TY - JOUR AU - Chinopoulos, Christos TI - Complex I activity in hypoxia: implications for oncometabolism JF - BIOCHEMICAL SOCIETY TRANSACTIONS J2 - BIOCHEM SOC T VL - 52 PY - 2024 PG - 10 SN - 0300-5127 DO - 10.1042/BST20230189 UR - https://m2.mtmt.hu/api/publication/34758725 ID - 34758725 AB - Certain cancer cells within solid tumors experience hypoxia, rendering them incapable of oxidative phosphorylation (OXPHOS). Despite this oxygen deficiency, these cells exhibit biochemical pathway activity that relies on NAD+. This mini-review scrutinizes the persistent, residual Complex I activity that oxidizes NADH in the absence of oxygen as the electron acceptor. The resulting NAD+ assumes a pivotal role in fueling the α-ketoglutarate dehydrogenase complex, a critical component in the oxidative decarboxylation branch of glutaminolysis — a hallmark oncometabolic pathway. The proposition is that through glutamine catabolism, high-energy phosphate intermediates are produced via substrate-level phosphorylation in the mitochondrial matrix substantiated by succinyl-CoA ligase, partially compensating for an OXPHOS deficiency. These insights provide a rationale for exploring Complex I inhibitors in cancer treatment, even when OXPHOS functionality is already compromised. LA - English DB - MTMT ER - TY - JOUR AU - Ravasz, Dóra AU - Bui, Dávid AU - Nazarian, Sara AU - Pallag, Gergely AU - Karnok, Noémi AU - Roberts, Jennie AU - Marzullo, Bryan P. AU - Tennant, Daniel A. AU - Greenwood, Bennett AU - Kitayev, Alex AU - Hill, Collin AU - Komlódi, Tímea AU - Doerrier, Carolina AU - Cunatova, Kristyna AU - Fernandez-Vizarra, Erika AU - Gnaiger, Erich AU - Kiebish, Michael A. AU - Raska, Alexandra AU - Kolev, Kraszimir Nikolaev AU - Czumbel, Bence AU - Narain, Niven R. AU - Seyfried, Thomas N. AU - Chinopoulos, Christos TI - Residual Complex I activity and amphidirectional Complex II operation support glutamate catabolism through mtSLP in anoxia JF - SCIENTIFIC REPORTS J2 - SCI REP VL - 14 PY - 2024 IS - 1 PG - 21 SN - 2045-2322 DO - 10.1038/s41598-024-51365-4 UR - https://m2.mtmt.hu/api/publication/34518788 ID - 34518788 N1 - Department of Biochemistry, Semmelweis University, Budapest, 1094, Hungary Institute of Metabolism and Systems Research, College of Medical and Dental Sciences, University of Birmingham, Birmingham, B15 2TT, United Kingdom BERG, Framingham, MA 01701, United States Oroboros Instruments, Innsbruck, Austria Department of Biomedical Sciences, University of Padova, Padova, 35131, Italy Biology Department, Boston College, Chestnut Hill, Boston, MA 02467, United States Export Date: 11 March 2024 Correspondence Address: Chinopoulos, C.; Department of Biochemistry, Hungary; email: chinopoulos.christos@semmelweis.hu AB - Anoxia halts oxidative phosphorylation (OXPHOS) causing an accumulation of reduced compounds in the mitochondrial matrix which impedes dehydrogenases. By simultaneously measuring oxygen concentration, NADH autofluorescence, mitochondrial membrane potential and ubiquinone reduction extent in isolated mitochondria in real-time, we demonstrate that Complex I utilized endogenous quinones to oxidize NADH under acute anoxia. 13 C metabolic tracing or untargeted analysis of metabolites extracted during anoxia in the presence or absence of site-specific inhibitors of the electron transfer system showed that NAD + regenerated by Complex I is reduced by the 2-oxoglutarate dehydrogenase Complex yielding succinyl-CoA supporting mitochondrial substrate-level phosphorylation (mtSLP), releasing succinate. Complex II operated amphidirectionally during the anoxic event, providing quinones to Complex I and reducing fumarate to succinate. Our results highlight the importance of quinone provision to Complex I oxidizing NADH maintaining glutamate catabolism and mtSLP in the absence of OXPHOS. LA - English DB - MTMT ER - TY - CHAP AU - Noakes, T.D. AU - Kalamian, M. AU - Seyfried, T.N. AU - Mukherjee, P. AU - D’Agostino, D.P. AU - Arismendi-Morillo, G. AU - Chinopoulos, Christos AU - Tettenborn, M. AU - Winters, N. TI - Cancer T2 - Ketogenic: The Science of Therapeutic Carbohydrate Restriction in Human Health PB - Elsevier SN - 9780128216231 T3 - Ketogenic: The Science of Therapeutic Carbohydr. Restriction in Hum. Health PY - 2023 SP - 307 EP - 362 PG - 56 DO - 10.1016/B978-0-12-821617-0.00012-7 UR - https://m2.mtmt.hu/api/publication/34093022 ID - 34093022 N1 - Export Date: 22 August 2023 AB - Since the discovery of DNA, the metabolic theory of cancer has been sidelined for genetic research. Yet cancer continues to rise. New research recaptures mitochondria as the driver, while upregulation of oncogenes and tumour suppressor mutations are recognised as downstream of the damage to oxidative phosphorylation (OxPhos). Despite the prevalence of the somatic (genetic) mutation theory, there are numerous inconsistencies. In contrast, it appears that all cancers are characterised by dysfunctional mitochondria. Cancer pre-1960 was a rare disease, all of which has changed as diets have. Press-pulse therapy and ketogenic diets (KD) have proven effective therapies, due to cancers’ selective metabolism of glucose and glutamine (Warburg effect), in combination with the non-fermentability of ketones. Some dietary aspects are individualised to the patient and cancer, but follow this general protocol. Fasting induces additional selective stress to cancers. With cancer genetic research stagnating and metabolic approaches showing promise, this perspective offers a new path forward. © 2023 Elsevier Inc. All rights reserved. LA - English DB - MTMT ER - TY - JOUR AU - Dóczi, Judit AU - Karnok, Noémi AU - Bui, Dávid AU - Azarov, Victoria AU - Pallag, Gergely AU - Nazarian, Sara AU - Czumbel, Bence AU - Seyfried, Thomas N. AU - Chinopoulos, Christos TI - Viability of HepG2 and MCF-7 cells is not correlated with mitochondrial bioenergetics JF - SCIENTIFIC REPORTS J2 - SCI REP VL - 13 PY - 2023 IS - 1 PG - 16 SN - 2045-2322 DO - 10.1038/s41598-023-37677-x UR - https://m2.mtmt.hu/api/publication/34062226 ID - 34062226 N1 - Institute of Biochemistry and Molecular Biology, Department of Biochemistry, Semmelweis University, Budapest, 1094, Hungary Biology Department, Boston College, Chestnut Hill, MA 02467, United States Export Date: 11 August 2023 Correspondence Address: Chinopoulos, C.; Institute of Biochemistry and Molecular Biology, Hungary; email: chinopoulos.christos@med.semmelweis-univ.hu Correspondence Address: Seyfried, T.N.; Biology Department, United States; email: thomas.seyfried@bc.edu Chemicals/CAS: reduced nicotinamide adenine dinucleotide dehydrogenase (ubiquinone), 9028-04-0; Electron Transport Complex I Funding details: Nemzeti Kutatási Fejlesztési és Innovációs Hivatal, NKFIH, K135027, KH129567, VEKOP-2.3.2-16-2016-00002 Funding text 1: This work was supported by grants from NKFIH (KH129567, and K135027) to C.C. We thank the Department of Physiology of Semmelweis University for providing access to the ImageXpress Micro Confocal High Content Imaging System (supported by VEKOP-2.3.2-16-2016-00002). AB - Alterations in metabolism are a hallmark of cancer. It is unclear if oxidative phosphorylation (OXPHOS) is necessary for tumour cell survival. In this study, we investigated the effects of severe hypoxia, site-specific inhibition of respiratory chain (RC) components, and uncouplers on necrotic and apoptotic markers in 2D-cultured HepG2 and MCF-7 tumour cells. Comparable respiratory complex activities were observed in both cell lines. However, HepG2 cells exhibited significantly higher oxygen consumption rates (OCR) and respiratory capacity than MCF-7 cells. Significant non-mitochondrial OCR was observed in MCF-7 cells, which was insensitive to acute combined inhibition of complexes I and III. Pre-treatment of either cell line with RC inhibitors for 24–72 h resulted in the complete abolition of respective complex activities and OCRs. This was accompanied by a time-dependent decrease in citrate synthase activity, suggesting mitophagy. High-content automated microscopy recordings revealed that the viability of HepG2 cells was mostly unaffected by any pharmacological treatment or severe hypoxia. In contrast, the viability of MCF-7 cells was strongly affected by inhibition of complex IV (CIV) or complex V (CV), severe hypoxia, and uncoupling. However, it was only moderately affected by inhibition of complexes I, II, and III. Cell death in MCF-7 cells induced by inhibition of complexes II, III, and IV was partially abrogated by aspartate. These findings indicate that OXPHOS activity and viability are not correlated in these cell lines, suggesting that the connection between OXPHOS and cancer cell survival is dependent on the specific cell type and conditions. LA - English DB - MTMT ER - TY - CONF AU - Dóra, Fanni AU - Tamara, Hajdu AU - Dobolyiné Renner, Éva AU - Palkovits, Miklós AU - Chinopoulos, Christos AU - Dobolyi, Árpád TI - Selective induction of Krebs cycle enzyme subunits in the parahippocampal cortex of suicide victims T2 - Joint Neuroscience Meeting of the Hungarian Neuroscience Society (MITT) & the Austrian Neuroscience Association (ANA) PY - 2023 UR - https://m2.mtmt.hu/api/publication/34010234 ID - 34010234 AB - Altered functional connectivity in human cortical networks has been reported in psychiatric disorders. One of these networks, the default mode network (DMN) is critical in mood disorders. Abnormal activity in the parahippocampal cortex (PHC), a moderating hub of the ventral DMN, has been reported in depressed patients and suicide attempters. Alterations in neuronal mitochondrial function may contribute to depression and suicidal behavior, however, little is known about the underlying molecular level changes in relevant structures including the PHC. Therefore, we addressed the protein level alterations of tricarboxylic acid cycle (Krebs cycle) enzyme subunits in the PHC of suicide victims by reverse phase protein array (RPPA). Postmortem human brain samples were collected from 13 control and 11 suicide individuals. The entorhinal cortex (EC), adjacent to the PHC, was selected to serve as a control brain region. RPPA analysis revealed that the protein levels of DLD, OGDH, SDHB, SUCLA2 and SUCLG2 were significantly induced in the PHC but not in the EC. Subsequently, qRT-PCR was used to examine if mRNA level changes are behind altered protein levels associated with suicide. The identified expressional changes suggest the selective upregulation of major Krebs cycle enzyme subunits belonging to glutaminolysis in the PHC suggesting the potentiation and a prominent role of this process in the pathophysiology of suicidal behavior. LA - English DB - MTMT ER - TY - JOUR AU - Seyfried, Thomas N. AU - Arismendi-Morillo, Gabriel AU - Zuccoli, Giulio AU - Lee, Derek C. AU - Duraj, Tomas AU - Elsakka, Ahmed M. AU - Maroon, Joseph C. AU - Mukherjee, Purna AU - Ta, Linh AU - Shelton, Laura AU - D'Agostino, Dominic AU - Kiebish, Michael AU - Chinopoulos, Christos TI - Metabolic management of microenvironment acidity in glioblastoma JF - FRONTIERS IN ONCOLOGY J2 - FRONT ONCOL VL - 12 PY - 2022 PG - 16 SN - 2234-943X DO - 10.3389/fonc.2022.968351 UR - https://m2.mtmt.hu/api/publication/33101302 ID - 33101302 N1 - Biology Department, Boston College, Chestnut HillMA, United States Instituto de Investigaciones Biológicas, Facultad de Medicina, Universidad del Zulia, Maracaibo, Venezuela The Program for the Study of Neurodevelopment in Rare Disorders (NDRD), University of Pittsburgh, Pittsburgh, PA, United States Faculty of Medicine, Institute for Applied Molecular Medicine (IMMA), CEU San Pablo University, Madrid, Spain Neuro Metabolism, Faculty of Medicine, Alexandria University, Alexandria, Egypt Department of Neurosurgery, University of Pittsburgh, Medical Center, Pittsburgh, PA, United States Matterworks, Somerville, MA, United States Department of Molecular Pharmacology and Physiology, University of South Florida, Tampa, FL, United States BERG LLC, Framingham, MA, United States Department of Medical Biochemistry, Semmelweis University, Budapest, Hungary Export Date: 2 January 2023 Correspondence Address: Seyfried, T.N.; Biology Department, Chestnut Hill, United States; email: Thomas.seyfried@bc.edu Chemicals/CAS: 3 hydroxybutyric acid, 300-85-6; acetoacetic acid, 541-50-4, 623-58-5; adenosine triphosphate, 15237-44-2, 56-65-5, 987-65-5; aspartate aminotransferase, 9000-97-9; bevacizumab, 216974-75-3, 1438851-35-4; cholesterol, 57-88-5; dexamethasone, 50-02-2; glucose, 50-99-7, 84778-64-3; glutamate dehydrogenase, 9001-46-1; glutamic acid, 11070-68-1, 138-15-8, 56-86-0, 6899-05-4; glutamine, 56-85-9, 6899-04-3; lactate dehydrogenase; lactate dehydrogenase A; lactic acid, 113-21-3, 50-21-5; nucleoside diphosphate kinase, 9026-51-1; oxoglutarate dehydrogenase, 9031-02-1; pyruvate carboxylase, 9014-19-1; pyruvate dehydrogenase, 9014-20-4; somatomedin C, 67763-96-6; succinic acid, 110-15-6; succinyl coenzyme A, 604-98-8; superoxide dismutase, 37294-21-6, 9016-01-7, 9054-89-1; temozolomide, 85622-93-1 AB - Glioblastoma (GBM), similar to most cancers, is dependent on fermentation metabolism for the synthesis of biomass and energy (ATP) regardless of the cellular or genetic heterogeneity seen within the tumor. The transition from respiration to fermentation arises from the documented defects in the number, the structure, and the function of mitochondria and mitochondrial-associated membranes in GBM tissue. Glucose and glutamine are the major fermentable fuels that drive GBM growth. The major waste products of GBM cell fermentation (lactic acid, glutamic acid, and succinic acid) will acidify the microenvironment and are largely responsible for drug resistance, enhanced invasion, immunosuppression, and metastasis. Besides surgical debulking, therapies used for GBM management (radiation, chemotherapy, and steroids) enhance microenvironment acidification and, although often providing a time-limited disease control, will thus favor tumor recurrence and complications. The simultaneous restriction of glucose and glutamine, while elevating non-fermentable, anti-inflammatory ketone bodies, can help restore the pH balance of the microenvironment while, at the same time, providing a non-toxic therapeutic strategy for killing most of the neoplastic cells. LA - English DB - MTMT ER - TY - JOUR AU - Horváth, Gergő AU - Sváb, Gergely AU - Komlódi, Tímea AU - Ravasz, Dóra AU - Kacsó, Gergely AU - Dóczi, Judit AU - Chinopoulos, Christos AU - Ambrus, Attila AU - Tretter, László TI - Reverse and Forward Electron Flow-Induced H2O2 Formation Is Decreased in α-Ketoglutarate Dehydrogenase (α-KGDH) Subunit (E2 or E3) Heterozygote Knock Out Animals JF - ANTIOXIDANTS J2 - ANTIOXIDANTS-BASEL VL - 11 PY - 2022 IS - 8 PG - 19 SN - 2076-3921 DO - 10.3390/antiox11081487 UR - https://m2.mtmt.hu/api/publication/33070137 ID - 33070137 N1 - Cited By :1 Export Date: 7 October 2022 Correspondence Address: Tretter, L.; Department of Biochemistry, Hungary; email: tretter.laszlo@med.semmelweis-univ.hu Funding details: Semmelweis Egyetem, STIA-OTKA-2021, TKP2021-EGA-25 Funding details: Nemzeti Kutatási, Fejlesztési és Innovaciós Alap, NKFIA, EFOP-3.6.3-VEKOP-16-2017-00009 Funding text 1: This research was funded by the Hungarian Brain Research Program 2 (2017-1.2.1-NKP-2017-00002 to Vera Adam-Vizi, Semmelweis University), STIA-OTKA-2021 grant (from the Semmelweis University, to A.A.), TKP2021-EGA-25 grant to A.A. and C.C., Project no. TKP2021-EGA-25 has been implemented with the support provided by the Ministry of Innovation and Technology of Hungary from the National Research, Development and Innovation Fund, financed under the TKP2021-EGA funding scheme. EFOP-3.6.3-VEKOP-16-2017-00009 support to G.S. AB - 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. LA - English DB - MTMT ER - TY - JOUR AU - Pallag, Gergely AU - Nazarian, Sara AU - Ravasz, Dóra AU - Bui, Dávid AU - Komlódi, Tímea AU - Carolina, Doerrier AU - Erich, Gnaiger AU - Thomas N., Seyfried AU - Chinopoulos, Christos TI - Proline Oxidation Supports Mitochondrial ATP Production When Complex I Is Inhibited JF - INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES J2 - INT J MOL SCI VL - 23 PY - 2022 IS - 9 PG - 21 SN - 1661-6596 DO - 10.3390/ijms23095111 UR - https://m2.mtmt.hu/api/publication/32813300 ID - 32813300 LA - English DB - MTMT ER - TY - JOUR AU - Seyfried, T.N. AU - Chinopoulos, Christos TI - Can the mitochondrial metabolic theory explain better the origin and management of cancer than can the somatic mutation theory? JF - METABOLITES J2 - METABOLITES VL - 11 PY - 2021 IS - 9 SN - 2218-1989 DO - 10.3390/metabo11090572 UR - https://m2.mtmt.hu/api/publication/32218179 ID - 32218179 N1 - Export Date: 23 September 2021 Correspondence Address: Seyfried, T.N.; Department of Biology, United States; email: Thomas.seyfried@bc.edu Funding details: Kenneth Rainin Foundation, KRF Funding details: CHILDREN with CANCER UK Funding text 1: Funding: This research was funded by the Foundation for Metabolic Cancer Therapies, CrossFit Inc., The Nelson and Claudia Peltz Family Foundation, Lewis Topper, The John and Kathy Garcia Foundation, Edward Miller, Joseph Maroon, the George Yu Foundation, Kenneth Rainin Foundation, Children with Cancer UK, the Robert L. Corkin Charitable Foundation, and the Boston College Research Expense Fund for their support. LA - English DB - MTMT ER - TY - JOUR AU - Chinopoulos, Christos TI - The mystery of extramitochondrial proteins lysine succinylation JF - INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES J2 - INT J MOL SCI VL - 22 PY - 2021 IS - 11 PG - 15 SN - 1661-6596 DO - 10.3390/ijms22116085 UR - https://m2.mtmt.hu/api/publication/32072787 ID - 32072787 N1 - Funding Agency and Grant Number: NKFIHNational Research, Development & Innovation Office (NRDIO) - Hungary [FIKP-61822-64888-EATV, VEKOP 2.3.3-15-2016-00012, 2017-2.3.4-TET-RU-2017-00003, KH129567, K135027] Funding text: This work was supported by grants from NKFIH (FIKP-61822-64888-EATV, VEKOP 2.3.3-15-2016-00012, 2017-2.3.4-TET-RU-2017-00003, KH129567, and K135027) to CC. Cited By :1 Export Date: 30 July 2021 Correspondence Address: Chinopoulos, C.; Department of Biochemistry and Molecular Biology, Hungary; email: chinopoulos.christos@eok.sote.hu Cited By :1 Export Date: 9 September 2021 Correspondence Address: Chinopoulos, C.; Department of Biochemistry and Molecular Biology, Hungary; email: chinopoulos.christos@eok.sote.hu Cited By :1 Export Date: 22 September 2021 Correspondence Address: Chinopoulos, C.; Department of Biochemistry and Molecular Biology, Hungary; email: chinopoulos.christos@eok.sote.hu Chemicals/CAS: lysine, 56-87-1, 6899-06-5, 70-54-2; oxoglutarate dehydrogenase, 9031-02-1; protein, 67254-75-5; succinate dehydrogenase, 9002-02-2, 9028-10-8; Ketoglutarate Dehydrogenase Complex; Lysine; Proteins; SIRT5 protein, human; Sirtuins; Succinate Dehydrogenase Funding details: Nemzeti Kutatási Fejlesztési és Innovációs Hivatal, NKFIH, 2017-2.3.4-TET-RU-2017-00003, FIKP-61822-64888-EATV, K135027, KH129567, VEKOP 2.3.3-15-2016-00012 Funding text 1: Funding: This work was supported by grants from NKFIH (FIKP-61822-64888-EATV, VEKOP 2.3.3-15-2016-00012, 2017-2.3.4-TET-RU-2017-00003, KH129567, and K135027) to CC. AB - Lysine succinylation is a post-translational modification which alters protein function in both physiological and pathological processes. Mindful that it requires succinyl-CoA, a metabolite formed within the mitochondrial matrix that cannot permeate the inner mitochondrial membrane, the question arises as to how there can be succinylation of proteins outside mitochondria. The present mini-review examines pathways participating in peroxisomal fatty acid oxidation that lead to succinyl-CoA production, potentially supporting succinylation of extramitochondrial proteins. Furthermore, the influence of the mitochondrial status on cytosolic NAD+ availability affecting the activity of cytosolic SIRT5 iso1 and iso4—in turn regulating cytosolic protein lysine succinylations—is presented. Finally, the discovery that glia in the adult human brain lack subunits of both alpha-ketoglutarate dehydrogenase complex and succinate-CoA ligase—thus being unable to produce succinyl-CoA in the matrix—and yet exhibit robust pancellular lysine succinylation, is highlighted. © 2021 by the author. Licensee MDPI, Basel, Switzerland. LA - English DB - MTMT ER -