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Indurkar A, Kudale P, Rjabovs V, Heinmaa I, Demir Ö, Kirejevs M, Rubenis K, Chaturbhuj G, Turks M, Locs J. Small organic molecules containing amorphous calcium phosphate: synthesis, characterization and transformation. Front Bioeng Biotechnol 2024; 11:1329752. [PMID: 38283170 PMCID: PMC10811600 DOI: 10.3389/fbioe.2023.1329752] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2023] [Accepted: 12/13/2023] [Indexed: 01/30/2024] Open
Abstract
As the primary solid phase, amorphous calcium phosphate (ACP) is a pivotal precursor in cellular biomineralization. The intrinsic interplay between ACP and Howard factor underscores the significance of understanding their association for advancing biomimetic ACP development. While organic compounds play established roles in biomineralization, this study presents the synthesis of ACP with naturally occurring organic compounds (ascorbate, glutamate, and itaconate) ubiquitously found in mitochondria and vital for bone remodeling and healing. The developed ACP with organic compounds was meticulously characterized using XRD, FTIR, and solid-state 13C and 31P NMR. The morphological analysis revealed the characteristic spherical morphology with particle size close to 20 nm of all synthesized ACP variants. Notably, the type of organic compound strongly influences true density, specific surface area, particle size, and transformation. The in vitro analysis was performed with MC3T3-E1 cells, indicating the highest cell viability with ACP_ASC (ascorbate), followed by ACP_ITA (itaconate). The lowest cell viability was observed with 10 %w/v of ACP_GLU (glutamate); however, 1 %w/v of ACP_GLU was cytocompatible. Further, the effect of small organic molecules on the transformation of ACP to low crystalline apatite (Ap) was examined in Milli-Q® water, PBS, and α-MEM.
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Affiliation(s)
- Abhishek Indurkar
- Rudolfs Cimdins Riga Biomaterials Innovations and Development Centre of RTU, Institute of General Chemical Engineering, Faculty of Materials Science and Applied Chemistry, Riga Technical University, Riga, Latvia
- Baltic Biomaterials Centre of Excellence, Headquarters at Riga Technical University, Riga, Latvia
| | - Pawan Kudale
- Department of Pharmaceutical Sciences and Technology, Institute of Chemical Technology, Mumbai, India
| | - Vitālijs Rjabovs
- Institute of Technology of Organic Chemistry, Faculty of Materials Science and Applied Chemistry, Riga Technical University, Riga, Latvia
| | - Ivo Heinmaa
- National Institute of Chemical Physics and Biophysics, Tallinn, Estonia
| | - Öznur Demir
- Rudolfs Cimdins Riga Biomaterials Innovations and Development Centre of RTU, Institute of General Chemical Engineering, Faculty of Materials Science and Applied Chemistry, Riga Technical University, Riga, Latvia
- Baltic Biomaterials Centre of Excellence, Headquarters at Riga Technical University, Riga, Latvia
| | - Matvejs Kirejevs
- Rudolfs Cimdins Riga Biomaterials Innovations and Development Centre of RTU, Institute of General Chemical Engineering, Faculty of Materials Science and Applied Chemistry, Riga Technical University, Riga, Latvia
| | - Kristaps Rubenis
- Rudolfs Cimdins Riga Biomaterials Innovations and Development Centre of RTU, Institute of General Chemical Engineering, Faculty of Materials Science and Applied Chemistry, Riga Technical University, Riga, Latvia
- Baltic Biomaterials Centre of Excellence, Headquarters at Riga Technical University, Riga, Latvia
| | - Ganesh Chaturbhuj
- Department of Pharmaceutical Sciences and Technology, Institute of Chemical Technology, Mumbai, India
| | - Māris Turks
- Institute of Technology of Organic Chemistry, Faculty of Materials Science and Applied Chemistry, Riga Technical University, Riga, Latvia
| | - Janis Locs
- Rudolfs Cimdins Riga Biomaterials Innovations and Development Centre of RTU, Institute of General Chemical Engineering, Faculty of Materials Science and Applied Chemistry, Riga Technical University, Riga, Latvia
- Baltic Biomaterials Centre of Excellence, Headquarters at Riga Technical University, Riga, Latvia
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Petersen CE, Sun J, Silva K, Kosmach A, Balaban RS, Murphy E. Increased mitochondrial free Ca 2+ during ischemia is suppressed, but not eliminated by, germline deletion of the mitochondrial Ca 2+ uniporter. Cell Rep 2023; 42:112735. [PMID: 37421627 PMCID: PMC10529381 DOI: 10.1016/j.celrep.2023.112735] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Revised: 04/20/2023] [Accepted: 06/18/2023] [Indexed: 07/10/2023] Open
Abstract
Mitochondrial Ca2+ overload is proposed to regulate cell death via opening of the mitochondrial permeability transition pore. It is hypothesized that inhibition of the mitochondrial Ca2+ uniporter (MCU) will prevent Ca2+ accumulation during ischemia/reperfusion and thereby reduce cell death. To address this, we evaluate mitochondrial Ca2+ in ex-vivo-perfused hearts from germline MCU-knockout (KO) and wild-type (WT) mice using transmural spectroscopy. Matrix Ca2+ levels are measured with a genetically encoded, red fluorescent Ca2+ indicator (R-GECO1) using an adeno-associated viral vector (AAV9) for delivery. Due to the pH sensitivity of R-GECO1 and the known fall in pH during ischemia, hearts are glycogen depleted to decrease the ischemic fall in pH. At 20 min of ischemia, there is significantly less mitochondrial Ca2+ in MCU-KO hearts compared with MCU-WT controls. However, an increase in mitochondrial Ca2+ is present in MCU-KO hearts, suggesting that mitochondrial Ca2+ overload during ischemia is not solely dependent on MCU.
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Affiliation(s)
- Courtney E Petersen
- Cardiovascular Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Junhui Sun
- Cardiovascular Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Kavisha Silva
- Cardiovascular Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Anna Kosmach
- Cardiovascular Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Robert S Balaban
- Systems Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Elizabeth Murphy
- Cardiovascular Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA.
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Domínguez-Zorita S, Romero-Carramiñana I, Santacatterina F, Esparza-Moltó PB, Simó C, Del-Arco A, Núñez de Arenas C, Saiz J, Barbas C, Cuezva JM. IF1 ablation prevents ATP synthase oligomerization, enhances mitochondrial ATP turnover and promotes an adenosine-mediated pro-inflammatory phenotype. Cell Death Dis 2023; 14:413. [PMID: 37433784 DOI: 10.1038/s41419-023-05957-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Revised: 06/07/2023] [Accepted: 07/05/2023] [Indexed: 07/13/2023]
Abstract
ATPase Inhibitory Factor 1 (IF1) regulates the activity of mitochondrial ATP synthase. The expression of IF1 in differentiated human and mouse cells is highly variable. In intestinal cells, the overexpression of IF1 protects against colon inflammation. Herein, we have developed a conditional IF1-knockout mouse model in intestinal epithelium to investigate the role of IF1 in mitochondrial function and tissue homeostasis. The results show that IF1-ablated mice have increased ATP synthase/hydrolase activities, leading to profound mitochondrial dysfunction and a pro-inflammatory phenotype that impairs the permeability of the intestinal barrier compromising mouse survival upon inflammation. Deletion of IF1 prevents the formation of oligomeric assemblies of ATP synthase and alters cristae structure and the electron transport chain. Moreover, lack of IF1 promotes an intramitochondrial Ca2+ overload in vivo, minimizing the threshold to Ca2+-induced permeability transition (mPT). Removal of IF1 in cell lines also prevents the formation of oligomeric assemblies of ATP synthase, minimizing the threshold to Ca2+-induced mPT. Metabolomic analyses of mice serum and colon tissue highlight that IF1 ablation promotes the activation of de novo purine and salvage pathways. Mechanistically, lack of IF1 in cell lines increases ATP synthase/hydrolase activities and installs futile ATP hydrolysis in mitochondria, resulting in the activation of purine metabolism and in the accumulation of adenosine, both in culture medium and in mice serum. Adenosine, through ADORA2B receptors, promotes an autoimmune phenotype in mice, stressing the role of the IF1/ATP synthase axis in tissue immune responses. Overall, the results highlight that IF1 is required for ATP synthase oligomerization and that it acts as a brake to prevent ATP hydrolysis under in vivo phosphorylating conditions in intestinal cells.
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Affiliation(s)
- Sonia Domínguez-Zorita
- Departamento de Biología Molecular, Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid (CSIC-UAM), 28049, Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER) ISCIII, Madrid, Spain
- Instituto de Investigación Hospital 12 de Octubre, Universidad Autónoma de Madrid, Madrid, Spain
| | - Inés Romero-Carramiñana
- Departamento de Biología Molecular, Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid (CSIC-UAM), 28049, Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER) ISCIII, Madrid, Spain
- Instituto de Investigación Hospital 12 de Octubre, Universidad Autónoma de Madrid, Madrid, Spain
| | - Fulvio Santacatterina
- Departamento de Biología Molecular, Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid (CSIC-UAM), 28049, Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER) ISCIII, Madrid, Spain
- Instituto de Investigación Hospital 12 de Octubre, Universidad Autónoma de Madrid, Madrid, Spain
| | - Pau B Esparza-Moltó
- Departamento de Biología Molecular, Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid (CSIC-UAM), 28049, Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER) ISCIII, Madrid, Spain
- Instituto de Investigación Hospital 12 de Octubre, Universidad Autónoma de Madrid, Madrid, Spain
| | - Carolina Simó
- Molecular Nutrition and Metabolism, Institute of Food Science Research (CIAL, CSIC-UAM), 28049, Madrid, Spain
| | - Araceli Del-Arco
- Departamento de Biología Molecular, Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid (CSIC-UAM), 28049, Madrid, Spain
- Facultad de Ciencias Ambientales y Bioquímica, Universidad de Castilla la Mancha, Toledo, 45071, Spain
- Centro Regional de Investigaciones Biomédicas, Unidad Asociada de Biomedicina, Toledo, 45071, Spain
| | - Cristina Núñez de Arenas
- Departamento de Biología Molecular, Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid (CSIC-UAM), 28049, Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER) ISCIII, Madrid, Spain
- Instituto de Investigación Hospital 12 de Octubre, Universidad Autónoma de Madrid, Madrid, Spain
| | - Jorge Saiz
- Centre of Metabolomics and Bioanalysis (CEMBIO), Department of Chemistry and Biochemistry, School of Pharmacy, Universidad San Pablo-CEU, CEU Universities, Urbanización Montepríncipe, 28660, Boadilla del Monte, Madrid, Spain
| | - Coral Barbas
- Centre of Metabolomics and Bioanalysis (CEMBIO), Department of Chemistry and Biochemistry, School of Pharmacy, Universidad San Pablo-CEU, CEU Universities, Urbanización Montepríncipe, 28660, Boadilla del Monte, Madrid, Spain
| | - José M Cuezva
- Departamento de Biología Molecular, Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid (CSIC-UAM), 28049, Madrid, Spain.
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER) ISCIII, Madrid, Spain.
- Instituto de Investigación Hospital 12 de Octubre, Universidad Autónoma de Madrid, Madrid, Spain.
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4
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Kharechkina ES, Nikiforova AB, Kruglov AG. Regulation of Mitochondrial Permeability Transition Pore Opening by Monovalent Cations in Liver Mitochondria. Int J Mol Sci 2023; 24:ijms24119237. [PMID: 37298189 DOI: 10.3390/ijms24119237] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 05/16/2023] [Accepted: 05/22/2023] [Indexed: 06/12/2023] Open
Abstract
The opening of the permeability transition pore (PTP) in mitochondria is a key event in the initiation of cell death in various pathologic states, including ischemia/reperfusion. The activation of K+ transport into mitochondria protects cells from ischemia/reperfusion. However, the role of K+ transport in PTP regulation is unclear. Here, we studied the role of K+ and other monovalent cations in the regulation of the PTP opening in an in vitro model. The registration of the PTP opening, membrane potential, Ca2+-retention capacity, matrix pH, and K+ transport was performed using standard spectral and electrode techniques. We found that the presence of all cations tested in the medium (K+, Na+, choline+, and Li+) strongly stimulated the PTP opening compared with sucrose. Several possible reasons for this were examined: the effect of ionic strength, the influx of cations through selective and non-selective channels and exchangers, the suppression of Ca2+/H+ exchange, and the influx of anions. The data obtained indicate that the mechanism of PTP stimulation by cations includes the suppression of K+/H+ exchange and acidification of the matrix, which facilitates the influx of phosphate. Thus, the K+/H+ exchanger and the phosphate carrier together with selective K+ channels compose a PTP regulatory triad, which might operate in vivo.
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Affiliation(s)
- Ekaterina S Kharechkina
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Institutskaya 3, Pushchino, 142290 Moscow, Russia
| | - Anna B Nikiforova
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Institutskaya 3, Pushchino, 142290 Moscow, Russia
| | - Alexey G Kruglov
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Institutskaya 3, Pushchino, 142290 Moscow, Russia
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Buswinka CJ, Nitta H, Osgood RT, Indzhykulian AA. SKOOTS: Skeleton oriented object segmentation for mitochondria. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.05.539611. [PMID: 37214838 PMCID: PMC10197543 DOI: 10.1101/2023.05.05.539611] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The segmentation of individual instances of mitochondria from imaging datasets is informative, yet time-consuming to do by hand, sparking interest in developing automated algorithms using deep neural networks. Existing solutions for various segmentation tasks are largely optimized for one of two types of biomedical imaging: high resolution three-dimensional (whole neuron segmentation in volumetric electron microscopy datasets) or two-dimensional low resolution (whole cell segmentation of light microscopy images). The former requires consistently predictable boundaries to segment large structures, while the latter is boundary invariant but struggles with segmentation of large 3D objects without downscaling. Mitochondria in whole cell 3D EM datasets often occupy the challenging middle ground: large with ambiguous borders, limiting accuracy with existing tools. To rectify this, we have developed skeleton oriented object segmentation (SKOOTS); a new segmentation approach which efficiently handles large, densely packed mitochondria. We show that SKOOTS can accurately, and efficiently, segment 3D mitochondria in previously difficult situations. Furthermore, we will release a new, manually annotated, 3D mitochondria segmentation dataset. Finally, we show this approach can be extended to segment objects in 3D light microscopy datasets. These results bridge the gap between existing segmentation approaches and increases the accessibility for three-dimensional biomedical image analysis.
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Affiliation(s)
- Christopher J Buswinka
- Eaton Peabody Laboratories, Mass Eye and Ear, Boston, MA, USA
- Department of Otolaryngology, Head and Neck Surgery, Harvard Medical School, Boston, MA, USA
- Speech and Hearing Biosciences and Technology graduate program, Harvard University, Cambridge, MA, USA
| | - Hidetomi Nitta
- Eaton Peabody Laboratories, Mass Eye and Ear, Boston, MA, USA
| | - Richard T Osgood
- Eaton Peabody Laboratories, Mass Eye and Ear, Boston, MA, USA
- Department of Otolaryngology, Head and Neck Surgery, Harvard Medical School, Boston, MA, USA
| | - Artur A Indzhykulian
- Eaton Peabody Laboratories, Mass Eye and Ear, Boston, MA, USA
- Department of Otolaryngology, Head and Neck Surgery, Harvard Medical School, Boston, MA, USA
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6
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Anitha A, Thanseem I, Iype M, Thomas SV. Mitochondrial dysfunction in cognitive neurodevelopmental disorders: Cause or effect? Mitochondrion 2023; 69:18-32. [PMID: 36621534 DOI: 10.1016/j.mito.2023.01.002] [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: 09/24/2022] [Revised: 12/21/2022] [Accepted: 01/04/2023] [Indexed: 01/07/2023]
Abstract
Mitochondria have a crucial role in brain development and neurogenesis, both in embryonic and adult brains. Since the brain is the highest energy consuming organ, it is highly vulnerable to mitochondrial dysfunction. This has been implicated in a range of brain disorders including, neurodevelopmental conditions, psychiatric illnesses, and neurodegenerative diseases. Genetic variations in mitochondrial DNA (mtDNA), and nuclear DNA encoding mitochondrial proteins, have been associated with several cognitive disorders. However, it is not yet clear whether mitochondrial dysfunction is a primary cause of these conditions or a secondary effect. Our review article deals with this topic, and brings out recent advances in mitochondria-oriented therapies. Mitochondrial dysfunction could be involved in the pathogenesis of a subset of disorders involving cognitive impairment. In these patients, mitochondrial dysfunction could be the cause of the condition, rather than the consequence. There are vast areas in this topic that remains to be explored and elucidated.
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Affiliation(s)
- Ayyappan Anitha
- Dept. of Neurogenetics, Institute for Communicative and Cognitive Neurosciences (ICCONS), Shoranur, Palakkad 679 523, Kerala, India.
| | - Ismail Thanseem
- Dept. of Neurogenetics, Institute for Communicative and Cognitive Neurosciences (ICCONS), Shoranur, Palakkad 679 523, Kerala, India
| | - Mary Iype
- Dept. of Pediatric Neurology, Government Medical College, Thiruvananthapuram 695 011, Kerala, India; Dept. of Neurology, ICCONS, Thiruvananthapuram 695 033, Kerala, India
| | - Sanjeev V Thomas
- Dept. of Neurology, ICCONS, Thiruvananthapuram 695 033, Kerala, India
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7
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Slobod D, Damia A, Leali M, Spinelli E, Mauri T. Pathophysiology and Clinical Meaning of Ventilation-Perfusion Mismatch in the Acute Respiratory Distress Syndrome. BIOLOGY 2022; 12:biology12010067. [PMID: 36671759 PMCID: PMC9855693 DOI: 10.3390/biology12010067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 12/20/2022] [Accepted: 12/27/2022] [Indexed: 01/03/2023]
Abstract
Acute respiratory distress syndrome (ARDS) remains an important clinical challenge with a mortality rate of 35-45%. It is being increasingly demonstrated that the improvement of outcomes requires a tailored, individualized approach to therapy, guided by a detailed understanding of each patient's pathophysiology. In patients with ARDS, disturbances in the physiological matching of alveolar ventilation (V) and pulmonary perfusion (Q) (V/Q mismatch) are a hallmark derangement. The perfusion of collapsed or consolidated lung units gives rise to intrapulmonary shunting and arterial hypoxemia, whereas the ventilation of non-perfused lung zones increases physiological dead-space, which potentially necessitates increased ventilation to avoid hypercapnia. Beyond its impact on gas exchange, V/Q mismatch is a predictor of adverse outcomes in patients with ARDS; more recently, its role in ventilation-induced lung injury and worsening lung edema has been described. Innovations in bedside imaging technologies such as electrical impedance tomography readily allow clinicians to determine the regional distributions of V and Q, as well as the adequacy of their matching, providing new insights into the phenotyping, prognostication, and clinical management of patients with ARDS. The purpose of this review is to discuss the pathophysiology, identification, consequences, and treatment of V/Q mismatch in the setting of ARDS, employing experimental data from clinical and preclinical studies as support.
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Affiliation(s)
- Douglas Slobod
- Department of Anesthesia, Critical Care and Emergency, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico Ca’ Granda, Ospedale Maggiore Policlinico, 20122 Milan, Italy
- Department of Critical Care Medicine, McGill University, Montreal, QC H3A 3R1, Canada
| | - Anna Damia
- Department of Pathophysiology and Transplantation, University of Milan, 20122 Milan, Italy
| | - Marco Leali
- Department of Pathophysiology and Transplantation, University of Milan, 20122 Milan, Italy
| | - Elena Spinelli
- Department of Anesthesia, Critical Care and Emergency, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico Ca’ Granda, Ospedale Maggiore Policlinico, 20122 Milan, Italy
| | - Tommaso Mauri
- Department of Anesthesia, Critical Care and Emergency, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico Ca’ Granda, Ospedale Maggiore Policlinico, 20122 Milan, Italy
- Department of Pathophysiology and Transplantation, University of Milan, 20122 Milan, Italy
- Correspondence:
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8
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Walkon LL, Strubbe-Rivera JO, Bazil JN. Calcium Overload and Mitochondrial Metabolism. Biomolecules 2022; 12:biom12121891. [PMID: 36551319 PMCID: PMC9775684 DOI: 10.3390/biom12121891] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 11/30/2022] [Accepted: 12/13/2022] [Indexed: 12/23/2022] Open
Abstract
Mitochondria calcium is a double-edged sword. While low levels of calcium are essential to maintain optimal rates of ATP production, extreme levels of calcium overcoming the mitochondrial calcium retention capacity leads to loss of mitochondrial function. In moderate amounts, however, ATP synthesis rates are inhibited in a calcium-titratable manner. While the consequences of extreme calcium overload are well-known, the effects on mitochondrial function in the moderately loaded range remain enigmatic. These observations are associated with changes in the mitochondria ultrastructure and cristae network. The present mini review/perspective follows up on previous studies using well-established cryo-electron microscopy and poses an explanation for the observable depressed ATP synthesis rates in mitochondria during calcium-overloaded states. The results presented herein suggest that the inhibition of oxidative phosphorylation is not caused by a direct decoupling of energy metabolism via the opening of a calcium-sensitive, proteinaceous pore but rather a separate but related calcium-dependent phenomenon. Such inhibition during calcium-overloaded states points towards mitochondrial ultrastructural modifications, enzyme activity changes, or an interplay between both events.
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Affiliation(s)
- Lauren L. Walkon
- Department of Physiology, Michigan State University, East Lansing, MI 48824, USA
| | - Jasiel O. Strubbe-Rivera
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI 48824, USA
- Correspondence:
| | - Jason N. Bazil
- Department of Physiology, Michigan State University, East Lansing, MI 48824, USA
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Proline Oxidation Supports Mitochondrial ATP Production When Complex I Is Inhibited. Int J Mol Sci 2022; 23:ijms23095111. [PMID: 35563503 PMCID: PMC9106064 DOI: 10.3390/ijms23095111] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Revised: 05/02/2022] [Accepted: 05/02/2022] [Indexed: 02/01/2023] Open
Abstract
The oxidation of proline to pyrroline-5-carboxylate (P5C) leads to the transfer of electrons to ubiquinone in mitochondria that express proline dehydrogenase (ProDH). This electron transfer supports Complexes CIII and CIV, thus generating the protonmotive force. Further catabolism of P5C forms glutamate, which fuels the citric acid cycle that yields the reducing equivalents that sustain oxidative phosphorylation. However, P5C and glutamate catabolism depend on CI activity due to NAD+ requirements. NextGen-O2k (Oroboros Instruments) was used to measure proline oxidation in isolated mitochondria of various mouse tissues. Simultaneous measurements of oxygen consumption, membrane potential, NADH, and the ubiquinone redox state were correlated to ProDH activity and F1FO-ATPase directionality. Proline catabolism generated a sufficiently high membrane potential that was able to maintain the F1FO-ATPase operation in the forward mode. This was observed in CI-inhibited mouse liver and kidney mitochondria that exhibited high levels of proline oxidation and ProDH activity. This action was not observed under anoxia or when either CIII or CIV were inhibited. The duroquinone fueling of CIII and CIV partially reproduced the effects of proline. Excess glutamate, however, could not reproduce the proline effect, suggesting that processes upstream of the glutamate conversion from proline were involved. The ProDH inhibitors tetrahydro-2-furoic acid and, to a lesser extent, S-5-oxo-2-tetrahydrofurancarboxylic acid abolished all proline effects. The data show that ProDH-directed proline catabolism could generate sufficient CIII and CIV proton pumping, thus supporting ATP production by the F1FO-ATPase even under CI inhibition.
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10
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Datta S, Jaiswal M. Mitochondrial calcium at the synapse. Mitochondrion 2021; 59:135-153. [PMID: 33895346 DOI: 10.1016/j.mito.2021.04.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 03/28/2021] [Accepted: 04/13/2021] [Indexed: 12/15/2022]
Abstract
Mitochondria are dynamic organelles, which serve various purposes, including but not limited to the production of ATP and various metabolites, buffering ions, acting as a signaling hub, etc. In recent years, mitochondria are being seen as the central regulators of cellular growth, development, and death. Since neurons are highly specialized cells with a heavy metabolic demand, it is not surprising that neurons are one of the most mitochondria-rich cells in an animal. At synapses, mitochondrial function and dynamics is tightly regulated by synaptic calcium. Calcium influx during synaptic activity causes increased mitochondrial calcium influx leading to an increased ATP production as well as buffering of synaptic calcium. While increased ATP production is required during synaptic transmission, calcium buffering by mitochondria is crucial to prevent faulty neurotransmission and excitotoxicity. Interestingly, mitochondrial calcium also regulates the mobility of mitochondria within synapses causing mitochondria to halt at the synapse during synaptic transmission. In this review, we summarize the various roles of mitochondrial calcium at the synapse.
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Affiliation(s)
- Sayantan Datta
- Tata Institute of Fundamental Research, Hyderabad, India
| | - Manish Jaiswal
- Tata Institute of Fundamental Research, Hyderabad, India.
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11
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Carinci M, Vezzani B, Patergnani S, Ludewig P, Lessmann K, Magnus T, Casetta I, Pugliatti M, Pinton P, Giorgi C. Different Roles of Mitochondria in Cell Death and Inflammation: Focusing on Mitochondrial Quality Control in Ischemic Stroke and Reperfusion. Biomedicines 2021; 9:biomedicines9020169. [PMID: 33572080 PMCID: PMC7914955 DOI: 10.3390/biomedicines9020169] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 02/03/2021] [Accepted: 02/04/2021] [Indexed: 12/12/2022] Open
Abstract
Mitochondrial dysfunctions are among the main hallmarks of several brain diseases, including ischemic stroke. An insufficient supply of oxygen and glucose in brain cells, primarily neurons, triggers a cascade of events in which mitochondria are the leading characters. Mitochondrial calcium overload, reactive oxygen species (ROS) overproduction, mitochondrial permeability transition pore (mPTP) opening, and damage-associated molecular pattern (DAMP) release place mitochondria in the center of an intricate series of chance interactions. Depending on the degree to which mitochondria are affected, they promote different pathways, ranging from inflammatory response pathways to cell death pathways. In this review, we will explore the principal mitochondrial molecular mechanisms compromised during ischemic and reperfusion injury, and we will delineate potential neuroprotective strategies targeting mitochondrial dysfunction and mitochondrial homeostasis.
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Affiliation(s)
- Marianna Carinci
- Laboratory for Technologies of Advanced Therapies, Department of Medical Sciences, University of Ferrara, 44121 Ferrara, Italy; (M.C.); (B.V.); (S.P.); (P.P.)
| | - Bianca Vezzani
- Laboratory for Technologies of Advanced Therapies, Department of Medical Sciences, University of Ferrara, 44121 Ferrara, Italy; (M.C.); (B.V.); (S.P.); (P.P.)
| | - Simone Patergnani
- Laboratory for Technologies of Advanced Therapies, Department of Medical Sciences, University of Ferrara, 44121 Ferrara, Italy; (M.C.); (B.V.); (S.P.); (P.P.)
| | - Peter Ludewig
- Department of Neurology, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20251 Hamburg, Germany; (P.L.); (K.L.); (T.M.)
| | - Katrin Lessmann
- Department of Neurology, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20251 Hamburg, Germany; (P.L.); (K.L.); (T.M.)
| | - Tim Magnus
- Department of Neurology, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20251 Hamburg, Germany; (P.L.); (K.L.); (T.M.)
| | - Ilaria Casetta
- Department of Neuroscience and Rehabilitation, University of Ferrara, 44121 Ferrara, Italy; (I.C.); (M.P.)
| | - Maura Pugliatti
- Department of Neuroscience and Rehabilitation, University of Ferrara, 44121 Ferrara, Italy; (I.C.); (M.P.)
| | - Paolo Pinton
- Laboratory for Technologies of Advanced Therapies, Department of Medical Sciences, University of Ferrara, 44121 Ferrara, Italy; (M.C.); (B.V.); (S.P.); (P.P.)
| | - Carlotta Giorgi
- Laboratory for Technologies of Advanced Therapies, Department of Medical Sciences, University of Ferrara, 44121 Ferrara, Italy; (M.C.); (B.V.); (S.P.); (P.P.)
- Correspondence:
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12
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Li A, Yi J, Li X, Zhou J. Physiological Ca 2+ Transients Versus Pathological Steady-State Ca 2+ Elevation, Who Flips the ROS Coin in Skeletal Muscle Mitochondria. Front Physiol 2020; 11:595800. [PMID: 33192612 PMCID: PMC7642813 DOI: 10.3389/fphys.2020.595800] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Accepted: 10/05/2020] [Indexed: 12/20/2022] Open
Abstract
Mitochondria are both the primary provider of ATP and the pivotal regulator of cell death, which are essential for physiological muscle activities. Ca2+ plays a multifaceted role in mitochondrial function. During muscle contraction, Ca2+ influx into mitochondria activates multiple enzymes related to tricarboxylic acid (TCA) cycle and oxidative phosphorylation, resulting in increased ATP synthesis to meet the energy demand. Pathophysiological conditions such as skeletal muscle denervation or unloading also lead to elevated Ca2+ levels inside mitochondria. However, the outcomes of this steady-state elevation of mitochondrial Ca2+ level include exacerbated reactive oxygen species (ROS) generation, sensitized opening of mitochondrial permeability transition pore (mPTP), induction of programmed cell death, and ultimately muscle atrophy. Previously, both acute and long-term endurance exercises have been reported to activate certain signaling pathways to counteract ROS production. Meanwhile, electrical stimulation is known to help prevent apoptosis and alleviate muscle atrophy in denervated animal models and patients with motor impairment. There are various mechanistic studies that focus on the excitation-transcription coupling framework to understand the beneficial role of exercise and electrical stimulation. Interestingly, a recent study has revealed an unexpected role of rapid mitochondrial Ca2+ transients in keeping mPTP at a closed state with reduced mitochondrial ROS production. This discovery motivated us to contribute this review article to inspire further discussion about the potential mechanisms underlying differential outcomes of physiological mitochondrial Ca2+ transients and pathological mitochondrial Ca2+ elevation in skeletal muscle ROS production.
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Affiliation(s)
- Ang Li
- Department of Kinesiology, College of Nursing and Health Innovation, The University of Texas at Arlington, Arlington, TX, United States
| | - Jianxun Yi
- Department of Kinesiology, College of Nursing and Health Innovation, The University of Texas at Arlington, Arlington, TX, United States
| | - Xuejun Li
- Department of Kinesiology, College of Nursing and Health Innovation, The University of Texas at Arlington, Arlington, TX, United States
| | - Jingsong Zhou
- Department of Kinesiology, College of Nursing and Health Innovation, The University of Texas at Arlington, Arlington, TX, United States
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13
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Vezzani B, Carinci M, Patergnani S, Pasquin MP, Guarino A, Aziz N, Pinton P, Simonato M, Giorgi C. The Dichotomous Role of Inflammation in the CNS: A Mitochondrial Point of View. Biomolecules 2020; 10:E1437. [PMID: 33066071 PMCID: PMC7600410 DOI: 10.3390/biom10101437] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 10/07/2020] [Accepted: 10/10/2020] [Indexed: 12/14/2022] Open
Abstract
Innate immune response is one of our primary defenses against pathogens infection, although, if dysregulated, it represents the leading cause of chronic tissue inflammation. This dualism is even more present in the central nervous system, where neuroinflammation is both important for the activation of reparatory mechanisms and, at the same time, leads to the release of detrimental factors that induce neurons loss. Key players in modulating the neuroinflammatory response are mitochondria. Indeed, they are responsible for a variety of cell mechanisms that control tissue homeostasis, such as autophagy, apoptosis, energy production, and also inflammation. Accordingly, it is widely recognized that mitochondria exert a pivotal role in the development of neurodegenerative diseases, such as multiple sclerosis, Parkinson's and Alzheimer's diseases, as well as in acute brain damage, such in ischemic stroke and epileptic seizures. In this review, we will describe the role of mitochondria molecular signaling in regulating neuroinflammation in central nervous system (CNS) diseases, by focusing on pattern recognition receptors (PRRs) signaling, reactive oxygen species (ROS) production, and mitophagy, giving a hint on the possible therapeutic approaches targeting mitochondrial pathways involved in inflammation.
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Affiliation(s)
- Bianca Vezzani
- Department of Medical Sciences, University of Ferrara, 44121 Ferrara, Italy; (B.V.); (M.C.); (S.P.); (M.P.P.); (P.P.)
- Laboratory of Technologies for Advanced Therapy (LTTA), Technopole of Ferrara, 44121 Ferrara, Italy; (A.G.); (N.A.); (M.S.)
| | - Marianna Carinci
- Department of Medical Sciences, University of Ferrara, 44121 Ferrara, Italy; (B.V.); (M.C.); (S.P.); (M.P.P.); (P.P.)
- Laboratory of Technologies for Advanced Therapy (LTTA), Technopole of Ferrara, 44121 Ferrara, Italy; (A.G.); (N.A.); (M.S.)
| | - Simone Patergnani
- Department of Medical Sciences, University of Ferrara, 44121 Ferrara, Italy; (B.V.); (M.C.); (S.P.); (M.P.P.); (P.P.)
- Laboratory of Technologies for Advanced Therapy (LTTA), Technopole of Ferrara, 44121 Ferrara, Italy; (A.G.); (N.A.); (M.S.)
| | - Matteo P. Pasquin
- Department of Medical Sciences, University of Ferrara, 44121 Ferrara, Italy; (B.V.); (M.C.); (S.P.); (M.P.P.); (P.P.)
- Laboratory of Technologies for Advanced Therapy (LTTA), Technopole of Ferrara, 44121 Ferrara, Italy; (A.G.); (N.A.); (M.S.)
| | - Annunziata Guarino
- Laboratory of Technologies for Advanced Therapy (LTTA), Technopole of Ferrara, 44121 Ferrara, Italy; (A.G.); (N.A.); (M.S.)
- Department of BioMedical and Specialist Surgical Sciences, University of Ferrara, 44121 Ferrara, Italy
| | - Nimra Aziz
- Laboratory of Technologies for Advanced Therapy (LTTA), Technopole of Ferrara, 44121 Ferrara, Italy; (A.G.); (N.A.); (M.S.)
- Department of BioMedical and Specialist Surgical Sciences, University of Ferrara, 44121 Ferrara, Italy
| | - Paolo Pinton
- Department of Medical Sciences, University of Ferrara, 44121 Ferrara, Italy; (B.V.); (M.C.); (S.P.); (M.P.P.); (P.P.)
- Laboratory of Technologies for Advanced Therapy (LTTA), Technopole of Ferrara, 44121 Ferrara, Italy; (A.G.); (N.A.); (M.S.)
- Maria Cecilia Hospital, GVM Care & Research, 48033 Cotignola (RA), Italy
| | - Michele Simonato
- Laboratory of Technologies for Advanced Therapy (LTTA), Technopole of Ferrara, 44121 Ferrara, Italy; (A.G.); (N.A.); (M.S.)
- Department of BioMedical and Specialist Surgical Sciences, University of Ferrara, 44121 Ferrara, Italy
- School of Medicine, University Vita-Salute San Raffaele, 20132 Milan, Italy
| | - Carlotta Giorgi
- Department of Medical Sciences, University of Ferrara, 44121 Ferrara, Italy; (B.V.); (M.C.); (S.P.); (M.P.P.); (P.P.)
- Laboratory of Technologies for Advanced Therapy (LTTA), Technopole of Ferrara, 44121 Ferrara, Italy; (A.G.); (N.A.); (M.S.)
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14
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Chinopoulos C. Ant1 mutant mice bridge the mitochondrial and serotonergic dysfunctions in bipolar disorder. Mol Psychiatry 2020; 25:2203-2204. [PMID: 30214044 DOI: 10.1038/s41380-018-0251-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Revised: 07/25/2018] [Accepted: 08/15/2018] [Indexed: 11/09/2022]
Affiliation(s)
- Christos Chinopoulos
- Department of Medical Biochemistry, Semmelweis University, Budapest, Tuzolto st. 37-47, 1094, Hungary.
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15
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Weiss AKH, Albertini E, Holzknecht M, Cappuccio E, Dorigatti I, Krahbichler A, Damisch E, Gstach H, Jansen-Dürr P. Regulation of cellular senescence by eukaryotic members of the FAH superfamily - A role in calcium homeostasis? Mech Ageing Dev 2020; 190:111284. [PMID: 32574647 PMCID: PMC7116474 DOI: 10.1016/j.mad.2020.111284] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 05/29/2020] [Accepted: 06/04/2020] [Indexed: 01/04/2023]
Abstract
Fumarylacetoacetate hydrolase (FAH) superfamily members are commonly expressed in the prokaryotic kingdom, where they take part in the committing steps of degradation pathways of complex carbon sources. Besides FAH itself, the only described FAH superfamily members in the eukaryotic kingdom are fumarylacetoacetate hydrolase domain containing proteins (FAHD) 1 and 2, that have been a focus of recent work in aging research. Here, we provide a review of current knowledge on FAHD proteins. Of those, FAHD1 has recently been described as a regulator of mitochondrial function and senescence, in the context of mitochondrial dysfunction associated senescence (MiDAS). This work further describes data based on bioinformatics analysis, 3D structure comparison and sequence alignment, that suggests a putative role of FAHD proteins as calcium binding proteins.
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Affiliation(s)
- Alexander K H Weiss
- University of Innsbruck, Research Institute for Biomedical Aging Research, Rennweg 10, A-6020, Innsbruck, Austria; University of Innsbruck, Center for Molecular Biosciences Innsbruck (CMBI), Austria.
| | - Eva Albertini
- University of Innsbruck, Research Institute for Biomedical Aging Research, Rennweg 10, A-6020, Innsbruck, Austria; University of Innsbruck, Center for Molecular Biosciences Innsbruck (CMBI), Austria
| | - Max Holzknecht
- University of Innsbruck, Research Institute for Biomedical Aging Research, Rennweg 10, A-6020, Innsbruck, Austria; University of Innsbruck, Center for Molecular Biosciences Innsbruck (CMBI), Austria
| | - Elia Cappuccio
- University of Innsbruck, Research Institute for Biomedical Aging Research, Rennweg 10, A-6020, Innsbruck, Austria; University of Innsbruck, Center for Molecular Biosciences Innsbruck (CMBI), Austria
| | - Ilaria Dorigatti
- University of Innsbruck, Research Institute for Biomedical Aging Research, Rennweg 10, A-6020, Innsbruck, Austria; University of Innsbruck, Center for Molecular Biosciences Innsbruck (CMBI), Austria
| | - Anna Krahbichler
- University of Innsbruck, Research Institute for Biomedical Aging Research, Rennweg 10, A-6020, Innsbruck, Austria; University of Innsbruck, Center for Molecular Biosciences Innsbruck (CMBI), Austria
| | - Elisabeth Damisch
- University of Innsbruck, Research Institute for Biomedical Aging Research, Rennweg 10, A-6020, Innsbruck, Austria; University of Innsbruck, Center for Molecular Biosciences Innsbruck (CMBI), Austria
| | - Hubert Gstach
- University of Vienna, UZ2 E349, Department of Pharmaceutical Chemistry, Faculty of Life Sciences, Althanstrasse 14, 1090, Vienna, Austria
| | - Pidder Jansen-Dürr
- University of Innsbruck, Research Institute for Biomedical Aging Research, Rennweg 10, A-6020, Innsbruck, Austria; University of Innsbruck, Center for Molecular Biosciences Innsbruck (CMBI), Austria
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16
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He Z, Ning N, Zhou Q, Khoshnam SE, Farzaneh M. Mitochondria as a therapeutic target for ischemic stroke. Free Radic Biol Med 2020; 146:45-58. [PMID: 31704373 DOI: 10.1016/j.freeradbiomed.2019.11.005] [Citation(s) in RCA: 125] [Impact Index Per Article: 31.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Revised: 10/07/2019] [Accepted: 11/03/2019] [Indexed: 12/24/2022]
Abstract
Stroke is the leading cause of death and physical disability worldwide. Mitochondrial dysfunction has been considered as one of the hallmarks of ischemic stroke and contributes to the pathology of ischemia and reperfusion. Mitochondria is essential in promoting neural survival and neurological improvement following ischemic stroke. Therefore, mitochondria represent an important drug target for stroke treatment. This review discusses the mitochondrial molecular mechanisms underlying cerebral ischemia and involved in reactive oxygen species generation, mitochondrial electron transport dysfunction, mitochondria-mediated regulation of inflammasome activation, mitochondrial dynamics and biogenesis, and apoptotic cell death. We highlight the potential of mitochondrial transfer by stem cells as a therapeutic target for stroke treatment and provide valuable insights for clinical strategies. A better understanding of the roles of mitochondria in ischemia-induced cell death and protection may provide a rationale design of novel therapeutic interventions in the ischemic stroke.
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Affiliation(s)
- Zhi He
- Department of Pharmacy, Luohe Medical College, Luohe, 462000, China
| | - Niya Ning
- Department of Obstetrics and Gynecology, Shaoling District People's Hospital of Luohe City, Luohe, 462300, China
| | - Qiongxiu Zhou
- Institute of Blood Transfusion, Chinese Academy of Medical Sciences, Chengdu, 610052, China.
| | - Seyed Esmaeil Khoshnam
- Physiology Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
| | - Maryam Farzaneh
- Department of Stem Cells and Developmental Biology, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, ACECR, Tehran, Iran
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17
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Bui D, Ravasz D, Chinopoulos C. The Effect of 2-Ketobutyrate on Mitochondrial Substrate-Level Phosphorylation. Neurochem Res 2019; 44:2301-2306. [PMID: 30810978 PMCID: PMC6776489 DOI: 10.1007/s11064-019-02759-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Revised: 02/19/2019] [Accepted: 02/20/2019] [Indexed: 01/31/2023]
Abstract
The reaction catalyzed by succinate-CoA ligase in the mitochondrial matrix yields a high-energy phosphate when operating towards hydrolysis of the thioester bond of succinyl-CoA, known as mitochondrial substrate-level phosphorylation (mSLP). The catabolism of several metabolites converge to succinyl-CoA but through different biochemical pathways. Among them, threonine, serine and methionine catabolize to succinyl-CoA through the common intermediate, 2-ketobutyrate. During the course of this pathway 2-ketobutyrate will become succinyl-CoA through propionyl-CoA catabolism, obligatorily passing through an ATP-consuming step substantiated by propionyl-CoA carboxylase. Here, by recording the directionality of the adenine nucleotide translocase while measuring membrane potential we tested the hypothesis that catabolism of 2-ketobutyrate negates mSLP due to the ATP-consuming propionyl-CoA carboxylase step in rotenone-treated, isolated mouse liver and brain mitochondria. 2-Ketobutyrate produced a less negative membrane potential compared to NADH or FADH2-linked substrates, which was sensitive to inhibition by rotenone, atpenin and arsenate, implying the involvement of complex I, complex II and a dehydrogenase-most likely branched chain keto-acid dehydrogenase, respectively. Co-addition of 2-ketobutyrate with NADH- or FADH2-linked substrates yielded no greater membrane potential than in the presence of substrates alone. However, in the presence of NADH-linked substrates, 2-ketobutyrate prevented mSLP in a dose-dependent manner. Our results imply that despite that 2-ketobutyrate leads to succinyl-CoA formation, obligatory metabolism through propionyl-CoA carboxylase associated with ATP expenditure abolishes mSLP. The provision of metabolites converging to 2-ketobutyrate may be a useful way for manipulating mSLP without using pharmacological or genetic tools.
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Affiliation(s)
- David Bui
- Department of Medical Biochemistry, Semmelweis University, Tuzolto st. 37-47, Budapest, 1094, Hungary
| | - Dora Ravasz
- Department of Medical Biochemistry, Semmelweis University, Tuzolto st. 37-47, Budapest, 1094, Hungary
| | - Christos Chinopoulos
- Department of Medical Biochemistry, Semmelweis University, Tuzolto st. 37-47, Budapest, 1094, Hungary.
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18
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Cyclosporin A Increases Mitochondrial Buffering of Calcium: An Additional Mechanism in Delaying Mitochondrial Permeability Transition Pore Opening. Cells 2019; 8:cells8091052. [PMID: 31500337 PMCID: PMC6770067 DOI: 10.3390/cells8091052] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2019] [Revised: 08/26/2019] [Accepted: 09/03/2019] [Indexed: 02/07/2023] Open
Abstract
Regulation of mitochondrial free Ca2+ is critically important for cellular homeostasis. An increase in mitochondrial matrix free Ca2+ concentration ([Ca2+]m) predisposes mitochondria to opening of the permeability transition pore (mPTP). Opening of the pore can be delayed by cyclosporin A (CsA), possibly by inhibiting cyclophilin D (Cyp D), a key regulator of mPTP. Here, we report on a novel mechanism by which CsA delays mPTP opening by enhanced sequestration of matrix free Ca2+. Cardiac-isolated mitochondria were challenged with repetitive CaCl2 boluses under Na+-free buffer conditions with and without CsA. CsA significantly delayed mPTP opening primarily by promoting matrix Ca2+ sequestration, leading to sustained basal [Ca2+]m levels for an extended period. The preservation of basal [Ca2+]m during the CaCl2 pulse challenge was associated with normalized NADH, matrix pH (pHm), and mitochondrial membrane potential (ΔΨm). Notably, we found that in PO43− (Pi)-free buffer condition, the CsA-mediated buffering of [Ca2+]m was abrogated, and mitochondrial bioenergetics variables were concurrently compromised. In the presence of CsA, addition of Pi just before pore opening in the Pi-depleted condition reinstated the Ca2+ buffering system and rescued mitochondria from mPTP opening. This study shows that CsA promotes Pi-dependent mitochondrial Ca2+ sequestration to delay mPTP opening and, concomitantly, maintains mitochondrial function.
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19
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Kiefmann M, Tank S, Tritt MO, Keller P, Heckel K, Schulte-Uentrop L, Olotu C, Schrepfer S, Goetz AE, Kiefmann R. Dead space ventilation promotes alveolar hypocapnia reducing surfactant secretion by altering mitochondrial function. Thorax 2019; 74:219-228. [PMID: 30636196 DOI: 10.1136/thoraxjnl-2018-211864] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 08/29/2018] [Accepted: 09/10/2018] [Indexed: 11/03/2022]
Abstract
BACKGROUND In acute respiratory distress syndrome (ARDS), pulmonary perfusion failure increases physiologic dead space ventilation (VD/VT), leading to a decline of the alveolar CO2 concentration [CO2]iA. Although it has been shown that alveolar hypocapnia contributes to formation of atelectasis and surfactant depletion, a typical complication in ARDS, the underlying mechanism has not been elucidated so far. METHODS In isolated perfused rat lungs, cytosolic or mitochondrial Ca2+ concentrations ([Ca2+]cyt or [Ca2+]mito, respectively) of alveolar epithelial cells (AECs), surfactant secretion and the projected area of alveoli were quantified by real-time fluorescence or bright-field imaging (n=3-7 per group). In ventilated White New Zealand rabbits, the left pulmonary artery was ligated and the size of subpleural alveoli was measured by intravital microscopy (n=4 per group). Surfactant secretion was determined in the bronchoalveolar lavage (BAL) by western blot. RESULTS Low [CO2]iA decreased [Ca2+]cyt and increased [Ca2+]mito in AECs, leading to reduction of Ca2+-dependent surfactant secretion, and alveolar ventilation in situ. Mitochondrial inhibition by ruthenium red or rotenone blocked these responses indicating that mitochondria are key players in CO2 sensing. Furthermore, ligature of the pulmonary artery of rabbits decreased alveolar ventilation, surfactant secretion and lung compliance in vivo. Addition of 5% CO2 to the inspiratory gas inhibited these responses. CONCLUSIONS Accordingly, we provide evidence that alveolar hypocapnia leads to a Ca2+ shift from the cytosol into mitochondria. The subsequent decline of [Ca2+]cyt reduces surfactant secretion and thus regional ventilation in lung regions with high VD/VT. Additionally, the regional hypoventilation provoked by perfusion failure can be inhibited by inspiratory CO2 application.
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Affiliation(s)
- Martina Kiefmann
- Department of Anesthesiology, University Hospital Hamburg-Eppendorf, Hamburg, Germany
| | - Sascha Tank
- Department of Anesthesiology, University Hospital Hamburg-Eppendorf, Hamburg, Germany
| | - Marc-Oliver Tritt
- Department of Anesthesiology, University Hospital Hamburg-Eppendorf, Hamburg, Germany
| | - Paula Keller
- Department of Anesthesiology, University Hospital Hamburg-Eppendorf, Hamburg, Germany
| | - Kai Heckel
- Department of Anesthesiology, University Hospital Hamburg-Eppendorf, Hamburg, Germany
| | | | - Cynthia Olotu
- Department of Anesthesiology, University Hospital Hamburg-Eppendorf, Hamburg, Germany
| | - Sonja Schrepfer
- Division of Adult Cardiothoracic Surgery, University of California San Francisco, San Francisco, California, USA.,Department of Cardiac Surgery, University Hospital Hamburg-Eppendorf, Hamburg, Germany
| | - Alwin E Goetz
- Department of Anesthesiology, University Hospital Hamburg-Eppendorf, Hamburg, Germany
| | - Rainer Kiefmann
- Department of Anesthesiology, University Hospital Hamburg-Eppendorf, Hamburg, Germany
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20
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Malyala S, Zhang Y, Strubbe JO, Bazil JN. Calcium phosphate precipitation inhibits mitochondrial energy metabolism. PLoS Comput Biol 2019; 15:e1006719. [PMID: 30615608 PMCID: PMC6336351 DOI: 10.1371/journal.pcbi.1006719] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2018] [Revised: 01/17/2019] [Accepted: 12/17/2018] [Indexed: 11/19/2022] Open
Abstract
Early studies have shown that moderate levels of calcium overload can cause lower oxidative phosphorylation rates. However, the mechanistic interpretations of these findings were inadequate. And while the effect of excessive calcium overload on mitochondrial function is well appreciated, there has been little to no reports on the consequences of low to moderate calcium overload. To resolve this inadequacy, mitochondrial function from guinea pig hearts was quantified using several well-established methods including high-resolution respirometry and spectrofluorimetry and analyzed using mathematical modeling. We measured key mitochondrial variables such as respiration, mitochondrial membrane potential, buffer calcium, and substrate effects for a range of mitochondrial calcium loads from near zero to levels approaching mitochondrial permeability transition. In addition, we developed a computer model closely mimicking the experimental conditions and used this model to design experiments capable of eliminating many hypotheses generated from the data analysis. We subsequently performed those experiments and determined why mitochondrial ADP-stimulated respiration is significantly lowered during calcium overload. We found that when calcium phosphate levels, not matrix free calcium, reached sufficient levels, complex I activity is inhibited, and the rate of ATP synthesis is reduced. Our findings suggest that calcium phosphate granules form physical barriers that isolate complex I from NADH, disrupt complex I activity, or destabilize cristae and inhibit NADH-dependent respiration. Mitochondrial calcium handling has been studied for nearly half a century. As we understand it today, low concentrations (1–10 nmol/mg mitochondria) of calcium exert beneficial effects on energy transduction. And high concentrations (>500 nmol/mg mitochondria) lead to respiratory uncoupling and membrane damage. But relatively little is known about the effect of moderate calcium concentrations (10–500 nmol/mg mitochondria) on mitochondrial function. At these concentrations, mitochondrial membrane integrity remains intact and energized, while ATP synthesis becomes significantly impaired. Prior studies have postulated several possible mechanisms, but the precise consequence of calcium overload on mitochondrial ATP production remained obscure. In this study, we combine experimental and computational approaches to show that calcium phosphate precipitation, as opposed to matrix free calcium, inhibits respiratory function at complex I just enough to limit proton pumping during oxidative phosphorylation and decrease ATP synthesis rates.
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Affiliation(s)
- Sathyavani Malyala
- Department of Physiology, Michigan State University, East Lansing, MI, United States of America
| | - Yizhu Zhang
- Department of Physiology, Michigan State University, East Lansing, MI, United States of America
| | - Jasiel O. Strubbe
- Department of Physiology, Michigan State University, East Lansing, MI, United States of America
| | - Jason N. Bazil
- Department of Physiology, Michigan State University, East Lansing, MI, United States of America
- * E-mail:
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21
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Dolowy K. Calcium phosphate buffer formed in the mitochondrial matrix during preconditioning supports ΔpH formation and ischemic ATP production and prolongs cell survival -A hypothesis. Mitochondrion 2018; 47:210-217. [PMID: 30448366 DOI: 10.1016/j.mito.2018.11.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Revised: 05/06/2018] [Accepted: 11/14/2018] [Indexed: 10/27/2022]
Abstract
Ischemic preconditioning makes cells less sensitive to oxygen deprivation. A similar effect can be achieved by increasing the calcium concentration and applying potassium channel openers. A hypothetical mechanism of preconditioning is presented. In the mitochondrial matrix, there is a calcium hydroxide buffer consisting of a few insoluble calcium phosphate minerals. During ischemia, calcium ions stored in the matrix buffer start to leak out, forming an electric potential difference, while hydroxyl ions remain in the matrix, maintaining its pH and the matrix volume. Preconditioning factors increase the matrix buffer capacity. Production of ATP during ischemia might be the relic of a pre-endosymbiotic past.
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Affiliation(s)
- Krzysztof Dolowy
- Department of Biophysics, Warsaw University of Life Sciences - SGGW, Nowoursynowska 159, Warszawa 02-776, Poland.
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22
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Vdac1 Downregulation Causes Mitochondrial Disintegration Leading to Hippocampal Neurodegeneration in Scopolamine-Induced Amnesic Mice. Mol Neurobiol 2018; 56:1707-1718. [PMID: 29916145 DOI: 10.1007/s12035-018-1164-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Accepted: 05/30/2018] [Indexed: 01/16/2023]
Abstract
Our previous report on hippocampal proteome analysis suggested the involvement of voltage-dependent anion channel (Vdac) 1 in scopolamine-induced amnesia. Further silencing of Vdac1 in young mice reduced the recognition memory. Vdac1 is a porin protein present abundantly on outer mitochondrial membrane. It acts as a transporter of energy metabolites ATP/ADP and Ca2+ ions and helps in communication between mitochondrial matrix and cytosol. As Vdac1-associated energy metabolism may be affected during amnesia, we determined the downstream function of Vdac1 in the present study. The expression of Vdac1 and total ATP level was decreased in the hippocampus of scopolamine-induced amnesic mice. Also, the mitochondrial membrane potential, cristae organization, and morphology were disrupted leading to increased ROS generation and reduced SOD and catalase activity. On the other hand, there was increase in the expression of pro-apoptotic marker proteins (Bax, Bad, Casp 3), leading to rising degenerated neuronal cells in the dentate gyrus and Cornu ammonis 3 and 1 subregions of the hippocampus during amnesia. Further, to check whether Vdac1 downregulation is associated with neurodegeneration, we infused Vdac1 siRNA stereotaxically in the hippocampus of normal young mice. As compared to control, Vdac1 silencing decreased ATP level and mitochondrial membrane potential leading to increase in the number of degenerated neuronal cells in subregions of the hippocampus. Taken together, our study shows that downregulation of Vdac1 causes neurodegeneration through mitochondrial disintegration in the hippocampus of scopolamine-induced amnesic mice.
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Function, regulation and physiological role of the mitochondrial Na + /Ca 2+ exchanger, NCLX. CURRENT OPINION IN PHYSIOLOGY 2018. [DOI: 10.1016/j.cophys.2018.02.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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Ravasz D, Kacso G, Fodor V, Horvath K, Adam-Vizi V, Chinopoulos C. Reduction of 2-methoxy-1,4-naphtoquinone by mitochondrially-localized Nqo1 yielding NAD + supports substrate-level phosphorylation during respiratory inhibition. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2018; 1859:909-924. [PMID: 29746824 DOI: 10.1016/j.bbabio.2018.05.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Revised: 04/26/2018] [Accepted: 05/03/2018] [Indexed: 01/07/2023]
Abstract
Provision of NAD+ for oxidative decarboxylation of alpha-ketoglutarate to succinyl-CoA by the ketoglutarate dehydrogenase complex (KGDHC) is critical for maintained operation of succinyl-CoA ligase yielding high-energy phosphates, a process known as mitochondrial substrate-level phosphorylation (mSLP). We have shown previously that when NADH oxidation by complex I is inhibited by rotenone or anoxia, mitochondrial diaphorases yield NAD+, provided that suitable quinones are present (Kiss G et al., FASEB J 2014, 28:1682). This allows for KGDHC reaction to proceed and as an extension of this, mSLP. NAD(P)H quinone oxidoreductase 1 (NQO1) is an enzyme exhibiting diaphorase activity. Here, by using Nqo1-/- and WT littermate mice we show that in rotenone-treated, isolated liver mitochondria 2-methoxy-1,4-naphtoquinone (MNQ) is preferentially reduced by matrix Nqo1 yielding NAD+ to KGDHC, supporting mSLP. This process was sensitive to inhibition by specific diaphorase inhibitors. Reduction of idebenone and its analogues MRQ-20 and MRQ-56, menadione, mitoquinone and duroquinone were unaffected by genetic disruption of the Nqo1 gene. The results allow for the conclusions that i) MNQ is a Nqo1-preferred substrate, and ii) in the presence of suitable quinones, mitochondrially-localized diaphorases other than Nqo1 support NADH oxidation when complex I is inhibited. Our work confirms that complex I bypass can occur by quinones reduced by intramitochondrial diaphorases oxidizing NADH, ultimately supporting mSLP. Finally, it may help to elucidate structure-activity relationships of redox-active quinones with diaphorase enzymes.
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Affiliation(s)
- Dora Ravasz
- Department of Medical Biochemistry, Semmelweis University, Budapest 1094, Hungary
| | - Gergely Kacso
- Department of Medical Biochemistry, Semmelweis University, Budapest 1094, Hungary
| | - Viktoria Fodor
- Department of Medical Biochemistry, Semmelweis University, Budapest 1094, Hungary
| | - Kata Horvath
- Department of Medical Biochemistry, Semmelweis University, Budapest 1094, Hungary
| | - Vera Adam-Vizi
- Department of Medical Biochemistry, Semmelweis University, Budapest 1094, Hungary
| | - Christos Chinopoulos
- Department of Medical Biochemistry, Semmelweis University, Budapest 1094, Hungary.
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IDH3 mediates apoptosis of alveolar epithelial cells type 2 due to mitochondrial Ca 2+ uptake during hypocapnia. Cell Death Dis 2017; 8:e3005. [PMID: 28837149 PMCID: PMC5596584 DOI: 10.1038/cddis.2017.403] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Revised: 07/14/2017] [Accepted: 07/16/2017] [Indexed: 01/25/2023]
Abstract
In adult respiratory distress syndrome (ARDS) pulmonary perfusion failure increases physiologic dead-space (VD/VT) correlating with mortality. High VD/VT results in alveolar hypocapnia, which has been demonstrated to cause edema formation, atelectasis, and surfactant depletion, evoked, at least in part, by apoptosis of alveolar epithelial cells (AEC). However, the mechanism underlying the hypocapnia-induced AEC apoptosis is unknown. Here, using fluorescent live-cell imaging of cultured AEC type 2 we could show that in terms of CO2 sensing the tricarboxylic acid cycle enzyme isocitrate dehydrogenase (IDH) 3 seems to be an important player because hypocapnia resulted independently from pH in an elevation of IDH3 activity and subsequently in an increase of NADH, the substrate of the respiratory chain. As a consequence, the mitochondrial transmembrane potential (ΔΨ) rose causing a Ca2+ shift from cytosol into mitochondria, whereas the IDH3 knockdown inhibited these responses. Furthermore, the hypocapnia-induced mitochondrial Ca2+ uptake resulted in reactive oxygen species (ROS) production, and both the mitochondrial Ca2+ uptake and ROS production induced apoptosis. Accordingly, we provide evidence that in AEC type 2 hypocapnia induces elevation of IDH3 activity leading to apoptosis. This finding might give new insight into the pathogenesis of ARDS and may help to develop novel strategies to reduce tissue injury in ARDS.
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Zhang R, Ma XN, Liu K, Zhang L, Yao M. Exogenous spermine preserves mitochondrial bioenergetics via regulating Src kinase signaling in the spinal cord. Mol Med Rep 2017; 16:3619-3626. [PMID: 28765886 DOI: 10.3892/mmr.2017.7030] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2017] [Accepted: 07/10/2017] [Indexed: 11/06/2022] Open
Abstract
Regulation of mitochondrial metabolism is becoming an important target in inhibiting necrosis and apoptosis following secondary spinal cord injury, and physiological compounds that reduce mitochondrial dysfunction are regarded as efficient protective reagents following injury. It has been demonstrated that spermine, a polyamine composed of four primary amines, may be taken up by a mitochondria‑specific uniporter and may preserve mitochondrial bioenergetics, suggesting that it may be important in the pathophysiology of mitochondria. However, the protective mechanism has not yet been definitively clarified. In the present study, isolated spinal cord mitochondria were incubated with spermine to evaluate its physiological functions and Src kinase activities. The results revealed that spermine increased oxidative phosphorylation, attenuated mitochondrial swelling and maintained the membrane potential. An inhibitor of Src kinases, amino‑5-(4‑chlorophenyl)‑7‑(t‑butyl)pyrazolo[3,4‑d]pyrimidine (PP2), markedly reduced the effects of spermine. However, inhibition of tyrosine phosphatases by vanadate led to marginal increases in the effects of spermine. Therefore, the present study hypothesized that tyrosine phosphorylation sites are present in the subunits of respiratory chains and mitochondrial permeability transition pore proteins, which may be modified via phosphorylation and dephosphorylation. Furthermore, spermine may upregulate the phosphorylation of Src kinases, and PP2 and vanadate conversely regulate Src phosphorylation. The results of the present study suggest that spermine is a strategic regulator within mitochondria that may activate Src kinases in the spinal cord, and tyrosine phosphorylation signaling is a primary regulatory pathway of mitochondrial metabolism.
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Affiliation(s)
- Rui Zhang
- Department of Orthopaedics, The Second Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang 150086, P.R. China
| | - Xin-Nan Ma
- Department of Orthopaedics, The Second Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang 150086, P.R. China
| | - Kai Liu
- Department of Orthopaedics, The Second Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang 150086, P.R. China
| | - Lei Zhang
- Department of Orthopaedics, The Second Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang 150086, P.R. China
| | - Meng Yao
- Department of Orthopaedics, The Second Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang 150086, P.R. China
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Nicholls DG. Brain mitochondrial calcium transport: Origins of the set-point concept and its application to physiology and pathology. Neurochem Int 2017; 109:5-12. [PMID: 28057556 DOI: 10.1016/j.neuint.2016.12.018] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Revised: 12/27/2016] [Accepted: 12/30/2016] [Indexed: 11/26/2022]
Abstract
The transport of calcium across the inner mitochondrial membrane plays a key role in neuronal physiology and pathology. The kinetic responses of the uniporter and efflux pathways are such that a cytosolic free calcium 'set-point' can be established - above which there is net calcium accumulation into the matrix that is reversed when plasma membrane transport lowers cytosolic calcium. Pathological activation of N-methyl-d-aspartate receptor mediated sodium and calcium entry into the neuron, as occurs in stroke and spreading depression, places severe demands on both the ATP-generating and calcium loading capacities of the neuronal mitochondria as the set-point is exceeded. Experiments that led to the concept of the set-point are reviewed.
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Affiliation(s)
- David G Nicholls
- Buck Institute for Research on Aging, 8001 Redwood Bld., Novato, CA 94945, United States.
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Curcio M, Salazar IL, Mele M, Canzoniero LMT, Duarte CB. Calpains and neuronal damage in the ischemic brain: The swiss knife in synaptic injury. Prog Neurobiol 2016; 143:1-35. [PMID: 27283248 DOI: 10.1016/j.pneurobio.2016.06.001] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Revised: 03/22/2016] [Accepted: 05/09/2016] [Indexed: 12/26/2022]
Abstract
The excessive extracellular accumulation of glutamate in the ischemic brain leads to an overactivation of glutamate receptors with consequent excitotoxic neuronal death. Neuronal demise is largely due to a sustained activation of NMDA receptors for glutamate, with a consequent increase in the intracellular Ca(2+) concentration and activation of calcium- dependent mechanisms. Calpains are a group of Ca(2+)-dependent proteases that truncate specific proteins, and some of the cleavage products remain in the cell, although with a distinct function. Numerous studies have shown pre- and post-synaptic effects of calpains on glutamatergic and GABAergic synapses, targeting membrane- associated proteins as well as intracellular proteins. The resulting changes in the presynaptic proteome alter neurotransmitter release, while the cleavage of postsynaptic proteins affects directly or indirectly the activity of neurotransmitter receptors and downstream mechanisms. These alterations also disturb the balance between excitatory and inhibitory neurotransmission in the brain, with an impact in neuronal demise. In this review we discuss the evidence pointing to a role for calpains in the dysregulation of excitatory and inhibitory synapses in brain ischemia, at the pre- and post-synaptic levels, as well as the functional consequences. Although targeting calpain-dependent mechanisms may constitute a good therapeutic approach for stroke, specific strategies should be developed to avoid non-specific effects given the important regulatory role played by these proteases under normal physiological conditions.
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Affiliation(s)
- Michele Curcio
- CNC - Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504 Coimbra, Portugal
| | - Ivan L Salazar
- CNC - Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504 Coimbra, Portugal; Doctoral Programme in Experimental Biology and Biomedicine, Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504 Coimbra, Portugal; Institute for Interdisciplinary Research, University of Coimbra (IIIUC), 3030-789 Coimbra, Portugal
| | - Miranda Mele
- CNC - Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504 Coimbra, Portugal
| | | | - Carlos B Duarte
- CNC - Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504 Coimbra, Portugal; Department of Life Sciences, University of Coimbra, 3000-456 Coimbra, Portugal.
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Doczi J, Torocsik B, Echaniz-Laguna A, Mousson de Camaret B, Starkov A, Starkova N, Gál A, Molnár MJ, Kawamata H, Manfredi G, Adam-Vizi V, Chinopoulos C. Alterations in voltage-sensing of the mitochondrial permeability transition pore in ANT1-deficient cells. Sci Rep 2016; 6:26700. [PMID: 27221760 PMCID: PMC4879635 DOI: 10.1038/srep26700] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2015] [Accepted: 05/09/2016] [Indexed: 01/03/2023] Open
Abstract
The probability of mitochondrial permeability transition (mPT) pore opening is inversely related to the magnitude of the proton electrochemical gradient. The module conferring sensitivity of the pore to this gradient has not been identified. We investigated mPT’s voltage-sensing properties elicited by calcimycin or H2O2 in human fibroblasts exhibiting partial or complete lack of ANT1 and in C2C12 myotubes with knocked-down ANT1 expression. mPT onset was assessed by measuring in situ mitochondrial volume using the ‘thinness ratio’ and the ‘cobalt-calcein’ technique. De-energization hastened calcimycin-induced swelling in control and partially-expressing ANT1 fibroblasts, but not in cells lacking ANT1, despite greater losses of mitochondrial membrane potential. Matrix Ca2+ levels measured by X-rhod-1 or mitochondrially-targeted ratiometric biosensor 4mtD3cpv, or ADP-ATP exchange rates did not differ among cell types. ANT1-null fibroblasts were also resistant to H2O2-induced mitochondrial swelling. Permeabilized C2C12 myotubes with knocked-down ANT1 exhibited higher calcium uptake capacity and voltage-thresholds of mPT opening inferred from cytochrome c release, but intact cells showed no differences in calcimycin-induced onset of mPT, irrespective of energization and ANT1 expression, albeit the number of cells undergoing mPT increased less significantly upon chemically-induced hypoxia than control cells. We conclude that ANT1 confers sensitivity of the pore to the electrochemical gradient.
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Affiliation(s)
- Judit Doczi
- Department of Medical Biochemistry, Semmelweis University MTA-SE Laboratory for Neurobiochemistry, Budapest, 1094, Hungary.,MTA-SE Lendület Neurobiochemistry Research Group, Budapest, Hungary
| | - Beata Torocsik
- Department of Medical Biochemistry, Semmelweis University MTA-SE Laboratory for Neurobiochemistry, Budapest, 1094, Hungary
| | - Andoni Echaniz-Laguna
- Département de Neurologie, Hôpitaux Universitaires, Hôpital de Hautepierre, 67098 Strasbourg cedex, France
| | - Bénédicte Mousson de Camaret
- Service des Maladies Héréditaires du Métabolisme, Centre de Biologie et de Pathologie Est, CHU Lyon, 69677 Bron cedex, France
| | - Anatoly Starkov
- Feil Family Brain and Mind Research Institute, Weill Cornell Medical College, New York, NY 10065, USA
| | - Natalia Starkova
- Icahn School of Medicine at Mount Sinai, Department of Hematology and Medical Oncology, New York, NY 10029, USA
| | - Aniko Gál
- Institute of Genomic Medicine and Rare Disorders, Semmelweis University, Budapest, 1083, Hungary
| | - Mária J Molnár
- Institute of Genomic Medicine and Rare Disorders, Semmelweis University, Budapest, 1083, Hungary
| | - Hibiki Kawamata
- Feil Family Brain and Mind Research Institute, Weill Cornell Medical College, New York, NY 10065, USA
| | - Giovanni Manfredi
- Feil Family Brain and Mind Research Institute, Weill Cornell Medical College, New York, NY 10065, USA
| | - Vera Adam-Vizi
- Department of Medical Biochemistry, Semmelweis University MTA-SE Laboratory for Neurobiochemistry, Budapest, 1094, Hungary
| | - Christos Chinopoulos
- Department of Medical Biochemistry, Semmelweis University MTA-SE Laboratory for Neurobiochemistry, Budapest, 1094, Hungary.,MTA-SE Lendület Neurobiochemistry Research Group, Budapest, Hungary
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Rueda CB, Llorente-Folch I, Traba J, Amigo I, Gonzalez-Sanchez P, Contreras L, Juaristi I, Martinez-Valero P, Pardo B, Del Arco A, Satrustegui J. Glutamate excitotoxicity and Ca2+-regulation of respiration: Role of the Ca2+ activated mitochondrial transporters (CaMCs). BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2016; 1857:1158-1166. [PMID: 27060251 DOI: 10.1016/j.bbabio.2016.04.003] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Revised: 04/05/2016] [Accepted: 04/05/2016] [Indexed: 12/21/2022]
Abstract
Glutamate elicits Ca(2+) signals and workloads that regulate neuronal fate both in physiological and pathological circumstances. Oxidative phosphorylation is required in order to respond to the metabolic challenge caused by glutamate. In response to physiological glutamate signals, cytosolic Ca(2+) activates respiration by stimulation of the NADH malate-aspartate shuttle through Ca(2+)-binding to the mitochondrial aspartate/glutamate carrier (Aralar/AGC1/Slc25a12), and by stimulation of adenine nucleotide uptake through Ca(2+) binding to the mitochondrial ATP-Mg/Pi carrier (SCaMC-3/Slc25a23). In addition, after Ca(2+) entry into the matrix through the mitochondrial Ca(2+) uniporter (MCU), it activates mitochondrial dehydrogenases. In response to pathological glutamate stimulation during excitotoxicity, Ca(2+) overload, reactive oxygen species (ROS), mitochondrial dysfunction and delayed Ca(2+) deregulation (DCD) lead to neuronal death. Glutamate-induced respiratory stimulation is rapidly inactivated through a mechanism involving Poly (ADP-ribose) Polymerase-1 (PARP-1) activation, consumption of cytosolic NAD(+), a decrease in matrix ATP and restricted substrate supply. Glutamate-induced Ca(2+)-activation of SCaMC-3 imports adenine nucleotides into mitochondria, counteracting the depletion of matrix ATP and the impaired respiration, while Aralar-dependent lactate metabolism prevents substrate exhaustion. A second mechanism induced by excitotoxic glutamate is permeability transition pore (PTP) opening, which critically depends on ROS production and matrix Ca(2+) entry through the MCU. By increasing matrix content of adenine nucleotides, SCaMC-3 activity protects against glutamate-induced PTP opening and lowers matrix free Ca(2+), resulting in protracted appearance of DCD and protection against excitotoxicity in vitro and in vivo, while the lack of lactate protection during in vivo excitotoxicity explains increased vulnerability to kainite-induced toxicity in Aralar +/- mice. This article is part of a Special Issue entitled 'EBEC 2016: 19th European Bioenergetics Conference, Riva del Garda, Italy, July 2-6, 2016', edited by Prof. Paolo Bernardi.
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Affiliation(s)
- Carlos B Rueda
- Departamento de Biología Molecular, Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid-Consejo Superior de Investigaciones Científicas, 28049 Madrid, Spain; CIBER de Enfermedades Raras (CIBERER), Spain; Instituto de Investigaciones Sanitarias Fundación Jiménez Díaz (IIS-FJD), Spain
| | - Irene Llorente-Folch
- Departamento de Biología Molecular, Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid-Consejo Superior de Investigaciones Científicas, 28049 Madrid, Spain; CIBER de Enfermedades Raras (CIBERER), Spain; Instituto de Investigaciones Sanitarias Fundación Jiménez Díaz (IIS-FJD), Spain
| | - Javier Traba
- Cardiovascular and Pulmonary Branch, NHLBI, NIH, 20892 Bethesda, MD, USA
| | - Ignacio Amigo
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, 13560-970 São Paulo, Brazil
| | - Paloma Gonzalez-Sanchez
- Departamento de Biología Molecular, Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid-Consejo Superior de Investigaciones Científicas, 28049 Madrid, Spain; CIBER de Enfermedades Raras (CIBERER), Spain; Instituto de Investigaciones Sanitarias Fundación Jiménez Díaz (IIS-FJD), Spain
| | - Laura Contreras
- Departamento de Biología Molecular, Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid-Consejo Superior de Investigaciones Científicas, 28049 Madrid, Spain; CIBER de Enfermedades Raras (CIBERER), Spain; Instituto de Investigaciones Sanitarias Fundación Jiménez Díaz (IIS-FJD), Spain
| | - Inés Juaristi
- Departamento de Biología Molecular, Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid-Consejo Superior de Investigaciones Científicas, 28049 Madrid, Spain; CIBER de Enfermedades Raras (CIBERER), Spain; Instituto de Investigaciones Sanitarias Fundación Jiménez Díaz (IIS-FJD), Spain
| | - Paula Martinez-Valero
- Departamento de Biología Molecular, Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid-Consejo Superior de Investigaciones Científicas, 28049 Madrid, Spain; CIBER de Enfermedades Raras (CIBERER), Spain; Instituto de Investigaciones Sanitarias Fundación Jiménez Díaz (IIS-FJD), Spain
| | - Beatriz Pardo
- Departamento de Biología Molecular, Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid-Consejo Superior de Investigaciones Científicas, 28049 Madrid, Spain; CIBER de Enfermedades Raras (CIBERER), Spain; Instituto de Investigaciones Sanitarias Fundación Jiménez Díaz (IIS-FJD), Spain
| | - Araceli Del Arco
- Departamento de Biología Molecular, Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid-Consejo Superior de Investigaciones Científicas, 28049 Madrid, Spain; CIBER de Enfermedades Raras (CIBERER), Spain; Instituto de Investigaciones Sanitarias Fundación Jiménez Díaz (IIS-FJD), Spain; Facultad de Ciencias Ambientales y Bioquímica, Universidad de Castilla la Mancha, Toledo 45071, Spain
| | - Jorgina Satrustegui
- Departamento de Biología Molecular, Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid-Consejo Superior de Investigaciones Científicas, 28049 Madrid, Spain; CIBER de Enfermedades Raras (CIBERER), Spain; Instituto de Investigaciones Sanitarias Fundación Jiménez Díaz (IIS-FJD), Spain
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Seifert EL, Ligeti E, Mayr JA, Sondheimer N, Hajnóczky G. The mitochondrial phosphate carrier: Role in oxidative metabolism, calcium handling and mitochondrial disease. Biochem Biophys Res Commun 2015; 464:369-75. [PMID: 26091567 DOI: 10.1016/j.bbrc.2015.06.031] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The mitochondrial phosphate carrier (PiC) is a mitochondrial solute carrier protein, which is encoded by SLC25A3 in humans. PiC delivers phosphate, a key substrate of oxidative phosphorylation, across the inner mitochondrial membrane. This transport activity is also relevant for allowing effective mitochondrial calcium handling. Furthermore, PiC has also been described to affect cell survival mechanisms via interactions with cyclophilin D and the viral mitochondrial-localized inhibitor of apoptosis (vMIA). The significance of PiC has been supported by the recent discovery of a fatal human condition associated with PiC mutations. Here, we present first the early studies that lead to the discovery and molecular characterization of the PiC, then discuss the very recently developed mouse models for PiC and pathological mutations in the human SLC25A3 gene.
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Affiliation(s)
- Erin L Seifert
- MitoCare Center, Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA.
| | - Erzsébet Ligeti
- Department of Physiology, Semmelweis University, Budapest 1085, Hungary
| | - Johannes A Mayr
- Department of Paediatrics, Paracelsus Medical University, SALK Salzburg, Salzburg 5020, Austria
| | - Neal Sondheimer
- Department of Pediatrics, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - György Hajnóczky
- MitoCare Center, Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA.
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Gurung P, Lukens JR, Kanneganti TD. Mitochondria: diversity in the regulation of the NLRP3 inflammasome. Trends Mol Med 2015; 21:193-201. [PMID: 25500014 PMCID: PMC4352396 DOI: 10.1016/j.molmed.2014.11.008] [Citation(s) in RCA: 272] [Impact Index Per Article: 30.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2014] [Revised: 11/20/2014] [Accepted: 11/21/2014] [Indexed: 12/20/2022]
Abstract
Recent studies have identified new roles for mitochondria in the regulation of autoinflammatory processes. Emerging data suggests that the release of danger signals from mitochondria in response to stress and infection promotes the formation of the inflammatory signaling platform known as inflammasomes. Activation of inflammasomes by damaged mitochondria results in caspase-1-dependent secretion of the inflammatory cytokines interleukin-1β (IL-1β) and IL-18, and an inflammatory form of cell death referred to as pyroptosis. Here, we review recently described mechanisms that have been proposed to be involved in mitochondria-mediated regulation of inflammasome activation and inflammation. In addition, we highlight how aberrant regulation of mitochondria-induced inflammasome activation centrally contributes to the inflammatory process that is responsible for obesity and associated metabolic diseases.
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Affiliation(s)
- Prajwal Gurung
- Department of Immunology, St Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - John R Lukens
- Department of Immunology, St Jude Children's Research Hospital, Memphis, TN 38105, USA; Center for Brain Immunology and Glia (BIG), Department of Neuroscience, University of Virginia, Charlottesville, VA 22908, USA
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Scola G, Andreazza AC. Oxidative Stress in Bipolar Disorder. OXIDATIVE STRESS IN APPLIED BASIC RESEARCH AND CLINICAL PRACTICE 2015. [DOI: 10.1007/978-1-4939-0440-2_3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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34
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Scola G, Laliberte VLM, Kim HK, Pinguelo A, Salvador M, Young LT, Andreazza AC. Vitis labrusca extract effects on cellular dynamics and redox modulations in a SH-SY5Y neuronal cell model: A similar role to lithium. Neurochem Int 2014; 79:12-9. [DOI: 10.1016/j.neuint.2014.10.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2014] [Revised: 09/12/2014] [Accepted: 10/06/2014] [Indexed: 02/06/2023]
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35
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Mühling T, Duda J, Weishaupt JH, Ludolph AC, Liss B. Elevated mRNA-levels of distinct mitochondrial and plasma membrane Ca(2+) transporters in individual hypoglossal motor neurons of endstage SOD1 transgenic mice. Front Cell Neurosci 2014; 8:353. [PMID: 25452714 PMCID: PMC4231948 DOI: 10.3389/fncel.2014.00353] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Accepted: 10/08/2014] [Indexed: 12/13/2022] Open
Abstract
Disturbances in Ca2+ homeostasis and mitochondrial dysfunction have emerged as major pathogenic features in familial and sporadic forms of Amyotrophic Lateral Sclerosis (ALS), a fatal degenerative motor neuron disease. However, the distinct molecular ALS-pathology remains unclear. Recently, an activity-dependent Ca2+ homeostasis deficit, selectively in highly vulnerable cholinergic motor neurons in the hypoglossal nucleus (hMNs) from a common ALS mouse model, the endstage superoxide dismutase SOD1G93A transgenic mouse, was described. This functional deficit was defined by a reduced hMN mitochondrial Ca2+ uptake capacity and elevated Ca2+ extrusion across the plasma membrane. To address the underlying molecular mechanisms, here we quantified mRNA-levels of respective potential mitochondrial and plasma membrane Ca2+ transporters in individual, choline-acetyltransferase (ChAT) positive hMNs from wildtype (WT) and endstage SOD1G93A mice, by combining UV laser microdissection with RT-qPCR techniques, and specific data normalization. As ChAT cDNA levels as well as cDNA and genomic DNA levels of the mitochondrially encoded NADH dehydrogenase ND1 were not different between hMNs from WT and endstage SOD1G93A mice, these genes were used to normalize hMN-specific mRNA-levels of plasma membrane and mitochondrial Ca2+ transporters, respectively. We detected about 2-fold higher levels of the mitochondrial Ca2+ transporters MCU/MICU1, Letm1, and UCP2 in remaining hMNs from endstage SOD1G93A mice. These higher expression-levels of mitochondrial Ca2+ transporters in individual hMNs were not associated with a respective increase in number of mitochondrial genomes, as evident from hMN specific ND1 DNA quantification. Normalized mRNA-levels for the plasma membrane Na+/Ca2+ exchanger NCX1 were also about 2-fold higher in hMNs from SOD1G93A mice. Thus, pharmacological stimulation of Ca2+ transporters in highly vulnerable hMNs might offer a neuroprotective strategy for ALS.
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Affiliation(s)
- Tobias Mühling
- Department of Applied Physiology, Institute of Applied Physiology, Ulm University Ulm, Germany
| | - Johanna Duda
- Department of Applied Physiology, Institute of Applied Physiology, Ulm University Ulm, Germany
| | | | | | - Birgit Liss
- Department of Applied Physiology, Institute of Applied Physiology, Ulm University Ulm, Germany
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Gilon P, Chae HY, Rutter GA, Ravier MA. Calcium signaling in pancreatic β-cells in health and in Type 2 diabetes. Cell Calcium 2014; 56:340-61. [DOI: 10.1016/j.ceca.2014.09.001] [Citation(s) in RCA: 116] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Revised: 08/26/2014] [Accepted: 09/01/2014] [Indexed: 12/24/2022]
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Power A, Pearson N, Pham T, Cheung C, Phillips A, Hickey A. Uncoupling of oxidative phosphorylation and ATP synthase reversal within the hyperthermic heart. Physiol Rep 2014; 2:2/9/e12138. [PMID: 25263202 PMCID: PMC4270237 DOI: 10.14814/phy2.12138] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Heart failure is a common cause of death with hyperthermia, and the exact cause of hyperthermic heart failure appears elusive. We hypothesize that the energy supply (ATP) of the heart may become impaired due to increased inner‐mitochondrial membrane permeability and inefficient oxidative phosphorylation (OXPHOS). Therefore, we assessed isolated working heart and mitochondrial function. Ex vivo working rat hearts were perfused between 37 and 43.5°C and showed break points in all functional parameters at ~40.5°C. Mitochondrial high‐resolution respirometry coupled to fluorometry was employed to determine the effects of hyperthermia on OXPHOS and mitochondrial membrane potential (ΔΨ) in vitro using a comprehensive metabolic substrate complement with isolated mitochondria. Relative to 37 and 40°C, 43°C elevated Leak O2 flux and depressed OXPHOS O2 flux and ∆Ψ. Measurement of steady‐state ATP production from mitochondria revealed decreased ATP synthesis capacity, and a negative steady‐state P:O ratio at 43°C. This approach offers a more powerful analysis of the effects of temperature on OXPHOS that cannot be measured using simple measures such as the traditional respiratory control ratio (RCR) or P:O ratio, which, respectively, can only approach 1 or 0 with inner‐membrane failure. At 40°C there was only a slight enhancement of the Leak O2 flux and this did not significantly affect ATP production rate. Therefore, during mild hyperthermia (40°C) there is no enhancement of ATP supply by mitochondria, to accompany increasing cardiac energy demands, while between this and critical hyperthermia (43°C), mitochondria become net consumers of ATP. This consumption may contribute to cardiac failure or permanent damage during severe hyperthermia. e12138 Intact cardiac function is crucial, and is particularly important for mediating thermoregulation in hyperthermic states. However, the heart's aerobic metabolism is also thermally sensitive, and may become limited at extreme physiological temperatures. We have shown that at 43°C there is a loss of mitochondrial membrane potential, and this subsequently drives a reversal of the mitochondrial the F1F0‐ATP synthase where it becomes a net consumer of ATP.
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Affiliation(s)
- Amelia Power
- School of Biological Sciences, Faculty of Science, University of Auckland, Auckland, New Zealand Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Nicholas Pearson
- School of Biological Sciences, Faculty of Science, University of Auckland, Auckland, New Zealand
| | - Toan Pham
- School of Biological Sciences, Faculty of Science, University of Auckland, Auckland, New Zealand
| | - Carlos Cheung
- School of Biological Sciences, Faculty of Science, University of Auckland, Auckland, New Zealand
| | - Anthony Phillips
- School of Biological Sciences, Faculty of Science, University of Auckland, Auckland, New Zealand Department of Surgery, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand Maurice Wilkins Center, University of Auckland, Auckland, New Zealand
| | - Anthony Hickey
- School of Biological Sciences, Faculty of Science, University of Auckland, Auckland, New Zealand Maurice Wilkins Center, University of Auckland, Auckland, New Zealand
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Tadic V, Prell T, Lautenschlaeger J, Grosskreutz J. The ER mitochondria calcium cycle and ER stress response as therapeutic targets in amyotrophic lateral sclerosis. Front Cell Neurosci 2014; 8:147. [PMID: 24910594 PMCID: PMC4039088 DOI: 10.3389/fncel.2014.00147] [Citation(s) in RCA: 87] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2014] [Accepted: 05/07/2014] [Indexed: 12/12/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by progressive loss of upper and lower motor neurons. Although the etiology remains unclear, disturbances in calcium homoeostasis and protein folding are essential features of neurodegeneration in this disorder. Here, we review recent research findings on the interaction between endoplasmic reticulum (ER) and mitochondria, and its effect on calcium signaling and oxidative stress. We further provide insights into studies, providing evidence that structures of the ER mitochondria calcium cycle serve as a promising targets for therapeutic approaches for treatment of ALS.
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Affiliation(s)
- Vedrana Tadic
- Hans Berger Department of Neurology, Jena University HospitalJena, Germany
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Kiss G, Konrad C, Pour-Ghaz I, Mansour JJ, Németh B, Starkov AA, Adam-Vizi V, Chinopoulos C. Mitochondrial diaphorases as NAD⁺ donors to segments of the citric acid cycle that support substrate-level phosphorylation yielding ATP during respiratory inhibition. FASEB J 2014; 28:1682-97. [PMID: 24391134 DOI: 10.1096/fj.13-243030] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Substrate-level phosphorylation mediated by succinyl-CoA ligase in the mitochondrial matrix produces high-energy phosphates in the absence of oxidative phosphorylation. Furthermore, when the electron transport chain is dysfunctional, provision of succinyl-CoA by the α-ketoglutarate dehydrogenase complex (KGDHC) is crucial for maintaining the function of succinyl-CoA ligase yielding ATP, preventing the adenine nucleotide translocase from reversing. We addressed the source of the NAD(+) supply for KGDHC under anoxic conditions and inhibition of complex I. Using pharmacologic tools and specific substrates and by examining tissues from pigeon liver exhibiting no diaphorase activity, we showed that mitochondrial diaphorases in the mouse liver contribute up to 81% to the NAD(+) pool during respiratory inhibition. Under these conditions, KGDHC's function, essential for the provision of succinyl-CoA to succinyl-CoA ligase, is supported by NAD(+) derived from diaphorases. Through this process, diaphorases contribute to the maintenance of substrate-level phosphorylation during respiratory inhibition, which is manifested in the forward operation of adenine nucleotide translocase. Finally, we show that reoxidation of the reducible substrates for the diaphorases is mediated by complex III of the respiratory chain.
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Affiliation(s)
- Gergely Kiss
- 1Department of Medical Biochemistry, Semmelweis University, 37-47 Tuzolto Street, Budapest 1094, Hungary.
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ADP protects cardiac mitochondria under severe oxidative stress. PLoS One 2013; 8:e83214. [PMID: 24349464 PMCID: PMC3862761 DOI: 10.1371/journal.pone.0083214] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2013] [Accepted: 10/31/2013] [Indexed: 12/31/2022] Open
Abstract
ADP is not only a key substrate for ATP generation, but also a potent inhibitor of mitochondrial permeability transition pore (mPTP). In this study, we assessed how oxidative stress affects the potency of ADP as an mPTP inhibitor and whether its reduction of reactive oxygen species (ROS) production might be involved. We determined quantitatively the effects of ADP on mitochondrial Ca(2+) retention capacity (CRC) until the induction of mPTP in normal and stressed isolated cardiac mitochondria. We used two models of chronic oxidative stress (old and diabetic mice) and two models of acute oxidative stress (ischemia reperfusion (IR) and tert-butyl hydroperoxide (t-BH)). In control mitochondria, the CRC was 344 ± 32 nmol/mg protein. 500 μmol/L ADP increased CRC to 774 ± 65 nmol/mg protein. This effect of ADP seemed to relate to its concentration as 50 μmol/L had a significantly smaller effect. Also, oligomycin, which inhibits the conversion of ADP to ATP by F0F1ATPase, significantly increased the effect of 50 μmol/L ADP. Chronic oxidative stress did not affect CRC or the effect of 500 μmol/L ADP. After IR or t-BH exposure, CRC was drastically reduced to 1 ± 0.2 and 32 ± 4 nmol/mg protein, respectively. Surprisingly, ADP increased the CRC to 447 ± 105 and 514 ± 103 nmol/mg protein in IR and t-BH, respectively. Thus, it increased CRC by the same amount as in control. In control mitochondria, ADP decreased both substrate and Ca(2+)-induced increase of ROS. However, in t-BH mitochondria the effect of ADP on ROS was relatively small. We conclude that ADP potently restores CRC capacity in severely stressed mitochondria. This effect is most likely not related to a reduction in ROS production. As the effect of ADP relates to its concentration, increased ADP as occurs in the pathophysiological situation may protect mitochondrial integrity and function.
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Cummins N, Bartlett CA, Archer M, Bartlett E, Hemmi JM, Harvey AR, Dunlop SA, Fitzgerald M. Changes to mitochondrial ultrastructure in optic nerve vulnerable to secondary degeneration in vivo are limited by irradiation at 670 nm. BMC Neurosci 2013; 14:98. [PMID: 24011177 PMCID: PMC3844486 DOI: 10.1186/1471-2202-14-98] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2013] [Accepted: 09/03/2013] [Indexed: 11/10/2022] Open
Abstract
Background Traumatic injury to the central nervous system results in damage to tissue beyond the primary injury, termed secondary degeneration. Key events thought to be associated with secondary degeneration involve aspects of mitochondrial function which may be modulated by red/near-infrared irradiation therapy (R/NIR-IT), but precisely how mitochondria are affected in vivo has not been investigated. Secondary degeneration was modelled by transecting the dorsal aspect of the optic nerve in adult rats and mitochondrial ultrastructure in intact ventral optic nerve vulnerable to secondary degeneration investigated with transmission electron microscopy. Results Despite reported increases in fission following central nervous system injury, we saw no change in mitochondrial densities in optic nerve vulnerable to secondary degeneration in vivo. However, in axons, frequency distributions of mitochondrial profile areas showed higher cumulative probabilities of smaller mitochondrial profiles at day 1 after injury. Glial mitochondrial profiles did not exhibit changes in area, but a more elliptical mitochondrial shape was observed at both day 1 and 7 following injury. Importantly, mitochondrial autophagic profiles were observed at days 1 and 7 in optic nerve vulnerable to secondary degeneration in vivo. Citrate synthase activity was used as an additional measure of mitochondrial mass in ventral optic nerve and was decreased at day 7, whereas mitochondrial aconitase activity increased at day 1 and day 28 after injury in optic nerve vulnerable to secondary degeneration. R/NIR-IT has been used to treat the injured central nervous system, with reported improvements in oxidative metabolism suggesting mitochondrial involvement, but ultrastructural information is lacking. Here we show that R/NIR-IT of injured animals resulted in distributions of mitochondrial areas and shape not significantly different from control and significantly reduced mitochondrial autophagic profiles. R/NIR-IT also resulted in decreased citrate synthase activity (day 7) and increased aconitase activity (day 1) in optic nerve vulnerable to secondary degeneration. Conclusions These findings suggest that mitochondrial structure and activity of enzymes of the citric acid cycle are dynamically altered during secondary degeneration in vivo and R/NIR-IT may protect mitochondrial structure.
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Affiliation(s)
- Nadia Cummins
- Experimental and Regenerative Neurosciences, The University of Western Australia, Crawley 6009, WA, Australia.
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42
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Prell T, Lautenschläger J, Grosskreutz J. Calcium-dependent protein folding in amyotrophic lateral sclerosis. Cell Calcium 2013; 54:132-43. [DOI: 10.1016/j.ceca.2013.05.007] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Revised: 05/16/2013] [Accepted: 05/18/2013] [Indexed: 12/25/2022]
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43
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Mitochondrial trafficking in neuropsychiatric diseases. Neurobiol Dis 2013; 51:66-71. [DOI: 10.1016/j.nbd.2012.06.015] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2012] [Revised: 06/07/2012] [Accepted: 06/22/2012] [Indexed: 12/31/2022] Open
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Amigo I, Traba J, González-Barroso MM, Rueda CB, Fernández M, Rial E, Sánchez A, Satrústegui J, Del Arco A. Glucagon regulation of oxidative phosphorylation requires an increase in matrix adenine nucleotide content through Ca2+ activation of the mitochondrial ATP-Mg/Pi carrier SCaMC-3. J Biol Chem 2013; 288:7791-7802. [PMID: 23344948 DOI: 10.1074/jbc.m112.409144] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
It has been known for a long time that mitochondria isolated from hepatocytes treated with glucagon or Ca(2+)-mobilizing agents such as phenylephrine show an increase in their adenine nucleotide (AdN) content, respiratory activity, and calcium retention capacity (CRC). Here, we have studied the role of SCaMC-3/slc25a23, the mitochondrial ATP-Mg/Pi carrier present in adult mouse liver, in the control of mitochondrial AdN levels and respiration in response to Ca(2+) signals as a candidate target of glucagon actions. With the use of SCaMC-3 knock-out (KO) mice, we have found that the carrier is responsible for the accumulation of AdNs in liver mitochondria in a strictly Ca(2+)-dependent way with an S0.5 for Ca(2+) activation of 3.3 ± 0.9 μm. Accumulation of matrix AdNs allows a SCaMC-3-dependent increase in CRC. In addition, SCaMC-3-dependent accumulation of AdNs is required to acquire a fully active state 3 respiration in AdN-depleted liver mitochondria, although further accumulation of AdNs is not followed by increases in respiration. Moreover, glucagon addition to isolated hepatocytes increases oligomycin-sensitive oxygen consumption and maximal respiratory rates in cells derived from wild type, but not SCaMC-3-KO mice and glucagon administration in vivo results in an increase in AdN content, state 3 respiration and CRC in liver mitochondria in wild type but not in SCaMC-3-KO mice. These results show that SCaMC-3 is required for the increase in oxidative phosphorylation observed in liver mitochondria in response to glucagon and Ca(2+)-mobilizing agents, possibly by allowing a Ca(2+)-dependent accumulation of mitochondrial AdNs and matrix Ca(2+), events permissive for other glucagon actions.
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Affiliation(s)
- Ignacio Amigo
- Departmento de Biología Molecular, Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid-CSIC; Centro de Investigaciones Biomédicas en Red de Enfermedades Raras (CIBERER) 28049 Madrid
| | - Javier Traba
- Departmento de Biología Molecular, Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid-CSIC; Centro de Investigaciones Biomédicas en Red de Enfermedades Raras (CIBERER) 28049 Madrid
| | - M Mar González-Barroso
- Departamento de Medicina Celular y Molecular, Centro de Investigaciones Biológicas (CIB), Consejo Superior de Investigaciones Científicas 28040 Madrid
| | - Carlos B Rueda
- Departmento de Biología Molecular, Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid-CSIC; Centro de Investigaciones Biomédicas en Red de Enfermedades Raras (CIBERER) 28049 Madrid
| | - Margarita Fernández
- Departamento de Bioquímica y Biología Molecular II, Facultad de Farmacia, Universidad Complutense de Madrid 28040 Madrid
| | - Eduardo Rial
- Departamento de Medicina Celular y Molecular, Centro de Investigaciones Biológicas (CIB), Consejo Superior de Investigaciones Científicas 28040 Madrid
| | - Aránzazu Sánchez
- Departamento de Bioquímica y Biología Molecular II, Facultad de Farmacia, Universidad Complutense de Madrid 28040 Madrid
| | - Jorgina Satrústegui
- Departmento de Biología Molecular, Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid-CSIC; Centro de Investigaciones Biomédicas en Red de Enfermedades Raras (CIBERER) 28049 Madrid.
| | - Araceli Del Arco
- Área de Bioquímica, Centro Regional de Investigaciones Biomédicas, Facultad de Ciencias Ambientales y Bioquímica, Universidad de Castilla La Mancha (UCLM), Avda. Carlos III s/n, Toledo 45071, Spain.
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45
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Wei AC, Liu T, Winslow RL, O'Rourke B. Dynamics of matrix-free Ca2+ in cardiac mitochondria: two components of Ca2+ uptake and role of phosphate buffering. ACTA ACUST UNITED AC 2013; 139:465-78. [PMID: 22641641 PMCID: PMC3362519 DOI: 10.1085/jgp.201210784] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Mitochondrial Ca(2+) uptake is thought to provide an important signal to increase energy production to meet demand but, in excess, can also trigger cell death. The mechanisms defining the relationship between total Ca(2+) uptake, changes in mitochondrial matrix free Ca(2+), and the activation of the mitochondrial permeability transition pore (PTP) are not well understood. We quantitatively measure changes in [Ca(2+)](out) and [Ca(2+)](mito) during Ca(2+) uptake in isolated cardiac mitochondria and identify two components of Ca(2+) influx. [Ca(2+)](mito) recordings revealed that the first, MCU(mode1), required at least 1 µM Ru360 to be completely inhibited, and responded to small Ca(2+) additions in the range of 0.1 to 2 µM with rapid and large changes in [Ca(2+)](mito). The second component, MCU(mode2), was blocked by 100 nM Ru360 and was responsible for the bulk of total Ca(2+) uptake for large Ca(2+) additions in the range of 2 to 10 µM; however, it had little effect on steady-state [Ca(2+)](mito). MCU(mode1) mediates changes in [Ca(2+)](mito) of 10s of μM, even in the presence of 100 nM Ru360, indicating that there is a finite degree of Ca(2+) buffering in the matrix associated with this pathway. In contrast, the much higher Ca(2+) loads evoked by MCU(mode2) activate a secondary dynamic Ca(2+) buffering system consistent with calcium-phosphate complex formation. Increasing P(i) potentiated [Ca(2+)](mito) increases via MCU(mode1) but suppressed [Ca(2+)](mito) changes via MCU(mode2). The results suggest that the role of MCU(mode1) might be to modulate oxidative phosphorylation in response to intracellular Ca(2+) signaling, whereas MCU(mode2) and the dynamic high-capacity Ca(2+) buffering system constitute a Ca(2+) sink function. Interestingly, the trigger for PTP activation is unlikely to be [Ca(2+)](mito) itself but rather a downstream byproduct of total mitochondrial Ca(2+) loading.
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Affiliation(s)
- An-Chi Wei
- Division of Cardiology, Department of Medicine, Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD 21205, USA
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46
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Andreazza AC. Combining redox-proteomics and epigenomics to explain the involvement of oxidative stress in psychiatric disorders. MOLECULAR BIOSYSTEMS 2013; 8:2503-12. [PMID: 22710408 DOI: 10.1039/c2mb25118c] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Psychiatric disorders affect approximately 10% of adults in North-America. The complex nature of these illnesses makes the search for their pathophysiology a challenge. However, studies have consistently shown that mitochondrial dysfunction and oxidative stress are common features across major psychiatric disorders, including bipolar disorder and schizophrenia. Nevertheless, little is known about specific targets of oxidation in the brain. The search for redox sensors (protein targets for oxidation) will offer information about which pathways are regulated by oxidation in psychiatric disorders. Additionally, DNA is also a target for oxidative damage and recently, studies have suggested that oxidation of cytosine and guanosine can serve as an epigenetic modulator by decreasing or preventing further DNA methylation. Therefore, this review aims to discuss how we can use redox-proteomics and epigenomics to help explain the role of oxidative damage in major psychiatric disorders, which may ultimately lead to the identification of targets for development of new medications.
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Affiliation(s)
- Ana Cristina Andreazza
- Department of Psychiatry, University of Toronto, Medical Science Building, Room 4204, 1 King's College Circle, Toronto, ON M5S 1A8, Canada.
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47
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Blomeyer CA, Bazil JN, Stowe DF, Pradhan RK, Dash RK, Camara AKS. Dynamic buffering of mitochondrial Ca2+ during Ca2+ uptake and Na+-induced Ca2+ release. J Bioenerg Biomembr 2012; 45:189-202. [PMID: 23225099 DOI: 10.1007/s10863-012-9483-7] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2012] [Accepted: 10/08/2012] [Indexed: 11/26/2022]
Abstract
In cardiac mitochondria, matrix free Ca(2+) ([Ca(2+)]m) is primarily regulated by Ca(2+) uptake and release via the Ca(2+) uniporter (CU) and Na(+)/Ca(2+) exchanger (NCE) as well as by Ca(2+) buffering. Although experimental and computational studies on the CU and NCE dynamics exist, it is not well understood how matrix Ca(2+) buffering affects these dynamics under various Ca(2+) uptake and release conditions, and whether this influences the stoichiometry of the NCE. To elucidate the role of matrix Ca(2+) buffering on the uptake and release of Ca(2+), we monitored Ca(2+) dynamics in isolated mitochondria by measuring both the extra-matrix free [Ca(2+)] ([Ca(2+)]e) and [Ca(2+)]m. A detailed protocol was developed and freshly isolated mitochondria from guinea pig hearts were exposed to five different [CaCl2] followed by ruthenium red and six different [NaCl]. By using the fluorescent probe indo-1, [Ca(2+)]e and [Ca(2+)]m were spectrofluorometrically quantified, and the stoichiometry of the NCE was determined. In addition, we measured NADH, membrane potential, matrix volume and matrix pH to monitor Ca(2+)-induced changes in mitochondrial bioenergetics. Our [Ca(2+)]e and [Ca(2+)]m measurements demonstrate that Ca(2+) uptake and release do not show reciprocal Ca(2+) dynamics in the extra-matrix and matrix compartments. This salient finding is likely caused by a dynamic Ca(2+) buffering system in the matrix compartment. The Na(+)- induced Ca(2+) release demonstrates an electrogenic exchange via the NCE by excluding an electroneutral exchange. Mitochondrial bioenergetics were only transiently affected by Ca(2+) uptake in the presence of large amounts of CaCl2, but not by Na(+)- induced Ca(2+) release.
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Affiliation(s)
- Christoph A Blomeyer
- Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, WI 53226, USA
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48
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Bazil JN, Blomeyer CA, Pradhan RK, Camara AKS, Dash RK. Modeling the calcium sequestration system in isolated guinea pig cardiac mitochondria. J Bioenerg Biomembr 2012. [PMID: 23180139 DOI: 10.1007/s10863-012-9488-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Under high Ca(2+) load conditions, Ca(2+) concentrations in the extra-mitochondrial and mitochondrial compartments do not display reciprocal dynamics. This is due to a paradoxical increase in the mitochondrial Ca(2+) buffering power as the Ca(2+) load increases. Here we develop and characterize a mechanism of the mitochondrial Ca(2+) sequestration system using an experimental data set from isolated guinea pig cardiac mitochondria. The proposed mechanism elucidates this phenomenon and others in a mathematical framework and is integrated into a previously corroborated model of oxidative phosphorylation including the Na(+)/Ca(2+) cycle. The integrated model reproduces the Ca(2+) dynamics observed in both compartments of the isolated mitochondria respiring on pyruvate after a bolus of CaCl2 followed by ruthenium red and a bolus of NaCl. The model reveals why changes in mitochondrial Ca(2+) concentration of Ca(2+) loaded mitochondria appear significantly mitigated relative to the corresponding extra-mitochondrial Ca(2+) concentration changes after Ca(2+) efflux is initiated. The integrated model was corroborated by simulating the set-point phenomenon. The computational results support the conclusion that the Ca(2+) sequestration system is composed of at least two classes of Ca(2+) buffers. The first class represents prototypical Ca(2+) buffering, and the second class encompasses the complex binding events associated with the formation of amorphous calcium phosphate. With the Ca(2+) sequestration system in mitochondria more precisely defined, computer simulations can aid in the development of innovative therapeutics aimed at addressing the myriad of complications that arise due to mitochondrial Ca(2+) overload.
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Affiliation(s)
- Jason N Bazil
- Biotechnology and Bioengineering Center and Department of Physiology, Medical College of Wisconsin, Milwaukee, WI, USA
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49
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Konrad C, Kiss G, Torocsik B, Adam-Vizi V, Chinopoulos C. Absence of Ca2+-induced mitochondrial permeability transition but presence of bongkrekate-sensitive nucleotide exchange in C. crangon and P. serratus. PLoS One 2012; 7:e39839. [PMID: 22768139 PMCID: PMC3387235 DOI: 10.1371/journal.pone.0039839] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2012] [Accepted: 05/28/2012] [Indexed: 12/22/2022] Open
Abstract
Mitochondria from the embryos of brine shrimp (Artemia franciscana) do not undergo Ca2+-induced permeability transition in the presence of a profound Ca2+ uptake capacity. Furthermore, this crustacean is the only organism known to exhibit bongkrekate-insensitive mitochondrial adenine nucleotide exchange, prompting the conjecture that refractoriness to bongkrekate and absence of Ca2+-induced permeability transition are somehow related phenomena. Here we report that mitochondria isolated from two other crustaceans, brown shrimp (Crangon crangon) and common prawn (Palaemon serratus) exhibited bongkrekate-sensitive mitochondrial adenine nucleotide transport, but lacked a Ca2+-induced permeability transition. Ca2+ uptake capacity was robust in the absence of adenine nucleotides in both crustaceans, unaffected by either bongkrekate or cyclosporin A. Transmission electron microscopy images of Ca2+-loaded mitochondria showed needle-like formations of electron-dense material strikingly similar to those observed in mitochondria from the hepatopancreas of blue crab (Callinectes sapidus) and the embryos of Artemia franciscana. Alignment analysis of the partial coding sequences of the adenine nucleotide translocase (ANT) expressed in Crangon crangon and Palaemon serratus versus the complete sequence expressed in Artemia franciscana reappraised the possibility of the 208-214 amino acid region for conferring sensitivity to bongkrekate. However, our findings suggest that the ability to undergo Ca2+-induced mitochondrial permeability transition and the sensitivity of adenine nucleotide translocase to bongkrekate are not necessarily related phenomena.
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Affiliation(s)
- Csaba Konrad
- Department of Medical Biochemistry, Semmelweis University, Budapest, Hungary
| | - Gergely Kiss
- Department of Medical Biochemistry, Semmelweis University, Budapest, Hungary
| | - Beata Torocsik
- Department of Medical Biochemistry, Semmelweis University, Budapest, Hungary
| | - Vera Adam-Vizi
- Department of Medical Biochemistry, Semmelweis University, Budapest, Hungary
| | - Christos Chinopoulos
- Department of Medical Biochemistry, Semmelweis University, Budapest, Hungary
- * E-mail:
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Bley K, Boorman G, Mohammad B, McKenzie D, Babbar S. A Comprehensive Review of the Carcinogenic and Anticarcinogenic Potential of Capsaicin. Toxicol Pathol 2012; 40:847-73. [DOI: 10.1177/0192623312444471] [Citation(s) in RCA: 139] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Human exposure to capsaicin, the most abundant pungent chili pepper component, is ubiquitous. Evaluation of capsaicin’s carcinogenic potential has produced variable results in in vitro and in vivo genotoxicity and carcinogenicity assays. The capsaicin tested in older studies was often from pepper plant extracts and included other capsaicinoids and diverse impurities. Recent studies utilizing high-purity capsaicin and standardized protocols provide evidence that the genotoxic and carcinogenic potential of capsaicin is quite low and that the purity of capsaicin is important. Several small epidemiological studies suggest a link between capsaicin consumption and stomach or gall bladder cancer, but contamination of capsaicin-containing foods with known carcinogens renders their interpretation problematic. The postulated ability of capsaicin metabolites to damage DNA and promote carcinogenesis remains unsupported. Anticancer activities of capsaicin have been widely reported, as it inhibits the activity of carcinogens and induces apoptosis in numerous cancer cell lines in vitro and explanted into rodents. Diverse mechanisms have been postulated for capsaicin’s anticancer properties. One hypothesis is that inhibition of cytochrome P450 enzymes—particularly CYP2E1—retards carcinogen activation but is contradicted by the low potency of capsaicin for CYP inhibition. The potential for dietary capsaicin to act as a chemopreventative is now widely postulated.
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Affiliation(s)
- Keith Bley
- NeurogesX, Inc., San Mateo, California, USA
| | - Gary Boorman
- Covance Laboratories Inc., Chantilly, Virginia, USA
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