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Gureev AP, Alimova AA, Silachev DN, Plotnikov EY. Noncoupled Mitochondrial Respiration as Therapeutic Approach for the Treatment of Metabolic Diseases: Focus on Transgenic Animal Models. Int J Mol Sci 2023; 24:16491. [PMID: 38003681 PMCID: PMC10671337 DOI: 10.3390/ijms242216491] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 11/09/2023] [Accepted: 11/10/2023] [Indexed: 11/26/2023] Open
Abstract
Mitochondrial dysfunction contributes to numerous chronic diseases, and mitochondria are targets for various toxins and xenobiotics. Therefore, the development of drugs or therapeutic strategies targeting mitochondria is an important task in modern medicine. It is well known that the primary, although not the sole, function of mitochondria is ATP generation, which is achieved by coupled respiration. However, a high membrane potential can lead to uncontrolled reactive oxygen species (ROS) production and associated dysfunction. For over 50 years, scientists have been studying various synthetic uncouplers, and for more than 30 years, uncoupling proteins that are responsible for uncoupled respiration in mitochondria. Additionally, the proteins of the mitochondrial alternative respiratory pathway exist in plant mitochondria, allowing noncoupled respiration, in which electron flow is not associated with membrane potential formation. Over the past two decades, advances in genetic engineering have facilitated the creation of various cellular and animal models that simulate the effects of uncoupled and noncoupled respiration in different tissues under various disease conditions. In this review, we summarize and discuss the findings obtained from these transgenic models. We focus on the advantages and limitations of transgenic organisms, the observed physiological and biochemical changes, and the therapeutic potential of uncoupled and noncoupled respiration.
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Affiliation(s)
- Artem P. Gureev
- Department of Genetics, Cytology and Bioengineering, Voronezh State University, 394018 Voronezh, Russia; (A.P.G.); (A.A.A.)
- Laboratory of Metagenomics and Food Biotechnology, Voronezh State University of Engineering Technologies, 394036 Voronezh, Russia
| | - Alina A. Alimova
- Department of Genetics, Cytology and Bioengineering, Voronezh State University, 394018 Voronezh, Russia; (A.P.G.); (A.A.A.)
- Laboratory of Metagenomics and Food Biotechnology, Voronezh State University of Engineering Technologies, 394036 Voronezh, Russia
| | - Denis N. Silachev
- A.N. Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, 119234 Moscow, Russia;
| | - Egor Y. Plotnikov
- A.N. Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, 119234 Moscow, Russia;
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2
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Vila-Sanjurjo A, Mallo N, Atkins JF, Elson JL, Smith PM. Our current understanding of the toxicity of altered mito-ribosomal fidelity during mitochondrial protein synthesis: What can it tell us about human disease? Front Physiol 2023; 14:1082953. [PMID: 37457031 PMCID: PMC10349377 DOI: 10.3389/fphys.2023.1082953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Accepted: 02/28/2023] [Indexed: 07/18/2023] Open
Abstract
Altered mito-ribosomal fidelity is an important and insufficiently understood causative agent of mitochondrial dysfunction. Its pathogenic effects are particularly well-known in the case of mitochondrially induced deafness, due to the existence of the, so called, ototoxic variants at positions 847C (m.1494C) and 908A (m.1555A) of 12S mitochondrial (mt-) rRNA. It was shown long ago that the deleterious effects of these variants could remain dormant until an external stimulus triggered their pathogenicity. Yet, the link from the fidelity defect at the mito-ribosomal level to its phenotypic manifestation remained obscure. Recent work with fidelity-impaired mito-ribosomes, carrying error-prone and hyper-accurate mutations in mito-ribosomal proteins, have started to reveal the complexities of the phenotypic manifestation of mito-ribosomal fidelity defects, leading to a new understanding of mtDNA disease. While much needs to be done to arrive to a clear picture of how defects at the level of mito-ribosomal translation eventually result in the complex patterns of disease observed in patients, the current evidence indicates that altered mito-ribosome function, even at very low levels, may become highly pathogenic. The aims of this review are three-fold. First, we compare the molecular details associated with mito-ribosomal fidelity to those of general ribosomal fidelity. Second, we gather information on the cellular and organismal phenotypes associated with defective translational fidelity in order to provide the necessary grounds for an understanding of the phenotypic manifestation of defective mito-ribosomal fidelity. Finally, the results of recent experiments directly tackling mito-ribosomal fidelity are reviewed and future paths of investigation are discussed.
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Affiliation(s)
- Antón Vila-Sanjurjo
- Grupo GIBE, Departamento de Bioloxía e Centro de Investigacións Científicas Avanzadas (CICA), Universidade da Coruña (UDC), A Coruña, Spain
| | - Natalia Mallo
- Grupo GIBE, Departamento de Bioloxía e Centro de Investigacións Científicas Avanzadas (CICA), Universidade da Coruña (UDC), A Coruña, Spain
| | - John F Atkins
- Schools of Biochemistry and Microbiology, University College Cork, Cork, Ireland
| | - Joanna L Elson
- The Bioscience Institute, Newcastle University, Newcastle uponTyne, United Kingdom
- Human Metabolomics, North-West University, Potchefstroom, South Africa
| | - Paul M Smith
- Department of Paediatrics, Raigmore Hospital, Inverness, Scotland, United Kingdom
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3
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Xenotopic expression of alternative oxidase (AOX) to study mechanisms of mitochondrial disease. BIOCHIMICA ET BIOPHYSICA ACTA. BIOENERGETICS 2023; 1864:148947. [PMID: 36481273 DOI: 10.1016/j.bbabio.2022.148947] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Revised: 11/17/2022] [Accepted: 11/28/2022] [Indexed: 12/12/2022]
Abstract
The mitochondrial respiratory chain or electron transport chain (ETC) facilitates redox reactions which ultimately lead to the reduction of oxygen to water (respiration). Energy released by this process is used to establish a proton electrochemical gradient which drives ATP formation (oxidative phosphorylation, OXPHOS). It also plays an important role in vital processes beyond ATP formation and cellular metabolism, such as heat production, redox and ion homeostasis. Dysfunction of the ETC can thus impair cellular and organismal viability and is thought to be the underlying cause of a heterogeneous group of so-called mitochondrial diseases. Plants, yeasts, and many lower organisms, but not insects and vertebrates, possess an enzymatic mechanism that confers resistance to respiratory stress conditions, i.e., the alternative oxidase (AOX). Even in cells that naturally lack AOX, it is autonomously imported into the mitochondrial compartment upon xenotopic expression, where it refolds and becomes catalytically engaged when the cytochrome segment of the ETC is blocked. AOX was therefore proposed as a tool to study disease etiologies. To this end, AOX has been xenotopically expressed in mammalian cells and disease models of the fruit fly and mouse. Surprisingly, AOX showed remarkable rescue effects in some cases, whilst in others it had no effect or even exacerbated a condition. Here we summarize what has been learnt from the use of AOX in various disease models and discuss issues which still need to be addressed in order to understand the role of the ETC in health and disease.
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4
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Mitochondrial Neurodegeneration: Lessons from Drosophila melanogaster Models. Biomolecules 2023; 13:biom13020378. [PMID: 36830747 PMCID: PMC9953451 DOI: 10.3390/biom13020378] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Revised: 02/09/2023] [Accepted: 02/13/2023] [Indexed: 02/19/2023] Open
Abstract
The fruit fly-i.e., Drosophila melanogaster-has proven to be a very useful model for the understanding of basic physiological processes, such as development or ageing. The availability of straightforward genetic tools that can be used to produce engineered individuals makes this model extremely interesting for the understanding of the mechanisms underlying genetic diseases in physiological models. Mitochondrial diseases are a group of yet-incurable genetic disorders characterized by the malfunction of the oxidative phosphorylation system (OXPHOS), which is the highly conserved energy transformation system present in mitochondria. The generation of D. melanogaster models of mitochondrial disease started relatively recently but has already provided relevant information about the molecular mechanisms and pathological consequences of mitochondrial dysfunction. Here, we provide an overview of such models and highlight the relevance of D. melanogaster as a model to study mitochondrial disorders.
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5
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Anoar S, Woodling NS, Niccoli T. Mitochondria Dysfunction in Frontotemporal Dementia/Amyotrophic Lateral Sclerosis: Lessons From Drosophila Models. Front Neurosci 2021; 15:786076. [PMID: 34899176 PMCID: PMC8652125 DOI: 10.3389/fnins.2021.786076] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Accepted: 11/03/2021] [Indexed: 12/16/2022] Open
Abstract
Frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS) are neurodegenerative disorders characterized by declining motor and cognitive functions. Even though these diseases present with distinct sets of symptoms, FTD and ALS are two extremes of the same disease spectrum, as they show considerable overlap in genetic, clinical and neuropathological features. Among these overlapping features, mitochondrial dysfunction is associated with both FTD and ALS. Recent studies have shown that cells derived from patients' induced pluripotent stem cells (iPSC)s display mitochondrial abnormalities, and similar abnormalities have been observed in a number of animal disease models. Drosophila models have been widely used to study FTD and ALS because of their rapid generation time and extensive set of genetic tools. A wide array of fly models have been developed to elucidate the molecular mechanisms of toxicity for mutations associated with FTD/ALS. Fly models have been often instrumental in understanding the role of disease associated mutations in mitochondria biology. In this review, we discuss how mutations associated with FTD/ALS disrupt mitochondrial function, and we review how the use of Drosophila models has been pivotal to our current knowledge in this field.
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Affiliation(s)
- Sharifah Anoar
- Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, University College London, London, United Kingdom
| | - Nathaniel S Woodling
- Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, University College London, London, United Kingdom
| | - Teresa Niccoli
- Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, University College London, London, United Kingdom
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6
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Wang F, Zhang D, Zhang D, Li P, Gao Y. Mitochondrial Protein Translation: Emerging Roles and Clinical Significance in Disease. Front Cell Dev Biol 2021; 9:675465. [PMID: 34277617 PMCID: PMC8280776 DOI: 10.3389/fcell.2021.675465] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Accepted: 06/09/2021] [Indexed: 12/28/2022] Open
Abstract
Mitochondria are one of the most important organelles in cells. Mitochondria are semi-autonomous organelles with their own genetic system, and can independently replicate, transcribe, and translate mitochondrial DNA. Translation initiation, elongation, termination, and recycling of the ribosome are four stages in the process of mitochondrial protein translation. In this process, mitochondrial protein translation factors and translation activators, mitochondrial RNA, and other regulatory factors regulate mitochondrial protein translation. Mitochondrial protein translation abnormalities are associated with a variety of diseases, including cancer, cardiovascular diseases, and nervous system diseases. Mutation or deletion of various mitochondrial protein translation factors and translation activators leads to abnormal mitochondrial protein translation. Mitochondrial tRNAs and mitochondrial ribosomal proteins are essential players during translation and mutations in genes encoding them represent a large fraction of mitochondrial diseases. Moreover, there is crosstalk between mitochondrial protein translation and cytoplasmic translation, and the imbalance between mitochondrial protein translation and cytoplasmic translation can affect some physiological and pathological processes. This review summarizes the regulation of mitochondrial protein translation factors, mitochondrial ribosomal proteins, mitochondrial tRNAs, and mitochondrial aminoacyl-tRNA synthetases (mt-aaRSs) in the mitochondrial protein translation process and its relationship with diseases. The regulation of mitochondrial protein translation and cytoplasmic translation in multiple diseases is also summarized.
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Affiliation(s)
- Fei Wang
- Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao, China
| | - Deyu Zhang
- Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao, China
| | - Dejiu Zhang
- Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao, China
| | - Peifeng Li
- Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao, China
| | - Yanyan Gao
- Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao, China.,Key Laboratory of Nuclear Medicine, Ministry of Health, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi, China
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7
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Jacobs HT, George J, Kemppainen E. Regulation of growth in Drosophila melanogaster: the roles of mitochondrial metabolism. J Biochem 2020; 167:267-277. [PMID: 31926002 PMCID: PMC7048069 DOI: 10.1093/jb/mvaa002] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2019] [Accepted: 01/05/2020] [Indexed: 12/14/2022] Open
Abstract
Mitochondrial functions are often considered purely from the standpoint of catabolism, but in growing cells they are mainly dedicated to anabolic processes, and can have a profound impact on the rate of growth. The Drosophila larva, which increases in body mass ∼200-fold over the course of ∼3 days at 25°C, provides an excellent model to study the underlying regulatory machinery that connects mitochondrial metabolic capacity to growth. In this review, we will focus on several key aspects of this machinery: nutrient sensing, endocrine control of feeding and nutrient mobilization, metabolic signalling, protein synthesis regulation and pathways of steroid biosynthesis and activity. In all these aspects, mitochondria appear to play a crucial role.
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Affiliation(s)
- Howard T Jacobs
- Faculty of Medicine and Health Technology, FI-33014 Tampere University, Finland
| | - Jack George
- Faculty of Medicine and Health Technology, FI-33014 Tampere University, Finland
| | - Esko Kemppainen
- Faculty of Medicine and Health Technology, FI-33014 Tampere University, Finland
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8
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Salminen TS, Vale PF. Drosophila as a Model System to Investigate the Effects of Mitochondrial Variation on Innate Immunity. Front Immunol 2020; 11:521. [PMID: 32269576 PMCID: PMC7109263 DOI: 10.3389/fimmu.2020.00521] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 03/06/2020] [Indexed: 12/14/2022] Open
Abstract
Understanding why the response to infection varies between individuals remains one of the major challenges in immunology and infection biology. A substantial proportion of this heterogeneity can be explained by individual genetic differences which result in variable immune responses, and there are many examples of polymorphisms in nuclear-encoded genes that alter immunocompetence. However, how immunity is affected by genetic polymorphism in an additional genome, inherited maternally inside mitochondria (mtDNA), has been relatively understudied. Mitochondria are increasingly recognized as important mediators of innate immune responses, not only because they are the main source of energy required for costly immune responses, but also because by-products of mitochondrial metabolism, such as reactive oxygen species (ROS), may have direct microbicidal action. Yet, it is currently unclear how naturally occurring variation in mtDNA contributes to heterogeneity in infection outcomes. In this review article, we describe potential sources of variation in mitochondrial function that may arise due to mutations in vital nuclear and mitochondrial components of energy production or due to a disruption in mito-nuclear crosstalk. We then highlight how these changes in mitochondrial function can impact immune responses, focusing on their effects on ATP- and ROS-generating pathways, as well as immune signaling. Finally, we outline how being a powerful and genetically tractable model of infection, immunity and mitochondrial genetics makes the fruit fly Drosophila melanogaster ideally suited to dissect mitochondrial effects on innate immune responses to infection.
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Affiliation(s)
- Tiina S. Salminen
- School of Biological Sciences, Institute of Evolutionary Biology, The University of Edinburgh, Edinburgh, United Kingdom
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - Pedro F. Vale
- School of Biological Sciences, Institute of Evolutionary Biology, The University of Edinburgh, Edinburgh, United Kingdom
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9
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Wang Z, Li J, Long X, Jiao L, Zhou M, Wu K. MRPS16 facilitates tumor progression via the PI3K/AKT/Snail signaling axis. J Cancer 2020; 11:2032-2043. [PMID: 32127931 PMCID: PMC7052926 DOI: 10.7150/jca.39671] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Accepted: 01/04/2020] [Indexed: 02/07/2023] Open
Abstract
Background: Although aberrant expression of MRPS16 (mitochondrial ribosomal protein S16) contributes to biological dysfunction, especially mitochondrial translation defects, the status of MRPS16 and its correlation with prognosis in tumors, especially glioma, which is a common, morbid and frequently lethal malignancy, are still controversial. Methods: Herein, we used high-throughput sequencing to identify the target molecule MRPS16. Subsequently, we detected MRPS16 protein and mRNA expression levels in normal brain tissue (NBT) and different grades of glioma tissue. The molecular effects of MRPS16 in glioma cells were tested by Western blotting, quantitative polymerase chain reaction (qRT-PCR), EdU, CCK-8, colony formation, Transwell migration and invasion assays. Results: Intriguingly, we found that MRPS16 knockdown suppressed tumor cell growth, migration and invasion. Conversely, MRPS16 over-expression increased tumor cell growth, migration and invasion. In addition, subsequent mechanistic studies indicated that MRPS16 promoted glioma cell growth, migration and invasion by the activating PI3K/AKT/Snail axis. Furthermore, we observed that the decrease in tumor cell growth, migration, invasion and Snail expression mediated by MRPS16 knockdown could be rescued by Snail over-expression. Conclusion: In short, our data demonstrate that MRPS16 over-expression remarkably promotes tumor cell growth, migration and invasion via the PI3K/AKT/Snail axis, which may be a promising prognostic marker for glioma.
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Affiliation(s)
- Zhen Wang
- Department of Neurosurgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Jiefang Street, Wuhan 430030, P.R. China
| | - Junjun Li
- Department of Neurosurgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Jiefang Street, Wuhan 430022, P.R. China
| | - Xiaobing Long
- Department of Neurosurgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Jiefang Street, Wuhan 430030, P.R. China
| | - Liwu Jiao
- Department of Neurosurgery, The First People Hospital of Qujing, Qujing 655000, P.R. China
| | - Minghui Zhou
- Department of Neurosurgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Jiefang Street, Wuhan 430030, P.R. China
| | - Kang Wu
- Department of Neurosurgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Jiefang Street, Wuhan 430030, P.R. China
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George J, Tuomela T, Kemppainen E, Nurminen A, Braun S, Yalgin C, Jacobs HT. Mitochondrial dysfunction generates a growth-restraining signal linked to pyruvate in Drosophila larvae. Fly (Austin) 2019; 13:12-28. [PMID: 31526131 PMCID: PMC6988875 DOI: 10.1080/19336934.2019.1662266] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The Drosophila bang-sensitive mutant tko25t, manifesting a global deficiency in oxidative phosphorylation due to a mitochondrial protein synthesis defect, exhibits a pronounced delay in larval development. We previously identified a number of metabolic abnormalities in tko25t larvae, including elevated pyruvate and lactate, and found the larval gut to be a crucial tissue for the regulation of larval growth in the mutant. Here we established that expression of wild-type tko in any of several other tissues of tko25t also partially alleviates developmental delay. The effects appeared to be additive, whilst knockdown of tko in a variety of specific tissues phenocopied tko25t, producing developmental delay and bang-sensitivity. These findings imply the existence of a systemic signal regulating growth in response to mitochondrial dysfunction. Drugs and RNAi-targeted on pyruvate metabolism interacted with tko25t in ways that implicated pyruvate or one of its metabolic derivatives in playing a central role in generating such a signal. RNA-seq revealed that dietary pyruvate-induced changes in transcript representation were mostly non-coherent with those produced by tko25t or high-sugar, consistent with the idea that growth regulation operates primarily at the translational and/or metabolic level.
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Affiliation(s)
- Jack George
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - Tea Tuomela
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - Esko Kemppainen
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - Antti Nurminen
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - Samuel Braun
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - Cagri Yalgin
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland.,Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Howard T Jacobs
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland.,Institute of Biotechnology, University of Helsinki, Helsinki, Finland
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11
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Groove structure of porous hydroxyapatite scaffolds (HAS) modulates immune environment via regulating macrophages and subsequently enhances osteogenesis. J Biol Inorg Chem 2019; 24:733-745. [DOI: 10.1007/s00775-019-01687-w] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Accepted: 06/27/2019] [Indexed: 12/14/2022]
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12
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George J, Jacobs HT. Minimal effects of spargel (PGC-1) overexpression in a Drosophila mitochondrial disease model. Biol Open 2019; 8:bio.042135. [PMID: 31292108 PMCID: PMC6679408 DOI: 10.1242/bio.042135] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
PGC-1α and its homologues have been proposed to act as master regulators of mitochondrial biogenesis in animals. Most relevant studies have been conducted in mammals, where interpretation is complicated by the fact that there are three partially redundant members of the gene family. In Drosophila, only a single PGC-1 homologue, spargel (srl), is present in the genome. Here, we analyzed the effects of srl overexpression on phenotype and on gene expression in tko25t, a recessive bang-sensitive mutant with a global defect in oxidative phosphorylation, resulting from a deficiency of mitochondrial protein synthesis. In contrast to previous reports, we found that substantial overexpression of srl throughout development had only minimal effects on the tko25t mutant phenotype. Copy number of mtDNA was unaltered and srl overexpression produced no systematic effects on a representative set of transcripts related to mitochondrial OXPHOS and other metabolic enzymes, although these were influenced by sex and genetic background. This study provides no support to the concept of Spargel as a global regulator of mitochondrial biogenesis, at least in the context of the tko25t model. Summary: Overexpression of spargel, the fly PGC-1 homologue proposed as a mitochondrial biogenesis regulator, has minimal effects on the phenotype of tko25t, considered a fly model for mitochondrial disease.
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Affiliation(s)
- Jack George
- Faculty of Medicine and Health Technology, FI-33014 Tampere University, Finland
| | - Howard T Jacobs
- Faculty of Medicine and Health Technology, FI-33014 Tampere University, Finland
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13
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Lethal Interaction of Nuclear and Mitochondrial Genotypes in Drosophila melanogaster. G3-GENES GENOMES GENETICS 2019; 9:2225-2234. [PMID: 31076384 PMCID: PMC6643882 DOI: 10.1534/g3.119.400315] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Drosophilamelanogaster, like most animal species, displays considerable genetic variation in both nuclear and mitochondrial DNA (mtDNA). Here we tested whether any of four natural mtDNA variants was able to modify the effect of the phenotypically mild, nuclear tko25t mutation, affecting mitochondrial protein synthesis. When combined with tko25t, the mtDNA from wild strain KSA2 produced pupal lethality, accompanied by the presence of melanotic nodules in L3 larvae. KSA2 mtDNA, which carries a substitution at a conserved residue of cytochrome b that is predicted to be involved in subunit interactions within respiratory complex III, conferred drastically decreased respiratory capacity and complex III activity in the tko25t but not a wild-type nuclear background. The complex III inhibitor antimycin A was able to phenocopy effects of the tko25t mutation in the KSA2 mtDNA background. This is the first report of a lethal, nuclear-mitochondrial interaction within a metazoan species, representing a paradigm for understanding genetic interactions between nuclear and mitochondrial genotype relevant to human health and disease.
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14
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Chen Z, Zhang F, Xu H. Human mitochondrial DNA diseases and Drosophila models. J Genet Genomics 2019; 46:201-212. [DOI: 10.1016/j.jgg.2019.03.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Revised: 03/05/2019] [Accepted: 03/25/2019] [Indexed: 01/06/2023]
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15
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Oberhofer G, Ivy T, Hay BA. Cleave and Rescue, a novel selfish genetic element and general strategy for gene drive. Proc Natl Acad Sci U S A 2019; 116:6250-6259. [PMID: 30760597 PMCID: PMC6442612 DOI: 10.1073/pnas.1816928116] [Citation(s) in RCA: 84] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
There is great interest in being able to spread beneficial traits throughout wild populations in ways that are self-sustaining. Here, we describe a chromosomal selfish genetic element, CleaveR [Cleave and Rescue (ClvR)], able to achieve this goal. ClvR comprises two linked chromosomal components. One, germline-expressed Cas9 and guide RNAs (gRNAs)-the Cleaver-cleaves and thereby disrupts endogenous copies of a gene whose product is essential. The other, a recoded version of the essential gene resistant to cleavage and gene conversion with cleaved copies-the Rescue-provides essential gene function. ClvR enhances its transmission, and that of linked genes, by creating conditions in which progeny lacking ClvR die because they have no functional copies of the essential gene. In contrast, those who inherit ClvR survive, resulting in an increase in ClvR frequency. ClvR is predicted to spread to fixation under diverse conditions. To test these predictions, we generated a ClvR element in Drosophila melanogasterClvRtko is located on chromosome 3 and uses Cas9 and four gRNAs to disrupt melanogaster technical knockout (tko), an X-linked essential gene. Rescue activity is provided by tko from Drosophila virilisClvRtko results in germline and maternal carryover-dependent inactivation of melanogaster tko (>99% per generation); lethality caused by this loss is rescued by the virilis transgene; ClvRtko activities are robust to genetic diversity in strains from five continents; and uncleavable but functional melanogaster tko alleles were not observed. Finally, ClvRtko spreads to transgene fixation. The simplicity of ClvR suggests it may be useful for altering populations in diverse species.
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Affiliation(s)
- Georg Oberhofer
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125
| | - Tobin Ivy
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125
| | - Bruce A Hay
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125
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16
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Reynolds ER. Shortened Lifespan and Other Age-Related Defects in Bang Sensitive Mutants of Drosophila melanogaster. G3 (BETHESDA, MD.) 2018; 8:3953-3960. [PMID: 30355763 PMCID: PMC6288826 DOI: 10.1534/g3.118.200610] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Accepted: 10/18/2018] [Indexed: 11/28/2022]
Abstract
Mitochondrial diseases are complex disorders that exhibit their primary effects in energetically active tissues. Damage generated by mitochondria is also thought to be a key component of aging and age-related disease. An important model for mitochondrial dysfunction is the bang sensitive (bs) mutants in Drosophila melanogaster Although these mutants all show a striking seizure phenotype, several bs mutants have gene products that are involved with mitochondrial function, while others affect excitability another way. All of the bs mutants (parabss , eas, jus, ses B, tko are examined here) paralyze and seize upon challenge with a sensory stimulus, most notably mechanical stimulation. These and other excitability mutants have been linked to neurodegeneration with age. In addition to these phenotypes, we have found age-related defects for several of the bs strains. The mutants eas, ses B, and tko display shortened lifespan, an increased mean recovery time from seizure with age, and decreased climbing ability over lifespan as compared to isogenic CS or w1118 lines. Other mutants show a subset of these defects. The age-related phenotypes can be rescued by feeding melatonin, an antioxidant, in all the mutants except ses B The age-related defects do not appear to be correlated with the seizure phenotype. Inducing seizures on a daily basis did not exacerbate the phenotypes and treatment with antiepileptic drugs did not increase lifespan. The results suggest that the excitability phenotypes and the age-related phenotypes may be somewhat independent and that these phenotypes mutants may arise from impacts on different pathways.
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Rodrigues APC, Camargo AF, Andjelković A, Jacobs HT, Oliveira MT. Developmental arrest in Drosophila melanogaster caused by mitochondrial DNA replication defects cannot be rescued by the alternative oxidase. Sci Rep 2018; 8:10882. [PMID: 30022066 PMCID: PMC6052043 DOI: 10.1038/s41598-018-29150-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Accepted: 06/14/2018] [Indexed: 12/22/2022] Open
Abstract
The xenotopic expression of the alternative oxidase AOX from the tunicate Ciona intestinalis in diverse models of human disease partially alleviates the phenotypic effects of mitochondrial respiratory chain defects. AOX is a non-proton pumping, mitochondrial inner membrane-bound, single-subunit enzyme that can bypass electron transport through the cytochrome segment, providing an additional site for ubiquinone reoxidation and oxygen reduction upon respiratory chain overload. We set out to investigate whether AOX expression in Drosophila could counteract the effects of mitochondrial DNA (mtDNA) replication defects caused by disturbances in the mtDNA helicase or DNA polymerase γ. We observed that the developmental arrest imposed by either the expression of mutant forms of these enzymes or their knockdown was not rescued by AOX. Considering also the inability of AOX to ameliorate the phenotype of tko25t, a fly mutant with mitochondrial translation deficiency, we infer that this alternative enzyme may not be applicable to cases of mitochondrial gene expression defects. Finding the limitations of AOX applicability will help establish the parameters for the future putative use of this enzyme in gene therapies for human mitochondrial diseases.
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Affiliation(s)
- Ana Paula C Rodrigues
- Departamento de Tecnologia, Faculdade de Ciências Agrárias e Veterinárias, Universidade Estadual Paulista "Júlio de Mesquita Filho", 14884-900, Jaboticabal, SP, Brazil
| | - André F Camargo
- Departamento de Tecnologia, Faculdade de Ciências Agrárias e Veterinárias, Universidade Estadual Paulista "Júlio de Mesquita Filho", 14884-900, Jaboticabal, SP, Brazil
| | - Ana Andjelković
- Faculty of Medicine and Life Sciences and Tampere University Hospital, University of Tampere, Tampere, FI-33014, Finland.,Institute of Biotechnology, University of Helsinki, Helsinki, FI-00014, Finland
| | - Howard T Jacobs
- Faculty of Medicine and Life Sciences and Tampere University Hospital, University of Tampere, Tampere, FI-33014, Finland.,Institute of Biotechnology, University of Helsinki, Helsinki, FI-00014, Finland
| | - Marcos T Oliveira
- Departamento de Tecnologia, Faculdade de Ciências Agrárias e Veterinárias, Universidade Estadual Paulista "Júlio de Mesquita Filho", 14884-900, Jaboticabal, SP, Brazil.
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Kuszak AJ, Espey MG, Falk MJ, Holmbeck MA, Manfredi G, Shadel GS, Vernon HJ, Zolkipli-Cunningham Z. Nutritional Interventions for Mitochondrial OXPHOS Deficiencies: Mechanisms and Model Systems. ANNUAL REVIEW OF PATHOLOGY 2018; 13:163-191. [PMID: 29099651 PMCID: PMC5911915 DOI: 10.1146/annurev-pathol-020117-043644] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Multisystem metabolic disorders caused by defects in oxidative phosphorylation (OXPHOS) are severe, often lethal, conditions. Inborn errors of OXPHOS function are termed primary mitochondrial disorders (PMDs), and the use of nutritional interventions is routine in their supportive management. However, detailed mechanistic understanding and evidence for efficacy and safety of these interventions are limited. Preclinical cellular and animal model systems are important tools to investigate PMD metabolic mechanisms and therapeutic strategies. This review assesses the mechanistic rationale and experimental evidence for nutritional interventions commonly used in PMDs, including micronutrients, metabolic agents, signaling modifiers, and dietary regulation, while highlighting important knowledge gaps and impediments for randomized controlled trials. Cellular and animal model systems that recapitulate mutations and clinical manifestations of specific PMDs are evaluated for their potential in determining pathological mechanisms, elucidating therapeutic health outcomes, and investigating the value of nutritional interventions for mitochondrial disease conditions.
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Affiliation(s)
- Adam J Kuszak
- Office of Dietary Supplements, National Institutes of Health, Bethesda, Maryland 20852, USA;
| | - Michael Graham Espey
- Division of Cancer Biology, National Cancer Institute, Rockville, Maryland 20850, USA;
| | - Marni J Falk
- Department of Pediatrics, Division of Human Genetics, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania 19104, USA;
- Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Marissa A Holmbeck
- Department of Pathology, Yale School of Medicine, New Haven, Connecticut 06510-8023, USA;
| | - Giovanni Manfredi
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY 10065, USA;
| | - Gerald S Shadel
- Department of Pathology, Yale School of Medicine, New Haven, Connecticut 06510-8023, USA;
- Department of Genetics, Yale School of Medicine, New Haven, Connecticut 06520-8023, USA;
| | - Hilary J Vernon
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University, Baltimore, Maryland 21205, USA;
| | - Zarazuela Zolkipli-Cunningham
- Department of Pediatrics, Division of Neurology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania 19104, USA;
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Hoenig M, Pannicke U, Gaspar HB, Schwarz K. Recent advances in understanding the pathogenesis and management of reticular dysgenesis. Br J Haematol 2017; 180:644-653. [PMID: 29270983 DOI: 10.1111/bjh.15045] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Reticular Dysgenesis is a rare immunodeficiency which is clinically characterized by the combination of Severe Combined Immunodeficiency (SCID) with agranulocytosis and sensorineural deafness. Mutations in the gene encoding adenylate kinase 2 (AK2) were identified to cause this phenotype. In this review, we will demonstrate important clinical differences between reticular dysgenesis and other SCID entities and summarize recent concepts in the understanding of the pathophysiology of the disease and the management strategies for this difficult condition.
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Affiliation(s)
- Manfred Hoenig
- Department of Paediatrics, University Medical Centre Ulm, Ulm, Germany
| | - Ulrich Pannicke
- Institute for Transfusion Medicine, University of Ulm, Ulm, Germany.,Institute for Clinical Transfusion Medicine and Immunogenetics Ulm, German Red Cross Blood Service Baden-Wuerttemberg, Hessen, Germany
| | - Hubert B Gaspar
- UCL Great Ormond Street Institute of Child Health and Great Ormond Street Hospital for Children NHS Trust, London, UK
| | - Klaus Schwarz
- Institute for Transfusion Medicine, University of Ulm, Ulm, Germany.,Institute for Clinical Transfusion Medicine and Immunogenetics Ulm, German Red Cross Blood Service Baden-Wuerttemberg, Hessen, Germany
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20
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Dean D, Weinstein H, Amin S, Karno B, McAvoy E, Hoy R, Recknagel A, Jarvis C, Deitcher D. Extending julius seizure, a bang-sensitive gene, as a model for studying epileptogenesis: Cold shock, and a new insertional mutation. Fly (Austin) 2017; 12:55-61. [PMID: 29125376 DOI: 10.1080/19336934.2017.1402993] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Abstract
The bang-sensitive (BS) mutants of Drosophila are an important model for studying epilepsy. We recently identified a novel BS locus, julius seizure (jus), encoding a protein containing two transmembrane domains and an extracellular cysteine-rich loop. We also determined that jussda iso7.8, a previously identified BS mutation, is an allele of jus by recombination, deficiency mapping, complementation testing, and genetic rescue. RNAi knockdown revealed that jus expression is important in cholinergic neurons and that the critical stage of jus expression is the mid-pupa. Finally, we found that a functional, GFP-tagged genomic construct of jus is expressed mostly in axons of the neck connectives and of the thoracic abdominal ganglia. In this Extra View article, we show that a MiMiC GFP-tagged Jus is localized to the same nervous system regions as the GFP-tagged genomic construct, but its expression is mostly confined to cell bodies and it causes bang-sensitivity. The MiMiC GFP-tag lies in the extracellular loop while the genomic construct is tagged at the C-terminus. This suggests that the alternate position of the GFP tag may disrupt Jus protein function by altering its subcellular localization and/or stability. We also show that a small subset of jus-expressing neurons are responsible for the BS phenotype. Finally, extending the utility of the BS seizure model, we show that jus mutants exhibit cold-sensitive paralysis and are partially sensitive to strobe-induced seizures.
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Affiliation(s)
- Derek Dean
- a Department of Biology , Williams College , Williamstown , MA USA
| | - Hannah Weinstein
- a Department of Biology , Williams College , Williamstown , MA USA
| | - Seema Amin
- a Department of Biology , Williams College , Williamstown , MA USA
| | - Breelyn Karno
- a Department of Biology , Williams College , Williamstown , MA USA
| | - Emma McAvoy
- a Department of Biology , Williams College , Williamstown , MA USA
| | - Ronald Hoy
- b Department of Neurobiology and Behavior , Cornell University , Ithaca , NY USA
| | - Andrew Recknagel
- b Department of Neurobiology and Behavior , Cornell University , Ithaca , NY USA
| | - Casey Jarvis
- b Department of Neurobiology and Behavior , Cornell University , Ithaca , NY USA
| | - David Deitcher
- b Department of Neurobiology and Behavior , Cornell University , Ithaca , NY USA
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21
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Mitochondrial genotype modulates mtDNA copy number and organismal phenotype in Drosophila. Mitochondrion 2017; 34:75-83. [DOI: 10.1016/j.mito.2017.02.001] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Revised: 11/28/2016] [Accepted: 02/01/2017] [Indexed: 11/21/2022]
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22
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eUnaG: a new ligand-inducible fluorescent reporter to detect drug transporter activity in live cells. Sci Rep 2017; 7:41619. [PMID: 28176814 PMCID: PMC5296874 DOI: 10.1038/srep41619] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Accepted: 12/22/2016] [Indexed: 01/18/2023] Open
Abstract
The absorption, distribution, metabolism and excretion (ADME) of metabolites and toxic organic solutes are orchestrated by the ATP-binding cassette (ABC) transporters and the organic solute carrier family (SLC) proteins. A large number of ABC and SLC transpoters exist; however, only a small number have been well characterized. To facilitate the analysis of these transporters, which is important for drug safety and physiological studies, we developed a sensitive genetically encoded bilirubin (BR)-inducible fluorescence sensor (eUnaG) to detect transporter-coupled influx/efflux of organic compounds. This sensor can be used in live cells to measure transporter activity, as excretion of BR depends on ABC and SLC transporters. Applying eUnaG in functional RNAi screens, we characterize l(2)03659 as a Drosophila multidrug resistant-associated ABC transporter.
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23
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Deficiency of succinyl-CoA synthetase α subunit delays development, impairs locomotor activity and reduces survival under starvation in Drosophila. Biochem Biophys Res Commun 2016; 483:566-571. [PMID: 28017724 DOI: 10.1016/j.bbrc.2016.12.105] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2016] [Accepted: 12/16/2016] [Indexed: 11/23/2022]
Abstract
Succinyl-CoA synthetase/ligase (SCS) is a mitochondrial enzyme that catalyzes the reversible process from succinyl-CoA to succinate and free coenzyme A in TCA cycle. SCS deficiencies are implicated in mitochondrial hepatoencephalomyopathy in humans. To investigate the impact of SCS deficiencies in Drosophila, we generated a null mutation in Scs alpha subunit (Scsα) using the CRISPR/Cas9 system, and characterized their phenotype. We found that the Drosophila SCS deficiency, designated ScsαKO, contained a high level of succinyl-CoA, a substrate for the enzyme, and altered levels of various metabolites in TCA cycle and glycolysis, indicating that the energy metabolism was impaired. Unlike SCSα deficiencies in humans, there was no reduction in lifespan, indicating that Scsα is not critical for viability in Drosophila. However, they showed developmental delays, locomotor activity defects, and reduced survival under starvation. We also found that glycogen breakdown occurred during development, suggesting that the mutant flies were unable to produce sufficient energy to promote normal growth. These results suggested that SCSα is essential for proper energy metabolism in Drosophila. The ScsαKO flies should be useful as a model to understand the physiological role of SCSα as well as the pathophysiology of SCSα deficiency.
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Ligand-Bound GeneSwitch Causes Developmental Aberrations in Drosophila that Are Alleviated by the Alternative Oxidase. G3-GENES GENOMES GENETICS 2016; 6:2839-46. [PMID: 27412986 PMCID: PMC5015941 DOI: 10.1534/g3.116.030882] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Culture of Drosophila expressing the steroid-dependent GeneSwitch transcriptional activator under the control of the ubiquitous α-tubulin promoter was found to produce extensive pupal lethality, as well as a range of dysmorphic adult phenotypes, in the presence of high concentrations of the inducing drug RU486. Prominent among these was cleft thorax, seen previously in flies bearing mutant alleles of the nuclear receptor Ultraspiracle and many other mutants, as well as notched wings, leg malformations, and bristle abnormalities. Neither the α-tubulin-GeneSwitch driver nor the inducing drug on their own produced any of these effects. A second GeneSwitch driver, under the control of the daughterless promoter, which gave much lower and more tissue-restricted transgene expression, exhibited only mild bristle abnormalities in the presence of high levels of RU486. Coexpression of the alternative oxidase (AOX) from Ciona intestinalis produced a substantial shift in the developmental outcome toward a wild-type phenotype, which was dependent on the AOX expression level. Neither an enzymatically inactivated variant of AOX, nor GFP, or the alternative NADH dehydrogenase Ndi1 from yeast gave any such rescue. Users of the GeneSwitch system should be aware of the potential confounding effects of its application in developmental studies.
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25
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Sen A, Cox RT. Fly Models of Human Diseases: Drosophila as a Model for Understanding Human Mitochondrial Mutations and Disease. Curr Top Dev Biol 2016; 121:1-27. [PMID: 28057297 DOI: 10.1016/bs.ctdb.2016.07.001] [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] [Indexed: 12/12/2022]
Abstract
Mitochondrial diseases are a prevalent, heterogeneous class of diseases caused by defects in oxidative phosphorylation, whose severity depends upon particular genetic mutations. These diseases can be difficult to diagnose, and current therapeutics have limited efficacy, primarily treating only symptoms. Because mitochondria play a pivotal role in numerous cellular functions, especially ATP production, their diminished activity has dramatic physiological consequences. While this in and of itself makes treating mitochondrial disease complex, these organelles contain their own DNA, mtDNA, whose products are required for ATP production, in addition to the hundreds of nucleus-encoded proteins. Drosophila offers a tractable whole-animal model to understand the mechanisms underlying loss of mitochondrial function, the subsequent cellular and tissue damage that results, and how these organelles are inherited. Human and Drosophila mtDNAs encode the same set of products, and the homologous nucleus-encoded genes required for mitochondrial function are conserved. In addition, Drosophila contain sufficiently complex organ systems to effectively recapitulate many basic symptoms of mitochondrial diseases, yet are relatively easy and fast to genetically manipulate. There are several Drosophila models for specific mitochondrial diseases, which have been recently reviewed (Foriel, Willems, Smeitink, Schenck, & Beyrath, 2015). In this review, we highlight the conservation between human and Drosophila mtDNA, the present and future techniques for creating mtDNA mutations for further study, and how Drosophila has contributed to our current understanding of mitochondrial inheritance.
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Affiliation(s)
- A Sen
- Uniformed Services University, Bethesda, MD, United States
| | - R T Cox
- Uniformed Services University, Bethesda, MD, United States.
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26
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Gopisetty G, Thangarajan R. Mammalian mitochondrial ribosomal small subunit (MRPS) genes: A putative role in human disease. Gene 2016; 589:27-35. [PMID: 27170550 DOI: 10.1016/j.gene.2016.05.008] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2016] [Accepted: 05/06/2016] [Indexed: 12/25/2022]
Abstract
Mitochondria are prominently understood as power houses producing ATP the primary energy currency of the cell. However, mitochondria are also known to play an important role in apoptosis and autophagy, and mitochondrial dysregulation can lead to pathological outcomes. Mitochondria are known to contain 1500 proteins of which only 13 are coded by mitochondrial DNA and the rest are coded by nuclear genes. Protein synthesis in mitochondria involves mitochondrial ribosomes which are 55-60S particles and are composed of small 28S and large 39S subunits. A feature of mammalian mitoribosome which differentiate it from bacterial ribosomes is the increased protein content. The human mitochondrial ribosomal protein (MRP) gene family comprises of 30 genes which code for mitochondrial ribosomal small subunit and 50 genes for the large subunit. The present review focuses on the mitochondrial ribosomal small subunit genes (MRPS), presents an overview of the literature and data gleaned from publicly available gene and protein expression databases. The survey revealed aberrations in MRPS gene expression patterns in varied human diseases indicating a putative role in their etiology.
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Affiliation(s)
- Gopal Gopisetty
- Department of Molecular Oncology, Cancer Institute (WIA), Chennai, India
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27
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Kemppainen E, George J, Garipler G, Tuomela T, Kiviranta E, Soga T, Dunn CD, Jacobs HT. Mitochondrial Dysfunction Plus High-Sugar Diet Provokes a Metabolic Crisis That Inhibits Growth. PLoS One 2016; 11:e0145836. [PMID: 26812173 PMCID: PMC4728084 DOI: 10.1371/journal.pone.0145836] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Accepted: 11/04/2015] [Indexed: 11/18/2022] Open
Abstract
The Drosophila mutant tko25t exhibits a deficiency of mitochondrial protein synthesis, leading to a global insufficiency of respiration and oxidative phosphorylation. This entrains an organismal phenotype of developmental delay and sensitivity to seizures induced by mechanical stress. We found that the mutant phenotype is exacerbated in a dose-dependent fashion by high dietary sugar levels. tko25t larvae were found to exhibit severe metabolic abnormalities that were further accentuated by high-sugar diet. These include elevated pyruvate and lactate, decreased ATP and NADPH. Dietary pyruvate or lactate supplementation phenocopied the effects of high sugar. Based on tissue-specific rescue, the crucial tissue in which this metabolic crisis initiates is the gut. It is accompanied by down-regulation of the apparatus of cytosolic protein synthesis and secretion at both the RNA and post-translational levels, including a novel regulation of S6 kinase at the protein level.
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Affiliation(s)
- Esko Kemppainen
- BioMediTech and Tampere University Hospital, FI-33014, University of Tampere, Tampere, Finland
| | - Jack George
- BioMediTech and Tampere University Hospital, FI-33014, University of Tampere, Tampere, Finland
| | - Görkem Garipler
- BioMediTech and Tampere University Hospital, FI-33014, University of Tampere, Tampere, Finland
- Department of Molecular Biology and Genetics, Koç University, Sariyer, Istanbul, 34450, Turkey
| | - Tea Tuomela
- BioMediTech and Tampere University Hospital, FI-33014, University of Tampere, Tampere, Finland
| | - Essi Kiviranta
- BioMediTech and Tampere University Hospital, FI-33014, University of Tampere, Tampere, Finland
| | - Tomoyoshi Soga
- Institute for Advanced Biosciences, Keio University, Tsuruoka, Yamagata, 997–0035, Japan
| | - Cory D. Dunn
- Department of Molecular Biology and Genetics, Koç University, Sariyer, Istanbul, 34450, Turkey
| | - Howard T. Jacobs
- BioMediTech and Tampere University Hospital, FI-33014, University of Tampere, Tampere, Finland
- Institute of Biotechnology, FI-00014, University of Helsinki, Helsinki, Finland
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28
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Diiron centre mutations in Ciona intestinalis alternative oxidase abolish enzymatic activity and prevent rescue of cytochrome oxidase deficiency in flies. Sci Rep 2015; 5:18295. [PMID: 26672986 PMCID: PMC4682143 DOI: 10.1038/srep18295] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Accepted: 10/22/2015] [Indexed: 12/31/2022] Open
Abstract
The mitochondrial alternative oxidase, AOX, carries out the non proton-motive re-oxidation of ubiquinol by oxygen in lower eukaryotes, plants and some animals. Here we created a modified version of AOX from Ciona instestinalis, carrying mutations at conserved residues predicted to be required for chelation of the diiron prosthetic group. The modified protein was stably expressed in mammalian cells or flies, but lacked enzymatic activity and was unable to rescue the phenotypes of flies knocked down for a subunit of cytochrome oxidase. The mutated AOX transgene is thus a potentially useful tool in studies of the physiological effects of AOX expression.
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29
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Mitochondrial responsibility in ageing process: innocent, suspect or guilty. Biogerontology 2015; 16:599-620. [PMID: 26105157 DOI: 10.1007/s10522-015-9585-9] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2015] [Accepted: 06/13/2015] [Indexed: 12/22/2022]
Abstract
Ageing is accompanied by the accumulation of damaged molecules in cells due to the injury produced by external and internal stressors. Among them, reactive oxygen species produced by cell metabolism, inflammation or other enzymatic processes are considered key factors. However, later research has demonstrated that a general mitochondrial dysfunction affecting electron transport chain activity, mitochondrial biogenesis and turnover, apoptosis, etc., seems to be in a central position to explain ageing. This key role is based on several effects from mitochondrial-derived ROS production to the essential maintenance of balanced metabolic activities in old organisms. Several studies have demonstrated caloric restriction, exercise or bioactive compounds mainly found in plants, are able to affect the activity and turnover of mitochondria by increasing biogenesis and mitophagy, especially in postmitotic tissues. Then, it seems that mitochondria are in the centre of metabolic procedures to be modified to lengthen life- or health-span. In this review we show the importance of mitochondria to explain the ageing process in different models or organisms (e.g. yeast, worm, fruitfly and mice). We discuss if the cause of aging is dependent on mitochondrial dysfunction of if the mitochondrial changes observed with age are a consequence of events taking place outside the mitochondrial compartment.
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30
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Holmbeck MA, Donner JR, Villa-Cuesta E, Rand DM. A Drosophila model for mito-nuclear diseases generated by an incompatible interaction between tRNA and tRNA synthetase. Dis Model Mech 2015; 8:843-54. [PMID: 26035388 PMCID: PMC4527286 DOI: 10.1242/dmm.019323] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Accepted: 04/23/2015] [Indexed: 12/30/2022] Open
Abstract
Communication between the mitochondrial and nuclear genomes is vital for cellular function. The assembly of mitochondrial enzyme complexes, which produce the majority of cellular energy, requires the coordinated expression and translation of both mitochondrially and nuclear-encoded proteins. The joint genetic architecture of this system complicates the basis of mitochondrial diseases, and mutations both in mitochondrial DNA (mtDNA)- and nuclear-encoded genes have been implicated in mitochondrial dysfunction. Previously, in a set of mitochondrial-nuclear introgression strains, we characterized a dual genome epistasis in which a naturally occurring mutation in the Drosophila simulans simw(501) mtDNA-encoded transfer RNA (tRNA) for tyrosine (tRNA(Tyr)) interacts with a mutation in the nuclear-encoded mitochondrially localized tyrosyl-tRNA synthetase from Drosophila melanogaster. Here, we show that the incompatible mitochondrial-nuclear combination results in locomotor defects, reduced mitochondrial respiratory capacity, decreased oxidative phosphorylation (OXPHOS) enzyme activity and severe alterations in mitochondrial morphology. Transgenic rescue strains containing nuclear variants of the tyrosyl-tRNA synthetase are sufficient to rescue many of the deleterious phenotypes identified when paired with the simw(501) mtDNA. However, the severity of this defective mito-nuclear interaction varies across traits and genetic backgrounds, suggesting that the impact of mitochondrial dysfunction might be tissue specific. Because mutations in mitochondrial tRNA(Tyr) are associated with exercise intolerance in humans, this mitochondrial-nuclear introgression model in Drosophila provides a means to dissect the molecular basis of these, and other, mitochondrial diseases that are a consequence of the joint genetic architecture of mitochondrial function.
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Affiliation(s)
- Marissa A Holmbeck
- Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, RI 02912, USA
| | - Julia R Donner
- Department of Ecology and Evolutionary Biology, Brown University, Providence, RI 02912, USA
| | | | - David M Rand
- Department of Ecology and Evolutionary Biology, Brown University, Providence, RI 02912, USA
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31
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Horiguchi T, Fuka M, Fujisawa K, Tanimura A, Miyoshi K, Murakami R, Noma T. Adenylate kinase 2 deficiency limits survival and regulates various genes during larval stages of Drosophila melanogaster. THE JOURNAL OF MEDICAL INVESTIGATION 2015; 61:137-50. [PMID: 24705759 DOI: 10.2152/jmi.61.137] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Adenylate kinase isozyme 2 (AK2) is located in mitochondrial intermembrane space and regulates energy metabolism by reversibly converting ATP and AMP to 2 ADPs. We previously demonstrated that disruption of the Drosophila melanogaster AK2 gene (Dak2) resulted in growth arrest during the larval stage and subsequent death. Two other groups found that human AK2 mutations cause reticular dysgenesis, a form of severe combined immunodeficiency (SCID) that is associated with severe hematopoietic defects and sensorineural deafness. However, the mechanisms underlying differential outcomes of AK2 deficiency in Drosophila and human systems remain unknown. In this study, effects of tissue-specific inactivation of the Dak2 gene on Drosophila development were analyzed using RNAi-mediated gene knockdown. In addition, to investigate the roles of AK2 in the regulation of gene expression during development, microarray analysis was performed using RNA from first and second instar larvae of Dak2-deficient mutant and wild-type D. melanogaster. Knockdown of Dak2 in all germ layers caused cessation of growth and subsequent death of flies. Microarray analysis revealed that Dak2 deficiency downregulates various genes, particularly those involved in the proteasomal function and in mitochondrial translation machinery. These data indicate that adenine nucleotide interconversion by Dak2 is crucial for developmental processes of Drosophila melanogaster.
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Affiliation(s)
- Taigo Horiguchi
- Department of Molecular Biology, Institute of Health Biosciences, the University of Tokushima Graduate School
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Mitochondrial diseases: Drosophila melanogaster as a model to evaluate potential therapeutics. Int J Biochem Cell Biol 2015; 63:60-5. [PMID: 25666557 DOI: 10.1016/j.biocel.2015.01.024] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2014] [Revised: 01/19/2015] [Accepted: 01/29/2015] [Indexed: 01/26/2023]
Abstract
While often presented as a single entity, mitochondrial diseases comprise a wide range of clinical, biochemical and genetic heterogeneous disorders. Among them, defects in the process of oxidative phosphorylation are the most prevalent. Despite intense research efforts, patients are still without effective treatment. An important part of the development of new therapeutics relies on predictive models of the pathology in order to assess their therapeutic potential. Since mitochondrial diseases are a heterogeneous group of progressive multisystemic disorders that can affect any organ at any time, the development of various in vivo models for the different diseases-associated genes defects will accelerate the search for effective therapeutics. Here, we review existing Drosophila melanogaster models for mitochondrial diseases, with a focus on alterations in oxidative phosphorylation, and discuss the potential of this powerful model organism in the process of drug target discovery. This article is part of a Directed Issue entitled: Energy Metabolism Disorders and Therapies.
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Kanabus M, Heales SJ, Rahman S. Development of pharmacological strategies for mitochondrial disorders. Br J Pharmacol 2014; 171:1798-817. [PMID: 24116962 PMCID: PMC3976606 DOI: 10.1111/bph.12456] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2013] [Revised: 09/21/2013] [Accepted: 09/26/2013] [Indexed: 01/19/2023] Open
Abstract
Mitochondrial diseases are an unusually genetically and phenotypically heterogeneous group of disorders, which are extremely challenging to treat. Currently, apart from supportive therapy, there are no effective treatments for the vast majority of mitochondrial diseases. Huge scientific effort, however, is being put into understanding the mechanisms underlying mitochondrial disease pathology and developing potential treatments. To date, a variety of treatments have been evaluated by randomized clinical trials, but unfortunately, none of these has delivered breakthrough results. Increased understanding of mitochondrial pathways and the development of many animal models, some of which are accurate phenocopies of human diseases, are facilitating the discovery and evaluation of novel prospective treatments. Targeting reactive oxygen species has been a treatment of interest for many years; however, only in recent years has it been possible to direct antioxidant delivery specifically into the mitochondria. Increasing mitochondrial biogenesis, whether by pharmacological approaches, dietary manipulation or exercise therapy, is also currently an active area of research. Modulating mitochondrial dynamics and mitophagy and the mitochondrial membrane lipid milieu have also emerged as possible treatment strategies. Recent technological advances in gene therapy, including allotopic and transkingdom gene expression and mitochondrially targeted transcription activator-like nucleases, have led to promising results in cell and animal models of mitochondrial diseases, but most of these techniques are still far from clinical application.
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Affiliation(s)
- M Kanabus
- Clinical and Molecular Genetics Unit, UCL Institute of Child Health, London, UK
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The alternative oxidase AOX does not rescue the phenotype of tko25t mutant flies. G3-GENES GENOMES GENETICS 2014; 4:2013-21. [PMID: 25147191 PMCID: PMC4199707 DOI: 10.1534/g3.114.013946] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
A point mutation [technical knockout25t (tko25t)] in the Drosophila gene coding for mitoribosomal protein S12 generates a phenotype of developmental delay and bang sensitivity. tko25t has been intensively studied as an animal model for human mitochondrial diseases associated with deficiency of mitochondrial protein synthesis and consequent multiple respiratory chain defects. Transgenic expression in Drosophila of the alternative oxidase (AOX) derived from Ciona intestinalis has previously been shown to mitigate the toxicity of respiratory chain inhibitors and to rescue mutant and knockdown phenotypes associated with cytochrome oxidase deficiency. We therefore tested whether AOX expression could compensate the mutant phenotype of tko25t using the GeneSwitch system to activate expression at different times in development. The developmental delay of tko25t was not mitigated by expression of AOX throughout development. AOX expression for 1 d after eclosion, or continuously throughout development, had no effect on the bang sensitivity of tko25t adults, and continued expression in adults older than 30 d also produced no amelioration of the phenotype. In contrast, transgenic expression of the yeast alternative NADH dehydrogenase Ndi1 was synthetically semi-lethal with tko25t and was lethal when combined with both AOX and tko25t. We conclude that AOX does not rescue tko25t and that the mutant phenotype is not solely due to limitations on electron flow in the respiratory chain, but rather to a more complex metabolic defect. The future therapeutic use of AOX in disorders of mitochondrial translation may thus be of limited value.
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Vartiainen S, Chen S, George J, Tuomela T, Luoto KR, O'Dell KMC, Jacobs HT. Phenotypic rescue of a Drosophila model of mitochondrial ANT1 disease. Dis Model Mech 2014; 7:635-48. [PMID: 24812436 PMCID: PMC4036471 DOI: 10.1242/dmm.016527] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
A point mutation in the Drosophila gene that codes for the major adult isoform of adenine nuclear translocase (ANT) represents a model for human diseases that are associated with ANT insufficiency [stress-sensitive B1 (sesB1)]. We characterized the organismal, bioenergetic and molecular phenotype of sesB1 flies then tested strategies to compensate the mutant phenotype. In addition to developmental delay and mechanical-stress-induced seizures, sesB1 flies have an impaired response to sound, defective male courtship, female sterility and curtailed lifespan. These phenotypes, excluding the latter two, are shared with the mitoribosomal protein S12 mutant, tko25t. Mitochondria from sesB1 adults showed a decreased respiratory control ratio and downregulation of cytochrome oxidase. sesB1 adults exhibited ATP depletion, lactate accumulation and changes in gene expression that were consistent with a metabolic shift towards glycolysis, characterized by activation of lactate dehydrogenase and anaplerotic pathways. Females also showed downregulation of many genes that are required for oogenesis, and their eggs, although fertilized, failed to develop to the larval stages. The sesB1 phenotypes of developmental delay and mechanical-stress-induced seizures were alleviated by an altered mitochondrial DNA background. Female sterility was substantially rescued by somatic expression of alternative oxidase (AOX) from the sea squirt Ciona intestinalis, whereas AOX did not alleviate developmental delay. Our findings illustrate the potential of different therapeutic strategies for ANT-linked diseases, based on alleviating metabolic stress.
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Affiliation(s)
- Suvi Vartiainen
- BioMediTech and Tampere University Hospital, FI-33014 University of Tampere, Finland
| | - Shanjun Chen
- BioMediTech and Tampere University Hospital, FI-33014 University of Tampere, Finland
| | - Jack George
- BioMediTech and Tampere University Hospital, FI-33014 University of Tampere, Finland
| | - Tea Tuomela
- BioMediTech and Tampere University Hospital, FI-33014 University of Tampere, Finland
| | - Kaisa R Luoto
- BioMediTech and Tampere University Hospital, FI-33014 University of Tampere, Finland
| | - Kevin M C O'Dell
- Institute of Molecular, Cell and Systems Biology, University of Glasgow, Glasgow G12 8QQ, Scotland, UK
| | - Howard T Jacobs
- BioMediTech and Tampere University Hospital, FI-33014 University of Tampere, Finland. Research Program of Molecular Neurology, FI-00014 University of Helsinki, Finland.
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Kemppainen KK, Rinne J, Sriram A, Lakanmaa M, Zeb A, Tuomela T, Popplestone A, Singh S, Sanz A, Rustin P, Jacobs HT. Expression of alternative oxidase in Drosophila ameliorates diverse phenotypes due to cytochrome oxidase deficiency. Hum Mol Genet 2013; 23:2078-93. [PMID: 24293544 PMCID: PMC3959817 DOI: 10.1093/hmg/ddt601] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Mitochondrial dysfunction is a significant factor in human disease, ranging from systemic disorders of childhood to cardiomyopathy, ischaemia and neurodegeneration. Cytochrome oxidase, the terminal enzyme of the mitochondrial respiratory chain, is a frequent target. Lower eukaryotes possess alternative respiratory-chain enzymes that provide non-proton-translocating bypasses for respiratory complexes I (single-subunit reduced nicotinamide adenine dinucleotide dehydrogenases, e.g. Ndi1 from yeast) or III + IV [alternative oxidase (AOX)], under conditions of respiratory stress or overload. In previous studies, it was shown that transfer of yeast Ndi1 or Ciona intestinalis AOX to Drosophila was able to overcome the lethality produced by toxins or partial knockdown of complex I or IV. Here, we show that AOX can provide a complete or substantial rescue of a range of phenotypes induced by global or tissue-specific knockdown of different cIV subunits, including integral subunits required for catalysis, as well as peripheral subunits required for multimerization and assembly. AOX was also able to overcome the pupal lethality produced by muscle-specific knockdown of subunit CoVb, although the rescued flies were short lived and had a motility defect. cIV knockdown in neurons was not lethal during development but produced a rapidly progressing locomotor and seizure-sensitivity phenotype, which was substantially alleviated by AOX. Expression of Ndi1 exacerbated the neuronal phenotype produced by cIV knockdown. Ndi1 expressed in place of essential cI subunits produced a distinct residual phenotype of delayed development, bang sensitivity and male sterility. These findings confirm the potential utility of alternative respiratory chain enzymes as tools to combat mitochondrial disease, while indicating important limitations thereof.
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Affiliation(s)
- Kia K Kemppainen
- Institute of Biomedical Technology and Tampere University Hospital, University of Tampere, FI-33014 Tampere, Finland
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Maeda Y, Chida J. Control of cell differentiation by mitochondria, typically evidenced in dictyostelium development. Biomolecules 2013; 3:943-66. [PMID: 24970198 PMCID: PMC4030964 DOI: 10.3390/biom3040943] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2013] [Revised: 11/01/2013] [Accepted: 11/02/2013] [Indexed: 01/15/2023] Open
Abstract
In eukaryotic cells, mitochondria are self-reproducing organelles with their own DNA and they play a central role in adenosine triphosphate (ATP) synthesis by respiration. Increasing evidence indicates that mitochondria also have critical and multiple functions in the initiation of cell differentiation, cell-type determination, cell movement, and pattern formation. This has been most strikingly realized in development of the cellular slime mold Dictyostelium. For example, the expression of the mitochondrial ribosomal protein S4 (mt-rps4) gene is required for the initial differentiation. The Dictyostelium homologue (Dd-TRAP1) of TRAP-1 (tumor necrosis receptor-associated protein 1), a mitochondrial molecular chaperone belonging to the Hsp90 family, allows the prompt transition of cells from growth to differentiation through a novel prestarvation factor (PSF-3) in growth medium. Moreover, a cell-type-specific organelle named a prespore-specific vacuole (PSV) is constructed by mitochondrial transformation with the help of the Golgi complex. Mitochondria are also closely involved in a variety of cellular activities including CN-resistant respiration and apoptosis. These mitochondrial functions are reviewed in this article, with special emphasis on the regulation of Dictyostelium development.
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Affiliation(s)
- Yasuo Maeda
- Department of Developmental Biology and Neurosciences, Graduate School of Life Sciences, Tohoku University, Aoba, Sendai 980-8578, Japan.
| | - Junji Chida
- Division of Molecular Neurobiology, Institute for Enzyme Research, The University of Tokushima, Kuramoto-cho, Tokushima 770-8503, Japan.
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Guitart T, Picchioni D, Piñeyro D, Ribas de Pouplana L. Human mitochondrial disease-like symptoms caused by a reduced tRNA aminoacylation activity in flies. Nucleic Acids Res 2013; 41:6595-608. [PMID: 23677612 PMCID: PMC3711456 DOI: 10.1093/nar/gkt402] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The translation of genes encoded in the mitochondrial genome requires specific machinery that functions in the organelle. Among the many mutations linked to human disease that affect mitochondrial translation, several are localized to nuclear genes coding for mitochondrial aminoacyl-transfer RNA synthetases. The molecular significance of these mutations is poorly understood, but it is expected to be similar to that of the mutations affecting mitochondrial transfer RNAs. To better understand the molecular features of diseases caused by these mutations, and to improve their diagnosis and therapeutics, we have constructed a Drosophila melanogaster model disrupting the mitochondrial seryl-tRNA synthetase by RNA interference. At the molecular level, the knockdown generates a reduction in transfer RNA serylation, which correlates with the severity of the phenotype observed. The silencing compromises viability, longevity, motility and tissue development. At the cellular level, the knockdown alters mitochondrial morphology, biogenesis and function, and induces lactic acidosis and reactive oxygen species accumulation. We report that administration of antioxidant compounds has a palliative effect of some of these phenotypes. In conclusion, the fly model generated in this work reproduces typical characteristics of pathologies caused by mutations in the mitochondrial aminoacylation system, and can be useful to assess therapeutic approaches.
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Affiliation(s)
- Tanit Guitart
- Institute for Research in Biomedicine (IRB Barcelona), Gene Translation Laboratory, c/Baldiri Reixac 10, Barcelona, 08028, Catalonia, Spain
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Genetic and pharmacological manipulations that alter metabolism suppress seizure-like activity in Drosophila. Brain Res 2012; 1496:94-103. [PMID: 23247062 DOI: 10.1016/j.brainres.2012.12.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2012] [Revised: 11/21/2012] [Accepted: 12/06/2012] [Indexed: 01/01/2023]
Abstract
There is increasing evidence that alterations in metabolism can affect seizure susceptibility in a wide range of organisms. In order to investigate the link between metabolism and seizures, we took advantage of a group of Drosophila mutants, the Bang-sensitive (BS) paralytics, which are 3-10 times more susceptible to seizure-like activity (SLA) than wild type flies following a variety of stimuli including mechanical shock. To alter metabolism, we introduced the atsugari (atu) mutation into three of the BS mutants, easily shocked (eas), bang senseless (bss), and technical knockout (tko). The atu mutants, which exhibit reduced expression of the Drosophila ortholog of dystroglycan gene, have previously been shown to have a higher metabolic rate than wild type flies. Following mechanical shock, all three BS;atu double mutants displayed a reduction in SLA and the eas;atu and tko;atu double mutants recovered from the shock quicker than the respective single mutant BS flies. In addition, the eas;atu and tko;atu flies displayed higher levels of metabolism as compared to the single mutant BS flies. To further study the correlation between metabolism and seizure susceptibility, the three BS strains were fed a sulfonylurea drug (tolbutamide) known to both increase heamolymph glucose concentrations and stimulate lipid metabolism in flies. Following mechanical shock, the eas and tko mutants fed tolbutamide displayed less SLA and recovered quicker than unfed flies. While the bss mutants fed tolbutamide did not display a reduction in SLA, they did recover quicker than unfed controls. These data indicate that the upregulation of metabolism can have a protective effect against seizure susceptibility, a result that suggests new avenues for possible drug development.
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Senthilan PR, Piepenbrock D, Ovezmyradov G, Nadrowski B, Bechstedt S, Pauls S, Winkler M, Möbius W, Howard J, Göpfert MC. Drosophila auditory organ genes and genetic hearing defects. Cell 2012; 150:1042-54. [PMID: 22939627 DOI: 10.1016/j.cell.2012.06.043] [Citation(s) in RCA: 143] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2011] [Revised: 03/02/2012] [Accepted: 06/20/2012] [Indexed: 12/22/2022]
Abstract
The Drosophila auditory organ shares equivalent transduction mechanisms with vertebrate hair cells, and both are specified by atonal family genes. Using a whole-organ knockout strategy based on atonal, we have identified 274 Drosophila auditory organ genes. Only four of these genes had previously been associated with fly hearing, yet one in five of the genes that we identified has a human cognate that is implicated in hearing disorders. Mutant analysis of 42 genes shows that more than half of them contribute to auditory organ function, with phenotypes including hearing loss, auditory hypersusceptibility, and ringing ears. We not only discover ion channels and motors important for hearing, but also show that auditory stimulus processing involves chemoreceptor proteins as well as phototransducer components. Our findings demonstrate mechanosensory roles for ionotropic receptors and visual rhodopsins and indicate that different sensory modalities utilize common signaling cascades.
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Affiliation(s)
- Pingkalai R Senthilan
- Department of Cellular Neurobiology, University of Göttingen, Julia-Lermontowa-Weg 3, 37077 Göttingen, Germany
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Abstract
Phenotypes relevant to oxidative phosphorylation (OXPHOS) in eukaryotes are jointly determined by nuclear and mitochondrial DNA (mtDNA). Thus, in humans, the variable clinical presentations of mitochondrial disease patients bearing the same primary mutation, whether in nuclear or mitochondrial DNA, have been attributed to putative genetic determinants carried in the “other” genome, though their identity and the molecular mechanism(s) by which they might act remain elusive. Here we demonstrate cytoplasmic suppression of the mitochondrial disease-like phenotype of the Drosophila melanogaster nuclear mutant tko25t, which includes developmental delay, seizure sensitivity, and defective male courtship. The tko25t strain carries a mutation in a mitoribosomal protein gene, causing OXPHOS deficiency due to defective intramitochondrial protein synthesis. Phenotypic suppression was associated with increased mtDNA copy number and increased mitochondrial biogenesis, as measured by the expression levels of porin voltage dependent anion channel and Spargel (PGC1α). Ubiquitous overexpression of Spargel in tko25t flies phenocopied the suppressor, identifying it as a key mechanistic target thereof. Suppressor-strain mtDNAs differed from related nonsuppressor strain mtDNAs by several coding-region polymorphisms and by length and sequence variation in the noncoding region (NCR), in which the origin of mtDNA replication is located. Cytoplasm from four of five originally Wolbachia-infected strains showed the same suppressor effect, whereas that from neither of two uninfected strains did so, suggesting that the stress of chronic Wolbachia infection may provide evolutionary selection for improved mitochondrial fitness under metabolic stress. Our findings provide a paradigm for understanding the role of mtDNA genotype in human disease.
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Zheng W, Peng T, He W, Zhang H. High-throughput sequencing to reveal genes involved in reproduction and development in Bactrocera dorsalis (Diptera: Tephritidae). PLoS One 2012; 7:e36463. [PMID: 22570719 PMCID: PMC3343016 DOI: 10.1371/journal.pone.0036463] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2011] [Accepted: 04/06/2012] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Tephritid fruit flies in the genus Bactrocera are of major economic significance in agriculture causing considerable loss to the fruit and vegetable industry. Currently, there is no ideal control program. Molecular means is an effective method for pest control at present, but genomic or transcriptomic data for members of this genus remains limited. To facilitate molecular research into reproduction and development mechanisms, and finally effective control on these pests, an extensive transcriptome for the oriental fruit fly Bactrocera dorsalis was produced using the Roche 454-FLX platform. RESULTS We obtained over 350 million bases of cDNA derived from the whole body of B. dorsalis at different developmental stages. In a single run, 747,206 sequencing reads with a mean read length of 382 bp were obtained. These reads were assembled into 28,782 contigs and 169,966 singletons. The mean contig size was 750 bp and many nearly full-length transcripts were assembled. Additionally, we identified a great number of genes that are involved in reproduction and development as well as genes that represent nearly all major conserved metazoan signal transduction pathways, such as insulin signal transduction. Furthermore, transcriptome changes during development were analyzed. A total of 2,977 differentially expressed genes (DEGs) were detected between larvae and pupae libraries, while there were 1,621 DEGs between adults and larvae, and 2,002 between adults and pupae. These DEGs were functionally annotated with KEGG pathway annotation and 9 genes were validated by qRT-PCR. CONCLUSION Our data represent the extensive sequence resources available for B. dorsalis and provide for the first time access to the genetic architecture of reproduction and development as well as major signal transduction pathways in the Tephritid fruit fly pests, allowing us to elucidate the molecular mechanisms underlying courtship, ovipositing, development and detailed analyses of the signal transduction pathways.
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Affiliation(s)
- Weiwei Zheng
- State Key Laboratory of Agricultural Microbiology, Hubei Key Laboratory of Insect Resource Application and Sustainable Pest Control and Institute of Urban and Horticultural Pests, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, People's Republic of China
| | - Tao Peng
- State Key Laboratory of Agricultural Microbiology, Hubei Key Laboratory of Insect Resource Application and Sustainable Pest Control and Institute of Urban and Horticultural Pests, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, People's Republic of China
| | - Wei He
- Shanghai Hanyu Bio-Lab, Shanghai, People's Republic of China
| | - Hongyu Zhang
- State Key Laboratory of Agricultural Microbiology, Hubei Key Laboratory of Insect Resource Application and Sustainable Pest Control and Institute of Urban and Horticultural Pests, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, People's Republic of China
- * E-mail:
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Rea SL, Graham BH, Nakamaru-Ogiso E, Kar A, Falk MJ. Bacteria, yeast, worms, and flies: exploiting simple model organisms to investigate human mitochondrial diseases. ACTA ACUST UNITED AC 2011; 16:200-18. [PMID: 20818735 DOI: 10.1002/ddrr.114] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The extensive conservation of mitochondrial structure, composition, and function across evolution offers a unique opportunity to expand our understanding of human mitochondrial biology and disease. By investigating the biology of much simpler model organisms, it is often possible to answer questions that are unreachable at the clinical level. Here, we review the relative utility of four different model organisms, namely the bacterium Escherichia coli, the yeast Saccharomyces cerevisiae, the nematode Caenorhabditis elegans, and the fruit fly Drosophila melanogaster, in studying the role of mitochondrial proteins relevant to human disease. E. coli are single cell, prokaryotic bacteria that have proven to be a useful model system in which to investigate mitochondrial respiratory chain protein structure and function. S. cerevisiae is a single-celled eukaryote that can grow equally well by mitochondrial-dependent respiration or by ethanol fermentation, a property that has proven to be a veritable boon for investigating mitochondrial functionality. C. elegans is a multicellular, microscopic worm that is organized into five major tissues and has proven to be a robust model animal for in vitro and in vivo studies of primary respiratory chain dysfunction and its potential therapies in humans. Studied for over a century, D. melanogaster is a classic metazoan model system offering an abundance of genetic tools and reagents that facilitates investigations of mitochondrial biology using both forward and reverse genetics. The respective strengths and limitations of each species relative to mitochondrial studies are explored. In addition, an overview is provided of major discoveries made in mitochondrial biology in each of these four model systems.
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Affiliation(s)
- Shane L Rea
- Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio, San Antonio, TX 78245-3207, USA.
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TRPM channels mediate zinc homeostasis and cellular growth during Drosophila larval development. Cell Metab 2010; 12:386-397. [PMID: 20889130 DOI: 10.1016/j.cmet.2010.08.012] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2009] [Revised: 04/26/2010] [Accepted: 06/24/2010] [Indexed: 12/22/2022]
Abstract
TRPM channels have emerged as key mediators of diverse physiological functions. However, the ionic permeability relevant to physiological function in vivo remains unclear for most members. We report that the single Drosophila TRPM gene (dTRPM) generates a conductance permeable to divalent cations, especially Zn(2+) and in vivo a loss-of-function mutation in dTRPM disrupts intracellular Zn(2+) homeostasis. TRPM deficiency leads to profound reduction in larval growth resulting from a decrease in cell size and associated defects in mitochondrial structure and function. These phenotypes are cell-autonomous and can be recapitulated in wild-type animals by Zn(2+) depletion. Both the cell size and mitochondrial defect can be rescued by extracellular Zn(2+) supplementation. Thus our results implicate TRPM channels in the regulation of cellular Zn(2+) in vivo. We propose that regulation of Zn(2+) homeostasis through dTRPM channels is required to support molecular processes that mediate class I PI3K-regulated cell growth.
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Expression of the yeast NADH dehydrogenase Ndi1 in Drosophila confers increased lifespan independently of dietary restriction. Proc Natl Acad Sci U S A 2010; 107:9105-10. [PMID: 20435911 DOI: 10.1073/pnas.0911539107] [Citation(s) in RCA: 101] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Mutations in mitochondrial oxidative phosphorylation complex I are associated with multiple pathologies, and complex I has been proposed as a crucial regulator of animal longevity. In yeast, the single-subunit NADH dehydrogenase Ndi1 serves as a non-proton-translocating alternative enzyme that replaces complex I, bringing about the reoxidation of intramitochondrial NADH. We have created transgenic strains of Drosophila that express yeast NDI1 ubiquitously. Mitochondrial extracts from NDI1-expressing flies displayed a rotenone-insensitive NADH dehydrogenase activity, and functionality of the enzyme in vivo was confirmed by the rescue of lethality resulting from RNAi knockdown of complex I. NDI1 expression increased median, mean, and maximum lifespan independently of dietary restriction, and with no change in sirtuin activity. NDI1 expression mitigated the aging associated decline in respiratory capacity and the accompanying increase in mitochondrial reactive oxygen species production, and resulted in decreased accumulation of markers of oxidative damage in aged flies. Our results support a central role of mitochondrial oxidative phosphorylation complex I in influencing longevity via oxidative stress, independently of pathways connected to nutrition and growth signaling.
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Zhou RR, Wang B, Wang J, Schatten H, Zhang YZ. Is the mitochondrial cloud the selection machinery for preferentially transmitting wild-type mtDNA between generations? Rewinding Müller's ratchet efficiently. Curr Genet 2010; 56:101-7. [PMID: 20179933 DOI: 10.1007/s00294-010-0291-5] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2009] [Revised: 12/30/2009] [Accepted: 01/24/2010] [Indexed: 11/30/2022]
Abstract
In animal mitochondrial DNA inheritance, it remains largely unclear where the mitochondrial genetic bottleneck localizes and how it works in rewinding Müller's ratchet. In a variety of different animals germ plasm mRNAs typically aggregate along with numerous mitochondria to form the mitochondrial cloud (MC) during oogenesis. The MC has been found to serve as messenger transport organizer for germ plasm mRNAs. Germ plasm RNAs in MC will specifically distribute to the primordial germ cells of the future embryo. It has been proposed that the MC might be the site where selected mitochondria accumulate for specific transmission to grandchildren but this idea received relatively little attention and the criterion by which mitochondria are selected remains unknown. Our recent results in zebrafish provided further evidence for selective mitochondria accumulation in the MC by showing that mitochondria with high-inner membrane potential tend to be recruited preferentially into the MC, and these mitochondria are transported along with germ plasm to the cortex of the vegetal pole. By analyzing the composition, behavior and functions of the MC, and in reviewing related literature, we found strong support for the proposition that the MC corresponds to the position and function of the mitochondrial genetic bottleneck.
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Affiliation(s)
- Rong Rong Zhou
- Department of Life Sciences, Liaocheng University, Liaocheng 252059, Shandong, China
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47
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Sensitivity to seizure-like activity in Drosophila following acute hypoxia and hypercapnia. Brain Res 2010; 1316:120-8. [DOI: 10.1016/j.brainres.2009.12.036] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2009] [Revised: 12/08/2009] [Accepted: 12/12/2009] [Indexed: 11/21/2022]
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48
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Fernández-Ayala DJM, Chen S, Kemppainen E, O'Dell KMC, Jacobs HT. Gene expression in a Drosophila model of mitochondrial disease. PLoS One 2010; 5:e8549. [PMID: 20066047 PMCID: PMC2798955 DOI: 10.1371/journal.pone.0008549] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2009] [Accepted: 11/28/2009] [Indexed: 01/12/2023] Open
Abstract
Background A point mutation in the Drosophila gene technical knockout (tko), encoding mitoribosomal protein S12, was previously shown to cause a phenotype of respiratory chain deficiency, developmental delay, and neurological abnormalities similar to those presented in many human mitochondrial disorders, as well as defective courtship behavior. Methodology/Principal Findings Here, we describe a transcriptome-wide analysis of gene expression in tko25t mutant flies that revealed systematic and compensatory changes in the expression of genes connected with metabolism, including up-regulation of lactate dehydrogenase and of many genes involved in the catabolism of fats and proteins, and various anaplerotic pathways. Gut-specific enzymes involved in the primary mobilization of dietary fats and proteins, as well as a number of transport functions, were also strongly up-regulated, consistent with the idea that oxidative phosphorylation OXPHOS dysfunction is perceived physiologically as a starvation for particular biomolecules. In addition, many stress-response genes were induced. Other changes may reflect a signature of developmental delay, notably a down-regulation of genes connected with reproduction, including gametogenesis, as well as courtship behavior in males; logically this represents a programmed response to a mitochondrially generated starvation signal. The underlying signalling pathway, if conserved, could influence many physiological processes in response to nutritional stress, although any such pathway involved remains unidentified. Conclusions/Significance These studies indicate that general and organ-specific metabolism is transformed in response to mitochondrial dysfunction, including digestive and absorptive functions, and give important clues as to how novel therapeutic strategies for mitochondrial disorders might be developed.
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Affiliation(s)
| | - Shanjun Chen
- Institute of Medical Technology and Tampere University Hospital, University of Tampere, Tampere, Finland
| | - Esko Kemppainen
- Institute of Medical Technology and Tampere University Hospital, University of Tampere, Tampere, Finland
| | - Kevin M. C. O'Dell
- Faculty of Biomedical and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Howard T. Jacobs
- Institute of Medical Technology and Tampere University Hospital, University of Tampere, Tampere, Finland
- Faculty of Biomedical and Life Sciences, University of Glasgow, Glasgow, United Kingdom
- * E-mail:
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Kemppainen E, Fernández-Ayala DJM, Galbraith LCA, O'Dell KMC, Jacobs HT. Phenotypic suppression of the Drosophila mitochondrial disease-like mutant tko(25t) by duplication of the mutant gene in its natural chromosomal context. Mitochondrion 2009; 9:353-63. [PMID: 19616644 DOI: 10.1016/j.mito.2009.07.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2009] [Revised: 06/24/2009] [Accepted: 07/13/2009] [Indexed: 10/20/2022]
Abstract
A mutation in the Drosophila gene technical knockout (tko(25t)), encoding mitoribosomal protein S12, phenocopies human mitochondrial disease. We isolated three spontaneous X-dominant suppressors of tko(25t) (designated Weeble), exhibiting almost wild-type phenotype and containing overlapping segmental duplications including the mutant allele, plus a second mitoribosomal protein gene, mRpL14. Ectopic, expressed copies of tko(25t) and mRpL14 conferred no phenotypic suppression. When placed over a null allele of tko, Weeble retained the mutant phenotype, even in the presence of additional transgenic copies of tko(25t). Increased mutant gene dosage can thus compensate the mutant phenotype, but only when located in its normal chromosomal context.
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Affiliation(s)
- Esko Kemppainen
- Institute of Medical Technology and Tampere University Hospital, FI-33014 University of Tampere, Finland
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Expression of the Ciona intestinalis alternative oxidase (AOX) in Drosophila complements defects in mitochondrial oxidative phosphorylation. Cell Metab 2009; 9:449-60. [PMID: 19416715 DOI: 10.1016/j.cmet.2009.03.004] [Citation(s) in RCA: 127] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2008] [Revised: 11/27/2008] [Accepted: 03/11/2009] [Indexed: 11/20/2022]
Abstract
Defects in mitochondrial OXPHOS are associated with diverse and mostly intractable human disorders. The single-subunit alternative oxidase (AOX) found in many eukaryotes, but not in arthropods or vertebrates, offers a potential bypass of the OXPHOS cytochrome chain under conditions of pathological OXPHOS inhibition. We have engineered Ciona intestinalis AOX for conditional expression in Drosophila melanogaster. Ubiquitous AOX expression produced no detrimental phenotype in wild-type flies. However, mitochondrial suspensions from AOX-expressing flies exhibited a significant cyanide-resistant substrate oxidation, and the flies were partially resistant to both cyanide and antimycin. AOX expression was able to complement the semilethality of partial knockdown of both cyclope (COXVIc) and the complex IV assembly factor Surf1. It also rescued the locomotor defect and excess mitochondrial ROS production of flies mutated in dj-1beta, a Drosophila homolog of the human Parkinson's disease gene DJ1. AOX appears to offer promise as a wide-spectrum therapeutic tool in OXPHOS disorders.
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