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Horváth G, Sváb G, Komlódi T, Ravasz D, Kacsó G, Doczi J, Chinopoulos C, Ambrus A, Tretter L. Reverse and Forward Electron Flow-Induced H2O2 Formation Is Decreased in α-Ketoglutarate Dehydrogenase (α-KGDH) Subunit (E2 or E3) Heterozygote Knock Out Animals. Antioxidants (Basel) 2022; 11:antiox11081487. [PMID: 36009207 PMCID: PMC9404749 DOI: 10.3390/antiox11081487] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Revised: 07/20/2022] [Accepted: 07/25/2022] [Indexed: 12/04/2022] Open
Abstract
α-ketoglutarate dehydrogenase complex (KGDHc), or 2-oxoglutarate dehydrogenase complex (OGDHc) is a rate-limiting enzyme in the tricarboxylic acid cycle, that has been identified in neurodegenerative diseases such as in Alzheimer’s disease. The aim of the present study was to establish the role of the KGDHc and its subunits in the bioenergetics and reactive oxygen species (ROS) homeostasis of brain mitochondria. To study the bioenergetic profile of KGDHc, genetically modified mouse strains were used having a heterozygous knock out (KO) either in the dihydrolipoyl succinyltransferase (DLST+/−) or in the dihydrolipoyl dehydrogenase (DLD+/−) subunit. Mitochondrial oxygen consumption, hydrogen peroxide (H2O2) production, and expression of antioxidant enzymes were measured in isolated mouse brain mitochondria. Here, we demonstrate that the ADP-stimulated respiration of mitochondria was partially arrested in the transgenic animals when utilizing α-ketoglutarate (α-KG or 2-OG) as a fuel substrate. Succinate and α-glycerophosphate (α-GP), however, did not show this effect. The H2O2 production in mitochondria energized with α-KG was decreased after inhibiting the adenine nucleotide translocase and Complex I (CI) in the transgenic strains compared to the controls. Similarly, the reverse electron transfer (RET)-evoked H2O2 formation supported by succinate or α-GP were inhibited in mitochondria isolated from the transgenic animals. The decrease of RET-evoked ROS production by DLST+/− or DLD+/− KO-s puts the emphasis of the KGDHc in the pathomechanism of ischemia-reperfusion evoked oxidative stress. Supporting this notion, expression of the antioxidant enzyme glutathione peroxidase was also decreased in the KGDHc transgenic animals suggesting the attenuation of ROS-producing characteristics of KGDHc. These findings confirm the contribution of the KGDHc to the mitochondrial ROS production and in the pathomechanism of ischemia-reperfusion injury.
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Regulation of human 4-hydroxy-2-oxoglutarate aldolase by pyruvate and α-ketoglutarate: implications for primary hyperoxaluria type-3. Biochem J 2020; 476:3369-3383. [PMID: 31696211 DOI: 10.1042/bcj20190548] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 10/16/2019] [Accepted: 10/18/2019] [Indexed: 11/17/2022]
Abstract
4-hydroxy-2-oxoglutarate aldolase (HOGA1) is a mitochondrial enzyme that plays a gatekeeper role in hydroxyproline metabolism. Its loss of function in humans causes primary hyperoxaluria type 3 (PH3), a rare condition characterised by excessive production of oxalate. In this study, we investigated the significance of the associated oxaloacetate decarboxylase activity which is also catalysed by HOGA1. Kinetic studies using the recombinant human enzyme (hHOGA1) and active site mutants showed both these dual activities utilise the same catalytic machinery with micromolar substrate affinities suggesting that both are operative in vivo. Biophysical and structural studies showed that pyruvate was a competitive inhibitor with an inhibition constant in the micromolar range. By comparison α-ketoglutarate was a weak inhibitor with an inhibition constant in the millimolar range and could only be isolated as an adduct with the active site Lys196 in the presence of sodium borohydride. These studies suggest that pyruvate inhibits HOGA1 activity during gluconeogenesis. We also propose that loss of HOGA1 function could increase oxalate production in PH3 by decreasing pyruvate availability and metabolic flux through the Krebs cycle.
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Characteristic analysis of Zenker's diverticulum incidentally detected on multimodal neck ultrasound. J Med Ultrason (2001) 2019; 47:279-285. [PMID: 31848772 DOI: 10.1007/s10396-019-00992-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Accepted: 11/13/2019] [Indexed: 10/25/2022]
Abstract
PURPOSE Zenker's diverticulum (ZD) incidentally detected on neck ultrasound (US) could be easily misdiagnosed as a thyroid nodule and unnecessarily removed by surgical operation. It is a critical issue to identify the characteristics of ZD in clinical practice. METHODS We reported 10 cases of ZD diagnosed using multimodal US, and discussed the features of its multimodal US images extracted from grayscale sonograms, color Doppler flow imaging (CDFI), three-dimensional US (3D-US), and contrast-enhanced US (CEUS). RESULTS All lesions were heterogeneous in the posterior of the left thyroid. CDFI showed no blood flow within the lesions. The shapes and internal echoes of the masses changed when patients swallowed or drank. Performing CEUS or 3D-US for those with atypical US findings was complementary to make the final diagnosis. Importantly, multimodal US helped to diagnose suspected small lesions in three cases in which the barium esophagram tests proved negative. CONCLUSIONS The US features of ZD detected by multiple modes of US can help in the collection of comprehensive imaging information on ZD, which should be used proactively to facilitate the correct diagnosis and to avoid misdiagnosis of ZD.
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Hamilton J, Brustovetsky T, Brustovetsky N. Mutant huntingtin fails to directly impair brain mitochondria. J Neurochem 2019; 151:716-731. [PMID: 31418857 PMCID: PMC6917837 DOI: 10.1111/jnc.14852] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Revised: 07/17/2019] [Accepted: 08/06/2019] [Indexed: 12/15/2022]
Abstract
Although the mechanisms by which mutant huntingtin (mHtt) results in Huntington's disease (HD) remain unclear, mHtt-induced mitochondrial defects were implicated in HD pathogenesis. The effect of mHtt could be mediated by transcriptional alterations, by direct interaction with mitochondria, or by both. In the present study, we tested a hypothesis that mHtt directly damages mitochondria. To test this hypothesis, we applied brain cytosolic fraction from YAC128 mice, containing mHtt, to brain non-synaptic and synaptic mitochondria from wild-type mice and assessed mitochondrial respiration with a Clark-type oxygen electrode, membrane potential and Ca2+ uptake capacity with tetraphenylphosphonium (TPP+ )- and Ca2+ -sensitive electrodes, respectively, and, reactive oxygen species production with Amplex Red assay. The amount of mHtt bound to mitochondria following incubation with mHtt-containing cytosolic fraction was greater than the amount of mHtt bound to brain mitochondria isolated from YAC128 mice. Despite mHtt binding to wild-type mitochondria, no abnormalities in mitochondrial functions were detected. This is consistent with our previous results demonstrating the lack of defects in brain mitochondria isolated from R6/2 and YAC128 mice. This, however, could be because of partial loss of mitochondrially bound mHtt during the isolation procedure. Consequently, we increased the amount of mitochondrially bound mHtt by incubating brain non-synaptic and synaptic mitochondria isolated from YAC128 mice with mHtt-containing cytosolic fraction. Despite the enrichment of YAC128 brain mitochondria with mHtt, mitochondrial functions (respiration, membrane potential, reactive oxygen species production, Ca2+ uptake capacity) remained unchanged. Overall, our results suggest that mHtt does not directly impair mitochondrial functions, arguing against the involvement of this mechanism in HD pathogenesis. Open Science: This manuscript was awarded with the Open Materials Badge For more information see: https://cos.io/our-services/open-science-badges/.
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Affiliation(s)
- James Hamilton
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN
| | - Tatiana Brustovetsky
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN
| | - Nickolay Brustovetsky
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN
- Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN
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Hamilton J, Brustovetsky T, Rysted JE, Lin Z, Usachev YM, Brustovetsky N. Deletion of mitochondrial calcium uniporter incompletely inhibits calcium uptake and induction of the permeability transition pore in brain mitochondria. J Biol Chem 2018; 293:15652-15663. [PMID: 30154242 DOI: 10.1074/jbc.ra118.002926] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Revised: 08/22/2018] [Indexed: 11/06/2022] Open
Abstract
Ca2+ influx into mitochondria is mediated by the mitochondrial calcium uniporter (MCU), whose identity was recently revealed as a 40-kDa protein that along with other proteins forms the mitochondrial Ca2+ uptake machinery. The MCU is a Ca2+-conducting channel spanning the inner mitochondrial membrane. Here, deletion of the MCU completely inhibited Ca2+ uptake in liver, heart, and skeletal muscle mitochondria. However, in brain nonsynaptic and synaptic mitochondria from neuronal somata/glial cells and nerve terminals, respectively, the MCU deletion slowed, but did not completely block, Ca2+ uptake. Under resting conditions, brain MCU-KO mitochondria remained polarized, and in brain MCU-KO mitochondria, the electrophoretic Ca2+ ionophore ETH129 significantly accelerated Ca2+ uptake. The residual Ca2+ uptake in brain MCU-KO mitochondria was insensitive to inhibitors of mitochondrial Na+/Ca2+ exchanger and ryanodine receptor (CGP37157 and dantrolene, respectively), but was blocked by the MCU inhibitor Ru360. Respiration of WT and MCU-KO brain mitochondria was similar except that for mitochondria that oxidized pyruvate and malate, Ca2+ more strongly inhibited respiration in WT than in MCU-KO mitochondria. Of note, the MCU deletion significantly attenuated but did not completely prevent induction of the permeability transition pore (PTP) in brain mitochondria. Expression level of cyclophilin D and ATP content in mitochondria, two factors that modulate PTP induction, were unaffected by MCU-KO, whereas ADP was lower in MCU-KO than in WT brain mitochondria. Our results suggest the presence of an MCU-independent Ca2+ uptake pathway in brain mitochondria that mediates residual Ca2+ influx and induction of PTP in a fraction of the mitochondrial population.
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Affiliation(s)
| | | | - Jacob E Rysted
- the Department of Pharmacology, University of Iowa Carver College of Medicine, Iowa City, Iowa 52242
| | - Zhihong Lin
- the Department of Pharmacology, University of Iowa Carver College of Medicine, Iowa City, Iowa 52242
| | - Yuriy M Usachev
- the Department of Pharmacology, University of Iowa Carver College of Medicine, Iowa City, Iowa 52242
| | - Nickolay Brustovetsky
- From the Department of Pharmacology and Toxicology and .,the Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, Indiana 46202 and
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Hamilton J, Brustovetsky T, Brustovetsky N. Oxidative metabolism and Ca 2+ handling in striatal mitochondria from YAC128 mice, a model of Huntington's disease. Neurochem Int 2017; 109:24-33. [PMID: 28062223 PMCID: PMC5495615 DOI: 10.1016/j.neuint.2017.01.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Revised: 12/29/2016] [Accepted: 01/02/2017] [Indexed: 01/30/2023]
Abstract
The mechanisms implicated in the pathology of Huntington's disease (HD) remain not completely understood, although dysfunction of mitochondrial oxidative metabolism and Ca2+ handling have been suggested as contributing factors. However, in our previous studies with mitochondria isolated from the whole brains of HD mice, we found no evidence for defects in mitochondrial respiration and Ca2+ handling. In the present study, we used the YAC128 mouse model of HD to evaluate the effect of mHtt on respiratory activity and Ca2+ uptake capacity of mitochondria isolated from the striatum, the most vulnerable brain region in HD. Isolated, Percoll-gradient purified striatal mitochondria from YAC128 mice were free of cytosolic and ER contaminations, but retained attached mHtt. Both nonsynaptic and synaptic striatal mitochondria isolated from early symptomatic 2-month-old YAC128 mice had similar respiratory rates and Ca2+ uptake capacities compared with mitochondria from wild-type FVB/NJ mice. Consistent with the lack of difference in mitochondrial respiration, we found that the expression of several nuclear-encoded proteins in striatal mitochondria was similar between wild-type and YAC128 mice. Taken together, our data demonstrate that mHtt does not alter respiration and Ca2+ uptake capacity in striatal mitochondria isolated from YAC128 mice, suggesting that respiratory defect and Ca2+ uptake deficiency most likely do not contribute to striatal pathology associated with HD.
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Affiliation(s)
- James Hamilton
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN, United States
| | - Tatiana Brustovetsky
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN, United States
| | - Nickolay Brustovetsky
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN, United States; Stark Neuroscience Research Institute, Indiana University School of Medicine, Indianapolis, IN, United States.
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Hamilton J, Pellman JJ, Brustovetsky T, Harris RA, Brustovetsky N. Oxidative metabolism in YAC128 mouse model of Huntington's disease. Hum Mol Genet 2015; 24:4862-78. [PMID: 26041817 DOI: 10.1093/hmg/ddv209] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Accepted: 06/01/2015] [Indexed: 12/15/2022] Open
Abstract
Alterations in oxidative metabolism are considered to be one of the major contributors to Huntington's disease (HD) pathogenesis. However, existing data about oxidative metabolism in HD are contradictory. Here, we investigated the effect of mutant huntingtin (mHtt) on oxidative metabolism in YAC128 mice. Both mHtt and wild-type huntingtin (Htt) were associated with mitochondria and the amount of bound Htt was four-times higher than the amount of bound mHtt. Percoll gradient-purified brain synaptic and non-synaptic mitochondria as well as unpurified brain, liver and heart mitochondria, isolated from 2- and 10-month-old YAC128 mice and age-matched WT littermates had similar respiratory rates. There was no difference in mitochondrial membrane potential or ADP and ATP levels. Expression of selected nuclear-encoded mitochondrial proteins in 2- and 10-month-old YAC128 and WT mice was similar. Cultured striatal and cortical neurons from YAC128 and WT mice had similar respiratory and glycolytic activities as measured with Seahorse XF24 analyzer in medium containing 10 mm glucose and 15 mm pyruvate. In the medium with 2.5 mm glucose, YAC128 striatal neurons had similar respiration, but slightly lower glycolytic activity. Striatal neurons had lower maximal respiration compared with cortical neurons. In vivo experiments with YAC128 and WT mice showed similar O2 consumption, CO2 release, physical activity, food consumption and fasted blood glucose. However, YAC128 mice were heavier and had more body fat compared with WT mice. Overall, our data argue against respiratory deficiency in YAC128 mice and, consequently, suggest that mitochondrial respiratory dysfunction is not essential for HD pathogenesis.
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Affiliation(s)
| | | | | | - Robert A Harris
- Department of Biochemistry and Molecular Biology and Richard L. Roudebush VA Medical Center, Indianapolis, IN, USA
| | - Nickolay Brustovetsky
- Department of Pharmacology and Toxicology, Department of Stark Neuroscience Research Institute, Indiana University School of Medicine, Indianapolis, IN 46202, USA and
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Kondrashova MN, Zakharchenko MV, Khunderyakova NV, Fedotcheva NI, Litvinova EG, Romanova OI, Gulayev AA. States of succinate dehydrogenase in the organism: Dormant vs. hyperactive (pushed out of equilibrium). Biophysics (Nagoya-shi) 2013. [DOI: 10.1134/s0006350913010089] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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Burst of succinate dehydrogenase and α-ketoglutarate dehydrogenase activity in concert with the expression of genes coding for respiratory chain proteins underlies short-term beneficial physiological stress in mitochondria. Int J Biochem Cell Biol 2012; 45:190-200. [PMID: 22814171 DOI: 10.1016/j.biocel.2012.07.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2012] [Revised: 06/28/2012] [Accepted: 07/01/2012] [Indexed: 11/20/2022]
Abstract
Conditions for the realization in rats of moderate physiological stress (PHS) (30-120 min) were selected, which preferentially increase adaptive restorative processes without adverse responses typical of harmful stress (HST). The succinate dehydrogenase (SDH) and α-ketoglutarate dehydrogenase (KDH) activity and the formation of reactive oxygen species (ROS) in mitochondria were measured in lymphocytes by the cytobiochemical method, which detects the regulation of mitochondria in the organism with high sensitivity. These mitochondrial markers undergo an initial 10-20-fold burst of activity followed by a decrease to a level exceeding the quiescent state 2-3-fold by 120 min of PHS. By 30-60 min, the rise in SDH activity was greater than in KDH activity, while the activity of KDH prevailed over that of SDH by 120 min. The attenuation of SDH hyperactivity during PHS occurs by a mechanism other than oxaloacetate inhibition developed under HST. The dynamics of SDH and KDH activity corresponds to the known physiological replacement of adrenergic regulation by cholinergic during PHS, which is confirmed here by mitochondrial markers because their activity reflects these two types of nerve regulation, respectively. The domination of cholinergic regulation provides the overrestoration of expenditures for activity. In essence, this phenomenon corresponds to the training of the organism. It was first revealed in mitochondria after a single short-time stress episode. The burst of ROS formation was congruous with changes in SDH and KDH activity, as well as in ucp2 and cox3 expression, while the activity of SDH was inversely dependent on the expression of the gene of its catalytic subunit in the spleen. As the SDH activity enhanced, the expression of the succinate receptor decreased with subsequent dramatic rise when the activity was becoming lower. This article is part of a Directed Issue entitled: Bioenergetic dysfunction, adaption and therapy.
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Inhibitors of succinate: quinone reductase/Complex II regulate production of mitochondrial reactive oxygen species and protect normal cells from ischemic damage but induce specific cancer cell death. Pharm Res 2011; 28:2695-730. [PMID: 21863476 DOI: 10.1007/s11095-011-0566-7] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2011] [Accepted: 08/10/2011] [Indexed: 12/23/2022]
Abstract
Succinate:quinone reductase (SQR) of Complex II occupies a unique central point in the mitochondrial respiratory system as a major source of electrons driving reactive oxygen species (ROS) production. It is an ideal pharmaceutical target for modulating ROS levels in normal cells to prevent oxidative stress-induced damage or alternatively,increase ROS in cancer cells, inducing cell death.The value of drugs like diazoxide to prevent ROS production,protecting normal cells, whereas vitamin E analogues promote ROS in cancer cells to kill them is highlighted. As pharmaceuticals these agents may prevent degenerative disease and their modes of action are presently being fully explored. The evidence that SDH/Complex II is tightly coupled to the NADH/NAD+ ratio in all cells,impacted by the available supplies of Krebs cycle intermediates as essential NAD-linked substrates, and the NAD+-dependent regulation of SDH/Complex II are reviewed, as are links to the NAD+-dependent dehydrogenases, Complex I and the E3 dihiydrolipoamide dehydrogenase to produce ROS. This review collates and discusses diverse sources of information relating to ROS production in different biological systems, focussing on evidence for SQR as the main source of ROS production in mitochondria, particularly its relevance to protection from oxidative stress and to the mitochondrial-targeted anti cancer drugs (mitocans) as novel cancer therapies [corrected].
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Preservation of the in vivo state of mitochondrial network for ex vivo physiological study of mitochondria. Int J Biochem Cell Biol 2009; 41:2036-50. [DOI: 10.1016/j.biocel.2009.04.020] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2008] [Revised: 04/19/2009] [Accepted: 04/21/2009] [Indexed: 11/22/2022]
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12
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Belosludtsev KN, Saris NEL, Belosludtseva NV, Trudovishnikov AS, Lukyanova LD, Mironova GD. Physiological aspects of the mitochondrial cyclosporin A-insensitive palmitate/Ca2+-induced pore: tissue specificity, age profile and dependence on the animal’s adaptation to hypoxia. J Bioenerg Biomembr 2009; 41:395-401. [PMID: 19685177 DOI: 10.1007/s10863-009-9230-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2009] [Accepted: 07/30/2009] [Indexed: 11/28/2022]
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13
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Moser MD, Matsuzaki S, Humphries KM. Inhibition of succinate-linked respiration and complex II activity by hydrogen peroxide. Arch Biochem Biophys 2009; 488:69-75. [PMID: 19540189 DOI: 10.1016/j.abb.2009.06.009] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2009] [Revised: 06/11/2009] [Accepted: 06/13/2009] [Indexed: 11/26/2022]
Abstract
Hydrogen peroxide produced from electron transport chain derived superoxide is a relatively mild oxidant, and as such, the majority of mitochondrial enzyme activities are impervious to physiological concentrations. Previous studies, however, have suggested that complex II (succinate dehydrogenase) is sensitive to H(2)O(2)-mediated inhibition. Nevertheless, the effects of H(2)O(2) on succinate-linked respiration and complex II activity have not been examined in intact mitochondria. Results presented indicate that H(2)O(2) inhibits succinate-linked state 3 mitochondrial respiration in a concentration dependent manner. H(2)O(2) has no effect on complex II activity during state 2 respiration, but inhibits activity during state 3. It was found that conditions which prevent oxaloacetate accumulation during state 3 respiration, such as inclusion of rotenone, glutamate, or ATP, blunted the effect of H(2)O(2) on succinate-linked respiration and complex II activity. It is concluded that H(2)O(2) inhibits succinate-linked respiration indirectly by sustaining and enhancing oxaloacetate-mediated inactivation of complex II.
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Affiliation(s)
- Michelle D Moser
- Free Radical Biology and Aging Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA
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Belosludtsev K, Saris NEL, Andersson LC, Belosludtseva N, Agafonov A, Sharma A, Moshkov DA, Mironova GD. On the mechanism of palmitic acid-induced apoptosis: the role of a pore induced by palmitic acid and Ca2+ in mitochondria. J Bioenerg Biomembr 2006; 38:113-20. [PMID: 16847595 DOI: 10.1007/s10863-006-9010-9] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2006] [Accepted: 03/12/2006] [Indexed: 01/22/2023]
Abstract
Palmitic acid (Pal) is known to promote apoptosis (Sparagna G et al (2000) Am J Physiol Heart Circ Physiol 279: H2124-H2132) and its amount in blood and mitochondria increases under some pathological conditions. Yet, the mechanism of the proapoptotic action of Pal has not been elucidated. We present evidence for the involvement of the mitochondrial cyclosporin A-insensitive pore induced by Pal/Ca(2+) complexes in the apoptotic process. Opening of this pore led to a fall of the mitochondrial membrane potential and the release of the proapoptotic signal cytochrome c. The addition of cytochrome c prevented these effects and recovered membrane potential, which is in contrast to the cyclosporin A-sensitive mitochondrial permeability transition pore. Oleic and linoleic acids prevented the Pal/Ca(2+)-induced pore opening in the intact mitochondria, this directly and significantly correlating with the effect of these fatty acids on Pal-induced apoptosis in cells (Hardy S et al (2003) J Biol Chem 278: 31861-31870). The specific probe for cardiolipin, 10-N-nonyl acridine orange, inhibited formation of this pore.
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Affiliation(s)
- Konstantin Belosludtsev
- Institute of Theoretical and Experimental Biophysics RAS, Pushchino, Moscow Region, 142290, Russia
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Sultan A, Sokolove PM. Palmitic Acid Opens a Novel Cyclosporin A-Insensitive Pore in the Inner Mitochondrial Membrane. Arch Biochem Biophys 2001; 386:37-51. [PMID: 11360999 DOI: 10.1006/abbi.2000.2194] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
An assortment of agents can induce mitochondria to undergo a permeability transition, which results in the inner mitochondrial membrane becoming nonselectively permeable to small (<1500 Da) solutes. This mitochondrial permeability transition (MPT) is characterized by a strict dependence on matrix Ca2+ and sensitivity to cyclosporin A (CsA). However, it is becoming increasingly clear that other experimental conditions can elicit increases in mitochondrial permeability that are distinct from this classic MPT. For example, butylated hydroxytoluene (BHT; Sokolove, P. M., and Haley, L. M. (1996) J. Bioenerg. Biomembr. 28, 199-206) and signal peptides (Sokolove, P. M., and Kinnally, K. W. (1996) Arch. Biochem. Biophys. 336, 69-76) promote increases in mitochondrial permeability that are CsA-insensitive. It has been suggested (Gudz, T., Eriksson, O., Kushnareva, Y., Saris, N.-E., and Novgorodov, S. A. (1997) Arch. Biochem. Biophys. 342, 143-156) that BHT might be opening a CsA-insensitive pore by increasing phospholipase A2 activity and thereby producing an accumulation of free fatty acids and lysophospholipids. We have therefore examined the effect of the saturated free fatty acid, palmitic acid (PA), on the permeability of isolated rat liver mitochondria. The following results were obtained: (1) In the absence of additional triggers, PA (20-60 microM) induced concentration-dependent, CsA-insensitive mitochondrial swelling. (2) Swelling required mitochondrial energization. (3) PA-induced swelling was fast and occurred without a lag. (4) Both Ca2+ and Sr2+ supported PA-induced swelling; the site of cation action was the matrix. (5) EGTA and BSA were potent inhibitors of PA-induced swelling. (6) PA opened a pore rather than disrupting mitochondrial membrane structure. (7) The pore opened by PA closed spontaneously. These results suggest that palmitic acid promotes a nonclassic permeability increase that is clearly distinguishable from the occurrence of the MPT.
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Affiliation(s)
- A Sultan
- Department of Pharmacology & Experimental Therapeutics, University of Maryland School of Medicine, Baltimore 21201, USA
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Abstract
Isolated brain mitochondria were examined for their responses to calcium challenges under varying conditions. Mitochondrial membrane potential was monitored by following the distribution of tetraphenylphosphonium ions in the mitochondrial suspension, mitochondrial swelling by observing absorbance changes, calcium accumulation by an external calcium electrode, and oxygen consumption with an oxygen electrode. Both the extent and rate of calcium-induced mitochondrial swelling and depolarization varied greatly depending on the energy source provided to the mitochondria. When energized with succinate plus glutamate, after a calcium challenge, CNS mitochondria depolarized transiently, accumulated substantial calcium, and increased in volume, characteristic of a mitochondrial permeability transition. When energized with 3 mM succinate, CNS mitochondria maintained a sustained calcium-induced depolarization without appreciable swelling and were slow to accumulate calcium. Maximal oxygen consumption was also restricted under these conditions, preventing the electron transport chain from compensating for this increased proton permeability. In 3 mM succinate, cyclosporin A and ADP plus oligomycin restored potential and calcium uptake. This low conductance permeability was not effected by bongkrekic acid or carboxyatractylate, suggesting that the adenine nucleotide translocator was not directly involved. Fura-2FF measurements of [Ca(2+)](i) suggest that in cultured hippocampal neurons glutamate-induced increases reached tens of micromolar levels, approaching those used with mitochondria. We propose that in the restricted substrate environment, Ca(2+) activated a low-conductance permeability pathway responsible for the sustained mitochondrial depolarization.
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Khazanov VA, Poborsky AN, Kondrashova MN. Air saturation of the medium reduces the rate of phosphorylating oxidation of succinate in isolated mitochondria. FEBS Lett 1992; 314:264-6. [PMID: 1468556 DOI: 10.1016/0014-5793(92)81485-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Rat brain mitochondria were isolated and their respiration was polarographically measured without contact with air oxygen. Gas-saturated experimental mixtures close to the in vivo partial oxygen pressure (normoxic) were compared with the air-saturated, i.e. hyperoxic, mixtures. The rate of phosphorylating oxidation of added succinate under normoxic conditions was found to be 70-100% higher compared with hyperoxic ones. The addition of succinate dehydrogenase activators results in a more than two-fold stronger stimulation of succinate oxidation under normoxia than under hyperoxia. Thiol group donors are shown to stimulate respiration under hyperoxia and not under normoxia. Hyperoxic conditions prevented oxidation of the low succinate concentrations corresponding to the physiological ones.
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Affiliation(s)
- V A Khazanov
- Institute of Pharmacology, Russian Academy of Medical Science, Tomsk
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Nishikawa M, Yamashita Y, Maeda Y, Sakakibara E, Furukawa T. Stimulation of guinea pig brain mitochondrial respiration by ifenprodil. Toxicol Appl Pharmacol 1980; 53:501-9. [PMID: 7385247 DOI: 10.1016/0041-008x(80)90362-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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Miranda M, Botti D, Pantani C. Are some interactions between NADH oxidase and succinate oxidase in beef heart non-phosphorylating submitochondrial particles artifacts? EXPERIENTIA 1977; 33:849-51. [PMID: 19278 DOI: 10.1007/bf01951237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Passarella S, Palmieri F, Quagliariello E. The transport of oxaloacetate in isolated mitochondria. Arch Biochem Biophys 1977; 180:160-8. [PMID: 856040 DOI: 10.1016/0003-9861(77)90020-0] [Citation(s) in RCA: 38] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Passarella S, Quagliariello E. The citric cycle intermediates transport in rat liver mitochondria. Biochimie 1976; 58:989-1001. [PMID: 990338 DOI: 10.1016/s0300-9084(76)80287-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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22
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Lopes-Cardozo M, van den Bergh SG. Ketogenesis in isolated rat-liver mitochondria. IV. Oxaloacetate decarboxylation: consequences for metabolic calculations. BIOCHIMICA ET BIOPHYSICA ACTA 1974; 357:193-203. [PMID: 4420547 DOI: 10.1016/0005-2728(74)90060-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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23
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Wojtczak AB, Walajtys E. Mitochondrial oxaloacetate decarboxylase from rat liver. BIOCHIMICA ET BIOPHYSICA ACTA 1974; 347:168-82. [PMID: 4407365 DOI: 10.1016/0005-2728(74)90042-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Dohm GL, Tapscott EB. Oxaloacetate inhibition of succinate oxidation in tightly coupled liver mitochondria with ferricyanide as an electron acceptor. Biochem Biophys Res Commun 1973; 52:246-53. [PMID: 4712193 DOI: 10.1016/0006-291x(73)90980-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Gimpel JA, de Haan EJ, Tager JM. Permeability of isolated mitochondria to oxaloacetate. BIOCHIMICA ET BIOPHYSICA ACTA 1973; 292:582-91. [PMID: 4145178 DOI: 10.1016/0005-2728(73)90006-6] [Citation(s) in RCA: 66] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Abstract
Two kinetically distinct states of succinate oxidase have been detected in the mitochondria of Neruospora crassa. One state has a K(m) for succinate of 4.1 x 10(-3)m, and the other has a K(m) for succinate of 3.5 x 10(-4)m. The high K(m) state was found in freshly extracted mitochondria from either 20- or 72-hr mycelium. However, the succinate oxidase activity in mitochondria from 20-hr mycelium rapidly deteriorated in vitro, leaving a stable residual activity with the lower K(m) for succinate. Adenosine triphosphate (ATP) plus Mg(2+) stabilized the high K(m) state in these preparations. The high K(m) state of succinate oxidase was further characterized by a two- to threefold increase in activity over the pH range 6.6 to 8.0 and by classical competitive inhibition by fumarate and malonate. By contrast, the low K(m) state of succinate oxidase showed a relatively flat response to pH over the range 6.6 to 8.0 and a nonclassical pattern of inhibition by fumarate and malonate, as shown by nonlinear plots of reciprocal velocity versus reciprocal substrate concentration in the presence of inhibitor or reciprocal velocity versus inhibitor concentration at fixed substrate concentrations. The relationship of mycelial age to the in vitro stability of succinate oxidase is considered with reference to probable changes in the relative pool sizes of extra- and intramitochondrial ATP in response to changes in the rate of glycolysis.
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Gaensslen RE, McCarty RE. Determination of solute accumulation in chloroplasts by rapid centrifugal transfer through silicone fluid layers. Anal Biochem 1972; 48:504-14. [PMID: 5070044 DOI: 10.1016/0003-2697(72)90105-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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de Gómez-Puyou MT, Chávez E, Freites D, Gómez-Puyou A. On the regulation of succinate dehydrogenase in brain mitochondria. FEBS Lett 1972; 22:57-60. [PMID: 11946560 DOI: 10.1016/0014-5793(72)80218-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- M T. de Gómez-Puyou
- Departamento de Bioquímica, Facultad de Medicina, Ciudad Universitária, Apartado Postal 70159, México, D.F., México
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Rasmussen UF. The energy requirement for activation of succinate metabolism in intact heart mitochondria. FEBS Lett 1972; 21:173-178. [PMID: 11946503 DOI: 10.1016/0014-5793(72)80130-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- U F. Rasmussen
- Institute of Biological Chemistry A, University of Copenhagen, The August Krogh Institute, 13 University Park, DK 2100, Copenhagen, Denmark
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Abstract
1. Utilization of propionate by sheep liver mitochondria was stimulated equally by pyruvate or alpha-oxoglutarate, with formation predominantly of malate. Pyruvate increased conversion of propionate carbon into citrate, whereas alpha-oxoglutarate increased formation of phosphoenolpyruvate. The fraction of metabolized propionate converted into phosphoenolpyruvate was about 17% in the presence or absence of alpha-oxoglutarate and about 7% in the presence of pyruvate. Pyruvate consumption was inhibited by 80% by 5mm-propionate. 2. Compared with rat liver, sheep liver was characterized by very high activities of phosphoenolpyruvate carboxykinase and moderately high activities of aconitase in the mitochondria and by low activities of ;malic' enzyme, pyruvate kinase and lactate dehydrogenase in the cytosol. Activities of phosphoenolpyruvate carboxy-kinase were similar in liver cytosol from rats and sheep. Activities of malate dehydrogenase and NADP-linked isocitrate dehydrogenase in sheep liver were about half those in rat liver. 3. The phosphate-dicarboxylate antiport was active in sheep liver mitochondria, but compared with rat liver mitochondria the citrate-malate antiport showed only low activity and mitochondrial aconitase was relatively inaccessible to external citrate. The rate of swelling of mitochondria induced by phosphate in solutions of ammonium malate was inversely related to the concentration of malate. 4. The results are discussed in relation to gluconeogenesis from propionate in sheep liver. It is proposed that propionate is converted into malate by the mitochondria and the malate is converted into phosphoenolpyruvate by enzymes in the cytosol. In this way sufficient NADH would be generated in the cytosol to convert the phosphoenolpyruvate into glucose.
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Volkov MS, Shmeleva LT, Tsvetova GM. Effect of glutamic acid and hypoxia on transaminase activity in the blood and tissues. Bull Exp Biol Med 1971. [DOI: 10.1007/bf00808482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Bachmann E, Golberg L. Reappraisal of the toxicology of ethylene glycol. 3. Mitochondrial effects. FOOD AND COSMETICS TOXICOLOGY 1971; 9:39-55. [PMID: 4996515 DOI: 10.1016/s0015-6264(71)80115-3] [Citation(s) in RCA: 38] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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Bohnensack R, Kunz W. [Investigation of the penetration of oxaloacetate into rat liver mitochondria]. BIOCHIMICA ET BIOPHYSICA ACTA 1971; 226:33-41. [PMID: 4323696 DOI: 10.1016/0005-2728(71)90175-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Lagunas R, McLean P, Greenbaum AL. The effect of raising the NAD+ content on the pathways of carbohydrate metabolism and lipogenesis in rat liver. EUROPEAN JOURNAL OF BIOCHEMISTRY 1970; 15:179-90. [PMID: 4321379 DOI: 10.1111/j.1432-1033.1970.tb00993.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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36
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Tuena M, Gómez-Puyou A, Peña A, Chávez E, Sandoval F. Effect of ATP on the oxidation of succinate in rat brain mitochondria. EUROPEAN JOURNAL OF BIOCHEMISTRY 1969; 11:283-90. [PMID: 5360409 DOI: 10.1111/j.1432-1033.1969.tb00771.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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37
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Wojtczak L, Wojtczak AB, Ernster L. The inhibition of succinate dehydrogenase by oxalacetate. BIOCHIMICA ET BIOPHYSICA ACTA 1969; 191:10-21. [PMID: 5823490 DOI: 10.1016/0005-2744(69)90310-6] [Citation(s) in RCA: 52] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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38
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Oestreicher AB, Van den Bergh SG, Slater EC. The inhibition by 2,4-dinitrophenol of the removal of oxaloacetate formed by the oxidation of succinate by rat-liver and -heart mitochondria. BIOCHIMICA ET BIOPHYSICA ACTA 1969; 180:45-55. [PMID: 5787271 DOI: 10.1016/0005-2728(69)90192-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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