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Sváb G, Kokas M, Sipos I, Ambrus A, Tretter L. Methylene Blue Bridges the Inhibition and Produces Unusual Respiratory Changes in Complex III-Inhibited Mitochondria. Studies on Rats, Mice and Guinea Pigs. Antioxidants (Basel) 2021; 10:antiox10020305. [PMID: 33669457 PMCID: PMC7920423 DOI: 10.3390/antiox10020305] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 02/04/2021] [Accepted: 02/10/2021] [Indexed: 11/23/2022] Open
Abstract
Methylene blue (MB) is used in human therapy in various pathological conditions. Its effects in neurodegenerative disease models are promising. MB acts on multiple cellular targets and mechanisms, but many of its potential beneficial effects are ascribed to be mitochondrial. According to the “alternative electron transport” hypothesis, MB is capable of donating electrons to cytochrome c bypassing complex I and III. As a consequence of this, the deleterious effects of the inhibitors of complex I and III can be ameliorated by MB. Recently, the beneficial effects of MB exerted on complex III-inhibited mitochondria were debated. In the present contribution, several pieces of evidence are provided towards that MB is able to reduce cytochrome c and improve bioenergetic parameters, like respiration and membrane potential, in mitochondria treated with complex III inhibitors, either antimycin or myxothiazol. These conclusions were drawn from measurements for mitochondrial oxygen consumption, membrane potential, NAD(P)H steady state, MB uptake and MB-cytochrome c oxidoreduction. In the presence of MB and complex III inhibitors, unusual respiratory reactions, like decreased oxygen consumption as a response to ADP addition as well as stimulation of respiration upon administration of inhibitors of ATP synthase or ANT, were observed. Qualitatively identical results were obtained in three rodent species. The actual metabolic status of mitochondria is well reflected in the distribution of MB amongst various compartments of this organelle.
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Affiliation(s)
- Gergely Sváb
- Laboratory of Neurobiochemistry, Department of Biochemistry, Institute of Biochemistry and Molecular Biology MTA-SE, Semmelweis University, POB. 262 Budapest, H-1444 Budapest, Hungary; (G.S.); (M.K.); (A.A.)
| | - Márton Kokas
- Laboratory of Neurobiochemistry, Department of Biochemistry, Institute of Biochemistry and Molecular Biology MTA-SE, Semmelweis University, POB. 262 Budapest, H-1444 Budapest, Hungary; (G.S.); (M.K.); (A.A.)
| | - Ildikó Sipos
- Department of Neurology, Semmelweis University, POB. 262 Budapest, H-1444 Budapest, Hungary;
| | - Attila Ambrus
- Laboratory of Neurobiochemistry, Department of Biochemistry, Institute of Biochemistry and Molecular Biology MTA-SE, Semmelweis University, POB. 262 Budapest, H-1444 Budapest, Hungary; (G.S.); (M.K.); (A.A.)
| | - László Tretter
- Laboratory of Neurobiochemistry, Department of Biochemistry, Institute of Biochemistry and Molecular Biology MTA-SE, Semmelweis University, POB. 262 Budapest, H-1444 Budapest, Hungary; (G.S.); (M.K.); (A.A.)
- Correspondence: ; Tel.: +36-1-459-1500/60010
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Olowe R, Sandouka S, Saadi A, Shekh-Ahmad T. Approaches for Reactive Oxygen Species and Oxidative Stress Quantification in Epilepsy. Antioxidants (Basel) 2020; 9:E990. [PMID: 33066477 PMCID: PMC7602129 DOI: 10.3390/antiox9100990] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2020] [Revised: 10/01/2020] [Accepted: 10/07/2020] [Indexed: 12/27/2022] Open
Abstract
Oxidative stress (OS) and excessive reactive oxygen species (ROS) production have been implicated in many neurological pathologies, including acute seizures and epilepsy. Seizure-induced damage has been demonstrated both in vitro and in several in vivo seizure and epilepsy models by direct determination of ROS, and by measuring indirect markers of OS. In this manuscript, we review the current reliable methods for quantifying ROS-related and OS-related markers in pre-clinical and clinical epilepsy studies. We first provide pieces of evidence for the involvement of different sources of ROS in epilepsy. We then discuss general methods and assays used for the ROS measurements, mainly superoxide anion, hydrogen peroxide, peroxynitrite, and hydroxyl radical in in vitro and in vivo studies. In addition, we discuss the role of these ROS and markers of oxidative injury in acute seizures and epilepsy pre-clinical studies. The indirect detection of secondary products of ROS such as measurements of DNA damage, lipid peroxidation, and protein oxidation will also be discussed. This review also discusses reliable methods for the assessment of ROS, OS markers, and their by-products in epilepsy clinical studies.
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Affiliation(s)
| | | | | | - Tawfeeq Shekh-Ahmad
- The Institute for Drug Research, The School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 91120, Israel; (R.O.); (S.S.); (A.S.)
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3
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Bioenergetic Impairment of Triethylene Glycol Dimethacrylate- (TEGDMA-) Treated Dental Pulp Stem Cells (DPSCs) and Isolated Brain Mitochondria are Amended by Redox Compound Methylene Blue †. MATERIALS 2020; 13:ma13163472. [PMID: 32781723 PMCID: PMC7475988 DOI: 10.3390/ma13163472] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 07/27/2020] [Accepted: 08/03/2020] [Indexed: 12/16/2022]
Abstract
BACKGROUND Triethylene glycol dimethacrylate (TEGDMA) monomers released from resin matrix are toxic to dental pulp cells, induce apoptosis, oxidative stress and decrease viability. Recently, mitochondrial complex I (CI) was identified as a potential target of TEGDMA. In isolated mitochondria supported by CI, substrates oxidation and ATP synthesis were inhibited, reactive oxygen species production was stimulated. Contrary to that, respiratory Complex II was not impaired by TEGDMA. The beneficial effects of electron carrier compound methylene blue (MB) are proven in many disease models where mitochondrial involvement has been detected. In the present study, the bioenergetic effects of MB on TEGDMA-treated isolated mitochondria and on human dental pulp stem cells (DPSC) were analyzed. METHODS Isolated mitochondria and DPSC were acutely exposed to low millimolar concentrations of TEGDMA and 2 μM concentration of MB. Mitochondrial and cellular respiration and glycolytic flux were measured by high resolution respirometry and by Seahorse XF extracellular analyzer. Mitochondrial membrane potential was measured fluorimetrically. RESULTS MB partially restored the mitochondrial oxidation, rescued membrane potential in isolated mitochondria and significantly increased the impaired cellular O2 consumption in the presence of TEGDMA. CONCLUSION MB is able to protect against TEGDMA-induced CI damage, and might provide protective effects in resin monomer exposed cells.
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Duong QV, Hoffman A, Zhong K, Dessinger MJ, Zhang Y, Bazil JN. Calcium overload decreases net free radical emission in cardiac mitochondria. Mitochondrion 2020; 51:126-139. [PMID: 31982614 DOI: 10.1016/j.mito.2020.01.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 12/08/2019] [Accepted: 01/08/2020] [Indexed: 12/21/2022]
Abstract
Elevated calcium and reactive oxygen species (ROS) are responsible for the bulk of cell death occurring in a variety of clinical settings that include acute coronary events, cerebrovascular accidents, and acute kidney injury. It is commonly believed that calcium and ROS participate in a viscous cycle during these events. However, the precise feedback mechanisms are unknown. We quantitatively demonstrate in this study that, on the contrary, calcium does not stimulate free radical production but suppresses it. Isolated mitochondria from guinea pig hearts were energized with a variety of substrates and exposed to calcium concentrations designed to induce moderate calcium overload conditions associated with ischemia/reperfusion injury but do not elicit the well-known mitochondrial permeability transition phenomenon. Metabolic function and free radical emission were simultaneously quantified using high-resolution respirometry and fluorimetry. Membrane potential, high amplitude swelling, and calcium dynamics were also quantified in parallel. Our results reveal that calcium overload does not lead to excessive ROS emission but does decrease ADP stimulated respiration rates for NADH-dependent pathways. Moreover, we developed an empirical model of mitochondrial free radical homeostasis to identify the processes that are different for each substrate and calcium condition. In summary, we show that in healthy guinea pig mitochondria, calcium uptake and free radical generation do not contribute to a viscous cycle and that the relationship between net free radical production and oxygen concentration is hyperbolic. Altogether, these results lay out an important foundation necessary to quantitatively determine the role of calcium in IR injury and ROS production.
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Affiliation(s)
- Quynh V Duong
- Department of Biochemistry and Molecular Biology, Michigan State University, United States
| | - Adrianna Hoffman
- Department of Physiology, Michigan State University, United States
| | - Katie Zhong
- Department of Physiology, Michigan State University, United States
| | | | - Yizhu Zhang
- Department of Physiology, Michigan State University, United States
| | - Jason N Bazil
- Department of Physiology, Michigan State University, United States.
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5
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Svab G, Doczi J, Gerencser AA, Ambrus A, Gallyas F, Sümegi B, Tretter L. The Mitochondrial Targets of Neuroprotective Drug Vinpocetine on Primary Neuron Cultures, Brain Capillary Endothelial Cells, Synaptosomes, and Brain Mitochondria. Neurochem Res 2019; 44:2435-2447. [PMID: 31535355 PMCID: PMC6776483 DOI: 10.1007/s11064-019-02871-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Revised: 08/29/2019] [Accepted: 09/05/2019] [Indexed: 12/13/2022]
Abstract
Vinpocetine is considered as neuroprotectant drug and used for treatment of brain ischemia and cognitive deficiencies for decades. A number of enzymes, channels and receptors can bind vinpocetine, however the mechanisms of many effects' are still not clear. The present study investigated the effects of vinpocetine from the mitochondrial bioenergetic aspects. In primary brain capillary endothelial cells the purinergic receptor-stimulated mitochondrial Ca2+ uptake and efflux were studied. Vinpocetine exerted a partial inhibition on the mitochondrial calcium efflux. In rodent brain synaptosomes vinpocetine (30 μM) inhibited respiration in uncoupler stimulated synaptosomes and decreased H2O2 release from the nerve terminals in resting and in complex I inhibited conditions, respectively. In isolated rat brain mitochondria using either complex I or complex II substrates leak respiration was stimulated, but ADP-induced respiration was inhibited by vinpocetine. The stimulation of oxidation was associated with a small extent of membrane depolarization. Mitochondrial H2O2 production was inhibited by vinpocetine under all conditions investigated. The most pronounced effects were detected with the complex II substrate succinate. Vinpocetine also mitigated both Ca2+-induced mitochondrial Ca2+-release and Ca2+-induced mitochondrial swelling. It lowered the rate of mitochondrial ATP synthesis, while increasing ATPase activity. These results indicate more than a single mitochondrial target of this vinca alkaloid. The relevance of the affected mitochondrial mechanisms in the anti ischemic effect of vinpocetine is discussed.
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Affiliation(s)
- Gergely Svab
- Department of Medical Biochemistry, MTA-SE Laboratory for Neurobiochemistry, Semmelweis University, 37-47 Tuzolto Street, Budapest, 1094, Hungary
| | - Judit Doczi
- Department of Medical Biochemistry, MTA-SE Laboratory for Neurobiochemistry, Semmelweis University, 37-47 Tuzolto Street, Budapest, 1094, Hungary
| | - Akos A Gerencser
- Department of Medical Biochemistry, MTA-SE Laboratory for Neurobiochemistry, Semmelweis University, 37-47 Tuzolto Street, Budapest, 1094, Hungary.,Buck Institute for Research on Aging, Novato, CA, USA
| | - Attila Ambrus
- Department of Medical Biochemistry, MTA-SE Laboratory for Neurobiochemistry, Semmelweis University, 37-47 Tuzolto Street, Budapest, 1094, Hungary
| | - Ferenc Gallyas
- Department of Biochemistry and Medical Chemistry, University of Pecs Medical School, Pecs, Hungary.,Szentagothai Research Centre, University of Pecs, Pecs, Hungary.,Nuclear-Mitochondrial Interactions Research Group, Hungarian Academy of Sciences, Budapest, Hungary
| | - Balazs Sümegi
- Department of Biochemistry and Medical Chemistry, University of Pecs Medical School, Pecs, Hungary.,Szentagothai Research Centre, University of Pecs, Pecs, Hungary.,Nuclear-Mitochondrial Interactions Research Group, Hungarian Academy of Sciences, Budapest, Hungary
| | - László Tretter
- Department of Medical Biochemistry, MTA-SE Laboratory for Neurobiochemistry, Semmelweis University, 37-47 Tuzolto Street, Budapest, 1094, Hungary.
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Kostyuk AI, Panova AS, Bilan DS, Belousov VV. Redox biosensors in a context of multiparameter imaging. Free Radic Biol Med 2018; 128:23-39. [PMID: 29630928 DOI: 10.1016/j.freeradbiomed.2018.04.004] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Revised: 03/18/2018] [Accepted: 04/04/2018] [Indexed: 12/22/2022]
Abstract
A wide variety of genetically encoded fluorescent biosensors are available to date. Some of them have already contributed significantly to our understanding of biological processes occurring at cellular and organismal levels. Using such an approach, outstanding success has been achieved in the field of redox biology. The probes allowed researchers to observe, for the first time, the dynamics of important redox parameters in vivo during embryogenesis, aging, the inflammatory response, the pathogenesis of various diseases, and many other processes. Given the differences in the readout and spectra of the probes, they can be used in multiparameter imaging in which several processes are monitored simultaneously in the cell. Intracellular processes form an extensive network of interactions. For example, redox changes are often accompanied by changes in many other biochemical reactions related to cellular metabolism and signaling. Therefore, multiparameter imaging can provide important information concerning the temporal and spatial relationship of various signaling and metabolic processes. In this review, we will describe the main types of genetically encoded biosensors, the most frequently used readout, and their use in multiplexed imaging mode.
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Affiliation(s)
- Alexander I Kostyuk
- Faculty of Biology, Moscow State University, Moscow, Russia; Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow 117997, Russia
| | - Anastasiya S Panova
- Faculty of Biology, Moscow State University, Moscow, Russia; Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow 117997, Russia
| | - Dmitry S Bilan
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow 117997, Russia; Pirogov Russian National Research Medical University, Moscow 117997, Russia
| | - Vsevolod V Belousov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow 117997, Russia; Pirogov Russian National Research Medical University, Moscow 117997, Russia; Institute for Cardiovascular Physiology, Georg August University Göttingen, Göttingen D-37073, Germany.
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Komlódi T, Geibl FF, Sassani M, Ambrus A, Tretter L. Membrane potential and delta pH dependency of reverse electron transport-associated hydrogen peroxide production in brain and heart mitochondria. J Bioenerg Biomembr 2018; 50:355-365. [PMID: 30116920 PMCID: PMC6209044 DOI: 10.1007/s10863-018-9766-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Accepted: 07/30/2018] [Indexed: 12/19/2022]
Abstract
Succinate-driven reverse electron transport (RET) is one of the main sources of mitochondrial reactive oxygen species (mtROS) in ischemia-reperfusion injury. RET is dependent on mitochondrial membrane potential (Δψm) and transmembrane pH difference (ΔpH), components of the proton motive force (pmf); a decrease in Δψm and/or ΔpH inhibits RET. In this study we aimed to determine which component of the pmf displays the more dominant effect on RET-provoked ROS generation in isolated guinea pig brain and heart mitochondria respiring on succinate or α-glycerophosphate (α-GP). Δψm was detected via safranin fluorescence and a TPP+ electrode, the rate of H2O2 formation was measured by Amplex UltraRed, the intramitochondrial pH (pHin) was assessed via BCECF fluorescence. Ionophores were used to dissect the effects of the two components of pmf. The K+/H+ exchanger, nigericin lowered pHin and ΔpH, followed by a compensatory increase in Δψm that led to an augmented H2O2 production. Valinomycin, a K+ ionophore, at low [K+] increased ΔpH and pHin, decreased Δψm, which resulted in a decline in H2O2 formation. It was concluded that Δψm is dominant over ∆pH in modulating the succinate- and α-GP-evoked RET. The elevation of extramitochondrial pH was accompanied by an enhanced H2O2 release and a decreased ∆pH. This phenomenon reveals that from the pH component not ∆pH, but rather absolute value of pH has higher impact on the rate of mtROS formation. Minor decrease of Δψm might be applied as a therapeutic strategy to attenuate RET-driven ROS generation in ischemia-reperfusion injury.
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Affiliation(s)
- Tímea Komlódi
- Department of Medical Biochemistry, MTA-SE Laboratory for Neurobiochemistry, Semmelweis University, 37-47 Tűzoltó St, Budapest, 1094, Hungary
| | - Fanni F Geibl
- Department of Medical Biochemistry, MTA-SE Laboratory for Neurobiochemistry, Semmelweis University, 37-47 Tűzoltó St, Budapest, 1094, Hungary.,Department of Neurology, Philipps University Marburg, 35043, Marburg, Germany
| | - Matilde Sassani
- Department of Medical Biochemistry, MTA-SE Laboratory for Neurobiochemistry, Semmelweis University, 37-47 Tűzoltó St, Budapest, 1094, Hungary.,Department of Neuroscience, Sheffield Institute for Translational Neuroscience (SITraN), University of Sheffield, Sheffield, UK
| | - Attila Ambrus
- Department of Medical Biochemistry, MTA-SE Laboratory for Neurobiochemistry, Semmelweis University, 37-47 Tűzoltó St, Budapest, 1094, Hungary
| | - László Tretter
- Department of Medical Biochemistry, MTA-SE Laboratory for Neurobiochemistry, Semmelweis University, 37-47 Tűzoltó St, Budapest, 1094, Hungary.
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8
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Tong BCK, Wu AJ, Li M, Cheung KH. Calcium signaling in Alzheimer's disease & therapies. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2018; 1865:1745-1760. [PMID: 30059692 DOI: 10.1016/j.bbamcr.2018.07.018] [Citation(s) in RCA: 147] [Impact Index Per Article: 24.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Revised: 07/12/2018] [Accepted: 07/23/2018] [Indexed: 12/15/2022]
Abstract
Alzheimer's disease (AD) is the most common type of dementia and is characterized by the accumulation of amyloid (Aβ) plaques and neurofibrillary tangles in the brain. Much attention has been given to develop AD treatments based on the amyloid cascade hypothesis; however, none of these drugs had good efficacy at improving cognitive functions in AD patients suggesting that Aβ might not be the disease origin. Thus, there are urgent needs for the development of new therapies that target on the proximal cause of AD. Cellular calcium (Ca2+) signals regulate important facets of neuronal physiology. An increasing body of evidence suggests that age-related dysregulation of neuronal Ca2+ homeostasis may play a proximal role in the pathogenesis of AD as disrupted Ca2+ could induce synaptic deficits and promote the accumulation of Aβ plaques and neurofibrillary tangles. Given that Ca2+ disruption is ubiquitously involved in all AD pathologies, it is likely that using chemical agents or small molecules specific to Ca2+ channels or handling proteins on the plasma membrane and membranes of intracellular organelles to correct neuronal Ca2+ dysregulation could open up a new approach to AD prevention and treatment. This review summarizes current knowledge on the molecular mechanisms linking Ca2+ dysregulation with AD pathologies and discusses the possibility of correcting neuronal Ca2+ disruption as a therapeutic approach for AD.
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Affiliation(s)
- Benjamin Chun-Kit Tong
- School of Chinese Medicine, Hong Kong Baptist University, 7 Baptist University Road, Kowloon Tong, Kowloon, Hong Kong, China
| | - Aston Jiaxi Wu
- School of Chinese Medicine, Hong Kong Baptist University, 7 Baptist University Road, Kowloon Tong, Kowloon, Hong Kong, China
| | - Min Li
- School of Chinese Medicine, Hong Kong Baptist University, 7 Baptist University Road, Kowloon Tong, Kowloon, Hong Kong, China
| | - King-Ho Cheung
- School of Chinese Medicine, Hong Kong Baptist University, 7 Baptist University Road, Kowloon Tong, Kowloon, Hong Kong, China.
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9
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Triethylene glycol dimethacrylate impairs bioenergetic functions and induces oxidative stress in mitochondria via inhibiting respiratory Complex I. Dent Mater 2018; 34:e166-e181. [DOI: 10.1016/j.dental.2018.03.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2017] [Revised: 01/22/2018] [Accepted: 03/23/2018] [Indexed: 11/23/2022]
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10
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Abstract
SIGNIFICANCE Hydrogen peroxide (H2O2) is not only a key mediator of oxidative stress but also one of the most important cellular second messengers. This small short-lived molecule is involved in the regulation of a wide range of different biological processes, including regulation of cellular signaling pathways. Studying the role of H2O2 in living systems would be challenging without modern approaches. A genetically encoded fluorescent biosensor, HyPer, is one of the most effective tools for this purpose. RECENT ADVANCES HyPer has been used by many investigators of redox signaling in various models of different scales: from cytoplasmic subcompartments and single cells to tissues of whole organisms. In many studies, the results obtained using HyPer have enabled a better understanding of the roles of H2O2 in these biological processes. However, much remains to be learned. CRITICAL ISSUES In this review, we focus on the uses of HyPer. We provide a general description of HyPer and its improved versions. Separate chapters are devoted to the results obtained by various groups who have used this biosensor for their experiments in living cells and organisms. FUTURE DIRECTIONS HyPer is an effective tool for H2O2 imaging in living systems as indicated by the increasing numbers of publications each year since its development. However, this biosensor requires further improvements. In particular, much brighter and more pH-stable versions of HyPer are necessary for imaging in mammalian tissues. Antioxid. Redox Signal. 24, 731-751.
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Affiliation(s)
- Dmitry S Bilan
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry , Moscow, Russia
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11
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Tretter L, Horvath G, Hölgyesi A, Essek F, Adam-Vizi V. Enhanced hydrogen peroxide generation accompanies the beneficial bioenergetic effects of methylene blue in isolated brain mitochondria. Free Radic Biol Med 2014; 77:317-30. [PMID: 25277417 DOI: 10.1016/j.freeradbiomed.2014.09.024] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2014] [Revised: 09/02/2014] [Accepted: 09/18/2014] [Indexed: 12/21/2022]
Abstract
The redox dye methylene blue (MB) is proven to have beneficial effects in various models of neurodegenerative diseases. Here we investigated the effects of MB (100 nM, 300 nM, and 1 μM) on key bioenergetic parameters and on H2O2 production/elimination in isolated guinea pig brain mitochondria under normal as well as respiration-impaired conditions. As measured by high-resolution Oxygraph the rate of resting oxygen consumption was increased, but the ADP-stimulated respiration was unaffected by MB with any of the substrates (glutamate malate, succinate, or α-glycerophosphate) used for supporting mitochondrial respiration. In mitochondria treated with inhibitors of complex I or complex III MB moderately but significantly increased the rate of ATP production, restored ΔΨm, and increased the rate of Ca(2+) uptake. The effects of MB are consistent with transferring electrons from upstream components of the electron transport chain to cytochrome c, which is energetically favorable when the flow of electrons in the respiratory chain is compromised. On the other hand, MB significantly increased the production of H2O2 measured by Amplex UltraRed fluorimetry under all conditions, in resting, ATP-synthesizing, and respiration-impaired mitochondria, with each substrate combination supporting respiration. Furthermore, it also decreased the elimination of H2O2. Generation of H2O2 without superoxide formation, observed in the presence of MB, is interpreted as a result of reduction of molecular oxygen to H2O2 by the reduced MB. The elevated generation and impaired elimination of H2O2 should be considered for the overall oxidative state of mitochondria treated with MB.
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Affiliation(s)
- L Tretter
- MTA-SE Laboratory for Neurobiochemistry, Department of Medical Biochemistry, Semmelweis University, Budapest H-1094, Hungary
| | - G Horvath
- MTA-SE Laboratory for Neurobiochemistry, Department of Medical Biochemistry, Semmelweis University, Budapest H-1094, Hungary
| | - A Hölgyesi
- MTA-SE Laboratory for Neurobiochemistry, Department of Medical Biochemistry, Semmelweis University, Budapest H-1094, Hungary
| | - F Essek
- MTA-SE Laboratory for Neurobiochemistry, Department of Medical Biochemistry, Semmelweis University, Budapest H-1094, Hungary
| | - V Adam-Vizi
- MTA-SE Laboratory for Neurobiochemistry, Department of Medical Biochemistry, Semmelweis University, Budapest H-1094, Hungary.
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12
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Ermakova YG, Bilan DS, Matlashov ME, Mishina NM, Markvicheva KN, Subach OM, Subach FV, Bogeski I, Hoth M, Enikolopov G, Belousov VV. Red fluorescent genetically encoded indicator for intracellular hydrogen peroxide. Nat Commun 2014; 5:5222. [PMID: 25330925 PMCID: PMC4553041 DOI: 10.1038/ncomms6222] [Citation(s) in RCA: 191] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Accepted: 09/09/2014] [Indexed: 01/10/2023] Open
Abstract
Reactive oxygen species (ROS) are conserved regulators of numerous cellular functions, and overproduction of ROS is a hallmark of various pathological processes. Genetically encoded fluorescent probes are unique tools to study ROS production in living systems of different scale and complexity. However, the currently available recombinant redox sensors have green emission, which overlaps with the spectra of many other probes. Expanding the spectral range of recombinant in vivo ROS probes would enable multiparametric in vivo ROS detection. Here we present the first genetically encoded red fluorescent sensor for hydrogen peroxide detection, HyPerRed. The performance of this sensor is similar to its green analogues. We demonstrate the utility of the sensor by tracing low concentrations of H2O2 produced in the cytoplasm of cultured cells upon growth factor stimulation. Moreover, using HyPerRed we detect local and transient H2O2 production in the mitochondrial matrix upon inhibition of the endoplasmic reticulum Ca(2+) uptake.
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Affiliation(s)
- Yulia G Ermakova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia
| | - Dmitry S Bilan
- 1] Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia [2] NBIC, Moscow Institute of Physics and Technology, 123182 Moscow, Russia
| | - Mikhail E Matlashov
- 1] Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia [2] NBIC, Moscow Institute of Physics and Technology, 123182 Moscow, Russia
| | - Natalia M Mishina
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia
| | | | - Oksana M Subach
- NBIC, Moscow Institute of Physics and Technology, 123182 Moscow, Russia
| | - Fedor V Subach
- NBIC, Moscow Institute of Physics and Technology, 123182 Moscow, Russia
| | - Ivan Bogeski
- Department of Biophysics, School of Medicine, Saarland University, Homburg 66421, Germany
| | - Markus Hoth
- Department of Biophysics, School of Medicine, Saarland University, Homburg 66421, Germany
| | - Grigori Enikolopov
- 1] NBIC, Moscow Institute of Physics and Technology, 123182 Moscow, Russia [2] Cold Spring Harbor Laboratory, Cold Spring Harbor, New York 11724, USA
| | - Vsevolod V Belousov
- 1] Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia [2] NBIC, Moscow Institute of Physics and Technology, 123182 Moscow, Russia
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13
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Adam-Vizi V, Tretter L. The role of mitochondrial dehydrogenases in the generation of oxidative stress. Neurochem Int 2013; 62:757-63. [DOI: 10.1016/j.neuint.2013.01.012] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2012] [Revised: 01/08/2013] [Accepted: 01/10/2013] [Indexed: 01/09/2023]
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14
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The role of the mitochondrial calcium uniporter in cerebral ischemia/reperfusion injury in rats involves regulation of mitochondrial energy metabolism. Mol Med Rep 2013; 7:1073-80. [PMID: 23426506 DOI: 10.3892/mmr.2013.1321] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2012] [Accepted: 02/05/2013] [Indexed: 11/05/2022] Open
Abstract
The mitochondrial calcium uniporter (MCU) maintains intracellular Ca2+ homeostasis by transporting Ca2+ from the cell cytosol into the mitochondrial matrix and is important for shaping Ca2+ signals and the activation of programmed cell death. Inhibition of MCU by ruthenium red (RR) or Ru360 has previously been reported to protect against neuronal death. The aim of the present study was to analyze the mechanisms underlying the effects of MCU activity in a rat model of cerebral ischemia/reperfusion (I/R) injury. Adult male Wistar rats were divided into 4 groups; sham, I/R, I/R + RR and I/R + spermine (Sper) and were subjected to reversible middle cerebral artery occlusion for 2 h followed by 24 h of reperfusion. A bolus injection of RR administered 30 min prior to ischemia was found to significantly decrease the total infarct volume and reduce neuronal damage and cell apoptosis compared with ischemia/reperfusion values. However, treatment with Sper, an activator of the MCU, increased the injury induced by I/R. Analysis of energy metabolism revealed that I/R induced progressive inhibition of complexes I‑IV of the electron transport chain, decreased ATP production, dissipated the mitochondrial membrane potential and increased the generation of reactive oxygen species. Treatment with RR ameliorated the condition, while spermine had the opposite effect. In conclusion, blocking MCU was demonstrated to exert protective effects against I/R injury and this process may be mediated by the prevention of energy failure.
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Tretter L, Adam-Vizi V. High Ca2+ load promotes hydrogen peroxide generation via activation of α-glycerophosphate dehydrogenase in brain mitochondria. Free Radic Biol Med 2012; 53:2119-30. [PMID: 23022874 DOI: 10.1016/j.freeradbiomed.2012.09.029] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2012] [Revised: 09/03/2012] [Accepted: 09/20/2012] [Indexed: 12/22/2022]
Abstract
H(2)O(2) generation associated with α-glycerophosphate (α-GP) oxidation was addressed in guinea pig brain mitochondria challenged with high Ca(2+) load (10 μM). Exposure to 10 μM Ca(2+) induced an abrupt 2.5-fold increase in H(2)O(2) release compared to that measured in the presence of a physiological cytosolic Ca(2+) concentration (100 nM) from mitochondria respiring on 5 mM α-GP in the presence of ADP (2 mM). The Ca(2+)-induced stimulation of H(2)O(2) generation was reversible and unaltered by the uniporter blocker Ru 360, indicating that it did not require Ca(2+) uptake into mitochondria. Enhanced H(2)O(2) generation by Ca(2+) was also observed in the absence of ADP when mitochondria exhibited permeability transition pore opening with a decrease in the NAD(P)H level, dissipation of membrane potential, and mitochondrial swelling. Furthermore, mitochondria treated with the pore-forming peptide alamethicin also responded with an elevated H(2)O(2) generation to a challenge with 10 μM Ca(2+). Ca(2+)-induced promotion of H(2)O(2) formation was further enhanced by the complex III inhibitor myxothiazol. With 20 mM α-GP concentration, stimulation of H(2)O(2) formation by Ca(2+) was detected only in the presence, not in the absence, of ADP. It is concluded that α-glycerophosphate dehydrogenase, which is accessible to and could be activated by a rise in the level of cytosolic Ca(2+), makes a major contribution to Ca(2+)-stimulated H(2)O(2) generation. This work highlights a unique high-Ca(2+)-stimulated reactive oxygen species-forming mechanism in association with oxidation of α-GP, which is largely independent of the bioenergetic state and can proceed even in damaged, functionally incompetent mitochondria.
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Affiliation(s)
- Laszlo Tretter
- Department of Medical Biochemistry, Semmelweis University, Budapest H-1444, Hungary
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C-Phycocyanin protects SH-SY5Y cells from oxidative injury, rat retina from transient ischemia and rat brain mitochondria from Ca2+/phosphate-induced impairment. Brain Res Bull 2012; 89:159-67. [DOI: 10.1016/j.brainresbull.2012.08.011] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2012] [Revised: 08/09/2012] [Accepted: 08/30/2012] [Indexed: 01/26/2023]
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Yarana C, Sanit J, Chattipakorn N, Chattipakorn S. Synaptic and nonsynaptic mitochondria demonstrate a different degree of calcium-induced mitochondrial dysfunction. Life Sci 2012; 90:808-14. [DOI: 10.1016/j.lfs.2012.04.004] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2011] [Revised: 04/04/2012] [Accepted: 04/05/2012] [Indexed: 10/28/2022]
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Abstract
Mitochondria are often regarded as the powerhouse of the cell by generating the ultimate energy transfer molecule, ATP, which is required for a multitude of cellular processes. However, the role of mitochondria goes beyond their capacity to create molecular fuel, to include the generation of reactive oxygen species, the regulation of calcium, and activation of cell death. Mitochondrial dysfunction is part of both normal and premature ageing, but can contribute to inflammation, cell senescence, and apoptosis. Cardiovascular disease, and in particular atherosclerosis, is characterized by DNA damage, inflammation, cell senescence, and apoptosis. Increasing evidence indicates that mitochondrial damage and dysfunction also occur in atherosclerosis and may contribute to the multiple pathological processes underlying the disease. This review summarizes the normal role of mitochondria, the causes and consequences of mitochondrial dysfunction, and the evidence for mitochondrial damage and dysfunction in vascular disease. Finally, we highlight areas of mitochondrial biology that may have therapeutic targets in vascular disease.
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Affiliation(s)
- Emma Yu
- Division of Cardiovascular Medicine, University of Cambridge, Box 110, Addenbrooke's Hospital, Cambridge CB2 0QQ, UK
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Tretter L, Biagioni Angeli E, Ardestani MR, Goracci G, Adam-Vizi V. Reversible inhibition of hydrogen peroxide elimination by calcium in brain mitochondria. J Neurosci Res 2011; 89:1965-72. [PMID: 21541982 DOI: 10.1002/jnr.22658] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2011] [Revised: 03/03/2011] [Accepted: 03/14/2011] [Indexed: 11/07/2022]
Abstract
In the present work, the Ca(2+) dependence of mitochondrial H(2) O(2) elimination was investigated. Mitochondria isolated from guinea pig brain were energized by glutamate and malate and incubated with micromolar concentrations of Ca(2+) in the presence of ADP, preventing permeability transition pore formation. After the completion of Ca(2+) uptake, mitochondria were challenged with H(2) O(2) (5 μM), then at various time points residual H(2) O(2) was determined using the Amplex red method and compared with that in mitochondria incubated with H(2) O(2) without Ca(2+) addition. Dose-dependent inhibition of H(2) O(2) elimination by Ca(2+) was detected, which was prevented by the Ca(2+) -uptake inhibitor Ru 360. Stimulation of Ca(2+) release from Ca(2+) -loaded mitochondria by a combined addition of Ru 360 and Na(+) decreased the Ca(2+) -evoked inhibition of H(2) O(2) removal. After Ca(2+) uptake (50 μM), mitochondrial aconitase activity was found to be decreased, which was partially attributable to the impaired elimination of endogenously produced reactive oxygen species. We found that the effects of Ca(2+) and H(2) O(2) on the activity of aconitase were additive. These results confirm that Ca(2+) inhibits elimination of H(2) O(2) in mitochondria and demonstrate that this effect is concentration dependent and reversible. The phenomenon described here can play a role in the modulation of ROS handling under conditions involving excessive cellular Ca(2+) load.
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Affiliation(s)
- Laszlo Tretter
- Department of Medical Biochemistry, Semmelweis University, and Laboratory of Neurobiochemistry and Molecular Physiology, Hungarian Academy of Sciences, Budapest, Hungary
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20
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Adam-Vizi V, Starkov AA. Calcium and mitochondrial reactive oxygen species generation: how to read the facts. J Alzheimers Dis 2010; 20 Suppl 2:S413-26. [PMID: 20421693 DOI: 10.3233/jad-2010-100465] [Citation(s) in RCA: 184] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
A number of recent discoveries indicate that abnormal Ca2+ signaling, oxidative stress, and mitochondrial dysfunction are involved in the neuronal damage in Alzheimer's disease. However, the literature on the interactions between these factors is controversial especially in the interpretation of the cause-effect relationship between mitochondrial damage induced by Ca2+ overload and the production of reactive oxygen species (ROS). In this review, we survey the experimental observations on the Ca2+-induced mitochondrial ROS production, explain the sources of controversy in interpreting these results, and discuss the different molecular mechanisms underlying the effect of Ca2+ on the ROS emission by brain mitochondria.
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Affiliation(s)
- Vera Adam-Vizi
- Department of Medical Biochemistry, Semmelweis University, Neurobiochemical Group of Hungarian Academy of Sciences, Budapest, Hungary.
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21
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Malinska D, Kulawiak B, Kudin AP, Kovacs R, Huchzermeyer C, Kann O, Szewczyk A, Kunz WS. Complex III-dependent superoxide production of brain mitochondria contributes to seizure-related ROS formation. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2010; 1797:1163-70. [DOI: 10.1016/j.bbabio.2010.03.001] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2009] [Revised: 02/19/2010] [Accepted: 03/01/2010] [Indexed: 01/16/2023]
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22
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Mirandola SR, Melo DR, Saito A, Castilho RF. 3-nitropropionic acid-induced mitochondrial permeability transition: comparative study of mitochondria from different tissues and brain regions. J Neurosci Res 2010; 88:630-9. [PMID: 19795369 DOI: 10.1002/jnr.22239] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The adult rat striatum is particularly vulnerable to systemic administration of the succinate dehydrogenase inhibitor 3-nitropropionic acid (3NP), which is known to induce degeneration of the caudate-putamen, as occurs in Huntington's disease. The aim of the present study was to compare the susceptibility of isolated mitochondria from different rat brain regions (striatum, cortex, and cerebellum) as well as from the liver, kidney, and heart to mitochondrial permeability transition (MPT) induced by 3NP and Ca(2+). In the presence of micromolar Ca(2+) concentrations, 3NP induces MPT in a dose-dependent manner, as estimated by mitochondrial swelling and a decrease in the transmembrane electrical potential. A 3NP concentration capable of promoting a 10% inhibition of ADP-stimulated, succinate-supported respiration was sufficient to stimulate Ca(2+)-induced MPT. Brain and heart mitochondria were generally more sensitive to 3NP and Ca(2+)-induced MPT than mitochondria from liver and kidney. In addition, a partial inhibition of mitochondrial respiration by 3NP resulted in more pronounced MPT in striatal mitochondria than in cortical or cerebellar organelles. A similar inhibition of succinate dehydrogenase activity was observed in rat tissue homogenates obtained from various brain regions as well as from liver, kidney, and heart 24 hr after a single i.p. 3NP dose. Mitochondria isolated from forebrains of 3NP-treated rats were also more susceptible to Ca(2+)-induced MPT than those of control rats. We propose that the increased susceptibility of the striatum to 3NP-induced neurodegeneration may be partially explained by its susceptibility to MPT, together with the greater vulnerability of this brain region to glutamate receptor-mediated Ca(2+) influx.
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Affiliation(s)
- Sandra R Mirandola
- Departamento de Patologia Clínica, Faculdade de Ciências Médicas, Universidade Estadual de Campinas , Campinas, Brazil
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Komary Z, Tretter L, Adam-Vizi V. Membrane potential-related effect of calcium on reactive oxygen species generation in isolated brain mitochondria. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2010; 1797:922-8. [PMID: 20230776 DOI: 10.1016/j.bbabio.2010.03.010] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 12/11/2009] [Revised: 03/04/2010] [Accepted: 03/06/2010] [Indexed: 01/29/2023]
Abstract
The effect of Ca2+ applied in high concentrations (50 and 300 microM) was addressed on the generation of reactive oxygen species in isolated mitochondria from guinea-pig brain. The experiments were performed in the presence of ADP, a very effective inhibitor of mitochondrial permeability transition. Moderate increase in H2O2 release from mitochondria was induced by Ca2+ applied in 50 microM, but not in 300 microM concentration as measured with Amplex red fluorescent assay starting with a delay of 100-150 sec after exposure to Ca2+. Parallel measurements of membrane potential (DeltaPsim) by safranine fluorescence showed a transient depolarization by Ca2+ followed by the recovery of DeltaPsim to a value, which was more negative than that observed before addition of Ca2+ indicating a relative hyperpolarization. NAD(P)H fluorescence was also increased by Ca2+ given in 50 microM concentration. In mitochondria having high DeltaPsim in the presence of oligomycin or ATP, the basal rate of release of H2O2 was significantly higher than that observed in a medium containing ADP and Ca2+ no longer increased but rather decreased the rate of H2O2 release. With 300 microM Ca2+ only a loss but no tendency of a recovery of DeltaPsim was detected and H2O2 release was unchanged. It is suggested that in the presence of nucleotides the effect of Ca2+ on mitochondrial ROS release is related to changes in DeltaPsim; in depolarized mitochondria, in the presence of ADP, moderate increase in H2O2 release is induced by calcium, but only in <or=100 microM concentration, when after a transient Ca2+-induced depolarization mitochondria became more polarized. In highly polarized mitochondria, in the presence of ATP or oligomycin, where no hyperpolarization follows the Ca2+-induced depolarization, Ca2+ fails to stimulate mitochondrial ROS generation. These effects of calcium (<or=300 microM) are unrelated to mitochondrial permeability transition.
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Affiliation(s)
- Zsofia Komary
- Department of Medical Biochemistry, Semmelweis University, Neurobiochemical Group, Hungarian Academy of Sciences, Hungary
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Shi Z, Feng Y, Wang J, Zhang H, Ding L, Dai J. Perfluorododecanoic acid-induced steroidogenic inhibition is associated with steroidogenic acute regulatory protein and reactive oxygen species in cAMP-stimulated Leydig cells. Toxicol Sci 2010; 114:285-94. [PMID: 20100736 DOI: 10.1093/toxsci/kfq014] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Perfluorododecanoic acid (PFDoA) can be detected in environmental matrices and human serum and has been shown to inhibit testicular steroidogenesis in rats. However, the mechanisms that are responsible for the toxic effects of PFDoA remain unknown. The aims of this study were to investigate the mechanism of steroidogenesis inhibition by PFDoA and to identify the molecular target of PFDoA in Leydig cells. The effects of PFDoA on steroid synthesis in Leydig cells were assessed by radioimmunoassay. The expression of key genes and proteins in steroid biosynthesis was determined by real-time PCR and Western blot analysis. Reactive oxygen species (ROS) and hydrogen peroxide (H(2)O(2)) levels were determined using bioluminescence assays. PFDoA inhibited adenosine 3',5'-cyclophosphate (cAMP)-stimulated steroidogenesis in mouse Leydig tumor cells (mLTC-1) and primary rat Leydig cells in a dose-dependent manner. However, PFDoA (1-100 microM) did not exhibit effects on cell viability and cellular ATP levels in mLTC-1 cells. PFDoA inhibited steroidogenic acute regulatory protein (StAR) promoter activity and StAR expression at the messenger RNA (mRNA) and protein levels but did not affect mRNA levels of peripheral-type benzodiazepine receptor, cholesterol side-chain cleavage enzyme, or 3beta-hydroxysteroid dehydrogenase in cAMP-stimulated mLTC-1 cells. PFDoA treatment also resulted in increased levels of mitochondrial ROS and H(2)O(2). After excessive ROS and H(2)O(2) were eliminated in PFDoA-treated mLTC-1 cells by MnTMPyP (a superoxide dismutase analog), progesterone production was partially restored and StAR mRNA and protein levels were partially recovered. These data show that PFDoA inhibits steroidogenesis in cAMP-stimulated Leydig cells by reducing the expression of StAR through a model of action involving oxidative stress.
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Affiliation(s)
- Zhimin Shi
- Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
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Mitochondrial ion transport pathways: role in metabolic diseases. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2010; 1797:832-8. [PMID: 20044972 DOI: 10.1016/j.bbabio.2009.12.017] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2009] [Revised: 12/16/2009] [Accepted: 12/21/2009] [Indexed: 12/22/2022]
Abstract
Mitochondria are the central coordinators of energy metabolism and alterations in their function and number have long been associated with metabolic disorders such as obesity, diabetes and hyperlipidemias. Since oxidative phosphorylation requires an electrochemical gradient across the inner mitochondrial membrane, ion channels in this membrane certainly must play an important role in the regulation of energy metabolism. However, in many experimental settings, the relationship between the activity of mitochondrial ion transport and metabolic disorders is still poorly understood. This review briefly summarizes some aspects of mitochondrial H+ transport (promoted by uncoupling proteins, UCPs), Ca2+ and K+ uniporters which may be determinant in metabolic disorders.
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Chinopoulos C, Adam-Vizi V. Mitochondria as ATP consumers in cellular pathology. Biochim Biophys Acta Mol Basis Dis 2009; 1802:221-7. [PMID: 19715757 DOI: 10.1016/j.bbadis.2009.08.008] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2009] [Revised: 07/17/2009] [Accepted: 08/17/2009] [Indexed: 12/21/2022]
Abstract
ATP provided by oxidative phosphorylation supports highly complex and energetically expensive cellular processes. Yet, in several pathological settings, mitochondria could revert to ATP consumption, aggravating an existing cellular pathology. Here we review (i) the pathological conditions leading to ATP hydrolysis by the reverse operation of the mitochondrial F(o)F(1)-ATPase, (ii) molecular and thermodynamic factors influencing the directionality of the F(o)F(1)-ATPase, (iii) the role of the adenine nucleotide translocase as the intermediary adenine nucleotide flux pathway between the cytosol and the mitochondrial matrix when mitochondria become ATP consumers, (iv) the role of the permeability transition pore in bypassing the ANT, thereby allowing the flux of ATP directly to the hydrolyzing F(o)F(1)-ATPase, (v) the impact of the permeability transition pore on glycolytic ATP production, and (vi) endogenous and exogenous interventions for limiting ATP hydrolysis by the mitochondrial F(o)F(1)-ATPase.
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Affiliation(s)
- Christos Chinopoulos
- Department of Medical Biochemistry, Semmelweis University, Neurobiochemical Group, Hungarian Academy of Sciences, Budapest, Hungary
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Kowaltowski AJ, de Souza-Pinto NC, Castilho RF, Vercesi AE. Mitochondria and reactive oxygen species. Free Radic Biol Med 2009; 47:333-43. [PMID: 19427899 DOI: 10.1016/j.freeradbiomed.2009.05.004] [Citation(s) in RCA: 789] [Impact Index Per Article: 52.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2009] [Revised: 04/29/2009] [Accepted: 05/06/2009] [Indexed: 01/02/2023]
Abstract
Mitochondria are a quantitatively relevant source of reactive oxygen species (ROS) in the majority of cell types. Here we review the sources and metabolism of ROS in this organelle, including the conditions that regulate the production of these species, such as mild uncoupling, oxygen tension, respiratory inhibition, Ca2+ and K+ transport, and mitochondrial content and morphology. We discuss substrate-, tissue-, and organism-specific characteristics of mitochondrial oxidant generation. Several aspects of the physiological and pathological roles of mitochondrial ROS production are also addressed.
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Affiliation(s)
- Alicia J Kowaltowski
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
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Vajda S, Mándi M, Konràd C, Kiss G, Ambrus A, Adam-Vizi V, Chinopoulos C. A re-evaluation of the role of matrix acidification in uncoupler-induced Ca2+release from mitochondria. FEBS J 2009; 276:2713-24. [DOI: 10.1111/j.1742-4658.2009.06995.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Chapter 23 Quantification of Superoxide Production by Mouse Brain and Skeletal Muscle Mitochondria. Methods Enzymol 2009; 456:419-37. [DOI: 10.1016/s0076-6879(08)04423-6] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
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