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Jacobs HT, George J, Kemppainen E. Regulation of growth in Drosophila melanogaster: the roles of mitochondrial metabolism. J Biochem 2020; 167:267-277. [PMID: 31926002 PMCID: PMC7048069 DOI: 10.1093/jb/mvaa002] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2019] [Accepted: 01/05/2020] [Indexed: 12/14/2022] Open
Abstract
Mitochondrial functions are often considered purely from the standpoint of catabolism, but in growing cells they are mainly dedicated to anabolic processes, and can have a profound impact on the rate of growth. The Drosophila larva, which increases in body mass ∼200-fold over the course of ∼3 days at 25°C, provides an excellent model to study the underlying regulatory machinery that connects mitochondrial metabolic capacity to growth. In this review, we will focus on several key aspects of this machinery: nutrient sensing, endocrine control of feeding and nutrient mobilization, metabolic signalling, protein synthesis regulation and pathways of steroid biosynthesis and activity. In all these aspects, mitochondria appear to play a crucial role.
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Affiliation(s)
- Howard T Jacobs
- Faculty of Medicine and Health Technology, FI-33014 Tampere University, Finland
| | - Jack George
- Faculty of Medicine and Health Technology, FI-33014 Tampere University, Finland
| | - Esko Kemppainen
- Faculty of Medicine and Health Technology, FI-33014 Tampere University, Finland
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2
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Salminen TS, Vale PF. Drosophila as a Model System to Investigate the Effects of Mitochondrial Variation on Innate Immunity. Front Immunol 2020; 11:521. [PMID: 32269576 PMCID: PMC7109263 DOI: 10.3389/fimmu.2020.00521] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 03/06/2020] [Indexed: 12/14/2022] Open
Abstract
Understanding why the response to infection varies between individuals remains one of the major challenges in immunology and infection biology. A substantial proportion of this heterogeneity can be explained by individual genetic differences which result in variable immune responses, and there are many examples of polymorphisms in nuclear-encoded genes that alter immunocompetence. However, how immunity is affected by genetic polymorphism in an additional genome, inherited maternally inside mitochondria (mtDNA), has been relatively understudied. Mitochondria are increasingly recognized as important mediators of innate immune responses, not only because they are the main source of energy required for costly immune responses, but also because by-products of mitochondrial metabolism, such as reactive oxygen species (ROS), may have direct microbicidal action. Yet, it is currently unclear how naturally occurring variation in mtDNA contributes to heterogeneity in infection outcomes. In this review article, we describe potential sources of variation in mitochondrial function that may arise due to mutations in vital nuclear and mitochondrial components of energy production or due to a disruption in mito-nuclear crosstalk. We then highlight how these changes in mitochondrial function can impact immune responses, focusing on their effects on ATP- and ROS-generating pathways, as well as immune signaling. Finally, we outline how being a powerful and genetically tractable model of infection, immunity and mitochondrial genetics makes the fruit fly Drosophila melanogaster ideally suited to dissect mitochondrial effects on innate immune responses to infection.
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Affiliation(s)
- Tiina S. Salminen
- School of Biological Sciences, Institute of Evolutionary Biology, The University of Edinburgh, Edinburgh, United Kingdom
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - Pedro F. Vale
- School of Biological Sciences, Institute of Evolutionary Biology, The University of Edinburgh, Edinburgh, United Kingdom
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3
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Morten KJ, Potter M, Badder L, Sivathondan P, Dragovic R, Neumann A, Gavin J, Shrestha R, Reilly S, Phadwal K, Lodge TA, Borzychowski A, Cookson S, Mitchell C, Morovat A, Simon AK, Uusimaa J, Hynes J, Poulton J. Insights into pancreatic β cell energy metabolism using rodent β cell models. Wellcome Open Res 2019; 2:14. [PMID: 31754635 PMCID: PMC6854877 DOI: 10.12688/wellcomeopenres.10535.3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/16/2019] [Indexed: 01/07/2023] Open
Abstract
Background: Mitochondrial diabetes is primarily caused by β-cell failure, a cell type whose unique properties are important in pathogenesis. Methods: By reducing glucose, we induced energetic stress in two rodent β-cell models to assess effects on cellular function. Results: Culturing rat insulin-secreting INS-1 cells in low glucose conditions caused a rapid reduction in whole cell respiration, associated with elevated mitochondrial reactive oxygen species production, and an altered glucose-stimulated insulin secretion profile. Prolonged exposure to reduced glucose directly impaired mitochondrial function and reduced autophagy. Conclusions: Insulinoma cell lines have a very different bioenergetic profile to many other cell lines and provide a useful model of mechanisms affecting β-cell mitochondrial function.
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Affiliation(s)
- Karl J Morten
- Nuffield Department of Obstetrics & Gynaecology, The Women's Centre, University of Oxford, John Radcliffe Hospital, Oxford, UK
| | - Michelle Potter
- Nuffield Department of Obstetrics & Gynaecology, The Women's Centre, University of Oxford, John Radcliffe Hospital, Oxford, UK
| | - Luned Badder
- Nuffield Department of Obstetrics & Gynaecology, The Women's Centre, University of Oxford, John Radcliffe Hospital, Oxford, UK
| | - Pamela Sivathondan
- Nuffield Department of Obstetrics & Gynaecology, The Women's Centre, University of Oxford, John Radcliffe Hospital, Oxford, UK
| | - Rebecca Dragovic
- Nuffield Department of Obstetrics & Gynaecology, The Women's Centre, University of Oxford, John Radcliffe Hospital, Oxford, UK
| | - Abigale Neumann
- Nuffield Department of Obstetrics & Gynaecology, The Women's Centre, University of Oxford, John Radcliffe Hospital, Oxford, UK
| | - James Gavin
- Nuffield Department of Obstetrics & Gynaecology, The Women's Centre, University of Oxford, John Radcliffe Hospital, Oxford, UK
| | - Roshan Shrestha
- Nuffield Department of Obstetrics & Gynaecology, The Women's Centre, University of Oxford, John Radcliffe Hospital, Oxford, UK
| | - Svetlana Reilly
- Department of Cardiovascular Medicine, John Radcliffe Hospital, Oxford, UK
| | - Kanchan Phadwal
- BRC Translational Immunology Lab, NIHR, Nuffield Department of Medicine, University of Oxford, John Radcliffe Hospital, Oxford, UK
| | - Tiffany A Lodge
- Nuffield Department of Obstetrics & Gynaecology, The Women's Centre, University of Oxford, John Radcliffe Hospital, Oxford, UK
| | - Angela Borzychowski
- Nuffield Department of Obstetrics & Gynaecology, The Women's Centre, University of Oxford, John Radcliffe Hospital, Oxford, UK
| | - Sharon Cookson
- Institute of Cellular Medicine, Haematological Sciences, Medical School, Newcastle University, Newcastle upon Tyne, UK
| | - Corey Mitchell
- Nuffield Department of Obstetrics & Gynaecology, The Women's Centre, University of Oxford, John Radcliffe Hospital, Oxford, UK
| | | | | | - Johanna Uusimaa
- Department of Paediatrics, University of Oulu, Oulu, Finland
| | - James Hynes
- Luxcel BioSciences Ltd, BioInnovation Centre, University College Cork, Cork, Ireland
| | - Joanna Poulton
- Nuffield Department of Obstetrics & Gynaecology, The Women's Centre, University of Oxford, John Radcliffe Hospital, Oxford, UK
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4
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George J, Tuomela T, Kemppainen E, Nurminen A, Braun S, Yalgin C, Jacobs HT. Mitochondrial dysfunction generates a growth-restraining signal linked to pyruvate in Drosophila larvae. Fly (Austin) 2019; 13:12-28. [PMID: 31526131 PMCID: PMC6988875 DOI: 10.1080/19336934.2019.1662266] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The Drosophila bang-sensitive mutant tko25t, manifesting a global deficiency in oxidative phosphorylation due to a mitochondrial protein synthesis defect, exhibits a pronounced delay in larval development. We previously identified a number of metabolic abnormalities in tko25t larvae, including elevated pyruvate and lactate, and found the larval gut to be a crucial tissue for the regulation of larval growth in the mutant. Here we established that expression of wild-type tko in any of several other tissues of tko25t also partially alleviates developmental delay. The effects appeared to be additive, whilst knockdown of tko in a variety of specific tissues phenocopied tko25t, producing developmental delay and bang-sensitivity. These findings imply the existence of a systemic signal regulating growth in response to mitochondrial dysfunction. Drugs and RNAi-targeted on pyruvate metabolism interacted with tko25t in ways that implicated pyruvate or one of its metabolic derivatives in playing a central role in generating such a signal. RNA-seq revealed that dietary pyruvate-induced changes in transcript representation were mostly non-coherent with those produced by tko25t or high-sugar, consistent with the idea that growth regulation operates primarily at the translational and/or metabolic level.
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Affiliation(s)
- Jack George
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - Tea Tuomela
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - Esko Kemppainen
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - Antti Nurminen
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - Samuel Braun
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - Cagri Yalgin
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland.,Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Howard T Jacobs
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland.,Institute of Biotechnology, University of Helsinki, Helsinki, Finland
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5
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George J, Jacobs HT. Minimal effects of spargel (PGC-1) overexpression in a Drosophila mitochondrial disease model. Biol Open 2019; 8:bio.042135. [PMID: 31292108 PMCID: PMC6679408 DOI: 10.1242/bio.042135] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
PGC-1α and its homologues have been proposed to act as master regulators of mitochondrial biogenesis in animals. Most relevant studies have been conducted in mammals, where interpretation is complicated by the fact that there are three partially redundant members of the gene family. In Drosophila, only a single PGC-1 homologue, spargel (srl), is present in the genome. Here, we analyzed the effects of srl overexpression on phenotype and on gene expression in tko25t, a recessive bang-sensitive mutant with a global defect in oxidative phosphorylation, resulting from a deficiency of mitochondrial protein synthesis. In contrast to previous reports, we found that substantial overexpression of srl throughout development had only minimal effects on the tko25t mutant phenotype. Copy number of mtDNA was unaltered and srl overexpression produced no systematic effects on a representative set of transcripts related to mitochondrial OXPHOS and other metabolic enzymes, although these were influenced by sex and genetic background. This study provides no support to the concept of Spargel as a global regulator of mitochondrial biogenesis, at least in the context of the tko25t model. Summary: Overexpression of spargel, the fly PGC-1 homologue proposed as a mitochondrial biogenesis regulator, has minimal effects on the phenotype of tko25t, considered a fly model for mitochondrial disease.
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Affiliation(s)
- Jack George
- Faculty of Medicine and Health Technology, FI-33014 Tampere University, Finland
| | - Howard T Jacobs
- Faculty of Medicine and Health Technology, FI-33014 Tampere University, Finland
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6
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Lethal Interaction of Nuclear and Mitochondrial Genotypes in Drosophila melanogaster. G3-GENES GENOMES GENETICS 2019; 9:2225-2234. [PMID: 31076384 PMCID: PMC6643882 DOI: 10.1534/g3.119.400315] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Drosophilamelanogaster, like most animal species, displays considerable genetic variation in both nuclear and mitochondrial DNA (mtDNA). Here we tested whether any of four natural mtDNA variants was able to modify the effect of the phenotypically mild, nuclear tko25t mutation, affecting mitochondrial protein synthesis. When combined with tko25t, the mtDNA from wild strain KSA2 produced pupal lethality, accompanied by the presence of melanotic nodules in L3 larvae. KSA2 mtDNA, which carries a substitution at a conserved residue of cytochrome b that is predicted to be involved in subunit interactions within respiratory complex III, conferred drastically decreased respiratory capacity and complex III activity in the tko25t but not a wild-type nuclear background. The complex III inhibitor antimycin A was able to phenocopy effects of the tko25t mutation in the KSA2 mtDNA background. This is the first report of a lethal, nuclear-mitochondrial interaction within a metazoan species, representing a paradigm for understanding genetic interactions between nuclear and mitochondrial genotype relevant to human health and disease.
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7
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Saari S, Kemppainen E, Tuomela T, Oliveira MT, Dufour E, Jacobs HT. Alternative oxidase confers nutritional limitation on Drosophila development. JOURNAL OF EXPERIMENTAL ZOOLOGY PART 2019; 331:341-356. [PMID: 31218852 PMCID: PMC6617715 DOI: 10.1002/jez.2274] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/23/2018] [Revised: 04/12/2019] [Accepted: 05/17/2019] [Indexed: 11/12/2022]
Abstract
The mitochondrial alternative oxidase, AOX, present in most eukaryotes apart from vertebrates and insects, catalyzes the direct oxidation of ubiquinol by oxygen, by‐passing the terminal proton‐motive steps of the respiratory chain. Its physiological role is not fully understood, but it is proposed to buffer stresses in the respiratory chain similar to those encountered in mitochondrial diseases in humans. Previously, we found that the ubiquitous expression of AOX from Ciona intestinalis in
Drosophila perturbs the development of flies cultured under low‐nutrient conditions (media containing only glucose and yeast). Here we tested the effects of a wide range of nutritional supplements on
Drosophila development, to gain insight into the physiological mechanism underlying this developmental failure. On low‐nutrient medium, larvae contained decreased amounts of triglycerides, lactate, and pyruvate, irrespective of AOX expression. Complex food supplements, including treacle (molasses), restored normal development to AOX‐expressing flies, but many individual additives did not. Inhibition of AOX by treacle extract was excluded as a mechanism, since the supplement did not alter the enzymatic activity of AOX in vitro. Furthermore, antibiotics did not influence the organismal phenotype, indicating that commensal microbes were not involved. Fractionation of treacle identified a water‐soluble fraction with low solubility in ethanol, rich in lactate and tricarboxylic acid cycle intermediates, which contained the critical activity. We propose that the partial activation of AOX during metamorphosis impairs the efficient use of stored metabolites, resulting in developmental failure. Drosophila expressing the alternative oxidase are unable to complete pupal development if reared on low‐nutrient medium. Additional nutrients are needed, to replace those normally manufactured cataplerotically.
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Affiliation(s)
- Sina Saari
- Faculty of Medicine and Health Technology and Tampere University Hospital, Tampere University, Tampere, Finland
| | - Esko Kemppainen
- Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, Turku, Finland
| | - Tea Tuomela
- Faculty of Medicine and Health Technology and Tampere University Hospital, Tampere University, Tampere, Finland
| | - Marcos T Oliveira
- Departamento de Tecnologia, Faculdade de Ciências Agrárias e Veterinárias, Universidade Estadual Paulista "Júlio de Mesquita Filho", Jaboticabal, SP, Brazil
| | - Eric Dufour
- Faculty of Medicine and Health Technology and Tampere University Hospital, Tampere University, Tampere, Finland
| | - Howard T Jacobs
- Faculty of Medicine and Health Technology and Tampere University Hospital, Tampere University, Tampere, Finland.,Institute of Biotechnology, University of Helsinki, Helsinki, Finland
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8
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The effects of rooibos (Aspalathus linearis) on 3T3-L1 preadipocytes after the induction of mitochondrial dysfunction. J Funct Foods 2019. [DOI: 10.1016/j.jff.2019.02.017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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9
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Reynolds ER. Shortened Lifespan and Other Age-Related Defects in Bang Sensitive Mutants of Drosophila melanogaster. G3 (BETHESDA, MD.) 2018; 8:3953-3960. [PMID: 30355763 PMCID: PMC6288826 DOI: 10.1534/g3.118.200610] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Accepted: 10/18/2018] [Indexed: 11/28/2022]
Abstract
Mitochondrial diseases are complex disorders that exhibit their primary effects in energetically active tissues. Damage generated by mitochondria is also thought to be a key component of aging and age-related disease. An important model for mitochondrial dysfunction is the bang sensitive (bs) mutants in Drosophila melanogaster Although these mutants all show a striking seizure phenotype, several bs mutants have gene products that are involved with mitochondrial function, while others affect excitability another way. All of the bs mutants (parabss , eas, jus, ses B, tko are examined here) paralyze and seize upon challenge with a sensory stimulus, most notably mechanical stimulation. These and other excitability mutants have been linked to neurodegeneration with age. In addition to these phenotypes, we have found age-related defects for several of the bs strains. The mutants eas, ses B, and tko display shortened lifespan, an increased mean recovery time from seizure with age, and decreased climbing ability over lifespan as compared to isogenic CS or w1118 lines. Other mutants show a subset of these defects. The age-related phenotypes can be rescued by feeding melatonin, an antioxidant, in all the mutants except ses B The age-related defects do not appear to be correlated with the seizure phenotype. Inducing seizures on a daily basis did not exacerbate the phenotypes and treatment with antiepileptic drugs did not increase lifespan. The results suggest that the excitability phenotypes and the age-related phenotypes may be somewhat independent and that these phenotypes mutants may arise from impacts on different pathways.
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10
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Melvin RG, Lamichane N, Havula E, Kokki K, Soeder C, Jones CD, Hietakangas V. Natural variation in sugar tolerance associates with changes in signaling and mitochondrial ribosome biogenesis. eLife 2018; 7:40841. [PMID: 30480548 PMCID: PMC6301794 DOI: 10.7554/elife.40841] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Accepted: 11/27/2018] [Indexed: 12/21/2022] Open
Abstract
How dietary selection affects genome evolution to define the optimal range of nutrient intake is a poorly understood question with medical relevance. We have addressed this question by analyzing Drosophila simulans and sechellia, recently diverged species with differential diet choice. D. sechellia larvae, specialized to a nutrient scarce diet, did not survive on sugar-rich conditions, while the generalist species D. simulans was sugar tolerant. Sugar tolerance in D. simulans was a tradeoff for performance on low-energy diet and was associated with global reprogramming of metabolic gene expression. Hybridization and phenotype-based introgression revealed the genomic regions of D. simulans that were sufficient for sugar tolerance. These regions included genes that are involved in mitochondrial ribosome biogenesis and intracellular signaling, such as PPP1R15/Gadd34 and SERCA, which contributed to sugar tolerance. In conclusion, genomic variation affecting genes involved in global metabolic control defines the optimal range for dietary macronutrient composition. Animals meet their nutritional needs in a variety of ways. Some animals are specialists feeding only on one type of food; others are generalists that can choose many different kinds of food depending on the situation. Despite these differences in diet, animals have similar needs for basic cellular metabolism. This suggests that generalist and specialist species likely process the foods they eat in different ways in order to meet their basic needs. For example, the metabolism of generalist species may be more flexible to adapt to changing food sources. To learn more about how metabolism evolves to respond to diet, scientists can study closely related species that eat different foods. For example, a species of fruit fly called Drosophila simulans is a generalist and its larvae can grow and develop by feeding on different kinds of decaying fruits and vegetables. Larvae of a closely related fruit fly called Drosophila sechellia are specialized to eat only the nutrient-poor Morinda fruit. Looking at how genetic differences between these species affect metabolism may provide scientists with clues about how these feeding strategies evolved. Melvin et al. grew larvae of D. sechellia and D. simulans in different conditions. D. sechellia larvae thrived in low nutrient conditions, but died when exposed to high sugar foods. By contrast, D. simulans larvae tolerated high sugar levels, but did poorly in low-nutrient conditions. Melvin et al. then bred the two species with each other, selecting flies that are genetically similar to D. sechellia but have the genes necessary for larvae to tolerate sugar. Analyzing the selected hybrid flies revealed genetic changes that explain the different survival abilities of each species. These changes suggest that D. sechellia rapidly evolved to thrive in low nutrient conditions, but the trade-off was losing their ability to tolerate high sugar levels. Overall, the results presented by Melvin et al. suggest that genetic adaptions to food sources can occur quickly and drastically change metabolism. Further research will be needed to confirm if similar metabolic trade-offs developed as part of human evolution. If so, human populations that survived with limited nutrition for many generations may have a harder time adapting to high-sugar modern diets.
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Affiliation(s)
- Richard G Melvin
- Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland.,Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Nicole Lamichane
- Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland.,Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Essi Havula
- Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland.,Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Krista Kokki
- Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland.,Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Charles Soeder
- Biology Department, The University of North Carolina at Chapel Hill, Carolina, United States
| | - Corbin D Jones
- Biology Department, The University of North Carolina at Chapel Hill, Carolina, United States
| | - Ville Hietakangas
- Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland.,Institute of Biotechnology, University of Helsinki, Helsinki, Finland
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11
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Aw WC, Towarnicki SG, Melvin RG, Youngson NA, Garvin MR, Hu Y, Nielsen S, Thomas T, Pickford R, Bustamante S, Vila-Sanjurjo A, Smyth GK, Ballard JWO. Genotype to phenotype: Diet-by-mitochondrial DNA haplotype interactions drive metabolic flexibility and organismal fitness. PLoS Genet 2018; 14:e1007735. [PMID: 30399141 PMCID: PMC6219761 DOI: 10.1371/journal.pgen.1007735] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Accepted: 10/02/2018] [Indexed: 02/07/2023] Open
Abstract
Diet may be modified seasonally or by biogeographic, demographic or cultural shifts. It can differentially influence mitochondrial bioenergetics, retrograde signalling to the nuclear genome, and anterograde signalling to mitochondria. All these interactions have the potential to alter the frequencies of mtDNA haplotypes (mitotypes) in nature and may impact human health. In a model laboratory system, we fed four diets varying in Protein: Carbohydrate (P:C) ratio (1:2, 1:4, 1:8 and 1:16 P:C) to four homoplasmic Drosophila melanogaster mitotypes (nuclear genome standardised) and assayed their frequency in population cages. When fed a high protein 1:2 P:C diet, the frequency of flies harbouring Alstonville mtDNA increased. In contrast, when fed the high carbohydrate 1:16 P:C food the incidence of flies harbouring Dahomey mtDNA increased. This result, driven by differences in larval development, was generalisable to the replacement of the laboratory diet with fruits having high and low P:C ratios, perturbation of the nuclear genome and changes to the microbiome. Structural modelling and cellular assays suggested a V161L mutation in the ND4 subunit of complex I of Dahomey mtDNA was mildly deleterious, reduced mitochondrial functions, increased oxidative stress and resulted in an increase in larval development time on the 1:2 P:C diet. The 1:16 P:C diet triggered a cascade of changes in both mitotypes. In Dahomey larvae, increased feeding fuelled increased β-oxidation and the partial bypass of the complex I mutation. Conversely, Alstonville larvae upregulated genes involved with oxidative phosphorylation, increased glycogen metabolism and they were more physically active. We hypothesise that the increased physical activity diverted energy from growth and cell division and thereby slowed development. These data further question the use of mtDNA as an assumed neutral marker in evolutionary and population genetic studies. Moreover, if humans respond similarly, we posit that individuals with specific mtDNA variations may differentially metabolise carbohydrates, which has implications for a variety of diseases including cardiovascular disease, obesity, and perhaps Parkinson's Disease.
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Affiliation(s)
- Wen C. Aw
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, NSW, Australia
| | - Samuel G. Towarnicki
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, NSW, Australia
| | - Richard G. Melvin
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, NSW, Australia
| | - Neil A. Youngson
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, NSW, Australia
| | - Michael R. Garvin
- School of Biological Sciences, Washington State University, Pullman, Washington, United States of America
| | - Yifang Hu
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria, Australia
| | - Shaun Nielsen
- Centre for Marine Bio-Innovation and School of Biological, Earth and Environmental Sciences, The University of New South Wales, Sydney, NSW, Australia
| | - Torsten Thomas
- Centre for Marine Bio-Innovation and School of Biological, Earth and Environmental Sciences, The University of New South Wales, Sydney, NSW, Australia
| | - Russell Pickford
- Bioanalytical Mass Spectrometry Facility, Mark Wainwright Analytical Center, The University of New South Wales, Sydney, NSW, Australia
| | - Sonia Bustamante
- Bioanalytical Mass Spectrometry Facility, Mark Wainwright Analytical Center, The University of New South Wales, Sydney, NSW, Australia
| | - Antón Vila-Sanjurjo
- Grupo GIBE, Bioloxía Celular e Molecular, Facultade de Ciencias, Universidade da Coruña (UDC), Campus Zapateira s/n, A Coruña, Spain
| | - Gordon K. Smyth
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria, Australia
- School of Mathematics and Statistics, The University of Melbourne, Melbourne, Victoria, Australia
| | - J. William O. Ballard
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, NSW, Australia
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12
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Buchanan JL, Meiklejohn CD, Montooth KL. Mitochondrial Dysfunction and Infection Generate Immunity-Fecundity Tradeoffs in Drosophila. Integr Comp Biol 2018; 58:591-603. [PMID: 29945242 PMCID: PMC6145415 DOI: 10.1093/icb/icy078] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Physiological responses to short-term environmental stressors, such as infection, can have long-term consequences for fitness, particularly if the responses are inappropriate or nutrient resources are limited. Genetic variation affecting energy acquisition, storage, and usage can limit cellular energy availability and may influence resource-allocation tradeoffs even when environmental nutrients are plentiful. Here, we utilized Drosophila mitochondrial-nuclear genotypes to test whether disrupted mitochondrial function interferes with nutrient-sensing pathways, and whether this disruption has consequences for tradeoffs between immunity and fecundity. We found that an energetically-compromised genotype was relatively resistant to rapamycin-a drug that targets nutrient-sensing pathways and mimics resource limitation. Dietary resource limitation decreased survival of energetically-compromised flies. Furthermore, survival of infection with a natural pathogen was decreased in this genotype, and females of this genotype experienced immunity-fecundity tradeoffs that were not evident in genotypic controls with normal energy metabolism. Together, these results suggest that this genotype may have little excess energetic capacity and fewer cellular nutrients, even when environmental nutrients are not limiting. Genetic variation in energy metabolism may therefore act to limit the resources available for allocation to life-history traits in ways that generate tradeoffs even when environmental resources are not limiting.
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Affiliation(s)
- Justin L Buchanan
- School of Biological Sciences, University of Nebraska–Lincoln, 1104 T St, Lincoln, NE 68588-0118, USA
| | - Colin D Meiklejohn
- School of Biological Sciences, University of Nebraska–Lincoln, 1104 T St, Lincoln, NE 68588-0118, USA
| | - Kristi L Montooth
- School of Biological Sciences, University of Nebraska–Lincoln, 1104 T St, Lincoln, NE 68588-0118, USA
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13
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Regulation of Carbohydrate Energy Metabolism in Drosophila melanogaster. Genetics 2018; 207:1231-1253. [PMID: 29203701 DOI: 10.1534/genetics.117.199885] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Accepted: 07/02/2017] [Indexed: 02/08/2023] Open
Abstract
Carbohydrate metabolism is essential for cellular energy balance as well as for the biosynthesis of new cellular building blocks. As animal nutrient intake displays temporal fluctuations and each cell type within the animal possesses specific metabolic needs, elaborate regulatory systems are needed to coordinate carbohydrate metabolism in time and space. Carbohydrate metabolism is regulated locally through gene regulatory networks and signaling pathways, which receive inputs from nutrient sensors as well as other pathways, such as developmental signals. Superimposed on cell-intrinsic control, hormonal signaling mediates intertissue information to maintain organismal homeostasis. Misregulation of carbohydrate metabolism is causative for many human diseases, such as diabetes and cancer. Recent work in Drosophila melanogaster has uncovered new regulators of carbohydrate metabolism and introduced novel physiological roles for previously known pathways. Moreover, genetically tractable Drosophila models to study carbohydrate metabolism-related human diseases have provided new insight into the mechanisms of pathogenesis. Due to the high degree of conservation of relevant regulatory pathways, as well as vast possibilities for the analysis of gene-nutrient interactions and tissue-specific gene function, Drosophila is emerging as an important model system for research on carbohydrate metabolism.
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Ge LQ, Huang B, Li X, Gu HT, Zheng S, Zhou Z, Miao H, Wu JC. Silencing pyruvate kinase (NlPYK) leads to reduced fecundity in brown planthoppers, Nilaparvata lugens (Stål) (Hemiptera: Delphacidae). ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY 2017; 96:e21429. [PMID: 29114912 DOI: 10.1002/arch.21429] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Pyruvate kinase (PYK) operates in the glycolytic pathway, responsible for regulating the balance between glycolysis and gluconeogenesis. The previous work indicates PYK acts in development of Drosophila embryos and in embryonic muscle growth, from which it may be inferred that PYK acts in insect fecundity. More to the point, as a central enzyme in the glycolytic pathway, PYK acts in many energy-spending functions in most organisms. On the background findings that triazophos (TZP) stimulates fecundity via increase activities of several genes in brown planthoppers, Nilaparvata lugens, we investigated the combined influence of TZP and silencing a N. lugens PYK (NlPYK) on reproduction-linked biological performance parameters. Here, we report that TZP+dsNlPYK treatments led to reduced (by 26%) ovarian, but not fat body, protein content relative to controls. Ovarian (35%) and fat body (54%) soluble sugar contents were reduced. TZP+dsNlPYK treatments also led to reduced (by about 24%) fecundity, expressed as numbers of eggs laid. These data show directly that NlPYK acts in insect fecundity, probably via increases in glucose metabolism.
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Affiliation(s)
- Lin-Quan Ge
- School of Horticulture and Plant Protection, Yangzhou University, Yangzhou, P. R. China
| | - Bo Huang
- School of Horticulture and Plant Protection, Yangzhou University, Yangzhou, P. R. China
| | - Xin Li
- School of Horticulture and Plant Protection, Yangzhou University, Yangzhou, P. R. China
| | - Hao-Tian Gu
- School of Horticulture and Plant Protection, Yangzhou University, Yangzhou, P. R. China
| | - Sui Zheng
- School of Horticulture and Plant Protection, Yangzhou University, Yangzhou, P. R. China
| | - Ze Zhou
- School of Horticulture and Plant Protection, Yangzhou University, Yangzhou, P. R. China
| | - Hong Miao
- College of Mechanical Engineering, Yangzhou University, Yangzhou, P. R. China
| | - Jin-Cai Wu
- School of Horticulture and Plant Protection, Yangzhou University, Yangzhou, P. R. China
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Morten KJ, Potter M, Badder L, Sivathondan P, Dragovic R, Neumann A, Gavin J, Shrestha R, Reilly S, Phadwal K, Lodge TA, Borzychowski A, Cookson S, Mitchell C, Morovat A, Simon AK, Uusimaa J, Hynes J, Poulton J. Insights into pancreatic β cell energy metabolism using rodent β cell models. Wellcome Open Res 2017; 2:14. [DOI: 10.12688/wellcomeopenres.10535.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/14/2019] [Indexed: 11/20/2022] Open
Abstract
Background: Mitochondrial diabetes is primarily caused by β-cell failure, a cell type whose unique properties are important in pathogenesis. Methods: By reducing glucose, we induced energetic stress in two rodent β-cell models to assess effects on cellular function. Results: Culturing rat insulin-secreting INS-1 cells in low glucose conditions caused a rapid reduction in whole cell respiration, associated with elevated mitochondrial reactive oxygen species production, and an altered glucose-stimulated insulin secretion profile. Prolonged exposure to reduced glucose directly impaired mitochondrial function and reduced autophagy. Conclusions: Insulinoma cell lines have a very different bioenergetic profile to many other cell lines and provide a useful model of mechanisms affecting β-cell mitochondrial function.
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Towarnicki SG, Ballard JWO. Drosophila mitotypes determine developmental time in a diet and temperature dependent manner. JOURNAL OF INSECT PHYSIOLOGY 2017; 100:133-139. [PMID: 28619466 DOI: 10.1016/j.jinsphys.2017.06.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Revised: 06/05/2017] [Accepted: 06/07/2017] [Indexed: 06/07/2023]
Abstract
It is well known that specific mitochondrial (mt) DNA mutations can reduce organismal fitness and influence mitochondrial-nuclear interactions. However, determining specific mtDNA mutations that are beneficial has been elusive. In this study, we vary the diet and environmental temperature to study larval development time of two Drosophila melanogaster mitotypes (Alstonville and Dahomey), in two nuclear genetic backgrounds, and investigate developmental differences through weight, feeding rate, and movement. To manipulate the diet, we utilize the nutritional geometric framework to manipulate isocaloric diets of differing macronutrient ratios (1:2 and 1:16 protein: carbohydrate (P:C) ratios) and raise flies at three temperatures (19°C, 23°C and 27°C). Larvae with Dahomey mtDNA develop more slowly than Alstonville when fed the 1:2 P:C diet at all temperatures and developed more quickly when fed the 1:16 P:C diet at 23°C and 27°C. We determined that Dahomey larvae eat more, move less, and weigh more than Alstonville larvae when raised on the 1:16 P:C diet and that these physiological responses are modified by temperature. We suggest that 1 (or more) of 4 mtDNA changes is likely responsible for the observed effects and posit the mtDNA changes moderate a physiological trade-off between consumption and foraging.
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Affiliation(s)
- Samuel G Towarnicki
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia.
| | - J William O Ballard
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia.
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17
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Yasugi T, Yamada T, Nishimura T. Adaptation to dietary conditions by trehalose metabolism in Drosophila. Sci Rep 2017; 7:1619. [PMID: 28487555 PMCID: PMC5431645 DOI: 10.1038/s41598-017-01754-9] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Accepted: 04/03/2017] [Indexed: 02/05/2023] Open
Abstract
Trehalose is a non-reducing disaccharide that serves as the main sugar component of haemolymph in insects. Trehalose hydrolysis enzyme, called trehalase, is highly conserved from bacteria to humans. However, our understanding of the physiological role of trehalase remains incomplete. Here, we analyze the phenotypes of several Trehalase (Treh) loss-of-function alleles in a comparative manner in Drosophila. The previously reported mutant phenotype of Treh affecting neuroepithelial stem cell maintenance and differentiation in the optic lobe is caused by second-site alleles in addition to Treh. We further report that the survival rate of Treh null mutants is significantly influenced by dietary conditions. Treh mutant larvae are lethal not only on a low-sugar diet but also under low-protein diet conditions. A reduction in adaptation ability under poor food conditions in Treh mutants is mainly caused by the overaccumulation of trehalose rather than the loss of Treh, because the additional loss of Tps1 mitigates the lethal effect of Treh mutants. These results demonstrate that proper trehalose metabolism plays a critical role in adaptation under various environmental conditions.
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Affiliation(s)
- Tetsuo Yasugi
- Laboratory for Growth Control Signaling, RIKEN Center for Developmental Biology (CDB), 2-2-3 Minatojima-Minamimachi, Chuo-ku, Kobe, Hyogo, 650-0047, Japan.,Mathematical Neuroscience Unit, Institute for Frontier Science Initiative, Kanazawa University, 13-1 Takaramachi, Kanazawa, Ishikawa, 920-8640, Japan
| | - Takayuki Yamada
- Laboratory for Growth Control Signaling, RIKEN Center for Developmental Biology (CDB), 2-2-3 Minatojima-Minamimachi, Chuo-ku, Kobe, Hyogo, 650-0047, Japan
| | - Takashi Nishimura
- Laboratory for Growth Control Signaling, RIKEN Center for Developmental Biology (CDB), 2-2-3 Minatojima-Minamimachi, Chuo-ku, Kobe, Hyogo, 650-0047, Japan.
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18
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Morten KJ, Potter M, Badder L, Sivathondan P, Dragovic R, Neumann A, Gavin J, Shrestha R, Reilly S, Phadwal K, Lodge TA, Borzychowski A, Cookson S, Mitchell C, Morovat A, Simon AK, Uusimaa J, Hynes J, Poulton J. Insights into pancreatic β cell energy metabolism using rodent β cell models. Wellcome Open Res 2017; 2:14. [DOI: 10.12688/wellcomeopenres.10535.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/10/2017] [Indexed: 11/20/2022] Open
Abstract
Background:Mitochondrial diabetes is primarily caused by β-cell failure, but there are gaps in our understanding of pathogenesis.Methods:By reducing glucose, we induced energetic stress in two rodent β-cell models to assess effects on cellular function.Results:Culturing rat insulin-secreting INS-1 cells in low glucose conditions caused a rapid reduction in whole cell respiration, associated with elevated mitochondrial reactive oxygen species production, and an altered glucose-stimulated insulin secretion profile. Prolonged exposure to reduced glucose directly impaired mitochondrial function and reduced autophagy.Conclusions:Insulinoma cell lines provide a useful model of mechanisms affecting β-cell mitochondrial function or studying mitochondrial associated drug toxicity.
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Correction: Mitochondrial Dysfunction Plus High-Sugar Diet Provokes a Metabolic Crisis That Inhibits Growth. PLoS One 2016; 11:e0151421. [PMID: 26954062 PMCID: PMC4783076 DOI: 10.1371/journal.pone.0151421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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20
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Akdoğan E, Tardu M, Garipler G, Baytek G, Kavakli İH, Dunn CD. Reduced Glucose Sensation Can Increase the Fitness of Saccharomyces cerevisiae Lacking Mitochondrial DNA. PLoS One 2016; 11:e0146511. [PMID: 26751567 PMCID: PMC4709096 DOI: 10.1371/journal.pone.0146511] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Accepted: 12/19/2015] [Indexed: 12/12/2022] Open
Abstract
Damage to the mitochondrial genome (mtDNA) can lead to diseases for which there are no clearly effective treatments. Since mitochondrial function and biogenesis are controlled by the nutrient environment of the cell, it is possible that perturbation of conserved, nutrient-sensing pathways may successfully treat mitochondrial disease. We found that restricting glucose or otherwise reducing the activity of the protein kinase A (PKA) pathway can lead to improved proliferation of Saccharomyces cerevisiae cells lacking mtDNA and that the transcriptional response to mtDNA loss is reduced in cells with diminished PKA activity. We have excluded many pathways and proteins from being individually responsible for the benefits provided to cells lacking mtDNA by PKA inhibition, and we found that robust import of mitochondrial polytopic membrane proteins may be required in order for cells without mtDNA to receive the full benefits of PKA reduction. Finally, we have discovered that the transcription of genes involved in arginine biosynthesis and aromatic amino acid catabolism is altered after mtDNA damage. Our results highlight the potential importance of nutrient detection and availability on the outcome of mitochondrial dysfunction.
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Affiliation(s)
- Emel Akdoğan
- Department of Molecular Biology and Genetics, Koç University, Sarıyer, İstanbul, 34450, Turkey
| | - Mehmet Tardu
- Department of Chemical and Biological Engineering, Koç University, Sarıyer, İstanbul, 34450, Turkey
| | - Görkem Garipler
- Department of Molecular Biology and Genetics, Koç University, Sarıyer, İstanbul, 34450, Turkey
| | - Gülkız Baytek
- Department of Molecular Biology and Genetics, Koç University, Sarıyer, İstanbul, 34450, Turkey
| | - İ. Halil Kavakli
- Department of Molecular Biology and Genetics, Koç University, Sarıyer, İstanbul, 34450, Turkey
- Department of Chemical and Biological Engineering, Koç University, Sarıyer, İstanbul, 34450, Turkey
| | - Cory D. Dunn
- Department of Molecular Biology and Genetics, Koç University, Sarıyer, İstanbul, 34450, Turkey
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