51
|
Abstract
Mitochondrial diseases are a diverse group of inborn disorders affecting cellular energy production by oxidative phosphorylation (OXPHOS) via the five (CI‐CV) mitochondrial respiratory chain (MRC) complexes. The sea squirt alternative oxidase (AOX) is able to bypass the distal part of the MRC and was shown to alleviate the consequences of CIII and CIV defects in several cellular and Drosophila models. In this issue of EMBO Molecular Medicine, Rajendran et al (2019) demonstrate the first proof of concept in mammals, by showing that AOX is capable to extend lifespan and prevent heart failure in a CIII deficient mouse model, raising the possibility of future human AOX bypass treatment.
Collapse
Affiliation(s)
- Ann Saada
- The Monique and Jacques Roboh Department of Genetic Research, Department of Genetics and Metabolic Diseases, Hadassah Medical Center, Jerusalem, Israel.,Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
| |
Collapse
|
52
|
A potassium channel β-subunit couples mitochondrial electron transport to sleep. Nature 2019; 568:230-234. [PMID: 30894743 DOI: 10.1038/s41586-019-1034-5] [Citation(s) in RCA: 89] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Accepted: 02/19/2019] [Indexed: 12/31/2022]
Abstract
The essential but enigmatic functions of sleep1,2 must be reflected in molecular changes sensed by the brain's sleep-control systems. In the fruitfly Drosophila, about two dozen sleep-inducing neurons3 with projections to the dorsal fan-shaped body (dFB) adjust their electrical output to sleep need4, via the antagonistic regulation of two potassium conductances: the leak channel Sandman imposes silence during waking, whereas increased A-type currents through Shaker support tonic firing during sleep5. Here we show that oxidative byproducts of mitochondrial electron transport6,7 regulate the activity of dFB neurons through a nicotinamide adenine dinucleotide phosphate (NADPH) cofactor bound to the oxidoreductase domain8,9 of Shaker's KVβ subunit, Hyperkinetic10,11. Sleep loss elevates mitochondrial reactive oxygen species in dFB neurons, which register this rise by converting Hyperkinetic to the NADP+-bound form. The oxidation of the cofactor slows the inactivation of the A-type current and boosts the frequency of action potentials, thereby promoting sleep. Energy metabolism, oxidative stress, and sleep-three processes implicated independently in lifespan, ageing, and degenerative disease6,12-14-are thus mechanistically connected. KVβ substrates8,15,16 or inhibitors that alter the ratio of bound NADPH to NADP+ (and hence the record of sleep debt or waking time) represent prototypes of potential sleep-regulatory drugs.
Collapse
|
53
|
Alternative NAD(P)H dehydrogenase and alternative oxidase: Proposed physiological roles in animals. Mitochondrion 2019; 45:7-17. [DOI: 10.1016/j.mito.2018.01.009] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Revised: 11/01/2017] [Accepted: 01/26/2018] [Indexed: 12/12/2022]
|
54
|
Tward CE, Singh J, Cygelfarb W, McDonald AE. Identification of the alternative oxidase gene and its expression in the copepod Tigriopus californicus. Comp Biochem Physiol B Biochem Mol Biol 2019; 228:41-50. [DOI: 10.1016/j.cbpb.2018.11.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Accepted: 11/16/2018] [Indexed: 12/27/2022]
|
55
|
González de Cózar JM, Gerards M, Teeri E, George J, Dufour E, Jacobs HT, Jõers P. RNase H1 promotes replication fork progression through oppositely transcribed regions of Drosophila mitochondrial DNA. J Biol Chem 2019; 294:4331-4344. [PMID: 30635398 PMCID: PMC6433063 DOI: 10.1074/jbc.ra118.007015] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Revised: 01/09/2019] [Indexed: 11/12/2022] Open
Abstract
Mitochondrial DNA (mtDNA) replication uses a simple core machinery similar to those of bacterial viruses and plasmids, but its components are challenging to unravel. Here, we found that, as in mammals, the single Drosophila gene for RNase H1 (rnh1) has alternative translational start sites, resulting in two polypeptides, targeted to either mitochondria or the nucleus. RNAi-mediated rnh1 knockdown did not influence growth or viability of S2 cells, but compromised mtDNA integrity and copy number. rnh1 knockdown in intact flies also produced a phenotype of impaired mitochondrial function, characterized by respiratory chain deficiency, locomotor dysfunction, and decreased lifespan. Its overexpression in S2 cells resulted in cell lethality after 5–9 days, attributable to the nuclearly localized isoform. rnh1 knockdown and overexpression produced opposite effects on mtDNA replication intermediates. The most pronounced effects were seen in genome regions beyond the major replication pauses where the replication fork needs to progress through a gene cluster that is transcribed in the opposite direction. RNase H1 deficiency led to an accumulation of replication intermediates in these zones, abundant mtDNA molecules joined by four-way junctions, and species consistent with fork regression from the origin. These findings indicate replication stalling due to the presence of unprocessed RNA/DNA heteroduplexes, potentially leading to the degradation of collapsed forks or to replication restart by a mechanism involving strand invasion. Both mitochondrial RNA and DNA syntheses were affected by rnh1 knockdown, suggesting that RNase H1 also plays a role in integrating or coregulating these processes in Drosophila mitochondria.
Collapse
Affiliation(s)
- Jose M González de Cózar
- From the Faculty of Medicine and Health Technology and Tampere University Hospital, FI-33014 Tampere University, Finland
| | - Mike Gerards
- From the Faculty of Medicine and Health Technology and Tampere University Hospital, FI-33014 Tampere University, Finland
| | - Eveliina Teeri
- From the Faculty of Medicine and Health Technology and Tampere University Hospital, FI-33014 Tampere University, Finland
| | - Jack George
- From the Faculty of Medicine and Health Technology and Tampere University Hospital, FI-33014 Tampere University, Finland
| | - Eric Dufour
- From the Faculty of Medicine and Health Technology and Tampere University Hospital, FI-33014 Tampere University, Finland
| | - Howard T Jacobs
- From the Faculty of Medicine and Health Technology and Tampere University Hospital, FI-33014 Tampere University, Finland, .,Institute of Biotechnology, FI-00014 University of Helsinki, Finland, and
| | - Priit Jõers
- From the Faculty of Medicine and Health Technology and Tampere University Hospital, FI-33014 Tampere University, Finland.,Institute of Molecular and Cell Biology, University of Tartu, Riia 23, 51010 Tartu, Estonia
| |
Collapse
|
56
|
Andjelković A, Mordas A, Bruinsma L, Ketola A, Cannino G, Giordano L, Dhandapani PK, Szibor M, Dufour E, Jacobs HT. Expression of the Alternative Oxidase Influences Jun N-Terminal Kinase Signaling and Cell Migration. Mol Cell Biol 2018; 38:e00110-18. [PMID: 30224521 PMCID: PMC6275184 DOI: 10.1128/mcb.00110-18] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Revised: 04/11/2018] [Accepted: 09/11/2018] [Indexed: 12/25/2022] Open
Abstract
Downregulation of Jun N-terminal kinase (JNK) signaling inhibits cell migration in diverse model systems. In Drosophila pupal development, attenuated JNK signaling in the thoracic dorsal epithelium leads to defective midline closure, resulting in cleft thorax. Here we report that concomitant expression of the Ciona intestinalis alternative oxidase (AOX) was able to compensate for JNK pathway downregulation, substantially correcting the cleft thorax phenotype. AOX expression also promoted wound-healing behavior and single-cell migration in immortalized mouse embryonic fibroblasts (iMEFs), counteracting the effect of JNK pathway inhibition. However, AOX was not able to rescue developmental phenotypes resulting from knockdown of the AP-1 transcription factor, the canonical target of JNK, nor its targets and had no effect on AP-1-dependent transcription. The migration of AOX-expressing iMEFs in the wound-healing assay was differentially stimulated by antimycin A, which redirects respiratory electron flow through AOX, altering the balance between mitochondrial ATP and heat production. Since other treatments affecting mitochondrial ATP did not stimulate wound healing, we propose increased mitochondrial heat production as the most likely primary mechanism of action of AOX in promoting cell migration in these various contexts.
Collapse
Affiliation(s)
- Ana Andjelković
- Faculty of Medicine and Life Sciences, University of Tampere, Tampere, Finland
- BioMediTech Institute, University of Tampere, Tampere, Finland
| | - Amelia Mordas
- Faculty of Medicine and Life Sciences, University of Tampere, Tampere, Finland
- BioMediTech Institute, University of Tampere, Tampere, Finland
| | - Lyon Bruinsma
- Faculty of Medicine and Life Sciences, University of Tampere, Tampere, Finland
- BioMediTech Institute, University of Tampere, Tampere, Finland
| | - Annika Ketola
- Faculty of Medicine and Life Sciences, University of Tampere, Tampere, Finland
- BioMediTech Institute, University of Tampere, Tampere, Finland
| | - Giuseppe Cannino
- Faculty of Medicine and Life Sciences, University of Tampere, Tampere, Finland
- BioMediTech Institute, University of Tampere, Tampere, Finland
| | - Luca Giordano
- Faculty of Medicine and Life Sciences, University of Tampere, Tampere, Finland
- BioMediTech Institute, University of Tampere, Tampere, Finland
| | - Praveen K Dhandapani
- Faculty of Medicine and Life Sciences, University of Tampere, Tampere, Finland
- BioMediTech Institute, University of Tampere, Tampere, Finland
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Marten Szibor
- Faculty of Medicine and Life Sciences, University of Tampere, Tampere, Finland
- BioMediTech Institute, University of Tampere, Tampere, Finland
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Eric Dufour
- Faculty of Medicine and Life Sciences, University of Tampere, Tampere, Finland
- BioMediTech Institute, University of Tampere, Tampere, Finland
| | - Howard T Jacobs
- Faculty of Medicine and Life Sciences, University of Tampere, Tampere, Finland
- BioMediTech Institute, University of Tampere, Tampere, Finland
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| |
Collapse
|
57
|
Murphy MP, Hartley RC. Mitochondria as a therapeutic target for common pathologies. Nat Rev Drug Discov 2018; 17:865-886. [PMID: 30393373 DOI: 10.1038/nrd.2018.174] [Citation(s) in RCA: 470] [Impact Index Per Article: 78.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Although the development of mitochondrial therapies has largely focused on diseases caused by mutations in mitochondrial DNA or in nuclear genes encoding mitochondrial proteins, it has been found that mitochondrial dysfunction also contributes to the pathology of many common disorders, including neurodegeneration, metabolic disease, heart failure, ischaemia-reperfusion injury and protozoal infections. Mitochondria therefore represent an important drug target for these highly prevalent diseases. Several strategies aimed at therapeutically restoring mitochondrial function are emerging, and a small number of agents have entered clinical trials. This Review discusses the opportunities and challenges faced for the further development of mitochondrial pharmacology for common pathologies.
Collapse
Affiliation(s)
- Michael P Murphy
- Medical Research Council (MRC) Mitochondrial Biology Unit, University of Cambridge, Cambridge, UK
| | | |
Collapse
|
58
|
Alternative respiratory chain enzymes: Therapeutic potential and possible pitfalls. Biochim Biophys Acta Mol Basis Dis 2018; 1865:854-866. [PMID: 30342157 DOI: 10.1016/j.bbadis.2018.10.012] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2018] [Revised: 10/03/2018] [Accepted: 10/05/2018] [Indexed: 01/07/2023]
Abstract
The alternative respiratory chain (aRC), comprising the alternative NADH dehydrogenases (NDX) and quinone oxidases (AOX), is found in microbes, fungi and plants, where it buffers stresses arising from restrictions on electron flow in the oxidative phosphorylation system. The aRC enzymes are also found in species belonging to most metazoan phyla, including some chordates and arthropods species, although not in vertebrates or in Drosophila. We postulated that the aRC enzymes might be deployed to alleviate pathological stresses arising from mitochondrial dysfunction in a wide variety of disease states. However, before such therapies can be contemplated, it is essential to understand the effects of aRC enzymes on cell metabolism and organismal physiology. Here we report and discuss new findings that shed light on the functions of the aRC enzymes in animals, and the unexpected benefits and detriments that they confer on model organisms. In Ciona intestinalis, the aRC is induced by hypoxia and by sulfide, but is unresponsive to other environmental stressors. When expressed in Drosophila, AOX results in impaired survival under restricted nutrition, in addition to the previously reported male reproductive anomalies. In contrast, it confers cold resistance to developing and adult flies, and counteracts cell signaling defects that underlie developmental dysmorphologies. The aRC enzymes may also influence lifespan and stress resistance more generally, by eliciting or interfering with hormetic mechanisms. In sum, their judicious use may lead to major benefits in medicine, but this will require a thorough characterization of their properties and physiological effects.
Collapse
|
59
|
Fedor JG, Hirst J. Mitochondrial Supercomplexes Do Not Enhance Catalysis by Quinone Channeling. Cell Metab 2018; 28:525-531.e4. [PMID: 29937372 PMCID: PMC6125145 DOI: 10.1016/j.cmet.2018.05.024] [Citation(s) in RCA: 92] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Revised: 05/14/2018] [Accepted: 05/24/2018] [Indexed: 12/12/2022]
Abstract
Mitochondrial respiratory supercomplexes, comprising complexes I, III, and IV, are the minimal functional units of the electron transport chain. Assembling the individual complexes into supercomplexes may stabilize them, provide greater spatiotemporal control of respiration, or, controversially, confer kinetic advantages through the sequestration of local quinone and cytochrome c pools (substrate channeling). Here, we have incorporated an alternative quinol oxidase (AOX) into mammalian heart mitochondrial membranes to introduce a competing pathway for quinol oxidation and test for channeling. AOX substantially increases the rate of NADH oxidation by O2 without affecting the membrane integrity, the supercomplexes, or NADH-linked oxidative phosphorylation. Therefore, the quinol generated in supercomplexes by complex I is reoxidized more rapidly outside the supercomplex by AOX than inside the supercomplex by complex III. Our results demonstrate that quinone and quinol diffuse freely in and out of supercomplexes: substrate channeling does not occur and is not required to support respiration.
Collapse
Affiliation(s)
- Justin G Fedor
- The Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Wellcome Trust/MRC Building, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0XY, UK
| | - Judy Hirst
- The Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Wellcome Trust/MRC Building, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0XY, UK.
| |
Collapse
|
60
|
Emerging therapies for mitochondrial diseases. Essays Biochem 2018; 62:467-481. [PMID: 29980632 DOI: 10.1042/ebc20170114] [Citation(s) in RCA: 96] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Revised: 05/20/2018] [Accepted: 05/23/2018] [Indexed: 12/25/2022]
Abstract
For the vast majority of patients with mitochondrial diseases, only supportive and symptomatic therapies are available. However, in the last decade, due to extraordinary advances in defining the causes and pathomechanisms of these diverse disorders, new therapies are being developed in the laboratory and are entering human clinical trials. In this review, we highlight the current use of dietary supplement and exercise therapies as well as emerging therapies that may be broadly applicable across multiple mitochondrial diseases or tailored for specific disorders. Examples of non-tailored therapeutic targets include: activation of mitochondrial biogenesis, regulation of mitophagy and mitochondrial dynamics, bypass of biochemical defects, mitochondrial replacement therapy, and hypoxia. In contrast, tailored therapies are: scavenging of toxic compounds, deoxynucleoside and deoxynucleotide treatments, cell replacement therapies, gene therapy, shifting mitochondrial DNA mutation heteroplasmy, and stabilization of mutant mitochondrial transfer RNAs.
Collapse
|
61
|
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.
Collapse
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.
| |
Collapse
|
62
|
Robb EL, Hall AR, Prime TA, Eaton S, Szibor M, Viscomi C, James AM, Murphy MP. Control of mitochondrial superoxide production by reverse electron transport at complex I. J Biol Chem 2018; 293:9869-9879. [PMID: 29743240 PMCID: PMC6016480 DOI: 10.1074/jbc.ra118.003647] [Citation(s) in RCA: 194] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Revised: 05/08/2018] [Indexed: 12/17/2022] Open
Abstract
The generation of mitochondrial superoxide (O2̇̄) by reverse electron transport (RET) at complex I causes oxidative damage in pathologies such as ischemia reperfusion injury, but also provides the precursor to H2O2 production in physiological mitochondrial redox signaling. Here, we quantified the factors that determine mitochondrial O2̇̄ production by RET in isolated heart mitochondria. Measuring mitochondrial H2O2 production at a range of proton-motive force (Δp) values and for several coenzyme Q (CoQ) and NADH pool redox states obtained with the uncoupler p-trifluoromethoxyphenylhydrazone, we show that O2̇̄ production by RET responds to changes in O2 concentration, the magnitude of Δp, and the redox states of the CoQ and NADH pools. Moreover, we determined how expressing the alternative oxidase from the tunicate Ciona intestinalis to oxidize the CoQ pool affected RET-mediated O2̇̄ production at complex I, underscoring the importance of the CoQ pool for mitochondrial O2̇̄ production by RET. An analysis of O2̇̄ production at complex I as a function of the thermodynamic forces driving RET at complex I revealed that many molecules that affect mitochondrial reactive oxygen species production do so by altering the overall thermodynamic driving forces of RET, rather than by directly acting on complex I. These findings clarify the factors controlling RET-mediated mitochondrial O2̇̄ production in both pathological and physiological conditions. We conclude that O2̇̄ production by RET is highly responsive to small changes in Δp and the CoQ redox state, indicating that complex I RET represents a major mode of mitochondrial redox signaling.
Collapse
Affiliation(s)
- Ellen L Robb
- From the Medical Research Council Mitochondrial Biology Unit, Hills Road, University of Cambridge, Cambridge CB2 0XY, United Kingdom
| | - Andrew R Hall
- From the Medical Research Council Mitochondrial Biology Unit, Hills Road, University of Cambridge, Cambridge CB2 0XY, United Kingdom
| | - Tracy A Prime
- From the Medical Research Council Mitochondrial Biology Unit, Hills Road, University of Cambridge, Cambridge CB2 0XY, United Kingdom
| | - Simon Eaton
- the UCL Great Ormond Street Institute of Child Health, London WC1N 1EH, United Kingdom
| | - Marten Szibor
- the Faculty of Medicine and Life Sciences, University of Tampere, Tampere FI-33014, Finland, and
- the Max-Planck-Institute for Heart and Lung Research, Ludwigstrasse 43, 61231 Bad Nauheim, Germany
| | - Carlo Viscomi
- From the Medical Research Council Mitochondrial Biology Unit, Hills Road, University of Cambridge, Cambridge CB2 0XY, United Kingdom
| | - Andrew M James
- From the Medical Research Council Mitochondrial Biology Unit, Hills Road, University of Cambridge, Cambridge CB2 0XY, United Kingdom
| | - Michael P Murphy
- From the Medical Research Council Mitochondrial Biology Unit, Hills Road, University of Cambridge, Cambridge CB2 0XY, United Kingdom,
| |
Collapse
|
63
|
Racca S, Welchen E, Gras DE, Tarkowská D, Turečková V, Maurino VG, Gonzalez DH. Interplay between cytochrome c and gibberellins during Arabidopsis vegetative development. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2018; 94:105-121. [PMID: 29385297 DOI: 10.1111/tpj.13845] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Revised: 01/04/2018] [Accepted: 01/15/2018] [Indexed: 05/18/2023]
Abstract
We studied the effect of reducing the levels of the mitochondrial electron carrier cytochrome c (CYTc) in Arabidopsis thaliana. Plants with CYTc deficiency have delayed growth and development, and reach flowering several days later than the wild-type but with the same number of leaves. CYTc-deficient plants accumulate starch and glucose during the day, and contain lower levels of active gibberellins (GA) and higher levels of DELLA proteins, involved in GA signaling. GA treatment abolishes the developmental delay and reduces glucose accumulation in CYTc-deficient plants, which also show a lower raise in ATP levels in response to glucose. Treatment of wild-type plants with inhibitors of mitochondrial energy production limits plant growth and increases the levels of DELLA proteins, thus mimicking the effects of CYTc deficiency. In addition, an increase in the amount of CYTc decreases DELLA protein levels and expedites growth, and this depends on active GA synthesis. We conclude that CYTc levels impinge on the activity of the GA pathway, most likely through changes in mitochondrial energy production. In this way, hormone-dependent growth would be coupled to the activity of components of the mitochondrial respiratory chain.
Collapse
Affiliation(s)
- Sofía Racca
- Instituto de Agrobiotecnología del Litoral (CONICET-UNL), Cátedra de Biología Celular y Molecular, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, 3000, Santa Fe, Argentina
| | - Elina Welchen
- Instituto de Agrobiotecnología del Litoral (CONICET-UNL), Cátedra de Biología Celular y Molecular, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, 3000, Santa Fe, Argentina
| | - Diana E Gras
- Instituto de Agrobiotecnología del Litoral (CONICET-UNL), Cátedra de Biología Celular y Molecular, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, 3000, Santa Fe, Argentina
| | - Danuše Tarkowská
- Laboratory of Growth Regulators, Centre of the Region Haná for Biotechnological and Agricultural Research, Institute of Experimental Botany AS CR, Faculty of Science, Palacký University, Šlechtitelů 27, CZ-78371, Olomouc, Czech Republic
| | - Veronika Turečková
- Laboratory of Growth Regulators, Centre of the Region Haná for Biotechnological and Agricultural Research, Institute of Experimental Botany AS CR, Faculty of Science, Palacký University, Šlechtitelů 27, CZ-78371, Olomouc, Czech Republic
| | - Veronica G Maurino
- Institute of Developmental and Molecular Biology of Plants, Plant Molecular Physiology and Biotechnology Group, Heinrich-Heine-Universität, Universitätsstraße 1, 40225, Düsseldorf, Germany
- Cluster of Excellence on Plant Sciences (CEPLAS), 40225, Düsseldorf, Germany
| | - Daniel H Gonzalez
- Instituto de Agrobiotecnología del Litoral (CONICET-UNL), Cátedra de Biología Celular y Molecular, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, 3000, Santa Fe, Argentina
| |
Collapse
|
64
|
Liu X, Salokas K, Tamene F, Jiu Y, Weldatsadik RG, Öhman T, Varjosalo M. An AP-MS- and BioID-compatible MAC-tag enables comprehensive mapping of protein interactions and subcellular localizations. Nat Commun 2018; 9:1188. [PMID: 29568061 PMCID: PMC5864832 DOI: 10.1038/s41467-018-03523-2] [Citation(s) in RCA: 154] [Impact Index Per Article: 25.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Accepted: 02/21/2018] [Indexed: 11/09/2022] Open
Abstract
Protein-protein interactions govern almost all cellular functions. These complex networks of stable and transient associations can be mapped by affinity purification mass spectrometry (AP-MS) and complementary proximity-based labeling methods such as BioID. To exploit the advantages of both strategies, we here design and optimize an integrated approach combining AP-MS and BioID in a single construct, which we term MAC-tag. We systematically apply the MAC-tag approach to 18 subcellular and 3 sub-organelle localization markers, generating a molecular context database, which can be used to define a protein’s molecular location. In addition, we show that combining the AP-MS and BioID results makes it possible to obtain interaction distances within a protein complex. Taken together, our integrated strategy enables the comprehensive mapping of the physical and functional interactions of proteins, defining their molecular context and improving our understanding of the cellular interactome. AP-MS and BioID provide complementary insights into cellular protein interaction networks. To facilitate their combined use, the authors here present an AP-MS- and BioID-compatible affinity tag, enabling efficient determination of cellular protein locations and interaction distances.
Collapse
Affiliation(s)
- Xiaonan Liu
- Institute of Biotechnology, University of Helsinki, Helsinki, 00014, Finland.,Helsinki Institute of Life Science, University of Helsinki, Helsinki, 00014, Finland
| | - Kari Salokas
- Institute of Biotechnology, University of Helsinki, Helsinki, 00014, Finland.,Helsinki Institute of Life Science, University of Helsinki, Helsinki, 00014, Finland
| | - Fitsum Tamene
- Institute of Biotechnology, University of Helsinki, Helsinki, 00014, Finland.,Helsinki Institute of Life Science, University of Helsinki, Helsinki, 00014, Finland.,Proteomics Unit, University of Helsinki, Helsinki, 00014, Finland
| | - Yaming Jiu
- Institute of Biotechnology, University of Helsinki, Helsinki, 00014, Finland.,Helsinki Institute of Life Science, University of Helsinki, Helsinki, 00014, Finland
| | - Rigbe G Weldatsadik
- Institute of Biotechnology, University of Helsinki, Helsinki, 00014, Finland.,Helsinki Institute of Life Science, University of Helsinki, Helsinki, 00014, Finland.,Proteomics Unit, University of Helsinki, Helsinki, 00014, Finland
| | - Tiina Öhman
- Institute of Biotechnology, University of Helsinki, Helsinki, 00014, Finland.,Helsinki Institute of Life Science, University of Helsinki, Helsinki, 00014, Finland.,Proteomics Unit, University of Helsinki, Helsinki, 00014, Finland
| | - Markku Varjosalo
- Institute of Biotechnology, University of Helsinki, Helsinki, 00014, Finland. .,Helsinki Institute of Life Science, University of Helsinki, Helsinki, 00014, Finland. .,Proteomics Unit, University of Helsinki, Helsinki, 00014, Finland.
| |
Collapse
|
65
|
Camargo AF, Chioda MM, Rodrigues APC, Garcia GS, McKinney EA, Jacobs HT, Oliveira MT. Xenotopic expression of alternative electron transport enzymes in animal mitochondria and their impact in health and disease. Cell Biol Int 2018; 42:664-669. [PMID: 29384231 DOI: 10.1002/cbin.10943] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Accepted: 01/27/2018] [Indexed: 12/22/2022]
Abstract
The mitochondrial respiratory chain in vertebrates and arthropods is different from that of most other eukaryotes because they lack alternative enzymes that provide electron transfer pathways additional to the oxidative phosphorylation (OXPHOS) system. However, the use of diverse experimental models, such as human cells in culture, Drosophila melanogaster and the mouse, has demonstrated that the transgenic expression of these alternative enzymes can impact positively many phenotypes associated with human mitochondrial and other cellular dysfunction, including those typically presented in complex IV deficiencies, Parkinson's, and Alzheimer's. In addition, these enzymes have recently provided extremely valuable data on how, when, and where reactive oxygen species, considered by many as "by-products" of OXPHOS, can contribute to animal longevity. It has also been shown that the expression of the alternative enzymes is thermogenic in cultured cells, causes reproductive defects in flies, and enhances the deleterious phenotype of some mitochondrial disease models. Therefore, all the reported beneficial effects must be considered with caution, as these enzymes have been proposed to be deployed in putative gene therapies to treat human diseases. Here, we present a brief review of the scientific data accumulated over the past decade that show the benefits and the risks of introducing alternative branches of the electron transport into mammalian and insect mitochondria, and we provide a perspective on the future of this research field.
Collapse
Affiliation(s)
- André F Camargo
- Departamento de Tecnologia, Faculdade de Ciências Agrárias e Veterinárias, Universidade Estadual Paulista "Júlio de Mesquita Filho", Via de Acesso Prof. Paulo Donato Castellane, s/n, 14884-900, Jaboticabal, SP, Brazil
| | - Marina M Chioda
- Departamento de Tecnologia, Faculdade de Ciências Agrárias e Veterinárias, Universidade Estadual Paulista "Júlio de Mesquita Filho", Via de Acesso Prof. Paulo Donato Castellane, s/n, 14884-900, Jaboticabal, SP, Brazil
| | - Ana P C Rodrigues
- Departamento de Tecnologia, Faculdade de Ciências Agrárias e Veterinárias, Universidade Estadual Paulista "Júlio de Mesquita Filho", Via de Acesso Prof. Paulo Donato Castellane, s/n, 14884-900, Jaboticabal, SP, Brazil
| | - Geovana S Garcia
- Departamento de Tecnologia, Faculdade de Ciências Agrárias e Veterinárias, Universidade Estadual Paulista "Júlio de Mesquita Filho", Via de Acesso Prof. Paulo Donato Castellane, s/n, 14884-900, Jaboticabal, SP, Brazil
| | - Emily A McKinney
- Departamento de Tecnologia, Faculdade de Ciências Agrárias e Veterinárias, Universidade Estadual Paulista "Júlio de Mesquita Filho", Via de Acesso Prof. Paulo Donato Castellane, s/n, 14884-900, Jaboticabal, SP, Brazil
| | - Howard T Jacobs
- Institute of Biosciences and Medical Technology and Tampere University Hospital, FI-33014 University of Tampere, Tampere, Finland.,Institute of Biotechnology, FI-00014 University of Helsinki, Helsinki, Finland
| | - Marcos T Oliveira
- Departamento de Tecnologia, Faculdade de Ciências Agrárias e Veterinárias, Universidade Estadual Paulista "Júlio de Mesquita Filho", Via de Acesso Prof. Paulo Donato Castellane, s/n, 14884-900, Jaboticabal, SP, Brazil
| |
Collapse
|
66
|
Kubrak OI, Lushchak OV, Zandawala M, Nässel DR. Systemic corazonin signalling modulates stress responses and metabolism in Drosophila. Open Biol 2017; 6:rsob.160152. [PMID: 27810969 PMCID: PMC5133436 DOI: 10.1098/rsob.160152] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Accepted: 10/05/2016] [Indexed: 12/20/2022] Open
Abstract
Stress triggers cellular and systemic reactions in organisms to restore homeostasis. For instance, metabolic stress, experienced during starvation, elicits a hormonal response that reallocates resources to enable food search and readjustment of physiology. Mammalian gonadotropin-releasing hormone (GnRH) and its insect orthologue, adipokinetic hormone (AKH), are known for their roles in modulating stress-related behaviour. Here we show that corazonin (Crz), a peptide homologous to AKH/GnRH, also alters stress physiology in Drosophila. The Crz receptor (CrzR) is expressed in salivary glands and adipocytes of the liver-like fat body, and CrzR knockdown targeted simultaneously to both these tissues increases the fly's resistance to starvation, desiccation and oxidative stress, reduces feeding, alters expression of transcripts of Drosophila insulin-like peptides (DILPs), and affects gene expression in the fat body. Furthermore, in starved flies, CrzR-knockdown increases circulating and stored carbohydrates. Thus, our findings indicate that elevated systemic Crz signalling during stress coordinates increased food intake and diminished energy stores to regain metabolic homeostasis. Our study suggests that an ancient stress-peptide in Urbilateria evolved to give rise to present-day GnRH, AKH and Crz signalling systems.
Collapse
Affiliation(s)
- Olga I Kubrak
- Department of Zoology, Stockholm University, 10691 Stockholm, Sweden
| | - Oleh V Lushchak
- Department of Zoology, Stockholm University, 10691 Stockholm, Sweden
| | - Meet Zandawala
- Department of Zoology, Stockholm University, 10691 Stockholm, Sweden
| | - Dick R Nässel
- Department of Zoology, Stockholm University, 10691 Stockholm, Sweden
| |
Collapse
|
67
|
Structural insights into the alternative oxidases: are all oxidases made equal? Biochem Soc Trans 2017; 45:731-740. [PMID: 28620034 DOI: 10.1042/bst20160178] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Revised: 03/08/2017] [Accepted: 03/10/2017] [Indexed: 01/15/2023]
Abstract
The alternative oxidases (AOXs) are ubiquinol-oxidoreductases that are members of the diiron carboxylate superfamily. They are not only ubiquitously distributed within the plant kingdom but also found in increasing numbers within the fungal, protist, animal and prokaryotic kingdoms. Although functions of AOXs are highly diverse in general, they tend to play key roles in thermogenesis, stress tolerance (through the management of radical oxygen species) and the maintenance of mitochondrial and cellular energy homeostasis. The best structurally characterised AOX is from Trypanosoma brucei In this review, we compare the structure of AOXs, created using homology modelling, from many important species in an attempt to explain differences in activity and sensitivity to AOX inhibitors. We discuss the implications of these findings not only for future structure-based drug design but also for the design of novel AOXs for gene therapy.
Collapse
|
68
|
Toward a therapy for mitochondrial disease. Biochem Soc Trans 2017; 44:1483-1490. [PMID: 27911730 PMCID: PMC5095900 DOI: 10.1042/bst20160085] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Revised: 06/14/2016] [Accepted: 06/28/2016] [Indexed: 01/08/2023]
Abstract
Mitochondrial disorders are a group of genetic diseases affecting the energy-converting process of oxidative phosphorylation. The extreme variability of symptoms, organ involvement, and clinical course represent a challenge to the development of effective therapeutic interventions. However, new possibilities have recently been emerging from studies in model organisms and awaiting verification in humans. I will discuss here the most promising experimental approaches and the challenges we face to translate them into the clinics. The current clinical trials will also be briefly reviewed.
Collapse
|
69
|
Saari S, Andjelković A, Garcia GS, Jacobs HT, Oliveira MT. Expression of Ciona intestinalis AOX causes male reproductive defects in Drosophila melanogaster. BMC DEVELOPMENTAL BIOLOGY 2017; 17:9. [PMID: 28673232 PMCID: PMC5496232 DOI: 10.1186/s12861-017-0151-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/06/2017] [Accepted: 06/14/2017] [Indexed: 02/08/2023]
Abstract
Background Mitochondrial alternative respiratory-chain enzymes are phylogenetically widespread, and buffer stresses affecting oxidative phosphorylation in species that possess them. However, they have been lost in the evolutionary lineages leading to vertebrates and arthropods, raising the question as to what survival or reproductive disadvantages they confer. Recent interest in using them in therapy lends a biomedical dimension to this question. Methods Here, we examined the impact of the expression of Ciona intestinalis alternative oxidase, AOX, on the reproductive success of Drosophila melanogaster males. Sperm-competition assays were performed between flies carrying three copies of a ubiquitously expressed AOX construct, driven by the α-tubulin promoter, and wild-type males of the same genetic background. Results In sperm-competition assays, AOX conferred a substantial disadvantage, associated with decreased production of mature sperm. Sperm differentiation appeared to proceed until the last stages, but was spatially deranged, with spermatozoids retained in the testis instead of being released to the seminal vesicle. High AOX expression was detected in the outermost cell-layer of the testis sheath, which we hypothesize may disrupt a signal required for sperm maturation. Conclusions AOX expression in Drosophila thus has effects that are deleterious to male reproductive function. Our results imply that AOX therapy must be developed with caution. Electronic supplementary material The online version of this article (doi:10.1186/s12861-017-0151-3) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Sina Saari
- Institute of Biosciences and Medical Technology, Tampere University Hospital, University of Tampere, FI-33014, Tampere, Finland
| | - Ana Andjelković
- Institute of Biosciences and Medical Technology, Tampere University Hospital, University of Tampere, FI-33014, Tampere, Finland
| | - Geovana S Garcia
- Departamento de Tecnologia, Faculdade de Ciências Agrárias e Veterinárias, Universidade Estadual Paulista "Júlio de Mesquita Filho", Jaboticabal, SP, 14884-900, Brazil
| | - Howard T Jacobs
- Institute of Biosciences and Medical Technology, Tampere University Hospital, University of Tampere, FI-33014, Tampere, Finland. .,Institute of Biotechnology, University of Helsinki, FI-00014, Helsinki, Finland.
| | - Marcos T Oliveira
- Institute of Biosciences and Medical Technology, Tampere University Hospital, University of Tampere, FI-33014, Tampere, Finland.,Departamento de Tecnologia, Faculdade de Ciências Agrárias e Veterinárias, Universidade Estadual Paulista "Júlio de Mesquita Filho", Jaboticabal, SP, 14884-900, Brazil
| |
Collapse
|
70
|
Logan A, Murphy MP. Using chemical biology to assess and modulate mitochondria: progress and challenges. Interface Focus 2017; 7:20160151. [PMID: 28382206 PMCID: PMC5311910 DOI: 10.1098/rsfs.2016.0151] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Our understanding of the role of mitochondria in biomedical sciences has expanded considerably over the past decade. In addition to their well-known metabolic roles, mitochondrial are also central to signalling for various processes through the generation of signals such as ROS and metabolites that affect cellular homeostasis, as well as other processes such as cell death and inflammation. Thus, mitochondrial function and dysfunction are central to the health and fate of the cell. Consequently, there is considerable interest in better understanding and assessing the many roles of mitochondria. Furthermore, there is also a growing realization that mitochondrial are a promising drug target in a wide range of pathologies. The application of interdisciplinary approaches at the interface between chemistry and biology are opening up new opportunities to understand mitochondrial function and in assessing the role of the organelle in biology. This work and the experience thus gained are leading to the development of new classes of therapies. Here, we overview the progress that has been made to date on exploring the chemical biology of the organelle and then focus on future challenges and opportunities that face this rapidly developing field.
Collapse
Affiliation(s)
- Angela Logan
- MRC Mitochondrial Biology Unit , Hills Road, Cambridge CB2 0XY , UK
| | - Michael P Murphy
- MRC Mitochondrial Biology Unit , Hills Road, Cambridge CB2 0XY , UK
| |
Collapse
|
71
|
Szibor M, Dhandapani PK, Dufour E, Holmström KM, Zhuang Y, Salwig I, Wittig I, Heidler J, Gizatullina Z, Gainutdinov T, Fuchs H, Gailus-Durner V, de Angelis MH, Nandania J, Velagapudi V, Wietelmann A, Rustin P, Gellerich FN, Jacobs HT, Braun T. Broad AOX expression in a genetically tractable mouse model does not disturb normal physiology. Dis Model Mech 2017; 10:163-171. [PMID: 28067626 PMCID: PMC5312010 DOI: 10.1242/dmm.027839] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Accepted: 11/30/2016] [Indexed: 01/01/2023] Open
Abstract
Plants and many lower organisms, but not mammals, express alternative oxidases (AOXs) that branch the mitochondrial respiratory chain, transferring electrons directly from ubiquinol to oxygen without proton pumping. Thus, they maintain electron flow under conditions when the classical respiratory chain is impaired, limiting excess production of oxygen radicals and supporting redox and metabolic homeostasis. AOX from Ciona intestinalis has been used to study and mitigate mitochondrial impairments in mammalian cell lines, Drosophila disease models and, most recently, in the mouse, where multiple lentivector-AOX transgenes conferred substantial expression in specific tissues. Here, we describe a genetically tractable mouse model in which Ciona AOX has been targeted to the Rosa26 locus for ubiquitous expression. The AOXRosa26 mouse exhibited only subtle phenotypic effects on respiratory complex formation, oxygen consumption or the global metabolome, and showed an essentially normal physiology. AOX conferred robust resistance to inhibitors of the respiratory chain in organello; moreover, animals exposed to a systemically applied LD50 dose of cyanide did not succumb. The AOXRosa26 mouse is a useful tool to investigate respiratory control mechanisms and to decipher mitochondrial disease aetiology in vivo.
Collapse
Affiliation(s)
- Marten Szibor
- Institute of Biotechnology, FI-00014 University of Helsinki, Finland
- BioMediTech and Tampere University Hospital, FI-33014 University of Tampere, Finland
- Max Planck Institute for Heart and Lung Research, Cardiac Development and Remodelling (Department I), Bad Nauheim D-61231, Germany
| | - Praveen K Dhandapani
- Institute of Biotechnology, FI-00014 University of Helsinki, Finland
- BioMediTech and Tampere University Hospital, FI-33014 University of Tampere, Finland
| | - Eric Dufour
- BioMediTech and Tampere University Hospital, FI-33014 University of Tampere, Finland
| | - Kira M Holmström
- Institute of Biotechnology, FI-00014 University of Helsinki, Finland
- BioMediTech and Tampere University Hospital, FI-33014 University of Tampere, Finland
| | - Yuan Zhuang
- Institute of Biotechnology, FI-00014 University of Helsinki, Finland
| | - Isabelle Salwig
- Max Planck Institute for Heart and Lung Research, Cardiac Development and Remodelling (Department I), Bad Nauheim D-61231, Germany
| | - Ilka Wittig
- Functional Proteomics, SFB 815 Core Unit, Faculty of Medicine, Goethe-University, Frankfurt am Main D-60590, Germany
- German Center of Cardiovascular Research (DZHK), Partner site RheinMain, Frankfurt, Germany
- Cluster of Excellence "Macromolecular Complexes", Goethe-University, Frankfurt am Main D-60590, Germany
| | - Juliana Heidler
- Functional Proteomics, SFB 815 Core Unit, Faculty of Medicine, Goethe-University, Frankfurt am Main D-60590, Germany
| | | | | | - Helmut Fuchs
- German Mouse Clinic, Institute of Experimental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health GmbH, Ingolstaedter Landstrasse 1, Neuherberg 85764, Germany
| | - Valérie Gailus-Durner
- German Mouse Clinic, Institute of Experimental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health GmbH, Ingolstaedter Landstrasse 1, Neuherberg 85764, Germany
| | - Martin Hrabě de Angelis
- German Mouse Clinic, Institute of Experimental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health GmbH, Ingolstaedter Landstrasse 1, Neuherberg 85764, Germany
- Chair of Experimental Genetics, Center of Life and Food Sciences Weihenstephan, TU Munich, Emil-Erlenmeyer-Forum 2, Freising-Weihenstephan 85350, Germany
- Member of German Center for Diabetes Research (DZD), Ingolstaedter Landstrasse 1, Neuherberg 85764, Germany
| | - Jatin Nandania
- Institute for Molecular Medicine Finland, FI-00014 University of Helsinki, Finland
| | - Vidya Velagapudi
- Institute for Molecular Medicine Finland, FI-00014 University of Helsinki, Finland
| | - Astrid Wietelmann
- Max Planck Institute for Heart and Lung Research, Cardiac Development and Remodelling (Department I), Bad Nauheim D-61231, Germany
| | - Pierre Rustin
- INSERM UMR 1141 and Université Paris 7, Hôpital Robert Debré, Paris 75019, France
| | - Frank N Gellerich
- Leibniz Institute for Neurobiology, Magdeburg D-39118, Germany
- Department of Neurology, Otto-von-Guericke-University, Magdeburg D-39120, Germany
| | - Howard T Jacobs
- Institute of Biotechnology, FI-00014 University of Helsinki, Finland
- BioMediTech and Tampere University Hospital, FI-33014 University of Tampere, Finland
| | - Thomas Braun
- Max Planck Institute for Heart and Lung Research, Cardiac Development and Remodelling (Department I), Bad Nauheim D-61231, Germany
| |
Collapse
|
72
|
Heterologous expression of the Crassostrea gigas (Pacific oyster) alternative oxidase in the yeast Saccharomyces cerevisiae. J Bioenerg Biomembr 2016; 48:509-520. [PMID: 27816999 DOI: 10.1007/s10863-016-9685-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Accepted: 10/25/2016] [Indexed: 12/17/2022]
Abstract
Alternative oxidase (AOX) is a terminal oxidase within the inner mitochondrial membrane (IMM) present in many organisms where it functions in the electron transport system (ETS). AOX directly accepts electrons from ubiquinol and is therefore capable of bypassing ETS Complexes III and IV. The human genome does not contain a gene coding for AOX, so AOX expression has been suggested as a gene therapy for a range of human mitochondrial diseases caused by genetic mutations that render Complex III and/or IV dysfunctional. An effective means of screening mutations amenable to AOX treatment remains to be devised. We have generated such a tool by heterologously expressing AOX from the Pacific oyster (Crassostrea gigas) in the yeast Saccharomyces cerevisiae under the control of a galactose promoter. Our results show that this animal AOX is monomeric and is correctly targeted to yeast mitochondria. Moreover, when expressed in yeast, Pacific oyster AOX is a functional quinol oxidase, conferring cyanide-resistant growth and myxothiazol-resistant oxygen consumption to yeast cells and isolated mitochondria. This system represents a high-throughput screening tool for determining which Complex III and IV genetic mutations in yeast will be amenable to AOX gene therapy. As many human genes are orthologous to those found in yeast, our invention represents an efficient and cost-effective way to evaluate viable research avenues. In addition, this system provides the opportunity to learn more about the localization, structure, and regulation of AOXs from animals that are not easily reared or manipulated in the lab.
Collapse
|
73
|
Mills EL, Kelly B, Logan A, Costa ASH, Varma M, Bryant CE, Tourlomousis P, Däbritz JHM, Gottlieb E, Latorre I, Corr SC, McManus G, Ryan D, Jacobs HT, Szibor M, Xavier RJ, Braun T, Frezza C, Murphy MP, O'Neill LA. Succinate Dehydrogenase Supports Metabolic Repurposing of Mitochondria to Drive Inflammatory Macrophages. Cell 2016; 167:457-470.e13. [PMID: 27667687 PMCID: PMC5863951 DOI: 10.1016/j.cell.2016.08.064] [Citation(s) in RCA: 1362] [Impact Index Per Article: 170.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Revised: 07/20/2016] [Accepted: 08/25/2016] [Indexed: 12/13/2022]
Abstract
Activated macrophages undergo metabolic reprogramming, which drives their pro-inflammatory phenotype, but the mechanistic basis for this remains obscure. Here, we demonstrate that upon lipopolysaccharide (LPS) stimulation, macrophages shift from producing ATP by oxidative phosphorylation to glycolysis while also increasing succinate levels. We show that increased mitochondrial oxidation of succinate via succinate dehydrogenase (SDH) and an elevation of mitochondrial membrane potential combine to drive mitochondrial reactive oxygen species (ROS) production. RNA sequencing reveals that this combination induces a pro-inflammatory gene expression profile, while an inhibitor of succinate oxidation, dimethyl malonate (DMM), promotes an anti-inflammatory outcome. Blocking ROS production with rotenone by uncoupling mitochondria or by expressing the alternative oxidase (AOX) inhibits this inflammatory phenotype, with AOX protecting mice from LPS lethality. The metabolic alterations that occur upon activation of macrophages therefore repurpose mitochondria from ATP synthesis to ROS production in order to promote a pro-inflammatory state.
Collapse
Affiliation(s)
- Evanna L Mills
- School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin 2, Ireland
| | - Beth Kelly
- School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin 2, Ireland
| | - Angela Logan
- MRC Mitochondrial Biology Unit, Hills Road, Cambridge CB2 0XY, UK
| | - Ana S H Costa
- MRC Cancer Unit, University of Cambridge, Hutchison/MRC Research Centre, Box 197, Cambridge Biomedical Campus, Cambridge CB2 0XZ, UK
| | - Mukund Varma
- Center for Computational and Integrative Biology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA
| | - Clare E Bryant
- Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge CB23 8AQ, UK
| | - Panagiotis Tourlomousis
- Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge CB23 8AQ, UK
| | - J Henry M Däbritz
- Cancer Metabolism Research Unit, Cancer Research UK, Beatson Institute, Garscube Estate, Switchback Road, Bearsden, Glasgow G61 1BD, UK
| | - Eyal Gottlieb
- Cancer Metabolism Research Unit, Cancer Research UK, Beatson Institute, Garscube Estate, Switchback Road, Bearsden, Glasgow G61 1BD, UK
| | - Isabel Latorre
- Center for Computational and Integrative Biology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA
| | - Sinéad C Corr
- Department of Microbiology, Moyne Institute for Preventative Medicine, School of Genetics and Microbiology, Trinity College Dublin, Dublin 2, Ireland
| | - Gavin McManus
- School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin 2, Ireland
| | - Dylan Ryan
- School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin 2, Ireland
| | - Howard T Jacobs
- Institute of Biotechnology, 00014 University of Helsinki, P.O. Box 56, Helsinki 00014, Finland; BioMediTech and Tampere University Hospital, University of Tampere, Tampere 33014, Finland
| | - Marten Szibor
- Institute of Biotechnology, 00014 University of Helsinki, P.O. Box 56, Helsinki 00014, Finland; BioMediTech and Tampere University Hospital, University of Tampere, Tampere 33014, Finland; Max-Planck-Institute for Heart and Lung Research, Ludwigstrasse 43, 61231 Bad Nauheim, Germany
| | - Ramnik J Xavier
- Center for Computational and Integrative Biology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA; Gastrointestinal Unit, Center for the Study of Inflammatory Bowel Disease, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA
| | - Thomas Braun
- Max-Planck-Institute for Heart and Lung Research, Ludwigstrasse 43, 61231 Bad Nauheim, Germany
| | - Christian Frezza
- MRC Cancer Unit, University of Cambridge, Hutchison/MRC Research Centre, Box 197, Cambridge Biomedical Campus, Cambridge CB2 0XZ, UK
| | - Michael P Murphy
- MRC Mitochondrial Biology Unit, Hills Road, Cambridge CB2 0XY, UK.
| | - Luke A O'Neill
- School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin 2, Ireland.
| |
Collapse
|
74
|
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.
Collapse
|
75
|
Practical Recommendations for the Use of the GeneSwitch Gal4 System to Knock-Down Genes in Drosophila melanogaster. PLoS One 2016; 11:e0161817. [PMID: 27570965 PMCID: PMC5003377 DOI: 10.1371/journal.pone.0161817] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Accepted: 08/13/2016] [Indexed: 12/02/2022] Open
Abstract
Drosophila melanogaster is a popular research model organism thanks to its’ powerful genetic tools that allow spatial and temporal control of gene expression. The inducible GeneSwitch Gal4 system (GS) system is a modified version of the classic UAS/GAL4 system which allows inducible regulation of gene expression and eliminates background effects. It is widely acknowledged that the GS system is leaky, with low level expression of UAS transgenes in absence of the inducer RU-486 (the progesterone analog that activates the modified GAL4 protein). However, in the course of our experiments, we have observed that the extent of this leak depends on the nature of the transgene being expressed. In the absence of RU-486, when strong drivers are used to express protein coding transgenes, leaky expression is low or negligible, however expression of RNA interference (RNAi) transgenes results in complete depletion of protein levels. The majority of published studies, using the GS system and RNAi transgenes validate knock-down efficiency by comparing target gene mRNA levels between induced and non-induced groups. Here, we demonstrate that this approach is lacking and that both additional control groups and further validation is required at the protein level. Unfortunately, this experimental limitation of the GS system eliminates “the background advantage”, but does offer the possibility of performing more complex experiments (e.g. studying depletion and overexpression of different proteins in the same genetic background). The limitations and new possible applications of the GS system are discussed in detail.
Collapse
|
76
|
El-Khoury R, Kaulio E, Lassila KA, Crowther DC, Jacobs HT, Rustin P. Expression of the alternative oxidase mitigates beta-amyloid production and toxicity in model systems. Free Radic Biol Med 2016; 96:57-66. [PMID: 27094492 DOI: 10.1016/j.freeradbiomed.2016.04.006] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Revised: 04/05/2016] [Accepted: 04/09/2016] [Indexed: 12/13/2022]
Abstract
Mitochondrial dysfunction has been widely associated with the pathology of Alzheimer's disease, but there is no consensus on whether it is a cause or consequence of disease, nor on the precise mechanism(s). We addressed these issues by testing the effects of expressing the alternative oxidase AOX from Ciona intestinalis, in different models of AD pathology. AOX can restore respiratory electron flow when the cytochrome segment of the mitochondrial respiratory chain is inhibited, supporting ATP synthesis, maintaining cellular redox homeostasis and mitigating excess superoxide production at respiratory complexes I and III. In human HEK293-derived cells, AOX expression decreased the production of beta-amyloid peptide resulting from antimycin inhibition of respiratory complex III. Because hydrogen peroxide was neither a direct product nor substrate of AOX, the ability of AOX to mimic antioxidants in this assay must be indirect. In addition, AOX expression was able to partially alleviate the short lifespan of Drosophila models neuronally expressing human beta-amyloid peptides, whilst abrogating the induction of markers of oxidative stress. Our findings support the idea of respiratory chain dysfunction and excess ROS production as both an early step and as a pathologically meaningful target in Alzheimer's disease pathogenesis, supporting the concept of a mitochondrial vicious cycle underlying the disease.
Collapse
Affiliation(s)
- Riyad El-Khoury
- INSERM UMR 1141 and Université Paris 7, Faculté de Médecine Denis Diderot, Hôpital Robert Debré, 48, Boulevard Sérurier, 75019 Paris, France; American University of Beirut Medical Center, Department of Pathology and Laboratory Medicine, Cairo Street, Hamra, Beirut, Lebanon
| | - Eveliina Kaulio
- BioMediTech and Tampere University Hospital, FI-33014 University of Tampere, Finland
| | - Katariina A Lassila
- BioMediTech and Tampere University Hospital, FI-33014 University of Tampere, Finland
| | - Damian C Crowther
- Department of Genetics, University of Cambridge, Downing Street, Cambridge CB2 3EH, UK and MedImmune Ltd, Aaron Klug Building, Granta Park, Cambridge CB21 6GH, UK
| | - Howard T Jacobs
- BioMediTech and Tampere University Hospital, FI-33014 University of Tampere, Finland; Institute of Biotechnology, FI-00014 University of Helsinki, Finland.
| | - Pierre Rustin
- INSERM UMR 1141 and Université Paris 7, Faculté de Médecine Denis Diderot, Hôpital Robert Debré, 48, Boulevard Sérurier, 75019 Paris, France
| |
Collapse
|
77
|
Mitochondrial ROS Produced via Reverse Electron Transport Extend Animal Lifespan. Cell Metab 2016; 23:725-34. [PMID: 27076081 PMCID: PMC4835580 DOI: 10.1016/j.cmet.2016.03.009] [Citation(s) in RCA: 257] [Impact Index Per Article: 32.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Revised: 01/26/2016] [Accepted: 03/24/2016] [Indexed: 01/10/2023]
Abstract
Increased production of reactive oxygen species (ROS) has long been considered a cause of aging. However, recent studies have implicated ROS as essential secondary messengers. Here we show that the site of ROS production significantly contributes to their apparent dual nature. We report that ROS increase with age as mitochondrial function deteriorates. However, we also demonstrate that increasing ROS production specifically through respiratory complex I reverse electron transport extends Drosophila lifespan. Reverse electron transport rescued pathogenesis induced by severe oxidative stress, highlighting the importance of the site of ROS production in signaling. Furthermore, preventing ubiquinone reduction, through knockdown of PINK1, shortens lifespan and accelerates aging; phenotypes that are rescued by increasing reverse electron transport. These results illustrate that the source of a ROS signal is vital in determining its effects on cellular physiology and establish that manipulation of ubiquinone redox state is a valid strategy to delay aging.
Collapse
|
78
|
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.
Collapse
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
| |
Collapse
|
79
|
Rogov AG, Zvyagilskaya RA. Physiological role of alternative oxidase (from yeasts to plants). BIOCHEMISTRY (MOSCOW) 2016; 80:400-7. [PMID: 25869356 DOI: 10.1134/s0006297915040021] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Mitochondria of all so far studied organisms, with the exception of Archaea, mammals, some yeasts, and protists, contain, along with the classical phosphorylating cytochrome pathway, a so-called cyanide-insensitive alternative oxidase (AOX) localized on the matrix side of the mitochondrial inner membrane, and electron transport through which is not coupled with ATP synthesis and energy accumulation. Mechanisms underlying plentiful functions of AOX in organisms at various levels of organization ranging from yeasts to plants are considered. First and foremost, AOX provides a chance of cell survival after inhibiting the terminal components of the main respiratory chain or losing the ability to synthesize these components. The vitally important role of AOX is obvious in thermogenesis of thermogenic plant organs where it becomes the only terminal oxidase with a very high activity, and the energy of substrate oxidation by this respiratory pathway is converted into heat, thus promoting evaporation of volatile substances attracting pollinating insects. AOX plays a fundamentally significant role in alleviating or preventing oxidative stress, thus ensuring the defense against a wide range of stresses and adverse environmental conditions, such as changes in temperature and light intensities, osmotic stress, drought, and attack by incompatible strains of bacterial pathogens, phytopathogens, or their elicitors. Participation of AOX in pathogen survival during its existence inside the host, in antivirus defense, as well as in metabolic rearrangements in plants during embryogenesis and cell differentiation is described. Examples are given to demonstrate that AOX might be an important tool to overcome the adverse aftereffects of restricted activity of the main respiratory chain in cells and whole animals.
Collapse
Affiliation(s)
- A G Rogov
- Bach Institute of Biochemistry, Russian Academy of Sciences, Moscow, 119071, Russia.
| | | |
Collapse
|
80
|
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.
Collapse
|
81
|
Bénit P, Schiff M, Cwerman-Thibault H, Corral-Debrinski M, Rustin P. Drug development for mitochondrial disease: recent progress, current challenges, and future prospects. Expert Opin Orphan Drugs 2015. [DOI: 10.1517/21678707.2016.1117972] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
|
82
|
Rogov AG, Sukhanova EI, Uralskaya LA, Aliverdieva DA, Zvyagilskaya RA. Alternative oxidase: distribution, induction, properties, structure, regulation, and functions. BIOCHEMISTRY (MOSCOW) 2015; 79:1615-34. [PMID: 25749168 DOI: 10.1134/s0006297914130112] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The respiratory chain in the majority of organisms with aerobic type metabolism features the concomitant existence of the phosphorylating cytochrome pathway and the cyanide- and antimycin A-insensitive oxidative route comprising a so-called alternative oxidase (AOX) as a terminal oxidase. In this review, the history of AOX discovery is described. Considerable evidence is presented that AOX occurs widely in organisms at various levels of organization and is not confined to the plant kingdom. This enzyme has not been found only in Archaea, mammals, some yeasts and protists. Bioinformatics research revealed the sequences characteristic of AOX in representatives of various taxonomic groups. Based on multiple alignments of these sequences, a phylogenetic tree was constructed to infer their possible evolution. The ways of AOX activation, as well as regulatory interactions between AOX and the main respiratory chain are described. Data are summarized concerning the properties of AOX and the AOX-encoding genes whose expression is either constitutive or induced by various factors. Information is presented on the structure of AOX, its active center, and the ubiquinone-binding site. The principal functions of AOX are analyzed, including the cases of cell survival, optimization of respiratory metabolism, protection against excess of reactive oxygen species, and adaptation to variable nutrition sources and to biotic and abiotic stress factors. It is emphasized that different AOX functions complement each other in many instances and are not mutually exclusive. Examples are given to demonstrate that AOX is an important tool to overcome the adverse aftereffects of restricted activity of the main respiratory chain in cells and whole animals. This is the first comprehensive review on alternative oxidases of various organisms ranging from yeasts and protists to vascular plants.
Collapse
Affiliation(s)
- A G Rogov
- Bach Institute of Biochemistry, Russian Academy of Sciences, Moscow, 119071, Russia.
| | | | | | | | | |
Collapse
|
83
|
Syrjänen L, Valanne S, Kuuslahti M, Tuomela T, Sriram A, Sanz A, Jacobs HT, Rämet M, Parkkila S. β carbonic anhydrase is required for female fertility in Drosophila melanogaster. Front Zool 2015; 12:19. [PMID: 26300950 PMCID: PMC4546311 DOI: 10.1186/s12983-015-0111-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Accepted: 08/12/2015] [Indexed: 02/01/2023] Open
Abstract
Background Carbonic anhydrases (CAs, EC 4.2.1.1) are ubiquitous enzymes that catalyze the reversible hydration reaction of carbon dioxide. CAs are present as six structurally divergent enzyme families: α, β, γ, δ, ζ and η. β-CAs have a wide distribution across different species including invertebrates. Previously, we showed that Drosophila melanogaster β-CA is a highly active mitochondrial enzyme. In this study, we investigated the function of Drosophila β-CA by silencing the expression of the β-CA gene using UAS/GAL4-based RNA interference (RNAi) in Drosophila in vivo. Results Crossing β-CA RNAi lines over ubiquitous Actin driver flies did not produce any viable progeny, indicating that β-CA expression is required for fly development. RNAi silencing of β-CA ubiquitously in adult flies did not affect their survival rate or function of mitochondrial electron transport chain. Importantly, β-CA RNAi led to impaired reproduction. All β-CA knockdown females were sterile, and produced few or no eggs. Whole ovaries of knockdown females looked normal but upon cadherin staining, there was an apparent functional defect in migration of border cells, which are considered essential for normal fertilization. Conclusions These results indicate that although Drosophila β-CA is dispensable for survival of adult flies, it is essential for female fertility. Electronic supplementary material The online version of this article (doi:10.1186/s12983-015-0111-3) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Leo Syrjänen
- BioMediTech, University of Tampere, Tampere, Finland.,School of Medicine, University of Tampere and Tampere University Hospital, Tampere, Finland.,Department of Otorhinolaryngology, Central Finland Central Hospital, Jyväskylä, Finland
| | | | - Marianne Kuuslahti
- BioMediTech, University of Tampere, Tampere, Finland.,School of Medicine, University of Tampere and Tampere University Hospital, Tampere, Finland
| | - Tea Tuomela
- BioMediTech, University of Tampere, Tampere, Finland
| | - Ashwin Sriram
- BioMediTech, University of Tampere, Tampere, Finland.,Institute for Cell and Molecular Biosciences and Newcastle University Institute for Ageing Health, Newcastle University, Newcastle upon Tyne, UK
| | - Alberto Sanz
- BioMediTech, University of Tampere, Tampere, Finland.,Institute for Cell and Molecular Biosciences and Newcastle University Institute for Ageing Health, Newcastle University, Newcastle upon Tyne, UK
| | - Howard T Jacobs
- BioMediTech, University of Tampere, Tampere, Finland.,Institute of Biotechnology, University of Helsinki, Helsinki, Finland.,Tampere University Hospital, Tampere, Finland
| | - Mika Rämet
- BioMediTech, University of Tampere, Tampere, Finland.,Department of Pediatrics, Tampere University Hospital, Tampere, Finland.,PEDEGO Research Center, Medical Research Center Oulu, and Department of Children and Adolescents, Oulu University Hospital, Oulu, Finland
| | - Seppo Parkkila
- BioMediTech, University of Tampere, Tampere, Finland.,School of Medicine, University of Tampere and Tampere University Hospital, Tampere, Finland.,Fimlab Laboratories Ltd, Tampere, Finland
| |
Collapse
|
84
|
Lushchak OV, Carlsson MA, Nässel DR. Food odors trigger an endocrine response that affects food ingestion and metabolism. Cell Mol Life Sci 2015; 72:3143-55. [PMID: 25782410 PMCID: PMC11113394 DOI: 10.1007/s00018-015-1884-4] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2014] [Revised: 01/29/2015] [Accepted: 03/12/2015] [Indexed: 10/23/2022]
Abstract
Food odors stimulate appetite and innate food-seeking behavior in hungry animals. The smell of food also induces salivation and release of gastric acid and insulin. Conversely, sustained odor exposure may induce satiation. We demonstrate novel effects of food odors on food ingestion, metabolism and endocrine signaling in Drosophila melanogaster. Acute exposure to attractive vinegar odor triggers a rapid and transient increase in circulating glucose, and a rapid upregulation of genes encoding the glucagon-like hormone adipokinetic hormone (AKH), four insulin-like peptides (DILPs) and some target genes in peripheral tissues. Sustained exposure to food odors, however, decreases food intake. Hunger-induced strengthening of synaptic signaling from olfactory sensory neurons (OSNs) to brain neurons increases food-seeking behavior, and conversely fed flies display reduced food odor sensitivity and feeding. We show that increasing the strength of OSN signaling chronically by genetic manipulation of local peptide neuromodulation reduces feeding, elevates carbohydrates and diminishes lipids. Furthermore, constitutively strengthened odor sensitivity altered gene transcripts for AKH, DILPs and some of their targets. Thus, we show that food odor can induce a transient anticipatory endocrine response, and that boosted sensitivity to this odor affects food intake, as well as metabolism and hormonal signaling.
Collapse
Affiliation(s)
- Oleh V. Lushchak
- Department of Zoology, Stockholm University, 10691 Stockholm, Sweden
- Present Address: Department of Biochemistry and Biotechnology, Vasyl Stefanyk Precarpathian National University, Ivano-Frankivsk, Ukraine
| | | | - Dick R. Nässel
- Department of Zoology, Stockholm University, 10691 Stockholm, Sweden
| |
Collapse
|
85
|
Rovenko BM, Kubrak OI, Gospodaryov DV, Perkhulyn NV, Yurkevych IS, Sanz A, Lushchak OV, Lushchak VI. High sucrose consumption promotes obesity whereas its low consumption induces oxidative stress in Drosophila melanogaster. JOURNAL OF INSECT PHYSIOLOGY 2015; 79:42-54. [PMID: 26050918 DOI: 10.1016/j.jinsphys.2015.05.007] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Revised: 05/12/2015] [Accepted: 05/27/2015] [Indexed: 06/04/2023]
Abstract
The effects of sucrose in varied concentrations (0.25-20%) with constant amount of yeasts in larval diet on development and metabolic parameters of adult fruit fly Drosophila melanogaster were studied. Larvae consumed more food at low sucrose diet, overeating with yeast. On high sucrose diet, larvae ingested more carbohydrates, despite consuming less food and obtaining less protein derived from yeast. High sucrose diet slowed down pupation and increased pupa mortality, enhanced levels of lipids and glycogen, increased dry body mass, decreased water content, i.e. resulted in obese phenotype. Furthermore, it suppressed reactive oxygen species-induced oxidation of lipids and proteins as well as the activity of superoxide dismutase. The activity of catalase was gender-related. In males, at all sucrose concentrations used catalase activity was higher than at its concentration of 0.25%, whereas in females sucrose concentration virtually did not influence the activity. High sucrose diet increased content of protein thiols and the activity of glucose-6-phosphate dehydrogenase. The increase in sucrose concentration also enhanced uric acid level in females, but caused opposite effects in males. Development on high sucrose diets was accompanied by elevated steady-state insulin-like peptide 3 mRNA level. Finally, carbohydrate starvation at yeast overfeeding on low sucrose diets resulted in oxidative stress reflected by higher levels of oxidized lipids and proteins accompanied by increased superoxide dismutase activity. Potential mechanisms involved in regulation of redox processes by carbohydrates are discussed.
Collapse
Affiliation(s)
- Bohdana M Rovenko
- Department of Biochemistry and Biotechnology, Vassyl Stefanyk Precarpathian National University, Ivano-Frankivsk 76018, Ukraine
| | - Olga I Kubrak
- Department of Biochemistry and Biotechnology, Vassyl Stefanyk Precarpathian National University, Ivano-Frankivsk 76018, Ukraine
| | - Dmytro V Gospodaryov
- Department of Biochemistry and Biotechnology, Vassyl Stefanyk Precarpathian National University, Ivano-Frankivsk 76018, Ukraine
| | - Natalia V Perkhulyn
- Department of Biochemistry and Biotechnology, Vassyl Stefanyk Precarpathian National University, Ivano-Frankivsk 76018, Ukraine
| | - Ihor S Yurkevych
- Department of Biochemistry and Biotechnology, Vassyl Stefanyk Precarpathian National University, Ivano-Frankivsk 76018, Ukraine
| | - Alberto Sanz
- Institute for Cell and Molecular Biosciences and Newcastle Institute for Ageing, Newcastle University, Newcastle-Upon-Tyne NE4 5PL, UK
| | - Oleh V Lushchak
- Department of Biochemistry and Biotechnology, Vassyl Stefanyk Precarpathian National University, Ivano-Frankivsk 76018, Ukraine.
| | - Volodymyr I Lushchak
- Department of Biochemistry and Biotechnology, Vassyl Stefanyk Precarpathian National University, Ivano-Frankivsk 76018, Ukraine.
| |
Collapse
|
86
|
Senyilmaz D, Virtue S, Xu X, Tan CY, Griffin JL, Miller AK, Vidal-Puig A, Teleman AA. Regulation of mitochondrial morphology and function by stearoylation of TFR1. Nature 2015. [PMID: 26214738 PMCID: PMC4561519 DOI: 10.1038/nature14601] [Citation(s) in RCA: 151] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Mitochondria are involved in a variety of cellular functions including ATP production, amino acid and lipid biogenesis and breakdown, signaling and apoptosis1-3. Mitochondrial dysfunction has been linked to neurodegenerative diseases, cancer, and aging4. Although transcriptional mechanisms regulating mitochondrial abundance are known5, comparatively little is known about how mitochondrial function is regulated. We identify here the metabolite stearic acid (C18:0) and Transferrin Receptor (TfR1) as mitochondrial regulators. We elucidate a signaling pathway whereby C18:0 stearoylates TfR1, thereby inhibiting its activation of JNK signaling. This leads to reduced ubiquitination of mitofusin via HUWE1, thereby promoting mitochondrial fusion and function. We find that animal cells are poised to respond to both increases and decreases in C18:0 levels, with increased C18:0 dietary intake boosting mitochondrial fusion in vivo. Intriguingly, dietary C18:0 supplementation can counteract the mitochondrial dysfunction caused by genetic defects such as loss of the Parkinsons genes Pink or Parkin. This work identifies the metabolite C18:0 as a signaling molecule regulating mitochondrial function in response to diet.
Collapse
Affiliation(s)
- Deniz Senyilmaz
- German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
| | - Sam Virtue
- University of Cambridge Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Cambridge CB2 0QQ, UK
| | - Xiaojun Xu
- German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
| | - Chong Yew Tan
- University of Cambridge Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Cambridge CB2 0QQ, UK
| | - Julian L Griffin
- The Department of Biochemistry, Tennis Court Road, Cambridge CB2 1GA, UK
| | - Aubry K Miller
- German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
| | - Antonio Vidal-Puig
- University of Cambridge Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Cambridge CB2 0QQ, UK.,Wellcome Trust Sanger Institute, Hinxton, Cambridgeshire CB10 1SA, UK
| | | |
Collapse
|
87
|
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.
Collapse
|
88
|
Rovenko BM, Kubrak OI, Gospodaryov DV, Yurkevych IS, Sanz A, Lushchak OV, Lushchak VI. Restriction of glucose and fructose causes mild oxidative stress independently of mitochondrial activity and reactive oxygen species in Drosophila melanogaster. Comp Biochem Physiol A Mol Integr Physiol 2015; 187:27-39. [PMID: 25941153 DOI: 10.1016/j.cbpa.2015.04.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2015] [Revised: 04/17/2015] [Accepted: 04/23/2015] [Indexed: 01/25/2023]
Abstract
Our recent study showed different effects of glucose and fructose overconsumption on the development of obese phenotypes in Drosophila. Glucose induced glucose toxicity due to the increase in circulating glucose, whereas fructose was more prone to induce obesity promoting accumulation of reserve lipids and carbohydrates (Rovenko et al., Comp. Biochem. Physiol. A Mol. Integr. Physiol. 2015, 180, 75-85). Searching for mechanisms responsible for these phenotypes in this study, we analyzed mitochondrial activity, mitochondrial density, mtROS production, oxidative stress markers and antioxidant defense in fruit flies fed 0.25%, 4% and 10% glucose or fructose. It is shown that there is a complex interaction between dietary monosaccharide concentrations, mitochondrial activity and oxidative modifications to proteins and lipids. Glucose at high concentration (10%) reduced mitochondrial protein density and consequently respiration in flies, while fructose did not affect these parameters. The production of ROS by mitochondria did not reflect activities of mitochondrial complexes. Moreover, there was no clear connection between mtROS production and antioxidant defense or between antioxidant defense and developmental survival, shown in our previous study (Rovenko et al., Comp. Biochem. Physiol. A Mol. Integr. Physiol. 2015, 180, 75-85). Instead, mtROS and antioxidant machinery cooperated to maintain a redox state that determined survival rates, and paradoxically, pro-oxidant conditions facilitated larva survival independently of the type of carbohydrate. It seems that in this complex system glucose controls the amount of oxidative modification regulating mitochondrial activity, while fructose regulates steady-state mRNA levels of antioxidant enzymes.
Collapse
Affiliation(s)
- Bohdana M Rovenko
- Department of Biochemistry and Biotechnology, Vassyl Stefanyk Precarpathian National University, Ivano-Frankivsk 76018, Ukraine
| | - Olga I Kubrak
- Department of Biochemistry and Biotechnology, Vassyl Stefanyk Precarpathian National University, Ivano-Frankivsk 76018, Ukraine
| | - Dmytro V Gospodaryov
- Department of Biochemistry and Biotechnology, Vassyl Stefanyk Precarpathian National University, Ivano-Frankivsk 76018, Ukraine
| | - Ihor S Yurkevych
- Department of Biochemistry and Biotechnology, Vassyl Stefanyk Precarpathian National University, Ivano-Frankivsk 76018, Ukraine
| | - Alberto Sanz
- Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle-Upon-Tyne NE4 5PL, UK; Newcastle University Institute for Ageing, Newcastle University, Newcastle-Upon-Tyne NE4 5PL, UK
| | - Oleh V Lushchak
- Department of Biochemistry and Biotechnology, Vassyl Stefanyk Precarpathian National University, Ivano-Frankivsk 76018, Ukraine.
| | - Volodymyr I Lushchak
- Department of Biochemistry and Biotechnology, Vassyl Stefanyk Precarpathian National University, Ivano-Frankivsk 76018, Ukraine.
| |
Collapse
|
89
|
Viscomi C, Bottani E, Zeviani M. Emerging concepts in the therapy of mitochondrial disease. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2015; 1847:544-57. [PMID: 25766847 DOI: 10.1016/j.bbabio.2015.03.001] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2014] [Revised: 02/15/2015] [Accepted: 03/02/2015] [Indexed: 01/07/2023]
Abstract
Mitochondrial disorders are an important group of genetic conditions characterized by impaired oxidative phosphorylation. Mitochondrial disorders come with an impressive variability of symptoms, organ involvement, and clinical course, which considerably impact the quality of life and quite often shorten the lifespan expectancy. Although the last 20 years have witnessed an exponential increase in understanding the genetic and biochemical mechanisms leading to disease, this has not resulted in the development of effective therapeutic approaches, amenable of improving clinical course and outcome of these conditions to any significant extent. Therapeutic options for mitochondrial diseases still remain focused on supportive interventions aimed at relieving complications. However, new therapeutic strategies have recently been emerging, some of which have shown potential efficacy at the pre-clinical level. This review will present the state of the art on experimental therapy for mitochondrial disorders.
Collapse
Affiliation(s)
- Carlo Viscomi
- Unit of Molecular Neurogenetics, The Foundation "Carlo Besta" Institute of Neurology IRCCS, 20133 Milan, Italy; MRC-Mitochondrial Biology Unit, Cambridge CB2 0XY, UK.
| | | | - Massimo Zeviani
- Unit of Molecular Neurogenetics, The Foundation "Carlo Besta" Institute of Neurology IRCCS, 20133 Milan, Italy; MRC-Mitochondrial Biology Unit, Cambridge CB2 0XY, UK.
| |
Collapse
|
90
|
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.
Collapse
|
91
|
Peralta S, Torraco A, Iommarini L, Diaz F. Mitochondrial Diseases Part III: Therapeutic interventions in mouse models of OXPHOS deficiencies. Mitochondrion 2015; 23:71-80. [PMID: 25638392 DOI: 10.1016/j.mito.2015.01.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Accepted: 01/22/2015] [Indexed: 12/19/2022]
Abstract
Mitochondrial defects are the cause of numerous disorders affecting the oxidative phosphorylation system (OXPHOS) in humans leading predominantly to neurological and muscular degeneration. The molecular origin, manifestations, and progression of mitochondrial diseases have a broad spectrum, which makes very challenging to find a globally effective therapy. The study of the molecular mechanisms underlying the mitochondrial dysfunction indicates that there is a wide range of pathways, enzymes and molecules that can be potentially targeted for therapeutic purposes. Therefore, focusing on the pathology of the disease is essential to design new treatments. In this review, we will summarize and discuss the different therapeutic interventions tested in some mouse models of mitochondrial diseases emphasizing the molecular mechanisms of action and their potential applications.
Collapse
Affiliation(s)
- Susana Peralta
- Department of Neurology, University of Miami, Miller School of Medicine, Miami, FL 33136, USA.
| | - Alessandra Torraco
- Neuromuscular and Neurodegenerative Disorders, Laboratory of Molecular Medicine, Bambino Gesù Children's Hospital, IRCCS, Viale di San Paolo, 15 - 00146, Rome, Italy.
| | - Luisa Iommarini
- Department of Pharmacy and Biotechnology (FABIT), University of Bologna, Via Irnerio 42, 40126, Bologna, Italy.
| | - Francisca Diaz
- Department of Neurology, University of Miami, Miller School of Medicine, Miami, FL 33136, USA.
| |
Collapse
|
92
|
Chen Z, Qi Y, French S, Zhang G, Covian Garcia R, Balaban R, Xu H. Genetic mosaic analysis of a deleterious mitochondrial DNA mutation in Drosophila reveals novel aspects of mitochondrial regulation and function. Mol Biol Cell 2014; 26:674-84. [PMID: 25501370 PMCID: PMC4325838 DOI: 10.1091/mbc.e14-11-1513] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
A lethal mtDNA mutation affecting COX is fully rescued by AOX. The mutant genome level remains constant in the somatic tissues along the aging process in heteroplasmic flies. A genetic scheme creates tissue-specific heteroplasmy in otherwise heteroplasmic background and reveals that Ca2+ mishandling contributes to the neurodegeneration. Various human diseases are associated with mitochondrial DNA (mtDNA) mutations, but heteroplasmy—the coexistence of mutant and wild-type mtDNA—complicates their study. We previously isolated a temperature-lethal mtDNA mutation in Drosophila, mt:CoIT300I, which affects the cytochrome c oxidase subunit I (CoI) locus. In the present study, we found that the decrease in cytochrome c oxidase (COX) activity was ascribable to a temperature-dependent destabilization of cytochrome a heme. Consistently, the viability of homoplasmic flies at 29°C was fully restored by expressing an alternative oxidase, which specifically bypasses the cytochrome chains. Heteroplasmic flies are fully viable and were used to explore the age-related and tissue-specific phenotypes of mt:CoIT300I. The proportion of mt:CoIT300I genome remained constant in somatic tissues along the aging process, suggesting a lack of quality control mechanism to remove defective mitochondria containing a deleterious mtDNA mutation. Using a genetic scheme that expresses a mitochondrially targeted restriction enzyme to induce tissue-specific homoplasmy in heteroplasmic flies, we found that mt:CoIT300I homoplasmy in the eye caused severe neurodegeneration at 29°C. Degeneration was suppressed by improving mitochondrial Ca2+ uptake, suggesting that Ca2+ mishandling contributed to mt:CoIT300I pathogenesis. Our results demonstrate a novel approach for Drosophila mtDNA genetics and its application in modeling mtDNA diseases.
Collapse
Affiliation(s)
- Zhe Chen
- Laboratory of Molecular Genetics, National Institutes of Health, Bethesda, MD 20892
| | - Yun Qi
- Laboratory of Molecular Genetics, National Institutes of Health, Bethesda, MD 20892
| | - Stephanie French
- Laboratory of Cardiac Energetics, National Heart, Lung, and Blood Institute, Bethesda, MD 20892
| | - Guofeng Zhang
- National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD 20892
| | - Raúl Covian Garcia
- Laboratory of Cardiac Energetics, National Heart, Lung, and Blood Institute, Bethesda, MD 20892
| | - Robert Balaban
- Laboratory of Cardiac Energetics, National Heart, Lung, and Blood Institute, Bethesda, MD 20892
| | - Hong Xu
- Laboratory of Molecular Genetics, National Institutes of Health, Bethesda, MD 20892
| |
Collapse
|
93
|
El-Khoury R, Kemppainen KK, Dufour E, Szibor M, Jacobs HT, Rustin P. Engineering the alternative oxidase gene to better understand and counteract mitochondrial defects: state of the art and perspectives. Br J Pharmacol 2014; 171:2243-9. [PMID: 24383965 DOI: 10.1111/bph.12570] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2013] [Revised: 10/25/2013] [Accepted: 11/18/2013] [Indexed: 12/22/2022] Open
Abstract
Mitochondrial disorders are nowadays recognized as impinging on most areas of medicine. They include specific and widespread organ involvement, including both tissue degeneration and tumour formation. Despite the spectacular progresses made in the identification of their underlying molecular basis, effective therapy remains a distant goal. Our still rudimentary understanding of the pathophysiological mechanisms by which these diseases arise constitutes an obstacle to developing any rational treatments. In this context, the idea of using a heterologous gene, encoding a supplemental oxidase otherwise absent from mammals, potentially bypassing the defective portion of the respiratory chain, was proposed more than 10 years ago. The recent progress made in the expression of the alternative oxidase in a wide range of biological systems and disease conditions reveals great potential benefit, considering the broad impact of mitochondrial diseases. This review addresses the state of the art and the perspectives that can be now envisaged by using this strategy.
Collapse
Affiliation(s)
- Riyad El-Khoury
- INSERM UMR 1141, Paris, France; Université Paris 7, Paris, France
| | | | | | | | | | | |
Collapse
|
94
|
Dahan J, Tcherkez G, Macherel D, Benamar A, Belcram K, Quadrado M, Arnal N, Mireau H. Disruption of the CYTOCHROME C OXIDASE DEFICIENT1 gene leads to cytochrome c oxidase depletion and reorchestrated respiratory metabolism in Arabidopsis. PLANT PHYSIOLOGY 2014; 166:1788-802. [PMID: 25301889 PMCID: PMC4256860 DOI: 10.1104/pp.114.248526] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2014] [Accepted: 10/09/2014] [Indexed: 05/20/2023]
Abstract
Cytochrome c oxidase is the last respiratory complex of the electron transfer chain in mitochondria and is responsible for transferring electrons to oxygen, the final acceptor, in the classical respiratory pathway. The essentiality of this step makes it that depletion in complex IV leads to lethality, thereby impeding studies on complex IV assembly and respiration plasticity in plants. Here, we characterized Arabidopsis (Arabidopsis thaliana) embryo-lethal mutant lines impaired in the expression of the CYTOCHROME C OXIDASE DEFICIENT1 (COD1) gene, which encodes a mitochondria-localized PentatricoPeptide Repeat protein. Although unable to germinate under usual conditions, cod1 homozygous embryos could be rescued from immature seeds and developed in vitro into slow-growing bush-like plantlets devoid of a root system. cod1 mutants were defective in C-to-U editing events in cytochrome oxidase subunit2 and NADH dehydrogenase subunit4 transcripts, encoding subunits of respiratory complex IV and I, respectively, and consequently lacked cytochrome c oxidase activity. We further show that respiratory oxygen consumption by cod1 plantlets is exclusively associated with alternative oxidase activity and that alternative NADH dehydrogenases are also up-regulated in these plants. The metabolomics pattern of cod1 mutants was also deeply altered, suggesting that alternative metabolic pathways compensated for the probable resulting restriction in NADH oxidation. Being the first complex IV-deficient mutants described in higher plants, cod1 lines should be instrumental to future studies on respiration homeostasis.
Collapse
Affiliation(s)
- Jennifer Dahan
- AgroParisTech and Institut National de la Recherche Agronomique, Unité Mixte de Recherche 1318, Institut Jean-Pierre Bourgin, F-78000 Versailles, France (J.D., K.B., M.Q., N.A., H.M.);Institut de Biologie des Plantes, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 8618, and Plateforme Métabolisme-Métabolome, Institut Fédératif de Recherche 87, Université Paris-Sud, 91405 Orsay cedex, France (G.T.);Institut Universitaire de France, 75005 Paris, France (G.T.); andUniversité d'Angers, Unité Mixte de Recherche 1345, Institut de Recherche en Horticulture et Semences, Angers 49045, France (D.M., A.B.)
| | - Guillaume Tcherkez
- AgroParisTech and Institut National de la Recherche Agronomique, Unité Mixte de Recherche 1318, Institut Jean-Pierre Bourgin, F-78000 Versailles, France (J.D., K.B., M.Q., N.A., H.M.);Institut de Biologie des Plantes, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 8618, and Plateforme Métabolisme-Métabolome, Institut Fédératif de Recherche 87, Université Paris-Sud, 91405 Orsay cedex, France (G.T.);Institut Universitaire de France, 75005 Paris, France (G.T.); andUniversité d'Angers, Unité Mixte de Recherche 1345, Institut de Recherche en Horticulture et Semences, Angers 49045, France (D.M., A.B.)
| | - David Macherel
- AgroParisTech and Institut National de la Recherche Agronomique, Unité Mixte de Recherche 1318, Institut Jean-Pierre Bourgin, F-78000 Versailles, France (J.D., K.B., M.Q., N.A., H.M.);Institut de Biologie des Plantes, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 8618, and Plateforme Métabolisme-Métabolome, Institut Fédératif de Recherche 87, Université Paris-Sud, 91405 Orsay cedex, France (G.T.);Institut Universitaire de France, 75005 Paris, France (G.T.); andUniversité d'Angers, Unité Mixte de Recherche 1345, Institut de Recherche en Horticulture et Semences, Angers 49045, France (D.M., A.B.)
| | - Abdelilah Benamar
- AgroParisTech and Institut National de la Recherche Agronomique, Unité Mixte de Recherche 1318, Institut Jean-Pierre Bourgin, F-78000 Versailles, France (J.D., K.B., M.Q., N.A., H.M.);Institut de Biologie des Plantes, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 8618, and Plateforme Métabolisme-Métabolome, Institut Fédératif de Recherche 87, Université Paris-Sud, 91405 Orsay cedex, France (G.T.);Institut Universitaire de France, 75005 Paris, France (G.T.); andUniversité d'Angers, Unité Mixte de Recherche 1345, Institut de Recherche en Horticulture et Semences, Angers 49045, France (D.M., A.B.)
| | - Katia Belcram
- AgroParisTech and Institut National de la Recherche Agronomique, Unité Mixte de Recherche 1318, Institut Jean-Pierre Bourgin, F-78000 Versailles, France (J.D., K.B., M.Q., N.A., H.M.);Institut de Biologie des Plantes, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 8618, and Plateforme Métabolisme-Métabolome, Institut Fédératif de Recherche 87, Université Paris-Sud, 91405 Orsay cedex, France (G.T.);Institut Universitaire de France, 75005 Paris, France (G.T.); andUniversité d'Angers, Unité Mixte de Recherche 1345, Institut de Recherche en Horticulture et Semences, Angers 49045, France (D.M., A.B.)
| | - Martine Quadrado
- AgroParisTech and Institut National de la Recherche Agronomique, Unité Mixte de Recherche 1318, Institut Jean-Pierre Bourgin, F-78000 Versailles, France (J.D., K.B., M.Q., N.A., H.M.);Institut de Biologie des Plantes, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 8618, and Plateforme Métabolisme-Métabolome, Institut Fédératif de Recherche 87, Université Paris-Sud, 91405 Orsay cedex, France (G.T.);Institut Universitaire de France, 75005 Paris, France (G.T.); andUniversité d'Angers, Unité Mixte de Recherche 1345, Institut de Recherche en Horticulture et Semences, Angers 49045, France (D.M., A.B.)
| | - Nadège Arnal
- AgroParisTech and Institut National de la Recherche Agronomique, Unité Mixte de Recherche 1318, Institut Jean-Pierre Bourgin, F-78000 Versailles, France (J.D., K.B., M.Q., N.A., H.M.);Institut de Biologie des Plantes, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 8618, and Plateforme Métabolisme-Métabolome, Institut Fédératif de Recherche 87, Université Paris-Sud, 91405 Orsay cedex, France (G.T.);Institut Universitaire de France, 75005 Paris, France (G.T.); andUniversité d'Angers, Unité Mixte de Recherche 1345, Institut de Recherche en Horticulture et Semences, Angers 49045, France (D.M., A.B.)
| | - Hakim Mireau
- AgroParisTech and Institut National de la Recherche Agronomique, Unité Mixte de Recherche 1318, Institut Jean-Pierre Bourgin, F-78000 Versailles, France (J.D., K.B., M.Q., N.A., H.M.);Institut de Biologie des Plantes, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 8618, and Plateforme Métabolisme-Métabolome, Institut Fédératif de Recherche 87, Université Paris-Sud, 91405 Orsay cedex, France (G.T.);Institut Universitaire de France, 75005 Paris, France (G.T.); andUniversité d'Angers, Unité Mixte de Recherche 1345, Institut de Recherche en Horticulture et Semences, Angers 49045, France (D.M., A.B.)
| |
Collapse
|
95
|
Gospodaryov DV, Lushchak OV, Rovenko BM, Perkhulyn NV, Gerards M, Tuomela T, Jacobs HT. Ciona intestinalis NADH dehydrogenase NDX confers stress-resistance and extended lifespan on Drosophila. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2014; 1837:1861-1869. [DOI: 10.1016/j.bbabio.2014.08.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2014] [Revised: 08/04/2014] [Accepted: 08/05/2014] [Indexed: 11/16/2022]
|
96
|
Da-Rè C, von Stockum S, Biscontin A, Millino C, Cisotto P, Zordan MA, Zeviani M, Bernardi P, De Pittà C, Costa R. Leigh syndrome in Drosophila melanogaster: morphological and biochemical characterization of Surf1 post-transcriptional silencing. J Biol Chem 2014; 289:29235-46. [PMID: 25164807 PMCID: PMC4200275 DOI: 10.1074/jbc.m114.602938] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Revised: 08/26/2014] [Indexed: 01/20/2023] Open
Abstract
Leigh Syndrome (LS) is the most common early-onset, progressive mitochondrial encephalopathy usually leading to early death. The single most prevalent cause of LS is occurrence of mutations in the SURF1 gene, and LS(Surf1) patients show a ubiquitous and specific decrease in the activity of mitochondrial respiratory chain complex IV (cytochrome c oxidase, COX). SURF1 encodes an inner membrane mitochondrial protein involved in COX assembly. We established a Drosophila melanogaster model of LS based on the post-transcriptional silencing of CG9943, the Drosophila homolog of SURF1. Knockdown of Surf1 was induced ubiquitously in larvae and adults, which led to lethality; in the mesodermal derivatives, which led to pupal lethality; or in the central nervous system, which allowed survival. A biochemical characterization was carried out in knockdown individuals, which revealed that larvae unexpectedly displayed defects in all complexes of the mitochondrial respiratory chain and in the F-ATP synthase, while adults had a COX-selective impairment. Silencing of Surf1 expression in Drosophila S2R(+) cells led to selective loss of COX activity associated with decreased oxygen consumption and respiratory reserve. We conclude that Surf1 is essential for COX activity and mitochondrial function in D. melanogaster, thus providing a new tool that may help clarify the pathogenic mechanisms of LS.
Collapse
Affiliation(s)
| | | | | | - Caterina Millino
- CRIBI Biotechnology Centre, University of Padova, 35121 Padova, Italy and
| | | | | | - Massimo Zeviani
- MRC Mitochondrial Biology Unit, University of Cambridge, Cambridge CB2 0XY, United Kingdom
| | | | | | | |
Collapse
|
97
|
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.
Collapse
|
98
|
Fernández-Ayala DJM, Jiménez-Gancedo S, Guerra I, Navas P. Invertebrate models for coenzyme q10 deficiency. Mol Syndromol 2014; 5:170-9. [PMID: 25126050 DOI: 10.1159/000362751] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
The human syndrome of coenzyme Q (CoQ) deficiency is a heterogeneous mitochondrial disease characterized by a diminution of CoQ content in cells and tissues that affects all the electron transport processes CoQ is responsible for, like the electron transference in mitochondria for respiration and ATP production and the antioxidant capacity that it exerts in membranes and lipoproteins. Supplementation with external CoQ is the main attempt to address these pathologies, but quite variable results have been obtained ranging from little response to a dramatic recovery. Here, we present the importance of modeling human CoQ deficiencies in animal models to understand the genetics and the pathology of this disease, although the election of an organism is crucial and can sometimes be controversial. Bacteria and yeast harboring mutations that lead to CoQ deficiency are unable to grow if they have to respire but develop without any problems on media with fermentable carbon sources. The complete lack of CoQ in mammals causes embryonic lethality, whereas other mutations produce tissue-specific diseases as in humans. However, working with transgenic mammals is time and cost intensive, with no assurance of obtaining results. Caenorhabditis elegans and Drosophila melanogaster have been used for years as organisms to study embryonic development, biogenesis, degenerative pathologies, and aging because of the genetic facilities and the speed of working with these animal models. In this review, we summarize several attempts to model reliable human CoQ deficiencies in invertebrates, focusing on mutant phenotypes pretty similar to those observed in human patients.
Collapse
Affiliation(s)
- Daniel J M Fernández-Ayala
- Centro Andaluz de Biología del Desarrollo, Universidad Pablo Olavide - CSIC, and CIBERER Instituto de Salud Carlos III, Seville, Spain
| | - Sandra Jiménez-Gancedo
- Centro Andaluz de Biología del Desarrollo, Universidad Pablo Olavide - CSIC, and CIBERER Instituto de Salud Carlos III, Seville, Spain
| | - Ignacio Guerra
- Centro Andaluz de Biología del Desarrollo, Universidad Pablo Olavide - CSIC, and CIBERER Instituto de Salud Carlos III, Seville, Spain
| | - Plácido Navas
- Centro Andaluz de Biología del Desarrollo, Universidad Pablo Olavide - CSIC, and CIBERER Instituto de Salud Carlos III, Seville, Spain
| |
Collapse
|
99
|
Fukuoh A, Cannino G, Gerards M, Buckley S, Kazancioglu S, Scialo F, Lihavainen E, Ribeiro A, Dufour E, Jacobs HT. Screen for mitochondrial DNA copy number maintenance genes reveals essential role for ATP synthase. Mol Syst Biol 2014; 10:734. [PMID: 24952591 PMCID: PMC4265055 DOI: 10.15252/msb.20145117] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The machinery of mitochondrial DNA (mtDNA) maintenance is only partially characterized and is of wide interest due to its involvement in disease. To identify novel components of this machinery, plus other cellular pathways required for mtDNA viability, we implemented a genome-wide RNAi screen in Drosophila S2 cells, assaying for loss of fluorescence of mtDNA nucleoids stained with the DNA-intercalating agent PicoGreen. In addition to previously characterized components of the mtDNA replication and transcription machineries, positives included many proteins of the cytosolic proteasome and ribosome (but not the mitoribosome), three proteins involved in vesicle transport, some other factors involved in mitochondrial biogenesis or nuclear gene expression, > 30 mainly uncharacterized proteins and most subunits of ATP synthase (but no other OXPHOS complex). ATP synthase knockdown precipitated a burst of mitochondrial ROS production, followed by copy number depletion involving increased mitochondrial turnover, not dependent on the canonical autophagy machinery. Our findings will inform future studies of the apparatus and regulation of mtDNA maintenance, and the role of mitochondrial bioenergetics and signaling in modulating mtDNA copy number.
Collapse
Affiliation(s)
- Atsushi Fukuoh
- BioMediTech and Tampere University Hospital, University of Tampere, Tampere, Finland Department of Clinical Chemistry and Laboratory Medicine, Kyushu University Graduate school of Medical Sciences, Fukuoka, Japan Department of Medical Laboratory Science, Junshin Gakuen University, Fukuoka, Japan
| | - Giuseppe Cannino
- BioMediTech and Tampere University Hospital, University of Tampere, Tampere, Finland
| | - Mike Gerards
- BioMediTech and Tampere University Hospital, University of Tampere, Tampere, Finland
| | - Suzanne Buckley
- BioMediTech and Tampere University Hospital, University of Tampere, Tampere, Finland
| | - Selena Kazancioglu
- BioMediTech and Tampere University Hospital, University of Tampere, Tampere, Finland
| | - Filippo Scialo
- BioMediTech and Tampere University Hospital, University of Tampere, Tampere, Finland
| | - Eero Lihavainen
- Department of Signal Processing, Tampere University of Technology, Tampere, Finland
| | - Andre Ribeiro
- Department of Signal Processing, Tampere University of Technology, Tampere, Finland
| | - Eric Dufour
- BioMediTech and Tampere University Hospital, University of Tampere, Tampere, Finland
| | - Howard T Jacobs
- BioMediTech and Tampere University Hospital, University of Tampere, Tampere, Finland Research Program of Molecular Neurology, University of Helsinki, Helsinki, Finland
| |
Collapse
|
100
|
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.
Collapse
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.
| |
Collapse
|