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Sample records for targets mitochondria alters

  1. The Pseudomonas syringae type III effector HopG1 targets mitochondria, alters plant development, and suppresses plant innate immunity

    Science.gov (United States)

    Block, Anna; Guo, Ming; Li, Guangyong; Elowsky, Christian; Clemente, Thomas E.; Alfano, James R.

    2009-01-01

    Summary The bacterial plant pathogen Pseudomonas syringae uses a type III protein secretion system to inject type III effectors into plant cells. Primary targets of these effectors appear to be effector-triggered immunity (ETI) and pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI). The type III effector HopG1 is a suppressor of ETI that is broadly conserved in bacterial plant pathogens. Here we show that HopG1 from P. syringae pv. tomato DC3000 also suppresses PTI. Interestingly, HopG1 localizes to plant mitochondria, suggesting that its suppression of innate immunity may be linked to a perturbation of mitochondrial function. While HopG1 possesses no obvious mitochondrial signal peptide, its N-terminal two-thirds was sufficient for mitochondrial localization. A HopG1-GFP fusion lacking HopG1’s N-terminal 13 amino acids was not localized to the mitochondria reflecting the importance of the N-terminus for targeting. Constitutive expression of HopG1 in Arabidopsis thaliana, Nicotiana tabacum (tobacco) and Lycopersicon esculentum (tomato) dramatically alters plant development resulting in dwarfism, increased branching and infertility. Constitutive expression of HopG1 in planta leads to reduced respiration rates and an increased basal level of reactive oxygen species. These findings suggest that HopG1’s target is mitochondrial and that effector/target interaction promotes disease by disrupting mitochondrial functions. PMID:19863557

  2. Aging and Spaceflight: Catalase Targeted to Mitochondria Alters Skeletal Structure and Responses to Musculoskeletal Disuse

    Science.gov (United States)

    Globus, Ruth K.; Tahimic, Candice; Schreurs, Ann-Sofie

    2018-01-01

    Microgravity and ionizing radiation in the spaceflight environment pose multiple challenges to homeostasis and may contribute to cellular stress. Effects may include increased generation of reactive oxygen species (ROS), DNA damage and repair error, cell cycle arrest, cell senescence or death. Our central hypothesis is that prolonged exposure to the spaceflight environment leads to excess production of ROS and oxidative damage, culminating in accelerated tissue degeneration which resembles aging. The main goal of this project is to determine the importance of cellular redox defense for physiological adaptations and tissue degeneration in the space environment. To accomplish this, we will use both wildtype (WT) mice and a well-established, genetically-engineered animal model (mCAT mice) which displays extended lifespan (Schriner et al. 2005). The animal model selected to test these ideas is engineered to quench ROS in mitochondria by targeted over-expression of the human catalase gene to the mitochondrial matrix. We showed previously that mCAT mice express the catalase transgene in skeletal tissues, bone forming osteoblasts, and bone resorbing osteoclasts. In addition, mCAT mice also display increased catalase activity in bone. Our findings revealed that exposure of adult, male, C57Bl/6J mice to simulated spaceflight (hindlimb unloading and gamma radiation) led to an increase in markers of oxidative damage (malondialdehyde, 4-hydroxynonenol) in skeletal tissue of WT mice but not mCAT mice. To extend our hypothesis to other, spaceflight-relevant tissues, we are performing a ground-based study simulating 30 days of spaceflight by hindlimb unloading to determine potential protective effects of mitochondrial catalase activity on aging of multiple tissues (cardiovascular, nervous and skeletal).

  3. Exogenous ether lipids predominantly target mitochondria

    DEFF Research Database (Denmark)

    Kuerschner, Lars; Richter, Doris; Hannibal-Bach, Hans Kristian

    2012-01-01

    Ether lipids are ubiquitous constituents of cellular membranes with no discrete cell biological function assigned yet. Using fluorescent polyene-ether lipids we analyzed their intracellular distribution in living cells by microscopy. Mitochondria and the endoplasmic reticulum accumulated high......, accumulated to mitochondria and induced morphological changes and cellular apoptosis. These data indicate that edelfosine could exert its pro-apoptotic power by targeting and damaging mitochondria and thereby inducing cellular apoptosis. In general, this study implies an important role of mitochondria...

  4. Bacterial infection increases risk of carcinogenesis by targeting mitochondria

    DEFF Research Database (Denmark)

    Strickertsson, Jesper A.B.; Desler, Claus; Rasmussen, Lene Juel

    2017-01-01

    pathways, and compares the impact of the bacterial alteration of mitochondrial function to that of cancer. Bacterial virulence factors have been demonstrated to induce mutations of mitochondrial DNA (mtDNA) and to modulate DNA repair pathways of the mitochondria. Furthermore, virulence factors can induce...... or impair the intrinsic apoptotic pathway. The effect of bacterial targeting of mitochondria is analogous to behavior of mitochondria in a wide array of tumours, and this strongly suggests that mitochondrial targeting of bacteria is a risk factor for carcinogenesis....

  5. Exogenous ether lipids predominantly target mitochondria.

    Directory of Open Access Journals (Sweden)

    Lars Kuerschner

    Full Text Available Ether lipids are ubiquitous constituents of cellular membranes with no discrete cell biological function assigned yet. Using fluorescent polyene-ether lipids we analyzed their intracellular distribution in living cells by microscopy. Mitochondria and the endoplasmic reticulum accumulated high amounts of ether-phosphatidylcholine and ether-phosphatidylethanolamine. Both lipids were specifically labeled using the corresponding lyso-ether lipids, which we established as supreme precursors for lipid tagging. Polyfosine, a fluorescent analogue of the anti-neoplastic ether lipid edelfosine, accumulated to mitochondria and induced morphological changes and cellular apoptosis. These data indicate that edelfosine could exert its pro-apoptotic power by targeting and damaging mitochondria and thereby inducing cellular apoptosis. In general, this study implies an important role of mitochondria in ether lipid metabolism and intracellular ether lipid trafficking.

  6. Rejuvenating cellular respiration for optimizing respiratory function: targeting mitochondria.

    Science.gov (United States)

    Agrawal, Anurag; Mabalirajan, Ulaganathan

    2016-01-15

    Altered bioenergetics with increased mitochondrial reactive oxygen species production and degradation of epithelial function are key aspects of pathogenesis in asthma and chronic obstructive pulmonary disease (COPD). This motif is not unique to obstructive airway disease, reported in related airway diseases such as bronchopulmonary dysplasia and parenchymal diseases such as pulmonary fibrosis. Similarly, mitochondrial dysfunction in vascular endothelium or skeletal muscles contributes to the development of pulmonary hypertension and systemic manifestations of lung disease. In experimental models of COPD or asthma, the use of mitochondria-targeted antioxidants, such as MitoQ, has substantially improved mitochondrial health and restored respiratory function. Modulation of noncoding RNA or protein regulators of mitochondrial biogenesis, dynamics, or degradation has been found to be effective in models of fibrosis, emphysema, asthma, and pulmonary hypertension. Transfer of healthy mitochondria to epithelial cells has been associated with remarkable therapeutic efficacy in models of acute lung injury and asthma. Together, these form a 3R model--repair, reprogramming, and replacement--for mitochondria-targeted therapies in lung disease. This review highlights the key role of mitochondrial function in lung health and disease, with a focus on asthma and COPD, and provides an overview of mitochondria-targeted strategies for rejuvenating cellular respiration and optimizing respiratory function in lung diseases. Copyright © 2016 the American Physiological Society.

  7. Targeting Mitochondria to Counteract Age-Related Cellular Dysfunction

    Directory of Open Access Journals (Sweden)

    Corina T. Madreiter-Sokolowski

    2018-03-01

    Full Text Available Senescence is related to the loss of cellular homeostasis and functions, which leads to a progressive decline in physiological ability and to aging-associated diseases. Since mitochondria are essential to energy supply, cell differentiation, cell cycle control, intracellular signaling and Ca2+ sequestration, fine-tuning mitochondrial activity appropriately, is a tightrope walk during aging. For instance, the mitochondrial oxidative phosphorylation (OXPHOS ensures a supply of adenosine triphosphate (ATP, but is also the main source of potentially harmful levels of reactive oxygen species (ROS. Moreover, mitochondrial function is strongly linked to mitochondrial Ca2+ homeostasis and mitochondrial shape, which undergo various alterations during aging. Since mitochondria play such a critical role in an organism’s process of aging, they also offer promising targets for manipulation of senescent cellular functions. Accordingly, interventions delaying the onset of age-associated disorders involve the manipulation of mitochondrial function, including caloric restriction (CR or exercise, as well as drugs, such as metformin, aspirin, and polyphenols. In this review, we discuss mitochondria’s role in and impact on cellular aging and their potential to serve as a target for therapeutic interventions against age-related cellular dysfunction.

  8. Mitochondria-targeted nutraceuticals in sports medicine: a new perspective.

    Science.gov (United States)

    Ostojic, Sergej M

    2017-01-01

    Since mitochondria have been recognized as the cells' key organelles involved in the energy utilization during exercise, targeting the organelle with specifically designed compounds (mitochondria-targeted nutraceuticals, MTNs) may have a great promise in the prevention and treatment of heavy exercise-related mitochondrial dysfunction. In vitro studies suggested that MTNs have antioxidant effects at the molecular level, and might boost mitochondrial biogenesis and organelle bioenergetics, with both processes are known to positively affect exercise performance and recovery. However, while there are a number of different MTNs evaluated for a potential benefit as a therapy for mitochondria-related diseases and conditions, only few human studies evaluated the possible impact of novel MTNs in the field of sports medicine. This mini review summarizes recent research findings regarding the efficacy of different mitochondria-targeted nutritional agents, emphasizing their roles in sports medicine.

  9. Mitochondria: Target organelles for estrogen action

    Directory of Open Access Journals (Sweden)

    Małgorzata Chmielewska

    2017-06-01

    Full Text Available Estrogens belong to a group of sex hormones, which have been shown to act in multidirectional way. Estrogenic effects are mediated by two types of intracellular receptors: estrogen receptor 1 (ESR1 and estrogen receptor 2 (ESR2. There are two basic mechanisms of estrogen action: 1 classical-genomic, in which the ligand-receptor complex acts as a transcriptional factor and 2 a nongenomic one, which is still not fully understood, but has been seen to lead to distinct biological effects, depending on tissue and ligand type. It is postulated that nongenomic effects may be associated with membrane signaling and the presence of classical nuclear receptors within the cell membrane. Estrogens act in a multidirectional way also within cell organelles. It is assumed that there is a mechanism which manages the migration of ESR into the mitochondrial membrane, wherein the exogenous estrogen affect the morphology of mitochondria. Estrogen, through its receptor, can directly modulate mitochondrial gene expression. Moreover, by regulating the level of reactive oxygen species, estrogens affect the biology of mitochondria. The considerations presented in this paper indicate the pleiotropic effects of estrogens, which represent a multidirectional pathway of signal transduction.

  10. Mitochondria and Mitochondrial ROS in Cancer: Novel Targets for Anticancer Therapy.

    Science.gov (United States)

    Yang, Yuhui; Karakhanova, Svetlana; Hartwig, Werner; D'Haese, Jan G; Philippov, Pavel P; Werner, Jens; Bazhin, Alexandr V

    2016-12-01

    Mitochondria are indispensable for energy metabolism, apoptosis regulation, and cell signaling. Mitochondria in malignant cells differ structurally and functionally from those in normal cells and participate actively in metabolic reprogramming. Mitochondria in cancer cells are characterized by reactive oxygen species (ROS) overproduction, which promotes cancer development by inducing genomic instability, modifying gene expression, and participating in signaling pathways. Mitochondrial and nuclear DNA mutations caused by oxidative damage that impair the oxidative phosphorylation process will result in further mitochondrial ROS production, completing the "vicious cycle" between mitochondria, ROS, genomic instability, and cancer development. The multiple essential roles of mitochondria have been utilized for designing novel mitochondria-targeted anticancer agents. Selective drug delivery to mitochondria helps to increase specificity and reduce toxicity of these agents. In order to reduce mitochondrial ROS production, mitochondria-targeted antioxidants can specifically accumulate in mitochondria by affiliating to a lipophilic penetrating cation and prevent mitochondria from oxidative damage. In consistence with the oncogenic role of ROS, mitochondria-targeted antioxidants are found to be effective in cancer prevention and anticancer therapy. A better understanding of the role played by mitochondria in cancer development will help to reveal more therapeutic targets, and will help to increase the activity and selectivity of mitochondria-targeted anticancer drugs. In this review we summarized the impact of mitochondria on cancer and gave summary about the possibilities to target mitochondria for anticancer therapies. J. Cell. Physiol. 231: 2570-2581, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  11. Mitochondria: 3-bromopyruvate vs. mitochondria? A small molecule that attacks tumors by targeting their bioenergetic diversity.

    Science.gov (United States)

    Galina, Antonio

    2014-09-01

    Enhanced glycolysis, the classic bioenergetic phenotype of cancer cells was described by Otto Warburg approximately 90 years ago. However, the Warburg hypothesis does not necessarily imply mitochondrial dysfunction. The alkyl-halogen, 3-bromopyruvate (3BP), would not be expected to have selective targets for cancer therapy due to its high potential reactivity toward many SH side groups. Contrary to predictions, 3BP interferes with glycolysis and oxidative phosphorylation in cancer cells without side effects in normal tissues. The mitochondrial hexokinase II has been claimed as the main target. This "Organelle in focus" article presents a historical view of the use of 3BP in biochemistry and its effects on ATP-producing pathways of cancer cells. I will discuss how the alkylated enzymes contribute to the cooperative collapse of mitochondria and apoptosis. Perspectives for targeting 3BP to bioenergetics enzymes for cancer treatment will be considered. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Molecular Strategies for Targeting Antioxidants to Mitochondria: Therapeutic Implications

    Science.gov (United States)

    2015-01-01

    Abstract Mitochondrial function and specifically its implication in cellular redox/oxidative balance is fundamental in controlling the life and death of cells, and has been implicated in a wide range of human pathologies. In this context, mitochondrial therapeutics, particularly those involving mitochondria-targeted antioxidants, have attracted increasing interest as potentially effective therapies for several human diseases. For the past 10 years, great progress has been made in the development and functional testing of molecules that specifically target mitochondria, and there has been special focus on compounds with antioxidant properties. In this review, we will discuss several such strategies, including molecules conjugated with lipophilic cations (e.g., triphenylphosphonium) or rhodamine, conjugates of plant alkaloids, amino-acid- and peptide-based compounds, and liposomes. This area has several major challenges that need to be confronted. Apart from antioxidants and other redox active molecules, current research aims at developing compounds that are capable of modulating other mitochondria-controlled processes, such as apoptosis and autophagy. Multiple chemically different molecular strategies have been developed as delivery tools that offer broad opportunities for mitochondrial manipulation. Additional studies, and particularly in vivo approaches under physiologically relevant conditions, are necessary to confirm the clinical usefulness of these molecules. Antioxid. Redox Signal. 22, 686–729. PMID:25546574

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

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    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.

  14. Mitochondria As the Target for the Modulatory Effect of Curcumin in Oxaliplatin-induced Toxicity in Isolated Rat Liver Mitochondria.

    Science.gov (United States)

    Waseem, Mohammad; Parvez, Suhel; Tabassum, Heena

    2017-01-01

    To explore hepatoprotective action of curcumin (CMN, a bioflavonoid) on oxaliplatin (Oxa)-triggered mitochondrial oxidative stress and respiratory chain complexes in liver of rats. Oxa is a ubiquitously utilized platinum-based chemotherapeutic agent commonly used for the treatment of colorectal cancer. Mitochondria have recently emerged as targets for anticancer drugs in several kinds of toxicity including hepatotoxicity that can lead to neoplastic disease. There is a dearth of evidence involving the role of mitochondria in mediating Oxa-evoked hepatotoxicity and its underlying mechanism is still debatable. The study was performed in mitochondria isolated from liver of Wistar rats. Oxa (200 μg/mL) and CMN (5 μmol) were incubated under in vitro conditions. Oxa evoked a significant increase in the membrane lipid peroxidation (LPO) levels, protein carbonyl (PC) contents, decrease in reduced glutathione (GSH) and nonprotein thiol (NP-SH) levels. Oxa also caused a marked decline in the activities of enzymatic antioxidants and respiratory chain enzymes (I, II, III and V) in liver mitochondria. CMN pre-treatment significantly prevented the activities of enzymatic antioxidants and mitochondrial respiratory chain enzymes. CMN also restored the LPO and PC contents, GSH and NP-SH levels in liver mitochondria. CMN intake might be effective in regulation of Oxa-evoked mitotoxicity during chemotherapy. Moreover, it is included in the armamentarium for anticancer agent-induced oxidative stress. Copyright © 2017 IMSS. Published by Elsevier Inc. All rights reserved.

  15. Mitochondria-targeted vitamin E analogs inhibit breast cancer cell energy metabolism and promote cell death

    International Nuclear Information System (INIS)

    Cheng, Gang; Zielonka, Jacek; McAllister, Donna M; Mackinnon, A Craig Jr; Joseph, Joy; Dwinell, Michael B; Kalyanaraman, Balaraman

    2013-01-01

    Recent research has revealed that targeting mitochondrial bioenergetic metabolism is a promising chemotherapeutic strategy. Key to successful implementation of this chemotherapeutic strategy is the use of new and improved mitochondria-targeted cationic agents that selectively inhibit energy metabolism in breast cancer cells, while exerting little or no long-term cytotoxic effect in normal cells. In this study, we investigated the cytotoxicity and alterations in bioenergetic metabolism induced by mitochondria-targeted vitamin E analog (Mito-chromanol, Mito-ChM) and its acetylated ester analog (Mito-ChMAc). Assays of cell death, colony formation, mitochondrial bioenergetic function, intracellular ATP levels, intracellular and tissue concentrations of tested compounds, and in vivo tumor growth were performed. Both Mito-ChM and Mito-ChMAc selectively depleted intracellular ATP and caused prolonged inhibition of ATP-linked oxygen consumption rate in breast cancer cells, but not in non-cancerous cells. These effects were significantly augmented by inhibition of glycolysis. Mito-ChM and Mito-ChMAc exhibited anti-proliferative effects and cytotoxicity in several breast cancer cells with different genetic background. Furthermore, Mito-ChM selectively accumulated in tumor tissue and inhibited tumor growth in a xenograft model of human breast cancer. We conclude that mitochondria-targeted small molecular weight chromanols exhibit selective anti-proliferative effects and cytotoxicity in multiple breast cancer cells, and that esterification of the hydroxyl group in mito-chromanols is not a critical requirement for its anti-proliferative and cytotoxic effect

  16. Quantitative Proteomics Analysis Identifies Mitochondria as Therapeutic Targets of Multidrug-Resistance in Ovarian Cancer

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    Chen, Xiulan; Wei, Shasha; Ma, Ying; Lu, Jie; Niu, Gang; Xue, Yanhong; Chen, Xiaoyuan; Yang, Fuquan

    2014-01-01

    Doxorubicin is a widely used chemotherapeutic agent for the treatment of a variety of solid tumors. However, resistance to this anticancer drug is a major obstacle to the effective treatment of tumors. As mitochondria play important roles in cell life and death, we anticipate that mitochondria may be related to drug resistance. Here, stable isotope labeling by amino acids in cell culture (SILAC)-based quantitative proteomic strategy was applied to compare mitochondrial protein expression in doxorubicin sensitive OVCAR8 cells and its doxorubicin-resistant variant NCI_ADR/RES cells. A total of 2085 proteins were quantified, of which 122 proteins displayed significant changes in the NCI_ADR/RES cells. These proteins participated in a variety of cell processes including cell apoptosis, substance metabolism, transport, detoxification and drug metabolism. Then qRT-PCR and western blot were applied to validate the differentially expressed proteins quantified by SILAC. Further functional studies with RNAi demonstrated TOP1MT, a mitochondrial protein participated in DNA repair, was involved in doxorubicin resistance in NCI_ADR/RES cells. Besides the proteomic study, electron microscopy and fluorescence analysis also observed that mitochondrial morphology and localization were greatly altered in NCI_ADR/RES cells. Mitochondrial membrane potential was also decreased in NCI_ADR/RES cells. All these results indicate that mitochondrial function is impaired in doxorubicin-resistant cells and mitochondria play an important role in doxorubicin resistance. This research provides some new information about doxorubicin resistance, indicating that mitochondria could be therapeutic targets of doxorubicin resistance in ovarian cancer cells. PMID:25285166

  17. Targeting mitochondria in cancer cells using gold nanoparticle-enhanced radiotherapy: A Monte Carlo study

    Energy Technology Data Exchange (ETDEWEB)

    Kirkby, Charles, E-mail: charles.kirkby@albertahealthservices.ca; Ghasroddashti, Esmaeel [Department of Medical Physics, Jack Ady Cancer Centre, Lethbridge, Alberta T1J 1W5 (Canada); Department of Physics and Astronomy, University of Calgary, Calgary, Alberta T2N 1N4 (Canada); Department of Oncology, University of Calgary, Calgary, Alberta T2N 4N2 (Canada)

    2015-02-15

    Purpose: Radiation damage to mitochondria has been shown to alter cellular processes and even lead to apoptosis. Gold nanoparticles (AuNPs) may be used to enhance these effects in scenarios where they collect on the outer membranes of mitochondria. A Monte Carlo (MC) approach is used to estimate mitochondrial dose enhancement under a variety of conditions. Methods: The PENELOPE MC code was used to generate dose distributions resulting from photons striking a 13 nm diameter AuNP with various thicknesses of water-equivalent coatings. Similar dose distributions were generated with the AuNP replaced by water so as to estimate the gain in dose on a microscopic scale due to the presence of AuNPs within an irradiated volume. Models of mitochondria with AuNPs affixed to their outer membrane were then generated—considering variation in mitochondrial size and shape, number of affixed AuNPs, and AuNP coating thickness—and exposed (in a dose calculation sense) to source spectra ranging from 6 MV to 90 kVp. Subsequently dose enhancement ratios (DERs), or the dose with the AuNPs present to that for no AuNPs, for the entire mitochondrion and its components were tallied under these scenarios. Results: For a representative case of a 1000 nm diameter mitochondrion affixed with 565 AuNPs, each with a 13 nm thick coating, the mean DER over the whole organelle ranged from roughly 1.1 to 1.6 for the kilovoltage sources, but was generally less than 1.01 for the megavoltage sources. The outer membrane DERs remained less than 1.01 for the megavoltage sources, but rose to 2.3 for 90 kVp. The voxel maximum DER values were as high as 8.2 for the 90 kVp source and increased further when the particles clustered together. The DER exhibited dependence on the mitochondrion dimensions, number of AuNPs, and the AuNP coating thickness. Conclusions: Substantial dose enhancement directly to the mitochondria can be achieved under the conditions modeled. If the mitochondrion dose can be directly

  18. Nanopreparations for mitochondria targeting drug delivery system: Current strategies and future prospective

    Directory of Open Access Journals (Sweden)

    Zhenjie Wang

    2017-11-01

    Full Text Available Mitochondria are a novel and promising therapeutic target for diagnosis, treatment and prevention of a lot of human diseases such as cancer, metabolic diseases and neurodegenerative disease. Owing to the mitochondrial special bilayer structure and highly negative potential nature, therapeutic molecules have multiple difficulties in reaching mitochondria. To overcome multiple barriers for targeting mitochondria, the researchers developed various pharmaceutical preparations such as liposomes, polymeric nanoparticles and inorganic nanoparticles modified by mitochondriotropic moieties like dequalinium (DQA, triphenylphosphonium (TPP, mitochondrial penetrating peptides (MPPs and mitochondrial protein import machinery that allow specific targeting. The targeted formulations exhibited enhanced pharmacological effect and better therapeutic effect than their untargeted counterpart both in vitro and in vivo. Nanocarriers may be used for bio-therapeutic delivery into specific mitochondria that possess a great potential treatment of mitochondria related diseases.

  19. Mitochondria as Pharmacological Targets: The Discovery of Novel ...

    African Journals Online (AJOL)

    When food intake chronically exceeds the body's energy need, an efficient metabolism results in the storage of the excess energy as fat. Mitochondria are the main centre for energy production in eukaryotic cells. Mitochondrial proton cycling is responsible for a significant proportion of basal or standard metabolic rate, ...

  20. Mitochondria: An intriguing target for killing tumour-initiating cells

    Czech Academy of Sciences Publication Activity Database

    Yan, B.; Dong, L.; Neužil, Jiří

    2016-01-01

    Roč. 26, JAN 2016 (2016), s. 86-93 ISSN 1567-7249 R&D Projects: GA MŠk(CZ) ED1.1.00/02.0109 Institutional support: RVO:86652036 Keywords : Tumour-initiating cells * ALPHA-TOCOPHERYL SUCCINATE * Therapeutic resistance * Mitochondria Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.704, year: 2016

  1. PEGylated anticancer-carbon nanotubes complex targeting mitochondria of lung cancer cells

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    Kim, Sang-Woo; Lee, Yeon Kyung; Lee, Jong Yeon; Hong, Jeong Hee; Khang, Dongwoo

    2017-11-01

    Although activating apoptosis in cancer cells by targeting the mitochondria is an effective strategy for cancer therapy, insufficient targeting of the mitochondria in cancer cells restricts the availability in clinical treatment. Here, we report on a polyethylene glycol-coated carbon nanotube (CNT)-ABT737 nanodrug that improves the mitochondrial targeting of lung cancer cells. The polyethylene glycol-coated CNT-ABT737 nanodrug internalized into the early endosomes via macropinocytosis and clathrin-mediated endocytosis in advance of early endosomal escape and delivered into the mitochondria. Cytosol release of the nanodrug led to apoptosis of lung cancer cells by abruption of the mitochondrial membrane potential, inducing Bcl-2-mediated apoptosis and generating intracellular reactive oxygen species. As such, this study provides an effective strategy for increasing the anti-lung cancer efficacy by increasing mitochondria accumulation rate of cytosol released anticancer nanodrugs.

  2. A Powerful Mitochondria-Targeted Iron Chelator Affords High Photoprotection against Solar Ultraviolet A Radiation

    OpenAIRE

    Reelfs, Olivier; Abbate, Vincenzo; Hider, Robert C.; Pourzand, Charareh

    2016-01-01

    Mitochondria are the principal destination for labile iron, making these organelles particularly susceptible to oxidative damage on exposure to ultraviolet A (UVA, 320?400 nm), the oxidizing component of sunlight. The labile iron-mediated oxidative damage caused by UVA to mitochondria leads to necrotic cell death via adenosine triphosphate depletion. Therefore, targeted removal of mitochondrial labile iron via highly specific tools from these organelles may be an effective approach to protect...

  3. Modulation of ROS levels in fibroblasts by altering mitochondria regulates the process of wound healing.

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    Janda, Jaroslav; Nfonsam, Valentine; Calienes, Fernanda; Sligh, James E; Jandova, Jana

    2016-05-01

    Mitochondria are the major source of reactive oxygen species (ROS) in fibroblasts which are thought to be crucial regulators of wound healing with a potential to affect the expression of nuclear genes involved in this process. ROS generated by mitochondria are involved in all stages of tissue repair process but the regulation of ROS-generating system in fibroblasts still remains poorly understood. The purpose of this study was to better understand molecular mechanisms of how the regulation of ROS levels generated by mitochondria may influence the process of wound repair. Cybrid model system of mtDNA variations was used to study the functional consequences of altered ROS levels on wound healing responses in a uniform nuclear background of cultured ρ(0) fibroblasts. Mitochondrial ROS in cybrids were modulated by antioxidants that quench ROS to examine their ability to close the wound. Real-time PCR arrays were used to investigate whether ROS generated by specific mtDNA variants have the ability to alter expression of some key nuclear-encoded genes central to the wound healing response and oxidative stress. Our data suggest levels of mitochondrial ROS affect expression of some nuclear encoded genes central to wound healing response and oxidative stress and modulation of mitochondrial ROS by antioxidants positively affects in vitro process of wound closure. Thus, regulation of mitochondrial ROS-generating system in fibroblasts can be used as effective natural redox-based strategy to help treat non-healing wounds.

  4. Dual peptide conjugation strategy for improved cellular uptake and mitochondria targeting.

    Science.gov (United States)

    Lin, Ran; Zhang, Pengcheng; Cheetham, Andrew G; Walston, Jeremy; Abadir, Peter; Cui, Honggang

    2015-01-21

    Mitochondria are critical regulators of cellular function and survival. Delivery of therapeutic and diagnostic agents into mitochondria is a challenging task in modern pharmacology because the molecule to be delivered needs to first overcome the cell membrane barrier and then be able to actively target the intracellular organelle. Current strategy of conjugating either a cell penetrating peptide (CPP) or a subcellular targeting sequence to the molecule of interest only has limited success. We report here a dual peptide conjugation strategy to achieve effective delivery of a non-membrane-penetrating dye 5-carboxyfluorescein (5-FAM) into mitochondria through the incorporation of both a mitochondrial targeting sequence (MTS) and a CPP into one conjugated molecule. Notably, circular dichroism studies reveal that the combined use of α-helix and PPII-like secondary structures has an unexpected, synergistic contribution to the internalization of the conjugate. Our results suggest that although the use of positively charged MTS peptide allows for improved targeting of mitochondria, with MTS alone it showed poor cellular uptake. With further covalent linkage of the MTS-5-FAM conjugate to a CPP sequence (R8), the dually conjugated molecule was found to show both improved cellular uptake and effective mitochondria targeting. We believe these results offer important insight into the rational design of peptide conjugates for intracellular delivery.

  5. Melatonin as a mitochondria-targeted antioxidant: one of evolution's best ideas.

    Science.gov (United States)

    Reiter, Russel J; Rosales-Corral, Sergio; Tan, Dun Xian; Jou, Mei Jie; Galano, Annia; Xu, Bing

    2017-11-01

    Melatonin is an ancient antioxidant. After its initial development in bacteria, it has been retained throughout evolution such that it may be or may have been present in every species that have existed. Even though it has been maintained throughout evolution during the diversification of species, melatonin's chemical structure has never changed; thus, the melatonin present in currently living humans is identical to that present in cyanobacteria that have existed on Earth for billions of years. Melatonin in the systemic circulation of mammals quickly disappears from the blood presumably due to its uptake by cells, particularly when they are under high oxidative stress conditions. The measurement of the subcellular distribution of melatonin has shown that the concentration of this indole in the mitochondria greatly exceeds that in the blood. Melatonin presumably enters mitochondria through oligopeptide transporters, PEPT1, and PEPT2. Thus, melatonin is specifically targeted to the mitochondria where it seems to function as an apex antioxidant. In addition to being taken up from the circulation, melatonin may be produced in the mitochondria as well. During evolution, mitochondria likely originated when melatonin-forming bacteria were engulfed as food by ancestral prokaryotes. Over time, engulfed bacteria evolved into mitochondria; this is known as the endosymbiotic theory of the origin of mitochondria. When they did so, the mitochondria retained the ability to synthesize melatonin. Thus, melatonin is not only taken up by mitochondria but these organelles, in addition to many other functions, also probably produce melatonin as well. Melatonin's high concentrations and multiple actions as an antioxidant provide potent antioxidant protection to these organelles which are exposed to abundant free radicals.

  6. Electronic microscopy evidence for mitochondria as targets for Cd/Se/Te-based quantum dot 705 toxicity in vivo

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    Chia-Hua Lin

    2012-07-01

    Full Text Available The safety of quantum dots (QDs 705 was evaluated in this study. Mice were treated with QD705 (intravenous at a single dose of (40 pmol for 4, 12, 16, and 24 weeks. Effects of QD705 on kidneys were examined. While there was a lack of histopathology, reduction in renal functions was detected at 16 weeks. Electron microscopic examination revealed alterations in proximal convoluted tubule (PCT cell mitochondria at even much earlier time, including disorientation and reduction of mitochondrial number (early change, mitochondrial swelling, and later compensatory mitochondrial hypertrophy (enlargement mitochondria: giant mitochondria with hyperplastic inner cristae as well as mitochondrial hyperplasia (increase in mitochondrial biogenesis and numbers were observed. Such changes probably represent compensatory attempts of the mitochondria for functional loss or reduction of mitochondria in QD705 treated animals. Moreover, degeneration of mitochondria (myelin-figure and cytoplasmic membranous body formation and degradation of cytoplasmic materials (isolated cytoplasmic pockets of degenerated materials and focal cytoplasmic degradation also occurred in later time points (16–24 weeks. Such mitochondrial changes were not identical with those induced by pure cadmium. Taken together, we suggest that mitochondria appeared to be the target of QD705 toxicity and specific mitochondrial markers may be useful parameters for toxicity assessments of QDs or other metal-based nanomaterials.

  7. Mitochondria Targeting with Luminescent Rhenium(I) Complexes.

    Science.gov (United States)

    Skiba, Joanna; Bernaś, Tytus; Trzybiński, Damian; Woźniak, Krzysztof; Ferraro, Giarita; Marasco, Daniela; Merlino, Antonello; Shafikov, Marsel Z; Czerwieniec, Rafał; Kowalski, Konrad

    2017-05-15

    Two new neutral fac -[Re(CO)₃(phen)L] compounds ( 1 , 2 ), with phen = 1,10-phenanthroline and L = O₂C(CH₂)₅CH₃ or O₂C(CH₂)₄C≡CH, were synthetized in one-pot procedures from fac -[Re(CO)₃(phen)Cl] and the corresponding carboxylic acids, and were fully characterized by IR and UV-Vis absorption spectroscopy, ¹H- and 13 C-NMR, mass spectrometry and X-ray crystallography. The compounds, which display orange luminescence, were used as probes for living cancer HeLa cell staining. Confocal microscopy revealed accumulation of both dyes in mitochondria. To investigate the mechanism of mitochondrial staining, a new non-emissive compound, fac -[Re(CO)₃(phen)L], with L = O₂C(CH₂)₃((C₅H₅)Fe(C₅H₄), i.e., containing a ferrocenyl moiety, was synthetized and characterized ( 3 ). 3 shows the same mitochondrial accumulation pattern as 1 and 2 . Emission of 3 can only be possible when ferrocene-containing ligand dissociates from the metal center to produce a species containing the luminescent fac -[Re(CO)₃(phen)]⁺ core. The release of ligands from the Re center was verified in vitro through the conjugation with model proteins. These findings suggest that the mitochondria accumulation of compounds 1 - 3 is due to the formation of luminescent fac -[Re(CO)₃(phen)]⁺ products, which react with cellular matrix molecules giving secondary products and are uptaken into the negatively charged mitochondrial membranes. Thus, reported compounds feature a rare dissociation-driven mechanism of action with great potential for biological applications.

  8. Mitochondria Targeting with Luminescent Rhenium(I Complexes

    Directory of Open Access Journals (Sweden)

    Joanna Skiba

    2017-05-01

    Full Text Available Two new neutral fac-[Re(CO3(phenL] compounds (1,2, with phen = 1,10-phenanthroline and L = O2C(CH25CH3 or O2C(CH24C≡CH, were synthetized in one-pot procedures from fac-[Re(CO3(phenCl] and the corresponding carboxylic acids, and were fully characterized by IR and UV-Vis absorption spectroscopy, 1H- and 13C-NMR, mass spectrometry and X-ray crystallography. The compounds, which display orange luminescence, were used as probes for living cancer HeLa cell staining. Confocal microscopy revealed accumulation of both dyes in mitochondria. To investigate the mechanism of mitochondrial staining, a new non-emissive compound, fac-[Re(CO3(phenL], with L = O2C(CH23((C5H5Fe(C5H4, i.e., containing a ferrocenyl moiety, was synthetized and characterized (3. 3 shows the same mitochondrial accumulation pattern as 1 and 2. Emission of 3 can only be possible when ferrocene-containing ligand dissociates from the metal center to produce a species containing the luminescent fac­[Re(CO3(phen]+ core. The release of ligands from the Re center was verified in vitro through the conjugation with model proteins. These findings suggest that the mitochondria accumulation of compounds 1–3 is due to the formation of luminescent fac-[Re(CO3(phen]+ products, which react with cellular matrix molecules giving secondary products and are uptaken into the negatively charged mitochondrial membranes. Thus, reported compounds feature a rare dissociation-driven mechanism of action with great potential for biological applications.

  9. A Powerful Mitochondria-Targeted Iron Chelator Affords High Photoprotection against Solar Ultraviolet A Radiation.

    Science.gov (United States)

    Reelfs, Olivier; Abbate, Vincenzo; Hider, Robert C; Pourzand, Charareh

    2016-08-01

    Mitochondria are the principal destination for labile iron, making these organelles particularly susceptible to oxidative damage on exposure to ultraviolet A (UVA, 320-400 nm), the oxidizing component of sunlight. The labile iron-mediated oxidative damage caused by UVA to mitochondria leads to necrotic cell death via adenosine triphosphate depletion. Therefore, targeted removal of mitochondrial labile iron via highly specific tools from these organelles may be an effective approach to protect the skin cells against the harmful effects of UVA. In this work, we designed a mitochondria-targeted hexadentate (tricatechol-based) iron chelator linked to mitochondria-homing SS-like peptides. The photoprotective potential of this compound against UVA-induced oxidative damage and cell death was evaluated in cultured primary skin fibroblasts. Our results show that this compound provides unprecedented protection against UVA-induced mitochondrial damage, adenosine triphosphate depletion, and the ensuing necrotic cell death in skin fibroblasts, and this effect is fully related to its potent iron-chelating property in the organelle. This mitochondria-targeted iron chelator has therefore promising potential for skin photoprotection against the deleterious effects of the UVA component of sunlight. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  10. Fetal programming alters reactive oxygen species production in sheep cardiac mitochondria.

    Science.gov (United States)

    von Bergen, Nicholas H; Koppenhafer, Stacia L; Spitz, Douglas R; Volk, Kenneth A; Patel, Sonali S; Roghair, Robert D; Lamb, Fred S; Segar, Jeffrey L; Scholz, Thomas D

    2009-04-01

    Exposure to an adverse intrauterine environment is recognized as an important risk factor for the development of cardiovascular disease later in life. Although oxidative stress has been proposed as a mechanism for the fetal programming phenotype, the role of mitochondrial O(2)(*-) (superoxide radical) production has not been explored. To determine whether mitochondrial ROS (reactive oxygen species) production is altered by in utero programming, pregnant ewes were given a 48-h dexamethasone (dexamethasone-exposed, 0.28 mg.kg(-1) of body weight.day(-1)) or saline (control) infusion at 27-28 days gestation (term=145 days). Intact left ventricular mitochondria and freeze-thaw mitochondrial membranes were studied from offspring at 4-months of age. AmplexRed was used to measure H(2)O(2) production. Activities of the antioxidant enzymes Mn-SOD (manganese superoxide dismutase), GPx (glutathione peroxidase) and catalase were measured. Compared with controls, a significant increase in Complex I H(2)O(2) production was found in intact mitochondria from dexamethasone-exposed animals. The treatment differences in Complex I-driven H(2)O(2) production were not seen in mitochondrial membranes. Consistent changes in H(2)O(2) production from Complex III in programmed animals were not found. Despite the increase in H(2)O(2) production in intact mitochondria from programmed animals, dexamethasone exposure significantly increased mitochondrial catalase activity, whereas Mn-SOD and GPx activities were unchanged. The results of the present study point to an increase in the rate of release of H(2)O(2) from programmed mitochondria despite an increase in catalase activity. Greater mitochondrial H(2)O(2) release into the cell may play a role in the development of adult disease following exposure to an adverse intrauterine environment.

  11. Danazol alters mitochondria metabolism of fibrocystic breast Mcf10A cells.

    Science.gov (United States)

    Irgebay, Zhazira; Yeszhan, Banu; Sen, Bhaswati; Tuleukhanov, Sultan; Brooks, Ari D; Sensenig, Richard; Orynbayeva, Zulfiya

    2017-10-01

    Fibrocystic Breast Disease (FBD) or Fibrocystic change (FC) affects about 60% of women at some time during their life. Although usually benign, it is often associated with pain and tenderness (mastalgia). The synthetic steroid danazol has been shown to be effective in reducing the pain associated with FBD, but the cellular and molecular mechanisms for its action have not been elucidated. We investigated the hypothesis that danazol acts by affecting energy metabolism. Effects of danazol on Mcf10A cells homeostasis, including mechanisms of oxidative phosphorylation, cytosolic calcium signaling and oxidative stress, were assessed by high-resolution respirometry and flow cytometry. In addition to fast physiological responses the associated genomic modulations were evaluated by Affimetrix microarray analysis. The alterations of mitochondria membrane potential and respiratory activity, downregulation of energy metabolism transcripts result in suppression of energy homeostasis and arrest of Mcf10A cells growth. The data obtained in this study impacts the recognition of direct control of mitochondria by cellular mechanisms associated with altered energy metabolism genes governing the breast tissue susceptibility and response to medication by danazol. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Nicotine facilitates nicotinic acetylcholine receptor targeting to mitochondria but makes them less susceptible to selective ligands.

    Science.gov (United States)

    Uspenska, Kateryna; Lykhmus, Olena; Gergalova, Galyna; Chernyshov, Volodymyr; Arias, Hugo R; Komisarenko, Sergiy; Skok, Maryna

    2017-08-24

    Several nicotinic acetylcholine receptor (nAChR) subtypes are expressed in mitochondria to regulate the internal pathway of apoptosis in ion channel-independent manner. However, the mechanisms of nAChR activation in mitochondria and targeting to mitochondria are still unknown. Nicotine has been shown to favor nAChR pentamer assembly, folding, and maturation on the way of biosynthesis. The idea of the present work was to determine whether nicotine affects the content, glycosylation, and function of mitochondrial nAChRs. Experiments were performed in isolated liver mitochondria from mice, that either consumed or not nicotine with the drinking water (200μL/L) for 7days. Mitochondria detergent lysates were studied by sandwich or lectin ELISA for the presence and carbohydrate composition of different nAChR subunits. Intact mitochondria were examined by flow cytometry for the binding of fluorescently labeled α-cobratoxin and were tested in functional assay of cytochrome c release under the effect of either Ca 2+ or wortmannin in the presence or absence of nAChR-selective ligands, including PNU-282987 (1nM), dihydro-β-erythroidine (DhβE, 1μM), PNU-120596 (0.3, 3, or 10μM) and desformylflustrabromine hydrochloride (dFBr, 0.001, 0.3, or 1μM). It was found that nicotine consumption increased the ratio of mitochondrial vs non-mitochondrial nAChRs in the liver, enhanced fucosylation of mitochondrial nAChRs, but prevented the binding of α-cobratoxin and the cytochrome c release-attenuating effects of nAChR-specific agonists, antagonists, or positive allosteric modulators. It is concluded that nicotine consumption in vivo favors nAChR glycosylation and trafficking to mitochondria but makes them less susceptible to the effects of specific ligands. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Mitochondria are the primary target in the induction of apoptosis by chiral ruthenium(II) polypyridyl complexes in cancer cells.

    Science.gov (United States)

    Wang, Jin-Quan; Zhang, Ping-Yu; Qian, Chen; Hou, Xiao-Juan; Ji, Liang-Nian; Chao, Hui

    2014-03-01

    A series of novel chiral ruthenium(II) polypyridyl complexes (Δ-Ru1, Λ-Ru1, Δ-Ru2, Λ-Ru2, Δ-Ru3, Λ-Ru3) were synthesized and evaluated to determine their antiproliferative activities. Colocalization, inductively coupled plasma mass spectrometry, and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay studies showed that these ruthenium(II) complexes accumulated preferentially in the mitochondria and exhibited cytotoxicity against various cancer cells in vitro. The complex Δ-Ru1 is of particular interest because it was found to have half-maximal inhibitory concentrations comparable to those of cisplatin and better activity than cisplatin against a cisplatin-resistant cell line, A549-CP/R. Δ-Ru1 induced alterations in the mitochondrial membrane potential and triggered intrinsic mitochondria-mediated apoptosis in HeLa cells, which involved the regulation of Bcl-2 family members and the activation of caspases. Taken together, these data suggest that Δ-Ru1 may be a novel mitochondria-targeting anticancer agent.

  14. Mitochondria-Targeted Antioxidant Prevents Cardiac Dysfunction Induced by Tafazzin Gene Knockdown in Cardiac Myocytes

    Directory of Open Access Journals (Sweden)

    Quan He

    2014-01-01

    Full Text Available Tafazzin, a mitochondrial acyltransferase, plays an important role in cardiolipin side chain remodeling. Previous studies have shown that dysfunction of tafazzin reduces cardiolipin content, impairs mitochondrial function, and causes dilated cardiomyopathy in Barth syndrome. Reactive oxygen species (ROS have been implicated in the development of cardiomyopathy and are also the obligated byproducts of mitochondria. We hypothesized that tafazzin knockdown increases ROS production from mitochondria, and a mitochondria-targeted antioxidant prevents tafazzin knockdown induced mitochondrial and cardiac dysfunction. We employed cardiac myocytes transduced with an adenovirus containing tafazzin shRNA as a model to investigate the effects of the mitochondrial antioxidant, mito-Tempo. Knocking down tafazzin decreased steady state levels of cardiolipin and increased mitochondrial ROS. Treatment of cardiac myocytes with mito-Tempo normalized tafazzin knockdown enhanced mitochondrial ROS production and cellular ATP decline. Mito-Tempo also significantly abrogated tafazzin knockdown induced cardiac hypertrophy, contractile dysfunction, and cell death. We conclude that mitochondria-targeted antioxidant prevents cardiac dysfunction induced by tafazzin gene knockdown in cardiac myocytes and suggest mito-Tempo as a potential therapeutic for Barth syndrome and other dilated cardiomyopathies resulting from mitochondrial oxidative stress.

  15. The energy blocker inside the power house: Mitochondria targeted delivery of 3-bromopyruvate.

    Science.gov (United States)

    Marrache, Sean; Dhar, Shanta

    2015-03-01

    A key hallmark of many aggressive cancers is accelerated glucose metabolism. The enzymes that catalyze the first step of glucose metabolism are hexokinases. High levels of hexokinase 2 (HK2) are found in cancer cells, but only in a limited number of normal tissues. Metabolic reprogramming of cancer cells using the energy blocker, 3-bromopyruvate (3-BP) that inhibits HK2 has the potential to provide tumor-specific anticancer agents. However, the unique structural and functional characteristics of mitochondria prohibit selective subcellular targeting of 3-BP to modulate the function of this organelle for therapeutic gain. A mitochondria targeted gold nanoparticle (T-3-BP-AuNP) decorated with 3-BP and delocalized lipophilic triphenylphosphonium cations to target the mitochondrial membrane potential (Δ ψ m ) was developed for delivery of 3-BP to cancer cell mitochondria by taking advantage of higher Δ ψ m in cancer cells compared to normal cells. In vitro studies demonstrated enhanced anticancer activity of T-3-BP-AuNPs compared to the non-targeted construct NT-3-BP-AuNP or free 3-BP. The anticancer activity of T-3-BP-AuNP was further enhanced upon laser irradiation by exciting the surface plasmon resonance band of AuNP and thereby utilizing a combination of 3-BP chemotherapeutic and AuNP photothermal effects. The less toxic behavior of T-3-BPNPs in normal mesenchymal stem cells indicated that these NPs preferentially kill cancer cells. T-3-BP-AuNPs showed enhanced ability to modulate cancer cell metabolism by inhibiting glycolysis as well as demolishing mitochondrial oxidative phosphorylation. Our findings demonstrated that concerted chemo-photothermal treatment of glycolytic cancer cells with a single NP capable of targeting mitochondria mediating simultaneous release of a glycolytic inhibitor and photothermal ablation may have promise as a new anticancer therapy.

  16. Mitochondria-targeting nanomedicine: An effective and potent strategy against aminoglycosides-induced ototoxicity.

    Science.gov (United States)

    Zhou, Shuang; Sun, Yanhui; Kuang, Xiao; Hou, Shanshan; Yang, YinXian; Wang, Zhenjie; Liu, Hongzhuo

    2018-04-21

    We report a proof-of-concept for the development of mitochondria-targeting nanoparticles (NPs) loaded with geranylgeranylacetone (GGA) to protect against a wide range of gentamicin-induced ototoxicity symptoms in a zebrafish model. The polymeric NPs were functionalized with a mitochondrial-homing peptide (d‑Arg‑Dmt‑Orn‑Phe‑NH 2 ) and exhibited greater mitochondrial uptake and lower gentamicin uptake in hair cells via mechanotransduction (MET) channels and tuned machinery in the hair bundle than the ordinary NPs did. Blockade of MET channels rapidly reversed this effect, indicating the reversible responses of hair cells to the targeting NPs were mediated by MET channels. Pretreatment of hair cells with mitochondria-targeting GGA-loaded NPs exhibited a superior acute or chronic protective efficacy against subsequent exposure to gentamicin compared with unmodified formulations. Mitochondrial delivery regulating the death pathway of hair cells appeared to cause the therapeutic failure of untargeted NPs. Thus, peptide-directed mitochondria-targeting NPs may represent a novel therapeutic strategy for mitochondrial dysfunction-linked diseases. Copyright © 2018 Elsevier B.V. All rights reserved.

  17. Preventive effect of dietary quercetin on disuse muscle atrophy by targeting mitochondria in denervated mice.

    Science.gov (United States)

    Mukai, Rie; Matsui, Naoko; Fujikura, Yutaka; Matsumoto, Norifumi; Hou, De-Xing; Kanzaki, Noriyuki; Shibata, Hiroshi; Horikawa, Manabu; Iwasa, Keiko; Hirasaka, Katsuya; Nikawa, Takeshi; Terao, Junji

    2016-05-01

    Quercetin is a major dietary flavonoid in fruits and vegetables. We aimed to clarify the preventive effect of dietary quercetin on disuse muscle atrophy and the underlying mechanisms. We established a mouse denervation model by cutting the sciatic nerve in the right leg (SNX surgery) to lack of mobilization in hind-limb. Preintake of a quercetin-mixed diet for 14days before SNX surgery prevented loss of muscle mass and atrophy of muscle fibers in the gastrocnemius muscle (GM). Phosphorylation of Akt, a key phosphorylation pathway of suppression of protein degradation, was activated in the quercetin-mixed diet group with and without SNX surgery. Intake of a quercetin-mixed diet suppressed the generation of hydrogen peroxide originating from mitochondria and elevated mitochondrial peroxisome proliferator-activated receptor-γ coactivator 1α mRNA expression as well as NADH dehydrogenase 4 expression in the GM with SNX surgery. Quercetin and its conjugated metabolites reduced hydrogen peroxide production in the mitochondrial fraction obtained from atrophied muscle. In C2C12 myotubes, quercetin reached the mitochondrial fraction. These findings suggest that dietary quercetin can prevent disuse muscle atrophy by targeting mitochondria in skeletal muscle tissue through protecting mitochondria from decreased biogenesis and reducing mitochondrial hydrogen peroxide release, which can be related to decreased hydrogen peroxide production and/or improvements on antioxidant capacity of mitochondria. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. A mitochondria-targeted mass spectrometry probe to detect glyoxals: implications for diabetes☆

    Science.gov (United States)

    Pun, Pamela Boon Li; Logan, Angela; Darley-Usmar, Victor; Chacko, Balu; Johnson, Michelle S.; Huang, Guang W.; Rogatti, Sebastian; Prime, Tracy A.; Methner, Carmen; Krieg, Thomas; Fearnley, Ian M.; Larsen, Lesley; Larsen, David S.; Menger, Katja E.; Collins, Yvonne; James, Andrew M.; Kumar, G.D. Kishore; Hartley, Richard C.; Smith, Robin A.J.; Murphy, Michael P.

    2014-01-01

    The glycation of protein and nucleic acids that occurs as a consequence of hyperglycemia disrupts cell function and contributes to many pathologies, including those associated with diabetes and aging. Intracellular glycation occurs after the generation of the reactive 1,2-dicarbonyls methylglyoxal and glyoxal, and disruption of mitochondrial function is associated with hyperglycemia. However, the contribution of these reactive dicarbonyls to mitochondrial damage in pathology is unclear owing to uncertainties about their levels within mitochondria in cells and in vivo. To address this we have developed a mitochondria-targeted reagent (MitoG) designed to assess the levels of mitochondrial dicarbonyls within cells. MitoG comprises a lipophilic triphenylphosphonium cationic function, which directs the molecules to mitochondria within cells, and an o-phenylenediamine moiety that reacts with dicarbonyls to give distinctive and stable products. The extent of accumulation of these diagnostic heterocyclic products can be readily and sensitively quantified by liquid chromatography–tandem mass spectrometry, enabling changes to be determined. Using the MitoG-based analysis we assessed the formation of methylglyoxal and glyoxal in response to hyperglycemia in cells in culture and in the Akita mouse model of diabetes in vivo. These findings indicated that the levels of methylglyoxal and glyoxal within mitochondria increase during hyperglycemia both in cells and in vivo, suggesting that they can contribute to the pathological mitochondrial dysfunction that occurs in diabetes and aging. PMID:24316194

  19. A mitochondria-targeted mass spectrometry probe to detect glyoxals: implications for diabetes.

    Science.gov (United States)

    Pun, Pamela Boon Li; Logan, Angela; Darley-Usmar, Victor; Chacko, Balu; Johnson, Michelle S; Huang, Guang W; Rogatti, Sebastian; Prime, Tracy A; Methner, Carmen; Krieg, Thomas; Fearnley, Ian M; Larsen, Lesley; Larsen, David S; Menger, Katja E; Collins, Yvonne; James, Andrew M; Kumar, G D Kishore; Hartley, Richard C; Smith, Robin A J; Murphy, Michael P

    2014-02-01

    The glycation of protein and nucleic acids that occurs as a consequence of hyperglycemia disrupts cell function and contributes to many pathologies, including those associated with diabetes and aging. Intracellular glycation occurs after the generation of the reactive 1,2-dicarbonyls methylglyoxal and glyoxal, and disruption of mitochondrial function is associated with hyperglycemia. However, the contribution of these reactive dicarbonyls to mitochondrial damage in pathology is unclear owing to uncertainties about their levels within mitochondria in cells and in vivo. To address this we have developed a mitochondria-targeted reagent (MitoG) designed to assess the levels of mitochondrial dicarbonyls within cells. MitoG comprises a lipophilic triphenylphosphonium cationic function, which directs the molecules to mitochondria within cells, and an o-phenylenediamine moiety that reacts with dicarbonyls to give distinctive and stable products. The extent of accumulation of these diagnostic heterocyclic products can be readily and sensitively quantified by liquid chromatography-tandem mass spectrometry, enabling changes to be determined. Using the MitoG-based analysis we assessed the formation of methylglyoxal and glyoxal in response to hyperglycemia in cells in culture and in the Akita mouse model of diabetes in vivo. These findings indicated that the levels of methylglyoxal and glyoxal within mitochondria increase during hyperglycemia both in cells and in vivo, suggesting that they can contribute to the pathological mitochondrial dysfunction that occurs in diabetes and aging. Copyright © 2013 The Authors. Published by Elsevier Inc. All rights reserved.

  20. Mitochondria: Targeting mitochondrial reactive oxygen species with mitochondriotropic polyphenolic-based antioxidants.

    Science.gov (United States)

    Teixeira, José; Deus, Cláudia M; Borges, Fernanda; Oliveira, Paulo J

    2018-04-01

    Mitochondrial function and regulation of redox balance is fundamental in controlling cellular life and death pathways. Antioxidants have been used to counteract disruption of redox networks, normally associated with progressive loss of cell homeostasis and disease pathophysiology, although therapeutic success is limited mainly due to pharmacokinetic drawbacks. Attempts to improve mitochondrial function in a range of diseases spurred active drug discovery efforts. Currently, the most effective strategy to deliver drugs to mitochondria is the covalent link of lipophilic cations to the bioactive compound. Although targeting mitochondrial oxidative stress with antioxidants has been demonstrated, clinical use has been hampered by several challenges, with no FDA-approved drug so far. Development of new mitochondriotropic antioxidant agents based on dietary polyphenols has recently gained momentum. Due to their nature, mitochondria-targeted multi-functional antioxidants can trigger stress responses and contribute to tissue protection through hormesis mechanisms, inhibiting excessive mitochondrial ROS production and associated diseases. Copyright © 2018 Elsevier Ltd. All rights reserved.

  1. Penetrating cation/fatty acid anion pair as a mitochondria-targeted protonophore

    Science.gov (United States)

    Severin, Fedor F.; Severina, Inna I.; Antonenko, Yury N.; Rokitskaya, Tatiana I.; Cherepanov, Dmitry A.; Mokhova, Elena N.; Vyssokikh, Mikhail Yu.; Pustovidko, Antonina V.; Markova, Olga V.; Yaguzhinsky, Lev S.; Korshunova, Galina A.; Sumbatyan, Nataliya V.; Skulachev, Maxim V.; Skulachev, Vladimir P.

    2010-01-01

    A unique phenomenon of mitochondria-targeted protonophores is described. It consists in a transmembrane H+-conducting fatty acid cycling mediated by penetrating cations such as 10-(6’-plastoquinonyl)decyltriphenylphosphonium (SkQ1) or dodecyltriphenylphosphonium (C12TPP). The phenomenon has been modeled by molecular dynamics and directly proved by experiments on bilayer planar phospholipid membrane, liposomes, isolated mitochondria, and yeast cells. In bilayer planar phospholipid membrane, the concerted action of penetrating cations and fatty acids is found to result in conversion of a pH gradient (ΔpH) to a membrane potential (Δψ) of the Nernstian value (about 60 mV Δψ at ΔpH = 1). A hydrophobic cation with localized charge (cetyltrimethylammonium) failed to substitute for hydrophobic cations with delocalized charge. In isolated mitochondria, SkQ1 and C12TPP, but not cetyltrimethylammonium, potentiated fatty acid-induced (i) uncoupling of respiration and phosphorylation, and (ii) inhibition of H2O2 formation. In intact yeast cells, C12TPP stimulated respiration regardless of the extracellular pH value, whereas a nontargeted protonophorous uncoupler (trifluoromethoxycarbonylcyanide phenylhydrazone) stimulated respiration at pH 5 but not at pH 3. Hydrophobic penetrating cations might be promising to treat obesity, senescence, and some kinds of cancer that require mitochondrial hyperpolarization. PMID:20080732

  2. TU-F-CAMPUS-T-04: Using Gold Nanoparticles to Target Mitochondria in Radiation Therapy

    International Nuclear Information System (INIS)

    McNamara, A; McMahon, S; Lin, Y; Paganetti, H; Schuemann, J; Kuncic, Z

    2015-01-01

    Purpose: The mitochondrion, like the cell nucleus, contains genetic material and plays several critical roles that determine the cell viability, including neutralization of free radicals within the cell. Studies have shown that irradiated cells with impaired mitochondria will incur more damage to the cell nucleus. This study investigates the potential use of GNPs to enhance radiation-induced damage to the organelle. Methods: The compositions of the organelles of a JURKAT cell were determined experimentally. Using Monte Carlo simulations, we investigate the significance of dose enhancement in a monoenergetic (10–50 keV and 6 MeV) x-ray irradiated cell cytoplasm, consisting of the experimentally determined composition. We also investigate the track structure of secondary electrons in the mitochondria using Geant4-DNA in the presence and absence of GNPs for incident protons and photons. The biological effect was determined using an approach based on the local effect model, assuming the mitochondrial DNA (mtDNA) was the primary target. Results: Adding 0.01% of gold to the cell cytoplasm material can cause substantial dose enhancement, dependent on the incident x-ray energy. Track structure Monte Carlo (MC) simulations show an increased number of ionization events within the mitochondrion structure. The close proximity of GNPs to the mtDNA storing nucleoid may cause the mtDNA to receive doses above ∼100 Gy for keV x-rays, leading to mitochondrial dysfunction. Conclusion: A substantial increase in ionization events can occur in the mitochondria in the presence of GNPs. If GNPs can be delivered to tumors and attached to a sufficient number of mitochondria inside the tumor cells, mitochondrial induced cell death could be a prevalent cause of cell death. The biological structures developed here will be included in the biological MC toolkit, TOPAS-nBio

  3. TU-F-CAMPUS-T-04: Using Gold Nanoparticles to Target Mitochondria in Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    McNamara, A [Massachusetts General Hospital & Harvard Med. Sch., Boston, MA (United States); McMahon, S [Massachusetts General Hospital, Boston, Ma (United States); Lin, Y [Massachusetts General Hospital and Harvard Medical School, Boston, MA (United States); Paganetti, H; Schuemann, J [Massachusetts General Hospital, Boston, MA (United States); Kuncic, Z [University of Sydney, Sydney, NSW (Australia)

    2015-06-15

    Purpose: The mitochondrion, like the cell nucleus, contains genetic material and plays several critical roles that determine the cell viability, including neutralization of free radicals within the cell. Studies have shown that irradiated cells with impaired mitochondria will incur more damage to the cell nucleus. This study investigates the potential use of GNPs to enhance radiation-induced damage to the organelle. Methods: The compositions of the organelles of a JURKAT cell were determined experimentally. Using Monte Carlo simulations, we investigate the significance of dose enhancement in a monoenergetic (10–50 keV and 6 MeV) x-ray irradiated cell cytoplasm, consisting of the experimentally determined composition. We also investigate the track structure of secondary electrons in the mitochondria using Geant4-DNA in the presence and absence of GNPs for incident protons and photons. The biological effect was determined using an approach based on the local effect model, assuming the mitochondrial DNA (mtDNA) was the primary target. Results: Adding 0.01% of gold to the cell cytoplasm material can cause substantial dose enhancement, dependent on the incident x-ray energy. Track structure Monte Carlo (MC) simulations show an increased number of ionization events within the mitochondrion structure. The close proximity of GNPs to the mtDNA storing nucleoid may cause the mtDNA to receive doses above ∼100 Gy for keV x-rays, leading to mitochondrial dysfunction. Conclusion: A substantial increase in ionization events can occur in the mitochondria in the presence of GNPs. If GNPs can be delivered to tumors and attached to a sufficient number of mitochondria inside the tumor cells, mitochondrial induced cell death could be a prevalent cause of cell death. The biological structures developed here will be included in the biological MC toolkit, TOPAS-nBio.

  4. Therapeutic Targeting of the Mitochondria Initiates Excessive Superoxide Production and Mitochondrial Depolarization Causing Decreased mtDNA Integrity.

    Science.gov (United States)

    Pokrzywinski, Kaytee L; Biel, Thomas G; Kryndushkin, Dmitry; Rao, V Ashutosh

    2016-01-01

    Mitochondrial dysregulation is closely associated with excessive reactive oxygen species (ROS) production. Altered redox homeostasis has been implicated in the onset of several diseases including cancer. Mitochondrial DNA (mtDNA) and proteins are particularly sensitive to ROS as they are in close proximity to the respiratory chain (RC). Mitoquinone (MitoQ), a mitochondria-targeted redox agent, selectively damages breast cancer cells possibly through damage induced via enhanced ROS production. However, the effects of MitoQ and other triphenylphosphonium (TPP+) conjugated agents on cancer mitochondrial homeostasis remain unknown. The primary objective of this study was to determine the impact of mitochondria-targeted agent [(MTAs) conjugated to TPP+: mitoTEMPOL, mitoquinone and mitochromanol-acetate] on mitochondrial physiology and mtDNA integrity in breast (MDA-MB-231) and lung (H23) cancer cells. The integrity of the mtDNA was assessed by quantifying the degree of mtDNA fragmentation and copy number, as well as by measuring mitochondrial proteins essential to mtDNA stability and maintenance (TFAM, SSBP1, TWINKLE, POLG and POLRMT). Mitochondrial status was evaluated by measuring superoxide production, mitochondrial membrane depolarization, oxygen consumption, extracellular acidification and mRNA or protein levels of the RC complexes along with TCA cycle activity. In this study, we demonstrated that all investigated MTAs impair mitochondrial health and decrease mtDNA integrity in MDA-MB-231 and H23 cells. However, differences in the degree of mitochondrial damage and mtDNA degradation suggest unique properties among each MTA that may be cell line, dose and time dependent. Collectively, our study indicates the potential for TPP+ conjugated molecules to impair breast and lung cancer cells by targeting mitochondrial homeostasis.

  5. Mitochondria-Targeted Antioxidant Mito-Tempo Protects Against Aldosterone-Induced Renal Injury In Vivo

    Directory of Open Access Journals (Sweden)

    Wei Ding

    2017-11-01

    Full Text Available Background/Aims: Growing evidence suggests mitochondrial dysfunction (MtD and the Nlrp3 inflammasome play critical roles in chronic kidney disease (CKD progression. We previously reported that Aldosterone (Aldo-induced renal injury in vitro is directly caused by mitochondrial reactive oxygen species (mtROS-mediated activation of the Nlrp3 inflammasome. Here we aimed to determine whether a mitochondria-targeted antioxidant (Mito-Tempo could prevent Aldo-induced kidney damage in vivo. Methods: C57BL/6J mice were treated with Aldo and/or Mito-Tempo (or ethanol as a control for 4 weeks. Renal injury was evaluated by Periodic Acid-Schiff reagent or Masson’s trichrome staining and electron microscopy. ROS were measured by DCFDA fluorescence and ELISA. MtD was determined by real-time PCR and electron microscopy. Activation of the Nlrp3 inflammasome and endoplasmic reticulum stress (ERS was detected via western blot. Results: Compared with control mice, Aldo-infused mice showed impaired renal function, increased mtROS production and MtD, Nlrp3 inflammasome activation, and elevated ERS. We showed administration of Mito-Tempo significantly improved renal function and MtD, and reduced Nlrp3 inflammasome activation and ERS in vivo. Conclusion: Mitochondria-targeted antioxidants may attenuate Aldo-infused renal injury by inhibiting MtD, the Nlrp3 inflammasome, and ERS in vivo. Therefore, targeting mtROS might be an effective strategy for preventing CKD.

  6. MsrA Overexpression Targeted to the Mitochondria, but Not Cytosol, Preserves Insulin Sensitivity in Diet-Induced Obese Mice.

    Directory of Open Access Journals (Sweden)

    JennaLynn Hunnicut

    Full Text Available There is growing evidence that oxidative stress plays an integral role in the processes by which obesity causes type 2 diabetes. We previously identified that mice lacking the protein oxidation repair enzyme methionine sulfoxide reductase A (MsrA are particularly prone to obesity-induced insulin resistance suggesting an unrecognized role for this protein in metabolic regulation. The goals of this study were to test whether increasing the expression of MsrA in mice can protect against obesity-induced metabolic dysfunction and to elucidate the potential underlying mechanisms. Mice with increased levels of MsrA in the mitochondria (TgMito MsrA or in the cytosol (TgCyto MsrA were fed a high fat/high sugar diet and parameters of glucose homeostasis were monitored. Mitochondrial content, markers of mitochondrial proteostasis and mitochondrial energy utilization were assessed. TgMito MsrA, but not TgCyto MsrA, mice remain insulin sensitive after high fat feeding, though these mice are not protected from obesity. This metabolically healthy obese phenotype of TgMito MsrA mice is not associated with changes in mitochondrial number or biogenesis or with a reduction of proteostatic stress in the mitochondria. However, our data suggest that increased mitochondrial MsrA can alter metabolic homeostasis under diet-induced obesity by activating AMPK signaling, thereby defining a potential mechanism by which this genetic alteration can prevent insulin resistance without affecting obesity. Our data suggest that identification of targets that maintain and regulate the integrity of the mitochondrial proteome, particular against oxidative damage, may play essential roles in the protection against metabolic disease.

  7. Mitochondria, Bioenergetics and Excitotoxicity: New Therapeutic Targets in Perinatal Brain Injury

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    Bryan Leaw

    2017-07-01

    Full Text Available Injury to the fragile immature brain is implicated in the manifestation of long-term neurological disorders, including childhood disability such as cerebral palsy, learning disability and behavioral disorders. Advancements in perinatal practice and improved care mean the majority of infants suffering from perinatal brain injury will survive, with many subtle clinical symptoms going undiagnosed until later in life. Hypoxic-ischemia is the dominant cause of perinatal brain injury, and constitutes a significant socioeconomic burden to both developed and developing countries. Therapeutic hypothermia is the sole validated clinical intervention to perinatal asphyxia; however it is not always neuroprotective and its utility is limited to developed countries. There is an urgent need to better understand the molecular pathways underlying hypoxic-ischemic injury to identify new therapeutic targets in such a small but critical therapeutic window. Mitochondria are highly implicated following ischemic injury due to their roles as the powerhouse and main energy generators of the cell, as well as cell death processes. While the link between impaired mitochondrial bioenergetics and secondary energy failure following loss of high-energy phosphates is well established after hypoxia-ischemia (HI, there is emerging evidence that the roles of mitochondria in disease extend far beyond this. Indeed, mitochondrial turnover, including processes such as mitochondrial biogenesis, fusion, fission and mitophagy, affect recovery of neurons after injury and mitochondria are involved in the regulation of the innate immune response to inflammation. This review article will explore these mitochondrial pathways, and finally will summarize past and current efforts in targeting these pathways after hypoxic-ischemic injury, as a means of identifying new avenues for clinical intervention.

  8. Novel Mitochondria-Targeted Furocoumarin Derivatives as Possible Anti-Cancer Agents

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    Andrea Mattarei

    2018-04-01

    Full Text Available Targeting small molecules to appropriate subcellular compartments is a way to increase their selectivity and effectiveness while minimizing side effects. This can be accomplished either by stably incorporating specific “homing” properties into the structure of the active principle, or by attaching to it a targeting moiety via a labile linker, i.e., by producing a “targeting pro-drug.” Mitochondria are a recognized therapeutic target in oncology, and blocking the population of the potassium channel Kv1.3 residing in the inner mitochondrial membrane (mtKv1.3 has been shown to cause apoptosis of cancerous cells expressing it. These concepts have led us to devise novel, mitochondria-targeted, membrane-permeant drug candidates containing the furocoumarin (psoralenic ring system and the triphenylphosphonium (TPP lipophilic cation. The strategy has proven effective in various cancer models, including pancreatic ductal adenocarcinoma, melanoma, and glioblastoma, stimulating us to devise further novel molecules to extend and diversify the range of available drugs of this type. New compounds were synthesized and tested in vitro; one of them—a prodrug in which the coumarinic moiety and the TPP group are linked by a bridge comprising a labile carbonate bond system—proved quite effective in in vitro cytotoxicity assays. Selective death induction is attributed to inhibition of mtKv1.3. This results in oxidative stress, which is fatal for the already-stressed malignant cells. This compound may thus be a candidate drug for the mtKv1.3-targeting therapeutic approach.

  9. Optogenetic control of mitochondrial metabolism and Ca2+ signaling by mitochondria-targeted opsins.

    Science.gov (United States)

    Tkatch, Tatiana; Greotti, Elisa; Baranauskas, Gytis; Pendin, Diana; Roy, Soumitra; Nita, Luliaoana I; Wettmarshausen, Jennifer; Prigge, Matthias; Yizhar, Ofer; Shirihai, Orian S; Fishman, Daniel; Hershfinkel, Michal; Fleidervish, Ilya A; Perocchi, Fabiana; Pozzan, Tullio; Sekler, Israel

    2017-06-27

    Key mitochondrial functions such as ATP production, Ca 2+ uptake and release, and substrate accumulation depend on the proton electrochemical gradient (ΔμH + ) across the inner membrane. Although several drugs can modulate ΔμH + , their effects are hardly reversible, and lack cellular specificity and spatial resolution. Although channelrhodopsins are widely used to modulate the plasma membrane potential of excitable cells, mitochondria have thus far eluded optogenetic control. Here we describe a toolkit of optometabolic constructs based on selective targeting of channelrhodopsins with distinct functional properties to the inner mitochondrial membrane of intact cells. We show that our strategy enables a light-dependent control of the mitochondrial membrane potential (Δψ m ) and coupled mitochondrial functions such as ATP synthesis by oxidative phosphorylation, Ca 2+ dynamics, and respiratory metabolism. By directly modulating Δψ m , the mitochondria-targeted opsins were used to control complex physiological processes such as spontaneous beats in cardiac myocytes and glucose-dependent ATP increase in pancreatic β-cells. Furthermore, our optometabolic tools allow modulation of mitochondrial functions in single cells and defined cell regions.

  10. Mitochondria targeted peptides protect against 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine neurotoxicity.

    Science.gov (United States)

    Yang, Lichuan; Zhao, Kesheng; Calingasan, Noel Y; Luo, Guoxiong; Szeto, Hazel H; Beal, M Flint

    2009-09-01

    A large body of evidence suggests that mitochondrial dysfunction and oxidative damage play a role in the pathogenesis of Parkinson's disease (PD). A number of antioxidants have been effective in animal models of PD. We have developed a family of mitochondria-targeted peptides that can protect against mitochondrial swelling and apoptosis (SS peptides). In this study, we examined the ability of two peptides, SS-31 and SS-20, to protect against 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) neurotoxicity in mice. SS-31 produced dose-dependent complete protection against loss of dopamine and its metabolites in striatum, as well as loss of tyrosine hydroxylase immunoreactive neurons in substantia nigra pars compacta. SS-20, which does not possess intrinsic ability in scavenging reactive oxygen species, also demonstrated significant neuroprotective effects on dopaminergic neurons of MPTP-treated mice. Both SS-31 and SS-20 were very potent (nM) in preventing MPP+ (1-methyl-4-phenylpyridinium)-induced cell death in cultured dopamine cells (SN4741). Studies with isolated mitochondria showed that both SS-31 and SS-20 prevented MPP+-induced inhibition of oxygen consumption and ATP production, and mitochondrial swelling. These findings provide strong evidence that these neuroprotective peptides, which target both mitochondrial dysfunction and oxidative damage, are a promising approach for the treatment of PD.

  11. Mitochondria Targeted Nanoscale Zeolitic Imidazole Framework-90 for ATP Imaging in Live Cells.

    Science.gov (United States)

    Deng, Jingjing; Wang, Kai; Wang, Ming; Yu, Ping; Mao, Lanqun

    2017-04-26

    Zeolitic imidazole frameworks (ZIFs) are an emerging class of functional porous materials with promising biomedical applications such as molecular sensing and intracellular drug delivery. We report herein the first example of using nanoscale ZIFs (i.e., ZIF-90), self-assembled from Zn 2+ and imidazole-2-carboxyaldehyde, to target subcellular mitochondria and image dynamics of mitochondrial ATP in live cells. Encapsulation of fluorescent Rhodamine B (RhB) into ZIF-90 suppresses the emission of RhB, while the competitive coordination between ATP and the metal node of ZIF-90 dissembles ZIFs, resulting in the release of RhB for ATP sensing. With this method, we are able to image mitochondrial ATP in live cells and study the ATP level fluctuation in cellular glycolysis and apoptosis processes. The strategy reported here could be further extended to tune nanoscale ZIFs inside live cells for targeted delivery of therapeutics to subcellular organelles for advanced biomedical applications.

  12. Fructose-Drinking Water Induced Nonalcoholic Fatty Liver Disease and Ultrastructural Alteration of Hepatocyte Mitochondria in Male Wistar Rat

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    Norshalizah Mamikutty

    2015-01-01

    Full Text Available Background. Nonalcoholic fatty liver disease (NAFLD is one of the complications of the metabolic syndrome. It encompasses a wide range of disease spectrum from simple steatosis to liver cirrhosis. Structural alteration of hepatic mitochondria might be involved in the pathogenesis of NAFLD. Aims. In the present study, we used a newly established model of fructose-induced metabolic syndrome in male Wistar rats in order to investigate the ultrastructural changes in hepatic mitochondria that occur with fructose consumption and their association with NAFLD pathogenesis. Methods. The concentration of fructose-drinking water (FDW used in this study was 20%. Six male Wistar rats were supplemented with FDW 20% for eight weeks. Body composition and metabolic parameters were measured before and after 8 weeks of FDW 20%. Histomorphology of the liver was evaluated and ultrastructural changes of mitochondria were assessed with transmission electron micrograph. Results. After 8 weeks of fructose consumption, the animals developed several features of the metabolic syndrome. Moreover, fructose consumption led to the development of macrovesicular hepatic steatosis and mitochondrial ultrastructural changes, such as increase in mitochondrial size, disruption of the cristae, and reduction of matrix density. Conclusion. We conclude that in male Wistar rat 8-week consumption of FDW 20% leads to NAFLD likely via mitochondrial structural alteration.

  13. Targeting mitochondria by Zn(II)N-alkylpyridylporphyrins: the impact of compound sub-mitochondrial partition on cell respiration and overall photodynamic efficacy.

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    Odeh, Ahmad M; Craik, James D; Ezzeddine, Rima; Tovmasyan, Artak; Batinic-Haberle, Ines; Benov, Ludmil T

    2014-01-01

    Mitochondria play a key role in aerobic ATP production and redox control. They harness crucial metabolic pathways and control cell death mechanisms, properties that make these organelles essential for survival of most eukaryotic cells. Cancer cells have altered cell death pathways and typically show a shift towards anaerobic glycolysis for energy production, factors which point to mitochondria as potential culprits in cancer development. Targeting mitochondria is an attractive approach to tumor control, but design of pharmaceutical agents based on rational approaches is still not well established. The aim of this study was to investigate which structural features of specially designed Zn(II)N-alkylpyridylporphyrins would direct them to mitochondria and to particular mitochondrial targets. Since Zn(II)N-alkylpyridylporphyrins can act as highly efficient photosensitizers, their localization can be confirmed by photodamage to particular mitochondrial components. Using cultured LS174T adenocarcinoma cells, we found that subcellular distribution of Zn-porphyrins is directed by the nature of the substituents attached to the meso pyridyl nitrogens at the porphyrin ring. Increasing the length of the aliphatic chain from one carbon (methyl) to six carbons (hexyl) increased mitochondrial uptake of the compounds. Such modifications also affected sub-mitochondrial distribution of the Zn-porphyrins. The amphiphilic hexyl derivative (ZnTnHex-2-PyP) localized in the vicinity of cytochrome c oxidase complex, causing its inactivation during illumination. Photoinactivation of critical cellular targets explains the superior efficiency of the hexyl derivative in causing mitochondrial photodamage, and suppressing cellular respiration and survival. Design of potent photosensitizers and redox-active scavengers of free radicals should take into consideration not only selective organelle uptake and localization, but also selective targeting of critical macromolecular structures.

  14. Insulin and Insulin-Sensitizing Drugs in Neurodegeneration: Mitochondria as Therapeutic Targets

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    Paula I. Moreira

    2009-12-01

    Full Text Available Insulin, besides its glucose lowering effects, is involved in the modulation of lifespan, aging and memory and learning processes. As the population ages, neurodegenerative disorders become epidemic and a connection between insulin signaling dysregulation, cognitive decline and dementia has been established. Mitochondria are intracellular organelles that despite playing a critical role in cellular metabolism are also one of the major sources of reactive oxygen species. Mitochondrial dysfunction, oxidative stress and neuroinflammation, hallmarks of neurodegeneration, can result from impaired insulin signaling. Insulin-sensitizing drugs such as the thiazolidinediones are a new class of synthetic compounds that potentiate insulin action in the target tissues and act as specific agonists of the peroxisome proliferator-activated receptor gamma (PPAR-γ. Recently, several PPAR agonists have been proposed as novel and possible therapeutic agents for neurodegenerative disorders. Indeed, the literature shows that these agents are able to protect against mitochondrial dysfunction, oxidative damage, inflammation and apoptosis. This review discusses the role of mitochondria and insulin signaling in normal brain function and in neurodegeneration. Furthermore, the potential protective role of insulin and insulin sensitizers in Alzheimer´s, Parkinson´s and Huntington´s diseases and amyotrophic lateral sclerosis will be also discussed.

  15. Mitochondria-Targeted Vitamin E Protects Skin from UVB-Irradiation.

    Science.gov (United States)

    Kim, Won-Serk; Kim, Ikyon; Kim, Wang-Kyun; Choi, Ju-Yeon; Kim, Doo Yeong; Moon, Sung-Guk; Min, Hyung-Keun; Song, Min-Kyu; Sung, Jong-Hyuk

    2016-05-01

    Mitochondria-targeted vitamin E (MVE) is designed to accumulate within mitochondria and is applied to decrease mitochondrial oxidative damage. However, the protective effects of MVE in skin cells have not been identified. We investigated the protective effect of MVE against UVB in dermal fibroblasts and immortalized human keratinocyte cell line (HaCaT). In addition, we studied the wound-healing effect of MVE in animal models. We found that MVE increased the proliferation and survival of fibroblasts at low concentration (i.e., nM ranges). In addition, MVE increased collagen production and downregulated matrix metalloproteinase1. MVE also increased the proliferation and survival of HaCaT cells. UVB increased reactive oxygen species (ROS) production in fibroblasts and HaCaT cells, while MVE decreased ROS production at low concentration. In an animal experiment, MVE accelerated wound healing from laser-induced skin damage. These results collectively suggest that low dose MVE protects skin from UVB irradiation. Therefore, MVE can be developed as a cosmetic raw material.

  16. Brain region-specific altered expression and association of mitochondria-related genes in autism.

    Science.gov (United States)

    Anitha, Ayyappan; Nakamura, Kazuhiko; Thanseem, Ismail; Yamada, Kazuo; Iwayama, Yoshimi; Toyota, Tomoko; Matsuzaki, Hideo; Miyachi, Taishi; Yamada, Satoru; Tsujii, Masatsugu; Tsuchiya, Kenji J; Matsumoto, Kaori; Iwata, Yasuhide; Suzuki, Katsuaki; Ichikawa, Hironobu; Sugiyama, Toshiro; Yoshikawa, Takeo; Mori, Norio

    2012-11-01

    Mitochondrial dysfunction (MtD) has been observed in approximately five percent of children with autism spectrum disorders (ASD). MtD could impair highly energy-dependent processes such as neurodevelopment, thereby contributing to autism. Most of the previous studies of MtD in autism have been restricted to the biomarkers of energy metabolism, while most of the genetic studies have been based on mutations in the mitochondrial DNA (mtDNA). Despite the mtDNA, most of the proteins essential for mitochondrial replication and function are encoded by the genomic DNA; so far, there have been very few studies of those genes. Therefore, we carried out a detailed study involving gene expression and genetic association studies of genes related to diverse mitochondrial functions. For gene expression analysis, postmortem brain tissues (anterior cingulate gyrus (ACG), motor cortex (MC) and thalamus (THL)) from autism patients (n=8) and controls (n=10) were obtained from the Autism Tissue Program (Princeton, NJ, USA). Quantitative real-time PCR arrays were used to quantify the expression of 84 genes related to diverse functions of mitochondria, including biogenesis, transport, translocation and apoptosis. We used the delta delta Ct (∆∆Ct) method for quantification of gene expression. DNA samples from 841 Caucasian and 188 Japanese families were used in the association study of genes selected from the gene expression analysis. FBAT was used to examine genetic association with autism. Several genes showed brain region-specific expression alterations in autism patients compared to controls. Metaxin 2 (MTX2), neurofilament, light polypeptide (NEFL) and solute carrier family 25, member 27 (SLC25A27) showed consistently reduced expression in the ACG, MC and THL of autism patients. NEFL (P = 0.038; Z-score 2.066) and SLC25A27 (P = 0.046; Z-score 1.990) showed genetic association with autism in Caucasian and Japanese samples, respectively. The expression of DNAJC19, DNM1L, LRPPRC

  17. Brain region-specific altered expression and association of mitochondria-related genes in autism

    Directory of Open Access Journals (Sweden)

    Anitha Ayyappan

    2012-11-01

    Full Text Available Abstract Background Mitochondrial dysfunction (MtD has been observed in approximately five percent of children with autism spectrum disorders (ASD. MtD could impair highly energy-dependent processes such as neurodevelopment, thereby contributing to autism. Most of the previous studies of MtD in autism have been restricted to the biomarkers of energy metabolism, while most of the genetic studies have been based on mutations in the mitochondrial DNA (mtDNA. Despite the mtDNA, most of the proteins essential for mitochondrial replication and function are encoded by the genomic DNA; so far, there have been very few studies of those genes. Therefore, we carried out a detailed study involving gene expression and genetic association studies of genes related to diverse mitochondrial functions. Methods For gene expression analysis, postmortem brain tissues (anterior cingulate gyrus (ACG, motor cortex (MC and thalamus (THL from autism patients (n=8 and controls (n=10 were obtained from the Autism Tissue Program (Princeton, NJ, USA. Quantitative real-time PCR arrays were used to quantify the expression of 84 genes related to diverse functions of mitochondria, including biogenesis, transport, translocation and apoptosis. We used the delta delta Ct (∆∆Ct method for quantification of gene expression. DNA samples from 841 Caucasian and 188 Japanese families were used in the association study of genes selected from the gene expression analysis. FBAT was used to examine genetic association with autism. Results Several genes showed brain region-specific expression alterations in autism patients compared to controls. Metaxin 2 (MTX2, neurofilament, light polypeptide (NEFL and solute carrier family 25, member 27 (SLC25A27 showed consistently reduced expression in the ACG, MC and THL of autism patients. NEFL (P = 0.038; Z-score 2.066 and SLC25A27 (P = 0.046; Z-score 1.990 showed genetic association with autism in Caucasian and Japanese samples, respectively. The

  18. Mitochondria-targeted cationic porphyrin-triphenylamine hybrids for enhanced two-photon photodynamic therapy.

    Science.gov (United States)

    Hammerer, Fabien; Poyer, Florent; Fourmois, Laura; Chen, Su; Garcia, Guillaume; Teulade-Fichou, Marie-Paule; Maillard, Philippe; Mahuteau-Betzer, Florence

    2018-01-01

    The proof of concept for two-photon activated photodynamic therapy has already been achieved for cancer treatment but the efficiency of this approach still heavily relies on the availability of photosensitizers combining high two-photon absorption and biocompatibility. In this line we recently reported on a series of porphyrin-triphenylamine hybrids which exhibit high singlet oxygen production quantum yield as well as high two-photon absorption cross-sections but with a very poor cellular internalization. We present herein new photosensitizers of the same porphyrin-triphenylamine hybrid series but bearing cationic charges which led to strongly enhanced water solubility and thus cellular penetration. In addition the new compounds have been found localized in mitochondria that are preferential target organelles for photodynamic therapy. Altogether the strongly improved properties of the new series combined with their specific mitochondrial localization lead to a significantly enhanced two-photon activated photodynamic therapy efficiency. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Mitochondria as key targets of cardioprotection in cardiac ischemic disease: role of thyroid hormone triiodothyronine.

    Science.gov (United States)

    Forini, Francesca; Nicolini, Giuseppina; Iervasi, Giorgio

    2015-03-19

    Ischemic heart disease is the major cause of mortality and morbidity worldwide. Early reperfusion after acute myocardial ischemia has reduced short-term mortality, but it is also responsible for additional myocardial damage, which in the long run favors adverse cardiac remodeling and heart failure evolution. A growing body of experimental and clinical evidence show that the mitochondrion is an essential end effector of ischemia/ reperfusion injury and a major trigger of cell death in the acute ischemic phase (up to 48-72 h after the insult), the subacute phase (from 72 h to 7-10 days) and chronic stage (from 10-14 days to one month after the insult). As such, in recent years scientific efforts have focused on mitochondria as a target for cardioprotective strategies in ischemic heart disease and cardiomyopathy. The present review discusses recent advances in this field, with special emphasis on the emerging role of the biologically active thyroid hormone triiodothyronine (T3).

  20. Altered Mitochondria, Protein Synthesis Machinery, and Purine Metabolism Are Molecular Contributors to the Pathogenesis of Creutzfeldt-Jakob Disease.

    Science.gov (United States)

    Ansoleaga, Belén; Garcia-Esparcia, Paula; Llorens, Franc; Hernández-Ortega, Karina; Carmona Tech, Margarita; Antonio Del Rio, José; Zerr, Inga; Ferrer, Isidro

    2016-06-12

    Neuron loss, synaptic decline, and spongiform change are the hallmarks of sporadic Creutzfeldt-Jakob disease (sCJD), and may be related to deficiencies in mitochondria, energy metabolism, and protein synthesis. To investigate these relationships, we determined the expression levels of genes encoding subunits of the 5 protein complexes of the electron transport chain, proteins involved in energy metabolism, nucleolar and ribosomal proteins, and enzymes of purine metabolism in frontal cortex samples from 15 cases of sCJD MM1 and age-matched controls. We also assessed the protein expression levels of subunits of the respiratory chain, initiation and elongation translation factors of protein synthesis, and localization of selected mitochondrial components. We identified marked, generalized alterations of mRNA and protein expression of most subunits of all 5 mitochondrial respiratory chain complexes in sCJD cases. Expression of molecules involved in protein synthesis and purine metabolism were also altered in sCJD. These findings point to altered mRNA and protein expression of components of mitochondria, protein synthesis machinery, and purine metabolism as components of the pathogenesis of CJD. © 2016 American Association of Neuropathologists, Inc. All rights reserved.

  1. Mitochondria-targeted molecules determine the redness of the zebra finch bill.

    Science.gov (United States)

    Cantarero, Alejandro; Alonso-Alvarez, Carlos

    2017-10-01

    The evolution and production mechanisms of red carotenoid-based ornaments in animals are poorly understood. Recently, it has been suggested that enzymes transforming yellow carotenoids to red pigments (ketolases) in animal cells may be positioned in the inner mitochondrial membrane (IMM) intimately linked to the electron transport chain. These enzymes may mostly synthesize coenzyme Q 10 (coQ 10 ), a key redox-cycler antioxidant molecularly similar to yellow carotenoids. It has been hypothesized that this shared pathway favours the evolution of red traits as sexually selected individual quality indices by revealing a well-adjusted oxidative metabolism. We administered mitochondria-targeted molecules to male zebra finches ( Taeniopygia guttata ) measuring their bill redness, a trait produced by transforming yellow carotenoids. One molecule included coQ 10 (mitoquinone mesylate, MitoQ) and the other one (decyl-triphenylphosphonium; dTPP) has the same structure without the coQ 10 aromatic ring. At the highest dose, the bill colour of MitoQ and dTPP birds strongly differed: MitoQ birds' bills were redder and dTPP birds showed paler bills even compared to birds injected with saline only. These results suggest that ketolases are indeed placed at the IMM and that coQ 10 antioxidant properties may improve their efficiency. The implications for evolutionary theories of sexual signalling are discussed. © 2017 The Author(s).

  2. Mitochondria as Key Targets of Cardioprotection in Cardiac Ischemic Disease: Role of Thyroid Hormone Triiodothyronine

    Directory of Open Access Journals (Sweden)

    Francesca Forini

    2015-03-01

    Full Text Available Ischemic heart disease is the major cause of mortality and morbidity worldwide. Early reperfusion after acute myocardial ischemia has reduced short-term mortality, but it is also responsible for additional myocardial damage, which in the long run favors adverse cardiac remodeling and heart failure evolution. A growing body of experimental and clinical evidence show that the mitochondrion is an essential end effector of ischemia/ reperfusion injury and a major trigger of cell death in the acute ischemic phase (up to 48–72 h after the insult, the subacute phase (from 72 h to 7–10 days and chronic stage (from 10–14 days to one month after the insult. As such, in recent years scientific efforts have focused on mitochondria as a target for cardioprotective strategies in ischemic heart disease and cardiomyopathy. The present review discusses recent advances in this field, with special emphasis on the emerging role of the biologically active thyroid hormone triiodothyronine (T3.

  3. Mitochondria-targeted antioxidant SkQ1 improves impaired dermal wound healing in old mice.

    Science.gov (United States)

    Demyanenko, Ilya A; Popova, Ekaterina N; Zakharova, Vlada V; Ilyinskaya, Olga P; Vasilieva, Tamara V; Romashchenko, Valeria P; Fedorov, Artem V; Manskikh, Vasily N; Skulachev, Maxim V; Zinovkin, Roman A; Pletjushkina, Olga Yu; Skulachev, Vladimir P; Chernyak, Boris V

    2015-07-01

    The process of skin wound healing is delayed or impaired in aging animals. To investigate the possible role of mitochondrial reactive oxygen species (mtROS) in cutaneous wound healing of aged mice, we have applied the mitochondria-targeted antioxidant SkQ1. The SkQ1 treatment resulted in accelerated resolution of the inflammatory phase, formation of granulation tissue, vascularization and epithelization of the wounds. The wounds of SkQ1-treated mice contained increased amount of myofibroblasts which produce extracellular matrix proteins and growth factors mediating granulation tissue formation. This effect resembled SkQ1-induced differentiation of fibroblasts to myofibroblast, observed earlierin vitro. The Transforming Growth Factor beta (TGFb) produced by SkQ1-treated fibroblasts was found to stimulated motility of endothelial cells in vitro, an effect which may underlie pro-angiogenic action of SkQ1 in the wounds. In vitro experiments showed that SkQ1 prevented decomposition of VE-cadherin containing contacts and following increase in permeability of endothelial cells monolayer, induced by pro-inflammatory cytokine TNF. Prevention of excessive reaction of endothelium to the pro-inflammatory cytokine(s) might account for anti-inflammatory effect of SkQ1. Our findings point to an important role of mtROS in pathogenesis of age-related chronic wounds.

  4. Mitochondria as a source and target of lipid peroxidation products in healthy and diseased heart.

    Science.gov (United States)

    Anderson, Ethan J; Katunga, Lalage A; Willis, Monte S

    2012-02-01

    The heart is a highly oxidative organ in which cardiomyocyte turnover is virtually absent, making it particularly vulnerable to accumulation of lipid peroxidation products (LPP) formed as a result of oxidative damage. Reactive oxygen and nitrogen species are the most common electrophiles formed during lipid peroxidation and lead to the formation of both stable and unstable LPP. Of the LPP formed, highly reactive aldehydes are a well-recognized causative factor in ageing and age-associated diseases, including cardiovascular disease and diabetes. Recent studies have identified that the mitochondria are both a primary source and target of LPP, with specific emphasis on aldehydes in cardiomyocytes and how these affect the electron transport system and Ca(2+) balance. Numerous studies have found that there are functional consequences in the heart following exposure to specific aldehydes (acrolein, trans-2-hexanal, 4-hydroxynonenal and acetaldehyde). Because these LPP are known to form in heart failure, cardiac ischaemia-reperfusion injury and diabetes, they may have an underappreciated role in the pathophysiology of these disease processes. Lipid peroxidation products are involved in the transcriptional regulation of endogenous anti-oxidant systems. Recent evidence demonstrates that transient increases in LPP may be beneficial in cardioprotection by contributing to mitohormesis (i.e. induction of anti-oxidant systems) in cardiomyocytes. Thus, exploitation of the cardioprotective actions of the LPP may represent a novel therapeutic strategy for future treatment of heart disease. © 2011 The Authors. Clinical and Experimental Pharmacology and Physiology © 2011 Blackwell Publishing Asia Pty Ltd.

  5. Pantothenate kinase-associated neurodegeneration: altered mitochondria membrane potential and defective respiration in Pank2 knock-out mouse model.

    Science.gov (United States)

    Brunetti, Dario; Dusi, Sabrina; Morbin, Michela; Uggetti, Andrea; Moda, Fabio; D'Amato, Ilaria; Giordano, Carla; d'Amati, Giulia; Cozzi, Anna; Levi, Sonia; Hayflick, Susan; Tiranti, Valeria

    2012-12-15

    Neurodegeneration with brain iron accumulation (NBIA) comprises a group of neurodegenerative disorders characterized by high brain content of iron and presence of axonal spheroids. Mutations in the PANK2 gene, which encodes pantothenate kinase 2, underlie an autosomal recessive inborn error of coenzyme A metabolism, called pantothenate kinase-associated neurodegeneration (PKAN). PKAN is characterized by dystonia, dysarthria, rigidity and pigmentary retinal degeneration. The pathogenesis of this disorder is poorly understood and, although PANK2 is a mitochondrial protein, perturbations in mitochondrial bioenergetics have not been reported. A knock-out (KO) mouse model of PKAN exhibits retinal degeneration and azoospermia, but lacks any neurological phenotype. The absence of a clinical phenotype has partially been explained by the different cellular localization of the human and murine PANK2 proteins. Here we demonstrate that the mouse Pank2 protein localizes to mitochondria, similar to its human orthologue. Moreover, we show that Pank2-defective neurons derived from KO mice have an altered mitochondrial membrane potential, a defect further corroborated by the observations of swollen mitochondria at the ultra-structural level and by the presence of defective respiration.

  6. ONC201 kills breast cancer cells in vitro by targeting mitochondria.

    Science.gov (United States)

    Greer, Yoshimi Endo; Porat-Shliom, Natalie; Nagashima, Kunio; Stuelten, Christina; Crooks, Dan; Koparde, Vishal N; Gilbert, Samuel F; Islam, Celia; Ubaldini, Ashley; Ji, Yun; Gattinoni, Luca; Soheilian, Ferri; Wang, Xiantao; Hafner, Markus; Shetty, Jyoti; Tran, Bao; Jailwala, Parthav; Cam, Maggie; Lang, Martin; Voeller, Donna; Reinhold, William C; Rajapakse, Vinodh; Pommier, Yves; Weigert, Roberto; Linehan, W Marston; Lipkowitz, Stanley

    2018-04-06

    We report a novel mechanism of action of ONC201 as a mitochondria-targeting drug in cancer cells. ONC201 was originally identified as a small molecule that induces transcription of TNF-related apoptosis-inducing ligand (TRAIL) and subsequently kills cancer cells by activating TRAIL death receptors. In this study, we examined ONC201 toxicity on multiple human breast and endometrial cancer cell lines. ONC201 attenuated cell viability in all cancer cell lines tested. Unexpectedly, ONC201 toxicity was not dependent on either TRAIL receptors nor caspases. Time-lapse live cell imaging revealed that ONC201 induces cell membrane ballooning followed by rupture, distinct from the morphology of cells undergoing apoptosis. Further investigation found that ONC201 induces phosphorylation of AMP-dependent kinase and ATP loss. Cytotoxicity and ATP depletion were significantly enhanced in the absence of glucose, suggesting that ONC201 targets mitochondrial respiration. Further analysis indicated that ONC201 indirectly inhibits mitochondrial respiration. Confocal and electron microscopic analysis demonstrated that ONC201 triggers mitochondrial structural damage and functional impairment. Moreover, ONC201 decreased mitochondrial DNA (mtDNA). RNAseq analysis revealed that ONC201 suppresses expression of multiple mtDNA-encoded genes and nuclear-encoded mitochondrial genes involved in oxidative phosphorylation and other mitochondrial functions. Importantly, fumarate hydratase deficient cancer cells and multiple cancer cell lines with reduced amounts of mtDNA were resistant to ONC201. These results indicate that cells not dependent on mitochondrial respiration are ONC201-resistant. Our data demonstrate that ONC201 kills cancer cells by disrupting mitochondrial function and further suggests that cancer cells that are dependent on glycolysis will be resistant to ONC201.

  7. Identification of functionally important amino acid residues in the mitochondria targeting sequence of Hepatitis B virus X protein

    International Nuclear Information System (INIS)

    Li, Sai Kam; Ho, Sai Fan; Tsui, Kwok Wing; Fung, Kwok Pui; Waye, M.Y. Mary

    2008-01-01

    Chronic hepatitis B virus (HBV) infection has been strongly associated with hepatocellular carcinoma (HCC) and the X protein (HBx) is thought to mediate the cellular changes associated with carcinogenesis. Recently, isolation of the hepatitis B virus integrants from HCC tissue by others have established the fact that the X gene is often truncated at its C-terminus. Expression of the GFP fusion proteins of HBx and its truncation mutants with a GFP tag in human liver cell-lines in this study revealed that the C-terminus of HBx is indispensable for its specific localization in the mitochondria. A crucial region of seven amino acids at the C-terminus has been mapped out in which the cysteine residue at position 115 serves as the most important residue for the subcellular localization. When cysteine 115 of HBx is mutated to alanine the mitochondria targeting property of HBx is abrogated

  8. Polyhydroxybutyrate Targets Mammalian Mitochondria and Increases Permeability of Plasmalemmal and Mitochondrial Membranes

    Science.gov (United States)

    Elustondo, Pia A.; Angelova, Plamena R.; Kawalec, Michał; Michalak, Michał; Kurcok, Piotr; Abramov, Andrey Y.; Pavlov, Evgeny V.

    2013-01-01

    Poly(3-hydroxybutyrate) (PHB) is a polyester of 3-hydroxybutyric acid (HB) that is ubiquitously present in all organisms. In higher eukaryotes PHB is found in the length of 10 to 100 HB units and can be present in free form as well as in association with proteins and inorganic polyphosphate. It has been proposed that PHB can mediate ion transport across lipid bilayer membranes. We investigated the ability of PHB to interact with living cells and isolated mitochondria and the effects of these interactions on membrane ion transport. We performed experiments using a fluorescein derivative of PHB (fluo-PHB). We found that fluo-PHB preferentially accumulated inside the mitochondria of HeLa cells. Accumulation of fluo-PHB induced mitochondrial membrane depolarization. This membrane depolarization was significantly delayed by the inhibitor of the mitochondrial permeability transition pore - Cyclosporin A. Further experiments using intact cells as well as isolated mitochondria confirmed that the effects of PHB directly linked to its ability to facilitate ion transport, including calcium, across the membranes. We conclude that PHB demonstrates ionophoretic properties in biological membranes and this effect is most profound in mitochondria due to the selective accumulation of the polymer in this organelle. PMID:24086638

  9. An off-on fluorescence probe targeting mitochondria based on oxidation-reduction response for tumor cell and tissue imaging

    Science.gov (United States)

    Yao, Hanchun; Cao, Li; Zhao, Weiwei; Zhang, Suge; Zeng, Man; Du, Bin

    2017-10-01

    In this study, a tumor-targeting poly( d, l-lactic-co-glycolic acid) (PLGA) loaded "off-on" fluorescent probe nanoparticle (PFN) delivery system was developed to evaluate the region of tumor by off-on fluorescence. The biodegradability of the nanosize PFN delivery system readily released the probe under tumor acidic conditions. The probe with good biocompatibility was used to monitor the intracellular glutathione (GSH) of cancer cells and selectively localize to mitochondria for tumor imaging. The incorporated tumor-targeting probe was based on the molecular photoinduced electron transfer (PET) mechanism preventing fluorescence ("off" state) and could be easily released under tumor acidic conditions. However, the released tumor-targeting fluorescence probe molecule was selective towards GSH with high selectivity and an ultra-sensitivity for the mitochondria of cancer cells and tissues significantly increasing the probe molecule fluorescence signal ("on" state). The tumor-targeting fluorescence probe showed sensitivity to GSH avoiding interference from cysteine and homocysteine. The PFNs could enable fluorescence-guided cancer imaging during cancer therapy. This work may expand the biological applications of PFNs as a diagnostic reagent, which will be beneficial for fundamental research in tumor imaging. [Figure not available: see fulltext.

  10. Oxidative Stress and Mitochondrial Dysfunction across Broad-Ranging Pathologies: Toward Mitochondria-Targeted Clinical Strategies

    OpenAIRE

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

    2014-01-01

    Beyond the disorders recognized as mitochondrial diseases, abnormalities in function and/or ultrastructure of mitochondria have been reported in several unrelated pathologies. These encompass ageing, malformations, and a number of genetic or acquired diseases, as diabetes and cardiologic, haematologic, organ-specific (e.g., eye or liver), neurologic and psychiatric, autoimmune, and dermatologic disorders. The mechanistic grounds for mitochondrial dysfunction (MDF) along with the occurrence of...

  11. Design of mitochondria-targeted colorimetric and ratiometric fluorescent probes for rapid detection of SO2 derivatives in living cells

    Science.gov (United States)

    Yang, Yutao; Zhou, Tingting; Bai, Bozan; Yin, Caixia; Xu, Wenzhi; Li, Wei

    2018-05-01

    Two mitochondria-targeted colorimetric and ratiometric fluorescent probes for SO2 derivatives were constructed based on the SO2 derivatives-triggered Michael addition reaction. The probes exhibit high specificity toward HSO3-/SO32- by interrupting their conjugation system resulting in a large ratiometric blue shift of 46-121 nm in their emission spectrum. The two well-resolved emission bands can ensure accurate detection of HSO3-. The detection limits were calculated to be 1.09 and 1.35 μM. Importantly, probe 1 and probe 2 were successfully used to fluorescence ratiometric imaging of endogenous HSO3- in BT-474 cells.

  12. Ambient particulate air pollution induces oxidative stress and alterations of mitochondria and gene expression in brown and white adipose tissues

    Directory of Open Access Journals (Sweden)

    Harkema Jack R

    2011-07-01

    Full Text Available Abstract Background Prior studies have demonstrated a link between air pollution and metabolic diseases such as type II diabetes. Changes in adipose tissue and its mitochondrial content/function are closely associated with the development of insulin resistance and attendant metabolic complications. We investigated changes in adipose tissue structure and function in brown and white adipose depots in response to chronic ambient air pollutant exposure in a rodent model. Methods Male ApoE knockout (ApoE-/- mice inhaled concentrated fine ambient PM (PM 2.5 or filtered air (FA for 6 hours/day, 5 days/week, for 2 months. We examined superoxide production by dihydroethidium staining; inflammatory responses by immunohistochemistry; and changes in white and brown adipocyte-specific gene profiles by real-time PCR and mitochondria by transmission electron microscopy in response to PM2.5 exposure in different adipose depots of ApoE-/- mice to understand responses to chronic inhalational stimuli. Results Exposure to PM2.5 induced an increase in the production of reactive oxygen species (ROS in brown adipose depots. Additionally, exposure to PM2.5 decreased expression of uncoupling protein 1 in brown adipose tissue as measured by immunohistochemistry and Western blot. Mitochondrial number was significantly reduced in white (WAT and brown adipose tissues (BAT, while mitochondrial size was also reduced in BAT. In BAT, PM2.5 exposure down-regulated brown adipocyte-specific genes, while white adipocyte-specific genes were differentially up-regulated. Conclusions PM2.5 exposure triggers oxidative stress in BAT, and results in key alterations in mitochondrial gene expression and mitochondrial alterations that are pronounced in BAT. We postulate that exposure to PM2.5 may induce imbalance between white and brown adipose tissue functionality and thereby predispose to metabolic dysfunction.

  13. Reactive Oxygen Species and the Aging Eye: Specific Role of Metabolically Active Mitochondria in Maintaining Lens Function and in the Initiation of the Oxidation-Induced Maturity Onset Cataract--A Novel Platform of Mitochondria-Targeted Antioxidants With Broad Therapeutic Potential for Redox Regulation and Detoxification of Oxidants in Eye Diseases.

    Science.gov (United States)

    Babizhayev, Mark A; Yegorov, Yegor E

    2016-01-01

    The aging eye appears to be at considerable risk from oxidative stress. A great deal of research indicates that dysfunctional mitochondria are the primary site of reactive oxygen species (ROS). More than 95% of O2 produced during normal metabolism is generated by the electron transport chain in the inner mitochondrial membrane. Mitochondria are also the major target of ROS. Cataract formation, the opacification of the eye lens, is one of the leading causes of human blindness worldwide, accounting for 47.8% of all causes of blindness. Cataracts result from the deposition of aggregated proteins in the eye lens and lens fiber cell plasma membrane damage, which causes clouding of the lens, light scattering, and obstruction of vision. ROS-induced damage in the lens cell may consist of oxidation of proteins, DNA damage, and/or lipid peroxidation, all of which have been implicated in cataractogenesis. This article is an attempt to integrate how mitochondrial ROS are altered in the aging eye along with those protective and repair therapeutic systems believed to regulate ROS levels in ocular tissues and how damage to these systems contributes to age-onset eye disease and cataract formation. Mitochondria-targeted antioxidants might be used to effectively prevent ROS-induced oxidation of lipids and proteins in the inner mitochondrial membrane in vivo. As a result of the combination of weak metal chelating, OH and lipid peroxyl radicals scavenging, reducing activities to liberated fatty acid, and phospholipid hydroperoxides, carnosine and carcinine appear to be physiological antioxidants able to efficiently protect the lipid phase of biologic membranes and aqueous environments and act as the antiapoptotic natural drug compounds The authors developed and patented the new ophthalmic compositions, including N-acetylcarnosine, acting as a prodrug of naturally targeted to mitochondria L-carnosine endowed with pluripotent antioxidant activities combined with mitochondria-targeted

  14. Mitochondria-targeted antioxidant mitoquinone deactivates human and rat hepatic stellate cells and reduces portal hypertension in cirrhotic rats.

    Science.gov (United States)

    Vilaseca, Marina; García-Calderó, Héctor; Lafoz, Erica; Ruart, Maria; López-Sanjurjo, Cristina Isabel; Murphy, Michael P; Deulofeu, Ramon; Bosch, Jaume; Hernández-Gea, Virginia; Gracia-Sancho, Jordi; García-Pagán, Juan Carlos

    2017-07-01

    In cirrhosis, activated hepatic stellate cells (HSC) play a major role in increasing intrahepatic vascular resistance and developing portal hypertension. We have shown that cirrhotic livers have increased reactive oxygen species (ROS), and that antioxidant therapy decreases portal pressure. Considering that mitochondria produce many of these ROS, our aim was to assess the effects of the oral mitochondria-targeted antioxidant mitoquinone on hepatic oxidative stress, HSC phenotype, liver fibrosis and portal hypertension. Ex vivo: Hepatic stellate cells phenotype was analysed in human precision-cut liver slices in response to mitoquinone or vehicle. In vitro: Mitochondrial oxidative stress was analysed in different cell type of livers from control and cirrhotic rats. HSC phenotype, proliferation and viability were assessed in LX2, and in primary human and rat HSC treated with mitoquinone or vehicle. In vivo: CCl 4 - and thioacetamide-cirrhotic rats were treated with mitoquinone (5 mg/kg/day) or the vehicle compound, DecylTPP, for 2 weeks, followed by measurement of oxidative stress, systemic and hepatic haemodynamic, liver fibrosis, HSC phenotype and liver inflammation. Mitoquinone deactivated human and rat HSC, decreased their proliferation but with no effects on viability. In CCl 4 -cirrhotic rats, mitoquinone decreased hepatic oxidative stress, improved HSC phenotype, reduced intrahepatic vascular resistance and diminished liver fibrosis. These effects were associated with a significant reduction in portal pressure without changes in arterial pressure. These results were further confirmed in the thioacetamide-cirrhotic model. We propose mitochondria-targeted antioxidants as a novel treatment approach against portal hypertension and cirrhosis. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  15. Mitochondrial bioenergetics during the initiation of mercuric chloride-induced renal activity. II. Functional alterations of renal cortical mitochondria isolated after mercuric chloride treatment

    Energy Technology Data Exchange (ETDEWEB)

    Weinberg, J.M. (Veterans Administration Medical Center, Ann Arbor, MI); Harding, P.G.; Humes, H.D.

    1982-01-01

    The mitochondrial functional defects occurring in the early stages of nephrotoxic renal injury secondary to mercuric chloride have been characterized. No loss of cellular integrity or major mitochondrial structural alterations occurred within the first 3 hr after a subcutaneous injection of 5 mg/kg of HgCl/sub 2/. At 3 h, levels of Hg/sup 2 +/ in renal cortex and isolated renal cortical mitochondria were 1.87 and 0.72 nmol/mg of protein, respectively. Much evidence suggested that this Hg/sup 2 +/ had reached the mitochondria in situ and not during the isolation process. Mitochondria isolated beginning 1 h after treatment with HgCl/sub 2/ showed depressed ADP uptake. At 2 h, inhibitions of State 3 and 2,4-dinitrophenol uncoupled respiration were detected. Inhibition of 2,4-dinitrophenol-activated mitochondrial ATPase activity was present when measured on mitochondria isolated at 3 h. These effects were not reversed by 2 mM dithioerythritol, 50 mg/ml of albumin or 5 mM MgCl/sub 2/. Analysis of the data in the context of information available on the in vitro effects of HgCl/sub 2/ (Weinberg, J.M., Harding, P.G., and Humes, H.D. (1982) J. Biol. Chem. 257, 60-67) indicated that the mitochondrial functional effects could not be attributed to interaction of the mitochondria with Hg/sup 2 +/ during their isolation. These studies implicate compromised mitochondrial bioenergetic function as one of the earliest intracellular effects of Hg/sup 2 +/ in the production of nephrotoxicity but suggest that the intracellular process involves events in addition to those seen with direct exposure of mitochondria to Hg/sup 2 +/ in vitro.

  16. Shikonin Directly Targets Mitochondria and Causes Mitochondrial Dysfunction in Cancer Cells

    Directory of Open Access Journals (Sweden)

    Benjamin Wiench

    2012-01-01

    Full Text Available Chemotherapy is a mainstay of cancer treatment. Due to increased drug resistance and the severe side effects of currently used therapeutics, new candidate compounds are required for improvement of therapy success. Shikonin, a natural naphthoquinone, was used in traditional Chinese medicine for the treatment of different inflammatory diseases and recent studies revealed the anticancer activities of shikonin. We found that shikonin has strong cytotoxic effects on 15 cancer cell lines, including multidrug-resistant cell lines. Transcriptome-wide mRNA expression studies showed that shikonin induced genetic pathways regulating cell cycle, mitochondrial function, levels of reactive oxygen species, and cytoskeletal formation. Taking advantage of the inherent fluorescence of shikonin, we analyzed its uptake and distribution in live cells with high spatial and temporal resolution using flow cytometry and confocal microscopy. Shikonin was specifically accumulated in the mitochondria, and this accumulation was associated with a shikonin-dependent deregulation of cellular Ca2+ and ROS levels. This deregulation led to a breakdown of the mitochondrial membrane potential, dysfunction of microtubules, cell-cycle arrest, and ultimately induction of apoptosis. Seeing as both the metabolism and the structure of mitochondria show marked differences between cancer cells and normal cells, shikonin is a promising candidate for the next generation of chemotherapy.

  17. Mitochondria-Targeted Nitroxide, Mito-CP, Suppresses Medullary Thyroid Carcinoma Cell Survival In Vitro and In Vivo

    Science.gov (United States)

    Starenki, Dmytro

    2013-01-01

    Context: Medullary thyroid carcinoma (MTC) is a neuroendocrine tumor mainly caused by mutations in the RET proto-oncogene. For MTC therapy, the U.S. Food and Drug Administration recently approved vandetanib and cabozantinib, multikinase inhibitors targeting RET and other tyrosine kinase receptors of vascular endothelial growth factor, epidermal growth factor, or hepatocyte growth factor. Nevertheless, not all patients with the progressive MTC respond to these drugs, requiring the development of additional therapeutic modalities that have distinct activity. Objective: We aimed to evaluate mitochondria-targeted carboxy-proxyl (Mito-CP), a mitochondria-targeted redox-sensitive agent, for its tumor-suppressive efficacy against MTC. Design: In vitro cultures of 2 human MTC cell lines, TT and MZ-CRC-1, and TT xenografts in mice were treated with Mito-CP in comparison with vandetanib. The effects on cell survival/death, RET expression, mitochondrial integrity, and oxidative stress were determined. Results: Contrary to vandetanib, Mito-CP induced RET downregulation and strong cytotoxic effects in both cell lines in vitro, including caspase-dependent apoptosis. These effects were accompanied by mitochondrial membrane depolarization, decreased oxygen consumption, and increased oxidative stress in cells. Intriguingly, Mito-CP–induced cell death, but not RET downregulation, was partially inhibited by the reactive oxygen species scavenger, N-acetyl-cysteine, indicating that Mito-CP mediates tumor-suppressive effects via redox-dependent as well as redox-independent mechanisms. Orally administered Mito-CP effectively suppressed TT xenografts in mice, with an efficacy comparable to vandetanib and relatively low toxicity to animals. Conclusion: Our results suggest that Mito-CP can effectively suppress MTC cell growth/survival via a mechanism distinct from vandetanib effects. Mitochondrial targeting may be a potential strategy for MTC therapy. PMID:23509102

  18. Derivatives of Rhodamine 19 as Mild Mitochondria-targeted Cationic Uncouplers*

    Science.gov (United States)

    Antonenko, Yuri N.; Avetisyan, Armine V.; Cherepanov, Dmitry A.; Knorre, Dmitry A.; Korshunova, Galina A.; Markova, Olga V.; Ojovan, Silvia M.; Perevoshchikova, Irina V.; Pustovidko, Antonina V.; Rokitskaya, Tatyana I.; Severina, Inna I.; Simonyan, Ruben A.; Smirnova, Ekaterina A.; Sobko, Alexander A.; Sumbatyan, Natalia V.; Severin, Fedor F.; Skulachev, Vladimir P.

    2011-01-01

    A limited decrease in mitochondrial membrane potential can be beneficial for cells, especially under some pathological conditions, suggesting that mild uncouplers (protonophores) causing such an effect are promising candidates for therapeutic uses. The great majority of protonophores are weak acids capable of permeating across membranes in their neutral and anionic forms. In the present study, protonophorous activity of a series of derivatives of cationic rhodamine 19, including dodecylrhodamine (C12R1) and its conjugate with plastoquinone (SkQR1), was revealed using a variety of assays. Derivatives of rhodamine B, lacking dissociable protons, showed no protonophorous properties. In planar bilayer lipid membranes, separating two compartments differing in pH, diffusion potential of H+ ions was generated in the presence of C12R1 and SkQR1. These compounds induced pH equilibration in liposomes loaded with the pH probe pyranine. C12R1 and SkQR1 partially stimulated respiration of rat liver mitochondria in State 4 and decreased their membrane potential. Also, C12R1 partially stimulated respiration of yeast cells but, unlike the anionic protonophore FCCP, did not suppress their growth. Loss of function of mitochondrial DNA in yeast (grande-petite transformation) is known to cause a major decrease in the mitochondrial membrane potential. We found that petite yeast cells are relatively more sensitive to the anionic uncouplers than to C12R1 compared with grande cells. Together, our data suggest that rhodamine 19-based cationic protonophores are self-limiting; their uncoupling activity is maximal at high membrane potential, but the activity decreases membrane potentials, which causes partial efflux of the uncouplers from mitochondria and, hence, prevents further membrane potential decrease. PMID:21454507

  19. Synergistic Protective Effects of Mitochondrial Division Inhibitor 1 and Mitochondria-Targeted Small Peptide SS31 in Alzheimer's Disease.

    Science.gov (United States)

    Reddy, P Hemachandra; Manczak, Maria; Yin, XiangLing; Reddy, Arubala P

    2018-01-01

    The purpose of our study was to determine the synergistic protective effects of mitochondria-targeted antioxidant SS31 and mitochondria division inhibitor 1 (Mdivi1) in Alzheimer's disease (AD). Using biochemical methods, we assessed mitochondrial function by measuring the levels of hydrogen peroxide, lipid peroxidation, cytochrome c oxidase activity, mitochondrial ATP, and GTPase Drp1 enzymatic activity in mutant AβPP cells. Using biochemical methods, we also measured cell survival and apoptotic cell death. Amyloid-β (Aβ) levels were measured using sandwich ELISA, and using real-time quantitative RT-PCR, we assessed mtDNA (mtDNA) copy number in relation to nuclear DNA (nDNA) in all groups of cells. We found significantly reduced levels of Aβ40 and Aβ42 in mutant AβPP cells treated with SS31, Mdivi1, and SS31+Mdivi1, and the reduction of Aβ42 levels were much higher in SS31+Mdivi1 treated cells than individual treatments of SS31 and Mdivi1. The levels of mtDNA copy number and cell survival were significantly increased in SS31, Mdivi1, and SS31+Mdivi1 treated mutant AβPP cells; however, the increased levels of mtDNA copy number and cell survival were much higher in SS31+Mdivi1 treated cells than individual treatments of SS31 and Mdivi1. Mitochondrial dysfunction is significantly reduced in SS31, Mdivi1, and SS31+Mdivi1 treated mutant AβPP cells; however, the reduction is much higher in cells treated with both SS31+Mdvi1. Similarly, GTPase Drp1 activity is reduced in all treatments, but reduced much higher in SS31+Mdivi1 treated cells. These observations strongly suggest that combined treatment of SS31+Mdivi1 is effective than individual treatments of SS31 and Mdivi1. Therefore, we propose that combined treatment of SS31+Mdivi1 is a better therapeutic strategy for AD. Ours is the first study to investigate combined treatment of mitochondria-targeted antioxidant SS31 and mitochondrial division inhibitor 1 in AD neurons.

  20. Designing inhibitors of cytochrome c/cardiolipin peroxidase complexes: mitochondria-targeted imidazole-substituted fatty acids.

    Science.gov (United States)

    Jiang, Jianfei; Bakan, Ahmet; Kapralov, Alexandr A; Silva, K Ishara; Huang, Zhentai; Amoscato, Andrew A; Peterson, James; Garapati, Venkata Krishna; Saxena, Sunil; Bayir, Hülya; Atkinson, Jeffrey; Bahar, Ivet; Kagan, Valerian E

    2014-06-01

    Mitochondria have emerged as the major regulatory platform responsible for the coordination of numerous metabolic reactions as well as cell death processes, whereby the execution of intrinsic apoptosis includes the production of reactive oxygen species fueling oxidation of cardiolipin (CL) catalyzed by cytochrome (Cyt) c. As this oxidation occurs within the peroxidase complex of Cyt c with CL, the latter represents a promising target for the discovery and design of drugs with antiapoptotic mechanisms of action. In this work, we designed and synthesized a new group of mitochondria-targeted imidazole-substituted analogs of stearic acid TPP-n-ISAs with various positions of the attached imidazole group on the fatty acid (n = 6, 8, 10, 13, and 14). By using a combination of absorption spectroscopy and EPR protocols (continuous wave electron paramagnetic resonance and electron spin echo envelope modulation) we demonstrated that TPP-n-ISAs indeed were able to potently suppress CL-induced structural rearrangements in Cyt c, paving the way to its peroxidase competence. TPP-n-ISA analogs preserved the low-spin hexa-coordinated heme-iron state in Cyt c/CL complexes whereby TPP-6-ISA displayed a significantly more effective preservation pattern than TPP-14-ISA. Elucidation of these intermolecular stabilization mechanisms of Cyt c identified TPP-6-ISA as an effective inhibitor of the peroxidase function of Cyt c/CL complexes with a significant antiapoptotic potential realized in mouse embryonic cells exposed to ionizing irradiation. These experimental findings were detailed and supported by all-atom molecular dynamics simulations. Based on the experimental data and computation predictions, we identified TPP-6-ISA as a candidate drug with optimized antiapoptotic potency. Copyright © 2014 Elsevier Inc. All rights reserved.

  1. Zinc and calcium alter the relationship between mitochondrial respiration, ROS and membrane potential in rainbow trout (Oncorhynchus mykiss) liver mitochondria.

    Science.gov (United States)

    Sharaf, Mahmoud S; Stevens, Don; Kamunde, Collins

    2017-08-01

    At excess levels, zinc (Zn) disrupts mitochondrial functional integrity and induces oxidative stress in aquatic organisms. Although much is known about the modulation of Zn toxicity by calcium (Ca) in fish, their interactions at the mitochondrial level have scarcely been investigated. Here we assessed the individual and combined effects of Zn and Ca on the relationship between mitochondrial respiration, ROS and membrane potential (ΔΨ mt ) in rainbow trout liver mitochondria. We tested if cation uptake through the mitochondrial calcium uniporter (MCU) is a prerequisite for Zn- and/or Ca-induced alteration of mitochondrial function. Furthermore, using our recently developed real-time multi-parametric method, we investigated the changes in respiration, ΔΨ mt , and reactive oxygen species (ROS, as hydrogen peroxide (H 2 O 2 )) release associated with Ca-induced mitochondrial depolarization imposed by transient and permanent openings of the mitochondrial permeability transition pore (mPTP). We found that independent of the MCU, Zn precipitated an immediate depolarization of the ΔΨ mt that was associated with relatively slow enhancement of H 2 O 2 release, inhibition of respiration and reversal of the positive correlation between ROS and ΔΨ mt . In contrast, an equitoxic dose of Ca caused transient depolarization, and stimulation of both respiration and H 2 O 2 release, effects that were completely abolished when the MCU was blocked. Contrary to our expectation that mitochondrial transition ROS Spike (mTRS) would be sensitive to both Zn and Ca, only Ca suppressed it. Moreover, Zn and Ca in combination immediately depolarized the ΔΨ mt , and caused transient and sustained stimulation of respiration and H 2 O 2 release, respectively. Lastly, we uncovered and characterized an mPTP-independent Ca-induced depolarization spike that was associated with exposure to moderately elevated levels of Ca. Importantly, we showed the stimulation of ROS release associated with

  2. Brain mitochondria as a primary target in the development of treatment strategies for Alzheimer disease.

    Science.gov (United States)

    Aliev, Gjumrakch; Palacios, Hector H; Walrafen, Brianna; Lipsitt, Amanda E; Obrenovich, Mark E; Morales, Ludis

    2009-10-01

    Alzheimer's disease (AD) and cerebrovascular accidents are two leading causes of age-related dementia. Increasing evidence supports the idea that chronic hypoperfusion is primarily responsible for the pathogenesis that underlies both disease processes. In this regard, hypoperfusion appears to induce oxidative stress (OS), which is largely due to reactive oxygen species (ROS), and over time initiates mitochondrial failure which is known as an initiating factor of AD. Recent evidence indicates that chronic injury stimulus induces hypoperfusion seen in vulnerable brain regions. This reduced regional cerebral blood flow (CBF) then leads to energy failure within the vascular endothelium and associated brain parenchyma, manifested by damaged mitochondrial ultrastructure (the formation of large number of immature, electron-dense "hypoxic" mitochondria) and by overproduction of mitochondrial DNA (mtDNA) deletions. Additionally, these mitochondrial abnormalities co-exist with increased redox metal activity, lipid peroxidation, and RNA oxidation. Interestingly, vulnerable neurons and glial cells show mtDNA deletions and oxidative stress markers only in the regions that are closely associated with damaged vessels, and, moreover, brain vascular wall lesions linearly correlate with the degree of neuronal and glial cell damage. We summarize the large body of evidence which indicates that sporadic, late-onset AD results from a vascular etiology by briefly reviewing mitochondrial damage and vascular risk factors associated with the disease and then we discuss the cerebral microvascular changes reason for the energy failure that occurs in normal aging and, to a much greater extent, AD.

  3. Oxidative Stress and Mitochondrial Dysfunction across Broad-Ranging Pathologies: Toward Mitochondria-Targeted Clinical Strategies

    Directory of Open Access Journals (Sweden)

    Giovanni Pagano

    2014-01-01

    Full Text Available Beyond the disorders recognized as mitochondrial diseases, abnormalities in function and/or ultrastructure of mitochondria have been reported in several unrelated pathologies. These encompass ageing, malformations, and a number of genetic or acquired diseases, as diabetes and cardiologic, haematologic, organ-specific (e.g., eye or liver, neurologic and psychiatric, autoimmune, and dermatologic disorders. The mechanistic grounds for mitochondrial dysfunction (MDF along with the occurrence of oxidative stress (OS have been investigated within the pathogenesis of individual disorders or in groups of interrelated disorders. We attempt to review broad-ranging pathologies that involve mitochondrial-specific deficiencies or rely on cytosol-derived prooxidant states or on autoimmune-induced mitochondrial damage. The established knowledge in these subjects warrants studies aimed at elucidating several open questions that are highlighted in the present review. The relevance of OS and MDF in different pathologies may establish the grounds for chemoprevention trials aimed at compensating OS/MDF by means of antioxidants and mitochondrial nutrients.

  4. Mitochondria-Targeted Antioxidant SS31 Prevents Amyloid Beta-Induced Mitochondrial Abnormalities and Synaptic Degeneration in Alzheimer’s Disease

    Directory of Open Access Journals (Sweden)

    Marcus J. Calkins

    2012-10-01

    Full Text Available In neuronal systems, the health and activity of mitochondria and synapses are tightly coupled. For this reason, it has been postulated that mitochondrial abnormalities may, at least in part, drive neurodegeneration in conditions such as Alzheimer’s disease (AD. Mounting evidence from multiple Alzheimer’s disease cell and mouse models and postmortem brains suggest that loss of mitochondrial integrity may be a key factor that mediates synaptic loss. Therefore, the prevention or rescue of mitochondrial dysfunction may help delay or altogether prevent AD-associated neurodegeneration. Since mitochondrial health is heavily dependent on antioxidant defenses, researchers have begun to explore the use of mitochondria-targeted antioxidants as therapeutic tools to prevent neurodegenerative diseases. This review will highlight advances made using a model mitochondria-targeted antioxidant peptide, SS31, as a potential treatment for AD.

  5. The mitochondria-targeted antioxidants and remote kidney preconditioning ameliorate brain damage through kidney-to-brain cross-talk.

    Directory of Open Access Journals (Sweden)

    Denis N Silachev

    Full Text Available BACKGROUND: Many ischemia-induced neurological pathologies including stroke are associated with high oxidative stress. Mitochondria-targeted antioxidants could rescue the ischemic organ by providing specific delivery of antioxidant molecules to the mitochondrion, which potentially suffers from oxidative stress more than non-mitochondrial cellular compartments. Besides direct antioxidative activity, these compounds are believed to activate numerous protective pathways. Endogenous anti-ischemic defense may involve the very powerful neuroprotective agent erythropoietin, which is mainly produced by the kidney in a redox-dependent manner, indicating an important role of the kidney in regulation of brain ischemic damage. The goal of this study is to track the relations between the kidney and the brain in terms of the amplification of defense mechanisms during SkQR1 treatment and remote renal preconditioning and provide evidence that the kidney can generate signals inducing a tolerance to oxidative stress-associated brain pathologies. METHODOLOGY/PRINCIPAL FINDINGS: We used the cationic plastoquinone derivative, SkQR1, as a mitochondria-targeted antioxidant to alleviate the deleterious consequences of stroke. A single injection of SkQR1 before cerebral ischemia in a dose-dependent manner reduces infarction and improves functional recovery. Concomitantly, an increase in the levels of erythropoietin in urine and phosphorylated glycogen synthase kinase-3β (GSK-3β in the brain was detected 24 h after SkQR1 injection. However, protective effects of SkQR1 were not observed in rats with bilateral nephrectomy and in those treated with the nephrotoxic antibiotic gentamicin, indicating the protective role of humoral factor(s which are released from functional kidneys. Renal preconditioning also induced brain protection in rats accompanied by an increased erythropoietin level in urine and kidney tissue and P-GSK-3β in brain. Co-cultivation of SkQR1-treated

  6. The mitochondria-targeted antioxidants and remote kidney preconditioning ameliorate brain damage through kidney-to-brain cross-talk.

    Science.gov (United States)

    Silachev, Denis N; Isaev, Nikolay K; Pevzner, Irina B; Zorova, Ljubava D; Stelmashook, Elena V; Novikova, Svetlana V; Plotnikov, Egor Y; Skulachev, Vladimir P; Zorov, Dmitry B

    2012-01-01

    Many ischemia-induced neurological pathologies including stroke are associated with high oxidative stress. Mitochondria-targeted antioxidants could rescue the ischemic organ by providing specific delivery of antioxidant molecules to the mitochondrion, which potentially suffers from oxidative stress more than non-mitochondrial cellular compartments. Besides direct antioxidative activity, these compounds are believed to activate numerous protective pathways. Endogenous anti-ischemic defense may involve the very powerful neuroprotective agent erythropoietin, which is mainly produced by the kidney in a redox-dependent manner, indicating an important role of the kidney in regulation of brain ischemic damage. The goal of this study is to track the relations between the kidney and the brain in terms of the amplification of defense mechanisms during SkQR1 treatment and remote renal preconditioning and provide evidence that the kidney can generate signals inducing a tolerance to oxidative stress-associated brain pathologies. We used the cationic plastoquinone derivative, SkQR1, as a mitochondria-targeted antioxidant to alleviate the deleterious consequences of stroke. A single injection of SkQR1 before cerebral ischemia in a dose-dependent manner reduces infarction and improves functional recovery. Concomitantly, an increase in the levels of erythropoietin in urine and phosphorylated glycogen synthase kinase-3β (GSK-3β) in the brain was detected 24 h after SkQR1 injection. However, protective effects of SkQR1 were not observed in rats with bilateral nephrectomy and in those treated with the nephrotoxic antibiotic gentamicin, indicating the protective role of humoral factor(s) which are released from functional kidneys. Renal preconditioning also induced brain protection in rats accompanied by an increased erythropoietin level in urine and kidney tissue and P-GSK-3β in brain. Co-cultivation of SkQR1-treated kidney cells with cortical neurons resulted in enchanced

  7. Neuroprotection and Anti-Epileptogenesis with a Mitochondria-Targeted Antioxidant

    Science.gov (United States)

    2013-12-01

    antiepiletogenic properties of a mitochondrial-targeted antioxidant, SS-31 using the pilocarpine (Pilo) model of status epilepticus (SE), the kindling seizure...project. Aim #1 – Test the neuroprotective and anticonvulsant properties of SS-31 in the pilocarpine model of status epilepticus (SE) in the rat. In this...quantity of drug. KEY RESEARCH ACCOMPLISHMENTS:  Treatment with SS-31 did not delay the onset of status epilepticus in the pilocarpine model  SS

  8. Structural Insights into the Molecular Design of Flutolanil Derivatives Targeted for Fumarate Respiration of Parasite Mitochondria

    Directory of Open Access Journals (Sweden)

    Daniel Ken Inaoka

    2015-07-01

    Full Text Available Recent studies on the respiratory chain of Ascaris suum showed that the mitochondrial NADH-fumarate reductase system composed of complex I, rhodoquinone and complex II plays an important role in the anaerobic energy metabolism of adult A. suum. The system is the major pathway of energy metabolism for adaptation to a hypoxic environment not only in parasitic organisms, but also in some types of human cancer cells. Thus, enzymes of the pathway are potential targets for chemotherapy. We found that flutolanil is an excellent inhibitor for A. suum complex II (IC50 = 0.058 μM but less effectively inhibits homologous porcine complex II (IC50 = 45.9 μM. In order to account for the specificity of flutolanil to A. suum complex II from the standpoint of structural biology, we determined the crystal structures of A. suum and porcine complex IIs binding flutolanil and its derivative compounds. The structures clearly demonstrated key interactions responsible for its high specificity to A. suum complex II and enabled us to find analogue compounds, which surpass flutolanil in both potency and specificity to A. suum complex II. Structures of complex IIs binding these compounds will be helpful to accelerate structure-based drug design targeted for complex IIs.

  9. Structural Insights into the Molecular Design of Flutolanil Derivatives Targeted for Fumarate Respiration of Parasite Mitochondria.

    Science.gov (United States)

    Inaoka, Daniel Ken; Shiba, Tomoo; Sato, Dan; Balogun, Emmanuel Oluwadare; Sasaki, Tsuyoshi; Nagahama, Madoka; Oda, Masatsugu; Matsuoka, Shigeru; Ohmori, Junko; Honma, Teruki; Inoue, Masayuki; Kita, Kiyoshi; Harada, Shigeharu

    2015-07-07

    Recent studies on the respiratory chain of Ascaris suum showed that the mitochondrial NADH-fumarate reductase system composed of complex I, rhodoquinone and complex II plays an important role in the anaerobic energy metabolism of adult A. suum. The system is the major pathway of energy metabolism for adaptation to a hypoxic environment not only in parasitic organisms, but also in some types of human cancer cells. Thus, enzymes of the pathway are potential targets for chemotherapy. We found that flutolanil is an excellent inhibitor for A. suum complex II (IC50 = 0.058 μM) but less effectively inhibits homologous porcine complex II (IC50 = 45.9 μM). In order to account for the specificity of flutolanil to A. suum complex II from the standpoint of structural biology, we determined the crystal structures of A. suum and porcine complex IIs binding flutolanil and its derivative compounds. The structures clearly demonstrated key interactions responsible for its high specificity to A. suum complex II and enabled us to find analogue compounds, which surpass flutolanil in both potency and specificity to A. suum complex II. Structures of complex IIs binding these compounds will be helpful to accelerate structure-based drug design targeted for complex IIs.

  10. Respiration and nitrogen assimilation: targeting mitochondria-associated metabolism as a means to enhance nitrogen use efficiency.

    Science.gov (United States)

    Foyer, Christine H; Noctor, Graham; Hodges, Michael

    2011-02-01

    Considerable advances in our understanding of the control of mitochondrial metabolism and its interactions with nitrogen metabolism and associated carbon/nitrogen interactions have occurred in recent years, particularly highlighting important roles in cellular redox homeostasis. The tricarboxylic acid (TCA) cycle is a central metabolic hub for the interacting pathways of respiration, nitrogen assimilation, and photorespiration, with components that show considerable flexibility in relation to adaptations to the different functions of mitochondria in photosynthetic and non-photosynthetic cells. By comparison, the operation of the oxidative pentose phosphate pathway appears to represent a significant limitation to nitrogen assimilation in non-photosynthetic tissues. Valuable new insights have been gained concerning the roles of the different enzymes involved in the production of 2-oxoglutarate (2-OG) for ammonia assimilation, yielding an improved understanding of the crucial role of cellular energy balance as a broker of co-ordinate regulation. Taken together with new information on the mechanisms that co-ordinate the expression of genes involved in organellar functions, including energy metabolism, and the potential for exploiting the existing flexibility for NAD(P)H utilization in the respiratory electron transport chain to drive nitrogen assimilation, the evidence that mitochondrial metabolism and machinery are potential novel targets for the enhancement of nitrogen use efficiency (NUE) is explored.

  11. Protective Effect of a Mitochondria-Targeted Peptide against the Development of Chemotherapy-Induced Peripheral Neuropathy in Mice.

    Science.gov (United States)

    Toyama, Satoshi; Shimoyama, Naohito; Szeto, Hazel H; Schiller, Peter W; Shimoyama, Megumi

    2018-04-18

    Several chemotherapeutic agents used for cancer treatment induce dose-limiting peripheral neuropathy that compromises patients' quality of life and limits cancer treatment. Recently, mitochondrial dysfunction has been shown to be involved in the mechanism of chemotherapy-induced peripheral neuropathy. SS-20 is a mitochondria-targeted peptide that promotes mitochondrial respiration and restores mitochondrial bioenergetics. In the present study, we examined the protective effect of SS-20 against the development of chemotherapy-induced peripheral neuropathy utilizing a murine model of peripheral neuropathy induced by oxaliplatin, a first-line chemotherapy agent for colon cancer. Weekly administrations of oxaliplatin induced peripheral neuropathy as demonstrated by the development of neuropathic pain and loss of intraepidermal nerve fibers in the hind paw. Continuous administration of SS-20 protected against the development of oxaliplatin-induced neuropathic pain and mitigated the loss of intraepidermal nerve fibers to normal levels. Our findings suggest that SS-20 may be a drug candidate for the prevention of chemotherapy-induced peripheral neuropathy.

  12. Mitochondria-targeting cyclometalated iridium(III)-PEG complexes with tunable photodynamic activity.

    Science.gov (United States)

    Li, Steve Po-Yam; Lau, Chris Tsan-Shing; Louie, Man-Wai; Lam, Yun-Wah; Cheng, Shuk Han; Lo, Kenneth Kam-Wing

    2013-10-01

    We present a new class of phosphorescent cyclometalated iridium(III) polypyridine poly(ethylene glycol) (PEG) complexes [Ir(N(^)C)2(bpy-CONH-PEG)](PF6) (bpy-CONH-PEG = 4-(N-(2-(ω-methoxypoly-(1-oxapropyl))ethyl)aminocarbonyl)-4'-methyl-2,2'-bipyridine, number average molecular weight (Mn) = 5272.23, weight average molecular weight (Mw) = 5317.38, polydispersity index (PDI) = 1.009; HN(^)C = 2-phenylpyridine, Hppy (1a), 2-((1,1'-biphenyl)-4-yl)pyridine, Hpppy (2a), 2-phenylquinoline, Hpq (3a), 2-phenylbenzothiazole, Hbt (4a), 2-(1-naphthyl)benzothiazole, Hbsn (5a)). The photophysical, photochemical, and biological properties of these complexes have been compared with those of their PEG-free counterparts [Ir(N(^)C)2(bpy-CONH-Et)](PF6) (bpy-CONH-Et = 4-(N-ethylaminocarbonyl)-4'-methyl-2,2'-bipyridine; HN(^)C = Hppy (1b), Hpppy (2b), Hpq (3b), Hbt (4b), Hbsn (5b)). Upon irradiation, all the complexes exhibited intense and long-lived green to orange-red emission under ambient conditions. The emission was phosphorescence in nature and can be quenched by O2 with the generation of singlet oxygen ((1)O2). The quantum yields for (1)O2 production of the complexes in aerated DMSO (0.24-0.83) were found to be dependent on the excited-state lifetimes of the complexes, which can be altered using different cyclometalating ligands (N(^)C). Cell-based assays indicated that the PEG complexes were noncytotoxic in the dark (IC50 > 300 μM); however, most of them became significantly cytotoxic upon irradiation (IC50 = 3.4 - 23.2 μM). Laser-scanning confocal microscopy images revealed localization of complex 3a in the mitochondrial region of HeLa cells and the induction of rapid necrotic cell death upon light activation. Additionally, the lack of dark toxicity and potential application of the PEG complexes as a visualizing reagent have been demonstrated using zebrafish (Danio rerio) as an animal model. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Abnormal Mitochondrial Dynamics and Synaptic Degeneration as Early Events in Alzheimer’s Disease: Implications to Mitochondria-Targeted Antioxidant Therapeutics

    Science.gov (United States)

    Reddy, P. Hemachandra; Tripathy, Raghav; Troung, Quang; Thirumala, Karuna; Reddy, Tejaswini P.; Anekonda, Vishwanath; Shirendeb, Ulziibat P.; Calkins, Marcus J.; Reddy, Arubala P.; Mao, Peizhong; Manczak, Maria

    2011-01-01

    Synaptic pathology and mitochondrial oxidative damage are early events in Alzheimer’s disease (AD) progression. Loss of synapses and synaptic damage are the best correlate of cognitive deficits found in AD patients. Recent research on amyloid bet (Aβ) and mitochondria in AD revealed that Aβ accumulates in synapses and synaptic mitochondria, leading to abnormal mitochondrial dynamics and synaptic degeneration in AD neurons. Further, recent studies using live-cell imaging and primary neurons from amyloid beta precursor protein (AβPP) transgenic mice revealed that reduced mitochondrial mass, defective axonal transport of mitochondria and synaptic degeneration, indicating that Aβ is responsible for mitochondrial and synaptic deficiencies. Tremendous progress has been made in studying antioxidant approaches in mouse models of AD and clinical trials of AD patients. This article highlights the recent developments made in Aβ-induced abnormal mitochondrial dynamics, defective mitochondrial biogenesis, impaired axonal transport and synaptic deficiencies in AD. This article also focuses on mitochondrial approaches in treating AD, and also discusses latest research on mitochondria-targeted antioxidants in AD. PMID:22037588

  14. Mitochondria in Lung Diseases

    Science.gov (United States)

    Aravamudan, Bharathi; Thompson, Michael A.; Pabelick, Christina M.; Prakash, Y. S.

    2014-01-01

    Summary Mitochondria are autonomous cellular organelles that oversee a variety of functions such as metabolism, energy production, calcium buffering, and cell fate determination. Regulation of their morphology and diverse activities beyond energy production are being recognized as playing major roles in cellular health and dysfunction. This review is aimed at summarizing what is known regarding mitochondrial contributions to pathogenesis of lung diseases. Emphasis is given to understanding the importance of structural and functional aspects of mitochondria in both normal cellular function (based on knowledge from other cell types) and in development and modulation of lung diseases such as asthma, COPD, cystic fibrosis and cancer. Emerging techniques that allow examination of mitochondria, and potential strategies to target mitochondria in the treatment of lung diseases are also discussed. PMID:23978003

  15. Antioxidant mechanism of mitochondria-targeted plastoquinone SkQ1 is suppressed in aglycemic HepG2 cells dependent on oxidative phosphorylation

    Czech Academy of Sciences Publication Activity Database

    Ježek, J.; Engstová, Hana; Ježek, Petr

    2017-01-01

    Roč. 1858, č. 9 (2017), s. 750-762 ISSN 0005-2728 R&D Projects: GA ČR(CZ) GA17-01813S Institutional support: RVO:67985823 Keywords : mitochondria-targeted antioxidant SkQ1 * mitochondrial Complex I superoxide formation * mitochondrial Complex III superoxide formation * HepG2 cell s * NAD(P)H fluorescence lifetime imaging microscopy Subject RIV: ED - Physiology OBOR OECD: Cell biology Impact factor: 4.932, year: 2016

  16. Mitochondria-Targeted Antioxidants SkQ1 and MitoTEMPO Failed to Exert a Long-Term Beneficial Effect in Murine Polymicrobial Sepsis

    Directory of Open Access Journals (Sweden)

    Pia Rademann

    2017-01-01

    Full Text Available Mitochondrial-derived reactive oxygen species have been deemed an important contributor in sepsis pathogenesis. We investigated whether two mitochondria-targeted antioxidants (mtAOX; SkQ1 and MitoTEMPO improved long-term outcome, lessened inflammation, and improved organ homeostasis in polymicrobial murine sepsis. 3-month-old female CD-1 mice (n=90 underwent cecal ligation and puncture (CLP and received SkQ1 (5 nmol/kg, MitoTEMPO (50 nmol/kg, or vehicle 5 times post-CLP. Separately, 52 SkQ1-treated CLP mice were sacrificed at 24 h and 48 h for additional endpoints. Neither MitoTEMPO nor SkQ1 exerted any protracted survival benefit. Conversely, SkQ1 exacerbated 28-day mortality by 29%. CLP induced release of 10 circulating cytokines, increased urea, ALT, and LDH, and decreased glucose but irrespectively of treatment. Similar occurred for CLP-induced lymphopenia/neutrophilia and the NO blood release. At 48 h post-CLP, dying mice had approximately 100-fold more CFUs in the spleen than survivors, but this was not SkQ1 related. At 48 h, macrophage and granulocyte counts increased in the peritoneal lavage but irrespectively of SkQ1. Similarly, hepatic mitophagy was not altered by SkQ1 at 24 h. The absence of survival benefit of mtAOX may be due to the extended treatment and/or a relatively moderate-risk-of-death CLP cohort. Long-term effect of mtAOX in abdominal sepsis appears different to sepsis/inflammation models arising from other body compartments.

  17. Genetic inactivation of mitochondria-targeted redox enzyme p66ShcA preserves neuronal viability and mitochondrial integrity in response to oxidative challenges

    Directory of Open Access Journals (Sweden)

    Michael eForte

    2012-07-01

    Full Text Available Mitochondria are essential to neuronal viability and function due to their roles in ATP production, intracellular calcium regulation, and activation of apoptotic pathways. Accordingly, mitochondrial dysfunction has been indicated in a wide variety of neurodegenerative diseases, including Alzheimer’s disease, Huntington’s disease, amyotrophic lateral sclerosis, stroke and multiple sclerosis (MS. Recent evidence points to the permeability transition pore (PTP as a key player in mitochondrial dysfunction in these diseases, in which pathologic opening leads to mitochondrial swelling, rupture, release of cytochrome c, and neuronal death. Reactive oxygen species (ROS, which are inducers of PTP opening, have been prominently implicated in the progression of many of these neurodegenerative diseases. In this context, inactivation of a mitochondria-targeted redox enzyme p66ShcA (p66 has been recently shown to prevent the neuronal cell death leading to axonal severing in the murine model of MS, experimental autoimmune encephalomyelitis (EAE. To further characterize the response of neurons lacking p66, we assessed their reaction to treatment with oxidative stressors implicated in neurodegenerative pathways. Specifically, p66-knockout (p66-KO and wild-type (WT neurons were treated with hydrogen peroxide (H2O2 and nitric oxide (NO, and assessed for cell viability and changes in mitochondrial properties, including morphology and ROS production. The results showed that p66-KO neurons had greater survival following treatment with oxidative stressors and generated less ROS when compared to WT neurons. Correspondingly, mitochondria in p66-KO neurons showed diminished morphological changes in response to these challenges. Overall, these findings highlight the importance of developing mitochondria-targeted therapeutics for neurodegenerative disorders, and emphasize p66, mitochondrial ROS, and the PTP as key targets for maintaining mitochondrial and neuronal

  18. Dietary avocado oil supplementation attenuates the alterations induced by type I diabetes and oxidative stress in electron transfer at the complex II-complex III segment of the electron transport chain in rat kidney mitochondria.

    Science.gov (United States)

    Ortiz-Avila, Omar; Sámano-García, Carlos Alberto; Calderón-Cortés, Elizabeth; Pérez-Hernández, Ismael H; Mejía-Zepeda, Ricardo; Rodríguez-Orozco, Alain R; Saavedra-Molina, Alfredo; Cortés-Rojo, Christian

    2013-06-01

    Impaired complex III activity and reactive oxygen species (ROS) generation in mitochondria have been identified as key events leading to renal damage during diabetes. Due to its high content of oleic acid and antioxidants, we aimed to test whether avocado oil may attenuate the alterations in electron transfer at complex III induced by diabetes by a mechanism related with increased resistance to lipid peroxidation. 90 days of avocado oil administration prevented the impairment in succinate-cytochrome c oxidoreductase activity caused by streptozotocin-induced diabetes in kidney mitochondria. This was associated with a protection against decreased electron transfer through high potential chain in complex III related to cytochromes c + c1 loss. During Fe(2+)-induced oxidative stress, avocado oil improved the activities of complexes II and III and enhanced the protection conferred by a lipophilic antioxidant against damage by Fe(2+). Avocado oil also decreased ROS generation in Fe(2+)-damaged mitochondria. Alterations in the ratio of C20:4/C18:2 fatty acids were observed in mitochondria from diabetic animals that not were corrected by avocado oil treatment, which yielded lower peroxidizability indexes only in diabetic mitochondria although avocado oil caused an augment in the total content of monounsaturated fatty acids. Moreover, a protective effect of avocado oil against lipid peroxidation was observed consistently only in control mitochondria. Since the beneficial effects of avocado oil in diabetic mitochondria were not related to increased resistance to lipid peroxidation, these effects were discussed in terms of the antioxidant activity of both C18:1 and the carotenoids reported to be contained in avocado oil.

  19. Mitocans as anti-cancer agents targeting mitochondria: lessons from studies with vitamin E analogues, inhibitors of complex II

    Czech Academy of Sciences Publication Activity Database

    Neužil, Jiří; Dyason, J.C.; Freeman, R.; Dong, L.F.; Procházka, L.; Wang, X. F.; Scheffler, I.; Ralph, S.J.

    2007-01-01

    Roč. 39, č. 1 (2007), s. 65-72 ISSN 0145-479X Institutional research plan: CEZ:AV0Z50520701; CEZ:AV0Z50520514 Keywords : mitocans * mitochondria * complex II Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.634, year: 2007

  20. Novel mitochondria-targeted heat-soluble proteins identified in the anhydrobiotic Tardigrade improve osmotic tolerance of human cells.

    Directory of Open Access Journals (Sweden)

    Sae Tanaka

    Full Text Available Tardigrades are able to tolerate almost complete dehydration through transition to a metabolically inactive state, called "anhydrobiosis". Late Embryogenesis Abundant (LEA proteins are heat-soluble proteins involved in the desiccation tolerance of many anhydrobiotic organisms. Tardigrades, Ramazzottius varieornatus, however, express predominantly tardigrade-unique heat-soluble proteins: CAHS (Cytoplasmic Abundant Heat Soluble and SAHS (Secretory Abundant Heat Soluble proteins, which are secreted or localized in most intracellular compartments, except the mitochondria. Although mitochondrial integrity is crucial to ensure cellular survival, protective molecules for mitochondria have remained elusive. Here, we identified two novel mitochondrial heat-soluble proteins, RvLEAM and MAHS (Mitochondrial Abundant Heat Soluble, as potent mitochondrial protectants from Ramazzottius varieornatus. RvLEAM is a group3 LEA protein and immunohistochemistry confirmed its mitochondrial localization in tardigrade cells. MAHS-green fluorescent protein fusion protein localized in human mitochondria and was heat-soluble in vitro, though no sequence similarity with other known proteins was found, and one region was conserved among tardigrades. Furthermore, we demonstrated that RvLEAM protein as well as MAHS protein improved the hyperosmotic tolerance of human cells. The findings of the present study revealed that tardigrade mitochondria contain at least two types of heat-soluble proteins that might have protective roles in water-deficient environments.

  1. A novel CISD2 mutation associated with a classical Wolfram syndrome phenotype alters Ca2+ homeostasis and ER-mitochondria interactions.

    Science.gov (United States)

    Rouzier, Cécile; Moore, David; Delorme, Cécile; Lacas-Gervais, Sandra; Ait-El-Mkadem, Samira; Fragaki, Konstantina; Burté, Florence; Serre, Valérie; Bannwarth, Sylvie; Chaussenot, Annabelle; Catala, Martin; Yu-Wai-Man, Patrick; Paquis-Flucklinger, Véronique

    2017-05-01

    Wolfram syndrome (WS) is a progressive neurodegenerative disease characterized by early-onset optic atrophy and diabetes mellitus, which can be associated with more extensive central nervous system and endocrine complications. The majority of patients harbour pathogenic WFS1 mutations, but recessive mutations in a second gene, CISD2, have been described in a small number of families with Wolfram syndrome type 2 (WFS2). The defining diagnostic criteria for WFS2 also consist of optic atrophy and diabetes mellitus, but unlike WFS1, this phenotypic subgroup has been associated with peptic ulcer disease and an increased bleeding tendency. Here, we report on a novel homozygous CISD2 mutation (c.215A > G; p.Asn72Ser) in a Moroccan patient with an overlapping phenotype suggesting that Wolfram syndrome type 1 and type 2 form a continuous clinical spectrum with genetic heterogeneity. The present study provides strong evidence that this particular CISD2 mutation disturbs cellular Ca2+ homeostasis with enhanced Ca2+ flux from the ER to mitochondria and cytosolic Ca2+ abnormalities in patient-derived fibroblasts. This Ca2+ dysregulation was associated with increased ER-mitochondria contact, a swollen ER lumen and a hyperfused mitochondrial network in the absence of overt ER stress. Although there was no marked alteration in mitochondrial bioenergetics under basal conditions, culture of patient-derived fibroblasts in glucose-free galactose medium revealed a respiratory chain defect in complexes I and II, and a trend towards decreased ATP levels. Our results provide important novel insight into the potential disease mechanisms underlying the neurodegenerative consequences of CISD2 mutations and the subsequent development of multisystemic disease. © The Author 2017. Published by Oxford University Press.

  2. Melatonin, mitochondria and hypertension.

    Science.gov (United States)

    Baltatu, Ovidiu C; Amaral, Fernanda G; Campos, Luciana A; Cipolla-Neto, Jose

    2017-11-01

    Melatonin, due to its multiple means and mechanisms of action, plays a fundamental role in the regulation of the organismal physiology by fine tunning several functions. The cardiovascular system is an important site of action as melatonin regulates blood pressure both by central and peripheral interventions, in addition to its relation with the renin-angiotensin system. Besides, the systemic management of several processes, melatonin acts on mitochondria regulation to maintain a healthy cardiovascular system. Hypertension affects target organs in different ways and cellular energy metabolism is frequently involved due to mitochondrial alterations that include a rise in reactive oxygen species production and an ATP synthesis decrease. The discussion that follows shows the role played by melatonin in the regulation of mitochondrial physiology in several levels of the cardiovascular system, including brain, heart, kidney, blood vessels and, particularly, regulating the renin-angiotensin system. This discussion shows the putative importance of using melatonin as a therapeutic tool involving its antioxidant potential and its action on mitochondrial physiology in the cardiovascular system.

  3. Mitochondria-targeted superoxide dismutase (SOD2) regulates radiation resistance and radiation stress response in HeLa cells

    International Nuclear Information System (INIS)

    Hosoki, Ayaka; Yonekura, Shin-Ichiro; Zhao, Qing-Li

    2012-01-01

    Reactive oxygen species (ROS) act as a mediator of ionizing radiation-induced cellular damage. Previous studies have indicated that MnSOD (SOD2) plays a critical role in protection against ionizing radiation in mammalian cells. In this study, we constructed two types of stable HeLa cell lines overexpressing SOD2, HeLa S3/SOD2 and T-REx HeLa/SOD2, to elucidate the mechanisms underlying the protection against radiation by SOD2. SOD2 overexpression in mitochondria enhanced the survival of HeLa S3 and T-REx HeLa cells following γ-irradiation. The levels of γH2AX significantly decreased in HeLa S3/SOD2 and T-REx HeLa/SOD2 cells compared with those in the control cells. MitoSox TM Red assays showed that both lines of SOD2-expressing cells showed suppression of the superoxide generation in mitochondria. Furthermore, flow cytometry with a fluorescent probe (2',7'-dichlorofluorescein) revealed that the cellular levels of ROS increased in HeLa S3 cells during post-irradiation incubation, but the increase was markedly attenuated in HeLa S3/SOD2 cells. DNA microarray analysis revealed that, of 47,000 probe sets analyzed, 117 and 166 probes showed more than 2-fold changes after 5.5 Gy of γ-irradiation in control and HeLa S3/SOD2 cells, respectively. Pathway analysis revealed different expression profiles in irradiated control cells and irradiated SOD2-overexpressing cells. These results indicate that SOD2 protects HeLa cells against cellular effects of γ-rays through suppressing oxidative stress in irradiated cells caused by ROS generated in the mitochondria and through regulating the expression of genes which play a critical role in protection against ionizing radiation. (author)

  4. The Immature Fiber Mutant Phenotype of Cotton (Gossypium hirsutum Is Linked to a 22-bp Frame-Shift Deletion in a Mitochondria Targeted Pentatricopeptide Repeat Gene

    Directory of Open Access Journals (Sweden)

    Gregory N. Thyssen

    2016-06-01

    Full Text Available Cotton seed trichomes are the most important source of natural fibers globally. The major fiber thickness properties influence the price of the raw material, and the quality of the finished product. The recessive immature fiber (im gene reduces the degree of fiber cell wall thickening by a process that was previously shown to involve mitochondrial function in allotetraploid Gossypium hirsutum. Here, we present the fine genetic mapping of the im locus, gene expression analysis of annotated proteins near the locus, and association analysis of the linked markers. Mapping-by-sequencing identified a 22-bp deletion in a pentatricopeptide repeat (PPR gene that is completely linked to the immature fiber phenotype in 2837 F2 plants, and is absent from all 163 cultivated varieties tested, although other closely linked marker polymorphisms are prevalent in the diversity panel. This frame-shift mutation results in a transcript with two long open reading frames: one containing the N-terminal transit peptide that targets mitochondria, the other containing only the RNA-binding PPR domains, suggesting that a functional PPR protein cannot be targeted to mitochondria in the im mutant. Taken together, these results suggest that PPR gene Gh_A03G0489 is involved in the cotton fiber wall thickening process, and is a promising candidate gene at the im locus. Our findings expand our understanding of the molecular mechanisms that modulate cotton fiber fineness and maturity, and may facilitate the development of cotton varieties with superior fiber attributes.

  5. The Aging Mitochondria

    Directory of Open Access Journals (Sweden)

    Pierre Theurey

    2018-01-01

    Full Text Available Mitochondrial dysfunction is a central event in many pathologies and contributes as well to age-related processes. However, distinguishing between primary mitochondrial dysfunction driving aging and a secondary mitochondrial impairment resulting from other cell alterations remains challenging. Indeed, even though mitochondria undeniably play a crucial role in aging pathways at the cellular and organismal level, the original hypothesis in which mitochondrial dysfunction and production of free radicals represent the main driving force of cell degeneration has been strongly challenged. In this review, we will first describe mitochondrial dysfunctions observed in aged tissue, and how these features have been linked to mitochondrial reactive oxygen species (ROS–mediated cell damage and mitochondrial DNA (mtDNA mutations. We will also discuss the clues that led to consider mitochondria as the starting point in the aging process, and how recent research has showed that the mitochondria aging axis represents instead a more complex and multifactorial signaling pathway. New working hypothesis will be also presented in which mitochondria are considered at the center of a complex web of cell dysfunctions that eventually leads to cell senescence and death.

  6. Ampk phosphorylation of Ulk1 is required for targeting of mitochondria to lysosomes in exercise-induced mitophagy.

    Science.gov (United States)

    Laker, Rhianna C; Drake, Joshua C; Wilson, Rebecca J; Lira, Vitor A; Lewellen, Bevan M; Ryall, Karen A; Fisher, Carleigh C; Zhang, Mei; Saucerman, Jeffrey J; Goodyear, Laurie J; Kundu, Mondira; Yan, Zhen

    2017-09-15

    Mitochondrial health is critical for skeletal muscle function and is improved by exercise training through both mitochondrial biogenesis and removal of damaged/dysfunctional mitochondria via mitophagy. The mechanisms underlying exercise-induced mitophagy have not been fully elucidated. Here, we show that acute treadmill running in mice causes mitochondrial oxidative stress at 3-12 h and mitophagy at 6 h post-exercise in skeletal muscle. These changes were monitored using a novel fluorescent reporter gene, pMitoTimer, that allows assessment of mitochondrial oxidative stress and mitophagy in vivo, and were preceded by increased phosphorylation of AMP activated protein kinase (Ampk) at tyrosine 172 and of unc-51 like autophagy activating kinase 1 (Ulk1) at serine 555. Using mice expressing dominant negative and constitutively active Ampk in skeletal muscle, we demonstrate that Ulk1 activation is dependent on Ampk. Furthermore, exercise-induced metabolic adaptation requires Ulk1. These findings provide direct evidence of exercise-induced mitophagy and demonstrate the importance of Ampk-Ulk1 signaling in skeletal muscle.Exercise is associated with biogenesis and removal of dysfunctional mitochondria. Here the authors use a mitochondrial reporter gene to demonstrate the occurrence of mitophagy following exercise in mice, and show this is dependent on AMPK and ULK1 signaling.

  7. Chatty Mitochondria: Keeping Balance in Cellular Protein Homeostasis.

    Science.gov (United States)

    Topf, Ulrike; Wrobel, Lidia; Chacinska, Agnieszka

    2016-08-01

    Mitochondria are multifunctional cellular organelles that host many biochemical pathways including oxidative phosphorylation (OXPHOS). Defective mitochondria pose a threat to cellular homeostasis and compensatory responses exist to curtail the source of stress and/or its consequences. The mitochondrial proteome comprises proteins encoded by the nuclear and mitochondrial genomes. Disturbances in protein homeostasis may originate from mistargeting of nuclear encoded mitochondrial proteins. Defective protein import and accumulation of mistargeted proteins leads to stress that triggers translation alterations and proteasomal activation. These cytosolic pathways are complementary to the mitochondrial unfolded protein response (UPRmt) that aims to increase the capacity of protein quality control mechanisms inside mitochondria. They constitute putative targets for interventions aimed at increasing the fitness, stress resistance, and longevity of cells and organisms. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Mitochondria Targetable Time-Gated Luminescence Probe for Singlet Oxygen Based on a β-Diketonate-Europium Complex.

    Science.gov (United States)

    Sun, Jingyan; Song, Bo; Ye, Zhiqiang; Yuan, Jingli

    2015-12-21

    Singlet oxygen ((1)O2) plays a key role in the photodynamic therapy (PDT) technique of neoplastic diseases. In this work, by using a 9,10-dimethyl-2-anthryl-containing β-diketone, 1,1,1,2,2-pentafluoro-5-(9',10'-dimethyl-2'-anthryl)-3,5-pentanedione (Hpfdap), as a (1)O2-recognition ligand, a novel β-diketonate-europium(III) complex that can act as a luminescence probe for (1)O2, [Eu(pfdap)3(tpy)] (tpy = 2,2',2″-terpyridine), has been designed and synthesized for the time-gated luminescence detection of (1)O2 in living cells. The complex is weakly luminescent due to the quenching effect of 9,10-dimethyl-2-anthryl groups. After reaction with (1)O2, accompanied by the formation of endoperoxides of 9,10-dimethyl-2-anthryl groups, the luminescence quenching disappears, so that the long-lived luminescence of the europium(III) complex is switched on. The complex showed highly selective luminescence response to (1)O2 with a remarkable luminescence enhancement. Combined with the time-gated luminescence imaging technique, the complex was successfully used as a luminescent probe for the monitoring of the time-dependent generation of (1)O2 in 5-aminolevulinic acid (a PDT drug) loaded HepG2 cells during the photodynamic process. In addition, by coloading the complex and a mitochondrial indicator, Mito-Tracker Green, into HepG2 cells, the specific localization of [Eu(pfdap)3(tpy)] molecules in mitochondria of HepG2 cells was demonstrated by confocal fluorescence imaging measurements.

  9. Mitochondria-targeted plastoquinone derivatives as tools to interrupt execution of the aging program. 1. Cationic plastoquinone derivatives: synthesis and in vitro studies.

    Science.gov (United States)

    Antonenko, Y N; Avetisyan, A V; Bakeeva, L E; Chernyak, B V; Chertkov, V A; Domnina, L V; Ivanova, O Yu; Izyumov, D S; Khailova, L S; Klishin, S S; Korshunova, G A; Lyamzaev, K G; Muntyan, M S; Nepryakhina, O K; Pashkovskaya, A A; Pletjushkina, O Yu; Pustovidko, A V; Roginsky, V A; Rokitskaya, T I; Ruuge, E K; Saprunova, V B; Severina, I I; Simonyan, R A; Skulachev, I V; Skulachev, M V; Sumbatyan, N V; Sviryaeva, I V; Tashlitsky, V N; Vassiliev, J M; Vyssokikh, M Yu; Yaguzhinsky, L S; Zamyatnin, A A; Skulachev, V P

    2008-12-01

    concluded that SkQs are rechargeable, mitochondria-targeted antioxidants of very high efficiency and specificity. Therefore, they might be used to effectively prevent ROS-induced oxidation of lipids and proteins in the inner mitochondrial membrane in vivo.

  10. Mitochondria and lipid raft-located FOF1-ATP synthase as major therapeutic targets in the antileishmanial and anticancer activities of ether lipid edelfosine.

    Directory of Open Access Journals (Sweden)

    Janny A Villa-Pulgarín

    2017-08-01

    antileishmanial and anticancer actions of edelfosine share some common signaling processes, with mitochondria and raft-located FOF1-ATP synthase being critical in the killing process, thus identifying novel druggable targets for the treatment of leishmaniasis.

  11. Molecular networks related to the immune system and mitochondria are targets for the pesticide dieldrin in the zebrafish (Danio rerio) central nervous system.

    Science.gov (United States)

    Cowie, Andrew M; Sarty, Kathleena I; Mercer, Angella; Koh, Jin; Kidd, Karen A; Martyniuk, Christopher J

    2017-03-22

    The objectives of this study were to determine the behavioral and molecular responses in the adult zebrafish (Danio rerio) central nervous system (CNS) following a dietary exposure to the pesticide dieldrin. Zebrafish were fed pellets spiked with 0.03, 0.15, or 1.8μg/g dieldrin for 21days. Behavioral analysis revealed no difference in exploratory behaviors or those related to anxiety. Transcriptional networks for T-cell aggregation and selection were decreased in expression suggesting an immunosuppressive effect of dieldrin, consistent with other studies investigating organochlorine pesticides. Processes related to oxidative phosphorylation were also differentially affected by dieldrin. Quantitative proteomics (iTRAQ) using a hybrid quadrupole-Orbitrap identified 226 proteins that were different following one or more doses. These proteins included ATP synthase subunits (mitochondrial) and hypoxia up-regulated protein 1 which were decreased and NADH dehydrogenases (mitochondrial) and signal recognition particle 9 which were up-regulated. Thus, proteins affected were functionally associated with the mitochondria and a protein network analysis implicated Parkinson's disease (PD) and Huntington's disease as diseases associated with altered proteins. Molecular networks related to mitochondrial dysfunction and T-cell regulation are hypothesized to underlie the association between dieldrin and PD. These data contribute to a comprehensive transcriptomic and proteomic biomarker framework for pesticide exposures and neurodegenerative diseases. Dieldrin is a persistent organochlorine pesticide that has been associated with human neurodegenerative disease such as Parkinson's disease. Dieldrin is ranked 18th on the 2015 U.S. Agency for Toxic Substances and Disease Registry and continues to be a pesticide of concern for human health. Transcriptomics and quantitative proteomics (ITRAQ) were employed to characterize the molecular networks in the central nervous system that are

  12. Mitochondria and Endothelial Function

    Science.gov (United States)

    Kluge, Matthew A.; Fetterman, Jessica L.; Vita, Joseph A.

    2013-01-01

    In contrast to their role in other cell types with higher energy demands, mitochondria in endothelial cells primarily function in signaling cellular responses to environmental cues. This article provides an overview of key aspects of mitochondrial biology in endothelial cells, including subcellular location, biogenesis, dynamics, autophagy, ROS production and signaling, calcium homeostasis, regulated cell death, and heme biosynthesis. In each section, we introduce key concepts and then review studies showing the importance of that mechanism to endothelial control of vasomotor tone, angiogenesis, and inflammatory activation. We particularly highlight the small number of clinical and translational studies that have investigated each mechanism in human subjects. Finally, we review interventions that target different aspects of mitochondrial function and their effects on endothelial function. The ultimate goal of such research is the identification of new approaches for therapy. The reviewed studies make it clear that mitochondria are important in endothelial physiology and pathophysiology. A great deal of work will be needed, however, before mitochondria-directed therapies are available for the prevention and treatment of cardiovascular disease. PMID:23580773

  13. Experimental mitochondria-targeted DNA methylation identifies GpC methylation, not CpG methylation, as potential regulator of mitochondrial gene expression

    NARCIS (Netherlands)

    van der Wijst, Monique G. P.; van Tilburg, Amanda Y.; Ruiters, Marcel H. J.; Rots, Marianne G.

    2017-01-01

    Like the nucleus, mitochondria contain their own DNA and recent reports provide accumulating evidence that also the mitochondrial DNA (mtDNA) is subjective to DNA methylation. This evidence includes the demonstration of mitochondria-localised DNA methyltransferases and demethylases, and the

  14. Diabetes-Induced Dysfunction of Mitochondria and Stem Cells in Skeletal Muscle and the Nervous System

    Science.gov (United States)

    Fujimaki, Shin; Kuwabara, Tomoko

    2017-01-01

    Diabetes mellitus is one of the most common metabolic diseases spread all over the world, which results in hyperglycemia caused by the breakdown of insulin secretion or insulin action or both. Diabetes has been reported to disrupt the functions and dynamics of mitochondria, which play a fundamental role in regulating metabolic pathways and are crucial to maintain appropriate energy balance. Similar to mitochondria, the functions and the abilities of stem cells are attenuated under diabetic condition in several tissues. In recent years, several studies have suggested that the regulation of mitochondria functions and dynamics is critical for the precise differentiation of stem cells. Importantly, physical exercise is very useful for preventing the diabetic alteration by improving the functions of both mitochondria and stem cells. In the present review, we provide an overview of the diabetic alterations of mitochondria and stem cells and the preventive effects of physical exercise on diabetes, focused on skeletal muscle and the nervous system. We propose physical exercise as a countermeasure for the dysfunction of mitochondria and stem cells in several target tissues under diabetes complication and to improve the physiological function of patients with diabetes, resulting in their quality of life being maintained. PMID:29036909

  15. MicroRNA-145 protects cardiomyocytes against hydrogen peroxide (H₂O₂-induced apoptosis through targeting the mitochondria apoptotic pathway.

    Directory of Open Access Journals (Sweden)

    Ruotian Li

    Full Text Available MicroRNAs, a class of small and non-encoding RNAs that transcriptionally or post-transcriptionally modulate the expression of their target genes, has been implicated as critical regulatory molecules in many cardiovascular diseases, including ischemia/reperfusion induced cardiac injury. Here, we report microRNA-145, a tumor suppressor miRNA, can protect cardiomyocytes from hydrogen peroxide H₂O₂-induced apoptosis through targeting the mitochondrial pathway. Quantitative real-time PCR (qPCR demonstrated that the expression of miR-145 in either ischemia/reperfused mice myocardial tissues or H₂O₂-treated neonatal rat ventricle myocytes (NRVMs was markedly down-regulated. Over-expression of miR-145 significantly inhibited the H₂O₂-induced cellular apoptosis, ROS production, mitochondrial structure disruption as well as the activation of key signaling proteins in mitochondrial apoptotic pathway. These protective effects of miR-145 were abrogated by over-expression of Bnip3, an initiation factor of the mitochondrial apoptotic pathway in cardiomyocytes. Finally, we utilized both luciferase reporter assay and western blot analysis to identify Bnip3 as a direct target of miR-145. Our results suggest miR-145 plays an important role in regulating mitochondrial apoptotic pathway in heart challenged with oxidative stress. MiR-145 may represent a potential therapeutic target for treatment of oxidative stress-associated cardiovascular diseases, such as myocardial ischemia/reperfusion injury.

  16. Disruption of Mitochondria-Associated Endoplasmic Reticulum Membrane (MAM) Integrity Contributes to Muscle Insulin Resistance in Mice and Humans.

    Science.gov (United States)

    Tubbs, Emily; Chanon, Stéphanie; Robert, Maud; Bendridi, Nadia; Bidaux, Gabriel; Chauvin, Marie-Agnès; Ji-Cao, Jingwei; Durand, Christine; Gauvrit-Ramette, Daphné; Vidal, Hubert; Lefai, Etienne; Rieusset, Jennifer

    2018-04-01

    Modifications of the interactions between endoplasmic reticulum (ER) and mitochondria, defined as mitochondria-associated membranes (MAMs), were recently shown to be involved in the control of hepatic insulin action and glucose homeostasis, but with conflicting results. Whereas skeletal muscle is the primary site of insulin-mediated glucose uptake and the main target for alterations in insulin-resistant states, the relevance of MAM integrity in muscle insulin resistance is unknown. Deciphering the importance of MAMs on muscle insulin signaling could help to clarify this controversy. Here, we show in skeletal muscle of different mice models of obesity and type 2 diabetes (T2D) a marked disruption of ER-mitochondria interactions as an early event preceding mitochondrial dysfunction and insulin resistance. Furthermore, in human myotubes, palmitate-induced insulin resistance is associated with a reduction of structural and functional ER-mitochondria interactions. Importantly, experimental increase of ER-mitochondria contacts in human myotubes prevents palmitate-induced alterations of insulin signaling and action, whereas disruption of MAM integrity alters the action of the hormone. Lastly, we found an association between altered insulin signaling and ER-mitochondria interactions in human myotubes from obese subjects with or without T2D compared with healthy lean subjects. Collectively, our data reveal a new role of MAM integrity in insulin action of skeletal muscle and highlight MAM disruption as an essential subcellular alteration associated with muscle insulin resistance in mice and humans. Therefore, reduced ER-mitochondria coupling could be a common alteration of several insulin-sensitive tissues playing a key role in altered glucose homeostasis in the context of obesity and T2D. © 2018 by the American Diabetes Association.

  17. The Mitochondria-Targeted Antioxidant SkQ1 Downregulates Aryl Hydrocarbon Receptor-Dependent Genes in the Retina of OXYS Rats with AMD-Like Retinopathy

    Directory of Open Access Journals (Sweden)

    M. L. Perepechaeva

    2014-01-01

    Full Text Available The mitochondria-targeted antioxidant SkQ1 is a novel drug thought to retard development of age-related diseases. It has been shown that SkQ1 reduces clinical signs of retinopathy in senescence-accelerated OXYS rats, which are a known animal model of human age-related macular degeneration (AMD. The aim of this work was to test whether SkQ1 affects transcriptional activity of AhR (aryl hydrocarbon receptor and Nrf2 (nuclear factor erythroid 2-related factor 2, which are considered as AMD-associated genes in the retina of OXYS and Wistar rats. Our results showed that only AhR and AhR-dependent genes were sensitive to SkQ1. Dietary supplementation with SkQ1 decreased the AhR mRNA level in both OXYS and Wistar rats. At baseline, the retinal Cyp1a1 mRNA level was lower in OXYS rats. SkQ1 supplementation decreased the Cyp1a1 mRNA level in Wistar rats, but this level remained unchanged in OXYS rats. Baseline Cyp1a2 and Cyp1b1 mRNA expression was stronger in OXYS than in Wistar rats. In the OXYS strain, Cyp1a2 and Cyp1b1 mRNA levels decreased as a result of SkQ1 supplementation. These data suggest that the Cyp1a2 and Cyp1b1 enzymes are involved in the pathogenesis of AMD-like retinopathy of OXYS rats and are possible therapeutic targets of SkQ1.

  18. Mitochondria and redox homoeostasis as chemotherapeutic targets of Araucaria angustifolia (Bert.) O. Kuntze in human larynx HEp-2 cancer cells.

    Science.gov (United States)

    Branco, Cátia dos Santos; de Lima, Émilin Dreher; Rodrigues, Tiago Selau; Scheffel, Thamiris Becker; Scola, Gustavo; Laurino, Claudia Cilene Fernandes Correia; Moura, Sidnei; Salvador, Mirian

    2015-04-25

    Natural products are among one of the most promising fields in finding new molecular targets in cancer therapy. Laryngeal carcinoma is one of the most common cancers affecting the head and neck regions, and is associated with high morbidity rate if left untreated. The aim of this study was to examine the antiproliferative effect of Araucaria angustifolia on laryngeal carcinoma HEp-2 cells. The results showed that A. angustifolia extract (AAE) induced a significant cytotoxicity in HEp-2 cells compared to the non-tumor human epithelial (HEK-293) cells, indicating a selective activity of AAE for the cancer cells. A. angustifolia extract was able to increase oxidative damage to lipids and proteins, and the production of nitric oxide, along with the depletion of enzymatic antioxidant defenses (superoxide dismutase and catalase) in the tumor cell line. Moreover, AAE was able to induce DNA damage, nuclear fragmentation and chromatin condensation. A significant increase in the Apoptosis Inducing Factor (AIF), Bax, poly-(ADP-ribose) polymerase (PARP) and caspase-3 cleavage expression were also found. These effects could be related to the ability of AAE to increase the production of reactive oxygen species through inhibition of the mitochondrial electron transport chain complex I activity and ATP production by the tumor cells. The phytochemical analysis of A. angustifolia, performed using High Resolution Mass Spectrometry (HRMS) in MS and MS/MS mode, showed the presence of dodecanoic and hexadecanoic acids, and phenolic compounds, which may be associated with the chemotherapeutic effect observed in this study. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  19. Aging and mitochondria.

    Science.gov (United States)

    Gadaleta, M N; Cormio, A; Pesce, V; Lezza, A M; Cantatore, P

    1998-10-01

    Aging is a complex physiological phenomenon and several different theories have been elaborated about its origin. Among such theories, the 'mitochondrial theory of aging', which has gained a large support, indicates the accumulation of somatic mutations of mitochondrial DNA leading to the decline of mitochondrial functionality as one of the driving forces for the process itself. In this review data on rat and man from our laboratory and from recent literature have been thoroughly examined and compared in order to provide the 'state-of-the-art' on the role of mitochondria in aging. Alterations of structure and expression of mitochondrial genome with aging, to find out the eventual relevant changes of mitochondrial biogenesis, have been studied in rat whereas the relationship between cytochrome c oxidase activity and 'common deletion' has been studied in man. Results on the effect of acetyl-L-carnitine on the mitochondrial functionality are also reported.

  20. Alteration zones: are they a good target for gold deposits in Egypt

    International Nuclear Information System (INIS)

    Botros, N.S.

    2002-01-01

    Extensive rock alterations are a clearly visible characteristic of most Egyptian gold deposits and occurrences. The alterations occur either surrounding the auriferous quartz veins and/or structurally controlled by specific structural features, such as fractures and shear surfaces. Some samples of these alteration zones have proved to be anomalously enriched in gold while others are completely barren. Accordingly there is a controversy on the merit of alteration zones as good lead to gold. Here, the various types of wall rocks wall-rock alteration are reviewed with a discussion on the possible reaction that could have generated them. It is concluded that two main styles of alterations could be recognized in the field. The first results during the liberation of gold from the source rocks, and is characterized by being widely distributed and spatial relation to major structures. The second style, however, is related to the deposition of gold and is recognizable only within a few meters of the auriferous quartz veins. The potentiality of each style is discussed and applications of concept are offered. In general, alterations accompanying the liberation of gold are not completely devoid of gold, but may still retain some gold depending on the mineralogical siting of gold in the source rocks. Moreover, this type of alteration is a good criterion for the presence of gold in the nearby sites. Alterations accompanying deposition of gold, on the other hand, constitute a good target for gold particularly the portions that are dissected by minor quartz veins, veinlets and stockworks (silicification) where gold is believed to migrate to such sites with silica liberated during the different types of alterations. The presence of some efficient precipitants, such as sulphides, carbonates, clay minerals, sericites, iron oxides, chlorite and graphite in the alteration zones is a good indicator of the alteration zone. (author)

  1. Targeted deficiency of the transcriptional activator Hnf1alpha alters subnuclear positioning of its genomic targets.

    Directory of Open Access Journals (Sweden)

    Reini F Luco

    2008-05-01

    Full Text Available DNA binding transcriptional activators play a central role in gene-selective regulation. In part, this is mediated by targeting local covalent modifications of histone tails. Transcriptional regulation has also been associated with the positioning of genes within the nucleus. We have now examined the role of a transcriptional activator in regulating the positioning of target genes. This was carried out with primary beta-cells and hepatocytes freshly isolated from mice lacking Hnf1alpha, an activator encoded by the most frequently mutated gene in human monogenic diabetes (MODY3. We show that in Hnf1a-/- cells inactive endogenous Hnf1alpha-target genes exhibit increased trimethylated histone H3-Lys27 and reduced methylated H3-Lys4. Inactive Hnf1alpha-targets in Hnf1a-/- cells are also preferentially located in peripheral subnuclear domains enriched in trimethylated H3-Lys27, whereas active targets in wild-type cells are positioned in more central domains enriched in methylated H3-Lys4 and RNA polymerase II. We demonstrate that this differential positioning involves the decondensation of target chromatin, and show that it is spatially restricted rather than a reflection of non-specific changes in the nuclear organization of Hnf1a-deficient cells. This study, therefore, provides genetic evidence that a single transcriptional activator can influence the subnuclear location of its endogenous genomic targets in primary cells, and links activator-dependent changes in local chromatin structure to the spatial organization of the genome. We have also revealed a defect in subnuclear gene positioning in a model of a human transcription factor disease.

  2. TARGETING HYDROTHERMAL ALTERATIONS UTILIZING LANDSAT-8 ANDASTER DATA IN SHAHR-E-BABAK, IRAN

    Directory of Open Access Journals (Sweden)

    M. Safari

    2017-10-01

    Full Text Available Shahr-e-Babak tract of the Kerman metalogenic belt is one of the most potential segments of Urumieh–Dokhtar (Sahand-Bazman magmatic arc. This area encompasses several porphyry copper deposits in exploration, development and exploitation hierarchy. The aim of this study is to map hydrothermal alterations caused by early Cenozoic magmatic intrusions in Shahr-e-Babak area. To this purpose, mineral mapping methods including band combinations, ratios and multiplications as well as PCA and MNF data space transforms in SWIR and VNIR for both ASTER and OLI sensors. Alteration zones according to spectral signatures of each type of alteration mineral assemblages such as argillic, phyllic and propylitic are successfully mapped. For enhancing the target areas false color composites and HSI-RGB color space transform are performed on developed band combinations. Previous studies have proven the robust application of ASTER in geology and mineral exploration; nonetheless, the results of this investigation prove applicability of OLI sensor from landsat-8 for alteration mapping. According to the results, evidently OLI sensor data can accurately map alteration zones. Additionally, the 12-bit quantization of OLI data is its privilege over 8-bit data of ASTER in VNIR and SWIR, thus OLI high quality results, which makes it easy to distinguish targets with enhanced color contrast between the altered and unaltered rocks.

  3. Targeting Hydrothermal Alterations Utilizing LANDSAT-8 Andaster Data in Shahr-E Iran

    Science.gov (United States)

    Safari, M.; Pour, A. B.; Maghsoudi, A.; Hashim, M.

    2017-10-01

    Shahr-e-Babak tract of the Kerman metalogenic belt is one of the most potential segments of Urumieh-Dokhtar (Sahand-Bazman) magmatic arc. This area encompasses several porphyry copper deposits in exploration, development and exploitation hierarchy. The aim of this study is to map hydrothermal alterations caused by early Cenozoic magmatic intrusions in Shahr-e-Babak area. To this purpose, mineral mapping methods including band combinations, ratios and multiplications as well as PCA and MNF data space transforms in SWIR and VNIR for both ASTER and OLI sensors. Alteration zones according to spectral signatures of each type of alteration mineral assemblages such as argillic, phyllic and propylitic are successfully mapped. For enhancing the target areas false color composites and HSI-RGB color space transform are performed on developed band combinations. Previous studies have proven the robust application of ASTER in geology and mineral exploration; nonetheless, the results of this investigation prove applicability of OLI sensor from landsat-8 for alteration mapping. According to the results, evidently OLI sensor data can accurately map alteration zones. Additionally, the 12-bit quantization of OLI data is its privilege over 8-bit data of ASTER in VNIR and SWIR, thus OLI high quality results, which makes it easy to distinguish targets with enhanced color contrast between the altered and unaltered rocks.

  4. Early transcriptional changes in cardiac mitochondria during chronic doxorubicin exposure and mitigation by dexrazoxane in mice

    Energy Technology Data Exchange (ETDEWEB)

    Vijay, Vikrant; Moland, Carrie L.; Han, Tao; Fuscoe, James C. [Personalized Medicine Branch, Division of Systems Biology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079 (United States); Lee, Taewon [Department of Mathematics, Korea University, Sejong (Korea, Republic of); Herman, Eugene H. [Toxicology and Pharmacology Branch, Developmental Therapeutics Program, Division of Cancer Treatment and Diagnosis, The National Cancer Institute, 9609 Medical Center Drive, Rockville, MD 20850-9734 (United States); Jenkins, G. Ronald [Personalized Medicine Branch, Division of Systems Biology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079 (United States); Lewis, Sherry M. [Office of Scientific Coordination, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079 (United States); Cummings, Connie A. [UltraPath Imaging, 2228 Page Road, Durham, NC 27703 (United States); Gao, Yuan; Cao, Zhijun; Yu, Li-Rong [Biomarkers and Alternative Models Branch, Division of Systems Biology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079 (United States); Desai, Varsha G., E-mail: varsha.desai@fda.hhs.gov [Personalized Medicine Branch, Division of Systems Biology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079 (United States)

    2016-03-15

    Identification of early biomarkers of cardiotoxicity could help initiate means to ameliorate the cardiotoxic actions of clinically useful drugs such as doxorubicin (DOX). Since DOX has been shown to target mitochondria, transcriptional levels of mitochondria-related genes were evaluated to identify early candidate biomarkers in hearts of male B6C3F{sub 1} mice given a weekly intravenous dose of 3 mg/kg DOX or saline (SAL) for 2, 3, 4, 6, or 8 weeks (6, 9, 12, 18, or 24 mg/kg cumulative DOX doses, respectively). Also, a group of mice was pretreated (intraperitoneally) with the cardio-protectant, dexrazoxane (DXZ; 60 mg/kg) 30 min before each weekly dose of DOX or SAL. At necropsy a week after the last dose, increased plasma concentrations of cardiac troponin T (cTnT) were detected at 18 and 24 mg/kg cumulative DOX doses, whereas myocardial alterations were observed only at the 24 mg/kg dose. Of 1019 genes interrogated, 185, 109, 140, 184, and 451 genes were differentially expressed at 6, 9, 12, 18, and 24 mg/kg cumulative DOX doses, respectively, compared to concurrent SAL-treated controls. Of these, expression of 61 genes associated with energy metabolism and apoptosis was significantly altered before and after occurrence of myocardial injury, suggesting these as early genomics markers of cardiotoxicity. Much of these DOX-induced transcriptional changes were attenuated by pretreatment of mice with DXZ. Also, DXZ treatment significantly reduced plasma cTnT concentration and completely ameliorated cardiac alterations induced by 24 mg/kg cumulative DOX. This information on early transcriptional changes during DOX treatment may be useful in designing cardioprotective strategies targeting mitochondria. - Highlights: • Altered mitochondria-related gene expression before heart injury by doxorubicin • Dexrazoxane mitigated doxorubicin-induced early expression changes in mitochondria. • Dexrazoxane completely ameliorated doxorubicin-induced pathology in mouse heart.

  5. Therapeutic action of the mitochondria-targeted antioxidant SkQ1 on retinopathy in OXYS rats linked with improvement of VEGF and PEDF gene expression.

    Directory of Open Access Journals (Sweden)

    Anton M Markovets

    Full Text Available UNLABELLED: The incidence of age-related macular degeneration (AMD, the main cause of blindness in older patients in the developed countries, is increasing with the ageing population. At present there is no effective treatment for the prevailing geographic atrophy, dry AMD, whereas antiangiogenic therapies successful used in managing the wet form of AMD. Recently we showed that mitochondria-targeted antioxidant plastoquinonyl-decyl-triphenylphosphonium (SkQ1 is able to prevent the development and moreover caused regression of pre-existing signs of the retinopathy in OXYS rats, an animal model of AMD. Here we examine the effects of SkQ1 on expression of key regulators of angiogenesis vascular endothelial growth factor A (VEGF and its antagonist pigment epithelium-derived factor (PEDF genes in the retina of OXYS rats as evidenced by real-time PCR and an ELISA test for VEGF using Wistar rats as control. Ophthalmoscopic examinations confirmed that SkQ1 supplementation (from 1.5 to 3 months of age, 250 nmol/kg prevented development while eye drops SkQ1 (250 nM, from 9 to 12 months caused some reduction of retinopathy signs in OXYS rats and did not reveal any negative effects on the control Wistar rat's retina. Prevention of premature retinopathy by SkQ1 was connected with an increase of VEGF mRNA and protein in OXYS rat's retina up to the levels corresponding to the Wistar rats, and did not involve changes in PEDF expression. In contrast the treatment with SkQ1 drops caused a decrease of VEGF mRNA and protein levels and an increase in the PEDF mRNA level in the middle-aged OXYS rats, but in Wistar rats the changes of gene expression were the opposite. CONCLUSIONS: The beneficial effects of SkQ1 on retinopathy connected with normalization of expression of VEGF and PEDF in the retina of OXYS rats and depended on age of the animals and the stage of retinopathy.

  6. The Parkinson disease-related protein DJ-1 counteracts mitochondrial impairment induced by the tumour suppressor protein p53 by enhancing endoplasmic reticulum-mitochondria tethering.

    Science.gov (United States)

    Ottolini, Denis; Calì, Tito; Negro, Alessandro; Brini, Marisa

    2013-06-01

    DJ-1 was first identified as an oncogene. More recently, mutations in its gene have been found causative for autosomal recessive familial Parkinson disease. Numerous studies support the DJ-1 role in the protection against oxidative stress and maintenance of mitochondria structure; however, the mechanism of its protective function remains largely unknown. We investigated whether mitochondrial Ca(2+) homeostasis, a key parameter in cell physiology, could be a target for DJ-1 action. Here, we show that DJ-1 modulates mitochondrial Ca(2+) transients induced upon cell stimulation with an 1,4,5-inositol-tris-phosphate agonist by favouring the endoplasmic reticulum (ER)-mitochondria tethering. A reduction of DJ-1 levels results in mitochondria fragmentation and decreased mitochondrial Ca(2+) uptake in stimulated cells. To functionally couple these effects with the well-recognized cytoprotective role of DJ-1, we investigated its action in respect to the tumour suppressor p53. p53 overexpression in HeLa cells impairs their ability to accumulate Ca(2+) in the mitochondrial matrix, causes alteration of the mitochondrial morphology and reduces ER-mitochondria contact sites. Mitochondrial impairments are independent from Drp1 activation, since the co-expression of the dominant negative mutant of Drp1 failed to abolish them. DJ-1 overexpression prevents these alterations by re-establishing the ER-mitochondria tethering. Similarly, the co-expression of the pro-fusion protein Mitofusin 2 blocks the effects induced by p53 on mitochondria, confirming that the modulation of the ER-mitochondria contact sites is critical to mitochondria integrity. Thus, the impairment of ER-mitochondria communication, as a consequence of DJ-1 loss-of-function, may be detrimental for mitochondria-related processes and be at the basis of mitochondrial dysfunction observed in Parkinson disease.

  7. Ovarian ageing: the role of mitochondria in oocytes and follicles.

    Science.gov (United States)

    May-Panloup, Pascale; Boucret, Lisa; Chao de la Barca, Juan-Manuel; Desquiret-Dumas, Valérie; Ferré-L'Hotellier, Véronique; Morinière, Catherine; Descamps, Philippe; Procaccio, Vincent; Reynier, Pascal

    2016-11-01

    There is a great inter-individual variability of ovarian ageing, and almost 20% of patients consulting for infertility show signs of premature ovarian ageing. This feature, taken together with delayed childbearing in modern society, leads to the emergence of age-related ovarian dysfunction concomitantly with the desire for pregnancy. Assisted reproductive technology is frequently inefficacious in cases of ovarian ageing, thus raising the economic, medical and societal costs of the procedures. Ovarian ageing is characterized by quantitative and qualitative alteration of the ovarian oocyte reserve. Mitochondria play a central role in follicular atresia and could be the main target of the ooplasmic factors determining oocyte quality adversely affected by ageing. Indeed, the oocyte is the richest cell of the body in mitochondria and depends largely on these organelles to acquire competence for fertilization and early embryonic development. Moreover, the oocyte ensures the uniparental transmission and stability of the mitochondrial genome across the generations. This review focuses on the role played by mitochondria in ovarian ageing and on the possible consequences over the generations. PubMed was used to search the MEDLINE database for peer-reviewed original articles and reviews concerning mitochondria and ovarian ageing, in animal and human species. Searches were performed using keywords belonging to three groups: 'mitochondria' or 'mitochondrial DNA'; 'ovarian reserve', 'oocyte', 'ovary' or 'cumulus cells'; and 'ageing' or 'ovarian ageing'. These keywords were combined with other search phrases relevant to the topic. References from these articles were used to obtain additional articles. There is a close relationship, in mammalian models and humans, between mitochondria and the decline of oocyte quality with ageing. Qualitatively, ageing-related mitochondrial (mt) DNA instability, which leads to the accumulation of mtDNA mutations in the oocyte, plays a key role in

  8. Bovine lactoferricin causes apoptosis in Jurkat T-leukemia cells by sequential permeabilization of the cell membrane and targeting of mitochondria

    International Nuclear Information System (INIS)

    Mader, Jamie S.; Richardson, Angela; Salsman, Jayme; Top, Deniz; Antueno, Roberto de; Duncan, Roy; Hoskin, David W.

    2007-01-01

    Bovine lactoferricin (LfcinB) is a cationic antimicrobial peptide that kills Jurkat T-leukemia cells by the mitochondrial pathway of apoptosis. However, the process by which LfcinB triggers mitochondria-dependent apoptosis is not well understood. Here, we show that LfcinB-induced apoptosis in Jurkat T-leukemia cells was preceded by LfcinB binding to, and progressive permeabilization of the cell membrane. Colloidal gold electron microscopy revealed that LfcinB entered the cytoplasm of Jurkat T-leukemia cells prior to the onset of mitochondrial depolarization. LfcinB was not internalized by endocytosis because endocytosis inhibitors did not prevent LfcinB-induced cytotoxicity. Furthermore, intracellular delivery of LfcinB via fusogenic liposomes caused the death of Jurkat T-leukemia cells, as well as normal human fibroblasts. Collectively, these findings suggest that LfcinB caused damage to the cell membrane that allowed LfcinB to enter the cytoplasm of Jurkat T-leukemia cells and mediate cytotoxicity. In addition, confocal microscopy showed that intracellular LfcinB co-localized with mitochondria in Jurkat T-leukemia cells, while flow cytometry and colloidal gold electron microscopy showed that LfcinB rapidly associated with purified mitochondria. Furthermore, purified mitochondria treated with LfcinB rapidly lost transmembrane potential and released cytochrome c. We conclude that LfcinB-induced apoptosis in Jurkat T-leukemia cells resulted from cell membrane damage and the subsequent disruption of mitochondrial membranes by internalized LfcinB

  9. Alteration mineral mapping in inaccessible regions using target detection algorithms to ASTER data

    International Nuclear Information System (INIS)

    Pour, A B; Hashim, M; Park, Y

    2017-01-01

    In this study, the applications of target detection algorithms such as Constrained Energy Minimization (CEM), Orthogonal Subspace Projection (OSP) and Adaptive Coherence Estimator (ACE) to shortwave infrared bands of the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) data was investigated to extract geological information for alteration mineral mapping in poorly exposed lithologies in inaccessible domains. The Oscar II coast area north-eastern Graham Land, Antarctic Peninsula (AP) was selected in this study to conduct a satellite-based remote sensing mapping technique. It is an inaccessible region due to the remoteness of many rock exposures and the necessity to travel over sever mountainous and glacier-cover terrains for geological field mapping and sample collection. Fractional abundance of alteration minerals such as muscovite, kaolinite, illite, montmorillonite, epidote, chlorite and biotite were identified in alteration zones using CEM, OSP and ACE algorithms in poorly mapped and unmapped zones at district scale for the Oscar II coast area. The results of this investigation demonstrated the applicability of ASTER shortwave infrared spectral data for lithological and alteration mineral mapping in poorly exposed lithologies and inaccessible regions, particularly using the image processing algorithms that are capable to detect sub-pixel targets in the remotely sensed images, where no prior information is available. (paper)

  10. Mechanisms of resistance to quinolones: target alterations, decreased accumulation and DNA gyrase protection.

    Science.gov (United States)

    Ruiz, Joaquim

    2003-05-01

    Quinolones are broad-spectrum antibacterial agents, commonly used in both clinical and veterinary medicine. Their extensive use has resulted in bacteria rapidly developing resistance to these agents. Two mechanisms of quinolone resistance have been established to date: alterations in the targets of quinolones, and decreased accumulation due to impermeability of the membrane and/or an overexpression of efflux pump systems. Recently, mobile elements have also been described, carrying the qnr gene, which confers resistance to quinolones.

  11. Mitochondria in neutrophil apoptosis

    NARCIS (Netherlands)

    van Raam, B. J.; Verhoeven, A. J.; Kuijpers, T. W.

    2006-01-01

    Central in the regulation of the short life span of neutrophils are their mitochondria. These organelles hardly contribute to the energy status of neutrophils but play a vital role in the apoptotic process. Not only do the mitochondria contain cytotoxic proteins that are released during apoptosis

  12. Localization of mitochondria in living cells with rhodamine 123.

    Science.gov (United States)

    Johnson, L V; Walsh, M L; Chen, L B

    1980-01-01

    The laser dye rhodamine 123 is shown to be a specific probe for the localization of mitochondria in living cells. By virtue of its selectivity for mitochondria and its fluorescent properties, the detectability of mitochondria stained with rhodamine 123 is significantly improved over that provided by conventional light microscopic techniques. With the use of rhodamine 123, it is possible to detect alterations in mitochondrial distribution following transformation by Rous sarcoma virus and changes in the shape and organization of mitochondria induced by colchicine treatment. Images PMID:6965798

  13. Mitochondria: more than just a powerhouse.

    Science.gov (United States)

    McBride, Heidi M; Neuspiel, Margaret; Wasiak, Sylwia

    2006-07-25

    Pioneering biochemical studies have long forged the concept that the mitochondria are the 'energy powerhouse of the cell'. These studies, combined with the unique evolutionary origin of the mitochondria, led the way to decades of research focusing on the organelle as an essential, yet independent, functional component of the cell. Recently, however, our conceptual view of this isolated organelle has been profoundly altered with the discovery that mitochondria function within an integrated reticulum that is continually remodeled by both fusion and fission events. The identification of a number of proteins that regulate these activities is beginning to provide mechanistic details of mitochondrial membrane remodeling. However, the broader question remains regarding the underlying purpose of mitochondrial dynamics and the translation of these morphological transitions into altered functional output. One hypothesis has been that mitochondrial respiration and metabolism may be spatially and temporally regulated by the architecture and positioning of the organelle. Recent evidence supports and expands this idea by demonstrating that mitochondria are an integral part of multiple cell signaling cascades. Interestingly, proteins such as GTPases, kinases and phosphatases are involved in bi-directional communication between the mitochondrial reticulum and the rest of the cell. These proteins link mitochondrial function and dynamics to the regulation of metabolism, cell-cycle control, development, antiviral responses and cell death. In this review we will highlight the emerging evidence that provides molecular definition to mitochondria as a central platform in the execution of diverse cellular events.

  14. Functional alterations of astrocytes in mental disorders: pharmacological significance as a drug target

    Directory of Open Access Journals (Sweden)

    Yutaka eKoyama

    2015-07-01

    Full Text Available Astrocytes play an essential role in supporting brain functions in physiological and pathological states. Modulation of their pathophysiological responses have beneficial actions on nerve tissue injured by brain insults and neurodegenerative diseases, therefore astrocytes are recognized as promising targets for neuroprotective drugs. Recent investigations have identified several astrocytic mechanisms for modulating synaptic transmission and neural plasticity. These include altered expression of transporters for neurotransmitters, release of gliotransmitters and neurotrophic factors, and intercellular communication through gap junctions. Investigation of patients with mental disorders shows morphological and functional alterations in astrocytes. According to these observations, manipulation of astrocytic function by gene mutation and pharmacological tools reproduce mental disorder-like behavior in experimental animals. Some drugs clinically used for mental disorders affect astrocyte function. As experimental evidence shows their role in the pathogenesis of mental disorders, astrocytes have gained much attention as drug targets for mental disorders. In this article, I review functional alterations of astrocytes in several mental disorders including schizophrenia, mood disorder, drug dependence, and neurodevelopmental disorders. The pharmacological significance of astrocytes in mental disorders is also discussed.

  15. Identification of the Consistently Altered Metabolic Targets in Human Hepatocellular Carcinoma.

    Science.gov (United States)

    Nwosu, Zeribe Chike; Megger, Dominik Andre; Hammad, Seddik; Sitek, Barbara; Roessler, Stephanie; Ebert, Matthias Philip; Meyer, Christoph; Dooley, Steven

    2017-09-01

    Cancer cells rely on metabolic alterations to enhance proliferation and survival. Metabolic gene alterations that repeatedly occur in liver cancer are largely unknown. We aimed to identify metabolic genes that are consistently deregulated, and are of potential clinical significance in human hepatocellular carcinoma (HCC). We studied the expression of 2,761 metabolic genes in 8 microarray datasets comprising 521 human HCC tissues. Genes exclusively up-regulated or down-regulated in 6 or more datasets were defined as consistently deregulated. The consistent genes that correlated with tumor progression markers ( ECM2 and MMP9) (Pearson correlation P < .05) were used for Kaplan-Meier overall survival analysis in a patient cohort. We further compared proteomic expression of metabolic genes in 19 tumors vs adjacent normal liver tissues. We identified 634 consistent metabolic genes, ∼60% of which are not yet described in HCC. The down-regulated genes (n = 350) are mostly involved in physiologic hepatocyte metabolic functions (eg, xenobiotic, fatty acid, and amino acid metabolism). In contrast, among consistently up-regulated metabolic genes (n = 284) are those involved in glycolysis, pentose phosphate pathway, nucleotide biosynthesis, tricarboxylic acid cycle, oxidative phosphorylation, proton transport, membrane lipid, and glycan metabolism. Several metabolic genes (n = 434) correlated with progression markers, and of these, 201 predicted overall survival outcome in the patient cohort analyzed. Over 90% of the metabolic targets significantly altered at the protein level were similarly up- or down-regulated as in genomic profile. We provide the first exposition of the consistently altered metabolic genes in HCC and show that these genes are potentially relevant targets for onward studies in preclinical and clinical contexts.

  16. Identification of the Consistently Altered Metabolic Targets in Human Hepatocellular CarcinomaSummary

    Directory of Open Access Journals (Sweden)

    Zeribe Chike Nwosu

    2017-09-01

    Full Text Available Background & Aims: Cancer cells rely on metabolic alterations to enhance proliferation and survival. Metabolic gene alterations that repeatedly occur in liver cancer are largely unknown. We aimed to identify metabolic genes that are consistently deregulated, and are of potential clinical significance in human hepatocellular carcinoma (HCC. Methods: We studied the expression of 2,761 metabolic genes in 8 microarray datasets comprising 521 human HCC tissues. Genes exclusively up-regulated or down-regulated in 6 or more datasets were defined as consistently deregulated. The consistent genes that correlated with tumor progression markers (ECM2 and MMP9 (Pearson correlation P < .05 were used for Kaplan-Meier overall survival analysis in a patient cohort. We further compared proteomic expression of metabolic genes in 19 tumors vs adjacent normal liver tissues. Results: We identified 634 consistent metabolic genes, ∼60% of which are not yet described in HCC. The down-regulated genes (n = 350 are mostly involved in physiologic hepatocyte metabolic functions (eg, xenobiotic, fatty acid, and amino acid metabolism. In contrast, among consistently up-regulated metabolic genes (n = 284 are those involved in glycolysis, pentose phosphate pathway, nucleotide biosynthesis, tricarboxylic acid cycle, oxidative phosphorylation, proton transport, membrane lipid, and glycan metabolism. Several metabolic genes (n = 434 correlated with progression markers, and of these, 201 predicted overall survival outcome in the patient cohort analyzed. Over 90% of the metabolic targets significantly altered at the protein level were similarly up- or down-regulated as in genomic profile. Conclusions: We provide the first exposition of the consistently altered metabolic genes in HCC and show that these genes are potentially relevant targets for onward studies in preclinical and clinical contexts. Keywords: Liver Cancer, HCC, Tumor Metabolism

  17. RNA Editing in Plant Mitochondria

    Science.gov (United States)

    Hiesel, Rudolf; Wissinger, Bernd; Schuster, Wolfgang; Brennicke, Axel

    1989-12-01

    Comparative sequence analysis of genomic and complementary DNA clones from several mitochondrial genes in the higher plant Oenothera revealed nucleotide sequence divergences between the genomic and the messenger RNA-derived sequences. These sequence alterations could be most easily explained by specific post-transcriptional nucleotide modifications. Most of the nucleotide exchanges in coding regions lead to altered codons in the mRNA that specify amino acids better conserved in evolution than those encoded by the genomic DNA. Several instances show that the genomic arginine codon CGG is edited in the mRNA to the tryptophan codon TGG in amino acid positions that are highly conserved as tryptophan in the homologous proteins of other species. This editing suggests that the standard genetic code is used in plant mitochondria and resolves the frequent coincidence of CGG codons and tryptophan in different plant species. The apparently frequent and non-species-specific equivalency of CGG and TGG codons in particular suggests that RNA editing is a common feature of all higher plant mitochondria.

  18. Mitochondria are the target organelle of differentiation-inducing factor-3, an anti-tumor agent isolated from Dictyostelium discoideum [corrected].

    Directory of Open Access Journals (Sweden)

    Yuzuru Kubohara

    Full Text Available Differentiation-inducing factor-3 (DIF-3, found in the cellular slime mold Dictyostelium discoideum, and its derivatives such as butoxy-DIF-3 (Bu-DIF-3 are potent anti-tumor agents. However, the precise mechanisms underlying the actions of DIF-3 remain to be elucidated. In this study, we synthesized a green fluorescent derivative of DIF-3, BODIPY-DIF-3, and a control fluorescent compound, Bu-BODIPY (butyl-BODIPY, and investigated how DIF-like molecules behave in human cervical cancer HeLa cells by using both fluorescence and electron microscopy. BODIPY-DIF-3 at 5-20 µ M suppressed cell growth in a dose-dependent manner, whereas Bu-BODIPY had minimal effect on cell growth. When cells were incubated with BODIPY-DIF-3 at 20 µM, it penetrated cell membranes within 0.5 h and localized mainly in mitochondria, while Bu-BODIPY did not stain the cells. Exposure of cells for 1-3 days to DIF-3, Bu-DIF-3, BODIPY-DIF-3, or CCCP (a mitochondrial uncoupler induced substantial mitochondrial swelling, suppressing cell growth. When added to isolated mitochondria, DIF-3, Bu-DIF-3, and BOIDPY-DIF-3, like CCCP, dose-dependently promoted the rate of oxygen consumption, but Bu-BODIPY did not. Our results suggest that these bioactive DIF-like molecules suppress cell growth, at least in part, by disturbing mitochondrial activity. This is the first report showing the cellular localization and behavior of DIF-like molecules in mammalian tumor cells.

  19. Engineered Cpf1 variants with altered PAM specificities increase genome targeting range

    Science.gov (United States)

    Gao, Linyi; Cox, David B.T.; Yan, Winston X.; Manteiga, John C.; Schneider, Martin W.; Yamano, Takashi; Nishimasu, Hiroshi; Nureki, Osamu; Crosetto, Nicola; Zhang, Feng

    2017-01-01

    The RNA-guided endonuclease Cpf1 is a promising tool for genome editing in eukaryotic cells1–7. However, the utility of the commonly used Acidaminococcus sp. BV3L6 Cpf1 (AsCpf1) and Lachnospiraceae bacterium ND2006 Cpf1 (LbCpf1) is limited by their requirement of a TTTV protospacer adjacent motif (PAM) in the DNA substrate. To address this limitation, we performed a structure-guided mutagenesis screen to increase the targeting range of Cpf1. We engineered two AsCpf1 variants carrying the mutations S542R/K607R and S542R/K548V/N552R, which recognize TYCV and TATV PAMs, respectively, with enhanced activities in vitro and in human cells. Genome-wide assessment of off-target activity using BLISS7 assay indicated that these variants retain high DNA targeting specificity, which we further improved by introducing an additional non-PAM-interacting mutation. Introducing the identified mutations at their corresponding positions in LbCpf1 similarly altered its PAM specificity. Together, these variants increase the targeting range of Cpf1 by approximately three-fold in human coding sequences to one cleavage site per ~11 bp. PMID:28581492

  20. Using Copy Number Alterations to Identify New Therapeutic Targets for Bladder Carcinoma

    Directory of Open Access Journals (Sweden)

    Donatella Conconi

    2016-02-01

    Full Text Available Bladder cancer represents the ninth most widespread malignancy throughout the world. It is characterized by the presence of two different clinical and prognostic subtypes: non-muscle-invasive bladder cancers (NMIBCs and muscle-invasive bladder cancers (MIBCs. MIBCs have a poor outcome with a common progression to metastasis. Despite improvements in knowledge, treatment has not advanced significantly in recent years, with the absence of new therapeutic targets. Because of the limitations of current therapeutic options, the greater challenge will be to identify biomarkers for clinical application. For this reason, we compared our array comparative genomic hybridization (array-CGH results with those reported in literature for invasive bladder tumors and, in particular, we focused on the evaluation of copy number alterations (CNAs present in biopsies and retained in the corresponding cancer stem cell (CSC subpopulations that should be the main target of therapy. According to our data, CCNE1, MYC, MDM2 and PPARG genes could be interesting therapeutic targets for bladder CSC subpopulations. Surprisingly, HER2 copy number gains are not retained in bladder CSCs, making the gene-targeted therapy less interesting than the others. These results provide precious advice for further study on bladder therapy; however, the clinical importance of these results should be explored.

  1. Cellular Signaling Pathway Alterations and Potential Targeted Therapies for Medullary Thyroid Carcinoma

    Directory of Open Access Journals (Sweden)

    Serena Giunti

    2013-01-01

    Full Text Available Parafollicular C-cell-derived medullary thyroid cancer (MTC comprises 3% to 4% of all thyroid cancers. While cytotoxic treatments have been shown to have limited efficacy, targeted molecular therapies that inhibit rearranged during transfection (RET and other tyrosine kinase receptors that are mainly involved in angiogenesis have shown great promise in the treatment of metastatic or locally advanced MTC. Multi-tyrosine kinase inhibitors such as vandetanib, which is already approved for the treatment of progressive MTC, and cabozantinib have shown distinct advantages with regard to rates of disease response and control. However, these types of tyrosine kinase inhibitor compounds are able to concurrently block several types of targets, which limits the understanding of RET as a specific target. Moreover, important resistances to tyrosine kinase inhibitors can occur, which limit the long-term efficacy of these treatments. Deregulated cellular signaling pathways and genetic alterations in MTC, particularly the activation of the RAS/mammalian target of rapamycin (mTOR cascades and RET crosstalk signaling, are now emerging as novel and potentially promising therapeutic treatments for aggressive MTC.

  2. Target genes discovery through copy number alteration analysis in human hepatocellular carcinoma.

    Science.gov (United States)

    Gu, De-Leung; Chen, Yen-Hsieh; Shih, Jou-Ho; Lin, Chi-Hung; Jou, Yuh-Shan; Chen, Chian-Feng

    2013-12-21

    High-throughput short-read sequencing of exomes and whole cancer genomes in multiple human hepatocellular carcinoma (HCC) cohorts confirmed previously identified frequently mutated somatic genes, such as TP53, CTNNB1 and AXIN1, and identified several novel genes with moderate mutation frequencies, including ARID1A, ARID2, MLL, MLL2, MLL3, MLL4, IRF2, ATM, CDKN2A, FGF19, PIK3CA, RPS6KA3, JAK1, KEAP1, NFE2L2, C16orf62, LEPR, RAC2, and IL6ST. Functional classification of these mutated genes suggested that alterations in pathways participating in chromatin remodeling, Wnt/β-catenin signaling, JAK/STAT signaling, and oxidative stress play critical roles in HCC tumorigenesis. Nevertheless, because there are few druggable genes used in HCC therapy, the identification of new therapeutic targets through integrated genomic approaches remains an important task. Because a large amount of HCC genomic data genotyped by high density single nucleotide polymorphism arrays is deposited in the public domain, copy number alteration (CNA) analyses of these arrays is a cost-effective way to reveal target genes through profiling of recurrent and overlapping amplicons, homozygous deletions and potentially unbalanced chromosomal translocations accumulated during HCC progression. Moreover, integration of CNAs with other high-throughput genomic data, such as aberrantly coding transcriptomes and non-coding gene expression in human HCC tissues and rodent HCC models, provides lines of evidence that can be used to facilitate the identification of novel HCC target genes with the potential of improving the survival of HCC patients.

  3. Apoptosis of murine melanoma B16-BL6 cells induced by quercetin targeting mitochondria, inhibiting expression of PKC-alpha and translocating PKC-delta.

    Science.gov (United States)

    Zhang, Xian-Ming; Chen, Jia; Xia, Yu-Gui; Xu, Qiang

    2005-03-01

    In our previous study, quercetin was found to induce apoptosis of murine melanoma B16-BL6 cells. The cellular and molecular mechanism of quercetin-induced apoptosis was investigated in the present study. Nuclear morphology was determined by fluorescence microscopy. DNA fragmentation was analyzed by electrophoresis and quantified by the diphenylamine method. The transmembrane potential of mitochondria was measured by flow cytometry. Bcl-2, Bcl-X(L), PKC-alpha, PKC-beta, and PKC-delta were detected by Western blotting. Caspase activity was determined spectrophotometrically. Quercetin induced the condensation of nuclei of B16-BL6 cells in a dose-dependent pattern as visualized by Hoechst 33258 and propidium iodide dying. Phorbol 12-myristate 13-acetate (PMA), a PKC activator, significantly enhanced apoptosis induced by quercetin, while doxorubicin, a PKC inhibitor, markedly decreased it. Both PMA and doxorubicin showed a consistent effect on the fragmentation of nuclear DNA caused by various dosages of quercetin. Quercetin dose-dependently led to loss of the mitochondrial membrane potential, which was also significantly reinforced or antagonized by PMA and doxorubicin, respectively. Moreover, PMA showed reinforcement, while doxorubicin showed significant antagonization, of the quercetin-mediated decrease in the expression of Bcl-2. Quercetin promoted caspase-3 activity in a dose-dependent manner, which was also regulated by PMA and doxorubicin with a pattern similar to that seen in their effect on apoptosis, mitochondrial membrane potential and Bcl-2 expression, but none of these were directly affected by PMA and doxorubicin. Free fatty acid and chlorpromazine, a PKC activator and inhibitor, respectively, did not interfere with these effects of quercetin. B16-BL6 cells expressed PKC-alpha, PKC-beta, and PKC-delta. Quercetin dose-dependently inhibited the expression of PKC-alpha but not that of PKC-beta and PKC-delta. Doxorubicin almost completely blocked the effect of

  4. On Cellular Darwinism: Mitochondria.

    Science.gov (United States)

    Bull, Larry

    2016-01-01

    The significant role of mitochondria within cells is becoming increasingly clear. This letter uses the NKCS model of coupled fitness landscapes to explore aspects of organelle-nucleus coevolution. The phenomenon of mitochondrial diversity is allowed to emerge under a simple intracellular evolutionary process, including varying the relative rate of evolution by the organelle. It is shown how the conditions for the maintenance of more than one genetic variant of mitochondria are similar to those previously suggested as needed for the original symbiotic origins of the relationship using the NKCS model.

  5. Oxaliplatin-induced Oxidative Stress Provokes Toxicity in Isolated Rat Liver Mitochondria.

    Science.gov (United States)

    Tabassum, Heena; Waseem, Mohammad; Parvez, Suhel; Qureshi, M Irfan

    2015-11-01

    Oxaliplatin is a widely employed platinum-derived chemotherapeutic agent commonly used for the treatment of colorectal cancer. Unfortunately, the benefit of this important drug is compromised by severe side effects such as neuropathy, ototoxicity, gastrointestinal toxicity, and hematological toxicity. Recently, few studies have also suggested the occurrence of hepatotoxicity in oxaliplatin-treated patients. Mitochondria have emerged as targets for anticancer drugs in various kinds of toxicity including hepatotoxicity that can lead to neoplastic disease. Oxidative stress is a well-established biomarker of mitochondrial toxicity. The purpose of this study was to investigate the dose-dependent damage caused by oxaliplatin on isolated liver mitochondria under in vitro conditions. The study was conducted in mitochondria isolated from liver of Wistar rats. Oxaliplatin was incubated with mitochondria in a dose-dependent manner under in vitro conditions. Oxidative stress indexes, non-enzymatic and enzymatic antioxidants were evaluated, looking at the overall armamentarium against the toxicity induced by oxaliplatin. Oxaliplatin caused a significant rise in the mitochondrial oxidative stress indexes lipid peroxidation and protein carbonyl. Alterations in the levels of non-enzymatic antioxidants and activities of enzymatic antioxidants were also observed. Oxidative stress plays an important role in the mitochondrial toxicity of oxaliplatin. The integrity of the hepatic tissue is compromised by the reactive oxygen species-mediated lipid peroxidation and protein carbonyl formation. Copyright © 2015 IMSS. Published by Elsevier Inc. All rights reserved.

  6. Protein S-glutathionylation lowers superoxide/hydrogen peroxide release from skeletal muscle mitochondria through modification of complex I and inhibition of pyruvate uptake.

    Directory of Open Access Journals (Sweden)

    Robert M Gill

    Full Text Available Protein S-glutathionylation is a reversible redox modification that regulates mitochondrial metabolism and reactive oxygen species (ROS production in liver and cardiac tissue. However, whether or not it controls ROS release from skeletal muscle mitochondria has not been explored. In the present study, we examined if chemically-induced protein S-glutathionylation could alter superoxide (O2●-/hydrogen peroxide (H2O2 release from isolated muscle mitochondria. Disulfiram, a powerful chemical S-glutathionylation catalyst, was used to S-glutathionylate mitochondrial proteins and ascertain if it can alter ROS production. It was found that O2●-/H2O2 release rates from permeabilized muscle mitochondria decreased with increasing doses of disulfiram (100-500 μM. This effect was highest in mitochondria oxidizing succinate or palmitoyl-carnitine, where a ~80-90% decrease in the rate of ROS release was observed. Similar effects were detected in intact mitochondria respiring under state 4 conditions. Incubation of disulfiram-treated mitochondria with DTT (2 mM restored ROS release confirming that these effects were associated with protein S-glutathionylation. Disulfiram treatment also inhibited phosphorylating and proton leak-dependent respiration. Radiolabelled substrate uptake experiments demonstrated that disulfiram inhibited pyruvate import but had no effect on carnitine uptake. Immunoblot analysis of complex I revealed that it contained several protein S-glutathionylation targets including NDUSF1, a subunit required for NADH oxidation. Taken together, these results demonstrate that O2●-/H2O2 release from muscle mitochondria can be altered by protein S-glutathionylation. We attribute these changes to the protein S-glutathionylation complex I and inhibition of mitochondrial pyruvate carrier.

  7. Vorinostat in combination with bortezomib in patients with advanced malignancies directly alters transcription of target genes.

    Science.gov (United States)

    Kolesar, Jill M; Traynor, Anne M; Holen, Kyle D; Hoang, Tien; Seo, Songwon; Kim, Kyungmann; Alberti, Dona; Espinoza-Delgado, Igor; Wright, John J; Wilding, George; Bailey, Howard H; Schelman, William R

    2013-09-01

    Vorinostat is a small molecule inhibitor of class I and II histone deacetylase enzymes which alters the expression of target genes including the cell cycle gene p21, leading to cell cycle arrest and apoptosis. Patients enrolled in a phase I trial were treated with vorinostat alone on day 1 and vorinostat and bortezomib in combination on day 9. Paired biopsies were obtained in eleven subjects. Blood samples were obtained on days 1 and 9 of cycle 1 prior to dosing and 2 and 6 h post-dosing in all 60 subjects. Gene expression of p21, HSP70, AKT, Nur77, ERB1, and ERB2 was evaluated in peripheral blood mononuclear cells and tissue samples. Chromatin immunoprecipitation of p21, HSP70, and Nur77 was also performed in biopsy samples. In peripheral blood mononuclear cells, Nur77 was significantly and consistently decreased 2 h after vorinostat administration on both days 1 and 9, median ratio of gene expression relative to baseline of 0.69 with interquartile range 0.49-1.04 (p vorinostat and bortezomib. p21, a downstream target of Nur77, was significantly decreased on day 9, 2 and 6 h after administration of vorinostat and bortezomib, 0.67 (0.41-1.03) (p vorinostat in tissue biopsies in most patients. Vorinostat inhibits Nur77 expression, which in turn may decrease p21 and AKT expression in PBMCs. The influence of vorinostat on target gene expression in tumor tissue was variable; however, most patients demonstrated interaction of acetylated H3 with Nur77, HSP70, and p21 which provides evidence of interaction with the transcriptionally active acetylated H3.

  8. Conserved genes encode guide RNAs in mitochondria of Crithidia fasciculata

    NARCIS (Netherlands)

    van der Spek, H.; Arts, G. J.; Zwaal, R. R.; van den Burg, J.; Sloof, P.; Benne, R.

    1991-01-01

    RNA editing is the post-transcriptional alteration of the nucleotide sequence of RNA, which in trypanosome mitochondria is characterized by the insertion and deletion of uridine residues. It has recently been proposed that the information for the sequence alteration in Leishmania tarentolae is

  9. Potassium channels in brain mitochondria.

    Science.gov (United States)

    Bednarczyk, Piotr

    2009-01-01

    Potassium channels are the most widely distributed class of ion channels. These channels are transmembrane proteins known to play important roles in both normal and pathophysiological functions in all cell types. Various potassium channels are recognised as potential therapeutic targets in the treatment of Parkinson's disease, Alzheimer's disease, brain/spinal cord ischaemia and sepsis. In addition to their importance as therapeutic targets, certain potassium channels are known for their beneficial roles in anaesthesia, cardioprotection and neuroprotection. Some types of potassium channels present in the plasma membrane of various cells have been found in the inner mitochondrial membrane as well. Potassium channels have been proposed to regulate mitochondrial membrane potential, respiration, matrix volume and Ca(+) ion homeostasis. It has been proposed that mitochondrial potassium channels mediate ischaemic preconditioning in various tissues. However, the specificity of a pharmacological agents and the mechanisms underlying their effects on ischaemic preconditioning remain controversial. The following potassium channels from various tissues have been identified in the inner mitochondrial membrane: ATP-regulated (mitoK(ATP)) channel, large conductance Ca(2+)-regulated (mitoBK(Ca)) channel, intermediate conductance Ca(2+)-regulated (mitoIK(Ca)) channel, voltage-gated (mitoKv1.3 type) channel, and twin-pore domain (mitoTASK-3) channel. It has been shown that increased potassium flux into brain mitochondria induced by either the mitoK(ATP) channel or mitoBK(Ca) channel affects the beneficial effects on neuronal cell survival under pathological conditions. Recently, differential distribution of mitoBK(Ca) channels has been observed in neuronal mitochondria. These findings may suggest a neuroprotective role for the mitoBK(Ca) channel in specific brain structures. This minireview summarises current data on brain mitochondrial potassium channels and the efforts to identify

  10. A potyvirus vector efficiently targets recombinant proteins to chloroplasts, mitochondria and nuclei in plant cells when expressed at the amino terminus of the polyprotein.

    Science.gov (United States)

    Majer, Eszter; Navarro, José-Antonio; Daròs, José-Antonio

    2015-09-01

    Plant virus-based expression systems allow quick and efficient production of recombinant proteins in plant biofactories. Among them, a system derived from tobacco etch virus (TEV; genus potyvirus) permits coexpression of equimolar amounts of several recombinant proteins. This work analyzed how to target recombinant proteins to different subcellular localizations in the plant cell using this system. We constructed TEV clones in which green fluorescent protein (GFP), with a chloroplast transit peptide (cTP), a nuclear localization signal (NLS) or a mitochondrial targeting peptide (mTP) was expressed either as the most amino-terminal product or embedded in the viral polyprotein. Results showed that cTP and mTP mediated efficient translocation of GFP to the corresponding organelle only when present at the amino terminus of the viral polyprotein. In contrast, the NLS worked efficiently at both positions. Viruses expressing GFP in the amino terminus of the viral polyprotein produced milder symptoms. Untagged GFPs and cTP and NLS tagged amino-terminal GFPs accumulated to higher amounts in infected tissues. Finally, viral progeny from clones with internal GFPs maintained the extra gene better. These observations will help in the design of potyvirus-based vectors able to coexpress several proteins while targeting different subcellular localizations, as required in plant metabolic engineering. Copyright © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Isolation of rat adrenocortical mitochondria

    Energy Technology Data Exchange (ETDEWEB)

    Solinas, Paola [Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, OH 44106 (United States); Department of Medicine, Center for Mitochondrial Disease, School of Medicine, Case Western Reserve University, Cleveland, OH 44106 (United States); Fujioka, Hisashi [Electron Microscopy Facility, Department of Pharmacology, Center for Mitochondrial Disease, School of Medicine, Case Western Reserve University, Cleveland, OH 44106 (United States); Tandler, Bernard [Department of Biological Sciences, School of Dental Medicine, Center for Mitochondrial Disease, School of Medicine, Case Western Reserve University, Cleveland, OH 44106 (United States); Hoppel, Charles L., E-mail: charles.hoppel@case.edu [Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, OH 44106 (United States); Department of Medicine, Center for Mitochondrial Disease, School of Medicine, Case Western Reserve University, Cleveland, OH 44106 (United States)

    2012-10-12

    Highlights: Black-Right-Pointing-Pointer A method for isolation of adrenocortical mitochondria from the adrenal gland of rats is described. Black-Right-Pointing-Pointer The purified isolated mitochondria show excellent morphological integrity. Black-Right-Pointing-Pointer The properties of oxidative phosphorylation are excellent. Black-Right-Pointing-Pointer The method increases the opportunity of direct analysis of adrenal mitochondria from small animals. -- Abstract: This report describes a relatively simple and reliable method for isolating adrenocortical mitochondria from rats in good, reasonably pure yield. These organelles, which heretofore have been unobtainable in isolated form from small laboratory animals, are now readily accessible. A high degree of mitochondrial purity is shown by the electron micrographs, as well as the structural integrity of each mitochondrion. That these organelles have retained their functional integrity is shown by their high respiratory control ratios. In general, the biochemical performance of these adrenal cortical mitochondria closely mirrors that of typical hepatic or cardiac mitochondria.

  12. Oxidative damage and aging: spotlight on mitochondria.

    Science.gov (United States)

    Linford, Nancy J; Schriner, Samuel E; Rabinovitch, Peter S

    2006-03-01

    Whereas free radical damage has been proposed as a key component in the tissue degeneration associated with aging, there has been little evidence that free radical damage limits life span in mammals. The current research shows that overexpression of the antioxidant enzyme catalase in mitochondria can extend mouse life span. These results highlight the importance of mitochondrial damage in aging and suggest that when targeted appropriately, boosting antioxidant defenses can increase mammalian life span.

  13. A novel mitochondria-targeted two-photon fluorescent probe for dynamic and reversible detection of the redox cycles between peroxynitrite and glutathione.

    Science.gov (United States)

    Sun, Chunlong; Du, Wen; Wang, Peng; Wu, Yang; Wang, Baoqin; Wang, Jun; Xie, Wenjun

    2017-12-16

    Redox homeostasis is important for maintenance of normal physiological functions within cells. Redox state of cells is primarily a consequence of precise balance between levels of reducing equivalents and reactive oxygen species. Redox homeostasis between peroxynitrite (ONOO - ) and glutathione (GSH) is closely associated with physiological and pathological processes, such as prolonged relaxation in vascular tissues and smooth muscle preparations, attenuation of hepatic necrosis, and activation of matrix metalloproteinase-2. We report a two-photon fluorescent probe (TP-Se) based on water-soluble carbazole-based compound, which integrates with organic selenium, to monitor changes in ONOO - /GSH levels in cells. This probe can reversibly respond to ONOO - and GSH and exhibits high selectivity, sensitivity, and mitochondrial targeting. The probe was successfully applied to visualize changes in redox cycles during ONOO - outbreak and antioxidant GSH repair in cells. The probe will lead to significant development on redox events involved in cellular redox regulation. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Natural selection of mitochondria during somatic lifetime promotes healthy aging

    DEFF Research Database (Denmark)

    Rodell, Anders; Rasmussen, Lene J; Bergersen, Linda H

    2013-01-01

    Stimulation of mitochondrial biogenesis during life-time challenges both eliminates disadvantageous properties and drives adaptive selection of advantageous phenotypic variations. Intermittent fission and fusion of mitochondria provide specific targets for health promotion by brief temporal...... stressors, interspersed with periods of recovery and biogenesis. For mitochondria, the mechanisms of selection, variability, and heritability, are complicated by interaction of two independent genomes, including the multiple copies of DNA in each mitochondrion, as well as the shared nuclear genome of each...

  15. Hexokinase-2 bound to mitochondria: Cancer's stygian link to the “Warburg effect” and a pivotal target for effective therapy☆

    Science.gov (United States)

    Mathupala, Saroj P.; Ko, Young H.; Pedersen, Peter L.

    2009-01-01

    deplete ATP. Biochem Biophys Res Commun 2004;324(1):269−75] is the use of the small molecule 3-bromopyruvate (3-BP) that selectively enters and destroys the cells of large tumors in animals by targeting both HK-2 and the mitochondrial ATP synthasome. This leads to very rapid ATP depletion and tumor destruction without harm to the animals. This review focuses on the multiple roles played by HK-2 in cancer and its potential as a metabolic target for complete cancer destruction. PMID:19101634

  16. Glutathione and Mitochondria

    Directory of Open Access Journals (Sweden)

    Vicent eRibas

    2014-07-01

    Full Text Available Glutathione (GSH is the main nonprotein thiol in cells whose functions are dependent on the redox-active thiol of its cysteine moiety that serves as a cofactor for a number of antioxidant and detoxifying enzymes. While synthesized exclusively in the cytosol from its constituent amino acids, GSH is distributed in different compartments, including mitochondria where its concentration in the matrix equals that of the cytosol. This feature and its negative charge at physiological pH imply the existence of specific carriers to import GSH from the cytosol to the mitochondrial matrix, where it plays a key role in defense against respiration-induced reactive oxygen species and in the detoxification of lipid hydroperoxides and electrophiles. Moreover, as mitochondria play a central strategic role in the activation and mode of cell death, mitochondrial GSH has been shown to critically regulate the level of sensitization to secondary hits that induce mitochondrial membrane permeabilization and release of proteins confined in the intermembrane space that once in the cytosol engage the molecular machinery of cell death. In this review, we summarize recent data on the regulation of mitochondrial GSH and its role in cell death and prevalent human diseases, such as cancer, fatty liver disease and Alzheimer’s disease.

  17. Dysplasia and overgrowth. Magnetic resonance imaging of pediatric brain abnormalities secondary to alterations in the mechanistic target of rapamycin pathway

    Energy Technology Data Exchange (ETDEWEB)

    Shrot, Shai [Johns Hopkins University School of Medicine, Division of Pediatric Radiology and Pediatric Neuroradiology, Russell H. Morgan Department of Radiology and Radiological Science, Baltimore, MD (United States); Sheba Medical Center, Department of Diagnostic Imaging, Ramat-Gan (Israel); Hwang, Misun; Huisman, Thierry A.G.M.; Soares, Bruno P. [Johns Hopkins University School of Medicine, Division of Pediatric Radiology and Pediatric Neuroradiology, Russell H. Morgan Department of Radiology and Radiological Science, Baltimore, MD (United States); Stafstrom, Carl E. [Johns Hopkins University School of Medicine, Division of Pediatric Neurology, Department of Neurology, Baltimore, MD (United States)

    2018-02-15

    The current classification of malformations of cortical development is based on the type of disrupted embryological process (cell proliferation, migration, or cortical organization/post-migrational development) and the resulting morphological anomalous pattern of findings. An ideal classification would include knowledge of biological pathways. It has recently been demonstrated that alterations affecting the mechanistic target of rapamycin (mTOR) signaling pathway result in diverse abnormalities such as dysplastic megalencephaly, hemimegalencephaly, ganglioglioma, dysplastic cerebellar gangliocytoma, focal cortical dysplasia type IIb, and brain lesions associated with tuberous sclerosis. We review the neuroimaging findings in brain abnormalities related to alterations in the mTOR pathway, following the emerging trend from morphology towards genetics in the classification of malformations of cortical development. This approach improves the understanding of anomalous brain development and allows precise diagnosis and potentially targeted therapies that may regulate mTOR pathway function. (orig.)

  18. Dysplasia and overgrowth. Magnetic resonance imaging of pediatric brain abnormalities secondary to alterations in the mechanistic target of rapamycin pathway

    International Nuclear Information System (INIS)

    Shrot, Shai; Hwang, Misun; Huisman, Thierry A.G.M.; Soares, Bruno P.; Stafstrom, Carl E.

    2018-01-01

    The current classification of malformations of cortical development is based on the type of disrupted embryological process (cell proliferation, migration, or cortical organization/post-migrational development) and the resulting morphological anomalous pattern of findings. An ideal classification would include knowledge of biological pathways. It has recently been demonstrated that alterations affecting the mechanistic target of rapamycin (mTOR) signaling pathway result in diverse abnormalities such as dysplastic megalencephaly, hemimegalencephaly, ganglioglioma, dysplastic cerebellar gangliocytoma, focal cortical dysplasia type IIb, and brain lesions associated with tuberous sclerosis. We review the neuroimaging findings in brain abnormalities related to alterations in the mTOR pathway, following the emerging trend from morphology towards genetics in the classification of malformations of cortical development. This approach improves the understanding of anomalous brain development and allows precise diagnosis and potentially targeted therapies that may regulate mTOR pathway function. (orig.)

  19. ATAD3 proteins: brokers of a mitochondria-endoplasmic reticulum connection in mammalian cells.

    Science.gov (United States)

    Baudier, Jacques

    2018-05-01

    In yeast, a sequence of physical and genetic interactions termed the endoplasmic reticulum (ER)-mitochondria organizing network (ERMIONE) controls mitochondria-ER interactions and mitochondrial biogenesis. Several functions that characterize ERMIONE complexes are conserved in mammalian cells, suggesting that a similar tethering complex must exist in metazoans. Recent studies have identified a new family of nuclear-encoded ATPases associated with diverse cellular activities (AAA+-ATPase) mitochondrial membrane proteins specific to multicellular eukaryotes, called the ATPase family AAA domain-containing protein 3 (ATAD3) proteins (ATAD3A and ATAD3B). These proteins are crucial for normal mitochondrial-ER interactions and lie at the heart of processes underlying mitochondrial biogenesis. ATAD3A orthologues have been studied in flies, worms, and mammals, highlighting the widespread importance of this gene during embryonic development and in adulthood. ATAD3A is a downstream effector of target of rapamycin (TOR) signalling in Drosophila and exhibits typical features of proteins from the ERMIONE-like complex in metazoans. In humans, mutations in the ATAD3A gene represent a new link between altered mitochondrial-ER interaction and recognizable neurological syndromes. The primate-specific ATAD3B protein is a biomarker of pluripotent embryonic stem cells. Through negative regulation of ATAD3A function, ATAD3B supports mitochondrial stemness properties. © 2017 Cambridge Philosophical Society.

  20. Biochemistry of Mitochondria

    Directory of Open Access Journals (Sweden)

    Filiz Koc

    2003-02-01

    Full Text Available Mitochondria are energy source of cells. They have external and internal membranes, cristas and matrix. External membranes consist of specialized transport proteins. They have monoamine oxidase and citokrome-c reductase which both play role in KREBS cycle as catalyst and many enzymes which are necessary for phospholipid and phosphoric acid synthesis. Enzymes of electron transport chain and oxidative phosphorylation are located in the internal membranes. Also, here, there are transport systems for specific substances, such as ATP, ADP, P1, pyruvate, succinate, malate, citrate, and -ketoglutarate . Matrix; having gel-like consistency, contains a large number of enzymes. [Archives Medical Review Journal 2003; 12(0.100: 1-13

  1. GTP-binding-defective ARL4D alters mitochondrial morphology and membrane potential.

    Directory of Open Access Journals (Sweden)

    Chun-Chun Li

    Full Text Available ARL4D, ARL4A, and ARL4C are closely related members of the ADP-ribosylation factor/ARF-like protein (ARF/ARL family of GTPases. All three ARL4 proteins contain nuclear localization signals (NLSs at their C-termini and are primarily found at the plasma membrane, but they are also present in the nucleus and cytoplasm. ARF function and localization depends on their controlled binding and hydrolysis of GTP. Here we show that GTP-binding-defective ARL4D is targeted to the mitochondria, where it affects mitochondrial morphology and function. We found that a portion of endogenous ARL4D and the GTP-binding-defective ARL4D mutant ARL4D(T35N reside in the mitochondria. The N-terminal myristoylation of ARL4D(T35N was required for its localization to mitochondria. The localization of ARL4D(T35N to the mitochondria reduced the mitochondrial membrane potential (ΔΨm and caused mitochondrial fragmentation. Furthermore, the C-terminal NLS region of ARL4D(T35N was required for its effect on the mitochondria. This study is the first to demonstrate that the dysfunctional GTP-binding-defective ARL4D is targeted to mitochondria, where it subsequently alters mitochondrial morphology and membrane potential.

  2. Mitochondria as targets for cancer therapy

    Czech Academy of Sciences Publication Activity Database

    Ralph, S.J.; Neužil, Jiří

    2009-01-01

    Roč. 53, č. 1 (2009), s. 9-28 ISSN 1613-4125 Institutional research plan: CEZ:AV0Z50520701 Keywords : Apoptosis * mitocans * cancer Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.356, year: 2009

  3. Altering spatial priority maps via statistical learning of target selection and distractor filtering.

    Science.gov (United States)

    Ferrante, Oscar; Patacca, Alessia; Di Caro, Valeria; Della Libera, Chiara; Santandrea, Elisa; Chelazzi, Leonardo

    2018-05-01

    The cognitive system has the capacity to learn and make use of environmental regularities - known as statistical learning (SL), including for the implicit guidance of attention. For instance, it is known that attentional selection is biased according to the spatial probability of targets; similarly, changes in distractor filtering can be triggered by the unequal spatial distribution of distractors. Open questions remain regarding the cognitive/neuronal mechanisms underlying SL of target selection and distractor filtering. Crucially, it is unclear whether the two processes rely on shared neuronal machinery, with unavoidable cross-talk, or they are fully independent, an issue that we directly addressed here. In a series of visual search experiments, participants had to discriminate a target stimulus, while ignoring a task-irrelevant salient distractor (when present). We systematically manipulated spatial probabilities of either one or the other stimulus, or both. We then measured performance to evaluate the direct effects of the applied contingent probability distribution (e.g., effects on target selection of the spatial imbalance in target occurrence across locations) as well as its indirect or "transfer" effects (e.g., effects of the same spatial imbalance on distractor filtering across locations). By this approach, we confirmed that SL of both target and distractor location implicitly bias attention. Most importantly, we described substantial indirect effects, with the unequal spatial probability of the target affecting filtering efficiency and, vice versa, the unequal spatial probability of the distractor affecting target selection efficiency across locations. The observed cross-talk demonstrates that SL of target selection and distractor filtering are instantiated via (at least partly) shared neuronal machinery, as further corroborated by strong correlations between direct and indirect effects at the level of individual participants. Our findings are compatible

  4. Butenolide inhibits marine fouling by altering the primary metabolism of three target organisms

    KAUST Repository

    Zhang, Yifan; Zhang, Huoming; He, Lisheng; Liu, Changdong; Xü , Ying; Qian, Peiyuan

    2012-01-01

    Butenolide is a very promising antifouling compound that inhibits ship hull fouling by a variety of marine organisms, but its antifouling mechanism was previously unknown. Here we report the first study of butenolides molecular targets in three

  5. Mitochondria in health and disease

    DEFF Research Database (Denmark)

    Durhuus, Jon Ambæk; Madsen, Claus Desler; Rasmussen, Lene Juel

    2015-01-01

    The primary role of mitochondria was long considered to be production of cellular energy. However, as the understanding of mitochondria in disease is ever expanding, so is their additional function for a healthy organism. Mitochondrial dysfunction is linked to a range of pathologies, including...... (SMRM) was titled "Mitochondria in Health and Disease". The conference was organized by Gayathri N, K Thangaraj, and KK Singh and was held at the National Institute of Mental Health & Neuro Sciences (NIMHANS) in Bangalore, India, from the 19th to 20th of December 2013. The meeting featured...

  6. Zebrafish Get Connected: Investigating Neurotransmission Targets and Alterations in Chemical Toxicity

    Directory of Open Access Journals (Sweden)

    Katharine A. Horzmann

    2016-08-01

    Full Text Available Neurotransmission is the basis of neuronal communication and is critical for normal brain development, behavior, learning, and memory. Exposure to drugs and chemicals can alter neurotransmission, often through unknown pathways and mechanisms. The zebrafish (Danio rerio model system is increasingly being used to study the brain and chemical neurotoxicity. In this review, the major neurotransmitter systems, including glutamate, GABA, dopamine, norepinephrine, serotonin, acetylcholine, histamine, and glutamate are surveyed and pathways of synthesis, transport, metabolism, and action are examined. Differences between human and zebrafish neurochemical pathways are highlighted. We also review techniques for evaluating neurological function, including the measurement of neurotransmitter levels, assessment of gene expression through transcriptomic analysis, and the recording of neurobehavior. Finally examples of chemical toxicity studies evaluating alterations in neurotransmitter systems in the zebrafish model are reviewed.

  7. Linking neocortical, cognitive, and genetic variability in autism with alterations of brain plasticity: the Trigger-Threshold-Target model.

    Science.gov (United States)

    Mottron, Laurent; Belleville, Sylvie; Rouleau, Guy A; Collignon, Olivier

    2014-11-01

    The phenotype of autism involves heterogeneous adaptive traits (strengths vs. disabilities), different domains of alterations (social vs. non-social), and various associated genetic conditions (syndromic vs. nonsyndromic autism). Three observations suggest that alterations in experience-dependent plasticity are an etiological factor in autism: (1) the main cognitive domains enhanced in autism are controlled by the most plastic cortical brain regions, the multimodal association cortices; (2) autism and sensory deprivation share several features of cortical and functional reorganization; and (3) genetic mutations and/or environmental insults involved in autism all appear to affect developmental synaptic plasticity, and mostly lead to its upregulation. We present the Trigger-Threshold-Target (TTT) model of autism to organize these findings. In this model, genetic mutations trigger brain reorganization in individuals with a low plasticity threshold, mostly within regions sensitive to cortical reallocations. These changes account for the cognitive enhancements and reduced social expertise associated with autism. Enhanced but normal plasticity may underlie non-syndromic autism, whereas syndromic autism may occur when a triggering mutation or event produces an altered plastic reaction, also resulting in intellectual disability and dysmorphism in addition to autism. Differences in the target of brain reorganization (perceptual vs. language regions) account for the main autistic subgroups. In light of this model, future research should investigate how individual and sex-related differences in synaptic/regional brain plasticity influence the occurrence of autism. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  8. Connecting Mitochondria, Metabolism, and Stem Cell Fate

    Science.gov (United States)

    Wanet, Anaïs; Arnould, Thierry; Najimi, Mustapha

    2015-01-01

    As sites of cellular respiration and energy production, mitochondria play a central role in cell metabolism. Cell differentiation is associated with an increase in mitochondrial content and activity and with a metabolic shift toward increased oxidative phosphorylation activity. The opposite occurs during reprogramming of somatic cells into induced pluripotent stem cells. Studies have provided evidence of mitochondrial and metabolic changes during the differentiation of both embryonic and somatic (or adult) stem cells (SSCs), such as hematopoietic stem cells, mesenchymal stem cells, and tissue-specific progenitor cells. We thus propose to consider those mitochondrial and metabolic changes as hallmarks of differentiation processes. We review how mitochondrial biogenesis, dynamics, and function are directly involved in embryonic and SSC differentiation and how metabolic and sensing pathways connect mitochondria and metabolism with cell fate and pluripotency. Understanding the basis of the crosstalk between mitochondria and cell fate is of critical importance, given the promising application of stem cells in regenerative medicine. In addition to the development of novel strategies to improve the in vitro lineage-directed differentiation of stem cells, understanding the molecular basis of this interplay could lead to the identification of novel targets to improve the treatment of degenerative diseases. PMID:26134242

  9. Interaction theory of mammalian mitochondria.

    Science.gov (United States)

    Nakada, K; Inoue, K; Hayashi, J

    2001-11-09

    We generated mice with deletion mutant mtDNA by its introduction from somatic cells into mouse zygotes. Expressions of disease phenotypes are limited to tissues expressing mitochondrial dysfunction. Considering that all these mice share the same nuclear background, these observations suggest that accumulation of the mutant mtDNA and resultant expressions of mitochondrial dysfunction are responsible for expression of disease phenotypes. On the other hand, mitochondrial dysfunction and expression of clinical abnormalities were not observed until the mutant mtDNA accumulated predominantly. This protection is due to the presence of extensive and continuous interaction between exogenous mitochondria from cybrids and recipient mitochondria from embryos. Thus, we would like to propose a new hypothesis on mitochondrial biogenesis, interaction theory of mitochondria: mammalian mitochondria exchange genetic contents, and thus lost the individuality and function as a single dynamic cellular unit. Copyright 2001 Academic Press.

  10. Molecular alterations as target for therapy in metastatic osteosarcoma: a review of literature

    NARCIS (Netherlands)

    Posthuma de Boer, J.; Witlox, M.A.; Kaspers, G.J.L.; van Royen, B.J.

    2011-01-01

    Treating metastatic osteosarcoma (OS) remains a challenge in oncology. Current treatment strategies target the primary tumour rather than metastases and have a limited efficacy in the treatment of metastatic disease. Metastatic cells have specific features that render them less sensitive to therapy

  11. Lassa virus infection in experimentally infected marmosets: liver pathology and immunophenotypic alterations in target tissues.

    Science.gov (United States)

    Carrion, Ricardo; Brasky, Kathleen; Mansfield, Keith; Johnson, Curtis; Gonzales, Monica; Ticer, Anysha; Lukashevich, Igor; Tardif, Suzette; Patterson, Jean

    2007-06-01

    Lassa virus causes thousands of deaths annually in western Africa and is considered a potential biological weapon. In an attempt to develop a small nonhuman primate model of Lassa fever, common marmosets were subcutaneously inoculated with Lassa virus strain Josiah. This inoculation resulted in a systemic disease with clinical and morphological features mirroring those in fatal human Lassa infection: fever, weight loss, high viremia and viral RNA load in tissues, elevated liver enzymes, and severe morbidity between days 15 and 20. The most prominent histopathology findings included multifocal hepatic necrosis with mild inflammation and hepatocyte proliferation, lymphoid depletion, and interstitial nephritis. Cellular aggregates in regions of hepatocellular necrosis were largely composed of HAM56-positive macrophages, devoid of CD3-positive and CD20-positive cells, and characterized by marked reductions in the intensity of HLA-DP, DQ, DR staining. A marked reduction in the major histocompatibility complex class II expression was also observed in the lymph nodes. Immunophenotypic alterations in spleen included reductions in overall numbers of CD20-positive and CD3-positive cells and the disruption of lymphoid follicular architecture. These findings identify the common marmoset as an appropriate model of human Lassa fever and present the first experimental evidence that replication of Lassa virus in tissues is associated with alterations that would be expected to impair adaptive immunity.

  12. Targeted molecular profiling of rare genetic alterations in colorectal cancer using next-generation sequencing.

    Science.gov (United States)

    Jauhri, Mayank; Bhatnagar, Akanksha; Gupta, Satish; Shokeen, Yogender; Minhas, Sachin; Aggarwal, Shyam

    2016-10-01

    Mutation frequencies of common genetic alterations in colorectal cancer have been in the spotlight for many years. This study highlights few rare somatic mutations, which possess the attributes of a potential CRC biomarker yet are often neglected. Next-generation sequencing was performed over 112 tumor samples to detect genetic alterations in 31 rare genes in colorectal cancer. Mutations were detected in 26/31 (83.9 %) uncommon genes, which together contributed toward 149 gene mutations in 67/112 (59.8 %) colorectal cancer patients. The most frequent mutations include KDR (19.6 %), PTEN (17 %), FBXW7 (10.7 %), SMAD4 (10.7 %), VHL (8 %), KIT (8 %), MET (7.1 %), ATM (6.3 %), CTNNB1 (4.5 %) and CDKN2A (4.5 %). RB1, ERBB4 and ERBB2 mutations were persistent in 3.6 % patients. GNAS, FGFR2 and FGFR3 mutations were persistent in 1.8 % patients. Ten genes (EGFR, NOTCH1, SMARCB1, ABL1, STK11, SMO, RET, GNAQ, CSF1R and FLT3) were found mutated in 0.9 % patients. Lastly, no mutations were observed in AKT, HRAS, MAP2K1, PDGFR and JAK2. Significant associations were observed between VHL with tumor site, ERBB4 and SMARCB1 with tumor invasion, CTNNB1 with lack of lymph node involvement and CTNNB1, FGFR2 and FGFR3 with TNM stage. Significantly coinciding mutation pairs include PTEN and SMAD4, PTEN and KDR, EGFR and RET, EGFR and RB1, FBXW7 and CTNNB1, KDR and FGFR2, FLT3 and CTNNB1, RET and RB1, ATM and SMAD4, ATM and CDKN2A, ERBB4 and SMARCB1. This study elucidates few potential colorectal cancer biomarkers, specifically KDR, PTEN, FBXW7 and SMAD4, which are found mutated in more than 10 % patients.

  13. Epigenetically altered miR-193b targets cyclin D1 in prostate cancer

    International Nuclear Information System (INIS)

    Kaukoniemi, Kirsi M; Rauhala, Hanna E; Scaravilli, Mauro; Latonen, Leena; Annala, Matti; Vessella, Robert L; Nykter, Matti; Tammela, Teuvo L J; Visakorpi, Tapio

    2015-01-01

    Micro-RNAs (miRNA) are important regulators of gene expression and often differentially expressed in cancer and other diseases. We have previously shown that miR-193b is hypermethylated in prostate cancer (PC) and suppresses cell growth. It has been suggested that miR-193b targets cyclin D1 in several malignancies. Here, our aim was to determine if miR-193b targets cyclin D1 in prostate cancer. Our data show that miR-193b is commonly methylated in PC samples compared to benign prostate hyperplasia. We found reduced miR-193b expression (P < 0.05) in stage pT3 tumors compared to pT2 tumors in a cohort of prostatectomy specimens. In 22Rv1 PC cells with low endogenous miR-193b expression, the overexpression of miR-193b reduced CCND1mRNA levels and cyclin D1 protein levels. In addition, the exogenous expression of miR-193b decreased the phosphorylation level of RB, a target of the cyclin D1-CDK4/6 pathway. Moreover, according to a reporter assay, miR-193b targeted the 3’UTR of CCND1 in PC cells and the CCND1 activity was rescued by expressing CCND1 lacking its 3’UTR. Immunohistochemical analysis of cyclin D1 showed that castration-resistant prostate cancers have significantly (P = 0.0237) higher expression of cyclin D1 compared to hormone-naïve cases. Furthermore, the PC cell lines 22Rv1 and VCaP, which express low levels of miR-193b and high levels of CCND1, showed significant growth retardation when treated with a CDK4/6 inhibitor. In contrast, the inhibitor had no effect on the growth of PC-3 and DU145 cells with high miR-193b and low CCND1 expression. Taken together, our data demonstrate that miR-193b targets cyclin D1 in prostate cancer

  14. RECQL4 localizes to mitochondria and preserves mitochondrial DNA integrity

    DEFF Research Database (Denmark)

    Croteau, Deborah L; Rossi, Marie L; Canugovi, Chandrika

    2012-01-01

    in premature aging. There is no information about whether any of the RecQ helicases play roles in mitochondrial biogenesis, which is strongly implicated in the aging process. Here, we used microscopy to visualize RECQL4 in mitochondria. Fractionation of human and mouse cells also showed that RECQL4 was present...... in mitochondria. Q-PCR amplification of mitochondrial DNA demonstrated that mtDNA damage accumulated in RECQL4-deficient cells. Microarray analysis suggested that mitochondrial bioenergetic pathways might be affected in RTS. Measurements of mitochondrial bioenergetics showed a reduction in the mitochondrial......Q helicase to be found in both human and mouse mitochondria, and the loss of RECQL4 alters mitochondrial integrity....

  15. Fluoxetine and the mitochondria: A review of the toxicological aspects.

    Science.gov (United States)

    de Oliveira, Marcos Roberto

    2016-09-06

    Fluoxetine (a selective serotonin reuptake inhibitor (SSRI)) is used as an antidepressant by modulating the levels of serotonin in the synaptic cleft. Nevertheless, fluoxetine also induces undesirable effects, such as anxiety, sexual dysfunction, sleep disturbances, and gastrointestinal impairments. Fluoxetine has been viewed as an agent that may interfere with cell fate by triggering apoptosis. On the other hand, fluoxetine intake has been associated with increased cancer risk. Nonetheless, data remain contradictory and no conclusions were taken. Several studies demonstrated that fluoxetine interacts with mitochondria triggering apoptosis and/or altering mitochondrial function by modulating the activity of respiratory chain components and enzymes of the Krebs cycle. Furthermore, fluoxetine affects mitochondria-related redox parameters in different experimental models. In this review, data demonstrating the effects of fluoxetine upon mammalian mitochondria are described and discussed, as well as several unsolved questions in this field of research are addressed. A separate section deals with future needs regarding the research involving the impact of fluoxetine treatment upon mitochondria and mitochondria-related signaling. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  16. Butenolide inhibits marine fouling by altering the primary metabolism of three target organisms

    KAUST Repository

    Zhang, Yifan

    2012-06-15

    Butenolide is a very promising antifouling compound that inhibits ship hull fouling by a variety of marine organisms, but its antifouling mechanism was previously unknown. Here we report the first study of butenolides molecular targets in three representative fouling organisms. In the barnacle Balanus (=Amphibalanus) amphitrite, butenolide bound to acetyl-CoA acetyltransferase 1 (ACAT1), which is involved in ketone body metabolism. Both the substrate and the product of ACAT1 increased larval settlement under butenolide treatment, suggesting its functional involvement. In the bryozoan Bugula neritina, butenolide bound to very long chain acyl-CoA dehydrogenase (ACADVL), actin, and glutathione S-transferases (GSTs). ACADVL is the first enzyme in the very long chain fatty acid β-oxidation pathway. The inhibition of this primary pathway for energy production in larvae by butenolide was supported by the finding that alternative energy sources (acetoacetate and pyruvate) increased larval attachment under butenolide treatment. In marine bacterium Vibrio sp. UST020129-010, butenolide bound to succinyl-CoA synthetase β subunit (SCSβ) and inhibited bacterial growth. ACAT1, ACADVL, and SCSβ are all involved in primary metabolism for energy production. These findings suggest that butenolide inhibits fouling by influencing the primary metabolism of target organisms. © 2012 American Chemical Society.

  17. Basolateral cholesterol depletion alters Aquaporin-2 post-translational modifications and disrupts apical plasma membrane targeting.

    Science.gov (United States)

    Moeller, Hanne B; Fuglsang, Cecilia Hvitfeldt; Pedersen, Cecilie Nøhr; Fenton, Robert A

    2018-01-01

    Apical plasma membrane accumulation of the water channel Aquaporin-2 (AQP2) in kidney collecting duct principal cells is critical for body water homeostasis. Posttranslational modification (PTM) of AQP2 is important for regulating AQP2 trafficking. The aim of this study was to determine the role of cholesterol in regulation of AQP2 PTM and in apical plasma membrane targeting of AQP2. Cholesterol depletion from the basolateral plasma membrane of a collecting duct cell line (mpkCCD14) using methyl-beta-cyclodextrin (MBCD) increased AQP2 ubiquitylation. Forskolin, cAMP or dDAVP-mediated AQP2 phosphorylation at Ser269 (pS269-AQP2) was prevented by cholesterol depletion from the basolateral membrane. None of these effects on pS269-AQP2 were observed when cholesterol was depleted from the apical side of cells, or when MBCD was applied subsequent to dDAVP stimulation. Basolateral, but not apical, MBCD application prevented cAMP-induced apical plasma membrane accumulation of AQP2. These studies indicate that manipulation of the cholesterol content of the basolateral plasma membrane interferes with AQP2 PTM and subsequently regulated apical plasma membrane targeting of AQP2. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Protonmotive force in muscle mitochondria

    International Nuclear Information System (INIS)

    Stumpf, D.A.; Haas, R.; Eguren, L.A.; Parks, J.K.; Eilert, R.E.

    1982-01-01

    The protonmotive force (delta p) of muscle mitochondria was measured by estimating the distribution of 14C-labeled TPMP (trimethylphenylphosphonium iodide) and 14C-labeled acetate across the inner membrane of muscle mitochondria. The matrix volume was simultaneously determined using 3H-labeled H2O and 3H-labeled mannitol and repeated drying to distinguish the label in these 2 compounds. Rapid separation of mitochondria from the incubation medium by centrifugation through silicone oil avoids the problems of potential anaerobic conditions associated with conventional centrifugation and large volumes of trapped media associated with filtration. The value for delta p (mean +/- SD) was 192+/- 26 mV in 30 determinations with rat muscle mitochondria during state 4. Measurement of oxygen consumption allowed calculation of membrane conductance (Cm,H+) which was 0.49 +/- 0.18 nmol of H+/min/mg protein/mV. The values for delta p and Cm,H+ are reported for a variety of experimental conditions and are consistent with Mitchell's chemiosmotic theory. Biopsy specimens obtained from human muscle gave state-4 delta p values of 197+/- 30 mV (n .5) and Cm,H+ values of 0.52 +/- 0.12 nmol of H+/min/mg/mV (n . 4). This delta p assay is the first described for coupled mammalian muscle mitochondria and will be useful in assessing membrane function

  19. Alteration of SHP-1/p-STAT3 Signaling: A Potential Target for Anticancer Therapy

    Directory of Open Access Journals (Sweden)

    Tzu-Ting Huang

    2017-06-01

    Full Text Available The Src homology 2 (SH2 domain-containing protein tyrosine phosphatase 1 (SHP-1, a non-receptor protein tyrosine phosphatase, has been reported as a negative regulator of phosphorylated signal transducer and activator of transcription 3 (STAT3 and linked to tumor development. In this present review, we will discuss the importance and function of SHP-1/p-STAT3 signaling in nonmalignant conditions as well as malignancies, its cross-talk with other pathways, the current clinical development and the potential role of inhibitors of this pathway in anticancer therapy and clinical relevance of SHP-1/p-STAT3 in cancers. Lastly, we will summarize and highlight work involving novel drugs/compounds targeting SHP-1/p-STAT3 signaling and combined strategies that were/are discovered in our and our colleagues’ laboratories.

  20. Retinoschisislike alterations in the mouse eye caused by gene targeting of the Norrie disease gene.

    Science.gov (United States)

    Ruether, K; van de Pol, D; Jaissle, G; Berger, W; Tornow, R P; Zrenner, E

    1997-03-01

    To investigate the retinal function and morphology of mice carrying a replacement mutation in exon 2 of the Norrie disease gene. Recently, Norrie disease mutant mice have been generated using gene targeting technology. The mutation removes the 56 N-terminal amino acids of the Norrie gene product. Ganzfeld electroretinograms (ERGs) were obtained in five animals hemizygous or homozygous for the mutant gene and in three female animals heterozygous for the mutant gene. As controls, three males carrying the wild-type gene were examined. Electroretinogram testing included rod a- and b-wave V-log I functions, oscillatory potentials, and cone responses. The fundus morphology has been visualized by scanning laser ophthalmoscopy. Rod and cone ERG responses and fundus morphology were not significantly different among female heterozygotes and wild-type mice. In contrast, the hemizygous mice displayed a severe loss of ERG b-wave, leading to a negatively shaped scotopic ERG and a marked reduction of oscillatory potentials. The a-wave was normal at low intensities, and only with brighter flashes was there a moderate amplitude loss. Cone amplitudes were barely recordable in the gene-targeted males. Ophthalmoscopy revealed snowflakelike vitreal changes, retinoschisis, and pigment epithelium irregularities in hemizygotes and homozygotes, but no changes in female heterozygotes. The negatively shaped scotopic ERG in male mice with a Norrie disease gene mutation probably was caused by retinoschisis. Pigment epithelial changes and degenerations of the outer retina are relatively mild. These findings may be a clue to the embryonal retinoschisislike pathogenesis of Norrie disease in humans or it may indicate a different expression of the Norrie disease gene defect in mice compared to that in humans.

  1. Aprataxin localizes to mitochondria and preserves mitochondrial function

    DEFF Research Database (Denmark)

    Sykora, Peter; Croteau, Deborah L; Bohr, Vilhelm A

    2011-01-01

    aborted ligation reactions. We report herein that aprataxin localizes to mitochondria in human cells and we identify an N-terminal amino acid sequence that targets certain isoforms of the protein to this intracellular compartment. We also show that transcripts encoding this unique N-terminal stretch...

  2. Verbal instructions targeting valence alter negative conditional stimulus evaluations (but do not affect reinstatement rates).

    Science.gov (United States)

    Luck, Camilla C; Lipp, Ottmar V

    2018-02-01

    Negative conditional stimulus (CS) valence acquired during fear conditioning may enhance fear relapse and is difficult to remove as it extinguishes slowly and does not respond to the instruction that unconditional stimulus (US) presentations will cease. We examined whether instructions targeting CS valence would be more effective. In Experiment 1, an image of one person (CS+) was paired with an aversive US, while another (CS-) was presented alone. After acquisition, participants were given positive information about the CS+ poser and negative information about the CS- poser. Instructions reversed the pattern of differential CS valence present during acquisition and eliminated differential electrodermal responding. In Experiment 2, we compared positive and negative CS revaluation by providing positive/negative information about the CS+ and neutral information about CS-. After positive revaluation, differential valence was removed and differential electrodermal responding remained intact. After negative revaluation, differential valence was strengthened and differential electrodermal responding was eliminated. Unexpectedly, the instructions did not affect the reinstatement of differential electrodermal responding.

  3. Gene introduction into the mitochondria of Arabidopsis thaliana via peptide-based carriers

    Science.gov (United States)

    Chuah, Jo-Ann; Yoshizumi, Takeshi; Kodama, Yutaka; Numata, Keiji

    2015-01-01

    Available methods in plant genetic transformation are nuclear and plastid transformations because similar procedures have not yet been established for the mitochondria. The double membrane and small size of the organelle, in addition to its large population in cells, are major obstacles in mitochondrial transfection. Here we report the intracellular delivery of exogenous DNA localized to the mitochondria of Arabidopsis thaliana using a combination of mitochondria-targeting peptide and cell-penetrating peptide. Low concentrations of peptides were sufficient to deliver DNA into the mitochondria and expression of imported DNA reached detectable levels within a short incubation period (12 h). We found that electrostatic interaction with the cell membrane is not a critical factor for complex internalization, instead, improved intracellular penetration of mitochondria-targeted complexes significantly enhanced gene transfer efficiency. Our results delineate a simple and effective peptide-based method, as a starting point for the development of more sophisticated plant mitochondrial transfection strategies.

  4. Altered surfactant homeostasis and recurrent respiratory failure secondary to TTF-1 nuclear targeting defect.

    Science.gov (United States)

    Peca, Donatella; Petrini, Stefania; Tzialla, Chryssoula; Boldrini, Renata; Morini, Francesco; Stronati, Mauro; Carnielli, Virgilio P; Cogo, Paola E; Danhaive, Olivier

    2011-08-25

    Mutations of genes affecting surfactant homeostasis, such as SFTPB, SFTPC and ABCA3, lead to diffuse lung disease in neonates and children. Haploinsufficiency of NKX2.1, the gene encoding the thyroid transcription factor-1 (TTF-1)--critical for lung, thyroid and central nervous system morphogenesis and function--causes a rare form of progressive respiratory failure designated brain-lung-thyroid syndrome. Molecular mechanisms involved in this syndrome are heterogeneous and poorly explored. We report a novel TTF-1 molecular defect causing recurrent respiratory failure episodes in an infant. The subject was an infant with severe neonatal respiratory distress syndrome followed by recurrent respiratory failure episodes, hypopituitarism and neurological abnormalities. Lung histology and ultrastructure were assessed by surgical biopsy. Surfactant-related genes were studied by direct genomic DNA sequencing and array chromatine genomic hybridization (aCGH). Surfactant protein expression in lung tissue was analyzed by confocal immunofluorescence microscopy. For kinetics studies, surfactant protein B and disaturated phosphatidylcholine (DSPC) were isolated from serial tracheal aspirates after intravenous administration of stable isotope-labeled (2)H(2)O and (13)C-leucine; fractional synthetic rate was derived from gas chromatography/mass spectrometry (2)H and (13)C enrichment curves. Six intubated infants with no primary lung disease were used as controls. Lung biopsy showed desquamative interstitial pneumonitis and lamellar body abnormalities suggestive of genetic surfactant deficiency. Genetic studies identified a heterozygous ABCA3 mutation, L941P, previously unreported. No SFTPB, SFTPC or NKX2.1 mutations or deletions were found. However, immunofluorescence studies showed TTF-1 prevalently expressed in type II cell cytoplasm instead of nucleus, indicating defective nuclear targeting. This pattern has not been reported in human and was not found in two healthy controls and

  5. Altered surfactant homeostasis and recurrent respiratory failure secondary to TTF-1 nuclear targeting defect

    Directory of Open Access Journals (Sweden)

    Carnielli Virgilio P

    2011-08-01

    Full Text Available Abstract Background Mutations of genes affecting surfactant homeostasis, such as SFTPB, SFTPC and ABCA3, lead to diffuse lung disease in neonates and children. Haploinsufficiency of NKX2.1, the gene encoding the thyroid transcription factor-1 (TTF-1 - critical for lung, thyroid and central nervous system morphogenesis and function - causes a rare form of progressive respiratory failure designated brain-lung-thyroid syndrome. Molecular mechanisms involved in this syndrome are heterogeneous and poorly explored. We report a novel TTF-1 molecular defect causing recurrent respiratory failure episodes in an infant. Methods The subject was an infant with severe neonatal respiratory distress syndrome followed by recurrent respiratory failure episodes, hypopituitarism and neurological abnormalities. Lung histology and ultrastructure were assessed by surgical biopsy. Surfactant-related genes were studied by direct genomic DNA sequencing and array chromatine genomic hybridization (aCGH. Surfactant protein expression in lung tissue was analyzed by confocal immunofluorescence microscopy. For kinetics studies, surfactant protein B and disaturated phosphatidylcholine (DSPC were isolated from serial tracheal aspirates after intravenous administration of stable isotope-labeled 2H2O and 13C-leucine; fractional synthetic rate was derived from gas chromatography/mass spectrometry 2H and 13C enrichment curves. Six intubated infants with no primary lung disease were used as controls. Results Lung biopsy showed desquamative interstitial pneumonitis and lamellar body abnormalities suggestive of genetic surfactant deficiency. Genetic studies identified a heterozygous ABCA3 mutation, L941P, previously unreported. No SFTPB, SFTPC or NKX2.1 mutations or deletions were found. However, immunofluorescence studies showed TTF-1 prevalently expressed in type II cell cytoplasm instead of nucleus, indicating defective nuclear targeting. This pattern has not been reported in human

  6. Role of accelerated segment switch in exons to alter targeting (ASSET in the molecular evolution of snake venom proteins

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    Kini R Manjunatha

    2009-06-01

    Full Text Available Abstract Background Snake venom toxins evolve more rapidly than other proteins through accelerated changes in the protein coding regions. Previously we have shown that accelerated segment switch in exons to alter targeting (ASSET might play an important role in its functional evolution of viperid three-finger toxins. In this phenomenon, short sequences in exons are radically changed to unrelated sequences and hence affect the folding and functional properties of the toxins. Results Here we analyzed other snake venom protein families to elucidate the role of ASSET in their functional evolution. ASSET appears to be involved in the functional evolution of three-finger toxins to a greater extent than in several other venom protein families. ASSET leads to replacement of some of the critical amino acid residues that affect the biological function in three-finger toxins as well as change the conformation of the loop that is involved in binding to specific target sites. Conclusion ASSET could lead to novel functions in snake venom proteins. Among snake venom serine proteases, ASSET contributes to changes in three surface segments. One of these segments near the substrate binding region is known to affect substrate specificity, and its exchange may have significant implications for differences in isoform catalytic activity on specific target protein substrates. ASSET therefore plays an important role in functional diversification of snake venom proteins, in addition to accelerated point mutations in the protein coding regions. Accelerated point mutations lead to fine-tuning of target specificity, whereas ASSET leads to large-scale replacement of multiple functionally important residues, resulting in change or gain of functions.

  7. Vaccination targeting human HER3 alters the phenotype of infiltrating T cells and responses to immune checkpoint inhibition.

    Science.gov (United States)

    Osada, Takuya; Morse, Michael A; Hobeika, Amy; Diniz, Marcio A; Gwin, William R; Hartman, Zachary; Wei, Junping; Guo, Hongtao; Yang, Xiao-Yi; Liu, Cong-Xiao; Kaneko, Kensuke; Broadwater, Gloria; Lyerly, H Kim

    2017-01-01

    Expression of human epidermal growth factor family member 3 (HER3), a critical heterodimerization partner with EGFR and HER2, promotes more aggressive biology in breast and other epithelial malignancies. As such, inhibiting HER3 could have broad applicability to the treatment of EGFR- and HER2-driven tumors. Although lack of a functional kinase domain limits the use of receptor tyrosine kinase inhibitors, HER3 contains antigenic targets for T cells and antibodies. Using novel human HER3 transgenic mouse models of breast cancer, we demonstrate that immunization with recombinant adenoviral vectors encoding full length human HER3 (Ad-HER3-FL) induces HER3-specific T cells and antibodies, alters the T cell infiltrate in tumors, and influences responses to immune checkpoint inhibitions. Both preventative and therapeutic Ad-HER3-FL immunization delayed tumor growth but were associated with both intratumoral PD-1 expressing CD8 + T cells and regulatory CD4 + T cell infiltrates. Immune checkpoint inhibition with either anti-PD-1 or anti-PD-L1 antibodies increased intratumoral CD8 + T cell infiltration and eliminated tumor following preventive vaccination with Ad-HER3-FL vaccine. The combination of dual PD-1/PD-L1 and CTLA4 blockade slowed the growth of tumor in response to Ad-HER3-FL in the therapeutic model. We conclude that HER3-targeting vaccines activate HER3-specific T cells and induce anti-HER3 specific antibodies, which alters the intratumoral T cell infiltrate and responses to immune checkpoint inhibition.

  8. Fibroblast growth factor receptor (FGFR) alterations in squamous differentiated bladder cancer: a putative therapeutic target for a small subgroup.

    Science.gov (United States)

    Baldia, Philipp H; Maurer, Angela; Heide, Timon; Rose, Michael; Stoehr, Robert; Hartmann, Arndt; Williams, Sarah V; Knowles, Margaret A; Knuechel, Ruth; Gaisa, Nadine T

    2016-11-01

    Although drugable fibroblast growth factor receptor (FGFR) alterations in squamous cell carcinomas (SCC) of various entities are well known, little is known about FGFR modifications in squamous differentiated bladder cancer. Therefore, our study evaluated FGFR1-3 alterations as a putative therapeutic target in this subgroup. We analyzed 73 squamous differentiated bladder cancers (n = 10 pT2, n = 55 pT3, n = 8 pT4) for FGFR1-3 protein expression, FGFR1-3 copy number variations, FGFR3 chromosomal rearrangements (fluorescence in situ hybridization (FISH)) and FGFR3 mutations (SNapShot analysis). Only single cases displayed enhanced protein expression, most frequently FGFR3 overexpression (9.4% (6/64)). FISH showed no amplifications of FGFR1, 2 or 3. Break apart events were only slightly above the cut off in 12.1% (8/66) of cases and no FGFR3-TACC3 rearrangements could be proven by qPCR. FGFR3 mutations (p.S249C) were found in 8.5% (6/71) of tumors and were significantly associated with FGFR3 protein overexpression (p bladder cancer (n = 85), which revealed reduced overall expression of FGFR1 and FGFR2 in tumors compared to normal tissue, while expression of FGFR3 remained high. In the TCGA "squamous-like" subtype FGFR3 mutations were found in 4.9% and correlated with high FGFR3 RNA expression. Mutations of FGFR1 and FGFR2 were less frequent (2.4% and 1.2%). Hence, our comprehensive study provides novel insights into a subgroup of squamous differentiated bladder tumors that hold clues for novel therapeutic regimens and may benefit from FGFR3-targeted therapies.

  9. LKB1 Regulates Mitochondria-Dependent Presynaptic Calcium Clearance and Neurotransmitter Release Properties at Excitatory Synapses along Cortical Axons.

    Science.gov (United States)

    Kwon, Seok-Kyu; Sando, Richard; Lewis, Tommy L; Hirabayashi, Yusuke; Maximov, Anton; Polleux, Franck

    2016-07-01

    Individual synapses vary significantly in their neurotransmitter release properties, which underlie complex information processing in neural circuits. Presynaptic Ca2+ homeostasis plays a critical role in specifying neurotransmitter release properties, but the mechanisms regulating synapse-specific Ca2+ homeostasis in the mammalian brain are still poorly understood. Using electrophysiology and genetically encoded Ca2+ sensors targeted to the mitochondrial matrix or to presynaptic boutons of cortical pyramidal neurons, we demonstrate that the presence or absence of mitochondria at presynaptic boutons dictates neurotransmitter release properties through Mitochondrial Calcium Uniporter (MCU)-dependent Ca2+ clearance. We demonstrate that the serine/threonine kinase LKB1 regulates MCU expression, mitochondria-dependent Ca2+ clearance, and thereby, presynaptic release properties. Re-establishment of MCU-dependent mitochondrial Ca2+ uptake at glutamatergic synapses rescues the altered neurotransmitter release properties characterizing LKB1-null cortical axons. Our results provide novel insights into the cellular and molecular mechanisms whereby mitochondria control neurotransmitter release properties in a bouton-specific way through presynaptic Ca2+ clearance.

  10. Regulation of Endoplasmic Reticulum–Mitochondria Ca2+ Transfer and Its Importance for Anti-Cancer Therapies

    Directory of Open Access Journals (Sweden)

    Gaia Pedriali

    2017-08-01

    Full Text Available Inter-organelle membrane contact sites are emerging as major sites for the regulation of intracellular Ca2+ concentration and distribution. Here, extracellular stimuli operate on a wide array of channels, pumps, and ion exchangers to redistribute intracellular Ca2+ among several compartments. The resulting highly defined spatial and temporal patterns of Ca2+ movement can be used to elicit specific cellular responses, including cell proliferation, migration, or death. Plasma membrane (PM also can directly contact mitochondria and endoplasmic reticulum (ER through caveolae, small invaginations of the PM that ensure inter-organelle contacts, and can contribute to the regulation of numerous cellular functions through scaffolding proteins such as caveolins. PM and ER organize specialized junctions. Here, many components of the receptor-dependent Ca2+ signals are clustered, including the ORAI1-stromal interaction molecule 1 complex. This complex constitutes a primary mechanism for Ca2+ entry into non-excitable cells, modulated by intracellular Ca2+. Several contact sites between the ER and mitochondria, termed mitochondria-associated membranes, show a very complex and specialized structure and host a wide number of proteins that regulate Ca2+ transfer. In this review, we summarize current knowledge of the particular action of several oncogenes and tumor suppressors at these specialized check points and analyze anti-cancer therapies that specifically target Ca2+ flow at the inter-organelle contacts to alter the metabolism and fate of the cancer cell.

  11. Immobilization of Mitochondria on Graphene

    Science.gov (United States)

    2013-08-29

    poly-L-lysine has also been reported for immobilization of yeast mitochondria. Coating was performed by repetitive washing of cover slips with 0.02...of Poly-L-lysine Applications of PLL PLL is a production of bacterial fermentation and is used as a food preservative. In biology, PLL is used in

  12. Mitochondria in aging cell differentiation

    Czech Academy of Sciences Publication Activity Database

    Palková, Zdena; Váchová, Libuše

    2016-01-01

    Roč. 8, č. 7 (2016), s. 1287-1288 ISSN 1945-4589 R&D Projects: GA MŠk(CZ) ED1.1.00/02.0109 Institutional support: RVO:61388971 Keywords : mitochondria * cell differentiation * retrograde signaling Subject RIV: EE - Microbiology, Virology Impact factor: 4.867, year: 2016

  13. Prediction of Chlamydia pneumoniae protein localization in host mitochondria and cytoplasm and possible involvements in lung cancer etiology: a computational approach

    Directory of Open Access Journals (Sweden)

    Aws Alshamsan

    2017-12-01

    Full Text Available Collecting evidence suggests that the intercellular infection of Chlamydia pneumoniae in lungs contributes to the etiology of lung cancer. Many proteins of Chlamydia pneumoniae outmanoeuvre the various system of the host. The infection may regulate various factors, which can influence the growth of lung cancer in affected persons. In this in-silico study, we predict potential targeting of Chlamydia pneumoniae proteins in mitochondrial and cytoplasmic comportments of host cell and their possible involvement in growth and development of lung cancer. Various cellular activities are controlled in mitochondria and cytoplasm, where the localization of Chlamydia pneumoniae proteins may alter the normal functioning of host cells. The rationale of this study is to find out and explain the connection between Chlamydia pneumoniae infection and lung cancer. A sum of 183 and 513 proteins were predicted to target in mitochondria and cytoplasm of host cell out of total 1112 proteins of Chlamydia pneumoniae. In particular, many targeted proteins may interfere with normal growth behaviour of host cells, thereby altering the decision of program cell death. Present article provides a potential connection of Chlamydia pneumoniae protein targeting and proposed that various targeted proteins may play crucial role in lung cancer etiology through diverse mechanisms.

  14. Mitochondrial dysfunction in brain cortex mitochondria of STZ-diabetic rats: effect of l-Arginine.

    Science.gov (United States)

    Ortiz, M Del Carmen; Lores-Arnaiz, Silvia; Albertoni Borghese, M Florencia; Balonga, Sabrina; Lavagna, Agustina; Filipuzzi, Ana Laura; Cicerchia, Daniela; Majowicz, Monica; Bustamante, Juanita

    2013-12-01

    Mitochondrial dysfunction has been implicated in many diseases, including diabetes. It is well known that oxygen free radical species are produced endogenously by mitochondria, and also nitric oxide (NO) by nitric oxide synthases (NOS) associated to mitochondrial membranes, in consequence these organelles constitute main targets for oxidative damage. The aim of this study was to analyze mitochondrial physiology and NO production in brain cortex mitochondria of streptozotocin (STZ) diabetic rats in an early stage of diabetes and the potential effect of L-arginine administration. The diabetic condition was characterized by a clear hyperglycaemic state with loose of body weight after 4 days of STZ injection. This hyperglycaemic state was associated with mitochondrial dysfunction that was evident by an impairment of the respiratory activity, increased production of superoxide anion and a clear mitochondrial depolarization. In addition, the alteration in mitochondrial physiology was associated with a significant decrease in both NO production and nitric oxide synthase type I (NOS I) expression associated to the mitochondrial membranes. An increased level of thiobarbituric acid-reactive substances (TBARS) in brain cortex homogenates from STZ-diabetic rats indicated the presence of lipid peroxidation. L-arginine treatment to diabetic rats did not change blood glucose levels but significantly ameliorated the oxidative stress evidenced by lower TBARS and a lower level of superoxide anion. This effect was paralleled by improvement of mitochondrial respiratory function and a partial mitochondrial repolarization.In addition, the administration of L-arginine to diabetic rats prevented the decrease in NO production and NOSI expression. These results could indicate that exogenously administered L-arginine may have beneficial effects on mitochondrial function, oxidative stress and NO production in brain cortex mitochondria of STZ-diabetic rats.

  15. Respiration and substrate transport rates as well as reactive oxygen species production distinguish mitochondria from brain and liver.

    Science.gov (United States)

    Gusdon, Aaron M; Fernandez-Bueno, Gabriel A; Wohlgemuth, Stephanie; Fernandez, Jenelle; Chen, Jing; Mathews, Clayton E

    2015-09-10

    Aberrant mitochondrial function, including excessive reactive oxygen species (ROS) production, has been implicated in the pathogenesis of human diseases. The use of mitochondrial inhibitors to ascertain the sites in the electron transport chain (ETC) resulting in altered ROS production can be an important tool. However, the response of mouse mitochondria to ETC inhibitors has not been thoroughly assessed. Here we set out to characterize the differences in phenotypic response to ETC inhibitors between the more energetically demanding brain mitochondria and less energetically demanding liver mitochondria in commonly utilized C57BL/6J mice. We show that in contrast to brain mitochondria, inhibiting distally within complex I or within complex III does not increase liver mitochondrial ROS production supported by complex I substrates, and liver mitochondrial ROS production supported by complex II substrates occurred primarily independent of membrane potential. Complex I, II, and III enzymatic activities and membrane potential were equivalent between liver and brain and responded to ETC. inhibitors similarly. Brain mitochondria exhibited an approximately two-fold increase in complex I and II supported respiration compared with liver mitochondria while exhibiting similar responses to inhibitors. Elevated NADH transport and heightened complex II-III coupled activity accounted for increased complex I and II supported respiration, respectively in brain mitochondria. We conclude that important mechanistic differences exist between mouse liver and brain mitochondria and that mouse mitochondria exhibit phenotypic differences compared with mitochondria from other species.

  16. Targeted sequencing identifies genetic alterations that confer primary resistance to EGFR tyrosine kinase inhibitor (Korean Lung Cancer Consortium).

    Science.gov (United States)

    Lim, Sun Min; Kim, Hye Ryun; Cho, Eun Kyung; Min, Young Joo; Ahn, Jin Seok; Ahn, Myung-Ju; Park, Keunchil; Cho, Byoung Chul; Lee, Ji-Hyun; Jeong, Hye Cheol; Kim, Eun Kyung; Kim, Joo-Hang

    2016-06-14

    Non-small-cell lung cancer (NSCLC) patients with activating epidermal growth factor receptor (EGFR) mutations may exhibit primary resistance to EGFR tyrosine kinase inhibitor (TKI). We aimed to examine genomic alterations associated with de novo resistance to gefitinib in a prospective study of NSCLC patients. One-hundred and fifty two patients with activating EGFR mutations were included in this study and 136 patients' tumor sample were available for targeted sequencing of genomic alterations in 22 genes using the Colon and Lung Cancer panel (Ampliseq, Life Technologies). All 132 patients with EGFR mutation were treated with gefitinib for their treatment of advanced NSCLC. Twenty patients showed primary resistance to EGFR TKI, and were classified as non-responders. A total of 543 somatic single-nucleotide variants (498 missense, 13 nonsense) and 32 frameshift insertions/deletions, with a median of 3 mutations per sample. TP53 was most commonly mutated (47%) and mutations in SMAD4 was also common (19%), as well as DDR2 (16%), PIK3CA (15%), STK11 (14%), and BRAF (7%). Genomic mutations in the PI3K/Akt/mTOR pathway were commonly found in non-responders (45%) compared to responders (27%), and they had significantly shorter progression-free survival and overall survival compared to patients without mutations (2.1 vs. 12.8 months, P=0.04, 15.7 vs. not reached, PAkt/mTOR pathway were commonly identified in non-responders and may confer resistance to EGFR TKI. Screening lung adenocarcinoma patients with clinical cancer gene test may aid in selecting out those who show primary resistance to EGFR TKI (NCT01697163).

  17. Targeted capture massively parallel sequencing analysis of LCIS and invasive lobular cancer: Repertoire of somatic genetic alterations and clonal relationships.

    Science.gov (United States)

    Sakr, Rita A; Schizas, Michail; Carniello, Jose V Scarpa; Ng, Charlotte K Y; Piscuoglio, Salvatore; Giri, Dilip; Andrade, Victor P; De Brot, Marina; Lim, Raymond S; Towers, Russell; Weigelt, Britta; Reis-Filho, Jorge S; King, Tari A

    2016-02-01

    Lobular carcinoma in situ (LCIS) has been proposed as a non-obligate precursor of invasive lobular carcinoma (ILC). Here we sought to define the repertoire of somatic genetic alterations in pure LCIS and in synchronous LCIS and ILC using targeted massively parallel sequencing. DNA samples extracted from microdissected LCIS, ILC and matched normal breast tissue or peripheral blood from 30 patients were subjected to massively parallel sequencing targeting all exons of 273 genes, including the genes most frequently mutated in breast cancer and DNA repair-related genes. Single nucleotide variants and insertions and deletions were identified using state-of-the-art bioinformatics approaches. The constellation of somatic mutations found in LCIS (n = 34) and ILC (n = 21) were similar, with the most frequently mutated genes being CDH1 (56% and 66%, respectively), PIK3CA (41% and 52%, respectively) and CBFB (12% and 19%, respectively). Among 19 LCIS and ILC synchronous pairs, 14 (74%) had at least one identical mutation in common, including identical PIK3CA and CDH1 mutations. Paired analysis of independent foci of LCIS from 3 breasts revealed at least one common mutation in each of the 3 pairs (CDH1, PIK3CA, CBFB and PKHD1L1). LCIS and ILC have a similar repertoire of somatic mutations, with PIK3CA and CDH1 being the most frequently mutated genes. The presence of identical mutations between LCIS-LCIS and LCIS-ILC pairs demonstrates that LCIS is a clonal neoplastic lesion, and provides additional evidence that at least some LCIS are non-obligate precursors of ILC. Copyright © 2015 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

  18. Effects of Various Kynurenine Metabolites on Respiratory Parameters of Rat Brain, Liver and Heart Mitochondria

    Directory of Open Access Journals (Sweden)

    Halina Baran*

    2016-01-01

    and heart mitochondria. Alterations of L-tryptophan metabolism might have an impact on the bioenergetic activities of brain, liver and/or heart mitochondria and might be involved in the development of clinical symptoms such as cardiomyopathy, hepatopathy and dementia.

  19. [Mitochondria inheritance in yeast saccharomyces cerevisiae].

    Science.gov (United States)

    Fizikova, A Iu

    2011-01-01

    The review is devoted to the main mechanisms of mitochondria inheritance in yeast Saccharonmyces cerevisiae. The genetic mechanisms of functionally active mitochondria inheritance in eukaryotic cells is one of the most relevant in modem researches. A great number of genetic diseases are associated with mitochondria dysfunction. Plasticity of eukaryotic cell metabolism according to the environmental changes is ensured by adequate mitochondria functioning by means of ATP synthesis coordination, reactive oxygen species accumulation, apoptosis regulation and is an important factor of cell adaptation to stress. Mitochondria participation in important for cell vitality processes masters the presence of accurate mechanisms of mitochondria functions regulation according to environment fluctuations. The mechanisms of mitochondria division and distribution are highly conserved. Baker yeast S. cerevisiae is an ideal model object for mitochondria researches due to energetic metabolism lability, ability to switch over respiration to fermentation, and petite-positive phenotype. Correction of metabolism according to the environmental changes is necessary for cell vitality. The influence of respiratory, carbon, amino acid and phosphate metabolism on mitochondria functions was shown. As far as the mechanisms that stabilize functions of mitochondria and mtDNA are highly conserve, we can project yeast regularities on higher eukaryotes systems. This makes it possible to approximate understanding the etiology and pathogenesis of a great number of human diseases.

  20. New Insights in the Amyloid-Beta Interaction with Mitochondria

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    Carlos Spuch

    2012-01-01

    Full Text Available Biochemical and morphological alterations of mitochondria may play an important role in the pathogenesis of Alzheimer’s disease (AD. Particularly, mitochondrial dysfunction is a hallmark of amyloid-beta-induced neuronal toxicity in Alzheimer’s disease. The recent emphasis on the intracellular biology of amyloid-beta and its precursor protein (APP has led researchers to consider the possibility that mitochondria-associated and mitochondrial amyloid-beta may directly cause neurotoxicity. Both proteins are known to localize to mitochondrial membranes, block the transport of nuclear-encoded mitochondrial proteins to mitochondria, interact with mitochondrial proteins, disrupt the electron transport chain, increase reactive oxygen species production, cause mitochondrial damage, and prevent neurons from functioning normally. In this paper, we will outline current knowledge of the intracellular localization of amyloid-beta. Moreover, we summarize evidence from AD postmortem brain as well as animal AD models showing that amyloid-beta triggers mitochondrial dysfunction through a number of pathways such as impairment of oxidative phosphorylation, elevation of reactive oxygen species production, alteration of mitochondrial dynamics, and interaction with mitochondrial proteins. Thus, this paper supports the Alzheimer cascade mitochondrial hypothesis such as the most important early events in this disease, and probably one of the future strategies on the therapy of this neurodegenerative disease.

  1. Mitochondria mediate septin cage assembly to promote autophagy of Shigella.

    Science.gov (United States)

    Sirianni, Andrea; Krokowski, Sina; Lobato-Márquez, Damián; Buranyi, Stephen; Pfanzelter, Julia; Galea, Dieter; Willis, Alexandra; Culley, Siân; Henriques, Ricardo; Larrouy-Maumus, Gerald; Hollinshead, Michael; Sancho-Shimizu, Vanessa; Way, Michael; Mostowy, Serge

    2016-07-01

    Septins, cytoskeletal proteins with well-characterised roles in cytokinesis, form cage-like structures around cytosolic Shigella flexneri and promote their targeting to autophagosomes. However, the processes underlying septin cage assembly, and whether they influence S. flexneri proliferation, remain to be established. Using single-cell analysis, we show that the septin cages inhibit S. flexneri proliferation. To study mechanisms of septin cage assembly, we used proteomics and found mitochondrial proteins associate with septins in S. flexneri-infected cells. Strikingly, mitochondria associated with S. flexneri promote septin assembly into cages that entrap bacteria for autophagy. We demonstrate that the cytosolic GTPase dynamin-related protein 1 (Drp1) interacts with septins to enhance mitochondrial fission. To avoid autophagy, actin-polymerising Shigella fragment mitochondria to escape from septin caging. Our results demonstrate a role for mitochondria in anti-Shigella autophagy and uncover a fundamental link between septin assembly and mitochondria. © 2016 The Authors. Published under the terms of the CC BY 4.0 license.

  2. Polyamine conjugation of curcumin analogues toward the discovery of mitochondria-directed neuroprotective agents.

    Science.gov (United States)

    Simoni, Elena; Bergamini, Christian; Fato, Romana; Tarozzi, Andrea; Bains, Sandip; Motterlini, Roberto; Cavalli, Andrea; Bolognesi, Maria Laura; Minarini, Anna; Hrelia, Patrizia; Lenaz, Giorgio; Rosini, Michela; Melchiorre, Carlo

    2010-10-14

    Mitochondria-directed antioxidants 2-5 were designed by conjugating curcumin congeners with different polyamine motifs as vehicle tools. The conjugates emerged as efficient antioxidants in mitochondria and fibroblasts and also exerted a protecting role through heme oxygenase-1 activation. Notably, the insertion of a polyamine function into the curcumin-like moiety allowed an efficient intracellular uptake and mitochondria targeting. It also resulted in a significant decrease in the cytotoxicity effects. 2-5 are therefore promising molecules for neuroprotectant lead discovery.

  3. DISC1 Modulates Neuronal Stress Responses by Gate-Keeping ER-Mitochondria Ca2+ Transfer through the MAM

    Directory of Open Access Journals (Sweden)

    Sung Jin Park

    2017-12-01

    Full Text Available Summary: A wide range of Ca2+-mediated functions are enabled by the dynamic properties of Ca2+, all of which are dependent on the endoplasmic reticulum (ER and mitochondria. Disrupted-in-schizophrenia 1 (DISC1 is a scaffold protein that is involved in the function of intracellular organelles and is linked to cognitive and emotional deficits. Here, we demonstrate that DISC1 localizes to the mitochondria-associated ER membrane (MAM. At the MAM, DISC1 interacts with IP3R1 and downregulates its ligand binding, modulating ER-mitochondria Ca2+ transfer through the MAM. The disrupted regulation of Ca2+ transfer caused by DISC1 dysfunction leads to abnormal Ca2+ accumulation in mitochondria following oxidative stress, which impairs mitochondrial functions. DISC1 dysfunction alters corticosterone-induced mitochondrial Ca2+ accumulation in an oxidative stress-dependent manner. Together, these findings link stress-associated neural stimuli with intracellular ER-mitochondria Ca2+ crosstalk via DISC1, providing mechanistic insight into how environmental risk factors can be interpreted by intracellular pathways under the control of genetic components in neurons. : Park et al. show that DISC1 regulates ER-mitochondria Ca2+ transfer through mitochondria-associated ER membrane (MAM. DISC1 dysfunction at MAM increases ER-mitochondria Ca2+ transfer during oxidative stress and excessive amounts of corticosterone, which impairs mitochondrial function. Keywords: DISC1, MAM, mitochondria, Ca2+, IP3R1, oxidative stress

  4. Mitochondria, Energetics, Epigenetics, and Cellular Responses to Stress

    Science.gov (United States)

    McAllister, Kimberly; Worth, Leroy; Haugen, Astrid C.; Meyer, Joel N.; Domann, Frederick E.; Van Houten, Bennett; Mostoslavsky, Raul; Bultman, Scott J.; Baccarelli, Andrea A.; Begley, Thomas J.; Sobol, Robert W.; Hirschey, Matthew D.; Ideker, Trey; Santos, Janine H.; Copeland, William C.; Tice, Raymond R.; Balshaw, David M.; Tyson, Frederick L.

    2014-01-01

    Background: Cells respond to environmental stressors through several key pathways, including response to reactive oxygen species (ROS), nutrient and ATP sensing, DNA damage response (DDR), and epigenetic alterations. Mitochondria play a central role in these pathways not only through energetics and ATP production but also through metabolites generated in the tricarboxylic acid cycle, as well as mitochondria–nuclear signaling related to mitochondria morphology, biogenesis, fission/fusion, mitophagy, apoptosis, and epigenetic regulation. Objectives: We investigated the concept of bidirectional interactions between mitochondria and cellular pathways in response to environmental stress with a focus on epigenetic regulation, and we examined DNA repair and DDR pathways as examples of biological processes that respond to exogenous insults through changes in homeostasis and altered mitochondrial function. Methods: The National Institute of Environmental Health Sciences sponsored the Workshop on Mitochondria, Energetics, Epigenetics, Environment, and DNA Damage Response on 25–26 March 2013. Here, we summarize key points and ideas emerging from this meeting. Discussion: A more comprehensive understanding of signaling mechanisms (cross-talk) between the mitochondria and nucleus is central to elucidating the integration of mitochondrial functions with other cellular response pathways in modulating the effects of environmental agents. Recent studies have highlighted the importance of mitochondrial functions in epigenetic regulation and DDR with environmental stress. Development and application of novel technologies, enhanced experimental models, and a systems-type research approach will help to discern how environmentally induced mitochondrial dysfunction affects key mechanistic pathways. Conclusions: Understanding mitochondria–cell signaling will provide insight into individual responses to environmental hazards, improving prediction of hazard and susceptibility to

  5. Mitochondria and Neurotransmission: Evacuating the Synapse

    OpenAIRE

    Hollenbeck, Peter J.

    2005-01-01

    An abundance of mitochondria has been the hallmark of synapses since their first ultrastructural description 50 years ago. Mitochondria have been shown to be essential for synaptic form and function in many systems, but until recently it has not been clear exactly what role(s) they play in neurotransmission. Now, evidence from the nervous system of Drosophila identifies the specific subcellular events that are most dependent upon nearby mitochondria.

  6. Mitochondria in biology and medicine

    DEFF Research Database (Denmark)

    Madsen, Claus Desler; Rasmussen, Lene Juel

    2012-01-01

    pathologies (Luft, 1994). Since 1959, the understanding of mitochondrial cytopathies has evolved immensely and mitochondrial cytopathies are now known to be the largest group of metabolic diseases and to be resulting in a wide variety of pathologies. "Mitochondria in Biology and Medicine" was the title...... of the first annual conference of Society of Mitochondrial Research and Medicine - India. The conference was organized by A. S. Sreedhar, Keshav Singh and Kumarasamy Thangaraj, and was held at The Centre for Cellular and Molecular Biology (CCMB) Hyderabad, India, during 9-10 December 2011. The conference...

  7. Dynamic survey of mitochondria by ubiquitin

    Science.gov (United States)

    Escobar-Henriques, Mafalda; Langer, Thomas

    2014-01-01

    Ubiquitin is a post-translational modifier with proteolytic and non-proteolytic roles in many biological processes. At mitochondria, it performs regulatory homeostatic functions and contributes to mitochondrial quality control. Ubiquitin is essential for mitochondrial fusion, regulates mitochondria-ER contacts, and participates in maternal mtDNA inheritance. Under stress, mitochondrial dysfunction induces ubiquitin-dependent responses that involve mitochondrial proteome remodeling and culminate in organelle removal by mitophagy. In addition, many ubiquitin-dependent mechanisms have been shown to regulate innate immune responses and xenophagy. Here, we review the emerging roles of ubiquitin at mitochondria. PMID:24569520

  8. Melatonin, mitochondria, and the skin.

    Science.gov (United States)

    Slominski, Andrzej T; Zmijewski, Michal A; Semak, Igor; Kim, Tae-Kang; Janjetovic, Zorica; Slominski, Radomir M; Zmijewski, Jaroslaw W

    2017-11-01

    The skin being a protective barrier between external and internal (body) environments has the sensory and adaptive capacity to maintain local and global body homeostasis in response to noxious factors. An important part of the skin response to stress is its ability for melatonin synthesis and subsequent metabolism through the indolic and kynuric pathways. Indeed, melatonin and its metabolites have emerged as indispensable for physiological skin functions and for effective protection of a cutaneous homeostasis from hostile environmental factors. Moreover, they attenuate the pathological processes including carcinogenesis and other hyperproliferative/inflammatory conditions. Interestingly, mitochondria appear to be a central hub of melatonin metabolism in the skin cells. Furthermore, substantial evidence has accumulated on the protective role of the melatonin against ultraviolet radiation and the attendant mitochondrial dysfunction. Melatonin and its metabolites appear to have a modulatory impact on mitochondrion redox and bioenergetic homeostasis, as well as the anti-apoptotic effects. Of note, some metabolites exhibit even greater impact than melatonin alone. Herein, we emphasize that melatonin-mitochondria axis would control integumental functions designed to protect local and perhaps global homeostasis. Given the phylogenetic origin and primordial actions of melatonin, we propose that the melatonin-related mitochondrial functions represent an evolutionary conserved mechanism involved in cellular adaptive response to skin injury and repair.

  9. Chromosome segregation regulation in human zygotes : Altered mitotic histone phosphorylation dynamics underlying centromeric targeting of the chromosomal passenger complex

    NARCIS (Netherlands)

    Van De Werken, C.; Avo Santos, M.; Laven, J. S E; Eleveld, C.; Fauser, B. C J M; Lens, S. M A; Baart, E. B.

    2015-01-01

    STUDY QUESTION Are the kinase feedback loops that regulate activation and centromeric targeting of the chromosomal passenger complex (CPC), functional during mitosis in human embryos? SUMMARY ANSWER Investigation of the regulatory kinase pathways involved in centromeric CPC targeting revealed normal

  10. Maximizing in vivo target clearance by design of pH-dependent target binding antibodies with altered affinity to FcRn.

    Science.gov (United States)

    Yang, Danlin; Giragossian, Craig; Castellano, Steven; Lasaro, Marcio; Xiao, Haiguang; Saraf, Himanshu; Hess Kenny, Cynthia; Rybina, Irina; Huang, Zhong-Fu; Ahlberg, Jennifer; Bigwarfe, Tammy; Myzithras, Maria; Waltz, Erica; Roberts, Simon; Kroe-Barrett, Rachel; Singh, Sanjaya

    2017-10-01

    Antibodies with pH-dependent binding to both target antigens and neonatal Fc receptor (FcRn) provide an alternative tool to conventional neutralizing antibodies, particularly for therapies where reduction in antigen level is challenging due to high target burden. However, the requirements for optimal binding kinetic framework and extent of pH dependence for these antibodies to maximize target clearance from circulation are not well understood. We have identified a series of naturally-occurring high affinity antibodies with pH-dependent target binding properties. By in vivo studies in cynomolgus monkeys, we show that pH-dependent binding to the target alone is not sufficient for effective target removal from circulation, but requires Fc mutations that increase antibody binding to FcRn. Affinity-enhanced pH-dependent FcRn binding that is double-digit nM at pH 7.4 and single-digit nM at pH 6 achieved maximal target reduction when combined with similar target binding affinities in reverse pH directions. Sustained target clearance below the baseline level was achieved 3 weeks after single-dose administration at 1.5 mg/kg. Using the experimentally derived mechanistic model, we demonstrate the essential kinetic interplay between target turnover and antibody pH-dependent binding during the FcRn recycling, and identify the key components for achieving maximal target clearance. These results bridge the demand for improved patient dosing convenience with the "know-how" of therapeutic modality by design.

  11. Your mitochondria are what you eat

    DEFF Research Database (Denmark)

    Jørgensen, Wenche; Rud, Kasper Abildgaard; Mortensen, Ole Hartvig

    2017-01-01

    of the mitochondria. Here, we report that rat muscle mitochondria does show the normal Randle‐type fat‐carbohydrate interaction seen in vivo. The mechanism behind this metabolic flexibility at the level of the isolated mitochondria is a regulation of the flux‐ratio: pyruvate dehydrogenase (PDH)/β‐oxidation to suit...... the actual substrate availability, with the PDH flux as the major point of regulation. We further report that this regulatory mechanism of carbohydrate‐fat metabolic interaction surprisingly is lost in mitochondria obtained from animals exposed for 12 weeks to a HF‐ or a HS diet as compared to rats given...... a normal chow diet. The mechanism seems to be a loss of the PDH flux decrease seen in controls, when fatty acid is supplied as substrate in addition to pyruvate, and vice versa for the supply of pyruvate as substrate to mitochondria oxidizing fatty acid. Finally, we report that the calculated TCA flux...

  12. Insulin alters the target size of the peripheral cyclic AMP phosphodiesterase but not the integral cyclic GMP-stimulated cyclic AMP phosphodiesterase in liver plasma membranes

    International Nuclear Information System (INIS)

    Wallace, A.V.; Martin, B.R.; Houslay, M.D.

    1990-01-01

    Radiation inactivation of the two high affinity cyclic AMP phosphodiesterases (PDE) found in liver plasma membranes afforded an estimation of their molecular target sizes in situ. The activity of the peripheral plasma membrane PDE decayed as a single exponential with a target size corresponding to a monomer of circa 54 kDa. The integral, cyclic GMP-stimulated PDE decayed as a dimer of circa 125 kDa. Preincubation of plasma membranes with insulin (10nM), prior to irradiation, caused the target size of only the peripheral plasma membrane PDE to increase. We suggest that insulin addition causes the peripheral plasma membrane PDE to alter its coupling to an integral plasma membrane protein with a target size of circa 90 kDa

  13. Mitochondria, Energy and Cancer: The Relationship with Ascorbic Acid

    Science.gov (United States)

    González, Michael J.; Rosario-Pérez, Glorivee; Guzmán, Angélica M.; Miranda-Massari, Jorge R.; Duconge, Jorge; Lavergne, Julio; Fernandez, Nadia; Ortiz, Norma; Quintero, Ana; Mikirova, Nina; Riordan, Neil H.; Ricart, Carlos M.

    2012-01-01

    Ascorbic Acid (AA) has been used in the prevention and treatment of cancer with reported effectiveness. Mitochondria may be one of the principal targets of ascorbate's cellular activity and it may play an important role in the development and progression of cancer. Mitochondria, besides generating adenosine triphosphate (ATP), has a role in apoptosis regulation and in the production of regulatory oxidative species that may be relevant in gene expression. At higher concentrations AA may increase ATP production by increasing mitochondrial electron flux, also may induce apoptotic cell death in tumor cell lines, probably via its pro-oxidant action In contrast, at lower concentrations AA displays antioxidant properties that may prevent the activation of oxidant-induced apoptosis. These concentration dependent activities of ascorbate may explain in part the seemingly contradictory results that have been reported previously. PMID:23565030

  14. Modeling population dynamics of mitochondria in mammalian cells

    Science.gov (United States)

    Kornick, Kellianne; Das, Moumita

    Mitochondria are organelles located inside eukaryotic cells and are essential for several key cellular processes such as energy (ATP) production, cell signaling, differentiation, and apoptosis. All organisms are believed to have low levels of variation in mitochondrial DNA (mtDNA), and alterations in mtDNA are connected to a range of human health conditions, including epilepsy, heart failure, Parkinsons disease, diabetes, and multiple sclerosis. Therefore, understanding how changes in mtDNA accumulate over time and are correlated to changes in mitochondrial function and cell properties can have a profound impact on our understanding of cell physiology and the origins of some diseases. Motivated by this, we develop and study a mathematical model to determine which cellular parameters have the largest impact on mtDNA population dynamics. The model consists of coupled ODEs to describe subpopulations of healthy and dysfunctional mitochondria subject to mitochondrial fission, fusion, autophagy, and mutation. We study the time evolution and stability of each sub-population under specific selection biases and pressures by tuning specific terms in our model. Our results may provide insights into how sub-populations of mitochondria survive and evolve under different selection pressures. This work was supported by a Grant from the Moore Foundation.

  15. Ectopic overexpression of LAPTM5 results in lysosomal targeting and induces Mcl-1 down-regulation, Bak activation, and mitochondria-dependent apoptosis in human HeLa cells.

    Directory of Open Access Journals (Sweden)

    Do Youn Jun

    demonstrate that ectopic overexpression of LAPTM5 in HeLa cells induced apoptosis via cleavage of Mcl-1 and Bid by a LAPTM5-associated lysosomal pathway, and subsequent activation of the mitochondria-dependent caspase cascade.

  16. Ectopic overexpression of LAPTM5 results in lysosomal targeting and induces Mcl-1 down-regulation, Bak activation, and mitochondria-dependent apoptosis in human HeLa cells

    Science.gov (United States)

    Jun, Do Youn; Kim, Hyejin; Jang, Won Young; Lee, Ji Young; Fukui, Kiyoshi; Kim, Young Ho

    2017-01-01

    ectopic overexpression of LAPTM5 in HeLa cells induced apoptosis via cleavage of Mcl-1 and Bid by a LAPTM5-associated lysosomal pathway, and subsequent activation of the mitochondria-dependent caspase cascade. PMID:28464033

  17. Mitochondria-associated endoplasmic reticulum membranes allow adaptation of mitochondrial metabolism to glucose availability in the liver.

    Science.gov (United States)

    Theurey, Pierre; Tubbs, Emily; Vial, Guillaume; Jacquemetton, Julien; Bendridi, Nadia; Chauvin, Marie-Agnès; Alam, Muhammad Rizwan; Le Romancer, Muriel; Vidal, Hubert; Rieusset, Jennifer

    2016-04-01

    Mitochondria-associated endoplasmic reticulum membranes (MAM) play a key role in mitochondrial dynamics and function and in hepatic insulin action. Whereas mitochondria are important regulators of energy metabolism, the nutritional regulation of MAM in the liver and its role in the adaptation of mitochondria physiology to nutrient availability are unknown. In this study, we found that the fasted to postprandial transition reduced the number of endoplasmic reticulum-mitochondria contact points in mouse liver. Screening of potential hormonal/metabolic signals revealed glucose as the main nutritional regulator of hepatic MAM integrity both in vitro and in vivo Glucose reduced organelle interactions through the pentose phosphate-protein phosphatase 2A (PP-PP2A) pathway, induced mitochondria fission, and impaired respiration. Blocking MAM reduction counteracted glucose-induced mitochondrial alterations. Furthermore, disruption of MAM integrity mimicked effects of glucose on mitochondria dynamics and function. This glucose-sensing system is deficient in the liver of insulin-resistant ob/ob and cyclophilin D-KO mice, both characterized by chronic disruption of MAM integrity, mitochondrial fission, and altered mitochondrial respiration. These data indicate that MAM contribute to the hepatic glucose-sensing system, allowing regulation of mitochondria dynamics and function during nutritional transition. Chronic disruption of MAM may participate in hepatic mitochondrial dysfunction associated with insulin resistance. © The Author (2016). Published by Oxford University Press on behalf of Journal of Molecular Cell Biology, IBCB, SIBS, CAS. All rights reserved.

  18. Original geochemical types and epigenetic alteration of rocks in prospecting target stratum for uranium deposit in the southeast of Songliao basin

    International Nuclear Information System (INIS)

    Lin Jinrong; Tian Hua; Dong Wenming; Xia Yuliang; Qi Daneng; Yao Shancong; Zheng Jiwei

    2009-01-01

    By comprehensive analysis on informations of regional geology and evaluating drillhole works of uranium resources in the southeast of Songliao basin, lithofacies-palaeogeography features, lithologies and sandbody characteristics of target layes in Quantou formation, Yaojia formation and Sifangtai formation have been basically found out. By research on geochemical environment of rocks in target layez, types of original geochemistry and epigenetic alteration have been identified and classified. The types of original geochemistry have been divided into types of original oxidation and original reduction, and the types of epigenetic alteration have been divided into types of reduction by oil-gas and coalbed gas and epigenetic oxidation. By comparative study on mineral and chemical characteristics of original geochemistry and epigenetic oxidation, identification marks for oil-gas and coalbed gas reduced epigenetic oxidation have been proposed. It is proposed that uranium was strongly pre-concentrated in original sandstone that bearing carboniferous matter, and reduction by oil-gas and coalbed gas made uranium superimpose and concentrate in alterated rocks. (authors)

  19. Mitochondria-meditated pathways of organ failure upon inflammation

    Directory of Open Access Journals (Sweden)

    Andrey V. Kozlov

    2017-10-01

    Full Text Available Liver failure induced by systemic inflammatory response (SIRS is often associated with mitochondrial dysfunction but the mechanism linking SIRS and mitochondria-mediated liver failure is still a matter of discussion. Current hypotheses suggest that causative events could be a drop in ATP synthesis, opening of mitochondrial permeability transition pore, specific changes in mitochondrial morphology, impaired Ca2+ uptake, generation of mitochondrial reactive oxygen species (mtROS, turnover of mitochondria and imbalance in electron supply to the respiratory chain. The aim of this review is to critically analyze existing hypotheses, in order to highlight the most promising research lines helping to prevent liver failure induced by SIRS. Evaluation of the literature shows that there is no consistent support that impaired Ca++ metabolism, electron transport chain function and ultrastructure of mitochondria substantially contribute to liver failure. Moreover, our analysis suggests that the drop in ATP levels has protective rather than a deleterious character. Recent data suggest that the most critical mitochondrial event occurring upon SIRS is the release of mtROS in cytoplasm, which can activate two specific intracellular signaling cascades. The first is the mtROS-mediated activation of NADPH-oxidase in liver macrophages and endothelial cells; the second is the acceleration of the expression of inflammatory genes in hepatocytes. The signaling action of mtROS is strictly controlled in mitochondria at three points, (i at the site of ROS generation at complex I, (ii the site of mtROS release in cytoplasm via permeability transition pore, and (iii interaction with specific kinases in cytoplasm. The systems controlling mtROS-signaling include pro- and anti-inflammatory mediators, nitric oxide, Ca2+ and NADPH-oxidase. Analysis of the literature suggests that further research should be focused on the impact of mtROS on organ failure induced by inflammation

  20. Peroxisome-mitochondria interplay and disease.

    Science.gov (United States)

    Schrader, Michael; Costello, Joseph; Godinho, Luis F; Islinger, Markus

    2015-07-01

    Peroxisomes and mitochondria are ubiquitous, highly dynamic organelles with an oxidative type of metabolism in eukaryotic cells. Over the years, substantial evidence has been provided that peroxisomes and mitochondria exhibit a close functional interplay which impacts on human health and development. The so-called "peroxisome-mitochondria connection" includes metabolic cooperation in the degradation of fatty acids, a redox-sensitive relationship, an overlap in key components of the membrane fission machineries and cooperation in anti-viral signalling and defence. Furthermore, combined peroxisome-mitochondria disorders with defects in organelle division have been revealed. In this review, we present the latest progress in the emerging field of peroxisomal and mitochondrial interplay in mammals with a particular emphasis on cooperative fatty acid β-oxidation, redox interplay, organelle dynamics, cooperation in anti-viral signalling and the resulting implications for disease.

  1. Mechanisms of communication between mitochondria and lysosomes.

    Science.gov (United States)

    Raimundo, Nuno; Fernández-Mosquera, Lorena; Yambire, King Faisal; Diogo, Cátia V

    2016-10-01

    Mitochondria and lysosomes have long been studied in the context of their classic functions: energy factory and recycle bin, respectively. In the last twenty years, it became evident that these organelles are much more than simple industrial units, and are indeed in charge of many of cellular processes. Both mitochondria and lysosomes are now recognized as far-reaching signaling platforms, regulating many key aspects of cell and tissue physiology. It has furthermore become clear that mitochondria and lysosomes impact each other. The mechanisms underlying the cross-talk between these organelles are only now starting to be addressed. In this review, we briefly summarize how mitochondria, lysosomes and the lysosome-related process of autophagy affect each other in physiology and pathology. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Isolation of Mitochondria from Potato Tubers

    DEFF Research Database (Denmark)

    Havelund, Jesper F.; Salvato, Fernanda; Chen, Mingjie

    2014-01-01

    One way to study the function of plant mitochondria is to extract them from plant tissues in an uncontaminated, intact and functional form. The reductionist assumption is that the components present in such a preparation and the in vitro measurable functions or activities reliably reflect...... the in vivo properties of the organelle inside the plant cell. Here, we describe a method to isolate mitochondria from a relatively homogeneous plant tissue, the dormant potato tuber. The homogenization is done using a juice extractor, which is a relatively gentle homogenization procedure where...... the mitochondria are only exposed to strong shearing forces once. After removal of starch and large tissue pieces by filtration, differential centrifugation is used to remove residual starch as well as larger organelles. The crude mitochondria are then first purified by using a step Percoll gradient...

  3. A deficiency of apoptosis inducing factor (AIF in Harlequin mouse heart mitochondria paradoxically reduces ROS generation during ischemia-reperfusion

    Directory of Open Access Journals (Sweden)

    Qun eChen

    2014-07-01

    Full Text Available Background and Aims: AIF (apoptosis inducing factor is a flavin and NADH containing protein located within mitochondria required for optimal function of the respiratory chain. AIF may function as an antioxidant within mitochondria, yet when released from mitochondria it activates caspase-independent cell death. The Harlequin (Hq mouse has a markedly reduced content of AIF, providing an experimental model to query if the main role of AIF in the exacerbation of cell death is enhanced mitochondrial generation of reactive oxygen species (ROS or the activation of cell death programs. We asked if the ROS generation is altered in Hq heart mitochondria at baseline or following ischemia-reperfusion (IR.Methods: Buffer perfused mouse hearts underwent 30 min ischemia and 30 min reperfusion. Mitochondrial function including oxidative phosphorylation and H2O2 generation was measured. Immunoblotting was used to determine the contents of AIF and PAR [poly(ADP-ribose] in cell fractions.Results: There were no differences in the release of H2O2 between wild type (WT and Hq heart mitochondria at baseline. IR increased H2O2 generation from WT but not from Hq mitochondria compared to corresponding time controls. The complex I activity was decreased in WT but not in Hq mice following IR. The relocation of AIF from mitochondria to nucleus was increased in WT but not in Hq mice. IR activated PARP-1 only in WT mice. Cell injury was decreased in Hq mouse heart following in vitro IR.Conclusion: A deficiency of AIF within mitochondria does not increase ROS production during IR, indicating that AIF functions less as an antioxidant within mitochondria. The decreased cardiac injury in Hq mouse heart accompanied by less AIF translocation to the nucleus suggests that AIF relocation, rather than the AIF content within mitochondria, contributes to cardiac injury during IR.

  4. Pluripotent Stem Cell Metabolism and Mitochondria: Beyond ATP

    Directory of Open Access Journals (Sweden)

    Jarmon G. Lees

    2017-01-01

    Full Text Available Metabolism is central to embryonic stem cell (ESC pluripotency and differentiation, with distinct profiles apparent under different nutrient milieu, and conditions that maintain alternate cell states. The significance of altered nutrient availability, particularly oxygen, and metabolic pathway activity has been highlighted by extensive studies of their impact on preimplantation embryo development, physiology, and viability. ESC similarly modulate their metabolism in response to altered metabolite levels, with changes in nutrient availability shown to have a lasting impact on derived cell identity through the regulation of the epigenetic landscape. Further, the preferential use of glucose and anaplerotic glutamine metabolism serves to not only support cell growth and proliferation but also minimise reactive oxygen species production. However, the perinuclear localisation of spherical, electron-poor mitochondria in ESC is proposed to sustain ESC nuclear-mitochondrial crosstalk and a mitochondrial-H2O2 presence, to facilitate signalling to support self-renewal through the stabilisation of HIFα, a process that may be favoured under physiological oxygen. The environment in which a cell is grown is therefore a critical regulator and determinant of cell fate, with metabolism, and particularly mitochondria, acting as an interface between the environment and the epigenome.

  5. Photothermal imaging of skeletal muscle mitochondria.

    Science.gov (United States)

    Tomimatsu, Toru; Miyazaki, Jun; Kano, Yutaka; Kobayashi, Takayoshi

    2017-06-01

    The morphology and topology of mitochondria provide useful information about the physiological function of skeletal muscle. Previous studies of skeletal muscle mitochondria are based on observation with transmission, scanning electron microscopy or fluorescence microscopy. In contrast, photothermal (PT) microscopy has advantages over the above commonly used microscopic techniques because of no requirement for complex sample preparation by fixation or fluorescent-dye staining. Here, we employed the PT technique using a simple diode laser to visualize skeletal muscle mitochondria in unstained and stained tissues. The fine mitochondrial network structures in muscle fibers could be imaged with the PT imaging system, even in unstained tissues. PT imaging of tissues stained with toluidine blue revealed the structures of subsarcolemmal (SS) and intermyofibrillar (IMF) mitochondria and the swelling behavior of mitochondria in damaged muscle fibers with sufficient image quality. PT image analyses based on fast Fourier transform (FFT) and Grey-level co-occurrence matrix (GLCM) were performed to derive the characteristic size of mitochondria and to discriminate the image patterns of normal and damaged fibers.

  6. Target of rapamycin signalling mediates the lifespan-extending effects of dietary restriction by essential amino acid alteration

    NARCIS (Netherlands)

    Emran, S.; Yang, M.Y.; He, X.L.; Zandveld, J.; Piper, M.D.W.

    2014-01-01

    Dietary restriction (DR), defined as a moderate reduction in food intake short of malnutrition, has been shown to extend healthy lifespan in a diverse range of organisms, from yeast to primates. Reduced signalling through the insulin/IGF-like (IIS) and Target of Rapamycin (TOR) signalling pathways

  7. Functional Mitochondria in Health and Disease.

    Science.gov (United States)

    Herst, Patries M; Rowe, Matthew R; Carson, Georgia M; Berridge, Michael V

    2017-01-01

    The ability to rapidly adapt cellular bioenergetic capabilities to meet rapidly changing environmental conditions is mandatory for normal cellular function and for cancer progression. Any loss of this adaptive response has the potential to compromise cellular function and render the cell more susceptible to external stressors such as oxidative stress, radiation, chemotherapeutic drugs, and hypoxia. Mitochondria play a vital role in bioenergetic and biosynthetic pathways and can rapidly adjust to meet the metabolic needs of the cell. Increased demand is met by mitochondrial biogenesis and fusion of individual mitochondria into dynamic networks, whereas a decrease in demand results in the removal of superfluous mitochondria through fission and mitophagy. Effective communication between nucleus and mitochondria (mito-nuclear cross talk), involving the generation of different mitochondrial stress signals as well as the nuclear stress response pathways to deal with these stressors, maintains bioenergetic homeostasis under most conditions. However, when mitochondrial DNA (mtDNA) mutations accumulate and mito-nuclear cross talk falters, mitochondria fail to deliver critical functional outputs. Mutations in mtDNA have been implicated in neuromuscular and neurodegenerative mitochondriopathies and complex diseases such as diabetes, cardiovascular diseases, gastrointestinal disorders, skin disorders, aging, and cancer. In some cases, drastic measures such as acquisition of new mitochondria from donor cells occurs to ensure cell survival. This review starts with a brief discussion of the evolutionary origin of mitochondria and summarizes how mutations in mtDNA lead to mitochondriopathies and other degenerative diseases. Mito-nuclear cross talk, including various stress signals generated by mitochondria and corresponding stress response pathways activated by the nucleus are summarized. We also introduce and discuss a small family of recently discovered hormone-like mitopeptides

  8. Functional Mitochondria in Health and Disease

    Directory of Open Access Journals (Sweden)

    Patries M. Herst

    2017-11-01

    Full Text Available The ability to rapidly adapt cellular bioenergetic capabilities to meet rapidly changing environmental conditions is mandatory for normal cellular function and for cancer progression. Any loss of this adaptive response has the potential to compromise cellular function and render the cell more susceptible to external stressors such as oxidative stress, radiation, chemotherapeutic drugs, and hypoxia. Mitochondria play a vital role in bioenergetic and biosynthetic pathways and can rapidly adjust to meet the metabolic needs of the cell. Increased demand is met by mitochondrial biogenesis and fusion of individual mitochondria into dynamic networks, whereas a decrease in demand results in the removal of superfluous mitochondria through fission and mitophagy. Effective communication between nucleus and mitochondria (mito-nuclear cross talk, involving the generation of different mitochondrial stress signals as well as the nuclear stress response pathways to deal with these stressors, maintains bioenergetic homeostasis under most conditions. However, when mitochondrial DNA (mtDNA mutations accumulate and mito-nuclear cross talk falters, mitochondria fail to deliver critical functional outputs. Mutations in mtDNA have been implicated in neuromuscular and neurodegenerative mitochondriopathies and complex diseases such as diabetes, cardiovascular diseases, gastrointestinal disorders, skin disorders, aging, and cancer. In some cases, drastic measures such as acquisition of new mitochondria from donor cells occurs to ensure cell survival. This review starts with a brief discussion of the evolutionary origin of mitochondria and summarizes how mutations in mtDNA lead to mitochondriopathies and other degenerative diseases. Mito-nuclear cross talk, including various stress signals generated by mitochondria and corresponding stress response pathways activated by the nucleus are summarized. We also introduce and discuss a small family of recently discovered hormone

  9. Mitochondria and α-Synuclein: Friends or Foes in the Pathogenesis of Parkinson's Disease?

    Science.gov (United States)

    Faustini, Gaia; Bono, Federica; Valerio, Alessandra; Pizzi, Marina; Spano, PierFranco; Bellucci, Arianna

    2017-12-08

    Parkinson's disease (PD) is a movement disorder characterized by dopaminergic nigrostriatal neuron degeneration and the formation of Lewy bodies (LB), pathological inclusions containing fibrils that are mainly composed of α-synuclein. Dopaminergic neurons, for their intrinsic characteristics, have a high energy demand that relies on the efficiency of the mitochondria respiratory chain. Dysregulations of mitochondria, deriving from alterations of complex I protein or oxidative DNA damage, change the trafficking, size and morphology of these organelles. Of note, these mitochondrial bioenergetics defects have been related to PD. A series of experimental evidence supports that α-synuclein physiological action is relevant for mitochondrial homeostasis, while its pathological aggregation can negatively impinge on mitochondrial function. It thus appears that imbalances in the equilibrium between the reciprocal modulatory action of mitochondria and α-synuclein can contribute to PD onset by inducing neuronal impairment. This review will try to highlight the role of physiological and pathological α-synuclein in the modulation of mitochondrial functions.

  10. Mitochondria and the non-genetic origins of cell-to-cell variability: More is different.

    Science.gov (United States)

    Guantes, Raúl; Díaz-Colunga, Juan; Iborra, Francisco J

    2016-01-01

    Gene expression activity is heterogeneous in a population of isogenic cells. Identifying the molecular basis of this variability will improve our understanding of phenomena like tumor resistance to drugs, virus infection, or cell fate choice. The complexity of the molecular steps and machines involved in transcription and translation could introduce sources of randomness at many levels, but a common constraint to most of these processes is its energy dependence. In eukaryotic cells, most of this energy is provided by mitochondria. A clonal population of cells may show a large variability in the number and functionality of mitochondria. Here, we discuss how differences in the mitochondrial content of each cell contribute to heterogeneity in gene products. Changes in the amount of mitochondria can also entail drastic alterations of a cell's gene expression program, which ultimately leads to phenotypic diversity. Also watch the Video Abstract. © 2015 WILEY Periodicals, Inc.

  11. MiR-34a-3p alters proliferation and apoptosis of meningioma cells in vitro and is directly targeting SMAD4, FRAT1 and BCL2

    Science.gov (United States)

    Werner, Tamara V.; Hart, Martin; Nickels, Ruth; Kim, Yoo-Jin; Menger, Michael D.; Bohle, Rainer M.; Keller, Andreas; Ludwig, Nicole; Meese, Eckart

    2017-01-01

    Micro (mi)RNAs are short, noncoding RNAs and deregulation of miRNAs and their targets are implicated in tumor generation and progression in many cancers. Meningiomas are mostly benign, slow growing tumors of the central nervous system with a small percentage showing a malignant phenotype. Following in silico prediction of potential targets of miR-34a-3p, SMAD4, FRAT1, and BCL2 have been confirmed as targets by dual luciferase assays with co-expression of miR-34a-3p and reporter gene constructs containing the respective 3'UTRs. Disruption of the miR-34a-3p binding sites in the 3'UTRs resulted in loss of responsiveness to miR-34a-3p overexpression. In meningioma cells, overexpression of miR-34a-3p resulted in decreased protein levels of SMAD4, FRAT1 and BCL2, while inhibition of miR-34a-3p led to increased levels of these proteins as confirmed by Western blotting. Furthermore, deregulation of miR-34a-3p altered cell proliferation and apoptosis of meningioma cells in vitro. We show that SMAD4, FRAT1 and BCL2 are direct targets of miR-34a-3p and that deregulation of miR-34a-3p alters proliferation and apoptosis of meningioma cells in vitro. As part of their respective signaling pathways, which are known to play a role in meningioma genesis and progression, deregulation of SMAD4, FRAT1 and BCL2 might contribute to the aberrant activation of these signaling pathways leading to increased proliferation and inhibition of apoptosis in meningiomas. PMID:28340489

  12. JC virus induces altered patterns of cellular gene expression: Interferon-inducible genes as major transcriptional targets

    International Nuclear Information System (INIS)

    Verma, Saguna; Ziegler, Katja; Ananthula, Praveen; Co, Juliene K.G.; Frisque, Richard J.; Yanagihara, Richard; Nerurkar, Vivek R.

    2006-01-01

    Human polyomavirus JC (JCV) infects 80% of the population worldwide. Primary infection, typically occurring during childhood, is asymptomatic in immunocompetent individuals and results in lifelong latency and persistent infection. However, among the severely immunocompromised, JCV may cause a fatal demyelinating disease, progressive multifocal leukoencephalopathy (PML). Virus-host interactions influencing persistence and pathogenicity are not well understood, although significant regulation of JCV activity is thought to occur at the level of transcription. Regulation of the JCV early and late promoters during the lytic cycle is a complex event that requires participation of both viral and cellular factors. We have used cDNA microarray technology to analyze global alterations in gene expression in JCV-permissive primary human fetal glial cells (PHFG). Expression of more than 400 cellular genes was altered, including many that influence cell proliferation, cell communication and interferon (IFN)-mediated host defense responses. Genes in the latter category included signal transducer and activator of transcription 1 (STAT1), interferon stimulating gene 56 (ISG56), myxovirus resistance 1 (MxA), 2'5'-oligoadenylate synthetase (OAS), and cig5. The expression of these genes was further confirmed in JCV-infected PHFG cells and the human glioblastoma cell line U87MG to ensure the specificity of JCV in inducing this strong antiviral response. Results obtained by real-time RT-PCR and Western blot analyses supported the microarray data and provide temporal information related to virus-induced changes in the IFN response pathway. Our data indicate that the induction of an antiviral response may be one of the cellular factors regulating/controlling JCV replication in immunocompetent hosts and therefore constraining the development of PML

  13. Mitochondria and ageing: role in heart, skeletal muscle and adipose tissue

    Science.gov (United States)

    Boengler, Kerstin; Kosiol, Maik; Mayr, Manuel; Schulz, Rainer

    2017-01-01

    Abstract Age is the most important risk factor for most diseases. Mitochondria play a central role in bioenergetics and metabolism. In addition, several lines of evidence indicate the impact of mitochondria in lifespan determination and ageing. The best‐known hypothesis to explain ageing is the free radical theory, which proposes that cells, organs, and organisms age because they accumulate reactive oxygen species (ROS) damage over time. Mitochondria play a central role as the principle source of intracellular ROS, which are mainly formed at the level of complex I and III of the respiratory chain. Dysfunctional mitochondria generating less ATP have been observed in various aged organs. Mitochondrial dysfunction comprises different features including reduced mitochondrial content, altered mitochondrial morphology, reduced activity of the complexes of the electron transport chain, opening of the mitochondrial permeability transition pore, and increased ROS formation. Furthermore, abnormalities in mitochondrial quality control or defects in mitochondrial dynamics have also been linked to senescence. Among the tissues affected by mitochondrial dysfunction are those with a high‐energy demand and thus high mitochondrial content. Therefore, the present review focuses on the impact of mitochondria in the ageing process of heart and skeletal muscle. In this article, we review different aspects of mitochondrial dysfunction and discuss potential therapeutic strategies to improve mitochondrial function. Finally, novel aspects of adipose tissue biology and their involvement in the ageing process are discussed. PMID:28432755

  14. Bcl-2 prevents loss of mitochondria in CCCP-induced apoptosis

    International Nuclear Information System (INIS)

    Graaf, Aniek O. de; Heuvel, Lambert P. van den; Dijkman, Henry B.P.M.; Abreu, Ronney A. de; Birkenkamp, Kim U.; Witte, Theo de; Reijden, Bert A. van der; Smeitink, Jan A.M.; Jansen, Joop H.

    2004-01-01

    Bcl-2 family proteins regulate apoptosis at the level of mitochondria. To examine the mechanism of Bcl-2 function, we investigated the effects of the protonophore carbonyl cyanide m-chlorophenyl hydrazone (CCCP) on two hematopoietic cell lines and Bcl-2 overexpressing transfectants. CCCP directly interferes with mitochondrial function and induces apoptosis. We show that Bcl-2 inhibits apoptosis and that the antiapoptotic effect of Bcl-2 takes place upstream of caspase activation and nuclear changes associated with apoptosis, since these were markedly inhibited in cells overexpressing Bcl-2. Bcl-2 does not prevent the decrease in mitochondrial membrane potential nor the alterations in cellular ATP content induced by CCCP in FL5.12 and Jurkat cells. A higher number of mitochondria was observed in untreated Bcl-2 transfected cells compared to parental cells, as shown by electron microscopy. Exposure to CCCP induced a dramatic decrease in the number of mitochondria and severely disrupted mitochondrial ultrastructure, with apparent swelling and loss of cristae in parental cells. Bcl-2 clearly diminished the disruption of mitochondrial structure and preserved a higher number of mitochondria. These data suggest that CCCP induces apoptosis by structural disruption of mitochondria and that Bcl-2 prevents apoptosis and mitochondrial degeneration by preserving mitochondrial integrity

  15. Bcl-2 prevents loss of mitochondria in CCCP-induced apoptosis.

    Science.gov (United States)

    de Graaf, Aniek O; van den Heuvel, Lambert P; Dijkman, Henry B P M; de Abreu, Ronney A; Birkenkamp, Kim U; de Witte, Theo; van der Reijden, Bert A; Smeitink, Jan A M; Jansen, Joop H

    2004-10-01

    Bcl-2 family proteins regulate apoptosis at the level of mitochondria. To examine the mechanism of Bcl-2 function, we investigated the effects of the protonophore carbonyl cyanide m-chlorophenyl hydrazone (CCCP) on two hematopoietic cell lines and Bcl-2 overexpressing transfectants. CCCP directly interferes with mitochondrial function and induces apoptosis. We show that Bcl-2 inhibits apoptosis and that the antiapoptotic effect of Bcl-2 takes place upstream of caspase activation and nuclear changes associated with apoptosis, since these were markedly inhibited in cells overexpressing Bcl-2. Bcl-2 does not prevent the decrease in mitochondrial membrane potential nor the alterations in cellular ATP content induced by CCCP in FL5.12 and Jurkat cells. A higher number of mitochondria was observed in untreated Bcl-2 transfected cells compared to parental cells, as shown by electron microscopy. Exposure to CCCP induced a dramatic decrease in the number of mitochondria and severely disrupted mitochondrial ultrastructure, with apparent swelling and loss of cristae in parental cells. Bcl-2 clearly diminished the disruption of mitochondrial structure and preserved a higher number of mitochondria. These data suggest that CCCP induces apoptosis by structural disruption of mitochondria and that Bcl-2 prevents apoptosis and mitochondrial degeneration by preserving mitochondrial integrity.

  16. Mitochondria in Cancer: Why Mitochondria Are a Good Target for Cancer Therapy

    Czech Academy of Sciences Publication Activity Database

    Dong, L.F.; Neužil, Jiří

    2014-01-01

    Roč. 2014, č. 127 (2014), s. 211-227 ISSN 1877-1173 Institutional support: RVO:86652036 Keywords : ALPHA -TOCOPHERYL SUCCINATE * RESPIRATORY COMPLEX-II * DNA MUTATIONS Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.488, year: 2014

  17. Evaluation of respiration of mitochondria in cancer cells exposed to mitochondria-targeted agents.

    Czech Academy of Sciences Publication Activity Database

    Klučková, Katarína; Dong, L. F.; Bajziková, Martina; Rohlena, Jakub; Neužil, Jiří

    2015-01-01

    Roč. 1265, 07 Oct 2015 (2015), s. 181-194 ISSN 1940-6029 R&D Projects: GA MŠk(CZ) ED1.1.00/02.0109 Institutional support: RVO:86652036 Keywords : Animals * Antineoplastic Agents * drug effects * *pharmacology Subject RIV: EB - Genetics ; Molecular Biology

  18. Chromosome segregation regulation in human zygotes: altered mitotic histone phosphorylation dynamics underlying centromeric targeting of the chromosomal passenger complex.

    Science.gov (United States)

    van de Werken, C; Avo Santos, M; Laven, J S E; Eleveld, C; Fauser, B C J M; Lens, S M A; Baart, E B

    2015-10-01

    Are the kinase feedback loops that regulate activation and centromeric targeting of the chromosomal passenger complex (CPC), functional during mitosis in human embryos? Investigation of the regulatory kinase pathways involved in centromeric CPC targeting revealed normal phosphorylation dynamics of histone H2A at T120 (H2ApT120) by Bub1 kinase and subsequent recruitment of Shugoshin, but phosphorylation of histone H3 at threonine 3 (H3pT3) by Haspin failed to show the expected centromeric enrichment on metaphase chromosomes in the zygote. Human cleavage stage embryos show high levels of chromosomal instability. What causes this high error rate is unknown, as mechanisms used to ensure proper chromosome segregation in mammalian embryos are poorly described. In this study, we investigated the pathways regulating CPC targeting to the inner centromere in human embryos. We characterized the distribution of the CPC in relation to activity of its two main centromeric targeting pathways: the Bub1-H2ApT120-Sgo-CPC and Haspin-H3pT3-CPC pathways. The study was conducted between May 2012 and March 2014 on human surplus embryos resulting from in vitro fertilization treatment and donated for research. In zygotes, nuclear envelope breakdown was monitored by time-lapse imaging to allow timed incubations with specific inhibitors to arrest at prometaphase and metaphase, and to interfere with Haspin and Aurora B/C kinase activity. Functionality of the targeting pathways was assessed through characterization of histone phosphorylation dynamics by immunofluorescent analysis, combined with gene expression by RT-qPCR and immunofluorescent localization of key pathway proteins. Immunofluorescent analysis of the CPC subunit Inner Centromere Protein revealed the pool of stably bound CPC proteins was not strictly confined to the inner centromere of prometaphase chromosomes in human zygotes, as observed in later stages of preimplantation development and somatic cells. Investigation of the

  19. Altered sarco(endo)plasmic reticulum calcium adenosine triphosphatase 2a content: Targets for heart failure therapy.

    Science.gov (United States)

    Liu, Gang; Li, Si Qi; Hu, Ping Ping; Tong, Xiao Yong

    2018-05-01

    Sarco(endo)plasmic reticulum calcium adenosine triphosphatase is responsible for transporting cytosolic calcium into the sarcoplasmic reticulum and endoplasmic reticulum to maintain calcium homeostasis. Sarco(endo)plasmic reticulum calcium adenosine triphosphatase is the dominant isoform expressed in cardiac tissue, which is regulated by endogenous protein inhibitors, post-translational modifications, hormones as well as microRNAs. Dysfunction of sarco(endo)plasmic reticulum calcium adenosine triphosphatase is associated with heart failure, which makes sarco(endo)plasmic reticulum calcium adenosine triphosphatase a promising target for heart failure therapy. This review summarizes current approaches to ameliorate sarco(endo)plasmic reticulum calcium adenosine triphosphatase function and focuses on phospholamban, an endogenous inhibitor of sarco(endo)plasmic reticulum calcium adenosine triphosphatase, pharmacological tools and gene therapies.

  20. Copper as a target for prostate cancer therapeutics: copper-ionophore pharmacology and altering systemic copper distribution

    Science.gov (United States)

    Denoyer, Delphine; Pearson, Helen B.; Clatworthy, Sharnel A.S.; Smith, Zoe M.; Francis, Paul S.; Llanos, Roxana M.; Volitakis, Irene; Phillips, Wayne A.; Meggyesy, Peter M.; Masaldan, Shashank; Cater, Michael A.

    2016-01-01

    Copper-ionophores that elevate intracellular bioavailable copper display significant therapeutic utility against prostate cancer cells in vitro and in TRAMP (Transgenic Adenocarcinoma of Mouse Prostate) mice. However, the pharmacological basis for their anticancer activity remains unclear, despite impending clinical trails. Herein we show that intracellular copper levels in prostate cancer, evaluated in vitro and across disease progression in TRAMP mice, were not correlative with copper-ionophore activity and mirrored the normal levels observed in patient prostatectomy tissues (Gleason Score 7 & 9). TRAMP adenocarcinoma cells harbored markedly elevated oxidative stress and diminished glutathione (GSH)-mediated antioxidant capacity, which together conferred selective sensitivity to prooxidant ionophoric copper. Copper-ionophore treatments [CuII(gtsm), disulfiram & clioquinol] generated toxic levels of reactive oxygen species (ROS) in TRAMP adenocarcinoma cells, but not in normal mouse prostate epithelial cells (PrECs). Our results provide a basis for the pharmacological activity of copper-ionophores and suggest they are amendable for treatment of patients with prostate cancer. Additionally, recent in vitro and mouse xenograft studies have suggested an increased copper requirement by prostate cancer cells. We demonstrated that prostate adenocarcinoma development in TRAMP mice requires a functional supply of copper and is significantly impeded by altered systemic copper distribution. The presence of a mutant copper-transporting Atp7b protein (tx mutation: A4066G/Met1356Val) in TRAMP mice changed copper-integration into serum and caused a remarkable reduction in prostate cancer burden (64% reduction) and disease severity (grade), abrogating adenocarcinoma development. Implications for current clinical trials are discussed. PMID:27175597

  1. THE ISLAMIC ETHICS OF MITOCHONDRIA TRANSPLANTATION

    Directory of Open Access Journals (Sweden)

    Anke Iman Bouzenita

    2017-12-01

    Full Text Available ABSTRACT: Biotechnology has opened a new chapter with the advent of mitochondria transplantation for cell-based therapy. Mitochondrial transplantation was successfully led to birth; however, cytoplasmic transplantation has caused apprehension, since the mixing of human ooplasm from two different maternal sources may generate mitochondrial DNA (mtDNA heteroplasmy in the offspring. Islamic legal verdicts on human cloning and somatic cell transfer have been overweighing explicit as to its prohibition, due to the change of creation, mixing of lineage and other evaluations. Is mitochondria transplantation equivalent to human cloning in that genetic information is proliferated and does it, therefore, take the same legal rule? Are there possible benefits (masalih for medical treatment that may render mitochondria transplantation permissible, or are possible harms (mafasid overweighing? Or is it a completely different procedure, taking a different rule? The paper will investigate into these questions and discuss the dimensions of Islamic ethics on the issue.

  2. Agent-Based Modeling of Mitochondria Links Sub-Cellular Dynamics to Cellular Homeostasis and Heterogeneity.

    Directory of Open Access Journals (Sweden)

    Giovanni Dalmasso

    Full Text Available Mitochondria are semi-autonomous organelles that supply energy for cellular biochemistry through oxidative phosphorylation. Within a cell, hundreds of mobile mitochondria undergo fusion and fission events to form a dynamic network. These morphological and mobility dynamics are essential for maintaining mitochondrial functional homeostasis, and alterations both impact and reflect cellular stress states. Mitochondrial homeostasis is further dependent on production (biogenesis and the removal of damaged mitochondria by selective autophagy (mitophagy. While mitochondrial function, dynamics, biogenesis and mitophagy are highly-integrated processes, it is not fully understood how systemic control in the cell is established to maintain homeostasis, or respond to bioenergetic demands. Here we used agent-based modeling (ABM to integrate molecular and imaging knowledge sets, and simulate population dynamics of mitochondria and their response to environmental energy demand. Using high-dimensional parameter searches we integrated experimentally-measured rates of mitochondrial biogenesis and mitophagy, and using sensitivity analysis we identified parameter influences on population homeostasis. By studying the dynamics of cellular subpopulations with distinct mitochondrial masses, our approach uncovered system properties of mitochondrial populations: (1 mitochondrial fusion and fission activities rapidly establish mitochondrial sub-population homeostasis, and total cellular levels of mitochondria alter fusion and fission activities and subpopulation distributions; (2 restricting the directionality of mitochondrial mobility does not alter morphology subpopulation distributions, but increases network transmission dynamics; and (3 maintaining mitochondrial mass homeostasis and responding to bioenergetic stress requires the integration of mitochondrial dynamics with the cellular bioenergetic state. Finally, (4 our model suggests sources of, and stress conditions

  3. Mitochondria and Reactive Oxygen Species: Physiology and Pathophysiology

    Directory of Open Access Journals (Sweden)

    Subhashini Bolisetty

    2013-03-01

    Full Text Available The air that we breathe contains nearly 21% oxygen, most of which is utilized by mitochondria during respiration. While we cannot live without it, it was perceived as a bane to aerobic organisms due to the generation of reactive oxygen and nitrogen metabolites by mitochondria and other cellular compartments. However, this dogma was challenged when these species were demonstrated to modulate cellular responses through altering signaling pathways. In fact, since this discovery of a dichotomous role of reactive species in immune function and signal transduction, research in this field grew at an exponential pace and the pursuit for mechanisms involved began. Due to a significant number of review articles present on the reactive species mediated cell death, we have focused on emerging novel pathways such as autophagy, signaling and maintenance of the mitochondrial network. Despite its role in several processes, increased reactive species generation has been associated with the origin and pathogenesis of a plethora of diseases. While it is tempting to speculate that anti-oxidant therapy would protect against these disorders, growing evidence suggests that this may not be true. This further supports our belief that these reactive species play a fundamental role in maintenance of cellular and tissue homeostasis.

  4. Redox interplay between mitochondria and peroxisomes

    Directory of Open Access Journals (Sweden)

    Celien eLismont

    2015-05-01

    Full Text Available Reduction-oxidation or ‘redox’ reactions are an integral part of a broad range of cellular processes such as gene expression, energy metabolism, protein import and folding, and autophagy. As many of these processes are intimately linked with cell fate decisions, transient or chronic changes in cellular redox equilibrium are likely to contribute to the initiation and progression of a plethora of human diseases. Since a long time, it is known that mitochondria are major players in redox regulation and signaling. More recently, it has become clear that also peroxisomes have the capacity to impact redox-linked physiological processes. To serve this function, peroxisomes cooperate with other organelles, including mitochondria. This review provides a comprehensive picture of what is currently known about the redox interplay between mitochondria and peroxisomes in mammals. We first outline the pro- and antioxidant systems of both organelles and how they may function as redox signaling nodes. Next, we critically review and discuss emerging evidence that peroxisomes and mitochondria share an intricate redox-sensitive relationship and cooperate in cell fate decisions. Key issues include possible physiological roles, messengers, and mechanisms. We also provide examples of how data mining of publicly-available datasets from ‘omics’ technologies can be a powerful means to gain additional insights into potential redox signaling pathways between peroxisomes and mitochondria. Finally, we highlight the need for more studies that seek to clarify the mechanisms of how mitochondria may act as dynamic receivers, integrators, and transmitters of peroxisome-derived mediators of oxidative stress. The outcome of such studies may open up exciting new avenues for the community of researchers working on cellular responses to organelle-derived oxidative stress, a research field in which the role of peroxisomes is currently highly underestimated and an issue of

  5. The effect of amixin and agmatine on cytochrome c release from isolated mitochondria

    Directory of Open Access Journals (Sweden)

    K. R. Uspenska

    2017-02-01

    Full Text Available Mitochondrial nicotinic acetylcholine receptors (nAChRs control permeability transition pore formation and cytochrome c release in the presence of apoptogenic factors. This study demonstrates that pharmacological agents amixin and agmatine affect mitochondrial nAChR functioning: they slightly suppress cytochrome c release from mouse brain and liver mitochondria stimulated with apoptogenic dose of Са2+ and prevent the effect of α7 nAChR agonist PNU282987. We conclude that mitochondria may be one of therapeutic targets of amixin and agmatine.

  6. The effect of anthralin (dithranol) on mitochondria.

    Science.gov (United States)

    Morlière, P; Dubertret, L; Sa e Melo, T; Salet, C; Fosse, M; Santus, R

    1985-05-01

    The short-term effect of topical application of anthralin (dithranol) on normal human skin was investigated by electron microscopy. Mitochondria appeared markedly damaged. By contrast other cellular structures, particularly the nuclear and cytoplasmic membranes were unchanged. In vitro experiments were therefore performed on isolated rat liver mitochondria and it was shown that anthralin acts as an uncoupler of oxidative phosphorylation. These results suggest that anthralin can inhibit the adenosine triphosphate supply in epidermal cells. This loss of energy supply in keratinocytes could explain, at least in part, the therapeutic efficiency of anthralin in psoriasis.

  7. Lactate oxidation in human skeletal muscle mitochondria

    DEFF Research Database (Denmark)

    Jacobs, Robert A; Meinild, Anne-Kristine; Nordsborg, Nikolai B

    2013-01-01

    of four separate and specific substrate titration protocols, the respirometric analysis revealed that mitochondria were capable of oxidizing lactate in the absence of exogenous LDH. The titration of lactate and NAD(+) into the respiration medium stimulated respiration (P = 0.003). The addition...... of exogenous LDH failed to increase lactate-stimulated respiration (P = 1.0). The results further demonstrate that human skeletal muscle mitochondria cannot directly oxidize lactate within the mitochondrial matrix. Alternately, these data support previous claims that lactate is converted to pyruvate within...

  8. The beta-receptor blocker metoprolol alters detoxification processes in the non-target organism Dreissena polymorpha

    Energy Technology Data Exchange (ETDEWEB)

    Contardo-Jara, Valeska, E-mail: contardo@igb-berlin.d [Dpt. Ecophysiology and Aquaculture, Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Mueggelseedamm 301, 12587 Berlin (Germany); Pflugmacher, Stephan, E-mail: pflugmacher@igb-berlin.d [Dpt. Ecophysiology and Aquaculture, Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Mueggelseedamm 301, 12587 Berlin (Germany); Nuetzmann, Gunnar, E-mail: nuetzmann@igb-berlin.d [Dpt. Ecohydrology, Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Mueggelseedamm 301, 12587 Berlin (Germany); Kloas, Werner, E-mail: werner.kloas@igb-berlin.d [Dpt. Ecophysiology and Aquaculture, Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Mueggelseedamm 301, 12587 Berlin (Germany); Wiegand, Claudia, E-mail: wiegand@biology.sdu.d [University of Southern Denmark Institute of Biology, Campusvej 55, 5230 Odense M (Denmark)

    2010-06-15

    Due to increasing amounts of pharmaceutically active compounds (PhACs) in the aquatic environment, their largely unknown effects to non-target organisms need to be assessed. This study examined physiological changes in the freshwater mussel Dreissena polymorpha exposed to increasing concentrations (0.534, 5.34, 53.4 and 534 mug L{sup -1}) of the beta-blocker metoprolol in a flow-through system for seven days. The two lower concentrations represent the environmentally relevant range. Surprisingly, metallothionein mRNA was immediately up-regulated in all treatments. For the two higher concentrations mRNA up-regulation in gills was found for P-glycoprotein after one day, and after four days for pi class glutathione S-transferase, demonstrating elimination and biotransformation processes, respectively. Additionally, catalase and superoxide dismutase were up-regulated in the digestive gland indicating oxidative stress. In all treated mussels a significant up-regulation of heat shock protein mRNA was observed in gills after four days, which suggests protein damage and the requirement for repair processes. Metoprolol was 20-fold bioaccumulated for environmentally relevant concentrations. - Evidence for significant physiological changes in an aquatic mollusc due to exposure to a pharmaceutically active compound detected by real-time PCR.

  9. Targeting the IL-17/IL-6 axis can alter growth of Chronic Lymphocytic Leukemia in vivo/in vitro.

    Science.gov (United States)

    Zhu, Fang; McCaw, Lindsay; Spaner, David E; Gorczynski, Reginald M

    2018-03-01

    The tumor microenvironment (TME) is critical to the longevity of tumor B cells in chronic lymphocytic leukemia (CLL). Bone marrow mesenchymal stem cells (BMMSCs) and the cytokines they produce including IL-6 are important components of the TME in CLL. We found BMMSCs supported the survival of CLL cells in vitro through an IL-6 dependent mechanism. IL-17 which induces IL-6 generation in a variety of cells increased production of IL-6 both in CLL cells and BMMSCs in vitro. In a xenograft CLL mouse model, BMMSCs and the culture supernatant of BMMSCs increased engraftment of CLL cells through an IL-6 mediated mechanism with human recombinant IL-6 showing similar effects in vivo. Human recombinant IL-17 treatment also increased CLL engraftment in mice through an IL-6 mediated mechanism. Plasma of CLL patients showed elevated levels of both IL-6 and IL-17 by ELISA compared with healthy controls, with levels of IL-6 linearly correlated with IL-17 levels. CLL patients requiring fludarabine based chemotherapy expressed higher levels of IL-6 and IL-17, while CLL patients with the lowest levels of IgA/IgM had higher levels of IL-6, but not IL-17. These data imply an important role for the IL-17/IL-6 axis in CLL which could be therapeutic targets. Copyright © 2018 Elsevier Ltd. All rights reserved.

  10. An analysis of the effects of Mn2+ on oxidative phosphorylation in liver, brain, and heart mitochondria using state 3 oxidation rate assays

    International Nuclear Information System (INIS)

    Gunter, Thomas E.; Gerstner, Brent; Lester, Tobias; Wojtovich, Andrew P.; Malecki, Jon; Swarts, Steven G.; Brookes, Paul S.; Gavin, Claire E.; Gunter, Karlene K.

    2010-01-01

    Manganese (Mn) toxicity is partially mediated by reduced ATP production. We have used oxidation rate assays-a measure of ATP production-under rapid phosphorylation conditions to explore sites of Mn 2+ inhibition of ATP production in isolated liver, brain, and heart mitochondria. This approach has several advantages. First, the target tissue for Mn toxicity in the basal ganglia is energetically active and should be studied under rapid phosphorylation conditions. Second, Mn may inhibit metabolic steps which do not affect ATP production rate. This approach allows identification of inhibitions that decrease this rate. Third, mitochondria from different tissues contain different amounts of the components of the metabolic pathways potentially resulting in different patterns of ATP inhibition. Our results indicate that Mn 2+ inhibits ATP production with very different patterns in liver, brain, and heart mitochondria. The primary Mn 2+ inhibition site in liver and heart mitochondria, but not in brain mitochondria, is the F 1 F 0 ATP synthase. In mitochondria fueled by either succinate or glutamate + malate, ATP production is much more strongly inhibited in brain than in liver or heart mitochondria; moreover, Mn 2+ inhibits two independent sites in brain mitochondria. The primary site of Mn-induced inhibition of ATP production in brain mitochondria when succinate is substrate is either fumarase or complex II, while the likely site of the primary inhibition when glutamate plus malate are the substrates is either the glutamate/aspartate exchanger or aspartate aminotransferase.

  11. The Rice Mitochondria Proteome and its Response During Development and to the Environment

    Directory of Open Access Journals (Sweden)

    Shaobai eHuang

    2013-02-01

    Full Text Available Rice (Oryza sativa L. is both a major crop species and the key model grass for molecular and physiological research. Mitochondria are important in rice, as in all crops, as the main source of ATP for cell maintenance and growth. However, the practical significance of understanding the function of mitochondria in rice is increased by the widespread farming practice of using hybrids to boost rice production. This relies on cytoplasmic male-sterile (CMS lines with abortive pollen caused by dysfunctional mitochondria. We provide an overview of what is known about the mitochondrial proteome of rice seedlings. To date, more than 320 proteins have been identified in purified rice mitochondria using mass spectrometry. The insights from this work include a broad understanding of the major subunits of mitochondrial respiratory complexes and TCA cycle enzymes, carbon and nitrogen metabolism enzymes as well as details of the supporting machinery for biogenesis and the subset of stress-responsive mitochondrial proteins. Many proteins with unknown functions have also been found in rice mitochondria. Proteomic analysis has also revealed the features of rice mitochondrial protein presequences required for mitochondrial targeting, as well as cleavage site features for processing of precursors after import. Changes in the abundance of rice mitochondrial proteins in response to different stresses, especially anoxia and light, are summarized. Future research on quantitative analysis of the rice mitochondrial proteomes at the spatial and developmental level, its response to environmental stresses and recent advances in understanding of basis of rice CMS systems are highlighted.

  12. Nerve growth factor alters microtubule targeting agent-induced neurotransmitter release but not MTA-induced neurite retraction in sensory neurons.

    Science.gov (United States)

    Pittman, Sherry K; Gracias, Neilia G; Fehrenbacher, Jill C

    2016-05-01

    Peripheral neuropathy is a dose-limiting side effect of anticancer treatment with the microtubule-targeted agents (MTAs), paclitaxel and epothilone B (EpoB); however, the mechanisms by which the MTAs alter neuronal function and morphology are unknown. We previously demonstrated that paclitaxel alters neuronal sensitivity, in vitro, in the presence of nerve growth factor (NGF). Evidence in the literature suggests that NGF may modulate the neurotoxic effects of paclitaxel. Here, we examine whether NGF modulates changes in neuronal sensitivity and morphology induced by paclitaxel and EpoB. Neuronal sensitivity was assessed using the stimulated release of calcitonin gene-related peptide (CGRP), whereas morphology of established neurites was evaluated using a high content screening system. Dorsal root ganglion cultures, maintained in the absence or presence of NGF, were treated from day 7 to day 12 in culture with paclitaxel (300nM) or EpoB (30nM). Following treatment, the release of CGRP was stimulated using capsaicin or high extracellular potassium. In the presence of NGF, EpoB mimicked the effects of paclitaxel: capsaicin-stimulated release was attenuated, potassium-stimulated release was slightly enhanced and the total peptide content was unchanged. In the absence of NGF, both paclitaxel and EpoB decreased capsaicin- and potassium-stimulated release and the total peptide content, suggesting that NGF may reverse MTA-induced hyposensitivity. Paclitaxel and EpoB both decreased neurite length and branching, and this attenuation was unaffected by NGF in the growth media. These differential effects of NGF on neuronal sensitivity and morphology suggest that neurite retraction is not a causative factor to alter neuronal sensitivity. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. Plasmodium falciparum mitochondria import tRNAs along with an active phenylalanyl-tRNA synthetase.

    Science.gov (United States)

    Sharma, Arvind; Sharma, Amit

    2015-02-01

    The Plasmodium falciparum protein translation enzymes aminoacyl-tRNA synthetases (aaRSs) are an emergent family of drug targets. The aaRS ensemble catalyses transfer of amino acids to cognate tRNAs, thus providing charged tRNAs for ribosomal consumption. P. falciparum proteome expression relies on a total of 36 aaRSs for the three translationally independent compartments of cytoplasm, apicoplast and mitochondria. In the present study, we show that, of this set of 36, a single genomic copy of mitochondrial phenylalanyl-tRNA synthetase (mFRS) is targeted to the parasite mitochondria, and that the mFRS gene is exclusive to malaria parasites within the apicomplexan phyla. Our protein cellular localization studies based on immunofluorescence data show that, along with mFRS, P. falciparum harbours two more phenylalanyl-tRNA synthetase (FRS) assemblies that are localized to its apicoplast and cytoplasm. The 'extra' mFRS is found in mitochondria of all asexual blood stage parasites and is competent in aminoacylation. We show further that the parasite mitochondria import tRNAs from the cytoplasmic tRNA pool. Hence drug targeting of FRSs presents a unique opportunity to potentially stall protein production in all three parasite translational compartments.

  14. Mitochondria in biology and medicine--2012

    DEFF Research Database (Denmark)

    Madsen, Claus Desler; Rasmussen, Lene Juel

    2014-01-01

    as biomarkers for the diseases and most important, it opens the possibility of a treatment or a cure for a disease. "Mitochondria in Biology and Medicine" was the title of the second annual conference of Society of Mitochondrial Research and Medicine-India. The conference was organized by Rana P. Singh, Keshav...

  15. Toxicity of polyhydroxylated fullerene to mitochondria

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Li-Yun [State Key Laboratory of Virology & Key Laboratory of Analytical Chemistry for Biology and Medicine (MOE), College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072 (China); Gao, Jia-Ling [Department of Chemistry, College of Chemistry and Environmental Engineering, Yangtze University, Jingzhou 434023 (China); Gao, Tian; Dong, Ping; Ma, Long; Jiang, Feng-Lei [State Key Laboratory of Virology & Key Laboratory of Analytical Chemistry for Biology and Medicine (MOE), College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072 (China); Liu, Yi, E-mail: yiliuchem@whu.edu.cn [State Key Laboratory of Virology & Key Laboratory of Analytical Chemistry for Biology and Medicine (MOE), College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072 (China)

    2016-01-15

    Highlights: • Fullerenol-induced mitochondrial dysfunction was investigated at mitochondrial level. • Fullerenol disturbed mitochondrial inner membrane in polar protein regions. • Fullerenol affected the inner membrane and respiration chain of mitochondria. - Abstract: Mitochondrial dysfunction is considered as a crucial mechanism of nanomaterial toxicity. Herein, we investigated the effects of polyhydroxylated fullerene (C{sub 60}(OH){sub 44}, fullerenol), a model carbon-based nanomaterial with high water solubility, on isolated mitochondria. Our study demonstrated that fullerenol enhanced the permeabilization of mitochondrial inner membrane to H{sup +} and K{sup +} and induced mitochondrial permeability transition (MPT). The fullerenol-induced swelling was dose-dependent and could be effectively inhibited by MPT inhibitors such as cyclosporin A (CsA), adenosine diphosphate (ADP), ruthenium red (RR) and ethylenediaminetetraacetic acid (EDTA). After treating the mitochondria with fullerenol, the mitochondrial membrane potential (MMP) was found collapsed in a concentration-independent manner. The fluorescence anisotropy of hematoporphyrin (HP) changed significantly with the addition of fullerenol, while that of 1,6-diphenyl-hexatriene (DPH) changed slightly. Moreover, a decrease of respiration state 3 and increase of respiration state 4 were observed when mitochondria were energized with complex II substrate succinate. The results of transmission electron microscopy (TEM) provided direct evidence that fullerenol damaged the mitochondrial ultrastructure. The investigations can provide comprehensive information to elucidate the possible toxic mechanism of fullerenols at subcellular level.

  16. Psychological Stress and Mitochondria: A Systematic Review.

    Science.gov (United States)

    Picard, Martin; McEwen, Bruce S

    Mitochondria are multifunctional life-sustaining organelles that represent a potential intersection point between psychosocial experiences and biological stress responses. This article provides a systematic review of the effects of psychological stress on mitochondrial structure and function. A systematic review of the literature investigating the effects of psychological stress on mitochondrial function was conducted. The review focused on experimentally controlled studies allowing us to draw causal inference about the effect of induced psychological stress on mitochondria. A total of 23 studies met the inclusion criteria. All studies involved male laboratory animals, and most demonstrated that acute and chronic stressors influenced specific facets of mitochondrial function, particularly within the brain. Nineteen studies showed significant adverse effects of psychological stress on mitochondria and four found increases in function or size after stress. In humans, only six observational studies were available, none with experimental designs, and most only measured biological markers that do not directly reflect mitochondrial function, such as mitochondrial DNA copy number. Overall, evidence supports the notion that acute and chronic stressors influence various aspects of mitochondrial biology, and that chronic stress exposure can lead to molecular and functional recalibrations among mitochondria. Limitations of current animal and human studies are discussed. Maladaptive mitochondrial changes that characterize this subcellular state of stress are termed mitochondrial allostatic load. Prospective studies with sensitive measures of specific mitochondrial outcomes will be needed to establish the link between psychosocial stressors, emotional states, the resulting neuroendocrine and immune processes, and mitochondrial energetics relevant to mind-body research in humans.

  17. The antileishmanial agent licochalcone A interferes with the function of parasite mitochondria

    DEFF Research Database (Denmark)

    Zhai, L; Blom, J; Chen, M

    1995-01-01

    . Khrazmi, Antimicrob. Agents Chemother. 38:1339-1344, 1994) and antimalarial (M. Chen, T.G. Theander, S.B. Christensen, L. Hviid, L. Zhai, and A. Kaharazmi, Antimicrob. Agents Chemother. 38:1470-1475, 1994) activities. We have observed that licochalcone A alters the ultrastructure of the mitochondria...... of Leishmania promastigotes (Chen et al., Antimicrob. Agents Chemother. 37:2550-2556, 1993). The present study was designed to examine this observation further and investigate the mechanism of action of antileishmanial activity of licochalcone A. Electron microscopic studies showed that licochalcone A altered...... of the parasite by the parasites. Moreover, licochalcone A inhibited the activity of the parasite mitochondrial dehydrogenase. The inhibition of the activity of the parasite mitochondrial enzyme correlated well with the changes in the ultrastructure of the mitochondria shown by electron microscopy. These findings...

  18. Neuroprotection and Anti-Epileptogenesis with Mitochondria-Targeted Antioxidant

    Science.gov (United States)

    2016-06-01

    Nissl , Fluoro-jade C (FJ), NeuN and heat shock protein 70-72 (HSP). Nissl , FJ and NeuN stains were used to assess neuroprotection. HSP was used to...days after SE. The brains were removed and sectioned on a vibratome (50µm) throughout the dorsal hippocampus. Sections were stained for Nissl ...2.5mg/kg (n=2). Nissl - stained sections from the left hemisphere of each brain were evaluated for damage and scored using the following scale: 1

  19. A non-toxic fluorogenic dye for mitochondria labeling.

    Science.gov (United States)

    Han, Junyan; Han, Myung Shin; Tung, Ching-Hsuan

    2013-11-01

    Mitochondria, powerhouses of cells, are responsible for many critical cellular functions, such as cell energy metabolism, reactive oxygen species production, and apoptosis regulation. Monitoring mitochondria morphology in live cells temporally and spatially could help with the understanding of the mechanisms of mitochondrial functional regulation and the pathogenesis of mitochondria-related diseases. A novel non-cytotoxic fluorogenic compound, AcQCy7, was developed as a mitochondria-specific dye. AcQCy7 emitted no fluorescent signal outside of cells, but it became fluorescent after intracellular hydrolysis of the acetyl group. The hydrolyzed fluorescent product was well retained in mitochondria, enabling long-lasting fluorescence imaging of mitochondria without cell washing. A 2-day culture study using AcQCy7 showed no sign of cytotoxicity, whereas a commonly used mitochondria-staining probe, Mitochondria Tracker Green, caused significant cell death even at a much lower concentration. Apoptosis-causing mitochondria fission was monitored clearly in real time by AcQCy7. A simple add-and-read mitochondria specific dye AcQCy7 has been validated in various cell models. Bright mitochondria specific fluorescent signal in treated cells lasted several days without noticeable toxicity. The probe AcQCy7 has been proofed to be a non-toxic agent for long-term mitochondria imaging. © 2013.

  20. Effect of simvastatin on vascular tone in porcine coronary artery: Potential role of the mitochondria

    International Nuclear Information System (INIS)

    Almukhtar, H.; Garle, M.J.; Smith, P.A.; Roberts, R.E.

    2016-01-01

    Statins induce acute vasorelaxation which may contribute to the overall benefits of statins in the treatment of cardiovascular disease. The mechanism underlying this relaxation is unknown. As statins have been shown to alter mitochondrial function, in this study we investigated the role of mitochondria in the relaxation to simvastatin. Relaxation of porcine coronary artery segments by statins was measured using isolated tissue baths. Mitochondrial activity was determined by measuring changes in rhodamine 123 fluorescence. Changes in intracellular calcium levels were determined in freshly isolated smooth muscle cells with Fluo-4 using standard epifluorescent imaging techniques. Simvastatin, but not pravastatin, produced a slow relaxation of the coronary artery, which was independent of the endothelium. The relaxation was attenuated by the mitochondrial complex I inhibitor rotenone (10 μM) and the complex III inhibitor myxothiazol (10 μM), or a combination of the two. The complex III inhibitor antimycin A (10 μM) produced a similar time-dependent relaxation of the porcine coronary artery, which was attenuated by rotenone. Changes in rhodamine 123 fluorescence showed that simvastatin (10 μM) depolarized the membrane potential of mitochondria in both isolated mitochondria and intact blood vessels. Simvastatin and antimycin A both inhibited calcium-induced contractions in isolated blood vessels and calcium influx in smooth muscle cells and this inhibition was prevented by rotenone. In conclusion, simvastatin produces an endothelium-independent relaxation of the porcine coronary artery which is dependent, in part, upon effects on the mitochondria. The effects on the mitochondria may lead to a reduction in calcium influx and hence relaxation of the blood vessel. - Highlights: • Simvastatin produces a relaxation of the porcine coronary artery. • This relaxation is inhibited by mitochondrial complex inhibitors. • Simvastatin alters mitochondrial membrane potential

  1. Effect of simvastatin on vascular tone in porcine coronary artery: Potential role of the mitochondria

    Energy Technology Data Exchange (ETDEWEB)

    Almukhtar, H.; Garle, M.J.; Smith, P.A.; Roberts, R.E., E-mail: richard.roberts@nottingham.ac.uk

    2016-08-15

    Statins induce acute vasorelaxation which may contribute to the overall benefits of statins in the treatment of cardiovascular disease. The mechanism underlying this relaxation is unknown. As statins have been shown to alter mitochondrial function, in this study we investigated the role of mitochondria in the relaxation to simvastatin. Relaxation of porcine coronary artery segments by statins was measured using isolated tissue baths. Mitochondrial activity was determined by measuring changes in rhodamine 123 fluorescence. Changes in intracellular calcium levels were determined in freshly isolated smooth muscle cells with Fluo-4 using standard epifluorescent imaging techniques. Simvastatin, but not pravastatin, produced a slow relaxation of the coronary artery, which was independent of the endothelium. The relaxation was attenuated by the mitochondrial complex I inhibitor rotenone (10 μM) and the complex III inhibitor myxothiazol (10 μM), or a combination of the two. The complex III inhibitor antimycin A (10 μM) produced a similar time-dependent relaxation of the porcine coronary artery, which was attenuated by rotenone. Changes in rhodamine 123 fluorescence showed that simvastatin (10 μM) depolarized the membrane potential of mitochondria in both isolated mitochondria and intact blood vessels. Simvastatin and antimycin A both inhibited calcium-induced contractions in isolated blood vessels and calcium influx in smooth muscle cells and this inhibition was prevented by rotenone. In conclusion, simvastatin produces an endothelium-independent relaxation of the porcine coronary artery which is dependent, in part, upon effects on the mitochondria. The effects on the mitochondria may lead to a reduction in calcium influx and hence relaxation of the blood vessel. - Highlights: • Simvastatin produces a relaxation of the porcine coronary artery. • This relaxation is inhibited by mitochondrial complex inhibitors. • Simvastatin alters mitochondrial membrane potential

  2. Ultrastructural alterations in adult Schistosoma mansoni caused by artemether

    Directory of Open Access Journals (Sweden)

    Shuhua Xiao

    2002-07-01

    Full Text Available Progress has been made over the last decade with the development and clinical use of artemether as an agent against major human schistosome parasites. The tegument has been identified as a key target of artemether, implying detailed studies on ultrastructural damage induced by this compound. We performed a temporal examination, employing a transmission electron microscope to assess the pattern and extent of ultrastructural alterations in adult Schistosoma mansoni harboured in mice treated with a single dose of 400 mg/kg artemether. Eight hours post-treatment, damage to the tegument and subtegumental structures was seen. Tegumental alterations reached a peak 3 days after treatment and were characterized by swelling, fusion of distal cytoplasma, focal lysis of the tegumental matrix and vacuolisation. Tubercles and sensory organelles frequently degenerated or collapsed. Typical features of subtegumental alterations, including muscle fibres, syncytium and parenchyma tissues, were focal or extensive lysis, vacuolisation and degeneration of mitochondria. Severe alterations were also observed in gut epithelial cells and vitelline cells of female worms. Our findings of artemether-induced ultrastructural alterations in adult S. mansoni confirm previous results obtained with juvenile S. mansoni and S. japonicum of different ages.

  3. Proteomic analysis of mitochondria in respiratory epithelial cells infected with human respiratory syncytial virus and functional implications for virus and cell biology.

    Science.gov (United States)

    Munday, Diane C; Howell, Gareth; Barr, John N; Hiscox, Julian A

    2015-03-01

    The aim of this study was to quantitatively characterise the mitochondrial proteome of airway epithelial cells infected with human respiratory syncytial virus (HRSV), a major cause of paediatric illness. Quantitative proteomics, underpinned by stable isotope labelling with amino acids in cell culture, coupled to LC-MS/MS, was applied to mitochondrial fractions prepared from HRSV-infected and mock-infected cells 12 and 24 h post-infection. Datasets were analysed using ingenuity pathway analysis, and the results were validated and characterised using bioimaging, targeted inhibition and gene depletion. The data quantitatively indicated that antiviral signalling proteins converged on mitochondria during HRSV infection. The mitochondrial receptor protein Tom70 was found to act in an antiviral manner, while its chaperone, Hsp90, was confirmed to be a positive viral factor. Proteins associated with different organelles were also co-enriched in the mitochondrial fractions from HRSV-infected cells, suggesting that alterations in organelle dynamics and membrane associations occur during virus infection. Protein and pathway-specific alterations occur to the mitochondrial proteome in a spatial and temporal manner during HRSV infection, suggesting that this organelle may have altered functions. These could be targeted as part of potential therapeutic strategies to disrupt virus biology. © 2014 Royal Pharmaceutical Society.

  4. Lipid droplets interact with mitochondria using SNAP23

    DEFF Research Database (Denmark)

    Jägerström, Sara; Polesie, Sam; Wickström, Ylva

    2009-01-01

    peroxisomes and the endoplasmic reticulum. We have used electron and confocal microscopy to demonstrate that LD form complexes with mitochondria in NIH 3T3 fibroblasts. Using an in vitro system of purified LD and mitochondria, we also show the formation of the LD-mitochondria complex, in which cytosolic...... factors are involved. Moreover, the presence of LD markers in mitochondria isolated by subcellular fractionations is demonstrated. Finally, ablation of SNAP23 using siRNA reduced complex formation and beta oxidation, which suggests that the LD-mitochondria complex is functional in the cell....

  5. Physical exercise in aging human skeletal muscle increases mitochondrial calcium uniporter expression levels and affects mitochondria dynamics.

    Science.gov (United States)

    Zampieri, Sandra; Mammucari, Cristina; Romanello, Vanina; Barberi, Laura; Pietrangelo, Laura; Fusella, Aurora; Mosole, Simone; Gherardi, Gaia; Höfer, Christian; Löfler, Stefan; Sarabon, Nejc; Cvecka, Jan; Krenn, Matthias; Carraro, Ugo; Kern, Helmut; Protasi, Feliciano; Musarò, Antonio; Sandri, Marco; Rizzuto, Rosario

    2016-12-01

    Age-related sarcopenia is characterized by a progressive loss of muscle mass with decline in specific force, having dramatic consequences on mobility and quality of life in seniors. The etiology of sarcopenia is multifactorial and underlying mechanisms are currently not fully elucidated. Physical exercise is known to have beneficial effects on muscle trophism and force production. Alterations of mitochondrial Ca 2+ homeostasis regulated by mitochondrial calcium uniporter (MCU) have been recently shown to affect muscle trophism in vivo in mice. To understand the relevance of MCU-dependent mitochondrial Ca 2+ uptake in aging and to investigate the effect of physical exercise on MCU expression and mitochondria dynamics, we analyzed skeletal muscle biopsies from 70-year-old subjects 9 weeks trained with either neuromuscular electrical stimulation (ES) or leg press. Here, we demonstrate that improved muscle function and structure induced by both trainings are linked to increased protein levels of MCU Ultrastructural analyses by electron microscopy showed remodeling of mitochondrial apparatus in ES-trained muscles that is consistent with an adaptation to physical exercise, a response likely mediated by an increased expression of mitochondrial fusion protein OPA1. Altogether these results indicate that the ES-dependent physiological effects on skeletal muscle size and force are associated with changes in mitochondrial-related proteins involved in Ca 2+ homeostasis and mitochondrial shape. These original findings in aging human skeletal muscle confirm the data obtained in mice and propose MCU and mitochondria-related proteins as potential pharmacological targets to counteract age-related muscle loss. © 2016 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.

  6. A structured approach to the study of metabolic control principles in intact and impaired mitochondria.

    Science.gov (United States)

    Huber, Heinrich J; Connolly, Niamh M C; Dussmann, Heiko; Prehn, Jochen H M

    2012-03-01

    We devised an approach to extract control principles of cellular bioenergetics for intact and impaired mitochondria from ODE-based models and applied it to a recently established bioenergetic model of cancer cells. The approach used two methods for varying ODE model parameters to determine those model components that, either alone or in combination with other components, most decisively regulated bioenergetic state variables. We found that, while polarisation of the mitochondrial membrane potential (ΔΨ(m)) and, therefore, the protomotive force were critically determined by respiratory complex I activity in healthy mitochondria, complex III activity was dominant for ΔΨ(m) during conditions of cytochrome-c deficiency. As a further important result, cellular bioenergetics in healthy, ATP-producing mitochondria was regulated by three parameter clusters that describe (1) mitochondrial respiration, (2) ATP production and consumption and (3) coupling of ATP-production and respiration. These parameter clusters resembled metabolic blocks and their intermediaries from top-down control analyses. However, parameter clusters changed significantly when cells changed from low to high ATP levels or when mitochondria were considered to be impaired by loss of cytochrome-c. This change suggests that the assumption of static metabolic blocks by conventional top-down control analyses is not valid under these conditions. Our approach is complementary to both ODE and top-down control analysis approaches and allows a better insight into cellular bioenergetics and its pathological alterations.

  7. Deregulation of Mitochondria-Shaping Proteins Opa-1 and Drp-1 in Manganese-Induced Apoptosis

    Science.gov (United States)

    Alaimo, Agustina; Gorojod, Roxana M.; Beauquis, Juan; Muñoz, Manuel J.; Saravia, Flavia; Kotler, Mónica L.

    2014-01-01

    Mitochondria are dynamic organelles that undergo fusion and fission processes. These events are regulated by mitochondria-shaping proteins. Changes in the expression and/or localization of these proteins lead to a mitochondrial dynamics impairment and may promote apoptosis. Increasing evidence correlates the mitochondrial dynamics disruption with the occurrence of neurodegenerative diseases. Therefore, we focused on this topic in Manganese (Mn)-induced Parkinsonism, a disorder associated with Mn accumulation preferentially in the basal ganglia where mitochondria from astrocytes represent an early target. Using MitoTracker Red staining we observed increased mitochondrial network fission in Mn-exposed rat astrocytoma C6 cells. Moreover, Mn induced a marked decrease in fusion protein Opa-1 levels as well as a dramatic increase in the expression of fission protein Drp-1. Additionally, Mn provoked a significant release of high MW Opa-1 isoforms from the mitochondria to the cytosol as well as an increased Drp-1 translocation to the mitochondria. Both Mdivi-1, a pharmacological Drp-1 inhibitor, and rat Drp-1 siRNA reduced the number of apoptotic nuclei, preserved the mitochondrial network integrity and prevented cell death. CsA, an MPTP opening inhibitor, prevented mitochondrial Δψm disruption, Opa-1 processing and Drp-1 translocation to the mitochondria therefore protecting Mn-exposed cells from mitochondrial disruption and apoptosis. The histological analysis and Hoechst 33258 staining of brain sections of Mn-injected rats in the striatum showed a decrease in cellular mass paralleled with an increase in the occurrence of apoptotic nuclei. Opa-1 and Drp-1 expression levels were also changed by Mn-treatment. Our results demonstrate for the first time that abnormal mitochondrial dynamics is implicated in both in vitro and in vivo Mn toxicity. In addition we show that the imbalance in fusion/fission equilibrium might be involved in Mn-induced apoptosis. This knowledge may

  8. Deregulation of mitochondria-shaping proteins Opa-1 and Drp-1 in manganese-induced apoptosis.

    Directory of Open Access Journals (Sweden)

    Agustina Alaimo

    Full Text Available Mitochondria are dynamic organelles that undergo fusion and fission processes. These events are regulated by mitochondria-shaping proteins. Changes in the expression and/or localization of these proteins lead to a mitochondrial dynamics impairment and may promote apoptosis. Increasing evidence correlates the mitochondrial dynamics disruption with the occurrence of neurodegenerative diseases. Therefore, we focused on this topic in Manganese (Mn-induced Parkinsonism, a disorder associated with Mn accumulation preferentially in the basal ganglia where mitochondria from astrocytes represent an early target. Using MitoTracker Red staining we observed increased mitochondrial network fission in Mn-exposed rat astrocytoma C6 cells. Moreover, Mn induced a marked decrease in fusion protein Opa-1 levels as well as a dramatic increase in the expression of fission protein Drp-1. Additionally, Mn provoked a significant release of high MW Opa-1 isoforms from the mitochondria to the cytosol as well as an increased Drp-1 translocation to the mitochondria. Both Mdivi-1, a pharmacological Drp-1 inhibitor, and rat Drp-1 siRNA reduced the number of apoptotic nuclei, preserved the mitochondrial network integrity and prevented cell death. CsA, an MPTP opening inhibitor, prevented mitochondrial Δψm disruption, Opa-1 processing and Drp-1 translocation to the mitochondria therefore protecting Mn-exposed cells from mitochondrial disruption and apoptosis. The histological analysis and Hoechst 33258 staining of brain sections of Mn-injected rats in the striatum showed a decrease in cellular mass paralleled with an increase in the occurrence of apoptotic nuclei. Opa-1 and Drp-1 expression levels were also changed by Mn-treatment. Our results demonstrate for the first time that abnormal mitochondrial dynamics is implicated in both in vitro and in vivo Mn toxicity. In addition we show that the imbalance in fusion/fission equilibrium might be involved in Mn-induced apoptosis

  9. Deregulation of mitochondria-shaping proteins Opa-1 and Drp-1 in manganese-induced apoptosis.

    Science.gov (United States)

    Alaimo, Agustina; Gorojod, Roxana M; Beauquis, Juan; Muñoz, Manuel J; Saravia, Flavia; Kotler, Mónica L

    2014-01-01

    Mitochondria are dynamic organelles that undergo fusion and fission processes. These events are regulated by mitochondria-shaping proteins. Changes in the expression and/or localization of these proteins lead to a mitochondrial dynamics impairment and may promote apoptosis. Increasing evidence correlates the mitochondrial dynamics disruption with the occurrence of neurodegenerative diseases. Therefore, we focused on this topic in Manganese (Mn)-induced Parkinsonism, a disorder associated with Mn accumulation preferentially in the basal ganglia where mitochondria from astrocytes represent an early target. Using MitoTracker Red staining we observed increased mitochondrial network fission in Mn-exposed rat astrocytoma C6 cells. Moreover, Mn induced a marked decrease in fusion protein Opa-1 levels as well as a dramatic increase in the expression of fission protein Drp-1. Additionally, Mn provoked a significant release of high MW Opa-1 isoforms from the mitochondria to the cytosol as well as an increased Drp-1 translocation to the mitochondria. Both Mdivi-1, a pharmacological Drp-1 inhibitor, and rat Drp-1 siRNA reduced the number of apoptotic nuclei, preserved the mitochondrial network integrity and prevented cell death. CsA, an MPTP opening inhibitor, prevented mitochondrial Δψm disruption, Opa-1 processing and Drp-1 translocation to the mitochondria therefore protecting Mn-exposed cells from mitochondrial disruption and apoptosis. The histological analysis and Hoechst 33258 staining of brain sections of Mn-injected rats in the striatum showed a decrease in cellular mass paralleled with an increase in the occurrence of apoptotic nuclei. Opa-1 and Drp-1 expression levels were also changed by Mn-treatment. Our results demonstrate for the first time that abnormal mitochondrial dynamics is implicated in both in vitro and in vivo Mn toxicity. In addition we show that the imbalance in fusion/fission equilibrium might be involved in Mn-induced apoptosis. This knowledge may

  10. Cardiovascular Disease, Mitochondria, and Traditional Chinese Medicine

    Directory of Open Access Journals (Sweden)

    Jie Wang

    2015-01-01

    Full Text Available Recent studies demonstrated that mitochondria play an important role in the cardiovascular system and mutations of mitochondrial DNA affect coronary artery disease, resulting in hypertension, atherosclerosis, and cardiomyopathy. Traditional Chinese medicine (TCM has been used for thousands of years to treat cardiovascular disease, but it is not yet clear how TCM affects mitochondrial function. By reviewing the interactions between the cardiovascular system, mitochondrial DNA, and TCM, we show that cardiovascular disease is negatively affected by mutations in mitochondrial DNA and that TCM can be used to treat cardiovascular disease by regulating the structure and function of mitochondria via increases in mitochondrial electron transport and oxidative phosphorylation, modulation of mitochondrial-mediated apoptosis, and decreases in mitochondrial ROS. However further research is still required to identify the mechanism by which TCM affects CVD and modifies mitochondrial DNA.

  11. Fluoroacetylcarnitine: metabolism and metabolic effects in mitochondria

    Energy Technology Data Exchange (ETDEWEB)

    Bremer, J; Davis, E J

    1973-01-01

    The metabolism and metabolic effects of fluoroacetylcarnitine have been investigated. Carnitineacetyltransferase transfers the fluoro-acetyl group of fluoroacetylcarnitine nearly as rapidly to CoA as the acetyl group of acetylcarnitine. Fluorocitrate is then formed by citrate synthase, but this second reaction is relatively slow. The fluorocitrate formed intramitochondrially inhibits the metabolism of citrate. In heart and skeletal muscle mitochondria the accumulated citrate inhibits citrate synthesis and the ..beta..-oxidation of fatty acids. Free acetate is formed, presumably because accumulated acetyl-CoA is hydrolyzed. In liver mitochondria the accumulation of citrate leads to a relatively increased rate of ketogenesis. Increased ketogenesis is obtained also upon the addition of citrate to the reaction mixture.

  12. Response of skeletal muscle mitochondria to hypoxia.

    Science.gov (United States)

    Hoppeler, Hans; Vogt, Michael; Weibel, Ewald R; Flück, Martin

    2003-01-01

    This review explores the current concepts relating the structural and functional modifications of skeletal muscle mitochondria to the molecular mechanisms activated when organisms are exposed to a hypoxic environment. In contrast to earlier assumptions it is now established that permanent or long-term exposure to severe environmental hypoxia decreases the mitochondrial content of muscle fibres. Oxidative muscle metabolism is shifted towards a higher reliance on carbohydrates as a fuel, and intramyocellular lipid substrate stores are reduced. Moreover, in muscle cells of mountaineers returning from the Himalayas, we find accumulations of lipofuscin, believed to be a mitochondrial degradation product. Low mitochondrial contents are also observed in high-altitude natives such as Sherpas. In these subjects high-altitude performance seems to be improved by better coupling between ATP demand and supply pathways as well as better metabolite homeostasis. The hypoxia-inducible factor 1 (HIF-1) has been identified as a master regulator for the expression of genes involved in the hypoxia response, such as genes coding for glucose transporters, glycolytic enzymes and vascular endothelial growth factor (VEGF). HIF-1 achieves this by binding to hypoxia response elements in the promoter regions of these genes, whereby the increase of HIF-1 in hypoxia is the consequence of a reduced degradation of its dominant subunit HIF-1a. A further mechanism that seems implicated in the hypoxia response of muscle mitochondria is related to the formation of reactive oxygen species (ROS) in mitochondria during oxidative phosphorylation. How exactly ROS interfere with HIF-1a as well as MAP kinase and other signalling pathways is debated. The current evidence suggests that mitochondria themselves could be important players in oxygen sensing.

  13. Pyruvate transport by thermogenic-tissue mitochondria.

    OpenAIRE

    Proudlove, M O; Beechey, R B; Moore, A L

    1987-01-01

    1. Mitochondria isolated from the thermogenic spadices of Arum maculatum and Sauromatum guttatum plants oxidized external NADH, succinate, citrate, malate, 2-oxoglutarate and pyruvate without the need to add exogenous cofactors. 2. Oxidation of substrates was virtually all via the alternative oxidase, the cytochrome pathway constituting only 10-20% of the total activity, depending on the stage of spadix development. 3. During later stages of spadix development, pyruvate oxidation was enhanced...

  14. Regulation of protein phosphorylation in oat mitochondria

    International Nuclear Information System (INIS)

    Pike, C.; Kopeck, K.; Sceppa, E.

    1989-01-01

    We sought to identify phosphorylated proteins in isolated oat mitocchondria and to characterize the enzymatic and regulatory properties of the protein kinase(s). Mitochondria from oats (Avena sativa L. cv. Garry) were purified on Percoll gradients. Mitochondria were incubated with 32 P-γ-ATP; proteins were separated by SDS-PAGE. A small number of bands was detected on autoradiograms, most prominently at 70 kD and 42 kD; the latter band has been tentatively identified as a subunit of the pyruvate dehydrogenase complex, a well-known phosphoprotein. The protein kinase(s) could also phosphorylate casein, but not histone. Spermine enhanced the phosphorylation of casein and inhibited the phosphorylation of the 42 kD band. These studies were carried out on both intact and burst mitochondria. Control by calcium and other ions was investigated. The question of the action of regulators on protein kinase or protein phosphatase was studied by the use of 35 S-adenosine thiotriphosphate

  15. Mitochondria in anthropology and forensic medicine.

    Science.gov (United States)

    Grzybowski, Tomasz; Rogalla, Urszula

    2012-01-01

    Mitochondria's role in crucial metabolic pathways is probably the first answer which comes to our minds for the question: what do these tiny organelles serve for? However, specific features of their DNA made them extremely useful also in the field of anthropology and forensics. MtDNA analyses became a milestone in the complex task of unraveling earliest human migrations. Evidence provided by these experiments left no doubts on modern humans origins pointing to Africa being our cradle. It also contributed to interpretation of putative ways of our dispersal around Asia and Americas thousands years ago. On the other hand, analysis of mtDNA is well established and valuable tool in forensic genetics. When other definitely more popular markers give no answer on identity, it is the time to employ information carried by mitochondria. This chapter summarizes not only current reports on the role of mitochondria in forensics and reconstruction of modern humans phylogeny, but also calls one's attention to a broad range of difficulties and constraints associated with mtDNA analyses.

  16. Role of mitochondria in parvovirus pathology.

    Directory of Open Access Journals (Sweden)

    Jonna Nykky

    Full Text Available Proper functioning of the mitochondria is crucial for the survival of the cell. Viruses are able to interfere with mitochondrial functions as they infect the host cell. Parvoviruses are known to induce apoptosis in infected cells, but the role of the mitochondria in parvovirus induced cytopathy is only partially known. Here we demonstrate with confocal and electron microscopy that canine parvovirus (CPV associated with the mitochondrial outer membrane from the onset of infection. During viral entry a transient depolarization of the mitochondrial transmembrane potential and increase in ROS level was detected. Subsequently, mitochondrial homeostasis was normalized shortly, as detected by repolarization of the mitochondrial membrane and decrease of ROS. Indeed, activation of cell survival signalling through ERK1/2 cascade was observed early in CPV infected cells. At 12 hours post infection, concurrent with the expression of viral non-structural protein 1, damage to the mitochondrial structure and depolarization of its membrane were apparent. Results of this study provide additional insight of parvovirus pathology and also more general information of virus-mitochondria association.

  17. Mitochondria and the evolutionary roots of cancer

    International Nuclear Information System (INIS)

    Davila, Alfonso F; Zamorano, Pedro

    2013-01-01

    Cancer disease is inherent to, and widespread among, metazoans. Yet, some of the hallmarks of cancer such as uncontrolled cell proliferation, lack of apoptosis, hypoxia, fermentative metabolism and free cell motility (metastasis) are akin to a prokaryotic lifestyle, suggesting a link between cancer disease and evolution. In this hypothesis paper, we propose that cancer cells represent a phenotypic reversion to the earliest stage of eukaryotic evolution. This reversion is triggered by the dysregulation of the mitochondria due to cumulative oxidative damage to mitochondrial and nuclear DNA. As a result, the phenotype of normal, differentiated cells gradually reverts to the phenotype of a facultative anaerobic, heterotrophic cell optimized for survival and proliferation in hypoxic environments. This phenotype matches the phenotype of the last eukaryotic common ancestor (LECA) that resulted from the endosymbiosis between an α-proteobacteria (which later became the mitochondria) and an archaebacteria. As such, the evolution of cancer within one individual can be viewed as a recapitulation of the evolution of the eukaryotic cell from fully differentiated cells to LECA. This evolutionary model of cancer is compatible with the current understanding of the disease, and explains the evolutionary basis for most of the hallmarks of cancer, as well as the link between the disease and aging. It could also open new avenues for treatment directed at reestablishing the synergy between the mitochondria and the cancerous cell. (paper)

  18. Novel cellular targets of AhR underlie alterations in neutrophilic inflammation and iNOS expression during influenza virus infection

    Science.gov (United States)

    Head Wheeler, Jennifer L.; Martin, Kyle C.; Lawrence, B. Paige

    2012-01-01

    The underlying reasons for variable clinical outcomes from respiratory viral infections remain uncertain. Several studies suggest that environmental factors contribute to this variation, but limited knowledge of cellular and molecular targets of these agents hampers our ability to quantify or modify their contribution to disease and improve public health. The aryl hydrocarbon receptor (AhR) is an environment sensing transcription factor that binds many anthropogenic and natural chemicals. The immunomodulatory properties of AhR ligands are best characterized with extensive studies of changes in CD4+ T cell responses. Yet, AhR modulates other aspects of immune function. We previously showed that during influenza virus infection, AhR activation modulates neutrophil accumulation in the lung, and this contributes to increased mortality in mice. Enhanced levels of inducible nitric oxide synthase (iNOS) in infected lungs are observed during the same timeframe as AhR-mediated increased pulmonary neutrophilia. In this study, we evaluated whether these two consequences of AhR activation are causally linked. Reciprocal inhibition of AhR-mediated elevations in iNOS and pulmonary neutrophilia reveal that, although they are contemporaneous, they are not causally related. We show using Cre/loxP technology that elevated iNOS levels and neutrophil number in the infected lung result from separate, AhR-dependent signaling in endothelial and respiratory epithelial cells, respectively. Studies using mutant mice further reveal that AhR-mediated alterations in these innate responses to infection require a functional nuclear localization signal and DNA binding domain. Thus, gene targets of AhR in non-hematopoietic cells are important new considerations for understanding AhR-mediated changes in innate anti-viral immunity. PMID:23233726

  19. Calcium regulates cell death in cancer: Roles of the mitochondria and mitochondria-associated membranes (MAMs).

    Science.gov (United States)

    Danese, Alberto; Patergnani, Simone; Bonora, Massimo; Wieckowski, Mariusz R; Previati, Maurizio; Giorgi, Carlotta; Pinton, Paolo

    2017-08-01

    Until 1972, the term 'apoptosis' was used to differentiate the programmed cell death that naturally occurs in organismal development from the acute tissue death referred to as necrosis. Many studies on cell death and programmed cell death have been published and most are, at least to some degree, related to cancer. Some key proteins and molecular pathways implicated in cell death have been analyzed, whereas others are still being actively researched; therefore, an increasing number of cellular compartments and organelles are being implicated in cell death and cancer. Here, we discuss the mitochondria and subdomains of the endoplasmic reticulum (ER) that interact with mitochondria, the mitochondria-associated membranes (MAMs), which have been identified as critical hubs in the regulation of cell death and tumor growth. MAMs-dependent calcium (Ca 2+ ) release from the ER allows selective Ca 2+ uptake by the mitochondria. The perturbation of Ca 2+ homeostasis in cancer cells is correlated with sustained cell proliferation and the inhibition of cell death through the modulation of Ca 2+ signaling. This article is part of a Special Issue entitled Mitochondria in Cancer, edited by Giuseppe Gasparre, Rodrigue Rossignol and Pierre Sonveaux. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Apoptotic role of TGF-β mediated by Smad4 mitochondria translocation and cytochrome c oxidase subunit II interaction.

    Science.gov (United States)

    Pang, Lijuan; Qiu, Tao; Cao, Xu; Wan, Mei

    2011-07-01

    Smad4, originally isolated from the human chromosome 18q21, is a key factor in transducing the signals of the TGF-β superfamily of growth hormones and plays a pivotal role in mediating antimitogenic and proapoptotic effects of TGF-β, but the mechanisms by which Smad4 induces apoptosis are elusive. Here we report that Smad4 directly translocates to the mitochondria of apoptotic cells. Smad4 gene silencing by siRNA inhibits TGF-β-induced apoptosis in Hep3B cells and UV-induced apoptosis in PANC-1 cells. Cell fractionation assays demonstrated that a fraction of Smad4 translocates to mitochondria after long time TGF-β treatment or UV exposure, during which the cells were under apoptosis. Smad4 mitochondria translocation during apoptosis was also confirmed by fluorescence observation of Smad4 colocalization with MitoTracker Red. We searched for mitochondria proteins that have physical interactions with Smad4 using yeast two-hybrid screening approach. DNA sequence analysis identified 34 positive clones, five of which encoded subunits in mitochondria complex IV, i.e., one clone encoded cytochrome c oxidase COXII, three clones encoded COXIII and one clone encoded COXVb. Strong interaction between Smad4 with COXII, an important apoptosis regulator, was verified in yeast by β-gal activity assays and in mammalian cells by immunoprecipitation assays. Further, mitochondrial portion of cells was isolated and the interaction between COXII and Smad4 in mitochondria upon TGF-β treatment or UV exposure was confirmed. Importantly, targeting Smad4 to mitochondria using import leader fusions enhanced TGF-β-induced apoptosis. Collectively, the results suggest that Smad4 promote apoptosis of the cells through its mitochondrial translocation and association with mitochondria protein COXII. Copyright © 2011 Elsevier Inc. All rights reserved.

  1. The Myriad Roles of Miro in the Nervous System: Axonal Transport of Mitochondria and Beyond

    Directory of Open Access Journals (Sweden)

    Bingwei eLu

    2014-10-01

    Full Text Available Mitochondrial rho GTPase (Miro is a mitochondrial outer membrane protein containing two GTPase domains and two helix-loop-helix Ca2+-binding domains called EF hands. Pioneering genetic studies in Drosophila first revealed a key function of Miro in regulating the axonal transport of mitochondria, during which Miro forms a multi-protein transport complex with Milton and Kinesin heavy chain (KHC to link trafficking mitochondria with the microtubule cytoskeleton. Recent studies showed that through binding to the EF hands of Miro and causing conformational changes of Miro and alteration of protein-protein interactions within the transport complex, Ca2+ can alter the engagement of mitochondria with the microtubule (MT/kinesin network, offering one mechanism to match mitochondrial distribution with neuronal activity. Despite the importance of the Miro/Milton/Kinesin complex in regulating mitochondrial transport in metazoans, not all components of the transport complex are conserved in lower organisms, and transport-independent functions of Miro are emerging. Here we review the diverse functions of the evolutionarily conserved Miro proteins that are relevant to the development, maintenance, and functioning of the nervous system and discuss the potential contribution of Miro dysfunction to the pathogenesis of diseases of the nervous system.

  2. Targeting endoplasmic reticulum and/or mitochondrial Ca2+ fluxes as therapeutic strategy for HCV infection

    Science.gov (United States)

    Scrima, Rosella; Piccoli, Claudia; Moradpour, Darius; Capitanio, Nazzareno

    2018-03-01

    Chronic hepatitis C is characterized by metabolic disorders and by a microenvironment in the liver dominated by oxidative stress, inflammation and regeneration processes that can in the long term lead to liver cirrhosis and hepatocellular carcinoma. Several lines of evidence suggest that mitochondrial dysfunctions play a central role in these processes. However, how these dysfunctions are induced by the virus and whether they play a role in disease progression and neoplastic transformation remains to be determined. Most in vitro studies performed so far have shown that several of the hepatitis C virus (HCV) proteins also localize to mitochondria, but the consequences of these interactions on mitochondrial functions remain contradictory and need to be confirmed in the context of productively replicating virus and physiologically relevant in vitro and in vivo model systems. In the past decade we have been proposing a temporal sequence of events in the HCV-infected cell whereby the primary alteration is localized at the mitochondria-associated ER membranes and causes release of Ca2+ from the ER, followed by uptake into mitochondria. This ensues successive mitochondrial dysfunction leading to the generation of reactive oxygen and nitrogen species and a progressive metabolic adaptive response consisting in decreased oxidative phosphorylation and enhanced aerobic glycolysis and lipogenesis. Here we resume the major results provided by our group in the context of HCV-mediated alterations of the cellular inter-compartmental calcium flux homeostasis and present new evidence suggesting targeting of ER and/or mitochondrial calcium transporters as a novel therapeutic strategy.

  3. Targeting Endoplasmic Reticulum and/or Mitochondrial Ca2+ Fluxes as Therapeutic Strategy for HCV Infection.

    Science.gov (United States)

    Scrima, Rosella; Piccoli, Claudia; Moradpour, Darius; Capitanio, Nazzareno

    2018-01-01

    Chronic hepatitis C is characterized by metabolic disorders and by a microenvironment in the liver dominated by oxidative stress, inflammation and regeneration processes that can in the long term lead to liver cirrhosis and hepatocellular carcinoma. Several lines of evidence suggest that mitochondrial dysfunctions play a central role in these processes. However, how these dysfunctions are induced by the virus and whether they play a role in disease progression and neoplastic transformation remains to be determined. Most in vitro studies performed so far have shown that several of the hepatitis C virus (HCV) proteins also localize to mitochondria, but the consequences of these interactions on mitochondrial functions remain contradictory and need to be confirmed in the context of productively replicating virus and physiologically relevant in vitro and in vivo model systems. In the past decade we have been proposing a temporal sequence of events in the HCV-infected cell whereby the primary alteration is localized at the mitochondria-associated ER membranes and causes release of Ca 2+ from the ER, followed by uptake into mitochondria. This ensues successive mitochondrial dysfunction leading to the generation of reactive oxygen and nitrogen species and a progressive metabolic adaptive response consisting in decreased oxidative phosphorylation and enhanced aerobic glycolysis and lipogenesis. Here we resume the major results provided by our group in the context of HCV-mediated alterations of the cellular inter-compartmental calcium flux homeostasis and present new evidence suggesting targeting of ER and/or mitochondrial calcium transporters as a novel therapeutic strategy.

  4. Discovery of a new mitochondria permeability transition pore (mPTP) inhibitor based on gallic acid.

    Science.gov (United States)

    Teixeira, José; Oliveira, Catarina; Cagide, Fernando; Amorim, Ricardo; Garrido, Jorge; Borges, Fernanda; Oliveira, Paulo J

    2018-12-01

    Pharmacological interventions targeting mitochondria present several barriers for a complete efficacy. Therefore, a new mitochondriotropic antioxidant (AntiOxBEN 3 ) based on the dietary antioxidant gallic acid was developed. AntiOxBEN 3 accumulated several thousand-fold inside isolated rat liver mitochondria, without causing disruption of the oxidative phosphorylation apparatus, as seen by the unchanged respiratory control ratio, phosphorylation efficiency, and transmembrane electric potential. AntiOxBEN 3 showed also limited toxicity on human hepatocarcinoma cells. Moreover, AntiOxBEN 3 presented robust iron-chelation and antioxidant properties in both isolated liver mitochondria and cultured rat and human cell lines. Along with its low toxicity profile and high antioxidant activity, AntiOxBEN 3 strongly inhibited the calcium-dependent mitochondrial permeability transition pore (mPTP) opening. From our data, AntiOxBEN 3 can be considered as a lead compound for the development of a new class of mPTP inhibitors and be used as mPTP de-sensitiser for basic research or clinical applications or emerge as a therapeutic application in mitochondria dysfunction-related disorders.

  5. Acrolein-induced cell death in PC12 cells: role of mitochondria-mediated oxidative stress.

    Science.gov (United States)

    Luo, Jian; Robinson, J Paul; Shi, Riyi

    2005-12-01

    Oxidative stress has been implicated in acrolein cytotoxicity in various cell types, including mammalian spinal cord tissue. In this study we report that acrolein also decreases PC12 cell viability in a reactive oxygen species (ROS)-dependent manner. Specifically, acrolein-induced cell death, mainly necrosis, is accompanied by the accumulation of cellular ROS. Elevating ROS scavengers can alleviate acrolein-induced cell death. Furthermore, we show that exposure to acrolein leads to mitochondrial dysfunction, denoted by the loss of mitochondrial transmembrane potential, reduction of cellular oxygen consumption, and decrease of ATP level. This raises the possibility that the cellular accumulation of ROS could result from the increased production of ROS in the mitochondria of PC12 cells as a result of exposure to acrolein. The acrolein-induced significant decrease of ATP production in mitochondria may also explain why necrosis, not apoptosis, is the dominant type of cell death. In conclusion, our data suggest that one possible mechanism of acrolein-induced cell death could be through mitochondria as its initial target. The subsequent increase of ROS then inflicts cell death and further worsens mitochondria function. Such mechanism may play an important role in CNS trauma and neurodegenerative diseases.

  6. Sensing the Stress: A Role for the UPRmt and UPRam in the Quality Control of Mitochondria

    Directory of Open Access Journals (Sweden)

    Sylvie Callegari

    2018-03-01

    Full Text Available Mitochondria exist as compartmentalized units, surrounded by a selectively permeable double membrane. Within is contained the mitochondrial genome and protein synthesis machinery, required for the synthesis of OXPHOS components and ultimately, ATP production. Despite their physical barrier, mitochondria are tightly integrated into the cellular environment. A constant flow of information must be maintained to and from the mitochondria and the nucleus, to ensure mitochondria are amenable to cell metabolic requirements and also to feedback on their functional state. This review highlights the pathways by which mitochondrial stress is signaled to the nucleus, with a particular focus on the mitochondrial unfolded protein response (UPRmt and the unfolded protein response activated by the mistargeting of proteins (UPRam. Although these pathways were originally discovered to alleviate proteotoxic stress from the accumulation of mitochondrial-targeted proteins that are misfolded or unimported, we review recent findings indicating that the UPRmt can also sense defects in mitochondrial translation. We further discuss the regulation of OXPHOS assembly and speculate on a possible role for mitochondrial stress pathways in sensing OXPHOS biogenesis.

  7. Triage of oxidation-prone proteins by Sqstm1/p62 within the mitochondria

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Minjung [Department of Molecular Cell Biology, Sungkyunkwan University School of Medicine and Samsung Biomedical Research Institute, Suwon-Si, Kyonggi-Do (Korea, Republic of); Shin, Jaekyoon, E-mail: jkshin@med.skku.ac.kr [Department of Molecular Cell Biology, Sungkyunkwan University School of Medicine and Samsung Biomedical Research Institute, Suwon-Si, Kyonggi-Do (Korea, Republic of)

    2011-09-16

    Highlights: {yields} The mitochondrion contains its own protein quality control system. {yields} p62 localizes within the mitochondria and forms mega-dalton sized complexes. {yields} p62 interacts with oxidation-prone proteins and the proteins of quality control. {yields} In vitro delivery of p62 improves mitochondrial functions. {yields} p62 is implicated as a participant in mitochondrial protein quality control. -- Abstract: As the mitochondrion is vulnerable to oxidative stress, cells have evolved several strategies to maintain mitochondrial integrity, including mitochondrial protein quality control mechanisms and autophagic removal of damaged mitochondria. Involvement of an autophagy adaptor, Sqstm1/p62, in the latter process has been recently described. In the present study, we provide evidence that a portion of p62 directly localizes within the mitochondria and supports stable electron transport by forming heterogeneous protein complexes. Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF) of mitochondrial proteins co-purified with p62 revealed that p62 interacts with several oxidation-prone proteins, including a few components of the electron transport chain complexes, as well as multiple chaperone molecules and redox regulatory enzymes. Accordingly, p62-deficient mitochondria exhibited compromised electron transport, and the compromised function was partially restored by in vitro delivery of p62. These results suggest that p62 plays an additional role in maintaining mitochondrial integrity at the vicinity of target machineries through its function in relation to protein quality control.

  8. GABA transaminases from Saccharomyces cerevisiae and Arabidopsis thaliana complement function in cytosol and mitochondria.

    Science.gov (United States)

    Cao, Juxiang; Barbosa, Jose M; Singh, Narendra; Locy, Robert D

    2013-07-01

    GABA transaminase (GABA-T) catalyses the conversion of GABA to succinate semialdehyde (SSA) in the GABA shunt pathway. The GABA-T from Saccharomyces cerevisiae (ScGABA-TKG) is an α-ketoglutarate-dependent enzyme encoded by the UGA1 gene, while higher plant GABA-T is a pyruvate/glyoxylate-dependent enzyme encoded by POP2 in Arabidopsis thaliana (AtGABA-T). The GABA-T from A. thaliana is localized in mitochondria and mediated by an 18-amino acid N-terminal mitochondrial targeting peptide predicated by both web-based utilities TargetP 1.1 and PSORT. Yeast UGA1 appears to lack a mitochondrial targeting peptide and is localized in the cytosol. To verify this bioinformatic analysis and examine the significance of ScGABA-TKG and AtGABA-T compartmentation and substrate specificity on physiological function, expression vectors were constructed to modify both ScGABA-TKG and AtGABA-T, so that they express in yeast mitochondria and cytosol. Physiological function was evaluated by complementing yeast ScGABA-TKG deletion mutant Δuga1 with AtGABA-T or ScGABA-TKG targeted to the cytosol or mitochondria for the phenotypes of GABA growth defect, thermosensitivity and heat-induced production of reactive oxygen species (ROS). This study demonstrates that AtGABA-T is functionally interchangeable with ScGABA-TKG for GABA growth, thermotolerance and limiting production of ROS, regardless of location in mitochondria or cytosol of yeast cells, but AtGABA-T is about half as efficient in doing so as ScGABA-TKG. These results are consistent with the hypothesis that pyruvate/glyoxylate-limited production of NADPH mediates the effect of the GABA shunt in moderating heat stress in Saccharomyces. Copyright © 2013 John Wiley & Sons, Ltd.

  9. Hydroxylation of 25-hydroxyvitamin D3 by renal mitochondria from rats of different ages.

    Science.gov (United States)

    Ishida, M; Bulos, B; Takamoto, S; Sacktor, B

    1987-08-01

    The hydroxylation of 25-hydroxyvitamin D3 (25OHD3) in kidney mitochondria from female rats of different ages was studied. The specific activity of 1 alpha-hydroxylase was highest in mitochondria isolated from the 2-month-old rat (0.47 pmol/10 min X mg protein), falling gradually with age to 0.17, 0.10, 0.07, and 0.06 pmol/10 min X mg protein in 6-, 12-, 18-, and 24-month-old rats, respectively. The alteration in 1 alpha-hydroxylase activity with age was due to a change in the V'm of the system; the K'm for 25OHD3 was unchanged (3.9-4.0 microM). The specific activity of 24-hydroxylase was lowest in mitochondria isolated from the 2-month-old rat (8.2 pmol/10 min X mg protein), increasing to 37.8, 37.4, 38.2, and 55.7 pmol/10 min X mg protein in 6-, 12-, 18-, and 24-month-old rats, respectively. The alteration in 24-hydroxylase activity with age was due to a change in the V'm of the system; the K'm value for 25OHD3 was unchanged (1.1-1.2 microM). The age-dependent decrease in 1 alpha-hydroxylase and concomitant increase in 24-hydroxylase activities observed in mitochondria isolated from kidneys of 2-, 6-, 12-, 18-, and 24-month-old rats could not be attributed to changes in the bioenergetic properties, i.e. the respiratory chain, of the mitochondria. The relative mitochondrial content of the kidney, however, probably decreased with age. These findings support the view that the kidneys of aged rats produce less 1,25-dihydroxyvitamin D3 because of lower mitochondrial 1 alpha-hydroxylase specific activity and reduced number of mitochondria. This would be consistent with the lower levels of vitamin D hormone reported in the serum of senescent rats.

  10. Long-term inhibition of cyclophilin D results in intracellular translocation of calcein AM from mitochondria to lysosomes.

    Science.gov (United States)

    Shinohe, Daisuke; Kobayashi, Asuka; Gotoh, Marina; Tanaka, Kotaro; Ohta, Yoshihiro

    2017-01-01

    Cyclophilin D is a peptidyl-prolyl cis-trans isomerase localized in the mitochondrial matrix. Although its effects on mitochondrial characteristics have been well studied, its relation to the uptake of molecules by mitochondria remains unknown. Here, we demonstrated the effects of cyclophilin D on the intracellular translocation of calcein AM. Following addition of calcein AM to control cells or cells overexpressing wild-type cyclophilin D, calcein fluorescence was observed in mitochondria. However, long-term inhibition of cyclophilin D in these cells altered the localization of calcein fluorescence from mitochondria to lysosomes without changing mitochondrial esterase activity. In addition, depletion of glucose from the medium recovered calcein localization from lysosomes to mitochondria. This is the first demonstration of the effects of cyclophilin D on the intracellular translocation of molecules other than proteins and suggests that cyclophilin D may modify mitochondrial features by inducing the translocation of molecules to the mitochondria through the mechanism associated with cellular energy metabolism. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. Citrate and succinate uptake by potato mitochondria

    International Nuclear Information System (INIS)

    Jung, D.W.; Laties, G.G.

    1979-01-01

    Potato mitochondria, in the absence of respiration, have a very low capacity for uptake by exchange with endogenous anions, taking up only 2.4 nanomoles citrate and 2.0 nanomoles succinate per milligram protein. Maximum citrate uptake of over 17 nanomoles per milligram protein occurs in the presence of inorganic phosphate, a dicarboxylic acid, and an external energy source (NADH), conditions where net anion accumulation proceeds, mediated by the interlinking of the inorganic phosphate, dicarboxylate, and tricarboxylate carriers. Maximum succinate uptake in the absence of respiratory inhibitors requires only added inorganic phosphate. Compounds which inhibit respiration (antimycin), the exchange carriers (mersalyl and benzylmalonate), or the establishment of the membrane proton motive force (uncouplers) reduce substrate accumulation. A potent inhibitor of the citrate carrier in animal mitochondria, 1,2,3-benzenetricarboxylic acid, does not inhibit citrate uptake in potato mitochondria. Citrate uptake is reduced by concurrent ADP phosphorylation and this reduction is sensitive to oligomycin. The initiation of state 3 after a 3-minute substrate state results in a reduction of the steady-state of citrate uptake by approximately 50%. Accumulation of succinate initially is inhibited by increasing sucrose concentration in the reaction medium from 50 to 400 millimolar. Limited substrate uptake is one of the factors responsible for the often observed depressed initial state 3 respiration rates in many mitochondrial preparations. Since nonlimiting levels of substrate in the matrix cannot be attained by energy-independent exchange, a dependence on respiration for adequate uptake results. Substrate limitation therefore occurs in the matrix for the period of time needed for energy-dependent accumulation of nonlimiting levels

  12. BioMEMS for mitochondria medicine

    Science.gov (United States)

    Padmaraj, Divya

    A BioMEMS device to study cell-mitochondrial physiological functionalities was developed. The pathogenesis of many diseases including obesity, diabetes and heart failure as well as aging has been linked to functional defects of mitochondria. The synthesis of Adenosine Tri Phosphate (ATP) is determined by the electrical potential across the inner mitochondrial membrane and by the pH difference due to proton flux across it. Therefore, electrical characterization by E-fields with complementary chemical testing was used here. The BioMEMS device was fabricated as an SU-8 based microfluidic system with gold electrodes on SiO2/Si wafers for electromagnetic interrogation. Ion Sensitive Field Effect Transistors (ISFETs) were incorporated for proton studies important in the electron transport chain, together with monitoring Na+, K+ and Ca++ ions for ion channel studies. ISFETs are chemically sensitive Metal Oxide Semiconductor Field Effect Transistor (MOSFET) devices and their threshold voltage is directly proportional to the electrolytic H+ ion variation. These ISFETs (sensitivity ˜55 mV/pH for H+) were further realized as specific ion sensitive Chemical Field Effect Transistors (CHEMFETs) by depositing a specific ion sensitive membrane on the gate. Electrodes for dielectric spectroscopy studies of mitochondria were designed as 2- and 4-probe structures for optimized operation over a wide frequency range. In addition, to limit polarization effects, a 4-electrode set-up with unique meshed pickup electrodes (7.5x7.5 mum2 loops with 4 mum wires) was fabricated. Sensitivity of impedance spectroscopy to membrane potential changes was confirmed by studying the influence of uncouplers and glucose on mitochondria. An electrical model was developed for the mitochondrial sample, and its frequency response correlated with impedance spectroscopy experiments of sarcolemmal mitochondria. Using the mesh electrode structure, we obtained a reduction of 83.28% in impedance at 200 Hz. COMSOL

  13. Intra- and Intercellular Quality Control Mechanisms of Mitochondria

    Directory of Open Access Journals (Sweden)

    Yoshimitsu Kiriyama

    2017-12-01

    Full Text Available Mitochondria function to generate ATP and also play important roles in cellular homeostasis, signaling, apoptosis, autophagy, and metabolism. The loss of mitochondrial function results in cell death and various types of diseases. Therefore, quality control of mitochondria via intra- and intercellular pathways is crucial. Intracellular quality control consists of biogenesis, fusion and fission, and degradation of mitochondria in the cell, whereas intercellular quality control involves tunneling nanotubes and extracellular vesicles. In this review, we outline the current knowledge on the intra- and intercellular quality control mechanisms of mitochondria.

  14. Caracterização da mitocôndria isolada de fígado de tilápia-do-nilo (Oreochromis niloticus e alterações da bioenergética mitocondrial causadas pela exposição herbicida oxifluorfena Characterization of liver mitochondria from Nile tilapia (Oreochromis niloticus and mitochondrial bioenergetics alterations caused by exposure to oxyfluorfen herbicide

    Directory of Open Access Journals (Sweden)

    F.P. Peixoto

    2009-04-01

    Full Text Available Descreve-se um método de isolamento de mitocôndrias acopladas de tilápia-do-nilo Oreochromis niloticus, isoladas de células hepáticas de peixes adultos. As mitocôndrias estavam metabolicamente ativas, sendo capazes de realizarem fosforilação oxidativa, de acordo com os valores do quociente de controle respiratório. Os valores de controle respiratório obtidos com malato/piruvato (complexo I e com succinato (complexo II foram de 5,8±0,8 e 3,38±0,4, respectivamente. O potencial de membrana exibiu o valor de 197±4mV, quer se utilizasse malato/piruvato ou succinato como substrato. O procedimento de isolamento de mitocôndrias de O. niloticus permite o estudo do efeito de xenobióticos na bioenergética mitocondrial, tendo sido avaliada a ação da oxifluorfena (0,6mgL-1 na bioenergética mitocondrial. Os resultados demonstram que o tratamento com oxifluorfena influencia a capacidade fosforilativa dos peixes, interferindo na sua carga energética, o que poderá levar à sua morte.A method for isolation of coupled mitochondria isolated from the liver of adult Nile tilapia Oreochromis niloticus is described for the first time. They were metabolically active, able to sustain oxidative phosphorylation, as shown by respiratory control ratio values, which were about 5.8±0.8 and 3.3±0.4 when respiring on malate/piruvate (complex I or succinate (complex II, respectively, as substrate. Membrane potential exhibited a value of approximately 197±4mV for malate/piruvate or succinate. The procedure now described for the isolation of O. niloticus mitochondria is an important new tool, allowing the study about the effect of xenobiotics on mitochondrial bioenergetic, being evaluated the effect of oxyfluorfen (0.6mgL-1 in the liver mitocondrial bioenergetic. These results showed that phosphorylation was significantly affected by oxyfluorfen which contributed to the decrease on the liver cell energy charge and consequently led to the fish dead.

  15. Antibiotic-Induced Changes to the Host Metabolic Environment Inhibit Drug Efficacy and Alter Immune Function

    DEFF Research Database (Denmark)

    Yang, Jason H.; Bhargava, Prerna; McCloskey, Douglas

    2017-01-01

    Bactericidal antibiotics alter microbial metabolism as part of their lethality and can damage mitochondria in mammalian cells. In addition, antibiotic susceptibility is sensitive to extracellular metabolites, but it remains unknown whether metabolites present at an infection site can affect eithe...

  16. The energy blockers 3-bromopyruvate and lonidamine: effects on bioenergetics of brain mitochondria.

    Science.gov (United States)

    Macchioni, Lara; Davidescu, Magdalena; Roberti, Rita; Corazzi, Lanfranco

    2014-10-01

    Tumor cells favor abnormal energy production via aerobic glycolysis and show resistance to apoptosis, suggesting the involvement of mitochondrial dysfunction. The differences between normal and cancer cells in their energy metabolism provide a biochemical basis for developing new therapeutic strategies. The energy blocker 3-bromopyruvate (3BP) can eradicate liver cancer in animals without associated toxicity, and is a potent anticancer towards glioblastoma cells. Since mitochondria are 3BP targets, in this work the effects of 3BP on the bioenergetics of normal rat brain mitochondria were investigated in vitro, in comparison with the anticancer agent lonidamine (LND). Whereas LND impaired oxygen consumption dependent on any complex of the respiratory chain, 3BP was inhibitory to malate/pyruvate and succinate (Complexes I and II), but preserved respiration from glycerol-3-phosphate and ascorbate (Complex IV). Accordingly, although electron flow along the respiratory chain and ATP levels were decreased by 3BP in malate/pyruvate- and succinate-fed mitochondria, they were not significantly influenced from glycerol-3-phosphate- or ascorbate-fed mitochondria. LND produced a decrease in electron flow from all substrates tested. No ROS were produced from any substrate, with the exception of 3BP-induced H(2)O(2) release from succinate, which suggests an antimycin-like action of 3BP as an inhibitor of Complex III. We can conclude that 3BP does not abolish completely respiration and ATP synthesis in brain mitochondria, and has a limited effect on ROS production, confirming that this drug may have limited harmful effects on normal cells.

  17. The Rise of Mitochondria in Medicine

    Science.gov (United States)

    Picard, Martin; Wallace, Douglas C; Burelle, Yan

    2016-01-01

    Once considered exclusively the cell's powerhouse, mitochondria are now recognized to perform multiple essential cellular functions beyond energy production, impacting most areas of cell biology and medicine. Since the emergence of molecular biology and the discovery of pathogenic mitochondrial DNA defects in the 1980's, research advances have revealed a number of common human diseases which share an underlying pathogenesis involving mitochondrial dysfunction. Mitochondria undergo function-defining dynamic shape changes, communicate with each other, regulate gene expression within the nucleus, modulate synaptic transmission within the brain, release molecules that contribute to oncogenic transformation and trigger inflammatory responses systemically, and influence the regulation of complex physiological systems. Novel “mitopathogenic” mechanisms are thus being uncovered across a number of medical disciplines including genetics, oncology, neurology, immunology, and critical care medicine. Increasing knowledge of the bioenergetic aspects of human disease has provided new opportunities for diagnosis, therapy, prevention, and in connecting various domains of medicine. In this article, we overview specific aspects of mitochondrial biology that have contributed to – and likely will continue to enhance the progress of modern medicine. PMID:27423788

  18. Non-target effects of a glyphosate-based herbicide on Common toad larvae (Bufo bufo, Amphibia) and associated algae are altered by temperature.

    Science.gov (United States)

    Baier, Fabian; Gruber, Edith; Hein, Thomas; Bondar-Kunze, Elisabeth; Ivanković, Marina; Mentler, Axel; Brühl, Carsten A; Spangl, Bernhard; Zaller, Johann G

    2016-01-01

    Glyphosate-based herbicides are the most widely used pesticides in agriculture, horticulture, municipalities and private gardens that can potentially contaminate nearby water bodies inhabited by amphibians and algae. Moreover, the development and diversity of these aquatic organisms could also be affected by human-induced climate change that might lead to more periods with extreme temperatures. However, to what extent non-target effects of these herbicides on amphibians or algae are altered by varying temperature is not well known. We studied effects of five concentrations of the glyphosate-based herbicide formulation Roundup PowerFlex (0, 1.5, 3, 4 mg acid equivalent glyphosate L -1 as a one time addition and a pulse treatment of totally 4 mg a.e. glyphosate L -1 ) on larval development of Common toads ( Bufo bufo , L.; Amphibia: Anura) and associated algae communities under two temperature regimes (15 vs. 20 °C). Herbicide contamination reduced tail growth (-8%), induced the occurrence of tail deformations (i.e. lacerated or crooked tails) and reduced algae diversity (-6%). Higher water temperature increased tadpole growth (tail and body length (tl/bl) +66%, length-to-width ratio +4%) and decreased algae diversity (-21%). No clear relation between herbicide concentrations and tadpole growth or algae density or diversity was observed. Interactive effects of herbicides and temperature affected growth parameters, tail deformation and tadpole mortality indicating that the herbicide effects are temperature-dependent. Remarkably, herbicide-temperature interactions resulted in deformed tails in 34% of all herbicide treated tadpoles at 15 °C whereas no tail deformations were observed for the herbicide-free control at 15 °C or any tadpole at 20 °C; herbicide-induced mortality was higher at 15 °C but lower at 20 °C. These herbicide- and temperature-induced changes may have decided effects on ecological interactions in freshwater ecosystems. Although no clear dose

  19. Non-target effects of a glyphosate-based herbicide on Common toad larvae (Bufo bufo, Amphibia and associated algae are altered by temperature

    Directory of Open Access Journals (Sweden)

    Fabian Baier

    2016-11-01

    Full Text Available Background Glyphosate-based herbicides are the most widely used pesticides in agriculture, horticulture, municipalities and private gardens that can potentially contaminate nearby water bodies inhabited by amphibians and algae. Moreover, the development and diversity of these aquatic organisms could also be affected by human-induced climate change that might lead to more periods with extreme temperatures. However, to what extent non-target effects of these herbicides on amphibians or algae are altered by varying temperature is not well known. Methods We studied effects of five concentrations of the glyphosate-based herbicide formulation Roundup PowerFlex (0, 1.5, 3, 4 mg acid equivalent glyphosate L−1 as a one time addition and a pulse treatment of totally 4 mg a.e. glyphosate L−1 on larval development of Common toads (Bufo bufo, L.; Amphibia: Anura and associated algae communities under two temperature regimes (15 vs. 20 °C. Results Herbicide contamination reduced tail growth (−8%, induced the occurrence of tail deformations (i.e. lacerated or crooked tails and reduced algae diversity (−6%. Higher water temperature increased tadpole growth (tail and body length (tl/bl +66%, length-to-width ratio +4% and decreased algae diversity (−21%. No clear relation between herbicide concentrations and tadpole growth or algae density or diversity was observed. Interactive effects of herbicides and temperature affected growth parameters, tail deformation and tadpole mortality indicating that the herbicide effects are temperature-dependent. Remarkably, herbicide-temperature interactions resulted in deformed tails in 34% of all herbicide treated tadpoles at 15 °C whereas no tail deformations were observed for the herbicide-free control at 15 °C or any tadpole at 20 °C; herbicide-induced mortality was higher at 15 °C but lower at 20 °C. Discussion These herbicide- and temperature-induced changes may have decided effects on ecological

  20. Endurance training increases the efficiency of rat skeletal muscle mitochondria.

    Science.gov (United States)

    Zoladz, Jerzy A; Koziel, Agnieszka; Woyda-Ploszczyca, Andrzej; Celichowski, Jan; Jarmuszkiewicz, Wieslawa

    2016-10-01

    Endurance training enhances mitochondrial oxidative capacity, but its effect on mitochondria functioning is poorly understood. In the present study, the influence of an 8-week endurance training on the bioenergetic functioning of rat skeletal muscle mitochondria under different assay temperatures (25, 35, and 42 °C) was investigated. The study was performed on 24 adult 4-month-old male Wistar rats, which were randomly assigned to either a treadmill training group (n = 12) or a sedentary control group (n = 12). In skeletal muscles, endurance training stimulated mitochondrial biogenesis and oxidative capacity. In isolated mitochondria, endurance training increased the phosphorylation rate and elevated levels of coenzyme Q. Moreover, a decrease in mitochondrial uncoupling, including uncoupling protein-mediated proton leak, was observed after training, which could explain the increased reactive oxygen species production (in nonphosphorylating mitochondria) and enhanced oxidative phosphorylation efficiency. At all studied temperatures, endurance training significantly augmented H2O2 production (and coenzyme Q reduction level) in nonphosphorylating mitochondria and decreased H2O2 production (and coenzyme Q reduction level) in phosphorylating mitochondria. Endurance training magnified the hyperthermia-induced increase in oxidative capacity and attenuated the hyperthermia-induced decline in oxidative phosphorylation efficiency and reactive oxygen species formation of nonphosphorylating mitochondria via proton leak enhancement. Thus, endurance training induces both quantitative and qualitative changes in muscle mitochondria that are important for cell signaling as well as for maintaining muscle energy homeostasis, especially at high temperatures.

  1. Transport of N-acetylglutamate in rat-liver mitochondria

    NARCIS (Netherlands)

    Meijer, A. J.; van Woerkom, G. M.; Wanders, R. J.; Lof, C.

    1982-01-01

    The permeability properties of the rat-liver mitochondrial membrane for N-acetylglutamate, the activator of carbamoyl-phosphate synthetase (ammonia), were studied. 1. Transport of N-acetylglutamate into the mitochondria was only observed in partially or fully de-energized mitochondria and when the

  2. Functional characterization of mitochondria in neutrophils: a role restricted to apoptosis

    NARCIS (Netherlands)

    Maianski, N. A.; Geissler, J.; Srinivasula, S. M.; Alnemri, E. S.; Roos, D.; Kuijpers, T. W.

    2004-01-01

    Mitochondria are known to combine life-supporting functions with participation in apoptosis by controlling caspase activity. Here, we report that in human blood neutrophils the mitochondria are different, because they preserve mainly death-mediating abilities. Neutrophil mitochondria hardly

  3. MITO-Porter: A liposome-based carrier system for delivery of macromolecules into mitochondria via membrane fusion.

    Science.gov (United States)

    Yamada, Yuma; Akita, Hidetaka; Kamiya, Hiroyuki; Kogure, Kentaro; Yamamoto, Takenori; Shinohara, Yasuo; Yamashita, Kikuji; Kobayashi, Hideo; Kikuchi, Hiroshi; Harashima, Hideyoshi

    2008-02-01

    Mitochondria are the principal producers of energy in higher cells. Mitochondrial dysfunction is implicated in a variety of human diseases, including cancer and neurodegenerative disorders. Effective medical therapies for such diseases will ultimately require targeted delivery of therapeutic proteins or nucleic acids to the mitochondria, which will be achieved through innovations in the nanotechnology of intracellular trafficking. Here we describe a liposome-based carrier that delivers its macromolecular cargo to the mitochondrial interior via membrane fusion. These liposome particles, which we call MITO-Porters, carry octaarginine surface modifications to stimulate their entry into cells as intact vesicles (via macropinocytosis). We identified lipid compositions for the MITO-Porter which promote both its fusion with the mitochondrial membrane and the release of its cargo to the intra-mitochondrial compartment in living cells. Thus, the MITO-Porter holds promise as an efficacious system for the delivery of both large and small therapeutic molecules into mitochondria.

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

    Science.gov (United States)

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

    2017-10-01

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

  5. Detection and characterisation of multi-drug resistance protein 1 (MRP-1) in human mitochondria.

    Science.gov (United States)

    Roundhill, E A; Burchill, S A

    2012-03-13

    Overexpression of plasma membrane multi-drug resistance protein 1 (MRP-1) can lead to multidrug resistance. In this study, we describe for the first time the expression of mitochondrial MRP-1 in untreated human normal and cancer cells and tissues. MRP-1 expression and subcellular localisation in normal and cancer cells and tissues was examined by differential centrifugation and western blotting, and immunofluorescence microscopy. Viable mitochondria were isolated and MRP-1 efflux activity measured using the calcein-AM functional assay. MRP-1 expression was increased using retroviral infection and specific overexpression confirmed by RNA array. Cell viability was determined by trypan blue exclusion and annexin V-propidium iodide labelling of cells. MRP-1 was detected in the mitochondria of cancer and normal cells and tissues. The efflux activity of mitochondrial MRP-1 was more efficient (55-64%) than that of plasma membrane MRP-1 (11-22%; PMRP-1 expression resulted in a preferential increase in mitochondrial MRP-1, suggesting selective targeting to this organelle. Treatment with a non-lethal concentration of doxorubicin (0.85 nM, 8 h) increased mitochondrial and plasma membrane MRP-1, increasing resistance to MRP-1 substrates. For the first time, we have identified MRP-1 with efflux activity in human mitochondria. Mitochondrial MRP-1 may be an exciting new therapeutic target where historically MRP-1 inhibitor strategies have limited clinical success.

  6. Pifithrin-α provides neuroprotective effects at the level of mitochondria independently of p53 inhibition.

    Science.gov (United States)

    Neitemeier, Sandra; Ganjam, Goutham K; Diemert, Sebastian; Culmsee, Carsten

    2014-12-01

    Impaired mitochondrial integrity and function are key features of intrinsic death pathways in neuronal cells. Therefore, key regulators of intrinsic death pathways acting upstream of mitochondria are potential targets for therapeutic approaches of neuroprotection. The tumor suppressor p53 is a well-established regulator of cellular responses towards different kinds of lethal stress, including oxidative stress. Recent reports suggested that p53 may affect mitochondrial integrity and function through both, transcriptional activation of mitochondria-targeted pro-death proteins and direct effects at the mitochondrial membrane. In the present study, we compared the effects of pharmacological inhibition of p53 by pifithrin-α with those of selective p53 gene silencing by RNA interference. Using MTT assay and real-time cell impedance measurements we confirmed the protective effect of both strategies against glutamate-induced oxidative stress in immortalized mouse hippocampal HT-22 neurons. Further, we observed full restoration of mitochondrial membrane potential and inhibition of glutamate-induced mitochondrial fragmentation by pifithrin-α which was, in contrast, not achieved by p53 gene silencing. Downregulation of p53 by siRNA decreased p53 transcriptional activity and reduced expression levels of p21 mRNA, while pifithrin-α did not affect these endpoints. These results suggest a neuroprotective effect of pifithrin-α which occurred at the level of mitochondria and independently of p53 inhibition.

  7. Arsenate uncoupling of oxidative phosphorylation in isolated plant mitochondria

    Energy Technology Data Exchange (ETDEWEB)

    Wickes, W A; Wiskich, J T

    1976-01-01

    The uncoupling by arsenate of beetroot and cauliflower bud mitochondria showed the following characteristics: arsenate stimulation of respiration above the rate found with phosphate; inhibition of arsenate-stimulated respiration by phosphate; enhancement of arsenate-stimulated respiration by ADP; only partial prevention of this ADP-enhanced respiration by atractyloside; inhibition by oligomycin of the arsenate-stimulated respiration back to the phosphate rate; and the absence of any stimulatory effect of ADP in the presence of oligomycin. These results are qualitatively analogous to those reported for arsenate uncoupling in rat liver mitochondria. Arsenate stimulated malate oxidation, presumably by stimulating malate entry, in both beetroot and cauliflower bud mitochondria; however, high rates of oxidation, and presumably entry, were only sustained with arsenate in beetroot mitochondria. NADH was oxidized rapidly in cauliflower bud mitochondria in the presence of arsenate, showing that arsenate did not inhibit electron transfer processes.

  8. Berberine as a promising safe anti-cancer agent - is there a role for mitochondria?

    Science.gov (United States)

    Diogo, Catia V; Machado, Nuno G; Barbosa, Inês A; Serafim, Teresa L; Burgeiro, Ana; Oliveira, Paulo J

    2011-06-01

    Metabolic regulation is largely dependent on mitochondria, which play an important role in energy homeostasis. Imbalance between energy intake and expenditure leads to mitochondrial dysfunction, characterized by a reduced ratio of energy production (ATP production) to respiration. Due to the role of mitochondrial factors/events in several apoptotic pathways, the possibility of targeting that organelle in the tumor cell, leading to its elimination is very attractive, although the safety issue is problematic. Berberine, a benzyl-tetra isoquinoline alkaloid extracted from plants of the Berberidaceae family, has been extensively used for many centuries, especially in the traditional Chinese and Native American medicine. Several evidences suggest that berberine possesses several therapeutic uses, including anti-tumoral activity. The present review supplies evidence that berberine is a safe anti-cancer agent, exerting several effects on mitochondria, including inhibition of mitochondrial Complex I and interaction with the adenine nucleotide translocator which can explain several of the described effects on tumor cells.

  9. Biogenesis of mitochondrial carrier proteins: molecular mechanisms of import into mitochondria.

    Science.gov (United States)

    Ferramosca, Alessandra; Zara, Vincenzo

    2013-03-01

    Mitochondrial metabolite carriers are hydrophobic proteins which catalyze the flux of several charged or hydrophilic substrates across the inner membrane of mitochondria. These proteins, like most mitochondrial proteins, are nuclear encoded and after their synthesis in the cytosol are transported into the inner mitochondrial membrane. Most metabolite carriers, differently from other nuclear encoded mitochondrial proteins, are synthesized without a cleavable presequence and contain several, poorly characterized, internal targeting signals. However, an interesting aspect is the presence of a positively charged N-terminal presequence in a limited number of mitochondrial metabolite carriers. Over the last few years the molecular mechanisms of import of metabolite carrier proteins into mitochondria have been thoroughly investigated. This review summarizes the present knowledge and discusses recent advances on the import and sorting of mitochondrial metabolite carriers. Copyright © 2012 Elsevier B.V. All rights reserved.

  10. Nitric oxide and mitochondria in metabolic syndrome

    Science.gov (United States)

    Litvinova, Larisa; Atochin, Dmitriy N.; Fattakhov, Nikolai; Vasilenko, Mariia; Zatolokin, Pavel; Kirienkova, Elena

    2015-01-01

    Metabolic syndrome (MS) is a cluster of metabolic disorders that collectively increase the risk of cardiovascular disease. Nitric oxide (NO) plays a crucial role in the pathogeneses of MS components and is involved in different mitochondrial signaling pathways that control respiration and apoptosis. The present review summarizes the recent information regarding the interrelations of mitochondria and NO in MS. Changes in the activities of different NO synthase isoforms lead to the formation of metabolic disorders and therefore are highlighted here. Reduced endothelial NOS activity and NO bioavailability, as the main factors underlying the endothelial dysfunction that occurs in MS, are discussed in this review in relation to mitochondrial dysfunction. We also focus on potential therapeutic strategies involving NO signaling pathways that can be used to treat patients with metabolic disorders associated with mitochondrial dysfunction. The article may help researchers develop new approaches for the diagnosis, prevention and treatment of MS. PMID:25741283

  11. Mitochondria in cancer: not just innocent bystanders.

    Science.gov (United States)

    Frezza, Christian; Gottlieb, Eyal

    2009-02-01

    The first half of the 20th century produced substantial breakthroughs in bioenergetics and mitochondria research. During that time, Otto Warburg observed abnormally high glycolysis and lactate production in oxygenated cancer cells, leading him to suggest that defects in mitochondrial functions are at the heart of malignant cell transformation. Warburg's hypothesis profoundly influenced the present perception of cancer metabolism, positioning what is termed aerobic glycolysis in the mainstream of clinical oncology. While some of his ideas stood the test of time, they also frequently generated misconceptions regarding the biochemical mechanisms of cell transformation. This review examines experimental evidence which supports or refutes the Warburg effect and discusses the possible advantages conferred on cancer cells by 'metabolic transformation'.

  12. Apoptosis in Drosophila: which role for mitochondria?

    Science.gov (United States)

    Clavier, Amandine; Rincheval-Arnold, Aurore; Colin, Jessie; Mignotte, Bernard; Guénal, Isabelle

    2016-03-01

    It is now well established that the mitochondrion is a central regulator of mammalian cell apoptosis. However, the importance of this organelle in non-mammalian apoptosis has long been regarded as minor, mainly because of the absence of a crucial role for cytochrome c in caspase activation. Recent results indicate that the control of caspase activation and cell death in Drosophila occurs at the mitochondrial level. Numerous proteins, including RHG proteins and proteins of the Bcl-2 family that are key regulators of Drosophila apoptosis, constitutively or transiently localize in mitochondria. These proteins participate in the cell death process at different levels such as degradation of Diap1, a Drosophila IAP, production of mitochondrial reactive oxygen species or stimulation of the mitochondrial fission machinery. Here, we review these mitochondrial events that might have their counterpart in human.

  13. Mitochondria, cognitive impairment, and Alzheimer's disease.

    Science.gov (United States)

    Mancuso, M; Calsolaro, V; Orsucci, D; Carlesi, C; Choub, A; Piazza, S; Siciliano, G

    2009-07-06

    To date, the beta amyloid (Abeta) cascade hypothesis remains the main pathogenetic model of Alzheimer's disease (AD), but its role in the majority of sporadic AD cases is unclear. The "mitochondrial cascade hypothesis" could explain many of the biochemical, genetic, and pathological features of sporadic AD. Somatic mutations in mitochondrial DNA (mtDNA) could cause energy failure, increased oxidative stress, and accumulation of Abeta, which in a vicious cycle reinforce the mtDNA damage and the oxidative stress. Despite the evidence of mitochondrial dysfunction in AD, no causative mutations in the mtDNA have been detected so far. Indeed, results of studies on the role of mtDNA haplogroups in AD are controversial. In this review we discuss the role of the mitochondria, and especially of the mtDNA, in the cascade of events leading to neurodegeneration, dementia, and AD.

  14. Melatonin, mitochondria, and the metabolic syndrome.

    Science.gov (United States)

    Cardinali, Daniel P; Vigo, Daniel E

    2017-11-01

    A number of risk factors for cardiovascular disease including hyperinsulinemia, glucose intolerance, dyslipidemia, obesity, and elevated blood pressure are collectively known as metabolic syndrome (MS). Since mitochondrial activity is modulated by the availability of energy in cells, the disruption of key regulators of metabolism in MS not only affects the activity of mitochondria but also their dynamics and turnover. Therefore, a link of MS with mitochondrial dysfunction has been suspected since long. As a chronobiotic/cytoprotective agent, melatonin has a special place in prevention and treatment of MS. Melatonin levels are reduced in diseases associated with insulin resistance like MS. Melatonin improves sleep efficiency and has antioxidant and anti-inflammatory properties, partly for its role as a metabolic regulator and mitochondrial protector. We discuss in the present review the several cytoprotective melatonin actions that attenuate inflammatory responses in MS. The clinical data that support the potential therapeutical value of melatonin in human MS are reviewed.

  15. Ceramide-Induced Apoptosis in Renal Tubular Cells: A Role of Mitochondria and Sphingosine-1-Phoshate

    Science.gov (United States)

    Ueda, Norishi

    2015-01-01

    Ceramide is synthesized upon stimuli, and induces apoptosis in renal tubular cells (RTCs). Sphingosine-1 phosphate (S1P) functions as a survival factor. Thus, the balance of ceramide/S1P determines ceramide-induced apoptosis. Mitochondria play a key role for ceramide-induced apoptosis by altered mitochondrial outer membrane permeability (MOMP). Ceramide enhances oligomerization of pro-apoptotic Bcl-2 family proteins, ceramide channel, and reduces anti-apoptotic Bcl-2 proteins in the MOM. This process alters MOMP, resulting in generation of reactive oxygen species (ROS), cytochrome C release into the cytosol, caspase activation, and apoptosis. Ceramide regulates apoptosis through mitogen-activated protein kinases (MAPKs)-dependent and -independent pathways. Conversely, MAPKs alter ceramide generation by regulating the enzymes involving ceramide metabolism, affecting ceramide-induced apoptosis. Crosstalk between Bcl-2 family proteins, ROS, and many signaling pathways regulates ceramide-induced apoptosis. Growth factors rescue ceramide-induced apoptosis by regulating the enzymes involving ceramide metabolism, S1P, and signaling pathways including MAPKs. This article reviews evidence supporting a role of ceramide for apoptosis and discusses a role of mitochondria, including MOMP, Bcl-2 family proteins, ROS, and signaling pathways, and crosstalk between these factors in the regulation of ceramide-induced apoptosis of RTCs. A balancing role between ceramide and S1P and the strategy for preventing ceramide-induced apoptosis by growth factors are also discussed. PMID:25751724

  16. Arsenic induces apoptosis in mouse liver is mitochondria dependent and is abrogated by N-acetylcysteine

    International Nuclear Information System (INIS)

    Santra, Amal; Chowdhury, Abhijit; Ghatak, Subhadip; Biswas, Ayan; Dhali, Gopal Krishna

    2007-01-01

    Arsenicosis, caused by arsenic contamination of drinking water supplies, is a major public health problem in India and Bangladesh. Chronic liver disease, often with portal hypertension occurs in chronic arsenicosis, contributes to the morbidity and mortality. The early cellular events that initiate liver cell injury due to arsenicosis have not been studied. Our aim was to identify the possible mechanisms related to arsenic-induced liver injury in mice. Liver injury was induced in mice by arsenic treatment. The liver was used for mitochondrial oxidative stress, mitochondrial permeability transition (MPT). Evidence of apoptosis was sought by TUNEL test, caspase assay and histology. Pretreatment with N-acetyl-L-cysteine (NAC) was done to modulate hepatic GSH level. Arsenic treatment in mice caused liver injury associated with increased oxidative stress in liver mitochondria and alteration of MPT. Altered MPT facilitated cytochrome c release in the cytosol, activation of caspase 9 and caspase 3 activities and apoptotic cell death. Pretreatment of NAC to arsenic-treated mice abrogated all these alteration suggesting a glutathione (GSH)-dependent mechanism. Oxidative stress in mitochondria and inappropriate MPT are important in the pathogenesis of arsenic induced apoptotic liver cell injury. The phenomenon is GSH dependent and supplementation of NAC might have beneficial effects

  17. Transcripts of the NADH-dehydrogenase subunit 3 gene are differentially edited in Oenothera mitochondria.

    Science.gov (United States)

    Schuster, W; Wissinger, B; Unseld, M; Brennicke, A

    1990-01-01

    A number of cytosines are altered to be recognized as uridines in transcripts of the nad3 locus in mitochondria of the higher plant Oenothera. Such nucleotide modifications can be found at 16 different sites within the nad3 coding region. Most of these alterations in the mRNA sequence change codon identities to specify amino acids better conserved in evolution. Individual cDNA clones differ in their degree of editing at five nucleotide positions, three of which are silent, while two lead to codon alterations specifying different amino acids. None of the cDNA clones analysed is maximally edited at all possible sites, suggesting slow processing or lowered stringency of editing at these nucleotides. Differentially edited transcripts could be editing intermediates or could code for differing polypeptides. Two edited nucleotides in an open reading frame located upstream of nad3 change two amino acids in the deduced polypeptide. Part of the well-conserved ribosomal protein gene rps12 also encoded downstream of nad3 in other plants, is lost in Oenothera mitochondria by recombination events. The functional rps12 protein must be imported from the cytoplasm since the deleted sequences of this gene are not found in the Oenothera mitochondrial genome. The pseudogene sequence is not edited at any nucleotide position. Images Fig. 3. Fig. 4. Fig. 7. PMID:1688531

  18. Mitochondria and Energetic Depression in Cell Pathophysiology

    Directory of Open Access Journals (Sweden)

    Stephan Zierz

    2009-05-01

    Full Text Available Mitochondrial dysfunction is a hallmark of almost all diseases. Acquired or inherited mutations of the mitochondrial genome DNA may give rise to mitochondrial diseases. Another class of disorders, in which mitochondrial impairments are initiated by extramitochondrial factors, includes neurodegenerative diseases and syndromes resulting from typical pathological processes, such as hypoxia/ischemia, inflammation, intoxications, and carcinogenesis. Both classes of diseases lead to cellular energetic depression (CED, which is characterized by decreased cytosolic phosphorylation potential that suppresses the cell’s ability to do work and control the intracellular Ca2+ homeostasis and its redox state. If progressing, CED leads to cell death, whose type is linked to the functional status of the mitochondria. In the case of limited deterioration, when some amounts of ATP can still be generated due to oxidative phosphorylation (OXPHOS, mitochondria launch the apoptotic cell death program by release of cytochrome c. Following pronounced CED, cytoplasmic ATP levels fall below the thresholds required for processing the ATP-dependent apoptotic cascade and the cell dies from necrosis. Both types of death can be grouped together as a mitochondrial cell death (MCD. However, there exist multiple adaptive reactions aimed at protecting cells against CED. In this context, a metabolic shift characterized by suppression of OXPHOS combined with activation of aerobic glycolysis as the main pathway for ATP synthesis (Warburg effect is of central importance. Whereas this type of adaptation is sufficiently effective to avoid CED and to control the cellular redox state, thereby ensuring the cell survival, it also favors the avoidance of apoptotic cell death. This scenario may underlie uncontrolled cellular proliferation and growth, eventually resulting in carcinogenesis.

  19. Lack of FTSH4 Protease Affects Protein Carbonylation, Mitochondrial Morphology, and Phospholipid Content in Mitochondria of Arabidopsis: New Insights into a Complex Interplay.

    Science.gov (United States)

    Smakowska, Elwira; Skibior-Blaszczyk, Renata; Czarna, Malgorzata; Kolodziejczak, Marta; Kwasniak-Owczarek, Malgorzata; Parys, Katarzyna; Funk, Christiane; Janska, Hanna

    2016-08-01

    FTSH4 is one of the inner membrane-embedded ATP-dependent metalloproteases in mitochondria of Arabidopsis (Arabidopsis thaliana). In mutants impaired to express FTSH4, carbonylated proteins accumulated and leaf morphology was altered when grown under a short-day photoperiod, at 22°C, and a long-day photoperiod, at 30°C. To provide better insight into the function of FTSH4, we compared the mitochondrial proteomes and oxyproteomes of two ftsh4 mutants and wild-type plants grown under conditions inducing the phenotypic alterations. Numerous proteins from various submitochondrial compartments were observed to be carbonylated in the ftsh4 mutants, indicating a widespread oxidative stress. One of the reasons for the accumulation of carbonylated proteins in ftsh4 was the limited ATP-dependent proteolytic capacity of ftsh4 mitochondria, arising from insufficient ATP amount, probably as a result of an impaired oxidative phosphorylation (OXPHOS), especially complex V. In ftsh4, we further observed giant, spherical mitochondria coexisting among normal ones. Both effects, the increased number of abnormal mitochondria and the decreased stability/activity of the OXPHOS complexes, were probably caused by the lower amount of the mitochondrial membrane phospholipid cardiolipin. We postulate that the reduced cardiolipin content in ftsh4 mitochondria leads to perturbations within the OXPHOS complexes, generating more reactive oxygen species and less ATP, and to the deregulation of mitochondrial dynamics, causing in consequence the accumulation of oxidative damage. © 2016 American Society of Plant Biologists. All Rights Reserved.

  20. Tributyltin interacts with mitochondria and induces cytochrome c release.

    Science.gov (United States)

    Nishikimi, A; Kira, Y; Kasahara, E; Sato, E F; Kanno, T; Utsumi, K; Inoue, M

    2001-01-01

    Although triorganotins are potent inducers of apoptosis in various cell types, the critical targets of these compounds and the mechanisms by which they lead to cell death remain to be elucidated. There are two major pathways by which apoptotic cell death occurs: one is triggered by a cytokine mediator and the other is by a mitochondrion-dependent mechanism. To elucidate the mechanism of triorganotin-induced apoptosis, we studied the effect of tributyltin on mitochondrial function. We found that moderately low doses of tributyltin decrease mitochondrial membrane potential and induce cytochrome c release by a mechanism inhibited by cyclosporine A and bongkrekic acid. Tributyltin-induced cytochrome c release is also prevented by dithiols such as dithiothreitol and 2,3-dimercaptopropanol but not by monothiols such as GSH, N-acetyl-L-cysteine, L-cysteine and 2-mercaptoethanol. Further studies with phenylarsine oxide agarose revealed that tributyltin interacts with the adenine nucleotide translocator, a functional constituent of the mitochondrial permeability transition pore, which is selectively inhibited by dithiothreitol. These results suggest that, at low doses, tributyltin interacts selectively with critical thiol residues in the adenine nucleotide translocator and opens the permeability transition pore, thereby decreasing membrane potential and releasing cytochrome c from mitochondria, a series of events consistent with established mechanistic models of apoptosis. PMID:11368793

  1. Mature Erythrocytes of Iguana iguana (Squamata, Iguanidae Possess Functional Mitochondria.

    Directory of Open Access Journals (Sweden)

    Giuseppina Di Giacomo

    Full Text Available Electron microscopy analyses of Iguana iguana blood preparations revealed the presence of mitochondria within erythrocytes with well-structured cristae. Fluorescence microscopy analyses upon incubation with phalloidin-FITC, Hoechst 33342 and mitochondrial transmembrane potential (Δψm-sensitive probe MitoTracker Red indicated that mitochondria i widely occur in erythrocytes, ii are polarized, and iii seem to be preferentially confined at a "perinuclear" region, as confirmed by electron microscopy. The analysis of NADH-dependent oxygen consumption showed that red blood cells retain the capability to consume oxygen, thereby providing compelling evidence that mitochondria of Iguana erythrocytes are functional and capable to perform oxidative phosphorylation.

  2. Mature Erythrocytes of Iguana iguana (Squamata, Iguanidae) Possess Functional Mitochondria.

    Science.gov (United States)

    Di Giacomo, Giuseppina; Campello, Silvia; Corrado, Mauro; Di Giambattista, Livia; Cirotti, Claudia; Filomeni, Giuseppe; Gentile, Gabriele

    2015-01-01

    Electron microscopy analyses of Iguana iguana blood preparations revealed the presence of mitochondria within erythrocytes with well-structured cristae. Fluorescence microscopy analyses upon incubation with phalloidin-FITC, Hoechst 33342 and mitochondrial transmembrane potential (Δψm)-sensitive probe MitoTracker Red indicated that mitochondria i) widely occur in erythrocytes, ii) are polarized, and iii) seem to be preferentially confined at a "perinuclear" region, as confirmed by electron microscopy. The analysis of NADH-dependent oxygen consumption showed that red blood cells retain the capability to consume oxygen, thereby providing compelling evidence that mitochondria of Iguana erythrocytes are functional and capable to perform oxidative phosphorylation.

  3. Protein oxidation in plant mitochondria as a stress indicator

    DEFF Research Database (Denmark)

    Møller, I.M.; Kristensen, B.K.

    2004-01-01

    oxidation of cysteine and methionine side chains is an important mechanism for regulating enzyme activity. Mitochondria from both mammalian and plant tissues contain a number of oxidised proteins, but the relative abundance of these post-translationally modified forms is as yet unknown......, as are the consequences of the modification for the properties and turnover time of the proteins. Specific proteins appear to be particularly vulnerable to oxidative carbonylation in the matrix of plant mitochondria; these include several enzymes of the Krebs cycle, glycine decarboxylase, superoxide dismutase and heat...... shock proteins. Plant mitochondria contain a number of different proteases, but their role in removing oxidatively damaged proteins is, as yet, unclear....

  4. Pathology of mitochondria in MELAS syndrome: an ultrastructural study.

    Science.gov (United States)

    Felczak, Paulina; Lewandowska, Eliza; Stępniak, Iwona; Ołdak, Monika; Pollak, Agnieszka; Lechowicz, Urszula; Pasennik, Elżbieta; Stępień, Tomasz; Wierzba-Bobrowicz, Teresa

    Ultrastructural changes in skeletal muscle biopsy in a 24-year-old female patient with clinically suspected mitochondrial encephalomyopathy lactic acidosis and stroke-like episodes (MELAS) syndrome are presented. We observed proliferation and/or pleomorphism of mitochondria in skeletal muscle and smooth muscle cells of arterioles, as well as in pericytes of capillaries. Paracrystalline inclusions were found only in damaged mitochondria of skeletal muscle. Genetic testing revealed a point mutation in A3243G tRNALeu(UUR) typical for MELAS syndrome. We conclude that differentiated pathological changes of mitochondria in the studied types of cells may be associated with the different energy requirements of these cells.

  5. PHO-ERK1/2 interaction with mitochondria regulates the permeability transition pore in cardioprotective signaling.

    Science.gov (United States)

    Hernández-Reséndiz, Sauri; Zazueta, Cecilia

    2014-07-11

    The molecular mechanism(s) by which extracellular signal-regulated kinase 1/2 (ERK1/2) and other kinases communicate with downstream targets have not been fully determined. Multiprotein signaling complexes undergoing spatiotemporal redistribution may enhance their interaction with effector proteins promoting cardioprotective response. Particularly, it has been proposed that some active kinases in association with caveolae may converge into mitochondria. Therefore, in this study we investigate if PHO-ERK1/2 interaction with mitochondria may provide a mechanistic link in the regulation of these organelles in cardioprotective signaling. Using a model of dilated cardiomyopathy followed by ischemia-reperfusion injury, we determined ERK1/2 signaling at the level of mitochondria and evaluated its effect on the permeability transition pore. The most important finding of the present study is that, under cardioprotective conditions, a subpopulation of activated ERK1/2 was directed to the mitochondrial membranes through vesicular trafficking, concurring with increased phosphorylation of mitochondrial proteins and inhibition of the mitochondrial permeability transition pore opening. In addition, our results suggest that vesicles enriched with caveolin-3 could form structures that may drive ERK1/2, GSK3β and Akt to mitochondria. Signaling complexes including PHO-ERK, PHO-Akt, PHO-eNOS and caveolin-3 contribute to cardioprotection by directly targeting the mitochondrial proteome and regulating the opening of the permeability transition pore in this model. Copyright © 2013 Elsevier Inc. All rights reserved.

  6. Threading the Needle: Small-Molecule Targeting of a Xenobiotic Receptor to Ablate Escherichia coli Polysaccharide Capsule Expression Without Altering Antibiotic Resistance.

    Science.gov (United States)

    Arshad, Mehreen; Goller, Carlos C; Pilla, Danielle; Schoenen, Frank J; Seed, Patrick C

    2016-04-15

    Uropathogenic Escherichia coli (UPEC), a leading cause of urinary tract and invasive infections worldwide, is rapidly acquiring multidrug resistance, hastening the need for selective new anti-infective agents. Here we demonstrate the molecular target of DU011, our previously discovered potent, nontoxic, small-molecule inhibitor of UPEC polysaccharide capsule biogenesis and virulence. Real-time polymerase chain reaction analysis and a target-overexpression drug-suppressor screen were used to localize the putative inhibitor target. A thermal shift assay quantified interactions between the target protein and the inhibitor, and a novel DNase protection assay measured chemical inhibition of protein-DNA interactions. Virulence of a regulatory target mutant was assessed in a murine sepsis model. MprA, a MarR family transcriptional repressor, was identified as the putative target of the DU011 inhibitor. Thermal shift measurements indicated the formation of a stable DU011-MprA complex, and DU011 abrogated MprA binding to its DNA promoter site. Knockout of mprA had effects similar to that of DU011 treatment of wild-type bacteria: a loss of encapsulation and complete attenuation in a murine sepsis model, without any negative change in antibiotic resistance. MprA regulates UPEC polysaccharide encapsulation, is essential for UPEC virulence, and can be targeted without inducing antibiotic resistance. © The Author 2015. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

  7. Tumor-Selective Cytotoxicity of Nitidine Results from Its Rapid Accumulation into Mitochondria

    Directory of Open Access Journals (Sweden)

    Hironori Iwasaki

    2017-01-01

    Full Text Available We identified a nitidine- (NTD- accumulating organelle and evaluated the net cytotoxicity of accumulated NTD. To evaluate tumor cell selectivity of the drug, we evaluated its selective cytotoxicity against 39 human cancer cell lines (JFCR39 panel, and the profile was compared with those of known anticancer drugs. Organelle specificity of NTD was visualized using organelle-targeted fluorescent proteins. Real-time analysis of cell growth, proliferation, and cytotoxicity was performed using the xCELLigence system. Selectivity of NTD in the JFCR39 panel was evaluated. Mitochondria-specific accumulation of NTD was observed. Real-time cytotoxicity analysis suggested that the mechanism of NTD-induced cell death is independent of the cell cycle. Short-term treatment indicated that this cytotoxicity only resulted from the accumulation of NTD into the mitochondria. The results from the JFCR39 panel indicated that NTD-mediated cytotoxicity resulted from unique mechanisms compared with those of other known anticancer drugs. These results suggested that the cytotoxicity of NTD is only induced by its accumulation in mitochondria. The drug triggered mitochondrial dysfunction in less than 2 h. Similarity analysis of the selectivity of NTD in 39 tumor cell lines strongly supported the unique tumor cell specificity of NTD. Thus, these features indicate that NTD may be a promising antitumor drug for new combination chemotherapies.

  8. Neurosteroids: oligodendrocyte mitochondria convert cholesterol to pregnenolone

    International Nuclear Information System (INIS)

    Hu, Z.Y.; Bourreau, E.; Jung-Testas, I.; Robel, P.; Baulieu, E.E.

    1987-01-01

    Oligodendrocyte mitochondria from 21-day-old Sprague-Dawley male rats were incubated with 100 nM [ 3 H]cholesterol. It yielded [ 3 H]pregnenolone at a rate of 2.5 +/- 0.7 and 5-[ 3 H]pregnene-3β,20α-diol at a rate of 2.5 +/- 1.1 pmol per mg of protein per hr. Cultures of glial cells from 19- to 21-day-old fetuses (a mixed population of astrocytes and oligodendrocytes) were incubated for 24 hr with [ 3 H]mevalonolactone. [ 3 H]Cholesterol, [ 3 H]pregnenolone, and 5-[ 3 H]pregnene-3β,20α-diol were characterized in cellular extracts. The formation of the 3 H-labeled steroids was increased by dibutyryl cAMP (0.2 mM) added to the culture medium. The active cholesterol side-chain cleavage mechanism, recently suggested immunohistochemically and already observed in cultures of C6 glioma cells, reinforces the concept of neurosteroids applied to Δ 5 -3β-hydroxysteroids previously isolated from brain

  9. Redox conditions and protein oxidation in plant mitochondria

    DEFF Research Database (Denmark)

    Møller, Ian Max; Kasimova, Marina R.; Krab, Klaas

    2005-01-01

    Redox conditions and protein oxidation in plant mitochondria NAD(P)H has a central position in respiratory metabolism. It is produced by a large number of enzymes, e.g. the Krebs cycle dehydrogenases, in the mitochondrial matrix and is oxidised by, amongst others, the respiratory chain. Most...... of this NAD(P)H appears to be bound to proteins, in fact free NAD(P)H – an important parameter in metabolic regulation - has never been observed in mitochondria. We have estimated free and bound NAD(P)H in isolated plant mitochondria under different metabolic conditions. The fluorescence spectra of free...... and bound NADH was determined and used to deconvolute fluorescence spectra of actively respiring mitochondria. Most of the mitochondrial NADH is bound in states 2 and 4. The amount of free NADH is lower but relatively constant even increasing a little in state 3 where it is about equal to bound NADH...

  10. The destiny of Ca(2+) released by mitochondria.

    Science.gov (United States)

    Takeuchi, Ayako; Kim, Bongju; Matsuoka, Satoshi

    2015-01-01

    Mitochondrial Ca(2+) is known to regulate diverse cellular functions, for example energy production and cell death, by modulating mitochondrial dehydrogenases, inducing production of reactive oxygen species, and opening mitochondrial permeability transition pores. In addition to the action of Ca(2+) within mitochondria, Ca(2+) released from mitochondria is also important in a variety of cellular functions. In the last 5 years, the molecules responsible for mitochondrial Ca(2+) dynamics have been identified: a mitochondrial Ca(2+) uniporter (MCU), a mitochondrial Na(+)-Ca(2+) exchanger (NCLX), and a candidate for a mitochondrial H(+)-Ca(2+) exchanger (Letm1). In this review, we focus on the mitochondrial Ca(2+) release system, and discuss its physiological and pathophysiological significance. Accumulating evidence suggests that the mitochondrial Ca(2+) release system is not only crucial in maintaining mitochondrial Ca(2+) homeostasis but also participates in the Ca(2+) crosstalk between mitochondria and the plasma membrane and between mitochondria and the endoplasmic/sarcoplasmic reticulum.

  11. Characterization of DNA-binding proteins from pea mitochondria

    DEFF Research Database (Denmark)

    Hatzack, F.A.; Dombrowski, S.; Brennicke, A.

    1998-01-01

    We studied transcription initiation in the mitochondria of higher plants, with particular respect to promoter structures. Conserved elements of these promoters have been successfully identified by in vitro transcription systems in different species, whereas the involved protein components are still...

  12. SEGMENTATION OF MITOCHONDRIA IN ELECTRON MICROSCOPY IMAGES USING ALGEBRAIC CURVES.

    Science.gov (United States)

    Seyedhosseini, Mojtaba; Ellisman, Mark H; Tasdizen, Tolga

    2013-01-01

    High-resolution microscopy techniques have been used to generate large volumes of data with enough details for understanding the complex structure of the nervous system. However, automatic techniques are required to segment cells and intracellular structures in these multi-terabyte datasets and make anatomical analysis possible on a large scale. We propose a fully automated method that exploits both shape information and regional statistics to segment irregularly shaped intracellular structures such as mitochondria in electron microscopy (EM) images. The main idea is to use algebraic curves to extract shape features together with texture features from image patches. Then, these powerful features are used to learn a random forest classifier, which can predict mitochondria locations precisely. Finally, the algebraic curves together with regional information are used to segment the mitochondria at the predicted locations. We demonstrate that our method outperforms the state-of-the-art algorithms in segmentation of mitochondria in EM images.

  13. Interorganelle Communication between Mitochondria and the Endolysosomal System

    Directory of Open Access Journals (Sweden)

    Gonzalo Soto-Heredero

    2017-11-01

    Full Text Available The function of mitochondria and lysosomes has classically been studied separately. However, evidence has now emerged of intense crosstalk between these two organelles, such that the activity or stress status of one organelle may affect the other. Direct physical contacts between mitochondria and the endolysosomal compartment have been reported as a rapid means of interorganelle communication, mediating lipid or other metabolite exchange. Moreover, mitochondrial derived vesicles can traffic obsolete mitochondrial proteins into the endolysosomal system for their degradation or secretion to the extracellular milieu as exosomes, representing an additional mitochondrial quality control mechanism that connects mitochondria and lysosomes independently of autophagosome formation. Here, we present what is currently known about the functional and physical communication between mitochondria and lysosomes or lysosome-related organelles, and their role in sustaining cellular homeostasis.

  14. WHITE PANICLE3, a Novel Nucleus-Encoded Mitochondrial Protein, Is Essential for Proper Development and Maintenance of Chloroplasts and Mitochondria in Rice

    Directory of Open Access Journals (Sweden)

    Hongchang Li

    2018-06-01

    Full Text Available Mitochondria and chloroplasts are interacting organelles that play important roles in plant development. In addition to a small number proteins encoded by their own genomes, the majority of mitochondrial and chloroplast proteins are encoded in the cell nucleus and imported into the organelle. As a consequence, coordination between mitochondria, chloroplasts, and the nucleus is of crucial importance to plant cells. Variegated mutants are chloroplast-defective mutants and are considered to be ideal models for studying the intercommunication between these organelles. Here, we report the isolation of WHITE PANICLE3 (WP3, a nuclear gene involved in variegation, from a naturally occurring white panicle rice mutant. Disrupted expression of WP3 in the mutant leads to severe developmental defects in both chloroplasts and mitochondria, and consequently causes the appearance of white-striped leaves and white panicles in the mutant plants. Further investigation showed that WP3 encodes a protein most likely targeted to mitochondria and is specifically expressed in rice panicles. Interestingly, we demonstrate that the recessive white-panicle phenotype in the wp3 mutant is inherited in a typical Mendelian manner, while the white-striped leaf phenotype in wp3 is maternally inherited. Our data collectively suggest that the nucleus-encoded mitochondrial protein, WP3, plays an essential role in the regulation of chloroplast development in rice panicles by maintaining functional mitochondria. Therefore, the wp3 mutant is an excellent model in which to explore the communication between the nucleus, mitochondria, and chloroplasts in plant cells.

  15. Optic neuropathies--importance of spatial distribution of mitochondria as well as function.

    Science.gov (United States)

    Yu Wai Man, C Y; Chinnery, P F; Griffiths, P G

    2005-01-01

    death. Evidence for this comes from studies of cultured cells with the dominant optic atrophy mutation in which mitochondrial distribution is altered and from some forms of hereditary spastic paraparesis which are associated with optic atrophy. The responsible mutations do not affect ATP production until late in the disease but do affect mitochondrial arrangement, again showing that mitochondrial distribution as well as energy production by individual mitochondria may be important in the pathogenesis of ganglion cell death. Greater understanding of the factors localising mitochondria within the ganglion cell axon in particular the interaction with cytoskeleton is required to formulate new treatments. Boosting energy production alone may not be an effective treatment.

  16. Mitochondria Superoxide Anion Production Contributes to Geranylgeraniol-Induced Death in Leishmania amazonensis

    Directory of Open Access Journals (Sweden)

    Milene Valéria Lopes

    2012-01-01

    Full Text Available Here we demonstrate the activity of geranylgeraniol, the major bioactive constituent from seeds of Bixa orellana, against Leishmania amazonensis. Geranylgeraniol was identified through 1H and 13C nuclear magnetic resonance imaging and DEPT. The compound inhibited the promastigote and intracellular amastigote forms, with IC50 of 11±1.0 and 17.5±0.7 μg/mL, respectively. This compound was also more toxic to parasites than to macrophages and did not cause lysis in human blood cells. Morphological and ultrastructural changes induced by geranylgeraniol were observed in the protozoan by electronic microscopy and included mainly mitochondria alterations and an abnormal chromatin condensation in the nucleus. These alterations were confirmed by Rh 123 and TUNEL assays. Additionally, geranylgeraniol induces an increase in superoxide anion production. Collectively, our in vitro studies indicate geranylgeraniol as a selective antileishmanial that appears to be mediated by apoptosis-like cell death.

  17. One size does not fit all: how the tobacco industry has altered cigarette design to target consumer groups with specific psychological and psychosocial needs.

    Science.gov (United States)

    Cook, Benjamin Lê; Wayne, Geoffrey Ferris; Keithly, Lois; Connolly, Gregory

    2003-11-01

    To identify whether the tobacco industry has targeted cigarette product design towards individuals with varying psychological/psychosocial needs. Internal industry documents were identified through searches of an online archival document research tool database using relevancy criteria of consumer segmentation and needs assessment. The industry segmented consumer markets based on psychological needs (stress relief, behavioral arousal, performance enhancement, obesity reduction) and psychosocial needs (social acceptance, personal image). Associations between these segments and smoking behaviors, brand and design preferences were used to create cigarette brands targeting individuals with these needs. Cigarette brands created to address the psychological/psychosocial needs of smokers may increase the likelihood of smoking initiation and addiction. Awareness of targeted product development will improve smoking cessation and prevention efforts.

  18. Influence of Pulsed Electric Fields and Mitochondria-Cytoskeleton Interactions on Cell Respiration.

    Science.gov (United States)

    Goswami, Ishan; Perry, Justin B; Allen, Mitchell E; Brown, David A; von Spakovsky, Michael R; Verbridge, Scott S

    2018-06-19

    Pulsed electric fields with microsecond pulse width (μsPEFs) are used clinically; namely, irreversible electroporation/Nanoknife is used for soft tissue tumor ablation. The μsPEF pulse parameters used in irreversible electroporation (0.5-1 kV/cm, 80-100 pulses, ∼100 μs each, 1 Hz frequency) may cause an internal field to develop within the cell because of the disruption of the outer cell membrane and subsequent penetration of the electric field. An internal field may disrupt voltage-sensitive mitochondria, although the research literature has been relatively unclear regarding whether such disruptions occur with μsPEFs. This investigation reports the influence of clinically used μsPEF parameters on mitochondrial respiration in live cells. Using a high-throughput Agilent Seahorse machine, it was observed that μsPEF exposure comprising 80 pulses with amplitudes of 600 or 700 V/cm did not alter mitochondrial respiration in 4T1 cells measured after overnight postexposure recovery. To record alterations in mitochondrial function immediately after μsPEF exposure, high-resolution respirometry was used to measure the electron transport chain state via responses to glutamate-malate and ADP and mitochondrial membrane potential via response to carbonyl cyanide-p-trifluoromethoxyphenylhydrazone. In addition to measuring immediate mitochondrial responses to μsPEF exposure, measurements were also made on cells permeabilized using digitonin and those with compromised cytoskeleton due to actin depolymerization via treatment with the drug latrunculin B. The former treatment was used as a control to tease out the effects of plasma membrane permeabilization, whereas the latter was used to investigate indirect effects on the mitochondria that may occur if μsPEFs impact the cytoskeleton on which the mitochondria are anchored. Based on the results, it was concluded that within the pulse parameters tested, μsPEFs alone do not hinder mitochondrial physiology but can be used

  19. Bax function in the absence of mitochondria in the primitive protozoan Giardia lamblia.

    Directory of Open Access Journals (Sweden)

    Adrian B Hehl

    Full Text Available Bax-induced permeabilization of the mitochondrial outer membrane and release of cytochrome c are key events in apoptosis. Although Bax can compromise mitochondria in primitive unicellular organisms that lack a classical apoptotic machinery, it is still unclear if Bax alone is sufficient for this, or whether additional mitochondrial components are required. The protozoan parasite Giardia lamblia is one of the earliest branching eukaryotes and harbors highly degenerated mitochondrial remnant organelles (mitosomes that lack a genome. Here we tested whether human Bax expressed in Giardia can be used to ablate mitosomes. We demonstrate that these organelles are neither targeted, nor compromised, by Bax. However, specialized compartments of the regulated secretory pathway are completely ablated by Bax. As a consequence, maturing cyst wall proteins that are sorted into these organelles are released into the cytoplasm, causing a developmental arrest and cell death. Interestingly, this ectopic cargo release is dependent on the carboxy-terminal 22 amino acids of Bax, and can be prevented by the Bax-inhibiting peptide Ku70. A C-terminally truncated Bax variant still localizes to secretory organelles, but is unable to permeabilize these membranes, uncoupling membrane targeting and cargo release. Even though mitosomes are too diverged to be recognized by Bax, off-target membrane permeabilization appears to be conserved and leads to cell death completely independently of mitochondria.

  20. Host cell subversion by Toxoplasma GRA16, an exported dense granule protein that targets the host cell nucleus and alters gene expression.

    Science.gov (United States)

    Bougdour, Alexandre; Durandau, Eric; Brenier-Pinchart, Marie-Pierre; Ortet, Philippe; Barakat, Mohamed; Kieffer, Sylvie; Curt-Varesano, Aurélie; Curt-Bertini, Rose-Laurence; Bastien, Olivier; Coute, Yohann; Pelloux, Hervé; Hakimi, Mohamed-Ali

    2013-04-17

    After invading host cells, Toxoplasma gondii multiplies within a parasitophorous vacuole (PV) that is maintained by parasite proteins secreted from organelles called dense granules. Most dense granule proteins remain within the PV, and few are known to access the host cell cytosol. We identify GRA16 as a dense granule protein that is exported through the PV membrane and reaches the host cell nucleus, where it positively modulates genes involved in cell-cycle progression and the p53 tumor suppressor pathway. GRA16 binds two host enzymes, the deubiquitinase HAUSP and PP2A phosphatase, which exert several functions, including regulation of p53 and the cell cycle. GRA16 alters p53 levels in a HAUSP-dependent manner and induces nuclear translocation of the PP2A holoenzyme. Additionally, certain GRA16-deficient strains exhibit attenuated virulence, indicating the importance of these host alterations in pathogenesis. Therefore, GRA16 represents a potentially emerging subfamily of exported dense granule proteins that modulate host function. Copyright © 2013 Elsevier Inc. All rights reserved.

  1. Targeted disruption of the mouse Csrp2 gene encoding the cysteine- and glycine-rich LIM domain protein CRP2 result in subtle alteration of cardiac ultrastructure

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    Stoll Doris

    2008-08-01

    Full Text Available Abstract Background The cysteine and glycine rich protein 2 (CRP2 encoded by the Csrp2 gene is a LIM domain protein expressed in the vascular system, particularly in smooth muscle cells. It exhibits a bimodal subcellular distribution, accumulating at actin-based filaments in the cytosol and in the nucleus. In order to analyze the function of CRP2 in vivo, we disrupted the Csrp2 gene in mice and analysed the resulting phenotype. Results A ~17.3 kbp fragment of the murine Csrp2 gene containing exon 3 through 6 was isolated. Using this construct we confirmed the recently determined chromosomal localization (Chromosome 10, best fit location between markers D10Mit203 proximal and D10Mit150 central. A gene disruption cassette was cloned into exon 4 and a mouse strain lacking functional Csrp2 was generated. Mice lacking CRP2 are viable and fertile and have no obvious deficits in reproduction and survival. However, detailed histological and electron microscopic studies reveal that CRP2-deficient mice have subtle alterations in their cardiac ultrastructure. In these mice, the cardiomyocytes display a slight increase in their thickness, indicating moderate hypertrophy at the cellular level. Although the expression of several intercalated disc-associated proteins such as β-catenin, N-RAP and connexin-43 were not affected in these mice, the distribution of respective proteins was changed within heart tissue. Conclusion We conclude that the lack of CRP2 is associated with alterations in cardiomyocyte thickness and hypertrophy.

  2. ER-mitochondria contacts control surface glycan expression and sensitivity to killer lymphocytes in glioma stem-like cells.

    Science.gov (United States)

    Bassoy, Esen Yonca; Kasahara, Atsuko; Chiusolo, Valentina; Jacquemin, Guillaume; Boydell, Emma; Zamorano, Sebastian; Riccadonna, Cristina; Pellegatta, Serena; Hulo, Nicolas; Dutoit, Valérie; Derouazi, Madiha; Dietrich, Pierre Yves; Walker, Paul R; Martinvalet, Denis

    2017-06-01

    Glioblastoma is a highly heterogeneous aggressive primary brain tumor, with the glioma stem-like cells (GSC) being more sensitive to cytotoxic lymphocyte-mediated killing than glioma differentiated cells (GDC). However, the mechanism behind this higher sensitivity is unclear. Here, we found that the mitochondrial morphology of GSCs modulates the ER-mitochondria contacts that regulate the surface expression of sialylated glycans and their recognition by cytotoxic T lymphocytes and natural killer cells. GSCs displayed diminished ER-mitochondria contacts compared to GDCs. Forced ER-mitochondria contacts in GSCs increased their cell surface expression of sialylated glycans and reduced their susceptibility to cytotoxic lymphocytes. Therefore, mitochondrial morphology and dynamism dictate the ER-mitochondria contacts in order to regulate the surface expression of certain glycans and thus play a role in GSC recognition and elimination by immune effector cells. Targeting the mitochondrial morphology, dynamism, and contacts with the ER could be an innovative strategy to deplete the cancer stem cell compartment to successfully treat glioblastoma. © 2017 The Authors.

  3. Can foreign proteins imported into yeast mitochondria interfere with PIM1p protease and/or chaperone function?

    Science.gov (United States)

    Saveliev, A S; Kovaleva, I E; Novikova, L A; Isaeva, L V; Luzikov, V N

    1999-03-15

    When studying the fate of mammalian apocytochrome P450scc (apo-P450scc) imported in small amounts into isolated yeast mitochondria, we found that it undergoes degradation, this process being retarded if recipient mitochondria are preloaded in vivo (to about 0.2% of total organelle protein) with a fusion protein composed of mammalian adrenodoxin reductase and adrenodoxin (AdR-Ad); in parallel we observed aggregation of apo-P450scc. These effects suggest some overload of Pim1p protease and/or mtHsp70 system by AdR-Ad, as both of them are involved in the degradation of apo-P450scc (see Savel'ev et al. J. Biol. Chem. 273, 20596-20602, 1998). However, under the same conditions AdR-Ad was not able to impede the import of proteins into mitochondria and the development of the mitochondrial respiratory machinery in yeast, the processes requiring the mtHsp70 system and Pim1p, respectively. These data imply that chaperones and Pim1p protease prefer their natural targets in mitochondria to imported foreign proteins. Copyright 1999 Academic Press.

  4. Toxicity of thallium on isolated rat liver mitochondria: the role of oxidative stress and MPT pore opening.

    Science.gov (United States)

    Eskandari, M R; Mashayekhi, Vida; Aslani, Majid; Hosseini, Mir-Jamal

    2015-02-01

    Thallium(I) is a highly toxic heavy metal; however, up to now, its mechanisms are poorly understood. The authors' previous studies showed that this compound could induce reactive oxygen species (ROS) formation, reduced glutathione (GSH) oxidation, membrane lipid peroxidation, and mitochondrial membrane potential (MMP) collapse in isolated rat hepatocyte. Because the liver is the storage site of thallium, it seems that the liver mitochondria are one of the important targets for hepatotoxicity. In this investigation, the effects of thallium on mitochondria were studied to investigate its mechanisms of toxicity. Mitochondria were isolated from rat liver and incubated with different concentrations of thallium (25-200 µM). Thallium(I)-treated mitochondria showed a marked elevation in oxidative stress parameters accompanied by MMP collapse when compared with the control group. These results showed that different concentrations of thallium (25-200 µM) induced a significant (P thallium(I)-induced liver toxicity is a result of the disruptive effect of this metal on the mitochondrial respiratory complexes (I, II, and IV), which are the obvious causes of metal-induced ROS formation and ATP depletion. The latter two events, in turn, trigger cell death signaling via opening of mitochondrial permeability transition pore and cytochrome c expulsion. © 2013 Wiley Periodicals, Inc.

  5. Evolved changes in the intracellular distribution and physiology of muscle mitochondria in high-altitude native deer mice.

    Science.gov (United States)

    Mahalingam, Sajeni; McClelland, Grant B; Scott, Graham R

    2017-07-15

    (but not intermyofibrillar) mitochondria, such that more mitochondria were situated near the cell membrane and adjacent to capillaries. Hypoxia acclimation had no significant effect on these population differences, but it did increase mitochondrial cristae surface densities of mitochondria in both populations. Hypoxia acclimation also altered the physiology of isolated mitochondria by affecting respiratory capacities and cytochrome c oxidase activities in population-specific manners. Chronic hypoxia decreased the release of reactive oxygen species by isolated mitochondria in both populations. There were subtle differences in O 2 kinetics between populations, with highlanders exhibiting increased mitochondrial O 2 affinity or catalytic efficiency in some conditions. Our results suggest that evolved changes in mitochondrial physiology in high-altitude natives are distinct from the effects of hypoxia acclimation, and probably provide a better indication of adaptive traits that improve performance and hypoxia resistance at high altitudes. © 2017 The Authors. The Journal of Physiology © 2017 The Physiological Society.

  6. The influence of dietary iodine and enviromental temperature on the activity of mitochondria in liver and kidney.

    Science.gov (United States)

    Chaiyabutr, N; Jakobsen, P E

    1978-08-01

    It was found that both effect of temperatures and diets influence metabolic changes in rabbits. In animals fed basal and PTU diets (propyl-thiouracil diets) at 34 degrees C for 4 weeks the metabolic response showed a marked reduction in feed intake and body weight, compared with animals fed at normal temperatures. In the animals fed the iodine diet, there was an increase in daily food consumption and weekly body weight gain at 34 degrees C. This indicates a rise in metabolic activity in this case. Studying the activity of kidney mitochondria of the three groups of animals using succinate as a substrate revealed that the P/O ratio tends to decrease in animals kept at 6 degrees C while the RCR value was not altered by changing conditions or produced by the different diets. At the temperature of 6 degrees C both the P/O ratios and the RCR values of liver mitochondria using succinate as a substrate decreased in the group of rabbits fed the basal and iodine diets, but were not significantly different in the group fed the PTU diet. In the experiment on kidney mitochondrial activity using alpha-ketoglutarate as a substrate it was found that both the P/O ratios and the RCR values from animals fed basal and PTU diets at 6 degrees C decreased slightly as compared with animals fed at 20 degrees C and 34 degrees C. In liver mitochondria, using alpha-ketoglutarate as a substrate a significant decrease in the P/O ratio and the RCR value was found for both rabbits fed the basal and the iodine diets at 6 degrees C. In the group of rabbits fed the PTU diet, the P/O ratio also decreased but the fall was not significant. These results suggested that the activity of succinate dehydrogenase in liver mitochondria increases in animals fed basal and iodine diets at 6 degrees C. The enzyme dehydrogenase involved in oxidation of alpha-ketoglutarate which is localized in the outer membrane of mitochondria seems to be affected by different temperatures and diets as compared with succinate

  7. The Swelling of Rat Liver Mitochondria by Thyroxine and its Reversal

    Science.gov (United States)

    Lehninger, Albert L.; Ray, Betty Lou; Schneider, Marion

    1959-01-01

    The in vitro swelling action of L-thyroxine on rat liver mitochondria as examined photometrically represents an acceleration of a process which the mitochondria are already inherently capable of undergoing spontaneously, as indicated by the identical kinetic characteristics and the extent of thyroxine-induced and spontaneous swelling, the nearly identical pH dependence, and the fact that sucrose has a specific inhibitory action on both types of swelling. However, thyroxine does not appear to be a "catalyst" or coenzyme since it does not decrease the temperature coefficient of spontaneous swelling. The temperature coefficient is very high, approximately 6.0 near 20°. Aging of mitochondria at 0° causes loss of thyroxine sensitivity which correlates closely with the loss of bound DPN from the mitochondria, but not with loss of activity of the respiratory chain or with the efficiency of oxidative phosphorylation. Tests with various respiratory chain inhibitors showed that the oxidation state of bound DPN may be a major determinant of thyroxine sensitivity; the oxidation state of the other respiratory carriers does not appear to influence sensitivity to thyroxine. These facts and other considerations suggest that a bound form of mitochondrial DPN is the "target" of the action of thyroxine. The thyroxine-induced swelling is not reversed by increasing the osmolar concentration of external sucrose, but can be "passively" or osmotically reversed by adding the high-particle weight solute polyvinylpyrrolidone. The mitochondrial membrane becomes more permeable to sucrose during the swelling reaction. On the other hand, thyroxine-induced swelling can be "actively" reversed by ATP in a medium of 0.15 M KCl or NaCl but not in a 0.30 M sucrose medium. The action of ATP is specific; ADP, Mn++, and ethylenediaminetetraacetate are not active. It is concluded that sucrose is an inhibitor of the enzymatic relationship between oxidative phosphorylation and the contractility and

  8. Diethylstilbestrol (DES)-stimulated hormonal toxicity is mediated by ERα alteration of target gene methylation patterns and epigenetic modifiers (DNMT3A, MBD2, and HDAC2) in the mouse seminal vesicle.

    Science.gov (United States)

    Li, Yin; Hamilton, Katherine J; Lai, Anne Y; Burns, Katherine A; Li, Leping; Wade, Paul A; Korach, Kenneth S

    2014-03-01

    Diethylstilbestrol (DES) is a synthetic estrogen associated with adverse effects on reproductive organs. DES-induced toxicity of the mouse seminal vesicle (SV) is mediated by estrogen receptor α (ERα), which alters expression of seminal vesicle secretory protein IV (Svs4) and lactoferrin (Ltf) genes. We examined a role for nuclear receptor activity in association with DNA methylation and altered gene expression. We used the neonatal DES exposure mouse model to examine DNA methylation patterns via bisulfite conversion sequencing in SVs of wild-type (WT) and ERα-knockout (αERKO) mice. The DNA methylation status at four specific CpGs (-160, -237, -306, and -367) in the Svs4 gene promoter changed during mouse development from methylated to unmethylated, and DES prevented this change at 10 weeks of age in WT SV. At two specific CpGs (-449 and -459) of the Ltf gene promoter, DES altered the methylation status from methylated to unmethylated. Alterations in DNA methylation of Svs4 and Ltf were not observed in αERKO SVs, suggesting that changes of methylation status at these CpGs are ERα dependent. The methylation status was associated with the level of gene expression. In addition, gene expression of three epigenetic modifiers-DNMT3A, MBD2, and HDAC2-increased in the SV of DES-exposed WT mice. DES-induced hormonal toxicity resulted from altered gene expression of Svs4 and Ltf associated with changes in DNA methylation that were mediated by ERα. Alterations in gene expression of DNMT3A, MBD2, and HDAC2 in DES-exposed male mice may be involved in mediating the changes in methylation status in the SV. Li Y, Hamilton KJ, Lai AY, Burns KA, Li L, Wade PA, Korach KS. 2014. Diethylstilbestrol (DES)-stimulated hormonal toxicity is mediated by ERα alteration of target gene methylation patterns and epigenetic modifiers (DNMT3A, MBD2, and HDAC2) in the mouse seminal vesicle. Environ Health Perspect 122:262-268; http://dx.doi.org/10.1289/ehp.1307351.

  9. The Utility of Impulsive Bias and Altered Decision Making as Predictors of Drug Efficacy and Target Selection: Rethinking Behavioral Screening for Antidepressant Drugs.

    Science.gov (United States)

    Marek, Gerard J; Day, Mark; Hudzik, Thomas J

    2016-03-01

    Cognitive dysfunction may be a core feature of major depressive disorder, including affective processing bias, abnormal response to negative feedback, changes in decision making, and increased impulsivity. Accordingly, a translational medicine paradigm predicts clinical action of novel antidepressants by examining drug-induced changes in affective processing bias. With some exceptions, these concepts have not been systematically applied to preclinical models to test new chemical entities. The purpose of this review is to examine whether an empirically derived behavioral screen for antidepressant drugs may screen for compounds, at least in part, by modulating an impulsive biasing of responding and altered decision making. The differential-reinforcement-of-low-rate (DRL) 72-second schedule is an operant schedule with a documented fidelity for discriminating antidepressant drugs from nonantidepressant drugs. However, a theoretical basis for this empirical relationship has been lacking. Therefore, this review will discuss whether response bias toward impulsive behavior may be a critical screening characteristic of DRL behavior requiring long inter-response times to obtain rewards. This review will compare and contrast DRL behavior with the five-choice serial reaction time task, a test specifically designed for assessing motoric impulsivity, with respect to psychopharmacological testing and the neural basis of distributed macrocircuits underlying these tasks. This comparison suggests that the existing empirical basis for the DRL 72-second schedule as a pharmacological screen for antidepressant drugs is complemented by a novel hypothesis that altering impulsive response bias for rodents trained on this operant schedule is a previously unrecognized theoretical cornerstone for this screening paradigm. Copyright © 2016 by The American Society for Pharmacology and Experimental Therapeutics.

  10. The dinoflagellates Durinskia baltica and Kryptoperidinium foliaceum retain functionally overlapping mitochondria from two evolutionarily distinct lineages

    Directory of Open Access Journals (Sweden)

    Keeling Patrick J

    2007-09-01

    Full Text Available Abtract Background The dinoflagellates Durinskia baltica and Kryptoperidinium foliaceum are distinguished by the presence of a tertiary plastid derived from a diatom endosymbiont. The diatom is fully integrated with the host cell cycle and is so altered in structure as to be difficult to recognize it as a diatom, and yet it retains a number of features normally lost in tertiary and secondary endosymbionts, most notably mitochondria. The dinoflagellate host is also reported to retain mitochondrion-like structures, making these cells unique in retaining two evolutionarily distinct mitochondria. This redundancy raises the question of whether the organelles share any functions in common or have distributed functions between them. Results We show that both host and endosymbiont mitochondrial genomes encode genes for electron transport proteins. We have characterized cytochrome c oxidase 1 (cox1, cytochrome oxidase 2 (cox2, cytochrome oxidase 3 (cox3, cytochrome b (cob, and large subunit of ribosomal RNA (LSUrRNA of endosymbiont mitochondrial ancestry, and cox1 and cob of host mitochondrial ancestry. We show that all genes are transcribed and that those ascribed to the host mitochondrial genome are extensively edited at the RNA level, as expected for a dinoflagellate mitochondrion-encoded gene. We also found evidence for extensive recombination in the host mitochondrial genes and that recombination products are also transcribed, as expected for a dinoflagellate. Conclusion Durinskia baltica and K. foliaceum retain two mitochondria from evolutionarily distinct lineages, and the functions of these organelles are at least partially overlapping, since both express genes for proteins in electron transport.

  11. Zinc-dependent multi-conductance channel activity in mitochondria isolated from ischemic brain.

    Science.gov (United States)

    Bonanni, Laura; Chachar, Mushtaque; Jover-Mengual, Teresa; Li, Hongmei; Jones, Adrienne; Yokota, Hidenori; Ofengeim, Dimitry; Flannery, Richard J; Miyawaki, Takahiro; Cho, Chang-Hoon; Polster, Brian M; Pypaert, Marc; Hardwick, J Marie; Sensi, Stefano L; Zukin, R Suzanne; Jonas, Elizabeth A

    2006-06-21

    Transient global ischemia is a neuronal insult that induces delayed cell death. A hallmark event in the early post-ischemic period is enhanced permeability of mitochondrial membranes. The precise mechanisms by which mitochondrial function is disrupted are, as yet, unclear. Here we show that global ischemia promotes alterations in mitochondrial membrane contact points, a rise in intramitochondrial Zn2+, and activation of large, multi-conductance channels in mitochondrial outer membranes by 1 h after insult. Mitochondrial channel activity was associated with enhanced protease activity and proteolytic cleavage of BCL-xL to generate its pro-death counterpart, deltaN-BCL-xL. The findings implicate deltaN-BCL-xL in large, multi-conductance channel activity. Consistent with this, large channel activity was mimicked by introduction of recombinant deltaN-BCL-xL to control mitochondria and blocked by introduction of a functional BCL-xL antibody to post-ischemic mitochondria via the patch pipette. Channel activity was also inhibited by nicotinamide adenine dinucleotide, indicative of a role for the voltage-dependent anion channel (VDAC) of the outer mitochondrial membrane. In vivo administration of the membrane-impermeant Zn2+ chelator CaEDTA before ischemia or in vitro application of the membrane-permeant Zn2+ chelator tetrakis-(2-pyridylmethyl) ethylenediamine attenuated channel activity, suggesting a requirement for Zn2+. These findings reveal a novel mechanism by which ischemic insults disrupt the functional integrity of the outer mitochondrial membrane and implicate deltaN-BCL-xL and VDAC in the large, Zn2+-dependent mitochondrial channels observed in post-ischemic hippocampal mitochondria.

  12. CA V is present in rat kidney mitochondria

    International Nuclear Information System (INIS)

    Dodgson, S.J.; Contino, L.C.

    1987-01-01

    Guinea pig liver mitochondria contain the unique carbonic anhydrase isozyme, CA V. Prior to sacrifice, 15 rats and 15 guinea pigs were either fed normal lab chow (group 1), starved 48 hours (group 2) or fed normal lab chow and given to drink only water with added HCl, pH 2.5 (group 3). Mitochondria were prepared from excised livers and kidneys. CA V activity of disrupted mitochondria was measured by 18 O-mass spectrometric technique at pH 7.4, 37 0 C, 25 mM NaHCO 3 . Mass spectrometric CA assays with intact kidney mitochondria localize CA V activity to the matrix, as was found for liver mitochondria. It has been shown in hepatocytes prepared from starved guinea pigs and rats that inhibition of CA V results in decreased rate of gluconeogenesis from pyruvate. These present results are in line with the published observation that rat kidneys are much more gluconeogenic than guinea pig, and that this is increased by starvation and acidosis

  13. Are mitochondria a permanent source of reactive oxygen species?

    Science.gov (United States)

    Staniek, K; Nohl, H

    2000-11-20

    The observation that in isolated mitochondria electrons may leak out of the respiratory chain to form superoxide radicals (O(2)(radical-)) has prompted the assumption that O(2)(radical-) formation is a compulsory by-product of respiration. Since mitochondrial O(2)(radical-) formation under homeostatic conditions could not be demonstrated in situ so far, conclusions drawn from isolated mitochondria must be considered with precaution. The present study reveals a link between electron deviation from the respiratory chain to oxygen and the coupling state in the presence of antimycin A. Another important factor is the analytical system applied for the detection of activated oxygen species. Due to the presence of superoxide dismutase in mitochondria, O(2)(radical-) release cannot be realistically determined in intact mitochondria. We therefore followed the release of the stable dismutation product H(2)O(2) by comparing most frequently used H(2)O(2) detection methods. The possible interaction of the detection systems with the respiratory chain was avoided by a recently developed method, which was compared with conventional methods. Irrespective of the methods applied, the substrates used for respiration and the state of respiration established, intact mitochondria could not be made to release H(2)O(2) from dismutating O(2)(radical-). Although regular mitochondrial respiration is unlikely to supply single electrons for O(2)(radical-) formation our study does not exclude the possibility of the respiratory chain becoming a radical source under certain conditions.

  14. Carvedilol prevents functional deficits in peripheral nerve mitochondria of rats with oxaliplatin-evoked painful peripheral neuropathy

    International Nuclear Information System (INIS)

    Areti, Aparna; Komirishetty, Prashanth; Kumar, Ashutosh

    2017-01-01

    Oxaliplatin use as chemotherapeutic agent is frequently limited by cumulative neurotoxicity which may compromise quality of life. Reports relate this neurotoxic effect to oxidative stress and mitochondrial dysfunction in peripheral nerves and dorsal root ganglion (DRG). Carvedilol is an antihypertensive drug, has also been appreciated for its antioxidant and mitoprotective properties. Carvedilol co-treatment did not reduce the anti-tumor effects of oxaliplatin in human colon cancer cells (HT-29), but exhibited free radical scavenging activity against oxaliplatin-induced oxidative stress in neuronal cells (Neuro-2a). Hence, the present study was designed to investigate the effect of carvedilol in the experimental model of oxaliplatin-induced peripheral neuropathy (OIPN) in Sprague-Dawley rats. Oxaliplatin reduced the sensory nerve conduction velocity and produced the thermal and mechanical nociception. Carvedilol significantly (P < 0.001) attenuated these functional and sensorimotor deficits. It also counteracted oxidative/nitrosative stress by reducing the levels of nitrotyrosine and improving the mitochondrial superoxide dismutase expression in both sciatic nerve and DRG tissues. It improved the mitochondrial function and prevented the oxaliplatin-induced alteration in mitochondrial membrane potential in sciatic nerve thus prevented loss of intra epidermal nerve fiber density in the foot pads. Together the results prompt the use of carvedilol along with chemotherapy with oxaliplatin to prevent the peripheral neuropathy. - Graphical abstract: Schematic representation neuroprotective mechanisms of carvedilol in oxaliplatin-induced peripheral neuropathy. - Highlights: • Oxaliplatin-induced mitochondrial dysfunction causes neurotoxicity. • Mitochondrial dysfunction leads to bioenergetic and functional deficits. • Carvedilol alleviated oxaliplatin-induced behavioural and functional changes. • Targeting mitochondria with carvedilol attenuated neuropathic pain.

  15. Carvedilol prevents functional deficits in peripheral nerve mitochondria of rats with oxaliplatin-evoked painful peripheral neuropathy

    Energy Technology Data Exchange (ETDEWEB)

    Areti, Aparna; Komirishetty, Prashanth; Kumar, Ashutosh, E-mail: ashutosh.niperhyd@gov.in

    2017-05-01

    Oxaliplatin use as chemotherapeutic agent is frequently limited by cumulative neurotoxicity which may compromise quality of life. Reports relate this neurotoxic effect to oxidative stress and mitochondrial dysfunction in peripheral nerves and dorsal root ganglion (DRG). Carvedilol is an antihypertensive drug, has also been appreciated for its antioxidant and mitoprotective properties. Carvedilol co-treatment did not reduce the anti-tumor effects of oxaliplatin in human colon cancer cells (HT-29), but exhibited free radical scavenging activity against oxaliplatin-induced oxidative stress in neuronal cells (Neuro-2a). Hence, the present study was designed to investigate the effect of carvedilol in the experimental model of oxaliplatin-induced peripheral neuropathy (OIPN) in Sprague-Dawley rats. Oxaliplatin reduced the sensory nerve conduction velocity and produced the thermal and mechanical nociception. Carvedilol significantly (P < 0.001) attenuated these functional and sensorimotor deficits. It also counteracted oxidative/nitrosative stress by reducing the levels of nitrotyrosine and improving the mitochondrial superoxide dismutase expression in both sciatic nerve and DRG tissues. It improved the mitochondrial function and prevented the oxaliplatin-induced alteration in mitochondrial membrane potential in sciatic nerve thus prevented loss of intra epidermal nerve fiber density in the foot pads. Together the results prompt the use of carvedilol along with chemotherapy with oxaliplatin to prevent the peripheral neuropathy. - Graphical abstract: Schematic representation neuroprotective mechanisms of carvedilol in oxaliplatin-induced peripheral neuropathy. - Highlights: • Oxaliplatin-induced mitochondrial dysfunction causes neurotoxicity. • Mitochondrial dysfunction leads to bioenergetic and functional deficits. • Carvedilol alleviated oxaliplatin-induced behavioural and functional changes. • Targeting mitochondria with carvedilol attenuated neuropathic pain.

  16. Shengjiang Xiexin Decoction Alters Pharmacokinetics of Irinotecan by Regulating Metabolic Enzymes and Transporters: A Multi-Target Therapy for Alleviating the Gastrointestinal Toxicity.

    Science.gov (United States)

    Guan, Huan-Yu; Li, Peng-Fei; Wang, Xiao-Ming; Yue, Jia-Jing; He, Yang; Luo, Xiao-Mei; Su, Mei-Feng; Liao, Shang-Gao; Shi, Yue

    2017-01-01

    Shengjiang Xiexin decoction (SXD), a classic traditional Chinese medical formula chronicled in Shang Han Lun , is used in modern clinical practice to decrease gastrointestinal toxicity induced by the chemotherapeutic drug irinotecan (CPT-11). In this study, the effect of SXD on the pharmacokinetics of CPT-11 and its active metabolites (SN-38 and SN-38G), and the underlying mechanisms were further examined. An ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method was developed and validated for the simultaneous quantification of CPT-11, SN-38, and SN-38G in the plasma, bile, liver, intestine, and intestinal contents of control and SXD-pre-treated rats after intravenous administration of CPT-11. SXD pretreatment increased the area under the curve (AUC) and the initial plasma concentration (C 0 ) of CPT-11 but decreased the plasma clearance (CL). The AUC and the maximum plasma concentration (C max ) of SN-38 decreased, whereas the C max of SN-38G increased. Compared with that of the control group, the biliary excretion of CPT-11, SN-38, and SN-38G was inhibited. The CPT-11, SN-38, and SN-38G concentrations in the liver, intestine, and intestinal contents were different between the two groups. Furthermore, the hepatic expression of multidrug resistance-associated protein-2 (Mrp-2), P-glycoprotein (P-gp), and carboxylesterase 2 (CES2) was significantly down-regulated by SXD, while the hepatic and jejunal uridine diphosphate (UDP)-glucuronosyltransferase 1A1 (UGT1A1) expression was elevated. The hydrolysis of CPT-11 to SN-38 by CES and the glucuronidation of SN-38 to SN-38G by UGT were affected by liver and jejunum S9 fractions from rats pre-treated with SXD. Therefore, this study demonstrated for the first time that SXD could alter the pharmacokinetics of CPT-11 and its metabolites to alleviate CPT-11-induced diarrhea. And the underlying mechanism of drug interaction between CPT-11 and SXD involves decreasing hepatic Mrp-2 and P

  17. Shengjiang Xiexin Decoction Alters Pharmacokinetics of Irinotecan by Regulating Metabolic Enzymes and Transporters: A Multi-Target Therapy for Alleviating the Gastrointestinal Toxicity

    Directory of Open Access Journals (Sweden)

    Huan-yu Guan

    2017-10-01

    Full Text Available Shengjiang Xiexin decoction (SXD, a classic traditional Chinese medical formula chronicled in Shang Han Lun, is used in modern clinical practice to decrease gastrointestinal toxicity induced by the chemotherapeutic drug irinotecan (CPT-11. In this study, the effect of SXD on the pharmacokinetics of CPT-11 and its active metabolites (SN-38 and SN-38G, and the underlying mechanisms were further examined. An ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS method was developed and validated for the simultaneous quantification of CPT-11, SN-38, and SN-38G in the plasma, bile, liver, intestine, and intestinal contents of control and SXD-pre-treated rats after intravenous administration of CPT-11. SXD pretreatment increased the area under the curve (AUC and the initial plasma concentration (C0 of CPT-11 but decreased the plasma clearance (CL. The AUC and the maximum plasma concentration (Cmax of SN-38 decreased, whereas the Cmax of SN-38G increased. Compared with that of the control group, the biliary excretion of CPT-11, SN-38, and SN-38G was inhibited. The CPT-11, SN-38, and SN-38G concentrations in the liver, intestine, and intestinal contents were different between the two groups. Furthermore, the hepatic expression of multidrug resistance-associated protein-2 (Mrp-2, P-glycoprotein (P-gp, and carboxylesterase 2 (CES2 was significantly down-regulated by SXD, while the hepatic and jejunal uridine diphosphate (UDP-glucuronosyltransferase 1A1 (UGT1A1 expression was elevated. The hydrolysis of CPT-11 to SN-38 by CES and the glucuronidation of SN-38 to SN-38G by UGT were affected by liver and jejunum S9 fractions from rats pre-treated with SXD. Therefore, this study demonstrated for the first time that SXD could alter the pharmacokinetics of CPT-11 and its metabolites to alleviate CPT-11-induced diarrhea. And the underlying mechanism of drug interaction between CPT-11 and SXD involves decreasing hepatic Mrp-2 and P

  18. Targeting Glial Mitochondrial Function for Protection from Cerebral Ischemia: Relevance, Mechanisms, and the Role of MicroRNAs

    Directory of Open Access Journals (Sweden)

    Le Li

    2016-01-01

    Full Text Available Astrocytes and microglia play crucial roles in the response to cerebral ischemia and are effective targets for stroke therapy in animal models. MicroRNAs (miRs are important posttranscriptional regulators of gene expression that function by inhibiting the translation of select target genes. In astrocytes, miR expression patterns regulate mitochondrial function in response to oxidative stress via targeting of Bcl2 and heat shock protein 70 family members. Mitochondria play an active role in microglial activation, and miRs regulate the microglial neuroinflammatory response. As endogenous miR expression patterns can be altered with exogenous mimics and inhibitors, miR-targeted therapies represent a viable intervention to optimize glial mitochondrial function and improve clinical outcome following cerebral ischemia. In the present article, we review the role that astrocytes and microglia play in neuronal function and fate following ischemic stress, discuss the relevance of mitochondria in the glial response to injury, and present current evidence implicating miRs as critical regulators in the glial mitochondrial response to cerebral ischemia.

  19. Targeted disruption of the Mast syndrome gene SPG21 in mice impairs hind limb function and alters axon branching in cultured cortical neurons

    Science.gov (United States)

    Soderblom, Cynthia; Stadler, Julia; Jupille, Henri; Blackstone, Craig; Shupliakov, Oleg

    2017-01-01

    Mast syndrome (SPG21) is a childhood-onset, autosomal recessive, complicated form of hereditary spastic paraplegia (HSP) characterized by dementia, thin corpus callosum, white matter abnormalities, and cerebellar and extrapyramidal signs in addition to spastic paraparesis. A nucleotide insertion resulting in premature truncation of the SPG21 gene product maspardin underlies this disorder, likely leading to loss of protein function. In this study, we generated SPG21−/− knockout mice by homologous recombination as a possible animal model for SPG21. Though SPG21−/− mice appeared normal at birth, within several months they developed gradually progressive hind limb dysfunction. Cerebral cortical neurons cultured from SPG21−/− mice exhibited significantly more axonal branching than neurons from wild-type animals, while comprehensive neuropathological analysis of SPG21−/− mice did not reveal definitive abnormalities. Since alterations in axon branching have been seen in neurons derived from animal models of other forms of HSP as well as motor neuron diseases, this may represent a common cellular pathogenic theme. PMID:20661613

  20. Aspirin Induces Apoptosis through Release of Cytochrome c from Mitochondria

    Directory of Open Access Journals (Sweden)

    Katja C. Zimmermann

    2000-01-01

    Full Text Available Nonsteroidal anti-inflammatory drugs (NSAID reduce the risk for cancer, due to their anti proliferative and apoptosis-inducing effects. A critical pathway for apoptosis involves the release of cytochrome c from mitochondria, which then interacts with Apaf-1 to activate caspase proteases that orchestrate cell death. In this study we found that treatment of a human cancer cell line with aspirin induced caspase activation and the apoptotic cell morphology, which was blocked by the caspase inhibitor zVAD-fmk. Further analysis of the mechanism underlying this apoptotic event showed that aspirin induces translocation of Bax to the mitochondria and triggers release of cytochrome c into the cytosol. The release of cytochrome c from mitochondria was inhibited by overexpression of the antiapoptotic protein Bcl-2 and cells that lack Apaf-1 were resistant to aspirin-induced apoptosis. These data provide evidence that the release of cytochrome c is an important part of the apoptotic mechanism of aspirin.

  1. Doxorubicin Action on Mitochondria: Relevance to Osteosarcoma Therapy?

    Science.gov (United States)

    Armstrong, Jo; Dass, Crispin R

    2018-01-01

    The mitochondria may very well determine the final commitment of the cell to death, particularly in times of energy stress. Cancer chemotherapeutics such as the anthracycline doxorubicin perturb mitochondrial structure and function in tumour cells, as evidenced in osteosarcoma, for which doxorubicin is used clinically as frontline therapy. This same mechanism of cell inhibition is also pertinent to doxorubicin's primary cause of side-effects, that to the cardiac tissue, culminating in such dire events as congestive heart failure. Reactive oxygen species are partly to blame for this effect on the mitochondria, which impact the electron transport chain. As this review highlights that, there is much more to be learnt about the mitochondria and how it is affected by such effective but toxic drugs as doxorubicin. Such information will aid researchers who search for cancer treatment able to preserve mitochondrial number and function in normal cells. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  2. [Organization of mitochondria in the growing hyphae of Neurospora crassa].

    Science.gov (United States)

    Potapova, T V; Boĭtsova, L Iu; Golyshev, S A; Popinako, A V

    2013-01-01

    In vivo fluorescent labeling of mitochondria in Neurospora crassa showed the concentration of filamentous mitochondria within 30 μm of apex in growing hyphae. These mitochondrial assemblies propagated forward with the elongation of hyphae, split and segregated as the growing tip bifurcated and formed de novo when new branches formed farther away from the apex. The efficiency of the mitochondria concentration in the apical 30 μm zone is related to the growth rate and identical in hyphae cultivated in glucose- and sorbitol-containing media. The obtained data are discussed in connection with the behavior of microtubules in growing hyphae as well as with the electric heterogeneity of N. crassa hyphal apex described previously.

  3. Effects of ambroxol on the autophagy-lysosome pathway and mitochondria in primary cortical neurons.

    Science.gov (United States)

    Magalhaes, J; Gegg, M E; Migdalska-Richards, A; Schapira, A H

    2018-01-23

    Glucocerebrosidase (GBA1) mutations are the major genetic risk factor for Parkinson's Disease (PD). The pathogenic mechanism is still unclear, but alterations in lysosomal-autophagy processes are implicated due to reduction of mutated glucocerebrosidase (GCase) in lysosomes. Wild-type GCase activity is also decreased in sporadic PD brains. Small molecule chaperones that increase lysosomal GCase activity have potential to be disease-modifying therapies for GBA1-associated and sporadic PD. Therefore we have used mouse cortical neurons to explore the effects of the chaperone ambroxol. This chaperone increased wild-type GCase mRNA, protein levels and activity, as well as increasing other lysosomal enzymes and LIMP2, the GCase transporter. Transcription factor EB (TFEB), the master regulator of the CLEAR pathway involved in lysosomal biogenesis was also increased upon ambroxol treatment. Moreover, we found macroautophagy flux blocked and exocytosis increased in neurons treated with ambroxol. We suggest that ambroxol is blocking autophagy and driving cargo towards the secretory pathway. Mitochondria content was also found to be increased by ambroxol via peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC1-α). Our data suggest that ambroxol, besides being a GCase chaperone, also acts on other pathways, such as mitochondria, lysosomal biogenesis, and the secretory pathway.

  4. Biogenesis and dynamics of mitochondria during the cell cycle: significance of 3'UTRs.

    Directory of Open Access Journals (Sweden)

    Marta Martínez-Diez

    Full Text Available Nowadays, we are facing a renaissance of mitochondria in cancer biology. However, our knowledge of the basic cell biology and on the timing and mechanisms that control the biosynthesis of mitochondrial constituents during progression through the cell cycle of mammalian cells remain largely unknown. Herein, we document the in vivo changes on mitochondrial morphology and dynamics that accompany cellular mitosis, and illustrate the following key points of the biogenesis of mitochondria during progression of liver cells through the cycle: (i the replication of nuclear and mitochondrial genomes is synchronized during cellular proliferation, (ii the accretion of OXPHOS proteins is asynchronously regulated during proliferation being the synthesis of beta-F1-ATPase and Hsp60 carried out also at G2/M and, (iii the biosynthesis of cardiolipin is achieved during the S phase, although full development of the mitochondrial membrane potential (DeltaPsim is attained at G2/M. Furthermore, we demonstrate using reporter constructs that the mechanism regulating the accretion of beta-F1-ATPase during cellular proliferation is controlled at the level of mRNA translation by the 3'UTR of the transcript. The 3'UTR-driven synthesis of the protein at G2/M is essential for conferring to the daughter cells the original phenotype of the parental cell. Our findings suggest that alterations on this process may promote deregulated beta-F1-ATPase expression in human cancer.

  5. Fe-S Cluster Biogenesis in Isolated Mammalian Mitochondria

    Science.gov (United States)

    Pandey, Alok; Pain, Jayashree; Ghosh, Arnab K.; Dancis, Andrew; Pain, Debkumar

    2015-01-01

    Iron-sulfur (Fe-S) clusters are essential cofactors, and mitochondria contain several Fe-S proteins, including the [4Fe-4S] protein aconitase and the [2Fe-2S] protein ferredoxin. Fe-S cluster assembly of these proteins occurs within mitochondria. Although considerable data exist for yeast mitochondria, this biosynthetic process has never been directly demonstrated in mammalian mitochondria. Using [35S]cysteine as the source of sulfur, here we show that mitochondria isolated from Cath.A-derived cells, a murine neuronal cell line, can synthesize and insert new Fe-35S clusters into aconitase and ferredoxins. The process requires GTP, NADH, ATP, and iron, and hydrolysis of both GTP and ATP is necessary. Importantly, we have identified the 35S-labeled persulfide on the NFS1 cysteine desulfurase as a genuine intermediate en route to Fe-S cluster synthesis. In physiological settings, the persulfide sulfur is released from NFS1 and transferred to a scaffold protein, where it combines with iron to form an Fe-S cluster intermediate. We found that the release of persulfide sulfur from NFS1 requires iron, showing that the use of iron and sulfur for the synthesis of Fe-S cluster intermediates is a highly coordinated process. The release of persulfide sulfur also requires GTP and NADH, probably mediated by a GTPase and a reductase, respectively. ATP, a cofactor for a multifunctional Hsp70 chaperone, is not required at this step. The experimental system described here may help to define the biochemical basis of diseases that are associated with impaired Fe-S cluster biogenesis in mitochondria, such as Friedreich ataxia. PMID:25398879

  6. GENE TRANSFER IN TOBACCO MITOCHONDRIA IN VITRO AND IN VIVO

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    Katyshev A.I.

    2012-08-01

    Full Text Available Earlier, we had showed that isolated mitochondria from different organisms can import DNA. Exploiting this mechanism, we assessed the possibility of genes transfer in tobacco mitochondria in vitro and in vivo. Whereas homologous recombination is a rare occasion in higher plant nuclei, recombination between the large direct repeats in plant mitochondrial genome generates its multipartite structure. Following transfection of isolated organelles with constructs composed of a partial gfp gene flanked by mitochondrial DNA fragments, we showed the homologous recombination of imported DNA with the resident DNA and the integration of the reporter gene. The recombination yielded an insertion of a continuous exogenous DNA fragment including the gfp sequence and at least the 0.5 kb of the flanking sequence on each side. Using of transfection constructs carrying multiple sequences homologous to mitochondrial DNA could be suitable for insertion of a target gene into any region of the mitochondrial genome, which turns this approach to be of a general and methodical importance. Usually mitochondrial reactive oxygen species (ROS level is under strict control of the antioxidant system including the Mn-containing superoxide dismutase (MnSOD. MnSOD is presented in multiple forms encoded by several genes in plants. Possibly, this enzyme, beside its catalytic function, fulfills as well some unknown biochemical functions. Thus, one of maize SOD enzymes (SOD3.4 could bind with mitochondrial DNA. Another SOD form (SOD3.1 is located in close proximity to mitochondrial respiratory complexes, where ROS are generated. To study possible physiological functions of this enzyme, we cloned the maize SOD3.1 gene. Compared to the SOD3.4, this enzyme didn't demonstrate DNA-binding activity. At the same time, SOD3.1 didn't show non-specific DNA-hydrolyzing activity as Cu/ZnSOD does. It means that this enzyme might have some DNA protective function. We made NtPcob-sod3.1-IGR

  7. Discovery and Targeted LC-MS/MS of Purified Polerovirus Reveals Differences in the Virus-Host Interactome Associated with Altered Aphid Transmission

    Science.gov (United States)

    Howe, Kevin; Fish, Tara; Smith, Dawn; Gildow, Fredrick; MacCoss, Michael J.; Thannhauser, Theodore W.; Gray, Stewart M.

    2012-01-01

    Circulative transmission of viruses in the Luteoviridae, such as cereal yellow dwarf virus (CYDV), requires a series of precisely orchestrated interactions between virus, plant, and aphid proteins. Natural selection has favored these viruses to be retained in the phloem to facilitate acquisition and transmission by aphids. We show that treatment of infected oat tissue homogenate with sodium sulfite reduces transmission of the purified virus by aphids. Transmission electron microscopy data indicated no gross change in virion morphology due to treatments. However, treated virions were not acquired by aphids through the hindgut epithelial cells and were not transmitted when injected directly into the hemocoel. Analysis of virus preparations using nanoflow liquid chromatography coupled to tandem mass spectrometry revealed a number of host plant proteins co-purifying with viruses, some of which were lost following sodium sulfite treatment. Using targeted mass spectrometry, we show data suggesting that several of the virus-associated host plant proteins accumulated to higher levels in aphids that were fed on CYDV-infected plants compared to healthy plants. We propose two hypotheses to explain these observations, and these are not mutually exclusive: (a) that sodium sulfite treatment disrupts critical virion-host protein interactions required for aphid transmission, or (b) that host infection with CYDV modulates phloem protein expression in a way that is favorable for virus uptake by aphids. Importantly, the genes coding for the plant proteins associated with virus may be examined as targets in breeding cereal crops for new modes of virus resistance that disrupt phloem-virus or aphid-virus interactions. PMID:23118947

  8. Discovery and targeted LC-MS/MS of purified polerovirus reveals differences in the virus-host interactome associated with altered aphid transmission.

    Directory of Open Access Journals (Sweden)

    Michelle Cilia

    Full Text Available Circulative transmission of viruses in the Luteoviridae, such as cereal yellow dwarf virus (CYDV, requires a series of precisely orchestrated interactions between virus, plant, and aphid proteins. Natural selection has favored these viruses to be retained in the phloem to facilitate acquisition and transmission by aphids. We show that treatment of infected oat tissue homogenate with sodium sulfite reduces transmission of the purified virus by aphids. Transmission electron microscopy data indicated no gross change in virion morphology due to treatments. However, treated virions were not acquired by aphids through the hindgut epithelial cells and were not transmitted when injected directly into the hemocoel. Analysis of virus preparations using nanoflow liquid chromatography coupled to tandem mass spectrometry revealed a number of host plant proteins co-purifying with viruses, some of which were lost following sodium sulfite treatment. Using targeted mass spectrometry, we show data suggesting that several of the virus-associated host plant proteins accumulated to higher levels in aphids that were fed on CYDV-infected plants compared to healthy plants. We propose two hypotheses to explain these observations, and these are not mutually exclusive: (a that sodium sulfite treatment disrupts critical virion-host protein interactions required for aphid transmission, or (b that host infection with CYDV modulates phloem protein expression in a way that is favorable for virus uptake by aphids. Importantly, the genes coding for the plant proteins associated with virus may be examined as targets in breeding cereal crops for new modes of virus resistance that disrupt phloem-virus or aphid-virus interactions.

  9. Discovery and targeted LC-MS/MS of purified polerovirus reveals differences in the virus-host interactome associated with altered aphid transmission.

    Science.gov (United States)

    Cilia, Michelle; Peter, Kari A; Bereman, Michael S; Howe, Kevin; Fish, Tara; Smith, Dawn; Gildow, Fredrick; MacCoss, Michael J; Thannhauser, Theodore W; Gray, Stewart M

    2012-01-01

    Circulative transmission of viruses in the Luteoviridae, such as cereal yellow dwarf virus (CYDV), requires a series of precisely orchestrated interactions between virus, plant, and aphid proteins. Natural selection has favored these viruses to be retained in the phloem to facilitate acquisition and transmission by aphids. We show that treatment of infected oat tissue homogenate with sodium sulfite reduces transmission of the purified virus by aphids. Transmission electron microscopy data indicated no gross change in virion morphology due to treatments. However, treated virions were not acquired by aphids through the hindgut epithelial cells and were not transmitted when injected directly into the hemocoel. Analysis of virus preparations using nanoflow liquid chromatography coupled to tandem mass spectrometry revealed a number of host plant proteins co-purifying with viruses, some of which were lost following sodium sulfite treatment. Using targeted mass spectrometry, we show data suggesting that several of the virus-associated host plant proteins accumulated to higher levels in aphids that were fed on CYDV-infected plants compared to healthy plants. We propose two hypotheses to explain these observations, and these are not mutually exclusive: (a) that sodium sulfite treatment disrupts critical virion-host protein interactions required for aphid transmission, or (b) that host infection with CYDV modulates phloem protein expression in a way that is favorable for virus uptake by aphids. Importantly, the genes coding for the plant proteins associated with virus may be examined as targets in breeding cereal crops for new modes of virus resistance that disrupt phloem-virus or aphid-virus interactions.

  10. Ethanol modulation of mammalian BK channels in excitable tissues: molecular targets and their possible contribution to alcohol-induced altered behavior

    Directory of Open Access Journals (Sweden)

    Alex M. Dopico

    2014-12-01

    Full Text Available In most tissues, the function of calcium- and voltage-gated potassium (BK channels is modified in response to ethanol concentrations reached in human blood during alcohol intoxication. In general, modification of BK current from ethanol-naïve preparations in response to brief ethanol exposure results from changes in channel open probability without modification of unitary conductance or change in BK protein levels in the membrane. Protracted and/or repeated ethanol exposure, however, may evoke changes in BK expression. The final ethanol effect on BK open probability leading to either BK current potentiation or BK current reduction is determined by an orchestration of molecular factors, including levels of activating ligand (cytosolic calcium, BK subunit composition and posttranslational modifications, and the channel’s lipid microenvironment. These factors seem to allosterically regulate a direct interaction between ethanol and a recognition pocket of discrete dimensions recently mapped to the channel-forming (slo1 subunit. Type of ethanol exposure also plays a role in the final BK response to the drug: in several central nervous system regions (e.g., striatum, primary sensory neurons, and supraoptic nucleus, acute exposure to ethanol reduces neuronal excitability by enhancing BK activity. In contrast, protracted or repetitive ethanol administration may alter BK subunit composition and membrane expression, rendering the BK complex insensitive to further ethanol exposure. In neurohypophysial axon terminals, ethanol potentiation of BK channel activity leads to a reduction in neuropeptide release. In vascular smooth muscle, however, ethanol inhibition of BK current leads to cell contraction and vascular constriction.

  11. Ambient salinity modifies the action of triiodothyronine in the air-breathing fish Anabas testudineus Bloch: effects on mitochondria-rich cell distribution, osmotic and metabolic regulations.

    Science.gov (United States)

    Peter, M C Subhash; Leji, J; Peter, Valsa S

    2011-04-01

    The hydromineral and metabolic actions of thyroid hormone on osmotic acclimation in fish is less understood. We, therefore, studied the short-term action of triiodothyronine (T(3)), the potent thyroid hormone, on the distribution and the function of gill mitochondria-rich (MR) cells and on the whole body hydromineral and metabolic regulations of air-breathing fish (Anabas testudineus) adapted to either freshwater (FW) or acclimated to seawater (SA; 30 g L(-1)). As expected, 24 h T(3) injection (100 ng g(-1)) elevated (Pfish, suggest an action of T(3) on gill MR cell migration, though the density of these cells remained unchanged after T(3) treatment. The ouabain-sensitive Na(+), K(+)-ATPase activity, a measure of hydromineral competence, showed increases (Pfish after T(3) administration, but inhibited (Pfish and not in the SA fish. Exogenous T(3) reduced glucose (Pfish, whereas these metabolites were elevated (Pfish, suggesting a modulatory effect of ambient salinity on the T(3)-driven metabolic actions. Our data identify gill MR cell as a target for T(3) action as it promotes the spatial distribution and the osmotic function of these cells in both fresh water and in seawater. The results besides confirming the metabolic and osmotic actions of T(3) in fish support the hypothesis that the differential actions of T(3) may be due to the direct influence of ambient salinity, a major environmental determinant that alters the osmotic and metabolic strategies of fish. Copyright © 2011 Elsevier Inc. All rights reserved.

  12. New nanocomposites for SERS studies of living cells and mitochondria

    DEFF Research Database (Denmark)

    Sarycheva, A. S.; Brazhe, N. A.; Baizhumanov, A. A.

    2016-01-01

    A great enhancement in Raman scattering (SERS) from heme-containing submembrane biomolecules inside intact erythrocytes and functional mitochondria is demonstrated for the first time using silver–silica beads prepared using a new method involving aerosol pyrolysis with aqueous diamminesilver...... molecules. The SERS spectra of functional mitochondria are sensitive to the activity of the mitochondrial electron transport chain, thus making the method a novel label-free approach to monitor the redox state and conformation of cytochromes in their natural cell environment. The developed nanocomposites...

  13. miR-24-2 controls H2AFX expression regardless of gene copy number alteration and induces apoptosis by targeting antiapoptotic gene BCL-2: a potential for therapeutic intervention.

    Science.gov (United States)

    Srivastava, Niloo; Manvati, Siddharth; Srivastava, Archita; Pal, Ranjana; Kalaiarasan, Ponnusamy; Chattopadhyay, Shilpi; Gochhait, Sailesh; Dua, Raina; Bamezai, Rameshwar N K

    2011-04-04

    New levels of gene regulation with microRNA (miR) and gene copy number alterations (CNAs) have been identified as playing a role in various cancers. We have previously reported that sporadic breast cancer tissues exhibit significant alteration in H2AX gene copy number. However, how CNA affects gene expression and what is the role of miR, miR-24-2, known to regulate H2AX expression, in the background of the change in copy number, are not known. Further, many miRs, including miR-24-2, are implicated as playing a role in cell proliferation and apoptosis, but their specific target genes and the pathways contributing to them remain unexplored. Changes in gene copy number and mRNA/miR expression were estimated using real-time polymerase chain reaction assays in two mammalian cell lines, MCF-7 and HeLa, and in a set of sporadic breast cancer tissues. In silico analysis was performed to find the putative target for miR-24-2. MCF-7 cells were transfected with precursor miR-24-2 oligonucleotides, and the gene expression levels of BRCA1, BRCA2, ATM, MDM2, TP53, CHEK2, CYT-C, BCL-2, H2AFX and P21 were examined using TaqMan gene expression assays. Apoptosis was measured by flow cytometric detection using annexin V dye. A luciferase assay was performed to confirm BCL-2 as a valid cellular target of miR-24-2. It was observed that H2AX gene expression was negatively correlated with miR-24-2 expression and not in accordance with the gene copy number status, both in cell lines and in sporadic breast tumor tissues. Further, the cells overexpressing miR-24-2 were observed to be hypersensitive to DNA damaging drugs, undergoing apoptotic cell death, suggesting the potentiating effect of mir-24-2-mediated apoptotic induction in human cancer cell lines treated with anticancer drugs. BCL-2 was identified as a novel cellular target of miR-24-2. mir-24-2 is capable of inducing apoptosis by modulating different apoptotic pathways and targeting BCL-2, an antiapoptotic gene. The study suggests

  14. Organelle targeting: third level of drug targeting

    Directory of Open Access Journals (Sweden)

    Sakhrani NM

    2013-07-01

    Full Text Available Niraj M Sakhrani, Harish PadhDepartment of Cell and Molecular Biology, BV Patel Pharmaceutical Education and Research Development (PERD Centre, Gujarat, IndiaAbstract: Drug discovery and drug delivery are two main aspects for treatment of a variety of disorders. However, the real bottleneck associated with systemic drug administration is the lack of target-specific affinity toward a pathological site, resulting in systemic toxicity and innumerable other side effects as well as higher dosage requirement for efficacy. An attractive strategy to increase the therapeutic index of a drug is to specifically deliver the therapeutic molecule in its active form, not only into target tissue, nor even to target cells, but more importantly, into the targeted organelle, ie, to its intracellular therapeutic active site. This would ensure improved efficacy and minimize toxicity. Cancer chemotherapy today faces the major challenge of delivering chemotherapeutic drugs exclusively to tumor cells, while sparing normal proliferating cells. Nanoparticles play a crucial role by acting as a vehicle for delivery of drugs to target sites inside tumor cells. In this review, we spotlight active and passive targeting, followed by discussion of the importance of targeting to specific cell organelles and the potential role of cell-penetrating peptides. Finally, the discussion will address the strategies for drug/DNA targeting to lysosomes, mitochondria, nuclei and Golgi/endoplasmic reticulum.Keywords: intracellular drug delivery, cancer chemotherapy, therapeutic index, cell penetrating peptides

  15. Erythroid precursors from patients with low-risk myelodysplasia demonstrate ultrastructural features of enhanced autophagy of mitochondria

    NARCIS (Netherlands)

    Houwerzijl, E. J.; Pol, H-W D.; Blom, N. R.; van der Want, J. J. L.; de Wolf, J. Thm; Vellenga, E.

    Recent studies in erythroid cells have shown that autophagy is an important process for the physiological clearance of mitochondria during terminal differentiation. However, autophagy also plays an important role in removing damaged and dysfunctional mitochondria. Defective mitochondria and impaired

  16. Effect of vitamin D3, other drugs altering serum calcium or phosphorus concentrations, and desoxycorticosterone on the distribution of Tc-99m pyrophosphate between target and nontarget tissues

    International Nuclear Information System (INIS)

    Carr, E.A. Jr.; Carroll, M.; Montes, M.

    1981-01-01

    Radioactive imaging agents are chemically designed for selective distribution. Another approach to selectivity is to find stable compounds that favorably influence this distribution. Using a rat model of myocardial necrosis, we studied effects of various stable compounds (as a single, large dose or fractionated into short series) on the ratio, uptake of Tc-99m pyrophosphate (PPi) by the target lesion/uptake by the principal nontarget, bone (L/B). Vitamin D3s ability to increase L/B was mediated by the hypercalcemia and hyperphosphatemia that it caused. The hypercalcemia was accompanied by increased [Ca] in the lesion. In contrast, pulse doses of desoxycorticosterone acetate (DOCA) at 7 and 6 hr before killing increased uptake by lesion, increasing L/B from 0.19 +/- 0.03 to 0.45 +/- 0.08 (p less than 0.01), with no change in serum [Ca] and minimal changes in serum [P], [Na], and [K]. DOCA also increased the lesion-to-blood ratio from 6.5 +/- 0.07 to 15.4 +/- 3.9 (p less than 0.05). These results encourage further study of DOCA's effect and investigation of other stable drugs that may influence distribution of other imaging agents

  17. TARGET Research Goals

    Science.gov (United States)

    TARGET researchers use various sequencing and array-based methods to examine the genomes, transcriptomes, and for some diseases epigenomes of select childhood cancers. This “multi-omic” approach generates a comprehensive profile of molecular alterations for each cancer type. Alterations are changes in DNA or RNA, such as rearrangements in chromosome structure or variations in gene expression, respectively. Through computational analyses and assays to validate biological function, TARGET researchers predict which alterations disrupt the function of a gene or pathway and promote cancer growth, progression, and/or survival. Researchers identify candidate therapeutic targets and/or prognostic markers from the cancer-associated alterations.

  18. Ca2+-associated triphasic pH changes in mitochondria during brown adipocyte activation.

    Science.gov (United States)

    Hou, Yanyan; Kitaguchi, Tetsuya; Kriszt, Rókus; Tseng, Yu-Hua; Raghunath, Michael; Suzuki, Madoka

    2017-08-01

    Brown adipocytes (BAs) are endowed with a high metabolic capacity for energy expenditure due to their high mitochondria content. While mitochondrial pH is dynamically regulated in response to stimulation and, in return, affects various metabolic processes, how mitochondrial pH is regulated during adrenergic stimulation-induced thermogenesis is unknown. We aimed to reveal the spatial and temporal dynamics of mitochondrial pH in stimulated BAs and the mechanisms behind the dynamic pH changes. A mitochondrial targeted pH-sensitive protein, mito-pHluorin, was constructed and transfected to BAs. Transfected BAs were stimulated by an adrenergic agonist, isoproterenol. The pH changes in mitochondria were characterized by dual-color imaging with indicators that monitor mitochondrial membrane potential and heat production. The mechanisms of pH changes were studied by examining the involvement of electron transport chain (ETC) activity and Ca 2+ profiles in mitochondria and the intracellular Ca 2+ store, the endoplasmic reticulum (ER). A triphasic mitochondrial pH change in BAs upon adrenergic stimulation was revealed. In comparison to a thermosensitive dye, we reveal that phases 1 and 2 of the pH increase precede thermogenesis, while phase 3, characterized by a pH decrease, occurs during thermogenesis. The mechanism of pH increase is partially related to ETC. In addition, the pH increase occurs concurrently with an increase in mitochondrial Ca 2+ . This Ca 2+ increase is contributed to by an influx from the ER, and it is further involved in mitochondrial pH regulation. We demonstrate that an increase in mitochondrial pH is implicated as an early event in adrenergically stimulated BAs. We further suggest that this pH increase may play a role in the potentiation of thermogenesis.

  19. Bcl-xL-mediated remodeling of rod and cone synaptic mitochondria after postnatal lead exposure: electron microscopy, tomography and oxygen consumption.

    Science.gov (United States)

    Perkins, Guy A; Scott, Ray; Perez, Alex; Ellisman, Mark H; Johnson, Jerry E; Fox, Donald A

    2012-01-01

    and dark-adapted photoreceptor synaptic terminal QO(2). Bcl-xL partially blocked many of the lead-induced alterations relative to controls. However, spherules still had partially decreased abundance, whereas pedicles still had increased branching, increased crista segments per volume, and increased crista junction diameter. Moreover, photoreceptor and synaptic QO(2) were only partially recovered. These findings reveal cellular and compartmental specific differences in the structure and vulnerability of rod and cone inner segment and synaptic mitochondria to postnatal lead exposure. Spherule and pedicle mitochondria in lead-exposed mice displayed complex and distinguishing patterns of cristae and matrix damage and remodeling consistent with studies showing that synaptic mitochondria are more sensitive to Ca(2+) overload, oxidative stress, and ATP loss than non-synaptic mitochondria. The lead-induced decreases in QO(2) likely resulted from the decreased spherule cristae abundance and smaller cristae, perhaps due to Bax-mediated effects as they occurred in apoptotic rod inner segments. The increase in pedicle cristae abundance and CJ diameter could have resulted from increased Drp1-mediated fission, as small mitochondrial fragments were observed. The mechanisms of Bcl-xL-mediated remodeling might occur via interaction with formation of CJ protein 1 (Fcj1), whereas the partial protection of synaptic QO(2) might result from the enhanced efficiency of energy metabolism via Bcl-xL's direct interaction with the F1F0 ATP synthase and/or regulation of cellular redox status. These lead-induced alterations in photoreceptor synaptic terminal mitochondria likely underlie the persistent scotopic and mesopic deficits in lead-exposed children, workers, and experimental animals. Our findings stress the clinical and scientific importance of examining synaptic dysfunction following injury or disease during development, and developing therapeutic treatments that prevent synaptic

  20. The energetic state of mitochondria modulates complex III biogenesis through the ATP-dependent activity of Bcs1.

    Science.gov (United States)

    Ostojić, Jelena; Panozzo, Cristina; Lasserre, Jean-Paul; Nouet, Cécile; Courtin, Florence; Blancard, Corinne; di Rago, Jean-Paul; Dujardin, Geneviève

    2013-10-01

    Our understanding of the mechanisms involved in mitochondrial biogenesis has continuously expanded during the last decades, yet little is known about how they are modulated to optimize the functioning of mitochondria. Here, we show that mutations in the ATP binding domain of Bcs1, a chaperone involved in the assembly of complex III, can be rescued by mutations that decrease the ATP hydrolytic activity of the ATP synthase. Our results reveal a Bcs1-mediated control loop in which the biogenesis of complex III is modulated by the energy-transducing activity of mitochondria. Although ATP is well known as a regulator of a number of cellular activities, we show here that ATP can be also used to modulate the biogenesis of an enzyme by controlling a specific chaperone involved in its assembly. Our study further highlights the intramitochondrial adenine nucleotide pool as a potential target for the treatment of Bcs1-based disorders. Copyright © 2013 Elsevier Inc. All rights reserved.

  1. The oncolytic peptide LTX-315 induces cell death and DAMP release by mitochondria distortion in human melanoma cells

    Science.gov (United States)

    Eike, Liv-Marie; Yang, Nannan; Rekdal, Øystein; Sveinbjørnsson, Baldur

    2015-01-01

    Host defense peptides (HDPs) are naturally occurring molecules found in most species, in which they play a significant role in the first line defense against intruding pathogens, and several HDPs have been shown to possess anticancer activity. Structure-activity relationship studies on the HDP bovine lactoferricin revealed a de novo design of a nonamer peptide LTX-315, with oncolytic properties. In the present study, we investigated the oncolytic activity of LTX-315 in human melanoma cells (A375). LTX-315 induced a rapid plasma membrane disruption and cell death within 2 hours. At a low concentration, fluorescence-labeled LTX-315 was internalized and accumulated in cytoplasmic vacuoles in close proximity to the mitochondria. The mitochondrial membrane potential was shown to depolarize as a consequence of LTX-315 treatment and at ultrastructural level, the mitochondria morphology was significantly altered. Release of danger signals (DAMPs) such as ATP, Cytochrome C and HMGB1 into the cell supernatant of cultured cells was evident minutes after peptide treatment. The oncolytic effect of LTX-315 involving perturbation of both the cell membrane and the mitochondria with subsequent release of DAMPs may highlight the ability of LTX-315 to induce complete regression and long-term protective immune responses as previously reported in experimental animal models. PMID:26472184

  2. NDV-induced apoptosis in absence of Bax; evidence of involvement of apoptotic proteins upstream of mitochondria

    Directory of Open Access Journals (Sweden)

    Molouki Aidin

    2012-08-01

    Full Text Available Abstract Background Recently it was shown that following infection of HeLa cells with Newcastle disease virus (NDV, the matrix (M protein binds to Bax and subsequently the intrinsic pathway of apoptosis is activated. Moreover, there was very little alteration on mRNA and protein levels of Bax and Bcl-2 after infection with NDV. Finding In order to further investigate the role of members of the Bcl-2 family, Bax-knockout and wild-type HCT116 cells were infected with NDV strain AF2240. Although both cells underwent apoptosis through the activation of the intrinsic pathway and the release of cytochrome c from mitochondria, the percentage of dead Bax-knockout cells was significantly lower than wt cells (more than 10% at 48 h post-infection. In a parallel experiment, the effect of NDV on HT29 cells, that are originally Bcl-2-free, was studied. Apoptosis in HT29 cells was associated with Bax redistribution from cytoplasm to mitochondria, similar to that of HeLa and wt HCT116 cells. Conclusion Although the presence of Bax during NDV-induced apoptosis contributes to a faster cell death, it was concluded that other apoptotic protein(s upstream of mitochondria are also involved since cancer cells die whether in the presence or absence of Bax. Therefore, the classic Bax/Bcl-2 ratio may not be a major determinant in NDV-induced apoptosis.

  3. Non-thermal plasma induces mitochondria-mediated apoptotic signaling pathway via ROS generation in HeLa cells.

    Science.gov (United States)

    Li, Wei; Yu, K N; Ma, Jie; Shen, Jie; Cheng, Cheng; Zhou, Fangjian; Cai, Zhiming; Han, Wei

    2017-11-01

    Non-thermal plasma (NTP) has been proposed as a novel therapeutic method for anticancer treatment. Although increasing evidence suggests that NTP selectively induces apoptosis in some types of tumor cells, the molecular mechanisms underlying this phenomenon remain unclear. In this study, we further investigated possible molecular mechanisms for NTP-induced apoptosis of HeLa cells. The results showed that NTP exposure significantly inhibited the growth and viability of HeLa cells. Morphological observation and flow cytometry analysis demonstrated that NTP exposure induced HeLa cell apoptosis. NTP exposure also activated caspase-9 and caspase-3, which subsequently cleaved poly (ADP- ribose) polymerase. Furthermore, NTP exposure suppressed Bcl-2 expression, enhanced Bax expression and translocation to mitochondria, activated mitochondria-mediated apoptotic pathway, followed by the release of cytochrome c. Further studies showed that NTP treatment led to ROS generation, whereas blockade of ROS generation by N-acetyl-l-cysteine (NAC, ROS scavengers) significantly prevented NTP-induced mitochondrial alteration and subsequent apoptosis of HeLa cells via suppressing Bax translocation, cytochrome c and caspase-3 activation. Taken together, our results indicated that NTP exposure induced mitochondria-mediated intrinsic apoptosis of HeLa cells was activated by ROS generation. These findings provide insights to the therapeutic potential and clinical research of NTP as a novel tool in cervical cancer treatment. Copyright © 2017. Published by Elsevier Inc.

  4. Developing CNS mitochondria oxidative phosphorylation P/O/ADP/O index for rats

    International Nuclear Information System (INIS)

    Egana, E.; Diaz, G.

    1975-01-01

    The effect of whole-body-gamma irradiation on developing CNS mitochondria oxidative phosphorylation was studied through the P/O/ADP/O index; three irradiation doses (5, 50 and 500 R) were employed at neonatal stage and both 'prompt' (10 min approx,) and 'delayed' (7 days for 500 R exposure, 21 days for 5 and 50 R) effects were observed. In the 'prompt' effects investigated after 500 R exposure, the oxidative phosphorylation diminished; the same occurred at 7 days with this dose ('delayed' effect). With doses of 5 and 50 R there was no alteration of oxidative phosphorylation as a 'prompt' effect, but it diminished at 21 days post irradiation. The uncoupling between respiration and oxidative phosphorylation should explain - at least, in part -these results. (author)

  5. Developing CNS mitochondria oxidative phosphorylation P/O/ADP/O index for rats

    Energy Technology Data Exchange (ETDEWEB)

    Egana, E; Diaz, G [Institute of Experimental Medicine, Santiago (Chile). Lab. of Neurochemistry

    1975-11-01

    The effect of whole-body-gamma irradiation on developing CNS mitochondria oxidative phosphorylation was studied through the P/O/ADP/O index; three irradiation doses (5, 50 and 500 R) were employed at neonatal stage and both 'prompt' (10 min approx,) and 'delayed' (7 days for 500 R exposure, 21 days for 5 and 50 R) effects were observed. In the 'prompt' effects investigated after 500 R exposure, the oxidative phosphorylation diminished; the same occurred at 7 days with this dose ('delayed' effect). With doses of 5 and 50 R there was no alteration of oxidative phosphorylation as a 'prompt' effect, but it diminished at 21 days post irradiation. The uncoupling between respiration and oxidative phosphorylation should explain - at least, in part -these results.

  6. Mitochondria can Power Cells to Life and Death

    Indian Academy of Sciences (India)

    molecular basis of pathogenicity and ... Mitochondria were discovered by R Altman in 1890 and the word was coined ... Diabetes mellitus ... 2 x 103 per cell) depending upon where and in which tissue they exist. They can .... is released, which then gears up other types of caspases to orchestrate .... Cellular Biology, CDFD.

  7. Mitochondria and aging: innocent bystanders or guilty parties?

    Science.gov (United States)

    Tońska, K; Sołyga, A; Bartnik, E

    2009-01-01

    There are many theories of aging and a number of them encompass the role of mitochondria in this process. Mitochondrial DNA mutations and deletions have been shown to accumulate in many tissues in mammals during aging. However, there is little evidence that these mutations could affect the functioning of aging tissues.

  8. Atorvastatin affects negatively respiratory function of isolated endothelial mitochondria.

    Science.gov (United States)

    Broniarek, Izabela; Jarmuszkiewicz, Wieslawa

    2018-01-01

    The purpose of this research was to elucidate the direct effects of two popular blood cholesterol-lowering drugs used to treat cardiovascular diseases, atorvastatin and pravastatin, on respiratory function, membrane potential, and reactive oxygen species formation in mitochondria isolated from human umbilical vein endothelial cells (EA.hy926 cell line). Hydrophilic pravastatin did not significantly affect endothelial mitochondria function. In contrast, hydrophobic calcium-containing atorvastatin induced a loss of outer mitochondrial membrane integrity, an increase in hydrogen peroxide formation, and reductions in maximal (phosphorylating or uncoupled) respiratory rate, membrane potential and oxidative phosphorylation efficiency. The atorvastatin-induced changes indicate an impairment of mitochondrial function at the level of ATP synthesis and at the level of the respiratory chain, likely at complex I and complex III. The atorvastatin action on endothelial mitochondria was highly dependent on calcium ions and led to a disturbance in mitochondrial calcium homeostasis. Uptake of calcium ions included in atorvastatin molecule induced mitochondrial uncoupling that enhanced the inhibition of the mitochondrial respiratory chain by atorvastatin. Our results indicate that hydrophobic calcium-containing atorvastatin, widely used as anti-atherosclerotic agent, has a direct negative action on isolated endothelial mitochondria. Copyright © 2017. Published by Elsevier Inc.

  9. Phosphorylation of formate dehydrogenase in potato tuber mitochondria

    DEFF Research Database (Denmark)

    Bykova, N.V.; Stensballe, A.; Egsgaard, H.

    2003-01-01

    Two highly phosphorylated proteins were detected after two-dimensional (blue native/SDS-PAGE) gel electrophoretic separation of the matrix fraction isolated from potato tuber mitochondria. These two phosphoproteins were identified by mass spectrometry as formate dehydrogenase (FDH) and the E1alpha...

  10. Lupeol induces S-phase arrest and mitochondria-mediated ...

    Indian Academy of Sciences (India)

    48

    Lupeol induces S-phase arrest and mitochondria-mediated apoptosis in cervical cancer cells. Nupoor Prasad1, Akash Sabarwal2, Umesh C. S. Yadav1, Rana P. Singh2,*. 1School of Life Sciences, Central University of Gujarat, Gandhinagar, Gujarat, India. 2Cancer Biology Laboratory, School of Life Sciences, Jawaharlal ...

  11. Age-associated metabolic and morphologic changes in mitochondria of individual mouse and hamster oocytes.

    Directory of Open Access Journals (Sweden)

    Fatma Simsek-Duran

    Full Text Available BACKGROUND: In human oocytes, as in other mammalian ova, there is a significant variation in the pregnancy potential, with approximately 20% of oocyte-sperm meetings resulting in pregnancies. This frequency of successful fertilization decreases as the oocytes age. This low proportion of fruitful couplings appears to be influenced by changes in mitochondrial structure and function. In this study, we have examined mitochondrial biogenesis in both hamster (Mesocricetus auratus and mouse (Mus musculus ova as models for understanding the effects of aging on mitochondrial structure and energy production within the mammalian oocyte. METHODOLOGY/PRINCIPAL FINDINGS: Individual metaphase II oocytes from a total of 25 young and old mice and hamsters were collected from ovarian follicles after hormone stimulation and prepared for biochemical or structural analysis. Adenosine triphosphate levels and mitochondrial DNA number were determined within individual oocytes from young and old animals. In aged hamsters, oocyte adenosine triphosphate levels and mitochondrial DNA molecules were reduced 35.4% and 51.8%, respectively. Reductions of 38.4% and 44% in adenosine triphosphate and mitochondrial genomes, respectively, were also seen in aged mouse oocytes. Transmission electron microscopic (TEM analysis showed that aged rodent oocytes had significant alterations in mitochondrial and cytoplasmic lamellae structure. CONCLUSIONS/SIGNIFICANCE: In both mice and hamsters, decreased adenosine triphosphate in aged oocytes is correlated with a similar decrease in mtDNA molecules and number of mitochondria. Mitochondria in mice and hamsters undergo significant morphological change with aging including mitochondrial vacuolization, cristae alterations, and changes in cytoplasmic lamellae.

  12. Proteomics Analysis to Assess the Role of Mitochondria in BRCA1-Mediated Breast Tumorigenesis

    Directory of Open Access Journals (Sweden)

    Antonio Concolino

    2018-03-01

    Full Text Available Mitochondria are the organelles deputed to energy production, but they are also involved in carcinogenesis, cancer progression, and metastasis, playing a role in altered energy metabolism in cancer cells. Mitochondrial metabolism is connected with several mitochondrial pathways such as ROS signaling, Ca2+ homeostasis, mitophagy, and mitochondrial biogenesis. These pathways are merged in an interactive super-network that seems to play a crucial role in cancer. Germline mutations of the BRCA1 gene account for 5–10% of breast cancers and confer a risk of developing the disease 10- to 20-fold much higher than in non-carriers. By considering metabolic networks that could reconcile both genetic and non-genetic causal mechanisms in BRCA1 driven tumorigenesis, we herein based our study on the hypothesis that BRCA1 haploinsufficiency might drive metabolic rewiring in breast epithelial cells, acting as a push toward malignant transformation. Using 2D-DIGE we analyzed and compared the mitochondrial proteomic profile of sporadic breast cancer cell line (MCF7 and BRCA1 mutated breast cancer cell line (HCC1937. Image analysis was carried out with Decider Software, and proteins differentially expressed were identified by LC-MS/MS on a quadrupole-orbitrap mass spectrometer Q-Exactive. Ingenuity pathways analysis software was used to analyze the fifty-three mitochondrial proteins whose expression resulted significantly altered in response to BRCA1 mutation status. Mitochondrial Dysfunction and oxidative phosphorylation, and energy production and nucleic acid metabolism were, respectively, the canonical pathway and the molecular function mainly affected. Western blotting analysis was done to validate the expression and the peculiar mitochondrial compartmentalization of specific proteins such us HSP60 and HIF-1α. Particularly intriguing is the correlation between BRCA1 mutation status and HIF-1α localization into the mitochondria in a BRCA1 dependent manner

  13. Non-Targeted Metabolomics Analysis of Golden Retriever Muscular Dystrophy-Affected Muscles Reveals Alterations in Arginine and Proline Metabolism, and Elevations in Glutamic and Oleic Acid In Vivo

    Science.gov (United States)

    Abdullah, Muhammad; Kornegay, Joe N.; Honcoop, Aubree; Parry, Traci L.; Balog-Alvarez, Cynthia J.; Muehlbauer, Michael J.; Newgard, Christopher B.; Patterson, Cam

    2017-01-01

    Background: Like Duchenne muscular dystrophy (DMD), the Golden Retriever Muscular Dystrophy (GRMD) dog model of DMD is characterized by muscle necrosis, progressive paralysis, and pseudohypertrophy in specific skeletal muscles. This severe GRMD phenotype includes moderate atrophy of the biceps femoris (BF) as compared to unaffected normal dogs, while the long digital extensor (LDE), which functions to flex the tibiotarsal joint and serves as a digital extensor, undergoes the most pronounced atrophy. A recent microarray analysis of GRMD identified alterations in genes associated with lipid metabolism and energy production. Methods: We, therefore, undertook a non-targeted metabolomics analysis of the milder/earlier stage disease GRMD BF muscle versus the more severe/chronic LDE using GC-MS to identify underlying metabolic defects specific for affected GRMD skeletal muscle. Results: Untargeted metabolomics analysis of moderately-affected GRMD muscle (BF) identified eight significantly altered metabolites, including significantly decreased stearamide (0.23-fold of controls, p = 2.89 × 10−3), carnosine (0.40-fold of controls, p = 1.88 × 10−2), fumaric acid (0.40-fold of controls, p = 7.40 × 10−4), lactamide (0.33-fold of controls, p = 4.84 × 10−2), myoinositol-2-phosphate (0.45-fold of controls, p = 3.66 × 10−2), and significantly increased oleic acid (1.77-fold of controls, p = 9.27 × 10−2), glutamic acid (2.48-fold of controls, p = 2.63 × 10−2), and proline (1.73-fold of controls, p = 3.01 × 10−2). Pathway enrichment analysis identified significant enrichment for arginine/proline metabolism (p = 5.88 × 10−4, FDR 4.7 × 10−2), where alterations in L-glutamic acid, proline, and carnosine were found. Additionally, multiple Krebs cycle intermediates were significantly decreased (e.g., malic acid, fumaric acid, citric/isocitric acid, and succinic acid), suggesting that altered energy metabolism may be underlying the observed GRMD BF muscle

  14. Mitochondrial alterations in children with chronic liver disease ...

    African Journals Online (AJOL)

    Background: Over recent years it has become apparent that the hepatocyte mitochondrion functions both as a cause and as a target of liver injury. Resultant dysfunction of mitochondria yields deficient oxidative phosphorylation, increased generation of reactive oxygen species, impairment of other metabolic pathways and ...

  15. NSAIDs, Mitochondria and Calcium Signaling: Special Focus on Aspirin/Salicylates

    Directory of Open Access Journals (Sweden)

    Yoshihiro Suzuki

    2010-05-01

    Full Text Available Aspirin (acetylsalicylic acid is a well-known nonsteroidal anti-inflammatory drug (NSAID that has long been used as an anti-pyretic and analgesic drug. Recently, much attention has been paid to the chemopreventive and apoptosis-inducing effects of NSAIDs in cancer cells. These effects have been thought to be primarily attributed to the inhibition of cyclooxygenase activity and prostaglandin synthesis. However, recent studies have demonstrated unequivocally that certain NSAIDs, including aspirin and its metabolite salicylic acid, exert their anti-inflammatory and chemopreventive effects independently of cyclooxygenase activity and prostaglandin synthesis inhibition. It is becoming increasingly evident that two potential common targets of NSAIDs are mitochondria and the Ca2+ signaling pathway. In this review, we provide an overview of the current knowledge regarding the roles of mitochondria and Ca2+ in the apoptosis-inducing effects as well as some side effects of aspirin, salicylates and other NSAIDs, and introducing the emerging role of L-type Ca2+ channels, a new Ca2+ entry pathway in non-excitable cells that is up-regulated in human cancer cells.

  16. Generation of reactive oxygen species in the anterior eye segment. Synergistic codrugs of N-acetylcarnosine lubricant eye drops and mitochondria-targeted antioxidant act as a powerful therapeutic platform for the treatment of cataracts and primary open-angle glaucoma

    Directory of Open Access Journals (Sweden)

    Mark A. Babizhayev

    2016-12-01

    Mitochondrial targeting of compounds with universal types of antioxidant activity represents a promising approach for treating a number of ROS-related ocular diseases of the aging eye and can be implicated in the management of cataracts and primary open-angle glaucoma.

  17. Role of mitochondria in radiation sensitivity

    International Nuclear Information System (INIS)

    Indo, Hiroko; Tomita, Kazuo; Majima, Hideyuki; Matsui, Hirofumi; Ozawa, Toshihiko

    2007-01-01

    This paper describes mainly the role of mitochondrial (Mt) manganese superoxide dismutase (MnSOD) for deciding the radiation sensitivity of cells. The fact that Mt concerns with apoptosis has been shown by the finding that change in Mt membrane potential relates with the cell death. Mt has the electron transport system to yield the cellular energy molecule (ATP) and from which electrons are leaked out in 2-3%, a considerably large proportion in a cell. The electrons react with oxygen nearby to yield SO (O 2 ·- ), which in turn induces apoptosis through oxidation stress (OS). On the other hand, MnSOD is transported in Mt from cytoplasm and excludes the reactive oxygen species (ROS) like SO. Studies by MnSOD gene-deletion, knockout, cDNA-transfection, and transgenesis have indicated MnSOD is essential for keeping life and resistance to OS. Authors have shown that overexpression of Mt MnSOD protects against radiation-induced cell death, suggesting that Mt participates in radiation sensitivity where SO is involved. Interestingly, MnSOD activity is low in cancer cells, its overexpression results in tumor suppression and MnSOD is a target in leukemia therapy. When MTS (Mt targeting sequence, necessary for the enzyme to enter Mt)-deleted MnSOD is transfected, cells lack resistance to radiation, indicating the enzyme must be present in Mt. Mt DNA damage leading to electron transport system impairment is found to increase ROS, and to be reversed by the transfection of MnSOD gene. Studies of Mt DNA damage in cancer cells where aerobic glycolysis is actively operated, are currently in progress lively, and are thought to promote the development of diagnosis and treatment of cancer. (R.T.)

  18. Do the mitochondria of malaria parasites behave like the phoenix after return in the mosquito? Regeneration of degenerated mitochondria is required for successful Plasmodium infection.

    Science.gov (United States)

    Bongaerts, Ger

    2005-01-01

    Mitochondria are energy generators in eukaryotic organisms like man and the pathogenic malaria parasites, the Plasmodium spp. From the moment a mosquito-mediated malaria infection occurs in man the parasite multiplies profusely, but eventually the oxygen supply becomes the limiting factor in this process. Consequently, the parasite will increasingly generate energy (and lactic acid) from sugar fermentation. Simultaneously, the cristate structure of Plasmodium mitochondria degenerates and becomes acristate. The degenerated acristate mitochondria of mammalian Plasmodium parasites seem to be able to revitalise by transforming to cristate mitochondria inside the oxygen-rich mosquito, like the rebirth of the old phoenix. In this way the infectivity of the parasite is revitalised.

  19. Melatonin: A Mitochondrial Targeting Molecule Involving Mitochondrial Protection and Dynamics

    Science.gov (United States)

    Tan, Dun-Xian; Manchester, Lucien C.; Qin, Lilan; Reiter, Russel J.

    2016-01-01

    Melatonin has been speculated to be mainly synthesized by mitochondria. This speculation is supported by the recent discovery that aralkylamine N-acetyltransferase/serotonin N-acetyltransferase (AANAT/SNAT) is localized in mitochondria of oocytes and the isolated mitochondria generate melatonin. We have also speculated that melatonin is a mitochondria-targeted antioxidant. It accumulates in mitochondria with high concentration against a concentration gradient. This is probably achieved by an active transportation via mitochondrial melatonin transporter(s). Melatonin protects mitochondria by scavenging reactive oxygen species (ROS), inhibiting the mitochondrial permeability transition pore (MPTP), and activating uncoupling proteins (UCPs). Thus, melatonin maintains the optimal mitochondrial membrane potential and preserves mitochondrial functions. In addition, mitochondrial biogenesis and dynamics is also regulated by melatonin. In most cases, melatonin reduces mitochondrial fission and elevates their fusion. Mitochondrial dynamics exhibit an oscillatory pattern which matches the melatonin circadian secretory rhythm in pinealeocytes and probably in other cells. Recently, melatonin has been found to promote mitophagy and improve homeostasis of mitochondria. PMID:27999288

  20. Nicotinamide nucleotide transhydrogenase (Nnt) links the substrate requirement in brain mitochondria for hydrogen peroxide removal to the thioredoxin/peroxiredoxin (Trx/Prx) system.

    Science.gov (United States)

    Lopert, Pamela; Patel, Manisha

    2014-05-30

    Mitochondrial reactive oxygen species are implicated in the etiology of multiple neurodegenerative diseases, including Parkinson disease. Mitochondria are known to be net producers of ROS, but recently we have shown that brain mitochondria can consume mitochondrial hydrogen peroxide (H2O2) in a respiration-dependent manner predominantly by the thioredoxin/peroxiredoxin system. Here, we sought to determine the mechanism linking mitochondrial respiration with H2O2 catabolism in brain mitochondria and dopaminergic cells. We hypothesized that nicotinamide nucleotide transhydrogenase (Nnt), which utilizes the proton gradient to generate NADPH from NADH and NADP(+), provides the link between mitochondrial respiration and H2O2 detoxification through the thioredoxin/peroxiredoxin system. Pharmacological inhibition of Nnt in isolated brain mitochondria significantly decreased their ability to consume H2O2 in the presence, but not absence, of respiration substrates. Nnt inhibition in liver mitochondria, which do not require substrates to detoxify H2O2, had no effect. Pharmacological inhibition or lentiviral knockdown of Nnt in N27 dopaminergic cells (a) decreased H2O2 catabolism, (b) decreased NADPH and increased NADP(+) levels, and (c) decreased basal, spare, and maximal mitochondrial oxygen consumption rates. Nnt-deficient cells possessed higher levels of oxidized mitochondrial Prx, which rendered them more susceptible to steady-state increases in H2O2 and cell death following exposure to subtoxic levels of paraquat. These data implicate Nnt as the critical link between the metabolic and H2O2 antioxidant function in brain mitochondria and suggests Nnt as a potential therapeutic target to improve the redox balance in conditions of oxidative stress associated with neurodegenerative diseases. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

  1. Ketogenic diets, mitochondria, and neurological diseases

    Science.gov (United States)

    Gano, Lindsey B.; Patel, Manisha; Rho, Jong M.

    2014-01-01

    The ketogenic diet (KD) is a broad-spectrum therapy for medically intractable epilepsy and is receiving growing attention as a potential treatment for neurological disorders arising in part from bioenergetic dysregulation. The high-fat/low-carbohydrate “classic KD”, as well as dietary variations such as the medium-chain triglyceride diet, the modified Atkins diet, the low-glycemic index treatment, and caloric restriction, enhance cellular metabolic and mitochondrial function. Hence, the broad neuroprotective properties of such therapies may stem from improved cellular metabolism. Data from clinical and preclinical studies indicate that these diets restrict glycolysis and increase fatty acid oxidation, actions which result in ketosis, replenishment of the TCA cycle (i.e., anaplerosis), restoration of neurotransmitter and ion channel function, and enhanced mitochondrial respiration. Further, there is mounting evidence that the KD and its variants can impact key signaling pathways that evolved to sense the energetic state of the cell, and that help maintain cellular homeostasis. These pathways, which include PPARs, AMP-activated kinase, mammalian target of rapamycin, and the sirtuins, have all been recently implicated in the neuroprotective effects of the KD. Further research in this area may lead to future therapeutic strategies aimed at mimicking the pleiotropic neuroprotective effects of the KD. PMID:24847102

  2. Mitochondria in the spotlight of aging and idiopathic pulmonary fibrosis

    Science.gov (United States)

    Mora, Ana L.; Rojas, Mauricio

    2017-01-01

    Idiopathic pulmonary fibrosis (IPF) is a chronic age-related lung disease with high mortality that is characterized by abnormal scarring of the lung parenchyma. There has been a recent attempt to define the age-associated changes predisposing individuals to develop IPF. Age-related perturbations that are increasingly found in epithelial cells and fibroblasts from IPF lungs compared with age-matched cells from normal lungs include defective autophagy, telomere attrition, altered proteostasis, and cell senescence. These divergent processes seem to converge in mitochondrial dysfunction and metabolic distress, which potentiate maladaptation to stress and susceptibility to age-related diseases such as IPF. Therapeutic approaches that target aging processes may be beneficial for halting the progression of disease and improving quality of life in IPF patients. PMID:28145905

  3. Hydrophobic analogues of rhodamine B and rhodamine 101: potent fluorescent probes of mitochondria in living C. elegans

    Directory of Open Access Journals (Sweden)

    Laurie F. Mottram

    2012-12-01

    Full Text Available Mitochondria undergo dynamic fusion and fission events that affect the structure and function of these critical energy-producing cellular organelles. Defects in these dynamic processes have been implicated in a wide range of human diseases including ischemia, neurodegeneration, metabolic disease, and cancer. To provide new tools for imaging of mitochondria in vivo, we synthesized novel hydrophobic analogues of the red fluorescent dyes rhodamine B and rhodamine 101 that replace the carboxylate with a methyl group. Compared to the parent compounds, methyl analogues termed HRB and HR101 exhibit slightly red-shifted absorbance and emission spectra (5–9 nm, modest reductions in molar extinction coefficent and quantum yield, and enhanced partitioning into octanol compared with aqueous buffer of 10-fold or more. Comparison of living C. elegans (nematode roundworm animals treated with the classic fluorescent mitochondrial stains rhodamine 123, rhodamine 6G, and rhodamine B, as well as the structurally related fluorophores rhodamine 101, and basic violet 11, revealed that HRB and HR101 are the most potent mitochondrial probes, enabling imaging of mitochondrial motility, fusion, and fission in the germline and other tissues by confocal laser scanning microscopy after treatment for 2 h at concentrations as low as 100 picomolar. Because transgenes are poorly expressed in the germline of these animals, these small molecules represent superior tools for labeling dynamic mitochondria in this tissue compared with the expression of mitochondria-targeted fluorescent proteins. The high bioavailabilty of these novel fluorescent probes may facilitate the identification of agents and factors that affect diverse aspects of mitochondrial biology in vivo.

  4. Evidence for loss of mitochondria in Microsporidia from a mitochondrial-type HSP70 in Nosema locustae.

    Science.gov (United States)

    Germot, A; Philippe, H; Le Guyader, H

    1997-08-01

    In molecular phylogenies based on ribosomal RNA, three amitochondriate protist lineages, Microsporidia, Metamonada (including diplomonads) and Parabasala (including trichomonads), are the earliest offshoots of the eukaryotic tree. As an explantation for the lack of mitochondria in these organisms, the hypothesis that they have diverged before the mitochondrial endosymbiosis is preferred to the less parsimonious hypothesis of several independent losses of the organelle. Nevertheless, if they had descended from mitochondrion-containing ancestors, it may be possible to find in their nuclear DNA genes that derive from the endosymbiont which gave rise to mitochondria. Based on similar evidence, secondary losses of mitochondria have recently been suggested for Entamoeba histolytica and for Trichomonas vaginalis. In this study, we have isolated a gene encoding a chaperone protein (HSP70, 70 kDa heat shock protein) from the microspordian Nosema locustae. In phylogenetic trees, this HSP70 was located within a group of sequences that in other lineages is targetted to the mitochondrial compartment, itself included in the proteobacterial clade. In addition, the N. locustae protein contained the GDAW(V) motif shared by mitochondrial and proteobacterial sequences, with only one conservative substitution. Moreover, microsporidia, a phylum which was assumed to emerge close to the base of the eukaryotic tree, appears as the sister-group of fungi in the HSP70 phylogeny, in agreement with some ultrastructural characters and phylogenies based on alpha- and beta-tubulins. Loss of mitochondria, now demonstrated for several amitochondriate groups, indicates that the common ancestor of all the extant eukaryotic species could have been a mitochondriate eukaryote.

  5. [Acetylcholine activation of alpha-ketoglutarate oxidation in liver mitochondria].

    Science.gov (United States)

    Shostakovskaia, I V; Doliba, N M; Gordiĭ, S K; Babskiĭ, A M; Kondrashova, M N

    1986-01-01

    Activation of alpha-ketoglutarate oxidation in the rat liver mitochondria takes place 15 and 30 min after intraperitoneal injection of acetyl choline. This mediator in doses of 25, 50 and 100 micrograms per 100 g of body weight causes a pronounced stimulation of phosphorylation respiration rate and calcium capacity of mitochondria with alpha-ketoglutarate oxidation. Acetyl choline is found to have a moderate inhibitory action on oxidation of lower (physiological) concentrations of succinate. Its stimulating action on alpha-ketoglutarate oxidation is associated with activation of M-cholinoreceptors; atropine, a choline-blocker, removes completely this effect. It is supposed that alpha-ketoglutarate and succinate are included into the composition of two reciprocal hormonal-substrate nucleotide systems.

  6. Membrane potential of mitochondria from the liver of irradiated rats

    International Nuclear Information System (INIS)

    Fomenko, B.S.; Kaminin, A.N.; Elfimova, I.A.; Akoev, I.G.

    1977-01-01

    Measurements of the membrane potential of rat liver mitochondria 1 hour after irradiation with 800 R dose showed a decrease of its value. The potential decreased against the background of the activation of the generating mechanisms (the electron transport chain and ATP-ases). During energization of the membranes by the electron transport chain similar effect has been observed with different oxidation substrates (NAD linked substrates and succinate). It suggests that similar causative factors are at the basis of the changes observed. It is quite possible that the increase in the rate of both mitochondria respiration and ATP hydrolysis after the irradiation of animals was a consequence of the radiation-induced decrease in the potential value. (author)

  7. The role of mitochondria in yeast programmed cell death

    International Nuclear Information System (INIS)

    Guaragnella, Nicoletta; Ždralević, Maša; Antonacci, Lucia; Passarella, Salvatore; Marra, Ersilia; Giannattasio, Sergio

    2012-01-01

    Mammalian apoptosis and yeast programmed cell death (PCD) share a variety of features including reactive oxygen species production, protease activity and a major role played by mitochondria. In view of this, and of the distinctive characteristics differentiating yeast and multicellular organism PCD, the mitochondrial contribution to cell death in the genetically tractable yeast Saccharomyces cerevisiae has been intensively investigated. In this mini-review we report whether and how yeast mitochondrial function and proteins belonging to oxidative phosphorylation, protein trafficking into and out of mitochondria, and mitochondrial dynamics, play a role in PCD. Since in PCD many processes take place over time, emphasis will be placed on an experimental model based on acetic acid-induced PCD (AA-PCD) which has the unique feature of having been investigated as a function of time. As will be described there are at least two AA-PCD pathways each with a multifaceted role played by mitochondrial components, in particular by cytochrome c.

  8. The dynamic regulation of NAD metabolism in mitochondria

    Science.gov (United States)

    Stein, Liana Roberts; Imai, Shin-ichiro

    2012-01-01

    Mitochondria are intracellular powerhouses that produce ATP and carry out diverse functions for cellular energy metabolism. While the maintenance of an optimal NAD/NADH ratio is essential for mitochondrial function, it has recently become apparent that the maintenance of the mitochondrial NAD pool also has critical importance. The biosynthesis, transport, and catabolism of NAD and its key intermediates play an important role in the regulation of NAD-consuming mediators, such as sirtuins, poly-ADP-ribose polymerases, and CD38/157 ectoenzymes, in intra- and extracellular compartments. Mitochondrial NAD biosynthesis is also modulated in response to nutritional and environmental stimuli. In this article, we discuss this dynamic regulation of NAD metabolism in mitochondria to shed light on the intimate connection between NAD and mitochondrial function. PMID:22819213

  9. ANGULAR LIGHT-SCATTERING STUDIES ON ISOLATED MITOCHONDRIA

    Science.gov (United States)

    Gotterer, Gerald S.; Thompson, Thomas E.; Lehninger, Albert L.

    1961-01-01

    Angular light-scattering studies have been carried out on suspensions of isolated rat liver mitochondria. The angular scatter pattern has a large forward component, typical of large particles. Changes in dissymmetry and in the intensity of light scattered at 90° have been correlated with changes in optical density during the course of mitochondrial swelling and contraction. Such changes can be measured at mitochondrial concentrations much below those required for optical density measurements. Changes in mitochondrial geometry caused by factors "leaking" from mitochondria, not detectable by optical density measurements, have been demonstrated by measuring changes in dissymmetry. Angular light-scattering measurements therefore offer the advantages of increased sensitivity and of added indices of changes in mitochondrial conformation. PMID:19866589

  10. Mitochondria: role of citrulline and arginine supplementation in MELAS syndrome.

    Science.gov (United States)

    El-Hattab, Ayman W; Emrick, Lisa T; Chanprasert, Sirisak; Craigen, William J; Scaglia, Fernando

    2014-03-01

    Mitochondria are found in all nucleated human cells and generate most of the cellular energy. Mitochondrial disorders result from dysfunctional mitochondria that are unable to generate sufficient ATP to meet the energy needs of various organs. Mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS) syndrome is a frequent maternally inherited mitochondrial disorder. There is growing evidence that nitric oxide (NO) deficiency occurs in MELAS syndrome and results in impaired blood perfusion that contributes significantly to several complications including stroke-like episodes, myopathy, and lactic acidosis. Both arginine and citrulline act as NO precursors and their administration results in increased NO production and hence can potentially have therapeutic utility in MELAS syndrome. Citrulline raises NO production to a greater extent than arginine, therefore, citrulline may have a better therapeutic effect. Controlled studies assessing the effects of arginine or citrulline supplementation on different clinical aspects of MELAS syndrome are needed. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Mitocans: Mitochondrial targeted anti-cancer drugs as improved therapies and related patent documents

    Czech Academy of Sciences Publication Activity Database

    Ralph, S.J.; Low, P.; Dong, L.; Lawen, A.; Neužil, Jiří

    2006-01-01

    Roč. 1, - (2006), s. 327-346 ISSN 1574-8928 Institutional research plan: CEZ:AV0Z50520514 Keywords : mitocans * vitamin E analogues * mitochondria-based targeting Subject RIV: EB - Genetics ; Molecular Biology

  12. The rapid mode of calcium uptake into heart mitochondria (RaM): comparison to RaM in liver mitochondria.

    Science.gov (United States)

    Buntinas, L; Gunter, K K; Sparagna, G C; Gunter, T E

    2001-04-02

    A mechanism of Ca(2+) uptake, capable of sequestering significant amounts of Ca(2+) from cytosolic Ca(2+) pulses, has previously been identified in liver mitochondria. This mechanism, the Rapid Mode of Ca(2+) uptake (RaM), was shown to sequester Ca(2+) very rapidly at the beginning of each pulse in a sequence [Sparagna et al. (1995) J. Biol. Chem. 270, 27510-27515]. The existence and properties of RaM in heart mitochondria, however, are unknown and are the basis for this study. We show that RaM functions in heart mitochondria with some of the characteristics of RaM in liver, but its activation and inhibition are quite different. It is feasible that these differences represent different physiological adaptations in these two tissues. In both tissues, RaM is highly conductive at the beginning of a Ca(2+) pulse, but is inhibited by the rising [Ca(2+)] of the pulse itself. In heart mitochondria, the time required at low [Ca(2+)] to reestablish high Ca(2+) conductivity via RaM i.e. the 'resetting time' of RaM is much longer than in liver. RaM in liver mitochondria is strongly activated by spermine, activated by ATP or GTP and unaffected by ADP and AMP. In heart, RaM is activated much less strongly by spermine and unaffected by ATP or GTP. RaM in heart is strongly inhibited by AMP and has a biphasic response to ADP; it is activated at low concentrations and inhibited at high concentrations. Finally, an hypothesis consistent with the data and characteristics of liver and heart is presented to explain how RaM may function to control the rate of oxidative phosphorylation in each tissue. Under this hypothesis, RaM functions to create a brief, high free Ca(2+) concentration inside mitochondria which may activate intramitochondrial metabolic reactions with relatively small amounts of Ca(2+) uptake. This hypothesis is consistent with the view that intramitochondrial [Ca(2+)] may be used to control the rate of ADP phosphorylation in such a way as to minimize the probability of

  13. Mitochondria as determinant of nucleotide pools and chromosomal stability

    DEFF Research Database (Denmark)

    Madsen, Claus Desler; Munch-Petersen, Birgitte; Stevnsner, Tinna

    2007-01-01

    Mitochondrial function plays an important role in multiple human diseases and mutations in the mitochondrial genome have been detected in nearly every type of cancer investigated to date. However, the mechanism underlying the interrelation is unknown. We used human cell lines depleted of mitochon...... mitochondrial activity. Our results suggest that mitochondria are central players in maintaining genomic stability and in controlling essential nuclear processes such as upholding a balanced supply of nucleotides....

  14. Functional Mitochondria Are Important for the Effect of Resveratrol

    DEFF Research Database (Denmark)

    Widlund, Anne Lykkegaard; Baral, Kaushal; Dalgaard, Louise Torp

    2017-01-01

    Resveratrol (Resv) is a polyphenol reported to modulate mitochondrial activity. The aim was to use HeLa and 143B cells to characterize the action of Resv on mitochondrial activity, cell size and proliferation using wild type (WT) and Rho 0 cells deficient in mitochondrial DNA. In both HeLa WT and......, but not in Rho 0 when treated with Resv. Overall, the findings presented indicate that functional mitochondria are a prerequisite for cell enlargement by Resv....

  15. Mitochondria: An Organelle of Bacterial Origin Controlling Inflammation

    Directory of Open Access Journals (Sweden)

    Alain Meyer

    2018-04-01

    Full Text Available Inflammation is a cellular and molecular response to infection and/or tissues injury. While a suited inflammatory response in intensity and time allows for killing pathogens, clearing necrotic tissue, and healing injury; an excessive inflammatory response drives various diseases in which inflammation and tissues damages/stress self-sustain each other. Microbes have been poorly implied in non-resolving inflammation, emphasizing the importance of endogenous regulation of inflammation. Mitochondria have been historically identified as the main source of cellular energy, by coupling the oxidation of fatty acids and pyruvate with the production of high amount of adenosine triphosphate by the electron transport chain. Mitochondria are also the main source of reactive oxygen species. Interestingly, research in the last decade has highlighted that since its integration in eukaryote cells, this organelle of bacterial origin has not only been tolerated by immunity, but has also been placed as a central regulator of cell defense. In intact cells, mitochondria regulate cell responses to critical innate immune receptors engagement. Downstream intracellular signaling pathways interact with mitochondrial proteins and are tuned by mitochondrial functioning. Moreover, upon cell stress or damages, mitochondrial components are released into the cytoplasm or the extra cellular milieu, where they act as danger signals when recognized by innate immune receptors. Finally, by regulating the energetic state of immunological synapse between dendritic cells and lymphocytes, mitochondria regulate the inflammation fate toward immunotolerance or immunogenicity. As dysregulations of these processes have been recently involved in various diseases, the identification of the underlying mechanisms might open new avenues to modulate inflammation.

  16. Capsaicin binds to prohibitin 2 and displaces it from the mitochondria to the nucleus

    International Nuclear Information System (INIS)

    Kuramori, Chikanori; Azuma, Motoki; Kume, Kanako; Kaneko, Yuki; Inoue, Atsushi; Yamaguchi, Yuki; Kabe, Yasuaki; Hosoya, Takamitsu; Kizaki, Masahiro; Suematsu, Makoto; Handa, Hiroshi

    2009-01-01

    Capsaicin is widely used as a food additive and as an analgesic agent. Besides its well-known role in nociception, which is mediated by vanilloid receptor 1 specifically expressed in dorsal root ganglion neurons, capsaicin has also been considered as a potential anticancer agent, as it inhibits cell proliferation and induces apoptosis in various types of cancer cells. Here we identified a new molecular target of capsaicin from human myeloid leukemia cells. We show that capsaicin binds to prohibitin (PHB) 2, which is normally localized to the inner mitochondrial membrane, and induces its translocation to the nucleus. PHB2 is implicated in the maintenance of mitochondrial morphology and the control of apoptosis. We also provide evidence suggesting that capsaicin causes apoptosis directly through the mitochondria and that PHB2 contributes to capsaicin-induced apoptosis at multiple levels. This work will serve as an important foundation for further understanding of anticancer activity of capsaicin.

  17. The Injury and Therapy of Reactive Oxygen Species in Intracerebral Hemorrhage Looking at Mitochondria

    Directory of Open Access Journals (Sweden)

    Jie Qu

    2016-01-01

    Full Text Available Intracerebral hemorrhage is an emerging major health problem often resulting in death or disability. Reactive oxygen species (ROS have been identified as one of the major damaging factors in ischemic stroke. However, there is less discussion about ROS in hemorrhage stroke. Metabolic products of hemoglobin, excitatory amino acids, and inflammatory cells are all sources of ROS, and ROS harm the central nervous system through cell death and structural damage, especially disruption of the blood-brain barrier. We have considered the antioxidant system of the CNS itself and the drugs aiming to decrease ROS after ICH, and we find that mitochondria are key players in all of these aspects. Moreover, when the mitochondrial permeability transition pore opens, ROS-induced ROS release, which leads to extensive liberation of ROS and mitochondrial failure, occurs. Therefore, the mitochondrion may be a significant target for elucidating the problem of ROS in ICH; however, additional experimental support is required.

  18. Viral degradasome hijacks mitochondria to suppress innate immunity

    Science.gov (United States)

    Goswami, Ramansu; Majumdar, Tanmay; Dhar, Jayeeta; Chattopadhyay, Saurabh; Bandyopadhyay, Sudip K; Verbovetskaya, Valentina; Sen, Ganes C; Barik, Sailen

    2013-01-01

    The balance between the innate immunity of the host and the ability of a pathogen to evade it strongly influences pathogenesis and virulence. The two nonstructural (NS) proteins, NS1 and NS2, of respiratory syncytial virus (RSV) are critically required for RSV virulence. Together, they strongly suppress the type I interferon (IFN)-mediated innate immunity of the host cells by degrading or inhibiting multiple cellular factors required for either IFN induction or response pathways, including RIG-I, IRF3, IRF7, TBK1 and STAT2. Here, we provide evidence for the existence of a large and heterogeneous degradative complex assembled by the NS proteins, which we named “NS-degradasome” (NSD). The NSD is roughly ∼300-750 kD in size, and its degradative activity was enhanced by the addition of purified mitochondria in vitro. Inside the cell, the majority of the NS proteins and the substrates of the NSD translocated to the mitochondria upon RSV infection. Genetic and pharmacological evidence shows that optimal suppression of innate immunity requires mitochondrial MAVS and mitochondrial motility. Together, we propose a novel paradigm in which the mitochondria, known to be important for the innate immune activation of the host, are also important for viral suppression of the innate immunity. PMID:23877405

  19. Identification of nitric oxide in mitochondria of myometrium cell

    Directory of Open Access Journals (Sweden)

    Danylovych Yu. V.

    2015-06-01

    Full Text Available Aim. To demonstrate the possibility of NO synthesis in intact myocytes of uterus. Methods. Confocal scanning microscopy method, NO-sensitive fluorescent probe DAF-FM, MitoTracker Orange CM-H2TMRos. Results. The basal production of NO in intact myocytes was shown using DAF-FM. Incubation of myocytes with NO donor – sodium nitroprusside (SNP – led to an increase of the DAF-FM-T fluorescent signal. On the contrary, the addition of NO-synthase inhibitor – N-nitro-L-arginine (NA – results in the reduction of fluorescent intensity. It was demonstrated colocalizition of specific probe for mitochondria MitoTracker Orange CM-H2TMRos and NO-sensitive dye DAF-FM. Conclusions. For the first time it has been demonstrated the presence of NO in smooth muscle cell mitochondria using laser confocal microscopy, NO-sensitive probe DAF-FM and specific marker of the functionally active mitochondria MitoTracker Orange CM-H2TMRos.

  20. Placentome Nutrient Transporters and Mammalian Target of Rapamycin Signaling Proteins Are Altered by the Methionine Supply during Late Gestation in Dairy Cows and Are Associated with Newborn Birth Weight.

    Science.gov (United States)

    Batistel, Fernanda; Alharthi, Abdulrahman Sm; Wang, Ling; Parys, Claudia; Pan, Yuan-Xiang; Cardoso, Felipe C; Loor, Juan J

    2017-09-01

    Background: To our knowledge, most research demonstrating a link between maternal nutrition and both fetal growth and offspring development after birth has been performed with nonruminants. Whether such relationships exist in large ruminants is largely unknown. Objective: We aimed to investigate whether increasing the methionine supply during late pregnancy would alter uteroplacental tissue nutrient transporters and mammalian target of rapamycin (mTOR) and their relation with newborn body weight. Methods: Multiparous Holstein cows were used in a randomized complete block design experiment. During the last 28 d of pregnancy, cows were fed a control diet or the control diet plus ethylcellulose rumen-protected methionine (0.9 g/kg dry matter intake) (Mepron; Evonik Nutrition & Care GmbH) to achieve a 2.8:1 ratio of lysine to methionine in the metabolizable protein reaching the small intestine. We collected placentome samples at parturition and used them to assess mRNA and protein expression and the phosphorylation status of mTOR pathway proteins. Results: Newborn body weight was greater in the methionine group than in the control group (44.1 kg and 41.8 kg, respectively; P ≤ 0.05). Increasing the methionine supply also resulted in greater feed intake (15.8 kg/d and 14.6 kg/d), plasma methionine (11.9 μM and 15.3 μM), and plasma insulin (1.16 μg/L and 0.81 μg/L) in cows during late pregnancy. As a result, mRNA expression of genes involved in neutral amino acid transport [solute carrier (SLC) family members SLC3A2 , SLC7A5 , SLC38A1 , and SLC38A10 ], glucose transport [ SLC2A1 , SLC2A3 , and SLC2A4 ], and the mTOR pathway [mechanistic target of rapamycin and ribosomal protein S6 kinase B1] were upregulated ( P ≤ 0.07) in methionine-supplemented cows. Among 6 proteins in the mTOR pathway, increasing the methionine supply led to greater ( P ≤ 0.09) protein expression of α serine-threonine kinase (AKT), phosphorylated (p)-AKT, p-eukaryotic elongation factor 2

  1. An antimicrobial peptidomimetic induces Mucorales cell death through mitochondria-mediated apoptosis.

    Directory of Open Access Journals (Sweden)

    E Magda Barbu

    Full Text Available The incidence of mucormycosis has dramatically increased in immunocompromised patients. Moreover, the array of cellular targets whose inhibition results in fungal cell death is rather limited. Mitochondria have been mechanistically identified as central regulators of detoxification and virulence in fungi. Our group has previously designed and developed a proteolytically-resistant peptidomimetic motif D(KLAKLAK2 with pleiotropic action ranging from targeted (i.e., ligand-directed activity against cancer and obesity to non-targeted activity against antibiotic resistant gram-negative rods. Here we evaluated whether this non-targeted peptidomimetic motif is active against Mucorales. We show that D(KLAKLAK2 has marked fungicidal action, inhibits germination, and reduces hyphal viability. We have also observed cellular changes characteristic of apoptosis in D(KLAKLAK2-treated Mucorales cells. Moreover, the fungicidal activity was directly correlated with vacuolar injury, mitochondrial swelling and mitochondrial membrane depolarization, intracellular reactive oxygen species accumulation (ROS, and increased caspase-like enzymatic activity. Finally, these apoptotic features were prevented by the addition of the ROS scavenger N-acetyl-cysteine indicating mechanistic pathway specificity. Together, these findings indicate that D(KLAKLAK2 makes Mucorales exquisitely susceptible via mitochondrial injury-induced apoptosis. This prototype may serve as a candidate drug for the development of translational applications against mucormycosis and perhaps other fungal infections.

  2. An antimicrobial peptidomimetic induces Mucorales cell death through mitochondria-mediated apoptosis.

    Science.gov (United States)

    Barbu, E Magda; Shirazi, Fazal; McGrath, Danielle M; Albert, Nathaniel; Sidman, Richard L; Pasqualini, Renata; Arap, Wadih; Kontoyiannis, Dimitrios P

    2013-01-01

    The incidence of mucormycosis has dramatically increased in immunocompromised patients. Moreover, the array of cellular targets whose inhibition results in fungal cell death is rather limited. Mitochondria have been mechanistically identified as central regulators of detoxification and virulence in fungi. Our group has previously designed and developed a proteolytically-resistant peptidomimetic motif D(KLAKLAK)2 with pleiotropic action ranging from targeted (i.e., ligand-directed) activity against cancer and obesity to non-targeted activity against antibiotic resistant gram-negative rods. Here we evaluated whether this non-targeted peptidomimetic motif is active against Mucorales. We show that D(KLAKLAK)2 has marked fungicidal action, inhibits germination, and reduces hyphal viability. We have also observed cellular changes characteristic of apoptosis in D(KLAKLAK)2-treated Mucorales cells. Moreover, the fungicidal activity was directly correlated with vacuolar injury, mitochondrial swelling and mitochondrial membrane depolarization, intracellular reactive oxygen species accumulation (ROS), and increased caspase-like enzymatic activity. Finally, these apoptotic features were prevented by the addition of the ROS scavenger N-acetyl-cysteine indicating mechanistic pathway specificity. Together, these findings indicate that D(KLAKLAK)2 makes Mucorales exquisitely susceptible via mitochondrial injury-induced apoptosis. This prototype may serve as a candidate drug for the development of translational applications against mucormycosis and perhaps other fungal infections.

  3. Effects of Aluminium on Rat Brain Mitochondria Bioenergetics: an In vitro and In vivo Study.

    Science.gov (United States)

    Iglesias-González, Javier; Sánchez-Iglesias, Sofía; Beiras-Iglesias, Andrés; Méndez-Álvarez, Estefanía; Soto-Otero, Ramón

    2017-01-01

    Numerous studies have highlighted the potential of aluminium as an aetiological factor for some neurodegenerative disorders, particularly Alzheimer's disease and Parkinson's disease. Our previous studies have shown that aluminium can cause oxidative stress, reduce the activity of some antioxidant enzymes, and enhance the dopaminergic neurodegeneration induced by 6-hydroxydopamine in an experimental model of Parkinson's disease in rats. We now report a study on the effects caused by aluminium on mitochondrial bioenergetics following aluminium addition and after its chronic administration to rats. To develop our study, we used a high-resolution respirometry to test the mitochondrial respiratory capacities under the conditions of coupling, uncoupling, and non-coupling. Our study showed alterations in leakiness, a reduction in the maximum capacity of complex II-linked respiratory pathway, a decline in the respiration efficiency, and a decrease in the activities of complexes III and V in both models studied. The observed effects also included both an alteration in mitochondrial transmembrane potential and a decrease in oxidative phosphorylation capacity when relatively high concentrations of aluminium were added to the isolated mitochondria. These findings contribute to explain both the ability of aluminium to generate oxidative stress and its suggested potential to act as an etiological factor by promoting the progression of neurodegenerative disorders such as Parkinson's disease.

  4. NIF-type iron-sulfur cluster assembly system is duplicated and distributed in the mitochondria and cytosol of Mastigamoeba balamuthi.

    Science.gov (United States)

    Nývltová, Eva; Šuták, Robert; Harant, Karel; Šedinová, Miroslava; Hrdy, Ivan; Paces, Jan; Vlček, Čestmír; Tachezy, Jan

    2013-04-30

    In most eukaryotes, the mitochondrion is the main organelle for the formation of iron-sulfur (FeS) clusters. This function is mediated through the iron-sulfur cluster assembly machinery, which was inherited from the α-proteobacterial ancestor of mitochondria. In Archamoebae, including pathogenic Entamoeba histolytica and free-living Mastigamoeba balamuthi, the complex iron-sulfur cluster machinery has been replaced by an ε-proteobacterial nitrogen fixation (NIF) system consisting of two components: NifS (cysteine desulfurase) and NifU (scaffold protein). However, the cellular localization of the NIF system and the involvement of mitochondria in archamoebal FeS assembly are controversial. Here, we show that the genes for both NIF components are duplicated within the M. balamuthi genome. One paralog of each protein contains an amino-terminal extension that targets proteins to mitochondria (NifS-M and NifU-M), and the second paralog lacks a targeting signal, thereby reflecting the cytosolic form of the NIF machinery (NifS-C and NifU-C). The dual localization of the NIF system corresponds to the presence of FeS proteins in both cellular compartments, including detectable hydrogenase activity in Mastigamoeba cytosol and mitochondria. In contrast, E. histolytica possesses only single genes encoding NifS and NifU, respectively, and there is no evidence for the presence of the NIF machinery in its reduced mitochondria. Thus, M. balamuthi is unique among eukaryotes in that its FeS cluster formation is mediated through two most likely independent NIF machineries present in two cellular compartments.

  5. Oxidative metabolism and Ca2+ handling in isolated brain mitochondria and striatal neurons from R6/2 mice, a model of Huntington's disease.

    Science.gov (United States)

    Hamilton, James; Pellman, Jessica J; Brustovetsky, Tatiana; Harris, Robert A; Brustovetsky, Nickolay

    2016-07-01

    Alterations in oxidative metabolism and defects in mitochondrial Ca 2+ handling have been implicated in the pathology of Huntington's disease (HD), but existing data are contradictory. We investigated the effect of human mHtt fragments on oxidative metabolism and Ca 2+ handling in isolated brain mitochondria and cultured striatal neurons from the R6/2 mouse model of HD. Non-synaptic and synaptic mitochondria isolated from the brains of R6/2 mice had similar respiratory rates and Ca 2+ uptake capacity compared with mitochondria from wild-type (WT) mice. Respiratory activity of cultured striatal neurons measured with Seahorse XF24 flux analyzer revealed unaltered cellular respiration in neurons derived from R6/2 mice compared with neurons from WT animals. Consistent with the lack of respiratory dysfunction, ATP content of cultured striatal neurons from R6/2 and WT mice was similar. Mitochondrial Ca 2+ accumulation was also evaluated in cultured striatal neurons from R6/2 and WT animals. Our data obtained with striatal neurons derived from R6/2 and WT mice show that both glutamate-induced increases in cytosolic Ca 2+ and subsequent carbonilcyanide p-triflouromethoxyphenylhydrazone-induced increases in cytosolic Ca 2+ were similar between WT and R6/2, suggesting that mitochondria in neurons derived from both types of animals accumulated comparable amounts of Ca 2+ Overall, our data argue against respiratory deficiency and impaired Ca 2+ handling induced by human mHtt fragments in both isolated brain mitochondria and cultured striatal neurons from transgenic R6/2 mice. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  6. Final report for project "Effects of Low-Dose Irradiation on NFkB Signaling Networks and Mitochondria"

    Energy Technology Data Exchange (ETDEWEB)

    Woloschak, Gayle E [Northwestern Univ., Evanston, IL (United States); Grdina, David [Univ. of Chicago, IL (United States); Li, Jian-Jian [Univ. of California, Davis, CA (United States)

    2017-06-12

    Low dose ionizing radiation effects are difficult to study in human population because of the numerous confounding factors such as genetic and lifestyle differences. Research in mammalian model systems and in vitro is generally used in order to overcome this difficulty. In this program project three projects have joined together to investigate effects of low doses of ionizing radiation. These are doses at and below 10 cGy of low linear energy transfer ionizing radiation such as X-ray and gamma rays. This project was focused on cellular signaling associated with nuclear factor kappa B (NFkB) and mitochondria - subcellular organelles critical for cell aging and aging-like changes induced by ionizing radiation. In addition to cells in culture this project utilized animal tissues accumulated in a radiation biology tissue archive housed at Northwestern University (http://janus.northwestern.edu/janus2/index.php). Major trust of Project 1 was to gather all of the DoE sponsored irradiated animal (mouse, rat and dog) data and tissues under one roof and investigate mitochondrial DNA changes and micro RNA changes in these samples. Through comparison of different samples we were trying to delineate mitochondrial DNA quantity alterations and micro RNA expression differences associated with different doses and dose rates of radiation. Historic animal irradiation experiments sponsored by DoE were done in several national laboratories and universities between 1950’s and 1990’s; while these experiments were closed data and tissues were released to Project 1. Project 2 used cells in culture to investigate effects that low doses or radiation have on NFκB and its target genes manganese superoxide dismutase (MnSOD) and genes involved in cell cycle: Cyclins (B1 and D1) and cyclin dependent kinases (CDKs). Project 3 used cells in culture such as “normal” human cells (breast epithelial cell line MCF10A cells and skin keratinocyte cells HK18) and mouse embryo fibroblast (mef

  7. Evidence for two compartments of exchangeable calcium in isolated rat liver mitochondria obtained using a 45Ca exchange technique in the presence of magnesium, phosphate, and ATPase at 370C

    International Nuclear Information System (INIS)

    Barritt, G.J.

    1981-01-01

    The distribution of calcium between isolated rat liver mitochondria and the extramitochondrial medium at 37 degrees C and in the presence of 2 mM inorganic phosphate, 3 mM ATP, 0.05 or 1.1 mM free magnesium and a calcium buffer, nitrilotriacetic acid, was investigated using a 45 Ca exchange technique. The amounts of 40 Ca in the mitochondria and medium were allowed to reach equilibrium before initiation of the measurement of 45 Ca exchange. At 0.05 mM free magnesium and initial extramitochondrial free calcium concentrations of between 0.15 and 0.5 microM, the mitochondria accumulated calcium until the extramitochondrial free calcium concentration was reduced to 0.15 microM. Control experiments showed that the mitochondria were stable under the incubation conditions employed. The 45 Ca exchange data were found to be consistent with a system in which two compartments of exchangeable calcium are associated with the mitochondria. Changes in the concentration of inorganic phosphate did not significantly affect the 45 Ca exchange curves, whereas an increase in the concentration of free magnesium inhibited exchange. The maximum rate of calcium outflow from the mitochondria was estimated to be 1.7 nmol/min per mg of protein, and the value of K0.5 for intramitochondrial exchangeable calcium to be about 1.6 nmol per mg of protein. Ruthenium Red decreased the fractional transfer rate for calcium inflow to the mitochondria while nupercaine affected principally the fractional transfer rates for the transfer of calcium between the two mitochondrial compartments. The use of the incubation conditions and 45 Ca exchange technique described in this report for studies of the effects of agents which may alter mitochondrial calcium uptake or release (e.g., the pre-treatment of cells with hormones) is briefly discussed

  8. Smectite alteration

    International Nuclear Information System (INIS)

    Anderson, D.M.

    1984-11-01

    This report contains the proceedings of a second workshop in Washington DC December 8-9, 1983 on the alteration of smectites intended for use as buffer materials in the long-term containment of nuclear wastes. It includes extended summaries of all presentations and a transcript of the detailed scientific discussion. The discussions centered on three main questions: What is the prerequisite for and what is the precise mechanism by which smectite clays may be altered to illite. What are likly sources of potassium with respect to the KBS project. Is it likely that the conversion of smectite to illite will be of importance in the 10 5 to the 10 6 year time frame. The workshop was convened to review considerations and conclusions in connection to these questions and also to broaden the discussion to consider the use of smectite clays as buffer materials for similar applications in different geographical and geological settings. SKBF/KBS technical report 83-03 contains the proceedings from the first workshop on these matters that was held at the State University of New York, Buffalo May 26-27, 1982. (Author)

  9. Oxidation and reduction of pyridine nucleotides in alamethicin-permeabilized plant mitochondria

    DEFF Research Database (Denmark)

    Johansson, F.I.; Michalecka, A.M.; Møller, I.M.

    2004-01-01

    method to permearbilize mitochondria and study the highly branched electron-transport chain in potato tuber (Solanum tuberosum) and pea leaf (Pisum sativum) mitochondria. We show that AlaM permeabilized the inner membrane of plant mitochondria to NAD(P)H, allowing the quantification of internal NAD......M-treated mitochondria was much higher than what has been previously measured by other techniques. Our results also show a difference in substrate specificities for complex I in mitochondria as compared with inside-out submitochondrial particles. AlaM facilitated the passage of cofactors to and from the mitochondrial...... environment not only in plant mitochondria but also in other membrane-enclosed compartments, such as intact cells, chloroplasts and peroxisomes....

  10. Improving oocyte quality by transfer of autologous mitochondria from fully grown oocytes

    DEFF Research Database (Denmark)

    Kristensen, Stine Gry; Pors, Susanne Elisabeth; Andersen, Claus Yding

    2017-01-01

    options using autologous mitochondria to potentially augment pregnancy potential in ART. Autologous transfer of mitochondria from the patient's own germline cells has attracted much attention as a possible new treatment to revitalize deficient oocytes. IVF births have been reported after transfer...... of oogonial precursor cell-derived mitochondria; however, the source and quality of the mitochondria are still unclear. In contrast, fully grown oocytes are loaded with mitochondria which have passed the genetic bottleneck and are likely to be of high quality. An increased supply of such oocytes could...... with high quality mitochondria can be obtained from natural or stimulated ovaries and potentially be used to improve both quality and quantity of oocytes available for fertility treatment....

  11. Human cultured cells are capable to incorporate isolated plant mitochondria loaded with exogenous DNA

    Directory of Open Access Journals (Sweden)

    Laktionov P. P.

    2012-07-01

    Full Text Available Aim. To investigate the possibility of human cultured cells to incorporate isolated mitochondria together with exogenous DNA introduced into organelles. Methods. Two approaches were used for this purpose, fluorescent labelling of mitochondria and/or DNA with subsequent analysis of the cells subjected to incubation by microscopy or by quantitative PCR. Results. We have shown that human cultured cells lines, HeLa and HUVEC, are capable to uptake isolated plant mitochondria and that this process depends on the incubation time and concentration of organelles present in medium. The incorporated mitochondria can serve as vehicles to deliver exogenous DNA into human cells, this DNA is then distributed in different cell compartments. Conclusions. These results are preliminary and need further investigations, including testing the possibility of human cells to incorporate the mitochondria of human or animal origin and creating genetic construction which could provide certain selectivity or stability of the transferred exogenous DNA upon cell uptake of the mitochondria as vectors.

  12. Morphological and quantitative changes in mitochondria, plastids, and peroxisomes during the log-to-stationary transition of the growth phase in cultured tobacco BY-2 cells.

    Science.gov (United States)

    Toyooka, Kiminori; Sato, Mayuko; Wakazaki, Mayumi; Matsuoka, Ken

    2016-01-01

    We developed a wide-range and high-resolution transmission electron microscope acquisition system and obtained giga-pixel images of tobacco BY-2 cells during the log and stationary phases of cell growth. We demonstrated that the distribution and ultrastructure of compartments involved in membrane traffic (i.e., Golgi apparatus, multivesicular body, and vesicle cluster) change during the log-to-stationary transition. Mitochondria, peroxisomes, and plastids were also enumerated. Electron densities of mitochondria and peroxisomes were altered during the growth-phase shift, while their numbers were reduced by nearly half. Plastid structure dramatically changed from atypical to spherical with starch granules. Nearly the same number of plastids was observed in both log and stationary phases. These results indicate that mechanisms regulating organelle populations differ from organelle to organelle.

  13. Computational properties of mitochondria in T cell activation and fate.

    Science.gov (United States)

    Uzhachenko, Roman; Shanker, Anil; Dupont, Geneviève

    2016-11-01

    In this article, we review how mitochondrial Ca 2+ transport (mitochondrial Ca 2+ uptake and Na + /Ca 2+ exchange) is involved in T cell biology, including activation and differentiation through shaping cellular Ca 2+ signals. Based on recent observations, we propose that the Ca 2+ crosstalk between mitochondria, endoplasmic reticulum and cytoplasm may form a proportional-integral-derivative (PID) controller. This PID mechanism (which is well known in engineering) could be responsible for computing cellular decisions. In addition, we point out the importance of analogue and digital signal processing in T cell life and implication of mitochondrial Ca 2+ transport in this process. © 2016 The Authors.

  14. An ancestral bacterial division system is widespread in eukaryotic mitochondria

    Czech Academy of Sciences Publication Activity Database

    Leger, M.M.; Petrů, M.; Žárský, V.; Eme, L.; Vlček, Čestmír; Harding, T.; Lang, B.F.; Eliáš, M.; Doležal, P.; Roger, A. J.

    2015-01-01

    Roč. 112, č. 33 (2015), s. 10239-10246 ISSN 0027-8424 R&D Projects: GA ČR GA13-24983S; GA MŠk(CZ) ED1.1.00/02.0109 Grant - others:GA ČR GA13-29423S; GA MŠk(CZ) CZ.1.05/1.1.00/02.0109 Institutional support: RVO:68378050 Keywords : mitochondria * Min proteins * MinCDE * mitochondrial fission * mitochondrial division Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 9.423, year: 2015

  15. The role of mitochondria in carbon catabolite repression in yeast.

    Science.gov (United States)

    Haussmann, P; Zimmermann, F K

    1976-10-18

    The role of mitochondria in carbon catabolite repression in Saccharomyces cerevisiae was investigated by comparing normal, respiratory competent (RHO) strains with their mitochondrially inherited, respiratory deficient mutant derivatives (rho). Formation of maltase and invertase was used as an indicator system for the effect of carbon catabolite repression on carbon catabolic reactions. Fermentation rates for glucose, maltose and sucrose were the same in RHO and rho strains. Specific activities of maltase and invertase were usually higher in the rho-mutants. A very pronounced difference in invertase levels was observed when cells were grown on maltose; rho-mutants had around 30 times more invertase than their RHO parent strains. The fact that rho-mutants were much less sensitive to carbon catabolite repression of invertase synthesis than their RHO parents was used to search for the mitochondrial factor(s) or function(s) involved in carbon catabolite repression. A possible metabolic influence of mitochondria on this system of regulation was tested after growth of RHO strains under anaerobic conditions (no respiration nor oxidative phosphorylation), in the presence of KCN (respiration inhibited), dinitrophenol (uncoupling of oxidative phosphorylation) and of both inhibitors anaerobic conditions and dinitrophenol had no effect on the extent of invertase repression. KCN reduced the degree of repression but not to the level found in rho-mutants. A combination of both inhibitors gave the same results as with KCN alone. Erythromycin and chloramphenicol were used as specific inhibitors of mitochondrial protein synthesis. Erythromycin prevented the formation of mitochondrial respiratory systems but did not induce rho-mutants under the conditions used. However, repression of invertase was as strong as in the absence of the inhibitor. Chloramphenicol led only to a slight reduction of the respiratory systems and did not affect invertase levels. A combination of both

  16. Aging changes of macromolecular synthesis in the mitochondria of mouse hepatocytes as revealed by microscopic radioautography

    Energy Technology Data Exchange (ETDEWEB)

    Nagata, Tetsuji [Shinshu University, Matsumoto (Japan). Dept. of Anatomy and Cell Biology

    2007-07-01

    This mini-review reports aging changes of macromolecular synthesis in the mitochondria of mouse hepatocytes. We have observed the macromolecular synthesis, such as DNA, RNA and proteins, in the mitochondria of various mammalian cells by means of electron microscopic radioautography technique developed in our laboratory. The number of mitochondria per cell, number of labeled mitochondria per cell with 3H-thymidine, 3H-uridine and 3H-leucine, precursors for DNA, RNA and proteins, respectively, were counted and the labeling indices at various ages, from fetal to postnatal early days and several months to 1 and 2 years in senescence, were calculated, which showed variations due to aging. (author)

  17. A conserved endoplasmic reticulum membrane protein complex (EMC facilitates phospholipid transfer from the ER to mitochondria.

    Directory of Open Access Journals (Sweden)

    Sujoy Lahiri

    2014-10-01

    Full Text Available Mitochondrial membrane biogenesis and lipid metabolism require phospholipid transfer from the endoplasmic reticulum (ER to mitochondria. Transfer is thought to occur at regions of close contact of these organelles and to be nonvesicular, but the mechanism is not known. Here we used a novel genetic screen in S. cerevisiae to identify mutants with defects in lipid exchange between the ER and mitochondria. We show that a strain missing multiple components of the conserved ER membrane protein complex (EMC has decreased phosphatidylserine (PS transfer from the ER to mitochondria. Mitochondria from this strain have significantly reduced levels of PS and its derivative phosphatidylethanolamine (PE. Cells lacking EMC proteins and the ER-mitochondria tethering complex called ERMES (the ER-mitochondria encounter structure are inviable, suggesting that the EMC also functions as a tether. These defects are corrected by expression of an engineered ER-mitochondrial tethering protein that artificially tethers the ER to mitochondria. EMC mutants have a significant reduction in the amount of ER tethered to mitochondria even though ERMES remained intact in these mutants, suggesting that the EMC performs an additional tethering function to ERMES. We find that all Emc proteins interact with the mitochondrial translocase of the outer membrane (TOM complex protein Tom5 and this interaction is important for PS transfer and cell growth, suggesting that the EMC forms a tether by associating with the TOM complex. Together, our findings support that the EMC tethers ER to mitochondria, which is required for phospholipid synthesis and cell growth.

  18. Rapid efflux of Ca2+ from heart mitochondria in the presence of inorganic pyrophosphate.

    Science.gov (United States)

    Vercesi, A; Lehninger, A L

    1984-01-13

    Inorganic pyrophosphate (PPi) in the intracellular concentration range causes rapid efflux of Ca2+ from rat heart mitochondria oxidizing pyruvate + malate in a low Na+ medium. Half-maximal rates of Ca2+ efflux were given by 20 microM PPi. During and after PPi-stimulated Ca2+ efflux the mitochondria retain their structural integrity and complete respiratory control. Carboxyatractyloside inhibits PPi-stimulated Ca2+ efflux, indicating PPi must enter the matrix in order to promote Ca2+ efflux. Heart mitochondria have a much higher affinity for PPi uptake and PPi-induced Ca2+ efflux than liver mitochondria.

  19. Respiration triggers heme transfer from cytochrome c peroxidase to catalase in yeast mitochondria

    Science.gov (United States)

    Kathiresan, Meena; Martins, Dorival; English, Ann M.

    2014-01-01

    In exponentially growing yeast, the heme enzyme, cytochrome c peroxidase (Ccp1) is targeted to the mitochondrial intermembrane space. When the fermentable source (glucose) is depleted, cells switch to respiration and mitochondrial H2O2 levels rise. It has long been assumed that CCP activity detoxifies mitochondrial H2O2 because of the efficiency of this activity in vitro. However, we find that a large pool of Ccp1 exits the mitochondria of respiring cells. We detect no extramitochondrial CCP activity because Ccp1 crosses the outer mitochondrial membrane as the heme-free protein. In parallel with apoCcp1 export, cells exhibit increased activity of catalase A (Cta1), the mitochondrial and peroxisomal catalase isoform in yeast. This identifies Cta1 as a likely recipient of Ccp1 heme, which is supported by low Cta1 activity in ccp1Δ cells and the accumulation of holoCcp1 in cta1Δ mitochondria. We hypothesized that Ccp1’s heme is labilized by hyperoxidation of the protein during the burst in H2O2 production as cells begin to respire. To test this hypothesis, recombinant Ccp1 was hyperoxidized with excess H2O2 in vitro, which accelerated heme transfer to apomyoglobin added as a surrogate heme acceptor. Furthermore, the proximal heme Fe ligand, His175, was found to be ∼85% oxidized to oxo-histidine in extramitochondrial Ccp1 isolated from 7-d cells, indicating that heme labilization results from oxidation of this ligand. We conclude that Ccp1 responds to respiration-derived H2O2 via a previously unidentified mechanism involving H2O2-activated heme transfer to apoCta1. Subsequently, the catalase activity of Cta1, not CCP activity, contributes to mitochondrial H2O2 detoxification. PMID:25422453

  20. Respiration triggers heme transfer from cytochrome c peroxidase to catalase in yeast mitochondria.

    Science.gov (United States)

    Kathiresan, Meena; Martins, Dorival; English, Ann M

    2014-12-09

    In exponentially growing yeast, the heme enzyme, cytochrome c peroxidase (Ccp1) is targeted to the mitochondrial intermembrane space. When the fermentable source (glucose) is depleted, cells switch to respiration and mitochondrial H2O2 levels rise. It has long been assumed that CCP activity detoxifies mitochondrial H2O2 because of the efficiency of this activity in vitro. However, we find that a large pool of Ccp1 exits the mitochondria of respiring cells. We detect no extramitochondrial CCP activity because Ccp1 crosses the outer mitochondrial membrane as the heme-free protein. In parallel with apoCcp1 export, cells exhibit increased activity of catalase A (Cta1), the mitochondrial and peroxisomal catalase isoform in yeast. This identifies Cta1 as a likely recipient of Ccp1 heme, which is supported by low Cta1 activity in ccp1Δ cells and the accumulation of holoCcp1 in cta1Δ mitochondria. We hypothesized that Ccp1's heme is labilized by hyperoxidation of the protein during the burst in H2O2 production as cells begin to respire. To test this hypothesis, recombinant Ccp1 was hyperoxidized with excess H2O2 in vitro, which accelerated heme transfer to apomyoglobin added as a surrogate heme acceptor. Furthermore, the proximal heme Fe ligand, His175, was found to be ∼ 85% oxidized to oxo-histidine in extramitochondrial Ccp1 isolated from 7-d cells, indicating that heme labilization results from oxidation of this ligand. We conclude that Ccp1 responds to respiration-derived H2O2 via a previously unidentified mechanism involving H2O2-activated heme transfer to apoCta1. Subsequently, the catalase activity of Cta1, not CCP activity, contributes to mitochondrial H2O2 detoxification.

  1. Drosophila larvae lacking the bcl-2 gene, buffy, are sensitive to nutrient stress, maintain increased basal target of rapamycin (Tor signaling and exhibit characteristics of altered basal energy metabolism

    Directory of Open Access Journals (Sweden)

    Monserrate Jessica P

    2012-07-01

    Full Text Available Abstract Background B cell lymphoma 2 (Bcl-2 proteins are the central regulators of apoptosis. The two bcl-2 genes in Drosophila modulate the response to stress-induced cell death, but not developmental cell death. Because null mutants are viable, Drosophila provides an optimum model system to investigate alternate functions of Bcl-2 proteins. In this report, we explore the role of one bcl-2 gene in nutrient stress responses. Results We report that starvation of Drosophila larvae lacking the bcl-2 gene, buffy, decreases survival rate by more than twofold relative to wild-type larvae. The buffy null mutant reacted to starvation with the expected responses such as inhibition of target of rapamycin (Tor signaling, autophagy initiation and mobilization of stored lipids. However, the autophagic response to starvation initiated faster in larvae lacking buffy and was inhibited by ectopic buffy. We demonstrate that unusually high basal Tor signaling, indicated by more phosphorylated S6K, was detected in the buffy mutant and that removal of a genomic copy of S6K, but not inactivation of Tor by rapamycin, reverted the precocious autophagy phenotype. Instead, Tor inactivation also required loss of a positive nutrient signal to trigger autophagy and loss of both was sufficient to activate autophagy in the buffy mutant even in the presence of enforced phosphoinositide 3-kinase (PI3K signaling. Prior to starvation, the fed buffy mutant stored less lipid and glycogen, had high lactate levels and maintained a reduced pool of cellular ATP. These observations, together with the inability of buffy mutant larvae to adapt to nutrient restriction, indicate altered energy metabolism in the absence of buffy. Conclusions All animals in their natural habitats are faced with periods of reduced nutrient availability. This study demonstrates that buffy is required for adaptation to both starvation and nutrient restriction. Thus, Buffy is a Bcl-2 protein that plays an

  2. A new hypothesis of pathogenesis based on the divorce between mitochondria and their host cells: possible relevance for Alzheimer's disease.

    Science.gov (United States)

    Agnati, L F; Guidolin, D; Baluska, F; Leo, G; Barlow, P W; Carone, C; Genedani, S

    2010-06-01

    On the basis of not only the endosymbiotic theory of eukaryotic cell organization and evolution but also of observations of transcellular communication via Tunneling NanoTubes (TNTs), the hypothesis is put forward that when mitochondria, which were once independently living prokaryote-like organisms, are subjected to detrimental genetic, toxic, or environmental conditions, including age-related endogenous factors, they can regress towards their original independent state. At that point, they can become potentially pathogenic intruders within their eukaryotic host cell. Because of the protoplasmic disequilibrium caused by an altered, or mutated, mitochondral population, certain host cells with a minimal capacity for self-renewal, such as dopaminergic neurons, risk a loss of function and degenerate. It is also proposed that altered mitochondria, as well as their mutated mtDNA, can migrate, via TNTs, into adjacent cells. In this way, neurodegenerative states are propagated between cells (glia and/or neurons) of the Central Nervous System (CNS) and that this leads to conditions such as Alzheimer's and Parkinson's disease. This proposal finds indirect support from observations on rotenone-poisoned glioblastoma cells which have been co-cultured with non-poisoned cells. Immunocytochemical techniques revealed that mitochondria, moving along the TNTs, migrated from the poisoned cells towards the healthy cells. It has also been demonstrated by means of immunocytochemistry that, in glioblastoma cell cultures, Amyloid Precursor Protein (APP) is present in TNTs, hence it may migrate from one cell to neighbouring cells. This datum may be of high relevance for a better understanding of Alzheimer's Disease (AD) since molecular, cellular, and animal model studies have revealed that the formation of amyloid beta (Abeta) and other derivatives of the APP are key pathogenic factors in AD, causing mitochondrial dysfunction, free radical generation, oxidative damage, and inflammation

  3. Ratiometric detection of pH fluctuation in mitochondria with a new fluorescein/cyanine hybrid sensor.

    Science.gov (United States)

    Chen, Yuncong; Zhu, Chengcheng; Cen, Jiajie; Bai, Yang; He, Weijiang; Guo, Zijian

    2015-05-01

    The homeostasis of mitochondrial pH (pH m ) is crucial in cell physiology. Developing small-molecular fluorescent sensors for the ratiometric detection of pH m fluctuation is highly demanded yet challenging. A ratiometric pH sensor, Mito-pH , was constructed by integrating a pH-sensitive FITC fluorophore with a pH-insensitive hemicyanine group. The hemicyanine group also acts as the mitochondria targeting group due to its lipophilic cationic nature. Besides its ability to target mitochondria, this sensor provides two ratiometric pH sensing modes, the dual excitation/dual emission mode (D ex /D em ) and dual excitation (D ex ) mode, and its linear and reversible ratiometric response range from pH 6.15 to 8.38 makes this sensor suitable for the practical tracking of pH m fluctuation in live cells. With this sensor, stimulated pH m fluctuation has been successfully tracked in a ratiometric manner via both fluorescence imaging and flow cytometry.

  4. Melatonin promotes Bax sequestration to mitochondria reducing cell susceptibility to apoptosis via the lipoxygenase metabolite 5-hydroxyeicosatetraenoic acid

    KAUST Repository

    Radogna, Flavia

    2015-03-01

    Extra-neurological functions of melatonin include control of the immune system and modulation of apoptosis. We previously showed that melatonin inhibits the intrinsic apoptotic pathway in leukocytes via stimulation of high affinity MT1/MT2 receptors, thereby promoting re-localization of the anti-apoptotic Bcl-2 protein to mitochondria. Here we show that Bcl-2 sequesters pro-apoptotic Bax into mitochondria in an inactive form after melatonin treatment, thus reducing cell propensity to apoptosis. Bax translocation and the anti-apoptotic effect of melatonin are strictly dependent on the presence of Bcl-2, and on the 5-lipoxygenase (5-LOX) metabolite 5-hydroxyeicosatetraenoic acid (5-HETE), which we have previously shown to be produced as a consequence of melatonin binding to its low affinity target calmodulin. Therefore, the anti-apoptotic effect of melatonin requires the simultaneous, independent interaction with high (MT1/MT2) and low (calmodulin) affinity targets, eliciting two independent signal transduction pathways converging into Bax sequestration and inactivation. MT1/MT2 vs. lipoxygenase pathways are activated by 10-9 vs. 10-5M melatonin, respectively; the anti-apoptotic effect of melatonin is achieved at 10-5M, but drops to 10-9M upon addition of exogenous 5-HETE, revealing that lipoxygenase activation is the rate-limiting pathway. Therefore, in areas of inflammation with increased 5-HETE levels, physiological nanomolar concentrations of melatonin may suffice to maintain leukocyte viability.

  5. Euglena mitochondria and chloroplasts form tyrosine-O-sulfate

    Energy Technology Data Exchange (ETDEWEB)

    Saidha, T.; Hanfstingl, U.; Schiff, J.A. (Brandeis Univ., Waltham, MA (USA))

    1989-04-01

    Mitochondria from light-grown wild-type Euglena gracilis var. bacillaris Cori or dark-grown mutant W{sub 10}BSmL incubated with {sup 35}SO{sub 4}{sup 2{minus}} and ATP, or with {sup 14}C-tyrosine, non-radioactive sulfate and ATP accumulate a labeled compound in the medium. Since this compound shows exact coelectrophoresis with tyrosine-O-sulfate (TOS) at pH 2.0, 5.8 or 8.0., yields sulfate and tyrosine on acid hydrolysis, and treatment with aryl sulfatase from Aerobacter aerogenes yields sulfate and tyrosine but no tyrosine methyl ester, it is identified as TOS. No TOS is found outside purified developing chloroplasts incubated with {sup 35}SO{sub 4}{sup 2{minus}} and ATP, but both chloroplasts and mitochondria form to {sup 35}S externally when incubated with adenosine 3{prime} phosphate 5{prime}phospho({sup 35}S) sulfate (PAP{sup 35}S). Since no tyrosine need be added, tyrosine is provided from endogenous sources. Although TOS is found in the free pool of Euglena cells it cannot be detected in proteins of cells or mucus ruling our sulfation of tyrosine of protein or incorporation of TOS into proteins. The system forming TOS is membrane-bound and may be involved in tyrosine transport.

  6. Action of diclofenac on kidney mitochondria and cells

    International Nuclear Information System (INIS)

    Ng, Lin Eng; Vincent, Annette S.; Halliwell, Barry; Wong, Kim Ping

    2006-01-01

    The mitochondrial membrane potential measured in isolated rat kidney mitochondria and in digitonin-permeabilized MDCK type II cells pre-energized with succinate, glutamate, and/or malate was reduced by micromolar diclofenac dose-dependently. However, ATP biosynthesis from glutamate/malate was significantly more compromised compared to that from succinate. Inhibition of the malate-aspartate shuttle by diclofenac with a resultant decrease in the ability of mitochondria to generate NAD(P)H was demonstrated. Diclofenac however had no effect on the activities of NADH dehydrogenase, glutamate dehydrogenase, and malate dehydrogenase. In conclusion, decreased NAD(P)H production due to an inhibition of the entry of malate and glutamate via the malate-aspartate shuttle explained the more pronounced decreased rate of ATP biosynthesis from glutamate and malate by diclofenac. This drug, therefore affects the bioavailability of two major respiratory complex I substrates which would normally contribute substantially to supplying the reducing equivalents for mitochondrial electron transport for generation of ATP in the renal cell

  7. Adenine nucleotide translocator transports haem precursors into mitochondria.

    Directory of Open Access Journals (Sweden)

    Motoki Azuma

    2008-08-01

    Full Text Available Haem is a prosthetic group for haem proteins, which play an essential role in oxygen transport, respiration, signal transduction, and detoxification. In haem biosynthesis, the haem precursor protoporphyrin IX (PP IX must be accumulated into the mitochondrial matrix across the inner membrane, but its mechanism is largely unclear. Here we show that adenine nucleotide translocator (ANT, the inner membrane transporter, contributes to haem biosynthesis by facilitating mitochondrial accumulation of its precursors. We identified that haem and PP IX specifically bind to ANT. Mitochondrial uptake of PP IX was inhibited by ADP, a known substrate of ANT. Conversely, ADP uptake into mitochondria was competitively inhibited by haem and its precursors, suggesting that haem-related porphyrins are accumulated into mitochondria via ANT. Furthermore, disruption of the ANT genes in yeast resulted in a reduction of haem biosynthesis by blocking the translocation of haem precursors into the matrix. Our results represent a new model that ANT plays a crucial role in haem biosynthesis by facilitating accumulation of its precursors into the mitochondrial matrix.

  8. Slower Dynamics and Aged Mitochondria in Sporadic Alzheimer's Disease

    Science.gov (United States)

    Gargini, Ricardo; García, Esther; Perry, George

    2017-01-01

    Sporadic Alzheimer's disease corresponds to 95% of cases whose origin is multifactorial and elusive. Mitochondrial dysfunction is a major feature of Alzheimer's pathology, which might be one of the early events that trigger downstream principal events. Here, we show that multiple genes that control mitochondrial homeostasis, including fission and fusion, are downregulated in Alzheimer's patients. Additionally, we demonstrate that some of these dysregulations, such as diminished DLP1 levels and its mitochondrial localization, as well as reduced STOML2 and MFN2 fusion protein levels, take place in fibroblasts from sporadic Alzheimer's disease patients. The analysis of mitochondrial network disruption using CCCP indicates that the patients' fibroblasts exhibit slower dynamics and mitochondrial membrane potential recovery. These defects lead to strong accumulation of aged mitochondria in Alzheimer's fibroblasts. Accordingly, the analysis of autophagy and mitophagy involved genes in the patients demonstrates a downregulation indicating that the recycling mechanism of these aged mitochondria might be impaired. Our data reinforce the idea that mitochondrial dysfunction is one of the key early events of the disease intimately related with aging. PMID:29201274

  9. Effect of heavy water on isolated rat liver mitochondria

    International Nuclear Information System (INIS)

    Huebner, G.

    1981-01-01

    The rate of O 2 consumption by isolated rat liver mitochondria was determined polarographically with a Clark electrode at 25 0 C in the active (state 3), strongly coupled (state 4) and decoupled state of the mitochondria in media containing H 2 16 O, D 2 16 O or H 2 18 O. The results confirm the value of the D 2 O isotope effect in the form on an O 2 -consumption inhibition. In H 2 18 O no isotope effect has been detected in the state of controlled respiration. In contrast, a strongly marked inverse isotope effect has been found in the active state after ADP addition and in the decoupled state after DNP addition. This inverse isotope effect occurs in reactions involving a preceding equilibrium. According to the chemiosmotic hypothesis of oxidative phosphorylation the formation of hydronium ions is part of this reaction. The equilibrium constant k 2 = 0.9774 for the hydronium ion in H 2 16 O and H 2 18 O implies that the formation of the hydronium ion in H 2 18 O is preferred to that in H 2 16 O. The high inverse H 2 18 O isotope effect respiration shows that the formation of H 3 O + contributes to the vectorial proton transport, probably as a preceding equilibrium, and that in the active state of the respiratory chain this reaction may be the rate-determining step. (author)

  10. Doubly uniparental inheritance of mitochondria as a model system for studying germ line formation.

    Directory of Open Access Journals (Sweden)

    Liliana Milani

    Full Text Available BACKGROUND: Doubly Uniparental Inheritance (DUI of mitochondria occurs when both mothers and fathers are capable of transmitting mitochondria to their offspring, in contrast to the typical Strictly Maternal Inheritance (SMI. DUI was found in some bivalve molluscs, in which two mitochondrial genomes are inherited, one through eggs, the other through sperm. During male embryo development, spermatozoon mitochondria aggregate in proximity of the first cleavage furrow and end up in the primordial germ cells, while they are dispersed in female embryos. METHODOLOGY/PRINCIPAL FINDINGS: We used MitoTracker, microtubule staining and transmission electron microscopy to examine the mechanisms of this unusual distribution of sperm mitochondria in the DUI species Ruditapes philippinarum. Our results suggest that in male embryos the midbody deriving from the mitotic spindle of the first division concurs in positioning the aggregate of sperm mitochondria. Furthermore, an immunocytochemical analysis showed that the germ line determinant Vasa segregates close to the first cleavage furrow. CONCLUSIONS/SIGNIFICANCE: In DUI male embryos, spermatozoon mitochondria aggregate in a stable area on the animal-vegetal axis: in organisms with spiral segmentation this zone is not involved in cleavage, so the aggregation is maintained. Moreover, sperm mitochondria reach the same embryonic area in which also germ plasm is transferred. In 2-blastomere embryos, the segregation of sperm mitochondria in the same region with Vasa suggests their contribution in male germ line formation. In DUI male embryos, M-type mitochondria must be recognized by egg factors to be actively transferred in the germ line, where they become dominant replacing the Balbiani body mitochondria. The typical features of germ line assembly point to a common biological mechanism shared by DUI and SMI organisms. Although the molecular dynamics of the segregation of sperm mitochondria in DUI species are unknown

  11. Accumulation of Exogenous Amyloid-Beta Peptide in Hippocampal Mitochondria Causes Their Dysfunction: A Protective Role for Melatonin

    Directory of Open Access Journals (Sweden)

    Sergio Rosales-Corral

    2012-01-01

    Full Text Available Amyloid-beta (Aβ pathology is related to mitochondrial dysfunction accompanied by energy reduction and an elevated production of reactive oxygen species (ROS. Monomers and oligomers of Aβ have been found inside mitochondria where they accumulate in a time-dependent manner as demonstrated in transgenic mice and in Alzheimer’s disease (AD brain. We hypothesize that the internalization of extracellular Aβ aggregates is the major cause of mitochondrial damage and here we report that following the injection of fibrillar Aβ into the hippocampus, there is severe axonal damage which is accompanied by the entrance of Aβ into the cell. Thereafter, Aβ appears in mitochondria where it is linked to alterations in the ionic gradient across the inner mitochondrial membrane. This effect is accompanied by disruption of subcellular structure, oxidative stress, and a significant reduction in both the respiratory control ratio and in the hydrolytic activity of ATPase. Orally administrated melatonin reduced oxidative stress, improved the mitochondrial respiratory control ratio, and ameliorated the energy imbalance.

  12. Taurine inhibits 2,5-hexanedione-induced oxidative stress and mitochondria-dependent apoptosis in PC12 cells.

    Science.gov (United States)

    Li, Shuangyue; Guan, Huai; Qian, Zhiqiang; Sun, Yijie; Gao, Chenxue; Li, Guixin; Yang, Yi; Piao, Fengyuan; Hu, Shuhai

    2017-04-07

    2,5-hexanedione (HD) is the ultimate neurotoxic metabolite of hexane, causing the progression of nerve diseases in human. It was reported that HD induced apoptosis and oxidative stress. Taurine has been shown to be a potent antioxidant. In the present study, we investigated the protection of taurine against HD-induced apoptosis in PC12 cells and the underlying mechanism. Our results showed the decreased viability and increased apoptosis in HD-exposed PC12 cells. HD also induced the disturbance of Bax and Bcl-2 expression, the loss of MMP, the release of mitochondrial cytochrome c and caspase-3 activation in PC12 cells. Moreover, HD resulted in an increase in reactive oxygen species (ROS) level and a decline in the activities of superoxidedismutase and catalase in PC12 cells. However, taurine pretreatment ameliorated the increased apoptosis and the alterations in key regulators of mitochondria-dependent pathway in PC12 exposed to HD. The increased ROS level and the decreased activities of the antioxidant enzymes in HD group were attenuated by taurine. These results indicate that pretreatment of taurine may, at least partly, prevent HD-induced apoptosis via inhibiting mitochondria-dependent pathway. It is also suggested that the potential of taurine against HD-induced apoptosis may benefit from its anti-oxidative property.

  13. Reduction of age-associated pathology in old mice by overexpression of catalase in mitochondria.

    Science.gov (United States)

    Treuting, Piper M; Linford, Nancy J; Knoblaugh, Sue E; Emond, M J; Morton, John F; Martin, George M; Rabinovitch, Peter S; Ladiges, Warren C

    2008-08-01

    We describe the effects of mitochondrially targeted catalase (MCAT) expression on end-of-life pathology in mice using detailed semiquantitative histopathological evaluation. We previously reported that the median and maximum life spans of MCAT mice were extended relative to those of wild-type littermates. We now report that MCAT expression is associated with reduced malignant nonhematopoietic tumor burden, reduced cardiac lesions, and a trend toward reduced systemic inflammation, with no effect on hematopoietic neoplasia or glomerulonephropathy. Combined disease burden and comorbidity are also reduced, and MCAT expression is not associated with any detrimental clinical effects. The results suggest that oxidative damage is involved in aging of C57BL/6J mice via modulation of a subset of age-associated lesions. Antioxidant interventions targeting mitochondria may therefore be a viable strategy for prevention or postponement of some age-associated diseases. The variability of the MCAT effect across tissues, however, illustrates the importance of developing semiquantitative histopathology for assessment of comorbidity in life-span studies.

  14. EST analysis on pig mitochondria reveal novel expression differences between developmental and adult tissues

    DEFF Research Database (Denmark)

    Scheibye-Alsing, Karsten; Cirera, Susanna; Gilchrist, Michael J.

    2007-01-01

    BACKGROUND: The mitochondria are involved in many basic functions in cells of vertebrates, and can be considered the power generator of the cell. Though the mitochondria have been extensively studied there appear to be only few expression studies of mitochondrial genes involving a large number...

  15. Cellular characterization of human dermal fibroblasts, focus on mitochondria and maple syrup urine disease

    DEFF Research Database (Denmark)

    Fernandez-Guerra, Paula

    and functions are expressed in HDFs’ culture environment. Studies of molecular disease mechanisms often point to the involvement of mitochondria. Mitochondria are involved in the regulation of cell cycle and programmed cell death as well as cellular stress responses because they are the main producers...

  16. Cardiac, skeletal, and smooth muscle mitochondrial respiration: are all mitochondria created equal?

    Science.gov (United States)

    Park, Song-Young; Gifford, Jayson R; Andtbacka, Robert H I; Trinity, Joel D; Hyngstrom, John R; Garten, Ryan S; Diakos, Nikolaos A; Ives, Stephen J; Dela, Flemming; Larsen, Steen; Drakos, Stavros; Richardson, Russell S

    2014-08-01

    Unlike cardiac and skeletal muscle, little is known about vascular smooth muscle mitochondrial respiration. Therefore, the present study examined mitochondrial respiratory rates in smooth muscle of healthy human feed arteries and compared with that of healthy cardiac and skeletal muscles. Cardiac, skeletal, and smooth muscles were harvested from a total of 22 subjects (53 ± 6 yr), and mitochondrial respiration was assessed in permeabilized fibers. Complex I + II, state 3 respiration, an index of oxidative phosphorylation capacity, fell progressively from cardiac to skeletal to smooth muscles (54 ± 1, 39 ± 4, and 15 ± 1 pmol·s(-1)·mg(-1), P respiration rates were normalized by CS (respiration per mitochondrial content), oxidative phosphorylation capacity was no longer different between the three muscle types. Interestingly, complex I state 2 normalized for CS activity, an index of nonphosphorylating respiration per mitochondrial content, increased progressively from cardiac to skeletal to smooth muscles, such that the respiratory control ratio, state 3/state 2 respiration, fell progressively from cardiac to skeletal to smooth muscles (5.3 ± 0.7, 3.2 ± 0.4, and 1.6 ± 0.3 pmol·s(-1)·mg(-1), P respiration highlight the existence of intrinsic functional differences between these muscle mitochondria. This likely influences the efficiency of oxidative phosphorylation and could potentially alter ROS production.

  17. Mitochondria Retrograde Signaling and the UPRmt: Where Are We in Mammals?

    Directory of Open Access Journals (Sweden)

    Thierry Arnould

    2015-08-01

    Full Text Available Mitochondrial unfolded protein response is a form of retrograde signaling that contributes to ensuring the maintenance of quality control of mitochondria, allowing functional integrity of the mitochondrial proteome. When misfolded proteins or unassembled complexes accumulate beyond the folding capacity, it leads to alteration of proteostasis, damages, and organelle/cell dysfunction. Extensively studied for the ER, it was recently reported that this kind of signaling for mitochondrion would also be able to communicate with the nucleus in response to impaired proteostasis. The mitochondrial unfolded protein response (UPRmt is activated in response to different types and levels of stress, especially in conditions where unfolded or misfolded mitochondrial proteins accumulate and aggregate. A specific UPRmt could thus be initiated to boost folding and degradation capacity in response to unfolded and aggregated protein accumulation. Although first described in mammals, the UPRmt was mainly studied in Caenorhabditis elegans, and accumulating evidence suggests that mechanisms triggered in response to a UPRmt might be different in C. elegans and mammals. In this review, we discuss and integrate recent data from the literature to address whether the UPRmt is relevant to mitochondrial homeostasis in mammals and to analyze the putative role of integrated stress response (ISR activation in response to the inhibition of mtDNA expression and/or accumulation of mitochondrial mis/unfolded proteins.

  18. Kidney outer medulla mitochondria are more efficient compared to cortex mitochondria as a strategy to sustain ATP production in a suboptimal environment.

    Science.gov (United States)

    Schiffer, Tomas A; Gustafsson, Håkan; Palm, Fredrik

    2018-05-30

    The kidneys receive approximately 25% of cardiac output, which is a prerequisite in order to maintain sufficient glomerular filtration rate. However, both intrarenal regional renal blood flow and tissue oxygen levels are heterogeneous with decreasing levels in the inner part of the medulla. These differences in combination with the heterogeneous metabolic activity of the different nephron segment located in the different parts of the kidney may constitute a functional problem when challenged. The proximal tubule and the medullary thick ascending limb of Henle are considered to have the highest metabolic rate, which is relating to the high mitochondria content needed to sustain sufficient ATP production from oxidative phosphorylation in order to support high electrolyte transport activity in these nephron segments. Interestingly, the cells located in kidney medulla functions at the verge of hypoxia and the mitochondria may have adapted to the surrounding environment. However, little is known about intrarenal differences in mitochondria function. We therefore investigated functional differences between mitochondria isolated from kidney cortex and medulla of healthy normoglycemic rats were estimated using high-resolution respirometry. The results demonstrate that medullary mitochondria had a higher degree of coupling, are more efficient and have higher oxygen affinity, which would make them more suitable to function in an environment with limited oxygen supply. Furthermore, these results support the hypothesis that mitochondria of medullary cells have adapted to the normal hypoxic in vivo situation as a strategy of sustaining ATP production in a suboptimal environment.

  19. The antiestrogen endoxifen protects rat liver mitochondria from permeability transition pore opening and oxidative stress at concentrations that do not affect the phosphorylation efficiency

    International Nuclear Information System (INIS)

    Ribeiro, Mariana P.C.; Silva, Filomena S.G.; Santos, Armanda E.; Santos, Maria S.; Custódio, José B.A.

    2013-01-01

    Endoxifen (EDX) is a key active metabolite of tamoxifen (TAM) with higher affinity and specificity to estrogen receptors that also inhibits aromatase activity. It is safe and well tolerated by healthy humans, but its use requires toxicological characterization. In this study, the effects of EDX on mitochondria, the primary targets for xenobiotic-induced toxicity, were monitored to clarify its potential side effects. EDX up to 30 nmol/mg protein did not affect the mitochondrial oxidative phosphorylation. At 50 nmol EDX/mg protein, EDX decreased the ADP phosphorylation rate and a partial collapse of mitochondrial membrane potential (Δψ), that parallels a state 4 stimulation, was observed. As the stimulation of state 4 was not inhibited by oligomycin and 50 nmol EDX/mg protein caused a slight decrease in the light scattering of mitochondria, these data suggest that EDX promotes membrane permeabilization to protons, whereas TAM at the same concentration induced mitochondrial membrane disruption. Moreover, EDX at 10 nmol/mg protein prevented and reversed the Ca 2+ -induced depolarization of ΔΨ and the release of mitochondrial Ca 2+ , similarly to cyclosporine A, indicating that EDX did not affect Ca 2+ uptake, but directly interfered with the proteins of the mitochondrial permeability transition (MPT) megacomplex, inhibiting MPT induction. At this concentration, EDX exhibited antioxidant activity that may account for the protective effect against MPT pore opening. In conclusion, EDX within the range of concentrations reached in tissues did not significantly damage the bioenergetic functions of mitochondria, contrarily to the prodrug TAM, and prevented the MPT pore opening and the oxidative stress in mitochondria, supporting that EDX may be a less toxic drug for women with breast carcinoma. - Highlights: ► Mitochondria are important targets of Endoxifen. ► Endoxifen prevents mitochondrial permeability transition. ► Endoxifen prevents oxidative stress in

  20. The antiestrogen endoxifen protects rat liver mitochondria from permeability transition pore opening and oxidative stress at concentrations that do not affect the phosphorylation efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro, Mariana P.C.; Silva, Filomena S.G.; Santos, Armanda E. [Center for Neuroscience and Cell Biology, University of Coimbra, 3000-354 Coimbra (Portugal); Laboratory of Biochemistry, Faculty of Pharmacy, University of Coimbra, 3000-548 Coimbra (Portugal); Santos, Maria S. [Center for Neuroscience and Cell Biology, University of Coimbra, 3000-354 Coimbra (Portugal); Department of Life Sciences, Faculty of Sciences and Technology, University of Coimbra, 3004-517 Coimbra (Portugal); Custódio, José B.A., E-mail: custodio@ci.uc.pt [Center for Neuroscience and Cell Biology, University of Coimbra, 3000-354 Coimbra (Portugal); Laboratory of Biochemistry, Faculty of Pharmacy, University of Coimbra, 3000-548 Coimbra (Portugal)

    2013-02-15

    Endoxifen (EDX) is a key active metabolite of tamoxifen (TAM) with higher affinity and specificity to estrogen receptors that also inhibits aromatase activity. It is safe and well tolerated by healthy humans, but its use requires toxicological characterization. In this study, the effects of EDX on mitochondria, the primary targets for xenobiotic-induced toxicity, were monitored to clarify its potential side effects. EDX up to 30 nmol/mg protein did not affect the mitochondrial oxidative phosphorylation. At 50 nmol EDX/mg protein, EDX decreased the ADP phosphorylation rate and a partial collapse of mitochondrial membrane potential (Δψ), that parallels a state 4 stimulation, was observed. As the stimulation of state 4 was not inhibited by oligomycin and 50 nmol EDX/mg protein caused a slight decrease in the light scattering of mitochondria, these data suggest that EDX promotes membrane permeabilization to protons, whereas TAM at the same concentration induced mitochondrial membrane disruption. Moreover, EDX at 10 nmol/mg protein prevented and reversed the Ca{sup 2+}-induced depolarization of ΔΨ and the release of mitochondrial Ca{sup 2+}, similarly to cyclosporine A, indicating that EDX did not affect Ca{sup 2+} uptake, but directly interfered with the proteins of the mitochondrial permeability transition (MPT) megacomplex, inhibiting MPT induction. At this concentration, EDX exhibited antioxidant activity that may account for the protective effect against MPT pore opening. In conclusion, EDX within the range of concentrations reached in tissues did not significantly damage the bioenergetic functions of mitochondria, contrarily to the prodrug TAM, and prevented the MPT pore opening and the oxidative stress in mitochondria, supporting that EDX may be a less toxic drug for women with breast carcinoma. - Highlights: ► Mitochondria are important targets of Endoxifen. ► Endoxifen prevents mitochondrial permeability transition. ► Endoxifen prevents oxidative

  1. Dose enhancement effects to the nucleus and mitochondria from gold nanoparticles in the cytosol

    Science.gov (United States)

    McNamara, AL; Kam, WW-Y; Scales, N; McMahon, SJ; Bennett, JW; Byrne, HL; Schuemann, J; Paganetti, H; Banati, R; Kuncic, Z

    2016-01-01

    Gold nanoparticles (GNPs) have shown potential as dose enhancers for radiation therapy. Since damage to the genome affects the viability of a cell, it is generally assumed that GNPs have to localise within the cell nucleus. In practice, however, GNPs tend to localise in the cytoplasm yet still appear to have a dose enhancing effect on the cell. Whether this effect can be attributed to stress-induced biological mechanisms or to physical damage to extra-nuclear cellular targets is still unclear. There is however growing evidence to suggest that the cellular response to radiation can also be influenced by indirect processes induced when the nucleus is not directly targeted by radiation. The mitochondrion in particular may be an effective extra-nuclear radiation target given its many important functional roles in the cell. To more accurately predict the physical effect of radiation within different cell organelles, we measured the full chemical composition of a whole human lymphocytic JURKAT cell as well as two separate organelles; the cell nucleus and the mitochondrion. The experimental measurements found that all three biological materials had similar ionisation energies ~ 70 eV, substantially lower than that of liquid water ~ 78 eV. Monte Carlo simulations for 10 – 50 keV incident photons showed higher energy deposition and ionisation numbers in the cell and organelle materials compared to liquid water. Adding a 1% mass fraction of gold to each material increased the energy deposition by a factor of ~ 1.8 when averaged over all incident photon energies. Simulations of a realistic compartmentalised cell show that the presence of gold in the cytosol increases the energy deposition in the mitochondrial volume more than within the nuclear volume. We find this is due to sub-micron delocalisation of energy by photoelectrons, making the mitochondria a potentially viable indirect radiation target for GNPs that localise to the cytosol. PMID:27435339

  2. The fate of paternal mitochondria in marmoset pre-implantation embryos.

    Science.gov (United States)

    Luetjens, C M; Wesselmann, R

    2008-06-01

    Sperm-derived mitochondria are integrated into the oocyte at fertilization but seem to vanish during the early cleavage phase. The developmental potential of pre-implantation embryos seems to be closely related to their ability to induce degeneration of these mitochondria, but the mechanisms underlying their loss of function are not yet understood. This study focuses on the fate of paternal mitochondria in pre-implantation embryos. Stimulation, collection and in vitro culture of oocytes from Callithrix jacchus, allows the study of the destiny of paternal mitochondria by utilizing immunostaining of pre-implantation embryos, fluorescence and laserscanning microscopy. Live pre-implantation embryos were stained with a fluorescence indicator reflecting mitochondrial membrane potential. Evidence indicating the loss of mitochondrial function was not found nor that apoptosis pathways were involved in the disappearance of paternally derived mitochondria. These findings may have implications for mitochondrially inherited diseases and could lead to new strategies for improving assisted reproduction.

  3. Effect of sclerin on amino acid incorporation into mitochondria isolated from rat liver

    International Nuclear Information System (INIS)

    Yamaguchi, Masanori; Satomura, Yukio

    1975-01-01

    Though sclerin (SCL) stimulated amino acid incorporation into the protein fraction of post mitochondrial supernatant of rat liver homogenate, it had no effect on the incorporation into the isolated mitochondria at pH 7.2, despite of its stimulating effect on mitochondrial oxidative phosphorylation. SCL stimulated amino acid incorporation into the mitochondria at pH 6.1, and to some extent maintained the activity on that in mitochondria during aging in hypotonic Tris-HCl buffer (pH 7.2). Since SCL prevented leakage of amino acids from the mitochondria into these buffers, it was suggested that SCL may protect a structure of mitochondrial membrane which appeared to have a significance on transport of amino acids. In liver slices, SCL stimulated amino acid incorporation only into the extra-mitochondrial fraction for the first 3 min, but gradually turned to simulate incorporation into mitochondria within 30 min. (auth.)

  4. Uncoupling and oxidative stress in liver mitochondria isolated from rats with acute iron overload

    Energy Technology Data Exchange (ETDEWEB)

    Pardo Andreu, G.L. [Centro de Quimica Farmaceutica, Departamento de Investigaciones Biomedicas, Ciudad de La Habana (Cuba); Inada, N.M.; Vercesi, A.E. [Universidade Estadual de Campinas, Departamento de Patologia Clinica, Faculdade de Ciencias Medicas, Campinas, SP (Brazil); Curti, C. [Universidade de Sao Paulo, Departamento de Fisica e Quimica, Faculdade de Ciencias Farmaceuticas de Ribeirao Preto, SP (Brazil)

    2009-01-15

    One hypothesis for the etiology of cell damage arising from iron overload is that its excess selectively affects mitochondria. Here we tested the effects of acute iron overload on liver mitochondria isolated from rats subjected to a single dose of i.p. 500 mg/kg iron-dextran. The treatment increased the levels of iron in mitochondria (from 21{+-}4 to 130{+-}7 nmol/mg protein) and caused both lipid peroxidation and glutathione oxidation. The mitochondria of iron-treated rats showed lower respiratory control ratio in association with higher resting respiration. The mitochondrial uncoupling elicited by iron-treatment did not affect the phosphorylation efficiency or the ATP levels, suggesting that uncoupling is a mitochondrial protective mechanism against acute iron overload. Therefore, the reactive oxygen species (ROS)/H{sup +} leak couple, functioning as a mitochondrial redox homeostatic mechanism could play a protective role in the acutely iron-loaded mitochondria. (orig.)

  5. Specificity of DNA import into isolated mitochondria from plants and mammals

    Directory of Open Access Journals (Sweden)

    Koulintchenko M. V.

    2014-01-01

    Full Text Available Aim. Investigation of different features of DNA import into plant and human mitochondria, for a better understanding of mitochondrial genetics and generation of biotechnological tools. Methods. DNA up-take experiments with isolated plant mitochondria, using as substrates various sequences associated or not with the specific terminal inverted repeats (TIRs present at each end of the plant mitochondrial linear plasmids. Results. It was established that the DNA import efficiency has a non-linear dependence on DNA size. It was shown that import into plant mitochondria of DNA molecules of «medium» sizes, i. e. between 4 and 7 kb, barely has any sequence specificity: neither TIRs from the 11.6 kb Brassica plasmid, nor TIRs from the Zea mays S-plasmids influenced DNA import into Solanum tuberosum mitochondria. Conclusions. The data obtained support the hypothesis about species-specific import mechanism operating under the mitochondrial linear plasmids transfer into plant mitochondria.

  6. Effect of sclerin on amino acid incorporation into mitochondria isolated from rat liver

    Energy Technology Data Exchange (ETDEWEB)

    Yamaguchi, M; Satomura, Y [Osaka City Univ. (Japan). Faculty of Science

    1975-08-01

    Though sclerin (SCL) stimulated amino acid incorporation into the protein fraction of post mitochondrial supernatant of rat liver homogenate, it had no effect on the incorporation into the isolated mitochondria at pH 7.2, despite of its stimulating effect on mitochondrial oxidative phosphorylation. SCL stimulated amino acid incorporation into the mitochondria at pH 6.1, and to some extent maintained the activity on that in mitochondria during aging in hypotonic Tris-HCl buffer (pH 7.2). Since SCL prevented leakage of amino acids from the mitochondria into these buffers, it was suggested that SCL may protect a structure of mitochondrial membrane which appeared to have a significance on transport of amino acids. In liver slices, SCL stimulated amino acid incorporation only into the extra-mitochondrial fraction for the first 3 min, but gradually turned to simulate incorporation into mitochondria within 30 min.

  7. Huperzine A protects isolated rat brain mitochondria against beta-amyloid peptide.

    Science.gov (United States)

    Gao, Xin; Zheng, Chun Yan; Yang, Ling; Tang, Xi Can; Zhang, Hai Yan

    2009-06-01

    Our previous work in cells and animals showed that mitochondria are involved in the neuroprotective effect of huperzine A (HupA). In this study, the effects of HupA on isolated rat brain mitochondria were investigated. In addition to inhibiting the Abeta(25-35) (40 microM)-induced decrease in mitochondrial respiration, adenosine 5'-triphosphate (ATP) synthesis, enzyme activity, and transmembrane potential, HupA (0.01 or 0.1 microM) effectively prevented Abeta-induced mitochondrial swelling, reactive oxygen species increase, and cytochrome c release. More interestingly, administration of HupA to isolated mitochondria promoted the rate of ATP production and blocked mitochondrial swelling caused by normal osmosis. These results indicate that HupA protects mitochondria against Abeta at least in part by preserving membrane integrity and improving energy metabolism. These direct effects on mitochondria further extend the noncholinergic functions of HupA.

  8. 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.

  9. Correlation between chloride flux via the mitochondria-rich cells and transepithelial water movement in isolated frog skin (Rana esculenta)

    DEFF Research Database (Denmark)

    Nielsen, Robert

    1995-01-01

    Antidiuretic hormone; chloride transport; electroosmosis; Frog skin; Intercalated cells; Local osmosis; Mitochondria-rich cells.......Antidiuretic hormone; chloride transport; electroosmosis; Frog skin; Intercalated cells; Local osmosis; Mitochondria-rich cells....

  10. Mitochondrially targeted vitamin E succinate efficiently kills breast tumour-initiating cells in a complex II-dependent manner

    International Nuclear Information System (INIS)

    Yan, Bi