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Ahmad RN, Zhang LT, Morita R, Tani H, Wu Y, Chujo T, Ogawa A, Harada R, Shigeta Y, Tomizawa K, Wei FY. Pathological mutations promote proteolysis of mitochondrial tRNA-specific 2-thiouridylase 1 (MTU1) via mitochondrial caseinolytic peptidase (CLPP). Nucleic Acids Res 2024; 52:1341-1358. [PMID: 38113276 PMCID: PMC10853782 DOI: 10.1093/nar/gkad1197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Revised: 11/22/2023] [Accepted: 12/01/2023] [Indexed: 12/21/2023] Open
Abstract
MTU1 controls intramitochondrial protein synthesis by catalyzing the 2-thiouridine modification of mitochondrial transfer RNAs (mt-tRNAs). Missense mutations in the MTU1 gene are associated with life-threatening reversible infantile hepatic failure. However, the molecular pathogenesis is not well understood. Here, we investigated 17 mutations associated with this disease, and our results showed that most disease-related mutations are partial loss-of-function mutations, with three mutations being particularly severe. Mutant MTU1 is rapidly degraded by mitochondrial caseinolytic peptidase (CLPP) through a direct interaction with its chaperone protein CLPX. Notably, knockdown of CLPP significantly increased mutant MTU1 protein expression and mt-tRNA 2-thiolation, suggesting that accelerated proteolysis of mutant MTU1 plays a role in disease pathogenesis. In addition, molecular dynamics simulations demonstrated that disease-associated mutations may lead to abnormal intermolecular interactions, thereby impairing MTU1 enzyme activity. Finally, clinical data analysis underscores a significant correlation between patient prognosis and residual 2-thiolation levels, which is partially consistent with the AlphaMissense predictions. These findings provide a comprehensive understanding of MTU1-related diseases, offering prospects for modification-based diagnostics and novel therapeutic strategies centered on targeting CLPP.
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Affiliation(s)
- Raja Norazireen Raja Ahmad
- Department of Molecular Physiology, Faculty of Life Sciences, Kumamoto University, Kumamoto, Kumamoto, 860-8556, Japan
- Department of Modomics Biology and Medicine, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Miyagi, 980-8575, Japan
| | - Long-Teng Zhang
- Department of Modomics Biology and Medicine, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Miyagi, 980-8575, Japan
| | - Rikuri Morita
- Center for Computational Sciences, University of Tsukuba, Tsukuba, Ibaraki, 305-8577, Japan
| | - Haruna Tani
- Department of Modomics Biology and Medicine, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Miyagi, 980-8575, Japan
| | - Yong Wu
- Department of Molecular Physiology, Faculty of Life Sciences, Kumamoto University, Kumamoto, Kumamoto, 860-8556, Japan
| | - Takeshi Chujo
- Department of Molecular Physiology, Faculty of Life Sciences, Kumamoto University, Kumamoto, Kumamoto, 860-8556, Japan
| | - Akiko Ogawa
- Department of Modomics Biology and Medicine, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Miyagi, 980-8575, Japan
| | - Ryuhei Harada
- Center for Computational Sciences, University of Tsukuba, Tsukuba, Ibaraki, 305-8577, Japan
| | - Yasuteru Shigeta
- Center for Computational Sciences, University of Tsukuba, Tsukuba, Ibaraki, 305-8577, Japan
| | - Kazuhito Tomizawa
- Department of Molecular Physiology, Faculty of Life Sciences, Kumamoto University, Kumamoto, Kumamoto, 860-8556, Japan
| | - Fan-Yan Wei
- Department of Modomics Biology and Medicine, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Miyagi, 980-8575, Japan
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Gedikbasi A, Toksoy G, Karaca M, Gulec C, Balci MC, Gunes D, Gunes S, Aslanger AD, Unverengil G, Karaman B, Basaran S, Demirkol M, Gokcay GF, Uyguner ZO. Clinical and bi-genomic DNA findings of patients suspected to have mitochondrial diseases. Front Genet 2023; 14:1191159. [PMID: 37377599 PMCID: PMC10292751 DOI: 10.3389/fgene.2023.1191159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Accepted: 05/02/2023] [Indexed: 06/29/2023] Open
Abstract
Background: Mitochondrial diseases are the most common group of inherited metabolic disorders, causing difficulties in definite diagnosis due to clinical and genetic heterogeneity. Clinical components are predominantly associated with pathogenic variants shown in nuclear or mitochondrial genomes that affect vital respiratory chain function. The development of high-throughput sequencing technologies has accelerated the elucidation of the genetic etiology of many genetic diseases that previously remained undiagnosed. Methods: Thirty affected patients from 24 unrelated families with clinical, radiological, biochemical, and histopathological evaluations considered for mitochondrial diseases were investigated. DNA isolated from the peripheral blood samples of probands was sequenced for nuclear exome and mitochondrial DNA (mtDNA) analyses. MtDNA sequencing was also performed from the muscle biopsy material in one patient. For segregation, Sanger sequencing is performed for pathogenic alterations in five other affected family members and healthy parents. Results: Exome sequencing revealed 14 different pathogenic variants in nine genes encoding mitochondrial function peptides (AARS2, EARS2, ECHS1, FBXL4, MICOS13, NDUFAF6, OXCT1, POLG, and TK2) in 12 patients from nine families and four variants in genes encoding important for muscle structure (CAPN3, DYSF, and TCAP) in six patients from four families. Three probands carried pathogenic mtDNA variations in two genes (MT-ATP6 and MT-TL1). Nine variants in five genes are reported for the first time with disease association: (AARS2: c.277C>T/p.(R93*), c.845C>G/p.(S282C); EARS2: c.319C>T/p.(R107C), c.1283delC/p.(P428Lfs*); ECHS1: c.161G>A/p.(R54His); c.202G>A/p.(E68Lys); NDUFAF6: c.479delA/p.(N162Ifs*27); and OXCT1: c.1370C>T/p.(T457I), c.1173-139G>T/p.(?). Conclusion: Bi-genomic DNA sequencing clarified genetic etiology in 67% (16/24) of the families. Diagnostic utility by mtDNA sequencing in 13% (3/24) and exome sequencing in 54% (13/24) of the families prioritized searching for nuclear genome pathologies for the first-tier test. Weakness and muscle wasting observed in 17% (4/24) of the families underlined that limb-girdle muscular dystrophy, similar to mitochondrial myopathy, is an essential point for differential diagnosis. The correct diagnosis is crucial for comprehensive genetic counseling of families. Also, it contributes to making treatment-helpful referrals, such as ensuring early access to medication for patients with mutations in the TK2 gene.
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Affiliation(s)
- Asuman Gedikbasi
- Department of Pediatric Basic Sciences, Institute of Child Health Istanbul University, Istanbul, Türkiye
- Division of Pediatric Nutrition and Metabolism, Department of Pediatrics, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Türkiye
| | - Guven Toksoy
- Department of Medical Genetics, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Türkiye
| | - Meryem Karaca
- Division of Pediatric Nutrition and Metabolism, Department of Pediatrics, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Türkiye
| | - Cagri Gulec
- Department of Medical Genetics, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Türkiye
| | - Mehmet Cihan Balci
- Division of Pediatric Nutrition and Metabolism, Department of Pediatrics, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Türkiye
| | - Dilek Gunes
- Division of Pediatric Nutrition and Metabolism, Department of Pediatrics, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Türkiye
| | - Seda Gunes
- Division of Pediatric Nutrition and Metabolism, Department of Pediatrics, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Türkiye
| | - Ayca Dilruba Aslanger
- Department of Medical Genetics, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Türkiye
| | - Gokcen Unverengil
- Department of Pathology, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Türkiye
| | - Birsen Karaman
- Department of Pediatric Basic Sciences, Institute of Child Health Istanbul University, Istanbul, Türkiye
- Department of Medical Genetics, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Türkiye
| | - Seher Basaran
- Department of Medical Genetics, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Türkiye
| | - Mubeccel Demirkol
- Division of Pediatric Nutrition and Metabolism, Department of Pediatrics, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Türkiye
| | - Gulden Fatma Gokcay
- Division of Pediatric Nutrition and Metabolism, Department of Pediatrics, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Türkiye
| | - Zehra Oya Uyguner
- Department of Medical Genetics, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Türkiye
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Nurchis MC, Altamura G, Riccardi MT, Radio FC, Chillemi G, Bertini ES, Garlasco J, Tartaglia M, Dallapiccola B, Damiani G. Whole genome sequencing diagnostic yield for paediatric patients with suspected genetic disorders: systematic review, meta-analysis, and GRADE assessment. Arch Public Health 2023; 81:93. [PMID: 37231492 DOI: 10.1186/s13690-023-01112-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2022] [Accepted: 05/18/2023] [Indexed: 05/27/2023] Open
Abstract
BACKGROUND About 80% of the roughly 7,000 known rare diseases are single gene disorders, about 85% of which are ultra-rare, affecting less than one in one million individuals. NGS technologies, in particular whole genome sequencing (WGS) in paediatric patients suffering from severe disorders of likely genetic origin improve the diagnostic yield allowing targeted, effective care and management. The aim of this study is to perform a systematic review and meta-analysis to assess the effectiveness of WGS, with respect to whole exome sequencing (WES) and/or usual care, for the diagnosis of suspected genetic disorders among the paediatric population. METHODS A systematic review of the literature was conducted querying relevant electronic databases, including MEDLINE, EMBASE, ISI Web of Science, and Scopus from January 2010 to June 2022. A random-effect meta-analysis was run to inspect the diagnostic yield of different techniques. A network meta-analysis was also performed to directly assess the comparison between WGS and WES. RESULTS Of the 4,927 initially retrieved articles, thirty-nine met the inclusion criteria. Overall results highlighted a significantly higher pooled diagnostic yield for WGS, 38.6% (95% CI: [32.6 - 45.0]), in respect to WES, 37.8% (95% CI: [32.9 - 42.9]) and usual care, 7.8% (95% CI: [4.4 - 13.2]). The meta-regression output suggested a higher diagnostic yield of the WGS compared to WES after controlling for the type of disease (monogenic vs non-monogenic), with a tendency to better diagnostic performances for Mendelian diseases. The network meta-analysis showed a higher diagnostic yield for WGS compared to WES (OR = 1.54, 95%CI: [1.11 - 2.12]). CONCLUSIONS Although whole genome sequencing for the paediatric population with suspected genetic disorders provided an accurate and early genetic diagnosis in a high proportion of cases, further research is needed for evaluating costs, effectiveness, and cost-effectiveness of WGS and achieving an informed decision-making process. TRIAL REGISTRATION This systematic review has not been registered.
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Grants
- RF-2018-12,366,391, 2018 Ministero della Salute
- RF-2018-12,366,391, 2018 Ministero della Salute
- RF-2018-12,366,391, 2018 Ministero della Salute
- RF-2018-12,366,391, 2018 Ministero della Salute
- RF-2018-12,366,391, 2018 Ministero della Salute
- RF-2018-12,366,391, 2018 Ministero della Salute
- RF-2018-12,366,391, 2018 Ministero della Salute
- RF-2018-12,366,391, 2018 Ministero della Salute
- RF-2018-12,366,391, 2018 Ministero della Salute
- RF-2018-12,366,391, 2018 Ministero della Salute
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Affiliation(s)
- Mario Cesare Nurchis
- Department of Woman and Child Health and Public Health, Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168, Rome, Italy
- School of Economics, Università Cattolica del Sacro Cuore, 00168, Rome, Italy
| | - Gerardo Altamura
- Department of Health Sciences and Public Health, Section of Hygiene, Università Cattolica del Sacro Cuore, Largo Francesco Vito 1, 00168, Rome, Italy.
| | - Maria Teresa Riccardi
- Department of Health Sciences and Public Health, Section of Hygiene, Università Cattolica del Sacro Cuore, Largo Francesco Vito 1, 00168, Rome, Italy
| | - Francesca Clementina Radio
- Genetics and Rare Diseases Research Division, Ospedale Pediatrico Bambino Gesù IRCCS, 00146, Rome, Italy
| | - Giovanni Chillemi
- Department for Innovation in Biological Agro-Food and Forest Systems (DIBAF), University of Tuscia, 01100, Viterbo, Italy
- Institute of Biomembranes, Bioenergetics and Molecular Biotechnologies, Centro Nazionale Delle Ricerche, 70126, Bari, Italy
| | - Enrico Silvio Bertini
- Genetics and Rare Diseases Research Division, Ospedale Pediatrico Bambino Gesù IRCCS, 00146, Rome, Italy
| | - Jacopo Garlasco
- Department of Public Health Sciences and Paediatrics, University of Turin, 10126, Turin, Italy
| | - Marco Tartaglia
- Genetics and Rare Diseases Research Division, Ospedale Pediatrico Bambino Gesù IRCCS, 00146, Rome, Italy
| | - Bruno Dallapiccola
- Genetics and Rare Diseases Research Division, Ospedale Pediatrico Bambino Gesù IRCCS, 00146, Rome, Italy
| | - Gianfranco Damiani
- Department of Woman and Child Health and Public Health, Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168, Rome, Italy
- Department of Health Sciences and Public Health, Section of Hygiene, Università Cattolica del Sacro Cuore, Largo Francesco Vito 1, 00168, Rome, Italy
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Salman DO, Mahfouz R, Bitar ER, Samaha J, Karam PE. Challenges of genetic diagnosis of inborn errors of metabolism in a major tertiary care center in Lebanon. Front Genet 2022; 13:1029947. [PMID: 36468010 PMCID: PMC9715967 DOI: 10.3389/fgene.2022.1029947] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2022] [Accepted: 11/08/2022] [Indexed: 01/25/2023] Open
Abstract
Background: Inborn errors of metabolism are rare genetic disorders; however, these are prevalent in countries with high consanguinity rates, like Lebanon. Patients are suspected, based on a combination of clinical and biochemical features; however, the final confirmation relies on genetic testing. Using next generation sequencing, as a new genetic investigational tool, carries several challenges for the physician, the geneticist, and the families. Methods: In this retrospective study, we analyzed the clinical, biochemical, and genetic profile of inborn errors of metabolism suspected patients, seen at a major tertiary care center in Lebanon, between 2015 and 2018. Genetic testing was performed using next generation sequencing. Genotype-phenotype correlation and diagnostic yield of each testing modality were studied. Results: Out of 211 patients genetically tested, 126 were suspected to have an inborn error of metabolism. The diagnostic yield of next generation sequencing reached 64.3%. Single gene testing was requested in 53%, whole exome sequencing in 36% and gene panels in 10%. Aminoacid disorders were mostly diagnosed followed by storage disorders, organic acidemias and mitochondrial diseases. Targeted testing was performed in 77% of aminoacid and organic acid disorders and half of suspected storage disorders. Single gene sequencing was positive in 75%, whereas whole exome sequencing diagnostic yield for complex cases, like mitochondrial disorders, reached 49%. Good clinical and biochemical correlation allowed the interpretation of variants of unknown significance and negative mutations as well as therapeutic management of most patients. Conclusion: Tailoring the choice of test modality, by next generation sequencing, to the category of suspected inborn errors of metabolism may lead to rapid diagnosis, shortcutting the cost of repeated testing. Whole exome sequencing as a first-tier investigation may be considered mainly for suspected mitochondrial diseases, whereas targeted sequencing can be offered upon suspicion of a specific enzyme deficiency. Timing and modality of gene test remain challenging, in view of the cost incurred by families.
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Affiliation(s)
- Doaa O. Salman
- Department of Pediatrics and Adolescent Medicine, American University of Beirut, Beirut, Lebanon
| | - Rami Mahfouz
- Department of Pathology and Laboratory Medicine, Faculty of Medicine, American University of Beirut, Beirut, Lebanon
| | - Elio R. Bitar
- Faculty of Medicine, American University of Beirut, Beirut, Lebanon
| | - Jinane Samaha
- Department of Pediatrics and Adolescent Medicine, American University of Beirut, Beirut, Lebanon,Inherited Metabolic Diseases Program, American University of Beirut Medical Center, Beirut, Lebanon
| | - Pascale E. Karam
- Department of Pediatrics and Adolescent Medicine, American University of Beirut, Beirut, Lebanon,Inherited Metabolic Diseases Program, American University of Beirut Medical Center, Beirut, Lebanon,*Correspondence: Pascale E. Karam,
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5
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Vogel GF, Mozer-Glassberg Y, Landau YE, Schlieben LD, Prokisch H, Feichtinger RG, Mayr JA, Brennenstuhl H, Schröter J, Pechlaner A, Alkuraya FS, Baker JJ, Barcia G, Baric I, Braverman N, Burnyte B, Christodoulou J, Ciara E, Coman D, Das AM, Darin N, Della Marina A, Distelmaier F, Eklund EA, Ersoy M, Fang W, Gaignard P, Ganetzky RD, Gonzales E, Howard C, Hughes J, Konstantopoulou V, Kose M, Kerr M, Khan A, Lenz D, McFarland R, Margolis MG, Morrison K, Müller T, Murayama K, Nicastro E, Pennisi A, Peters H, Piekutowska-Abramczuk D, Rötig A, Santer R, Scaglia F, Schiff M, Shagrani M, Sharrard M, Soler-Alfonso C, Staufner C, Storey I, Stormon M, Taylor RW, Thorburn DR, Teles EL, Wang JS, Weghuber D, Wortmann S. Genotypic and phenotypic spectrum of infantile liver failure due to pathogenic TRMU variants. Genet Med 2022:S1098-3600(22)00953-4. [DOI: 10.1016/j.gim.2022.09.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 09/27/2022] [Accepted: 09/28/2022] [Indexed: 11/06/2022] Open
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Bölsterli BK, Boltshauser E, Palmieri L, Spenger J, Brunner-krainz M, Distelmaier F, Freisinger P, Geis T, Gropman AL, Häberle J, Hentschel J, Jeandidier B, Karall D, Keren B, Klabunde-cherwon A, Konstantopoulou V, Kottke R, Lasorsa FM, Makowski C, Mignot C, O’gorman Tuura R, Porcelli V, Santer R, Sen K, Steinbrücker K, Syrbe S, Wagner M, Ziegler A, Zöggeler T, Mayr JA, Prokisch H, Wortmann SB. Ketogenic Diet Treatment of Defects in the Mitochondrial Malate Aspartate Shuttle and Pyruvate Carrier. Nutrients 2022; 14:3605. [PMID: 36079864 PMCID: PMC9460686 DOI: 10.3390/nu14173605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 08/10/2022] [Accepted: 08/15/2022] [Indexed: 11/17/2022] Open
Abstract
The mitochondrial malate aspartate shuttle system (MAS) maintains the cytosolic NAD+/NADH redox balance, thereby sustaining cytosolic redox-dependent pathways, such as glycolysis and serine biosynthesis. Human disease has been associated with defects in four MAS-proteins (encoded by MDH1, MDH2, GOT2, SLC25A12) sharing a neurological/epileptic phenotype, as well as citrin deficiency (SLC25A13) with a complex hepatopathic-neuropsychiatric phenotype. Ketogenic diets (KD) are high-fat/low-carbohydrate diets, which decrease glycolysis thus bypassing the mentioned defects. The same holds for mitochondrial pyruvate carrier (MPC) 1 deficiency, which also presents neurological deficits. We here describe 40 (18 previously unreported) subjects with MAS-/MPC1-defects (32 neurological phenotypes, eight citrin deficiency), describe and discuss their phenotypes and genotypes (presenting 12 novel variants), and the efficacy of KD. Of 13 MAS/MPC1-individuals with a neurological phenotype treated with KD, 11 experienced benefits—mainly a striking effect against seizures. Two individuals with citrin deficiency deceased before the correct diagnosis was established, presumably due to high-carbohydrate treatment. Six citrin-deficient individuals received a carbohydrate-restricted/fat-enriched diet and showed normalisation of laboratory values/hepatopathy as well as age-adequate thriving. We conclude that patients with MAS-/MPC1-defects are amenable to dietary intervention and that early (genetic) diagnosis is key for initiation of proper treatment and can even be lifesaving.
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Pardo B, Herrada-Soler E, Satrústegui J, Contreras L, del Arco A. AGC1 Deficiency: Pathology and Molecular and Cellular Mechanisms of the Disease. Int J Mol Sci 2022; 23:528. [PMID: 35008954 PMCID: PMC8745132 DOI: 10.3390/ijms23010528] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 12/23/2021] [Accepted: 12/24/2021] [Indexed: 02/01/2023] Open
Abstract
AGC1/Aralar/Slc25a12 is the mitochondrial carrier of aspartate-glutamate, the regulatory component of the NADH malate-aspartate shuttle (MAS) that transfers cytosolic redox power to neuronal mitochondria. The deficiency in AGC1/Aralar leads to the human rare disease named "early infantile epileptic encephalopathy 39" (EIEE 39, OMIM # 612949) characterized by epilepsy, hypotonia, arrested psychomotor neurodevelopment, hypo myelination and a drastic drop in brain aspartate (Asp) and N-acetylaspartate (NAA). Current evidence suggest that neurons are the main brain cell type expressing Aralar. However, paradoxically, glial functions such as myelin and Glutamine (Gln) synthesis are markedly impaired in AGC1 deficiency. Herein, we discuss the role of the AGC1/Aralar-MAS pathway in neuronal functions such as Asp and NAA synthesis, lactate use, respiration on glucose, glutamate (Glu) oxidation and other neurometabolic aspects. The possible mechanism triggering the pathophysiological findings in AGC1 deficiency, such as epilepsy and postnatal hypomyelination observed in humans and mice, are also included. Many of these mechanisms arise from findings in the aralar-KO mice model that extensively recapitulate the human disease including the astroglial failure to synthesize Gln and the dopamine (DA) mishandling in the nigrostriatal system. Epilepsy and DA mishandling are a direct consequence of the metabolic defect in neurons due to AGC1/Aralar deficiency. However, the deficits in myelin and Gln synthesis may be a consequence of neuronal affectation or a direct effect of AGC1/Aralar deficiency in glial cells. Further research is needed to clarify this question and delineate the transcellular metabolic fluxes that control brain functions. Finally, we discuss therapeutic approaches successfully used in AGC1-deficient patients and mice.
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Affiliation(s)
- Beatriz Pardo
- Departamento de Biología Molecular, Universidad Autónoma de Madrid, 28049 Madrid, Spain; (E.H.-S.); (J.S.); (L.C.)
- Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid (UAM)-Consejo Superior de Investigaciones Científicas (CSIC), 28049 Madrid, Spain;
- Instituto de Investigaciones Sanitarias Fundación Jiménez Díaz (IIS-FJD), Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Eduardo Herrada-Soler
- Departamento de Biología Molecular, Universidad Autónoma de Madrid, 28049 Madrid, Spain; (E.H.-S.); (J.S.); (L.C.)
- Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid (UAM)-Consejo Superior de Investigaciones Científicas (CSIC), 28049 Madrid, Spain;
- Instituto de Investigaciones Sanitarias Fundación Jiménez Díaz (IIS-FJD), Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Jorgina Satrústegui
- Departamento de Biología Molecular, Universidad Autónoma de Madrid, 28049 Madrid, Spain; (E.H.-S.); (J.S.); (L.C.)
- Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid (UAM)-Consejo Superior de Investigaciones Científicas (CSIC), 28049 Madrid, Spain;
- Instituto de Investigaciones Sanitarias Fundación Jiménez Díaz (IIS-FJD), Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Laura Contreras
- Departamento de Biología Molecular, Universidad Autónoma de Madrid, 28049 Madrid, Spain; (E.H.-S.); (J.S.); (L.C.)
- Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid (UAM)-Consejo Superior de Investigaciones Científicas (CSIC), 28049 Madrid, Spain;
- Instituto de Investigaciones Sanitarias Fundación Jiménez Díaz (IIS-FJD), Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Araceli del Arco
- Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid (UAM)-Consejo Superior de Investigaciones Científicas (CSIC), 28049 Madrid, Spain;
- Instituto de Investigaciones Sanitarias Fundación Jiménez Díaz (IIS-FJD), Universidad Autónoma de Madrid, 28049 Madrid, Spain
- Centro Regional de Investigaciones Biomédicas, Facultad de Ciencias Ambientales y Bioquímica, Universidad de Castilla La Mancha, 45071 Toledo, Spain
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Luo Q, Wen X, Zhou J, Chen Y, Lv Z, Shen X, Liu J. A novel compound heterozygous mutation of the MTO1 gene associated with complex oxidative phosphorylation deficiency type 10. Clin Chim Acta 2021; 523:172-177. [PMID: 34547275 DOI: 10.1016/j.cca.2021.09.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 09/08/2021] [Accepted: 09/15/2021] [Indexed: 10/20/2022]
Abstract
BACKGROUND The mitochondrial tRNA translation optimization 1 (MTO1) gene, which is closely related to defective mitochondrial oxidative phosphorylation, is an evolutionarily conserved protein expressed in high energy-demanding tissues and is associated with complex oxidative phosphorylation deficiency type 10 (COXPD10) in humans. Related cases and studies are still scarce and have not been reported in the Chinese region. MATERIALS AND METHODS Detailed clinical assessment was applied to the patient. Based on next-generation sequencing technology, we performed whole-exome sequencing of the patient and the parents. Sanger sequencing was used for validation. Bioinformatics software and protein simulations were used to predict the pathogenicity of the variants. RESULTS The patient was diagnosed with a possible association with mitochondrial disease according to the clinical manifestations and physical examination. A novel frameshift mutation c.344delA (p. Asn115Thrfs*11) and a novel point mutation c.1055C > T (p. Thr352Met) in the MTO1 gene were identified. They were found to cause abnormal changes in amino acids and the protein by biochemical tools, indicating it may be pathogenic. CONCLUSION We present two novel and possibly pathogenic variants in the MTO1 gene in a Chinese Han family.
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Affiliation(s)
- Qing Luo
- Department of Laboratory Medicine, Affiliated Hospital of Southwest Medical University, 25 Taiping Street, Luzhou, Sichuan 646000, China
| | - Xia Wen
- Department of Laboratory Medicine, Affiliated Hospital of Southwest Medical University, 25 Taiping Street, Luzhou, Sichuan 646000, China
| | - Jiahong Zhou
- Department of Laboratory Medicine, Affiliated Hospital of Southwest Medical University, 25 Taiping Street, Luzhou, Sichuan 646000, China
| | - Yang Chen
- Department of Laboratory Medicine, Affiliated Hospital of Southwest Medical University, 25 Taiping Street, Luzhou, Sichuan 646000, China
| | - Zhiyu Lv
- Department of Neurology, Affiliated Hospital of Southwest Medical University, 25 Taiping Street, Luzhou, Sichuan 646000, China
| | - Xing Shen
- Pediatric Intensive Care Unit, Affiliated Hospital of Southwest Medical University, 25 Taiping Street, Luzhou, Sichuan 646000, China
| | - Jinbo Liu
- Department of Laboratory Medicine, Affiliated Hospital of Southwest Medical University, 25 Taiping Street, Luzhou, Sichuan 646000, China.
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