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Yildiz EP, Kilic MA, Yalcin EU, Kurekci F, Avci R, Hacıfazlıoğlu NE, Ceylaner S, Gezdirici A, Çalışkan M. Genetic and clinical evaluation of congenital myasthenic syndromes with long-term follow-up: experience of a tertiary center in Turkey. Acta Neurol Belg 2023; 123:1841-1847. [PMID: 36094697 DOI: 10.1007/s13760-022-02090-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Accepted: 09/01/2022] [Indexed: 11/30/2022]
Abstract
INTRODUCTION Congenital myasthenic syndromes (CMS) are a heterogeneous group of genetic disorders affecting the safety factor which required for neuromuscular transmission. Here we reported our experience in children with CMS. METHODS We retrospectively collected the data of 18 patients with CMS who were examined in our outpatient clinic between January 2021 and January 2022. The diagnosis of CMS was based on the presence of clinical symptoms such as abnormal fatigability and weakness, absence of autoantibodies against acetylcholine receptor and muscle-specific kinase, electromyographic evidence of neuromuscular junction defect, molecular genetic confirmation, and response to treatment. RESULTS The most common mutations were in the acetylcholine receptor (CHRNE) gene (8/18) and choline acetyltransferase (ChAT) (2/18) gene. Despite targeted gene sequencing and whole exome sequencing (WES) were underwent, we couldn't detect a genetic mutation in three out of patients. The most commonly determined initial finding was eyelid ptosis, followed by fatigable weakness, and respiratory insufficiency. Although the most commonly used drug was pyridostigmine, we have experienced that caution should be exercised as it may worsen some types of CMS. DISCUSSION We reported in detail the phenotypic features of very rare gene mutations associated with CMS and our experience in the treatment of this disease. Although CMS are rare genetic disorder, the prognosis can be very promising with appropriate treatment in most CMS subtypes.
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Affiliation(s)
- Edibe Pembegul Yildiz
- Department of Pediatric Neurology, Istanbul Medical Faculty, Istanbul, Turkey.
- Istanbul University Institute of Child Health, Istanbul, Turkey.
- Istanbul University Medical School. Millet Cd, 34000, Fatih-Istanbul, Turkey.
| | - Mehmet Akif Kilic
- Department of Pediatric Neurology, Istanbul Medical Faculty, Istanbul, Turkey
| | - Emek Uyur Yalcin
- Department of Pediatric Neurology, Zeynep Kamil Maternity and Children's Diseases Training and Research Hospital, University of Health Sciences, Istanbul, Turkey
| | - Fulya Kurekci
- Department of Pediatric Neurology, Istanbul Medical Faculty, Istanbul, Turkey
| | - Ridvan Avci
- Department of Pediatric Neurology, Istanbul Medical Faculty, Istanbul, Turkey
| | - Nilüfer Eldeş Hacıfazlıoğlu
- Department of Pediatric Neurology, Zeynep Kamil Maternity and Children's Diseases Training and Research Hospital, University of Health Sciences, Istanbul, Turkey
| | | | - Alper Gezdirici
- Department of Medical Genetics, Basaksehir Cam and Sakura City Hospital, Istanbul, Turkey
| | - Mine Çalışkan
- Department of Pediatric Neurology, Istanbul Medical Faculty, Istanbul, Turkey
- Istanbul University Institute of Child Health, Istanbul, Turkey
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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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Complex hereditary peripheral neuropathies caused by novel variants in mitochondrial-related nuclear genes. J Neurol 2022; 269:4129-4140. [PMID: 35235001 PMCID: PMC9293870 DOI: 10.1007/s00415-022-11026-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Revised: 02/05/2022] [Accepted: 02/11/2022] [Indexed: 11/04/2022]
Abstract
Mitochondrial disorders are a group of clinically and genetically heterogeneous multisystem disorders and peripheral neuropathy is frequently described in the context of mutations in mitochondrial-related nuclear genes. This study aimed to identify the causative mutations in mitochondrial-related nuclear genes in suspected hereditary peripheral neuropathy patients. We enrolled a large Japanese cohort of clinically suspected hereditary peripheral neuropathy patients who were mutation negative in the prescreening of the known Charcot–Marie–Tooth disease-causing genes. We performed whole-exome sequencing on 247 patients with autosomal recessive or sporadic inheritance for further analysis of 167 mitochondrial-related nuclear genes. We detected novel bi-allelic likely pathogenic/pathogenic variants in four patients, from four mitochondrial-related nuclear genes: pyruvate dehydrogenase beta-polypeptide (PDHB), mitochondrial poly(A) polymerase (MTPAP), hydroxyacyl-CoA dehydrogenase/3-ketoacyl-CoA thiolase/enoyl-CoA hydratase, beta subunit (HADHB), and succinate-CoA ligase ADP-forming beta subunit (SUCLA2). All these patients showed sensory and motor axonal polyneuropathy, combined with central nervous system or multisystem involvements. The pathological analysis of skeletal muscles revealed mild neurogenic changes without significant mitochondrial abnormalities. Targeted screening of mitochondria-related nuclear genes should be considered for patients with complex hereditary axonal polyneuropathy, accompanied by central nervous system dysfunctions, or with unexplainable multisystem disorders.
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Bali KK, Gandla J, Rangel DR, Castaldi L, Mouritzen P, Agarwal N, Schmelz M, Heppenstall P, Kuner R. A genome-wide screen reveals microRNAs in peripheral sensory neurons driving painful diabetic neuropathy. Pain 2021; 162:1334-1351. [PMID: 33492037 DOI: 10.1097/j.pain.0000000000002159] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Accepted: 11/23/2020] [Indexed: 12/25/2022]
Abstract
ABSTRACT Diabetes is a leading cause of peripheral neuropathy (diabetic peripheral neuropathy, DPN), and uncontrolled long-lasting hyperglycemia leads to severe complications. A major proportion of diabetics develop excruciating pain with a variable course. Mechanisms leading to painful DPN are not completely understood and treatment options limited. We hypothesized that epigenetic modulation at the level of microRNA (miRNA) expression triggered by metabolic imbalance and nerve damage regulates the course of pain development. We used clinically relevant preclinical models, genome-wide screening, in silico analyses, cellular assays, miRNA fluorescent in situ hybridization, in vivo molecular manipulations, and behavioral analyses in the current study. We identified miRNAs and their targets that critically impact on nociceptive hypersensitivity in painful DPN. Our analyses identify miR-33 and miR-380 expressed in nociceptive neurons as critical denominators of diabetic pain and miR-124-1 as a mediator of physiological nociception. Our comprehensive analyses on the putative mRNA targets for miR-33 or miR-124-1 identified a set of mRNAs that are regulated after miR-33 or miR-124-1 overexpression in dorsal root ganglia in vivo. Our results shed light on the regulation of DPN pathophysiology and implicate specific miRNAs as novel therapeutic targets for treating painful DPN.
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Affiliation(s)
- Kiran Kumar Bali
- Department of Molecular Pharmacology, Pharmacology Institute, Medical Faculty Heidelberg, Heidelberg University, Heidelberg, Germany . Dr. Bali is now with the Department of Experimental Pain Research, Mannheim Center for Translational Neuroscience (MCTN), Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Jagadeesh Gandla
- Department of Molecular Pharmacology, Pharmacology Institute, Medical Faculty Heidelberg, Heidelberg University, Heidelberg, Germany . Dr. Bali is now with the Department of Experimental Pain Research, Mannheim Center for Translational Neuroscience (MCTN), Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Daniel Rojas Rangel
- Department of Molecular Pharmacology, Pharmacology Institute, Medical Faculty Heidelberg, Heidelberg University, Heidelberg, Germany . Dr. Bali is now with the Department of Experimental Pain Research, Mannheim Center for Translational Neuroscience (MCTN), Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | | | | | - Nitin Agarwal
- Department of Molecular Pharmacology, Pharmacology Institute, Medical Faculty Heidelberg, Heidelberg University, Heidelberg, Germany . Dr. Bali is now with the Department of Experimental Pain Research, Mannheim Center for Translational Neuroscience (MCTN), Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Martin Schmelz
- Department of Experimental Pain Research, Mannheim Center for Translational Neuroscience (MCTN), Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | | | - Rohini Kuner
- Department of Molecular Pharmacology, Pharmacology Institute, Medical Faculty Heidelberg, Heidelberg University, Heidelberg, Germany . Dr. Bali is now with the Department of Experimental Pain Research, Mannheim Center for Translational Neuroscience (MCTN), Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
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Dagher R, Massie R, Gentil BJ. MTP deficiency caused by HADHB mutations: Pathophysiology and clinical manifestations. Mol Genet Metab 2021; 133:1-7. [PMID: 33744096 DOI: 10.1016/j.ymgme.2021.03.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 03/08/2021] [Accepted: 03/09/2021] [Indexed: 12/17/2022]
Abstract
Mutations in the HADHB gene lead to Mitochondrial Trifunctional Protein (MTP) deficiency. MTP deficiency is a rare autosomal recessive disorder affecting long-chain fatty acid oxidation. Patients affected by MTP deficiency are unable to metabolize long-chain fatty-acids and suffer a variety of symptoms exacerbated during fasting. The three phenotypes associated with complete MTP deficiency are an early-onset cardiomyopathy and early death, an intermediate form with recurrent hypoketotic hypoglycemia and a sensorimotor neuropathy with episodic rhabdomyolysis with small amount of residual enzyme activities. This review aims to discuss the pathophysiological mechanisms and clinical manifestations of each phenotype, which appears different and linked to HADHB expression levels. Notably, the pathophysiology of the sensorimotor neuropathy is relatively unknown and we provide a hypothesis on the qualitative aspect of the role of acylcarnitine buildup in Schwann cells in MTP deficiency patients. We propose that acylcarnitine may exit the Schwann cell and alter membrane properties of nearby axons leading to axonal degeneration based on recent findings in different metabolic disorders.
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Affiliation(s)
- Robin Dagher
- Department of Kinesiology and Physical Education, McGill University, Montreal, QC H3A 2B4, Canada
| | - Rami Massie
- Department of Neurology/Neurosurgery, McGill University, Montreal, QC H3A 2B4, Canada
| | - Benoit J Gentil
- Department of Kinesiology and Physical Education, McGill University, Montreal, QC H3A 2B4, Canada; Department of Neurology/Neurosurgery, McGill University, Montreal, QC H3A 2B4, Canada.
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Yamaguchi M, Lee IS, Jantrapirom S, Suda K, Yoshida H. Drosophila models to study causative genes for human rare intractable neurological diseases. Exp Cell Res 2021; 403:112584. [PMID: 33812867 DOI: 10.1016/j.yexcr.2021.112584] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 03/25/2021] [Accepted: 03/27/2021] [Indexed: 12/11/2022]
Abstract
Drosophila is emerging as a convenient model for investigating human diseases. Functional homologues of almost 75% of human disease-related genes are found in Drosophila. Amyotrophic lateral sclerosis (ALS) is a severe neurodegenerative disease that causes defects in motoneurons. Charcot-Marie-Tooth disease (CMT) is one of the most commonly found inherited neuropathies affecting both motor and sensory neurons. No effective therapy has been established for either of these diseases. In this review, after overviewing ALS, Drosophila models targeting several ALS-causing genes, including TDP-43, FUS and Ubiquilin2, are described with their genetic interactants. Then, after overviewing CMT, examples of Drosophila models targeting several CMT-causing genes, including mitochondria-related genes and FIG 4, are also described with their genetic interactants. In addition, we introduce Sotos syndrome caused by mutations in the epigenetic regulator gene NSD1. Lastly, several genes and pathways that commonly interact with ALS- and/or CMT-causing genes are described. In the case of ALS and CMT that have many causative genes, it may be not practical to perform gene therapy for each of the many disease-causing genes. The possible uses of the common genes and pathways as novel diagnosis markers and effective therapeutic targets are discussed.
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Affiliation(s)
- Masamitsu Yamaguchi
- Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto, 606-8585, Japan; Kansai Gakken Laboratory, Kankyo Eisei Yakuhin Co. Ltd., Seika-cho, Kyoto, 619-0237, Japan
| | - Im-Soon Lee
- Department of Biological Sciences, Konkuk University, Seoul, Republic of Korea
| | - Salinee Jantrapirom
- Department of Pharmacology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Kojiro Suda
- Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto, 606-8585, Japan
| | - Hideki Yoshida
- Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto, 606-8585, Japan.
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Yamaguchi M, Omori K, Asada S, Yoshida H. Epigenetic Regulation of ALS and CMT: A Lesson from Drosophila Models. Int J Mol Sci 2021; 22:ijms22020491. [PMID: 33419039 PMCID: PMC7825332 DOI: 10.3390/ijms22020491] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 01/01/2021] [Accepted: 01/03/2021] [Indexed: 12/11/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is the third most common neurodegenerative disorder and is sometimes associated with frontotemporal dementia. Charcot–Marie–Tooth disease (CMT) is one of the most commonly inherited peripheral neuropathies causing the slow progression of sensory and distal muscle defects. Of note, the severity and progression of CMT symptoms markedly vary. The phenotypic heterogeneity of ALS and CMT suggests the existence of modifiers that determine disease characteristics. Epigenetic regulation of biological functions via gene expression without alterations in the DNA sequence may be an important factor. The methylation of DNA, noncoding RNA, and post-translational modification of histones are the major epigenetic mechanisms. Currently, Drosophila is emerging as a useful ALS and CMT model. In this review, we summarize recent studies linking ALS and CMT to epigenetic regulation with a strong emphasis on approaches using Drosophila models.
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Affiliation(s)
- Masamitsu Yamaguchi
- Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan; (K.O.); (S.A.)
- Kansai Gakken Laboratory, Kankyo Eisei Yakuhin Co. Ltd., Seika-cho, Kyoto 619-0237, Japan
- Correspondence: (M.Y.); (H.Y.)
| | - Kentaro Omori
- Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan; (K.O.); (S.A.)
| | - Satoshi Asada
- Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan; (K.O.); (S.A.)
| | - Hideki Yoshida
- Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan; (K.O.); (S.A.)
- Correspondence: (M.Y.); (H.Y.)
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Shimizu J, Kasai T, Yoshida H, Huynh AM, Nakao-Azuma Y, Shinomoto M, Tokuda T, Mizuno T, Yamaguchi M. Novel Drosophila model for parkinsonism by targeting phosphoglycerate kinase. Neurochem Int 2020; 139:104816. [PMID: 32758590 DOI: 10.1016/j.neuint.2020.104816] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 07/16/2020] [Accepted: 07/19/2020] [Indexed: 12/24/2022]
Abstract
Patients with Parkinson's disease (PD) show a common progressive neurodegenerative movement disorder characterized by rigidity, tremors, postural instability, and bradykinesia due to the loss of dopaminergic neurons in the substantia nigra, and is often accompanied by several non-motor symptoms, called parkinsonism. Several lines of recent evidence support the hypothesis that mutations in the gene encoding phosphoglycerate kinase (PGK) play an important role in the PD mechanism. PGK is a key enzyme in the glycolytic pathway that catalyzes the reaction from 1,3-diphosphoglycerate to 3-phosphoglycerate. We herein established a parkinsonism model targeting Drosophila Pgk. Dopaminergic (DA) neuron-specific Pgk knockdown lead to locomotive defects in both young and aged adult flies and was accompanied by progressive DA neuron loss with aging. Pgk knockdown in DA neurons decreased dopamine levels in the central nervous system (CNS) of both young and aged adult flies. These phenotypes are similar to the defects observed in human PD patients, suggesting that the Pgk knockdown flies established herein are a promising model for parkinsonism. Furthermore, pan-neuron-specific Pgk knockdown induced low ATP levels and the accumulation of reactive oxygen species (ROS) in the CNS of third instar larvae. Collectively, these results indicate that a failure in the energy production system of Pgk knockdown flies causes locomotive defects accompanied by neuronal dysfunction and degeneration in DA neurons.
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Affiliation(s)
- Joe Shimizu
- Department of Applied Biology, Advanced Insect Research Promotion Center, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto, 606-8585, Japan
| | - Takashi Kasai
- Department of Neurology, Kyoto Prefectural University of Medicine, Kyoto, 602-0841, Japan.
| | - Hideki Yoshida
- Department of Applied Biology, Advanced Insect Research Promotion Center, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto, 606-8585, Japan.
| | - Anh M Huynh
- Department of Applied Biology, Advanced Insect Research Promotion Center, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto, 606-8585, Japan
| | - Yumiko Nakao-Azuma
- Department of Neurology, Kyoto Prefectural University of Medicine, Kyoto, 602-0841, Japan; Department of Rehabilitation Medicine, Gunma University Graduate School of Medicine, Gunma, Japan
| | - Makiko Shinomoto
- Department of Neurology, Kyoto Prefectural University of Medicine, Kyoto, 602-0841, Japan
| | - Takahiko Tokuda
- Department of Neurology, Kyoto Prefectural University of Medicine, Kyoto, 602-0841, Japan; Department of Molecular Pathobiology of Brain Diseases, Kyoto Prefectural University of Medicine, Kyoto, 602-0841, Japan
| | - Toshiki Mizuno
- Department of Neurology, Kyoto Prefectural University of Medicine, Kyoto, 602-0841, Japan
| | - Masamitsu Yamaguchi
- Department of Applied Biology, Advanced Insect Research Promotion Center, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto, 606-8585, Japan.
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Ali MS, Suda K, Kowada R, Ueoka I, Yoshida H, Yamaguchi M. Neuron-specific knockdown of solute carrier protein SLC25A46a induces locomotive defects, an abnormal neuron terminal morphology, learning disability, and shortened lifespan. IBRO Rep 2020; 8:65-75. [PMID: 32140609 PMCID: PMC7047145 DOI: 10.1016/j.ibror.2020.02.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Accepted: 02/17/2020] [Indexed: 01/21/2023] Open
Abstract
Various mutations in the SLC25A46 gene have been reported in mitochondrial diseases that are sometimes classified as type 2 Charcot-Marie-Tooth disease, optic atrophy, and Leigh syndrome. Although human SLC25A46 is a well-known transporter that acts through the mitochondrial outer membrane, the relationship between neurodegeneration in these diseases and the loss-of-function of SLC25A46 remains unclear. Two Drosophila genes, CG8931 (dSLC25A46a) and CG5755 (dSLC25A46b) have been identified as candidate homologs of human SLC25A46. We previously characterized the phenotypes of pan-neuron-specific dSLC25A46b knockdown flies. In the present study, we developed pan-neuron-specific dSLC25A46a knockdown flies and examined their phenotypes. Neuron-specific dSLC25A46a knockdown resulted in reduced mobility in larvae as well as adults. An aberrant morphology for neuromuscular junctions (NMJs), such as a reduced synaptic branch length and decreased number and size of boutons, was observed in dSLC25A46a knockdown flies. Learning ability was also reduced in the larvae of knockdown flies. In dSLC25A46a knockdown flies, mitochondrial hyperfusion was detected in NMJ synapses together with the accumulation of reactive oxygen species and reductions in ATP. These phenotypes were very similar to those of dSLC25A46b knockdown flies, suggesting that dSLC25A46a and dSLC25A46b do not have redundant roles in neurons. Collectively, these results show that the depletion of SLC25A46a leads to mitochondrial defects followed by an aberrant synaptic morphology, resulting in locomotive defects and learning disability. Thus, the dSLC25A46a knockdown fly summarizes most of the phenotypes in patients with mitochondrial diseases, offering a useful tool for studying these diseases.
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Affiliation(s)
- Md Saheb Ali
- Department of Applied Biology, Advanced Insect Research Promotion Center, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto, 606-8585, Japan
- Faculty of Agriculture, Bangladesh Jute Research Institute, Manik Mia Ave., Dhaka, 1207, Bangladesh
| | - Kojiro Suda
- Department of Applied Biology, Advanced Insect Research Promotion Center, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto, 606-8585, Japan
| | - Ryosuke Kowada
- Department of Applied Biology, Advanced Insect Research Promotion Center, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto, 606-8585, Japan
| | - Ibuki Ueoka
- Department of Applied Biology, Advanced Insect Research Promotion Center, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto, 606-8585, Japan
| | - Hideki Yoshida
- Department of Applied Biology, Advanced Insect Research Promotion Center, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto, 606-8585, Japan
| | - Masamitsu Yamaguchi
- Department of Applied Biology, Advanced Insect Research Promotion Center, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto, 606-8585, Japan
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Identification of CR43467 encoding a long non-coding RNA as a novel genetic interactant with dFIG4, a CMT-causing gene. Exp Cell Res 2019; 386:111711. [PMID: 31704059 DOI: 10.1016/j.yexcr.2019.111711] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Revised: 10/30/2019] [Accepted: 11/01/2019] [Indexed: 12/15/2022]
Abstract
The eye imaginal disc-specific knockdown of dFIG4, a Drosophila homolog of FIG4 that is one of the Charcot-Marie-Tooth disease (CMT)-causing genes, induces an aberrant adult compound eye morphology, the so-called rough eye phenotype. We previously performed modifier screening on the dFIG4 knockdown-induced rough eye phenotype and identified several genes, including CR18854, encoding a long non-coding RNA (lncRNA) as genetic interactants with dFIG4. In the present study, in more extensive genetic screening, we found that the deletion of a gene locus encoding both Odorant rector 46a (Or46a) and lncRNA CR43467 effectively suppressed the rough eye phenotype induced by the knockdown of dFIG4. Both genes were located on the same locus, but oriented in opposite directions. In order to identify which of these genes is responsible for the suppression of the rough eye phenotype, we established a CR43467-specific knockdown line using the CRISPR-dCas9 system. By using this system, we demonstrated that the CR43467 gene, but not the Or46a gene, genetically interacted with the dFIG4 gene. The knockdown of CR43467 rescued the reductions in the length of synaptic branches and number of boutons at neuromuscular junctions induced by the knockdown of dFIG4. The vacuole enlargement phenotype induced by the fat body-specific dFIG4 knockdown was also effectively suppressed by the knockdown of CR43467. The knockdown of CR43467 also suppressed the rough eye phenotype induced by other peripheral neuropathy-related genes, such as dCOA7, dHADHB, and dPDHB. We herein identified another gene encoding lncRNA, CR43467 as a genetic interactant with the CMT-causing gene.
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