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Sample records for alters mitochondrial activity

  1. Interleukin-15 modulates adipose tissue by altering mitochondrial mass and activity.

    Directory of Open Access Journals (Sweden)

    Nicole G Barra

    Full Text Available Interleukin-15 (IL-15 is an immunomodulatory cytokine that affects body mass regulation independent of lymphocytes; however, the underlying mechanism(s involved remains unknown. In an effort to investigate these mechanisms, we performed metabolic cage studies, assessed intestinal bacterial diversity and macronutrient absorption, and examined adipose mitochondrial activity in cultured adipocytes and in lean IL-15 transgenic (IL-15tg, overweight IL-15 deficient (IL-15-/-, and control C57Bl/6 (B6 mice. Here we show that differences in body weight are not the result of differential activity level, food intake, or respiratory exchange ratio. Although intestinal microbiota differences between obese and lean individuals are known to impact macronutrient absorption, differing gut bacteria profiles in these murine strains does not translate to differences in body weight in colonized germ free animals and macronutrient absorption. Due to its contribution to body weight variation, we examined mitochondrial factors and found that IL-15 treatment in cultured adipocytes resulted in increased mitochondrial membrane potential and decreased lipid deposition. Lastly, IL-15tg mice have significantly elevated mitochondrial activity and mass in adipose tissue compared to B6 and IL-15-/- mice. Altogether, these results suggest that IL-15 is involved in adipose tissue regulation and linked to altered mitochondrial function.

  2. Dysregulation of the Axonal Trafficking of Nuclear-encoded Mitochondrial mRNA alters Neuronal Mitochondrial Activity and Mouse Behavior

    OpenAIRE

    Kar, Amar N.; Sun, Ching-Yu; Reichard, Kathryn; Gervasi, Noreen M.; Pickel, James; Nakazawa, Kazu; Gioio, Anthony E.; Kaplan, Barry B.

    2013-01-01

    Local translation of nuclear-encoded mitochondrial mRNAs is essential for mitochondrial activity, yet there is little insight into the role that axonal trafficking of these transcripts play in neuronal function and behavior. Previously, we identified a 38 nucleotide stem-loop structure (zipcode) in the 3′ untranslated region of the Cytochrome C oxidase IV (COXIV) mRNA that directs the transport of a reporter mRNA to the axon of superior cervical ganglion neurons (SCG). Over-expression of a ch...

  3. Exercise alters liver mitochondria phospholipidomic profile and mitochondrial activity in non-alcoholic steatohepatitis

    OpenAIRE

    Gonçalves, Inês O; Maciel, Elisabete; Passos, Emanuel; Torrella, Joan R.; Rizo, David; Viscor, Ginés; Rocha-Rodrigues, Silvia; Santos-Alves, Estela; Domingues, Maria R.; Oliveira, Paulo J; Ascensão, António; Magalhães, José

    2014-01-01

    Mitochondrial membrane lipid composition is a critical factor in non-alcoholic steatohepatitis (NASH). Exercise is the most prescribed therapeutic strategy against NASH and a potential modulator of lipid membrane. Thus, we aimed to analyze whether physical exercise exerted preventive (voluntary physical activity – VPA) and therapeutic (endurance training – ET) effect on NASH-induced mitochondrial membrane changes. Sprague-Dawley rats (n = 36) were divided into standard-diet sedentary (SS, n =...

  4. CFTR activity and mitochondrial function

    Directory of Open Access Journals (Sweden)

    Angel Gabriel Valdivieso

    2013-01-01

    Full Text Available Cystic Fibrosis (CF is a frequent and lethal autosomal recessive disease, caused by mutations in the gene encoding the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR. Before the discovery of the CFTR gene, several hypotheses attempted to explain the etiology of this disease, including the possible role of a chloride channel, diverse alterations in mitochondrial functions, the overexpression of the lysosomal enzyme α-glucosidase and a deficiency in the cytosolic enzyme glucose 6-phosphate dehydrogenase. Because of the diverse mitochondrial changes found, some authors proposed that the affected gene should codify for a mitochondrial protein. Later, the CFTR cloning and the demonstration of its chloride channel activity turned the mitochondrial, lysosomal and cytosolic hypotheses obsolete. However, in recent years, using new approaches, several investigators reported similar or new alterations of mitochondrial functions in Cystic Fibrosis, thus rediscovering a possible role of mitochondria in this disease. Here, we review these CFTR-driven mitochondrial defects, including differential gene expression, alterations in oxidative phosphorylation, calcium homeostasis, oxidative stress, apoptosis and innate immune response, which might explain some characteristics of the complex CF phenotype and reveals potential new targets for therapy.

  5. Overexpression of mitochondrial sirtuins alters glycolysis and mitochondrial function in HEK293 cells.

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    Michelle Barbi de Moura

    Full Text Available SIRT3, SIRT4, and SIRT5 are mitochondrial deacylases that impact multiple facets of energy metabolism and mitochondrial function. SIRT3 activates several mitochondrial enzymes, SIRT4 represses its targets, and SIRT5 has been shown to both activate and repress mitochondrial enzymes. To gain insight into the relative effects of the mitochondrial sirtuins in governing mitochondrial energy metabolism, SIRT3, SIRT4, and SIRT5 overexpressing HEK293 cells were directly compared. When grown under standard cell culture conditions (25 mM glucose all three sirtuins induced increases in mitochondrial respiration, glycolysis, and glucose oxidation, but with no change in growth rate or in steady-state ATP concentration. Increased proton leak, as evidenced by oxygen consumption in the presence of oligomycin, appeared to explain much of the increase in basal oxygen utilization. Growth in 5 mM glucose normalized the elevations in basal oxygen consumption, proton leak, and glycolysis in all sirtuin over-expressing cells. While the above effects were common to all three mitochondrial sirtuins, some differences between the SIRT3, SIRT4, and SIRT5 expressing cells were noted. Only SIRT3 overexpression affected fatty acid metabolism, and only SIRT4 overexpression altered superoxide levels and mitochondrial membrane potential. We conclude that all three mitochondrial sirtuins can promote increased mitochondrial respiration and cellular metabolism. SIRT3, SIRT4, and SIRT5 appear to respond to excess glucose by inducing a coordinated increase of glycolysis and respiration, with the excess energy dissipated via proton leak.

  6. Overexpression of Mitochondrial Sirtuins Alters Glycolysis and Mitochondrial Function in HEK293 Cells

    Science.gov (United States)

    Barbi de Moura, Michelle; Uppala, Radha; Zhang, Yuxun; Van Houten, Bennett; Goetzman, Eric S.

    2014-01-01

    SIRT3, SIRT4, and SIRT5 are mitochondrial deacylases that impact multiple facets of energy metabolism and mitochondrial function. SIRT3 activates several mitochondrial enzymes, SIRT4 represses its targets, and SIRT5 has been shown to both activate and repress mitochondrial enzymes. To gain insight into the relative effects of the mitochondrial sirtuins in governing mitochondrial energy metabolism, SIRT3, SIRT4, and SIRT5 overexpressing HEK293 cells were directly compared. When grown under standard cell culture conditions (25 mM glucose) all three sirtuins induced increases in mitochondrial respiration, glycolysis, and glucose oxidation, but with no change in growth rate or in steady-state ATP concentration. Increased proton leak, as evidenced by oxygen consumption in the presence of oligomycin, appeared to explain much of the increase in basal oxygen utilization. Growth in 5 mM glucose normalized the elevations in basal oxygen consumption, proton leak, and glycolysis in all sirtuin over-expressing cells. While the above effects were common to all three mitochondrial sirtuins, some differences between the SIRT3, SIRT4, and SIRT5 expressing cells were noted. Only SIRT3 overexpression affected fatty acid metabolism, and only SIRT4 overexpression altered superoxide levels and mitochondrial membrane potential. We conclude that all three mitochondrial sirtuins can promote increased mitochondrial respiration and cellular metabolism. SIRT3, SIRT4, and SIRT5 appear to respond to excess glucose by inducing a coordinated increase of glycolysis and respiration, with the excess energy dissipated via proton leak. PMID:25165814

  7. Diabetes and mitochondrial bioenergetics: Alterations with age

    OpenAIRE

    Ferreira, Fernanda M.; Palmeira, Carlos M.; Seiça, Raquel; Moreno, António J.; Santos, Maria S.

    2003-01-01

    Several studies have been carried out to evaluate the alterations in mitochondrial functions of diabetic rats. However, some of the results reported are controversial, since experimental conditions, such as aging, and/or strain of animals used were different. The purpose of this study was to evaluate the metabolic changes in liver mitochondria, both in the presence of severe hyperglycaemia (STZ-treated rats) and mild hyperglycaemia (Goto-Kakizaki (GK) rats). Moreover, metabolic alterations we...

  8. Altered Mitochondrial Dynamics and TBI Pathophysiology.

    Science.gov (United States)

    Fischer, Tara D; Hylin, Michael J; Zhao, Jing; Moore, Anthony N; Waxham, M Neal; Dash, Pramod K

    2016-01-01

    Mitochondrial function is intimately linked to cellular survival, growth, and death. Mitochondria not only generate ATP from oxidative phosphorylation, but also mediate intracellular calcium buffering, generation of reactive oxygen species (ROS), and apoptosis. Electron leakage from the electron transport chain, especially from damaged or depolarized mitochondria, can generate excess free radicals that damage cellular proteins, DNA, and lipids. Furthermore, mitochondrial damage releases pro-apoptotic factors to initiate cell death. Previous studies have reported that traumatic brain injury (TBI) reduces mitochondrial respiration, enhances production of ROS, and triggers apoptotic cell death, suggesting a prominent role of mitochondria in TBI pathophysiology. Mitochondria maintain cellular energy homeostasis and health via balanced processes of fusion and fission, continuously dividing and fusing to form an interconnected network throughout the cell. An imbalance of these processes, particularly an excess of fission, can be detrimental to mitochondrial function, causing decreased respiration, ROS production, and apoptosis. Mitochondrial fission is regulated by the cytosolic GTPase, dynamin-related protein 1 (Drp1), which translocates to the mitochondrial outer membrane (MOM) to initiate fission. Aberrant Drp1 activity has been linked to excessive mitochondrial fission and neurodegeneration. Measurement of Drp1 levels in purified hippocampal mitochondria showed an increase in TBI animals as compared to sham controls. Analysis of cryo-electron micrographs of these mitochondria also showed that TBI caused an initial increase in the length of hippocampal mitochondria at 24 h post-injury, followed by a significant decrease in length at 72 h. Post-TBI administration of Mitochondrial division inhibitor-1 (Mdivi-1), a pharmacological inhibitor of Drp1, prevented this decrease in mitochondria length. Mdivi-1 treatment also reduced the loss of newborn neurons in the

  9. TNF-alpha-induced mitochondrial alterations in human T cells requires FADD and caspase-8 activation but not RIP and caspase-3 activation.

    Science.gov (United States)

    Shakibaei, Mehdi; Sung, Bokyung; Sethi, Gautam; Aggarwal, Bharat B

    2010-09-15

    Although much is known about how TNF-alpha induces apoptosis in the presence of inhibitors of protein synthesis, little is known about how it induces apoptosis without these inhibitors. In this report we investigated temporal sequence of events induced by TNF-alpha in the absence of protein synthesis. Regardless of whether we measured the effects by plasma membrane phosphotidylserine accumulation, by DNA strand breaks, or activation of caspases, significant changes were observed only between 12-24 h of TNF-alpha treatment. One of the earliest changes observed after TNF-alpha treatment was mitochondrial swelling at 10 min; followed by cytochrome c and Smac release at 10-30 min, and then heterochromatin clumping occurred at 60 min. While genetic deletion of receptor-interaction protein (RIP) had no effect on TNF-alpha-induced mitochondrial damage, deletion of Fas-associated death domain (FADD) abolished the TNF-induced mitochondrial swelling. Since pan-caspase inhibitor z-VAD-fmk abolished the TNF-alpha-induced mitochondrial changes, z-DEVD-fmk, an inhibitor of caspase-3 had no effect, suggesting that TNF-alpha-induced mitochondrial changes or cytochrome c and Smac release requires caspase-8 but not caspase-3 activation. Overall, our results indicated that mitochondrial changes are early events in TNF-alpha-induced apoptosis and that these mitochondrial changes require recruitment of FADD and caspase-8 activation, but not caspase-3 activation or RIP recruitment. PMID:20136500

  10. Altered Mitochondrial Dynamics and TBI Pathophysiology

    Directory of Open Access Journals (Sweden)

    Tara Diane Fischer

    2016-03-01

    Full Text Available Mitochondrial function is intimately linked to cellular survival, growth, and death. Mitochondria not only generate ATP from oxidative phosphorylation, but also mediate intracellular calcium buffering, generation of reactive oxygen species (ROS, and apoptosis. Electron leakage from the electron transport chain, especially from damaged or depolarized mitochondria, can generate excess free radicals that damage cellular proteins, DNA, and lipids. Furthermore, mitochondrial damage releases pro-apoptotic factors to initiate cell death. Previous studies have reported that traumatic brain injury (TBI reduces mitochondrial respiration, enhances production of ROS, and triggers apoptotic cell death, suggesting a prominent role of mitochondria in TBI pathophysiology. Mitochondria maintain cellular energy homeostasis and health via balanced processes of fusion and fission, continuously dividing and fusing to form an interconnected network throughout the cell. An imbalance of these processes, particularly an excess of fission, can be detrimental to mitochondrial function, causing decreased respiration, ROS production, and apoptosis. Mitochondrial fission is regulated by the cytosolic GTPase, dynamin-related protein 1 (Drp1, which translocates to the mitochondrial outer membrane to initiate fission. Aberrant Drp1 activity has been linked to excessive mitochondrial fission and neurodegeneration. Measurement of Drp1 levels in purified hippocampal mitochondria showed an increase in TBI animals as compared to sham controls. Analysis of cryo-electron micrographs of these mitochondria also showed that TBI caused an initial increase in the length of hippocampal mitochondria at 24 hours post-injury, followed by a significant decrease in length at 72 hours. Post-TBI administration of Mdivi-1, a pharmacological inhibitor of Drp1, prevented this decrease in mitochondria length. Mdivi-1 treatment also reduced the loss of newborn neurons in the hippocampus and improved

  11. Altered brain energetics induces mitochondrial fission arrest in Alzheimer's Disease.

    Science.gov (United States)

    Zhang, Liang; Trushin, Sergey; Christensen, Trace A; Bachmeier, Benjamin V; Gateno, Benjamin; Schroeder, Andreas; Yao, Jia; Itoh, Kie; Sesaki, Hiromi; Poon, Wayne W; Gylys, Karen H; Patterson, Emily R; Parisi, Joseph E; Diaz Brinton, Roberta; Salisbury, Jeffrey L; Trushina, Eugenia

    2016-01-01

    Altered brain metabolism is associated with progression of Alzheimer's Disease (AD). Mitochondria respond to bioenergetic changes by continuous fission and fusion. To account for three dimensional architecture of the brain tissue and organelles, we applied 3-dimensional electron microscopy (3D EM) reconstruction to visualize mitochondrial structure in the brain tissue from patients and mouse models of AD. We identified a previously unknown mitochondrial fission arrest phenotype that results in elongated interconnected organelles, "mitochondria-on-a-string" (MOAS). Our data suggest that MOAS formation may occur at the final stages of fission process and was not associated with altered translocation of activated dynamin related protein 1 (Drp1) to mitochondria but with reduced GTPase activity. Since MOAS formation was also observed in the brain tissue of wild-type mice in response to hypoxia or during chronological aging, fission arrest may represent fundamental compensatory adaptation to bioenergetic stress providing protection against mitophagy that may preserve residual mitochondrial function. The discovery of novel mitochondrial phenotype that occurs in the brain tissue in response to energetic stress accurately detected only using 3D EM reconstruction argues for a major role of mitochondrial dynamics in regulating neuronal survival. PMID:26729583

  12. The order of exercise during concurrent training for rehabilitation does not alter acute genetic expression, mitochondrial enzyme activity or improvements in muscle function.

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    Lauren G MacNeil

    Full Text Available Concurrent exercise combines different modes of exercise (e.g., aerobic and resistance into one training protocol, providing stimuli meant to increase muscle strength, aerobic capacity and mass. As disuse is associated with decrements in strength, aerobic capacity and muscle size concurrent training is an attractive modality for rehabilitation. However, interference between the signaling pathways may result in preferential improvements for one of the exercise modes. We recruited 18 young adults (10 ♂, 8 ♀ to determine if order of exercise mode during concurrent training would differentially affect gene expression, protein content and measures of strength and aerobic capacity after 2 weeks of knee-brace induced disuse. Concurrent exercise sessions were performed 3x/week for 6 weeks at gradually increasing intensities either with endurance exercise preceding (END>RES or following (RES>END resistance exercise. Biopsies were collected from the vastus lateralis before, 3 h after the first exercise bout and 48 h after the end of training. Concurrent exercise altered the expression of genes involved in mitochondrial biogenesis (PGC-1α, PRC, PPARγ, hypertrophy (PGC-1α4, REDD2, Rheb and atrophy (MuRF-1, Runx1, increased electron transport chain complex protein content, citrate synthase and mitochondrial cytochrome c oxidase enzyme activity, muscle mass, maximum isometric strength and VO 2peak. However, the order in which exercise was completed (END>RES or RES>END only affected the protein content of mitochondrial complex II subunit. In conclusion, concurrent exercise training is an effective modality for the rehabilitation of the loss of skeletal muscle mass, maximum strength, and peak aerobic capacity resulting from disuse, regardless of the order in which the modes of exercise are performed.

  13. Hypoxia/oxidative stress alters the pharmacokinetics of CPU86017-RS through mitochondrial dysfunction and NADPH oxidase activation

    OpenAIRE

    Gao, Jie; Ding, Xuan-Sheng; Zhang, Yu-mao; Dai, De-zai; Liu, Mei; Zhang, Can; Dai, Yin

    2013-01-01

    Aim: Hypoxia/oxidative stress can alter the pharmacokinetics (PK) of CPU86017-RS, a novel antiarrhythmic agent. The aim of this study was to investigate the mechanisms underlying the alteration of PK of CPU86017-RS by hypoxia/oxidative stress. Methods: Male SD rats exposed to normal or intermittent hypoxia (10% O2) were administered CPU86017-RS (20, 40 or 80 mg/kg, ig) for 8 consecutive days. The PK parameters of CPU86017-RS were examined on d 8. In a separate set of experiments, female SD ra...

  14. Defective mitochondrial respiration, altered dNTP pools and reduced AP endonuclease 1 activity in peripheral blood mononuclear cells of Alzheimer's disease patients

    DEFF Research Database (Denmark)

    Maynard, Scott; Hejl, Anne-Mette; Dinh, Tran Thuan Son;

    2015-01-01

    AIMS: Accurate biomarkers for early diagnosis of Alzheimer's disease (AD) are badly needed. Recent reports suggest that dysfunctional mitochondria and DNA damage are associated with AD development. In this report, we measured various cellular parameters, related to mitochondrial bioenergetics and...... as possible. We measured glycolysis and mitochondrial respiration fluxes using the Seahorse Bioscience flux analyzer, mitochondrial ROS production using flow cytometry, dNTP levels by way of a DNA polymerization assay, DNA strand breaks using the Fluorometric detection of Alkaline DNA Unwinding (FADU......) assay, and APE1 incision activity (in cell lysates) on a DNA substrate containing an AP site (to estimate DNA repair efficiency). RESULTS: In the PBMCs of AD patients, we found reduced basal mitochondrial oxygen consumption, reduced proton leak, higher dATP level, and lower AP endonuclease 1 activity...

  15. Altered mitochondrial regulation in quadriceps muscles of patients with COPD

    DEFF Research Database (Denmark)

    Naimi, Ashley I; Bourbeau, Jean; Perrault, Helene;

    2011-01-01

    Evidence exists for locomotor muscle impairment in patients with chronic obstructive pulmonary disease (COPD), including fiber type alterations and reduced mitochondrial oxidative capacity. In this study high-resolution respirometry was used to quantify oxygen flux in permeabilized fibres from...... only ~50% that of control subjects. These results indicate that quadriceps muscle mitochondrial function is altered in patients with COPD. The regulatory mechanisms underlying these functional abnormalities remain to be uncovered....

  16. Mitochondrial DNA haplogroups modify the risk of osteoarthritis by altering mitochondrial function and intracellular mitochondrial signals.

    Science.gov (United States)

    Fang, Hezhi; Zhang, Fengjiao; Li, Fengjie; Shi, Hao; Ma, Lin; Du, Miaomiao; You, Yanting; Qiu, Ruyi; Nie, Hezhongrong; Shen, Lijun; Bai, Yidong; Lyu, Jianxin

    2016-04-01

    Haplogroup G predisposes one to an increased risk of osteoarthritis (OA) occurrence, while haplogroup B4 is a protective factor against OA onset. However, the underlying mechanism is not known. Here, by using trans-mitochondrial technology, we demonstrate that the activity levels of mitochondrial respiratory chain complex I and III are higher in G cybrids than in haplogroup B4. Increased mitochondrial oxidative phosphorylation (OXPHOS) promotes mitochondrial-related ATP generation in G cybrids, thereby shifting the ATP generation from glycolysis to OXPHOS. Furthermore, we found that lower glycolysis in G cybrids decreased cell viability under hypoxia (1% O2) compared with B4 cybrids. In contrast, G cybrids have a lower NAD(+)/NADH ratio and less generation of reactive oxygen species (ROS) under both hypoxic (1% O2) and normoxic (20% O2) conditions than B4 cybrids, indicating that mitochondrial-mediated signaling pathways (retrograde signaling) differ between these cybrids. Gene expression profiling of G and B4 cybrids using next-generation sequencing technology showed that 404 of 575 differentially expressed genes (DEGs) between G and B4 cybrids are enriched in 17 pathways, of which 11 pathways participate in OA. Quantitative reverse transcription PCR (qRT-PCR) analyses confirmed that G cybrids had lower glycolysis activity than B4 cybrids. In addition, we confirmed that the rheumatoid arthritis pathway was over-activated in G cybrids, although the remaining 9 pathways were not further tested by qRT-PCR. In conclusion, our findings indicate that mtDNA haplogroup G may increase the risk of OA by shifting the metabolic profile from glycolysis to OXPHOS and by over-activating OA-related signaling pathways. PMID:26705675

  17. Insulin-like growth factor induced signals activate mitochondrial respiration

    OpenAIRE

    Hütter, E.; Unterluggauer, H.; Viertler, H.P.; Jansen-Dürr, P

    2008-01-01

    From experiments with lower eukaryotes it is known that the metabolic rate and also the rate of aging are tightly controlled by the IGF / insulin signal transduction pathway. The mitochondrial theory of aging implies that an increased metabolic rate leads to increased mitochondrial activity; increased production of reactive oxygen species due to these alterations would speed up the aging process. To address the question if mitochondrial activity is influenced by insulin / IGF signalling, we h...

  18. Activation-induced spatiotemporal cerebral blood flow changes and behavioral deficit after developmental mTBI in rats can be favorably altered by facilitating mitochondrial calcium uptake

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    Madhuvika eMurugan

    2016-03-01

    Full Text Available Mild to moderate traumatic brain injury (mTBI leads to secondary neuronal loss via excitotoxic mechanisms, including mitochondrial Ca2+ overload. However in the surviving cellular population, mitochondrial Ca2+ influx and oxidative metabolism are diminished leading to suboptimal neuronal circuit activity and poor prognosis. Hence we tested the impact of boosting neuronal electrical activity and oxidative metabolism by facilitating mitochondrial Ca2+ uptake in a rat model of mTBI. In developing rats (P25-P26 sustaining an mTBI, we demonstrate post-traumatic changes in cerebral blood flow (CBF in the sensorimotor cortex in response to whisker stimulation compared to sham using functional Laser Doppler Imaging (fLDI at adulthood (P67-P73. Compared to sham, whisker stimulation-evoked positive CBF responses decreased while negative CBF responses increased in the mTBI animals. The spatiotemporal CBF changes representing underlying neuronal activity suggested profound changes to neurovascular activity after mTBI. Behavioral assessment of the same cohort of animals prior to fLDI showed that mTBI resulted in persistent contralateral sensorimotor behavioral deficit along with ipsilateral neuronal loss compared to sham. Treating mTBI rats with Kaempferol, a dietary flavonol compound that enhanced mitochondrial Ca2+ uptake, eliminated the inter-hemispheric asymmetry in the whisker stimulation-induced positive CBF responses and the ipsilateral negative CBF responses otherwise observed in the untreated and vehicle-treated mTBI animals in adulthood. Kaempferol also improved somatosensory behavioral measures compared to untreated and vehicle treated mTBI animals without augmenting post-injury neuronal loss. The results indicate that reduced mitochondrial Ca2+ uptake in the surviving populations affect post-traumatic neural activation leading to persistent behavioral deficits. Improvement in sensorimotor behavior and spatiotemporal neurovascular activity

  19. Alterations in mitochondrial electron transport system activity in response to warm acclimation, hypoxia-reoxygenation and copper in rainbow trout, Oncorhynchus mykiss

    Energy Technology Data Exchange (ETDEWEB)

    Sappal, Ravinder [Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, C1A 4P3 (Canada); Department of Biomedical Sciences, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, C1A 4P3 (Canada); MacDougald, Michelle [Faculty of Medicine, Memorial University of Newfoundland, Health Sciences Centre, Prince Philip Drive, St. John’s, NL, A1B 3V6 (Canada); Fast, Mark [Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, C1A 4P3 (Canada); Stevens, Don [Department of Biomedical Sciences, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, C1A 4P3 (Canada); Kibenge, Fred [Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, C1A 4P3 (Canada); Siah, Ahmed [British Columbia Centre for Aquatic Health Sciences, 871A Island Highway, Campbell River, BC, V9W 2C2 (Canada); Kamunde, Collins, E-mail: ckamunde@upei.ca [Department of Biomedical Sciences, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, C1A 4P3 (Canada)

    2015-08-15

    Highlights: • Sequential inhibition and activation allows assessment of multiple segments of the electron transport system. • Warm acclimation and hypoxia-reoxygenation have global effects on the electron transport system. • Warm acclimation and hypoxia-reoxygenation sensitize the electron transport system to copper. • Thermal stress, hypoxia-reoxygenation and copper act additively to impair mitochondrial function. - Abstract: Fish expend significant amounts of energy to handle the numerous potentially stressful biotic and abiotic factors that they commonly encounter in aquatic environments. This universal requirement for energy singularizes mitochondria, the primary cellular energy transformers, as fundamental drivers of responses to environmental change. Our study probed the interacting effects of thermal stress, hypoxia-reoxygenation (HRO) and copper (Cu) exposure in rainbow trout to test the prediction that they act jointly to impair mitochondrial function. Rainbow trout were acclimated to 11 (controls) or 20 °C for 2 months. Liver mitochondria were then isolated and their responses in vitro to Cu (0–20 μM) without and with HRO were assessed. Sequential inhibition and activation of mitochondrial electron transport system (ETS) enzyme complexes permitted the measurement of respiratory activities supported by complex I–IV (CI–IV) in one run. The results showed that warm acclimation reduced fish and liver weights but increased mitochondrial protein indicating impairment of energy metabolism, increased synthesis of defense proteins and/or reduced liver water content. Whereas acute rise (11 → 20 °C) in temperature increased mitochondrial oxidation rates supported by CI–IV, warm acclimation reduced the maximal (state 3) and increased the basal (state 4) respiration leading to global uncoupling of oxidative phosphorylation (OXPHOS). HRO profoundly inhibited both maximal and basal respiration rates supported by CI–IV, reduced RCR for all except

  20. Alterations in mitochondrial electron transport system activity in response to warm acclimation, hypoxia-reoxygenation and copper in rainbow trout, Oncorhynchus mykiss

    International Nuclear Information System (INIS)

    Highlights: • Sequential inhibition and activation allows assessment of multiple segments of the electron transport system. • Warm acclimation and hypoxia-reoxygenation have global effects on the electron transport system. • Warm acclimation and hypoxia-reoxygenation sensitize the electron transport system to copper. • Thermal stress, hypoxia-reoxygenation and copper act additively to impair mitochondrial function. - Abstract: Fish expend significant amounts of energy to handle the numerous potentially stressful biotic and abiotic factors that they commonly encounter in aquatic environments. This universal requirement for energy singularizes mitochondria, the primary cellular energy transformers, as fundamental drivers of responses to environmental change. Our study probed the interacting effects of thermal stress, hypoxia-reoxygenation (HRO) and copper (Cu) exposure in rainbow trout to test the prediction that they act jointly to impair mitochondrial function. Rainbow trout were acclimated to 11 (controls) or 20 °C for 2 months. Liver mitochondria were then isolated and their responses in vitro to Cu (0–20 μM) without and with HRO were assessed. Sequential inhibition and activation of mitochondrial electron transport system (ETS) enzyme complexes permitted the measurement of respiratory activities supported by complex I–IV (CI–IV) in one run. The results showed that warm acclimation reduced fish and liver weights but increased mitochondrial protein indicating impairment of energy metabolism, increased synthesis of defense proteins and/or reduced liver water content. Whereas acute rise (11 → 20 °C) in temperature increased mitochondrial oxidation rates supported by CI–IV, warm acclimation reduced the maximal (state 3) and increased the basal (state 4) respiration leading to global uncoupling of oxidative phosphorylation (OXPHOS). HRO profoundly inhibited both maximal and basal respiration rates supported by CI–IV, reduced RCR for all except

  1. Somatic alterations in mitochondrial DNA and mitochondrial dysfunction in gastric cancer progression.

    Science.gov (United States)

    Lee, Hsin-Chen; Huang, Kuo-Hung; Yeh, Tien-Shun; Chi, Chin-Wen

    2014-04-14

    Energy metabolism reprogramming was recently identified as one of the cancer hallmarks. One of the underlying mechanisms of energy metabolism reprogramming is mitochondrial dysfunction caused by mutations in nuclear genes or mitochondrial DNA (mtDNA). In the past decades, several types of somatic mtDNA alterations have been identified in gastric cancer. However, the role of these mtDNA alterations in gastric cancer progression remains unclear. In this review, we summarize recently identified somatic mtDNA alterations in gastric cancers as well as the relationship between these alterations and the clinicopathological features of gastric cancer. The causative factors and potential roles of the somatic mtDNA alterations in cancer progression are also discussed. We suggest that point mutations and mtDNA copy number decreases are the two most common mtDNA alterations that result in mitochondrial dysfunction in gastric cancers. The two primary mutation types (transition mutations and mononucleotide or dinucleotide repeat instability) imply potential causative factors. Mitochondrial dysfunction-generated reactive oxygen species may be involved in the malignant changes of gastric cancer. The search for strategies to prevent mtDNA alterations and inhibit the mitochondrial retrograde signaling will benefit the development of novel treatments for gastric cancer and other malignancies. PMID:24744584

  2. CFTR activity and mitochondrial function

    OpenAIRE

    Angel Gabriel Valdivieso; Santa-Coloma, Tomás A.

    2013-01-01

    Cystic Fibrosis (CF) is a frequent and lethal autosomal recessive disease, caused by mutations in the gene encoding the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR). Before the discovery of the CFTR gene, several hypotheses attempted to explain the etiology of this disease, including the possible role of a chloride channel, diverse alterations in mitochondrial functions, the overexpression of the lysosomal enzyme α-glucosidase and a deficiency in the cytosolic enzyme glucose 6-p...

  3. Reduced Mitochondrial Function in Human Huntington Disease Lymphoblasts is Not Due to Alterations in Cardiolipin Metabolism or Mitochondrial Supercomplex Assembly.

    Science.gov (United States)

    Mejia, Edgard M; Chau, Sarah; Sparagna, Genevieve C; Sipione, Simonetta; Hatch, Grant M

    2016-05-01

    Huntington's Disease (HD) is an autosomal dominant disease that occurs as a result of expansion of the trinucleotide repeat CAG (glutamine) on the HTT gene. HD patients exhibit various forms of mitochondrial dysfunction within neurons and peripheral tissues. Cardiolipin (Ptd2Gro) is a polyglycerophospholipid found exclusively in mitochondria and is important for maintaining mitochondrial function. We examined if altered Ptd2Gro metabolism was involved in the mitochondrial dysfunction associated with HD. Mitochondrial basal respiration, spare respiratory capacity, ATP coupling efficiency and rate of glycolysis were markedly diminished in Epstein-Barr virus transformed HD lymphoblasts compared to controls (CTRL). Mitochondrial supercomplex formation and Complex I activity within these supercomplexes did not vary between HD patients with different length of CAG repeats and appeared unaltered compared to CTRL. In contrast, in vitro Complex I enzyme activity in mitochondrial enriched samples was reduced in HD lymphoblasts compared to CTRL. The total cellular pool size of Ptd2Gro and its synthesis/remodeling from [(3)H]acetate/[(14)C]oleate were unaltered in HD lymphoblasts compared to CTRL. In addition, the molecular species of Ptd2Gro were essentially unaltered in HD lymphoblasts compared to CTRL. We conclude that compared to CTRL lymphoblasts, HD lymphoblasts display impaired mitochondrial basal respiration, spare respiratory capacity, ATP coupling efficiency and rate of glycolysis with any pathological CAG repeat length, but this is not due to alterations in Ptd2Gro metabolism. We suggest that HD patient lymphoblasts may be a useful model to study defective energy metabolism that does not involve alterations in Ptd2Gro metabolism. PMID:26846325

  4. Data for mitochondrial proteomic alterations in the developing rat brain.

    Science.gov (United States)

    Villeneuve, Lance M; Stauch, Kelly L; Fox, Howard S

    2014-12-01

    Mitochondria are a critical organelle involved in many cellular processes, and due to the nature of the brain, neuronal cells are almost completely reliant on these organelles for energy generation. Due to the fact that biomedical research tends to investigate disease state pathogenesis, one area of mitochondrial research commonly overlooked is homeostatic responses to energy demands. Therefore, to elucidate mitochondrial alterations occurring during the developmentally important phase of E18 to P7 in the brain, we quantified the proteins in the mitochondrial proteome as well as proteins interacting with the mitochondria. We identified a large number of significantly altered proteins involved in a variety of pathways including glycolysis, mitochondrial trafficking, mitophagy, and the unfolded protein response. These results are important because we identified alterations thought to be homeostatic in nature occurring within mitochondria, and these results may be used to identify any abnormal deviations in the mitochondrial proteome occurring during this period of brain development. A more comprehensive analysis of this data may be obtained from the article "Proteomic analysis of mitochondria from embryonic and postnatal rat brains reveals response to developmental changes in energy demands" in the Journal of Proteomics. PMID:26217684

  5. Muscle biopsies from human muscle diseases with myopathic pathology reveal common alterations in mitochondrial function.

    Science.gov (United States)

    Sunitha, Balaraju; Gayathri, Narayanappa; Kumar, Manish; Keshava Prasad, Thottethodi Subrahmanya; Nalini, Atchayaram; Padmanabhan, Balasundaram; Srinivas Bharath, Muchukunte Mukunda

    2016-07-01

    Muscle diseases are clinically and genetically heterogeneous and manifest as dystrophic, inflammatory and myopathic pathologies, among others. Our previous study on the cardiotoxin mouse model of myodegeneration and inflammation linked muscle pathology with mitochondrial damage and oxidative stress. In this study, we investigated whether human muscle diseases display mitochondrial changes. Muscle biopsies from muscle disease patients, represented by dysferlinopathy (dysfy) (dystrophic pathology; n = 43), polymyositis (PM) (inflammatory pathology; n = 24), and distal myopathy with rimmed vacuoles (DMRV) (distal myopathy; n = 31) were analyzed. Mitochondrial damage (ragged blue and COX-deficient fibers) was revealed in dysfy, PM, and DMRV cases by enzyme histochemistry (SDH and COX-SDH), electron microscopy (vacuolation and altered cristae) and biochemical assays (significantly increased ADP/ATP ratio). Proteomic analysis of muscle mitochondria from all three muscle diseases by isobaric tag for relative and absolute quantitation labeling and liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis demonstrated down-regulation of electron transport chain (ETC) complex subunits, assembly factors and Krebs cycle enzymes. Interestingly, 80 of the under-expressed proteins were common among the three pathologies. Assay of ETC and Krebs cycle enzyme activities validated the MS data. Mitochondrial proteins from muscle pathologies also displayed higher tryptophan (Trp) oxidation and the same was corroborated in the cardiotoxin model. Molecular modeling predicted Trp oxidation to alter the local structure of mitochondrial proteins. Our data highlight mitochondrial alterations in muscle pathologies, represented by morphological changes, altered mitochondrial proteome and protein oxidation, thereby establishing the role of mitochondrial damage in human muscle diseases. We investigated whether human muscle diseases display mitochondrial changes. Muscle biopsies

  6. Polyglutamine toxicity in yeast induces metabolic alterations and mitochondrial defects

    KAUST Repository

    Papsdorf, Katharina

    2015-09-03

    Background Protein aggregation and its pathological effects are the major cause of several neurodegenerative diseases. In Huntington’s disease an elongated stretch of polyglutamines within the protein Huntingtin leads to increased aggregation propensity. This induces cellular defects, culminating in neuronal loss, but the connection between aggregation and toxicity remains to be established. Results To uncover cellular pathways relevant for intoxication we used genome-wide analyses in a yeast model system and identify fourteen genes that, if deleted, result in higher polyglutamine toxicity. Several of these genes, like UGO1, ATP15 and NFU1 encode mitochondrial proteins, implying that a challenged mitochondrial system may become dysfunctional during polyglutamine intoxication. We further employed microarrays to decipher the transcriptional response upon polyglutamine intoxication, which exposes an upregulation of genes involved in sulfur and iron metabolism and mitochondrial Fe-S cluster formation. Indeed, we find that in vivo iron concentrations are misbalanced and observe a reduction in the activity of the prominent Fe-S cluster containing protein aconitase. Like in other yeast strains with impaired mitochondria, non-fermentative growth is impossible after intoxication with the polyglutamine protein. NMR-based metabolic analyses reveal that mitochondrial metabolism is reduced, leading to accumulation of metabolic intermediates in polyglutamine-intoxicated cells. Conclusion These data show that damages to the mitochondrial system occur in polyglutamine intoxicated yeast cells and suggest an intricate connection between polyglutamine-induced toxicity, mitochondrial functionality and iron homeostasis in this model system.

  7. TNF-α-Induced Mitochondrial Alterations in Human T Cells Requires FADD and Caspase-8 Activation but Not RIP and Caspase-3 Activation

    OpenAIRE

    Shakibaei, Mehdi; Sung, Bokyung; Sethi, Gautam; Aggarwal, Bharat B.

    2010-01-01

    Although much is known about how TNF-α induces apoptosis in the presence of inhibitors of protein synthesis, little is known about how it induces apoptosis without these inhibitors. In this report we investigated temporal sequence of events induced by TNF-α in the absence of protein synthesis. Regardless of whether we measured the effects by plasma membrane phosphotidylserine accumulation, by DNA strand breaks, or activation of caspases, significant changes were observed only between 12–24 h ...

  8. Alterations of mitochondrial dynamics allow retrograde propagation of locally initiated axonal insults.

    Science.gov (United States)

    Lassus, Benjamin; Magifico, Sebastien; Pignon, Sandra; Belenguer, Pascale; Miquel, Marie-Christine; Peyrin, Jean-Michel

    2016-01-01

    In chronic neurodegenerative syndromes, neurons progressively die through a generalized retraction pattern triggering retrograde axonal degeneration toward the cell bodies, which molecular mechanisms remain elusive. Recent observations suggest that direct activation of pro-apoptotic signaling in axons triggers local degenerative events associated with early alteration of axonal mitochondrial dynamics. This raises the question of the role of mitochondrial dynamics on both axonal vulnerability stress and their implication in the spreading of damages toward unchallenged parts of the neuron. Here, using microfluidic chambers, we assessed the consequences of interfering with OPA1 and DRP1 proteins on axonal degeneration induced by local application of rotenone. We found that pharmacological inhibition of mitochondrial fission prevented axonal damage induced by rotenone, in low glucose conditions. While alteration of mitochondrial dynamics per se did not lead to spontaneous axonal degeneration, it dramatically enhanced axonal vulnerability to rotenone, which had no effect in normal glucose conditions, and promoted retrograde spreading of axonal degeneration toward the cell body. Altogether, our results suggest a mitochondrial priming effect in axons as a key process of axonal degeneration. In the context of neurodegenerative diseases, like Parkinson's and Alzheimer's, mitochondria fragmentation could hasten neuronal death and initiate spatial dispersion of locally induced degenerative events. PMID:27604820

  9. Altered Glycolysis and Mitochondrial Respiration in a Zebrafish Model of Dravet Syndrome.

    Science.gov (United States)

    Kumar, Maneesh G; Rowley, Shane; Fulton, Ruth; Dinday, Matthew T; Baraban, Scott C; Patel, Manisha

    2016-01-01

    Altered metabolism is an important feature of many epileptic syndromes but has not been reported in Dravet syndrome (DS), a catastrophic childhood epilepsy associated with mutations in a voltage-activated sodium channel, Nav1.1 (SCN1A). To address this, we developed novel methodology to assess real-time changes in bioenergetics in zebrafish larvae between 4 and 6 d postfertilization (dpf). Baseline and 4-aminopyridine (4-AP) stimulated glycolytic flux and mitochondrial respiration were simultaneously assessed using a Seahorse Biosciences extracellular flux analyzer. Scn1Lab mutant zebrafish showed a decrease in baseline glycolytic rate and oxygen consumption rate (OCR) compared to controls. A ketogenic diet formulation rescued mutant zebrafish metabolism to control levels. Increasing neuronal excitability with 4-AP resulted in an immediate increase in glycolytic rates in wild-type zebrafish, whereas mitochondrial OCR increased slightly and quickly recovered to baseline values. In contrast, scn1Lab mutant zebrafish showed a significantly slower and exaggerated increase of both glycolytic rates and OCR after 4-AP. The underlying mechanism of decreased baseline OCR in scn1Lab mutants was not because of altered mitochondrial DNA content or dysfunction of enzymes in the electron transport chain or tricarboxylic acid cycle. Examination of glucose metabolism using a PCR array identified five glycolytic genes that were downregulated in scn1Lab mutant zebrafish. Our findings in scn1Lab mutant zebrafish suggest that glucose and mitochondrial hypometabolism contribute to the pathophysiology of DS. PMID:27066534

  10. Altered Glycolysis and Mitochondrial Respiration in a Zebrafish Model of Dravet Syndrome123

    Science.gov (United States)

    Kumar, Maneesh G.; Rowley, Shane; Fulton, Ruth; Dinday, Matthew T.; Baraban, Scott C.

    2016-01-01

    Abstract Altered metabolism is an important feature of many epileptic syndromes but has not been reported in Dravet syndrome (DS), a catastrophic childhood epilepsy associated with mutations in a voltage-activated sodium channel, Nav1.1 (SCN1A). To address this, we developed novel methodology to assess real-time changes in bioenergetics in zebrafish larvae between 4 and 6 d postfertilization (dpf). Baseline and 4-aminopyridine (4-AP) stimulated glycolytic flux and mitochondrial respiration were simultaneously assessed using a Seahorse Biosciences extracellular flux analyzer. Scn1Lab mutant zebrafish showed a decrease in baseline glycolytic rate and oxygen consumption rate (OCR) compared to controls. A ketogenic diet formulation rescued mutant zebrafish metabolism to control levels. Increasing neuronal excitability with 4-AP resulted in an immediate increase in glycolytic rates in wild-type zebrafish, whereas mitochondrial OCR increased slightly and quickly recovered to baseline values. In contrast, scn1Lab mutant zebrafish showed a significantly slower and exaggerated increase of both glycolytic rates and OCR after 4-AP. The underlying mechanism of decreased baseline OCR in scn1Lab mutants was not because of altered mitochondrial DNA content or dysfunction of enzymes in the electron transport chain or tricarboxylic acid cycle. Examination of glucose metabolism using a PCR array identified five glycolytic genes that were downregulated in scn1Lab mutant zebrafish. Our findings in scn1Lab mutant zebrafish suggest that glucose and mitochondrial hypometabolism contribute to the pathophysiology of DS. PMID:27066534

  11. Mitochondrial Morphology and Fundamental Parameters of the Mitochondrial Respiratory Chain Are Altered in Caenorhabditis elegans Strains Deficient in Mitochondrial Dynamics and Homeostasis Processes

    Science.gov (United States)

    Luz, Anthony L.; Rooney, John P.; Kubik, Laura L.; Gonzalez, Claudia P.; Song, Dong Hoon; Meyer, Joel N.

    2015-01-01

    Mitochondrial dysfunction has been linked to myriad human diseases and toxicant exposures, highlighting the need for assays capable of rapidly assessing mitochondrial health in vivo. Here, using the Seahorse XFe24 Analyzer and the pharmacological inhibitors dicyclohexylcarbodiimide and oligomycin (ATP-synthase inhibitors), carbonyl cyanide 4-(trifluoromethoxy) phenylhydrazone (mitochondrial uncoupler) and sodium azide (cytochrome c oxidase inhibitor), we measured the fundamental parameters of mitochondrial respiratory chain function: basal oxygen consumption, ATP-linked respiration, maximal respiratory capacity, spare respiratory capacity and proton leak in the model organism Caenhorhabditis elegans. Since mutations in mitochondrial homeostasis genes cause mitochondrial dysfunction and have been linked to human disease, we measured mitochondrial respiratory function in mitochondrial fission (drp-1)-, fusion (fzo-1)-, mitophagy (pdr-1, pink-1)-, and electron transport chain complex III (isp-1)-deficient C. elegans. All showed altered function, but the nature of the alterations varied between the tested strains. We report increased basal oxygen consumption in drp-1; reduced maximal respiration in drp-1, fzo-1, and isp-1; reduced spare respiratory capacity in drp-1 and fzo-1; reduced proton leak in fzo-1 and isp-1; and increased proton leak in pink-1 nematodes. As mitochondrial morphology can play a role in mitochondrial energetics, we also quantified the mitochondrial aspect ratio for each mutant strain using a novel method, and for the first time report increased aspect ratios in pdr-1- and pink-1-deficient nematodes. PMID:26106885

  12. Multiple mitochondrial alterations in a case of myopathy.

    Science.gov (United States)

    Fujioka, H; Tandler, B; Cohen, M; Koontz, D; Hoppel, C L

    2014-05-01

    Mitochondrial alterations are the most common feature of human myopathies. A biopsy of quadriceps muscle from a 50-year-old woman exhibiting myopathic symptoms was examined by transmission electron microscopy. Biopsied fibers from quadriceps muscle displayed numerous subsarcolemmal mitochondria that contained crystalloids. Numbering 1-6 per organelle, these consisted of rows of punctuate densities measuring ∼0.34 nm; the parallel rows of these dots had a periodicity of ∼0.8 nm. The crystalloids were ensconced within cristae or in the outer compartment. Some mitochondria without crystalloids had circumferential cristae, leaving a membrane-free center that was filled with a farinaceous material. Other scattered fibrocyte defects included disruption of the contractile apparatus or its sporadic replacement by a finely punctuate material in some myofibers. Intramitochondrial crystalloids, although morphologically striking, do not impair organelle physiology to a significant degree, so the muscle weakness of the patient must originate elsewhere. PMID:24579828

  13. Altered Mitochondrial Function, Mitochondrial DNA and Reduced Metabolic Flexibility in Patients With Diabetic Nephropathy

    Directory of Open Access Journals (Sweden)

    Anna Czajka

    2015-06-01

    Full Text Available The purpose of this study was to determine if mitochondrial dysfunction plays a role in diabetic nephropathy (DN, a kidney disease which affects >100 million people worldwide and is a leading cause of renal failure despite therapy. A cross-sectional study comparing DN with diabetes patients without kidney disease (DC and healthy controls (HCs; and renal mesangial cells (HMCs grown in normal and high glucose, was carried out. Patients with diabetes (DC had increased circulating mitochondrial DNA (MtDNA, and HMCs increased their MtDNA within 24 h of hyperglycaemia. The increased MtDNA content in DCs and HMCs was not functional as transcription was unaltered/down-regulated, and MtDNA damage was present. MtDNA was increased in DC compared to HC, conversely, patients with DN had lower MtDNA than DC. Hyperglycaemic HMCs had fragmented mitochondria and TLR9 pathway activation, and in diabetic patients, mitophagy was reduced. Despite MtDNA content and integrity changing within 4 days, hyperglycaemic HMCs had a normal bio-energetic profile until 8 days, after which mitochondrial metabolism was progressively impaired. Peripheral blood mononuclear cells (PBMCs from DN patients had reduced reserve capacity and maximal respiration, loss of metabolic flexibility and reduced Bioenergetic Health Index (BHI compared to DC. Our data show that MtDNA changes precede bioenergetic dysfunction and that patients with DN have impaired mitochondrial metabolism compared to DC, leading us to propose that systemic mitochondrial dysfunction initiated by glucose induced MtDNA damage may be involved in the development of DN. Longitudinal studies are needed to define a potential cause–effect relationship between changes in MtDNA and bioenergetics in DN.

  14. Alterations in mitochondrial number and function in Alzheimer's disease fibroblasts.

    Science.gov (United States)

    Gray, Nora E; Quinn, Joseph F

    2015-10-01

    Mitochondrial dysfunction is observed in brains of Alzheimer's Disease patients as well as many rodent model systems including those modeling mutations in preseinilin 1 (PSEN1). The aim of our study was to characterize mitochondrial function and number in fibroblasts from AD patients with PSEN1 mutations. We used biochemical assays, metabolic profiling and fluorescent labeling to assess mitochondrial number and function in fibroblasts from three AD patients compared to fibroblasts from three controls. The mutant AD fibroblasts had increased Aβ42 relative to controls along with reduction in ATP, basal and maximal mitochondrial respiration as well as impaired spare mitochondrial respiratory capacity. Fluorescent staining and expression of genes encoding electron transport chain enzymes showed diminished mitochondrial content in the AD fibroblasts. This study demonstrates that mitochondrial dysfunction is observable in AD fibroblasts and provides evidence that this model system could be useful as a tool to screen disease-modifying compounds. PMID:25862550

  15. Alcohol alters hepatic FoxO1, p53, and mitochondrial SIRT5 deacetylation function

    International Nuclear Information System (INIS)

    Chronic alcohol consumption affects the gene expression of a NAD-dependent deacetylase Sirtuis 1 (SIRT1) and the peroxisome proliferator-activated receptor-γ coactivator1α (PGC-1α). Our aim was to verify that it also alters the forkhead (FoxO1) and p53 transcription factor proteins, critical in the hepatic response to oxidative stress and regulated by SIRT1 through its deacetylating capacity. Accordingly, rats were pair-fed the Lieber-DeCarli alcohol-containing liquid diets for 28 days. Alcohol increased hepatic mRNA expression of FoxO1 (p = 0.003) and p53 (p = 0.001) while corresponding protein levels remained unchanged. However phospho-FoxO1 and phospho-Akt (protein kinase) were both decreased by alcohol consumption (p = 0.04 and p = 0.02, respectively) while hepatic p53 was found hyperacetylated (p = 0.017). Furthermore, mitochondrial SIRT5 was reduced (p = 0.0025), and PGC-1α hyperacetylated (p = 0.027), establishing their role in protein modification. Thus, alcohol consumption disrupts nuclear-mitochondrial interactions by post-translation protein modifications, which contribute to alteration of mitochondrial biogenesis through the newly discovered reduction of SIRT5

  16. Radiation-induced alterations in mitochondrial protein synthesis in rat liver

    International Nuclear Information System (INIS)

    The incorporation of 14C-labeled leucine into hepatic mitochondrial proteins in vivo is enhanced up to 48 hr following whole-body X irradiation. A similar increase in labeling is also observed with liver slices from irradiated rats, incubated in vitro, but not with isolated liver mitochondria. Evidence is presented to indicate that these divergent labeling data may be related to the dual origin of the mitochondrial proteins and differences in the radiation-induced effects on the synthesis of mitochondrial proteins of intra- and extra-mitochondrial origin. The increased labeling observed in vivo does not denote a stimulation of mitochondrial protein synthesis but merely reflects a contraction of the free leucine pool of mitochondria. The possible significance of the radiation-induced alterations in the pattern of mitochondrial protein synthesis to the reported morphological alterations of this organelle is discussed

  17. Carbon tetrachloride-mediated lipid peroxidation induces early mitochondrial alterations in mouse liver.

    Science.gov (United States)

    Knockaert, Laetitia; Berson, Alain; Ribault, Catherine; Prost, Pierre-Emmanuel; Fautrel, Alain; Pajaud, Julie; Lepage, Sylvie; Lucas-Clerc, Catherine; Bégué, Jean-Marc; Fromenty, Bernard; Robin, Marie-Anne

    2012-03-01

    Although carbon tetrachloride (CCl(4))-induced acute and chronic hepatotoxicity have been extensively studied, little is known about the very early in vivo effects of this organic solvent on oxidative stress and mitochondrial function. In this study, mice were treated with CCl(4) (1.5 ml/kg ie 2.38 g/kg) and parameters related to liver damage, lipid peroxidation, stress/defense and mitochondria were studied 3 h later. Some CCl(4)-intoxicated mice were also pretreated with the cytochrome P450 2E1 inhibitor diethyldithiocarbamate or the antioxidants Trolox C and dehydroepiandrosterone. CCl(4) induced a moderate elevation of aminotransferases, swelling of centrilobular hepatocytes, lipid peroxidation, reduction of cytochrome P4502E1 mRNA levels and a massive increase in mRNA expression of heme oxygenase-1 and heat shock protein 70. Moreover, CCl(4) intoxication induced a severe decrease of mitochondrial respiratory chain complex IV activity, mitochondrial DNA depletion and damage as well as ultrastructural alterations. Whereas DDTC totally or partially prevented all these hepatic toxic events, both antioxidants protected only against liver lipid peroxidation and mitochondrial damage. Taken together, our results suggest that lipid peroxidation is primarily implicated in CCl(4)-induced early mitochondrial injury. However, lipid peroxidation-independent mechanisms seem to be involved in CCl(4)-induced early hepatocyte swelling and changes in expression of stress/defense-related genes. Antioxidant therapy may not be an efficient strategy to block early liver damage after CCl(4) intoxication. PMID:22157718

  18. Exercise mitigates mitochondrial permeability transition pore and quality control mechanisms alterations in nonalcoholic steatohepatitis.

    Science.gov (United States)

    Gonçalves, Inês O; Passos, Emanuel; Diogo, Cátia V; Rocha-Rodrigues, Sílvia; Santos-Alves, Estela; Oliveira, Paulo J; Ascensão, António; Magalhães, José

    2016-03-01

    Mitochondrial quality control and apoptosis have been described as key components in the pathogenesis of nonalcoholic steatohepatitis (NASH); exercise is recognized as a nonpharmacological strategy to counteract NASH-associated consequences. We aimed to analyze the effect of voluntary physical activity (VPA) and endurance training (ET) against NASH-induced mitochondrial permeability transition pore (mPTP) opening and mitochondrial and cellular quality control deleterious alterations. Forty-eight male Sprague-Dawley rats were divided into standard-diet sedentary (SS, n = 16), standard-diet VPA (n = 8), high-fat diet sedentary (HS, n = 16), and high-fat diet VPA (n = 8). After 9 weeks of diet treatment, half of the SS and HS groups were engaged in an ET program for 8 weeks, 5 days/week, 1 h/day. Liver mPTP susceptibility through osmotic swelling, mPTP-related proteins (cyclophilin D, Sirtuin3, Cofilin-1), markers of mitochondrial biogenesis ((mitochondrial transcription factor A (Tfam) and peroxisome proliferator-activated receptor gamma co-activator protein (PGC-1α)), dynamics (Mitofusin 1 (Mfn1), Mitofusin 2 (Mfn2), Dynamin related protein 1, and Optic atrophy 1)), auto/mitophagy (Beclin-1, microtubule-associated protein 1 light chain 3, p62, PINK1, and Parkin), and apoptotic signaling (Bax, Bcl-2) and caspases-like activities were assessed. HS animals showed an increased susceptibility to mPTP, compromised expression of Tfam, Mfn1, PINK1, and Parkin and an increase in Bax content (HS vs. SS). ET and VPA improved biogenesis-related proteins (PGC-1α) and autophagy signaling (Beclin-1 and Beclin-1/Bcl-2 ratio) and decreased apoptotic signaling (caspases 8 activity, Bax content, and Bax/Bcl-2 ratio). However, only ET decreased mPTP susceptibility and positively modulated Bcl-2, Tfam, Mfn1, Mfn2, PINK1, and Parkin content. In conclusion, exercise reduces the increased susceptibility to mPTP induced by NASH and promotes the increase of auto/mitophagy and mitochondrial

  19. Detection of mitochondrial deoxyribonucleic acid alterations in urine from urothelial cell carcinoma patients.

    NARCIS (Netherlands)

    Dasgupta, S.; Shao, C.; Keane, T.E.; Duberow, D.P.; Mathies, R.A.; Fisher, P.B.; Kiemeney, L.A.L.M.; Sidransky, D.

    2012-01-01

    Our study aims at understanding the timing and nature of mitochondrial deoxyribonucleic acid (mtDNA) alterations in urothelial cell carcinoma (UCC) and their detection in urine sediments. The entire 16.5 kb mitochondrial genome was sequenced in matched normal lymphocytes, tumor and urine sediments f

  20. Specific deletion of AMP-activated protein kinase (α1AMPK in murine oocytes alters junctional protein expression and mitochondrial physiology.

    Directory of Open Access Journals (Sweden)

    Michael J Bertoldo

    Full Text Available Oogenesis and folliculogenesis are dynamic processes that are regulated by endocrine, paracrine and autocrine signals. These signals are exchanged between the oocyte and the somatic cells of the follicle. Here we analyzed the role of AMP-activated protein kinase (AMPK, an important regulator of cellular energy homeostasis, by using transgenic mice deficient in α1AMPK specifically in the oocyte. We found a decrease of 27% in litter size was observed in ZP3-α1AMPK-/- (ZP3-KO female mice. Following in vitro fertilization, where conditions are stressful for the oocyte and embryo, ZP3-KO oocytes were 68% less likely to pass the 2-cell stage. In vivo and in cumulus-oocyte complexes, several proteins involved in junctional communication, such as connexin37 and N-cadherin were down-regulated in the absence of α1AMPK. While the two signalling pathways (PKA and MAPK involved in the junctional communication between the cumulus/granulosa cells and the oocyte were stimulated in control oocytes, ZP3-KO oocytes exhibited only low phosphorylation of MAPK or CREB proteins. In addition, MII oocytes deficient in α1AMPK had a 3-fold lower ATP concentration, an increase in abnormal mitochondria, and a decrease in cytochrome C and PGC1α levels, suggesting perturbed energy production by mitochondria. The absence of α1AMPK also induced a reduction in histone deacetylase activity, which was associated with an increase in histone H3 acetylation (K9/K14 residues. Together, the results of the present study suggest that absence of AMPK, modifies oocyte quality through energy processes and oocyte/somatic cell communication. The limited effect observed in vivo could be partly due to a favourable follicle microenvironment where nutrients, growth factors, and adequate cell interaction were present. Whereas in a challenging environment such as that of in vitro culture following IVF, the phenotype is revealed.

  1. A Hypertension-Associated tRNAAla Mutation Alters tRNA Metabolism and Mitochondrial Function

    Science.gov (United States)

    Jiang, Pingping; Wang, Meng; Xue, Ling; Xiao, Yun; Yu, Jialing; Wang, Hui; Yao, Juan; Liu, Hao; Peng, Yanyan; Liu, Hanqing; Li, Haiying; Chen, Ye

    2016-01-01

    In this report, we investigated the pathophysiology of a novel hypertension-associated mitochondrial tRNAAla 5655A → G (m.5655A → G) mutation. The destabilization of a highly conserved base pairing (A1-U72) at the aminoacyl acceptor stem by an m.5655A → G mutation altered the tRNAAla function. An in vitro processing analysis showed that the m.5655A → G mutation reduced the efficiency of tRNAAla precursor 5′ end cleavage catalyzed by RNase P. By using cybrids constructed by transferring mitochondria from lymphoblastoid cell lines derived from a Chinese family into mitochondrial DNA (mtDNA)-less (ρo) cells, we showed a 41% reduction in the steady-state level of tRNAAla in mutant cybrids. The mutation caused an improperly aminoacylated tRNAAla, as suggested by aberrantly aminoacylated tRNAAla and slower electrophoretic mobility of mutated tRNA. A failure in tRNAAla metabolism contributed to variable reductions in six mtDNA-encoded polypeptides in mutant cells, ranging from 21% to 37.5%, with an average of a 29.1% reduction, compared to levels of the controls. The impaired translation caused reduced activities of mitochondrial respiration chains. Furthermore, marked decreases in the levels of mitochondrial ATP and membrane potential were observed in mutant cells. These caused increases in the production of reactive oxygen species in the mutant cybrids. The data provide evidence for the association of the tRNAAla 5655A → G mutation with hypertension. PMID:27161322

  2. The biarylpyrazole compound AM251 alters mitochondrial physiology via proteolytic degradation of ERRα.

    Science.gov (United States)

    Krzysik-Walker, Susan M; González-Mariscal, Isabel; Scheibye-Knudsen, Morten; Indig, Fred E; Bernier, Michel

    2013-01-01

    The orphan nuclear receptor estrogen-related receptor alpha (ERRα) directs the transcription of nuclear genes involved in energy homeostasis control and the regulation of mitochondrial mass and function. A crucial role for controlling ERRα-mediated target gene expression has been ascribed to the biarylpyrazole compound 1-(2,4-dichlorophenyl)-5-(4-iodophenyl)-4-methyl-N-1-piperidinyl-1H-pyrazole-3-carboxamide (AM251) through direct binding to and destabilization of ERRα protein. Here, we provide evidence that structurally related AM251 analogs also have negative impacts on ERRα protein levels in a cell-type-dependent manner while having no deleterious actions on ERRγ. We show that these off-target cellular effects of AM251 are mediated by proteasomal degradation of nuclear ERRα. Cell treatment with the nuclear export inhibitor leptomycin B did not prevent AM251-induced destabilization of ERRα protein, whereas proteasome inhibition with MG132 stabilized and maintained its DNA-binding function, indicative of ERRα being a target of nuclear proteasomal complexes. NativePAGE analysis revealed that ERRα formed a ∼220-kDa multiprotein nuclear complex that was devoid of ERRγ and the coregulator peroxisome proliferator-activated receptor γ coactivator-1. AM251 induced SUMO-2,3 incorporation in ERRα in conjunction with increased protein kinase C activity, whose activation by phorbol ester also promoted ERRα protein loss. Down-regulation of ERRα by AM251 or small interfering RNA led to increased mitochondria biogenesis while negatively impacting mitochondrial membrane potential. These results reveal a novel molecular mechanism by which AM251 and related compounds alter mitochondrial physiology through destabilization of ERRα. PMID:23066093

  3. Mechanisms of Disease: Is Mitochondrial Function Altered in Heart Failure?

    OpenAIRE

    Hamilton, Dale J.

    2013-01-01

    The human heart sustains an exceptional energy transfer rate, consuming more energy per gram weight than any other organ system. The healthy heart can rapidly adapt to changes in demand, while the failing heart cannot. Cardiac energy flux systems falter in the failing heart. The purpose of this review is to characterize the fundamental role of mitochondria in this energy transfer system and describe our local research on mitochondrial respiratory capacity in failing human hearts.

  4. Mitochondrial gene polymorphisms alter hepatic cellular energy metabolism and aggravate diet-induced non-alcoholic steatohepatitis

    Directory of Open Access Journals (Sweden)

    Torsten Schröder

    2016-04-01

    Conclusions: We observed distinct metabolic alterations in mice with a mitochondrial polymorphism associated hepatic mitochondrial dysfunction. However, a second hit, such as dietary stress, was required to cause hepatic steatosis and inflammation. This study suggests a causative role of hepatic mitochondrial dysfunction in the development of experimental NASH.

  5. Altered mitochondrial function and oxidative stress in leukocytes of anorexia nervosa patients.

    Directory of Open Access Journals (Sweden)

    Victor M Victor

    Full Text Available CONTEXT: Anorexia nervosa is a common illness among adolescents and is characterised by oxidative stress. OBJECTIVE: The effects of anorexia on mitochondrial function and redox state in leukocytes from anorexic subjects were evaluated. DESIGN AND SETTING: A multi-centre, cross-sectional case-control study was performed. PATIENTS: Our study population consisted of 20 anorexic patients and 20 age-matched controls, all of which were Caucasian women. MAIN OUTCOME MEASURES: Anthropometric and metabolic parameters were evaluated in the study population. To assess whether anorexia nervosa affects mitochondrial function and redox state in leukocytes of anorexic patients, we measured mitochondrial oxygen consumption, membrane potential, reactive oxygen species production, glutathione levels, mitochondrial mass, and complex I and III activity in polymorphonuclear cells. RESULTS: Mitochondrial function was impaired in the leukocytes of the anorexic patients. This was evident in a decrease in mitochondrial O2 consumption (P<0.05, mitochondrial membrane potential (P<0.01 and GSH levels (P<0.05, and an increase in ROS production (P<0.05 with respect to control subjects. Furthermore, a reduction of mitochondrial mass was detected in leukocytes of the anorexic patients (P<0.05, while the activity of mitochondrial complex I (P<0.001, but not that of complex III, was found to be inhibited in the same population. CONCLUSIONS: Oxidative stress is produced in the leukocytes of anorexic patients and is closely related to mitochondrial dysfunction. Our results lead us to propose that the oxidative stress that occurs in anorexia takes place at mitochondrial complex I. Future research concerning mitochondrial dysfunction and oxidative stress should aim to determine the physiological mechanism involved in this effect and the physiological impact of anorexia.

  6. Misfolded SOD1 associated with motor neuron mitochondria alters mitochondrial shape and distribution prior to clinical onset.

    Directory of Open Access Journals (Sweden)

    Christine Vande Velde

    Full Text Available Mutations in superoxide dismutase (SOD1 are causative for inherited amyotrophic lateral sclerosis. A proportion of SOD1 mutant protein is misfolded onto the cytoplasmic face of mitochondria in one or more spinal cord cell types. By construction of mice in which mitochondrially targeted enhanced green fluorescent protein is selectively expressed in motor neurons, we demonstrate that axonal mitochondria of motor neurons are primary in vivo targets for misfolded SOD1. Mutant SOD1 alters axonal mitochondrial morphology and distribution, with dismutase active SOD1 causing mitochondrial clustering at the proximal side of Schmidt-Lanterman incisures within motor axons and dismutase inactive SOD1 producing aberrantly elongated axonal mitochondria beginning pre-symptomatically and increasing in severity as disease progresses. Somal mitochondria are altered by mutant SOD1, with loss of the characteristic cylindrical, networked morphology and its replacement by a less elongated, more spherical shape. These data indicate that mutant SOD1 binding to mitochondria disrupts normal mitochondrial distribution and size homeostasis as early pathogenic features of SOD1 mutant-mediated ALS.

  7. Alterations in mitochondrial respiratory functions, redox metabolism and apoptosis by oxidant 4-hydroxynonenal and antioxidants curcumin and melatonin in PC12 cells

    International Nuclear Information System (INIS)

    Cellular oxidative stress and alterations in redox metabolisms have been implicated in the etiology and pathology of many diseases including cancer. Antioxidant treatments have been proven beneficial in controlling these diseases. We have recently shown that 4-hydroxynonenal (4-HNE), a by-product of lipid peroxidation, induces oxidative stress in PC12 cells by compromising the mitochondrial redox metabolism. In this study, we have further investigated the deleterious effects of 4-HNE on mitochondrial respiratory functions and apoptosis using the same cell line. In addition, we have also compared the effects of two antioxidants, curcumin and melatonin, used as chemopreventive agents, on mitochondrial redox metabolism and respiratory functions in these cells. 4-HNE treatment has been shown to cause a reduction in glutathione (GSH) pool, an increase in reactive oxygen species (ROS), protein carbonylation and apoptosis. A marked inhibition in the activities of the mitochondrial respiratory enzymes, cytochrome c oxidase and aconitase was observed after 4-HNE treatment. Increased nuclear translocation of NF-kB/p65 protein was also observed after 4-HNE treatment. Curcumin and melatonin treatments, on the other hand, maintained the mitochondrial redox and respiratory functions without a marked effect on ROS production and cell viability. These results suggest that 4-HNE-induced cytotoxicity may be associated, at least in part, with the altered mitochondrial redox and respiratory functions. The alterations in mitochondrial energy metabolism and redox functions may therefore be critical in determining the difference between cell death and survival

  8. Altered Gene Expression, Mitochondrial Damage and Oxidative Stress: Converging Routes in Motor Neuron Degeneration

    Directory of Open Access Journals (Sweden)

    Luisa Rossi

    2012-01-01

    Full Text Available Motor neuron diseases (MNDs are a rather heterogeneous group of diseases, with either sporadic or genetic origin or both, all characterized by the progressive degeneration of motor neurons. At the cellular level, MNDs share features such as protein misfolding and aggregation, mitochondrial damage and energy deficit, and excitotoxicity and calcium mishandling. This is particularly well demonstrated in ALS, where both sporadic and familial forms share the same symptoms and pathological phenotype, with a prominent role for mitochondrial damage and resulting oxidative stress. Based on recent data, however, altered control of gene expression seems to be a most relevant, and previously overlooked, player in MNDs. Here we discuss which may be the links that make pathways apparently as different as altered gene expression, mitochondrial damage, and oxidative stress converge to generate a similar motoneuron-toxic phenotype.

  9. Alterations of Mitochondrial Function and Insulin Sensitivity in Human Obesity and Diabetes Mellitus.

    Science.gov (United States)

    Koliaki, Chrysi; Roden, Michael

    2016-07-17

    Mitochondrial function refers to a broad spectrum of features such as resting mitochondrial activity, (sub)maximal oxidative phosphorylation capacity (OXPHOS), and mitochondrial dynamics, turnover, and plasticity. The interaction between mitochondria and insulin sensitivity is bidirectional and varies depending on tissue, experimental model, methodological approach, and features of mitochondrial function tested. In human skeletal muscle, mitochondrial abnormalities may be inherited (e.g., lower mitochondrial content) or acquired (e.g., impaired OXPHOS capacity and plasticity). Abnormalities ultimately lead to lower mitochondrial functionality due to or resulting in insulin resistance and type 2 diabetes mellitus. Similar mechanisms can also operate in adipose tissue and heart muscle. In contrast, mitochondrial oxidative capacity is transiently upregulated in the liver of obese insulin-resistant humans with or without fatty liver, giving rise to oxidative stress and declines in advanced fatty liver disease. These data suggest a highly tissue-specific interaction between insulin sensitivity and oxidative metabolism during the course of metabolic diseases in humans. PMID:27146012

  10. Decidual cell polyploidization necessitates mitochondrial activity.

    Directory of Open Access Journals (Sweden)

    Xinghong Ma

    Full Text Available Cellular polyploidy has been widely reported in nature, yet its developmental mechanism and function remain poorly understood. In the present study, to better define the aspects of decidual cell polyploidy, we isolated pure polyploid and non-polyploid decidual cell populations from the in vivo decidual bed. Three independent RNA pools prepared for each population were then subjected to the Affymetrix gene chip analysis for the whole mouse genome transcripts. Our data revealed up-regulation of 1015 genes and down-regulation of 1207 genes in the polyploid populations, as compared to the non-polyploid group. Comparative RT-PCR and in situ hybridization results indeed confirmed differential expressional regulation of several genes between the two populations. Based on functional enrichment analyses, up-regulated polyploidy genes appeared to implicate several functions, which primarily include cell/nuclear division, ATP binding, metabolic process, and mitochondrial activity, whereas that of down-regulated genes primarily included apoptosis and immune processes. Further analyses of genes that are related to mitochondria and bi-nucleation showed differential and regional expression within the decidual bed, consistent with the pattern of polyploidy. Consistently, studies revealed a marked induction of mitochondrial mass and ATP production in polyploid cells. The inhibition of mitochondrial activity by various pharmacological inhibitors, as well as by gene-specific targeting using siRNA-mediated technology showed a dramatic attenuation of polyploidy and bi-nucleation development during in vitro stromal cell decidualization, suggesting mitochondria play a major role in positive regulation of decidual cell polyploidization. Collectively, analyses of unique polyploidy markers and molecular signaling networks may be useful to further characterize functional aspects of decidual cell polyploidy at the site of implantation.

  11. Implications of altered glutathione metabolism in aspirin-induced oxidative stress and mitochondrial dysfunction in HepG2 cells.

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    Haider Raza

    Full Text Available We have previously reported that acetylsalicylic acid (aspirin, ASA induces cell cycle arrest, oxidative stress and mitochondrial dysfunction in HepG2 cells. In the present study, we have further elucidated that altered glutathione (GSH-redox metabolism in HepG2 cells play a critical role in ASA-induced cytotoxicity. Using selected doses and time point for ASA toxicity, we have demonstrated that when GSH synthesis is inhibited in HepG2 cells by buthionine sulfoximine (BSO, prior to ASA treatment, cytotoxicity of the drug is augmented. On the other hand, when GSH-depleted cells were treated with N-acetyl cysteine (NAC, cytotoxicity/apoptosis caused by ASA was attenuated with a significant recovery in oxidative stress, GSH homeostasis, DNA fragmentation and some of the mitochondrial functions. NAC treatment, however, had no significant effects on the drug-induced inhibition of mitochondrial aconitase activity and ATP synthesis in GSH-depleted cells. Our results have confirmed that aspirin increases apoptosis by increased reactive oxygen species production, loss of mitochondrial membrane potential and inhibition of mitochondrial respiratory functions. These effects were further amplified when GSH-depleted cells were treated with ASA. We have also shown that some of the effects of aspirin might be associated with reduced GSH homeostasis, as treatment of cells with NAC attenuated the effects of BSO and aspirin. Our results strongly suggest that GSH dependent redox homeostasis in HepG2 cells is critical in preserving mitochondrial functions and preventing oxidative stress associated complications caused by aspirin treatment.

  12. Mitochondrial DNA alterations of peripheral lymphocytes in acute lymphoblastic leukemia patients undergoing total body irradiation therapy

    OpenAIRE

    2011-01-01

    Background Mitochondrial DNA (mtDNA) alterations, including mtDNA copy number and mtDNA 4977 bp common deletion (CD), are key indicators of irradiation-induced damage. The relationship between total body irradiation (TBI) treatment and mtDNA alterations in vivo, however, has not been postulated yet. The aim of this study is to analyze mtDNA alterations in irradiated human peripheral lymphocytes from acute lymphoblastic leukemia (ALL) patients as well as to take them as predictors for radiatio...

  13. Impaired enzymatic defensive activity, mitochondrial dysfunction and proteasome activation are involved in RTT cell oxidative damage.

    Science.gov (United States)

    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. PMID:26189585

  14. Breast Cancer Metabolism and Mitochondrial Activity: The Possibility of Chemoprevention with Metformin

    Directory of Open Access Journals (Sweden)

    Massimiliano Cazzaniga

    2015-01-01

    Full Text Available Metabolic reprogramming refers to the ability of cancer cells to alter their metabolism in order to support the increased energy request due to continuous growth, rapid proliferation, and other characteristics typical of neoplastic cells. It has long been believed that the increase of metabolic request was independent of the mitochondrial action but recently we know that mitochondrial activity together with metabolism plays a pivotal role in the regulation of the energy needed for tumor cell growth and proliferation. For these reasons the mitochondria pathways could be a new target for therapeutic and chemopreventive intervention. Metformin in particular is actually considered a promising agent against mitochondrial activity thanks to its ability to inhibit the mitochondrial complex I.

  15. Breast Cancer Metabolism and Mitochondrial Activity: The Possibility of Chemoprevention with Metformin.

    Science.gov (United States)

    Cazzaniga, Massimiliano; Bonanni, Bernardo

    2015-01-01

    Metabolic reprogramming refers to the ability of cancer cells to alter their metabolism in order to support the increased energy request due to continuous growth, rapid proliferation, and other characteristics typical of neoplastic cells. It has long been believed that the increase of metabolic request was independent of the mitochondrial action but recently we know that mitochondrial activity together with metabolism plays a pivotal role in the regulation of the energy needed for tumor cell growth and proliferation. For these reasons the mitochondria pathways could be a new target for therapeutic and chemopreventive intervention. Metformin in particular is actually considered a promising agent against mitochondrial activity thanks to its ability to inhibit the mitochondrial complex I. PMID:26605341

  16. Loss of Drp1 function alters OPA1 processing and changes mitochondrial membrane organization

    International Nuclear Information System (INIS)

    RNAi mediated loss of Drp1 function changes mitochondrial morphology in cultured HeLa and HUVEC cells by shifting the balance of mitochondrial fission and fusion towards unopposed fusion. Over time, inhibition of Drp1 expression results in the formation of a highly branched mitochondrial network along with 'bulge'-like structures. These changes in mitochondrial morphology are accompanied by a reduction in levels of Mitofusin 1 (Mfn1) and 2 (Mfn2) and a modified proteolytic processing of OPA1 isoforms, resulting in the inhibition of cell proliferation. In addition, our data imply that bulge formation is driven by Mfn1 action along with particular proteolytic short-OPA1 (s-OPA1) variants: Loss of Mfn2 in the absence of Drp1 results in an increase of Mfn1 levels along with processed s-OPA1-isoforms, thereby enhancing continuous 'fusion' and bulge formation. Moreover, bulge formation might reflect s-OPA1 mitochondrial membrane remodeling activity, resulting in the compartmentalization of cytochrome c deposits. The proteins Yme1L and PHB2 appeared not associated with the observed enhanced OPA1 proteolysis upon RNAi of Drp1, suggesting the existence of other OPA1 processing controlling proteins. Taken together, Drp1 appears to affect the activity of the mitochondrial fusion machinery by unbalancing the protein levels of mitofusins and OPA1.

  17. Mitochondrial control region alterations and breast cancer risk: a study in South Indian population.

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    Nageswara Rao Tipirisetti

    Full Text Available BACKGROUND: Mitochondrial displacement loop (D-loop is the hot spot for mitochondrial DNA (mtDNA alterations which influence the generation of cellular reactive oxygen species (ROS. Association of D-loop alterations with breast cancer has been reported in few ethnic groups; however none of the reports were documented from Indian subcontinent. METHODOLOGY: We screened the entire mitochondrial D-loop region (1124 bp of breast cancer patients (n = 213 and controls (n = 207 of south Indian origin by PCR-sequencing analysis. Haplotype frequencies for significant loci, the standardized disequilibrium coefficient (D' for pair-wise linkage disequilibrium (LD were assessed by Haploview Software. PRINCIPAL FINDINGS: We identified 7 novel mutations and 170 reported polymorphisms in the D-loop region of patients and/or controls. Polymorphisms were predominantly located in hypervariable region I (60% than in II (30% of D-loop region. The frequencies of 310'C' insertion (P = 0.018, T16189C (P = 0.0019 variants and 310'C'ins/16189C (P = 0.00019 haplotype were significantly higher in cases than in controls. Furthermore, strong LD was observed between nucleotide position 310 and 16189 in controls (D' = 0.49 as compared to patients (D' = 0.14. CONCLUSIONS: Mitochondrial D-loop alterations may constitute inherent risk factors for breast cancer development. The analysis of genetic alterations in the D-loop region might help to identify patients at high risk for bad progression, thereby helping to refine therapeutic decisions in breast cancer.

  18. Role of mitochondrial dysfunction and altered autophagy in cardiovascular aging and disease: from mechanisms to therapeutics

    OpenAIRE

    Marzetti, Emanuele; Csiszar, Anna; Dutta, Debapriya; Balagopal, Gauthami; Calvani, Riccardo; Leeuwenburgh, Christiaan

    2013-01-01

    Advanced age is associated with a disproportionate prevalence of cardiovascular disease (CVD). Intrinsic alterations in the heart and the vasculature occurring over the life course render the cardiovascular system more vulnerable to various stressors in late life, ultimately favoring the development of CVD. Several lines of evidence indicate mitochondrial dysfunction as a major contributor to cardiovascular senescence. Besides being less bioenergetically efficient, damaged mitochondria also p...

  19. Metabolic Alterations Induced by Sucrose Intake and Alzheimer’s Disease Promote Similar Brain Mitochondrial Abnormalities

    OpenAIRE

    Carvalho, Cristina; Cardoso, Susana; Correia, Sónia C; Santos, Renato X.; Santos, Maria S.; Baldeiras, Inês; oliveira, catarina r.; Moreira, Paula I.

    2012-01-01

    Evidence shows that diabetes increases the risk of developing Alzheimer’s disease (AD). Many efforts have been done to elucidate the mechanisms linking diabetes and AD. To demonstrate that mitochondria may represent a functional link between both pathologies, we compared the effects of AD and sucrose-induced metabolic alterations on mouse brain mitochondrial bioenergetics and oxidative status. For this purpose, brain mitochondria were isolated from wild-type (WT), triple transgenic AD (3xTg-A...

  20. Mitochondrial Alterations in Peripheral Mononuclear Blood Cells from Alzheimer's Disease and Mild Cognitive Impairment Patients.

    Science.gov (United States)

    Delbarba, A; Abate, G; Prandelli, C; Marziano, M; Buizza, L; Arce Varas, N; Novelli, A; Cuetos, F; Martinez, C; Lanni, C; Memo, M; Uberti, D

    2016-01-01

    It is well recognized that mitochondrial dysfunction contributes to neurodegeneration occurring in Alzheimer's disease (AD). However, evidences of mitochondrial defects in AD peripheral cells are still inconclusive. Here, some mitochondrial-encoded and nuclear-encoded proteins, involved in maintaining the correct mitochondria machine, were investigated in terms of protein expression and enzymatic activity in peripheral blood mononuclear cells (PBMCs) isolated from AD and Mild Cognitive Impairment (MCI) patients and healthy subjects. In addition mitochondrial DNA copy number was measured by real time PCR. We found some differences and some similarities between AD and MCI patients when compared with healthy subjects. For example, cytochrome C and cytochrome B were decreased in AD, while MCI showed only a statistical reduction of cytochrome C. On the other hand, both AD and MCI blood cells exhibited highly nitrated MnSOD, index of a prooxidant environment inside the mitochondria. TFAM, a regulator of mitochondrial genome replication and transcription, was decreased in both AD and MCI patients' blood cells. Moreover also the mitochondrial DNA amount was reduced in PBMCs from both patient groups. In conclusion these data confirmed peripheral mitochondria impairment in AD and demonstrated that TFAM and mtDNA amount reduction could be two features of early events occurring in AD pathogenesis. PMID:26881032

  1. Compartment-dependent mitochondrial alterations in experimental ALS, the effects of mitophagy and mitochondriogenesis.

    Science.gov (United States)

    Natale, Gianfranco; Lenzi, Paola; Lazzeri, Gloria; Falleni, Alessandra; Biagioni, Francesca; Ryskalin, Larisa; Fornai, Francesco

    2015-01-01

    Amyotrophic lateral sclerosis (ALS) is characterized by massive loss of motor neurons. Data from ALS patients and experimental models indicate that mitochondria are severely damaged within dying or spared motor neurons. Nonetheless, recent data indicate that mitochondrial preservation, although preventing motor neuron loss, fails to prolong lifespan. On the other hand, the damage to motor axons plays a pivotal role in determining both lethality and disease course. Thus, in the present article each motor neuron compartment (cell body, central, and peripheral axons) of G93A SOD-1 mice was studied concerning mitochondrial alterations as well as other intracellular structures. We could confirm the occurrence of ALS-related mitochondrial damage encompassing total swelling, matrix dilution and cristae derangement along with non-pathological variations of mitochondrial size and number. However, these alterations occur to a different extent depending on motor neuron compartment. Lithium, a well-known autophagy inducer, prevents most pathological changes. However, the efficacy of lithium varies depending on which motor neuron compartment is considered. Remarkably, some effects of lithium are also evident in wild type mice. Lithium is effective also in vitro, both in cell lines and primary cell cultures from the ventral spinal cord. In these latter cells autophagy inhibition within motor neurons in vitro reproduced ALS pathology which was reversed by lithium. Muscle and glial cells were analyzed as well. Cell pathology was mostly severe within peripheral axons and muscles of ALS mice. Remarkably, when analyzing motor axons of ALS mice a subtotal clogging of axoplasm was described for the first time, which was modified under the effects of lithium. The effects induced by lithium depend on several mechanisms such as direct mitochondrial protection, induction of mitophagy and mitochondriogenesis. In this study, mitochondriogenesis induced by lithium was confirmed in situ by a

  2. Compartment-dependent mitochondrial alterations in experimental ALS, the effects of mitophagy and mitochondriogenesis

    Directory of Open Access Journals (Sweden)

    Alessandra Falleni

    2015-11-01

    Full Text Available Amyotrophic lateral sclerosis (ALS is characterized by massive loss of motor neurons. Data from ALS patients and experimental models indicate that mitochondria are severely damaged within dying or spared motor neurons. Nonetheless, recent data indicate that mitochondrial preservation, although preventing motor neuron loss, fails to prolong lifespan. On the other hand, the damage to motor axons plays a pivotal role in determining both lethality and disease course. Thus, in the present article each motor neuron compartment (cell body, central and peripheral axons of G93A SOD-1 mice was studied concerning mitochondrial alterations as well as other intracellular structures. We could confirm the occurrence of ALS-related mitochondrial damage encompassing total swelling, matrix dilution and cristae derangement along with non-pathological variations of mitochondrial size and number. However, these alterations occur to a different extent depending on motor neuron compartment. Lithium, a well known autophagy inducer, prevents most pathological changes. However, the efficacy of lithium varies depending on which motor neuron compartment is considered. Remarkably, some effects of lithium are also evident in wild type mice. Lithium is effective also in vitro, both in cell lines and primary cell cultures from the ventral spinal cord. In these latter cells autophagy inhibition within motor neurons in vitro reproduced ALS pathology which was reversed by lithium. Muscle and glial cells were analyzed as well. Cell pathology was mostly severe within peripheral axons and muscles of ALS mice. Remarkably, when analyzing motor axons of ALS mice a subtotal clogging of axoplasm was described for the first time, which was modified under the effects of lithium. The effects induced by lithium depend on several mechanisms such as direct mitochondrial protection, induction of mitophagy and mitochondriogenesis. In this study, mitochondriogenesis induced by lithium was

  3. Effect of Neem Oil on Sperm Mitochondrial Activity

    OpenAIRE

    Prashant Patil; Gaikwad RD; Sawane MV; Waghmare VS

    2010-01-01

    It is a known fact that neem oil has some effect on motility of sperm. Motility of sperm depends on mitochondrial activity present in mid-piece of sperm. In the present study, the mitochondrial activity of sperm was evaluated after treating semen with the different quantities of neem oil. The mitochondrial activity was also evaluated after subjecting the semen samples for different incubation periods keeping the quantity of semen as well as that of neem oil same. Tests were done on thirty nor...

  4. Gestational diabetes is characterized by reduced mitochondrial protein expression and altered calcium signaling proteins in skeletal muscle.

    Directory of Open Access Journals (Sweden)

    Kristen E Boyle

    Full Text Available The rising prevalence of gestational diabetes mellitus (GDM affects up to 18% of pregnant women with immediate and long-term metabolic consequences for both mother and infant. Abnormal glucose uptake and lipid oxidation are hallmark features of GDM prompting us to use an exploratory proteomics approach to investigate the cellular mechanisms underlying differences in skeletal muscle metabolism between obese pregnant women with GDM (OGDM and obese pregnant women with normal glucose tolerance (ONGT. Functional validation was performed in a second cohort of obese OGDM and ONGT pregnant women. Quantitative proteomic analysis in rectus abdominus skeletal muscle tissue collected at delivery revealed reduced protein content of mitochondrial complex I (C-I subunits (NDUFS3, NDUFV2 and altered content of proteins involved in calcium homeostasis/signaling (calcineurin A, α1-syntrophin, annexin A4 in OGDM (n = 6 vs. ONGT (n = 6. Follow-up analyses showed reduced enzymatic activity of mitochondrial complexes C-I, C-III, and C-IV (-60-75% in the OGDM (n = 8 compared with ONGT (n = 10 subjects, though no differences were observed for mitochondrial complex protein content. Upstream regulators of mitochondrial biogenesis and oxidative phosphorylation were not different between groups. However, AMPK phosphorylation was dramatically reduced by 75% in the OGDM women. These data suggest that GDM is associated with reduced skeletal muscle oxidative phosphorylation and disordered calcium homeostasis. These relationships deserve further attention as they may represent novel risk factors for development of GDM and may have implications on the effectiveness of physical activity interventions on both treatment strategies for GDM and for prevention of type 2 diabetes postpartum.

  5. Prolonged exposure to (R)-bicalutamide generates a LNCaP subclone with alteration of mitochondrial genome.

    Science.gov (United States)

    Pignatta, Sara; Arienti, Chiara; Zoli, Wainer; Di Donato, Marzia; Castoria, Gabriella; Gabucci, Elisa; Casadio, Valentina; Falconi, Mirella; De Giorgi, Ugo; Silvestrini, Rosella; Tesei, Anna

    2014-01-25

    Advanced prostate cancers, initially sensitive to androgen deprivation therapy, frequently progress to the castration-resistant prostate cancer phenotype (CRPC) through mechanisms not yet fully understood. In this study we investigated mitochondrial involvement in the establishment of refractoriness to hormone therapy. Two human prostate cancer cell lines were used, the parental LNCaP and the resistant LNCaP-Rbic, the latter generated after continuous exposure to 20 μM of (R)-bicalutamide, the active enantiomer of Casodex®. We observed a significant decrease in mtDNA content and a lower expression of 8 mitochondria-encoded gene transcripts involved in respiratory chain complexes in both cell lines. We also found that (R)-bicalutamide differentially modulated dynamin-related protein (Drp-1) expression in LNCaP and LNCaP-Rbic cells. These data seem to indicate that the androgen-independent phenotype in our experimental model was due, at least in part, to alterations in mitochondrial dynamics and to a breakdown in the Drp-1-mediated mitochondrial network. PMID:24397920

  6. Therapeutic Approaches in Mitochondrial Dysfunction, Proteolysis, and Structural Alterations of Diaphragm and Gastrocnemius in Rats With Chronic Heart Failure.

    Science.gov (United States)

    Barreiro, Esther; Puig-Vilanova, Ester; Marin-Corral, Judith; Chacón-Cabrera, Alba; Salazar-Degracia, Anna; Mateu, Xavier; Puente-Maestu, Luis; García-Arumí, Elena; Andreu, Antoni L; Molina, Luis

    2016-07-01

    Patients with chronic heart failure (CHF) experience exercise intolerance, fatigue and muscle wasting, which negatively influence their survival. We hypothesized that treatment with either the antioxidant N-acetyl cysteine (NAC) or the proteasome inhibitor bortezomib of rats with monocrotaline-induced CHF may restore inspiratory and limb muscle mass, function, and structure through several molecular mechanisms involved in protein breakdown and metabolism in the diaphragm and gastrocnemius. In these muscles of CHF-cachectic rats with and without treatment with NAC or bortezomib (N = 10/group) and non-cachectic controls, proteolysis (tyrosine release, proteasome activities, ubiquitin-proteasome markers), oxidative stress, inflammation, mitochondrial function, myosin, NF-κB transcriptional activity, muscle structural abnormalities, and fiber morphometry were analyzed together with muscle and cardiac functions. In diaphragm and gastrocnemius of CHF-cachectic rats, tyrosine release, proteasome activity, protein ubiquitination, atrogin-1, MURF-1, NF-κB activity, oxidative stress, inflammation, and structural abnormalities were increased, while muscle and cardiac functions, myosin content, slow- and fast-twitch fiber sizes, and mitochondrial activity were decreased. Concomitant treatment of CHF-cachectic rats with NAC or bortezomib improved protein catabolism, oxidative stress, inflammation, muscle fiber sizes, function and damage, superoxide dismutase and myosin levels, mitochondrial function (complex I, gastrocnemius), cardiac function and decreased NF-κB transcriptional activity in both muscles. Treatment of CHF-cachectic animals with NAC or bortezomib attenuated the functional (heart, muscles), biological, and structural alterations in muscles. Nonetheless, future studies conducted in actual clinical settings are warranted in order to assess the potential beneficial effects and safety concerns of these pharmacological agents on muscle mass loss and wasting in

  7. Mic60/mitofilin overexpression alters mitochondrial dynamics and attenuates vulnerability of dopaminergic cells to dopamine and rotenone.

    Science.gov (United States)

    Van Laar, Victor S; Berman, Sarah B; Hastings, Teresa G

    2016-07-01

    Mitochondrial dysfunction has been implicated in Parkinson's disease (PD) neuropathology. Mic60, also known as mitofilin, is a protein of the inner mitochondrial membrane and a key component of the mitochondrial contact site and cristae junction organizing system (MICOS). Mic60 is critical for maintaining mitochondrial membrane structure and function. We previously demonstrated that mitochondrial Mic60 protein is susceptible to both covalent modification and loss in abundance following exposure to dopamine quinone. In this study, we utilized neuronally-differentiated SH-SY5Y and PC12 dopaminergic cell lines to examine the effects of altered Mic60 levels on mitochondrial function and cellular vulnerability in response to PD-relevant stressors. Short hairpin RNA (shRNA)-mediated knockdown of endogenous Mic60 protein in neuronal SH-SY5Y cells significantly potentiated dopamine-induced cell death, which was rescued by co-expressing shRNA-insensitive Mic60. Conversely, in PC12 and SH-SY5Y cells, Mic60 overexpression significantly attenuated both dopamine- and rotenone-induced cell death as compared to controls. Mic60 overexpression in SH-SY5Y cells was also associated with increased mitochondrial respiration, and, following rotenone exposure, increased spare respiratory capacity. Mic60 knockdown cells exhibited suppressed respiration and, following rotenone treatment, decreased spare respiratory capacity. Mic60 overexpression also affected mitochondrial fission/fusion dynamics. PC12 cells overexpressing Mic60 exhibited increased mitochondrial interconnectivity. Further, both PC12 cells and primary rat cortical neurons overexpressing Mic60 displayed suppressed mitochondrial fission and increased mitochondrial length in neurites. These results suggest that altering levels of Mic60 in dopaminergic neuronal cells significantly affects both mitochondrial homeostasis and cellular vulnerability to the PD-relevant stressors dopamine and rotenone, carrying implications for PD

  8. Mitochondrial physiology and reactive oxygen species production are altered by hypoxia acclimation in killifish (Fundulus heteroclitus).

    Science.gov (United States)

    Du, Sherry N N; Mahalingam, Sajeni; Borowiec, Brittney G; Scott, Graham R

    2016-04-15

    Many fish encounter hypoxia in their native environment, but the role of mitochondrial physiology in hypoxia acclimation and hypoxia tolerance is poorly understood. We investigated the effects of hypoxia acclimation on mitochondrial respiration, O2kinetics, emission of reactive oxygen species (ROS), and antioxidant capacity in the estuarine killifish ( ITALIC! Fundulus heteroclitus). Killifish were acclimated to normoxia, constant hypoxia (5 kPa O2) or intermittent diel cycles of nocturnal hypoxia (12 h:12 h normoxia:hypoxia) for 28-33 days and mitochondria were isolated from liver. Neither pattern of hypoxia acclimation affected the respiratory capacities for oxidative phosphorylation or electron transport, leak respiration, coupling control or phosphorylation efficiency. Hypoxia acclimation also had no effect on mitochondrial O2kinetics, but ITALIC! P50(the O2tension at which hypoxia inhibits respiration by 50%) was lower in the leak state than during maximal respiration, and killifish mitochondria endured anoxia-reoxygenation without any impact on mitochondrial respiration. However, both patterns of hypoxia acclimation reduced the rate of ROS emission from mitochondria when compared at a common O2tension. Hypoxia acclimation also increased the levels of protein carbonyls and the activities of superoxide dismutase and catalase in liver tissue (the latter only occurred in constant hypoxia). Our results suggest that hypoxia acclimation is associated with changes in mitochondrial physiology that decrease ROS production and may help improve hypoxia tolerance. PMID:26896545

  9. Mitochondrial Function in Physically Active Elders with Sarcopenia

    OpenAIRE

    Waters, DL; Mullins, PG; Qualls, CR; Raj, DR; Gasparovic, C; Baumgartner, RN

    2009-01-01

    Physical activity is reported to protect against sarcopenia and preserve mitochondrial function. Healthy normal lean (NL: n=15) and sarcopenic (SS: n=9) participants were recruited based on body composition (DXA, Lunar DPX™), age, and physical activity. Gastrocnemius mitochondrial function was assessed by 31P MRS using steady-state exercise in a 4 T Bruker Biospin. Total work (429.3 ± 160.2 vs 851.0 ± 211.7 J, p

  10. Role of Mitochondrial DNA Copy Number Alteration in Human Renal Cell Carcinoma

    Directory of Open Access Journals (Sweden)

    Chen-Sung Lin

    2016-05-01

    Full Text Available We investigated the role of mitochondrial DNA (mtDNA copy number alteration in human renal cell carcinoma (RCC. The mtDNA copy numbers of paired cancer and non-cancer parts from five resected RCC kidneys after radical nephrectomy were determined by quantitative polymerase chain reaction (Q-PCR. An RCC cell line, 786-O, was infected by lentiviral particles to knock down mitochondrial transcriptional factor A (TFAM. Null target (NT and TFAM-knockdown (TFAM-KD represented the control and knockdown 786-O clones, respectively. Protein or mRNA expression levels of TFAM; mtDNA-encoded NADH dehydrogenase subunit 1 (ND1, ND6 and cytochrome c oxidase subunit 2 (COX-2; nuclear DNA (nDNA-encoded succinate dehydrogenase subunit A (SDHA; v-akt murine thymoma viral oncogene homolog 1 gene (AKT-encoded AKT and v-myc myelocytomatosis viral oncogene homolog gene (c-MYC-encoded MYC; glycolytic enzymes including hexokinase II (HK-II, glucose 6-phosphate isomerase (GPI, phosphofructokinase (PFK, and lactate dehydrogenase subunit A (LDHA; and hypoxia-inducible factors the HIF-1α and HIF-2α, pyruvate dehydrogenase kinase 1 (PDK1, and pyruvate dehydrogenase E1 component α subunit (PDHA1 were analyzed by Western blot or Q-PCR. Bioenergetic parameters of cellular metabolism, basal mitochondrial oxygen consumption rate (mOCRB and basal extracellular acidification rate (ECARB, were measured by a Seahorse XFe-24 analyzer. Cell invasiveness was evaluated by a trans-well migration assay and vimentin expression. Doxorubicin was used as a chemotherapeutic agent. The results showed a decrease of mtDNA copy numbers in resected RCC tissues (p = 0.043. The TFAM-KD clone expressed lower mtDNA copy number (p = 0.034, lower mRNA levels of TFAM (p = 0.008, ND1 (p = 0.007, and ND6 (p = 0.017, and lower protein levels of TFAM and COX-2 than did the NT clone. By contrast, the protein levels of HIF-2α, HK-II, PFK, LDHA, AKT, MYC and vimentin; trans-well migration activity (p = 0

  11. Effect of Neem Oil on Sperm Mitochondrial Activity

    Directory of Open Access Journals (Sweden)

    Prashant Patil

    2010-04-01

    Full Text Available It is a known fact that neem oil has some effect on motility of sperm. Motility of sperm depends on mitochondrial activity present in mid-piece of sperm. In the present study, the mitochondrial activity of sperm was evaluated after treating semen with the different quantities of neem oil. The mitochondrial activity was also evaluated after subjecting the semen samples for different incubation periods keeping the quantity of semen as well as that of neem oil same. Tests were done on thirty normozoospermic semen samples with motile score more than 75%. It was found that as the quantity of neem oil increases, the mitochondrial activity decreases significantly (P < 0.001. Similar results were found, when same quantity of neem oil was treated with same quantity of semen, but incubating for different time durations. The mitochondrial activity decreases significantly (P < 0.001 from one minute to twenty minutes. So, it indicates that as the contact period between neem oil and semen increases the mitochondrial activity decreases significantly.

  12. Alterations in Lipid Levels of Mitochondrial Membranes Induced by Amyloid-ß: A Protective Role of Melatonin

    Directory of Open Access Journals (Sweden)

    Sergio A. Rosales-Corral

    2012-01-01

    Full Text Available Alzheimer pathogenesis involves mitochondrial dysfunction, which is closely related to amyloid-ß (Aß generation, abnormal tau phosphorylation, oxidative stress, and apoptosis. Alterations in membranal components, including cholesterol and fatty acids, their characteristics, disposition, and distribution along the membranes, have been studied as evidence of cell membrane alterations in AD brain. The majority of these studies have been focused on the cytoplasmic membrane; meanwhile the mitochondrial membranes have been less explored. In this work, we studied lipids and mitochondrial membranes in vivo, following intracerebral injection of fibrillar amyloid-ß (Aß. The purpose was to determine how Aß may be responsible for beginning of a vicious cycle where oxidative stress and alterations in cholesterol, lipids and fatty acids, feed back on each other to cause mitochondrial dysfunction. We observed changes in mitochondrial membrane lipids, and fatty acids, following intracerebral injection of fibrillar Aß in aged Wistar rats. Melatonin, a well-known antioxidant and neuroimmunomodulator indoleamine, reversed some of these alterations and protected mitochondrial membranes from obvious damage. Additionally, melatonin increased the levels of linolenic and n-3 eicosapentaenoic acid, in the same site where amyloid ß was injected, favoring an endogenous anti-inflammatory pathway.

  13. Magnesium regulates neural stem cell proliferation in the mouse hippocampus by altering mitochondrial function.

    Science.gov (United States)

    Jia, Shanshan; Mou, Chengzhi; Ma, Yihe; Han, Ruijie; Li, Xue

    2016-04-01

    In the adult brain, neural stem cells from the subgranular zone (SGZ) of the hippocampus and the subventricular zone (SVZ) of the cortex progress through the following five developmental stages: radial glia-like cells, neural progenitor cells, neuroblasts, immature neurons, and mature neurons. These developmental stages are linked to both neuronal microenvironments and energy metabolism. Neurogenesis is restricted and has been demonstrated to arise from tissue microenvironments. We determined that magnesium, a key nutrient in cellular energy metabolism, affects neural stem cell (NSC) proliferation in cells derived from the embryonic hippocampus by influencing mitochondrial function. Densities of proliferating cells and NSCs both showed their highest values at 0.8 mM [Mg(2+) ]o , whereas lower proliferation rates were observed at 0.4 and 1.4 mM [Mg(2+) ]o . The numbers and sizes of the neurospheres reached the maximum at 0.8 mM [Mg(2+) ]o and were weaker under both low (0.4 mM) and high (1.4 mM) concentrations of magnesium. In vitro experimental evidence demonstrates that extracellular magnesium regulates the number of cultured hippocampal NSCs, affecting both magnesium homeostasis and mitochondrial function. Our findings indicate that the effect of [Mg(2+) ]o on NSC proliferation may lie downstream of alterations in mitochondrial function because mitochondrial membrane potential was highest in the NSCs in the moderate [Mg(2+) ]o (0.8 mM) group and lower in both the low (0.4 mM) and high (1.4 mM) [Mg(2+) ]o groups. Overall, these findings demonstrate a new function for magnesium in the brain in the regulation of hippocampal neural stem cells: affecting their cellular energy metabolism. PMID:26634890

  14. Nuclear and mitochondrial DNA alterations in newborns with prenatal exposure to cigarette smoke.

    Science.gov (United States)

    Pirini, Francesca; Guida, Elisa; Lawson, Fahcina; Mancinelli, Andrea; Guerrero-Preston, Rafael

    2015-02-01

    Newborns exposed to maternal cigarette smoke (CS) in utero have an increased risk of developing chronic diseases, cancer, and acquiring decreased cognitive function in adulthood. Although the literature reports many deleterious effects associated with maternal cigarette smoking on the fetus, the molecular alterations and mechanisms of action are not yet clear. Smoking may act directly on nuclear DNA by inducing mutations or epigenetic modifications. Recent studies also indicate that smoking may act on mitochondrial DNA by inducing a change in the number of copies to make up for the damage caused by smoking on the respiratory chain and lack of energy. In addition, individual genetic susceptibility plays a significant role in determining the effects of smoking during development. Furthermore, prior exposure of paternal and maternal gametes to cigarette smoke may affect the health of the developing individual, not only the in utero exposure. This review examines the genetic and epigenetic alterations in nuclear and mitochondrial DNA associated with smoke exposure during the most sensitive periods of development (prior to conception, prenatal and early postnatal) and assesses how such changes may have consequences for both fetal growth and development. PMID:25648174

  15. Nuclear and Mitochondrial DNA Alterations in Newborns with Prenatal Exposure to Cigarette Smoke

    Directory of Open Access Journals (Sweden)

    Francesca Pirini

    2015-01-01

    Full Text Available Newborns exposed to maternal cigarette smoke (CS in utero have an increased risk of developing chronic diseases, cancer, and acquiring decreased cognitive function in adulthood. Although the literature reports many deleterious effects associated with maternal cigarette smoking on the fetus, the molecular alterations and mechanisms of action are not yet clear. Smoking may act directly on nuclear DNA by inducing mutations or epigenetic modifications. Recent studies also indicate that smoking may act on mitochondrial DNA by inducing a change in the number of copies to make up for the damage caused by smoking on the respiratory chain and lack of energy. In addition, individual genetic susceptibility plays a significant role in determining the effects of smoking during development. Furthermore, prior exposure of paternal and maternal gametes to cigarette smoke may affect the health of the developing individual, not only the in utero exposure. This review examines the genetic and epigenetic alterations in nuclear and mitochondrial DNA associated with smoke exposure during the most sensitive periods of development (prior to conception, prenatal and early postnatal and assesses how such changes may have consequences for both fetal growth and development.

  16. Dietary ω-3 Fatty Acids Alter Cardiac Mitochondrial Phospholipid Composition and Delay Ca2+-Induced Permeability Transition

    OpenAIRE

    O’Shea, Karen M.; Khairallah, Ramzi J.; Sparagna, Genevieve C.; Xu, Wenhong; Hecker, Peter A; Robillard-Frayne, Isabelle; Des Rosiers, Christine; Kristian, Tibor; Robert C. Murphy; Fiskum, Gary; Stanley, William C.

    2009-01-01

    Consumption of ω-3 fatty acids from fish oil, specifically eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), decreases risk for heart failure and attenuates pathologic cardiac remodeling in response to pressure overload. Dietary supplementation with EPA+DHA may also impact cardiac mitochondrial function and energetics through alteration of membrane phospholipids. We assessed the role of EPA+DHA supplementation on left ventricular (LV) function, cardiac mitochondrial membrane phospho...

  17. Mitochondrial Alterations in Peripheral Mononuclear Blood Cells from Alzheimer’s Disease and Mild Cognitive Impairment Patients

    OpenAIRE

    Delbarba, A.; Abate, G; Prandelli, C; Marziano, M.; Buizza, L.; Arce Varas, N.; Novelli, A.; Cuetos, F.; Martinez, C.; C. Lanni; Memo, M.; Uberti, D.

    2016-01-01

    It is well recognized that mitochondrial dysfunction contributes to neurodegeneration occurring in Alzheimer's disease (AD). However, evidences of mitochondrial defects in AD peripheral cells are still inconclusive. Here, some mitochondrial-encoded and nuclear-encoded proteins, involved in maintaining the correct mitochondria machine, were investigated in terms of protein expression and enzymatic activity in peripheral blood mononuclear cells (PBMCs) isolated from AD and Mild Cognitive Impair...

  18. Sequence alterations of the whole mitochondrial genome in primary and recurrent ovarian carcinomas

    Institute of Scientific and Technical Information of China (English)

    Shi Hong-hui; Song Tian; Pan Ling-ya

    2007-01-01

    Objective: To investigate mitochondrial DNA (mtDNA) alterations in primary and recurrent ovarian carcinomas to illuminate the impact of chemotherapy on mtDNA.Methods.Complete mtDNA genomes of tumor tissue from 7 pimary ovarian carcinoma patients without treatment and 9 recurrent ones with prior chemotherapies were sequenced as well as their matched normal tissue.MtDNA alterations, including somatic mutations and new polymorphisms and consequent amino-acid alterations were compared between the two groups.Results, A large number of mtDNA new polymorphisms (69) and somatic mutations (17) were found in 16 ovarian carcinoma samples.Chemotherapy might not lead to more, heteroplasmic mutations and consequent aminoacid alterations (P>0.05) in the recurrent ovarian carcinoma patients than in the untreated ones.Conclusions: MtDNA damage was not so certainly made by chemotherapies and some of the mtDNA defects might be part of the disease process rather than a consequence of treatment.

  19. Decreased heat shock protein 27 expression and altered autophagy in human cells harboring A8344G mitochondrial DNA mutation.

    Science.gov (United States)

    Chen, Chin-Yi; Chen, Hsueh-Fu; Gi, Siao-Jhen; Chi, Tang-Hao; Cheng, Che-Kun; Hsu, Chi-Fu; Ma, Yi-Shing; Wei, Yau-Huei; Liu, Chin-Shan; Hsieh, Mingli

    2011-09-01

    Mitochondrial DNA (mtDNA) mutations are responsible for human neuromuscular diseases caused by mitochondrial dysfunction. Myoclonus epilepsy associated with ragged-red fibers (MERRF) is a maternally inherited mitochondrial encephalomyopathy with various syndromes involving both muscular and nervous systems. The most common mutation in MERRF syndrome, A8344G mutation in mtDNA, has been associated with severe defects in protein synthesis. This defect impairs assembly of complexes in electron transport chain and results in decreased respiratory function of mitochondria. In this study, we showed a significant decrease of the heat shock protein 27 (Hsp27) in lymphoblastoid cells derived from a MERRF patient and in cybrid cells harboring MERRF A8344G mutation. However, normal cytoplasmic distributions of Hsp27 and normal heat shock responses were observed in both wild type and mutant cybrids. Furthermore, overexpression of wild type Hsp27 in mutant MERRF cybrids significantly decreased cell death under staurosporine (STS) treatment, suggesting a protective function of Hsp27 in cells harboring the A8344G mutation of mtDNA. Meanwhile, reverse transcriptase PCR showed no difference in the mRNA level between normal and mutant cybrids, indicating that alterations may occur at the protein level. Evidenced by the decreased levels of Hsp27 upon treatment with proteasome inhibitor, starvation and rapamycin and the accumulation of Hsp27 upon lysosomal inhibitor treatment; Hsp27 may be degraded by the autophagic pathway. In addition, the increased formation of LC3-II and autophagosomes was found in MERRF cybrids under the basal condition, indicating a constitutively-activated autophagic pathway. It may explain, at least partially, the faster turnover of Hsp27 in MERRF cybrids. This study provides information for us to understand that Hsp27 is degraded through the autophagic pathway and that Hsp27 may have a protective role in MERRF cells. Regulating Hsp27 and the autophagic pathway

  20. Alterations of motor performance and brain cortex mitochondrial function during ethanol hangover.

    Science.gov (United States)

    Bustamante, Juanita; Karadayian, Analia G; Lores-Arnaiz, Silvia; Cutrera, Rodolfo A

    2012-08-01

    Ethanol has been known to affect various behavioral parameters in experimental animals, even several hours after ethanol (EtOH) is absent from blood circulation, in the period known as hangover. The aim of this study was to assess the effects of acute ethanol hangover on motor performance in association with the brain cortex energetic metabolism. Evaluation of motor performance and brain cortex mitochondrial function during alcohol hangover was performed in mice 6 hours after a high ethanol dose (hangover onset). Animals were injected i.p. either with saline (control group) or with ethanol (3.8 g/kg BW) (hangover group). Ethanol hangover group showed a bad motor performance compared with control animals (p hangover animals showed a 34% decrease in the respiratory control rate as compared with the control group. Mitochondrial complex activities were decreased being the complex I-III the less affected by the hangover condition; complex II-III was markedly decreased by ethanol hangover showing 50% less activity than controls. Complex IV was 42% decreased as compared with control animals. Hydrogen peroxide production was 51% increased in brain cortex mitochondria from the hangover group, as compared with the control animals. Quantification of the mitochondrial transmembrane potential indicated that ethanol injected animals presented 17% less ability to maintain the polarized condition as compared with controls. These results indicate that a clear decrease in proton motive force occurs in brain cortex mitochondria during hangover conditions. We can conclude that a decreased motor performance observed in the hangover group of animals could be associated with brain cortex mitochondrial dysfunction and the resulting impairment of its energetic metabolism. PMID:22608205

  1. Treatment of human astrocytoma U87 cells with silicon dioxide nanoparticles lowers their survival and alters their expression of mitochondrial and cell signaling proteins

    Directory of Open Access Journals (Sweden)

    James CK Lai

    2010-09-01

    in a dose-related manner. The activities of citrate synthase and malate dehydrogenase in treated U87 cells were increased, possibly due to an energetic compensation in surviving cells. However, the expression of mitochondrial DNA-encoded cytochrome C oxidase subunit II and NADH dehydrogenase subunit 6 and the cell signaling protein ERK and phosphorylated ERK were altered in the treated U87 cells, suggesting that silicon dioxide nanoparticles induced disruption of mitochondrial DNA-encoded protein expression, leading to decreased mitochondrial energy production and decreased cell survival/proliferation signaling. Thus, our results strongly suggest that the cytotoxicity of silicon dioxide nanoparticles in human neural cells implicates altered mitochondrial function and cell survival/proliferation signaling.Keywords: cytotoxicity, silicon dioxide nanoparticles, mitochondrial enzyme, extracellular signaling regulated kinase, cell signaling, neural cells

  2. Mitochondrial DNA alterations of peripheral lymphocytes in acute lymphoblastic leukemia patients undergoing total body irradiation therapy

    International Nuclear Information System (INIS)

    Mitochondrial DNA (mtDNA) alterations, including mtDNA copy number and mtDNA 4977 bp common deletion (CD), are key indicators of irradiation-induced damage. The relationship between total body irradiation (TBI) treatment and mtDNA alterations in vivo, however, has not been postulated yet. The aim of this study is to analyze mtDNA alterations in irradiated human peripheral lymphocytes from acute lymphoblastic leukemia (ALL) patients as well as to take them as predictors for radiation toxicity. Peripheral blood lymphocytes were isolated from 26 ALL patients 24 hours after TBI preconditioning (4.5 and 9 Gy, respectively). Extracted DNA was analyzed by real-time PCR method. Average 2.31 times mtDNA and 0.53 fold CD levels were observed after 4.5 Gy exposure compared to their basal levels. 9 Gy TBI produced a greater response of both mtDNA and CD levels than 4.5 Gy. Significant inverse correlation was found between mtDNA content and CD level at 4.5 and 9 Gy (P = 0.037 and 0.048). Moreover, mtDNA content of lymphocytes without irradiation was found to be correlated to age. mtDNA and CD content may be considered as predictive factors to radiation toxicity

  3. Mitochondrial DNA alterations of peripheral lymphocytes in acute lymphoblastic leukemia patients undergoing total body irradiation therapy

    Directory of Open Access Journals (Sweden)

    Ji Fuyun

    2011-10-01

    Full Text Available Abstract Background Mitochondrial DNA (mtDNA alterations, including mtDNA copy number and mtDNA 4977 bp common deletion (CD, are key indicators of irradiation-induced damage. The relationship between total body irradiation (TBI treatment and mtDNA alterations in vivo, however, has not been postulated yet. The aim of this study is to analyze mtDNA alterations in irradiated human peripheral lymphocytes from acute lymphoblastic leukemia (ALL patients as well as to take them as predictors for radiation toxicity. Methods Peripheral blood lymphocytes were isolated from 26 ALL patients 24 hours after TBI preconditioning (4.5 and 9 Gy, respectively. Extracted DNA was analyzed by real-time PCR method. Results Average 2.31 times mtDNA and 0.53 fold CD levels were observed after 4.5 Gy exposure compared to their basal levels. 9 Gy TBI produced a greater response of both mtDNA and CD levels than 4.5 Gy. Significant inverse correlation was found between mtDNA content and CD level at 4.5 and 9 Gy (P = 0.037 and 0.048. Moreover, mtDNA content of lymphocytes without irradiation was found to be correlated to age. Conclusions mtDNA and CD content may be considered as predictive factors to radiation toxicity.

  4. Mitochondrial DNA alterations in the progression of gastric carcinomas: unexplored issues and future research needs.

    Science.gov (United States)

    Rigoli, Luciana; Caruso, Rosario Alberto

    2014-11-21

    Gastric cancer is the second most frequent cause of cancer death worldwide. Patients infected with Helicobacter pylori (H. pylori) are at increased risk of gastric cancer. H. pylori induces genomic instability in both nuclear and mitochondrial (mt) DNA of gastric epithelial cells. Changes in mtDNA represent an early event during gastric tumorigenesis, and thus may serve as potential biomarkers for early detection and prognosis in gastric carcinoma.This review article summarizes the mtDNA mutations that have been reported in gastric carcinomas and their precancerous conditions. Unexplored research topics, such as the role of mtDNA alterations in an alternative pathway of gastric carcinogenesis, are identified and directions for future research are suggested. PMID:25473169

  5. Impaired glycogen synthase activity and mitochondrial dysfunction in skeletal muscle

    DEFF Research Database (Denmark)

    Højlund, Kurt; Beck-Nielsen, Henning

    2006-01-01

    Insulin resistance in skeletal muscle is a major hallmark of type 2 diabetes and an early detectable abnormality in the development of this disease. The cellular mechanisms of insulin resistance include impaired insulin-mediated muscle glycogen synthesis and increased intramyocellular lipid content...... expression analysis and proteomics have pointed to abnormalities in mitochondrial oxidative phosphorylation and cellular stress in muscle of type 2 diabetic subjects, and recent work suggests that impaired mitochondrial activity is another early defect in the pathogenesis of type 2 diabetes. This review will...... discuss the latest advances in the understanding of the molecular mechanisms underlying insulin resistance in human skeletal muscle in type 2 diabetes with focus on possible links between impaired glycogen synthase activity and mitochondrial dysfunction....

  6. Calcium-induced alteration of mitochondrial morphology and mitochondrial-endoplasmic reticulum contacts in rat brown adipocytes.

    Science.gov (United States)

    Golic, I; Velickovic, K; Markelic, M; Stancic, A; Jankovic, A; Vucetic, M; Otasevic, V; Buzadzic, B; Korac, B; Korac, A

    2014-01-01

    Mitochondria are key organelles maintaining cellular bioenergetics and integrity, and their regulation of [Ca2+]i homeostasis has been investigated in many cell types. We investigated the short-term Ca-SANDOZ® treatment on brown adipocyte mitochondria, using imaging and molecular biology techniques. Two-month-old male Wistar rats were divided into two groups: Ca-SANDOZ® drinking or tap water (control) drinking for three days. Alizarin Red S staining showed increased Ca2+ level in the brown adipocytes of treated rats, and potassium pyroantimonate staining localized electron-dense regions in the cytoplasm, mitochondria and around lipid droplets. Ca-SANDOZ® decreased mitochondrial number, but increased their size and mitochondrial cristae volume. Transmission electron microscopy revealed numerous enlarged and fusioned-like mitochondria in the Ca-SANDOZ® treated group compared to the control, and megamitochondria in some brown adipocytes. The Ca2+ diet affected mitochondrial fusion as mitofusin 1 (MFN1) and mitofusin 2 (MFN2) were increased, and mitochondrial fission as dynamin related protein 1 (DRP1) was decreased. Confocal microscopy showed a higher colocalization rate between functional mitochondria and endoplasmic reticulum (ER). The level of uncoupling protein-1 (UCP1) was elevated, which was confirmed by immunohistochemistry and Western blot analysis. These results suggest that Ca-SANDOZ® stimulates mitochondrial fusion, increases mitochondrial-ER contacts and the thermogenic capacity of brown adipocytes. PMID:25308841

  7. Altered mitochondrial dynamics and response to insulin in cybrid cells harboring a diabetes-susceptible mitochondrial DNA haplogroup.

    Science.gov (United States)

    Kuo, Hsiao-Mei; Weng, Shao-Wen; Chang, Alice Y W; Huang, Hung-Tu; Lin, Hung-Yu; Chuang, Jiin-Haur; Lin, Tsu-Kung; Liou, Chia-Wei; Tai, Ming-Hong; Lin, Ching-Yi; Wang, Pei-Wen

    2016-07-01

    The advantage of using a cytoplasmic hybrid (cybrid) model to study the genetic effects of mitochondria is that the cells have the same nuclear genomic background. We previously demonstrated the independent role of mitochondria in the pathogenesis of insulin resistance (IR) and pro-inflammation in type 2 diabetes. In this study, we compared mitochondrial dynamics and related physiological functions between cybrid cells harboring diabetes-susceptible (B4) and diabetes-protective (D4) mitochondrial haplogroups, especially the responses before and after insulin stimulation. Cybrid B4 showed a more fragmented mitochondrial network, impaired mitochondrial biogenesis and bioenergetics, increased apoptosis and ineffective mitophagy and a low expression of fusion-related molecules. Upon insulin stimulation, increases in network formation, mitochondrial DNA (mtDNA) content, and ATP production were observed only in cybrid D4. Insulin promoted a pro-fusion dynamic status in both cybrids, but the trend was greater in cybrid D4. In cybrid B4, the imbalance of mitochondrial dynamics and impaired biogenesis and bioenergetics, and increased apoptosis were significantly improved in response to antioxidant treatment. We concluded that diabetes-susceptible mtDNA variants are themselves resistant to insulin. PMID:27107769

  8. Calcium-induced alteration of mitochondrial morphology and mitochondrial-endoplasmic reticulum contacts in rat brown adipocytes

    Directory of Open Access Journals (Sweden)

    I. Golic

    2014-09-01

    Full Text Available Mitochondria are key organelles maintaining cellular bioenergetics and integrity, and their regulation of [Ca2+]i homeostasis has been investigated in many cell types. We investigated the short-term Ca-SANDOZ® treatment on brown adipocyte mitochondria, using imaging and molecular biology techniques. Two-month-old male Wistar rats were divided into two groups: Ca-SANDOZ® drinking or tap water (control drinking for three days. Alizarin Red S staining showed increased Ca2+ level in the brown adipocytes of treated rats, and potassium pyroantimonate staining localized electron-dense regions in the cytoplasm, mitochondria and around lipid droplets. Ca-SANDOZ® decreased mitochondrial number, but increased their size and mitochondrial cristae volume. Transmission electron microscopy revealed numerous enlarged and fusioned-like mitochondria in the Ca-SANDOZ® treated group compared to the control, and megamitochondria in some brown adipocytes. The Ca2+ diet affected mitochondrial fusion as mitofusin 1 (MFN1 and mitofusin 2 (MFN2 were increased, and mitochondrial fission as dynamin related protein 1 (DRP1 was decreased. Confocal microscopy showed a higher colocalization rate between functional mitochondria and endoplasmic reticulum (ER. The level of uncoupling protein-1 (UCP1 was elevated, which was confirmed by immunohistochemistry and Western blot analysis. These results suggest that Ca-SANDOZ® stimulates mitochondrial fusion, increases mitochondrial-ER contacts and the thermogenic capacity of brown adipocytes

  9. Impairment of brain mitochondrial charybdotoxin- and ATP-insensitive BK channel activities in diabetes.

    Science.gov (United States)

    Noursadeghi, E; Jafari, A; Saghiri, R; Sauve, R; Eliassi, A

    2014-12-01

    Existing evidence indicates an impairment of mitochondrial functions and alterations in potassium channel activities in diabetes. Because mitochondrial potassium channels have been involved in several mitochondrial functions including cytoprotection, apoptosis and calcium homeostasis, a study was carried out to consider whether the gating behavior of the mitochondrial ATP- and ChTx-insensitive Ca(2+)-activated potassium channel (mitoBKCa) is altered in a streptozotocin (STZ) model of diabetes. Using ion channel incorporation of brain mitochondrial inner membrane into the bilayer lipid membrane, we provide in this work evidence for modifications of the mitoBKCa ion permeation properties with channels from vesicles preparations coming from diabetic rats characterized by a significant decrease in conductance. More importantly, the open probability of channels from diabetic rats was reduced 1.5-2.5 fold compared to control, the most significant decrease being observed at depolarizing potentials. Because BKCa β4 subunit has been documented to left shift the BKCa channel voltage dependence curve in high Ca(2+) conditions, a Western blot analysis was undertaken where the expression of mitoBKCa α and β4 subunits was estimated using of anti-α and β4 subunit antibodies. Our results indicated a significant decrease in mitoBKCa β4 subunit expression coupled to a decrease in the expression of α subunit, an observation compatible with the observed decrease in Ca(2+) sensitivity. Our results thus demonstrate a modification in the mitoBKCa channel gating properties in membrane preparations coming from STZ model of diabetic rats, an effect potentially linked to a change in mitoBKCa β4 and α subunits expression and/or to an increase in reactive oxygen species production in high glucose conditions. PMID:25344764

  10. Sustained activation of Akt elicits mitochondrial dysfunction to block Plasmodium falciparum infection in the mosquito host.

    Directory of Open Access Journals (Sweden)

    Shirley Luckhart

    2013-02-01

    Full Text Available The overexpression of activated, myristoylated Akt in the midgut of female transgenic Anopheles stephensi results in resistance to infection with the human malaria parasite Plasmodium falciparum but also decreased lifespan. In the present study, the understanding of mitochondria-dependent midgut homeostasis has been expanded to explain this apparent paradox in an insect of major medical importance. Given that Akt signaling is essential for cell growth and survival, we hypothesized that sustained Akt activation in the mosquito midgut would alter the balance of critical pathways that control mitochondrial dynamics to enhance parasite killing at some cost to survivorship. Toxic reactive oxygen and nitrogen species (RNOS rise to high levels in the midgut after blood feeding, due to a combination of high NO production and a decline in FOXO-dependent antioxidants. Despite an apparent increase in mitochondrial biogenesis in young females (3 d, energy deficiencies were apparent as decreased oxidative phosphorylation and increased [AMP]/[ATP] ratios. In addition, mitochondrial mass was lower and accompanied by the presence of stalled autophagosomes in the posterior midgut, a critical site for blood digestion and stem cell-mediated epithelial maintenance and repair, and by functional degradation of the epithelial barrier. By 18 d, the age at which An. stephensi would transmit P. falciparum to human hosts, mitochondrial dysfunction coupled to Akt-mediated repression of autophagy/mitophagy was more evident and midgut epithelial structure was markedly compromised. Inhibition of RNOS by co-feeding of the nitric-oxide synthase inhibitor L-NAME at infection abrogated Akt-dependent killing of P. falciparum that begins within 18 h of infection in 3-5 d old mosquitoes. Hence, Akt-induced changes in mitochondrial dynamics perturb midgut homeostasis to enhance parasite resistance and decrease mosquito infective lifespan. Further, quality control of mitochondrial

  11. Grape seed proanthocyanidins promote apoptosis in human epidermoid carcinoma A431 cells through alterations in Cdki-Cdk-cyclin cascade, and caspase-3 activation via loss of mitochondrial membrane potential.

    Science.gov (United States)

    Meeran, Syed M; Katiyar, Santosh K

    2007-05-01

    Dietary grape seed proanthocyanidins (GSPs) prevent photocarcinogenesis in mice. Here, we report that in vitro treatment of human epidermoid carcinoma A431 cells with GSPs inhibited cellular proliferation (13-89%) and induced cell death (1-48%) in a dose (5-100 mug/ml)- and time (24, 48 and 72 h)-dependent manner. GSP-induced inhibition of cell proliferation was associated with an increase in G1-phase arrest at 24 h, which was mediated through the inhibition of cyclin-dependent kinases (Cdk) Cdk2, Cdk4, Cdk6 and cyclins D1, D2 and E and simultaneous increase in protein expression of cyclin-dependent kinase inhibitors (Cdki), Cip1/p21 and Kip1/p27, and enhanced binding of Cdki-Cdk. The treatment of A431 cells with GSPs (20-80 mug/ml) resulted in a dose-dependent increase in apoptotic cell death (26-58%), which was associated with an increased protein expression of proapoptotic Bax, decreased expression of antiapoptotic Bcl-2 and Bcl-xl, loss of mitochondrial membrane potential, and cleavage of caspase-9, caspase-3 and PARP. Pretreatment with the pan-caspase inhibitor (z-VAD-fmk) blocked the GSP-induced apoptosis in A431 cells suggesting that GSP-induced apoptosis is associated primarily with the caspase-3-dependent pathway. Together, our study suggests that GSPs possess chemotherapeutic potential against human epidermoid carcinoma cells in vitro, further in vivo mechanistic studies are required to verify the chemotherapeutic effect of GSPs in skin cancers. PMID:17437483

  12. The marine toxin, Yessotoxin, induces apoptosis and increases mitochondrial activity

    Directory of Open Access Journals (Sweden)

    Andrea Fernandez-Araujo

    2014-06-01

    Discussion: Colorimetric MTT assay is widely used as a viability measurement method (McHale and L., 1988;Chiba et al., 1998. But after YTX treatment, MTT assay had shown problems to detect a cell viability decrease. In this sense, in primary cardiac cell cultures, a false increment of the proliferation rate opposite to Sulforhodamine B assay (SRB results was reported after YTX treatment (Dell'Ovo et al., 2008. Also the same effect was obtained in different cancer cell lines after assaying anticancer therapies (Ulukaya et al., 2004. In our study, an increase in cell viability using MTT was observed when the number of cells was high, while by using the LDH assay a significant viability decrease was measured. In these conditions, YTX is activating extrinsic apoptosis cell death by increasing caspase 8 activity and caspase 3 levels. The explanation for this increase was found when the mitochondrial activity was quantified cell by cell in a cytometer. In these conditions a significant increment of mitochondrial activity was detected. Since the cell population is too high, the increase in mitochondrial activity that detects the MTT test disguised the decrease of signal due to the cell death and point to a false proliferation increase. In this sense, a mitochondrial activity decrease was observed after 48 hours YTX treatment in BE(2-M17 neuroblastoma cell line (Leira et al., 2002. However, this study was done in a microplate reader with a small number of cells (Leira et al., 2002. Therefore, to measure the viability by MTT assay is very important to take into account the number of cells per condition when the experiment is designed. Alternative assays, such as LDH test, independently of the direct mitochondrial activity, can be used.

  13. Oxygen glucose deprivation in rat hippocampal slice cultures results in alterations in carnitine homeostasis and mitochondrial dysfunction.

    Directory of Open Access Journals (Sweden)

    Thomas F Rau

    Full Text Available Mitochondrial dysfunction characterized by depolarization of mitochondrial membranes and the initiation of mitochondrial-mediated apoptosis are pathological responses to hypoxia-ischemia (HI in the neonatal brain. Carnitine metabolism directly supports mitochondrial metabolism by shuttling long chain fatty acids across the inner mitochondrial membrane for beta-oxidation. Our previous studies have shown that HI disrupts carnitine homeostasis in neonatal rats and that L-carnitine can be neuroprotective. Thus, this study was undertaken to elucidate the molecular mechanisms by which HI alters carnitine metabolism and to begin to elucidate the mechanism underlying the neuroprotective effect of L-carnitine (LCAR supplementation. Utilizing neonatal rat hippocampal slice cultures we found that oxygen glucose deprivation (OGD decreased the levels of free carnitines (FC and increased the acylcarnitine (AC: FC ratio. These changes in carnitine homeostasis correlated with decreases in the protein levels of carnitine palmitoyl transferase (CPT 1 and 2. LCAR supplementation prevented the decrease in CPT1 and CPT2, enhanced both FC and the AC∶FC ratio and increased slice culture metabolic viability, the mitochondrial membrane potential prior to OGD and prevented the subsequent loss of neurons during later stages of reperfusion through a reduction in apoptotic cell death. Finally, we found that LCAR supplementation preserved the structural integrity and synaptic transmission within the hippocampus after OGD. Thus, we conclude that LCAR supplementation preserves the key enzymes responsible for maintaining carnitine homeostasis and preserves both cell viability and synaptic transmission after OGD.

  14. Alterations of rat liver mitochondrial oxidative phosphorylation and calcium uptake by benzo[a]pyrene

    International Nuclear Information System (INIS)

    We report that oxidative phosphorylation and Ca2+ uptake processes are enhanced in liver mitochondria isolated from benzo[a]pyrene (B[a]P)-treated rats. The carcinogen did not affect either the respiratory control index or the Ca2+ control ratio. B[a]P treatment increased the oxidation rate of several substrates that donate electrons at the level of all three coupling sites, either the ADP- or Ca2+-stimulated rates or those observed after ADP or Ca2+ exhaustion. However, the efficiency of energy coupling was maintained because both ADP/O and Ca2+/site ratios remained unchanged. The electron flow through NADH-oxidase, NADH-duroquinone reductase, NADH-juglone reductase, NADH-cytochrome c reductase, succinate-cytochrome c reductase, and cytochrome c oxidase was enhanced by B[a]P; however, succinate dehydrogenase activity was not affected. All these effects depended on the time post B[a]P administration, with a greater increase close to 48 h after administration of the carcinogen. The contents of cytochromes b, c1, and a + a3 from liver mitochondria, especially those isolated 48 h after B[a]P, were also significantly increased, although cytochrome c levels was just lightly increased 24 h after B[a]P treatment. These results suggest that B[a]P treatment stimulates mitochondrial respiration by increasing the level of several components of the mitochondrial respiratory chain. This may reflect mitochondrial adaptation to the cellular energy requirements of cell division in the neoplastic transformation process

  15. Overfeeding reduces insulin sensitivity and increases oxidative stress, without altering markers of mitochondrial content and function in humans.

    Directory of Open Access Journals (Sweden)

    Dorit Samocha-Bonet

    Full Text Available BACKGROUND: Mitochondrial dysfunction and increased oxidative stress are associated with obesity and type 2 diabetes. High fat feeding induces insulin resistance and increases skeletal muscle oxidative stress in rodents, but there is controversy as to whether skeletal muscle mitochondrial biogenesis and function is altered. METHODOLOGY AND PRINCIPAL FINDINGS: Forty (37 ± 2 y non-obese (25.6 ± 0.6 kg/m(2 sedentary men (n = 20 and women (n = 20 were overfed (+1040 ± 100 kcal/day, 46 ± 1% of energy from fat for 28 days. Hyperinsulinemic-euglycemic clamps were performed at baseline and day 28 of overfeeding and skeletal muscle biopsies taken at baseline, day 3 and day 28 of overfeeding in a sub cohort of 26 individuals (13 men and 13 women that consented to having all 3 biopsies performed. Weight increased on average in the whole cohort by 0.6 ± 0.1 and 2.7 ± 0.3 kg at days 3 and 28, respectively (P<0.0001, without a significant difference in the response between men and women (P = 0.4. Glucose infusion rate during the hyperinsulinemic-euglycemic clamp decreased from 54.8 ± 2.8 at baseline to 50.3 ± 2.5 µmol/min/kg FFM at day 28 of overfeeding (P = 0.03 without a significant difference between men and women (P = 0.4. Skeletal muscle protein carbonyls and urinary F2-isoprostanes increased with overfeeding (P<0.05. Protein levels of muscle peroxisome proliferator-activated receptor gamma coactivator-1α (PGC1α and subunits from complex I, II and V of the electron transport chain were increased at day 3 (all P<0.05 and returned to basal levels at day 28. No changes were detected in muscle citrate synthase activity or ex vivo CO(2 production at either time point. CONCLUSIONS: Peripheral insulin resistance was induced by overfeeding, without reducing any of the markers of mitochondrial content that were examined. Oxidative stress was however increased, and may have contributed to the reduction in insulin sensitivity observed.

  16. The marine toxin, Yessotoxin, induces apoptosis and increases mitochondrial activity

    OpenAIRE

    Andrea Fernandez-Araujo; M. Mercedes Rodríguez Vieytes; Ana María Botana

    2014-01-01

    Abstract: Yessotoxin (YTX) group are phycotoxins produced by different species of dinoflagellates. YTX activates the Phosphodiesterases (PDEs). This group of toxins can be consumed by humans, however no intoxication events are reported. Controversial results by measuring cell viability with MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazoliumbromide) assay had been described. In this paper mitochondrial activity and cell death are studied through different viability tests, flow cytometry...

  17. Elevated PGC-1α Activity Sustains Mitochondrial Biogenesis and Muscle Function without Extending Survival in a Mouse Model of Inherited ALS

    OpenAIRE

    Da Cruz, Sandrine; Parone, Philippe A.; Lopes, Vanda S.; Lillo, Concepción; McAlonis-Downes, Melissa; Lee, Sandra K.; Vetto, Anne P.; Petrosyan, Susanna; Marsala, Martin; Murphy, Anne N.; Williams, David S.; Spiegelman, Bruce M.; Don W Cleveland

    2012-01-01

    The transcriptional coactivator PGC-1α induces multiple effects on muscle, including increased mitochondrial mass and activity. Amyotrophic lateral sclerosis (ALS) is a progressive, fatal, adult-onset neurodegenerative disorder characterized by selective loss of motor neurons and skeletal muscle degeneration. An early event is thought to be denervation-induced muscle atrophy accompanied by alterations in mitochondrial activity and morphology within muscle. We now report that elevation of PGC-...

  18. 4-Nitrobenzaldehyde thiosemicarbazone: a new compound derived from S-(-)-limonene that induces mitochondrial alterations in epimastigotes and trypomastigotes of Trypanosoma cruzi.

    Science.gov (United States)

    Britta, Elizandra Aparecida; Scariot, Débora Botura; Falzirolli, Hugo; da Silva, Cleuza Conceição; Ueda-Nakamura, Tânia; Dias Filho, Benedito Prado; Borsali, Redouane; Nakamura, Celso Vataru

    2015-06-01

    Trypanosoma cruzi is the causative agent of Chagas' disease, a parasitic disease that remains a serious health concern with unsatisfactory treatment. Drugs that are currently used to treat Chagas' disease are partially effective in the acute phase but ineffective in the chronic phase of the disease. The aim of the present study was to evaluate the antitrypanosomal activity and morphological, ultrastructural and biochemical alterations induced by a new molecule, 4-nitrobenzaldehyde thiosemicarbazone (BZTS), derived from S-(-)-limonene against epimastigote, trypomastigote and intracellular amastigote forms of T. cruzi. BZTS inhibited the growth of epimastigotes (IC50 = 9·2 μ m), intracellular amastigotes (IC50 = 3·23 μ m) and inhibited the viability of trypomastigotes (EC50 = 1·43 μ m). BZTS had a CC50 of 37·45 μ m in LLCMK2 cells. BZTS induced rounding and distortion of the cell body and severely damaged parasite mitochondria, reflected by extensive swelling and disorganization in the inner mitochondrial membrane and the presence of concentric membrane structures inside the organelle. Cytoplasmic vacuolization, endoplasmic reticulum that surrounded organelles, the loss of mitochondrial membrane potential, and increased mitochondrial O2 •- production were also observed. Our results suggest that BZTS alters the ultrastructure and physiology of mitochondria, which could be closely related to parasite death. PMID:25711881

  19. AMP-activated protein kinase mediates mitochondrial fission in response to energy stress

    Science.gov (United States)

    Courchet, Julien; Lewis, Tommy L.; Losón, Oliver C.; Hellberg, Kristina; Young, Nathan P.; Chen, Hsiuchen; Polleux, Franck; Chan, David C.; Shaw, Reuben J.

    2016-01-01

    Mitochondria undergo fragmentation in response to electron transport chain (ETC) poisons and mitochondrial DNA–linked disease mutations, yet how these stimuli mechanistically connect to the mitochondrial fission and fusion machinery is poorly understood. We found that the energy-sensing adenosine monophosphate (AMP)–activated protein kinase (AMPK) is genetically required for cells to undergo rapid mitochondrial fragmentation after treatment with ETC inhibitors. Moreover, direct pharmacological activation of AMPK was sufficient to rapidly promote mitochondrial fragmentation even in the absence of mitochondrial stress. A screen for substrates of AMPK identified mitochondrial fission factor (MFF), a mitochondrial outer-membrane receptor for DRP1, the cytoplasmic guanosine triphosphatase that catalyzes mitochondrial fission. Nonphosphorylatable and phosphomimetic alleles of the AMPK sites in MFF revealed that it is a key effector of AMPK-mediated mitochondrial fission. PMID:26816379

  20. Mitochondrial aerobic respiration is activated during hair follicle stem cell differentiation, and its dysfunction retards hair regeneration

    Science.gov (United States)

    Tang, Yan; Luo, Binping; Deng, Zhili; Wang, Ben; Liu, Fangfen; Li, Jinmao; Shi, Wei; Xie, Hongfu; Hu, Xingwang

    2016-01-01

    Background. Emerging research revealed the essential role of mitochondria in regulating stem/progenitor cell differentiation of neural progenitor cells, mesenchymal stem cells and other stem cells through reactive oxygen species (ROS), Notch or other signaling pathway. Inhibition of mitochondrial protein synthesis results in hair loss upon injury. However, alteration of mitochondrial morphology and metabolic function during hair follicle stem cells (HFSCs) differentiation and how they affect hair regeneration has not been elaborated upon. Methods. We compared the difference in mitochondrial morphology and activity between telogen bulge cells and anagen matrix cells. Expression levels of mitochondrial ROS and superoxide dismutase 2 (SOD2) were measured to evaluate redox balance. In addition, the level of pyruvate dehydrogenase kinase (PDK) and pyruvate dehydrogenase (PDH) were estimated to present the change in energetic metabolism during differentiation. To explore the effect of the mitochondrial metabolism on regulating hair regeneration, hair growth was observed after application of a mitochondrial respiratory inhibitor upon hair plucking. Results. During HFSCs differentiation, mitochondria became elongated with more abundant organized cristae and showed higher activity in differentiated cells. SOD2 was enhanced for redox balance with relatively stable ROS levels in differentiated cells. PDK increased in HFSCs while differentiated cells showed enhanced PDH, indicating that respiration switched from glycolysis to oxidative phosphorylation during differentiation. Inhibiting mitochondrial respiration in differentiated hair follicle cells upon hair plucking repressed hair regeneration in vivo. Conclusions. Upon HFSCs differentiation, mitochondria are elongated with more abundant cristae and show higher activity, accompanying with activated aerobic respiration in differentiated cells for higher energy supply. Also, dysfunction of mitochondrial respiration delays hair

  1. UBIAD1 mutation alters a mitochondrial prenyltransferase to cause Schnyder corneal dystrophy.

    Directory of Open Access Journals (Sweden)

    Michael L Nickerson

    Full Text Available Mutations in a novel gene, UBIAD1, were recently found to cause the autosomal dominant eye disease Schnyder corneal dystrophy (SCD. SCD is characterized by an abnormal deposition of cholesterol and phospholipids in the cornea resulting in progressive corneal opacification and visual loss. We characterized lesions in the UBIAD1 gene in new SCD families and examined protein homology, localization, and structure.We characterized five novel mutations in the UBIAD1 gene in ten SCD families, including a first SCD family of Native American ethnicity. Examination of protein homology revealed that SCD altered amino acids which were highly conserved across species. Cell lines were established from patients including keratocytes obtained after corneal transplant surgery and lymphoblastoid cell lines from Epstein-Barr virus immortalized peripheral blood mononuclear cells. These were used to determine the subcellular localization of mutant and wild type protein, and to examine cholesterol metabolite ratios. Immunohistochemistry using antibodies specific for UBIAD1 protein in keratocytes revealed that both wild type and N102S protein were localized sub-cellularly to mitochondria. Analysis of cholesterol metabolites in patient cell line extracts showed no significant alteration in the presence of mutant protein indicating a potentially novel function of the UBIAD1 protein in cholesterol biochemistry. Molecular modeling was used to develop a model of human UBIAD1 protein in a membrane and revealed potentially critical roles for amino acids mutated in SCD. Potential primary and secondary substrate binding sites were identified and docking simulations indicated likely substrates including prenyl and phenolic molecules.Accumulating evidence from the SCD familial mutation spectrum, protein homology across species, and molecular modeling suggest that protein function is likely down-regulated by SCD mutations. Mitochondrial UBIAD1 protein appears to have a highly

  2. The Parkinson Disease Mitochondrial Hypothesis: Where Are We at?

    Science.gov (United States)

    Franco-Iborra, Sandra; Vila, Miquel; Perier, Celine

    2016-06-01

    Parkinson's disease is a common, adult-onset neurodegenerative disorder whose pathogenesis is still under intense investigation. Substantial evidence from postmortem human brain tissue, genetic- and toxin-induced animal and cellular models indicates that mitochondrial dysfunction plays a central role in the pathophysiology of the disease. This review discusses our current understanding of Parkinson's disease-related mitochondrial dysfunction, including bioenergetic defects, mitochondrial DNA alterations, altered mitochondrial dynamics, activation of mitochondrial-dependent programmed cell death, and perturbations in mitochondrial tethering to the endoplasmic reticulum. Whether a primary or secondary event, mitochondrial dysfunction holds promise as a potential therapeutic target to halt the progression of neurodegeneration in Parkinson's disease. PMID:25761946

  3. The defective expression of gtpbp3 related to tRNA modification alters the mitochondrial function and development of zebrafish.

    Science.gov (United States)

    Chen, Danni; Li, Feng; Yang, Qingxian; Tian, Miao; Zhang, Zengming; Zhang, Qinghai; Chen, Ye; Guan, Min-Xin

    2016-08-01

    Human mitochondrial DNA (mtDNA) mutations have been associated with a wide spectrum of clinical abnormalities. However, nuclear modifier gene(s) modulate the phenotypic expression of pathogenic mtDNA mutations. In our previous investigation, we identified the human GTPBP3 related to mitochondrial tRNA modification, acting as a modifier to influence of deafness-associated mtDNA mutation. Mutations in GTPBP3 have been found to be associated with other human diseases. However, the pathophysiology of GTPBP3-associated disorders is still not fully understood. Here, we reported the generation and characterization of Gtpbp3 depletion zebrafish model using antisense morpholinos. Zebrafish gtpbp3 has three isoforms localized at mitochondria. Zebrafish gtpbp3 is expressed at various embryonic stages and in multiple tissues. In particular, the gtpbp3 was expressed more abundantly in adult zebrafish ovary and testis. The expression of zebrafish gtpbp3 can functionally restore the growth defects caused by the mss1/gtpbp3 mutation in yeast. A marked decrease of mitochondrial ATP generation accompanied by increased levels of apoptosis and reactive oxygen species were observed in gtpbp3 knockdown zebrafish embryos. The Gtpbp3 morphants exhibited defective in embryonic development including bleeding, melenin, oedema and curved tails within 5days post fertilization, as compared with uninjected controls. The co-injection of wild type gtpbp3 mRNA partially rescued these defects in Gtpbp3 morphants. These data suggest that zebrafish Gtpbp3 is a structural and functional homolog of human and yeast GTPBP3. The mitochondrial dysfunction caused by defective Gtpbp3 may alter the embryonic development in the zebrafish. In addition, this zebrafish model of mitochondrial disease may provide unique opportunities for studying defective tRNA modification, mitochondrial biogenesis, and pathophysiology of mitochondrial disorders. PMID:27184967

  4. Quadriceps exercise intolerance in patients with chronic obstructive pulmonary disease: the potential role of altered skeletal muscle mitochondrial respiration.

    Science.gov (United States)

    Gifford, Jayson R; Trinity, Joel D; Layec, Gwenael; Garten, Ryan S; Park, Song-Young; Rossman, Matthew J; Larsen, Steen; Dela, Flemming; Richardson, Russell S

    2015-10-15

    This study sought to determine if qualitative alterations in skeletal muscle mitochondrial respiration, associated with decreased mitochondrial efficiency, contribute to exercise intolerance in patients with chronic obstructive pulmonary disease (COPD). Using permeabilized muscle fibers from the vastus lateralis of 13 patients with COPD and 12 healthy controls, complex I (CI) and complex II (CII)-driven State 3 mitochondrial respiration were measured separately (State 3:CI and State 3:CII) and in combination (State 3:CI+CII). State 2 respiration was also measured. Exercise tolerance was assessed by knee extensor exercise (KE) time to fatigue. Per milligram of muscle, State 3:CI+CII and State 3:CI were reduced in COPD (P respiration represented qualitative changes in mitochondrial function, respiration states were examined as percentages of peak respiration (State 3:CI+CII), which revealed altered contributions from State 3:CI (Con 83.7 ± 3.4, COPD 72.1 ± 2.4%Peak, P respiration, but not State 2 respiration in COPD. Importantly, a diminished contribution of CI-driven respiration relative to the metabolically less-efficient CII-driven respiration (CI/CII) was also observed in COPD (Con 1.28 ± 0.09, COPD 0.81 ± 0.05, P exercise tolerance of the patients (r = 0.64, P respiration, which potentially contributes to the exercise intolerance associated with this disease. PMID:26272320

  5. Genetically enhancing mitochondrial antioxidant activity improves muscle function in aging

    OpenAIRE

    Umanskaya, Alisa; Santulli, Gaetano; Xie, Wenjun; Andersson, Daniel C; Reiken, Steven R.; Marks, Andrew R.

    2014-01-01

    Age-related muscle weakness has major adverse consequences on quality of life, increasing the risk of falls, fractures, and movement impairments. Albeit an increased oxidative state has been shown to contribute to age-dependent reduction in skeletal muscle function, little is known about the mechanisms connecting oxidation and muscle weakness. We show here that genetically enhancing mitochondrial antioxidant activity causes improved skeletal muscle function and voluntary exercise in aged mice...

  6. Targeted impairment of thymidine kinase 2 expression in cells induces mitochondrial DNA depletion and reveals molecular mechanisms of compensation of mitochondrial respiratory activity

    International Nuclear Information System (INIS)

    Highlights: → We impaired TK2 expression in Ost TK1- cells via siRNA-mediated interference (TK2-). → TK2 impairment caused severe mitochondrial DNA (mtDNA) depletion in quiescent cells. → Despite mtDNA depletion, TK2- cells show high cytochrome oxidase activity. → Depletion of mtDNA occurs without imbalance in the mitochondrial dNTP pool. → Nuclear-encoded ENT1, DNA-pol γ, TFAM and TP gene expression is lowered in TK2- cells. -- Abstract: The mitochondrial DNA (mtDNA) depletion syndrome comprises a clinically heterogeneous group of diseases characterized by reductions of the mtDNA abundance, without associated point mutations or rearrangements. We have developed the first in vitro model to study of mtDNA depletion due to reduced mitochondrial thymidine kinase 2 gene (TK2) expression in order to understand the molecular mechanisms involved in mtDNA depletion syndrome due to TK2 mutations. Small interfering RNA targeting TK2 mRNA was used to decrease TK2 expression in Ost TK1- cells, a cell line devoid of endogenous thymidine kinase 1 (TK1). Stable TK2-deficient cell lines showed a reduction of TK2 levels close to 80%. In quiescent conditions, TK2-deficient cells showed severe mtDNA depletion, also close to 80% the control levels. However, TK2-deficient clones showed increased cytochrome c oxidase activity, higher cytochrome c oxidase subunit I transcript levels and higher subunit II protein expression respect to control cells. No alterations of the deoxynucleotide pools were found, whereas a reduction in the expression of genes involved in nucleoside/nucleotide homeostasis (human equilibrative nucleoside transporter 1, thymidine phosphorylase) and mtDNA maintenance (DNA-polymerase γ, mitochondrial transcription factor A) was observed. Our findings highlight the importance of cellular compensatory mechanisms that enhance the expression of respiratory components to ensure respiratory activity despite profound depletion in mtDNA levels.

  7. Mitochondrial permeabilization without caspase activation mediates the increase of basal apoptosis in cells lacking Nrf2.

    Science.gov (United States)

    Ariza, Julia; González-Reyes, José A; Jódar, Laura; Díaz-Ruiz, Alberto; de Cabo, Rafael; Villalba, José Manuel

    2016-06-01

    Nuclear factor E2-related factor-2 (Nrf2) is a cap'n'collar/basic leucine zipper (b-ZIP) transcription factor which acts as sensor of oxidative and electrophilic stress. Low levels of Nrf2 predispose cells to chemical carcinogenesis but a dark side of Nrf2 function also exists because its unrestrained activation may allow the survival of potentially dangerous damaged cells. Since Nrf2 inhibition may be of therapeutic interest in cancer, and a decrease of Nrf2 activity may be related with degenerative changes associated with aging, it is important to investigate how the lack of Nrf2 function activates molecular mechanisms mediating cell death. Murine Embryonic Fibroblasts (MEFs) bearing a Nrf2 deletion (Nrf2KO) displayed diminished cellular growth rate and shortened lifespan compared with wild-type MEFs. Basal rates of DNA fragmentation and histone H2A.X phosphorylation were higher in Nrf2KO MEFs, although steady-state levels of reactive oxygen species were not significantly increased. Enhanced rates of apoptotic DNA fragmentation were confirmed in liver and lung tissues from Nrf2KO mice. Apoptosis in Nrf2KO MEFs was associated with a decrease of Bcl-2 but not Bax levels, and with the release of the mitochondrial pro-apoptotic factors cytochrome c and AIF. Procaspase-9 and Apaf-1 were also increased in Nrf2KO MEFs but caspase-3 was not activated. Inhibition of XIAP increased death in Nrf2KO but not in wild-type MEFs. Mitochondrial ultrastructure was also altered in Nrf2KO MEFs. Our results support that Nrf2 deletion produces mitochondrial dysfunction associated with mitochondrial permeabilization, increasing basal apoptosis through a caspase-independent and AIF-dependent pathway. PMID:27016073

  8. Alterations in mitochondrial DNA: a technique for the detection of irradiated BEEF

    International Nuclear Information System (INIS)

    DNA molecules are very sensitive to ionizing radiation, even at low doses. Strand breaks are easy to detect despite the generally low DNA content of foods, but such ruptures are not specific to radiation processing. In order to make DNA strand rupture more specific to radiation (other than by deep freezing) it appears necessary to isolate the irradiated DNA from cellular enzymes. This is the case for mitochondrial DNA that is protected from enzymatic reactions by the mitochondrial walls but not from radiation. It can be assumed that DNA strand breaks in mitochondria will be specific to ionizing radiation. The authors explain their methods to extract and analyse the mitochondrial DNA

  9. Alteration of ROS Homeostasis and Decreased Lifespan in S. cerevisiae Elicited by Deletion of the Mitochondrial Translocator FLX1

    Directory of Open Access Journals (Sweden)

    Teresa Anna Giancaspero

    2014-01-01

    Full Text Available This paper deals with the control exerted by the mitochondrial translocator FLX1, which catalyzes the movement of the redox cofactor FAD across the mitochondrial membrane, on the efficiency of ATP production, ROS homeostasis, and lifespan of S. cerevisiae. The deletion of the FLX1 gene resulted in respiration-deficient and small-colony phenotype accompanied by a significant ATP shortage and ROS unbalance in glycerol-grown cells. Moreover, the flx1Δ strain showed H2O2 hypersensitivity and decreased lifespan. The impaired biochemical phenotype found in the flx1Δ strain might be justified by an altered expression of the flavoprotein subunit of succinate dehydrogenase, a key enzyme in bioenergetics and cell regulation. A search for possible cis-acting consensus motifs in the regulatory region upstream SDH1-ORF revealed a dozen of upstream motifs that might respond to induced metabolic changes by altering the expression of Flx1p. Among these motifs, two are present in the regulatory region of genes encoding proteins involved in flavin homeostasis. This is the first evidence that the mitochondrial flavin cofactor status is involved in controlling the lifespan of yeasts, maybe by changing the cellular succinate level. This is not the only case in which the homeostasis of redox cofactors underlies complex phenotypical behaviours, as lifespan in yeasts.

  10. The Adipocyte-Expressed Forkhead Transcription Factor Foxc2 Regulates Metabolism Through Altered Mitochondrial Function

    OpenAIRE

    Lidell, Martin E.; Seifert, Erin L.; Westergren, Rickard; Heglind, Mikael; Gowing, Adrienne; Sukonina, Valentina; Arani, Zahra; Itkonen, Paula; Wallin, Simonetta; Westberg, Fredrik; Fernandez-Rodriguez, Julia; Laakso, Markku; Nilsson, Tommy; Peng, Xiao-Rong; Harper, Mary-Ellen

    2011-01-01

    OBJECTIVE Previous findings demonstrate that enhanced expression of the forkhead transcription factor Foxc2 in adipose tissue leads to a lean and insulin-sensitive phenotype. These findings prompted us to further investigate the role of Foxc2 in the regulation of genes of fundamental importance for metabolism and mitochondrial function. RESEARCH DESIGN AND METHODS The effects of Foxc2 on expression of genes involved in mitochondriogenesis and mitochondrial function were assessed by quantitati...

  11. Screening for active small molecules in mitochondrial complex I deficient patient's fibroblasts, reveals AICAR as the most beneficial compound.

    Directory of Open Access Journals (Sweden)

    Anna Golubitzky

    Full Text Available Congenital deficiency of the mitochondrial respiratory chain complex I (CI is a common defect of oxidative phosphorylation (OXPHOS. Despite major advances in the biochemical and molecular diagnostics and the deciphering of CI structure, function assembly and pathomechanism, there is currently no satisfactory cure for patients with mitochondrial complex I defects. Small molecules provide one feasible therapeutic option, however their use has not been systematically evaluated using a standardized experimental system. In order to evaluate potentially therapeutic compounds, we set up a relatively simple system measuring different parameters using only a small amount of patient's fibroblasts, in glucose free medium, where growth is highly OXPOS dependent. Ten different compounds were screened using fibroblasts derived from seven CI patients, harboring different mutations.5-Aminoimidazole-4-carboxamide ribotide (AICAR was found to be the most beneficial compound improving growth and ATP content while decreasing ROS production. AICAR also increased mitochondrial biogenesis without altering mitochondrial membrane potential (Δψ. Fluorescence microscopy data supported increased mitochondrial biogenesis and activation of the AMP activated protein kinase (AMPK. Other compounds such as; bezafibrate and oltipraz were rated as favorable while polyphenolic phytochemicals (resverastrol, grape seed extract, genistein and epigallocatechin gallate were found not significant or detrimental. Although the results have to be verified by more thorough investigation of additional OXPHOS parameters, preliminary rapid screening of potential therapeutic compounds in individual patient's fibroblasts could direct and advance personalized medical treatment.

  12. Sirtuin-3 (Sirt3) regulates skeletal muscle metabolism and insulin signaling via altered mitochondrial oxidation and reactive oxygen species production

    DEFF Research Database (Denmark)

    Jing, Enxuan; Emanuelli, Brice; Hirschey, Matthew D;

    2011-01-01

    Sirt3 is a member of the sirtuin family of protein deacetylases that is localized in mitochondria and regulates mitochondrial function. Sirt3 expression in skeletal muscle is decreased in models of type 1 and type 2 diabetes and regulated by feeding, fasting, and caloric restriction. Sirt3 knockout......, activation of JNK, increased serine and decreased tyrosine phosphorylation of IRS-1, and decreased insulin signaling. Thus, Sirt3 plays an important role in diabetes through regulation of mitochondrial oxidation, reactive oxygen species production, and insulin resistance in skeletal muscle....

  13. Implications of Altered Glutathione Metabolism in Aspirin-Induced Oxidative Stress and Mitochondrial Dysfunction in HepG2 Cells

    OpenAIRE

    Raza, Haider; John, Annie

    2012-01-01

    We have previously reported that acetylsalicylic acid (aspirin, ASA) induces cell cycle arrest, oxidative stress and mitochondrial dysfunction in HepG2 cells. In the present study, we have further elucidated that altered glutathione (GSH)-redox metabolism in HepG2 cells play a critical role in ASA-induced cytotoxicity. Using selected doses and time point for ASA toxicity, we have demonstrated that when GSH synthesis is inhibited in HepG2 cells by buthionine sulfoximine (BSO), prior to ASA tre...

  14. Adiponectin Increases Skeletal Muscle Mitochondrial Biogenesis by Suppressing Mitogen-Activated Protein Kinase Phosphatase-1

    OpenAIRE

    Qiao, Liping; Kinney, Brice; Yoo, Hyung sun; Lee, Bonggi; Schaack, Jerome; Shao, Jianhua

    2012-01-01

    Adiponectin enhances mitochondrial biogenesis and oxidative metabolism in skeletal muscle. This study aimed to investigate the underlying mechanisms through which adiponectin induces mitochondrial biogenesis in skeletal muscle. Mitochondrial contents, expression, and activation status of p38 mitogen-activated protein kinase (MAPK) and PPARγ coactivator 1α (PGC-1α) were compared between skeletal muscle samples from adiponectin gene knockout, adiponectin-reconstituted, and control mice. Adenovi...

  15. Impairment of the mitochondrial respiratory chain activity in diethylnitrosamine-induced rat hepatomas: possible involvement of oxygen free radicals.

    Science.gov (United States)

    Boitier, E; Merad-Boudia, M; Guguen-Guillouzo, C; Defer, N; Ceballos-Picot, I; Leroux, J P; Marsac, C

    1995-07-15

    Alterations in the energy metabolism of cancer cells have been reported for many years. However, the deleterious mechanisms involved in these deficiencies have not yet been clearly proved. The main goal of this study was to decipher the harmful mechanisms responsible for the respiratory chain deficiencies in the course of diethylnitrosamine (DENA)-induced rat hepatocarcinogenesis, where mitochondrial DNA abnormalities had been previously reported. The respiratory activity of freshly isolated hepatoma mitochondria, assessed by oxygen consumption experiments and enzymatic assays, presented a severe complex I deficiency 19 months after DENA treatment, and later on, in addition, a defective complex III activity. Since respiratory complex subunits are encoded by both nuclear and mitochondrial genes, we checked whether the respiratory chain defects were due to impaired synthesis processes. The specific immunodetection of complex I failed to show any alterations in the steady-state levels of both nuclear and mitochondrial encoded subunits in the hepatomas. Moreover, in vitro protein synthesis experiments carried out on freshly isolated hepatoma mitochondria did not bring to light any modifications in the synthesis of the mitochondrial subunits of the respiratory complexes, whatever the degree of tumor progression. Finally, Southern blot analysis of mitochondrial DNA did not show any major mitochondrial DNA rearrangements in DENA-induced hepatomas. Because the synthetic processes of respiratory complexes did not seem to be implicated in the respiratory chain impairment, these deficiencies could be partly ascribed to a direct toxic impact of highly reactive molecules on these complexes, thus impairing their function. The mitochondrial respiratory chain is an important generator of noxious, reactive oxygen free radicals such as superoxide and H2O2, which are normally catabolized by powerful antioxidant scavengers. Nineteen months after DENA treatment, a general collapse of

  16. Antioxidant activity of capsaicin on radiation-induced oxidation of murine hepatic mitochondrial membrane preparation

    Directory of Open Access Journals (Sweden)

    Gangabhagirathi R

    2015-06-01

    Full Text Available Ramachandran Gangabhagirathi,1 Ravi Joshi,2 1Bioorganic Division, 2Radiation and Photochemistry Division, Bhabha Atomic Research Center, Trombay, Mumbai, India Abstract: Capsaicin is the major capsaicinoid in chili peppers and is widely used as a spice. It is also used for topical applications in cases of peripheral neuropathy. The present study deals with its role in modulation of gamma radiation-induced damages of the biochemical constituents of rat liver mitochondrial membrane (RLM preparation. The extent of lipid hydroperoxide formation, depletion in protein thiols, and formation of protein carbonyls have been biochemically assessed in the presence of varying concentrations of capsaicin in RLM. Decrease in the activities of the important antioxidant enzyme superoxide dismutase, which is involved in the scavenging of free radicals, and the mitochondrial marker enzyme succinate dehydrogenase have been also looked into. Capsaicin has been found to efficiently inhibit radiation-induced biochemical alterations, namely lipid peroxidation and protein oxidation. It also significantly prevented radiation-induced loss in the activity of antioxidant enzyme and the important endogenous antioxidant glutathione. The study suggests that capsaicin can act as an antioxidant and radioprotector in physiological systems. Keywords: capsaicin, gamma radiation, radioprotection, lipid peroxidation, protein oxidation, enzyme activity

  17. Activation of brown adipose tissue mitochondrial GDP binding sites

    International Nuclear Information System (INIS)

    The primary function of brown adipose tissue (BAT) is heat production. This ability is attributed to the existence of a unique inner mitochondrial membrane protein termed the uncoupling protein or thermogenin. This protein is permeable to H+ and thus allows respiration (and therefore thermogenesis) to proceed at a rapid rate, independent of ADP phosphorylation. Proton conductance can be inhibited by the binding of purine nucleotides to the uncoupling protein. The binding of [3H]-GDP to BAT mitochondria is frequently used as a measure of BAT thermogenic activity. Rats fed a diet that was low but adequate in protein exhibited a decrease in feed efficiency. In addition, BAT thermogenesis was activated as indicated by an elevation in the level of GDP binding to BAT mitochondria. This phenomena occurred in older rats and persisted over time

  18. Activation of brown adipose tissue mitochondrial GDP binding sites

    Energy Technology Data Exchange (ETDEWEB)

    Swick, A.G.

    1987-01-01

    The primary function of brown adipose tissue (BAT) is heat production. This ability is attributed to the existence of a unique inner mitochondrial membrane protein termed the uncoupling protein or thermogenin. This protein is permeable to H+ and thus allows respiration (and therefore thermogenesis) to proceed at a rapid rate, independent of ADP phosphorylation. Proton conductance can be inhibited by the binding of purine nucleotides to the uncoupling protein. The binding of (/sup 3/H)-GDP to BAT mitochondria is frequently used as a measure of BAT thermogenic activity. Rats fed a diet that was low but adequate in protein exhibited a decrease in feed efficiency. In addition, BAT thermogenesis was activated as indicated by an elevation in the level of GDP binding to BAT mitochondria. This phenomena occurred in older rats and persisted over time.

  19. Alterations in voltage-sensing of the mitochondrial permeability transition pore in ANT1-deficient cells.

    Science.gov (United States)

    Doczi, Judit; Torocsik, Beata; Echaniz-Laguna, Andoni; Mousson de Camaret, Bénédicte; Starkov, Anatoly; Starkova, Natalia; Gál, Aniko; Molnár, Mária J; Kawamata, Hibiki; Manfredi, Giovanni; Adam-Vizi, Vera; Chinopoulos, Christos

    2016-01-01

    The probability of mitochondrial permeability transition (mPT) pore opening is inversely related to the magnitude of the proton electrochemical gradient. The module conferring sensitivity of the pore to this gradient has not been identified. We investigated mPT's voltage-sensing properties elicited by calcimycin or H2O2 in human fibroblasts exhibiting partial or complete lack of ANT1 and in C2C12 myotubes with knocked-down ANT1 expression. mPT onset was assessed by measuring in situ mitochondrial volume using the 'thinness ratio' and the 'cobalt-calcein' technique. De-energization hastened calcimycin-induced swelling in control and partially-expressing ANT1 fibroblasts, but not in cells lacking ANT1, despite greater losses of mitochondrial membrane potential. Matrix Ca(2+) levels measured by X-rhod-1 or mitochondrially-targeted ratiometric biosensor 4mtD3cpv, or ADP-ATP exchange rates did not differ among cell types. ANT1-null fibroblasts were also resistant to H2O2-induced mitochondrial swelling. Permeabilized C2C12 myotubes with knocked-down ANT1 exhibited higher calcium uptake capacity and voltage-thresholds of mPT opening inferred from cytochrome c release, but intact cells showed no differences in calcimycin-induced onset of mPT, irrespective of energization and ANT1 expression, albeit the number of cells undergoing mPT increased less significantly upon chemically-induced hypoxia than control cells. We conclude that ANT1 confers sensitivity of the pore to the electrochemical gradient. PMID:27221760

  20. PPAR-α agonism improves whole body and muscle mitochondrial fat oxidation, but does not alter intracellular fat concentrations in burn trauma children in a randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Dohm G Lynis

    2007-04-01

    Full Text Available Abstract Background Insulin resistance is often associated with increased levels of intracellular triglycerides, diacylglycerol and decreased fat β-oxidation. It was unknown if this relationship was present in patients with acute insulin resistance induced by trauma. Methods A double blind placebo controlled trial was conducted in 18 children with severe burn injury. Metabolic studies to assess whole body palmitate oxidation and insulin sensitivity, muscle biopsies for mitochondrial palmitate oxidation, diacylglycerol, fatty acyl Co-A and fatty acyl carnitine concentrations, and magnetic resonance spectroscopy for muscle and liver triglycerides were compared before and after two weeks of placebo or PPAR-α agonist treatment. Results Insulin sensitivity and basal whole body palmitate oxidation as measured with an isotope tracer increased significantly (P = 0.003 and P = 0.004, respectively after PPAR-α agonist treatment compared to placebo. Mitochondrial palmitate oxidation rates in muscle samples increased significantly after PPAR-α treatment (P = 0.002. However, the concentrations of muscle triglyceride, diacylglycerol, fatty acyl CoA, fatty acyl carnitine, and liver triglycerides did not change with either treatment. PKC-θ activation during hyper-insulinemia decreased significantly following PPAR-α treatment. Conclusion PPAR-α agonist treatment increases palmitate oxidation and decreases PKC activity along with reduced insulin sensitivity in acute trauma, However, a direct link between these responses cannot be attributed to alterations in intracellular lipid concentrations.

  1. DJ-1 binds to mitochondrial complex I and maintains its activity

    International Nuclear Information System (INIS)

    Parkinson's disease (PD) is caused by neuronal cell death, and oxidative stress and mitochondrial dysfunction are thought to be responsible for onset of PD. DJ-1, a causative gene product of a familial form of Parkinson's disease, PARK7, plays roles in transcriptional regulation and anti-oxidative stress. The possible mitochondrial function of DJ-1 has been proposed, but its exact function remains unclear. In this study, we found that DJ-1 directly bound to NDUFA4 and ND1, nuclear and mitochondrial DNA-encoding subunits of mitochondrial complex I, respectively, and was colocalized with complex I and that complex I activity was reduced in DJ-1-knockdown NIH3T3 and HEK293 cells. These findings suggest that DJ-1 is an integral mitochondrial protein and that DJ-1 plays a role in maintenance of mitochondrial complex I activity.

  2. Sensitivity to Alternaria alternata toxin in citrus because of altered mitochondrial RNA processing

    OpenAIRE

    Ohtani, Kouhei; Yamamoto, Hiroyuki; Akimitsu, Kazuya

    2002-01-01

    Specificity in the interaction between rough lemon (Citrus jambhiri Lush.) and the fungal pathogen Alternaria alternata rough lemon pathotype is determined by a host-selective toxin, ACR-toxin. Mitochondria from rough lemon are sensitive to ACR-toxin whereas mitochondria from resistant plants, including other citrus species, are resistant. We have identified a C. jambhiri mitochondrial DNA sequence, designated ACRS (ACR-toxin sensitivity gene), that confers toxin sensitivity to Escherichia co...

  3. Association between mitochondrial C-tract alteration and tobacco exposure in oral precancer cases

    OpenAIRE

    Pandey, Rahul; Mehrotra, Divya; Mahdi, Abbas Ali; Sarin, Rajiv; Kowtal, Pradnya; Maurya, Shailendra S.; Parmar, Devendra

    2013-01-01

    Introduction: Tobacco exposure is a known risk factor for oral cancer. India is home to oral cancer epidemic chiefly due to the prevalent use of both smoke and smokeless tobacco. To reduce the related morbidity early detection is required. The key to this is detailing molecular events during early precancer stage. Mitochondrion is an important cellular organelle involved in cell metabolism and apoptosis. Mitochondrial dysfunction is thought to be the key event in oncogenesis. Last decade has ...

  4. Altered Mitochondrial Function and Oxidative Stress in Leukocytes of Anorexia Nervosa Patients

    OpenAIRE

    Victor, Victor M.; Rovira-Llopis, Susana; Saiz-Alarcon, Vanessa; Sangüesa, Maria C.; Rojo-Bofill, Luis; Bañuls, Celia; Falcón, Rosa; Castelló, Raquel; Rojo, Luis; Rocha, Milagros; Hernández-Mijares, Antonio

    2014-01-01

    Context Anorexia nervosa is a common illness among adolescents and is characterised by oxidative stress. Objective The effects of anorexia on mitochondrial function and redox state in leukocytes from anorexic subjects were evaluated. Design and setting A multi-centre, cross-sectional case-control study was performed. Patients Our study population consisted of 20 anorexic patients and 20 age-matched controls, all of which were Caucasian women. Main outcome measures Anthropometric and metabolic...

  5. Compartment-dependent mitochondrial alterations in experimental ALS, the effects of mitophagy and mitochondriogenesis

    OpenAIRE

    Natale, Gianfranco; Lenzi, Paola; Lazzeri, Gloria; Falleni, Alessandra; Biagioni, Francesca; Ryskalin, Larisa; Fornai, Francesco

    2015-01-01

    Amyotrophic lateral sclerosis (ALS) is characterized by massive loss of motor neurons. Data from ALS patients and experimental models indicate that mitochondria are severely damaged within dying or spared motor neurons. Nonetheless, recent data indicate that mitochondrial preservation, although preventing motor neuron loss, fails to prolong lifespan. On the other hand, the damage to motor axons plays a pivotal role in determining both lethality and disease course. Thus, in the present article...

  6. Mitochondrial dynamics and bioenergetic dysfunction is associated with synaptic alterations in mutant SOD1 motor neurons

    OpenAIRE

    Magrané, Jordi; Sahawneh, Mary Anne; Przedborski, Serge; Estévez, Álvaro G.; Manfredi, Giovanni

    2012-01-01

    Mutations in Cu,Zn superoxide dismutase (SOD1) cause familial amyotrophic lateral sclerosis (FALS), a rapidly fatal motor neuron disease. Mutant SOD1 has pleiotropic toxic effects on motor neurons, among which mitochondrial dysfunction has been proposed as one of the contributing factors in motor neuron demise. Mitochondria are highly dynamic in neurons; they are constantly reshaped by fusion and move along neurites to localize at sites of high-energy utilization, such as synapses. The findin...

  7. Significance of somatic mutations and content alteration of mitochondrial DNA in esophageal cancer

    OpenAIRE

    Wang Yu-Fen; Bai Ren-Kui; Liu Ling-Ling; Chang Julia; Tan Duan-Jun; Yeh Kun-Tu; Wong Lee-Jun C

    2006-01-01

    Abstract Background The roles of mitochondria in energy metabolism, the generation of ROS, aging, and the initiation of apoptosis have implicated their importance in tumorigenesis. In this study we aim to establish the mutation spectrum and to understand the role of somatic mtDNA mutations in esophageal cancer. Methods The entire mitochondrial genome was screened for somatic mutations in 20 pairs (18 esophageal squamous cell carcinomas, one adenosquamous carcinoma and one adenocarcinoma) of t...

  8. Mitochondrial oxidative phosphorylation transcriptome alterations in human amyotrophic lateral sclerosis spinal cord and blood.

    Science.gov (United States)

    Ladd, Amy C; Keeney, Paula M; Govind, Maria M; Bennett, James P

    2014-12-01

    Origins of onset and progression of motor neurodegeneration in amyotrophic lateral sclerosis (ALS) are not clearly known, but may include impairment of mitochondrial bioenergetics. We used quantitative PCR approaches to analyze the mitochondrial oxidative phosphorylation (OXPHOS) transcriptomes of spinal cord tissue and peripheral blood mononuclear cells (PBMC) from persons with sporadic ALS compared with those without neurological disease. Expression measurements of 88 different nuclear (n) and mitochondrial (mt) DNA-encoded OXPHOS genes showed mtDNA-encoded respiratory gene expression was significantly decreased in ALS spinal cord by 78-84% (ANOVA p < 0.002). We observed the same phenomenon in freshly isolated PBMC from ALS patients (reduced 24-35%, ANOVA p < 0.001) and reproduced it in a human neural stem cell model treated with 2',3'-dideoxycytidine (ddC) (reduced 52-78%, ANOVA p < 0.001). nDNA-encoded OXPHOS genes showed heterogeneously and mostly decreased expression in ALS spinal cord tissue. In contrast, ALS PBMC and ddC-treated stem cells showed no significant change in expression of nDNA OXPHOS genes compared with controls. Genes related to mitochondrial biogenesis (PGC-1α, TFAM, ERRα, NRF1, NRF2 and POLG) were queried with inconclusive results. Here, we demonstrate there is a systemic decrease in mtDNA gene expression in ALS central and peripheral tissues that support pursuit of bioenergetic-enhancing therapies. We also identified a combined nDNA and mtDNA gene set (n = 26), downregulated in spinal cord tissue that may be useful as a biomarker in the development of cell-based ALS models. PMID:25081190

  9. Targeted impairment of thymidine kinase 2 expression in cells induces mitochondrial DNA depletion and reveals molecular mechanisms of compensation of mitochondrial respiratory activity

    Energy Technology Data Exchange (ETDEWEB)

    Villarroya, Joan, E-mail: joanvillarroya@gmail.com [Institut de Recerca, Hospital Universitari de la Vall d' Hebron, Barcelona (Spain); Institut de Recerca l' Hospital de la Santa Creu i Sant Pau, Barcelona (Spain); Lara, Mari-Carmen [Institut de Recerca, Hospital Universitari de la Vall d' Hebron, Barcelona (Spain); Department of Neurology, Columbia University Medical Center, New York, NY (United States); Centro de Investigacion Biomedica en Red de Enfermedades Raras (CIBERER), ISCIII (Spain); Dorado, Beatriz [Department of Neurology, Columbia University Medical Center, New York, NY (United States); Garrido, Marta [Unitat de Biologia Cel.lular i Molecular, IMIM-Hospital del Mar, Barcelona (Spain); Garcia-Arumi, Elena [Institut de Recerca, Hospital Universitari de la Vall d' Hebron, Barcelona (Spain); Centro de Investigacion Biomedica en Red de Enfermedades Raras (CIBERER), ISCIII (Spain); Meseguer, Anna [Institut de Recerca, Hospital Universitari de la Vall d' Hebron, Barcelona (Spain); Hirano, Michio [Department of Neurology, Columbia University Medical Center, New York, NY (United States); Vila, Maya R. [Institut de Recerca, Hospital Universitari de la Vall d' Hebron, Barcelona (Spain)

    2011-04-08

    Highlights: {yields} We impaired TK2 expression in Ost TK1{sup -} cells via siRNA-mediated interference (TK2{sup -}). {yields} TK2 impairment caused severe mitochondrial DNA (mtDNA) depletion in quiescent cells. {yields} Despite mtDNA depletion, TK2{sup -} cells show high cytochrome oxidase activity. {yields} Depletion of mtDNA occurs without imbalance in the mitochondrial dNTP pool. {yields} Nuclear-encoded ENT1, DNA-pol {gamma}, TFAM and TP gene expression is lowered in TK2{sup -} cells. -- Abstract: The mitochondrial DNA (mtDNA) depletion syndrome comprises a clinically heterogeneous group of diseases characterized by reductions of the mtDNA abundance, without associated point mutations or rearrangements. We have developed the first in vitro model to study of mtDNA depletion due to reduced mitochondrial thymidine kinase 2 gene (TK2) expression in order to understand the molecular mechanisms involved in mtDNA depletion syndrome due to TK2 mutations. Small interfering RNA targeting TK2 mRNA was used to decrease TK2 expression in Ost TK1{sup -} cells, a cell line devoid of endogenous thymidine kinase 1 (TK1). Stable TK2-deficient cell lines showed a reduction of TK2 levels close to 80%. In quiescent conditions, TK2-deficient cells showed severe mtDNA depletion, also close to 80% the control levels. However, TK2-deficient clones showed increased cytochrome c oxidase activity, higher cytochrome c oxidase subunit I transcript levels and higher subunit II protein expression respect to control cells. No alterations of the deoxynucleotide pools were found, whereas a reduction in the expression of genes involved in nucleoside/nucleotide homeostasis (human equilibrative nucleoside transporter 1, thymidine phosphorylase) and mtDNA maintenance (DNA-polymerase {gamma}, mitochondrial transcription factor A) was observed. Our findings highlight the importance of cellular compensatory mechanisms that enhance the expression of respiratory components to ensure respiratory activity

  10. Diabetes or peroxisome proliferator-activated receptor alpha agonist increases mitochondrial thioesterase I activity in heart

    Science.gov (United States)

    Peroxisome proliferator-activated receptor alpha (PPAR alpha) is a transcriptional regulator of the expression of mitochondrial thioesterase I (MTE-I) and uncoupling protein 3 (UCP3), which are induced in the heart at the mRNA level in response to diabetes. Little is known about the regulation of pr...

  11. Levetiracetam differentially alters CD95 expression of neuronal cells and the mitochondrial membrane potential of immune and neuronal cells in vitro

    Directory of Open Access Journals (Sweden)

    LeeAShapiro

    2014-02-01

    Full Text Available Epilepsy is a neurological seizure disorder that affects over 100 million people worldwide. Levetiracetam, either alone, as monotherapy, or as adjunctive treatment, is widely used to control certain types of seizures. Despite its increasing popularity as a relatively safe and effective anti-convulsive treatment option, its mechanism(s of action are poorly understood. Studies have suggested neuronal, glial, and immune mechanisms of action. Understanding the precise mechanisms of action of Levetiracetam would be extremely beneficial in helping to understand the processes involved in seizure generation and epilepsy. Moreover, a full understanding of these mechanisms would help to create more efficacious treatments while minimizing side effects. The current study examined the effects of Levetiracetam on the mitochondrial membrane potential of neuronal and non-neuronal cells, in vitro, in order to determine if Levetiracetam influences metabolic processes in these cell types. In addition, this study sought to address possible immune-mediated mechanisms by determining if Levetiracetam alters the expression of immune receptor-ligand pairs. The results show that Levetiracetam induces expression of CD95 and CD178 on NGF-treated C17.2 neuronal cells. The results also show that Levetiracetam increases mitochondrial membrane potential on C17.2 neuronal cells in the presence of nerve growth factor. In contrast, Levetiracetam decreases the mitochondrial membrane potential of splenocytes and this effect was dependent on intact invariant chain, thus implicating immune cell interactions. These results suggest that both neuronal and non-neuronal anti-epileptic activities of Levetiracetam involve control over energy metabolism, more specifically, mΔΨ. Future studies are needed to further investigate this potential mechanism of action.

  12. Exercise improves import of 8-oxoguanine DNA glycosylase into the mitochondrial matrix of skeletal muscle and enhances the relative activity

    OpenAIRE

    Radak, Zsolt; Atalay, Mustafa; Jakus, Judit; Boldogh, István; Davies, Kelvin; Goto, Sataro

    2008-01-01

    Exercise has been shown to modify the level/activity of the DNA damage repair enzyme 8-oxoguanine-DNA glycosylase (OGG1) in skeletal muscle. We have studied the impact of regular physical training (8 weeks of swimming) and detraining (8 weeks of rest after an 8-week training session) on the activity of OGG1 in the nucleus and mitochondria as well as its targeting to the mitochondrial matrix in skeletal muscle. Neither exercise training nor detraining altered the overall levels of reactive spe...

  13. Changes in mitochondrial DNA alter expression of nuclear encoded genes associated with tumorigenesis

    International Nuclear Information System (INIS)

    We previously reported the presence of a mtDNA mutation hotspot in UV-induced premalignant and malignant skin tumors in hairless mice. We have modeled this change (9821insA) in murine cybrid cells and demonstrated that this alteration in mtDNA associated with mtBALB haplotype can alter the biochemical characteristics of cybrids and subsequently can contribute to significant changes in their behavioral capabilities. This study shows that changes in mtDNA can produce differences in expression levels of specific nuclear-encoded genes, which are capable of triggering the phenotypes such as seen in malignant cells. From a potential list of differentially expressed genes discovered by microarray analysis, we selected MMP-9 and Col1a1 for further studies. Real-time PCR confirmed up-regulation of MMP-9 and down-regulation of Col1a1 in cybrids harboring the mtDNA associated with the skin tumors. These cybrids also showed significantly increased migration and invasion abilities compared to wild type. The non-specific MMP inhibitor, GM6001, was able to inhibit migratory and invasive abilities of the 9821insA cybrids confirming a critical role of MMPs in cellular motility. Nuclear factor-κB (NF-κB) is a key transcription factor for production of MMPs. An inhibitor of NF-κB activation, Bay 11-7082, was able to inhibit the expression of MMP-9 and ultimately decrease migration and invasion of mutant cybrids containing 9821insA. These studies confirm a role of NF-κB in the regulation of MMP-9 expression and through this regulation modulates the migratory and invasive capabilities of cybrids with mutant mtDNA. Enhanced migration and invasion abilities caused by up-regulated MMP-9 may contribute to the tumorigenic phenotypic characteristics of mutant cybrids. -- Highlights: ► Cybrids are useful models to study the role of mtDNA changes in cancer development. ► mtDNA changes affect the expression of nuclear genes associated with tumorigenesis. ► MMP-9 is up-regulated and

  14. Changes in mitochondrial DNA alter expression of nuclear encoded genes associated with tumorigenesis

    Energy Technology Data Exchange (ETDEWEB)

    Jandova, Jana; Janda, Jaroslav [Southern Arizona VA Healthcare System, Department of Medicine, Dermatology Division and Arizona Cancer Center, University of Arizona, 1515 N Campbell Avenue, Tucson, AZ 857 24 (United States); Sligh, James E, E-mail: jsligh@azcc.arizona.edu [Southern Arizona VA Healthcare System, Department of Medicine, Dermatology Division and Arizona Cancer Center, University of Arizona, 1515 N Campbell Avenue, Tucson, AZ 857 24 (United States)

    2012-10-15

    We previously reported the presence of a mtDNA mutation hotspot in UV-induced premalignant and malignant skin tumors in hairless mice. We have modeled this change (9821insA) in murine cybrid cells and demonstrated that this alteration in mtDNA associated with mtBALB haplotype can alter the biochemical characteristics of cybrids and subsequently can contribute to significant changes in their behavioral capabilities. This study shows that changes in mtDNA can produce differences in expression levels of specific nuclear-encoded genes, which are capable of triggering the phenotypes such as seen in malignant cells. From a potential list of differentially expressed genes discovered by microarray analysis, we selected MMP-9 and Col1a1 for further studies. Real-time PCR confirmed up-regulation of MMP-9 and down-regulation of Col1a1 in cybrids harboring the mtDNA associated with the skin tumors. These cybrids also showed significantly increased migration and invasion abilities compared to wild type. The non-specific MMP inhibitor, GM6001, was able to inhibit migratory and invasive abilities of the 9821insA cybrids confirming a critical role of MMPs in cellular motility. Nuclear factor-{kappa}B (NF-{kappa}B) is a key transcription factor for production of MMPs. An inhibitor of NF-{kappa}B activation, Bay 11-7082, was able to inhibit the expression of MMP-9 and ultimately decrease migration and invasion of mutant cybrids containing 9821insA. These studies confirm a role of NF-{kappa}B in the regulation of MMP-9 expression and through this regulation modulates the migratory and invasive capabilities of cybrids with mutant mtDNA. Enhanced migration and invasion abilities caused by up-regulated MMP-9 may contribute to the tumorigenic phenotypic characteristics of mutant cybrids. -- Highlights: Black-Right-Pointing-Pointer Cybrids are useful models to study the role of mtDNA changes in cancer development. Black-Right-Pointing-Pointer mtDNA changes affect the expression of nuclear

  15. Reversible lysine acetylation controls the activity of the mitochondrial enzyme acetyl-CoA synthetase 2

    DEFF Research Database (Denmark)

    Schwer, Bjoern; Bunkenborg, Jakob; Verdin, Regis O; Andersen, Jens S; Verdin, Eric

    2006-01-01

    We report that human acetyl-CoA synthetase 2 (AceCS2) is a mitochondrial matrix protein. AceCS2 is reversibly acetylated at Lys-642 in the active site of the enzyme. The mitochondrial sirtuin SIRT3 interacts with AceCS2 and deacetylates Lys-642 both in vitro and in vivo. Deacetylation of AceCS2 b...

  16. Mitochondrial alterations produced by misonidazole: a study using Amoeba proteus as a single cell model

    International Nuclear Information System (INIS)

    Misonidazole (MISO) is undergoing clinical trials because of its radiosensitizing and cytotoxic effects. Amoeba proteus was used as a single-cell model to study the mechanism of the action of MISO on aerobic and hypoxic cells. Preliminary ultrastructural findings with MISO treatment of aerobic amoebae are reported. Morphological changes to the mitochondria were noted, which included the generation of matrical inclusions. In earlier investigations similar changes of form have been correlated with a disruption of mitochondrial functioning, and the possible significance of the present results is discussed in the light of these. (author)

  17. Altered expression of mitochondrial and extracellular matrix genes in the heart of human fetuses with chromosome 21 trisomy

    Directory of Open Access Journals (Sweden)

    Olla Carlo

    2007-08-01

    Full Text Available Abstract Background The Down syndrome phenotype has been attributed to overexpression of chromosome 21 (Hsa21 genes. However, the expression profile of Hsa21 genes in trisomic human subjects as well as their effects on genes located on different chromosomes are largely unknown. Using oligonucleotide microarrays we compared the gene expression profiles of hearts of human fetuses with and without Hsa21 trisomy. Results Approximately half of the 15,000 genes examined (87 of the 168 genes on Hsa21 were expressed in the heart at 18–22 weeks of gestation. Hsa21 gene expression was globally upregulated 1.5 fold in trisomic samples. However, not all genes were equally dysregulated and 25 genes were not upregulated at all. Genes located on other chromosomes were also significantly dysregulated. Functional class scoring and gene set enrichment analyses of 473 genes, differentially expressed between trisomic and non-trisomic hearts, revealed downregulation of genes encoding mitochondrial enzymes and upregulation of genes encoding extracellular matrix proteins. There were no significant differences between trisomic fetuses with and without heart defects. Conclusion We conclude that dosage-dependent upregulation of Hsa21 genes causes dysregulation of the genes responsible for mitochondrial function and for the extracellular matrix organization in the fetal heart of trisomic subjects. These alterations might be harbingers of the heart defects associated with Hsa21 trisomy, which could be based on elusive mechanisms involving genetic variability, environmental factors and/or stochastic events.

  18. Changed mitochondrial function by pre- and/or postpartum diet alterations in sheep

    DEFF Research Database (Denmark)

    Jørgensen, Wenche; Gam, Christiane Marie Bourgin; Andersen, Jesper Løvind;

    2009-01-01

    In a sheep model, we investigated diet effects on skeletal muscle mitochondria to look for fetal programming. During pregnancy, ewes were fed normally (N) or were 50% food restricted (L) during the last trimester, and lambs born to these ewes received a normal (N) or a high-fat diet (H) for the...... first 6 mo of life. We examined mitochondrial function in permeabilized muscle fibers from the lambs at 6 mo of age (adolescence) and after 24 mo of age (adulthood). The postpartum H diet for the lambs induced an approximately 30% increase (P < 0.05) of mitochondrial VO(2max) and an approximately 50......% increase (P < 0.05) of the respiratory coupling ratio (RCR) combined with lower levels of UCP3 and PGC-1alpha mRNA levels (P < 0.05). These effects proved to be reversible by a normal diet from 6 to 24 mo of age. However, at 24 mo, a long-term effect of the maternal gestational diet restriction (fetal...

  19. Exercise-induced alterations in pancreatic oxidative stress and mitochondrial function in type 2 diabetic Goto-Kakizaki rats.

    Science.gov (United States)

    Raza, Haider; John, Annie; Shafarin, Jasmin; Howarth, Frank C

    2016-04-01

    Progressive metabolic complications accompanied by oxidative stress are the hallmarks of type 2 diabetes. The precise molecular mechanisms of the disease complications, however, remain elusive. Exercise-induced nontherapeutic management of type 2 diabetes is the first line of choice to control hyperglycemia and diabetes associated complications. In this study, using 11-month-old type 2 Goto-Kakizaki (GK) rats, we have investigated the effects of exercise on mitochondrial metabolic and oxidative stress in the pancreas. Our results showed an increase in theNADPHoxidase enzyme activity and reactive oxygen species (ROS) production inGKrats, which was inhibited after exercise. Increased lipid peroxidation and protein carbonylation andSODactivity were also inhibited after exercise. Interestingly, glutathione (GSH) level was markedly high in the pancreas ofGKdiabetic rats even after exercise. However,GSH-peroxidase andGSH-reductase activities were significantly reduced. Exercise also induced energy metabolism as observed by increased hexokinase and glutamate dehydrogenase activities. A significant decrease in the activities of mitochondrial ComplexesII/IIIandIVwere observed in theGKrats. Exercise improved only ComplexIVactivity suggesting increased utilization of oxygen. We also observed increased activities of cytochrome P450s in the pancreas ofGKrats which was reduced significantly after exercise.SDS-PAGEresults have shown a decreased expression ofNF-κB, Glut-2, andPPAR-ϒ inGKrats which was markedly increased after exercise. These results suggest differential oxidative stress and antioxidant defense responses after exercise. Our results also suggest improved mitochondrial function and energy utilization in the pancreas of exercisingGKrats. PMID:27095835

  20. Calpastatin overexpression reduces oxidative stress-induced mitochondrial impairment and cell death in human neuroblastoma SH-SY5Y cells by decreasing calpain and calcineurin activation, induction of mitochondrial fission and destruction of mitochondrial fusion.

    Science.gov (United States)

    Tangmansakulchai, Kulvadee; Abubakar, Zuroida; Kitiyanant, Narisorn; Suwanjang, Wilasinee; Leepiyasakulchai, Chaniya; Govitrapong, Piyarat; Chetsawang, Banthit

    2016-09-01

    Calpain is an intracellular Ca(2+)-dependent protease, and the activation of calpain has been implicated in neurodegenerative diseases. Calpain activity can be regulated by calpastatin, an endogenous specific calpain inhibitor. Several lines of evidence have demonstrated a potential role of calpastatin in preventing calpain-mediated pathogenesis. Additionally, several studies have revealed that calpain activation and mitochondrial damage are involved in the cell death process; however, recent evidence has not clearly indicated a neuroprotective mechanism of calpastatin against calpain-dependent mitochondrial impairment in the process of neuronal cell death. Therefore, the purpose of this study was to investigate the potential ability of calpastatin to inhibit calpain activation and mitochondrial impairment in oxidative stress-induced neuron degeneration. Calpastatin was stably overexpressed in human neuroblastoma SH-SY5Y cells. In non-calpastatin overexpressing SH-SY5Y cells, hydrogen peroxide significantly decreased cell viability, superoxide dismutase activity, mitochondrial membrane potential, ATP production and mitochondrial fusion protein (Opa1) levels in the mitochondrial fraction but increased reactive oxygen species formation, calpain and calcineurin activation, mitochondrial fission protein (Fis1 and Drp1) levels in the mitochondrial fraction and apoptotic cells. Nevertheless, these toxic effects were abolished in hydrogen peroxide-treated calpastatin-overexpressing SH-SY5Y cells. The results of the present study demonstrate the potential ability of calpastatin to diminish calpain and calcineurin activation and mitochondrial impairment in neurons that are affected by oxidative damage. PMID:27453331

  1. Oxygen Glucose Deprivation in Rat Hippocampal Slice Cultures Results in Alterations in Carnitine Homeostasis and Mitochondrial Dysfunction

    OpenAIRE

    Thomas F. Rau; Qing Lu; Shruti Sharma; Xutong Sun; Gregory Leary; Beckman, Matthew L.; Yali Hou; Wainwright, Mark S; Michael Kavanaugh; Poulsen, David J.; Black, Stephen M.

    2012-01-01

    Mitochondrial dysfunction characterized by depolarization of mitochondrial membranes and the initiation of mitochondrial-mediated apoptosis are pathological responses to hypoxia-ischemia (HI) in the neonatal brain. Carnitine metabolism directly supports mitochondrial metabolism by shuttling long chain fatty acids across the inner mitochondrial membrane for beta-oxidation. Our previous studies have shown that HI disrupts carnitine homeostasis in neonatal rats and that L-carnitine can be neurop...

  2. Altered myoelectric activity in the experimental blind loop syndrome.

    OpenAIRE

    Justus, P G; Fernandez, A; Martin, J.L.; King, C E; Toskes, P P; Mathias, J R

    1983-01-01

    Nutrient malabsorption and diarrhea are characteristic of the blind loop syndrome. Alterations in motility have been implicated as a cause of bacterial overgrowth, but the possibility that altered motility may result from alterations in the flora has not been explored. The purpose of this study was to characterize the myoelectric activity of the small intestine in the blind loop rat model. Eight groups of rats were studied: rats with self-filling blind loops, which develop bacterial overgrowt...

  3. Electron transport chain inhibitors induce microglia activation through enhancing mitochondrial reactive oxygen species production.

    Science.gov (United States)

    Ye, Junli; Jiang, Zhongxin; Chen, Xuehong; Liu, Mengyang; Li, Jing; Liu, Na

    2016-01-15

    Reactive oxygen species (ROS) are believed to be mediators of excessive microglial activation, yet the resources and mechanism are not fully understood. Here we stimulated murine microglial BV-2 cells and primary microglial cells with different inhibitors of electron transport chain (ETC), rotenone, thenoyltrifluoroacetone (TTFA), antimycin A, and NaN3 to induce mitochondrial ROS production and we observed the role of mitochondrial ROS in microglial activation. Our results showed that ETC inhibitors resulted in significant changes in cell viability, microglial morphology, cell cycle arrest and mitochondrial ROS production in a dose-dependent manner in both primary cultural microglia and BV-2 cell lines. Moreover, ETC inhibitors, especially rotenone and antimycin A stimulated secretion of interleukin 1β (IL-1β), interleukin 6 (IL-6), interleukin 12 (IL-12) and tumor necrosis factor α (TNF-α) by microglia with marked activation of mitogen-activated proteinkinases (MAPKs) and nuclear factor κB (NF-κB), which could be blocked by specific inhibitors of MAPK and NF-κB and mitochondrial antioxidants, Mito-TEMPO. Taken together, our results demonstrated that inhibition of mitochondrial respiratory chain in microglia led to production of mitochondrial ROS and therefore may activate MAPK/NF-кB dependent inflammatory cytokines release in microglia, which indicated that mitochondrial-derived ROS were contributed to microglial activation. PMID:26511505

  4. Errantum: Treatment of human astrocytoma U87 cells with silicon dioxide nanoparticles lowers their survival and alters their expression of mitochondrial and cell signaling proteins

    Directory of Open Access Journals (Sweden)

    Lai JCK

    2010-12-01

    Full Text Available Lai JCK, Ananthakrishnan G, Jandhyam S, et al. Treatment of human astrocytoma U87 cells with silicon dioxide nanoparticles lowers their survival and alters their expression of mitochondrial and cell signaling proteins. Int J Nanomedicine. 2010;5:715–723.The wrong image was used in Figure 5 on page 719.

  5. Alterations in Glutathione Redox Metabolism, Oxidative Stress, and Mitochondrial Function in the Left Ventricle of Elderly Zucker Diabetic Fatty Rat Heart

    Directory of Open Access Journals (Sweden)

    Haider Raza

    2012-11-01

    Full Text Available The Zucker diabetic fatty (ZDF rat is a genetic model in which the homozygous (FA/FA male animals develop obesity and type 2 diabetes. Morbidity and mortality from cardiovascular complications, due to increased oxidative stress and inflammatory signals, are the hallmarks of type 2 diabetes. The precise molecular mechanism of contractile dysfunction and disease progression remains to be clarified. Therefore, we have investigated molecular and metabolic targets in male ZDF (30–34 weeks old rat heart compared to age matched Zucker lean (ZL controls. Hyperglycemia was confirmed by a 4-fold elevation in non-fasting blood glucose (478.43 ± 29.22 mg/dL in ZDF vs. 108.22 ± 2.52 mg/dL in ZL rats. An increase in reactive oxygen species production, lipid peroxidation and oxidative protein carbonylation was observed in ZDF rats. A significant increase in CYP4502E1 activity accompanied by increased protein expression was also observed in diabetic rat heart. Increased expression of other oxidative stress marker proteins, HO-1 and iNOS was also observed. GSH concentration and activities of GSH-dependent enzymes, glutathione S-transferase and GSH reductase, were, however, significantly increased in ZDF heart tissue suggesting a compensatory defense mechanism. The activities of mitochondrial respiratory enzymes, Complex I and Complex IV were significantly reduced in the heart ventricle of ZDF rats in comparison to ZL rats. Western blot analysis has also suggested a decreased expression of IκB-α and phosphorylated-JNK in diabetic heart tissue. Our results have suggested that mitochondrial dysfunction and increased oxidative stress in ZDF rats might be associated, at least in part, with altered NF-κB/JNK dependent redox cell signaling. These results might have implications in the elucidation of the mechanism of disease progression and designing strategies for diabetes prevention.

  6. Cardioprotective effects of mitochondrial KATP channels activated at different time

    Institute of Scientific and Technical Information of China (English)

    魏珂; 闵苏; 龙村

    2004-01-01

    Backgroud Recent studies in adult hearts have indicated that KATP channels in the inner mitochondrial membrance are responsible for the protection. And we investigated whether opening of mitochondrial KATP channels (mKATP) could provide myocardial protection for immature rabbits and determined its role in cardioprotection.Methods Thirty-four 3-4-week-old rabbits, weighing 300-350 g, were divided randomly into five groups: Group Ⅰ (control group, n=8); Group Ⅱ [diazoxide preconditioning group; n=8; the hearts were pretreated with 100 μmol/L diazoxide for 5 minutes followed by 10-minute wash out with Krebs-Henseleit buffer (KHB)]; Group Ⅲ [diazoxide+5-hydroxydeconate (5-HD) preconditioning group; n=5; the hearts were pretreated with 100 μmol/L diazoxide and 100 μmol/L 5-HD); Group Ⅳ (diazoxide+cardioplegia group; n=8; cardioplegia containing 100 μmol/L diazoxide perfused the hearts for 5 minutes before ischemia); Group Ⅴ (diazoxide+5-HD+cardioplegia group; n=5; the cardioplegia contained 100 μmol/L diazoxide and 100 μmol/L 5-HD). All hearts were excised and connected to langend ?Zrff perfusion system and passively perfused with KHB at 38℃ under a pressure of 70 cmH2O. After reperfusion, the recovery rate of left ventricular diastolic pressure (LVDP), ±dp/dtmax, coronary flow (CF), the creatinine kinase (CK), lactate dehydrogenase (LDH), aspartate aminotransferase (AST) in coronary sinus venous effluent and the tissue ATP were measured. Mitochondria were evaluated semiquantitatively by morphology.Results After ischemia and reperfusion (I/R), the two groups that were treated by diazoxide only (Groups Ⅱ and Ⅳ) had a significant improvement in LVDP, ±dp/dtmax, and CF recovery. AST, LDH, and CK were decreased, and the levels of tissue ATP in the two groups were higher. Mitochondria was protected better in Group Ⅳ than in other groups. Conclusions Activating mKATP channels before and during ischemia can similarly protect immature rabbit hearts

  7. Liver ultrastructural morphology and mitochondrial DNA levels in HIV/hepatitis C virus coinfection: no evidence of mitochondrial damage with highly active antiretroviral therapy.

    Science.gov (United States)

    Matsukura, Motoi; Chu, Fanny F S; Au, May; Lu, Helen; Chen, Jennifer; Rietkerk, Sonja; Barrios, Rolando; Farley, John D; Montaner, Julio S; Montessori, Valentina C; Walker, David C; Côté, Hélène C F

    2008-06-19

    Liver mitochondrial toxicity is a concern, particularly in HIV/hepatitis C virus (HCV) coinfection. Liver biopsies from HIV/HCV co-infected patients, 14 ON-highly active antiretroviral therapy (HAART) and nine OFF-HAART, were assessed by electron microscopy quantitative morphometric analyses. Hepatocytes tended to be larger ON-HAART than OFF-HAART (P = 0.05), but mitochondrial volume, cristae density, lipid volume, mitochondrial DNA and RNA levels were similar. We found no evidence of increased mitochondrial toxicity in individuals currently on HAART, suggesting that concomitant HAART should not delay HCV therapy. PMID:18525271

  8. Constitutive adipocyte mTORC1 activation enhances mitochondrial activity and reduces visceral adiposity in mice.

    Science.gov (United States)

    Magdalon, Juliana; Chimin, Patricia; Belchior, Thiago; Neves, Rodrigo X; Vieira-Lara, Marcel A; Andrade, Maynara L; Farias, Talita S; Bolsoni-Lopes, Andressa; Paschoal, Vivian A; Yamashita, Alex S; Kowaltowski, Alicia J; Festuccia, William T

    2016-05-01

    Mechanistic target of rapamycin complex 1 (mTORC1) loss of function reduces adiposity whereas partial mTORC1 inhibition enhances fat deposition. Herein we evaluated how constitutive mTORC1 activation in adipocytes modulates adiposity in vivo. Mice with constitutive mTORC1 activation in adipocytes induced by tuberous sclerosis complex (Tsc)1 deletion and littermate controls were evaluated for body mass, energy expenditure, glucose and fatty acid metabolism, mitochondrial function, mRNA and protein contents. Adipocyte-specific Tsc1 deletion reduced visceral, but not subcutaneous, fat mass, as well as adipocyte number and diameter, phenotypes that were associated with increased lipolysis, UCP-1 content (browning) and mRNA levels of pro-browning transcriptional factors C/EBPβ and ERRα. Adipocyte Tsc1 deletion enhanced mitochondrial oxidative activity, fatty acid oxidation and the expression of PGC-1α and PPARα in both visceral and subcutaneous fat. In brown adipocytes, however, Tsc1 deletion did not affect UCP-1 content and basal respiration. Adipocyte Tsc1 deletion also reduced visceral adiposity and enhanced glucose tolerance, liver and muscle insulin signaling and adiponectin secretion in mice fed with purified low- or high-fat diet. In conclusion, adipocyte-specific Tsc1 deletion enhances mitochondrial activity, induces browning and reduces visceral adiposity in mice. PMID:26923434

  9. Transcranial laser therapy alters amyloid precursor protein processing and improves mitochondrial function in a mouse model of Alzheimer's disease

    Science.gov (United States)

    McCarthy, Thomas; Yu, Jin; El-Amouri, Salim; Gattoni-Celli, Sebastiano; Richieri, Steve; De Taboada, Luis; Streeter, Jackson; Kindy, Mark S.

    2011-03-01

    Transcranial laser therapy (TLT) using a near-infrared energy laser system was tested in the 2x Tg amyloid precursor protein (APP) mouse model of Alzheimer's Disease (AD). TLT was administered 3 times/week at escalating doses, starting at 3 months of age, and was compared to a control group which received no laser treatment. Treatment sessions were continued for a total of six months. The brains were examined for amyloid plaque burden, Aβ peptides (Aβ1-40 and Aβ1-42 ), APP cleavage products (sAPPα, CTFβ) and mitochondrial activity. Administration of TLT was associated with a significant, dose-dependent reduction in amyloid load as indicated by the numbers of Aβ plaques. Levels of Aβ1-40 and Aβ1-42 levels were likewise reduced in a dose-dependent fashion. All TLT doses produced an increase in brain sAPPα and a decrease in CTFβ levels consistent with an increase in α-secretase activity and a decrease in β-secretase activity. In addition, TLT increased ATP levels and oxygen utilization in treated animals suggesting improved mitochondrial function. These studies suggest that TLT is a potential candidate for treatment of AD.

  10. Leber Hereditary Optic Neuropathy: Do Folate Pathway Gene Alterations Influence the Expression of Mitochondrial DNA Mutation?

    Directory of Open Access Journals (Sweden)

    A Aleyasin

    2010-09-01

    Full Text Available "nBackground: Leber hereditary optic neuropathy (LHON is an inherited form of bilateral optic atrophy leading to the loss of central vision.  The primary cause of vision loss is mutation in the mitochondrial DNA (mtDNA, however, unknown secon­dary genetic and/or epigenetic risk factors are suggested to influence its neuropathology.  In this study folate gene polymor­phisms were examined as a possible LHON secondary genetic risk factor in Iranian patients."nMethods: Common polymorphisms in the MTHFR (C677T and A1298C and MTRR (A66G genes were tested in 21 LHON patients and 150 normal controls."nResults:  Strong associations were observed between the LHON syndrome and C677T (P= 0.00 and A66G (P= 0.00 polymor­phisms.  However, no significant association was found between A1298C (P =0.69 and the LHON syndrome."nConclusion: This is the first study that shows MTHFR C677T and MTRR A66G polymorphisms play a role in the etiology of the LHON syndrome.  This finding may help in the better understanding of mechanisms involved in neural degeneration and vision loss by LHON and hence the better treatment of patients.

  11. Mitochondrial Biogenesis and Peroxisome Proliferator–Activated Receptor-γ Coactivator-1α (PGC-1α) Deacetylation by Physical Activity

    OpenAIRE

    Li, Ling; Pan, Ruping; Li, Rong; Niemann, Bernd; Aurich, Anne-Cathleen; Chen, Ying; Rohrbach, Susanne

    2010-01-01

    OBJECTIVE Transcriptional peroxisome proliferator–activated receptor-γ coactivator-1α (PGC-1α) plays a key role in mitochondrial biogenesis and energy metabolism and is suggested to be involved in the exercise-induced increase in mitochondrial content. PGC-1α activity is regulated by posttranslational modifications, among them acetylation or phosphorylation. Accordingly, the deacetylase SIRT1 and the kinase AMPK increase PGC-1α activity. RESEARCH DESIGN AND METHODS We tested whether chronic t...

  12. Syringaresinol induces mitochondrial biogenesis through activation of PPARβ pathway in skeletal muscle cells.

    Science.gov (United States)

    Thach, Trung Thanh; Lee, Chan-Kyu; Park, Hyun Woo; Lee, Sang-Jun; Lee, Sung-Joon

    2016-08-15

    Activation of peroxisome proliferator-activated receptors (PPARs) plays a crucial role in cellular energy metabolism that directly impacts mitochondrial biogenesis. In this study, we demonstrate that syringaresinol, a pharmacological lignan extracted from Panax ginseng berry, moderately binds to and activates PPARβ with KD and EC50 values of 27.62±15.76μM and 18.11±4.77μM, respectively. Subsequently, the expression of peroxisome proliferator-activated receptor γ coactivator-1α together with PPARβ transcriptional targets, mitochondrial carnitine palmitoyltransferase 1 and uncoupling protein 2, was also enhanced in terms of both mRNA and protein levels. The activation of these proteins induced mitochondrial biogenesis by enrichment of mitochondrial replication and density within C2C12 myotubes. Importantly, knockdown of PPARβ reduced the syringaresinol-induced protein expression followed by the significant reduction of mitochondrial biogenesis. Taken together, our results indicate that syringaresinol induces mitochondrial biogenesis by activating PPARβ pathway. PMID:27450788

  13. Does mental exertion alter maximal muscle activation?

    OpenAIRE

    Vianney Rozand; Benjamin Pageaux

    2014-01-01

    Mental exertion is known to impair endurance performance, but its effects on neuromuscular function remain unclear. The purpose of this study was to test the hypothesis that mental exertion reduces torque and muscle activation during intermittent maximal voluntary contractions of the knee extensors. Ten subjects performed in a randomized order three separate mental exertion conditions lasting 27 minutes each: i) high mental exertion (incongruent Stroop task), ii) moderate mental exertion (con...

  14. Does mental exertion alter maximal muscle activation?

    OpenAIRE

    Rozand, Vianney; Pageaux, Benjamin; Marcora, Samuele M.; Papaxanthis, Charalambos; Lepers, Romuald

    2014-01-01

    Mental exertion is known to impair endurance performance, but its effects on neuromuscular function remain unclear. The purpose of this study was to test the hypothesis that mental exertion reduces torque and muscle activation during intermittent maximal voluntary contractions of the knee extensors. Ten subjects performed in a randomized order three separate mental exertion conditions lasting 27 min each: (i) high mental exertion (incongruent Stroop task), (ii) moderate mental exertion (congr...

  15. Mitochondrial Dysfunction, Disruption of F-Actin Polymerization, and Transcriptomic Alterations in Zebrafish Larvae Exposed to Trichloroethylene.

    Science.gov (United States)

    Wirbisky, Sara E; Damayanti, Nur P; Mahapatra, Cecon T; Sepúlveda, Maria S; Irudayaraj, Joseph; Freeman, Jennifer L

    2016-02-15

    Trichloroethylene (TCE) is primarily used as an industrial degreasing agent and has been in use since the 1940s. TCE is released into the soil, surface, and groundwater. From an environmental and regulatory standpoint, more than half of Superfund hazardous waste sites on the National Priority List are contaminated with TCE. Occupational exposure to TCE occurs primarily via inhalation, while environmental TCE exposure also occurs through ingestion of contaminated drinking water. Current literature links TCE exposure to various adverse health effects including cardiovascular toxicity. Current studies aiming to address developmental cardiovascular toxicity utilized rodent and avian models, with the majority of studies using relatively higher parts per million (mg/L) doses. In this study, to further investigate developmental cardiotoxicity of TCE, zebrafish embryos were treated with 0, 10, 100, or 500 parts per billion (ppb; μg/L) TCE during embryogenesis and/or through early larval stages. After the appropriate exposure period, angiogenesis, F-actin, and mitochondrial function were assessed. A significant dose-response decrease in angiogenesis, F-actin, and mitochondrial function was observed. To further complement this data, a transcriptomic profile of zebrafish larvae was completed to identify gene alterations associated with the 10 ppb TCE exposure. Results from the transcriptomic data revealed that embryonic TCE exposure caused significant changes in genes associated with cardiovascular disease, cancer, and organismal injury and abnormalities with a number of targets in the FAK signaling pathway. Overall, results from our study support TCE as a developmental cardiovascular toxicant, provide molecular targets and pathways for investigation in future studies, and indicate a need for continued priority for environmental regulation. PMID:26745549

  16. Ionizing radiation induces PI3K-dependent JNK activation for amplifying mitochondrial dysfunction in human cervical cancer cells

    International Nuclear Information System (INIS)

    Ionizing radiation is one of the most commonly used treatments for a wide variety of tumors. Exposure of cells to ionizing radiation results in the simultaneous activation or down regulation of multiple signaling pathways, which play critical role in controlling cell death and cell survival after irradiation in a cell type specific manner. The molecular mechanism by which apoptotic cell death occurs in response to ionizing radiation has been widely explored but not precisely deciphered. Therefore an improved understanding of the mechanisms involved in radiation-induced apoptosis may ultimately provide novel strategies of intervention in specific signal transduction pathways to favorably alter the therapeutic ratio in the treatment of human malignancies. The aim of our investigation was to elucidate molecular mechanisms of the mitochondrial dysfunction mediated apoptotic cell death triggered by ionizing radiation in human cervical cancer cells. We demonstrated that ionizing radiation utilizes PI3K-JNK signaling pathway for amplifying mitochondrial dysfunction and susequent apoptotic cell death: We showed that PI3K-dependent JNK activation leads to transcriptional upregulation of Fas and the phosphorylation/inactivation of Bcl-2, resulting in mitochondrial dysfunction-mediated apoptotic cell death in response to ionizing radiation

  17. Mitochondrial Alterations by PARKIN in Dopaminergic Neurons Using PARK2 Patient-Specific and PARK2 Knockout Isogenic iPSC Lines

    Directory of Open Access Journals (Sweden)

    Atossa Shaltouki

    2015-05-01

    Full Text Available In this study, we used patient-specific and isogenic PARK2-induced pluripotent stem cells (iPSCs to show that mutations in PARK2 alter neuronal proliferation. The percentage of TH+ neurons was decreased in Parkinson’s disease (PD patient-derived neurons carrying various mutations in PARK2 compared with an age-matched control subject. This reduction was accompanied by alterations in mitochondrial:cell volume fraction (mitochondrial volume fraction. The same phenotype was confirmed in isogenic PARK2 null lines. The mitochondrial phenotype was also seen in non-midbrain neurons differentiated from the PARK2 null line, as was the functional phenotype of reduced proliferation in culture. Whole genome expression profiling at various stages of differentiation confirmed the mitochondrial phenotype and identified pathways altered by PARK2 dysfunction that include PD-related genes. Our results are consistent with current model of PARK2 function where damaged mitochondria are targeted for degradation via a PARK2/PINK1-mediated mechanism.

  18. Significance of somatic mutations and content alteration of mitochondrial DNA in esophageal cancer

    International Nuclear Information System (INIS)

    The roles of mitochondria in energy metabolism, the generation of ROS, aging, and the initiation of apoptosis have implicated their importance in tumorigenesis. In this study we aim to establish the mutation spectrum and to understand the role of somatic mtDNA mutations in esophageal cancer. The entire mitochondrial genome was screened for somatic mutations in 20 pairs (18 esophageal squamous cell carcinomas, one adenosquamous carcinoma and one adenocarcinoma) of tumor/surrounding normal tissue of esophageal cancers, using temporal temperature gradient gel electrophoresis (TTGE), followed by direct DNA sequencing to identify the mutations. Fourteen somatic mtDNA mutations were identified in 55% (11/20) of tumors analyzed, including 2 novel missense mutations and a frameshift mutation in ND4L, ATP6 subunit, and ND4 genes respectively. Nine mutations (64%) were in the D-loop region. Numerous germline variations were found, at least 10 of them were novel and five were missense mutations, some of them occurred in evolutionarily conserved domains. Using real-time quantitative PCR analysis, the mtDNA content was found to increase in some tumors and decrease in others. Analysis of molecular and other clinicopathological findings does not reveal significant correlation between somatic mtDNA mutations and mtDNA content, or between mtDNA content and metastatic status. Our results demonstrate that somatic mtDNA mutations in esophageal cancers are frequent. Some missense and frameshift mutations may play an important role in the tumorigenesis of esophageal carcinoma. More extensive biochemical and molecular studies will be necessary to determine the pathological significance of these somatic mutations

  19. Significance of somatic mutations and content alteration of mitochondrial DNA in esophageal cancer

    Directory of Open Access Journals (Sweden)

    Wang Yu-Fen

    2006-04-01

    Full Text Available Abstract Background The roles of mitochondria in energy metabolism, the generation of ROS, aging, and the initiation of apoptosis have implicated their importance in tumorigenesis. In this study we aim to establish the mutation spectrum and to understand the role of somatic mtDNA mutations in esophageal cancer. Methods The entire mitochondrial genome was screened for somatic mutations in 20 pairs (18 esophageal squamous cell carcinomas, one adenosquamous carcinoma and one adenocarcinoma of tumor/surrounding normal tissue of esophageal cancers, using temporal temperature gradient gel electrophoresis (TTGE, followed by direct DNA sequencing to identify the mutations. Results Fourteen somatic mtDNA mutations were identified in 55% (11/20 of tumors analyzed, including 2 novel missense mutations and a frameshift mutation in ND4L, ATP6 subunit, and ND4 genes respectively. Nine mutations (64% were in the D-loop region. Numerous germline variations were found, at least 10 of them were novel and five were missense mutations, some of them occurred in evolutionarily conserved domains. Using real-time quantitative PCR analysis, the mtDNA content was found to increase in some tumors and decrease in others. Analysis of molecular and other clinicopathological findings does not reveal significant correlation between somatic mtDNA mutations and mtDNA content, or between mtDNA content and metastatic status. Conclusion Our results demonstrate that somatic mtDNA mutations in esophageal cancers are frequent. Some missense and frameshift mutations may play an important role in the tumorigenesis of esophageal carcinoma. More extensive biochemical and molecular studies will be necessary to determine the pathological significance of these somatic mutations.

  20. Alteration in expression of the rat mitochondrial ATPase 6 gene during Pneumocystis carinii infection

    Directory of Open Access Journals (Sweden)

    Bartlett Marilyn S

    2001-06-01

    Full Text Available Abstract Background Pneumocystis carinii causes pneumonia in immunocompromised patients with a high morbidity and mortality rate, but the interaction between this organism and the host cell is not well understood. The purpose of this research was to study the response of host cells to P. carinii infection on a molecular level. Results The technique of mRNA differential display was used to detect genes whose expression may be affected by P. carinii infection. The nucleotide sequence of one differentially displayed DNA fragment was found to be identical to that of the rat mitochondrial ATPase 6 gene, which is a subunit of the F0F1-ATP synthase complex. A four-fold increase in expression of this gene was verified by Northern blot analysis of total RNA extracted from P. carinii-infected rat lung versus that from mock-infected rat lung. Localization of the cells containing ATPase 6 mRNA was accomplished by in situ hybridization. In sections of non-infected rat lung, these cells were found lining the distal parts of the respiratory tree and in apical areas of the alveoli. Histological location of these cells suggested that they were Clara cells and type II pneumocytes. This hypothesis was confirmed by co-localizing the mRNAs for ATPase 6 and surfactant protein B (SP-B to the same cells by two-color fluorescent in situ hybridization. Conclusions The ATPase 6 gene is over expressed during P. carinii infection, and type II pneumocytes and Clara cells are the cell types responsible for this over-expression.

  1. Hypobaric Hypoxia Imbalances Mitochondrial Dynamics in Rat Brain Hippocampus

    Directory of Open Access Journals (Sweden)

    Khushbu Jain

    2015-01-01

    Full Text Available Brain is predominantly susceptible to oxidative stress and mitochondrial dysfunction during hypobaric hypoxia, and therefore undergoes neurodegeneration due to energy crisis. Evidences illustrate a high degree of association for mitochondrial fusion/fission imbalance and mitochondrial dysfunction. Mitochondrial fusion/fission is a recently reported dynamic mechanism which frequently occurs among cellular mitochondrial network. Hence, the study investigated the temporal alteration and involvement of abnormal mitochondrial dynamics (fusion/fission along with disturbed mitochondrial functionality during chronic exposure to hypobaric hypoxia (HH. The Sprague-Dawley rats were exposed to simulated high altitude equivalent to 25000 ft for 3, 7, 14, 21, and 28 days. Mitochondrial morphology, distribution within neurons, enzyme activity of respiratory complexes, Δψm, ADP: ATP, and expression of fission/fusion key proteins were determined. Results demonstrated HH induced alteration in mitochondrial morphology by damaged, small mitochondria observed in neurons with disturbance of mitochondrial functionality and reduced mitochondrial density in neuronal processes manifested by excessive mitochondrial fragmentation (fission and decreased mitochondrial fusion as compared to unexposed rat brain hippocampus. The study suggested that imbalance in mitochondrial dynamics is one of the noteworthy mechanisms occurring in hippocampal neurons during HH insult.

  2. Rapamycin attenuates mitochondrial dysfunction via activation of mitophagy in experimental ischemic stroke

    Energy Technology Data Exchange (ETDEWEB)

    Li, Qiang [Department of Neurology, Shanghai Sixth People’s Hospital, Shanghai Jiao Tong University, Shanghai 200233 (China); Department of Neurology, Shanghai Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011 (China); Zhang, Ting [Department of Neurology, Shanghai Sixth People’s Hospital, Shanghai Jiao Tong University, Shanghai 200233 (China); Wang, Jixian [Department of Neurology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025 (China); Med-X Research Institute and School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200030 (China); Zhang, Zhijun [Med-X Research Institute and School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200030 (China); Zhai, Yu [Department of Neurology, Shanghai Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011 (China); Yang, Guo-Yuan, E-mail: gyyang0626@gmail.com [Department of Neurology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025 (China); Med-X Research Institute and School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200030 (China); Sun, Xiaojiang, E-mail: sunxj19@gmail.com [Department of Neurology, Shanghai Sixth People’s Hospital, Shanghai Jiao Tong University, Shanghai 200233 (China)

    2014-02-07

    Highlights: • Rapamycin enhances mitophagy via increasing p62 translocation to the mitochondria. • Rapamycin attenuates brain ischemic damage and improves mitochondrial function. • The protection of rapamycin to mitochondrial is linked to enhanced mitophagy. - Abstract: Rapamycin has been demonstrated to exhibit neuroprotective functions via the activation of autophagy in a cerebral ischemia model. However, the involvement of mitophagy in this process and its contribution to the protection of mitochondrial function remains unknown. The present study explored the characteristics of mitophagy after cerebral ischemia and the effect of rapamycin on mitochondrial function. Male Sprague–Dawley rats underwent transient middle cerebral artery occlusion (tMCAO). Neurological deficits scores; infarct volumes; mitophagy morphology; and the levels of malondialdehyde (MDA), adenosine triphosphate (ATP) and mitochondrial membrane potentials (Δψm) were examined. The expression of LC3, Beclin-1 and p62 in the mitochondrial fraction combined with transmission electronic microscopy were used to explore mitophagic activity after ischemia. We also blocked autophagosome formation using 3-methyladenine (3-MA) to check the linkage between the mitochondrial protective effect of rapamycin and enhanced mitophagy. We observed that rapamycin significantly enhanced mitophagy, as evidenced by the increase in LC3-II and Beclin-1 expression in the mitochondria and p62 translocation to the mitochondria. Rapamycin reduced infarct volume, improved neurological outcomes and inhibited mitochondrial dysfunction compared with the control animals (p < 0.05). However, these protective effects were reversed by 3-methyladenine treatment after rapamycin. The present study indicates that rapamycin treatment attenuates mitochondrial dysfunction following cerebral ischemia, which is linked to enhanced mitophagy.

  3. Rapamycin attenuates mitochondrial dysfunction via activation of mitophagy in experimental ischemic stroke

    International Nuclear Information System (INIS)

    Highlights: • Rapamycin enhances mitophagy via increasing p62 translocation to the mitochondria. • Rapamycin attenuates brain ischemic damage and improves mitochondrial function. • The protection of rapamycin to mitochondrial is linked to enhanced mitophagy. - Abstract: Rapamycin has been demonstrated to exhibit neuroprotective functions via the activation of autophagy in a cerebral ischemia model. However, the involvement of mitophagy in this process and its contribution to the protection of mitochondrial function remains unknown. The present study explored the characteristics of mitophagy after cerebral ischemia and the effect of rapamycin on mitochondrial function. Male Sprague–Dawley rats underwent transient middle cerebral artery occlusion (tMCAO). Neurological deficits scores; infarct volumes; mitophagy morphology; and the levels of malondialdehyde (MDA), adenosine triphosphate (ATP) and mitochondrial membrane potentials (Δψm) were examined. The expression of LC3, Beclin-1 and p62 in the mitochondrial fraction combined with transmission electronic microscopy were used to explore mitophagic activity after ischemia. We also blocked autophagosome formation using 3-methyladenine (3-MA) to check the linkage between the mitochondrial protective effect of rapamycin and enhanced mitophagy. We observed that rapamycin significantly enhanced mitophagy, as evidenced by the increase in LC3-II and Beclin-1 expression in the mitochondria and p62 translocation to the mitochondria. Rapamycin reduced infarct volume, improved neurological outcomes and inhibited mitochondrial dysfunction compared with the control animals (p < 0.05). However, these protective effects were reversed by 3-methyladenine treatment after rapamycin. The present study indicates that rapamycin treatment attenuates mitochondrial dysfunction following cerebral ischemia, which is linked to enhanced mitophagy

  4. 4E-BP extends lifespan upon dietary restriction by enhancing mitochondrial activity in Drosophila

    OpenAIRE

    Zid, Brian M.; Rogers, Aric; Katewa, Subhash D.; Vargas, Miguel A.; Kolipinski, Marysia; Lu, Tony Au; Benzer, Seymour; Kapahi, Pankaj

    2009-01-01

    Dietary restriction (DR) extends lifespan in multiple species. To examine the mechanisms of lifespan extension upon DR, we assayed genome-wide translational changes in Drosophila. A number of nuclear encoded mitochondrial genes, including those in Complex I and IV of the electron transport chain, showed increased ribosomal loading and enhanced overall activity upon DR. We found that various mitochondrial genes possessed shorter and less structured 5′UTRs, which were important for their enhanc...

  5. Mitochondrial Protection and Anti-aging Activity of Astragalus Polysaccharides and Their Potential Mechanism

    OpenAIRE

    Xiao-Juan Xin; Ze Liu; Ming-Bo Gao; Feng-Xin Jin; De-Wen Liu; Ya-Kui Zhang; Hai-Xue Kuang; Xing-Tai Li

    2012-01-01

    The current study was performed to investigate mitochondrial protection and anti-aging activity of Astragalus polysaccharides (APS) and the potential underlying mechanism. Lipid peroxidation of liver and brain mitochondria was induced by Fe2+–Vit C in vitro. Thiobarbituric acid (TBA) colorimetry was used to measure the content of thiobarbituric acid reactive substances (TBARS). Mouse liver mitochondrial permeability transition (PT) was induced by calcium overload in vitro and spectrophotometr...

  6. Early ERK1/2 activation promotes DRP1-dependent mitochondrial fission necessary for cell reprogramming.

    Science.gov (United States)

    Prieto, Javier; León, Marian; Ponsoda, Xavier; Sendra, Ramón; Bort, Roque; Ferrer-Lorente, Raquel; Raya, Angel; López-García, Carlos; Torres, Josema

    2016-01-01

    During the process of reprogramming to induced pluripotent stem (iPS) cells, somatic cells switch from oxidative to glycolytic metabolism, a transition associated with profound mitochondrial reorganization. Neither the importance of mitochondrial remodelling for cell reprogramming, nor the molecular mechanisms controlling this process are well understood. Here, we show that an early wave of mitochondrial fragmentation occurs upon expression of reprogramming factors. Reprogramming-induced mitochondrial fission is associated with a minor decrease in mitochondrial mass but not with mitophagy. The pro-fission factor Drp1 is phosphorylated early in reprogramming, and its knockdown and inhibition impairs both mitochondrial fragmentation and generation of iPS cell colonies. Drp1 phosphorylation depends on Erk activation in early reprogramming, which occurs, at least in part, due to downregulation of the MAP kinase phosphatase Dusp6. Taken together, our data indicate that mitochondrial fission controlled by an Erk-Drp1 axis constitutes an early and necessary step in the reprogramming process to pluripotency. PMID:27030341

  7. Mitochondrial impairment by PPAR agonists and statins identified via immunocaptured OXPHOS complex activities and respiration

    International Nuclear Information System (INIS)

    Mitochondrial impairment is increasingly implicated in the etiology of toxicity caused by some thiazolidinediones, fibrates, and statins. We examined the effects of members of these drug classes on respiration of isolated rat liver mitochondria using a phosphorescent oxygen sensitive probe and on the activity of individual oxidative phosphorylation (OXPHOS) complexes using a recently developed immunocapture technique. Of the six thiazolidinediones examined, ciglitazone, troglitazone, and darglitazone potently disrupted mitochondrial respiration. In accord with these data, ciglitazone and troglitazone were also potent inhibitors of Complexes II + III, IV, and V, while darglitazone predominantly inhibited Complex IV. Of the six statins evaluated, lovastatin, simvastatin, and cerivastatin impaired mitochondrial respiration the most, with simvastatin and lovastatin impairing multiple OXPHOS Complexes. Within the class of fibrates, gemfibrozil more potently impaired respiration than fenofibrate, clofibrate, or ciprofibrate. Gemfibrozil only modestly inhibited Complex I, fenofibrate inhibited Complexes I, II + III, and V, and clofibrate inhibited Complex V. Our findings with the two complementary methods indicate that (1) some members of each class impair mitochondrial respiration, whereas others have little or no effect, and (2) the rank order of mitochondrial impairment accords with clinical adverse events observed with these drugs. Since the statins are frequently co-prescribed with the fibrates or thiazolidinediones, various combinations of these three drug classes were also analyzed for their mitochondrial effects. In several cases, the combination additively uncoupled or inhibited respiration, suggesting that some combinations are more likely to yield clinically relevant drug-induced mitochondrial side effects than others

  8. Mitochondrial DNA mutation-elicited oxidative stress, oxidative damage, and altered gene expression in cultured cells of patients with MERRF syndrome.

    Science.gov (United States)

    Wu, Shi-Bei; Ma, Yi-Shing; Wu, Yu-Ting; Chen, Yin-Chiu; Wei, Yau-Huei

    2010-06-01

    Myoclonic epilepsy and ragged-red fibers (MERRF) syndrome is a rare disorder characterized by myoclonus, muscle weakness, cerebellar ataxia, heart conduction block, and dementia. It has been documented that 80-90% of the patients with MERRF syndrome are caused by the A8344G mutation in the tRNA(Lys) gene of mitochondrial DNA (mtDNA). We and other investigators have reported that the mtDNA mutation results in not only inefficient generation of adenosine triphosphate but also increased production of reactive oxygen species (ROS) in cultured cells harboring A8344G mutation of mtDNA. In addition, we found an imbalance in the gene expression of antioxidant enzymes in the skin fibroblasts of MERRF patients. The mRNA, protein, and enzyme activity levels of manganese-superoxide dismutase were increased, but those of Cu,Zn-SOD, catalase, and glutathione peroxidase did not show significant changes. Recently, we showed that the excess ROS could damage voltage-dependent anion channel, prohibitin, Lon protease, and aconitase in the MERRF cells. Moreover, there was a dramatic increase in the gene expression and activity of matrix metalloproteinase 1, which may contribute to the cytoskeleton remodeling involved in the weakness and atrophy of muscle commonly seen in MERRF patients. Taken together, we suggest that mtDNA mutation-elicited oxidative stress, oxidative damage, and altered gene expression are involved in the pathogenesis and progression of MERRF syndrome. PMID:20411357

  9. Ginsenoside Rg1 Attenuates Isoflurane-induced Caspase-3 Activation via Inhibiting Mitochondrial Dysfunction

    Institute of Scientific and Technical Information of China (English)

    MIAO Hui Hui; ZHEN Yu; DING Guan Nan; HONG Fang Xiao; XIE Zhong Cong; TIAN Ming

    2015-01-01

    Objective The inhalation anesthetic isoflurane has been shown to induce mitochondrial dysfunction and caspase activation, which may lead to learning and memory impairment. Ginsenoside Rg1 is reported to be neuroprotective. We therefore set out to determine whether ginsenoside Rg1 can attenuate isoflurane-induced caspase activation via inhibiting mitochondrial dysfunction. Methods We investigated the effects of ginsenoside Rg1 at concentrations of 12.5, 25, and 50 µmol/L and pretreatment times of 12 h and 24 h on isoflurane-induced caspase-3 activation in H4 naïve and stably transfected H4 human neuroglioma cells that express full-length human amyloid precursor protein (APP) (H4-APP cells). For mitochondrial dysfunction, we assessed mitochondrial permeability transition pore (mPTP) and adenosine-5’-triphosphate (ATP) levels. We employed Western blot analysis, chemiluminescence, and flowcytometry. Results Here we show that pretreatment with 50 µmol/L ginsenoside Rg1 for 12 h attenuated isoflurane-induced caspase-3 activation and mitochondrial dysfunction in H4-APP cells, while pretreatment with 25 and 50 µmol/L ginsenoside Rg1 for 24 h attenuated isoflurane-induced caspase-3 activation and mitochondrial dysfunction in both H4 naïve and H4-APP cells. Conclusion These data suggest that ginsenoside Rg1 may ameliorate isoflurane-induced caspase-3 activation by inhibiting mitochondrial dysfunction. Pending further studies, these findings might recommend the use of ginsenoside Rg1 in preventing and treating isoflurane-induced neurotoxicity.

  10. Activation of AMPKα2 Is Not Required for Mitochondrial FAT/CD36 Accumulation during Exercise.

    Directory of Open Access Journals (Sweden)

    Cynthia Monaco

    Full Text Available Exercise has been shown to induce the translocation of fatty acid translocase (FAT/CD36, a fatty acid transport protein, to both plasma and mitochondrial membranes. While previous studies have examined signals involved in the induction of FAT/CD36 translocation to sarcolemmal membranes, to date the signaling events responsible for FAT/CD36 accumulation on mitochondrial membranes have not been investigated. In the current study muscle contraction rapidly increased FAT/CD36 on plasma membranes (7.5 minutes, while in contrast, FAT/CD36 only increased on mitochondrial membranes after 22.5 minutes of muscle contraction, a response that was exercise-intensity dependent. Considering that previous research has shown that AMP activated protein kinase (AMPK α2 is not required for FAT/CD36 translocation to the plasma membrane, we investigated whether AMPK α2 signaling is necessary for mitochondrial FAT/CD36 accumulation. Administration of 5-Aminoimidazole-4-carboxamide ribonucleotide (AICAR induced AMPK phosphorylation, and resulted in FAT/CD36 accumulation on SS mitochondria, suggesting AMPK signaling may mediate this response. However, SS mitochondrial FAT/CD36 increased following acute treadmill running in both wild-type (WT and AMPKα 2 kinase dead (KD mice. These data suggest that AMPK signaling is not required for SS mitochondrial FAT/CD36 accumulation. The current data also implicates alternative signaling pathways that are exercise-intensity dependent, as IMF mitochondrial FAT/CD36 content only occurred at a higher power output. Taken altogether the current data suggests that activation of AMPK signaling is sufficient but not required for exercise-induced accumulation in mitochondrial FAT/CD36.

  11. Acyl-CoA synthetase 1 deficiency alters cardiolipin species and impairs mitochondrial function

    DEFF Research Database (Denmark)

    Grevengoed, Trisha J; Martin, Sarah A; Katunga, Lalage; Cooper, Daniel E; Anderson, Ethan J; Murphy, Robert C; Coleman, Rosalind A

    2015-01-01

    Long-chain acyl-CoA synthetase 1 (ACSL1) contributes more than 90% of total cardiac ACSL activity, but its role in phospholipid synthesis has not been determined. Mice with an inducible knockout of ACSL1 (Acsl1(T-/-)) have impaired cardiac fatty acid oxidation and rely on glucose for ATP producti...

  12. Activation of mitochondrial calpain and increased cardiac injury: beyond AIF release.

    Science.gov (United States)

    Thompson, Jeremy; Hu, Ying; Lesnefsky, Edward J; Chen, Qun

    2016-02-01

    Calpain 1 (CPN1) is a ubiquitous cysteine protease that exists in both cytosol and cardiac mitochondria. Mitochondrial CPN1 (mit-CPN1) is located in the intermembrane space and matrix. Activation of mit-CPN1 within the intermembrane space increases cardiac injury by releasing apoptosis-inducing factor from mitochondria during ischemia-reperfusion (IR). We asked if activation of mit-CPN1 is involved in mitochondrial injury during IR. MDL-28170 (MDL) was used to inhibit CPN1 in buffer-perfused hearts following 25-min ischemia and 30-min reperfusion. MDL treatment decreased the release of lactate dehydrogenase into coronary effluent compared with untreated hearts, indicating that inhibition of CPN1 decreases cardiac injury. MDL also prevented the cleavage of spectrin (a substrate of CPN1) in cytosol during IR, supporting that MDL treatment decreased cytosolic calpain activation. In addition, MDL markedly improved calcium retention capacity compared with untreated heart, suggesting that MDL treatment decreases mitochondrial permeability transition pore opening. In addition, we found that IR led to decreased complex I activity, whereas inhibition of mit-CPN1 using MDL protected complex I. Pyruvate dehydrogenase content was decreased following IR. However, pyruvate dehydrogenase content was preserved in MDL-treated mitochondria. Taken together, MDL treatment decreased cardiac injury during IR by inhibiting both cytosolic and mit-CPN1. Activation of mit-CPN1 increases cardiac injury during IR by sensitizing mitochondrial permeability transition pore opening and impairing mitochondrial metabolism through damage of complex I. PMID:26637561

  13. Effect of mitochondrial complex I inhibition on Fe-S cluster protein activity

    International Nuclear Information System (INIS)

    Highlights: → Mitochondrial complex I inhibition resulted in decreased activity of Fe-S containing enzymes mitochondrial aconitase and cytoplasmic aconitase and xanthine oxidase. → Complex I inhibition resulted in the loss of Fe-S clusters in cytoplasmic aconitase and of glutamine phosphoribosyl pyrophosphate amidotransferase. → Consistent with loss of cytoplasmic aconitase activity, an increase in iron regulatory protein 1 activity was found. → Complex I inhibition resulted in an increase in the labile cytoplasmic iron pool. -- Abstract: Iron-sulfur (Fe-S) clusters are small inorganic cofactors formed by tetrahedral coordination of iron atoms with sulfur groups. Present in numerous proteins, these clusters are involved in key biological processes such as electron transfer, metabolic and regulatory processes, DNA synthesis and repair and protein structure stabilization. Fe-S clusters are synthesized mainly in the mitochondrion, where they are directly incorporated into mitochondrial Fe-S cluster-containing proteins or exported for cytoplasmic and nuclear cluster-protein assembly. In this study, we tested the hypothesis that inhibition of mitochondrial complex I by rotenone decreases Fe-S cluster synthesis and cluster content and activity of Fe-S cluster-containing enzymes. Inhibition of complex I resulted in decreased activity of three Fe-S cluster-containing enzymes: mitochondrial and cytosolic aconitases and xanthine oxidase. In addition, the Fe-S cluster content of glutamine phosphoribosyl pyrophosphate amidotransferase and mitochondrial aconitase was dramatically decreased. The reduction in cytosolic aconitase activity was associated with an increase in iron regulatory protein (IRP) mRNA binding activity and with an increase in the cytoplasmic labile iron pool. Since IRP activity post-transcriptionally regulates the expression of iron import proteins, Fe-S cluster inhibition may result in a false iron deficiency signal. Given that inhibition of complex

  14. Myelin alters the inflammatory phenotype of macrophages by activating PPARs

    OpenAIRE

    Bogie, Jeroen; Jorissen, Winde; Mailleux, Jo; Vanmierlo, Tim; van Horssen, Jack; Hellings, Niels; Stinissen, Piet; Hendriks, J. J. A.; Nijland, Philip G.; Zelcer, Noam

    2013-01-01

    Background Foamy macrophages, containing myelin degradation products, are abundantly found in active multiple sclerosis (MS) lesions. Recent studies have described an altered phenotype of macrophages after myelin internalization. However, mechanisms by which myelin affects the phenotype of macrophages and how this phenotype influences lesion progression remain unclear. Results We demonstrate that myelin as well as phosphatidylserine (PS), a phospholipid found in myelin, reduce nitri...

  15. Mitochondrial impairment induced by postnatal ActRIIB blockade does not alter function and energy status in exercising mouse glycolytic muscle in vivo.

    Science.gov (United States)

    Béchir, Nelly; Pecchi, Émilie; Relizani, Karima; Vilmen, Christophe; Le Fur, Yann; Bernard, Monique; Amthor, Helge; Bendahan, David; Giannesini, Benoît

    2016-04-01

    Because it leads to a rapid and massive muscle hypertrophy, postnatal blockade of the activin type IIB receptor (ActRIIB) is a promising therapeutic strategy for counteracting muscle wasting. However, the functional consequences remain very poorly documented in vivo. Here, we have investigated the impact of 8-wk ActRIIB blockade with soluble receptor (sActRIIB-Fc) on gastrocnemius muscle anatomy, energy metabolism, and force-generating capacity in wild-type mice, using totally noninvasive magnetic resonance imaging (MRI) and dynamic(31)P-MRS. Compared with vehicle (PBS) control, sActRIIB-Fc treatment resulted in a dramatic increase in body weight (+29%) and muscle volume (+58%) calculated from hindlimb MR imaging, but did not alter fiber type distribution determined via myosin heavy chain isoform analysis. In resting muscle, sActRIIB-Fc treatment induced acidosis and PCr depletion, thereby suggesting reduced tissue oxygenation. During an in vivo fatiguing exercise (6-min repeated maximal isometric contraction electrically induced at 1.7 Hz), maximal and total absolute forces were larger in sActRIIB-Fc treated animals (+26 and +12%, respectively), whereas specific force and fatigue resistance were lower (-30 and -37%, respectively). Treatment with sActRIIB-Fc further decreased the maximal rate of oxidative ATP synthesis (-42%) and the oxidative capacity (-34%), but did not alter the bioenergetics status in contracting muscle. Our findings demonstrate in vivo that sActRIIB-Fc treatment increases absolute force-generating capacity and reduces mitochondrial function in glycolytic gastrocnemius muscle, but this reduction does not compromise energy status during sustained activity. Overall, these data support the clinical interest of postnatal ActRIIB blockade. PMID:26837807

  16. Fuel-Stimulated Insulin Secretion Depends upon Mitochondria Activation and the Integration of Mitochondrial and Cytosolic Substrate Cycles

    OpenAIRE

    Gary W Cline

    2011-01-01

    The pancreatic islet β-cell is uniquely specialized to couple its metabolism and rates of insulin secretion with the levels of circulating nutrient fuels, with the mitochondrial playing a central regulatory role in this process. In the β-cell, mitochondrial activation generates an integrated signal reflecting rates of oxidativephosphorylation, Kreb's cycle flux, and anaplerosis that ultimately determines the rate of insulin exocytosis. Mitochondrial activation can be regulated by proton leak ...

  17. Copper deficiency alters cell bioenergetics and induces mitochondrial fusion through up-regulation of MFN2 and OPA1 in erythropoietic cells

    International Nuclear Information System (INIS)

    Highlights: •In copper deficiency, cell proliferation is not affected. In turn, cell differentiation is impaired. •Enlarged mitochondria are due to up-regulation of MNF2 and OPA1. •Mitochondria turn off respiratory chain and ROS production. •Energy metabolism switch from mitochondria to glycolysis. -- Abstract: Copper is essential in cell physiology, participating in numerous enzyme reactions. In mitochondria, copper is a cofactor for respiratory complex IV, the cytochrome c oxidase. Low copper content is associated with anemia and the appearance of enlarged mitochondria in erythropoietic cells. These findings suggest a connection between copper metabolism and bioenergetics, mitochondrial dynamics and erythropoiesis, which has not been explored so far. Here, we describe that bathocuproine disulfonate-induced copper deficiency does not alter erythropoietic cell proliferation nor induce apoptosis. However it does impair erythroid differentiation, which is associated with a metabolic switch between the two main energy-generating pathways. That is, from mitochondrial function to glycolysis. Switching off mitochondria implies a reduction in oxygen consumption and ROS generation along with an increase in mitochondrial membrane potential. Mitochondrial fusion proteins MFN2 and OPA1 were up-regulated along with the ability of mitochondria to fuse. Morphometric analysis of mitochondria did not show changes in total mitochondrial biomass but rather bigger mitochondria because of increased fusion. Similar results were also obtained with human CD34+, which were induced to differentiate into red blood cells. In all, we have shown that adequate copper levels are important for maintaining proper mitochondrial function and for erythroid differentiation where the energy metabolic switch plus the up-regulation of fusion proteins define an adaptive response to copper deprivation to keep cells alive

  18. Copper deficiency alters cell bioenergetics and induces mitochondrial fusion through up-regulation of MFN2 and OPA1 in erythropoietic cells

    Energy Technology Data Exchange (ETDEWEB)

    Bustos, Rodrigo I.; Jensen, Erik L.; Ruiz, Lina M.; Rivera, Salvador; Ruiz, Sebastián [Center for Biomedical Research, Faculty of Biological Sciences and Faculty of Medicine, Universidad Andres Bello, Santiago (Chile); Simon, Felipe; Riedel, Claudia [Center for Biomedical Research, Faculty of Biological Sciences and Faculty of Medicine, Universidad Andres Bello, Santiago (Chile); Millennium Institute of Immunology and Immunotherapy, Santiago (Chile); Ferrick, David [Seahorse Bioscience, Billerica, MA (United States); Elorza, Alvaro A., E-mail: aelorza@unab.cl [Center for Biomedical Research, Faculty of Biological Sciences and Faculty of Medicine, Universidad Andres Bello, Santiago (Chile); Millennium Institute of Immunology and Immunotherapy, Santiago (Chile)

    2013-08-02

    Highlights: •In copper deficiency, cell proliferation is not affected. In turn, cell differentiation is impaired. •Enlarged mitochondria are due to up-regulation of MNF2 and OPA1. •Mitochondria turn off respiratory chain and ROS production. •Energy metabolism switch from mitochondria to glycolysis. -- Abstract: Copper is essential in cell physiology, participating in numerous enzyme reactions. In mitochondria, copper is a cofactor for respiratory complex IV, the cytochrome c oxidase. Low copper content is associated with anemia and the appearance of enlarged mitochondria in erythropoietic cells. These findings suggest a connection between copper metabolism and bioenergetics, mitochondrial dynamics and erythropoiesis, which has not been explored so far. Here, we describe that bathocuproine disulfonate-induced copper deficiency does not alter erythropoietic cell proliferation nor induce apoptosis. However it does impair erythroid differentiation, which is associated with a metabolic switch between the two main energy-generating pathways. That is, from mitochondrial function to glycolysis. Switching off mitochondria implies a reduction in oxygen consumption and ROS generation along with an increase in mitochondrial membrane potential. Mitochondrial fusion proteins MFN2 and OPA1 were up-regulated along with the ability of mitochondria to fuse. Morphometric analysis of mitochondria did not show changes in total mitochondrial biomass but rather bigger mitochondria because of increased fusion. Similar results were also obtained with human CD34+, which were induced to differentiate into red blood cells. In all, we have shown that adequate copper levels are important for maintaining proper mitochondrial function and for erythroid differentiation where the energy metabolic switch plus the up-regulation of fusion proteins define an adaptive response to copper deprivation to keep cells alive.

  19. Propofol but not sevoflurane prevents mitochondrial dysfunction and oxidative stress by limiting HIF-1α activation in hepatic ischemia/reperfusion injury.

    Science.gov (United States)

    Bellanti, Francesco; Mirabella, Lucia; Mitarotonda, Domenica; Blonda, Maria; Tamborra, Rosanna; Cinnella, Gilda; Fersini, Alberto; Ambrosi, Antonio; Dambrosio, Michele; Vendemiale, Gianluigi; Serviddio, Gaetano

    2016-07-01

    Mitochondrial dysfunction, reactive oxygen species (ROS) production and oxidative stress during reperfusion are determinant in hepatic ischemia/reperfusion (I/R) injury but may be impacted by different anesthetic agents. Thus, we aimed at comparing the effects of inhaled sevoflurane or intravenous propofol anesthesia on liver mitochondria in a rodent model of hepatic I/R injury. To this, male Wistar rats underwent I/R surgery using sevoflurane or propofol. In the I/R model, propofol limited the raise in serum aminotransferase levels as compared to sevoflurane. Mitochondrial oxygen uptake, respiratory activity, membrane potential and proton leak were altered in I/R; however, this impairment was significantly prevented by propofol but not sevoflurane. In addition, differently from sevoflurane, propofol limited hepatic I/R-induced mitochondria H2O2 production rate, free radical leak and hydroxynonenal-protein adducts levels. The I/R group anesthetized with propofol also showed a better recovery of hepatic ATP homeostasis and conserved integrity of mitochondrial PTP. Moreover, hypoxia-inducible factor 1 alpha (HIF-1α) expression was limited in such group. By using a cell model of desferoxamine-dependent HIF activation, we demonstrated that propofol was able to inhibit apoptosis and mitochondrial depolarization associated to HIF-1α action. In conclusion, hepatic I/R injury induces mitochondrial dysfunction that is not prevented by inhaled sevoflurane. On the contrary, propofol reduces liver damage and mitochondrial dysfunction by preserving respiratory activity, membrane potential and energy homeostasis, and limiting free radicals production as well as PTP opening. These hepatoprotective effects may involve the inhibition of HIF-1α. PMID:27154980

  20. Alterations in HIV-1 LTR promoter activity during AIDS progression

    International Nuclear Information System (INIS)

    HIV-1 variants evolving in AIDS patients frequently show increased replicative capacity compared to those present during early asymptomatic infection. It is known that late stage HIV-1 variants often show an expanded coreceptor tropism and altered Nef function. In the present study we investigated whether enhanced HIV-1 LTR promoter activity might also evolve during disease progression. Our results demonstrate increased LTR promoter activity after AIDS progression in 3 of 12 HIV-1-infected individuals studied. Further analysis revealed that multiple alterations in the U3 core-enhancer and in the transactivation-response (TAR) region seem to be responsible for the enhanced functional activity. Our findings show that in a subset of HIV-1-infected individuals enhanced LTR transcription contributes to the increased replicative potential of late stage virus isolates and might accelerate disease progression

  1. Intrinsic Brain Activity in Altered States of Consciousness

    Science.gov (United States)

    Boly, M.; Phillips, C.; Tshibanda, L.; Vanhaudenhuyse, A.; Schabus, M.; Dang-Vu, T.T.; Moonen, G.; Hustinx, R.; Maquet, P.; Laureys, S.

    2010-01-01

    Spontaneous brain activity has recently received increasing interest in the neuroimaging community. However, the value of resting-state studies to a better understanding of brain–behavior relationships has been challenged. That altered states of consciousness are a privileged way to study the relationships between spontaneous brain activity and behavior is proposed, and common resting-state brain activity features observed in various states of altered consciousness are reviewed. Early positron emission tomography studies showed that states of extremely low or high brain activity are often associated with unconsciousness. However, this relationship is not absolute, and the precise link between global brain metabolism and awareness remains yet difficult to assert. In contrast, voxel-based analyses identified a systematic impairment of associative frontoparieto–cingulate areas in altered states of consciousness, such as sleep, anesthesia, coma, vegetative state, epileptic loss of consciousness, and somnambulism. In parallel, recent functional magnetic resonance imaging studies have identified structured patterns of slow neuronal oscillations in the resting human brain. Similar coherent blood oxygen level–dependent (BOLD) systemwide patterns can also be found, in particular in the default-mode network, in several states of unconsciousness, such as coma, anesthesia, and slow-wave sleep. The latter results suggest that slow coherent spontaneous BOLD fluctuations cannot be exclusively a reflection of conscious mental activity, but may reflect default brain connectivity shaping brain areas of most likely interactions in a way that transcends levels of consciousness, and whose functional significance remains largely in the dark. PMID:18591474

  2. Human activities change marine ecosystems by altering predation risk.

    Science.gov (United States)

    Madin, Elizabeth M P; Dill, Lawrence M; Ridlon, April D; Heithaus, Michael R; Warner, Robert R

    2016-01-01

    In ocean ecosystems, many of the changes in predation risk - both increases and decreases - are human-induced. These changes are occurring at scales ranging from global to local and across variable temporal scales. Indirect, risk-based effects of human activity are known to be important in structuring some terrestrial ecosystems, but these impacts have largely been neglected in oceans. Here, we synthesize existing literature and data to explore multiple lines of evidence that collectively suggest diverse human activities are changing marine ecosystems, including carbon storage capacity, in myriad ways by altering predation risk. We provide novel, compelling evidence that at least one key human activity, overfishing, can lead to distinct, cascading risk effects in natural ecosystems whose magnitude exceeds that of presumed lethal effects and may account for previously unexplained findings. We further discuss the conservation implications of human-caused indirect risk effects. Finally, we provide a predictive framework for when human alterations of risk in oceans should lead to cascading effects and outline a prospectus for future research. Given the speed and extent with which human activities are altering marine risk landscapes, it is crucial that conservation and management policy considers the indirect effects of these activities in order to increase the likelihood of success and avoid unfortunate surprises. PMID:26448058

  3. Proapoptotic activity of Ukrain is based on Chelidonium majus L. alkaloids and mediated via a mitochondrial death pathway

    Directory of Open Access Journals (Sweden)

    Plasswilm Ludwig

    2006-01-01

    from chemical synthesis. Instead, the Chelidonium majus L. alkaloids chelidonine, sanguinarine, chelerythrine, protopine and allocryptopine were identified as major components of Ukrain. Apart from sanguinarine and chelerythrine, chelidonine turned out to be a potent inducer of apoptosis triggering cell death at concentrations of 0.001 mM, while protopine and allocryptopine were less effective. Similar to Ukrain, apoptosis signalling of chelidonine involved Bcl-2 controlled mitochondrial alterations and caspase-activation. Conclusion The potent proapoptotic effects of Ukrain are not due to the suggested "Ukrain-molecule" but to the cytotoxic efficacy of Chelidonium majus L. alkaloids including chelidonine.

  4. Activity of carnitine palmitoyltransferase in mitochondrial outer membranes and peroxisomes in digitonin-permeabilized hepatocytes. Selective modulation of mitochondrial enzyme activity by okadaic acid.

    Science.gov (United States)

    Guzmán, M; Geelen, M J

    1992-01-01

    A procedure is described for the rapid measurement of the activity of mitochondrial-outer-membrane carnitine palmitoyltransferase (CPTo) and peroxisomal carnitine palmitoyltransferase (CPTp) in digitonin-permeabilized hepatocytes. CPTo activity was determined as the tetradecylglycidate (TDGA)-sensitive malonyl-CoA-sensitive CPT activity, whereas CPTp activity was monitored as the TDGA-insensitive malonyl-CoA-sensitive CPT activity. Under these experimental conditions, the respective contributions of CPTo and CPTp to total hepatocellular malonyl-CoA-sensitive CPT activity were 74.6 and 25.4%, which correlated well with the values of 76.9 and 23.1% for the respective contributions of the mitochondrial and the peroxisomal compartment to total hepatocellular palmitate oxidation. The sensitivity of CPTo to inhibition by malonyl-CoA was very similar to that of CPTp; thus 50% inhibition of CPTo and CPTp activities was achieved with malonyl-CoA concentrations of 2.6 +/- 0.5 and 3.0 +/- 0.4 microM respectively. Short-term incubation of hepatocytes with the phosphatase inhibitor okadaic acid (i) increased the activity of CPTo and the rate of mitochondrial palmitate oxidation, (ii) decreased the affinity of CPTo for palmitoyl-CoA substrate, and (iii) decreased the sensitivity of CPTo to inhibition by malonyl-CoA. By contrast, neither the properties of CPTp nor the rate of peroxisomal palmitate oxidation were changed upon incubation of cells with okadaic acid. Results indicate therefore that CPTo, but not CPTp, may be regulated by a mechanism of phosphorylation/dephosphorylation. The physiological relevance of these findings is discussed. PMID:1332675

  5. Mitochondrial aerobic respiration is activated during hair follicle stem cell differentiation, and its dysfunction retards hair regeneration

    OpenAIRE

    Tang, Yan; Luo, Binping; Deng, Zhili; Wang, Ben; Liu, Fangfen; Li, Jinmao; SHI, Wei; Xie, Hongfu; Hu, Xingwang; Li, Ji

    2016-01-01

    Background. Emerging research revealed the essential role of mitochondria in regulating stem/progenitor cell differentiation of neural progenitor cells, mesenchymal stem cells and other stem cells through reactive oxygen species (ROS), Notch or other signaling pathway. Inhibition of mitochondrial protein synthesis results in hair loss upon injury. However, alteration of mitochondrial morphology and metabolic function during hair follicle stem cells (HFSCs) differentiation and how they affect ...

  6. Desmodium gangeticum (Linn.) DC. exhibits antihypertrophic effect in isoproterenol-induced cardiomyoblasts via amelioration of oxidative stress and mitochondrial alterations.

    Science.gov (United States)

    Sankar, Vandana; Pangayarselvi, Balasubramaniam; Prathapan, Ayyappan; Raghu, Kozhiparambil Gopalan

    2013-01-01

    Cardiac hypertrophy occurs in response to increased workload, such as hypertension or valvular heart disease. Oxidative stress has been implicated in cardiac hypertrophy and in its transition to heart failure. This study was taken up with the objective to evaluate the role of oxidative stress in cardiomyoblast hypertrophy and its modulation by Desmodium gangeticum (DG) that has been traditionally used in Ayurveda, an Indian system of medicine. The methanolic root extract was analyzed for total phenolic content and tested for antioxidant potential. Hypertrophy was induced by exposing H9c2 cell line to β-adrenergic receptor agonist, isoproterenol (ISO), for 96 hours. Analyses of reactive oxygen species (ROS) generation, mitochondrial transmembrane potential ([INCREMENT]Ψm), and integrity of permeability transition were performed in ISO as well as Desmodium and ISO-cotreated cells. The results demonstrated potent free radical scavenging activity of DG. Cell line studies showed significant increase in ROS generation, dissipation of [INCREMENT]Ψm, and permeability transition pore opening in ISO-treated cells. Desmodium was found to attenuate ISO-induced hypertrophy by reduction of ROS generation, restoration of [INCREMENT]Ψm, and prevention of permeability transition pore opening. This study is the first documentation of the modulatory effect of DG on cardiac hypertrophy. PMID:23052030

  7. Mitochondrial biogenesis: pharmacological approaches.

    Science.gov (United States)

    Valero, Teresa

    2014-01-01

    of human diseases arising from defects in mitochondrial ion and ROS homeostasis, energy production and morphology [1]. Parkinson´s Disease (PD) is a very good example of this important mitochondrial component on neurodegenerative diseases. Anuradha Yadav, Swati Agrawal, Shashi Kant Tiwari, and Rajnish K. Chaturvedi (CSIR-Indian Institute of Toxicology Research / Academy of Scientific and Innovative Research, India) [6] remark in their review the role of mitochondrial dysfunction in PD with special focus on the role of oxidative stress and bioenergetic deficits. These alterations may have their origin on pathogenic gene mutations in important genes such as DJ-1, -syn, parkin, PINK1 or LRRK2. These mutations, in turn, may cause defects in mitochondrial dynamics (key events like fission/fusion, biogenesis, trafficking in retrograde and anterograde directions, and mitophagy). This work reviews different strategies to enhance mitochondrial bioenergetics in order to ameliorate the neurodegenerative process, with an emphasis on clinical trials reports that indicate their potential. Among them creatine, Coenzyme Q10 and mitochondrial targeted antioxidants/peptides are reported to have the most remarkable effects in clinical trials. They highlight a dual effect of PGC-1α expression on PD prognosis. Whereas a modest expression of this transcriptional co-activator results in positive effects, a moderate to substantial overexpession may have deleterious consequences. As strategies to induce PGC-1α activation, these authors remark the possibility to activate Sirt1 with resveratrol, to use PPAR agonists such as pioglitazone, rosiglitazone, fenofibrate and bezafibrate. Other strategies include the triggering of Nrf2/antioxidant response element (ARE) pathway by triterpenoids (derivatives of oleanolic acid) or by Bacopa monniera, the enhancement of ATP production by carnitine and -lipoic acid. Mitochondrial dysfunctions are the prime source of neurodegenerative diseases and

  8. Involvement of mitochondrial Na+–Ca2+ exchange in intestinal pacemaking activity

    OpenAIRE

    Kim, Byung Joo; Jun, Jae Yeoul; So, Insuk; Kim, Ki Whan

    2006-01-01

    AIM: Interstitial cells of Cajal (ICCs) are the pacemaker cells that generate slow waves in the gastrointestinal (GI) tract. We have aimed to investigate the involvement of mitochondrial Na+-Ca2+ exchange in intestinal pacemaking activity in cultured interstitial cells of Cajal.

  9. Study of mitochondrial DNA alteration in the exhaled breath condensate of patients affected by obstructive lung diseases.

    Science.gov (United States)

    Carpagnano, G E; Lacedonia, D; Carone, M; Soccio, P; Cotugno, G; Palmiotti, G A; Scioscia, G; Foschino Barbaro, M P

    2016-01-01

    Mitochondrial DNA (MtDNA) has been studied as an expression of oxidative stress in asthma, COPD, lung cancer and obstructive sleep apnea, but it has been mainly investigated systemically, although the pathogenetic mechanisms begin in the airways and only later progress to systemic circulation. The aim of this study was to investigate the MtDNA alterations in the exhaled breath condensate (EBC) of patients with asthma, COPD and asthma-COPD overlap syndrome (ACOS). In order to analyze better what happens to mitochondria, both locally and systemically, we compared MtDNA/nDNA in blood and EBC of paired patients. Thirteen (13) COPD patients, 14 asthmatics, 23 ACOS (10 according to Spanish guidelines, 13 in line with GINA guidelines) and 12 healthy subjects were enrolled. Patients underwent clinical and functional diagnostic tests as foreseen by the guidelines. They underwent blood and EBC collection. Content of MtDNA and nuclear DNA (nDNA) was measured in the blood cells and EBC of patients by Real Time PCR. The ratio between MtDNA/nDNA was calculated. For the first time we were able to detect MtDNA/nDNA in the EBC. We found higher exhaled MtDNA/nDNA in COPD, asthmatic and ACOS patients respectively compared to healthy subjects (21.9  ±  4.9 versus 6.51  ±  0.21, p  <  0.05; 7.9  ±  2.5 versus 6.51  ±  0.21, p  =  0.06; 18.3  ±  3.4 versus 6.51  ±  0.21, p  <  0.05). The level of exhaled MtDNA/nDNA was positively correlated with the plasmatic one. The levels of MtDNA/nDNA in the EBC, as expression of oxidative stress, are increased in COPD, asthmatic and ACOS patients compared to healthy subjects. These are preliminary results in a small number of well characterized patients that requires confirmation on a larger population. We support new studies directed toward the analysis of exhaled MtDNA/nDNA as a new exhaled non-invasive marker in other inflammatory/oxidative airways diseases. PMID

  10. Mitochondrial cytopathies.

    Science.gov (United States)

    El-Hattab, Ayman W; Scaglia, Fernando

    2016-09-01

    Mitochondria are found in all nucleated human cells and perform a variety of essential functions, including the generation of cellular energy. Most of mitochondrial proteins are encoded by the nuclear DNA (nDNA) whereas a very small fraction is encoded by the mitochondrial DNA (mtDNA). Mutations in mtDNA or mitochondria-related nDNA genes can result in mitochondrial dysfunction which leads to a wide range of cellular perturbations including aberrant calcium homeostasis, excessive reactive oxygen species production, dysregulated apoptosis, and insufficient energy generation to meet the needs of various organs, particularly those with high energy demand. Impaired mitochondrial function in various tissues and organs results in the multi-organ manifestations of mitochondrial diseases including epilepsy, intellectual disability, skeletal and cardiac myopathies, hepatopathies, endocrinopathies, and nephropathies. Defects in nDNA genes can be inherited in an autosomal or X-linked manners, whereas, mtDNA is maternally inherited. Mitochondrial diseases can result from mutations of nDNA genes encoding subunits of the electron transport chain complexes or their assembly factors, proteins associated with the mitochondrial import or networking, mitochondrial translation factors, or proteins involved in mtDNA maintenance. MtDNA defects can be either point mutations or rearrangements. The diagnosis of mitochondrial disorders can be challenging in many cases and is based on clinical recognition, biochemical screening, histopathological studies, functional studies, and molecular genetic testing. Currently, there are no satisfactory therapies available for mitochondrial disorders that significantly alter the course of the disease. Therapeutic options include symptomatic treatment, cofactor supplementation, and exercise. PMID:26996063

  11. Signs of Selection in Synonymous Sites of the Mitochondrial Cytochrome b Gene of Baikal Oilfish (Comephoridae by mRNA Secondary Structure Alterations

    Directory of Open Access Journals (Sweden)

    Veronika I. Teterina

    2015-01-01

    Full Text Available Studies over the past decade have shown a significant role of synonymous mutations in posttranscriptional regulation of gene expression, which is particularly associated with messenger RNA (mRNA secondary structure alterations. Most studies focused on prokaryote genomes and the nuclear genomes of eukaryotes while little is known about the regulation of mitochondrial DNA (mtDNA gene expression. This paper reveals signs of selection in synonymous sites of the mitochondrial cytochrome b gene (Cytb of Baikal oilfish or golomyankas (Comephoridae directed towards altering the secondary structure of the mRNA and probably altering the character of mtDNA gene expression. Our findings are based on comparisons of intraspecific genetic variation patterns of small golomyanka (Comephorus dybowski and two genetic groups of big golomyanka (Comephorus dybowskii. Two approaches were used: (i analysis of the distribution of synonymous mutations between weak-AT (W and strong-GC (S nucleotides within species and groups in accordance with mutation directions from central to peripheral haplotypes and (ii approaches based on the predicted mRNA secondary structure.

  12. Ionising radiation induces persistent alterations in the cardiac mitochondrial function of C57BL/6 mice 40 weeks after local heart exposure

    International Nuclear Information System (INIS)

    Background and purpose: Radiotherapy of thoracic and chest-wall tumours increases the long-term risk of radiation-induced heart disease. The aim of this study was to investigate the long-term effect of local heart irradiation on cardiac mitochondria. Methods: C57BL/6 and atherosclerosis-prone ApoE−/− mice received local heart irradiation with a single X-ray dose of 2 Gy. To investigate the low-dose effect, C57BL/6 mice also received a single heart dose of 0.2 Gy. Functional and proteomic alterations of cardiac mitochondria were evaluated after 40 weeks, compared to age-matched controls. Results: The respiratory capacity of irradiated C57BL/6 cardiac mitochondria was significantly reduced at 40 weeks. In parallel, protein carbonylation was increased, suggesting enhanced oxidative stress. Considerable alterations were found in the levels of proteins of mitochondria-associated cytoskeleton, respiratory chain, ion transport and lipid metabolism. Radiation induced similar but less pronounced effects in the mitochondrial proteome of ApoE−/− mice. In ApoE−/−, no significant change was observed in mitochondrial respiration or protein carbonylation. The dose of 0.2 Gy had no significant effects on cardiac mitochondria. Conclusion: This study suggests that ionising radiation causes non-transient alterations in cardiac mitochondria, resulting in oxidative stress that may ultimately lead to malfunctioning of the heart muscle

  13. Cilostazol promotes mitochondrial biogenesis in human umbilical vein endothelial cells through activating the expression of PGC-1α

    International Nuclear Information System (INIS)

    Highlights: ► First time to show that cilostazol promotes the expressions of PGC-1α. ► First time to show that cilostazol stimulates mitochondrial biogenesis in HUVECs. ► PKA/CREB pathway mediates the effect of cilostazol on PGC-1α expression. ► Suggesting the roles of cilostazol in mitochondrial dysfunction related disease. -- Abstract: Mitochondrial dysfunction is frequently observed in vascular diseases. Cilostazol is a drug approved by the US Food and Drug Administration for the treatment of intermittent claudication. Cilostazol increases intracellular cyclic adenosine monophosphate (cAMP) levels through inhibition of type III phosphodiesterase. The effects of cilostazol in mitochondrial biogenesis in human umbilical vein endothelial cells (HUVECs) were investigated in this study. Cilostazol treated HUVECs displayed increased levels of ATP, mitochondrial DNA/nuclear DNA ratio, expressions of cytochrome B, and mitochondrial mass, suggesting an enhanced mitochondrial biogenesis induced by cilostazol. The promoted mitochondrial biogenesis could be abolished by Protein kinase A (PKA) specific inhibitor H-89, implying that PKA pathway played a critical role in increased mitochondrial biogenesis after cilostazol treatment. Indeed, expression levels of peroxisome proliferator activator receptor gamma-coactivator 1α (PGC-1α), NRF 1 and mitochondrial transcription factor A (TFAM) were significantly increased in HUVECs after incubation with cilostazol at both mRNA levels and protein levels. Importantly, knockdown of PGC-1α could abolish cilostazol-induced mitochondrial biogenesis. Enhanced expression of p-CREB and PGC-1α induced by cilostazol could be inhibited by H-89. Moreover, the increased expression of PGC-1α induced by cilostazol could be inhibited by downregulation of CREB using CREB siRNA at both mRNA and protein levels. All the results indicated that cilostazol promoted mitochondrial biogenesis through activating the expression of PGC-1α in

  14. Cilostazol promotes mitochondrial biogenesis in human umbilical vein endothelial cells through activating the expression of PGC-1α

    Energy Technology Data Exchange (ETDEWEB)

    Zuo, Luning [Shandong University, 44 Wenhua Xi Road, Jinan, Shandong 250012 (China); Department of Cardiology, Yantaishan Hospital, Yantai, Shandong 264001 (China); Li, Qiang; Sun, Bei; Xu, Zhiying [Department of Cardiology, Yantaishan Hospital, Yantai, Shandong 264001 (China); Ge, Zhiming, E-mail: zhimingge2000@hotmail.com [Department of Cardiology, Qilu Hospital, Shandong University, 44 Wenhua Xi Road, Jinan, Shandong 250012 (China)

    2013-03-29

    Highlights: ► First time to show that cilostazol promotes the expressions of PGC-1α. ► First time to show that cilostazol stimulates mitochondrial biogenesis in HUVECs. ► PKA/CREB pathway mediates the effect of cilostazol on PGC-1α expression. ► Suggesting the roles of cilostazol in mitochondrial dysfunction related disease. -- Abstract: Mitochondrial dysfunction is frequently observed in vascular diseases. Cilostazol is a drug approved by the US Food and Drug Administration for the treatment of intermittent claudication. Cilostazol increases intracellular cyclic adenosine monophosphate (cAMP) levels through inhibition of type III phosphodiesterase. The effects of cilostazol in mitochondrial biogenesis in human umbilical vein endothelial cells (HUVECs) were investigated in this study. Cilostazol treated HUVECs displayed increased levels of ATP, mitochondrial DNA/nuclear DNA ratio, expressions of cytochrome B, and mitochondrial mass, suggesting an enhanced mitochondrial biogenesis induced by cilostazol. The promoted mitochondrial biogenesis could be abolished by Protein kinase A (PKA) specific inhibitor H-89, implying that PKA pathway played a critical role in increased mitochondrial biogenesis after cilostazol treatment. Indeed, expression levels of peroxisome proliferator activator receptor gamma-coactivator 1α (PGC-1α), NRF 1 and mitochondrial transcription factor A (TFAM) were significantly increased in HUVECs after incubation with cilostazol at both mRNA levels and protein levels. Importantly, knockdown of PGC-1α could abolish cilostazol-induced mitochondrial biogenesis. Enhanced expression of p-CREB and PGC-1α induced by cilostazol could be inhibited by H-89. Moreover, the increased expression of PGC-1α induced by cilostazol could be inhibited by downregulation of CREB using CREB siRNA at both mRNA and protein levels. All the results indicated that cilostazol promoted mitochondrial biogenesis through activating the expression of PGC-1α in

  15. Environmental noise alters gastric myoelectrical activity: Effect of age

    Institute of Scientific and Technical Information of China (English)

    James S Castle; Jin-Hong Xing; Mark R Warner; Mark A Korsten

    2007-01-01

    AIM: To evaluate the effect of age and acoustic stress on gastric myoelectrical activity (GMA) and autonomic nervous system function,METHODS: Twenty-one male subjects (age range 22-71years, mean 44 years) were recruited and exposed, in random order, to three auditory stimuli (Hospital noise,conversation babble and traffic noise) after a 20-min baseline. All periods lasted 20 min and were interspersed with a 10 min of recovery. GMA was obtained using a Synectics Microdigitrapper. Autonomic nerve function was assessed by monitoring blood pressure and heart rate using an automatic recording device.RESULTS: Dominant power tended to decrease with increase of age (P<0.05). The overall percentage of three cycle per minute (CPM) activity decreased during exposure to hospital noise (12.0%, P < 0.05), traffic noise (13.9%, P < 0.05), and conversation babble(7.1%). The subjects in the younger group (< 50 years)showed a consistent reduction in the percentage of 3CPM activity during hospital noise (22.9%, P < 0.05),traffic noise (19.0%, P < 0.05), and conversation babble(15.5%). These observations were accompanied by a significant increase in bradygastria: hospital noise (P< 0.05) and traffic noise (P < 0.05). In contrast, the subjects over 50 years of age did not exhibit a significant decrease in 3 CPM activity. Regardless of age, noise did not alter blood pressure or heart rate.CONCLUSION: GMA changes with age. Loud noise can alter GMA, especially in younger individuals. Our data indicate that even short-term exposure to noise may alter the contractility of the stomach.

  16. Nucleus accumbens deep-brain stimulation efficacy in ACTH-pretreated rats: alterations in mitochondrial function relate to antidepressant-like effects

    Science.gov (United States)

    Kim, Y; McGee, S; Czeczor, J K; Walker, A J; Kale, R P; Kouzani, A Z; Walder, K; Berk, M; Tye, S J

    2016-01-01

    Mitochondrial dysfunction has a critical role in the pathophysiology of mood disorders and treatment response. To investigate this, we established an animal model exhibiting a state of antidepressant treatment resistance in male Wistar rats using 21 days of adrenocorticotropic hormone (ACTH) administration (100 μg per day). First, the effect of ACTH treatment on the efficacy of imipramine (10 mg kg−1) was investigated alongside its effect on the prefrontal cortex (PFC) mitochondrial function. Second, we examined the mood-regulatory actions of chronic (7 day) high-frequency nucleus accumbens (NAc) deep-brain stimulation (DBS; 130 Hz, 100 μA, 90 μS) and concomitant PFC mitochondrial function. Antidepressant-like responses were assessed in the open field test (OFT) and forced swim test (FST) for both conditions. ACTH pretreatment prevented imipramine-mediated improvement in mobility during the FST (Panimals (Panimals (P>0.05). Analyses of PFC mitochondrial function revealed that ACTH-treated animals had decreased capacity for adenosine triphosphate production compared with controls. In contrast, ACTH animals following NAc DBS demonstrated greater mitochondrial function relative to controls. Interestingly, a proportion (30%) of the ACTH-treated animals exhibited heightened locomotor activity in the OFT and exaggerated escape behaviors during the FST, together with general hyperactivity in their home-cage settings. More importantly, the induction of this mania-like phenotype was accompanied by overcompensative increased mitochondrial respiration. Manifestation of a DBS-induced mania-like phenotype in imipramine-resistant animals highlights the potential use of this model in elucidating mechanisms of mood dysregulation. PMID:27327257

  17. Nucleus accumbens deep-brain stimulation efficacy in ACTH-pretreated rats: alterations in mitochondrial function relate to antidepressant-like effects.

    Science.gov (United States)

    Kim, Y; McGee, S; Czeczor, J K; Walker, A J; Kale, R P; Kouzani, A Z; Walder, K; Berk, M; Tye, S J

    2016-01-01

    Mitochondrial dysfunction has a critical role in the pathophysiology of mood disorders and treatment response. To investigate this, we established an animal model exhibiting a state of antidepressant treatment resistance in male Wistar rats using 21 days of adrenocorticotropic hormone (ACTH) administration (100 μg per day). First, the effect of ACTH treatment on the efficacy of imipramine (10 mg kg(-1)) was investigated alongside its effect on the prefrontal cortex (PFC) mitochondrial function. Second, we examined the mood-regulatory actions of chronic (7 day) high-frequency nucleus accumbens (NAc) deep-brain stimulation (DBS; 130 Hz, 100 μA, 90 μS) and concomitant PFC mitochondrial function. Antidepressant-like responses were assessed in the open field test (OFT) and forced swim test (FST) for both conditions. ACTH pretreatment prevented imipramine-mediated improvement in mobility during the FST (Panimals (Panimals (P>0.05). Analyses of PFC mitochondrial function revealed that ACTH-treated animals had decreased capacity for adenosine triphosphate production compared with controls. In contrast, ACTH animals following NAc DBS demonstrated greater mitochondrial function relative to controls. Interestingly, a proportion (30%) of the ACTH-treated animals exhibited heightened locomotor activity in the OFT and exaggerated escape behaviors during the FST, together with general hyperactivity in their home-cage settings. More importantly, the induction of this mania-like phenotype was accompanied by overcompensative increased mitochondrial respiration. Manifestation of a DBS-induced mania-like phenotype in imipramine-resistant animals highlights the potential use of this model in elucidating mechanisms of mood dysregulation. PMID:27327257

  18. Denbinobin induces apoptosis in human lung adenocarcinoma cells via Akt inactivation, Bad activation, and mitochondrial dysfunction.

    Science.gov (United States)

    Kuo, Chen-Tzu; Hsu, Ming-Jen; Chen, Bing-Chang; Chen, Chien-Chih; Teng, Che-Ming; Pan, Shiow-Lin; Lin, Chien-Huang

    2008-02-28

    Increasing evidence demonstrated that denbinobin, isolated from Ephemerantha lonchophylla, exert cytotoxic effects in cancer cells. The purpose of this study was to investigate whether denbinobin induces apoptosis and the apoptotic mechanism of denbinobin in human lung adenocarcinoma cells (A549). Denbinobin (1-20microM) caused cell death in a concentration-dependent manner. Flow cytometric analysis and annexin V labeling demonstrated that denbinobin increased the percentage of apoptotic cells. A549 cells treated with denbinobin showed typical characteristics of apoptosis including morphological changes and DNA fragmentation. Denbinobin induced caspase 3 activation, and N-benzyloxycarbonyl-Val-Ala-Asp-fluoromethylketone (zVAD-fmk), a broad-spectrum caspase inhibitor, prevented denbinobin-induced cell death. Denbinobin induced the loss of the mitochondrial membrane potential and the release of mitochondrial apoptotic proteins including cytochrome c, second mitochondria derived activator of caspase (Smac), and apoptosis-inducing factor (AIF). In addition, denbinobin-induced Bad activation was accompanied by the dissociation of Bad with 14-3-3 and the association of Bad with Bcl-xL. Furthermore, denbinobin induced Akt inactivation in a time-dependent manner. Transfection of A549 cells with both wild-type and constitutively active Akt significantly suppressed denbinobin-induced Bad activation and cell apoptosis. These results suggest that Akt inactivation, followed by Bad activation, mitochondrial dysfunction, caspase 3 activation, and AIF release, contributes to denbinobin-induced cell apoptosis. PMID:18262737

  19. A Ca2+-induced mitochondrial permeability transition causes complete release of rat liver endonuclease G activity from its exclusive location within the mitochondrial intermembrane space. Identification of a novel endo-exonuclease activity residing within the mitochondrial matrix

    OpenAIRE

    Davies, Adrian M.; Hershman, Stuart; Stabley, Gabriel J.; Hoek, Jan B.; Peterson, Jason; Cahill, Alan

    2003-01-01

    Endonuclease G, a protein historically thought to be involved in mitochondrial DNA (mtDNA) replication, repair, recombination and degradation, has recently been reported to be involved in nuclear DNA degradation during the apoptotic process. As a result, its involvement in mtDNA homeostasis has been called into question and has necessitated detailed analyses of its precise location within the mitochondrion. Data is presented localizing rat liver endonuclease G activity exclusively to the mito...

  20. Implications of mitochondrial dynamics on neurodegeneration and on hypothalamic dysfunction

    Directory of Open Access Journals (Sweden)

    Antonio eZorzano

    2015-06-01

    Full Text Available Mitochondrial dynamics is a term that encompasses the movement of mitochondria along the cytoskeleton, regulation of their architecture, and connectivity mediated by tethering and fusion/fission. The importance of these events in cell physiology and pathology has been partially unraveled with the identification of the genes responsible for the catalysis of mitochondrial fusion and fission. Mutations in two mitochondrial fusion genes (MFN2 and OPA1 cause neurodegenerative diseases, namely Charcot-Marie Tooth type 2A and autosomal dominant optic atrophy. Alterations in mitochondrial dynamics may be involved in the pathophysiology of prevalent neurodegenerative conditions. Moreover, impairment of the activity of mitochondrial fusion proteins dysregulates the function of hypothalamic neurons, leading to alterations in food intake and in energy homeostasis. Here we review selected findings in the field of mitochondrial dynamics and their relevance for neurodegeneration and hypothalamic dysfunction.

  1. MITOCHONDRIAL OXIDANT STRESS INCREASES PDE5 ACTIVITY IN PERSISTENT PULMONARY HYPERTENSION OF THE NEWBORN

    OpenAIRE

    Farrow, Kathryn N.; Wedgwood, Stephen; Lee, Keng Jin; Czech, Lyubov; Gugino, Sylvia F.; Lakshminrusimha, Satyan; Schumacker, Paul T.; Steinhorn, Robin H.

    2010-01-01

    In the pulmonary vasculature, phosphodiesterase-5 (PDE5) degrades cGMP and inhibits nitric oxide-mediated, cGMP-dependent vasorelaxation. We previously reported that ventilation with 100% O2 increased PDE5 activity in pulmonary arteries (PA) of pulmonary hypertension lambs (PPHN) more than in control lambs. In the present study, PA smooth muscle cells (PASMC) from PPHN lambs had increased basal PDE5 activity, decreased cGMP-responsiveness to NO, and increased mitochondrial matrix oxidant stre...

  2. Refeeding alters superoxide dismutase activity in Chinese hamster ovary cells

    International Nuclear Information System (INIS)

    The authors previously showed superoxide dismutase (SOD) activity is increased in heat shocked Chinese hamster ovary (CHO) and ovarian carcinoma (OvCa) cells during the time period when thermotolerance (TT) is observed (Ca Res 45,3029). SOD is also increased in OvCa cells following transient exposure to ethanol, carbonyl cyanide-N-chlorophenyl-hydrazone, or hypoxia; all treatments which induce TT (1986 Rad Res Abstr Co-2). As these experiments involved refeeding of cell cultures, the authors examined the effect of refeeding on SOD in CHO cells. Refeeding confluent CHO cells with fresh McCoy's 5A medium containing 10% FCS decreased SOD 0 to 6 hours after refeeding, which was due to loss of the mitochondrial or Mn SOD. Addition of glucose to the medium at the concentration originally found in the medium caused a similar decline in SOD. At 6-24 hours after refeeding or the addition of glucose an increase in Mn SOD was observed. These results suggest metabolic status can affect Mn SOD in the cell. The possible role of metabolic regulation of SOD in heat sensitivity is being investigated

  3. Altered brain activity for phonological manipulation in dyslexic Japanese children

    Science.gov (United States)

    Yamamoto, Hisako; Oba, Kentaro; Terasawa, Yuri; Moriguchi, Yoshiya; Uchiyama, Hitoshi; Seki, Ayumi; Koeda, Tatsuya; Inagaki, Masumi

    2013-01-01

    Because of unique linguistic characteristics, the prevalence rate of developmental dyslexia is relatively low in the Japanese language. Paradoxically, Japanese children have serious difficulty analysing phonological processes when they have dyslexia. Neurobiological deficits in Japanese dyslexia remain unclear and need to be identified, and may lead to better understanding of the commonality and diversity in the disorder among different linguistic systems. The present study investigated brain activity that underlies deficits in phonological awareness in Japanese dyslexic children using functional magnetic resonance imaging. We developed and conducted a phonological manipulation task to extract phonological processing skills and to minimize the influence of auditory working memory on healthy adults, typically developing children, and dyslexic children. Current experiments revealed that several brain regions participated in manipulating the phonological information including left inferior and middle frontal gyrus, left superior temporal gyrus, and bilateral basal ganglia. Moreover, dyslexic children showed altered activity in two brain regions. They showed hyperactivity in the basal ganglia compared with the two other groups, which reflects inefficient phonological processing. Hypoactivity in the left superior temporal gyrus was also found, suggesting difficulty in composing and processing phonological information. The altered brain activity shares similarity with those of dyslexic children in countries speaking alphabetical languages, but disparity also occurs between these two populations. These are initial findings concerning the neurobiological impairments in dyslexic Japanese children. PMID:24052613

  4. Mitochondrial Metabolism in Aging Heart.

    Science.gov (United States)

    Lesnefsky, Edward J; Chen, Qun; Hoppel, Charles L

    2016-05-13

    Altered mitochondrial metabolism is the underlying basis for the increased sensitivity in the aged heart to stress. The aged heart exhibits impaired metabolic flexibility, with a decreased capacity to oxidize fatty acids and enhanced dependence on glucose metabolism. Aging impairs mitochondrial oxidative phosphorylation, with a greater role played by the mitochondria located between the myofibrils, the interfibrillar mitochondria. With aging, there is a decrease in activity of complexes III and IV, which account for the decrease in respiration. Furthermore, aging decreases mitochondrial content among the myofibrils. The end result is that in the interfibrillar area, there is ≈50% decrease in mitochondrial function, affecting all substrates. The defective mitochondria persist in the aged heart, leading to enhanced oxidant production and oxidative injury and the activation of oxidant signaling for cell death. Aging defects in mitochondria represent new therapeutic targets, whether by manipulation of the mitochondrial proteome, modulation of electron transport, activation of biogenesis or mitophagy, or the regulation of mitochondrial fission and fusion. These mechanisms provide new ways to attenuate cardiac disease in elders by preemptive treatment of age-related defects, in contrast to the treatment of disease-induced dysfunction. PMID:27174952

  5. Proteomic alterations of distinct mitochondrial subpopulations in the type 1 diabetic heart: contribution of protein import dysfunction

    OpenAIRE

    Baseler, Walter A.; Dabkowski, Erinne R.; Williamson, Courtney L.; Croston, Tara L.; Thapa, Dharendra; Powell, Matthew J.; Razunguzwa, Trust T.; Hollander, John M.

    2010-01-01

    Diabetic cardiomyopathy is associated with increased risk of heart failure in type 1 diabetic patients. Mitochondrial dysfunction is suggested as an underlying contributor to diabetic cardiomyopathy. Cardiac mitochondria are characterized by subcellular spatial locale, including mitochondria located beneath the sarcolemma, subsarcolemmal mitochondria (SSM), and mitochondria situated between the myofibrils, interfibrillar mitochondria (IFM). The goal of this study was to determine whether type...

  6. Mitochondrial Dysfunction: Different Routes to Alzheimer’s Disease Therapy

    Directory of Open Access Journals (Sweden)

    Pasquale Picone

    2014-01-01

    Full Text Available Mitochondria are dynamic ATP-generating organelle which contribute to many cellular functions including bioenergetics processes, intracellular calcium regulation, alteration of reduction-oxidation potential of cells, free radical scavenging, and activation of caspase mediated cell death. Mitochondrial functions can be negatively affected by amyloid β peptide (Aβ, an important component in Alzheimer’s disease (AD pathogenesis, and Aβ can interact with mitochondria and cause mitochondrial dysfunction. One of the most accepted hypotheses for AD onset implicates that mitochondrial dysfunction and oxidative stress are one of the primary events in the insurgence of the pathology. Here, we examine structural and functional mitochondrial changes in presence of Aβ. In particular we review data concerning Aβ import into mitochondrion and its involvement in mitochondrial oxidative stress, bioenergetics, biogenesis, trafficking, mitochondrial permeability transition pore (mPTP formation, and mitochondrial protein interaction. Moreover, the development of AD therapy targeting mitochondria is also discussed.

  7. Effect of cryopreservation on mitochondrial activity in buffalo sperm Bubalus bubalis

    Directory of Open Access Journals (Sweden)

    O. Kandil

    2010-02-01

    Full Text Available Sperm mitochondrial activity is investigated and used as “in vitro” spermatozoa vitality indicator and about quality effectiveness of different sperm diluents. It was studied the cytochemically activity of NADPH-diaphorase and LDH-C4 in cryopreserved buffalo sperm. Low intensity of the enzyme reaction was established in all examined sperm samples in both enzymes, regardless from the used cryoprotectors. The main part of the enzyme reaction was localized in mitochondrial sheath and in a very small degree in the head base of spermatozoa. No increase of the enzymes activities or the spermatozoa motility has been found after the incubating with Sp-TALP medium although the established caffeine stimulating effect on the glycolysis and fresh spermatozoa motility. Established by us low sperm motility after cryopreservation may be due to low LDH and NADPH-diaphorase activity due to glycolisis disturbances and ATP synthesis. This method allows to estimate quality of buffalo semen and to find some different disturbances in mitochondrial sheath, which could not be found by routine morphological studies and could be used in practice ejaculates with high number of metabolic active sperm cells.

  8. Korean mistletoe (Viscum album coloratum) extract improves endurance capacity in mice by stimulating mitochondrial activity.

    Science.gov (United States)

    Jung, Hoe-Yune; Lee, An-Na; Song, Tae-Jun; An, Hyo-Sun; Kim, Young-Hoon; Kim, Kyu-Dae; Kim, In-Bo; Kim, Kyoung-Shim; Han, Baek-Soo; Kim, Chun-Hyung; Kim, Kwang-Soo; Kim, Jong-Bae

    2012-07-01

    The beneficial effects of exercise on overall health make it desirable to identify the orally active agents that enhance the effects of exercise in an effort to cure metabolic diseases. Natural compounds such as resveratrol (RSV) are known to increase endurance by potentiating mitochondrial function. Korean mistletoe (Viscum album coloratum) extract (KME) has characteristics similar to those of RSV. In the present study, we determined whether KME could increase mitochondrial activity and exert an anti-fatigue effect. We found that KME treatment significantly increased the mitochondrial oxygen consumption rate (OCR) in L6 cells and increased the expression of peroxisome proliferator-activated receptor γ coactivator (PGC)-1α and silent mating type information regulation 2 homolog 1 (SIRT1), two major regulators of mitochondria function, in C2C12 cells. In the treadmill test, KME-treated mice could run 2.5-times longer than chow-fed control mice. Additionally, plasma lactate levels of exhausted mice were significantly lower in the KME-treated group. In addition, the swimming time to exhaustion of mice treated with KME was prolonged by as much as 212% in the forced-swim test. Liver and kidney histology was similar between the KME-treated and phosphate-buffered saline-treated animals, indicating that KME was nontoxic. Taken together, our data show that KME induces mitochondrial activity, possibly by activating PGC-1α and SIRT1, and improves the endurance of mice, strongly suggesting that KME has great potential as a novel mitochondria-activating agent. PMID:22612297

  9. Structural basis for S-adenosylmethionine binding and methyltransferase activity by mitochondrial transcription factor B1.

    Science.gov (United States)

    Guja, Kip E; Venkataraman, Krithika; Yakubovskaya, Elena; Shi, Hui; Mejia, Edison; Hambardjieva, Elena; Karzai, A Wali; Garcia-Diaz, Miguel

    2013-09-01

    Eukaryotic transcription factor B (TFB) proteins are homologous to KsgA/Dim1 ribosomal RNA (rRNA) methyltransferases. The mammalian TFB1, mitochondrial (TFB1M) factor is an essential protein necessary for mitochondrial gene expression. TFB1M mediates an rRNA modification in the small ribosomal subunit and thus plays a role analogous to KsgA/Dim1 proteins. This modification has been linked to mitochondrial dysfunctions leading to maternally inherited deafness, aminoglycoside sensitivity and diabetes. Here, we present the first structural characterization of the mammalian TFB1 factor. We have solved two X-ray crystallographic structures of TFB1M with (2.1 Å) and without (2.0 Å) its cofactor S-adenosyl-L-methionine. These structures reveal that TFB1M shares a conserved methyltransferase core with other KsgA/Dim1 methyltransferases and shed light on the structural basis of S-adenosyl-L-methionine binding and methyltransferase activity. Together with mutagenesis studies, these data suggest a model for substrate binding and provide insight into the mechanism of methyl transfer, clarifying the role of this factor in an essential process for mitochondrial function. PMID:23804760

  10. Chlorogenic acid ameliorates intestinal mitochondrial injury by increasing antioxidant effects and activity of respiratory complexes.

    Science.gov (United States)

    Zhou, Yan; Zhou, Lili; Ruan, Zheng; Mi, Shumei; Jiang, Min; Li, Xiaolan; Wu, Xin; Deng, Zeyuan; Yin, Yulong

    2016-05-01

    Dietary polyphenols are thought to be beneficial for human health by acting as antioxidants. Chlorogenic acid (CGA) is abundant in plant-based foods as an ester of caffeic acid and quinic acid. In this study, we investigated the effects of CGA on mitochondrial protection. Our results demonstrated that pretreatment with CGA ameliorated the intestinal mitochondrial injury induced by H2O2; membrane potential was increased, mitochondrial swelling, levels of reactive oxygen species, contents of 8-hydroxy-2-deoxyguanosine, and cytochrome c released were decreased. The beneficial effects of CGA were accompanied by an increase in antioxidant and respiratory-chain complex I, IV, and V activities. In trinitrobenzene-sulfonic acid-induced colitic rats indicated that CGA supplementation improved mitochondria ultrastructure and decreased mitochondrial injury. Our results suggest a promising role for CGA as a mitochondria-targeted antioxidant in combating intestinal oxidative injury. Daily intake of diets containing CGA, such as coffee and honeysuckle, may be useful for prevention of intestinal diseases. PMID:26824685

  11. Mitochondrial tRNA cleavage by tRNA-targeting ribonuclease causes mitochondrial dysfunction observed in mitochondrial disease

    Energy Technology Data Exchange (ETDEWEB)

    Ogawa, Tetsuhiro, E-mail: atetsu@mail.ecc.u-tokyo.ac.jp; Shimizu, Ayano; Takahashi, Kazutoshi; Hidaka, Makoto; Masaki, Haruhiko, E-mail: amasaki@mail.ecc.u-tokyo.ac.jp

    2014-08-15

    Highlights: • MTS-tagged ribonuclease was translocated successfully to the mitochondrial matrix. • MTS-tagged ribonuclease cleaved mt tRNA and reduced COX activity. • Easy and reproducible method of inducing mt tRNA dysfunction. - Abstract: Mitochondrial DNA (mtDNA) is a genome possessed by mitochondria. Since reactive oxygen species (ROS) are generated during aerobic respiration in mitochondria, mtDNA is commonly exposed to the risk of DNA damage. Mitochondrial disease is caused by mitochondrial dysfunction, and mutations or deletions on mitochondrial tRNA (mt tRNA) genes are often observed in mtDNA of patients with the disease. Hence, the correlation between mt tRNA activity and mitochondrial dysfunction has been assessed. Then, cybrid cells, which are constructed by the fusion of an enucleated cell harboring altered mtDNA with a ρ{sup 0} cell, have long been used for the analysis due to difficulty in mtDNA manipulation. Here, we propose a new method that involves mt tRNA cleavage by a bacterial tRNA-specific ribonuclease. The ribonuclease tagged with a mitochondrial-targeting sequence (MTS) was successfully translocated to the mitochondrial matrix. Additionally, mt tRNA cleavage, which resulted in the decrease of cytochrome c oxidase (COX) activity, was observed.

  12. Mitochondrial tRNA cleavage by tRNA-targeting ribonuclease causes mitochondrial dysfunction observed in mitochondrial disease

    International Nuclear Information System (INIS)

    Highlights: • MTS-tagged ribonuclease was translocated successfully to the mitochondrial matrix. • MTS-tagged ribonuclease cleaved mt tRNA and reduced COX activity. • Easy and reproducible method of inducing mt tRNA dysfunction. - Abstract: Mitochondrial DNA (mtDNA) is a genome possessed by mitochondria. Since reactive oxygen species (ROS) are generated during aerobic respiration in mitochondria, mtDNA is commonly exposed to the risk of DNA damage. Mitochondrial disease is caused by mitochondrial dysfunction, and mutations or deletions on mitochondrial tRNA (mt tRNA) genes are often observed in mtDNA of patients with the disease. Hence, the correlation between mt tRNA activity and mitochondrial dysfunction has been assessed. Then, cybrid cells, which are constructed by the fusion of an enucleated cell harboring altered mtDNA with a ρ0 cell, have long been used for the analysis due to difficulty in mtDNA manipulation. Here, we propose a new method that involves mt tRNA cleavage by a bacterial tRNA-specific ribonuclease. The ribonuclease tagged with a mitochondrial-targeting sequence (MTS) was successfully translocated to the mitochondrial matrix. Additionally, mt tRNA cleavage, which resulted in the decrease of cytochrome c oxidase (COX) activity, was observed

  13. Homologous DNA strand exchange activity of the human mitochondrial DNA helicase TWINKLE.

    Science.gov (United States)

    Sen, Doyel; Patel, Gayatri; Patel, Smita S

    2016-05-19

    A crucial component of the human mitochondrial DNA replisome is the ring-shaped helicase TWINKLE-a phage T7-gene 4-like protein expressed in the nucleus and localized in the human mitochondria. Our previous studies showed that despite being a helicase, TWINKLE has unique DNA annealing activity. At the time, the implications of DNA annealing by TWINKLE were unclear. Herein, we report that TWINKLE uses DNA annealing function to actively catalyze strand-exchange reaction between the unwinding substrate and a homologous single-stranded DNA. Using various biochemical experiments, we demonstrate that the mechanism of strand-exchange involves active coupling of unwinding and annealing reactions by the TWINKLE. Unlike strand-annealing, the strand-exchange reaction requires nucleotide hydrolysis and greatly stimulated by short region of homology between the recombining DNA strands that promote joint molecule formation to initiate strand-exchange. Furthermore, we show that TWINKLE catalyzes branch migration by resolving homologous four-way junction DNA. These four DNA modifying activities of TWINKLE: strand-separation, strand-annealing, strand-exchange and branch migration suggest a dual role of TWINKLE in mitochondrial DNA maintenance. In addition to playing a major role in fork progression during leading strand DNA synthesis, we propose that TWINKLE is involved in recombinational repair of the human mitochondrial DNA. PMID:26887820

  14. Diabetes and activation of peroxisome proliferator activated receptor alpha increases mitochondrial thioesterase I protein expression and activity in the heart

    Science.gov (United States)

    Mitochondrial thioesterase-I (MTE-I) catalyzes the de-esterification of fattyacyl-CoAs to fatty acid anions in the mitochondrial matrix, which are extruded to the cytosol, thus preventing the accumulation of toxic mitochondrial fattyacyl-CoAs. MTE-I mRNA expression in the heart is regulated by perox...

  15. Reduced mitochondrial malate dehydrogenase activity has a strong effect on photorespiratory metabolism as revealed by 13C labelling.

    Science.gov (United States)

    Lindén, Pernilla; Keech, Olivier; Stenlund, Hans; Gardeström, Per; Moritz, Thomas

    2016-05-01

    Mitochondrial malate dehydrogenase (mMDH) catalyses the interconversion of malate and oxaloacetate (OAA) in the tricarboxylic acid (TCA) cycle. Its activity is important for redox control of the mitochondrial matrix, through which it may participate in regulation of TCA cycle turnover. In Arabidopsis, there are two isoforms of mMDH. Here, we investigated to which extent the lack of the major isoform, mMDH1 accounting for about 60% of the activity, affected leaf metabolism. In air, rosettes of mmdh1 plants were only slightly smaller than wild type plants although the fresh weight was decreased by about 50%. In low CO2 the difference was much bigger, with mutant plants accumulating only 14% of fresh weight as compared to wild type. To investigate the metabolic background to the differences in growth, we developed a (13)CO2 labelling method, using a custom-built chamber that enabled simultaneous treatment of sets of plants under controlled conditions. The metabolic profiles were analysed by gas- and liquid- chromatography coupled to mass spectrometry to investigate the metabolic adjustments between wild type and mmdh1 The genotypes responded similarly to high CO2 treatment both with respect to metabolite pools and (13)C incorporation during a 2-h treatment. However, under low CO2 several metabolites differed between the two genotypes and, interestingly most of these were closely associated with photorespiration. We found that while the glycine/serine ratio increased, a concomitant altered glutamine/glutamate/α-ketoglutarate relation occurred. Taken together, our results indicate that adequate mMDH activity is essential to shuttle reductants out from the mitochondria to support the photorespiratory flux, and strengthen the idea that photorespiration is tightly intertwined with peripheral metabolic reactions. PMID:26889011

  16. Active digestion of sperm mitochondrial DNA in single living sperm revealed by optical tweezers

    OpenAIRE

    Nishimura, Yoshiki; Yoshinari, Tomoya; Naruse, Kiyoshi; Yamada, Takeshi; Sumi, Kazuyoshi; Mitani, Hiroshi; Higashiyama, Tetsuya; Kuroiwa, Tsuneyoshi

    2006-01-01

    In almost all eukaryotes, mitochondrial (mt) genes are transmitted to progeny mainly from the maternal parent. The most popular explanation for this phenomenon is simple dilution of paternal mtDNA, because the paternal gametes (sperm) are much smaller than maternal gametes (egg) and contribute a limited amount of mitochondria to the progeny. Recently, this simple explanation has been challenged in several reports that describe the active digestion of sperm mtDNA, down-regulation of mtDNA repl...

  17. p53-mediated activation of the mitochondrial protease HtrA2/Omi prevents cell invasion

    OpenAIRE

    Yamauchi, Shota; Hou, Yan Yan; Guo, Alvin Kunyao; Hirata, Hiroaki; Nakajima, Wataru; Yip, Ai Kia; Yu, Cheng-Han; Harada, Ichiro; Chiam, Keng-Hwee; Sawada, Yasuhiro; Tanaka, Nobuyuki; Kawauchi, Keiko

    2014-01-01

    Oncogenic Ras induces cell transformation and promotes an invasive phenotype. The tumor suppressor p53 has a suppressive role in Rasdriven invasion. However, its mechanism remains poorly understood. Here we show that p53 induces activation of the mitochondrial protease high-temperature requirement A2 (HtrA2; also known as Omi) and prevents Ras-driven invasion by modulating the actin cytoskeleton. Oncogenic Ras increases accumulation of p53 in the cytoplasm, which promotes the translocation of...

  18. Mitochondrial DNA Haplogroups influence lipoatrophy after Highly Active Anti-retroviral Therapy

    OpenAIRE

    Hendrickson, Sher L.; Kingsley, Lawrence A; Ruiz-Pesini, Eduardo; Poole, Jason C.; Jacobson, Lisa P.; Palella, Frank J.; Bream, Jay H.; Wallace, Douglas C.; O’Brien, Stephen J.

    2009-01-01

    Although highly active retroviral therapy (HAART) has been extremely effective in lowering AIDS incidence among patients infected with HIV, certain drugs included in HAART can cause serious mitochondrial toxicities. One of the most frequent adverse events is lipoatrophy, which is the loss of subcutaneous fat in the face, arms, buttocks and/or legs as an adverse reaction to nucleoside reverse transcriptase inhibitors (NRTIs). The clinical symptoms of lipoatrophy resemble those of inherited mit...

  19. Exercise‐induced alterations in pancreatic oxidative stress and mitochondrial function in type 2 diabetic Goto‐Kakizaki rats

    OpenAIRE

    Raza, Haider; John, Annie; Shafarin, Jasmin; Howarth, Frank C.

    2016-01-01

    Abstract Progressive metabolic complications accompanied by oxidative stress are the hallmarks of type 2 diabetes. The precise molecular mechanisms of the disease complications, however, remain elusive. Exercise‐induced nontherapeutic management of type 2 diabetes is the first line of choice to control hyperglycemia and diabetes associated complications. In this study, using 11‐month‐old type 2 Goto‐Kakizaki (GK) rats, we have investigated the effects of exercise on mitochondrial metabolic an...

  20. Alteration of the mitochondrial apoptotic pathway is key to acquired paclitaxel resistance and can be reversed by ABT-737

    OpenAIRE

    Kutuk, Ozgur; Letai, Anthony

    2008-01-01

    Paclitaxel is a microtubule-targeting antineoplastic drug widely used in human cancers. Even when tumors are initially responsive, progression of disease despite continued taxane therapy is all too common in the treatment of many of the most common epithelial cancers, including breast cancer. However, the mechanisms underlying paclitaxel resistance in cancer cells are not completely understood. Our hypothesis is that changes in the intrinsic (or mitochondrial) cell death pathway controlled by...

  1. Activity of lysosomal and mitochondrial ferments in serum and liver tissue at controlled and treated by leukotitin animals

    International Nuclear Information System (INIS)

    In this chapter author describes the experiments on rats and gives the information on activity of lysosomal and mitochondrial ferments in serum and liver tissue at controlled and treated by leukotitin animals

  2. Improved insulin sensitivity associated with reduced mitochondrial complex IV assembly and activity.

    Science.gov (United States)

    Deepa, Sathyaseelan S; Pulliam, Daniel; Hill, Shauna; Shi, Yun; Walsh, Michael E; Salmon, Adam; Sloane, Lauren; Zhang, Ning; Zeviani, Massimo; Viscomi, Carlo; Musi, Nicolas; Van Remmen, Holly

    2013-04-01

    Mice lacking Surf1, a complex IV assembly protein, have ∼50-70% reduction in cytochrome c oxidase activity in all tissues yet a paradoxical increase in lifespan. Here we report that Surf1(-/-) mice have lower body (15%) and fat (20%) mass, in association with reduced lipid storage, smaller adipocytes, and elevated indicators of fatty acid oxidation in white adipose tissue (WAT) compared with control mice. The respiratory quotient in the Surf1(-/-) mice was significantly lower than in the control animals (0.83-0.93 vs. 0.90-0.98), consistent with enhanced fat utilization in Surf1(-/-) mice. Elevated fat utilization was associated with increased insulin sensitivity measured as insulin-stimulated glucose uptake, as well as an increase in insulin receptor levels (∼2-fold) and glucose transporter type 4 (GLUT4; ∼1.3-fold) levels in WAT in the Surf1(-/-) mice. The expression of peroxisome proliferator-activated receptor γ-coactivator 1-α (PGC-1α) mRNA and protein was up-regulated by 2.5- and 1.9-fold, respectively, in WAT from Surf1(-/-) mice, and the expression of PGC-1α target genes and markers of mitochondrial biogenesis was elevated. Together, these findings point to a novel and unexpected link between reduced mitochondrial complex IV activity, enhanced insulin sensitivity, and increased mitochondrial biogenesis that may contribute to the increased longevity in the Surf1(-/-) mice. PMID:23241310

  3. Heme oxygenase-1 enhances renal mitochondrial transport carriers and cytochrome C oxidase activity in experimental diabetes.

    Science.gov (United States)

    Di Noia, Maria Antonietta; Van Driesche, Sarah; Palmieri, Ferdinando; Yang, Li-Ming; Quan, Shuo; Goodman, Alvin I; Abraham, Nader G

    2006-06-01

    Up-regulation of heme oxygenase (HO-1) by either cobalt protoporphyrin (CoPP) or human gene transfer improves vascular and renal function by several mechanisms, including increases in antioxidant levels and decreases in reactive oxygen species (ROS) in vascular and renal tissue. The purpose of the present study was to determine the effect of HO-1 overexpression on mitochondrial transporters, cytochrome c oxidase, and anti-apoptotic proteins in diabetic rats (streptozotocin, (STZ)-induced type 1 diabetes). Renal mitochondrial carnitine, deoxynucleotide, and ADP/ATP carriers were significantly reduced in diabetic compared with nondiabetic rats (p SnMP), an inhibitor of HO-1 activity, prevented the restoration of MCs in diabetic rats. Human HO-1 cDNA transfer into diabetic rats increased both HO-1 protein and activity, and restored mitochondrial ADP/ATP and deoxynucleotide carriers. The increase in HO-1 by CoPP administration was associated with a significant increase in the phosphorylation of AKT and levels of BcL-XL proteins. These observations in experimental diabetes suggest that the cytoprotective mechanism of HO-1 against oxidative stress involves an increase in the levels of MCs and anti-apoptotic proteins as well as in cytochrome c oxidase activity. PMID:16595661

  4. Alteration In Bones Metabolism In Active Rheumatoid Arthritis

    International Nuclear Information System (INIS)

    The strength and integrity of the human skeleton depends on a delicate equilibrium between bone resorption and bone formation. Osteocalcin (OC) is synthesized by osteoblasts and is considered to be a marker of bone formation and helps in corporating calcium into bone tissue. Rheumatoid arthritis (RA) is an autoimmune inflammatory joint disease characterized by bone complication including bone pain, erosion and osteoporosis. The aim of the present study is to evaluate some factors responsible in bone metabolism termed OC, vitamin D (vit. D), oncostatin M (OSM), ionized calcium and alkaline phosphatase. Fifty pre-menopausal female patients with active RA and twenty healthy controls of the same age were included in the present study. Radioimmunoassay (RIA) was used to estimate serum OC and active vitamin D. The quantitative determination of ionized calcium and alkaline phosphatase were carried out colorimetrically. OSM was measured by ELISA and serum levels of OC and active vitamin D were significantly decreased in RA patients as compared to those of the control group. On the other hand, the levels of serum OSM, ionized calcium and alkaline phosphatase were significantly increased in the RA patients as compared to their healthy control subjects. The results of this study indicated that early investigation and therapy of disturbances of bone metabolism in active RA are necessary for better prognosis and exhibited the importance of OC as a diagnostic tool of alterations of bone metabolism in RA patients.

  5. Mitochondrial Carbonic Anhydrase VA Deficiency Resulting from CA5A Alterations Presents with Hyperammonemia in Early Childhood

    Science.gov (United States)

    van Karnebeek, Clara D.; Sly, William S.; Ross, Colin J.; Salvarinova, Ramona; Yaplito-Lee, Joy; Santra, Saikat; Shyr, Casper; Horvath, Gabriella A.; Eydoux, Patrice; Lehman, Anna M.; Bernard, Virginie; Newlove, Theresa; Ukpeh, Henry; Chakrapani, Anupam; Preece, Mary Anne; Ball, Sarah; Pitt, James; Vallance, Hilary D.; Coulter-Mackie, Marion; Nguyen, Hien; Zhang, Lin-Hua; Bhavsar, Amit P.; Sinclair, Graham; Waheed, Abdul; Wasserman, Wyeth W.; Stockler-Ipsiroglu, Sylvia

    2014-01-01

    Four children in three unrelated families (one consanguineous) presented with lethargy, hyperlactatemia, and hyperammonemia of unexplained origin during the neonatal period and early childhood. We identified and validated three different CA5A alterations, including a homozygous missense mutation (c.697T>C) in two siblings, a homozygous splice site mutation (c.555G>A) leading to skipping of exon 4, and a homozygous 4 kb deletion of exon 6. The deleterious nature of the homozygous mutation c.697T>C (p.Ser233Pro) was demonstrated by reduced enzymatic activity and increased temperature sensitivity. Carbonic anhydrase VA (CA-VA) was absent in liver in the child with the homozygous exon 6 deletion. The metabolite profiles in the affected individuals fit CA-VA deficiency, showing evidence of impaired provision of bicarbonate to the four enzymes that participate in key pathways in intermediary metabolism: carbamoylphosphate synthetase 1 (urea cycle), pyruvate carboxylase (anaplerosis, gluconeogenesis), propionyl-CoA carboxylase, and 3-methylcrotonyl-CoA carboxylase (branched chain amino acids catabolism). In the three children who were administered carglumic acid, hyperammonemia resolved. CA-VA deficiency should therefore be added to urea cycle defects, organic acidurias, and pyruvate carboxylase deficiency as a treatable condition in the differential diagnosis of hyperammonemia in the neonate and young child. PMID:24530203

  6. Activation of human mitochondrial pantothenate kinase 2 by palmitoylcarnitine

    OpenAIRE

    Leonardi, Roberta; Rock, Charles O.; Jackowski, Suzanne; Zhang, Yong-Mei

    2007-01-01

    The human isoform 2 of pantothenate kinase (PanK2) is localized to the mitochondria, and mutations in this protein are associated with a progressive neurodegenerative disorder. PanK2 inhibition by acetyl-CoA is so stringent (IC50 < 1 μM) that it is unclear how the enzyme functions in the presence of intracellular CoA concentrations. Palmitoylcarnitine was discovered to be a potent activator of PanK2 that functions to competitively antagonize acetyl-CoA inhibition. Acetyl-CoA was a competitive...

  7. Activation-dependent mitochondrial translocation of Foxp3 in human hepatocytes.

    Science.gov (United States)

    Rojas, Joselyn; Teran-Angel, Guillermo; Barbosa, Luisa; Peterson, Darrell L; Berrueta, Lisbeth; Salmen, Siham

    2016-05-01

    Foxp3 is considered to be the master regulator for the development and function of regulatory T cells (Treg). Recently Foxp3, has been detected in extra lymphoid tissue, and in hepatocytes and has been associated with hepatocellular carcinoma (HCC), although its role has not been defined. Since it is expected that there is a relationship between protein localization, activity and cellular function, the aim of this study was to explore the subcellular localization of Foxp3 in resting and stimulated human hepatocytes. Foxp3 expression was measured by flow cytometry, subcellular fractioning, and immunofluorescence, and this data was used to track the shuttling of Foxp3 in different subcellular compartments in hepatocytes (HepG2 cell line), stimulated by using the PKC activators (PMA), core and preS1/2 antigen from hepatitis B virus (HBV). Our data shows that besides the nuclear location, mitochondrial translocation was detected after stimulation with PMA and at to a lesser extent, with preS1/2. In addition, Foxp3 is localizes at outer mitochondrial membrane. These results suggest a non-canonical role of Foxp3 in the mitochondrial compartment in human hepatocytes, and opens a new field about their role in liver damages during HBV infection. PMID:27068374

  8. Alteration of biophysical activity of pulmonary surfactant by aluminosilicate nanoparticles.

    Science.gov (United States)

    Kondej, Dorota; Sosnowski, Tomasz R

    2013-02-01

    The influence of five different types of aluminosilicate nanoparticles (NPs) on the dynamic surface activity of model pulmonary surfactant (PS) (Survanta) was studied experimentally using oscillating bubble tensiometry. Bentonite, halloysite and montmorillonite (MM) NPs, which are used as fillers of polymer composites, were characterized regarding the size distribution, morphology and surface area. Particle doses applied in the studies were estimated based on the inhalation rate and duration, taking into account the expected aerosol concentration and deposition efficiency after penetration of NPs into the alveolar region. The results indicate that aluminosilicate NPs at concentrations in the pulmonary liquid above 0.1 mg cm(-3) are capable of promoting alterations of the original dynamic biophysical activity of the PS. This effect is indicated by deviation of the minimum surface tension, stability index and the size of surface tension hysteresis. Such response is dependent on the type of NPs present in the system and is stronger when particle concentration increases. It is suggested that interactions between NPs and the PS must be related to the surfactant adsorption on the suspended particles, while in the case of surface-modified clay NPs the additional washout of surface-active components may be expected. It is speculated that observed changes in surface properties of the surfactant may be associated with undesired health effects following extensive inhalation of aluminosilicate NPs in the workplace. PMID:23363039

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

    Directory of Open Access Journals (Sweden)

    Omar Ortiz-Avila

    2015-01-01

    Full Text Available 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.

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

    Science.gov (United States)

    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. PMID:26180820

  11. Mitochondrial dysfunction and organophosphorus compounds

    International Nuclear Information System (INIS)

    Organophosphorous (OPs) pesticides are the most widely used pesticides in the agriculture and home. However, many acute or chronic poisoning reports about OPs have been published in the recent years. Mitochondria as a site of cellular oxygen consumption and energy production can be a target for OPs poisoning as a non-cholinergic mechanism of toxicity of OPs. In the present review, we have reviewed and criticized all the evidences about the mitochondrial dysfunctions as a mechanism of toxicity of OPs. For this purpose, all biochemical, molecular, and morphological data were retrieved from various studies. Some toxicities of OPs are arisen from dysfunction of mitochondrial oxidative phosphorylation through alteration of complexes I, II, III, IV and V activities and disruption of mitochondrial membrane. Reductions of adenosine triphosphate (ATP) synthesis or induction of its hydrolysis can impair the cellular energy. The OPs disrupt cellular and mitochondrial antioxidant defense, reactive oxygen species generation, and calcium uptake and promote oxidative and genotoxic damage triggering cell death via cytochrome C released from mitochondria and consequent activation of caspases. The mitochondrial dysfunction induced by OPs can be restored by use of antioxidants such as vitamin E and C, alpha-tocopherol, electron donors, and through increasing the cytosolic ATP level. However, to elucidate many aspect of mitochondrial toxicity of Ops, further studies should be performed. - Highlights: • As a non-cholinergic mechanism of toxicity, mitochondria is a target for OPs. • OPs affect action of complexes I, II, III, IV and V in the mitochondria. • OPs reduce mitochondrial ATP. • OPs promote oxidative and genotoxic damage via release of cytochrome C from mitochondria. • OP-induced mitochondrial dysfunction can be restored by increasing the cytosolic ATP

  12. Mitochondrial dysfunction and organophosphorus compounds

    Energy Technology Data Exchange (ETDEWEB)

    Karami-Mohajeri, Somayyeh [Department of Toxicology and Pharmacology, Faculty of Pharmacy, and Pharmaceutical Sciences Research Center, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Department of Toxicology and Pharmacology, Faculty of Pharmacy, and Pharmaceutical Sciences Research Center, Kerman University of Medical Sciences, Kerman (Iran, Islamic Republic of); Abdollahi, Mohammad, E-mail: Mohammad.Abdollahi@UToronto.Ca [Department of Toxicology and Pharmacology, Faculty of Pharmacy, and Pharmaceutical Sciences Research Center, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of)

    2013-07-01

    Organophosphorous (OPs) pesticides are the most widely used pesticides in the agriculture and home. However, many acute or chronic poisoning reports about OPs have been published in the recent years. Mitochondria as a site of cellular oxygen consumption and energy production can be a target for OPs poisoning as a non-cholinergic mechanism of toxicity of OPs. In the present review, we have reviewed and criticized all the evidences about the mitochondrial dysfunctions as a mechanism of toxicity of OPs. For this purpose, all biochemical, molecular, and morphological data were retrieved from various studies. Some toxicities of OPs are arisen from dysfunction of mitochondrial oxidative phosphorylation through alteration of complexes I, II, III, IV and V activities and disruption of mitochondrial membrane. Reductions of adenosine triphosphate (ATP) synthesis or induction of its hydrolysis can impair the cellular energy. The OPs disrupt cellular and mitochondrial antioxidant defense, reactive oxygen species generation, and calcium uptake and promote oxidative and genotoxic damage triggering cell death via cytochrome C released from mitochondria and consequent activation of caspases. The mitochondrial dysfunction induced by OPs can be restored by use of antioxidants such as vitamin E and C, alpha-tocopherol, electron donors, and through increasing the cytosolic ATP level. However, to elucidate many aspect of mitochondrial toxicity of Ops, further studies should be performed. - Highlights: • As a non-cholinergic mechanism of toxicity, mitochondria is a target for OPs. • OPs affect action of complexes I, II, III, IV and V in the mitochondria. • OPs reduce mitochondrial ATP. • OPs promote oxidative and genotoxic damage via release of cytochrome C from mitochondria. • OP-induced mitochondrial dysfunction can be restored by increasing the cytosolic ATP.

  13. Pseudorabies virus infection alters neuronal activity and connectivity in vitro.

    Directory of Open Access Journals (Sweden)

    Kelly M McCarthy

    2009-10-01

    Full Text Available Alpha-herpesviruses, including human herpes simplex virus 1 & 2, varicella zoster virus and the swine pseudorabies virus (PRV, infect the peripheral nervous system of their hosts. Symptoms of infection often include itching, numbness, or pain indicative of altered neurological function. To determine if there is an in vitro electrophysiological correlate to these characteristic in vivo symptoms, we infected cultured rat sympathetic neurons with well-characterized strains of PRV known to produce virulent or attenuated symptoms in animals. Whole-cell patch clamp recordings were made at various times after infection. By 8 hours of infection with virulent PRV, action potential (AP firing rates increased substantially and were accompanied by hyperpolarized resting membrane potentials and spikelet-like events. Coincident with the increase in AP firing rate, adjacent neurons exhibited coupled firing events, first with AP-spikelets and later with near identical resting membrane potentials and AP firing. Small fusion pores between adjacent cell bodies formed early after infection as demonstrated by transfer of the low molecular weight dye, Lucifer Yellow. Later, larger pores formed as demonstrated by transfer of high molecular weight Texas red-dextran conjugates between infected cells. Further evidence for viral-induced fusion pores was obtained by infecting neurons with a viral mutant defective for glycoprotein B, a component of the viral membrane fusion complex. These infected neurons were essentially identical to mock infected neurons: no increased AP firing, no spikelet-like events, and no electrical or dye transfer. Infection with PRV Bartha, an attenuated circuit-tracing strain delayed, but did not eliminate the increased neuronal activity and coupling events. We suggest that formation of fusion pores between infected neurons results in electrical coupling and elevated firing rates, and that these processes may contribute to the altered neural

  14. Mitochondrial Protection and Anti-aging Activity of Astragalus Polysaccharides and Their Potential Mechanism

    Directory of Open Access Journals (Sweden)

    Xiao-Juan Xin

    2012-02-01

    Full Text Available The current study was performed to investigate mitochondrial protection and anti-aging activity of Astragalus polysaccharides (APS and the potential underlying mechanism. Lipid peroxidation of liver and brain mitochondria was induced by Fe2+–Vit C in vitro. Thiobarbituric acid (TBA colorimetry was used to measure the content of thiobarbituric acid reactive substances (TBARS. Mouse liver mitochondrial permeability transition (PT was induced by calcium overload in vitro and spectrophotometry was used to measure it. The scavenging activities of APS on superoxide anion (O2•- and hydroxyl radical (•OH, which were produced by reduced nicotinamide adenine dinucleotide (NADH—N-Methylphenazonium methyl sulfate (PMS and hydrogen peroxide (H2O2–Fe2+ system respectively, were measured by 4-nitrobluetetrazolium chloride (NBT reduction and Fenton reaction colorimetry respectively. The Na2S2O3 titration method was used to measure the scavenging activities of APS on H2O2. APS could inhibit TBARS production, protect mitochondria from PT, and scavenge O2•-, •OH and H2O2 significantly in a concentration-dependent manner respectively. The back of the neck of mice was injected subcutaneously with D-galactose to induce aging at a dose of 100 mg/kg/d for seven weeks. Moreover, the activities of catalase (CAT, surperoxide dismutase (SOD and glutathione peroxidase (GPx and anti-hydroxyl radical which were assayed by using commercial monitoring kits were increased significantly in vivo by APS. According to this research, APS protects mitochondria by scavenging reactive oxygen species (ROS, inhibiting mitochondrial PT and increasing the activities of antioxidases. Therefore, APS has the effect of promoting health.

  15. Effect of low-level laser therapy on the modulation of the mitochondrial activity of macrophages

    Directory of Open Access Journals (Sweden)

    Nadhia H. C. Souza

    2014-08-01

    Full Text Available BACKGROUND: Macrophages play a major role among the inflammatory cells that invade muscle tissue following an injury. Low-level laser therapy (LLLT has long been used in clinical practice to accelerate the muscle repair process. However, little is known regarding its effect on macrophages. OBJECTIVE: This study evaluated the effect of LLLT on the mitochondrial activity (MA of macrophages. METHOD: J774 macrophages were treated with lipopolysaccharide (LPS and interferon - gamma (IFN-γ (activation for 24 h to simulate an inflammatory process, then irradiated with LLLT using two sets of parameters (780 nm; 70 mW; 3 J/cm2 and 660 nm; 15 mW; 7.5 J/cm2. Non-activated/non-irradiated cells composed the control group. MA was evaluated by the cell mitochondrial activity (MTT assay (after 1, 3 and 5 days in three independent experiments. The data were analyzed statistically. RESULTS: After 1 day of culture, activated and 780 nm irradiated macrophages showed lower MA than activated macrophages, but activated and 660 nm irradiated macrophages showed MA similar to activated cells. After 3 days, activated and irradiated (660 nm and 780 nm macrophages showed greater MA than activated macrophages, and after 5 days, the activated and irradiated (660 nm and 780 nm macrophages showed similar MA to the activated macrophages. CONCLUSIONS: These results show that 660 nm and 780 nm LLLT can modulate the cellular activation status of macrophages in inflammation, highlighting the importance of this resource and of the correct determination of its parameters in the repair process of skeletal muscle.

  16. Ablation of PGC-1beta results in defective mitochondrial activity, thermogenesis, hepatic function, and cardiac performance.

    Directory of Open Access Journals (Sweden)

    Christopher J Lelliott

    2006-11-01

    Full Text Available The transcriptional coactivator peroxisome proliferator-activated receptor-gamma coactivator-1beta (PGC-1beta has been implicated in important metabolic processes. A mouse lacking PGC-1beta (PGC1betaKO was generated and phenotyped using physiological, molecular, and bioinformatic approaches. PGC1betaKO mice are generally viable and metabolically healthy. Using systems biology, we identified a general defect in the expression of genes involved in mitochondrial function and, specifically, the electron transport chain. This defect correlated with reduced mitochondrial volume fraction in soleus muscle and heart, but not brown adipose tissue (BAT. Under ambient temperature conditions, PGC-1beta ablation was partially compensated by up-regulation of PGC-1alpha in BAT and white adipose tissue (WAT that lead to increased thermogenesis, reduced body weight, and reduced fat mass. Despite their decreased fat mass, PGC1betaKO mice had hypertrophic adipocytes in WAT. The thermogenic role of PGC-1beta was identified in thermoneutral and cold-adapted conditions by inadequate responses to norepinephrine injection. Furthermore, PGC1betaKO hearts showed a blunted chronotropic response to dobutamine stimulation, and isolated soleus muscle fibres from PGC1betaKO mice have impaired mitochondrial function. Lack of PGC-1beta also impaired hepatic lipid metabolism in response to acute high fat dietary loads, resulting in hepatic steatosis and reduced lipoprotein-associated triglyceride and cholesterol content. Altogether, our data suggest that PGC-1beta plays a general role in controlling basal mitochondrial function and also participates in tissue-specific adaptive responses during metabolic stress.

  17. The HMG-box mitochondrial transcription factor xl-mtTFA binds DNA as a tetramer to activate bidirectional transcription.

    OpenAIRE

    Antoshechkin, I; Bogenhagen, D F; Mastrangelo, I A

    1997-01-01

    The mitochondrial HMG-box transcription factor xl-mtTFA activates bidirectional transcription by binding to a site separating two core promoters in Xenopus laevis mitochondrial DNA (mtDNA). Three independent approaches were used to study the higher order structure of xl-mtTFA binding to this site. First, co-immunoprecipitation of differentially tagged recombinant mtTFA derivatives established that the protein exists as a multimer. Second, in vitro chemical cross-linking experiments provided e...

  18. Involvement of mitochondrial Na+-Ca2+ exchange in intestinal pacemaking activity

    Institute of Scientific and Technical Information of China (English)

    Byung Joo Kim; Jae Yeoul Jun; Insuk So; Ki Whan Kim

    2006-01-01

    AIM: Interstitial cells of Cajal (ICCs) are the pacemaker cells that generate slow waves in the gastrointestinal (GI) tract. We have aimed to investigate the involvement of mitochondrial Na+-Ca2+ exchange in intestinal pacemaking activity in cultured interstitial cells of Cajal.METHODS: Enzymatic digestions were used todissociate ICCs from the small intestine of a mouse. The whole-cell patch-clamp configuration was used to record membrane currents (voltage clamp) and potentials (current clamp) from cultured ICCs.RESULTS: Clonazepam and CGP37157 inhibited the pacemaking activity of ICCs in a dose-dependent manner.Clonazepam from 20 to 60 μmol/L and CGP37157 from 10 to 30 μmol/L effectively inhibited Ca2+ efflux from mitochondria in pacemaking activity of ICCs. The IC50S of clonazepam and CGP37157 were 37.1 and 18.2 μmol/L, respectively. The addition of 20 μmol/L NiCl2 to the internal solution caused a "wax and wane" phenomenon of pacemaking activity of ICCs.CONCLUSION: These results suggest that mitochondrial Na+-Ca2+ exchange has an important role in intestinal pacemaking activity.

  19. Post-exercise cold water immersion does not alter high intensity interval training-induced exercise performance and Hsp72 responses, but enhances mitochondrial markers.

    Science.gov (United States)

    Aguiar, Paula Fernandes; Magalhães, Sílvia Mourão; Fonseca, Ivana Alice Teixeira; da Costa Santos, Vanessa Batista; de Matos, Mariana Aguiar; Peixoto, Marco Fabrício Dias; Nakamura, Fábio Yuzo; Crandall, Craig; Araújo, Hygor Nunes; Silveira, Leonardo Reis; Rocha-Vieira, Etel; de Castro Magalhães, Flávio; Amorim, Fabiano Trigueiro

    2016-09-01

    This study aims to evaluate the effect of regular post-exercise cold water immersion (CWI) on intramuscular markers of cellular stress response and signaling molecules related to mitochondria biogenesis and exercise performance after 4 weeks of high intensity interval training (HIIT). Seventeen healthy subjects were allocated into two groups: control (CON, n = 9) or CWI (n = 8). Each HIIT session consisted of 8-12 cycling exercise stimuli (90-110 % of peak power) for 60 s followed by 75 s of active recovery three times per week, for 4 weeks (12 HIIT sessions). After each HIIT session, the CWI had their lower limbs immersed in cold water (10 °C) for 15 min and the CON recovered at room temperature. Exercise performance was evaluated before and after HIIT by a 15-km cycling time trial. Vastus lateralis biopsies were obtained pre and 72 h post training. Samples were analyzed for heat shock protein 72 kDa (Hsp72), adenosine monophosphate-activated protein kinase (AMPK), and phosphorylated p38 mitogen-activated protein kinase (p-p38 MAPK) assessed by western blot. In addition, the mRNA expression of heat shock factor-1 (HSF-1), peroxisome proliferator-activated receptor gamma coactivator-1α (PGC-1α), nuclear respiratory factor 1 and 2 (NRF1 and 2), mitochondrial transcription factor A (Tfam), calcium calmodulin-dependent protein kinase 2 (CaMK2) and enzymes citrate synthase (CS), carnitine palmitoyltransferase I (CPT1), and pyruvate dehydrogenase kinase (PDK4) were assessed by real-time PCR. Time to complete the 15-km cycling time trial was reduced with training (p  0.05). No differences were observed with training or condition for mRNA expression of PGC-1α (p = 0.31), CPT1 (p = 0.14), CS (p = 0.44), and NRF-2 (p = 0.82). However, HFS-1 (p = 0.007), PDK4 (p = 0.03), and Tfam (p = 0.03) mRNA were higher in CWI. NRF-1 decrease in both groups after training (p = 0.006). CaMK2 decreased with HIIT (p = 0.003) but

  20. Unique fractal evaluation and therapeutic implications of mitochondrial morphology in malignant mesothelioma.

    Science.gov (United States)

    Lennon, Frances E; Cianci, Gianguido C; Kanteti, Rajani; Riehm, Jacob J; Arif, Qudsia; Poroyko, Valeriy A; Lupovitch, Eitan; Vigneswaran, Wickii; Husain, Aliya; Chen, Phetcharat; Liao, James K; Sattler, Martin; Kindler, Hedy L; Salgia, Ravi

    2016-01-01

    Malignant mesothelioma (MM), is an intractable disease with limited therapeutic options and grim survival rates. Altered metabolic and mitochondrial functions are hallmarks of MM and most other cancers. Mitochondria exist as a dynamic network, playing a central role in cellular metabolism. MM cell lines display a spectrum of altered mitochondrial morphologies and function compared to control mesothelial cells. Fractal dimension and lacunarity measurements are a sensitive and objective method to quantify mitochondrial morphology and most importantly are a promising predictor of response to mitochondrial inhibition. Control cells have high fractal dimension and low lacunarity and are relatively insensitive to mitochondrial inhibition. MM cells exhibit a spectrum of sensitivities to mitochondrial inhibitors. Low mitochondrial fractal dimension and high lacunarity correlates with increased sensitivity to the mitochondrial inhibitor metformin. Lacunarity also correlates with sensitivity to Mdivi-1, a mitochondrial fission inhibitor. MM and control cells have similar sensitivities to cisplatin, a chemotherapeutic agent used in the treatment of MM. Neither oxidative phosphorylation nor glycolytic activity, correlated with sensitivity to either metformin or mdivi-1. Our results suggest that mitochondrial inhibition may be an effective and selective therapeutic strategy in mesothelioma, and identifies mitochondrial morphology as a possible predictor of response to targeted mitochondrial inhibition. PMID:27080907

  1. Propofol and magnesium attenuate isoflurane-induced caspase-3 activation via inhibiting mitochondrial permeability transition pore

    Directory of Open Access Journals (Sweden)

    Zhang Yiying

    2012-08-01

    Full Text Available Abstract Background The inhalation anesthetic isoflurane has been shown to open the mitochondrial permeability transition pore (mPTP and induce caspase activation and apoptosis, which may lead to learning and memory impairment. Cyclosporine A, a blocker of mPTP opening might attenuate the isoflurane-induced mPTP opening, lessening its ripple effects. Magnesium and anesthetic propofol are also mPTP blockers. We therefore set out to determine whether propofol and magnesium can attenuate the isoflurane-induced caspase activation and mPTP opening. Methods We investigated the effects of magnesium sulfate (Mg2+, propofol, and isoflurane on the opening of mPTP and caspase activation in H4 human neuroglioma cells stably transfected to express full-length human amyloid precursor protein (APP (H4 APP cells and in six day-old wild-type mice, employing Western blot analysis and flowcytometry. Results Here we show that Mg2+ and propofol attenuated the isoflurane-induced caspase-3 activation in H4-APP cells and mouse brain tissue. Moreover, Mg2+ and propofol, the blockers of mPTP opening, mitigated the isoflurane-induced mPTP opening in the H4-APP cells. Conclusion These data illustrate that Mg2+ and propofol may ameliorate the isoflurane-induced neurotoxicity by inhibiting its mitochondrial dysfunction. Pending further studies, these findings may suggest the use of Mg2+ and propofol in preventing and treating anesthesia neurotoxicity.

  2. Mitochondrial network in glioma's invadopodia displays an activated state both in situ and in vitro: potential functional implications.

    Science.gov (United States)

    Arismendi-Morillo, Gabriel; Hoa, Neil T; Ge, Lisheng; Jadus, Martin R

    2012-12-01

    glioblastoma multiforme cells has been reported [ 3 , 4 ]. Because of the significant impact of invadopodia in oncological events such as cell invasion and matrix degradation, more insight into structural and molecular aspects is needed [ 2 ]. The dynamic assembly of invadopodia is still not well understood [ 2 ], and little is known of the alterations in mitochondrial structure and function that contribute to cell mobility [ 5 ]. This paper describes two prominent structural features of the mitochondrial network present within the glioma´s invadopodia that we have recently observed. We believe these two features (activated mitochondria and smooth ER, along with mitochondria contained within the filopodia) might provide researchers with possible targets for future therapies that can control glioma invasiveness. PMID:23216239

  3. Activity-Based Protein Profiling Reveals Mitochondrial Oxidative Enzyme Impairment and Restoration in Diet-Induced Obese Mice

    Energy Technology Data Exchange (ETDEWEB)

    Sadler, Natalie C.; Angel, Thomas E.; Lewis, Michael P.; Pederson, Leeanna M.; Chauvigne-Hines, Lacie M.; Wiedner, Susan D.; Zink, Erika M.; Smith, Richard D.; Wright, Aaron T.

    2012-10-24

    High-fat diet (HFD) induced obesity and concomitant development of insulin resistance (IR) and type 2 diabetes mellitus have been linked to mitochondrial dysfunction. However, it is not clear whether mitochondrial dysfunction is a direct effect of a HFD or if the mitochondrial function is reduced with increased HFD duration. We hypothesized that the function of mitochondrial oxidative and lipid metabolism functions in skeletal muscle mitochondria for HFD mice are similar or elevated relative to standard diet (SD) mice, thereby IR is neither cause nor consequence of mitochondrial dysfunction. We applied a chemical probe approach to identify functionally reactive ATPases and nucleotide-binding proteins in mitochondria isolated from skeletal muscle of C57Bl/6J mice fed HFD or SD chow for 2-, 8-, or 16-weeks; feeding time points known to induce IR. A total of 293 probe-labeled proteins were identified by mass spectrometry-based proteomics, of which 54 differed in abundance between HFD and SD mice. We found proteins associated with the TCA cycle, oxidative phosphorylation (OXPHOS), and lipid metabolism were altered in function when comparing SD to HFD fed mice at 2-weeks, however by 16-weeks HFD mice had TCA cycle, β-oxidation, and respiratory chain function at levels similar to or higher than SD mice.

  4. BINDING OF THE RESPIRATORY CHAIN INHIBITOR ANTIMYCIN TO THE MITOCHONDRIAL bc1 COMPLEX: A NEW CRYSTAL STRUCTURE REVEALS AN ALTERED INTRAMOLECULAR HYDROGEN-BONDING PATTERN.

    OpenAIRE

    Huang, Li-shar; Cobessi, David; Tung, Eric Y.; Berry, Edward A.

    2005-01-01

    Antimycin A (antimycin), one of the first known and most potent inhibitors of the mitochondrial respiratory chain, binds to the quinone reduction site of the cytochrome bc1 complex. Structure-activity-relationship studies have shown that the N-formylamino-salicyl-amide group is responsible for most of the binding specificity, and suggested that a low pKa for the phenolic OH group and an intramolecular H-bond between that OH and the carbonyl O of the salicylamide linkage are important. Tw...

  5. Cytotoxicity of phenothiazine derivatives associated with mitochondrial dysfunction: A structure-activity investigation

    International Nuclear Information System (INIS)

    Highlights: • Phenothiazines induced cell death in a concentration dependent manner in HTC cells. • Structural requirements that account to phenothiazine cytotoxicity were determined. • Phenothiazines promote immediate morphological changes in cultured liver cells. • Phenothiazine-induced cell death was accompanied of plasma membrane permeabilization. • The dissipation of mitochondrial membrane potential and permeabilization correlated with cytotoxicity. - Abstract: Phenothiazine derivatives are neuroleptic drugs used in the treatment of schizophrenia and anxiety. Several side effects are described for these drugs, including hepatotoxicity, which may be related to their cytotoxic activity. Working with isolated rat liver mitochondria, we previously showed that phenothiazine derivatives induced the mitochondrial permeability transition associated with cytochrome c release. Since the mitochondrial permeabilization process plays a central role in cell death, the aim of this work was to evaluate the effects of five phenothiazine derivatives (chlorpromazine, fluphenazine, thioridazine, trifluoperazine, and triflupromazine) on the viability of hepatoma tissue culture (HTC) cells to establish the structural requirements for cytotoxicity. All phenothiazine derivatives decreased the viability of the HTC cells in a concentration-dependent manner and exhibited different cytotoxic potencies. The EC50 values ranged from 45 to 125 μM, with the piperidinic derivative thioridazine displaying the most cytotoxicity, followed by the piperazinic and aliphatic derivatives. The addition of the phenothiazine derivatives to cell suspensions resulted in significant morphological changes and plasma membrane permeabilization. Octanol/water partition studies revealed that these drugs partitioned preferentially to the apolar phase, even at low pH values (≤4.5). Also, structural and electronic properties were calculated employing density functional theory. Interestingly, the

  6. Mitochondrial Dynamics and Mitochondrial Dysfunction in Diabetes.

    Science.gov (United States)

    Wada, Jun; Nakatsuka, Atsuko

    2016-06-01

    The mitochondria are involved in active and dynamic processes, such as mitochondrial biogenesis, fission, fusion and mitophagy to maintain mitochondrial and cellular functions. In obesity and type 2 diabetes, impaired oxidation, reduced mitochondrial contents, lowered rates of oxidative phosphorylation and excessive reactive oxygen species (ROS) production have been reported. Mitochondrial biogenesis is regulated by various transcription factors such as peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α), peroxisome proliferator-activated receptors (PPARs), estrogen-related receptors (ERRs), and nuclear respiratory factors (NRFs). Mitochondrial fusion is promoted by mitofusin 1 (MFN1), mitofusin 2 (MFN2) and optic atrophy 1 (OPA1), while fission is governed by the recruitment of dynamin-related protein 1 (DRP1) by adaptor proteins such as mitochondrial fission factor (MFF), mitochondrial dynamics proteins of 49 and 51 kDa (MiD49 and MiD51), and fission 1 (FIS1). Phosphatase and tensin homolog (PTEN)-induced putative kinase 1 (PINK1) and PARKIN promote DRP1-dependent mitochondrial fission, and the outer mitochondrial adaptor MiD51 is required in DRP1 recruitment and PARKIN-dependent mitophagy. This review describes the molecular mechanism of mitochondrial dynamics, its abnormality in diabetes and obesity, and pharmaceuticals targeting mitochondrial biogenesis, fission, fusion and mitophagy. PMID:27339203

  7. Increased activities of mitochondrial enzymes in white adipose tissue in trained rats

    DEFF Research Database (Denmark)

    Stallknecht, B; Vinten, J; Ploug, T;

    1991-01-01

    of 8-12 rats were swim trained for 10 wk or served as either sedentary, sham swim-trained, or cold-stressed controls. White adipose tissue was removed, and the activities of the respiratory chain enzyme cytochrome-c oxidase (CCO) and of the enzyme malate dehydrogenase (MDH), which participates...... 0.05). In female rats the CCO activity expressed per milligram protein was increased 4.5-fold in the trained compared with the sedentary control rats (P less than 0.01). Neither cold stress nor sham swim training increased CCO or MDH activities in white adipose tissue (P greater than 0.......05). In conclusion, in rats, intensive endurance training induces an increase in mitochondrial enzyme activities in white adipose tissue as is seen in skeletal muscle....

  8. Magnetic Resonance Imaging of Mitochondrial Dysfunction and Metabolic Activity, Accompanied by Overproduction of Superoxide.

    Science.gov (United States)

    Bakalova, Rumiana; Georgieva, Ekaterina; Ivanova, Donika; Zhelev, Zhivko; Aoki, Ichio; Saga, Tsuneo

    2015-12-16

    This study shows that a mitochondria-penetrating nitroxide probe (mito-TEMPO) allows detection of superoxide and visualization of mitochondrial dysfunction in living cells due to the effect of T1 shortening in MRI. Mitochondrial dysfunction was induced by treatment of cells with rotenone and 2-methoxyestradiol (2-ME/Rot). The MRI measurements were performed on 7T MRI. The 2-ME/Rot-treated cells were characterized by overproduction of superoxide, which was confirmed by a conventional dihydroethidium test. In the presence of mito-TEMPO, the intensity of MRI signal in 2-ME/Rot-treated cells was ∼30-40% higher, in comparison with that in untreated cells or culture media. In model (cell-free) systems, we observed that superoxide, but not hydrogen peroxide, increased the intensity of T1-weighted MRI signal of mito-TEMPO. Moreover, the superoxide restores the T1-weighted MRI contrast of mito-TEMPOH, a noncontrast (diamagnetic) analogue of mito-TEMPO. This was also confirmed by using EPR spectroscopy. The results demonstrate that superoxide radical is involved in the enhancement of T1-weighted MRI contrast in living cells, in the absence and presence of mito-TEMPO. This report gives a direction for discovering new opportunities for functional MRI, for detection of metabolic activity, accompanied by overproduction of superoxide, as well as by disturbance of the balance between superoxide and hydrogen peroxide, a very important approach to clarify the fine molecular mechanisms in the regulation of many pathologies. The visualization of mitochondrial activity in real-time can be crucial to clarify the molecular mechanism of the functional MRI in its commonly accepted definition, as a method for detection of neurovascular coupling. PMID:26367059

  9. Antidiabetic Effect of Salvianolic Acid A on Diabetic Animal Models via AMPK Activation and Mitochondrial Regulation

    Directory of Open Access Journals (Sweden)

    Guifen Qiang

    2015-05-01

    Full Text Available Background/Aims: Diabetes mellitus (DM characterized by hyperglycemia contributes to macrovascular and microvascular complications. Salvianolic acid A (SalA is a polyphenolic compound isolated from the root of Salvia miltiorrhiza Bunge, which is a traditional Chinese medicine widely used to treat cardiovascular diseases. However, little is known about its antidiabetic effect. Our study aimed to investigate the in vivo and in vitro antidiabetic effect of SalA and the underlying mechanisms. Methods: Alloxan-induced type 1 diabetic mice and high-fat diet (HFD and low-dose streptozotocin (STZ-induced type 2 diabetic rats received SalA treatment. Blood glucose, oral glucose tolerance test (OGTT, 24-h food and water intake were monitored. In vitro, glucose consumption and uptake were measured in HepG2 cells and L6 myotubes. Mitochondrial function was detected in hepatic and skeletal muscle mitochondria. AMP-activated protein kinase (AMPK and Akt were analyzed by western blot. Results: In both type 1 and type 2 diabetic animals, SalA lowered fasting blood glucose (FBG and fed blood glucose in dose-dependent manner, as well as reduced 24-h food and water intake. In vitro, SalA caused dose-dependent increase in glucose consumption and enhanced glucose uptake. SalA significantly increased ATP production from 10 min to 12 h in HepG2 cells and L6 myotubes. Interestingly, SalA decreased mitochondrial membrane potential (MMP in HepG2 cells. Furthermore, SalA improved hepatic and skeletal muscle mitochondrial function, increased ATP production, and concurrently decreased MMP. In particularly, SalA activated AMPK phosphorylation through Ca2+/calmodulin-dependent protein kinase kinase β (CaMKKβ/AMPK signaling pathway, independent of liver kinase 1 (LKB1/AMPK pathway. However, SalA didn't show any effect on insulin secretagogue and activation of PI3K/Akt signaling pathway. Conclusion: SalA exhibits the antidiabetic effects in diabetic animal models through

  10. PGC-1α-Dependent Mitochondrial Adaptation Is Necessary to Sustain IL-2-Induced Activities in Human NK Cells.

    Science.gov (United States)

    Miranda, Dante; Jara, Claudia; Ibañez, Jorge; Ahumada, Viviana; Acuña-Castillo, Claudio; Martin, Adrian; Córdova, Alexandra; Montoya, Margarita

    2016-01-01

    Human Natural Killer (NK) cells are a specialized heterogeneous subpopulation of lymphocytes involved in antitumor defense reactions. NK cell effector functions are critically dependent on cytokines and metabolic activity. Among various cytokines modulating NK cell function, interleukin-2 (IL-2) can induce a more potent cytotoxic activity defined as lymphokine activated killer activity (LAK). Our aim was to determine if IL-2 induces changes at the mitochondrial level in NK cells to support the bioenergetic demand for performing this enhanced cytotoxic activity more efficiently. Purified human NK cells were cultured with high IL-2 concentrations to develop LAK activity, which was assessed by the ability of NK cells to lyse NK-resistant Daudi cells. Here we show that, after 72 h of culture of purified human NK cells with enough IL-2 to induce LAK activity, both the mitochondrial mass and the mitochondrial membrane potential increased in a PGC-1α-dependent manner. In addition, oligomycin, an inhibitor of ATP synthase, inhibited IL-2-induced LAK activity at 48 and 72 h of culture. Moreover, the secretion of IFN-γ from NK cells with LAK activity was also partially dependent on PGC-1α expression. These results indicate that PGC-1α plays a crucial role in regulating mitochondrial function involved in the maintenance of LAK activity in human NK cells stimulated with IL-2. PMID:27413259

  11. Phenyl-α-tert-Butyl Nitrone Reverses Mitochondrial Decay in Acute Chagas’ Disease

    OpenAIRE

    Wen, Jian-jun; Bhatia, Vandanajay; Popov, Vsevolod L.; Garg, Nisha Jain

    2006-01-01

    In this study, we investigated the mechanism(s) of mitochondrial functional decline in acute Chagas’ disease. Our data show a substantial decline in respiratory complex activities (39 to 58%) and ATP (38%) content in Trypanosoma cruzi-infected murine hearts compared with normal controls. These metabolic alterations were associated with an approximately fivefold increase in mitochondrial reactive oxygen species production rate, substantial oxidative insult of mitochondrial membranes and respir...

  12. Loss of the SIN3 transcriptional corepressor results in aberrant mitochondrial function

    Directory of Open Access Journals (Sweden)

    Hüttemann Maik

    2010-07-01

    Full Text Available Abstract Background SIN3 is a transcriptional repressor protein known to regulate many genes, including a number of those that encode mitochondrial components. Results By monitoring RNA levels, we find that loss of SIN3 in Drosophila cultured cells results in up-regulation of not only nuclear encoded mitochondrial genes, but also those encoded by the mitochondrial genome. The up-regulation of gene expression is accompanied by a perturbation in ATP levels in SIN3-deficient cells, suggesting that the changes in mitochondrial gene expression result in altered mitochondrial activity. In support of the hypothesis that SIN3 is necessary for normal mitochondrial function, yeast sin3 null mutants exhibit very poor growth on non-fermentable carbon sources and show lower levels of ATP and reduced respiration rates. Conclusions The findings that both yeast and Drosophila SIN3 affect mitochondrial activity suggest an evolutionarily conserved role for SIN3 in the control of cellular energy production.

  13. Mitochondrial Carbonic Anhydrase VA Deficiency Resulting from CA5A Alterations Presents with Hyperammonemia in Early Childhood

    OpenAIRE

    van Karnebeek, Clara D.; Sly, William S.; Ross, Colin J.; Salvarinova, Ramona; Yaplito-Lee, Joy; Santra, Saikat; Shyr, Casper; Horvath, Gabriella A.; Eydoux, Patrice; Lehman, Anna M.; Bernard, Virginie; Newlove, Theresa; Ukpeh, Henry; Chakrapani, Anupam; Preece, Mary Anne

    2014-01-01

    Four children in three unrelated families (one consanguineous) presented with lethargy, hyperlactatemia, and hyperammonemia of unexplained origin during the neonatal period and early childhood. We identified and validated three different CA5A alterations, including a homozygous missense mutation (c.697T>C) in two siblings, a homozygous splice site mutation (c.555G>A) leading to skipping of exon 4, and a homozygous 4 kb deletion of exon 6. The deleterious nature of the homozygous mutation c.69...

  14. Common 4977 bp deletion and novel alterations in mitochondrial DNA in Vietnamese patients with breast cancer.

    Science.gov (United States)

    Dimberg, Jan; Hong, Thai Trinh; Nguyen, Linh Tu Thi; Skarstedt, Marita; Löfgren, Sture; Matussek, Andreas

    2015-01-01

    Mitochondrial DNA (mtDNA) has been proposed to be involved in carcinogenesis and ageing. The mtDNA 4977 bp deletion is one of the most frequently observed mtDNA mutations in human tissues and may play a role in breast cancer (BC). The aim of this study was to investigate the frequency of mtDNA 4977 bp deletion in BC tissue and its association with clinical factors. We determined the presence of the 4977 bp common deletion in cancer and normal paired tissue samples from 106 Vietnamese patients with BC by sequencing PCR products. The mtDNA 4977 bp deletion was significantly more frequent in normal tissue in comparison with paired cancer tissue. Moreover, the incidence of the 4977 bp deletion in BC tissue was significantly higher in patients with estrogen receptor (ER) positive as compared with ER negative BC tissue. Preliminary results showed, in cancerous tissue, a significantly higher incidence of novel deletions in the group of patients with lymph node metastasis in comparison with the patients with no lymph node metastasis. We have found 4977 bp deletion in mtDNA to be a common event in BC and with special reference to ER positive BC. In addition, the novel deletions were shown to be related to lymph node metastasis. Our finding may provide complementary information in prediction of clinical outcome including metastasis, recurrence and survival of patients with BC. PMID:25674508

  15. Mitochondrial targeting of vitamin E succinate enhances its pro-apoptotic and anti-cancer activity via mitochondrial complex

    Czech Academy of Sciences Publication Activity Database

    Dong, L.F.; Jameson, V.J.A.; Tilly, D.; Černý, Jiří; Mahdavian, E.; Marin-Hernandez, A.; Hernandez-Esquivel, L.; Rodriguez-Enriquez, S.; Štursa, Jan; Witting, P.K.; Stantic, B.; Rohlena, Jakub; Truksa, Jaroslav; Klučková, Katarína; Dyason, J.C.; Ledvina, Miroslav; Salvatore, B.A.; Moreno-Sanchez, R.; Coster, M.; Ralph, S.J.; Smith, A.J.; Neužil, Jiří

    2011-01-01

    Roč. 286, č. 5 (2011), s. 3717-3728. ISSN 0021-9258 R&D Projects: GA ČR(CZ) GA204/08/0811; GA ČR(CZ) GAP301/10/1937; GA AV ČR(CZ) IAA500520702; GA AV ČR(CZ) KAN200520703; GA AV ČR(CZ) KJB500970904 Institutional research plan: CEZ:AV0Z50520701; CEZ:AV0Z4055905 Keywords : Apoptosis induction * proximal ubiquinone-binding site of mitochondrial complex II * reactive oxygen species Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.773, year: 2011

  16. p53-mediated activation of the mitochondrial protease HtrA2/Omi prevents cell invasion.

    Science.gov (United States)

    Yamauchi, Shota; Hou, Yan Yan; Guo, Alvin Kunyao; Hirata, Hiroaki; Nakajima, Wataru; Yip, Ai Kia; Yu, Cheng-han; Harada, Ichiro; Chiam, Keng-Hwee; Sawada, Yasuhiro; Tanaka, Nobuyuki; Kawauchi, Keiko

    2014-03-31

    Oncogenic Ras induces cell transformation and promotes an invasive phenotype. The tumor suppressor p53 has a suppressive role in Ras-driven invasion. However, its mechanism remains poorly understood. Here we show that p53 induces activation of the mitochondrial protease high-temperature requirement A2 (HtrA2; also known as Omi) and prevents Ras-driven invasion by modulating the actin cytoskeleton. Oncogenic Ras increases accumulation of p53 in the cytoplasm, which promotes the translocation of p38 mitogen-activated protein kinase (MAPK) into mitochondria and induces phosphorylation of HtrA2/Omi. Concurrently, oncogenic Ras also induces mitochondrial fragmentation, irrespective of p53 expression, causing the release of HtrA2/Omi from mitochondria into the cytosol. Phosphorylated HtrA2/Omi therefore cleaves β-actin and decreases the amount of filamentous actin (F-actin) in the cytosol. This ultimately down-regulates p130 Crk-associated substrate (p130Cas)-mediated lamellipodia formation, countering the invasive phenotype initiated by oncogenic Ras. Our novel findings provide insights into the mechanism by which p53 prevents the malignant progression of transformed cells. PMID:24662565

  17. Induction of mitochondrial biogenesis and respiration is associated with mTOR regulation in hepatocytes of rats treated with the pan-PPAR activator tetradecylthioacetic acid (TTA)

    International Nuclear Information System (INIS)

    Highlights: ► We investigated mechanisms of mitochondrial regulation in rat hepatocytes. ► Tetradecylthioacetic acid (TTA) was employed to activate mitochondrial oxidation. ► Mitochondrial biogenesis and respiration were induced. ► It was confirmed that PPAR target genes were induced. ► The mechanism involved activation mTOR. -- Abstract: The hypolipidemic effect of peroxisome proliferator-activated receptor (PPAR) activators has been explained by increasing mitochondrial fatty acid oxidation, as observed in livers of rats treated with the pan-PPAR activator tetradecylthioacetic acid (TTA). PPAR-activation does, however, not fully explain the metabolic adaptations observed in hepatocytes after treatment with TTA. We therefore characterized the mitochondrial effects, and linked this to signalling by the metabolic sensor, the mammalian target of rapamycin (mTOR). In hepatocytes isolated from TTA-treated rats, the changes in cellular content and morphology were consistent with hypertrophy. This was associated with induction of multiple mitochondrial biomarkers, including mitochondrial DNA, citrate synthase and mRNAs of mitochondrial proteins. Transcription analysis further confirmed activation of PPARα-associated genes, in addition to genes related to mitochondrial biogenesis and function. Analysis of mitochondrial respiration revealed that the capacity of both electron transport and oxidative phosphorylation were increased. These effects coincided with activation of the stress related factor, ERK1/2, and mTOR. The protein level and phosphorylation of the downstream mTOR actors eIF4G and 4E-BP1 were induced. In summary, TTA increases mitochondrial respiration by inducing hypertrophy and mitochondrial biogenesis in rat hepatocytes, via adaptive regulation of PPARs as well as mTOR.

  18. Induction of mitochondrial biogenesis and respiration is associated with mTOR regulation in hepatocytes of rats treated with the pan-PPAR activator tetradecylthioacetic acid (TTA)

    Energy Technology Data Exchange (ETDEWEB)

    Hagland, Hanne R.; Nilsson, Linn I.H. [Department of Biomedicine, University of Bergen (Norway); Burri, Lena [Institute of Medicine, University of Bergen, Haukeland University Hospital (Norway); Nikolaisen, Julie [Department of Biomedicine, University of Bergen (Norway); Berge, Rolf K. [Institute of Medicine, University of Bergen, Haukeland University Hospital (Norway); Department of Heart Disease, Haukeland University Hospital (Norway); Tronstad, Karl J., E-mail: karl.tronstad@biomed.uib.no [Department of Biomedicine, University of Bergen (Norway)

    2013-01-11

    Highlights: Black-Right-Pointing-Pointer We investigated mechanisms of mitochondrial regulation in rat hepatocytes. Black-Right-Pointing-Pointer Tetradecylthioacetic acid (TTA) was employed to activate mitochondrial oxidation. Black-Right-Pointing-Pointer Mitochondrial biogenesis and respiration were induced. Black-Right-Pointing-Pointer It was confirmed that PPAR target genes were induced. Black-Right-Pointing-Pointer The mechanism involved activation mTOR. -- Abstract: The hypolipidemic effect of peroxisome proliferator-activated receptor (PPAR) activators has been explained by increasing mitochondrial fatty acid oxidation, as observed in livers of rats treated with the pan-PPAR activator tetradecylthioacetic acid (TTA). PPAR-activation does, however, not fully explain the metabolic adaptations observed in hepatocytes after treatment with TTA. We therefore characterized the mitochondrial effects, and linked this to signalling by the metabolic sensor, the mammalian target of rapamycin (mTOR). In hepatocytes isolated from TTA-treated rats, the changes in cellular content and morphology were consistent with hypertrophy. This was associated with induction of multiple mitochondrial biomarkers, including mitochondrial DNA, citrate synthase and mRNAs of mitochondrial proteins. Transcription analysis further confirmed activation of PPAR{alpha}-associated genes, in addition to genes related to mitochondrial biogenesis and function. Analysis of mitochondrial respiration revealed that the capacity of both electron transport and oxidative phosphorylation were increased. These effects coincided with activation of the stress related factor, ERK1/2, and mTOR. The protein level and phosphorylation of the downstream mTOR actors eIF4G and 4E-BP1 were induced. In summary, TTA increases mitochondrial respiration by inducing hypertrophy and mitochondrial biogenesis in rat hepatocytes, via adaptive regulation of PPARs as well as mTOR.

  19. Interactions among three proteins that specifically activate translation of the mitochondrial COX3 mRNA in Saccharomyces cerevisiae.

    OpenAIRE

    Brown, N.G.; Costanzo, M. C.; Fox, T D

    1994-01-01

    The PET54, PET122, and PET494 proteins, which are associated with the yeast inner mitochondrial membrane, specifically activate translation of the mitochondrially encoded COX3 mRNA. We used the two-hybrid system to test whether pairs of these proteins, when fused to either the GAL4 DNA-binding or transcriptional activating domain, can physically associate as measured by the expression of the GAL4-dependent reporter, lacZ. PET54 and PET122 interacted in this system, and an amino-terminally tru...

  20. Alteration of swelling clay minerals by acid activation

    NARCIS (Netherlands)

    Steudel, A.; Batenburg, L.F.; Fischer, H.R.; Weidler, P.G.; Emmerich, K.

    2009-01-01

    The bulk material of six dioctahedral and two trioctahedral swellable clay minerals was leached in H2SO4 and HCl at concentrations of 1.0, 5.0 and 10.0 M at 80 °C for several hours. Alteration of the clay mineral structures was dependent on the individual character of each mineral (chemical composit

  1. Binding of the Respiratory Chain Inhibitor Antimycin to theMitochondrial bc1 Complex: A New Crystal Structure Reveals an AlteredIntramolecular Hydrogen-Bonding Pattern

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Li-shar; Cobessi, David; Tung, Eric Y.; Berry, Edward A.

    2005-05-10

    Antimycin A (antimycin), one of the first known and most potent inhibitors of the mitochondrial respiratory chain, binds to the quinone reduction site of the cytochrome bc1 complex.Structure-activity-relationship studies have shown that the N-formylamino-salicyl-amide group is responsible for most of the binding specificity, and suggested that a low pKa for the phenolic OH group and an intramolecular H-bond between that OH and the carbonyl O of the salicylamide linkage are important. Two previous X-ray structures of antimycin bound to vertebrate bc1 complex gave conflicting results. A new structure reported here of the bovine mitochondrial bc1 complex at 2.28Angstrom resolution with antimycin bound, allows us for the first time to reliably describe the binding of antimycin and shows that the intramolecular hydrogen bond described in solution and in the small-molecule structure is replaced by one involving the NH rather than carbonyl O of the amide linkage, with rotation of the amide group relative to the aromatic ring. The phenolic OH and formylamino N form H-bonds with conserved Asp228 of cyt b, and the formylamino O H-bonds via a water molecule to Lys227. A strong density the right size and shape for a diatomic molecule is found between the other side of the dilactone ring and the alpha-A helix.

  2. Sexual hormones: effects on cardiac and mitochondrial activity after ischemia-reperfusion in adult rats. Gender difference.

    Science.gov (United States)

    Pavón, Natalia; Martínez-Abundis, Eduardo; Hernández, Luz; Gallardo-Pérez, Juan Carlos; Alvarez-Delgado, Carolina; Cerbón, Marco; Pérez-Torres, Israel; Aranda, Alberto; Chávez, Edmundo

    2012-10-01

    In this work we studied the influence of sex hormones on heart and mitochondrial functions, from adult castrated female and male, and intact rats. Castration was performed at their third week of life and on the fourth month animals were subjected to heart ischemia and reperfusion. Electrocardiogram and blood pressure recordings were made, cytokines levels were measured, histopathological studies were performed and thiobarbituric acid reactive species were determined. At the mitochondrial level respiratory control, transmembranal potential and calcium management were determined; Western blot of some mitochondrial components was also performed. Alterations in cardiac function were worst in intact males and castrated females as compared with those found in intact females and castrated males, cytokine levels were modulated also by hormonal status. Regarding mitochondria, in those obtained from hearts from castrated females without ischemia-reperfusion, all evaluated parameters were similar to those observed in mitochondria after ischemia-reperfusion. The results show hormonal influences on the heart at functional and mitochondrial levels. PMID:22609314

  3. Endothelial AMPK activation induces mitochondrial biogenesis and stress adaptation via eNOS-dependent mTORC1 signaling.

    Science.gov (United States)

    Li, Chunying; Reif, Michaella M; Craige, Siobhan M; Kant, Shashi; Keaney, John F

    2016-05-01

    Metabolic stress sensors like AMP-activated protein kinase (AMPK) are known to confer stress adaptation and promote longevity in lower organisms. This study demonstrates that activating the metabolic stress sensor AMP-activated protein kinase (AMPK) in endothelial cells helps maintain normal cellular function by promoting mitochondrial biogenesis and stress adaptation. To better define the mechanisms whereby AMPK promotes endothelial stress resistance, we used 5-aminoimidazole-4-carboxamide riboside (AICAR) to chronically activate AMPK and observed stimulation of mitochondrial biogenesis in wild type mouse endothelium, but not in endothelium from endothelial nitric oxide synthase knockout (eNOS-null) mice. Interestingly, AICAR-enhanced mitochondrial biogenesis was blocked by pretreatment with the mammalian target of rapamycin complex 1 (mTORC1) inhibitor, rapamycin. Further, AICAR stimulated mTORC1 as determined by phosphorylation of its known downstream effectors in wild type, but not eNOS-null, endothelial cells. Together these data indicate that eNOS is needed to couple AMPK activation to mTORC1 and thus promote mitochondrial biogenesis and stress adaptation in the endothelium. These data suggest a novel mechanism for mTORC1 activation that is significant for investigations in vascular dysfunction. PMID:26989010

  4. Mitochondrial Dysfunction: Different Routes to Alzheimer’s Disease Therapy

    OpenAIRE

    Pasquale Picone; Domenico Nuzzo; Luca Caruana; Valeria Scafidi; Marta Di Carlo

    2014-01-01

    Mitochondria are dynamic ATP-generating organelle which contribute to many cellular functions including bioenergetics processes, intracellular calcium regulation, alteration of reduction-oxidation potential of cells, free radical scavenging, and activation of caspase mediated cell death. Mitochondrial functions can be negatively affected by amyloid β peptide (Aβ), an important component in Alzheimer's disease (AD) pathogenesis, and Aβ can interact with mitochondria and cause mitochondrial dys...

  5. Accelerated recovery of renal mitochondrial and tubule homeostasis with SIRT1/PGC-1α activation following ischemia–reperfusion injury

    Energy Technology Data Exchange (ETDEWEB)

    Funk, Jason A., E-mail: funkj@musc.edu [Center for Cell Death, Injury, and Regeneration, Department of Drug Discovery and Biomedical Sciences, Medical University of South Carolina, Charleston, SC 29425 (United States); Schnellmann, Rick G., E-mail: schnell@musc.edu [Center for Cell Death, Injury, and Regeneration, Department of Drug Discovery and Biomedical Sciences, Medical University of South Carolina, Charleston, SC 29425 (United States); Ralph H. Johnson VA Medical Center, Charleston, SC 29401 (United States)

    2013-12-01

    Kidney ischemia–reperfusion (I/R) injury elicits cellular injury in the proximal tubule, and mitochondrial dysfunction is a pathological consequence of I/R. Promoting mitochondrial biogenesis (MB) as a repair mechanism after injury may offer a unique strategy to restore both mitochondrial and organ function. Rats subjected to bilateral renal pedicle ligation for 22 min were treated once daily with the SIRT1 activator SRT1720 (5 mg/kg) starting 24 h after reperfusion until 72 h–144 h. SIRT1 expression was elevated in the renal cortex of rats after I/R + vehicle treatment (IRV), but was associated with less nuclear localization. SIRT1 expression was even further augmented and nuclear localization was restored in the kidneys of rats after I/R + SRT1720 treatment (IRS). PGC-1α was elevated at 72 h–144 h in IRV and IRS kidneys; however, SRT1720 treatment induced deacetylation of PGC-1α, a marker of activation. Mitochondrial proteins ATP synthase β, COX I, and NDUFB8, as well as mitochondrial respiration, were diminished 24 h–144 h in IRV rats, but were partially or fully restored in IRS rats. Urinary kidney injury molecule-1 (KIM-1) was persistently elevated in both IRV and IRS rats; however, KIM-1 tissue expression was attenuated in IRS rats. Additionally, sustained loss of Na{sup +},K{sup +}–ATPase expression and basolateral localization and elevated vimentin in IRV rats was normalized in IRS rats, suggesting restoration of a differentiated, polarized tubule epithelium. The results suggest that SRT1720 treatment expedited recovery of mitochondrial protein expression and function by enhancing MB, which was associated with faster proximal tubule repair. Targeting MB may offer unique therapeutic strategy following ischemic injury. - Highlights: • We examined recovery of mitochondrial and renal function after ischemia–reperfusion. • SRT1720 treatment after I/R induced mitochondrial biogenesis via SIRT1/PGC-1α. • Recovery of mitochondrial function was

  6. Accelerated recovery of renal mitochondrial and tubule homeostasis with SIRT1/PGC-1α activation following ischemia–reperfusion injury

    International Nuclear Information System (INIS)

    Kidney ischemia–reperfusion (I/R) injury elicits cellular injury in the proximal tubule, and mitochondrial dysfunction is a pathological consequence of I/R. Promoting mitochondrial biogenesis (MB) as a repair mechanism after injury may offer a unique strategy to restore both mitochondrial and organ function. Rats subjected to bilateral renal pedicle ligation for 22 min were treated once daily with the SIRT1 activator SRT1720 (5 mg/kg) starting 24 h after reperfusion until 72 h–144 h. SIRT1 expression was elevated in the renal cortex of rats after I/R + vehicle treatment (IRV), but was associated with less nuclear localization. SIRT1 expression was even further augmented and nuclear localization was restored in the kidneys of rats after I/R + SRT1720 treatment (IRS). PGC-1α was elevated at 72 h–144 h in IRV and IRS kidneys; however, SRT1720 treatment induced deacetylation of PGC-1α, a marker of activation. Mitochondrial proteins ATP synthase β, COX I, and NDUFB8, as well as mitochondrial respiration, were diminished 24 h–144 h in IRV rats, but were partially or fully restored in IRS rats. Urinary kidney injury molecule-1 (KIM-1) was persistently elevated in both IRV and IRS rats; however, KIM-1 tissue expression was attenuated in IRS rats. Additionally, sustained loss of Na+,K+–ATPase expression and basolateral localization and elevated vimentin in IRV rats was normalized in IRS rats, suggesting restoration of a differentiated, polarized tubule epithelium. The results suggest that SRT1720 treatment expedited recovery of mitochondrial protein expression and function by enhancing MB, which was associated with faster proximal tubule repair. Targeting MB may offer unique therapeutic strategy following ischemic injury. - Highlights: • We examined recovery of mitochondrial and renal function after ischemia–reperfusion. • SRT1720 treatment after I/R induced mitochondrial biogenesis via SIRT1/PGC-1α. • Recovery of mitochondrial function was expedited

  7. Mitochondrial impairment induced by 3-nitropropionic acid is enhanced by endogenous metalloprotease activity inhibition in cultured rat striatal neurons.

    Science.gov (United States)

    de Oca Balderas, Pavel Montes; Ospina, Gabriel Gutiérrez; Del Ángel, Abel Santamaría

    2013-06-24

    Metalloproteases from the metzincin family mediate molecule processing at the cell membrane termed ectodomain shedding (ES). This mechanism enables the generation of intracellular and extracellular fragments from cell membrane molecules that exert additional functions involved in cell processes including cell death, beyond those of full length molecules. Micotoxin 3-nitropropionic acid (3-NP) induces striatal neuronal degeneration in vivo and in vitro through mitochondrial complex II inhibition. In this study, we hypothesized that metalloproteases regulate mitochondrial activity in cultured rat striatal neurons undergoing degeneration. To test this idea, striatal neuronal cultures characterized by NeuN and GAD-67 expression were treated with 3-NP together with the metalloprotease inhibitor GM6001 and their mitochondrial activity was evaluated by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. Our results showed that metalloprotease inhibition potentiated mitochondrial activity impairment induced by 3-NP whereas the inhibitor alone had no effect. These results indicate that metalloproteases regulate and promote mitochondrial functionality in striatal neurons undergoing degeneration induced by 3-NP. Since NMDA receptor is involved in the excitotoxic neuronal death triggered by 3-NP and is known to undergo ES, we analyzed NMDAR subunit NR1 phenotypic distribution by immunofluorescence. 3-NP and GM6001 induced abnormal perinuclear NR1 accumulation that was not observed with 3-NP or GM6001 alone. This observation suggests that metalloproteases are involved in NR1 cellular reorganization induced by 3-NP, and that their inhibition results in abnormal NR1 distribution. Together results indicate that endogenous metalloproteases are activated during striatal neurodegeneration induced by 3-NP eliciting an adaptative or compensatory response that protects mitochondrial functionality. PMID:23643981

  8. High physical activity in young children suggests positive effects by altering autoantigen-induced immune activity.

    Science.gov (United States)

    Carlsson, E; Ludvigsson, J; Huus, K; Faresjö, M

    2016-04-01

    Physical activity in children is associated with several positive health outcomes such as decreased cardiovascular risk factors, improved lung function, enhanced motor skill development, healthier body composition, and also improved defense against inflammatory diseases. We examined how high physical activity vs a sedentary lifestyle in young children influences the immune response with focus on autoimmunity. Peripheral blood mononuclear cells, collected from 55 5-year-old children with either high physical activity (n = 14), average physical activity (n = 27), or low physical activity (n = 14), from the All Babies In Southeast Sweden (ABIS) cohort, were stimulated with antigens (tetanus toxoid and beta-lactoglobulin) and autoantigens (GAD65 , insulin, HSP60, and IA-2). Immune markers (cytokines and chemokines), C-peptide and proinsulin were analyzed. Children with high physical activity showed decreased immune activity toward the autoantigens GAD65 (IL-5, P < 0.05), HSP60 and IA-2 (IL-10, P < 0.05) and also low spontaneous pro-inflammatory immune activity (IL-6, IL-13, IFN-γ, TNF-α, and CCL2 (P < 0.05)) compared with children with an average or low physical activity. High physical activity in young children seems to have positive effects on the immune system by altering autoantigen-induced immune activity. PMID:25892449

  9. Natural Compounds Modulating Mitochondrial Functions

    Directory of Open Access Journals (Sweden)

    Lara Gibellini

    2015-01-01

    Full Text Available Mitochondria are organelles responsible for several crucial cell functions, including respiration, oxidative phosphorylation, and regulation of apoptosis; they are also the main intracellular source of reactive oxygen species (ROS. In the last years, a particular interest has been devoted to studying the effects on mitochondria of natural compounds of vegetal origin, quercetin (Qu, resveratrol (RSV, and curcumin (Cur being the most studied molecules. All these natural compounds modulate mitochondrial functions by inhibiting organelle enzymes or metabolic pathways (such as oxidative phosphorylation, by altering the production of mitochondrial ROS and by modulating the activity of transcription factors which regulate the expression of mitochondrial proteins. While Qu displays both pro- and antioxidant activities, RSV and Cur are strong antioxidant, as they efficiently scavenge mitochondrial ROS and upregulate antioxidant transcriptional programmes in cells. All the three compounds display a proapoptotic activity, mediated by the capability to directly cause the release of cytochrome c from mitochondria or indirectly by upregulating the expression of proapoptotic proteins of Bcl-2 family and downregulating antiapoptotic proteins. Interestingly, these effects are particularly evident on proliferating cancer cells and can have important therapeutic implications.

  10. The mitochondrial fatty acid synthesis (mtFASII) pathway is capable of mediating nuclear-mitochondrial cross talk through the PPAR system of transcriptional activation

    International Nuclear Information System (INIS)

    Highlights: •The function of the mitochondria fatty acid synthesis pathway is partially unknown. •Overexpression of the pathway causes transcriptional activation through PPARs. •Knock down of the pathway attenuates that activation. •The last enzyme in the pathway regulates its own transcription. •Products of the mtFASII pathway are able to drive nuclear transcription. -- Abstract: Mammalian cells contain two fatty acid synthesis pathways, the cytosolic FASI pathway, and the mitochondrial FASII pathway. The selection behind the conservation of the mitochondrial pathway is not completely understood, given the presence of the cytosolic FAS pathway. In this study, we show through heterologous gene reporter systems and PCR-based arrays that overexpression of MECR, the last step in the mtFASII pathway, causes modulation of gene expression through the PPAR pathway. Electromobility shift assays (EMSAs) demonstrate that overexpression of MECR causes increased binding of PPARs to DNA, while cell fractionation and imaging studies show that MECR remains localized to the mitochondria. Interestingly, knock down of the mtFASII pathway lessens the effect of MECR on this transcriptional modulation. Our data are most consistent with MECR-mediated transcriptional activation through products of the mtFASII pathway, although we cannot rule out MECR acting as a coactivator. Further investigation into the physiological relevance of this communication will be necessary to better understand some of the phenotypic consequences of deficits in this pathway observed in animal models and human disease

  11. The mitochondrial fatty acid synthesis (mtFASII) pathway is capable of mediating nuclear-mitochondrial cross talk through the PPAR system of transcriptional activation

    Energy Technology Data Exchange (ETDEWEB)

    Parl, Angelika; Mitchell, Sabrina L.; Clay, Hayley B.; Reiss, Sara; Li, Zhen; Murdock, Deborah G., E-mail: deborah.murdock@vanderbilt.edu

    2013-11-15

    Highlights: •The function of the mitochondria fatty acid synthesis pathway is partially unknown. •Overexpression of the pathway causes transcriptional activation through PPARs. •Knock down of the pathway attenuates that activation. •The last enzyme in the pathway regulates its own transcription. •Products of the mtFASII pathway are able to drive nuclear transcription. -- Abstract: Mammalian cells contain two fatty acid synthesis pathways, the cytosolic FASI pathway, and the mitochondrial FASII pathway. The selection behind the conservation of the mitochondrial pathway is not completely understood, given the presence of the cytosolic FAS pathway. In this study, we show through heterologous gene reporter systems and PCR-based arrays that overexpression of MECR, the last step in the mtFASII pathway, causes modulation of gene expression through the PPAR pathway. Electromobility shift assays (EMSAs) demonstrate that overexpression of MECR causes increased binding of PPARs to DNA, while cell fractionation and imaging studies show that MECR remains localized to the mitochondria. Interestingly, knock down of the mtFASII pathway lessens the effect of MECR on this transcriptional modulation. Our data are most consistent with MECR-mediated transcriptional activation through products of the mtFASII pathway, although we cannot rule out MECR acting as a coactivator. Further investigation into the physiological relevance of this communication will be necessary to better understand some of the phenotypic consequences of deficits in this pathway observed in animal models and human disease.

  12. Strenuous exercise induces mitochondrial damage in skeletal muscle of old mice

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sangho; Kim, Minjung [Department of Physical Education, Hankuk Univrsity of Foreign Studies, Seoul 130-791 (Korea, Republic of); Lim, Wonchung [Department of Sports Medicine, College of Health Science, Cheongju University, Cheongju 363-764 (Korea, Republic of); Kim, Taeyoung [Department of Physical Education, Hankuk Univrsity of Foreign Studies, Seoul 130-791 (Korea, Republic of); Kang, Chounghun, E-mail: kangx119@umn.edu [Department of Physical Education, Hankuk Univrsity of Foreign Studies, Seoul 130-791 (Korea, Republic of); Laboratory of Physiological Hygiene and Exercise Science, School of Kinesiology, University of Minnesota at Twin Cities, Minneapolis, MN 55455 (United States)

    2015-05-29

    Strenuous exercise is known to cause excessive ROS generation and inflammation. However, the mechanisms responsible for the regulation of mitochondrial integrity in the senescent muscle during high-intensity exercise (HE) are not well studied. Here, we show that HE suppresses up-regulation of mitochondrial function despite increase in mitochondrial copy number, following excessive ROS production, proinflammatory cytokines and NFκB activation. Moreover, HE in the old group resulted in the decreasing of both fusion (Mfn2) and fission (Drp1) proteins that may contribute to alteration of mitochondrial morphology. This study suggests that strenuous exercise does not reverse age-related mitochondrial damage and dysfunction by the increased ROS and inflammation. - Highlights: • Effect of exercise on mitochondrial function of aged skeletal muscles was studied. • Strenuous exercise triggered excessive ROS production and inflammatory cytokines. • Strenuous exercise suppressed mitochondrial function in senescent muscle.

  13. Strenuous exercise induces mitochondrial damage in skeletal muscle of old mice

    International Nuclear Information System (INIS)

    Strenuous exercise is known to cause excessive ROS generation and inflammation. However, the mechanisms responsible for the regulation of mitochondrial integrity in the senescent muscle during high-intensity exercise (HE) are not well studied. Here, we show that HE suppresses up-regulation of mitochondrial function despite increase in mitochondrial copy number, following excessive ROS production, proinflammatory cytokines and NFκB activation. Moreover, HE in the old group resulted in the decreasing of both fusion (Mfn2) and fission (Drp1) proteins that may contribute to alteration of mitochondrial morphology. This study suggests that strenuous exercise does not reverse age-related mitochondrial damage and dysfunction by the increased ROS and inflammation. - Highlights: • Effect of exercise on mitochondrial function of aged skeletal muscles was studied. • Strenuous exercise triggered excessive ROS production and inflammatory cytokines. • Strenuous exercise suppressed mitochondrial function in senescent muscle

  14. Modulation of the matrix redox signaling by mitochondrial Ca(2.).

    Science.gov (United States)

    Santo-Domingo, Jaime; Wiederkehr, Andreas; De Marchi, Umberto

    2015-11-26

    Mitochondria sense, shape and integrate signals, and thus function as central players in cellular signal transduction. Ca(2+) waves and redox reactions are two such intracellular signals modulated by mitochondria. Mitochondrial Ca(2+) transport is of utmost physio-pathological relevance with a strong impact on metabolism and cell fate. Despite its importance, the molecular nature of the proteins involved in mitochondrial Ca(2+) transport has been revealed only recently. Mitochondrial Ca(2+) promotes energy metabolism through the activation of matrix dehydrogenases and down-stream stimulation of the respiratory chain. These changes also alter the mitochondrial NAD(P)H/NAD(P)(+) ratio, but at the same time will increase reactive oxygen species (ROS) production. Reducing equivalents and ROS are having opposite effects on the mitochondrial redox state, which are hard to dissect. With the recent development of genetically encoded mitochondrial-targeted redox-sensitive sensors, real-time monitoring of matrix thiol redox dynamics has become possible. The discoveries of the molecular nature of mitochondrial transporters of Ca(2+) combined with the utilization of the novel redox sensors is shedding light on the complex relation between mitochondrial Ca(2+) and redox signals and their impact on cell function. In this review, we describe mitochondrial Ca(2+) handling, focusing on a number of newly identified proteins involved in mitochondrial Ca(2+) uptake and release. We further discuss our recent findings, revealing how mitochondrial Ca(2+) influences the matrix redox state. As a result, mitochondrial Ca(2+) is able to modulate the many mitochondrial redox-regulated processes linked to normal physiology and disease. PMID:26629314

  15. Modulation of the matrix redox signaling by mitochondrial Ca2+

    Institute of Scientific and Technical Information of China (English)

    Jaime; Santo-Domingo; Andreas; Wiederkehr; Umberto; De; Marchi

    2015-01-01

    Mitochondria sense,shape and integrate signals,and thus function as central players in cellular signal transduction. Ca2+ waves and redox reactions are two such intracellular signals modulated by mitochondria. Mitochondrial Ca2+ transport is of utmost physio-pathological relevance with a strong impact on metabolism and cell fate. Despite its importance,the molecular nature of the proteins involvedin mitochondrial Ca2+ transport has been revealed only recently. Mitochondrial Ca2+ promotes energy metabolism through the activation of matrix dehydrogenases and downstream stimulation of the respiratory chain. These changes also alter the mitochondrial NAD(P)H/NAD(P)+ ratio,but at the same time will increase reactive oxygen species(ROS) production. Reducing equivalents and ROS are having opposite effects on the mitochondrial redox state,which are hard to dissect. With the recent development of genetically encoded mitochondrial-targeted redoxsensitive sensors,real-time monitoring of matrix thiol redox dynamics has become possible. The discoveries of the molecular nature of mitochondrial transporters of Ca2+ combined with the utilization of the novel redox sensors is shedding light on the complex relation between mitochondrial Ca2+ and redox signals and their impact on cell function. In this review,we describe mitochondrial Ca2+ handling,focusing on a number of newly identified proteins involved in mitochondrial Ca2+ uptake and release. We further discuss our recent findings,revealing how mitochondrial Ca2+ influences the matrix redox state. As a result,mitochondrial Ca2+ is able to modulate the many mitochondrial redox-regulated processes linked to normal physiology and disease.

  16. Hyperglycemia decreases mitochondrial function: The regulatory role of mitochondrial biogenesis

    International Nuclear Information System (INIS)

    Increased generation of reactive oxygen species (ROS) is implicated in 'glucose toxicity' in diabetes. However, little is known about the action of glucose on the expression of transcription factors in hepatocytes, especially those involved in mitochondrial DNA (mtDNA) replication and transcription. Since mitochondrial functional capacity is dynamically regulated, we hypothesized that stressful conditions of hyperglycemia induce adaptations in the transcriptional control of cellular energy metabolism, including inhibition of mitochondrial biogenesis and oxidative metabolism. Cell viability, mitochondrial respiration, ROS generation and oxidized proteins were determined in HepG2 cells cultured in the presence of either 5.5 mM (control) or 30 mM glucose (high glucose) for 48 h, 96 h and 7 days. Additionally, mtDNA abundance, plasminogen activator inhibitor-1 (PAI-1), mitochondrial transcription factor A (TFAM) and nuclear respiratory factor-1 (NRF-1) transcripts were evaluated by real time PCR. High glucose induced a progressive increase in ROS generation and accumulation of oxidized proteins, with no changes in cell viability. Increased expression of PAI-1 was observed as early as 96 h of exposure to high glucose. After 7 days in hyperglycemia, HepG2 cells exhibited inhibited uncoupled respiration and decreased MitoTracker Red fluorescence associated with a 25% decrease in mtDNA and 16% decrease in TFAM transcripts. These results indicate that glucose may regulate mtDNA copy number by modulating the transcriptional activity of TFAM in response to hyperglycemia-induced ROS production. The decrease of mtDNA content and inhibition of mitochondrial function may be pathogenic hallmarks in the altered metabolic status associated with diabetes

  17. Synthesis of (2-[11C]Methoxy)rotenone, a marker of mitochondrial complex I activity

    International Nuclear Information System (INIS)

    Recent studies suggest that defects in the function of the complexes of the electron transport chain might be involved in the pathology of neurological diseases such as mitochondrial encephalopathies, Parkinson's Huntington's and Alzheimer's disease. Rotenone is a potent reversible competitive inhibitor of complex I (NADH-CoQ reductase). To study the possible involvement of complex I in such diseases, we synthesized (2-[11C]methoxy)rotenone by [11C]alkylation of 2-O-desmethyl rotenone methyl enol ether followed by hydrolysis of the enol ether to the ketone using aqueous trifluoroacetic acid. (2-[11C]Methoxy)rotenone was purified by high pressure liquid chromatography (silica gel) and was obtained in 7-10% yields decay corrected to end of bombardment in synthesis times typically shorter than 48 min. Radiochemical purities were over 95% and specific activities averaged 1000 Ci/mmol at end of synthesis

  18. Chronic hyperammonemia alters the circadian rhythms of corticosteroid hormone levels and of motor activity in rats.

    Science.gov (United States)

    Ahabrach, Hanan; Piedrafita, Blanca; Ayad, Abdelmalik; El Mlili, Nisrin; Errami, Mohammed; Felipo, Vicente; Llansola, Marta

    2010-05-15

    Patients with liver cirrhosis may present hepatic encephalopathy with a wide range of neurological disturbances and alterations in sleep quality and in the sleep-wake circadian rhythm. Hyperammonemia is a main contributor to the neurological alterations in hepatic encephalopathy. We have assessed, in an animal model of chronic hyperammonemia without liver failure, the effects of hyperammonemia per se on the circadian rhythms of motor activity, temperature, and plasma levels of adrenal corticosteroid hormones. Chronic hyperammonemia alters the circadian rhythms of locomotor activity and of cortisol and corticosterone levels in blood. Different types of motor activity are affected differentially. Hyperammonemia significantly alters the rhythm of spontaneous ambulatory activity, reducing strongly ambulatory counts and slightly average velocity during the night (the active phase) but not during the day, resulting in altered circadian rhythms. In contrast, hyperammonemia did not affect wheel running at all, indicating that it affects spontaneous but not voluntary activity. Vertical activity was affected only very slightly, indicating that hyperammonemia does not induce anxiety. Hyperammonemia abolished completely the circadian rhythm of corticosteroid hormones in plasma, completely eliminating the peaks of cortisol and corticosterone present in control rats at the start of the dark period. The data reported show that chronic hyperammonemia, similar to that present in patients with liver cirrhosis, alters the circadian rhythms of corticosteroid hormones and of motor activity. This suggests that hyperammonemia would be a relevant contributor to the alterations in corticosteroid hormones and in circadian rhythms in patients with liver cirrhosis. PMID:19998493

  19. The Mitochondrial Complex I Activity Is Reduced in Cells with Impaired Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) Function

    OpenAIRE

    Valdivieso, Angel G.; Clauzure, Mariángeles; Marín, María C.; Taminelli, Guillermo L.; Massip Copiz, María M.; Sánchez, Francisco; Schulman, Gustavo; Teiber, María L.; Santa-Coloma, Tomás A.

    2012-01-01

    Cystic fibrosis (CF) is a frequent and lethal autosomal recessive disease. It results from different possible mutations in the CFTR gene, which encodes the CFTR chloride channel. We have previously studied the differential expression of genes in CF and CF corrected cell lines, and found a reduced expression of MTND4 in CF cells. MTND4 is a mitochondrial gene encoding the MTND4 subunit of the mitochondrial Complex I (mCx-I). Since this subunit is essential for the assembly and activity of mCx-...

  20. Cobalt substituted thiosemicarbazone metal complex induced apoptosis in cancer cells via activation of mitochondrial pathway

    International Nuclear Information System (INIS)

    Thiosemicarbazone (TSC) and their transition metal complexes are broad class of biologically active small molecules and present a great variety of biological activity ranging from antitumour, fungicide, bacteriocide, anti inflammatory and antiviral activities. These characteristics render the whole class of compounds very interesting. In the present study, we sought to examine cytotoxic activity of thiosemicarbazone cobalt complex on various cancer cell lines along with the possible mechanism through which the compound induce apoptosis in these cell lines. Cytotoxicity of TSC cobalt complex was studied by performing standard MTT drug sensitivity assay and determining its IC50 value on various leukemic and solid cancer cell lines like HL-60, MOLT-4, K-562 and COLO-205. Cellular damage upon the treatment of test molecule was analyzed by conducting LDH release assay. DNA fragmentation and morphology of apoptotic cells were assessed respectively by performing ladder assay and acridine orange/ethidium bromide staining. Role of mitochondria in the induction of cell death was studied by measuring mitochondrial membrane potential (ΔΨm) using JC-1 probe. The cytotoxicity studies confirms that TSC cobalt complex is having potent anticancer activity on HL-60, K-562, MOLT-4 and COLO-205 cell lines with the IC50 value in the range 0.225-29.00 μM. Dose dependent increase in the LDH release into the surrounding media depicts the cell membrane disintegrity. DNA fragmentation on treated cells revealed the cell death, which is commonly associated with apoptosis. Fluorescence microscopic imaging of treated cells confirms that the mode of cell death was through apoptosis. Loss of the ΔΨm in treated cells explicates the involvement of mitochondria in the cell death induction. Further increase in caspase-3 activity upon treatment corroborates that molecule induces apoptosis. Taken together, this exploratory study revealed that TSC cobalt complex possesses potent cytotoxic and

  1. Nrf2 activation in the treatment of neurodegenerative diseases: a focus on its role in mitochondrial bioenergetics and function.

    Science.gov (United States)

    Esteras, Noemí; Dinkova-Kostova, Albena T; Abramov, Andrey Y

    2016-05-01

    The nuclear factor erythroid-derived 2 (NF-E2)-related factor 2 (Nrf2) is a transcription factor well-known for its function in controlling the basal and inducible expression of a variety of antioxidant and detoxifying enzymes. As part of its cytoprotective activity, increasing evidence supports its role in metabolism and mitochondrial bioenergetics and function. Neurodegenerative diseases are excellent candidates for Nrf2-targeted treatments. Most neurodegenerative conditions such as Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, frontotemporal dementia and Friedreich's ataxia are characterized by oxidative stress, misfolded protein aggregates, and chronic inflammation, the common targets of Nrf2 therapeutic strategies. Together with them, mitochondrial dysfunction is implicated in the pathogenesis of most neurodegenerative disorders. The recently recognized ability of Nrf2 to regulate intermediary metabolism and mitochondrial function makes Nrf2 activation an attractive and comprehensive strategy for the treatment of neurodegenerative disorders. This review aims to focus on the potential therapeutic role of Nrf2 activation in neurodegeneration, with special emphasis on mitochondrial bioenergetics and function, metabolism and the role of transporters, all of which collectively contribute to the cytoprotective activity of this transcription factor. PMID:26812787

  2. Structural basis for S-adenosylmethionine binding and methyltransferase activity by mitochondrial transcription factor B1

    OpenAIRE

    Guja, Kip E.; Venkataraman, Krithika; Yakubovskaya, Elena; Hui SHI; Mejia, Edison; Hambardjieva, Elena; Karzai, A. Wali; Garcia-Diaz, Miguel

    2013-01-01

    Eukaryotic transcription factor B (TFB) proteins are homologous to KsgA/Dim1 ribosomal RNA (rRNA) methyltransferases. The mammalian TFB1, mitochondrial (TFB1M) factor is an essential protein necessary for mitochondrial gene expression. TFB1M mediates an rRNA modification in the small ribosomal subunit and thus plays a role analogous to KsgA/Dim1 proteins. This modification has been linked to mitochondrial dysfunctions leading to maternally inherited deafness, aminoglycoside sensitivity and di...

  3. Age-related activation of mitochondrial caspase-independent apoptotic signaling in rat gastrocnemius muscle

    OpenAIRE

    Marzetti, Emanuele; Wohlgemuth, Stephanie Eva; Lees, Hazel Anne; Chung, Hae-young; Giovannini, Silvia; Leeuwenburgh, Christiaan

    2008-01-01

    Mitochondria-mediated apoptosis represents a central process driving age-related muscle loss. However, the temporal relation between mitochondrial apoptotic signaling and sarcopenia as well as the regulation of release of pro-apoptotic factors from the mitochondria has not been elucidated. In this study, we investigated mitochondrial apoptotic signaling in skeletal muscle of rats across a wide age range. We also investigated whether mitochondrial-driven apoptosis was accompanied by changes in...

  4. PINK1 loss-of-function mutations affect mitochondrial complex I activity via NdufA10 ubiquinone uncoupling.

    Science.gov (United States)

    Morais, Vanessa A; Haddad, Dominik; Craessaerts, Katleen; De Bock, Pieter-Jan; Swerts, Jef; Vilain, Sven; Aerts, Liesbeth; Overbergh, Lut; Grünewald, Anne; Seibler, Philip; Klein, Christine; Gevaert, Kris; Verstreken, Patrik; De Strooper, Bart

    2014-04-11

    Under resting conditions, Pink1 knockout cells and cells derived from patients with PINK1 mutations display a loss of mitochondrial complex I reductive activity, causing a decrease in the mitochondrial membrane potential. Analyzing the phosphoproteome of complex I in liver and brain from Pink1(-/-) mice, we found specific loss of phosphorylation of serine-250 in complex I subunit NdufA10. Phosphorylation of serine-250 was needed for ubiquinone reduction by complex I. Phosphomimetic NdufA10 reversed Pink1 deficits in mouse knockout cells and rescued mitochondrial depolarization and synaptic transmission defects in pink(B9)-null mutant Drosophila. Complex I deficits and adenosine triphosphate synthesis were also rescued in cells derived from PINK1 patients. Thus, this evolutionary conserved pathway may contribute to the pathogenic cascade that eventually leads to Parkinson's disease in patients with PINK1 mutations. PMID:24652937

  5. Glutamate excitotoxicity and Ca(2+)-regulation of respiration: Role of the Ca(2+) activated mitochondrial transporters (CaMCs).

    Science.gov (United States)

    Rueda, Carlos B; Llorente-Folch, Irene; Traba, Javier; Amigo, Ignacio; Gonzalez-Sanchez, Paloma; Contreras, Laura; Juaristi, Inés; Martinez-Valero, Paula; Pardo, Beatriz; Del Arco, Araceli; Satrustegui, Jorgina

    2016-08-01

    Glutamate elicits Ca(2+) signals and workloads that regulate neuronal fate both in physiological and pathological circumstances. Oxidative phosphorylation is required in order to respond to the metabolic challenge caused by glutamate. In response to physiological glutamate signals, cytosolic Ca(2+) activates respiration by stimulation of the NADH malate-aspartate shuttle through Ca(2+)-binding to the mitochondrial aspartate/glutamate carrier (Aralar/AGC1/Slc25a12), and by stimulation of adenine nucleotide uptake through Ca(2+) binding to the mitochondrial ATP-Mg/Pi carrier (SCaMC-3/Slc25a23). In addition, after Ca(2+) entry into the matrix through the mitochondrial Ca(2+) uniporter (MCU), it activates mitochondrial dehydrogenases. In response to pathological glutamate stimulation during excitotoxicity, Ca(2+) overload, reactive oxygen species (ROS), mitochondrial dysfunction and delayed Ca(2+) deregulation (DCD) lead to neuronal death. Glutamate-induced respiratory stimulation is rapidly inactivated through a mechanism involving Poly (ADP-ribose) Polymerase-1 (PARP-1) activation, consumption of cytosolic NAD(+), a decrease in matrix ATP and restricted substrate supply. Glutamate-induced Ca(2+)-activation of SCaMC-3 imports adenine nucleotides into mitochondria, counteracting the depletion of matrix ATP and the impaired respiration, while Aralar-dependent lactate metabolism prevents substrate exhaustion. A second mechanism induced by excitotoxic glutamate is permeability transition pore (PTP) opening, which critically depends on ROS production and matrix Ca(2+) entry through the MCU. By increasing matrix content of adenine nucleotides, SCaMC-3 activity protects against glutamate-induced PTP opening and lowers matrix free Ca(2+), resulting in protracted appearance of DCD and protection against excitotoxicity in vitro and in vivo, while the lack of lactate protection during in vivo excitotoxicity explains increased vulnerability to kainite-induced toxicity in Aralar

  6. Dynamin-related Protein 1 Inhibition Mitigates Bisphenol A-mediated Alterations in Mitochondrial Dynamics and Neural Stem Cell Proliferation and Differentiation.

    Science.gov (United States)

    Agarwal, Swati; Yadav, Anuradha; Tiwari, Shashi Kant; Seth, Brashket; Chauhan, Lalit Kumar Singh; Khare, Puneet; Ray, Ratan Singh; Chaturvedi, Rajnish Kumar

    2016-07-29

    The regulatory dynamics of mitochondria comprises well orchestrated distribution and mitochondrial turnover to maintain the mitochondrial circuitry and homeostasis inside the cells. Several pieces of evidence suggested impaired mitochondrial dynamics and its association with the pathogenesis of neurodegenerative disorders. We found that chronic exposure of synthetic xenoestrogen bisphenol A (BPA), a component of consumer plastic products, impaired autophagy-mediated mitochondrial turnover, leading to increased oxidative stress, mitochondrial fragmentation, and apoptosis in hippocampal neural stem cells (NSCs). It also inhibited hippocampal derived NSC proliferation and differentiation, as evident by the decreased number of BrdU- and β-III tubulin-positive cells. All these effects were reversed by the inhibition of oxidative stress using N-acetyl cysteine. BPA up-regulated the levels of Drp-1 (dynamin-related protein 1) and enhanced its mitochondrial translocation, with no effect on Fis-1, Mfn-1, Mfn-2, and Opa-1 in vitro and in the hippocampus. Moreover, transmission electron microscopy studies suggested increased mitochondrial fission and accumulation of fragmented mitochondria and decreased elongated mitochondria in the hippocampus of the rat brain. Impaired mitochondrial dynamics by BPA resulted in increased reactive oxygen species and malondialdehyde levels, disruption of mitochondrial membrane potential, and ATP decline. Pharmacological (Mdivi-1) and genetic (Drp-1siRNA) inhibition of Drp-1 reversed BPA-induced mitochondrial dysfunctions, fragmentation, and apoptosis. Interestingly, BPA-mediated inhibitory effects on NSC proliferation and neuronal differentiations were also mitigated by Drp-1 inhibition. On the other hand, Drp-1 inhibition blocked BPA-mediated Drp-1 translocation, leading to decreased apoptosis of NSC. Overall, our studies implicate Drp-1 as a potential therapeutic target against BPA-mediated impaired mitochondrial dynamics and

  7. Mitochondrial reactive oxygen species-mediated NLRP3 inflammasome activation contributes to aldosterone-induced renal tubular cells injury.

    Science.gov (United States)

    Ding, Wei; Guo, Honglei; Xu, Chengyan; Wang, Bin; Zhang, Minmin; Ding, Feng

    2016-04-01

    Aldosterone (Aldo) is an independent risk factor for chronic kidney disease (CKD), and although Aldo directly induces renal tubular cell injury, the underlying mechanisms remain unclear. NLRP3 inflammasome and mitochondrial reactive oxygen species (ROS) have recently been implicated in various kinds of CKD. The present study hypothesized that mitochondrial ROS and NLRP3 inflammasome mediated Aldo-induced tubular cell injury. The NLRP3 inflammasome is induced by Aldo in a dose- and time-dependent manner, as evidenced by increased NLRP3, ASC, caspase-1, and downstream cytokines, such as interleukin (IL)-1β and IL-18. The activation of the NLRP3 inflammasome was significantly prevented by the selective mineralocorticoid receptor (MR) antagonist eplerenone (EPL) (P < 0.01). Mice harboring genetic knock-out of NLRP3 (NLRP3(-/-)) showed decreased maturation of renal IL-1β and IL-18, reduced renal tubular apoptosis, and improved renal epithelial cell phenotypic alternation, and attenuated renal function in response to Aldo-infusion. In addition, mitochondrial ROS was also increased in Aldo-stimulated HK-2 cells, as assessed by MitoSOXTM red reagent. Mito-Tempo, the mitochondria-targeted antioxidant, significantly decreased HK-2 cell apoptosis, oxidative stress, and the activation of NLRP3 inflammasome. We conclude that Aldo induces renal tubular cell injury via MR dependent, mitochondrial ROS-mediated NLRP3 inflammasome activation. PMID:27014913

  8. Mitochondrial reactive oxygen species-mediated NLRP3 inflammasome activation contributes to aldosterone-induced renal tubular cells injury

    Science.gov (United States)

    Ding, Wei; Guo, Honglei; Xu, Chengyan; Wang, Bin; Zhang, Minmin; Ding, Feng

    2016-01-01

    Aldosterone (Aldo) is an independent risk factor for chronic kidney disease (CKD), and although Aldo directly induces renal tubular cell injury, the underlying mechanisms remain unclear. NLRP3 inflammasome and mitochondrial reactive oxygen species (ROS) have recently been implicated in various kinds of CKD. The present study hypothesized that mitochondrial ROS and NLRP3 inflammasome mediated Aldo–induced tubular cell injury. The NLRP3 inflammasome is induced by Aldo in a dose- and time-dependent manner, as evidenced by increased NLRP3, ASC, caspase-1, and downstream cytokines, such as interleukin (IL)-1β and IL-18. The activation of the NLRP3 inflammasome was significantly prevented by the selective mineralocorticoid receptor (MR) antagonist eplerenone (EPL) (P < 0.01). Mice harboring genetic knock-out of NLRP3 (NLRP3−/−) showed decreased maturation of renal IL-1β and IL-18, reduced renal tubular apoptosis, and improved renal epithelial cell phenotypic alternation, and attenuated renal function in response to Aldo-infusion. In addition, mitochondrial ROS was also increased in Aldo-stimulated HK-2 cells, as assessed by MitoSOXTM red reagent. Mito-Tempo, the mitochondria-targeted antioxidant, significantly decreased HK-2 cell apoptosis, oxidative stress, and the activation of NLRP3 inflammasome. We conclude that Aldo induces renal tubular cell injury via MR dependent, mitochondrial ROS-mediated NLRP3 inflammasome activation. PMID:27014913

  9. Impaired coactivator activity of the Gly482 variant of peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α) on mitochondrial transcription factor A (Tfam) promoter

    International Nuclear Information System (INIS)

    Mitochondrial dysfunction may cause diabetes or insulin resistance. Peroxisome proliferation-activated receptor-γ (PPAR-γ) coactivator-1 α (PGC-1α) increases mitochondrial transcription factor A (Tfam) resulting in mitochondrial DNA content increase. An association between a single nucleotide polymorphism (SNP), G1444A(Gly482Ser), of PGC-1α coding region and insulin resistance has been reported in some ethnic groups. In this study, we investigated whether a change of glycine to serine at codon 482 of PGC-1α affected the Tfam promoter activity. The cDNA of PGC-1α variant bearing either glycine or serine at 482 codon was transfected into Chang human hepatocyte cells. The PGC-1α protein bearing glycine had impaired coactivator activity on Tfam promoter-mediated luciferase. We analyzed the PGC-1α genotype G1444A and mitochondrial DNA (mtDNA) copy number from 229 Korean leukocyte genomic DNAs. Subjects with Gly/Gly had a 20% lower amount of peripheral blood mtDNA than did subjects with Gly/Ser and Ser/Ser (p < 0.05). No correlation was observed between diabetic parameters and PGC-1α genotypes in Koreans. These results suggest that PGC-1α variants with Gly/Gly at 482nd amino acid may impair the Tfam transcription, a regulatory function of mitochondrial biogenesis, resulting in dysfunctional mtDNA replication

  10. Molecular changes in mitochondrial respiratory activity and metabolic enzyme activity in muscle of four pig breeds with distinct metabolic types.

    Science.gov (United States)

    Liu, Xuan; Trakooljul, Nares; Muráni, Eduard; Krischek, Carsten; Schellander, Karl; Wicke, Michael; Wimmers, Klaus; Ponsuksili, Siriluck

    2016-02-01

    Skeletal muscles are metabolically active and have market value in meat-producing farm animals. A better understanding of biological pathways affecting energy metabolism in skeletal muscle could advance the science of skeletal muscle. In this study, comparative pathway-focused gene expression profiling in conjunction with muscle fiber typing were analyzed in skeletal muscles from Duroc, Pietrain, and Duroc-Pietrain crossbred pigs. Each breed type displayed a distinct muscle fiber-type composition. Mitochondrial respiratory activity and glycolytic and oxidative enzyme activities were comparable among genotypes, except for significantly lower complex I activity in Pietrain pigs homozygous-positive for malignant hyperthermia syndrome. At the transcriptional level, lactate dehydrogenase B showed breed specificity, with significantly lower expression in Pietrain pigs homozygous-positive for malignant hyperthermia syndrome. A similar mRNA expression pattern was shown for several subunits of oxidative phosphorylation complexes, including complex I, complex II, complex IV, and ATP synthase. Significant correlations were observed between mRNA expression of genes in focused pathways and enzyme activities in a breed-dependent manner. Moreover, expression patterns of pathway-focused genes were well correlated with muscle fiber-type composition. These results stress the importance of regulation of transcriptional rate of genes related to oxidative and glycolytic pathways in the metabolic capacity of muscle fibers. Overall, the results further the breed-specific understanding of the molecular basis of metabolic enzyme activities, which directly impact meat quality. PMID:26759028

  11. Role of mitochondrial NADH kinase and NADPH supply in the respiratory chain activity of Saccharomyces cerevisiae

    Institute of Scientific and Technical Information of China (English)

    Feng Shi; Zhijun Li; Mingdi Sun; Yongfu Li

    2011-01-01

    In Saccharomyces cerevisiae,the mitochondrial nicotinamide adenine dinucleotide hydride kinase Pos5p is required for a variety of essential cellular pathways,most importantly respiration.The Pos5p knockout strain pos5Δ grows poorly in non-fermentable media.A potential relationship between this respiratory deficiency and the ability of the cells to supply nicotinamide adenine dinucleotide phosphate (NADPH) was examined by analyzing the respiratory chain activity of pos5A and two NADP+-specific dehydrogenase mutants, idp1Δ and zwf1Δ.All of the respiratory chain complexes of pos5Δ exhibited poor relative activity of <26% at the middle-log phase and 62% at the stationary phase.The respiratory chain activity levels of idp1Δ and zwf1Δ also reduced to 22%-37% and 28%-84% at the middle-log phase,and 73%-81% and 67%-88% at the stationary phase,not as robustly as those ofpos5Δ.The double-mutant idp1pos5Δexhibited even lower activities of <20% at the middle-log phase,but zwf1pos5Δ showed similar activities with pos5Δ.The complemented strain POS5/pos5Δ exhibited 1.05- to 3-fold higher activities than pos5Δ.These data showed that Pos5p contributes to the maintenance of respiratory chain complex activities,with other NADPH sources,such as ldp1p and Zwf1p,making a smaller contribution.These contributions were partly related to the ability of the cells to supply NADPH,especially in the mitochondria.

  12. Altered Erythrocyte Glycolytic Enzyme Activities in Type-II Diabetes.

    Science.gov (United States)

    Mali, Aniket V; Bhise, Sunita S; Hegde, Mahabaleshwar V; Katyare, Surendra S

    2016-07-01

    The activity of enzymes of glycolysis has been studied in erythrocytes from type-II diabetic patients in comparison with control. RBC lysate was the source of enzymes. In the diabetics the hexokinase (HK) activity increased 50 % while activities of phosphoglucoisomerase (PGI), phosphofructokinase (PFK) and aldolase (ALD) decreased by 37, 75 and 64 % respectively but were still several folds higher than that of HK. Hence, it is possible that in the diabetic erythrocytes the process of glycolysis could proceed in an unimpaired or in fact may be augmented due to increased levels of G6P. The lactate dehydrogenase (LDH) activity was comparatively high in both the groups; the diabetic group showed 85 % increase. In control group the HK, PFK and ALD activities showed strong positive correlation with blood sugar level while PGI activity did not show any correlation. In the diabetic group only PFK activity showed positive correlation. The LDH activity only in the control group showed positive correlation with marginal increase with increasing concentrations of glucose. PMID:27382204

  13. Carnitine Palmitoyltransferase 1 Increases Lipolysis, UCP1 Protein Expression and Mitochondrial Activity in Brown Adipocytes

    Science.gov (United States)

    Calderon-Dominguez, María; Sebastián, David; Fucho, Raquel; Weber, Minéia; Mir, Joan F.; García-Casarrubios, Ester; Obregón, María Jesús; Zorzano, Antonio; Valverde, Ángela M.; Serra, Dolors

    2016-01-01

    The discovery of active brown adipose tissue (BAT) in adult humans and the fact that it is reduced in obese and diabetic patients have put a spotlight on this tissue as a key player in obesity-induced metabolic disorders. BAT regulates energy expenditure through thermogenesis; therefore, harnessing its thermogenic fat-burning power is an attractive therapeutic approach. We aimed to enhance BAT thermogenesis by increasing its fatty acid oxidation (FAO) rate. Thus, we expressed carnitine palmitoyltransferase 1AM (CPT1AM), a permanently active mutant form of CPT1A (the rate-limiting enzyme in FAO), in a rat brown adipocyte (rBA) cell line through adenoviral infection. We found that CPT1AM-expressing rBA have increased FAO, lipolysis, UCP1 protein levels and mitochondrial activity. Additionally, enhanced FAO reduced the palmitate-induced increase in triglyceride content and the expression of obese and inflammatory markers. Thus, CPT1AM-expressing rBA had enhanced fat-burning capacity and improved lipid-induced derangements. This indicates that CPT1AM-mediated increase in brown adipocytes FAO may be a new approach to the treatment of obesity-induced disorders. PMID:27438137

  14. The Emerging Nexus of Active DNA Demethylation and Mitochondrial Oxidative Metabolism in Post-Mitotic Neurons

    Directory of Open Access Journals (Sweden)

    Huan Meng

    2014-12-01

    Full Text Available The variable patterns of DNA methylation in mammals have been linked to a number of physiological processes, including normal embryonic development and disease pathogenesis. Active removal of DNA methylation, which potentially regulates neuronal gene expression both globally and gene specifically, has been recently implicated in neuronal plasticity, learning and memory processes. Model pathways of active DNA demethylation involve ten-eleven translocation (TET methylcytosine dioxygenases that are dependent on oxidative metabolites. In addition, reactive oxygen species (ROS and oxidizing agents generate oxidative modifications of DNA bases that can be removed by base excision repair proteins. These potentially link the two processes of active DNA demethylation and mitochondrial oxidative metabolism in post-mitotic neurons. We review the current biochemical understanding of the DNA demethylation process and discuss its potential interaction with oxidative metabolism. We then summarise the emerging roles of both processes and their interaction in neural plasticity and memory formation and the pathophysiology of neurodegeneration. Finally, possible therapeutic approaches for neurodegenerative diseases are proposed, including reprogramming therapy by global DNA demethylation and mitohormesis therapy for locus-specific DNA demethylation in post-mitotic neurons.

  15. Implications of mitochondrial DNA mutations and mitochondrial dysfunction in tumorigenesis

    Institute of Scientific and Technical Information of China (English)

    Jianxin Lu; Lokendra Kumar Sharma; Yidong Bai

    2009-01-01

    Alterations in oxidative phosphorylation resulting from mitochondrial dysfunction have long been hypothesized to be involved in tumorigenesis. Mitochondria have recently been shown to play an important role in regulating both programmed cell death and cell proliferation. Furthermore, mitochondrial DNA (mtDNA) mutations have been found in various cancer cells. However, the role of these mtDNA mutations in tumorigenesis remains largely unknown. This review focuses on basic mitochondrial genetics, mtDNA mutations and consequential mitochondrial dysfunction associated with cancer. The potential molecular mechanisms, mediating the pathogenesis from mtDNA mutations and mitochondrial dysfunction to tumorigenesis are also discussed.

  16. Propionyl-L-carnitine corrects metabolic and cardiovascular alterations in diet-induced obese mice and improves liver respiratory chain activity.

    Directory of Open Access Journals (Sweden)

    Carmen Mingorance

    Full Text Available AIMS: Obesity is a primary contributor to acquired insulin resistance leading to the development of type 2 diabetes and cardiovascular alterations. The carnitine derivate, propionyl-L-carnitine (PLC, plays a key role in energy control. Our aim was to evaluate metabolic and cardiovascular effects of PLC in diet-induced obese mice. METHODS: C57BL/6 mice were fed a high-fat diet for 9 weeks and then divided into two groups, receiving either free- (vehicle-HF or PLC-supplemented water (200 mg/kg/day during 4 additional weeks. Standard diet-fed animals were used as lean controls (vehicle-ST. Body weight and food intake were monitored. Glucose and insulin tolerance tests were assessed, as well as the HOMA(IR, the serum lipid profile, the hepatic and muscular mitochondrial activity and the tissue nitric oxide (NO liberation. Systolic blood pressure, cardiac and endothelial functions were also evaluated. RESULTS: Vehicle-HF displayed a greater increase of body weight compared to vehicle-ST that was completely reversed by PLC treatment without affecting food intake. PLC improved the insulin-resistant state and reversed the increased total cholesterol but not the increase in free fatty acid, triglyceride and HDL/LDL ratio induced by high-fat diet. Vehicle-HF exhibited a reduced cardiac output/body weight ratio, endothelial dysfunction and tissue decrease of NO production, all of them being improved by PLC treatment. Finally, the decrease of hepatic mitochondrial activity by high-fat diet was reversed by PLC. CONCLUSIONS: Oral administration of PLC improves the insulin-resistant state developed by obese animals and decreases the cardiovascular risk associated to this metabolic alteration probably via correction of mitochondrial function.

  17. Fuel-Stimulated Insulin Secretion Depends upon Mitochondria Activation and the Integration of Mitochondrial and Cytosolic Substrate Cycles

    Directory of Open Access Journals (Sweden)

    Gary W. Cline

    2011-10-01

    Full Text Available The pancreatic islet β-cell is uniquely specialized to couple its metabolism and rates of insulin secretion with the levels of circulating nutrient fuels, with the mitochondrial playing a central regulatory role in this process. In the β-cell, mitochondrial activation generates an integrated signal reflecting rates of oxidativephosphorylation, Kreb's cycle flux, and anaplerosis that ultimately determines the rate of insulin exocytosis. Mitochondrial activation can be regulated by proton leak and mediated by UCP2, and by alkalinization to utilize the pH gradient to drive substrate and ion transport. Converging lines of evidence support the hypothesis that substrate cycles driven by rates of Kreb's cycle flux and by anaplerosis play an integral role in coupling responsive changes in mitochondrial metabolism with insulin secretion. The components and mechanisms that account for the integrated signal of ATP production, substrate cycling, the regulation of cellular redox state, and the production of other secondary signaling intermediates are operative in both rodent and human islet β-cells.

  18. Silibinin modulates UVB-induced apoptosis via mitochondrial proteins, caspases activation, and mitogen-activated protein kinase signaling in human epidermoid carcinoma A431 cells

    International Nuclear Information System (INIS)

    Several recent studies by us have shown the strong chemopreventive efficacy of silibinin against both ultraviolet B (UVB) radiation and chemical carcinogen-induced tumorigenesis in mouse skin models. The molecular mechanisms underlying silibinin protective efficacy, however, are not completely known. Here, we examined the effect of silibinin on UVB-caused apoptosis in human epidermoid carcinoma A431 cells. Irradiation of cells with different doses of UVB (5-100 mJ/cm2) and different time periods (0.5-24 h) resulted in a dose- and time-dependent increase in apoptosis (P<0.05-0.001). Silibinin (100-200 μM) pre-treatment, however, resulted in an increase in UVB-induced apoptosis (P<0.05-0.001); interestingly, its post-treatment caused a decrease in UVB-induced apoptosis (P<0.05-0.001). A similar pattern in the activation of caspases-9, -3, and -7 was observed with these silibinin treatments. Further, silibinin treatment prior to or immediately after UVB exposure altered Bcl-2, Bax, Bak, and cytochrome c levels in mitochondria and cytosol in favor of or against apoptosis, respectively. Silibinin treatment prior to UVB also increased the activation of mitogen/stress activated protein kinases Erk1/2, JNK, and p38 kinase as compared to its post-treatment. Together, for the first time, our results demonstrate the role of mitochondrial apoptotic machinery and MAPK signaling cascade in silibinin-caused increase as well as protection in UVB-induced apoptosis in A431 cells, and suggest that similar mechanisms might be involved in preventive efficacy of silibinin against UVB-induced skin tumorigenesis

  19. Altered glutamyl-aminopeptidase activity and expression in renal neoplasms

    International Nuclear Information System (INIS)

    Advances in the knowledge of renal neoplasms have demonstrated the implication of several proteases in their genesis, growth and dissemination. Glutamyl-aminopeptidase (GAP) (EC. 3.4.11.7) is a zinc metallopeptidase with angiotensinase activity highly expressed in kidney tissues and its expression and activity have been associated wtih tumour development. In this prospective study, GAP spectrofluorometric activity and immunohistochemical expression were analysed in clear-cell (CCRCC), papillary (PRCC) and chromophobe (ChRCC) renal cell carcinomas, and in renal oncocytoma (RO). Data obtained in tumour tissue were compared with those from the surrounding uninvolved kidney tissue. In CCRCC, classic pathological parameters such as grade, stage and tumour size were stratified following GAP data and analyzed for 5-year survival. GAP activity in both the membrane-bound and soluble fractions was sharply decreased and its immunohistochemical expression showed mild staining in the four histological types of renal tumours. Soluble and membrane-bound GAP activities correlated with tumour grade and size in CCRCCs. This study suggests a role for GAP in the neoplastic development of renal tumours and provides additional data for considering the activity and expression of this enzyme of interest in the diagnosis and prognosis of renal neoplasms

  20. Induction of genomic instability, oxidative processes, and mitochondrial activity by 50Hz magnetic fields in human SH-SY5Y neuroblastoma cells.

    Science.gov (United States)

    Luukkonen, Jukka; Liimatainen, Anu; Juutilainen, Jukka; Naarala, Jonne

    2014-02-01

    Epidemiological studies have suggested that exposure to 50Hz magnetic fields (MF) increases the risk of childhood leukemia, but there is no mechanistic explanation for carcinogenic effects. In two previous studies we have observed that a 24-h pre-exposure to MF alters cellular responses to menadione-induced DNA damage. The aim of this study was to investigate the cellular changes that must occur already during the first 24h of exposure to MF, and to explore whether the MF-induced changes in DNA damage response can lead to genomic instability in the progeny of the exposed cells. In order to answer these questions, human SH-SY5Y neuroblastoma cells were exposed to a 50-Hz, 100-μT MF for 24h, followed by 3-h exposure to menadione. The main finding was that MF exposure was associated with increased level of micronuclei, used as an indicator of induced genomic instability, at 8 and 15d after the exposures. Other delayed effects in MF-exposed cells included increased mitochondrial activity at 8d, and increased reactive oxygen species (ROS) production and lipid peroxidation at 15d after the exposures. Oxidative processes (ROS production, reduced glutathione level, and mitochondrial superoxide level) were affected by MF immediately after the exposure. In conclusion, the present results suggest that MF exposure disturbs oxidative balance immediately after the exposure, which might explain our previous findings on MF altered cellular responses to menadione-induced DNA damage. Persistently elevated levels of micronuclei were found in the progeny of MF-exposed cells, indicating induction of genomic instability. PMID:24374227

  1. Low ozone concentrations stimulate cytoskeletal organization, mitochondrial activity and nuclear transcription

    Directory of Open Access Journals (Sweden)

    M. Costanzo

    2015-04-01

    Full Text Available Ozone therapy is a modestly invasive procedure based on the regeneration capabilities of low ozone concentrations and used in medicine as an alternative/adjuvant treatment for different diseases. However, the cellular mechanisms accounting for the positive effects of mild ozonization are still largely unexplored. To this aim, in the present study the effects of low ozone concentrations (1 to 20 µg O3/mL O2 on structural and functional cell features have been investigated in vitro by using morphological, morphometrical, cytochemical and immunocytochemical techniques at bright field, fluorescence and transmission electron microscopy. Cells exposed to pure O2 or air served as controls. The results demonstrated that the effects of ozoneadministration are dependent on gas concentration, and the cytoskeletal organization, mitochondrial activity and nuclear transcription may be differently affected. This suggests that, to ensure effective and permanent metabolic cell activation, ozone treatments should take into account the cytological and cytokinetic features of the different tissues. 

  2. Silver and Gold Nanoparticles Alter Cathepsin Activity In vitro

    Science.gov (United States)

    Speshock, Janice L.; Braydich-Stolle, Laura K.; Szymanski, Eric R.; Hussain, Saber M.

    2011-12-01

    Nanomaterials are being incorporated into many biological applications for use as therapeutics, sensors, or labels. Silver nanomaterials are being utilized for biological implants and wound dressings as an antiviral material, whereas gold nanomaterials are being used as biological labels or sensors due to their surface properties and biocompatibility. Cytotoxicity data of these materials are becoming more prevalent; however, little research has been performed to understand how the introduction of these materials into cells affects cellular processes. Here, we demonstrate the impact that silver and gold nanoparticles have on cathepsin activity in vitro. Cathepsins are important cellular proteases that are imperative for proper immune system function. We have selected to examine gold and silver nanoparticles due to the increased use of these materials in biological applications. This manuscript depicts how both of these types of nanomaterials affect cathepsin activity, which could impact the host's immune system and its ability to respond to pathogens. Cathepsin B activity decreases in a dose-dependent manner with all nanoparticles tested. Alternatively, the impact of nanoparticles on cathepsin L activity depends greatly on the type and size of the material.

  3. Altered Error-Related Activity in Patients with Schizophrenia

    Science.gov (United States)

    Koch, Kathrin; Wagner, Gerd; Schultz, Christoph; Schachtzabel, Claudia; Nenadic, Igor; Axer, Martina; Reichenbach, Jurgen R.; Sauer, Heinrich; Schlosser, Ralf G. M.

    2009-01-01

    Deficits in working memory (WM) and executive cognitive control are core features of schizophrenia. However, findings regarding functional activation strengths are heterogeneous, partly due to differences in task demands and behavioral performance. Previous investigators proposed integrating these heterogeneous findings into a comprehensive model…

  4. Mitochondrial activity and oxidative stress markers in peripheral blood mononuclear cells of patients with bipolar disorder, schizophrenia, and healthy subjects.

    Science.gov (United States)

    Gubert, Carolina; Stertz, Laura; Pfaffenseller, Bianca; Panizzutti, Bruna Schilling; Rezin, Gislaine Tezza; Massuda, Raffael; Streck, Emilio Luiz; Gama, Clarissa Severino; Kapczinski, Flávio; Kunz, Maurício

    2013-10-01

    Evidence suggests that mitochondrial dysfunction is involved in the pathophysiology of psychiatric disorders such as schizophrenia (SZ) and bipolar disorder (BD). However, the exact mechanisms underlying this dysfunction are not well understood. Impaired activity of electron transport chain (ETC) complexes has been described in these disorders and may reflect changes in mitochondrial metabolism and oxidative stress markers. The objective of this study was to compare ETC complex activity and protein and lipid oxidation markers in 12 euthymic patients with BD type I, in 18 patients with stable chronic SZ, and in 30 matched healthy volunteers. Activity of complexes I, II, and III was determined by enzyme kinetics of mitochondria isolated from peripheral blood mononuclear cells (PBMCs). Protein oxidation was evaluated using the protein carbonyl content (PCC) method, and lipid peroxidation, the thiobarbituric acid reactive substances (TBARS) assay kit. A significant decrease in complex I activity was observed (p = 0.02), as well as an increase in plasma levels of TBARS (p = 0.00617) in patients with SZ when compared to matched controls. Conversely, no significant differences were found in complex I activity (p = 0.17) or in plasma TBARS levels (p = 0.26) in patients with BD vs. matched controls. Our results suggest that mitochondrial complex I dysfunction and oxidative stress play important roles in the pathophysiology of SZ and may be used in potential novel adjunctive therapy for SZ, focusing primarily on cognitive impairment and disorder progression. PMID:23870796

  5. The importance of mitochondrial DNA in aging and cancer

    DEFF Research Database (Denmark)

    Madsen, Claus Desler; Espersen, Maiken Lise Marcker; Singh, Keshav K;

    2011-01-01

    Mitochondrial dysfunction has been implicated in premature aging, age-related diseases, and tumor initiation and progression. Alterations of the mitochondrial genome accumulate both in aging tissue and tumors. This paper describes our contemporary view of mechanisms by which alterations of the...... mitochondrial genome contributes to the development of age- and tumor-related pathological conditions. The mechanisms described encompass altered production of mitochondrial ROS, altered regulation of the nuclear epigenome, affected initiation of apoptosis, and a limiting effect on the production of...

  6. Mitochondrial and glycolytic activity of UV-irradiated human keratinocytes and its stimulation by a Saccharomyces cerevisiae autolysate.

    Science.gov (United States)

    Schütz, Rolf; Kuratli, Karin; Richard, Nathalie; Stoll, Clarissa; Schwager, Joseph

    2016-06-01

    Cutaneous aging is correlated with mitochondrial dysfunction and a concomitant decline in energy metabolism that can be accelerated by extrinsic factors such as UV radiation (UVR). In this study we compared cellular bioenergetics of normal and UV-irradiated primary human epidermal keratinocytes. Moreover, we investigated the influence of a Saccharomyces cerevisiae autolysate (SCA) on stressed keratinocytes to regain cellular homeostasis. Cellular metabolism was assessed by extracellular flux analysis which measures oxygen consumption rate (OCR) and extracellular acidification rate (ECAR) as well as by ATP quantification. The expression level of ten mitochondria related genes in normal and UVR-stimulated (60mJ/cm(2) UVB) keratinocytes was quantified by real-time PCR and the impact of SCA addition was determined. Sublethal UV stress increased mitochondrial dysfunction in keratinocytes which resulted in reduced viability, uncoupled oxidative phosphorylation, and down-regulated mitochondrial gene expression. Particularly, gene expression of SHDA, UPC2, BID, and ATP5A1 was reduced about twofold within 4h. Treatment of keratinocytes with SCA shifted cellular metabolism towards a more energetic status by increasing the respiratory rate and glycolysis. SCA also stimulated cellular ATP production after short (4h) and prolonged (22h) incubations and induced the expression of genes related to mitochondrial function towards normal expression levels upon UV irradiation. The decreased respiratory capacity of UV-irradiated keratinocytes was partially compensated by the addition of SCA which enhanced glycolytic activity and thereby increased cellular resistance to environmental stress. PMID:27060217

  7. Genetic Transferability of Anomalous Irradiation Alterations of Antibiotic Activity

    OpenAIRE

    Bass, George E.

    2007-01-01

    It previously has been discovered that visible light irradiation of crystalline substrates can lead to enhancement of subsequent enzymatic reaction rates as sharply peaked oscillatory functions of irradiation time. The particular activating irradiation times can vary with source of a given enzyme and thus, presumably, its molecular structure. The experiments reported here demonstrate that the potential for this anomalous enzyme reaction rate enhancement can be transferred from one bacterial s...

  8. Activation of AMPKα2 is not crucial for mitochondrial uncoupling-induced metabolic effects but required to maintain skeletal muscle integrity.

    Directory of Open Access Journals (Sweden)

    Mario Ost

    Full Text Available Transgenic (UCP1-TG mice with ectopic expression of UCP1 in skeletal muscle (SM show a phenotype of increased energy expenditure, improved glucose tolerance and increase substrate metabolism in SM. To investigate the potential role of skeletal muscle AMPKα2 activation in the metabolic phenotype of UCP1-TG mice we generated double transgenic (DTG mice, by crossing of UCP1-TG mice with DN-AMPKα2 mice overexpressing a dominant negative α2 subunit of AMPK in SM which resulted in an impaired AMPKα2 activity by 90±9% in SM of DTG mice. Biometric analysis of young male mice showed decreased body weight, lean and fat mass for both UCP1-TG and DTG compared to WT and DN-AMPKα2 mice. Energy intake and weight-specific total energy expenditure were increased, both in UCP1-TG and DTG mice. Moreover, glucose tolerance, insulin sensitivity and fatty acid oxidation were not altered in DTG compared to UCP1-TG. Also uncoupling induced induction and secretion of fibroblast growth factor 21 (FGF21 from SM was preserved in DTG mice. However, voluntary physical cage activity as well as ad libitum running wheel access during night uncovered a severe activity intolerance of DTG mice. Histological analysis showed a progressive degenerative morphology in SM of DTG mice which was not observed in SM of UCP1-TG mice. Moreover, ATP-depletion related cellular stress response via heat shock protein 70 was highly induced, whereas capillarization regulator VEGF was suppressed in DTG muscle. In addition, AMPKα2-mediated induction of mitophagy regulator ULK1 was suppressed in DTG mice, as well as mitochondrial respiratory capacity and content. In conclusion, we demonstrate that AMPKα2 is dispensable for SM mitochondrial uncoupling induced metabolic effects on whole body energy balance, glucose homeostasis and insulin sensitivity. But strikingly, activation of AMPKα2 seems crucial for maintaining SM function, integrity and the ability to compensate chronic metabolic stress

  9. ALTERED ENZYMATIC ACTIVITY OF LYSOZYMES BOUND TO VARIOUSLY SULFATED CHITOSANS

    Institute of Scientific and Technical Information of China (English)

    Hong-wei Wang; Lin Yuan; Tie-liang Zhao; He Huang; Hong Chen; Di Wu

    2012-01-01

    The purpose of this research is to investigate the effects of the variously sulfated chitosans on lysozyme activity and structure.It was shown that the specific enzymatic activity of lysozyme remained almost similar to the native protein after being bound to 6-O-sulfated chitosan (6S-chitosan) and 3,6-O-sulfated chitosan (3,6S-chitosan),but decreased greatly after being bound to 2-N-6-O-sulfated chitosan (2,6S-chitosan).Meanwhile,among these sulfated chitosans,2,6S-chitosan induced the greatest conformational change in lysozyme as indicated by the fluorescence spectra.These findings demonstrated that when sulfated chitosans of different structures bind to lysozyme,lysozyme undergoes conformational change of different magnitudes,which results in corresponding levels of lysozyme activity.Further study on the interaction of sulfated chitosans with lysozyme by surface plasmon resonance (SPR) suggested that their affinities might be determined by their molecular structures.

  10. Adenine nucleotide-dependent and redox-independent control of mitochondrial malate dehydrogenase activity in Arabidopsis thaliana.

    Science.gov (United States)

    Yoshida, Keisuke; Hisabori, Toru

    2016-06-01

    Mitochondrial metabolism is important for sustaining cellular growth and maintenance; however, the regulatory mechanisms underlying individual processes in plant mitochondria remain largely uncharacterized. Previous redox-proteomics studies have suggested that mitochondrial malate dehydrogenase (mMDH), a key enzyme in the tricarboxylic acid (TCA) cycle and redox shuttling, is under thiol-based redox regulation as a target candidate of thioredoxin (Trx). In addition, the adenine nucleotide status may be another factor controlling mitochondrial metabolism, as respiratory ATP production in mitochondria is believed to be influenced by several environmental stimuli. Using biochemical and reverse-genetic approaches, we addressed the redox- and adenine nucleotide-dependent regulation of mMDH in Arabidopsis thaliana. Recombinant mMDH protein formed intramolecular disulfide bonds under oxidative conditions, but these bonds did not have a considerable effect on mMDH activity. Mitochondria-localized o-type Trx (Trx-o) did not facilitate re-reduction of oxidized mMDH. Determination of the in vivo redox state revealed that mMDH was stably present in the reduced form even in Trx-o-deficient plants. Accordingly, we concluded that mMDH is not in the class of redox-regulated enzymes. By contrast, mMDH activity was lowered by adenine nucleotides (AMP, ADP, and ATP). Each adenine nucleotide suppressed mMDH activity with different potencies and ATP exerted the largest inhibitory effect with a significantly lower Ki. Correspondingly, mMDH activity was inhibited by the increase in ATP/ADP ratio within the physiological range. These results suggest that mMDH activity is finely controlled in response to variations in mitochondrial adenine nucleotide balance. PMID:26946085

  11. The m.13051G>A mitochondrial DNA mutation results in variable neurology and activated mitophagy

    OpenAIRE

    Dombi, E.; Diot, A.; Morten, K.; Carver, J; Lodge, T.; Fratter, C.; Ng, Y.S.; Liao, C.; Muir, R; Blakely, E.L.; Hargreaves, I; Al-Dosary, M.; Sarkar, G; Hickman, S. J.; Downes, S M

    2016-01-01

    Maternally inherited mitochondrial DNA (mtDNA) mutations cause symptoms of Leber hereditary optic neuropathy (LHON) in -1 in 30,000 individuals. Most of the affected individuals lack respiratory chain defects1 and there is no proven prophylactic treatment.

  12. Estrogen receptor alpha activation enhances mitochondrial function and systemic metabolism in high-fat-fed ovariectomized mice.

    Science.gov (United States)

    Hamilton, Dale J; Minze, Laurie J; Kumar, Tanvi; Cao, Tram N; Lyon, Christopher J; Geiger, Paige C; Hsueh, Willa A; Gupte, Anisha A

    2016-09-01

    Estrogen impacts insulin action and cardiac metabolism, and menopause dramatically increases cardiometabolic risk in women. However, the mechanism(s) of cardiometabolic protection by estrogen remain incompletely understood. Here, we tested the effects of selective activation of E2 receptor alpha (ERα) on systemic metabolism, insulin action, and cardiac mitochondrial function in a mouse model of metabolic dysfunction (ovariectomy [OVX], insulin resistance, hyperlipidemia, and advanced age). Middle-aged (12-month-old) female low-density lipoprotein receptor (Ldlr)(-/-) mice were subjected to OVX or sham surgery and fed "western" high-fat diet (WHFD) for 3 months. Selective ERα activation with 4,4',4″-(4-Propyl-[1H]-pyrazole-1,3,5-triyl) (PPT), prevented weight gain, improved insulin action, and reduced visceral fat accumulation in WHFD-fed OVX mice. PPT treatment also elevated systemic metabolism, increasing oxygen consumption and core body temperature, induced expression of several metabolic genes such as peroxisome proliferator-activated receptor gamma, coactivator 1 alpha, and nuclear respiratory factor 1 in heart, liver, skeletal muscle, and adipose tissue, and increased cardiac mitochondrial function. Taken together, selective activation of ERα with PPT enhances metabolic effects including insulin resistance, whole body energy metabolism, and mitochondrial function in OVX mice with metabolic syndrome. PMID:27582063

  13. The mitochondrial complex I activity is reduced in cells with impaired cystic fibrosis transmembrane conductance regulator (CFTR function.

    Directory of Open Access Journals (Sweden)

    Angel G Valdivieso

    Full Text Available Cystic fibrosis (CF is a frequent and lethal autosomal recessive disease. It results from different possible mutations in the CFTR gene, which encodes the CFTR chloride channel. We have previously studied the differential expression of genes in CF and CF corrected cell lines, and found a reduced expression of MTND4 in CF cells. MTND4 is a mitochondrial gene encoding the MTND4 subunit of the mitochondrial Complex I (mCx-I. Since this subunit is essential for the assembly and activity of mCx-I, we have now studied whether the activity of this complex was also affected in CF cells. By using Blue Native-PAGE, the in-gel activity (IGA of the mCx-I was found reduced in CFDE and IB3-1 cells (CF cell lines compared with CFDE/6RepCFTR and S9 cells, respectively (CFDE and IB3-1 cells ectopically expressing wild-type CFTR. Moreover, colon carcinoma T84 and Caco-2 cells, which express wt-CFTR, either treated with CFTR inhibitors (glibenclamide, CFTR(inh-172 or GlyH101 or transfected with a CFTR-specific shRNAi, showed a significant reduction on the IGA of mCx-I. The reduction of the mCx-I activity caused by CFTR inhibition under physiological or pathological conditions may have a profound impact on mitochondrial functions of CF and non-CF cells.

  14. Reduction of mitochondrial electron transport complex activity is restricted to the ischemic focus after transient focal cerebral ischemia in rats

    DEFF Research Database (Denmark)

    Christensen, Thomas; Diemer, Nils Henrik

    2003-01-01

    the ipsilateral cortex and caudate putamen were measured by densitometric image analysis. Reductions in complex I, II, and IV activity were restricted to areas in the ischemic foci in cortex and caudate putamen, which microscopically displayed signs of early morphological damage. In cortex, the tissue...... volume with reduced activity did not change significantly during reperfusion but progressively increased in the caudate putamen, possibly reflecting a faster maturation of morphological damage in this region. Treatment with alpha-PBN did not affect the observed reductions in activities. We deduce that...... inhibition of mitochondrial ETC complex activity does not play a critical role for recruitment of the penumbra in the infarction process....

  15. Postnatal foraging demands alter adrenocortical activity and psychosocial development.

    Science.gov (United States)

    Lyons, D M; Kim, S; Schatzberg, A F; Levine, S

    1998-05-01

    Mother squirrel monkeys stop carrying infants at earlier ages in high-demand (HD) conditions where food is difficult to find relative to low-demand (LD) conditions. To characterize these transitions in psychosocial development, from 10- to 21-weeks postpartum we collected measures of behavior, adrenocortical activity, and social transactions coded for initiator (mother or infant), goal (make-contact or break-contact), and outcome (success or failure). Make-contact attempts were most often initiated by HD infants, but mothers often opposed these attempts and less than 50% were successful. Break-contact attempts were most often initiated by LD infants, but mothers often opposed these attempts and fewer LD than HD infant break-contact attempts were successful. Plasma levels of cortisol were significantly higher in HD than LD mothers, but differences in adrenocortical activity were less consistent in their infants. HD and LD infants also spent similar amounts of time nursing on their mothers and feeding on solid foods. By rescheduling some transitions in development (carry-->self-transport), and not others (nursing-->self-feeding), mothers may have partially protected infants from the immediate impact of an otherwise stressful foraging task. PMID:9589217

  16. Alterations in electrodermal activity and cardiac parasympathetic tone during hypnosis.

    Science.gov (United States)

    Kekecs, Zoltán; Szekely, Anna; Varga, Katalin

    2016-02-01

    Exploring autonomic nervous system (ANS) changes during hypnosis is critical for understanding the nature and extent of the hypnotic phenomenon and for identifying the mechanisms underlying the effects of hypnosis in different medical conditions. To assess ANS changes during hypnosis, electrodermal activity and pulse rate variability (PRV) were measured in 121 young adults. Participants either received hypnotic induction (hypnosis condition) or listened to music (control condition), and both groups were exposed to test suggestions. Blocks of silence and experimental sound stimuli were presented at baseline, after induction, and after de-induction. Skin conductance level (SCL) and high frequency (HF) power of PRV measured at each phase were compared between groups. Hypnosis decreased SCL compared to the control condition; however, there were no group differences in HF power. Furthermore, hypnotic suggestibility did not moderate ANS changes in the hypnosis group. These findings indicate that hypnosis reduces tonic sympathetic nervous system activity, which might explain why hypnosis is effective in the treatment of disorders with strong sympathetic nervous system involvement, such as rheumatoid arthritis, hot flashes, hypertension, and chronic pain. Further studies with different control conditions are required to examine the specificity of the sympathetic effects of hypnosis. PMID:26488759

  17. Blocking TGF-β Signaling Pathway Preserves Mitochondrial Proteostasis and Reduces Early Activation of PDGFRβ+ Pericytes in Aristolochic Acid Induced Acute Kidney Injury in Wistar Male Rats

    Science.gov (United States)

    Pozdzik, Agnieszka A.; Giordano, Laetitia; Li, Gang; Antoine, Marie-Hélène; Quellard, Nathalie; Godet, Julie; De Prez, Eric; Husson, Cécile; Declèves, Anne-Emilie; Arlt, Volker M.; Goujon, Jean-Michel; Brochériou-Spelle, Isabelle; Ledbetter, Steven R.; Caron, Nathalie; Nortier, Joëlle L.

    2016-01-01

    Background The platelet-derived growth factor receptor β (PDGFRβ)+ perivascular cell activation becomes increasingly recognized as a main source of scar-associated kidney myofibroblasts and recently emerged as a new cellular therapeutic target. Aims In this regard, we first confirmed the presence of PDGFRβ+ perivascular cells in a human case of end-stage aristolochic acid nephropathy (AAN) and thereafter we focused on the early fibrosis events of transforming growth factor β (TGFβ) inhibition in a rat model of AAN. Materials and Methods Neutralizing anti-TGFβ antibody (1D11) and its control isotype (13C4) were administered (5 mg/kg, i.p.) at Days -1, 0, 2 and 4; AA (15 mg/kg, sc) was injected daily. Results At Day 5, 1D11 significantly suppressed p-Smad2/3 signaling pathway improving renal function impairment, reduced the score of acute tubular necrosis, peritubular capillaritis, interstitial inflammation and neoangiogenesis. 1D11 markedly decreased interstitial edema, disruption of tubular basement membrane loss of brush border, cytoplasmic edema and organelle ultrastructure alterations (mitochondrial disruption and endoplasmic reticulum edema) in proximal tubular epithelial cells. Moreover, 1D11 significantly inhibited p-PERK activation and attenuated dysregulation of unfolded protein response (UPR) pathways, endoplasmic reticulum and mitochondrial proteostasis in vivo and in vitro. Conclusions The early inhibition of p-Smad2/3 signaling pathway improved acute renal function impairment, partially prevented epithelial-endothelial axis activation by maintaining PTEC proteostasis and reduced early PDGFRβ+ pericytes-derived myofibroblasts accumulation. PMID:27379382

  18. Mitochondrial reactive oxygen species enhance AMP-activated protein kinase activation in the endothelium of patients with coronary artery disease and diabetes

    OpenAIRE

    Mackenzie, Ruth M.; Salt, Ian P.; Miller, William H.; et al.

    2013-01-01

    The aim of the present study was to determine whether the endothelial dysfunction associated with CAD (coronary artery disease) and T2D (Type 2 diabetes mellitus) is concomitant with elevated mtROS (mitochondrial reactive oxygen species) production in the endothelium and establish if this, in turn, regulates the activity of endothelial AMPK (AMP-activated protein kinase). We investigated endothelial function, mtROS production and AMPK activation in saphenous veins from patients with advanced ...

  19. Sensory Nerve Terminal Mitochondrial Dysfunction Activates Airway Sensory Nerves via Transient Receptor Potential (TRP) Channels

    OpenAIRE

    Nesuashvili, Lika; Hadley, Stephen H; Parmvir K Bahia; Taylor-Clark, Thomas E.

    2013-01-01

    Mitochondrial dysfunction and subsequent oxidative stress has been reported for a variety of cell types in inflammatory diseases. Given the abundance of mitochondria at the peripheral terminals of sensory nerves and the sensitivity of transient receptor potential (TRP) ankyrin 1 (A1) and TRP vanilloid 1 (V1) to reactive oxygen species (ROS) and their downstream products of lipid peroxidation, we investigated the effect of nerve terminal mitochondrial dysfunction on airway sensory nerve excita...

  20. Activation of AMPKα2 Is Not Required for Mitochondrial FAT/CD36 Accumulation during Exercise

    OpenAIRE

    Monaco, Cynthia; Whitfield, Jamie; Jain, Swati S.; Spriet, Lawrence L.; Bonen, Arend; Holloway, Graham P.

    2015-01-01

    Exercise has been shown to induce the translocation of fatty acid translocase (FAT/CD36), a fatty acid transport protein, to both plasma and mitochondrial membranes. While previous studies have examined signals involved in the induction of FAT/CD36 translocation to sarcolemmal membranes, to date the signaling events responsible for FAT/CD36 accumulation on mitochondrial membranes have not been investigated. In the current study muscle contraction rapidly increased FAT/CD36 on plasma membranes...

  1. Mitochondrial dysfunction in liver failure requiring transplantation.

    Science.gov (United States)

    Lane, Maria; Boczonadi, Veronika; Bachtari, Sahar; Gomez-Duran, Aurora; Langer, Thorsten; Griffiths, Alexandra; Kleinle, Stephanie; Dineiger, Christine; Abicht, Angela; Holinski-Feder, Elke; Schara, Ulrike; Gerner, Patrick; Horvath, Rita

    2016-05-01

    Liver failure is a heterogeneous condition which may be fatal and the primary cause is frequently unknown. We investigated mitochondrial oxidative phosphorylation in patients undergoing liver transplantation. We studied 45 patients who had liver transplantation due to a variety of clinical presentations. Blue native polyacrylamide gel electrophoresis with immunodetection of respiratory chain complexes I-V, biochemical activity of respiratory chain complexes II and IV and quantification of mitochondrial DNA (mtDNA) copy number were investigated in liver tissue collected from the explanted liver during transplantation. Abnormal mitochondrial function was frequently present in this cohort: ten of 40 patients (25 %) had a defect of one or more respiratory chain enzyme complexes on blue native gels, 20 patients (44 %) had low activity of complex II and/or IV and ten (22 %) had a reduced mtDNA copy number. Combined respiratory chain deficiency and reduced numbers of mitochondria were detected in all three patients with acute liver failure. Low complex IV activity in biliary atresia and complex II defects in cirrhosis were common findings. All six patients diagnosed with liver tumours showed variable alterations in mitochondrial function, probably due to the heterogeneity of the presenting tumour. In conclusion, mitochondrial dysfunction is common in severe liver failure in non-mitochondrial conditions. Therefore, in contrast to the common practice detection of respiratory chain abnormalities in liver should not restrict the inclusion of patients for liver transplantation. Furthermore, improving mitochondrial function may be targeted as part of a complex therapy approach in different forms of liver diseases. PMID:27053192

  2. Activation of the Pleiotropic Drug Resistance Pathway Can Promote Mitochondrial DNA Retention by Fusion-Defective Mitochondria in Saccharomyces cerevisiae

    OpenAIRE

    Dunn, Cory, D.; Mutlu, Nebibe; Garipler, Gorkem; Akdogan, Emel

    2014-01-01

    1 Activation of the pleiotropic drug resistance pathway can promote mitochondrial DNA retention by fusion-defective mitochondria in Saccharomyces cerevisiae Nebibe Mutlu1, Görkem Garipler, Emel Akdoğan and Cory D. Dunn Department of Molecular Biology and Genetics Koç University Sarıyer, İstanbul, 34450 Turkey 1 Present address: Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, 48109, U.S.A. NCBI Sequence...

  3. Altered behaviour in spotted hyenas associated with increased human activity

    Science.gov (United States)

    Boydston, E.E.; Kapheim, K.M.; Watts, H.E.; Szykman, M.; Holekamp, K.E.

    2003-01-01

    To investigate how anthropogenic activity might affect large carnivores, we studied the behaviour of spotted hyenas (Crocuta crocuta) during two time periods. From 1996 to 1998, we documented the ecological correlates of space utilization patterns exhibited by adult female hyenas defending a territory at the edge of a wildlife reserve in Kenya. Hyenas preferred areas near dense vegetation but appeared to avoid areas containing the greatest abundance of prey, perhaps because these were also the areas of most intensive livestock grazing. We then compared hyena behaviour observed in 1996-98 with that observed several years earlier and found many differences. Female hyenas in 1996-98 were found farther from dens, but closer to dense vegetation and to the edges of their territory, than in 1988-90. Recent females also had larger home ranges, travelled farther between consecutive sightings, and were more nocturnal than in 1988-90. Finally, hyenas occurred in smaller groups in 1996-98 than in 1988-90. We also found several changes in hyena demography between periods. We next attempted to explain differences observed between time periods by testing predictions of hypotheses invoking prey abundance, climate, interactions with lions, tourism and livestock grazing. Our data were consistent with the hypothesis that increased reliance on the reserve for livestock grazing was responsible for observed changes. That behavioural changes were not associated with decreased hyena population density suggests the behavioural plasticity typical of this species may protect it from extinction. ?? 2003 The Zoological Society of London.

  4. Mitochondrial metabolism and the control of vascular smooth muscle cell proliferation

    Directory of Open Access Journals (Sweden)

    Mario eChiong

    2014-12-01

    Full Text Available Differentiation and dedifferentiation of vascular smooth muscle cells (VSMCs are essential processes of vascular development. VSMCs have biosynthetic, proliferative and contractile roles in the vessel wall. Alterations in the differentiated state of the VSMCs play a critical role in the pathogenesis of a variety of cardiovascular diseases, including atherosclerosis, hypertension and vascular stenosis. This review provides an overview of the current state of knowledge of molecular mechanisms involved in the control of VSMC proliferation, with particular focus on mitochondrial metabolism. Mitochondrial activity can be controlled by regulating mitochondrial dynamics, i.e. mitochondrial fusion and fission, and by regulating mitochondrial calcium handling through the interaction with the endoplasmic reticulum (ER. Alterations in both VSMC proliferation and mitochondrial function can be triggered by dysregulation of mitofusin-2, a small GTPase associated with mitochondrial fusion and mitochondrial-ER interaction. Several lines of evidence highlight the relevance of mitochondrial metabolism in the control of VSMC proliferation, indicating a new area to be explored in the treatment of vascular diseases.

  5. Mitochondrial intermediate peptidase: Expression in Escherichia coli and improvement of its enzymatic activity detection with FRET substrates

    International Nuclear Information System (INIS)

    In the present study, soluble, functionally-active, recombinant human mitochondrial intermediate peptidase (hMIP), a mitochondrial metalloendoprotease, was expressed in a prokaryotic system. The hMIP fusion protein, with a poly-His-tag (6x His), was obtained by cloning the coding region of hMIP cDNA into the pET-28a expression vector, which was then used to transform Escherichia coli BL21 (DE3) pLysS. After isolation and purification of the fusion protein by affinity chromatography using Ni-Sepharose resin, the protein was purified further using ion exchange chromatography with a Hi-trap resource Q column. The recombinant hMIP was characterized by Western blotting using three distinct antibodies, circular dichroism, and enzymatic assays that used the first FRET substrates developed for MIP and a series of protease inhibitors. The successful expression of enzymatically-active hMIP in addition to the FRET substrates will contribute greatly to the determination of substrate specificity of this protease and to the development of specific inhibitors that are essential for a better understanding of the role of this protease in mitochondrial functioning.

  6. Mechanism of mitochondrial uncouplers, inhibitors, and toxins: focus on electron transfer, free radicals, and structure-activity relationships.

    Science.gov (United States)

    Kovacic, Peter; Pozos, Robert S; Somanathan, Ratnasamy; Shangari, Nandita; O'Brien, Peter J

    2005-01-01

    The biology of the mitochondrial electron transport chain is summarized. Our approach to the mechanism of uncouplers, inhibitors, and toxins is based on electron transfer (ET) and reactive oxygen species (ROS). Extensive supporting evidence, which is broadly applicable, is cited. ROS can be generated either endogenously or exogenously. Generally, the reactive entities arise via redox cycling by ET functionalities, such as, quinones (or precursors), metal compounds, imines (or iminiums), and aromatic nitro compounds (or reduced metabolites). In most cases, the ET functions are formed metabolically. The toxic substances belong to many categories, e.g., medicinals, industrial chemicals, abused drugs, and pesticides. Structure-activity relationships are presented from the ET-ROS perspective, and also quantitatively. Evidence for the theoretical framework is provided by the protective effect of antioxidants. Among other topics addressed are proton flux, membrane pores, and apoptosis. There is support for the thesis that mitochondrial insult may contribute to illnesses and aging. PMID:16248817

  7. Pre-symptomatic activation of antioxidant responses and alterations in glucose and pyruvate metabolism in Niemann-Pick Type C1-deficient murine brain.

    Directory of Open Access Journals (Sweden)

    Barry E Kennedy

    Full Text Available Niemann-Pick Type C (NPC disease is an autosomal recessive neurodegenerative disorder caused in most cases by mutations in the NPC1 gene. NPC1-deficiency is characterized by late endosomal accumulation of cholesterol, impaired cholesterol homeostasis, and a broad range of other cellular abnormalities. Although neuronal abnormalities and glial activation are observed in nearly all areas of the brain, the most severe consequence of NPC1-deficiency is a near complete loss of Purkinje neurons in the cerebellum. The link between cholesterol trafficking and NPC pathogenesis is not yet clear; however, increased oxidative stress in symptomatic NPC disease, increases in mitochondrial cholesterol, and alterations in autophagy/mitophagy suggest that mitochondria play a role in NPC disease pathology. Alterations in mitochondrial function affect energy and neurotransmitter metabolism, and are particularly harmful to the central nervous system. To investigate early metabolic alterations that could affect NPC disease progression, we performed metabolomics analyses of different brain regions from age-matched wildtype and Npc1 (-/- mice at pre-symptomatic, early symptomatic and late stage disease by (1H-NMR spectroscopy. Metabolic profiling revealed markedly increased lactate and decreased acetate/acetyl-CoA levels in Npc1 (-/- cerebellum and cerebral cortex at all ages. Protein and gene expression analyses indicated a pre-symptomatic deficiency in the oxidative decarboxylation of pyruvate to acetyl-CoA, and an upregulation of glycolytic gene expression at the early symptomatic stage. We also observed a pre-symptomatic increase in several indicators of oxidative stress and antioxidant response systems in Npc1 (-/- cerebellum. Our findings suggest that energy metabolism and oxidative stress may present additional therapeutic targets in NPC disease, especially if intervention can be started at an early stage of the disease.

  8. Altered sensorimotor activation patterns in idiopathic dystonia-an activation likelihood estimation meta-analysis of functional brain imaging studies

    DEFF Research Database (Denmark)

    Løkkegaard, Annemette; Herz, Damian M; Haagensen, Brian N;

    2016-01-01

    . Further, study size was usually small including different types of dystonia. Here we performed an activation likelihood estimation (ALE) meta-analysis of functional neuroimaging studies in patients with primary dystonia to test for convergence of dystonia-related alterations in task-related activity....... Hum Brain Mapp 37:547-557, 2016. © 2015 Wiley Periodicals, Inc....

  9. Effect of inorganic phosphate concentration on the nature of inner mitochondrial membrane alterations mediated by Ca2+ ions. A proposed model for phosphate-stimulated lipid peroxidation.

    Science.gov (United States)

    Kowaltowski, A J; Castilho, R F; Grijalba, M T; Bechara, E J; Vercesi, A E

    1996-02-01

    Addition of high concentrations (>1 mm) of inorganic phosphate (Pi) or arsenate to Ca2+-loaded mitochondria was followed by increased rates of H2O2 production, membrane lipid peroxidation, and swelling. Mitochondrial swelling was only partially prevented either by butylhydroxytoluene, an inhibitor of lipid peroxidation, or cyclosporin A, an inhibitor of the mitochondrial permeability transition pore. This swelling was totally prevented by the simultaneous presence of these compounds. At lower Pi concentrations (1 mm), mitochondrial swelling is reversible and prevented by cyclosporin A, but not by butylhydroxytoluene. In any case (low or high phosphate concentration) exogenous catalase prevented mitochondrial swelling, suggesting that reactive oxygen species (ROS) participate in these mechanisms. Altogether, the data suggest that, at low Pi concentrations, membrane permeabilization is reversible and mediated by opening of the mitochondrial permeability transition pore, whereas at high Pi concentrations, membrane permeabilization is irreversible because lipid peroxidation also takes place. Under these conditions, lipid peroxidation is strongly inhibited by sorbate, a putative quencher of triplet carbonyl species. This suggests that high Pi or arsenate concentrations stimulate propagation of the peroxidative reactions initiated by mitochondrial-generated ROS because these anions are able to catalyze Cn-aldehyde tautomerization producing enols, which can be oxidized by hemeproteins to yield the lower Cn - 1-aldehyde in the triplet state. This proposition was also supported by experiments using a model system consisting of phosphatidylcholine/dicethylphosphate liposomes and the triplet acetone-generating system isobutanal/horseradish peroxidase, where phosphate and Ca2+ cooperate to increase the yield of thiobarbituric acid-reactive substances. PMID:8621682

  10. The mitochondrial Na+/Ca2+exchanger may reduce high glucose-induced oxidative stress and nucleotide-binding oligomerization domain receptor 3 inflammasome activation in endothelial cells

    Institute of Scientific and Technical Information of China (English)

    Yuan ZU; Li-Juan WAN; Shao-Yuan CUI; Yan-Ping GONG; Chun-Lin LI

    2015-01-01

    Background The mitochondrial Na+/Ca2+exchanger, NCLX, plays an important role in the balance between Ca2+influx and efflux across the mitochondrial inner membrane in endothelial cells. Mitochondrial metabolism is likely to be affected by the activity of NCLX because Ca2+activates several enzymes of the Krebs cycle. It is currently believed that mitochondria are not only centers of energy produc-tion but are also important sites of reactive oxygen species (ROS) generation and nucleotide-binding oligomerization domain receptor 3 (NLRP3) inflammasome activation. Methods&Results This study focused on NCLX function, in rat aortic endothelial cells (RAECs), induced by glucose. First, we detected an increase in NCLX expression in the endothelia of rats with diabetes mellitus, which was induced by an injection of streptozotocin. Next, colocalization of NCLX expression and mitochondria was detected using confocal analysis. Suppression of NCLX expression, using an siRNA construct (siNCLX), enhanced mitochondrial Ca2+influx and blocked efflux induced by glucose. Un-expectedly, silencing of NCLX expression induced increased ROS generation and NLRP3 inflammasome activation. Conclusions These findings suggest that NCLX affects glucose-dependent mitochondrial Ca2+signaling, thereby regulating ROS generation and NLRP3 in-flammasome activation in high glucose conditions. In the early stages of high glucose stimulation, NCLX expression increases to compensate in order to self-protect mitochondrial maintenance, stability, and function in endothelial cells.

  11. Mitochondrial emitted electromagnetic signals mediate retrograde signaling.

    Science.gov (United States)

    Bagkos, Georgios; Koufopoulos, Kostas; Piperi, Christina

    2015-12-01

    Recent evidence shows that mitochondria regulate nuclear transcriptional activity both in normal and cell stress conditions, known as retrograde signaling. Under normal mitochondrial function, retrograde signaling is associated with mitochondrial biogenesis, normal cell phenotype and metabolic profile. In contrast, mitochondrial dysfunction leads to abnormal (oncogenic) cell phenotype and altered bio-energetic profile (nucleus reprogramming). Despite intense research efforts, a concrete mechanism through which mitochondria determine the group of genes expressed by the nucleus is still missing. The present paper proposes a novel hypothesis regarding retrograde signaling. More specifically, it reveals the mitochondrial membrane potential (MMP) and the accompanied strong electromagnetic field (EF) as key regulatory factors of nuclear activity. Mitochondrial emitted EFs extend in long distance and affect the function of nuclear membrane receptors. Depending on their frequencies, EFs can directly activate or deactivate different groups of nuclear receptors and so determine nuclear gene expression. One of the key features of the above hypothesis is that nuclear membrane receptors, besides their own endogenous or chemical ligands (hormones, lipids, etc.), can also be activated by electromagnetic signals. Moreover, normal MMP values (about -140 mV) are associated with the production of high ATP quantities and small levels of reactive oxygen species (ROS) while the hyperpolarization observed in all cancer cell types leads to a dramatic fall in ATP production and an analogous increase in ROS. The diminished ATP and increased ROS production negatively affect the function of all cellular systems including nucleus. Restoration of mitochondrial function, which is characterized by the fluctuation of MMP and EF values within a certain (normal) range, is proposed as a necessary condition for normal nuclear function and cancer therapy. PMID:26474928

  12. Mitochondrial transplantation for therapeutic use

    OpenAIRE

    McCully, James Donald; Levitsky, Sidney; del Nido, Pedro J.; Cowan, Douglas Burr

    2016-01-01

    Mitochondria play a key role in the homeostasis of the vast majority of the body’s cells. In the myocardium where mitochondria constitute 30 % of the total myocardial cell volume, temporary attenuation or obstruction of blood flow and as a result oxygen delivery to myocardial cells (ischemia) severely alters mitochondrial structure and function. These alterations in mitochondrial structure and function occur during ischemia and continue after blood flow and oxygen delivery to the myocardium i...

  13. Mitochondrial Proteases as Emerging Pharmacological Targets.

    Science.gov (United States)

    Gibellini, Lara; De Biasi, Sara; Nasi, Milena; Iannone, Anna; Cossarizza, Andrea; Pinti, Marcello

    2016-01-01

    The preservation of mitochondrial function and integrity is critical for cell viability. Under stress conditions, unfolded, misfolded or damaged proteins accumulate in a certain compartment of the organelle, interfering with oxidative phosphorylation and normal mitochondrial functions. In stress conditions, several mechanisms, including mitochondrial unfolded protease response (UPRmt), fusion and fission, and mitophagy are engaged to restore normal proteostasis of the organelle. Mitochondrial proteases are a family of more than 20 enzymes that not only are involved in the UPRmt, but actively participate at multiple levels in the stress-response system. Alterations in their expression levels, or mutations that determine loss or gain of function of these proteases deeply impair mitochondrial functionality and can be associated with the onset of inherited diseases, with the development of neurodegenerative disorders and with the process of carcinogenesis. In this review, we focus our attention on six of them, namely CLPP, HTRA2 and LONP1, by analysing the current knowledge about their functions, their involvement in the pathogenesis of human diseases, and the compounds currently available for inhibiting their functions. PMID:26831646

  14. Cleavage by Caspase 8 and Mitochondrial Membrane Association Activate the BH3-only Protein Bid during TRAIL-induced Apoptosis.

    Science.gov (United States)

    Huang, Kai; Zhang, Jingjing; O'Neill, Katelyn L; Gurumurthy, Channabasavaiah B; Quadros, Rolen M; Tu, Yaping; Luo, Xu

    2016-05-27

    The BH3-only protein Bid is known as a critical mediator of the mitochondrial pathway of apoptosis following death receptor activation. However, since full-length Bid possesses potent apoptotic activity, the role of a caspase-mediated Bid cleavage is not established in vivo In addition, due to the fact that multiple caspases cleave Bid at the same site in vitro, the identity of the Bid-cleaving caspase during death receptor signaling remains uncertain. Moreover, as Bid maintains its overall structure following its cleavage by caspase 8, it remains unclear how Bid is activated upon cleavage. Here, Bid-deficient (Bid KO) colon cancer cells were generated by gene editing, and were reconstituted with wild-type or mutants of Bid. While the loss of Bid blocked apoptosis following treatment by TNF-related apoptosis inducing ligand (TRAIL), this blockade was relieved by re-introduction of the wild-type Bid. In contrast, the caspase-resistant mutant Bid(D60E) and a BH3 defective mutant Bid(G94E) failed to restore TRAIL-induced apoptosis. By generating Bid/Bax/Bak-deficient (TKO) cells, we demonstrated that Bid is primarily cleaved by caspase 8, not by effector caspases, to give rise to truncated Bid (tBid) upon TRAIL treatment. Importantly, despite the presence of an intact BH3 domain, a tBid mutant lacking the mitochondrial targeting helices (α6 and α7) showed diminished apoptotic activity. Together, these results for the first time establish that cleavage by caspase 8 and the subsequent association with the outer mitochondrial membrane are two critical events that activate Bid during death receptor-mediated apoptosis. PMID:27053107

  15. Mitochondrial Defects And Their Role In Development Of Prostate Cancer

    Directory of Open Access Journals (Sweden)

    Nanuli Kotrikadze

    2012-04-01

    Full Text Available Introduction and Objectives: One of the characteristic changes of tumor formation is accumulation of genetic disorders in mitochondrial and nuclear genome. Mitochondrial disorders, from its side, are responsible for failure of metabolism, apoptosis, cell growth, formation of reactive oxygen species, etc. Overprpoduction of reactive oxygen species (ROS significantly impacts the respiration chain enzymes and entirely the antioxidant system of mitochondria. Finally this may become a favorable condition for normal cells transformation.The purpose of the presented work was to study  the mitochondrial defects and to establish their role in prostate cancer development.Results: Experimental results demonstrate significant increase of the activity of mitochondrial succinate dehydrogenaze (complex II of the malignant epithelial cells of prostate, and slight changes in cytochrome oxydase (complex IV activity. Also significant activation of the antioxidant system (glutathione-dependant system of mitochondria in prostate malignant epithelial cells was revealed.Conclusion: The above mentioned mitochondrial changes (II and IV complexes of respiration chain, activity of the antioxidant system partially demonstrate the alterations in mitochondrial energy metabolism, which from its side, may indicate to resistance of prostate cancer cells and correspondingly to intensification of proliferation processes.

  16. Mitochondrial thiol modification by a targeted electrophile inhibits metabolism in breast adenocarcinoma cells by inhibiting enzyme activity and protein levels.

    Science.gov (United States)

    Smith, M Ryan; Vayalil, Praveen K; Zhou, Fen; Benavides, Gloria A; Beggs, Reena R; Golzarian, Hafez; Nijampatnam, Bhavitavya; Oliver, Patsy G; Smith, Robin A J; Murphy, Michael P; Velu, Sadanandan E; Landar, Aimee

    2016-08-01

    Many cancer cells follow an aberrant metabolic program to maintain energy for rapid cell proliferation. Metabolic reprogramming often involves the upregulation of glutaminolysis to generate reducing equivalents for the electron transport chain and amino acids for protein synthesis. Critical enzymes involved in metabolism possess a reactive thiolate group, which can be modified by certain oxidants. In the current study, we show that modification of mitochondrial protein thiols by a model compound, iodobutyl triphenylphosphonium (IBTP), decreased mitochondrial metabolism and ATP in MDA-MB 231 (MB231) breast adenocarcinoma cells up to 6 days after an initial 24h treatment. Mitochondrial thiol modification also depressed oxygen consumption rates (OCR) in a dose-dependent manner to a greater extent than a non-thiol modifying analog, suggesting that thiol reactivity is an important factor in the inhibition of cancer cell metabolism. In non-tumorigenic MCF-10A cells, IBTP also decreased OCR; however the extracellular acidification rate was significantly increased at all but the highest concentration (10µM) of IBTP indicating that thiol modification can have significantly different effects on bioenergetics in tumorigenic versus non-tumorigenic cells. ATP and other adenonucleotide levels were also decreased by thiol modification up to 6 days post-treatment, indicating a decreased overall energetic state in MB231 cells. Cellular proliferation of MB231 cells was also inhibited up to 6 days post-treatment with little change to cell viability. Targeted metabolomic analyses revealed that thiol modification caused depletion of both Krebs cycle and glutaminolysis intermediates. Further experiments revealed that the activity of the Krebs cycle enzyme, aconitase, was attenuated in response to thiol modification. Additionally, the inhibition of glutaminolysis corresponded to decreased glutaminase C (GAC) protein levels, although other protein levels were unaffected. This study

  17. Mitochondrial thiol modification by a targeted electrophile inhibits metabolism in breast adenocarcinoma cells by inhibiting enzyme activity and protein levels

    Directory of Open Access Journals (Sweden)

    M. Ryan Smith

    2016-08-01

    Full Text Available Many cancer cells follow an aberrant metabolic program to maintain energy for rapid cell proliferation. Metabolic reprogramming often involves the upregulation of glutaminolysis to generate reducing equivalents for the electron transport chain and amino acids for protein synthesis. Critical enzymes involved in metabolism possess a reactive thiolate group, which can be modified by certain oxidants. In the current study, we show that modification of mitochondrial protein thiols by a model compound, iodobutyl triphenylphosphonium (IBTP, decreased mitochondrial metabolism and ATP in MDA-MB 231 (MB231 breast adenocarcinoma cells up to 6 days after an initial 24 h treatment. Mitochondrial thiol modification also depressed oxygen consumption rates (OCR in a dose-dependent manner to a greater extent than a non-thiol modifying analog, suggesting that thiol reactivity is an important factor in the inhibition of cancer cell metabolism. In non-tumorigenic MCF-10A cells, IBTP also decreased OCR; however the extracellular acidification rate was significantly increased at all but the highest concentration (10 µM of IBTP indicating that thiol modification can have significantly different effects on bioenergetics in tumorigenic versus non-tumorigenic cells. ATP and other adenonucleotide levels were also decreased by thiol modification up to 6 days post-treatment, indicating a decreased overall energetic state in MB231 cells. Cellular proliferation of MB231 cells was also inhibited up to 6 days post-treatment with little change to cell viability. Targeted metabolomic analyses revealed that thiol modification caused depletion of both Krebs cycle and glutaminolysis intermediates. Further experiments revealed that the activity of the Krebs cycle enzyme, aconitase, was attenuated in response to thiol modification. Additionally, the inhibition of glutaminolysis corresponded to decreased glutaminase C (GAC protein levels, although other protein levels were

  18. Alternative complement pathway and factor B activities in rats with altered blood levels of thyroid hormone

    Energy Technology Data Exchange (ETDEWEB)

    Bitencourt, C.S. [Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP (Brazil); Duarte, C.G.; Azzolini, A.E.C.S.; Assis-Pandochi, A.I. [Departamento de Física e Química, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP (Brazil)

    2012-03-02

    Evaluating the activity of the complement system under conditions of altered thyroid hormone levels might help elucidate the role of complement in triggering autoimmune processes. Here, we investigated alternative pathway (AP) activity in male Wistar rats (180 ± 10 g) after altering their thyroid hormone levels by treatment with triiodothyronine (T3), propylthiouracil (PTU) or thyroidectomy. T3 and thyroxine (T4) levels were determined by chemiluminescence assays. Hemolytic assays were performed to evaluate the lytic activity of the AP. Factor B activity was evaluated using factor B-deficient serum. An anti-human factor B antibody was used to measure factor B levels in serum by radial immunodiffusion. T3 measurements in thyroidectomized animals or animals treated with PTU demonstrated a significant reduction in hormone levels compared to control. The results showed a reduction in AP lytic activity in rats treated with increasing amounts of T3 (1, 10, or 50 µg). Factor B activity was also decreased in the sera of hyperthyroid rats treated with 1 to 50 µg T3. Additionally, treating rats with 25 µg T3 significantly increased factor B levels in their sera (P < 0.01). In contrast, increased factor B concentration and activity (32%) were observed in hypothyroid rats. We conclude that alterations in thyroid hormone levels affect the activity of the AP and factor B, which may in turn affect the roles of AP and factor B in antibody production.

  19. Activation of Hsp90/NOS and increased NO generation does not impair mitochondrial respiratory chain by competitive binding at cytochrome C Oxidase in low oxygen concentrations

    OpenAIRE

    Presley, Tennille; Vedam, Kaushik; Liu, Xiaoping; Zweier, Jay L.; Ilangovan, Govindasamy

    2009-01-01

    Nitric oxide (NO) is known to regulate mitochondrial respiration, especially during metabolic stress and disease, by nitrosation of the mitochondrial electron transport chain (ETC) complexes (irreversible) and by a competitive binding at O2 binding site of cytochrome c oxidase (CcO) in complex IV (reversible). In this study, by using bovine aortic endothelial cells, we demonstrate that the inhibitory effect of endogenously generated NO by nitric oxide synthase (NOS) activation, by either NOS ...

  20. A mitochondrially targeted compound delays aging in yeast through a mechanism linking mitochondrial membrane lipid metabolism to mitochondrial redox biology

    Directory of Open Access Journals (Sweden)

    Michelle T. Burstein

    2014-01-01

    Full Text Available A recent study revealed a mechanism of delaying aging in yeast by a natural compound which specifically impacts mitochondrial redox processes. In this mechanism, exogenously added lithocholic bile acid enters yeast cells, accumulates mainly in the inner mitochondrial membrane, and elicits an age-related remodeling of phospholipid synthesis and movement within both mitochondrial membranes. Such remodeling of mitochondrial phospholipid dynamics progresses with the chronological age of a yeast cell and ultimately causes significant changes in mitochondrial membrane lipidome. These changes in the composition of membrane phospholipids alter mitochondrial abundance and morphology, thereby triggering changes in the age-related chronology of such longevity-defining redox processes as mitochondrial respiration, the maintenance of mitochondrial membrane potential, the preservation of cellular homeostasis of mitochondrially produced reactive oxygen species, and the coupling of electron transport to ATP synthesis.

  1. Analysis of Mitochondrial haemoglobin in Parkinson's disease brain.

    Science.gov (United States)

    Shephard, Freya; Greville-Heygate, Oliver; Liddell, Susan; Emes, Richard; Chakrabarti, Lisa

    2016-07-01

    Mitochondrial dysfunction is an early feature of neurodegeneration. We have shown there are mitochondrial haemoglobin changes with age and neurodegeneration. We hypothesised that altered physiological processes are associated with recruitment and localisation of haemoglobin to these organelles. To confirm a dynamic localisation of haemoglobin we exposed Drosophila melanogaster to cyclical hypoxia with recovery. With a single cycle of hypoxia and recovery we found a relative accumulation of haemoglobin in the mitochondria compared with the cytosol. An additional cycle of hypoxia and recovery led to a significant increase of mitochondrial haemoglobin (pbrains. Relative mitochondrial/cytosolic quantities of haemoglobin were obtained for the cortical region, substantia nigra and cerebellum. In age matched post-mortem brain mitochondrial haemoglobin ratios change, decreasing with disease duration in female cerebellum samples (n=7). The change is less discernible in male cerebellum (n=18). In cerebellar mitochondria, haemoglobin localisation in males with long disease duration shifts from the intermembrane space to the outer membrane of the organelle. These new data illustrate dynamic localisation of mitochondrial haemoglobin within the cell. Mitochondrial haemoglobin should be considered in the context of gender differences characterised in Parkinson's disease. It has been postulated that cerebellar circuitry may be activated to play a protective role in individuals with Parkinson's. The changing localisation of intracellular haemoglobin in response to hypoxia presents a novel pathway to delineate the role of the cerebellum in Parkinson's disease. PMID:27181046

  2. Altered lower leg muscle activation patterns in patients with cerebral palsy during cycling on an ergometer

    Science.gov (United States)

    Alves-Pinto, Ana; Blumenstein, Tobias; Turova, Varvara; Lampe, Renée

    2016-01-01

    Objective Cycling on a recumbent ergometer constitutes one of the most popular rehabilitation exercises in cerebral palsy (CP). However, no control is performed on how muscles are being used during training. Given that patients with CP present altered muscular activity patterns during cycling or walking, it is possible that an incorrect pattern of muscle activation is being promoted during rehabilitation cycling. This study investigated patterns of muscular activation during cycling on a recumbent ergometer in patients with CP and whether those patterns are determined by the degree of spasticity and of mobility. Methods Electromyographic (EMG) recordings of lower leg muscle activation during cycling on a recumbent ergometer were performed in 14 adult patients diagnosed with CP and five adult healthy participants. EMG recordings were done with an eight-channel EMG system built in the laboratory. The activity of the following muscles was recorded: Musculus rectus femoris, Musculus biceps femoris, Musculus tibialis anterior, and Musculus gastrocnemius. The degree of muscle spasticity and mobility was assessed using the Modified Ashworth Scale and the Gross Motor Function Classification System, respectively. Muscle activation patterns were described in terms of onset and duration of activation as well as duration of cocontractions. Results Muscle activation in CP was characterized by earlier onsets, longer periods of activation, a higher occurrence of agonist–antagonist cocontractions, and a more variable cycling tempo in comparison to healthy participants. The degree of altered muscle activation pattern correlated significantly with the degree of spasticity. Conclusion This study confirmed the occurrence of altered lower leg muscle activation patterns in patients with CP during cycling on a recumbent ergometer. There is a need to develop feedback systems that can inform patients and therapists of an incorrect muscle activation during cycling and support the training

  3. Mitochondrial Defects in Breast Cancer

    Directory of Open Access Journals (Sweden)

    Josefa Salgado

    2008-01-01

    Full Text Available Mitochondria play important roles in cellular energy metabolism, free radical generation, and apoptosis. Mitochondrial DNA has been proposed to be involved in carcinogenesis because of its high susceptibility to mutations and limited repair mechanisms in comparison to nuclear DNA. Breast cancer is the most frequent cancer type among women in the world and, although exhaustive research has been done on nuclear DNA changes, several studies describe a variety of mitochondrial DNA alterations present in breast cancer. In this review article, we to provide a summary of the mitochondrial genomic alterations reported in breast cancer and their functional consequences.

  4. Effect of Solanum surattense on mitochondrial enzymes in diabetic rats and in vitro glucose uptake activity in L6 myotubes

    Directory of Open Access Journals (Sweden)

    Muruhan Sridevi

    2015-01-01

    Full Text Available Background: S. surattense is widely used in Siddha medicine for various ailments. Objective: The aim was to evaluate the impact of alcoholic leaf-extract of S. surattense on mitochondrial enzymes in streptozotocin (STZ induced diabetic rats and to study the in vitro muscle glucose uptake activity on L6 myotubes. Materials and Methods: The male albino Wistar rats were randomly divided into five groups of six animals each. Diabetes was induced by intraperitoneal injection of STZ (40 mg/kg body weight. After being confirmed the diabetic rats were treated with alcoholic leaf-extract of S. surattense (100 mg/kg body weight for 45 days. The biochemical estimations (liver mitochondrial enzymes, antioxidants, thiobarbituric acid reactive substances [TBARS] and histopathological studies were performed. Further, the in vitro muscle glucose uptake activity in L6 myotubes and messenger RNA (mRNA expression of glucose transporter-4 (GLUT-4 was performed. Results: In diabetic rats, the activities of liver mitochondrial enzymes were found to be significantly lowered. The mitochondrial TBARS level increased, whereas the activities/level of enzymatic and non-enzymatic antioxidants decreased in diabetic rats. Administration of S. surattense to diabetic rats significantly reversed the above parameters toward normalcy. Furthermore in diabetic rats, the histopathological studies showed growth of adipose tissue and shrinkage of islets in the pancreas, liver showed fatty change with mild inflammation of portal triad, and kidney showed messangial capillary proliferation of glomeruli and fatty infiltration of tubules. Treatment with S. surattense brought back these changes to near normalcy. The extract was analyzed for in vitro muscle glucose uptake activity in L6 myotubes and mRNA expression of GLUT-4 by semi-quantitative reverse transcriptase-polymerase chain reaction. One nano gram per millilitre of S. surattense leaf-extract gave 115% glucose uptake on L6 myotubes

  5. Mitochondrial proteomics on human fibroblasts for identification of metabolic imbalance and cellular stress

    Directory of Open Access Journals (Sweden)

    Bross Peter

    2009-05-01

    Full Text Available Abstract Background Mitochondrial proteins are central to various metabolic activities and are key regulators of apoptosis. Disturbance of mitochondrial proteins is therefore often associated with disease. Large scale protein data are required to capture the mitochondrial protein levels and mass spectrometry based proteomics is suitable for generating such data. To study the relative quantities of mitochondrial proteins in cells from cultivated human skin fibroblasts we applied a proteomic method based on nanoLC-MS/MS analysis of iTRAQ-labeled peptides. Results When fibroblast cultures were exposed to mild metabolic stress – by cultivation in galactose medium- the amount of mitochondria appeared to be maintained whereas the levels of individual proteins were altered. Proteins of respiratory chain complex I and IV were increased together with NAD+-dependent isocitrate dehydrogenase of the citric acid cycle illustrating cellular strategies to cope with altered energy metabolism. Furthermore, quantitative protein data, with a median standard error below 6%, were obtained for the following mitochondrial pathways: fatty acid oxidation, citric acid cycle, respiratory chain, antioxidant systems, amino acid metabolism, mitochondrial translation, protein quality control, mitochondrial morphology and apoptosis. Conclusion The robust analytical platform in combination with a well-defined compendium of mitochondrial proteins allowed quantification of single proteins as well as mapping of entire pathways. This enabled characterization of the interplay between metabolism and stress response in human cells exposed to mild stress.

  6. Activation of mitochondrial STAT-3 and reduced mitochondria damage during hypothermia treatment for post-cardiac arrest myocardial dysfunction.

    Science.gov (United States)

    Huang, Chien-Hua; Tsai, Min-Shan; Chiang, Chih-Yen; Su, Yu-Jen; Wang, Tzung-Dau; Chang, Wei-Tien; Chen, Huei-Wen; Chen, Wen-Jone

    2015-11-01

    While therapeutic hypothermia improves the outcomes of individuals in cardiac arrest, the hemodynamic responses and mechanisms which underlie hypothermia-induced cardioprotection are not fully understood. Therefore, we investigated the mechanism by which induced hypothermia preserves cardiac function and protects against mitochondrial damage following cardiac arrest. Cardiac arrest was induced in adult male Wistar rats by asphyxiation for 8.5 min. Following resuscitation, the animals were randomly assigned to a hypothermia (32 °C) or normothermia (37 °C) group. Monitoring results showed that cardiac output at the fourth hour after resuscitation was significantly better in rats treated with hypothermia when compared to rats treated with normothermia (P < 0.01). Examinations by transmission electron microscopy showed that mitochondria in the left ventricle of rats in the hypothermia group were significantly less swollen compared to such mitochondria in the normothermia group (P < 0.001). Additionally, opening of mitochondrial permeability transition pores occurred less frequently in the hypothermic group. While complex I/III activity in the electron transport reaction was damaged after cardiac arrest and resuscitation, the degree of injury was ameliorated by hypothermia treatment (P < 0.05). The amount of STAT-3 phosphorylated at tyrosine 705 and its expression in mitochondria were significantly higher under hypothermia treatment compared to normothermia treatment. In vitro studies showed that inhibition STAT-3 activation abolished the ability of hypothermia to protect H9C2 cardiomyocytes against injury produced by simulated ischemia and reperfusion. Therapeutic hypothermia treatment can ameliorate cardiac dysfunction and help preserve both mitochondrial integrity and electron transport activity. PMID:26471891

  7. Cutaneous mitochondrial respirometry: non-invasive monitoring of mitochondrial function.

    Science.gov (United States)

    Harms, Floor A; Bodmer, Sander I A; Raat, Nicolaas J H; Mik, Egbert G

    2015-08-01

    The recently developed technique for measuring cutaneous mitochondrial oxygen tension (mitoPO2) by means of the Protoporphyrin IX-Triplet State Lifetime Technique (PpIX-TSLT) provides new opportunities for assessing mitochondrial function in vivo. The aims of this work were to study whether cutaneous mitochondrial measurements reflect mitochondrial status in other parts of the body and to demonstrate the feasibility of the technique for potential clinical use. The first part of this paper demonstrates a correlation between alterations in mitochondrial parameters in skin and other tissues during endotoxemia. Experiments were performed in rats in which mitochondrial dysfunction was induced by a lipopolysaccharide-induced sepsis (n = 5) and a time control group (n = 5). MitoPO2 and mitochondrial oxygen consumption (mitoVO2) were measured using PpIX-TSLT in skin, liver and buccal mucosa of the mouth. Both skin and buccal mucosa show a significant mitoPO2-independent decrease (P paper describes the clinical concept of monitoring cutaneous mitochondrial respiration in man. A first prototype of a clinical PpIX-TSLT monitor is described and its usability is demonstrated on human skin. We expect that clinical implementation of this device will greatly contribute to our understanding of mitochondrial oxygenation and oxygen metabolism in perioperative medicine and in critical illness. Our ultimate goal is to develop a clinical monitor for mitochondrial function and the current results are an important step forward. PMID:25388510

  8. Mitochondrial haplogroups

    DEFF Research Database (Denmark)

    Benn, Marianne; Schwartz, Marianne; Nordestgaard, Børge G;

    2008-01-01

    Rare mutations in the mitochondrial genome may cause disease. Mitochondrial haplogroups defined by common polymorphisms have been associated with risk of disease and longevity. We tested the hypothesis that common haplogroups predict risk of ischemic cardiovascular disease, morbidity from other...

  9. Skeletal muscle plasticity: cellular and molecular responses to altered physical activity paradigms

    Science.gov (United States)

    Baldwin, Kenneth M.; Haddad, Fadia

    2002-01-01

    The goal of this article is to examine our current understanding of the chain of events known to be involved in the adaptive process whereby specific genes and their protein products undergo altered expression; specifically, skeletal muscle adaptation in response to altered loading states will be discussed, with a special focus on the regulation of the contractile protein, myosin heavy chain gene expression. This protein, which is both an important structural and regulatory protein comprising the contractile apparatus, can be expressed as different isoforms, thereby having an impact on the functional diversity of the muscle. Because the regulation of the myosin gene family is under the control of a complex set of processes including, but not limited to, activity, hormonal, and metabolic factors, this protein will serve as a cellular "marker" for studies of muscle plasticity in response to various mechanical perturbations in which the quantity and type of myosin isoform, along with other important cellular proteins, are altered in expression.

  10. Dietary Supplementation with Docosahexaenoic Acid, but Not Eicosapentanoic Acid, Dramatically Alters Cardiac Mitochondrial Phospholipid Fatty Acid Composition and Prevents Permeability Transition

    OpenAIRE

    Khairallah, Ramzi J.; Sparagna, Genevieve C.; Khanna, Nishanth; O’Shea, Karen M.; Hecker, Peter A; Kristian, Tibor; Fiskum, Gary; Rosiers, Christine Des; Polster, Brian M.; Stanley, William C.

    2010-01-01

    Treatment with the ω-3 polyunsaturated fatty acids (PUFAs) docosahexanoic acid (DHA) and eicosapentanoic acid (EPA) exerts cardioprotective effects, and suppresses Ca2+-induced opening of the mitochondrial permeability transition pore (MPTP). These effects are associated with increased DHA and EPA, and lower arachidonic acid (ARA) in cardiac phospholipids. While clinical studies suggest the triglyceride lowering effects of DHA and EPA are equivalent, little is known about the independent effe...

  11. Mitochondrial dysfunction in cancer

    Directory of Open Access Journals (Sweden)

    Kinga Księżakowska-Łakoma

    2014-05-01

    Full Text Available Mitochondria are semi-autonomous organelles of eukaryotic cells. They perform crucial functions such as generating most of the cellular energy through the oxidative phosphorylation (OXPHOS system and some other metabolic processes. In addition, mitochondria are involved in regulation of cell death and reactive oxygen species (ROS generation. Also, mitochondria play important roles in carcinogenesis via altering energy metabolism, resistance to apoptosis, increase of production of ROS and mtDNA (mitochondrial genome changes. Studies have suggested that aerobic glycolysis is high in malignant tumors. Probably, it correlates with high glucose intake of cancerous tissues. This observation is contrary to Warburg’s theory that the main way of energy generation in cancer cells is non-oxidative glycolysis. Further studies have suggested that in tumor cells both oxidative phosphorylation and glycolysis were active at various rates. An increase of intracellular oxidative stress induces damage of cellular structure and somatic mutations. Further studies confirmed that permanent activity of oxidative stress and the influence of chronic inflammation damage the healthy neighboring epithelium and may lead to carcinogenesis. For instance, chronic inflammato­ry bowel disease could be related to high risk of colon adenocarcinoma. The data have shown a role of ROS generation, mtDNA or nDNA alterations and abnormal apoptotic machinery in endometrial cancer progress. Recent studies suggest that mtDNA mutations might play a potential role in endometrial cancer progress and indicate an increase of mitochondrial biogenesis in this cancer. The investigators suggested that MtCOI and MtND6 alteration has an influence on assembly of respiratory complexes in endometrial cancer. In many human cancers, there is a deregulation of the balance between cell growth and death. The tumor cells can avoid apoptosis through a loss of balance between anti- and pro

  12. Mitochondrial phospholipase A2 activated by reactive oxygen species in heart mitochondria induces mild uncoupling

    Czech Academy of Sciences Publication Activity Database

    Ježek, Jan; Jabůrek, Martin; Zelenka, Jaroslav; Ježek, Petr

    2010-01-01

    Roč. 59, č. 5 (2010), s. 737-747. ISSN 0862-8408 R&D Projects: GA ČR(CZ) GA303/07/0105; GA MŠk ME09018; GA AV ČR(CZ) KJB500110902 Institutional research plan: CEZ:AV0Z50110509 Keywords : Heart mitochondrial phospholipase A2 * Fatty Acids * Adenine nucleotide translocase Subject RIV: ED - Physiology Impact factor: 1.646, year: 2010

  13. Alterations in the activity and structure of pectin methylesterase treated by high pressure carbon dioxide.

    Science.gov (United States)

    Zhou, Linyan; Wu, Jihong; Hu, Xiaosong; Zhi, Xian; Liao, Xiaojun

    2009-03-11

    The influence of high pressure carbon dioxide (HPCD) on the activity and structure of pectin methylesterase (PME) from orange was investigated. The pressures were 8-30 MPa, temperature 55 degrees C and time 10 min. HPCD caused significant inactivation on PME, the lowest residual activity was about 9.3% at 30 MPa. The SDS-PAGE electrophoretic behavior of HPCD-treated PME was not altered, while changes in the secondary and tertiary structures were found. The beta-structure fraction in the secondary structure decreased and the fluorescence intensity increased as HPCD pressures were elevated. After 7-day storage at 4 degrees C, no alteration of its activity and no reversion of its beta-structure fraction were observed, while its fluorescence intensity further decreased. PMID:19256556

  14. Mitochondrial activity, hemocyte parameters and lipid composition modulation by dietary conditioning in the Pacific oyster Crassostrea gigas.

    Science.gov (United States)

    Dudognon, Tony; Lambert, Christophe; Quere, Claudie; Auffret, Michel; Soudant, Philippe; Kraffe, Edouard

    2014-04-01

    Several parameters can affect membrane lipid composition in bivalves, including diet. Although two fatty acids (FA) 22:6n-3 and 20:5n-3 are essential membrane components, they are sparingly synthesized by bivalves and must be obtained from their diet. Here, effects of dietary modifications of membrane lipid composition were studied at both cellular and subcellular levels in the oyster Crassostrea gigas. To this end, we compared oysters fed two monoalgal diets that differed markedly in their FA composition and a mix of both. As expected, algae impacted phospholipids, in particular 22:6n-3 and 20:5n-3, reflecting differences of dietary microalgae FA composition. Meantime, total saturated FA, total monounsaturated FA, total polyunsaturated FA and total non-methylene-interrupted FA varied little and phospholipid class composition was only slightly affected by diets. Measures made in hemocytes indicated that only mitochondrial membrane potential was affected by diets. Total ROS production as well as mitochondrial superoxide production did not differ with diet. There was no difference in phosphorylating (state 3) and non-phosphorylating (state 4) rates of oxygen consumption rates or in cytochrome c oxidase activity of mitochondria isolated from gills between the three diets. Similarly, neither cytochromes a, b, c or c1 content nor citrate synthase activities were changed, suggesting that number and morphology of mitochondria were not affected by dietary treatment. These results suggest that oysters could possess high homeostatic capabilities, at both cellular and subcellular levels, to minimize the effect of dietary FA and related membrane lipid FA modifications on mitochondrial functions. These capabilities could be a means to face variations in diet composition in their natural environment and to preserve important oyster physiological functions such as growth and reproduction. PMID:24441864

  15. Quantification of active mitochondrial permeability transition pores using GNX-4975 inhibitor titrations provides insights into molecular identity.

    Science.gov (United States)

    Richardson, Andrew P; Halestrap, Andrew P

    2016-05-01

    Inhibition of the mitochondrial permeability transition pore (MPTP) by the novel inhibitor GNX-4975 was characterized. Titration of MPTP activity in de-energized rat liver mitochondria allowed determination of the number of GNX-4975-binding sites and their dissociation constant (Ki). Binding sites increased in number when MPTP opening was activated by increasing [Ca(2+)], phenylarsine oxide (PAO) or KSCN, and decreased when MPTP opening was inhibited with bongkrekic acid (BKA) or ADP. Values ranged between 9 and 50 pmol/mg of mitochondrial protein, but the Ki remained unchanged at ∼1.8 nM when the inhibitor was added before Ca(2+) However, when GNX-4975 was added after Ca(2+) it was much less potent with a Ki of ∼140 nM. These data imply that a protein conformational change is required to form the MPTP complex and generate the GNX-4975-binding site. Occupation of the latter with GNX-4975 prevents the Ca(2+) binding that triggers pore opening. We also demonstrated that GNX-4975 stabilizes an interaction between the adenine nucleotide translocase (ANT), held in its 'c' conformation with carboxyatractyloside (CAT), and the phosphate carrier (PiC) bound to immobilized PAO. No components of the F1Fo-ATP synthase bound significantly to immobilized PAO. Our data are consistent with our previous proposal that the MPTP may form at an interface between the PiC and ANT (or other similar mitochondrial carrier proteins) when they adopt novel conformations induced by factors that sensitize the MPTP to [Ca(2+)]. We propose that GNX-4975 binds to this interface preventing a calcium-triggered event that opens the interface into a pore. PMID:26920024

  16. Prenatal immune activation alters hippocampal place cell firing characteristics in adult animals.

    Science.gov (United States)

    Wolff, Amy R; Bilkey, David K

    2015-08-01

    Prenatal maternal immune activation (MIA) is a risk factor for several developmental neuropsychiatric disorders, including autism, bipolar disorder and schizophrenia. Adults with these disorders display alterations in memory function that may result from changes in the structure and function of the hippocampus. In the present study we use an animal model to investigate the effect that a transient prenatal maternal immune activation episode has on the spatially-modulated firing activity of hippocampal neurons in adult animals. MIA was induced in pregnant rat dams with a single injection of the synthetic cytokine inducer polyinosinic:polycytidylic acid (poly I:C) on gestational day 15. Control dams were given a saline equivalent. Firing activity and local field potentials (LFPs) were recorded from the CA1 region of the adult male offspring of these dams as they moved freely in an open arena. Most neurons displayed characteristic spatially-modulated 'place cell' firing activity and while there was no between-group difference in mean firing rate between groups, place cells had smaller place fields in MIA-exposed animals when compared to control-group cells. Cells recorded in MIA-group animals also displayed an altered firing-phase synchrony relationship to simultaneously recorded LFPs. When the floor of the arena was rotated, the place fields of MIA-group cells were more likely to shift in the same direction as the floor rotation, suggesting that local cues may have been more salient for these animals. In contrast, place fields in control group cells were more likely to shift firing position to novel spatial locations suggesting an altered response to contextual cues. These findings show that a single MIA intervention is sufficient to change several important characteristics of hippocampal place cell activity in adult offspring. These changes could contribute to the memory dysfunction that is associated with MIA, by altering the encoding of spatial context and by

  17. BAY 87-2243, a highly potent and selective inhibitor of hypoxia-induced gene activation has antitumor activities by inhibition of mitochondrial complex I

    International Nuclear Information System (INIS)

    The activation of the transcription factor hypoxia-inducible factor-1 (HIF-1) plays an essential role in tumor development, tumor progression, and resistance to chemo- and radiotherapy. In order to identify compounds targeting the HIF pathway, a small molecule library was screened using a luciferase-driven HIF-1 reporter cell line under hypoxia. The high-throughput screening led to the identification of a class of aminoalkyl-substituted compounds that inhibited hypoxia-induced HIF-1 target gene expression in human lung cancer cell lines at low nanomolar concentrations. Lead structure BAY 87-2243 was found to inhibit HIF-1α and HIF-2α protein accumulation under hypoxic conditions in non-small cell lung cancer (NSCLC) cell line H460 but had no effect on HIF-1α protein levels induced by the hypoxia mimetics desferrioxamine or cobalt chloride. BAY 87-2243 had no effect on HIF target gene expression levels in RCC4 cells lacking Von Hippel–Lindau (VHL) activity nor did the compound affect the activity of HIF prolyl hydroxylase-2. Antitumor activity of BAY 87-2243, suppression of HIF-1α protein levels, and reduction of HIF-1 target gene expression in vivo were demonstrated in a H460 xenograft model. BAY 87-2243 did not inhibit cell proliferation under standard conditions. However under glucose depletion, a condition favoring mitochondrial ATP generation as energy source, BAY 87-2243 inhibited cell proliferation in the nanomolar range. Further experiments revealed that BAY 87-2243 inhibits mitochondrial complex I activity but has no effect on complex III activity. Interference with mitochondrial function to reduce hypoxia-induced HIF-1 activity in tumors might be an interesting therapeutic approach to overcome chemo- and radiotherapy-resistance of hypoxic tumors

  18. Mitochondrial functions modulate neuroendocrine, metabolic, inflammatory, and transcriptional responses to acute psychological stress.

    Science.gov (United States)

    Picard, Martin; McManus, Meagan J; Gray, Jason D; Nasca, Carla; Moffat, Cynthia; Kopinski, Piotr K; Seifert, Erin L; McEwen, Bruce S; Wallace, Douglas C

    2015-12-01

    The experience of psychological stress triggers neuroendocrine, inflammatory, metabolic, and transcriptional perturbations that ultimately predispose to disease. However, the subcellular determinants of this integrated, multisystemic stress response have not been defined. Central to stress adaptation is cellular energetics, involving mitochondrial energy production and oxidative stress. We therefore hypothesized that abnormal mitochondrial functions would differentially modulate the organism's multisystemic response to psychological stress. By mutating or deleting mitochondrial genes encoded in the mtDNA [NADH dehydrogenase 6 (ND6) and cytochrome c oxidase subunit I (COI)] or nuclear DNA [adenine nucleotide translocator 1 (ANT1) and nicotinamide nucleotide transhydrogenase (NNT)], we selectively impaired mitochondrial respiratory chain function, energy exchange, and mitochondrial redox balance in mice. The resulting impact on physiological reactivity and recovery from restraint stress were then characterized. We show that mitochondrial dysfunctions altered the hypothalamic-pituitary-adrenal axis, sympathetic adrenal-medullary activation and catecholamine levels, the inflammatory cytokine IL-6, circulating metabolites, and hippocampal gene expression responses to stress. Each mitochondrial defect generated a distinct whole-body stress-response signature. These results demonstrate the role of mitochondrial energetics and redox balance as modulators of key pathophysiological perturbations previously linked to disease. This work establishes mitochondria as stress-response modulators, with implications for understanding the mechanisms of stress pathophysiology and mitochondrial diseases. PMID:26627253

  19. The mitochondrial fusion-promoting factor mitofusin is a substrate of the PINK1/parkin pathway.

    Directory of Open Access Journals (Sweden)

    Angela C Poole

    Full Text Available Loss-of-function mutations in the PINK1 or parkin genes result in recessive heritable forms of parkinsonism. Genetic studies of Drosophila orthologs of PINK1 and parkin indicate that PINK1, a mitochondrially targeted serine/threonine kinase, acts upstream of Parkin, a cytosolic ubiquitin-protein ligase, to promote mitochondrial fragmentation, although the molecular mechanisms by which the PINK1/Parkin pathway promotes mitochondrial fragmentation are unknown. We tested the hypothesis that PINK1 and Parkin promote mitochondrial fragmentation by targeting core components of the mitochondrial morphogenesis machinery for ubiquitination. We report that the steady-state abundance of the mitochondrial fusion-promoting factor Mitofusin (dMfn is inversely correlated with the activity of PINK1 and Parkin in Drosophila. We further report that dMfn is ubiquitinated in a PINK1- and Parkin-dependent fashion and that dMfn co-immunoprecipitates with Parkin. By contrast, perturbations of PINK1 or Parkin did not influence the steady-state abundance of the mitochondrial fission-promoting factor Drp1 or the mitochondrial fusion-promoting factor Opa1, or the subcellular distribution of Drp1. Our findings suggest that dMfn is a direct substrate of the PINK1/Parkin pathway and that the mitochondrial morphological alterations and tissue degeneration phenotypes that derive from mutations in PINK1 and parkin result at least in part from reduced ubiquitin-mediated turnover of dMfn.

  20. Depleted skeletal muscle mitochondrial DNA, hyperlactatemia, and decreased oxidative capacity in HIV-infected patients on highly active antiretroviral therapy

    DEFF Research Database (Denmark)

    Haugaard, Steen B; Andersen, Ove; Pedersen, Steen B;

    2005-01-01

    The nucleoside reverse transcriptase inhibitors (NRTIs), especially stavudine, may deplete mitochondrial (mt) DNA in human tissues by inhibiting the mitochondrial polymerase gamma, a setting, which is associated with hyperlactatemia. The aim of the present study was to examine whether...

  1. Synthesis and biological evaluation in mice of (2-[11C]methoxy)-6',7'-dihydrorotenol, a second generation rotenoid for marking mitochondrial complex I activity

    International Nuclear Information System (INIS)

    Evidence has accumulated suggesting that impairment of the function of the complexes of the mitochondrial respiratory chain might be involved in the pathology of neurological diseases including Parkinson's and Huntington's diseases. Recently we reported the synthesis of (2-[11C]methoxy)rotenone ([11C]ROT) as a tool for in vivo studies of complex I. In an effort to develop a complex I imaging radiotracer which might be easier to synthesize and less likely to be metabolized, we prepared (2-[11C]methoxy)-6',7'-dihydrorotenol ([11C]DHROT). The radiotracer was synthesized by [11C]methylation of 2-O-desmethyl-6',7'-dihydrorotenol under basic [11C]alkylation conditions. (2-[11C]Methoxy)-6',7'-dihydrorotenol was produced in 30-35% radiochemical yields (decay corrected), with synthesis times shorter than 35 min. Radiochemical purities were over 95% and specific activities averaged 1000 Ci/mmol. The brain distributions of [11C]ROT and [11C]DHROT were investigated in mice after intravenous injections. For both radiotracers, distribution of radioactivity was similar in all brain regions examined. However, significantly higher uptake was observed with [11C]DHROT than with [11C]ROT, indicating that the alterations introduced in the structure of rotenone during the design of [11C]DHROT resulted in a tracer with greater brain barrier permeability

  2. Metformin-induced inhibition of the mitochondrial respiratory chain increases FGF21 expression via ATF4 activation

    International Nuclear Information System (INIS)

    Highlights: •Metformin induces FGF21 expression in an AMPK independent manner. •Metformin enhances FGF21 expression by inhibiting mitochondrial complex I activity. •The PERK-eIF2α-ATF4 axis is required for metformin-induced FGF21 expression. •Metformin activates the ATF4-FGF21 axis in the liver of mouse. •Metformin increases serum FGF21 level in diabetic human subjects. -- Abstract: Fibroblast growth factor 21 (FGF21) is an endocrine hormone that exhibits anti-obesity and anti-diabetes effects. Because metformin is widely used as a glucose-lowering agent in patients with type 2 diabetes (T2D), we investigated whether metformin modulates FGF21 expression in cell lines, and in mice or human subjects. We found that metformin increased the expression and release of FGF21 in a diverse set of cell types, including rat hepatoma FaO, primary mouse hepatocytes, and mouse embryonic fibroblasts (MEFs). Intriguingly, AMP-activated protein kinase (AMPK) was dispensable for the induction of FGF21 by metformin. Mammalian target of rapamycin complex 1 (mTORC1) and peroxisome proliferator-activated receptor α (PPARα), which are additional targets of metformin, were not involved in metformin-induced FGF21 expression. Importantly, inhibition of mitochondrial complex I activity by metformin resulted in FGF21 induction through PKR-like ER kinase (PERK)-eukaryotic translation factor 2α (eIF2α)-activating transcription factor 4 (ATF4). We showed that metformin activated ATF4 and increased FGF21 expression in the livers of mice, which led to increased serum levels of FGF21. We also found that serum FGF21 level was increased in human subjects with T2D after metformin therapy for 6 months. In conclusion, our results indicate that metformin induced expression of FGF21 through an ATF4-dependent mechanism by inhibiting mitochondrial respiration independently of AMPK. Therefore, FGF21 induction by metformin might explain a portion of the beneficial metabolic effects of metformin

  3. Metformin-induced inhibition of the mitochondrial respiratory chain increases FGF21 expression via ATF4 activation

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kook Hwan [Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Irwon-dong Gangnam-gu, Seoul 135-710 (Korea, Republic of); Samsung Advanced Institute for Health Sciences and Technology, Sungkyunkwan University School of Medicine, 50 Irwon-dong Gangnam-gu, Seoul 135-710 (Korea, Republic of); Jeong, Yeon Taek [Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Irwon-dong Gangnam-gu, Seoul 135-710 (Korea, Republic of); Kim, Seong Hun [Samsung Advanced Institute for Health Sciences and Technology, Sungkyunkwan University School of Medicine, 50 Irwon-dong Gangnam-gu, Seoul 135-710 (Korea, Republic of); Jung, Hye Seung; Park, Kyong Soo [Department of Internal Medicine, Seoul National University College of Medicine, 28 Yongon-dong Chongno-gu, Seoul 110-744 (Korea, Republic of); Lee, Hae-Youn [Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Irwon-dong Gangnam-gu, Seoul 135-710 (Korea, Republic of); Lee, Myung-Shik, E-mail: mslee0923@skku.edu [Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Irwon-dong Gangnam-gu, Seoul 135-710 (Korea, Republic of); Samsung Advanced Institute for Health Sciences and Technology, Sungkyunkwan University School of Medicine, 50 Irwon-dong Gangnam-gu, Seoul 135-710 (Korea, Republic of)

    2013-10-11

    Highlights: •Metformin induces FGF21 expression in an AMPK independent manner. •Metformin enhances FGF21 expression by inhibiting mitochondrial complex I activity. •The PERK-eIF2α-ATF4 axis is required for metformin-induced FGF21 expression. •Metformin activates the ATF4-FGF21 axis in the liver of mouse. •Metformin increases serum FGF21 level in diabetic human subjects. -- Abstract: Fibroblast growth factor 21 (FGF21) is an endocrine hormone that exhibits anti-obesity and anti-diabetes effects. Because metformin is widely used as a glucose-lowering agent in patients with type 2 diabetes (T2D), we investigated whether metformin modulates FGF21 expression in cell lines, and in mice or human subjects. We found that metformin increased the expression and release of FGF21 in a diverse set of cell types, including rat hepatoma FaO, primary mouse hepatocytes, and mouse embryonic fibroblasts (MEFs). Intriguingly, AMP-activated protein kinase (AMPK) was dispensable for the induction of FGF21 by metformin. Mammalian target of rapamycin complex 1 (mTORC1) and peroxisome proliferator-activated receptor α (PPARα), which are additional targets of metformin, were not involved in metformin-induced FGF21 expression. Importantly, inhibition of mitochondrial complex I activity by metformin resulted in FGF21 induction through PKR-like ER kinase (PERK)-eukaryotic translation factor 2α (eIF2α)-activating transcription factor 4 (ATF4). We showed that metformin activated ATF4 and increased FGF21 expression in the livers of mice, which led to increased serum levels of FGF21. We also found that serum FGF21 level was increased in human subjects with T2D after metformin therapy for 6 months. In conclusion, our results indicate that metformin induced expression of FGF21 through an ATF4-dependent mechanism by inhibiting mitochondrial respiration independently of AMPK. Therefore, FGF21 induction by metformin might explain a portion of the beneficial metabolic effects of metformin.

  4. A polysaccharide from pumpkin induces apoptosis of HepG2 cells by activation of mitochondrial pathway.

    Science.gov (United States)

    Shen, Weixi; Guan, Yuanyuan; Wang, Jingfang; Hu, Yu; Tan, Qian; Song, Xiaowei; Jin, Yinghua; Liu, Ying; Zhang, Yanqiao

    2016-04-01

    Purified white polysaccharide (PPW) is a homogenous polysaccharide isolated from pumpkin, with an average molecular weight of 34 kDa. In this study, we aimed at examining the anti-proliferative activity of PPW against hepatocellular carcinoma (HCC) HepG2 cells and the underlying mechanisms. We found that PPW-induced inhibition of cell proliferation in HepG2 cells was associated with the induction of apoptosis. Exposure of HepG2 cells to PPW (100, 200, and 400 μg/mL) resulted in a loss of mitochondrial membrane potential (Δψm) and the release of cytochrome c from the mitochondria to the cytosol. Also, Western blot analysis revealed dose-dependent increase of pro-apoptotic Bax protein and decrease of anti-apoptotic Bcl-2 protein in PPW-treated cells. Besides, caspase-9 and caspase-3 activities were also enhanced in HepG2 cells followed by PPW treatment. Additionally, the cleavage of poly (ADP-ribose) polymerase (PARP) was observed in PPW-treated HepG2 cells, which altogether account for apoptotic cell death. These results suggested that PPW-induced apoptosis involved a caspase-3-mediated mitochondrial pathway and may have potential as a cancer chemopreventive and therapeutic agent for the prevention and treatment of HCC. PMID:26555544

  5. Fecal Protease Activity Is Associated with Compositional Alterations in the Intestinal Microbiota

    OpenAIRE

    Carroll, Ian M.; Ringel-Kulka, Tamar; Ferrier, Laurent; Wu, Michael C.; Siddle, Jennica P.; Bueno, Lionel; Ringel, Yehuda

    2013-01-01

    Objective: Intestinal proteases carry out a variety of functions in the gastrointestinal (GI) tract. Studies have reported that elevated enteric proteases in patients with GI disease can alter intestinal physiology, however the origin (human vs. microbial) of elevated proteases in patients with GI disease is unclear. Aim: The aim of this study was to investigate the association between protease activity and the microbiota in human fecal samples. Design: In order to capture a wide range of fec...

  6. Neutrophil elastase cleaves VEGF to generate a VEGF fragment with altered activity

    OpenAIRE

    Kurtagic, Elma; Jedrychowski, Mark P.; Nugent, Matthew A.

    2009-01-01

    Excessive neutrophil elastase (NE) activity and altered vascular endothelial growth factor (VEGF) signaling have independently been implicated in the development and progression of pulmonary emphysema. In the present study, we investigated the potential link between NE and VEGF. We noted that VEGF165 is a substrate for NE. Digestion of purified VEGF165 with NE generated a partially degraded disulfide-linked fragment of VEGF. Mass spectrometric analysis revealed that NE likely cleaves VEGF165 ...

  7. Alteration and modulation of protein activity by varying post-translational modification

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, David N.; Reed, David W.; Thompson, Vicki S.; Lacey, Jeffrey A.; Apel, William A.

    2016-07-12

    Embodiments of the invention include methods of altering the enzymatic activity or solubility of an extremophilic enzyme or post-translationally modifying a protein of interest via using isolated or partially purified glycosyltransferases and/or post-translational modification proteins, extracts of cells comprising glycosyltransferases and/or post-translational modification proteins, and/or in cells comprising one or more glycosyltransferases and/or post-translational modification proteins.

  8. Social technology restriction alters state-anxiety but not autonomic activity in humans

    OpenAIRE

    Durocher, John J.; Lufkin, Kelly M.; King, Michelle E.; Carter, Jason R.

    2011-01-01

    Social technology is extensively used by young adults throughout the world, and it has been suggested that interrupting access to this technology induces anxiety. However, the influence of social technology restriction on anxiety and autonomic activity in young adults has not been formally examined. Therefore, we hypothesized that restriction of social technology would increase state-anxiety and alter neural cardiovascular regulation of arterial blood pressure. Twenty-one college students (ag...

  9. Alterations in Neuronal Activity in Basal Ganglia-Thalamocortical Circuits in the Parkinsonian State

    Directory of Open Access Journals (Sweden)

    Adriana Galvan

    2015-02-01

    Full Text Available In patients with Parkinson’s disease and in animal models of this disorder, neurons in the basal ganglia and related regions in thalamus and cortex show changes that can be recorded by using electrophysiologic single-cell recording techniques, including altered firing rates and patterns, pathologic oscillatory activity and increased inter-neuronal synchronization. In addition, changes in synaptic potentials or in the joint spiking activities of populations of neurons can be monitored as alterations in local field potentials, electroencephalograms or electrocorticograms. Most of the mentioned electrophysiologic changes are probably related to the degeneration of diencephalic dopaminergic neurons, leading to dopamine loss in the striatum and other basal ganglia nuclei, although degeneration of non-dopaminergic cell groups may also have a role. The altered electrical activity of the basal ganglia and associated nuclei may contribute to some of the motor signs of the disease. We here review the current knowledge of the electrophysiologic changes at the single cell level, the level of local populations of neural elements, and the level of the entire basal ganglia-thalamocortical network in parkinsonism, and discuss the possible use of this information to optimize treatment approaches to Parkinson’s disease, such as deep brain stimulation therapy.

  10. Alteration related to hydrothermal activity of the Nevado del Ruiz volcano (NRV), Colombia

    International Nuclear Information System (INIS)

    The hydrothermal activity in the NRV generates alteration characterized by mineral associations depending one number of physic-chemical factors of the hydrothermal system. Petrography of unaltered rocks was used to establish the mineral assemblage prior to rock-fluid interaction. XRD was used in altered rocks, where it was not possible to recognize the alteration products. the observed mineral assemblages indicate advanced and intermediate argillic alterations, this and the observation of very low modal proportion of sulphates, sulphides and native sulphur in some areas could point to a low sulphidation zone. However, the proximity to the volcano and the presence of acid thermal waters and steam pose an apparent contradiction with an expected high sulphidation zone which is explained by climatic conditions, where excess water has dissolved and leached sulfides, sulphur and sulphates close to the volcano. fault zones serve as conducts for fluid transport and have acid-sulphate mineral associations produced by atmospheric oxidation at the water table in a steam-heated environment of H2S released by deeper, boiling fluids or by the disproportionation of magmatic SO2 to H2S and H2SO4 during condensation of magmatic vapor plume at intermedia depths in magmatic hydrothermal environment in andesitic volcanic terrain characteristic of high sulphidation zones.

  11. Mitochondrial vasculopathy

    Science.gov (United States)

    Finsterer, Josef; Zarrouk-Mahjoub, Sinda

    2016-01-01

    Mitochondrial disorders (MIDs) are usually multisystem disorders (mitochondrial multiorgan disorder syndrome) either on from onset or starting at a point during the disease course. Most frequently affected tissues are those with a high oxygen demand such as the central nervous system, the muscle, endocrine glands, or the myocardium. Recently, it has been shown that rarely also the arteries may be affected (mitochondrial arteriopathy). This review focuses on the type, diagnosis, and treatment of mitochondrial vasculopathy in MID patients. A literature search using appropriate search terms was carried out. Mitochondrial vasculopathy manifests as either microangiopathy or macroangiopathy. Clinical manifestations of mitochondrial microangiopathy include leukoencephalopathy, migraine-like headache, stroke-like episodes, or peripheral retinopathy. Mitochondrial macroangiopathy manifests as atherosclerosis, ectasia of arteries, aneurysm formation, dissection, or spontaneous rupture of arteries. The diagnosis relies on the documentation and confirmation of the mitochondrial metabolic defect or the genetic cause after exclusion of non-MID causes. Treatment is not at variance compared to treatment of vasculopathy due to non-MID causes. Mitochondrial vasculopathy exists and manifests as micro- or macroangiopathy. Diagnosing mitochondrial vasculopathy is crucial since appropriate treatment may prevent from severe complications. PMID:27231520

  12. Mitochondrial energy metabolism impairment and liver dysfunction following chronic exposure to dichlorvos

    International Nuclear Information System (INIS)

    Although the effects of acute pesticide poisoning are well known but, hardly any data exists regarding the health effects after long-term low-level exposure. Major unresolved issues include the effect of moderate exposure in the absence of poisoning. The present study elucidates a possible mechanism by which chronic organophosphate exposure (dichlorvos 6 mg/kg b.wt., s.c. for 12 weeks) causes liver dysfunction. Mitochondria, a primary site of cellular energy generation and oxygen consumption represent a likely target for organophosphate poisoning. Therefore, the objective of the current study was planned with an aim to investigate the effect of chronic dichlorvos exposure on liver mitochondrial electron transport chain (ETC), mitochondrial calcium uptake and its implications on the induction of liver enzymes and liver dysfunction in rodent model. Our results indicated decreased mitochondrial electron transfer activities of cytochrome oxidase along with altered mitochondrial complexes I and II activity. This decrease in the activities of electron transport complexes in turn affected the ATP synthesis and ATP levels adversely in the mitochondria isolated from dichlorvos (DDVP) treated rat liver. Mitochondrial preparation from DDVP treated rat liver demonstrated significant increase in mitochondrial Ca2+ uptake and increase ROS levels. The alterations in the mitochondrial calcium uptake, mitochondrial electron transfer enzyme activities and increase ROS levels in turn might have caused an increase in liver enzymes (ALT, AST and ALP). The electron micrographs of liver cells depicted morphological changes in mitochondria as well as nucleus following 12 weeks of exposure to DDVP. These studies provide an evidence of impaired mitochondrial bioenergetics which may lead to liver dysfunction after chronic exposure to dichlorvos.

  13. Alteration of human hepatic drug transporter activity and expression by cigarette smoke condensate.

    Science.gov (United States)

    Sayyed, Katia; Vee, Marc Le; Abdel-Razzak, Ziad; Jouan, Elodie; Stieger, Bruno; Denizot, Claire; Parmentier, Yannick; Fardel, Olivier

    2016-07-01

    Smoking is well-known to impair pharmacokinetics, through inducing expression of drug metabolizing enzymes. In the present study, we demonstrated that cigarette smoke condensate (CSC) also alters activity and expression of hepatic drug transporters, which are now recognized as major actors of hepatobiliary elimination of drugs. CSC thus directly inhibited activities of sinusoidal transporters such as OATP1B1, OATP1B3, OCT1 and NTCP as well as those of canalicular transporters like P-glycoprotein, MRP2, BCRP and MATE1, in hepatic transporters-overexpressing cells. CSC similarly counteracted constitutive OATP, NTCP and OCT1 activities in human highly-differentiated hepatic HepaRG cells. In parallel, CSC induced expression of BCRP at both mRNA and protein level in HepaRG cells, whereas it concomitantly repressed mRNA expression of various transporters, including OATP1B1, OATP2B1, OAT2, NTCP, OCT1 and BSEP, and enhanced that of MRP4. Such changes in transporter gene expression were found to be highly correlated to those caused by 2,3,7,8-tetrachlorodibenzo-p-dioxin, a reference activator of the aryl hydrocarbon receptor (AhR) pathway, and were counteracted, for some of them, by siRNA-mediated AhR silencing. This suggests that CSC alters hepatic drug transporter levels via activation of the AhR cascade. Importantly, drug transporter expression regulations as well as some transporter activity inhibitions occurred for a range of CSC concentrations similar to those required for inducing drug metabolizing enzymes and may therefore be hypothesized to be relevant for smokers. Taken together, these data established human hepatic transporters as targets of cigarette smoke, which could contribute to known alteration of pharmacokinetics and some liver adverse effects caused by smoking. PMID:27450509

  14. Alterations of RNA Editing for the Mitochondrial ATP9 Gene in a New orf220-type Cytoplasmic Male-sterile Line of Stem Mustard (Brassica juncea var. tumida)

    Institute of Scientific and Technical Information of China (English)

    Jing-Hua Yang; Ming-Fang Zhang; Jing-Quan Yu

    2007-01-01

    RNA editing for the mitochondrial ATP9 gene of encoding regions has been observed in both cytoplasmic malesterile and maintainer lines of stem mustard, where its editing capacity varied spatially and temporally in the cytoplasmic male sterility (CMS) line. There were four RNA editing sites for the mitochondrial ATP9 gene according to its normal editing sites in mustard, of which three sites occurred as C-to-U changes and one as a U-to-C change.As a result, the hydrophobicity of deduced ATP9 protein was reduced due to the conversions at its 17th, 45th and 64th positions. Meanwhile, the conservation of deduced ATP9 protein was enhanced by changes at the 56th position.Loss of a specific editing site for ATP9 was observed in juvenile roots, senile roots, senile leaves and floret buds of the CMS line. Comparatively, complete RNA editing for ATP9 gene was retained in juvenile roots, juvenile leaves and floret buds of its maintainer line; however, the loss of a specific editing site for ATP9 gene occurred at senile roots and senile leaves in its maintainer line. These observations allow us to produce a hypothesis that the dysfunction of a specific mitochondrisl gene arising from RNA editing could probably be a factor triggering CMS and organ senescence through unknown cross-talk pathways during development.

  15. Melanoma-derived factors alter the maturation and activation of differentiated tissue-resident dendritic cells.

    Science.gov (United States)

    Hargadon, Kristian M; Bishop, Johnathan D; Brandt, John P; Hand, Zachary C; Ararso, Yonathan T; Forrest, Osric A

    2016-01-01

    Dendritic cells (DCs) are key regulators of host immunity that are capable of inducing either immune tolerance or activation. In addition to their well-characterized role in shaping immune responses to foreign pathogens, DCs are also known to be critical for the induction and maintenance of anti-tumor immune responses. Therefore, it is important to understand how tumors influence the function of DCs and the quality of immune responses they elicit. Although the majority of studies in this field to date have utilized either immortalized DC lines or DC populations that have been generated under artificial conditions from hematopoietic precursors in vitro, we wished to investigate how tumors impact the function of already differentiated, tissue-resident DCs. Therefore, we used both an ex vivo and in vivo model system to assess the influence of melanoma-derived factors on DC maturation and activation. In ex vivo studies with freshly isolated splenic DCs, we demonstrate that the extent to which DC maturation and activation are altered by these factors correlates with melanoma tumorigenicity, and we identify partial roles for tumor-derived transforming growth factor (TGF)β1 and vascular endothelial growth factor (VEGF)-A in the altered functionality of DCs. In vivo studies using a lung metastasis model of melanoma also demonstrate tumorigenicity-dependent alterations to the function of lung-resident DCs, and skewed production of proinflammatory cytokines and chemokines by these tumor-altered cells is associated with recruitment of an immune infiltrate that may ultimately favor tumor immune escape and outgrowth. PMID:26010746

  16. Muscle sympathetic nerve activity and hemodynamic alterations in middle-aged obese women

    OpenAIRE

    Ribeiro M.M.; Trombetta I.C.; Batalha L.T.; Rondon M.U.P.B.; Forjaz C.L.M.; Barretto A.C.P.; Villares S.M.F.; Negrão C.E.

    2001-01-01

    To study the relationship between the sympathetic nerve activity and hemodynamic alterations in obesity, we simultaneously measured muscle sympathetic nerve activity (MSNA), blood pressure, and forearm blood flow (FBF) in obese and lean individuals. Fifteen normotensive obese women (BMI = 32.5 ± 0.5 kg/m²) and 11 age-matched normotensive lean women (BMI = 22.7 ± 1.0 kg/m²) were studied. MSNA was evaluated directly from the peroneal nerve by microneurography, FBF was measured by venous occlusi...

  17. HIV and Cocaine Impact Glial Metabolism: Energy Sensor AMP-activated protein kinase Role in Mitochondrial Biogenesis and Epigenetic Remodeling.

    Science.gov (United States)

    Samikkannu, Thangavel; Atluri, Venkata S R; Nair, Madhavan P N

    2016-01-01

    HIV infection and cocaine use have been identified as risk factors for triggering neuronal dysfunction. In the central nervous system (CNS), energy resource and metabolic function are regulated by astroglia. Glia is the major reservoir of HIV infection and disease progression in CNS. However, the role of cocaine in accelerating HIV associated energy deficit and its impact on neuronal dysfunction has not been elucidated yet. The aim of this study is to elucidate the molecular mechanism of HIV associated neuropathogenesis in cocaine abuse and how it accelerates the energy sensor AMPKs and its subsequent effect on mitochondrial oxidative phosphorylation (OXPHOS), BRSKs, CDC25B/C, MAP/Tau, Wee1 and epigenetics remodeling complex SWI/SNF. Results showed that cocaine exposure during HIV infection significantly increased the level of p24, reactive oxygen species (ROS), ATP-utilization and upregulated energy sensor AMPKs, CDC25B/C, MAP/Tau and Wee1 protein expression. Increased ROS production subsequently inhibits OCR/ECAR ratio and OXPHOS, and eventually upregulate epigenetics remodeling complex SWI/SNF in CHME-5 cells. These results suggest that HIV infection induced energy deficit and metabolic dysfunction is accelerated by cocaine inducing energy sensor AMPKs, mitochondrial biogenesis and chromatin remodeling complex SWI/SNF activation, which may lead to neuroAIDS disease progression. PMID:27535703

  18. Mitochondrial membrane potential in human neutrophils is maintained by complex III activity in the absence of supercomplex organisation.

    Directory of Open Access Journals (Sweden)

    Bram J van Raam

    Full Text Available BACKGROUND: Neutrophils depend mainly on glycolysis for their energy provision. Their mitochondria maintain a membrane potential (Deltapsi(m, which is usually generated by the respiratory chain complexes. We investigated the source of Deltapsi(m in neutrophils, as compared to peripheral blood mononuclear leukocytes and HL-60 cells, and whether neutrophils can still utilise this Deltapsi(m for the generation of ATP. METHODS AND PRINCIPAL FINDINGS: Individual activity of the oxidative phosphorylation complexes was significantly reduced in neutrophils, except for complex II and V, but Deltapsi(m was still decreased by inhibition of complex III, confirming the role of the respiratory chain in maintaining Deltapsi(m. Complex V did not maintain Deltapsi(m by consumption of ATP, as has previously been suggested for eosinophils. We show that complex III in neutrophil mitochondria can receive electrons from glycolysis via the glycerol-3-phosphate shuttle. Furthermore, respiratory supercomplexes, which contribute to efficient coupling of the respiratory chain to ATP synthesis, were lacking in neutrophil mitochondria. When HL-60 cells were differentiated to neutrophil-like cells, they lost mitochondrial supercomplex organisation while gaining increased aerobic glycolysis, just like neutrophils. CONCLUSIONS: We show that neutrophils can maintain Deltapsi(m via the glycerol-3-phosphate shuttle, whereby their mitochondria play an important role in the regulation of aerobic glycolysis, rather than producing energy themselves. This peculiar mitochondrial phenotype is acquired during differentiation from myeloid precursors.

  19. HIV and Cocaine Impact Glial Metabolism: Energy Sensor AMP-activated protein kinase Role in Mitochondrial Biogenesis and Epigenetic Remodeling

    Science.gov (United States)

    Samikkannu, Thangavel; Atluri, Venkata S. R.; Nair, Madhavan P. N.

    2016-01-01

    HIV infection and cocaine use have been identified as risk factors for triggering neuronal dysfunction. In the central nervous system (CNS), energy resource and metabolic function are regulated by astroglia. Glia is the major reservoir of HIV infection and disease progression in CNS. However, the role of cocaine in accelerating HIV associated energy deficit and its impact on neuronal dysfunction has not been elucidated yet. The aim of this study is to elucidate the molecular mechanism of HIV associated neuropathogenesis in cocaine abuse and how it accelerates the energy sensor AMPKs and its subsequent effect on mitochondrial oxidative phosphorylation (OXPHOS), BRSKs, CDC25B/C, MAP/Tau, Wee1 and epigenetics remodeling complex SWI/SNF. Results showed that cocaine exposure during HIV infection significantly increased the level of p24, reactive oxygen species (ROS), ATP-utilization and upregulated energy sensor AMPKs, CDC25B/C, MAP/Tau and Wee1 protein expression. Increased ROS production subsequently inhibits OCR/ECAR ratio and OXPHOS, and eventually upregulate epigenetics remodeling complex SWI/SNF in CHME-5 cells. These results suggest that HIV infection induced energy deficit and metabolic dysfunction is accelerated by cocaine inducing energy sensor AMPKs, mitochondrial biogenesis and chromatin remodeling complex SWI/SNF activation, which may lead to neuroAIDS disease progression. PMID:27535703

  20. Cadmium Activates Reactive Oxygen Species-dependent AKT/mTOR and Mitochondrial Apoptotic Pathways in Neuronal Cells

    Institute of Scientific and Technical Information of China (English)

    YUAN Yan; BIAN Jian Chun; LIU Zong Ping; WANG Yi; HU Fei Fei; JIANG Chen Yang; ZHANG Ya Jing; YANG Jin Long; ZHAO Shi Wen; GU Jian Hong; LIU Xue Zhong

    2016-01-01

    ObjectiveTo examine the role of Cd-induced reactive oxygen species (ROS) generation in the apoptosis of neuronal cells. MethodsNeuronal cells (primary rat cerebral cortical neurons and PC12cells) were incubated with or without Cd post-pretreatment with rapamycin (Rap) or N-acetyl-L-cysteine (NAC). Cell viability was determined by MTT assay, apoptosis was examined using flow cytometry and fluorescence microscopy, and the activation of phosphoinositide 3'-kinase/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) and mitochondrial apoptotic pathways were measured by western blotting or immunofluorescence assays. ResultsCd-induced activation of Akt/mTOR signaling, including Akt, mTOR,p70 S6 kinase (p70 S6K), and eukaryotic initiation factor 4E binding protein 1(4E-BP1). Rap, an mTOR inhibitor and NAC, a ROS scavenger, blocked Cd-induced activation of Akt/mTOR signaling and apoptosis of neuronal cells. Furthermore, NAC blocked the decrease of B-cell lymphoma 2/Bcl-2 associated X protein (Bcl-2/Bax) ratio, release of cytochrome c, cleavage of caspase-3 and poly(ADP-ribose) polymerase (PARP), and nuclear translocation of apoptosis-inducing factor(AIF)and endonuclease G (Endo G). ConclusionCd-induced ROS generation activates Akt/mTOR and mitochondrial pathways, leading to apoptosis ofneuronal cells. Our findings suggest that mTOR inhibitors or antioxidants have potential for preventing Cd-induced neurodegenerative diseases.

  1. Activation of SIRT3 attenuates triptolide-induced toxicity through closing mitochondrial permeability transition pore in cardiomyocytes.

    Science.gov (United States)

    Yang, Yanqin; Wang, Wenwen; Xiong, Zhewen; Kong, Jiamin; Qiu, Yuwen; Shen, Feihai; Huang, Zhiying

    2016-08-01

    Triptolide (TP), an active component of the traditional Chinese herb Tripterygium wilfordii Hook f. (TWHF), has multiple pharmacological effects. However, the severe toxicity of TP greatly restricts its clinical applications. Although TP exposure causes serious heart injury, the mechanism underlying TP-induced cardiotoxicity has rarely been investigated. In previous studies, we found that TP-induced oxidative stress was involved in the mitochondria-dependent apoptosis of cardiomyocytes. Opening of the mitochondrial permeability transition pore (mPTP) is the key to the mitochondrial dysfunction in cardiac toxicity. The aim of this study was to investigate the potential cardioprotective effects of sirtuin 3 (SIRT3) on the mPTP. In the present study, the cytotoxicity of TP was accompanied by the up-regulation of the SIRT3 protein level and its rapid aggregation in nuclei and mitochondria. The SIRT3-FOXO3 signaling pathway was activated simultaneously, resulting in increased transcription of manganese superoxide dismutase (MnSOD) and catalase (CAT) for the elimination of reactive oxygen species (ROS). In addition, augmentation of the SIRT3 level via the overexpression plasmid SIRT3-Flag provided resistance to TP-induced cellular damage, whereas knocking down the SIRT3 level via siRNA accelerated the damage. Because it is an activator of SIRT3, the protective effect of resveratrol was also evaluated in H9c2 cells. In conclusion, the current results suggest that activation of SIRT3 substantially ameliorates the detrimental effects of TP by closing the mPTP. PMID:27064125

  2. Mitochondrial dynamics and apoptosis

    OpenAIRE

    Suen, Der-Fen; Norris, Kristi L.; Youle, Richard J.

    2008-01-01

    In healthy cells, mitochondria continually divide and fuse to form a dynamic interconnecting network. The molecular machinery that mediates this organelle fission and fusion is necessary to maintain mitochondrial integrity, perhaps by facilitating DNA or protein quality control. This network disintegrates during apoptosis at the time of cytochrome c release and prior to caspase activation, yielding more numerous and smaller mitochondria. Recent work shows that proteins involved in mitochondri...

  3. The plant mitochondrial proteome

    DEFF Research Database (Denmark)

    Millar, A.H.; Heazlewood, J.L.; Kristensen, B.K.;

    2005-01-01

    The plant mitochondrial proteome might contain as many as 2000-3000 different gene products, each of which might undergo post-translational modification. Recent studies using analytical methods, such as one-, two- and three-dimensional gel electrophoresis and one- and two-dimensional liquid...... context to be defined for them. There are indications that some of these proteins add novel activities to mitochondrial protein complexes in plants....

  4. Repeated Episodes of Heroin Cause Enduring Alterations of Circadian Activity in Protracted Abstinence

    Directory of Open Access Journals (Sweden)

    Luis Stinus

    2012-09-01

    Full Text Available Opiate withdrawal is followed by a protracted abstinence syndrome consisting of craving and physiological changes. However, few studies have been dedicated to both the characterization and understanding of these long-term alterations in post-dependent subjects. The aim of the present study was to develop an opiate dependence model, which induces long-lasting behavioral changes in abstinent rats. Here, we first compared the effects of several protocols for the induction of opiate dependence (morphine pellets, repeated morphine or heroin injections on the subsequent response to heroin challenges (0.25 mg/kg at different time points during abstinence (3, 6, 9 and 18 weeks. In a second set of experiments, rats were exposed to increasing doses of heroin and subsequently monitored for general circadian activity up to 20 weeks of abstinence. Results show that heroin injections rather than the other methods of opiate administration have long-term consequences on rats’ sensitivity to heroin with its psychostimulant effects persisting up to 18 weeks of abstinence. Moreover, intermittent episodes of heroin dependence rather than a single exposure produce enduring alteration of the basal circadian activity both upon heroin cessation and protracted abstinence. Altogether, these findings suggest that the induction of heroin dependence through intermittent increasing heroin injections is the optimal method to model long-term behavioral alterations during protracted abstinence in rats. This animal model would be useful in further characterizing long-lasting changes in post-dependent subjects to help understand the prolonged vulnerability to relapse.

  5. Repeated episodes of heroin cause enduring alterations of circadian activity in protracted abstinence.

    Science.gov (United States)

    Stinus, Luis; Cador, Martine; Caille, Stephanie

    2012-01-01

    Opiate withdrawal is followed by a protracted abstinence syndrome consisting of craving and physiological changes. However, few studies have been dedicated to both the characterization and understanding of these long-term alterations in post-dependent subjects. The aim of the present study was to develop an opiate dependence model, which induces long-lasting behavioral changes in abstinent rats. Here, we first compared the effects of several protocols for the induction of opiate dependence (morphine pellets, repeated morphine or heroin injections) on the subsequent response to heroin challenges (0.25 mg/kg) at different time points during abstinence (3, 6, 9 and 18 weeks). In a second set of experiments, rats were exposed to increasing doses of heroin and subsequently monitored for general circadian activity up to 20 weeks of abstinence. Results show that heroin injections rather than the other methods of opiate administration have long-term consequences on rats' sensitivity to heroin with its psychostimulant effects persisting up to 18 weeks of abstinence. Moreover, intermittent episodes of heroin dependence rather than a single exposure produce enduring alteration of the basal circadian activity both upon heroin cessation and protracted abstinence. Altogether, these findings suggest that the induction of heroin dependence through intermittent increasing heroin injections is the optimal method to model long-term behavioral alterations during protracted abstinence in rats. This animal model would be useful in further characterizing long-lasting changes in post-dependent subjects to help understand the prolonged vulnerability to relapse. PMID:24961201

  6. A role for peroxisome proliferator-activated receptor γ coactivator 1 (PGC-1) in the regulation of cardiac mitochondrial phospholipid biosynthesis.

    Science.gov (United States)

    Lai, Ling; Wang, Miao; Martin, Ola J; Leone, Teresa C; Vega, Rick B; Han, Xianlin; Kelly, Daniel P

    2014-01-24

    The energy demands of the adult mammalian heart are met largely by ATP generated via oxidation of fatty acids in a high capacity mitochondrial system. Peroxisome proliferator-activated receptor γ coactivator 1 (PGC-1)-α and -β serve as inducible transcriptional coregulators of genes involved in mitochondrial biogenesis and metabolism. Whether PGC-1 plays a role in the regulation of mitochondrial structure is unknown. In this study, mice with combined deficiency of PGC-1α and PGC-1β (PGC-1αβ(-/-)) in adult heart were analyzed. PGC-1αβ(-/-) hearts exhibited a distinctive mitochondrial cristae-stacking abnormality suggestive of a phospholipid abnormality as has been described in humans with genetic defects in cardiolipin (CL) synthesis (Barth syndrome). A subset of molecular species, containing n-3 polyunsaturated species in the CL, phosphatidylcholine, and phosphatidylethanolamine profiles, was reduced in PGC-1αβ-deficient hearts. Gene expression profiling of PGC-1αβ(-/-) hearts revealed reduced expression of the gene encoding CDP-diacylglycerol synthase 1 (Cds1), an enzyme that catalyzes the proximal step in CL biosynthesis. Cds1 gene promoter-reporter cotransfection experiments and chromatin immunoprecipitation studies demonstrated that PGC-1α coregulates estrogen-related receptors to activate the transcription of the Cds1 gene. We conclude that the PGC-1/estrogen-related receptor axis coordinately regulates metabolic and membrane structural programs relevant to the maintenance of high capacity mitochondrial function in heart. PMID:24337569

  7. Complete denture base assessments using holograms: dimensional alterations after different activation methods

    Science.gov (United States)

    Dughir, Ciprian; Popovschi, Ana Maria; Cojocariu, Andreea Codruta; Topala, Florin Ionel; Negrutiu, Meda Lavinia; Sinescu, Cosmin; de Sabata, Aldo; Duma, Virgil-Florin

    2016-03-01

    Holography is a well-developed method with a large range of applications, including dentistry. This study uses holographic methods for the study of total dental prosthesis. The issue is that the transformation of wax denture base in polymethylacrylate causes dimensional alterations and retractions in the final dental constructs. These could cause the failure of the stability of the complete denture in the oral cavity. Thus, the aim of this study is to determine and to compare using holography, total prosthesis obtained using three different manufacturing methods: pressing, injection, and polymerization. Each of the three types of dentures thus produced were recorded over the previously wax complete base holographic plates. The dimensional alterations that appear after using the different activation methods were thus determined. The most significant modification was remarked in the custom press technology, while the smallest variations were detected in the injection alternative.

  8. Coupled aggregation of mitochondrial single-strand DNA-binding protein tagged with Eos fluorescent protein visualizes synchronized activity of mitochondrial nucleoids

    Czech Academy of Sciences Publication Activity Database

    Olejár, Tomáš; Pajuelo-Reguera, David; Alán, Lukáš; Dlasková, Andrea; Ježek, Petr

    2015-01-01

    Roč. 12, č. 4 (2015), s. 5185-5190. ISSN 1791-2997 R&D Projects: GA ČR(CZ) GAP302/10/0346; GA MŠk(CZ) EE2.3.30.0025 Institutional support: RVO:67985823 Keywords : mitochondrial nucleoid * single-stranded DNA-binding protein * photoconvertible fluorescent protein Eos Subject RIV: EA - Cell Biology Impact factor: 1.554, year: 2014

  9. Alteration of membrane phospholipid methylation by adenosine analogs does not affect T lymphocyte activation

    International Nuclear Information System (INIS)

    Membrane phospholipid methylation has been described during activation of various immune cells. Moreover recent data indicated modulation of immune cells functions by adenosine. As S-adenosyl-methionine and S-adenosyl-homocysteine are adenosine analogs and modulators of transmethylation reactions, the effects of SAH and SAM were investigated on membrane phospholipid methylation and lymphocyte activation. SAM was shown to induce the membrane phospholipid methylation as assessed by the 3Hmethyl-incorporation in membrane extract. This effect was inhibited by SAH. In contrast SAM and SAH did not affect the phytohemagglutinin-induced proliferative response of peripheral blood mononuclear cells. SAH neither modified the early internalization of membrane CD3 antigens nor did it prevent the late expression of HLA-DR antigens on lymphocytes activated by phytohemagglutinin. These results indicate that in vitro alteration of phospholipid methylation does not affect subsequent steps of human T lymphocyte activation and proliferation

  10. Cdk5-mediated mitochondrial fission: A key player in dopaminergic toxicity in Huntington's disease.

    Science.gov (United States)

    Cherubini, Marta; Puigdellívol, Mar; Alberch, Jordi; Ginés, Silvia

    2015-10-01

    The molecular mechanisms underlying striatal vulnerability in Huntington's disease (HD) are still unknown. However, growing evidence suggest that mitochondrial dysfunction could play a major role. In searching for a potential link between striatal neurodegeneration and mitochondrial defects we focused on cyclin-dependent kinase 5 (Cdk5). Here, we demonstrate that increased mitochondrial fission in mutant huntingtin striatal cells can be a consequence of Cdk5-mediated alterations in Drp1 subcellular distribution and activity since pharmacological or genetic inhibition of Cdk5 normalizes Drp1 function ameliorating mitochondrial fragmentation. Interestingly, mitochondrial defects in mutant huntingtin striatal cells can be worsened by D1 receptor activation a process also mediated by Cdk5 as down-regulation of Cdk5 activity abrogates the increase in mitochondrial fission, the translocation of Drp1 to the mitochondria and the raise of Drp1 activity induced by dopaminergic stimulation. In sum, we have demonstrated a new role for Cdk5 in HD pathology by mediating dopaminergic neurotoxicity through modulation of Drp1-induced mitochondrial fragmentation, which underscores the relevance for pharmacologic interference of Cdk5 signaling to prevent or ameliorate striatal neurodegeneration in HD. PMID:26143143

  11. SIRT1 activation by pterostilbene attenuates the skeletal muscle oxidative stress injury and mitochondrial dysfunction induced by ischemia reperfusion injury.

    Science.gov (United States)

    Cheng, Yedong; Di, Shouyin; Fan, Chongxi; Cai, Liping; Gao, Chao; Jiang, Peng; Hu, Wei; Ma, Zhiqiang; Jiang, Shuai; Dong, Yushu; Li, Tian; Wu, Guiling; Lv, Jianjun; Yang, Yang

    2016-08-01

    Ischemia reperfusion (IR) injury is harmful to skeletal muscles and causes mitochondrial oxidative stress. Pterostilbene (PTE), an analogue of resveratrol, has organic protective effects against oxidative stress. However, no studies have investigated whether PTE can protect against IR-related skeletal muscular injury. In this study, we sought to evaluate the protective effect of PTE against IR-related skeletal muscle injury and to determine the mechanisms in this process. Male Sprague-Dawley rats were pretreated with PTE for a week and then underwent limb IR surgery. The IR injury induced segmental necrosis and apoptosis, myofilament disintegration, thicker interstitial spaces, and inflammatory cell infiltration. Furthermore, mitochondrial respiratory chain activity in the muscular tissue was inhibited, methane dicarboxylic aldehyde concentration and myeloperoxidase activity were up-regulated, and superoxide dismutase was down-regulated after IR. However, these effects were significantly inhibited by PTE in a dose-dependent manner. The mechanism underlying IR injury is attributed to the down-regulation of silent information regulator 1 (SIRT1)-FOXO1/p53 pathway and the increase of the Bax/Bcl2 ratio, Cleaved poly ADP-ribose polymerase 1, Cleaved Caspase 3, which can be reversed with PTE. Furthermore, EX527, an SIRT1 inhibitor, counteracted the protective effects of PTE on IR-related muscle injury. In conclusion, PTE has protective properties against IR injury of the skeletal muscles. The mechanism of this protective effect depends on the activation of the SIRT1-FOXO1/p53 signaling pathway and the decrease of the apoptotic ratio in skeletal muscle cells. PMID:27270300

  12. Altered expression of genes involved in mitochondrial oxidative phosphorylation and insulin signaling in skeletal muscle of obese women with polycystic ovary syndrome (PCOS)

    DEFF Research Database (Denmark)

    Skov, Vibe

    similar importance for insulin resistance in the polycystic ovary syndrome (PCOS).   Materials and methods: Using the HG-U133 Plus 2.0 expression array from Affymetrix, we analyzed gene expression in skeletal muscle from obese women with PCOS (n=16) and age- and body mass index-matched control women (n=13...... sum statistic and conducting a permutation test. Subsequently, we performed biological pathway analysis using Gene Set Enrichment Analysis (GSEA) and Gene Microarray Pathway Profiler (GenMAPP).   Results: Women with PCOS were characterized by fasting hyperinsulinemia and impaired insulin...... validated by quantitative real-time PCR and immunoblot analyses.   Conclusion: Our results, for the first time, provide evidence for an association between insulin resistance and impaired mitochondrial oxidative metabolism in skeletal muscle in women with PCOS. Furthermore, differential expression of genes...

  13. Altered cognition-related brain activity and interactions with acute pain in migraine

    Directory of Open Access Journals (Sweden)

    Vani A. Mathur

    2015-01-01

    Full Text Available Little is known about the effect of migraine on neural cognitive networks. However, cognitive dysfunction is increasingly being recognized as a comorbidity of chronic pain. Pain appears to affect cognitive ability and the function of cognitive networks over time, and decrements in cognitive function can exacerbate affective and sensory components of pain. We investigated differences in cognitive processing and pain–cognition interactions between 14 migraine patients and 14 matched healthy controls using an fMRI block-design with two levels of task difficulty and concurrent heat (painful and not painful stimuli. Across groups, cognitive networks were recruited in response to a difficult cognitive task, and a pain–task interaction was found in the right (contralateral to pain stimulus posterior insula (pINS, such that activity was modulated by decreasing the thermal pain stimulus or by engaging the difficult cognitive task. Migraine patients had less task-related deactivation within the left dorsolateral prefrontal cortex (DLPFC and left dorsal anterior midcingulate cortex (aMCC compared to controls. These regions have been reported to have decreased cortical thickness and cognitive-related deactivation within other pain populations, and are also associated with pain regulation, suggesting that the current findings may reflect altered cognitive function and top-down regulation of pain. During pain conditions, patients had decreased task-related activity, but more widespread task-related reductions in pain-related activity, compared to controls, suggesting cognitive resources may be diverted from task-related to pain-reduction-related processes in migraine. Overall, these findings suggest that migraine is associated with altered cognitive-related neural activity, which may reflect altered pain regulatory processes as well as broader functional restructuring.

  14. Altered muscular activation during prone hip extension in women with and without low back pain

    Directory of Open Access Journals (Sweden)

    Arab Amir M

    2011-08-01

    Full Text Available Abstract Background Altered movement pattern has been associated with the development of low back pain (LBP. The purpose of this study was to investigate the activity pattern of the ipsilateral erector spinae (IES and contralateral erectorspinae (CES, gluteus maximus (GM and hamstring (HAM muscles during prone hip extension (PHE test in women with and without LBP. A cross-sectional non-experimental design was used. Methods Convenience sample of 20 female participated in the study. Subjects were categorized into two groups: with LBP (n = 10 and without LBP (n = 10. The electromyography (EMG signal amplitude of the tested muscles during PHE (normalized to maximum voluntary electrical activity (MVE was measured in the dominant lower extremity in all subjects. Results Statistical analysis revealed greater normalized EMG signal amplitude in women with LBP compared to non-LBP women. There was significant difference in EMG activity of the IES (P = 0.03 and CES (P = 0.03 between two groups. However, no significant difference was found in EMG signals of the GM (P = 0.11 and HAM (P = 0.14 among two groups. Conclusion The findings of this study demonstrated altered activation pattern of the lumbo-pelvic muscles during PHE in the women with chronic LBP. This information is important for investigators using PHE as either an evaluation tool or a rehabilitation exercise.

  15. Mediator-assisted Simultaneous probing of Cytosolic and Mitochondrial Redox activity in living cells

    DEFF Research Database (Denmark)

    Heiskanen, Arto; Spegel, Christer; Kostesha, Natalie;

    2009-01-01

    ferricyanide-menadione double mediator system to study the effect of dicoumarol, an inhibitor of cytosolic and mitochondrial oxidoreductases and an uncoupler of the electron transport chain. Evaluation of the role of NAD(P)H-producing pathways in mediating biological effects is facilitated by introducing...... either fructose or glucose as the carbon source, yielding either NADH or NADPH through the glycolytic or pen-rose phosphate pathway, respectively. Respiratory noncompetent cells show greater inhibition of cytosolic menadione-reducing enzymes when NADH rather than NADPH is produced. Spectrophotometric in...... vitro assays show no difference between the cofactors. Respiratory competent cells show cytosolic inhibition only when NADPH is produced, whereas production of NADH reveals uncoupling at low dicoumarol concentrations and inhibition of complexes III and IV at higher concentrations. Spectrophotometric...

  16. S-nitrosylation of the Mitochondrial Chaperone TRAP1 Sensitizes Hepatocellular Carcinoma Cells to Inhibitors of Succinate Dehydrogenase

    DEFF Research Database (Denmark)

    Rizza, Salvatore; Montagna, Costanza; Cardaci, Simone;

    2016-01-01

    . We find that hepatocyte GSNOR deficiency is characterized by mitochondrial alteration and by marked increases in succinate dehydrogenase (SDH) levels and activity. We find that this depends on the selective S-nitrosylation of Cys(501) in the mitochondrial chaperone TRAP1, which mediates its......-nitrosylation in HCC, a novel molecular target in SDH, and a first-in-class therapy to treat the disease. Cancer Res; 76(14); 1-13. ©2016 AACR....

  17. Intrinsic Brain Activity in Altered States of Consciousness: How Conscious Is the Default Mode of Brain Function?

    OpenAIRE

    Boly, M; Phillips, C.; Tshibanda, L; Vanhaudenhuyse, A.; Schabus, M.; Dang-Vu, T.T.; Moonen, G.; Hustinx, R.; Maquet, P; Laureys, S.

    2008-01-01

    Spontaneous brain activity has recently received increasing interest in the neuroimaging community. However, the value of resting-state studies to a better understanding of brain–behavior relationships has been challenged. That altered states of consciousness are a privileged way to study the relationships between spontaneous brain activity and behavior is proposed, and common resting-state brain activity features observed in various states of altered consciousness are reviewed. Early positro...

  18. Distribution and location of selenium and other elements in different mitochondrial compartments of human liver by neutron activation analysis

    International Nuclear Information System (INIS)

    Mitochondria are important organelles involved in energy production, carbohydrate metabolism, heme biosynthesis and the urea cycle. In the present study the distribution patterns of eleven elements in mitochondrial compartments of normal human liver specimens were studied by applying the chemical separation techniques and differential centrifugation combined with element-specific methods of instrumental neutron activation analysis (INAA) and hydrid-generation atomic fluorescence spectrometry (HG-AFS). The results showed that the concentrations were higher of Ca, Co and Zn in the matrix and Ba, Cr, Fe, Sb, Sc, and Th in the outer membrane, whereas the highest concentration of Rb was in the intermembrane space. Interestingly, the lowest concentrations of all the eleven elements, except Se, were found in the inner membrane. (author)

  19. Mutations in the catalytic loop HRD motif alter the activity and function of Drosophila Src64.

    Directory of Open Access Journals (Sweden)

    Taylor C Strong

    Full Text Available The catalytic loop HRD motif is found in most protein kinases and these amino acids are predicted to perform functions in catalysis, transition to, and stabilization of the active conformation of the kinase domain. We have identified mutations in a Drosophila src gene, src64, that alter the three HRD amino acids. We have analyzed the mutants for both biochemical activity and biological function during development. Mutation of the aspartate to asparagine eliminates biological function in cytoskeletal processes and severely reduces fertility, supporting the amino acid's critical role in enzymatic activity. The arginine to cysteine mutation has little to no effect on kinase activity or cytoskeletal reorganization, suggesting that the HRD arginine may not be critical for coordinating phosphotyrosine in the active conformation. The histidine to leucine mutant retains some kinase activity and biological function, suggesting that this amino acid may have a biochemical function in the active kinase that is independent of its side chain hydrogen bonding interactions in the active site. We also describe the phenotypic effects of other mutations in the SH2 and tyrosine kinase domains of src64, and we compare them to the phenotypic effects of the src64 null allele.

  20. Subneurotoxic copper(II)-induced NF-κB-dependent microglial activation is associated with mitochondrial ROS

    International Nuclear Information System (INIS)

    Microglia-mediated neuroinflammation and the associated neuronal damage play critical roles in the pathogenesis of neurodegenerative disorders. Evidence shows an elevated concentration of extracellular copper(II) in the brains of these disorders, which may contribute to neuronal death through direct neurotoxicity. Here we explored whether extracellular copper(II) triggers microglial activation. Primary rat microglia and murine microglial cell line BV-2 cells were cultured and treated with copper(II). The content of tumor necrosis factor-α (TNF-α) and nitric oxide in the medium was determined. Extracellular hydrogen peroxide was quantified by a fluorometric assay with Amplex Red. Mitochondrial superoxide was measured by MitoSOX oxidation. At subneurotoxic concentrations, copper(II) treatment induced a dose- and time-dependent release of TNF-α and nitric oxide from microglial cells, and caused an indirect, microglia-mediated neurotoxicity that was blocked by inhibition of TNF-α and nitric oxide production. Copper(II)-initiated microglial activation was accompanied with reduced IkB-α expression as well as phosphorylation and translocation of nuclear factor-κB (NF-κB) p65 and was blocked by NF-κB inhibitors (BAY11-7082 and SC-514). Moreover, copper(II) treatment evoked a rapid release of hydrogen peroxide from microglial cells, an effect that was not affected by NADPH oxidase inhibitors. N-acetyl-cysteine, a scavenger of reactive oxygen species (ROS), abrogated copper(II)-elicited microglial release of TNF-α and nitric oxide and subsequent neurotoxicity. Importantly, mitochondrial production of superoxide, paralleled to extracellular release of hydrogen peroxide, was induced after copper(II) stimulation. Our findings suggest that extracellular copper(II) at subneurotoxic concentrations could trigger NF-κB-dependent microglial activation and subsequent neurotoxicity. NADPH oxidase-independent, mitochondria-derived ROS may be involved in this activation

  1. Subneurotoxic copper(II)-induced NF-κB-dependent microglial activation is associated with mitochondrial ROS

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Zhuqin; Yu, Fengxiang; Gong, Ping; Qiu, Yu; Zhou, Wei; Cui, Yongyao; Li, Juan, E-mail: lijuanpharm@gmail.com; Chen, Hongzhuan, E-mail: yaoli@shsmu.edu.cn

    2014-04-15

    Microglia-mediated neuroinflammation and the associated neuronal damage play critical roles in the pathogenesis of neurodegenerative disorders. Evidence shows an elevated concentration of extracellular copper(II) in the brains of these disorders, which may contribute to neuronal death through direct neurotoxicity. Here we explored whether extracellular copper(II) triggers microglial activation. Primary rat microglia and murine microglial cell line BV-2 cells were cultured and treated with copper(II). The content of tumor necrosis factor-α (TNF-α) and nitric oxide in the medium was determined. Extracellular hydrogen peroxide was quantified by a fluorometric assay with Amplex Red. Mitochondrial superoxide was measured by MitoSOX oxidation. At subneurotoxic concentrations, copper(II) treatment induced a dose- and time-dependent release of TNF-α and nitric oxide from microglial cells, and caused an indirect, microglia-mediated neurotoxicity that was blocked by inhibition of TNF-α and nitric oxide production. Copper(II)-initiated microglial activation was accompanied with reduced IkB-α expression as well as phosphorylation and translocation of nuclear factor-κB (NF-κB) p65 and was blocked by NF-κB inhibitors (BAY11-7082 and SC-514). Moreover, copper(II) treatment evoked a rapid release of hydrogen peroxide from microglial cells, an effect that was not affected by NADPH oxidase inhibitors. N-acetyl-cysteine, a scavenger of reactive oxygen species (ROS), abrogated copper(II)-elicited microglial release of TNF-α and nitric oxide and subsequent neurotoxicity. Importantly, mitochondrial production of superoxide, paralleled to extracellular release of hydrogen peroxide, was induced after copper(II) stimulation. Our findings suggest that extracellular copper(II) at subneurotoxic concentrations could trigger NF-κB-dependent microglial activation and subsequent neurotoxicity. NADPH oxidase-independent, mitochondria-derived ROS may be involved in this activation

  2. REGULATION OF THE EXPRESSION OF MITOCHONDRIAL PROTEINS - RELATIONSHIP BETWEEN MTDNA COPY NUMBER AND CYTOCHROME-C-OXIDASE ACTIVITY IN HUMAN-CELLS AND TISSUES

    NARCIS (Netherlands)

    VANDENBOGERT, C; DEVRIES, H; HOLTROP, M; MUUS, P; DEKKER, HL; VANGALEN, MJM; BOLHUIS, PA; TAANMAN, JW

    1993-01-01

    The relationship between the relative amounts of nuclear and mitochondrial genes for cytochrome-c oxidase subunits and their transcripts and cytochrome-c oxidase activity was investigated in several human tissues and cell lines to get more insight into the regulation of the expression of this mitoch

  3. Pressure overload-induced mild cardiac hypertrophy reduces left ventricular transmural differences in mitochondrial respiratory chain activity and increases oxidative stress

    OpenAIRE

    BernardGENY; MichelKINDO; LaurentMONASSIER; FabriceFAVRET

    2012-01-01

    Objective: Increased mechanical stress and contractility characterizes normal left ventricular subendocardium (Endo) but whether Endo mitochondrial respiratory chain complex activities is reduced as compared to subepicardium (Epi) and whether pressure overload-induced left ventricular hypertrophy (LVH) might modulate transmural gradients through increased reactive oxygen species (ROS) production is unknown. Methods: LVH was induced by 6 weeks abdominal aortic banding and cardiac structure...

  4. Activity based protein profiling to detect serine hydrolase alterations in virus infected cells

    Directory of Open Access Journals (Sweden)

    MdShahiduzzaman

    2012-08-01

    Full Text Available Activity based protein profiling (ABPP is a newly emerging technique that uses active site-directed probes to monitor the functional status of enzymes. Serine hydrolases are one of the largest families of enzymes in mammals. More than 200 serine hydrolases have been identified but little is known about their specific roles. Serine hydrolases are involved in a variety of physiological functions, including digestion, immune response, blood coagulation and reproduction. ABPP has been used recently to investigate host-virus interactions and to understand the molecular pathogenesis of virus infections. Monitoring the altered serine hydrolases during viral infection gives insight into the catalytic activity of these enzymes that will help to identify novel targets for diagnostic and therapeutic application. This review presents the usefulness of ABPP in detecting and analyzing functional annotation of host cell serine hydrolases as a result of host-virus interaction.

  5. SGIP1 alters internalization and modulates signaling of activated cannabinoid receptor 1 in a biased manner.

    Science.gov (United States)

    Hájková, Alena; Techlovská, Šárka; Dvořáková, Michaela; Chambers, Jayne Nicole; Kumpošt, Jiří; Hubálková, Pavla; Prezeau, Laurent; Blahos, Jaroslav

    2016-08-01

    Many diseases of the nervous system are accompanied by alterations in synaptic functions. Synaptic plasticity mediated by the endogenous cannabinoid system involves the activation of the cannabinoid receptor 1 (CB1R). The principles of CB1R signaling must be understood in detail for its therapeutic exploration. We detected the Src homology 3-domain growth factor receptor-bound 2-like (endophilin) interacting protein 1 (SGIP1) as a novel CB1R partner. SGIP1 is functionally linked to clathrin-mediated endocytosis and its overexpression in animals leads to an energy regulation imbalance resulting in obesity. We report that SGIP1 prevents the endocytosis of activated CB1R and that it alters signaling via the CB1R in a biased manner. CB1R mediated G-protein activation is selectively influenced by SGIP1, β-arrestin associated signaling is changed profoundly, most likely as a consequence of the prevention of the receptor's internalization elicited by SGIP1. PMID:26970018

  6. Muscle sympathetic nerve activity and hemodynamic alterations in middle-aged obese women

    Directory of Open Access Journals (Sweden)

    Ribeiro M.M.

    2001-01-01

    Full Text Available To study the relationship between the sympathetic nerve activity and hemodynamic alterations in obesity, we simultaneously measured muscle sympathetic nerve activity (MSNA, blood pressure, and forearm blood flow (FBF in obese and lean individuals. Fifteen normotensive obese women (BMI = 32.5 ± 0.5 kg/m² and 11 age-matched normotensive lean women (BMI = 22.7 ± 1.0 kg/m² were studied. MSNA was evaluated directly from the peroneal nerve by microneurography, FBF was measured by venous occlusion plethysmography, and blood pressure was measured noninvasively by an autonomic blood pressure cuff. MSNA was significantly increased in obese women when compared with lean control women. Forearm vascular resistance and blood pressure were significantly higher in obese women than in lean women. FBF was significantly lower in obese women. BMI was directly and significantly correlated with MSNA, blood pressure, and forearm vascular resistance levels, but inversely and significantly correlated with FBF levels. Obesity increases sympathetic nerve activity and muscle vascular resistance, and reduces muscle blood flow. These alterations, taken together, may explain the higher blood pressure levels in obese women when compared with lean age-matched women.

  7. Altered gene expression in highly purified enterocytes from patients with active coeliac disease

    Directory of Open Access Journals (Sweden)

    Jackson John

    2008-08-01

    Full Text Available Abstract Background Coeliac disease is a multifactorial inflammatory disorder of the intestine caused by ingestion of gluten in genetically susceptible individuals. Genes within the HLA-DQ locus are considered to contribute some 40% of the genetic influence on this disease. However, information on other disease causing genes is sparse. Since enterocytes are considered to play a central role in coeliac pathology, the aim of this study was to examine gene expression in a highly purified isolate of these cells taken from patients with active disease. Epithelial cells were isolated from duodenal biopsies taken from five coeliac patients with active disease and five non-coeliac control subjects. Contaminating T cells were removed by magnetic sorting. The gene expression profile of the cells was examined using microarray analysis. Validation of significantly altered genes was performed by real-time RT-PCR and immunohistochemistry. Results Enterocyte suspensions of high purity (98–99% were isolated from intestinal biopsies. Of the 3,800 genes investigated, 102 genes were found to have significantly altered expression between coeliac disease patients and controls (p Conclusion This study provides a profile of the molecular changes that occur in the intestinal epithelium of coeliac patients with active disease. Novel candidate genes were revealed which highlight the contribution of the epithelial cell to the pathogenesis of coeliac disease.

  8. Mitochondrial Myopathy

    Science.gov (United States)

    ... NINDS supports research focused on effective treatments and cures for mitochondrial myopathies and other mitochondrial diseases. Scientists are investigating the possible benefits of exercise programs and nutritional supplements, primarily natural and synthetic versions of CoQ10. While CoQ10 has ...

  9. Interventional effect of phycocyanin on mitochondrial membrane potential and activity of PC12 cells after hypoxia/reoxygenation

    Institute of Scientific and Technical Information of China (English)

    Nan Jiang; Yunliang Guo; Hongbing Chen

    2006-01-01

    BACKGROUND: Phycocyanin can relieve decrease of mitochondrial membrane potential through reducing production of active oxygen so as to protect neurons after hypoxia/reoxygenation.OBJECTIVE: To observe the effect of phycocyanin on activity of PC12 cells and mitochondrial membrane potential after hypoxia/reoxygenation.DESIGN: Randomized controlled study.SETTING: Cerebrovascular Disease Institute of Affiliated Hospital, Medical College of Qingdao University.MATERIALS: The experiment was carried out at the Key Laboratory of Prevention and Cure for cerebropathia in Shandong Province from October to December 2005. PC12 cells, rat chromaffin tumor cells,were provided by Storage Center of Wuhan University; phycocyanin was provided by Ocean Institute of Academia Sinica; Thiazoyl blue tetrazolium bromide (MTT) and rhodamine 123 were purchased from Sigma Company, USA; RPMI-1640 medium, fetal bovine serum and equine serum were purchased from Gibco Company, USA.METHODS: ① Culture of PC12 cells: PC12 cells were put into RPMI-1640 medium which contained 100 g/L heat inactivation equine serum and 0.05 volume fraction of fetal bovine serum and incubated in CO2 incubator at 37 ℃. Number of cells was regulated to 4 × 105 L-1, and cells were inoculated at 96-well culture plate.The final volume was 100 μL. ② Model establishing and grouping: Cultured PC12 cells were randomly divided into three groups: phycocyanin group, model control group and non-hypoxia group. At 24 hours before hypoxia, culture solution in phycocyanin group was added with phycocyanin so as to make sure the final concentration of 3 g/L, but cells in model control group did not add with phycocyanin. Cells in non-hypoxia group were also randomly divided into adding phycocyanin group (the final concentration of 3 g/L) and non-adding phycocyanin group. Cells in model control group and phycocyanin group were cultured with hypoxia for 1 hour and reoxygenation for 1, 2 and 3 hours; meanwhile, cells in non

  10. Anabolic steroids alter the physiological activity of aggression circuits in the lateral anterior hypothalamus.

    Science.gov (United States)

    Morrison, T R; Sikes, R W; Melloni, R H

    2016-02-19

    Syrian hamsters exposed to anabolic/androgenic steroids (AAS) during adolescence consistently show increased aggressive behavior across studies. Although the behavioral and anatomical profiles of AAS-induced alterations have been well characterized, there is a lack of data describing physiological changes that accompany these alterations. For instance, behavioral pharmacology and neuroanatomical studies show that AAS-induced changes in the vasopressin (AVP) neural system within the latero-anterior hypothalamus (LAH) interact with the serotonin (5HT) and dopamine (DA) systems to modulate aggression. To characterize the electrophysiological profile of the AAS aggression circuit, we recorded LAH neurons in adolescent male hamsters in vivo and microiontophoretically applied agonists and antagonists of aggressive behavior. The interspike interval (ISI) of neurons from AAS-treated animals correlated positively with aggressive behaviors, and adolescent AAS exposure altered parameters of activity in regular firing neurons while also changing the proportion of neuron types (i.e., bursting, regular, irregular). AAS-treated animals had more responsive neurons that were excited by AVP application, while cells from control animals showed the opposite effect and were predominantly inhibited by AVP. Both DA D2 antagonists and 5HT increased the firing frequency of AVP-responsive cells from AAS animals and dual application of AVP and D2 antagonists doubled the excitatory effect of AVP or D2 antagonist administration alone. These data suggest that multiple DA circuits in the LAH modulate AAS-induced aggressive responding. More broadly, these data show that multiple neurochemical interactions at the neurophysiological level are altered by adolescent AAS exposure. PMID:26691962

  11. The crowded sea: incorporating multiple marine activities in conservation plans can significantly alter spatial priorities.

    Directory of Open Access Journals (Sweden)

    Tessa Mazor

    Full Text Available Successful implementation of marine conservation plans is largely inhibited by inadequate consideration of the broader social and economic context within which conservation operates. Marine waters and their biodiversity are shared by a host of stakeholders, such as commercial fishers, recreational users and offshore developers. Hence, to improve implementation success of conservation plans, we must incorporate other marine activities while explicitly examining trade-offs that may be required. In this study, we test how the inclusion of multiple marine activities can shape conservation plans. We used the entire Mediterranean territorial waters of Israel as a case study to compare four planning scenarios with increasing levels of complexity, where additional zones, threats and activities were added (e.g., commercial fisheries, hydrocarbon exploration interests, aquaculture, and shipping lanes. We applied the marine zoning decision support tool Marxan to each planning scenario and tested a the ability of each scenario to reach biodiversity targets, b the change in opportunity cost and c the alteration of spatial conservation priorities. We found that by including increasing numbers of marine activities and zones in the planning process, greater compromises are required to reach conservation objectives. Complex plans with more activities incurred greater opportunity cost and did not reach biodiversity targets as easily as simplified plans with less marine activities. We discovered that including hydrocarbon data in the planning process significantly alters spatial priorities. For the territorial waters of Israel we found that in order to protect at least 10% of the range of 166 marine biodiversity features there would be a loss of ∼15% of annual commercial fishery revenue and ∼5% of prospective hydrocarbon revenue. This case study follows an illustrated framework for adopting a transparent systematic process to balance biodiversity goals and

  12. Autism and Intellectual Disability Associated with Mitochondrial Disease and Hyperlactacidemia

    OpenAIRE

    José Guevara-Campos; Lucía González-Guevara; Omar Cauli

    2015-01-01

    Autism spectrum disorder (ASD) with intellectual disability (ID) is a life-long debilitating condition, which is characterized by cognitive function impairment and other neurological signs. Children with ASD-ID typically attain motor skills with a significant delay. A sub-group of ASD-IDs has been linked to hyperlactacidemia and alterations in mitochondrial respiratory chain activity. The objective of this report is to describe the clinical features of patients with these comorbidities in ord...

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

    Science.gov (United States)

    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. PMID:25698500

  14. Bax/Bak-dependent, Drp1-independent Targeting of X-linked Inhibitor of Apoptosis Protein (XIAP) into Inner Mitochondrial Compartments Counteracts Smac/DIABLO-dependent Effector Caspase Activation.

    Science.gov (United States)

    Hamacher-Brady, Anne; Brady, Nathan Ryan

    2015-09-01

    Efficient apoptosis requires Bax/Bak-mediated mitochondrial outer membrane permeabilization (MOMP), which releases death-promoting proteins cytochrome c and Smac to the cytosol, which activate apoptosis and inhibit X-linked inhibitor of apoptosis protein (XIAP) suppression of executioner caspases, respectively. We recently identified that in response to Bcl-2 homology domain 3 (BH3)-only proteins and mitochondrial depolarization, XIAP can permeabilize and enter mitochondria. Consequently, XIAP E3 ligase activity recruits endolysosomes into mitochondria, resulting in Smac degradation. Here, we explored mitochondrial XIAP action within the intrinsic apoptosis signaling pathway. Mechanistically, we demonstrate that mitochondrial XIAP entry requires Bax or Bak and is antagonized by pro-survival Bcl-2 proteins. Moreover, intramitochondrial Smac degradation by XIAP occurs independently of Drp1-regulated cytochrome c release. Importantly, mitochondrial XIAP actions are activated cell-intrinsically by typical apoptosis inducers TNF and staurosporine, and XIAP overexpression reduces the lag time between the administration of an apoptotic stimuli and the onset of mitochondrial permeabilization. To elucidate the role of mitochondrial XIAP action during apoptosis, we integrated our findings within a mathematical model of intrinsic apoptosis signaling. Simulations suggest that moderate increases of XIAP, combined with mitochondrial XIAP preconditioning, would reduce MOMP signaling. To test this scenario, we pre-activated XIAP at mitochondria via mitochondrial depolarization or by artificially targeting XIAP to the intermembrane space. Both approaches resulted in suppression of TNF-mediated caspase activation. Taken together, we propose that XIAP enters mitochondria through a novel mode of mitochondrial permeabilization and through Smac degradation can compete with canonical MOMP to act as an anti-apoptotic tuning mechanism, reducing the mitochondrial contribution to the

  15. A krill oil supplemented diet reduces the activities of the mitochondrial tricarboxylate carrier and of the cytosolic lipogenic enzymes in rats.

    Science.gov (United States)

    Ferramosca, A; Conte, L; Zara, V

    2012-04-01

    The mitochondrial tricarboxylate carrier supplies cytosol with the carbon units necessary for hepatic lipogenesis. The activities of cytosolic acetyl-CoA carboxylase and fatty acid synthetase are therefore strictly connected to the function of mitochondrial tricarboxylate carrier. Dietary polyunsaturated fatty acids (PUFA) are potent modulators of hepatic lipogenesis. In rats fed with a diet enriched with 2.5% krill oil (KO), a novel source of dietary n-3 PUFA, a time-dependent decrease in the activities of the mitochondrial tricarboxylate carrier and of the lipogenic enzymes was found. The KO induced inhibition of hepatic lipogenesis was more pronounced than that found in fish oil (FO)-fed rats, at least at short feeding times. The decrease in the activity of the mitochondrial tricarboxylate carrier caused by KO was due to a reduced expression of the protein. Furthermore, in the KO-fed animals a greater reduction in the levels of hepatic triglycerides and cholesterol was found in comparison to FO-fed rats. PMID:21429045

  16. FXR activation induces mitochondrial mediated apoptosis in breast cancer and synergizes with tamoxifen.

    OpenAIRE

    Mohan, Rati

    2016-01-01

    Breast Cancer is one of the major causes of mortality among women in the world. During normal tissue development, cell growth is controlled by a mechanism of cell death called apoptosis. However, during cancer, the balance between cell division & apoptosis is altered, leading to cell survival, cell proliferation and tumour formation. The nuclear receptor Farnesoid X Receptor (FXR) is expressed in human breast cancer tissue and the breast cancer cell lines MCF-7 and MDA-MB-468. In these cells...

  17. Synergism of Antifungal Activity between Mitochondrial Respiration Inhibitors and Kojic Acid

    Directory of Open Access Journals (Sweden)

    Ronald P. Haff

    2013-01-01

    Full Text Available Co-application of certain types of compounds to conventional antimicrobial drugs can enhance the efficacy of the drugs through a process termed chemosensitization. We show that kojic acid (KA, a natural pyrone, is a potent chemosensitizing agent of complex III inhibitors disrupting the mitochondrial respiratory chain in fungi. Addition of KA greatly lowered the minimum inhibitory concentrations of complex III inhibitors tested against certain filamentous fungi. Efficacy of KA synergism in decreasing order was pyraclostrobin > kresoxim-methyl > antimycin A. KA was also found to be a chemosensitizer of cells to hydrogen peroxide (H2O2, tested as a mimic of reactive oxygen species involved in host defense during infection, against several human fungal pathogens and Penicillium strains infecting crops. In comparison, KA-mediated chemosensitization to complex III inhibitors/H2O2 was undetectable in other types of fungi, including Aspergillus flavus, A. parasiticus, and P. griseofulvum, among others. Of note, KA was found to function as an antioxidant, but not as an antifungal chemosensitizer in yeasts. In summary, KA could serve as an antifungal chemosensitizer to complex III inhibitors or H2O2 against selected human pathogens or Penicillium species. KA-mediated chemosensitization to H2O2 seemed specific for filamentous fungi. Thus, results indicate strain- and/or drug-specificity exist during KA chemosensitization.

  18. G37R SOD1 mutant alters mitochondrial complex I activity, Ca(2+) uptake and ATP production.

    NARCIS (Netherlands)

    Coussee, E.; Smet, P. De; Bogaert, E.; Elens, I.; Damme, P. van; Willems, P.H.G.M.; Koopman, W.J.H.; Bosch, L.; Callewaert, G.

    2011-01-01

    Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by selective death of motor neurons. Mutations in Cu/Zn superoxide dismutase-1 (SOD1) cause familial ALS but the molecular mechanisms whereby these mutations induce motor neuron death remain controversial. Here, we show

  19. Simulated microgravity alters multipotential differentiation of rat mesenchymal stem cells in association with reduced telomerase activity

    Science.gov (United States)

    Sun, Lianwen; Gan, Bo; Fan, Yubo; Xie, Tian; Hu, Qinghua; Zhuang, Fengyuan

    Microgravity is one of the most important characteristics in space flight. Exposure to microgravity results in extensive physiological changes in humans. Bone loss is one of the changes with serious consequences; however, the mechanism retains unclear. As the origin of osteoprogenitors, mesenchymal stem cells (MSCs) may play an important role in it. After cultured under simulated microgravity (in a rotary cell culture system, RCCS), MSCs were stained using oil red O to identify adipocytes. The mRNA level of bone morphogenetic protein (BMP)-2 and peroxisome proliferators-activated receptor (PPAR) γ2 was determined by RT-PCR. Otherwise, MSCs were induced to osteogenic differentiation after microgravity culture, and then the activity of alkaline phosphatase (ALP) was determined by PNPP and the content of osteocalcin (OC) by ELISA. Furthermore, the telomerase activity in MSCs was measured by TRAP. The results showed that simulated microgravity inhibited osteoblastic differentiation and induced adipogenic differentiation accompanied by the change of gene expression of BMP-2 and PPARγ2 in MSCs. Meanwhile, the telomerase activity decreased significantly in MSCs under simulated microgravity. The reduced bone formation in space flight may partly be due to the altered potential differentiation of MSCs associated with telomerase activity which plays a key role in regulating the lifespan of cell proliferation and differentiation. Therefore, telomerase activation/replacement may act as a potential countermeasure for microgravity-induced bone loss.

  20. Altered Brain Activities Associated with Neural Repetition Effects in Mild Cognitive Impairment Patients.

    Science.gov (United States)

    Yu, Jing; Li, Rui; Jiang, Yang; Broster, Lucas S; Li, Juan

    2016-05-11

    Older adults with mild cognitive impairment (MCI) manifest impaired explicit memory. However, studies on implicit memory such as repetition effects in persons with MCI have been limited. In the present study, 17 MCI patients and 16 healthy normal controls (NC) completed a modified delayed-match-to-sample task while undergoing functional magnetic resonance imaging. We aim to examine the neural basis of repetition; specifically, to elucidate whether and how repetition-related brain responses are altered in participants with MCI. When repeatedly rejecting distracters, both NC and MCI showed similar behavioral repetition effects; however, in both whole-brain and region-of-interest analyses of functional data, persons with MCI showed reduced repetition-driven suppression in the middle occipital and middle frontal gyrus. Further, individual difference analysis found that activation in the left middle occipital gyrus was positively correlated with rejecting reaction time and negatively correlated with accuracy rate, suggesting a predictor of repetition behavioral performance. These findings provide new evidence to support the view that neural mechanisms of repetition effect are altered in MCI who manifests compensatory repetition-related brain activities along with their neuropathology. PMID:27176074

  1. Maternal caffeine exposure alters neuromotor development and hippocampus acetylcholinesterase activity in rat offspring.

    Science.gov (United States)

    Souza, Ana Claudia; Souza, Andressa; Medeiros, Liciane Fernandes; De Oliveira, Carla; Scarabelot, Vanessa Leal; Da Silva, Rosane Souza; Bogo, Mauricio Reis; Capiotti, Katiucia Marques; Kist, Luiza Wilges; Bonan, Carla D; Caumo, Wolnei; Torres, Iraci L S

    2015-01-21

    The objective of this study was to evaluate the effects of maternal caffeine intake on the neuromotor development of rat offspring and on acetylcholine degradation and acetylcholinesterase (AChE) expression in the hippocampus of 14-day-old infant rats. Rat dams were treated with caffeine (0.3g/L) throughout gestation and lactation until the pups were 14 days old. The pups were divided into three groups: (1) control, (2) caffeine, and (3) washout caffeine. The washout group received a caffeine solution until the seventh postnatal day (P7). Righting reflex (RR) and negative geotaxis (NG) were assessed to evaluate postural parameters as an index of neuromotor reflexes. An open-field (OF) test was conducted to assess locomotor and exploratory activities as well as anxiety-like behaviors. Caffeine treatment increased both RR and NG latency times. In the OF test, the caffeine group had fewer outer crossings and reduced locomotion compared to control, while the washout group showed increased inner crossings in relation to the other groups and fewer rearings only in comparison to the control group. We found decreased AChE activity in the caffeine group compared to the other groups, with no alteration in AChE transcriptional regulation. Chronic maternal exposure to caffeine promotes important alterations in neuromotor development. These results highlight the ability of maternal caffeine intake to interfere with cholinergic neurotransmission during brain development. PMID:25451122

  2. Formation and Regulation of Mitochondrial Membranes

    Directory of Open Access Journals (Sweden)

    Laila Cigana Schenkel

    2014-01-01

    Full Text Available Mitochondrial membrane phospholipids are essential for the mitochondrial architecture, the activity of respiratory proteins, and the transport of proteins into the mitochondria. The accumulation of phospholipids within mitochondria depends on a coordinate synthesis, degradation, and trafficking of phospholipids between the endoplasmic reticulum (ER and mitochondria as well as intramitochondrial lipid trafficking. Several studies highlight the contribution of dietary fatty acids to the remodeling of phospholipids and mitochondrial membrane homeostasis. Understanding the role of phospholipids in the mitochondrial membrane and their metabolism will shed light on the molecular mechanisms involved in the regulation of mitochondrial function and in the mitochondrial-related diseases.

  3. Plectin isoform P1b and P1d deficiencies differentially affect mitochondrial morphology and function in skeletal muscle

    Science.gov (United States)

    Winter, Lilli; Kuznetsov, Andrey V.; Grimm, Michael; Zeöld, Anikó; Fischer, Irmgard; Wiche, Gerhard

    2015-01-01

    Plectin, a versatile 500-kDa cytolinker protein, is essential for muscle fiber integrity and function. The most common disease caused by mutations in the human plectin gene, epidermolysis bullosa simplex with muscular dystrophy (EBS-MD), is characterized by severe skin blistering and progressive muscular dystrophy. Besides displaying pathological desmin-positive protein aggregates and degenerative changes in the myofibrillar apparatus, skeletal muscle specimens of EBS-MD patients and plectin-deficient mice are characterized by massive mitochondrial alterations. In this study, we demonstrate that structural and functional alterations of mitochondria are a primary aftermath of plectin deficiency in muscle, contributing to myofiber degeneration. We found that in skeletal muscle of conditional plectin knockout mice (MCK-Cre/cKO), mitochondrial content was reduced, and mitochondria were aggregated in sarcoplasmic and subsarcolemmal regions and were no longer associated with Z-disks. Additionally, decreased mitochondrial citrate synthase activity, respiratory function and altered adenosine diphosphate kinetics were characteristic of plectin-deficient muscles. To analyze a mechanistic link between plectin deficiency and mitochondrial alterations, we comparatively assessed mitochondrial morphology and function in whole muscle and teased muscle fibers of wild-type, MCK-Cre/cKO and plectin isoform-specific knockout mice that were lacking just one isoform (either P1b or P1d) while expressing all others. Monitoring morphological alterations of mitochondria, an isoform P1b-specific phenotype affecting the mitochondrial fusion–fission machinery and manifesting with upregulated mitochondrial fusion-associated protein mitofusin-2 could be identified. Our results show that the depletion of distinct plectin isoforms affects mitochondrial network organization and function in different ways. PMID:26019234

  4. Pleiotropic effects of the yeast Sal1 and Aac2 carriers on mitochondrial function via an activity distinct from adenine nucleotide transport

    Science.gov (United States)

    Kucejova, Blanka; Li, Li; Wang, Xiaowen; Giannattasio, Sergio; Chen, Xin Jie

    2009-01-01

    In Saccharomyces cerevisiae, SAL1 encodes a Ca2+-binding mitochondrial carrier. Disruption of SAL1 is synthetically lethal with the loss of a specific function associated with the Aac2 isoform of the ATP/ADP translocase. This novel activity of Aac2 is defined as the V function (for Viability of aac2 sal1 double mutant), which is independent of the ATP/ADP exchange activity required for respiratory growth (the R function). We found that co-inactivation of SAL1 and AAC2 leads to defects in mitochondrial translation and mitochondrial DNA (mtDNA) maintenance. Additionally, sal1Δ exacerbates the respiratory deficiency and mtDNA instability of ggc1Δ, shy1Δ and mtg1Δ mutants, which are known to reduce mitochondrial protein synthesis or protein complex assembly. The V function is complemented by the human Short Ca2+-binding Mitochondrial Carrier (SCaMC) protein, SCaMC-2, a putative ATP-Mg/Pi exchangers on the inner membrane. However, mitochondria lacking both Sal1p and Aac2p are not depleted of adenine nucleotides. The Aac2R252I and Aac2R253I variants mutated at the R252-254 triplet critical for nucleotide transport retain the V function. Likewise, Sal1p remains functionally active when the R479I and R481I mutations were introduced into the structurally equivalent R479-T480-R481 motif. Finally, we found that the naturally occurring V-R+ Aac1 isoform of adenine nucleotide translocase partially gains the V function at the expense of the R function by introducing the mutations P89L and A96V. Thus, our data support the view that the V function is independent of adenine nucleotide transport associated with Sal1p and Aac2p and this evolutionarily conserved activity affects multiple processes in mitochondria. PMID:18431598

  5. Altered temporal variance and neural synchronization of spontaneous brain activity in anesthesia.

    Science.gov (United States)

    Huang, Zirui; Wang, Zhiyao; Zhang, Jianfeng; Dai, Rui; Wu, Jinsong; Li, Yuan; Liang, Weimin; Mao, Ying; Yang, Zhong; Holland, Giles; Zhang, Jun; Northoff, Georg

    2014-11-01

    Recent studies at the cellular and regional levels have pointed out the multifaceted importance of neural synchronization and temporal variance of neural activity. For example, neural synchronization and temporal variance has been shown by us to be altered in patients in the vegetative state (VS). This finding nonetheless leaves open the question of whether these abnormalities are specific to VS or rather more generally related to the absence of consciousness. The aim of our study was to investigate the changes of inter- and intra-regional neural synchronization and temporal variance of resting state activity in anesthetic-induced unconsciousness state. Applying an intra-subject design, we compared resting state activity in functional magnetic resonance imaging (fMRI) between awake versus anesthetized states in the same subjects. Replicating previous studies, we observed reduced functional connectivity within the default mode network (DMN) and thalamocortical network in the anesthetized state. Importantly, intra-regional synchronization as measured by regional homogeneity (ReHo) and temporal variance as measured by standard deviation (SD) of the BOLD signal were significantly reduced in especially the cortical midline regions, while increased in the lateral cortical areas in the anesthetized state. We further found significant frequency-dependent effects of SD in the thalamus, which showed abnormally high SD in Slow-5 (0.01-0.027 Hz) in the anesthetized state. Our results show for the first time of altered temporal variance of resting state activity in anesthesia. Combined with our findings in the vegetative state, these findings suggest a close relationship between temporal variance, neural synchronization and consciousness. PMID:24867379

  6. Stat1 activation attenuates IL-6 induced Stat3 activity but does not alter apoptosis sensitivity in multiple myeloma

    Directory of Open Access Journals (Sweden)

    Dimberg Lina Y

    2012-07-01

    Full Text Available Abstract Background Multiple myeloma (MM is at present an incurable malignancy, characterized by apoptosis-resistant tumor cells. Interferon (IFN treatment sensitizes MM cells to Fas-induced apoptosis and is associated with an increased activation of Signal transducer and activator of transcription (Stat1. The role of Stat1 in MM has not been elucidated, but Stat1 has in several studies been ascribed a pro-apoptotic role. Conversely, IL-6 induction of Stat3 is known to confer resistance to apoptosis in MM. Methods To delineate the role of Stat1 in IFN mediated sensitization to apoptosis, sub-lines of the U-266-1970 MM cell line with a stable expression of the active mutant Stat1C were utilized. The influence of Stat1C constitutive transcriptional activation on endogenous Stat3 expression and activation, and the expression of apoptosis-related genes were analyzed. To determine whether Stat1 alone would be an important determinant in sensitizing MM cells to apoptosis, the U-266-1970-Stat1C cell line and control cells were exposed to high throughput compound screening (HTS. Results To explore the role of Stat1 in IFN mediated apoptosis sensitization of MM, we established sublines of the MM cell line U-266-1970 constitutively expressing the active mutant Stat1C. We found that constitutive nuclear localization and transcriptional activity of Stat1 was associated with an attenuation of IL-6-induced Stat3 activation and up-regulation of mRNA for the pro-apoptotic Bcl-2 protein family genes Harakiri, the short form of Mcl-1 and Noxa. However, Stat1 activation alone was not sufficient to sensitize cells to Fas-induced apoptosis. In a screening of > 3000 compounds including bortezomib, dexamethasone, etoposide, suberoylanilide hydroxamic acid (SAHA, geldanamycin (17-AAG, doxorubicin and thalidomide, we found that the drug response and IC50 in cells constitutively expressing active Stat1 was mainly unaltered. Conclusion We conclude that Stat1 alters IL-6

  7. Exercise in rats does not alter hypothalamic AMP-activated protein kinase activity

    DEFF Research Database (Denmark)

    Andersson, Ulrika; Treebak, Jonas Thue; Nielsen, Jakob Nis;

    2005-01-01

    Recent studies have demonstrated that AMP-activated protein kinase (AMPK) in the hypothalamus is involved in the regulation of food intake. Because exercise is known to influence appetite and cause substrate depletion, it may also influence AMPK in the hypothalamus. Male rats that either rested or....... In recovery, glucose feeding increased plasma glucose and insulin concentrations whereas ghrelin and PYY decreased to (ghrelin) or below (PPY) resting levels. It is concluded that 1 h of strenuous exercise in rats does not elicit significant changes in hypothalamic AMPK activity despite an increase...... ran for 30 or 60 min on a treadmill (22 m/min, 10% slope) were sacrificed immediately after exercise or after 60 min recovery either in the fasted state or after oral gavage with glucose (3 g/kg body weight). Exercise decreased muscle and liver glycogen substantially. Hypothalamic total or a2...

  8. Fecal protease activity is associated with compositional alterations in the intestinal microbiota.

    Directory of Open Access Journals (Sweden)

    Ian M Carroll

    Full Text Available OBJECTIVE: Intestinal proteases carry out a variety of functions in the gastrointestinal (GI tract. Studies have reported that elevated enteric proteases in patients with GI disease can alter intestinal physiology, however the origin (human vs. microbial of elevated proteases in patients with GI disease is unclear. AIM: The aim of this study was to investigate the association between protease activity and the microbiota in human fecal samples. DESIGN: In order to capture a wide range of fecal protease (FP activity stool samples were collected from 30 IBS patients and 24 healthy controls. The intestinal microbiota was characterized using 454 high throughput pyro-sequencing of the 16S rRNA gene. The composition and diversity of microbial communities were determined and compared using the Quantitative Insights Into Microbial Ecology (QIIME pipeline. FP activity levels were determined using an ELISA-based method. FP activity was ranked and top and bottom quartiles (n=13 per quartile were identified as having high and low FP activity, respectively. RESULTS: The overall diversity of the intestinal microbiota displayed significant clustering separation (p = 0.001 between samples with high vs. low FP activity. The Lactobacillales, Lachnospiraceae, and Streptococcaceae groups were positively associated with FP activity across the entire study population, whilst the Ruminococcaceae family and an unclassified Coriobacteriales family were negatively associated with FP activity. CONCLUSIONS: These data demonstrate significant associations between specific intestinal bacterial groups and fecal protease activity and provide a basis for further causative studies investigating the role of enteric microbes and GI diseases.

  9. Mitochondrial localization and structure-based phosphate activation mechanism of Glutaminase C with implications for cancer metabolism

    International Nuclear Information System (INIS)

    Full text: Glutamine is an essential nutrient for cancer cell proliferation, especially in the context of citric acid cycle anaplerosis. In this manuscript we present results that collectively demonstrate that, of the three major mammalian glutaminases identified to date, the lesser studied splice variant of the gene gls, known as Glutaminase C (GAC), is important for tumor metabolism. We show that, although levels of both the kidney-type isoforms are elevated in tumor versus normal tissues, GAC is distinctly mitochondrial. GAC is also most responsive to the activator inorganic phosphate, the content of which is supposedly higher in mitochondria subject to hypoxia. Analysis of X-ray crystal structures of GAC in different bound states suggests a mechanism that introduces the tetramerization-induced lifting of a gating loop as essential for the phosphate-dependent activation process. Surprisingly, phosphate binds inside the catalytic pocket rather than at the oligomerization interface. It also mediates substrate entry by competing with glutamate. A greater tendency to oligomerize differentiates GAC from its alternatively spliced isoform and the cycling of phosphate in and out of the active site distinguishes it from the liver-type isozyme, which is known to be less dependent on this ion. (author)

  10. Anticancer Activity of γ-Bisabolene in Human Neuroblastoma Cells via Induction of p53-Mediated Mitochondrial Apoptosis

    Directory of Open Access Journals (Sweden)

    Yu-Jen Jou

    2016-05-01

    Full Text Available γ-Bisabolene has demonstrated antiproliferative activities against several human cancer cell lines. This study first discloses the antiproliferative and apoptosis induction activities of γ-bisabolene to human neuroblastoma TE671 cells. A CC50 value of γ-bisabolene was 8.2 μM to TE671 cells. Cell cycle analysis with PI staining showed γ-bisabolene elevating the sub-G1 fractions in a time-dependent manner. In addition, annexin V-FITC/PI staining showed γ-bisabolene significantly triggering early (annexin-V positive/PI negative and late (annexin-V positive/PI positive apoptosis in dose-dependent manners. γ-Bisabolene induced caspase 3/8/9 activation, intracellular ROS increase, and mitochondrial membrane potential decrease in apoptosis of human neuro-blastoma cells. Moreover, γ-bisabolene increased p53 phosphorylation and up-regulated p53-mediated apoptotic genes Bim and PUMA, as well as decreased the mRNA and protein levels of CK2α. Notably, the results indicated the involvement of CK2α-p53 pathways in mitochondria-mediated apoptosis of human neuroblastoma cells treated with γ-bisabolene. This study elucidated the apoptosis induction pathways of γ-bisabolene-treated neuroblastoma cells, in which could be useful for developing anti-neuroblastoma drugs.

  11. Anticancer Activity of γ-Bisabolene in Human Neuroblastoma Cells via Induction of p53-Mediated Mitochondrial Apoptosis.

    Science.gov (United States)

    Jou, Yu-Jen; Hua, Chun-Hung; Lin, Chen-Sheng; Wang, Ching-Ying; Wan, Lei; Lin, Ying-Ju; Huang, Su-Hua; Lin, Cheng-Wen

    2016-01-01

    γ-Bisabolene has demonstrated antiproliferative activities against several human cancer cell lines. This study first discloses the antiproliferative and apoptosis induction activities of γ-bisabolene to human neuroblastoma TE671 cells. A CC50 value of γ-bisabolene was 8.2 μM to TE671 cells. Cell cycle analysis with PI staining showed γ-bisabolene elevating the sub-G1 fractions in a time-dependent manner. In addition, annexin V-FITC/PI staining showed γ-bisabolene significantly triggering early (annexin-V positive/PI negative) and late (annexin-V positive/PI positive) apoptosis in dose-dependent manners. γ-Bisabolene induced caspase 3/8/9 activation, intracellular ROS increase, and mitochondrial membrane potential decrease in apoptosis of human neuro-blastoma cells. Moreover, γ-bisabolene increased p53 phosphorylation and up-regulated p53-mediated apoptotic genes Bim and PUMA, as well as decreased the mRNA and protein levels of CK2α. Notably, the results indicated the involvement of CK2α-p53 pathways in mitochondria-mediated apoptosis of human neuroblastoma cells treated with γ-bisabolene. This study elucidated the apoptosis induction pathways of γ-bisabolene-treated neuroblastoma cells, in which could be useful for developing anti-neuroblastoma drugs. PMID:27164076

  12. Fusion of the endoplasmic reticulum and mitochondrial outer membrane in rats brown adipose tissue: activation of thermogenesis by Ca2+.

    Science.gov (United States)

    de Meis, Leopoldo; Ketzer, Luisa A; da Costa, Rodrigo Madeiro; de Andrade, Ivone Rosa; Benchimol, Marlene

    2010-01-01

    Brown adipose tissue (BAT) mitochondria thermogenesis is regulated by uncoupling protein 1 (UCP 1), GDP and fatty acids. In this report, we observed fusion of the endoplasmic reticulum (ER) membrane with the mitochondrial outer membrane of rats BAT. Ca(2+)-ATPase (SERCA 1) was identified by immunoelectron microscopy in both ER and mitochondria. This finding led us to test the Ca(2+) effect in BAT mitochondria thermogenesis. We found that Ca(2+) increased the rate of respiration and heat production measured with a microcalorimeter both in coupled and uncoupled mitochondria, but had no effect on the rate of ATP synthesis. The Ca(2+) concentration needed for half-maximal activation varied between 0.08 and 0.11 microM. The activation of respiration was less pronounced than that of heat production. Heat production and ATP synthesis were inhibited by rotenone and KCN. Liver mitochondria have no UCP1 and during respiration synthesize a large amount of ATP, produce little heat, GDP had no effect on mitochondria coupling, Ca(2+) strongly inhibited ATP synthesis and had little or no effect on the small amount of heat released. These finding indicate that Ca(2+) activation of thermogenesis may be a specific feature of BAT mitochondria not found in other mitochondria such as liver. PMID:20209153

  13. Role of mitochondrial damage during cardiac apoptosis in septic rats

    Institute of Scientific and Technical Information of China (English)

    LI Li; HU Bang-chuan; CHEN Chang-qin; GONG Shi-jin; YU Yi-hua; DAI Hai-wen; YAN Jing

    2013-01-01

    Background Myocardial apoptosis is involved in the pathogenesis of sepsis-related myocardial depression.However,the underlying mechanism remains unknown.This study investigated the role of mitochondrial damage and mitochondria-induced oxidative stress during cardiac apoptosis in septic rats.Methods Seventy-two Sprague-Dawley rats were randomly divided into a control group and septic group receiving lipopolysaccharide injection.Heart tissue was removed and changes in cardiac morphology were observed by light microscopy and scanning electron microscopy.In situ apoptosis was examined using terminal transferase-mediated dUTP nick end-labeling assay and nuclear factor-kappa B activation in myocardium by Western blotting to estimate myocardial apoptosis.Appearance of mitochondrial cristae and activation of cytochrome C oxidase were used to evaluate mitochondrial damage.Oxidative stress was assessed by mitochondrial lipid and protein oxidation,and antioxidant defense was assessed by mitochondrial superoxide dismutase and glutathione peroxidase activity.Results Sepsis-induced inflammatory cell infiltration,myocardium degeneration and dropsy were time-dependent.Expanded capillaries were observed in the hearts of infected rats 24 hours post-challenge.Compared with sham-treated rats,the percentage of cell apoptosis increased in a time-dependent manner in hearts from septic rats at 6 hours,12 hours and 24 hours post-injection (P < 0.05).The expression of nuclear factor-kappa B p65 decreased gradually in the cytosol and increased in the nucleus during sepsis,indicating that septic challenge provoked the progressive activation of nuclear factor-kappa B.Mitochondrial cristae and activation of cytochrome C oxidase increased in a time-dependent manner.Both superoxide dismutase and glutathione peroxidase activities decreased,while mitochondrial lipid and protein oxidation increased between 6 and 24 hours after lipopolysaccharide challenge.Conclusions Septic challenge induced

  14. Perfluorooctanoic acid stimulated mitochondrial biogenesis and gene transcription in rats

    International Nuclear Information System (INIS)

    Perfluorooctanoic acid (PFOA), used in the production of non-stick surface compounds, exhibits a worldwide distribution in the serum of humans and wildlife. In rodents PFOA transactivates PPARα and PPARγ nuclear receptors and increases mitochondrial DNA (mtDNA) copy number, which may be critical to the altered metabolic state of affected animals. A key regulator of mitochondrial biogenesis and transcription of mitochondrial genes is the PPARγ coactivator-1α (Pgc-1α) protein. The purpose of this study was to determine if Pgc-1α is implicated in the stimulation of mitochondrial biogenesis that occurs following the treatment of rats with PFOA. Livers from adult male Sprague-Dawley rats that received a 30 mg/kg daily oral dose of PFOA for 28 days were used for all experiments. Analysis of mitochondrial replication and transcription was performed by real time PCR, and proteins were detected using western blotting. PFOA treatment caused a transcriptional activation of the mitochondrial biogenesis pathway leading to a doubling of mtDNA copy number. Further, transcription of OXPHOS genes encoded by mtDNA was 3-4 times greater than that of nuclear encoded genes, suggestive of a preferential induction of mtDNA transcription. Western blot analysis revealed an increase in Pgc-1α, unchanged Tfam and decreased Cox II and Cox IV subunit protein expression. We conclude that PFOA treatment in rats induces mitochondrial biogenesis at the transcriptional level with a preferential stimulation of mtDNA transcription and that this occurs by way of activation of the Pgc-1α pathway. Implication of the Pgc-1α pathway is consistent with PPARγ transactivation by PFOA and reveals new understanding and possibly new critical targets for assessing or averting the associated metabolic disease.

  15. Altered resting-state functional activity in posttraumatic stress disorder: A quantitative meta-analysis.

    Science.gov (United States)

    Wang, Ting; Liu, Jia; Zhang, Junran; Zhan, Wang; Li, Lei; Wu, Min; Huang, Hua; Zhu, Hongyan; Kemp, Graham J; Gong, Qiyong

    2016-01-01

    Many functional neuroimaging studies have reported differential patterns of spontaneous brain activity in posttraumatic stress disorder (PTSD), but the findings are inconsistent and have not so far been quantitatively reviewed. The present study set out to determine consistent, specific regional brain activity alterations in PTSD, using the Effect Size Signed Differential Mapping technique to conduct a quantitative meta-analysis of resting-state functional neuroimaging studies of PTSD that used either a non-trauma (NTC) or a trauma-exposed (TEC) comparison control group. Fifteen functional neuroimaging studies were included, comparing 286 PTSDs, 203 TECs and 155 NTCs. Compared with NTC, PTSD patients showed hyperactivity in the right anterior insula and bilateral cerebellum, and hypoactivity in the dorsal medial prefrontal cortex (mPFC); compared with TEC, PTSD showed hyperactivity in the ventral mPFC. The pooled meta-analysis showed hypoactivity in the posterior insula, superior temporal, and Heschl's gyrus in PTSD. Additionally, subgroup meta-analysis (non-medicated subjects vs. NTC) identified abnormal activation in the prefrontal-limbic system. In meta-regression analyses, mean illness duration was positively associated with activity in the right cerebellum (PTSD vs. NTC), and illness severity was negatively associated with activity in the right lingual gyrus (PTSD vs. TEC). PMID:27251865

  16. Mitochondrial DNA alterations correlate with the pathological status and the immunological ER, PR, HER-2/neu, p53 and Ki-67 expression in breast invasive ductal carcinoma.

    Science.gov (United States)

    Lin, Chen-Sung; Chang, Shi-Chuan; Ou, Liang-Hung; Chen, Chien-Ming; Hsieh, Sophie Swen-Wan; Chung, Yu-Ping; King, Kuang-Liang; Lin, Shoei-Loong; Wei, Yau-Huei

    2015-06-01

    We analyzed the changes in mitochondrial DNA (mtDNA) copy numbers and the shifting of mtDNA D310 sequence variations (D310 mutation) with their relationships to pathological status and the expression levels of estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor-2 (HER-2/neu), tumor-suppressor protein p53 and cellular proliferation protein Ki-67 in breast invasive ductal carcinoma (BIDC), respectively. Fifty-one paraffin-embedded BIDCs and their paired non-cancerous breast tissues were dissected for DNA extraction. The mtDNA copy number and mtDNA D310 sequence variations were determined by quantitative real-time polymerase chain reaction (q-PCR) and PCR-based direct sequencing, respectively. The expression levels of ER, PR, HER-2/neu, p53 and Ki-67 were determined by immunohistochemical (IHC) staining. Compared to the paired non-cancerous breast tissues, 24 (47.1%) BIDCs had elevated mtDNA copy numbers and 29 (56.9%) harbored mtDNA D310 mutations. Advanced T-status (p=0.056), negative-ER (p=0.005), negative-PR (p=0.007), positive-p53 (p=0.050) and higher Ki-67 (p=0.004) expressions were related to a higher mtDNA copy ratio. In addition, advanced T-status (p=0.019) and negative-HER-2/neu expression (p=0.061) were associated with mtDNA D310 mutations. In conclusion, higher mtDNA copy ratio and D310 mutations may be relevant biomarkers correlated with pathological T-status and the expression levels of ER, PR, HER-2/neu, p53 and Ki-67 in BIDCs. PMID:25845386

  17. CTRP9 induces mitochondrial biogenesis and protects high glucose-induced endothelial oxidative damage via AdipoR1 -SIRT1- PGC-1α activation.

    Science.gov (United States)

    Cheng, Liang; Li, Bin; Chen, Xu; Su, Jie; Wang, Hongbing; Yu, Shiqiang; Zheng, Qijun

    2016-09-01

    Vascular lesions caused by endothelial dysfunction are the most common and serious complication of diabetes. The vasoactive potency of CTRP9 has been reported in our previous study via nitric oxide (NO) production. However, the effect of CTRP9 on vascular endothelial cells remains unknown. This study aimed to investigate the protection role of CTRP9 in the primary aortic vascular endothelial cells and HAECs under high-glucose condition. We found that the aortic vascular endothelial cells isolated from mice fed with a high fat diet generated more ROS production than normal cells, along with decreased mitochondrial biogenesis, which was also found in HAECs treated with high glucose. However, the treatment of CTPR9 significantly reduced ROS production and increased the activities of endogenous antioxidant enzymes, the expression of PGC-1α, NRF1, TFAM, ATP5A1 and SIRT1, and the activity of cytochrome c oxidase, indicating an induction of mitochondrial biogenesis. Furthermore, silencing the expression of SIRT1 in HAECs impeded the effect of CTRP9 on mitochondrial biogenesis, while silencing the expression of AdipoR1 in HAECs reversed the expression of SIRT1 and PGC-1α. Based on these findings, this study showed that CTRP9 might induce mitochondrial biogenesis and protect high glucose-induced endothelial oxidative damage via AdipoR1-SIRT1-PGC-1α signaling pathway. PMID:27349872

  18. Identification of the Mitochondrial ND3 Subunit as a Structural Component Involved in the Active/Deactive Enzyme Transition of Respiratory Complex I*S⃞

    OpenAIRE

    Galkin, Alexander; Meyer, Björn; Wittig, Ilka; Karas, Michael; Schägger, Hermann; Vinogradov, Andrei; Brandt, Ulrich

    2008-01-01

    Mitochondrial complex I (NADH:ubiquinone oxidoreductase) undergoes reversible deactivation upon incubation at 30–37 °C. The active/deactive transition could play an important role in the regulation of complex I activity. It has been suggested recently that complex I may become modified by S-nitrosation under pathological conditions during hypoxia or when the nitric oxide:oxygen ratio increases. Apparently, a specific cysteine becomes accessible to chemical modification...

  19. The alterations in biochemical signaling of hippocampal network activity in the autism brain The alterations in biochemical signaling of hippocampal network activity in the autism brain The alterations in biochemical signaling of hippocampal network activity in the autism brain

    Institute of Scientific and Technical Information of China (English)

    田允; 黄继云; 王锐; 陶蓉蓉; 卢应梅; 廖美华; 陆楠楠; 李静; 芦博; 韩峰

    2012-01-01

    Autism is a highly heritable neurodevelopmental condition characterized by impaired social interaction and communication. However, the role of synaptic dysfunction during development of autism remains unclear. In the present study, we address the alterations of biochemical signaling in hippocampal network following induction of the autism in experimental animals. Here, the an- imal disease model and DNA array being used to investigate the differences in transcriptome or- ganization between autistic and normal brain by gene co--expression network analysis.

  20. Altered activity of the medial prefrontal cortex and amygdala during acquisition and extinction of an active avoidance task

    Directory of Open Access Journals (Sweden)

    Xilu eJiao

    2015-09-01

    Full Text Available Altered medial prefrontal cortex (mPFC and amygdala function is associated with anxiety-related disorders. While the mPFC-amygdala pathway has a clear role in fear conditioning, these structures are also involved in active avoidance. Given that avoidance perseveration represents a core symptom of anxiety disorders, the neural substrate of avoidance, especially its extinction, requires better understanding. The present study was designed to investigate the activity of mPFC and amygdala neurons during acquisition and extinction of lever-press avoidance in rats. In particular, neural activity was examined in the mPFC, intercalated cell clusters (ITCs, lateral (LA, basal (BA and central (CeA amygdala, at various time points during acquisition and extinction, using induction of the immediate early gene product, c-Fos. Neural activity was greater in the mPFC, LA, BA, and ITC during the extinction phase as compared to the acquisition phase. In contrast, the CeA was the only region that was more activated during acquisition than during extinction. Our results indicate that elevated activity in the mPFC, BA, LA and ITCs, and reduced CeA activity is associated with extinction of active avoidance. Moreover, inhibitory neurons are activated differently in the mPFC and BA during early and late phase of acquisition and extinction, suggesting their dynamic involvement in the development of avoidance response. Together, these data start to identify the key brain regions important in active avoidance behavior, areas that could be associated with avoidance perseveration in anxiety disorders.

  1. TRPV1 Activation Exacerbates Hypoxia/Reoxygenation-Induced Apoptosis in H9C2 Cells via Calcium Overload and Mitochondrial Dysfunction

    Directory of Open Access Journals (Sweden)

    Zewei Sun

    2014-10-01

    Full Text Available Transient potential receptor vanilloid 1 (TRPV1 channels, which are expressed on sensory neurons, elicit cardioprotective effects during ischemia reperfusion injury by stimulating the release of neuropeptides, namely calcitonin gene-related peptide (CGRP and substance P (SP. Recent studies show that TRPV1 channels are also expressed on cardiomyocytes and can exacerbate air pollutant-induced apoptosis. However, whether these channels present on cardiomyocytes directly modulate cell death and survival pathways during hypoxia/reoxygenation (H/R injury remains unclear. In the present study, we investigated the role of TRPV1 in H/R induced apoptosis of H9C2 cardiomyocytes. We demonstrated that TRPV1 was indeed expressed in H9C2 cells, and activated by H/R injury. Although neuropeptide release caused by TRPV1 activation on sensory neurons elicits a cardioprotective effect, we found that capsaicin (CAP; a TRPV1 agonist treatment of H9C2 cells paradoxically enhanced the level of apoptosis by increasing intracellular calcium and mitochondrial superoxide levels, attenuating mitochondrial membrane potential, and inhibiting mitochondrial biogenesis (measured by the expression of ATP synthase β. In contrast, treatment of cells with capsazepine (CPZ; a TRPV1 antagonist or TRPV1 siRNA attenuated H/R induced-apoptosis. Furthermore, CAP and CPZ treatment revealed a similar effect on cell viability and mitochondrial superoxide production in primary cardiomyocytes. Finally, using both CGRP8–37 (a CGRP receptor antagonist and RP67580 (a SP receptor antagonist to exclude the confounding effects of neuropeptides, we confirmed aforementioned detrimental effects as TRPV1−/− mouse hearts exhibited improved cardiac function during ischemia/reperfusion. In summary, direct activation of TRPV1 in myocytes exacerbates H/R-induced apoptosis, likely through calcium overload and associated mitochondrial dysfunction. Our study provides a novel understanding of the role of

  2. Leptin in nucleus of the solitary tract alters the cardiovascular responses to aortic baroreceptor activation.

    Science.gov (United States)

    Ciriello, John

    2013-06-01

    Recent data suggests that neurons expressing the long form of the leptin receptor form at least two distinct groups within the caudal nucleus of the solitary tract (NTS): a group within the lateral NTS (Slt) and one within the medial (Sm) and gelantinosa (Sg) NTS. Discrete injections of leptin into Sm and Sg, a region that receives chemoreceptor input, elicit increases in arterial pressure (AP) and renal sympathetic nerve activity (RSNA). However, the effect of microinjections of leptin into Slt, a region that receives baroreceptor input is unknown. Experiments were done in the urethane-chloralose anesthetized, paralyzed and artificially ventilated Wistar or Zucker obese rat to determine leptin's effect in Slt on heart rate (HR), AP and RSNA during electrical stimulation of the aortic depressor nerve (ADN). Depressor sites within Slt were first identified by the microinjection of l-glutamate (Glu; 0.25M; 10nl) followed by leptin microinjections. In the Wistar rat leptin microinjection (50ng; 20nl) into depressor sites within the lateral Slt elicited increases in HR and RSNA, but no changes in AP. Additionally, leptin injections into Slt prior to Glu injections at the same site or to stimulation of the ADN were found to attenuate the decreases in HR, AP and RSNA to both the Glu injection and ADN stimulation. In Zucker obese rats, leptin injections into NTS depressor sites did not elicit cardiovascular responses, nor altered the cardiovascular responses elicited by stimulation of ADN. Those data suggest that leptin acts at the level of NTS to alter the activity of neurons that mediate the cardiovascular responses to activation of the aortic baroreceptor reflex. PMID:23535030

  3. Mitochondrial Diseases

    Science.gov (United States)

    ... in your body tissues. If you have a metabolic disorder, something goes wrong with this process. Mitochondrial diseases are a group of metabolic disorders. Mitochondria are small structures that produce energy in ...

  4. Altered default mode network activity in patient with anxiety disorders: An fMRI study

    International Nuclear Information System (INIS)

    Anxiety disorder, a common mental disorder in our clinical practice, is characterized by unprovoked anxiety. Medial prefrontal cortex (MPFC) and posterior cingulate cortex (PCC), which closely involved in emotional processing, are critical regions in the default mode network. We used functional magnetic resonance imaging (fMRI) to investigate whether default mode network activity is altered in patients with anxiety disorder. Ten anxiety patients and 10 healthy controls underwent fMRI while listening to emotionally neutral words alternating with rest (Experiment 1) and threat-related words alternating with emotionally neutral words (Experiment 2). In Experiment 1, regions of deactivation were observed in patients and controls. In Experiment 2, regions of deactivation were observed only in patients. The observed deactivation patterns in the two experiments, which included MPFC, PCC, and inferior parietal cortex, were similar and consistent with the default model network. Less deactivation in MPFC and greater deactivation in PCC were observed for patients group comparing to controls in Experiment 1. Our observations suggest that the default model network is altered in anxiety patients and dysfunction in MPFC and PCC may play an important role in anxiety psychopathology

  5. Leukemia-associated activating mutation of Flt3 expands dendritic cells and alters T cell responses.

    Science.gov (United States)

    Lau, Colleen M; Nish, Simone A; Yogev, Nir; Waisman, Ari; Reiner, Steven L; Reizis, Boris

    2016-03-01

    A common genetic alteration in acute myeloid leukemia is the internal tandem duplication (ITD) in FLT3, the receptor for cytokine FLT3 ligand (FLT3L). Constitutively active FLT3-ITD promotes the expansion of transformed progenitors, but also has pleiotropic effects on hematopoiesis. We analyzed the effect of FLT3-ITD on dendritic cells (DCs), which express FLT3 and can be expanded by FLT3L administration. Pre-leukemic mice with the Flt3(ITD) knock-in allele manifested an expansion of classical DCs (cDCs) and plasmacytoid DCs. The expansion originated in DC progenitors, was cell intrinsic, and was further enhanced in Flt3(ITD/ITD) mice. The mutation caused the down-regulation of Flt3 on the surface of DCs and reduced their responsiveness to Flt3L. Both canonical Batf3-dependent CD8(+) cDCs and noncanonical CD8(+) cDCs were expanded and showed specific alterations in their expression profiles. Flt3(ITD) mice showed enhanced capacity to support T cell proliferation, including a cell-extrinsic expansion of regulatory T (T reg) cells. Accordingly, these mice restricted alloreactive T cell responses during graft-versus-host reaction, but failed to control autoimmunity without T reg cells. Thus, the FLT3-ITD mutation directly affects DC development, indirectly modulating T cell homeostasis and supporting T reg cell expansion. We hypothesize that this effect of FLT3-ITD might subvert immunosurveillance and promote leukemogenesis in a cell-extrinsic manner. PMID:26903243

  6. Altered default mode network activity in patient with anxiety disorders: An fMRI study

    Energy Technology Data Exchange (ETDEWEB)

    Zhao Xiaohu [Imaging Department of Tong Ji Hospital of Tong Ji University, Shanghai 200065 (China) and Bio-X lab, Department of Physics, Zhe Jiang University, Hangzhou 310027 (China)], E-mail: xhzhao999@263.net; Wang Peijun [Imaging Department of Tong Ji Hospital of Tong Ji University, Shanghai 200065 (China)], E-mail: tongjipjwang@vip.sina.com; Li Chunbo [Department of Psychiatry, Tong Ji Hospital of Tong Ji University, Shanghai 200065 (China)], E-mail: licb@mail.tongji.edu.cn; Hu Zhenghui [Department of Electrical and Engineering, Hong Kong University of Science and Technology, Hong Kong (China)], E-mail: eezhhu@ust.hk; Xi Qian [Imaging Department of Tong Ji Hospital of Tong Ji University, Shanghai 200065 (China)], E-mail: 96125007@sina.com.cn; Wu Wenyuan [Department of Psychiatry, Tong Ji Hospital of Tong Ji University, Shanghai 200065 (China)], E-mail: wuwy@mail.tongji.edu.cn; Tang Xiaowei [Bio-X lab, Department of Physics, Zhe Jiang University, Hangzhou 310027 (China)], E-mail: tangxw@zju.edu.cn

    2007-09-15

    Anxiety disorder, a common mental disorder in our clinical practice, is characterized by unprovoked anxiety. Medial prefrontal cortex (MPFC) and posterior cingulate cortex (PCC), which closely involved in emotional processing, are critical regions in the default mode network. We used functional magnetic resonance imaging (fMRI) to investigate whether default mode network activity is altered in patients with anxiety disorder. Ten anxiety patients and 10 healthy controls underwent fMRI while listening to emotionally neutral words alternating with rest (Experiment 1) and threat-related words alternating with emotionally neutral words (Experiment 2). In Experiment 1, regions of deactivation were observed in patients and controls. In Experiment 2, regions of deactivation were observed only in patients. The observed deactivation patterns in the two experiments, which included MPFC, PCC, and inferior parietal cortex, were similar and consistent with the default model network. Less deactivation in MPFC and greater deactivation in PCC were observed for patients group comparing to controls in Experiment 1. Our observations suggest that the default model network is altered in anxiety patients and dysfunction in MPFC and PCC may play an important role in anxiety psychopathology.

  7. Mitochondrial efficiency and insulin resistance.

    Science.gov (United States)

    Crescenzo, Raffaella; Bianco, Francesca; Mazzoli, Arianna; Giacco, Antonia; Liverini, Giovanna; Iossa, Susanna

    2014-01-01

    Insulin resistance, "a relative impairment in the ability of insulin to exert its effects on glucose, protein and lipid metabolism in target tissues," has many detrimental effects on metabolism and is strongly correlated to deposition of lipids in non-adipose tissues. Mitochondria are the main cellular sites devoted to ATP production and fatty acid oxidation. Therefore, a role for mitochondrial dysfunction in the onset of skeletal muscle insulin resistance has been proposed and many studies have dealt with possible alteration in mitochondrial function in obesity and diabetes, both in humans and animal models. Data reporting evidence of mitochondrial dysfunction in type two diabetes mellitus are numerous, even though the issue that this reduced mitochondrial function is causal in the development of the disease is not yet solved, also because a variety of parameters have been used in the studies carried out on this subject. By assessing the alterations in mitochondrial efficiency as well as the impact of this parameter on metabolic homeostasis of skeletal muscle cells, we have obtained results that allow us to suggest that an increase in mitochondrial efficiency precedes and therefore can contribute to the development of high-fat-induced insulin resistance in skeletal muscle. PMID:25601841

  8. A unique horizontal gene transfer event has provided the octocoral mitochondrial genome with an active mismatch repair gene that has potential for an unusual self-contained function

    Directory of Open Access Journals (Sweden)

    Bilewitch Jaret P

    2011-07-01

    Full Text Available Abstract Background The mitochondrial genome of the Octocorallia has several characteristics atypical for metazoans, including a novel gene suggested to function in DNA repair. This mtMutS gene is favored for octocoral molecular systematics, due to its high information content. Several hypotheses concerning the origins of mtMutS have been proposed, and remain equivocal, although current weight of support is for a horizontal gene transfer from either an epsilonproteobacterium or a large DNA virus. Here we present new and compelling evidence on the evolutionary origin of mtMutS, and provide the very first data on its activity, functional capacity and stability within the octocoral mitochondrial genome. Results The mtMutS gene has the expected conserved amino acids, protein domains and predicted tertiary protein structure. Phylogenetic analysis indicates that mtMutS is not a member of the MSH family and therefore not of eukaryotic origin. MtMutS clusters closely with representatives of the MutS7 lineage; further support for this relationship derives from the sharing of a C-terminal endonuclease domain that confers a self-contained mismatch repair function. Gene expression analyses confirm that mtMutS is actively transcribed in octocorals. Rates of mitochondrial gene evolution in mtMutS-containing octocorals are lower than in their hexacoral sister-group, which lacks the gene, although paradoxically the mtMutS gene itself has higher rates of mutation than other octocoral mitochondrial genes. Conclusions The octocoral mtMutS gene is active and codes for a protein with all the necessary components for DNA mismatch repair. A lower rate of mitochondrial evolution, and the presence of a nicking endonuclease domain, both indirectly support a theory of self-sufficient DNA mismatch repair within the octocoral mitochondrion. The ancestral affinity of mtMutS to non-eukaryotic MutS7 provides compelling support for an origin by horizontal gene transfer. The

  9. Amyloid-β alters ongoing neuronal activity and excitability in the frontal cortex.

    Science.gov (United States)

    Kellner, Vered; Menkes-Caspi, Noa; Beker, Shlomit; Stern, Edward A

    2014-09-01

    The effects of amyloid-β on the activity and excitability of individual neurons in the early and advanced stages of the pathological progression of Alzheimer's disease remain unknown. We used in vivo intracellular recordings to measure the ongoing and evoked activity of pyramidal neurons in the frontal cortex of APPswe/PS1dE9 transgenic mice and age-matched nontransgenic littermate controls. Evoked excitability was altered in both transgenic groups: neurons in young transgenic mice displayed hypoexcitability, whereas those in older transgenic mice displayed hyperexcitability, suggesting changes in intrinsic electrical properties of the neurons. However, the ongoing activity of neurons in both young and old transgenic groups showed signs of hyperexcitability in the depolarized state of the membrane potential. The membrane potential of neurons in old transgenic mice had an increased tendency to fail to transition to the depolarized state, and the depolarized states had shorter durations on average than did controls. This suggests a combination of both intrinsic electrical and synaptic dysfunctions as mechanisms for activity changes at later stages of the neuropathological progression. PMID:24792906

  10. Phosphorylation or Mutation of the ERK2 Activation Loop Alters Oligonucleotide Binding.

    Science.gov (United States)

    McReynolds, Andrea C; Karra, Aroon S; Li, Yan; Lopez, Elias Daniel; Turjanski, Adrian G; Dioum, Elhadji; Lorenz, Kristina; Zaganjor, Elma; Stippec, Steve; McGlynn, Kathleen; Earnest, Svetlana; Cobb, Melanie H

    2016-03-29

    The mitogen-activated protein kinase ERK2 is able to elicit a wide range of context-specific responses to distinct stimuli, but the mechanisms underlying this versatility remain in question. Some cellular functions of ERK2 are mediated through regulation of gene expression. In addition to phosphorylating numerous transcriptional regulators, ERK2 is known to associate with chromatin and has been shown to bind oligonucleotides directly. ERK2 is activated by the upstream kinases MEK1/2, which phosphorylate both tyrosine 185 and threonine 183. ERK2 requires phosphorylation on both sites to be fully active. Some additional ERK2 phosphorylation sites have also been reported, including threonine 188. It has been suggested that this phospho form has distinct properties. We detected some ERK2 phosphorylated on T188 in bacterial preparations of ERK2 by mass spectrometry and further demonstrate that phosphomimetic substitution of this ERK2 residue impairs its kinase activity toward well-defined substrates and also affects its DNA binding. We used electrophoretic mobility shift assays with oligonucleotides derived from the insulin gene promoter and other regions to examine effects of phosphorylation and mutations on the binding of ERK2 to DNA. We show that ERK2 can bind oligonucleotides directly. Phosphorylation and mutations alter DNA binding and support the idea that signaling functions may be influenced through an alternate phosphorylation site. PMID:26950759

  11. Functional insights into modulation of BKCa channel activity to alter myometrial contractility

    Directory of Open Access Journals (Sweden)

    RamónALorca

    2014-07-01

    Full Text Available The large-conductance voltage- and Ca2+-activated K+ channel (BKCa is an important regulator of membrane excitability in a wide variety of cells and tissues. In myometrial smooth muscle, activation of BKCa plays essential roles in buffering contractility to maintain uterine quiescence during pregnancy and in the transition to a more contractile state at the onset of labor. Multiple mechanisms of modulation have been described to alter BKCa channel activity, expression, and cellular localization. In the myometrium, BKCa is regulated by alternative splicing, protein targeting to the plasma membrane, compartmentation in membrane microdomains, and posttranslational modifications. In addition, interaction with auxiliary proteins (i.e., β1- and β2-subunits, association with G-protein coupled receptor signaling pathways, such as those activated by adrenergic and oxytocin receptors, and hormonal regulation provide further mechanisms of variable modulation of BKCa channel function in myometrial smooth muscle. Here, we provide an overview of these mechanisms of BKCa channel modulation and provide a context for them in relation to myometrial function.

  12. Guanidination of notexin alters its membrane-damaging activity in response to sphingomyelin and cholesterol

    Indian Academy of Sciences (India)

    Pei-Hsiu Kao; Yi-Ling Chiou; Shinne-Ren Lin; Long-Sen Chang

    2010-12-01

    To elucidate the contribution of phospholipase A2 (PLA2) activity of notexin to its ability to perturb membranes, comparative studies on the interaction of notexin and guanidinated notexin (Gu-notexin) with egg yolk phosphatidylcholine (EYPC), EYPC/egg yolk sphingomyelin (EYSM) and EYPC/EYSM/cholesterol vesicles were conducted. EYSM notably reduced the membrane-damaging activity of notexin against EYPC vesicles, but had an insignificant influence on that of Gu-notexin. Unlike the effects noted with notexin, inactivation of PLA2 activity by EDTA led to a reduction in the ability of Gu-notexin to induce EYPC/EYSM vesicle leakage and to increase Gu-notexin-induced membrane permeability of EYPC/EYSM/cholesterol vesicles. The geometrical arrangement of notexin and Gu-notexin in contact with either EYPC/EYSM vesicles or EYPC/EYSM/cholesterol vesicles differed. Moreover, global conformation of notexin and Gu-notexin differed in either Ca2+-bound or metal-free states. These results indicate that notexin and Gu-notexin could induce membrane permeability without the involvement of PLA2 activity, and suggest that guanidination alters the membrane-bound mode of notexin on damaging phospholipid vesicles containing sphingomyelin and cholesterol.

  13. Inhibition of Dual Specific Oncolytic Adenovirus on Esophageal Cancer via Activation of Caspases by a Mitochondrial-dependent Pathway

    Institute of Scientific and Technical Information of China (English)

    SU Jia-qiang; CHI Bao-rong; LI Xiao; LIU Lei; LIU Li-ming; QI Yan-xin; WANG Zhuo-yue; JIN Ning-yi

    2012-01-01

    We investigated the anti-tumor effects of dual cancer specific-oncolytic adenovirus Ad-VP on esophageal cancer(EC).The anti-tumor activity of Ad-VP was compared with that of the control recombinant adenoviruses (Ad-GP,Ad-Apoptin,Ad-EGFP) in human esophageal cancer cell EC-109 and human normal liver cell L02 in vitro.In 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT) assays,the growth of EC-109 cells was slightly inhibited by Ad-GP.Ad-Apoptin and Ad-EGFP.However,Ad-VP induced a significant cytotoxic effect.Infection of EC-109 cells with Ad-VP resulted in a significant induction of apoptosis of them in vitro,detected by 4′,6-diamidino-2-phenylindole(DAPI) or acridine orange and ethidium bromide staining.The results of Western blot and flow cytometric assay indicate the loss of mitochondrial membrane potential(△ψm),the release of cytochrome c and the activation of caspase-3,6 and 7 in Ad-VP infiected EC-109 cells.In contrast,all these assays show almost no effects of the recombinant adenoviruses on L02 cells.These results demonstrate that the treatment of tumors with Ad-VP selectively inhibits tumor growth and induces apoptosis of esophageal cancer cells.Ad-VP may provide a novel and powerful strategy for cancer gene therapy.

  14. Parthenolide induces apoptosis by activating the mitochondrial and death receptor pathways and inhibits FAK-mediated cell invasion.

    Science.gov (United States)

    Kwak, Sang Won; Park, Eon Sub; Lee, Chung Soo

    2014-01-01

    The natural product parthenolide induces apoptosis in cancer cells. However, the mechanism of apoptosis in ovarian cancer cells exposed to parthenolide is not clear. In addition, it is unclear whether parthenolide-induced apoptosis is mediated by the formation of reactive oxygen species and the depletion of GSH contents, and the effect of parthenolide on the invasion and migration of human epithelial ovarian cancer cells has not been studied. Therefore, we investigated the effects of parthenolide exposure on apoptosis, cell adhesion, and migration using the human epithelial ovarian carcinoma cell lines OVCAR-3 and SK-OV-3. The results suggest that parthenolide may induce apoptotic cell death in ovarian carcinoma cell lines by activating the mitochondrial pathway and the caspase-8- and Bid-dependent pathways. The apoptotic effect of parthenolide appears to be mediated by the formation of reactive oxygen species and the depletion of GSH. Parthenolide inhibited fetal bovine serum-induced cell adhesion and migration of OVCAR-3 cells, possibly through the suppression the focal adhesion kinase-dependent activation of cytoskeletal-associated components. Therefore, parthenolide might be beneficial in the treatment of epithelial ovarian adenocarcinoma and combination therapy. PMID:24065392

  15. Platelet mitochondrial membrane potential in Parkinson's disease

    OpenAIRE

    Antony, P.M.; Boyd, O.; Trefois, C.; Ammerlaan, W; Ostaszewski, M.; Baumuratov, A.S.; Longhino, L.; Antunes, L; Koopman, W.J.H.; Balling, R; Diederich, N.J.

    2014-01-01

    OBJECTIVE: Mitochondrial dysfunction is a hallmark of idiopathic Parkinson's disease (IPD), which has been reported not to be restricted to striatal neurons. However, studies that analyzed mitochondrial function at the level of selected enzymatic activities in peripheral tissues have produced conflicting data. We considered the electron transport chain as a complex system with mitochondrial membrane potential as an integrative indicator for mitochondrial fitness. METHODS: Twenty-five IPD pati...

  16. Whole Blood Activation Results in Altered T Cell and Monocyte Cytokine Production Profiles by Flow Cytometry

    Science.gov (United States)

    Crucian, Brian E.; Sams, Clarence F.

    2001-01-01

    An excellent monitor of the immune balance of peripheral circulating cells is to determine their cytokine production patterns in response to stimuli. Using flow cytometry, a positive identification of cytokine producing cells in a mixed culture may be achieved. Recently, the ability to assess cytokine production following a whole-blood activation culture has been described. In this study, whole blood activation was compared to traditional PBMC activation and the individual cytokine secretion patterns for both T cells, T cell subsets and monocytes was determined by flow cytometry. RESULTS: For T cell cytokine assessment (IFNg/IL-10 and IL-21/L-4) following PMA +ionomycin activation: (1) a Significantly greater percentages of T cells producing IFNgamma and IL-2 were observed following whole-blood culture and (2) altered T cell cytokine production kinetics were observed by varying whole blood culture times. Four-color analysiS was used to allow assessment of cytokine production by specific T cell subsets. It was found that IFNgamma production was significantly elevated in the CD3+/CD8+ T cell population as compared to the CD3+/CD8- population following five hours of whole blood activation. Conversely, IL-2 and IL-10 production were Significantly elevated in the CD3+/CD8- T cell population as compared to the CD3+/CD8+ population. Monocyte cytokine production was assessed in both culture systems following LPS activation for 24 hours. A three-color flow cytometric was used to assess two cytokines (IL-1a/IL-12 and TNFa/IL-10) in conjunction with CD14. Nearly all monocytes were stimulated to produce IL-1a, IL-12 and TNFa. equally well in both culture systems, however monocyte production of IL-10 was significantly elevated in whole blood culture as compared to PBMC culture. IL-12 producing monocytes appeared to be a distinct subpopulation of the IL-1a producing set, whereas IL-10 and TNFa producing monocytes were largely mutually exclusive. IL-10 and TNFa producing

  17. Mitochondrial uncoupler carbonyl cyanide M-chlorophenylhydrazone induces the multimer assembly and activity of repair enzyme protein L-isoaspartyl methyltransferase.

    Science.gov (United States)

    Fanélus, Irvens; Desrosiers, Richard R

    2013-07-01

    The protein L-isoaspartyl methyltransferase (PIMT) repairs damaged aspartyl residues in proteins. It is commonly described as a cytosolic protein highly expressed in brain tissues. Here, we report that PIMT is an active monomeric as well as a multimeric protein in mitochondria isolated from neuroblastoma cells. Upon treatments with mitochondrial uncoupler carbonyl cyanide m-chlorophenylhydrazone (CCCP), PIMT monomers level decreased by half while that of PIMT multimers was higher. Gel electrophoresis under reducing conditions of CCCP-induced PIMT multimers led to PIMT monomers accumulation, indicating that multimers resulted from disulfide-linked PIMT monomers. The antioxidant ascorbic acid significantly lowered CCCP-induced formation of PIMT multimers, suggesting that reactive oxygen species contributed to PIMT multimerization. In addition, the elevation of PIMT multimers catalytic activity upon treatments with CCCP was severely inhibited by the reducing agent dithiothreitol. This indicated that PIMT monomers have lower enzymatic activity following CCCP treatments and that activation of PIMT multimers is essentially dependent on the formation of disulfide-linked monomers of PIMT. Furthermore, the perturbation of mitochondrial function by CCCP promoted the accumulation of damaged aspartyl residues in proteins with high molecular weights. Thus, this study demonstrates the formation of active PIMT multimers associated with mitochondria that could play a key role in repairing damaged proteins accumulating during mitochondrial dysfunction. PMID:23319267

  18. Effect of p53 on mitochondrial morphology, import, and assembly in skeletal muscle.

    Science.gov (United States)

    Saleem, Ayesha; Iqbal, Sobia; Zhang, Yuan; Hood, David A

    2015-02-15

    The purpose of this study was to investigate whether p53 regulates mitochondrial function via changes in mitochondrial protein import, complex IV (COX) assembly, or the expression of key proteins involved in mitochondrial dynamics and degradation. Mitochondria from p53 KO mice displayed ultra-structural alterations and were more punctate in appearance. This was accompanied by protein-specific alterations in fission, fusion, and mitophagy-related proteins. However, matrix-destined protein import into subsarcolemmal or intermyofibrillar mitochondria was unaffected in the absence of p53, despite mitochondrial subfraction-specific reductions in Tom20, Tim23, mtHsp70, and mtHsp60 in the knockout (KO) mitochondria. Complex IV activity in isolated mitochondria was also unchanged in KO mice, but two-dimensional blue native-PAGE revealed a reduction in the assembly of complex IV within the IMF fractions from KO mice in tandem with lower levels of the assembly protein Surf1. This observed defect in complex IV assembly may facilitate the previously documented impairment in mitochondrial function in p53 KO mice. We suspect that these morphological and functional impairments in mitochondria drive a decreased reliance on mitochondrial respiration as a means of energy production in skeletal muscle in the absence of p53. PMID:25472962

  19. Cerebrospinal Fluid from Sporadic Amyotrophic Lateral Sclerosis Patients Induces Mitochondrial and Lysosomal Dysfunction.

    Science.gov (United States)

    Sharma, Aparna; Varghese, Anu Mary; Vijaylakshmi, Kalyan; Sumitha, Rajendrarao; Prasanna, V K; Shruthi, S; Chandrasekhar Sagar, B K; Datta, Keshava K; Gowda, Harsha; Nalini, Atchayaram; Alladi, Phalguni Anand; Christopher, Rita; Sathyaprabha, Talakad N; Raju, Trichur R; Srinivas Bharath, M M

    2016-05-01

    In our laboratory, we have developed (1) an in vitro model of sporadic Amyotrophic Lateral Sclerosis (sALS) involving exposure of motor neurons to cerebrospinal fluid (CSF) from sALS patients and (2) an in vivo model involving intrathecal injection of sALS-CSF into rat pups. In the current study, we observed that spinal cord extract from the in vivo sALS model displayed elevated reactive oxygen species (ROS) and mitochondrial dysfunction. Quantitative proteomic analysis of sub-cellular fractions from spinal cord of the in vivo sALS model revealed down-regulation of 35 mitochondrial proteins and 4 lysosomal proteins. Many of the down-regulated mitochondrial proteins contribute to alterations in respiratory chain complexes and organellar morphology. Down-regulated lysosomal proteins Hexosaminidase, Sialidase and Aryl sulfatase also displayed lowered enzyme activity, thus validating the mass spectrometry data. Proteomic analysis and validation by western blot indicated that sALS-CSF induced the over-expression of the pro-apoptotic mitochondrial protein BNIP3L. In the in vitro model, sALS-CSF induced neurotoxicity and elevated ROS, while it lowered the mitochondrial membrane potential in rat spinal cord mitochondria in the in vivo model. Ultra structural alterations were evident in mitochondria of cultured motor neurons exposed to ALS-CSF. These observations indicate the first line evidence that sALS-CSF mediated mitochondrial and lysosomal defects collectively contribute to the pathogenesis underlying sALS. PMID:26646005

  20. Cardiolipin metabolism and the role it plays in heart failure and mitochondrial supercomplex formation.

    Science.gov (United States)

    Mejia, Edgard M; Cole, Laura K; Hatch, Grant M

    2014-01-01

    Cardiolipin is a major membrane phospholipid in the mitochondria and is essential for cellular energy metabolism mediated through mitochondrial oxidative phosphorylation. Recent studies indicate that it plays a diverse role in cellular metabolism. Eukaryotic cardiolipin is synthesized de novo from phosphatidic acid via the cytidine-5'-diphosphate-1,2-diacyl-sn-glycerol pathway and is deacylated to monolysocardiolipin in order for it to be remodelled into the form that is observed in mitochondrial membranes. This resynthesis of deacylated cardiolipin from monolysocardiolipin occurs via the Barth Syndrome gene product tafazzin and acyllysocardiolipin acyltransferase-1, monolysocardiolipin acyltransferase-1 and the alpha subunit of trifunctional protein. Heart failure is a disease condition in which the amount and type of cardiolipin is altered. Several animal models have been generated to study the role of altered cardiolipin in heart failure. In many of these models loss of the tetralinoleoyl-cardiolipin species is observed during the development of the heart failure. In the doxycycline inducible short hairpin RNA tafazzin knock down mouse, loss of tetralinoleoyl-cardiolipin is associated with a mitochondrial bioenergetic disruption. Reduction in mitochondrial supercomplex formation and NADH dehydrogenase activity within these supercomplexes is observed. Modulation of CL fatty acyl composition may serve as a therapeutic strategy for the treatment of several pathologies including cardiac dysfunction.We propose that increasing cardiolipin may improve mitochondrial function and potentially serve as a therapy for diseases which exhibit mitochondrial dysfunction involving reduced cardiolipin. PMID:24801725

  1. Insulin signaling regulates mitochondrial function in pancreatic beta-cells.

    Directory of Open Access Journals (Sweden)

    Siming Liu

    Full Text Available Insulin/IGF-I signaling regulates the metabolism of most mammalian tissues including pancreatic islets. To dissect the mechanisms linking insulin signaling with mitochondrial function, we first identified a mitochondria-tethering complex in beta-cells that included glucokinase (GK, and the pro-apoptotic protein, BAD(S. Mitochondria isolated from beta-cells derived from beta-cell specific insulin receptor knockout (betaIRKO mice exhibited reduced BAD(S, GK and protein kinase A in the complex, and attenuated function. Similar alterations were evident in islets from patients with type 2 diabetes. Decreased mitochondrial GK activity in betaIRKOs could be explained, in part, by reduced expression and altered phosphorylation of BAD(S. The elevated phosphorylation of p70S6K and JNK1 was likely due to compensatory increase in IGF-1 receptor expression. Re-expression of insulin receptors in betaIRKO cells partially restored the stoichiometry of the complex and mitochondrial function. These data indicate that insulin signaling regulates mitochondrial function and have implications for beta-cell dysfunction in type 2 diabetes.

  2. Nitrate-containing beetroot enhances myocyte metabolism and mitochondrial content.

    Science.gov (United States)

    Vaughan, Roger A; Gannon, Nicholas P; Carriker, Colin R

    2016-01-01

    Beetroot ( tián cài) juice consumption is of current interest for improving aerobic performance by acting as a vasodilator and possibly through alterations in skeletal muscle metabolism and physiology. This work explored the effects of a commercially available beetroot supplement on metabolism, gene expression, and mitochondrial content in cultured myocytes. C2C12 myocytes were treated with various concentrations of the beetroot supplement for various durations. Glycolytic metabolism and oxidative metabolism were quantified via measurement of extracellular acidification and oxygen consumption, respectively. Metabolic gene expression was measured using quantitative reverse transcription-polymerase chain reaction, and mitochondrial content was assessed with flow cytometry and confocal microscopy. Cells treated with beetroot exhibited significantly increased oxidative metabolism, concurrently with elevated metabolic gene expression including peroxisome proliferator-activated receptor gamma coactivator-1 alpha, nuclear respiratory factor 1, mitochondrial transcription factor A, and glucose transporter 4, leading to increased mitochondrial biogenesis. Our data show that treatment with a beetroot supplement increases basal oxidative metabolism. Our observations are also among the first to demonstrate that beetroot extract is an inducer of metabolic gene expression and mitochondrial biogenesis. These observations support the need for further investigation into the therapeutic and pharmacological effects of nitrate-containing supplements for health and athletic benefits. PMID:26870674

  3. Dopamine Coupling to Mitochondrial Signaling: Implications for Transplantation.

    Science.gov (United States)

    Stefano, George B; Ramin, Rohina; Kream, Richard M

    2016-01-01

    The persistence of major medical disorders afflicting millions of humans worldwide involves a functional pathophysiological coupling of systemic pro-inflammatory processes and tissue hypoxia. Mechanistically, reciprocal triggering of multiple ischemic/hypoxic and pro-inflammatory events, if not corrected, will promote pathophysiological amplification leading to a deleterious cascade of bio-senescent cellular and molecular signaling pathways that converge to markedly impair mitochondrial energy production. Given the level of energy production and utilization that can vary in and between cells and regionally in the same type of cells found in the body, e.g., dopamine neurons, the metabolic energy regulator, the mitochondrion, assumes a high position in the potential to maintain normal health and develop abnormal activities, resulting in chronic pathologies. The intra-mitochondrial availability of molecular oxygen as the ultimate electron acceptor drives the evolutionarily fashioned chemiosmotic production of ATP as a high-efficiency biological proton pump process. The mechanistic evolutionary bases of diabetes have demonstrated the profound alteration of normative mitochondrial function, notably deregulated respiratory processes. This same phenomenon provides evidence of mitochondrial linkages to neurological disorders, such as Parkinson's disease. To date, and despite considerable research efforts, the practical realization of advanced mitochondrial targeted therapies has not been forthcoming. PMID:26790458

  4. Proteomic Profiling of Mitochondrial Enzymes during Skeletal Muscle Aging

    Directory of Open Access Journals (Sweden)

    Lisa Staunton

    2011-01-01

    Full Text Available Mitochondria are of central importance for energy generation in skeletal muscles. Expression changes or functional alterations in mitochondrial enzymes play a key role during myogenesis, fibre maturation, and various neuromuscular pathologies, as well as natural fibre aging. Mass spectrometry-based proteomics suggests itself as a convenient large-scale and high-throughput approach to catalogue the mitochondrial protein complement and determine global changes during health and disease. This paper gives a brief overview of the relatively new field of mitochondrial proteomics and discusses the findings from recent proteomic surveys of mitochondrial elements in aged skeletal muscles. Changes in the abundance, biochemical activity, subcellular localization, and/or posttranslational modifications in key mitochondrial enzymes might be useful as novel biomarkers of aging. In the long term, this may advance diagnostic procedures, improve the monitoring of disease progression, help in the testing of side effects due to new drug regimes, and enhance our molecular understanding of age-related muscle degeneration.

  5. Ginsenoside Rb1 Protects Neonatal Rat Cardiomyocytes from Hypoxia/Ischemia Induced Apoptosis and Inhibits Activation of the Mitochondrial Apoptotic Pathway

    Directory of Open Access Journals (Sweden)

    Xu Yan

    2014-01-01

    Full Text Available Aim. To investigate the effect of Ginsenoside Rb1 (GS-Rb1 on hypoxia/ischemia (H/I injury in cardiomyocytes in vitro and the mitochondrial apoptotic pathway mediated mechanism. Methods. Neonatal rat cardiomyocytes (NRCMs for the H/I groups were kept in DMEM without glucose and serum, and were placed into a hypoxic jar for 24 h. GS-Rb1 at concentrations from 2.5 to 40 µM was given during hypoxic period for 24 h. NRCMs injury was determined by MTT and lactate dehydrogenase (LDH leakage assay. Cell apoptosis, ROS accumulation, and mitochondrial membrane potential (MMP were assessed by flow cytometry. Cytosolic translocation of mitochondrial cytochrome c and Bcl-2 family proteins were determined by Western blot. Caspase-3 and caspase-9 activities were determined by the assay kit. Results. GS-Rb1 significantly reduced cell death and LDH leakage induced by H/I. It also reduced H/I induced NRCMs apoptosis induced by H/I, in accordance with a minimal reactive oxygen species (ROS burst. Moreover, GS-Rb1 markedly decreased the translocation of cytochrome c from the mitochondria to the cytosol, increased the Bcl-2/ Bax ratio, and preserved mitochondrial transmembrane potential (ΔΨm. Its administration also inhibited activities of caspase-9 and caspase-3. Conclusion. Administration of GS-Rb1 during H/I in vitro is involved in cardioprotection by inhibiting apoptosis, which may be due to inhibition of the mitochondrial apoptotic pathway.

  6. Prenatal stress is a vulnerability factor for altered morphology and biological activity of microglia cells.

    Directory of Open Access Journals (Sweden)

    Joanna eŚlusarczyk

    2015-03-01

    Full Text Available Several lines of evidence suggest that the dysregulation of the immune system is an important factor in the development of depression. Microglia are the resident macrophages of the central nervous system and a key player in innate immunity of the brain. We hypothesized that prenatal stress (an animal model of depression as a priming factor could affect microglial cells and might lead to depressive-like disturbances in adult male rat offspring. We investigated the behavioral changes (sucrose preference test, Porsolt test, the expression of C1q and CD40 mRNA and the level of microglia (Iba1 positive in 3 month old control and prenatally stressed male offspring rats. In addition, we characterized the morphological and biochemical parameters of potentially harmful (NO, iNOS, IL-1β, IL-18, IL-6, TNF-α, CCL2, CXCL12, CCR2, CXCR4 and beneficial (IGF-1, BDNF phenotypes in cultures of microglia obtained from the cortices of 1-2 days old control and prenatally stressed pups. The adult prenatally stressed rats showed behavioral (anhedonic- and depression-like disturbances, enhanced expression of microglial activation markers and an increased number of Iba1-immunopositive cells in the hippocampus and frontal cortex. The morphology of glia was altered in cultures from prenatally stressed rats, as demonstrated by immunofluorescence microscopy. Moreover, in these cultures, we observed enhanced expression of CD40 and MHC II and release of pro-inflammatory cytokines, including IL-1β, IL-18, TNF-α and IL-6. Prenatal stress significantly up-regulated levels of the chemokines CCL2, CXCL12 and altered expression of their receptors, CCR2 and CXCR4 while IGF-1 production was suppressed in cultures of microglia from prenatally stressed rats.Our results suggest that prenatal stress may lead to excessive microglia activation and contribute to the behavioral changes observed in depression in adulthood.

  7. Prenatal stress is a vulnerability factor for altered morphology and biological activity of microglia cells.

    Science.gov (United States)

    Ślusarczyk, Joanna; Trojan, Ewa; Głombik, Katarzyna; Budziszewska, Bogusława; Kubera, Marta; Lasoń, Władysław; Popiołek-Barczyk, Katarzyna; Mika, Joanna; Wędzony, Krzysztof; Basta-Kaim, Agnieszka

    2015-01-01

    Several lines of evidence suggest that the dysregulation of the immune system is an important factor in the development of depression. Microglia are the resident macrophages of the central nervous system and a key player in innate immunity of the brain. We hypothesized that prenatal stress (an animal model of depression) as a priming factor could affect microglial cells and might lead to depressive-like disturbances in adult male rat offspring. We investigated the behavioral changes (sucrose preference test, Porsolt test), the expression of C1q and CD40 mRNA and the level of microglia (Iba1 positive) in 3-month-old control and prenatally stressed male offspring rats. In addition, we characterized the morphological and biochemical parameters of potentially harmful (NO, iNOS, IL-1β, IL-18, IL-6, TNF-α, CCL2, CXCL12, CCR2, CXCR4) and beneficial (insulin-like growth factor-1 (IGF-1), brain derived neurotrophic factor (BDNF)) phenotypes in cultures of microglia obtained from the cortices of 1-2 days old control and prenatally stressed pups. The adult prenatally stressed rats showed behavioral (anhedonic- and depression-like) disturbances, enhanced expression of microglial activation markers and an increased number of Iba1-immunopositive cells in the hippocampus and frontal cortex. The morphology of glia was altered in cultures from prenatally stressed rats, as demonstrated by immunofluorescence microscopy. Moreover, in these cultures, we observed enhanced expression of CD40 and MHC II and release of pro-inflammatory cytokines, including IL-1β, IL-18, TNF-α and IL-6. Prenatal stress significantly up-regulated levels of the chemokines CCL2, CXCL12 and altered expression of their receptors, CCR2 and CXCR4 while IGF-1 production was suppressed in cultures of microglia from prenatally stressed rats. Our results suggest that prenatal stress may lead to excessive microglia activation and contribute to the behavioral changes observed in depression in adulthood. PMID

  8. Altered Insula Activity during Visceral Interoception in Weight-Restored Patients with Anorexia Nervosa.

    Science.gov (United States)

    Kerr, Kara L; Moseman, Scott E; Avery, Jason A; Bodurka, Jerzy; Zucker, Nancy L; Simmons, W Kyle

    2016-01-01

    Anorexia nervosa (AN) is a devastating psychiatric illness that is associated with significant morbidity and mortality. Aberrant visceral interoceptive processing within the insula has been hypothesized to be an important mechanism in AN's pathophysiology due to the theoretical link between interoception and emotional experience. We therefore utilized functional magnetic resonance imaging (fMRI) to examine whether altered insula functioning underlies visceral interoception in AN. Fifteen females with restricting-type AN and 15 healthy control females underwent fMRI while performing an interoceptive attention task during which they focused on sensations in their heart, stomach, and bladder. Participants also performed an anxious rumination task while in the scanner. AN participants were weight-restored and free of psychotropic medications. Two distinct regions of the insula-anterior insula and dorsal mid-insula-exhibited a significant (p<0.05) interaction between group and interoceptive modality. The post hoc analyses revealed that in the dorsal mid-insula the interaction was driven by group differences during stomach interoception (p=0.002, Bonferroni corrected), whereas in the anterior insula the interaction was driven by group differences during heart interoception (p=0.03, Bonferroni corrected). In addition, individuals with AN displayed increased activation during anxious rumination in the dorsal mid-insula, and activation in this region during stomach interoception was correlated with measures of anxiety and psychopathology. This relationship between altered visceral interoception and clinical symptoms in AN suggests an important mechanism for the disorder. Additional research is needed to examine whether interventions targeting visceral interoception may increase the efficacy of treatments for AN. PMID:26084229

  9. Spaceflight alters expression of microRNA during T-cell activation.