1
|
Affiliation(s)
- Peter Schönfeld
- Institut für Biochemie und Zellbiologie; Leipziger Str. 44 39120 Magdeburg
| | | |
Collapse
|
2
|
Schönfeld P, Reiser G. Brain energy metabolism spurns fatty acids as fuel due to their inherent mitotoxicity and potential capacity to unleash neurodegeneration. Neurochem Int 2017; 109:68-77. [PMID: 28366720 DOI: 10.1016/j.neuint.2017.03.018] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2017] [Revised: 03/20/2017] [Accepted: 03/24/2017] [Indexed: 12/21/2022]
Abstract
The brain uses long-chain fatty acids (LCFAs) to a negligible extent as fuel for the mitochondrial energy generation, in contrast to other tissues that also demand high energy. Besides this generally accepted view, some studies using cultured neural cells or whole brain indicate a moderately active mitochondrial β-oxidation. Here, we corroborate the conclusion that brain mitochondria are unable to oxidize fatty acids. In contrast, the combustion of liver-derived ketone bodies by neural cells is long-known. Furthermore, new insights indicate the use of odd-numbered medium-chain fatty acids as valuable source for maintaining the level of intermediates of the citric acid cycle in brain mitochondria. Non-esterified LCFAs or their activated forms exert a large variety of harmful side-effects on mitochondria, such as enhancing the mitochondrial ROS generation in distinct steps of the β-oxidation and therefore potentially increasing oxidative stress. Hence, the question arises: Why do in brain energy metabolism mitochondria selectively spurn LCFAs as energy source? The most likely answer are the relatively higher content of peroxidation-sensitive polyunsaturated fatty acids and the low antioxidative defense in brain tissue. There are two remarkable peroxisomal defects, one relating to α-oxidation of phytanic acid and the other to uptake of very long-chain fatty acids (VLCFAs) which lead to pathologically high tissue levels of such fatty acids. Both, the accumulation of phytanic acid and that of VLCFAs give an enlightening insight into harmful activities of fatty acids on neural cells, which possibly explain why evolution has prevented brain mitochondria from the equipment with significant β-oxidation enzymatic capacity.
Collapse
Affiliation(s)
- Peter Schönfeld
- Institut für Biochemie und Zellbiologie, Medizinische Fakultät, Otto-von-Guericke-Universität Magdeburg, Leipziger Straße 44, D-39120 Magdeburg, Germany
| | - Georg Reiser
- Institut für Inflammation und Neurodegeneration (Neurobiochemie), Medizinische Fakultät, Otto-von-Guericke-Universität Magdeburg, Leipziger Straße 44, D-39120 Magdeburg, Germany.
| |
Collapse
|
3
|
Artiukhov AV, Graf AV, Bunik VI. Directed regulation of multienzyme complexes of 2-oxo acid dehydrogenases using phosphonate and phosphinate analogs of 2-oxo acids. BIOCHEMISTRY (MOSCOW) 2016; 81:1498-1521. [DOI: 10.1134/s0006297916120129] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
|
4
|
Pan X, Zhu B, Zhu H, Chen Y, Tian H, Luo Y, Fu D. iTRAQ Protein Profile Analysis of Tomato Green-ripe Mutant Reveals New Aspects Critical for Fruit Ripening. J Proteome Res 2014; 13:1979-93. [DOI: 10.1021/pr401091n] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- Xiaoqi Pan
- The College of Food Science and Nutritional
Engineering, China Agricultural University, No. 17 Tsinghua East Road, Beijing 100083, PR China
| | - Benzhong Zhu
- The College of Food Science and Nutritional
Engineering, China Agricultural University, No. 17 Tsinghua East Road, Beijing 100083, PR China
| | - Hongliang Zhu
- The College of Food Science and Nutritional
Engineering, China Agricultural University, No. 17 Tsinghua East Road, Beijing 100083, PR China
| | - Yuexi Chen
- The College of Food Science and Nutritional
Engineering, China Agricultural University, No. 17 Tsinghua East Road, Beijing 100083, PR China
| | - Huiqin Tian
- The College of Food Science and Nutritional
Engineering, China Agricultural University, No. 17 Tsinghua East Road, Beijing 100083, PR China
| | - Yunbo Luo
- The College of Food Science and Nutritional
Engineering, China Agricultural University, No. 17 Tsinghua East Road, Beijing 100083, PR China
| | - Daqi Fu
- The College of Food Science and Nutritional
Engineering, China Agricultural University, No. 17 Tsinghua East Road, Beijing 100083, PR China
| |
Collapse
|
5
|
Lloyd MD, Yevglevskis M, Lee GL, Wood PJ, Threadgill MD, Woodman TJ. α-Methylacyl-CoA racemase (AMACR): Metabolic enzyme, drug metabolizer and cancer marker P504S. Prog Lipid Res 2013; 52:220-30. [DOI: 10.1016/j.plipres.2013.01.001] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2012] [Revised: 01/14/2013] [Accepted: 01/15/2013] [Indexed: 10/27/2022]
|
6
|
Hormetics: dietary triggers of an adaptive stress response. Pharm Res 2011; 28:2680-94. [PMID: 21818712 DOI: 10.1007/s11095-011-0551-1] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2011] [Accepted: 07/27/2011] [Indexed: 12/31/2022]
Abstract
A series of dietary ingredients and metabolites are able to induce an adaptive stress response either by generation of reactive oxygen species (ROS) and/or via activation of the Nrf2/Keap1 stress response network. Most of the molecules belong to activated Michael acceptors, electrophiles capable to S-alkylate redox sensitive cysteine thiols. This review summarizes recent advances in the (re)search of these compounds and classifies them into distinct groups. More than 60 molecules are described that induce the Nrf2 network, most of them found in our daily diet. Although known as typical antioxidants, a closer look reveals that these molecules induce an initial mitochondrial or cytosolic ROS formation and thereby trigger an adaptive stress response and hormesis, respectively. This, however, leads to higher levels of intracellular glutathione and increased expression levels of antioxidant enzymes such as glutathione peroxidase, thioredoxin reductase, and superoxide dismutase. According to this principle, the author suggests the term hormetics to describe these indirect antioxidants.
Collapse
|
7
|
Van Veldhoven PP. Biochemistry and genetics of inherited disorders of peroxisomal fatty acid metabolism. J Lipid Res 2010; 51:2863-95. [PMID: 20558530 DOI: 10.1194/jlr.r005959] [Citation(s) in RCA: 247] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
In humans, peroxisomes harbor a complex set of enzymes acting on various lipophilic carboxylic acids, organized in two basic pathways, alpha-oxidation and beta-oxidation; the latter pathway can also handle omega-oxidized compounds. Some oxidation products are crucial to human health (primary bile acids and polyunsaturated FAs), whereas other substrates have to be degraded in order to avoid neuropathology at a later age (very long-chain FAs and xenobiotic phytanic acid and pristanic acid). Whereas total absence of peroxisomes is lethal, single peroxisomal protein deficiencies can present with a mild or severe phenotype and are more informative to understand the pathogenic factors. The currently known single protein deficiencies equal about one-fourth of the number of proteins involved in peroxisomal FA metabolism. The biochemical properties of these proteins are highlighted, followed by an overview of the known diseases.
Collapse
Affiliation(s)
- Paul P Van Veldhoven
- Katholieke Universiteit Leuven, Department of Molecular Cell Biology, LIPIT, Campus Gasthuisberg, Herestraat, Leuven, Belgium.
| |
Collapse
|
8
|
Peroxisomes, lipid metabolism and lipotoxicity. Biochim Biophys Acta Mol Cell Biol Lipids 2010; 1801:272-80. [DOI: 10.1016/j.bbalip.2010.01.001] [Citation(s) in RCA: 122] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2009] [Revised: 01/07/2010] [Accepted: 01/07/2010] [Indexed: 12/26/2022]
|
9
|
Amaral AU, Leipnitz G, Fernandes CG, Seminotti B, Schuck PF, Wajner M. Alpha-ketoisocaproic acid and leucine provoke mitochondrial bioenergetic dysfunction in rat brain. Brain Res 2010; 1324:75-84. [PMID: 20153737 DOI: 10.1016/j.brainres.2010.02.018] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2009] [Revised: 01/30/2010] [Accepted: 02/04/2010] [Indexed: 11/27/2022]
Abstract
Patients affected by maple syrup urine disease (MSUD) present severe neurological symptoms and brain abnormalities, whose pathophysiology is poorly known. In the present study we investigated the in vitro effects of leucine (Leu), alpha-ketoisocaproic acid (KIC) and alpha-hydroxyisovaleric acid (HIV), respectively, the branched-chain amino, keto and hydroxy acids that most accumulate in MSUD, on brain bioenergetic homeostasis, evaluating respiratory parameters obtained by oxygen consumption, membrane potential (Psim), NAD(P)H content, swelling and citric acid cycle enzyme activities in mitochondrial preparations from rat forebrain using glutamate plus malate, succinate or alpha-ketoglutarate as respiratory substrates. KIC increased state 4 and decreased the respiratory control ratio with all substrates, in contrast with Leu and HIV. Furthermore, KIC and Leu, but not HIV, decreased state 3 using alpha-ketoglutarate. A KIC-induced selective inhibition of alpha-ketoglutarate dehydrogenase activity was also verified, with no alteration of the other citric acid cycle activities. The ADP/O ratio and the mitochondrial NAD(P)H levels were also reduced by KIC using glutamate/malate and alpha-ketoglutarate. In addition, KIC caused a reduction in the Psim when alpha-ketoglutarate was the substrate. Finally, KIC was not able to induce mitochondrial swelling. The present data indicate that KIC acts as an uncoupler of oxidative phosphorylation and as a metabolic inhibitor possibly through its inhibitory effect on alpha-ketoglutarate dehydrogenase activity, while Leu acts as a metabolic inhibitor. It is suggested that impairment of mitochondrial homeostasis caused by the major metabolites accumulating in MSUD may be involved in the neuropathology of this disease.
Collapse
Affiliation(s)
- Alexandre Umpierrez Amaral
- Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal de Rio Grande do Sul, Rua Ramiro Barcelos 2600, Porto Alegre-RS, Brazil
| | | | | | | | | | | |
Collapse
|
10
|
Graf A, Kabysheva M, Klimuk E, Trofimova L, Dunaeva T, Zündorf G, Kahlert S, Reiser G, Storozhevykh T, Pinelis V, Sokolova N, Bunik V. Role of 2-oxoglutarate dehydrogenase in brain pathologies involving glutamate neurotoxicity. ACTA ACUST UNITED AC 2009. [DOI: 10.1016/j.molcatb.2009.02.016] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
11
|
Bunik VI, Kabysheva MS, Klimuk EI, Storozhevykh TP, Pinelis VG. Phosphono Analogues of 2-Oxoglutarate Protect Cerebellar Granule Neurons upon Glutamate Excitotoxicity. Ann N Y Acad Sci 2009; 1171:521-9. [DOI: 10.1111/j.1749-6632.2009.04709.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
|
12
|
Wiczer BM, Bernlohr DA. A novel role for fatty acid transport protein 1 in the regulation of tricarboxylic acid cycle and mitochondrial function in 3T3-L1 adipocytes. J Lipid Res 2009; 50:2502-13. [PMID: 19535819 DOI: 10.1194/jlr.m900218-jlr200] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Fatty acid transport proteins (FATPs) are integral membrane acyl-CoA synthetases implicated in adipocyte fatty acid influx and esterification. Whereas some FATP1 translocates to the plasma membrane in response to insulin, the majority of FATP1 remains within intracellular structures and bioinformatic and immunofluorescence analysis of FATP1 suggests the protein primarily resides in the mitochondrion. To evaluate potential roles for FATP1 in mitochondrial metabolism, we used a proteomic approach following immunoprecipitation of endogenous FATP1 from 3T3-L1 adipocytes and identified mitochondrial 2-oxoglutarate dehydrogenase. To assess the functional consequence of the interaction, purified FATP1 was reconstituted into phospholipid-containing vesicles and its effect on 2-oxoglutarate dehydrogenase activity evaluated. FATP1 enhanced the activity of 2-oxoglutarate dehydrogenase independently of its acyl-CoA synthetase activity whereas silencing of FATP1 in 3T3-L1 adipocytes resulted in decreased activity of 2-oxoglutarate dehydrogenase. FATP1 silenced 3T3-L1 adipocytes exhibited decreased tricarboxylic acid cycle activity, increased cellular NAD(+)/NADH, increased fatty acid oxidation, and increased lactate production indicative of altered mitochondrial energy metabolism. These results reveal a novel role for FATP1 as a regulator of tricarboxylic acid cycle activity and mitochondrial function.
Collapse
Affiliation(s)
- Brian M Wiczer
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN, USA
| | | |
Collapse
|
13
|
Kabysheva MS, Storozhevykh TP, Pinelis VG, Bunik VI. Synthetic regulators of the 2-oxoglutarate oxidative decarboxylation alleviate the glutamate excitotoxicity in cerebellar granule neurons. Biochem Pharmacol 2009; 77:1531-40. [PMID: 19426691 DOI: 10.1016/j.bcp.2009.02.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2008] [Revised: 01/29/2009] [Accepted: 02/02/2009] [Indexed: 11/24/2022]
Abstract
Impairment of the 2-oxoglutarate oxidative decarboxylation by the 2-oxoglutarate dehydrogenase complex (OGDHC) is associated with the glutamate accumulation, ROS production and neuropathologies. We hypothesized that correct function of OGDHC under metabolic stress is essential to overcome the glutamate excitotoxic action on neurons. We show that synthetic phosphono analogs of 2-oxoglutarate, succinyl phosphonate and its phosphono ethyl ester, improve the catalysis by brain OGDHC through inhibiting the side reaction of irreversible inactivation of its first component, 2-oxoglutarate dehydrogenase. Under the substrate and cofactor saturation, the component and complex undergo the inactivation during catalysis with the apparent rate constant 0.2 min(-1). The inactivation rate is reduced by 90% and 60% in the presence of 50 microM succinyl phosphonate and its phosphono ethyl ester, correspondingly. In cultured cerebellar granule neurons exposed to excitotoxic glutamate, the phosphonates (100 microM) protect from the irreversible impairment of mitochondrial function and delayed calcium deregulation. The deregulation amplitude is decreased by succinyl phosphonate and its phosphono ethyl ester by 50% and 30%, correspondingly. Thus, succinyl phosphonate is more potent than its phosphono ethyl ester in protecting both the isolated brain OGDHC from inactivation and cultured neurons from the glutamate-induced calcium deregulation. The correlation of the relative efficiency of the phosphonates in vitro and in situ indicates that their cellular effects are due to targeting OGDHC, which is in accord with independent studies. We conclude that the compounds preserving the 2-oxoglutarate dehydrogenase activity are of neuroprotective value upon metabolic disbalance induced by glutamate excess.
Collapse
Affiliation(s)
- Maria S Kabysheva
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, 119992 Moscow, Russian Federation
| | | | | | | |
Collapse
|
14
|
Araújo WL, Nunes-Nesi A, Trenkamp S, Bunik VI, Fernie AR. Inhibition of 2-oxoglutarate dehydrogenase in potato tuber suggests the enzyme is limiting for respiration and confirms its importance in nitrogen assimilation,. PLANT PHYSIOLOGY 2008; 148:1782-96. [PMID: 18842826 PMCID: PMC2593666 DOI: 10.1104/pp.108.126219] [Citation(s) in RCA: 98] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2008] [Accepted: 10/01/2008] [Indexed: 05/19/2023]
Abstract
The 2-oxoglutarate dehydrogenase complex constitutes a mitochondrially localized tricarboxylic acid cycle multienzyme system responsible for the conversion of 2-oxoglutarate to succinyl-coenzyme A concomitant with NAD(+) reduction. Although regulatory mechanisms of plant enzyme complexes have been characterized in vitro, little is known concerning their role in plant metabolism in situ. This issue has recently been addressed at the cellular level in nonplant systems via the use of specific phosphonate inhibitors of the enzyme. Here, we describe the application of these inhibitors for the functional analysis of the potato (Solanum tuberosum) tuber 2-oxoglutarate dehydrogenase complex. In vitro experiments revealed that succinyl phosphonate (SP) and a carboxy ethyl ester of SP are slow-binding inhibitors of the 2-oxoglutarate dehydrogenase complex, displaying greater inhibitory effects than a diethyl ester of SP, a phosphono ethyl ester of SP, or a triethyl ester of SP. Incubation of potato tuber slices with the inhibitors revealed that they were adequately taken up by the tissue and produced the anticipated effects on the in situ enzyme activity. In order to assess the metabolic consequences of the 2-oxoglutarate dehydrogenase complex inhibition, we evaluated the levels of a broad range of primary metabolites using an established gas chromatography-mass spectrometry method. We additionally analyzed the rate of respiration in both tuber discs and isolated mitochondria. Finally, we evaluated the metabolic fate of radiolabeled acetate, 2-oxoglutarate or glucose, and (13)C-labeled pyruvate and glutamate following incubation of tuber discs in the presence or absence of either SP or the carboxy ethyl ester of SP. The data obtained are discussed in the context of the roles of the 2-oxoglutarate dehydrogenase complex in respiration and carbon-nitrogen interactions.
Collapse
Affiliation(s)
- Wagner L Araújo
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, 14476 Potsdam-Golm, Germany
| | | | | | | | | |
Collapse
|
15
|
Bunik V, Kaehne T, Degtyarev D, Shcherbakova T, Reiser G. Novel isoenzyme of 2-oxoglutarate dehydrogenase is identified in brain, but not in heart. FEBS J 2008; 275:4990-5006. [PMID: 18783430 DOI: 10.1111/j.1742-4658.2008.06632.x] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
2-Oxoglutarate dehydrogenase (OGDH) is the first and rate-limiting component of the multienzyme OGDH complex (OGDHC) whose malfunction is associated with neurodegeneration. The essential role of this complex in the degradation of glucose and glutamate, which have specific significance in brain, raises questions about the existence of brain-specific OGDHC isoenzyme(s). We purified OGDHC from extracts of brain or heart mitochondria using the same procedure of poly(ethylene glycol) fractionation, followed by size-exclusion chromatography. Chromatographic behavior and the insufficiency of mitochondrial disruption to solubilize OGDHC revealed functionally significant binding of the complex to membrane. Components of OGDHC from brain and heart were identified using nano-high performance liquid chromatography electrospray tandem mass spectrometry after trypsinolysis of the electrophoretically separated proteins. In contrast to the heart complex, where only the known OGDH was determined, the band corresponding to the brain OGDH component was found to also include the novel 2-oxoglutarate dehydrogenase-like (OGDHL) protein. The ratio of identified peptides characteristic of OGDH and OGDHL was preserved during purification and indicated comparable quantities of the two proteins in brain. Brain OGDHC also differed from the heart complex in the abundance of the components, lower apparent molecular mass and decreased stability upon size-exclusion chromatography. The functional competence of the novel brain isoenzyme and different regulation of OGDH and OGDHL by 2-oxoglutarate are inferred from the biphasic dependence of the overall reaction rate versus 2-oxoglutarate concentration. OGDHL may thus participate in brain-specific control of 2-oxoglutarate distribution between energy production and synthesis of the neurotransmitter glutamate.
Collapse
Affiliation(s)
- Victoria Bunik
- Bioengineering and Bioinformatics Department, Lomonosov Moscow State University, Russia.
| | | | | | | | | |
Collapse
|