1
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Bulthuis EP, Adjobo-Hermans MJW, de Potter B, Hoogstraten S, Wezendonk LHT, Tutakhel OAZ, Wintjes LT, van den Heuvel B, Willems PHGM, Kamsteeg EJ, Gozalbo MER, Sallevelt SCEH, Koudijs SM, Nicolai J, de Bie CI, Hoogendijk JE, Koopman WJH, Rodenburg RJ. SMDT1 variants impair EMRE-mediated mitochondrial calcium uptake in patients with muscle involvement. Biochim Biophys Acta Mol Basis Dis 2023; 1869:166808. [PMID: 37454773 DOI: 10.1016/j.bbadis.2023.166808] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Revised: 06/26/2023] [Accepted: 07/10/2023] [Indexed: 07/18/2023]
Abstract
Ionic calcium (Ca2+) is a key messenger in signal transduction and its mitochondrial uptake plays an important role in cell physiology. This uptake is mediated by the mitochondrial Ca2+ uniporter (MCU), which is regulated by EMRE (essential MCU regulator) encoded by the SMDT1 (single-pass membrane protein with aspartate rich tail 1) gene. This work presents the genetic, clinical and cellular characterization of two patients harbouring SMDT1 variants and presenting with muscle problems. Analysis of patient fibroblasts and complementation experiments demonstrated that these variants lead to absence of EMRE protein, induce MCU subcomplex formation and impair mitochondrial Ca2+ uptake. However, the activity of oxidative phosphorylation enzymes, mitochondrial morphology and membrane potential, as well as routine/ATP-linked respiration were not affected. We hypothesize that the muscle-related symptoms in the SMDT1 patients result from aberrant mitochondrial Ca2+ uptake.
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Affiliation(s)
- Elianne P Bulthuis
- Department of Biochemistry (286), Radboud Institute for Molecular Life Sciences, Radboud University Medical Centre, 6525 GA Nijmegen, the Netherlands
| | - Merel J W Adjobo-Hermans
- Department of Biochemistry (286), Radboud Institute for Molecular Life Sciences, Radboud University Medical Centre, 6525 GA Nijmegen, the Netherlands
| | - Bastiaan de Potter
- Department of Biochemistry (286), Radboud Institute for Molecular Life Sciences, Radboud University Medical Centre, 6525 GA Nijmegen, the Netherlands
| | - Saskia Hoogstraten
- Department of Biochemistry (286), Radboud Institute for Molecular Life Sciences, Radboud University Medical Centre, 6525 GA Nijmegen, the Netherlands; Human and Animal Physiology, Wageningen University & Research, 6700 AH Wageningen, the Netherlands
| | - Lisanne H T Wezendonk
- Department of Biochemistry (286), Radboud Institute for Molecular Life Sciences, Radboud University Medical Centre, 6525 GA Nijmegen, the Netherlands
| | - Omar A Z Tutakhel
- Translational Metabolic Laboratory, Department of Laboratory Medicine, Radboud University Medical Centre, 6525 GA Nijmegen, the Netherlands
| | - Liesbeth T Wintjes
- Translational Metabolic Laboratory, Department of Laboratory Medicine, Radboud University Medical Centre, 6525 GA Nijmegen, the Netherlands
| | - Bert van den Heuvel
- Translational Metabolic Laboratory, Department of Laboratory Medicine, Radboud University Medical Centre, 6525 GA Nijmegen, the Netherlands
| | - Peter H G M Willems
- Department of Biochemistry (286), Radboud Institute for Molecular Life Sciences, Radboud University Medical Centre, 6525 GA Nijmegen, the Netherlands
| | - Erik-Jan Kamsteeg
- Department of Human Genetics, Radboud University Medical Centre, 6525 GA Nijmegen, the Netherlands
| | - M Estela Rubio Gozalbo
- Department of Pediatrics, Maastricht University Medical Centre, 6229 HX Maastricht, the Netherlands; Department of Clinical Genetics, Maastricht University Medical Centre, 6229 HX Maastricht, the Netherlands
| | - Suzanne C E H Sallevelt
- Department of Clinical Genetics, Maastricht University Medical Centre, 6229 HX Maastricht, the Netherlands
| | - Suzanne M Koudijs
- Department of Neurology, Maastricht University Medical Centre, 6229 HX Maastricht, the Netherlands
| | - Joost Nicolai
- Department of Neurology, Maastricht University Medical Centre, 6229 HX Maastricht, the Netherlands
| | - Charlotte I de Bie
- Department of Genetics, University Medical Centre Utrecht, 3508 AB Utrecht, the Netherlands
| | - Jessica E Hoogendijk
- Rudolf Magnus Institute of Neuroscience, University Medical Centre Utrecht, 3584 CG Utrecht, the Netherlands
| | - Werner J H Koopman
- Human and Animal Physiology, Wageningen University & Research, 6700 AH Wageningen, the Netherlands; Department of Pediatrics, Amalia Children's Hospital, Radboud Center for Mitochondrial Medicine, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, 6500 HB Nijmegen, the Netherlands.
| | - Richard J Rodenburg
- Department of Pediatrics, Amalia Children's Hospital, Radboud Center for Mitochondrial Medicine, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, 6500 HB Nijmegen, the Netherlands.
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2
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Protasoni M, Serrano M. Targeting Mitochondria to Control Ageing and Senescence. Pharmaceutics 2023; 15:pharmaceutics15020352. [PMID: 36839673 PMCID: PMC9960816 DOI: 10.3390/pharmaceutics15020352] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 12/22/2022] [Accepted: 12/26/2022] [Indexed: 01/24/2023] Open
Abstract
Ageing is accompanied by a progressive impairment of cellular function and a systemic deterioration of tissues and organs, resulting in increased vulnerability to multiple diseases. Here, we review the interplay between two hallmarks of ageing, namely, mitochondrial dysfunction and cellular senescence. The targeting of specific mitochondrial features in senescent cells has the potential of delaying or even reverting the ageing process. A deeper and more comprehensive understanding of mitochondrial biology in senescent cells is necessary to effectively face this challenge. Here, we discuss the main alterations in mitochondrial functions and structure in both ageing and cellular senescence, highlighting the differences and similarities between the two processes. Moreover, we describe the treatments available to target these pathways and speculate on possible future directions of anti-ageing and anti-senescence therapies targeting mitochondria.
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Affiliation(s)
- Margherita Protasoni
- Institute for Research in Biomedicine (IRB Barcelona), Barcelona Institute of Science and Technology (BIST), 08028 Barcelona, Spain
| | - Manuel Serrano
- Institute for Research in Biomedicine (IRB Barcelona), Barcelona Institute of Science and Technology (BIST), 08028 Barcelona, Spain
- Catalan Institution for Research and Advanced Studies (ICREA), 08010 Barcelona, Spain
- Cambridge Institute of Science, Altos Labs, Granta Park, Cambridge CB21 6GP, UK
- Correspondence:
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3
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Onikanni SA, Lawal B, Bakare OS, Ajiboye BO, Ojo OA, Farasani A, Kabrah SM, Batiha GES, Conte-Junior CA. Cancer of the Liver and its Relationship with Diabetes mellitus. Technol Cancer Res Treat 2022; 21:15330338221119743. [PMID: 36533882 PMCID: PMC9772979 DOI: 10.1177/15330338221119743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
A high increase witnessed in type II diabetes mellitus (T2DM) globally has increasingly posed a serious threat to global increases in liver cancer with the association between diabetes mellitus type II and the survival rate in liver cancer patients showing unstable findings. An increase in the development and progression of chronic liver disease from diabetes mellitus patients may be connected to cancer of the liver with several links such as Hepatitis B and C virus and heavy consumption of alcohol. The link between T2DM patients and liver cancer is centered on non-alcoholic fatty liver disease (NAFLD) which could be a serious threat globally if not clinically addressed. Several reports identified metformin treatment as linked to a lower risk of liver cancer prognosis while insulin treatment or sulphonylureas posed a serious threat. Mechanistically, the biological linkage between diabetes type II mellitus and liver cancer are still complex to understand with only the existence of a relationship between NAFLD and high level of energy intake and diabetes mellitus induces hepatic damage, increased liver weight thereby causes multiple pro-inflammatory cytokines that lead to the development of liver cancer. Therefore, this review gives an account of the pathophysiological importance of liver cancer position with T2DM, with the role of NAFLD as an important factor that bridges them.
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Affiliation(s)
- Sunday Amos Onikanni
- Department of Chemical Sciences, Biochemistry Unit, Afe Babalola University, Ado-Ekiti, Ekiti State, Nigeria,College of Medicine, Graduate Institute of Biomedical Sciences, China Medical University, Taichung, Taiwan,Sunday Amos Onikanni, College of Medicine, Graduate Institute of Biomedical Sciences, China Medical University, Taichung, Taiwan.
| | - Bashir Lawal
- PhD Program for Cancer Molecular Biology and Drug Discovery, College of Medical Science and Technology, Taipei Medical University and Academia Sinica, Taipei,Graduate Institute for Cancer Biology & Drug Discovery, College of Medical Science and Technology, Taipei Medical University, Taipei
| | | | - Basiru Olaitan Ajiboye
- Phytomedicine and Molecular Toxicology Research Laboratory, Department of Biochemistry, Federal University Oye-Ekiti, Ekiti State, Nigeria
| | - Oluwafemi Adeleke Ojo
- Phytomedicine, Molecular Toxicology, and Computational Biochemistry Research Laboratory (PMTCB-RL), Department of Biochemistry, Bowen University, Iwo, 232101, Nigeria
| | - Abdullah Farasani
- Biomedical Research Unit, Medical Research Center, College of Applied Medical Sciences, Jazan University, Jazan, Saudi Arabia,Department of Medical Laboratory Technology, College of Applied Medical Sciences, Jazan University, Jazan, Saudi Arabia
| | - Saeed M Kabrah
- Department of Laboratory Medicine Faculty of Applied medical sciences, Umm Al-Qura University, Kingdom of Saudi Arabia
| | - Gaber El-Saber Batiha
- Department of Pharmacology and Therapeutics, Faculty of Veterinary Medicine, Damanhour University, Damanhour, AlBeheira, Egypt
| | - Carlos Adam Conte-Junior
- Analytical and Molecular Laboratorial Center (CLAn), Institute of Chemistry (IQ), Federal University of Rio de Janeiro (UFRJ), Cidade Universitária, Rio de Janeiro, RJ, 21941-909, Brazil
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4
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Onikanni SA, Lawal B, Oyinloye BE, Ajiboye BO, Ulziijargal S, Wang CH, Emran TB, Simal-Gandara J. Mitochondrial defects in pancreatic beta-cell dysfunction and neurodegenerative diseases: Pathogenesis and therapeutic applications. Life Sci 2022; 312:121247. [PMID: 36450327 DOI: 10.1016/j.lfs.2022.121247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Revised: 11/12/2022] [Accepted: 11/24/2022] [Indexed: 11/29/2022]
Abstract
Mitochondria malfunction is linked to the development of β-cell failure and a variety of neurodegenerative disorders. Pancreatic β-cells are normally configured to detect glucose and other food secretagogues in order to adjust insulin exocytosis and maintain glucose homeostasis. As a result of the increased glucose level, mitochondria metabolites and nucleotides are produced, which operate in concert with cytosolic Ca2+ to stimulate insulin secretion. Furthermore, mitochondria are the primary generators of adenosine triphosphate (ATP), reactive oxygen species (ROS), and apoptosis regulation. Mitochondria are concentrated in synapses, and any substantial changes in synaptic mitochondria location, shape, quantity, or function might cause oxidative stress, resulting in faulty synaptic transmission, a symptom of various degenerative disorders at an early stage. However, a greater understanding of the role of mitochondria in the etiology of β-cell dysfunction and neurodegenerative disorder should pave the way for a more effective approach to addressing these health issues. This review looks at the widespread occurrence of mitochondria depletion in humans, and its significance to mitochondria biogenesis in signaling and mitophagy. Proper understanding of the processes might be extremely beneficial in ameliorating the rising worries about mitochondria biogenesis and triggering mitophagy to remove depleted mitochondria, therefore reducing disease pathogenesis.
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Affiliation(s)
- Sunday Amos Onikanni
- Graduate Institute of Biomedical Science, College of Medicine, China Medical University, Taichung, Taiwan; Department of Chemical Sciences, Biochemistry Unit, Afe Babalola University, Ado-Ekiti, Ekiti State, Nigeria.
| | - Bashir Lawal
- PhD Program for Cancer Molecular Biology and Drug Discovery, College of Medical Science and Technology, Taipei Medical University and Academia Sinica, Taipei 11031, Taiwan; Graduate Institute for Cancer Biology & Drug Discovery, College of Medical Science and Technology, Taipei Medical University, Taipei 11031, Taiwan
| | - Babatunji Emmanuel Oyinloye
- Department of Chemical Sciences, Biochemistry Unit, Afe Babalola University, Ado-Ekiti, Ekiti State, Nigeria; Biotechnology and Structural Biology (BSB) Group, Department of Biochemistry and Microbiology, University of Zululand, KwaDlangezwa 3886, South Africa; Institute of Drug Research and Development, SE Bogoro Center, Afe Babalola University, PMB 5454, Ado-Ekiti 360001, Nigeria
| | - Basiru Olaitan Ajiboye
- Institute of Drug Research and Development, SE Bogoro Center, Afe Babalola University, PMB 5454, Ado-Ekiti 360001, Nigeria; Phytomedicine and Molecular Toxicology Research Laboratory, Department of Biochemistry, Federal University of Technology, Oye-Ekiti, Ekiti State, Nigeria
| | - Sukhbat Ulziijargal
- Graduate Institute of Biomedical Science, College of Medicine, China Medical University, Taichung, Taiwan
| | - Chih-Hao Wang
- Graduate Institute of Biomedical Science, College of Medicine, China Medical University, Taichung, Taiwan
| | - Talha Bin Emran
- Department of Pharmacy, BGC Trust University Bangladesh, Chittagong 4381, Bangladesh; Department of Pharmacy, Faculty of Allied Health Sciences, Daffodil International University, Dhaka 1207, Bangladesh.
| | - Jesus Simal-Gandara
- Universidade de Vigo, Nutrition and Bromatology Group, Analytical Chemistry and Food Science Department, Faculty of Science, E32004 Ourense, Spain.
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5
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Georgiadou E, Muralidharan C, Martinez M, Chabosseau P, Akalestou E, Tomas A, Wern FYS, Stylianides T, Wretlind A, Legido-Quigley C, Jones B, Lopez-Noriega L, Xu Y, Gu G, Alsabeeh N, Cruciani-Guglielmacci C, Magnan C, Ibberson M, Leclerc I, Ali Y, Soleimanpour SA, Linnemann AK, Rodriguez TA, Rutter GA. Mitofusins Mfn1 and Mfn2 Are Required to Preserve Glucose- but Not Incretin-Stimulated β-Cell Connectivity and Insulin Secretion. Diabetes 2022; 71:1472-1489. [PMID: 35472764 PMCID: PMC9233298 DOI: 10.2337/db21-0800] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Accepted: 04/04/2022] [Indexed: 01/21/2023]
Abstract
Mitochondrial glucose metabolism is essential for stimulated insulin release from pancreatic β-cells. Whether mitofusin gene expression, and hence, mitochondrial network integrity, is important for glucose or incretin signaling has not previously been explored. Here, we generated mice with β-cell-selective, adult-restricted deletion knock-out (dKO) of the mitofusin genes Mfn1 and Mfn2 (βMfn1/2 dKO). βMfn1/2-dKO mice displayed elevated fed and fasted glycemia and a more than fivefold decrease in plasma insulin. Mitochondrial length, glucose-induced polarization, ATP synthesis, and cytosolic and mitochondrial Ca2+ increases were all reduced in dKO islets. In contrast, oral glucose tolerance was more modestly affected in βMfn1/2-dKO mice, and glucagon-like peptide 1 or glucose-dependent insulinotropic peptide receptor agonists largely corrected defective glucose-stimulated insulin secretion through enhanced EPAC-dependent signaling. Correspondingly, cAMP increases in the cytosol, as measured with an Epac-camps-based sensor, were exaggerated in dKO mice. Mitochondrial fusion and fission cycles are thus essential in the β-cell to maintain normal glucose, but not incretin, sensing. These findings broaden our understanding of the roles of mitofusins in β-cells, the potential contributions of altered mitochondrial dynamics to diabetes development, and the impact of incretins on this process.
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Affiliation(s)
- Eleni Georgiadou
- Section of Cell Biology and Functional Genomics, Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Imperial College London, London, U.K
| | - Charanya Muralidharan
- Center for Diabetes and Metabolic Diseases, Indiana University School of Medicine, Indianapolis, IN
| | - Michelle Martinez
- Center for Diabetes and Metabolic Diseases, Indiana University School of Medicine, Indianapolis, IN
| | - Pauline Chabosseau
- Section of Cell Biology and Functional Genomics, Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Imperial College London, London, U.K
| | - Elina Akalestou
- Section of Cell Biology and Functional Genomics, Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Imperial College London, London, U.K
| | - Alejandra Tomas
- Section of Cell Biology and Functional Genomics, Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Imperial College London, London, U.K
| | - Fiona Yong Su Wern
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore
| | - Theodoros Stylianides
- Centre of Innovative and Collaborative Construction Engineering, Loughborough University, Leicestershire, U.K
| | - Asger Wretlind
- Systems Medicin, Steno Diabetes Center Copenhagen, Copenhagen, Denmark
| | - Cristina Legido-Quigley
- Systems Medicin, Steno Diabetes Center Copenhagen, Copenhagen, Denmark
- Institute of Pharmaceutical Science, Kings College London, London, U.K
| | - Ben Jones
- Section of Endocrinology and Investigative Medicine, Imperial College, London, U.K
| | - Livia Lopez-Noriega
- Section of Cell Biology and Functional Genomics, Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Imperial College London, London, U.K
| | - Yanwen Xu
- Department of Cell and Developmental Biology, Program of Developmental Biology, and Vanderbilt Center for Stem Cell Biology, Vanderbilt University, School of Medicine, Nashville, TN
| | - Guoqiang Gu
- Department of Cell and Developmental Biology, Program of Developmental Biology, and Vanderbilt Center for Stem Cell Biology, Vanderbilt University, School of Medicine, Nashville, TN
| | - Nour Alsabeeh
- Department of Physiology, Health Sciences Center, Kuwait University, Kuwait City, Kuwait
| | | | - Christophe Magnan
- Regulation of Glycemia by Central Nervous System, Université de Paris, BFA, UMR 8251, CNRS, Paris, France
| | - Mark Ibberson
- Vital-IT Group, SIB Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - Isabelle Leclerc
- Section of Cell Biology and Functional Genomics, Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Imperial College London, London, U.K
| | - Yusuf Ali
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore
| | - Scott A. Soleimanpour
- Division of Metabolism, Endocrinology & Diabetes and Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI
- Veterans Affairs Ann Arbor Healthcare System, Ann Arbor, MI
| | - Amelia K. Linnemann
- Center for Diabetes and Metabolic Diseases, Indiana University School of Medicine, Indianapolis, IN
| | - Tristan A. Rodriguez
- Imperial Centre for Translational and Experimental Medicine, National Heart and Lung Institute, Imperial College London, London, U.K
| | - Guy A. Rutter
- Section of Cell Biology and Functional Genomics, Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Imperial College London, London, U.K
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore
- Centre of Research of Centre Hospitalier de l'Université de Montréal (CHUM), University of Montreal, Montreal, Quebec, Canada
- Corresponding author: Guy A. Rutter, or
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6
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Khodzhaeva V, Schreiber Y, Geisslinger G, Brandes RP, Brüne B, Namgaladze D. Mitofusin 2 Deficiency Causes Pro-Inflammatory Effects in Human Primary Macrophages. Front Immunol 2021; 12:723683. [PMID: 34456930 PMCID: PMC8397414 DOI: 10.3389/fimmu.2021.723683] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Accepted: 07/28/2021] [Indexed: 01/23/2023] Open
Abstract
Mitofusin 2 (MFN2) is a mitochondrial outer membrane GTPase, which modulates mitochondrial fusion and affects the interaction between endoplasmic reticulum and mitochondria. Here, we explored how MFN2 influences mitochondrial functions and inflammatory responses towards zymosan in primary human macrophages. A knockdown of MFN2 by small interfering RNA decreased mitochondrial respiration without attenuating mitochondrial membrane potential and reduced interactions between endoplasmic reticulum and mitochondria. A MFN2 deficiency potentiated zymosan-elicited inflammatory responses of human primary macrophages, such as expression and secretion of pro-inflammatory cytokines interleukin-1β, -6, -8 and tumor necrosis factor α, as well as induction of cyclooxygenase 2 and prostaglandin E2 synthesis. MFN2 silencing also increased zymosan-induced nuclear factor kappa-light-chain-enhancer of activated B cells and mitogen-activated protein kinases inflammatory signal transduction, without affecting mitochondrial reactive oxygen species production. Mechanistic studies revealed that MFN2 deficiency enhanced the toll-like receptor 2-dependent branch of zymosan-triggered responses upstream of inhibitor of κB kinase. This was associated with elevated, cytosolic expression of interleukin-1 receptor-associated kinase 4 in MFN2-deficient cells. Our data suggest pro-inflammatory effects of MFN2 deficiency in human macrophages.
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Affiliation(s)
- Vera Khodzhaeva
- Institute of Biochemistry I, Faculty of Medicine, Goethe-University Frankfurt, Frankfurt, Germany
| | - Yannick Schreiber
- Fraunhofer Institute for Translational Medicine and Pharmacology ITMP, Frankfurt, Germany
| | - Gerd Geisslinger
- Fraunhofer Institute for Translational Medicine and Pharmacology ITMP, Frankfurt, Germany.,Institute of Clinical Pharmacology, Pharmazentrum Frankfurt/ZAFES, University Hospital, Goethe-University Frankfurt, Frankfurt, Germany
| | - Ralf P Brandes
- Institute for Cardiovascular Physiology, Goethe-University Frankfurt, Frankfurt, Germany
| | - Bernhard Brüne
- Institute of Biochemistry I, Faculty of Medicine, Goethe-University Frankfurt, Frankfurt, Germany.,Fraunhofer Institute for Translational Medicine and Pharmacology ITMP, Frankfurt, Germany.,German Cancer Consortium (DKTK), Partner Site Frankfurt, Frankfurt, Germany.,Frankfurt Cancer Institute, Goethe-University Frankfurt, Frankfurt, Germany
| | - Dmitry Namgaladze
- Institute of Biochemistry I, Faculty of Medicine, Goethe-University Frankfurt, Frankfurt, Germany
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7
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Yasukawa K, Koshiba T. Mitochondrial reactive zones in antiviral innate immunity. Biochim Biophys Acta Gen Subj 2021; 1865:129839. [PMID: 33412226 DOI: 10.1016/j.bbagen.2020.129839] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 12/20/2020] [Accepted: 12/24/2020] [Indexed: 12/19/2022]
Abstract
Mitochondria are multi-functioning organelles that participate in a wide range of biologic processes from energy metabolism to cellular suicide. Mitochondria are also involved in the cellular innate immune response against microorganisms or environmental irritants, particularly in mammals. Mitochondrial-mediated innate immunity is achieved by the activation of two discrete signaling pathways, the NLR family pyrin domain-containing 3 inflammasomes and the retinoic acid-inducible gene I-like receptor pathway. In both pathways, a mitochondrial outer membrane adaptor protein, called mitochondrial antiviral signaling MAVS, and mitochondria-derived components play a key role in signal transduction. In this review, we discuss current insights regarding the fundamental phenomena of mitochondrial-related innate immune responses, and review the specific roles of various mitochondrial subcompartments in fine-tuning innate immune signaling events. We propose that specific targeting of mitochondrial functions is a potential therapeutic approach for the management of infectious diseases and autoinflammatory disorders with an excessive immune response.
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Affiliation(s)
- Kai Yasukawa
- Department of Biology, Faculty of Science, Kyushu University, Fukuoka 819-0395, Japan
| | - Takumi Koshiba
- Department of Chemistry, Faculty of Science, Fukuoka University, Fukuoka 814-0180, Japan.
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8
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Carpio MA, Means RE, Brill AL, Sainz A, Ehrlich BE, Katz SG. BOK controls apoptosis by Ca 2+ transfer through ER-mitochondrial contact sites. Cell Rep 2021; 34:108827. [PMID: 33691099 PMCID: PMC7995216 DOI: 10.1016/j.celrep.2021.108827] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Revised: 11/20/2020] [Accepted: 02/16/2021] [Indexed: 12/11/2022] Open
Abstract
Calcium transfer from the endoplasmic reticulum (ER) to mitochondria is a critical contributor to apoptosis. B cell lymphoma 2 (BCL-2) ovarian killer (BOK) localizes to the ER and binds the inositol 1,4,5-trisphosophate receptor (IP3R). Here, we show that BOK is necessary for baseline mitochondrial calcium levels and stimulus-induced calcium transfer from the ER to the mitochondria. Murine embryonic fibroblasts deficient for BOK have decreased proximity of the ER to the mitochondria and altered protein composition of mitochondria-associated membranes (MAMs), which form essential calcium microdomains. Rescue of the ER-mitochondrial juxtaposition with drug-inducible interorganelle linkers reveals a kinetic disruption, which when overcome in Bok−/− cells is still insufficient to rescue thapsigargin-induced calcium transfer and apoptosis. Likewise, a BOK mutant unable to interact with IP3R restores ER-mitochondrial proximity, but not ER-mitochondrial calcium transfer, MAM protein composition, or apoptosis. This work identifies the dynamic coordination of ER-mitochondrial contact by BOK as an important control point for apoptosis. Carpio et al. demonstrate that the proapoptotic BCL-2 family member BOK is present in mitochondrial associated membranes (MAMs). The interaction of BOK with the IP3Rs is critical for its regulation of Ca2+ transfer to the mitochondria, ER-mitochondrial contact sites, and apoptosis.
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Affiliation(s)
- Marcos A Carpio
- Department of Pathology, Yale School of Medicine, New Haven, CT 06525, USA
| | - Robert E Means
- Department of Pathology, Yale School of Medicine, New Haven, CT 06525, USA
| | - Allison L Brill
- Department of Cellular and Molecular Physiology, Yale School of Medicine, New Haven, CT 06525, USA
| | - Alva Sainz
- Department of Pathology, Yale School of Medicine, New Haven, CT 06525, USA
| | - Barbara E Ehrlich
- Department of Cellular and Molecular Physiology, Yale School of Medicine, New Haven, CT 06525, USA; Department of Pharmacology, Yale School of Medicine, New Haven, CT 06525, USA
| | - Samuel G Katz
- Department of Pathology, Yale School of Medicine, New Haven, CT 06525, USA.
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9
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Role of IP3 Receptors in Shaping the Carotid Chemoreceptor Response to Hypoxia But Not to Hypercapnia in the Rat Carotid Body: An Evidence Review. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021. [PMID: 32767266 DOI: 10.1007/5584_2020_561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/19/2023]
Abstract
This article addresses the disparity in the transduction pathways for hypoxic and hypercapnic stimuli in carotid body glomus cells. We investigated and reviewed the experimental evidence showing that the response to hypoxia, but not to hypercapnia, is mediated by 1,4,5-inositol triphosphate receptors (IP3R/s) regulating the intracellular calcium content [Ca2+]c in glomus cells. The rationale was based on the past observations that inhibition of oxidative phosphorylation leads to the explicit inhibition of the hypoxic chemoreflex. [Ca2+]c changes were measured using cellular Ca2+-sensitive fluorescent probes, and carotid sinus nerve (CSN) sensory discharge was recorded with bipolar electrodes in in vitro perfused-superfused rat carotid body preparations. The cell-permeant, 2-amino-ethoxy-diphenyl-borate (2-APB; 100 μM) and curcumin (50 μM) were used as the inhibitors of IP3R/s. These agents suppressed the [Ca2+]c, and CSN discharge increases in hypoxia but not in hypercapnia, leading to the conclusion that only the hypoxic effects were mediated via modulation of IP3R/s. The ATP-induced Ca2+ release from intracellular stores in a Ca2+-free medium was blocked with 2-APB, supporting this conclusion.
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10
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Dejos C, Gkika D, Cantelmo AR. The Two-Way Relationship Between Calcium and Metabolism in Cancer. Front Cell Dev Biol 2020; 8:573747. [PMID: 33282859 PMCID: PMC7691323 DOI: 10.3389/fcell.2020.573747] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Accepted: 10/12/2020] [Indexed: 12/14/2022] Open
Abstract
Calcium ion (Ca2+) signaling is critical to many physiological processes, and its kinetics and subcellular localization are tightly regulated in all cell types. All Ca2+ flux perturbations impact cell function and may contribute to various diseases, including cancer. Several modulators of Ca2+ signaling are attractive pharmacological targets due to their accessibility at the plasma membrane. Despite this, the number of specific inhibitors is still limited, and to date there are no anticancer drugs in the clinic that target Ca2+ signaling. Ca2+ dynamics are impacted, in part, by modifications of cellular metabolic pathways. Conversely, it is well established that Ca2+ regulates cellular bioenergetics by allosterically activating key metabolic enzymes and metabolite shuttles or indirectly by modulating signaling cascades. A coordinated interplay between Ca2+ and metabolism is essential in maintaining cellular homeostasis. In this review, we provide a snapshot of the reciprocal interaction between Ca2+ and metabolism and discuss the potential consequences of this interplay in cancer cells. We highlight the contribution of Ca2+ to the metabolic reprogramming observed in cancer. We also describe how the metabolic adaptation of cancer cells influences this crosstalk to regulate protumorigenic signaling pathways. We suggest that the dual targeting of these processes might provide unprecedented opportunities for anticancer strategies. Interestingly, promising evidence for the synergistic effects of antimetabolites and Ca2+-modulating agents is emerging.
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Affiliation(s)
- Camille Dejos
- Univ. Lille, Inserm, U1003 - PHYCEL - Physiologie Cellulaire, Lille, France
| | - Dimitra Gkika
- Univ. Lille, CNRS, INSERM, CHU Lille, Centre Oscar Lambret, UMR 9020-UMR 1277-Canther-Cancer Heterogeneity, Plasticity and Resistance to Therapies, Lille, France.,Institut Universitaire de France (IUF), Paris, France
| | - Anna Rita Cantelmo
- Univ. Lille, Inserm, U1003 - PHYCEL - Physiologie Cellulaire, Lille, France
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Dissecting Cellular Mechanisms of Long-Chain Acylcarnitines-Driven Cardiotoxicity: Disturbance of Calcium Homeostasis, Activation of Ca 2+-Dependent Phospholipases, and Mitochondrial Energetics Collapse. Int J Mol Sci 2020; 21:ijms21207461. [PMID: 33050414 PMCID: PMC7589681 DOI: 10.3390/ijms21207461] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Revised: 10/05/2020] [Accepted: 10/07/2020] [Indexed: 01/16/2023] Open
Abstract
Long-chain acylcarnitines (LCAC) are implicated in ischemia-reperfusion (I/R)-induced myocardial injury and mitochondrial dysfunction. Yet, molecular mechanisms underlying involvement of LCAC in cardiac injury are not sufficiently studied. It is known that in cardiomyocytes, palmitoylcarnitine (PC) can induce cytosolic Ca2+ accumulation, implicating L-type calcium channels, Na+/Ca2+ exchanger, and Ca2+-release from sarcoplasmic reticulum (SR). Alternatively, PC can evoke dissipation of mitochondrial potential (ΔΨm) and mitochondrial permeability transition pore (mPTP). Here, to dissect the complex nature of PC action on Ca2+ homeostasis and oxidative phosphorylation (OXPHOS) in cardiomyocytes and mitochondria, the methods of fluorescent microscopy, perforated path-clamp, and mitochondrial assays were used. We found that LCAC in dose-dependent manner can evoke Ca2+-sparks and oscillations, long-living Ca2+ enriched microdomains, and, finally, Ca2+ overload leading to hypercontracture and cardiomyocyte death. Collectively, PC-driven cardiotoxicity involves: (I) redistribution of Ca2+ from SR to mitochondria with minimal contribution of external calcium influx; (II) irreversible inhibition of Krebs cycle and OXPHOS underlying limited mitochondrial Ca2+ buffering; (III) induction of mPTP reinforced by PC-calcium interplay; (IV) activation of Ca2+-dependent phospholipases cPLA2 and PLC. Based on the inhibitory analysis we may suggest that simultaneous inhibition of both phospholipases could be an effective strategy for protection against PC-mediated toxicity in cardiomyocytes.
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12
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Medini H, Cohen T, Mishmar D. Mitochondria Are Fundamental for the Emergence of Metazoans: On Metabolism, Genomic Regulation, and the Birth of Complex Organisms. Annu Rev Genet 2020; 54:151-166. [PMID: 32857636 DOI: 10.1146/annurev-genet-021920-105545] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Out of many intracellular bacteria, only the mitochondria and chloroplasts abandoned their independence billions of years ago and became endosymbionts within the host eukaryotic cell. Consequently, one cannot grow eukaryotic cells without their mitochondria, and the mitochondria cannot divide outside of the cell, thus reflecting interdependence. Here, we argue that such interdependence underlies the fundamental role of mitochondrial activities in the emergence of metazoans. Several lines of evidence support our hypothesis: (a) Differentiation and embryogenesis rely on mitochondrial function; (b) mitochondrial metabolites are primary precursors for epigenetic modifications (such as methyl and acetyl), which are critical for chromatin remodeling and gene expression, particularly during differentiation and embryogenesis; and (c) mitonuclear coregulation adapted to accommodate both housekeeping and tissue-dependent metabolic needs. We discuss the evolution of the unique mitochondrial genetic system, mitochondrial metabolites, mitonuclear coregulation, and their critical roles in the emergence of metazoans and in human disorders.
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Affiliation(s)
- Hadar Medini
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva 8410501 Israel;
| | - Tal Cohen
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva 8410501 Israel;
| | - Dan Mishmar
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva 8410501 Israel;
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13
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Verma G, Dixit A, Nunemaker CS. A Putative Prohibitin-Calcium Nexus in β-Cell Mitochondria and Diabetes. J Diabetes Res 2020; 2020:7814628. [PMID: 33354575 PMCID: PMC7737164 DOI: 10.1155/2020/7814628] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 08/01/2020] [Accepted: 08/05/2020] [Indexed: 12/21/2022] Open
Abstract
The role of mitochondria in apoptosis is well known; however, the mechanisms linking mitochondria to the proapoptotic effects of proinflammatory cytokines, hyperglycemia, and glucolipotoxicity are not completely understood. Complex Ca2+ signaling has emerged as a critical contributor to these proapoptotic effects and has gained significant attention in regulating the signaling processes of mitochondria. In pancreatic β-cells, Ca2+ plays an active role in β-cell function and survival. Prohibitin (PHB), a mitochondrial chaperone, is actively involved in maintaining the architecture of mitochondria. However, its possible interaction with Ca2+-activated signaling pathways has not been explored. The present review aims to examine potential crosstalk between Ca2+ signaling and PHB function in pancreatic β-cells. Moreover, this review will focus on the effects of cytokines and glucolipotoxicity on Ca2+ signaling and its possible interaction with PHB. Improved understanding of this important mitochondrial protein may aid in the design of more targeted drugs to identify specific pathways involved with stress-induced dysfunction in the β-cell.
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Affiliation(s)
- Gaurav Verma
- Molecular Metabolism, Lund University Diabetes Centre, Malmö -21428, Sweden
- School of Biotechnology, Jawaharlal Nehru University, -110067, New Delhi, India
| | - Aparna Dixit
- School of Biotechnology, Jawaharlal Nehru University, -110067, New Delhi, India
| | - Craig S. Nunemaker
- HCOM-Biomedical Sciences, Ohio University, Athens Camp, US-45701 Ohio, USA
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14
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Jung S, Kwon JO, Kim MK, Song MK, Kim B, Lee ZH, Kim HH. Mitofusin 2, a mitochondria-ER tethering protein, facilitates osteoclastogenesis by regulating the calcium-calcineurin-NFATc1 axis. Biochem Biophys Res Commun 2019; 516:202-208. [DOI: 10.1016/j.bbrc.2019.06.017] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Accepted: 06/03/2019] [Indexed: 11/27/2022]
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15
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Molecular Mechanisms of Leucine Zipper EF-Hand Containing Transmembrane Protein-1 Function in Health and Disease. Int J Mol Sci 2019; 20:ijms20020286. [PMID: 30642051 PMCID: PMC6358941 DOI: 10.3390/ijms20020286] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Revised: 01/08/2019] [Accepted: 01/09/2019] [Indexed: 02/07/2023] Open
Abstract
Mitochondrial calcium (Ca2+) uptake shapes cytosolic Ca2+ signals involved in countless cellular processes and more directly regulates numerous mitochondrial functions including ATP production, autophagy and apoptosis. Given the intimate link to both life and death processes, it is imperative that mitochondria tightly regulate intramitochondrial Ca2+ levels with a high degree of precision. Among the Ca2+ handling tools of mitochondria, the leucine zipper EF-hand containing transmembrane protein-1 (LETM1) is a transporter protein localized to the inner mitochondrial membrane shown to constitute a Ca2+/H+ exchanger activity. The significance of LETM1 to mitochondrial Ca2+ regulation is evident from Wolf-Hirschhorn syndrome patients that harbor a haplodeficiency in LETM1 expression, leading to dysfunctional mitochondrial Ca2+ handling and from numerous types of cancer cells that show an upregulation of LETM1 expression. Despite the significance of LETM1 to cell physiology and pathophysiology, the molecular mechanisms of LETM1 function remain poorly defined. In this review, we aim to provide an overview of the current understanding of LETM1 structure and function and pinpoint the knowledge gaps that need to be filled in order to unravel the underlying mechanistic basis for LETM1 function.
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16
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Distelhorst CW. Targeting Bcl-2-IP 3 receptor interaction to treat cancer: A novel approach inspired by nearly a century treating cancer with adrenal corticosteroid hormones. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2018; 1865:1795-1804. [PMID: 30053503 DOI: 10.1016/j.bbamcr.2018.07.020] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Revised: 07/18/2018] [Accepted: 07/19/2018] [Indexed: 12/12/2022]
Abstract
Bcl-2 inhibits cell death by at least two different mechanisms. On the one hand, its BH3 domain binds to pro-apoptotic proteins such as Bim and prevents apoptosis induction. On the other hand, the BH4 domain of Bcl-2 binds to the inositol 1,4,5-trisphosphate receptor (IP3R), preventing Ca2+ signals that mediate cell death. In normal T-cells, Bcl-2 levels increase during the immune response, protecting against cell death, and then decline as apoptosis ensues and the immune response dissipates. But in many cancers Bcl-2 is aberrantly expressed and exploited to prevent cell death by inhibiting IP3R-mediated Ca2+ elevation. This review summarizes what is known about the mechanism of Bcl-2's control over IP3R-mediated Ca2+ release and cell death induction. Early insights into the role of Ca2+ elevation in corticosteroid-mediated cell death serves as a model for how targeting IP3R-mediated Ca2+ elevation can be a highly effective therapeutic approach for different types of cancer. Moreover, the successful development of ABT-199 (Venetoclax), a small molecule targeting the BH3 domain of Bcl-2 but without effects on Ca2+, serves as proof of principle that targeting Bcl-2 can be an effective therapeutic approach. BIRD-2, a synthetic peptide that inhibits Bcl-2-IP3R interaction, induces cell death induction in ABT-199 (Venetoclax)-resistant cancer models, attesting to the value of developing therapeutic agents that selectively target Bcl-2-IP3R interaction, inducing Ca2+-mediated cell death.
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Affiliation(s)
- Clark W Distelhorst
- Case Western University School of Medicine, Case Comprehensive Cancer Center, University Hospitals Cleveland Medical Center, Cleveland, OH 44106, United States of America.
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17
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Function, regulation and physiological role of the mitochondrial Na + /Ca 2+ exchanger, NCLX. CURRENT OPINION IN PHYSIOLOGY 2018. [DOI: 10.1016/j.cophys.2018.02.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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18
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Baek JH, Lee J, Yun HS, Lee CW, Song JY, Um HD, Park JK, Park IC, Kim JS, Kim EH, Hwang SG. Kinesin light chain-4 depletion induces apoptosis of radioresistant cancer cells by mitochondrial dysfunction via calcium ion influx. Cell Death Dis 2018; 9:496. [PMID: 29717133 PMCID: PMC5931584 DOI: 10.1038/s41419-018-0549-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Revised: 03/23/2018] [Accepted: 03/27/2018] [Indexed: 01/18/2023]
Abstract
Kinesins act as molecular microtubule-dependent motor proteins and have various important cellular functions related to cell division, intracellular transport, and membrane trafficking. However, the function of kinesin light chain 4 (KLC4) in cancer, especially radioresistance, has not been previously described. Thus, we investigated KLC4 function in lung cancer cells and radioresistant R-H460 cells by analyzing alterations in radiosensitivity after gene knockdown with siRNA and by evaluating cellular phenotypes and xenograft tumor growth. KLC4 was upregulated in human lung cancer cell lines. Moreover, in paired clinical specimens of lung cancer patients, KLC4 expression was significantly higher in tumor tissues than in paired adjacent normal tissues. Fluorescence-activated cell sorting (FACS) analysis showed that apoptosis rates and cleaved poly (ADP-ribose) polymerase (PARP) and cleaved caspase-3 levels in KLC4-knockdown lung cancer cells were significantly increased compared with those in control cells. Colony formation decreased as the radiation dose increased in KLC4-knockdown lung cancer cells, demonstrating an essential role for KLC4 in radioresistance. Importantly, KLC4 silencing suppressed tumor growth in an in vivo xenograft model, accompanied by increased apoptosis. Finally, KLC4-knockdown cells exhibited impaired mitochondrial respiration, increased mitochondrial reactive oxygen species production, and enhanced mitochondrial calcium uptake, resulting in mitochondrial dysfunction. Thus, KLC4 as a kinesin superfamily-targeted therapy may represent a novel, effective anticancer strategy, particularly for patients showing radioresistance.
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Affiliation(s)
- Jeong-Hwa Baek
- Division of Applied Radiation Bioscience, Korea Institute of Radiological & Medical Sciences, Seoul, 01812, Korea
- Department of Molecular Cell Biology, Sungkyunkwan University School of Medicine, Suwon, 440-746, Korea
| | - Janet Lee
- Division of Applied Radiation Bioscience, Korea Institute of Radiological & Medical Sciences, Seoul, 01812, Korea
| | - Hong Shik Yun
- Division of Applied Radiation Bioscience, Korea Institute of Radiological & Medical Sciences, Seoul, 01812, Korea
| | - Chang-Woo Lee
- Department of Molecular Cell Biology, Sungkyunkwan University School of Medicine, Suwon, 440-746, Korea
| | - Jie-Young Song
- Division of Applied Radiation Bioscience, Korea Institute of Radiological & Medical Sciences, Seoul, 01812, Korea
| | - Hong-Duck Um
- Division of Applied Radiation Bioscience, Korea Institute of Radiological & Medical Sciences, Seoul, 01812, Korea
| | - Jong Kuk Park
- Division of Applied Radiation Bioscience, Korea Institute of Radiological & Medical Sciences, Seoul, 01812, Korea
| | - In-Chul Park
- Division of Applied Radiation Bioscience, Korea Institute of Radiological & Medical Sciences, Seoul, 01812, Korea
| | - Jae-Sung Kim
- Division of Applied Radiation Bioscience, Korea Institute of Radiological & Medical Sciences, Seoul, 01812, Korea
| | - Eun Ho Kim
- Division of Applied Radiation Bioscience, Korea Institute of Radiological & Medical Sciences, Seoul, 01812, Korea.
| | - Sang-Gu Hwang
- Division of Applied Radiation Bioscience, Korea Institute of Radiological & Medical Sciences, Seoul, 01812, Korea.
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19
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Xie Q, Xu Y, Gao W, Zhang Y, Su J, Liu Y, Guo Y, Dou M, Hu K, Sun L. TAT‑fused IP3R‑derived peptide enhances cisplatin sensitivity of ovarian cancer cells by increasing ER Ca2+ release. Int J Mol Med 2017; 41:809-817. [PMID: 29207009 PMCID: PMC5752180 DOI: 10.3892/ijmm.2017.3260] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Accepted: 10/25/2017] [Indexed: 01/04/2023] Open
Abstract
Ovarian cancer is the most common gynecological malignancy. At present, cisplatin is used to treat ovarian cancer; however, the development of cisplatin resistance during therapy is a common obstacle to achieving favorable outcomes. Recently, the B‑cell lymphoma 2 (Bcl‑2) BH4 domain has been reported to mediate the prosurvival activity of Bcl‑2 in cancer; however, the involvement of the BH4 domain of Bcl‑2 in the cisplatin resistance of ovarian carcinoma cells is not entirely clear. In this study, we observed the cytoplasmic and mitochondrial levels of Ca2+ by confocal laser microscopy. We also detected cell apoptosis using western blot analysis and flow cytometry. The present study demonstrated that TAT‑fused inositol 1,4,5‑trisphosphate receptor‑derived peptide (TAT‑IDPS), which targets the BH4 domain of Bcl‑2, increased cisplatin‑induced Ca2+ flux from the endoplasmic reticulum (ER) into the cytosol and mitochondria. In addition, TAT‑IDPS increased cisplatin‑induced expression of mitochondrial apoptosis‑associated proteins and ER stress‑associated proteins. These results indicated that TAT‑IDPS may enhance the cytotoxicity of cisplatin toward ovarian carcinoma cells by increasing ER Ca2+ release.
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Affiliation(s)
- Qi Xie
- Department of Pathophysiology, Basic College of Medicine, Jilin University, Changchun, Jilin 130021, P.R. China
| | - Ye Xu
- Department of Histology and Embryology, Basic College of Medicine, Jilin Medical University, Jilin, Jilin 132013, P.R. China
| | - Weinan Gao
- Department of Clinical Medicine, College of Clinical Medicine, Jilin University, Changchun, Jilin 130021, P.R. China
| | - Yong Zhang
- Department of Pathophysiology, Basic College of Medicine, Jilin University, Changchun, Jilin 130021, P.R. China
| | - Jing Su
- Department of Pathophysiology, Basic College of Medicine, Jilin University, Changchun, Jilin 130021, P.R. China
| | - Yanan Liu
- Department of Pathophysiology, Basic College of Medicine, Jilin University, Changchun, Jilin 130021, P.R. China
| | - Yuting Guo
- Department of Histology and Embryology, Basic College of Medicine, Jilin Medical University, Jilin, Jilin 132013, P.R. China
| | - Minghan Dou
- Department of Histology and Embryology, Basic College of Medicine, Jilin Medical University, Jilin, Jilin 132013, P.R. China
| | - Kebang Hu
- Department of Urology, First Hospital of Jilin University, Changchun, Jilin 130031, P.R. China
| | - Liankun Sun
- Department of Pathophysiology, Basic College of Medicine, Jilin University, Changchun, Jilin 130021, P.R. China
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20
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Ba Q, Yang G. Intracellular organelle networks: Understanding their organization and communication through systems-level modeling and analysis. ACTA ACUST UNITED AC 2017. [DOI: 10.1007/s11515-016-1436-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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21
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Arena G, Valente EM. PINK1 in the limelight: multiple functions of an eclectic protein in human health and disease. J Pathol 2016; 241:251-263. [PMID: 27701735 DOI: 10.1002/path.4815] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2016] [Revised: 09/04/2016] [Accepted: 09/23/2016] [Indexed: 01/02/2023]
Abstract
The gene PINK1 [phosphatase and tensin homologue (PTEN)-induced putative kinase 1] encodes a serine/threonine kinase which was initially linked to the pathogenesis of a familial form of Parkinson's disease. Research on PINK1 has recently unravelled that its multiple functions extend well beyond neuroprotection, implicating this eclectic protein in a growing number of human pathologies, including cancer, diabetes, cardiopulmonary dysfunctions, and inflammation. Extensive studies have identified PINK1 as a crucial player in the mitochondrial quality control pathway, required to label damaged mitochondria and promote their elimination through an autophagic process (mitophagy). Mounting evidence now indicates that PINK1 activities are not restricted solely to mitophagy, and that different subcellular and even sub-mitochondrial pools of PINK1 are involved in distinct signalling cascades to regulate cell metabolism and survival. In this review, we provide a concise overview on the different functions of PINK1 and their potential role in human diseases. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
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Affiliation(s)
- Giuseppe Arena
- Institut de Recherche en Cancérologie de Montpellier (IRCM), Montpellier, France.,INSERM, U1194, Montpellier, France.,Université Montpellier, Montpellier, France.,Institut Régional du Cancer Montpellier, Montpellier, France
| | - Enza Maria Valente
- Section of Neurosciences, Department of Medicine and Surgery, University of Salerno, Salerno, Italy.,Neurogenetics Unit, IRCCS Santa Lucia Foundation, Rome, Italy
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22
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Greenberg EF, Lavik AR, Distelhorst CW. Bcl-2 regulation of the inositol 1,4,5-trisphosphate receptor and calcium signaling in normal and malignant lymphocytes: potential new target for cancer treatment. BIOCHIMICA ET BIOPHYSICA ACTA 2014; 1843:2205-10. [PMID: 24642270 PMCID: PMC4119508 DOI: 10.1016/j.bbamcr.2014.03.008] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2013] [Revised: 03/07/2014] [Accepted: 03/10/2014] [Indexed: 01/23/2023]
Abstract
The anti-apoptotic protein Bcl-2 is a versatile regulator of cell survival. Its interactions with its own pro-apoptotic family members are widely recognized for their role in promoting the survival of cancer cells. These interactions are thus being targeted for cancer treatment. Less widely recognized is the interaction of Bcl-2 with the inositol 1,4,5-trisphosphate receptor (InsP3R), an InsP3-gated Ca(2+) channel located on the endoplasmic reticulum. The nature of this interaction, the mechanism by which it controls Ca(2+) release from the ER, its role in T-cell development and survival, and the possibility of targeting it as a novel cancer treatment strategy are summarized in this review. This article is part of a Special Issue entitled: Calcium signaling in health and disease. Guest Editors: Geert Bultynck, Jacques Haiech, Claus W. Heizmann, Joachim Krebs, and Marc Moreau.
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Affiliation(s)
- Edward F Greenberg
- Division of Hematology/Oncology, Case Western Reserve University School of Medicine, Case Comprehensive Cancer Center, University Hospitals Case Medical Center, USA; MetroHealth Medical Center, USA.
| | - Andrew R Lavik
- Division of Hematology/Oncology, Case Western Reserve University School of Medicine, Case Comprehensive Cancer Center, University Hospitals Case Medical Center, USA.
| | - Clark W Distelhorst
- Division of Hematology/Oncology, Case Western Reserve University School of Medicine, Case Comprehensive Cancer Center, University Hospitals Case Medical Center, USA.
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23
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Naon D, Scorrano L. At the right distance: ER-mitochondria juxtaposition in cell life and death. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2014; 1843:2184-94. [PMID: 24875902 DOI: 10.1016/j.bbamcr.2014.05.011] [Citation(s) in RCA: 129] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Revised: 05/18/2014] [Accepted: 05/19/2014] [Indexed: 11/29/2022]
Abstract
The interface between mitochondria and the endoplasmic reticulum is emerging as a crucial hub for calcium signalling, apoptosis, autophagy and lipid biosynthesis, with far reaching implications in cell life and death and in the regulation of mitochondrial and endoplasmic reticulum function. Here we review our current knowledge on the structural and functional aspects of this interorganellar juxtaposition. This article is part of a Special Issue entitled: Calcium Signaling In Health and Disease. Guest Editors: Geert Bultynck, Jacques Haiech, Claus W. Heizmann, Joachim Krebs, and Marc Moreau.
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Affiliation(s)
- Deborah Naon
- Dulbecco-Telethon Institute, Venetian Institute of Molecular Medicine, Via Orus 2, 35129 Padua, Italy; Department of Biology, University of Padua, Via G. Colombo 3, 35121 Padua, Italy
| | - Luca Scorrano
- Dulbecco-Telethon Institute, Venetian Institute of Molecular Medicine, Via Orus 2, 35129 Padua, Italy; Department of Biology, University of Padua, Via G. Colombo 3, 35121 Padua, Italy.
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24
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Kimura H. The physiological role of hydrogen sulfide and beyond. Nitric Oxide 2014; 41:4-10. [PMID: 24491257 DOI: 10.1016/j.niox.2014.01.002] [Citation(s) in RCA: 209] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2013] [Revised: 01/20/2014] [Accepted: 01/22/2014] [Indexed: 02/08/2023]
Abstract
Hydrogen sulfide (H2S) has been considered to be a physiological mediator since the identification of endogenous sulfides in the mammalian brain. H2S is produced from L-cysteine by enzymes such as cystathionine β-synthase (CBS), cystathionine γ-lyase (CSE), 3-mercaptopyruvate sulfurtransferase (3MST), and cysteine aminotransferase (CAT). CSE and CAT are regulated by Ca(2+). At steady-state low intracellular concentrations of Ca(2+), CSE and the 3MST/CAT pathway produce H2S. However, after intracellular concentrations of Ca(2+) increase in stimulated cells, the production of H2S by these enzymes decreases. We recently identified a fourth pathway, by which H2S is produced from D-cysteine by the enzymes D-amino acid oxidase (DAO) and 3MST. This pathway is mainly localized in the cerebellum and the kidney. The production of H2S from D-cysteine is 80 times more efficient than that from L-cysteine in the kidney, and the administration of D-cysteine to mice ameliorates renal ischemia-reperfusion injury more effectively than L-cysteine. These results suggest that D-cysteine might be used to treat renal diseases or even increase the success of kidney transplantation. We found that H2S-derived polysulfides exist in the brain and activate transient receptor potential ankyrin-1 (TRPA1) channels 300 times more potently than H2S. Although TRPA1 channels mediate sensory transduction and respond to a variety of stimuli, including cold temperature, pungent compounds and environmental irritants, their endogenous ligand(s) has not been identified. The sulfane sulfur of polysulfides is a reactive electrophile that is readily transferred to a nucleophilic protein thiolate to generate the protein persulfide or bound sulfane sulfur by sulfhydration (as referred to as sulfuration). The bound sulfane sulfur-producing activity of polysulfides is much greater than that of H2S. This review focuses on the physiological roles of H2S and H2S-derived polysulfides as signaling molecules.
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Affiliation(s)
- Hideo Kimura
- National Institute of Neuroscience, National Center of Neurology and Psychiatry, Kodaira, Tokyo 187-8502, Japan.
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25
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MAM (mitochondria-associated membranes) in mammalian cells: lipids and beyond. Biochim Biophys Acta Mol Cell Biol Lipids 2013; 1841:595-609. [PMID: 24316057 DOI: 10.1016/j.bbalip.2013.11.014] [Citation(s) in RCA: 446] [Impact Index Per Article: 40.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2013] [Revised: 11/21/2013] [Accepted: 11/27/2013] [Indexed: 12/15/2022]
Abstract
One mechanism by which communication between the endoplasmic reticulum (ER) and mitochondria is achieved is by close juxtaposition between these organelles via mitochondria-associated membranes (MAM). The MAM consist of a region of the ER that is enriched in several lipid biosynthetic enzyme activities and becomes reversibly tethered to mitochondria. Specific proteins are localized, sometimes transiently, in the MAM. Several of these proteins have been implicated in tethering the MAM to mitochondria. In mammalian cells, formation of these contact sites between MAM and mitochondria appears to be required for key cellular events including the transport of calcium from the ER to mitochondria, the import of phosphatidylserine into mitochondria from the ER for decarboxylation to phosphatidylethanolamine, the formation of autophagosomes, regulation of the morphology, dynamics and functions of mitochondria, and cell survival. This review focuses on the functions proposed for MAM in mediating these events in mammalian cells. In light of the apparent involvement of MAM in multiple fundamental cellular processes, recent studies indicate that impaired contact between MAM and mitochondria might underlie the pathology of several human neurodegenerative diseases, including Alzheimer's disease. Moreover, MAM has been implicated in modulating glucose homeostasis and insulin resistance, as well as in some viral infections.
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Abstract
Intracellular free Ca(2+) ([Ca(2+)]i) is a highly versatile second messenger that regulates a wide range of functions in every type of cell and tissue. To achieve this versatility, the Ca(2+) signaling system operates in a variety of ways to regulate cellular processes that function over a wide dynamic range. This is particularly well exemplified for Ca(2+) signals in the liver, which modulate diverse and specialized functions such as bile secretion, glucose metabolism, cell proliferation, and apoptosis. These Ca(2+) signals are organized to control distinct cellular processes through tight spatial and temporal coordination of [Ca(2+)]i signals, both within and between cells. This article will review the machinery responsible for the formation of Ca(2+) signals in the liver, the types of subcellular, cellular, and intercellular signals that occur, the physiological role of Ca(2+) signaling in the liver, and the role of Ca(2+) signaling in liver disease.
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Affiliation(s)
- Maria Jimena Amaya
- Section of Digestive Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
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27
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Abstract
Ca²⁺ plays a crucial role in connecting membrane excitability with contraction in myocardium. The hallmark features of heart failure are mechanical dysfunction and arrhythmias; defective intracellular Ca²⁺ homeostasis is a central cause of contractile dysfunction and arrhythmias in failing myocardium. Defective Ca²⁺ homeostasis in heart failure can result from pathological alteration in the expression and activity of an increasingly understood collection of Ca²⁺ homeostatic and structural proteins, ion channels, and enzymes. This review focuses on the molecular mechanisms of defective Ca²⁺ cycling in heart failure and considers how fundamental understanding of these pathways may translate into novel and innovative therapies.
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Affiliation(s)
- Min Luo
- Division of Cardiovascular Medicine, Department of Internal Medicine, Cardiovascular Research Center, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
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28
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Lawrence EJ, Mandato CA. Mitochondria localize to the cleavage furrow in mammalian cytokinesis. PLoS One 2013; 8:e72886. [PMID: 23991162 PMCID: PMC3749163 DOI: 10.1371/journal.pone.0072886] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2013] [Accepted: 07/21/2013] [Indexed: 01/08/2023] Open
Abstract
Mitochondria are dynamic organelles with multiple cellular functions, including ATP production, calcium buffering, and lipid biosynthesis. Several studies have shown that mitochondrial positioning is regulated by the cytoskeleton during cell division in several eukaryotic systems. However, the distribution of mitochondria during mammalian cytokinesis and whether the distribution is regulated by the cytoskeleton has not been examined. Using live spinning disk confocal microscopy and quantitative analysis of mitochondrial fluorescence intensity, we demonstrate that mitochondria are recruited to the cleavage furrow during cytokinesis in HeLa cells. After anaphase onset, the mitochondria are recruited towards the site of cleavage furrow formation, where they remain enriched as the furrow ingresses and until cytokinesis completion. Furthermore, we show that recruitment of mitochondria to the furrow occurs in multiple mammalian cells lines as well as in monopolar, bipolar, and multipolar divisions, suggesting that the mechanism of recruitment is conserved and robust. Using inhibitors of cytoskeleton dynamics, we show that the microtubule cytoskeleton, but not actin, is required to transport mitochondria to the cleavage furrow. Thus, mitochondria are specifically recruited to the cleavage furrow in a microtubule-dependent manner during mammalian cytokinesis. Two possible reasons for this could be to localize mitochondrial function to the furrow to facilitate cytokinesis and / or ensure accurate mitochondrial inheritance.
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Affiliation(s)
| | - Craig A. Mandato
- Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec, Canada
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Mikami Y, Shibuya N, Ogasawara Y, Kimura H. Hydrogen sulfide is produced by cystathionine γ-lyase at the steady-state low intracellular Ca(2+) concentrations. Biochem Biophys Res Commun 2013; 431:131-5. [PMID: 23313510 DOI: 10.1016/j.bbrc.2013.01.010] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2012] [Accepted: 01/04/2013] [Indexed: 11/16/2022]
Abstract
Hydrogen sulfide (H(2)S) is recognized as a physiologic mediator produced in a variety of tissues. It is produced by three enzymes, cystathionine β-synthase (CBS), cystathionine γ-lyase (CSE) and 3-mercaptopyruvate sulfurtransferase (3MST). However, the regulation of H(2)S production by CSE has not well been understood. Here we show that H(2)S producing activity of CSE is regulated by intracellular Ca(2+) concentrations. In the presence of pyridoxal 5'-phosphate (PLP) CSE efficiently produces H(2)S at the steady-state low Ca(2+) concentrations but is suppressed at high Ca(2+) concentrations. In the absence of PLP H(2)S production maintains the suppressed levels at high Ca(2+) concentrations and decreased further at low Ca(2+) concentrations. These observations suggest that CSE produces H(2)S at the steady-state in cells and that the production is suppressed when the intracellular Ca(2+) concentrations are increased.
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Affiliation(s)
- Yoshinori Mikami
- Department of Molecular Pharmacology, National Institute of Neuroscience, National Center of Neurology and Psychiatry, 4-1-1 Ogawahigashi, Kodaira, Tokyo 187-8502, Japan
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Shibuya N, Kimura H. Production of hydrogen sulfide from d-cysteine and its therapeutic potential. Front Endocrinol (Lausanne) 2013; 4:87. [PMID: 23882260 PMCID: PMC3712494 DOI: 10.3389/fendo.2013.00087] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2013] [Accepted: 07/01/2013] [Indexed: 12/25/2022] Open
Abstract
Accumulating evidence shows that H2S has physiological functions in various tissues and organs. It includes regulation of neuronal activity, vascular tension, a release of insulin, and protection of the heart, kidney, and brain from ischemic insult. H2S is produced by enzymes from l-cysteine; cystathionine β-synthase, cystathionine γ-lyase, and 3-mercaptopyruvate sulfurtransferase (3MST) along with cysteine aminotransferase. We recently discovered an additional pathway for the production of H2S from d-cysteine. d-Amino acid oxidase provides 3-mercaptopyruvate for 3MST to produce H2S. d-Cysteine protects cerebellar neurons from oxidative stress and attenuates ischemia-reperfusion injury caused in the kidney more effectively than l-cysteine. This review focuses on a novel pathway for the production of H2S and its therapeutic application especially to the renal diseases.
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Affiliation(s)
- Norihiro Shibuya
- Department of Molecular Pharmacology, National Institute of Neuroscience, Kodaira, Tokyo, Japan
| | - Hideo Kimura
- Department of Molecular Pharmacology, National Institute of Neuroscience, Kodaira, Tokyo, Japan
- *Correspondence: Hideo Kimura, Department of Molecular Pharmacology, National Institute of Neuroscience, 4-1-1 Ogawahigashi, Kodaira, Tokyo 187-8502, Japan e-mail:
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31
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Taurine and Its Neuroprotective Role. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2013; 775:19-27. [DOI: 10.1007/978-1-4614-6130-2_2] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Tarasov AI, Semplici F, Li D, Rizzuto R, Ravier MA, Gilon P, Rutter GA. Frequency-dependent mitochondrial Ca(2+) accumulation regulates ATP synthesis in pancreatic β cells. Pflugers Arch 2012; 465:543-54. [PMID: 23149488 PMCID: PMC3631125 DOI: 10.1007/s00424-012-1177-9] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2012] [Revised: 10/25/2012] [Accepted: 10/29/2012] [Indexed: 12/23/2022]
Abstract
Pancreatic β cells respond to increases in glucose concentration with enhanced metabolism, the closure of ATP-sensitive K+ channels and electrical spiking. The latter results in oscillatory Ca2+ influx through voltage-gated Ca2+ channels and the activation of insulin release. The relationship between changes in cytosolic and mitochondrial free calcium concentration ([Ca2+]cyt and [Ca2+]mit, respectively) during these cycles is poorly understood. Importantly, the activation of Ca2+-sensitive intramitochondrial dehydrogenases, occurring alongside the stimulation of ATP consumption required for Ca2+ pumping and other processes, may exert complex effects on cytosolic ATP/ADP ratios and hence insulin secretion. To explore the relationship between these parameters in single primary β cells, we have deployed cytosolic (Fura red, Indo1) or green fluorescent protein-based recombinant-targeted (Pericam, 2mt8RP for mitochondria; D4ER for the ER) probes for Ca2+ and cytosolic ATP/ADP (Perceval) alongside patch-clamp electrophysiology. We demonstrate that: (1) blockade of mitochondrial Ca2+ uptake by shRNA-mediated silencing of the uniporter MCU attenuates glucose- and essentially blocks tolbutamide-stimulated, insulin secretion; (2) during electrical stimulation, mitochondria decode cytosolic Ca2+ oscillation frequency as stable increases in [Ca2+]mit and cytosolic ATP/ADP; (3) mitochondrial Ca2+ uptake rates remained constant between individual spikes, arguing against activity-dependent regulation (“plasticity”) and (4) the relationship between [Ca2+]cyt and [Ca2+]mit is essentially unaffected by changes in endoplasmic reticulum Ca2+ ([Ca2+]ER). Our findings thus highlight new aspects of Ca2+ signalling in β cells of relevance to the actions of both glucose and sulphonylureas.
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Affiliation(s)
- Andrei I Tarasov
- Section of Cell Biology, Division of Diabetes Endocrinology and Metabolism, Department of Medicine, Imperial College London, SW7 2AZ, London, UK
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33
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Non-apoptotic functions of apoptosis-regulatory proteins. EMBO Rep 2012; 13:322-30. [PMID: 22402666 DOI: 10.1038/embor.2012.19] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2011] [Accepted: 01/23/2012] [Indexed: 01/24/2023] Open
Abstract
During the past two decades, apoptotic cell death has been the subject of an intense wave of investigation, leading to the discovery of multiple gene products that govern both its induction and execution. In parallel, it has progressively become evident that most, if not all, proteins that had initially been discovered for their essential role in apoptosis also mediate a wide range of non-apoptotic functions. On the one hand, apoptotic regulators and executioners are involved in non-lethal physiological processes as diverse as cell cycle progression, differentiation, metabolism, autophagy and inflammation. On the other hand, pro-apoptotic proteins can control other modalities of programmed cell death, in particular regulated necrosis. In this review, we summarize the unconventional roles of the apoptotic core machinery from a functional perspective and discuss their pathophysiological implications.
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Koshiba T. Mitochondrial-mediated antiviral immunity. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2012; 1833:225-32. [PMID: 22440325 DOI: 10.1016/j.bbamcr.2012.03.005] [Citation(s) in RCA: 89] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 01/18/2012] [Revised: 03/02/2012] [Accepted: 03/06/2012] [Indexed: 12/28/2022]
Abstract
Mitochondria, cellular powerhouses of eukaryotes, are known to act as central hubs for multiple signal transductions. Recent research reveals that mitochondria are involved in cellular innate antiviral immunity in vertebrates, particularly mammals. Mitochondrial-mediated antiviral immunity depends on the activation of the retinoic acid-inducible gene I (RIG-I)-like receptors signal transduction pathway and on the participation of a mitochondrial outer membrane adaptor protein, called the "mitochondrial antiviral signaling (MAVS)". In this review, we discuss unexpected discoveries that are revealing how the organelles contribute to the innate immune response against RNA viruses. This article is part of a Special Issue entitled: Mitochondrial dynamics and physiology.
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Affiliation(s)
- Takumi Koshiba
- Department of Biology, Kyushu University, Higashi-ku, Fukuoka, Japan.
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35
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Mikami Y, Shibuya N, Kimura Y, Nagahara N, Yamada M, Kimura H. Hydrogen sulfide protects the retina from light-induced degeneration by the modulation of Ca2+ influx. J Biol Chem 2011; 286:39379-86. [PMID: 21937432 DOI: 10.1074/jbc.m111.298208] [Citation(s) in RCA: 114] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Hydrogen sulfide (H(2)S) has recently been recognized as a signaling molecule as well as a cytoprotectant. Cystathionine β-synthase (CBS) and cystathionine γ-lyase (CSE) are well-known as H(2)S-producing enzymes. We recently demonstrated that 3-mercaptopyruvate sulfurtransferase (3MST) along with cysteine aminotransferase (CAT) produces H(2)S in the brain and in vascular endothelium. However, the cellular distribution and regulation of these enzymes are not well understood. Here we show that 3MST and CAT are localized to retinal neurons and that the production of H(2)S is regulated by Ca(2+); H(2)S, in turn, regulates Ca(2+) influx into photoreceptor cells by activating vacuolar type H(+)-ATPase (V-ATPase). We also show that H(2)S protects retinal neurons from light-induced degeneration. The excessive levels of light exposure deteriorated photoreceptor cells and increased the number of TUNEL- and 8-hydroxy-2'-deoxyguanosine (8-OHdG)-positive cells. Degeneration was greatly suppressed in the retina of mice administered with NaHS, a donor of H(2)S. The present study provides a new insight into the regulation of H(2)S production and the modulation of the retinal transmission by H(2)S. It also shows a cytoprotective effect of H(2)S on retinal neurons and provides a basis for the therapeutic target for retinal degeneration.
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Affiliation(s)
- Yoshinori Mikami
- Department of Molecular Pharmacology, National Institute of Neuroscience, National Center of Neurology and Psychiatry, 4-1-1 Ogawahigashi, Kodaira, Tokyo 187-8502, Japan
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36
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Keil VC, Funke F, Zeug A, Schild D, Müller M. Ratiometric high-resolution imaging of JC-1 fluorescence reveals the subcellular heterogeneity of astrocytic mitochondria. Pflugers Arch 2011; 462:693-708. [PMID: 21881871 PMCID: PMC3192276 DOI: 10.1007/s00424-011-1012-8] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2011] [Accepted: 08/07/2011] [Indexed: 11/25/2022]
Abstract
Using the mitochondrial potential (ΔΨm) marker JC-1 (5,5′,6,6′-tetrachloro-1,1′,3,3′-tetraethylbenzimidazolylcarbocyanine iodide) and high-resolution imaging, we functionally analyzed mitochondria in cultured rat hippocampal astrocytes. Ratiometric detection of JC-1 fluorescence identified mitochondria with high and low ΔΨm. Mitochondrial density was highest in the perinuclear region, whereas ΔΨm tended to be higher in peripheral mitochondria. Spontaneous ΔΨm fluctuations, representing episodes of increased energization, appeared in individual mitochondria or synchronized in mitochondrial clusters. They continued upon withdrawal of extracellular Ca2+, but were antagonized by dantrolene or 2-aminoethoxydiphenylborate (2-APB). Fluo-3 imaging revealed local cytosolic Ca2+ transients with similar kinetics that also were depressed by dantrolene and 2-APB. Massive cellular Ca2+ load or metabolic impairment abolished ΔΨm fluctuations, occasionally evoking heterogeneous mitochondrial depolarizations. The detected diversity and ΔΨm heterogeneity of mitochondria confirms that even in less structurally polarized cells, such as astrocytes, specialized mitochondrial subpopulations coexist. We conclude that ΔΨm fluctuations are an indication of mitochondrial viability and are triggered by local Ca2+ release from the endoplasmic reticulum. This spatially confined organelle crosstalk contributes to the functional heterogeneity of mitochondria and may serve to adapt the metabolism of glial cells to the activity and metabolic demand of complex neuronal networks. The established ratiometric JC-1 imaging—especially combined with two-photon microscopy—enables quantitative functional analyses of individual mitochondria as well as the comparison of mitochondrial heterogeneity in different preparations and/or treatment conditions.
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Affiliation(s)
- Vera C Keil
- DFG Research Center Molecular Physiology of the Brain, Humboldtallee 23, D-37073, Göttingen, Germany
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37
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Petrović S, Veličković N, Stanojević I, Milošević M, Drakulić D, Stanojlović M, Horvat A. Inhibition of mitochondrial Na+-dependent Ca²+ efflux by 17β-estradiol in the rat hippocampus. Neuroscience 2011; 192:195-204. [PMID: 21726603 DOI: 10.1016/j.neuroscience.2011.06.030] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2010] [Revised: 05/20/2011] [Accepted: 06/09/2011] [Indexed: 01/18/2023]
Abstract
Our results, as well as those of others, have indicated that 17β-estradiol (E2) exerts its nongenomic effects in neuronal cells by affecting plasma membrane Ca(2+) flux. In neuronal cells mitochondria possess Ca(2+) buffering properties as they both sequester and release Ca(2+). The goal of this study was to examine the rapid non-genomic effect of E2 on mitochondrial Ca(2+) transport in hippocampal synaptosomes from ovariectomised rats. In addition, we aimed to determine if, and to what extent, E2 receptors participated in mitochondrial Ca(2+) transport modulation by E2 in vitro. E2-specific binding and Ca(2+) transport was monitored. At physiological E2 concentrations (0.1-1.5 nmol/L), specific E2 binding to mitochondria isolated from hippocampal synaptosomes was detected with a B(max.) and K(m) of 37.6±2.6 fmol/mg protein and 0.69±0.14 nmol/L of free E2, respectively. The main mitochondrial Ca(2+) influx mechanism is the Ruthenium Red-sensitive uniporter driven by mitochondrial membrane potential. Despite no effect of E2 on Ca(2+) influx, a physiological E2 concentration (0.5 nmol/L) protected mitochondrial membrane potential and consequently Ca(2+) influx from the uncoupling agent carbonyl cyanide 4-(trifluoromethoxy)phenylhydrazone (1 μmol/L). In neuronal cells the predominant mitochondrial Ca(2+) efflux mechanism is the Na(+)/Ca(2+) exchanger. E2 caused Ca(2+) efflux inhibition (by 46%) coupled with increased affinity of the Na(+)/Ca(2+) exchanger for Na(+). Using E2 receptor (ERα and ERβ) antagonists and agonists, we confirmed ERβ's involvement in E2-induced mitochondrial membrane potential protection as well as Ca(2+) efflux inhibition. In summary, our results indicate that the non-genomic neuromodulatory role of E2 in rat hippocampus is achieved by affecting mitochondrial Ca(2+) transport via, in part, mitochondrial ERβ.
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Affiliation(s)
- S Petrović
- Laboratory for Molecular Biology and Endocrinology, Institute of Nuclear Sciences "Vinča", University of Belgrade, PO Box 522, 11001 Belgrade, Serbia
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Bcl-2 interaction with the inositol 1,4,5-trisphosphate receptor: role in Ca(2+) signaling and disease. Cell Calcium 2011; 50:234-41. [PMID: 21628070 DOI: 10.1016/j.ceca.2011.05.011] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2011] [Revised: 05/09/2011] [Accepted: 05/10/2011] [Indexed: 01/02/2023]
Abstract
The Bcl-2 protein, best known for its ability to inhibit apoptosis, interacts with the inositol 1,4,5-trisphosphate receptor (IP(3)R) Ca(2+) channel to regulate IP(3)-mediated Ca(2+) release from the endoplasmic reticulum. This review summarizes the current state of knowledge regarding the interaction of Bcl-2, and also its homologue Bcl-xl, with the IP(3)R and how these interactions regulate Ca(2+) signaling. The dual role of these interactions in promoting prosurvival Ca(2+) signals, while at the same time inhibiting proapoptotic Ca(2+) signals, is discussed. Moreover, this review will elucidate the recently recognized importance of the Bcl-2-IP(3)R interaction in human disease.
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Abstract
The efficient functioning of the ER is indispensable for most of the cellular activities and survival. Disturbances in the physiological functions of the ER result in the activation of a complex set of signaling pathways from the ER to the cytosol and nucleus, and these are collectively known as unfolded protein response (UPR), which is aimed to compensate damage and can eventually trigger cell death if ER stress is severe or persists for a longer period. The precise molecular mechanisms that facilitate this switch in brain damage have yet to be understood completely with multiple potential participants involved. The ER stress-associated cell death pathways have been recognized in the numerous pathophysiological conditions, such as diabetes, hypoxia, ischemia/reperfusion injury, and neurodegenerative disorders, including Alzheimer's disease, Parkinson's disease, and bipolar disorder. Hence, there is an emerging need to study the basic molecular mechanisms of ER stress-mediating multiple cell survival/death signaling pathways. These molecules that regulate the ER stress response would be potential drug targets in brain diseases.
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Affiliation(s)
- Ram Raghubir
- Division of Pharmacology, Central Drug Research Institute, (CSIR), Chatter Manzil Palace, Lucknow, India
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40
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Heeman B, Van den Haute C, Aelvoet SA, Valsecchi F, Rodenburg RJ, Reumers V, Debyser Z, Callewaert G, Koopman WJH, Willems PHGM, Baekelandt V. Depletion of PINK1 affects mitochondrial metabolism, calcium homeostasis and energy maintenance. J Cell Sci 2011; 124:1115-25. [DOI: 10.1242/jcs.078303] [Citation(s) in RCA: 141] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Loss-of-function mutations in the gene encoding the mitochondrial PTEN-induced putative kinase 1 (PINK1) are a major cause of early-onset familial Parkinson's disease (PD). Recent studies have highlighted an important function for PINK1 in clearing depolarized mitochondria by mitophagy. However, the role of PINK1 in mitochondrial and cellular functioning in physiological conditions is still incompletely understood. Here, we investigate mitochondrial and cellular calcium (Ca2+) homeostasis in PINK1-knockdown and PINK1-knockout mouse cells, both in basal metabolic conditions and after physiological stimulation, using unbiased automated live single-cell imaging in combination with organelle-specific fluorescent probes. Our data reveal that depletion of PINK1 induces moderate fragmentation of the mitochondrial network, mitochondrial membrane depolarization and increased production of reactive oxygen species. This results in reduced uptake of Ca2+ by mitochondria after physiological stimulation. As a consequence, cells with knockdown or knockout of PINK1 display impaired mitochondrial ATP synthesis, which is exacerbated under conditions of increased ATP demand, thereby affecting cytosolic Ca2+ extrusion. The impairment in energy maintenance was confirmed in the brain of PINK1-knockout mice by in vivo bioluminescence imaging. Our findings demonstrate a key role for PINK1 in the regulation of mitochondrial homeostasis and energy metabolism under physiological conditions.
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Affiliation(s)
- Bavo Heeman
- Laboratory for Neurobiology and Gene Therapy, Molecular Medicine, Katholieke Universiteit Leuven, 3000 Leuven, Flanders, Belgium
| | - Chris Van den Haute
- Laboratory for Neurobiology and Gene Therapy, Molecular Medicine, Katholieke Universiteit Leuven, 3000 Leuven, Flanders, Belgium
| | - Sarah-Ann Aelvoet
- Laboratory for Neurobiology and Gene Therapy, Molecular Medicine, Katholieke Universiteit Leuven, 3000 Leuven, Flanders, Belgium
| | - Federica Valsecchi
- Department of Biochemistry (286), Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen Medical Centre, 6500 Nijmegen, the Netherlands
- Department of Pediatrics, Nijmegen Centre for Mitochondrial Disorders, Radboud University Nijmegen Medical Centre, 6500 Nijmegen, the Netherlands
| | - Richard J. Rodenburg
- Department of Pediatrics, Nijmegen Centre for Mitochondrial Disorders, Radboud University Nijmegen Medical Centre, 6500 Nijmegen, the Netherlands
| | - Veerle Reumers
- Laboratory for Neurobiology and Gene Therapy, Molecular Medicine, Katholieke Universiteit Leuven, 3000 Leuven, Flanders, Belgium
| | - Zeger Debyser
- Laboratory for Molecular Virology and Gene Therapy, Molecular Medicine, Katholieke Universiteit Leuven and Interdisciplinary Research Centre, Katholieke Universiteit Leuven Campus Kortrijk, 8500 Kortrijk, Flanders, Belgium
| | - Geert Callewaert
- Research Group Neurodegeneration, Interdisciplinary Research Centre, Katholieke Universiteit Leuven Campus Kortrijk, 8500 Kortrijk, Flanders, Belgium
| | - Werner J. H. Koopman
- Department of Biochemistry (286), Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen Medical Centre, 6500 Nijmegen, the Netherlands
| | - Peter H. G. M. Willems
- Department of Biochemistry (286), Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen Medical Centre, 6500 Nijmegen, the Netherlands
| | - Veerle Baekelandt
- Laboratory for Neurobiology and Gene Therapy, Molecular Medicine, Katholieke Universiteit Leuven, 3000 Leuven, Flanders, Belgium
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Koshiba T, Yasukawa K, Yanagi Y, Kawabata SI. Mitochondrial membrane potential is required for MAVS-mediated antiviral signaling. Sci Signal 2011; 4:ra7. [PMID: 21285412 DOI: 10.1126/scisignal.2001147] [Citation(s) in RCA: 191] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Mitochondria, dynamic organelles that undergo cycles of fusion and fission, are the powerhouses of eukaryotic cells and are also involved in cellular innate antiviral immunity in mammals. Mitochondrial antiviral immunity depends on activation of the cytoplasmic retinoic acid-inducible gene I (RIG-I)-like receptor (RLR) signaling pathway and the participation of a mitochondrial outer membrane adaptor protein called MAVS (mitochondrial antiviral signaling). We found that cells that lack the ability to undergo mitochondrial fusion as a result of targeted deletion of both mitofusin 1 (Mfn1) and mitofusin 2 (Mfn2) exhibited impaired induction of interferons and proinflammatory cytokines in response to viral infection, resulting in increased viral replication. In contrast, cells with null mutations in either Mfn1 or Mfn2 retained their RLR-induced antiviral responses. We also found that a reduced mitochondrial membrane potential (ΔΨ(m)) correlated with the reduced antiviral response. The dissipation in ΔΨ(m) did not affect the activation of the transcription factor interferon regulatory factor 3 downstream of MAVS, which suggests that ΔΨ(m) and MAVS are coupled at the same stage in the RLR signaling pathway. Our results provide evidence that the physiological function of mitochondria plays a key role in innate antiviral immunity.
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Affiliation(s)
- Takumi Koshiba
- 1Department of Biology, Faculty of Sciences, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan.
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42
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Koshiba T, Holman HA, Kubara K, Yasukawa K, Kawabata SI, Okamoto K, MacFarlane J, Shaw JM. Structure-function analysis of the yeast mitochondrial Rho GTPase, Gem1p: implications for mitochondrial inheritance. J Biol Chem 2011; 286:354-62. [PMID: 21036903 PMCID: PMC3012993 DOI: 10.1074/jbc.m110.180034] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2010] [Revised: 10/26/2010] [Indexed: 11/06/2022] Open
Abstract
Mitochondria undergo continuous cycles of homotypic fusion and fission, which play an important role in controlling organelle morphology, copy number, and mitochondrial DNA maintenance. Because mitochondria cannot be generated de novo, the motility and distribution of these organelles are essential for their inheritance by daughter cells during division. Mitochondrial Rho (Miro) GTPases are outer mitochondrial membrane proteins with two GTPase domains and two EF-hand motifs, which act as receptors to regulate mitochondrial motility and inheritance. Here we report that although all of these domains are biochemically active, only the GTPase domains are required for the mitochondrial inheritance function of Gem1p (the yeast Miro ortholog). Mutations in either of the Gem1p GTPase domains completely abrogated mitochondrial inheritance, although the mutant proteins retained half the GTPase activity of the wild-type protein. Although mitochondrial inheritance was not dependent upon Ca(2+) binding by the two EF-hands of Gem1p, a functional N-terminal EF-hand I motif was critical for stable expression of Gem1p in vivo. Our results suggest that basic features of Miro protein function are conserved from yeast to humans, despite differences in the cellular machinery mediating mitochondrial distribution in these organisms.
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Affiliation(s)
- Takumi Koshiba
- Department of Biology, Faculty of Sciences, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan.
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Evidence of mitochondrial dysfunction in fragile X-associated tremor/ataxia syndrome. Biochem J 2010; 429:545-52. [PMID: 20513237 DOI: 10.1042/bj20091960] [Citation(s) in RCA: 141] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
FXTAS (fragile X-associated tremor/ataxia syndrome) is a late-onset neurodegenerative disorder that affects individuals who are carriers of premutation expansions (55-200 CGG repeats) in the 5' untranslated region of the FMR1 (fragile X mental retardation 1) gene. The role of MD (mitochondrial dysfunction) in FXTAS was evaluated in fibroblasts and brain samples from premutation carriers with and without FXTAS symptoms, with a range of CGG repeats. This study resulted in several important conclusions: (i) decreased NAD- and FAD-linked oxygen uptake rates and uncoupling between electron transport and synthesis of ATP were observed in fibroblasts from premutation carriers; (ii) a lower expression of mitochondrial proteins preceded both in age and in CGG repeats the appearance of overt clinical involvement; (iii) the CGG repeat size required for altered mitochondrial protein expression was also smaller than that required to produce brain intranuclear inclusions from individuals with the premutation who died, suggesting that MD is an incipient pathological process occurring in individuals who do not display overt features of FXTAS; and (iv) on the basis of the CGG repeats, MD preceded the increase in oxidative/nitrative stress damage, indicating that the latter is a late event. MD in carriers of small CGG repeats, even when the allele size is not sufficient to produce FXTAS, may predispose them to other disorders (e.g. Parkinson's disease) that are likely to involve MD, and to environmental stressors, which may trigger the development of FXTAS symptoms. Detection of MD is of critical importance to the management of FXTAS, since it opens up additional treatment options for this disorder.
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Simmen T, Lynes EM, Gesson K, Thomas G. Oxidative protein folding in the endoplasmic reticulum: tight links to the mitochondria-associated membrane (MAM). BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2010; 1798:1465-73. [PMID: 20430008 DOI: 10.1016/j.bbamem.2010.04.009] [Citation(s) in RCA: 142] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2010] [Revised: 04/15/2010] [Accepted: 04/16/2010] [Indexed: 12/18/2022]
Abstract
The production of secretory proteins at the ER (endoplasmic reticulum) depends on a ready supply of energy and metabolites as well as the close monitoring of the chemical conditions that favor oxidative protein folding. ER oxidoreductases and chaperones fold nascent proteins into their export-competent three-dimensional structure. Interference with these protein folding enzymes leads to the accumulation of unfolded proteins within the ER lumen, causing an acute organellar stress that triggers the UPR (unfolded protein response). The UPR increases the transcription of ER chaperones commensurate with the load of newly synthesized proteins and can protect the cell from ER stress. Persistant stress, however, can force the UPR to commit cells to undergo apoptotic cell death, which requires the emptying of ER calcium stores. Conversely, a continuous ebb and flow of calcium occurs between the ER and mitochondria during resting conditions on a domain of the ER that forms close contacts with mitochondria, the MAM (mitochondria-associated membrane). On the MAM, ER folding chaperones such as calnexin and calreticulin and oxidoreductases such as ERp44, ERp57 and Ero1alpha regulate calcium flux from the ER through reversible, calcium and redox-dependent interactions with IP3Rs (inositol 1,4,5-trisphophate receptors) and with SERCAs (sarcoplasmic/endoplasmic reticulum calcium ATPases). During apoptosis progression and depending on the identity of the ER chaperone and oxidoreductase, these interactions increase or decrease, suggesting that the extent of MAM targeting of ER chaperones and oxidoreductases could shift the readout of ER-mitochondria calcium exchange from housekeeping to apoptotic. However, little is known about the cytosolic factors that mediate the on/off interactions between ER chaperones and oxidoreductases with ER calcium channels and pumps. One candidate regulator is the multi-functional molecule PACS-2 (phosphofurin acidic cluster sorting protein-2). Recent studies suggest that PACS-2 mediates localization of a mobile pool of calnexin to the MAM in addition to regulating homeostatic ER calcium signaling as well as MAM integrity. Together, these findings suggest that cytosolic, membrane and lumenal proteins combine to form a two-way switch that determines the rate of protein secretion by providing ions and metabolites and that appears to participate in the pro-apoptotic ER-mitochondria calcium transfer.
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Affiliation(s)
- Thomas Simmen
- Faculty of Medicine and Dentistry, School of Molecular and Systems Medicine, Department of Cell Biology, University of Alberta, Edmonton, Alberta, Canada.
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Griffiths EJ, Balaska D, Cheng WHY. The ups and downs of mitochondrial calcium signalling in the heart. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2010; 1797:856-64. [PMID: 20188059 DOI: 10.1016/j.bbabio.2010.02.022] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2009] [Revised: 02/18/2010] [Accepted: 02/18/2010] [Indexed: 12/17/2022]
Abstract
Regulation of intramitochondrial free calcium ([Ca2+]m) is critical in both physiological and pathological functioning of the heart. The full extent and importance of the role of [Ca2+]m is becoming apparent as evidenced by the increasing interest and work in this area over the last two decades. However, controversies remain, such as the existence of beat-to-beat mitochondrial Ca2+ transients; the role of [Ca2+]m in modulating whole-cell Ca2+ signalling; whether or not an increase in [Ca2+]m is essential to couple ATP supply and demand; and the role of [Ca2+]m in cell death by both necrosis and apoptosis, especially in formation of the mitochondrial permeability transition pore. The role of [Ca2+]m in heart failure is an area that has also recently been highlighted. [Ca2+]m can now be measured reasonably specifically in intact cells and hearts thanks to developments in fluorescent indicators and targeted proteins and more sensitive imaging technology. This has revealed interactions of the mitochondrial Ca2+ transporters with those of the sarcolemma and sarcoplasmic reticulum, and has gone a long way to bringing the mitochondrial Ca2+ transporters to the forefront of cardiac research. Mitochondrial Ca2+ uptake occurs via the ruthenium red sensitive Ca2+ uniporter (mCU), and efflux via an Na+/Ca2+ exchanger (mNCX). The purification and cloning of the transporters, and development of more specific inhibitors, would produce a step-change in our understanding of the role of these apparently critical but still elusive proteins. In this article we will summarise the key physiological roles of [Ca2+]m in ATP production and cell Ca2+ signalling in both adult and neonatal hearts, as well as highlighting some of the controversies in these areas. We will also briefly discuss recent ideas on the interactions of nitric oxide with [Ca2+]m.
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Affiliation(s)
- Elinor J Griffiths
- Department of Biochemistry and Bristol Heart Institute, University of Bristol, School of Medical Sciences, University Walk, Bristol BS8 1TD, UK.
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Abstract
Rapid to moderately rapid changes in intracellular Ca2+ concentration, or Ca2+ signals, control a variety of critical cellular functions in the immune system. These signals are comprised of Ca2+ release from intracellular stores coordinated with Ca2+ influx across the plasma membrane. The most common mechanisms by which these two modes of signaling occur is through inositol 1,4,5-trisphosphate (IP3)-induced release of Ca2+ from the endoplasmic reticulum (ER) and store-operated Ca2+ entry across the plasma membrane. The latter process was postulated over 20 years ago, and in just the past few years, the key molecular players have been discovered: STIM proteins serve as sensors of Ca2+ within the ER which communicate with and activate plasma membrane store-operated channels composed of Orai subunits. The process of store-operated Ca2+ entry provides support for oscillating Ca2+ signals from the ER and also provides direct activator Ca2+ that signals to a variety of downstream effectors.
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Affiliation(s)
- James W Putney
- Laboratory of Signal Transduction, Department of Health and Human Services, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA.
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Yasukawa K, Oshiumi H, Takeda M, Ishihara N, Yanagi Y, Seya T, Kawabata SI, Koshiba T. Mitofusin 2 inhibits mitochondrial antiviral signaling. Sci Signal 2009; 2:ra47. [PMID: 19690333 DOI: 10.1126/scisignal.2000287] [Citation(s) in RCA: 186] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The innate immune response to viral infection involves the activation of multiple signaling steps that culminate in the production of type I interferons (IFNs). Mitochondrial antiviral signaling (MAVS), a mitochondrial outer membrane adaptor protein, plays an important role in this process. Here, we report that mitofusin 2 (Mfn2), a mediator of mitochondrial fusion, interacts with MAVS to modulate antiviral immunity. Overexpression of Mfn2 resulted in the inhibition of retinoic acid-inducible gene I (RIG-I) and melanoma differentiation-associated gene 5 (MDA-5), two cytosolic sensors of viral RNA, as well as of MAVS-mediated activation of the transcription factors interferon regulatory factor 3 (IRF-3) and nuclear factor kappaB (NF-kappaB). In contrast, loss of endogenous Mfn2 enhanced virus-induced production of IFN-beta and thereby decreased viral replication. Structure-function analysis revealed that Mfn2 interacted with the carboxyl-terminal region of MAVS through a heptad repeat region, providing a structural perspective on the regulation of the mitochondrial antiviral response. Our results suggest that Mfn2 acts as an inhibitor of antiviral signaling, a function that may be distinct from its role in mitochondrial dynamics.
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Affiliation(s)
- Kai Yasukawa
- Department of Biology, Kyushu University, Hakozaki, Higashi-ku, Fukuoka, Japan
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Ruiz-Meana M, Abellán A, Miró-Casas E, Agulló E, Garcia-Dorado D. Role of sarcoplasmic reticulum in mitochondrial permeability transition and cardiomyocyte death during reperfusion. Am J Physiol Heart Circ Physiol 2009; 297:H1281-9. [PMID: 19684187 DOI: 10.1152/ajpheart.00435.2009] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
There is solid evidence that a sudden change in mitochondrial membrane permeability (mitochondrial permeability transition, MPT) plays a critical role in reperfusion-induced myocardial necrosis. We hypothesized that sarcoplasmic reticulum (SR) Ca(2+) cycling may induce partial MPT in microdomains of close anatomic proximity between mitochondria and SR, resulting in hypercontracture and cell death. MPT (mitochondrial calcein release), cell length, and sarcolemmal rupture (Trypan blue and lactate dehydrogenase release) were measured in adult rat cardiomyocytes submitted to simulated ischemia (NaCN/2-deoxyglucose, pH 6.4) and reperfusion. On simulated reperfusion, 83 +/- 2% of myocytes developed hypercontracture. In 22 +/- 6% of cases, hypercontracture was associated with sarcolemmal disruption [Trypan blue(+)]. During simulated reperfusion there was a 25% release of cyclosporin A-sensitive mitochondrial calcein (with respect to total mitochondrial calcein content). Simultaneous blockade of SR Ca(2+) uptake and release with thapsigargin and ryanodine, respectively, significantly reduced mitochondrial calcein release, hypercontracture, and cell death during simulated reperfusion. SR Ca(2+) blockers delayed mitochondrial Ca(2+) uptake in digitonin-permeabilized cardiomyocytes but did not have any effect on isolated mitochondria. Pretreatment with colchicine to disrupt microtubule network reduced the degree of fluorescent overlap between SR and mitochondria and abolished the protective effect of SR Ca(2+) blockers on MPT, hypercontracture, and cell death during reperfusion. We conclude that SR Ca(2+) cycling during reperfusion facilitates partial mitochondrial permeabilization due to the close anatomic proximity between both organelles, favoring hypercontracture and cell death.
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Affiliation(s)
- Marisol Ruiz-Meana
- Servicio de Cardiologia, Hospital Universitari Vall d'Hebron, 08035 Barcelona, Spain
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Andrade-Navarro MA, Sanchez-Pulido L, McBride HM. Mitochondrial vesicles: an ancient process providing new links to peroxisomes. Curr Opin Cell Biol 2009; 21:560-7. [DOI: 10.1016/j.ceb.2009.04.005] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2009] [Revised: 04/06/2009] [Accepted: 04/07/2009] [Indexed: 11/26/2022]
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Huang W, Xing W, Li D, Liu Y. Morphological and ultrastructural changes in tobacco BY-2 cells exposed to microcystin-RR. CHEMOSPHERE 2009; 76:1006-12. [PMID: 19501874 DOI: 10.1016/j.chemosphere.2009.03.074] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2008] [Revised: 03/03/2009] [Accepted: 03/16/2009] [Indexed: 05/27/2023]
Abstract
Tobacco BY-2 cells were exposed to microcystin-RR (MC-RR) at two concentrations, 60 microg mL(-1) and 120 microg mL(-1), to study the changes in morphology and ultrastructure of cells as a result of the exposure. Exposure to the lower concentration for 5 d led to typical apoptotic morphological changes including condensation of nuclear chromatin, creation of a characteristic 'half moon' structure, and cytoplasm shrinkage and decreased cell volume, as revealed through light microscopy, fluorescence microscopy, and transmission electron microscopy, respectively. Exposure to the higher concentration, on the other hand, led to morphological and ultrastructural changes typical of necrosis, such as rupture of the plasma membrane and the nuclear membrane and a marked swelling of cells. The presence of many vacuoles containing unusual deposits points to the involvement of vacuoles in detoxifying MC-RR. Results of the present study indicate that exposure of tobacco BY-2 cells to MC-RR at a lower concentration (60 microg mL(-1)) results in apoptosis and that to a higher concentration (120 microg mL(-1)), in necrosis.
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Affiliation(s)
- Wenmin Huang
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, The Chinese Academy of Sciences, Wuhan 430072, PR China
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