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Gouiza I, Hechmi M, Zioudi A, Dallali H, Kheriji N, Charif M, Le Mao M, Galai S, Kraoua L, Ben Youssef-Turki I, Kraoua I, Lenaers G, Kefi R. Expanding the genetic spectrum of mitochondrial diseases in Tunisia: novel variants revealed by whole-exome sequencing. Front Genet 2024; 14:1259826. [PMID: 38283147 PMCID: PMC10811255 DOI: 10.3389/fgene.2023.1259826] [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: 07/16/2023] [Accepted: 12/22/2023] [Indexed: 01/30/2024] Open
Abstract
Introduction: Inherited mitochondrial diseases are the most common group of metabolic disorders caused by a defect in oxidative phosphorylation. They are characterized by a wide clinical and genetic spectrum and can manifest at any age. In this study, we established novel phenotype-genotype correlations between the clinical and molecular features of a cohort of Tunisian patients with mitochondrial diseases. Materials and methods: Whole-exome sequencing was performed on five Tunisian patients with suspected mitochondrial diseases. Then, a combination of filtering and bioinformatics prediction tools was utilized to assess the pathogenicity of genetic variations. Sanger sequencing was subsequently performed to confirm the presence of potential deleterious variants in the patients and verify their segregation within families. Structural modeling was conducted to study the effect of novel variants on the protein structure. Results: We identified two novel homozygous variants in NDUFAF5 (c.827G>C; p.Arg276Pro) and FASTKD2 (c.496_497del; p.Leu166GlufsTer2) associated with a severe clinical form of Leigh and Leigh-like syndromes, respectively. Our results further disclosed two variants unreported in North Africa, in GFM2 (c.569G>A; p.Arg190Gln) and FOXRED1 (c.1261G>A; p.Val421Met) genes, and we described the first case of fumaric aciduria in a Tunisian patient harboring the c.1358T>C; p.Leu453Pro FH variant. Conclusion: Our study expands the mutational and phenotypic spectrum of mitochondrial diseases in Tunisia and highlights the importance of next-generation sequencing to decipher the pathomolecular mechanisms responsible for these disorders in an admixed population.
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Affiliation(s)
- Ismail Gouiza
- University of Angers, MitoLab Team, Unité MitoVasc, UMR CNRS (Unité mixte de recherche Centre national de la recherche scientifique) 6015 INSERM (Institut national de la santé et de la recherche médicale) U1083, SFR ICAT, University of Angers, Angers, France
- Laboratory of Biomedical Genomics and Oncogenetics, Institut Pasteur de Tunis, Tunis, Tunisia
- Tunis El Manar University, Tunis, Tunisia
- Faculty of Medicine of Tunis, Tunis, Tunisia
| | - Meriem Hechmi
- Laboratory of Biomedical Genomics and Oncogenetics, Institut Pasteur de Tunis, Tunis, Tunisia
- Tunis El Manar University, Tunis, Tunisia
| | - Abir Zioudi
- Tunis El Manar University, Tunis, Tunisia
- Faculty of Medicine of Tunis, Tunis, Tunisia
- Research Laboratory LR18SP04, Department of Child and Adolescent Neurology, National Institute Mongi Ben Hmida of Neurology, Tunis, Tunisia
| | - Hamza Dallali
- Laboratory of Biomedical Genomics and Oncogenetics, Institut Pasteur de Tunis, Tunis, Tunisia
- Tunis El Manar University, Tunis, Tunisia
| | - Nadia Kheriji
- Laboratory of Biomedical Genomics and Oncogenetics, Institut Pasteur de Tunis, Tunis, Tunisia
- Tunis El Manar University, Tunis, Tunisia
- Faculty of Medicine of Tunis, Tunis, Tunisia
| | - Majida Charif
- Genetics and Immuno-Cell Therapy Team, Mohammed First University, Oujda, Morocco
| | - Morgane Le Mao
- University of Angers, MitoLab Team, Unité MitoVasc, UMR CNRS (Unité mixte de recherche Centre national de la recherche scientifique) 6015 INSERM (Institut national de la santé et de la recherche médicale) U1083, SFR ICAT, University of Angers, Angers, France
| | - Said Galai
- Faculty of Medicine of Tunis, Tunis, Tunisia
- Department of Clinical Biology, National Institute Mongi Ben Hmida of Neurology, Tunis, Tunisia
| | - Lilia Kraoua
- Tunis El Manar University, Tunis, Tunisia
- Department of Congenital and Hereditary Diseases, Charles Nicolle Hospital, Tunis, Tunisia
| | - Ilhem Ben Youssef-Turki
- Tunis El Manar University, Tunis, Tunisia
- Faculty of Medicine of Tunis, Tunis, Tunisia
- Research Laboratory LR18SP04, Department of Child and Adolescent Neurology, National Institute Mongi Ben Hmida of Neurology, Tunis, Tunisia
| | - Ichraf Kraoua
- Tunis El Manar University, Tunis, Tunisia
- Faculty of Medicine of Tunis, Tunis, Tunisia
- Research Laboratory LR18SP04, Department of Child and Adolescent Neurology, National Institute Mongi Ben Hmida of Neurology, Tunis, Tunisia
| | - Guy Lenaers
- University of Angers, MitoLab Team, Unité MitoVasc, UMR CNRS (Unité mixte de recherche Centre national de la recherche scientifique) 6015 INSERM (Institut national de la santé et de la recherche médicale) U1083, SFR ICAT, University of Angers, Angers, France
- Department of Neurology, CHU d’Angers, Angers, France
| | - Rym Kefi
- Laboratory of Biomedical Genomics and Oncogenetics, Institut Pasteur de Tunis, Tunis, Tunisia
- Tunis El Manar University, Tunis, Tunisia
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Marumo T, Maduka CV, Ural E, Apu EH, Chung SJ, Tanabe K, van den Berg NS, Zhou Q, Martin BA, Miura T, Rosenthal EL, Shibahara T, Contag CH. Flavinated SDHA underlies the change in intrinsic optical properties of oral cancers. Commun Biol 2023; 6:1134. [PMID: 37945749 PMCID: PMC10636189 DOI: 10.1038/s42003-023-05510-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Accepted: 10/26/2023] [Indexed: 11/12/2023] Open
Abstract
The molecular basis of reduced autofluorescence in oral squamous cell carcinoma (OSCC) cells relative to normal cells has been speculated to be due to lower levels of free flavin adenine dinucleotide (FAD). This speculation, along with differences in the intrinsic optical properties of extracellular collagen, lies at the foundation of the design of currently-used clinical optical detection devices. Here, we report that free FAD levels may not account for differences in autofluorescence of OSCC cells, but that the differences relate to FAD as a co-factor for flavination. Autofluorescence from a 70 kDa flavoprotein, succinate dehydrogenase A (SDHA), was found to be responsible for changes in optical properties within the FAD spectral region, with lower levels of flavinated SDHA in OSCC cells. Since flavinated SDHA is required for functional complexation with succinate dehydrogenase B (SDHB), decreased SDHB levels were observed in human OSCC tissue relative to normal tissues. Accordingly, the metabolism of OSCC cells was found to be significantly altered relative to normal cells, revealing vulnerabilities for both diagnosis and targeted therapy. Optimizing non-invasive tools based on optical and metabolic signatures of cancers will enable more precise and early diagnosis leading to improved outcomes in patients.
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Affiliation(s)
- Tomoko Marumo
- Department of Oral and Maxillofacial Surgery, Tokyo Dental College, 2-9-18 Kanda-Misakicho, Chiyoda-ku, Tokyo, 101-0061, Japan
- Department of Biomedical Engineering, Michigan State University, East Lansing, MI, 48824, USA
- Institute for Quantitative Health Science & Engineering, Michigan State University, East Lansing, MI, 48824, USA
| | - Chima V Maduka
- Department of Biomedical Engineering, Michigan State University, East Lansing, MI, 48824, USA
- Institute for Quantitative Health Science & Engineering, Michigan State University, East Lansing, MI, 48824, USA
- Comparative Medicine & Integrative Biology, Michigan State University, East Lansing, MI, 48824, USA
- BioFrontiers Institute, University of Colorado, Boulder, CO, 80303, USA
| | - Evran Ural
- Department of Biomedical Engineering, Michigan State University, East Lansing, MI, 48824, USA
- Institute for Quantitative Health Science & Engineering, Michigan State University, East Lansing, MI, 48824, USA
| | - Ehsanul Hoque Apu
- Department of Biomedical Engineering, Michigan State University, East Lansing, MI, 48824, USA
- Institute for Quantitative Health Science & Engineering, Michigan State University, East Lansing, MI, 48824, USA
- Division of Hematology and Oncology, Department of Internal Medicine, Michigan Medicine, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Seock-Jin Chung
- Department of Biomedical Engineering, Michigan State University, East Lansing, MI, 48824, USA
- Institute for Quantitative Health Science & Engineering, Michigan State University, East Lansing, MI, 48824, USA
| | - Koji Tanabe
- Department of Biomedical Engineering, Iwate Medical University, 1-1-1 Idaidori, Yahaba-cho, Shiwa-gun, Iwate, 028-3694, Japan
| | - Nynke S van den Berg
- Department of Otolaryngology - Division of Head and Neck Surgery, Stanford University School of Medicine, 269 Campus Drive, Stanford, CA, 94305, USA
| | - Quan Zhou
- Department of Otolaryngology - Division of Head and Neck Surgery, Stanford University School of Medicine, 269 Campus Drive, Stanford, CA, 94305, USA
| | - Brock A Martin
- Department of Pathology, Stanford University School of Medicine, 3100 Pasteur Drive, Stanford, CA, 94305, USA
| | - Tadashi Miura
- Oral Health Science Center, Tokyo Dental College, 2-1-14 Kanda-Misakicho, Chiyoda-ku, Tokyo, 101-0061, Japan
| | - Eben L Rosenthal
- Department of Otolaryngology - Division of Head and Neck Surgery, Stanford University School of Medicine, 269 Campus Drive, Stanford, CA, 94305, USA
- Department of Otolaryngology - Head and Neck Surgery, Vanderbilt University Medical Center, 1211 Medical Center Dr, Nashville, TN, 37232, USA
| | - Takahiko Shibahara
- Department of Oral and Maxillofacial Surgery, Tokyo Dental College, 2-9-18 Kanda-Misakicho, Chiyoda-ku, Tokyo, 101-0061, Japan
| | - Christopher H Contag
- Department of Biomedical Engineering, Michigan State University, East Lansing, MI, 48824, USA.
- Institute for Quantitative Health Science & Engineering, Michigan State University, East Lansing, MI, 48824, USA.
- Department of Microbiology & Molecular Genetics, Michigan State University, East Lansing, MI, 48824, USA.
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Tian Q, Wang G, Ma X, Shen Q, Ding M, Yang X, Luo X, Li R, Wang Z, Wang X, Fu Z, Yang Q, Tang J, Wang G. Riboflavin integrates cellular energetics and cell cycle to regulate maize seed development. PLANT BIOTECHNOLOGY JOURNAL 2022; 20:1487-1501. [PMID: 35426230 PMCID: PMC9342611 DOI: 10.1111/pbi.13826] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2022] [Accepted: 04/10/2022] [Indexed: 05/23/2023]
Abstract
Riboflavin is the precursor of essential cofactors for diverse metabolic processes. Unlike animals, plants can de novo produce riboflavin through an ancestrally conserved pathway, like bacteria and fungi. However, the mechanism by which riboflavin regulates seed development is poorly understood. Here, we report a novel maize (Zea mays L.) opaque mutant o18, which displays an increase in lysine accumulation, but impaired endosperm filling and embryo development. O18 encodes a rate-limiting bifunctional enzyme ZmRIBA1, targeted to plastid where to initiate riboflavin biosynthesis. Loss of function of O18 specifically disrupts respiratory complexes I and II, but also decreases SDH1 flavinylation, and in turn shifts the mitochondrial tricarboxylic acid (TCA) cycle to glycolysis. The deprivation of cellular energy leads to cell-cycle arrest at G1 and S phases in both mitosis and endoreduplication during endosperm development. The unexpected up-regulation of cell-cycle genes in o18 correlates with the increase of H3K4me3 levels, revealing a possible H3K4me-mediated epigenetic back-up mechanism for cell-cycle progression under unfavourable circumstances. Overexpression of O18 increases riboflavin production and confers osmotic tolerance. Altogether, our results substantiate a key role of riboflavin in coordinating cellular energy and cell cycle to modulate maize endosperm development.
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Affiliation(s)
- Qiuzhen Tian
- National Key Laboratory of Wheat and Maize Crops ScienceCIMMYT‐Henan Joint Center for Wheat and Maize ImprovementCollaborative Innovation Center of Henan Grain CropsCollege of AgronomyHenan Agricultural UniversityZhengzhouChina
| | - Gang Wang
- School of Agriculture and BiologyShanghai Jiao Tong UniversityShanghaiChina
| | - Xuexia Ma
- Shanghai Key Laboratory of Bio‐Energy CropsSchool of Life SciencesShanghai UniversityShanghaiChina
| | - Qingwen Shen
- National Key Laboratory of Wheat and Maize Crops ScienceCIMMYT‐Henan Joint Center for Wheat and Maize ImprovementCollaborative Innovation Center of Henan Grain CropsCollege of AgronomyHenan Agricultural UniversityZhengzhouChina
| | - Mengli Ding
- National Key Laboratory of Wheat and Maize Crops ScienceCIMMYT‐Henan Joint Center for Wheat and Maize ImprovementCollaborative Innovation Center of Henan Grain CropsCollege of AgronomyHenan Agricultural UniversityZhengzhouChina
| | - Xueyi Yang
- National Key Laboratory of Wheat and Maize Crops ScienceCIMMYT‐Henan Joint Center for Wheat and Maize ImprovementCollaborative Innovation Center of Henan Grain CropsCollege of AgronomyHenan Agricultural UniversityZhengzhouChina
| | - Xiaoli Luo
- National Key Laboratory of Wheat and Maize Crops ScienceCIMMYT‐Henan Joint Center for Wheat and Maize ImprovementCollaborative Innovation Center of Henan Grain CropsCollege of AgronomyHenan Agricultural UniversityZhengzhouChina
| | - Rongrong Li
- National Key Laboratory of Wheat and Maize Crops ScienceCIMMYT‐Henan Joint Center for Wheat and Maize ImprovementCollaborative Innovation Center of Henan Grain CropsCollege of AgronomyHenan Agricultural UniversityZhengzhouChina
| | - Zhenghui Wang
- National Key Laboratory of Wheat and Maize Crops ScienceCIMMYT‐Henan Joint Center for Wheat and Maize ImprovementCollaborative Innovation Center of Henan Grain CropsCollege of AgronomyHenan Agricultural UniversityZhengzhouChina
| | - Xiangyang Wang
- National Key Laboratory of Wheat and Maize Crops ScienceCIMMYT‐Henan Joint Center for Wheat and Maize ImprovementCollaborative Innovation Center of Henan Grain CropsCollege of AgronomyHenan Agricultural UniversityZhengzhouChina
| | - Zhiyuan Fu
- National Key Laboratory of Wheat and Maize Crops ScienceCIMMYT‐Henan Joint Center for Wheat and Maize ImprovementCollaborative Innovation Center of Henan Grain CropsCollege of AgronomyHenan Agricultural UniversityZhengzhouChina
| | - Qinghua Yang
- National Key Laboratory of Wheat and Maize Crops ScienceCIMMYT‐Henan Joint Center for Wheat and Maize ImprovementCollaborative Innovation Center of Henan Grain CropsCollege of AgronomyHenan Agricultural UniversityZhengzhouChina
| | - Jihua Tang
- National Key Laboratory of Wheat and Maize Crops ScienceCIMMYT‐Henan Joint Center for Wheat and Maize ImprovementCollaborative Innovation Center of Henan Grain CropsCollege of AgronomyHenan Agricultural UniversityZhengzhouChina
- The Shennong LaboratoryZhengzhouChina
| | - Guifeng Wang
- National Key Laboratory of Wheat and Maize Crops ScienceCIMMYT‐Henan Joint Center for Wheat and Maize ImprovementCollaborative Innovation Center of Henan Grain CropsCollege of AgronomyHenan Agricultural UniversityZhengzhouChina
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4
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Bakare AB, Lesnefsky EJ, Iyer S. Leigh Syndrome: A Tale of Two Genomes. Front Physiol 2021; 12:693734. [PMID: 34456746 PMCID: PMC8385445 DOI: 10.3389/fphys.2021.693734] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2021] [Accepted: 07/22/2021] [Indexed: 12/21/2022] Open
Abstract
Leigh syndrome is a rare, complex, and incurable early onset (typically infant or early childhood) mitochondrial disorder with both phenotypic and genetic heterogeneity. The heterogeneous nature of this disorder, based in part on the complexity of mitochondrial genetics, and the significant interactions between the nuclear and mitochondrial genomes has made it particularly challenging to research and develop therapies. This review article discusses some of the advances that have been made in the field to date. While the prognosis is poor with no current substantial treatment options, multiple studies are underway to understand the etiology, pathogenesis, and pathophysiology of Leigh syndrome. With advances in available research tools leading to a better understanding of the mitochondria in health and disease, there is hope for novel treatment options in the future.
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Affiliation(s)
- Ajibola B. Bakare
- Department of Biological Sciences, J. William Fulbright College of Arts and Sciences, University of Arkansas, Fayetteville, AR, United States
| | - Edward J. Lesnefsky
- Division of Cardiology, Pauley Heart Center, Department of Internal Medicine, School of Medicine, Virginia Commonwealth University, Richmond, VA, United States
- Department of Physiology/Biophysics, School of Medicine, Virginia Commonwealth University, Richmond, VA, United States
- Department of Biochemistry and Molecular Biology, School of Medicine, Virginia Commonwealth University, Richmond, VA, United States
| | - Shilpa Iyer
- Department of Biological Sciences, J. William Fulbright College of Arts and Sciences, University of Arkansas, Fayetteville, AR, United States
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Zanfardino P, Doccini S, Santorelli FM, Petruzzella V. Tackling Dysfunction of Mitochondrial Bioenergetics in the Brain. Int J Mol Sci 2021; 22:8325. [PMID: 34361091 PMCID: PMC8348117 DOI: 10.3390/ijms22158325] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 07/29/2021] [Accepted: 07/30/2021] [Indexed: 12/15/2022] Open
Abstract
Oxidative phosphorylation (OxPhos) is the basic function of mitochondria, although the landscape of mitochondrial functions is continuously growing to include more aspects of cellular homeostasis. Thanks to the application of -omics technologies to the study of the OxPhos system, novel features emerge from the cataloging of novel proteins as mitochondrial thus adding details to the mitochondrial proteome and defining novel metabolic cellular interrelations, especially in the human brain. We focussed on the diversity of bioenergetics demand and different aspects of mitochondrial structure, functions, and dysfunction in the brain. Definition such as 'mitoexome', 'mitoproteome' and 'mitointeractome' have entered the field of 'mitochondrial medicine'. In this context, we reviewed several genetic defects that hamper the last step of aerobic metabolism, mostly involving the nervous tissue as one of the most prominent energy-dependent tissues and, as consequence, as a primary target of mitochondrial dysfunction. The dual genetic origin of the OxPhos complexes is one of the reasons for the complexity of the genotype-phenotype correlation when facing human diseases associated with mitochondrial defects. Such complexity clinically manifests with extremely heterogeneous symptoms, ranging from organ-specific to multisystemic dysfunction with different clinical courses. Finally, we briefly discuss the future directions of the multi-omics study of human brain disorders.
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Affiliation(s)
- Paola Zanfardino
- Department of Medical Basic Sciences, Neurosciences and Sense Organs, University of Bari Aldo Moro, 70124 Bari, Italy;
| | - Stefano Doccini
- IRCCS Fondazione Stella Maris, Calambrone, 56128 Pisa, Italy;
| | | | - Vittoria Petruzzella
- Department of Medical Basic Sciences, Neurosciences and Sense Organs, University of Bari Aldo Moro, 70124 Bari, Italy;
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Blackout in the powerhouse: clinical phenotypes associated with defects in the assembly of OXPHOS complexes and the mitoribosome. Biochem J 2021; 477:4085-4132. [PMID: 33151299 PMCID: PMC7657662 DOI: 10.1042/bcj20190767] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 09/29/2020] [Accepted: 10/05/2020] [Indexed: 12/26/2022]
Abstract
Mitochondria produce the bulk of the energy used by almost all eukaryotic cells through oxidative phosphorylation (OXPHOS) which occurs on the four complexes of the respiratory chain and the F1–F0 ATPase. Mitochondrial diseases are a heterogenous group of conditions affecting OXPHOS, either directly through mutation of genes encoding subunits of OXPHOS complexes, or indirectly through mutations in genes encoding proteins supporting this process. These include proteins that promote assembly of the OXPHOS complexes, the post-translational modification of subunits, insertion of cofactors or indeed subunit synthesis. The latter is important for all 13 of the proteins encoded by human mitochondrial DNA, which are synthesised on mitochondrial ribosomes. Together the five OXPHOS complexes and the mitochondrial ribosome are comprised of more than 160 subunits and many more proteins support their biogenesis. Mutations in both nuclear and mitochondrial genes encoding these proteins have been reported to cause mitochondrial disease, many leading to defective complex assembly with the severity of the assembly defect reflecting the severity of the disease. This review aims to act as an interface between the clinical and basic research underpinning our knowledge of OXPHOS complex and ribosome assembly, and the dysfunction of this process in mitochondrial disease.
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Hu C, Xu Q, Shen J, Wang Y. Clinical and Genetic Characteristics of Mitochondrial Encephalopathy Due to FOXRED1 Mutations: Two Chinese Case Reports and a Review of the Literature. Front Neurol 2021; 12:633397. [PMID: 33613441 PMCID: PMC7887287 DOI: 10.3389/fneur.2021.633397] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Accepted: 01/12/2021] [Indexed: 11/30/2022] Open
Abstract
Background: As one of the assembly factors of complex I in the mitochondrial respiratory chain, FOXRED1 plays an important role in mitochondrial function. However, only a few patients with mitochondrial encephalopathy due to FOXRED1 defects have been reported. Methods: Two Chinese patients with mitochondrial encephalopathy due to mutations in FOXRED1 were identified through trio whole-exome sequencing. The clinical presentation, laboratory data, brain imaging findings, and genetic results were collected and reviewed. All previously reported cases with FOXRED1-related mitochondrial encephalopathy were collected using a PubMed search, and their data were reviewed. Results: Two patients presented with severe neurodevelopmental delay, epilepsy, high lactic acid levels, and remarkable diffuse brain atrophy and polycystic encephalomalacia during early infancy. Trio whole-exome sequencing revealed compound heterozygous variants in both patients: one case harbored a c.606_607delAG frameshift variant and a c.1054C>T (p.R352W) variant. At the same time, the other carried a novel c.352C>T (p.Q118X) variant and a reported c.1054C>T (p.R352W) variant. To date, nine patients have been reported with FOXRED1 defects, including our two cases. The most common presentations were neurodevelopment delay (100%), epilepsy (80%), poor feeding (30%), and vision loss (20%). Multisystem involvement comprised cardiovascular dysfunction (30%), abnormal liver function (20%), and hypoglycemia (10%). The neuroimaging results ranged from normal to severe cerebral atrophy and polycystic encephalomalacia in early infancy. Eleven pathogenic variants in FOXRED1 have been reported, comprising six missense variants, two non-sense variants, two frameshift variants, and one splice variant; among these the c.1054C>T (p.R352W) and c.612_615dupAGTG (p.A206SfsX15) variants are more common. Conclusion:FOXRED1-related mitochondrial disorders have high clinical and genetic heterogeneity. Our study expanded the clinical and genetic spectrum of FOXRED1 defects. Early infantile onset and progressive encephalopathy are the most common clinical presentations, while the variants c.1054C>T (p.R352W) and c.612_615dupAGTG (p.A206SfsX15) may be critical founder mutations.
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Affiliation(s)
- Chaoping Hu
- Department of Neurology, Children's Hospital of Fudan University, Shanghai, China
| | - Qiong Xu
- Department of Child Health Care, Children's Hospital of Fudan University, Shanghai, China
| | - Jin Shen
- Department of Radiology, Children's Hospital of Fudan University, Shanghai, China
| | - Yi Wang
- Department of Neurology, Children's Hospital of Fudan University, Shanghai, China
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8
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Mitochondrial Structure and Bioenergetics in Normal and Disease Conditions. Int J Mol Sci 2021; 22:ijms22020586. [PMID: 33435522 PMCID: PMC7827222 DOI: 10.3390/ijms22020586] [Citation(s) in RCA: 71] [Impact Index Per Article: 23.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 01/03/2021] [Accepted: 01/04/2021] [Indexed: 02/06/2023] Open
Abstract
Mitochondria are ubiquitous intracellular organelles found in almost all eukaryotes and involved in various aspects of cellular life, with a primary role in energy production. The interest in this organelle has grown stronger with the discovery of their link to various pathologies, including cancer, aging and neurodegenerative diseases. Indeed, dysfunctional mitochondria cannot provide the required energy to tissues with a high-energy demand, such as heart, brain and muscles, leading to a large spectrum of clinical phenotypes. Mitochondrial defects are at the origin of a group of clinically heterogeneous pathologies, called mitochondrial diseases, with an incidence of 1 in 5000 live births. Primary mitochondrial diseases are associated with genetic mutations both in nuclear and mitochondrial DNA (mtDNA), affecting genes involved in every aspect of the organelle function. As a consequence, it is difficult to find a common cause for mitochondrial diseases and, subsequently, to offer a precise clinical definition of the pathology. Moreover, the complexity of this condition makes it challenging to identify possible therapies or drug targets.
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Wang C, Richter‐Dennerlein R, Pacheu‐Grau D, Liu F, Zhu Y, Dennerlein S, Rehling P. MITRAC15/COA1 promotes mitochondrial translation in a ND2 ribosome-nascent chain complex. EMBO Rep 2020; 21:e48833. [PMID: 31721420 PMCID: PMC6945058 DOI: 10.15252/embr.201948833] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Revised: 10/28/2019] [Accepted: 10/29/2019] [Indexed: 01/12/2023] Open
Abstract
The mitochondrial genome encodes for thirteen core subunits of the oxidative phosphorylation system. These proteins assemble with imported proteins in a modular manner into stoichiometric enzyme complexes. Assembly factors assist in these biogenesis processes by providing co-factors or stabilizing transient assembly stages. However, how expression of the mitochondrial-encoded subunits is regulated to match the availability of nuclear-encoded subunits is still unresolved. Here, we address the function of MITRAC15/COA1, a protein that participates in complex I biogenesis and complex IV biogenesis. Our analyses of a MITRAC15 knockout mutant reveal that MITRAC15 is required for translation of the mitochondrial-encoded complex I subunit ND2. We find that MITRAC15 is a constituent of a ribosome-nascent chain complex during ND2 translation. Chemical crosslinking analyses demonstrate that binding of the ND2-specific assembly factor ACAD9 to the ND2 polypeptide occurs at the C-terminus and thus downstream of MITRAC15. Our analyses demonstrate that expression of the founder subunit ND2 of complex I undergoes regulation. Moreover, a ribosome-nascent chain complex with MITRAC15 is at the heart of this process.
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Affiliation(s)
- Cong Wang
- Department of Cellular BiochemistryUniversity Medical Center GöttingenGöttingenGermany
- Cluster of Excellence “Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells” (MBExC)University of GoettingenGoettingenGermany
| | - Ricarda Richter‐Dennerlein
- Department of Cellular BiochemistryUniversity Medical Center GöttingenGöttingenGermany
- Cluster of Excellence “Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells” (MBExC)University of GoettingenGoettingenGermany
| | - David Pacheu‐Grau
- Department of Cellular BiochemistryUniversity Medical Center GöttingenGöttingenGermany
| | - Fan Liu
- Leibniz‐Forschungsinstitut for Molecular Pharmacology (FMP)BerlinGermany
| | - Ying Zhu
- Leibniz‐Forschungsinstitut for Molecular Pharmacology (FMP)BerlinGermany
| | - Sven Dennerlein
- Department of Cellular BiochemistryUniversity Medical Center GöttingenGöttingenGermany
| | - Peter Rehling
- Department of Cellular BiochemistryUniversity Medical Center GöttingenGöttingenGermany
- Cluster of Excellence “Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells” (MBExC)University of GoettingenGoettingenGermany
- Max Planck Institute for Biophysical ChemistryGöttingenGermany
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Barbosa-Gouveia S, González-Vioque E, Borges F, Gutiérrez-Solana L, Wintjes L, Kappen A, van den Heuvel L, Leis R, Rodenburg R, Couce ML. Identification and Characterization of New Variants in FOXRED1 Gene Expands the Clinical Spectrum Associated with Mitochondrial Complex I Deficiency. J Clin Med 2019; 8:jcm8081262. [PMID: 31434271 PMCID: PMC6723710 DOI: 10.3390/jcm8081262] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Revised: 08/09/2019] [Accepted: 08/15/2019] [Indexed: 11/16/2022] Open
Abstract
Complex I (nicotinamide adenine dinucleotide (NADH): ubiquinone oxidoreductase) is the largest complex of the mitochondrial oxidative phosphorylation system (OXPHOS) system. Forty-four subunits encoded in nuclear and mitochondrial genomes compose this multiprotein complex, its assembly being a highly complex process involving at least 15 additional nuclear encoded assembly factors. Complex I deficiency is a mitochondrial disorder usually associated with early-onset severe multisystem disorders characterized by highly variable clinical manifestations. Flavin adenine dinucleotide (FAD)-dependent oxidoreductase domain-containing protein 1 (FOXRED1) is a complex I assembly factor. To date, only five patients with mitochondrial complex I deficiency due to mutations in FOXRED1 have been characterized. Here, we describe a child with ataxia, epilepsy and psychomotor developmental delay carrying two heterozygous FOXRED1 variants, c.920G>A (p.Gly307Glu) and c.733+1G>A. We demonstrate the molecular mechanism supporting the pathogenicity of the FOXRED1 variants, showing a clear deficiency of complex I activity. The reduction in the steady-state level of complex I holoenzyme in patient fibroblasts, confirmed the pathogenicity of the variants and showed the molecular mechanism behind their pathogenicity. A comparison of the clinical presentation of the index case with the previously described cases allowed deepening our knowledge about the clinical variability associated with FOXRED1 defects.
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Affiliation(s)
- Sofia Barbosa-Gouveia
- Diagnosis and Treatment of Congenital Metabolic Diseases Unit (UDyTEMC), Department of Pediatrics, Clinical University Hospital of Santiago de Compostela, 15706 Santiago de Compostela, Spain.
- Faculty of Medicine, University of Santiago de Compostela, 15706 Santiago de Compostela, Spain.
- IDIS-Health Research Institute of Santiago de Compostela, 15706 Santiago de Compostela, Spain.
| | - Emiliano González-Vioque
- Diagnosis and Treatment of Congenital Metabolic Diseases Unit (UDyTEMC), Department of Pediatrics, Clinical University Hospital of Santiago de Compostela, 15706 Santiago de Compostela, Spain
- IDIS-Health Research Institute of Santiago de Compostela, 15706 Santiago de Compostela, Spain
| | - Filipa Borges
- Diagnosis and Treatment of Congenital Metabolic Diseases Unit (UDyTEMC), Department of Pediatrics, Clinical University Hospital of Santiago de Compostela, 15706 Santiago de Compostela, Spain
| | - Luis Gutiérrez-Solana
- Unit of Child Neurology, Department of Pediatrics, Hospital Infantil Universitario Niño Jesús de Madrid, 28009 Madrid, Spain
| | - Liesbeth Wintjes
- Department of Paediatrics, Radboud Centre for Mitochondrial Medicine, Radboud University Medical Centre, 6525 GA Nijmegen, The Netherlands
| | - Antonia Kappen
- Department of Paediatrics, Radboud Centre for Mitochondrial Medicine, Radboud University Medical Centre, 6525 GA Nijmegen, The Netherlands
| | - Lambert van den Heuvel
- Department of Paediatrics, Radboud Centre for Mitochondrial Medicine, Radboud University Medical Centre, 6525 GA Nijmegen, The Netherlands
| | - Rosaura Leis
- IDIS-Health Research Institute of Santiago de Compostela, 15706 Santiago de Compostela, Spain
- Unit of Pediatric Gastroenterology and Nutrition Department of Pediatrics, Hospital Clínico Universitario de Santiago de Compostela, 15706 Santiago de Compostela, Spain
- CIBER Fisiopatología Obesidad y Nutrición (CIBEROBN), Instituto Salud Carlos III, 28029 Madrid, Spain
| | - Richard Rodenburg
- Department of Paediatrics, Radboud Centre for Mitochondrial Medicine, Radboud University Medical Centre, 6525 GA Nijmegen, The Netherlands
| | - María Luz Couce
- Diagnosis and Treatment of Congenital Metabolic Diseases Unit (UDyTEMC), Department of Pediatrics, Clinical University Hospital of Santiago de Compostela, 15706 Santiago de Compostela, Spain
- Faculty of Medicine, University of Santiago de Compostela, 15706 Santiago de Compostela, Spain
- IDIS-Health Research Institute of Santiago de Compostela, 15706 Santiago de Compostela, Spain
- CIBERER, Pabellón 11, 28029 Madrid, Spain
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Apatean D, Rakic B, Brunel-Guitton C, Hendson G, Bai R, Sargent MA, Lavoie PM, Patel M, Stockler-Ipsiroglu S. Congenital lactic acidosis, cerebral cysts and pulmonary hypertension in an infant with FOXRED1 related complex 1 deficiency. Mol Genet Metab Rep 2019; 19:100472. [PMID: 31065540 PMCID: PMC6495215 DOI: 10.1016/j.ymgmr.2019.100472] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Revised: 04/18/2019] [Accepted: 04/18/2019] [Indexed: 11/30/2022] Open
Abstract
Mitochondrial complex I is encoded by 38 nuclear-encoded and 7 mitochondrial-encoded genes. FOXRED1 is one of the 13 additional nuclear genes known as assembly factors. So far, four patients have been described with complex I deficiency caused by autosomal recessive mutations in FOXRED1. Here, we report the fifth patient with FOXRED1 related complex 1 deficiency presenting with prenatal onset of bilateral periventricular cysts, congenital lactic acidosis, and persistent life-limiting pulmonary hypertension. Whole exome sequencing identified a compound heterozygosity for a known pathogenic variant (c.612_615dupAGTG; p.A206SfsX15) (paternal) and a likely pathogenic variant (c.874G>A; p.Gly292Arg) (maternal). Deficiency of complex I was demonstrated by the absence of complex I on Blue Native Gel Electrophoresis and by a significantly reduced complex I enzyme activity in the patient's fibroblasts. Compared with the previous known FOXRED1 cases, unique clinical features observed in our patient include bilateral periventricular cysts and severe pulmonary hypertension. Whole exome sequencing was instrumental in recognizing the underlying gene defect in this patient.
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Affiliation(s)
- Delia Apatean
- Division of Biochemical Diseases, Department of Pediatric, BC Children's Hospital, UBC, Room K3-206, 4480 Oak Street, Vancouver, BC V6H 3V4, Canada
| | - Bojana Rakic
- BC Newborn Screening Program and Biochemical Genetics Lab, BC Children's Hospital and BC Women's Hospital & Health Centre, 2F16-4500 Oak Street, Vancouver, BC V6H 3N1, Canada
| | - Catherine Brunel-Guitton
- Department of Pediatrics, CHU Sainte-Justine, 3175, chemin Cote Sainte-Catherine, Montreal, QC H3T 1C5, Canada
| | - Glenda Hendson
- Department of Pathology, BC Children's Hospital and BC Women's Hospital & Health Centre, 2H56-4500 Oak Street, Vancouver, BC V6H 3N1, Canada
| | - Renkui Bai
- GeneDx, 207 Perry Parkway, Gaithersburg, MD 20877, United States of America
| | - Michael A Sargent
- Department of Radiology, BC Children's Hospital, University of British Columbia, Room 1L72, 4480 Oak Street, Vancouver, BC V6H 3V4, Canada
| | - Pascal M Lavoie
- BC Children's Hospital Research Institute, Room A4-147, 4th floor Translational Research Building, 950 West 28th Avenue, Vancouver, BC V5Z 4H4, Canada
| | - Millan Patel
- Department of Medical Genetics, UBC, Room C234, 4500 Oak Street, Vancouver, BC V6H 3N1, Canada
| | - Sylvia Stockler-Ipsiroglu
- Head Division of Biochemical Genetics, BC Children's Hospital, University of British Columbia, Room K3-205, 4480 Oak Street, Vancouver, BC V6H 3V4, Canada
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12
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Salama M, El-Desouky S, Alsayed A, El-Hussiny M, Moustafa A, Taalab Y, Mohamed W. FOXRED1 silencing in mice: a possible animal model for Leigh syndrome. Metab Brain Dis 2019; 34:367-372. [PMID: 30392038 DOI: 10.1007/s11011-018-0334-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Accepted: 10/30/2018] [Indexed: 01/12/2023]
Abstract
Leigh syndrome (LS) is one of the most puzzling mitochondrial disorders, which is also known as subacute necrotizing encephalopathy. It has an incidence of 1 in 77,000 live births worldwide with poor prognosis. Currently, there is a poor understanding of the underlying pathophysiological mechanisms of the disease without any available effective treatment. Hence, the inevitability for developing suitable animal and cellular models needed for the development of successful new therapeutic modalities. In this short report, we blocked FOXRED1 gene with small interfering RNA (siRNA) using C57bl/6 mice. Results showed neurobehavioral changes in the injected mice along with parallel degeneration in corpus striatum and sparing of the substantia nigra similar to what happen in Leigh syndrome cases. FOXRED1 blockage could serve as a new animal model for Leigh syndrome due to defective CI, which echoes damage to corpus striatum and affection of the central dopaminergic system in this disease. Further preclinical studies are required to validate this model.
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Affiliation(s)
- Mohamed Salama
- Medical Experimental Research Center (MERC), Faculty of Medicine, Mansoura University, Mansoura, Egypt.
- Toxicology Department, Faculty of Medicine, Mansoura University, Mansoura, Egypt.
| | - Sara El-Desouky
- Medical Experimental Research Center (MERC), Faculty of Medicine, Mansoura University, Mansoura, Egypt
| | - Aziza Alsayed
- Medical Experimental Research Center (MERC), Faculty of Medicine, Mansoura University, Mansoura, Egypt
| | - Mahmoud El-Hussiny
- Medical Experimental Research Center (MERC), Faculty of Medicine, Mansoura University, Mansoura, Egypt
| | - Abdelrahman Moustafa
- Medical Experimental Research Center (MERC), Faculty of Medicine, Mansoura University, Mansoura, Egypt
| | - Yasmeen Taalab
- Toxicology Department, Faculty of Medicine, Mansoura University, Mansoura, Egypt
| | - Wael Mohamed
- Clinical Pharmacology Department, Faculty of Medicine, Menoufia University, Shebeen El-Kom, Egypt
- Department of Basic Medical Science, Kulliyyah of Medicine, International Islamic University, Kuantan, Pahang, Malaysia
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13
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Apatean D, Rakic B, Brunel-Guitton C, Hendson G, Bai R, Sargent MA, Lavoie PM, Patel M, Stockler-Ipsiroglu S. Congenital lactic acidosis, cerebral cysts and pulmonary hypertension in an infant with FOXRED1 related complex I deficiency. Mol Genet Metab Rep 2019; 18:32-38. [PMID: 30723688 PMCID: PMC6349952 DOI: 10.1016/j.ymgmr.2018.12.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Revised: 12/19/2018] [Accepted: 12/19/2018] [Indexed: 12/12/2022] Open
Abstract
Mitochondrial complex I is encoded by 38 nuclear-encoded and 7 mitochondrial-encoded genes. FOXRED1 is one of the 13 additional nuclear genes known as assembly factors. So far, four patients have been described with complex I deficiency caused by autosomal recessive mutations in FOXRED1. Here, we report the fifth patient with FOXRED1 related complex 1 deficiency presenting with prenatal onset of bilateral periventricular cysts, congenital lactic acidosis, and persistent life-limiting pulmonary hypertension. Whole exome sequencing identified a compound heterozygosity for a known pathogenic variant (c.612_615dupAGTG; p.A206SfsX15) (paternal) and a likely pathogenic variant (c.874G > A; p.Gly292Arg) (maternal). Deficiency of complex I was demonstrated by the absence of complex I on Blue Native Gel Electrophoresis and by a significantly reduced complex I enzyme activity in the patient's fibroblasts. Compared with the previous known FOXRED1 cases, unique clinical features observed in our patient include bilateral periventricular cysts and severe pulmonary hypertension. Whole exome sequencing was instrumental in recognizing the underlying gene defect in this patient.
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Affiliation(s)
- Delia Apatean
- Division of Biochemical Diseases, Department of Pediatric, University of British Columbia, BC Children's Hospital, Room K3-206, 4480 Oak Street, Vancouver, BC V6H 3V4, Canada
| | - Bojana Rakic
- BC Newborn Screening Program and Biochemical Genetics Lab, BC Children's Hospital, BC Women's Hospital & Health Centre, 2F16-4500 Oak Street, Vancouver, BC V6H 3N1, Canada
| | - Catherine Brunel-Guitton
- Department of Pediatrics, CHU Sainte-Justine, 3175, chemin Cote Sainte-Catherine, Montreal, Quebec H3T 1C5, Canada
| | - Glenda Hendson
- Department of Pathology, BC Children's Hospital, BC Women's Hospital & Health Centre, 2H56-4500 Oak Street, Vancouver, BC V6H 3N1, Canada
| | - Renkui Bai
- GeneDx, 207 Perry Parkway, Gaithersburg, MD 20877, United States
| | - Michael A Sargent
- University of British Columbia, Department of Radiology, BC Children's Hospital, Room 1L72, 4480 Oak Street, Vancouver, BC V6H 3V4, Canada
| | - Pascal M Lavoie
- BC Children's Hospital Research Institute, Room A4-147, 4th floor Translational Research Building, 950 West 28th Avenue, Vancouver, BC V5Z 4H4, Canada
| | - Millan Patel
- Department of Medical Genetics, University of British Columbia, Room C234, 4500 Oak Street, Vancouver, BC V6H 3N1, Canada
| | - Sylvia Stockler-Ipsiroglu
- University of British Columbia, Head Division of Biochemical Genetics, BC Children's Hospital, Room K3-205, 4480 Oak Street, Vancouver, BC V6H 3V4, Canada
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14
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Abstract
Leigh syndrome (LS) is a common neurodegenerative disease affecting neonates with devastating sequences. One of the characteristic features for LS is the phenotypic polymorphism, which-in part-can be dedicated to variety of genetic causes. A strong correlation with mitochondrial dysfunction has been assumed as the main cause of LS. This was based on the fact that most genetic causes are related to mitochondrial complex I genome. The first animal LS model was designed based on NDUFS4 knockdown. Interestingly, however, this one or others could not recapitulate the whole spectrum of manifestations encountered in different cases of LS. We show in this chapter a new animal model for LS based on silencing of one gene that is reported previously in clinical cases, FOXRED1. The new model carries some differences from previous models in the fact that more histopathological degeneration in dopaminergic system is seen and more behavioral changes can be recognized. FOXRED1 is an interesting gene that is related to complex I assembly, hence, plays important role in different neurodegenerative disorders leading to different clinical manifestations.
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Affiliation(s)
- Sara El-Desouky
- Medical Experimental Research Center (MERC), Faculty of Medicine, Mansoura University, Mansoura, Egypt
| | - Yasmeen M Taalab
- Toxicology Department, Faculty of Medicine, Mansoura University, Mansoura, Egypt
- German Institute of Disaster Medicine and Emergency Medicine, Tubingen, Germany
| | - Mohamed El-Gamal
- Medical Experimental Research Center (MERC), Faculty of Medicine, Mansoura University, Mansoura, Egypt
- Toxicology Department, Faculty of Medicine, Mansoura University, Mansoura, Egypt
- IUF-Leibniz Research Institute for Environmental Medicine, Düsseldorf, Germany
| | - Wael Mohamed
- Clinical Pharmacology Department, Faculty of Medicine, Menoufia University, Al Minufya, Egypt
- Department of Basic Medical Science, Kulliyyah of Medicine, International Islamic University, Kuantan, Pahang, Malaysia
| | - Mohamed Salama
- Medical Experimental Research Center (MERC), Faculty of Medicine, Mansoura University, Mansoura, Egypt.
- Toxicology Department, Faculty of Medicine, Mansoura University, Mansoura, Egypt.
- Atlantic Fellow for Global Brain Health Institute (GBHI), Trinity College Dublin (TCD), Dublin, Ireland.
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15
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Assembly of mammalian oxidative phosphorylation complexes I-V and supercomplexes. Essays Biochem 2018; 62:255-270. [PMID: 30030361 PMCID: PMC6056720 DOI: 10.1042/ebc20170098] [Citation(s) in RCA: 141] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Revised: 05/08/2018] [Accepted: 05/11/2018] [Indexed: 01/30/2023]
Abstract
The assembly of the five oxidative phosphorylation system (OXPHOS) complexes in the inner mitochondrial membrane is an intricate process. The human enzymes comprise core proteins, performing the catalytic activities, and a large number of ‘supernumerary’ subunits that play essential roles in assembly, regulation and stability. The correct addition of prosthetic groups as well as chaperoning and incorporation of the structural components require a large number of factors, many of which have been found mutated in cases of mitochondrial disease. Nowadays, the mechanisms of assembly for each of the individual complexes are almost completely understood and the knowledge about the assembly factors involved is constantly increasing. On the other hand, it is now well established that complexes I, III and IV interact with each other, forming the so-called respiratory supercomplexes or ‘respirasomes’, although the pathways that lead to their formation are still not completely clear. This review is a summary of our current knowledge concerning the assembly of complexes I–V and of the supercomplexes.
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16
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Human diseases associated with defects in assembly of OXPHOS complexes. Essays Biochem 2018; 62:271-286. [PMID: 30030362 PMCID: PMC6056716 DOI: 10.1042/ebc20170099] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Revised: 04/13/2018] [Accepted: 05/02/2018] [Indexed: 02/02/2023]
Abstract
The structural biogenesis and functional proficiency of the multiheteromeric complexes forming the mitochondrial oxidative phosphorylation system (OXPHOS) require the concerted action of a number of chaperones and other assembly factors, most of which are specific for each complex. Mutations in a large number of these assembly factors are responsible for mitochondrial disorders, in most cases of infantile onset, typically characterized by biochemical defects of single specific complexes. In fact, pathogenic mutations in complex-specific assembly factors outnumber, in many cases, the repertoire of mutations found in structural subunits of specific complexes. The identification of patients with specific defects in assembly factors has provided an important contribution to the nosological characterization of mitochondrial disorders, and has also been a crucial means to identify a huge number of these proteins in humans, which play an essential role in mitochondrial bioenergetics. The wide use of next generation sequencing (NGS) has led to and will allow the identifcation of additional components of the assembly machinery of individual complexes, mutations of which are responsible for human disorders. The functional studies on patients' specimens, together with the creation and characterization of in vivo models, are fundamental to better understand the mechanisms of each of them. A new chapter in this field will be, in the near future, the discovery of mechanisms and actions underlying the formation of supercomplexes, molecular structures formed by the physical, and possibly functional, interaction of some of the individual respiratory complexes, particularly complex I (CI), III (CIII), and IV (CIV).
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Formosa LE, Dibley MG, Stroud DA, Ryan MT. Building a complex complex: Assembly of mitochondrial respiratory chain complex I. Semin Cell Dev Biol 2018; 76:154-162. [DOI: 10.1016/j.semcdb.2017.08.011] [Citation(s) in RCA: 85] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Revised: 07/26/2017] [Accepted: 08/04/2017] [Indexed: 10/19/2022]
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Castro JP, Wardelmann K, Grune T, Kleinridders A. Mitochondrial Chaperones in the Brain: Safeguarding Brain Health and Metabolism? Front Endocrinol (Lausanne) 2018; 9:196. [PMID: 29755410 PMCID: PMC5932182 DOI: 10.3389/fendo.2018.00196] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Accepted: 04/10/2018] [Indexed: 12/31/2022] Open
Abstract
The brain orchestrates organ function and regulates whole body metabolism by the concerted action of neurons and glia cells in the central nervous system. To do so, the brain has tremendously high energy consumption and relies mainly on glucose utilization and mitochondrial function in order to exert its function. As a consequence of high rate metabolism, mitochondria in the brain accumulate errors over time, such as mitochondrial DNA (mtDNA) mutations, reactive oxygen species, and misfolded and aggregated proteins. Thus, mitochondria need to employ specific mechanisms to avoid or ameliorate the rise of damaged proteins that contribute to aberrant mitochondrial function and oxidative stress. To maintain mitochondria homeostasis (mitostasis), cells evolved molecular chaperones that shuttle, refold, or in coordination with proteolytic systems, help to maintain a low steady-state level of misfolded/aggregated proteins. Their importance is exemplified by the occurrence of various brain diseases which exhibit reduced action of chaperones. Chaperone loss (expression and/or function) has been observed during aging, metabolic diseases such as type 2 diabetes and in neurodegenerative diseases such as Alzheimer's (AD), Parkinson's (PD) or even Huntington's (HD) diseases, where the accumulation of damage proteins is evidenced. Within this perspective, we propose that proper brain function is maintained by the joint action of mitochondrial chaperones to ensure and maintain mitostasis contributing to brain health, and that upon failure, alter brain function which can cause metabolic diseases.
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Affiliation(s)
- José Pedro Castro
- Department of Molecular Toxicology, German Institute of Human Nutrition (DIfE), Potsdam-Rehbruecke, Germany
- German Center for Diabetes Research (DZD), München-Neuherberg, Germany
- *Correspondence: José Pedro Castro, ; André Kleinridders,
| | - Kristina Wardelmann
- German Center for Diabetes Research (DZD), München-Neuherberg, Germany
- Central Regulation of Metabolism, German Institute of Human Nutrition (DIfE), Potsdam-Rehbruecke, Germany
| | - Tilman Grune
- Department of Molecular Toxicology, German Institute of Human Nutrition (DIfE), Potsdam-Rehbruecke, Germany
- German Center for Diabetes Research (DZD), München-Neuherberg, Germany
- German Center for Cardiovascular Research (DZHK), Berlin, Germany
- Institute of Nutritional Science, University of Potsdam, Nuthetal, Germany
| | - André Kleinridders
- German Center for Diabetes Research (DZD), München-Neuherberg, Germany
- Central Regulation of Metabolism, German Institute of Human Nutrition (DIfE), Potsdam-Rehbruecke, Germany
- *Correspondence: José Pedro Castro, ; André Kleinridders,
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