experimental endotoxemia model.

    PubMed

    Tsai, Yu-Chuan; Huang, Chein-Chi; Chu, Lu-Min; Liu, Yen-Chin

    2012-12-01

    Both overproduction of nitric oxide and oxidative injury to the cardiovascular and pulmonary systems contribute to fatal pathophysiology during endotoxemia. We investigated the effect of propofol on oxidative stress-related enzymes in lung (L2), heart (H9C2) and macrophage (NR8383) cells during endotoxemia. Experimental endotoxemia was induced by co-culture of Escherichia coli lipopolysaccharide (15 μg/mL) in the abovementioned three types of cells that were under the effect of propofol (15 or 30 μM for 1 or 4 hours). Cellular expression of induced nitric oxide synthase (iNOS), superoxide dismutase (SOD) 1 and 2, and p47phox (representing NADPH oxidase) were determined by immunoblotting. The cellular oxidative burst activity was determined using a dihydroethidium method via flow cytometry to represent the level of reactive oxygen species. The in vivo endotoxemia model was also employed for comparison using a systemic injection of lipopolysaccharide (15 mg/kg) under propofol maintenance (15 or 30 mg/kg/h). The Student t test (two groups) was used for statistical evaluation among the means, and the Newman-Keuls test was used for analysis of variance in the statistical analysis. In lung L2 cells, propofol significantly reduced the expression of iNOS, SOD1, SOD2, and p47phox under LPS-induced endotoxemia. However, in H9C2 cardiac cells and NR8383 macrophages, only the expression of iNOS was significantly suppressed, but not that of SOD1, SOD2, or p47phox. The level of reactive oxygen species was suppressed in all three kinds of cell. In in vivo animal tissue, except for the suppression of iNOS expression in lung and heart cells, propofol in lung cells produced only SOD1 suppression, but in rat heart the expression of both SOD1 and SOD2 was suppressed. These results suggest that propofol may have a protective role for lung cells. This effect is associated with its suppression of oxidative-related enzymes, including iNOS, SOD1, SOD2, and p47phox. In cardiac myocytes

  9. Mitochondrial Cyclophilin D in Vascular Oxidative Stress and Hypertension.

    PubMed

    Itani, Hana A; Dikalova, Anna E; McMaster, William G; Nazarewicz, Rafal R; Bikineyeva, Alfiya T; Harrison, David G; Dikalov, Sergey I

    2016-06-01

    Vascular superoxide (O˙2 (-)) and inflammation contribute to hypertension. The mitochondria are an important source of O˙2 (-); however, the regulation of mitochondrial O˙2 (-) and the antihypertensive potential of targeting the mitochondria remain poorly defined. Angiotensin II and inflammatory cytokines, such as interleukin 17A and tumor necrosis factor-α (TNFα) significantly contribute to hypertension. We hypothesized that angiotensin II and cytokines co-operatively induce cyclophilin D (CypD)-dependent mitochondrial O˙2 (-) production in hypertension. We tested whether CypD inhibition attenuates endothelial oxidative stress and reduces hypertension. CypD depletion in CypD(-/-) mice prevents overproduction of mitochondrial O˙2 (-) in angiotensin II-infused mice, attenuates hypertension by 20 mm Hg, and improves vascular relaxation compared with wild-type C57Bl/6J mice. Treatment of hypertensive mice with the specific CypD inhibitor Sanglifehrin A reduces blood pressure by 28 mm Hg, inhibits production of mitochondrial O˙2 (-) by 40%, and improves vascular relaxation. Angiotensin II-induced hypertension was associated with CypD redox activation by S-glutathionylation, and expression of the mitochondria-targeted H2O2 scavenger, catalase, abolished CypD S-glutathionylation, prevented stimulation mitochondrial O˙2 (-), and attenuated hypertension. The functional role of cytokine-angiotensin II interplay was confirmed by co-operative stimulation of mitochondrial O˙2 (-) by 3-fold in cultured endothelial cells and impairment of aortic relaxation incubated with combination of angiotensin II, interleukin 17A, and tumor necrosis factor-α which was prevented by CypD depletion or expression of mitochondria-targeted SOD2 and catalase. These data support a novel role of CypD in hypertension and demonstrate that targeting CypD decreases mitochondrial O˙2 (-), improves vascular relaxation, and reduces hypertension. © 2016 American Heart Association, Inc.

  10. Diseases of the human mitochondrial oxidative phosphorylation system.

    PubMed

    Montoya, Julio; López-Gallardo, Ester; Herrero-Martín, María Dolores; Martínez-Romero, Iñigo; Gómez-Durán, Aurora; Pacheu, David; Carreras, Magdalena; Díez-Sánchez, Carmen; López-Pérez, Manuel J; Ruiz-Pesini, Eduardo

    2009-01-01

    Mitochondrial diseases, or diseases of the oxidative phosphorylation system, consist of a group of disorders originated by a deficient synthesis of ATP. This system is composed of proteins codified in the two genetic systems of the cell, the nuclear and the mitochondrial genomes, and, therefore, the mode of inheritance could be either mendelian or maternal. The diseases can also appear sporadically. Due to the central role that mitochondria play in cellular physiology, these diseases are a social and health problem of great importance. They are considered rare diseases; however, together they constitute a large variety of genetic disorders. It is also believed that mitochondria are involved, directly or indirectly, in many other human diseases, mainly in age-related diseases. This review will focus mainly on describing the special characteristics of the mitochondrial genetic system and the diseases caused by mitochondrial DNA mutations. We will also note the difficulties in studying these pathologies, and the possible involvement of the genetic variability of the mitochondrial genome in the development of these diseases.

  11. Exportability of the mitochondrial oxidative phosphorylation machinery into myelin sheath.

    PubMed

    Morelli, Alessandro; Ravera, Silvia; Calzia, Daniela; Panfoli, Isabella

    2011-01-01

    White matter comprises over half of the brain, and its role in axonal survival is being reconsidered, consistently with the observation that axonal degeneration follows demyelination. The recent evidence of an extra-mitochondrial aerobic ATP production in isolated myelin vesicles, thanks to the expression therein of the mitochondrial Oxydative Phosphorylation (OXPHOS) machinery, stands in for myelin playing a functional bioenergetic role in ATP supply for the axon. The observation that subunits of the OXPHOS encoded by the mitochondrial genome are expressed in myelin, suggests that they can be the same as those of the inner mitochondrial membrane. This would mean that the OXPHOS is exportable. Here the hypothesis is exposed that the mitochondrion is the unique site of the assembly of the OXPHOS, so that this is exported to those sub cellular districts displaying high energy demand, such as myelin sheath. There the OXPHOS would display a higher efficiency in oxidative ATP production than inside the mitochondrion itself In this respect, the role of the glia in the nervous conduction is shed new light and the oligodendrocyte mitochondrial OXPHOS are hypothesized to be delivered to nascent myelin.

  12. Cardioprotective effects of lipoic acid, quercetin and resveratrol on oxidative stress related to thyroid hormone alterations in long-term obesity.

    PubMed

    Cheserek, Maureen Jepkorir; Wu, Guirong; Li, Longnan; Li, Lirong; Karangwa, Eric; Shi, Yonghui; Le, Guowei

    2016-07-01

    This study investigated possible mechanisms for cardioprotective effects of lipoic acid (LA), quercetin (Q) and resveratrol (R) on oxidative stress related to thyroid hormone alterations in long-term obesity. Female C57BL/6 mice were fed on high-fat diet (HFD), HFD+LA, HFD+R, HFD+Q and normal diet for 26weeks. Body weight, blood pressure, thyroid hormones, oxidative stress markers, angiotensin converting enzyme (ACE), nitric oxide synthase (NOS) and ion pump activities were measured, and expression of cardiac genes was analyzed by real-time polymerase chain reaction. HFD induced marked increase (P<.05) in body weight, blood pressure and oxidative stress, while plasma triidothyronine levels reduced. ACE activity increased (P<.05) in HFD mice (0.69±0.225U/mg protein) compared with controls (0.28±0.114U/mg protein), HFD+LA (0.231±0.02U/mg protein) and HFD+Q (0.182±0.096U/mg protein) at 26weeks. Moreover, Na(+)/K(+)-ATPase and Ca(2+)-ATPase activities increased in HFD mice whereas NOS reduced. A 1.5-fold increase in TRα1 and reduction in expression of the deiodinase iodothyronine DIO1, threonine protein kinase and NOS3 as well as up-regulation of AT1α, ACE, ATP1B1, GSK3β and Cja1 genes also occurred in HFD mice. Conversely, LA, Q and R inhibited weight gain; reduced TRα1 expression as well as increased DIO1; reduced ACE activity and AT1α, ATP1B1 and Cja1 gene expression as well as inhibited GSK3β; increased total antioxidant capacity, GSH and catalase activity; and reduced blood pressure. In conclusion, LA, resveratrol and quercetin supplementation reduces obesity thereby restoring plasma thyroid hormone levels and attenuating oxidative stress in the heart and thus may have therapeutic potential in heart diseases. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. Rabies virus phosphoprotein interacts with mitochondrial Complex I and induces mitochondrial dysfunction and oxidative stress.

    PubMed

    Kammouni, Wafa; Wood, Heidi; Saleh, Ali; Appolinario, Camila M; Fernyhough, Paul; Jackson, Alan C

    2015-08-01

    Our previous studies in an experimental model of rabies showed neuronal process degeneration in association with severe clinical disease. Cultured adult rodent dorsal root ganglion neurons infected with challenge virus standard (CVS)-11 strain of rabies virus (RABV) showed axonal swellings and reduced axonal growth with evidence of oxidative stress. We have shown that CVS infection alters a variety of mitochondrial parameters and increases reactive oxygen species (ROS) production and mitochondrial Complex I activity vs. mock infection. We have hypothesized that a RABV protein targets mitochondria and triggers dysfunction. Mitochondrial extracts of mouse neuroblastoma cells were analyzed with a proteomics approach. We have identified peptides belonging to the RABV nucleocapsid protein (N), phosphoprotein (P), and glycoprotein (G), and our data indicate that the extract was most highly enriched with P. P was also detected by immunoblotting in RABV-infected purified mitochondrial extracts and also in Complex I immunoprecipitates from the extracts but not in mock-infected extracts. A plasmid expressing P in cells increased Complex I activity and increased ROS generation, whereas expression of other RABV proteins did not. We have analyzed recombinant plasmids encoding various P gene segments. Expression of a peptide from amino acid 139-172 increased Complex I activity and ROS generation similar to expression of the entire P protein, whereas peptides that did not contain this region did not increase Complex I activity or induce ROS generation. These results indicate that a region of the RABV P interacts with Complex I in mitochondria causing mitochondrial dysfunction, increased generation of ROS, and oxidative stress.

  14. Exercise increases mitochondrial glutamate oxidation in the mouse cerebral cortex.

    PubMed

    Herbst, Eric A F; Holloway, Graham P

    2016-07-01

    The present study investigated the impact of acute exercise on stimulating mitochondrial respiratory function in mouse cerebral cortex. Where pyruvate-stimulated respiration was not affected by acute exercise, glutamate respiration was enhanced following the exercise bout. Additional assessment revealed that this affect was dependent on the presence of malate and did not occur when substituting glutamine for glutamate. As such, our results suggest that glutamate oxidation is enhanced with acute exercise through activation of the malate-aspartate shuttle.

  15. Dietary Supplement Attenuates Radiation-Induced Osteoclastogenic and Oxidative Stress-Related Responses and Protects Adult Mice from Radiation-Induced Bone Loss

    NASA Technical Reports Server (NTRS)

    Globus, Ruth; Schreurs, Ann-Sofie; Tahimic, Candice; Shirazi-Fard, Yasaman; Alwood, Joshua; Shahnazari, Mohammed; Halloran, Bernard

    2015-01-01

    Our central hypothesis is that oxidative stress plays a key role in cell dysfunction and progressive bone loss caused by radiation exposure during spaceflight. In animal studies, excess free radical formation is associated with pathological changes in bone structure, enhanced bone resorption, reduced bone formation and decreased bone mineral density, which can lead to skeletal fragility. We previously reported that exposure to low or high-LET radiation rapidly increases expression levels of pro-osteoclastogenic and oxidative stress-related genes in bone and marrow, followed by pathological changes in skeletal structure. To screen various antioxidants for radioprotective effects on bone, 4 month old, male C57Bl6/J mice were treated with a dietary antioxidant cocktail, injectable alpha-lipoic acid, or a dried plum-enriched diet (DP). Mice were then exposed to 2Gy 137Cs total body radiation and one day later marrow cells were collected and the relevant genes analyzed for expression levels. Of the candidates tested, DP was most effective in reducing bone resorption-related gene expression. Microcomputed tomography revealed that DP also prevented the radiation-induced deterioration of skeletal microarchitecture, as indicated by percent bone volume, trabecular spacing and trabecular number. DP had similar protective effects on skeletal structure after sequential exposure to protons (0.5 Gy, 150MeV/n) and 56Fe 0.5Gy, 600 MeV/n). When cultured ex vivo under osteogenic conditions, bone marrow-derived cells from DP-fed animals exhibited increased colony numbers compared to control diet-fed animals. These findings suggest that DP exerted pro-osteogenic effects apart from previously identified anti-resorptive actions, which may contribute to radioprotection of skeletal tissue. In conclusion, a diet enriched in certain types of antioxidants and polyphenols such as DP may be useful as an intervention to protect tissues from degenerative effects of ionizing radiation.

  16. Acute exposure to solar simulated ultraviolet radiation affects oxidative stress-related biomarkers in skin, liver and blood of hairless mice.

    PubMed

    Svobodová, Alena Rajnochová; Galandáková, Adéla; Sianská, Jarmila; Doležal, Dalibor; Ulrichová, Jitka; Vostálová, Jitka

    2011-01-01

    The ultraviolet (UV) region of solar radiation is a critical factor in the initiation and development of a number of skin diseases. However, it is not only skin which is directly exposed to solar light that is affected by UV radiation, through low molecular weight mediators, generated upon irradiation, "non-skin" tissues can also be affected. The aim of this study was to examine in detail, the acute effects of UVA and UVB wavebands on hairless mice. Female SKH-1 hairless mice were exposed to a single dose of UVB (200, 800 mJ/cm(2)) or UVA (10, 20 J/cm(2)) using a solar simulator. The effects on haematological parameters, activity and/or expression of antioxidant enzymes, level of glutathione (GSH), markers of oxidative damage (lipid peroxidation and carbonylated proteins) were analysed in erythrocytes, plasma, liver and whole skin homogenates. No macroscopic changes were observed either 4 or 24 h after UVA/UVB exposure. The blood count showed a significant increase in leukocyte number and reduction of platelets 4 h following UVA and UVB irradiation, which disappeared 24 h after irradiation except for the higher UVA dose. Changes in oxidative stress-related parameters, particularly activity of catalase (CAT) and superoxide dismutase (SOD) and level of GSH and lipid peroxidation products, were found in skin, erythrocytes and liver. The expression of several enzymes (CAT, SOD, glutathione transferase (GST), nicotinamide adenine dinucleotide (phosphate) quinone oxidoreductase (NQO1) and hem oxygenase-1 (HO-1)) in skin was affected following UVA and UVB radiation. Increase in carbonylated proteins was found in plasma and skin samples.

  17. Glutathione Deficiency of the Arabidopsis Mutant pad2-1 Affects Oxidative Stress-Related Events, Defense Gene Expression, and the Hypersensitive Response1[C][W][OA

    PubMed Central

    Dubreuil-Maurizi, Carole; Vitecek, Jan; Marty, Laurent; Branciard, Lorelise; Frettinger, Patrick; Wendehenne, David; Meyer, Andreas J.; Mauch, Felix; Poinssot, Benoît

    2011-01-01

    The Arabidopsis (Arabidopsis thaliana) phytoalexin-deficient mutant pad2-1 displays enhanced susceptibility to a broad range of pathogens and herbivorous insects that correlates with deficiencies in the production of camalexin, indole glucosinolates, and salicylic acid (SA). The pad2-1 mutation is localized in the GLUTAMATE-CYSTEINE LIGASE (GCL) gene encoding the first enzyme of glutathione biosynthesis. While pad2-1 glutathione deficiency is not caused by a decrease in GCL transcripts, analysis of GCL protein level revealed that pad2-1 plants contained only 48% of the wild-type protein amount. In contrast to the wild type, the oxidized form of GCL was dominant in pad2-1, suggesting a distinct redox environment. This finding was corroborated by the expression of GRX1-roGFP2, showing that the cytosolic glutathione redox potential was significantly less negative in pad2-1. Analysis of oxidative stress-related gene expression showed a higher transcript accumulation in pad2-1 of GLUTATHIONE REDUCTASE, GLUTATHIONE-S-TRANSFERASE, and RESPIRATORY BURST OXIDASE HOMOLOG D in response to the oomycete Phytophthora brassicae. Interestingly, oligogalacturonide elicitation in pad2-1 revealed a lower plasma membrane depolarization that was found to act upstream of an impaired hydrogen peroxide production. This impaired hydrogen peroxide production was also observed during pathogen infection and correlated with a reduced hypersensitive response in pad2-1. In addition, a lack of pathogen-triggered expression of the ISOCHORISMATE SYNTHASE1 gene, coding for the SA-biosynthetic enzyme isochorismate synthase, was identified as the cause of the SA deficiency in pad2-1. Together, our results indicate that the pad2-1 mutation is related to a decrease in GCL protein and that the resulting glutathione deficiency negatively affects important processes of disease resistance. PMID:22007023

  18. 4-Nonylphenol induces disruption of spermatogenesis associated with oxidative stress-related apoptosis by targeting p53-Bcl-2/Bax-Fas/FasL signaling.

    PubMed

    Duan, Peng; Hu, Chunhui; Butler, Holly J; Quan, Chao; Chen, Wei; Huang, Wenting; Tang, Sha; Zhou, Wei; Yuan, Meng; Shi, Yuqin; Martin, Francis L; Yang, Kedi

    2017-03-01

    4-Nonylphenol (NP) is a ubiquitous environmental chemical with estrogenic activity. Our aim was to test the hypothesis that pubertal exposure to NP leads to testicular dysfunction. Herein, 24 7-week-old rats were randomly divided into four groups and treated with NP (0, 25, 50, or 100 mg/kg body weight every 2 days for 20 consecutive days) by intraperitoneal injection. Compared to untreated controls, the parameters of sperm activation rate, curvilinear velocity, average path velocity, and swimming velocity were significantly lower at doses of 100 mg/kg, while sperm morphological abnormalities were higher, indicating functional disruption and reduced fertilization potential. High exposure to NP (100 mg/kg) resulted in disordered arrangement of spermatoblasts and reduction of spermatocytes in seminiferous tubules, while tissues exhibited a marked decline in testicular fructose content and serum FSH, LH, and testosterone levels. Oxidative stress was induced by NP (50 or 100 mg/kg) as evidenced by elevated MDA, decreased SOD and GSH-Px, and inhibited antioxidant gene expression (CAT, GPx, SOD1, and CYP1B1). In addition, NP treatment decreased proportions of Ki-67-positive cells and increased apoptosis in a dose-dependent manner. Rats treated with 100 mg/kg NP exhibited significantly increased mRNA expression of caspase-1, -2, -9, and -11, decreased caspase-8 and PCNA1 mRNA expression, downregulation of Bcl-2/Bax ratios and upregulation of Fas, FasL, and p53 at the protein and mRNA levels. Taken together, NP-induced apoptosis, hormonal deficiencies, and depletion of fructose potentially impairs spermatogenesis and sperm function. p53-independent Fas/FasL-Bax/Bcl-2 pathways may be involved in NP-induced oxidative stress-related apoptosis. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 739-753, 2017.

  19. Apricot Melanoidins Prevent Oxidative Endothelial Cell Death by Counteracting Mitochondrial Oxidation and Membrane Depolarization

    PubMed Central

    Giordo, Roberta; Emanueli, Costanza; Sanguinetti, Anna Maria; Piscopo, Amalia; Poiana, Marco; Capobianco, Giampiero; Piga, Antonio; Pintus, Gianfranco

    2012-01-01

    The cardiovascular benefits associated with diets rich in fruit and vegetables are thought to be due to phytochemicals contained in fresh plant material. However, whether processed plant foods provide the same benefits as unprocessed ones is an open question. Melanoidins from heat-processed apricots were isolated and their presence confirmed by colorimetric analysis and browning index. Oxidative injury of endothelial cells (ECs) is the key step for the onset and progression of cardiovascular diseases (CVD), therefore the potential protective effect of apricot melanoidins on hydrogen peroxide-induced oxidative mitochondrial damage and cell death was explored in human ECs. The redox state of cytoplasmic and mitochondrial compartments was detected by using the redox-sensitive, fluorescent protein (roGFP), while the mitochondrial membrane potential (MMP) was assessed with the fluorescent dye, JC-1. ECs exposure to hydrogen peroxide, dose-dependently induced mitochondrial and cytoplasmic oxidation. Additionally detected hydrogen peroxide-induced phenomena were MMP dissipation and ECs death. Pretreatment of ECs with apricot melanoidins, significantly counteracted and ultimately abolished hydrogen peroxide-induced intracellular oxidation, mitochondrial depolarization and cell death. In this regard, our current results clearly indicate that melanoidins derived from heat-processed apricots, protect human ECs against oxidative stress. PMID:23144984

  20. Oxidative stress caused by blocking of mitochondrial complex I H(+) pumping as a link in aging/disease vicious cycle.

    PubMed

    Dlasková, Andrea; Hlavatá, Lydie; Jezek, Petr

    2008-01-01

    Vulnerability of mitochondrial Complex I to oxidative stress determines an organism's lifespan, pace of aging, susceptibility to numerous diseases originating from oxidative stress and certain mitopathies. The mechanisms involved, however, are largely unknown. We used confocal microscopy and fluorescent probe MitoSOX to monitor superoxide production due to retarded forward electron transport in HEPG2 cell mitochondrial Complex I in situ. Matrix-released superoxide production, the un-dismuted surplus (J(m)) was low in glucose-cultivated cells, where an uncoupler (FCCP) reduced it to half. Rotenone caused a 5-fold J(m) increase (AC(50) 2 microM), which was attenuated by uncoupling, membrane potential (DeltaPsi(m)), and DeltapH-collapse, since addition of FCCP (IC(50) 55 nM), valinomycin, and nigericin prevented this increase. J(m) doubled after cultivation with galactose/glutamine (i.e. at obligatory oxidative phosphorylation). A hydrophobic amiloride that acts on the ND5 subunit and inhibits Complex I H(+) pumping enhanced J(m) and even countered the FCCP effect (AC(50) 0.3 microM). Consequently, we have revealed a new principle predicting that Complex I produces maximum superoxide only when both electron transport and H(+) pumping are retarded. H(+) pumping may be attenuated by high protonmotive force or inhibited by oxidative stress-related mutations of ND5 (ND2, ND4) subunit. We predict that in a vicious cycle, when oxidative stress leads to higher fraction of, e.g. mutated ND5 subunits, it will be accelerated more and more. Thus, inhibition of Complex I H(+) pumping, which leads to oxidative stress, appears to be a missing link in the theory of mitochondrial aging and in the etiology of diseases related to oxidative stress.

  1. CONTROL OF GLUTAMATE OXIDATION IN BRAIN AND LIVER MITOCHONDRIAL SYSTEMS.

    PubMed

    BALAZS, R

    1965-05-01

    1. Glutamate oxidation in brain and liver mitochondrial systems proceeds mainly through transamination with oxaloacetate followed by oxidation of the alpha-oxoglutarate formed. Both in the presence and absence of dinitrophenol in liver mitochondria this pathway accounted for almost 80% of the uptake of glutamate. In brain preparations the transamination pathway accounted for about 90% of the glutamate uptake. 2. The oxidation of [1-(14)C]- and [5-(14)C]-glutamate in brain preparations is compatible with utilization through the tricarboxylic acid cycle, either after the formation of alpha-oxoglutarate or after decarboxylation to form gamma-aminobutyrate. There is no indication of gamma-decarboxylation of glutamate. 3. The high respiratory control ratio obtained with glutamate as substrate in brain mitochondrial preparations is due to the low respiration rate in the absence of ADP: this results from the low rate of formation of oxaloacetate under these conditions. When oxaloacetate is made available by the addition of malate or of NAD(+), the respiration rate is increased to the level obtained with other substrates. 4. When the transamination pathway of glutamate oxidation was blocked with malonate, the uptake of glutamate was inhibited in the presence of ADP or ADP plus dinitrophenol by about 70 and 80% respectively in brain mitochondrial systems, whereas the inhibition was only about 50% in dinitrophenol-stimulated liver preparations. In unstimulated liver mitochondria in the presence of malonate there was a sixfold increase in the oxidation of glutamate by the glutamate-dehydrogenase pathway. Thus the operating activity of glutamate dehydrogenase is much less than the ;free' (non-latent) activity. 5. The following explanation is put forward for the control of glutamate metabolism in liver and brain mitochondrial preparations. The oxidation of glutamate by either pathway yields alpha-oxoglutarate, which is further metabolized. Since aspartate aminotransferase is

  2. Mitochondrial Oxidative Stress, Mitochondrial DNA Damage and Their Role in Age-Related Vascular Dysfunction

    PubMed Central

    Mikhed, Yuliya; Daiber, Andreas; Steven, Sebastian

    2015-01-01

    The prevalence of cardiovascular diseases is significantly increased in the older population. Risk factors and predictors of future cardiovascular events such as hypertension, atherosclerosis, or diabetes are observed with higher frequency in elderly individuals. A major determinant of vascular aging is endothelial dysfunction, characterized by impaired endothelium-dependent signaling processes. Increased production of reactive oxygen species (ROS) leads to oxidative stress, loss of nitric oxide (•NO) signaling, loss of endothelial barrier function and infiltration of leukocytes to the vascular wall, explaining the low-grade inflammation characteristic for the aged vasculature. We here discuss the importance of different sources of ROS for vascular aging and their contribution to the increased cardiovascular risk in the elderly population with special emphasis on mitochondrial ROS formation and oxidative damage of mitochondrial DNA. Also the interaction (crosstalk) of mitochondria with nicotinamide adenosine dinucleotide phosphate (NADPH) oxidases is highlighted. Current concepts of vascular aging, consequences for the development of cardiovascular events and the particular role of ROS are evaluated on the basis of cell culture experiments, animal studies and clinical trials. Present data point to a more important role of oxidative stress for the maximal healthspan (healthy aging) than for the maximal lifespan. PMID:26184181

  3. Bushen-Yizhi formula ameliorates cognition deficits and attenuates oxidative stress-related neuronal apoptosis in scopolamine-induced senescence in mice

    PubMed Central

    HOU, XUE-QIN; WU, DIAN-WEI; ZHANG, CHUN-XIA; YAN, RONG; YANG, CONG; RONG, CUI-PING; ZHANG, LEI; CHANG, XIANG; SU, RU-YU; ZHANG, SHI-JIE; HE, WEN-QING; QU, ZHAO; LI, SHI; SU, ZI-REN; CHEN, YUN-BO; WANG, QI; FANG, SHU-HUAN

    2014-01-01

    Bushen-Yizhi formula (BSYZ), a traditional Chinese medicine formula consisting of six herbs has been reported to possess a neuroprotective effect. The present study aimed to investigate the effects of BSYZ on learning and memory abilities, as well as oxidative stress and neuronal apoptosis in the hippocampus of scopolamine (SCOP)-induced senescence in mice, in order to reveal whether BSYZ is a potential therapeutic agent for Alzheimer’s disease (AD). A high-performance liquid chromatography (HPLC) fingerprint was applied to provide a chemical profile of BSYZ. Extracts of BSYZ were orally administered to mice with SCOP-induced memory impairment for two weeks. The learning and memory abilities were determined by the Morris water maze test. The oxidant stress-related indices, such as activity of superoxide dismutase (SOD) and levels of glutathione (GSH) and malondialdehyde (MDA) were examined in hippocampus of SCOP-treated mice. The cell death ratio was assessed by TUNEL staining, while apoptotic-related proteins including Bcl-2 and Bax were determined by immunofluorescent staining and western blot analysis. Caspase-3 was determined by western blot analysis. Consequently, a chromatographic condition, which was conducted at 35°C with a flow rate of 0.8 ml/min on the Gemini C18 column with mobile phase of acetonitrile and water-phosphoric acid (100:0.1, v/v), was established to yield common fingerprint chromatography under 203 nm with a similarity index of 0.986 within 10 batches of BSYZ samples. BSYZ at a dose of 2.92 g/kg significantly improved the cognitive ability, restored the abnormal activity of SOD and increased the levels of MDA and GSH induced by SCOP. Moreover, the neural apoptosis in the hippocampus of SCOP-treated mice was reversed by BSYZ by regulating the expression of Bcl-2, Bax and caspase-3. The results demonstrated that BSYZ had neuroprotective effects in SCOP-induced senescence in mice by ameliorating oxidative stress and neuronal apoptosis in the

  4. Curcumin alleviates oxidative stress and mitochondrial dysfunction in astrocytes.

    PubMed

    Daverey, Amita; Agrawal, Sandeep K

    2016-10-01

    Oxidative stress plays a critical role in various neurodegenerative diseases, thus alleviating oxidative stress is a potential strategy for therapeutic intervention and/or prevention of neurodegenerative diseases. In the present study, alleviation of oxidative stress through curcumin is investigated in A172 (human glioblastoma cell line) and HA-sp (human astrocytes cell line derived from the spinal cord) astrocytes. H2O2 was used to induce oxidative stress in astrocytes (A172 and HA-sp). Data show that H2O2 induces activation of astrocytes in dose- and time-dependent manner as evident by increased expression of GFAP in A172 and HA-sp cells after 24 and 12h respectively. An upregulation of Prdx6 was also observed in A172 and HA-sp cells after 24h of H2O2 treatment as compared to untreated control. Our data also showed that curcumin inhibits oxidative stress-induced cytoskeleton disarrangement, and impedes the activation of astrocytes by inhibiting upregulation of GFAP, vimentin and Prdx6. In addition, we observed an inhibition of oxidative stress-induced inflammation, apoptosis and mitochondria fragmentation after curcumin treatment. Therefore, our results suggest that curcumin not only protects astrocytes from H2O2-induced oxidative stress but also reverses the mitochondrial damage and dysfunction induced by oxidative stress. This study also provides evidence for protective role of curcumin on astrocytes by showing its effects on attenuating reactive astrogliosis and inhibiting apoptosis.

  5. Modulation of natural IgM autoantibodies to oxidative stress-related neo-epitopes on apoptotic cells in newborns of mothers with anti-Ro autoimmunity.

    PubMed

    Grönwall, Caroline; Clancy, Robert M; Getu, Lelise; Lloyd, Katy A; Siegel, Don L; Reed, Joanne H; Buyon, Jill P; Silverman, Gregg J

    2016-09-01

    At birth, the human immune system already contains substantial levels of polymeric IgM, that include autoantibodies to neo-epitopes on apoptotic cells (ACs) that are proposed to play homeostatic and anti-inflammatory roles. Yet the biologic origins and developmental regulation of these naturally arising antibodies remain poorly understood. Herein, we report that levels of IgM-antibodies to malondialdehyde (MDA) protein adducts, a common type of in vivo generated oxidative stress-related neoepitope, directly correlate with the relative binding of neonatal-IgM to ACs. Levels of IgM to phosphorylcholine (PC), a natural antibody prevalent in adults, were relatively scant in cord blood, while there was significantly greater relative representation of IgM anti-MDA antibodies in newborns compared to adults. To investigate the potential interrelationships between neonatal IgM with pathogenic IgG-autoantibodies, we studied 103 newborns born to autoimmune mothers with IgG anti-Ro (i.e., 70 with neonatal lupus and 33 without neonatal lupus). In these subjects the mean levels of IgM anti-Ro60 were significantly higher than in the newborns from non-autoimmune mothers. In contrast, levels of IgM anti-MDA in IgG anti-Ro exposed neonates were significantly lower than in neonates from non-autoimmune mothers. The presence or absence of neonatal lupus did not appear to influence the total levels of IgM in the anti-Ro exposed newborns. Taken together, our studies provide evidence that the immune development of the natural IgM-repertoire may be affected, and become imprinted by, the transfer of maternal IgG into the fetus. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Transcriptomics in Interferon-α-Treated Patients Identifies Inflammation-, Neuroplasticity- and Oxidative Stress-Related Signatures as Predictors and Correlates of Depression

    PubMed Central

    Hepgul, Nilay; Cattaneo, Annamaria; Agarwal, Kosh; Baraldi, Sara; Borsini, Alessandra; Bufalino, Chiara; Forton, Daniel M; Mondelli, Valeria; Nikkheslat, Naghmeh; Lopizzo, Nicola; Riva, Marco A; Russell, Alice; Hotopf, Matthew; Pariante, Carmine M

    2016-01-01

    Owing to the unique opportunity to assess individuals before and after they develop depression within a short timeframe, interferon-α (IFN-α) treatment for chronic hepatitis C virus (HCV) infection is an ideal model to identify molecular mechanisms relevant to major depression, especially in the context of enhanced inflammation. Fifty-eight patients were assessed prospectively, at baseline and monthly over 24 weeks of IFN-α treatment. New-onset cases of depression were determined using the Mini International Neuropsychiatric Interview (MINI). Whole-blood transcriptomic analyses were conducted to investigate the following: (1) baseline gene expression differences associated with future development of IFN-α-induced depression, before IFN-α, and (2) longitudinal gene expression changes from baseline to weeks 4 or 24 of IFN-α treatment, separately in those who did and did not develop depression. Transcriptomics data were analyzed using Partek Genomics Suite (1.4-fold, FDR adjusted p⩽0.05) and Ingenuity Pathway Analysis Software. Twenty patients (34%) developed IFN-α-induced depression. At baseline, 73 genes were differentially expressed in patients who later developed depression compared with those who did not. After 4 weeks of IFN-α treatment, 592 genes were modulated in the whole sample, representing primarily IFN-α-responsive genes. Substantially more genes were modulated only in patients who developed depression (n=506, compared with n=70 in patients who did not), with enrichment in inflammation-, neuroplasticity- and oxidative stress-related pathways. A similar picture was observed at week 24. Our data indicate that patients who develop IFN-α-induced depression have an increased biological sensitivity to IFN-α, as shown by larger gene expression changes, and specific signatures both as predictors and as correlates. PMID:27067128

  7. Evaluation of different culture systems with low oxygen tension on the development, quality and oxidative stress-related genes of bovine embryos produced in vitro.

    PubMed

    Arias, Maria Elena; Sanchez, Raul; Felmer, Ricardo

    2012-08-01

    The present study was conducted to assess the development, quality and gene expression profile of oxidative stress-related genes of bovine embryos cultured in different culture systems with low oxygen tension (5% CO2, 5% O2 and 90% N2). The systems assessed included: (1) an incubator chamber; (2) a plastic bag; and (3) a foil bag. The choice of culture system had no effect on cleavage rate at 72 h. However, significant differences (P < 0.01) were observed in the rate of blastocysts registered at day 7 (29.8, 20.2 and 12.7% for incubator chamber, plastic bag and foil bag, respectively). Total number of cells did not differ between systems, although the proportion of ICM:total cells was affected particularly in the plastic bag (19.5%), compared with the incubator chamber (31.4%). In addition, significant differences were found in the apoptotic:total cell ratio (3.3, 6.5 and 8.8% for the incubator chamber, plastic bag and foil bag, respectively), with apoptotic nuclei localised mainly in the ICM compartment of the embryo. The amount of reactive oxygen species was also different between culture systems and this effect was correlated with a higher expression of SOD2, GSS and GPX1 genes in embryos cultured in the gassed bags as compared with embryos cultured in the incubator chamber. In conclusion, these results give evidence that, under low oxygen tension, the incubator chamber is more efficient and generates higher number of, and better quality, embryos than gassed bag systems evaluated here and this effect was probably due to an increased level of reactive oxygen species in the gassed bags, which upregulates the expression of some antioxidant enzymes to compensate for hyperoxia conditions.

  8. Mitochondrial Dysfunction Due to Oxidative Mitochondrial DNA Damage Is Reduced through Cooperative Actions of Diverse Proteins

    PubMed Central

    O'Rourke, Thomas W.; Doudican, Nicole A.; Mackereth, Melinda D.; Doetsch, Paul W.; Shadel, Gerald S.

    2002-01-01

    The mitochondrial genome is a significant target of exogenous and endogenous genotoxic agents; however, the determinants that govern this susceptibility and the pathways available to resist mitochondrial DNA (mtDNA) damage are not well characterized. Here we report that oxidative mtDNA damage is elevated in strains lacking Ntg1p, providing the first direct functional evidence that this mitochondrion-localized, base excision repair enzyme functions to protect mtDNA. However, ntg1 null strains did not exhibit a mitochondrial respiration-deficient (petite) phenotype, suggesting that mtDNA damage is negotiated by the cooperative actions of multiple damage resistance pathways. Null mutations in ABF2 or PIF1, two genes implicated in mtDNA maintenance and recombination, exhibit a synthetic-petite phenotype in combination with ntg1 null mutations that is accompanied by enhanced mtDNA point mutagenesis in the corresponding double-mutant strains. This phenotype was partially rescued by malonic acid, indicating that reactive oxygen species generated by the electron transport chain contribute to mitochondrial dysfunction in abf2Δ strains. In contrast, when two other genes involved in mtDNA recombination, CCE1 and NUC1, were inactivated a strong synthetic-petite phenotype was not observed, suggesting that the effects mediated by Abf2p and Pif1p are due to novel activities of these proteins other than recombination. These results document the existence of recombination-independent mechanisms in addition to base excision repair to cope with oxidative mtDNA damage in Saccharomyces cerevisiae. Such systems are likely relevant to those operating in human cells where mtDNA recombination is less prevalent, validating yeast as a model system in which to study these important issues. PMID:12024022

  9. Stress-related cardiomyopathies

    PubMed Central

    2011-01-01

    Stress-related cardiomyopathies can be observed in the four following situations: Takotsubo cardiomyopathy or apical ballooning syndrome; acute left ventricular dysfunction associated with subarachnoid hemorrhage; acute left ventricular dysfunction associated with pheochromocytoma and exogenous catecholamine administration; acute left ventricular dysfunction in the critically ill. Cardiac toxicity was mediated more by catecholamines released directly into the heart via neural connection than by those reaching the heart via the bloodstream. The mechanisms underlying the association between this generalized autonomic storm secondary to a life-threatening stress and myocardial toxicity are widely discussed. Takotsubo cardiomyopathy has been reported all over the world and has been acknowledged by the American Heart Association as a form of reversible cardiomyopathy. Four "Mayo Clinic" diagnostic criteria are required for the diagnosis of Takotsubo cardiomyopathy: 1) transient left ventricular wall motion abnormalities involving the apical and/or midventricular myocardial segments with wall motion abnormalities extending beyond a single epicardial coronary artery distribution; 2) absence of obstructive epicardial coronary artery disease that could be responsible for the observed wall motion abnormality; 3) ECG abnormalities, such as transient ST-segment elevation and/or diffuse T wave inversion associated with a slight troponin elevation; and 4) the lack of proven pheochromocytoma and myocarditis. ECG changes and LV dysfunction occur frequently following subarachnoid hemorrhage and ischemic stroke. This entity, referred as neurocardiogenic stunning, was called neurogenic stress-related cardiomyopathy. Stress-related cardiomyopathy has been reported in patients with pheochromocytoma and in patients receiving intravenous exogenous catecholamine administration. The role of a huge increase in endogenous and/or exogenous catecholamine level in critically ill patients

  10. Mitochondrial accumulation under oxidative stress is due to defects in autophagy.

    PubMed

    Luo, Cheng; Li, Yan; Wang, Hui; Feng, Zhihui; Li, Yuan; Long, Jiangang; Liu, Jiankang

    2013-01-01

    Mitochondrial dynamics maintains normal mitochondrial function by degrading damaged mitochondria and generating newborn mitochondria. The accumulation of damaged mitochondria influences the intracellular environment by promoting mitochondrial dysfunction, and thus initiating a vicious cycle. Oxidative stress induces mitochondrial malfunction, which is involved in many cardiovascular diseases. However, the mechanism of mitochondrial accumulation in cardiac myoblasts remains unclear. We observed mitochondrial dysfunction and an increase in mitochondrial mass under the oxidative conditions produced by tert-butyl hydroperoxide (tBHP) in cardiac myoblast H9c2 cells. However, in contrast to the increase in mitochondrial mass, mitochondrial DNA (mtDNA) decreased, suggesting that enhanced mitochondrial biogenesis may be not the primary cause of the mitochondrial accumulation. Therefore, we investigated changes in a number of proteins involved in autophagy. Beclin1, Atg12-Atg5 conjugate, Atg7 contents decreased but LC3-II accumulated in tBHP-treated H9c2 cells. Moreover, the capacity for acid hydrolysis decreased in H9c2 cells. We also demonstrated a decrease in DJ-1 protein under the oxidative conditions that deregulate mitochondrial dynamics. These results reveal that autophagy became defective under oxidative stress. We therefore suggest that defects in autophagy mediate mitochondrial accumulation under these conditions.

  11. Diabetes and mitochondrial function: Role of hyperglycemia and oxidative stress

    SciTech Connect

    Rolo, Anabela P.; Palmeira, Carlos M. . E-mail: palmeira@ci.uc.pt

    2006-04-15

    Hyperglycemia resulting from uncontrolled glucose regulation is widely recognized as the causal link between diabetes and diabetic complications. Four major molecular mechanisms have been implicated in hyperglycemia-induced tissue damage: activation of protein kinase C (PKC) isoforms via de novo synthesis of the lipid second messenger diacylglycerol (DAG), increased hexosamine pathway flux, increased advanced glycation end product (AGE) formation, and increased polyol pathway flux. Hyperglycemia-induced overproduction of superoxide is the causal link between high glucose and the pathways responsible for hyperglycemic damage. In fact, diabetes is typically accompanied by increased production of free radicals and/or impaired antioxidant defense capabilities, indicating a central contribution for reactive oxygen species (ROS) in the onset, progression, and pathological consequences of diabetes. Besides oxidative stress, a growing body of evidence has demonstrated a link between various disturbances in mitochondrial functioning and type 2 diabetes. Mutations in mitochondrial DNA (mtDNA) and decreases in mtDNA copy number have been linked to the pathogenesis of type 2 diabetes. The study of the relationship of mtDNA to type 2 diabetes has revealed the influence of the mitochondria on nuclear-encoded glucose transporters, glucose-stimulated insulin secretion, and nuclear-encoded uncoupling proteins (UCPs) in {beta}-cell glucose toxicity. This review focuses on a range of mitochondrial factors important in the pathogenesis of diabetes. We review the published literature regarding the direct effects of hyperglycemia on mitochondrial function and suggest the possibility of regulation of mitochondrial function at a transcriptional level in response to hyperglycemia. The main goal of this review is to include a fresh consideration of pathways involved in hyperglycemia-induced diabetic complications.

  12. Effects of dietary fatty acids on mitochondrial phospholipid compositions, oxidative status and mitochondrial gene expression of zebrafish at different ages.

    PubMed

    Betancor, M B; Almaida-Pagán, P F; Hernández, A; Tocher, D R

    2015-10-01

    Mitochondrial decay is generally associated with impairment in the organelle bioenergetics function and increased oxidative stress, and it appears that deterioration of mitochondrial inner membrane phospholipids (PL) and accumulation of mitochondrial DNA (mtDNA) mutations are among the main mechanisms involved in this process. In the present study, mitochondrial membrane PL compositions, oxidative status (TBARS content and SOD activity) and mtDNA gene expression of muscle and liver were analyzed in zebrafish fed two diets with lipid supplied either by rapeseed oil (RO) or a blend 60:40 of RO and DHA500 TG oil (DHA). Two feeding trials were performed using zebrafish from the same population of two ages (8 and 21 months). Dietary FA composition affected fish growth in 8-month-old animals, which could be related to an increase in stress promoted by diet composition. Lipid peroxidation was considerably higher in mitochondria of 8-month-old zebrafish fed the DHA diet than in animals fed the RO diet. This could indicate higher oxidative damage to mitochondrial lipids, very likely due to increased incorporation of DHA in PL of mitochondrial membranes. Lipids would be among the first molecules affected by mitochondrial reactive oxygen species, and lipid peroxidation could propagate oxidative reactions that would damage other molecules, including mtDNA. Mitochondrial lipid peroxidation and gene expression of 21-month-old fish showed lower responsiveness to diet composition than those of younger fish. Differences found in the effect of diet composition on mitochondrial lipids between the two age groups could be indicating age-related changes in the ability to maintain structural homeostasis of mitochondrial membranes.

  13. Inhibitors of mitochondrial fission as a therapeutic strategy for diseases with oxidative stress and mitochondrial dysfunction.

    PubMed

    Reddy, P Hemachandra

    2014-01-01

    Mitochondria are essential cytoplasmic organelles, critical for cell survival and death. Recent mitochondrial research revealed that mitochondrial dynamics-the balance of fission and fusion in normal mitochondrial dynamics--is an important cellular mechanism in eukaryotic cell and is involved in the maintenance of mitochondrial morphology, structure, number, distribution, and function. Research into mitochondria and cell function has revealed that mitochondrial dynamics is impaired in a large number of aging and neurodegenerative diseases, and in several inherited mitochondrial diseases, and that this impairment involves excessive mitochondrial fission, resulting in mitochondrial structural changes and dysfunction, and cell damage. Attempts have been made to develop molecules to reduce mitochondrial fission while maintaining normal mitochondrial fusion and function in those diseases that involve excessive mitochondrial fission. This review article discusses mechanisms of mitochondrial fission in normal and diseased states of mammalian cells and discusses research aimed at developing therapies, such as Mdivi, Dynasore and P110, to prevent or to inhibit excessive mitochondrial fission.

  14. Avocado Oil Improves Mitochondrial Function and Decreases Oxidative Stress in Brain of Diabetic Rats.

    PubMed

    Ortiz-Avila, Omar; Esquivel-Martínez, Mauricio; Olmos-Orizaba, Berenice Eridani; Saavedra-Molina, Alfredo; Rodriguez-Orozco, Alain R; Cortés-Rojo, Christian

    2015-01-01

    Diabetic encephalopathy is a diabetic complication related to the metabolic alterations featuring diabetes. Diabetes is characterized by increased lipid peroxidation, altered glutathione redox status, exacerbated levels of ROS, and mitochondrial dysfunction. Although the pathophysiology of diabetic encephalopathy remains to be clarified, oxidative stress and mitochondrial dysfunction play a crucial role in the pathogenesis of chronic diabetic complications. Taking this into consideration, the aim of this work was to evaluate the effects of 90-day avocado oil intake in brain mitochondrial function and oxidative status in streptozotocin-induced diabetic rats (STZ rats). Avocado oil improves brain mitochondrial function in diabetic rats preventing impairment of mitochondrial respiration and mitochondrial membrane potential (ΔΨ m ), besides increasing complex III activity. Avocado oil also decreased ROS levels and lipid peroxidation and improved the GSH/GSSG ratio as well. These results demonstrate that avocado oil supplementation prevents brain mitochondrial dysfunction induced by diabetes in association with decreased oxidative stress.

  15. Avocado Oil Improves Mitochondrial Function and Decreases Oxidative Stress in Brain of Diabetic Rats

    PubMed Central

    Ortiz-Avila, Omar; Esquivel-Martínez, Mauricio; Olmos-Orizaba, Berenice Eridani; Saavedra-Molina, Alfredo; Rodriguez-Orozco, Alain R.; Cortés-Rojo, Christian

    2015-01-01

    Diabetic encephalopathy is a diabetic complication related to the metabolic alterations featuring diabetes. Diabetes is characterized by increased lipid peroxidation, altered glutathione redox status, exacerbated levels of ROS, and mitochondrial dysfunction. Although the pathophysiology of diabetic encephalopathy remains to be clarified, oxidative stress and mitochondrial dysfunction play a crucial role in the pathogenesis of chronic diabetic complications. Taking this into consideration, the aim of this work was to evaluate the effects of 90-day avocado oil intake in brain mitochondrial function and oxidative status in streptozotocin-induced diabetic rats (STZ rats). Avocado oil improves brain mitochondrial function in diabetic rats preventing impairment of mitochondrial respiration and mitochondrial membrane potential (ΔΨm), besides increasing complex III activity. Avocado oil also decreased ROS levels and lipid peroxidation and improved the GSH/GSSG ratio as well. These results demonstrate that avocado oil supplementation prevents brain mitochondrial dysfunction induced by diabetes in association with decreased oxidative stress. PMID:26180820

  16. Induced Pluripotent Stem Cell-Derived Conditioned Medium Attenuates Acute Kidney Injury by Downregulating the Oxidative Stress-Related Pathway in Ischemia-Reperfusion Rats.

    PubMed

    Tarng, Der-Cherng; Tseng, Wei-Cheng; Lee, Pei-Ying; Chiou, Shih-Hwa; Hsieh, Shie-Liang

    2016-01-01

    Teratoma-like formation addresses a critical safety concern for the potential utility of induced pluripotent stem cells (iPSCs). Therefore, therapy utilizing iPSC-derived conditioned medium (iPSC-CM) for acute kidney injury (AKI) has attracted substantial interest. A recent study showed that iPSC-CM effectively alleviated ventilator-induced lung injury in rats. It prompts us to assess the therapeutic effects of iPSC-CM on ischemic AKI. First, we assessed the changes in renal function and tubular cell apoptosis by intraperitoneal administration of iPSC-CM to ischemia-reperfusion (I/R) rats. Second, we explored the oxidative stress-related pathway in the apoptosis of renal tubular cells subjected to hypoxia-reoxygenation (H/R). Administration of iPSC-CM significantly improved renal function and protected tubular cells against apoptosis in rats with I/R-AKI, and the optimal effect was observed at the 50-fold concentrated iPSC-CM. iPSC-CM also mitigated the H/R-induced apoptosis of NRK-52E cells in vitro. Reactive oxygen species (ROS) production was augmented in kidneys following I/R and in NRK-52E cells subjected to H/R. Meanwhile, expressions of phosphorylated p38 MAPK, TNF-α, and cleaved caspase 3 and NF-κB activity were consistently increased in vivo and in vitro. Following administration of iPSC-CM, ROS production was abolished, and inflammatory cytokine expression was significantly suppressed. Annexin V-propidium iodide flow cytometry and in situ TUNEL assay further showed that iPSC-CM markedly attenuated H/R- or I/R-induced tubular cell apoptosis. Intriguingly, treatment with iPSC-CM significantly improved the survival of rats with I/R-induced AKI. iPSC-CM represents a favorable source of stem cell-based therapy and may serve as a potential therapeutic strategy for kidney repair in ischemic AKI.

  17. Genetic polymorphisms in oxidative stress-related genes are associated with outcomes following treatment for aggressive B-cell non-Hodgkin lymphoma.

    PubMed

    Gustafson, Heather L; Yao, Song; Goldman, Bryan H; Lee, Kristy; Spier, Catherine M; LeBlanc, Michael L; Rimsza, Lisa M; Cerhan, James R; Habermann, Thomas M; Link, Brian K; Maurer, Matthew J; Slager, Susan L; Persky, Daniel O; Miller, Thomas P; Fisher, Richard I; Ambrosone, Christine B; Briehl, Margaret M

    2014-06-01

    Variable survival outcomes are seen following treatment for aggressive non-Hodgkin lymphoma (NHL). This study examined whether outcomes for aggressive B-cell NHL are associated with single nucleotide polymorphisms (SNPs) in oxidative stress-related genes, which can alter drug metabolism and immune responses. Genotypes for 53 SNPs in 29 genes were determined for 337 patients given anthracycline-based therapies. Their associations with progression-free survival (PFS) and overall survival (OS) were estimated by Cox proportional hazard regression; associations with hematologic toxicity were estimated by logistic regression. To validate the findings, the top three SNPs were tested in an independent cohort of 572 DLBCL patients. The top SNPs associated with PFS in the discovery cohort were the rare homozygotes for MPO rs2243828 (hazard ratio [HR] = 1.87, 95% confidence interval [CI] = 1.14-3.06, P = 0.013), AKR1C3 rs10508293 (HR = 2.09, 95% CI = 1.28-3.41, P = 0.0032) and NCF4 rs1883112 (HR = 0.66, 95% CI = 0.43-1.02, P = 0.06). The association of the NCF4 SNP with PFS was replicated in the validation dataset (HR = 0.66, 95% CI = 0.44-1.01, P = 0.05) and the meta-analysis was significant (HR = 0.66, 95% CI = 0.49-0.89, P < 0.01). The association of the MPO SNP was attenuated in the validation dataset, while the meta-analysis remained significant (HR = 1.64, 95% CI = 1.12-2.41). These two SNPs showed similar trends with OS in the meta-analysis (for NCF4, HR = 0.72, 95% CI = 0.51-1.02, P = 0.07 and for MPO, HR = 2.06, 95% CI = 1.36-3.12, P < 0.01). In addition, patients with the rare homozygote of the NCF4 SNP had an increased risk of hematologic toxicity. We concluded that genetic variations in NCF4 may contribute to treatment outcomes for patients with aggressive NHL. © 2014 Wiley Periodicals, Inc.

  18. A mitochondrial superoxide theory for oxidative stress diseases and aging.

    PubMed

    Indo, Hiroko P; Yen, Hsiu-Chuan; Nakanishi, Ikuo; Matsumoto, Ken-Ichiro; Tamura, Masato; Nagano, Yumiko; Matsui, Hirofumi; Gusev, Oleg; Cornette, Richard; Okuda, Takashi; Minamiyama, Yukiko; Ichikawa, Hiroshi; Suenaga, Shigeaki; Oki, Misato; Sato, Tsuyoshi; Ozawa, Toshihiko; Clair, Daret K St; Majima, Hideyuki J

    2015-01-01

    Fridovich identified CuZnSOD in 1969 and manganese superoxide dismutase (MnSOD) in 1973, and proposed "the Superoxide Theory," which postulates that superoxide (O2 (•-)) is the origin of most reactive oxygen species (ROS) and that it undergoes a chain reaction in a cell, playing a central role in the ROS producing system. Increased oxidative stress on an organism causes damage to cells, the smallest constituent unit of an organism, which can lead to the onset of a variety of chronic diseases, such as Alzheimer's, Parkinson's, amyotrophic lateral sclerosis and other neurological diseases caused by abnormalities in biological defenses or increased intracellular reactive oxygen levels. Oxidative stress also plays a role in aging. Antioxidant systems, including non-enzyme low-molecular-weight antioxidants (such as, vitamins A, C and E, polyphenols, glutathione, and coenzyme Q10) and antioxidant enzymes, fight against oxidants in cells. Superoxide is considered to be a major factor in oxidant toxicity, and mitochondrial MnSOD enzymes constitute an essential defense against superoxide. Mitochondria are the major source of superoxide. The reaction of superoxide generated from mitochondria with nitric oxide is faster than SOD catalyzed reaction, and produces peroxynitrite. Thus, based on research conducted after Fridovich's seminal studies, we now propose a modified superoxide theory; i.e., superoxide is the origin of reactive oxygen and nitrogen species (RONS) and, as such, causes various redox related diseases and aging.

  19. Combined defects in oxidative phosphorylation and fatty acid β-oxidation in mitochondrial disease

    PubMed Central

    Nsiah-Sefaa, Abena; McKenzie, Matthew

    2016-01-01

    Mitochondria provide the main source of energy to eukaryotic cells, oxidizing fats and sugars to generate ATP. Mitochondrial fatty acid β-oxidation (FAO) and oxidative phosphorylation (OXPHOS) are two metabolic pathways which are central to this process. Defects in these pathways can result in diseases of the brain, skeletal muscle, heart and liver, affecting approximately 1 in 5000 live births. There are no effective therapies for these disorders, with quality of life severely reduced for most patients. The pathology underlying many aspects of these diseases is not well understood; for example, it is not clear why some patients with primary FAO deficiencies exhibit secondary OXPHOS defects. However, recent findings suggest that physical interactions exist between FAO and OXPHOS proteins, and that these interactions are critical for both FAO and OXPHOS function. Here, we review our current understanding of the interactions between FAO and OXPHOS proteins and how defects in these two metabolic pathways contribute to mitochondrial disease pathogenesis. PMID:26839416

  20. Mitochondrial free fatty acid β-oxidation supports oxidative phosphorylation and proliferation in cancer cells.

    PubMed

    Rodríguez-Enríquez, Sara; Hernández-Esquivel, Luz; Marín-Hernández, Alvaro; El Hafidi, Mohammed; Gallardo-Pérez, Juan Carlos; Hernández-Reséndiz, Ileana; Rodríguez-Zavala, José S; Pacheco-Velázquez, Silvia C; Moreno-Sánchez, Rafael

    2015-08-01

    Oxidative phosphorylation (OxPhos) is functional and sustains tumor proliferation in several cancer cell types. To establish whether mitochondrial β-oxidation of free fatty acids (FFAs) contributes to cancer OxPhos functioning, its protein contents and enzyme activities, as well as respiratory rates and electrical membrane potential (ΔΨm) driven by FFA oxidation were assessed in rat AS-30D hepatoma and liver (RLM) mitochondria. Higher protein contents (1.4-3 times) of β-oxidation (CPT1, SCAD) as well as proteins and enzyme activities (1.7-13-times) of Krebs cycle (KC: ICD, 2OGDH, PDH, ME, GA), and respiratory chain (RC: COX) were determined in hepatoma mitochondria vs. RLM. Although increased cholesterol content (9-times vs. RLM) was determined in the hepatoma mitochondrial membranes, FFAs and other NAD-linked substrates were oxidized faster (1.6-6.6 times) by hepatoma mitochondria than RLM, maintaining similar ΔΨm values. The contents of β-oxidation, KC and RC enzymes were also assessed in cells. The mitochondrial enzyme levels in human cervix cancer HeLa and AS-30D cells were higher than those observed in rat hepatocytes whereas in human breast cancer biopsies, CPT1 and SCAD contents were lower than in human breast normal tissue. The presence of CPT1 and SCAD in AS-30D mitochondria and HeLa cells correlated with an active FFA utilization in HeLa cells. Furthermore, the β-oxidation inhibitor perhexiline blocked FFA utilization, OxPhos and proliferation in HeLa and other cancer cells. In conclusion, functional mitochondria supported by FFA β-oxidation are essential for the accelerated cancer cell proliferation and hence anti-β-oxidation therapeutics appears as an alternative promising approach to deter malignant tumor growth. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Mitochondrial membrane potential: a novel biomarker of oxidative environmental stress.

    PubMed Central

    Vayssier-Taussat, Muriel; Kreps, Sarah E; Adrie, Christophe; Dall'Ava, Josette; Christiani, David; Polla, Barbara S

    2002-01-01

    Epidemiologic analyses, traditionally based on long-term cohort or case-control studies, provide retrospective causal associations between exposure to a particular environmental stressor and an exposure-related disease end point. Recent research initiatives have propelled a shift toward exploring molecular epidemiology and molecular biological markers (biomarkers) as a means of providing more immediate, quantitative risk assessment of potentially deleterious environmental exposures. We compared, in normal human monocytes isolated from the blood of healthy donors, variations in Hsp70 expression and mitochondrial membrane potential (delta psi m) in response to exposure to either tobacco smoke or gamma-irradiation, two models for environmentally mediated oxidant exposure. On the basis of its mechanistic specificity for oxidants and little baseline variation in cells from distinct individuals, we propose that delta psi m represents a selective in vitro and in vivo biomarker for oxidant exposure. delta psi m may be used to gauge risks associated with oxidant-mediated air pollution and radiation. PMID:11882482

  2. Effects of energy supply and nicotinic acid supplementation on serum anti-oxidative capacity and on expression of oxidative stress-related genes in blood leucocytes of periparturient primi- and pluriparous dairy cows.

    PubMed

    Bühler, S; Frahm, J; Tienken, R; Kersten, S; Meyer, U; Huber, K; Dänicke, S

    2017-04-25

    The periparturient period is accompanied by metabolic and oxidative stress. Niacin is known to decrease lipolysis but is also reported to have anti-oxidative effects. Therefore, we examined the effects of energy supply and a nicotinic acid (NA) supplementation on anti-oxidative serum parameters and on the expression of oxidative stress-related genes in blood leucocytes of periparturient dairy cows, differing in parity. Twenty-nine pluriparous and 18 primiparous cows were allocated to four different feeding groups 42 days before expected parturition until 100 days postpartum and fed a ration with either a low concentrate proportion of 30% (LC) or a high concentrate proportion of 60% (HC). After parturition, all animals received 30% concentrate which was increased to 50% either within 16 (LC group) or 24 days (HC group). Half of the animals per group were supplemented with 24 g NA per day from 42 days prepartum until 24 days postpartum. All investigated parameters varied significantly over time compared to parturition (p < .05). Ferric reducing ability (FRA) exhibited a nadir before parturition, and the antioxidant enzymes glutathione peroxidase (GPX) and superoxide dismutase (SOD) showed peak activities around parturition. Expression levels of GPX1, SOD2, xanthine dehydrogenase (XDH) and nuclear factor (erythroid-derived 2)-like 2 (NRF2) peaked before calving. The concentrate level influenced GPX activity and mRNA abundance of SOD2, XDH and poly (ADP-ribose) polymerase 1 (PARP1). Pluriparous animals exhibited higher serum GPX activities, a more distinct nadir for FRA and higher expression levels for GPX1, SOD2 and XDH. Primiparous cows displayed higher serum SOD activities. NA supplementation increased serum SOD activity antepartum in LC animals. Parturition was characterised by an increased need for antioxidants and an increased expression of oxidative stress-related genes that clearly differed with parity and was influenced by energy supply while NA

  3. Mitochondrial division ensures the survival of postmitotic neurons by suppressing oxidative damage

    PubMed Central

    Kageyama, Yusuke; Zhang, Zhongyan; Roda, Ricardo; Fukaya, Masahiro; Wakabayashi, Junko; Wakabayashi, Nobunao; Kensler, Thomas W.; Reddy, P. Hemachandra

    2012-01-01

    Mitochondria divide and fuse continuously, and the balance between these two processes regulates mitochondrial shape. Alterations in mitochondrial dynamics are associated with neurodegenerative diseases. Here we investigate the physiological and cellular functions of mitochondrial division in postmitotic neurons using in vivo and in vitro gene knockout for the mitochondrial division protein Drp1. When mouse Drp1 was deleted in postmitotic Purkinje cells in the cerebellum, mitochondrial tubules elongated due to excess fusion, became large spheres due to oxidative damage, accumulated ubiquitin and mitophagy markers, and lost respiratory function, leading to neurodegeneration. Ubiquitination of mitochondria was independent of the E3 ubiquitin ligase parkin in Purkinje cells lacking Drp1. Treatment with antioxidants rescued mitochondrial swelling and cell death in Drp1KO Purkinje cells. Moreover, hydrogen peroxide converted elongated tubules into large spheres in Drp1KO fibroblasts. Our findings suggest that mitochondrial division serves as a quality control mechanism to suppress oxidative damage and thus promote neuronal survival. PMID:22564413

  4. Mitochondrial division ensures the survival of postmitotic neurons by suppressing oxidative damage.

    PubMed

    Kageyama, Yusuke; Zhang, Zhongyan; Roda, Ricardo; Fukaya, Masahiro; Wakabayashi, Junko; Wakabayashi, Nobunao; Kensler, Thomas W; Reddy, P Hemachandra; Iijima, Miho; Sesaki, Hiromi

    2012-05-14

    Mitochondria divide and fuse continuously, and the balance between these two processes regulates mitochondrial shape. Alterations in mitochondrial dynamics are associated with neurodegenerative diseases. Here we investigate the physiological and cellular functions of mitochondrial division in postmitotic neurons using in vivo and in vitro gene knockout for the mitochondrial division protein Drp1. When mouse Drp1 was deleted in postmitotic Purkinje cells in the cerebellum, mitochondrial tubules elongated due to excess fusion, became large spheres due to oxidative damage, accumulated ubiquitin and mitophagy markers, and lost respiratory function, leading to neurodegeneration. Ubiquitination of mitochondria was independent of the E3 ubiquitin ligase parkin in Purkinje cells lacking Drp1. Treatment with antioxidants rescued mitochondrial swelling and cell death in Drp1KO Purkinje cells. Moreover, hydrogen peroxide converted elongated tubules into large spheres in Drp1KO fibroblasts. Our findings suggest that mitochondrial division serves as a quality control mechanism to suppress oxidative damage and thus promote neuronal survival.

  5. WldS and PGC-1α Regulate Mitochondrial Transport and Oxidation State after Axonal Injury

    PubMed Central

    O'Donnell, Kelley C.; Vargas, Mauricio E.

    2013-01-01

    Mitochondria carry out many of the processes implicated in maintaining axon health or causing axon degeneration, including ATP and reactive oxygen species (ROS) generation, as well as calcium buffering and protease activation. Defects in mitochondrial function and transport are common in axon degeneration, but how changes in specific mitochondrial properties relate to degeneration is not well understood. Using cutaneous sensory neurons of living larval zebrafish as a model, we examined the role of mitochondria in axon degeneration by monitoring mitochondrial morphology, transport, and redox state before and after laser axotomy. Mitochondrial transport terminated locally after injury in wild-type axons, an effect that was moderately attenuated by expressing the axon-protective fusion protein Wallerian degeneration slow (WldS). However, mitochondrial transport arrest eventually occurred in WldS-protected axons, indicating that later in the lag phase, mitochondrial transport is not required for axon protection. By contrast, the redox-sensitive biosensor roGFP2 was rapidly oxidized in the mitochondrial matrix after injury, and WldS expression prevented this effect, suggesting that stabilization of ROS production may mediate axon protection. Overexpression of PGC-1α, a transcriptional coactivator with roles in both mitochondrial biogenesis and ROS detoxification, dramatically increased mitochondrial density, attenuated roGFP2 oxidation, and delayed Wallerian degeneration. Collectively, these results indicate that mitochondrial oxidation state is a more reliable indicator of axon vulnerability to degeneration than mitochondrial motility. PMID:24027278

  6. Perinatal tobacco smoke exposure increases vascular oxidative stress and mitochondrial damage in non-human primates.

    PubMed

    Westbrook, David G; Anderson, Peter G; Pinkerton, Kent E; Ballinger, Scott W

    2010-09-01

    Epidemiological studies suggest that events occurring during fetal and early childhood development influence disease susceptibility. Similarly, molecular studies in mice have shown that in utero exposure to cardiovascular disease (CVD) risk factors such as environmental tobacco smoke (ETS) increased adult atherogenic susceptibility and mitochondrial damage; however, the molecular effects of similar exposures in primates are not yet known. To determine whether perinatal ETS exposure increased mitochondrial damage, dysfunction and oxidant stress in primates, archived tissues from the non-human primate model Macaca mulatta (M. mulatta) were utilized. M. mulatta were exposed to low levels of ETS (1 mg/m(3) total suspended particulates) from gestation (day 40) to early childhood (1 year), and aortic tissues were assessed for oxidized proteins (protein carbonyls), antioxidant activity (SOD), mitochondrial function (cytochrome oxidase), and mitochondrial damage (mitochondrial DNA damage). Results revealed that perinatal ETS exposure resulted in significantly increased oxidative stress, mitochondrial dysfunction and damage which were accompanied by significantly decreased mitochondrial antioxidant capacity and mitochondrial copy number in vascular tissue. Increased mitochondrial damage was also detected in buffy coat tissues in exposed M. mulatta. These studies suggest that perinatal tobacco smoke exposure increases vascular oxidative stress and mitochondrial damage in primates, potentially increasing adult disease susceptibility.

  7. The inborn errors of mitochondrial fatty acid oxidation.

    PubMed

    Vianey-Liaud, C; Divry, P; Gregersen, N; Mathieu, M

    1987-01-01

    To date, seven inborn errors of mitochondrial fatty acid oxidation have been identified. A total of about 100 patients in the world have been reported. Clinically the beta-oxidation defects are more often characterized by episodic hypoglycaemia leading to a coma mimicking Reye's syndrome. The hypoglycaemia is non-ketotic since the synthesis of ketone bodies is deficient. Periods of decompensation occur when carbohydrate supply is poor, e.g. prolonged fasting, vomiting, or increased caloric requirements, as and when lipid stores are used. Defects in beta-oxidation have also been reported to be one cause of sudden infant death syndrome. The diagnosis of these inborn errors is by biochemical investigation since where symptoms suggest such a defect, the precise aetiology cannot be assessed. The biochemical diagnosis is based firstly on identification of abnormal plasma and of urinary metabolites during acute attacks. Derivatives of the omega-oxidation and omega-1-oxidation of medium chain fatty acids have been identified, as well as acylglycine and acylcarnitine conjugates. These metabolites are nearly always absent when patients are in good clinical condition. Secondly, the diagnosis must be based on the identification of the enzymatic defects: this involves global assays which allow a localization of the 'level' of the defect (i.e. the oxidation of long, medium or short chain fatty acids) and specific measurement of enzyme activities (acyl-CoA dehydrogenases and electron carriers: ETF and ETF-DH). The diagnosis of these disorders is of prime importance because of the severity of the clinical symptoms. These can be prevented, in some cases, by an appropriate diet (a high carbohydrate, low fat diet, sometimes supplemented with L-carnitine). In other cases, genetic counselling can be offered.

  8. Chronic Arsenic Exposure-Induced Oxidative Stress is Mediated by Decreased Mitochondrial Biogenesis in Rat Liver.

    PubMed

    Prakash, Chandra; Kumar, Vijay

    2016-09-01

    The present study was executed to study the effect of chronic arsenic exposure on generation of mitochondrial oxidative stress and biogenesis in rat liver. Chronic sodium arsenite treatment (25 ppm for 12 weeks) decreased mitochondrial complexes activity in rat liver. There was a decrease in mitochondrial superoxide dismutase (MnSOD) activity in arsenic-treated rats that might be responsible for increased protein and lipid oxidation as observed in our study. The messenger RNA (mRNA) expression of mitochondrial and nuclear-encoded subunits of complexes I (ND1 and ND2) and IV (COX I and COX IV) was downregulated in arsenic-treated rats only. The protein and mRNA expression of MnSOD was reduced suggesting increased mitochondrial oxidative damage after arsenic treatment. There was activation of Bax and caspase-3 followed by release of cytochrome c from mitochondria suggesting induction of apoptotic pathway under oxidative stress. The entire phenomenon was associated with decrease in mitochondrial biogenesis as evident by decreased protein and mRNA expression of nuclear respiratory factor 1 (NRF-1), nuclear respiratory factor 2 (NRF-2), peroxisome proliferator activator receptor gamma-coactivator 1α (PGC-1α), and mitochondrial transcription factor A (Tfam) in arsenic-treated rat liver. The results of the present study indicate that arsenic-induced mitochondrial oxidative stress is associated with decreased mitochondrial biogenesis in rat liver that may present one of the mechanisms for arsenic-induced hepatotoxicity.

  9. Ceramides and mitochondrial fatty acid oxidation in obesity.

    PubMed

    Fucho, Raquel; Casals, Núria; Serra, Dolors; Herrero, Laura

    2017-04-01

    Obesity is an epidemic, complex disease that is characterized by increased glucose, lipids, and low-grade inflammation in the circulation, among other factors. It creates the perfect scenario for the production of ceramide, the building block of the sphingolipid family of lipids, which is involved in metabolic disorders such as obesity, diabetes, and cardiovascular disease. In addition, obesity causes a decrease in fatty acid oxidation (FAO), which contributes to lipid accumulation within the cells, conferring more susceptibility to cell dysfunction. C16:0 ceramide, a specific ceramide species, has been identified recently as the principal mediator of obesity-derived insulin resistance, impaired fatty acid oxidation, and hepatic steatosis. In this review, we have sought to cover the importance of the ceramide species and their metabolism, the main ceramide signaling pathways in obesity, and the link between C16:0 ceramide, FAO, and obesity.-Fucho, R., Casals, N., Serra, D., Herrero, L. Ceramides and mitochondrial fatty acid oxidation in obesity.

  10. Impaired Mitochondrial Fat Oxidation Induces FGF21 in Muscle.

    PubMed

    Vandanmagsar, Bolormaa; Warfel, Jaycob D; Wicks, Shawna E; Ghosh, Sujoy; Salbaum, J Michael; Burk, David; Dubuisson, Olga S; Mendoza, Tamra M; Zhang, Jingying; Noland, Robert C; Mynatt, Randall L

    2016-05-24

    Fatty acids are the primary fuel source for skeletal muscle during most of our daily activities, and impaired fatty acid oxidation (FAO) is associated with insulin resistance. We have developed a mouse model of impaired FAO by deleting carnitine palmitoyltransferase-1b specifically in skeletal muscle (Cpt1b(m-/-)). Cpt1b(m-/-) mice have increased glucose utilization and are resistant to diet-induced obesity. Here, we show that inhibition of mitochondrial FAO induces FGF21 expression specifically in skeletal muscle. The induction of FGF21 in Cpt1b-deficient muscle is dependent on AMPK and Akt1 signaling but independent of the stress signaling pathways. FGF21 appears to act in a paracrine manner to increase glucose uptake under low insulin conditions, but it does not contribute to the resistance to diet-induced obesity.

  11. Impaired mitochondrial fat oxidation induces FGF21 in muscle

    PubMed Central

    Vandanmagsar, Bolormaa; Warfel, Jaycob D.; Wicks, Shawna E.; Ghosh, Sujoy; Salbaum, J. Michael; Burk, David; Dubuisson, Olga S.; Mendoza, Tamra M.; Zhang, Jingying; Noland, Robert C.; Mynatt, Randall L.

    2016-01-01

    SUMMARY Fatty acids are the primary fuel source for skeletal muscle during most of our daily activities and impaired fatty acid oxidation (FAO) is associated with insulin resistance. We have developed a mouse model of impaired FAO by deleting carnitine palmitoyltransferase-1b specifically in skeletal muscle (Cpt1bm−/−). Cpt1bm−/− mice have increased glucose utilization and are resistant to diet induced obesity. Here we show that inhibition of mitochondrial FAO induces FGF21 expression specifically in skeletal muscle. The induction of FGF21 in Cpt1b-deficient muscle is dependent on AMPK and Akt1 signaling but independent on the stress signaling pathways. FGF21 appears to act in a paracrine manner to increase glucose uptake under low insulin conditions, but does not contribute to the resistance to diet induced obesity. PMID:27184848

  12. [Role of rotenone in mitochondrial oxidative damage and the underlying mechanisms].

    PubMed

    Deng, Yong; Lu, Jun

    2014-10-01

    Rotenone is one of the typical inhibitors of the complex I on the mitochondrial respiratory chain. Numerous studies showed when applied to live animals or cells, rotenone could lead to mitochondrial dysfunction, ROS augment, and thus oxidative damage to proteins, lipids and nucleic acids. Through exploring the process of ROS generation in mitochondria, the relationship between rotenone and mitochondrial ROS generation and the role of rotenone in DNA damage, we elucidated the mechanisms of rotenone induced-mitochondrial oxidative damage. At the same time, we attempted to explore the mtDNA damage and the mutation induced by rotenone.

  13. Quality control of oxidatively damaged mitochondrial proteins is mediated by p97 and the proteasome.

    PubMed

    Hemion, Charles; Flammer, Josef; Neutzner, Albert

    2014-10-01

    Protein quality control is essential for maintaining mitochondrial fidelity. Proteins damaged by reactive oxygen species necessitate quality control to prevent mitochondrial dysfunction connected to aging and neurodegeneration. Here we report a role for the AAA ATPase p97/VCP and the proteasome in the quality control of oxidized mitochondrial proteins under low oxidative stress as well as normal conditions. Proteasomal inhibition and blocking p97-dependent protein retrotranslocation interfered with degradation of oxidized mitochondrial proteins. Thus, ubiquitin-dependent, p97-, and proteasome-mediated degradation of oxidatively damaged proteins plays a key role in maintaining mitochondrial fidelity and is likely an important defense mechanism against aging and neurodegeneration. Copyright © 2014 Elsevier Inc. All rights reserved.

  14. Inhibitors of Mitochondrial Fission as a Therapeutic Strategy for Diseases with Oxidative Stress and Mitochondrial Dysfunction

    PubMed Central

    Reddy, P. Hemachandra

    2014-01-01

    Mitochondria are essential cytoplasmic organelles, critical for cell survival and death. Recent mitochondrial research revealed that mitochondrial dynamics – the balance of fission and fusion in normal mitochondrial dynamics – is an important cellular mechanism in eukaryotic cell and is involved in the maintenance of mitochondrial morphology, structure, number, distribution, and function. Research into mitochondria and cell function has revealed that mitochondrial dynamics is impaired in a large number of aging and neurodegenerative diseases, and in several inherited mitochondrial diseases, and that this impairment involves excessive mitochondrial fission, resulting in mitochondrial structural changes and dysfunction, and cell damage. Attempts have been made to develop molecules to reduce mitochondrial fission while maintaining normal mitochondrial fusion and function in those diseases that involve excessive mitochondrial fission. This review article discusses mechanisms of mitochondrial fission in normal and diseased states of mammalian cells and discusses research aimed at developing therapies, such as Mdivi, Dynasore and P110, to prevent or to inhibit excessive mitochondrial fission. PMID:24413616

  15. Tetramethylpyrazine protects palmitate-induced oxidative damage and mitochondrial dysfunction in C2C12 myotubes.

    PubMed

    Gao, Xin; Zhao, Xiao-long; Zhu, Yan-hui; Li, Xiao-mu; Xu, Qiong; Lin, Huan-dong; Wang, Ming-wei

    2011-04-25

    Tetramethylpyrazine (TMP), one of the active ingredients isolated from a Chinese herbal prescription, possesses protective effects against oxidative stress caused by high glucose in endothelial cells. In this study, the role of TMP in preventing muscle cells from palmitate-induced oxidative damage was investigated and the possible mechanisms of action elucidated. Mitochondrial reactive oxygen species (ROS) were measured in C2C12 myotubes, a palmitate-induced oxidative stress cell model, with or without TMP. Both mitochondrial membrane potential (MMP) and oxygen consumption were assessed in conjunction with quantification of mitochondrial DNA and mitochondrial biogenesis-related factors, such as peroxisome proliferator-activated receptor-γ coactivator 1 α (PGC1α), nuclear respiratory factor 1 (NRF1) and mitochondrial transcription factor A (Tfam), by real-time polymerase chain reaction. Expression of mitochondrial respiratory chain complex III as an index of mitochondrial function was evaluated by immunoblotting, and glucose transport into the C2C12 myotube examined by analyzing 2-deoxy-[(3)H]glucose uptake. TMP significantly alleviated palmitate-induced mitochondrial ROS production, mitigated mitochondrial dysfunction and increased D-loop mRNA expression as compared with the control. This was accompanied by a marked reversal of palmitate-induced down-regulation in the expression of mitochondrial biogenesis-related factors (PGC1α, NRF1 and Tfam) and decreased glucose uptake in C2C12 myotubes. As a result, cell respiration, as reflected by the elevated expression of mitochondrial respiratory chain complex III and oxygen consumption, was enhanced. TMP is capable of protecting C2C12 myotubes against palmitate-induced oxidative damage and mitochondrial dysfunction, and improving glucose uptake in muscle cells partially through the up-regulation of mitochondrial biogenesis. Copyright © 2011 Elsevier Inc. All rights reserved.

  16. Silica nanoparticles mediated neuronal cell death in corpus striatum of rat brain: implication of mitochondrial, endoplasmic reticulum and oxidative stress

    NASA Astrophysics Data System (ADS)

    Parveen, Arshiya; Rizvi, Syed Husain Mustafa; Mahdi, Farzana; Tripathi, Sandeep; Ahmad, Iqbal; Shukla, Rajendra K.; Khanna, Vinay K.; Singh, Ranjana; Patel, Devendra K.; Mahdi, Abbas Ali

    2014-11-01

    Extensive uses of silica nanoparticles (SiNPs) in biomedical and industrial fields have increased the risk of exposure, resulting concerns about their safety. We focussed on some of the safety aspects by studying neurobehavioural impairment, oxidative stress (OS), neurochemical and ultrastructural changes in corpus striatum (CS) of male Wistar rats exposed to 80-nm SiNPs. Moreover, its role in inducing mitochondrial and endoplasmic reticulum (ER) stress-mediated neuronal apoptosis was also investigated. The results demonstrated impairment in neurobehavioural indices, and a significant increase in lipid peroxide levels (LPO), hydrogen peroxide (H2O2), superoxide (O2 -) and protein carbonyl content, whereas there was a significant decrease in the activities of the enzymes, manganese superoxide dismutase (Mn SOD), glutathione peroxidase (GPx), catalase (CAT) and reduced glutathione (GSH) content, suggesting impaired antioxidant defence system. Protein (cytochrome c, Bcl-2, Bax, p53, caspase-3, caspase 12 and CHOP/Gadd153) and mRNA (Bcl-2, Bax, p53 and CHOP/Gadd153, cytochrome c) expression studies of mitochondrial and ER stress-related apoptotic factors suggested that both the cell organelles were involved in OS-mediated apoptosis in treated rat brain CS. Moreover, electron microscopic studies clearly showed mitochondrial and ER dysfunction. In conclusion, the result of the study suggested that subchronic SiNPs' exposure has the potential to alter the behavioural activity and also to bring about changes in biochemical, neurochemical and ultrastructural profiles in CS region of rat brain. Furthermore, we also report SiNPs-induced apoptosis in CS, through mitochondrial and ER stress-mediated signalling.

  17. Prevention of mitochondrial oxidative damage as a therapeutic strategy in diabetes.

    PubMed

    Green, Katherine; Brand, Martin D; Murphy, Michael P

    2004-02-01

    Hyperglycemia causes many of the pathological consequences of both type 1 and type 2 diabetes. Much of this damage is suggested to be a consequence of elevated production of reactive oxygen species by the mitochondrial respiratory chain during hyperglycemia. Mitochondrial radical production associated with hyperglycemia will also disrupt glucose-stimulated insulin secretion by pancreatic beta-cells, because pancreatic beta-cells are particularly susceptible to oxidative damage. Therefore, mitochondrial radical production in response to hyperglycemia contributes to both the progression and pathological complications of diabetes. Consequently, strategies to decrease mitochondrial radical production and oxidative damage may have therapeutic potential. This could be achieved by the use of antioxidants or by decreasing the mitochondrial membrane potential. Here, we outline the background to these strategies and discuss how antioxidants targeted to mitochondria, or selective mitochondrial uncoupling, may be potential therapies for diabetes.

  18. Mitochondrial fatty acid oxidation alterations in heart failure, ischaemic heart disease and diabetic cardiomyopathy

    PubMed Central

    Fillmore, N; Mori, J; Lopaschuk, G D

    2014-01-01

    Heart disease is a leading cause of death worldwide. In many forms of heart disease, including heart failure, ischaemic heart disease and diabetic cardiomyopathies, changes in cardiac mitochondrial energy metabolism contribute to contractile dysfunction and to a decrease in cardiac efficiency. Specific metabolic changes include a relative increase in cardiac fatty acid oxidation rates and an uncoupling of glycolysis from glucose oxidation. In heart failure, overall mitochondrial oxidative metabolism can be impaired while, in ischaemic heart disease, energy production is impaired due to a limitation of oxygen supply. In both of these conditions, residual mitochondrial fatty acid oxidation dominates over mitochondrial glucose oxidation. In diabetes, the ratio of cardiac fatty acid oxidation to glucose oxidation also increases, although primarily due to an increase in fatty acid oxidation and an inhibition of glucose oxidation. Recent evidence suggests that therapeutically regulating cardiac energy metabolism by reducing fatty acid oxidation and/or increasing glucose oxidation can improve cardiac function of the ischaemic heart, the failing heart and in diabetic cardiomyopathies. In this article, we review the cardiac mitochondrial energy metabolic changes that occur in these forms of heart disease, what role alterations in mitochondrial fatty acid oxidation have in contributing to cardiac dysfunction and the potential for targeting fatty acid oxidation to treat these forms of heart disease. LINKED ARTICLES This article is part of a themed issue on Mitochondrial Pharmacology: Energy, Injury & Beyond. To view the other articles in this issue visit http://dx.doi.org/10.1111/bph.2014.171.issue-8 PMID:24147975

  19. Fructose induces mitochondrial dysfunction and triggers apoptosis in skeletal muscle cells by provoking oxidative stress.

    PubMed

    Jaiswal, Natasha; Maurya, Chandan K; Arha, Deepti; Avisetti, Deepa R; Prathapan, Ayyappan; Raj, Palayyan S; Raghu, Kozhiparambil G; Kalivendi, Shasi V; Tamrakar, Akhilesh Kumar

    2015-07-01

    Mitochondrial dysfunction in skeletal muscle has been implicated in the development of insulin resistance, a major characteristic of type 2 diabetes. There is evidence that oxidative stress results from the increased production of reactive oxygen species and reactive nitrogen species leads to mitochondrial dysfunction, tissue damage, insulin resistance, and other complications observed in type 2 diabetes. It has been suggested that intake of high fructose contributes to insulin resistance and other metabolic disturbances. However, there is limited information about the direct effect of fructose on the mitochondrial function of skeletal muscle, the major metabolic determinant of whole body insulin activity. Here, we assessed the effect of fructose exposure on mitochondria-mediated mechanisms in skeletal muscle cells. Exposure of L6 myotubes to high fructose stimulated the production of mitochondrial reactive oxygen species and nitric oxide (NO), and the expression of inducible NO synthase. Fructose-induced oxidative stress was associated with increased translocation of nuclear factor erythroid 2-related factor-2 to the nucleus, decreases in mitochondrial DNA content and mitochondrial dysfunctions, as evidenced by decreased activities of citrate synthase and mitochondrial dehydrogenases, loss of mitochondrial membrane potential, decreased activity of the mitochondrial respiratory complexes, and impaired mitochondrial energy metabolism. Furthermore, positive Annexin-propidium iodide staining and altered expression of Bcl-2 family members and caspases in L6 myotubes indicated that the cells progressively became apoptotic upon fructose exposure. Taken together, these findings suggest that exposure of skeletal muscle cells to fructose induced oxidative stress that decreased mitochondrial DNA content and triggered mitochondrial dysfunction, which caused apoptosis.

  20. Carotid body O2 chemoreception and mitochondrial oxidative phosphorylation.

    PubMed

    Mulligan, E; Lahiri, S; Storey, B T

    1981-08-01

    The effect on carotid chemoreceptor afferents of oligomycin, an inhibitor of mitochondrial oxidative phosphorylation that does not affect energy conservation, was studied in 20 cats that were anesthetized, paralyzed, and artificially ventilated. Responses of single or a few chemoreceptor afferents to changes in arterial O2 tension (PaO2) at constant arterial CO2 tension were recorded. In addition, responses to nicotine, cyanide, and antimycin A or carbonyl cyanide p-tri-fluoromethoxyphenylhydrazone (FCCP) were tested in normoxia. Oligomycin (50-500 microgram) was administered by close intra-arterial injection, and the same tests were repeated at timed intervals. Initially, oligomycin caused vigorous stimulation of carotid chemoreceptor activity. Subsequently, although the afferent fibers were still active and could be vigorously stimulated by nicotine, they no longer responded to changes in PaO2 or to doses of cyanide, antimycin A, or FCCP. These results separate stimulation of chemoreceptor afferents by hypoxia and metabolic inhibitors and uncouplers from that by nicotine and suggest that intact oxidative phosphorylation, required for maintenance of the intracellular high-energy phosphate levels, forms the basis of O2 chemoreception in the carotid body.

  1. Importance of mitochondrial dysfunction in oxidative stress response: A comparative study of gene expression profiles.

    PubMed

    Shibanuma, Motoko; Inoue, Anna; Ushida, Kyota; Uchida, Tetsu; Ishikawa, Fumihiro; Mori, Kazunori; Nose, Kiyoshi

    2011-06-01

    Mitochondria are considered to play an important role in oxidative stress response since they are a source of reactive oxygen species and are also targeted by these species. This study examined the mitochondrial conditions in cells of epithelial origin that were exposed to H(2)O(2) and found a decline in the membrane potential along with a specific loss of UQCRC1, a sub-unit of complex III, suggesting that mitochondrial dysfunction occurs upon exposure to oxidative stress. This observation led to the hypothesis that certain cellular responses to oxidative stress occurred because of mitochondrial dysfunction. When mitochondria-less (pseudo ρ0) cells were examined as a model of mitochondrial dysfunction, striking similarities were found in their cellular responses compared with those found in cells exposed to oxidative stress, including changes in gene expression and gelatinolytic enzyme activities, thus suggesting that cellular responses to oxidative stress were partly mediated by mitochondrial dysfunction. This possibility was further validated by microarray analysis, which suggested that almost one-fourth of the cellular responses to oxidative stress were mediated by mitochondrial dysfunction that accompanies oxidative stress, thereby warranting a therapeutic strategy that targets mitochondria for the treatment of oxidative stress-associated diseases.

  2. Oxidative stress modulates mitochondrial failure and cyclophilin D function in X-linked adrenoleukodystrophy.

    PubMed

    López-Erauskin, Jone; Galino, Jorge; Bianchi, Patrizia; Fourcade, Stéphane; Andreu, Antoni L; Ferrer, Isidre; Muñoz-Pinedo, Cristina; Pujol, Aurora

    2012-12-01

    A common process associated with oxidative stress and severe mitochondrial impairment is the opening of the mitochondrial permeability transition pore, as described in many neurodegenerative diseases. Thus, inhibition of mitochondrial permeability transition pore opening represents a potential target for inhibiting mitochondrial-driven cell death. Among the mitochondrial permeability transition pore components, cyclophilin D is the most studied and has been found increased under pathological conditions. Here, we have used in vitro and in vivo models of X-linked adrenoleukodystrophy to investigate the relationship between the mitochondrial permeability transition pore opening and redox homeostasis. X-linked adrenoleukodystrophy is a neurodegenerative condition caused by loss of function of the peroxisomal ABCD1 transporter, in which oxidative stress plays a pivotal role. In this study, we provide evidence of impaired mitochondrial metabolism in a peroxisomal disease, as fibroblasts in patients with X-linked adrenoleukodystrophy cannot survive when forced to rely on mitochondrial energy production, i.e. on incubation in galactose. Oxidative stress induced under galactose conditions leads to mitochondrial damage in the form of mitochondrial inner membrane potential dissipation, ATP drop and necrotic cell death, together with increased levels of oxidative modifications in cyclophilin D protein. Moreover, we show increased expression levels of cyclophilin D in the affected zones of brains in patients with adrenomyeloneuropathy, in spinal cord of a mouse model of X-linked adrenoleukodystrophy (Abcd1-null mice) and in fibroblasts from patients with X-linked adrenoleukodystrophy. Notably, treatment with antioxidants rescues mitochondrial damage markers in fibroblasts from patients with X-linked adrenoleukodystrophy, including cyclophilin D oxidative modifications, and reverses cyclophilin D induction in vitro and in vivo. These findings provide mechanistic insight into the

  3. Oxidative stress modulates mitochondrial failure and cyclophilin D function in X-linked adrenoleukodystrophy

    PubMed Central

    López-Erauskin, Jone; Galino, Jorge; Bianchi, Patrizia; Fourcade, Stéphane; Andreu, Antoni L.; Ferrer, Isidre; Muñoz-Pinedo, Cristina

    2012-01-01

    A common process associated with oxidative stress and severe mitochondrial impairment is the opening of the mitochondrial permeability transition pore, as described in many neurodegenerative diseases. Thus, inhibition of mitochondrial permeability transition pore opening represents a potential target for inhibiting mitochondrial-driven cell death. Among the mitochondrial permeability transition pore components, cyclophilin D is the most studied and has been found increased under pathological conditions. Here, we have used in vitro and in vivo models of X-linked adrenoleukodystrophy to investigate the relationship between the mitochondrial permeability transition pore opening and redox homeostasis. X-linked adrenoleukodystrophy is a neurodegenerative condition caused by loss of function of the peroxisomal ABCD1 transporter, in which oxidative stress plays a pivotal role. In this study, we provide evidence of impaired mitochondrial metabolism in a peroxisomal disease, as fibroblasts in patients with X-linked adrenoleukodystrophy cannot survive when forced to rely on mitochondrial energy production, i.e. on incubation in galactose. Oxidative stress induced under galactose conditions leads to mitochondrial damage in the form of mitochondrial inner membrane potential dissipation, ATP drop and necrotic cell death, together with increased levels of oxidative modifications in cyclophilin D protein. Moreover, we show increased expression levels of cyclophilin D in the affected zones of brains in patients with adrenomyeloneuropathy, in spinal cord of a mouse model of X-linked adrenoleukodystrophy (Abcd1-null mice) and in fibroblasts from patients with X-linked adrenoleukodystrophy. Notably, treatment with antioxidants rescues mitochondrial damage markers in fibroblasts from patients with X-linked adrenoleukodystrophy, including cyclophilin D oxidative modifications, and reverses cyclophilin D induction in vitro and in vivo. These findings provide mechanistic insight into the

  4. Uncoupling of mitochondrial oxidative phosphorylation by DNA gyrase inhibitors

    SciTech Connect

    Gallagher, M.; Weinberg, R.; Simpson, M.V.

    1986-05-01

    Supercoiled mtDNA and the swivel requirement for its replication suggest the existence of a mtDNA gyrase. The authors published studies on isolated mitochondria showing that novobiocin, coumermycin, nalidixic acid, and oxolinic acid promote relaxed DNA formation at the expense of supercoiled DNA are in accord with this view. However, their inability to directly detect the enzyme led them to ask whether these drugs act elsewhere. Their results with isolated rat liver mitochondria show that novo, nal, but not oxo, stimulate O/sub 2/ uptake as much as does 2.4-dinitrophenol (DNP). This possible uncoupling effect was confirmed by a standard (/sup 32/P) assay showing the following inhibitions of ATP synthesis: 0.2 mM novo, 95% (0.4 mM, 100%) 0.4 mM nal, 37%; oxo to at least 1.9 mM, 0%; (0.5 mM 2,4-DNP, 100%). Thus, oxo remains a useful tool for intact mitochondrial studies. Because these three drugs, especially novo, are being used to study the role of DNA superhelicity on pro- and eucaryotic (and mitochondrial) gene expression, the authors studied their effect on oxidative phosphorylation in such cells. In these cases the drugs did not affect DNP-sensitive (/sup 14/C)glutamine transport into E. coli cells (an established measure of ATP level), nor, in an S. cerevisiae mutant permeable to novo, did novo affect the steady state ATP level. Studies on cultured mammalian cells are in progress.

  5. Resolution of mitochondrial oxidant stress improves aged-cardiovascular performance

    PubMed Central

    Owada, Takashi; Yamauchi, Hiroyuki; Miura, Shunsuke; Machii, Hirofumi; Takeishi, Yasuchika

    2017-01-01

    Background Senescence is a major factor that increases oxidative stress in mitochondria, which contributes toward the pathogenesis of heart disease. However, the effect of antioxidant therapy on cardiac mitochondria in aged-cardiac performance remains elusive. Objectives We postulated that the mitochondrial targeting of superoxide scavenging would have benefits in the aged heart. Methods and results Generation of superoxide in the mitochondria and nicotinamide adenine dinucleotide phosphate oxidase activity increased in the heart of old mice compared with that in young mice. In old mice treated with a mitochondria-targeted antioxidant MitoTEMPO (180 µg/kg/day, 28 days) co-infusion using a subcutaneously implanted minipump, levels of superoxide in the mitochondria and nicotinamide adenine dinucleotide phosphate oxidase activity as well as hydrogen peroxide decreased markedly in cardiomyocytes. Treatment with MitoTEMPO in old mice improved the systolic and diastolic function assessed by echocardiography. Endothelium-dependent vasodilation in isolated coronary arteries and endothelial nitric-oxide synthase phosphorylation were impaired in old mice compared with that in young mice and were improved by MitoTEMPO treatment. Mitochondria from the old mice myocardium showed lower rates of complex I-dependent and II-dependent respiration compared with that from young mice. Supplementation of MitoTEMPO in old mice improved the respiration rates and efficiency of ATP generation in mitochondria to a level similar to that of young mice. Conclusion Resolution of oxidative stress in mitochondria by MitoTEMPO in old mice restored cardiac function and the capacity of coronary vasodilation to the same magnitude observed in young mice. An antioxidant strategy targeting mitochondria could have a therapeutic benefit in heart disease with senescence. PMID:27740971

  6. Retinol binding protein 4 induces mitochondrial dysfunction and vascular oxidative damage.

    PubMed

    Wang, Jingjing; Chen, Hongen; Liu, Yan; Zhou, Wenjing; Sun, Ruifang; Xia, Min

    2015-06-01

    Mitochondrial dysfunction has been implicated in cardiovascular diseases. Elevation of serum retinol binding protein 4 (RBP4) in patients has been linked to cardiovascular disease. However, the role of RBP4 on mitochondrial oxidative stress and vascular oxidative damage is not well demonstrated. Therefore, we evaluated the impact of RBP4 on the mitochondrial reactive oxygen species (ROS) and dynamics in the pathogenesis of cardiovascular diseases. RBP4 treatment increased mitochondrial superoxide generation in a dose-dependent manner in human aortic endothelial cells (HAECs). Exposure to RBP4 also promoted mitochondrial dysfunction as determined by decreased mitochondrial content and integrity as well as membrane potential in HAECs. Incubation with RBP4 suppressed mitofusin (Mfn)-1 protein expression, but enhanced dynamin-related protein-1 (Drp1) and fission-1 (Fis1) protein expression in HAECs, suggesting an impairment of mitochondrial fusion and fission dynamics. Moreover, RBP4 treatment significantly induced endothelial apoptosis, increased the expression of Cytochrome C and Bax, but decreased the expression of Bcl-2. Furthermore, RBP4 stimulation suppressed phosphatidyl inositol 3-kinase (PI3K)/Akt signaling in HAECs. Finally, RBP4-Tg mice exhibited severe mitochondrial dysfunction and vascular oxidative damage in aorta compared with wide-type C57BL/6J mice. The present study uncovers a novel mechanism through which RBP4 induces vascular oxidative damage and accelerates the development of atherosclerosis. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  7. Thiol-based antioxidants elicit mitochondrial oxidation via respiratory complex III

    PubMed Central

    Beaudoin, Jessica N.; Ponnuraj, Nagendraprabhu; DiLiberto, Stephen J.; Hanafin, William P.; Kenis, Paul J. A.; Gaskins, H. Rex

    2015-01-01

    Excessive oxidation is widely accepted as a precursor to deleterious cellular function. On the other hand, an awareness of the role of reductive stress as a similar pathological insult is emerging. Here we report early dynamic changes in compartmentalized glutathione (GSH) redox potentials in living cells in response to exogenously supplied thiol-based antioxidants. Noninvasive monitoring of intracellular thiol-disulfide exchange via a genetically encoded biosensor targeted to cytosol and mitochondria revealed unexpectedly rapid oxidation of the mitochondrial matrix in response to GSH ethyl ester or N-acetyl-l-cysteine. Oxidation of the probe occurred within seconds in a concentration-dependent manner and was attenuated with the membrane-permeable ROS scavenger tiron. In contrast, the cytosolic sensor did not respond to similar treatments. Surprisingly, the immediate mitochondrial oxidation was not abrogated by depolarization of mitochondrial membrane potential or inhibition of mitochondrial GSH uptake. After detection of elevated levels of mitochondrial ROS, we systematically inhibited multisubunit protein complexes of the mitochondrial respiratory chain and determined that respiratory complex III is a downstream target of thiol-based compounds. Disabling complex III with myxothiazol completely blocked matrix oxidation induced with GSH ethyl ester or N-acetyl-l-cysteine. Our findings provide new evidence of a functional link between exogenous thiol-containing antioxidants and mitochondrial respiration. PMID:25994788

  8. Perm1 enhances mitochondrial biogenesis, oxidative capacity, and fatigue resistance in adult skeletal muscle.

    PubMed

    Cho, Yoshitake; Hazen, Bethany C; Gandra, Paulo G; Ward, Samuel R; Schenk, Simon; Russell, Aaron P; Kralli, Anastasia

    2016-02-01

    Skeletal muscle mitochondrial content and oxidative capacity are important determinants of muscle function and whole-body health. Mitochondrial content and function are enhanced by endurance exercise and impaired in states or diseases where muscle function is compromised, such as myopathies, muscular dystrophies, neuromuscular diseases, and age-related muscle atrophy. Hence, elucidating the mechanisms that control muscle mitochondrial content and oxidative function can provide new insights into states and diseases that affect muscle health. In past studies, we identified Perm1 (PPARGC1- and ESRR-induced regulator, muscle 1) as a gene induced by endurance exercise in skeletal muscle, and regulating mitochondrial oxidative function in cultured myotubes. The capacity of Perm1 to regulate muscle mitochondrial content and function in vivo is not yet known. In this study, we use adeno-associated viral (AAV) vectors to increase Perm1 expression in skeletal muscles of 4-wk-old mice. Compared to control vector, AAV1-Perm1 leads to significant increases in mitochondrial content and oxidative capacity (by 40-80%). Moreover, AAV1-Perm1-transduced muscles show increased capillary density and resistance to fatigue (by 33 and 31%, respectively), without prominent changes in fiber-type composition. These findings suggest that Perm1 selectively regulates mitochondrial biogenesis and oxidative function, and implicate Perm1 in muscle adaptations that also occur in response to endurance exercise. © FASEB.

  9. Evaluation of the mitochondrial respiratory chain and oxidative phosphorylation system using blue native gel electrophoresis.

    PubMed

    Díaz, Francisca; Barrientos, Antoni; Fontanesi, Flavia

    2009-10-01

    The oxidative phosphorylation (OXPHOS) system consists of five multimeric complexes embedded in the mitochondrial inner membrane. They work in concert to drive the aerobic synthesis of ATP. Mitochondrial and nuclear DNA mutations affecting the accumulation and function of these enzymes are the most common cause of mitochondrial diseases and have also been associated with neurodegeneration and aging. For this reason, several approaches for the assessment of the OXPHOS system enzymes have been progressively developed. Based on methods described elsewhere, the use of blue native gel electrophoresis (BNGE) techniques to routinely assess the OXPHOS system and screen for enzymatic defects in homogenates or mitochondrial preparations from tissues or cultured cells is described here.

  10. Catechin and epicatechin reduce mitochondrial dysfunction and oxidative stress induced by amiodarone in human lung fibroblasts.

    PubMed

    Silva Santos, Luciana Fernandes; Stolfo, Adriana; Calloni, Caroline; Salvador, Mirian

    2017-06-01

    Amiodarone (AMD) and its metabolite N-desethylamiodarone can cause some adverse effects, which include pulmonary toxicity. Some studies suggest that mitochondrial dysfunction and oxidative stress may play a role in these adverse effects. Catechin and epicatechin are recognized as important phenolic compounds with the ability to decrease oxidative stress. Therefore, the aim of this study was to evaluate the potential of catechin and epicatechin to modulate mitochondrial dysfunction and oxidative damage caused by AMD in human lung fibroblast cells (MRC-5). Mitochondrial dysfunction was assessed through the activity of mitochondrial complex I and ATP biosynthesis. Cell viability was evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Superoxide dismutase and catalase activity were measured spectrophotometrically at 480 and 240 nm, respectively. Lipid and protein oxidative levels were determined by thiobarbituric reactive substances and protein carbonyl assays, respectively. Nitric oxide (NO) levels were evaluated using the Griess reaction method. AMD was able to inhibit the activity of mitochondrial complex I and ATP biosynthesis in MRC-5 cells. Lipid and protein oxidative markers increased along with cell death, while superoxide dismutase and catalase activities and NO production decreased with AMD treatment. Both catechin and epicatechin circumvented mitochondrial dysfunction, thereby restoring the activity of mitochondrial complex I and ATP biosynthesis. Furthermore, the phenolic compounds were able to restore the imbalance in superoxide dismutase and catalase activities as well as the decrease in NO levels induced by AMD. Protein and lipid oxidative damage and cell death were reduced by catechin and epicatechin in AMD-treated cells. Catechin and epicatechin reduced mitochondrial dysfunction and oxidative stress caused by AMD in MRC-5 cells.

  11. Oxidative stress, cardiolipin and mitochondrial dysfunction in nonalcoholic fatty liver disease.

    PubMed

    Paradies, Giuseppe; Paradies, Valeria; Ruggiero, Francesca M; Petrosillo, Giuseppe

    2014-10-21

    Nonalcoholic fatty liver disease (NAFLD) is today considered the most common form of chronic liver disease, affecting a high proportion of the population worldwide. NAFLD encompasses a large spectrum of liver damage, ranging from simple steatosis to steatohepatitis, advanced fibrosis and cirrhosis. Obesity, hyperglycemia, type 2 diabetes and hypertriglyceridemia are the most important risk factors. The pathogenesis of NAFLD and its progression to fibrosis and chronic liver disease is still unknown. Accumulating evidence indicates that mitochondrial dysfunction plays a key role in the physiopathology of NAFLD, although the mechanisms underlying this dysfunction are still unclear. Oxidative stress is considered an important factor in producing lethal hepatocyte injury associated with NAFLD. Mitochondrial respiratory chain is the main subcellular source of reactive oxygen species (ROS), which may damage mitochondrial proteins, lipids and mitochondrial DNA. Cardiolipin, a phospholipid located at the level of the inner mitochondrial membrane, plays an important role in several reactions and processes involved in mitochondrial bioenergetics as well as in mitochondrial dependent steps of apoptosis. This phospholipid is particularly susceptible to ROS attack. Cardiolipin peroxidation has been associated with mitochondrial dysfunction in multiple tissues in several physiopathological conditions, including NAFLD. In this review, we focus on the potential roles played by oxidative stress and cardiolipin alterations in mitochondrial dysfunction associated with NAFLD.

  12. Lycopene Prevents Amyloid [Beta]-Induced Mitochondrial Oxidative Stress and Dysfunctions in Cultured Rat Cortical Neurons.

    PubMed

    Qu, Mingyue; Jiang, Zheng; Liao, Yuanxiang; Song, Zhenyao; Nan, Xinzhong

    2016-06-01

    Brains affected by Alzheimer's disease (AD) show a large spectrum of mitochondrial alterations at both morphological and genetic level. The causal link between β-amyloid (Aβ) and mitochondrial dysfunction has been established in cellular models of AD. We observed previously that lycopene, a member of the carotenoid family of phytochemicals, could counteract neuronal apoptosis and cell damage induced by Aβ and other neurotoxic substances, and that this neuroprotective action somehow involved the mitochondria. The present study aims to investigate the effects of lycopene on mitochondria in cultured rat cortical neurons exposed to Aβ. It was found that lycopene attenuated Aβ-induced oxidative stress, as evidenced by the decreased intracellular reactive oxygen species generation and mitochondria-derived superoxide production. Additionally, lycopene ameliorated Aβ-induced mitochondrial morphological alteration, opening of the mitochondrial permeability transition pores and the consequent cytochrome c release. Lycopene also improved mitochondrial complex activities and restored ATP levels in Aβ-treated neuron. Furthermore, lycopene prevented mitochondrial DNA damages and improved the protein level of mitochondrial transcription factor A in mitochondria. Those results indicate that lycopene protects mitochondria against Aβ-induced damages, at least in part by inhibiting mitochondrial oxidative stress and improving mitochondrial function. These beneficial effects of lycopene may account for its protection against Aβ-induced neurotoxicity.

  13. Oxidative stress, cardiolipin and mitochondrial dysfunction in nonalcoholic fatty liver disease

    PubMed Central

    Paradies, Giuseppe; Paradies, Valeria; Ruggiero, Francesca M; Petrosillo, Giuseppe

    2014-01-01

    Nonalcoholic fatty liver disease (NAFLD) is today considered the most common form of chronic liver disease, affecting a high proportion of the population worldwide. NAFLD encompasses a large spectrum of liver damage, ranging from simple steatosis to steatohepatitis, advanced fibrosis and cirrhosis. Obesity, hyperglycemia, type 2 diabetes and hypertriglyceridemia are the most important risk factors. The pathogenesis of NAFLD and its progression to fibrosis and chronic liver disease is still unknown. Accumulating evidence indicates that mitochondrial dysfunction plays a key role in the physiopathology of NAFLD, although the mechanisms underlying this dysfunction are still unclear. Oxidative stress is considered an important factor in producing lethal hepatocyte injury associated with NAFLD. Mitochondrial respiratory chain is the main subcellular source of reactive oxygen species (ROS), which may damage mitochondrial proteins, lipids and mitochondrial DNA. Cardiolipin, a phospholipid located at the level of the inner mitochondrial membrane, plays an important role in several reactions and processes involved in mitochondrial bioenergetics as well as in mitochondrial dependent steps of apoptosis. This phospholipid is particularly susceptible to ROS attack. Cardiolipin peroxidation has been associated with mitochondrial dysfunction in multiple tissues in several physiopathological conditions, including NAFLD. In this review, we focus on the potential roles played by oxidative stress and cardiolipin alterations in mitochondrial dysfunction associated with NAFLD. PMID:25339807

  14. Mitochondrial Sirt3 supports cell proliferation by regulating glutamine-dependent oxidation in renal cell carcinoma

    SciTech Connect

    Choi, Jieun; Koh, Eunjin; Lee, Yu Shin; Lee, Hyun-Woo; Kang, Hyeok Gu; Yoon, Young Eun; Han, Woong Kyu; Choi, Kyung Hwa; Kim, Kyung-Sup

    2016-06-03

    Clear cell renal carcinoma (RCC), the most common malignancy arising in the adult kidney, exhibits increased aerobic glycolysis and low mitochondrial respiration due to von Hippel-Lindau gene defects and constitutive hypoxia-inducible factor-α expression. Sirt3 is a major mitochondrial deacetylase that mediates various types of energy metabolism. However, the role of Sirt3 as a tumor suppressor or oncogene in cancer depends on cell types. We show increased Sirt3 expression in the mitochondrial fraction of human RCC tissues. Sirt3 depletion by lentiviral short-hairpin RNA, as well as the stable expression of the inactive mutant of Sirt3, inhibited cell proliferation and tumor growth in xenograft nude mice, respectively. Furthermore, mitochondrial pyruvate, which was used for oxidation in RCC, might be derived from glutamine, but not from glucose and cytosolic pyruvate, due to depletion of mitochondrial pyruvate carrier and the relatively high expression of malic enzyme 2. Depletion of Sirt3 suppressed glutamate dehydrogenase activity, leading to impaired mitochondrial oxygen consumption. Our findings suggest that Sirt3 plays a tumor-progressive role in human RCC by regulating glutamine-derived mitochondrial respiration, particularly in cells where mitochondrial usage of cytosolic pyruvate is severely compromised. -- Highlights: •Sirt3 is required for the maintenance of RCC cell proliferation. •Mitochondrial usage of cytosolic pyruvate is severely compromised in RCC. •Sirt3 supports glutamine-dependent oxidation in RCC.

  15. Photosynthetic water oxidation vs. mitochondrial oxygen reduction: distinct mechanistic parallels.

    PubMed

    Silverstein, Todd P

    2011-08-01

    The photosynthetic oxygen evolving complex (PSII-OEC) and the mitochondrial cytochrome c oxidase (CcO) not only catalyze anti-parallel reactions (the OEC oxidizes water to dioxygen, whereas CcO reduces dioxygen to water), they also share a number of uncanny molecular and mechanistic similarities. Both feature a redox-active polymetallic cluster that includes a key tyrosine, and both utilize a two-phase mechanism. In one phase the polymetallic cluster undergoes four sequential one-electron transfers: In the PSII-OEC, four successive photooxidations of the photosystem II reaction center P680 (to P680(+)) allows acceptance of 4 × 1e- from the Mn(4)Ca cluster; in CcO, four reduced cytochrome c Fe(2+) cations donate 4 × 1e- to the bimetallic center. In the second phase for each enzyme, the polymetallic cluster undergoes a single four-electron transfer with the O(2)/2 H(2)O redox couple. Intriguing mechanistic similarities between these two complex redox enzymes first delineated over a decade ago by Hoganson/Proshlyakov/Babcock et al. are updated and expanded in this article.

  16. Mitochondrial Oxidative Phosphorylation System (OXPHOS) Deficits in Schizophrenia

    PubMed Central

    Bergman, Oded

    2016-01-01

    Mitochondria are key players in the generation and regulation of cellular bioenergetics, producing the majority of adenosine triphosphate molecules by the oxidative phosphorylation system (OXPHOS). Linked to numerous signaling pathways and cellular functions, mitochondria, and OXPHOS in particular, are involved in neuronal development, connectivity, plasticity, and differentiation. Impairments in a variety of mitochondrial functions have been described in different general and psychiatric disorders, including schizophrenia (SCZ), a severe, chronic, debilitating illness that heavily affects the lives of patients and their families. This article reviews findings emphasizing the role of OXPHOS in the pathophysiology of SCZ. Evidence accumulated during the past few decades from imaging, transcriptomic, proteomic, and metabolomic studies points at OXPHOS deficit involvement in SCZ. Abnormalities have been reported in high-energy phosphates generated by the OXPHOS, in the activity of its complexes and gene expression, primarily of complex I (CoI). In addition, cellular signaling such as cAMP/protein kinase A (PKA) and Ca+2, neuronal development, connectivity, and plasticity have been linked to OXPHOS function and are reported to be impaired in SCZ. Finally, CoI has been shown as a site of interaction for both dopamine (DA) and antipsychotic drugs, further substantiating its role in the pathology of SCZ. Understanding the role of mitochondria and the OXPHOS in particular may encourage new insights into the pathophysiology and etiology of this debilitating disorder. PMID:27412728

  17. Targeting oxidative stress attenuates malonic acid induced Huntington like behavioral and mitochondrial alterations in rats.

    PubMed

    Kalonia, Harikesh; Kumar, Puneet; Kumar, Anil

    2010-05-25

    Objective of the present study was to explore the possible role of oxidative stress in the malonic acid induced behavioral, biochemical and mitochondrial alterations in rats. In the present study, unilateral single injections of malonic acid at different doses (1.5, 3 and 6 micromol) were made into the ipsilateral striatum in rats. Behavioral parameters were accessed on 1st, 7th and 14th day post malonic acid administration. Oxidative stress parameters and mitochondrial enzyme functions were assessed on day 14 after behavioral observations. Ipsilateral striatal malonic acid (3 and 6 micromol) administration significantly reduced body weight, locomotor activity, motor coordination and caused oxidative damage (lipid peroxidation, nitrite, superoxide dismutase, catalase and glutathione) in the striatum as compared to sham treated animal. Mitochondrial enzyme complexes and MTT (3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolinium bromide) activity were significantly inhibited by malonic acid. Vitamin E treatment (50 and 100 mg/kg, p.o.) significantly reversed the various behavioral, biochemical and mitochondrial alterations in malonic acid treated animals. Our findings show that targeting oxidative stress by vitamin E in malonic acid model, results in amelioration of behavioral and mitochondrial alterations are linked to inhibition of oxidative damage. Based upon these finding present study hypothesize that protection exerted by vitamin E on behavioral, mitochondrial markers indicates the possible preservation of the functional status of the striatal neurons by targeting the deleterious actions of oxidative stress.

  18. An update on the role of mitochondrial α-ketoglutarate dehydrogenase in oxidative stress

    PubMed Central

    Starkov, Anatoly A.

    2012-01-01

    The activity of mitochondrial alpha-ketoglutarate dehydrogenase complex (KGDHC) is severely reduced in human pathologies where oxidative stress is traditionally thought to play an important role, such as familial and sporadic forms of Alzheimer's disease and other age-related neurodegenerative diseases. This minireview is focused on substantial data that were accumulated over the last 2 decades to support the concept that KGDHC can be a primary mitochondrial target of oxidative stress and at the same time a key contributor to it by producing reactive oxygen species. This article is part of a Special Issue entitled ‘Mitochondrial function’. PMID:22820180

  19. An update on the role of mitochondrial α-ketoglutarate dehydrogenase in oxidative stress.

    PubMed

    Starkov, Anatoly A

    2013-07-01

    The activity of mitochondrial alpha-ketoglutarate dehydrogenase complex (KGDHC) is severely reduced in human pathologies where oxidative stress is traditionally thought to play an important role, such as familial and sporadic forms of Alzheimer's disease and other age-related neurodegenerative diseases. This minireview is focused on substantial data that were accumulated over the last 2 decades to support the concept that KGDHC can be a primary mitochondrial target of oxidative stress and at the same time a key contributor to it by producing reactive oxygen species. This article is part of a Special Issue entitled 'Mitochondrial function and dysfunction in neurodegeneration'. Copyright © 2012 Elsevier Inc. All rights reserved.

  20. Resveratrol improves high-fat diet induced insulin resistance by rebalancing subsarcolemmal mitochondrial oxidation and antioxidantion.

    PubMed

    Haohao, Zhang; Guijun, Qin; Juan, Zheng; Wen, Kong; Lulu, Chen

    2015-03-01

    Although resveratrol (RES) is thought to be a key regulator of insulin sensitivity in rodents, the exact mechanism underlying this effect remains unclear. Therefore, we sought to investigate how RES affects skeletal muscle oxidative and antioxidant levels of subsarcolemmal (SS) and intermyofibrillar (IMF) mitochondrial populations in high-fat diet (HFD)-induced insulin resistance (IR) rats. Systemic and skeletal muscle insulin sensitivity together with expressions of several genes related to mitochondrial biogenesis and skeletal muscle SIRT1, SIRT3 protein levels were studied in rats fed a normal diet, a HFD, and a HFD with intervention of RES for 8 weeks. Oxidative stress levels and antioxidant enzyme activities were assessed in SS and IMF mitochondria. HFD fed rats exhibited obvious systemic and skeletal muscle IR as well as decreased SIRT1 and SIRT3 expressions, mitochondrial DNA (mtDNA), and mitochondrial biogenesis (p < 0.05). Both SS and IMF mitochondria demonstrated elevated reactive oxygen species (ROS) and malondialdehyde (MDA) levels. In addition, SS mitochondrial antioxidant enzyme activities were significantly lower, while IMF mitochondrial antioxidant enzyme activities were higher (p < 0.05). By contrast, RES treatment protected rats against diet induced IR, increased SIRT1 and SIRT3 expressions, mtDNA, and mitochondrial biogenesis (p < 0.05). Moreover, the activities of SS and IMF mitochondrial antioxidant enzymes were increased, which reverted the increased SS mitochondrial oxidative stress levels (p < 0.05). This study suggests that RES ameliorates insulin sensitivity consistent with improved SIRT3 expressions and rebalance between SS mitochondrial oxidative stress and antioxidant competence in HFD rats.

  1. Concentration dependent effect of calcium on brain mitochondrial bioenergetics and oxidative stress parameters

    PubMed Central

    Pandya, Jignesh D.; Nukala, Vidya N.; Sullivan, Patrick G.

    2013-01-01

    Mitochondrial dysfunction following traumatic brain and spinal cord injury (TBI and SCI) plays a pivotal role in the development of secondary pathophysiology and subsequent neuronal cell death. Previously, we demonstrated a loss of mitochondrial bioenergetics in the first 24 h following TBI and SCI initiates a rapid and extensive necrotic event at the primary site of injury. Within the mitochondrial derived mechanisms, the cross talk and imbalance amongst the processes of excitotoxicity, Ca2+ cycling/overload, ATP synthesis, free radical production and oxidative damage ultimately lead to mitochondrial damage followed by neuronal cell death. Mitochondria are one of the important organelles that regulate intracellular calcium (Ca2+) homeostasis and are equipped with a tightly regulated Ca2+ transport system. However, owing to the lack of consensus and the link between downstream effects of calcium in published literature, we undertook a systematic in vitro study for measuring concentration dependent effects of calcium (100–1000 nmols/mg mitochondrial protein) on mitochondrial respiration, enzyme activities, reactive oxygen/nitrogen species (ROS/RNS) generation, membrane potential (ΔΨ) and oxidative damage markers in isolated brain mitochondria. We observed a dose- and time-dependent inhibition of mitochondrial respiration by calcium without influencing mitochondrial pyruvate dehydrogenase complex (PDHC) and NADH dehydrogenase (Complex I) enzyme activities. We observed dose-dependent decreased production of hydrogen peroxide and total ROS/RNS species generation by calcium and no significant changes in protein and lipid oxidative damage markers. These results may shed new light on the prevailing dogma of the direct effects of calcium on mitochondrial bioenergetics, free radical production and oxidative stress parameters that are primary regulatory mitochondrial mechanisms following neuronal injury. PMID:24385963

  2. Mitochondrial ferritin limits oxidative damage regulating mitochondrial iron availability: hypothesis for a protective role in Friedreich ataxia

    PubMed Central

    Campanella, Alessandro; Rovelli, Elisabetta; Santambrogio, Paolo; Cozzi, Anna; Taroni, Franco; Levi, Sonia

    2009-01-01

    Mitochondrial ferritin (FtMt) is a nuclear-encoded iron-sequestering protein that specifically localizes in mitochondria. In mice it is highly expressed in cells characterized by high-energy consumption, while is undetectable in iron storage tissues like liver and spleen. FtMt expression in mammalian cells was shown to cause a shift of iron from cytosol to mitochondria, and in yeast it rescued the defects associated with frataxin deficiency. To study the role of FtMt in oxidative damage, we analyzed the effect of its expression in HeLa cells after incubation with H2O2 and Antimycin A, and after a long-term growth in glucose-free media that enhances mitochondrial respiratory activity. FtMt reduced the level of reactive oxygen species (ROS), increased the level of adenosine 5'triphosphate and the activity of mitochondrial Fe-S enzymes, and had a positive effect on cell viability. Furthermore, FtMt expression reduces the size of cytosolic and mitochondrial labile iron pools. In cells grown in glucose-free media, FtMt level was reduced owing to faster degradation rate, however it still protected the activity of mitochondrial Fe-S enzymes without affecting the cytosolic iron status. In addition, FtMt expression in fibroblasts from Friedreich ataxia (FRDA) patients prevented the formation of ROS and partially rescued the impaired activity of mitochondrial Fe-S enzymes, caused by frataxin deficiency. These results indicate that the primary function of FtMt involves the control of ROS formation through the regulation of mitochondrial iron availability. They are consistent with the expression pattern of FtMt observed in mouse tissues, suggesting a FtMt protective role in cells characterized by defective iron homeostasis and respiration, such as in FRDA. PMID:18815198

  3. XPD localizes in mitochondria and protects the mitochondrial genome from oxidative DNA damage.

    PubMed

    Liu, Jing; Fang, Hongbo; Chi, Zhenfen; Wu, Zan; Wei, Di; Mo, Dongliang; Niu, Kaifeng; Balajee, Adayabalam S; Hei, Tom K; Nie, Linghu; Zhao, Yongliang

    2015-06-23

    Xeroderma pigmentosum group D (XPD/ERCC2) encodes an ATP-dependent helicase that plays essential roles in both transcription and nucleotide excision repair of nuclear DNA, however, whether or not XPD exerts similar functions in mitochondria remains elusive. In this study, we provide the first evidence that XPD is localized in the inner membrane of mitochondria, and cells under oxidative stress showed an enhanced recruitment of XPD into mitochondrial compartment. Furthermore, mitochondrial reactive oxygen species production and levels of oxidative stress-induced mitochondrial DNA (mtDNA) common deletion were significantly elevated, whereas capacity for oxidative damage repair of mtDNA was markedly reduced in both XPD-suppressed human osteosarcoma (U2OS) cells and XPD-deficient human fibroblasts. Immunoprecipitation-mass spectrometry analysis was used to identify interacting factor(s) with XPD and TUFM, a mitochondrial Tu translation elongation factor was detected to be physically interacted with XPD. Similar to the findings in XPD-deficient cells, mitochondrial common deletion and oxidative damage repair capacity in U2OS cells were found to be significantly altered after TUFM knock-down. Our findings clearly demonstrate that XPD plays crucial role(s) in protecting mitochondrial genome stability by facilitating an efficient repair of oxidative DNA damage in mitochondria.

  4. Increased Contextual Fear Conditioning in iNOS Knockout Mice: Additional Evidence for the Involvement of Nitric Oxide in Stress-Related Disorders and Contribution of the Endocannabinoid System.

    PubMed

    Lisboa, Sabrina F; Gomes, Felipe V; Silva, Andréia L; Uliana, Daniela L; Camargo, Laura H A; Guimarães, Francisco S; Cunha, Fernando Q; Joca, Sâmia R L; Resstel, Leonardo B M

    2015-01-24

    Inducible or neuronal nitric oxide synthase gene deletion increases or decreases anxiety-like behavior in mice, respectively. Since nitric oxide and endocannabinoids interact to modulate defensive behavior, the former effect could involve a compensatory increase in basal brain nitric oxide synthase activity and/or changes in the endocannabinoid system. Thus, we investigated the expression and extinction of contextual fear conditioning of inducible nitric oxide knockout mice and possible involvement of endocannabinoids in these responses. We evaluated the effects of a preferential neuronal nitric oxide synthase inhibitor, 7-nitroindazol, nitric oxide synthase activity, and mRNA changes of nitrergic and endocannabinoid systems components in the medial prefrontal cortex and hippocampus of wild-type and knockout mice. The effects of URB597, an inhibitor of the fatty acid amide hydrolase enzyme, which metabolizes the endocannabinoid anandamide, WIN55,212-2, a nonselective cannabinoid agonist, and AM281, a selective CB1 antagonist, on contextual fear conditioning were also evaluated. Contextual fear conditioning expression was similar in wild-type and knockout mice, but the latter presented extinction deficits and increased basal nitric oxide synthase activity in the medial prefrontal cortex. 7-Nitroindazol decreased fear expression and facilitated extinction in wild-type and knockout mice. URB597 decreased fear expression in wild-type and facilitated extinction in knockout mice, whereas WIN55,212-2 and AM281 increased it in wild-type mice. Nonconditioned knockout mice showed changes in the mRNA expression of nitrergic and endocannabinoid system components in the medial prefrontal cortex and hippocampus that were modified by fear conditioning. These data reinforce the involvement of the nitric oxide and endocannabinoids (anandamide) in stress-related disorders and point to a deregulation of the endocannabinoid system in situations where nitric oxide signaling is

  5. Increased Contextual Fear Conditioning in iNOS Knockout Mice: Additional Evidence for the Involvement of Nitric Oxide in Stress-Related Disorders and Contribution of the Endocannabinoid System

    PubMed Central

    Gomes, Felipe V.; Silva, Andréia L.; Uliana, Daniela L.; Camargo, Laura H. A.; Guimarães, Francisco S.; Cunha, Fernando Q.; Joca, Sâmia R. L.; Resstel, Leonardo B. M.

    2015-01-01

    Background: Inducible or neuronal nitric oxide synthase gene deletion increases or decreases anxiety-like behavior in mice, respectively. Since nitric oxide and endocannabinoids interact to modulate defensive behavior, the former effect could involve a compensatory increase in basal brain nitric oxide synthase activity and/or changes in the endocannabinoid system. Thus, we investigated the expression and extinction of contextual fear conditioning of inducible nitric oxide knockout mice and possible involvement of endocannabinoids in these responses. Methods: We evaluated the effects of a preferential neuronal nitric oxide synthase inhibitor, 7-nitroindazol, nitric oxide synthase activity, and mRNA changes of nitrergic and endocannabinoid systems components in the medial prefrontal cortex and hippocampus of wild-type and knockout mice. The effects of URB597, an inhibitor of the fatty acid amide hydrolase enzyme, which metabolizes the endocannabinoid anandamide, WIN55,212-2, a nonselective cannabinoid agonist, and AM281, a selective CB1 antagonist, on contextual fear conditioning were also evaluated. Results: Contextual fear conditioning expression was similar in wild-type and knockout mice, but the latter presented extinction deficits and increased basal nitric oxide synthase activity in the medial prefrontal cortex. 7-Nitroindazol decreased fear expression and facilitated extinction in wild-type and knockout mice. URB597 decreased fear expression in wild-type and facilitated extinction in knockout mice, whereas WIN55,212-2 and AM281 increased it in wild-type mice. Nonconditioned knockout mice showed changes in the mRNA expression of nitrergic and endocannabinoid system components in the medial prefrontal cortex and hippocampus that were modified by fear conditioning. Conclusion: These data reinforce the involvement of the nitric oxide and endocannabinoids (anandamide) in stress-related disorders and point to a deregulation of the endocannabinoid system in

  6. Perm1 enhances mitochondrial biogenesis, oxidative capacity, and fatigue resistance in adult skeletal muscle

    PubMed Central

    Cho, Yoshitake; Hazen, Bethany C.; Gandra, Paulo G.; Ward, Samuel R.; Schenk, Simon; Russell, Aaron P.; Kralli, Anastasia

    2016-01-01

    Skeletal muscle mitochondrial content and oxidative capacity are important determinants of muscle function and whole-body health. Mitochondrial content and function are enhanced by endurance exercise and impaired in states or diseases where muscle function is compromised, such as myopathies, muscular dystrophies, neuromuscular diseases, and age-related muscle atrophy. Hence, elucidating the mechanisms that control muscle mitochondrial content and oxidative function can provide new insights into states and diseases that affect muscle health. In past studies, we identified Perm1 (PPARGC1- and ESRR-induced regulator, muscle 1) as a gene induced by endurance exercise in skeletal muscle, and regulating mitochondrial oxidative function in cultured myotubes. The capacity of Perm1 to regulate muscle mitochondrial content and function in vivo is not yet known. In this study, we use adeno-associated viral (AAV) vectors to increase Perm1 expression in skeletal muscles of 4-wk-old mice. Compared to control vector, AAV1-Perm1 leads to significant increases in mitochondrial content and oxidative capacity (by 40–80%). Moreover, AAV1-Perm1–transduced muscles show increased capillary density and resistance to fatigue (by 33 and 31%, respectively), without prominent changes in fiber-type composition. These findings suggest that Perm1 selectively regulates mitochondrial biogenesis and oxidative function, and implicate Perm1 in muscle adaptations that also occur in response to endurance exercise.—Cho, Y., Hazen, B. C., Gandra, P. G., Ward, S. R., Schenk, S., Russell, A. P., Kralli, A. Perm1 enhances mitochondrial biogenesis, oxidative capacity, and fatigue resistance in adult skeletal muscle. PMID:26481306

  7. The Warburg effect in tumor progression: Mitochondrial oxidative metabolism as an anti-metastasis mechanism

    PubMed Central

    Lu, Jianrong; Tan, Ming; Cai, Qingsong

    2014-01-01

    Compared to normal cells, cancer cells strongly upregulate glucose uptake and glycolysis to give rise to increased yield of intermediate glycolytic metabolites and the end product pyruvate. Moreover, glycolysis is uncoupled from the mitochondrial tricarboxylic acid (TCA) cycle and oxidative phosphorylation (OXPHOS) in cancer cells. Consequently, the majority of glycolysis-derived pyruvate is diverted to lactate fermentation and kept away from mitochondrial oxidative metabolism. This metabolic phenotype is known as the Warburg effect. While it has become widely accepted that the glycolytic intermediates provide essential anabolic support for cell proliferation and tumor growth, it remains largely elusive whether and how the Warburg metabolic phenotype may play a role in tumor progression. We hereby review the cause and consequence of the restrained oxidative metabolism, in particular in tumor metastasis. Cells change or lose their extracellular matrix during the metastatic process. Inadequate/inappropriate matrix attachment generates reactive oxygen species (ROS) and causes a specific type of cell death, termed anoikis, in normal cells. Although anoikis is a barrier to metastasis, cancer cells have often acquired elevated threshold for anoikis and hence heightened metastatic potential. As ROS are inherent byproducts of oxidative metabolism, forced stimulation of glucose oxidation in cancer cells raises oxidative stress and restores cells’ sensitivity to anoikis. Therefore, by limiting the pyruvate flux into mitochondrial oxidative metabolism, the Warburg effect enables cancer cells to avoid excess ROS generation from mitochondrial respiration and thus gain increased anoikis resistance and survival advantage for metastasis. Consistent with this notion, pro-metastatic transcription factors HIF and Snail attenuate oxidative metabolism, whereas tumor suppressor p53 and metastasis suppressor KISS1 promote mitochondrial oxidation. Collectively, these findings reveal

  8. The Warburg effect in tumor progression: mitochondrial oxidative metabolism as an anti-metastasis mechanism.

    PubMed

    Lu, Jianrong; Tan, Ming; Cai, Qingsong

    2015-01-28

    Compared to normal cells, cancer cells strongly upregulate glucose uptake and glycolysis to give rise to increased yield of intermediate glycolytic metabolites and the end product pyruvate. Moreover, glycolysis is uncoupled from the mitochondrial tricarboxylic acid (TCA) cycle and oxidative phosphorylation (OXPHOS) in cancer cells. Consequently, the majority of glycolysis-derived pyruvate is diverted to lactate fermentation and kept away from mitochondrial oxidative metabolism. This metabolic phenotype is known as the Warburg effect. While it has become widely accepted that the glycolytic intermediates provide essential anabolic support for cell proliferation and tumor growth, it remains largely elusive whether and how the Warburg metabolic phenotype may play a role in tumor progression. We hereby review the cause and consequence of the restrained oxidative metabolism, in particular in the context of tumor metastasis. Cells change or lose their extracellular matrix during the metastatic process. Inadequate/inappropriate matrix attachment generates reactive oxygen species (ROS) and causes a specific type of cell death, termed anoikis, in normal cells. Although anoikis is a barrier to metastasis, cancer cells have often acquired elevated threshold for anoikis and hence heightened metastatic potential. As ROS are inherent byproducts of oxidative metabolism, forced stimulation of glucose oxidation in cancer cells raises oxidative stress and restores cells' sensitivity to anoikis. Therefore, by limiting the pyruvate flux into mitochondrial oxidative metabolism, the Warburg effect enables cancer cells to avoid excess ROS generation from mitochondrial respiration and thus gain increased anoikis resistance and survival advantage for metastasis. Consistent with this notion, pro-metastatic transcription factors HIF and Snail attenuate oxidative metabolism, whereas tumor suppressor p53 and metastasis suppressor KISS1 promote mitochondrial oxidation. Collectively, these

  9. Oxidative stress, mitochondrial perturbations and fetal programming of renal disease induced by maternal smoking.

    PubMed

    Stangenberg, Stefanie; Nguyen, Long T; Chen, Hui; Al-Odat, Ibrahim; Killingsworth, Murray C; Gosnell, Martin E; Anwer, Ayad G; Goldys, Ewa M; Pollock, Carol A; Saad, Sonia

    2015-07-01

    An adverse in-utero environment is increasingly recognized to predispose to chronic disease in adulthood. Maternal smoking remains the most common modifiable adverse in-utero exposure leading to low birth weight, which is strongly associated with chronic kidney disease (CKD) in later life. In order to investigate underlying mechanisms for such susceptibility, female Balb/c mice were sham or cigarette smoke-exposed (SE) for 6 weeks before mating, throughout gestation and lactation. Offspring kidneys were examined for oxidative stress, expression of mitochondrial proteins, mitochondrial structure as well as renal functional parameters on postnatal day 1, day 20 (weaning) and week 13 (adult age). From birth throughout adulthood, SE offspring had increased renal levels of mitochondrial-derived reactive oxygen species (ROS), which left a footprint on DNA with increased 8-hydroxydeoxyguanosin (8-OHdG) in kidney tubular cells. Mitochondrial structural abnormalities were seen in SE kidneys at day 1 and week 13 along with a reduction in oxidative phosphorylation (OXPHOS) proteins and activity of mitochondrial antioxidant Manganese superoxide dismutase (MnSOD). Smoke exposure also resulted in increased mitochondrial DNA copy number (day 1-week 13) and lysosome density (day 1 and week 13). The appearance of mitochondrial defects preceded the onset of albuminuria at week 13. Thus, mitochondrial damage caused by maternal smoking may play an important role in development of CKD at adult life.

  10. Oxidants and not alkylating agents induce rapid mtDNA loss and mitochondrial dysfunction

    PubMed Central

    Furda, Amy M.; Marrangoni, Adele M.; Lokshin, Anna; Van Houten, Bennett

    2013-01-01

    Mitochondrial DNA (mtDNA) is essential for proper mitochondrial function and encodes 22 tRNAs, 2 rRNAs and 13 polypeptides that make up subunits of complex I, III, IV, in the electron transport chain and complex V, the ATP synthase. Although mitochondrial dysfunction has been implicated in processes such as premature aging, neurodegeneration, and cancer, it has not been shown whether persistent mtDNA damage causes a loss of oxidative phosphorylation. We addressed this question by treating mouse embryonic fibroblasts with either hydrogen peroxide (H2O2) or the alkylating agent methyl methanesulfonate (MMS) and measuring several endpoints, including mtDNA damage and repair rates using QPCR, levels of mitochondrial- and nuclear-encoded proteins using antibody analysis, and a pharmacologic profile of mitochondria using the Seahorse Extracellular Flux Analyzer. We show that a 60 min treatment with H2O2 causes persistent mtDNA lesions, mtDNA loss, decreased levels of a nuclear-encoded mitochondrial subunit, a loss of ATP-linked oxidative phosphorylation and a loss of total reserve capacity. Conversely, a 60 min treatment with 2 mM MMS causes persistent mtDNA lesions but no mtDNA loss, no decrease in levels of a nuclear-encoded mitochondrial subunit, and no mitochondrial dysfunction. These results suggest that persistent mtDNA damage is not sufficient to cause mitochondrial dysfunction. PMID:22766155

  11. Cardiac Mitochondrial Proteome Dynamics with Heavy Water Reveals Stable Rate of Mitochondrial Protein Synthesis in Heart Failure Despite Decline in Mitochondrial Oxidative Capacity

    PubMed Central

    Shekar, Kadambari Chandra; Li, Ling; Dabkowski, Erinne R.; Xu, Wenhong; Ribeiro, Rogerio Faustino; Hecker, Peter A.; Recchia, Fabio A.; Sadygov, Rovshan G.; Willard, Belinda; Kasumov, Takhar; Stanley, William C.

    2017-01-01

    We recently developed a method to measure mitochondrial proteome dynamics with heavy water (2H2O)-based metabolic labeling and high resolution mass spectrometry. We reported the half-lives and synthesis rates of several proteins in the two cardiac mitochondrial subpopulations, subsarcolemmal and interfibrillar (SSM and IFM), in Sprague Dawley rats. In the present study, we tested the hypothesis that the mitochondrial protein synthesis rate is reduced in heart failure, with possible differential changes in SSM versus IFM. Six to seven week old male Sprague Dawley rats underwent transverse aortic constriction (TAC) and developed moderate heart failure after 22 weeks. Heart failure and sham rats of the same age received heavy water (5% in drinking water) for up to 80 days. Cardiac SSM and IFM were isolated from both groups and the proteins were separated by 1D gel electrophoresis. Heart failure reduced protein content and increased the turnover rate of several proteins involved in fatty acid oxidation, electron transport chain and ATP synthesis, while it decreased the turnover of other proteins, including pyruvate dehydrogenase subunit in IFM, but not in SSM. Because of these bidirectional changes, the average overall half-life of proteins was not altered by heart failure in both SSM and IFM. The kinetic measurements of individual mitochondrial proteins presented in this study may contribute to a better understanding of the mechanisms responsible for mitochondrial alterations in the failing heart. PMID:24995939

  12. Increasing mitochondrial muscle fatty acid oxidation induces skeletal muscle remodeling toward an oxidative phenotype.

    PubMed

    Hénique, Carole; Mansouri, Abdelhak; Vavrova, Eliska; Lenoir, Véronique; Ferry, Arnaud; Esnous, Catherine; Ramond, Elodie; Girard, Jean; Bouillaud, Frédéric; Prip-Buus, Carina; Cohen, Isabelle

    2015-06-01

    Adult skeletal muscle is a dynamic, remarkably plastic tissue, which allows myofibers to switch from fast/glycolytic to slow/oxidative types and to increase mitochondrial fatty acid oxidation (mFAO) capacity and vascularization in response to exercise training. mFAO is the main muscle energy source during endurance exercise, with carnitine palmitoyltransferase 1 (CPT1) being the key regulatory enzyme. Whether increasing muscle mFAO affects skeletal muscle physiology in adulthood actually remains unknown. To investigate this, we used in vivo electrotransfer technology to express in mouse tibialis anterior (TA), a fast/glycolytic muscle, a mutated CPT1 form (CPT1mt) that is active but insensitive to malonyl-CoA, its physiologic inhibitor. In young (2-mo-old) adult mice, muscle CPT1mt expression enhanced mFAO (+40%), but also increased the percentage of oxidative fibers (+28%), glycogen content, and capillary-to-fiber density (+45%). This CPT1mt-induced muscle remodeling, which mimicked exercise-induced oxidative phenotype, led to a greater resistance to muscle fatigue. In the context of aging, characterized by sarcopenia and reduced oxidative capacity, CPT1mt expression in TAs from aged (20-mo-old) mice partially reversed aging-associated sarcopenia and fiber-type transition, and increased muscle capillarity. These findings provide evidence that mFAO regulates muscle phenotype and may be a potential target to combat age-related decline in muscle function.

  13. Melatonin improves age-induced fertility decline and attenuates ovarian mitochondrial oxidative stress in mice

    PubMed Central

    Song, Chao; Peng, Wei; Yin, Songna; Zhao, Jiamin; Fu, Beibei; Zhang, Jingcheng; Mao, Tingchao; Wu, Haibo; Zhang, Yong

    2016-01-01

    Increasing evidence shows that melatonin protected against age-related mitochondrial oxidative damage. However, the protective effects of melatonin against ovarian aging has not been explored. Young Kunming females (aged 2–3 months) were fed with melatonin added to drinking water for 6 or 12 months (mo). We found that long-term (12 mo) melatonin treatment significantly reduced ovarian aging, as indicated by substantial increases in litter size, pool of follicles, and telomere length as well as oocyte quantity and quality. Melatonin treatment suppressed ovarian mitochondrial oxidative damage by decreasing mitochondrial reactive oxygen species (mROS) generation, inhibiting apoptosis, repressing collapse of mitochondrial membrane potential and preserving respiratory chain complex activities. Female mice fed with melatonin had enhanced mitochondrial antioxidant activities, thus reducing the risk of mitochondrial oxidative damage cause by free radicals. Notably, melatonin treatment enhanced SIRT3 activity but not the protein expression level, and increased the binding affinity of FoxO3a to the promoters of both superoxide dismutase 2 (SOD2) and catalase (CAT). In conclusion, melatonin exerted protection against aging-induced fertility decline and maintenance of mitochondrial redox balance. PMID:27731402

  14. Alcohol-induced oxidative/nitrosative stress alters brain mitochondrial membrane properties.

    PubMed

    Reddy, Vaddi Damodara; Padmavathi, Pannuru; Kavitha, Godugu; Saradamma, Bulle; Varadacharyulu, Nallanchakravarthula

    2013-03-01

    Chronic alcohol consumption causes numerous biochemical and biophysical changes in the central nervous system, in which mitochondria is the primary organelle affected. In the present study, we hypothesized that alcohol alters the mitochondrial membrane properties and leads to mitochondrial dysfunction via mitochondrial reactive oxygen species (mROS) and reactive nitrogen species (RNS). Alcohol-induced hypoxia further enhances these effects. Administration of alcohol to rats significantly increased the mitochondrial lipid peroxidation and protein oxidation with decreased SOD2 mRNA and protein expression was decreased, while nitric oxide (NO) levels and expression of iNOS and nNOS in brain cortex were increased. In addition, alcohol augmented HIF-1α mRNA and protein expression in the brain cortex. Results from this study showed that alcohol administration to rats decreased mitochondrial complex I, III, IV activities, Na(+)/K(+)-ATPase activity and cardiolipin content with increased anisotropic value. Cardiolipin regulates numerous enzyme activities, especially those related to oxidative phosphorylation and coupled respiration. In the present study, decreased cardiolipin could be ascribed to ROS/RNS-induced damage. In conclusion, alcohol-induced ROS/RNS is responsible for the altered mitochondrial membrane properties, and alcohol-induced hypoxia further enhance these alterations, which ultimately leads to mitochondrial dysfunction.

  15. Mitochondrial targeting of bilirubin regulatory enzymes: An adaptive response to oxidative stress

    SciTech Connect

    Muhsain, Siti Nur Fadzilah; Lang, Matti A.; Abu-Bakar, A'edah

    2015-01-01

    The intracellular level of bilirubin (BR), an endogenous antioxidant that is cytotoxic at high concentrations, is tightly controlled within the optimal therapeutic range. We have recently described a concerted intracellular BR regulation by two microsomal enzymes: heme oxygenase 1 (HMOX1), essential for BR production and cytochrome P450 2A5 (CYP2A5), a BR oxidase. Herein, we describe targeting of these enzymes to hepatic mitochondria during oxidative stress. The kinetics of microsomal and mitochondrial BR oxidation were compared. Treatment of DBA/2J mice with 200 mg pyrazole/kg/day for 3 days increased hepatic intracellular protein carbonyl content and induced nucleo-translocation of Nrf2. HMOX1 and CYP2A5 proteins and activities were elevated in microsomes and mitoplasts but not the UGT1A1, a catalyst of BR glucuronidation. A CYP2A5 antibody inhibited 75% of microsomal BR oxidation. The inhibition was absent in control mitoplasts but elevated to 50% after treatment. An adrenodoxin reductase antibody did not inhibit microsomal BR oxidation but inhibited 50% of mitochondrial BR oxidation. Ascorbic acid inhibited 5% and 22% of the reaction in control and treated microsomes, respectively. In control mitoplasts the inhibition was 100%, which was reduced to 50% after treatment. Bilirubin affinity to mitochondrial and microsomal CYP2A5 enzyme is equally high. Lastly, the treatment neither released cytochrome c into cytoplasm nor dissipated membrane potential, indicating the absence of mitochondrial membrane damage. Collectively, the observations suggest that BR regulatory enzymes are recruited to mitochondria during oxidative stress and BR oxidation by mitochondrial CYP2A5 is supported by mitochondrial mono-oxygenase system. The induced recruitment potentially confers membrane protection. - Highlights: • Pyrazole induces oxidative stress in the mouse liver. • Pyrazole-induced oxidative stress induces mitochondrial targeting of key bilirubin regulatory enzymes, HMOX1

  16. [Cyclosporin A causes oxidative stress and mitochondrial dysfunction in renal tubular cells].

    PubMed

    Pérez de Hornedo, J; de Arriba, G; Calvino, M; Benito, S; Parra, T

    2007-01-01

    Reactive oxygen species (ROS) have been implicated in cyclosporin A (CsA) nephrotoxicity. As mitochondria are one of the main sources of ROS in cells, we evaluated the role of CsA in mitochondrial structure and function in LLC-PK1 cells. We incubated cells with CsA 1 microM for 24 hours and studies were performed with flow citometry and confocal microscopy. We studied mitochondrial NAD(P)H content, superoxide anion (O2.-) production (MitoSOX Red), oxidation of cardiolipin of inner mitochondrial membrane (NAO) and mitochondrial membrane potential (DIOC2(3)). Also we analyzed the intracellular ROS synthesis (H2DCF-DA) and reduced glutation (GSH) of cells. Our results showed that CsA decreased NAD(P)H and membrane potential, and increased O2.- in mitochondria. CsA also provoked oxidation of cardiolipin. Furthermore, CsA increased intracellular ROS production and decreased GSH content. These results suggest that CsA has crucial effects in mitochondria. CsA modified mitochondrial physiology through the decrease of antioxidant mitochondrial compounds as NAD(P)H and the dissipation of mitochondrial membrane potential and increase of oxidants as O2.-. Also, CsA alters lipidic structure of inner mitochondrial membrane through the oxidation of cardiolipin. These effects trigger a chain of events that favour intracellular synthesis of ROS and depletion of GSH that can compromise cellular viability. Nephrotoxic cellular effects of CsA can be explained, at least in part, through its influence on mitochondrial functionalism.

  17. Mitochondrial and peroxisomal beta-oxidation capacities of organs from a non-oilseed plant.

    PubMed

    Masterson, C; Wood, C

    2001-09-22

    Until recently, beta-oxidation was believed to be exclusively located in the peroxisomes of all higher plants. Whilst this is true for germinating oilseeds undergoing gluconeogenesis, evidence demonstrating mitochondrial beta-oxidation in other plant systems has refuted this central dogma of plant lipid metabolism. This report describes a comparative study of the dual mitochondrial and peroxisomal beta-oxidation capacities of plant organs. Oxidation of [1-(14)C] palmitate was measured in the cotyledons, plumules and radicles of Pisum sativum L., which is a starchy seed, over a 14 day period from the commencement of imbibition. Respiratory chain inhibitors were used for differentiating between mitochondrial and peroxisomal beta-oxidation. Peroxisomal beta-oxidation gave a steady, baseline rate and, in the early stages of seedling development, accounted for 70-100% of the beta-oxidation observed. Mitochondrial beta-oxidation gave peaks of activity at days 7 and 10-11, accounting for up to 82% of the total beta-oxidation activity at these times. These peaks coincide with key stages of seedling development and were not observed when normal development was disrupted by growth in the dark. Peroxisomal beta-oxidation was unaffected by etiolation. Since mitochondrial beta-oxidation was overt only during times of intense biosynthetic activity it might be switched on or off during seedling development. In contrast, peroxisomes maintained a continuous, low beta-oxidation activity that could be essential in removing harmful free fatty acids, e.g. those produced by protein and lipid turnover.

  18. Mitochondrial oxidative stress during cardiac lipid overload causes intracellular calcium leak and arrhythmia

    PubMed Central

    Joseph, Leroy C.; Subramanyam, Prakash; Radlicz, Christopher; Trent, Chad M.; Iyer, Vivek; Colecraft, Henry M.; Morrow, John P.

    2016-01-01

    Background Diabetes and obesity are associated with an increased risk of arrhythmia and sudden cardiac death. Abnormal lipid accumulation is observed in cardiomyocytes of obese and diabetic patients, which may contribute to arrhythmia, but the mechanisms are poorly understood. A transgenic mouse model of cardiac lipid overload, the PPARg cardiac overexpression mouse, has long QT and increased ventricular ectopy. Objective We evaluated the hypothesis that the increase in ventricular ectopy during cardiac lipid overload is caused by abnormalities in calcium handling due to increased mitochondrial oxidative stress. Methods Ventricular myocytes were isolated from adult mouse hearts to record sparks and calcium transients. Mice were implanted with heart rhythm monitors for in vivo recordings. Results PPARg cardiomyocytes have more frequent triggered activity and increased sparks compared to control. Sparks and triggered activity are reduced by mitotempo, a mitochondrial-targeted antioxidant. This is explained by a significant increase in oxidation of RyR2. Calcium transients are increased in amplitude and SR calcium stores are increased in PPARg cardiomyocytes. Computer modeling of the cardiac action potential demonstrates that long QT contributes to increased SR calcium. Mitotempo decreased ventricular ectopy in vivo. Conclusions During cardiac lipid overload, mitochondrial oxidative stress causes increased SR calcium leak by oxidizing RyR2 channels. This promotes ventricular ectopy, which is significantly reduced in vivo by a mitochondrial-targeted anti-oxidant. These results suggest a potential role for mitochondrial-targeted anti-oxidants to prevent arrhythmia and sudden cardiac death in obese and diabetic patients. PMID:27154230

  19. Mitochondrial Dysfunction during Brain Aging: Role of Oxidative Stress and Modulation by Antioxidant Supplementation

    PubMed Central

    Chakrabarti, Sasanka; Munshi, Soumyabrata; Banerjee, Kalpita; Thakurta, Ishita Guha; Sinha, Maitrayee; Bagh, Maria Bindu

    2011-01-01

    Mitochondrial dysfunction and oxidative stress are two interdependent and reinforcing damage mechanisms that play a central role in brain aging. Oxidative stress initiated and propagated by active oxyradicals and various other free radicals in the presence of catalytic metal ions not only can damage the phospholipid, protein and DNA molecules within the cell but can also modulate cell signalling pathways and gene expression pattern and all these processes may be of critical importance in the aging of brain. The present article describes the mechanism of formation of reactive oxyradicals within mitochondria and then explains how these can initiate mitochondrial biogenesis program and activate various transcriptional factors in the cytosol to boost up the antioxidative capacity of the mitochondria and the cell. However, a high level of oxidative stress finally inflicts critical damage to the oxidative phosphorylation machinery and mitochondrial DNA (mtDNA). The latter part of the article is a catalogue showing the accumulating evidence in favour of oxidative inactivation of mitochondrial functions in aged brain and the detailed reports of various studies with antioxidant supplementation claiming variable success in preventing the age-related brain mitochondrial decay and cognitive decline. The antioxidant supplementation approach may be of potential help in the management of neurodegenerative diseases like Alzheimer’s disease. The newly developed mitochondria-targeted antioxidants have brought a new direction to experimental studies related to oxidative damage and they may provide potential drugs in near future for a variety of diseases or degenerative conditions including brain aging and neurodegenerative disorders. PMID:22396876

  20. Indirubin-3'-oxime impairs mitochondrial oxidative phosphorylation and prevents mitochondrial permeability transition induction

    SciTech Connect

    Varela, Ana T.; Gomes, Ana P.; Simoes, Anabela M.; Teodoro, Joao S.; Duarte, Filipe V.; Rolo, Anabela P.; Palmeira, Carlos M.

    2008-12-01

    Indirubin, a red colored 3,2'-bisindole isomer, is a component of Indigo naturalis and is an active ingredient used in traditional Chinese medicine for the treatment of chronic diseases. The family of indirubin derivatives, such as indirubin-3'-oxime, has been suggested for various therapeutic indications. However, potential toxic interactions such as indirubin effects on mitochondrial bioenergetics are still unknown. This study evaluated the action of indirubin-3'-oxime on the function of isolated rat liver mitochondria contributing to a better understanding of the biochemical mechanisms underlying the multiple effects of indirubin. Indirubin-3'-oxime incubated with isolated rat liver mitochondria, at concentrations above 10{mu}M, significantly depresses the phosphorylation efficiency of mitochondria as inferred from the decrease in the respiratory control and ADP/O ratios, the perturbations in mitochondrial membrane potential and in the phosphorylative cycle induced by ADP. Furthermore, indirubin-3'-oxime at up to 25{mu}M stimulates the rate of state 4 respiration and inhibits state 3 respiration. The increased lag phase of repolarization was associated with a direct inhibition of the mitochondrial ATPase. Indirubin-3'-oxime significantly inhibited the activity of complex II and IV thus explaining the decreased FCCP-stimulated mitochondrial respiration. Mitochondria pre-incubated with indirubin-3'-oxime exhibits decreased susceptibility to calcium-induced mitochondrial permeability transition. This work shows for the first time multiple effects of indirubin-3'-oxime on mitochondrial bioenergetics thus indicating a potential mechanism for indirubin-3'-oxime effects on cell function.

  1. Assessing of oxidative stress related parameters in diabetes mellitus type 2: cause excessive damaging to DNA and enhanced homocysteine in diabetic patients.

    PubMed

    Bukhari, Shazia Anwer; Naqvi, Syed Ali Raza; Nagra, Saeed Ahmad; Anjum, Fauzia; Javed, Sadia; Farooq, Muhammad

    2015-03-01

    Oxidative stress and reactive oxygen species (ROS) have been documented subsist to the pathogenesis of many diseases including diabetes mellitus. The strength of both parameters could be estimated by measuring oxidative stress marker thiobarbituric acid reactive substances (TBARS), its related parameters and the antioxidants glutathione peroxidase and superoxide dismutase (SOD) in plasma of DM patients. Lipid peroxidation was measured as TBARS and presented as malondialdehyde, total cholesterol (TC), low-density lipoprotein (LDL), triglyceride (Tg), the antioxidants (vitamin A (β-carotene), vitamin E, vitamin C, glutathione peroxidase (GPx) and superoxide dismutase) levels. The results showed that these parameters, commonly, were declined appreciably in diabetic individuals as compared to the healthy individuals. In most cases, age and gender were appeared to involve in having greater values of diabetes marker. Further, increased level of lipid peroxidation and random behaviour of antioxidant potential also associated with Diabetes. For that reason these biomarkers might be of great important to diagnosis DNA damages of diabetic patients.

  2. Effect of endogenous nitric oxide on mitochondrial respiration of rat hepatocytes in vitro and in vivo

    SciTech Connect

    Stadler, J.; Curran, R.D.; Ochoa, J.B.; Harbrecht, B.G.; Hoffman, R.A.; Simmons, R.L.; Billiar, T.R. )

    1991-02-01

    Nitric oxide, a highly reactive radical, was recently identified as an intermediate of L-arginine metabolism in mammalian cells. We have shown that nitric oxide synthesis is induced in vitro in cultured hepatocytes by supernatants from activated Kupffer cells or in vivo by injecting rats with nonviable Corynebacterium parvum. In both cases, nitric oxide biosynthesis in hepatocytes was associated with suppression of total protein synthesis. This study attempts to determine the effect of nitric oxide biosynthesis on the activity of specific hepatocytic mitochondrial enzymes and to determine whether inhibition of protein synthesis is caused by suppression of energy metabolism. Exposure of hepatocytes to supernatants from activated Kupffer cells led to a 30% decrease of aconitase (Krebs cycle) and complex I (mitochondrial electron transport chain) activity. Using NG-monomethyl-L-arginine, an inhibitor of nitric oxide synthesis, we demonstrated that the inhibition of mitochondrial aconitase activity was due, in part, to the action of nitric oxide. In contrast, in vivo nitric oxide synthesis of hepatocytes from Corynebacterium parvum-treated animals had no effect on mitochondrial respiration. This suggests that inhibition of protein synthesis by nitric oxide is not likely to be mediated by inhibition of energy metabolism.

  3. Cellular and molecular oxidative stress-related effects in uterine myometrial and trophoblast-decidual tissues after perigestational alcohol intake up to early mouse organogenesis.

    PubMed

    Coll, Tamara Anahí; Chaufan, Gabriela; Pérez-Tito, Leticia Gabriela; Ventureira, Martín Ricardo; Ríos de Molina, María Del Carmen; Cebral, Elisa

    2017-08-18

    The placenta plays a major role in embryo-fetal defects and intrauterine growth retardation after maternal alcohol consumption. Our aims were to determine the oxidative status and cellular and molecular oxidative stress effects on uterine myometrium and trophoblast-decidual tissue following perigestational alcohol intake at early organogenesis. CF-1 female mice were administered with 10% alcohol in drinking water for 17 days prior to and up to day 10 of gestation. Control females received ethanol-free water. Treated mice had smaller implantation sites compared to controls (p < 0.05), diminished maternal vascular lumen, and irregular/discontinuous endothelium of decidual vessels. The trophoblast giant cell layer was disorganized and presented increased abnormal nuclear frequency. The myometrium of treated females had reduced nitrite content, increased superoxide dismutase activity, and reduced glutathione (GSH) content (p < 0.05). However, the trophoblast-decidual tissue of treated females had increased nitrite content (p < 0.05), increased GSH level (p < 0.001), increased thiobarbituric acid-reactive substance concentration (p < 0.001), higher 3-nitrotyrosine immunoreaction, and increased apoptotic index (p < 0.05) compared to controls. In summary, perigestational alcohol ingestion at organogenesis induced oxidative stress in the myometrium and trophoblast-decidual tissue, mainly affecting cells and macromolecules of trophoblast and decidual tissues around early organogenesis, in CF-1 mouse, and suggests that oxidative-induced abnormal early placental formation probably leads to risk of prematurity and fetal growth impairment at term.

  4. Melatonin and hydroxytyrosol protect against oxidative stress related to the central nervous system after the ingestion of three types of wine by healthy volunteers.

    PubMed

    Marhuenda, Javier; Medina, Sonia; Martínez-Hernández, Pedro; Arina, Simón; Zafrilla, Pilar; Mulero, Juana; Oger, Camille; Galano, Jean-Marie; Durand, Thierry; Ferreres, Federico; Gil-Izquierdo, Angel

    2017-01-25

    Adrenic acid (AdA) and docosahexaenoic acid (DHA) peroxidation produces F2-dihomo-IsoPs and neuroprostanes, which have been related to oxidative damage in the central nervous system. Besides polyphenols, melatonin (MEL) and hydroxytyrosol (OHTyr) could be partly responsible for the antioxidant benefits of red wine (excluding colon derivatives). In order to elucidate whether these compounds are responsible for the protective antioxidant effects of red wine, a double-blind, crossover, placebo-controlled in vivo study - involving the intake of red wines and their native musts by healthy volunteers - was performed. The urinary metabolites decreased after the administration of red wines, to a greater extent than after the intake of their corresponding musts or ethanol. Melatonin is the most effective compound that protects adrenic acid from oxidative attack, judged by the reduction in the formation of F2-dihomo-isoprostanes. Similarly, hydroxytyrosol, being the most effective bioactive compound in reducing the formation of F3-neuroprostanes n-6 DPA and F4-neuroprostanes, protected docosahexaenoic and eicosapentaenoic acids from oxidative attack.

  5. Curcumin prevents mitochondrial dynamics disturbances in early 5/6 nephrectomy: Relation to oxidative stress and mitochondrial bioenergetics.

    PubMed

    Aparicio-Trejo, Omar Emiliano; Tapia, Edilia; Molina-Jijón, Eduardo; Medina-Campos, Omar Noel; Macías-Ruvalcaba, Norma Angélica; León-Contreras, Juan Carlos; Hernández-Pando, Rogelio; García-Arroyo, Fernando E; Cristóbal, Magdalena; Sánchez-Lozada, Laura Gabriela; Pedraza-Chaverri, José

    2016-11-01

    Five-sixths nephrectomy (5/6NX) is a widely used model to study the mechanisms leading to renal damage in chronic kidney disease (CKD). However, early alterations on renal function, mitochondrial dynamics, and oxidative stress have not been explored yet. Curcumin is an antioxidant that has shown nephroprotection in 5/6NX-induced renal damage. The aim of this study was to explore the effect of curcumin on early mitochondrial alterations induced by 5/6NX in rats. In isolated mitochondria, 5/6NX-induced hydrogen peroxide production was associated with decreased activity of complexes I and V, decreased activity of antioxidant enzymes, alterations in oxygen consumption and increased MDA-protein adducts. In addition, it was found that 5/6NX shifted mitochondrial dynamics to fusion, which was evidenced by increased optic atrophy 1 and mitofusin 1 (Mfn1) and decreased fission 1 and dynamin-related protein 1 expressions. These data were confirmed by morphological analysis and immunoelectron microscopy of Mfn-1. All the above-described mechanisms were prevented by curcumin. Also, it was found that curcumin prevented renal dysfunction by improving renal blood flow and the total antioxidant capacity induced by 5/6NX. Moreover, in glomeruli and proximal tubules 5/6NX-induced superoxide anion production by uncoupled nitric oxide synthase (NOS) and nicotinamide adenine dinucleotide phosphate oxidase (NOX) dependent way, this latter was associated with increased phosphorylation of serine 304 of p47phox subunit of NOX. In conclusion, this study shows that curcumin pretreatment decreases early 5/6NX-induced altered mitochondrial dynamics, bioenergetics, and oxidative stress, which may be associated with the preservation of renal function. © 2016 BioFactors, 00(00):000000, 2016.

  6. Mitochondrial ROS regulate oxidative damage and mitophagy but not age-related muscle fiber atrophy

    PubMed Central

    Sakellariou, Giorgos K.; Pearson, Timothy; Lightfoot, Adam P.; Nye, Gareth A.; Wells, Nicola; Giakoumaki, Ifigeneia I.; Vasilaki, Aphrodite; Griffiths, Richard D.; Jackson, Malcolm J.; McArdle, Anne

    2016-01-01

    Age-related loss of skeletal muscle mass and function is a major contributor to morbidity and has a profound effect on the quality of life of older people. The potential role of age-dependent mitochondrial dysfunction and cumulative oxidative stress as the underlying cause of muscle aging remains a controversial topic. Here we show that the pharmacological attenuation of age-related mitochondrial redox changes in muscle with SS31 is associated with some improvements in oxidative damage and mitophagy in muscles of old mice. However, this treatment failed to rescue the age-related muscle fiber atrophy associated with muscle atrophy and weakness. Collectively, these data imply that the muscle mitochondrial redox environment is not a key regulator of muscle fiber atrophy during sarcopenia but may play a key role in the decline of mitochondrial organelle integrity that occurs with muscle aging. PMID:27681159

  7. Therapeutic Strategies for Mitochondrial Dysfunction and Oxidative Stress in Age-Related Metabolic Disorders.

    PubMed

    Bhatti, J S; Kumar, S; Vijayan, M; Bhatti, G K; Reddy, P H

    2017-01-01

    Mitochondria are complex, intercellular organelles present in the cells and are involved in multiple roles including ATP formation, free radicals generation and scavenging, calcium homeostasis, cellular differentiation, and cell death. Many studies depicted the involvement of mitochondrial dysfunction and oxidative damage in aging and pathogenesis of age-related metabolic disorders and neurodegenerative diseases. Remarkable advancements have been made in understanding the structure, function, and physiology of mitochondria in metabolic disorders such as diabetes, obesity, cardiovascular diseases, and stroke. Further, much progress has been done in the improvement of therapeutic strategies, including lifestyle interventions, pharmacological, and mitochondria-targeted therapeutic approaches. These strategies were mainly focused to reduce the mitochondrial dysfunction caused by oxidative stress and to retain the mitochondrial health in various diseases. In this chapter, we have highlighted the involvement of mitochondrial dysfunction in the pathophysiology of various disorders and recent progress in the development of mitochondria-targeted molecules as therapeutic measures for metabolic disorders.

  8. Protective effect of N-acetylcysteine supplementation on mitochondrial oxidative stress and mitochondrial enzymes in cerebral cortex of streptozotocin-treated diabetic rats.

    PubMed

    Kamboj, Sukhdev S; Sandhir, Rajat

    2011-01-01

    Diabetic encephalopathy, characterized by cognitive deficits involves hyperglycemia-induced oxidative stress. Impaired mitochondrial functions might play an important role in accelerated oxidative damage observed in diabetic brain. The aim of the present study was to examine the role of mitochondrial oxidative stress and dysfunctions in the development of diabetic encephalopathy along with the neuroprotective potential of N-acetylcysteine (NAC). Chronic hyperglycemia accentuated mitochondrial oxidative stress in terms of increased ROS production and lipid peroxidation. Significant decrease in Mn-SOD activity along with protein and non-protein thiols was observed in the mitochondria from diabetic brain. The activities of mitochondrial enzymes; NADH dehydrogenase, succinate dehydrogenase and cytochrome oxidase were decreased in the diabetic brain. Increased mitochondrial oxidative stress and dysfunctions were associated with increased cytochrome c and active caspase-3 levels in cytosol. Electron microscopy revealed mitochondrial swelling and chromatin condensation in neurons of diabetic animals. NAC administration, on the other hand was found to significantly improve diabetes-induced biochemical and morphological changes, bringing them closer to the controls. The results from the study provide evidence for the role of mitochondrial oxidative stress and dysfunctions in the development of diabetic encephalopathy and point towards the clinical potential of NAC as an adjuvant therapy to conventional anti-hyperglycemic regimens for the prevention and/or delaying the progression of CNS complications. Copyright © 2010 Elsevier B.V. and Mitochondria Research Society. All rights reserved.

  9. Methionine restriction decreases mitochondrial oxygen radical generation and leak as well as oxidative damage to mitochondrial DNA and proteins.

    PubMed

    Sanz, Alberto; Caro, Pilar; Ayala, Victoria; Portero-Otin, Manuel; Pamplona, Reinald; Barja, Gustavo

    2006-06-01

    Previous studies have consistently shown that caloric restriction (CR) decreases mitochondrial reactive oxygen species (ROS) (mitROS) generation and oxidative damage to mtDNA and mitochondrial proteins, and increases maximum longevity, although the mechanisms responsible for this are unknown. We recently found that protein restriction (PR) also produces these changes independent of energy restriction. Various facts link methionine to aging, and methionine restriction (MetR) without energy restriction increases, like CR, maximum longevity. We have thus hypothesized that MetR is responsible for the decrease in mitROS generation and oxidative stress in PR and CR. In this investigation we subjected male rats to exactly the same dietary protocol of MetR that is known to increase their longevity. We have found, for the first time, that MetR profoundly decreases mitROS production, decreases oxidative damage to mtDNA, lowers membrane unsaturation, and decreases all five markers of protein oxidation measured in rat heart and liver mitochondria. The concentration of complexes I and IV also decreases in MetR. The decrease in mitROS generation occurs in complexes I and III in liver and in complex I in heart mitochondria, and is due to an increase in efficiency of the respiratory chain in avoiding electron leak to oxygen. These changes are strikingly similar to those observed in CR and PR, suggesting that the decrease in methionine ingestion is responsible for the decrease in mitochondrial ROS production and oxidative stress, and possibly part of the decrease in aging rate, occurring during caloric restriction.

  10. Mitochondrial function and energy metabolism in neuronal HT22 cells resistant to oxidative stress

    PubMed Central

    Pfeiffer, Annika; Jaeckel, Martin; Lewerenz, Jan; Noack, Rebecca; Pouya, Alireza; Schacht, Teresa; Hoffmann, Christina; Winter, Jennifer; Schweiger, Susann; Schäfer, Michael K E; Methner, Axel

    2014-01-01

    Background and Purpose The hippocampal cell line HT22 is an excellent model for studying the consequences of endogenous oxidative stress. Extracellular glutamate depletes cellular glutathione by blocking the glutamate/cystine antiporter system xc−. Glutathione depletion induces a well-defined programme of cell death characterized by an increase in reactive oxygen species and mitochondrial dysfunction. Experimental Approach We compared the mitochondrial shape, the abundance of mitochondrial complexes and the mitochondrial respiration of HT22 cells, selected based on their resistance to glutamate, with those of the glutamate-sensitive parental cell line. Key Results Glutamate-resistant mitochondria were less fragmented and displayed seemingly contradictory features: mitochondrial calcium and superoxide were increased while high-resolution respirometry suggested a reduction in mitochondrial respiration. This was interpreted as a reverse activity of the ATP synthase under oxidative stress, leading to hydrolysis of ATP to maintain or even elevate the mitochondrial membrane potential, suggesting these cells endure ineffective energy metabolism to protect their membrane potential. Glutamate-resistant cells were also resistant to oligomycin, an inhibitor of the ATP synthase, but sensitive to deoxyglucose, an inhibitor of hexokinases. Exchanging glucose with galactose rendered resistant cells 1000-fold more sensitive to oligomycin. These results, together with a strong increase in cytosolic hexokinase 1 and 2, a reduced lactate production and an increased activity of glucose-6-phosphate dehydrogenase, suggest that glutamate-resistant HT22 cells shuttle most available glucose towards the hexose monophosphate shunt to increase glutathione recovery. Conclusions and Implications These results indicate that mitochondrial and metabolic adaptations play an important role in the resistance of cells to oxidative stress. Linked Articles This article is part of a themed issue on

  11. Aluminium induced oxidative stress results in decreased mitochondrial biogenesis via modulation of PGC-1α expression.

    PubMed

    Sharma, Deep Raj; Sunkaria, Aditya; Wani, Willayat Yousuf; Sharma, Reeta Kumari; Kandimalla, Ramesh J L; Bal, Amanjit; Gill, Kiran Dip

    2013-12-01

    The present investigation was carried out to elucidate a possible molecular mechanism related to the effects of aluminium-induced oxidative stress on various mitochondrial respiratory complex subunits with special emphasis on the role of Peroxisome proliferator activated receptor gamma co-activator 1α (PGC-1α) and its downstream targets i.e. Nuclear respiratory factor-1(NRF-1), Nuclear respiratory factor-2(NRF-2) and Mitochondrial transcription factor A (Tfam) in mitochondrial biogenesis. Aluminium lactate (10mg/kgb.wt./day) was administered intragastrically to rats for 12 weeks. After 12 weeks of exposure, we found an increase in ROS levels, mitochondrial DNA oxidation and decrease in citrate synthase activity in the Hippocampus (HC) and Corpus striatum (CS) regions of rat brain. On the other hand, there was a decrease in the mRNA levels of the mitochondrial encoded subunits-NADH dehydrogenase (ND) subunits i.e. ND1, ND2, ND3, Cytochrome b (Cytb), Cytochrome oxidase (COX) subunits i.e. COX1, COX3, ATP synthase (ATPase) subunit 6 along with reduced expression of nuclear encoded subunits COX4, COX5A, COX5B of Electron transport chain (ETC). Besides, a decrease in mitochondrial DNA copy number and mitochondrial content in both regions of rat brain was observed. The PGC-1α was down-regulated in aluminium treated rats along with NRF-1, NRF-2 and Tfam, which act downstream from PGC-1α in aluminium treated rats. Electron microscopy results revealed a significant increase in the mitochondrial swelling, loss of cristae, chromatin condensation and decreases in mitochondrial number in case of aluminium treated rats as compared to control. So, PGC-1α seems to be a potent target for aluminium neurotoxicity, which makes it an almost ideal target to control or limit the damage that has been associated with the defective mitochondrial function seen in neurodegenerative diseases. © 2013.

  12. FABP4 reversed the regulation of leptin on mitochondrial fatty acid oxidation in mice adipocytes.

    PubMed

    Gan, Lu; Liu, Zhenjiang; Cao, Weina; Zhang, Zhenzhen; Sun, Chao

    2015-08-27

    Fatty acid binding protein 4 (FABP4), plays key role in fatty acid transportation and oxidation, and increases with leptin synergistically during adipose inflammation process. However, the regulation mechanism between FABP4 and leptin on mitochondrial fatty acid oxidation remains unclear. In this study, we found that FABP4 reduced the expression of leptin, CPT-1 and AOX1 in mice adipocytes. Conversely, FABP4 was down-regulated in a time-dependent manner by leptin treatment. Additionally, forced expression of FABP4 attenuated the expression of PGC1-α, UCP2, CPT-1, AOX1 and COX2 compared with leptin incubation. Moreover, mitochondrial membrane potential, fatty acid oxidation enzyme medium-chain acyl-CoA dehydrogenase (MCAD), long-chain acyl-CoA dehydrogenase (LCAD) and Cyt C levels were reduced in response to the overexpression of FABP4. These reductions correspond well with the reduced release of free fatty acid and the inactivation of mitochondrial complexes I and III by FABP4 overexpression. Furthermore, addition of the Akt/mTOR pathway-specific inhibitor (MK2206) blocked the mitochondrial fatty acid oxidation and respiration factors, whereas interference of FABP4 overcame these effects. Taken together, FABP4 could reverse the activation of the leptin-induced mitochondrial fatty acid oxidation, and the inhibition of Akt/mTOR signal pathway played a key role in this process.

  13. FABP4 reversed the regulation of leptin on mitochondrial fatty acid oxidation in mice adipocytes

    PubMed Central

    Gan, Lu; Liu, Zhenjiang; Cao, Weina; Zhang, Zhenzhen; Sun, Chao

    2015-01-01

    Fatty acid binding protein 4 (FABP4), plays key role in fatty acid transportation and oxidation, and increases with leptin synergistically during adipose inflammation process. However, the regulation mechanism between FABP4 and leptin on mitochondrial fatty acid oxidation remains unclear. In this study, we found that FABP4 reduced the expression of leptin, CPT-1 and AOX1 in mice adipocytes. Conversely, FABP4 was down-regulated in a time-dependent manner by leptin treatment. Additionally, forced expression of FABP4 attenuated the expression of PGC1-α, UCP2, CPT-1, AOX1 and COX2 compared with leptin incubation. Moreover, mitochondrial membrane potential, fatty acid oxidation enzyme medium-chain acyl-CoA dehydrogenase (MCAD), long-chain acyl-CoA dehydrogenase (LCAD) and Cyt C levels were reduced in response to the overexpression of FABP4. These reductions correspond well with the reduced release of free fatty acid and the inactivation of mitochondrial complexes I and III by FABP4 overexpression. Furthermore, addition of the Akt/mTOR pathway-specific inhibitor (MK2206) blocked the mitochondrial fatty acid oxidation and respiration factors, whereas interference of FABP4 overcame these effects. Taken together, FABP4 could reverse the activation of the leptin-induced mitochondrial fatty acid oxidation, and the inhibition of Akt/mTOR signal pathway played a key role in this process. PMID:26310911

  14. Impaired Mitochondrial Energy Production Causes Light-Induced Photoreceptor Degeneration Independent of Oxidative Stress.

    PubMed

    Jaiswal, Manish; Haelterman, Nele A; Sandoval, Hector; Xiong, Bo; Donti, Taraka; Kalsotra, Auinash; Yamamoto, Shinya; Cooper, Thomas A; Graham, Brett H; Bellen, Hugo J

    2015-07-01

    Two insults often underlie a variety of eye diseases including glaucoma, optic atrophy, and retinal degeneration--defects in mitochondrial function and aberrant Rhodopsin trafficking. Although mitochondrial defects are often associated with oxidative stress, they have not been linked to Rhodopsin trafficking. In an unbiased forward genetic screen designed to isolate mutations that cause photoreceptor degeneration, we identified mutations in a nuclear-encoded mitochondrial gene, ppr, a homolog of human LRPPRC. We found that ppr is required for protection against light-induced degeneration. Its function is essential to maintain membrane depolarization of the photoreceptors upon repetitive light exposure, and an impaired phototransduction cascade in ppr mutants results in excessive Rhodopsin1 endocytosis. Moreover, loss of ppr results in a reduction in mitochondrial RNAs, reduced electron transport chain activity, and reduced ATP levels. Oxidative stress, however, is not induced. We propose that the reduced ATP level in ppr mutants underlies the phototransduction defect, leading to increased Rhodopsin1 endocytosis during light exposure, causing photoreceptor degeneration independent of oxidative stress. This hypothesis is bolstered by characterization of two other genes isolated in the screen, pyruvate dehydrogenase and citrate synthase. Their loss also causes a light-induced degeneration, excessive Rhodopsin1 endocytosis and reduced ATP without concurrent oxidative stress, unlike many other mutations in mitochondrial genes that are associated with elevated oxidative stress and light-independent photoreceptor demise.

  15. Mitochondrial Dysfunction in Cancer and Neurodegenerative Diseases: Spotlight on Fatty Acid Oxidation and Lipoperoxidation Products

    PubMed Central

    Barrera, Giuseppina; Gentile, Fabrizio; Pizzimenti, Stefania; Canuto, Rosa Angela; Daga, Martina; Arcaro, Alessia; Cetrangolo, Giovanni Paolo; Lepore, Alessio; Ferretti, Carlo; Dianzani, Chiara; Muzio, Giuliana

    2016-01-01

    In several human diseases, such as cancer and neurodegenerative diseases, the levels of reactive oxygen species (ROS), produced mainly by mitochondrial oxidative phosphorylation, is increased. In cancer cells, the increase of ROS production has been associated with mtDNA mutations that, in turn, seem to be functional in the alterations of the bioenergetics and the biosynthetic state of cancer cells. Moreover, ROS overproduction can enhance the peroxidation of fatty acids in mitochondrial membranes. In particular, the peroxidation of mitochondrial phospholipid cardiolipin leads to the formation of reactive aldehydes, such as 4-hydroxynonenal (HNE) and malondialdehyde (MDA), which are able to react with proteins and DNA. Covalent modifications of mitochondrial proteins by the products of lipid peroxidation (LPO) in the course of oxidative cell stress are involved in the mitochondrial dysfunctions observed in cancer and neurodegenerative diseases. Such modifications appear to affect negatively mitochondrial integrity and function, in particular energy metabolism, adenosine triphosphate (ATP) production, antioxidant defenses and stress responses. In neurodegenerative diseases, indirect confirmation for the pathogenetic relevance of LPO-dependent modifications of mitochondrial proteins comes from the disease phenotypes associated with their genetic alterations. PMID:26907355

  16. Crystal structures of oxidized and reduced forms of human mitochondrial thioredoxin 2

    PubMed Central

    Smeets, Aude; Evrard, Christine; Landtmeters, Marie; Marchand, Cécile; Knoops, Bernard; Declercq, Jean-Paul

    2005-01-01

    Mammalian thioredoxin 2 is a mitochondrial isoform of highly evolutionary conserved thioredoxins. Thioredoxins are small ubiquitous protein–disulfide oxidoreductases implicated in a large variety of biological functions. In mammals, thioredoxin 2 is encoded by a nuclear gene and is targeted to mitochondria by a N-terminal mitochondrial presequence. Recently, mitochondrial thioredoxin 2 was shown to interact with components of the mitochondrial respiratory chain and to play a role in the control of mitochondrial membrane potential, regulating mitochondrial apoptosis signaling pathway. Here we report the first crystal structures of a mammalian mitochondrial thioredoxin 2. Crystal forms of reduced and oxidized human thioredoxin 2 are described at 2.0 and 1.8 Å resolution. Though the folding is rather similar to that of human cytosolic/nuclear thioredoxin 1, important differences are observed during the transition between the oxidized and the reduced states of human thioredoxin 2, compared with human thioredoxin 1. In spite of the absence of the Cys residue implicated in dimer formation in human thioredoxin 1, dimerization still occurs in the crystal structure of human thioredoxin 2, mainly mediated by hydrophobic contacts, and the dimers are associated to form two-dimensional polymers. Interestingly, the structure of human thioredoxin 2 reveals possible interaction domains with human peroxiredoxin 5, a substrate protein of human thioredoxin 2 in mitochondria. PMID:16195549

  17. Cardioprotective effects of Notoginsenoside R1 against ischemia/reperfusion injuries by regulating oxidative stress- and endoplasmic reticulum stress- related signaling pathways

    PubMed Central

    Yu, Yingli; Sun, Guibo; Luo, Yun; Wang, Min; Chen, Rongchang; Zhang, Jingyi; Ai, Qidi; Xing, Na; Sun, Xiaobo

    2016-01-01

    Background: Recent reports suggested the involvement of oxidative stress- and endoplasmic reticulum stress (ERS)-associated pathways in the progression of ischemia/reperfusion (I/R) injury. Notoginsenoside R1 (NGR1) is a novel saponin isolated from P. notoginseng, which has a history of prevention and treatment of cardiovascular diseases. Objective: We aimed to examine the cardioprotective effects of NGR1 on I/R-induced heart dysfunction ex vivo and in vitro. Methods: H9c2 cadiomyocytes were incubated with NGR1 for 24 h and exposed to hypoxia/reoxygenation. Isolated rat hearts were perfused by NGR1 for 15 min and then subjected to global ischemia/reperfusion. Hemodynamic parameters were monitored as left ventricular systolic pressure (LVSP), heart rate, and maximal rate of increase and decrease of left ventricular pressure (±dP/dt max/min). Results: NGR1 pretreatment prevents cell apoptosis and delays the onset of ERS by decreasing the protein expression levels of ERS-responsive proteins GRP78, P-PERK, ATF6, IRE, and inhibiting the expression of pro-apoptosis proteins CHOP, Caspase-12, and P-JNK. Besides, NGR1 scavenges free radical, and increases the activity of antioxidase. NGR1 inhibits Tunicamycin-induced cell death and cardic dysfunction. Conclusion: We elucidated the significant cardioprotective effects of NGR1 against I/R injuries, and demonstrated the involvement of oxidative stress and ERS in the protective effects of NGR1. PMID:26888485

  18. Aluminium induced oxidative stress results in decreased mitochondrial biogenesis via modulation of PGC-1α expression

    SciTech Connect

    Sharma, Deep Raj; Sunkaria, Aditya; Wani, Willayat Yousuf; Sharma, Reeta Kumari; Kandimalla, Ramesh J.L.; Bal, Amanjit; Gill, Kiran Dip

    2013-12-01

    The present investigation was carried out to elucidate a possible molecular mechanism related to the effects of aluminium-induced oxidative stress on various mitochondrial respiratory complex subunits with special emphasis on the role of Peroxisome proliferator activated receptor gamma co-activator 1α (PGC-1α) and its downstream targets i.e. Nuclear respiratory factor-1(NRF-1), Nuclear respiratory factor-2(NRF-2) and Mitochondrial transcription factor A (Tfam) in mitochondrial biogenesis. Aluminium lactate (10 mg/kg b.wt./day) was administered intragastrically to rats for 12 weeks. After 12 weeks of exposure, we found an increase in ROS levels, mitochondrial DNA oxidation and decrease in citrate synthase activity in the Hippocampus (HC) and Corpus striatum (CS) regions of rat brain. On the other hand, there was a decrease in the mRNA levels of the mitochondrial encoded subunits–NADH dehydrogenase (ND) subunits i.e. ND1, ND2, ND3, Cytochrome b (Cytb), Cytochrome oxidase (COX) subunits i.e. COX1, COX3, ATP synthase (ATPase) subunit 6 along with reduced expression of nuclear encoded subunits COX4, COX5A, COX5B of Electron transport chain (ETC). Besides, a decrease in mitochondrial DNA copy number and mitochondrial content in both regions of rat brain was observed. The PGC-1α was down-regulated in aluminium treated rats along with NRF-1, NRF-2 and Tfam, which act downstream from PGC-1α in aluminium treated rats. Electron microscopy results revealed a significant increase in the mitochondrial swelling, loss of cristae, chromatin condensation and decreases in mitochondrial number in case of aluminium treated rats as compared to control. So, PGC-1α seems to be a potent target for aluminium neurotoxicity, which makes it an almost ideal target to control or limit the damage that has been associated with the defective mitochondrial function seen in neurodegenerative diseases. - Highlights: • Aluminium decreases the mRNA levels of mitochondrial and nuclear encoded

  19. Mitochondrial dysfunction and oxidative stress in metabolic disorders - A step towards mitochondria based therapeutic strategies.

    PubMed

    Bhatti, Jasvinder Singh; Bhatti, Gurjit Kaur; Reddy, P Hemachandra

    2016-11-09

    Mitochondria are the powerhouses of the cell and are involved in essential functions of the cell, including ATP production, intracellular Ca(2+) regulation, reactive oxygen species production & scavenging, regulation of apoptotic cell death and activation of the caspase family of proteases. Mitochondrial dysfunction and oxidative stress are largely involved in aging, cancer, age-related neurodegenerative and metabolic syndrome. In the last decade, tremendous progress has been made in understanding mitochondrial structure, function and their physiology in metabolic syndromes such as diabetes, obesity, stroke and hypertension, and heart disease. Further, progress has also been made in developing therapeutic strategies, including lifestyle interventions (healthy diet and regular exercise), pharmacological strategies and mitochondria-targeted approaches. These strategies were mainly focused to reduce mitochondrial dysfunction and oxidative stress and to maintain mitochondrial quality in metabolic syndromes. The purpose of our article is to highlight the recent progress on the mitochondrial role in metabolic syndromes and also summarize the progress of mitochondria-targeted molecules as therapeutic targets to treat metabolic syndromes. This article is part of a Special Issue entitled: Oxidative Stress and Mitochondrial Quality in Diabetes/Obesity and Critical Illness Spectrum of Diseases - edited by P. Hemachandra Reddy.

  20. Mitochondrial targeting of bilirubin regulatory enzymes: An adaptive response to oxidative stress.

    PubMed

    Muhsain, Siti Nur Fadzilah; Lang, Matti A; Abu-Bakar, A'edah

    2015-01-01

    The intracellular level of bilirubin (BR), an endogenous antioxidant that is cytotoxic at high concentrations, is tightly controlled within the optimal therapeutic range. We have recently described a concerted intracellular BR regulation by two microsomal enzymes: heme oxygenase 1 (HMOX1), essential for BR production and cytochrome P450 2A5 (CYP2A5), a BR oxidase. Herein, we describe targeting of these enzymes to hepatic mitochondria during oxidative stress. The kinetics of microsomal and mitochondrial BR oxidation were compared. Treatment of DBA/2J mice with 200mgpyrazole/kg/day for 3days increased hepatic intracellular protein carbonyl content and induced nucleo-translocation of Nrf2. HMOX1 and CYP2A5 proteins and activities were elevated in microsomes and mitoplasts but not the UGT1A1, a catalyst of BR glucuronidation. A CYP2A5 antibody inhibited 75% of microsomal BR oxidation. The inhibition was absent in control mitoplasts but elevated to 50% after treatment. An adrenodoxin reductase antibody did not inhibit microsomal BR oxidation but inhibited 50% of mitochondrial BR oxidation. Ascorbic acid inhibited 5% and 22% of the reaction in control and treated microsomes, respectively. In control mitoplasts the inhibition was 100%, which was reduced to 50% after treatment. Bilirubin affinity to mitochondrial and microsomal CYP2A5 enzyme is equally high. Lastly, the treatment neither released cytochrome c into cytoplasm nor dissipated membrane potential, indicating the absence of mitochondrial membrane damage. Collectively, the observations suggest that BR regulatory enzymes are recruited to mitochondria during oxidative stress and BR oxidation by mitochondrial CYP2A5 is supported by mitochondrial mono-oxygenase system. The induced recruitment potentially confers membrane protection. Crown Copyright © 2014. Published by Elsevier Inc. All rights reserved.

  1. Effects of Cigarette Smoke on the Activation of Oxidative Stress-Related Transcription Factors in Female A/J Mouse Lung

    PubMed Central

    Tharappel, Job C.; Cholewa, Jill; Espandiari, Parvaneh; Spear, Brett T.; Gairola, C. Gary; Glauert, Howard P.

    2010-01-01

    Cigarette smoke contains a high concentration of free radicals and induces oxidative stress in the lung and other tissues. Several transcription factors are known to be activated by oxidative stress, including nuclear factor-κB (NF-κB), activator protein-1 (AP-1), and hypoxia-inducible factor (HIF). Studies were therefore undertaken to examine if cigarette smoke could activate these transcription factors, as well as other transcription factors that may be important in lung carcinogenesis. Female A/J mice were exposed to cigarette smoke for 2, 5, 10, 15, 20, 42, or 56 days (6 hr/day, 5 days/wk). Cigarette smoke did not increase NF-κB activation at any of these times, but NF-κB DNA binding activity was lower after 15 days and 56 days of smoke exposure. The DNA binding activity of AP-1 was lower after 10 days and 56 days but was not changed after 42 days of smoke exposure. The DNA binding activity of HIF was quantitatively increased after 42 days of smoke exposure but decreased after 56 days. Whether the activation of other transcription factors in the lung could be altered after exposure to cigarette smoke was subsequently examined. The DNA binding activities of FoxF2, myc-CF1, RORE, and p53 were examined after 10 days of smoke exposure. The DNA binding activities of FoxF2 and p53 were quantitatively increased, but those of myc-CF1 and RORE were unaffected. These studies show that cigarette smoke exposure leads to quantitative increases in DNA binding activities of FoxF2 and p53, while the activations of NF-κB, AP-1, and HIF are largely unaffected or reduced. PMID:20711931

  2. Role of skeletal muscle mitochondrial density on exercise-stimulated lipid oxidation.

    PubMed

    Galgani, Jose E; Johannsen, Neil M; Bajpeyi, Sudip; Costford, Sheila R; Zhang, Zhengyu; Gupta, Alok K; Ravussin, Eric

    2012-07-01

    Reduced skeletal muscle mitochondrial density is proposed to lead to impaired muscle lipid oxidation and increased lipid accumulation in sedentary individuals. We assessed exercise-stimulated lipid oxidation by imposing a prolonged moderate-intensity exercise in men with variable skeletal muscle mitochondrial density as measured by citrate synthase (CS) activity. After a 2-day isoenergetic high-fat diet, lipid oxidation was measured before and during exercise (650 kcal at 50% VO(2)max) in 20 healthy men with either high (HI-CS = 24 ± 1; mean ± s.e.) or low (LO-CS = 17 ± 1 nmol/min/mg protein) muscle CS activity. Vastus lateralis muscle biopsies were obtained before and immediately after exercise. Respiratory exchange data and blood samples were collected at rest and throughout the exercise. HI-CS subjects had higher VO(2)max (50 ± 1 vs. 44 ± 2 ml/kg fat free mass/min; P = 0.01), lower fasting respiratory quotient (RQ) (0.81 ± 0.01 vs. 0.85 ± 0.01; P = 0.04) and higher ex vivo muscle palmitate oxidation (866 ± 168 vs. 482 ± 78 nmol/h/mg muscle; P = 0.05) compared to LO-CS individuals. However, whole-body exercise-stimulated lipid oxidation (20 ± 2 g vs. 19 ± 1 g; P = 0.65) and plasma glucose, lactate, insulin, and catecholamine responses were similar between the two groups. In conclusion, in response to the same energy demand during a moderate prolonged exercise bout, reliance on lipid oxidation was similar in individuals with high and low skeletal muscle mitochondrial density. This data suggests that decreased muscle mitochondrial density may not necessarily impair reliance on lipid oxidation over the course of the day since it was normal under a high-lipid oxidative demand condition. Twenty-four-hour lipid oxidation and its relationship with mitochondrial density need to be assessed.

  3. Cellular Dysfunction in Diabetes as Maladaptive Response to Mitochondrial Oxidative Stress

    PubMed Central

    Naudi, Alba; Jove, Mariona; Ayala, Victoria; Cassanye, Anna; Serrano, Jose; Gonzalo, Hugo; Boada, Jordi; Prat, Joan; Portero-Otin, Manuel; Pamplona, Reinald

    2012-01-01

    Oxidative stress has been implicated in diabetes long-term complications. In this paper, we summarize the growing evidence suggesting that hyperglycemia-induced overproduction of superoxide by mitochondrial electron transport chain triggers a maladaptive response by affecting several metabolic and signaling pathways involved in the pathophysiology of cellular dysfunction and diabetic complications. In particular, it is our goal to describe physiological mechanisms underlying the mitochondrial free radical production and regulation to explain the oxidative stress derived from a high intracellular glucose concentration and the resulting maladaptive response that leads to a cellular dysfunction and pathological state. Finally, we outline potential therapies for diabetes focused to the prevention of mitochondrial oxidative damage. PMID:22253615

  4. Enalapril treatment discloses an early role of angiotensin II in inflammation- and oxidative stress-related muscle damage in dystrophic mdx mice☆

    PubMed Central

    Cozzoli, Anna; Nico, Beatrice; Sblendorio, Valeriana Teresa; Capogrosso, Roberta Francesca; Dinardo, Maria Maddalena; Longo, Vito; Gagliardi, Sara; Montagnani, Monica; De Luca, Annamaria

    2011-01-01

    Inhibitors of angiotensin converting enzymes (ACE) are clinically used to control cardiomyopathy in patients of Duchenne muscular dystrophy. Various evidences suggest potential usefulness of long-term treatment with ACE inhibitors to reduce advanced fibrosis of dystrophic muscle in the mdx mouse model. However, angiotensin II is known to exert pro-inflammatory and pro-oxidative actions that might contribute to early events of dystrophic muscle degeneration. The present study has been aimed at evaluating the effects of an early treatment with enalapril on the pathology signs of exercised mdx mouse model. The effects of 1 and 5 mg/kg enalapril i.p. for 4–8 weeks have been compared with those of 1 mg/kg α-methyl-prednisolone (PDN), as positive control. Enalapril caused a dose-dependent increase in fore limb strength, the highest dose leading to a recovery score similar to that observed with PDN. A dose-dependent reduction of superoxide anion production was observed by dihydroethidium staining in tibialis anterior muscle of enalapril-treated mice, approaching the effect observed with PND. In parallel, a significant reduction of the activated form of the pro-inflammatory Nuclear Factor-kB has been observed in gastrocnemious muscle. Histologically, 5 mg/kg enalapril reduced the area of muscle necrosis in both gastrocnemious muscle and diaphragm, without significant effect on non-muscle area. In parallel no significant changes have been observed in both muscle TGF-β1 and myonuclei positive to phosphorylated Smad2/3. Myofiber functional indices were also monitored by microelectrodes recordings. A dose-dependent recovery of macroscopic chloride conductance has been observed upon enalapril treatment in EDL muscle, with minor effects being exerted in diaphragm. However a modest effect, if any, was found on mechanical threshold, a functional index of calcium homeostasis. No recovery was observed in creatine kinase and lactate dehydrogenase. Finally the results suggest

  5. Oxidative stress-induced mitochondrial dysfunction drives inflammation and airway smooth muscle remodeling in patients with chronic obstructive pulmonary disease.

    PubMed

    Wiegman, Coen H; Michaeloudes, Charalambos; Haji, Gulammehdi; Narang, Priyanka; Clarke, Colin J; Russell, Kirsty E; Bao, Wuping; Pavlidis, Stelios; Barnes, Peter J; Kanerva, Justin; Bittner, Anton; Rao, Navin; Murphy, Michael P; Kirkham, Paul A; Chung, Kian Fan; Adcock, Ian M

    2015-09-01

    Inflammation and oxidative stress play critical roles in patients with chronic obstructive pulmonary disease (COPD). Mitochondrial oxidative stress might be involved in driving the oxidative stress-induced pathology. We sought to determine the effects of oxidative stress on mitochondrial function in the pathophysiology of airway inflammation in ozone-exposed mice and human airway smooth muscle (ASM) cells. Mice were exposed to ozone, and lung inflammation, airway hyperresponsiveness (AHR), and mitochondrial function were determined. Human ASM cells were isolated from bronchial biopsy specimens from healthy subjects, smokers, and patients with COPD. Inflammation and mitochondrial function in mice and human ASM cells were measured with and without the presence of the mitochondria-targeted antioxidant MitoQ. Mice exposed to ozone, a source of oxidative stress, had lung inflammation and AHR associated with mitochondrial dysfunction and reflected by decreased mitochondrial membrane potential (ΔΨm), increased mitochondrial oxidative stress, and reduced mitochondrial complex I, III, and V expression. Reversal of mitochondrial dysfunction by the mitochondria-targeted antioxidant MitoQ reduced inflammation and AHR. ASM cells from patients with COPD have reduced ΔΨm, adenosine triphosphate content, complex expression, basal and maximum respiration levels, and respiratory reserve capacity compared with those from healthy control subjects, whereas mitochondrial reactive oxygen species (ROS) levels were increased. Healthy smokers were intermediate between healthy nonsmokers and patients with COPD. Hydrogen peroxide induced mitochondrial dysfunction in ASM cells from healthy subjects. MitoQ and Tiron inhibited TGF-β-induced ASM cell proliferation and CXCL8 release. Mitochondrial dysfunction in patients with COPD is associated with excessive mitochondrial ROS levels, which contribute to enhanced inflammation and cell hyperproliferation. Targeting mitochondrial ROS represents

  6. Oxidative stress–induced mitochondrial dysfunction drives inflammation and airway smooth muscle remodeling in patients with chronic obstructive pulmonary disease

    PubMed Central

    Wiegman, Coen H.; Michaeloudes, Charalambos; Haji, Gulammehdi; Narang, Priyanka; Clarke, Colin J.; Russell, Kirsty E.; Bao, Wuping; Pavlidis, Stelios; Barnes, Peter J.; Kanerva, Justin; Bittner, Anton; Rao, Navin; Murphy, Michael P.; Kirkham, Paul A.; Chung, Kian Fan; Adcock, Ian M.; Brightling, Christopher E.; Davies, Donna E.; Finch, Donna K.; Fisher, Andrew J.; Gaw, Alasdair; Knox, Alan J.; Mayer, Ruth J.; Polkey, Michael; Salmon, Michael; Singh, David

    2015-01-01

    Background Inflammation and oxidative stress play critical roles in patients with chronic obstructive pulmonary disease (COPD). Mitochondrial oxidative stress might be involved in driving the oxidative stress–induced pathology. Objective We sought to determine the effects of oxidative stress on mitochondrial function in the pathophysiology of airway inflammation in ozone-exposed mice and human airway smooth muscle (ASM) cells. Methods Mice were exposed to ozone, and lung inflammation, airway hyperresponsiveness (AHR), and mitochondrial function were determined. Human ASM cells were isolated from bronchial biopsy specimens from healthy subjects, smokers, and patients with COPD. Inflammation and mitochondrial function in mice and human ASM cells were measured with and without the presence of the mitochondria-targeted antioxidant MitoQ. Results Mice exposed to ozone, a source of oxidative stress, had lung inflammation and AHR associated with mitochondrial dysfunction and reflected by decreased mitochondrial membrane potential (ΔΨm), increased mitochondrial oxidative stress, and reduced mitochondrial complex I, III, and V expression. Reversal of mitochondrial dysfunction by the mitochondria-targeted antioxidant MitoQ reduced inflammation and AHR. ASM cells from patients with COPD have reduced ΔΨm, adenosine triphosphate content, complex expression, basal and maximum respiration levels, and respiratory reserve capacity compared with those from healthy control subjects, whereas mitochondrial reactive oxygen species (ROS) levels were increased. Healthy smokers were intermediate between healthy nonsmokers and patients with COPD. Hydrogen peroxide induced mitochondrial dysfunction in ASM cells from healthy subjects. MitoQ and Tiron inhibited TGF-β–induced ASM cell proliferation and CXCL8 release. Conclusions Mitochondrial dysfunction in patients with COPD is associated with excessive mitochondrial ROS levels, which contribute to enhanced inflammation and cell

  7. Molecular pathophysiology of impaired glucose metabolism, mitochondrial dysfunction, and oxidative DNA damage in Alzheimer's disease brain.

    PubMed

    Abolhassani, Nona; Leon, Julio; Sheng, Zijing; Oka, Sugako; Hamasaki, Hideomi; Iwaki, Toru; Nakabeppu, Yusaku

    2017-01-01

    In normal brain, neurons in the cortex and hippocampus produce insulin, which modulates glucose metabolism and cognitive functions. It has been shown that insulin resistance impairs glucose metabolism and mitochondrial function, thus increasing production of reactive oxygen species. Recent progress in Alzheimer's disease (AD) research revealed that insulin production and signaling are severely impaired in AD brain, thereby resulting in mitochondrial dysfunction and increased oxidative stress. Among possible oxidative DNA lesions, 8-oxoguanine (8-oxoG) is highly accumulated in the brain of AD patients. Previously we have shown that incorporating 8-oxoG in nuclear and mitochondrial DNA promotes MUTYH (adenine DNA glycosylase) dependent neurodegeneration. Moreover, cortical neurons prepared from MTH1 (8-oxo-dGTPase)/OGG1 (8-oxoG DNA glycosylase)-double deficient adult mouse brains is shown to exhibit significantly poor neuritogenesis in vitro with increased 8-oxoG accumulation in mitochondrial DNA in the absence of antioxidants. Therefore, 8-oxoG can be considered involved in the neurodegenerative process in AD brain. In mild cognitive impairment, mitochondrial dysfunction and oxidative damage may induce synaptic dysfunction due to energy failures in neurons thus resulting in impaired cognitive function. If such abnormality lasts long, it can lead to vicious cycles of oxidative damage, which may then trigger the neurodegenerative process seen in Alzheimer type dementia. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  8. Mesenchymal stem cells alleviate oxidative stress-induced mitochondrial dysfunction in the airways.

    PubMed

    Li, Xiang; Michaeloudes, Charalambos; Zhang, Yuelin; Wiegman, Coen H; Adcock, Ian M; Lian, Qizhou; Mak, Judith C W; Bhavsar, Pankaj K; Chung, Kian Fan

    2017-09-11

    Oxidative stress-induced mitochondrial dysfunction may contribute to inflammation and remodeling in chronic obstructive pulmonary disease (COPD). Mesenchymal stem cells (MSCs) protect against lung damage in animal models of COPD. It is unknown whether these effects occur through attenuating mitochondrial dysfunction in airway cells. To examine the effect of induced-pluripotent stem cell-derived MSCs (iPSC-MSCs) on oxidative stress-induce mitochondrial dysfunction in human airway smooth muscle cells (ASMCs) in vitro and in mouse lungs in vivo. ASMCs were co-cultured with iPSC-MSCs in the presence of cigarette smoke medium (CSM), and mitochondrial reactive oxygen species (ROS), mitochondrial membrane potential (ΔΨm) and apoptosis were measured. Conditioned media from iPSC-MSCs and trans-well co-cultures were used to detect any paracrine effects. The effect of systemic injection of iPSC-MSCs on airway inflammation and hyper-responsiveness in ozone-exposed mice was also investigated. Co-culture of iPSC-MSCs with ASMCs attenuated CSM-induced mitochondrial ROS, apoptosis and ΔΨm loss in ASMCs. iPSC-MSC-conditioned media or trans-well co-cultures with iPSC-MSCs reduced CSM-induced mitochondrial ROS but not ΔΨm or apoptosis in ASMCs. Mitochondrial transfer from iPSC-MSCs to ASMCs was observed after direct co-culture and was enhanced by CSM. iPSC-MSCs attenuated ozone-induced mitochondrial dysfunction, airway hyper-responsiveness and inflammation in mouse lungs. iPSC-MSCs offered protection against oxidative stress-induced mitochondrial dysfunction in human ASMCs and in mouse lungs, whilst reducing airway inflammation and hyper-responsiveness. These effects are, at least partly, dependent on cell-cell contact that allows for mitochondrial transfer, and paracrine regulation. Therefore, iPSC-MSCs show promise as a therapy for oxidative stress-dependent lung diseases such as COPD. Copyright © 2017. Published by Elsevier Inc.

  9. AMPK controls exercise endurance, mitochondrial oxidative capacity, and skeletal muscle integrity.

    PubMed

    Lantier, Louise; Fentz, Joachim; Mounier, Rémi; Leclerc, Jocelyne; Treebak, Jonas T; Pehmøller, Christian; Sanz, Nieves; Sakakibara, Iori; Saint-Amand, Emmanuelle; Rimbaud, Stéphanie; Maire, Pascal; Marette, André; Ventura-Clapier, Renée; Ferry, Arnaud; Wojtaszewski, Jørgen F P; Foretz, Marc; Viollet, Benoit

    2014-07-01

    AMP-activated protein kinase (AMPK) is a sensor of cellular energy status that plays a central role in skeletal muscle metabolism. We used skeletal muscle-specific AMPKα1α2 double-knockout (mdKO) mice to provide direct genetic evidence of the physiological importance of AMPK in regulating muscle exercise capacity, mitochondrial function, and contraction-stimulated glucose uptake. Exercise performance was significantly reduced in the mdKO mice, with a reduction in maximal force production and fatigue resistance. An increase in the proportion of myofibers with centralized nuclei was noted, as well as an elevated expression of interleukin 6 (IL-6) mRNA, possibly consistent with mild skeletal muscle injury. Notably, we found that AMPKα1 and AMPKα2 isoforms are dispensable for contraction-induced skeletal muscle glucose transport, except for male soleus muscle. However, the lack of skeletal muscle AMPK diminished maximal ADP-stimulated mitochondrial respiration, showing an impairment at complex I. This effect was not accompanied by changes in mitochondrial number, indicating that AMPK regulates muscle metabolic adaptation through the regulation of muscle mitochondrial oxidative capacity and mitochondrial substrate utilization but not baseline mitochondrial muscle content. Together, these results demonstrate that skeletal muscle AMPK has an unexpected role in the regulation of mitochondrial oxidative phosphorylation that contributes to the energy demands of the exercising muscle.-Lantier, L., Fentz, J., Mounier, R., Leclerc, J., Treebak, J. T., Pehmøller, C., Sanz, N., Sakakibara, I., Saint-Amand, E., Rimbaud, S., Maire, P., Marette, A., Ventura-Clapier, R., Ferry, A., Wojtaszewski, J. F. P., Foretz, M., Viollet, B. AMPK controls exercise endurance, mitochondrial oxidative capacity, and skeletal muscle integrity. © FASEB.

  10. Glyceraldehyde-3-phosphate Dehydrogenase (GAPDH) Aggregation Causes Mitochondrial Dysfunction during Oxidative Stress-induced Cell Death*

    PubMed Central

    Itakura, Masanori; Kubo, Takeya; Kaneshige, Akihiro; Harada, Naoki; Izawa, Takeshi; Azuma, Yasu-Taka; Kuwamura, Mitsuru; Yamaji, Ryouichi; Takeuchi, Tadayoshi

    2017-01-01

    Glycolytic glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is a multifunctional protein that also mediates cell death under oxidative stress. We reported previously that the active-site cysteine (Cys-152) of GAPDH plays an essential role in oxidative stress-induced aggregation of GAPDH associated with cell death, and a C152A-GAPDH mutant rescues nitric oxide (NO)-induced cell death by interfering with the aggregation of wild type (WT)-GAPDH. However, the detailed mechanism underlying GAPDH aggregate-induced cell death remains elusive. Here we report that NO-induced GAPDH aggregation specifically causes mitochondrial dysfunction. First, we observed a correlation between NO-induced GAPDH aggregation and mitochondrial dysfunction, when GAPDH aggregation occurred at mitochondria in SH-SY5Y cells. In isolated mitochondria, aggregates of WT-GAPDH directly induced mitochondrial swelling and depolarization, whereas mixtures containing aggregates of C152A-GAPDH reduced mitochondrial dysfunction. Additionally, treatment with cyclosporin A improved WT-GAPDH aggregate-induced swelling and depolarization. In doxycycline-inducible SH-SY5Y cells, overexpression of WT-GAPDH augmented NO-induced mitochondrial dysfunction and increased mitochondrial GAPDH aggregation, whereas induced overexpression of C152A-GAPDH significantly suppressed mitochondrial impairment. Further, NO-induced cytochrome c release into the cytosol and nuclear translocation of apoptosis-inducing factor from mitochondria were both augmented in cells overexpressing WT-GAPDH but ameliorated in C152A-GAPDH-overexpressing cells. Interestingly, GAPDH aggregates induced necrotic cell death via a permeability transition pore (PTP) opening. The expression of either WT- or C152A-GAPDH did not affect other cell death pathways associated with protein aggregation, such as proteasome inhibition, gene expression induced by endoplasmic reticulum stress, or autophagy. Collectively, these results suggest that NO-induced GAPDH

  11. Mechanism study on mitochondrial fragmentation under oxidative stress caused by high-fluence low-power laser irradiation

    NASA Astrophysics Data System (ADS)

    Wu, Shengnan; Zhou, Feifan; Xing, Da

    2012-03-01

    Mitochondria are dynamic organelles that undergo continual fusion and fission to maintain their morphology and functions, but the mechanism involved is still not clear. Here, we investigated the effect of mitochondrial oxidative stress triggered by high-fluence low-power laser irradiation (HF-LPLI) on mitochondrial dynamics in human lung adenocarcinoma cells (ASTC-a-1). Upon HF-LPLI-triggered oxidative stress, mitochondria displayed a fragmented structure, which was abolished by exposure to dehydroascorbic acid (DHA), a reactive oxygen species scavenger, indicating that oxidative stress can induce mitochondrial fragmentation. Mitochondrial translocation of the profission protein dynamin-related protein 1 (Drp1) was observed following HF-LPLI, demonstrating apoptosis-related activation of Drp1. Notably, DHA pre-treatment prevented HF-LPLI-induced Drp1 activation. We conclude that mitochondrial oxidative stress through activation of Drp1 causes mitochondrial fragmentation.

  12. Curcumin alleviates lipopolysaccharide induced sepsis and liver failure by suppression of oxidative stress-related inflammation via PI3K/AKT and NF-κB related signaling.

    PubMed

    Zhong, Wenhui; Qian, Kejian; Xiong, Jibin; Ma, Ke; Wang, Aizhong; Zou, Yan

    2016-10-01

    In many liver disorders, oxidative stress-related inflammation and apoptosis are important pathogenic components, finally resulting in acute liver failure. Erythropoietin and its analogues are well known to influence the interaction between apoptosis and inflammation in brain and kidney. The study is to clarify the effect of curcumin, a natural plant phenolic food additive, on lipopolysaccharides (LPS)-induced acute liver injury of mice with endotoxemia and associated molecular mechanism from inflammation, apoptosis and oxidative stress levels. And curcumin, lowered serum cytokines, including Interleukin 1beta (IL-1β), Interleukin 6 (IL-6) and tumor necrosis factor (TNF-α), and improved liver apoptosis through suppressing phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT) signaling pathway and inhibiting Cyclic AMP-responsive element-binding protein (CREB)/Caspase expression, and decreased oxidative stress-associated protein expression, mainly involving 2E1 isoform of cytochrome P450/nuclear factor E2-related factor 2/reactive oxygen species (CYP2E/Nrf2/ROS) signaling pathway, as well as liver nitric oxide (NO) production in LPS-induced mice. Moreover, curcumin regulated serum alanine transaminase (ALT), aspartate transaminase (AST) and alkaline phosphatase (ALP), accelerated liver antioxidant enzymes, such as superoxide dismutase (SOD), catalase (CAT), glutathione (GSH) and glutathione peroxidase (GSH-px) levels, and inhibited activation of the mitogen-activated protein kinases/c-Jun NH2-terminal kinase (P38/JNK) cascade in the livers of LPS-induced rats. Thus, curcumin treatment attenuates LPS-induced PI3K/AKT and CYP2E/Nrf2/ROS signaling and liver injury. Strategies to inhibit inflammation and apoptosis signaling may provide alternatives to the current clinical approaches to improve oxidative responses of endotoxemia.

  13. Mitochondrial and peroxisomal fatty acid oxidation in liver homogenates and isolated hepatocytes from control and clofibrate-treated rats.

    PubMed

    Mannaerts, G P; Debeer, L J; Thomas, J; De Schepper, P J

    1979-06-10

    Mitochondrial and peroxisomal fatty acid oxidation were compared in whole liver homogenates. Oxidation of 0.2 mM palmitoyl-CoA or oleate by mitochondria increased rapidly with increasing molar substrate:albumin ratios and became saturated at ratios below 3, while peroxisomal oxidation increased more slowly and continued to rise to reach maximal activity in the absence of albumin. Under the latter condition mitochondrial oxidation was severely depressed. In homogenates from normal liver peroxisomal oxidation was lower than mitochondrial oxidation at all ratios tested except when albumin was absent. In contrast with mitochondrial oxidation, peroxisomal oxidation did not produce ketones, was cyanide-insensitive, was not dependent on carnitine, and was not inhibited by (+)-octanoylcarnitine, malonyl-CoA and 4-pentenoate. Mitochondrial oxidation was inhibited by CoASH concentrations that were optimal for peroxisomal oxidation. In the presence of albumin, peroxisomal oxidation was stimulated by Triton X-100 but unaffected by freeze-thawing; both treatments suppressed mitochondrial oxidation. Clofibrate treatment increased mitochondrial and peroxisomal oxidation 2- and 6- to 8-fold, respectively. Peroxisomal oxidation remained unchanged in starvation and diabetes. Fatty acid oxidation was severely depressed by cyanide and (+)-octanoylcarnitine in hepatocytes from normal rats. Hepatocytes from clofibrate-treated rats, which displayed a 3- to 4-fold increase in fatty acid oxidation, were less inhibited by (+)-octanoylcarnitine. Hydrogen peroxide production was severalfold higher in hepatocytes from treated animals oxidizing fatty acids than in control hepatocytes. Assuming that all H2O2 produced during fatty acid oxidation was due to peroxisomal oxidation, it was calculated that the contribution of the peroxisomes to fatty acid oxidation was less than 10% both in cells from control and clofibrate-treated animals.

  14. Leptin's activity on the hydroxyl radical: a possible link to the oxidative stress-related endothelial vasodilation in patients with obstructive sleep apnea.

    PubMed

    Macrea, Madalina; Martin, Thomas; Jia, Zhenquan; Misra, Hara

    2013-08-01

    Obstructive sleep apnea (OSA) is associated with increased cardiovascular morbidity, whereas the underlying mechanism is still eluding, the thought participants are chronic intermittent hypoxia with consequent increase in the reactive oxygen species, leading to endothelial cell damage and dysfunction in these patients. As the hydroxyl radical (·OH) mediates the vascular smooth muscle relaxation, identification of its scavengers might reveal sentinel markers of decreased vascular responsiveness and worse long-term comorbid outcome. We therefore assessed leptin's scavenger effect on (∙)OH using the electronic paramagnetic resonance (EPR) method. The (∙)OH was generated by the Fenton reaction in the presence of spin-trap 5-diethoxyphosphoryl-5-methyl-1-pyrroline N-oxide (DMPO) with various concentrations of leptin (0.25, 2.5, and 25 μg/ml) and without leptin. EPR spectrometer settings were: modulation frequency, 100 kHz; X band microwave frequency, 9.5 GHz; microwave power, 20 mW (milliwatts); modulation amplitude, 1.0 G (gauss); time constant, 160 s; scan time, 200 s; and receiver gain, 1 × l0(5). EPR signal intensity between 3,440 and 3,540 G of measurements taken in at least three separate experiments was reported. Mannitol, a known (∙)OH scavenger, at 100 mM significantly decreased the DMPO-OH adduct formation and was used as the active-control agent. Leptin added to aqueous solutions at all concentrations was associated with a statistically significant decrease in EPR signal compared with controls due to its scavenging activity towards the ·OH. Leptin could be further investigated as a sentinel biomarker of decreased vascular responsiveness and future risk of atherosclerotic disease in obese OSA patients.

  15. Role of oxidative DNA damage in mitochondrial dysfunction and Huntington's disease pathogenesis.

    PubMed

    Ayala-Peña, Sylvette

    2013-09-01

    Huntington's disease (HD) is a neurodegenerative disorder with an autosomal dominant expression pattern and typically a late-onset appearance. HD is a movement disorder with a heterogeneous phenotype characterized by involuntary dance-like gait, bioenergetic deficits, motor impairment, and cognitive and psychiatric deficits. Compelling evidence suggests that increased oxidative stress and mitochondrial dysfunction may underlie HD pathogenesis. However, the exact mechanisms underlying mutant huntingtin-induced neurological toxicity remain unclear. The objective of this paper is to review recent literature regarding the role of oxidative DNA damage in mitochondrial dysfunction and HD pathogenesis.

  16. Nox2 as a potential target of mitochondrial superoxide and its role in endothelial oxidative stress

    PubMed Central

    Nazarewicz, Rafal R.; Bikineyeva, Alfiya; Dikalov, Sergey I.

    2013-01-01

    Superoxide (O2·−) production by the NADPH oxidases is implicated in the pathogenesis of many cardiovascular diseases, including hypertension. We have previously shown that activation of NADPH oxidases increases mitochondrial O2·− which is inhibited by the ATP-sensitive K+ channel (mitoKATP) inhibitor 5-hydroxydecanoic acid and that scavenging of mitochondrial or cytoplasmic O2·− inhibits hypertension. We hypothesized that mitoKATP-mediated mitochondrial O2·− potentiates cytoplasmic O2·− by stimulation of NADPH oxidases. In this work we studied Nox isoforms as a potential target of mitochondrial O2·−. We tested contribution of reverse electron transfer (RET) from complex II to complex I in mitochondrial O2·− production and NADPH oxidase activation in human aortic endothelial cells. Activation of mitoKATP with low dose of diazoxide (100 nM) decreased mitochondrial membrane potential (tetramethylrhodamine methyl ester probe) and increased production of mitochondrial and cytoplasmic O2·− measured by site-specific probes and mitoSOX. Inhibition of RET with complex II inhibitor (malonate) or complex I inhibitor (rotenone) attenuated the production of mitochondrial and cytoplasmic O2·−. Supplementation with a mitochondria-targeted SOD mimetic (mitoTEMPO) or a mitochondria-targeted glutathione peroxidase mimetic (mitoEbselen) inhibited production of mitochondrial and cytoplasmic O2·−. Inhibition of Nox2 (gp91ds) or Nox2 depletion with small interfering RNA but not Nox1, Nox4, or Nox5 abolished diazoxide-induced O2·− production in the cytoplasm. Treatment of angiotensin II-infused mice with RET inhibitor dihydroethidium (malate) significantly reduced blood pressure. Our study suggests that mitoKATP-mediated mitochondrial O2·− stimulates cytoplasmic Nox2, contributing to the development of endothelial oxidative stress and hypertension. PMID:23955717

  17. Pathophysiology of mitochondrial lipid oxidation: Role of 4-hydroxynonenal (4-HNE) and other bioactive lipids in mitochondria.

    PubMed

    Xiao, Mengqing; Zhong, Huiqin; Xia, Lin; Tao, Yongzhen; Yin, Huiyong

    2017-10-01

    Mitochondrial lipids are essential for maintaining the integrity of mitochondrial membranes and the proper functions of mitochondria. As the "powerhouse" of a cell, mitochondria are also the major cellular source of reactive oxygen species (ROS). Oxidative stress occurs when the antioxidant system is overwhelmed by overproduction of ROS. Polyunsaturated fatty acids in mitochondrial membranes are primary targets for ROS attack, which may lead to lipid peroxidation (LPO) and generation of reactive lipids, such as 4-hydroxynonenal. When mitochondrial lipids are oxidized, the integrity and function of mitochondria may be compromised and this may eventually lead to mitochondrial dysfunction, which has been associated with many human diseases including cancer, cardiovascular diseases, diabetes, and neurodegenerative diseases. How mitochondrial lipids are oxidized and the underlying molecular mechanisms and pathophysiological consequences associated with mitochondrial LPO remain poorly defined. Oxidation of the mitochondria-specific phospholipid cardiolipin and generation of bioactive lipids through mitochondrial LPO has been increasingly recognized as an important event orchestrating apoptosis, metabolic reprogramming of energy production, mitophagy, and immune responses. In this review, we focus on the current understanding of how mitochondrial LPO and generation of bioactive lipid mediators in mitochondria are involved in the modulation of mitochondrial functions in the context of relevant human diseases associated with oxidative stress. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Oxidative folding in the mitochondrial intermembrane space in human health and disease.

    PubMed

    Fraga, Hugo; Ventura, Salvador

    2013-01-30

    Oxidative folding in the mitochondrial intermembrane space (IMS) is a key cellular event associated with the folding and import of a large and still undetermined number of proteins. This process is catalyzed by an oxidoreductase, Mia40 that is able to recognize substrates with apparently little or no homology. Following substrate oxidation, Mia40 is reduced and must be reoxidized by Erv1/Alr1 that consequently transfers the electrons to the mitochondrial respiratory chain. Although our understanding of the physiological relevance of this process is still limited, an increasing number of pathologies are being associated with the impairment of this pathway; especially because oxidative folding is fundamental for several of the proteins involved in defense against oxidative stress. Here we review these aspects and discuss recent findings suggesting that oxidative folding in the IMS is modulated by the redox state of the cell.

  19. Mitochondrial respiratory chain dysfunction variably increases oxidant stress in Caenorhabditis elegans.

    PubMed

    Dingley, Stephen; Polyak, Erzsebet; Lightfoot, Richard; Ostrovsky, Julian; Rao, Meera; Greco, Todd; Ischiropoulos, Harry; Falk, Marni J

    2010-03-01

    Mitochondrial dysfunction and associated oxidant stress have been linked with numerous complex diseases and aging largely by in vitro determination of mitochondria oxidant production and scavenging. We applied targeted in vivo fluorescence analyses of mitochondria-dense pharyngeal tissue in Caenorhabditis elegans to better understand relative mitochondrial effects, particularly on matrix oxidant burden, of respiratory chain complex, MnSOD, and insulin receptor mutants displaying variable longevity. The data demonstrate significantly elevated in vivo matrix oxidant burden in the short-lived complex I mutant, gas-1(fc21), which was associated with limited superoxide scavenging capacity despite robust MnSOD induction, as well as decreased mitochondria content and membrane potential. Significantly increased MnSOD activity was associated with in vivo matrix oxidant levels similar to wild-type in the long-lived respiratory chain complex III mutant, isp-1(qm150). Yet, despite greater superoxide scavenging capacity in the complex III mutant than in the significantly longer-lived insulin receptor mutant, daf-2(e1368), only the former showed modest oxidative stress sensitivity. Furthermore, increased longevity was seen in MnSOD knockout mutants (sod-2(ok1030) and sod-2(gk257)) that had decreased MnSOD scavenging capacity and increased in vivo matrix oxidant burden. Thus, factors beside oxidant stress must underlie RC mutant longevity in C. elegans. This work highlights the utility of the C. elegans model as a tractable means to non-invasively monitor multi-dimensional in vivo consequences of primary mitochondrial dysfunction.

  20. Proteomic analysis of pRb loss highlights a signature of decreased mitochondrial oxidative phosphorylation

    PubMed Central

    Nicolay, Brandon N.; Danielian, Paul S.; Kottakis, Filippos; Lapek, John D.; Sanidas, Ioannis; Miles, Wayne O.; Dehnad, Mantre; Tschöp, Katrin; Gierut, Jessica J.; Manning, Amity L.; Morris, Robert; Haigis, Kevin; Bardeesy, Nabeel; Lees, Jacqueline A.; Haas, Wilhelm; Dyson, Nicholas J.

    2015-01-01

    The retinoblastoma tumor suppressor (pRb) protein associates with chromatin and regulates gene expression. Numerous studies have identified Rb-dependent RNA signatures, but the proteomic effects of Rb loss are largely unexplored. We acutely ablated Rb in adult mice and conducted a quantitative analysis of RNA and proteomic changes in the colon and lungs, where RbKO was sufficient or insufficient to induce ectopic proliferation, respectively. As expected, RbKO caused similar increases in classic pRb/E2F-regulated transcripts in both tissues, but, unexpectedly, their protein products increased only in the colon, consistent with its increased proliferative index. Thus, these protein changes induced by Rb loss are coupled with proliferation but uncoupled from transcription. The proteomic changes in common between RbKO tissues showed a striking decrease in proteins with mitochondrial functions. Accordingly, RB1 inactivation in human cells decreased both mitochondrial mass and oxidative phosphorylation (OXPHOS) function. RBKO cells showed decreased mitochondrial respiratory capacity and the accumulation of hypopolarized mitochondria. Additionally, RB/Rb loss altered mitochondrial pyruvate oxidation from 13C-glucose through the TCA cycle in mouse tissues and cultured cells. Consequently, RBKO cells have an enhanced sensitivity to mitochondrial stress conditions. In summary, proteomic analyses provide a new perspective on Rb/RB1 mutation, highlighting the importance of pRb for mitochondrial function and suggesting vulnerabilities for treatment. PMID:26314710

  1. Centella asiatica Attenuates Mitochondrial Dysfunction and Oxidative Stress in Aβ-Exposed Hippocampal Neurons

    PubMed Central

    Zweig, Jonathan A.; Matthews, Donald G.; Caruso, Maya; Quinn, Joseph F.; Soumyanath, Amala

    2017-01-01

    Centella asiatica has been used for centuries to enhance memory. We have previously shown that a water extract of Centella asiatica (CAW) protects against the deleterious effects of amyloid-β (Aβ) in neuroblastoma cells and attenuates Aβ-induced cognitive deficits in mice. Yet, the neuroprotective mechanism of CAW has yet to be thoroughly explored in neurons from these animals. This study investigates the effects of CAW on neuronal metabolism and oxidative stress in isolated Aβ-expressing neurons. Hippocampal neurons from amyloid precursor protein overexpressing Tg2576 mice and wild-type (WT) littermates were treated with CAW. In both genotypes, CAW increased the expression of antioxidant response genes which attenuated the Aβ-induced elevations in reactive oxygen species (ROS) and lipid peroxidation in Tg2576 neurons. CAW also improved mitochondrial function in both genotypes and increased the expression of electron transport chain enzymes and mitochondrial labeling, suggesting an increase in mitochondrial content. These data show that CAW protects against mitochondrial dysfunction and oxidative stress in Aβ-exposed hippocampal neurons which could contribute to the beneficial effects of the extract observed in vivo. Since CAW also improved mitochondrial function in the absence of Aβ, these results suggest a broader utility for other conditions where neuronal mitochondrial dysfunction occurs. PMID:28883904

  2. Activation of mitochondrial oxidative phosphorylation during (+/-)-isoproterenol-induced cell injury of myocardium.

    PubMed

    Rendón, D A; López, L F

    2001-01-01

    Hydrolytic and synthetic activities of mitochondrial ATPase were studied during (+/-)-isoproterenol-induced cell injury of the myocardium (67 mg/kg body weight). This research was a long-term study (72 h) in which rat heart homogenates, and a potentiometric method were used. Hydrolytic activities in homogenates from (+/-)-isoproterenol-treated rats were not statistically different, during the whole long-term study, from the hydrolytic activity in normal homogenates. The synthetic activity (mitochondrial oxidative phosphorylation) of mitochondrial ATPase increased at 3, 6, and 18 h (35, 48 and 23% respectively) after (+/-)-isoproterenol administration with regard to the control group. At 12 h and 21-72 h after drug administration, the data revealed no differences between synthetic activity of mitochondrial ATPase in control vs (+/-)-isoproterenol treated homogenates. The facts that synthetic and hydrolytic activities in homogenates from (+/-)-isoproterenol treated rats were never lower than the synthetic and hydrolytic activities in normal homogenates, and that activation of mitochondrial oxidative phosphorylation occurred at some times after (+/-)-isoproterenol treatment, suggest that no considerable and "negative" modifications occur in the active configuration of mitochondrial ATPase during (+/-)-isoproterenol-induced injury of the myocardium (67 mg/kg body weight).

  3. Impaired cerebral mitochondrial oxidative phosphorylation function in a rat model of ventricular fibrillation and cardiopulmonary resuscitation.

    PubMed

    Jiang, Jun; Fang, Xiangshao; Fu, Yue; Xu, Wen; Jiang, Longyuan; Huang, Zitong

    2014-01-01

    Postcardiac arrest brain injury significantly contributes to mortality and morbidity in patients suffering from cardiac arrest (CA). Evidence that shows that mitochondrial dysfunction appears to be a key factor in tissue damage after ischemia/reperfusion is accumulating. However, limited data are available regarding the cerebral mitochondrial dysfunction during CA and cardiopulmonary resuscitation (CPR) and its relationship to the alterations of high-energy phosphate. Here, we sought to identify alterations of mitochondrial morphology and oxidative phosphorylation function as well as high-energy phosphates during CA and CPR in a rat model of ventricular fibrillation (VF). We found that impairment of mitochondrial respiration and partial depletion of adenosine triphosphate (ATP) and phosphocreatine (PCr) developed in the cerebral cortex and hippocampus following a prolonged cardiac arrest. Optimal CPR might ameliorate the deranged phosphorus metabolism and preserve mitochondrial function. No obvious ultrastructural abnormalities of mitochondria have been found during CA. We conclude that CA causes cerebral mitochondrial dysfunction along with decay of high-energy phosphates, which would be mitigated with CPR. This study may broaden our understanding of the pathogenic processes underlying global cerebral ischemic injury and provide a potential therapeutic strategy that aimed at preserving cerebral mitochondrial function during CA.

  4. Regulation of Skeletal Muscle Oxidative Capacity and Insulin Signaling by the Mitochondrial Rhomboid Protease PARL

    PubMed Central

    Civitarese, Anthony E.; MacLean, Paul S.; Carling, Stacy; Kerr-Bayles, Lyndal; McMillan, Ryan P.; Pierce, Anson; Becker, Thomas C.; Moro, Cedric; Finlayson, Jean; Lefort, Natalie; Newgard, Christopher B.; Mandarino, Lawrence; Cefalu, William; Walder, Ken; Collier, Greg R.; Hulver, Matthew W.; Smith, Steven R.; Ravussin, Eric

    2010-01-01

    SUMMARY Type 2 diabetes Mellitus (T2DM) and aging are characterized by insulin resistance, lower mitochondrial density and function and increased production of reactive oxygen species (ROS). In lower organisms continuous remodeling critically maintains the function and life cycle of mitochondria, in part by the protease pcp1 (PARL ortholog). We therefore examined whether variation in PARL protein content is associated with mitochondrial abnormalities and insulin resistance. Relative to healthy, young individuals (23±1y), PARL mRNA and mitochondrial mass were both reduced in elderly subjects (64.4±1.2 y; 51% and 44% respectively) and in subjects with T2DM (51.8±3 y; 31% and 41% respectively; all p<0.05). Muscle knock-down of PARL in mice resulted in lower mitochondrial content (−31±3%, p<0.05), lower OPA1 and PGC1α protein levels and impaired insulin signaling. Furthermore, mitochondrial cristae were malformed and resulted in elevated in vivo oxidative stress. Adenoviral suppression of PARL protein in healthy myotubes lowered mitochondrial mass (−33±8%), insulin stimulated glycogen synthesis (−33±9%) and increased ROS production (2-fold) (all p<0.05). We propose that lower PARL expression may contribute to the mitochondrial abnormalities seen in aging and T2DM. PMID:20444421

  5. Mitochondrial oxidative stress is the achille's heel of melanoma cells resistant to Braf-mutant inhibitor

    PubMed Central

    André, Fanny; Jonneaux, Aurélie; Scalbert, Camille; Garçon, Guillaume; Malet-Martino, Myriam; Balayssac, Stéphane; Rocchi, Stephane; Savina, Ariel; Formstecher, Pierre; Mortier, Laurent; Kluza, Jérome; Marchetti, Philippe

    2013-01-01

    Vemurafenib/PLX4032, a selective inhibitor of mutant BRAFV600E, constitutes a paradigm shift in melanoma therapy. Unfortunately, acquired resistance, which unavoidably occurs, represents one major limitation to clinical responses. Recent studies have highlighted that vemurafenib activated oxidative metabolism in BRAFV600E melanomas expressing PGC1α. However, the oxidative state of melanoma resistant to BRAF inhibitors is unknown. We established representative in vitro and in vivo models of human melanoma resistant to vemurafenib including primary specimens derived from melanoma patients. Firstly, our study reveals that vemurafenib increased mitochondrial respiration and ROS production in BRAFV600E melanoma cell lines regardless the expression of PGC1α. Secondly, melanoma cells that have acquired resistance to vemurafenib displayed intrinsically high rates of mitochondrial respiration associated with elevated mitochondrial oxidative stress irrespective of the presence of vemurafenib. Thirdly, the elevated ROS level rendered vemurafenib-resistant melanoma cells prone to cell death induced by pro-oxidants including the clinical trial drug, elesclomol. Based on these observations, we propose that the mitochondrial oxidative signature of resistant melanoma constitutes a novel opportunity to overcome resistance to BRAF inhibition. PMID:24161908

  6. Role of Mitochondrial Oxidants in an In Vitro Model of Sepsis-Induced Renal Injury

    PubMed Central

    Pathak, Elina; MacMillan-Crow, Lee Ann

    2012-01-01

    Oxidative stress has been implicated to play a major role in multiorgan dysfunction during sepsis. To study the mechanism of oxidant generation in acute kidney injury (AKI) during sepsis, we developed an in vitro model of sepsis using primary cultures of mouse cortical tubular epithelial cells exposed to serum (2.5–10%) collected from mice at 4 h after induction of sepsis by cecal ligation and puncture (CLP) or Sham (no sepsis). CLP serum produced a concentration-dependent increase in nitric oxide (NO) (nitrate + nitrite) release at 6 h and cytotoxicity (lactate dehydrogenase release) at 18 h compared with Sham serum treatment. Before cytotoxicity there was a decrease in mitochondrial membrane potential, which was followed by increased superoxide and peroxynitrite levels compared with Sham serum. The role of oxidants was evaluated by using the superoxide dismutase mimetic and peroxynitrite scavenger manganese(III)tetrakis(1-methyl-4-pyridyl)porphyrin tetratosylate hydroxide (MnTmPyP). MnTmPyP (10–100 μM) produced a concentration-dependent preservation of ATP and protection against cytotoxicity. MnTmPyP blocked mitochondrial superoxide and peroxynitrite generation produced by CLP serum but had no effect on NO levels. Although MnTmPyP did not block the initial CLP serum-induced fall in mitochondrial membrane potential, it allowed mitochondrial membrane potential to recover. Data from this in vitro model suggest a time-dependent generation of mitochondrial oxidants, mitochondrial dysfunction, and renal tubular epithelial cell injury and support the therapeutic potential of manganese porphyrin compounds in preventing sepsis-induced AKI. PMID:22011433

  7. Overexpression of PGC-1α Increases Peroxisomal and Mitochondrial Fatty Acid Oxidation in Human Primary Myotubes.

    PubMed

    Huang, Tai-Yu; Zheng, Donghai; Houmard, Joseph A; Brault, Jeffrey J; Hickner, Robert C; Cortright, Ronald N

    2017-01-10

    Peroxisomes are indispensable organelles for lipid metabolism in humans and their biogenesis has been assumed to be under regulation by peroxisome proliferator-activated receptors (PPARs). However, recent studies in hepatocytes suggest that the mitochondrial proliferator PGC-1α (peroxisome proliferator-activated receptor gamma coactivator-1 alpha) also acts as an upstream transcriptional regulator for enhancing peroxisomal abundance and associated activity. It is unknown whether the regulatory mechanism(s) for enhancing peroxisomal function is through the same node as mitochondrial biogenesis in human skeletal muscle (HSkM) and whether fatty acid oxidation (FAO) is affected. Primary myotubes from vastus lateralis biopsies from lean donors (BMI =24.0 ± 0.6 kg/m(2), N = 6) were exposed to adenovirus encoding human PGC-1α or GFP control. Peroxisomal biogenesis proteins (Peroxins) and genes (PEXs) responsible for proliferation and functions were assessed by western blotting and real-time qRT-PCR respectively. 1-(14)C palmitic acid and 1-(14)C lignoceric acid (exclusive peroxisomal specific substrate) were used to assess mitochondrial oxidation of peroxisomal derived metabolites. Following overexpression of PGC-1α, 1) Peroxisomal membrane protein 70kD (PMP70), PEX19, and mitochondrial citrate synthetase protein content were significantly elevated (P<0.05) 2) PGC-1α, PMP70, key PEXs, and peroxisomal β-oxidation mRNA expression levels were significantly upregulated (P<0.05) and 3) A concomitant increase in lignoceric acid oxidation by both peroxisomal and mitochondrial activity was observed (P<0.05). These novel findings demonstrate that, in addition to the proliferative effect on mitochondria, PGC-1α can induce peroxisomes and accompanying elevations in long-chain and very-long-chain fatty acid oxidation by a peroxisomal-mitochondrial functional cooperation as observed in HSkM cells.

  8. Resveratrol protects cardiomyocytes from oxidative stress through SIRT1 and mitochondrial biogenesis signaling pathways.

    PubMed

    Li, Yong-guang; Zhu, Wei; Tao, Jian-ping; Xin, Ping; Liu, Ming-ya; Li, Jing-bo; Wei, Meng

    2013-08-23

    Reactive oxygen species (ROS) is generated by oxidative stress and plays an important role in various cardiac pathologies. The SIRT1 signaling pathway and mitochondrial biogenesis play essential roles in mediating the production of ROS. SIRT1 activated by resveratrol protects cardiomyocytes from oxidative stress, but the exact mechanisms by which SIRT1 prevents oxidative stress, and its relationship with mitochondrial biogenesis, remain unclear. In this study, it was observed that after stimulation with 50μMH2O2 for 6h, H9C2 cells produced excessive ROS and downregulated SIRT1. The mitochondrial protein NDUFA13 was also downregulated by ROS mediated by SIRT1. Resveratrol induced the expression of SIRT1 and mitochondrial genes NDUFA1, NDUFA2, NDUFA13 and Mn-SOD. However, the production of these genes was reversed by SIRT1 inhibitor nicotinamide. These results suggest that resveratrol inhibits ROS generation in cardiomyocytes via SIRT1 and mitochondrial biogenesis signaling pathways. Copyright © 2013 Elsevier Inc. All rights reserved.

  9. Mitochondrial dysfunction, a probable cause of persistent oxidative stress after exposure to ionizing radiation.

    PubMed

    Yoshida, Takako; Goto, Shinji; Kawakatsu, Miho; Urata, Yoshishige; Li, Tao-Sheng

    2012-02-01

    Several recent studies have suggested that the reactive oxygen species (ROS) generated from mitochondria contribute to genomic instability after exposure of the cells to ionizing radiation, but the mechanism of this process is not yet fully understood. We examined the hypothesis that irradiation induces mitochondrial dysfunction to cause persistent oxidative stress, which contributes to genomic instability. After the exposure of cells to 5 Gy gamma-ray irradiation, we found that the irradiation induced the following changes in a clear pattern of time courses. First, a robust increase of intracellular ROS levels occurred within minutes, but the intracellular ROS disappeared within 30 min. Then the mitochondrial dysfunction was detected at 12 h after irradiation, as indicated by the decreased activity of NADH dehydrogenase (Complex I), the most important enzyme in regulating the release of ROS from the mitochondrial electron transport chain (ETC). Finally, a significant increase of ROS levels in the mitochondria and the oxidation of mitochondrial DNA were observed in cells at 24 h or later after irradiation. Although further experiments are required, results in this study support the hypothesis that mitochondrial dysfunction causes persistent oxidative stress that may contribute to promote radiation-induced genomic instability.

  10. Oxidative stress, mitochondrial dysfunction and, inflammation common events in skin of patients with Fibromyalgia.

    PubMed

    Sánchez-Domínguez, Benito; Bullón, Pedro; Román-Malo, Lourdes; Marín-Aguilar, Fabiola; Alcocer-Gómez, Elísabet; Carrión, Angel M; Sánchez-Alcazar, José Antonio; Cordero, Mario D

    2015-03-01

    Fibromyalgia is a chronic pain syndrome with unknown etiology. Recent studies have shown some evidence demonstrating that oxidative stress, mitochondrial dysfunction and inflammation may have a role in the pathophysiology of fibromyalgia. Despite several skin-related symptoms accompanied by small fiber neuropathy have been studied in FM, these mitochondrial changes have not been yet studied in this tissue. Skin biopsies from patients showed a significant mitochondrial dysfunction with reduced mitochondrial chain activities and bioenergetics levels and increased levels of oxidative stress. These data were related to increased levels of inflammation and correlated with pain, the principal symptom of FM. All these parameters have shown a role in peripheral nerve damage which has been observed in FM as a possible responsible to allodynia. Our findings may support the role of oxidative stress, mitochondrial dysfunction and inflammation as interdependent events in the pathophysiology of FM with a special role in the peripheral alterations. Copyright © 2015 Elsevier B.V. and Mitochondria Research Society. Published by Elsevier B.V. All rights reserved.

  11. Current Experience in Testing Mitochondrial Nutrients in Disorders Featuring Oxidative Stress and Mitochondrial Dysfunction: Rational Design of Chemoprevention Trials

    PubMed Central

    Pagano, Giovanni; Aiello Talamanca, Annarita; Castello, Giuseppe; Cordero, Mario D.; d’Ischia, Marco; Gadaleta, Maria Nicola; Pallardó, Federico V.; Petrović, Sandra; Tiano, Luca; Zatterale, Adriana

    2014-01-01

    An extensive number of pathologies are associated with mitochondrial dysfunction (MDF) and oxidative stress (OS). Thus, mitochondrial cofactors termed “mitochondrial nutrients” (MN), such as α-lipoic acid (ALA), Coenzyme Q10 (CoQ10), and l-carnitine (CARN) (or its derivatives) have been tested in a number of clinical trials, and this review is focused on the use of MN-based clinical trials. The papers reporting on MN-based clinical trials were retrieved in MedLine up to July 2014, and evaluated for the following endpoints: (a) treated diseases; (b) dosages, number of enrolled patients and duration of treatment; (c) trial success for each MN or MN combinations as reported by authors. The reports satisfying the above endpoints included total numbers of trials and frequencies of randomized, controlled studies, i.e., 81 trials testing ALA, 107 reports testing CoQ10, and 74 reports testing CARN, while only 7 reports were retrieved testing double MN associations, while no report was found testing a triple MN combination. A total of 28 reports tested MN associations with “classical” antioxidants, such as antioxidant nutrients or drugs. Combinations of MN showed better outcomes than individual MN, suggesting forthcoming clinical studies. The criteria in study design and monitoring MN-based clinical trials are discussed. PMID:25380523

  12. Chronic mitochondrial uncoupling treatment prevents acute cold-induced oxidative stress in birds.

    PubMed

    Stier, Antoine; Massemin, Sylvie; Criscuolo, François

    2014-12-01

    Endotherms have evolved two major types of thermogenesis that allow them to actively produce heat in response to cold exposure, either through muscular activity (i.e. shivering thermogenesis) or through futile electro-chemical cycles (i.e. non-shivering thermogenesis). Amongst the latter, mitochondrial uncoupling is of key importance because it is suggested to drive heat production at a low cost in terms of oxidative stress. While this has been experimentally shown in mammals, the oxidative stress consequences of cold exposure and mitochondrial uncoupling are clearly less understood in the other class of endotherms, the birds. We compared metabolic and oxidative stress responses of zebra finches chronically treated with or without a chemical mitochondrial uncoupler (2,4-dinitrophenol: DNP), undergoing an acute (24 h) and a chronic (4 weeks) cold exposure (12 °C). We predicted that control birds should present at least a transient elevation of oxidative stress levels in response to cold exposure. This oxidative stress cost should be more pronounced in control birds than in DNP-treated birds, due to their lower basal uncoupling state. Despite similar increase in metabolism, control birds presented elevated levels of DNA oxidative damage in response to acute (but not chronic) cold exposure, while DNP-treated birds did not. Plasma antioxidant capacity decreased overall in response to chronic cold exposure. These results show that acute cold exposure increases oxidative stress in birds. However, uncoupling mitochondrial functioning appears as a putative compensatory mechanism preventing cold-induced oxidative stress. This result confirms previous observations in mice and underlines non-shivering thermogenesis as a putative key mechanism for endotherms in mounting a response to cold at a low oxidative cost.

  13. SIRT1 activation by curcumin pretreatment attenuates mitochondrial oxidative damage induced by myocardial ischemia reperfusion injury.

    PubMed

    Yang, Yang; Duan, Weixun; Lin, Yan; Yi, Wei; Liang, Zhenxing; Yan, Juanjuan; Wang, Ning; Deng, Chao; Zhang, Song; Li, Yue; Chen, Wensheng; Yu, Shiqiang; Yi, Dinghua; Jin, Zhenxiao

    2013-12-01

    Ischemia reperfusion (IR) injury (IRI) is harmful to the cardiovascular system and causes mitochondrial oxidative stress. Silent information regulator 1 (SIRT1), a type of histone deacetylase, contributes to IRI. Curcumin (Cur) is a strong natural antioxidant and is the active component in Curcuma longa; Cur has protective effects against IRI and may regulate the activity of SIRT1. This study was designed to investigate the protective effect of Cur pretreatment on myocardial IRI and to elucidate this potential mechanism. Isolated and in vivo rat hearts and cultured neonatal rat cardiomyocytes were subjected to IR. Prior to this procedure, the hearts or cardiomyocytes were exposed to Cur in the absence or presence of the SIRT1 inhibitor sirtinol or SIRT1 siRNA. Cur conferred a cardioprotective effect, as shown by improved postischemic cardiac function, decreased myocardial infarct size, decreased myocardial apoptotic index, and several biochemical parameters, including the up-regulation of the antiapoptotic protein Bcl2 and the down-regulation of the proapoptotic protein Bax. Sirtinol and SIRT1 siRNA each blocked the Cur-mediated cardioprotection by inhibiting SIRT1 signaling. Cur also resulted in a well-preserved mitochondrial redox potential, significantly elevated mitochondrial superoxide dismutase activity, and decreased formation of mitochondrial hydrogen peroxide and malondialdehyde. These observations indicated that the IR-induced mitochondrial oxidative damage was remarkably attenuated. However, this Cur-elevated mitochondrial function was reversed by sirtinol or SIRT1 siRNA treatment. In summary, our results demonstrate that Cur pretreatment attenuates IRI by reducing IR-induced mitochondrial oxidative damage through the activation of SIRT1 signaling.

  14. Glucocorticoids Suppress Mitochondrial Oxidant Production via Upregulation of Uncoupling Protein 2 in Hyperglycemic Endothelial Cells

    PubMed Central

    Szabo, Csaba

    2016-01-01

    Diabetic complications are the leading cause of morbidity and mortality in diabetic patients. Elevated blood glucose contributes to the development of endothelial and vascular dysfunction, and, consequently, to diabetic micro- and macrovascular complications, because it increases the mitochondrial proton gradient and mitochondrial oxidant production. Therapeutic approaches designed to counteract glucose-induced mitochondrial reactive oxygen species (ROS) production in the vasculature are expected to show efficacy against all diabetic complications, but direct pharmacological targeting (scavenging) of mitochondrial oxidants remains challenging due to the high reactivity of some of these oxidant species. In a recent study, we have conducted a medium-throughput cell-based screening of a focused library of well-annotated pharmacologically active compounds and identified glucocorticoids as inhibitors of mitochondrial superoxide production in microvascular endothelial cells exposed to elevated extracellular glucose. The goal of the current study was to investigate the mechanism of glucocorticoids' action. Our findings show that glucocorticoids induce the expression of the mitochondrial UCP2 protein and decrease the mitochondrial potential. UCP2 silencing prevents the protective effect of the glucocorticoids on ROS production. UCP2 induction also increases the oxygen consumption and the “proton leak” in microvascular endothelial cells. Furthermore, glutamine supplementation augments the effect of glucocorticoids via further enhancing the expression of UCP2 at the translational level. We conclude that UCP2 induction represents a novel experimental therapeutic intervention in diabetic vascular complications. While direct repurposing of glucocorticoids may not be possible for the therapy of diabetic complications due to their significant side effects that develop during chronic administration, the UCP2 pathway may be therapeutically targetable by other, glucocorticoid

  15. N-Acetyl-L-cysteine Protects the Enterocyte against Oxidative Damage by Modulation of Mitochondrial Function

    PubMed Central

    Xiao, Hao; Wu, Miaomiao; Shao, Fangyuan; Guan, Guiping; Huang, Bo

    2016-01-01

    The neonatal small intestine is susceptible to damage caused by oxidative stress. This study aimed to evaluate the protective role of antioxidant N-acetylcysteine (NAC) in intestinal epithelial cells against oxidative damage induced by H2O2. IPEC-J2 cells were cultured in DMEM-H with NAC and H2O2. After 2-day incubation, IPEC-J2 cells were collected for analysis of DNA synthesis, antioxidation capacity, mitochondrial respiration, and cell apoptosis. The results showed that H2O2 significantly decreased (P < 0.05) proliferation rate, mitochondrial respiration, and antioxidation capacity and increased cell apoptosis and the abundance of associated proteins, including cytochrome C, Bcl-XL, cleaved caspase-3, and total caspase-3. NAC supplementation remarkably increased (P < 0.05) proliferation rate, antioxidation capacity, and mitochondrial bioenergetics but decreased cell apoptosis. These findings indicate that NAC might rescue the intestinal injury induced by H2O2. PMID:28003713

  16. Link between cancer and Alzheimer disease via oxidative stress induced by nitric oxide-dependent mitochondrial DNA overproliferation and deletion.

    PubMed

    Aliev, Gjumrakch; Obrenovich, Mark E; Tabrez, Shams; Jabir, Nasimudeen R; Reddy, V Prakash; Li, Yi; Burnstock, Geoffrey; Cacabelos, Ramon; Kamal, Mohammad Amjad

    2013-01-01

    Nitric oxide- (NO-) dependent oxidative stress results in mitochondrial ultrastructural alterations and DNA damage in cases of Alzheimer disease (AD). However, little is known about these pathways in human cancers, especially during the development as well as the progression of primary brain tumors and metastatic colorectal cancer. One of the key features of tumors is the deficiency in tissue energy that accompanies mitochondrial lesions and formation of the hypoxic smaller sized mitochondria with ultrastructural abnormalities. We speculate that mitochondrial involvement may play a significant role in the etiopathogenesis of cancer. Recent studies also demonstrate a potential link between AD and cancer, and anticancer drugs are being explored for the inhibition of AD-like pathology in transgenic mice. Severity of the cancer growth, metastasis, and brain pathology in AD (in animal models that mimic human AD) correlate with the degree of mitochondrial ultrastructural abnormalities. Recent advances in the cell-cycle reentry of the terminally differentiated neuronal cells indicate that NO-dependent mitochondrial abnormal activities and mitotic cell division are not the only important pathogenic factors in pathogenesis of cancer and AD, but open a new window for the development of novel treatment strategies for these devastating diseases.

  17. Oxidative stress and mitochondrial dysfunction in atherosclerosis: mitochondria-targeted antioxidants as potential therapy.

    PubMed

    Victor, V M; Apostolova, N; Herance, R; Hernandez-Mijares, A; Rocha, M

    2009-01-01

    Chronic and acute overproduction of reactive oxygen species (ROS) under pathophysiologic conditions forms an integral part of the development of cardiovascular diseases (CVD), and in particular atherosclerosis. These ROS are released from different sources, such as xanthine oxidase, lipoxygenase, nicotinamide adenine dinucleotide phosphate oxidase, the uncoupling of nitric oxide synthase and, in particular, mitochondria. Endothelial dysfunction, characterized by a loss of nitric oxide (NO) bioactivity, occurs early on in the development of atherosclerosis, and determines future vascular complications. Although the molecular mechanisms responsible for mitochondria-mediated disease processes are not clear, oxidative stress seems to play an important role. In general, ROS are essential to cell function, but adequate levels of antioxidant defenses are required in order to avoid the harmful effects of excessive ROS production. Mitochondrial oxidative stress damage and dysfunction contribute to a number of cell pathologies that manifest themselves through a range of conditions. This review considers the process of atherosclerosis from a mitochondrial perspective, and assesses strategies for the targeted delivery of antioxidants to mitochondria that are currently under development. We will provide a summary of the following areas: the cellular metabolism of reactive oxygen species (ROS) and its role in pathophysiological processes such as atherosclerosis; currently available antioxidants and possible reasons for their efficacy and inefficacy in ameliorating oxidative stress-mediated diseases; and recent developments in mitochondrially-targeted antioxidants that concentrate on the matrix-facing surface of the inner mitochondrial membrane in order to protect against mitochondrial oxidative damage, and their therapeutic potential as a treatment for atherosclerosis.

  18. Oxidation of alpha-ketoglutarate is required for reductive carboxylation in cancer cells with mitochondrial defects

    PubMed Central

    Mullen, Andrew R.; Hu, Zeping; Shi, Xiaolei; Jiang, Lei; Boroughs, Lindsey K.; Kovacs, Zoltan; Boriack, Richard; Rakheja, Dinesh; Sullivan, Lucas B.; Linehan, W. Marston; Chandel, Navdeep S.; DeBerardinis, Ralph J.

    2014-01-01

    Summary Mammalian cells generate citrate by decarboxylating pyruvate in the mitochondria to supply the tricarboxylic acid (TCA) cycle. In contrast, hypoxia and other impairments of mitochondrial function induce an alternative pathway that produces citrate by reductively carboxylating α-ketoglutarate (AKG) via NADPH-dependent isocitrate dehydrogenase (IDH). It is unknown how cells generate reducing equivalents necessary to supply reductive carboxylation in the setting of mitochondrial impairment. Here we identified shared metabolic features in cells using reductive carboxylation. Paradoxically, reductive carboxylation was accompanied by concomitant AKG oxidation in the TCA cycle. Inhibiting AKG oxidation decreased reducing equivalent availability and suppressed reductive carboxylation. Interrupting transfer of reducing equivalents from NADH to NADPH by nicotinamide nucleotide transhydrogenase increased NADH abundance and decreased NADPH abundance while suppressing reductive carboxylation. The data demonstrate that reductive carboxylation requires bidirectional AKG metabolism along oxidative and reductive pathways, with the oxidative pathway producing reducing equivalents used to operate IDH in reverse. PMID:24857658

  19. Exenatide improves liver mitochondrial dysfunction and insulin resistance by reducing oxidative stress in high fat diet-induced obese mice.

    PubMed

    Wang, Zixuan; Hou, Lin; Huang, Lanhui; Guo, Jun; Zhou, Xinli

    2017-04-22

    Oxidative stress is associated with obesity and may be accompanied by liver insulin resistance and mitochondrial dysfunction. Decreased mitochondrial respiratory chain enzymatic activities and decreased insulin metabolic signaling may promote these maladaptive changes. In this context, exenatide has been reported to reduce hepatic lipid deposition, improve insulin sensitivity and improve mitochondrial dysfunction. We hypothesized that exenatide would attenuate mitochondrial dysfunction by reducing hepatic lipid deposition, blunting oxidant stress and promoting insulin metabolic signaling in a high fat diet-induced model of obesity and insulin resistance. Sixteen-week-old male C57BL/6 diet-induced obese (DIO) mices and age-matched standard diet (STD) mices were treated with exenatide (10 μg/kg twice a day) for 28 days. Compared with untreated STD mice, untreated DIO mice exhibited deposited excessive lipid in liver and produced the oxidative stress in conjunction with insulin resistance, abnormal hepatic cells and mitochondrial histoarchitecture, mitochondrial dysfunction and reduced organism metabolism. Exenatide reduced hepatic steatosis, decreased oxidative stress, and improved insulin resistance in DIO mice, in concert with improvements in the insulin metabolic signaling, mitochondrial respiratory chain enzymatic activation, adenine nucleotide production, organism metabolism and weight gain. Results support the hypothesis that exenatide reduces hepatic cells and mitochondrial structural anomaly and improves insulin resistance in concert with improvements in insulin sensitivity and mitochondrial function activation, concomitantly with reductions in oxidative stress.

  20. Tissue variation of mitochondrial oxidative phosphorylation efficiency in cold-acclimated ducklings.

    PubMed

    Salin, Karine; Teulier, Loïc; Rey, Benjamin; Rouanet, Jean-Louis; Voituron, Yann; Duchamp, Claude; Roussel, Damien

    2010-01-01

    We investigated the oxidative phosphorylation efficiency of liver and gastrocnemius muscle mitochondria in thermoneutral and cold-acclimated ducklings. The yield of oxidative phosphorylation was lower in muscle than in liver mitochondria, a difference that was associated with a higher proton conductance in muscle mitochondria. Cold exposure did not affect oxidative phosphorylation efficiency or basal proton leak in mitochondria. We conclude that the basal proton conductance of mitochondria may regulate mitochondrial oxidative phosphorylation efficiency, but is not an important contributor to thermogenic processes in cold-acclimated ducklings.

  1. The spectrum of pyruvate oxidation defects in the diagnosis of mitochondrial disorders.

    PubMed

    Sperl, Wolfgang; Fleuren, Leanne; Freisinger, Peter; Haack, Tobias B; Ribes, Antonia; Feichtinger, René G; Rodenburg, Richard J; Zimmermann, Franz A; Koch, Johannes; Rivera, Isabel; Prokisch, Holger; Smeitink, Jan A; Mayr, Johannes A

    2015-05-01

    Pyruvate oxidation defects (PODs) are among the most frequent causes of deficiencies in the mitochondrial energy metabolism and represent a substantial subset of classical mitochondrial diseases. PODs are not only caused by deficiency of subunits of the pyruvate dehydrogenase complex (PDHC) but also by various disorders recently described in the whole pyruvate oxidation route including cofactors, regulation of PDHC and the mitochondrial pyruvate carrier. Our own patients from 2000 to July 2014 and patients identified by a systematic survey of the literature from 1970 to July 2014 with a pyruvate oxidation disorder and a genetically proven defect were included in the study (n=628). Of these defects 74.2% (n=466) belong to PDHC subunits, 24.5% (n=154) to cofactors, 0.5% (n=3) to PDHC regulation and 0.8% (n=5) to mitochondrial pyruvate import. PODs are underestimated in the field of mitochondrial diseases because not all diagnostic centres include biochemical investigations of PDHC in their routine analysis. Cofactor and transport defects can be missed, if pyruvate oxidation is not measured in intact mitochondria routinely. Furthermore deficiency of the X-chromosomal PDHA1 can be biochemically missed depending on the X-inactivation pattern. This is reflected by an increasing number of patients diagnosed recently by genetic high throughput screening approaches. PDHC deficiency including regulation and import affect mainly the glucose dependent central and peripheral nervous system and skeletal muscle. PODs with combined enzyme defects affect also other organs like heart, lung and liver. The spectrum of clinical presentation of PODs is still expanding. PODs are a therapeutically interesting group of mitochondrial diseases since some can be bypassed by ketogenic diet or treated by cofactor supplementation. PDHC kinase inhibition, chaperone therapy and PGC1α stimulation is still a matter of further investigations.

  2. Post-translational oxidative modification and inactivation of mitochondrial complex I in epileptogenesis.

    PubMed

    Ryan, Kristen; Backos, Donald S; Reigan, Philip; Patel, Manisha

    2012-08-15

    Mitochondrial oxidative stress and damage have been implicated in the etiology of temporal lobe epilepsy, but whether or not they have a functional impact on mitochondrial processes during epilepsy development (epileptogenesis) is unknown. One consequence of increased steady-state mitochondrial reactive oxygen species levels is protein post-translational modification (PTM). We hypothesize that complex I (CI), a protein complex of the mitochondrial electron transport chain, is a target for oxidant-induced PTMs, such as carbonylation, leading to impaired function during epileptogenesis. The goal of this study was to determine whether oxidative modifications occur and what impact they have on CI enzymatic activity in the rat hippocampus in response to kainate (KA)-induced epileptogenesis. Rats were injected with a single high dose of KA or vehicle and evidence for CI modifications was measured during the acute, latent, and chronic stages of epilepsy. Mitochondrial-specific carbonylation was increased acutely (48 h) and chronically (6 week), coincident with decreased CI activity. Mass spectrometry analysis of immunocaptured CI identified specific metal catalyzed carbonylation to Arg76 within the 75 kDa subunit concomitant with inhibition of CI activity during epileptogenesis. Computational-based molecular modeling studies revealed that Arg76 is in close proximity to the active site of CI and carbonylation of the residue is predicted to induce substantial structural alterations to the protein complex. These data provide evidence for the occurrence of a specific and irreversible oxidative modification of an important mitochondrial enzyme complex critical for cellular bioenergetics during the process of epileptogenesis.

  3. Coenzyme Q10 ameliorates oxidative stress and prevents mitochondrial alteration in ischemic retinal injury.

    PubMed

    Lee, Dongwook; Kim, Keun-Young; Shim, Myoung Sup; Kim, Sang Yeop; Ellisman, Mark H; Weinreb, Robert N; Ju, Won-Kyu

    2014-04-01

    Coenzyme Q10 (CoQ10) acts by scavenging reactive oxygen species for protecting neuronal cells against oxidative stress in neurodegenerative diseases. We tested whether a diet supplemented with CoQ10 ameliorates oxidative stress and mitochondrial alteration, as well as promotes retinal ganglion cell (RGC) survival in ischemic retina induced by intraocular pressure elevation. A CoQ10 significantly promoted RGC survival at 2 weeks after ischemia. Superoxide dismutase 2 (SOD2) and heme oxygenase-1 (HO-1) expression were significantly increased at 12 h after ischemic injury. In contrast, the CoQ10 significantly prevented the upregulation of SOD2 and HO-1 protein expression in ischemic retina. In addition, the CoQ10 significantly blocked activation of astroglial and microglial cells in ischemic retina. Interestingly, the CoQ10 blocked apoptosis by decreasing caspase-3 protein expression in ischemic retina. Bax and phosphorylated Bad (pBad) protein expression were significantly increased in ischemic retina at 12 h. Interestingly, while CoQ10 significantly decreased Bax protein expression in ischemic retina, CoQ10 showed greater increase of pBad protein expression. Of interest, ischemic injury significantly increased mitochondrial transcription factor A (Tfam) protein expression in the retina at 12 h, however, CoQ10 significantly preserved Tfam protein expression in ischemic retina. Interestingly, there were no differences in mitochondrial DNA content among control- or CoQ10-treated groups. Our findings demonstrate that CoQ10 protects RGCs against oxidative stress by modulating the Bax/Bad-mediated mitochondrial apoptotic pathway as well as prevents mitochondrial alteration by preserving Tfam protein expression in ischemic retina. Our results suggest that CoQ10 may provide neuroprotection against oxidative stress-mediated mitochondrial alterations in ischemic retinal injury.

  4. Induction of Mitochondrial Dysfunction and Oxidative Stress in Leishmania donovani by Orally Active Clerodane Diterpene

    PubMed Central

    Kathuria, Manoj; Bhattacharjee, Arindam; Sashidhara, Koneni V.; Singh, Suriya Pratap

    2014-01-01

    This study was performed to investigate the mechanistic aspects of cell death induced by a clerodane diterpene (K-09) in Leishmania donovani promastigotes that was previously demonstrated to be safe and orally active against visceral leishmaniasis (VL). K-09 caused depolarization of the mitochondrion and the generation of reactive oxygen species, triggering an apoptotic response in L. donovani promastigotes. Mitochondrial dysfunction subsequently resulted in the release of cytochrome c into the cytosol, impairing ATP production. Oxidative stress caused the depletion of reduced glutathione, while pretreatment with antioxidant N-acetyl cysteine (NAC) was able to abrogate oxidative stress. However, NAC failed to restore the mitochondrial membrane potential or intracellular calcium homeostasis after K-09 treatment, suggesting that the generation of oxidative stress is a downstream event relative to the other events. Caspase-3/-7-like protease activity and genomic DNA fragmentation were observed. Electron microscopy studies revealed gross morphological alterations typical of apoptosis, including severe mitochondrial damage, pyknosis of the nucleus, structural disruption of the mitochondrion-kinetoplast complex, flagellar pocket alterations, and the displacement of organelles. Moreover, an increased number of lipid droplets was detected after K-09 treatment, which is suggestive of altered lipid metabolism. Our results indicate that K-09 induces mitochondrial dysfunction and oxidative stress-mediated apoptotic cell death in L. donovani promastigotes, sharing many features with metazoan apoptosis. These mechanistic insights provide a basis for further investigation toward the development of K-09 as a potential drug candidate for VL. PMID:25070112

  5. Mitochondrial defects and oxidative stress in Alzheimer disease and Parkinson disease

    PubMed Central

    Yan, Michael H.; Wang, Xinglong; Zhu, Xiongwei

    2013-01-01

    Alzheimer disease (AD) and Parkinson disease (PD) are the two most common age-related neurodegenerative diseases characterized by prominent neurodegeneration in selective neural systems. Although a small fraction of AD and PD cases exhibit evidence of heritability, among which many genes have been identified, the majority are sporadic without known causes. Molecular mechanisms underlying neurodegeneration and pathogenesis of these diseases remain elusive. Convincing evidence demonstrates oxidative stress as a prominent feature in AD and PD and links oxidative stress to the development of neuronal death and neural dysfunction, which suggests a key pathogenic role for oxidative stress in both AD and PD. Notably, mitochondrial dysfunction is also a prominent feature in these diseases, which is likely to be of critical importance in the genesis and amplification of reactive oxygen species and the pathophysiology of these diseases. In this review, we focus on changes in mitochondrial DNA and mitochondrial dynamics, two aspects critical to the maintenance of mitochondrial homeostasis and function, in relationship with oxidative stress in the pathogenesis of AD and PD. PMID:23200807

  6. Centella asiatica Attenuates D-Galactose-Induced Cognitive Impairment, Oxidative and Mitochondrial Dysfunction in Mice.

    PubMed

    Kumar, Anil; Prakash, Atish; Dogra, Samrita

    2011-01-01

    D-galactose induced neurotoxicity is well known model for studying aging and related oxidative damage and memory impairment. Aging is a biological process, characterized by the gradual loss of physiological functions by unknown mechanism. Centella asiatica, Indian pennywort has been documented in the treatment of various neurological disorders including aging. Therefore, present study has been conducted in order to explore the possible role of Centella asiatica against D-galactose induced cognitive impairment, oxidative and mitochondrial dysfunction in mice. Chronic administration of D-galactose (100 mg/kg s.c.) for a period of six weeks significantly impaired cognitive task (both in both Morris water maze and elevated plus maze) and oxidative defense (Increased lipid peroxidation, nitrite concentration and decreased activity of superoxide dismutase, catalase and non-protein thiols) and impaired mitochondrial complex (I, II and III) enzymes activities as compared to sham group. Six weeks Centella asiatica (150 and 300 mg/kg, p.o) treatment significantly improved behavioral alterations, oxidative damage and mitochondrial enzyme complex activities as compared to contro l (D-galactose). Centella asiatica also attenuated enhanced acetylcholine esterase enzyme level in D-galactose senescence mice. Present study highlights the protective effect of Centella asiatica against D-galactose induced behavioral, biochemical and mitochondrial dysfunction in mice.

  7. Induction of mitochondrial dysfunction and oxidative stress in Leishmania donovani by orally active clerodane diterpene.

    PubMed

    Kathuria, Manoj; Bhattacharjee, Arindam; Sashidhara, Koneni V; Singh, Suriya Pratap; Mitra, Kalyan

    2014-10-01

    This study was performed to investigate the mechanistic aspects of cell death induced by a clerodane diterpene (K-09) in Leishmania donovani promastigotes that was previously demonstrated to be safe and orally active against visceral leishmaniasis (VL). K-09 caused depolarization of the mitochondrion and the generation of reactive oxygen species, triggering an apoptotic response in L. donovani promastigotes. Mitochondrial dysfunction subsequently resulted in the release of cytochrome c into the cytosol, impairing ATP production. Oxidative stress caused the depletion of reduced glutathione, while pretreatment with antioxidant N-acetyl cysteine (NAC) was able to abrogate oxidative stress. However, NAC failed to restore the mitochondrial membrane potential or intracellular calcium homeostasis after K-09 treatment, suggesting that the generation of oxidative stress is a downstream event relative to the other events. Caspase-3/-7-like protease activity and genomic DNA fragmentation were observed. Electron microscopy studies revealed gross morphological alterations typical of apoptosis, including severe mitochondrial damage, pyknosis of the nucleus, structural disruption of the mitochondrion-kinetoplast complex, flagellar pocket alterations, and the displacement of organelles. Moreover, an increased number of lipid droplets was detected after K-09 treatment, which is suggestive of altered lipid metabolism. Our results indicate that K-09 induces mitochondrial dysfunction and oxidative stress-mediated apoptotic cell death in L. donovani promastigotes, sharing many features with metazoan apoptosis. These mechanistic insights provide a basis for further investigation toward the development of K-09 as a potential drug candidate for VL.

  8. Mitochondrial defects and oxidative stress in Alzheimer disease and Parkinson disease.

    PubMed

    Yan, Michael H; Wang, Xinglong; Zhu, Xiongwei

    2013-09-01

    Alzheimer disease (AD) and Parkinson disease (PD) are the two most common age-related neurodegenerative diseases characterized by prominent neurodegeneration in selective neural systems. Although a small fraction of AD and PD cases exhibit evidence of heritability, among which many genes have been identified, the majority are sporadic without known causes. Molecular mechanisms underlying neurodegeneration and pathogenesis of these diseases remain elusive. Convincing evidence demonstrates oxidative stress as a prominent feature in AD and PD and links oxidative stress to the development of neuronal death and neural dysfunction, which suggests a key pathogenic role for oxidative stress in both AD and PD. Notably, mitochondrial dysfunction is also a prominent feature in these diseases, which is likely to be of critical importance in the genesis and amplification of reactive oxygen species and the pathophysiology of these diseases. In this review, we focus on changes in mitochondrial DNA and mitochondrial dynamics, two aspects critical to the maintenance of mitochondrial homeostasis and function, in relationship with oxidative stress in the pathogenesis of AD and PD.

  9. Suppression of oxidative metabolism and mitochondrial biogenesis by the transcriptional corepressor RIP140 in mouse adipocytes

    PubMed Central

    Powelka, Aimee M.; Seth, Asha; Virbasius, Joseph V.; Kiskinis, Evangelos; Nicoloro, Sarah M.; Guilherme, Adilson; Tang, Xiaoqing; Straubhaar, Juerg; Cherniack, Andrew D.; Parker, Malcolm G.; Czech, Michael P.

    2005-01-01

    Using an siRNA-based screen, we identified the transcriptional corepressor RIP140 as a negative regulator of insulin-responsive hexose uptake and oxidative metabolism in 3T3-L1 adipocytes. Affymetrix GeneChip profiling revealed that RIP140 depletion upregulates the expression of clusters of genes in the pathways of glucose uptake, glycolysis, TCA cycle, fatty acid oxidation, mitochondrial biogenesis, and oxidative phosphorylation in these cells. Conversely, we show that reexpression of RIP140 in mouse embryonic fibroblasts derived from RIP140-null mice downregulates expression of many of these same genes. Consistent with these microarray data, RIP140 gene silencing in cultured adipocytes increased both conversion of [14C]glucose to CO2 and mitochondrial oxygen consumption. RIP140-null mice, previously reported to resist weight gain on a high-fat diet, are shown here to display enhanced glucose tolerance and enhanced responsiveness to insulin compared with matched wild-type mice upon high-fat feeding. Mechanistically, RIP140 was found to require the nuclear receptor ERRα to regulate hexose uptake and mitochondrial proteins SDHB and CoxVb, although it likely acts through other nuclear receptors as well. We conclude that RIP140 is a major suppressor of adipocyte oxidative metabolism and mitochondrial biogenesis, as well as a negative regulator of whole-body glucose tolerance and energy expenditure in mice. PMID:16374519

  10. Centella asiatica Attenuates D-Galactose-Induced Cognitive Impairment, Oxidative and Mitochondrial Dysfunction in Mice

    PubMed Central

    Kumar, Anil; Prakash, Atish; Dogra, Samrita

    2011-01-01

    D-galactose induced neurotoxicity is well known model for studying aging and related oxidative damage and memory impairment. Aging is a biological process, characterized by the gradual loss of physiological functions by unknown mechanism. Centella asiatica, Indian pennywort has been documented in the treatment of various neurological disorders including aging. Therefore, present study has been conducted in order to explore the possible role of Centella asiatica against D-galactose induced cognitive impairment, oxidative and mitochondrial dysfunction in mice. Chronic administration of D-galactose (100 mg/kg s.c.) for a period of six weeks significantly impaired cognitive task (both in both Morris water maze and elevated plus maze) and oxidative defense (Increased lipid peroxidation, nitrite concentration and decreased activity of superoxide dismutase, catalase and non-protein thiols) and impaired mitochondrial complex (I, II and III) enzymes activities as compared to sham group. Six weeks Centella asiatica (150 and 300 mg/kg, p.o) treatment significantly improved behavioral alterations, oxidative damage and mitochondrial enzyme complex activities as compared to contro l (D-galactose). Centella asiatica also attenuated enhanced acetylcholine esterase enzyme level in D-galactose senescence mice. Present study highlights the protective effect of Centella asiatica against D-galactose induced behavioral, biochemical and mitochondrial dysfunction in mice. PMID:21629743

  11. Mitophagy is triggered by mild oxidative stress in a mitochondrial fission dependent manner.

    PubMed

    Frank, Magdalena; Duvezin-Caubet, Stéphane; Koob, Sebastian; Occhipinti, Angelo; Jagasia, Ravi; Petcherski, Anton; Ruonala, Mika O; Priault, Muriel; Salin, Bénédicte; Reichert, Andreas S

    2012-12-01

    Mitochondrial dysfunction is linked to apoptosis, aging, cancer, and a number of neurodegenerative and muscular disorders. The interplay between mitophagy and mitochondrial dynamics has been linked to the removal of dysfunctional mitochondria ensuring mitochondrial quality control. An open question is what role mitochondrial fission plays in the removal of mitochondria after mild and transient oxidative stress; conditions reported to result in moderately elevated reactive oxygen species (ROS) levels comparable to physical activity. Here we show that applying such conditions led to fragmentation of mitochondria and induction of mitophagy in mouse and human cells. These conditions increased ROS levels only slightly and neither triggered cell death nor led to a detectable induction of non-selective autophagy. Starvation led to hyperfusion of mitochondria, to high ROS levels, and to the induction of both non-selective autophagy and to a lesser extent to mitophagy. We conclude that moderate levels of ROS specifically trigger mitophagy but are insufficient to trigger non-selective autophagy. Expression of a dominant-negative variant of the fission factor DRP1 blocked mitophagy induction by mild oxidative stress as well as by starvation. Taken together, we demonstrate that in mammalian cells under mild oxidative stress a DRP1-dependent type of mitophagy is triggered while a concomitant induction of non-selective autophagy was not observed. We propose that these mild oxidative conditions resembling well physiological situations are thus very helpful for studying the molecular pathways governing the selective removal of dysfunctional mitochondria.

  12. Screening SIRT1 Activators from Medicinal Plants as Bioactive Compounds against Oxidative Damage in Mitochondrial Function

    PubMed Central

    Wang, Yi; Liang, Xinying; Chen, Yaqi; Zhao, Xiaoping

    2016-01-01

    Sirtuin type 1 (SIRT1) belongs to the family of NAD+ dependent histone deacetylases and plays a critical role in cellular metabolism and response to oxidative stress. Traditional Chinese medicines (TCMs), as an important part of natural products, have been reported to exert protective effect against oxidative stress in mitochondria. In this study, we screened SIRT1 activators from TCMs and investigated their activities against mitochondrial damage. 19 activators were found in total by in vitro SIRT1 activity assay. Among those active compounds, four compounds, ginsenoside Rb2, ginsenoside F1, ginsenoside Rc, and schisandrin A, were further studied to validate the SIRT1-activation effects by liquid chromatography-mass spectrometry and confirm their activities against oxidative damage in H9c2 cardiomyocytes exposed to tert-butyl hydroperoxide (t-BHP). The results showed that those compounds enhanced the deacetylated activity of SIRT1, increased ATP content, and inhibited intracellular ROS formation as well as regulating the activity of Mn-SOD. These SIRT1 activators also showed moderate protective effects on mitochondrial function in t-BHP cells by recovering oxygen consumption and increasing mitochondrial DNA content. Our results suggested that those compounds from TCMs attenuated oxidative stress-induced mitochondrial damage in cardiomyocytes through activation of SIRT1. PMID:26981165

  13. Rev-erb-α modulates skeletal muscle oxidative capacity by regulating mitochondrial biogenesis and autophagy

    PubMed Central

    Woldt, Estelle; Sebti, Yasmine; Solt, Laura A.; Duhem, Christian; Lancel, Steve; Eeckhoute, Jérôme; Hesselink, Matthijs K.C.; Paquet, Charlotte; Delhaye, Stéphane; Shin, Youseung; Kamenecka, Theodore M.; Schaart, Gert; Lefebvre, Philippe; Nevière, Rémi; Burris, Thomas P.; Schrauwen, Patrick; Staels, Bart; Duez, Hélène

    2013-01-01

    The nuclear receptor Rev-erb-α modulates hepatic lipid and glucose metabolism, adipogenesis and the inflammatory response in macrophages. We show here that Rev-erb-α is highly expressed in oxidative skeletal muscle and plays a role in mitochondrial biogenesis and oxidative function, in gain- and loss-of function studies. Rev-erb-α-deficiency in skeletal muscle leads to reduced mitochondrial content and oxidative function, resulting in compromised exercise capacity. This phenotype was recapitulated in isolated fibers and in muscle cells upon Rev-erbα knock-down, while Rev-erb-α over-expression increased the number of mitochondria with improved respiratory capacity. Rev-erb-α-deficiency resulted in deactivation of the Stk11–Ampk–Sirt1–Ppargc1-α signaling pathway, whereas autophagy was up-regulated, resulting in both impaired mitochondrial biogenesis and increased clearance. Muscle over-expression or pharmacological activation of Rev-erb-α increased respiration and exercise capacity. This study identifies Rev-erb-α as a pharmacological target which improves muscle oxidative function by modulating gene networks controlling mitochondrial number and function. PMID:23852339

  14. The Heuristic of Form: Mitochondrial Morphology and the Explanation of Oxidative Phosphorylation.

    PubMed

    Matlin, Karl S

    2016-02-01

    In the 1950s and 1960s, the search for the mechanism of oxidative phosphorylation by biochemists paralleled the description of mitochondrial form by George Palade and Fritiof Sjöstrand using electron microscopy. This paper explores the extent to which biochemists studying oxidative phosphorylation took mitochondrial form into account in the formulation of hypotheses, design of experiments, and interpretation of results. By examining experimental approaches employed by the biochemists studying oxidative phosphorylation, and their interactions with Palade, I suggest that use of mitochondrial form as a guide to experimentation and interpretation varied considerably among investigators. Most notably, Peter Mitchell, whose chemiosmotic hypothesis was ultimately the basis of the correct mechanism of oxidative phosphorylation, incorporated crucial aspects of mitochondrial form into his model that others failed to recognize. I discuss these historical observations in terms of the background and training of the biochemists, as well as a proposed heuristic of form, whose use may increase the possibility that biologically meaningful molecular mechanisms will be discovered.

  15. Mitochondrial metabolism mediates oxidative stress and inflammation in fatty liver

    PubMed Central

    Satapati, Santhosh; Kucejova, Blanka; Duarte, Joao A.G.; Fletcher, Justin A.; Reynolds, Lacy; Sunny, Nishanth E.; He, Tianteng; Nair, L. Arya; Livingston, Kenneth; Fu, Xiaorong; Merritt, Matthew E.; Sherry, A. Dean; Malloy, Craig R.; Shelton, John M.; Lambert, Jennifer; Parks, Elizabeth J.; Corbin, Ian; Magnuson, Mark A.; Browning, Jeffrey D.; Burgess, Shawn C.

    2015-01-01

    Mitochondria are critical for respiration in all tissues; however, in liver, these organelles also accommodate high-capacity anaplerotic/cataplerotic pathways that are essential to gluconeogenesis and other biosynthetic activities. During nonalcoholic fatty liver disease (NAFLD), mitochondria also produce ROS that damage hepatocytes, trigger inflammation, and contribute to insulin resistance. Here, we provide several lines of evidence indicating that induction of biosynthesis through hepatic anaplerotic/cataplerotic pathways is energetically backed by elevated oxidative metabolism and hence contributes to oxidative stress and inflammation during NAFLD. First, in murine livers, elevation of fatty acid delivery not only induced oxidative metabolism, but also amplified anaplerosis/cataplerosis and caused a proportional rise in oxidative stress and inflammation. Second, loss of anaplerosis/cataplerosis via genetic knockdown of phosphoenolpyruvate carboxykinase 1 (Pck1) prevented fatty acid–induced rise in oxidative flux, oxidative stress, and inflammation. Flux appeared to be regulated by redox state, energy charge, and metabolite concentration, which may also amplify antioxidant pathways. Third, preventing elevated oxidative metabolism with metformin also normalized hepatic anaplerosis/cataplerosis and reduced markers of inflammation. Finally, independent histological grades in human NAFLD biopsies were proportional to oxidative flux. Thus, hepatic oxidative stress and inflammation are associated with elevated oxidative metabolism during an obesogenic diet, and this link may be provoked by increased work through anabolic pathways. PMID:26571396

  16. Mechanisms of MDMA (ecstasy)-induced oxidative stress, mitochondrial dysfunction, and organ damage.

    PubMed

    Song, Byoung-Joon; Moon, Kwan-Hoon; Upreti, Vijay V; Eddington, Natalie D; Lee, Insong J

    2010-08-01

    Despite numerous reports about the acute and sub-chronic toxicities caused by MDMA (3,4-methylenedioxymethamphetamine, ecstasy), the underlying mechanism of organ damage is poorly understood. The aim of this review is to present an update of the mechanistic studies on MDMA-mediated organ damage partly caused by increased oxidative/nitrosative stress. Because of the extensive reviews on MDMA-mediated oxidative stress and tissue damage, we specifically focus on the mechanisms and consequences of oxidative-modifications of mitochondrial proteins, leading to mitochondrial dysfunction. We briefly describe a method to systematically identify oxidatively-modified mitochondrial proteins in control and MDMA-exposed rats by using biotin-N-maleimide (biotin-NM) as a sensitive probe for oxidized proteins. We also describe various applications and advantages of this Cys-targeted proteomics method and alternative approaches to overcome potential limitations of this method in studying oxidized proteins from MDMA-exposed tissues. Finally we discuss the mechanism of synergistic drug-interaction between MDMA and other abused substances including alcohol (ethanol) as well as application of this redox-based proteomics method in translational studies for developing effective preventive and therapeutic agents against MDMA-induced organ damage.

  17. Mechanisms of MDMA (Ecstasy)-Induced Oxidative Stress, Mitochondrial Dysfunction, and Organ Damage

    PubMed Central

    Song, Byoung-Joon; Moon, Kwan-Hoon; Upreti, Vijay V.; Eddington, Natalie D.; Lee, Insong J.

    2010-01-01

    Despite numerous reports about the acute and sub-chronic toxicities caused by MDMA (3,4-methylenedioxymethamphetamine, ecstasy), the underlying mechanism of organ damage is poorly understood. The aim of this review is to present an update of the mechanistic studies on MDMA-mediated organ damage partly caused by increased oxidative/nitrosative stress. Because of the extensive reviews on MDMA-mediated oxidative stress and tissue damage, we specifically focus on the mechanisms and consequences of oxidative-modifications of mitochondrial proteins, leading to mitochondrial dysfunction. We briefly describe a method to systematically identify oxidatively-modified mitochondrial proteins in control and MDMA-exposed rats by using biotin-N-maleimide (biotin-NM) as a sensitive probe for oxidized proteins. We also describe various applications and advantages of this Cys-targeted proteomics method and alternative approaches to overcome potential limitations of this method in studying oxidized proteins from MDMA-exposed tissues. Finally we discuss the mechanism of synergistic drug-interaction between MDMA and other abused substances including alcohol (ethanol) as well as application of this redox-based proteomics method in translational studies for developing effective preventive and therapeutic agents against MDMA-induced organ damage. PMID:20420575

  18. NLRX1 dampens oxidative stress and apoptosis in tissue injury via control of mitochondrial activity.

    PubMed

    Stokman, Geurt; Kors, Lotte; Bakker, Pieter J; Rampanelli, Elena; Claessen, Nike; Teske, Gwendoline J D; Butter, Loes; van Andel, Harmen; van den Bergh Weerman, Marius A; Larsen, Per W B; Dessing, Mark C; Zuurbier, Coert J; Girardin, Stephen E; Florquin, Sandrine; Leemans, Jaklien C

    2017-08-07

    Mitochondrial dysfunction is the most prominent source of oxidative stress in acute and chronic kidney disease. NLRX1 is a receptor of the innate immune system that is ubiquitously expressed and localized in mitochondria. We investigated whether NLRX1 may act at the interface of metabolism and innate immunity in a model of oxidative stress. Using a chimeric mouse model for renal ischemia-reperfusion injury, we found that NLRX1 protects against mortality, mitochondrial damage, and epithelial cell apoptosis in an oxidative stress-dependent fashion. We found that NLRX1 regulates oxidative phosphorylation and cell integrity, whereas loss of NLRX1 results in increased oxygen consumption, oxidative stress, and subsequently apoptosis in epithelial cells during ischemia-reperfusion injury. In line, we found that NLRX1 expression in human kidneys decreased during acute renal ischemic injury and acute cellular rejection. Although first implicated in immune regulation, we propose that NLRX1 function extends to the control of mitochondrial activity and prevention of oxidative stress and apoptosis in tissue injury. © 2017 Stokman et al.

  19. Mitochondrial oxidant stress triggers cell death in simulated ischemia-reperfusion.

    PubMed

    Loor, Gabriel; Kondapalli, Jyothisri; Iwase, Hirotaro; Chandel, Navdeep S; Waypa, Gregory B; Guzy, Robert D; Vanden Hoek, Terry L; Schumacker, Paul T

    2011-07-01

    To clarify the relationship between reactive oxygen species (ROS) and cell death during ischemia-reperfusion (I/R), we studied cell death mechanisms in a cellular model of I/R. Oxidant stress during simulated ischemia was detected in the mitochondrial matrix using mito-roGFP, a ratiometric redox sensor, and by Mito-Sox Red oxidation. Reperfusion-induced death was attenuated by over-expression of Mn-superoxide dismutase (Mn-SOD) or mitochondrial phospholipid hydroperoxide glutathione peroxidase (mito-PHGPx), but not by catalase, mitochondria-targeted catalase, or Cu,Zn-SOD. Protection was also conferred by chemically distinct antioxidant compounds, and mito-roGFP oxidation was attenuated by NAC, or by scavenging of residual O(2) during the ischemia (anoxic ischemia). Mitochondrial permeability transition pore (mPTP) oscillation/opening was monitored by real-time imaging of mitochondrial calcein fluorescence. Oxidant stress caused release of calcein to the cytosol during ischemia, a response that was inhibited by chemically diverse antioxidants, anoxia, or over-expression of Mn-SOD or mito-PHGPx. These findings suggest that mitochondrial oxidant stress causes oscillation of the mPTP prior to reperfusion. Cytochrome c release from mitochondria to the cytosol was not detected until after reperfusion, and was inhibited by anoxic ischemia or antioxidant administration during ischemia. Although DNA fragmentation was detected after I/R, no evidence of Bax activation was detected. Over-expression of the anti-apoptotic protein Bcl-X(L) in cardiomyocytes did not confer protection against I/R-induced cell death. Moreover, murine embryonic fibroblasts with genetic depletion of Bax and Bak, or over-expression of Bcl-X(L), failed to show protection against I/R. These findings indicate that mitochondrial ROS during ischemia triggers mPTP activation, mitochondrial depolarization, and cell death during reperfusion through a Bax/Bak-independent cell death pathway. Therefore

  20. Ca2+ acting at the external side of the inner mitochondrial membrane can stimulate mitochondrial permeability transition induced by phenylarsine oxide.

    PubMed

    Kowaltowski, A J; Castilho, R F

    1997-12-15

    Mitochondrial permeability transition (MPT) induced by the thiol cross-linker phenylarsine oxide (PhAsO) in Ca(2+)-depleted mitochondria incubated in the presence of ruthenium red, an inhibitor of the Ca2+ uniporter, is stimulated by the addition of extramitochondrial Ca2+. The presence of extramitochondrial Ca2+ stimulates the reaction of mitochondrial membrane protein thiol groups with PhAsO. Both Ca(2+)-induced increase in mitochondrial membrane permeabilization and protein thiol group reaction with PhAsO are dependent on time (5-10 min to be complete) and the concentration of Ca2+ (1-25 microM). Mitochondrial permeabilization induced by PhAsO (15 microM) and extramitochondrial Ca2+ is inhibited by ADP, cyclosporin A, dibucaine and Mg2+, while mitochondrial permeabilization induced by high concentrations of PhAsO (60 microM) in the absence of Ca2+ is inhibited only by ADP and cyclosporin A. These results suggest that dibucaine and Mg2+ can inhibit mitochondrial permeabilization by antagonizing the effect of Ca2+ on the mitochondrial membrane. Once mitochondrial permeabilization induced by 15 microM PhAsO and extramitochondrial Ca2+ has already occurred, the addition of the Ca2+ chelator EGTA restores mitochondrial membrane potential (MPT pore closure), suggesting that the presence of Ca2+ is essential for the maintenance of the permeability of the mitochondrial membrane to protons (MPT pore opening). In conclusion, the results presented indicate that low Ca2+ concentrations acting at the external side of the inner mitochondrial membrane can stimulate mitochondrial permeability transition induced by PhAsO, due to increased accessibility of protein thiol groups to the reaction with PhAsO and increased probability of MPT pore opening.

  1. PM2.5-Induced Oxidative Stress and Mitochondrial Damage in the Nasal Mucosa of Rats

    PubMed Central

    Guo, Zhiqiang; Hong, Zhicong; Dong, Weiyang; Deng, Congrui; Zhao, Renwu; Xu, Jian; Zhuang, Guoshun; Zhang, Ruxin

    2017-01-01

    Exposure to PM2.5 (particulate matter ≤2.5 μm) increases the risk of nasal lesions, but the underlying mechanisms, especially the mechanisms leading to mitochondrial damage, are still unclear. Thus, we investigated the in vivo effects of PM2.5 exposure on the inflammatory response, oxidative stress, the enzyme activities of Na+K+-ATPase and Ca2+-ATPase, and the morphology and function of mitochondria in the nasal mucosa of rats. Exposure to PM2.5 occurred through inhalation of a PM2.5 solution aerosol. The results show that the PM2.5 exposure induced increased levels of malondialdehyde (MDA) and levels of proinflammatory mediators, including interleukin 6 (IL-6), IL-8, and tumor necrosis factor-α (TNF-α). These changes were accompanied by decreases in the activities of total superoxide dismutase (T-SOD), Na+K+-ATPase, and Ca2+-ATPase in rat nasal mucosa. PM2.5 significantly affected the expression of specific mitochondrial fission/fusion genes (OPA1, Mfn1, Fis1, and Drp1) in nasal mucosa. These changes were accompanied by abnormal alterations of mitochondrial structures, including mitochondrial swelling, cristae disorder, and even fission resulting from higher doses of PM2.5. Our data shows that oxidative damage, inflammatory response, and mitochondrial dysfunction may be the toxic mechanisms that cause nasal lesions after exposure to PM2.5. PMID:28146064

  2. Methylglyoxal induces oxidative stress and mitochondrial dysfunction in osteoblastic MC3T3-E1 cells.

    PubMed

    Suh, K S; Choi, E M; Rhee, S Y; Kim, Y S

    2014-02-01

    Methylglyoxal is a reactive dicarbonyl compound produced by glycolytic processing and identified as a precursor of advanced glycation end products. The elevated methylglyoxal levels in patients with diabetes are believed to contribute to diabetic complications, including bone defects. The objective of this study was to evaluate the effect of methylglyoxal on the function of osteoblastic MC3T3-E1 cells. The data indicated that methylglyoxal decreased osteoblast differentiation and induced osteoblast cytotoxicity. Pretreatment of MC3T3-E1 cells with aminoguanidine (a carbonyl scavenger), Trolox (an antioxidant), and cyclosporin A (a blocker of the mitochondrial permeability transition pore) prevented methylglyoxal-induced cytotoxicity in MC3T3-E1 cells. However, BAPTA/AM (an intracellular Ca(2+) chelator) and dantrolene (an inhibitor of endoplasmic reticulum Ca(2+) release) did not reverse the cytotoxic effect of methylglyoxal. Methylglyoxal increased the formation of intracellular reactive oxygen species, mitochondrial superoxide, and cardiolipin peroxidation in osteoblastic MC3T3-E1 cells. Methylglyoxal also decreased the mitochondrial membrane potential and intracellular ATP and nitric oxide levels, suggesting that carbonyl stress-induced loss of mitochondrial integrity contributes to the cytotoxicity of methylglyoxal. Furthermore, the results demonstrated that methylglyoxal induced protein adduct formation, inactivation of glyoxalase I, and activation of glyoxalase II. Aminoguanidine reversed all aforementioned effects of methylglyoxal. Taken together, these data support the notion that high methylglyoxal concentrations have detrimental effects on osteoblasts through a mechanism involving oxidative stress and mitochondrial dysfunction.

  3. Chlorogenic acid ameliorates endotoxin-induced liver injury by promoting mitochondrial oxidative phosphorylation

    SciTech Connect

    Zhou, Yan; Ruan, Zheng; Zhou, Lili; Shu, Xugang; Sun, Xiaohong; Mi, Shumei; Yang, Yuhui; Yin, Yulong

    2016-01-22

    Acute or chronic hepatic injury is a common pathology worldwide. Mitochondrial dysfunction and the depletion of adenosine triphosphate (ATP) play important roles in liver injury. Chlorogenic acids (CGA) are some of the most abundant phenolic acids in human diet. This study was designed to test the hypothesis that CGA may protect against chronic lipopolysaccharide (LPS)-induced liver injury by modulating mitochondrial energy generation. CGA decreased the activities of serum alanine aminotransferase, aspartate aminotransferase and alkaline phosphatase. The contents of ATP and adenosine monophosphate (AMP), as well as the ratio of AMP/ATP, were increased after CGA supplementation. The activities of enzymes that are involved in glycolysis were reduced, while those of enzymes involved in oxidative phosphorylation were increased. Moreover, phosphorylated AMP-activated protein kinase (AMPK), and mRNA levels of AMPK-α, peroxisome proliferator-activated receptor-gamma coactivator 1α (PGC-1α), nuclear respiratory factor 1, and mitochondrial DNA transcription factor A were increased after CGA supplementation. Collectively, these findings suggest that the hepatoprotective effect of CGA might be associated with enhanced ATP production, the stimulation of mitochondrial oxidative phosphorylation and the inhibition of glycolysis. - Highlights: • Dietary supplementation with chlorogenic acid (CGA) improved endotoxin-induced liver injury. • Chlorogenic acid enhances ATP increase and shifts energy metabolism, which is correlated with up-regulation AMPK and PGC-1α. • The possible mechanism of CGA on mitochondrial biogenesis was correlated with up-regulation AMPK and PGC-1α.

  4. Oxidized mitochondrial nucleoids released by neutrophils drive type I interferon production in human lupus

    PubMed Central

    Caielli, Simone; Athale, Shruti; Domic, Bojana; Murat, Elise; Chandra, Manjari; Banchereau, Romain; Baisch, Jeanine; Phelps, Kate; Clayton, Sandra; Gong, Mei; Wright, Tracey; Punaro, Marilynn; Palucka, Karolina; Guiducci, Cristiana; Banchereau, Jacques

    2016-01-01

    Autoantibodies against nucleic acids and excessive type I interferon (IFN) are hallmarks of human systemic lupus erythematosus (SLE). We previously reported that SLE neutrophils exposed to TLR7 agonist autoantibodies release interferogenic DNA, which we now demonstrate to be of mitochondrial origin. We further show that healthy human neutrophils do not complete mitophagy upon induction of mitochondrial damage. Rather, they extrude mitochondrial components, including DNA (mtDNA), devoid of oxidized (Ox) residues. When mtDNA undergoes oxidation, it is directly routed to lysosomes for degradation. This rerouting requires dissociation from the transcription factor A mitochondria (TFAM), a dual high-mobility group (HMG) protein involved in maintenance and compaction of the mitochondrial genome into nucleoids. Exposure of SLE neutrophils, or healthy IFN-primed neutrophils, to antiribonucleotide protein autoantibodies blocks TFAM phosphorylation, a necessary step for nucleoid dissociation. Consequently, Ox nucleoids accumulate within mitochondria and are eventually extruded as potent interferogenic complexes. In support of the in vivo relevance of this phenomenon, mitochondrial retention of Ox nucleoids is a feature of SLE blood neutrophils, and autoantibodies against Ox mtDNA are present in a fraction of patients. This pathway represents a novel therapeutic target in human SLE. PMID:27091841

  5. A high-fat diet coordinately downregulates genes required for mitochondrial oxidative phosphorylation in skeletal muscle.

    PubMed

    Sparks, Lauren M; Xie, Hui; Koza, Robert A; Mynatt, Randall; Hulver, Matthew W; Bray, George A; Smith, Steven R

    2005-07-01

    Obesity and type 2 diabetes have been associated with a high-fat diet (HFD) and reduced mitochondrial mass and function. We hypothesized a HFD may affect expression of genes involved in mitochondrial function and biogenesis. To test this hypothesis, we fed 10 insulin-sensitive males an isoenergetic HFD for 3 days with muscle biopsies before and after intervention. Oligonucleotide microarray analysis revealed 297 genes were differentially regulated by the HFD (Bonferonni adjusted P < 0.001). Six genes involved in oxidative phosphorylation (OXPHOS) decreased. Four were members of mitochondrial complex I: NDUFB3, NDUFB5, NDUFS1, and NDUFV1; one was SDHB in complex II and a mitochondrial carrier protein SLC25A12. Peroxisome proliferator-activated receptor gamma coactivator-1 (PGC1) alpha and PGC1beta mRNA were decreased by -20%, P < 0.01, and -25%, P < 0.01, respectively. In a separate experiment, we fed C57Bl/6J mice a HFD for 3 weeks and found that the same OXPHOS and PGC1 mRNAs were downregulated by approximately 90%, cytochrome C and PGC1alpha protein by approximately 40%. Combined, these results suggest a mechanism whereby HFD downregulates genes necessary for OXPHOS and mitochondrial biogenesis. These changes mimic those observed in diabetes and insulin resistance and, if sustained, may result in mitochondrial dysfunction in the prediabetic/insulin-resistant state.

  6. Nitric oxide inhibition of Drp1-mediated mitochondrial fission is critical for myogenic differentiation

    PubMed Central

    De Palma, C; Falcone, S; Pisoni, S; Cipolat, S; Panzeri, C; Pambianco, S; Pisconti, A; Allevi, R; Bassi, MT; Cossu, G; Pozzan, T; Moncada, S; Scorrano, L; Brunelli, S; Clementi, E

    2011-01-01

    During myogenic differentiation the short mitochondria of myoblasts change into the extensively elongated network observed in myotubes. The functional relevance and the molecular mechanisms driving the formation of this mitochondrial network are unknown. We now show that mitochondrial elongation is required for myogenesis to occur and that this event depends on the cellular generation of nitric oxide (NO). Inhibition of NO synthesis in myogenic precursor cells leads to inhibition of mitochondrial elongation and of myogenic differentiation. This is due to the enhanced activity, translocation and docking of the pro-fission GTPase dynamin-related protein-1 (Drp1) to mitochondria, leading also to a latent mitochondrial dysfunction that increased sensitivity to apoptotic stimuli. These effects of NO inhibition were not observed in myogenic precursor cells containing a dominant-negative form of Drp1. Both NO-dependent repression of Drp1 action and maintenance of mitochondrial integrity and function were mediated through the soluble guanylate cyclase. These data uncover a novel level of regulation of differentiation linking mitochondrial morphology and function to myogenic differentiation. PMID:20467441

  7. Mitochondrial oxidative stress and dysfunction induced by isoniazid: study on isolated rat liver and brain mitochondria.

    PubMed

    Ahadpour, Morteza; Eskandari, Mohammad Reza; Mashayekhi, Vida; Haj Mohammad Ebrahim Tehrani, Kamaleddin; Jafarian, Iman; Naserzadeh, Parvaneh; Hosseini, Mir-Jamal

    2016-01-01

    Isoniazid (INH or isonicotinic hydrazide) is used for the treatment and prophylaxis of tuberculosis. Liver and brain are two important target organs in INH toxicity. However, the exact mechanisms behind the INH hepatotoxicity or neurotoxicity have not yet been completely understood. Considering the mitochondria as one of the possible molecular targets for INH toxicity, the aim of this study was to evaluate the mechanisms of INH mitochondrial toxicity on isolated mitochondria. Mitochondria were isolated by differential ultracentrifugation from male Sprague-Dawley rats and incubated with different concentrations of INH (25-2000 μM) for the investigation of mitochondrial parameters. The results indicated that INH could interact with mitochondrial respiratory chain and inhibit its activity. Our results showed an elevation in mitochondrial reactive oxygen species (ROS) formation, lipid peroxidation and mitochondrial membrane potential collapse after exposure of isolated liver mitochondria in INH. However, different results were obtained in brain mitochondria. Noteworthy, significant glutathione oxidation, adenosine triphosphate (ATP) depletion and lipid peroxidation were observed in higher concentration of INH, as compared to liver mitochondria. In conclusion, our results suggest that INH may initiate its toxicity in liver mitochondria through interaction with electron transfer chain, lipid peroxidation, mitochondrial membrane potential decline and cytochrome c expulsion which ultimately lead to cell death signaling.

  8. Simvastatin impairs ADP-stimulated respiration and increases mitochondrial oxidative stress in primary human skeletal myotubes

    PubMed Central

    Kwak, Hyo-Bum; Thalacker-Mercer, Anna; Anderson, Ethan J.; Lin, Chien-Te; Kane, Daniel A.; Lee, Nam-Sihk; Cortright, Ronald N.; Bamman, Marcas M.; Neufer, P. Darrell

    2012-01-01

    Statins, the widely prescribed cholesterol-lowering drugs for the treatment of cardiovascular disease, cause adverse skeletal muscle side effects ranging from fatigue to fatal rhabdomyolysis. The purpose of this study was to determine the effects of simvastatin on mitochondrial respiration, oxidative stress, and cell death in differentiated primary human skeletal muscle cells (i.e. myotubes). Simvastatin induced a dose dependent decrease in viability of proliferating and differentiating primary human muscle precursor cells, and a similar dose-dependent effect was noted in differentiated myoblasts and myotubes. Additionally, there were decreases in myotube number and size following 48 h of simvastatin treatment (5 µM). In permeabilized myotubes, maximal ADP-stimulated oxygen consumption, supported by palmitoyl-carnitine + malate (PCM, complex I and II substrates) and glutamate + malate (GM, complex I substrates), was 32–37% lower (P<0.05) in simvastatin treated (5 µM) vs. control myotubes, providing evidence of impaired respiration at complex I. Mitochondrial superoxide and hydrogen peroxide generation were significantly greater in the simvastatin treated human skeletal myotube cultures compared to control. In addition, simvastatin markedly increased protein levels of Bax (pro-apoptotic, +53%) and Bcl-2 (anti-apoptotic, +100%, P<0.05), mitochondrial PTP opening (+44%, P<0.05), and TUNEL-positive nuclei in human skeletal myotubes, demonstrating up-regulation of mitochondrial-mediated myonuclear apoptotic mechanisms. These data demonstrate that simvastatin induces myotube atrophy and cell loss associated with impaired ADP-stimulated maximal mitochondrial respiratory capacity, mitochondrial oxidative stress, and apoptosis in primary human skeletal myotubes, suggesting mitochondrial dysfunction may underlie human statin-induced myopathy. PMID:22080086

  9. Proinflammatory cytokines differentially regulate adipocyte mitochondrial metabolism, oxidative stress, and dynamics

    PubMed Central

    Hahn, Wendy S.; Kuzmicic, Jovan; Burrill, Joel S.; Donoghue, Margaret A.; Foncea, Rocio; Jensen, Michael D.; Lavandero, Sergio; Arriaga, Edgar A.

    2014-01-01

    Proinflammatory cytokines differentially regulate adipocyte mitochondrial metabolism, oxidative stress, and dynamics. Macrophage infiltration of adipose tissue and the chronic low-grade production of inflammatory cytokines have been mechanistically linked to the development of insulin resistance, the forerunner of type 2 diabetes mellitus. In this study, we evaluated the chronic effects of TNFα, IL-6, and IL-1β on adipocyte mitochondrial metabolism and morphology using the 3T3-L1 model cell system. TNFα treatment of cultured adipocytes led to significant changes in mitochondrial bioenergetics, including increased proton leak, decreased ΔΨm, increased basal respiration, and decreased ATP turnover. In contrast, although IL-6 and IL-1β decreased maximal respiratory capacity, they had no effect on ΔΨm and varied effects on ATP turnover, proton leak, or basal respiration. Only TNFα treatment of 3T3-L1 cells led to an increase in oxidative stress (as measured by superoxide anion production and protein carbonylation) and C16 ceramide synthesis. Treatment of 3T3-L1 adipocytes with cytokines led to decreased mRNA expression of key transcription factors and control proteins implicated in mitochondrial biogenesis, including PGC-1α and eNOS as well as deceased expression of COX IV and Cyt C. Whereas each cytokine led to effects on expression of mitochondrial markers, TNFα exclusively led to mitochondrial fragmentation and decreased the total level of OPA1 while increasing OPA1 cleavage, without expression of levels of mitofusin 2, DRP-1, or mitofilin being affected. In summary, these results indicate that inflammatory cytokines have unique and specialized effects on adipocyte metabolism, but each leads to decreased mitochondrial function and a reprogramming of fat cell biology. PMID:24595304

  10. Combined Training Enhances Skeletal Muscle Mitochondrial Oxidative Capacity Independent of Age

    PubMed Central

    Lanza, Ian R.; Henderson, Gregory C.; Rao, Rajesh R.; Spiegelman, Bruce M.

    2015-01-01

    Context: Skeletal muscle from sedentary older adults exhibits reduced mitochondrial abundance and oxidative capacity. Objective: The primary objective was to determine whether 8 weeks of combined training (CT) has a more robust effect than endurance training (ET) or resistance training (RT) on mitochondrial physiology in healthy young (18–30 years) and older (≥65 years) adults. Intervention: Thirty-four young and 31 older adults were randomly assigned to 8 weeks of ET, RT, and control/CT. Control subjects completed 8 weeks of no exercise (control) followed by 8 weeks of CT. Body composition, skeletal muscle strength, and peak oxygen uptake were measured before and after the intervention. Vastus lateralis muscle biopsy samples were obtained before and 48 hours after the intervention. Mitochondrial physiology was evaluated by high-resolution respirometry and expression of mitochondrial proteins and transcription factors by quantitative PCR and immunoblotting. Results: ET and CT significantly increased oxidative capacity and expression of mitochondrial proteins and transcription factors. All training modalities improved body composition, cardiorespiratory fitness, and skeletal muscle strength. CT induced the most robust improvements in mitochondria-related outcomes and physical characteristics despite lower training volumes for the ET and RT components. Importantly, most of the adaptations to training occurred independent of age. Conclusion: Collectively, these results demonstrate that both ET and CT increase muscle mitochondrial abundance and capacity although CT induced the most robust improvements in the outcomes measured. In conclusion, CT provides a robust exercise regimen to improve muscle mitochondrial outcomes and physical characteristics independent of age. PMID:25599385

  11. Mitochondrial reserve capacity in endothelial cells: the impact of nitric oxide and reactive oxygen species

    PubMed Central

    Dranka, Brian P.; Hill, Bradford G.; Darley-Usmar, Victor M.

    2010-01-01

    The endothelium is not considered to be a major energy requiring organ, but nevertheless endothelial cells have an extensive mitochondrial network. This suggests that mitochondrial function may be important in response to stress and signaling in these cells. In this study, we used extracellular flux analysis to measure mitochondrial function in adherent bovine aortic endothelial cells (BAEC). Under basal conditions, BAEC use only ~35% of their maximal respiratory capacity. We calculate that this represents an intermediate respiratory State between States 3 and 4 which we define as Stateapparent equal to 3.64. Interestingly, the apparent respiratory control ratio (maximal mitochondrial oxygen consumption/non-ADP linked respiration) in these cells is on the order of 23 which is substantially higher than that which is frequently obtained with isolated mitochondria. These results suggest that mitochondria in endothelial cells are highly coupled and possess a considerable bioenergetic reserve. Since endothelial cells are exposed to both reactive oxygen and nitrogen species (ROS/RNS) in the course of vascular disease, we hypothesized that this reserve capacity is important in responding to oxidative stress. To test this, we exposed BAEC to NO or ROS alone or in combination. We found that exposure to non-toxic concentrations of NO or low levels of hydrogen peroxide generated from 2,3-dimethoxy-1,4-napthoquinone (DMNQ) had little impact on basal mitochondrial function but both treatments reversibly decreased mitochondrial reserve capacity. However, combined NO and DMNQ treatment resulted in an irreversible loss of reserve capacity and was associated with cell death. These data are consistent with a critical role of mitochondrial reserve capacity in endothelial cells in responding to oxidative stress. PMID:20093177

  12. Simvastatin impairs ADP-stimulated respiration and increases mitochondrial oxidative stress in primary human skeletal myotubes.

    PubMed

    Kwak, Hyo-Bum; Thalacker-Mercer, Anna; Anderson, Ethan J; Lin, Chien-Te; Kane, Daniel A; Lee, Nam-Sihk; Cortright, Ronald N; Bamman, Marcas M; Neufer, P Darrell

    2012-01-01

    Statins, the widely prescribed cholesterol-lowering drugs for the treatment of cardiovascular disease, cause adverse skeletal muscle side effects ranging from fatigue to fatal rhabdomyolysis. The purpose of this study was to determine the effects of simvastatin on mitochondrial respiration, oxidative stress, and cell death in differentiated primary human skeletal muscle cells (i.e., myotubes). Simvastatin induced a dose-dependent decrease in viability of proliferating and differentiating primary human muscle precursor cells, and a similar dose-dependent effect was noted in differentiated myoblasts and myotubes. Additionally, there were decreases in myotube number and size following 48 h of simvastatin treatment (5 μM). In permeabilized myotubes, maximal ADP-stimulated oxygen consumption, supported by palmitoylcarnitine+malate (PCM, complex I and II substrates) and glutamate+malate (GM, complex I substrates), was 32-37% lower (P<0.05) in simvastatin-treated (5 μM) vs control myotubes, providing evidence of impaired respiration at complex I. Mitochondrial superoxide and hydrogen peroxide generation were significantly greater in the simvastatin-treated human skeletal myotube cultures compared to control. In addition, simvastatin markedly increased protein levels of Bax (proapoptotic, +53%) and Bcl-2 (antiapoptotic, +100%, P<0.05), mitochondrial PTP opening (+44%, P<0.05), and TUNEL-positive nuclei in human skeletal myotubes, demonstrating up-regulation of mitochondrial-mediated myonuclear apoptotic mechanisms. These data demonstrate that simvastatin induces myotube atrophy and cell loss associated with impaired ADP-stimulated maximal mitochondrial respiratory capacity, mitochondrial oxidative stress, and apoptosis in primary human skeletal myotubes, suggesting that mitochondrial dysfunction may underlie human statin-induced myopathy.

  13. Bridges between mitochondrial oxidative stress, ER stress and mTOR signaling in pancreatic β cells.

    PubMed

    Wang, Jing; Yang, Xin; Zhang, Jingjing

    2016-08-01

    Pancreatic β cell dysfunction, i.e., failure to provide insulin in concentrations sufficient to control blood sugar, is central to the etiology of all types of diabetes. Current evidence implicates mitochondrial oxidative stress and endoplasmic reticulum (ER) stress in pancreatic β cell loss and impaired insulin secretion. Oxidative and ER stress are interconnected so that misfolded proteins induce reactive oxygen species (ROS) production; likewise, oxidative stress disturbs the ER redox state thereby disrupting correct disulfide bond formation and proper protein folding. mTOR signaling regulates many metabolic processes including protein synthesis, cell growth, survival and proliferation. Oxidative stress inhibits mTORC1, which is considered an important suppressor of mitochondrial oxidative stress in β cells, and ultimately, controls cell survival. The interplay between ER stress and mTORC1 is complicated, since the unfolded protein response (UPR) activation can occur upstream or downstream of mTORC1. Persistent activation of mTORC1 initiates protein synthesis and UPR activation, while in the later phase induces ER stress. Chronic activation of ER stress inhibits Akt/mTORC1 pathway, while under particular settings, acute activation of UPR activates Akt-mTOR signaling. Thus, modulating mitochondrial oxidative stress and ER stress via mTOR signaling may be an approach that will effectively suppress obesity- or glucolipotoxicity-induced metabolic disorders such as insulin resistance and type 2 diabetes mellitus (T2DM). In this review, we focus on the regulations between mTOR signaling and mitochondrial oxidative or ER stress in pancreatic β cells.

  14. Oxidative stress induces mitochondrial dysfunction in a subset of autistic lymphoblastoid cell lines

    PubMed Central

    Rose, S; Frye, R E; Slattery, J; Wynne, R; Tippett, M; Melnyk, S; James, S J

    2014-01-01

    There is an increasing recognition that mitochondrial dysfunction is associated with autism spectrum disorders. However, little attention has been given to the etiology of mitochondrial dysfunction and how mitochondrial abnormalities might interact with other physiological disturbances such as oxidative stress. Reserve capacity is a measure of the ability of the mitochondria to respond to physiological stress. In this study, we demonstrate, for the first time, that lymphoblastoid cell lines (LCLs) derived from children with autistic disorder (AD) have an abnormal mitochondrial reserve capacity before and after exposure to reactive oxygen species (ROS). Ten (44%) of 22 AD LCLs exhibited abnormally high reserve capacity at baseline and a sharp depletion of reserve capacity when challenged with ROS. This depletion of reserve capacity was found to be directly related to an atypical simultaneous increase in both proton-leak respiration and adenosine triphosphate-linked respiration in response to increased ROS in this AD LCL subgroup. In this AD LCL subgroup, 48-hour pretreatment with N-acetylcysteine, a glutathione precursor, prevented these abnormalities and improved glutathione metabolism, suggesting a role for altered glutathione metabolism associated with this type of mitochondrial dysfunction. The results of this study suggest that a significant subgroup of AD children may have alterations in mitochondrial function, which could render them more vulnerable to a pro-oxidant microenvironment as well as intrinsic and extrinsic sources of ROS such as immune activation and pro-oxidant environmental toxins. These findings are consistent with the notion that AD is caused by a combination of genetic and environmental factors. PMID:24690598

  15. Mitochondrial oxidative function in human saponin-skinned muscle fibres: effects of prolonged exercise

    PubMed Central

    Tonkonogi, Michail; Harris, Beorn; Sahlin, Kent

    1998-01-01

    The influence of prolonged exhaustive exercise on mitochondrial oxidative function was investigated in ten men. Muscle biopsies were taken before and after exercise and mitochondrial respiration investigated in fibre bundles made permeable by pretreatment with saponin. After exercise, respiration in the absence of ADP increased by 18 % (P < 0.01), but respiration at suboptimal ADP concentration (0.1 mM) and maximal ADP-stimulated respiration (1 mM ADP) remained unchanged. In the presence of creatine (20 mM), mitochondrial affinity for ADP increased markedly and respiration at suboptimal ADP concentration (0.1 mM) was similar (pre-exercise) or higher (post-exercise; P < 0.05) than with 1 mM ADP alone. The increase in respiratory rate with creatine was correlated to the relative type I fibre area (r = 0.84). Creatine-stimulated respiration increased after prolonged exercise (P < 0.01). The respiratory control index (6.8 ± 0.4, mean ± s.e.m.) and the ratio between respiration at 0.1 and 1 mM ADP (ADP sensitivity index, 0.63 ± 0.03) were not changed after exercise. The sensitivity index was negatively correlated to the relative type I fibre area (r = −0.86). The influence of exercise on muscle oxidative function has for the first time been investigated with the skinned-fibre technique. It is concluded that maximal mitochondrial oxidative power is intact or improved after prolonged exercise, while uncoupled respiration is increased. The latter finding may contribute to the elevated post-exercise oxygen consumption. The finding that the sensitivity of mitochondrial respiration for ADP and creatine are related to fibre-type composition indicates intrinsic differences in the control of mitochondrial respiration between fibres. PMID:9625884

  16. Resveratrol preserves mitochondrial function, stimulates mitochondrial biogenesis, and attenuates oxidative stress in regulatory T cells of mice fed a high-fat diet.

    PubMed

    Wang, Bin; Sun, Jin; Ma, Yuhua; Wu, Guirong; Tian, Yingjie; Shi, Yonghui; Le, Guowei

    2014-09-01

    Consumption of high-fat diet (HFD) is related with increased oxidative stress and dysfunctional mitochondria in many organs. The effects of resveratrol (trans-3,5,4'-trihydroxystilbene) that can protect T lymphocytes in various disease conditions on the HFD-induced apoptosis of CD4(+) CD25(+) CD127(low/-) regulatory T cells (Tregs) were studied, and the possible mechanism was postulated. Resveratrol significantly decreased Tregs death induced by 20-wk HFD, being associated with the reduction of reactive oxygen species production and the alleviation of HFD-induced loss of mitochondrial membrane potential (Δψm) in Tregs. Furthermore, resveratrol increased the expression of factors that regulated mitochondrial biogenesis in Tregs. Finally, resveratrol recovered the HFD-induced activation of apoptotic markers in Tregs. Resveratrol protected Tregs against HFD-induced apoptosis by reducing oxidative stress, restoring mitochondrial functional activities, and stimulating mitochondrial biogenesis. © 2014 Institute of Food Technologists®

  17. Detoxification of Mitochondrial Oxidants and Apoptotic Signaling Are Facilitated by Thioredoxin-2 and Peroxiredoxin-3 during Hyperoxic Injury

    PubMed Central

    Forred, Benjamin J.; Daugaard, Darwin R.; Titus, Brianna K.; Wood, Ryan R.; Floen, Miranda J.; Booze, Michelle L.

    2017-01-01

    Mitochondria play a fundamental role in the regulation of cell death during accumulation of oxidants. High concentrations of atmospheric oxygen (hyperoxia), used clinically to treat tissue hypoxia in premature newborns, is known to elicit oxidative stress and mitochondrial injury to pulmonary epithelial cells. A consequence of oxidative stress in mitochondria is the accumulation of peroxides which are detoxified by the dedicated mitochondrial thioredoxin system. This system is comprised of the oxidoreductase activities of peroxiredoxin-3 (Prx3), thioredoxin-2 (Trx2), and thioredoxin reductase-2 (TrxR2). The goal of this study was to understand the role of the mitochondrial thioredoxin system and mitochondrial injuries during hyperoxic exposure. Flow analysis of the redox-sensitive, mitochondrial-specific fluorophore, MitoSOX, indicated increased levels of mitochondrial oxidant formation in human adenocarcinoma cells cultured in 95% oxygen. Increased expression of Trx2 and TrxR2 in response to hyperoxia were not attributable to changes in mitochondrial mass, suggesting that hyperoxic upregulation of mitochondrial thioredoxins prevents accumulation of oxidized Prx3. Mitochondrial oxidoreductase activities were modulated through pharmacological inhibition of TrxR2 with auranofin and genetically through shRNA knockdown of Trx2 and Prx3. Diminished Trx2 and Prx3 expression was associated with accumulation of mitochondrial superoxide; however, only shRNA knockdown of Trx2 increased susceptibility to hyperoxic cell death and increased phosphorylation of apoptosis signal-regulating kinase-1 (ASK1). In conclusion, the mitochondrial thioredoxin system regulates hyperoxic-mediated death of pulmonary epithelial cells through detoxification of oxidants and regulation of redox-dependent apoptotic signaling. PMID:28045936

  18. Association between heat stress and oxidative stress in poultry; mitochondrial dysfunction and dietary interventions with phytochemicals.

    PubMed

    Akbarian, Abdollah; Michiels, Joris; Degroote, Jeroen; Majdeddin, Maryam; Golian, Abolghasem; De Smet, Stefaan

    2016-01-01

    Heat as a stressor of poultry has been studied extensively for many decades; it affects poultry production on a worldwide basis and has significant impact on well-being and production. More recently, the involvement of heat stress in inducing oxidative stress has received much interest. Oxidative stress is defined as the presence of reactive species in excess of the available antioxidant capacity of animal cells. Reactive species can modify several biologically cellular macromolecules and can interfere with cell signaling pathways. Furthermore, during the last decade, there has been an ever-increasing interest in the use of a wide array of natural feed-delivered phytochemicals that have potential antioxidant properties for poultry. In light of this, the current review aims to (1) summarize the mechanisms through which heat stress triggers excessive superoxide radical production in the mitochondrion and progresses into oxidative stress, (2) illustrate that this pathophysiology is dependent on the intensity and duration of heat stress, (3) present different nutritional strategies for mitigation of mitochondrial dysfunction, with particular focus on antioxidant phytochemicals. Oxidative stress that occurs with heat exposure can be manifest in all parts of the body; however, mitochondrial dysfunction underlies oxidative stress. In the initial phase of acute heat stress, mitochondrial substrate oxidation and electron transport chain activity are increased resulting in excessive superoxide production. During the later stage of acute heat stress, down-regulation of avian uncoupling protein worsens the oxidative stress situation causing mitochondrial dysfunction and tissue damage. Typically, antioxidant enzyme activities are upregulated. Chronic heat stress, however, leads to downsizing of mitochondrial metabolic oxidative capacity, up-regulation of avian uncoupling protein, a clear alteration in the pattern of antioxidant enzyme activities, and depletion of antioxidant

  19. Effects of Astragalus Polysaccharides on Dysfunction of Mitochondrial Dynamics Induced by Oxidative Stress

    PubMed Central

    Huang, Yan-Feng; Lu, Lu; Zhu, Da-Jian; Wang, Ming; Yin, Yi; Chen, De-Xiu; Wei, Lian-Bo

    2016-01-01

    This paper studied the chronic fatigue induced by excessive exercise and the restoration effects of Astragalus polysaccharides (APS) on mitochondria. In vivo, we found that excessive exercise could cause oxidative stress statue which led to morphological and functional changes of mitochondria. The changes, including imbalance between mitochondria fusion-fission processes, activation of mitophagy, and decrease of PGC-1α expression, could be restored by APS. We further confirmed in vitro, and what is more, we found that APS may ameliorate mitochondrial dysfunction through Sirt1 pathway. Based on the results, we may figure out part of the molecular mechanism of mitochondrial amelioration by APS. PMID:26881048

  20. Acyl-CoA thioesterase-2 facilitates mitochondrial fatty acid oxidation in the liver[S

    PubMed Central

    Moffat, Cynthia; Bhatia, Lavesh; Nguyen, Teresa; Lynch, Peter; Wang, Miao; Wang, Dongning; Ilkayeva, Olga R.; Han, Xianlin; Hirschey, Matthew D.; Claypool, Steven M.; Seifert, Erin L.

    2014-01-01

    Acyl-CoA thioesterase (Acot)2 localizes to the mitochondrial matrix and hydrolyses long-chain fatty acyl-CoA into free FA and CoASH. Acot2 is expressed in highly oxi­dative tissues and is poised to modulate mitochondrial FA oxidation (FAO), yet its biological role is unknown. Using a model of adenoviral Acot2 overexpression in mouse liver (Ad-Acot2), we show that Acot2 increases the utilization of FA substrate during the daytime in ad libitum-fed mice, but the nighttime switch to carbohydrate oxidation is similar to control mice. In further support of elevated FAO in Acot2 liver, daytime serum ketones were higher in Ad-Acot2 mice, and overnight fasting led to minimal hepatic steatosis as compared with control mice. In liver mitochondria from Ad-Acot2 mice, phosphorylating O2 consumption was higher with lipid substrate, but not with nonlipid substrate. This increase depended on whether FA could be activated on the outer mitochondrial membrane, suggesting that the FA released by Acot2 could be effluxed from mitochondria then taken back up again for oxidation. This circuit would prevent the build-up of inhibitory long-chain fatty acyl-CoA esters. Altogether, our findings indicate that Acot2 can enhance FAO, possibly by mitigating the accumulation of FAO intermediates within the mitochondrial matrix. PMID:25114170

  1. DAPK2 regulates oxidative stress in cancer cells by preserving mitochondrial function

    PubMed Central

    Schlegel, C R; Georgiou, M L; Misterek, M B; Stöcker, S; Chater, E R; Munro, C E; Pardo, O E; Seckl, M J; Costa-Pereira, A P

    2015-01-01

    Death-associated protein kinase (DAPK) 2 is a serine/threonine kinase that belongs to the DAPK family. Although it shows significant structural differences from DAPK1, the founding member of this protein family, DAPK2 is also thought to be a putative tumour suppressor. Like DAPK1, it has been implicated in programmed cell death, the regulation of autophagy and diverse developmental processes. In contrast to DAPK1, however, few mechanistic studies have been carried out on DAPK2 and the majority of these have made use of tagged DAPK2, which almost invariably leads to overexpression of the protein. As a consequence, physiological roles of this kinase are still poorly understood. Using two genetically distinct cancer cell lines as models, we have identified a new role for DAPK2 in the regulation of mitochondrial integrity. RNA interference-mediated depletion of DAPK2 leads to fundamental metabolic changes, including significantly decreased rate of oxidative phosphorylation in combination with overall destabilised mitochondrial membrane potential. This phenotype is further corroborated by an increase in the production of mitochondrial superoxide anions and increased oxidative stress. This then leads to the activation of classical stress-activated kinases such as ERK, JNK and p38, which is observed on DAPK2 genetic ablation. Interestingly, the generation of oxidative stress is further enhanced on overexpression of a kinase-dead DAPK2 mutant indicating that it is the kinase domain of DAPK2 that is important to maintain mitochondrial integrity and, by inference, for cellular metabolism. PMID:25741596

  2. Two alanine aminotranferases link mitochondrial glycolate oxidation to the major photorespiratory pathway in Arabidopsis and rice.

    PubMed

    Niessen, Markus; Krause, Katrin; Horst, Ina; Staebler, Norma; Klaus, Stephanie; Gaertner, Stefanie; Kebeish, Rashad; Araujo, Wagner L; Fernie, Alisdair R; Peterhansel, Christoph

    2012-04-01

    The major photorespiratory pathway in higher plants is distributed over chloroplasts, mitochondria, and peroxisomes. In this pathway, glycolate oxidation takes place in peroxisomes. It was previously suggested that a mitochondrial glycolate dehydrogenase (GlcDH) that was conserved from green algae lacking leaf-type peroxisomes contributes to photorespiration in Arabidopsis thaliana. Here, the identification of two Arabidopsis mitochondrial alanine:glyoxylate aminotransferases (ALAATs) that link glycolate oxidation to glycine formation are described. By this reaction, the mitochondrial side pathway produces glycine from glyoxylate that can be used in the glycine decarboxylase (GCD) reaction of the major pathway. RNA interference (RNAi) suppression of mitochondrial ALAAT did not result in major changes in metabolite pools under standard conditions or enhanced photorespiratroy flux, respectively. However, RNAi lines showed reduced photorespiratory CO(2) release and a lower CO(2) compensation point. Mitochondria isolated from RNAi lines are incapable of converting glycolate to CO(2), whereas simultaneous overexpression of GlcDH and ALAATs in transiently transformed tobacco leaves enhances glycolate conversion. Furthermore, analyses of rice mitochondria suggest that the side pathway for glycolate oxidation and glycine formation is conserved in monocotyledoneous plants. It is concluded that the photorespiratory pathway from green algae has been functionally conserved in higher plants.

  3. Impact of Antioxidants on Cardiolipin Oxidation in Liposomes: Why Mitochondrial Cardiolipin Serves as an Apoptotic Signal?

    PubMed

    Lokhmatikov, Alexey V; Voskoboynikova, Natalia; Cherepanov, Dmitry A; Skulachev, Maxim V; Steinhoff, Heinz-Jürgen; Skulachev, Vladimir P; Mulkidjanian, Armen Y

    2016-01-01

    Molecules of mitochondrial cardiolipin (CL) get selectively oxidized upon oxidative stress, which triggers the intrinsic apoptotic pathway. In a chemical model most closely resembling the mitochondrial membrane-liposomes of pure bovine heart CL-we compared ubiquinol-10, ubiquinol-6, and alpha-tocopherol, the most widespread naturally occurring antioxidants, with man-made, quinol-based amphiphilic antioxidants. Lipid peroxidation was induced by addition of an azo initiator in the absence and presence of diverse antioxidants, respectively. The kinetics of CL oxidation was monitored via formation of conjugated dienes at 234 nm. We found that natural ubiquinols and ubiquinol-based amphiphilic antioxidants were equally efficient in protecting CL liposomes from peroxidation; the chromanol-based antioxidants, including alpha-tocopherol, were 2-3 times less efficient. Amphiphilic antioxidants, but not natural ubiquinols and alpha-tocopherol, were able, additionally, to protect the CL bilayer from oxidation by acting from the water phase. We suggest that the previously reported therapeutic efficiency of mitochondrially targeted amphiphilic antioxidants is owing to their ability to protect those CL molecules that are inaccessible to natural hydrophobic antioxidants, being trapped within respiratory supercomplexes. The high susceptibility of such occluded CL molecules to oxidation may have prompted their recruitment as apoptotic signaling molecules by nature.

  4. Impact of Antioxidants on Cardiolipin Oxidation in Liposomes: Why Mitochondrial Cardiolipin Serves as an Apoptotic Signal?

    PubMed Central

    Lokhmatikov, Alexey V.; Voskoboynikova, Natalia; Cherepanov, Dmitry A.; Skulachev, Maxim V.; Steinhoff, Heinz-Jürgen; Skulachev, Vladimir P.; Mulkidjanian, Armen Y.

    2016-01-01

    Molecules of mitochondrial cardiolipin (CL) get selectively oxidized upon oxidative stress, which triggers the intrinsic apoptotic pathway. In a chemical model most closely resembling the mitochondrial membrane—liposomes of pure bovine heart CL—we compared ubiquinol-10, ubiquinol-6, and alpha-tocopherol, the most widespread naturally occurring antioxidants, with man-made, quinol-based amphiphilic antioxidants. Lipid peroxidation was induced by addition of an azo initiator in the absence and presence of diverse antioxidants, respectively. The kinetics of CL oxidation was monitored via formation of conjugated dienes at 234 nm. We found that natural ubiquinols and ubiquinol-based amphiphilic antioxidants were equally efficient in protecting CL liposomes from peroxidation; the chromanol-based antioxidants, including alpha-tocopherol, were 2-3 times less efficient. Amphiphilic antioxidants, but not natural ubiquinols and alpha-tocopherol, were able, additionally, to protect the CL bilayer from oxidation by acting from the water phase. We suggest that the previously reported therapeutic efficiency of mitochondrially targeted amphiphilic antioxidants is owing to their ability to protect those CL molecules that are inaccessible to natural hydrophobic antioxidants, being trapped within respiratory supercomplexes. The high susceptibility of such occluded CL molecules to oxidation may have prompted their recruitment as apoptotic signaling molecules by nature. PMID:27313834

  5. Cardiovascular Mitochondrial Dysfunction Induced by Cocaine: Biomarkers and Possible Beneficial Effects of Modulators of Oxidative Stress

    PubMed Central

    Magnifico, Maria Chiara

    2017-01-01

    Cocaine abuse has long been known to cause morbidity and mortality due to its cardiovascular toxic effects. The pathogenesis of the cardiovascular toxicity of cocaine use has been largely reviewed, and the most recent data indicate a fundamental role of oxidative stress in cocaine-induced cardiovascular toxicity, indicating that mitochondrial dysfunction is involved in the mechanisms of oxidative stress. The comprehension of the mechanisms involving mitochondrial dysfunction could help in selecting the most appropriate mitochondria injury biological marker, such as superoxide dismutase-2 activity and glutathionylated hemoglobin. The potential use of modulators of oxidative stress (mitoubiquinone, the short-chain quinone idebenone, and allopurinol) in the treatment of cocaine cardiotoxic effects is also suggested to promote further investigations on these potential mitochondria-targeted antioxidant strategies. PMID:28593024

  6. Acetaldehyde-induced mitochondrial dysfunction sensitizes hepatocytes to oxidative damage.

    PubMed

    Farfán Labonne, Blanca Eugenia; Gutiérrez, Mario; Gómez-Quiroz, Luis Enrique; Konigsberg Fainstein, Mina; Bucio, Leticia; Souza, Verónica; Flores, Oscar; Ortíz, Victor; Hernández, Elizabeth; Kershenobich, David; Gutiérrez-Ruíz, María Concepción

    2009-12-01

    Acetaldehyde (Ac), the main metabolite of ethanol oxidation, is a very reactive compound involved in alcohol-induced liver damage. In the present work, we studied the effect of Ac in mitochondria functionality. Mitochondria from Wistar rats were isolated and treated with Ac. Ac decreased respiratory control by 50% which was associated with a decrease in adenosine triphosphate content (28.5%). These results suggested that Ac could be inducing changes in cell redox status. We determined protein oxidation, superoxide dismutase (SOD) activity, and glutathione ratio, indicating that Ac induced an enhanced oxidation of proteins and a decrease in SOD activity (90%) and glutathione/oxidized GSH ratio (36%). The data suggested that Ac-induced oxidative stress mediated by mitochondria dysfunction can lead to cell sensitization and to a second oxidative challenge. We pretreated hepatocytes with Ac followed by treatment with antimycin A, and this experiment revealed a noticeable decrease in cell viability, determined by neutral red assay, in comparison with cells treated with Ac alone. Our data demonstrate that Ac impairs mitochondria functionality generating oxidative stress that sensitizes cells to a second damaging signal contributing to the development of alcoholic liver disease.

  7. The effect of high-intensity training on mitochondrial fat oxidation in skeletal muscle and subcutaneous adipose tissue.

    PubMed

    Larsen, S; Danielsen, J H; Søndergård, S D; Søgaard, D; Vigelsoe, A; Dybboe, R; Skaaby, S; Dela, F; Helge, J W

    2015-02-01

    High-intensity interval training (HIT) is known to increase mitochondrial content in a similar way as endurance training [60-90% of maximal oxygen uptake (VO2peak)]. Whether HIT increases the mitochondria's ability to oxidize lipids is currently debated. We investigated the effect of HIT on mitochondrial fat oxidation in skeletal muscle and adipose tissue. Mitochondrial oxidative phosphorylation (OXPHOS) capacity, mitochondrial substrate sensitivity (K(m)(app)), and mitochondrial content were measured in skeletal muscle and adipose tissue in healthy overweight subjects before and after 6 weeks of HIT (three times per week at 298 ± 21 W). HIT significantly increased VO2peak from 2.9 ± 0.2 to 3.1 ± 0.2 L/min. No differences were seen in maximal fat oxidation in either skeletal muscle or adipose tissue. K(m)(app) for octanoyl carnitine or palmitoyl carnitine were similar after training in skeletal muscle and adipose tissue. Maximal OXPHOS capacity with complex I- and II-linked substrates was increased after training in skeletal muscle but not in adipose tissue. In conclusion, 6 weeks of HIT increased VO2peak. Mitochondrial content and mitochondrial OXPHOS capacity were increased in skeletal muscle, but not in adipose tissue. Furthermore, mitochondrial fat oxidation was not improved in either skeletal muscle or adipose tissue. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  8. Glutaredoxin 2 catalyzes the reversible oxidation and glutathionylation of mitochondrial membrane thiol proteins: implications for mitochondrial redox regulation and antioxidant DEFENSE.

    PubMed

    Beer, Samantha M; Taylor, Ellen R; Brown, Stephanie E; Dahm, Christina C; Costa, Nikola J; Runswick, Michael J; Murphy, Michael P

    2004-11-12

    The redox poise of the mitochondrial glutathione pool is central in the response of mitochondria to oxidative damage and redox signaling, but the mechanisms are uncertain. One possibility is that the oxidation of glutathione (GSH) to glutathione disulfide (GSSG) and the consequent change in the GSH/GSSG ratio causes protein thiols to change their redox state, enabling protein function to respond reversibly to redox signals and oxidative damage. However, little is known about the interplay between the mitochondrial glutathione pool and protein thiols. Therefore we investigated how physiological GSH/GSSG ratios affected the redox state of mitochondrial membrane protein thiols. Exposure to oxidized GSH/GSSG ratios led to the reversible oxidation of reactive protein thiols by thiol-disulfide exchange, the extent of which was dependent on the GSH/GSSG ratio. There was an initial rapid phase of protein thiol oxidation, followed by gradual oxidation over 30 min. A large number of mitochondrial proteins contain reactive thiols and most of these formed intraprotein disulfides upon oxidation by GSSG; however, a small number formed persistent mixed disulfides with glutathione. Both protein disulfide formation and glutathionylation were catalyzed by the mitochondrial thiol transferase glutaredoxin 2 (Grx2), as were protein deglutathionylation and the reduction of protein disulfides by GSH. Complex I was the most prominent protein that was persistently glutathionylated by GSSG in the presence of Grx2. Maintenance of complex I with an oxidized GSH/GSSG ratio led to a dramatic loss of activity, suggesting that oxidation of the mitochondrial glutathione pool may contribute to the selective complex I inactivation seen in Parkinson's disease. Most significantly, Grx2 catalyzed reversible protein glutathionylation/deglutathionylation over a wide range of GSH/GSSG ratios, from the reduced levels accessible under redox signaling to oxidized ratios only found under severe oxidative

  9. Age-related differences in experimental stroke: possible involvement of mitochondrial dysfunction and oxidative damage.

    PubMed

    Li, Nanlin; Kong, Xiangwei; Ye, Ruidong; Yang, Qianzi; Han, Junliang; Xiong, Lize

    2011-06-01

    Age is the single most important risk factor for cerebral stroke. Unfortunately, the effect of age on ischemic brain damage is less clear. In this study, we sought to examine the potential influence of aging on the histologic and functional outcomes after ischemia. Juvenile (4 weeks of age), young adult (4 months of age), mid-aged (11-12 months of age), and aged (18-19 months of age) mice were subjected to transient middle cerebral artery occlusion. There was no remarkable difference of infarct volume on postoperative days 1 and 3. However, on postoperative day 7, aged mice exhibited significantly worsened infarct volume compared with juvenile and young mice. Intriguingly, the increase of infarct volume was most prominent in the striatal area rather than in cortex. Accordingly, aged mice displayed a slower and incomplete functional recovery after stroke. We further evaluated the effects of aging on the oxidative damage and mitochondrial dysfunction following ischemia. Brain tissues were assayed for lipid, DNA, and protein peroxidation products, mitochondrial enzyme activities, mitochondrial membrane potential, production of reactive oxygen species, and antioxidant activities. Aging was associated with declined mitochondrial function and antioxidant detoxification following ischemia, thereby inducing a deteriorated oxidative damage. Regional subanalyses demonstrated that, in accordance with infarct area, the pro-oxidant/antioxidant imbalance occurred more prominently in subcortical areas. Collectively, these findings suggest mitochondria-mediated oxidative damage may be involved in the age-related aggravated injury in subcortical areas. Mitochondrial protection could be a promising target for neuroprotective therapy, especially in the aged population.

  10. Regulation of mitochondrial oxidative stress by β-arrestins in cultured human cardiac fibroblasts

    PubMed Central

    Philip, Jennifer L.; Razzaque, Md. Abdur; Han, Mei; Li, Jinju; Theccanat, Tiju; Xu, Xianyao; Akhter, Shahab A.

    2015-01-01

    ABSTRACT Oxidative stress in cardiac fibroblasts (CFs) promotes transformation to myofibroblasts and collagen synthesis leading to myocardial fibrosis, a precursor to heart failure (HF). NADPH oxidase 4 (Nox4) is a major source of cardiac reactive oxygen species (ROS); however, mechanisms of Nox4 regulation are unclear. β-arrestins are scaffold proteins that signal in G-protein-dependent and -independent pathways; for example, in ERK activation. We hypothesize that β-arrestins regulate oxidative stress in a Nox4-dependent manner and increase fibrosis in HF. CFs were isolated from normal and failing adult human left ventricles. Mitochondrial ROS/superoxide production was quantitated using MitoSox. β-arrestin and Nox4 expressions were manipulated using adenoviral overexpression or short interfering RNA (siRNA)-mediated knockdown. Mitochondrial oxidative stress and Nox4 expression in CFs were significantly increased in HF. Nox4 knockdown resulted in inhibition of mitochondrial superoxide production and decreased basal and TGF-β-stimulated collagen and α-SMA expression. CF β-arrestin expression was upregulated fourfold in HF. β-arrestin knockdown in failing CFs decreased ROS and Nox4 expression by 50%. β-arrestin overexpression in normal CFs increased mitochondrial superoxide production twofold. These effects were prevented by inhibition of either Nox or ERK. Upregulation of Nox4 seemed to be a primary mechanism for increased ROS production in failing CFs, which stimulates collagen deposition. β-arrestin expression was upregulated in HF and plays an important and newly identified role in regulating mitochondrial superoxide production via Nox4. The mechanism for this effect seems to be ERK-mediated. Targeted inhibition of β-arrestins in CFs might decrease oxidative stress as well as pathological cardiac fibrosis. PMID:26449263

  11. Chronically ischemic mouse skeletal muscle exhibits myopathy in association with mitochondrial dysfunction and oxidative damage.

    PubMed

    Pipinos, Iraklis I; Swanson, Stanley A; Zhu, Zhen; Nella, Aikaterini A; Weiss, Dustin J; Gutti, Tanuja L; McComb, Rodney D; Baxter, B Timothy; Lynch, Thomas G; Casale, George P

    2008-07-01

    A myopathy characterized by mitochondrial pathology and oxidative stress is present in patients with peripheral arterial disease (PAD). Patients with PAD differ in disease severity, mode of presentation, and presence of comorbid conditions. In this study, we used a mouse model of hindlimb ischemia to isolate and directly investigate the effects of chronic inflow arterial occlusion on skeletal muscle microanatomy, mitochondrial function and expression, and oxidative stress. Hindlimb ischemia was induced by staged ligation/division of the common femoral and iliac arteries in C57BL/6 mice, and muscles were harvested 12 wk later. Muscle microanatomy was examined by bright-field microscopy, and mitochondrial content was determined as citrate synthase activity in muscle homogenates and ATP synthase expression by fluorescence microscopy. Electron transport chain (ETC) complexes I through IV were analyzed individually by respirometry. Oxidative stress was assessed as total protein carbonyls and 4-hydroxy-2-nonenal (HNE) adducts and altered expression and activity of manganese superoxide dismutase (MnSOD). Ischemic muscle exhibited histological features of myopathy and increased mitochondrial content compared with control muscle. Complex-dependent respiration was significantly reduced for ETC complexes I, III, and IV in ischemic muscle. Protein carbonyls, HNE adducts, and MnSOD expression were significantly increased in ischemic muscle. MnSOD activity was not significantly changed, suggesting MnSOD inactivation. Using a mouse model, we have demonstrated for the first time that inflow arterial occlusion alone, i.e., in the absence of other comorbid conditions, causes myopathy with mitochondrial dysfunction and increased oxidative stress, recapitulating the muscle pathology of PAD patients.

  12. CARDIOSELECTIVE OXIDATION OF MITOCHONDRIAL DNA FOLLOWING SUBCHRONIC ADMINISTRATION OF DOXORUBICIN

    EPA Science Inventory

    This preferential oxidation of cardiac mtDNA is consistent with the bioenergetic failure and the cumulative and irreversible cardiomyopathy that limits the clinical utility of this important antineoplastic drug.

  13. CARDIOSELECTIVE OXIDATION OF MITOCHONDRIAL DNA FOLLOWING SUBCHRONIC ADMINISTRATION OF DOXORUBICIN

    EPA Science Inventory

    This preferential oxidation of cardiac mtDNA is consistent with the bioenergetic failure and the cumulative and irreversible cardiomyopathy that limits the clinical utility of this important antineoplastic drug.

  14. Mitochondrial nitric oxide production supported by reverse electron transfer.

    PubMed

    Bombicino, Silvina S; Iglesias, Darío E; Zaobornyj, Tamara; Boveris, Alberto; Valdez, Laura B

    2016-10-01

    Heart phosphorylating electron transfer particles (ETPH) produced NO at 1.2 ± 0.1 nmol NO. min(-1) mg protein(-1) by the mtNOS catalyzed reaction. These particles showed a NAD(+) reductase activity of 64 ± 3 nmol min(-1) mg protein(-1) sustained by reverse electron transfer (RET) at expenses of ATP and succinate. The same particles, without NADPH and in conditions of RET produced 0.97 ± 0.07 nmol NO. min(-1) mg protein(-1). Rotenone inhibited NO production supported by RET measured in ETPH and in coupled mitochondria, but did not reduce the activity of recombinant nNOS, indicating that the inhibitory effect of rotenone on NO production is due to an electron flow inhibition and not to a direct action on mtNOS structure. NO production sustained by RET corresponds to 20% of the total amount of NO released from heart coupled mitochondria. A mitochondrial fraction enriched in complex I produced 1.7 ± 0.2 nmol NO. min(-1) mg protein(-1) and reacted with anti-75 kDa complex I subunit and anti-nNOS antibodies, suggesting that complex I and mtNOS are located contiguously. These data show that mitochondrial NO production can be supported by RET, and suggest that mtNOS is next to complex I, reaffirming the idea of a functional association between these proteins. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. Excess lipid availability increases mitochondrial fatty acid oxidative capacity in muscle: evidence against a role for reduced fatty acid oxidation in lipid-induced insulin resistance in rodents.

    PubMed

    Turner, Nigel; Bruce, Clinton R; Beale, Susan M; Hoehn, Kyle L; So, Trina; Rolph, Michael S; Cooney, Gregory J

    2007-08-01

    A reduced capacity for mitochondrial fatty acid oxidation in skeletal muscle has been proposed as a major factor leading to the accumulation of intramuscular lipids and their subsequent deleterious effects on insulin action. Here, we examine markers of mitochondrial fatty acid oxidative capacity in rodent models of insulin resistance associated with an oversupply of lipids. C57BL/6J mice were fed a high-fat diet for either 5 or 20 weeks. Several markers of muscle mitochondrial fatty acid oxidative capacity were measured, including (14)C-palmitate oxidation, palmitoyl-CoA oxidation in isolated mitochondria, oxidative enzyme activity (citrate synthase, beta-hydroxyacyl CoA dehydrogenase, medium-chain acyl-CoA dehydrogenase, and carnitine palmitoyl-transferase 1), and expression of proteins involved in mitochondrial metabolism. Enzyme activity and mitochondrial protein expression were also examined in muscle from other rodent models of insulin resistance. Compared with standard diet-fed controls, muscle from fat-fed mice displayed elevated palmitate oxidation rate (5 weeks +23%, P < 0.05, and 20 weeks +29%, P < 0.05) and increased palmitoyl-CoA oxidation in isolated mitochondria (20 weeks +49%, P < 0.01). Furthermore, oxidative enzyme activity and protein expression of peroxisome proliferator-activated receptor gamma coactivator (PGC)-1alpha, uncoupling protein (UCP) 3, and mitochondrial respiratory chain subunits were significantly elevated in fat-fed animals. A similar pattern was present in muscle of fat-fed rats, obese Zucker rats, and db/db mice, with increases observed for oxidative enzyme activity and expression of PGC-1alpha, UCP3, and subunits of the mitochondrial respiratory chain. These findings suggest that high lipid availability does not lead to intramuscular lipid accumulation and insulin resistance in rodents by decreasing muscle mitochondrial fatty acid oxidative capacity.

  16. Increase in oxidative stress and mitochondrial impairment in hypothalamus of streptozotocin treated diabetic rat: Antioxidative effect of Withania somnifera.

    PubMed

    Parihar, P; Shetty, R; Ghafourifar, P; Parihar, M S

    2016-01-22

    Hypothalamus, the primary brain region for glucose sensing, is severely affected by oxidative stress in diabetes mellitus. Oxidative stress in this region of brain may cause severe impairment in neuronal metabolic functions. Mitochondria are prominent targets of oxidative stress and the combination of increased oxidative stress and mitochondrial dysfunctions may further decline hypothalamic neuronal functions. In the present study we examined the oxidative damage response, antioxidative responses and mitochondrial membrane permeability transition in hypothalamus of streptozotocin-treated diabetic rats. Our results show that streptozotocin significantly increases hypothalamic lipid peroxidation, protein carbonyl content while glutathione peroxidase and reduced glutathione were declined. Mitochondrial impairment marked by an increase in mitochondrial membrane permeabilization was seen following streptozotocin treatment in the hypothalamus. The oral administration of Withania somnifera root extract stabilized mitochondrial functions and prevented oxidative damage in the hypothalamus of diabetic rat. These findings suggest an increase in the oxidative stress and decline in antioxidative responses in the hypothalamus of streptozotocin treated diabetic rats. Withania somnifera root extract was found useful in reducing oxidative stress and mitochondrial impairment in hypothalamus of diabetic rat.

  17. The Mitochondrial Disulfide Relay System: Roles in Oxidative Protein Folding and Beyond

    PubMed Central

    2013-01-01

    Disulfide bond formation drives protein import of most proteins of the mitochondrial intermembrane space (IMS). The main components of this disulfide relay machinery are the oxidoreductase Mia40 and the sulfhydryl oxidase Erv1/ALR. Their precise functions have been elucidated in molecular detail for the yeast and human enzymes in vitro and in intact cells. However, we still lack knowledge on how Mia40 and Erv1/ALR impact cellular and organism physiology and whether they have functions beyond their role in disulfide bond formation. Here we summarize the principles of oxidation-dependent protein import mediated by the mitochondrial disulfide relay. We proceed by discussing recently described functions of Mia40 in the hypoxia response and of ALR in influencing mitochondrial morphology and its importance for tissue development and embryogenesis. We also include a discussion of the still mysterious function of Erv1/ALR in liver regeneration. PMID:24348563

  18. Metformin increases APP expression and processing via oxidative stress, mitochondrial dysfunction and NF-κB activation: Use of insulin to attenuate metformin's effect.

    PubMed

    Picone, Pasquale; Nuzzo, Domenico; Caruana, Luca; Messina, Elisa; Barera, Annalisa; Vasto, Sonya; Di Carlo, Marta

    2015-05-01

    Clinical and experimental biomedical studies have shown Type 2 diabetes mellitus (T2DM) to be a risk factor for the development of Alzheimer's disease (AD). This study demonstrates the effect of metformin, a therapeutic biguanide administered for T2DM therapy, on β-amyloid precursor protein (APP) metabolism in in vitro, ex vivo and in vivo models. Furthermore, the protective role of insulin against metformin is also demonstrated. In LAN5 neuroblastoma cells, metformin increases APP and presenilin levels, proteins involved in AD. Overexpression of APP and presenilin 1 (Pres 1) increases APP cleavage and intracellular accumulation of β-amyloid peptide (Aβ), which, in turn, promotes aggregation of Aβ. In the experimental conditions utilized the drug causes oxidative stress, mitochondrial damage, decrease of Hexokinase-II levels and cytochrome C release, all of which lead to cell death. Several changes in oxidative stress-related genes following metformin treatment were detected by PCR arrays specific for the oxidative stress pathway. These effects of metformin were found to be antagonized by the addition of insulin, which reduced Aβ levels, oxidative stress, mitochondrial dysfunction and cell death. Similarly, antioxidant molecules, such as ferulic acid and curcumin, are able to revert metformin's effect. Comparable results were obtained using peripheral blood mononuclear cells. Finally, the involvement of NF-κB transcription factor in regulating APP and Pres 1 expression was investigated. Upon metformin treatment, NF-κB is activated and translocates from the cytoplasm to the nucleus, where it induces increased APP and Pres 1 transcription. The use of Bay11-7085 inhibitor suppressed the effect of metformin on APP and Pres 1 expression. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. High fructose causes cardiac hypertrophy via mitochondrial signaling pathway

    PubMed Central

    Zhang, Yan-Bo; Meng, Yan-Hai; Chang, Shuo; Zhang, Rong-Yuan; Shi, Chen

    2016-01-01

    High fructose diet can cause cardiac hypertrophy and oxidative stress is a key mediator for myocardial hypertrophy. Disruption of cystic fibrosis transmembrane conductance regulator (CFTR) leads to oxidative stress. This study aims to reveal mitochondrial oxidative stress-related signaling pathway in high fructose-induced cardiac hypertrophy. Mice were fed high fructose to develop cardiac hypertrophy. Fructose and H2O2 were used to induce cardiomyocyte hypertrophy in vitro. Mitochondria-targeted antioxidant SkQ1 was applied to investigate the possible role of mitochondrial reactive oxygen species (ROS). CFTR silence was performed to detect the role of CFTR in high fructose-induced myocardial hypertrophy. ROS, glutathione (GSH), mitochondrial function and hypertrophic markers were measured. We confirmed that long-term high fructose diet caused cardiac hypertrophy and diastolic dysfunction and elevated mitochondrial ROS. However, SkQ1 administration prevented heart hypertrophy and mitochondrial oxidative stress. Cadiomyocytes incubated with fructose or H2O2 exhibited significantly increased cell areas but SkQ1 treatment ameliorated cardiomyocyte hypertrophy induced by high fructose or H2O2 in vitro. Those results revealed that the underlying mechanism for high fructose-induced heart hypertrophy was attributed to mitochondrial oxidative stress. Moreover, CFTR expression was decreased by high fructose intervention and CFTR silence resulted in an increase in mitochondrial ROS, which suggested high fructose diet affected mitochondrial oxidative stress by regulating CFTR expression. Electron transport chain impairment might be related to mitochondrial oxidative damage. In conclusion, our findings indicated that mitochondrial oxidative stress plays a central role in pathogenesis of high fructose-induced cardiac hypertrophy. High fructose decreases CFTR expression to regulate mitochondrial oxidative stress. PMID:27904687

  20. Impaired enzymatic defensive activity, mitochondrial dysfunction and proteasome activation are involved in RTT cell oxidative damage.

    PubMed

    Cervellati, Carlo; Sticozzi, Claudia; Romani, Arianna; Belmonte, Giuseppe; De Rasmo, Domenico; Signorile, Anna; Cervellati, Franco; Milanese, Chiara; Mastroberardino, Pier Giorgio; Pecorelli, Alessandra; Savelli, Vinno; Forman, Henry J; Hayek, Joussef; Valacchi, Giuseppe

    2015-10-01

    A strong correlation between oxidative stress (OS) and Rett syndrome (RTT), a rare neurodevelopmental disorder affecting females in the 95% of the cases, has been well documented although the source of OS and the effect of a redox imbalance in this pathology has not been yet investigated. Using freshly isolated skin fibroblasts from RTT patients and healthy subjects, we have demonstrated in RTT cells high levels of H2O2 and HNE protein adducts. These findings correlated with the constitutive activation of NADPH-oxidase (NOX) and that was prevented by a NOX inhibitor and iron chelator pre-treatment, showing its direct involvement. In parallel, we demonstrated an increase in mitochondrial oxidant production, altered mitochondrial biogenesis and impaired proteasome activity in RTT samples. Further, we found that the key cellular defensive enzymes: glutathione peroxidase, superoxide dismutase and thioredoxin reductases activities were also significantly lower in RTT. Taken all together, our findings suggest that the systemic OS levels in RTT can be a consequence of both: increased endogenous oxidants as well as altered mitochondrial biogenesis with a decreased activity of defensive enzymes that leads to posttranslational oxidant protein modification and a proteasome activity impairment.

  1. Organization of the human mitochondrial hydrogen sulfide oxidation pathway.

    PubMed

    Libiad, Marouane; Yadav, Pramod Kumar; Vitvitsky, Victor; Martinov, Michael; Banerjee, Ruma

    2014-11-07

    Sulfide oxidation is expected to play an important role in cellular switching between low steady-state intracellular hydrogen sulfide levels and the higher concentrations where the physiological effects are elicited. Yet despite its significance, fundamental questions regarding how the sulfide oxidation pathway is wired remain unanswered, and competing proposals exist that diverge at the very first step catalyzed by sulfide quinone oxidoreductase (SQR). We demonstrate that, in addition to sulfite, glutathione functions as a persulfide acceptor for human SQR and that rhodanese preferentially synthesizes rather than utilizes thiosulfate. The kinetic behavior of these enzymes provides compelling evidence for the flow of sulfide via SQR to glutathione persulfide, which is then partitioned to thiosulfate or sulfite. Kinetic simulations at physiologically relevant metabolite concentrations provide additional support for the organizational logic of the sulfide oxidation pathway in which glutathione persulfide is the first intermediate formed.

  2. Dexmedetomidine attenuates lipopolysaccharide-induced acute lung injury by inhibiting oxidative stress, mitochondrial dysfunction and apoptosis in rats

    PubMed Central

    Fu, Chunlai; Dai, Xingui; Yang, You; Lin, Mengxiang; Cai, Yeping; Cai, Shaoxi

    2016-01-01

    Previous studies have identified that dexmedetomidine (DEX) treatment can ameliorate the acute lung injury (ALI) induced by lipopolysaccharide and ischemia-reperfusion. However, the molecular mechanisms by which DEX ameliorates lung injury remain unclear. The present study investigated whether DEX, which has been reported to exert effects on oxidative stress, mitochondrial permeability transition pores and apoptosis in other disease types, can exert protective effects in lipopolysaccharide (LPS)-induced ALI by inhibiting oxidative stress, mitochondrial dysfunction and mitochondrial-dependent apoptosis. It was revealed that LPS-challenged rats exhibited significant lung injury, characterized by the deterioration of histopathology, vascular hyperpermeability, wet-to-dry weight ratio and oxygenation index (PaO2/FIO2), which was attenuated by DEX treatment. DEX treatment inhibited LPS-induced mitochondrial dysfunction, as evidenced by alleviating the cellular ATP and mitochondrial membrane potential in vitro. In addition, DEX treatment markedly prevented the LPS-induced mitochondrial-dependent apoptotic pathway in vitro (increases of cell apoptotic rate, cytosolic cytochrome c, and caspase 3 activity) and in vivo (increases of |terminal deoxynucleotidyl transferase dUTP nick-end labeling positive cells, cleaved caspase 3, Bax upregulation and Bcl-2 downregulation). Furthermore, DEX treatment markedly attenuated LPS-induced oxidative stress, as evidenced by downregulation of cellular reactive oxygen species in vitro and lipid peroxides in serum. Collectively, the present results demonstrated that DEX ameliorates LPS-induced ALI by reducing oxidative stress, mitochondrial dysfunction and mitochondrial-dependent apoptosis. PMID:27959438

  3. Epigallocatechin-3-gallate prevents oxidative phosphorylation deficit and promotes mitochondrial biogenesis in human cells from subjects with Down's syndrome.

    PubMed

    Valenti, Daniela; De Rasmo, Domenico; Signorile, Anna; Rossi, Leonardo; de Bari, Lidia; Scala, Iris; Granese, Barbara; Papa, Sergio; Vacca, Rosa Anna

    2013-04-01

    A critical role for mitochondrial dysfunction has been proposed in the pathogenesis of Down's syndrome (DS), a human multifactorial disorder caused by trisomy of chromosome 21, associated with mental retardation and early neurodegeneration. Previous studies from our group demonstrated in DS cells a decreased capacity of the mitochondrial ATP production system and overproduction of reactive oxygen species (ROS) in mitochondria. In this study we have tested the potential of epigallocatechin-3-gallate (EGCG) - a natural polyphenol component of green tea - to counteract the mitochondrial energy deficit found in DS cells. We found that EGCG, incubated with cultured lymphoblasts and fibroblasts from DS subjects, rescued mitochondrial complex I and ATP synthase catalytic activities, restored oxidative phosphorylation efficiency and counteracted oxidative stress. These effects were associated with EGCG-induced promotion of PKA activity, related to increased cellular levels of cAMP and PKA-dependent phosphorylation of the NDUFS4 subunit of complex I. In addition, EGCG strongly promoted mitochondrial biogenesis in DS cells, as associated with increase in Sirt1-dependent PGC-1α deacetylation, NRF-1 and T-FAM protein levels and mitochondrial DNA content. In conclusion, this study shows that EGCG is a promoting effector of oxidative phosphorylation and mitochondrial biogenesis in DS cells, acting through modulation of the cAMP/PKA- and sirtuin-dependent pathways. EGCG treatment promises thus to be a therapeutic approach to counteract mitochondrial energy deficit and oxidative stress in DS.

  4. Mitochondrial function and antioxidative defence in human muscle: effects of endurance training and oxidative stress

    PubMed Central

    Tonkonogi, Michail; Walsh, Brandon; Svensson, Michael; Sahlin, Kent

    2000-01-01

    The influence of endurance training on oxidative phosphorylation and the susceptibility of mitochondrial oxidative function to reactive oxygen species (ROS) was investigated in skeletal muscle of four men and four women. Mitochondria were isolated from muscle biopsies taken before and after 6 weeks of endurance training. Mitochondrial respiration was measured before and after exposure of mitochondria to exogenous ROS (H2O2+ FeCl2). Endurance training increased peak pulmonary O2 uptake (V̇O2,peak) by 24 % and maximal ADP-stimulated mitochondrial oxygen consumption (state 3) by 40 % (P < 0.05). Respiration in the absence of ADP (state 4), the respiratory control ratio (RCR = state 3/state 4) and the ratio between added ADP and consumed oxygen (P/O) remained unchanged by the training programme. Exposure to ROS reduced state 3 respiration but the effect was not significantly different between pre- and post-training samples. State 4 oxygen consumption increased after exposure to ROS both before (+189 %, P < 0.05) and after training (+243 %, P < 0.05) and the effect was significantly higher after training (P < 0.05, pre- vs. post-training). The augmented state 4 respiration could in part be attenuated by atractyloside, which indicates that ADP/ATP translocase was affected by ROS. The P/O ratio in ROS-treated mitochondria was significantly lower (P < 0.05) compared to control conditions, both before (−18.6 ± 2.2 %) and after training (−18.5 ± 1.1 %). Muscle activities of superoxide dismutase (mitochondrial and cytosolic), glutathione peroxidase and muscle glutathione status were unaffected by training. There was a positive correlation between muscle superoxide dismutase activity and age (r= 0.75; P < 0.05; range of age 20–37 years), which may reflect an adaptation to increased generation of ROS in senescent muscle. The muscle glutathione pool was more reduced in subjects with high activity of glutathione peroxidase (r= 0.81; P < 0.05). The influence of short

  5. Regulation of mitochondrial function and endoplasmic reticulum stress by nitric oxide in pluripotent stem cells.

    PubMed

    Caballano-Infantes, Estefania; Terron-Bautista, José; Beltrán-Povea, Amparo; Cahuana, Gladys M; Soria, Bernat; Nabil, Hajji; Bedoya, Francisco J; Tejedo, Juan R

    2017-02-26

    Mitochondrial dysfunction and endoplasmic reticulum stress (ERS) are global processes that are interrelated and regulated by several stress factors. Nitric oxide (NO) is a multifunctional biomolecule with many varieties of physiological and pathological functions, such as the regulation of cytochrome c inhibition and activation of the immune response, ERS and DNA damage; these actions are dose-dependent. It has been reported that in embryonic stem cells, NO has a dual role, controlling differentiation, survival and pluripotency, but the molecular mechanisms by which it modulates these functions are not yet known. Low levels of NO maintain pluripotency and induce mitochondrial biogenesis. It is well established that NO disrupts the mitochondrial respiratory chain and causes changes in mitochondrial Ca(2+) flux that induce ERS. Thus, at high concentrations, NO becomes a potential differentiation agent due to the relationship between ERS and the unfolded protein response in many differentiated cell lines. Nevertheless, many studies have demonstrated the need for physiological levels of NO for a proper ERS response. In this review, we stress the importance of the relationships between NO levels, ERS and mitochondrial dysfunction that control stem cell fate as a new approach to possible cell therapy strategies.

  6. Regulation of mitochondrial function and endoplasmic reticulum stress by nitric oxide in pluripotent stem cells

    PubMed Central

    Caballano-Infantes, Estefania; Terron-Bautista, José; Beltrán-Povea, Amparo; Cahuana, Gladys M; Soria, Bernat; Nabil, Hajji; Bedoya, Francisco J; Tejedo, Juan R

    2017-01-01

    Mitochondrial dysfunction and endoplasmic reticulum stress (ERS) are global processes that are interrelated and regulated by several stress factors. Nitric oxide (NO) is a multifunctional biomolecule with many varieties of physiological and pathological functions, such as the regulation of cytochrome c inhibition and activation of the immune response, ERS and DNA damage; these actions are dose-dependent. It has been reported that in embryonic stem cells, NO has a dual role, controlling differentiation, survival and pluripotency, but the molecular mechanisms by which it modulates these functions are not yet known. Low levels of NO maintain pluripotency and induce mitochondrial biogenesis. It is well established that NO disrupts the mitochondrial respiratory chain and causes changes in mitochondrial Ca2+ flux that induce ERS. Thus, at high concentrations, NO becomes a potential differentiation agent due to the relationship between ERS and the unfolded protein response in many differentiated cell lines. Nevertheless, many studies have demonstrated the need for physiological levels of NO for a proper ERS response. In this review, we stress the importance of the relationships between NO levels, ERS and mitochondrial dysfunction that control stem cell fate as a new approach to possible cell therapy strategies. PMID:28289506

  7. Does the oxidative stress theory of aging explain longevity differences in birds? I. Mitochondrial ROS production.

    PubMed

    Montgomery, Magdalene K; Hulbert, A J; Buttemer, William A

    2012-03-01

    Mitochondrial reactive oxygen species (ROS) production rates are reported to be inversely related to maximum lifespan potential (MLSP) in mammals and also to be higher in short-living mammals compared to short-living birds. The mammal-bird comparison, however, is mainly based on studies of rats and pigeons. To date, there has been no systematic examination of ROS production in birds that differ in MLSP. Here we report a comparison of mitochondrial ROS production in two short-living (quails) and three long-living bird species (parrots) that exhibit, on average, a 5-fold longevity difference. Mitochondrial ROS production was determined both in isolated mitochondria (heart, skeletal muscle and liver) as traditionally done and also in intact erythrocytes. In all four tissues, mitochondrial ROS production was similar in quails and parrots and showed no correspondence with known longevity differences. The lack of a consistent difference between quails and parrots was not due to differences in mitochondrial content as ROS production in relation to oxygen consumption (determined as the free radical leak) showed a similar pattern. These findings cast doubt on the robustness of the oxidative stress theory of aging.

  8. Mitochondrial ATP synthases cluster as discrete domains that reorganize with the cellular demand for oxidative phosphorylation.

    PubMed

    Jimenez, Laure; Laporte, Damien; Duvezin-Caubet, Stephane; Courtout, Fabien; Sagot, Isabelle

    2014-02-15

    Mitochondria are double membrane-bounded organelles that form a dynamic tubular network. Mitochondria energetic functions depend on a complex internal architecture. Cristae, inner membrane invaginations that fold into the matrix space, are proposed to be the site of oxidative phosphorylation, reactions by which ATP synthase produces ATP. ATP synthase is also thought to have a role in crista morphogenesis. To date, the exploration of the processes regulating mitochondrial internal compartmentalization have been mostly limited to electron microscopy. Here, we describe ATP synthase localization in living yeast cells and show that it clusters as discrete inner membrane domains. These domains are dynamic within the mitochondrial network. They are impaired in mutants defective in crista morphology and partially overlap with the crista-associated MICOS-MINOS-MITOS complex. Finally, ATP synthase occupancy increases with the cellular demand for OXPHOS. Overall our data suggest that domains in which ATP synthases are clustered correspond to mitochondrial cristae. Being able to follow mitochondrial sub-compartments in living yeast cells opens new avenues to explore the mechanisms involved in inner membrane remodeling, an architectural feature crucial for mitochondrial activities.

  9. Oxidative Stress and Mitochondrial Dysfunction across Broad-Ranging Pathologies: Toward Mitochondria-Targeted Clinical Strategies

    PubMed Central

    d'Ischia, Marco; Gadaleta, Maria Nicola; Pallardó, Federico V.; Petrović, Sandra; Tiano, Luca; Zatterale, Adriana

    2014-01-01

    Beyond the disorders recognized as mitochondrial diseases, abnormalities in function and/or ultrastructure of mitochondria have been reported in several unrelated pathologies. These encompass ageing, malformations, and a number of genetic or acquired diseases, as diabetes and cardiologic, haematologic, organ-specific (e.g., eye or liver), neurologic and psychiatric, autoimmune, and dermatologic disorders. The mechanistic grounds for mitochondrial dysfunction (MDF) along with the occurrence of oxidative stress (OS) have been investigated within the pathogenesis of individual disorders or in groups of interrelated disorders. We attempt to review broad-ranging pathologies that involve mitochondrial-specific deficiencies or rely on cytosol-derived prooxidant states or on autoimmune-induced mitochondrial damage. The established knowledge in these subjects warrants studies aimed at elucidating several open questions that are highlighted in the present review. The relevance of OS and MDF in different pathologies may establish the grounds for chemoprevention trials aimed at compensating OS/MDF by means of antioxidants and mitochondrial nutrients. PMID:24876913

  10. Interrelationships between mitochondrial fusion, energy metabolism and oxidative stress during development in Caenorhabditis elegans

    SciTech Connect

    Yasuda, Kayo; Hartman, Philip S.; Ishii, Takamasa; Suda, Hitoshi; Akatsuka, Akira; Shoyama, Tetsuji; Miyazawa, Masaki; Ishii, Naoaki

    2011-01-21

    Research highlights: {yields} Growth and development of a fzo-1 mutant defective in the fusion process of mitochondria was delayed relative to the wild type of Caenorhabditis elegans. {yields} Oxygen sensitivity during larval development, superoxide production and carbonyl protein accumulation of the fzo-1 mutant were similar to wild type. {yields} fzo-1 animals had significantly lower metabolism than did N2 and mev-1 overproducing superoxide from mitochondrial electron transport complex II. {yields} Mitochondrial fusion can profoundly affect energy metabolism and development. -- Abstract: Mitochondria are known to be dynamic structures with the energetically and enzymatically mediated processes of fusion and fission responsible for maintaining a constant flux. Mitochondria also play a role of reactive oxygen species production as a byproduct of energy metabolism. In the current study, interrelationships between mitochondrial fusion, energy metabolism and oxidative stress on development were explored using a fzo-1 mutant defective in the fusion process and a mev-1 mutant overproducing superoxide from mitochondrial electron transport complex II of Caenorhabditis elegans. While growth and development of both single mutants was slightly delayed relative to the wild type, the fzo-1;mev-1 double mutant experienced considerable delay. Oxygen sensitivity during larval development, superoxide production and carbonyl protein accumulation of the fzo-1 mutant were similar to wild type. fzo-1 animals had significantly lower metabolism than did N2 and mev-1. These data indicate that mitochondrial fusion can profoundly affect energy metabolism and development.

  11. Mitochondrial fat oxidation is essential for lipid-induced inflammation in skeletal muscle in mice.

    PubMed

    Warfel, Jaycob D; Bermudez, Estrellita M; Mendoza, Tamra M; Ghosh, Sujoy; Zhang, Jingying; Elks, Carrie M; Mynatt, Randall; Vandanmagsar, Bolormaa

    2016-11-28

    Inflammation, lipotoxicity and mitochondrial dysfunction have been implicated in the pathogenesis of obesity-induced insulin resistance and type 2 diabetes. However, how these factors are intertwined in the development of obesity/insulin resistance remains unclear. Here, we examine the role of mitochondrial fat oxidation on lipid-induced inflammation in skeletal muscle. We used skeletal muscle-specific Cpt1b knockout mouse model where the inhibition of mitochondrial fatty acid oxidation results in accumulation of lipid metabolites in muscle and elevated circulating free fatty acids. Gene expression of pro-inflammatory cytokines, chemokines, and cytokine- and members of TLR-signalling pathways were decreased in Cpt1b(m-/-) muscle. Inflammatory signalling pathways were not activated when evaluated by multiplex and immunoblot analysis. In addition, the inflammatory response to fatty acids was reduced in primary muscle cells derived from Cpt1b(m-/-) mice. Gene expression of Cd11c, the M1 macrophage marker, was decreased; while Cd206, the M2 macrophage marker, was increased in skeletal muscle of Cpt1b(m-/-) mice. Finally, expression of pro-inflammatory markers was decreased in white adipose tissue of Cpt1b(m-/-) mice. We show that the inflammatory response elicited by elevated intracellular lipids in skeletal muscle is repressed in Cpt1b(m-/-) mice, strongly supporting the hypothesis that mitochondrial processing of fatty acids is essential for the lipid-induction of inflammation in muscle.

  12. Mitochondrial fat oxidation is essential for lipid-induced inflammation in skeletal muscle in mice

    PubMed Central

    Warfel, Jaycob D.; Bermudez, Estrellita M.; Mendoza, Tamra M.; Ghosh, Sujoy; Zhang, Jingying; Elks, Carrie M.; Mynatt, Randall; Vandanmagsar, Bolormaa

    2016-01-01

    Inflammation, lipotoxicity and mitochondrial dysfunction have been implicated in the pathogenesis of obesity-induced insulin resistance and type 2 diabetes. However, how these factors are intertwined in the development of obesity/insulin resistance remains unclear. Here, we examine the role of mitochondrial fat oxidation on lipid-induced inflammation in skeletal muscle. We used skeletal muscle-specific Cpt1b knockout mouse model where the inhibition of mitochondrial fatty acid oxidation results in accumulation of lipid metabolites in muscle and elevated circulating free fatty acids. Gene expression of pro-inflammatory cytokines, chemokines, and cytokine- and members of TLR-signalling pathways were decreased in Cpt1bm−/− muscle. Inflammatory signalling pathways were not activated when evaluated by multiplex and immunoblot analysis. In addition, the inflammatory response to fatty acids was reduced in primary muscle cells derived from Cpt1bm−/− mice. Gene expression of Cd11c, the M1 macrophage marker, was decreased; while Cd206, the M2 macrophage marker, was increased in skeletal muscle of Cpt1bm−/− mice. Finally, expression of pro-inflammatory markers was decreased in white adipose tissue of Cpt1bm−/− mice. We show that the inflammatory response elicited by elevated intracellular lipids in skeletal muscle is repressed in Cpt1bm−/− mice, strongly supporting the hypothesis that mitochondrial processing of fatty acids is essential for the lipid-induction of inflammation in muscle. PMID:27892502

  13. Perfluorooctanoic acid induces oxidative damage and mitochondrial dysfunction in pancreatic β-cells.

    PubMed

    Suh, Kwang Sik; Choi, Eun Mi; Kim, Yu Jin; Hong, Soo Min; Park, So Yong; Rhee, Sang Youl; Oh, Seungjoon; Kim, Sung Woon; Pak, Youngmi Kim; Choe, Wonchae; Chon, Suk

    2017-06-01

    Several environmental contaminants have been linked to the development of diabetes and increased diabetes‑associated mortality. Perfluorooctanoic acid (PFOA) is a widely used perfluoroalkane found in surfactants and lubricants, and in processing aids used in the production of polymers. Furthermore, PFOA has been detected in humans, wildlife and the environment. The present study investigated the toxic effects of PFOA on rat pancreatic β‑cell‑derived RIN‑m5F cells. Cell viability, apoptosis, reactive oxygen and nitrogen species, cytokine release and mitochondrial parameters, including membrane potential collapse, reduced adenosine triphosphate levels, cardiolipin peroxidation and cytochrome c release were assessed. PFOA significantly decreased RIN‑m5F cell viability and increased apoptosis. Exposure to PFOA increased the formation of reactive oxygen species, mitochondrial superoxide, nitric oxide and proinflammatory cytokines. Furthermore, PFOA induced mitochondrial membrane potential collapse and reduced adenosine triphosphate levels, cardiolipin peroxidation and cytochrome c release. These results indicate that PFOA is associated with the induction of apoptosis in RIN-m5F cells, and induces cytotoxicity via increased oxidative stress and mitochondrial dysfunction.

  14. Nitrite-nitric oxide control of mitochondrial respiration at the frontier of anoxia.

    PubMed

    Benamar, Abdelilah; Rolletschek, Hardy; Borisjuk, Ljudmilla; Avelange-Macherel, Marie-Hélène; Curien, Gilles; Mostefai, H Ahmed; Andriantsitohaina, Ramaroson; Macherel, David

    2008-10-01

    Actively respiring animal and plant tissues experience hypoxia because of mitochondrial O(2) consumption. Controlling oxygen balance is a critical issue that involves in mammals hypoxia-inducible factor (HIF) mediated transcriptional regulation, cytochrome oxidase (COX) subunit adjustment and nitric oxide (NO) as a mediator in vasodilatation and oxygen homeostasis. In plants, NO, mainly derived from nitrite, is also an important signalling molecule. We describe here a mechanism by which mitochondrial respiration is adjusted to prevent a tissue to reach anoxia. During pea seed germination, the internal atmosphere was strongly hypoxic due to very active mitochondrial respiration. There was no sign of fermentation, suggesting a down-regulation of O(2) consumption near anoxia. Mitochondria were found to finely regulate their surrounding O(2) level through a nitrite-dependent NO production, which was ascertained using electron paramagnetic resonance (EPR) spin trapping of NO within membranes. At low O(2), nitrite is reduced into NO, likely at complex III, and in turn reversibly inhibits COX, provoking a rise to a higher steady state level of oxygen. Since NO can be re-oxidized into nitrite chemically or by COX, a nitrite-NO pool is maintained, preventing mitochondrial anoxia. Such an evolutionarily conserved mechanism should have an important role for oxygen homeostasis in tissues undergoing hypoxia.

  15. Mitochondrial calcium and oxidative stress as mediators of ischemic brain injury.

    PubMed

    Starkov, Anatoly A; Chinopoulos, Christos; Fiskum, Gary

    2004-01-01

    Acute ischemic and brain injury is triggered by excitotoxic elevation of intraneuronal Ca2+ followed by reoxygenation-dependent oxidative stress, metabolic failure, and cell death. Studies performed in vitro with neurons exposed to excitotoxic concentrations of glutamate demonstrate an initial rise in cytosolic [Ca2+], followed by a reduction to a normal, albeit slightly elevated concentration. This reduction in cytosolic [Ca2+] is due partially to active, respiration-dependent mitochondrial Ca2+ sequestration. Within minutes to an hour following the initial Ca2+ transient, most neurons undergo delayed Ca2+ deregulation characterized by a dramatic rise in cytosolic Ca2+. This prelethal secondary rise in Ca2+ is due to influx across the plasma membrane but is dependent on the initial mitochondrial Ca2+ uptake and associated oxidative stress. Mitochondrial Ca2+ uptake can stimulate the net production of reactive oxygen species (ROS) through activation of the membrane permeability transition, release of cytochrome c, respiratory inhibition, release of pyridine nucleotides, and loss of intramitochondrial glutathione necessary for detoxification of peroxides. Targets of mitochondrially derived ROS may include plasma membrane Ca2+ channels that mediate excitotoxic delayed Ca2+ deregulation.

  16. Chronic treadmill running does not enhance mitochondrial oxidative capacity in the cortex or striatum.

    PubMed

    Herbst, Eric A F; Roussakis, Christina; Matravadia, Sarthak; Holloway, Graham P

    2015-11-01

    The aims of the present study were to determine in healthy animals if 1) acute exercise stimulated traditional exercise signaling pathways in the cortex and striatum, and 2) if chronic exercise training increased the oxidative capacity of these brain regions. Male C57BL/6 mice were left sedentary, acutely exercised for 15 or 60 min to examine potential signaling cascades activated by exercise, or chronically exercise for 4 wk to examine the impact of prolonged training. The cortex and striatum were analyzed for changes in the phosphorylation of AMPK, CAMKII, ERK1/2, and P38 with acute exercise, or markers of mitochondrial protein content, mtDNA copy number, and mitochondrial respiration with chronic exercise. In mice, acute treadmill running did not alter the phosphorylation of AMPK, CAMKII, or P38 in either the cortex or the striatum, but decreased ERK1/2 phosphorylation in only the cortex for the duration of the exercise bout. Following chronic exercise training, mitochondrial respiration, mtDNA copy number, and protein content of various subunits of the electron transport chain were not altered in adult mice. Combined, these data suggest that exercise does not result in increased phosphorylation of traditional signaling kinases or enhanced mitochondrial oxidative capacity in either the cortex or the striatum of healthy animals. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. Acetylation of mitochondrial proteins by GCN5L1 promotes enhanced fatty acid oxidation in the heart.

    PubMed

    Thapa, Dharendra; Zhang, Manling; Manning, Janet R; Guimarães, Danielle A; Stoner, Michael W; O'Doherty, Robert M; Shiva, Sruti; Scott, Iain

    2017-08-01

    Lysine acetylation is a reversible posttranslational modification and is particularly important in the regulation of mitochondrial metabolic enzymes. Acetylation uses acetyl-CoA derived from fuel metabolism as a cofactor, thereby linking nutrition to metabolic activity. In the present study, we investigated how mitochondrial acetylation status in the heart is controlled by food intake and how these changes affect mitochondrial metabolism. We found that there was a significant increase in cardiac mitochondrial protein acetylation in mice fed a long-term high-fat diet and that this change correlated with an increase in the abundance of the mitochondrial acetyltransferase-related protein GCN5L1. We showed that the acetylation status of several mitochondrial fatty acid oxidation enzymes (long-chain acyl-CoA dehydrogenase, short-chain acyl-CoA dehydrogenase, and hydroxyacyl-CoA dehydrogenase) and a pyruvate oxidation enzyme (pyruvate dehydrogenase) was significantly upregulated in high-fat diet-fed mice and that the increase in long-chain and short-chain acyl-CoA dehydrogenase acetylation correlated with increased enzymatic activity. Finally, we demonstrated that the acetylation of mitochondrial fatty acid oxidation proteins was decreased after GCN5L1 knockdown and that the reduced acetylation led to diminished fatty acid oxidation in cultured H9C2 cells. These data indicate that lysine acetylation promotes fatty acid oxidation in the heart and that this modification is regulated in part by the activity of GCN5L1.NEW & NOTEWORTHY Recent research has shown that acetylation of mitochondrial fatty acid oxidation enzymes has greatly contrasting effects on their activity in different tissues. Here, we provide new evidence that acetylation of cardiac mitochondrial fatty acid oxidation enzymes by GCN5L1 significantly upregulates their activity in diet-induced obese mice. Copyright © 2017 the American Physiological Society.

  18. Animation Model to Conceptualize ATP Generation: A Mitochondrial Oxidative Phosphorylation

    ERIC Educational Resources Information Center

    Jena, Ananta Kumar

    2015-01-01

    Adenosine triphosphate (ATP) is the molecular unit of intracellular energy and it is the product of oxidative phosphorylation of cellular respiration uses in cellular processes. The study explores the growth of the misconception levels amongst the learners and evaluates the effectiveness of animation model over traditional methods. The data…

  19. [Malate oxidation by mitochondrial succinate:ubiquinone-reductase].

    PubMed

    Belikova, Iu O; Kotliar, A B

    1988-04-01

    Succinate:ubiquinone reductase was shown to catalyze the oxidation of L- and D-stereoisomers of malate by artificial electron acceptors and ubiquinone. The rate of malate oxidation by succinate:ubiquinone reductase is by two orders of magnitude lower than that for the natural substrate--succinate. The values of kinetic constants for the oxidation of D- and L-stereoisomers of malate are equal to: V infinity = 0.1 mumol/min/mg protein, Km = 2 mM and V infinity = 0.05 mumol/min/mg protein, Km = 2 mM, respectively. The malate dehydrogenase activity is fully inhibited by the inhibitors of the dicarboxylate-binding site of the enzyme, i.e., N-ethylmaleimide and malonate and is practically insensitive to carboxin, a specific inhibitor of the ubiquinone-binding center. The enol form of oxaloacetate was shown to be the product of malate oxidation by succinate:ubiquinone reductase. The kinetics of inhibition of the enzyme activity by the ketone and enol forms of oxaloacetate was studied. Both forms of oxaloacetate effectively inhibit the succinate:ubiquinone reductase reaction.

  20. Protection against oxidant-induced apoptosis by mitochondrial thioredoxin in SH-SY5Y neuroblastoma cells

    SciTech Connect

    Chen Yan; Yu Min; Jones, Dean P.; Greenamyre, J. Timothy; Cai Jiyang . E-mail: jiyang.cai@vanderbilt.edu

    2006-10-15

    Mitochondrial oxidative stress plays important roles in aging and age-related degenerative disorders. The newly identified mitochondrial thioredoxin (mtTrx; Trx2) is a key component of the mitochondrial antioxidant system which is responsible for the clearance of reactive intermediates and repairs proteins with oxidative damage. Here, we show that in cultured SH-SY5Y human neuroblastoma 1cells, overexpression of mtTrx inhibited apoptosis and loss of mitochondrial membrane potential induced by a chemical oxidant, tert-butylhydroperoxide (tBH). The effects of calcium ionophore (Br-A23187) were not affected by mtTrx, suggesting the protection was specific against oxidative injury. The mitochondrial glutathione pool was oxidized by tBH, and this oxidation was not inhibited by increased mtTrx. Consequently, the antioxidant function of mtTrx is not redundant, but rather in addition, to that of GSH. Mutations of Cys90 and Cys93 to serines rendered mtTrx ineffective in protection against tBH-induced cytoxicity. These data indicate that mtTrx controls the mitochondrial redox status independently of GSH and is a key component of the defensive mechanism against oxidative stress in cultured neuronal cells.

  1. Exposure to 1800 MHz radiofrequency radiation induces oxidative damage to mitochondrial DNA in primary cultured neurons.

    PubMed

    Xu, Shangcheng; Zhou, Zhou; Zhang, Lei; Yu, Zhengping; Zhang, Wei; Wang, Yuan; Wang, Xubu; Li, Maoquan; Chen, Yang; Chen, Chunhai; He, Mindi; Zhang, Guangbin; Zhong, Min

    2010-01-22

    Increasing evidence indicates that oxidative stress may be involved in the adverse effects of radiofrequency (RF) radiation on the brain. Because mitochondrial DNA (mtDNA) defects are closely associated with various nervous system diseases and mtDNA is particularly susceptible to oxidative stress, the purpose of this study was to determine whether radiofrequency radiation can cause oxidative damage to mtDNA. In this study, we exposed primary cultured cortical neurons to pulsed RF electromagnetic fields at a frequency of 1800 MHz modulated by 217 Hz at an average special absorption rate (SAR) of 2 W/kg. At 24 h after exposure, we found that RF radiation induced a significant increase in the levels of 8-hydroxyguanine (8-OHdG), a common biomarker of DNA oxidative damage, in the mitochondria of neurons. Concomitant with this finding, the copy number of mtDNA and the levels of mitochondrial RNA (mtRNA) transcripts showed an obvious reduction after RF exposure. Each of these mtDNA disturbances could be reversed by pretreatment with melatonin, which is known to be an efficient antioxidant in the brain. Together, these results suggested that 1800 MHz RF radiation could cause oxidative damage to mtDNA in primary cultured neurons. Oxidative damage to mtDNA may account for the neurotoxicity of RF radiation in the brain.

  2. Defects in Mitochondrial and Peroxisomal β-Oxidation Influence Virulence in the Maize Pathogen Ustilago maydis

    PubMed Central

    Kretschmer, Matthias; Klose, Jana

    2012-01-01

    An understanding of metabolic adaptation during the colonization of plants by phytopathogenic fungi is critical for developing strategies to protect crops. Lipids are abundant in plant tissues, and fungal phytopathogens in the phylum basidiomycota possess both peroxisomal and mitochondrial β-oxidation pathways to utilize this potential carbon source. Previously, we demonstrated a role for the peroxisomal β-oxidation enzyme Mfe2 in the filamentous growth, virulence, and sporulation of the maize pathogen Ustilago maydis. However, mfe2 mutants still caused disease symptoms, thus prompting a more detailed investigation of β-oxidation. We now demonstrate that a defect in the had1 gene encoding hydroxyacyl coenzyme A dehydrogenase for mitochondrial β-oxidation also influences virulence, although its paralog, had2, makes only a minor contribution. Additionally, we identified a gene encoding a polypeptide with similarity to the C terminus of Mfe2 and designated it Mfe2b; this gene makes a contribution to virulence only in the background of an mfe2Δ mutant. We also show that short-chain fatty acids induce cell death in U. maydis and that a block in β-oxidation leads to toxicity, likely because of the accumulation of toxic intermediates. Overall, this study reveals that β-oxidation has a complex influence on the formation of disease symptoms by U. maydis that includes potential metabolic contributions to proliferation in planta and an effect on virulence-related morphogenesis. PMID:22707484

  3. Bioenergetics, mitochondrial dysfunction, and oxidative stress in the pathophysiology of septic encephalopathy.

    PubMed

    Bozza, Fernando A; D'Avila, Joana C; Ritter, Cristiane; Sonneville, Romain; Sharshar, Tarek; Dal-Pizzol, Felipe

    2013-05-01

    Sepsis is a major cause of mortality and morbidity in intensive care units. Acute and long-term brain dysfunctions have been demonstrated both in experimental models and septic patients. Sepsis-associated encephalopathy is an early and frequent manifestation but is underdiagnosed, because of the absence of specific biomarkers and of confounding factors such as sedatives used in the intensive care unit. Sepsis-associated encephalopathy may have acute and long-term consequences including development of autonomic dysfunction, delirium, and cognitive impairment. The mechanisms of sepsis-associated encephalopathy involve mitochondrial and vascular dysfunctions, oxidative stress, neurotransmission disturbances, inflammation, and cell death. Here we review specific evidence that links bioenergetics, mitochondrial dysfunction, and oxidative stress in the setting of brain dysfunctions associated to sepsis.

  4. Sex-dependent mitochondrial respiratory impairment and oxidative stress in a rat model of neonatal hypoxic-ischemic encephalopathy.

    PubMed

    Demarest, Tyler G; Schuh, Rosemary A; Waddell, Jaylyn; McKenna, Mary C; Fiskum, Gary

    2016-06-01

    Increased male susceptibility to long-term cognitive deficits is well described in clinical and experimental studies of neonatal hypoxic-ischemic encephalopathy. While cell death signaling pathways are known to be sexually dimorphic, a sex-dependent pathophysiological mechanism preceding the majority of secondary cell death has yet to be described. Mitochondrial dysfunction contributes to cell death following cerebral hypoxic-ischemia (HI). Several lines of evidence suggest that there are sex differences in the mitochondrial metabolism of adult mammals. Therefore, this study tested the hypothesis that brain mitochondrial respiratory impairment and associated oxidative stress is more severe in males than females following HI. Maximal brain mitochondrial respiration during oxidative phosphorylation was two-fold more impaired in males following HI. The endogenous antioxidant glutathione was 30% higher in the brain of sham females compared to males. Females also exhibited increased glutathione peroxidase (GPx) activity following HI injury. Conversely, males displayed a reduction in mitochondrial GPx4 protein levels and mitochondrial GPx activity. Moreover, a 3-4-fold increase in oxidative protein carbonylation was observed in the cortex, perirhinal cortex, and hippocampus of injured males, but not females. These data provide the first evidence for sex-dependent mitochondrial respiratory dysfunction and oxidative damage, which may contribute to the relative male susceptibility to adverse long-term outcomes following HI. Lower basal GSH levels, lower post-hypoxic mitochondrial glutathione peroxidase (mtGPx) activity, and mitochondrial glutathione peroxidase 4 (mtGPx4) protein levels may contribute to the susceptibility of the male brain to oxidative damage and mitochondrial dysfunction following neonatal hypoxic-ischemia (HI). Treatment of male pups with acetyl-L-carnitine (ALCAR) protects against the loss of mtGPx activity, mtGPx4 protein, and increases in protein

  5. Excitotoxic mitochondrial depolarisation requires both calcium and nitric oxide in rat hippocampal neurons

    PubMed Central

    Keelan, Julie; Vergun, Olga; Duchen, Michael R

    1999-01-01

    Glutamate neurotoxicity has been attributed to cellular Ca2+ overload. As mitochondrial depolarisation may represent a pivotal step in the progression to cell death, we have used digital imaging techniques to examine the relationship between cytosolic Ca2+ concentration ([Ca2+]c) and mitochondrial potential (ΔΨm) during glutamate toxicity, and to define the mechanisms underlying mitochondrial dysfunction. In cells of > 11 days in vitro (DIV), exposure to 50 mM potassium or 100 μM glutamate had different consequences for ΔΨm. KCl caused a small transient loss of ΔΨm but in response to glutamate there was a profound loss of ΔΨm. In cells of 7–10 DIV, glutamate caused only a modest and reversible drop in ΔΨm. Using fura-2 to measure [Ca2+]c, responses to KCl and glutamate did not appear significantly different. However, use of the low affinity indicator fura-2FF revealed a difference in the [Ca2+]c responses to KCl and glutamate, which clearly correlated with the loss of ΔΨm. Neurons exhibiting a profound mitochondrial depolarisation also showed a large secondary increase in the fura-2FF ratio. The glutamate-induced loss of ΔΨm was dependent on Ca2+ influx. However, inhibition of nitric oxide synthase (NOS) by L-NAME significantly attenuated the loss of ΔΨm. Furthermore, photolysis of caged NO at levels that had no effect alone promoted a profound mitochondrial depolarisation when combined with high [Ca2+]c, either in response to KCl or to glutamate in cultures at 7–10 DIV. In cells that showed only modest mitochondrial responses to glutamate, induction of a mitochondrial depolarisation by the addition of NO was followed by a secondary rise in [Ca2+]c. These data suggest that [Ca2+]c and nitric oxide act synergistically to cause mitochondrial dysfunction and impaired [Ca2+]c homeostasis during glutamate toxicity. PMID:10545145

  6. Mitochondrial oxidative stress-induced hepatocyte apoptosis reflects increased molybdenum intake in caprine.

    PubMed

    Zhuang, Yu; Liu, Ping; Wang, Liqi; Luo, Junrong; Zhang, Caiying; Guo, Xiaoquan; Hu, Guoliang; Cao, Huabin

    2016-03-01

    Molybdenum (Mo) is an essential trace element for animals and humans. However, the high dietary intake of Mo leads to disease conditions in heavy metal pollution areas. To the best of our knowledge, the effect of high levels of Mo on the apoptosis of hepatocyte in goats has not been investigated. Therefore, the aim of the present in vivo study was to investigate the impact of Mo on mitochondrial oxidative stress and apoptosis genes in the liver using real-time quantitative polymerase chain reaction (RT-qPCR) and transmission electron microscopy, respectively. Thirty-six healthy goats were randomly divided into three groups: two groups treated with ammonium molybdate [(NH4)6·Mo7O24·H2O] at 15 and 45 mg Mo kg(-1) BW, respectively, and a control group without treatment. Liver samples were collected from individual goats at different time intervals. The levels of oxidative stress in the mitochondrial membrane and expression of liver-related apoptosis genes, including Bcl-2, Cyt c, caspase-3, and Smac, were examined. The results demonstrated that the levels of superoxide dismutase (SOD) and catalase (CAT) expression were significantly down-regulated in liver cells, whereas malondialdehyde (MDA), nitric oxide (NO), and total nitric oxide synthase (T-NOS) expression was up-regulated (P < 0.01). The expression of Smac, Cyt c, and caspase-3 was significantly up-regulated, whereas Bcl-2 expression was down-regulated in liver cells (P < 0.01). In addition, histopathological examination revealed varying degrees of vacuolization, irregularity, nuclear fission, and mitochondrial swelling and high-density electrons in the cytoplasm of hepatocytes in groups treated with 15 and 45 mg Mo kg(-1) BW. Thus, these results suggested that high molybdenum induced hepatocyte apoptosis and might involve a mitochondrial pathway.

  7. The mitochondrial uncoupling agent 2,4-dinitrophenol improves mitochondrial function, attenuates oxidative damage, and increases white matter sparing in the contused spinal cord.

    PubMed

    Jin, Ying; McEwen, Melanie L; Nottingham, Stephanie A; Maragos, William F; Dragicevic, Natasha B; Sullivan, Patrick G; Springer, Joe E

    2004-10-01

    The purpose of this study was to investigate the potential neuroprotective efficacy of the mitochondrial uncoupler 2,4-dinitrophenol (DNP) in rats following a mild to moderate spinal cord contusion injury. Animals received intraperitoneal injections of vehicle (DMSO) or 5 mg/mL of DNP prior to injury. Twenty-four hours following surgery, mitochondrial function was assessed in mitochondria isolated from spinal cord synaptosomes. In addition, synaptosomes were used to measure indicators of reactive oxygen species formation, lipid peroxidation, and protein oxidation. Relative to vehicle-treated animals, pretreatment with DNP maintained mitochondrial bioenergetics and significantly decreased reactive oxygen species levels, lipid peroxidation, and protein carbonyl content following spinal cord injury. Furthermore, pretreatment with DNP significantly increased the amount of remaining white matter at the injury epicenter 6 weeks after injury. These results indicate that treatment with mitochondrial uncoupling agents may provide a novel approach for the treatment of secondary injury following spinal cord contusion.

  8. Cisplatin upregulates mitochondrial nitric oxide synthase and peroxynitrite formation to promote renal injury.

    PubMed

    Jung, Michaela; Hotter, Georgina; Viñas, Jose Luis; Sola, Anna

    2009-01-15

    The mitochondria are a critical target for cisplatin-associated nephrotoxicity. Though nitric oxide formation has been implicated in the toxicity of cisplatin, this formation has not so far been related to a possible activation of mitochondrial nitric oxide synthase (mNOS). We show here that the upregulation of oxide mNOS and peroxynitrite formation in cisplatin treatment are key events that influence the development of the harmful parameters described in cisplatin-associated kidney failure. We confirm this by isolating the mitochondrial fraction of the kidney and across different access routes such as the use of a specific inhibitor of neuronal NOS, L-NPA, a peroxynitrite scavenger, FeTMPyP, and a peroxynitrite donor, SIN-1. The in vitro studies corroborated the information obtained in the in vivo experiments. The administration of cisplatin reveals a clear upregulation in the transcription of neuronal NOS and an increase in the levels of nitrites in the mitochondrial fractions of the kidneys. The upregulated transcription directly affects the cytoskeleton structure and the apoptosis. The inhibition of neuronal NOS reduces the levels of nitrites, cell death, and cytoskeleton derangement. Peroxynitrite is involved in the mechanism promoting the NOS transcription. In addition, in controls SIN-1 imitates the effects of cisplatin. In summary, we demonstrate that upregulation of mNOS in cisplatin treatment is a key component in both the initiation and the spread of cisplatin-associated damage in the kidney. Furthermore, peroxynitrite formation is directly involved in this process.

  9. Cisplatin upregulates mitochondrial nitric oxide synthase and peroxynitrite formation to promote renal injury

    SciTech Connect

    Jung, Michaela; Sola, Anna

    2009-01-15

    The mitochondria are a critical target for cisplatin-associated nephrotoxicity. Though nitric oxide formation has been implicated in the toxicity of cisplatin, this formation has not so far been related to a possible activation of mitochondrial nitric oxide synthase (mNOS). We show here that the upregulation of oxide mNOS and peroxynitrite formation in cisplatin treatment are key events that influence the development of the harmful parameters described in cisplatin-associated kidney failure. We confirm this by isolating the mitochondrial fraction of the kidney and across different access routes such as the use of a specific inhibitor of neuronal NOS, L-NPA, a peroxynitrite scavenger, FeTMPyP, and a peroxynitrite donor, SIN-1. The in vitro studies corroborated the information obtained in the in vivo experiments. The administration of cisplatin reveals a clear upregulation in the transcription of neuronal NOS and an increase in the levels of nitrites in the mitochondrial fractions of the kidneys. The upregulated transcription directly affects the cytoskeleton structure and the apoptosis. The inhibition of neuronal NOS reduces the levels of nitrites, cell death, and cytoskeleton derangement. Peroxynitrite is involved in the mechanism promoting the NOS transcription. In addition, in controls SIN-1 imitates the effects of cisplatin. In summary, we demonstrate that upregulation of mNOS in cisplatin treatment is a key component in both the initiation and the spread of cisplatin-associated damage in the kidney. Furthermore, peroxynitrite formation is directly involved in this process.

  10. Isolongifolene attenuates rotenone-induced mitochondrial dysfunction, oxidative stress and apoptosis.

    PubMed

    Balakrishnan, Rengasamy; Elangovan, Namasivayam; Mohankumar, Thangavel; Nataraj, Jegadeesan; Manivasagam, Thamilarasan; Justin Thenmozhi, Arokiasamy; Mohamed Essa, Musthafa; Akbar, Mohammed; Abdul Sattar Khan, Mohammed

    2018-01-01

    The present study was carried out to investigate the neuroprotective effects of isolongifolene (ILF), a tricyclic sesquiterpene of Murraya koenigii, against rotenone-induced mitochondrial dysfunction, oxidative stress and apoptosis in a cellular model. SH-SY5Y human neuroblastoma cells were divided into four experimental groups (control, rotenone (100 nM), ILF (10 microM) + rotenone (100 nanoM), ILF 10 microM alone treated) based on 3-(4, 5-dimethyl 2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. The results of the present study showed that the ILF treatment significantly alleviated rotenone-induced cytotoxicity, oxidative stress and mitochondrial dysfunction in SH-SY5Y cells. Moreover, ILF attenuated rotenone induced toxicity by down-regulating  Bax, caspases-3, 6, 8 and 9 expression and up-regulating of Bcl-2 expression. Furthermore regulation of p-P13K, p-AKT and p-GSK-3 beta expression by ILF, clearly confirmed its protective effects. Taken together, our results suggested that ILF attenuated rotenone-induced oxidative stress, mitochondrial dysfunction and apoptosis through the regulation of P13K/AKT/GSK-3 beta signaling pathways. However further pre-clinical studies are warranted in rodents to use ILF as a promising therapeutic agent for PD in future.

  11. Infertility and recurrent miscarriage with complex II deficiency-dependent mitochondrial oxidative stress in animal models.

    PubMed

    Ishii, Takamasa; Yasuda, Kayo; Miyazawa, Masaki; Mitsushita, Junji; Johnson, Thomas E; Hartman, Phil S; Ishii, Naoaki

    2016-04-01

    Oxidative stress is associated with some forms of both male and female infertility. However, there is insufficient knowledge of the influence of oxidative stress on the maintenance of a viable pregnancy, including pregnancy complications and fetal development. There are a number of animal models for understanding age-dependent decrease of reproductive ability and diabetic embryopathy, especially abnormal spermatogenesis, oogenesis and embryogenesis with mitochondrial dysfunctions. Several important processes occur in mitochondria, including ATP synthesis, calcium ion storage, induction of apoptosis and production of reactive oxygen species (ROS). These events have different effects on the several aspects of reproductive function. Tet-mev-1 conditional transgenic mice, developed after studies with the mev-1 mutant of the nematode C. elegans, offer the ability to carefully regulate expression of doxycycline-induced mutated SDHC(V69E) levels and hence modulate endogenous oxidative stress. The mev-1 models have served to illuminate the effects of complex II deficiency-dependent mitochondrial ROS production, although interestingly they maintain normal mitochondrial and intracellular ATP levels. In this review, the reproductive dysfunctions are presented focusing on fertility potentials in each gamete, early embryogenesis, maternal conditions with placental function and neonatal development.

  12. IRS2 increases mitochondrial dysfunction and oxidative stress in a mouse model of Huntington disease.

    PubMed

    Sadagurski, Marianna; Cheng, Zhiyong; Rozzo, Aldo; Palazzolo, Isabella; Kelley, Gregory R; Dong, Xiaocheng; Krainc, Dimitri; White, Morris F

    2011-10-01

    Aging is a major risk factor for the progression of neurodegenerative diseases, including Huntington disease (HD). Reduced neuronal IGF1 or Irs2 signaling have been shown to extend life span in mice. To determine whether Irs2 signaling modulates neurodegeneration in HD, we genetically modulated Irs2 concentrations in the R6/2 mouse model of HD. Increasing Irs2 levels in the brains of R6/2 mice significantly reduced life span and increased neuronal oxidative stress and mitochondrial dysfunction. In contrast, reducing Irs2 levels throughout the body (except in β cells, where Irs2 expression is needed to prevent diabetes onset; R6/2•Irs2+/-•Irs2βtg mice) improved motor performance and extended life span. The slower progression of HD-like symptoms was associated with increased nuclear localization of the transcription factor FoxO1 and increased expression of FoxO1-dependent genes that promote autophagy, mitochondrial function, and resistance to oxidative stress. Mitochondrial function improved and the number of autophagosomes increased in R6/2•Irs2+/-•Irs2βtg mice, whereas aggregate formation and oxidative stress decreased. Thus, our study suggests that Irs2 signaling can modulate HD progression. Since we found the expression of Irs2 to be normal in grade II HD patients, our results suggest that decreasing IRS2 signaling could be part of a therapeutic approach to slow the progression of HD.

  13. Antioxidant properties of Neu2000 on mitochondrial free radicals and oxidative damage.

    PubMed

    Visavadiya, Nishant P; McEwen, Melanie L; Pandya, Jignesh D; Sullivan, Patrick G; Gwag, Byoung Joo; Springer, Joe E

    2013-03-01

    Neu2000 [2-hydroxy-5-(2,3,5,6-tetrafluoro-4 trifluoromethylbenzylamino) benzoic acid] is a dual-acting neuroprotective agent that functions both as a noncompetitive N-methyl-d-aspartate (NMDA) receptor antagonist and a free radical scavenger. In the present study, we investigated the scavenging activity of Neu2000 on various classes of reactive oxygen species and reactive nitrogen species (ROS/RNS) as well as its efficacy for reducing free radicals and oxidative stress/damage induced in spinal cord mitochondrial preparations. Neu2000 exerted scavenging activity against superoxide, nitric oxide, and hydroxyl radicals, and efficiently scavenged peroxynitrite. In the mitochondrial studies, Neu2000 markedly inhibited ROS/RNS and hydrogen peroxide levels following antimycin treatment. In addition, Neu2000 effectively scavenged hydroxyl radicals generated by iron(III)-ascorbate, reduced protein carbonyl formation mediated by hydroxyl radicals and peroxynitrite, and prevented glutathione oxidation caused by tert-butyl hydroperoxide in isolated mitochondria. Interestingly, incubation of isolated mitochondria with Neu2000 followed by centrifugation and removal of the supernatant also resulted in a concentration-dependent decrease in lipid peroxidation. This observation suggests that Neu2000 enters mitochondria to target free radicals or indirectly affects mitochondrial function in a manner that promotes antioxidant activity. The results of the present study demonstrate that Neu2000 possesses potent in vitro antioxidant activity due, most likely, to its active phenoxy group.

  14. Assembly defects induce oxidative stress in inherited mitochondrial complex I deficiency.

    PubMed

    Leman, Géraldine; Gueguen, Naïg; Desquiret-Dumas, Valérie; Kane, Mariame Selma; Wettervald, Céline; Chupin, Stéphanie; Chevrollier, Arnaud; Lebre, Anne-Sophie; Bonnefont, Jean-Paul; Barth, Magalie; Amati-Bonneau, Patrizia; Verny, Christophe; Henrion, Daniel; Bonneau, Dominique; Reynier, Pascal; Procaccio, Vincent

    2015-08-01

    Complex I (CI) deficiency is the most common respiratory chain defect representing more than 30% of mitochondrial diseases. CI is an L-shaped multi-subunit complex with a peripheral arm protruding into the mitochondrial matrix and a membrane arm. CI sequentially assembled into main assembly intermediates: the P (pumping), Q (Quinone) and N (NADH dehydrogenase) modules. In this study, we analyzed 11 fibroblast cell lines derived from patients with inherited CI deficiency resulting from mutations in the nuclear or mitochondrial DNA and impacting these different modules. In patient cells carrying a mutation located in the matrix arm of CI, blue native-polyacrylamide gel electrophoresis (BN-PAGE) revealed a significant reduction of fully assembled CI enzyme and an accumulation of intermediates of the N module. In these cell lines with an assembly defect, NADH dehydrogenase activity was partly functional, even though CI was not fully assembled. We further demonstrated that this functional N module was responsible for ROS production through the reduced flavin mononucleotide. Due to the assembly defect, the FMN site was not re-oxidized leading to a significant oxidative stress in cell lines with an assembly defect. These findings not only highlight the relationship between CI assembly and oxidative stress, but also show the suitability of BN-PAGE analysis in evaluating the consequences of CI dysfunction. Moreover, these data suggest that the use of antioxidants may be particularly relevant for patients displaying a CI assembly defect. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Modulation of mitochondrial gene expression in pulmonary epithelial cells exposed to oxidants.

    PubMed Central

    Janssen, Y M; Driscoll, K E; Timblin, C R; Hassenbein, D; Mossman, B T

    1998-01-01

    Oxidants are important in the regulation of signal transduction and gene expression. Multiple classes of genes are transcriptionally activated by oxidants and are implicated in different phenotypic responses. In the present study, we performed differential mRNA display to elucidate genes that are induced or repressed after exposure of rat lung epithelial (RLE) cells to H2O2 or crocidolite asbestos, a pathogenic mineral that generates oxidants. After 8 or 24 hr of exposure, RNA was extracted, reverse transcribed, and amplified by polymerase chain reaction with degenerate primers to visualize alterations in gene expression. The seven clones obtained were sequenced and encoded the mitochondrial genes, NADH dehydrogenase subunits ND5 and ND6, and 16S ribosomal RNA. Evaluation of their expression by Northern blot analysis revealed increased expression of 16S rRNA after 1 or 2 hr of exposure to H2O2. At later time periods (4 and 24 hr), mRNA levels of 16S rRNA and NADH dehydrogenase were decreased in H2O2-treated RLE cells when compared to sham controls. Crocidolite asbestos caused increases in 16S rRNA levels after 8 hr of exposure, whereas after 24 hr of exposure to asbestos, 16S rRNA levels were decreased in comparison to sham controls. In addition to these oxidants, the nitric oxide generator spermine NONOate caused similar decreases in NADH dehydrogenase mRNA levels after 4 hr of exposure. The present data and previous studies demonstrated that all oxidants examined resulted in apoptosis in RLE cells during the time frame where alterations of mitochondrial gene expression were observed. As the mitochondrion is a major organelle that controls apoptosis, alterations in expression of mitochondrial genes may be involved in the regulation of apoptosis. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 PMID:9788897

  16. Dietary fish oil promotes colonic apoptosis and mitochondrial proton leak in oxidatively stressed mice.

    PubMed

    Fan, Yang-Yi; Ran, Qitao; Toyokuni, Shinya; Okazaki, Yasumasa; Callaway, Evelyn S; Lupton, Joanne R; Chapkin, Robert S

    2011-08-01

    An alteration of mitochondrial function can result in disruption of redox homeostasis and is associated with abnormal cancer cell growth. Manganese superoxide dismutase (SOD2) and glutathione peroxidase 4 (Gpx4) are two of the most important antioxidant defense enzymes that protect cells against oxidative stress. We had previously shown that n-3 polyunsaturated fatty acids (PUFA) promote colonocyte apoptosis, a marker of colon cancer risk, in part by enhancing phospholipid oxidation. To elucidate the mechanisms regulating oxidative stress-induced apoptosis in vivo, we fed heterozygous SOD2(Het), Gpx4(Het), and transgenic Gpx4(Tg) mice diets containing either 15% corn oil by weight (CO, enriched in n-6 PUFA) or 3.5% CO + 11.5% fish oil (FO, enriched in n-3 PUFA) for 4 weeks. Our data showed that (i) genetic predeposition to oxidative stress facilitates apoptosis in the mouse colon (Gpx4(Het) > SOD2(Het) > Wt > Gpx4(Tg)), (ii) dietary n-3 PUFA have an additive effect on the induction of apoptosis in Gpx4(Het) and SOD2(Het) mice; and (iii) dietary n-3 PUFA reverse the phenotype in oxidatively protected Gpx4(Tg) mice by elevating apoptosis to a level observed in wild-type (Wt; control) animals. Complimentary experiments examining colonic mitochondrial bioenergetic profiles indicate that FO-fed mice exhibit a significantly (P < 0.05) increased respiration-induced proton leak relative to control CO treatment. This finding was consistent with a loss of membrane potential in response to chronic oxidative stress and supports the contention that n-3 PUFA alter mitochondrial metabolic activity, thereby enhancing apoptosis and reducing colon cancer risk.

  17. Status Epilepticus in Immature Rats Is Associated with Oxidative Stress and Mitochondrial Dysfunction

    PubMed Central

    Folbergrová, Jaroslava; Ješina, Pavel; Kubová, Hana; Druga, Rastislav; Otáhal, Jakub

    2016-01-01

    Epilepsy is a neurologic disorder, particularly frequent in infants and children where it can lead to serious consequences later in life. Oxidative stress and mitochondrial dysfunction are implicated in the pathogenesis of many neurological disorders including epilepsy in adults. However, their role in immature epileptic brain is unclear since there have been two contrary opinions: oxidative stress is age-dependent and does not occur in immature brain during status epilepticus (SE) and, on the other hand, evidence of oxidative stress in immature brain during a specific model of SE. To solve this dilemma, we have decided to investigate oxidative stress following SE induced in immature 12-day-old rats by three substances with a different mechanism of action, namely 4-aminopyridine, LiCl-pilocarpine or kainic acid. Fluoro-Jade-B staining revealed mild brain damage especially in hippocampus and thalamus in each of the tested models. Decrease of glucose and glycogen with parallel rises of lactate clearly indicate high rate of glycolysis, which was apparently not sufficient in 4-AP and Li-Pilo status, as evident from the decreases of PCr levels. Hydroethidium method revealed significantly higher levels of superoxide anion (by ∼60%) in the hippocampus, cerebral cortex and thalamus of immature rats during status. SE lead to mitochondrial dysfunction with a specific pronounced decrease of complex I activity that persisted for a long period of survival. Complexes II and IV activities remained in the control range. Antioxidant treatment with SOD mimetic MnTMPYP or peroxynitrite scavenger FeTPPS significantly attenuated oxidative stress and inhibition of complex I activity. These findings bring evidence that oxidative stress and mitochondrial dysfunction are age and model independent, and may thus be considered a general phenomenon. They can have a clinical relevance for a novel approach to the treatment of epilepsy, allowing to target the mechanisms which play a crucial or

  18. p-Bromophenacyl bromide prevents cumene hydroperoxide-induced mitochondrial permeability transition by inhibiting pyridine nucleotide oxidation.

    PubMed

    Zhukova, A; Gogvadze, G; Gogvadze, V

    2004-01-01

    Mitochondrial permeability transition is commonly characterized as a Ca2+ -dependent non-specific increase in inner membrane permeability that results in swelling of mitochondria and their de-energization. In the present study, the effect of different inhibitors of phospholipase A2--p-bromophenacyl bromide, dibucaine, and aristolochic acid--on hydroperoxide-induced permeability transitions in rat liver mitochondria was tested. p-Bromophenacyl bromide completely prevented the hydroperoxide-induced mitochondrial permeability transition while the effects of dibucaine or aristolochic acid were negligible. Organic hydroperoxides added to mitochondria undergo reduction to corresponding alcohols by mitochondrial glutathione peroxidase. This reduction occurs at the expense of GSH which, in turn, can be reduced by glutathione reductase via oxidation of mitochondrial pyridine nucleotides. The latter is considered a prerequisite step for mitochondrial permeability transition. Among all the inhibitors tested, only p-bromophenacyl bromide completely prevented hydroperoxide-induced oxidation of mitochondrial pyridine nucleotides. Interestingly, p-bromophenacyl bromide had no affect on mitochondrial glutathione peroxidase, but reacted with mitochondrial glutathione that prevented pyridine nucleotides from being oxidized. Our data suggest that p-bromophenacyl bromide prevents hydroperoxide-induced deterioration of mitochondria via interaction with glutathione rather than through inhibition of phospholipase A2.

  19. Brain imaging for oxidative stress and mitochondrial dysfunction in neurodegenerative diseases.

    PubMed

    Okazawa, H; Ikawa, M; Tsujikawa, T; Kiyono, Y; Yoneda, M

    2014-12-01

    Oxidative stress, one of the most probable molecular mechanisms for neuronal impairment, is reported to occur in the affected brain regions of various neurodegenerative diseases. Recently, many studies showed evidence of a link between oxidative stress or mitochondrial damage and neuronal degeneration. Basic in vitro experiments and postmortem studies demonstrated that biomarkers for oxidative damage can be observed in the pathogenic regions of the brain and the affected neurons. Model animal studies also showed oxidative damage associated with neuronal degeneration. The molecular imaging method with positron emission tomography (PET) is expected to delineate oxidatively stressed microenvironments to elucidate pathophysiological changes of the in vivo brain; however, only a few studies have successfully demonstrated enhanced stress in patients. Radioisotope copper labeled diacetyl-bis(N4-methylthiosemicarbazone) (Cu-ATSM) may be the most promising candidate for this oxidative stress imaging. The tracer is usually known as a hypoxic tissue imaging PET probe, but the accumulation mechanism is based on the electron rich environment induced by mitochondrial impairment and/or microsomal over-reduction, and thus it is considered to represent the oxidative stress state correlated with the degree of disease severity. In this review, Cu-ATSM PET is introduced in detail from the basics to practical methods in clinical studies, as well as recent clinical studies on cerebrovascular diseases and neurodegenerative diseases. Several other PET probes are also introduced from the point of view of neuronal oxidative stress imaging. These molecular imaging methods should be promising tools to reveal oxidative injuries in various brain diseases.

  20. Prevention of oxidative stress, inflammation and mitochondrial dysfunction in the intestine by different cranberry phenolic fractions.

    PubMed

    Denis, Marie-Claude; Desjardins, Yves; Furtos, Alexandra; Marcil, Valérie; Dudonné, Stéphanie; Montoudis, Alain; Garofalo, Carole; Delvin, Edgard; Marette, André; Levy, Emile

    2015-02-01

    Cranberry fruit has been reported to have high antioxidant effectiveness that is potentially linked to its richness in diversified polyphenolic content. The aim of the present study was to determine the role of cranberry polyphenolic fractions in oxidative stress (OxS), inflammation and mitochondrial functions using intestinal Caco-2/15 cells. The combination of HPLC and UltraPerformance LC®-tandem quadrupole (UPLC-TQD) techniques allowed us to characterize the profile of low, medium and high molecular mass polyphenolic compounds in cranberry extracts. The medium molecular mass fraction was enriched with flavonoids and procyanidin dimers whereas procyanidin oligomers (DP > 4) were the dominant class of polyphenols in the high molecular mass fraction. Pre-incubation of Caco-2/15 cells with these cranberry extracts prevented iron/ascorbate-mediated lipid peroxidation and counteracted lipopolysaccharide-mediated inflammation as evidenced by the decrease in pro-inflammatory cytokines (TNF-α and interleukin-6), cyclo-oxygenase-2 and prostaglandin E2. Cranberry polyphenols (CP) fractions limited both nuclear factor κB activation and Nrf2 down-regulation. Consistently, cranberry procyanidins alleviated OxS-dependent mitochondrial dysfunctions as shown by the rise in ATP production and the up-regulation of Bcl-2, as well as the decline of protein expression of cytochrome c and apoptotic-inducing factor. These mitochondrial effects were associated with a significant stimulation of peroxisome-proliferator-activated receptor γ co-activator-1-α, a central inducing factor of mitochondrial biogenesis and transcriptional co-activator of numerous downstream mediators. Finally, cranberry procyanidins forestalled the effect of iron/ascorbate on the protein expression of mitochondrial transcription factors (mtTFA, mtTFB1, mtTFB2). Our findings provide evidence for the capacity of CP to reduce intestinal OxS and inflammation while improving mitochondrial dysfunction.

  1. Effect of nitric oxide on mitochondrial respiratory activity of human articular chondrocytes

    PubMed Central

    Maneiro, E; Lopez-Armada, M; de Andres, M C; Carames, B; Martin, M; Bonilla, A; del Hoyo, P; Galdo, F; Arenas, J; Blanco, F

    2005-01-01

    Objective: To investigate the effect of nitric oxide (NO) on mitochondrial activity and its relation with the apoptosis of human articular chondrocytes. Materials and methods: Mitochondrial function was evaluated by analysing respiratory chain enzyme complexes, citrate synthase (CS) activities, and mitochondrial membrane potential (Δψm). The activities of the mitochondrial respiratory chain (MRC) complexes (complex I: NADH CoQ1 reductase, complex II: succinate dehydrogenase, complex III: ubiquinol cytochrome c reductase, complex IV: cytochrome c oxidase) and CS were measured in human articular chondrocytes isolated from normal cartilage. The Δψm was measured by 5,5',6,6'-tetracholoro-1,1',3,3'-tetraethylbenzimidazole carbocyanide iodide (JC-1) using flow cytometry. Apoptosis was analysed by flow cytometry. The mRNA expression of caspases was analysed by ribonuclease protection analysis and the detection of protein synthesis by western blotting. Sodium nitroprusside (SNP) was used as an NO compound donor. Results: SNP at concentrations higher than 0.5 mmol/l for 24 hours induced cellular changes characteristic of apoptosis. SNP elicited mRNA expression of caspase-3 and caspase-7 and down regulated bcl-2 synthesis in a dose and time dependent manner. Furthermore, 0.5 mM SNP induced depolarisation of the mitochondrial membrane at 5, 12, and 24 hours. Analysis of the MRC showed that at 5 hours, 0.5 mM SNP reduced the activity of complex IV by 33%. The individual inhibition of mitochondrial complex IV with azide modified the Δψm and induced apoptosis. Conclusions: This study suggests that the effect of NO on chondrocyte survival is mediated by its effect on complex IV of the MRC. PMID:15708893

  2. Oxidative stress in skeletal muscle impairs mitochondrial respiration and limits exercise capacity in type 2 diabetic mice.

    PubMed

    Yokota, Takashi; Kinugawa, Shintaro; Hirabayashi, Kagami; Matsushima, Shouji; Inoue, Naoki; Ohta, Yukihiro; Hamaguchi, Sanae; Sobirin, Mochamad A; Ono, Taisuke; Suga, Tadashi; Kuroda, Satoshi; Tanaka, Shinya; Terasaki, Fumio; Okita, Koichi; Tsutsui, Hiroyuki

    2009-09-01

    Insulin resistance or diabetes is associated with limited exercise capacity, which can be caused by the abnormal energy metabolism in skeletal muscle. Oxidative stress is involved in mitochondrial dysfunction in diabetes. We hypothesized that increased oxidative stress could cause mitochondrial dysfunction in skeletal muscle and make contribution to exercise intolerance in diabetes. C57/BL6J mice were fed on normal diet or high fat diet (HFD) for 8 wk to induce obesity with insulin resistance and diabetes. Treadmill tests with expired gas analysis were performed to determine the exercise capacity and whole body oxygen uptake (Vo(2)). The work (vertical distance x body weight) to exhaustion was reduced in the HFD mice by 36%, accompanied by a 16% decrease of peak Vo(2). Mitochondrial ADP-stimulated respiration, electron transport chain complex I and III activities, and mitochondrial content in skeletal muscle were decreased in the HFD mice. Furthermore, superoxide production and NAD(P)H oxidase activity in skeletal muscle were significantly increased in the HFD mice. Intriguingly, the treatment of HFD-fed mice with apocynin [10 mmol/l; an inhibitor of NAD(P)H oxidase activation] improved exercise intolerance and mitochondrial dysfunction in skeletal muscle without affecting glucose metabolism itself. The exercise capacity and mitochondrial function in skeletal muscle were impaired in type 2 diabetes, which might be due to enhanced oxidative stress. Therapies designed to regulate oxidative stress and maintain mitochondrial function could be beneficial to improve the exercise capacity in type 2 diabetes.

  3. Naringin protects memory impairment and mitochondrial oxidative damage against aluminum-induced neurotoxicity in rats.

    PubMed

    Prakash, Atish; Shur, Bhargabi; Kumar, Anil

    2013-09-01

    Aluminum has been indicated in neurodegenerative disorders and naringin, a bioflavonoid has been used to reduce neurotoxic effects of aluminum against aluminum chloride-induced rats. Therefore, present study has been designed to explore the possible role of naringin against aluminum-induced cognitive dysfunction and oxidative damage in rats. Aluminum (100 mg/kg) and naringin (40 and 80 mg/kg) drug treatment were administered orally for six weeks to male wistar rats. Various behavioral performance tasks, biochemical, mitochondrial oxidative parameters, and aluminum concentration in the brain were assessed. Aluminum chloride treatment significantly caused cognitive dysfunction and mitochondria oxidative damage as compared to vehicle treated control group. Besides, aluminum chloride treatment significantly increased acetyl cholinesterase activity and aluminum concentration in the brain as compared to sham. Chronic administration of naringin significantly improved cognitive performance and attenuated mitochondria oxidative damage, acetyl cholinesterase activity, and aluminum concentration in aluminum-treated rats as compared to control rats. Results of the study demonstrate neuroprotective potential of naringin against aluminum chloride-induced cognitive dysfunction and mitochondrial oxidative damage.

  4. The interplay between inflammation, oxidative stress, DNA damage, DNA repair and mitochondrial dysfunction in depression.

    PubMed

    Czarny, Piotr; Wigner, Paulina; Galecki, Piotr; Sliwinski, Tomasz

    2017-06-29

    A growing body of evidence suggests that inflammation, mitochondrial dysfunction and oxidant-antioxidant imbalance may play a significant role in the development and progression of depression. Elevated levels of reactive oxygen and nitrogen species - a result of oxidant-antioxidant imbalance - may lead to increased damage of biomolecules, including DNA. This was confirmed in depressed patients in a research study conducted by our team and other scientists. 8-oxoguanine - a marker of oxidative DNA damage - was found in the patients' lymphocytes, urine and serum. These results were confirmed using a comet assay on lymphocytes. Furthermore, it was shown that the patients' cells repaired peroxide-induced DNA damage less efficiently than controls' cells and that some single nucleotide polymorphisms (SNP) of the genes involved in oxidative DNA damage repair may modulate the risk of depression. Lastly, less efficient DNA damage repair observed in the patients can be, at least partly, attributed to the presence of specific SNP variants, as it was revealed through a genotype-phenotype analysis. In conclusion, the available literature shows that both oxidative stress and less efficient DNA damage repair may lead to increased DNA damage in depressed patients. A similar mechanism may result in mitochondrial dysfunction, which is observed in depression. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Hyperactivation of oxidative mitochondrial metabolism in epithelial cancer cells in situ

    PubMed Central

    Whitaker-Menezes, Diana; Martinez-Outschoorn, Ubaldo E; Flomenberg, Neal; Birbe, Ruth C; Witkiewicz, Agnieszka K; Howell, Anthony; Pavlides, Stephanos; Tsirigos, Aristotelis; Ertel, Adam; Pestell, Richard G; Broda, Paolo; Minetti, Carlo

    2011-01-01

    We have recently proposed a new mechanism for explaining energy transfer in cancer metabolism. In this scenario, cancer cells behave as metabolic parasites, by extracting nutrients from normal host cells, such as fibroblasts, via the secretion of hydrogen peroxide as the initial trigger. Oxidative stress in the tumor microenvironment then leads to autophagy-driven catabolism, mitochondrial dys-function and aerobic glycolysis. This, in turn, produces high-energy nutrients (such as L-lactate, ketones and glutamine) that drive the anabolic growth of tumor cells, via oxidative mitochondrial metabolism. A logical prediction of this new “parasitic” cancer model is that tumor-associated fibroblasts should show evidence of mitochondrial dys-function (mitophagy and aerobic glycolysis). In contrast, epithelial cancer cells should increase their oxidative mitochondrial capacity. To further test this hypothesis, here we subjected frozen sections from human breast tumors to a staining procedure that only detects functional mitochondria. This method detects the in situ enzymatic activity of cytochrome C oxidase (COX), also known as Complex IV. Remarkably, cancer cells show an over-abundance of COX activity, while adjacent stromal cells remain essentially negative. Adjacent normal ductal epithelial cells also show little or no COX activity, relative to epithelial cancer cells. Thus, oxidative mitochondrial activity is selectively amplified in cancer cells. Although COX activity staining has never been applied to cancer tissues, it could now be used routinely to distinguish cancer cells from normal cells, and to establish negative margins during cancer surgery. Similar results were obtained with NADH activity staining, which measures Complex I activity, and succinate dehydrogenase (SDH) activity staining, which measures Complex II activity. COX and NADH activities were blocked by electron transport inhibitors, such as Metformin. This has mechanistic and clinical implications

  6. Overproduction of nitric oxide by endothelial cells and macrophages contributes to mitochondrial oxidative stress in adrenocortical cells and adrenal insufficiency during endotoxemia.

    PubMed

    Wang, Chang-Nan; Duan, Guo-Li; Liu, Yu-Jian; Yu, Qing; Tang, Xiao-Lu; Zhao, Wei; Li, Xiao-Han; Zhu, Xiao-Yan; Ni, Xin

    2015-06-01

    We have recently demonstrated that lipopolysaccharide (LPS) causes mitochondrial oxidative stress and dysfunction in adrenal glands, thereby leading to adrenocortical insufficiency. Since nitric oxide (NO) produced by inducible nitric oxide synthase (iNOS) leads to mitochondrial damage in various tissues, the present study aims to investigate whether NO contributes to mitochondrial oxidative stress in adrenal cortex and adrenocortical insufficiency during endotoxemia. Systemic administration of LPS increased iNOS expression and NO production in adrenal glands of mice. The specific iNOS inhibitor 1400 W significantly attenuated the LPS-induced mitochondrial superoxide production and dysfunction in adrenal glands, and reversed the LPS-induced adrenocortical hyporesponsiveness to adrenocorticotropic hormone (ACTH). In contrast, administration of the NO donor sodium nitroprusside (SNP) led to mitochondrial oxidative stress and dysfunction in adrenal glands, which resulted in a blunted corticosterone response to ACTH. Using double immunofluorescence staining for iNOS with the vascular endothelial cell marker CD31 or the macrophage marker CD68, we found that increased iNOS expression was found in vascular endothelial cells and macrophages, but not adrenocortical cells in the adrenal gland during endotoxemia. Administration of the hydrogen sulfide (H2S) donor GYY4137 inhibited NO production and reversed LPS-induced adrenocortical hyporesponsiveness. Our data suggest that overproduction of NO, which is mainly generated by endothelial cells and macrophages during endotoxemia, contributes to mitochondrial oxidative stress in adrenocortical cells and subsequently leads to adrenal insufficiency. Copyright © 2015 Elsevier Inc. All rights reserved.

  7. Some aspects of the mitochondrial oxidative metabolism in human atrial tissue during cardiopulmonary by-pass.

    PubMed

    Corbucci, G G; Gasparetto, A; Antonelli, M; Bufi, M; De Blasi, R A

    1987-01-01

    Following previous research on the hypoxic cell in human circulatory shock, the present work has investigated some mitochondrial oxidative aspects in atrial biopsies taken during cardiopulmonary by-pass. Cardioplegic solution and hypothermia were administered to 10 patients and the atrial samples were collected before and after aortic clamping. The results show a cellular protective effect of cardioplegia and hypothermia on the electron-transport chain, even if the enzymes with high KmO2 appear to be more sensitive to ischaemia. The results suggest a metabolic injury rather than an oxidative damage due to the induced ischaemia, alterations to fatty-acid beta-oxidation being especially notable. Because of the unchanged oxidative capacities, the oxyradical generation and the peroxidative damage appear to be irrelevant in the ischaemic period and during the course of reperfusion. Further studies are needed to elucidate the metabolic damage and the therapeutic implications due to the induced ischaemia in the myocardial cell during the aortic clamping.

  8. Methoxychlor causes mitochondrial dysfunction and oxidative damage in the mouse ovary

    SciTech Connect

    Gupta, R.K.; Schuh, R.A.; Fiskum, G.; Flaws, J.A. . E-mail: jflaws@epi.umaryland.edu

    2006-11-01

    Methoxychlor (MXC) is an organochlorine pesticide that reduces fertility in female rodents by causing ovarian atrophy, persistent estrous cyclicity, and antral follicle atresia (apoptotic cell death). Oxidative damage resulting from reactive oxygen species (ROS) generation has been demonstrated to lead to toxicant-induced cell death. Thus, this work tested the hypothesis that MXC causes oxidative damage to the mouse ovary and affects mitochondrial respiration in a manner that stimulates ROS production. For the in vitro experiments, mitochondria were collected from adult cycling mouse ovaries, treated with vehicle (dimethyl sulfoxide; DMSO) or MXC, and subjected to polarographic measurements of respiration. For the in vivo experiments, adult cycling CD-1 mice were dosed with either vehicle (sesame oil) or MXC for 20 days. After treatment, ovarian mitochondria were isolated and subjected to measurements of respiration and fluorimetric measurements of H{sub 2}O{sub 2} production. Some ovaries were also fixed and processed for immunohistochemistry using antibodies for ROS production markers: nitrotyrosine and 8-hydroxy-2'-deoxyguanosine (8-OHG). Ovaries from in vivo experiments were also used to measure the mRNA expression and activity of antioxidants such as Cu/Zn superoxide dismutase (SOD1), glutathione peroxidase (GPX), and catalase (CAT). The results indicate that MXC significantly impairs mitochondrial respiration, increases production of H{sub 2}O{sub 2}, causes more staining for nitrotyrosine and 8-OHG in antral follicles, and decreases the expression and activity of SOD1, GPX, and CAT as compared to controls. Collectively, these data indicate that MXC inhibits mitochondrial respiration, causes ROS production, and decreases antioxidant expression and activity in the ovary, specifically in the antral follicles. Therefore, it is possible that MXC causes atresia of ovarian antral follicles by inducing oxidative stress through mitochondrial production of ROS.

  9. Mitochondrial dysfunction and oxidative stress in patients with chronic kidney disease.

    PubMed

    Gamboa, Jorge L; Billings, Frederic T; Bojanowski, Matthew T; Gilliam, Laura A; Yu, Chang; Roshanravan, Baback; Roberts, L Jackson; Himmelfarb, Jonathan; Ikizler, T Alp; Brown, Nancy J

    2016-05-01

    Mitochondria abnormalities in skeletal muscle may contribute to frailty and sarcopenia, commonly present in patients with chronic kidney disease (CKD). Dysfunctional mitochondria are also a major source of oxidative stress and may contribute to cardiovascular disease in CKD We tested the hypothesis that mitochondrial structure and function worsens with the severity of CKD Mitochondrial volume density, mitochondrial DNA (mtDNA) copy number, BNIP3, and PGC1α protein expression were evaluated in skeletal muscle biopsies obtained from 27 subjects (17 controls and 10 with CKD stage 5 on hemodialysis). We also measured mtDNA copy number in peripheral blood mononuclear cells (PBMCs), plasma isofurans, and plasma F2-isoprostanes in 208 subjects divided into three groups: non-CKD (eGFR>60 mL/min), CKD stage 3-4 (eGFR 60-15 mL/min), and CKD stage 5 (on hemodialysis). Muscle biopsies from patients with CKD stage 5 revealed lower mitochondrial volume density, lower mtDNA copy number, and higher BNIP3 content than controls. mtDNA copy number in PBMCs was decreased with increasing severity of CKD: non-CKD (6.48, 95% CI 4.49-8.46), CKD stage 3-4 (3.30, 95% CI 0.85-5.75, P = 0.048 vs. non-CKD), and CKD stage 5 (1.93, 95% CI 0.27-3.59, P = 0.001 vs. non-CKD). Isofurans were higher in patients with CKD stage 5 (median 59.21 pg/mL, IQR 41.76-95.36) compared to patients with non-CKD (median 49.95 pg/mL, IQR 27.88-83.46, P = 0.001), whereas F2-isoprostanes did not differ among groups. Severity of CKD is associated with mitochondrial dysfunction and markers of oxidative stress. Mitochondrial abnormalities, which are common in skeletal muscle from patients with CKD stage 5, may explain the muscle dysfunction associated with frailty and sarcopenia in CKD Further studies are required to evaluate mitochondrial function in vivo in patients with different CKD stages.

  10. Acute exposure of Drosophila melanogaster to paraquat causes oxidative stress and mitochondrial dysfunction.

    PubMed

    Hosamani, Ravikumar

    2013-05-01

    Paraquat (PQ; 1, 1'-dimethyl-4-4'-bipyridinium), an herbicide and model neurotoxicant, is identified to be one of the prime risk factors in Parkinson's disease (PD). In the Drosophila system, PQ is commonly used to measure acquired resistance against oxidative stress (PQ resistance test). Despite this, under acute PQ exposure, data on the oxidative stress response and associated impact on mitochondria among flies is limited. Accordingly, in this study, we measured markers of oxidative stress and mitochondrial dysfunctions among adult male flies (8-10 days old) exposed to varying concentrations of PQ (10, 20, and 40 mM in 5% sucrose solution) employing a conventional filter disc method for 24 h. PQ exposure resulted in significant elevation in the levels of oxidative stress biomarkers (malondialdehyde: 43% increase: hydroperoxide: 32-39% increase), with concomitant enhancement in reduced glutathione and total thiol levels in cytosol. Higher activity of antioxidant enzymes were also evident along with increased free iron levels. Furthermore, PQ exposure caused a concentration-dependent increase in mitochondrial superoxide generation and activity of manganese-superoxide dismutase (Mn-SOD). The activity levels of complex I-III, complex II-III, and Mg+2 adinosine triphosphatase (ATPase) were also decreased significantly. A robust diminution in the activity of succinate dehydrogenase and moderate decline in the citrate synthase activity suggested a specific effect on citric acid cycle enzymes. Collectively, these data suggest that acute PQ exposure causes significant oxidative stress and mitochondrial dysfunction among flies in vivo. It is suggested that in various experimental settings, while conducting the "PQ resistance stress test" incorporation of selected biochemical end points is likely to enhance the quality of the data.

  11. Ethanol-induced oxidative stress precedes mitochondrially mediated apoptotic death of cultured fetal cortical neurons.

    PubMed

    Ramachandran, Vinitha; Watts, Lora Talley; Maffi, Shivani Kaushal; Chen, Juanjuan; Schenker, Steven; Henderson, George

    2003-11-15

    In utero ethanol exposure elicits apoptotic cell death in the fetal brain, and this may be mediated by oxidative stress. Our studies utilize cultured fetal rat cortical neurons and illustrate that ethanol elicits a rapid onset of oxidative stress, which culminates in mitochondrially mediated apoptotic cell death. Cells exposed to ethanol (2.5 mg/ml) remained attached to their polylysine matrix during a 24-hr exposure, but they exhibited distinct signs of oxidative stress, decreased viability, and apoptosis. Confocal microscopy of live cortical neurons pretreated with dichlorodihydrofluorescein diacetate demonstrated an increase in reactive oxygen species (ROS) within 5 min of ethanol exposure. The levels of ROS further increased by 58% within 1 hr (P <.05) and by 82% within 2 hr (P <.05), accompanied by increases of mitochondrial 4-hydroxynonenal (HNE). These early events were followed by decreased trypan blue exclusion of 10% to 32% (P <.05) at the 6- to 24-hr time points, respectively. This culminates in apoptotic death, with increases of Annexin V binding of 43%, 89%, 123%, and 238%, at 2, 6, 12, and 24 hr of ethanol treatment, respectively, as well as DNA fragmentation increases of 50% and 65% by 12 and 24 hr, respectively. Release of cytochrome c by mitochondria increased by 53% at 6 hr of exposure (P <.05), concomitant with activation of caspase 3 (52% at 12 hr, P <.05). Pretreatment with N-acetylcysteine increased cellular glutathione and prevented apoptosis. These studies provide a time line illustrating that oxidative stress and formation of a proapoptotic lipid peroxidation product, HNE, precede a cascade of mitochondrially mediated events in cultured fetal cortical neurons, culminating in apoptotic death. The prevention of apoptosis by augmentation of glutathione stores also strongly supports a role for oxidative stress in ethanol-mediated apoptotic death of fetal cortical neurons.

  12. Impairment of mitochondrial β-oxidation in rats under cold-hypoxic environment

    NASA Astrophysics Data System (ADS)

    Dutta, Arkadeb; Vats, Praveen; Singh, Vijay K.; Sharma, Yogendra K.; Singh, Som N.; Singh, Shashi B.

    2009-09-01

    Mitochondrial ß-oxidation of fatty acid provides a major source of energy in mammals. High altitude (HA), characterized by hypobaric hypoxia and low ambient temperatures, causes alteration in metabolic homeostasis. Several studies have depicted that hypoxic exposure in small mammals causes hypothermia due to hypometabolic state. Moreover, cold exposure along with hypoxia reduces hypoxia tolerance in animals. The present study investigated the rate of β-oxidation and key enzymes, carnitine palmitoyl transferase-I (CPT-I) and hydroxyacyl CoA dehydrogenase (HAD), in rats exposed to cold-hypobaric hypoxic environment. Male Sprague Dawley rats (190-220 g) were randomly divided into eight groups ( n = 6 rats in each group): 1 day hypoxia (H1); 7 days hypoxia (H7); 1 day cold (C1); 7 days cold (C7); 1 day cold-hypoxia (CH1); 7 days cold-hypoxia (CH7) exposed; and unexposed control for 1 and 7 days (UC1 and UC7). After exposure, animals were anaesthetized with ketamine (50 mg/kg body weight) and xylazine (10 mg/kg body weight) intraperitonialy and sacrificed. Mitochondrial CPT-I, HAD, 14C-palmitate oxidation in gastrocnemius muscle and liver, and plasma leptin were measured. Mitochondrial CPT-I was significantly reduced in muscle and liver in CH1 and CH7 as compared to respective controls. HAD activity was significantly reduced in H1 and CH7, and in H1, H7, CH1, and CH7 as compared to unexposed controls in muscle and liver, respectively. A concomitant decrease in 14C-palmitate oxidation was found. Significant reduction in plasma leptin in hypoxia and cold-hypoxia suggested hypometabolic state. It can be concluded that ß-oxidation of fatty acids is reduced in rats exposed to cold-hypoxic environment due to the persisting hypometabolic state in cold-hypoxia exposure.

  13. Biochemical properties of rat liver mitochondrial aldehyde dehydrogenase with respect to oxidation of formaldehyde.

    PubMed

    Cinti, D L; Keyes, S R; Lemelin, M A; Denk, H; Schenkman, J B

    1976-03-25

    The oxidation of formaldehyde by rat liver mitochondria in the presence of 50 mM phosphate was enhanced 2-fold by exogenous NAD+. Absolute requirement of NAD+ for formaldehyde oxidation was demonstrated by depleting the mitochondria of their NAD+ content (4.6 nmol/mg of protein), followed by reincorporation of the NAD+ into the depleted mitochondria. Aldehyde (formaldehyde) dehydrogenase activity was completely abolished in the depleted mitochondria, but the enzyme activity was restored to control levels following reincorporation of the pyridine nucleotide. Phosphate stimulation of formaldehyde oxidation could not be explained fully by the phosphate-induced swelling which enhances membrane permeability to NAD+, since stimulation of the enzyme activity by increased phosphate concentrations was still observed in the absence of exogenous NAD+. The Km for formaldehyde oxidation by the mitochondria was found to be 0.38 nM, a value similar to that obtained with varying concentrations of NAD+; both Vmax values were very similar, giving a value of 70 to 80 nmol/min/mg of protein. The pH optimum for the mitochondrial enzyme was 8.0. Inhibition of the enzyme activity by anaerobiosis was apparently due to the inability of the respiratory chain to oxidize the generated NADH. The inhibition of mitochondrial formaldehyde oxidation by succinate was found to be due to a lowering of the NAD+ level in the mitochondria. Succinate also inhibited acetaldehyde oxidation by the mitochondria. Malonate, a competitive inhibitor of succinic dehydrogenase, blocked the inhibitory effect of succinate. The respiratory chain inhibitors, rotenone, and antimycin A plus succinate, strongly inhibited formaldehyde oxidation by apparently the same mechanism, although the crude enzyme preparation (freed from the membrane) was slightly sensitive to rotenone. The mitochondria were subfractionated, and 85% of the enzyme activity was found in the inner membrane fraction (mitoplast). Furthermore, separation

  14. Prolonged exposure to insulin induces mitochondrion-derived oxidative stress through increasing mitochondrial cholesterol content in hepatocytes.

    PubMed

    Mei, Shuang; Gu, Haihua; Yang, Xuefeng; Guo, Huailan; Liu, Zhenqi; Cao, Wenhong

    2012-05-01

    We addressed the link between excessive exposure to insulin and mitochondrion-derived oxidative stress in this study and found that prolonged exposure to insulin increased mitochondrial cholesterol in cultured hepatocytes and in mice and stimulated production of reactive oxygen species (ROS) and decreased the reduced glutathione to glutathione disulfide ratio in cultured hepatocytes. Exposure of isolated hepatic mitochondria to cholesterol alone promoted ROS emission. The oxidative stress induced by the prolonged exposure to insulin was prevented by inhibition of cholesterol synthesis with simvastatin. We further found that prolonged exposure to insulin decreased mitochondrial membrane potential and the increased ROS production came from mitochondrial respiration complex I. Finally, we observed that prolonged exposure to insulin decreased mitochondrial membrane fluidity in a cholesterol synthesis-dependent manner. Together our results demonstrate that excess exposure to insulin causes mitochondrion-derived oxidative stress through cholesterol synthesis in hepatocytes.

  15. Integrative Approaches for Studying Mitochondrial and Nuclear Genome Co-evolution in Oxidative Phosphorylation

    PubMed Central

    Sunnucks, Paul; Morales, Hernán E.; Lamb, Annika M.; Pavlova, Alexandra; Greening, Chris

    2017-01-01

    In animals, interactions among gene products of mitochondrial and nuclear genomes (mitonuclear interactions) are of profound fitness, evolutionary, and ecological significance. Most fundamentally, the oxidative phosphorylation (OXPHOS) complexes responsible for cellular bioenergetics are formed by the direct interactions of 13 mitochondrial-encoded and ∼80 nuclear-encoded protein subunits in most animals. It is expected that organisms will develop genomic architecture that facilitates co-adaptation of these mitonuclear interactions and enhances biochemical efficiency of OXPHOS complexes. In this perspective, we present principles and approaches to understanding the co-evolution of these interactions, with a novel focus on how genomic architecture might facilitate it. We advocate that recent interdisciplinary advances assist in the consolidation of links between genotype and phenotype. For example, advances in genomics allow us to unravel signatures of selection in mitochondrial and nuclear OXPHOS genes at population-relevant scales, while newly published complete atomic-resolution structures of the OXPHOS machinery enable more robust predictions of how these genes interact epistatically and co-evolutionarily. We use three case studies to show how integrative approaches have improved the understanding of mitonuclear interactions in OXPHOS, namely those driving high-altitude adaptation in bar-headed geese, allopatric population divergence in Tigriopus californicus copepods, and the genome architecture of nuclear genes coding for mitochondrial functions in the eastern yellow robin. PMID:28316610

  16. Stat3 promotes mitochondrial transcription and oxidative respiration during maintenance and induction of naive pluripotency.

    PubMed

    Carbognin, Elena; Betto, Riccardo M; Soriano, Maria E; Smith, Austin G; Martello, Graziano

    2016-03-15

    Transcription factor Stat3 directs self-renewal of pluripotent mouse embryonic stem (ES) cells downstream of the cytokine leukemia inhibitory factor (LIF). Stat3 upregulates pivotal transcription factors in the ES cell gene regulatory network to sustain naïve identity. Stat3 also contributes to the rapid proliferation of ES cells. Here, we show that Stat3 increases the expression of mitochondrial-encoded transcripts and enhances oxidative metabolism. Chromatin immunoprecipitation reveals that Stat3 binds to the mitochondrial genome, consistent with direct transcriptional regulation. An engineered form of Stat3 that localizes predominantly to mitochondria is sufficient to support enhanced proliferation of ES cells, but not to maintain their undifferentiated phenotype. Furthermore, during reprogramming from primed to naïve states of pluripotency, Stat3 similarly upregulates mitochondrial transcripts and facilitates metabolic resetting. These findings suggest that the potent stimulation of naïve pluripotency by LIF/Stat3 is attributable to parallel and synergistic induction of both mitochondrial respiration and nuclear transcription factors.

  17. Oxidative stress, mitochondrial and proteostasis malfunction in adrenoleukodystrophy: A paradigm for axonal degeneration.

    PubMed

    Fourcade, Stéphane; Ferrer, Isidre; Pujol, Aurora

    2015-11-01

    Peroxisomal and mitochondrial malfunction, which are highly intertwined through redox regulation, in combination with defective proteostasis, are hallmarks of the most prevalent multifactorial neurodegenerative diseases-including Alzheimer's (AD) and Parkinson's disease (PD)-and of the aging process, and are also found in inherited conditions. Here we review the interplay between oxidative stress and axonal degeneration, taking as groundwork recent findings on pathomechanisms of the peroxisomal neurometabolic disease adrenoleukodystrophy (X-ALD). We explore the impact of chronic redox imbalance caused by the excess of very long-chain fatty acids (VLCFA) on mitochondrial respiration and biogenesis, and discuss how this impairs protein quality control mechanisms essential for neural cell survival, such as the proteasome and autophagy systems. As consequence, prime molecular targets in the pathogenetic cascade emerge, such as the SIRT1/PGC-1α axis of mitochondrial biogenesis, and the inhibitor of autophagy mTOR. Thus, we propose that mitochondria-targeted antioxidants; mitochondrial biogenesis boosters such as the antidiabetic pioglitazone and the SIRT1 ligand resveratrol; and the autophagy activator temsirolimus, a derivative of the mTOR inhibitor rapamycin, hold promise as disease-modifying therapies for X-ALD. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  18. Nitric oxide-mediated mitochondrial damage in the brain: mechanisms and implications for neurodegenerative diseases.

    PubMed

    Bolaños, J P; Almeida, A; Stewart, V; Peuchen, S; Land, J M; Clark, J B; Heales, S J

    1997-06-01

    Within the CNS and under normal conditions, nitric oxide (.NO) appears to be an important physiological signalling molecule. Its ability to increase cyclic GMP concentration suggests that .NO is implicated in the regulation of important metabolic pathways in the brain. Under certain circumstances .NO synthesis may be excessive and .NO may become neurotoxic. Excessive glutamate-receptor stimulation may lead to neuronal death through a mechanism implicating synthesis of both .NO and superoxide (O2.-) and hence peroxynitrite (ONOO-) formation. In response to lipopolysaccharide and cytokines, glial cells may also be induced to synthesize large amounts of .NO, which may be deleterious to the neighbouring neurones and oligodendrocytes. The precise mechanism of .NO neurotoxicity is not fully understood. One possibility is that it may involve neuronal energy deficiency. This may occur by ONOO- interfering with key enzymes of the tricarboxylic acid cycle, the mitochondrial respiratory chain, mitochondrial calcium metabolism, or DNA damage with subsequent activation of the energy-consuming pathway involving poly(ADP-ribose) synthetase. Possible mechanisms whereby ONOO- impairs the mitochondrial respiratory chain and the relevance for neurotoxicity are discussed. The intracellular content of reduced glutathione also appears important in determining the sensitivity of cells to ONOO- production. It is concluded that neurotoxicity elicited by excessive .NO production may be mediated by mitochondrial dysfunction leading to an energy deficiency state.

  19. The development of structure-activity relationships for mitochondrial dysfunction: uncoupling of oxidative phosphorylation.

    PubMed

    Naven, Russell T; Swiss, Rachel; Klug-McLeod, Jacquelyn; Will, Yvonne; Greene, Nigel

    2013-01-01

    Mitochondrial dysfunction has been implicated as an important factor in the development of idiosyncratic organ toxicity. An ability to predict mitochondrial dysfunction early in the drug development process enables the deselection of those drug candidates with potential safety liabilities, allowing resources to be focused on those compounds with the highest chance of success to the market. A database of greater than 2000 compounds was analyzed to identify structural and physicochemical features associated with the uncoupling of oxidative phosphorylation (herein defined as an increase in basal respiration). Many toxicophores associated with potent uncoupling activity were identified, and these could be divided into two main mechanistic classes, protonophores and redox cyclers. For the protonophores, potent uncoupling activity was often promoted by high lipophilicity and apparent stabilization of the anionic charge resulting from deprotonation of the protonophore. The potency of redox cyclers did not appear to be prone to variations in lipophilicity. Only 11 toxicophores were of sufficient predictive performance that they could be incorporated into a structural-alert model. Each alert was associated with one of three confidence levels (high, medium, and low) depending upon the lipophilicity-activity profile of the structural class. The final model identified over 68% of those compounds with potent uncoupling activity and with a value for specificity above 99%. We discuss the advantages and limitations of this approach and conclude that although structural alert methodology is useful for identifying toxicophores associated with mitochondrial dysfunction, they are not a replacement for the mitochondrial dysfunction assays in early screening paradigms.

  20. Mitochondrial dependent oxidative stress in cell culture induced by laser radiation at 1265 nm.

    PubMed

    Saenko, Yury V; Glushchenko, Eugenia S; Zolotovskii, Igor O; Sholokhov, Evgeny; Kurkov, Andrey

    2016-04-01

    Photodynamic therapy is the main technique applied for surface carcinoma treatment. This technique employs singlet oxygen generated via a laser excited photosensitizer as a main damaging agent. However, prolonged sensitivity to intensive light, relatively low tissue penetration by activating light the cost of photosensitizer (PS) administration can limit photodynamic therapy applications. Early was reported singlet oxygen generation without photosensitizer induced by a laser irradiation at the wavelength of 1250-1270 nm. Here, we study the dynamics of oxidative stress, DNA damage, changes of mitochondrial potential, and mitochondrial mass induced by a laser at 1265 nm have been studied in HCT-116 and CHO-K cells. Laser irradiation of HCT-116 and CHO-K cells has induced a dose-dependent cell death via increasing intracellular reactive oxygen species (ROS) concentration, increase of DNA damage, decrease of mitochondrial potential, and reduced glutathione. It has been shown that, along with singlet oxygen generation, the increase of the intracellular ROS concentration induced by mitochondrial damage contributes to the damaging effect of the laser irradiation at 1265 nm.

  1. [Resveratrol attenuates oxidant-induced mitochondrial damage in embryonic rat cardiomyocytes via inactivating GSK-3β].

    PubMed

    He, Yong-gui; Sun, Yu-jie; Xie, Yu-xi; Zheng, Huan; Zhang, Yi-dong; Guo, Jing; Xi, Jin-kun

    2012-10-01

    To investigate the underlying mechanism of the protective effects of resveratrol on oxidant-induced mitochondrial damage in embryonic rat cardiomyocytes. H9c2 cells, a permanent cell line derived from embryonic rat cardiac tissue, and then randomly divided into control group [PBS, cells exposed to H2O2 (600 µmol/L) for 20 min to induce mitochondrial oxidant damage], resveratrol group (0.01, 0.1, 1, 5, 10 and 20 µmol/L for 20 min at 20 min before exposing to H2O2), resveratrol plus inhibitor group (1 µmol/L KT5823 for 10 min at 10 min before 5 µmol/L resveratrol treatment) and inhibitor group (1 µmol/L KT5823 for 10 min). Mitochondrial membrane potential (ΔΨm) was measured by staining cells with tetramethylrhodamine ethyl ester (TMRE) and the mitochondrial permeability transition pore (mPTP) opening was evaluated by measuring the decrease of TMRE fluorescence intensity. Immunofluorescence assay was used to observe GSK-3β phosphorylation. The phosphorylation of GSK-3β and VASP were determined by Western blot. To detect intracellular NO, cells were loaded with DAF-FM DA (specific fluorescent dye of NO) and imaged with confocal microscopy. Compared to the control group, resveratrol (0.01-5 µmol/L) attenuated H2O2-induced mitochondrial damage reflected by attenuating the H2O2-induced TMRE fluorescence intensity decrease in a dose-dependent manner and the efficacy of 10 and 20 µmol/L resveratrol was significantly lower than that of 5 µmol/L resveratrol. Resveratrol also significantly upregulated the protein expression of VASP and increased GSK-3β Ser(9) phosphorylation, which could lead the inactivation of GSK-3β. These effects of resveratrol could be significantly abolished by protein kinase G inhibitor KT5823, while KT5823 alone did not affect GSK-3β and VASP phosphorylation. Confocal microscopy showed that DAF-FM (specific NO indicator) was similar between resveratrol and control group, suggesting that resveratrol did not produce NO. Resveratrol could

  2. Hyperammonaemia-induced skeletal muscle mitochondrial dysfunction results in cataplerosis and oxidative stress.

    PubMed

    Davuluri, Gangarao; Allawy, Allawy; Thapaliya, Samjhana; Rennison, Julie H; Singh, Dharmvir; Kumar, Avinash; Sandlers, Yana; Van Wagoner, David R; Flask, Chris A; Hoppel, Charles; Kasumov, Takhar; Dasarathy, Srinivasan

    2016-12-15

    Hyperammonaemia occurs in hepatic, cardiac and pulmonary diseases with increased muscle concentration of ammonia. We found that ammonia results in reduced skeletal muscle mitochondrial respiration, electron transport chain complex I dysfunction, as well as lower NAD(+) /NADH ratio and ATP content. During hyperammonaemia, leak of electrons from complex III results in oxidative modification of proteins and lipids. Tricarboxylic acid cycle intermediates are decreased during hyperammonaemia, and providing a cell-permeable ester of αKG reversed the lower TCA cycle intermediate concentrations and increased ATP content. Our observations have high clinical relevance given the potential for novel approaches to reverse skeletal muscle ammonia toxicity by targeting the TCA cycle intermediates and mitochondrial ROS. Ammonia is a cytotoxic metabolite that is removed primarily by hepatic ureagenesis in humans. Hyperammonaemia occurs in advanced hepatic, cardiac and pulmonary disease, and in urea cycle enzyme deficiencies. Increased skeletal muscle ammonia uptake and metabolism are the major mechanism of non-hepatic ammonia disposal. Non-hepatic ammonia disposal occurs in the mitochondria via glutamate synthesis from α-ketoglutarate resulting in cataplerosis. We show skeletal muscle mitochondrial dysfunction during hyperammonaemia in a comprehensive array of human, rodent and cellular models. ATP synthesis, oxygen consumption, generation of reactive oxygen species with oxidative stress, and tricarboxylic acid (TCA) cycle intermediates were quantified. ATP content was lower in the skeletal muscle from cirrhotic patients, hyperammonaemic portacaval anastomosis rat, and C2C12 myotubes compared to appropriate controls. Hyperammonaemia in C2C12 myotubes resulted in impaired intact cell respiration, reduced complex I/NADH oxidase activity and electron leak occurring at complex III of the electron transport chain. Consistently, lower NAD(+) /NADH ratio was observed during

  3. High concentrations of stavudine impair fatty acid oxidation without depleting mitochondrial DNA in cultured rat hepatocytes.

    PubMed

    Igoudjil, Anissa; Massart, Julie; Begriche, Karima; Descatoire, Véronique; Robin, Marie-Anne; Fromenty, Bernard

    2008-06-01

    The antiretroviral nucleoside reverse-transcriptase inhibitor (NRTI) stavudine (d4T) can induce mild to severe liver injuries such as steatosis (i.e. triglyceride accumulation), steatohepatitis and liver failure. NRTI-induced toxicity has been ascribed to the inhibition of mitochondrial DNA (mtDNA) replication causing mtDNA depletion and respiratory chain dysfunction. This can secondarily impair the tricarboxylic acid cycle and fatty acid oxidation (FAO), thus leading to lactic acidosis and hepatic steatosis. However, NRTIs could also impair mitochondrial function and induce hepatic steatosis through other mechanisms. In this study, we sought to determine whether d4T could inhibit mitochondrial FAO and induce triglyceride accumulation through a mtDNA-independent mechanism. Since human tumoral and non-tumoral hepatic cell lines were unable to efficiently oxidize palmitic acid, the effects of d4T on mitochondrial FAO were assessed on cultured rat hepatocytes. Our results showed that 750 microM of d4T significantly inhibited palmitic acid oxidation after 48 or 72 h of culture, without inducing cell death. Importantly, high concentrations of zidovudine and zalcitabine (two other NRTIs that can induce hepatic steatosis), or beta-aminoisobutyric acid (a d4T metabolite), did not impair FAO in rat hepatocytes. D4T-induced FAO inhibition was observed without mtDNA depletion and lactate production, and was fully prevented with l-carnitine or clofibrate coincubation. l-carnitine also prevented the accretion of neutral lipids within rat hepatocytes. High concentrations of d4T were unable to inhibit FAO on freshly isolated liver mitochondria. Moreover, a microarray analysis was performed to clarify the mechanism whereby d4T can inhibit mitochondrial FAO and induce triglyceride accumulation in rat hepatocytes. The microarray data, confirmed by quantitative real-time PCR analysis, showed that d4T increased the expression of sterol regulatory element-binding protein-1c (SREBP1c

  4. Long-Term Exposure to AZT, but not d4T, Increases Endothelial Cell Oxidative Stress and Mitochondrial Dysfunction

    PubMed Central

    Kline, Erik R.; Bassit, Leda; Hernandez-Santiago, Brenda I.; Detorio, Mervi A.; Liang, Bill; Kleinhenz, Dean J.; Walp, Erik R.; Dikalov, Sergey; Jones, Dean P.; Schinazi, Raymond F.

    2009-01-01

    Nucleoside reverse transcriptase inhibitors (NRTIs), such as zidovudine (AZT) and stavudine (d4T), cause toxicities to numerous tissues, including the liver and vasculature. While much is known about hepatic NRTI toxicity, the mechanism of toxicity in endothelial cells is incompletely understood. Human aortic endothelial and HepG2 liver cells were exposed to 1 μM AZT or d4T for up to 5 weeks. Markers of oxidative stress, mitochondrial function, NRTI phosphorylation, mitochondrial DNA (mtDNA) levels, and cytotoxicity were monitored over time. In endothelial cells, AZT significantly oxidized glutathione redox potential, increased total cellular and mitochondrial-specific superoxide, decreased mitochondrial membrane potential, increased lactate release, and caused cell death from weeks 3 through 5. Toxicity occurred in the absence of di- and tri-phosphorylated AZT and mtDNA depletion. These data show that oxidative stress and mitochondrial dysfunction in endothelial cells occur with a physiologically relevant concentration of AZT, and require long-term exposure to develop. In contrast, d4T did not induce endothelial oxidative stress, mitochondrial dysfunction, or cytotoxicity despite the presence of d4T-triphosphate. Both drugs depleted mtDNA in HepG2 cells without causing cell death. Endothelial cells are more susceptible to AZT-induced toxicity than HepG2 cells, and AZT caused greater endothelial dysfunction than d4T because of its pro-oxidative effects. PMID:19067249

  5. Oxidants, antioxidants and mitochondrial function in non-proliferative diabetic retinopathy

    PubMed Central

    Rodríguez-Carrizalez, Adolfo Daniel; Castellanos-González, José Alberto; Martínez-Romero, Esaú César; Miller-Arrevillaga, Guillermo; Villa-Hernández, David; Hernández-Godínez, Pedro Pablo; Ortiz, Genaro Gabriel; Pacheco-Moisés, Fermín Paul; Cardona-Muñoz, Ernesto Germán; Miranda-Díaz, Alejandra Guillermina

    2014-01-01

    Background Diabetic retinopathy (DR) is a preventable cause of visual disability. The aims of the present study were to investigate levels and behavior oxidative stress markers and mitochondrial function in non-proliferative DR (NPDR) and to establish the correlation between the severity of NPDR and markers of oxidative stress and mitochondrial function. Methods In a transverse analysis, type 2 diabetes mellitus (T2DM) patients with mild, moderate and severe non-proliferative DR (NPDR) were evaluated for markers of oxidative stress (i.e. products of lipid peroxidation (LPO) and nitric oxide (NO) catabolites) and antioxidant activity (i.e. total antioxidant capacity (TAC), catalase, and glutathione peroxidase (GPx) activity of erythrocytes). Mitochondrial function was also determined as the fluidity of the submitochondrial particles of platelets and the hydrolytic activity of F0/F1-ATPase. Results Levels of LPO and NO were significantly increased in T2DM patients with severe NPDR (3.19 ± 0.05 μmol/mL and 45.62 ± 1.27 pmol/mL, respectively; P < 0.007 and P < 0.0001 vs levels in health volunteers, respectively), suggesting the presence of oxidative stress. TAC had significant decrease levels with minimum peak in severe retinopathy with 7.98 ± 0.48 mEq/mL (P < 0.0001). In contrast with TAC, erythrocyte catalase and GPx activity was increased in patients with severe NPDR (139.4 ± 4.4 and 117.13 ± 14.84 U/mg, respectively; P < 0.0001 vs healthy volunteers for both), suggesting an imbalance between oxidants and antioxidants. The fluidity of membrane submitochondrial particles decreased significantly in T2DM patients with mild, moderate, or severe NPDR compared with that in healthy volunteers (P < 0.0001 for all). Furthermore, there was a significant increase in the hydrolytic activity of the F0/F1-ATPase in T2DM patients with mild NPDR (265.07 ± 29.55 nmol/PO4; P < 0.0001 vs healthy volunteers), suggesting

  6. Phylogenomic Evidence for a Myxococcal Contribution to the Mitochondrial Fatty Acid Beta-Oxidation

    PubMed Central

    Schlüter, Agatha; Ruiz-Trillo, Iñaki; Pujol, Aurora

    2011-01-01

    Background The origin of eukaryotes remains a fundamental question in evolutionary biology. Although it is clear that eukaryotic genomes are a chimeric combination of genes of eubacterial and archaebacterial ancestry, the specific ancestry of most eubacterial genes is still unknown. The growing availability of microbial genomes offers the possibility of analyzing the ancestry of eukaryotic genomes and testing previous hypotheses on their origins. Methodology/Principal Findings Here, we have applied a phylogenomic analysis to investigate a possible contribution of the Myxococcales to the first eukaryotes. We conducted a conservative pipeline with homologous sequence searches against a genomic sampling of 40 eukaryotic and 357 prokaryotic genomes. The phylogenetic reconstruction showed that several eukaryotic proteins traced to Myxococcales. Most of these proteins were associated with mitochondrial lipid intermediate pathways, particularly enzymes generating reducing equivalents with pivotal roles in fatty acid β-oxidation metabolism. Our data suggest that myxococcal species with the ability to oxidize fatty acids transferred several genes to eubacteria that eventually gave rise to the mitochondrial ancestor. Later, the eukaryotic nucleocytoplasmic lineage acquired those metabolic genes through endosymbiotic gene transfer. Conclusions/Significance Our results support a prokaryotic origin, different from α-proteobacteria, for several mitochondrial genes. Our data reinforce a fluid prokaryotic chromosome model in which the mitochondrion appears to be an important entry point for myxococcal genes to enter eukaryotes. PMID:21760940

  7. KETONES INHIBIT MITOCHONDRIAL PRODUCTION OF REACTIVE OXYGEN SPECIES PRODUCTION FOLLOWING GLUTAMATE EXCITOTOXICITY BY INCREASING NADH OXIDATION

    PubMed Central

    Maalouf, Marwan; Sullivan, Patrick G.; Davis, Laurie; Kim, Do Young; Rho, Jong M.

    2007-01-01

    Dietary protocols that increase serum levels of ketones, such as calorie restriction and the ketogenic diet, offer robust protection against a multitude of acute and chronic neurological diseases. The underlying mechanisms, however, remain unclear. Previous studies have suggested that the ketogenic diet may reduce free radical levels in the brain. Thus, one possibility is that ketones may mediate neuroprotection through antioxidant activity. In the present study, we examined the effects of the ketones β-hydroxybutyrate and acetoacetate on acutely dissociated rat neocortical neurons subjected to glutamate excitotoxicity using cellular electrophysiological and single-cell fluorescence imaging techniques. Further, we explored the effects of ketones on acutely isolated mitochondria exposed to high levels of calcium. A combination of β-hydroxybutyrate and acetoacetate (1 mM each) decreased neuronal death and prevented changes in neuronal membrane properties induced by 10 μM glutamate. Ketones also significantly decreased mitochondrial production of reactive oxygen species and the associated excitotoxic changes by increasing NADH oxidation in the mitochondrial respiratory chain, but did not affect levels of the endogenous antioxidant glutathione. In conclusion, we demonstrate that ketones reduce glutamate-induced free radical formation by increasing the NAD+/NADH ratio and enhancing mitochondrial respiration in neocortical neurons. This mechanism may, in part, contribute to the neuroprotective activity of ketones by restoring normal bioenergetic function in the face of oxidative stress. PMID:17240074

  8. Elimination of damaged mitochondria through mitophagy reduces mitochondrial oxidative stress and increases tolerance to trichothecenes.

    PubMed

    Bin-Umer, Mohamed Anwar; McLaughlin, John E; Butterly, Matthew S; McCormick, Susan; Tumer, Nilgun E

    2014-08-12

    Trichothecene mycotoxins are natural contaminants of small grain cereals and are encountered in the environment, posing a worldwide threat to human and animal health. Their mechanism of toxicity is poorly understood, and little is known about cellular protection mechanisms against trichothecenes. We previously identified inhibition of mitochondrial protein synthesis as a novel mechanism for trichothecene-induced cell death. To identify cellular functions involved in trichothecene resistance, we screened the Saccharomyces cerevisiae deletion library for increased sensitivity to nonlethal concentrations of trichothecin (Tcin) and identified 121 strains exhibiting higher sensitivity than the parental strain. The largest group of sensitive strains had significantly higher reactive oxygen species (ROS) levels relative to the parental strain. A dose-dependent increase in ROS levels was observed in the parental strain treated with different trichothecenes, but not in a petite version of the parental strain or in the presence of a mitochondrial membrane uncoupler, indicating that mitochondria are the main site of ROS production due to toxin exposure. Cytotoxicity of trichothecenes was alleviated after treatment of the parental strain and highly sensitive mutants with antioxidants, suggesting that oxidative stress contributes to trichothecene sensitivity. Cotreatment with rapamycin and trichothecenes reduced ROS levels and cytotoxicity in the parental strain relative to the trichothecene treatment alone, but not in mitophagy deficient mutants, suggesting that elimination of trichothecene-damaged mitochondria by mitophagy improves cell survival. These results reveal that increased mitophagy is a cellular protection mechanism against trichothecene-induced mitochondrial oxidative stress and a potential target for trichothecene resistance.

  9. Oxidative stress generated during monensin treatment contributes to altered Toxoplasma gondii mitochondrial function.

    PubMed

    Charvat, Robert A; Arrizabalaga, Gustavo

    2016-03-15

    The ionophore monensin displays potent activities against several coccidian parasites of veterinary and medical importance including the opportunistic pathogen of humans, Toxoplasma gondii. While monensin is used widely in animals, toxicity impedes its use in humans. Nonetheless, given its potency, understanding its mode of action would reveal vulnerable aspects of the parasite that can be exploited for drug development. We previously established that monensin induces Toxoplasma to undergo cell cycle arrest and an autophagy-like cell death. Interestingly, these effects are dependent on the mitochondrion-localized TgMSH-1 protein, suggesting that monensin disrupts mitochondrial function. We demonstrate that monensin treatment results in decreased mitochondrial membrane potential and altered morphology. These effects are mitigated by the antioxidant compound N-acetyl-cysteine suggesting that monensin causes an oxidative stress, which was indeed the case based on direct detection of reactive oxygen species. Moreover, over-expression of the antioxidant proteins glutaredoxin and peroxiredoxin 2 protect Toxoplasma from the deleterious effects of monensin. Thus, our studies show that the effects of monensin on Toxoplasma are due to a disruption of mitochondrial function caused by the induction of an oxidative stress and implicate parasite redox biology as a viable target for the development of drugs against Toxoplasma and related pathogenic parasites.

  10. Mitochondrial Dysfunction and Oxidative Stress in Asthma: Implications for Mitochondria-Targeted Antioxidant Therapeutics

    PubMed Central

    Reddy, P. Hemachandra

    2011-01-01

    Asthma is a complex, inflammatory disorder characterized by airflow obstruction of variable degrees, bronchial hyper-responsiveness, and airway inflammation. Asthma is caused by environmental factors and a combination of genetic and environmental stimuli. Genetic studies have revealed that multiple loci are involved in the etiology of asthma. Recent cellular, molecular, and animal-model studies have revealed several cellular events that are involved in the progression of asthma, including: increased Th2 cytokines leading to the recruitment of inflammatory cells to the airway, and an increase in the production of reactive oxygen species and mitochondrial dysfunction in the activated inflammatory cells, leading to tissue injury in the bronchial epithelium. Further, aging and animal model studies have revealed that mitochondrial dysfunction and oxidative stress are involved and play a large role in asthma. Recent studies using experimental allergic asthmatic mouse models and peripheral cells and tissues from asthmatic humans have revealed antioxidants as promising treatments for people with asthma. This article summarizes the latest research findings on the involvement of inflammatory changes, and mitochondrial dysfunction/oxidative stress in the development and progression of asthma. This article also addresses the relationship between aging and age-related immunity in triggering asthma, the antioxidant therapeutic strategies in treating people with asthma. PMID:21461182

  11. Oxidative stress generated during monensin treatment contributes to altered Toxoplasma gondii mitochondrial function

    PubMed Central

    Charvat, Robert A.; Arrizabalaga, Gustavo

    2016-01-01

    The ionophore monensin displays potent activities against several coccidian parasites of veterinary and medical importance including the opportunistic pathogen of humans, Toxoplasma gondii. While monensin is used widely in animals, toxicity impedes its use in humans. Nonetheless, given its potency, understanding its mode of action would reveal vulnerable aspects of the parasite that can be exploited for drug development. We previously established that monensin induces Toxoplasma to undergo cell cycle arrest and an autophagy-like cell death. Interestingly, these effects are dependent on the mitochondrion-localized TgMSH-1 protein, suggesting that monensin disrupts mitochondrial function. We demonstrate that monensin treatment results in decreased mitochondrial membrane potential and altered morphology. These effects are mitigated by the antioxidant compound N-acetyl-cysteine suggesting that monensin causes an oxidative stress, which was indeed the case based on direct detection of reactive oxygen species. Moreover, over-expression of the antioxidant proteins glutaredoxin and peroxiredoxin 2 protect Toxoplasma from the deleterious effects of monensin. Thus, our studies show that the effects of monensin on Toxoplasma are due to a disruption of mitochondrial function caused by the induction of an oxidative stress and implicate parasite redox biology as a viable target for the development of drugs against Toxoplasma and related pathogenic parasites. PMID:26976749

  12. Nickel(II)-induced nasal epithelial toxicity and oxidative mitochondrial damage.

    PubMed

    Lee, Yoon-Jin; Lim, Soo-Sung; Baek, Byoung Joon; An, Je-Min; Nam, Hae-Seon; Woo, Kee-Min; Cho, Moon-Kyun; Kim, Sung-Ho; Lee, Sang-Han

    2016-03-01

    In probing the underlying mechanisms of nickel(II)-induced cytotoxicity on nasal epithelium, we investigated the effects of nickel(II) acetate on nasal epithelial RPMI-2650 cells. Nickel(II) elicited apoptosis, as signified by pyknotic and fragmented nuclei, increased caspase-3/7 activity, and an increase in annexin V binding, hypodiploid DNA, and Bax/Bcl-2 protein ratio. Nickel(II)-induced G2/M arrest was associated with up-regulation of p21(WAF1/CIP1) expression, decrease in phosphorylation at Thr(161) of Cdc2, and down-regulation of cyclin B1. Associated with these responses, ROS generation and mitochondrial depolarization increased in a nickel(II) concentration-dependent fashion. Pretreatment with N-acetylcysteine (NAC) attenuated these changes. p53 reporter gene assay and analyses of p53, Puma, Bax, and Bcl-2 protein levels indicated that NAC inhibited nickel(II)-induced activation of p53-mediated mitochondrial apoptotic pathway. Collectively, our study provides evidences that nickel(II) may induce oxidative damage on nasal epithelium in which antioxidant NAC protects cells against nickel(II)-induced apoptosis through the prevention of oxidative stress-mediated mitochondrial damage.

  13. Salvianolate Protects Hepatocytes from Oxidative Stress by Attenuating Mitochondrial Injury

    PubMed Central

    Zhao, Qiang; Peng, Yuan; Huang, Kai; Lei, Yang; Liu, Hong-Liang; Tao, Yan-Yan

    2016-01-01

    Salvianolate is widely used to treat angiocardiopathy in clinic in China, but its application in liver diseases remains unclear. Our study aims to investigate the effect of Salvianolate on rat hepatic injury by protecting hepatocyte mitochondria. To evaluate the effects of Salvianolate on injured hepatocytes, alpha mouse liver 12 (AML-12) cells were induced with hydrogen peroxide (H2O2) and treated with Salvianolate. Cell viability and MitoTracker Green for mitochondria and 5,5′,6,6′-tetrachloro-1,1′,3,3′-tetraethylbenzimidazole-carbocyanide iodine (JC-1) levels and cytochrome C (Cyto-C) expressions were detected in vitro. To identify the effect of Salvianolate on protecting against mitochondria injury, male Wistar rats were injected with carbon tetrachloride (CCl4) and treated with Salvianolate (40 mg·kg−1). Serum liver function, parameters for peroxidative damage, hematoxylin and eosin (H&E) staining, and transmission electron microscope (TEM) of hepatocyte mitochondria were assayed. Our results showed that Salvianolate effectively protected hepatocytes, increased mitochondria vitality, and decreased Cyto-C expressions in vitro. Besides, Salvianolate alleviated the liver function, attenuated the indicators of peroxidation, and relieved the mitochondria injury in vivo. In conclusion, Salvianolate is effective in protecting hepatocytes from injury in vitro and in vivo, and the mechanism might be related to its protective effect on hepatocyte mitochondria against oxidative stress. PMID:27340417

  14. Salvianolate Protects Hepatocytes from Oxidative Stress by Attenuating Mitochondrial Injury.

    PubMed

    Zhao, Qiang; Peng, Yuan; Huang, Kai; Lei, Yang; Liu, Hong-Liang; Tao, Yan-Yan; Liu, Cheng-Hai

    2016-01-01

    Salvianolate is widely used to treat angiocardiopathy in clinic in China, but its application in liver diseases remains unclear. Our study aims to investigate the effect of Salvianolate on rat hepatic injury by protecting hepatocyte mitochondria. To evaluate the effects of Salvianolate on injured hepatocytes, alpha mouse liver 12 (AML-12) cells were induced with hydrogen peroxide (H2O2) and treated with Salvianolate. Cell viability and MitoTracker Green for mitochondria and 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazole-carbocyanide iodine (JC-1) levels and cytochrome C (Cyto-C) expressions were detected in vitro. To identify the effect of Salvianolate on protecting against mitochondria injury, male Wistar rats were injected with carbon tetrachloride (CCl4) and treated with Salvianolate (40 mg·kg(-1)). Serum liver function, parameters for peroxidative damage, hematoxylin and eosin (H&E) staining, and transmission electron microscope (TEM) of hepatocyte mitochondria were assayed. Our results showed that Salvianolate effectively protected hepatocytes, increased mitochondria vitality, and decreased Cyto-C expressions in vitro. Besides, Salvianolate alleviated the liver function, attenuated the indicators of peroxidation, and relieved the mitochondria injury in vivo. In conclusion, Salvianolate is effective in protecting hepatocytes from injury in vitro and in vivo, and the mechanism might be related to its protective effect on hepatocyte mitochondria against oxidative stress.

  15. Joint toxicity of chlorpyrifos and cadmium on the oxidative stress and mitochondrial damage in neuronal cells.

    PubMed

    Xu, Ming-Yuan; Wang, Pan; Sun, Ying-Jian; Yang, Lin; Wu, Yi-Jun

    2017-05-01

    Pesticides and heavy metals can be easily biomagnified in food chains and bioaccumulated in individuals, thus pose significant threat to human health. However, their joint toxicity for long-term exposure at low dose has not been thoroughly investigated. In the present study, we investigated the oxidative damages in brain of rats exposed subchronically to organophosphorus pesticide chlorpyrifos (CPF) and heavy metal cadmium (Cd), and their mixtures at the environmentally relevant doses. Rats were given different doses of CPF and Cd by oral gavage for three months. After treatment, brain tissues were subjected for biochemical analysis. Mitochondrial damage and reactive oxidative species were also measured in neuroblastoma SH-SY5Y cells treated with CPF, Cd and their mixtures. The results showed that CPF and Cd generated protein and lipid peroxidation, disturbed the total antioxidant capability, and altered mitochondria ultrastructure in the brain. Lipids and proteins were sensitive to the oxidative damage induced by CPF and Cd. CPF and Cd decreased mitochondrial potential and induced reactive oxygen species in SH-SY5Y cells. However, the mixture did not display higher toxicity than the sum of that of the individual treatments. Thus, CPF and Cd could have a potential antagonistic interaction on the induction of oxidative stress. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Mitochondrial Dysfunction Increases Oxidative Stress and Decreases Chronological Life Span in Fission Yeast

    PubMed Central

    García-Santamarina, Sarela; Hoe, Kwang-Lae; Kim, Dong Uk; Park, Han-Oh; Hayles, Jacqueline; Ayté, José; Hidalgo, Elena

    2008-01-01

    Background Oxidative stress is a probable cause of aging and associated diseases. Reactive oxygen species (ROS) originate mainly from endogenous sources, namely the mitochondria. Methodology/Principal Findings We analyzed the effect of aerobic metabolism on oxidative damage in Schizosaccharomyces pombe by global mapping of those genes that are required for growth on both respiratory-proficient media and hydrogen-peroxide-containing fermentable media. Out of a collection of approximately 2700 haploid yeast deletion mutants, 51 were sensitive to both conditions and 19 of these were related to mitochondrial function. Twelve deletion mutants lacked components of the electron transport chain. The growth defects of these mutants can be alleviated by the addition of antioxidants, which points to intrinsic oxidative stress as the origin of the phenotypes observed. These respiration-deficient mutants display elevated steady-state levels of ROS, probably due to enhanced electron leakage from their defective transport chains, which compromises the viability of chronologically-aged cells. Conclusion/Significance Individual mitochondrial dysfunctions have often been described as the cause of diseases or aging, and our global characterization emphasizes the primacy of oxidative stress in the etiology of such processes. PMID:18665268

  17. Spongionella Secondary Metabolites Protect Mitochondrial Function in Cortical Neurons against Oxidative Stress

    PubMed Central

    Leirós, Marta; Sánchez, Jon A.; Alonso, Eva; Rateb, Mostafa E.; Houssen, Wael E.; Ebel, Rainer; Jaspars, Marcel; Alfonso, Amparo; Botana, Luis M.

    2014-01-01

    The marine habitat provides a large number of structurally-diverse bioactive compounds for drug development. Marine sponges have been studied over many years and are found to be a rich source of these bioactive chemicals. This study is focused on the evaluation of the activity of six diterpene derivatives isolated from Spongionella sp. on mitochondrial function using an oxidative in vitro stress model. The test compounds include the Gracilins (A, H, K, J and L) and tetrahydroaplysulphurin-1. Compounds were co-incubated with hydrogen peroxide for 12 hours to determine their protective capacities and their effect on markers of apoptosis and Nrf2/ARE pathways was evaluated. Results conclude that Gracilins preserve neurons against oxidative damage, and that in particular, tetrahydroaplysulphurin-1 shows a complete neuroprotective activity. Oxidative stress is linked to mitochondrial dysfunction and consequently to neurodegenerative disorders like Parkinson and Alzheimer diseases, Friedreich ataxia or Amyotrophic lateral sclerosis. This neuroprotection against oxidation conditions suggest that these metabolites could be interesting lead candidates in drug development for neurodegenerative diseases. PMID:24473170

  18. Novel role of FATP1 in mitochondrial fatty acid oxidation in skeletal muscle cells

    PubMed Central

    Sebastián, David; Guitart, Maria; García-Martínez, Celia; Mauvezin, Caroline; Orellana-Gavaldà, Josep M.; Serra, Dolors; Gómez-Foix, Anna M.; Hegardt, Fausto G.; Asins, Guillermina

    2009-01-01

    Carnitine palmitoyltransferase 1 (CPT1) catalyzes the first step in long-chain fatty acid import into mitochondria, and it is believed to be rate limiting for β-oxidation of fatty acids. However, in muscle, other proteins may collaborate with CPT1. Fatty acid translocase/CD36 (FAT/CD36) may interact with CPT1 and contribute to fatty acid import into mitochondria in muscle. Here, we demonstrate that another membrane-bound fatty acid binding protein, fatty acid transport protein 1 (FATP1), collaborates with CPT1 for fatty acid import into mitochondria. Overexpression of FATP1 using adenovirus in L6E9 myotubes increased both fatty acid oxidation and palmitate esterification into triacylglycerides. Moreover, immunocytochemistry assays in transfected L6E9 myotubes showed that FATP1 was present in mitochondria and coimmunoprecipitated with CPT1 in L6E9 myotubes and rat skeletal muscle in vivo. The cooverexpression of FATP1 and CPT1 also enhanced mitochondrial fatty acid oxidation, similar to the cooverexpression of FAT/CD36 and CPT1. However, etomoxir, an irreversible inhibitor of CPT1, blocked all these effects. These data reveal that FATP1, like FAT/CD36, is associated with mitochondria and has a role in mitochondrial oxidation of fatty acids. PMID:19429947

  19. Mitochondrial impairment and melatonin protection in parkinsonian mice do not depend of inducible or neuronal nitric oxide synthases

    PubMed Central

    López, Ana; Ortiz, Francisco; Doerrier, Carolina; Venegas, Carmen; Fernández-Ortiz, Marisol; Aranda, Paula; Díaz-Casado, María E.; Fernández-Gil, Beatriz; Barriocanal-Casado, Eliana; Escames, Germaine; López, Luis C.

    2017-01-01

    MPTP-mouse model constitutes a well-known model of neuroinflammation and mitochondrial failure occurring in Parkinson’s disease (PD). Although it has been extensively reported that nitric oxide (NO●) plays a key role in the pathogenesis of PD, the relative roles of nitric oxide synthase isoforms iNOS and nNOS in the nigrostriatal pathway remains, however, unclear. Here, the participation of iNOS/nNOS isoforms in the mitochondrial dysfunction was analyzed in iNOS and nNOS deficient mice. Our results showed that MPTP increased iNOS activity in substantia nigra and striatum, whereas it sharply reduced complex I activity and mitochondrial bioenergetics in all strains. In the presence of MPTP, mice lacking iNOS showed similar restricted mitochondrial function than wild type or mice lacking nNOS. These results suggest that iNOS-dependent elevated nitric oxide, a major pathological hallmark of neuroinflammation in PD, does not contribute to mitochondrial impairment. Therefore, neuroinflammation and mitochondrial dysregulation seem to act in parallel in the MPTP model of PD. Melatonin administration, with well-reported neuroprotective properties, counteracted these effects, preventing from the drastic changes in mitochondrial oxygen consumption, increased NOS activity and prevented reduced locomotor activity induced by MPTP. The protective effects of melatonin on mitochondria are also independent of its anti-inflammatory properties, but both effects are required for an effective anti-parkinsonian activity of the indoleamine as reported in this study. PMID:28800639

  20. Mitochondrial impairment and melatonin protection in parkinsonian mice do not depend of inducible or neuronal nitric oxide synthases.

    PubMed

    López, Ana; Ortiz, Francisco; Doerrier, Carolina; Venegas, Carmen; Fernández-Ortiz, Marisol; Aranda, Paula; Díaz-Casado, María E; Fernández-Gil, Beatriz; Barriocanal-Casado, Eliana; Escames, Germaine; López, Luis C; Acuña-Castroviejo, Darío

    2017-01-01

    MPTP-mouse model constitutes a well-known model of neuroinflammation and mitochondrial failure occurring in Parkinson's disease (PD). Although it has been extensively reported that nitric oxide (NO●) plays a key role in the pathogenesis of PD, the relative roles of nitric oxide synthase isoforms iNOS and nNOS in the nigrostriatal pathway remains, however, unclear. Here, the participation of iNOS/nNOS isoforms in the mitochondrial dysfunction was analyzed in iNOS and nNOS deficient mice. Our results showed that MPTP increased iNOS activity in substantia nigra and striatum, whereas it sharply reduced complex I activity and mitochondrial bioenergetics in all strains. In the presence of MPTP, mice lacking iNOS showed similar restricted mitochondrial function than wild type or mice lacking nNOS. These results suggest that iNOS-dependent elevated nitric oxide, a major pathological hallmark of neuroinflammation in PD, does not contribute to mitochondrial impairment. Therefore, neuroinflammation and mitochondrial dysregulation seem to act in parallel in the MPTP model of PD. Melatonin administration, with well-reported neuroprotective properties, counteracted these effects, preventing from the drastic changes in mitochondrial oxygen consumption, increased NOS activity and prevented reduced locomotor activity induced by MPTP. The protective effects of melatonin on mitochondria are also independent of its anti-inflammatory properties, but both effects are required for an effective anti-parkinsonian activity of the indoleamine as reported in this study.

  1. Quercetin protects against aluminium induced oxidative stress and promotes mitochondrial biogenesis via activation of the PGC-1α signaling pathway.

    PubMed

    Sharma, Deep Raj; Sunkaria, Aditya; Wani, Willayat Yousuf; Sharma, Reeta Kumari; Verma, Deepika; Priyanka, Kumari; Bal, Amanjit; Gill, Kiran Dip

    2015-12-01

    The present investigation was carried out to elucidate a possible molecular mechanism related to the protective effect of quercetin administration against aluminium-induced oxidative stress on various mitochondrial respiratory complex subunits with special emphasis on the role of PGC-1α and its downstream targets, i.e. NRF-1, NRF-2 and Tfam in mitochondrial biogenesis. Aluminium lactate (10mg/kg b.wt./day) was administered intragastrically to rats, which were pre-treated with quercetin 6h before aluminium (10mg/kg b.wt./day, intragastrically) for 12 weeks. We found a decrease in ROS levels, mitochondrial DNA oxidation and citrate synthase activity in the hippocampus (HC) and corpus striatum (CS) regions of rat brain treated with quercetin. Besides this an increase in the mRNA levels of the mitochondrial encoded subunits - ND1, ND2, ND3, Cyt b, COX1, COX3 and ATPase6 along with increased expression of nuclear encoded subunits COX4, COX5A and COX5B of electron transport chain (ETC). In quercetin treated group an increase in the mitochondrial DNA copy number and mitochondrial content in both the regions of rat brain was observed. The PGC-1α was up regulated in quercetin treated rats along with NRF-1, NRF-2 and Tfam, which act downstream from PGC-1α. Electron microscopy results revealed a significant decrease in the mitochondrial cross-section area, mitochondrial perimeter length and increase in mitochondrial number in case of quercetin treated rats as compared to aluminium treated ones. Therefore it seems quercetin increases mitochondrial biogenesis and makes it an almost ideal flavanoid to control or limit the damage that has been associated with the defective mitochondrial function seen in many neurodegenerative diseases. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. Behavioral deficit, oxidative stress, and mitochondrial dysfunction precede tau pathology in P301S transgenic mice

    PubMed Central

    Dumont, Magali; Stack, Cliona; Elipenahli, Ceyhan; Jainuddin, Shari; Gerges, Meri; Starkova, Natalia N.; Yang, Lichuan; Starkov, Anatoly A.; Beal, Flint

    2011-01-01

    Abnormal tau accumulation can lead to the development of neurodegenerative diseases. P301S mice overexpress the human tau mutated gene, resulting in tau hyperphosphorylation and tangle formation. Mice also develop synaptic deficits and microglial activation prior to any neurodegeneration and tangles. Oxidative stress can also affect tauopathy. We studied the role of oxidative stress in relationship to behavioral abnormalities and disease progression in P301S mice at 2, 7, and 10 mo of age. At 7 mo of age, P301S mice had behavioral abnormalities, such as hyperactivity and disinhibition. At the same age, we observed increased carbonyls in P301S mitochondria (∼215 and 55% increase, males/females), and deregulation in the activity and content of mitochondrial enzymes involved in reactive oxygen species formation and energy metabolism, such as citrate synthase (∼19 and ∼5% decrease, males/females), MnSOD (∼16% decrease, males only), cytochrome C (∼19% decrease, females only), and cytochrome C oxidase (∼20% increase, females only). These changes in mitochondria proteome appeared before tau hyperphosphorylation and tangle formation, which were observed at 10 mo and were associated with GSK3β activation. At that age, mitochondria proteome deregulation became more apparent in male P301S mitochondria. The data strongly suggest that oxidative stress and mitochondrial abnormalities appear prior to tau pathology.—Dumont, M., Stack, C., Elipenahli, C., Jainuddin, S., Gerges, M., Starkova, M. N., Yang, L., Starkov, A. A., Beal, F. Behavioral deficit, oxidative stress, and mitochondrial dysfunction precede tau pathology in P301S transgenic mice. PMID:21825035

  3. Apelin Treatment Increases Complete Fatty Acid Oxidation, Mitochondrial Oxidative Capacity, and Biogenesis in Muscle of Insulin-Resistant Mice

    PubMed Central

    Attané, Camille; Foussal, Camille; Le Gonidec, Sophie; Benani, Alexandre; Daviaud, Danièle; Wanecq, Estelle; Guzmán-Ruiz, Rocío; Dray, Cédric; Bezaire, Veronic; Rancoule, Chloé; Kuba, Keiji; Ruiz-Gayo, Mariano; Levade, Thierry; Penninger, Josef; Burcelin, Rémy; Pénicaud, Luc; Valet, Philippe; Castan-Laurell, Isabelle

    2012-01-01

    Both acute and chronic apelin treatment have been shown to improve insulin sensitivity in mice. However, the effects of apelin on fatty acid oxidation (FAO) during obesity-related insulin resistance have not yet been addressed. Thus, the aim of the current study was to determine the impact of chronic treatment on lipid use, especially in skeletal muscles. High-fat diet (HFD)-induced obese and insulin-resistant mice treated by an apelin injection (0.1 μmol/kg/day i.p.) during 4 weeks had decreased fat mass, glycemia, and plasma levels of triglycerides and were protected from hyperinsulinemia compared with HFD PBS-treated mice. Indirect calorimetry experiments showed that apelin-treated mice had a better use of lipids. The complete FAO, the oxidative capacity, and mitochondrial biogenesis were increased in soleus of apelin-treated mice. The action of apelin was AMP-activated protein kinase (AMPK) dependent since all the effects studied were abrogated in HFD apelin-treated mice with muscle-specific inactive AMPK. Finally, the apelin-stimulated improvement of oxidative capacity led to decreased levels of acylcarnitines and enhanced insulin-stimulated glucose uptake in soleus. Thus, by promoting complete lipid use in muscle of insulin-resistant mice through mitochondrial biogenesis and tighter matching between FAO and the tricarboxylic acid cycle, apelin treatment could contribute to insulin sensitivity improvement. PMID:22210322

  4. Parallel activation of mitochondrial oxidative metabolism with increased cardiac energy expenditure is not dependent on fatty acid oxidation in pigs

    PubMed Central

    Zhou, Lufang; Cabrera, Marco E; Huang, Hazel; Yuan, Celvie L; Monika, Duda K; Sharma, Naveen; Bian, Fang; Stanley, William C

    2007-01-01

    Steady state concentrations of ATP and ADP in vivo are similar at low and high cardiac workloads; however, the mechanisms that regulate the activation of substrate metabolism and oxidative phosphorylation that supports this stability are poorly understood. We tested the hypotheses that (1) there is parallel activation of mitochondrial and cytosolic dehydrogenases in the transition from low to high workload, which increases NADH/NAD+ ratio in both compartments, and (2) this response does not require an increase in fatty acid oxidation (FAO). Anaesthetized pigs were subjected to either sham treatment, or an abrupt increase in cardiac workload for 5 min with dobutamine infusion and aortic constriction. Myocardial oxygen consumption and FAO were increased 3- and 2-fold, respectively, but ATP and ADP concentrations did not change. NADH-generating pathways were rapidly activated in both the cytosol and mitochondria, as seen in a 40% depletion in glycogen stores, a 3.6-fold activation of pyruvate dehydrogenase, and a 50% increase in tissue NADH/NAD+. Simulations from a multicompartmental computational model of cardiac energy metabolism predicted that parallel activation of glycolysis and mitochondrial metabolism results in an increase in the NADH/NAD+ ratio in both cytosol and mitochondria. FAO was blocked by 75% in a third group of pigs, and a similar increase in and the NAHD/NAD+ ratio was observed. In conclusion, in the transition to a high cardiac workload there is rapid parallel activation of substrate oxidation that results in an increase in the NADH/NAD+ ratio. PMID:17185335

  5. Conservative and compensatory evolution in oxidative phosphorylation complexes of angiosperms with highly divergent rates of mitochondrial genome evolution.

    PubMed

    Havird, Justin C; Whitehill, Nicholas S; Snow, Christopher D; Sloan, Daniel B

    2015-12-01

    Interactions between nuclear and mitochondrial gene products are critical for eukaryotic cell function. Nuclear genes encoding mitochondrial-targeted proteins (N-mt genes) experience elevated rates of evolution, which has often been interpreted as evidence of nuclear compensation in response to elevated mitochondrial mutation rates. However, N-mt genes may be under relaxed functional constraints, which could also explain observed increases in their evolutionary rate. To disentangle these hypotheses, we examined patterns of sequence and structural evolution in nuclear