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Stevens TL, Cohen HM, Garbincius JF, Elrod JW. Mitochondrial calcium uniporter channel gatekeeping in cardiovascular disease. NATURE CARDIOVASCULAR RESEARCH 2024; 3:500-514. [PMID: 39185387 PMCID: PMC11343476 DOI: 10.1038/s44161-024-00463-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Accepted: 03/18/2024] [Indexed: 08/27/2024]
Abstract
The mitochondrial calcium (mCa2+) uniporter channel (mtCU) resides at the inner mitochondrial membrane and is required for Ca2+ to enter the mitochondrial matrix. The mtCU is essential for cellular function, as mCa2+ regulates metabolism, bioenergetics, signaling pathways and cell death. mCa2+ uptake is primarily regulated by the MICU family (MICU1, MICU2, MICU3), EF-hand-containing Ca2+-sensing proteins, which respond to cytosolic Ca2+ concentrations to modulate mtCU activity. Considering that mitochondrial function and Ca2+ signaling are ubiquitously disrupted in cardiovascular disease, mtCU function has been a hot area of investigation for the last decade. Here we provide an in-depth review of MICU-mediated regulation of mtCU structure and function, as well as potential mtCU-independent functions of these proteins. We detail their role in cardiac physiology and cardiovascular disease by highlighting the phenotypes of different mutant animal models, with an emphasis on therapeutic potential and targets of interest in this pathway.
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Affiliation(s)
- Tyler L. Stevens
- Aging + Cardiovascular Discovery Center, Department of Cardiovascular Sciences, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, USA
| | - Henry M. Cohen
- Aging + Cardiovascular Discovery Center, Department of Cardiovascular Sciences, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, USA
| | - Joanne F. Garbincius
- Aging + Cardiovascular Discovery Center, Department of Cardiovascular Sciences, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, USA
| | - John W. Elrod
- Aging + Cardiovascular Discovery Center, Department of Cardiovascular Sciences, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, USA
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2
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Roman B, Mastoor Y, Zhang Y, Gross D, Springer D, Liu C, Glancy B, Murphy E. Loss of mitochondrial Ca 2+ uptake protein 3 impairs skeletal muscle calcium handling and exercise capacity. J Physiol 2024; 602:113-128. [PMID: 38018177 PMCID: PMC10824360 DOI: 10.1113/jp284894] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Accepted: 11/06/2023] [Indexed: 11/30/2023] Open
Abstract
Mitochondrial calcium concentration ([Ca2+ ]m ) plays an essential role in bioenergetics, and loss of [Ca2+ ]m homeostasis can trigger diseases and cell death in numerous cell types. Ca2+ uptake into mitochondria occurs via the mitochondrial Ca2+ uniporter (MCU), which is regulated by three mitochondrial Ca2+ uptake (MICU) proteins localized in the intermembrane space, MICU1, 2, and 3. We generated a mouse model of systemic MICU3 ablation and examined its physiological role in skeletal muscle. We found that loss of MICU3 led to impaired exercise capacity. When the muscles were directly stimulated there was a decrease in time to fatigue. MICU3 ablation significantly increased the maximal force of the KO muscle and altered fibre type composition with an increase in the ratio of type IIb (low oxidative capacity) to type IIa (high oxidative capacity) fibres. Furthermore, MICU3-KO mitochondria have reduced uptake of Ca2+ and increased phosphorylation of pyruvate dehydrogenase, indicating that KO animals contain less Ca2+ in their mitochondria. Skeletal muscle from MICU3-KO mice exhibited lower net oxidation of NADH during electrically stimulated muscle contraction compared with wild-type. These data demonstrate that MICU3 plays a role in skeletal muscle physiology by setting the proper threshold for mitochondrial Ca2+ uptake, which is important for matching energy demand and supply in muscle. KEY POINTS: Mitochondrial calcium uptake is an important regulator of bioenergetics and cell death and is regulated by the mitochondrial calcium uniporter (MCU) and three calcium sensitive regulatory proteins (MICU1, 2 and 3). Loss of MICU3 leads to impaired exercise capacity and decreased time to skeletal muscle fatigue. Skeletal muscle from MICU3-KO mice exhibits a net oxidation of NADH during electrically stimulated muscle contractions, suggesting that MICU3 plays a role in skeletal muscle physiology by matching energy demand and supply.
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Affiliation(s)
| | | | - Yingfan Zhang
- Muscle Energetics, NHLBI, and NIAMS, NIH, Bethesda, MD, USA
| | - Dennis Gross
- Cardiac Physiology, NHLBI, NIH, Bethesda, MD, USA
| | | | - Chengyu Liu
- Transgenic Core, NHLBI, NIH, Bethesda, MD, USA
| | - Brian Glancy
- Muscle Energetics, NHLBI, and NIAMS, NIH, Bethesda, MD, USA
- Transgenic Core, NHLBI, NIH, Bethesda, MD, USA
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3
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Al-Mutairy EA, Al Qattan S, Khalid M, Al-Enazi AA, Al-Saif MM, Imtiaz F, Ramzan K, Raveendran V, Alaiya A, Meyer BF, Atamas SP, Collison KS, Khabar KS, Hasday JD, Al-Mohanna F. Wild-type S100A3 and S100A13 restore calcium homeostasis and mitigate mitochondrial dysregulation in pulmonary fibrosis patient-derived cells. Front Cell Dev Biol 2023; 11:1282868. [PMID: 38099297 PMCID: PMC10720433 DOI: 10.3389/fcell.2023.1282868] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Accepted: 11/20/2023] [Indexed: 12/17/2023] Open
Abstract
Patients with digenic S100A3 and S100A13 mutations exhibited an atypical and progressive interstitial pulmonary fibrosis, with impaired intracellular calcium homeostasis and mitochondrial dysfunction. Here we provide direct evidence of a causative effect of the mutation on receptor mediated calcium signaling and calcium store responses in control cells transfected with mutant S100A3 and mutant S100A13. We demonstrate that the mutations lead to increased mitochondrial mass and hyperpolarization, both of which were reversed by transfecting patient-derived cells with the wild type S100A3 and S100A13, or extracellular treatment with the recombinant proteins. In addition, we demonstrate increased secretion of inflammatory mediators in patient-derived cells and in control cells transfected with the mutant-encoding constructs. These findings indicate that treatment of patients' cells with recombinant S100A3 and S100A13 proteins is sufficient to normalize most of cellular responses, and may therefore suggest the use of these recombinant proteins in the treatment of this devastating disease.
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Affiliation(s)
- Eid A. Al-Mutairy
- Department of Cell Biology, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
- Department of Medicine, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Somaya Al Qattan
- Department of Cell Biology, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Mohammed Khalid
- Department of Medicine, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Azizah A. Al-Enazi
- Department of Cell Biology, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Maher M. Al-Saif
- BioMolecular Medicine, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Faiqa Imtiaz
- Clinical Genomics, Center of Genomic Medicine, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Khushnooda Ramzan
- Clinical Genomics, Center of Genomic Medicine, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Vineesh Raveendran
- Department of Cell Biology, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Ayodele Alaiya
- Stem Cell Therapy Program, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Brian F. Meyer
- Clinical Genomics, Center of Genomic Medicine, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Sergei P. Atamas
- University of Maryland School of Medicine, Baltimore, MD, United States
- Baltimore VA Medical Center, Baltimore, MD, United States
| | - Kate S. Collison
- Department of Cell Biology, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Khalid S. Khabar
- BioMolecular Medicine, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Jeffrey D. Hasday
- University of Maryland School of Medicine, Baltimore, MD, United States
- Baltimore VA Medical Center, Baltimore, MD, United States
| | - Futwan Al-Mohanna
- Department of Cell Biology, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
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4
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Novorolsky RJ, Kasheke GDS, Hakim A, Foldvari M, Dorighello GG, Sekler I, Vuligonda V, Sanders ME, Renden RB, Wilson JJ, Robertson GS. Preserving and enhancing mitochondrial function after stroke to protect and repair the neurovascular unit: novel opportunities for nanoparticle-based drug delivery. Front Cell Neurosci 2023; 17:1226630. [PMID: 37484823 PMCID: PMC10360135 DOI: 10.3389/fncel.2023.1226630] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Accepted: 06/22/2023] [Indexed: 07/25/2023] Open
Abstract
The neurovascular unit (NVU) is composed of vascular cells, glia, and neurons that form the basic component of the blood brain barrier. This intricate structure rapidly adjusts cerebral blood flow to match the metabolic needs of brain activity. However, the NVU is exquisitely sensitive to damage and displays limited repair after a stroke. To effectively treat stroke, it is therefore considered crucial to both protect and repair the NVU. Mitochondrial calcium (Ca2+) uptake supports NVU function by buffering Ca2+ and stimulating energy production. However, excessive mitochondrial Ca2+ uptake causes toxic mitochondrial Ca2+ overloading that triggers numerous cell death pathways which destroy the NVU. Mitochondrial damage is one of the earliest pathological events in stroke. Drugs that preserve mitochondrial integrity and function should therefore confer profound NVU protection by blocking the initiation of numerous injury events. We have shown that mitochondrial Ca2+ uptake and efflux in the brain are mediated by the mitochondrial Ca2+ uniporter complex (MCUcx) and sodium/Ca2+/lithium exchanger (NCLX), respectively. Moreover, our recent pharmacological studies have demonstrated that MCUcx inhibition and NCLX activation suppress ischemic and excitotoxic neuronal cell death by blocking mitochondrial Ca2+ overloading. These findings suggest that combining MCUcx inhibition with NCLX activation should markedly protect the NVU. In terms of promoting NVU repair, nuclear hormone receptor activation is a promising approach. Retinoid X receptor (RXR) and thyroid hormone receptor (TR) agonists activate complementary transcriptional programs that stimulate mitochondrial biogenesis, suppress inflammation, and enhance the production of new vascular cells, glia, and neurons. RXR and TR agonism should thus further improve the clinical benefits of MCUcx inhibition and NCLX activation by increasing NVU repair. However, drugs that either inhibit the MCUcx, or stimulate the NCLX, or activate the RXR or TR, suffer from adverse effects caused by undesired actions on healthy tissues. To overcome this problem, we describe the use of nanoparticle drug formulations that preferentially target metabolically compromised and damaged NVUs after an ischemic or hemorrhagic stroke. These nanoparticle-based approaches have the potential to improve clinical safety and efficacy by maximizing drug delivery to diseased NVUs and minimizing drug exposure in healthy brain and peripheral tissues.
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Affiliation(s)
- Robyn J. Novorolsky
- Department of Pharmacology, Faculty of Medicine, Dalhousie University, Halifax, NS, Canada
- Brain Repair Centre, Faculty of Medicine, Dalhousie University, Halifax, NS, Canada
| | - Gracious D. S. Kasheke
- Department of Pharmacology, Faculty of Medicine, Dalhousie University, Halifax, NS, Canada
- Brain Repair Centre, Faculty of Medicine, Dalhousie University, Halifax, NS, Canada
| | - Antoine Hakim
- School of Pharmacy, Faculty of Science, University of Waterloo, Waterloo, ON, Canada
| | - Marianna Foldvari
- School of Pharmacy, Faculty of Science, University of Waterloo, Waterloo, ON, Canada
| | - Gabriel G. Dorighello
- Department of Pharmacology, Faculty of Medicine, Dalhousie University, Halifax, NS, Canada
- Brain Repair Centre, Faculty of Medicine, Dalhousie University, Halifax, NS, Canada
| | - Israel Sekler
- Department of Physiology and Cell Biology, Faculty of Health Sciences, Ben Gurion University, Beersheva, Israel
| | | | | | - Robert B. Renden
- Department of Physiology and Cell Biology, School of Medicine, University of Nevada, Reno, NV, United States
| | - Justin J. Wilson
- Department of Chemistry and Chemical Biology, College of Arts and Sciences, Cornell University, Ithaca, NY, United States
| | - George S. Robertson
- Department of Pharmacology, Faculty of Medicine, Dalhousie University, Halifax, NS, Canada
- Brain Repair Centre, Faculty of Medicine, Dalhousie University, Halifax, NS, Canada
- Department of Psychiatry, Faculty of Medicine, Dalhousie University, Halifax, NS, Canada
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5
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De Mario A, D'Angelo D, Zanotti G, Raffaello A, Mammucari C. The mitochondrial calcium uniporter complex–A play in five acts. Cell Calcium 2023; 112:102720. [PMID: 37001308 DOI: 10.1016/j.ceca.2023.102720] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 03/22/2023] [Accepted: 03/23/2023] [Indexed: 03/30/2023]
Abstract
Mitochondrial Ca2+ (mitCa2+) uptake controls both intraorganellar and cytosolic functions. Within the organelle, [Ca2+] increases regulate the activity of tricarboxylic acid (TCA) cycle enzymes, thus sustaining oxidative metabolism and ATP production. Reactive oxygen species (ROS) are also generated as side products of oxygen consumption. At the same time, mitochondria act as buffers of cytosolic Ca2+ (cytCa2+) increases, thus regulating Ca2+-dependent cellular processes. In pathological conditions, mitCa2+ overload triggers the opening of the mitochondrial permeability transition pore (mPTP) and the release of apoptotic cofactors. MitCa2+ uptake occurs in response of local [Ca2+] increases in sites of proximity between the endoplasmic reticulum (ER) and the mitochondria and is mediated by the mitochondrial Ca2+ uniporter (MCU), a highly selective channel of the inner mitochondrial membrane (IMM). Both channel and regulatory subunits form the MCU complex (MCUC). Cryogenic electron microscopy (Cryo-EM) and crystal structures revealed the correct assembly of MCUC and the function of critical residues for the regulation of Ca2+ conductance.
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Colussi DM, Stathopulos PB. From passage to inhibition: Uncovering the structural and physiological inhibitory mechanisms of MCUb in mitochondrial calcium regulation. FASEB J 2023; 37:e22678. [PMID: 36538269 PMCID: PMC10107711 DOI: 10.1096/fj.202201080r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 10/14/2022] [Accepted: 11/21/2022] [Indexed: 12/24/2022]
Abstract
Mitochondrial calcium (Ca2+ ) regulation is critically implicated in the regulation of bioenergetics and cell fate. Ca2+ , a universal signaling ion, passively diffuses into the mitochondrial intermembrane space (IMS) through voltage-dependent anion channels (VDAC), where uptake into the matrix is tightly regulated across the inner mitochondrial membrane (IMM) by the mitochondrial Ca2+ uniporter complex (mtCU). In recent years, immense progress has been made in identifying and characterizing distinct structural and physiological mechanisms of mtCU component function. One of the main regulatory components of the Ca2+ selective mtCU channel is the mitochondrial Ca2+ uniporter dominant-negative beta subunit (MCUb). The structural mechanisms underlying the inhibitory effect(s) exerted by MCUb are poorly understood, despite high homology to the main mitochondrial Ca2+ uniporter (MCU) channel-forming subunits. In this review, we provide an overview of the structural differences between MCUb and MCU, believed to contribute to the inhibition of mitochondrial Ca2+ uptake. We highlight the possible structural rationale for the absent interaction between MCUb and the mitochondrial Ca2+ uptake 1 (MICU1) gatekeeping subunit and a potential widening of the pore upon integration of MCUb into the channel. We discuss physiological and pathophysiological information known about MCUb, underscoring implications in cardiac function and arrhythmia as a basis for future therapeutic discovery. Finally, we discuss potential post-translational modifications on MCUb as another layer of important regulation.
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Affiliation(s)
- Danielle M Colussi
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada
| | - Peter B Stathopulos
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada
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7
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Alshawaf AJ, Alnassar SA, Al-Mohanna FA. The interplay of intracellular calcium and zinc ions in response to electric field stimulation in primary rat cortical neurons in vitro. Front Cell Neurosci 2023; 17:1118335. [PMID: 37180947 PMCID: PMC10174245 DOI: 10.3389/fncel.2023.1118335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Accepted: 04/10/2023] [Indexed: 05/16/2023] Open
Abstract
Recent pharmacological studies demonstrate a role for zinc (Zn2+) in shaping intracellular calcium (Ca2+) dynamics and vice versa in excitable cells including neurons and cardiomyocytes. Herein, we sought to examine the dynamic of intracellular release of Ca2+ and Zn2+ upon modifying excitability of primary rat cortical neurons using electric field stimulation (EFS) in vitro. We show that exposure to EFS with an intensity of 7.69 V/cm induces transient membrane hyperpolarization together with transient elevations in the cytosolic levels of Ca2+ and Zn2+ ions. The EFS-induced hyperpolarization was inhibited by prior treatment of cells with the K+ channel opener diazoxide. Chemical hyperpolarization had no apparent effect on either Ca2+ or Zn2+. The source of EFS-induced rise in Ca2+ and Zn2+ seemed to be intracellular, and that the dynamic inferred of an interplay between Ca2+ and Zn2+ ions, whereby the removal of extracellular Ca2+ augmented the release of intracellular Ca2+ and Zn2+ and caused a stronger and more sustained hyperpolarization. We demonstrate that Zn2+ is released from intracellular vesicles located in the soma, with major co-localizations in the lysosomes and endoplasmic reticulum. These studies further support the use of EFS as a tool to interrogate the kinetics of intracellular ions in response to changing membrane potential in vitro.
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Affiliation(s)
- Abdullah J. Alshawaf
- Department of Physiological Sciences, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
- Department of Cell Biology, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Sarah A. Alnassar
- Department of Cell Biology, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Futwan A. Al-Mohanna
- Department of Cell Biology, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
- *Correspondence: Futwan A. Al-Mohanna,
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Baker MJ, Crameri JJ, Thorburn DR, Frazier AE, Stojanovski D. Mitochondrial biology and dysfunction in secondary mitochondrial disease. Open Biol 2022; 12:220274. [PMID: 36475414 PMCID: PMC9727669 DOI: 10.1098/rsob.220274] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Mitochondrial diseases are a broad, genetically heterogeneous class of metabolic disorders characterized by deficits in oxidative phosphorylation (OXPHOS). Primary mitochondrial disease (PMD) defines pathologies resulting from mutation of mitochondrial DNA (mtDNA) or nuclear genes affecting either mtDNA expression or the biogenesis and function of the respiratory chain. Secondary mitochondrial disease (SMD) arises due to mutation of nuclear-encoded genes independent of, or indirectly influencing OXPHOS assembly and operation. Despite instances of novel SMD increasing year-on-year, PMD is much more widely discussed in the literature. Indeed, since the implementation of next generation sequencing (NGS) techniques in 2010, many novel mitochondrial disease genes have been identified, approximately half of which are linked to SMD. This review will consolidate existing knowledge of SMDs and outline discrete categories within which to better understand the diversity of SMD phenotypes. By providing context to the biochemical and molecular pathways perturbed in SMD, we hope to further demonstrate the intricacies of SMD pathologies outside of their indirect contribution to mitochondrial energy generation.
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Affiliation(s)
- Megan J. Baker
- Department of Biochemistry and Pharmacology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Victoria 3052, Australia
| | - Jordan J. Crameri
- Department of Biochemistry and Pharmacology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Victoria 3052, Australia
| | - David R. Thorburn
- Murdoch Children's Research Institute, Royal Children's Hospital and Department of Paediatrics, University of Melbourne, Parkville, Victoria 3052, Australia,Victorian Clinical Genetics Services, Royal Children's Hospital, Parkville, Victoria 3052, Australia
| | - Ann E. Frazier
- Murdoch Children's Research Institute, Royal Children's Hospital and Department of Paediatrics, University of Melbourne, Parkville, Victoria 3052, Australia
| | - Diana Stojanovski
- Department of Biochemistry and Pharmacology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Victoria 3052, Australia
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Wang L, Yang Z, He X, Pu S, Yang C, Wu Q, Zhou Z, Cen X, Zhao H. Mitochondrial protein dysfunction in pathogenesis of neurological diseases. Front Mol Neurosci 2022; 15:974480. [PMID: 36157077 PMCID: PMC9489860 DOI: 10.3389/fnmol.2022.974480] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Accepted: 08/08/2022] [Indexed: 11/21/2022] Open
Abstract
Mitochondria are essential organelles for neuronal function and cell survival. Besides the well-known bioenergetics, additional mitochondrial roles in calcium signaling, lipid biogenesis, regulation of reactive oxygen species, and apoptosis are pivotal in diverse cellular processes. The mitochondrial proteome encompasses about 1,500 proteins encoded by both the nuclear DNA and the maternally inherited mitochondrial DNA. Mutations in the nuclear or mitochondrial genome, or combinations of both, can result in mitochondrial protein deficiencies and mitochondrial malfunction. Therefore, mitochondrial quality control by proteins involved in various surveillance mechanisms is critical for neuronal integrity and viability. Abnormal proteins involved in mitochondrial bioenergetics, dynamics, mitophagy, import machinery, ion channels, and mitochondrial DNA maintenance have been linked to the pathogenesis of a number of neurological diseases. The goal of this review is to give an overview of these pathways and to summarize the interconnections between mitochondrial protein dysfunction and neurological diseases.
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Affiliation(s)
- Liang Wang
- National Chengdu Center for Safety Evaluation of Drugs, State Key Laboratory of Biotherapy/Collaborative Innovation Center for Biotherapy, West China Hospital of Sichuan University, Chengdu, China
| | - Ziyun Yang
- National Chengdu Center for Safety Evaluation of Drugs, State Key Laboratory of Biotherapy/Collaborative Innovation Center for Biotherapy, West China Hospital of Sichuan University, Chengdu, China
- School of Life Sciences, Guangxi Normal University, Guilin, China
- Guangxi Universities, Key Laboratory of Stem Cell and Biopharmaceutical Technology, Guangxi Normal University, Guilin, China
- Research Center for Biomedical Sciences, Guangxi Normal University, Guilin, China
| | - Xiumei He
- School of Life Sciences, Guangxi Normal University, Guilin, China
- Guangxi Universities, Key Laboratory of Stem Cell and Biopharmaceutical Technology, Guangxi Normal University, Guilin, China
- Research Center for Biomedical Sciences, Guangxi Normal University, Guilin, China
| | - Shiming Pu
- School of Life Sciences, Guangxi Normal University, Guilin, China
- Guangxi Universities, Key Laboratory of Stem Cell and Biopharmaceutical Technology, Guangxi Normal University, Guilin, China
- Research Center for Biomedical Sciences, Guangxi Normal University, Guilin, China
| | - Cheng Yang
- School of Life Sciences, Guangxi Normal University, Guilin, China
- Guangxi Universities, Key Laboratory of Stem Cell and Biopharmaceutical Technology, Guangxi Normal University, Guilin, China
- Research Center for Biomedical Sciences, Guangxi Normal University, Guilin, China
| | - Qiong Wu
- School of Life Sciences, Guangxi Normal University, Guilin, China
- Guangxi Universities, Key Laboratory of Stem Cell and Biopharmaceutical Technology, Guangxi Normal University, Guilin, China
- Research Center for Biomedical Sciences, Guangxi Normal University, Guilin, China
| | - Zuping Zhou
- Guangxi Universities, Key Laboratory of Stem Cell and Biopharmaceutical Technology, Guangxi Normal University, Guilin, China
- Research Center for Biomedical Sciences, Guangxi Normal University, Guilin, China
| | - Xiaobo Cen
- National Chengdu Center for Safety Evaluation of Drugs, State Key Laboratory of Biotherapy/Collaborative Innovation Center for Biotherapy, West China Hospital of Sichuan University, Chengdu, China
| | - Hongxia Zhao
- School of Life Sciences, Guangxi Normal University, Guilin, China
- Guangxi Universities, Key Laboratory of Stem Cell and Biopharmaceutical Technology, Guangxi Normal University, Guilin, China
- Research Center for Biomedical Sciences, Guangxi Normal University, Guilin, China
- Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
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10
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Pourtavakoli A, Ghafouri-Fard S. Calcium signaling in neurodevelopment and pathophysiology of autism spectrum disorders. Mol Biol Rep 2022; 49:10811-10823. [PMID: 35857176 DOI: 10.1007/s11033-022-07775-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 07/05/2022] [Indexed: 11/24/2022]
Abstract
BACKGROUND Autism spectrum disorder (ASD) covers a group of neurodevelopmental disorders with complex genetic background. Several genetic mutations, epigenetic alterations, copy number variations and single nucleotide polymorphisms have been reported that cause ASD or modify its phenotype. Among signaling pathways that influence pathogenesis of ASD, calcium signaling has a prominent effect. METHODS We searched PubMed and Google Scholar databases with key words "Calcium signaling" and "Autism spectrum disorder". CONCLUSION This type of signaling has essential roles in the cell physiology. Endoplasmic reticulum and mitochondria are the key organelles involved in this signaling. It is vastly accepted that organellar disorders intensely influence the central nervous system (CNS). Several lines of evidence indicate alterations in the function of calcium channels in polygenic disorders affecting CNS. In the current review, we describe the role of calcium signaling in normal function of CNS and pathophysiology of ASD.
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Affiliation(s)
- Ashkan Pourtavakoli
- Department of Medical Genetics, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Soudeh Ghafouri-Fard
- Department of Medical Genetics, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
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11
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Allen JG, Tessem JS. Ca 2+ Sensors Assemble: Function of the MCU Complex in the Pancreatic Beta Cell. Cells 2022; 11:cells11131993. [PMID: 35805078 PMCID: PMC9265474 DOI: 10.3390/cells11131993] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Revised: 06/17/2022] [Accepted: 06/20/2022] [Indexed: 12/05/2022] Open
Abstract
The Mitochondrial Calcium Uniporter Complex (MCU Complex) is essential for β-cell function due to its role in sustaining insulin secretion. The MCU complex regulates mitochondrial Ca2+ influx, which is necessary for increased ATP production following cellular glucose uptake, keeps the cell membrane K+ channels closed following initial insulin release, and ultimately results in sustained insulin granule exocytosis. Dysfunction in Ca2+ regulation results in an inability to sustain insulin secretion. This review defines the functions, structure, and mutations associated with the MCU complex members mitochondrial calcium uniporter protein (MCU), essential MCU regulator (EMRE), mitochondrial calcium uptake 1 (MICU1), mitochondrial calcium uptake 2 (MICU2), and mitochondrial calcium uptake 3 (MICU3) in the pancreatic β-cell. This review provides a framework for further evaluation of the MCU complex in β-cell function and insulin secretion.
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12
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Rahimi MJ, Urban N, Wegler M, Sticht H, Schaefer M, Popp B, Gaunitz F, Morleo M, Nigro V, Maitz S, Mancini GMS, Ruivenkamp C, Suk EK, Bartolomaeus T, Merkenschlager A, Koboldt D, Bartholomew D, Stegmann APA, Sinnema M, Duynisveld I, Salvarinova R, Race S, de Vries BBA, Trimouille A, Naudion S, Marom D, Hamiel U, Henig N, Demurger F, Rahner N, Bartels E, Hamm JA, Putnam AM, Person R, Abou Jamra R, Oppermann H. De novo variants in ATP2B1 lead to neurodevelopmental delay. Am J Hum Genet 2022; 109:944-952. [PMID: 35358416 DOI: 10.1016/j.ajhg.2022.03.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Accepted: 03/11/2022] [Indexed: 01/01/2023] Open
Abstract
Calcium (Ca2+) is a universal second messenger involved in synaptogenesis and cell survival; consequently, its regulation is important for neurons. ATPase plasma membrane Ca2+ transporting 1 (ATP2B1) belongs to the family of ATP-driven calmodulin-dependent Ca2+ pumps that participate in the regulation of intracellular free Ca2+. Here, we clinically describe a cohort of 12 unrelated individuals with variants in ATP2B1 and an overlapping phenotype of mild to moderate global development delay. Additional common symptoms include autism, seizures, and distal limb abnormalities. Nine probands harbor missense variants, seven of which were in specific functional domains, and three individuals have nonsense variants. 3D structural protein modeling suggested that the variants have a destabilizing effect on the protein. We performed Ca2+ imaging after introducing all nine missense variants in transfected HEK293 cells and showed that all variants lead to a significant decrease in Ca2+ export capacity compared with the wild-type construct, thus proving their pathogenicity. Furthermore, we observed for the same variant set an incorrect intracellular localization of ATP2B1. The genetic findings and the overlapping phenotype of the probands as well as the functional analyses imply that de novo variants in ATP2B1 lead to a monogenic form of neurodevelopmental disorder.
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Affiliation(s)
- Meer Jacob Rahimi
- Institute of Human Genetics, University of Leipzig Hospitals and Clinics, Leipzig 04103, Germany
| | - Nicole Urban
- Rudolf-Boehm-Institute of Pharmacology and Toxicology, University of Leipzig Hospitals and Clinics, Leipzig 04107, Germany
| | - Meret Wegler
- Institute of Human Genetics, University of Leipzig Hospitals and Clinics, Leipzig 04103, Germany
| | - Heinrich Sticht
- Institute of Biochemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen 91054, Germany
| | - Michael Schaefer
- Rudolf-Boehm-Institute of Pharmacology and Toxicology, University of Leipzig Hospitals and Clinics, Leipzig 04107, Germany
| | - Bernt Popp
- Institute of Human Genetics, University of Leipzig Hospitals and Clinics, Leipzig 04103, Germany
| | - Frank Gaunitz
- Department of Neurosurgery, University of Leipzig Hospitals and Clinics, Leipzig 04103, Germany
| | - Manuela Morleo
- Telethon Institute of Genetics and Medicine, Pozzuoli, 80078 Naples, Italy; Department of Precision Medicine, University of Campania "Luigi Vanvitelli," Naples 80138, Italy
| | - Vincenzo Nigro
- Telethon Institute of Genetics and Medicine, Pozzuoli, 80078 Naples, Italy; Department of Precision Medicine, University of Campania "Luigi Vanvitelli," Naples 80138, Italy
| | - Silvia Maitz
- Clinical Pediatric Genetic Unit, Pediatric Clinic, Fondazione MBBM, San Gerardo Hospital, Monza 20900, Italy
| | - Grazia M S Mancini
- ErasmusMC University Medical Center, Department of Clinical Genetics, Rotterdam 3015, the Netherlands
| | - Claudia Ruivenkamp
- Leiden University Medical Center, Clinical Genetics, Leiden 2333, the Netherlands
| | - Eun-Kyung Suk
- Praxis für Humangenetik-Friedrichstrasse, Berlin 10117, Germany
| | - Tobias Bartolomaeus
- Institute of Human Genetics, University of Leipzig Hospitals and Clinics, Leipzig 04103, Germany; CeGaT GmbH and Praxis für Humangenetik Tübingen, Tübingen 72076, Germany
| | - Andreas Merkenschlager
- Department of Neuropediatrics, University of Leipzig Hospitals and Clinics, Leipzig 04103, Germany
| | - Daniel Koboldt
- Institute for Genomic Medicine at Nationwide Children's Hospital, Columbus, OH 43205, USA
| | - Dennis Bartholomew
- Division of Genetic and Genomic Medicine at Nationwide Children's Hospital, Columbus, OH 43205, USA
| | - Alexander P A Stegmann
- Department of Clinical Genetics, Maastricht University Medical Center+, Maastricht 6229, the Netherlands
| | - Margje Sinnema
- Department of Clinical Genetics, Maastricht University Medical Center+, Maastricht 6229, the Netherlands
| | - Irma Duynisveld
- Severinus Institute for Intellectual Disability, 5507 Veldhoven, the Netherlands
| | - Ramona Salvarinova
- Division of Biochemical Genetics, Department of Pediatrics, University of British Columbia, BC Children's Hospital, Vancouver, BC V6H 3N1, Canada
| | - Simone Race
- Division of Biochemical Genetics, Department of Pediatrics, University of British Columbia, BC Children's Hospital, Vancouver, BC V6H 3N1, Canada
| | - Bert B A de Vries
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen 6525, the Netherlands
| | - Aurélien Trimouille
- Service de Pathologie Centre Hospitalier Universitaire de Bordeaux, Bordeaux 33000, France; MRGM, Maladies Rares: Génétique et Métabolisme, INSERM U1211, Université de Bordeaux, Bordeaux 33076, France
| | - Sophie Naudion
- Service de Génétique Médicale, Centre Hospitalier Universitaire de Bordeaux, Bordeaux 33076, France
| | - Daphna Marom
- The Genetics Institute, Tel Aviv Sourasky Medical Center and Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6423906, Israel
| | - Uri Hamiel
- The Genetics Institute, Tel Aviv Sourasky Medical Center and Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6423906, Israel
| | - Noa Henig
- The Genetics Institute, Tel Aviv Sourasky Medical Center and Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6423906, Israel
| | | | - Nils Rahner
- Institute for Clinical Genetics, Bonn 53111, Germany
| | | | - J Austin Hamm
- Pediatric Genetics, East Tennessee Children's Hospital, Knoxville, TN 37916, USA
| | - Abbey M Putnam
- Pediatric Genetics, East Tennessee Children's Hospital, Knoxville, TN 37916, USA
| | - Richard Person
- Clinical Genomics Program, GeneDx, Inc., Gaithersburg, MD 20877, USA
| | - Rami Abou Jamra
- Institute of Human Genetics, University of Leipzig Hospitals and Clinics, Leipzig 04103, Germany
| | - Henry Oppermann
- Institute of Human Genetics, University of Leipzig Hospitals and Clinics, Leipzig 04103, Germany.
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13
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Serna JDC, Amaral AG, Caldeira da Silva CC, Munhoz AC, Vilas-Boas EA, Menezes-Filho SL, Kowaltowski AJ. Regulation of Kidney Mitochondrial Function by Caloric Restriction. Am J Physiol Renal Physiol 2022; 323:F92-F106. [PMID: 35499238 DOI: 10.1152/ajprenal.00461.2021] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Caloric restriction (CR) prevents obesity and increases resilience against pathological stimuli in laboratory rodents. At the mitochondrial level, protection promoted by CR in the brain and liver is related to higher calcium uptake rates and capacities, avoiding Ca2+-induced mitochondrial permeability transition. Dietary restriction has also been shown to increase kidney resistance against damaging stimuli, but if these effects are related to similar mitochondrial adaptations has not been uncovered. Here, we characterized changes in mitochondrial function in response to six months CR in rats, measuring bioenergetic parameters, redox balance and calcium homeostasis. CR promoted an increase in succinate-supported mitochondrial oxygen consumption rates. While CR prevents mitochondrial reactive oxygen species production in many tissues, in kidney we found that mitochondrial H2O2 release was enhanced in a succinate-dependent manner. Surprisingly, and opposite to the effects observed in brain and liver, mitochondria from CR animals are more prone to Ca2+-induced mitochondrial permeability transition, in a manner reversed by antioxidant dithiothreitol. CR mitochondria also displayed higher calcium uptake rates, which were not accompanied by changes in calcium efflux rates, nor related to altered inner mitochondrial membrane potentials or amounts of the mitochondrial calcium uniporter (MCU). Instead, increased mitochondrial calcium uptake rates in CR kidneys correlate with a loss of MICU2, an MCU modulator. Interestingly, MICU2 is also modulated by CR in liver, suggesting it has a broader diet-sensitive regulatory role controlling mitochondrial calcium homeostasis. Together, our results highlight the organ-specific bioenergetic, redox, and ionic transport effects of CR, with some unexpected deleterious effects in kidney.
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Affiliation(s)
- Julian D C Serna
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
| | - Andressa G Amaral
- Departamento de Fisiologia e Biofísica, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, Brazil
| | | | - Ana Cláudia Munhoz
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
| | | | - Sergio L Menezes-Filho
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
| | - Alicia J Kowaltowski
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
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14
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Jackson J, Wischhof L, Scifo E, Pellizzer A, Wang Y, Piazzesi A, Gentile D, Siddig S, Stork M, Hopkins CE, Händler K, Weis J, Roos A, Schultze JL, Nicotera P, Ehninger D, Bano D. SGPL1 stimulates VPS39 recruitment to the mitochondria in MICU1 deficient cells. Mol Metab 2022; 61:101503. [PMID: 35452878 PMCID: PMC9170783 DOI: 10.1016/j.molmet.2022.101503] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 04/08/2022] [Accepted: 04/15/2022] [Indexed: 01/21/2023] Open
Abstract
Objective Mitochondrial “retrograde” signaling may stimulate organelle biogenesis as a compensatory adaptation to aberrant activity of the oxidative phosphorylation (OXPHOS) system. To maintain energy-consuming processes in OXPHOS deficient cells, alternative metabolic pathways are functionally coupled to the degradation, recycling and redistribution of biomolecules across distinct intracellular compartments. While transcriptional regulation of mitochondrial network expansion has been the focus of many studies, the molecular mechanisms promoting mitochondrial maintenance in energy-deprived cells remain poorly investigated. Methods We performed transcriptomics, quantitative proteomics and lifespan assays to identify pathways that are mechanistically linked to mitochondrial network expansion and homeostasis in Caenorhabditis elegans lacking the mitochondrial calcium uptake protein 1 (MICU-1/MICU1). To support our findings, we carried out biochemical and image analyses in mammalian cells and mouse-derived tissues. Results We report that micu-1(null) mutations impair the OXPHOS system and promote C. elegans longevity through a transcriptional program that is independent of the mitochondrial calcium uniporter MCU-1/MCU and the essential MCU regulator EMRE-1/EMRE. We identify sphingosine phosphate lyase SPL-1/SGPL1 and the ATFS-1-target HOPS complex subunit VPS-39/VPS39 as critical lifespan modulators of micu-1(null) mutant animals. Cross-species investigation indicates that SGPL1 upregulation stimulates VPS39 recruitment to the mitochondria, thereby enhancing mitochondria-lysosome contacts. Consistently, VPS39 downregulation compromises mitochondrial network maintenance and basal autophagic flux in MICU1 deficient cells. In mouse-derived muscles, we show that VPS39 recruitment to the mitochondria may represent a common signature associated with altered OXPHOS system. Conclusions Our findings reveal a previously unrecognized SGPL1/VPS39 axis that stimulates intracellular organelle interactions and sustains autophagy and mitochondrial homeostasis in OXPHOS deficient cells. micu-1(null) nematodes are long-lived mitochondrial mutants. MICU-1/MICU1 deficiency stimulates VPS-39/VPS39 and SPL-1/SGPL1 upregulation. VPS-39 sustains mitochondrial network expansion in micu-1(null) nematodes. VPS39 and SGPL1 expression influences mitochondria-lysosome contact sites in MICU1 deficient cells. VPS39/SGPL1 signaling may be a common signature of mitochondrial deficient cells.
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Affiliation(s)
- Joshua Jackson
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Lena Wischhof
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Enzo Scifo
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Anna Pellizzer
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Yiru Wang
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Antonia Piazzesi
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Debora Gentile
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Sana Siddig
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Miriam Stork
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | | | - Kristian Händler
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany; PRECISE Platform for Single Cell Genomics and Epigenomics, German Center for Neurodegenerative Diseases (DZNE), University of Bonn, Bonn, Germany
| | - Joachim Weis
- Institute of Neuropathology, RWTH Aachen University Hospital, Aachen, Germany
| | - Andreas Roos
- Universitätsklinikum Essen and Universität Duisburg-Essen, Essen, Germany
| | - Joachim L Schultze
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany; PRECISE Platform for Single Cell Genomics and Epigenomics, German Center for Neurodegenerative Diseases (DZNE), University of Bonn, Bonn, Germany; LIMES Institute, Department for Genomics and Immunoregulation, University of Bonn, Bonn, Germany
| | | | - Dan Ehninger
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Daniele Bano
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany.
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15
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Garbincius JF, Elrod JW. Mitochondrial calcium exchange in physiology and disease. Physiol Rev 2022; 102:893-992. [PMID: 34698550 PMCID: PMC8816638 DOI: 10.1152/physrev.00041.2020] [Citation(s) in RCA: 136] [Impact Index Per Article: 68.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 08/16/2021] [Accepted: 10/19/2021] [Indexed: 12/13/2022] Open
Abstract
The uptake of calcium into and extrusion of calcium from the mitochondrial matrix is a fundamental biological process that has critical effects on cellular metabolism, signaling, and survival. Disruption of mitochondrial calcium (mCa2+) cycling is implicated in numerous acquired diseases such as heart failure, stroke, neurodegeneration, diabetes, and cancer and is genetically linked to several inherited neuromuscular disorders. Understanding the mechanisms responsible for mCa2+ exchange therefore holds great promise for the treatment of these diseases. The past decade has seen the genetic identification of many of the key proteins that mediate mitochondrial calcium uptake and efflux. Here, we present an overview of the phenomenon of mCa2+ transport and a comprehensive examination of the molecular machinery that mediates calcium flux across the inner mitochondrial membrane: the mitochondrial uniporter complex (consisting of MCU, EMRE, MICU1, MICU2, MICU3, MCUB, and MCUR1), NCLX, LETM1, the mitochondrial ryanodine receptor, and the mitochondrial permeability transition pore. We then consider the physiological implications of mCa2+ flux and evaluate how alterations in mCa2+ homeostasis contribute to human disease. This review concludes by highlighting opportunities and challenges for therapeutic intervention in pathologies characterized by aberrant mCa2+ handling and by summarizing critical unanswered questions regarding the biology of mCa2+ flux.
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Affiliation(s)
- Joanne F Garbincius
- Center for Translational Medicine, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania
| | - John W Elrod
- Center for Translational Medicine, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania
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16
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Dong Z, Yao X. Insight of the role of mitochondrial calcium homeostasis in hepatic insulin resistance. Mitochondrion 2021; 62:128-138. [PMID: 34856389 DOI: 10.1016/j.mito.2021.11.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2021] [Revised: 11/16/2021] [Accepted: 11/24/2021] [Indexed: 12/06/2022]
Abstract
Due to the rapid rise in the prevalence of chronic metabolic disease, more and more clinicians and basic medical researchers focus their eyesight on insulin resistance (IR), an early and central event of metabolic diseases. The occurrence and development of IR are primarily caused by excessive energy intake and reduced energy consumption. Liver is the central organ that controls glucose homeostasis, playing a considerable role in systemic IR. Decreased capacity of oxidative metabolism and mitochondrial dysfunction are being blamed as the direct reason for the development of IR. Mitochondrial Ca2+ plays a fundamental role in maintaining proper mitochondrial function and redox stability. The maintaining of mitochondrial Ca2+ homeostasis requires the cooperation of ion channels in the inner and outer membrane of mitochondria, such as mitochondrial calcium uniporter complex (MCUC) and voltage-dependent anion channels (VDACs). In addition, the crosstalk between the endoplasmic reticulum (ER), lysosome and plasma membrane with mitochondria is also significant for mitochondrial calcium homeostasis, which is responsible for an efficient network of cellular Ca2+ signaling. Here, we review the recent progression in the research about the regulation factors for mitochondrial Ca2+ and how the dysregulation of mitochondrial Ca2+ homeostasis is involved in the pathogenesis of hepatic IR, providing a new perspective for further exploring the role of ion in the onset and development of IR.
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Affiliation(s)
- Zhanchen Dong
- Department of Occupational and Environmental Health, Dalian Medical University, 9 W Lushun South Road, Dalian 116044, PR China
| | - Xiaofeng Yao
- Department of Occupational and Environmental Health, Dalian Medical University, 9 W Lushun South Road, Dalian 116044, PR China.
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17
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Mitochondrial "dysmorphology" in variant classification. Hum Genet 2021; 141:55-64. [PMID: 34750646 DOI: 10.1007/s00439-021-02378-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Accepted: 09/25/2021] [Indexed: 10/19/2022]
Abstract
Mitochondrial disorders are challenging to diagnose. Exome sequencing has greatly enhanced the diagnostic precision of these disorders although interpreting variants of uncertain significance (VUS) remains a formidable obstacle. Whether specific mitochondrial morphological changes can aid in the classification of these variants is unknown. Here, we describe two families (four patients), each with a VUS in a gene known to affect the morphology of mitochondria through a specific role in the fission-fusion balance. In the first, the missense variant in MFF, encoding a fission factor, was associated with impaired fission giving rise to a characteristically over-tubular appearance of mitochondria. In the second, the missense variant in DNAJA3, which has no listed OMIM phenotype, was associated with fragmented appearance of mitochondria consistent with its published deficiency states. In both instances, the highly specific phenotypes allowed us to upgrade the classification of the variants. Our results suggest that, in select cases, mitochondrial "dysmorphology" can be helpful in interpreting variants to reach a molecular diagnosis.
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18
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Structural characterization of the mitochondrial Ca 2+ uniporter provides insights into Ca 2+ uptake and regulation. iScience 2021; 24:102895. [PMID: 34401674 PMCID: PMC8353469 DOI: 10.1016/j.isci.2021.102895] [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] [Indexed: 12/17/2022] Open
Abstract
The mitochondrial uniporter is a Ca2+-selective ion-conducting channel in the inner mitochondrial membrane that is involved in various cellular processes. The components of this uniporter, including the pore-forming membrane subunit MCU and the modulatory subunits MCUb, EMRE, MICU1, and MICU2, have been identified in recent years. Previously, extensive studies revealed various aspects of uniporter activities and proposed multiple regulatory models of mitochondrial Ca2+ uptake. Recently, the individual auxiliary components of the uniporter and its holocomplex have been structurally characterized, providing the first insight into the component structures and their spatial relationship within the context of the uniporter. Here, we review recent uniporter structural studies in an attempt to establish an architectural framework, elucidating the mechanism that governs mitochondrial Ca2+ uptake and regulation, and to address some apparent controversies. This information could facilitate further characterization of mitochondrial Ca2+ permeation and a better understanding of uniporter-related disease conditions. The uniporter contains multiple subunits regulating various cellular processes Significant structural progresses have been made for the holo-complex of uniporter The holo-complex structures have inspired to propose several regulatory models
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19
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Di Marco G, Vallese F, Jourde B, Bergsdorf C, Sturlese M, De Mario A, Techer-Etienne V, Haasen D, Oberhauser B, Schleeger S, Minetti G, Moro S, Rizzuto R, De Stefani D, Fornaro M, Mammucari C. A High-Throughput Screening Identifies MICU1 Targeting Compounds. Cell Rep 2021; 30:2321-2331.e6. [PMID: 32075766 PMCID: PMC7034061 DOI: 10.1016/j.celrep.2020.01.081] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Revised: 01/08/2020] [Accepted: 01/22/2020] [Indexed: 01/01/2023] Open
Abstract
Mitochondrial Ca2+ uptake depends on the mitochondrial calcium uniporter (MCU) complex, a highly selective channel of the inner mitochondrial membrane (IMM). Here, we screen a library of 44,000 non-proprietary compounds for their ability to modulate mitochondrial Ca2+ uptake. Two of them, named MCU-i4 and MCU-i11, are confirmed to reliably decrease mitochondrial Ca2+ influx. Docking simulations reveal that these molecules directly bind a specific cleft in MICU1, a key element of the MCU complex that controls channel gating. Accordingly, in MICU1-silenced or deleted cells, the inhibitory effect of the two compounds is lost. Moreover, MCU-i4 and MCU-i11 fail to inhibit mitochondrial Ca2+ uptake in cells expressing a MICU1 mutated in the critical amino acids that forge the predicted binding cleft. Finally, these compounds are tested ex vivo, revealing a primary role for mitochondrial Ca2+ uptake in muscle growth. Overall, MCU-i4 and MCU-i11 represent leading molecules for the development of MICU1-targeting drugs. An HTS identifies MCU-i4 and MCU-i11 as negative modulators of the MCU MCU-i4 and MCU-i11 bind MICU1 MICU1 is required for the activity of MCU-i4 and MCU-i11 MCU-i4 and MCU-i11 impair muscle cell growth
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Affiliation(s)
- Giulia Di Marco
- Department of Biomedical Sciences, University of Padua, 35131 Padua, Italy
| | - Francesca Vallese
- Department of Biomedical Sciences, University of Padua, 35131 Padua, Italy
| | - Benjamin Jourde
- Novartis Institutes for Biomedical Research, Novartis Campus, 4056 Basel, Switzerland
| | - Christian Bergsdorf
- Novartis Institutes for Biomedical Research, Novartis Campus, 4056 Basel, Switzerland
| | - Mattia Sturlese
- Molecular Modeling Section, Department of Pharmaceutical and Pharmacological Sciences, University of Padua, 35131 Padua, Italy
| | - Agnese De Mario
- Department of Biomedical Sciences, University of Padua, 35131 Padua, Italy
| | | | - Dorothea Haasen
- Novartis Institutes for Biomedical Research, Novartis Campus, 4056 Basel, Switzerland
| | - Berndt Oberhauser
- Novartis Institutes for Biomedical Research, Novartis Campus, 4056 Basel, Switzerland
| | - Simone Schleeger
- Novartis Institutes for Biomedical Research, Novartis Campus, 4056 Basel, Switzerland
| | - Giulia Minetti
- Novartis Institutes for Biomedical Research, Novartis Campus, 4056 Basel, Switzerland
| | - Stefano Moro
- Molecular Modeling Section, Department of Pharmaceutical and Pharmacological Sciences, University of Padua, 35131 Padua, Italy
| | - Rosario Rizzuto
- Department of Biomedical Sciences, University of Padua, 35131 Padua, Italy
| | - Diego De Stefani
- Department of Biomedical Sciences, University of Padua, 35131 Padua, Italy
| | - Mara Fornaro
- Novartis Institutes for Biomedical Research, Novartis Campus, 4056 Basel, Switzerland.
| | - Cristina Mammucari
- Department of Biomedical Sciences, University of Padua, 35131 Padua, Italy.
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20
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A Novel Biomarker Driving Poor-Prognosis Liver Cancer: Overexpression of the Mitochondrial Calcium Gatekeepers. Biomedicines 2020; 8:biomedicines8110451. [PMID: 33114428 PMCID: PMC7693594 DOI: 10.3390/biomedicines8110451] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Revised: 10/22/2020] [Accepted: 10/23/2020] [Indexed: 12/24/2022] Open
Abstract
Several studies have indicated the biological role of mitochondrial Ca2+ uptake in cancer pathophysiology; however, its implications in predicting the prognosis of hepatocellular carcinoma (HCC) are not yet fully understood. Here, we collected tumor specimens and adjacent normal liver tissues from 354 confirmed HCC patients and analyzed the levels of cyclic adenosine monophosphate (cAMP) responsive element binding protein 1 (CREB), mitochondrial calcium uniporter (MCU), mitochondrial calcium uptake 1 and 2 (MICU1, MICU2) using bioinformatics, qRT-PCR, and immunohistochemistry (IHC), and their relationship with clinicopathological characteristics and prognosis. HCC patients with low CREB/MICU1 and high MCU/MICU2 expression exhibited poor survival rate and prognosis in overall survival (OS) and disease-free survival (DFS) analyses. Low CREB/MICU1 and low MICU1 alone indicated poor prognosis in stage I/II and III/IV patients, respectively. In the poor differentiation/undifferentiation group, low expression of MICU1 indicated poor clinical outcomes. Low CREB/MICU1 expression suggested poor outcomes in patients with or without hepatitis B virus (HBV) infection and poor prognosis in the HCV infection group. In the non- hepatitis C virus (HCV) infection group, low MCU1 indicated a poor prognosis. Multivariate analysis demonstrated that CREB and MICU1 expression showed prognostic significance. This study demonstrates the prognostic significance of CREB, MCU, MICU1, and MICU2, in predicting HCC outcomes. Low CREB/MICU1 and high MCU/MICU2 in HCC tissues are associated with poor prognosis, thus offering a novel perspective in the clinical management for HCC patients.
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21
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Zhao J, Zhang S, Chen L, Liu X, Su H, Chen L, Yang L, Zhang H. Sphingosine 1-phosphate protects against radiation-induced ovarian injury in female rats-impact on mitochondrial-related genes. Reprod Biol Endocrinol 2020; 18:99. [PMID: 33046081 PMCID: PMC7549217 DOI: 10.1186/s12958-020-00659-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 10/07/2020] [Indexed: 01/21/2023] Open
Abstract
The toxic effects of ionizing radiation on the gonads have been widely recognized. Sphingosine 1-phosphate (S1P) has a protective effect on ovarian injury, and although it is known that mitochondria are involved in this process, the specific mechanism is not fully understood. The present study analysed the changes in the serum AMH and ovarian histology in Sprague-Dawley female rats exposed to X-ray radiation only or co-administered with S1P. The mRNA expression profile of ovarian tissue was further analysed via next-generation sequencing and bioinformatics approaches to screen out candidate mitochondria-related genes. Finally, differentially expressed target genes were verified by real-time PCR. The results showed that ionizing radiation could reduce the serum AMH level, destroy ovarian structure and decrease the number of follicles in rats, while S1P administration significantly attenuated the impairment of ovarian function. Gene ontology (GO) and KEGG pathway analysis revealed that a variety of genes related to mitochondrial function were differentially expressed, and the protective effect of S1P on mitochondria was more obvious in the acute phase 24 h after radiation. The differentially expressed mitochondrial function-related genes associated with the protective effect of S1P were UQCRH, MICU2 and GPX4, which were subsequently verified by RT-PCR. Therefore, ionizing radiation has a significant effect on ovarian function, and S1P has a protective effect on radiation-induced ovarian injury, in which mitochondria may play an important role. This study sheds new light on the mechanism of radiation-induced ovarian injury and helps develop a novel potential strategy to control it.
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Affiliation(s)
- Jiahui Zhao
- Department of Reproductive Medicine, The Second Affiliated Hospital of Soochow University, NO.1055 SanXiang Road, Suzhou, 215004, Jiangsu Province, China
- Department of Reproductive Medicine, Lianyungang Maternal and Child Health Hospital, NO.669 Qindongmen Road, Lianyungang, 222001, Jiangsu Province, China
| | - Shuyun Zhang
- Department of Reproductive Medicine, The Second Affiliated Hospital of Soochow University, NO.1055 SanXiang Road, Suzhou, 215004, Jiangsu Province, China
| | - Liesong Chen
- Department of Reproductive Medicine, The Second Affiliated Hospital of Soochow University, NO.1055 SanXiang Road, Suzhou, 215004, Jiangsu Province, China
| | - Xiaolong Liu
- Department of Reproductive Medicine, The Second Affiliated Hospital of Soochow University, NO.1055 SanXiang Road, Suzhou, 215004, Jiangsu Province, China
| | - Haihong Su
- Department of Reproductive Medicine, The Second Affiliated Hospital of Soochow University, NO.1055 SanXiang Road, Suzhou, 215004, Jiangsu Province, China
| | - Lili Chen
- Department of Reproductive Medicine, The Second Affiliated Hospital of Soochow University, NO.1055 SanXiang Road, Suzhou, 215004, Jiangsu Province, China
| | - Li Yang
- Department of Reproductive Medicine, The Second Affiliated Hospital of Soochow University, NO.1055 SanXiang Road, Suzhou, 215004, Jiangsu Province, China
| | - Hong Zhang
- Department of Reproductive Medicine, The Second Affiliated Hospital of Soochow University, NO.1055 SanXiang Road, Suzhou, 215004, Jiangsu Province, China.
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22
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Saneto RP. Mitochondrial diseases: expanding the diagnosis in the era of genetic testing. JOURNAL OF TRANSLATIONAL GENETICS AND GENOMICS 2020; 4:384-428. [PMID: 33426505 PMCID: PMC7791531 DOI: 10.20517/jtgg.2020.40] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Mitochondrial diseases are clinically and genetically heterogeneous. These diseases were initially described a little over three decades ago. Limited diagnostic tools created disease descriptions based on clinical, biochemical analytes, neuroimaging, and muscle biopsy findings. This diagnostic mechanism continued to evolve detection of inherited oxidative phosphorylation disorders and expanded discovery of mitochondrial physiology over the next two decades. Limited genetic testing hampered the definitive diagnostic identification and breadth of diseases. Over the last decade, the development and incorporation of massive parallel sequencing has identified approximately 300 genes involved in mitochondrial disease. Gene testing has enlarged our understanding of how genetic defects lead to cellular dysfunction and disease. These findings have expanded the understanding of how mechanisms of mitochondrial physiology can induce dysfunction and disease, but the complete collection of disease-causing gene variants remains incomplete. This article reviews the developments in disease gene discovery and the incorporation of gene findings with mitochondrial physiology. This understanding is critical to the development of targeted therapies.
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Affiliation(s)
- Russell P. Saneto
- Center for Integrative Brain Research, Neuroscience Institute, Seattle, WA 98101, USA
- Department of Neurology/Division of Pediatric Neurology, Seattle Children’s Hospital/University of Washington, Seattle, WA 98105, USA
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23
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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: 58] [Impact Index Per Article: 14.5] [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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24
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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: 40] [Impact Index Per Article: 10.0] [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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25
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Noble M, Lin QT, Sirko C, Houpt JA, Novello MJ, Stathopulos PB. Structural Mechanisms of Store-Operated and Mitochondrial Calcium Regulation: Initiation Points for Drug Discovery. Int J Mol Sci 2020; 21:E3642. [PMID: 32455637 PMCID: PMC7279490 DOI: 10.3390/ijms21103642] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Revised: 05/11/2020] [Accepted: 05/17/2020] [Indexed: 12/18/2022] Open
Abstract
Calcium (Ca2+) is a universal signaling ion that is essential for the life and death processes of all eukaryotes. In humans, numerous cell stimulation pathways lead to the mobilization of sarco/endoplasmic reticulum (S/ER) stored Ca2+, resulting in the propagation of Ca2+ signals through the activation of processes, such as store-operated Ca2+ entry (SOCE). SOCE provides a sustained Ca2+ entry into the cytosol; moreover, the uptake of SOCE-mediated Ca2+ by mitochondria can shape cytosolic Ca2+ signals, function as a feedback signal for the SOCE molecular machinery, and drive numerous mitochondrial processes, including adenosine triphosphate (ATP) production and distinct cell death pathways. In recent years, tremendous progress has been made in identifying the proteins mediating these signaling pathways and elucidating molecular structures, invaluable for understanding the underlying mechanisms of function. Nevertheless, there remains a disconnect between using this accumulating protein structural knowledge and the design of new research tools and therapies. In this review, we provide an overview of the Ca2+ signaling pathways that are involved in mediating S/ER stored Ca2+ release, SOCE, and mitochondrial Ca2+ uptake, as well as pinpoint multiple levels of crosstalk between these pathways. Further, we highlight the significant protein structures elucidated in recent years controlling these Ca2+ signaling pathways. Finally, we describe a simple strategy that aimed at applying the protein structural data to initiating drug design.
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Affiliation(s)
- Megan Noble
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, ON N6A5C1, Canada; (M.N.); (Q.-T.L.); (C.S.); (M.J.N.)
| | - Qi-Tong Lin
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, ON N6A5C1, Canada; (M.N.); (Q.-T.L.); (C.S.); (M.J.N.)
| | - Christian Sirko
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, ON N6A5C1, Canada; (M.N.); (Q.-T.L.); (C.S.); (M.J.N.)
| | - Jacob A. Houpt
- Department of Medicine, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, ON N6A5C1, Canada;
| | - Matthew J. Novello
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, ON N6A5C1, Canada; (M.N.); (Q.-T.L.); (C.S.); (M.J.N.)
| | - Peter B. Stathopulos
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, ON N6A5C1, Canada; (M.N.); (Q.-T.L.); (C.S.); (M.J.N.)
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26
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Tang NH, Kim KW, Xu S, Blazie SM, Yee BA, Yeo GW, Jin Y, Chisholm AD. The mRNA Decay Factor CAR-1/LSM14 Regulates Axon Regeneration via Mitochondrial Calcium Dynamics. Curr Biol 2020; 30:865-876.e7. [PMID: 31983639 DOI: 10.1016/j.cub.2019.12.061] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Revised: 11/26/2019] [Accepted: 12/19/2019] [Indexed: 12/11/2022]
Abstract
mRNA decay factors regulate mRNA turnover by recruiting non-translating mRNAs and targeting them for translational repression and mRNA degradation. How mRNA decay pathways regulate cellular function in vivo with specificity is poorly understood. Here, we show that C. elegans mRNA decay factors, including the translational repressors CAR-1/LSM14 and CGH-1/DDX6, and the decapping enzymes DCAP-1/DCP1, function in neurons to differentially regulate axon development, maintenance, and regrowth following injury. In neuronal cell bodies, CAR-1 fully colocalizes with CGH-1 and partially colocalizes with DCAP-1, suggesting that mRNA decay components form at least two types of cytoplasmic granules. Following axon injury in adult neurons, loss of CAR-1 or CGH-1 results in increased axon regrowth and growth cone formation, whereas loss of DCAP-1 or DCAP-2 results in reduced regrowth. To determine how CAR-1 inhibits regrowth, we analyzed mRNAs bound to pan-neuronally expressed GFP::CAR-1 using a crosslinking and immunoprecipitation-based approach. Among the putative mRNA targets of CAR-1, we characterized the roles of micu-1, a regulator of the mitochondrial calcium uniporter MCU-1, in axon injury. We show that loss of car-1 results increased MICU-1 protein levels, and that enhanced axon regrowth in car-1 mutants is dependent on micu-1 and mcu-1. Moreover, axon injury induces transient calcium influx into axonal mitochondria, dependent on MCU-1. In car-1 loss-of-function mutants and in micu-1 overexpressing animals, the axonal mitochondrial calcium influx is more sustained, which likely underlies enhanced axon regrowth. Our data uncover a novel pathway that controls axon regrowth through axonal mitochondrial calcium uptake.
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Affiliation(s)
- Ngang Heok Tang
- Section of Neurobiology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Kyung Won Kim
- Section of Neurobiology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Suhong Xu
- Section of Neurobiology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Stephen M Blazie
- Section of Neurobiology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Brian A Yee
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Gene W Yeo
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Yishi Jin
- Section of Neurobiology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA; Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Andrew D Chisholm
- Section of Neurobiology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA.
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27
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Abstract
Adult cardiomyocytes are postmitotic cells that undergo very limited cell division. Thus, cardiomyocyte death as occurs during myocardial infarction has very detrimental consequences for the heart. Mitochondria have emerged as an important regulator of cardiovascular health and disease. Mitochondria are well established as bioenergetic hubs for generating ATP but have also been shown to regulate cell death pathways. Indeed many of the same signals used to regulate metabolism and ATP production, such as calcium and reactive oxygen species, are also key regulators of mitochondrial cell death pathways. It is widely hypothesized that an increase in calcium and reactive oxygen species activate a large conductance channel in the inner mitochondrial membrane known as the PTP (permeability transition pore) and that opening of this pore leads to necroptosis, a regulated form of necrotic cell death. Strategies to reduce PTP opening either by inhibition of PTP or inhibiting the rise in mitochondrial calcium or reactive oxygen species that activate PTP have been proposed. A major limitation of inhibiting the PTP is the lack of knowledge about the identity of the protein(s) that form the PTP and how they are activated by calcium and reactive oxygen species. This review will critically evaluate the candidates for the pore-forming unit of the PTP and discuss recent data suggesting that assumption that the PTP is formed by a single molecular identity may need to be reconsidered.
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Affiliation(s)
- Tyler M Bauer
- Laboratory of Cardiac Physiology, National Heart, Lung and Blood Institute, Bethesda, MD
| | - Elizabeth Murphy
- Laboratory of Cardiac Physiology, National Heart, Lung and Blood Institute, Bethesda, MD
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28
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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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29
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Wu W, Shen Q, Lei Z, Qiu Z, Li D, Pei H, Zheng J, Jia Z. The crystal structure of MICU2 provides insight into Ca 2+ binding and MICU1-MICU2 heterodimer formation. EMBO Rep 2019; 20:e47488. [PMID: 31397067 PMCID: PMC6726906 DOI: 10.15252/embr.201847488] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 06/12/2019] [Accepted: 07/12/2019] [Indexed: 11/09/2022] Open
Abstract
The mitochondrial calcium uniporter (MCU) complex mediates the uptake of Ca2+ into mitochondria. Its activity is regulated by a heterodimer of MICU1 and MICU2, two EF-hand-containing proteins that act as the main gatekeeper of the uniporter. Herein we report the crystal structure of human MICU2 at 1.96 Å resolution. Our structure reveals a dimeric architecture of MICU2, in which each monomer adopts the canonical two-lobe structure with a pair of EF-hands in each lobe. Both Ca2+ -bound and Ca2+ -free EF-hands are observed in our structure. Moreover, we characterize the interaction sites within the MICU2 homodimer, as well as the MICU1-MICU2 heterodimer in both Ca2+ -free and Ca2+ -bound conditions. Glu242 in MICU1 and Arg352 in MICU2 are crucial for apo heterodimer formation, while Phe383 in MICU1 and Glu196 in MICU2 significantly contribute to the interaction in the Ca2+ -bound state. Based on our structural and biochemical analyses, we propose a model for MICU1-MICU2 heterodimer formation and its conformational transition from apo to a more compact Ca2+ -bound state, which expands our understanding of this co-regulatory mechanism critical for MCU's mitochondrial calcium uptake function.
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Affiliation(s)
- Wenping Wu
- College of ChemistryBeijing Normal UniversityBeijingChina
| | - Qingya Shen
- College of ChemistryBeijing Normal UniversityBeijingChina
| | - Zhen Lei
- College of ChemistryBeijing Normal UniversityBeijingChina
| | - Zhiyu Qiu
- College of ChemistryBeijing Normal UniversityBeijingChina
| | - Dan Li
- College of ChemistryBeijing Normal UniversityBeijingChina
| | - Hairun Pei
- College of ChemistryBeijing Normal UniversityBeijingChina
| | - Jimin Zheng
- College of ChemistryBeijing Normal UniversityBeijingChina
| | - Zongchao Jia
- Department of Biomedical and Molecular SciencesQueen's UniversityKingstonONCanada
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30
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Al-Mutairy EA, Imtiaz FA, Khalid M, Al Qattan S, Saleh S, Mahmoud LM, Al-Saif MM, Al-Haj L, Al-Enazi A, AlJebreen AM, Mohammed SF, Mobeireek AF, Alkattan K, Chisti MA, Luzina IG, Al-Owain M, Weheba I, Abdelsayed AM, Ramzan K, Janssen LJ, Conca W, Alaiya A, Collison KS, Meyer BF, Atamas SP, Khabar KS, Hasday JD, Al-Mohanna F. An atypical pulmonary fibrosis is associated with co-inheritance of mutations in the calcium binding protein genes S100A3 and S100A13. Eur Respir J 2019; 54:1802041. [PMID: 31073086 PMCID: PMC6637284 DOI: 10.1183/13993003.02041-2018] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Accepted: 04/14/2019] [Indexed: 12/30/2022]
Abstract
BACKGROUND Pulmonary fibrosis is one of the leading indications for lung transplantation. The disease, which is of unknown aetiology, can be progressive, resulting in distortion of the extracellular matrix (ECM), inflammation, fibrosis and eventual death. METHODS 13 patients born to consanguineous parents from two unrelated families presenting with interstitial lung disease were clinically investigated. Nine patients developed respiratory failure and subsequently died. Molecular genetic investigations were performed on patients' whole blood or archived tissues, and cell biological investigations were performed on patient-derived fibroblasts. RESULTS The combination of a unique pattern of early-onset lung fibrosis (at 12-15 years old) with distinctive radiological findings, including 1) traction bronchiectasis, 2) intralobular septal thickening, 3) shrinkage of the secondary pulmonary lobules mainly around the bronchovascular bundles and 4) early type 2 respiratory failure (elevated blood carbon dioxide levels), represents a novel clinical subtype of familial pulmonary fibrosis. Molecular genetic investigation of families revealed a hypomorphic variant in S100A3 and a novel truncating mutation in S100A13, both segregating with the disease in an autosomal recessive manner. Family members that were either heterozygous carriers or wild-type normal for both variants were unaffected. Analysis of patient-derived fibroblasts demonstrated significantly reduced S100A3 and S100A13 expression. Further analysis demonstrated aberrant intracellular calcium homeostasis, mitochondrial dysregulation and differential expression of ECM components. CONCLUSION Our data demonstrate that digenic inheritance of mutations in S100A3 and S100A13 underlie the pathophysiology of pulmonary fibrosis associated with a significant reduction of both proteins, which suggests a calcium-dependent therapeutic approach for management of the disease.
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Affiliation(s)
- Eid A Al-Mutairy
- Dept of Medicine, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
- Dept of Cell Biology, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
- College of Medicine, Al-Faisal University, Riyadh, Saudi Arabia
| | - Faiga Ahmad Imtiaz
- Dept of Genetics, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Mohammed Khalid
- Dept of Medicine, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Somaya Al Qattan
- Dept of Cell Biology, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Soad Saleh
- Dept of Cell Biology, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Linah Mahmood Mahmoud
- BioMolecular Medicine, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Maher Mohammed Al-Saif
- BioMolecular Medicine, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Latifa Al-Haj
- BioMolecular Medicine, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Azizah Al-Enazi
- Dept of Cell Biology, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Abdullah M AlJebreen
- Dept of Radiology, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Shamayel Faheem Mohammed
- Dept of Pathology and Laboratory Medicine, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | | | - Khalid Alkattan
- Dept of Medicine, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
- College of Medicine, Al-Faisal University, Riyadh, Saudi Arabia
| | - Muzamil Amin Chisti
- Dept of Dermatology, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Irina G Luzina
- University of Maryland School of Medicine, Baltimore, MD, USA
- Baltimore VA Medical Center, Baltimore, MD, USA
| | - Mohammed Al-Owain
- College of Medicine, Al-Faisal University, Riyadh, Saudi Arabia
- Dept of Medical Genetics, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Ihab Weheba
- Dept of Medicine, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
- National Research Centre, Cairo, Egypt
| | - Abeer Mohamed Abdelsayed
- Dept of Medicine, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
- Ain Shams University, Cairo, Egypt
| | - Khushnooda Ramzan
- Dept of Genetics, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Luke J Janssen
- St Joseph's Hospital and Dept of Medicine, McMaster University, Hamilton, ON, Canada
| | - Walter Conca
- Dept of Medicine, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
- Dept of Cell Biology, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
- College of Medicine, Al-Faisal University, Riyadh, Saudi Arabia
| | - Ayodele Alaiya
- Stem Cell Therapy Program, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Kate S Collison
- Dept of Cell Biology, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Brian F Meyer
- Dept of Genetics, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Sergei P Atamas
- University of Maryland School of Medicine, Baltimore, MD, USA
- Baltimore VA Medical Center, Baltimore, MD, USA
| | - Khalid S Khabar
- College of Medicine, Al-Faisal University, Riyadh, Saudi Arabia
- BioMolecular Medicine, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Jeffrey D Hasday
- University of Maryland School of Medicine, Baltimore, MD, USA
- Baltimore VA Medical Center, Baltimore, MD, USA
| | - Futwan Al-Mohanna
- Dept of Cell Biology, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
- College of Medicine, Al-Faisal University, Riyadh, Saudi Arabia
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Cao JL, Adaniya SM, Cypress MW, Suzuki Y, Kusakari Y, Jhun BS, O-Uchi J. Role of mitochondrial Ca 2+ homeostasis in cardiac muscles. Arch Biochem Biophys 2019; 663:276-287. [PMID: 30684463 PMCID: PMC6469710 DOI: 10.1016/j.abb.2019.01.027] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Revised: 01/10/2019] [Accepted: 01/22/2019] [Indexed: 12/22/2022]
Abstract
Recent discoveries of the molecular identity of mitochondrial Ca2+ influx/efflux mechanisms have placed mitochondrial Ca2+ transport at center stage in views of cellular regulation in various cell-types/tissues. Indeed, mitochondria in cardiac muscles also possess the molecular components for efficient uptake and extraction of Ca2+. Over the last several years, multiple groups have taken advantage of newly available molecular information about these proteins and applied genetic tools to delineate the precise mechanisms for mitochondrial Ca2+ handling in cardiomyocytes and its contribution to excitation-contraction/metabolism coupling in the heart. Though mitochondrial Ca2+ has been proposed as one of the most crucial secondary messengers in controlling a cardiomyocyte's life and death, the detailed mechanisms of how mitochondrial Ca2+ regulates physiological mitochondrial and cellular functions in cardiac muscles, and how disorders of this mechanism lead to cardiac diseases remain unclear. In this review, we summarize the current controversies and discrepancies regarding cardiac mitochondrial Ca2+ signaling that remain in the field to provide a platform for future discussions and experiments to help close this gap.
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Affiliation(s)
- Jessica L Cao
- Cardiovascular Research Center, Rhode Island Hospital, Providence, RI, USA; Department of Medicine, Division of Cardiology, The Warren Alpert Medical School of Brown University, Providence, RI, USA
| | - Stephanie M Adaniya
- Cardiovascular Research Center, Rhode Island Hospital, Providence, RI, USA; Department of Medicine, Division of Cardiology, The Warren Alpert Medical School of Brown University, Providence, RI, USA; Lillehei Heart Institute, Department of Medicine, Cardiovascular Division, University of Minnesota, Minneapolis, MN, USA
| | - Michael W Cypress
- Lillehei Heart Institute, Department of Medicine, Cardiovascular Division, University of Minnesota, Minneapolis, MN, USA
| | - Yuta Suzuki
- Lillehei Heart Institute, Department of Medicine, Cardiovascular Division, University of Minnesota, Minneapolis, MN, USA
| | - Yoichiro Kusakari
- Department of Cell Physiology, The Jikei University School of Medicine, Minato-ku, Tokyo, Japan
| | - Bong Sook Jhun
- Lillehei Heart Institute, Department of Medicine, Cardiovascular Division, University of Minnesota, Minneapolis, MN, USA
| | - Jin O-Uchi
- Lillehei Heart Institute, Department of Medicine, Cardiovascular Division, University of Minnesota, Minneapolis, MN, USA.
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Phillips CB, Tsai CW, Tsai MF. The conserved aspartate ring of MCU mediates MICU1 binding and regulation in the mitochondrial calcium uniporter complex. eLife 2019; 8:41112. [PMID: 30638448 PMCID: PMC6347451 DOI: 10.7554/elife.41112] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Accepted: 01/07/2019] [Indexed: 01/09/2023] Open
Abstract
The mitochondrial calcium uniporter is a Ca2+ channel that regulates intracellular Ca2+ signaling, oxidative phosphorylation, and apoptosis. It contains the pore-forming MCU protein, which possesses a DIME sequence thought to form a Ca2+ selectivity filter, and also regulatory EMRE, MICU1, and MICU2 subunits. To properly carry out physiological functions, the uniporter must stay closed in resting conditions, becoming open only when stimulated by intracellular Ca2+ signals. This Ca2+-dependent activation, known to be mediated by MICU subunits, is not well understood. Here, we demonstrate that the DIME-aspartate mediates a Ca2+-modulated electrostatic interaction with MICU1, forming an MICU1 contact interface with a nearby Ser residue at the cytoplasmic entrance of the MCU pore. A mutagenesis screen of MICU1 identifies two highly-conserved Arg residues that might contact the DIME-Asp. Perturbing MCU-MICU1 interactions elicits unregulated, constitutive Ca2+ flux into mitochondria. These results indicate that MICU1 confers Ca2+-dependent gating of the uniporter by blocking/unblocking MCU.
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Affiliation(s)
| | - Chen-Wei Tsai
- Department of Biochemistry, Brandeis University, Waltham, United States.,Department of Physiology and Biophysics, University of Colorado Anschutz Medical Campus, Aurora, United States
| | - Ming-Feng Tsai
- Department of Biochemistry, Brandeis University, Waltham, United States.,Department of Physiology and Biophysics, University of Colorado Anschutz Medical Campus, Aurora, United States
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McCormick EM, Zolkipli-Cunningham Z, Falk MJ. Mitochondrial disease genetics update: recent insights into the molecular diagnosis and expanding phenotype of primary mitochondrial disease. Curr Opin Pediatr 2018; 30:714-724. [PMID: 30199403 PMCID: PMC6467265 DOI: 10.1097/mop.0000000000000686] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
PURPOSE OF REVIEW Primary mitochondrial disease (PMD) is a genetically and phenotypically diverse group of inherited energy deficiency disorders caused by impaired mitochondrial oxidative phosphorylation (OXPHOS) capacity. Mutations in more than 350 genes in both mitochondrial and nuclear genomes are now recognized to cause primary mitochondrial disease following every inheritance pattern. Next-generation sequencing technologies have dramatically accelerated mitochondrial disease gene discovery and diagnostic yield. Here, we provide an up-to-date review of recently identified, novel mitochondrial disease genes and/or pathogenic variants that directly impair mitochondrial structure, dynamics, and/or function. RECENT FINDINGS A review of PubMed publications was performed from the past 12 months that identified 16 new PMD genes and/or pathogenic variants, and recognition of expanded phenotypes for a wide variety of mitochondrial disease genes. SUMMARY Broad-based exome sequencing has become the standard first-line diagnostic approach for PMD. This has facilitated more rapid and accurate disease identification, and greatly expanded understanding of the wide spectrum of potential clinical phenotypes. A comprehensive dual-genome sequencing approach to PMD diagnosis continues to improve diagnostic yield, advance understanding of mitochondrial physiology, and provide strong potential to develop precision therapeutics targeted to diverse aspects of mitochondrial disease pathophysiology.
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Affiliation(s)
- Elizabeth M. McCormick
- Mitochondrial Medicine Frontier Program, Division of Human Genetics, Department of Pediatrics, The Children’s Hospital of Philadelphia, PA 19104
| | - Zarazuela Zolkipli-Cunningham
- Mitochondrial Medicine Frontier Program, Division of Human Genetics, Department of Pediatrics, The Children’s Hospital of Philadelphia, PA 19104
| | - Marni J. Falk
- Mitochondrial Medicine Frontier Program, Division of Human Genetics, Department of Pediatrics, The Children’s Hospital of Philadelphia, PA 19104
- Department of Pediatrics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104
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