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Son W, Jeong HS, Nam DE, Lee AJ, Nam SH, Lee JE, Choi BO, Chung KW. Peripheral Neuropathy and Decreased Locomotion of a RAB40B Mutation in Human and Model Animals. Exp Neurobiol 2023; 32:410-422. [PMID: 38196136 PMCID: PMC10789172 DOI: 10.5607/en23027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 12/13/2023] [Accepted: 12/15/2023] [Indexed: 01/11/2024] Open
Abstract
Rab40 proteins are an atypical subgroup of Rab GTPases containing a unique suppressor of the cytokine signaling (SOCS) domain that is recruited to assemble the CRL5 E3 ligase complex for proteolytic regulation in various biological processes. A nonsense mutation deleting the C-terminal SOCS box in the RAB40B gene was identified in a family with axonal peripheral neuropathy (Charcot-Marie-Tooth disease type 2), and pathogenicity of the mutation was assessed in model organisms of zebrafish and Drosophila. Compared to control fish, zebrafish larvae transformed by the human mutant hRAB40B-Y83X showed a defective swimming pattern of stalling with restricted localization and slower motility. We were consistently able to observe reduced labeling of synaptic markers along neuromuscular junctions of the transformed larvae. In addition to the neurodevelopmental phenotypes, compared to normal hRAB40B expression, we further examined ectopic expression of hRAB40B-Y83X in Drosophila to show a progressive decline of locomotion ability. Decreased ability of locomotion by ubiquitous expression of the human mutation was reproduced not with GAL4 drivers for neuron-specific expression but only when a pan-glial GAL4 driver was applied. Using the ectopic expression model of Drosophila, we identified a genetic interaction in which Cul5 down regulation exacerbated the defective motor performance, showing a consistent loss of SOCS box of the pathogenic RAB40B. Taken together, we could assess the possible gain-of-function of the human RAB40B mutation by comparing behavioral phenotypes in animal models; our results suggest that the mutant phenotypes may be associated with CRL5-mediated proteolytic regulation.
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Affiliation(s)
- Wonseok Son
- Department of Biological Sciences and BK21 Team for Field-oriented BioCore Human Resources Development, Kongju National University, Gongju 32588, Korea
| | - Hui Su Jeong
- Department of Health Sciences and Technology, Samsung Advanced Institute for Health Sciences & Technology, Sungkyunkwan University, Seoul 06351, Korea
| | - Da Eun Nam
- Department of Biological Sciences and BK21 Team for Field-oriented BioCore Human Resources Development, Kongju National University, Gongju 32588, Korea
| | - Ah Jin Lee
- Department of Biological Sciences and BK21 Team for Field-oriented BioCore Human Resources Development, Kongju National University, Gongju 32588, Korea
| | - Soo Hyun Nam
- Cell and Gene Therapy Institute, Samsung Medical Center, Seoul 06351, Korea
| | - Ji Eun Lee
- Department of Health Sciences and Technology, Samsung Advanced Institute for Health Sciences & Technology, Sungkyunkwan University, Seoul 06351, Korea
- Samsung Biomedical Research Institute, Samsung Medical Center, Seoul 06351, Korea
| | - Byung-Ok Choi
- Department of Health Sciences and Technology, Samsung Advanced Institute for Health Sciences & Technology, Sungkyunkwan University, Seoul 06351, Korea
- Cell and Gene Therapy Institute, Samsung Medical Center, Seoul 06351, Korea
- Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 06351, Korea
| | - Ki Wha Chung
- Department of Biological Sciences and BK21 Team for Field-oriented BioCore Human Resources Development, Kongju National University, Gongju 32588, Korea
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Brischigliaro M, Fernandez-Vizarra E, Viscomi C. Mitochondrial Neurodegeneration: Lessons from Drosophila melanogaster Models. Biomolecules 2023; 13:378. [PMID: 36830747 PMCID: PMC9953451 DOI: 10.3390/biom13020378] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Revised: 02/09/2023] [Accepted: 02/13/2023] [Indexed: 02/19/2023] Open
Abstract
The fruit fly-i.e., Drosophila melanogaster-has proven to be a very useful model for the understanding of basic physiological processes, such as development or ageing. The availability of straightforward genetic tools that can be used to produce engineered individuals makes this model extremely interesting for the understanding of the mechanisms underlying genetic diseases in physiological models. Mitochondrial diseases are a group of yet-incurable genetic disorders characterized by the malfunction of the oxidative phosphorylation system (OXPHOS), which is the highly conserved energy transformation system present in mitochondria. The generation of D. melanogaster models of mitochondrial disease started relatively recently but has already provided relevant information about the molecular mechanisms and pathological consequences of mitochondrial dysfunction. Here, we provide an overview of such models and highlight the relevance of D. melanogaster as a model to study mitochondrial disorders.
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Affiliation(s)
- Michele Brischigliaro
- Department of Biomedical Sciences, University of Padova, 35131 Padova, Italy
- Veneto Institute of Molecular Medicine, 35129 Padova, Italy
| | - Erika Fernandez-Vizarra
- Department of Biomedical Sciences, University of Padova, 35131 Padova, Italy
- Veneto Institute of Molecular Medicine, 35129 Padova, Italy
| | - Carlo Viscomi
- Department of Biomedical Sciences, University of Padova, 35131 Padova, Italy
- Veneto Institute of Molecular Medicine, 35129 Padova, Italy
- Centre for the Study of Neurodegeneration (CESNE), University of Padova, 35131 Padova, Italy
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A Drosophila model of the neurological symptoms in Mpv17-related diseases. Sci Rep 2022; 12:22632. [PMID: 36587049 PMCID: PMC9805426 DOI: 10.1038/s41598-022-27329-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Accepted: 12/30/2022] [Indexed: 01/01/2023] Open
Abstract
Mutations in the Mpv17 gene are responsible for MPV17-related hepatocerebral mitochondrial DNA depletion syndrome and Charcot-Marie-Tooth (CMT) disease. Although several models including mouse, zebrafish, and cultured human cells, have been developed, the models do not show any neurological defects, which are often observed in patients. Therefore, we knocked down CG11077 (Drosophila Mpv17; dMpv17), an ortholog of human MPV17, in the nervous system in Drosophila melanogaster and investigated the behavioral and cellular phenotypes. The resulting dMpv17 knockdown larvae showed impaired locomotor activity and learning ability consistent with mitochondrial defects suggested by the reductions in mitochondrial DNA and ATP production and the increases in the levels of lactate and reactive oxygen species. Furthermore, an abnormal morphology of the neuromuscular junction, at the presynaptic terminal, was observed in dMpv17 knockdown larvae. These results reproduce well the symptoms of human diseases and partially reproduce the phenotypes of Mpv17-deficient model organisms. Therefore, we suggest that neuron-specific dMpv17 knockdown in Drosophila is a useful model for investigation of MPV17-related hepatocerebral mitochondrial DNA depletion syndrome and CMT caused by Mpv17 dysfunction.
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Burke R. Molecular physiology of copper in Drosophila melanogaster. CURRENT OPINION IN INSECT SCIENCE 2022; 51:100892. [PMID: 35247643 DOI: 10.1016/j.cois.2022.100892] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 02/16/2022] [Accepted: 02/17/2022] [Indexed: 06/14/2023]
Abstract
In this review, I look at advances made in our understanding of the molecular physiology of copper homeostasis in the vinegar fly Drosophila melanogaster over the past five years, focussing in particular on the most recent 24 months. Firstly, I review publications investigating the physiological and genetic basis of dietary copper toxicity and tolerance, with particular attention paid to the identification of novel transcriptional and post translational regulators of copper homeostasis. Then I hone in on the growing body of evidence linking copper dysregulation with aberrant neuronal development and function.
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Affiliation(s)
- Richard Burke
- Monash University, School of Biological Sciences, Australia.
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