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Segev S, Yitzhaky A, Ben Shachar D, Hertzberg L. VDAC genes down-regulation in brain samples of individuals with schizophrenia is revealed by a systematic meta-analysis. Neurosci Res 2023:S0168-0102(23)00022-6. [PMID: 36717018 DOI: 10.1016/j.neures.2023.01.012] [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: 11/05/2022] [Revised: 01/23/2023] [Accepted: 01/26/2023] [Indexed: 01/29/2023]
Abstract
Mitochondrial dysfunction was shown to be involved in schizophrenia pathophysiology. Abnormal energy states can lead to alterations in neural function and thereby to the cognitive and behavioral aberrations characteristics of schizophrenia. Voltage-dependent anion-selective channels (VDAC) are located in the outer mitochondrial membrane and are involved in mitochondrial energy production. Only few studies explored VDAC genes' expression in schizophrenia, and their results were not consistent. We conducted a systematic meta-analysis of ten brain samples gene expression datasets (overall 368 samples, 179 schizophrenia, 189 controls). In addition, we conducted a meta-analysis of three blood samples datasets (overall 300 samples, 167 schizophrenia, 133 controls). Pairwise correlation analysis was conducted between the VDAC and proteasome subunit genes' expression patterns. VDAC1, VDAC2 and VDAC3 showed significant down-regulation in brain samples of patients with schizophrenia. They also showed significant positive correlations with the proteasome subunit genes' expression levels. Our findings suggest that VDAC genes might play a role in mitochondrial dysfunction in schizophrenia. VDAC1 was down-regulated also in blood samples, which suggests its potential role as a biomarker for schizophrenia. The correlation with proteasome subunits, which were previously shown to be down-regulated in a subgroup of the patients, suggests that our findings might characterize a subgroup of the patients. This direction has the potential to lead to patients' stratification and more precisely-targeted therapy and necessitates further study.
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Affiliation(s)
- Shaked Segev
- Sackler School of Medicine, Tel-Aviv University, Israel
| | - Assif Yitzhaky
- Department of Physics of Complex Systems, Weizmann Institute of Science, Rehovot, Israel
| | - Dorit Ben Shachar
- Psychobiology Research Lab, Department of Neuroscience, The Ruth and Bruce Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Israel
| | - Libi Hertzberg
- Sackler School of Medicine, Tel-Aviv University, Israel; Shalvata Mental Health Center, Israel; Department of Physics of Complex Systems, Weizmann Institute of Science, Rehovot, Israel.
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Poleti MD, Moncau CT, Silva-Vignato B, Rosa AF, Lobo AR, Cataldi TR, Negrão JA, Silva SL, Eler JP, de Carvalho Balieiro JC. Label-free quantitative proteomic analysis reveals muscle contraction and metabolism proteins linked to ultimate pH in bovine skeletal muscle. Meat Sci 2018; 145:209-219. [DOI: 10.1016/j.meatsci.2018.06.041] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Revised: 06/28/2018] [Accepted: 06/28/2018] [Indexed: 12/23/2022]
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VDAC electronics: 5. Mechanism and computational model of hexokinase-dependent generation of the outer membrane potential in brain mitochondria. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2018; 1860:2599-2607. [PMID: 30291922 DOI: 10.1016/j.bbamem.2018.10.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Revised: 09/07/2018] [Accepted: 10/02/2018] [Indexed: 01/01/2023]
Abstract
Glycolysis plays a key role in brain energy metabolism. The initial and rate-limiting step of brain glycolysis is catalyzed mainly by hexokinase I (HKI), the majority of which is bound to the mitochondrial outer membrane (MOM), mostly through the mitochondrial inter-membrane contact sites formed by the voltage-dependent anion channel (VDAC, outer membrane) and the adenine nucleotide translocator (ANT, inner membrane). Earlier, we proposed a mechanism for the generation of the mitochondrial outer membrane potential (OMP) as a result of partial application of the inner membrane potential (IMP) to MOM through the electrogenic ANT-VDAC-HK inter-membrane contact sites. According to this previous mechanism, the Gibbs free energy of the hexokinase reaction might modulate the generated OMP (Lemeshko, Biophys. J., 2002). In the present work, a new computational model was developed to perform thermodynamic estimations of the proposed mechanism of IMP-HKI-mediated generation of OMP. The calculated OMP was high enough to electrically regulate MOM permeability for negatively charged metabolites through free, unbound VDACs in MOM. On the other hand, the positive-inside polarity of OMP generated by the IMP-HKI-mediated mechanism is expected to protect mitochondria against elevated concentrations of cytosolic Ca2+. This computational analysis suggests that metabolically-dependent generation of OMP in the brain mitochondria, controlled by many factors that modulate VDAC1-HKI interaction, VDAC's voltage-gating properties and permeability, might represent one of the physiological mechanisms of regulation of the brain energy metabolism and of neuronal death resistance, and might also be involved in various neurodegenerative disorders, such as Alzheimer's disease.
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Regulation of Calcium Homeostasis by ER Redox: A Close-Up of the ER/Mitochondria Connection. J Mol Biol 2017; 429:620-632. [PMID: 28137421 DOI: 10.1016/j.jmb.2017.01.017] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 01/20/2017] [Accepted: 01/20/2017] [Indexed: 01/17/2023]
Abstract
Calcium signaling plays an important role in cell survival by influencing mitochondria-related processes such as energy production and apoptosis. The endoplasmic reticulum (ER) is the main storage compartment for cell calcium (Ca2+; ~60-500μM), and the Ca2+ released by the ER has a prompt effect on the homeostasis of the juxtaposed mitochondria. Recent findings have highlighted a close connection between ER redox and Ca2+ signaling that is mediated by Ca2+-handling proteins. This paper describes the redox-regulated mediators and mechanisms that orchestrate Ca2+ signals from the ER to mitochondria.
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Crepaldi CR, Merighe GKF, Laure HJ, Rosa JC, Meirelles FV, César MDC. Isolamento e cultivo de neurônios e neuroesferas de córtex cerebral aviar. PESQUISA VETERINÁRIA BRASILEIRA 2013. [DOI: 10.1590/s0100-736x2013001300008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Métodos de cultivo celular são convenientes na realização de análises funcionais de alterações/interações protéicas das células neuronais, auxiliando a decifrar o interactoma de proteínas chaves na neurogênese de doenças do Sistema Nervoso Central. Por esse motivo, culturas de neurônios e neuroesferas isolados do córtex cerebral aviar representam um modelo acessível para o estudo de diversas doenças neurológicas, tal como a epilepsia. A espécie aviar apresenta peculiaridades em seu proteoma neuronal, visto a presença de uma expressão diferenciada de proteínas chaves no metabolismo energético cerebral, algumas destas (VDAC1 e VDAC2) desempenham papel importante na compreensão do mecanismo da epilepsia refratária. A metodologia estabelecida no presente estudo obteve cultivo de neuroeferas, onde as células cresceram tipicamente em aglomerados atingindo, dentro de 7 dias, o diâmetro ideal de 100-200 µm. A diferenciação celular das neuroesferas foi obtida após a aderência destas às placas tratadas com poli-D-lisina, evidenciada pela migração de fibras do interior da neuroesfera. Ao contrário das neuroesferas, os neurônios em cultivo extenderam seus neuritos após 11 dias de isolamento. Tal modelo in vitro pode ser utilizado com sucesso na identificação das variáveis neuroproteômicas, propiciando uma avaliação global das alterações dinâmicas e suas interações protéicas. Tal modelo pode ter aplicações em estudos dos efeitos de indutores da morte celular e bloqueadores de canais de membrana mitocondriais em proteínas chaves do metabolismo energético cerebral.
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Maurya SR, Mahalakshmi R. Modulation of human mitochondrial voltage-dependent anion channel 2 (hVDAC-2) structural stability by cysteine-assisted barrel-lipid interactions. J Biol Chem 2013; 288:25584-25592. [PMID: 23873934 DOI: 10.1074/jbc.m113.493692] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Human mitochondrial voltage-dependent anion channel 2 (hVDAC-2), the most predominant isoform seen in brain mitochondria, is not only crucial for cell survival but is also implicated in Alzheimer disease. The abundance of cysteines in this isoform is particularly fascinating, as hVDAC-1 cysteines have no associated functional role. We report a detailed biophysical examination of a Cys-less mutant of hVDAC-2, and its behavioral comparison with the wild type protein. Our findings suggest that cysteine mutation results in the formation of a better barrel at the expense of weakened protein-lipid interactions. The wild type protein displays stronger lipid association, despite being less structured. A reversal in behavior of both proteins is observed in the case of chemical denaturation, with the Cys-less mutant exhibiting lowered unfolding free energies. In bicellar systems comprising 14-C phosphocholines, we observe that protein-lipid interactions are weakened in both constructs, resulting in barrel structure destabilization. Our biochemical and biophysical studies together reveal key structural roles for the cysteine residues. We find that minor conformational variations in local residues are sufficient to define the membrane protein dynamics in hVDAC-2. Such subtle sequence variations contribute to differential stability of VDACs and may have implications in their in vivo regulation and recycling.
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Affiliation(s)
- Svetlana Rajkumar Maurya
- From the Molecular Biophysics Laboratory, Department of Biological Sciences, Indian Institute of Science Education and Research, Bhopal 462023, India
| | - Radhakrishnan Mahalakshmi
- From the Molecular Biophysics Laboratory, Department of Biological Sciences, Indian Institute of Science Education and Research, Bhopal 462023, India.
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Crepaldi CR, Vitale PAM, Tesch AC, Laure HJ, Rosa JC, de Cerqueira César M. Application of 2D BN/SDS-PAGE coupled with mass spectrometry for identification of VDAC-associated protein complexes related to mitochondrial binding sites for type I brain hexokinase. Mitochondrion 2013; 13:823-30. [PMID: 23719229 DOI: 10.1016/j.mito.2013.05.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2012] [Revised: 02/27/2013] [Accepted: 05/14/2013] [Indexed: 11/25/2022]
Abstract
Two types of binding sites for hexokinase, designated as Type A or Type B sites, have been shown to coexist on brain mitochondria. The ratio of these sites varies between species. HK1 attaches by reversibly binding to the voltage dependent anion channel (VDAC). Regarding the nature of hexokinase binding sites, we investigated if it was linked to distinct VDAC interactomes. We approached this question by 2D BN/SDS-PAGE of mitochondria, followed by mass spectrometry. Our results are consistent with the possibility that the ratio of Type A/Type B sites is due to differential VDAC interactions in bovine and rat neuronal cells.
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Affiliation(s)
- Carla Rossini Crepaldi
- Department of Basic Sciences, School of Animal Science and Food Engineering, University of São Paulo, Pirassununga, Brazil
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Vitale PAM, Crepaldi CR, Tesch AC, Albuquerque RD, César MDC. Purificação e caracterização da VDAC de mitocôndrias corticais aviares: identificação de modificações pós-traducionais nas porinas neuronais murinas e aviares. PESQUISA VETERINÁRIA BRASILEIRA 2012. [DOI: 10.1590/s0100-736x2012001200024] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
A VDAC é uma porina presente na MME cuja função é crucial no metabolismo energético, sobrevivência e morte celular. A caracterização da VDAC torna-se importante para a compreensão das inter-relações da mitocôndria com os diferentes componentes citosólicos, tais como a HK. A ligação HK-VDAC favorece a utilização do ATP intramitocondrial em células neuronais, a HK cerebral pode interagir de formas diferentes com a VDAC, o que resulta em diferentes sítios de ligação (sítios A e B). Os variados papéis metabólicos das isoformas da VDAC podem ser explicados pela presença de alterações pós-traducionais. No presente trabalho purificamos a VDAC1 mitocondrial neuronal proveniente de cérebro aviar. Paralelamente, comprovamos que a presença de múltiplas formas das VDACs 1 e 2 em cérebros murino e aviar, seja devida à presença de modificações pós-traducionais, nomeadamente a fosforilação. A proteína isolada apresentou peso molecular de 30KDa. Quando submetida à eletroforese e posteriormente à coloração para a identificação de fosfoproteínas, a mesma mostrou-se desfosforilada. O conhecimento da presença, ou ausência de fosforilação das VDACs, reside na importância de estabelecer-se as bases moleculares ligadas à existência de sítios A e B nas mitocôndrias neuronais.
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Crepaldi CR, Munin FS, Vitale PAM, César MDC. Análise interactômica da VDAC (voltage-dependent anion selective channel) nos cérebros aviar, bovino e murino. PESQUISA VETERINÁRIA BRASILEIRA 2011. [DOI: 10.1590/s0100-736x2011001100016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A VDAC é a proteína mais abundante na membrana mitocondrial externa. Exerce o controle da atividade desta organela através da regulação da troca de metabólitos e tem função crucial no mecanismo de apoptose. Em nosso caso, os estudos dos complexos protéicos, das interações entre a VDAC e outras proteínas presentes no interior do neurônio que auxiliam na manutenção das funções das organelas e da célula, fazem parte da chamada interactômica. O presente estudo determinou o interactoma do complexo protéico Hexoquinase-VDAC-ANT presente em cérebros murino, bovino e aviar. Nosso objetivo foi identificar se as expressões diferenciadas da VDAC1 e VDAC2 verificadas nos cérebros murino, aviar e bovino, estão associadas a diferenças nos interactomas dessas proteínas. Este estudo revelou que as espécies aviar e bovina apresentaram o maior número de complexos protéicos contendo VDACs (5) quando comparadas com os neurônios de rato (1), o que é indicativo de uma cinética diferencial de montagem ou desmontagem do complexo. Além disso, a VDAC mitocondrial neuronal aviar também interage com mais proteínas em relação à VDAC mitocondrial neuronal bovina, o que é resultado de uma composição de subunidades diferenciada. Tais resultados indicam diferenças significativas quanto ao metabolismo energético e apoptótico no cérebro aviar, bovino e murino, existindo interações diferenciais da VDAC no cérebro aviar.
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Ramsay EE, Hogg PJ, Dilda PJ. Mitochondrial metabolism inhibitors for cancer therapy. Pharm Res 2011; 28:2731-44. [PMID: 21918915 DOI: 10.1007/s11095-011-0584-5] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2011] [Accepted: 09/07/2011] [Indexed: 01/15/2023]
Abstract
Cancer cells catabolise nutrients in a different way than healthy cells. Healthy cells mainly rely on oxidative phosphorylation, while cancer cells employ aerobic glycolysis. Glucose is the main nutrient catabolised by healthy cells, while cancer cells often depend on catabolism of both glucose and glutamine. A key organelle involved in this altered metabolism is mitochondria. Mitochondria coordinate the catabolism of glucose and glutamine across the cancer cell. Targeting mitochondrial metabolism in cancer cells has potential for the treatment of this disease. Perhaps the most promising target is the hexokinase-voltage dependent anion channel-adenine nucleotide translocase complex that spans the outer- and inner-mitochondrial membranes. This complex links glycolysis, oxidative phosphorylation and mitochondrial-mediated apoptosis in cancer cells. This review discusses cancer cell mitochondrial metabolism and the small molecule inhibitors of this metabolism that are in pre-clinical or clinical development.
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Affiliation(s)
- Emma E Ramsay
- Prince of Wales Clinical School, Lowy Cancer Research Centre, University of New South Wales, Sydney, NSW 2052, Australia
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