701
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Boulinguiez A, Staels B, Duez H, Lancel S. Mitochondria and endoplasmic reticulum: Targets for a better insulin sensitivity in skeletal muscle? Biochim Biophys Acta Mol Cell Biol Lipids 2017; 1862:901-916. [PMID: 28529179 DOI: 10.1016/j.bbalip.2017.05.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Revised: 05/15/2017] [Accepted: 05/17/2017] [Indexed: 12/16/2022]
Abstract
Obesity and its associated metabolic disorders represent a major health burden, with economic and social consequences. Although adapted lifestyle and bariatric surgery are effective in reducing body weight, obesity prevalence is still rising. Obese individuals often become insulin-resistant. Obesity impacts on insulin responsive organs, such as the liver, adipose tissue and skeletal muscle, and increases the risk of cardiovascular diseases, type 2 diabetes and cancer. In this review, we discuss the effects of obesity and insulin resistance on skeletal muscle, an important organ for the control of postprandial glucose. The roles of mitochondria and the endoplasmic reticulum in insulin signaling are highlighted and potential innovative research and treatment perspectives are proposed.
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Affiliation(s)
- Alexis Boulinguiez
- Univ. Lille, Inserm, CHU Lille, Institut Pasteur de Lille, U1011 - EGID, F-59000, Lille, France.
| | - Bart Staels
- Univ. Lille, Inserm, CHU Lille, Institut Pasteur de Lille, U1011 - EGID, F-59000, Lille, France.
| | - Hélène Duez
- Univ. Lille, Inserm, CHU Lille, Institut Pasteur de Lille, U1011 - EGID, F-59000, Lille, France.
| | - Steve Lancel
- Univ. Lille, Inserm, CHU Lille, Institut Pasteur de Lille, U1011 - EGID, F-59000, Lille, France.
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702
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The Interplay between Oncogenic Signaling Networks and Mitochondrial Dynamics. Antioxidants (Basel) 2017; 6:antiox6020033. [PMID: 28513539 PMCID: PMC5488013 DOI: 10.3390/antiox6020033] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2017] [Revised: 05/10/2017] [Accepted: 05/12/2017] [Indexed: 12/18/2022] Open
Abstract
Mitochondria are dynamic organelles that alter their organization in response to a variety of cellular cues. Mitochondria are central in many biologic processes, such as cellular bioenergetics and apoptosis, and mitochondrial network morphology can contribute to those physiologic processes. Some of the biologic processes that are in part governed by mitochondria are also commonly deregulated in cancers. Furthermore, patient tumor samples from a variety of cancers have revealed that mitochondrial dynamics machinery may be deregulated in tumors. In this review, we will discuss how commonly mutated oncogenes and their downstream effector pathways regulate the mitochondrial dynamics machinery to promote changes in mitochondrial morphology as well as the physiologic consequences of altered mitochondrial morphology for tumorigenic growth.
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703
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Mechanisms Underlying the Essential Role of Mitochondrial Membrane Lipids in Yeast Chronological Aging. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2017; 2017:2916985. [PMID: 28593023 PMCID: PMC5448074 DOI: 10.1155/2017/2916985] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Accepted: 04/18/2017] [Indexed: 12/12/2022]
Abstract
The functional state of mitochondria is vital to cellular and organismal aging in eukaryotes across phyla. Studies in the yeast Saccharomyces cerevisiae have provided evidence that age-related changes in some aspects of mitochondrial functionality can create certain molecular signals. These signals can then define the rate of cellular aging by altering unidirectional and bidirectional communications between mitochondria and other organelles. Several aspects of mitochondrial functionality are known to impact the replicative and/or chronological modes of yeast aging. They include mitochondrial electron transport, membrane potential, reactive oxygen species, and protein synthesis and proteostasis, as well as mitochondrial synthesis of iron-sulfur clusters, amino acids, and NADPH. Our recent findings have revealed that the composition of mitochondrial membrane lipids is one of the key aspects of mitochondrial functionality affecting yeast chronological aging. We demonstrated that exogenously added lithocholic bile acid can delay chronological aging in yeast because it elicits specific changes in mitochondrial membrane lipids. These changes allow mitochondria to operate as signaling platforms that delay yeast chronological aging by orchestrating an institution and maintenance of a distinct cellular pattern. In this review, we discuss molecular and cellular mechanisms underlying the essential role of mitochondrial membrane lipids in yeast chronological aging.
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704
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Di Benedetto G, Gerbino A, Lefkimmiatis K. Shaping mitochondrial dynamics: The role of cAMP signalling. Biochem Biophys Res Commun 2017; 500:65-74. [PMID: 28501614 DOI: 10.1016/j.bbrc.2017.05.041] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Accepted: 05/07/2017] [Indexed: 12/25/2022]
Abstract
In recent years, our idea of mitochondria evolved from "mere" energy and metabolite producers to key regulators of many cellular functions. In order to preserve and protect their functional status, these organelles engage a number of dynamic processes that allow them to decrease accumulated burden and maintain their homeostasis. Indeed, mitochondria can unite (fusion), divide (fission), position themselves strategically in the cell (motility/trafficking) and if irreversibly damaged or dysfunctional eliminated (mitophagy). These dynamic processes can be controlled both by mitochondrial and cellular signalling pathways, hence allowing mitochondria to tune their function to the cellular needs. Among the regulatory mechanisms, reversible phosphorylation downstream the cyclic AMP (cAMP) signalling cascade was shown to deeply influence mitochondrial dynamics. This review explores the emerging evidence suggesting that cAMP is a key player in the orchestration of mitochondrial fusion/fission, motility and mitophagy, extending the repertoire of this second messenger, which is now recognised as a major regulator of mitochondrial homeostasis.
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Affiliation(s)
- Giulietta Di Benedetto
- Neuroscience Institute, Italian National Research Council (CNR), Venetian Institute of Molecular Medicine, 35131, Padova, Italy
| | - Andrea Gerbino
- Department of Biosciences, Biotechnology and Biopharmaceutics, University of Bari, Bari, Italy
| | - Konstantinos Lefkimmiatis
- Neuroscience Institute, Italian National Research Council (CNR), Venetian Institute of Molecular Medicine, 35131, Padova, Italy.
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705
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Yi CX, Walter M, Gao Y, Pitra S, Legutko B, Kälin S, Layritz C, García-Cáceres C, Bielohuby M, Bidlingmaier M, Woods SC, Ghanem A, Conzelmann KK, Stern JE, Jastroch M, Tschöp MH. TNFα drives mitochondrial stress in POMC neurons in obesity. Nat Commun 2017; 8:15143. [PMID: 28489068 PMCID: PMC5436136 DOI: 10.1038/ncomms15143] [Citation(s) in RCA: 76] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Accepted: 03/03/2017] [Indexed: 12/25/2022] Open
Abstract
Consuming a calorically dense diet stimulates microglial reactivity in the mediobasal hypothalamus (MBH) in association with decreased number of appetite-curbing pro-opiomelanocortin (POMC) neurons; whether the reduction in POMC neuronal function is secondary to the microglial activation is unclear. Here we show that in hypercaloric diet-induced obese mice, persistently activated microglia in the MBH hypersecrete TNFα that in turn stimulate mitochondrial ATP production in POMC neurons, promoting mitochondrial fusion in their neurites, and increasing POMC neuronal firing rates and excitability. Specific disruption of the gene expressions of TNFα downstream signals TNFSF11A or NDUFAB1 in the MBH of diet-induced obese mice reverses mitochondrial elongation and reduces obesity. These data imply that in a hypercaloric environment, persistent elevation of microglial reactivity and consequent TNFα secretion induces mitochondrial stress in POMC neurons that contributes to the development of obesity.
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Affiliation(s)
- Chun-Xia Yi
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center at Helmholtz Zentrum München, Division of Metabolic Diseases, Department of Medicine, Technische Universität München, German Center for Diabetes Research (DZD), 85764 München-Neuherberg, Germany
- Department of Endocrinology and Metabolism, Academic Medical Center, University of Amsterdam, 1105AZ Amsterdam, The Netherlands
| | - Marc Walter
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center at Helmholtz Zentrum München, Division of Metabolic Diseases, Department of Medicine, Technische Universität München, German Center for Diabetes Research (DZD), 85764 München-Neuherberg, Germany
| | - Yuanqing Gao
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center at Helmholtz Zentrum München, Division of Metabolic Diseases, Department of Medicine, Technische Universität München, German Center for Diabetes Research (DZD), 85764 München-Neuherberg, Germany
| | - Soledad Pitra
- Department of Physiology, Augusta University, Augusta, Georgia 30912, USA
| | - Beata Legutko
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center at Helmholtz Zentrum München, Division of Metabolic Diseases, Department of Medicine, Technische Universität München, German Center for Diabetes Research (DZD), 85764 München-Neuherberg, Germany
| | - Stefanie Kälin
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center at Helmholtz Zentrum München, Division of Metabolic Diseases, Department of Medicine, Technische Universität München, German Center for Diabetes Research (DZD), 85764 München-Neuherberg, Germany
| | - Clarita Layritz
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center at Helmholtz Zentrum München, Division of Metabolic Diseases, Department of Medicine, Technische Universität München, German Center for Diabetes Research (DZD), 85764 München-Neuherberg, Germany
| | - Cristina García-Cáceres
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center at Helmholtz Zentrum München, Division of Metabolic Diseases, Department of Medicine, Technische Universität München, German Center for Diabetes Research (DZD), 85764 München-Neuherberg, Germany
| | - Maximilian Bielohuby
- Endocrine Research Unit, Klinikum der Ludwig-Maximilians-Universität, 81377 Munich, Germany
| | - Martin Bidlingmaier
- Endocrine Research Unit, Klinikum der Ludwig-Maximilians-Universität, 81377 Munich, Germany
| | - Stephen C. Woods
- Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati, Cincinnati, Ohio 45220, USA
| | - Alexander Ghanem
- Max von Pettenkofer Institute and Gene Center, Ludwig-Maximilians-Universität, 80539 Munich, Germany
| | - Karl-Klaus Conzelmann
- Max von Pettenkofer Institute and Gene Center, Ludwig-Maximilians-Universität, 80539 Munich, Germany
| | - Javier E. Stern
- Department of Physiology, Augusta University, Augusta, Georgia 30912, USA
| | - Martin Jastroch
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center at Helmholtz Zentrum München, Division of Metabolic Diseases, Department of Medicine, Technische Universität München, German Center for Diabetes Research (DZD), 85764 München-Neuherberg, Germany
| | - Matthias H. Tschöp
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center at Helmholtz Zentrum München, Division of Metabolic Diseases, Department of Medicine, Technische Universität München, German Center for Diabetes Research (DZD), 85764 München-Neuherberg, Germany
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706
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Kabra UD, Pfuhlmann K, Migliorini A, Keipert S, Lamp D, Korsgren O, Gegg M, Woods SC, Pfluger PT, Lickert H, Affourtit C, Tschöp MH, Jastroch M. Direct Substrate Delivery Into Mitochondrial Fission-Deficient Pancreatic Islets Rescues Insulin Secretion. Diabetes 2017; 66:1247-1257. [PMID: 28174288 DOI: 10.2337/db16-1088] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Accepted: 01/29/2017] [Indexed: 11/13/2022]
Abstract
In pancreatic β-cells, mitochondrial bioenergetics control glucose-stimulated insulin secretion. Mitochondrial dynamics are generally associated with quality control, maintaining the functionality of bioenergetics. By acute pharmacological inhibition of mitochondrial fission protein Drp1, we demonstrate in this study that mitochondrial fission is necessary for glucose-stimulated insulin secretion in mouse and human islets. We confirm that genetic silencing of Drp1 increases mitochondrial proton leak in MIN6 cells. However, our comprehensive analysis of pancreatic islet bioenergetics reveals that Drp1 does not control insulin secretion via its effect on proton leak but instead via modulation of glucose-fueled respiration. Notably, pyruvate fully rescues the impaired insulin secretion of fission-deficient β-cells, demonstrating that defective mitochondrial dynamics solely affect substrate supply upstream of oxidative phosphorylation. The present findings provide novel insights into how mitochondrial dysfunction may cause pancreatic β-cell failure. In addition, the results will stimulate new thinking in the intersecting fields of mitochondrial dynamics and bioenergetics, as treatment of defective dynamics in mitochondrial diseases appears to be possible by improving metabolism upstream of mitochondria.
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Affiliation(s)
- Uma D Kabra
- Helmholtz Diabetes Center, Helmholtz Zentrum München, Neuherberg, Germany
- German Center for Diabetes Research, Helmholtz Zentrum München, Neuherberg, Germany
- Division of Metabolic Diseases, Technische Universität München, Munich, Germany
| | - Katrin Pfuhlmann
- Helmholtz Diabetes Center, Helmholtz Zentrum München, Neuherberg, Germany
- German Center for Diabetes Research, Helmholtz Zentrum München, Neuherberg, Germany
- Division of Metabolic Diseases, Technische Universität München, Munich, Germany
| | - Adriana Migliorini
- Helmholtz Diabetes Center, Helmholtz Zentrum München, Neuherberg, Germany
- German Center for Diabetes Research, Helmholtz Zentrum München, Neuherberg, Germany
| | - Susanne Keipert
- Helmholtz Diabetes Center, Helmholtz Zentrum München, Neuherberg, Germany
- German Center for Diabetes Research, Helmholtz Zentrum München, Neuherberg, Germany
| | - Daniel Lamp
- Helmholtz Diabetes Center, Helmholtz Zentrum München, Neuherberg, Germany
- German Center for Diabetes Research, Helmholtz Zentrum München, Neuherberg, Germany
- Division of Metabolic Diseases, Technische Universität München, Munich, Germany
| | - Olle Korsgren
- Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
| | - Moritz Gegg
- Helmholtz Diabetes Center, Helmholtz Zentrum München, Neuherberg, Germany
- German Center for Diabetes Research, Helmholtz Zentrum München, Neuherberg, Germany
- Division of Metabolic Diseases, Technische Universität München, Munich, Germany
| | - Stephen C Woods
- Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati, Cincinnati, OH
| | - Paul T Pfluger
- Helmholtz Diabetes Center, Helmholtz Zentrum München, Neuherberg, Germany
- German Center for Diabetes Research, Helmholtz Zentrum München, Neuherberg, Germany
| | - Heiko Lickert
- Helmholtz Diabetes Center, Helmholtz Zentrum München, Neuherberg, Germany
- German Center for Diabetes Research, Helmholtz Zentrum München, Neuherberg, Germany
- Division of Metabolic Diseases, Technische Universität München, Munich, Germany
| | - Charles Affourtit
- School of Biomedical and Healthcare Sciences, Plymouth University, Plymouth, U.K
| | - Matthias H Tschöp
- Helmholtz Diabetes Center, Helmholtz Zentrum München, Neuherberg, Germany
- German Center for Diabetes Research, Helmholtz Zentrum München, Neuherberg, Germany
- Division of Metabolic Diseases, Technische Universität München, Munich, Germany
| | - Martin Jastroch
- Helmholtz Diabetes Center, Helmholtz Zentrum München, Neuherberg, Germany
- German Center for Diabetes Research, Helmholtz Zentrum München, Neuherberg, Germany
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707
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Li J, Huang Q, Long X, Guo X, Sun X, Jin X, Li Z, Ren T, Yuan P, Huang X, Zhang H, Xing J. Mitochondrial elongation-mediated glucose metabolism reprogramming is essential for tumour cell survival during energy stress. Oncogene 2017; 36:4901-4912. [DOI: 10.1038/onc.2017.98] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Revised: 03/01/2017] [Accepted: 03/03/2017] [Indexed: 12/14/2022]
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708
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Chao T, Wang H, Ho PC. Mitochondrial Control and Guidance of Cellular Activities of T Cells. Front Immunol 2017; 8:473. [PMID: 28484465 PMCID: PMC5401871 DOI: 10.3389/fimmu.2017.00473] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2016] [Accepted: 04/05/2017] [Indexed: 01/01/2023] Open
Abstract
Immune cells protect us against infection and cancer cells, as well as functioning during healing processes to support tissue repairing and regeneration. These behaviors require that upon stimulation from immune activation the appropriate subsets of immune cells are generated. In addition to activation-induced signaling cascades, metabolic reprogramming (profound changes in metabolic pathways) also provides a novel form of regulation to control the formation of desirable immune responses. Immune cells encounter various nutrient compositions by circulating in bloodstream and infiltrating into peripheral tissues; therefore, proper engagement of metabolic pathways is critical to fulfill the metabolic demands of immune cells. Metabolic pathways are tightly regulated mainly via mitochondrial dynamics and the activities of the tricarboxylic acid cycle and the electron transport chain. In this review, we will discuss how metabolic reprogramming influences activation, effector functions, and lineage polarization in T cells, with a particular focus on mitochondria-regulated metabolic checkpoints. Additionally, we will further explore how in various diseases deregulation and manipulation of mitochondrial regulation can occur and be exploited. Furthermore, we will discuss how this knowledge can facilitate the design of immunotherapies.
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Affiliation(s)
- Tung Chao
- Department of Fundamental Oncology, University of Lausanne, Lausanne, Switzerland.,Ludwig Center for Cancer Research, University of Lausanne, Lausanne, Switzerland
| | - Haiping Wang
- Department of Fundamental Oncology, University of Lausanne, Lausanne, Switzerland.,Ludwig Center for Cancer Research, University of Lausanne, Lausanne, Switzerland
| | - Ping-Chih Ho
- Department of Fundamental Oncology, University of Lausanne, Lausanne, Switzerland.,Ludwig Center for Cancer Research, University of Lausanne, Lausanne, Switzerland
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709
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Rocha N, Bulger DA, Frontini A, Titheradge H, Gribsholt SB, Knox R, Page M, Harris J, Payne F, Adams C, Sleigh A, Crawford J, Gjesing AP, Bork-Jensen J, Pedersen O, Barroso I, Hansen T, Cox H, Reilly M, Rossor A, Brown RJ, Taylor SI, McHale D, Armstrong M, Oral EA, Saudek V, O'Rahilly S, Maher ER, Richelsen B, Savage DB, Semple RK. Human biallelic MFN2 mutations induce mitochondrial dysfunction, upper body adipose hyperplasia, and suppression of leptin expression. eLife 2017; 6:e23813. [PMID: 28414270 PMCID: PMC5422073 DOI: 10.7554/elife.23813] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Accepted: 04/11/2017] [Indexed: 12/25/2022] Open
Abstract
MFN2 encodes mitofusin 2, a membrane-bound mediator of mitochondrial membrane fusion and inter-organelle communication. MFN2 mutations cause axonal neuropathy, with associated lipodystrophy only occasionally noted, however homozygosity for the p.Arg707Trp mutation was recently associated with upper body adipose overgrowth. We describe similar massive adipose overgrowth with suppressed leptin expression in four further patients with biallelic MFN2 mutations and at least one p.Arg707Trp allele. Overgrown tissue was composed of normal-sized, UCP1-negative unilocular adipocytes, with mitochondrial network fragmentation, disorganised cristae, and increased autophagosomes. There was strong transcriptional evidence of mitochondrial stress signalling, increased protein synthesis, and suppression of signatures of cell death in affected tissue, whereas mitochondrial morphology and gene expression were normal in skin fibroblasts. These findings suggest that specific MFN2 mutations cause tissue-selective mitochondrial dysfunction with increased adipocyte proliferation and survival, confirm a novel form of excess adiposity with paradoxical suppression of leptin expression, and suggest potential targeted therapies.
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Affiliation(s)
- Nuno Rocha
- The University of Cambridge Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Cambridge, United Kingdom
- The National Institute for Health Research Cambridge Biomedical Research Centre, Cambridge, United Kingdom
| | - David A Bulger
- The University of Cambridge Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Cambridge, United Kingdom
- The National Institute for Health Research Cambridge Biomedical Research Centre, Cambridge, United Kingdom
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, United States
| | - Andrea Frontini
- Department of Public Health, Experimental and Forensic Medicine, University of Pavia, Pavia, Italy
| | - Hannah Titheradge
- Institute of Cancer and Genomic Sciences, University of Birmingham, Birmingham, United Kingdom
- West Midlands Medical Genetics Department, Birmingham Women's Hospital, Edgbaston, Birmingham, United Kingdom
| | - Sigrid Bjerge Gribsholt
- Department of Endocrinology and Internal Medicine and Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus, Denmark
| | - Rachel Knox
- The University of Cambridge Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Cambridge, United Kingdom
- The National Institute for Health Research Cambridge Biomedical Research Centre, Cambridge, United Kingdom
| | - Matthew Page
- New Medicines, UCB Pharma, Slough, United Kingdom
| | - Julie Harris
- The University of Cambridge Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Cambridge, United Kingdom
- The National Institute for Health Research Cambridge Biomedical Research Centre, Cambridge, United Kingdom
| | - Felicity Payne
- Wellcome Trust Sanger Institute, Cambridge, United Kingdom
| | - Claire Adams
- The University of Cambridge Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Cambridge, United Kingdom
- The National Institute for Health Research Cambridge Biomedical Research Centre, Cambridge, United Kingdom
| | - Alison Sleigh
- Wolfson Brain Imaging Centre, University of Cambridge School of Clinical Medicine, Cambridge Biomedical Campus, Cambridge, United Kingdom
- National Institute for Health Research/Wellcome Trust Clinical Research Facility, Cambridge University Hospitals NHS Foundation Trust, Cambridge Biomedical Campus, Cambridge, United Kingdom
| | - John Crawford
- Cambridge University Hospitals NHS Foundation Trust, Cambridge Biomedical Campus, Cambridge, United Kingdom
| | - Anette Prior Gjesing
- The Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jette Bork-Jensen
- The Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Oluf Pedersen
- The Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Inês Barroso
- Wellcome Trust Sanger Institute, Cambridge, United Kingdom
| | - Torben Hansen
- The Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Helen Cox
- West Midlands Medical Genetics Department, Birmingham Women's Hospital, Edgbaston, Birmingham, United Kingdom
| | - Mary Reilly
- MRC Centre for Neuromuscular Diseases, National Hospital for Neurology and Neurosurgery, UCL Institute of Neurology, London, United Kingdom
| | - Alex Rossor
- MRC Centre for Neuromuscular Diseases, National Hospital for Neurology and Neurosurgery, UCL Institute of Neurology, London, United Kingdom
| | - Rebecca J Brown
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, United States
| | - Simeon I Taylor
- University of Maryland School of Medicine, Baltimore, United States
| | | | | | - Elif A Oral
- Metabolism, Endocrinology and Diabetes (MEND) Division, Department of Internal of Medicine, Brehm Center for Diabetes, Ann Arbor, United States
| | - Vladimir Saudek
- The University of Cambridge Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Cambridge, United Kingdom
- The National Institute for Health Research Cambridge Biomedical Research Centre, Cambridge, United Kingdom
| | - Stephen O'Rahilly
- The University of Cambridge Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Cambridge, United Kingdom
- The National Institute for Health Research Cambridge Biomedical Research Centre, Cambridge, United Kingdom
| | - Eamonn R Maher
- The National Institute for Health Research Cambridge Biomedical Research Centre, Cambridge, United Kingdom
- Department of Medical Genetics, University of Cambridge School of Clinical Medicine, Cambridge, United Kingdom
| | - Bjørn Richelsen
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital and Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - David B Savage
- The University of Cambridge Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Cambridge, United Kingdom
- The National Institute for Health Research Cambridge Biomedical Research Centre, Cambridge, United Kingdom
| | - Robert K Semple
- The University of Cambridge Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Cambridge, United Kingdom
- The National Institute for Health Research Cambridge Biomedical Research Centre, Cambridge, United Kingdom
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710
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Chen MH, Wang FX, Cao JJ, Tan CP, Ji LN, Mao ZW. Light-Up Mitophagy in Live Cells with Dual-Functional Theranostic Phosphorescent Iridium(III) Complexes. ACS APPLIED MATERIALS & INTERFACES 2017; 9:13304-13314. [PMID: 28345337 DOI: 10.1021/acsami.7b01735] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Phosphorescent Ir(III) complexes are expected to be new multifunctional theranostic platforms that enable the integration of imaging capabilities and anticancer properties. Mitophagy is an important selective autophagic process that degrades dysfunctional mitochondria. Until now, the regulation of mitophagy is still poorly understood. Herein, we present two phosphorescent cyclometalated iridium(III) complexes (Ir1 and Ir2) that can accumulate in mitochondria and induce mitophagy. Because of their intrinsic phosphorescence, they can specially image mitochondria and track mitochondrial morphological alterations. Mechanism studies show that Ir1 and Ir2 induce mitophagy by depolarization of mitochondrial membrane potential, depletion of cellular ATP, perturbation in mitochondrial metabolic status, and induction of oxidative stress. Moreover, no sign of apoptosis is observed in Ir1- and Ir2-treated cells under the same conditions that an obvious mitophagic response is initiated. We demonstrate that Ir1 is a promising theranostic agent that can induce mitophagy and visualize changes in mitochondrial morphology simultaneously.
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Affiliation(s)
- Mu-He Chen
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry, Sun Yat-Sen University , Guangzhou 510275, P. R. China
| | - Fang-Xin Wang
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry, Sun Yat-Sen University , Guangzhou 510275, P. R. China
| | - Jian-Jun Cao
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry, Sun Yat-Sen University , Guangzhou 510275, P. R. China
| | - Cai-Ping Tan
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry, Sun Yat-Sen University , Guangzhou 510275, P. R. China
| | - Liang-Nian Ji
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry, Sun Yat-Sen University , Guangzhou 510275, P. R. China
| | - Zong-Wan Mao
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry, Sun Yat-Sen University , Guangzhou 510275, P. R. China
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711
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Mitochondrial Dynamics: In Cell Reprogramming as It Is in Cancer. Stem Cells Int 2017; 2017:8073721. [PMID: 28484497 PMCID: PMC5412136 DOI: 10.1155/2017/8073721] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2017] [Accepted: 03/19/2017] [Indexed: 12/29/2022] Open
Abstract
Somatic cells can be reprogrammed into a pluripotent cellular state similar to that of embryonic stem cells. Given the significant physiological differences between the somatic and pluripotent cells, cell reprogramming is associated with a profound reorganization of the somatic phenotype at all levels. The remodeling of mitochondrial morphology is one of these dramatic changes that somatic cells have to undertake during cell reprogramming. Somatic cells transform their tubular and interconnected mitochondrial network to the fragmented and isolated organelles found in pluripotent stem cells early during cell reprogramming. Accordingly, mitochondrial fission, the process whereby the mitochondria divide, plays an important role in the cell reprogramming process. Here, we present an overview of the importance of mitochondrial fission in both cell reprogramming and cellular transformation.
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712
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Zhang L, Gan X, He Y, Zhu Z, Zhu J, Yu H. Drp1-dependent mitochondrial fission mediates osteogenic dysfunction in inflammation through elevated production of reactive oxygen species. PLoS One 2017; 12:e0175262. [PMID: 28388678 PMCID: PMC5384744 DOI: 10.1371/journal.pone.0175262] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Accepted: 03/23/2017] [Indexed: 02/05/2023] Open
Abstract
Although previous studies have implicated pro-inflammatory cytokines, such as tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6), to be detrimental for osteogenic activity, the related regulatory mechanisms are not yet fully validated. Since mitochondria host several essential metabolic processes and play a pivotal role in cellular functions, whether and how mitochondrial function contributes to inflammation-induced bone destruction needs further exploration. Our findings revealed that TNF-α impaired osteoblast function, including decreased mRNA levels of osteogenic markers, suppressed ALP expression and activity, and compromised cellular viability. Moreover, increased reactive oxygen species (ROS)-mediated oxidative stress in the TNF-α-treated group enhanced excessive mitochondrial fragmentation and disrupted mitochondrial function. However, treatment with antioxidant N-acetyl cysteine (NAC) or mitochondrial division inhibitor Mdivi-1 protected the cells from these adverse phenomena. These findings provide new insights into the role of the Drp1-dependent mitochondrial pathway in the osteogenic dysfunction during inflammation, indicating that this pathway may be a target for the development of new therapeutic approaches for the prevention and treatment of inflammation-induced bone destruction.
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Affiliation(s)
- Ling Zhang
- State Key Laboratory of Oral Disease, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Xueqi Gan
- State Key Laboratory of Oral Disease, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Yuting He
- State Key Laboratory of Oral Disease, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Zhuoli Zhu
- State Key Laboratory of Oral Disease, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Junfei Zhu
- State Key Laboratory of Oral Disease, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Haiyang Yu
- State Key Laboratory of Oral Disease, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
- * E-mail:
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713
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Jones E, Gaytan N, Garcia I, Herrera A, Ramos M, Agarwala D, Rana M, Innis-Whitehouse W, Schuenzel E, Gilkerson R. A threshold of transmembrane potential is required for mitochondrial dynamic balance mediated by DRP1 and OMA1. Cell Mol Life Sci 2017; 74:1347-1363. [PMID: 27858084 PMCID: PMC5346411 DOI: 10.1007/s00018-016-2421-9] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Revised: 11/06/2016] [Accepted: 11/14/2016] [Indexed: 12/22/2022]
Abstract
As an organellar network, mitochondria dynamically regulate their organization via opposing fusion and fission pathways to maintain bioenergetic homeostasis and contribute to key cellular pathways. This dynamic balance is directly linked to bioenergetic function: loss of transmembrane potential across the inner membrane (Δψ m) disrupts mitochondrial fission/fusion balance, causing fragmentation of the network. However, the level of Δψ m required for mitochondrial dynamic balance, as well as the relative contributions of fission and fusion pathways, have remained unclear. To explore this, mitochondrial morphology and Δψ m were examined via confocal imaging and tetramethyl rhodamine ester (TMRE) flow cytometry, respectively, in cultured 143B osteosarcoma cells. When normalized to the TMRE value of untreated 143B cells as 100%, both genetic (mtDNA-depleted ρ0) and pharmacological [carbonyl cyanide m-chlorophenyl hydrazone (CCCP)-treated] cell models below 34% TMRE fluorescence were unable to maintain mitochondrial interconnection, correlating with loss of fusion-active long OPA1 isoforms (L-OPA1). Mechanistically, this threshold is maintained by mechanistic coordination of DRP1-mediated fission and OPA1-mediated fusion: cells lacking either DRP1 or the OMA1 metalloprotease were insensitive to loss of Δψ m, instead maintaining an obligately fused morphology. Collectively, these findings demonstrate a mitochondrial 'tipping point' threshold mediated by the interaction of Δψ m with both DRP1 and OMA1; moreover, DRP1 appears to be required for effective OPA1 maintenance and processing, consistent with growing evidence for direct interaction of fission and fusion pathways. These results suggest that Δψ m below threshold coordinately activates both DRP1-mediated fission and OMA1 cleavage of OPA1, collapsing mitochondrial dynamic balance, with major implications for a range of signaling pathways and cellular life/death events.
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Affiliation(s)
- Edith Jones
- Department of Biology, The University of Texas Rio Grande Valley, 1201 West University Drive, Edinburg, TX, 78539-2999, USA
| | - Norma Gaytan
- Department of Biology, The University of Texas Rio Grande Valley, 1201 West University Drive, Edinburg, TX, 78539-2999, USA
| | - Iraselia Garcia
- Department of Biology, The University of Texas Rio Grande Valley, 1201 West University Drive, Edinburg, TX, 78539-2999, USA
| | - Alan Herrera
- Department of Biology, The University of Texas Rio Grande Valley, 1201 West University Drive, Edinburg, TX, 78539-2999, USA
| | - Manuel Ramos
- Department of Biology, The University of Texas Rio Grande Valley, 1201 West University Drive, Edinburg, TX, 78539-2999, USA
| | - Divya Agarwala
- Department of Biology, The University of Texas Rio Grande Valley, 1201 West University Drive, Edinburg, TX, 78539-2999, USA
| | - Maahrose Rana
- Department of Biology, The University of Texas Rio Grande Valley, 1201 West University Drive, Edinburg, TX, 78539-2999, USA
| | - Wendy Innis-Whitehouse
- Department of Biomedical Sciences, The University of Texas Rio Grande Valley, Edinburg, TX, 78539-2999, USA
| | - Erin Schuenzel
- Department of Biology, The University of Texas Rio Grande Valley, 1201 West University Drive, Edinburg, TX, 78539-2999, USA
| | - Robert Gilkerson
- Department of Biology, The University of Texas Rio Grande Valley, 1201 West University Drive, Edinburg, TX, 78539-2999, USA.
- Department of Clinical Laboratory Sciences, The University of Texas Rio Grande Valley, 1201 West University Drive, Edinburg, TX, 78539-2999, USA.
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714
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715
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Yang X, Wang H, Ni HM, Xiong A, Wang Z, Sesaki H, Ding WX, Yang L. Inhibition of Drp1 protects against senecionine-induced mitochondria-mediated apoptosis in primary hepatocytes and in mice. Redox Biol 2017; 12:264-273. [PMID: 28282614 PMCID: PMC5344326 DOI: 10.1016/j.redox.2017.02.020] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Revised: 02/12/2017] [Accepted: 02/24/2017] [Indexed: 02/01/2023] Open
Abstract
Pyrrolizidine alkaloids (PAs) are a group of compounds found in various plants and some of them are widely consumed in the world as herbal medicines and food supplements. PAs are potent hepatotoxins that cause irreversible liver injury in animals and humans. However, the mechanisms by which PAs induce liver injury are not clear. In the present study, we determined the hepatotoxicity and molecular mechanisms of senecionine, one of the most common toxic PAs, in primary cultured mouse and human hepatocytes as well as in mice. We found that senecionine administration increased serum alanine aminotransferase levels in mice. H&E and TUNEL staining of liver tissues revealed increased hemorrhage and hepatocyte apoptosis in liver zone 2 areas. Mechanistically, senecionine induced loss of mitochondrial membrane potential, release of mitochondrial cytochrome c as well as mitochondrial JNK translocation and activation prior to the increased DNA fragmentation and caspase-3 activation in primary cultured mouse and human hepatocytes. SP600125, a specific JNK inhibitor, and ZVAD-fmk, a general caspase inhibitor, alleviated senecionine-induced apoptosis in primary hepatocytes. Interestingly, senecionine also caused marked mitochondria fragmentation in hepatocytes. Pharmacological inhibition of dynamin-related protein1 (Drp1), a protein that is critical to regulate mitochondrial fission, blocked senecionine-induced mitochondrial fragmentation and mitochondrial release of cytochrome c and apoptosis. More importantly, hepatocyte-specific Drp1 knockout mice were resistant to senecionine-induced liver injury due to decreased mitochondrial damage and apoptosis. In conclusion, our results uncovered a novel mechanism of Drp1-mediated mitochondrial fragmentation in senecionine-induced liver injury. Targeting Drp1-mediated mitochondrial fragmentation and apoptosis may be a potential avenue to prevent and treat hepatotoxicity induced by PAs. Senecionine induces apoptosis in primary mouse and human hepatocytes as well as in mouse livers. Senecionine induces mitochondrial Drp1 translocation, mitochondrial fragmentation, loss of mitochondrial membrane potential and release of mitochondrial cytochrome c in hepatocytes. Pharmacological inhibition or genetic deletion of Drp1 protects against senecionine-induced hepatotoxicity. Targeting Drp1-mediated mitochondrial fragmentation and apoptosis may be a potential avenue to prevent and treat hepatotoxicity induced by Pyrrolizidine alkaloids.
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Affiliation(s)
- Xiao Yang
- The Key Laboratory of Standardization of Chinese Medicines of Ministry of Education, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai 2001203, China; Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas 66160, USA
| | - Hua Wang
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas 66160, USA
| | - Hong-Min Ni
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas 66160, USA
| | - Aizhen Xiong
- The Key Laboratory of Standardization of Chinese Medicines of Ministry of Education, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai 2001203, China
| | - Zhengtao Wang
- The Key Laboratory of Standardization of Chinese Medicines of Ministry of Education, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai 2001203, China
| | - Hiromi Sesaki
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD 21205
| | - Wen-Xing Ding
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas 66160, USA.
| | - Li Yang
- The Key Laboratory of Standardization of Chinese Medicines of Ministry of Education, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai 2001203, China; Center for Chinese Medical Therapy and Systems Biology, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China.
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716
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Filippi BM, Abraham MA, Silva PN, Rasti M, LaPierre MP, Bauer PV, Rocheleau JV, Lam TK. Dynamin-Related Protein 1-Dependent Mitochondrial Fission Changes in the Dorsal Vagal Complex Regulate Insulin Action. Cell Rep 2017; 18:2301-2309. [DOI: 10.1016/j.celrep.2017.02.035] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Revised: 01/26/2017] [Accepted: 02/11/2017] [Indexed: 11/25/2022] Open
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717
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Coutinho E, Batista C, Sousa F, Queiroz J, Costa D. Mitochondrial Gene Therapy: Advances in Mitochondrial Gene Cloning, Plasmid Production, and Nanosystems Targeted to Mitochondria. Mol Pharm 2017; 14:626-638. [PMID: 28199112 DOI: 10.1021/acs.molpharmaceut.6b00823] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Mitochondrial gene therapy seems to be a valuable and promising strategy to treat mitochondrial disorders. The use of a therapeutic vector based on mitochondrial DNA, along with its affinity to the site of mitochondria, can be considered a powerful tool in the reestablishment of normal mitochondrial function. In line with this and for the first time, we successfully cloned the mitochondrial gene ND1 that was stably maintained in multicopy pCAG-GFP plasmid, which is used to transform E. coli. This mitochondrial-gene-based plasmid was encapsulated into nanoparticles. Furthermore, the functionalization of nanoparticles with polymers, such as cellulose or gelatin, enhances their overall properties and performance for gene therapy. The fluorescence arising from rhodamine nanoparticles in mitochondria and a fluorescence microscopy study show pCAG-GFP-ND1-based nanoparticles' cell internalization and mitochondria targeting. The quantification of GFP expression strongly supports this finding. This work highlights the viability of gene therapy based on mitochondrial DNA instigating further in vitro research and clinical translation.
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Affiliation(s)
- Eduarda Coutinho
- CICS-UBI-Health Sciences Research Centre, University of Beira Interior , Av. Infante D. Henrique, 6200-506 Covilhã, Portugal
| | - Cátia Batista
- CICS-UBI-Health Sciences Research Centre, University of Beira Interior , Av. Infante D. Henrique, 6200-506 Covilhã, Portugal
| | - Fani Sousa
- CICS-UBI-Health Sciences Research Centre, University of Beira Interior , Av. Infante D. Henrique, 6200-506 Covilhã, Portugal
| | - João Queiroz
- CICS-UBI-Health Sciences Research Centre, University of Beira Interior , Av. Infante D. Henrique, 6200-506 Covilhã, Portugal
| | - Diana Costa
- CICS-UBI-Health Sciences Research Centre, University of Beira Interior , Av. Infante D. Henrique, 6200-506 Covilhã, Portugal
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718
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Mitochondrial Dysregulation Secondary to Endoplasmic Reticulum Stress in Autosomal Dominant Tubulointerstitial Kidney Disease - UMOD (ADTKD-UMOD). Sci Rep 2017; 7:42970. [PMID: 28220896 PMCID: PMC5318959 DOI: 10.1038/srep42970] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Accepted: 01/17/2017] [Indexed: 02/07/2023] Open
Abstract
‘Autosomal dominant tubulointerstitial kidney disease – UMOD’ (ADTKD-UMOD) is caused by impaired maturation and secretion of mutant uromodulin (UMOD) in thick ascending limb of Henle loop (TAL) cells, resulting in endoplasmic reticulum (ER) stress and unfolded protein response (UPR). To gain insight into pathophysiology, we analysed proteome profiles of TAL-enriched outer renal medulla samples from ADTKD-UMOD and control mice by quantitative LC-MS/MS. In total, 212 differentially abundant proteins were identified. Numerous ER proteins, including BiP (HSPA5), phosphorylated eIF2α (EIF2S1), ATF4, ATF6 and CHOP (DDIT3), were increased abundant, consistent with UPR. The abundance of hypoxia-inducible proteins with stress survival functions, i.e. HYOU1, TXNDC5 and ERO1L, was also increased. TAL cells in ADTKD-UMOD showed a decreased proportion of mitochondria and reduced abundance of multiple mitochondrial proteins, associated with disturbed post-translational processing and activation of the mitochondrial transcription factor NRF1. Impaired fission of organelles, as suggested by reduced abundance of FIS1, may be another reason for disturbed biogenesis of mitochondria and peroxisomes. Reduced amounts of numerous proteins of the OXPHOS and citrate cycle pathways, and activation of the LKB1-AMPK-pathway, a sensor pathway of cellular energy deficits, suggest impaired energy homeostasis. In conclusion, our study revealed secondary mitochondrial dysfunction in ADTKD-UMOD.
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719
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Ding M, Dong Q, Liu Z, Liu Z, Qu Y, Li X, Huo C, Jia X, Fu F, Wang X. Inhibition of dynamin-related protein 1 protects against myocardial ischemia-reperfusion injury in diabetic mice. Cardiovasc Diabetol 2017; 16:19. [PMID: 28173848 PMCID: PMC5297196 DOI: 10.1186/s12933-017-0501-2] [Citation(s) in RCA: 82] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2016] [Accepted: 01/31/2017] [Indexed: 01/05/2023] Open
Abstract
Background Many cardioprotective pharmacological agents failed to exert their protective effects in diabetic hearts subjected to myocardial ischemia/reperfusion (MI/R). Identify the molecular basis linking diabetes with MI/R injury is scientifically important and may provide effective therapeutic approaches. Dynamin-related protein 1 (Drp1)-mediated mitochondrial fission plays an important role in MI/R injury under non-diabetic conditions. Importantly, recent studies indicated that Drp1-mediated mitochondrial fission is enhanced in the myocardium of diabetic mice. The above evidences suggested that Drp1 may be one critical molecule linking diabetes with MI/R injury. We hypothesized that inhibition of Drp1 may be effective to reduce MI/R injury in diabetic hearts. Methods High-fat diet and streptozotocin-induced diabetic mice were subjected to MI/R or sham operation. Mdivi-1 (1.2 mg/kg), a small molecule inhibitor of Drp1 or vehicle was administrated 15 min before the onset of reperfusion. Outcome measures included mitochondrial morphology, mitochondrial function, myocardial injury, cardiac function and oxidative stress. Results Mitochondrial fission was significantly increased following MI/R as evidenced by enhanced translocation of Drp1 to mitochondria and decreased mitochondrial size. Delivery of Mdivi-1 into diabetic mice markedly inhibited Drp1 translocation to the mitochondria and reduced mitochondrial fission following MI/R. Inhibition of Drp1 in diabetic hearts improved mitochondrial function and cardiac function following MI/R. Moreover, inhibition of Drp1 reduced myocardial infarct size and serum cardiac troponin I and lactate dehydrogenase activities. These cardioprotective effects were associated with decreased cardiomyocyte apoptosis and malondialdehyde production and increased activities of antioxidant enzyme manganese superoxide dismutase. Conclusions Pharmacological inhibition of Drp1 prevents mitochondrial fission and reduces MI/R injury in diabetic mice. The findings suggest Drp1 may be a potential novel therapeutic target for diabetic cardiac complications.
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Affiliation(s)
- Mingge Ding
- Department of Geriatrics, Xi'an Central Hospital, Xi'an, 710003, China.,Department of Geriatrics, Xijing Hospital, Fourth Military Medical University, 15 Changlexi Road, Xi'an, 710032, China
| | - Qianqian Dong
- Department of Natural Medicine, School of Pharmacy, Fourth Military Medical University, Xi'an, 710032, China
| | - Zhenghua Liu
- Department of Physiology, Fourth Military Medical University, 169 Changlexi Road, Xi'an, 710032, China
| | - Zheng Liu
- Department of Physiology, Fourth Military Medical University, 169 Changlexi Road, Xi'an, 710032, China
| | - Yinxian Qu
- Department of Geriatrics, Xi'an Central Hospital, Xi'an, 710003, China
| | - Xing Li
- Department of Geriatrics, Xijing Hospital, Fourth Military Medical University, 15 Changlexi Road, Xi'an, 710032, China
| | - Cong Huo
- Department of Geriatrics, Xijing Hospital, Fourth Military Medical University, 15 Changlexi Road, Xi'an, 710032, China
| | - Xin Jia
- Department of Geriatrics, Xijing Hospital, Fourth Military Medical University, 15 Changlexi Road, Xi'an, 710032, China
| | - Feng Fu
- Department of Physiology, Fourth Military Medical University, 169 Changlexi Road, Xi'an, 710032, China.
| | - Xiaoming Wang
- Department of Geriatrics, Xijing Hospital, Fourth Military Medical University, 15 Changlexi Road, Xi'an, 710032, China.
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720
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Flippo KH, Strack S. Mitochondrial dynamics in neuronal injury, development and plasticity. J Cell Sci 2017; 130:671-681. [PMID: 28154157 DOI: 10.1242/jcs.171017] [Citation(s) in RCA: 156] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Mitochondria fulfill numerous cellular functions including ATP production, Ca2+ buffering, neurotransmitter synthesis and degradation, ROS production and sequestration, apoptosis and intermediate metabolism. Mitochondrial dynamics, a collective term for the processes of mitochondrial fission, fusion and transport, governs mitochondrial function and localization within the cell. Correct balance of mitochondrial dynamics is especially important in neurons as mutations in fission and fusion enzymes cause peripheral neuropathies and impaired development of the nervous system in humans. Regulation of mitochondrial dynamics is partly accomplished through post-translational modification of mitochondrial fission and fusion enzymes, in turn influencing mitochondrial bioenergetics and transport. The importance of post-translational regulation is highlighted by numerous neurodegenerative disorders associated with post-translational modification of the mitochondrial fission enzyme Drp1. Not surprisingly, mitochondrial dynamics also play an important physiological role in the development of the nervous system and synaptic plasticity. Here, we highlight recent findings underlying the mechanisms and regulation of mitochondrial dynamics in relation to neurological disease, as well as the development and plasticity of the nervous system.
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Affiliation(s)
- Kyle H Flippo
- Department of Pharmacology, University of Iowa, Iowa City, USA
| | - Stefan Strack
- Department of Pharmacology, University of Iowa, Iowa City, USA
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721
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Schmidt EA, Fee BE, Henry SC, Nichols AG, Shinohara ML, Rathmell JC, MacIver NJ, Coers J, Ilkayeva OR, Koves TR, Taylor GA. Metabolic Alterations Contribute to Enhanced Inflammatory Cytokine Production in Irgm1-deficient Macrophages. J Biol Chem 2017; 292:4651-4662. [PMID: 28154172 DOI: 10.1074/jbc.m116.770735] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Revised: 01/19/2017] [Indexed: 12/19/2022] Open
Abstract
The immunity-related GTPases (IRGs) are a family of proteins that are induced by interferon (IFN)-γ and play pivotal roles in immune and inflammatory responses. IRGs ostensibly function as dynamin-like proteins that bind to intracellular membranes and promote remodeling and trafficking of those membranes. Prior studies have shown that loss of Irgm1 in mice leads to increased lethality to bacterial infections as well as enhanced inflammation to non-infectious stimuli; however, the mechanisms underlying these phenotypes are unclear. In the studies reported here, we found that uninfected Irgm1-deficient mice displayed high levels of serum cytokines typifying profound autoinflammation. Similar increases in cytokine production were also seen in cultured, IFN-γ-primed macrophages that lacked Irgm1. A series of metabolic studies indicated that the enhanced cytokine production was associated with marked metabolic changes in the Irgm1-deficient macrophages, including increased glycolysis and an accumulation of long chain acylcarnitines. Cells were exposed to the glycolytic inhibitor, 2-deoxyglucose, or fatty acid synthase inhibitors to perturb the metabolic alterations, which resulted in dampening of the excessive cytokine production. These results suggest that Irgm1 deficiency drives metabolic dysfunction in macrophages in a manner that is cell-autonomous and independent of infectious triggers. This may be a significant contributor to excessive inflammation seen in Irgm1-deficient mice in different contexts.
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Affiliation(s)
| | - Brian E Fee
- the Geriatric Research, Education, and Clinical Center, Durham Veterans Affairs Health Care System, Durham, North Carolina 27705, and
| | - Stanley C Henry
- the Geriatric Research, Education, and Clinical Center, Durham Veterans Affairs Health Care System, Durham, North Carolina 27705, and
| | - Amanda G Nichols
- the Department of Pediatrics, Division of Pediatric Endocrinology and Diabetes
| | - Mari L Shinohara
- From the Departments of Molecular Genetics and Microbiology.,the Department of Immunology
| | - Jeffrey C Rathmell
- the Department of Pathology, Microbiology, and Immunology, Vanderbilt Center for Immunobiology, Vanderbilt University, Nashville, Tennessee 37232
| | - Nancie J MacIver
- the Department of Pediatrics, Division of Pediatric Endocrinology and Diabetes
| | - Jörn Coers
- From the Departments of Molecular Genetics and Microbiology
| | | | - Timothy R Koves
- the Duke Molecular Physiology Institute, and.,the Department of Medicine, Division of Geriatrics, and Center for the Study of Aging and Human Development, Duke University Medical Center, Durham, North Carolina 27710
| | - Gregory A Taylor
- From the Departments of Molecular Genetics and Microbiology, .,the Geriatric Research, Education, and Clinical Center, Durham Veterans Affairs Health Care System, Durham, North Carolina 27705, and.,the Department of Immunology.,the Department of Medicine, Division of Geriatrics, and Center for the Study of Aging and Human Development, Duke University Medical Center, Durham, North Carolina 27710
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722
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Shi G, McQuibban GA. The Mitochondrial Rhomboid Protease PARL Is Regulated by PDK2 to Integrate Mitochondrial Quality Control and Metabolism. Cell Rep 2017; 18:1458-1472. [DOI: 10.1016/j.celrep.2017.01.029] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Revised: 12/09/2016] [Accepted: 01/12/2017] [Indexed: 12/15/2022] Open
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723
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Le NT, Martin JF, Fujiwara K, Abe JI. Sub-cellular localization specific SUMOylation in the heart. Biochim Biophys Acta Mol Basis Dis 2017; 1863:2041-2055. [PMID: 28130202 DOI: 10.1016/j.bbadis.2017.01.018] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Revised: 11/21/2016] [Accepted: 01/09/2017] [Indexed: 12/27/2022]
Abstract
Although the majority of SUMO substrates are localized in the nucleus, SUMOylation is not limited to nuclear proteins and can be also detected in extra-nuclear proteins. In this review, we will highlight and discuss how SUMOylation in different cellular compartments regulate biological processes. First, we will discuss the key role of SUMOylation of proteins in the extra-nuclear compartment in cardiomyocytes, which is overwhelmingly cardio-protective. On the other hand, SUMOylation of nuclear proteins is generally detrimental to the cardiac function mainly because of the trans-repressive nature of SUMOylation on many transcription factors. We will also discuss the potential role of SUMOylation in epigenetic regulation. In this review, we will propose a new concept that shuttling of SUMO proteases between the nuclear and extra-nuclear compartments without changing their enzymatic activity regulates the extent of SUMOylation in these compartments and determines the response and fate of cardiomyocytes after cardiac insults. Approaches focused specifically to inhibit this shuttling in cardiomyocytes will be necessary to understand the whole picture of SUMOylation and its pathophysiological consequences in the heart, especially after cardiac insults. This article is part of a Special Issue entitled: Genetic and epigenetic control of heart failure - edited by Jun Ren & Megan Yingmei Zhang.
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Affiliation(s)
- Nhat-Tu Le
- Department of Cardiology - Research, Division of Internal Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - James F Martin
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
| | - Keigi Fujiwara
- Department of Cardiology - Research, Division of Internal Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Jun-Ichi Abe
- Department of Cardiology - Research, Division of Internal Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
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724
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Cao YL, Meng S, Chen Y, Feng JX, Gu DD, Yu B, Li YJ, Yang JY, Liao S, Chan DC, Gao S. MFN1 structures reveal nucleotide-triggered dimerization critical for mitochondrial fusion. Nature 2017; 542:372-376. [PMID: 28114303 PMCID: PMC5319402 DOI: 10.1038/nature21077] [Citation(s) in RCA: 213] [Impact Index Per Article: 30.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Accepted: 01/03/2017] [Indexed: 12/11/2022]
Abstract
Mitochondria are double-membraned organelles with variable shapes influenced by metabolic conditions, developmental stage, and environmental stimuli. Their dynamic morphology is a result of regulated and balanced fusion and fission processes. Fusion is crucial for the health and physiological functions of mitochondria, including complementation of damaged mitochondrial DNAs and the maintenance of membrane potential. Mitofusins are dynamin-related GTPases that are essential for mitochondrial fusion. They are embedded in the mitochondrial outer membrane and thought to fuse adjacent mitochondria via combined oligomerization and GTP hydrolysis. However, the molecular mechanisms of this process remain unknown. Here we present crystal structures of engineered human MFN1 containing the GTPase domain and a helical domain during different stages of GTP hydrolysis. The helical domain is composed of elements from widely dispersed sequence regions of MFN1 and resembles the 'neck' of the bacterial dynamin-like protein. The structures reveal unique features of its catalytic machinery and explain how GTP binding induces conformational changes to promote GTPase domain dimerization in the transition state. Disruption of GTPase domain dimerization abolishes the fusogenic activity of MFN1. Moreover, a conserved aspartate residue trigger was found to affect mitochondrial elongation in MFN1, probably through a GTP-loading-dependent domain rearrangement. Thus, we propose a mechanistic model for MFN1-mediated mitochondrial tethering, and our results shed light on the molecular basis of mitochondrial fusion and mitofusin-related human neuromuscular disorders.
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Affiliation(s)
- Yu-Lu Cao
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou 510060, China
| | - Shuxia Meng
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, California 91125, USA
| | - Yang Chen
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou 510060, China
| | - Jian-Xiong Feng
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou 510060, China
| | - Dong-Dong Gu
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou 510060, China
| | - Bing Yu
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou 510060, China
| | - Yu-Jie Li
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou 510060, China
| | - Jin-Yu Yang
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou 510060, China
| | - Shuang Liao
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou 510060, China
| | - David C Chan
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, California 91125, USA
| | - Song Gao
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou 510060, China
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725
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Mitochondrial fusion dynamics is robust in the heart and depends on calcium oscillations and contractile activity. Proc Natl Acad Sci U S A 2017; 114:E859-E868. [PMID: 28096338 DOI: 10.1073/pnas.1617288114] [Citation(s) in RCA: 109] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Mitochondrial fusion is thought to be important for supporting cardiac contractility, but is hardly detectable in cultured cardiomyocytes and is difficult to directly evaluate in the heart. We overcame this obstacle through in vivo adenoviral transduction with matrix-targeted photoactivatable GFP and confocal microscopy. Imaging in whole rat hearts indicated mitochondrial network formation and fusion activity in ventricular cardiomyocytes. Promptly after isolation, cardiomyocytes showed extensive mitochondrial connectivity and fusion, which decayed in culture (at 24-48 h). Fusion manifested both as rapid content mixing events between adjacent organelles and slower events between both neighboring and distant mitochondria. Loss of fusion in culture likely results from the decline in calcium oscillations/contractile activity and mitofusin 1 (Mfn1), because (i) verapamil suppressed both contraction and mitochondrial fusion, (ii) after spontaneous contraction or short-term field stimulation fusion activity increased in cardiomyocytes, and (iii) ryanodine receptor-2-mediated calcium oscillations increased fusion activity in HEK293 cells and complementing changes occurred in Mfn1. Weakened cardiac contractility in vivo in alcoholic animals is also associated with depressed mitochondrial fusion. Thus, attenuated mitochondrial fusion might contribute to the pathogenesis of cardiomyopathy.
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726
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Devaraju P, Zakharenko SS. Mitochondria in complex psychiatric disorders: Lessons from mouse models of 22q11.2 deletion syndrome: Hemizygous deletion of several mitochondrial genes in the 22q11.2 genomic region can lead to symptoms associated with neuropsychiatric disease. Bioessays 2017; 39. [PMID: 28044359 DOI: 10.1002/bies.201600177] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Mitochondrial ATP synthesis, calcium buffering, and trafficking affect neuronal function and survival. Several genes implicated in mitochondrial functions map within the genomic region associated with 22q11.2 deletion syndrome (22q11DS), which is a key genetic cause of neuropsychiatric diseases. Although neuropsychiatric diseases impose a serious health and economic burden, their etiology and pathogenesis remain largely unknown because of the dearth of valid animal models and the challenges in investigating the pathophysiology in neuronal circuits. Mouse models of 22q11DS are becoming valid tools for studying human psychiatric diseases, because they have hemizygous deletions of the genes that are deleted in patients and exhibit neuronal and behavioral abnormalities consistent with neuropsychiatric disease. The deletion of some 22q11DS genes implicated in mitochondrial function leads to abnormal neuronal and synaptic function. Herein, we summarize recent findings on mitochondrial dysfunction in 22q11DS and extend those findings to the larger context of schizophrenia and other neuropsychiatric diseases.
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Affiliation(s)
- Prakash Devaraju
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Stanislav S Zakharenko
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN, USA
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727
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Abe JI, Sandhu UG, Hoang NM, Thangam M, Quintana-Quezada RA, Fujiwara K, Le NT. Coordination of Cellular Localization-Dependent Effects of Sumoylation in Regulating Cardiovascular and Neurological Diseases. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 963:337-358. [PMID: 28197922 PMCID: PMC5716632 DOI: 10.1007/978-3-319-50044-7_20] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Sumoylation, a reversible post-transcriptional modification process, of proteins are involved in cellular differentiation, growth, and even motility by regulating various protein functions. Sumoylation is not limited to cytosolic proteins as recent evidence shows that nuclear proteins, those associated with membranes, and mitochondrial proteins are also sumoylated. Moreover, it is now known that sumoylation plays an important role in the process of major human ailments such as malignant, cardiovascular and neurological diseases. In this chapter, we will highlight and discuss how the localization of SUMO protease and SUMO E3 ligase in different compartments within a cell regulates biological processes that depend on sumoylation. First, we will discuss the key role of sumoylation in the nucleus, which leads to the development of endothelial dysfunction and atherosclerosis . We will then discuss how sumoylation of plasma membrane potassium channel proteins are involved in epilepsy and arrhythmia. Mitochondrial proteins are known to be also sumoylated, and the importance of dynamic-related protein 1 (DRP1) sumoylation on mitochondrial function will be discussed. As we will emphasize throughout this review, sumoylation plays crucial roles in different cellular compartments, which is coordinately regulated by the translocation of various SUMO proteases and SUMO E3 ligase. Comprehensive approach will be necessary to understand the molecular mechanism for efficiently moving around various enzymes that regulate sumoylation within cells.
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Affiliation(s)
- Jun-Ichi Abe
- Department of Cardiology - Research, Division of Internal Medicine, The University of Texas MD Anderson Cancer Center, 2121 W. Holcombe Blvd, Unit Number: 1101, Room Number: IBT8.803E, Houston, TX, 77030, USA.
| | - Uday G Sandhu
- Department of Cardiology - Research, Division of Internal Medicine, The University of Texas MD Anderson Cancer Center, 2121 W. Holcombe Blvd, Unit Number: 1101, Room Number: IBT8.803E, Houston, TX, 77030, USA
| | - Nguyet Minh Hoang
- Department of Cardiology - Research, Division of Internal Medicine, The University of Texas MD Anderson Cancer Center, 2121 W. Holcombe Blvd, Unit Number: 1101, Room Number: IBT8.803E, Houston, TX, 77030, USA
| | - Manoj Thangam
- Department of Cardiology - Research, Division of Internal Medicine, The University of Texas MD Anderson Cancer Center, 2121 W. Holcombe Blvd, Unit Number: 1101, Room Number: IBT8.803E, Houston, TX, 77030, USA
| | - Raymundo A Quintana-Quezada
- Department of Cardiology - Research, Division of Internal Medicine, The University of Texas MD Anderson Cancer Center, 2121 W. Holcombe Blvd, Unit Number: 1101, Room Number: IBT8.803E, Houston, TX, 77030, USA
| | - Keigi Fujiwara
- Department of Cardiology - Research, Division of Internal Medicine, The University of Texas MD Anderson Cancer Center, 2121 W. Holcombe Blvd, Unit Number: 1101, Room Number: IBT8.803E, Houston, TX, 77030, USA
| | - Nhat Tu Le
- Department of Cardiology - Research, Division of Internal Medicine, The University of Texas MD Anderson Cancer Center, 2121 W. Holcombe Blvd, Unit Number: 1101, Room Number: IBT8.803E, Houston, TX, 77030, USA
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728
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Regulation of Mitochondrial Dynamics and Autophagy by the Mitochondria-Associated Membrane. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 997:33-47. [DOI: 10.1007/978-981-10-4567-7_3] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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729
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Herst PM, Rowe MR, Carson GM, Berridge MV. Functional Mitochondria in Health and Disease. Front Endocrinol (Lausanne) 2017; 8:296. [PMID: 29163365 PMCID: PMC5675848 DOI: 10.3389/fendo.2017.00296] [Citation(s) in RCA: 176] [Impact Index Per Article: 25.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Accepted: 10/16/2017] [Indexed: 01/10/2023] Open
Abstract
The ability to rapidly adapt cellular bioenergetic capabilities to meet rapidly changing environmental conditions is mandatory for normal cellular function and for cancer progression. Any loss of this adaptive response has the potential to compromise cellular function and render the cell more susceptible to external stressors such as oxidative stress, radiation, chemotherapeutic drugs, and hypoxia. Mitochondria play a vital role in bioenergetic and biosynthetic pathways and can rapidly adjust to meet the metabolic needs of the cell. Increased demand is met by mitochondrial biogenesis and fusion of individual mitochondria into dynamic networks, whereas a decrease in demand results in the removal of superfluous mitochondria through fission and mitophagy. Effective communication between nucleus and mitochondria (mito-nuclear cross talk), involving the generation of different mitochondrial stress signals as well as the nuclear stress response pathways to deal with these stressors, maintains bioenergetic homeostasis under most conditions. However, when mitochondrial DNA (mtDNA) mutations accumulate and mito-nuclear cross talk falters, mitochondria fail to deliver critical functional outputs. Mutations in mtDNA have been implicated in neuromuscular and neurodegenerative mitochondriopathies and complex diseases such as diabetes, cardiovascular diseases, gastrointestinal disorders, skin disorders, aging, and cancer. In some cases, drastic measures such as acquisition of new mitochondria from donor cells occurs to ensure cell survival. This review starts with a brief discussion of the evolutionary origin of mitochondria and summarizes how mutations in mtDNA lead to mitochondriopathies and other degenerative diseases. Mito-nuclear cross talk, including various stress signals generated by mitochondria and corresponding stress response pathways activated by the nucleus are summarized. We also introduce and discuss a small family of recently discovered hormone-like mitopeptides that modulate body metabolism. Under conditions of severe mitochondrial stress, mitochondria have been shown to traffic between cells, replacing mitochondria in cells with damaged and malfunctional mtDNA. Understanding the processes involved in cellular bioenergetics and metabolic adaptation has the potential to generate new knowledge that will lead to improved treatment of many of the metabolic, degenerative, and age-related inflammatory diseases that characterize modern societies.
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Affiliation(s)
- Patries M. Herst
- Cancer Cell Biology, Malaghan Institute of Medical Research, Wellington, New Zealand
- Department of Radiation Therapy, University of Otago, Wellington, New Zealand
- *Correspondence: Patries M. Herst, ; Michael V. Berridge,
| | - Matthew R. Rowe
- School of Biological Sciences, Victoria University, Wellington, New Zealand
| | - Georgia M. Carson
- Cancer Cell Biology, Malaghan Institute of Medical Research, Wellington, New Zealand
- School of Biological Sciences, Victoria University, Wellington, New Zealand
| | - Michael V. Berridge
- Cancer Cell Biology, Malaghan Institute of Medical Research, Wellington, New Zealand
- *Correspondence: Patries M. Herst, ; Michael V. Berridge,
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730
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Kooijman EE, Swim LA, Graber ZT, Tyurina YY, Bayır H, Kagan VE. Magic angle spinning 31P NMR spectroscopy reveals two essentially identical ionization states for the cardiolipin phosphates in phospholipid liposomes. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2017; 1859:61-68. [PMID: 27984017 PMCID: PMC5362297 DOI: 10.1016/j.bbamem.2016.10.013] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Revised: 10/20/2016] [Accepted: 10/25/2016] [Indexed: 01/04/2023]
Abstract
Specific membrane lipid composition is crucial for optimized structural and functional organization of biological membranes. Cardiolipin is a unique phospholipid and important component of the inner mitochondrial membrane. It is involved in energy metabolism, inner mitochondrial membrane transport, regulation of multiple metabolic reactions and apoptotic cell death. The physico-chemical properties of cardiolipin have been studied extensively but despite all these efforts there is still lingering controversy regarding the ionization of the two phosphate groups of cardiolipin. Results obtained in the 1990s and early 2000s suggested that cardiolipin has two disparate pKa values where one of the protons was proposed to be stabilized by an intramolecular hydrogen bond. This has led to extensive speculations on the roles of these two putative ionization states of cardiolipin in mitochondria. More recently the notion of two pKa values has been challenged and rejected by several groups. These studies relied on external measurements of proton adsorption or electrophoretic mobility of membranes but did not take into account the low pH phase behavior and chemical stability of cardiolipin. Here we used 31P NMR to show that in the physiologically relevant membrane phospholipid environment, cardiolipin carries two negative charges at physiological pH. We additionally demonstrate the pH dependent phase behavior and chemical stability of cardiolipin containing membranes.
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Affiliation(s)
- E E Kooijman
- Department of Biological Sciences, Kent State University, Kent, OH, United States.
| | - L A Swim
- Department of Biological Sciences, Kent State University, Kent, OH, United States
| | - Z T Graber
- Department of Chemistry and Biochemistry, Kent State University, Kent, OH, United States
| | - Y Y Tyurina
- Department of Environmental and Occupational Health, University of Pittsburgh, Pittsburgh, PA, United States
| | - H Bayır
- Department of Critical Care Medicine, University of Pittsburgh, Pittsburgh, PA, United States
| | - V E Kagan
- Department of Environmental and Occupational Health, University of Pittsburgh, Pittsburgh, PA, United States
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731
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Popov LD. Mitochondrial networking in diabetic left ventricle cardiomyocytes. Mitochondrion 2016; 34:24-31. [PMID: 28007605 DOI: 10.1016/j.mito.2016.12.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Revised: 10/07/2016] [Accepted: 12/16/2016] [Indexed: 12/17/2022]
Abstract
Cardiomyocyte mitochondria preserve "the quorum sensing" attribute of their aerobic bacterial ancestors, as shown by the transient physical connectivity and communication not only with each other, but also with other intracellular organelles and with cytosol, ensuing cellular homeostasis. In this review, we present original electron microscopy evidence on mitochondrial networking within diabetic left ventricular cardiomyocytes, focusing on: (i) the inter-mitochondrial communication, allowing electrochemical signals transfer and outer membrane components or matrix proteins exchange, (ii) the interplay between mitochondria and the cardiomyocyte nucleus, nucleolus, sarcoplasmic reticulum, lysosomes, and lipid droplets viewed as attributes of mitochondrial "quality control" and "retrograde signaling function", and (iii) the crosstalk between mitochondria and cardiomyocyte cytosol, as part of the adaptive responses that allow cells survival. Confirmation of such interactions in diabetic myocardium and identification of molecules involved are ongoing, foreseeing the alleviation of heart contractile dysfunction in cardiomyopathy.
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Affiliation(s)
- Lucia-Doina Popov
- "Nicolae Simionescu" Institute of Cellular Biology and Pathology of the Romanian Academy, 8, B.P. Hasdeu Street, Bucharest 050568, Romania.
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732
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Vyas S, Zaganjor E, Haigis MC. Mitochondria and Cancer. Cell 2016; 166:555-566. [PMID: 27471965 DOI: 10.1016/j.cell.2016.07.002] [Citation(s) in RCA: 1090] [Impact Index Per Article: 136.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Revised: 06/17/2016] [Accepted: 06/29/2016] [Indexed: 01/17/2023]
Abstract
Mitochondria are bioenergetic, biosynthetic, and signaling organelles that are integral in stress sensing to allow for cellular adaptation to the environment. Therefore, it is not surprising that mitochondria are important mediators of tumorigenesis, as this process requires flexibility to adapt to cellular and environmental alterations in addition to cancer treatments. Multiple aspects of mitochondrial biology beyond bioenergetics support transformation, including mitochondrial biogenesis and turnover, fission and fusion dynamics, cell death susceptibility, oxidative stress regulation, metabolism, and signaling. Thus, understanding mechanisms of mitochondrial function during tumorigenesis will be critical for the next generation of cancer therapeutics.
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Affiliation(s)
- Sejal Vyas
- Department of Cell Biology, Ludwig Center at Harvard, Harvard Medical School, Boston, MA 02115, USA
| | - Elma Zaganjor
- Department of Cell Biology, Ludwig Center at Harvard, Harvard Medical School, Boston, MA 02115, USA
| | - Marcia C Haigis
- Department of Cell Biology, Ludwig Center at Harvard, Harvard Medical School, Boston, MA 02115, USA.
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733
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N-Myc overexpression increases cisplatin resistance in neuroblastoma via deregulation of mitochondrial dynamics. Cell Death Discov 2016; 2:16082. [PMID: 28028439 PMCID: PMC5149579 DOI: 10.1038/cddiscovery.2016.82] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Accepted: 09/04/2016] [Indexed: 12/23/2022] Open
Abstract
N-Myc is a global transcription factor that regulates the expression of genes involved in a number of essential cellular processes including: ribosome biogenesis, cell cycle and apoptosis. Upon deregulation, N-Myc can drive pathologic expression of many of these genes, which ultimately defines its oncogenic potential. Overexpression of N-Myc has been demonstrated to contribute to tumorigenesis, most notably for the pediatric tumor, neuroblastoma. Herein, we provide evidence that deregulated N-Myc alters the expression of proteins involved in mitochondrial dynamics. We found that N-Myc overexpression leads to increased fusion of the mitochondrial reticulum secondary to changes in protein expression due to aberrant transcriptional and post-translational regulation. We believe the structural changes in the mitochondrial network in response to N-Myc amplification in neuroblastoma contributes to two important aspects of tumor development and maintenance—bioenergetic alterations and apoptotic resistance. Specifically, we found that N-Myc overexpressing cells are resistant to programmed cell death in response to exposure to low doses of cisplatin, and demonstrated that this was dependent on increased mitochondrial fusion. We speculate that these changes in mitochondrial structure and function may contribute significantly to the aggressive clinical ph9enotype of N-Myc amplified neuroblastoma.
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734
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Cherok E, Xu S, Li S, Das S, Meltzer WA, Zalzman M, Wang C, Karbowski M. Novel regulatory roles of Mff and Drp1 in E3 ubiquitin ligase MARCH5-dependent degradation of MiD49 and Mcl1 and control of mitochondrial dynamics. Mol Biol Cell 2016; 28:396-410. [PMID: 27932492 PMCID: PMC5341724 DOI: 10.1091/mbc.e16-04-0208] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Revised: 11/30/2016] [Accepted: 12/01/2016] [Indexed: 12/15/2022] Open
Abstract
In addition to their direct roles in mitochondrial fission, Mff and Drp1 act as regulatory factors and control mitochondrial fission and fusion through a Ub-dependent mechanism. The E3 Ub ligase MARCH5 is negatively controlled by Mff and Drp1. MARCH5, an OMM-associated E3 ubiquitin ligase, controls mitochondrial function. Despite its importance, the mechanism and factors controlling MARCH5 activity are largely unknown. Here we report that the MARCH5 C-terminal domain plays a critical role in degradation of MARCH5 substrates, likely by facilitating release of ubiquitinated proteins from the OMM. We also found that the mitochondrial fission proteins Drp1 and Mff negatively regulate MARCH5’s activity toward MiD49 and Mcl1. Knockouts of either Drp1 or Mff led to reduced expression, shorter half-lives, and increased ubiquitination of MiD49 and Mcl1. Effects of Mff and Drp1 depletion on degradation rates and ubiquitination of Mcl1 and MiD49 were eliminated in Drp1−/−/MARCH5−/− and Mff−/−/MARCH5−/− cells. Our data show that it is not mitochondrial morphology per se but rather Mff and Drp1 that directly control MARCH5. Consistently, we find that Mff is an integral component of the MARCH5/p97/Npl4 complex, which is also controlled by MARCH5’s C-terminal domain. Furthermore, not only mitochondrial fission but also fusion is regulated through Mff and Drp1 protein activities. Thus, in addition to their canonical roles in mitochondrial fission, Mff and Drp1 also act as regulatory factors that control mitochondrial fission and fusion.
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Affiliation(s)
- Edward Cherok
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD 21201.,Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD 21201
| | - Shan Xu
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD 21201.,Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD 21201
| | - Sunan Li
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD 21201.,Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD 21201
| | - Shweta Das
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD 21201.,Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD 21201
| | - W Alex Meltzer
- Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD 21201
| | - Michal Zalzman
- Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD 21201
| | - Chunxin Wang
- Biochemistry Section, Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892
| | - Mariusz Karbowski
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD 21201.,Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD 21201.,Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD 21201
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735
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Balog J, Mehta SL, Vemuganti R. Mitochondrial fission and fusion in secondary brain damage after CNS insults. J Cereb Blood Flow Metab 2016; 36:2022-2033. [PMID: 27677674 PMCID: PMC5363672 DOI: 10.1177/0271678x16671528] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2009] [Revised: 08/15/2016] [Accepted: 09/05/2016] [Indexed: 11/15/2022]
Abstract
Mitochondria are dynamically active organelles, regulated through fission and fusion events to continuously redistribute them across axons, dendrites, and synapses of neurons to meet bioenergetics requirements and to control various functions, including cell proliferation, calcium buffering, neurotransmission, oxidative stress, and apoptosis. However, following acute or chronic injury to CNS, altered expression and function of proteins that mediate fission and fusion lead to mitochondrial dynamic imbalance. Particularly, if the fission is abnormally increased through pro-fission mediators such as Drp1, mitochondrial function will be impaired and mitochondria will become susceptible to insertion of proapototic proteins. This leads to the formation of mitochondrial transition pore, which eventually triggers apoptosis. Thus, mitochondrial dysfunction is a major promoter of neuronal death and secondary brain damage after an insult. This review discusses the implications of mitochondrial dynamic imbalance in neuronal death after acute and chronic CNS insults.
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Affiliation(s)
- Justin Balog
- Department of Neurological Surgery, University of Wisconsin, Madison, WI, USA
| | - Suresh L Mehta
- Department of Neurological Surgery, University of Wisconsin, Madison, WI, USA.,William S. Middleton Veterans Administration Hospital, Madison, WI, USA
| | - Raghu Vemuganti
- Department of Neurological Surgery, University of Wisconsin, Madison, WI, USA .,Neuroscience Training Program, University of Wisconsin, Madison, WI, USA.,Cellular & Molecular Pathology Training Program, University of Wisconsin, Madison, WI, USA.,William S. Middleton Veterans Administration Hospital, Madison, WI, USA
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736
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Seifert EL, Gál A, Acoba MG, Li Q, Anderson-Pullinger L, Golenár T, Moffat C, Sondheimer N, Claypool SM, Hajnóczky G. Natural and Induced Mitochondrial Phosphate Carrier Loss: DIFFERENTIAL DEPENDENCE OF MITOCHONDRIAL METABOLISM AND DYNAMICS AND CELL SURVIVAL ON THE EXTENT OF DEPLETION. J Biol Chem 2016; 291:26126-26137. [PMID: 27780865 DOI: 10.1074/jbc.m116.744714] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Revised: 10/06/2016] [Indexed: 12/22/2022] Open
Abstract
The relevance of mitochondrial phosphate carrier (PiC), encoded by SLC25A3, in bioenergetics is well accepted. However, little is known about the mechanisms mediating the cellular impairments induced by pathological SLC25A3 variants. To this end, we investigated the pathogenicity of a novel compound heterozygous mutation in SLC25A3 First, each variant was modeled in yeast, revealing that substituting GSSAS for QIP within the fifth matrix loop is incompatible with survival on non-fermentable substrate, whereas the L200W variant is functionally neutral. Next, using skin fibroblasts from an individual expressing these variants and HeLa cells with varying degrees of PiC depletion, PiC loss of ∼60% was still compatible with uncompromised maximal oxidative phosphorylation (oxphos), whereas lower maximal oxphos was evident at ∼85% PiC depletion. Furthermore, intact mutant fibroblasts displayed suppressed mitochondrial bioenergetics consistent with a lower substrate availability rather than phosphate limitation. This was accompanied by slowed proliferation in glucose-replete medium; however, proliferation ceased when only mitochondrial substrate was provided. Both mutant fibroblasts and HeLa cells with 60% PiC loss showed a less interconnected mitochondrial network and a mitochondrial fusion defect that is not explained by altered abundance of OPA1 or MFN1/2 or relative amount of different OPA1 forms. Altogether these results indicate that PiC depletion may need to be profound (>85%) to substantially affect maximal oxphos and that pathogenesis associated with PiC depletion or loss of function may be independent of phosphate limitation when ATP requirements are not high.
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Affiliation(s)
- Erin L Seifert
- From the MitoCare Center for Imaging Research and Diagnostics, Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107,
| | - Aniko Gál
- From the MitoCare Center for Imaging Research and Diagnostics, Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107
| | - Michelle G Acoba
- Department of Physiology, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, and
| | - Qipei Li
- From the MitoCare Center for Imaging Research and Diagnostics, Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107
| | - Lauren Anderson-Pullinger
- From the MitoCare Center for Imaging Research and Diagnostics, Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107
| | - Tunde Golenár
- From the MitoCare Center for Imaging Research and Diagnostics, Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107
| | - Cynthia Moffat
- From the MitoCare Center for Imaging Research and Diagnostics, Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107
| | - Neal Sondheimer
- Division of Clinical and Metabolic Genetics, Hospital for Sick Children and Department of Paediatrics, University of Toronto, Toronto, Ontario M5G 1X8, Canada
| | - Steven M Claypool
- Department of Physiology, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, and
| | - György Hajnóczky
- From the MitoCare Center for Imaging Research and Diagnostics, Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107,
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737
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Pradhan P, Upadhyay N, Tiwari A, Singh LP. Genetic and epigenetic modifications in the pathogenesis of diabetic retinopathy: a molecular link to regulate gene expression. ACTA ACUST UNITED AC 2016; 2:192-204. [PMID: 28691104 DOI: 10.15761/nfo.1000145] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Intensification in the frequency of diabetes and the associated vascular complications has been a root cause of blindness and visual impairment worldwide. One such vascular complication which has been the prominent cause of blindness; retinal vasculature, neuronal and glial abnormalities is diabetic retinopathy (DR), a chronic complicated outcome of Type 1 and Type 2 diabetes. It has also become clear that "genetic" variations in population alone can't explain the development and progression of diabetes and its complications including DR. DR experiences engagement of foremost mediators of diabetes such as hyperglycemia, oxidant stress, and inflammatory factors that lead to the dysregulation of "epigenetic" mechanisms involving histone acetylation and histone and DNA methylation, chromatin remodeling and expression of a complex set of stress-regulated and disease-associated genes. In addition, both elevated glucose concentration and insulin resistance leave a robust effect on epigenetic reprogramming of the endothelial cells too, since endothelium associated with the eye aids in maintaining the vascular homeostasis. Furthermore, several studies conducted on the disease suggest that the modifications of the epigenome might be the fundamental mechanism(s) for the proposed metabolic memory' resulting into prolonged gene expression for inflammation and cellular dysfunction even after attaining the glycemic control in diabetics. Henceforth, the present review focuses on the aspects of genetic and epigenetic alterations in genes such as vascular endothelial growth factor and aldose reductase considered being associated with DR. In addition, we discuss briefly the role of the thioredoxin-interacting protein TXNIP, which is strongly induced by high glucose and diabetes, in cellular oxidative stress and mitochondrial dysfunction potentially leading to chromatin remodeling and ocular complications of diabetes. The identification of disease-associated genes and their epigenetic regulations will lead to potential new drugs and gene therapies as well as personalized medicine to prevent or slow down the progression of DR.
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Affiliation(s)
- Priya Pradhan
- School of Biotechnology, Rajiv Gandhi Technical University, Bhopal, Madhya Pradesh, India
| | - Nisha Upadhyay
- School of Biotechnology, Rajiv Gandhi Technical University, Bhopal, Madhya Pradesh, India
| | - Archana Tiwari
- School of Biotechnology, Rajiv Gandhi Technical University, Bhopal, Madhya Pradesh, India
| | - Lalit P Singh
- Departments of Anatomy/Cell Biology and Ophthalmology, School of Medicine, Wayne State University, Detroit, MI, USA
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738
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Kim DI, Lee KH, Oh JY, Kim JS, Han HJ. Relationship Between β-Amyloid and Mitochondrial Dynamics. Cell Mol Neurobiol 2016; 37:955-968. [PMID: 27766447 DOI: 10.1007/s10571-016-0434-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Accepted: 10/13/2016] [Indexed: 01/29/2023]
Abstract
Mitochondria as dynamic organelles undergo morphological changes through the processes of fission and fusion which are major factors regulating their functions. A disruption in the balance of mitochondrial dynamics induces functional disorders in mitochondria such as failed energy production and the generation of reactive oxygen species, which are closely related to pathophysiological changes associated with Alzheimer's disease (AD). Recent studies have demonstrated a relationship between abnormalities in mitochondrial dynamics and impaired mitochondrial function, clarifying the effects of morphofunctional aberrations which promote neuronal cell death in AD. Several possible signaling pathways have been suggested for a better understanding of the mechanism behind the key molecules regulating mitochondrial morphologies. However, the exact machinery involved in mitochondrial dynamics still has yet to be elucidated. This paper reviews the current knowledge on signaling mechanisms involved in mitochondrial dynamics and the significance of mitochondrial dynamics in controlling associated functions in neurodegenerative diseases, particularly in AD.
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Affiliation(s)
- Dah Ihm Kim
- Department of Veterinary Physiology, College of Veterinary Medicine, Research Institute for Veterinary Science, Seoul National University, Seoul, 08826, South Korea
| | - Ki Hoon Lee
- Department of Veterinary Physiology, College of Veterinary Medicine, Research Institute for Veterinary Science, Seoul National University, Seoul, 08826, South Korea
| | - Ji Young Oh
- Department of Agricultural Biotechnology, Animal Biotechnology Major, and Research Institute of Agriculture and Life Science, Seoul National University, Seoul, 08826, South Korea
| | - Jun Sung Kim
- Department of Veterinary Physiology, College of Veterinary Medicine, Research Institute for Veterinary Science, Seoul National University, Seoul, 08826, South Korea
| | - Ho Jae Han
- Department of Veterinary Physiology, College of Veterinary Medicine, Research Institute for Veterinary Science, Seoul National University, Seoul, 08826, South Korea. .,BK21 PLUS Creative Veterinary Research Center, Seoul National University, Seoul, 08826, South Korea.
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739
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Tauroursodeoxycholic Acid Protects Against Mitochondrial Dysfunction and Cell Death via Mitophagy in Human Neuroblastoma Cells. Mol Neurobiol 2016; 54:6107-6119. [PMID: 27699602 DOI: 10.1007/s12035-016-0145-3] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Accepted: 09/19/2016] [Indexed: 12/12/2022]
Abstract
Mitochondrial dysfunction has been deeply implicated in the pathogenesis of several neurodegenerative diseases. Thus, to keep a healthy mitochondrial population, a balanced mitochondrial turnover must be achieved. Tauroursodeoxycholic acid (TUDCA) is neuroprotective in various neurodegenerative disease models; however, the mechanisms involved are still incompletely characterized. In this study, we investigated the neuroprotective role of TUDCA against mitochondrial damage triggered by the mitochondrial uncoupler carbonyl cyanide m-chlorophelyhydrazone (CCCP). Herein, we show that TUDCA significantly prevents CCCP-induced cell death, ROS generation, and mitochondrial damage. Our results indicate that the neuroprotective role of TUDCA in this cell model is mediated by parkin and depends on mitophagy. The demonstration that pharmacological up-regulation of mitophagy by TUDCA prevents neurodegeneration provides new insights for the use of TUDCA as a modulator of mitochondrial activity and turnover, with implications in neurodegenerative diseases.
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740
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Coordinated Upregulation of Mitochondrial Biogenesis and Autophagy in Breast Cancer Cells: The Role of Dynamin Related Protein-1 and Implication for Breast Cancer Treatment. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2016; 2016:4085727. [PMID: 27746856 PMCID: PMC5056295 DOI: 10.1155/2016/4085727] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Revised: 08/12/2016] [Accepted: 08/23/2016] [Indexed: 01/10/2023]
Abstract
Overactive mitochondrial fission was shown to promote cell transformation and tumor growth. It remains elusive how mitochondrial quality is regulated in such conditions. Here, we show that upregulation of mitochondrial fission protein, dynamin related protein-1 (Drp1), was accompanied with increased mitochondrial biogenesis markers (PGC1α, NRF1, and Tfam) in breast cancer cells. However, mitochondrial number was reduced, which was associated with lower mitochondrial oxidative capacity in breast cancer cells. This contrast might be owing to enhanced mitochondrial turnover through autophagy, because an increased population of autophagic vacuoles engulfing mitochondria was observed in the cancer cells. Consistently, BNIP3 (a mitochondrial autophagy marker) and autophagic flux were significantly upregulated, indicative of augmented mitochondrial autophagy (mitophagy). The upregulation of Drp1 and BNIP3 was also observed in vivo (human breast carcinomas). Importantly, inhibition of Drp1 significantly suppressed mitochondrial autophagy, metabolic reprogramming, and cancer cell viability. Together, this study reveals coordinated increase of mitochondrial biogenesis and mitophagy in which Drp1 plays a central role regulating breast cancer cell metabolism and survival. Given the emerging evidence of PGC1α contributing to tumor growth, it will be of critical importance to target both mitochondrial biogenesis and mitophagy for effective cancer therapeutics.
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741
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Zeituni EM, Wilson MH, Zheng X, Iglesias PA, Sepanski MA, Siddiqi MA, Anderson JL, Zheng Y, Farber SA. Endoplasmic Reticulum Lipid Flux Influences Enterocyte Nuclear Morphology and Lipid-dependent Transcriptional Responses. J Biol Chem 2016; 291:23804-23816. [PMID: 27655916 DOI: 10.1074/jbc.m116.749358] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Indexed: 12/12/2022] Open
Abstract
Responding to a high-fat meal requires an interplay between multiple digestive tissues, sympathetic response pathways, and the gut microbiome. The epithelial enterocytes of the intestine are responsible for absorbing dietary nutrients and preparing them for circulation to distal tissues, which requires significant changes in cellular activity, including both morphological and transcriptional responses. Following a high-fat meal, we observe morphological changes in the enterocytes of larval zebrafish, including elongation of mitochondria, formation and expansion of lipid droplets, and the rapid and transient ruffling of the nuclear periphery. Dietary and pharmacological manipulation of zebrafish larvae demonstrated that these subcellular changes are specific to triglyceride absorption. The transcriptional changes that occur simultaneously with these morphological changes were determined using RNA sequencing, revealing a cohort of up-regulated genes associated with lipid droplet formation and lipid transport via lipoprotein particles. Using a microsomal triglyceride transfer protein (MTP) inhibitor to block β-lipoprotein particle formation, we demonstrate that the transcriptional response to a high-fat meal is associated with the transfer of ER triglyceride to nascent β-lipoproteins, possibly through the activation of Creb3l3/cyclic AMP-responsive element-binding protein. These data suggest that a transient increase in ER lipids is the likely mediator of the initial physiological response of intestinal enterocytes to dietary lipid.
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Affiliation(s)
- Erin M Zeituni
- From the Department of Embryology, Carnegie Institution for Science, Baltimore, Maryland 21218 and
| | - Meredith H Wilson
- From the Department of Embryology, Carnegie Institution for Science, Baltimore, Maryland 21218 and
| | - Xiaobin Zheng
- From the Department of Embryology, Carnegie Institution for Science, Baltimore, Maryland 21218 and
| | - Pablo A Iglesias
- the Department of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, Maryland 21218
| | - Michael A Sepanski
- From the Department of Embryology, Carnegie Institution for Science, Baltimore, Maryland 21218 and
| | - Mahmud A Siddiqi
- From the Department of Embryology, Carnegie Institution for Science, Baltimore, Maryland 21218 and
| | - Jennifer L Anderson
- From the Department of Embryology, Carnegie Institution for Science, Baltimore, Maryland 21218 and
| | - Yixian Zheng
- From the Department of Embryology, Carnegie Institution for Science, Baltimore, Maryland 21218 and
| | - Steven A Farber
- From the Department of Embryology, Carnegie Institution for Science, Baltimore, Maryland 21218 and
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742
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Picard M, Wallace DC, Burelle Y. The rise of mitochondria in medicine. Mitochondrion 2016; 30:105-16. [PMID: 27423788 PMCID: PMC5023480 DOI: 10.1016/j.mito.2016.07.003] [Citation(s) in RCA: 294] [Impact Index Per Article: 36.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Revised: 07/04/2016] [Accepted: 07/12/2016] [Indexed: 12/11/2022]
Abstract
Once considered exclusively the cell's powerhouse, mitochondria are now recognized to perform multiple essential functions beyond energy production, impacting most areas of cell biology and medicine. Since the emergence of molecular biology and the discovery of pathogenic mitochondrial DNA defects in the 1980's, research advances have revealed a number of common human diseases which share an underlying pathogenesis involving mitochondrial dysfunction. Mitochondria undergo function-defining dynamic shape changes, communicate with each other, regulate gene expression within the nucleus, modulate synaptic transmission within the brain, release molecules that contribute to oncogenic transformation and trigger inflammatory responses systemically, and influence the regulation of complex physiological systems. Novel mitopathogenic mechanisms are thus being uncovered across a number of medical disciplines including genetics, oncology, neurology, immunology, and critical care medicine. Increasing knowledge of the bioenergetic aspects of human disease has provided new opportunities for diagnosis, therapy, prevention, and in connecting various domains of medicine. In this article, we overview specific aspects of mitochondrial biology that have contributed to - and likely will continue to enhance the progress of modern medicine.
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Affiliation(s)
- Martin Picard
- Department of Psychiatry, Division of Behavioral Medicine, Columbia University Medical Center, New York, NY, USA; Department of Neurology and CTNI, H Houston Merritt Center, Columbia University Medical Center, New York, NY, USA.
| | - Douglas C Wallace
- The Center for Mitochondrial and Epigenomic Medicine, Children's Hospital of Philadelphia and Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Yan Burelle
- Faculty of Pharmacy, Université de Montreal, Montreal, QC, Canada
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743
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Liu MY, Jin J, Li SL, Yan J, Zhen CL, Gao JL, Zhang YH, Zhang YQ, Shen X, Zhang LS, Wei YY, Zhao Y, Wang CG, Bai YL, Dong DL. Mitochondrial Fission of Smooth Muscle Cells Is Involved in Artery Constriction. Hypertension 2016; 68:1245-1254. [PMID: 27572148 DOI: 10.1161/hypertensionaha.116.07974] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Accepted: 08/10/2016] [Indexed: 01/21/2023]
Abstract
Mitochondria are dynamic organelles and continuously undergo fission and fusion processes. Mitochondrial fission is involved in multiple physiological or pathological processes, but the role of mitochondrial fission of smooth muscle cells in artery constriction is unknown. The role of mitochondrial fission of smooth muscle cells in arterial function was investigated by measuring the tension of rat mesenteric arteries and thoracic aorta and by evaluating mitochondrial fission, mitochondrial reactive oxygen species, and cytosolic [Ca2+]i in rat vascular smooth muscle cells. Mitochondrial fission inhibitors mdivi-1 and dynasore antagonized phenylephrine- and high K+-induced constriction of rat mesenteric arteries. Mdivi-1 relaxed phenylephrine-induced constriction, and mdivi-1 pretreatment prevented phenylephrine-induced constriction in mice, rat aorta, and human mesenteric arteries. Phenylephrine- and high K+-induced increase of mitochondrial fission in smooth muscle cells of rat aorta and the increase was inhibited by mdivi-1. Mdivi-1 inhibited high K+-induced increases of mitochondrial fission, mitochondrial reactive oxygen species, and cytosolic [Ca2+]i in rat vascular smooth muscle cells. Prechelation of cytosolic Ca2+ prevented high K+-induced cytosolic [Ca2+]i increase, mitochondrial fission, and mitochondrial reactive oxygen species overproduction. Mitochondria-targeted antioxidant mito-TEMPO antagonized phenylephrine- and high K+-induced constriction of rat mesenteric arteries. Nitroglycerin and ROCK (Rho-associated protein kinase) inhibitor Y27632, the 2 vasodilators with different vasorelaxant mechanisms, relaxed high K+-induced vasoconstriction and inhibited high K+-induced mitochondrial fission. In conclusion, the mitochondrial fission of smooth muscle cells is involved in artery constriction.
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Affiliation(s)
- Ming-Yu Liu
- From the Department of Pharmacology (the State-Province Key Laboratories of Biomedicine-Pharmaceutics of China, Key Laboratory of Cardiovascular Research, Ministry of Education), College of Pharmacy, Translational Medicine Research and Cooperation Center of Northern China, Heilongjiang Academy of Medical Sciences, Harbin Medical University
| | - Jing Jin
- From the Department of Pharmacology (the State-Province Key Laboratories of Biomedicine-Pharmaceutics of China, Key Laboratory of Cardiovascular Research, Ministry of Education), College of Pharmacy, Translational Medicine Research and Cooperation Center of Northern China, Heilongjiang Academy of Medical Sciences, Harbin Medical University
| | - Shan-Liang Li
- From the Department of Pharmacology (the State-Province Key Laboratories of Biomedicine-Pharmaceutics of China, Key Laboratory of Cardiovascular Research, Ministry of Education), College of Pharmacy, Translational Medicine Research and Cooperation Center of Northern China, Heilongjiang Academy of Medical Sciences, Harbin Medical University
| | - Jie Yan
- From the Department of Pharmacology (the State-Province Key Laboratories of Biomedicine-Pharmaceutics of China, Key Laboratory of Cardiovascular Research, Ministry of Education), College of Pharmacy, Translational Medicine Research and Cooperation Center of Northern China, Heilongjiang Academy of Medical Sciences, Harbin Medical University
| | - Chang-Lin Zhen
- From the Department of Pharmacology (the State-Province Key Laboratories of Biomedicine-Pharmaceutics of China, Key Laboratory of Cardiovascular Research, Ministry of Education), College of Pharmacy, Translational Medicine Research and Cooperation Center of Northern China, Heilongjiang Academy of Medical Sciences, Harbin Medical University
| | - Jin-Lai Gao
- From the Department of Pharmacology (the State-Province Key Laboratories of Biomedicine-Pharmaceutics of China, Key Laboratory of Cardiovascular Research, Ministry of Education), College of Pharmacy, Translational Medicine Research and Cooperation Center of Northern China, Heilongjiang Academy of Medical Sciences, Harbin Medical University
| | - Yong-Hui Zhang
- From the Department of Pharmacology (the State-Province Key Laboratories of Biomedicine-Pharmaceutics of China, Key Laboratory of Cardiovascular Research, Ministry of Education), College of Pharmacy, Translational Medicine Research and Cooperation Center of Northern China, Heilongjiang Academy of Medical Sciences, Harbin Medical University
| | - Yan-Qiu Zhang
- From the Department of Pharmacology (the State-Province Key Laboratories of Biomedicine-Pharmaceutics of China, Key Laboratory of Cardiovascular Research, Ministry of Education), College of Pharmacy, Translational Medicine Research and Cooperation Center of Northern China, Heilongjiang Academy of Medical Sciences, Harbin Medical University
| | - Xin Shen
- From the Department of Pharmacology (the State-Province Key Laboratories of Biomedicine-Pharmaceutics of China, Key Laboratory of Cardiovascular Research, Ministry of Education), College of Pharmacy, Translational Medicine Research and Cooperation Center of Northern China, Heilongjiang Academy of Medical Sciences, Harbin Medical University
| | - Liang-Shuan Zhang
- From the Department of Pharmacology (the State-Province Key Laboratories of Biomedicine-Pharmaceutics of China, Key Laboratory of Cardiovascular Research, Ministry of Education), College of Pharmacy, Translational Medicine Research and Cooperation Center of Northern China, Heilongjiang Academy of Medical Sciences, Harbin Medical University
| | - Yuan-Yuan Wei
- From the Department of Pharmacology (the State-Province Key Laboratories of Biomedicine-Pharmaceutics of China, Key Laboratory of Cardiovascular Research, Ministry of Education), College of Pharmacy, Translational Medicine Research and Cooperation Center of Northern China, Heilongjiang Academy of Medical Sciences, Harbin Medical University
| | - Yu Zhao
- From the Department of Pharmacology (the State-Province Key Laboratories of Biomedicine-Pharmaceutics of China, Key Laboratory of Cardiovascular Research, Ministry of Education), College of Pharmacy, Translational Medicine Research and Cooperation Center of Northern China, Heilongjiang Academy of Medical Sciences, Harbin Medical University
| | - Chen-Guang Wang
- From the Department of Pharmacology (the State-Province Key Laboratories of Biomedicine-Pharmaceutics of China, Key Laboratory of Cardiovascular Research, Ministry of Education), College of Pharmacy, Translational Medicine Research and Cooperation Center of Northern China, Heilongjiang Academy of Medical Sciences, Harbin Medical University
| | - Yun-Long Bai
- From the Department of Pharmacology (the State-Province Key Laboratories of Biomedicine-Pharmaceutics of China, Key Laboratory of Cardiovascular Research, Ministry of Education), College of Pharmacy, Translational Medicine Research and Cooperation Center of Northern China, Heilongjiang Academy of Medical Sciences, Harbin Medical University
| | - De-Li Dong
- From the Department of Pharmacology (the State-Province Key Laboratories of Biomedicine-Pharmaceutics of China, Key Laboratory of Cardiovascular Research, Ministry of Education), College of Pharmacy, Translational Medicine Research and Cooperation Center of Northern China, Heilongjiang Academy of Medical Sciences, Harbin Medical University.
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744
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Multiple Roles of the Small GTPase Rab7. Cells 2016; 5:cells5030034. [PMID: 27548222 PMCID: PMC5040976 DOI: 10.3390/cells5030034] [Citation(s) in RCA: 267] [Impact Index Per Article: 33.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Revised: 08/11/2016] [Accepted: 08/12/2016] [Indexed: 12/16/2022] Open
Abstract
Rab7 is a small GTPase that belongs to the Rab family and controls transport to late endocytic compartments such as late endosomes and lysosomes. The mechanism of action of Rab7 in the late endocytic pathway has been extensively studied. Rab7 is fundamental for lysosomal biogenesis, positioning and functions, and for trafficking and degradation of several signaling receptors, thus also having implications on signal transduction. Several Rab7 interacting proteins have being identified leading to the discovery of a number of different important functions, beside its established role in endocytosis. Furthermore, Rab7 has specific functions in neurons. This review highlights and discusses the role and the importance of Rab7 on different cellular pathways and processes.
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745
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Multiplexed high-content analysis of mitochondrial morphofunction using live-cell microscopy. Nat Protoc 2016; 11:1693-710. [PMID: 27560174 DOI: 10.1038/nprot.2016.094] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Mitochondria have a central role in cellular (patho)physiology, and they display a highly variable morphology that is probably coupled to their functional state. Here we present a protocol that allows unbiased and automated quantification of mitochondrial 'morphofunction' (i.e., morphology and membrane potential), cellular parameters (size, confluence) and nuclear parameters (number, morphology) in intact living primary human skin fibroblasts (PHSFs). Cells are cultured in 96-well plates and stained with tetramethyl rhodamine methyl ester (TMRM), calcein-AM (acetoxy-methyl ester) and Hoechst 33258. Next, multispectral fluorescence images are acquired using automated microscopy and processed to extract 44 descriptors. Subsequently, the descriptor data are subjected to a quality control (QC) algorithm based upon principal component analysis (PCA) and interpreted using univariate, bivariate and multivariate analysis. The protocol requires a time investment of ∼4 h distributed over 2 d. Although it is specifically developed for PHSFs, which are widely used in preclinical research, the protocol is portable to other cell types and can be scaled up for implementation in high-content screening.
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746
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Attenuation of Aβ toxicity by promotion of mitochondrial fusion in neuroblastoma cells by liquiritigenin. Arch Pharm Res 2016; 39:1137-43. [PMID: 27515055 DOI: 10.1007/s12272-016-0780-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Accepted: 06/20/2016] [Indexed: 02/06/2023]
Abstract
Mitochondrial dynamics control mitochondrial morphology and function, and aberrations in these are associated with various neurodegenerative diseases including Alzheimer's disease and Parkinson's disease. To identify novel regulators of mitochondrial dynamics, we screened a phytochemical library and identified liquiritigenin as a potent inducer of mitochondrial fusion. Treatment with liquiritigenin induced an elongated mitochondrial morphology in SK-N-MC cells. In addition, liquiritigenin rescued mitochondrial fragmentation induced by knockout of mitochondrial fusion mediators such as Mfn1, Mfn2, and Opa1. Furthermore, we found that treatment with liquiritigenin notably inhibited mitochondrial fragmentation and cytotoxicity induced by Aβ in SK-N-MC cells.
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747
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Zalfa C, Verpelli C, D'Avanzo F, Tomanin R, Vicidomini C, Cajola L, Manara R, Sala C, Scarpa M, Vescovi AL, De Filippis L. Glial degeneration with oxidative damage drives neuronal demise in MPSII disease. Cell Death Dis 2016; 7:e2331. [PMID: 27512952 PMCID: PMC5108318 DOI: 10.1038/cddis.2016.231] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Revised: 06/22/2016] [Accepted: 07/04/2016] [Indexed: 12/13/2022]
Abstract
Mucopolysaccharidosis type II (MPSII) is a lysosomal storage disorder due to the deficit of the iduronate 2-sulfatase (IDS) enzyme, causing progressive neurodegeneration in patients. Neural stem cells (NSCs) derived from the IDS-ko mouse can recapitulate MPSII pathogenesis in vitro. In differentiating IDS-ko NSCs and in the aging IDS-ko mouse brain, glial degeneration precedes neuronal degeneration. Here we show that pure IDS-ko NSC-derived astrocytes are selectively able to drive neuronal degeneration when cocultured with healthy neurons. This phenotype suggests concurrent oxidative damage with metabolic dysfunction. Similar patterns were observed in murine IDS-ko animals and in human MPSII brains. Most importantly, the mutant phenotype of IDS-ko astrocytes was reversed by low oxygen conditions and treatment with vitamin E, which also reversed the toxic effect on cocultured neurons. Moreover, at very early stages of disease we detected in vivo the development of a neuroinflammatory background that precedes astroglial degeneration, thus suggesting a novel model of MPSII pathogenesis, with neuroinflammation preceding glial degeneration, which is finally followed by neuronal death. This hypothesis is also consistent with the progression of white matter abnormalities in MPSII patients. Our study represents a novel breakthrough in the elucidation of MPSII brain pathogenesis and suggests the antioxidant molecules as potential therapeutic tools to delay MPSII onset and progression.
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Affiliation(s)
- Cristina Zalfa
- Department of Biotechnology and Biosciences, University Milan Bicocca, Piazza della Scienza 2, Milano 20126, Italy
| | - Chiara Verpelli
- CNR Neuroscience Institute and Department of Biotechnology and Translational Medicine, University of Milan, Via Vanvitelli 32, Milano 20129, Italy
| | - Francesca D'Avanzo
- Laboratory of Diagnosis and Therapy of Lysosomal Disorders, Department of Women's and Children's Health, University of Padova, Via Giustiniani 3, Padova 35128, Italy
| | - Rosella Tomanin
- Laboratory of Diagnosis and Therapy of Lysosomal Disorders, Department of Women's and Children's Health, University of Padova, Via Giustiniani 3, Padova 35128, Italy
| | - Cinzia Vicidomini
- CNR Neuroscience Institute and Department of Biotechnology and Translational Medicine, University of Milan, Via Vanvitelli 32, Milano 20129, Italy
| | | | - Renzo Manara
- Department of Neuroradiology, University of Salerno, Via S Allende, Baronissi 84081, Italy
| | - Carlo Sala
- CNR Neuroscience Institute and Department of Biotechnology and Translational Medicine, University of Milan, Via Vanvitelli 32, Milano 20129, Italy
| | - Maurizio Scarpa
- Laboratory of Diagnosis and Therapy of Lysosomal Disorders, Department of Women's and Children's Health, University of Padova, Via Giustiniani 3, Padova 35128, Italy
| | - Angelo Luigi Vescovi
- Department of Biotechnology and Biosciences, University Milan Bicocca, Piazza della Scienza 2, Milano 20126, Italy.,Stemgen Srl, Viale Ca' Granda, Milano, Italy.,Stem Cells Laboratory, Cell Factory and Biobank, Azienda Ospedaliera 'Santa Maria', Viale Tristano da Joannuccio 1, Terni 05100, Italy.,Casa Sollievo della Sofferenza, Viale Cappuccini 2, San Giovanni Rotondo (FG) 71013, Italy
| | - Lidia De Filippis
- Department of Biotechnology and Biosciences, University Milan Bicocca, Piazza della Scienza 2, Milano 20126, Italy.,Casa Sollievo della Sofferenza, Viale Cappuccini 2, San Giovanni Rotondo (FG) 71013, Italy
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748
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Lee DG, Park J, Lee HS, Lee SR, Lee DS. Iron overload-induced calcium signals modulate mitochondrial fragmentation in HT-22 hippocampal neuron cells. Toxicology 2016; 365:17-24. [PMID: 27481217 DOI: 10.1016/j.tox.2016.07.022] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Revised: 07/11/2016] [Accepted: 07/27/2016] [Indexed: 01/20/2023]
Abstract
Iron is necessary for neuronal functions; however, excessive iron accumulation caused by impairment of iron balance could damage neurons. Neuronal iron accumulation has been observed in several neurodegenerative diseases, such as Alzheimer's disease and Parkinson's disease. Nevertheless, the precise mechanisms underlying iron toxicity in neuron cells are not fully understood. In this study, we investigated the mechanism underlying iron overload-induced mitochondrial fragmentation in HT-22 hippocampal neuron cells that were incubated with ferric ammonium citrate (FAC). Mitochondrial fragmentation via dephosphorylation of Drp1 (Ser637) and increased apoptotic neuronal death were observed in FAC-stimulated HT-22 cells. Furthermore, the levels of intracellular calcium (Ca(2+)) were increased by iron overload. Notably, chelation of intracellular Ca(2+) rescued mitochondrial fragmentation and neuronal cell death. In addition, iron overload activated calcineurin through the Ca(2+)/calmodulin and Ca(2+)/calpain pathways. Pretreatment with the calmodulin inhibitor W13 and the calpain inhibitor ALLN attenuated iron overload-induced mitochondrial fragmentation and neuronal cell death. Therefore, these findings suggest that Ca(2+)-mediated calcineurin signals are a key player in iron-induced neurotoxicity by regulating mitochondrial dynamics. We believe that our results may contribute to the development of novel therapies for iron toxicity related neurodegenerative disorders.
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Affiliation(s)
- Dong Gil Lee
- School of Life Sciences, BK21 Plus KNU Creative BioResearch Group, Kyungpook National University, Daegu, Republic of Korea
| | - Junghyung Park
- School of Life Sciences, BK21 Plus KNU Creative BioResearch Group, Kyungpook National University, Daegu, Republic of Korea
| | - Hyun-Shik Lee
- School of Life Sciences, BK21 Plus KNU Creative BioResearch Group, Kyungpook National University, Daegu, Republic of Korea
| | - Sang-Rae Lee
- National Primate Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Chungcheonbuk-do, Republic of Korea
| | - Dong-Seok Lee
- School of Life Sciences, BK21 Plus KNU Creative BioResearch Group, Kyungpook National University, Daegu, Republic of Korea.
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749
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Neuroprotective hypothermia - Why keep your head cool during ischemia and reperfusion. Biochim Biophys Acta Gen Subj 2016; 1860:2521-2528. [PMID: 27475000 DOI: 10.1016/j.bbagen.2016.07.024] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Revised: 06/28/2016] [Accepted: 07/25/2016] [Indexed: 12/20/2022]
Abstract
BACKGROUND Targeted temperature management (TTM) is the induced cooling of the entire body or specific organs to help prevent ischemia and reperfusion (I/R) injury, as may occur during major surgery, cardiac resuscitation, traumatic brain injury and stroke. Ischemia and reperfusion induce neuronal damage by mitochondrial dysfunction and oxidative injury, ER stress, neuronal excitotoxicity, and a neuroinflammatory response, which may lead to activation of apoptosis pathways. SCOPE OF REVIEW The aim of the current review is to discuss TTM targets that convey neuroprotection and to identify potential novel pharmacological intervention strategies for the prevention of cerebral ischemia and reperfusion injury. MAJOR CONCLUSIONS TTM precludes I/R injury by reducing glutamate release and oxidative stress and inhibiting release of pro-inflammatory factors and thereby counteracts mitochondrial induced apoptosis, neuronal excitotoxicity, and neuroinflammation. Moreover, TTM promotes regulation of the unfolded protein response and induces SUMOylation and the production of cold shock proteins. These advantageous effects of TTM seem to depend on the clinical setting, as well as type and extent of the injury. Therefore, future aims should be to refine hypothermia management in order to optimize TTM utilization and to search for pharmacological agents mimicking the cellular effects of TTM. GENERAL SIGNIFICANCE Bundling knowledge about TTM in the experimental, translational and clinical setting may result in better approaches for diminishing I/R damage. While application of TTM in the clinical setting has some disadvantages, targeting its putative protective pathways may be useful to prevent I/R injury and reduce neurological complications.
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750
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McLelland GL, Lee SA, McBride HM, Fon EA. Syntaxin-17 delivers PINK1/parkin-dependent mitochondrial vesicles to the endolysosomal system. J Cell Biol 2016; 214:275-91. [PMID: 27458136 PMCID: PMC4970327 DOI: 10.1083/jcb.201603105] [Citation(s) in RCA: 171] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Accepted: 06/21/2016] [Indexed: 12/14/2022] Open
Abstract
Vesicular transport from mitochondria to lysosomes is an emerging mitochondrial quality control mechanism. Here, McLelland et al. identify how mitochondrial vesicles are targeted for degradation, showing that syntaxin-17 is recruited to these structures to govern their SNARE-dependent fusion with endolysosomes. Mitochondria are considered autonomous organelles, physically separated from endocytic and biosynthetic pathways. However, recent work uncovered a PINK1/parkin-dependent vesicle transport pathway wherein oxidized or damaged mitochondrial content are selectively delivered to the late endosome/lysosome for degradation, providing evidence that mitochondria are indeed integrated within the endomembrane system. Given that mitochondria have not been shown to use canonical soluble NSF attachment protein receptor (SNARE) machinery for fusion, the mechanism by which mitochondrial-derived vesicles (MDVs) are targeted to the endosomal compartment has remained unclear. In this study, we identify syntaxin-17 as a core mitochondrial SNARE required for the delivery of stress-induced PINK1/parkin-dependent MDVs to the late endosome/lysosome. Syntaxin-17 remains associated with mature MDVs and forms a ternary SNARE complex with SNAP29 and VAMP7 to mediate MDV–endolysosome fusion in a manner dependent on the homotypic fusion and vacuole protein sorting (HOPS) tethering complex. Syntaxin-17 can be traced to the last eukaryotic common ancestor, hinting that the removal of damaged mitochondrial content may represent one of the earliest vesicle transport routes in the cell.
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Affiliation(s)
- Gian-Luca McLelland
- McGill Parkinson Program, Montreal Neurological Institute, McGill University, Montreal, Quebec H3A 2B4, Canada Neurodegenerative Diseases Group, Montreal Neurological Institute, McGill University, Montreal, Quebec H3A 2B4, Canada
| | - Sydney A Lee
- McGill Parkinson Program, Montreal Neurological Institute, McGill University, Montreal, Quebec H3A 2B4, Canada Neurodegenerative Diseases Group, Montreal Neurological Institute, McGill University, Montreal, Quebec H3A 2B4, Canada
| | - Heidi M McBride
- Rare Diseases Group, Montreal Neurological Institute, McGill University, Montreal, Quebec H3A 2B4, Canada
| | - Edward A Fon
- McGill Parkinson Program, Montreal Neurological Institute, McGill University, Montreal, Quebec H3A 2B4, Canada Neurodegenerative Diseases Group, Montreal Neurological Institute, McGill University, Montreal, Quebec H3A 2B4, Canada
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