51
|
Calcium Signaling Regulates Autophagy and Apoptosis. Cells 2021; 10:cells10082125. [PMID: 34440894 PMCID: PMC8394685 DOI: 10.3390/cells10082125] [Citation(s) in RCA: 86] [Impact Index Per Article: 28.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 08/10/2021] [Accepted: 08/17/2021] [Indexed: 02/07/2023] Open
Abstract
Calcium (Ca2+) functions as a second messenger that is critical in regulating fundamental physiological functions such as cell growth/development, cell survival, neuronal development and/or the maintenance of cellular functions. The coordination among various proteins/pumps/Ca2+ channels and Ca2+ storage in various organelles is critical in maintaining cytosolic Ca2+ levels that provide the spatial resolution needed for cellular homeostasis. An important regulatory aspect of Ca2+ homeostasis is a store operated Ca2+ entry (SOCE) mechanism that is activated by the depletion of Ca2+ from internal ER stores and has gained much attention for influencing functions in both excitable and non-excitable cells. Ca2+ has been shown to regulate opposing functions such as autophagy, that promote cell survival; on the other hand, Ca2+ also regulates programmed cell death processes such as apoptosis. The functional significance of the TRP/Orai channels has been elaborately studied; however, information on how they can modulate opposing functions and modulate function in excitable and non-excitable cells is limited. Importantly, perturbations in SOCE have been implicated in a spectrum of pathological neurodegenerative conditions. The critical role of autophagy machinery in the pathogenesis of neurodegenerative diseases such as Alzheimer’s, Parkinson’s, and Huntington’s diseases, would presumably unveil avenues for plausible therapeutic interventions for these diseases. We thus review the role of SOCE-regulated Ca2+ signaling in modulating these diverse functions in stem cell, immune regulation and neuromodulation.
Collapse
|
52
|
Ca 2+ handling at the mitochondria-ER contact sites in neurodegeneration. Cell Calcium 2021; 98:102453. [PMID: 34399235 DOI: 10.1016/j.ceca.2021.102453] [Citation(s) in RCA: 47] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 08/03/2021] [Accepted: 08/03/2021] [Indexed: 12/12/2022]
Abstract
Mitochondria-endoplasmic reticulum (ER) contact sites (MERCS) are morpho-functional units, formed at the loci of close apposition of the ER-forming endomembrane and outer mitochondrial membrane (OMM). These sites contribute to fundamental cellular processes including lipid biosynthesis, autophagy, apoptosis, ER-stress and calcium (Ca2+) signalling. At MERCS, Ca2+ ions are transferred from the ER directly to mitochondria through a core protein complex composed of inositol-1,4,5 trisphosphate receptor (InsP3R), voltage-gated anion channel 1 (VDAC1), mitochondrial calcium uniporter (MCU) and adaptor protein glucose-regulated protein 75 (Grp75); this complex is regulated by several associated proteins. Deregulation of ER-mitochondria Ca2+ transfer contributes to pathogenesis of neurodegenerative and other diseases. The efficacy of Ca2+ transfer between ER and mitochondria depends on the protein composition of MERCS, which controls ER-mitochondria interaction regulating, for example, the transversal distance between ER membrane and OMM and the extension of the longitudinal interface between ER and mitochondria. These parameters are altered in neurodegeneration. Here we overview the ER and mitochondrial Ca2+ homeostasis, the composition of ER-mitochondrial Ca2+ transfer machinery and alterations of the ER-mitochondria Ca2+ transfer in three major neurodegenerative diseases: motor neurone diseases, Parkinson disease and Alzheimer's disease.
Collapse
|
53
|
Morciano G, Naumova N, Koprowski P, Valente S, Sardão VA, Potes Y, Rimessi A, Wieckowski MR, Oliveira PJ. The mitochondrial permeability transition pore: an evolving concept critical for cell life and death. Biol Rev Camb Philos Soc 2021; 96:2489-2521. [PMID: 34155777 DOI: 10.1111/brv.12764] [Citation(s) in RCA: 52] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 05/28/2021] [Accepted: 06/04/2021] [Indexed: 02/06/2023]
Abstract
In this review, we summarize current knowledge of perhaps one of the most intriguing phenomena in cell biology: the mitochondrial permeability transition pore (mPTP). This phenomenon, which was initially observed as a sudden loss of inner mitochondrial membrane impermeability caused by excessive calcium, has been studied for almost 50 years, and still no definitive answer has been provided regarding its mechanisms. From its initial consideration as an in vitro artifact to the current notion that the mPTP is a phenomenon with physiological and pathological implications, a long road has been travelled. We here summarize the role of mitochondria in cytosolic calcium control and the evolving concepts regarding the mitochondrial permeability transition (mPT) and the mPTP. We show how the evolving mPTP models and mechanisms, which involve many proposed mitochondrial protein components, have arisen from methodological advances and more complex biological models. We describe how scientific progress and methodological advances have allowed milestone discoveries on mPTP regulation and composition and its recognition as a valid target for drug development and a critical component of mitochondrial biology.
Collapse
Affiliation(s)
- Giampaolo Morciano
- Maria Cecilia Hospital, GVM Care & Research, Via Corriera 1, Cotignola, Ravenna, 48033, Italy.,Department of Medical Sciences, Section of Experimental Medicine, Laboratory for Technologies of Advanced Therapies (LTTA), University of Ferrara, Via Fossato di Mortara 70, Ferrara, 44121, Italy
| | - Natalia Naumova
- Department of Cardiac Thoracic and Vascular Sciences and Public Health, University of Padua Medical School, Via Giustiniani 2, Padova, 35128, Italy
| | - Piotr Koprowski
- Laboratory of Intracellular Ion Channels, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, Warsaw, 02-093, Poland
| | - Sara Valente
- CNC - Center for Neuroscience and Cell Biology, CIBB - Centre for Innovative Biomedicine and Biotechnology, University of Coimbra, UC Biotech, Biocant Park, Cantanhede, 3060-197, Portugal
| | - Vilma A Sardão
- CNC - Center for Neuroscience and Cell Biology, CIBB - Centre for Innovative Biomedicine and Biotechnology, University of Coimbra, UC Biotech, Biocant Park, Cantanhede, 3060-197, Portugal
| | - Yaiza Potes
- Laboratory of Mitochondrial Biology and Metabolism, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, Warsaw, 02-093, Poland
| | - Alessandro Rimessi
- Department of Medical Sciences, Section of Experimental Medicine, Laboratory for Technologies of Advanced Therapies (LTTA), University of Ferrara, Via Fossato di Mortara 70, Ferrara, 44121, Italy
| | - Mariusz R Wieckowski
- Laboratory of Mitochondrial Biology and Metabolism, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, Warsaw, 02-093, Poland
| | - Paulo J Oliveira
- CNC - Center for Neuroscience and Cell Biology, CIBB - Centre for Innovative Biomedicine and Biotechnology, University of Coimbra, UC Biotech, Biocant Park, Cantanhede, 3060-197, Portugal
| |
Collapse
|
54
|
Stavsky A, Stoler O, Kostic M, Katoshevsky T, Assali EA, Savic I, Amitai Y, Prokisch H, Leiz S, Daumer-Haas C, Fleidervish I, Perocchi F, Gitler D, Sekler I. Aberrant activity of mitochondrial NCLX is linked to impaired synaptic transmission and is associated with mental retardation. Commun Biol 2021; 4:666. [PMID: 34079053 PMCID: PMC8172942 DOI: 10.1038/s42003-021-02114-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Accepted: 03/22/2021] [Indexed: 02/04/2023] Open
Abstract
Calcium dynamics control synaptic transmission. Calcium triggers synaptic vesicle fusion, determines release probability, modulates vesicle recycling, participates in long-term plasticity and regulates cellular metabolism. Mitochondria, the main source of cellular energy, serve as calcium signaling hubs. Mitochondrial calcium transients are primarily determined by the balance between calcium influx, mediated by the mitochondrial calcium uniporter (MCU), and calcium efflux through the sodium/lithium/calcium exchanger (NCLX). We identified a human recessive missense SLC8B1 variant that impairs NCLX activity and is associated with severe mental retardation. On this basis, we examined the effect of deleting NCLX in mice on mitochondrial and synaptic calcium homeostasis, synaptic activity, and plasticity. Neuronal mitochondria exhibited basal calcium overload, membrane depolarization, and a reduction in the amplitude and rate of calcium influx and efflux. We observed smaller cytoplasmic calcium transients in the presynaptic terminals of NCLX-KO neurons, leading to a lower probability of release and weaker transmission. In agreement, synaptic facilitation in NCLX-KO hippocampal slices was enhanced. Importantly, deletion of NCLX abolished long term potentiation of Schaffer collateral synapses. Our results show that NCLX controls presynaptic calcium transients that are crucial for defining synaptic strength as well as short- and long-term plasticity, key elements of learning and memory processes.
Collapse
Affiliation(s)
- Alexandra Stavsky
- Department of Physiology and Cell Biology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
- Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Ohad Stoler
- Department of Physiology and Cell Biology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
- Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Marko Kostic
- Department of Physiology and Cell Biology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
- Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Tomer Katoshevsky
- Department of Physiology and Cell Biology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
- Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Essam A Assali
- Department of Physiology and Cell Biology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
- Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Ivana Savic
- Department of Physiology and Cell Biology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
- Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Yael Amitai
- Department of Physiology and Cell Biology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
- Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Holger Prokisch
- Institute of Human Genetics, School of Medicine, Technische Universität München, Munich, Germany
- Institute of Neurogenomics, Helmholtz Zentrum München, Munich, Germany
| | - Steffen Leiz
- Department of Pediatrics, Klinikum Dritter Orden, Munich, Germany
| | | | - Ilya Fleidervish
- Department of Physiology and Cell Biology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
- Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Fabiana Perocchi
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center (HDC), Helmholtz Zentrum München, Munich, Germany
- Munich Cluster for Systems Neurology, Munich, Germany
| | - Daniel Gitler
- Department of Physiology and Cell Biology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel.
- Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva, Israel.
| | - Israel Sekler
- Department of Physiology and Cell Biology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel.
- Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva, Israel.
| |
Collapse
|
55
|
Wilson EL, Metzakopian E. ER-mitochondria contact sites in neurodegeneration: genetic screening approaches to investigate novel disease mechanisms. Cell Death Differ 2021; 28:1804-1821. [PMID: 33335290 PMCID: PMC8185109 DOI: 10.1038/s41418-020-00705-8] [Citation(s) in RCA: 70] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Revised: 11/26/2020] [Accepted: 11/30/2020] [Indexed: 12/26/2022] Open
Abstract
Mitochondria-ER contact sites (MERCS) are known to underpin many important cellular homoeostatic functions, including mitochondrial quality control, lipid metabolism, calcium homoeostasis, the unfolded protein response and ER stress. These functions are known to be dysregulated in neurodegenerative diseases, including Parkinson's disease (PD), Alzheimer's disease (AD) and amyloid lateral sclerosis (ALS), and the number of disease-related proteins and genes being associated with MERCS is increasing. However, many details regarding MERCS and their role in neurodegenerative diseases remain unknown. In this review, we aim to summarise the current knowledge regarding the structure and function of MERCS, and to update the field on current research in PD, AD and ALS. Furthermore, we will evaluate high-throughput screening techniques, including RNAi vs CRISPR/Cas9, pooled vs arrayed formats and how these could be combined with current techniques to visualise MERCS. We will consider the advantages and disadvantages of each technique and how it can be utilised to uncover novel protein pathways involved in MERCS dysfunction in neurodegenerative diseases.
Collapse
Affiliation(s)
- Emma Louise Wilson
- UK Dementia Research Institute, Department of Clinical Neuroscience, University of Cambridge, Cambridge, CB2 0AH, UK.
- Open Targets, Wellcome Genome Campus, Hinxton, Cambridge, CB10 1SA, UK.
| | - Emmanouil Metzakopian
- UK Dementia Research Institute, Department of Clinical Neuroscience, University of Cambridge, Cambridge, CB2 0AH, UK.
| |
Collapse
|
56
|
Danese A, Leo S, Rimessi A, Wieckowski MR, Fiorica F, Giorgi C, Pinton P. Cell death as a result of calcium signaling modulation: A cancer-centric prospective. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2021; 1868:119061. [PMID: 33991539 DOI: 10.1016/j.bbamcr.2021.119061] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 04/19/2021] [Accepted: 04/26/2021] [Indexed: 12/14/2022]
Abstract
Calcium ions (Ca2+) and the complex regulatory system governed by Ca2+ signaling have been described to be of crucial importance in numerous aspects related to cell life and death decisions, especially in recent years. The growing attention given to this second messenger is justified by the pleiotropic nature of Ca2+-binding proteins and transporters and their consequent involvement in cell fate decisions. A growing number of works highlight that deregulation of Ca2+ signaling and homoeostasis is often deleterious and drives pathological conditions; in particular, a disruption of the main Ca2+-mediated death mechanisms may lead to uncontrolled cell growth that results in cancer. In this work, we review the latest useful evidence to better understand the complex network of pathways by which Ca2+ regulates cell life and death decisions.
Collapse
Affiliation(s)
- Alberto Danese
- Department of Medical Sciences, Laboratory for Technologies of Advanced Therapies, University of Ferrara, 44121 Ferrara, Italy
| | - Sara Leo
- Department of Medical Sciences, Laboratory for Technologies of Advanced Therapies, University of Ferrara, 44121 Ferrara, Italy
| | - Alessandro Rimessi
- Department of Medical Sciences, Laboratory for Technologies of Advanced Therapies, University of Ferrara, 44121 Ferrara, Italy
| | - Mariusz R Wieckowski
- Laboratory of Mitochondrial Biology and Metabolism, Nencki Institute of Experimental Biology, Pasteur 3 Str., 02-093 Warsaw, Poland
| | | | - Carlotta Giorgi
- Department of Medical Sciences, Laboratory for Technologies of Advanced Therapies, University of Ferrara, 44121 Ferrara, Italy.
| | - Paolo Pinton
- Department of Medical Sciences, Laboratory for Technologies of Advanced Therapies, University of Ferrara, 44121 Ferrara, Italy.
| |
Collapse
|
57
|
Malek M, Wawrzyniak AM, Koch P, Lüchtenborg C, Hessenberger M, Sachsenheimer T, Jang W, Brügger B, Haucke V. Inositol triphosphate-triggered calcium release blocks lipid exchange at endoplasmic reticulum-Golgi contact sites. Nat Commun 2021; 12:2673. [PMID: 33976123 PMCID: PMC8113574 DOI: 10.1038/s41467-021-22882-x] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Accepted: 04/02/2021] [Indexed: 02/03/2023] Open
Abstract
Vesicular traffic and membrane contact sites between organelles enable the exchange of proteins, lipids, and metabolites. Recruitment of tethers to contact sites between the endoplasmic reticulum (ER) and the plasma membrane is often triggered by calcium. Here we reveal a function for calcium in the repression of cholesterol export at membrane contact sites between the ER and the Golgi complex. We show that calcium efflux from ER stores induced by inositol-triphosphate [IP3] accumulation upon loss of the inositol 5-phosphatase INPP5A or receptor signaling triggers depletion of cholesterol and associated Gb3 from the cell surface, resulting in a blockade of clathrin-independent endocytosis (CIE) of Shiga toxin. This phenotype is caused by the calcium-induced dissociation of oxysterol binding protein (OSBP) from the Golgi complex and from VAP-containing membrane contact sites. Our findings reveal a crucial function for INPP5A-mediated IP3 hydrolysis in the control of lipid exchange at membrane contact sites.
Collapse
Affiliation(s)
- Mouhannad Malek
- grid.418832.40000 0001 0610 524XLeibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Berlin, Germany
| | - Anna M. Wawrzyniak
- grid.418832.40000 0001 0610 524XLeibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Berlin, Germany
| | - Peter Koch
- grid.418832.40000 0001 0610 524XLeibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Berlin, Germany
| | - Christian Lüchtenborg
- grid.7700.00000 0001 2190 4373Heidelberg University Biochemistry Center (BZH), Heidelberg University, Heidelberg, Germany
| | - Manuel Hessenberger
- grid.418832.40000 0001 0610 524XLeibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Berlin, Germany
| | - Timo Sachsenheimer
- grid.7700.00000 0001 2190 4373Heidelberg University Biochemistry Center (BZH), Heidelberg University, Heidelberg, Germany
| | - Wonyul Jang
- grid.418832.40000 0001 0610 524XLeibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Berlin, Germany
| | - Britta Brügger
- grid.7700.00000 0001 2190 4373Heidelberg University Biochemistry Center (BZH), Heidelberg University, Heidelberg, Germany
| | - Volker Haucke
- grid.418832.40000 0001 0610 524XLeibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Berlin, Germany ,grid.14095.390000 0000 9116 4836Faculty of Biology, Chemistry and Pharmacy, Freie Universität Berlin, Berlin, Germany
| |
Collapse
|
58
|
Zhang SS, Zhou S, Crowley-McHattan ZJ, Wang RY, Li JP. A Review of the Role of Endo/Sarcoplasmic Reticulum-Mitochondria Ca 2+ Transport in Diseases and Skeletal Muscle Function. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:ijerph18083874. [PMID: 33917091 PMCID: PMC8067840 DOI: 10.3390/ijerph18083874] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/21/2021] [Revised: 03/23/2021] [Accepted: 03/24/2021] [Indexed: 02/07/2023]
Abstract
The physical contact site between a mitochondrion and endoplasmic reticulum (ER), named the mitochondria-associated membrane (MAM), has emerged as a fundamental platform for regulating the functions of the two organelles and several cellular processes. This includes Ca2+ transport from the ER to mitochondria, mitochondrial dynamics, autophagy, apoptosis signalling, ER stress signalling, redox reaction, and membrane structure maintenance. Consequently, the MAM is suggested to be involved in, and as a possible therapeutic target for, some common diseases and impairment in skeletal muscle function, such as insulin resistance and diabetes, obesity, neurodegenerative diseases, Duchenne muscular dystrophy, age-related muscle atrophy, and exercise-induced muscle damage. In the past decade, evidence suggests that alterations in Ca2+ transport from the ER to mitochondria, mediated by the macromolecular complex formed by IP3R, Grp75, and VDAC1, may be a universal mechanism for how ER-mitochondria cross-talk is involved in different physiological/pathological conditions mentioned above. A better understanding of the ER (or sarcoplasmic reticulum in muscle)-mitochondria Ca2+ transport system may provide a new perspective for exploring the mechanism of how the MAM is involved in the pathology of diseases and skeletal muscle dysfunction. This review provides a summary of recent research findings in this area.
Collapse
Affiliation(s)
- Shuang-Shuang Zhang
- School of Sport Science, Beijing Sport University, Beijing 100084, China; (S.-S.Z.); (J.-P.L.)
- Faculty of Health, Southern Cross University, East Lismore, NSW 2480, Australia; (S.Z.); (Z.J.C.-M.)
| | - Shi Zhou
- Faculty of Health, Southern Cross University, East Lismore, NSW 2480, Australia; (S.Z.); (Z.J.C.-M.)
| | | | - Rui-Yuan Wang
- School of Sport Science, Beijing Sport University, Beijing 100084, China; (S.-S.Z.); (J.-P.L.)
- Correspondence:
| | - Jun-Ping Li
- School of Sport Science, Beijing Sport University, Beijing 100084, China; (S.-S.Z.); (J.-P.L.)
| |
Collapse
|
59
|
Wang N, Wang C, Zhao H, He Y, Lan B, Sun L, Gao Y. The MAMs Structure and Its Role in Cell Death. Cells 2021; 10:cells10030657. [PMID: 33809551 PMCID: PMC7999768 DOI: 10.3390/cells10030657] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 03/09/2021] [Accepted: 03/11/2021] [Indexed: 02/06/2023] Open
Abstract
The maintenance of cellular homeostasis involves the participation of multiple organelles. These organelles are associated in space and time, and either cooperate or antagonize each other with regards to cell function. Crosstalk between organelles has become a significant topic in research over recent decades. We believe that signal transduction between organelles, especially the endoplasmic reticulum (ER) and mitochondria, is a factor that can influence the cell fate. As the cellular center for protein folding and modification, the endoplasmic reticulum can influence a range of physiological processes by regulating the quantity and quality of proteins. Mitochondria, as the cellular "energy factory," are also involved in cell death processes. Some researchers regard the ER as the sensor of cellular stress and the mitochondria as an important actuator of the stress response. The scientific community now believe that bidirectional communication between the ER and the mitochondria can influence cell death. Recent studies revealed that the death signals can shuttle between the two organelles. Mitochondria-associated membranes (MAMs) play a vital role in the complex crosstalk between the ER and mitochondria. MAMs are known to play an important role in lipid synthesis, the regulation of Ca2+ homeostasis, the coordination of ER-mitochondrial function, and the transduction of death signals between the ER and the mitochondria. Clarifying the structure and function of MAMs will provide new concepts for studying the pathological mechanisms associated with neurodegenerative diseases, aging, and cancers. Here, we review the recent studies of the structure and function of MAMs and its roles involved in cell death, especially in apoptosis.
Collapse
Affiliation(s)
- Nan Wang
- China Japan Union Hospital, Jilin University, Changchun 130031, China; (N.W.); (C.W.); (H.Z.); (Y.H.); (B.L.)
| | - Chong Wang
- China Japan Union Hospital, Jilin University, Changchun 130031, China; (N.W.); (C.W.); (H.Z.); (Y.H.); (B.L.)
| | - Hongyang Zhao
- China Japan Union Hospital, Jilin University, Changchun 130031, China; (N.W.); (C.W.); (H.Z.); (Y.H.); (B.L.)
| | - Yichun He
- China Japan Union Hospital, Jilin University, Changchun 130031, China; (N.W.); (C.W.); (H.Z.); (Y.H.); (B.L.)
| | - Beiwu Lan
- China Japan Union Hospital, Jilin University, Changchun 130031, China; (N.W.); (C.W.); (H.Z.); (Y.H.); (B.L.)
| | - Liankun Sun
- Key Laboratory of Pathobiology, Ministry of Education, Department of Pathophysiology, College of Basic Medical Sciences, Jilin University, Changchun 130012, China
- Correspondence: (L.S.); (Y.G.)
| | - Yufei Gao
- China Japan Union Hospital, Jilin University, Changchun 130031, China; (N.W.); (C.W.); (H.Z.); (Y.H.); (B.L.)
- Correspondence: (L.S.); (Y.G.)
| |
Collapse
|
60
|
Balancing ER-Mitochondrial Ca 2+ Fluxes in Health and Disease. Trends Cell Biol 2021; 31:598-612. [PMID: 33678551 DOI: 10.1016/j.tcb.2021.02.003] [Citation(s) in RCA: 60] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Revised: 01/29/2021] [Accepted: 02/02/2021] [Indexed: 02/08/2023]
Abstract
Organelles cooperate with each other to control cellular homeostasis and cell functions by forming close connections through membrane contact sites. Important contacts are present between the endoplasmic reticulum (ER), the main intracellular Ca2+-storage organelle, and the mitochondria, the organelle responsible not only for the majority of cellular ATP production but also for switching on cell death processes. Several Ca2+-transport systems focalize at these contact sites, thereby enabling the efficient transmission of Ca2+ signals from the ER toward mitochondria. This provides tight control of mitochondrial functions at the microdomain level. Here, we discuss how ER-mitochondrial Ca2+ transfers support cell function and how their dysregulation underlies, drives, or contributes to pathogenesis and pathophysiology, with a major focus on cancer and neurodegeneration but also with attention to other diseases such as diabetes and rare genetic diseases.
Collapse
|
61
|
Madreiter-Sokolowski CT, Gottschalk B, Sokolowski AA, Malli R, Graier WF. Dynamic Control of Mitochondrial Ca 2+ Levels as a Survival Strategy of Cancer Cells. Front Cell Dev Biol 2021; 9:614668. [PMID: 33614647 PMCID: PMC7889948 DOI: 10.3389/fcell.2021.614668] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Accepted: 01/14/2021] [Indexed: 12/14/2022] Open
Abstract
Cancer cells have increased energy requirements due to their enhanced proliferation activity. This energy demand is, among others, met by mitochondrial ATP production. Since the second messenger Ca2+ maintains the activity of Krebs cycle dehydrogenases that fuel mitochondrial respiration, proper mitochondrial Ca2+ uptake is crucial for a cancer cell survival. However, a mitochondrial Ca2+ overload induces mitochondrial dysfunction and, ultimately, apoptotic cell death. Because of the vital importance of balancing mitochondrial Ca2+ levels, a highly sophisticated machinery of multiple proteins manages mitochondrial Ca2+ homeostasis. Notably, mitochondria sequester Ca2+ preferentially at the interaction sites between mitochondria and the endoplasmic reticulum (ER), the largest internal Ca2+ store, thus, pointing to mitochondrial-associated membranes (MAMs) as crucial hubs between cancer prosperity and cell death. To investigate potential regulatory mechanisms of the mitochondrial Ca2+ uptake routes in cancer cells, we modulated mitochondria–ER tethering and the expression of UCP2 and analyzed mitochondrial Ca2+ homeostasis under the various conditions. Hence, the expression of contributors to mitochondrial Ca2+ regulation machinery was quantified by qRT-PCR. We further used data from The Cancer Genome Atlas (TCGA) to correlate these in vitro findings with expression patterns in human breast invasive cancer and human prostate adenocarcinoma. ER-mitochondrial linkage was found to support a mitochondrial Ca2+ uptake route dependent on uncoupling protein 2 (UCP2) in cancer cells. Notably, combined overexpression of Rab32, a protein kinase A-anchoring protein fostering the ER-mitochondrial tethering, and UCP2 caused a significant drop in cancer cells' viability. Artificially enhanced ER-mitochondrial tethering further initiated a sudden decline in the expression of UCP2, probably as an adaptive response to avoid mitochondrial Ca2+ overload. Besides, TCGA analysis revealed an inverse expression correlation between proteins stabilizing mitochondrial-ER linkage and UCP2 in tissues of human breast invasive cancer and prostate adenocarcinoma. Based on these results, we assume that cancer cells successfully manage mitochondrial Ca2+ uptake to stimulate Ca2+-dependent mitochondrial metabolism while avoiding Ca2+-triggered cell death by fine-tuning ER-mitochondrial tethering and the expression of UCP2 in an inversed manner. Disruption of this equilibrium yields cancer cell death and may serve as a treatment strategy to specifically kill cancer cells.
Collapse
Affiliation(s)
- Corina T Madreiter-Sokolowski
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria.,Department of Health Sciences and Technology, ETH Zurich, Schwerzenbach, Switzerland
| | - Benjamin Gottschalk
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria
| | - Armin A Sokolowski
- Department of Dental Medicine and Oral Health, Medical University of Graz, Graz, Austria
| | - 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
| |
Collapse
|
62
|
Márta K, Hasan P, Rodríguez-Prados M, Paillard M, Hajnóczky G. Pharmacological inhibition of the mitochondrial Ca 2+ uniporter: Relevance for pathophysiology and human therapy. J Mol Cell Cardiol 2021; 151:135-144. [PMID: 33035551 PMCID: PMC7880870 DOI: 10.1016/j.yjmcc.2020.09.014] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Revised: 09/26/2020] [Accepted: 09/28/2020] [Indexed: 12/20/2022]
Abstract
Mitochondrial Ca2+ uptake has long been considered crucial for meeting the fluctuating energy demands of cells in the heart and other tissues. Increases in mitochondrial matrix [Ca2+] drive mitochondrial ATP production via stimulation of Ca2+-sensitive dehydrogenases. Mitochondria-targeted sensors have revealed mitochondrial matrix [Ca2+] rises that closely follow the cytoplasmic [Ca2+] signals in many paradigms. Mitochondrial Ca2+ uptake is mediated by the Ca2+ uniporter (mtCU). Pharmacological manipulation of the mtCU is potentially key to understanding its physiological significance, but no specific, cell-permeable inhibitors were identified. In the past decade, as the molecular identity of the mtCU was brought to light, efforts have focused on genetic targeting. However, in the cells/animals that are able to survive impaired mtCU function, robust compensatory changes were found in the mtCU as well as other mechanisms. Thus, the discovery, through chemical library screens on normal and mtCU-deficient cells, of new small-molecule inhibitors with improved cell permeability and specificity might offer a better chance to test the relevance of mitochondrial Ca2+ uptake. Success with the development of small molecule mtCU inhibitors is also expected to have clinical impact, considering the growing evidence for the role of mitochondrial Ca2+ uptake in a variety of diseases, including heart attack, stroke and various neurodegenerative disorders. Here, we review the progress in pharmacological targeting of mtCU and illustrate the challenges in this field using data obtained with MCU-i11, a new small molecule inhibitor.
Collapse
Affiliation(s)
- Katalin Márta
- MitoCare Center, Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Prottoy Hasan
- MitoCare Center, Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Macarena Rodríguez-Prados
- MitoCare Center, Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Melanie Paillard
- MitoCare Center, Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA; Univ-Lyon, CarMeN Laboratory, INSERM, INRA, Université Claude Bernard Lyon-1, INSA-Lyon, HCL, 69500 Bron, France
| | - György Hajnóczky
- MitoCare Center, Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA.
| |
Collapse
|
63
|
Rossi A, Galla L, Gomiero C, Zentilin L, Giacca M, Giorgio V, Calì T, Pozzan T, Greotti E, Pizzo P. Calcium Signaling and Mitochondrial Function in Presenilin 2 Knock-Out Mice: Looking for Any Loss-of-Function Phenotype Related to Alzheimer's Disease. Cells 2021; 10:204. [PMID: 33494218 PMCID: PMC7909802 DOI: 10.3390/cells10020204] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 01/17/2021] [Accepted: 01/18/2021] [Indexed: 02/07/2023] Open
Abstract
Alzheimer's disease (AD) is the most common age-related neurodegenerative disorder in which learning, memory and cognitive functions decline progressively. Familial forms of AD (FAD) are caused by mutations in amyloid precursor protein (APP), presenilin 1 (PSEN1) and presenilin 2 (PSEN2) genes. Presenilin 1 (PS1) and its homologue, presenilin 2 (PS2), represent, alternatively, the catalytic core of the γ-secretase complex that, by cleaving APP, produces neurotoxic amyloid beta (Aβ) peptides responsible for one of the histopathological hallmarks in AD brains, the amyloid plaques. Recently, PSEN1 FAD mutations have been associated with a loss-of-function phenotype. To investigate whether this finding can also be extended to PSEN2 FAD mutations, we studied two processes known to be modulated by PS2 and altered by FAD mutations: Ca2+ signaling and mitochondrial function. By exploiting neurons derived from a PSEN2 knock-out (PS2-/-) mouse model, we found that, upon IP3-generating stimulation, cytosolic Ca2+ handling is not altered, compared to wild-type cells, while mitochondrial Ca2+ uptake is strongly compromised. Accordingly, PS2-/- neurons show a marked reduction in endoplasmic reticulum-mitochondria apposition and a slight alteration in mitochondrial respiration, whereas mitochondrial membrane potential, and organelle morphology and number appear unchanged. Thus, although some alterations in mitochondrial function appear to be shared between PS2-/- and FAD-PS2-expressing neurons, the mechanisms leading to these defects are quite distinct between the two models. Taken together, our data appear to be difficult to reconcile with the proposal that FAD-PS2 mutants are loss-of-function, whereas the concept that PS2 plays a key role in sustaining mitochondrial function is here confirmed.
Collapse
Affiliation(s)
- Alice Rossi
- Department of Biomedical Sciences, University of Padua, 35131 Padua, Italy; (A.R.); (L.G.); (C.G.); (V.G.); (T.C.); (T.P.); (P.P.)
| | - Luisa Galla
- Department of Biomedical Sciences, University of Padua, 35131 Padua, Italy; (A.R.); (L.G.); (C.G.); (V.G.); (T.C.); (T.P.); (P.P.)
- Neuroscience Institute, National Research Council (CNR), 35131 Padua, Italy
| | - Chiara Gomiero
- Department of Biomedical Sciences, University of Padua, 35131 Padua, Italy; (A.R.); (L.G.); (C.G.); (V.G.); (T.C.); (T.P.); (P.P.)
- Neuroscience Institute, National Research Council (CNR), 35131 Padua, Italy
| | - Lorena Zentilin
- International Centre for Genetic Engineering and Biotechnology (ICGEB), 34149 Trieste, Italy; (L.Z.); (M.G.)
| | - Mauro Giacca
- International Centre for Genetic Engineering and Biotechnology (ICGEB), 34149 Trieste, Italy; (L.Z.); (M.G.)
| | - Valentina Giorgio
- Department of Biomedical Sciences, University of Padua, 35131 Padua, Italy; (A.R.); (L.G.); (C.G.); (V.G.); (T.C.); (T.P.); (P.P.)
- Neuroscience Institute, National Research Council (CNR), 35131 Padua, Italy
- Department of Biomedical and Neuromotor Science, University of Bologna, 40112 Bologna, Italy
| | - Tito Calì
- Department of Biomedical Sciences, University of Padua, 35131 Padua, Italy; (A.R.); (L.G.); (C.G.); (V.G.); (T.C.); (T.P.); (P.P.)
| | - Tullio Pozzan
- Department of Biomedical Sciences, University of Padua, 35131 Padua, Italy; (A.R.); (L.G.); (C.G.); (V.G.); (T.C.); (T.P.); (P.P.)
- Neuroscience Institute, National Research Council (CNR), 35131 Padua, Italy
- Venetian Institute of Molecular Medicine (VIMM), 35131 Padua, Italy
| | - Elisa Greotti
- Department of Biomedical Sciences, University of Padua, 35131 Padua, Italy; (A.R.); (L.G.); (C.G.); (V.G.); (T.C.); (T.P.); (P.P.)
- Neuroscience Institute, National Research Council (CNR), 35131 Padua, Italy
| | - Paola Pizzo
- Department of Biomedical Sciences, University of Padua, 35131 Padua, Italy; (A.R.); (L.G.); (C.G.); (V.G.); (T.C.); (T.P.); (P.P.)
- Neuroscience Institute, National Research Council (CNR), 35131 Padua, Italy
| |
Collapse
|
64
|
Miranda-Silva D, Lima T, Rodrigues P, Leite-Moreira A, Falcão-Pires I. Mechanisms underlying the pathophysiology of heart failure with preserved ejection fraction: the tip of the iceberg. Heart Fail Rev 2021; 26:453-478. [PMID: 33411091 DOI: 10.1007/s10741-020-10042-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 10/15/2020] [Indexed: 12/18/2022]
Abstract
Heart failure with preserved ejection fraction (HFpEF) is a multifaceted syndrome with a complex aetiology often associated with several comorbidities, such as left ventricle pressure overload, diabetes mellitus, obesity, and kidney disease. Its pathophysiology remains obscure mainly due to the complex phenotype induced by all these associated comorbidities and to the scarcity of animal models that adequately mimic HFpEF. Increased oxidative stress, inflammation, and endothelial dysfunction are currently accepted as key players in HFpEF pathophysiology. However, we have just started to unveil HFpEF complexity and the role of calcium handling, energetic metabolism, and mitochondrial function remain to clarify. Indeed, the enlightenment of such cellular and molecular mechanisms represents an opportunity to develop novel therapeutic approaches and thus to improve HFpEF treatment options. In the last decades, the number of research groups dedicated to studying HFpEF has increased, denoting the importance and the magnitude achieved by this syndrome. In the current technological and web world, the amount of information is overwhelming, driving us not only to compile the most relevant information about the theme but also to explore beyond the tip of the iceberg. Thus, this review aims to encompass the most recent knowledge related to HFpEF or HFpEF-associated comorbidities, focusing mainly on myocardial metabolism, oxidative stress, and energetic pathways.
Collapse
Affiliation(s)
- Daniela Miranda-Silva
- Department of Surgery and Physiology, Faculty of Medicine, University of Porto, Porto, Portugal.
| | - Tânia Lima
- Department of Surgery and Physiology, Faculty of Medicine, University of Porto, Porto, Portugal
| | - Patrícia Rodrigues
- Department of Surgery and Physiology, Faculty of Medicine, University of Porto, Porto, Portugal
| | - Adelino Leite-Moreira
- Department of Surgery and Physiology, Faculty of Medicine, University of Porto, Porto, Portugal
| | - Inês Falcão-Pires
- Department of Surgery and Physiology, Faculty of Medicine, University of Porto, Porto, Portugal
| |
Collapse
|
65
|
Parys JB, Bultynck G, Vervliet T. IP 3 Receptor Biology and Endoplasmic Reticulum Calcium Dynamics in Cancer. PROGRESS IN MOLECULAR AND SUBCELLULAR BIOLOGY 2021; 59:215-237. [PMID: 34050869 DOI: 10.1007/978-3-030-67696-4_11] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Intracellular Ca2+ signaling regulates a plethora of cellular functions. A central role in these processes is reserved for the inositol 1,4,5-trisphosphate receptor (IP3R), a ubiquitously expressed Ca2+-release channel, mainly located in the endoplasmic reticulum (ER). Three IP3R isoforms (IP3R1, IP3R2 and IP3R3) exist, encoded respectively by ITPR1, ITPR2 and ITPR3. The proteins encoded by these genes are each about 2700 amino acids long and assemble into large tetrameric channels, which form the target of many regulatory proteins, including several tumor suppressors and oncogenes. Due to the important role of the IP3Rs in cell function, their dysregulation is linked to multiple pathologies. In this review, we highlight the complex role of the IP3R in cancer, as it participates in most of the so-called "hallmarks of cancer". In particular, the IP3R directly controls cell death and cell survival decisions via regulation of autophagy and apoptosis. Moreover, the IP3R impacts cellular proliferation, migration and invasion. Typical examples of the role of the IP3Rs in these various processes are discussed. The relative levels of the IP3R isoforms expressed and their subcellular localization, e.g. at the ER-mitochondrial interface, is hereby important. Finally, evidence is provided about how the knowledge of the regulation of the IP3R by tumor suppressors and oncogenes can be exploited to develop novel therapeutic approaches to fight cancer.
Collapse
Affiliation(s)
- Jan B Parys
- Laboratory for Molecular and Cellular Signaling, Department of Cellular and Molecular Medicine & Leuven Cancer Institute, KU Leuven, Leuven, Belgium.
| | - Geert Bultynck
- Laboratory for Molecular and Cellular Signaling, Department of Cellular and Molecular Medicine & Leuven Cancer Institute, KU Leuven, Leuven, Belgium
| | - Tim Vervliet
- Laboratory for Molecular and Cellular Signaling, Department of Cellular and Molecular Medicine & Leuven Cancer Institute, KU Leuven, Leuven, Belgium
| |
Collapse
|
66
|
Inflammation-Induced Protein Unfolding in Airway Smooth Muscle Triggers a Homeostatic Response in Mitochondria. Int J Mol Sci 2020; 22:ijms22010363. [PMID: 33396378 PMCID: PMC7795579 DOI: 10.3390/ijms22010363] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 12/17/2020] [Accepted: 12/28/2020] [Indexed: 12/11/2022] Open
Abstract
The effects of airway inflammation on airway smooth muscle (ASM) are mediated by pro-inflammatory cytokines such as tumor necrosis factor alpha (TNFα). In this review article, we will provide a unifying hypothesis for a homeostatic response to airway inflammation that mitigates oxidative stress and thereby provides resilience to ASM. Previous studies have shown that acute exposure to TNFα increases ASM force generation in response to muscarinic stimulation (hyper-reactivity) resulting in increased ATP consumption and increased tension cost. To meet this increased energetic demand, mitochondrial O2 consumption and oxidative phosphorylation increases but at the cost of increased reactive oxygen species (ROS) production (oxidative stress). TNFα-induced oxidative stress results in the accumulation of unfolded proteins in the endoplasmic reticulum (ER) and mitochondria of ASM. In the ER, TNFα selectively phosphorylates inositol-requiring enzyme 1 alpha (pIRE1α) triggering downstream splicing of the transcription factor X-box binding protein 1 (XBP1s); thus, activating the pIRE1α/XBP1s ER stress pathway. Protein unfolding in mitochondria also triggers an unfolded protein response (mtUPR). In our conceptual framework, we hypothesize that activation of these pathways is homeostatically directed towards mitochondrial remodeling via an increase in peroxisome proliferator-activated receptor-gamma coactivator 1 alpha (PGC1α) expression, which in turn triggers: (1) mitochondrial fragmentation (increased dynamin-related protein-1 (Drp1) and reduced mitofusin-2 (Mfn2) expression) and mitophagy (activation of the Phosphatase and tensin homolog (PTEN)-induced putative kinase 1 (PINK1)/Parkin mitophagy pathway) to improve mitochondrial quality; (2) reduced Mfn2 also results in a disruption of mitochondrial tethering to the ER and reduced mitochondrial Ca2+ influx; and (3) mitochondrial biogenesis and increased mitochondrial volume density. The homeostatic remodeling of mitochondria results in more efficient O2 consumption and oxidative phosphorylation and reduced ROS formation by individual mitochondrion, while still meeting the increased ATP demand. Thus, the energetic load of hyper-reactivity is shared across the mitochondrial pool within ASM cells.
Collapse
|
67
|
Filadi R, Greotti E. The yin and yang of mitochondrial Ca 2+ signaling in cell physiology and pathology. Cell Calcium 2020; 93:102321. [PMID: 33310302 DOI: 10.1016/j.ceca.2020.102321] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 11/16/2020] [Accepted: 11/16/2020] [Indexed: 12/26/2022]
Abstract
Mitochondria are autonomous and dynamic cellular organelles orchestrating a diverse range of cellular activities. Numerous cell-signaling pathways target these organelles and Ca2+ is one of the most significant. Mitochondria are able to rapidly and transiently take up Ca2+, thanks to the mitochondrial Ca2+ uniporter complex, as well as to extrude it through the Na+/Ca2+ and H+/Ca2+ exchangers. The transient accumulation of Ca2+ in the mitochondrial matrix impacts on mitochondrial functions and cell pathophysiology. Here we summarize the role of mitochondrial Ca2+ signaling in both physiological (yang) and pathological (yin) processes and the methods that can be used to investigate mitochondrial Ca2+ homeostasis. As an example of the pivotal role of mitochondria in pathology, we described the state of the art of mitochondrial Ca2+ alterations in different pathological conditions, with a special focus on Alzheimer's disease.
Collapse
Affiliation(s)
- Riccardo Filadi
- Neuroscience Institute, National Research Council (CNR), 35131 Padua, Italy; Department of Biomedical Sciences, University of Padua, 35131, Padua, Italy.
| | - Elisa Greotti
- Neuroscience Institute, National Research Council (CNR), 35131 Padua, Italy; Department of Biomedical Sciences, University of Padua, 35131, Padua, Italy.
| |
Collapse
|
68
|
Feno S, Rizzuto R, Raffaello A, Vecellio Reane D. The molecular complexity of the Mitochondrial Calcium Uniporter. Cell Calcium 2020; 93:102322. [PMID: 33264708 DOI: 10.1016/j.ceca.2020.102322] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 11/19/2020] [Accepted: 11/19/2020] [Indexed: 12/20/2022]
Abstract
The role of mitochondria in regulating cellular Ca2+ homeostasis is crucial for the understanding of different cellular functions in physiological and pathological conditions. Nevertheless, the study of this aspect was severely limited by the lack of the molecular identity of the proteins responsible for mitochondrial Ca2+ uptake. In 2011, the discovery of the gene encoding for the Mitochondrial Calcium Uniporter (MCU), the selective channel responsible for mitochondrial Ca2+ uptake, gave rise to an explosion of studies aimed to characterize the composition, the regulation of the channel and its pathophysiological roles. Here, we summarize the recent discoveries on the molecular structure and composition of the MCU complex by providing new insights into the mechanisms that regulate MCU channel activity.
Collapse
Affiliation(s)
- Simona Feno
- Department of Biomedical Science, University of Padua, via G. Colombo 3, 35100 Padua, Italy
| | - Rosario Rizzuto
- Department of Biomedical Science, University of Padua, via G. Colombo 3, 35100 Padua, Italy
| | - Anna Raffaello
- Department of Biomedical Science, University of Padua, via G. Colombo 3, 35100 Padua, Italy; Myology Center, University of Padua, via G. Colombo 3, 35100 Padova, Italy.
| | - Denis Vecellio Reane
- Department of Biomedical Science, University of Padua, via G. Colombo 3, 35100 Padua, Italy.
| |
Collapse
|
69
|
Light-Regulated Transcription of a Mitochondrial-Targeted K + Channel. Cells 2020; 9:cells9112507. [PMID: 33228123 PMCID: PMC7699372 DOI: 10.3390/cells9112507] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 11/15/2020] [Accepted: 11/17/2020] [Indexed: 02/06/2023] Open
Abstract
The inner membranes of mitochondria contain several types of K+ channels, which modulate the membrane potential of the organelle and contribute in this way to cytoprotection and the regulation of cell death. To better study the causal relationship between K+ channel activity and physiological changes, we developed an optogenetic platform for a light-triggered modulation of K+ conductance in mitochondria. By using the light-sensitive interaction between cryptochrome 2 and the regulatory protein CIB1, we can trigger the transcription of a small and highly selective K+ channel, which is in mammalian cells targeted into the inner membrane of mitochondria. After exposing cells to very low intensities (≤0.16 mW/mm2) of blue light, the channel protein is detectable as an accumulation of its green fluorescent protein (GFP) tag in the mitochondria less than 1 h after stimulation. This system allows for an in vivo monitoring of crucial physiological parameters of mitochondria, showing that the presence of an active K+ channel causes a substantial depolarization compatible with the effect of an uncoupler. Elevated K+ conductance also results in a decrease in the Ca2+ concentration in the mitochondria but has no impact on apoptosis.
Collapse
|
70
|
Koshenov Z, Oflaz FE, Hirtl M, Bachkoenig OA, Rost R, Osibow K, Gottschalk B, Madreiter-Sokolowski CT, Waldeck-Weiermair M, Malli R, Graier WF. The contribution of uncoupling protein 2 to mitochondrial Ca 2+ homeostasis in health and disease - A short revisit. Mitochondrion 2020; 55:164-173. [PMID: 33069910 DOI: 10.1016/j.mito.2020.10.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Revised: 09/30/2020] [Accepted: 10/12/2020] [Indexed: 12/18/2022]
Abstract
Considering the versatile functions attributed to uncoupling protein 2 (UCP2) in health and disease, a profound understanding of the protein's molecular actions under physiological and pathophysiological conditions is indispensable. This review aims to revisit and shed light on the fundamental molecular functions of UCP2 in mitochondria, with particular emphasis on its intricate role in regulating mitochondrial calcium (Ca2+) uptake. UCP2's modulating effect on various vital processes in mitochondria makes it a crucial regulator of mitochondrial homeostasis in health and disease.
Collapse
Affiliation(s)
- Zhanat Koshenov
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
| | - Furkan E Oflaz
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
| | - Martin Hirtl
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
| | - Olaf A Bachkoenig
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
| | - Rene Rost
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
| | - Karin Osibow
- Diagnostic and Research Institute for Pathology, Medical University of Graz, Neue Stiftingtalstraße 6, 8010 Graz, Austria; Department of Health Sciences and Technology, ETH Zurich, Schorenstraße 16, 8603 Schwerzenbach, Switzerland
| | - Benjamin Gottschalk
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
| | - Corina T Madreiter-Sokolowski
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria; Diagnostic and Research Institute for Pathology, Medical University of Graz, Neue Stiftingtalstraße 6, 8010 Graz, Austria
| | - Markus Waldeck-Weiermair
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria; Division of Cardiovascular Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA 02115, USA
| | - Roland Malli
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria; BioTechMed, Graz, Austria
| | - Wolfgang F Graier
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria; BioTechMed, Graz, Austria.
| |
Collapse
|
71
|
Atakpa-Adaji P, Thillaiappan NB, Taylor CW. IP3 receptors and their intimate liaisons. CURRENT OPINION IN PHYSIOLOGY 2020. [DOI: 10.1016/j.cophys.2020.06.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
|
72
|
Filadi R, Pizzo P. Mitochondrial calcium handling and neurodegeneration: when a good signal goes wrong. CURRENT OPINION IN PHYSIOLOGY 2020. [DOI: 10.1016/j.cophys.2020.08.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
|
73
|
|
74
|
Vecellio Reane D, Rizzuto R, Raffaello A. The ER-mitochondria tether at the hub of Ca2+ signaling. CURRENT OPINION IN PHYSIOLOGY 2020. [DOI: 10.1016/j.cophys.2020.08.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
|
75
|
Zampese E, Surmeier DJ. Calcium, Bioenergetics, and Parkinson's Disease. Cells 2020; 9:cells9092045. [PMID: 32911641 PMCID: PMC7564460 DOI: 10.3390/cells9092045] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 09/04/2020] [Accepted: 09/07/2020] [Indexed: 12/12/2022] Open
Abstract
Degeneration of substantia nigra (SN) dopaminergic (DAergic) neurons is responsible for the core motor deficits of Parkinson’s disease (PD). These neurons are autonomous pacemakers that have large cytosolic Ca2+ oscillations that have been linked to basal mitochondrial oxidant stress and turnover. This review explores the origin of Ca2+ oscillations and their role in the control of mitochondrial respiration, bioenergetics, and mitochondrial oxidant stress.
Collapse
|
76
|
Brown JA, Sammy MJ, Ballinger SW. An evolutionary, or "Mitocentric" perspective on cellular function and disease. Redox Biol 2020; 36:101568. [PMID: 32512469 PMCID: PMC7281786 DOI: 10.1016/j.redox.2020.101568] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 05/01/2020] [Accepted: 05/05/2020] [Indexed: 12/11/2022] Open
Abstract
The incidence of common, metabolic diseases (e.g. obesity, cardiovascular disease, diabetes) with complex genetic etiology has been steadily increasing nationally and globally. While identification of a genetic model that explains susceptibility and risk for these diseases has been pursued over several decades, no clear paradigm has yet been found to disentangle the genetic basis of polygenic/complex disease development. Since the evolution of the eukaryotic cell involved a symbiotic interaction between the antecedents of the mitochondrion and nucleus (which itself is a genetic hybrid), we suggest that this history provides a rational basis for investigating whether genetic interaction and co-evolution of these genomes still exists. We propose that both mitochondrial and Mendelian, or "mito-Mendelian" genetics play a significant role in cell function, and thus disease risk. This paradigm contemplates the natural variation and co-evolution of both mitochondrial and nuclear DNA backgrounds on multiple mitochondrial functions that are discussed herein, including energy production, cell signaling and immune response, which collectively can influence disease development. At the nexus of these processes is the economy of mitochondrial metabolism, programmed by both mitochondrial and nuclear genomes.
Collapse
Affiliation(s)
- Jamelle A Brown
- Department of Pathology, Division of Molecular and Cellular Pathology, University of Alabama at Birmingham, Birmingham, AL, 35294, USA
| | - Melissa J Sammy
- Department of Nutrition Sciences, University of Alabama at Birmingham, Birmingham, AL, 35294, USA
| | - Scott W Ballinger
- Department of Pathology, Division of Molecular and Cellular Pathology, University of Alabama at Birmingham, Birmingham, AL, 35294, USA.
| |
Collapse
|
77
|
Urra H, Pihán P, Hetz C. The UPRosome - decoding novel biological outputs of IRE1α function. J Cell Sci 2020; 133:133/15/jcs218107. [PMID: 32788208 DOI: 10.1242/jcs.218107] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Different perturbations alter the function of the endoplasmic reticulum (ER), resulting in the accumulation of misfolded proteins in its lumen, a condition termed ER stress. To restore ER proteostasis, a highly conserved pathway is engaged, known as the unfolded protein response (UPR), triggering adaptive programs or apoptosis of terminally damaged cells. IRE1α (also known as ERN1), the most conserved UPR sensor, mediates the activation of responses to determine cell fate under ER stress. The complexity of IRE1α regulation and its signaling outputs is mediated in part by the assembly of a dynamic multi-protein complex, named the UPRosome, that regulates IRE1α activity and the crosstalk with other pathways. We discuss several studies identifying components of the UPRosome that have illuminated novel functions in cell death, autophagy, DNA damage, energy metabolism and cytoskeleton dynamics. Here, we provide a theoretical analysis to assess the biological significance of the UPRosome and present the results of a systematic bioinformatics analysis of the available IRE1α interactome data sets followed by functional enrichment clustering. This in silico approach decoded that IRE1α also interacts with proteins involved in the cell cycle, transport, differentiation, response to viral infection and immune response. Thus, defining the spectrum of IRE1α-binding partners will reveal novel signaling outputs and the relevance of the pathway to human diseases.
Collapse
Affiliation(s)
- Hery Urra
- Biomedical Neuroscience Institute (BNI), Faculty of Medicine, University of Chile, Santiago 8380453, Chile .,Center for Geroscience, Brain Health and Metabolism (GERO), Santiago 7800003, Chile.,Program of Cellular and Molecular Biology, Institute of Biomedical Sciences (ICBM), University of Chile, Santiago 8380453, Chile
| | - Philippe Pihán
- Biomedical Neuroscience Institute (BNI), Faculty of Medicine, University of Chile, Santiago 8380453, Chile.,Center for Geroscience, Brain Health and Metabolism (GERO), Santiago 7800003, Chile.,Program of Cellular and Molecular Biology, Institute of Biomedical Sciences (ICBM), University of Chile, Santiago 8380453, Chile
| | - Claudio Hetz
- Biomedical Neuroscience Institute (BNI), Faculty of Medicine, University of Chile, Santiago 8380453, Chile .,Center for Geroscience, Brain Health and Metabolism (GERO), Santiago 7800003, Chile.,Program of Cellular and Molecular Biology, Institute of Biomedical Sciences (ICBM), University of Chile, Santiago 8380453, Chile.,The Buck Institute for Research in Aging, Novato, CA 94945, USA
| |
Collapse
|
78
|
Pleiotropic Mitochondria: The Influence of Mitochondria on Neuronal Development and Disease. J Neurosci 2020; 39:8200-8208. [PMID: 31619488 DOI: 10.1523/jneurosci.1157-19.2019] [Citation(s) in RCA: 119] [Impact Index Per Article: 29.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 08/09/2019] [Accepted: 08/10/2019] [Indexed: 02/08/2023] Open
Abstract
Mitochondria play many important biological roles, including ATP production, lipid biogenesis, ROS regulation, and calcium clearance. In neurons, the mitochondrion is an essential organelle for metabolism and calcium homeostasis. Moreover, mitochondria are extremely dynamic and able to divide, fuse, and move along microtubule tracks to ensure their distribution to the neuronal periphery. Mitochondrial dysfunction and altered mitochondrial dynamics are observed in a wide range of conditions, from impaired neuronal development to various neurodegenerative diseases. Novel imaging techniques and genetic tools provide unprecedented access to the physiological roles of mitochondria by visualizing mitochondrial trafficking, morphological dynamics, ATP generation, and ultrastructure. Recent studies using these new techniques have unveiled the influence of mitochondria on axon branching, synaptic function, calcium regulation with the ER, glial cell function, neurogenesis, and neuronal repair. This review provides an overview of the crucial roles played by mitochondria in the CNS in physiological and pathophysiological conditions.
Collapse
|
79
|
Rossini M, Pizzo P, Filadi R. Better to keep in touch: investigating inter‐organelle cross‐talk. FEBS J 2020; 288:740-755. [DOI: 10.1111/febs.15451] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 05/28/2020] [Accepted: 06/11/2020] [Indexed: 12/14/2022]
Affiliation(s)
- Michela Rossini
- Department of Biomedical Sciences University of Padua Padua Italy
| | - Paola Pizzo
- Department of Biomedical Sciences University of Padua Padua Italy
- Neuroscience Institute National Research Council (CNR) Padua Italy
| | - Riccardo Filadi
- Department of Biomedical Sciences University of Padua Padua Italy
- Neuroscience Institute National Research Council (CNR) Padua Italy
| |
Collapse
|
80
|
Vianello C, Cocetta V, Caicci F, Boldrin F, Montopoli M, Martinuzzi A, Carelli V, Giacomello M. Interaction Between Mitochondrial DNA Variants and Mitochondria/Endoplasmic Reticulum Contact Sites: A Perspective Review. DNA Cell Biol 2020; 39:1431-1443. [PMID: 32598172 DOI: 10.1089/dna.2020.5614] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Mitochondria contain their own genome, mitochondrial DNA (mtDNA), essential to support their fundamental intracellular role in ATP production and other key metabolic and homeostatic pathways. Mitochondria are highly dynamic organelles that communicate with all the other cellular compartments, through sites of high physical proximity. Among all, their crosstalk with the endoplasmic reticulum (ER) appears particularly important as its derangement is tightly implicated with several human disorders. Population-specific mtDNA variants clustered in defining the haplogroups have been shown to exacerbate or mitigate these pathological conditions. The exact mechanisms of the mtDNA background-modifying effect are not completely clear and a possible explanation is the outcome of mitochondrial efficiency on retrograde signaling to the nucleus. However, the possibility that different haplogroups shape the proximity and crosstalk between mitochondria and the ER has never been proposed neither investigated. In this study, we pose and discuss this question and provide preliminary data to answer it. Besides, we also address the possibility that single, disease-causing mtDNA point mutations may act also by reshaping organelle communication. Overall, this perspective review provides a theoretical platform for future studies on the interaction between mtDNA variants and organelle contact sites.
Collapse
Affiliation(s)
| | - Veronica Cocetta
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, Padova, Italy
| | | | | | - Monica Montopoli
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, Padova, Italy.,VIMM-Veneto Institute of Molecular Medicine, Padova, Italy
| | - Andrea Martinuzzi
- Department of Neurorehabilitation, IRCCS "E. Medea" Scientific Institute, Conegliano Research Center, Treviso, Italy
| | - Valerio Carelli
- Department of Biomedical and Neuromotor Sciences (DIBINEM), University of Bologna, Bologna, Italy.,IRCCS Istituto delle Scienze Neurologiche di Bologna, UOC Clinica Neurologica, Bologna, Italy
| | - Marta Giacomello
- Department of Biology, University of Padova, Padova, Italy.,Department of Biomedical Sciences, University of Padova, Padova, Italy
| |
Collapse
|
81
|
Gonzalez-Rodriguez P, Zampese E, Surmeier DJ. Selective neuronal vulnerability in Parkinson's disease. PROGRESS IN BRAIN RESEARCH 2020; 252:61-89. [PMID: 32247375 DOI: 10.1016/bs.pbr.2020.02.005] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Parkinson's disease (PD) is the second most common neurodegenerative disease, disabling millions worldwide. Despite the imperative PD poses, at present, there is no cure or means of slowing progression. This gap is attributable to our incomplete understanding of the factors driving pathogenesis. Research over the past several decades suggests that both cell-autonomous and non-cell autonomous processes contribute to the neuronal dysfunction underlying PD symptoms. The thesis of this review is that an intersection of these processes governs the pattern of pathology in PD. Studies of substantia nigra pars compacta (SNc) dopaminergic neurons, whose loss is responsible for the core motor symptoms of PD, suggest that they have a combination of traits-a long, highly branched axon, autonomous activity, and elevated mitochondrial oxidant stress-that predispose them to non-cell autonomous drivers of pathogenesis, like misfolded forms of alpha-synuclein (α-SYN) and inflammation. The literature surrounding these issues will be briefly summarized, and the translational implications of an intersectional hypothesis of PD pathogenesis discussed.
Collapse
Affiliation(s)
| | - Enrico Zampese
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - D James Surmeier
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States.
| |
Collapse
|
82
|
Sisalli MJ, Feliciello A, Della Notte S, Di Martino R, Borzacchiello D, Annunziato L, Scorziello A. Nuclear-encoded NCX3 and AKAP121: Two novel modulators of mitochondrial calcium efflux in normoxic and hypoxic neurons. Cell Calcium 2020; 87:102193. [PMID: 32193001 DOI: 10.1016/j.ceca.2020.102193] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 03/02/2020] [Accepted: 03/04/2020] [Indexed: 12/30/2022]
Abstract
Mitochondria are highly dynamic organelles extremely important for cell survival. Their structure resembles that of prokaryotic cells since they are composed with two membranes, the inner (IMM) and the outer mitochondrial membrane (OMM) delimitating the intermembrane space (IMS) and the matrix which contains mitochondrial DNA (mtDNA). This structure is strictly related to mitochondrial function since they produce the most of the cellular ATP through the oxidative phosphorylation which generate the electrochemical gradient at the two sides of the inner mitochondrial membrane an essential requirement for mitochondrial function. Cells of highly metabolic demand like those composing muscle, liver and brain, are particularly dependent on mitochondria for their activities. Mitochondria undergo to continual changes in morphology since, they fuse and divide, branch and fragment, swell and extend. Importantly, they move throughout the cell to deliver ATP and other metabolites where they are mostly required. Along with the capability to control energy metabolism, mitochondria play a critical role in the regulation of many physiological processes such as programmed cell death, autophagy, redox signalling, and stem cells reprogramming. All these phenomena are regulated by Ca2+ ions within this organelle. This review will discuss the molecular mechanisms regulating mitochondrial calcium cycling in physiological and pathological conditions with particular regard to their impact on mitochondrial dynamics and function during ischemia. Particular emphasis will be devoted to the role played by NCX3 and AKAP121 as new molecular targets for mitochondrial function and dysfunction.
Collapse
Affiliation(s)
- Maria Josè Sisalli
- Division of Pharmacology, Department of Neuroscience, Reproductive and Dentistry Sciences, School of Medicine, Federico II University of Naples, Italy
| | - Antonio Feliciello
- Department of Molecular Medicine and Medical Biotechnology, Federico II University of Naples, Italy
| | - Salvatore Della Notte
- Division of Pharmacology, Department of Neuroscience, Reproductive and Dentistry Sciences, School of Medicine, Federico II University of Naples, Italy
| | - Rossana Di Martino
- Division of Pharmacology, Department of Neuroscience, Reproductive and Dentistry Sciences, School of Medicine, Federico II University of Naples, Italy
| | - Domenica Borzacchiello
- Department of Molecular Medicine and Medical Biotechnology, Federico II University of Naples, Italy
| | | | - Antonella Scorziello
- Division of Pharmacology, Department of Neuroscience, Reproductive and Dentistry Sciences, School of Medicine, Federico II University of Naples, Italy.
| |
Collapse
|
83
|
Makrecka‐Kuka M, Liepinsh E, Murray AJ, Lemieux H, Dambrova M, Tepp K, Puurand M, Käämbre T, Han WH, Goede P, O'Brien KA, Turan B, Tuncay E, Olgar Y, Rolo AP, Palmeira CM, Boardman NT, Wüst RCI, Larsen TS. Altered mitochondrial metabolism in the insulin-resistant heart. Acta Physiol (Oxf) 2020; 228:e13430. [PMID: 31840389 DOI: 10.1111/apha.13430] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Revised: 12/05/2019] [Accepted: 12/06/2019] [Indexed: 12/12/2022]
Abstract
Obesity-induced insulin resistance and type 2 diabetes mellitus can ultimately result in various complications, including diabetic cardiomyopathy. In this case, cardiac dysfunction is characterized by metabolic disturbances such as impaired glucose oxidation and an increased reliance on fatty acid (FA) oxidation. Mitochondrial dysfunction has often been associated with the altered metabolic function in the diabetic heart, and may result from FA-induced lipotoxicity and uncoupling of oxidative phosphorylation. In this review, we address the metabolic changes in the diabetic heart, focusing on the loss of metabolic flexibility and cardiac mitochondrial function. We consider the alterations observed in mitochondrial substrate utilization, bioenergetics and dynamics, and highlight new areas of research which may improve our understanding of the cause and effect of cardiac mitochondrial dysfunction in diabetes. Finally, we explore how lifestyle (nutrition and exercise) and pharmacological interventions can prevent and treat metabolic and mitochondrial dysfunction in diabetes.
Collapse
Affiliation(s)
| | | | - Andrew J. Murray
- Department of Physiology, Development and Neuroscience University of Cambridge Cambridge UK
| | - Hélène Lemieux
- Department of Medicine Faculty Saint‐Jean, Women and Children's Health Research Institute University of Alberta Edmonton AB Canada
| | | | - Kersti Tepp
- National Institute of Chemical Physics and Biophysics Tallinn Estonia
| | - Marju Puurand
- National Institute of Chemical Physics and Biophysics Tallinn Estonia
| | - Tuuli Käämbre
- National Institute of Chemical Physics and Biophysics Tallinn Estonia
| | - Woo H. Han
- Faculty Saint‐Jean University of Alberta Edmonton AB Canada
| | - Paul Goede
- Laboratory of Endocrinology Amsterdam Gastroenterology & Metabolism Amsterdam University Medical Center University of Amsterdam Amsterdam The Netherlands
| | - Katie A. O'Brien
- Department of Physiology, Development and Neuroscience University of Cambridge Cambridge UK
| | - Belma Turan
- Laboratory of Endocrinology Amsterdam Gastroenterology & Metabolism Amsterdam University Medical Center University of Amsterdam Amsterdam The Netherlands
| | - Erkan Tuncay
- Department of Biophysics Faculty of Medicine Ankara University Ankara Turkey
| | - Yusuf Olgar
- Department of Biophysics Faculty of Medicine Ankara University Ankara Turkey
| | - Anabela P. Rolo
- Department of Life Sciences University of Coimbra and Center for Neurosciences and Cell Biology University of Coimbra Coimbra Portugal
| | - Carlos M. Palmeira
- Department of Life Sciences University of Coimbra and Center for Neurosciences and Cell Biology University of Coimbra Coimbra Portugal
| | - Neoma T. Boardman
- Cardiovascular Research Group Department of Medical Biology UiT the Arctic University of Norway Tromso Norway
| | - Rob C. I. Wüst
- Laboratory for Myology Department of Human Movement Sciences Faculty of Behavioural and Movement Sciences Amsterdam Movement Sciences Vrije Universiteit Amsterdam Amsterdam The Netherlands
| | - Terje S. Larsen
- Cardiovascular Research Group Department of Medical Biology UiT the Arctic University of Norway Tromso Norway
| |
Collapse
|
84
|
Abstract
Owing to their ability to efficiently generate ATP required to sustain normal cell function, mitochondria are often considered the 'powerhouses of the cell'. However, our understanding of the role of mitochondria in cell biology recently expanded when we recognized that they are key platforms for a plethora of cell signalling cascades. This functional versatility is tightly coupled to constant reshaping of the cellular mitochondrial network in a series of processes, collectively referred to as mitochondrial membrane dynamics and involving organelle fusion and fission (division) as well as ultrastructural remodelling of the membrane. Accordingly, mitochondrial dynamics influence and often orchestrate not only metabolism but also complex cell signalling events, such as those involved in regulating cell pluripotency, division, differentiation, senescence and death. Reciprocally, mitochondrial membrane dynamics are extensively regulated by post-translational modifications of its machinery and by the formation of membrane contact sites between mitochondria and other organelles, both of which have the capacity to integrate inputs from various pathways. Here, we discuss mitochondrial membrane dynamics and their regulation and describe how bioenergetics and cellular signalling are linked to these dynamic changes of mitochondrial morphology.
Collapse
|
85
|
Greotti E, Pozzan T. Live Mitochondrial or Cytosolic Calcium Imaging Using Genetically-encoded Cameleon Indicator in Mammalian Cells. Bio Protoc 2020; 10:e3504. [PMID: 33654731 DOI: 10.21769/bioprotoc.3504] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 12/16/2019] [Accepted: 12/17/2019] [Indexed: 02/04/2023] Open
Abstract
Calcium (Ca2+) imaging aims at investigating the dynamic changes in live cells of its concentration ([Ca2+]) in different pathophysiological conditions. Ca2+ is an ubiquitous and versatile intracellular signal that modulates a large variety of cellular functions thanks to a cell type-specific toolkit and a complex subcellular compartmentalization. Many Ca2+ sensors are presently available (chemical and genetically encoded) that can be specifically targeted to different cellular compartments. Using these probes, it is now possible to monitor Ca2+ dynamics of living cells not only in the cytosol but also within specific organelles. The choice of a specific sensor depends on the experimental design and the spatial and temporal resolution required. Here we describe the use of novel Förster resonance energy transfer (FRET)-based fluorescent Ca2+ probes to dynamically and quantitatively monitor the changes in cytosolic and mitochondrial [Ca2+] in a variety of cell types and experimental conditions. FRET-based sensors have the enormous advantage of being ratiometric, a feature that makes them particularly suitable for quantitative and in vivo applications.
Collapse
Affiliation(s)
- Elisa Greotti
- Neuroscience Institute, National Research Council (CNR), 35131 Padua, Italy.,Department of Biomedical Sciences, University of Padua, 35131 Padua, Italy
| | - Tullio Pozzan
- Neuroscience Institute, National Research Council (CNR), 35131 Padua, Italy.,Department of Biomedical Sciences, University of Padua, 35131 Padua, Italy.,Venetian Institute of Molecular Medicine (VIMM), 35129 Padua, Italy
| |
Collapse
|
86
|
Delmotte P, Sieck GC. Endoplasmic Reticulum Stress and Mitochondrial Function in Airway Smooth Muscle. Front Cell Dev Biol 2020; 7:374. [PMID: 32010691 PMCID: PMC6974519 DOI: 10.3389/fcell.2019.00374] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Accepted: 12/16/2019] [Indexed: 12/16/2022] Open
Abstract
Inflammatory airway diseases such as asthma affect more than 300 million people world-wide. Inflammation triggers pathophysiology via such as tumor necrosis factor α (TNFα) and interleukins (e.g., IL-13). Hypercontraction of airway smooth muscle (ASM) and ASM cell proliferation are major contributors to the exaggerated airway narrowing that occurs during agonist stimulation. An emergent theme in this context is the role of inflammation-induced endoplasmic reticulum (ER) stress and altered mitochondrial function including an increase in the formation of reactive oxygen species (ROS). This may establish a vicious cycle as excess ROS generation leads to further ER stress. Yet, it is unclear whether inflammation-induced ROS is the major mechanism leading to ER stress or the consequence of ER stress. In various diseases, inflammation leads to an increase in mitochondrial fission (fragmentation), associated with reduced levels of mitochondrial fusion proteins, such as mitofusin 2 (Mfn2). Mitochondrial fragmentation may be a homeostatic response since it is generally coupled with mitochondrial biogenesis and mitochondrial volume density thereby reducing demand on individual mitochondrion. ER stress is triggered by the accumulation of unfolded proteins, which induces a homeostatic response to alter protein balance via effects on protein synthesis and degradation. In addition, the ER stress response promotes protein folding via increased expression of molecular chaperone proteins. Reduced Mfn2 and altered mitochondrial dynamics may not only be downstream to ER stress but also upstream such that a reduction in Mfn2 triggers further ER stress. In this review, we summarize the current understanding of the link between inflammation-induced ER stress and mitochondrial function and the role played in the pathophysiology of inflammatory airway diseases.
Collapse
Affiliation(s)
- Philippe Delmotte
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, MN, United States
| | - Gary C Sieck
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, MN, United States
| |
Collapse
|
87
|
Yap J, Chen X, Delmotte P, Sieck GC. TNFα selectively activates the IRE1α/XBP1 endoplasmic reticulum stress pathway in human airway smooth muscle cells. Am J Physiol Lung Cell Mol Physiol 2020; 318:L483-L493. [PMID: 31940218 DOI: 10.1152/ajplung.00212.2019] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Airway inflammation is a key aspect of diseases such as asthma. Proinflammatory cytokines such as TNFα mediate the inflammatory response. In various diseases, inflammation leads to endoplasmic reticulum (ER) stress, the accumulation of unfolded proteins, which triggers homeostatic responses to restore normal cellular function. We hypothesized that TNFα triggers ER stress through an increase in reactive oxygen species generation in human airway smooth muscle (hASM) with a downstream effect on mitofusin 2 (Mfn2). In hASM cells isolated from lung specimens incidental to patient surgery, dose- and time-dependent effects of TNFα exposure were assessed. Exposure of hASM to tunicamycin was used as a positive control. Tempol (500 μM) was used as superoxide scavenger. Activation of three ER stress pathways were evaluated by Western blotting: 1) autophosphorylation of inositol-requiring enzyme1 (IRE1α) leading to splicing of X-box binding protein 1 (XBP1); 2) autophosphorylation of protein kinase RNA-like endoplasmic reticulum kinase (PERK) leading to phosphorylation of eukaryotic initiation factor 2α; and 3) translocation and cleavage of activating transcription factor 6 (ATF6). We found that exposure of hASM cells to tunicamycin activated all three ER stress pathways. In contrast, TNFα selectively activated the IRE1α/XBP1 pathway in a dose- and time-dependent fashion. Our results indicate that TNFα does not activate the PERK and ATF6 pathways. Exposure of hASM cells to TNFα also decreased Mfn2 protein expression. Concurrent exposure to TNFα and tempol reversed the effect of TNFα on IRE1α phosphorylation and Mfn2 protein expression. Selective activation of the IRE1α/XBP1 pathway in hASM cells after exposure to TNFα may reflect a unique homeostatic role of this pathway in the inflammatory response of hASM cells.
Collapse
Affiliation(s)
- John Yap
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota
| | - Xujiao Chen
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota
| | - Philippe Delmotte
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota
| | - Gary C Sieck
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota
| |
Collapse
|
88
|
Calpain Activation by Ca2+ and Its Role in Phagocytosis. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1246:129-151. [DOI: 10.1007/978-3-030-40406-2_8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
|
89
|
|
90
|
Wang WA, Agellon LB, Michalak M. Organellar Calcium Handling in the Cellular Reticular Network. Cold Spring Harb Perspect Biol 2019; 11:cshperspect.a038265. [PMID: 31358518 DOI: 10.1101/cshperspect.a038265] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Ca2+ is an important intracellular messenger affecting diverse cellular processes. In eukaryotic cells, Ca2+ is handled by a myriad of Ca2+-binding proteins found in organelles that are organized into the cellular reticular network (CRN). The network is comprised of the endoplasmic reticulum, Golgi apparatus, lysosomes, membranous components of the endocytic and exocytic pathways, peroxisomes, and the nuclear envelope. Membrane contact sites between the different components of the CRN enable the rapid movement of Ca2+, and communication of Ca2+ status, within the network. Ca2+-handling proteins that reside in the CRN facilitate Ca2+ sensing, buffering, and cellular signaling to coordinate the many processes that operate within the cell.
Collapse
Affiliation(s)
- Wen-An Wang
- Department of Biochemistry, University of Alberta, Edmonton, Alberta T6G 2S7, Canada
| | - Luis B Agellon
- School of Human Nutrition, McGill University, Ste. Anne de Bellevue, Quebec H9X 3V9, Canada
| | - Marek Michalak
- Department of Biochemistry, University of Alberta, Edmonton, Alberta T6G 2S7, Canada
| |
Collapse
|
91
|
Modeling the role of endoplasmic reticulum-mitochondria microdomains in calcium dynamics. Sci Rep 2019; 9:17072. [PMID: 31745211 PMCID: PMC6864103 DOI: 10.1038/s41598-019-53440-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2019] [Accepted: 10/31/2019] [Indexed: 12/12/2022] Open
Abstract
Upon inositol trisphosphate (IP3) stimulation of non-excitable cells, including vascular endothelial cells, calcium (Ca2+) shuttling between the endoplasmic reticulum (ER) and mitochondria, facilitated by complexes called Mitochondria-Associated ER Membranes (MAMs), is known to play an important role in the occurrence of cytosolic Ca2+ concentration ([Ca2+]Cyt) oscillations. A mathematical compartmental closed-cell model of Ca2+ dynamics was developed that accounts for ER-mitochondria Ca2+ microdomains as the µd compartment (besides the cytosol, ER and mitochondria), Ca2+ influx to/efflux from each compartment and Ca2+ buffering. Varying the distribution of functional receptors in MAMs vs. the rest of ER/mitochondrial membranes, a parameter called the channel connectivity coefficient (to the µd), allowed for generation of [Ca2+]Cytoscillations driven by distinct mechanisms at various levels of IP3 stimulation. Oscillations could be initiated by the transient opening of IP3 receptors facing either the cytosol or the µd, and subsequent refilling of the respective compartment by Ca2+ efflux from the ER and/or the mitochondria. Only under conditions where the µd became the oscillation-driving compartment, silencing the Mitochondrial Ca2+ Uniporter led to oscillation inhibition. Thus, the model predicts that alternative mechanisms can yield [Ca2+]Cyt oscillations in non-excitable cells, and, under certain conditions, the ER-mitochondria µd can play a regulatory role.
Collapse
|
92
|
Filadi R, Pizzo P. ER-mitochondria tethering and Ca 2+ crosstalk: The IP 3R team takes the field. Cell Calcium 2019; 84:102101. [PMID: 31622942 DOI: 10.1016/j.ceca.2019.102101] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 10/06/2019] [Accepted: 10/07/2019] [Indexed: 12/21/2022]
Abstract
Inter-organelle communication represents a booming topic in cell biology research, with endoplasmic reticulum (ER)-mitochondria coupling playing the lion's share. In a recent work, Bartok and colleagues found that inositol trisphosphates receptors (IP3Rs), in addition to their well-known involvement in ER-mitochondria Ca2+ transfer, are endowed with structural properties at organelles' interface.
Collapse
Affiliation(s)
- Riccardo Filadi
- Department of Biomedical Sciences, University of Padua, Via U. Bassi 58/B, 35121, Padua, Italy; Neuroscience Institute - Italian National Research Council (CNR), Padua, 35121, Italy
| | - Paola Pizzo
- Department of Biomedical Sciences, University of Padua, Via U. Bassi 58/B, 35121, Padua, Italy; Neuroscience Institute - Italian National Research Council (CNR), Padua, 35121, Italy.
| |
Collapse
|
93
|
Wacquier B, Combettes L, Dupont G. Cytoplasmic and Mitochondrial Calcium Signaling: A Two-Way Relationship. Cold Spring Harb Perspect Biol 2019; 11:cshperspect.a035139. [PMID: 31110132 DOI: 10.1101/cshperspect.a035139] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Intracellular Ca2+ signals are well organized in all cell types, and trigger a variety of vital physiological processes. The temporal and spatial characteristics of cytosolic Ca2+ increases are mainly governed by the fluxes of this ion across the membrane of the endoplasmic/sarcoplasmic reticulum and the plasma membrane. However, various Ca2+ transporters also allow for Ca2+ exchanges between the cytoplasm and mitochondria. Increases in mitochondrial Ca2+ stimulate the production of ATP, which allows the cells to cope with the increased energy demand created by the stimulus. Less widely appreciated is the fact that Ca2+ handling by mitochondria also shapes cytosolic Ca2+ signals. Indeed, the frequency, amplitude, and duration of cytosolic Ca2+ increases can be altered by modifying the rates of Ca2+ transport into, or from, mitochondria. In this review, we focus on the interplay between mitochondria and Ca2+ signaling, highlighting not only the consequences of cytosolic Ca2+ changes on mitochondrial Ca2+, but also how cytosolic Ca2+ dynamics is controlled by modifications of the Ca2+-handling properties and the metabolism of mitochondria.
Collapse
Affiliation(s)
- Benjamin Wacquier
- Unit of Theoretical Chronobiology, Faculté des Sciences, Université Libre de Bruxelles (ULB) CP231, B1050 Brussels, Belgium
| | | | - Geneviève Dupont
- Unit of Theoretical Chronobiology, Faculté des Sciences, Université Libre de Bruxelles (ULB) CP231, B1050 Brussels, Belgium
| |
Collapse
|
94
|
Live cell imaging of signaling and metabolic activities. Pharmacol Ther 2019; 202:98-119. [DOI: 10.1016/j.pharmthera.2019.06.003] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Accepted: 05/31/2019] [Indexed: 12/15/2022]
|
95
|
Abstract
In heart failure, alterations of Na+ and Ca2+ handling, energetic deficit, and oxidative stress in cardiac myocytes are important pathophysiological hallmarks. Mitochondria are central to these processes because they are the main source for ATP, but also reactive oxygen species (ROS), and their function is critically controlled by Ca2+ During physiological variations of workload, mitochondrial Ca2+ uptake is required to match energy supply to demand but also to keep the antioxidative capacity in a reduced state to prevent excessive emission of ROS. Mitochondria take up Ca2+ via the mitochondrial Ca2+ uniporter, which exists in a multiprotein complex whose molecular components were identified only recently. In heart failure, deterioration of cytosolic Ca2+ and Na+ handling hampers mitochondrial Ca2+ uptake and the ensuing Krebs cycle-induced regeneration of the reduced forms of NADH (nicotinamide adenine dinucleotide) and NADPH (nicotinamide adenine dinucleotide phosphate), giving rise to energetic deficit and oxidative stress. ROS emission from mitochondria can trigger further ROS release from neighboring mitochondria termed ROS-induced ROS release, and cross talk between different ROS sources provides a spatially confined cellular network of redox signaling. Although low levels of ROS may serve physiological roles, higher levels interfere with excitation-contraction coupling, induce maladaptive cardiac remodeling through redox-sensitive kinases, and cell death through mitochondrial permeability transition. Targeting the dysregulated interplay between excitation-contraction coupling and mitochondrial energetics may ameliorate the progression of heart failure.
Collapse
Affiliation(s)
- Edoardo Bertero
- From the Comprehensive Heart Failure Center, University Clinic Würzburg, Germany
| | - Christoph Maack
- From the Comprehensive Heart Failure Center, University Clinic Würzburg, Germany.
| |
Collapse
|
96
|
splitGFP Technology Reveals Dose-Dependent ER-Mitochondria Interface Modulation by α-Synuclein A53T and A30P Mutants. Cells 2019; 8:cells8091072. [PMID: 31547305 PMCID: PMC6769576 DOI: 10.3390/cells8091072] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2019] [Revised: 09/09/2019] [Accepted: 09/11/2019] [Indexed: 12/26/2022] Open
Abstract
Familial Parkinson’s disease (PD) is associated with duplication or mutations of α-synuclein gene, whose product is a presynaptic cytosolic protein also found in mitochondria and in mitochondrial-associated ER membranes. We have originally shown the role of α-syn as a modulator of the ER-mitochondria interface and mitochondrial Ca2+ transients, suggesting that, at mild levels of expression, α-syn sustains cell metabolism. Here, we investigated the possibility that α-syn action on ER-mitochondria tethering could be compromised by the presence of PD-related mutations. The clarification of this aspect could contribute to elucidate key mechanisms underlying PD. The findings reported so far are not consistent, possibly because of the different methods used to evaluate ER-mitochondria connectivity. Here, the effects of the PD-related α-syn mutations A53T and A30P on ER-mitochondria relationship were investigated in respect to Ca2+ handling and mitochondrial function using a newly generated SPLICS sensor and aequorin-based Ca2+measurements. We provided evidence that A53T and A30P amino acid substitution does not affect the ability of α-syn to enhance ER/mitochondria tethering and mitochondrial Ca2+ transients, but that this action was lost as soon as a high amount of TAT-delivered A53T and A30P α-syn mutants caused the redistribution of α-syn from cytoplasm to foci. Our results suggest a loss of function mechanism and highlight a possible connection between α-syn and ER-mitochondria Ca2+ cross-talk impairment to the pathogenesis of PD.
Collapse
|
97
|
Luptak I, Morgan R, Baka T, Croteau D, Moverman D, Sarnak H, Kirber M, Bachschmid MM, Colucci WS, Pimentel DR. Genetically targeted fluorescent probes reveal dynamic calcium responses to adrenergic signaling in multiple cardiomyocyte compartments. Int J Biochem Cell Biol 2019; 114:105569. [PMID: 31299273 PMCID: PMC6832870 DOI: 10.1016/j.biocel.2019.105569] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2019] [Revised: 07/05/2019] [Accepted: 07/07/2019] [Indexed: 10/26/2022]
Abstract
Calcium (Ca2+), an important second messenger, regulates many cellular activities and varies spatiotemporally within the cell. Conventional methods to monitor Ca2+ changes, such as synthetic Ca2+ indicators, are not targetable, while genetically encoded Ca2+ indicators (GECI) can be precisely directed to cellular compartments. GECIs are chimeric proteins composed of calmodulin (or other proteins that change conformation on Ca2+ binding) coupled with two fluorescent proteins that come closer together after an increase in [Ca2+], and enhance Förster resonance energy transfer (FRET) that allows for ratiometric [Ca2+] assessment. Here, adult rat ventricular myocytes were transfected with specifically targeted calmodulin-based GECIs and Ca2+ responses to a physiological stimulus, norepinephrine (NE, 10 μM), were observed in a) sarcoplasmic reticulum (SR), b) mitochondria, c) the space between the mitochondria and SR, termed the Mitochondria Associated Membrane space (MAM) and d) cytosol for 10 min after stimulation. In SR and mitochondria, NE increased the [Ca2+] ratio by 17% and by 8%, respectively. In the MAM the [Ca2+] ratio decreased by 16%, while in cytosol [Ca2+] remained unchanged. In conclusion, adrenergic stimulation causes distinct responses in the cardiomyocyte SR, mitochondria and MAM. Additionally, our work provides a toolkit-update for targeted [Ca2+] measurements in multiple cellular compartments.
Collapse
Affiliation(s)
- Ivan Luptak
- Myocardial Biology Unit, Boston University School of Medicine, Boston, MA, United States
| | - Robert Morgan
- Myocardial Biology Unit, Boston University School of Medicine, Boston, MA, United States
| | - Tomas Baka
- Institute of Pathophysiology, Faculty of Medicine, Comenius University, Bratislava, Slovakia
| | - Dominique Croteau
- Myocardial Biology Unit, Boston University School of Medicine, Boston, MA, United States
| | - Daniel Moverman
- Myocardial Biology Unit, Boston University School of Medicine, Boston, MA, United States
| | - Hannah Sarnak
- Myocardial Biology Unit, Boston University School of Medicine, Boston, MA, United States
| | - Michael Kirber
- Cellular Imaging Core, Boston University School of Medicine, Boston, MA, United States
| | - Markus M Bachschmid
- Vascular Biology Unit, Boston University School of Medicine, Boston, MA, United States
| | - Wilson S Colucci
- Myocardial Biology Unit, Boston University School of Medicine, Boston, MA, United States
| | - David R Pimentel
- Myocardial Biology Unit, Boston University School of Medicine, Boston, MA, United States.
| |
Collapse
|
98
|
Abstract
The heart consumes large amounts of energy in the form of ATP that is continuously replenished by oxidative phosphorylation in mitochondria and, to a lesser extent, by glycolysis. To adapt the ATP supply efficiently to the constantly varying demand of cardiac myocytes, a complex network of enzymatic and signalling pathways controls the metabolic flux of substrates towards their oxidation in mitochondria. In patients with heart failure, derangements of substrate utilization and intermediate metabolism, an energetic deficit, and oxidative stress are thought to underlie contractile dysfunction and the progression of the disease. In this Review, we give an overview of the physiological processes of cardiac energy metabolism and their pathological alterations in heart failure and diabetes mellitus. Although the energetic deficit in failing hearts - discovered >2 decades ago - might account for contractile dysfunction during maximal exertion, we suggest that the alterations of intermediate substrate metabolism and oxidative stress rather than an ATP deficit per se account for maladaptive cardiac remodelling and dysfunction under resting conditions. Treatments targeting substrate utilization and/or oxidative stress in mitochondria are currently being tested in patients with heart failure and might be promising tools to improve cardiac function beyond that achieved with neuroendocrine inhibition.
Collapse
|
99
|
A mathematical model of calcium dynamics: Obesity and mitochondria-associated ER membranes. PLoS Comput Biol 2019; 15:e1006661. [PMID: 31437152 PMCID: PMC6726250 DOI: 10.1371/journal.pcbi.1006661] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Revised: 09/04/2019] [Accepted: 08/03/2019] [Indexed: 12/27/2022] Open
Abstract
Multiple cellular organelles tightly orchestrate intracellular calcium (Ca2+) dynamics to regulate cellular activities and maintain homeostasis. The interplay between the endoplasmic reticulum (ER), a major store of intracellular Ca2+, and mitochondria, an important source of adenosine triphosphate (ATP), has been the subject of much research, as their dysfunction has been linked with metabolic diseases. Interestingly, throughout the cell’s cytosolic domain, these two organelles share common microdomains called mitochondria-associated ER membranes (MAMs), where their membranes are in close apposition. The role of MAMs is critical for intracellular Ca2+ dynamics as they provide hubs for direct Ca2+ exchange between the organelles. A recent experimental study reported correlation between obesity and MAM formation in mouse liver cells, and obesity-related cellular changes that are closely associated with the regulation of Ca2+ dynamics. We constructed a mathematical model to study the effects of MAM Ca2+ dynamics on global Ca2+ activities. Through a series of model simulations, we investigated cellular mechanisms underlying the altered Ca2+ dynamics in the cells under obesity. We predict that, as the dosage of stimulus gradually increases, liver cells from obese mice will reach the state of saturated cytosolic Ca2+ concentration at a lower stimulus concentration, compared to cells from healthy mice. It is well known that intracellular Ca2+ oscillations carry encoded signals in their amplitude and frequency to regulate various cellular processes, and accumulating evidence supports the importance of the interplay between the ER and mitochondria in cellular Ca2+ homeostasis. Miscommunications between the organelles may be involved in the development of metabolic diseases. Based on a recent experimental study that spotlighted a correlation between obesity and physical interactions of the ER and mitochondria in mouse hepatic cells, we constructed a mathematical model as a tool to probe the effects of the cellular changes linked with obesity on global cellular Ca2+ dynamics. Our model successfully reproduced the experimental study that observed a positive correlation between an increase in ER-mitochondrial junctions and the magnitude of mitochondrial Ca2+ responses. We postulate that hepatic cells from lean animals exhibit Ca2+ oscillations that are more robust under higher concentrations of stimulus, compared to cells from obese animals.
Collapse
|
100
|
Costa R, Peruzzo R, Bachmann M, Montà GD, Vicario M, Santinon G, Mattarei A, Moro E, Quintana-Cabrera R, Scorrano L, Zeviani M, Vallese F, Zoratti M, Paradisi C, Argenton F, Brini M, Calì T, Dupont S, Szabò I, Leanza L. Impaired Mitochondrial ATP Production Downregulates Wnt Signaling via ER Stress Induction. Cell Rep 2019; 28:1949-1960.e6. [PMID: 31433973 DOI: 10.1016/j.celrep.2019.07.050] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Revised: 03/01/2019] [Accepted: 07/16/2019] [Indexed: 02/02/2023] Open
Abstract
Wnt signaling affects fundamental development pathways and, if aberrantly activated, promotes the development of cancers. Wnt signaling is modulated by different factors, but whether the mitochondrial energetic state affects Wnt signaling is unknown. Here, we show that sublethal concentrations of different compounds that decrease mitochondrial ATP production specifically downregulate Wnt/β-catenin signaling in vitro in colon cancer cells and in vivo in zebrafish reporter lines. Accordingly, fibroblasts from a GRACILE syndrome patient and a generated zebrafish model lead to reduced Wnt signaling. We identify a mitochondria-Wnt signaling axis whereby a decrease in mitochondrial ATP reduces calcium uptake into the endoplasmic reticulum (ER), leading to endoplasmic reticulum stress and to impaired Wnt signaling. In turn, the recovery of the ATP level or the inhibition of endoplasmic reticulum stress restores Wnt activity. These findings reveal a mechanism that links mitochondrial energetic metabolism to the control of the Wnt pathway that may be beneficial against several pathologies.
Collapse
Affiliation(s)
- Roberto Costa
- Department of Biology, University of Padova, Padova, Italy
| | | | | | | | - Mattia Vicario
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Giulia Santinon
- Department of Molecular Medicine, University of Padova, Padova, Italy
| | - Andrea Mattarei
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, Padova, Italy
| | - Enrico Moro
- Department of Molecular Medicine, University of Padova, Padova, Italy
| | - Rubén Quintana-Cabrera
- Department of Biology, University of Padova, Padova, Italy; Venetian Institute of Molecular Medicine, Padova, Padova, Italy
| | - Luca Scorrano
- Department of Biology, University of Padova, Padova, Italy; Venetian Institute of Molecular Medicine, Padova, Padova, Italy
| | - Massimo Zeviani
- MRC Mitochondrial Biology Unit, University of Cambridge, Cambridge, UK
| | - Francesca Vallese
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Mario Zoratti
- Department of Biomedical Sciences, University of Padova, Padova, Italy; CNR Institute of Neuroscience, Padova, Italy
| | - Cristina Paradisi
- Department of Chemical Sciences, University of Padova, Padova, Italy
| | | | - Marisa Brini
- Department of Biology, University of Padova, Padova, Italy
| | - Tito Calì
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Sirio Dupont
- Department of Molecular Medicine, University of Padova, Padova, Italy
| | - Ildikò Szabò
- Department of Biology, University of Padova, Padova, Italy; CNR Institute of Neuroscience, Padova, Italy.
| | - Luigi Leanza
- Department of Biology, University of Padova, Padova, Italy.
| |
Collapse
|