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Di Marco G, Gherardi G, De Mario A, Piazza I, Baraldo M, Mattarei A, Blaauw B, Rizzuto R, De Stefani D, Mammucari C. The mitochondrial ATP-dependent potassium channel (mitoK ATP) controls skeletal muscle structure and function. Cell Death Dis 2024; 15:58. [PMID: 38233399 PMCID: PMC10794173 DOI: 10.1038/s41419-024-06426-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Revised: 12/20/2023] [Accepted: 01/02/2024] [Indexed: 01/19/2024]
Abstract
MitoKATP is a channel of the inner mitochondrial membrane that controls mitochondrial K+ influx according to ATP availability. Recently, the genes encoding the pore-forming (MITOK) and the regulatory ATP-sensitive (MITOSUR) subunits of mitoKATP were identified, allowing the genetic manipulation of the channel. Here, we analyzed the role of mitoKATP in determining skeletal muscle structure and activity. Mitok-/- muscles were characterized by mitochondrial cristae remodeling and defective oxidative metabolism, with consequent impairment of exercise performance and altered response to damaging muscle contractions. On the other hand, constitutive mitochondrial K+ influx by MITOK overexpression in the skeletal muscle triggered overt mitochondrial dysfunction and energy default, increased protein polyubiquitination, aberrant autophagy flux, and induction of a stress response program. MITOK overexpressing muscles were therefore severely atrophic. Thus, the proper modulation of mitoKATP activity is required for the maintenance of skeletal muscle homeostasis and function.
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Affiliation(s)
- Giulia Di Marco
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Gaia Gherardi
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Agnese De Mario
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Ilaria Piazza
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | | | - Andrea Mattarei
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, Padova, Italy
| | - Bert Blaauw
- Department of Biomedical Sciences, University of Padova, Padova, Italy
- Venetian Institute of Molecular Medicine, Padova, Italy
- Myology Center (CIR-Myo), University of Padova, Padova, Italy
| | - Rosario Rizzuto
- Department of Biomedical Sciences, University of Padova, Padova, Italy
- Myology Center (CIR-Myo), University of Padova, Padova, Italy
| | - Diego De Stefani
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Cristina Mammucari
- Department of Biomedical Sciences, University of Padova, Padova, Italy.
- Myology Center (CIR-Myo), University of Padova, Padova, Italy.
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2
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Corrà S, Checchetto V, Brischigliaro M, Rampazzo C, Bottani E, Gagliani C, Cortese K, De Pittà C, Roverso M, De Stefani D, Bogialli S, Zeviani M, Viscomi C, Szabò I, Costa R. Drosophila Mpv17 forms an ion channel and regulates energy metabolism. iScience 2023; 26:107955. [PMID: 37810222 PMCID: PMC10558772 DOI: 10.1016/j.isci.2023.107955] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2022] [Revised: 07/15/2023] [Accepted: 09/14/2023] [Indexed: 10/10/2023] Open
Abstract
Mutations in MPV17 are a major contributor to mitochondrial DNA (mtDNA) depletion syndromes, a group of inherited genetic conditions due to mtDNA instability. To investigate the role of MPV17 in mtDNA maintenance, we generated and characterized a Drosophila melanogaster Mpv17 (dMpv17) KO model showing that the absence of dMpv17 caused profound mtDNA depletion in the fat body but not in other tissues, increased glycolytic flux and reduced lifespan in starvation. Accordingly, the expression of key genes of glycogenolysis and glycolysis was upregulated in dMpv17 KO flies. In addition, we demonstrated that dMpv17 formed a channel in planar lipid bilayers at physiological ionic conditions, and its electrophysiological hallmarks were affected by pathological mutations. Importantly, the reconstituted channel translocated uridine but not orotate across the membrane. Our results indicate that dMpv17 forms a channel involved in translocation of key metabolites and highlight the importance of dMpv17 in energy homeostasis and mitochondrial function.
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Affiliation(s)
- Samantha Corrà
- Veneto Institute of Molecular Medicine (VIMM), Padova, Italy
| | | | | | | | - Emanuela Bottani
- Department of Diagnostic and Public Health, University of Verona, Verona, Italy
| | - Cristina Gagliani
- Department of Experimental Medicine, University of Genova, Genova, Italy
| | - Katia Cortese
- Department of Experimental Medicine, University of Genova, Genova, Italy
| | | | - Marco Roverso
- Department of Chemical Sciences, University of Padova, Padova, Italy
| | - Diego De Stefani
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Sara Bogialli
- Department of Chemical Sciences, University of Padova, Padova, Italy
| | - Massimo Zeviani
- Department of Neurosciences, University of Padova, Padova, Italy
- IRCCS Materno Infantile Burlo Garofolo, Trieste, Italy
| | - Carlo Viscomi
- Veneto Institute of Molecular Medicine (VIMM), Padova, Italy
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Ildiko Szabò
- Department of Biology, University of Padova, Padova, Italy
| | - Rodolfo Costa
- Department of Biology, University of Padova, Padova, Italy
- Institute of Neuroscience, National Research Council of Italy (CNR), Padova, Italy
- Chronobiology Section, Faculty of Health and Medical Sciences, University of Surrey, Guildford, UK
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3
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Moro N, Antonucci S, Hammer K, Campo A, Borile G, Carullo P, Pesce P, Bariani R, Bauce B, Rizzuto R, De Stefani D, Mammucari C, Catalucci D, Maier L, Di Lisa F, Zaglia T, Mongillo M. Increasing mitochondrial Ca2+ uptake capacity enhances heart adaptation to pressure overload. J Mol Cell Cardiol 2022. [DOI: 10.1016/j.yjmcc.2022.08.075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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4
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Serrat R, Covelo A, Kouskoff V, Delcasso S, Ruiz-Calvo A, Chenouard N, Stella C, Blancard C, Salin B, Julio-Kalajzić F, Cannich A, Massa F, Varilh M, Deforges S, Robin LM, De Stefani D, Busquets-Garcia A, Gambino F, Beyeler A, Pouvreau S, Marsicano G. Astroglial ER-mitochondria calcium transfer mediates endocannabinoid-dependent synaptic integration. Cell Rep 2022; 41:111499. [DOI: 10.1016/j.celrep.2022.111499] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
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5
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Zampese E, Wokosin DL, Gonzalez-Rodriguez P, Guzman JN, Tkatch T, Kondapalli J, Surmeier WC, D’Alessandro KB, De Stefani D, Rizzuto R, Iino M, Molkentin JD, Chandel NS, Schumacker PT, Surmeier DJ. Ca 2+ channels couple spiking to mitochondrial metabolism in substantia nigra dopaminergic neurons. Sci Adv 2022; 8:eabp8701. [PMID: 36179023 PMCID: PMC9524841 DOI: 10.1126/sciadv.abp8701] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Accepted: 08/12/2022] [Indexed: 05/08/2023]
Abstract
How do neurons match generation of adenosine triphosphate by mitochondria to the bioenergetic demands of regenerative activity? Although the subject of speculation, this coupling is still poorly understood, particularly in neurons that are tonically active. To help fill this gap, pacemaking substantia nigra dopaminergic neurons were studied using a combination of optical, electrophysiological, and molecular approaches. In these neurons, spike-activated calcium (Ca2+) entry through Cav1 channels triggered Ca2+ release from the endoplasmic reticulum, which stimulated mitochondrial oxidative phosphorylation through two complementary Ca2+-dependent mechanisms: one mediated by the mitochondrial uniporter and another by the malate-aspartate shuttle. Disrupting either mechanism impaired the ability of dopaminergic neurons to sustain spike activity. While this feedforward control helps dopaminergic neurons meet the bioenergetic demands associated with sustained spiking, it is also responsible for their elevated oxidant stress and possibly to their decline with aging and disease.
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Affiliation(s)
- Enrico Zampese
- Department of Neuroscience, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
- Aligning Science Across Parkinson’s (ASAP) Collaborative Research Network, Chevy Chase, MD 20815, USA
| | - David L. Wokosin
- Department of Neuroscience, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
- Aligning Science Across Parkinson’s (ASAP) Collaborative Research Network, Chevy Chase, MD 20815, USA
| | - Patricia Gonzalez-Rodriguez
- Department of Neuroscience, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
- Aligning Science Across Parkinson’s (ASAP) Collaborative Research Network, Chevy Chase, MD 20815, USA
| | - Jaime N. Guzman
- Department of Neuroscience, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
- Aligning Science Across Parkinson’s (ASAP) Collaborative Research Network, Chevy Chase, MD 20815, USA
| | - Tatiana Tkatch
- Department of Neuroscience, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
- Aligning Science Across Parkinson’s (ASAP) Collaborative Research Network, Chevy Chase, MD 20815, USA
| | - Jyothisri Kondapalli
- Department of Neuroscience, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
- Aligning Science Across Parkinson’s (ASAP) Collaborative Research Network, Chevy Chase, MD 20815, USA
| | - William C. Surmeier
- Department of Neuroscience, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
- Aligning Science Across Parkinson’s (ASAP) Collaborative Research Network, Chevy Chase, MD 20815, USA
| | - Karis B. D’Alessandro
- Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Diego De Stefani
- Department of Biomedical Sciences, University of Padova, Padova 35131, Italy
| | - Rosario Rizzuto
- Department of Biomedical Sciences, University of Padova, Padova 35131, Italy
| | - Masamitsu Iino
- Department of Physiology, Nihon University School of Medicine, 30-1, Oyaguchi Kami-cho, Itabashi-ku, Tokyo 173-8610, Japan
| | - Jeffery D. Molkentin
- Department of Pediatrics, Cincinnati Children’s Hospital Medical Center, University of Cincinnati, Cincinnati, OH 45229, USA
| | - Navdeep S. Chandel
- Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Paul T. Schumacker
- Department of Pediatrics, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - D. James Surmeier
- Department of Neuroscience, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
- Aligning Science Across Parkinson’s (ASAP) Collaborative Research Network, Chevy Chase, MD 20815, USA
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6
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Cortese E, Moscatiello R, Pettiti F, Carraretto L, Baldan B, Frigerio L, Vothknecht UC, Szabo I, De Stefani D, Brini M, Navazio L. Monitoring calcium handling by the plant endoplasmic reticulum with a low-Ca 2+ -affinity targeted aequorin reporter. Plant J 2022; 109:1014-1027. [PMID: 34837294 PMCID: PMC9299891 DOI: 10.1111/tpj.15610] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 10/05/2021] [Accepted: 11/22/2021] [Indexed: 05/15/2023]
Abstract
Precise measurements of dynamic changes in free Ca2+ concentration in the lumen of the plant endoplasmic reticulum (ER) have been lacking so far, despite increasing evidence for the contribution of this intracellular compartment to Ca2+ homeostasis and signalling in the plant cell. In the present study, we targeted an aequorin chimera with reduced Ca2+ affinity to the ER membrane and facing the ER lumen. To this aim, the cDNA for a low-Ca2+ -affinity aequorin variant (AEQmut) was fused to the nucleotide sequence encoding a non-cleavable N-terminal ER signal peptide (fl2). The correct targeting of fl2-AEQmut was confirmed by immunocytochemical analyses in transgenic Arabidopsis thaliana (Arabidopsis) seedlings. An experimental protocol well-established in animal cells - consisting of ER Ca2+ depletion during photoprotein reconstitution followed by ER Ca2+ refilling - was applied to carry out ER Ca2+ measurements in planta. Rapid and transient increases of the ER luminal Ca2+ concentration ([Ca2+ ]ER ) were recorded in response to different environmental stresses, displaying stimulus-specific Ca2+ signatures. The comparative analysis of ER and chloroplast Ca2+ dynamics indicates a complex interplay of these organelles in shaping cytosolic Ca2+ signals during signal transduction events. Our data highlight significant differences in basal [Ca2+ ]ER and Ca2+ handling by plant ER compared to the animal counterpart. The set-up of an ER-targeted aequorin chimera extends and complements the currently available toolkit of organelle-targeted Ca2+ indicators by adding a reporter that improves our quantitative understanding of Ca2+ homeostasis in the plant endomembrane system.
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Affiliation(s)
- Enrico Cortese
- Department of BiologyUniversity of PadovaPadova35131Italy
| | | | | | | | - Barbara Baldan
- Department of BiologyUniversity of PadovaPadova35131Italy
- Botanical GardenUniversity of PadovaPadova35123Italy
| | | | - Ute C. Vothknecht
- Plant Cell BiologyInstitute of Cellular and Molecular BotanyUniversity of BonnBonnD‐53115Germany
| | - Ildiko Szabo
- Department of BiologyUniversity of PadovaPadova35131Italy
- Botanical GardenUniversity of PadovaPadova35123Italy
| | - Diego De Stefani
- Department of Biomedical SciencesUniversity of PadovaPadova35131Italy
| | - Marisa Brini
- Department of BiologyUniversity of PadovaPadova35131Italy
| | - Lorella Navazio
- Department of BiologyUniversity of PadovaPadova35131Italy
- Botanical GardenUniversity of PadovaPadova35123Italy
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7
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Serrat R, Covelo A, Kouskoff V, Delcasso S, Ruiz-Calvo A, Chenouard N, Stella C, Blancard C, Salin B, Julio-Kalajzić F, Cannich A, Massa F, Varilh M, Deforges S, Robin LM, De Stefani D, Busquets-Garcia A, Gambino F, Beyeler A, Pouvreau S, Marsicano G. Astroglial ER-mitochondria calcium transfer mediates endocannabinoid-dependent synaptic integration. Cell Rep 2021; 37:110133. [PMID: 34936875 DOI: 10.1016/j.celrep.2021.110133] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 10/08/2021] [Accepted: 11/23/2021] [Indexed: 10/19/2022] Open
Abstract
Intracellular calcium signaling underlies the astroglial control of synaptic transmission and plasticity. Mitochondria-endoplasmic reticulum contacts (MERCs) are key determinants of calcium dynamics, but their functional impact on astroglial regulation of brain information processing is unexplored. We found that the activation of astrocyte mitochondrial-associated type-1 cannabinoid (mtCB1) receptors determines MERC-dependent intracellular calcium signaling and synaptic integration. The stimulation of mtCB1 receptors promotes calcium transfer from the endoplasmic reticulum to mitochondria through a specific molecular cascade, involving the mitochondrial calcium uniporter (MCU). Physiologically, mtCB1-dependent mitochondrial calcium uptake determines the dynamics of cytosolic calcium events in astrocytes upon endocannabinoid mobilization. Accordingly, electrophysiological recordings in hippocampal slices showed that conditional genetic exclusion of mtCB1 receptors or dominant-negative MCU expression in astrocytes blocks lateral synaptic potentiation, through which astrocytes integrate the activity of distant synapses. Altogether, these data reveal an endocannabinoid link between astroglial MERCs and the regulation of brain network functions.
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Affiliation(s)
- Roman Serrat
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1215 NeuroCentre Magendie, 33077 Bordeaux, France; University of Bordeaux, 33077 Bordeaux, France; INRAE, Nutrition and Integrative Neurobiology, UMR 1286, Bordeaux, France
| | - Ana Covelo
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1215 NeuroCentre Magendie, 33077 Bordeaux, France; University of Bordeaux, 33077 Bordeaux, France
| | - Vladimir Kouskoff
- University of Bordeaux, 33077 Bordeaux, France; Interdisciplinary Institute for Neuroscience, CNRS UMR 5297, 33000 Bordeaux, France
| | - Sebastien Delcasso
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1215 NeuroCentre Magendie, 33077 Bordeaux, France; University of Bordeaux, 33077 Bordeaux, France; Institut de Biochimie et Genetique Cellulaires, CNRS UMR 5095, Bordeaux, France
| | - Andrea Ruiz-Calvo
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1215 NeuroCentre Magendie, 33077 Bordeaux, France; University of Bordeaux, 33077 Bordeaux, France
| | - Nicolas Chenouard
- University of Bordeaux, 33077 Bordeaux, France; Interdisciplinary Institute for Neuroscience, CNRS UMR 5297, 33000 Bordeaux, France
| | - Carol Stella
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1215 NeuroCentre Magendie, 33077 Bordeaux, France; University of Bordeaux, 33077 Bordeaux, France
| | - Corinne Blancard
- University of Bordeaux, 33077 Bordeaux, France; Institut de Biochimie et Genetique Cellulaires, CNRS UMR 5095, Bordeaux, France
| | - Benedicte Salin
- University of Bordeaux, 33077 Bordeaux, France; Institut de Biochimie et Genetique Cellulaires, CNRS UMR 5095, Bordeaux, France
| | - Francisca Julio-Kalajzić
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1215 NeuroCentre Magendie, 33077 Bordeaux, France; University of Bordeaux, 33077 Bordeaux, France
| | - Astrid Cannich
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1215 NeuroCentre Magendie, 33077 Bordeaux, France; University of Bordeaux, 33077 Bordeaux, France
| | - Federico Massa
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1215 NeuroCentre Magendie, 33077 Bordeaux, France; University of Bordeaux, 33077 Bordeaux, France
| | - Marjorie Varilh
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1215 NeuroCentre Magendie, 33077 Bordeaux, France; University of Bordeaux, 33077 Bordeaux, France
| | - Severine Deforges
- University of Bordeaux, 33077 Bordeaux, France; Interdisciplinary Institute for Neuroscience, CNRS UMR 5297, 33000 Bordeaux, France
| | - Laurie M Robin
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1215 NeuroCentre Magendie, 33077 Bordeaux, France; University of Bordeaux, 33077 Bordeaux, France
| | - Diego De Stefani
- Department of Biomedical Sciences, University of Padua, 35131 Padua, Italy
| | - Arnau Busquets-Garcia
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1215 NeuroCentre Magendie, 33077 Bordeaux, France; University of Bordeaux, 33077 Bordeaux, France
| | - Frederic Gambino
- University of Bordeaux, 33077 Bordeaux, France; Interdisciplinary Institute for Neuroscience, CNRS UMR 5297, 33000 Bordeaux, France
| | - Anna Beyeler
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1215 NeuroCentre Magendie, 33077 Bordeaux, France; University of Bordeaux, 33077 Bordeaux, France
| | - Sandrine Pouvreau
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1215 NeuroCentre Magendie, 33077 Bordeaux, France; University of Bordeaux, 33077 Bordeaux, France; Interdisciplinary Institute for Neuroscience, CNRS UMR 5297, 33000 Bordeaux, France.
| | - Giovanni Marsicano
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1215 NeuroCentre Magendie, 33077 Bordeaux, France; University of Bordeaux, 33077 Bordeaux, France.
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8
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Checchetto V, Leanza L, De Stefani D, Rizzuto R, Gulbins E, Szabo I. Mitochondrial K + channels and their implications for disease mechanisms. Pharmacol Ther 2021; 227:107874. [PMID: 33930454 DOI: 10.1016/j.pharmthera.2021.107874] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Accepted: 04/12/2021] [Indexed: 02/06/2023]
Abstract
The field of mitochondrial ion channels underwent a rapid development during the last decade, thanks to the molecular identification of some of the nuclear-encoded organelle channels and to advances in strategies allowing specific pharmacological targeting of these proteins. Thereby, genetic tools and specific drugs aided definition of the relevance of several mitochondrial channels both in physiological as well as pathological conditions. Unfortunately, in the case of mitochondrial K+ channels, efforts of genetic manipulation provided only limited results, due to their dual localization to mitochondria and to plasma membrane in most cases. Although the impact of mitochondrial K+ channels on human diseases is still far from being genuinely understood, pre-clinical data strongly argue for their substantial role in the context of several pathologies, including cardiovascular and neurodegenerative diseases as well as cancer. Importantly, these channels are druggable targets, and their in-depth investigation could thus pave the way to the development of innovative small molecules with huge therapeutic potential. In the present review we summarize the available experimental evidence that mechanistically link mitochondrial potassium channels to the above pathologies and underline the possibility of exploiting them for therapy.
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Affiliation(s)
| | - Luigi Leanza
- Department of Biology, University of Padova, Italy
| | | | - Rosario Rizzuto
- Department of Biomedical Sciences, University of Padova, Italy
| | - Erich Gulbins
- Department of Molecular Biology, University of Duisburg-Essen, Germany
| | - Ildiko Szabo
- Department of Biology, University of Padova, Italy; CNR Institute of Neurosciences, Italy.
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9
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Di Marco G, Vallese F, Jourde B, Bergsdorf C, Sturlese M, De Mario A, Techer-Etienne V, Haasen D, Oberhauser B, Schleeger S, Minetti G, Moro S, Rizzuto R, De Stefani D, Fornaro M, Mammucari C. A High-Throughput Screening Identifies MICU1 Targeting Compounds. Cell Rep 2021; 30:2321-2331.e6. [PMID: 32075766 PMCID: PMC7034061 DOI: 10.1016/j.celrep.2020.01.081] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Revised: 01/08/2020] [Accepted: 01/22/2020] [Indexed: 01/01/2023] Open
Abstract
Mitochondrial Ca2+ uptake depends on the mitochondrial calcium uniporter (MCU) complex, a highly selective channel of the inner mitochondrial membrane (IMM). Here, we screen a library of 44,000 non-proprietary compounds for their ability to modulate mitochondrial Ca2+ uptake. Two of them, named MCU-i4 and MCU-i11, are confirmed to reliably decrease mitochondrial Ca2+ influx. Docking simulations reveal that these molecules directly bind a specific cleft in MICU1, a key element of the MCU complex that controls channel gating. Accordingly, in MICU1-silenced or deleted cells, the inhibitory effect of the two compounds is lost. Moreover, MCU-i4 and MCU-i11 fail to inhibit mitochondrial Ca2+ uptake in cells expressing a MICU1 mutated in the critical amino acids that forge the predicted binding cleft. Finally, these compounds are tested ex vivo, revealing a primary role for mitochondrial Ca2+ uptake in muscle growth. Overall, MCU-i4 and MCU-i11 represent leading molecules for the development of MICU1-targeting drugs. An HTS identifies MCU-i4 and MCU-i11 as negative modulators of the MCU MCU-i4 and MCU-i11 bind MICU1 MICU1 is required for the activity of MCU-i4 and MCU-i11 MCU-i4 and MCU-i11 impair muscle cell growth
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Affiliation(s)
- Giulia Di Marco
- Department of Biomedical Sciences, University of Padua, 35131 Padua, Italy
| | - Francesca Vallese
- Department of Biomedical Sciences, University of Padua, 35131 Padua, Italy
| | - Benjamin Jourde
- Novartis Institutes for Biomedical Research, Novartis Campus, 4056 Basel, Switzerland
| | - Christian Bergsdorf
- Novartis Institutes for Biomedical Research, Novartis Campus, 4056 Basel, Switzerland
| | - Mattia Sturlese
- Molecular Modeling Section, Department of Pharmaceutical and Pharmacological Sciences, University of Padua, 35131 Padua, Italy
| | - Agnese De Mario
- Department of Biomedical Sciences, University of Padua, 35131 Padua, Italy
| | | | - Dorothea Haasen
- Novartis Institutes for Biomedical Research, Novartis Campus, 4056 Basel, Switzerland
| | - Berndt Oberhauser
- Novartis Institutes for Biomedical Research, Novartis Campus, 4056 Basel, Switzerland
| | - Simone Schleeger
- Novartis Institutes for Biomedical Research, Novartis Campus, 4056 Basel, Switzerland
| | - Giulia Minetti
- Novartis Institutes for Biomedical Research, Novartis Campus, 4056 Basel, Switzerland
| | - Stefano Moro
- Molecular Modeling Section, Department of Pharmaceutical and Pharmacological Sciences, University of Padua, 35131 Padua, Italy
| | - Rosario Rizzuto
- Department of Biomedical Sciences, University of Padua, 35131 Padua, Italy
| | - Diego De Stefani
- Department of Biomedical Sciences, University of Padua, 35131 Padua, Italy
| | - Mara Fornaro
- Novartis Institutes for Biomedical Research, Novartis Campus, 4056 Basel, Switzerland.
| | - Cristina Mammucari
- Department of Biomedical Sciences, University of Padua, 35131 Padua, Italy.
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10
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Trevellin E, Granzotto M, Host C, Grisan F, De Stefani D, Grinzato A, Lefkimmiatis K, Pagano C, Rizzuto R, Vettor R. A Novel Loss of Function Melanocortin-4-Receptor Mutation (MC4R-F313Sfs*29) in Morbid Obesity. J Clin Endocrinol Metab 2021; 106:736-749. [PMID: 33247923 DOI: 10.1210/clinem/dgaa885] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Indexed: 11/19/2022]
Abstract
CONTEXT Melanocortin receptor-4 (MC4R) gene mutations are associated with early-onset severe obesity, and the identification of potential pathological variants is crucial for the clinical management of patients with obesity. OBJECTIVE To explore whether and how a novel heterozygous MC4R variant (MC4R-F313Sfs*29), identified in a young boy (body mass index [BMI] 38.8 kg/m2) during a mutation analysis conducted in a cohort of patients with obesity, plays a determinant pathophysiological role in the obesity development. DESIGN SETTING AND PATIENTS The genetic screening was carried out in a total of 209 unrelated patients with obesity (BMI ≥ 35 kg/m2). Structural and functional characterization of the F313Sfs*29-mutated MC4R was performed using computational approaches and in vitro, using HEK293 cells transfected with genetically encoded biosensors for cAMP and Ca2+. RESULTS The F313Sfs*29 was the only variant identified. In vitro experiments showed that HEK293 cells transfected with the mutated form of MC4R did not increase intracellular cAMP or Ca2+ levels after stimulation with a specific agonist in comparison with HEK293 cells transfected with the wild type form of MC4R (∆R/R0 = -90% ± 8%; P < 0.001). In silico modeling showed that the F313Sfs*29 mutation causes a major reorganization in the cytosolic domain of MC4R, thus reducing the affinity of the putative GalphaS binding site. CONCLUSIONS The newly discovered F313Sfs*29 variant of MC4R may be involved in the impairment of α-MSH-induced cAMP and Ca2+ signaling, blunting intracellular G protein-mediated signal transduction. This alteration might have led to the dysregulation of satiety signaling, resulting in hyperphagia and early onset of obesity.
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Affiliation(s)
| | - Marnie Granzotto
- Department of Medicine - DIMED, University of Padua, Padua, Italy
| | - Cristina Host
- Department of Reproduction and Growth, University Hospital of Ferrara, Ferrara, Italy
| | - Francesca Grisan
- Foundation for Advanced Biomedical Research, Venetian Institute of Molecular Medicine, Padua, Italy
- Department of Biology, University of Padua, Padua, Italy
| | - Diego De Stefani
- Department of Biomedical Sciences, University of Padua, Padua, Italy
| | | | - Konstantinos Lefkimmiatis
- Foundation for Advanced Biomedical Research, Venetian Institute of Molecular Medicine, Padua, Italy
- Department of Molecular Medicine, University of Pavia, Pavia, Italy
| | - Claudio Pagano
- Department of Medicine - DIMED, University of Padua, Padua, Italy
| | - Rosario Rizzuto
- Department of Biomedical Sciences, University of Padua, Padua, Italy
| | - Roberto Vettor
- Department of Medicine - DIMED, University of Padua, Padua, Italy
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11
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Liviero F, Scarpa MC, De Stefani D, Folino F, Campisi M, Mason P, Iliceto S, Pavanello S, Maestrelli P. Modulation of TRPV-1 by prostaglandin-E 2 and bradykinin changes cough sensitivity and autonomic regulation of cardiac rhythm in healthy subjects. Sci Rep 2020; 10:15163. [PMID: 32938990 PMCID: PMC7494872 DOI: 10.1038/s41598-020-72062-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Accepted: 08/25/2020] [Indexed: 11/17/2022] Open
Abstract
A neurogenic pathway, involving airway TRPV-1, has been implicated in acute cardiovascular events occurring after peaks of air pollution. We tested whether inhaled prostaglandin-E2 (PGE2) and bradykinin (BK) regulate TRPV-1 activity in vivo by changing cough response to capsaicin (CPS) and affecting heart rate variability (HRV), while also taking into account the influence of TRPV-1 polymorphisms (SNPs). Moreover, we assessed the molecular mechanism of TRPV-1 modulation in vitro. Seventeen healthy volunteers inhaled 100 μg PGE2, 200 μg BK or diluent in a randomized double-blind fashion. Subsequently, the response to CPS was assessed by cough challenge and the sympathetic activity by HRV, expressed by low (nLF) and high (nHF) normalized frequency components, as well as nLF/nHF ratio. Intracellular [Ca2+] was measured in HeLa cells, transfected with wild-type TRPV-1, pre-treated with increasing doses of PGE2, BK or diesel exhaust particulate (DEP), after CPS stimulation. Six functional TRPV-1 SNPs were characterized in DNA from each subject. Inhalation of PGE2 and BK was associated with significant increases in cough response induced by 30 μM of CPS (cough number after PGE2 = 4.20 ± 0.42; p < 0.001, and after BK = 3.64 ± 0.37; p < 0.01), compared to diluent (2.77 ± 0.29) and in sympathetic activity (nLF/nHF ratio after PGE2 = 6.1; p < 0.01, and after BK = 4.2; p < 0.05), compared to diluent (2.5–3.3). No influence of SNPs was observed on autonomic regulation and cough sensitivity. Unlike PGE2 and BK, DEP directly activated TRPV-1. Inhalation of PGE2 and BK sensitizes TRPV-1 and is associated with autonomic dysregulation of cardiac rhythm in healthy subjects.
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Affiliation(s)
- Filippo Liviero
- Department of Cardiac, Thoracic, Vascular Sciences and Public Health, University of Padova, Via Giustiniani 2, 35128, Padua, Italy
| | - Maria Cristina Scarpa
- Department of Cardiac, Thoracic, Vascular Sciences and Public Health, University of Padova, Via Giustiniani 2, 35128, Padua, Italy
| | - Diego De Stefani
- Department of Biomedical Sciences, University of Padova, Padua, Italy
| | - Franco Folino
- Department of Cardiac, Thoracic, Vascular Sciences and Public Health, University of Padova, Via Giustiniani 2, 35128, Padua, Italy
| | - Manuela Campisi
- Department of Cardiac, Thoracic, Vascular Sciences and Public Health, University of Padova, Via Giustiniani 2, 35128, Padua, Italy
| | - Paola Mason
- Department of Cardiac, Thoracic, Vascular Sciences and Public Health, University of Padova, Via Giustiniani 2, 35128, Padua, Italy
| | - Sabino Iliceto
- Department of Cardiac, Thoracic, Vascular Sciences and Public Health, University of Padova, Via Giustiniani 2, 35128, Padua, Italy
| | - Sofia Pavanello
- Department of Cardiac, Thoracic, Vascular Sciences and Public Health, University of Padova, Via Giustiniani 2, 35128, Padua, Italy.
| | - Piero Maestrelli
- Department of Cardiac, Thoracic, Vascular Sciences and Public Health, University of Padova, Via Giustiniani 2, 35128, Padua, Italy
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12
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Cerqueira FM, von Stockum S, Giacomello M, Goliand I, Kakimoto P, Marchesan E, De Stefani D, Kowaltowski AJ, Ziviani E, Shirihai OS. A new target for an old DUB: UCH-L1 regulates mitofusin-2 levels, altering mitochondrial morphology, function and calcium uptake. Redox Biol 2020; 37:101676. [PMID: 32956978 PMCID: PMC7509235 DOI: 10.1016/j.redox.2020.101676] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 07/13/2020] [Accepted: 08/03/2020] [Indexed: 12/25/2022] Open
Abstract
UCH-L1 is a deubiquitinating enzyme (DUB), highly abundant in neurons, with a sub-cellular localization dependent on its farnesylation state. Despite UCH-L1′s association with familial Parkinson's Disease (PD), the effects on mitochondrial bioenergetics and quality control remain unexplored. Here we investigated the role of UCHL-1 in mitochondrial dynamics and bioenergetics. We demonstrate that knock-down (KD) of UCH-L1 in different cell lines reduces the levels of the mitochondrial fusion protein Mitofusin-2, but not Mitofusin-1, resulting in mitochondrial enlargement and disruption of the tubular network. This was associated with lower tethering between mitochondria and the endoplasmic reticulum, consequently altering mitochondrial calcium uptake. Respiratory function was also altered, as UCH-L1 KD cells displayed higher proton leak and maximum respiratory capacity. Conversely, overexpression of UCH-L1 increased Mfn2 levels, an effect dramatically enhanced by the mutation of the farnesylation site (C220S), which drives UCH-L1 binding to membranes. These data indicate that the soluble cytosolic form of UCH-L1 regulates Mitofusin-2 levels and mitochondrial function. These effects are biologically conserved, since knock-down of the corresponding UCH-L1 ortholog in D. melanogaster reduces levels of the mitofusin ortholog Marf and also increases mitochondrial respiratory capacity. We thus show that Mfn-2 levels are directly affected by UCH-L1, demonstrating that the mitochondrial roles of DUBs go beyond controlling mitophagy rates.
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Affiliation(s)
- Fernanda M Cerqueira
- Obesity Research Center, Molecular Medicine, Boston University School of Medicine, Boston, MA, 02111, USA; National Institute for Biotechnology in the Negev, Ben Gurion University, Beer-Sheva, 8410501, Israel; Department of Biology, University of Padua, Padua, 35121, Italy
| | | | - Marta Giacomello
- Department of Biology, University of Padua, Padua, 35121, Italy; Department of Biomedical Sciences, University of Padua, 35121, Italy
| | - Inna Goliand
- National Institute for Biotechnology in the Negev, Ben Gurion University, Beer-Sheva, 8410501, Israel
| | - Pamela Kakimoto
- Departmento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, 05508-900, Brazil
| | - Elena Marchesan
- Department of Biology, University of Padua, Padua, 35121, Italy
| | - Diego De Stefani
- Department of Biomedical Sciences, University of Padua, 35121, Italy
| | - Alicia J Kowaltowski
- Departmento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, 05508-900, Brazil
| | - Elena Ziviani
- Department of Biology, University of Padua, Padua, 35121, Italy
| | - Orian S Shirihai
- Obesity Research Center, Molecular Medicine, Boston University School of Medicine, Boston, MA, 02111, USA; UCLA Section of Endocrinology, Department of Medicine, David Geffen School of Medicine, UCLA, CA, 9095-7073, USA.
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13
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Li S, Wu Z, Li Y, Tantray I, De Stefani D, Mattarei A, Krishnan G, Gao FB, Vogel H, Lu B. Altered MICOS Morphology and Mitochondrial Ion Homeostasis Contribute to Poly(GR) Toxicity Associated with C9-ALS/FTD. Cell Rep 2020; 32:107989. [PMID: 32755582 PMCID: PMC7433775 DOI: 10.1016/j.celrep.2020.107989] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Revised: 05/20/2020] [Accepted: 07/14/2020] [Indexed: 12/31/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) manifests pathological changes in motor neurons and various other cell types. Compared to motor neurons, the contribution of the other cell types to the ALS phenotypes is understudied. G4C2 repeat expansion in C9ORF72 is the most common genetic cause of ALS along with frontotemporal dementia (C9-ALS/FTD), with increasing evidence supporting repeat-encoded poly(GR) in disease pathogenesis. Here, we show in Drosophila muscle that poly(GR) enters mitochondria and interacts with components of the Mitochondrial Contact Site and Cristae Organizing System (MICOS), altering MICOS dynamics and intra-subunit interactions. This impairs mitochondrial inner membrane structure, ion homeostasis, mitochondrial metabolism, and muscle integrity. Similar mitochondrial defects are observed in patient fibroblasts. Genetic manipulation of MICOS components or pharmacological restoration of ion homeostasis with nigericin effectively rescue the mitochondrial pathology and disease phenotypes in both systems. These results implicate MICOS-regulated ion homeostasis in C9-ALS pathogenesis and suggest potential new therapeutic strategies.
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Affiliation(s)
- Shuangxi Li
- Department of Pathology, Stanford University School of Medicine, Stanford, CA, USA,These authors contributed equally
| | - Zhihao Wu
- Department of Pathology, Stanford University School of Medicine, Stanford, CA, USA,These authors contributed equally,Present address: Department of Biological Sciences, Dedman College of Humanities and Sciences, Southern Methodist University, Dallas TX 75275, USA
| | - Yu Li
- Department of Pathology, Stanford University School of Medicine, Stanford, CA, USA
| | - Ishaq Tantray
- Department of Pathology, Stanford University School of Medicine, Stanford, CA, USA
| | - Diego De Stefani
- Department of Biomedical Sciences, University of Padova, Via Ugo Bassi 58/B, 35131 Padova, Italy
| | - Andrea Mattarei
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, Via F. Marzolo 5, 35131 Padova, Italy
| | - Gopinath Krishnan
- Department of Neurology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Fen-Biao Gao
- Department of Neurology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Hannes Vogel
- Department of Pathology, Stanford University School of Medicine, Stanford, CA, USA
| | - Bingwei Lu
- Department of Pathology, Stanford University School of Medicine, Stanford, CA, USA,Lead Contact,Correspondence:
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14
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Davinelli S, De Stefani D, De Vivo I, Scapagnini G. Polyphenols as Caloric Restriction Mimetics Regulating Mitochondrial Biogenesis and Mitophagy. Trends Endocrinol Metab 2020; 31:536-550. [PMID: 32521237 DOI: 10.1016/j.tem.2020.02.011] [Citation(s) in RCA: 56] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2019] [Revised: 02/19/2020] [Accepted: 02/24/2020] [Indexed: 02/08/2023]
Abstract
The tight coordination between mitochondrial biogenesis and mitophagy can be dysregulated during aging, critically influencing whole-body metabolism, health, and lifespan. To date, caloric restriction (CR) appears to be the most effective intervention strategy to improve mitochondrial turnover in aging organisms. The development of pharmacological mimetics of CR has gained attention as an attractive and potentially feasible approach to mimic the CR phenotype. Polyphenols, ubiquitously present in fruits and vegetables, have emerged as well-tolerated CR mimetics that target mitochondrial turnover. Here, we discuss the molecular mechanisms that orchestrate mitochondrial biogenesis and mitophagy, and we summarize the current knowledge of how CR promotes mitochondrial maintenance and to what extent different polyphenols may mimic CR and coordinate mitochondrial biogenesis and clearance.
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Affiliation(s)
- Sergio Davinelli
- Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA, USA; Department of Medicine and Health Sciences 'V. Tiberio', University of Molise, Campobasso, Italy. @hsph.harvard.edu
| | - Diego De Stefani
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Immaculata De Vivo
- Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Giovanni Scapagnini
- Department of Medicine and Health Sciences 'V. Tiberio', University of Molise, Campobasso, Italy
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15
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Hausenloy DJ, Schulz R, Girao H, Kwak BR, De Stefani D, Rizzuto R, Bernardi P, Di Lisa F. Mitochondrial ion channels as targets for cardioprotection. J Cell Mol Med 2020; 24:7102-7114. [PMID: 32490600 PMCID: PMC7339171 DOI: 10.1111/jcmm.15341] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 03/31/2020] [Accepted: 04/12/2020] [Indexed: 12/14/2022] Open
Abstract
Acute myocardial infarction (AMI) and the heart failure (HF) that often result remain the leading causes of death and disability worldwide. As such, new therapeutic targets need to be discovered to protect the myocardium against acute ischaemia/reperfusion (I/R) injury in order to reduce myocardial infarct (MI) size, preserve left ventricular function and prevent the onset of HF. Mitochondrial dysfunction during acute I/R injury is a critical determinant of cell death following AMI, and therefore, ion channels in the inner mitochondrial membrane, which are known to influence cell death and survival, provide potential therapeutic targets for cardioprotection. In this article, we review the role of mitochondrial ion channels, which are known to modulate susceptibility to acute myocardial I/R injury, and we explore their potential roles as therapeutic targets for reducing MI size and preventing HF following AMI.
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Affiliation(s)
- Derek J. Hausenloy
- Cardiovascular & Metabolic Disorders ProgramDuke‐National University of Singapore Medical SchoolSingaporeSingapore
- National Heart Research Institute SingaporeNational Heart CentreSingaporeSingapore
- Yong Loo Lin School of MedicineNational University SingaporeSingaporeSingapore
- The Hatter Cardiovascular InstituteUniversity College LondonLondonUK
- Cardiovascular Research CenterCollege of Medical and Health SciencesAsia UniversityTaichung CityTaiwan
| | - Rainer Schulz
- Institute of PhysiologyJustus‐Liebig University GiessenGiessenGermany
| | - Henrique Girao
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of MedicineUniversity of CoimbraCoimbraPortugal
- Center for Innovative Biomedicine and Biotechnology (CIBB)University of CoimbraCoimbraPortugal
- Clinical Academic Centre of CoimbraCACCCoimbraPortugal
| | - Brenda R. Kwak
- Department of Pathology and ImmunologyUniversity of GenevaGenevaSwitzerland
| | - Diego De Stefani
- Department of Biomedical SciencesUniversity of PadovaPadovaItaly
| | - Rosario Rizzuto
- Department of Biomedical SciencesUniversity of PadovaPadovaItaly
| | - Paolo Bernardi
- Department of Biomedical SciencesUniversity of PadovaPadovaItaly
- CNR Neuroscience InstitutePadovaItaly
| | - Fabio Di Lisa
- Department of Biomedical SciencesUniversity of PadovaPadovaItaly
- CNR Neuroscience InstitutePadovaItaly
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16
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Larrea D, Pera M, Gonnelli A, Quintana-Cabrera R, Akman HO, Guardia-Laguarta C, Velasco KR, Area-Gomez E, Dal Bello F, De Stefani D, Horvath R, Shy ME, Schon EA, Giacomello M. MFN2 mutations in Charcot-Marie-Tooth disease alter mitochondria-associated ER membrane function but do not impair bioenergetics. Hum Mol Genet 2020; 28:1782-1800. [PMID: 30649465 PMCID: PMC6522073 DOI: 10.1093/hmg/ddz008] [Citation(s) in RCA: 65] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Revised: 11/27/2018] [Accepted: 12/31/2018] [Indexed: 12/23/2022] Open
Abstract
Charcot-Marie-Tooth disease (CMT) type 2A is a form of peripheral neuropathy, due almost exclusively to dominant mutations in the nuclear gene encoding the mitochondrial protein mitofusin-2 (MFN2). However, there is no understanding of the relationship of clinical phenotype to genotype. MFN2 has two functions: it promotes inter-mitochondrial fusion and mediates endoplasmic reticulum (ER)-mitochondrial tethering at mitochondria-associated ER membranes (MAM). MAM regulates a number of key cellular functions, including lipid and calcium homeostasis, and mitochondrial behavior. To date, no studies have been performed to address whether mutations in MFN2 in CMT2A patient cells affect MAM function, which might provide insight into pathogenesis. Using fibroblasts from three CMT2AMFN2 patients with different mutations in MFN2, we found that some, but not all, examined aspects of ER-mitochondrial connectivity and of MAM function were indeed altered, and correlated with disease severity. Notably, however, respiratory chain function in those cells was unimpaired. Our results suggest that CMT2AMFN2 is a MAM-related disorder but is not a respiratory chain-deficiency disease. The alterations in MAM function described here could also provide insight into the pathogenesis of other forms of CMT.
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Affiliation(s)
- Delfina Larrea
- Department of Neurology, Columbia University Medical Center, New York, NY, USA
| | - Marta Pera
- Department of Neurology, Columbia University Medical Center, New York, NY, USA
| | | | | | - H Orhan Akman
- Department of Neurology, Columbia University Medical Center, New York, NY, USA
| | | | - Kevin R Velasco
- Department of Neurology, Columbia University Medical Center, New York, NY, USA
| | - Estela Area-Gomez
- Department of Neurology, Columbia University Medical Center, New York, NY, USA
| | | | | | - Rita Horvath
- Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK
| | - Michael E Shy
- Department of Neurology, University of Iowa, Iowa City, IA, USA
| | - Eric A Schon
- Department of Neurology, Columbia University Medical Center, New York, NY, USA.,Department of Genetics and Development, Columbia University Medical Center, New York, NY, USA
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17
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18
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19
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Mazzola C, D’orsi B, Rizzuto R, De Stefani D. Early dysfunction of astrocytic Ca2+ signaling in Alzheimer's Disease. IBRO Rep 2019. [DOI: 10.1016/j.ibror.2019.07.800] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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20
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D’orsi B, Galla L, Greotti E, Beamer E, Engel T, De Stefani D, Pozzan T, Rizzuto R. Targeting mitochondrial calcium to fight neurological deficits: Role of the MCU in the pathogenesis of Alzheimer's disease and status epilepticus. IBRO Rep 2019. [DOI: 10.1016/j.ibror.2019.07.1169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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21
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Paggio A, Checchetto V, Campo A, Menabò R, Di Marco G, Di Lisa F, Szabo I, Rizzuto R, De Stefani D. Identification of an ATP-sensitive potassium channel in mitochondria. Nature 2019; 572:609-613. [PMID: 31435016 PMCID: PMC6726485 DOI: 10.1038/s41586-019-1498-3] [Citation(s) in RCA: 159] [Impact Index Per Article: 31.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Accepted: 07/25/2019] [Indexed: 11/09/2022]
Abstract
Mitochondria provide chemical energy for endoergonic reactions in the form of ATP, and their activity must meet cellular energy requirements, but the mechanisms that link organelle performance to ATP levels are poorly understood. Here we confirm the existence of a protein complex localized in mitochondria that mediates ATP-dependent potassium currents (that is, mitoKATP). We show that-similar to their plasma membrane counterparts-mitoKATP channels are composed of pore-forming and ATP-binding subunits, which we term MITOK and MITOSUR, respectively. In vitro reconstitution of MITOK together with MITOSUR recapitulates the main properties of mitoKATP. Overexpression of MITOK triggers marked organelle swelling, whereas the genetic ablation of this subunit causes instability in the mitochondrial membrane potential, widening of the intracristal space and decreased oxidative phosphorylation. In a mouse model, the loss of MITOK suppresses the cardioprotection that is elicited by pharmacological preconditioning induced by diazoxide. Our results indicate that mitoKATP channels respond to the cellular energetic status by regulating organelle volume and function, and thereby have a key role in mitochondrial physiology and potential effects on several pathological processes.
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Affiliation(s)
- Angela Paggio
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | | | - Antonio Campo
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | | | - Giulia Di Marco
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Fabio Di Lisa
- Department of Biomedical Sciences, University of Padova, Padova, Italy.,CNR Institute of Neuroscience, Padova, Italy
| | - Ildiko Szabo
- Department of Biology, University of Padova, Padova, Italy.,CNR Institute of Neuroscience, Padova, Italy
| | - Rosario Rizzuto
- Department of Biomedical Sciences, University of Padova, Padova, Italy.
| | - Diego De Stefani
- Department of Biomedical Sciences, University of Padova, Padova, Italy.
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22
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Carnevale D, Facchinello N, Iodice D, Bizzotto D, Perrotta M, De Stefani D, Pallante F, Carnevale L, Ricciardi F, Cifelli G, Da Ros F, Casaburo M, Fardella S, Bonaldo P, Innocenzi G, Rizzuto R, Braghetta P, Lembo G, Bressan GM. Loss of EMILIN-1 Enhances Arteriolar Myogenic Tone Through TGF-β (Transforming Growth Factor-β)–Dependent Transactivation of EGFR (Epidermal Growth Factor Receptor) and Is Relevant for Hypertension in Mice and Humans. Arterioscler Thromb Vasc Biol 2018; 38:2484-2497. [DOI: 10.1161/atvbaha.118.311115] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Affiliation(s)
- Daniela Carnevale
- From the Department of Molecular Medicine, Sapienza University of Rome, Italy (D.C., M.P., G.L.)
- Department of Angiocardioneurology and Translational Medicine (D.C., D.I., F.P., L.C., G.C., M.C., S.F., G.L.), IRCCS Neuromed, Pozzilli, Italy
| | - Nicola Facchinello
- Department of Molecular Medicine (N.F., D.B., F.D.R., P. Bonaldo, P. Braghetta, G.M.B.), University of Padova, Italy
| | - Daniele Iodice
- Department of Angiocardioneurology and Translational Medicine (D.C., D.I., F.P., L.C., G.C., M.C., S.F., G.L.), IRCCS Neuromed, Pozzilli, Italy
| | - Dario Bizzotto
- Department of Molecular Medicine (N.F., D.B., F.D.R., P. Bonaldo, P. Braghetta, G.M.B.), University of Padova, Italy
| | - Marialuisa Perrotta
- From the Department of Molecular Medicine, Sapienza University of Rome, Italy (D.C., M.P., G.L.)
| | - Diego De Stefani
- Department of Biomedical Sciences (D.D.S., R.R.), University of Padova, Italy
| | - Fabio Pallante
- Department of Angiocardioneurology and Translational Medicine (D.C., D.I., F.P., L.C., G.C., M.C., S.F., G.L.), IRCCS Neuromed, Pozzilli, Italy
| | - Lorenzo Carnevale
- Department of Angiocardioneurology and Translational Medicine (D.C., D.I., F.P., L.C., G.C., M.C., S.F., G.L.), IRCCS Neuromed, Pozzilli, Italy
| | - Franco Ricciardi
- Department of Neurosurgery (F.R., G.I.), IRCCS Neuromed, Pozzilli, Italy
| | - Giuseppe Cifelli
- Department of Angiocardioneurology and Translational Medicine (D.C., D.I., F.P., L.C., G.C., M.C., S.F., G.L.), IRCCS Neuromed, Pozzilli, Italy
| | - Francesco Da Ros
- Department of Molecular Medicine (N.F., D.B., F.D.R., P. Bonaldo, P. Braghetta, G.M.B.), University of Padova, Italy
| | - Manuel Casaburo
- Department of Angiocardioneurology and Translational Medicine (D.C., D.I., F.P., L.C., G.C., M.C., S.F., G.L.), IRCCS Neuromed, Pozzilli, Italy
| | - Stefania Fardella
- Department of Angiocardioneurology and Translational Medicine (D.C., D.I., F.P., L.C., G.C., M.C., S.F., G.L.), IRCCS Neuromed, Pozzilli, Italy
| | - Paolo Bonaldo
- Department of Molecular Medicine (N.F., D.B., F.D.R., P. Bonaldo, P. Braghetta, G.M.B.), University of Padova, Italy
| | | | - Rosario Rizzuto
- Department of Biomedical Sciences (D.D.S., R.R.), University of Padova, Italy
| | - Paola Braghetta
- Department of Molecular Medicine (N.F., D.B., F.D.R., P. Bonaldo, P. Braghetta, G.M.B.), University of Padova, Italy
| | - Giuseppe Lembo
- From the Department of Molecular Medicine, Sapienza University of Rome, Italy (D.C., M.P., G.L.)
- Department of Angiocardioneurology and Translational Medicine (D.C., D.I., F.P., L.C., G.C., M.C., S.F., G.L.), IRCCS Neuromed, Pozzilli, Italy
| | - Giorgio M. Bressan
- Department of Molecular Medicine (N.F., D.B., F.D.R., P. Bonaldo, P. Braghetta, G.M.B.), University of Padova, Italy
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23
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Gherardi G, Nogara L, Ciciliot S, Fadini GP, Blaauw B, Braghetta P, Bonaldo P, De Stefani D, Rizzuto R, Mammucari C. Loss of mitochondrial calcium uniporter rewires skeletal muscle metabolism and substrate preference. Cell Death Differ 2018; 26:362-381. [PMID: 30232375 DOI: 10.1038/s41418-018-0191-7] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Revised: 08/07/2018] [Accepted: 08/10/2018] [Indexed: 11/10/2022] Open
Abstract
Skeletal muscle mitochondria readily accumulate Ca2+ in response to SR store-releasing stimuli thanks to the activity of the mitochondrial calcium uniporter (MCU), the highly selective channel responsible for mitochondrial Ca2+ uptake. MCU positively regulates myofiber size in physiological conditions and counteracts pathological loss of muscle mass. Here we show that skeletal muscle-specific MCU deletion inhibits myofiber mitochondrial Ca2+ uptake, impairs muscle force and exercise performance, and determines a slow to fast switch in MHC expression. Mitochondrial Ca2+ uptake is required for effective glucose oxidation, as demonstrated by the fact that in muscle-specific MCU-/- myofibers oxidative metabolism is impaired and glycolysis rate is increased. Although defective, mitochondrial activity is partially sustained by increased fatty acid (FA) oxidation. In MCU-/- myofibers, PDP2 overexpression drastically reduces FA dependency, demonstrating that decreased PDH activity is the main trigger of the metabolic rewiring of MCU-/- muscles. Accordingly, PDK4 overexpression in MCUfl/fl myofibers is sufficient to increase FA-dependent respiration. Finally, as a result of the muscle-specific MCU deletion, a systemic catabolic response impinging on both liver and adipose tissue metabolism occurs.
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Affiliation(s)
- Gaia Gherardi
- Department of Biomedical Sciences, University of Padova, 35131, Padova, Italy
| | - Leonardo Nogara
- Department of Biomedical Sciences, University of Padova, 35131, Padova, Italy
| | - Stefano Ciciliot
- Department of Medicine, University of Padova, 35128, Padova, Italy.,Venetian Institute of Molecular Medicine, 35129, Padova, Italy
| | - Gian Paolo Fadini
- Department of Medicine, University of Padova, 35128, Padova, Italy.,Venetian Institute of Molecular Medicine, 35129, Padova, Italy
| | - Bert Blaauw
- Department of Biomedical Sciences, University of Padova, 35131, Padova, Italy.,Venetian Institute of Molecular Medicine, 35129, Padova, Italy
| | - Paola Braghetta
- Department of Molecular Medicine, University of Padova, 35131, Padova, Italy
| | - Paolo Bonaldo
- Department of Molecular Medicine, University of Padova, 35131, Padova, Italy
| | - Diego De Stefani
- Department of Biomedical Sciences, University of Padova, 35131, Padova, Italy
| | - Rosario Rizzuto
- Department of Biomedical Sciences, University of Padova, 35131, Padova, Italy.
| | - Cristina Mammucari
- Department of Biomedical Sciences, University of Padova, 35131, Padova, Italy.
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24
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Cieri D, Vicario M, Vallese F, D'Orsi B, Berto P, Grinzato A, Catoni C, De Stefani D, Rizzuto R, Brini M, Calì T. Tau localises within mitochondrial sub-compartments and its caspase cleavage affects ER-mitochondria interactions and cellular Ca 2+ handling. Biochim Biophys Acta Mol Basis Dis 2018; 1864:3247-3256. [PMID: 30006151 DOI: 10.1016/j.bbadis.2018.07.011] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Revised: 06/16/2018] [Accepted: 07/06/2018] [Indexed: 01/21/2023]
Abstract
Intracellular neurofibrillary tangles (NFT) composed by tau and extracellular amyloid beta (Aβ) plaques accumulate in Alzheimer's disease (AD) and contribute to neuronal dysfunction. Mitochondrial dysfunction and neurodegeneration are increasingly considered two faces of the same coin and an early pathological event in AD. Compelling evidence indicates that tau and mitochondria are closely linked and suggests that tau-dependent modulation of mitochondrial functions might be a trigger for the neurodegeneration process; however, whether this occurs either directly or indirectly is not clear. Furthermore, whether tau influences cellular Ca2+ handling and ER-mitochondria cross-talk is yet to be explored. Here, by focusing on wt tau, either full-length (2N4R) or the caspase 3-cleaved form truncated at the C-terminus (2N4RΔC20), we examined the above-mentioned aspects. Using new genetically encoded split-GFP-based tools and organelle-targeted aequorin probes, we assessed: i) tau distribution within the mitochondrial sub-compartments; ii) the effect of tau on the short- (8-10 nm) and the long- (40-50 nm) range ER-mitochondria interactions; and iii) the effect of tau on cytosolic, ER and mitochondrial Ca2+ homeostasis. Our results indicate that a fraction of tau is found at the outer mitochondrial membrane (OMM) and within the inner mitochondrial space (IMS), suggesting a potential tau-dependent regulation of mitochondrial functions. The ER Ca2+ content and the short-range ER-mitochondria interactions were selectively affected by the expression of the caspase 3-cleaved 2N4RΔC20 tau, indicating that Ca2+ mis-handling and defects in the ER-mitochondria communications might be an important pathological event in tau-related dysfunction and thereby contributing to neurodegeneration. Finally, our data provide new insights into the molecular mechanisms underlying tauopathies.
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Affiliation(s)
- Domenico Cieri
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Mattia Vicario
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Francesca Vallese
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Beatrice D'Orsi
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Paola Berto
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | | | | | - Diego De Stefani
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Rosario Rizzuto
- Department of Biomedical 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; Padova Neuroscience Center (PNC), University of Padova, Padova, Italy.
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25
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Díaz-Vegas AR, Cordova A, Valladares D, Llanos P, Hidalgo C, Gherardi G, De Stefani D, Mammucari C, Rizzuto R, Contreras-Ferrat A, Jaimovich E. Mitochondrial Calcium Increase Induced by RyR1 and IP3R Channel Activation After Membrane Depolarization Regulates Skeletal Muscle Metabolism. Front Physiol 2018; 9:791. [PMID: 29988564 PMCID: PMC6026899 DOI: 10.3389/fphys.2018.00791] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Accepted: 06/06/2018] [Indexed: 11/13/2022] Open
Abstract
Aim: We hypothesize that both type-1 ryanodine receptor (RyR1) and IP3-receptor (IP3R) calcium channels are necessary for the mitochondrial Ca2+ increase caused by membrane depolarization induced by potassium (or by electrical stimulation) of single skeletal muscle fibers; this calcium increase would couple muscle fiber excitation to an increase in metabolic output from mitochondria (excitation-metabolism coupling). Methods: Mitochondria matrix and cytoplasmic Ca2+ levels were evaluated in fibers isolated from flexor digitorium brevis muscle using plasmids for the expression of a mitochondrial Ca2+ sensor (CEPIA3mt) or a cytoplasmic Ca2+ sensor (RCaMP). The role of intracellular Ca2+ channels was evaluated using both specific pharmacological inhibitors (xestospongin B for IP3R and Dantrolene for RyR1) and a genetic approach (shIP3R1-RFP). O2 consumption was detected using Seahorse Extracellular Flux Analyzer. Results: In isolated muscle fibers cell membrane depolarization increased both cytoplasmic and mitochondrial Ca2+ levels. Mitochondrial Ca2+ uptake required functional inositol IP3R and RyR1 channels. Inhibition of either channel decreased basal O2 consumption rate but only RyR1 inhibition decreased ATP-linked O2 consumption. Cell membrane depolarization-induced Ca2+ signals in sub-sarcolemmal mitochondria were accompanied by a reduction in mitochondrial membrane potential; Ca2+ signals propagated toward intermyofibrillar mitochondria, which displayed increased membrane potential. These results are compatible with slow, Ca2+-dependent propagation of mitochondrial membrane potential from the surface toward the center of the fiber. Conclusion: Ca2+-dependent changes in mitochondrial membrane potential have different kinetics in the surface vs. the center of the fiber; these differences are likely to play a critical role in the control of mitochondrial metabolism, both at rest and after membrane depolarization as part of an “excitation-metabolism” coupling process in skeletal muscle fibers.
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Affiliation(s)
- Alexis R Díaz-Vegas
- Muscle Physiology Laboratory, Center of Studies in Exercise, Metabolism and Cancer, Institute of Biomedical Sciences, Universidad de Chile, Santiago, Chile
| | - Alex Cordova
- Biomedical Neuroscience Institute, Center of Studies in Exercise, Metabolism and Cancer, Institute of Biomedical Sciences, Universidad de Chile, Santiago, Chile
| | - Denisse Valladares
- Muscle Physiology Laboratory, Center of Studies in Exercise, Metabolism and Cancer, Institute of Biomedical Sciences, Universidad de Chile, Santiago, Chile.,Exercise and Movement Science Laboratory, Universidad Finis Terrae, Santiago, Chile
| | - Paola Llanos
- Muscle Physiology Laboratory, Center of Studies in Exercise, Metabolism and Cancer, Institute of Biomedical Sciences, Universidad de Chile, Santiago, Chile.,Institute for Research in Dental Science, Universidad de Chile, Santiago, Chile
| | - Cecilia Hidalgo
- Biomedical Neuroscience Institute, Center of Studies in Exercise, Metabolism and Cancer, Institute of Biomedical Sciences, Universidad de Chile, Santiago, Chile
| | - Gaia Gherardi
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Diego De Stefani
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | | | - Rosario Rizzuto
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Ariel Contreras-Ferrat
- Muscle Physiology Laboratory, Center of Studies in Exercise, Metabolism and Cancer, Institute of Biomedical Sciences, Universidad de Chile, Santiago, Chile
| | - Enrique Jaimovich
- Muscle Physiology Laboratory, Center of Studies in Exercise, Metabolism and Cancer, Institute of Biomedical Sciences, Universidad de Chile, Santiago, Chile
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26
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Patron M, Granatiero V, Espino J, Rizzuto R, De Stefani D. MICU3 is a tissue-specific enhancer of mitochondrial calcium uptake. Cell Death Differ 2018; 26:179-195. [PMID: 29725115 DOI: 10.1038/s41418-018-0113-8] [Citation(s) in RCA: 130] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Revised: 03/05/2018] [Accepted: 03/19/2018] [Indexed: 01/14/2023] Open
Abstract
The versatility and universality of Ca2+ as intracellular messenger is guaranteed by the compartmentalization of changes in [Ca2+]. In this context, mitochondrial Ca2+ plays a central role, by regulating both specific organelle functions and global cellular events. This versatility is also guaranteed by a cell type-specific Ca2+ signaling toolkit controlling specific cellular functions. Accordingly, mitochondrial Ca2+ uptake is mediated by a multimolecular structure, the MCU complex, which differs among various tissues. Its activity is indeed controlled by different components that cooperate to modulate specific channeling properties. We here investigate the role of MICU3, an EF-hand containing protein expressed at high levels, especially in brain. We show that MICU3 forms a disulfide bond-mediated dimer with MICU1, but not with MICU2, and it acts as enhancer of MCU-dependent mitochondrial Ca2+ uptake. Silencing of MICU3 in primary cortical neurons impairs Ca2+ signals elicited by synaptic activity, thus suggesting a specific role in regulating neuronal function.
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Affiliation(s)
- Maria Patron
- Department of Biomedical Sciences, University of Padova, Via Ugo Bassi 58B, 35131, Padova, Italy.,Max Planck Institute for Biology and Aging, Cologne, Germany.,Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), Center for Molecular Medicine (CMMC), University of Cologne, Cologne, Germany
| | - Veronica Granatiero
- Department of Biomedical Sciences, University of Padova, Via Ugo Bassi 58B, 35131, Padova, Italy.,Feil Family Brain and Mind Research Institute, Weill Cornell Medical College, 401 East 61st Street, New York, NY, 10065, United States
| | - Javier Espino
- Department of Biomedical Sciences, University of Padova, Via Ugo Bassi 58B, 35131, Padova, Italy
| | - Rosario Rizzuto
- Department of Biomedical Sciences, University of Padova, Via Ugo Bassi 58B, 35131, Padova, Italy.
| | - Diego De Stefani
- Department of Biomedical Sciences, University of Padova, Via Ugo Bassi 58B, 35131, Padova, Italy.
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27
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Austin S, Tavakoli M, Pfeiffer C, Seifert J, Mattarei A, De Stefani D, Zoratti M, Nowikovsky K. LETM1-Mediated K + and Na + Homeostasis Regulates Mitochondrial Ca 2+ Efflux. Front Physiol 2017; 8:839. [PMID: 29204122 PMCID: PMC5698270 DOI: 10.3389/fphys.2017.00839] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Accepted: 10/09/2017] [Indexed: 12/13/2022] Open
Abstract
Ca2+ transport across the inner membrane of mitochondria (IMM) is of major importance for their functions in bioenergetics, cell death and signaling. It is therefore tightly regulated. It has been recently proposed that LETM1—an IMM protein with a crucial role in mitochondrial K+/H+ exchange and volume homeostasis—also acts as a Ca2+/H+ exchanger. Here we show for the first time that lowering LETM1 gene expression by shRNA hampers mitochondrial K+/H+ and Na+/H+ exchange. Decreased exchange activity resulted in matrix K+ accumulation in these mitochondria. Furthermore, LETM1 depletion selectively decreased Na+/Ca2+ exchange mediated by NCLX, as observed in the presence of ruthenium red, a blocker of the Mitochondrial Ca2+ Uniporter (MCU). These data confirm a key role of LETM1 in monovalent cation homeostasis, and suggest that the effects of its modulation on mitochondrial transmembrane Ca2+ fluxes may reflect those on Na+/H+ exchange activity.
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Affiliation(s)
- Shane Austin
- Department of Internal Medicine I and Comprehensive Cancer Center, Medical University of Vienna, Vienna, Austria
| | - Mojtaba Tavakoli
- Department of Internal Medicine I and Comprehensive Cancer Center, Medical University of Vienna, Vienna, Austria
| | - Christina Pfeiffer
- Department of Internal Medicine I and Comprehensive Cancer Center, Medical University of Vienna, Vienna, Austria
| | - Julia Seifert
- Department of Internal Medicine I and Comprehensive Cancer Center, Medical University of Vienna, Vienna, Austria
| | - Andrea Mattarei
- Department of Chemical Sciences, Università di Padova, Padova, Italy
| | - Diego De Stefani
- Department of Biomedical Sciences, Università di Padova, Padova, Italy
| | - Mario Zoratti
- Department of Biomedical Sciences, Università di Padova, Padova, Italy.,Institute of Neuroscience (CNR), Padova, Italy
| | - Karin Nowikovsky
- Department of Internal Medicine I and Comprehensive Cancer Center, Medical University of Vienna, Vienna, Austria
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28
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Naon D, Zaninello M, Giacomello M, Varanita T, Grespi F, Lakshminaranayan S, Serafini A, Semenzato M, Herkenne S, Hernández-Alvarez MI, Zorzano A, De Stefani D, Dorn GW, Scorrano L. Reply to Filadi et al.: Does Mitofusin 2 tether or separate endoplasmic reticulum and mitochondria? Proc Natl Acad Sci U S A 2017; 114:E2268-E2269. [PMID: 28289205 PMCID: PMC5373396 DOI: 10.1073/pnas.1618610114] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Deborah Naon
- Department of Biology, University of Padua, 35121 Padua, Italy
- Department of Biomedical Sciences, University of Padua, 35121 Padua, Italy
| | - Marta Zaninello
- Department of Biology, University of Padua, 35121 Padua, Italy
- Dulbecco-Telethon Institute, Venetian Institute of Molecular Medicine, 35129 Padua, Italy
- Fondazione S. Lucia Istituto di Recovero e Cura a Carattere Scientifico, 00161 Rome, Italy
| | - Marta Giacomello
- Department of Biology, University of Padua, 35121 Padua, Italy
- Dulbecco-Telethon Institute, Venetian Institute of Molecular Medicine, 35129 Padua, Italy
| | - Tatiana Varanita
- Department of Biology, University of Padua, 35121 Padua, Italy
- Dulbecco-Telethon Institute, Venetian Institute of Molecular Medicine, 35129 Padua, Italy
| | - Francesca Grespi
- Department of Biology, University of Padua, 35121 Padua, Italy
- Dulbecco-Telethon Institute, Venetian Institute of Molecular Medicine, 35129 Padua, Italy
| | - Sowmya Lakshminaranayan
- Department of Biology, University of Padua, 35121 Padua, Italy
- Fondazione S. Lucia Istituto di Recovero e Cura a Carattere Scientifico, 00161 Rome, Italy
| | - Annalisa Serafini
- Department of Biology, University of Padua, 35121 Padua, Italy
- Dulbecco-Telethon Institute, Venetian Institute of Molecular Medicine, 35129 Padua, Italy
| | - Martina Semenzato
- Department of Biology, University of Padua, 35121 Padua, Italy
- Dulbecco-Telethon Institute, Venetian Institute of Molecular Medicine, 35129 Padua, Italy
| | - Stephanie Herkenne
- Department of Biology, University of Padua, 35121 Padua, Italy
- Dulbecco-Telethon Institute, Venetian Institute of Molecular Medicine, 35129 Padua, Italy
| | | | - Antonio Zorzano
- Institute for Research in Biomedicine, 08028 Barcelona, Spain
| | - Diego De Stefani
- Department of Biomedical Sciences, University of Padua, 35121 Padua, Italy
| | - Gerald W Dorn
- Department of Internal Medicine, Center for Pharmacogenomics, Washington University School of Medicine, St. Louis, MO 63110
| | - Luca Scorrano
- Department of Biology, University of Padua, 35121 Padua, Italy;
- Dulbecco-Telethon Institute, Venetian Institute of Molecular Medicine, 35129 Padua, Italy
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29
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Abstract
In the last 5 years, most of the molecules that control mitochondrial Ca(2+) homeostasis have been finally identified. Mitochondrial Ca(2+) uptake is mediated by the Mitochondrial Calcium Uniporter (MCU) complex, a macromolecular structure that guarantees Ca(2+) accumulation inside mitochondrial matrix upon increases in cytosolic Ca(2+). Conversely, Ca(2+) release is under the control of the Na(+)/Ca(2+) exchanger, encoded by the NCLX gene, and of a H(+)/Ca(2+) antiporter, whose identity is still debated. The low affinity of the MCU complex, coupled to the activity of the efflux systems, protects cells from continuous futile cycles of Ca(2+) across the inner mitochondrial membrane and consequent massive energy dissipation. In this review, we discuss the basic principles that govern mitochondrial Ca(2+) homeostasis and the methods used to investigate the dynamics of Ca(2+) concentration within the organelles. We discuss the functional and structural role of the different molecules involved in mitochondrial Ca(2+) handling and their pathophysiological role.
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Affiliation(s)
- Diego De Stefani
- Department of Biomedical Sciences, University of Padova, 35121 Padova, Italy; , ,
| | - Rosario Rizzuto
- Department of Biomedical Sciences, University of Padova, 35121 Padova, Italy; , , .,National Research Council (CNR) Neuroscience Institute, 35121 Padova, Italy
| | - Tullio Pozzan
- Department of Biomedical Sciences, University of Padova, 35121 Padova, Italy; , , .,National Research Council (CNR) Neuroscience Institute, 35121 Padova, Italy.,Venetian Institute of Molecular Medicine, 35121 Padova, Italy
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30
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Paggio A, Checchetto V, Szabò I, Rizzuto R, De Stefani D. Novel Players in the Control of Mitochondrial Ion Homeostasis. Biophys J 2016. [DOI: 10.1016/j.bpj.2015.11.693] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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31
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Medina DL, Di Paola S, Peluso I, Armani A, De Stefani D, Venditti R, Montefusco S, Scotto-Rosato A, Prezioso C, Forrester A, Settembre C, Wang W, Gao Q, Xu H, Sandri M, Rizzuto R, De Matteis MA, Ballabio A. Lysosomal calcium signalling regulates autophagy through calcineurin and TFEB. Nat Cell Biol 2015; 17:288-99. [PMID: 25720963 PMCID: PMC4801004 DOI: 10.1038/ncb3114] [Citation(s) in RCA: 906] [Impact Index Per Article: 100.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2014] [Accepted: 01/16/2015] [Indexed: 12/17/2022]
Abstract
The view of the lysosome as the terminal end of cellular catabolic pathways has been challenged by recent studies showing a central role of this organelle in the control of cell function. Here we show that a lysosomal Ca2+ signaling mechanism controls the activities of the phosphatase calcineurin and of its substrate TFEB, a master transcriptional regulator of lysosomal biogenesis and autophagy. Lysosomal Ca2+ release via mucolipin 1 (MCOLN1) activates calcineurin, which binds and de-phosphorylates TFEB, thus promoting its nuclear translocation. Genetic and pharmacological inhibition of calcineurin suppressed TFEB activity during starvation and physical exercise, while calcineurin overexpression and constitutive activation had the opposite effect. Induction of autophagy and lysosomal biogenesis via TFEB required MCOLN1-mediated calcineurin activation, linking lysosomal calcium signaling to both calcineurin regulation and autophagy induction. Thus, the lysosome reveals itself as a hub for the signaling pathways that regulate cellular homeostasis.
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32
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De Stefani D, Patron M, Rizzuto R. Structure and function of the mitochondrial calcium uniporter complex. Biochim Biophys Acta 2015; 1853:2006-11. [PMID: 25896525 DOI: 10.1016/j.bbamcr.2015.04.008] [Citation(s) in RCA: 133] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2014] [Revised: 04/10/2015] [Accepted: 04/11/2015] [Indexed: 01/27/2023]
Abstract
The mitochondrial calcium uniporter (MCU) is the critical protein of the inner mitochondrial membrane mediating the electrophoretic Ca²⁺ uptake into the matrix. It plays a fundamental role in the shaping of global calcium signaling and in the control of aerobic metabolism as well as apoptosis. Two features of mitochondrial calcium signaling have been known for a long time: i) mitochondrial Ca²⁺ uptake widely varies among cells and tissues, and ii) channel opening strongly relies on the extramitochondrial Ca²⁺ concentration, with low activity at resting [Ca²⁺] and high capacity as soon as calcium signaling is activated. Such complexity requires a specialized molecular machinery, with several primary components can be variably gathered together in order to match energy demands and protect from toxic stimuli. In line with this, MCU is now recognized to be part of a macromolecular complex known as the MCU complex. Our understanding of the structure and function of the MCU complex is now growing promptly, revealing an unexpected complexity that highlights the pleiotropic role of mitochondrial Ca²⁺ signals. This article is part of a Special Issue entitled: 13th European Symposium on Calcium.
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Affiliation(s)
| | - Maria Patron
- Department of Biomedical Sciences, University of Padova, Italy
| | - Rosario Rizzuto
- Department of Biomedical Sciences, University of Padova, Italy
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33
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Mammucari C, Gherardi G, Zamparo I, Raffaello A, Boncompagni S, Chemello F, Cagnin S, Braga A, Zanin S, Pallafacchina G, Zentilin L, Sandri M, De Stefani D, Protasi F, Lanfranchi G, Rizzuto R. The mitochondrial calcium uniporter controls skeletal muscle trophism in vivo. Cell Rep 2015; 10:1269-79. [PMID: 25732818 DOI: 10.1016/j.celrep.2015.01.056] [Citation(s) in RCA: 135] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Revised: 12/23/2014] [Accepted: 01/24/2015] [Indexed: 12/18/2022] Open
Abstract
Muscle atrophy contributes to the poor prognosis of many pathophysiological conditions, but pharmacological therapies are still limited. Muscle activity leads to major swings in mitochondrial [Ca(2+)], which control aerobic metabolism, cell death, and survival pathways. We investigated in vivo the effects of mitochondrial Ca(2+) homeostasis in skeletal muscle function and trophism by overexpressing or silencing the mitochondrial calcium uniporter (MCU). The results demonstrate that in both developing and adult muscles, MCU-dependent mitochondrial Ca(2+) uptake has a marked trophic effect that does not depend on aerobic control but impinges on two major hypertrophic pathways of skeletal muscle, PGC-1α4 and IGF1-Akt/PKB. In addition, MCU overexpression protects from denervation-induced atrophy. These data reveal a novel Ca(2+)-dependent organelle-to-nucleus signaling route that links mitochondrial function to the control of muscle mass and may represent a possible pharmacological target in conditions of muscle loss.
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Affiliation(s)
- Cristina Mammucari
- Department of Biomedical Sciences, University of Padua, Padua 35131, Italy.
| | - Gaia Gherardi
- Department of Biomedical Sciences, University of Padua, Padua 35131, Italy
| | - Ilaria Zamparo
- Department of Biomedical Sciences, University of Padua, Padua 35131, Italy
| | - Anna Raffaello
- Department of Biomedical Sciences, University of Padua, Padua 35131, Italy
| | - Simona Boncompagni
- Ce.S.I. (Center for Research on Ageing) and D.N.I.C.S. (Department of Neuroscience, Imaging and Clinical Sciences), University "G. D'Annunzio" of Chieti, Chieti 66100, Italy
| | - Francesco Chemello
- Department of Biology and CRIBI Biotechnology Center, University of Padua, Padua 35131, Italy
| | - Stefano Cagnin
- Department of Biology and CRIBI Biotechnology Center, University of Padua, Padua 35131, Italy
| | - Alessandra Braga
- Department of Biomedical Sciences, University of Padua, Padua 35131, Italy
| | - Sofia Zanin
- Department of Biomedical Sciences, University of Padua, Padua 35131, Italy
| | - Giorgia Pallafacchina
- Department of Biomedical Sciences, University of Padua, Padua 35131, Italy; Neuroscience Institute, National Research Council, Padua 35131, Italy
| | - Lorena Zentilin
- International Centre for Genetic Engineering and Biotechnology (ICGEB), Trieste 34159, Italy
| | - Marco Sandri
- Department of Biomedical Sciences, University of Padua, Padua 35131, Italy; Neuroscience Institute, National Research Council, Padua 35131, Italy; Dulbecco Telethon Institute at Venetian Institute of Molecular Medicine, Padua 35129, Italy; Telethon Institute of Genetics and Medicine (TIGEM), Naples 80131, Italy
| | - Diego De Stefani
- Department of Biomedical Sciences, University of Padua, Padua 35131, Italy
| | - Feliciano Protasi
- Ce.S.I. (Center for Research on Ageing) and D.N.I.C.S. (Department of Neuroscience, Imaging and Clinical Sciences), University "G. D'Annunzio" of Chieti, Chieti 66100, Italy
| | - Gerolamo Lanfranchi
- Department of Biology and CRIBI Biotechnology Center, University of Padua, Padua 35131, Italy
| | - Rosario Rizzuto
- Department of Biomedical Sciences, University of Padua, Padua 35131, Italy; Neuroscience Institute, National Research Council, Padua 35131, Italy.
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Abstract
The recently identified Mitochondrial Calcium Uniporter (MCU) is the protein of the inner mitochondrial membrane responsible for Ca(2+) uptake into the matrix, which plays a role in the control of cellular signaling, aerobic metabolism and apoptosis. At least two properties of mitochondrial calcium signaling are well defined: (i) mitochondrial Ca(2+) uptake varies greatly among different cells and tissues, and (ii) channel opening is strongly affected by extramitochondrial Ca(2+) concentration, with low activity at resting and high capacity after cellular stimulation. It is now becoming clear that these features of the mitochondrial Ca(2+) uptake machinery are not embedded in the MCU protein itself, but are rather due to the contribution of several MCU interactors. The list of the components of the MCU complex is indeed rapidly growing, thus revealing an unexpected complexity that highlights the pleiotropic role of mitochondrial calcium signaling.
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Affiliation(s)
- Diego De Stefani
- Department of Biomedical Sciences, University of Padova and CNR Neuroscience Institute, Padova, Italy.
| | - Rosario Rizzuto
- Department of Biomedical Sciences, University of Padova and CNR Neuroscience Institute, Padova, Italy.
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Rossato M, Granzotto M, Macchi V, Porzionato A, Petrelli L, Calcagno A, Vencato J, De Stefani D, Silvestrin V, Rizzuto R, Bassetto F, De Caro R, Vettor R. Human white adipocytes express the cold receptor TRPM8 which activation induces UCP1 expression, mitochondrial activation and heat production. Mol Cell Endocrinol 2014; 383:137-46. [PMID: 24342393 DOI: 10.1016/j.mce.2013.12.005] [Citation(s) in RCA: 82] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2013] [Revised: 11/10/2013] [Accepted: 12/09/2013] [Indexed: 10/25/2022]
Abstract
Mammals possess two types of adipose tissue, white (WAT) and brown (BAT). The uncoupling protein 1 (UCP1) is a hallmark of BAT, being the pivotal player for cold-induced thermogenesis. WAT can acquire BAT characteristics with up-regulation of UCP1 after cold exposure or adrenergic stimulation. In the present study we demonstrated that human white adipocytes express the cold-sensing receptor TRPM8 which activation by menthol and icilin induced a rise in [Ca²⁺](i) and UCP1 expression, increased mitochondrial membrane potential, glucose uptake and heat production. The induction of "brown-like" phenotype in human white adipocytes after TRPM8 activation was supported by ultrastructural morphological changes of mitochondrial morphology and of their intracellular localization, with no modifications of the genes regulating mitochondrial biogenesis. In conclusion human white adipocytes express the cold receptor TRPM8 which activation induces their "browning" supporting a possible role of this receptor in the control of adipose tissue metabolism and body energy balance.
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Affiliation(s)
- Marco Rossato
- Department of Medicine - DIMED, Clinica Medica 3, School of Medicine, University of Padova, Padova, Italy.
| | - Marnie Granzotto
- Department of Medicine - DIMED, Clinica Medica 3, School of Medicine, University of Padova, Padova, Italy
| | - Veronica Macchi
- Department of Molecular Medicine, Section of Anatomy, School of Medicine, University of Padova, Padova, Italy
| | - Andrea Porzionato
- Department of Molecular Medicine, Section of Anatomy, School of Medicine, University of Padova, Padova, Italy
| | - Lucia Petrelli
- Department of Molecular Medicine, Section of Anatomy, School of Medicine, University of Padova, Padova, Italy
| | - Alessandra Calcagno
- Department of Medicine - DIMED, Clinica Medica 3, School of Medicine, University of Padova, Padova, Italy
| | - Juri Vencato
- Department of Animal Medicine, Production and Health, University of Padova, Padova, Italy
| | - Diego De Stefani
- Department of Biomedical Sciences, School of Medicine, University of Padova, Padova, Italy
| | - Valentina Silvestrin
- Department of Medicine - DIMED, Clinica Medica 3, School of Medicine, University of Padova, Padova, Italy
| | - Rosario Rizzuto
- Department of Biomedical Sciences, School of Medicine, University of Padova, Padova, Italy
| | - Franco Bassetto
- Department of Neurosciences, Plastic Surgery Clinic, University of Padova, Padova, Italy
| | - Raffaele De Caro
- Department of Molecular Medicine, Section of Anatomy, School of Medicine, University of Padova, Padova, Italy
| | - Roberto Vettor
- Department of Medicine - DIMED, Clinica Medica 3, School of Medicine, University of Padova, Padova, Italy
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36
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Patron M, Checchetto V, Raffaello A, Teardo E, Vecellio Reane D, Mantoan M, Granatiero V, Szabò I, De Stefani D, Rizzuto R. MICU1 and MICU2 finely tune the mitochondrial Ca2+ uniporter by exerting opposite effects on MCU activity. Mol Cell 2014; 53:726-37. [PMID: 24560927 PMCID: PMC3988891 DOI: 10.1016/j.molcel.2014.01.013] [Citation(s) in RCA: 386] [Impact Index Per Article: 38.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2013] [Revised: 12/18/2013] [Accepted: 01/16/2014] [Indexed: 02/06/2023]
Abstract
Mitochondrial calcium accumulation was recently shown to depend on a complex composed of an inner-membrane channel (MCU and MCUb) and regulatory subunits (MICU1, MCUR1, and EMRE). A fundamental property of MCU is low activity at resting cytosolic Ca(2+) concentrations, preventing deleterious Ca(2+) cycling and organelle overload. Here we demonstrate that these properties are ensured by a regulatory heterodimer composed of two proteins with opposite effects, MICU1 and MICU2, which, both in purified lipid bilayers and in intact cells, stimulate and inhibit MCU activity, respectively. Both MICU1 and MICU2 are regulated by calcium through their EF-hand domains, thus accounting for the sigmoidal response of MCU to [Ca(2+)] in situ and allowing tight physiological control. At low [Ca(2+)], the dominant effect of MICU2 largely shuts down MCU activity; at higher [Ca(2+)], the stimulatory effect of MICU1 allows the prompt response of mitochondria to Ca(2+) signals generated in the cytoplasm.
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Affiliation(s)
- Maria Patron
- Department of Biomedical Sciences, University of Padova, Via Ugo Bassi 58, 35131 Padova, Italy; CNR Neuroscience Institute, Via Ugo Bassi 58, 35131 Padova, Italy
| | - Vanessa Checchetto
- Department of Biology, University of Padova, Via Ugo Bassi 58, 35131 Padova, Italy
| | - Anna Raffaello
- Department of Biomedical Sciences, University of Padova, Via Ugo Bassi 58, 35131 Padova, Italy; CNR Neuroscience Institute, Via Ugo Bassi 58, 35131 Padova, Italy
| | - Enrico Teardo
- Department of Biology, University of Padova, Via Ugo Bassi 58, 35131 Padova, Italy
| | - Denis Vecellio Reane
- Department of Biomedical Sciences, University of Padova, Via Ugo Bassi 58, 35131 Padova, Italy; CNR Neuroscience Institute, Via Ugo Bassi 58, 35131 Padova, Italy
| | - Maura Mantoan
- Department of Biomedical Sciences, University of Padova, Via Ugo Bassi 58, 35131 Padova, Italy; CNR Neuroscience Institute, Via Ugo Bassi 58, 35131 Padova, Italy
| | - Veronica Granatiero
- Department of Biomedical Sciences, University of Padova, Via Ugo Bassi 58, 35131 Padova, Italy; CNR Neuroscience Institute, Via Ugo Bassi 58, 35131 Padova, Italy
| | - Ildikò Szabò
- Department of Biology, University of Padova, Via Ugo Bassi 58, 35131 Padova, Italy
| | - Diego De Stefani
- Department of Biomedical Sciences, University of Padova, Via Ugo Bassi 58, 35131 Padova, Italy; CNR Neuroscience Institute, Via Ugo Bassi 58, 35131 Padova, Italy.
| | - Rosario Rizzuto
- Department of Biomedical Sciences, University of Padova, Via Ugo Bassi 58, 35131 Padova, Italy; CNR Neuroscience Institute, Via Ugo Bassi 58, 35131 Padova, Italy.
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Checchetto V, Teardo E, De Stefani D, Patron M, Raffaello A, Szabò I, Rizzuto R. Electrophysiological Characterization of the Activity and Regulation of the Mitochondrial Calcium Uniporter. Biophys J 2014. [DOI: 10.1016/j.bpj.2013.11.4184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
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Hill JM, De Stefani D, Jones AWE, Ruiz A, Rizzuto R, Szabadkai G. Measuring baseline Ca(2+) levels in subcellular compartments using genetically engineered fluorescent indicators. Methods Enzymol 2014; 543:47-72. [PMID: 24924127 DOI: 10.1016/b978-0-12-801329-8.00003-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Intracellular Ca(2+) signaling is involved in a series of physiological and pathological processes. In particular, an intimate crosstalk between bioenergetic metabolism and Ca(2+) homeostasis has been shown to determine cell fate in resting conditions as well as in response to stress. The endoplasmic reticulum and mitochondria represent key hubs of cellular metabolism and Ca(2+) signaling. However, it has been challenging to specifically detect highly localized Ca(2+) fluxes such as those bridging these two organelles. To circumvent this issue, various recombinant Ca(2+) indicators that can be targeted to specific subcellular compartments have been developed over the past two decades. While the use of these probes for measuring agonist-induced Ca(2+) signals in various organelles has been extensively described, the assessment of basal Ca(2+) concentrations within specific organelles is often disregarded, in spite of the fact that this parameter is vital for several metabolic functions, including the enzymatic activity of mitochondrial dehydrogenases of the Krebs cycle and protein folding in the endoplasmic reticulum. Here, we provide an overview on genetically engineered, organelle-targeted fluorescent Ca(2+) probes and outline their evolution. Moreover, we describe recently developed protocols to quantify baseline Ca(2+) concentrations in specific subcellular compartments. Among several applications, this method is suitable for assessing how changes in basal Ca(2+) levels affect the metabolic profile of cancer cells.
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Affiliation(s)
- Julia M Hill
- Department of Cell and Developmental Biology, Consortium for Mitochondrial Research, University College London, London, United Kingdom
| | - Diego De Stefani
- Department of Biomedical Sciences, CNR Neuroscience Institute, University of Padua, Padua, Italy
| | - Aleck W E Jones
- Department of Cell and Developmental Biology, Consortium for Mitochondrial Research, University College London, London, United Kingdom
| | - Asier Ruiz
- Department of Neurosciences, University of the Basque Country (UPV/EHU), Achúcarro Basque Center for Neuroscience-UPV/EHU, Leioa, Spain; Instituto de Salud Carlos III, Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas, (CIBERNED), Madrid, Spain
| | - Rosario Rizzuto
- Department of Biomedical Sciences, CNR Neuroscience Institute, University of Padua, Padua, Italy
| | - Gyorgy Szabadkai
- Department of Cell and Developmental Biology, Consortium for Mitochondrial Research, University College London, London, United Kingdom; Department of Biomedical Sciences, CNR Neuroscience Institute, University of Padua, Padua, Italy.
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39
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Raffaello A, De Stefani D, Sabbadin D, Teardo E, Merli G, Picard A, Checchetto V, Moro S, Szabò I, Rizzuto R. The mitochondrial calcium uniporter is a multimer that can include a dominant-negative pore-forming subunit. EMBO J 2013; 32:2362-76. [PMID: 23900286 DOI: 10.1038/emboj.2013.157] [Citation(s) in RCA: 372] [Impact Index Per Article: 33.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Accepted: 06/09/2013] [Indexed: 12/12/2022] Open
Abstract
Mitochondrial calcium uniporter (MCU) channel is responsible for Ruthenium Red-sensitive mitochondrial calcium uptake. Here, we demonstrate MCU oligomerization by immunoprecipitation and Förster resonance energy transfer (FRET) and characterize a novel protein (MCUb) with two predicted transmembrane domains, 50% sequence similarity and a different expression profile from MCU. Based on computational modelling, MCUb includes critical amino-acid substitutions in the pore region and indeed MCUb does not form a calcium-permeable channel in planar lipid bilayers. In HeLa cells, MCUb is inserted into the oligomer and exerts a dominant-negative effect, reducing the [Ca(2+)]mt increases evoked by agonist stimulation. Accordingly, in vitro co-expression of MCUb with MCU drastically reduces the probability of observing channel activity in planar lipid bilayer experiments. These data unveil the structural complexity of MCU and demonstrate a novel regulatory mechanism, based on the inclusion of dominant-negative subunits in a multimeric channel, that underlies the fine control of the physiologically and pathologically relevant process of mitochondrial calcium homeostasis.
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Affiliation(s)
- Anna Raffaello
- Department of Biomedical Sciences, University of Padua and CNR Neuroscience Institute, Padua, Italy
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40
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Patron M, Raffaello A, Granatiero V, Tosatto A, Merli G, De Stefani D, Wright L, Pallafacchina G, Terrin A, Mammucari C, Rizzuto R. The mitochondrial calcium uniporter (MCU): molecular identity and physiological roles. J Biol Chem 2013; 288:10750-8. [PMID: 23400777 DOI: 10.1074/jbc.r112.420752] [Citation(s) in RCA: 117] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The direct measurement of mitochondrial [Ca(2+)] with highly specific probes demonstrated that major swings in organellar [Ca(2+)] parallel the changes occurring in the cytosol and regulate processes as diverse as aerobic metabolism and cell death by necrosis and apoptosis. Despite great biological relevance, insight was limited by the complete lack of molecular understanding. The situation has changed, and new perspectives have emerged following the very recent identification of the mitochondrial Ca(2+) uniporter, the channel allowing rapid Ca(2+) accumulation across the inner mitochondrial membrane.
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Affiliation(s)
- Maria Patron
- Department of Biomedical Sciences, University of Padua and the Institute of Neuroscience, Consiglio Nazionale delle Ricerche, 35131 Padua, Italy
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41
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Maltecca F, De Stefani D, Cassina L, Consolato F, Wasilewski M, Scorrano L, Rizzuto R, Casari G. Respiratory dysfunction by AFG3L2 deficiency causes decreased mitochondrial calcium uptake via organellar network fragmentation. Hum Mol Genet 2012; 21:3858-70. [PMID: 22678058 PMCID: PMC3412383 DOI: 10.1093/hmg/dds214] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2012] [Accepted: 05/29/2012] [Indexed: 11/28/2022] Open
Abstract
The mitochondrial protein AFG3L2 forms homo-oligomeric and hetero-oligomeric complexes with paraplegin in the inner mitochondrial membrane, named m-AAA proteases. These complexes are in charge of quality control of misfolded proteins and participate in the regulation of OPA1 proteolytic cleavage, required for mitochondrial fusion. Mutations in AFG3L2 cause spinocerebellar ataxia type 28 and a complex neurodegenerative syndrome of childhood. In this study, we demonstrated that the loss of AFG3L2 in mouse embryonic fibroblasts (MEFs) reduces mitochondrial Ca(2+) uptake capacity. This defect is neither a consequence of global alteration in cellular Ca(2+) homeostasis nor of the reduced driving force for Ca(2+) internalization within mitochondria, since cytosolic Ca(2+) transients and mitochondrial membrane potential remain unaffected. Moreover, experiments in permeabilized cells revealed unaltered mitochondrial Ca(2+) uptake speed in Afg3l2(-/-) cells, indicating the presence of functional Ca(2+) uptake machinery. Our results show that the defective Ca(2+) handling in Afg3l2(-/-) cells is caused by fragmentation of the mitochondrial network, secondary to respiratory dysfunction and the consequent processing of OPA1. This leaves a number of mitochondria devoid of connections to the ER and thus without Ca(2+) elevations, hampering the proper Ca(2+) diffusion along the mitochondrial network. The recovery of mitochondrial fragmentation in Afg3l2(-/-) MEFs by overexpression of OPA1 rescues the impaired mitochondrial Ca(2+) buffering, but fails to restore respiration. By linking mitochondrial morphology and Ca(2+) homeostasis, these findings shed new light in the molecular mechanisms underlining neurodegeneration caused by AFG3L2 mutations.
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Affiliation(s)
- Francesca Maltecca
- San Raffaele Scientific Institute, Vita-Salute San Raffaele University and Center for Translational Genomics and Bioinformatics, Milan-I, Italy
| | - Diego De Stefani
- Department of Biomedical Sciences, University of Padova, Padova-I, Italy
| | - Laura Cassina
- San Raffaele Scientific Institute, Vita-Salute San Raffaele University and Center for Translational Genomics and Bioinformatics, Milan-I, Italy
- Department of Genetics, Biology and Biochemistry, University of Turin, Turin-I, Italy
| | - Francesco Consolato
- San Raffaele Scientific Institute, Vita-Salute San Raffaele University and Center for Translational Genomics and Bioinformatics, Milan-I, Italy
- PhD school of Neurobiology, University of Insubria, Varese-I, Italy
| | - Michal Wasilewski
- Department of Cell Physiology and Metabolism, University of Geneva Medical School, Genève-CH, Switzerland and Dulbecco-Telethon Institute, Padova-I, Italy
| | - Luca Scorrano
- Department of Cell Physiology and Metabolism, University of Geneva Medical School, Genève-CH, Switzerland and Dulbecco-Telethon Institute, Padova-I, Italy
| | - Rosario Rizzuto
- Department of Biomedical Sciences, University of Padova, Padova-I, Italy
| | - Giorgio Casari
- San Raffaele Scientific Institute, Vita-Salute San Raffaele University and Center for Translational Genomics and Bioinformatics, Milan-I, Italy
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Abstract
Mitochondrial Ca(2+) uptake plays a fundamental role in the regulation of energy production and cell survival. Under physiological conditions, mitochondrial Ca(2+) uptake occurs by a uniport mechanism driven electrophoretically by the membrane potential created by the respiratory chain. The activity and the biochemical properties of the mitochondrial calcium uniporter (MCU) were extensively characterized for decades but the molecular identity of the channel has remained elusive. Here, we review the recent discovery of the mitochondria Ca(2+) uniporter that represents a groundbreaking result for the molecular understanding of mitochondrial Ca(2+) homeostasis and will provide insight into the role of mitochondrial Ca(2+) deregulation in the pathogenesis of human disorders.
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Affiliation(s)
- Anna Raffaello
- Department of Biomedical Sciences, University of Padua and CNR Neuroscience Institute, Via G. Colombo 3, 35131 Padua, Italy
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43
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De Stefani D, Raffaello A, Teardo E, Szabò I, Rizzuto R. A forty-kilodalton protein of the inner membrane is the mitochondrial calcium uniporter. Nature 2011; 476:336-40. [PMID: 21685888 PMCID: PMC4141877 DOI: 10.1038/nature10230] [Citation(s) in RCA: 1409] [Impact Index Per Article: 108.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2010] [Accepted: 05/27/2011] [Indexed: 02/06/2023]
Abstract
Mitochondrial Ca(2+) homeostasis has a key role in the regulation of aerobic metabolism and cell survival, but the molecular identity of the Ca(2+) channel, the mitochondrial calcium uniporter, is still unknown. Here we have identified in silico a protein (named MCU) that shares tissue distribution with MICU1 (also known as CBARA1), a recently characterized uniporter regulator, is present in organisms in which mitochondrial Ca(2+) uptake was demonstrated and whose sequence includes two transmembrane domains. Short interfering RNA (siRNA) silencing of MCU in HeLa cells markedly reduced mitochondrial Ca(2+) uptake. MCU overexpression doubled the matrix Ca(2+) concentration increase evoked by inositol 1,4,5-trisphosphate-generating agonists, thus significantly buffering the cytosolic elevation. The purified MCU protein showed channel activity in planar lipid bilayers, with electrophysiological properties and inhibitor sensitivity of the uniporter. A mutant MCU, in which two negatively charged residues of the putative pore-forming region were replaced, had no channel activity and reduced agonist-dependent matrix Ca(2+) concentration transients when overexpressed in HeLa cells. Overall, these data demonstrate that the 40-kDa protein identified is the channel responsible for ruthenium-red-sensitive mitochondrial Ca(2+) uptake, thus providing a molecular basis for this process of utmost physiological and pathological relevance.
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Affiliation(s)
- Diego De Stefani
- Department of Biomedical Science, University of Padua, 35121 Padua, Italy
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44
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Rizzuto R, Marchi S, Bonora M, Aguiari P, Bononi A, De Stefani D, Giorgi C, Leo S, Rimessi A, Siviero R, Zecchini E, Pinton P. Ca(2+) transfer from the ER to mitochondria: when, how and why. Biochim Biophys Acta 2009; 1787:1342-51. [PMID: 19341702 PMCID: PMC2730423 DOI: 10.1016/j.bbabio.2009.03.015] [Citation(s) in RCA: 340] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2009] [Revised: 03/21/2009] [Accepted: 03/24/2009] [Indexed: 10/25/2022]
Abstract
The heterogenous subcellular distribution of a wide array of channels, pumps and exchangers allows extracellular stimuli to induce increases in cytoplasmic Ca(2+) concentration ([Ca(2+)]c) with highly defined spatial and temporal patterns, that in turn induce specific cellular responses (e.g. contraction, secretion, proliferation or cell death). In this extreme complexity, the role of mitochondria was considered marginal, till the direct measurement with targeted indicators allowed to appreciate that rapid and large increases of the [Ca(2+)] in the mitochondrial matrix ([Ca(2+)]m) invariably follow the cytosolic rises. Given the low affinity of the mitochondrial Ca(2+) transporters, the close proximity to the endoplasmic reticulum (ER) Ca(2+)-releasing channels was shown to be responsible for the prompt responsiveness of mitochondria. In this review, we will summarize the current knowledge of: i) the mitochondrial and ER Ca(2+) channels mediating the ion transfer, ii) the structural and molecular foundations of the signaling contacts between the two organelles, iii) the functional consequences of the [Ca(2+)]m increases, and iv) the effects of oncogene-mediated signals on mitochondrial Ca(2+) homeostasis. Despite the rapid progress carried out in the latest years, a deeper molecular understanding is still needed to unlock the secrets of Ca(2+) signaling machinery.
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Affiliation(s)
- Rosario Rizzuto
- Dept. Biomedical Sciences, University of Padua, Via Colombo 3, Padua 35121, Italy.
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45
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Giorgi C, De Stefani D, Bononi A, Rizzuto R, Pinton P. Structural and functional link between the mitochondrial network and the endoplasmic reticulum. Int J Biochem Cell Biol 2009; 41:1817-27. [PMID: 19389485 DOI: 10.1016/j.biocel.2009.04.010] [Citation(s) in RCA: 297] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2008] [Revised: 04/09/2009] [Accepted: 04/14/2009] [Indexed: 01/10/2023]
Abstract
Mitochondrial and endoplasmic reticulum (ER) networks are fundamental for the maintenance of cellular homeostasis and for determination of cell fate under stress conditions. Recent structural and functional studies revealed the interaction of these networks. These zones of close contact between ER and mitochondria called MAM (mitochondria associated membranes) support communication between the two organelles including bioenergetics and cell survival. The existence of macromolecular complexes in these contact sites has also been revealed. In this contribution, we will review: (i) the ER and mitochondria structure and their dynamics, (ii) the basic principles of ER mitochondrial Ca(2+) transport, (iii) the physiological/pathological role of this cross-talk.
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Affiliation(s)
- Carlotta Giorgi
- Department of Experimental and Diagnostic Medicine, Section of General Pathology, Interdisciplinary Center for the Study of Inflammation (ICSI) and Emilia Romagna Laboratory BioPharmaNet, University of Ferrara, Via Borsari 46, 44100 Ferrara, Italy
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46
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Vettor R, Granzotto M, De Stefani D, Trevellin E, Rossato M, Farina MG, Milan G, Pilon C, Nigro A, Federspil G, Vigneri R, Vitiello L, Rizzuto R, Baratta R, Frittitta L. Loss-of-function mutation of the GPR40 gene associates with abnormal stimulated insulin secretion by acting on intracellular calcium mobilization. J Clin Endocrinol Metab 2008; 93:3541-50. [PMID: 18583466 DOI: 10.1210/jc.2007-2680] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BACKGROUND Free fatty acids (FFAs) acutely stimulate but chronically impair glucose-stimulated insulin secretion from beta-cells. The G protein-coupled transmembrane receptor 40 (GPR40) mediates both acute and chronic effects of FFAs on insulin secretion and plays a role in glucose homeostasis. Limited information is available on the effect of GPR40 genetic abnormalities on insulin secretion and metabolic regulation in human subjects. STUDY DESIGN AND RESULTS For in vivo studies, we screened 734 subjects for the coding region of GPR40 and identified a new single-nucleotide mutation (Gly180Ser). The mean allele frequency was 0.75%, which progressively increased (P < 0.05) from nonobese subjects (0.42%) to moderately obese (body mass index = 30-39.9 kg/m2, 1.07%) and severely obese patients (body mass index > or = 40 kg/m2, 2.60%). The relationship between the GPR40 mutation, insulin secretion, and metabolic alterations was studied in 11 Gly/Ser mutation carriers. In these subjects, insulin secretion (insulinogenic index derived from oral glucose tolerance test) was significantly lower than in 692 Gly/Gly carriers (86.0 +/- 48.2 vs. 183.7 +/- 134.4, P < 0.005). Moreover, a case-control study indicated that plasma insulin and C-peptide responses to a lipid load were significantly (P < 0.05) lower in six Gly/Ser than in 12 Gly/Gly carriers. In vitro experiments in HeLa cells cotransfected with aequorin and the mutated Gly/Ser GPR40 indicated that intracellular Ca2+ concentration increase after oleic acid was significantly lower than in Gly/Gly GPR40-transfected cells. This fact was confirmed using fura-2 acetoxymethyl ester. CONCLUSIONS This newly identified GPR40 variant results in a loss of function that prevents the beta-cell ability to adequately sense lipids as an insulin secretory stimulus because of impaired intracellular Ca2+ concentration increase.
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Affiliation(s)
- Roberto Vettor
- Endocrine-Metabolic Laboratory, Internal Medicine, Department of Medical and Surgical Sciences, University of Padova, via Ospedale, 105, I-35128 Padova, Italy.
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47
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Szabadkai G, Bianchi K, Várnai P, De Stefani D, Wieckowski MR, Cavagna D, Nagy AI, Balla T, Rizzuto R. Chaperone-mediated coupling of endoplasmic reticulum and mitochondrial Ca2+ channels. ACTA ACUST UNITED AC 2007; 175:901-11. [PMID: 17178908 PMCID: PMC2064700 DOI: 10.1083/jcb.200608073] [Citation(s) in RCA: 1012] [Impact Index Per Article: 59.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The voltage-dependent anion channel (VDAC) of the outer mitochondrial membrane mediates metabolic flow, Ca(2+), and cell death signaling between the endoplasmic reticulum (ER) and mitochondrial networks. We demonstrate that VDAC1 is physically linked to the endoplasmic reticulum Ca(2+)-release channel inositol 1,4,5-trisphosphate receptor (IP(3)R) through the molecular chaperone glucose-regulated protein 75 (grp75). Functional interaction between the channels was shown by the recombinant expression of the ligand-binding domain of the IP(3)R on the ER or mitochondrial surface, which directly enhanced Ca(2+) accumulation in mitochondria. Knockdown of grp75 abolished the stimulatory effect, highlighting chaperone-mediated conformational coupling between the IP(3)R and the mitochondrial Ca(2+) uptake machinery. Because organelle Ca(2+) homeostasis influences fundamentally cellular functions and death signaling, the central location of grp75 may represent an important control point of cell fate and pathogenesis.
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Affiliation(s)
- György Szabadkai
- Department of Experimental and Diagnostic Medicine, Section of General Pathology, Interdisciplinary Center for the Study of Inflammation, Emilia Romagna Laboratory for Genomics and Biotechnology, University of Ferrara, Ferrara 44100, Italy
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Romagnoli A, Aguiari P, De Stefani D, Leo S, Marchi S, Rimessi A, Zecchini E, Pinton P, Rizzuto R. Endoplasmic reticulum/mitochondria calcium cross-talk. Novartis Found Symp 2007; 287:122-139. [PMID: 18074635] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
The interaction of mitochondria with the endoplasmic reticulum (ER) Ca2+ store plays a key role in allowing these organelles to rapidly and effectively respond to cellular Ca2+ signals. In this contribution, we will briefly discuss: (i) old and new concepts of mitochondrial Ca2+ homeostasis; (ii) the relationship between mitochondrial 3D structure and Ca2+ homeostasis; (iii) the modulation by cytoplasmic signalling pathways; and (iv) new data suggesting that mitochondria and ER Ca2+ channels are assembled in a macromolecular complex in which the inositol-1,4,5-trisphosphate receptor directly stimulates the mitochondrial Ca2+ uptake machinery.
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Affiliation(s)
- Anna Romagnoli
- ER-GenTech and Interdisciplinary Center for the Study of Inflammation, Department of Experimental and Diagnostic Medicine, University of Ferrara, Italy
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