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Pallafacchina G, Zanin S, Rizzuto R. From the Identification to the Dissection of the Physiological Role of the Mitochondrial Calcium Uniporter: An Ongoing Story. Biomolecules 2021; 11:biom11060786. [PMID: 34071006 PMCID: PMC8224590 DOI: 10.3390/biom11060786] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2021] [Revised: 05/14/2021] [Accepted: 05/20/2021] [Indexed: 12/16/2022] Open
Abstract
The notion of mitochondria being involved in the decoding and shaping of intracellular Ca2+ signals has been circulating since the end of the 19th century. Despite that, the molecular identity of the channel that mediates Ca2+ ion transport into mitochondria remained elusive for several years. Only in the last decade, the genes and pathways responsible for the mitochondrial uptake of Ca2+ began to be cloned and characterized. The gene coding for the pore-forming unit of the mitochondrial channel was discovered exactly 10 years ago, and its product was called mitochondrial Ca2+ uniporter or MCU. Before that, only one of its regulators, the mitochondria Ca2+ uptake regulator 1, MICU1, has been described in 2010. However, in the following years, the scientific interest in mitochondrial Ca2+ signaling regulation and physiological role has increased. This shortly led to the identification of many of its components, to the description of their 3D structure, and the characterization of the uniporter contribution to tissue physiology and pathology. In this review, we will summarize the most relevant achievements in the history of mitochondrial Ca2+ studies, presenting a chronological overview of the most relevant and landmarking discoveries. Finally, we will explore the impact of mitochondrial Ca2+ signaling in the context of muscle physiology, highlighting the recent advances in understanding the role of the MCU complex in the control of muscle trophism and metabolism.
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Affiliation(s)
- Giorgia Pallafacchina
- Department of Biomedical Sciences, University of Padua, 35131 Padua, Italy
- Neuroscience Institute, Italian National Research Council (CNR), 35131 Padua, Italy
- Correspondence: (G.P.); (R.R.); Tel.: +39-049-827-6029 (G.P.); +39-049-827-3001 (R.R.)
| | - Sofia Zanin
- Department of Immunology, Infectiology and Haematology, Institut Necker-Enfants Malades (INEM), INSERM U1151-CNRS UMR 8253, 75015 Paris, France;
| | - Rosario Rizzuto
- Neuroscience Institute, Italian National Research Council (CNR), 35131 Padua, Italy
- Correspondence: (G.P.); (R.R.); Tel.: +39-049-827-6029 (G.P.); +39-049-827-3001 (R.R.)
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52
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Gherardi G, De Mario A, Mammucari C. The mitochondrial calcium homeostasis orchestra plays its symphony: Skeletal muscle is the guest of honor. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2021; 362:209-259. [PMID: 34253296 DOI: 10.1016/bs.ircmb.2021.03.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/03/2023]
Abstract
Skeletal muscle mitochondria are placed in close proximity of the sarcoplasmic reticulum (SR), the main intracellular Ca2+ store. During muscle activity, excitation of sarcolemma and of T-tubule triggers the release of Ca2+ from the SR initiating myofiber contraction. The rise in cytosolic Ca2+ determines the opening of the mitochondrial calcium uniporter (MCU), the highly selective channel of the inner mitochondrial membrane (IMM), causing a robust increase in mitochondrial Ca2+ uptake. The Ca2+-dependent activation of TCA cycle enzymes increases the synthesis of ATP required for SERCA activity. Thus, Ca2+ is transported back into the SR and cytosolic [Ca2+] returns to resting levels eventually leading to muscle relaxation. In recent years, thanks to the molecular identification of MCU complex components, the role of mitochondrial Ca2+ uptake in the pathophysiology of skeletal muscle has been uncovered. In this chapter, we will introduce the reader to a general overview of mitochondrial Ca2+ accumulation. We will tackle the key molecular players and the cellular and pathophysiological consequences of mitochondrial Ca2+ dyshomeostasis. In the second part of the chapter, we will discuss novel findings on the physiological role of mitochondrial Ca2+ uptake in skeletal muscle. Finally, we will examine the involvement of mitochondrial Ca2+ signaling in muscle diseases.
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Affiliation(s)
- Gaia Gherardi
- Department of Biomedical Sciences, University of Padua, Padua, Italy
| | - Agnese De Mario
- Department of Biomedical Sciences, University of Padua, Padua, Italy
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53
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Pedersen SF, Flinck M, Pardo LA. The Interplay between Dysregulated Ion Transport and Mitochondrial Architecture as a Dangerous Liaison in Cancer. Int J Mol Sci 2021; 22:ijms22105209. [PMID: 34069047 PMCID: PMC8156689 DOI: 10.3390/ijms22105209] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2021] [Revised: 05/08/2021] [Accepted: 05/11/2021] [Indexed: 02/06/2023] Open
Abstract
Transport of ions and nutrients is a core mitochondrial function, without which there would be no mitochondrial metabolism and ATP production. Both ion homeostasis and mitochondrial phenotype undergo pervasive changes during cancer development, and both play key roles in driving the malignancy. However, the link between these events has been largely ignored. This review comprehensively summarizes and critically discusses the role of the reciprocal relationship between ion transport and mitochondria in crucial cellular functions, including metabolism, signaling, and cell fate decisions. We focus on Ca2+, H+, and K+, which play essential and highly interconnected roles in mitochondrial function and are profoundly dysregulated in cancer. We describe the transport and roles of these ions in normal mitochondria, summarize the changes occurring during cancer development, and discuss how they might impact tumorigenesis.
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Affiliation(s)
- Stine F. Pedersen
- Department of Biology, Faculty of Science, University of Copenhagen, 2100 Copenhagen, Denmark;
- Correspondence: (S.F.P.); (L.A.P.)
| | - Mette Flinck
- Department of Biology, Faculty of Science, University of Copenhagen, 2100 Copenhagen, Denmark;
| | - Luis A. Pardo
- Oncophysiology Group, Max Planck Institute for Experimental Medicine, 37075 Göttingen, Germany
- Correspondence: (S.F.P.); (L.A.P.)
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54
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Hamilton S, Terentyeva R, Clements RT, Belevych AE, Terentyev D. Sarcoplasmic reticulum-mitochondria communication; implications for cardiac arrhythmia. J Mol Cell Cardiol 2021; 156:105-113. [PMID: 33857485 DOI: 10.1016/j.yjmcc.2021.04.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 03/15/2021] [Accepted: 04/05/2021] [Indexed: 12/11/2022]
Abstract
Sudden cardiac death due to ventricular tachyarrhythmias remains the major cause of mortality in the world. Heart failure, diabetic cardiomyopathy, old age-related cardiac dysfunction and inherited disorders are associated with enhanced propensity to malignant cardiac arrhythmias. Both defective mitochondrial function and abnormal intracellular Ca2+ homeostasis have been established as the key contributing factors in the pathophysiology and arrhythmogenesis in these conditions. This article reviews current advances in understanding of bidirectional control of ryanodine receptor-mediated sarcoplasmic reticulum Ca2+ release and mitochondrial function, and how defects in crosstalk between these two organelles increase arrhythmic risk in cardiac disease.
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Affiliation(s)
- Shanna Hamilton
- Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute, Wexner Medical Center, The Ohio State University, Columbus, OH, United States of America
| | - Radmila Terentyeva
- Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute, Wexner Medical Center, The Ohio State University, Columbus, OH, United States of America
| | - Richard T Clements
- Biomedical & Pharmaceutical Sciences, University of Rhode Island, Kingston, RI, United States of America
| | - Andriy E Belevych
- Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute, Wexner Medical Center, The Ohio State University, Columbus, OH, United States of America
| | - Dmitry Terentyev
- Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute, Wexner Medical Center, The Ohio State University, Columbus, OH, United States of America.
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55
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Bustos G, Ahumada-Castro U, Silva-Pavez E, Puebla A, Lovy A, Cesar Cardenas J. The ER-mitochondria Ca 2+ signaling in cancer progression: Fueling the monster. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2021; 363:49-121. [PMID: 34392932 DOI: 10.1016/bs.ircmb.2021.03.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Cancer is a leading cause of death worldwide. All major tumor suppressors and oncogenes are now recognized to have fundamental connections with metabolic pathways. A hallmark feature of cancer cells is a reprogramming of their metabolism even when nutrients are available. Increasing evidence indicates that most cancer cells rely on mitochondrial metabolism to sustain their energetic and biosynthetic demands. Mitochondria are functionally and physically coupled to the endoplasmic reticulum (ER), the major calcium (Ca2+) storage organelle in mammalian cells, through special domains known as mitochondria-ER contact sites (MERCS). In this domain, the release of Ca2+ from the ER is mainly regulated by inositol 1,4,5-trisphosphate (IP3) receptors (IP3Rs), a family of Ca2+ release channels activated by the ligand IP3. IP3R mediated Ca2+ release is transferred to mitochondria through the mitochondrial Ca2+ uniporter (MCU). Once in the mitochondrial matrix, Ca2+ activates several proteins that stimulate mitochondrial performance. The role of IP3R and MCU in cancer, as well as the other proteins that enable the Ca2+ communication between these two organelles is just beginning to be understood. Here, we describe the function of the main players of the ER mitochondrial Ca2+ communication and discuss how this particular signal may contribute to the rise and development of cancer traits.
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Affiliation(s)
- Galdo Bustos
- Faculty of Sciences, Universidad Mayor, Center for Integrative Biology, Santiago, Chile; Geroscience Center for Brain Health and Metabolism, Santiago, Chile
| | - Ulises Ahumada-Castro
- Faculty of Sciences, Universidad Mayor, Center for Integrative Biology, Santiago, Chile; Geroscience Center for Brain Health and Metabolism, Santiago, Chile
| | - Eduardo Silva-Pavez
- Faculty of Sciences, Universidad Mayor, Center for Integrative Biology, Santiago, Chile; Geroscience Center for Brain Health and Metabolism, Santiago, Chile
| | - Andrea Puebla
- Faculty of Sciences, Universidad Mayor, Center for Integrative Biology, Santiago, Chile; Geroscience Center for Brain Health and Metabolism, Santiago, Chile
| | - Alenka Lovy
- Faculty of Sciences, Universidad Mayor, Center for Integrative Biology, Santiago, Chile; Geroscience Center for Brain Health and Metabolism, Santiago, Chile; Department of Neuroscience, Center for Neuroscience Research, Tufts School of Medicine, Boston, MA, United States.
| | - J Cesar Cardenas
- Faculty of Sciences, Universidad Mayor, Center for Integrative Biology, Santiago, Chile; Geroscience Center for Brain Health and Metabolism, Santiago, Chile; Buck Institute for Research on Aging, Novato, CA, United States; Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA, United States.
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56
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Alevriadou BR, Patel A, Noble M, Ghosh S, Gohil VM, Stathopulos PB, Madesh M. Molecular nature and physiological role of the mitochondrial calcium uniporter channel. Am J Physiol Cell Physiol 2021; 320:C465-C482. [PMID: 33296287 PMCID: PMC8260355 DOI: 10.1152/ajpcell.00502.2020] [Citation(s) in RCA: 73] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Revised: 11/23/2020] [Accepted: 11/23/2020] [Indexed: 02/07/2023]
Abstract
Calcium (Ca2+) signaling is critical for cell function and cell survival. Mitochondria play a major role in regulating the intracellular Ca2+ concentration ([Ca2+]i). Mitochondrial Ca2+ uptake is an important determinant of cell fate and governs respiration, mitophagy/autophagy, and the mitochondrial pathway of apoptosis. Mitochondrial Ca2+ uptake occurs via the mitochondrial Ca2+ uniporter (MCU) complex. This review summarizes the present knowledge on the function of MCU complex, regulation of MCU channel, and the role of MCU in Ca2+ homeostasis and human disease pathogenesis. The channel core consists of four MCU subunits and essential MCU regulators (EMRE). Regulatory proteins that interact with them include mitochondrial Ca2+ uptake 1/2 (MICU1/2), MCU dominant-negative β-subunit (MCUb), MCU regulator 1 (MCUR1), and solute carrier 25A23 (SLC25A23). In addition to these proteins, cardiolipin, a mitochondrial membrane-specific phospholipid, has been shown to interact with the channel core. The dynamic interplay between the core and regulatory proteins modulates MCU channel activity after sensing local changes in [Ca2+]i, reactive oxygen species, and other environmental factors. Here, we highlight the structural details of the human MCU heteromeric assemblies and their known roles in regulating mitochondrial Ca2+ homeostasis. MCU dysfunction has been shown to alter mitochondrial Ca2+ dynamics, in turn eliciting cell apoptosis. Changes in mitochondrial Ca2+ uptake have been implicated in pathological conditions affecting multiple organs, including the heart, skeletal muscle, and brain. However, our structural and functional knowledge of this vital protein complex remains incomplete, and understanding the precise role for MCU-mediated mitochondrial Ca2+ signaling in disease requires further research efforts.
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Affiliation(s)
- B Rita Alevriadou
- Department of Biomedical Engineering, Jacobs School of Medicine and Biomedical Sciences and School of Engineering and Applied Sciences, University at Buffalo-State University of New York, Buffalo, New York
| | - Akshar Patel
- Department of Biomedical Engineering, Jacobs School of Medicine and Biomedical Sciences and School of Engineering and Applied Sciences, University at Buffalo-State University of New York, Buffalo, New York
| | - Megan Noble
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada
| | - Sagnika Ghosh
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas
| | - Vishal M Gohil
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas
| | - Peter B Stathopulos
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada
| | - Muniswamy Madesh
- Department of Medicine/Cardiology Division, Center for Precision Medicine, University of Texas Health San Antonio, San Antonio, Texas
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57
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Duran J, Nickel L, Estrada M, Backs J, van den Hoogenhof MMG. CaMKIIδ Splice Variants in the Healthy and Diseased Heart. Front Cell Dev Biol 2021; 9:644630. [PMID: 33777949 PMCID: PMC7991079 DOI: 10.3389/fcell.2021.644630] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Accepted: 02/22/2021] [Indexed: 01/16/2023] Open
Abstract
RNA splicing has been recognized in recent years as a pivotal player in heart development and disease. The Ca2+/calmodulin dependent protein kinase II delta (CaMKIIδ) is a multifunctional Ser/Thr kinase family and generates at least 11 different splice variants through alternative splicing. This enzyme, which belongs to the CaMKII family, is the predominant family member in the heart and functions as a messenger toward adaptive or detrimental signaling in cardiomyocytes. Classically, the nuclear CaMKIIδB and cytoplasmic CaMKIIδC splice variants are described as mediators of arrhythmias, contractile function, Ca2+ handling, and gene transcription. Recent findings also put CaMKIIδA and CaMKIIδ9 as cardinal players in the global CaMKII response in the heart. In this review, we discuss and summarize the new insights into CaMKIIδ splice variants and their (proposed) functions, as well as CaMKII-engineered mouse phenotypes and cardiac dysfunction related to CaMKIIδ missplicing. We also discuss RNA splicing factors affecting CaMKII splicing. Finally, we discuss the translational perspective derived from these insights and future directions on CaMKIIδ splicing research in the healthy and diseased heart.
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Affiliation(s)
- Javier Duran
- Institute of Experimental Cardiology, Heidelberg University, Heidelberg, Germany.,German Center for Cardiovascular Research (DZHK), Partner Site Heidelberg/Mannheim, Heidelberg, Germany
| | - Lennart Nickel
- Institute of Experimental Cardiology, Heidelberg University, Heidelberg, Germany.,German Center for Cardiovascular Research (DZHK), Partner Site Heidelberg/Mannheim, Heidelberg, Germany
| | - Manuel Estrada
- Faculty of Medicine, Institute of Biomedical Sciences, University of Chile, Santiago, Chile
| | - Johannes Backs
- Institute of Experimental Cardiology, Heidelberg University, Heidelberg, Germany.,German Center for Cardiovascular Research (DZHK), Partner Site Heidelberg/Mannheim, Heidelberg, Germany
| | - Maarten M G van den Hoogenhof
- Institute of Experimental Cardiology, Heidelberg University, Heidelberg, Germany.,German Center for Cardiovascular Research (DZHK), Partner Site Heidelberg/Mannheim, Heidelberg, Germany
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58
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Mitochondrial Calcium Signaling in Pancreatic β-Cell. Int J Mol Sci 2021; 22:ijms22052515. [PMID: 33802289 PMCID: PMC7959128 DOI: 10.3390/ijms22052515] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 02/22/2021] [Accepted: 02/26/2021] [Indexed: 12/13/2022] Open
Abstract
Accumulation of calcium in energized mitochondria of pancreatic β-cells is emerging as a crucial process for pancreatic β-cell function. β-cell mitochondria sense and shape calcium signals, linking the metabolism of glucose and other secretagogues to the generation of signals that promote insulin secretion during nutrient stimulation. Here, we describe the role of mitochondrial calcium signaling in pancreatic β-cell function. We report the latest pharmacological and genetic findings, including the first mitochondrial calcium-targeted intervention strategies developed to modulate pancreatic β-cell function and their potential relevance in the context of diabetes.
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59
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Rosencrans WM, Rajendran M, Bezrukov SM, Rostovtseva TK. VDAC regulation of mitochondrial calcium flux: From channel biophysics to disease. Cell Calcium 2021; 94:102356. [PMID: 33529977 PMCID: PMC7914209 DOI: 10.1016/j.ceca.2021.102356] [Citation(s) in RCA: 58] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 01/06/2021] [Accepted: 01/06/2021] [Indexed: 12/14/2022]
Abstract
Voltage-dependent anion channel (VDAC), the most abundant mitochondrial outer membrane protein, is important for a variety of mitochondrial functions including metabolite exchange, calcium transport, and apoptosis. While VDAC's role in shuttling metabolites between the cytosol and mitochondria is well established, there is a growing interest in understanding the mechanisms of its regulation of mitochondrial calcium transport. Here we review the current literature on VDAC's role in calcium signaling, its biophysical properties, physiological function, and pathology focusing on its importance in cardiac diseases. We discuss the specific biophysical properties of the three VDAC isoforms in mammalian cells-VDAC 1, 2, and 3-in relationship to calcium transport and their distinct roles in cell physiology and disease. Highlighting the emerging evidence that cytosolic proteins interact with VDAC and regulate its calcium permeability, we advocate for continued investigation into the VDAC interactome at the contact sites between mitochondria and organelles and its role in mitochondrial calcium transport.
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Affiliation(s)
- William M Rosencrans
- Section on Molecular Transport, Eunice Kennedy Shriver. National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, 20892, United States
| | - Megha Rajendran
- Section on Molecular Transport, Eunice Kennedy Shriver. National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, 20892, United States
| | - Sergey M Bezrukov
- Section on Molecular Transport, Eunice Kennedy Shriver. National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, 20892, United States
| | - Tatiana K Rostovtseva
- Section on Molecular Transport, Eunice Kennedy Shriver. National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, 20892, United States.
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60
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Rysted JE, Lin Z, Walters GC, Rauckhorst AJ, Noterman M, Liu G, Taylor EB, Strack S, Usachev YM. Distinct properties of Ca 2+ efflux from brain, heart and liver mitochondria: The effects of Na +, Li + and the mitochondrial Na +/Ca 2+ exchange inhibitor CGP37157. Cell Calcium 2021; 96:102382. [PMID: 33684833 DOI: 10.1016/j.ceca.2021.102382] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 02/15/2021] [Accepted: 02/18/2021] [Indexed: 10/22/2022]
Abstract
Mitochondrial Ca2+ transport is essential for regulating cell bioenergetics, Ca2+ signaling and cell death. Mitochondria accumulate Ca2+ via the mitochondrial Ca2+ uniporter (MCU), whereas Ca2+ is extruded by the mitochondrial Na+/Ca2+ (mtNCX) and H+/Ca2+ exchangers. The balance between these processes is essential for preventing toxic mitochondrial Ca2+ overload. Recent work demonstrated that MCU activity varies significantly among tissues, likely reflecting tissue-specific Ca2+ signaling and energy needs. It is less clear whether this diversity in MCU activity is matched by tissue-specific diversity in mitochondrial Ca2+ extrusion. Here we compared properties of mitochondrial Ca2+ extrusion in three tissues with prominent mitochondria function: brain, heart and liver. At the transcript level, expression of the Na+/Ca2+/Li+ exchanger (NCLX), which has been proposed to mediate mtNCX transport, was significantly greater in liver than in brain or heart. At the functional level, Na+ robustly activated Ca2+ efflux from brain and heart mitochondria, but not from liver mitochondria. The mtNCX inhibitor CGP37157 blocked Ca2+ efflux from brain and heart mitochondria but had no effect in liver mitochondria. Replacement of Na+ with Li+ to test the involvement of NCLX, resulted in a slowing of mitochondrial Ca2+ efflux by ∼70 %. Collectively, our findings suggest that mtNCX is responsible for Ca2+ extrusion from the mitochondria of the brain and heart, but plays only a small, if any, role in mitochondria of the liver. They also reveal that Li+ is significantly less effective than Na+ in driving mitochondrial Ca2+ efflux.
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Affiliation(s)
- Jacob E Rysted
- Department of Neuroscience and Pharmacology and Iowa Neuroscience Institute, University of Iowa College of Medicine, Iowa City, IA, 52242, USA
| | - Zhihong Lin
- Department of Neuroscience and Pharmacology and Iowa Neuroscience Institute, University of Iowa College of Medicine, Iowa City, IA, 52242, USA
| | - Grant C Walters
- Department of Neuroscience and Pharmacology and Iowa Neuroscience Institute, University of Iowa College of Medicine, Iowa City, IA, 52242, USA
| | - Adam J Rauckhorst
- Department of Molecular Physiology and Biophysics, University of Iowa College of Medicine, Iowa City, IA, 52242, USA
| | - Maria Noterman
- Department of Molecular Physiology and Biophysics, University of Iowa College of Medicine, Iowa City, IA, 52242, USA
| | - Guanghao Liu
- Department of Internal Medicine, University of Iowa College of Medicine, Iowa City, IA, 52242, USA
| | - Eric B Taylor
- Department of Molecular Physiology and Biophysics, University of Iowa College of Medicine, Iowa City, IA, 52242, USA
| | - Stefan Strack
- Department of Neuroscience and Pharmacology and Iowa Neuroscience Institute, University of Iowa College of Medicine, Iowa City, IA, 52242, USA
| | - Yuriy M Usachev
- Department of Neuroscience and Pharmacology and Iowa Neuroscience Institute, University of Iowa College of Medicine, Iowa City, IA, 52242, USA.
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61
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Abstract
Mitochondria are responsible for ATP production but are also known as regulators of cell death, and mitochondrial matrix Ca2+ is a key modulator of both ATP production and cell death. Although mitochondrial Ca2+ uptake and efflux have been studied for over 50 years, it is only in the past decade that the proteins responsible for mitochondrial Ca2+ uptake and efflux have been identified. The identification of the mitochondrial Ca2+ uniporter (MCU) led to an explosion of studies identifying regulators of the MCU. The levels of these regulators vary in a tissue- and disease-specific manner, providing new insight into how mitochondrial Ca2+ is regulated. This review focuses on the proteins responsible for mitochondrial transport and what we have learned from mouse studies with genetic alterations in these proteins.
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Affiliation(s)
- Elizabeth Murphy
- Cardiovascular Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892, USA;
| | - Charles Steenbergen
- Department of Pathology, Johns Hopkins Medicine, Baltimore, Maryland 21287, USA
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62
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Boyman L, Greiser M, Lederer WJ. Calcium influx through the mitochondrial calcium uniporter holocomplex, MCU cx. J Mol Cell Cardiol 2021; 151:145-154. [PMID: 33147447 PMCID: PMC7880866 DOI: 10.1016/j.yjmcc.2020.10.015] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2020] [Revised: 10/20/2020] [Accepted: 10/28/2020] [Indexed: 12/11/2022]
Abstract
Ca2+ flux into the mitochondrial matrix through the MCU holocomplex (MCUcx) has recently been measured quantitatively and with milliseconds resolution for the first time under physiological conditions in both heart and skeletal muscle. Additionally, the dynamic levels of Ca2+ in the mitochondrial matrix ([Ca2+]m) of cardiomyocytes were measured as it was controlled by the balance between influx of Ca2+ into the mitochondrial matrix through MCUcx and efflux through the mitochondrial Na+ / Ca2+ exchanger (NCLX). Under these conditions [Ca2+]m was shown to regulate ATP production by the mitochondria at only a few critical sites. Additional functions attributed to [Ca2+]m continue to be reported in the literature. Here we review the new findings attributed to MCUcx function and provide a framework for understanding and investigating mitochondrial Ca2+ influx features, many of which remain controversial. The properties and functions of the MCUcx subunits that constitute the holocomplex are challenging to tease apart. Such distinct subunits include EMRE, MCUR1, MICUx (i.e. MICU1, MICU2, MICU3), and the pore-forming subunits (MCUpore). Currently, the specific set of functions of each subunit remains non-quantitative and controversial. The more contentious issues are discussed in the context of the newly measured native MCUcx Ca2+ flux from heart and skeletal muscle. These MCUcx Ca2+ flux measurements have been shown to be a highly-regulated, tissue-specific with femto-Siemens Ca2+ conductances and with distinct extramitochondrial Ca2+ ([Ca2+]i) dependencies. These data from cardiac and skeletal muscle mitochondria have been examined quantitatively for their threshold [Ca2+]i levels and for hypothesized gatekeeping function and are discussed in the context of model cell (e.g. HeLa, MEF, HEK293, COS7 cells) measurements. Our new findings on MCUcx dependent matrix [Ca2+]m signaling provide a quantitative basis for on-going and new investigations of the roles of MCUcx in cardiac function ranging from metabolic fuel selection, capillary blood-flow control and the pathological activation of the mitochondrial permeability transition pore (mPTP). Additionally, this review presents the use of advanced new methods that can be readily adapted by any investigator to enable them to carry out quantitative Ca2+ measurements in mitochondria while controlling the inner mitochondrial membrane potential, ΔΨm.
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Affiliation(s)
- Liron Boyman
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD, USA; The Department of Physiology, University of Maryland School of Medicine, Baltimore, MD, USA.
| | - Maura Greiser
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD, USA; The Department of Physiology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - W Jonathan Lederer
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD, USA; The Department of Physiology, University of Maryland School of Medicine, Baltimore, MD, USA.
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63
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Abstract
One of the most fascinating aspects of mitochondria is their remarkable ability to accumulate and store large amounts of calcium in the presence of phosphate leading to mitochondrial calcification. In this paper, we briefly address the mechanisms that regulate mitochondrial calcium homeostasis followed by the extensive review on the formation and characterization of intramitochondrial calcium phosphate granules leading to mitochondrial calcification and its relevance to physiological and pathological calcifications of body tissues.
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Affiliation(s)
- Bhargavi Duvvuri
- Department of Medicine, Division of Rheumatology, University of Washington, Seattle, WA 98195, USA
| | - Christian Lood
- Department of Medicine, Division of Rheumatology, University of Washington, Seattle, WA 98195, USA
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64
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Feno S, Rizzuto R, Raffaello A, Vecellio Reane D. The molecular complexity of the Mitochondrial Calcium Uniporter. Cell Calcium 2020; 93:102322. [PMID: 33264708 DOI: 10.1016/j.ceca.2020.102322] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 11/19/2020] [Accepted: 11/19/2020] [Indexed: 12/20/2022]
Abstract
The role of mitochondria in regulating cellular Ca2+ homeostasis is crucial for the understanding of different cellular functions in physiological and pathological conditions. Nevertheless, the study of this aspect was severely limited by the lack of the molecular identity of the proteins responsible for mitochondrial Ca2+ uptake. In 2011, the discovery of the gene encoding for the Mitochondrial Calcium Uniporter (MCU), the selective channel responsible for mitochondrial Ca2+ uptake, gave rise to an explosion of studies aimed to characterize the composition, the regulation of the channel and its pathophysiological roles. Here, we summarize the recent discoveries on the molecular structure and composition of the MCU complex by providing new insights into the mechanisms that regulate MCU channel activity.
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Affiliation(s)
- Simona Feno
- Department of Biomedical Science, University of Padua, via G. Colombo 3, 35100 Padua, Italy
| | - Rosario Rizzuto
- Department of Biomedical Science, University of Padua, via G. Colombo 3, 35100 Padua, Italy
| | - Anna Raffaello
- Department of Biomedical Science, University of Padua, via G. Colombo 3, 35100 Padua, Italy; Myology Center, University of Padua, via G. Colombo 3, 35100 Padova, Italy.
| | - Denis Vecellio Reane
- Department of Biomedical Science, University of Padua, via G. Colombo 3, 35100 Padua, Italy.
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65
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Gohel D, Singh R. Mitohormesis; Potential implications in neurodegenerative diseases. Mitochondrion 2020; 56:40-46. [PMID: 33220499 DOI: 10.1016/j.mito.2020.11.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2020] [Revised: 10/06/2020] [Accepted: 11/11/2020] [Indexed: 02/07/2023]
Abstract
Mitochondrial dysfunction is known to be associated with neurodegenerative diseases (NDDs), which is a major burden on the society. Therefore, understanding the regulation of mitochondrial dysfunctions and its implication in neurodegeneration has been major goal for exploiting these mechanisms to rescue neuronal death. The crosstalk between mitochondria and nucleus is important for different neuronal functions including axonal branching, energy homeostasis, neuroinflammation and neuronal survival. The decreased mitochondria capacity during progressive neurodegeneration leads to the altered OXPHOS activity and generation of ROS. The ROS levels in narrow physiological range can reprogram nuclear gene expression to enhance the cellular survival by phenomenon called mitohormesis. Here, we have systematically reviewed the existing reports of mitochondrial dysfunctions causing altered ROS levels in NDDs. We further discussed the role of ROS in regulating mitohormesis and emphasized the importance of mitohormesis in neuronal homeostasis. The emerging role of mitohormesis highlights its importance in future studies on intracellular ROS mediated rescue of mitochondrial dysfunction along with other prevailing mechanisms to alleviate neurodegeneration.
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Affiliation(s)
- Dhruv Gohel
- Department of Biochemistry, Faculty of Science, The M.S. University of Baroda, Vadodara 390002, Gujarat, India
| | - Rajesh Singh
- Department of Biochemistry, Faculty of Science, The M.S. University of Baroda, Vadodara 390002, Gujarat, India.
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66
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Gao P, Yan Z, Zhu Z. Mitochondria-Associated Endoplasmic Reticulum Membranes in Cardiovascular Diseases. Front Cell Dev Biol 2020; 8:604240. [PMID: 33240899 PMCID: PMC7680862 DOI: 10.3389/fcell.2020.604240] [Citation(s) in RCA: 69] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Accepted: 10/21/2020] [Indexed: 12/20/2022] Open
Abstract
The endoplasmic reticulum (ER) and mitochondria are physically connected to form dedicated structural domains known as mitochondria-associated ER membranes (MAMs), which participate in fundamental biological processes, including lipid and calcium (Ca2+) homeostasis, mitochondrial dynamics and other related cellular behaviors such as autophagy, ER stress, inflammation and apoptosis. Many studies have proved the importance of MAMs in maintaining the normal function of both organelles, and the abnormal amount, structure or function of MAMs is related to the occurrence of cardiovascular diseases. Here, we review the knowledge regarding the components of MAMs according to their different functions and the specific roles of MAMs in cardiovascular physiology and pathophysiology, focusing on some highly prevalent cardiovascular diseases, including ischemia-reperfusion, diabetic cardiomyopathy, heart failure, pulmonary arterial hypertension and systemic vascular diseases. Finally, we summarize the possible mechanisms of MAM in cardiovascular diseases and put forward some obstacles in the understanding of MAM function we may encounter.
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Affiliation(s)
- Peng Gao
- Department of Hypertension and Endocrinology, Chongqing Institute of Hypertension, Daping Hospital, Army Medical University, Chongqing, China
| | - Zhencheng Yan
- Department of Hypertension and Endocrinology, Chongqing Institute of Hypertension, Daping Hospital, Army Medical University, Chongqing, China
| | - Zhiming Zhu
- Department of Hypertension and Endocrinology, Chongqing Institute of Hypertension, Daping Hospital, Army Medical University, Chongqing, China
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67
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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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68
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Gherardi G, Monticelli H, Rizzuto R, Mammucari C. The Mitochondrial Ca 2+ Uptake and the Fine-Tuning of Aerobic Metabolism. Front Physiol 2020; 11:554904. [PMID: 33117189 PMCID: PMC7575740 DOI: 10.3389/fphys.2020.554904] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Accepted: 09/14/2020] [Indexed: 12/13/2022] Open
Abstract
Recently, the role of mitochondrial activity in high-energy demand organs and in the orchestration of whole-body metabolism has received renewed attention. In mitochondria, pyruvate oxidation, ensured by efficient mitochondrial pyruvate entry and matrix dehydrogenases activity, generates acetyl CoA that enters the TCA cycle. TCA cycle activity, in turn, provides reducing equivalents and electrons that feed the electron transport chain eventually producing ATP. Mitochondrial Ca2+ uptake plays an essential role in the control of aerobic metabolism. Mitochondrial Ca2+ accumulation stimulates aerobic metabolism by inducing the activity of three TCA cycle dehydrogenases. In detail, matrix Ca2+ indirectly modulates pyruvate dehydrogenase via pyruvate dehydrogenase phosphatase 1, and directly activates isocitrate and α-ketoglutarate dehydrogenases. Here, we will discuss the contribution of mitochondrial Ca2+ uptake to the metabolic homeostasis of organs involved in systemic metabolism, including liver, skeletal muscle, and adipose tissue. We will also tackle the role of mitochondrial Ca2+ uptake in the heart, a high-energy consuming organ whose function strictly depends on appropriate Ca2+ signaling.
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Affiliation(s)
- Gaia Gherardi
- Department of Biomedical Sciences, University of Padua, Padua, Italy
| | | | - Rosario Rizzuto
- Department of Biomedical Sciences, University of Padua, Padua, Italy
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69
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Debattisti V, Horn A, Singh R, Seifert EL, Hogarth MW, Mazala DA, Huang KT, Horvath R, Jaiswal JK, Hajnóczky G. Dysregulation of Mitochondrial Ca 2+ Uptake and Sarcolemma Repair Underlie Muscle Weakness and Wasting in Patients and Mice Lacking MICU1. Cell Rep 2020; 29:1274-1286.e6. [PMID: 31665639 PMCID: PMC7007691 DOI: 10.1016/j.celrep.2019.09.063] [Citation(s) in RCA: 68] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Revised: 08/07/2019] [Accepted: 09/20/2019] [Indexed: 01/29/2023] Open
Abstract
Muscle function is regulated by Ca2+, which mediates excitation-contraction coupling, energy metabolism, adaptation to exercise, and sarcolemmal repair. Several of these actions rely on Ca2+ delivery to the mitochondrial matrix via the mitochondrial Ca2+ uniporter, the pore of which is formed by mitochondrial calcium uniporter (MCU). MCU's gatekeeping and cooperative activation are controlled by MICU1. Loss-of-protein mutation in MICU1 causes a neuromuscular disease. To determine the mechanisms underlying the muscle impairments, we used MICU1 patient cells and skeletal muscle-specific MICU1 knockout mice. Both these models show a lower threshold for MCU-mediated Ca2+ uptake. Lack of MICU1 is associated with impaired mitochondrial Ca2+ uptake during excitation-contraction, aerobic metabolism impairment, muscle weakness, fatigue, and myofiber damage during physical activity. MICU1 deficit compromises mitochondrial Ca2+ uptake during sarcolemmal injury, which causes ineffective repair of the damaged myofibers. Thus, dysregulation of mitochondrial Ca2+ uptake hampers myofiber contractile function, likely through energy metabolism and membrane repair.
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Affiliation(s)
- Valentina Debattisti
- MitoCare Center for Mitochondrial Imaging Research and Diagnostics, Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA, USA
| | - Adam Horn
- Center for Genetic Medicine Research, Children's National Health System, 111 Michigan Avenue Northwest, Washington, DC 20010, USA; Department of Genomics and Precision Medicine, George Washington University School of Medicine and Health Sciences, Washington, DC 20052, USA
| | - Raghavendra Singh
- MitoCare Center for Mitochondrial Imaging Research and Diagnostics, Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA, USA
| | - Erin L Seifert
- MitoCare Center for Mitochondrial Imaging Research and Diagnostics, Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA, USA
| | - Marshall W Hogarth
- Center for Genetic Medicine Research, Children's National Health System, 111 Michigan Avenue Northwest, Washington, DC 20010, USA; Department of Genomics and Precision Medicine, George Washington University School of Medicine and Health Sciences, Washington, DC 20052, USA
| | - Davi A Mazala
- Center for Genetic Medicine Research, Children's National Health System, 111 Michigan Avenue Northwest, Washington, DC 20010, USA; Department of Genomics and Precision Medicine, George Washington University School of Medicine and Health Sciences, Washington, DC 20052, USA
| | - Kai Ting Huang
- MitoCare Center for Mitochondrial Imaging Research and Diagnostics, Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA, USA
| | - Rita Horvath
- Wellcome Centre for Mitochondrial Research, Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK
| | - Jyoti K Jaiswal
- Center for Genetic Medicine Research, Children's National Health System, 111 Michigan Avenue Northwest, Washington, DC 20010, USA; Department of Genomics and Precision Medicine, George Washington University School of Medicine and Health Sciences, Washington, DC 20052, USA.
| | - György Hajnóczky
- MitoCare Center for Mitochondrial Imaging Research and Diagnostics, Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA, USA.
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70
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Boyman L, Lederer WJ. How the mitochondrial calcium uniporter complex (MCU cx) works. Proc Natl Acad Sci U S A 2020; 117:22634-22636. [PMID: 32879002 PMCID: PMC7502774 DOI: 10.1073/pnas.2015886117] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Affiliation(s)
- Liron Boyman
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD 21201
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD 21201
| | - W Jonathan Lederer
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD 21201;
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD 21201
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71
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Vais H, Payne R, Paudel U, Li C, Foskett JK. Coupled transmembrane mechanisms control MCU-mediated mitochondrial Ca 2+ uptake. Proc Natl Acad Sci U S A 2020; 117:21731-21739. [PMID: 32801213 PMCID: PMC7474680 DOI: 10.1073/pnas.2005976117] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Ca2+ uptake by mitochondria regulates bioenergetics, apoptosis, and Ca2+ signaling. The primary pathway for mitochondrial Ca2+ uptake is the mitochondrial calcium uniporter (MCU), a Ca2+-selective ion channel in the inner mitochondrial membrane. MCU-mediated Ca2+ uptake is driven by the sizable inner-membrane potential generated by the electron-transport chain. Despite the large thermodynamic driving force, mitochondrial Ca2+ uptake is tightly regulated to maintain low matrix [Ca2+] and prevent opening of the permeability transition pore and cell death, while meeting dynamic cellular energy demands. How this is accomplished is controversial. Here we define a regulatory mechanism of MCU-channel activity in which cytoplasmic Ca2+ regulation of intermembrane space-localized MICU1/2 is controlled by Ca2+-regulatory mechanisms localized across the membrane in the mitochondrial matrix. Ca2+ that permeates through the channel pore regulates Ca2+ affinities of coupled inhibitory and activating sensors in the matrix. Ca2+ binding to the inhibitory sensor within the MCU amino terminus closes the channel despite Ca2+ binding to MICU1/2. Conversely, disruption of the interaction of MICU1/2 with the MCU complex disables matrix Ca2+ regulation of channel activity. Our results demonstrate how Ca2+ influx into mitochondria is tuned by coupled Ca2+-regulatory mechanisms on both sides of the inner mitochondrial membrane.
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Affiliation(s)
- Horia Vais
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Riley Payne
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Usha Paudel
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Carmen Li
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - J Kevin Foskett
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104;
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
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72
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Ali N, Rezvani HR, Motei D, Suleman S, Mahfouf W, Marty I, Ronkainen VP, Vainio SJ. Trisk 95 as a novel skin mirror for normal and diabetic systemic glucose level. Sci Rep 2020; 10:12246. [PMID: 32699238 PMCID: PMC7376074 DOI: 10.1038/s41598-020-68972-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 07/03/2020] [Indexed: 11/21/2022] Open
Abstract
Developing trustworthy, cost effective, minimally or non-invasive glucose sensing strategies is of great need for diabetic patients. In this study, we used an experimental type I diabetic mouse model to examine whether the skin would provide novel means for identifying biomarkers associated with blood glucose level. We first showed that skin glucose levels are rapidly influenced by blood glucose concentrations. We then conducted a proteomic screen of murine skin using an experimental in vivo model of type I diabetes and wild-type controls. Among the proteins that increased expression in response to high blood glucose, Trisk 95 expression was significantly induced independently of insulin signalling. A luciferase reporter assay demonstrated that the induction of Trisk 95 expression occurs at a transcriptional level and is associated with a marked elevation in the Fluo-4AM signal, suggesting a role for intracellular calcium changes in the signalling cascade. Strikingly, these changes lead concurrently to fragmentation of the mitochondria. Moreover, Trisk 95 knockout abolishes both the calcium flux and the mitochondrial phenotype changes indicating dependency of glucose flux in the skin on Trisk 95 function. The data demonstrate that the skin reacts robustly to systemic blood changes, and that Trisk 95 is a promising biomarker for a glucose monitoring assembly.
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Affiliation(s)
- Nsrein Ali
- Laboratory of Developmental Biology, Faculty of Biochemistry and Molecular Medicine, Biocenter Oulu, University of Oulu, Aapistie 5A, 90220, Oulu, Finland. .,Infotech Oulu, University of Oulu, 90220, Oulu, Finland.
| | - Hamid Reza Rezvani
- Inserm, BMGIC, UMR 1035, University of Bordeaux, Bordeaux, France.,Centre de Référence pour les Maladies Rares de la Peau, CHU de Bordeaux, Bordeaux, France
| | - Diana Motei
- Laboratory of Developmental Biology, Faculty of Biochemistry and Molecular Medicine, Biocenter Oulu, University of Oulu, Aapistie 5A, 90220, Oulu, Finland
| | - Sufyan Suleman
- Laboratory of Developmental Biology, Faculty of Biochemistry and Molecular Medicine, Biocenter Oulu, University of Oulu, Aapistie 5A, 90220, Oulu, Finland
| | - Walid Mahfouf
- Inserm, BMGIC, UMR 1035, University of Bordeaux, Bordeaux, France
| | - Isabelle Marty
- Inserm U1216, Grenoble Institut des Neurosciences, University Grenoble, La Tronche, France
| | | | - Seppo J Vainio
- Laboratory of Developmental Biology, Faculty of Biochemistry and Molecular Medicine, Biocenter Oulu, University of Oulu, Aapistie 5A, 90220, Oulu, Finland.,Infotech Oulu, University of Oulu, 90220, Oulu, Finland.,Borealis Biobank of Northern Finland, Oulu University Hospital, Oulu, Finland
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73
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Bevan RJ, Williams PA, Waters CT, Thirgood R, Mui A, Seto S, Good M, Morgan JE, Votruba M, Erchova I. OPA1 deficiency accelerates hippocampal synaptic remodelling and age-related deficits in learning and memory. Brain Commun 2020; 2:fcaa101. [PMID: 33094281 PMCID: PMC7566495 DOI: 10.1093/braincomms/fcaa101] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 04/09/2020] [Accepted: 05/27/2020] [Indexed: 12/13/2022] Open
Abstract
A healthy mitochondrial network is essential for the maintenance of neuronal synaptic integrity. Mitochondrial and metabolic dysfunction contributes to the pathogenesis of many neurodegenerative diseases including dementia. OPA1 is the master regulator of mitochondrial fusion and fission and is likely to play an important role during neurodegenerative events. To explore this, we quantified hippocampal dendritic and synaptic integrity and the learning and memory performance of aged Opa1 haploinsufficient mice carrying the Opa1Q285X mutation (B6; C3-Opa1Q285STOP ; Opa1+/- ). We demonstrate that heterozygous loss of Opa1 results in premature age-related loss of spines in hippocampal pyramidal CA1 neurons and a reduction in synaptic density in the hippocampus. This loss is associated with subtle memory deficits in both spatial novelty and object recognition. We hypothesize that metabolic failure to maintain normal neuronal activity at the level of a single spine leads to premature age-related memory deficits. These results highlight the importance of mitochondrial homeostasis for maintenance of neuronal function during ageing.
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Affiliation(s)
- Ryan J Bevan
- School of Optometry and Vision Sciences, Cardiff University, Maindy Rd, Cardiff, CF24 4HQ, UK
| | - Pete A Williams
- Department of Clinical Neuroscience, Division of Eye and Vision, St. Erik Eye Hospital, Karolinska Institutet, Polhemsgatan 50, 112 82 Stockholm, Sweden
| | - Caroline T Waters
- School of Optometry and Vision Sciences, Cardiff University, Maindy Rd, Cardiff, CF24 4HQ, UK
| | - Rebecca Thirgood
- School of Optometry and Vision Sciences, Cardiff University, Maindy Rd, Cardiff, CF24 4HQ, UK
| | - Amanda Mui
- School of Optometry and Vision Sciences, Cardiff University, Maindy Rd, Cardiff, CF24 4HQ, UK
| | - Sharon Seto
- School of Optometry and Vision Sciences, Cardiff University, Maindy Rd, Cardiff, CF24 4HQ, UK
| | - Mark Good
- School of Psychology, Cardiff University, Tower Building, 70 Park Place, Cardiff, CF10 3AT, UK
| | - James E Morgan
- School of Optometry and Vision Sciences, Cardiff University, Maindy Rd, Cardiff, CF24 4HQ, UK
| | - Marcela Votruba
- School of Optometry and Vision Sciences, Cardiff University, Maindy Rd, Cardiff, CF24 4HQ, UK
| | - Irina Erchova
- School of Optometry and Vision Sciences, Cardiff University, Maindy Rd, Cardiff, CF24 4HQ, UK
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74
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Flicker D, Sancak Y, Mick E, Goldberger O, Mootha VK. Exploring the In Vivo Role of the Mitochondrial Calcium Uniporter in Brown Fat Bioenergetics. Cell Rep 2020; 27:1364-1375.e5. [PMID: 31042465 PMCID: PMC7231522 DOI: 10.1016/j.celrep.2019.04.013] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Revised: 09/28/2018] [Accepted: 04/02/2019] [Indexed: 12/21/2022] Open
Abstract
The mitochondrial calcium uniporter has been proposed to coordinate the organelle’s energetics with calcium signaling. Uniporter current has previously been reported to be extremely high in brown adipose tissue (BAT), yet it remains unknown how the uniporter contributes to BAT physiology. Here, we report the generation and characterization of a mouse model lacking Mcu, the pore forming subunit of the uniporter, specifically in BAT (BAT-Mcu-KO). BAT-Mcu-KO mice lack uniporter-based calcium uptake in BAT mitochondria but exhibit unaffected cold tolerance, diet-induced obesity, and transcriptional response to cold in BAT. Unexpectedly, we found in wild-type animals that cold powerfully activates the ATF4-dependent integrated stress response (ISR) in BAT and up-regulates circulating FGF21 and GDF15, raising the hypothesis that the ISR partly underlies the pleiotropic effects of BAT on systemic metabolism. Our study demonstrates that the uniporter is largely dispensable for BAT thermogenesis and demonstrates activation of the ISR in BAT in response to cold. Flicker et al. generate a mouse lacking mitochondrial calcium uniporter activity in brown fat. They show that the uniporter is dispensable for brown fat bioenergetics. Unexpectedly, they find that in wild type animals, cold stress induces ATF4 signaling in normal brown fat, suggesting a mechanism for cold-induced GDF15 and FGF21 elevation.
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Affiliation(s)
- Daniel Flicker
- Howard Hughes Medical Institute and Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Systems Biology, Harvard Medical School, Boston, MA 02115, USA; Broad Institute, Cambridge, MA 02141, USA
| | - Yasemin Sancak
- Howard Hughes Medical Institute and Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Systems Biology, Harvard Medical School, Boston, MA 02115, USA; Broad Institute, Cambridge, MA 02141, USA.
| | - Eran Mick
- Howard Hughes Medical Institute and Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Systems Biology, Harvard Medical School, Boston, MA 02115, USA; Broad Institute, Cambridge, MA 02141, USA
| | - Olga Goldberger
- Howard Hughes Medical Institute and Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Systems Biology, Harvard Medical School, Boston, MA 02115, USA; Broad Institute, Cambridge, MA 02141, USA
| | - Vamsi K Mootha
- Howard Hughes Medical Institute and Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Systems Biology, Harvard Medical School, Boston, MA 02115, USA; Broad Institute, Cambridge, MA 02141, USA.
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75
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Rossini M, Filadi R. Sarcoplasmic Reticulum-Mitochondria Kissing in Cardiomyocytes: Ca 2+, ATP, and Undisclosed Secrets. Front Cell Dev Biol 2020; 8:532. [PMID: 32671075 PMCID: PMC7332691 DOI: 10.3389/fcell.2020.00532] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2020] [Accepted: 06/05/2020] [Indexed: 12/16/2022] Open
Abstract
In cardiomyocytes, to carry out cell contraction, the distribution, morphology, and dynamic interaction of different cellular organelles are tightly regulated. For instance, the repetitive close apposition between junctional sarcoplasmic reticulum (jSR) and specialized sarcolemma invaginations, called transverse-tubules (TTs), is essential for an efficient excitation-contraction coupling (ECC). Upon an action potential, Ca2+ microdomains, generated in synchrony at the interface between TTs and jSR, underlie the prompt increase in cytosolic Ca2+ concentration, ultimately responsible for cell contraction during systole. This process requires a considerable amount of energy and the active participation of mitochondria, which encompass ∼30% of the cell volume and represent the major source of ATP in the heart. Importantly, in adult cardiomyocytes, mitochondria are distributed in a highly orderly fashion and strategically juxtaposed with SR. By taking advantage of the vicinity to Ca2+ releasing sites, they take up Ca2+ and modulate ATP synthesis according to the specific cardiac workload. Interestingly, with respect to SR, a biased, polarized positioning of mitochondrial Ca2+ uptake/efflux machineries has been reported, hinting the importance of a strictly regulated mitochondrial Ca2+ handling for heart activity. This notion, however, has been questioned by the observation that, in some mouse models, the deficiency of specific molecules, modulating mitochondrial Ca2+ dynamics, triggers non-obvious cardiac phenotypes. This review will briefly summarize the physiological significance of SR-mitochondria apposition in cardiomyocytes, as well as the pathological consequences of an altered organelle communication, focusing on Ca2+ signaling. We will discuss ongoing debates and propose future research directions.
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Affiliation(s)
- Michela Rossini
- Department of Biomedical Sciences, University of Padua, Padua, Italy
| | - Riccardo Filadi
- Department of Biomedical Sciences, University of Padua, Padua, Italy.,Neuroscience Institute - Italian National Research Council (CNR), Padua, Italy
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76
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Shah SI, Ullah G. The Function of Mitochondrial Calcium Uniporter at the Whole-Cell and Single Mitochondrion Levels in WT, MICU1 KO, and MICU2 KO Cells. Cells 2020; 9:E1520. [PMID: 32580385 PMCID: PMC7349584 DOI: 10.3390/cells9061520] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 06/15/2020] [Accepted: 06/16/2020] [Indexed: 01/05/2023] Open
Abstract
Mitochondrial Ca2+ ([Ca2+]M) uptake through its Ca2+ uniporter (MCU) is central to many cell functions such as bioenergetics, spatiotemporal organization of Ca2+ signals, and apoptosis. MCU activity is regulated by several intrinsic proteins including MICU1, MICU2, and EMRE. While significant details about the role of MICU1, MICU2, and EMRE in MCU function have emerged recently, a key challenge for the future experiments is to investigate how these regulatory proteins modulate mitochondrial Ca2+ influx through MCU in intact cells under pathophysiological conditions. This is further complicated by the fact that several variables affecting MCU function change dynamically as cell functions. To overcome this void, we develop a data-driven model that closely replicates the behavior of MCU under a wide range of cytosolic Ca2+ ([Ca2+]C), [Ca2+]M, and mitochondrial membrane potential values in WT, MICU1 knockout (KO), and MICU2 KO cells at the single mitochondrion and whole-cell levels. The model is extended to investigate how MICU1 or MICU2 KO affect mitochondrial function. Moreover, we show how Ca2+ buffering proteins, the separation between mitochondrion and Ca2+-releasing stores, and the duration of opening of Ca2+-releasing channels affect mitochondrial function under different conditions. Finally, we demonstrate an easy extension of the model to single channel function of MCU.
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Affiliation(s)
| | - Ghanim Ullah
- Department of Physics, University of South Florida, Tampa, FL 33647, USA;
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77
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Lee Y, Park J, Lee G, Yoon S, Min CK, Kim TG, Yamamoto T, Kim DH, Lee KW, Eom SH. S92 phosphorylation induces structural changes in the N-terminus domain of human mitochondrial calcium uniporter. Sci Rep 2020; 10:9131. [PMID: 32499574 PMCID: PMC7272466 DOI: 10.1038/s41598-020-65994-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Accepted: 05/08/2020] [Indexed: 01/07/2023] Open
Abstract
The mitochondrial calcium uniporter (MCU) plays essential roles in mitochondrial calcium homeostasis and regulates cellular functions, such as energy synthesis, cell growth, and development. Thus, MCU activity is tightly controlled by its regulators as well as post-translational modification, including phosphorylation by protein kinases such as proline-rich tyrosine kinase 2 (Pyk2) and AMP-activated protein kinase (AMPK). In our in vitro kinase assay, the MCU N-terminal domain (NTD) was phosphorylated by protein kinase C isoforms (PKCβII, PKCδ, and PKCε) localized in the mitochondrial matrix. In addition, we found the conserved S92 was phosphorylated by the PKC isoforms. To reveal the structural effect of MCU S92 phosphorylation (S92p), we determined crystal structures of the MCU NTD of S92E and D119A mutants and analysed the molecular dynamics simulation of WT and S92p. We observed conformational changes of the conserved loop2-loop4 (L2-L4 loops) in MCU NTDS92E, NTDD119A, and NTDS92p due to the breakage of the S92-D119 hydrogen bond. The results suggest that the phosphorylation of S92 induces conformational changes as well as enhancements of the negative charges at the L2-L4 loops, which may affect the dimerization of two MCU-EMRE tetramers.
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Affiliation(s)
- Youngjin Lee
- 0000 0001 1033 9831grid.61221.36School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Buk-gu, Gwangju 61005 Republic of Korea ,0000 0001 1033 9831grid.61221.36Steitz Center for Structural Biology, Gwangju Institute of Science and Technology (GIST), Buk-gu, Gwangju 61005 Republic of Korea ,0000 0004 0636 3099grid.249967.7Infection and Immunity Research Laboratory, Metabolic Regulation Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, 34141 Republic of Korea
| | - Jongseo Park
- 0000 0001 1033 9831grid.61221.36School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Buk-gu, Gwangju 61005 Republic of Korea ,0000 0001 1033 9831grid.61221.36Steitz Center for Structural Biology, Gwangju Institute of Science and Technology (GIST), Buk-gu, Gwangju 61005 Republic of Korea
| | - Gihwan Lee
- 0000 0001 0661 1492grid.256681.eDivision of Life Science, Division of Applied Life Science (BK21 Plus), Plant Molecular Biology and Biotechnology Research Center (PMBBRC), Research Institute of Natural Science (RINS), Gyeongsang National University (GNU), 501 Jinju-daero, Jinju, 52828 Republic of Korea
| | - Sanghwa Yoon
- 0000 0001 0661 1492grid.256681.eDivision of Life Science, Division of Applied Life Science (BK21 Plus), Plant Molecular Biology and Biotechnology Research Center (PMBBRC), Research Institute of Natural Science (RINS), Gyeongsang National University (GNU), 501 Jinju-daero, Jinju, 52828 Republic of Korea
| | - Choon Kee Min
- 0000 0001 1033 9831grid.61221.36School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Buk-gu, Gwangju 61005 Republic of Korea ,0000 0001 1033 9831grid.61221.36Systems Biology Research Center, Gwangju Institute of Science and Technology (GIST), Buk-gu, Gwangju 61005 Republic of Korea
| | - Tae Gyun Kim
- 0000 0001 1033 9831grid.61221.36School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Buk-gu, Gwangju 61005 Republic of Korea ,0000 0001 1033 9831grid.61221.36Steitz Center for Structural Biology, Gwangju Institute of Science and Technology (GIST), Buk-gu, Gwangju 61005 Republic of Korea ,0000 0000 9805 2626grid.250464.1Present Address: Molecular Cryo-Electron Microscopy Unit, Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna, Kunigami 904-0495 Japan
| | - Takenori Yamamoto
- 0000 0001 1092 3579grid.267335.6Institute for Genome Research, Tokushima University, Kuramotocho-3, Tokushima, 770-8503 Japan ,0000 0001 1092 3579grid.267335.6Faculty of Pharmaceutical Sciences, Tokushima University, Shomachi-1, Tokushima, 770-8505 Japan
| | - Do Han Kim
- 0000 0001 1033 9831grid.61221.36School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Buk-gu, Gwangju 61005 Republic of Korea ,0000 0001 1033 9831grid.61221.36Systems Biology Research Center, Gwangju Institute of Science and Technology (GIST), Buk-gu, Gwangju 61005 Republic of Korea
| | - Keun Woo Lee
- 0000 0001 0661 1492grid.256681.eDivision of Life Science, Division of Applied Life Science (BK21 Plus), Plant Molecular Biology and Biotechnology Research Center (PMBBRC), Research Institute of Natural Science (RINS), Gyeongsang National University (GNU), 501 Jinju-daero, Jinju, 52828 Republic of Korea
| | - Soo Hyun Eom
- 0000 0001 1033 9831grid.61221.36School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Buk-gu, Gwangju 61005 Republic of Korea ,0000 0001 1033 9831grid.61221.36Steitz Center for Structural Biology, Gwangju Institute of Science and Technology (GIST), Buk-gu, Gwangju 61005 Republic of Korea
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Liu JC. Is MCU dispensable for normal heart function? J Mol Cell Cardiol 2020; 143:175-183. [PMID: 32389793 PMCID: PMC9477561 DOI: 10.1016/j.yjmcc.2020.04.028] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 04/07/2020] [Accepted: 04/24/2020] [Indexed: 12/14/2022]
Abstract
The uptake of Ca2+ into mitochondria is thought to be an important signal communicating the need for increased energy production. However, dysregulated uptake leading to mitochondrial Ca2+ overload can trigger opening of the mitochondrial permeability transition pore and potentially cell death. Thus mitochondrial Ca2+ entry is regulated via the activity of a Ca2+-selective channel known as the mitochondrial calcium uniporter. The last decade has seen enormous momentum in the discovery of the molecular identities of the multiple proteins comprising the uniporter. Increasing numbers of studies in cultured cells and animal models have provided insight into how disruption of uniporter proteins affects mitochondrial Ca2+ regulation and impacts tissue function and physiology. This review aims to summarize some of these recent findings, particularly in the context of the heart.
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Affiliation(s)
- Julia C Liu
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, MN 55455, USA.
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79
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Blockade of MCU-Mediated Ca 2+ Uptake Perturbs Lipid Metabolism via PP4-Dependent AMPK Dephosphorylation. Cell Rep 2020; 26:3709-3725.e7. [PMID: 30917323 DOI: 10.1016/j.celrep.2019.02.107] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Revised: 12/21/2018] [Accepted: 02/27/2019] [Indexed: 12/11/2022] Open
Abstract
Mitochondrial Ca2+ uniporter (MCU)-mediated Ca2+ uptake promotes the buildup of reducing equivalents that fuel oxidative phosphorylation for cellular metabolism. Although MCU modulates mitochondrial bioenergetics, its function in energy homeostasis in vivo remains elusive. Here we demonstrate that deletion of the Mcu gene in mouse liver (MCUΔhep) and in Danio rerio by CRISPR/Cas9 inhibits mitochondrial Ca2+ (mCa2+) uptake, delays cytosolic Ca2+ (cCa2+) clearance, reduces oxidative phosphorylation, and leads to increased lipid accumulation. Elevated hepatic lipids in MCUΔhep were a direct result of extramitochondrial Ca2+-dependent protein phosphatase-4 (PP4) activity, which dephosphorylates AMPK. Loss of AMPK recapitulates hepatic lipid accumulation without changes in MCU-mediated Ca2+ uptake. Furthermore, reconstitution of active AMPK, or PP4 knockdown, enhances lipid clearance in MCUΔhep hepatocytes. Conversely, gain-of-function MCU promotes rapid mCa2+ uptake, decreases PP4 levels, and reduces hepatic lipid accumulation. Thus, our work uncovers an MCU/PP4/AMPK molecular cascade that links Ca2+ dynamics to hepatic lipid metabolism.
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80
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Bertholet AM, Kirichok Y. Patch-Clamp Analysis of the Mitochondrial H + Leak in Brown and Beige Fat. Front Physiol 2020; 11:326. [PMID: 32351404 PMCID: PMC7174661 DOI: 10.3389/fphys.2020.00326] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Accepted: 03/20/2020] [Indexed: 01/27/2023] Open
Abstract
Mitochondria convert the chemical energy of metabolic substrates into adenosine triphosphate (ATP) and heat. Although ATP production has become a focal point of research in bioenergetics, mitochondrial thermogenesis is also crucial for energy metabolism. Mitochondria generate heat due to H+ leak across the inner mitochondrial membrane (IMM) which is mediated by mitochondrial uncoupling proteins. The mitochondrial H+ leak was first identified, and studied for many decades, using mitochondrial respiration technique. Unfortunately, this method measures H+ leak indirectly, and its precision is insufficient for the rigorous insight into the mitochondrial function at the molecular level. Direct patch-clamp recording of H+ leak would have a significantly higher amplitude and time resolution, but application of the patch-clamp technique to a small subcellular organelle such as mitochondria has been challenging. We developed a method that facilitates patch-clamp recording from the whole IMM, enabling the direct measurement of small H+ leak currents via uncoupling proteins and thus, providing a rigorous understanding of the molecular mechanisms involved. In this paper we cover the methodology of measuring the H+ leak in mitochondria of specialized thermogenic tissues brown and beige fat.
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Affiliation(s)
- Ambre M. Bertholet
- Department of Physiology, University of California, San Francisco, San Francisco, CA, United States
| | - Yuriy Kirichok
- Department of Physiology, University of California, San Francisco, San Francisco, CA, United States
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81
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De Marchi U, Fernandez-Martinez S, de la Fuente S, Wiederkehr A, Santo-Domingo J. Mitochondrial ion channels in pancreatic β-cells: Novel pharmacological targets for the treatment of Type 2 diabetes. Br J Pharmacol 2020; 178:2077-2095. [PMID: 32056196 PMCID: PMC8246559 DOI: 10.1111/bph.15018] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 01/29/2020] [Accepted: 01/31/2020] [Indexed: 12/18/2022] Open
Abstract
Pancreatic beta‐cells are central regulators of glucose homeostasis. By tightly coupling nutrient sensing and granule exocytosis, beta‐cells adjust the secretion of insulin to the circulating blood glucose levels. Failure of beta‐cells to augment insulin secretion in insulin‐resistant individuals leads progressively to impaired glucose tolerance, Type 2 diabetes, and diabetes‐related diseases. Mitochondria play a crucial role in β‐cells during nutrient stimulation, linking the metabolism of glucose and other secretagogues to the generation of signals that promote insulin secretion. Mitochondria are double‐membrane organelles containing numerous channels allowing the transport of ions across both membranes. These channels regulate mitochondrial energy production, signalling, and cell death. The mitochondria of β‐cells express ion channels whose physio/pathological role is underappreciated. Here, we describe the mitochondrial ion channels identified in pancreatic β‐cells, we further discuss the possibility of targeting specific β‐cell mitochondrial channels for the treatment of Type 2 diabetes, and we finally highlight the evidence from clinical studies. LINKED ARTICLES This article is part of a themed issue on Cellular metabolism and diseases. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v178.10/issuetoc
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Affiliation(s)
| | - Silvia Fernandez-Martinez
- Division of Clinical Pharmacology and Toxicology, Centre de Recherche Clinique, HUG, Genève, Switzerland
| | - Sergio de la Fuente
- Center for Translational Medicine, Department of Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania
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82
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Natarajan V, Chawla R, Mah T, Vivekanandan R, Tan SY, Sato PY, Mallilankaraman K. Mitochondrial Dysfunction in Age-Related Metabolic Disorders. Proteomics 2020; 20:e1800404. [PMID: 32131138 DOI: 10.1002/pmic.201800404] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2019] [Revised: 02/07/2020] [Indexed: 12/16/2022]
Abstract
Aging is a natural biological process in living organisms characterized by receding bioenergetics. Mitochondria are crucial for cellular bioenergetics and thus an important contributor to age-related energetics deterioration. In addition, mitochondria play a major role in calcium signaling, redox homeostasis, and thermogenesis making this organelle a major cellular component that dictates the fate of a cell. To maintain its quantity and quality, mitochondria undergo multiple processes such as fission, fusion, and mitophagy to eliminate or replace damaged mitochondria. While this bioenergetics machinery is properly protected, the functional decline associated with age and age-related metabolic diseases is mostly a result of failure in such protective mechanisms. In addition, metabolic by-products like reactive oxygen species also aid in this destructive pathway. Mitochondrial dysfunction has always been thought to be associated with diseases. Moreover, studies in recent years have pointed out that aging contributes to the decay of mitochondrial health by promoting imbalances in key mitochondrial-regulated pathways. Hence, it is crucial to understand the nexus of mitochondrial dysfunction in age-related diseases. This review focuses on various aspects of basic mitochondrial biology and its status in aging and age-related metabolic diseases.
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Affiliation(s)
- Venkateswaran Natarajan
- Mitochondrial Physiology and Metabolism Lab, Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117593, Singapore
| | - Ritu Chawla
- Mitochondrial Physiology and Metabolism Lab, Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117593, Singapore
| | - Tania Mah
- Mitochondrial Physiology and Metabolism Lab, Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117593, Singapore
| | - Rajesh Vivekanandan
- Mitochondrial Physiology and Metabolism Lab, Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117593, Singapore
| | - Shu Yi Tan
- Mitochondrial Physiology and Metabolism Lab, Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117593, Singapore
| | - Priscila Y Sato
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, 19102-1902, USA
| | - Karthik Mallilankaraman
- Mitochondrial Physiology and Metabolism Lab, Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117593, Singapore.,Center for Healthy Longevity, National University Health System, Singapore, 119228, Singapore
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83
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Lambert JP, Murray EK, Elrod JW. MCUB and mitochondrial calcium uptake - modeling, function, and therapeutic potential. Expert Opin Ther Targets 2020; 24:163-169. [PMID: 32093523 PMCID: PMC7078044 DOI: 10.1080/14728222.2020.1732926] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Accepted: 02/18/2020] [Indexed: 01/06/2023]
Affiliation(s)
| | - Emma K Murray
- Center for Translational Medicine, Temple University School of Medicine, Philadelphia, PA, USA
| | - John W Elrod
- Center for Translational Medicine, Temple University School of Medicine, Philadelphia, PA, USA
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84
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Targeting Mitochondrial Calcium Uptake with the Natural Flavonol Kaempferol, to Promote Metabolism/Secretion Coupling in Pancreatic β-cells. Nutrients 2020; 12:nu12020538. [PMID: 32093050 PMCID: PMC7071504 DOI: 10.3390/nu12020538] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Accepted: 02/14/2020] [Indexed: 12/26/2022] Open
Abstract
Pancreatic β-cells secrete insulin to lower blood glucose, following a meal. Maintenance of β-cell function is essential to preventing type 2 diabetes. In pancreatic β-cells, mitochondrial matrix calcium is an activating signal for insulin secretion. Recently, the molecular identity of the mitochondrial calcium uniporter (MCU), the transporter that mediates mitochondrial calcium uptake, was revealed. Its role in pancreatic β-cell signal transduction modulation was clarified, opening new perspectives for intervention. Here, we investigated the effects of a mitochondrial Ca2+-targeted nutritional intervention strategy on metabolism/secretion coupling, in a model of pancreatic insulin-secreting cells (INS-1E). Acute treatment of INS-1E cells with the natural plant flavonoid and MCU activator kaempferol, at a low micromolar range, increased mitochondrial calcium rise during glucose stimulation, without affecting the expression level of the MCU and with no cytotoxicity. Enhanced mitochondrial calcium rises potentiated glucose-induced insulin secretion. Conversely, the MCU inhibitor mitoxantrone inhibited mitochondrial Ca2+ uptake and prevented both glucose-induced insulin secretion and kaempferol-potentiated effects. The kaempferol-dependent potentiation of insulin secretion was finally validated in a model of a standardized pancreatic human islet. We conclude that the plant product kaempferol activates metabolism/secretion coupling in insulin-secreting cells by modulating mitochondrial calcium uptake.
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85
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Chen X, Wu G, Zhang Z, Ma X, Liu L. Neurotoxicity of Mn 3O 4 nanoparticles: Apoptosis and dopaminergic neurons damage pathway. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2020; 188:109909. [PMID: 31740235 DOI: 10.1016/j.ecoenv.2019.109909] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Revised: 10/27/2019] [Accepted: 11/01/2019] [Indexed: 06/10/2023]
Abstract
Mn3O4 nanoparticles (NPs) are used increasingly in various fields due to their excellent physiochemical properties. Previous studies have documented that Mn-based nanomaterials resulted in excess reactive oxygen species (ROS) generation and dopamine (DA) reduction both in vivo and in vitro experiments. However, little is known about the mechanism of ROS production and DA decrease induced by Mn-based nanomaterials. The present study was carried out to elucidate the mechanism of the co-incubation model of dopaminergic neuron PC12 cells and the synthesized Mn3O4 NPs. The results demonstrated that exposure to Mn3O4 NPs reduced cell viability, increased level of lactate dehydrogenase (LDH), triggered oxidative stress and induced apoptosis. Notably, the level of ROS was remarkably increased (>10-fold) with Mn3O4 NPs exposure. We also found that mitochondrial calcium Ca2+ uniporter (MCU) was up-regulated and the mitochondrial Ca2+ concentration ([Ca2+]mito) increased induced by Mn3O4 NPs in PC12 cells. Furthermore, the MCU inhibitor RuR significantly attenuated Mn3O4 NPs-induced [Ca2+]mito, ROS production and apoptosis. In PC12 cells, the decrease of DA content was mainly due to the downregulation of DOPA decarboxylase (DDC) expression caused by Mn3O4 NPs treatment. The expression of proteins related to DA storage system was not significantly affected by treatment.
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Affiliation(s)
- Xue Chen
- Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin, 300071, China
| | - Guizhu Wu
- Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin, 300071, China
| | - Ze Zhang
- Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin, 300071, China
| | - Xiaoyong Ma
- Shanxi Provincial Research Academy of Environmental Science, Xinghua Street NO.11, Taiyuan, Shanxi, 030027, China.
| | - Lu Liu
- Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin, 300071, China.
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86
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Dubinin MV, Talanov EY, Tenkov KS, Starinets VS, Mikheeva IB, Sharapov MG, Belosludtsev KN. Duchenne muscular dystrophy is associated with the inhibition of calcium uniport in mitochondria and an increased sensitivity of the organelles to the calcium-induced permeability transition. Biochim Biophys Acta Mol Basis Dis 2020; 1866:165674. [PMID: 31926263 DOI: 10.1016/j.bbadis.2020.165674] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Revised: 01/02/2020] [Accepted: 01/06/2020] [Indexed: 12/13/2022]
Abstract
Duchenne muscular dystrophy (DMD) is characterized by a pronounced and progressive degradation of the structure of skeletal muscles, which decreases their strength and lowers endurance of the organism. At muscular dystrophy, mitochondria are known to undergo significant functional changes, which is manifested in a decreased efficiency of oxidative phosphorylation and impaired energy metabolism of the cell. It is believed that the DMD-induced functional changes of mitochondria are mainly associated with the dysregulation of Ca2+ homeostasis. This work examines the kinetic parameters of Ca2+ transport and the opening of the Ca2+-dependent MPT pore in the skeletal-muscle mitochondria of the dystrophin-deficient C57BL/10ScSn-mdx mice. As compared to the organelles of wild-type animals, skeletal-muscle mitochondria of mdx mice have been found to be much less efficient in respect to Ca2+ uniport, with the kinetics of Na+-dependent Ca2+ efflux not changing. The data obtained indicate that the decreased rate of Ca2+ uniport in the mitochondria of mdx mice may be associated with the increased level of the dominant negative subunit of Ca2+ uniporter (MCUb). The experiments have also shown that in mdx mice, skeletal-muscle mitochondria have low resistance to the induction of MPT, which may be related to a significantly increased expression of adenylate translocator (ANT2), a possible structural element of the MPT pore. The paper discusses how changes in the expression of calcium uniporter and putative components of the MPT pore caused by the development of DMD can affect Ca2+ homeostasis of skeletal-muscle mitochondria.
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Affiliation(s)
- Mikhail V Dubinin
- Mari State University, pl. Lenina 1, Yoshkar-Ola, Mari El 424001, Russia.
| | - Eugeny Yu Talanov
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Institutskaya 3, Pushchino, Moscow Region 142290, Russia
| | - Kirill S Tenkov
- Mari State University, pl. Lenina 1, Yoshkar-Ola, Mari El 424001, Russia
| | - Vlada S Starinets
- Mari State University, pl. Lenina 1, Yoshkar-Ola, Mari El 424001, Russia
| | - Irina B Mikheeva
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Institutskaya 3, Pushchino, Moscow Region 142290, Russia
| | - Mars G Sharapov
- Institute of Cell Biophysics, Russian Academy of Sciences, PSCBR RAS, Institutskaya 3, Pushchino, Moscow Region 142290, Russia
| | - Konstantin N Belosludtsev
- Mari State University, pl. Lenina 1, Yoshkar-Ola, Mari El 424001, Russia; Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Institutskaya 3, Pushchino, Moscow Region 142290, Russia
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87
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Ashrafi G, de Juan-Sanz J, Farrell RJ, Ryan TA. Molecular Tuning of the Axonal Mitochondrial Ca 2+ Uniporter Ensures Metabolic Flexibility of Neurotransmission. Neuron 2019; 105:678-687.e5. [PMID: 31862210 DOI: 10.1016/j.neuron.2019.11.020] [Citation(s) in RCA: 133] [Impact Index Per Article: 26.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 10/16/2019] [Accepted: 11/12/2019] [Indexed: 01/08/2023]
Abstract
The brain is a vulnerable metabolic organ and must adapt to different fuel conditions to sustain function. Nerve terminals are a locus of this vulnerability, but how they regulate ATP synthesis as fuel conditions vary is unknown. We show that synapses can switch from glycolytic to oxidative metabolism, but to do so, they rely on activity-driven presynaptic mitochondrial Ca2+ uptake to accelerate ATP production. We demonstrate that, whereas mitochondrial Ca2+ uptake requires elevated extramitochondrial Ca2+ in non-neuronal cells, axonal mitochondria readily take up Ca2+ in response to small changes in external Ca2+. We identified the brain-specific protein MICU3 as a critical driver of this tuning of Ca2+ sensitivity. Ablation of MICU3 renders axonal mitochondria similar to non-neuronal mitochondria, prevents acceleration of local ATP synthesis, and impairs presynaptic function under oxidative conditions. Thus, presynaptic mitochondria rely on MICU3 to facilitate mitochondrial Ca2+ uptake during activity and achieve metabolic flexibility.
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Affiliation(s)
- Ghazaleh Ashrafi
- Department of Biochemistry, Weill Cornell Medicine, New York, NY 10065, USA
| | - Jaime de Juan-Sanz
- Department of Biochemistry, Weill Cornell Medicine, New York, NY 10065, USA
| | - Ryan J Farrell
- Department of Biochemistry, Weill Cornell Medicine, New York, NY 10065, USA; David Rockefeller Graduate Program, Rockefeller University, New York, NY 10065, USA
| | - Timothy A Ryan
- Department of Biochemistry, Weill Cornell Medicine, New York, NY 10065, USA.
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88
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Mitochondrial morphology provides a mechanism for energy buffering at synapses. Sci Rep 2019; 9:18306. [PMID: 31797946 PMCID: PMC6893035 DOI: 10.1038/s41598-019-54159-1] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Accepted: 10/24/2019] [Indexed: 01/27/2023] Open
Abstract
Mitochondria as the main energy suppliers of eukaryotic cells are highly dynamic organelles that fuse, divide and are transported along the cytoskeleton to ensure cellular energy homeostasis. While these processes are well established, substantial evidence indicates that the internal structure is also highly variable in dependence on metabolic conditions. However, a quantitative mechanistic understanding of how mitochondrial morphology affects energetic states is still elusive. To address this question, we here present an agent-based multiscale model that integrates three-dimensional morphologies from electron microscopy tomography with the molecular dynamics of the main ATP producing components. We apply our modeling approach to mitochondria at the synapse which is the largest energy consumer within the brain. Interestingly, comparing the spatiotemporal simulations with a corresponding space-independent approach, we find minor spatial effects when the system relaxes toward equilibrium but a qualitative difference in fluctuating environments. These results suggest that internal mitochondrial morphology is not only optimized for ATP production but also provides a mechanism for energy buffering and may represent a mechanism for cellular robustness.
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89
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Boyman L, Karbowski M, Lederer WJ. Regulation of Mitochondrial ATP Production: Ca 2+ Signaling and Quality Control. Trends Mol Med 2019; 26:21-39. [PMID: 31767352 DOI: 10.1016/j.molmed.2019.10.007] [Citation(s) in RCA: 131] [Impact Index Per Article: 26.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Revised: 10/16/2019] [Accepted: 10/23/2019] [Indexed: 02/06/2023]
Abstract
Cardiac ATP production primarily depends on oxidative phosphorylation in mitochondria and is dynamically regulated by Ca2+ levels in the mitochondrial matrix as well as by cytosolic ADP. We discuss mitochondrial Ca2+ signaling and its dysfunction which has recently been linked to cardiac pathologies including arrhythmia and heart failure. Similar dysfunction in other excitable and long-lived cells including neurons is associated with neurodegenerative diseases such as Alzheimer's disease (AD), amyotrophic lateral sclerosis (ALS), and Parkinson's disease (PD). Central to this new understanding is crucial Ca2+ regulation of both mitochondrial quality control and ATP production. Mitochondria-associated membrane (MAM) signaling from the sarcoplasmic reticulum (SR) and the endoplasmic reticulum (ER) to mitochondria is discussed. We propose future research directions that emphasize a need to define quantitatively the physiological roles of MAMs, as well as mitochondrial quality control and ATP production.
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Affiliation(s)
- Liron Boyman
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD 21201, USA; Department of Physiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Mariusz Karbowski
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD 21201, USA; Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - W Jonathan Lederer
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD 21201, USA; Department of Physiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
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90
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Vicente M, Salgado-Almario J, Soriano J, Burgos M, Domingo B, Llopis J. Visualization of Mitochondrial Ca 2+ Signals in Skeletal Muscle of Zebrafish Embryos with Bioluminescent Indicators. Int J Mol Sci 2019; 20:ijms20215409. [PMID: 31671636 PMCID: PMC6862566 DOI: 10.3390/ijms20215409] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 10/25/2019] [Accepted: 10/28/2019] [Indexed: 01/16/2023] Open
Abstract
Mitochondria are believed to play an important role in shaping the intracellular Ca2+ transients during skeletal muscle contraction. There is discussion about whether mitochondrial matrix Ca2+ dynamics always mirror the cytoplasmic changes and whether this happens in vivo in whole organisms. In this study, we characterized cytosolic and mitochondrial Ca2+ signals during spontaneous skeletal muscle contractions in zebrafish embryos expressing bioluminescent GFP-aequorin (GA, cytoplasm) and mitoGFP-aequorin (mitoGA, trapped in the mitochondrial matrix). The Ca2+ transients measured with GA and mitoGA reflected contractions of the trunk observed by transmitted light. The mitochondrial uncoupler FCCP and the inhibitor of the mitochondrial calcium uniporter (MCU), DS16570511, abolished mitochondrial Ca2+ transients whereas they increased the frequency of cytosolic Ca2+ transients and muscle contractions, confirming the subcellular localization of mitoGA. Mitochondrial Ca2+ dynamics were also determined with mitoGA and were found to follow closely cytoplasmic changes, with a slower decay. Cytoplasmic Ca2+ kinetics and propagation along the trunk and tail were characterized with GA and with the genetically encoded fluorescent Ca2+ indicator, Twitch-4. Although fluorescence provided a better spatio-temporal resolution, GA was able to resolve the same kinetic parameters while allowing continuous measurements for hours.
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Affiliation(s)
- Manuel Vicente
- Physiology and Cell Dynamics Group, Centro Regional de Investigaciones Biomédicas (CRIB) and Facultad de Medicina de Albacete, Universidad de Castilla-La Mancha, C/Almansa 14, 02006 Albacete, Spain.
| | - Jussep Salgado-Almario
- Physiology and Cell Dynamics Group, Centro Regional de Investigaciones Biomédicas (CRIB) and Facultad de Medicina de Albacete, Universidad de Castilla-La Mancha, C/Almansa 14, 02006 Albacete, Spain.
| | - Joaquim Soriano
- Physiology and Cell Dynamics Group, Centro Regional de Investigaciones Biomédicas (CRIB) and Facultad de Medicina de Albacete, Universidad de Castilla-La Mancha, C/Almansa 14, 02006 Albacete, Spain.
| | - Miguel Burgos
- Physiology and Cell Dynamics Group, Centro Regional de Investigaciones Biomédicas (CRIB) and Facultad de Medicina de Albacete, Universidad de Castilla-La Mancha, C/Almansa 14, 02006 Albacete, Spain.
| | - Beatriz Domingo
- Physiology and Cell Dynamics Group, Centro Regional de Investigaciones Biomédicas (CRIB) and Facultad de Medicina de Albacete, Universidad de Castilla-La Mancha, C/Almansa 14, 02006 Albacete, Spain.
| | - Juan Llopis
- Physiology and Cell Dynamics Group, Centro Regional de Investigaciones Biomédicas (CRIB) and Facultad de Medicina de Albacete, Universidad de Castilla-La Mancha, C/Almansa 14, 02006 Albacete, Spain.
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91
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Abstract
Regulation of ATP production by mitochondria, critical to multicellular life, is poorly understood. Here we investigate the molecular controls of this process in heart and provide a framework for its Ca2+-dependent regulation. We find that the entry of Ca2+ into the matrix through the mitochondrial calcium uniporter (MCU) in heart has neither an apparent cytosolic Ca2+ threshold nor gating function and guides ATP production by its influence on the inner mitochondrial membrane (IMM) potential, ΔΨm. This regulation occurs by matrix Ca2+-dependent modulation of pyruvate and glutamate dehydrogenase activity and not through any effect of Ca2+ on ATP Synthase or on Electron Transport Chain Complexes II, III or IV. Examining the ΔΨm dependence of ATP production over the range of -60 mV to -170 mV in detail reveals that cardiac ATP synthase has a voltage dependence that distinguishes it fundamentally from the previous standard, the bacterial ATP synthase. Cardiac ATP synthase operates with a different ΔΨm threshold for ATP production than bacterial ATP synthase and reveals a concave-upwards shape without saturation. Skeletal muscle MCU Ca2+ flux, while also having no apparent cytosolic Ca2+ threshold, is substantially different from the cardiac MCU, yet the ATP synthase voltage dependence in skeletal muscle is identical to that in the heart. These results suggest that while the conduction of cytosolic Ca2+ signals through the MCU appears to be tissue-dependent, as shown by earlier work1, the control of ATP synthase by ΔΨm appears to be broadly consistent among tissues but is clearly different from bacteria.
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Affiliation(s)
- Andrew P Wescott
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD, USA
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Joseph P Y Kao
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD, USA
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - W Jonathan Lederer
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD, USA
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Liron Boyman
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD, USA.
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD, USA.
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92
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Wacquier B, Combettes L, Dupont G. Cytoplasmic and Mitochondrial Calcium Signaling: A Two-Way Relationship. Cold Spring Harb Perspect Biol 2019; 11:cshperspect.a035139. [PMID: 31110132 DOI: 10.1101/cshperspect.a035139] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Intracellular Ca2+ signals are well organized in all cell types, and trigger a variety of vital physiological processes. The temporal and spatial characteristics of cytosolic Ca2+ increases are mainly governed by the fluxes of this ion across the membrane of the endoplasmic/sarcoplasmic reticulum and the plasma membrane. However, various Ca2+ transporters also allow for Ca2+ exchanges between the cytoplasm and mitochondria. Increases in mitochondrial Ca2+ stimulate the production of ATP, which allows the cells to cope with the increased energy demand created by the stimulus. Less widely appreciated is the fact that Ca2+ handling by mitochondria also shapes cytosolic Ca2+ signals. Indeed, the frequency, amplitude, and duration of cytosolic Ca2+ increases can be altered by modifying the rates of Ca2+ transport into, or from, mitochondria. In this review, we focus on the interplay between mitochondria and Ca2+ signaling, highlighting not only the consequences of cytosolic Ca2+ changes on mitochondrial Ca2+, but also how cytosolic Ca2+ dynamics is controlled by modifications of the Ca2+-handling properties and the metabolism of mitochondria.
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Affiliation(s)
- Benjamin Wacquier
- Unit of Theoretical Chronobiology, Faculté des Sciences, Université Libre de Bruxelles (ULB) CP231, B1050 Brussels, Belgium
| | | | - Geneviève Dupont
- Unit of Theoretical Chronobiology, Faculté des Sciences, Université Libre de Bruxelles (ULB) CP231, B1050 Brussels, Belgium
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93
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Tarasova NV, Vishnyakova PA, Logashina YA, Elchaninov AV. Mitochondrial Calcium Uniporter Structure and Function in Different Types of Muscle Tissues in Health and Disease. Int J Mol Sci 2019; 20:ijms20194823. [PMID: 31569359 PMCID: PMC6801532 DOI: 10.3390/ijms20194823] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Revised: 09/12/2019] [Accepted: 09/26/2019] [Indexed: 02/07/2023] Open
Abstract
Calcium ions (Ca2+) influx to mitochondrial matrix is crucial for the life of a cell. Mitochondrial calcium uniporter (mtCU) is a protein complex which consists of the pore-forming subunit (MCU) and several regulatory subunits. MtCU is the main contributor to inward Ca2+ currents through the inner mitochondrial membrane. Extensive investigations of mtCU involvement into normal and pathological molecular pathways started from the moment of discovery of its molecular components. A crucial role of mtCU in the control of these pathways is now recognized in both health and disease. In particular, impairments of mtCU function have been demonstrated for cardiovascular and skeletal muscle-associated pathologies. This review summarizes the current state of knowledge on mtCU structure, regulation, and function in different types of muscle tissues in health and disease.
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Affiliation(s)
- Nadezhda V Tarasova
- Sechenov First Moscow State Medical University, Institute of Molecular Medicine, Trubetskaya str. 8, bld. 2, Moscow 119991, Russia.
| | - Polina A Vishnyakova
- National Medical Research Center for Obstetrics, Gynecology and Perinatology Named after Academician V.I. Kulakov of Ministry of Healthcare of Russian Federation, 4 Oparina Street, Moscow 117997, Russia.
| | - Yulia A Logashina
- Sechenov First Moscow State Medical University, Institute of Molecular Medicine, Trubetskaya str. 8, bld. 2, Moscow 119991, Russia.
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya Street 16/10, Moscow 117997, Russia.
| | - Andrey V Elchaninov
- National Medical Research Center for Obstetrics, Gynecology and Perinatology Named after Academician V.I. Kulakov of Ministry of Healthcare of Russian Federation, 4 Oparina Street, Moscow 117997, Russia.
- Scientific Research Institute of Human Morphology, 3 Tsurupa Street, Moscow 117418, Russia.
- Peoples' Friendship University of Russia, 6 Miklukho-Maklaya Street, Moscow 117198, Russia.
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94
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Abstract
In heart failure, alterations of Na+ and Ca2+ handling, energetic deficit, and oxidative stress in cardiac myocytes are important pathophysiological hallmarks. Mitochondria are central to these processes because they are the main source for ATP, but also reactive oxygen species (ROS), and their function is critically controlled by Ca2+ During physiological variations of workload, mitochondrial Ca2+ uptake is required to match energy supply to demand but also to keep the antioxidative capacity in a reduced state to prevent excessive emission of ROS. Mitochondria take up Ca2+ via the mitochondrial Ca2+ uniporter, which exists in a multiprotein complex whose molecular components were identified only recently. In heart failure, deterioration of cytosolic Ca2+ and Na+ handling hampers mitochondrial Ca2+ uptake and the ensuing Krebs cycle-induced regeneration of the reduced forms of NADH (nicotinamide adenine dinucleotide) and NADPH (nicotinamide adenine dinucleotide phosphate), giving rise to energetic deficit and oxidative stress. ROS emission from mitochondria can trigger further ROS release from neighboring mitochondria termed ROS-induced ROS release, and cross talk between different ROS sources provides a spatially confined cellular network of redox signaling. Although low levels of ROS may serve physiological roles, higher levels interfere with excitation-contraction coupling, induce maladaptive cardiac remodeling through redox-sensitive kinases, and cell death through mitochondrial permeability transition. Targeting the dysregulated interplay between excitation-contraction coupling and mitochondrial energetics may ameliorate the progression of heart failure.
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Affiliation(s)
- Edoardo Bertero
- From the Comprehensive Heart Failure Center, University Clinic Würzburg, Germany
| | - Christoph Maack
- From the Comprehensive Heart Failure Center, University Clinic Würzburg, Germany.
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95
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Fernandez-Sanz C, De la Fuente S, Sheu SS. Mitochondrial Ca 2+ concentrations in live cells: quantification methods and discrepancies. FEBS Lett 2019; 593:1528-1541. [PMID: 31058316 DOI: 10.1002/1873-3468.13427] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 04/29/2019] [Accepted: 05/02/2019] [Indexed: 12/11/2022]
Abstract
Intracellular Ca2+ signaling controls numerous cellular functions. Mitochondria respond to cytosolic Ca2+ changes by adapting mitochondrial functions and, in some cell types, shaping the spatiotemporal properties of the cytosolic Ca2+ signal. Numerous methods have been developed to specifically and quantitatively measure the mitochondrial-free Ca2+ concentrations ([Ca2+ ]m ), but there are still significant discrepancies in the calculated absolute values of [Ca2+ ]m in stimulated live cells. These discrepancies may be due to the distinct properties of the methods used to measure [Ca2+ ]m , the calcium-free/bound ratio, and the cell-type and stimulus-dependent Ca2+ dynamics. Critical processes happening in the mitochondria, such as ATP generation, ROS homeostasis, and mitochondrial permeability transition opening, depend directly on the [Ca2+ ]m values. Thus, precise determination of absolute [Ca2+ ]m values is imperative for understanding Ca2+ signaling. This review summarizes the reported calibrated [Ca2+ ]m values in many cell types and discusses the discrepancies among these values. Areas for future research are also proposed.
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Affiliation(s)
- Celia Fernandez-Sanz
- Center for Translational Medicine, Department of Medicine, Thomas Jefferson University, Philadelphia, PA, USA
| | - Sergio De la Fuente
- Center for Translational Medicine, Department of Medicine, Thomas Jefferson University, Philadelphia, PA, USA
| | - Shey-Shing Sheu
- Center for Translational Medicine, Department of Medicine, Thomas Jefferson University, Philadelphia, PA, USA
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96
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Boyman L, Coleman AK, Zhao G, Wescott AP, Joca HC, Greiser BM, Karbowski M, Ward CW, Lederer WJ. Dynamics of the mitochondrial permeability transition pore: Transient and permanent opening events. Arch Biochem Biophys 2019; 666:31-39. [PMID: 30930285 PMCID: PMC6538282 DOI: 10.1016/j.abb.2019.03.016] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Revised: 03/19/2019] [Accepted: 03/26/2019] [Indexed: 12/11/2022]
Abstract
A gentle optical examination of the mitochondrial permeability transition pore (mPTP) opening events was carried out in isolated quiescent ventricular myocytes by tracking the inner membrane potential (ΔΨM) using TMRM (tetramethylrhodamine methyl ester). Zeiss Airyscan 880 ″super-resolution" or "high-resolution" imaging was done with very low levels of illumination (0.009% laser power). In cellular areas imaged every 9 s (ROI or regions of interest), transient depolarizations of variable amplitudes occurred at increasing rates for the first 30 min. The time to first depolarization events was 8.4 min (±1.1 SEM n = 21 cells). At longer times, essentially permanent and irreversible depolarizations occurred at an increasing fraction of all events. In other cellular areas surrounding the ROI, mitochondria were rarely illuminated (once per 5 min) and virtually no permanent depolarization events occurred for over 1 h of imaging. These findings suggest that photon stress due to the imaging itself plays an important role in the generation of both the transient mPTP opening events as well as the permanent mPTP opening events. Consistent with the evidence that photon "stress" in mitochondria loaded with virtually any photon absorbing substance, generates reactive oxygen species (ROS) [1-5], we show that cyclosporine-A (CsA, 10 μM) and the antioxidant n-acetyl cysteine (NAC, 10 mM), reduced the number of events by 80% and 93% respectively. Furthermore, CsA and NAC treatment led to the virtual disappearance of permanent depolarization events. Nevertheless, all transient depolarization events in any condition (control, CsA and NAC) appeared to repolarize with a similar half-time of 30 ± 6 s (n = 478) at 37 °C. Further experiments showed quantitatively similar results in cerebral vascular smooth muscle cells, using a different confocal system, and different photon absorbing reagent (TMRE; tetramethylrhodamine ethyl ester). In these experiments, using modest power (1% laser power) transient depolarization events were seen in only 8 out of 23 cells while with higher power (8%), all cells showed transient events, which align with the level of photon stress being the driver of the effect. Together, our findings suggest that photon-induced ROS is sufficient to cause depolarization events of individual mitochondria in quiescent cells; without electrical or mechanical activity to stimulates mitochondrial metabolism, and without raising the mitochondrial matrix Ca2+. In a broad context, these findings neither support nor deny the relevance or occurrence of ΔΨM depolarization events in specific putatively physiologic mitochondrial behaviors such as MitoFlashes [6,7] or MitoWinks [8]. Instead, our findings raise a caution with regards to the physiological and pathophysiological functions attributed to singular ΔΨM depolarization events when those functions are investigated using photon absorbing substances. Nevertheless, using photon stress as a tool ("Optical Stress-Probe"), we can extract information on the activation, reversibility, permanency and kinetics of mitochondrial depolarization. These data may provide new information on mPTP, help identify the mPTP protein complex, and establish the physiological function of the mPTP protein complex and their links to MitoFlashes and MitoWinks.
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Affiliation(s)
- Liron Boyman
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, 111 Penn Street, Baltimore, MD, 21201, USA; Department of Physiology, University of Maryland School of Medicine, 111 Penn Street, Baltimore, MD, 21201, USA.
| | - Andrew K Coleman
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, 111 Penn Street, Baltimore, MD, 21201, USA; Department of Physiology, University of Maryland School of Medicine, 111 Penn Street, Baltimore, MD, 21201, USA
| | - Guiling Zhao
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, 111 Penn Street, Baltimore, MD, 21201, USA; Department of Physiology, University of Maryland School of Medicine, 111 Penn Street, Baltimore, MD, 21201, USA
| | - Andrew P Wescott
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, 111 Penn Street, Baltimore, MD, 21201, USA; Department of Physiology, University of Maryland School of Medicine, 111 Penn Street, Baltimore, MD, 21201, USA
| | - Humberto C Joca
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, 111 Penn Street, Baltimore, MD, 21201, USA; Department of Physiology, University of Maryland School of Medicine, 111 Penn Street, Baltimore, MD, 21201, USA
| | - B Maura Greiser
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, 111 Penn Street, Baltimore, MD, 21201, USA; Department of Physiology, University of Maryland School of Medicine, 111 Penn Street, Baltimore, MD, 21201, USA
| | - Mariusz Karbowski
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, 111 Penn Street, Baltimore, MD, 21201, USA; Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, 111 Penn Street, Baltimore, MD, 21201, USA
| | - Chris W Ward
- Department of Orthopedics, University of Maryland School of Medicine, Baltimore, MD, USA
| | - W J Lederer
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, 111 Penn Street, Baltimore, MD, 21201, USA; Department of Physiology, University of Maryland School of Medicine, 111 Penn Street, Baltimore, MD, 21201, USA.
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97
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Zhang Y, Ji X, Ku T, Li B, Li G, Sang N. Ambient fine particulate matter exposure induces cardiac functional injury and metabolite alterations in middle-aged female mice. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2019; 248:121-132. [PMID: 30784831 DOI: 10.1016/j.envpol.2019.01.080] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Revised: 01/17/2019] [Accepted: 01/19/2019] [Indexed: 06/09/2023]
Abstract
Plenty of epidemiological studies have shown that exposure to ambient particulate matter (PM2.5) is linked to cardiovascular diseases (CVDs) in older even in middle-aged populations; however, experimental evidence through intuitive metabolic analysis to confirm the age susceptibility and explain the related molecular mechanism of PM2.5-induced cardiotoxicity is relatively rare. In the present study, C57BL/6 mice (adult (4-month) and middle-aged (10-month)) were given 3 mg/kg PM2.5 every other day by oropharyngeal aspiration for 4 weeks, and then, body and cardiac parameter, containing weight data, cardiac function, ultrastructure, metabolic analysis, and molecular detection were conducted to investigate the PM2.5-induced cardiotoxicity. The results indicated that middle-aged mice were more susceptible to PM2.5, displaying slow cardiac growth, cardiac dysfunction, abnormal mitochondrial structure and function, and cardiac metabolic disorders. The altered metabolites were enriched in carbohydrate metabolism, fatty acid metabolism, amino acid metabolism, nucleotide metabolism and nicotinate and nicotinamide metabolism. In conclusion, we speculated that the cardiac metabolic disorders may be important factors in PM2.5-induced cardiac dysfunction and mitochondrial structure destruction in middle-aged mice, providing a new direction for the study of the association between PM2.5 and CVDs.
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Affiliation(s)
- Yingying Zhang
- College of Environment and Resource, Research Center of Environment and Health, Shanxi University, Taiyuan, Shanxi, 030006, PR China
| | - Xiaotong Ji
- College of Environment and Resource, Research Center of Environment and Health, Shanxi University, Taiyuan, Shanxi, 030006, PR China
| | - Tingting Ku
- College of Environment and Resource, Research Center of Environment and Health, Shanxi University, Taiyuan, Shanxi, 030006, PR China
| | - Ben Li
- College of Environment and Resource, Research Center of Environment and Health, Shanxi University, Taiyuan, Shanxi, 030006, PR China
| | - Guangke Li
- College of Environment and Resource, Research Center of Environment and Health, Shanxi University, Taiyuan, Shanxi, 030006, PR China
| | - Nan Sang
- College of Environment and Resource, Research Center of Environment and Health, Shanxi University, Taiyuan, Shanxi, 030006, PR China.
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98
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Crosstalk between Calcium and ROS in Pathophysiological Conditions. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2019; 2019:9324018. [PMID: 31178978 PMCID: PMC6507098 DOI: 10.1155/2019/9324018] [Citation(s) in RCA: 111] [Impact Index Per Article: 22.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Accepted: 04/01/2019] [Indexed: 12/12/2022]
Abstract
Calcium ions are highly versatile intracellular signals that regulate many cellular processes. The key to achieving this pleiotropic role is the spatiotemporal control of calcium concentration evoked by an extensive molecular repertoire of signalling components. Among these, reactive oxygen species (ROS) signalling, together with calcium signalling, plays a crucial role in controlling several physiopathological events. Although initially considered detrimental by-products of aerobic metabolism, it is now widely accepted that ROS, in subtoxic levels, act as signalling molecules. However, dysfunctions in the mechanisms controlling the physiological ROS concentration affect cellular homeostasis, leading to the pathogenesis of various disorders.
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99
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Cui C, Yang J, Fu L, Wang M, Wang X. Progress in understanding mitochondrial calcium uniporter complex-mediated calcium signalling: A potential target for cancer treatment. Br J Pharmacol 2019; 176:1190-1205. [PMID: 30801705 DOI: 10.1111/bph.14632] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Revised: 01/02/2019] [Accepted: 01/29/2019] [Indexed: 12/15/2022] Open
Abstract
Due to its Ca2+ buffering capacity, the mitochondrion is one of the most important intracellular organelles in regulating Ca2+ dynamic oscillation. Mitochondrial calcium uniporter (MCU) is the primary mediator of Ca2+ influx into mitochondria, manipulating cell energy metabolism, ROS production, and programmed cell death, all of which are critical for carcinogenesis. The understanding of the uniporter complex was significantly boosted by recent groundbreaking discoveries that identified the uniporter pore-forming subunit MCU and its regulatory molecules, including MCU-dominant negative β subunit (MCUb), essential MCU regulator (EMRE), MCU regulator 1 (MCUR1), mitochondrial calcium uptake (MICU) 1, MICU2, and MICU3. These provide the means and molecular platform to investigate MCU complex (uniplex)-mediated impaired Ca2+ signalling in physiology and pathology. This review aims to summarize the progress of the understanding regulatory mechanisms of uniplex, roles of uniplex-mediated Ca2+ signalling in cancer, and potential pharmacological inhibitors of MCU.
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Affiliation(s)
- Chaochu Cui
- Henan Key Laboratory of Medical Tissue Regeneration, College of Basic Medical Sciences, Xinxiang Medical University, Xinxiang, China.,Henan Key Laboratory of Neurorestoratology, The First Affiliated Hospital of Xinxiang Medical University, Xinxiang, China.,State Key Laboratory of Oncology in South China; Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China
| | - Jianbo Yang
- Henan Key Laboratory of Medical Tissue Regeneration, College of Basic Medical Sciences, Xinxiang Medical University, Xinxiang, China
| | - Liwu Fu
- State Key Laboratory of Oncology in South China; Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China
| | - Mingyong Wang
- School of Laboratory Medicine, Xinxiang Medical University, Xinxiang, China
| | - Xianwei Wang
- Henan Key Laboratory of Medical Tissue Regeneration, College of Basic Medical Sciences, Xinxiang Medical University, Xinxiang, China
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100
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Duarte LF, Farías MA, Álvarez DM, Bueno SM, Riedel CA, González PA. Herpes Simplex Virus Type 1 Infection of the Central Nervous System: Insights Into Proposed Interrelationships With Neurodegenerative Disorders. Front Cell Neurosci 2019; 13:46. [PMID: 30863282 PMCID: PMC6399123 DOI: 10.3389/fncel.2019.00046] [Citation(s) in RCA: 83] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Accepted: 01/30/2019] [Indexed: 12/21/2022] Open
Abstract
Herpes simplex virus type 1 (HSV-1) is highly prevalent in humans and can reach the brain without evident clinical symptoms. Once in the central nervous system (CNS), the virus can either reside in a quiescent latent state in this tissue, or eventually actively lead to severe acute necrotizing encephalitis, which is characterized by exacerbated neuroinflammation and prolonged neuroimmune activation producing a life-threatening disease. Although HSV-1 encephalitis can be treated with antivirals that limit virus replication, neurological sequelae are common and the virus will nevertheless remain for life in the neural tissue. Importantly, there is accumulating evidence that suggests that HSV-1 infection of the brain both, in symptomatic and asymptomatic individuals could lead to neuronal damage and eventually, neurodegenerative disorders. Here, we review and discuss acute and chronic infection of particular brain regions by HSV-1 and how this may affect neuron and cognitive functions in the host. We review potential cellular and molecular mechanisms leading to neurodegeneration, such as protein aggregation, dysregulation of autophagy, oxidative cell damage and apoptosis, among others. Furthermore, we discuss the impact of HSV-1 infection on brain inflammation and its potential relationship with neurodegenerative diseases.
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Affiliation(s)
- Luisa F Duarte
- Millennium Institute on Immunology and Immunotherapy, Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Mónica A Farías
- Millennium Institute on Immunology and Immunotherapy, Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Diana M Álvarez
- Millennium Institute on Immunology and Immunotherapy, Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Susan M Bueno
- Millennium Institute on Immunology and Immunotherapy, Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Claudia A Riedel
- Millennium Institute on Immunology and Immunotherapy, Departamento de Biología Celular, Facultad de Ciencias de la Vida, Universidad Andrés Bello, Santiago, Chile
| | - Pablo A González
- Millennium Institute on Immunology and Immunotherapy, Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
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