1
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Gottschalk B, Koshenov Z, Malli R, Graier WF. Implications of mitochondrial membrane potential gradients on signaling and ATP production analyzed by correlative multi-parameter microscopy. Sci Rep 2024; 14:14784. [PMID: 38926476 PMCID: PMC11208492 DOI: 10.1038/s41598-024-65595-z] [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: 02/20/2024] [Accepted: 06/21/2024] [Indexed: 06/28/2024] Open
Abstract
The complex architecture and biochemistry of the inner mitochondrial membrane generate ultra-structures with different phospholipid and protein compositions, shapes, characteristics, and functions. The crista junction (CJ) serves as an important barrier separating the cristae (CM) and inner boundary membranes (IBM). Thereby CJ regulates the movement of ions and ensures distinct electrical potentials across the cristae (ΔΨC) and inner boundary (ΔΨIBM) membranes. We have developed a robust and flexible approach to visualize the CJ permeability with super-resolution microscopy as a readout of local mitochondrial membrane potential (ΔΨmito) fluctuations. This method involves analyzing the distribution of TMRM fluorescence intensity in a model that is restricted to the mitochondrial geometry. We show that mitochondrial Ca2+ elevation hyperpolarizes the CM most likely caused by Ca2+ sensitive increase of mitochondrial tricarboxylic acid cycle (TCA) and subsequent oxidative phosphorylation (OXPHOS) activity in the cristae. Dynamic multi-parameter correlation measurements of spatial mitochondrial membrane potential gradients, ATP levels, and mitochondrial morphometrics revealed a CJ-based membrane potential overflow valve mechanism protecting the mitochondrial integrity during excessive cristae hyperpolarization.
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Affiliation(s)
- Benjamin Gottschalk
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstraße 6/4, 8010, Graz, Austria
| | - Zhanat Koshenov
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstraße 6/4, 8010, Graz, Austria
| | - Roland Malli
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstraße 6/4, 8010, Graz, Austria
- BioTechMed, Graz, Austria
| | - Wolfgang F Graier
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstraße 6/4, 8010, Graz, Austria.
- BioTechMed, Graz, Austria.
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2
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Caron C, Bertolin G. Cristae shaping and dynamics in mitochondrial function. J Cell Sci 2024; 137:jcs260986. [PMID: 38197774 DOI: 10.1242/jcs.260986] [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] [Indexed: 01/11/2024] Open
Abstract
Mitochondria are multifunctional organelles of key importance for cell homeostasis. The outer mitochondrial membrane (OMM) envelops the organelle, and the inner mitochondrial membrane (IMM) is folded into invaginations called cristae. As cristae composition and functions depend on the cell type and stress conditions, they recently started to be considered as a dynamic compartment. A number of proteins are known to play a role in cristae architecture, such as OPA1, MIC60, LETM1, the prohibitin (PHB) complex and the F1FO ATP synthase. Furthermore, phospholipids are involved in the maintenance of cristae ultrastructure and dynamics. The use of new technologies, including super-resolution microscopy to visualize cristae dynamics with superior spatiotemporal resolution, as well as high-content techniques and datasets have not only allowed the identification of new cristae proteins but also helped to explore cristae plasticity. However, a number of open questions remain in the field, such as whether cristae-resident proteins are capable of changing localization within mitochondria, or whether mitochondrial proteins can exit mitochondria through export. In this Review, we present the current view on cristae morphology, stability and composition, and address important outstanding issues that might pave the way to future discoveries.
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Affiliation(s)
- Claire Caron
- Univ. Rennes, CNRS, IGDR (Institute of Genetics and Development of Rennes), UMR 6290, F-35000 Rennes, France
| | - Giulia Bertolin
- Univ. Rennes, CNRS, IGDR (Institute of Genetics and Development of Rennes), UMR 6290, F-35000 Rennes, France
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3
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Underwood EL, Redell JB, Hood KN, Maynard ME, Hylin M, Waxham MN, Zhao J, Moore AN, Dash PK. Enhanced presynaptic mitochondrial energy production is required for memory formation. Sci Rep 2023; 13:14431. [PMID: 37660191 PMCID: PMC10475119 DOI: 10.1038/s41598-023-40877-0] [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: 12/23/2022] [Accepted: 08/17/2023] [Indexed: 09/04/2023] Open
Abstract
Some of the prominent features of long-term memory formation include protein synthesis, gene expression, enhanced neurotransmitter release, increased excitability, and formation of new synapses. As these processes are critically dependent on mitochondrial function, we hypothesized that increased mitochondrial respiration and dynamics would play a prominent role in memory formation. To address this possibility, we measured mitochondrial oxygen consumption (OCR) in hippocampal tissue punches from trained and untrained animals. Our results show that context fear training significantly increased basal, ATP synthesis-linked, and maximal OCR in the Shaffer collateral-CA1 synaptic region, but not in the CA1 cell body layer. These changes were recapitulated in synaptosomes isolated from the hippocampi of fear-trained animals. As dynamin-related protein 1 (Drp1) plays an important role in mitochondrial fission, we examined its role in the increased mitochondrial respiration observed after fear training. Drp1 inhibitors decreased the training-associated enhancement of OCR and impaired contextual fear memory, but did not alter the number of synaptosomes containing mitochondria. Taken together, our results show context fear training increases presynaptic mitochondria respiration, and that Drp-1 mediated enhanced energy production in CA1 pre-synaptic terminals is necessary for context fear memory that does not result from an increase in the number of synaptosomes containing mitochondria or an increase in mitochondrial mass within the synaptic layer.
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Affiliation(s)
- Erica L Underwood
- Department of Neurobiology and Anatomy, The University of Texas McGovern Medical School, P.O. Box 20708, Houston, TX, 77225, USA
| | - John B Redell
- Department of Neurobiology and Anatomy, The University of Texas McGovern Medical School, P.O. Box 20708, Houston, TX, 77225, USA.
| | - Kimberly N Hood
- Department of Neurobiology and Anatomy, The University of Texas McGovern Medical School, P.O. Box 20708, Houston, TX, 77225, USA
| | - Mark E Maynard
- Department of Neurobiology and Anatomy, The University of Texas McGovern Medical School, P.O. Box 20708, Houston, TX, 77225, USA
- Department of Electrical and Computer Engineering, University of Houston, Houston, TX, USA
| | - Michael Hylin
- Department of Neurobiology and Anatomy, The University of Texas McGovern Medical School, P.O. Box 20708, Houston, TX, 77225, USA
- Department of Psychology, Southern Illinois University, Carbondale, IL, USA
| | - M Neal Waxham
- Department of Neurobiology and Anatomy, The University of Texas McGovern Medical School, P.O. Box 20708, Houston, TX, 77225, USA
| | - Jing Zhao
- Department of Neurobiology and Anatomy, The University of Texas McGovern Medical School, P.O. Box 20708, Houston, TX, 77225, USA
| | - Anthony N Moore
- Department of Neurobiology and Anatomy, The University of Texas McGovern Medical School, P.O. Box 20708, Houston, TX, 77225, USA
| | - Pramod K Dash
- Department of Neurobiology and Anatomy, The University of Texas McGovern Medical School, P.O. Box 20708, Houston, TX, 77225, USA
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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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Tomar D, Thomas M, Garbincius JF, Kolmetzky DW, Salik O, Jadiya P, Joseph SK, Carpenter AC, Hajnóczky G, Elrod JW. MICU1 regulates mitochondrial cristae structure and function independently of the mitochondrial Ca 2+ uniporter channel. Sci Signal 2023; 16:eabi8948. [PMID: 37098122 PMCID: PMC10388395 DOI: 10.1126/scisignal.abi8948] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Accepted: 03/30/2023] [Indexed: 04/27/2023]
Abstract
MICU1 is a calcium (Ca2+)-binding protein that regulates the mitochondrial Ca2+ uniporter channel complex (mtCU) and mitochondrial Ca2+ uptake. MICU1 knockout mice display disorganized mitochondrial architecture, a phenotype that is distinct from that of mice with deficiencies in other mtCU subunits and, thus, is likely not explained by changes in mitochondrial matrix Ca2+ content. Using proteomic and cellular imaging techniques, we found that MICU1 localized to the mitochondrial contact site and cristae organizing system (MICOS) and directly interacted with the MICOS components MIC60 and CHCHD2 independently of the mtCU. We demonstrated that MICU1 was essential for MICOS complex formation and that MICU1 ablation resulted in altered cristae organization, mitochondrial ultrastructure, mitochondrial membrane dynamics, and cell death signaling. Together, our results suggest that MICU1 is an intermembrane space Ca2+ sensor that modulates mitochondrial membrane dynamics independently of matrix Ca2+ uptake. This system enables distinct Ca2+ signaling in the mitochondrial matrix and at the intermembrane space to modulate cellular energetics and cell death in a concerted manner.
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Affiliation(s)
- Dhanendra Tomar
- Cardiovascular Research Center, Department of Cardiovascular Sciences, Lewis Katz School of Medicine at Temple University, Philadelphia, PA 19140
| | - Manfred Thomas
- Cardiovascular Research Center, Department of Cardiovascular Sciences, Lewis Katz School of Medicine at Temple University, Philadelphia, PA 19140
| | - Joanne F. Garbincius
- Cardiovascular Research Center, Department of Cardiovascular Sciences, Lewis Katz School of Medicine at Temple University, Philadelphia, PA 19140
| | - Devin W. Kolmetzky
- Cardiovascular Research Center, Department of Cardiovascular Sciences, Lewis Katz School of Medicine at Temple University, Philadelphia, PA 19140
| | - Oniel Salik
- Cardiovascular Research Center, Department of Cardiovascular Sciences, Lewis Katz School of Medicine at Temple University, Philadelphia, PA 19140
- Health and Exercise Physiology, Ursinus College, Collegeville, PA 19426, USA
| | - Pooja Jadiya
- Cardiovascular Research Center, Department of Cardiovascular Sciences, Lewis Katz School of Medicine at Temple University, Philadelphia, PA 19140
| | - Suresh K. Joseph
- MitoCare Center, Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA, USA
| | - April C. Carpenter
- Health and Exercise Physiology, Ursinus College, Collegeville, PA 19426, USA
| | - György Hajnóczky
- MitoCare Center, Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA, USA
| | - John W. Elrod
- Cardiovascular Research Center, Department of Cardiovascular Sciences, Lewis Katz School of Medicine at Temple University, Philadelphia, PA 19140
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6
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Mitochondrial cristae in health and disease. Int J Biol Macromol 2023; 235:123755. [PMID: 36812974 DOI: 10.1016/j.ijbiomac.2023.123755] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 01/20/2023] [Accepted: 02/09/2023] [Indexed: 02/22/2023]
Abstract
Mitochondria are centers of energy metabolism. The mitochondrial network is shaped by mitochondrial dynamics, including the processes of mitochondrial fission and fusion and cristae remodeling. The cristae folded by the inner mitochondrial membrane are sites of the mitochondrial oxidative phosphorylation (OXPHOS) system. However, the factors and their coordinated interplay in cristae remodeling and linked human diseases have not been fully demonstrated. In this review, we focus on key regulators of cristae structure, including the mitochondrial contact site and cristae organizing system, optic atrophy-1, mitochondrial calcium uniporter, and ATP synthase, which function in the dynamic remodeling of cristae. We summarized their contribution to sustaining functional cristae structure and abnormal cristae morphology, including a decreased number of cristae, enlarged cristae junctions, and cristae as concentric ring structures. These abnormalities directly impact cellular respiration and are caused by dysfunction or deletion of these regulators in diseases such as Parkinson's disease, Leigh syndrome, and dominant optic atrophy. Identifying the important regulators of cristae morphology and understanding their role in sustaining mitochondrial morphology could be applied to explore the pathologies of diseases and to develop relevant therapeutic tools.
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7
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Osterlund EJ, Hirmiz N, Nguyen D, Pemberton JM, Fang Q, Andrews DW. Endoplasmic reticulum protein BIK binds to and inhibits mitochondria-localized antiapoptotic proteins. J Biol Chem 2023; 299:102863. [PMID: 36603764 PMCID: PMC9932132 DOI: 10.1016/j.jbc.2022.102863] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Revised: 11/22/2022] [Accepted: 12/14/2022] [Indexed: 01/04/2023] Open
Abstract
The proapoptotic BCL-2 homology (BH3)-only endoplasmic reticulum (ER)-resident protein BCL-2 interacting killer (BIK) positively regulates mitochondrial outer membrane permeabilization, the point of no return in apoptosis. It is generally accepted that BIK functions at a distance from mitochondria by binding and sequestering antiapoptotic proteins at the ER, thereby promoting ER calcium release. Although BIK is predominantly localized to the ER, we detect by fluorescence lifetime imaging microscopy-FRET microscopy, BH3 region-dependent direct binding between BIK and mitochondria-localized chimeric mutants of the antiapoptotic proteins BCL-XL and BCL-2 in both baby mouse kidney (BMK) and MCF-7 cells. Direct binding was accompanied by cell type-specific differential relocalization in response to coexpression of either BIK or one of its target binding partners, BCL-XL, when coexpressed in cells. In BMK cells with genetic deletion of both BAX and BAK (BMK-double KO), our data suggest that a fraction of BIK protein moves toward mitochondria in response to the expression of a mitochondria-localized BCL-XL mutant. In contrast, in MCF-7 cells, our data suggest that BIK is localized at both ER and mitochondria-associated ER membranes and binds to the mitochondria-localized BCL-XL mutant via relocalization of BCL-XL to ER and mitochondria-associated ER membrane. Rather than functioning at a distance, our data suggest that BIK initiates mitochondrial outer membrane permeabilization via direct interactions with ER and mitochondria-localized antiapoptotic proteins, which occur via ER-mitochondria contact sites, and/or by relocalization of either BIK or antiapoptotic proteins in cells.
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Affiliation(s)
- Elizabeth J Osterlund
- Biological Sciences, Sunnybrook Research Institute, Toronto, Ontario, Canada; Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
| | - Nehad Hirmiz
- Biological Sciences, Sunnybrook Research Institute, Toronto, Ontario, Canada; School of Biomedical Engineering, McMaster University, Hamilton, Ontario, Canada
| | - Dang Nguyen
- Biological Sciences, Sunnybrook Research Institute, Toronto, Ontario, Canada; Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada
| | - James M Pemberton
- Biological Sciences, Sunnybrook Research Institute, Toronto, Ontario, Canada; Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada
| | - Qiyin Fang
- School of Biomedical Engineering, McMaster University, Hamilton, Ontario, Canada; Department of Engineering Physics, McMaster University, Hamilton, Ontario, Canada
| | - David W Andrews
- Biological Sciences, Sunnybrook Research Institute, Toronto, Ontario, Canada; Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada.
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8
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Gottschalk B, Koshenov Z, Waldeck-Weiermair M, Radulović S, Oflaz FE, Hirtl M, Bachkoenig OA, Leitinger G, Malli R, Graier WF. MICU1 controls spatial membrane potential gradients and guides Ca 2+ fluxes within mitochondrial substructures. Commun Biol 2022; 5:649. [PMID: 35778442 PMCID: PMC9249747 DOI: 10.1038/s42003-022-03606-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Accepted: 06/17/2022] [Indexed: 01/19/2023] Open
Abstract
Mitochondrial ultrastructure represents a pinnacle of form and function, with the inner mitochondrial membrane (IMM) forming isolated pockets of cristae membrane (CM), separated from the inner-boundary membrane (IBM) by cristae junctions (CJ). Applying structured illumination and electron microscopy, a novel and fundamental function of MICU1 in mediating Ca2+ control over spatial membrane potential gradients (SMPGs) between CM and IMS was identified. We unveiled alterations of SMPGs by transient CJ openings when Ca2+ binds to MICU1 resulting in spatial cristae depolarization. This Ca2+/MICU1-mediated plasticity of the CJ further provides the mechanistic bedrock of the biphasic mitochondrial Ca2+ uptake kinetics via the mitochondrial Ca2+ uniporter (MCU) during intracellular Ca2+ release: Initially, high Ca2+ opens CJ via Ca2+/MICU1 and allows instant Ca2+ uptake across the CM through constantly active MCU. Second, MCU disseminates into the IBM, thus establishing Ca2+ uptake across the IBM that circumvents the CM. Under the condition of MICU1 methylation by PRMT1 in aging or cancer, UCP2 that binds to methylated MICU1 destabilizes CJ, disrupts SMPGs, and facilitates fast Ca2+ uptake via the CM.
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Affiliation(s)
- Benjamin Gottschalk
- grid.11598.340000 0000 8988 2476Gottfried Schatz Research Center: Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Zhanat Koshenov
- grid.11598.340000 0000 8988 2476Gottfried Schatz Research Center: Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Markus Waldeck-Weiermair
- grid.11598.340000 0000 8988 2476Gottfried Schatz Research Center: Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Snježana Radulović
- grid.11598.340000 0000 8988 2476Gottfried Schatz Research Center: Cell Biology, Histology and Embryology, Medical University of Graz, Graz, Austria
| | - Furkan E. Oflaz
- grid.11598.340000 0000 8988 2476Gottfried Schatz Research Center: Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Martin Hirtl
- grid.11598.340000 0000 8988 2476Gottfried Schatz Research Center: Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Olaf A. Bachkoenig
- grid.11598.340000 0000 8988 2476Gottfried Schatz Research Center: Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Gerd Leitinger
- grid.11598.340000 0000 8988 2476Gottfried Schatz Research Center: Cell Biology, Histology and Embryology, Medical University of Graz, Graz, Austria
| | - Roland Malli
- grid.11598.340000 0000 8988 2476Gottfried Schatz Research Center: Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria ,grid.452216.6BioTechMed Graz, Graz, Austria
| | - Wolfgang F. Graier
- grid.11598.340000 0000 8988 2476Gottfried Schatz Research Center: Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria ,grid.452216.6BioTechMed Graz, Graz, Austria
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9
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Chen MM, Li Y, Deng SL, Zhao Y, Lian ZX, Yu K. Mitochondrial Function and Reactive Oxygen/Nitrogen Species in Skeletal Muscle. Front Cell Dev Biol 2022; 10:826981. [PMID: 35265618 PMCID: PMC8898899 DOI: 10.3389/fcell.2022.826981] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 01/26/2022] [Indexed: 12/06/2022] Open
Abstract
Skeletal muscle fibers contain a large number of mitochondria, which produce ATP through oxidative phosphorylation (OXPHOS) and provide energy for muscle contraction. In this process, mitochondria also produce several types of "reactive species" as side product, such as reactive oxygen species and reactive nitrogen species which have attracted interest. Mitochondria have been proven to have an essential role in the production of skeletal muscle reactive oxygen/nitrogen species (RONS). Traditionally, the elevation in RONS production is related to oxidative stress, leading to impaired skeletal muscle contractility and muscle atrophy. However, recent studies have shown that the optimal RONS level under the action of antioxidants is a critical physiological signal in skeletal muscle. Here, we will review the origin and physiological functions of RONS, mitochondrial structure and function, mitochondrial dynamics, and the coupling between RONS and mitochondrial oxidative stress. The crosstalk mechanism between mitochondrial function and RONS in skeletal muscle and its regulation of muscle stem cell fate and myogenesis will also be discussed. In all, this review aims to describe a comprehensive and systematic network for the interaction between skeletal muscle mitochondrial function and RONS.
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Affiliation(s)
- Ming-Ming Chen
- College of Animal Science and Technology, China Agricultural University, Beijing, China
| | - Yan Li
- College of Animal Science and Technology, China Agricultural University, Beijing, China
| | - Shou-Long Deng
- NHC Key Laboratory of Human Disease Comparative Medicine, Institute of Laboratory Animal Sciences, Chinese Academy of Medical Sciences and Comparative Medicine Center, Peking Union Medical College, Beijing, China
| | - Yue Zhao
- College of Animal Science and Technology, China Agricultural University, Beijing, China
| | - Zheng-Xing Lian
- College of Animal Science and Technology, China Agricultural University, Beijing, China
| | - Kun Yu
- College of Animal Science and Technology, China Agricultural University, Beijing, China
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10
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Cartes-Saavedra B, Macuada J, Lagos D, Arancibia D, Andrés ME, Yu-Wai-Man P, Hajnóczky G, Eisner V. OPA1 Modulates Mitochondrial Ca 2+ Uptake Through ER-Mitochondria Coupling. Front Cell Dev Biol 2022; 9:774108. [PMID: 35047497 PMCID: PMC8762365 DOI: 10.3389/fcell.2021.774108] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2021] [Accepted: 11/30/2021] [Indexed: 11/16/2022] Open
Abstract
Autosomal Dominant Optic Atrophy (ADOA), a disease that causes blindness and other neurological disorders, is linked to OPA1 mutations. OPA1, dependent on its GTPase and GED domains, governs inner mitochondrial membrane (IMM) fusion and cristae organization, which are central to oxidative metabolism. Mitochondrial dynamics and IMM organization have also been implicated in Ca2+ homeostasis and signaling but the specific involvements of OPA1 in Ca2+ dynamics remain to be established. Here we studied the possible outcomes of OPA1 and its ADOA-linked mutations in Ca2+ homeostasis using rescue and overexpression strategies in Opa1-deficient and wild-type murine embryonic fibroblasts (MEFs), respectively and in human ADOA-derived fibroblasts. MEFs lacking Opa1 required less Ca2+ mobilization from the endoplasmic reticulum (ER) to induce a mitochondrial matrix [Ca2+] rise ([Ca2+]mito). This was associated with closer ER-mitochondria contacts and no significant changes in the mitochondrial calcium uniporter complex. Patient cells carrying OPA1 GTPase or GED domain mutations also exhibited altered Ca2+ homeostasis, and the mutations associated with lower OPA1 levels displayed closer ER-mitochondria gaps. Furthermore, in Opa1 -/- MEF background, we found that acute expression of OPA1 GTPase mutants but no GED mutants, partially restored cytosolic [Ca2+] ([Ca2+]cyto) needed for a prompt [Ca2+]mito rise. Finally, OPA1 mutants' overexpression in WT MEFs disrupted Ca2+ homeostasis, partially recapitulating the observations in ADOA patient cells. Thus, OPA1 modulates functional ER-mitochondria coupling likely through the OPA1 GED domain in Opa1 -/- MEFs. However, the co-existence of WT and mutant forms of OPA1 in patients promotes an imbalance of Ca2+ homeostasis without a domain-specific effect, likely contributing to the overall ADOA progress.
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Affiliation(s)
- Benjamín Cartes-Saavedra
- Departamento Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
- MitoCare Center for Mitochondrial Imaging Research and Diagnostics, Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA, United States
| | - Josefa Macuada
- Departamento Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Daniel Lagos
- Departamento Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Duxan Arancibia
- Departamento Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - María E. Andrés
- Departamento Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Patrick Yu-Wai-Man
- UCL Institute of Ophthalmology, University College London, London, United Kingdom
- Moorfields Eye Hospital NHS Foundation Trust, London, United Kingdom
- Cambridge Eye Unit, Addenbrooke’s Hospital, Cambridge University Hospitals, Cambridge, United Kingdom
- John van Geest Centre for Brain Repair and MRC Mitochondrial Biology Unit, Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom
| | - György Hajnóczky
- MitoCare Center for Mitochondrial Imaging Research and Diagnostics, Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA, United States
| | - Verónica Eisner
- Departamento Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
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11
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Friedman JR. Mitochondria from the Outside in: The Relationship Between Inter-Organelle Crosstalk and Mitochondrial Internal Organization. CONTACT (THOUSAND OAKS (VENTURA COUNTY, CALIF.)) 2022; 5:25152564221133267. [PMID: 36329759 PMCID: PMC9629538 DOI: 10.1177/25152564221133267] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Accepted: 09/29/2022] [Indexed: 11/20/2022]
Abstract
A fundamental role of membrane-bound organelles is the compartmentalization and organization of cellular processes. Mitochondria perform an immense number of metabolic chemical reactions and to efficiently regulate these, the organelle organizes its inner membrane into distinct morphological domains, including its characteristic cristae membranes. In recent years, a structural feature of increasing apparent importance is the inter-connection between the mitochondrial exterior and other organelles at membrane contact sites (MCSs). Mitochondria form MCSs with almost every other organelle in the cell, including the endoplasmic reticulum, lipid droplets, and lysosomes, to coordinate global cellular metabolism with mitochondrial metabolism. However, these MCSs not only facilitate the transport of metabolites between organelles, but also directly impinge on the physical shape and functional organization inside mitochondria. In this review, we highlight recent advances in our understanding of how physical connections between other organelles and mitochondria both directly and indirectly influence the internal architecture of mitochondria.
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Affiliation(s)
- Jonathan R. Friedman
- Department of Cell Biology, University of Texas Southwestern Medical
Center, Dallas, TX, USA
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12
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Gottschalk B, Madreiter-Sokolowski CT, Graier WF. Cristae junction as a fundamental switchboard for mitochondrial ion signaling and bioenergetics. Cell Calcium 2022; 101:102517. [PMID: 34915234 DOI: 10.1016/j.ceca.2021.102517] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Accepted: 12/08/2021] [Indexed: 12/31/2022]
Abstract
OPA1 and MICU1 are both involved in the regulation of mitochondrial Ca2+ uptake and the stabilization of the cristae junction, which separates the inner mitochondrial membrane into the interboundary membrane and the cristae membrane. In this mini-review, we focus on the synergetic control of OPA1 and MICU1 on the cristae junction that serves as a fundamental regulator of multiple mitochondrial functions. In particular, we point to the critical role of an adaptive cristae junction permeability in mitochondrial Ca2+ signaling, spatial H+ gradients and mitochondrial membrane potential, metabolic activity, and apoptosis. These characteristics bear on a distinct localization of the oxidative phosphorylation machinery, the FoF1-ATPase, and mitochondrial Ca2+uniporter (MCU) within sections of the inner mitochondrial membrane isolated by the cristae junction and regulated by proteins like OPA1 and MICU1. We specifically focus on the impact of MICU1-regulated cristae junction on the activity and distribution of MCU within the complex ultrastructure of mitochondria.
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Affiliation(s)
- Benjamin Gottschalk
- Gottfried Schatz Research Center: Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstraße 6/6, Graz, 8010 Austria
| | - Corina T Madreiter-Sokolowski
- Gottfried Schatz Research Center: Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstraße 6/6, Graz, 8010 Austria
| | - Wolfgang F Graier
- Gottfried Schatz Research Center: Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstraße 6/6, Graz, 8010 Austria; BioTechMed, Graz.
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13
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Castro-Sepúlveda M, Morio B, Tuñón-Suárez M, Jannas-Vela S, Díaz-Castro F, Rieusset J, Zbinden-Foncea H. The fasting-feeding metabolic transition regulates mitochondrial dynamics. FASEB J 2021; 35:e21891. [PMID: 34569666 DOI: 10.1096/fj.202100929r] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Revised: 08/08/2021] [Accepted: 08/16/2021] [Indexed: 11/11/2022]
Abstract
In humans, insulin resistance has been linked to an impaired metabolic transition from fasting to feeding (metabolic flexibility; MetFlex). Previous studies suggest that mitochondrial dynamics response is a putative determinant of MetFlex; however, this has not been studied in humans. Thus, the aim of this study was to investigate the mitochondrial dynamics response in the metabolic transition from fasting to feeding in human peripheral blood mononuclear cells (PBMCs). Six male subjects fasted for 16 h (fasting), immediately after which they consumed a 75-g oral glucose load (glucose). In both fasting and glucose conditions, blood samples were taken to obtain PBMCs. Mitochondrial dynamics were assessed by electron microscopy images. We exposed in vitro acetoacetate-treated PBMCs to the specific IP3R inhibitor Xestospongin B (XeB) to reduce IP3R-mediated mitochondrial Ca2+ accumulation. This allowed us to evaluate the role of ER-mitochondria Ca2+ exchange in the mitochondrial dynamic response to substrate availability. To determine whether PBMCs could be used in obesity context (low MetFlex), we measured mitochondrial dynamics in mouse spleen-derived lymphocytes from WT and ob/ob mice. We demonstrated that the transition from fasting to feeding reduces mitochondria-ER interactions, induces mitochondrial fission and reduces mitochondrial cristae density in human PBMCs. In addition, we demonstrated that IP3R activity is key in the mitochondrial dynamics response when PBMCs are treated with a fasting-substrate in vitro. In murine mononuclear-cells, we confirmed that mitochondria-ER interactions are regulated in the fasted-fed transition and we further highlight mitochondria-ER miscommunication in PBMCs of diabetic mice. In conclusion, our results demonstrate that the fasting/feeding transition reduces mitochondria-ER interactions, induces mitochondrial fission and reduces mitochondrial cristae density in human PBMCs, and that IP3R activity may potentially play a central role.
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Affiliation(s)
- Mauricio Castro-Sepúlveda
- Laboratorio de Ciencias del Ejercicio, Escuela de Kinesiologia, Facultad de Medicina, Universidad Finis Terrae, Santiago, Chile.,Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Béatrice Morio
- CarMeN Laboratory, UMR INSERM U1060/INRA U13397, Université Claude Bernard Lyon 1, Pierre-Bénite, France
| | - Mauro Tuñón-Suárez
- Laboratorio de Ciencias del Ejercicio, Escuela de Kinesiologia, Facultad de Medicina, Universidad Finis Terrae, Santiago, Chile
| | - Sebastian Jannas-Vela
- Laboratorio de Ciencias del Ejercicio, Escuela de Kinesiologia, Facultad de Medicina, Universidad Finis Terrae, Santiago, Chile
| | - Francisco Díaz-Castro
- Laboratorio de Investigación en Nutrición y Actividad Física (LABINAF), Instituto de Nutrición y Tecnología de los Alimentos, Universidad de Chile, Santiago, Chile.,Laboratorio de Autofagia y Metabolismo, Departamento de Fisiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Jennifer Rieusset
- CarMeN Laboratory, UMR INSERM U1060/INRA U13397, Université Claude Bernard Lyon 1, Pierre-Bénite, France
| | - Hermann Zbinden-Foncea
- Laboratorio de Ciencias del Ejercicio, Escuela de Kinesiologia, Facultad de Medicina, Universidad Finis Terrae, Santiago, Chile.,Centro de Salud Deportiva, Clínica Santa María, Santiago, Chile
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14
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Jadiya P, Garbincius JF, Elrod JW. Reappraisal of metabolic dysfunction in neurodegeneration: Focus on mitochondrial function and calcium signaling. Acta Neuropathol Commun 2021; 9:124. [PMID: 34233766 PMCID: PMC8262011 DOI: 10.1186/s40478-021-01224-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Accepted: 06/27/2021] [Indexed: 02/06/2023] Open
Abstract
The cellular and molecular mechanisms that drive neurodegeneration remain poorly defined. Recent clinical trial failures, difficult diagnosis, uncertain etiology, and lack of curative therapies prompted us to re-examine other hypotheses of neurodegenerative pathogenesis. Recent reports establish that mitochondrial and calcium dysregulation occur early in many neurodegenerative diseases (NDDs), including Alzheimer's disease, Parkinson's disease, Huntington's disease, and others. However, causal molecular evidence of mitochondrial and metabolic contributions to pathogenesis remains insufficient. Here we summarize the data supporting the hypothesis that mitochondrial and metabolic dysfunction result from diverse etiologies of neuropathology. We provide a current and comprehensive review of the literature and interpret that defective mitochondrial metabolism is upstream and primary to protein aggregation and other dogmatic hypotheses of NDDs. Finally, we identify gaps in knowledge and propose therapeutic modulation of mCa2+ exchange and mitochondrial function to alleviate metabolic impairments and treat NDDs.
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Affiliation(s)
- Pooja Jadiya
- Center for Translational Medicine, Lewis Katz School of Medicine at Temple University, 3500 N Broad St, MERB 949, Philadelphia, PA, 19140, USA
| | - Joanne F Garbincius
- Center for Translational Medicine, Lewis Katz School of Medicine at Temple University, 3500 N Broad St, MERB 949, Philadelphia, PA, 19140, USA
| | - John W Elrod
- Center for Translational Medicine, Lewis Katz School of Medicine at Temple University, 3500 N Broad St, MERB 949, Philadelphia, PA, 19140, USA.
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15
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Yang M, Li C, Sun L. Mitochondria-Associated Membranes (MAMs): A Novel Therapeutic Target for Treating Metabolic Syndrome. Curr Med Chem 2021; 28:1347-1362. [PMID: 32048952 DOI: 10.2174/0929867327666200212100644] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 01/24/2020] [Accepted: 01/26/2020] [Indexed: 11/22/2022]
Abstract
Mitochondria-associated Endoplasmic Reticulum (ER) Membranes (MAMs) are the cellular structures that connect the ER and mitochondria and mediate communication between these two organelles. MAMs have been demonstrated to be involved in calcium signaling, lipid transfer, mitochondrial dynamic change, mitophagy, and the ER stress response. In addition, MAMs are critical for metabolic regulation, and their dysfunction has been reported to be associated with metabolic syndrome, including the downregulation of insulin signaling and the accelerated progression of hyperlipidemia, obesity, and hypertension. This review covers the roles of MAMs in regulating insulin sensitivity and the molecular mechanism underlying MAM-regulated cellular metabolism and reveals the potential of MAMs as a therapeutic target in treating metabolic syndrome.
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Affiliation(s)
- Ming Yang
- Hunan Key Laboratory of Kidney Disease and Blood Purification, Department of Nephrology, the Second Xiangya Hospital, Central South University, No. 139 Renmin Middle Road, Changsha 410011, Hunan, China
| | - Chenrui Li
- Hunan Key Laboratory of Kidney Disease and Blood Purification, Department of Nephrology, the Second Xiangya Hospital, Central South University, No. 139 Renmin Middle Road, Changsha 410011, Hunan, China
| | - Lin Sun
- Hunan Key Laboratory of Kidney Disease and Blood Purification, Department of Nephrology, the Second Xiangya Hospital, Central South University, No. 139 Renmin Middle Road, Changsha 410011, Hunan, China
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16
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Madreiter-Sokolowski CT, Ramadani-Muja J, Ziomek G, Burgstaller S, Bischof H, Koshenov Z, Gottschalk B, Malli R, Graier WF. Tracking intra- and inter-organelle signaling of mitochondria. FEBS J 2019; 286:4378-4401. [PMID: 31661602 PMCID: PMC6899612 DOI: 10.1111/febs.15103] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Revised: 08/19/2019] [Accepted: 10/22/2019] [Indexed: 12/15/2022]
Abstract
Mitochondria are as highly specialized organelles and masters of the cellular energy metabolism in a constant and dynamic interplay with their cellular environment, providing adenosine triphosphate, buffering Ca2+ and fundamentally contributing to various signaling pathways. Hence, such broad field of action within eukaryotic cells requires a high level of structural and functional adaptation. Therefore, mitochondria are constantly moving and undergoing fusion and fission processes, changing their shape and their interaction with other organelles. Moreover, mitochondrial activity gets fine-tuned by intra- and interorganelle H+ , K+ , Na+ , and Ca2+ signaling. In this review, we provide an up-to-date overview on mitochondrial strategies to adapt and respond to, as well as affect, their cellular environment. We also present cutting-edge technologies used to track and investigate subcellular signaling, essential to the understanding of various physiological and pathophysiological processes.
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Affiliation(s)
- Corina T Madreiter-Sokolowski
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Austria.,Department of Health Sciences and Technology, ETH Zurich, Schwerzenbach, Switzerland
| | - Jeta Ramadani-Muja
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Austria
| | - Gabriela Ziomek
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Austria
| | - Sandra Burgstaller
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Austria
| | - Helmut Bischof
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Austria
| | - Zhanat Koshenov
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Austria
| | - Benjamin Gottschalk
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Austria
| | - Roland Malli
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Austria.,BioTechMed, Graz, Austria
| | - Wolfgang F Graier
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Austria.,BioTechMed, Graz, Austria
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17
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Waldeck-Weiermair M, Gottschalk B, Madreiter-Sokolowski CT, Ramadani-Muja J, Ziomek G, Klec C, Burgstaller S, Bischof H, Depaoli MR, Eroglu E, Malli R, Graier WF. Development and Application of Sub-Mitochondrial Targeted Ca 2 + Biosensors. Front Cell Neurosci 2019; 13:449. [PMID: 31636543 PMCID: PMC6788349 DOI: 10.3389/fncel.2019.00449] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Accepted: 09/20/2019] [Indexed: 12/20/2022] Open
Abstract
Mitochondrial Ca2+ uptake into the mitochondrial matrix is a well-established mechanism. However, the sub-organellar Ca2+ kinetics remain elusive. In the present work we identified novel site-specific targeting sequences for the intermembrane space (IMS) and the cristae lumen (CL). We used these novel targeting peptides to develop green- and red- Ca2+ biosensors targeted to the IMS and to the CL. Based on their distinctive spectral properties, and comparable sensitivities these novel constructs were suitable to visualize Ca2+-levels in various (sub) compartments in a multi-chromatic manner. Functional studies that applied these new biosensors revealed that knockdown of MCU and EMRE yielded elevated Ca2+ levels inside the CL but not the IMS in response to IP3-generating agonists. Knockdown of VDAC1, however, strongly impeded the transfer of Ca2+ through the OMM while the cytosolic Ca2+ signal remained unchanged. The novel sub-mitochondrially targeted Ca2+ biosensors proved to be suitable for Ca2+ imaging with high spatial and temporal resolution in a multi-chromatic manner allowing simultaneous measurements. These informative biosensors will facilitate efforts to dissect the complex sub-mitochondrial Ca2+ signaling under (patho)physiological conditions.
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Affiliation(s)
- Markus Waldeck-Weiermair
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria
| | - Benjamin Gottschalk
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria
| | - Corina T. Madreiter-Sokolowski
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria
- Energy Metabolism Laboratory, Institute of Translational Medicine, D-HEST, Swiss Federal Institute of Technology (ETH), Zurich, Switzerland
| | - Jeta Ramadani-Muja
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria
| | - Gabriela Ziomek
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria
| | - Christiane Klec
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria
- Department of Internal Medicine, Division of Oncology, Medical University of Graz, Graz, Austria
| | - Sandra Burgstaller
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria
| | - Helmut Bischof
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria
| | - Maria R. Depaoli
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria
| | - Emrah Eroglu
- Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, United States
| | - Roland Malli
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria
- BioTechMed-Graz, Graz, Austria
| | - Wolfgang F. Graier
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria
- BioTechMed-Graz, Graz, Austria
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18
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Gottschalk B, Klec C, Leitinger G, Bernhart E, Rost R, Bischof H, Madreiter-Sokolowski CT, Radulović S, Eroglu E, Sattler W, Waldeck-Weiermair M, Malli R, Graier WF. MICU1 controls cristae junction and spatially anchors mitochondrial Ca 2+ uniporter complex. Nat Commun 2019; 10:3732. [PMID: 31427612 PMCID: PMC6700202 DOI: 10.1038/s41467-019-11692-x] [Citation(s) in RCA: 85] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Accepted: 07/30/2019] [Indexed: 12/15/2022] Open
Abstract
Recently identified core proteins (MICU1, MCU, EMRE) forming the mitochondrial Ca2+ uniporter complex propelled investigations into its physiological workings. Here, we apply structured illumination microscopy to visualize and localize these proteins in living cells. Our data show that MICU1 localizes at the inner boundary membrane (IBM) due to electrostatic interaction of its polybasic domain. Moreover, this exclusive localization of MICU1 is important for the stability of cristae junctions (CJ), cytochrome c release and mitochondrial membrane potential. In contrast to MICU1, MCU and EMRE are homogeneously distributed at the inner mitochondrial membrane under resting conditions. However, upon Ca2+ elevation MCU and EMRE dynamically accumulate at the IBM in a MICU1-dependent manner. Eventually, our findings unveil an essential function of MICU1 in CJ stabilization and provide mechanistic insights of how sophistically MICU1 controls the MCU-Complex while maintaining the structural mitochondrial membrane framework.
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Affiliation(s)
- Benjamin Gottschalk
- 0000 0000 8988 2476grid.11598.34Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
| | - Christiane Klec
- 0000 0000 8988 2476grid.11598.34Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
| | - Gerd Leitinger
- 0000 0000 8988 2476grid.11598.34Gottfried Schatz Research Center, Cell Biology, Histology and Embryology, Medical University of Graz, Neue Stiftingtalstraße 6/2, 8010 Graz, Austria
| | - Eva Bernhart
- 0000 0000 8988 2476grid.11598.34Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
| | - René Rost
- 0000 0000 8988 2476grid.11598.34Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
| | - Helmut Bischof
- 0000 0000 8988 2476grid.11598.34Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
| | - Corina T. Madreiter-Sokolowski
- 0000 0000 8988 2476grid.11598.34Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
| | - Snježana Radulović
- 0000 0000 8988 2476grid.11598.34Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria ,0000 0000 8988 2476grid.11598.34Gottfried Schatz Research Center, Cell Biology, Histology and Embryology, Medical University of Graz, Neue Stiftingtalstraße 6/2, 8010 Graz, Austria
| | - Emrah Eroglu
- 0000 0000 8988 2476grid.11598.34Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
| | - Wolfgang Sattler
- 0000 0000 8988 2476grid.11598.34Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria ,grid.452216.6BioTechMed Graz, Mozartgasse 12/2, Graz, 8010 Austria
| | - Markus Waldeck-Weiermair
- 0000 0000 8988 2476grid.11598.34Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
| | - Roland Malli
- 0000 0000 8988 2476grid.11598.34Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria ,grid.452216.6BioTechMed Graz, Mozartgasse 12/2, Graz, 8010 Austria
| | - Wolfgang F. Graier
- 0000 0000 8988 2476grid.11598.34Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria ,grid.452216.6BioTechMed Graz, Mozartgasse 12/2, Graz, 8010 Austria
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19
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Madreiter-Sokolowski CT, Malli RM, Graier WF. Mitochondrial-Endoplasmic Reticulum Interplay: A Lifelong On-Off Relationship? ACTA ACUST UNITED AC 2019; 2:2515256419861227. [PMID: 31396581 PMCID: PMC6687505 DOI: 10.1177/2515256419861227] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
This article comments recent publications that highlight an intriguing importance of specific settings in the interaction between the mitochondria and the endoplasmic reticulum to ensure cell-specific functions like the responsiveness to elevated glucose in pancreatic β-cells. Hence, alterations of the mitochondria–endoplasmic reticulum communications under various pathological conditions like aging or cancer often come with enhanced Ca2+ transfer that, in turn, yields stimulation of basal mitochondrial activity to meet the increasing adenosine triphosphate demand of the very cell. Such observations identify mitochondria-associated membranes as potential target for new therapeutic strategies against aging or cancer.
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Affiliation(s)
- Corina T Madreiter-Sokolowski
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria.,Department of Health Sciences and Technology, ETH Zurich, Zurich, Switzerland
| | - Roland M Malli
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria.,BioTechMed Graz, Graz, Austria
| | - Wolfgang F Graier
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria.,BioTechMed Graz, Graz, Austria
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20
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Affiliation(s)
- Roland Malli
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria
| | - Wolfgang F Graier
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria.
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21
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Abstract
Significance: In addition to their classical role in cellular ATP production, mitochondria are of key relevance in various (patho)physiological mechanisms including second messenger signaling, neuro-transduction, immune responses and death induction. Recent Advances: Within cells, mitochondria are motile and display temporal changes in internal and external structure ("mitochondrial dynamics"). During the last decade, substantial empirical and in silico evidence was presented demonstrating that mitochondrial dynamics impacts on mitochondrial function and vice versa. Critical Issues: However, a comprehensive and quantitative understanding of the bidirectional links between mitochondrial external shape, internal structure and function ("morphofunction") is still lacking. The latter particularly hampers our understanding of the functional properties and behavior of individual mitochondrial within single living cells. Future Directions: In this review we discuss the concept of mitochondrial morphofunction in mammalian cells, primarily using experimental evidence obtained within the last decade. The topic is introduced by briefly presenting the central role of mitochondria in cell physiology and the importance of the mitochondrial electron transport chain (ETC) therein. Next, we summarize in detail how mitochondrial (ultra)structure is controlled and discuss empirical evidence regarding the equivalence of mitochondrial (ultra)structure and function. Finally, we provide a brief summary of how mitochondrial morphofunction can be quantified at the level of single cells and mitochondria, how mitochondrial ultrastructure/volume impacts on mitochondrial bioreactions and intramitochondrial protein diffusion, and how mitochondrial morphofunction can be targeted by small molecules.
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Affiliation(s)
- Elianne P. Bulthuis
- Department of Biochemistry (286), Radboud Institute for Molecular Life Sciences, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Merel J.W. Adjobo-Hermans
- Department of Biochemistry (286), Radboud Institute for Molecular Life Sciences, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Peter H.G.M. Willems
- Department of Biochemistry (286), Radboud Institute for Molecular Life Sciences, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Werner J.H. Koopman
- Department of Biochemistry (286), Radboud Institute for Molecular Life Sciences, Radboud University Medical Centre, Nijmegen, The Netherlands
- Address correspondence to: Dr. Werner J.H. Koopman, Department of Biochemistry (286), Radboud Institute for Molecular Life Sciences, Radboud University Medical Centre, P.O. Box 9101, Nijmegen NL-6500 HB, The Netherlands
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