1
|
Antolínez-Fernández Á, Esteban-Ramos P, Fernández-Moreno MÁ, Clemente P. Molecular pathways in mitochondrial disorders due to a defective mitochondrial protein synthesis. Front Cell Dev Biol 2024; 12:1410245. [PMID: 38855161 PMCID: PMC11157125 DOI: 10.3389/fcell.2024.1410245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2024] [Accepted: 05/09/2024] [Indexed: 06/11/2024] Open
Abstract
Mitochondria play a central role in cellular metabolism producing the necessary ATP through oxidative phosphorylation. As a remnant of their prokaryotic past, mitochondria contain their own genome, which encodes 13 subunits of the oxidative phosphorylation system, as well as the tRNAs and rRNAs necessary for their translation in the organelle. Mitochondrial protein synthesis depends on the import of a vast array of nuclear-encoded proteins including the mitochondrial ribosome protein components, translation factors, aminoacyl-tRNA synthetases or assembly factors among others. Cryo-EM studies have improved our understanding of the composition of the mitochondrial ribosome and the factors required for mitochondrial protein synthesis and the advances in next-generation sequencing techniques have allowed for the identification of a growing number of genes involved in mitochondrial pathologies with a defective translation. These disorders are often multisystemic, affecting those tissues with a higher energy demand, and often present with neurodegenerative phenotypes. In this article, we review the known proteins required for mitochondrial translation, the disorders that derive from a defective mitochondrial protein synthesis and the animal models that have been established for their study.
Collapse
Affiliation(s)
- Álvaro Antolínez-Fernández
- Instituto de Investigaciones Biomédicas Sols-Morreale (IIBM), Universidad Autónoma de Madrid-Consejo Superior de Investigaciones Científicas, Madrid, Spain
- Departamento de Bioquímica, Universidad Autónoma de Madrid, Madrid, Spain
| | - Paula Esteban-Ramos
- Instituto de Investigaciones Biomédicas Sols-Morreale (IIBM), Universidad Autónoma de Madrid-Consejo Superior de Investigaciones Científicas, Madrid, Spain
- Departamento de Bioquímica, Universidad Autónoma de Madrid, Madrid, Spain
| | - Miguel Ángel Fernández-Moreno
- Instituto de Investigaciones Biomédicas Sols-Morreale (IIBM), Universidad Autónoma de Madrid-Consejo Superior de Investigaciones Científicas, Madrid, Spain
- Departamento de Bioquímica, Universidad Autónoma de Madrid, Madrid, Spain
| | - Paula Clemente
- Instituto de Investigaciones Biomédicas Sols-Morreale (IIBM), Universidad Autónoma de Madrid-Consejo Superior de Investigaciones Científicas, Madrid, Spain
- Departamento de Bioquímica, Universidad Autónoma de Madrid, Madrid, Spain
| |
Collapse
|
2
|
Hughes LA, Rackham O, Filipovska A. Illuminating mitochondrial translation through mouse models. Hum Mol Genet 2024; 33:R61-R79. [PMID: 38779771 PMCID: PMC11112386 DOI: 10.1093/hmg/ddae020] [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: 11/10/2023] [Revised: 01/22/2024] [Accepted: 01/31/2024] [Indexed: 05/25/2024] Open
Abstract
Mitochondria are hubs of metabolic activity with a major role in ATP conversion by oxidative phosphorylation (OXPHOS). The mammalian mitochondrial genome encodes 11 mRNAs encoding 13 OXPHOS proteins along with 2 rRNAs and 22 tRNAs, that facilitate their translation on mitoribosomes. Maintaining the internal production of core OXPHOS subunits requires modulation of the mitochondrial capacity to match the cellular requirements and correct insertion of particularly hydrophobic proteins into the inner mitochondrial membrane. The mitochondrial translation system is essential for energy production and defects result in severe, phenotypically diverse diseases, including mitochondrial diseases that typically affect postmitotic tissues with high metabolic demands. Understanding the complex mechanisms that underlie the pathologies of diseases involving impaired mitochondrial translation is key to tailoring specific treatments and effectively targeting the affected organs. Disease mutations have provided a fundamental, yet limited, understanding of mitochondrial protein synthesis, since effective modification of the mitochondrial genome has proven challenging. However, advances in next generation sequencing, cryoelectron microscopy, and multi-omic technologies have revealed unexpected and unusual features of the mitochondrial protein synthesis machinery in the last decade. Genome editing tools have generated unique models that have accelerated our mechanistic understanding of mitochondrial translation and its physiological importance. Here we review the most recent mouse models of disease pathogenesis caused by defects in mitochondrial protein synthesis and discuss their value for preclinical research and therapeutic development.
Collapse
Affiliation(s)
- Laetitia A Hughes
- Telethon Kids Institute, Northern Entrance, Perth Children’s Hospital, 15 Hospital Avenue, Nedlands, WA 6009, Australia
- Harry Perkins Institute of Medical Research, 6 Verdun Street, Nedlands, WA 6009, Australia
- ARC Centre of Excellence in Synthetic Biology, 35 Stirling Highway, Crawley, WA 6009, The University of Western Australia, Crawley, WA 6009, Australia
| | - Oliver Rackham
- Telethon Kids Institute, Northern Entrance, Perth Children’s Hospital, 15 Hospital Avenue, Nedlands, WA 6009, Australia
- Harry Perkins Institute of Medical Research, 6 Verdun Street, Nedlands, WA 6009, Australia
- ARC Centre of Excellence in Synthetic Biology, 35 Stirling Highway, Crawley, WA 6009, The University of Western Australia, Crawley, WA 6009, Australia
- Curtin Medical School, Curtin University, Kent Street, Bentley, WA 6102, Australia
- Curtin Health Innovation Research Institute, Curtin University, Kent Street, Bentley, WA 6102, Australia
| | - Aleksandra Filipovska
- Telethon Kids Institute, Northern Entrance, Perth Children’s Hospital, 15 Hospital Avenue, Nedlands, WA 6009, Australia
- ARC Centre of Excellence in Synthetic Biology, 35 Stirling Highway, Crawley, WA 6009, The University of Western Australia, Crawley, WA 6009, Australia
- Department of Biochemistry and Molecular Biology, Monash Biomedicine Discovery Institute, Monash University, 19 Innovation Walk, Clayton, Clayton, VIC 3168, Australia
| |
Collapse
|
3
|
Hoogstraten CA, Hoenderop JG, de Baaij JHF. Mitochondrial Dysfunction in Kidney Tubulopathies. Annu Rev Physiol 2024; 86:379-403. [PMID: 38012047 DOI: 10.1146/annurev-physiol-042222-025000] [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] [Indexed: 11/29/2023]
Abstract
Mitochondria play a key role in kidney physiology and pathology. They produce ATP to fuel energy-demanding water and solute reabsorption processes along the nephron. Moreover, mitochondria contribute to cellular health by the regulation of autophagy, (oxidative) stress responses, and apoptosis. Mitochondrial abundance is particularly high in cortical segments, including proximal and distal convoluted tubules. Dysfunction of the mitochondria has been described for tubulopathies such as Fanconi, Gitelman, and Bartter-like syndromes and renal tubular acidosis. In addition, mitochondrial cytopathies often affect renal (tubular) tissues, such as in Kearns-Sayre and Leigh syndromes. Nevertheless, the mechanisms by which mitochondrial dysfunction results in renal tubular diseases are only scarcely being explored. This review provides an overview of mitochondrial dysfunction in the development and progression of kidney tubulopathies. Furthermore, it emphasizes the need for further mechanistic investigations to identify links between mitochondrial function and renal electrolyte reabsorption.
Collapse
Affiliation(s)
- Charlotte A Hoogstraten
- Department of Medical Biosciences, Radboud University Medical Center, Nijmegen, The Netherlands;
| | - Joost G Hoenderop
- Department of Medical Biosciences, Radboud University Medical Center, Nijmegen, The Netherlands;
| | - Jeroen H F de Baaij
- Department of Medical Biosciences, Radboud University Medical Center, Nijmegen, The Netherlands;
| |
Collapse
|
4
|
Amarasekera SSC, Hock DH, Lake NJ, Calvo SE, Grønborg SW, Krzesinski EI, Amor DJ, Fahey MC, Simons C, Wibrand F, Mootha VK, Lek M, Lunke S, Stark Z, Østergaard E, Christodoulou J, Thorburn DR, Stroud DA, Compton AG. Multi-omics identifies large mitoribosomal subunit instability caused by pathogenic MRPL39 variants as a cause of pediatric onset mitochondrial disease. Hum Mol Genet 2023; 32:2441-2454. [PMID: 37133451 PMCID: PMC10360397 DOI: 10.1093/hmg/ddad069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Revised: 03/20/2023] [Accepted: 04/24/2023] [Indexed: 05/04/2023] Open
Abstract
MRPL39 encodes one of 52 proteins comprising the large subunit of the mitochondrial ribosome (mitoribosome). In conjunction with 30 proteins in the small subunit, the mitoribosome synthesizes the 13 subunits of the mitochondrial oxidative phosphorylation (OXPHOS) system encoded by mitochondrial Deoxyribonucleic acid (DNA). We used multi-omics and gene matching to identify three unrelated individuals with biallelic variants in MRPL39 presenting with multisystem diseases with severity ranging from lethal, infantile-onset (Leigh syndrome spectrum) to milder with survival into adulthood. Clinical exome sequencing of known disease genes failed to diagnose these patients; however quantitative proteomics identified a specific decrease in the abundance of large but not small mitoribosomal subunits in fibroblasts from the two patients with severe phenotype. Re-analysis of exome sequencing led to the identification of candidate single heterozygous variants in mitoribosomal genes MRPL39 (both patients) and MRPL15. Genome sequencing identified a shared deep intronic MRPL39 variant predicted to generate a cryptic exon, with transcriptomics and targeted studies providing further functional evidence for causation. The patient with the milder disease was homozygous for a missense variant identified through trio exome sequencing. Our study highlights the utility of quantitative proteomics in detecting protein signatures and in characterizing gene-disease associations in exome-unsolved patients. We describe Relative Complex Abundance analysis of proteomics data, a sensitive method that can identify defects in OXPHOS disorders to a similar or greater sensitivity to the traditional enzymology. Relative Complex Abundance has potential utility for functional validation or prioritization in many hundreds of inherited rare diseases where protein complex assembly is disrupted.
Collapse
Affiliation(s)
- Sumudu S C Amarasekera
- Murdoch Children’s Research Institute, Royal Children's Hospital, Melbourne, VIC 3052, Australia
- Department of Paediatrics, University of Melbourne, Melbourne, VIC 3010, Australia
| | - Daniella H Hock
- Department of Biochemistry and Pharmacology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, VIC 3010, Australia
| | - Nicole J Lake
- Murdoch Children’s Research Institute, Royal Children's Hospital, Melbourne, VIC 3052, Australia
- Department of Genetics, Yale School of Medicine, New Haven, CT 06510 USA
| | - Sarah E Calvo
- Broad Institute, Cambridge, MA 02142, USA
- Howard Hughes Medical Institute and Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA
- Department of Systems Biology, Harvard Medical School, Boston, MA 02446, USA
| | - Sabine W Grønborg
- Department of Genetics, Copenhagen University Hospital Rigshospitalet, Copenhagen 2100, Denmark
- Center for Inherited Metabolic Disease, Department of Pediatrics and Adolescent Medicine, Copenhagen University Hospital Rigshospitalet, Copenhagen 2100, Denmark
| | - Emma I Krzesinski
- Monash Genetics, Monash Health, Melbourne, VIC 3168 Australia
- Department of Paediatrics, Monash University, Melbourne, VIC 3168 Australia
| | - David J Amor
- Murdoch Children’s Research Institute, Royal Children's Hospital, Melbourne, VIC 3052, Australia
- Department of Paediatrics, University of Melbourne, Melbourne, VIC 3010, Australia
| | - Michael C Fahey
- Monash Genetics, Monash Health, Melbourne, VIC 3168 Australia
- Department of Paediatrics, Monash University, Melbourne, VIC 3168 Australia
| | - Cas Simons
- Murdoch Children’s Research Institute, Royal Children's Hospital, Melbourne, VIC 3052, Australia
| | - Flemming Wibrand
- Department of Genetics, Copenhagen University Hospital Rigshospitalet, Copenhagen 2100, Denmark
| | - Vamsi K Mootha
- Broad Institute, Cambridge, MA 02142, USA
- Howard Hughes Medical Institute and Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA
- Department of Systems Biology, Harvard Medical School, Boston, MA 02446, USA
| | - Monkol Lek
- Department of Genetics, Yale School of Medicine, New Haven, CT 06510 USA
| | - Sebastian Lunke
- Victorian Clinical Genetics Services, Murdoch Children’s Research Institute, Melbourne, VIC 3052, Australia
- Australian Genomics Health Alliance, Melbourne, VIC 3052, Australia
- Department of Pathology, University of Melbourne, Melbourne, VIC 3010, Australia
| | - Zornitza Stark
- Department of Paediatrics, University of Melbourne, Melbourne, VIC 3010, Australia
- Victorian Clinical Genetics Services, Murdoch Children’s Research Institute, Melbourne, VIC 3052, Australia
- Australian Genomics Health Alliance, Melbourne, VIC 3052, Australia
| | - Elsebet Østergaard
- Department of Genetics, Copenhagen University Hospital Rigshospitalet, Copenhagen 2100, Denmark
- Department of Clinical Medicine, University of Copenhagen, Copenhagen 2200, Denmark
| | - John Christodoulou
- Murdoch Children’s Research Institute, Royal Children's Hospital, Melbourne, VIC 3052, Australia
- Department of Paediatrics, University of Melbourne, Melbourne, VIC 3010, Australia
- Victorian Clinical Genetics Services, Murdoch Children’s Research Institute, Melbourne, VIC 3052, Australia
- Australian Genomics Health Alliance, Melbourne, VIC 3052, Australia
- Discipline of Child & Adolescent Health, Sydney Medical School, University of Sydney, Sydney, NSW 2006, Australia
| | - David R Thorburn
- Murdoch Children’s Research Institute, Royal Children's Hospital, Melbourne, VIC 3052, Australia
- Department of Paediatrics, University of Melbourne, Melbourne, VIC 3010, Australia
- Victorian Clinical Genetics Services, Murdoch Children’s Research Institute, Melbourne, VIC 3052, Australia
- Australian Genomics Health Alliance, Melbourne, VIC 3052, Australia
| | - David A Stroud
- Murdoch Children’s Research Institute, Royal Children's Hospital, Melbourne, VIC 3052, Australia
- Department of Biochemistry and Pharmacology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, VIC 3010, Australia
- Victorian Clinical Genetics Services, Murdoch Children’s Research Institute, Melbourne, VIC 3052, Australia
| | - Alison G Compton
- Murdoch Children’s Research Institute, Royal Children's Hospital, Melbourne, VIC 3052, Australia
- Department of Paediatrics, University of Melbourne, Melbourne, VIC 3010, Australia
- Victorian Clinical Genetics Services, Murdoch Children’s Research Institute, Melbourne, VIC 3052, Australia
| |
Collapse
|
5
|
Ji X, Chu L, Su D, Sun J, Song P, Sun S, Wang Y, Mu Q, Liu Y, Wan Q. MRPL12-ANT3 interaction involves in acute kidney injury via regulating MPTP of tubular epithelial cells. iScience 2023; 26:106656. [PMID: 37182101 PMCID: PMC10173734 DOI: 10.1016/j.isci.2023.106656] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 04/04/2023] [Accepted: 04/07/2023] [Indexed: 05/16/2023] Open
Abstract
Acute kidney injury (AKI) is a serious disease with no effective treatment. Abnormal opening of mitochondrial permeability transition pore (MPTP) is an important pathological process in ischemia reperfusion injury (IRI), the key factor of AKI. It is essential to elucidate MPTP regulation mechanism. Here, we identified mitochondrial ribosomal protein L7/L12 (MRPL12) specifically binds to adenosine nucleotide translocase 3 (ANT3) under normal physiological conditions, stabilizes MPTP and maintains mitochondrial membrane homeostasis in renal tubular epithelial cells (TECs). During AKI, MRPL12 expression was significantly decreased in TECs, and MRPL12-ANT3 interaction was reduced, leading to ANT3 conformation change, MPTP abnormal opening, and cell apoptosis. Importantly, MRPL12 overexpression protected TECs from MPTP abnormal opening and apoptosis during hypoxia/reoxygenation (H/R). Our results suggest MRPL12-ANT3 axis involves in AKI by regulating MPTP, and MRPL12 could be potential intervention target for treatment of AKI.
Collapse
Affiliation(s)
- Xingzhao Ji
- Center of Cell Metabolism and Disease, Central Hospital Affiliated to Shandong First Medical University, Jinan, Shandong 250021, China
- Department of Pulmonary and Critical Care Medicine, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong 250021, China
- Shandong Key Laboratory of Infections Respiratory Disease, Jinan, Shandong 250021, China
- Medical Science and Technology Innovation Center, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, Shandong 250021, China
| | - Lingju Chu
- Center of Cell Metabolism and Disease, Central Hospital Affiliated to Shandong First Medical University, Jinan, Shandong 250021, China
- Key Laboratory of Cell Metabolism in Medical and Health of Shandong Provincial Health Commission, Central Hospital Affiliated to Shandong First Medical University, Jinan, Shandong 250021, China
| | - Dun Su
- Center of Cell Metabolism and Disease, Central Hospital Affiliated to Shandong First Medical University, Jinan, Shandong 250021, China
- Key Laboratory of Cell Metabolism in Medical and Health of Shandong Provincial Health Commission, Central Hospital Affiliated to Shandong First Medical University, Jinan, Shandong 250021, China
| | - Jian Sun
- Department of Pulmonary and Critical Care Medicine, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong 250021, China
- Shandong Key Laboratory of Infections Respiratory Disease, Jinan, Shandong 250021, China
- Medical Science and Technology Innovation Center, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, Shandong 250021, China
| | - Peng Song
- Department of Pulmonary and Critical Care Medicine, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong 250021, China
- Shandong Key Laboratory of Infections Respiratory Disease, Jinan, Shandong 250021, China
- Medical Science and Technology Innovation Center, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, Shandong 250021, China
| | - Shengnan Sun
- Center of Cell Metabolism and Disease, Central Hospital Affiliated to Shandong First Medical University, Jinan, Shandong 250021, China
- Key Laboratory of Cell Metabolism in Medical and Health of Shandong Provincial Health Commission, Central Hospital Affiliated to Shandong First Medical University, Jinan, Shandong 250021, China
| | - Ying Wang
- Department of Pulmonary and Critical Care Medicine, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong 250021, China
- Shandong Key Laboratory of Infections Respiratory Disease, Jinan, Shandong 250021, China
- Medical Science and Technology Innovation Center, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, Shandong 250021, China
| | - Qian Mu
- Department of Pulmonary and Critical Care Medicine, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong 250021, China
- Shandong Key Laboratory of Infections Respiratory Disease, Jinan, Shandong 250021, China
- Medical Science and Technology Innovation Center, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, Shandong 250021, China
| | - Yi Liu
- Department of Pulmonary and Critical Care Medicine, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong 250021, China
- Department of Pulmonary and Critical Care Medicine, Shandong Provincial Hospital, Shandong University, Jinan, Shandong 250021, China
- Shandong Key Laboratory of Infections Respiratory Disease, Jinan, Shandong 250021, China
- Medical Science and Technology Innovation Center, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, Shandong 250021, China
- Corresponding author
| | - Qiang Wan
- Center of Cell Metabolism and Disease, Central Hospital Affiliated to Shandong First Medical University, Jinan, Shandong 250021, China
- Key Laboratory of Cell Metabolism in Medical and Health of Shandong Provincial Health Commission, Central Hospital Affiliated to Shandong First Medical University, Jinan, Shandong 250021, China
- Corresponding author
| |
Collapse
|
6
|
Conor Moran J, Del'Olio S, Choi A, Zhong H, Barrientos A. Mitoribosome Biogenesis. Methods Mol Biol 2023; 2661:23-51. [PMID: 37166630 PMCID: PMC10639111 DOI: 10.1007/978-1-0716-3171-3_3] [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] [Indexed: 05/12/2023]
Abstract
Mitoribosome biogenesis is a complex and energetically costly process that involves RNA elements encoded in the mitochondrial genome and mitoribosomal proteins most frequently encoded in the nuclear genome. The process is catalyzed by extra-ribosomal proteins, nucleus-encoded assembly factors that act in all stages of the assembly process to coordinate the processing and maturation of ribosomal RNAs with the hierarchical association of ribosomal proteins. Biochemical studies and recent cryo-EM structures of mammalian mitoribosomes have provided hints regarding their assembly. In this general concept chapter, we will briefly describe the current knowledge, mainly regarding the mammalian mitoribosome biogenesis pathway and factors involved, and will emphasize the biological sources and approaches that have been applied to advance the field.
Collapse
Affiliation(s)
- J Conor Moran
- Department of Biochemistry and Molecular Biology, University of Miami, Miller School of Medicine, Miami, FL, USA
| | - Samuel Del'Olio
- Department of Molecular and Cellular Pharmacology, University of Miami, Miller School of Medicine, Miami, FL, USA
| | - Austin Choi
- Department of Neurology, University of Miami, Miller School of Medicine, Miami, FL, USA
| | - Hui Zhong
- Department of Biochemistry and Molecular Biology, University of Miami, Miller School of Medicine, Miami, FL, USA
| | - Antoni Barrientos
- Department of Neurology and Department of Biochemistry and Molecular Biology, University of Miami, Miller School of Medicine, Miami, FL, USA.
| |
Collapse
|
7
|
Silencing of the mitochondrial ribosomal protein L-24 gene activates the oxidative stress response in Caenorhabditis elegans. Biochim Biophys Acta Gen Subj 2023; 1867:130255. [PMID: 36265765 DOI: 10.1016/j.bbagen.2022.130255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Revised: 10/09/2022] [Accepted: 10/12/2022] [Indexed: 11/13/2022]
Abstract
The mitochondrial translation machinery allows the synthesis of the mitochondrial-encoded subunits of the electron transport chain. Defects in this process lead to mitochondrial physiology failure; in humans, they are associated with early-onset, extremely variable and often fatal disorder. The use of a simple model to study the mitoribosomal defects is mandatory to overcome the difficulty to analyze the impact of pathological mutations in humans. In this paper we study in nematode Caenorhabditis elegans the silencing effect of the mrpl-24 gene, coding for the mitochondrial ribosomal protein L-24 (MRPL-24). This is a structural protein of the large subunit 39S of the mitoribosome and its effective physiological function is not completely elucidated. We have evaluated the nematode's fitness fault and investigated the mitochondrial defects associated with MRPL-24 depletion. The oxidative stress response activation due to the mitochondrial alteration has been also investigated as a compensatory physiological mechanism. For the first time, we demonstrated that MRPL-24 reduction increases the expression of detoxifying enzymes such as SOD-3 and GST-4 through the involvement of transcription factor SKN-1. BACKGROUND In humans, mutations in genes encoding mitochondrial ribosomal proteins (MRPs) often cause early-onset, severe, fatal and extremely variable clinical defects. Mitochondrial ribosomal protein L-24 (MRPL24) is a structural protein of the large subunit 39S of the mitoribosome. It is highly conserved in different species and its effective physiological function is not completely elucidated. METHODS We characterized the MRPL24 functionality using the animal model Caenorhabditis elegans. We performed the RNA mediated interference (RNAi) by exposing the nematodes' embryos to double-stranded RNA (dsRNA) specific for the MRPL-24 coding sequence. We investigated for the first time in C. elegans, the involvement of the MRPL-24 on the nematode's fitness and its mitochondrial physiology. RESULTS Mrpl-24 silencing in C. elegans negatively affected the larval development, progeny production and body bending. The analysis of mitochondrial functionality revealed loss of mitochondrial network and impairment of mitochondrial functionality, as the decrease of oxygen consumption rate and the ROS production, as well as reduction of mitochondrial protein synthesis. Finally, the MRPL-24 depletion activated the oxidative stress response, increasing the expression levels of two detoxifying enzymes, SOD-3 and GST-4. CONCLUSIONS In C. elegans the MRPL-24 depletion activated the oxidative stress response. This appears as a compensatory mechanism to the alteration of the mitochondrial functionality and requires the involvement of transcription factor SKN-1. GENERAL SIGNIFICANCE C. elegans resulted in a good model for the study of mitochondrial disorders and its use as a simple and pluricellular organism could open interesting perspectives to better investigate the pathologic mechanisms underlying these devastating diseases.
Collapse
|
8
|
Muñoz‐Pujol G, Ortigoza‐Escobar JD, Paredes‐Fuentes AJ, Jou C, Ugarteburu O, Gort L, Yubero D, García‐Cazorla A, O'Callaghan M, Campistol J, Muchart J, Yépez VA, Gusic M, Gagneur J, Prokisch H, Artuch R, Ribes A, Urreizti R, Tort F. Leigh syndrome is the main clinical characteristic of
PTCD3
deficiency. Brain Pathol 2022; 33:e13134. [PMID: 36450274 PMCID: PMC10154364 DOI: 10.1111/bpa.13134] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Accepted: 11/16/2022] [Indexed: 12/05/2022] Open
Abstract
Mitochondrial translation defects are a continuously growing group of disorders showing a large variety of clinical symptoms including a wide range of neurological abnormalities. To date, mutations in PTCD3, encoding a component of the mitochondrial ribosome, have only been reported in a single individual with clinical evidence of Leigh syndrome. Here, we describe three additional PTCD3 individuals from two unrelated families, broadening the genetic and phenotypic spectrum of this disorder, and provide definitive evidence that PTCD3 deficiency is associated with Leigh syndrome. The patients presented in the first months of life with psychomotor delay, respiratory insufficiency and feeding difficulties. The neurologic phenotype included dystonia, optic atrophy, nystagmus and tonic-clonic seizures. Brain MRI showed optic nerve atrophy and thalamic changes, consistent with Leigh syndrome. WES and RNA-seq identified compound heterozygous variants in PTCD3 in both families: c.[1453-1G>C];[1918C>G] and c.[710del];[902C>T]. The functional consequences of the identified variants were determined by a comprehensive characterization of the mitochondrial function. PTCD3 protein levels were significantly reduced in patient fibroblasts and, consistent with a mitochondrial translation defect, a severe reduction in the steady state levels of complexes I and IV subunits was detected. Accordingly, the activity of these complexes was also low, and high-resolution respirometry showed a significant decrease in the mitochondrial respiratory capacity. Functional complementation studies demonstrated the pathogenic effect of the identified variants since the expression of wild-type PTCD3 in immortalized fibroblasts restored the steady-state levels of complexes I and IV subunits as well as the mitochondrial respiratory capacity. Additionally, minigene assays demonstrated that three of the identified variants were pathogenic by altering PTCD3 mRNA processing. The fourth variant was a frameshift leading to a truncated protein. In summary, we provide evidence of PTCD3 involvement in human disease confirming that PTCD3 deficiency is definitively associated with Leigh syndrome.
Collapse
Affiliation(s)
- Gerard Muñoz‐Pujol
- Secció d'Errors Congènits del Metabolisme‐IBC, Servei de Bioquímica i Genètica Molecular Hospital Clínic de Barcelona, IDIBAPS, CIBERER Barcelona Spain
| | | | - Abraham J. Paredes‐Fuentes
- Clinical Biochemistry and Molecular Medicine and Genetics Departments Institut de Recerca Sant Joan de Déu, Hospital Sant Joan de Déu, and CIBERER Esplugues de Llobregat Barcelona Spain
| | - Cristina Jou
- Pathology Department, Institut de Recerca Sant Joan de Déu Hospital Sant Joan de Déu, University of Barcelona, CIBERER Esplugues de Llobregat Barcelona Spain
| | - Olatz Ugarteburu
- Secció d'Errors Congènits del Metabolisme‐IBC, Servei de Bioquímica i Genètica Molecular Hospital Clínic de Barcelona, IDIBAPS, CIBERER Barcelona Spain
| | - Laura Gort
- Secció d'Errors Congènits del Metabolisme‐IBC, Servei de Bioquímica i Genètica Molecular Hospital Clínic de Barcelona, IDIBAPS, CIBERER Barcelona Spain
| | - Delia Yubero
- Clinical Biochemistry and Molecular Medicine and Genetics Departments Institut de Recerca Sant Joan de Déu, Hospital Sant Joan de Déu, and CIBERER Esplugues de Llobregat Barcelona Spain
| | - Angels García‐Cazorla
- Pediatric Neurology Department Hospital Sant Joan de Déu Esplugues de Llobregat Barcelona Spain
| | - Mar O'Callaghan
- Pediatric Neurology Department Hospital Sant Joan de Déu Esplugues de Llobregat Barcelona Spain
| | - Jaume Campistol
- Pediatric Neurology Department Hospital Sant Joan de Déu Esplugues de Llobregat Barcelona Spain
| | - Jordi Muchart
- Pediatric Radiology Department Institut de Recerca Sant Joan de Déu, Hospital Sant Joan de Déu Esplugues de Llobregat Barcelona Spain
| | - Vicente A. Yépez
- School of Medicine Institute of Human Genetics, Technische Universität München Munich Germany
- Department of Informatics Technical University of Munich Garching Germany
| | - Mirjana Gusic
- School of Medicine Institute of Human Genetics, Technische Universität München Munich Germany
- Institute of Neurogenomics, Helmholtz Zentrum München Neuherberg Germany
| | - Julien Gagneur
- School of Medicine Institute of Human Genetics, Technische Universität München Munich Germany
- Department of Informatics Technical University of Munich Garching Germany
| | - Holger Prokisch
- School of Medicine Institute of Human Genetics, Technische Universität München Munich Germany
- Institute of Neurogenomics, Helmholtz Zentrum München Neuherberg Germany
| | - Rafael Artuch
- Clinical Biochemistry and Molecular Medicine and Genetics Departments Institut de Recerca Sant Joan de Déu, Hospital Sant Joan de Déu, and CIBERER Esplugues de Llobregat Barcelona Spain
| | - Antonia Ribes
- Secció d'Errors Congènits del Metabolisme‐IBC, Servei de Bioquímica i Genètica Molecular Hospital Clínic de Barcelona, IDIBAPS, CIBERER Barcelona Spain
| | - Roser Urreizti
- Clinical Biochemistry and Molecular Medicine and Genetics Departments Institut de Recerca Sant Joan de Déu, Hospital Sant Joan de Déu, and CIBERER Esplugues de Llobregat Barcelona Spain
| | - Frederic Tort
- Secció d'Errors Congènits del Metabolisme‐IBC, Servei de Bioquímica i Genètica Molecular Hospital Clínic de Barcelona, IDIBAPS, CIBERER Barcelona Spain
| |
Collapse
|
9
|
Abstract
The human brain consumes five orders of magnitude more energy than the sun by unit of mass and time. This staggering bioenergetic cost serves mostly synaptic transmission and actin cytoskeleton dynamics. The peak of both brain bioenergetic demands and the age of onset for neurodevelopmental disorders is approximately 5 years of age. This correlation suggests that defects in the machinery that provides cellular energy would be causative and/or consequence of neurodevelopmental disorders. We explore this hypothesis from the perspective of the machinery required for the synthesis of the electron transport chain, an ATP-producing and NADH-consuming enzymatic cascade. The electron transport chain is constituted by nuclear- and mitochondrial-genome-encoded subunits. These subunits are synthesized by the 80S and the 55S ribosomes, which are segregated to the cytoplasm and the mitochondrial matrix, correspondingly. Mitochondrial protein synthesis by the 55S ribosome is the rate-limiting step in the synthesis of electron transport chain components, suggesting that mitochondrial protein synthesis is a bottleneck for tissues with high bionergetic demands. We discuss genetic defects in the human nuclear and mitochondrial genomes that affect these protein synthesis machineries and cause a phenotypic spectrum spanning autism spectrum disorders to neurodegeneration during neurodevelopment. We propose that dysregulated mitochondrial protein synthesis is a chief, yet understudied, causative mechanism of neurodevelopmental and behavioral disorders.
Collapse
|
10
|
Del Giudice L, Alifano P, Calcagnile M, Di Schiavi E, Bertapelle C, Aletta M, Pontieri P. Mitochondrial ribosomal protein genes connected with Alzheimer's and tellurite toxicity. Mitochondrion 2022; 64:45-58. [PMID: 35218961 DOI: 10.1016/j.mito.2022.02.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Revised: 02/15/2022] [Accepted: 02/21/2022] [Indexed: 12/19/2022]
Abstract
Mitochondrial diseases are a group of genetic disorders characterized by dysfunctional mitochondria. Within eukaryotic cells, mitochondria contain their own ribosomes, which synthesize small amounts of proteins, all of which are essential for the biogenesis of the oxidative phosphorylation system. The ribosome is an evolutionarily conserved macromolecular machine in nature both from a structural and functional point of view, universally responsible for the synthesis of proteins. Among the diseases afflicting humans, those of ribosomal origin - either cytoplasmic ribosomes (80S) or mitochondrial ribosomes (70S) - are relevant. These are inherited or acquired diseases most commonly caused by either ribosomal protein haploinsufficiency or defects in ribosome biogenesis. Here we review the scientific literature about the recent advances on changes in mitochondrial ribosomal structural and assembly proteins that are implicated in primary mitochondrial diseases and neurodegenerative disorders, and their possible connection with metalloid pollution and toxicity, with a focus on MRPL44, NAM9 (MNA6) and GEP3 (MTG3), whose lack or defect was associated with resistance to tellurite. Finally, we illustrate the suitability of yeast Saccharomyces cerevisiae (S.cerevisiae) and the nematode Caenorhabditis elegans (C.elegans) as model organisms for studying mitochondrial ribosome dysfunctions including those involved in human diseases.
Collapse
Affiliation(s)
- Luigi Del Giudice
- Istituto di Bioscienze e BioRisorse-UOS Napoli-CNR c/o Dipartimento di Biologia, Sezione di Igiene, Napoli 80134, Italy.
| | - Pietro Alifano
- Dipartimento di Scienze e Tecnologie Biologiche e Ambientali, Università del Salento, Lecce 73100, Italy
| | - Matteo Calcagnile
- Dipartimento di Scienze e Tecnologie Biologiche e Ambientali, Università del Salento, Lecce 73100, Italy
| | | | | | | | - Paola Pontieri
- Istituto di Bioscienze e BioRisorse-UOS Napoli-CNR c/o Dipartimento di Biologia, Sezione di Igiene, Napoli 80134, Italy
| |
Collapse
|
11
|
Liu C, Zhou W, Liu Q, Peng Z. Hypoglycemia with lactic acidosis caused by a new MRPS2 gene mutation in a Chinese girl: a case report. BMC Endocr Disord 2022; 22:15. [PMID: 34991560 PMCID: PMC8734237 DOI: 10.1186/s12902-021-00924-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2021] [Accepted: 12/21/2021] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND Mitochondrial ribosomal protein S2 (MRPS2) gene mutation, which is related to severe hypoglycemia and lactic acidosis, is rarely reported globally. CASE PRESENTATION We report a case of a new MRPS2 gene mutation in a Chinese girl who presented with hypoglycemia and lactic acidosis. A homozygous C.412C > G variant that could cause complex oxidative phosphorylation deficiency and had not been reported before was identified. The clinical manifestations included recurrent vomiting, hypoglycemia, lactic acidosis, sensorineural hearing loss, and gall bladder calculi. Hypoglycemia and lactic acidosis improved after the administration of sugary liquid and supportive treatments. CONCLUSIONS Recurrent hypoglycemia with lactic acidosis and sensorineural hearing loss should lead to suspicion of mitochondrial defects and the early refinement of genetic tests.
Collapse
Affiliation(s)
- ChangZhi Liu
- Xiangxi Tujia and Miao Autonomous Prefecture People's Hospital, Jishou, China
| | - WeiRan Zhou
- Jinan Children's Hospital (Qilu Children's Hospital of Shandong University), Jinan, China.
| | - QuanE Liu
- Xiangxi Tujia and Miao Autonomous Prefecture People's Hospital, Jishou, China
| | - ZaiXin Peng
- Xiangxi Tujia and Miao Autonomous Prefecture People's Hospital, Jishou, China
| |
Collapse
|
12
|
Wang F, Zhang D, Zhang D, Li P, Gao Y. Mitochondrial Protein Translation: Emerging Roles and Clinical Significance in Disease. Front Cell Dev Biol 2021; 9:675465. [PMID: 34277617 PMCID: PMC8280776 DOI: 10.3389/fcell.2021.675465] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Accepted: 06/09/2021] [Indexed: 12/28/2022] Open
Abstract
Mitochondria are one of the most important organelles in cells. Mitochondria are semi-autonomous organelles with their own genetic system, and can independently replicate, transcribe, and translate mitochondrial DNA. Translation initiation, elongation, termination, and recycling of the ribosome are four stages in the process of mitochondrial protein translation. In this process, mitochondrial protein translation factors and translation activators, mitochondrial RNA, and other regulatory factors regulate mitochondrial protein translation. Mitochondrial protein translation abnormalities are associated with a variety of diseases, including cancer, cardiovascular diseases, and nervous system diseases. Mutation or deletion of various mitochondrial protein translation factors and translation activators leads to abnormal mitochondrial protein translation. Mitochondrial tRNAs and mitochondrial ribosomal proteins are essential players during translation and mutations in genes encoding them represent a large fraction of mitochondrial diseases. Moreover, there is crosstalk between mitochondrial protein translation and cytoplasmic translation, and the imbalance between mitochondrial protein translation and cytoplasmic translation can affect some physiological and pathological processes. This review summarizes the regulation of mitochondrial protein translation factors, mitochondrial ribosomal proteins, mitochondrial tRNAs, and mitochondrial aminoacyl-tRNA synthetases (mt-aaRSs) in the mitochondrial protein translation process and its relationship with diseases. The regulation of mitochondrial protein translation and cytoplasmic translation in multiple diseases is also summarized.
Collapse
Affiliation(s)
- Fei Wang
- Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao, China
| | - Deyu Zhang
- Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao, China
| | - Dejiu Zhang
- Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao, China
| | - Peifeng Li
- Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao, China
| | - Yanyan Gao
- Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao, China.,Key Laboratory of Nuclear Medicine, Ministry of Health, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi, China
| |
Collapse
|
13
|
Alsharhan H, Muraresku C, Ganetzky RD. COXPD9 in an individual from Puerto Rico and literature review. Am J Med Genet A 2021; 185:2519-2525. [PMID: 34008913 DOI: 10.1002/ajmg.a.62344] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 04/28/2021] [Accepted: 05/02/2021] [Indexed: 11/07/2022]
Abstract
Defects of mitoribosome assembly with destabilization of mitochondrial ribosomal proteins and subsequent aberrant mitochondrial translation machinery are one of the emerging categories of human mitochondrial disease. Mitochondrial translation deficiency constitutes a growing cause of combined oxidative phosphorylation deficiency and overall causes a set of clinically heterogeneous multi-systemic diseases. We present here the sixth individual with combined oxidative phosphorylation deficiency-9 (COXPD9) secondary to a likely pathogenic homozygous MRPL3 variant c.571A > C; p.(Thr191Pro). MRPL3 encodes a large mitochondrial ribosome subunit protein, impairing the mitochondrial translation and resulting in multisystem disease. Similar to previously reported individuals, this reported female proband presented with psychomotor retardation, sensorineural hearing loss, hypertrophic cardiomyopathy, failure to thrive, and lactic acidosis. Further, she has additional, previously unreported, features including Leigh syndrome, cataracts, hypotonia, scoliosis, myopathy, exercise intolerance, childhood-onset cardiomyopathy, and microcephaly. This subject is the oldest reported individual with COXPD9. This report also summarizes the clinical and molecular data of the previously reported individuals with COXPD9 to describe the full phenotypic spectrum.
Collapse
Affiliation(s)
- Hind Alsharhan
- Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA.,Division of Human Genetics, Section of Biochemical Genetics, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA.,Department of Pediatrics, Faculty of Medicine, Kuwait University, Kuwait City, Kuwait
| | - Colleen Muraresku
- Division of Human Genetics, Section of Biochemical Genetics, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Rebecca D Ganetzky
- Division of Human Genetics, Section of Biochemical Genetics, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA.,Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| |
Collapse
|
14
|
Human Mitoribosome Biogenesis and Its Emerging Links to Disease. Int J Mol Sci 2021; 22:ijms22083827. [PMID: 33917098 PMCID: PMC8067846 DOI: 10.3390/ijms22083827] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 03/23/2021] [Accepted: 03/24/2021] [Indexed: 12/20/2022] Open
Abstract
Mammalian mitochondrial ribosomes (mitoribosomes) synthesize a small subset of proteins, which are essential components of the oxidative phosphorylation machinery. Therefore, their function is of fundamental importance to cellular metabolism. The assembly of mitoribosomes is a complex process that progresses through numerous maturation and protein-binding events coordinated by the actions of several assembly factors. Dysregulation of mitoribosome production is increasingly recognized as a contributor to metabolic and neurodegenerative diseases. In recent years, mutations in multiple components of the mitoribosome assembly machinery have been associated with a range of human pathologies, highlighting their importance to cell function and health. Here, we provide a review of our current understanding of mitoribosome biogenesis, highlighting the key factors involved in this process and the growing number of mutations in genes encoding mitoribosomal RNAs, proteins, and assembly factors that lead to human disease.
Collapse
|
15
|
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.
Collapse
|
16
|
Horga A, Manole A, Mitchell AL, Bugiardini E, Hargreaves IP, Mowafi W, Bettencourt C, Blakely EL, He L, Polke JM, Woodward CE, Dalla Rosa I, Shah S, Pittman AM, Quinlivan R, Reilly MM, Taylor RW, Holt IJ, Hanna MG, Pitceathly RDS, Spinazzola A, Houlden H. Uniparental isodisomy of chromosome 2 causing MRPL44-related multisystem mitochondrial disease. Mol Biol Rep 2021; 48:2093-2104. [PMID: 33742325 DOI: 10.1007/s11033-021-06188-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Accepted: 01/28/2021] [Indexed: 12/15/2022]
Abstract
Mutations in nuclear-encoded protein subunits of the mitochondrial ribosome are an increasingly recognised cause of oxidative phosphorylation system (OXPHOS) disorders. Among them, mutations in the MRPL44 gene, encoding a structural protein of the large subunit of the mitochondrial ribosome, have been identified in four patients with OXPHOS defects and early-onset hypertrophic cardiomyopathy with or without additional clinical features. A 23-year-old individual with cardiac and skeletal myopathy, neurological involvement, and combined deficiency of OXPHOS complexes in skeletal muscle was clinically and genetically investigated. Analysis of whole-exome sequencing data revealed a homozygous mutation in MRPL44 (c.467 T > G), which was not present in the biological father, and a region of homozygosity involving most of chromosome 2, raising the possibility of uniparental disomy. Short-tandem repeat and genome-wide SNP microarray analyses of the family trio confirmed complete maternal uniparental isodisomy of chromosome 2. Mitochondrial ribosome assembly and mitochondrial translation were assessed in patient derived-fibroblasts. These studies confirmed that c.467 T > G affects the stability or assembly of the large subunit of the mitochondrial ribosome, leading to impaired mitochondrial protein synthesis and decreased levels of multiple OXPHOS components. This study provides evidence of complete maternal uniparental isodisomy of chromosome 2 in a patient with MRPL44-related disease, and confirms that MRLP44 mutations cause a mitochondrial translation defect that may present as a multisystem disorder with neurological involvement.
Collapse
Affiliation(s)
- Alejandro Horga
- MRC Centre for Neuromuscular Diseases, UCL Queen Square Institute of Neurology and the National Hospital for Neurology and Neurosurgery, Queen Square, London, WC1N 3BG, UK.
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology and the National Hospital for Neurology and Neurosurgery, Queen Square, London, WC1N 3BG, UK.
- Neuromuscular Diseases Unit, Department of Neurology, Hospital Clínico San Carlos and Instituto de Investigación Sanitaria San Carlos (IdISSC), 28040, Madrid, Spain.
| | - Andreea Manole
- MRC Centre for Neuromuscular Diseases, UCL Queen Square Institute of Neurology and the National Hospital for Neurology and Neurosurgery, Queen Square, London, WC1N 3BG, UK
- Department of Molecular Neuroscience, UCL Queen Square Institute of Neurology, Queen Square, London, WC1N 3BG, UK
| | - Alice L Mitchell
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, Royal Free Campus, London, NW3 2PF, UK
| | - Enrico Bugiardini
- MRC Centre for Neuromuscular Diseases, UCL Queen Square Institute of Neurology and the National Hospital for Neurology and Neurosurgery, Queen Square, London, WC1N 3BG, UK
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology and the National Hospital for Neurology and Neurosurgery, Queen Square, London, WC1N 3BG, UK
| | - Iain P Hargreaves
- Neurometabolic Unit, the National Hospital for Neurology and Neurosurgery, Queen Square, London, WC1N 3BG, UK
| | - Walied Mowafi
- Neurosciences Department, Calderdale Royal Hospital, Halifax, HX3 0PW, UK
| | - Conceição Bettencourt
- Queen Square Brain Bank for Neurological Disorders, Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, London, WC1N 1PJ, UK
| | - Emma L Blakely
- Institute of Neuroscience, Wellcome Centre for Mitochondrial Research, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
| | - Langping He
- Institute of Neuroscience, Wellcome Centre for Mitochondrial Research, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
| | - James M Polke
- Neurogenetic Unit, the National Hospital for Neurology and Neurosurgery, Queen Square, London, WC1N 3BG, UK
| | - Catherine E Woodward
- Neurogenetic Unit, the National Hospital for Neurology and Neurosurgery, Queen Square, London, WC1N 3BG, UK
| | - Ilaria Dalla Rosa
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, Royal Free Campus, London, NW3 2PF, UK
| | - Sachit Shah
- Lysholm Department of Neuroradiology, the National Hospital for Neurology and Neurosurgery, Queen Square, London, WC1N 3BG, UK
| | - Alan M Pittman
- Department of Molecular Neuroscience, UCL Queen Square Institute of Neurology, Queen Square, London, WC1N 3BG, UK
| | - Ros Quinlivan
- MRC Centre for Neuromuscular Diseases, UCL Queen Square Institute of Neurology and the National Hospital for Neurology and Neurosurgery, Queen Square, London, WC1N 3BG, UK
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology and the National Hospital for Neurology and Neurosurgery, Queen Square, London, WC1N 3BG, UK
| | - Mary M Reilly
- MRC Centre for Neuromuscular Diseases, UCL Queen Square Institute of Neurology and the National Hospital for Neurology and Neurosurgery, Queen Square, London, WC1N 3BG, UK
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology and the National Hospital for Neurology and Neurosurgery, Queen Square, London, WC1N 3BG, UK
| | - Robert W Taylor
- Institute of Neuroscience, Wellcome Centre for Mitochondrial Research, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
| | - Ian J Holt
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, Royal Free Campus, London, NW3 2PF, UK
- Biodonostia Health Research Institute, 20014, San Sebastián, Spain
- Ikerbasque, Basque Foundation for Science, 48013, Bilbao, Spain
| | - Michael G Hanna
- MRC Centre for Neuromuscular Diseases, UCL Queen Square Institute of Neurology and the National Hospital for Neurology and Neurosurgery, Queen Square, London, WC1N 3BG, UK
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology and the National Hospital for Neurology and Neurosurgery, Queen Square, London, WC1N 3BG, UK
| | - Robert D S Pitceathly
- MRC Centre for Neuromuscular Diseases, UCL Queen Square Institute of Neurology and the National Hospital for Neurology and Neurosurgery, Queen Square, London, WC1N 3BG, UK
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology and the National Hospital for Neurology and Neurosurgery, Queen Square, London, WC1N 3BG, UK
| | - Antonella Spinazzola
- MRC Centre for Neuromuscular Diseases, UCL Queen Square Institute of Neurology and the National Hospital for Neurology and Neurosurgery, Queen Square, London, WC1N 3BG, UK
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, Royal Free Campus, London, NW3 2PF, UK
| | - Henry Houlden
- MRC Centre for Neuromuscular Diseases, UCL Queen Square Institute of Neurology and the National Hospital for Neurology and Neurosurgery, Queen Square, London, WC1N 3BG, UK.
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology and the National Hospital for Neurology and Neurosurgery, Queen Square, London, WC1N 3BG, UK.
- Department of Molecular Neuroscience, UCL Queen Square Institute of Neurology, Queen Square, London, WC1N 3BG, UK.
| |
Collapse
|
17
|
Role of GTPases in Driving Mitoribosome Assembly. Trends Cell Biol 2021; 31:284-297. [PMID: 33419649 DOI: 10.1016/j.tcb.2020.12.008] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 12/01/2020] [Accepted: 12/11/2020] [Indexed: 01/08/2023]
Abstract
Mitoribosomes catalyze essential protein synthesis within mitochondria. Mitoribosome biogenesis is assisted by an increasing number of assembly factors, among which guanosine triphosphate hydrolases (GTPases) are the most abundant class. Here, we review recent progress in our understanding of mitoribosome assembly GTPases. We describe their shared and specific features and mechanisms of action, compare them with their bacterial counterparts, and discuss their possible roles in the assembly of small or large mitoribosomal subunits and the formation of the monosome by establishing quality-control checkpoints during these processes. Furthermore, following the recent unification of the nomenclature for the mitoribosomal proteins, we also propose a unified nomenclature for mitoribosome assembly GTPases.
Collapse
|
18
|
Ferrari A, Del'Olio S, Barrientos A. The Diseased Mitoribosome. FEBS Lett 2020; 595:1025-1061. [PMID: 33314036 DOI: 10.1002/1873-3468.14024] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 12/03/2020] [Accepted: 12/06/2020] [Indexed: 12/17/2022]
Abstract
Mitochondria control life and death in eukaryotic cells. Harboring a unique circular genome, a by-product of an ancient endosymbiotic event, mitochondria maintains a specialized and evolutionary divergent protein synthesis machinery, the mitoribosome. Mitoribosome biogenesis depends on elements encoded in both the mitochondrial genome (the RNA components) and the nuclear genome (all ribosomal proteins and assembly factors). Recent cryo-EM structures of mammalian mitoribosomes have illuminated their composition and provided hints regarding their assembly and elusive mitochondrial translation mechanisms. A growing body of literature involves the mitoribosome in inherited primary mitochondrial disorders. Mutations in genes encoding mitoribosomal RNAs, proteins, and assembly factors impede mitoribosome biogenesis, causing protein synthesis defects that lead to respiratory chain failure and mitochondrial disorders such as encephalo- and cardiomyopathy, deafness, neuropathy, and developmental delays. In this article, we review the current fundamental understanding of mitoribosome assembly and function, and the clinical landscape of mitochondrial disorders driven by mutations in mitoribosome components and assembly factors, to portray how basic and clinical studies combined help us better understand both mitochondrial biology and medicine.
Collapse
Affiliation(s)
- Alberto Ferrari
- Department of Neurology, University of Miami Miller School of Medicine, FL, USA
| | - Samuel Del'Olio
- Department of Neurology, University of Miami Miller School of Medicine, FL, USA.,Molecular and Cellular Pharmacology Graduate Program, University of Miami Miller School of Medicine, FL, USA
| | - Antoni Barrientos
- Department of Neurology, University of Miami Miller School of Medicine, FL, USA.,Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, FL, USA
| |
Collapse
|
19
|
Schijvens AM, van de Kar NC, Bootsma-Robroeks CM, Cornelissen EA, van den Heuvel LP, Schreuder MF. Mitochondrial Disease and the Kidney With a Special Focus on CoQ 10 Deficiency. Kidney Int Rep 2020; 5:2146-2159. [PMID: 33305107 PMCID: PMC7710892 DOI: 10.1016/j.ekir.2020.09.044] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Accepted: 09/29/2020] [Indexed: 12/13/2022] Open
Abstract
Mitochondrial cytopathies include a heterogeneous group of diseases that are characterized by impaired oxidative phosphorylation, leading to multi-organ involvement and progressive clinical deterioration. Most mitochondrial cytopathies that cause kidney symptoms are characterized by tubular defects, but glomerular, tubulointerstitial, and cystic diseases have also been described. Mitochondrial cytopathies can result from mitochondrial or nuclear DNA mutations. Early recognition of defects in the coenzyme Q10 (CoQ10) biosynthesis is important, as patients with primary CoQ10 deficiency may be responsive to treatment with oral CoQ10 supplementation, in contrast to most mitochondrial diseases. A literature search was conducted to investigate kidney involvement in genetic mitochondrial cytopathies and to identify mitochondrial and nuclear DNA mutations involved in mitochondrial kidney disease. Furthermore, we identified all reported cases to date with a CoQ10 deficiency with glomerular involvement, including 3 patients with variable renal phenotypes in our clinic. To date, 144 patients from 95 families with a primary CoQ10 deficiency and glomerular involvement have been described based on mutations in PDSS1, PDSS2, COQ2, COQ6, and COQ8B/ADCK4. This review provides an overview of kidney involvement in genetic mitochondrial cytopathies with a special focus on CoQ10 deficiency.
Collapse
Affiliation(s)
- Anne M. Schijvens
- Department of Pediatric Nephrology, Radboud University Medical Center, Radboud Institute for Molecular Life Sciences, Amalia Children’s Hospital, Nijmegen, the Netherlands
| | - Nicole C. van de Kar
- Department of Pediatric Nephrology, Radboud University Medical Center, Radboud Institute for Molecular Life Sciences, Amalia Children’s Hospital, Nijmegen, the Netherlands
| | - Charlotte M. Bootsma-Robroeks
- Department of Pediatric Nephrology, Radboud University Medical Center, Radboud Institute for Molecular Life Sciences, Amalia Children’s Hospital, Nijmegen, the Netherlands
| | - Elisabeth A. Cornelissen
- Department of Pediatric Nephrology, Radboud University Medical Center, Radboud Institute for Molecular Life Sciences, Amalia Children’s Hospital, Nijmegen, the Netherlands
| | - Lambertus P. van den Heuvel
- Department of Pediatric Nephrology, Radboud University Medical Center, Radboud Institute for Molecular Life Sciences, Amalia Children’s Hospital, Nijmegen, the Netherlands
- Department of Development and Regeneration,University Hospital Leuven, Leuven, Belgium
| | - Michiel F. Schreuder
- Department of Pediatric Nephrology, Radboud University Medical Center, Radboud Institute for Molecular Life Sciences, Amalia Children’s Hospital, Nijmegen, the Netherlands
| |
Collapse
|
20
|
İnce B, Altinoz MA, Ayran AC, Cansız A, Altinbaş K, Guloksuz S, Kurt E. Minor Physical Anomalies in Bipolar Disorder. Compr Psychiatry 2020; 103:152206. [PMID: 33099105 DOI: 10.1016/j.comppsych.2020.152206] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 06/07/2020] [Accepted: 09/01/2020] [Indexed: 11/26/2022] Open
Abstract
OBJECTIVE High-arched palate is more frequent in schizophrenia and bipolar disorder (BD). Upto 40% of patients develop schizophrenia in 22q11.2 Deletion Syndrome manifested with cleft lip and palate, which originate from the first pharyngeal arch in embryo. The auricle also originates from the dorsal ends of the first and second pharyngeal arches; hence, we aimed to determine the associations between auricular anomalies and BD. METHODS We screened for 36 minor physical anomalies of the auricle in 146 patients with BD. RESULTS 7 out of the of 36 assessed anomalies highly differed between healthy subjects and BD patients. A regression model including the differing anomalies predicted healthy subjects and BD-patients by 78.8% and 68.5%, respectively. CONCLUSIONS Assessing minor anomalies in psychiatric disorders may help to discover novel pathogenesis pathways and even new endophenotypes.
Collapse
Affiliation(s)
- Bahri İnce
- Department of Psychiatry, Bakirkoy Research and Training Hospital for Psychiatry Neurology and Neurosurgery, Istanbul, Turkey
| | - Meric A Altinoz
- Department of Psychiatry and Psychology, Maastricht University Medical Centre, Maastricht, the Netherlands; Department of Medical Biochemistry, Acibadem University, Istanbul, Turkey.
| | - Aylin Can Ayran
- Department of Psychiatry, Kilis State Hospital, Kilis, Turkey
| | - Alparslan Cansız
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
| | - Kürşat Altinbaş
- Department of Psychiatry, Faculty of Medicine, Selçuk University, Konya, Turkey
| | - Sinan Guloksuz
- Department of Psychiatry and Psychology, Maastricht University Medical Centre, Maastricht, the Netherlands; Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
| | - Erhan Kurt
- Department of Psychiatry, Bakirkoy Research and Training Hospital for Psychiatry Neurology and Neurosurgery, Istanbul, Turkey
| |
Collapse
|
21
|
Di Nottia M, Marchese M, Verrigni D, Mutti CD, Torraco A, Oliva R, Fernandez-Vizarra E, Morani F, Trani G, Rizza T, Ghezzi D, Ardissone A, Nesti C, Vasco G, Zeviani M, Minczuk M, Bertini E, Santorelli FM, Carrozzo R. A homozygous MRPL24 mutation causes a complex movement disorder and affects the mitoribosome assembly. Neurobiol Dis 2020; 141:104880. [PMID: 32344152 DOI: 10.1016/j.nbd.2020.104880] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Revised: 03/04/2020] [Accepted: 04/23/2020] [Indexed: 01/31/2023] Open
Abstract
Mitochondrial ribosomal protein large 24 (MRPL24) is 1 of the 82 protein components of mitochondrial ribosomes, playing an essential role in the mitochondrial translation process. We report here on a baby girl with cerebellar atrophy, choreoathetosis of limbs and face, intellectual disability and a combined defect of complexes I and IV in muscle biopsy, caused by a homozygous missense mutation identified in MRPL24. The variant predicts a Leu91Pro substitution at an evolutionarily conserved site. Using human mutant cells and the zebrafish model, we demonstrated the pathological role of the identified variant. In fact, in fibroblasts we observed a significant reduction of MRPL24 protein and of mitochondrial respiratory chain complex I and IV subunits, as well a markedly reduced synthesis of the mtDNA-encoded peptides. In zebrafish we demonstrated that the orthologue gene is expressed in metabolically active tissues, and that gene knockdown induced locomotion impairment, structural defects and low ATP production. The motor phenotype was complemented by human WT but not mutant cRNA. Moreover, sucrose density gradient fractionation showed perturbed assembly of large subunit mitoribosomal proteins, suggesting that the mutation leads to a conformational change in MRPL24, which is expected to cause an aberrant interaction of the protein with other components of the 39S mitoribosomal subunit.
Collapse
Affiliation(s)
- Michela Di Nottia
- Unit of Muscular and Neurodegenerative Disorders, Laboratory of Molecular Medicine, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Maria Marchese
- Molecular Medicine & Neurogenetics, IRCCS Fondazione Stella Maris, Pisa, Italy
| | - Daniela Verrigni
- Unit of Muscular and Neurodegenerative Disorders, Laboratory of Molecular Medicine, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | | | - Alessandra Torraco
- Unit of Muscular and Neurodegenerative Disorders, Laboratory of Molecular Medicine, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Romina Oliva
- Department of Sciences and Technologies, University Parthenope of Naples, Naples, Italy
| | | | - Federica Morani
- Molecular Medicine & Neurogenetics, IRCCS Fondazione Stella Maris, Pisa, Italy
| | - Giulia Trani
- Unit of Muscular and Neurodegenerative Disorders, Laboratory of Molecular Medicine, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Teresa Rizza
- Unit of Muscular and Neurodegenerative Disorders, Laboratory of Molecular Medicine, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Daniele Ghezzi
- Unit of Medical Genetics and Neurogenetics, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy; Department of Pathophysiology and Transplantation, University of Milan, Milan, Italy
| | - Anna Ardissone
- Child Neurology Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy; Department of Molecular and Translational Medicine DIMET, University of Milan-Bicocca, Milan, Italy
| | - Claudia Nesti
- Molecular Medicine & Neurogenetics, IRCCS Fondazione Stella Maris, Pisa, Italy
| | - Gessica Vasco
- Department of Neurosciences, IRCCS Bambino Gesù Children Hospital, Rome, Italy
| | - Massimo Zeviani
- MRC Mitochondrial Biology Unit, University of Cambridge, Cambridge, UK
| | - Michal Minczuk
- MRC Mitochondrial Biology Unit, University of Cambridge, Cambridge, UK
| | - Enrico Bertini
- Unit of Muscular and Neurodegenerative Disorders, Laboratory of Molecular Medicine, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | | | - Rosalba Carrozzo
- Unit of Muscular and Neurodegenerative Disorders, Laboratory of Molecular Medicine, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy.
| |
Collapse
|
22
|
Abstract
Mitochondrial disease presenting in childhood is characterized by clinical, biochemical and genetic complexity. Some children are affected by canonical syndromes, but the majority have nonclassical multisystemic disease presentations involving virtually any organ in the body. Each child has a unique constellation of clinical features and disease trajectory, leading to enormous challenges in diagnosis and management of these heterogeneous disorders. This review discusses the classical mitochondrial syndromes presenting most frequently in childhood and then presents an organ-based perspective including systems less frequently linked to mitochondrial disease, such as skin and hair abnormalities and immune dysfunction. An approach to diagnosis is then presented, encompassing clinical evaluation and biochemical, neuroimaging and genetic investigations, and emphasizing the problem of phenocopies. The impact of next-generation sequencing is discussed, together with the importance of functional validation of novel genetic variants never previously linked to mitochondrial disease. The review concludes with a brief discussion of currently available and emerging therapies. The field of mitochondrial medicine has made enormous strides in the last 30 years, with approaching 400 different genes across two genomes now linked to primary mitochondrial disease. However, many important questions remain unanswered, including the reasons for tissue specificity and variability of clinical presentation of individuals sharing identical gene defects, and a lack of disease-modifying therapies and biomarkers to monitor disease progression and/or response to treatment.
Collapse
Affiliation(s)
- S Rahman
- Mitochondrial Research Group, UCL Great Ormond Street Institute of Child Health, London, UK
| |
Collapse
|
23
|
Salminen TS, Vale PF. Drosophila as a Model System to Investigate the Effects of Mitochondrial Variation on Innate Immunity. Front Immunol 2020; 11:521. [PMID: 32269576 PMCID: PMC7109263 DOI: 10.3389/fimmu.2020.00521] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 03/06/2020] [Indexed: 12/14/2022] Open
Abstract
Understanding why the response to infection varies between individuals remains one of the major challenges in immunology and infection biology. A substantial proportion of this heterogeneity can be explained by individual genetic differences which result in variable immune responses, and there are many examples of polymorphisms in nuclear-encoded genes that alter immunocompetence. However, how immunity is affected by genetic polymorphism in an additional genome, inherited maternally inside mitochondria (mtDNA), has been relatively understudied. Mitochondria are increasingly recognized as important mediators of innate immune responses, not only because they are the main source of energy required for costly immune responses, but also because by-products of mitochondrial metabolism, such as reactive oxygen species (ROS), may have direct microbicidal action. Yet, it is currently unclear how naturally occurring variation in mtDNA contributes to heterogeneity in infection outcomes. In this review article, we describe potential sources of variation in mitochondrial function that may arise due to mutations in vital nuclear and mitochondrial components of energy production or due to a disruption in mito-nuclear crosstalk. We then highlight how these changes in mitochondrial function can impact immune responses, focusing on their effects on ATP- and ROS-generating pathways, as well as immune signaling. Finally, we outline how being a powerful and genetically tractable model of infection, immunity and mitochondrial genetics makes the fruit fly Drosophila melanogaster ideally suited to dissect mitochondrial effects on innate immune responses to infection.
Collapse
Affiliation(s)
- Tiina S. Salminen
- School of Biological Sciences, Institute of Evolutionary Biology, The University of Edinburgh, Edinburgh, United Kingdom
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - Pedro F. Vale
- School of Biological Sciences, Institute of Evolutionary Biology, The University of Edinburgh, Edinburgh, United Kingdom
| |
Collapse
|
24
|
Thompson K, Collier JJ, Glasgow RIC, Robertson FM, Pyle A, Blakely EL, Alston CL, Oláhová M, McFarland R, Taylor RW. Recent advances in understanding the molecular genetic basis of mitochondrial disease. J Inherit Metab Dis 2020; 43:36-50. [PMID: 31021000 PMCID: PMC7041634 DOI: 10.1002/jimd.12104] [Citation(s) in RCA: 94] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Revised: 04/03/2019] [Accepted: 04/24/2019] [Indexed: 12/22/2022]
Abstract
Mitochondrial disease is hugely diverse with respect to associated clinical presentations and underlying genetic causes, with pathogenic variants in over 300 disease genes currently described. Approximately half of these have been discovered in the last decade due to the increasingly widespread application of next generation sequencing technologies, in particular unbiased, whole exome-and latterly, whole genome sequencing. These technologies allow more genetic data to be collected from patients with mitochondrial disorders, continually improving the diagnostic success rate in a clinical setting. Despite these significant advances, some patients still remain without a definitive genetic diagnosis. Large datasets containing many variants of unknown significance have become a major challenge with next generation sequencing strategies and these require significant functional validation to confirm pathogenicity. This interface between diagnostics and research is critical in continuing to expand the list of known pathogenic variants and concomitantly enhance our knowledge of mitochondrial biology. The increasing use of whole exome sequencing, whole genome sequencing and other "omics" techniques such as transcriptomics and proteomics will generate even more data and allow further interrogation and validation of genetic causes, including those outside of coding regions. This will improve diagnostic yields still further and emphasizes the integral role that functional assessment of variant causality plays in this process-the overarching focus of this review.
Collapse
Affiliation(s)
- Kyle Thompson
- Wellcome Centre for Mitochondrial Research, Institute of NeuroscienceNewcastle UniversityNewcastle upon TyneUK
| | - Jack J. Collier
- Wellcome Centre for Mitochondrial Research, Institute of NeuroscienceNewcastle UniversityNewcastle upon TyneUK
| | - Ruth I. C. Glasgow
- Wellcome Centre for Mitochondrial Research, Institute of NeuroscienceNewcastle UniversityNewcastle upon TyneUK
| | - Fiona M. Robertson
- Wellcome Centre for Mitochondrial Research, Institute of NeuroscienceNewcastle UniversityNewcastle upon TyneUK
| | - Angela Pyle
- Wellcome Centre for Mitochondrial Research, Institute of Genetic MedicineNewcastle UniversityNewcastle upon TyneUK
| | - Emma L. Blakely
- Wellcome Centre for Mitochondrial Research, Institute of NeuroscienceNewcastle UniversityNewcastle upon TyneUK
- NHS Highly Specialised Mitochondrial Diagnostic LaboratoryNewcastle upon Tyne Hospitals NHS Foundation TrustNewcastle upon TyneUK
| | - Charlotte L. Alston
- Wellcome Centre for Mitochondrial Research, Institute of NeuroscienceNewcastle UniversityNewcastle upon TyneUK
- NHS Highly Specialised Mitochondrial Diagnostic LaboratoryNewcastle upon Tyne Hospitals NHS Foundation TrustNewcastle upon TyneUK
| | - Monika Oláhová
- Wellcome Centre for Mitochondrial Research, Institute of NeuroscienceNewcastle UniversityNewcastle upon TyneUK
| | - Robert McFarland
- Wellcome Centre for Mitochondrial Research, Institute of NeuroscienceNewcastle UniversityNewcastle upon TyneUK
| | - Robert W. Taylor
- Wellcome Centre for Mitochondrial Research, Institute of NeuroscienceNewcastle UniversityNewcastle upon TyneUK
- NHS Highly Specialised Mitochondrial Diagnostic LaboratoryNewcastle upon Tyne Hospitals NHS Foundation TrustNewcastle upon TyneUK
| |
Collapse
|
25
|
Tiosano D, Mears JA, Buchner DA. Mitochondrial Dysfunction in Primary Ovarian Insufficiency. Endocrinology 2019; 160:2353-2366. [PMID: 31393557 PMCID: PMC6760336 DOI: 10.1210/en.2019-00441] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Accepted: 08/01/2019] [Indexed: 12/14/2022]
Abstract
Primary ovarian insufficiency (POI) is defined by the loss or dysfunction of ovarian follicles associated with amenorrhea before the age of 40. Symptoms include hot flashes, sleep disturbances, and depression, as well as reduced fertility and increased long-term risk of cardiovascular disease. POI occurs in ∼1% to 2% of women, although the etiology of most cases remains unexplained. Approximately 10% to 20% of POI cases are due to mutations in a single gene or a chromosomal abnormality, which has provided considerable molecular insight into the biological underpinnings of POI. Many of the genes for which mutations have been associated with POI, either isolated or syndromic cases, function within mitochondria, including MRPS22, POLG, TWNK, LARS2, HARS2, AARS2, CLPP, and LRPPRC. Collectively, these genes play roles in mitochondrial DNA replication, gene expression, and protein synthesis and degradation. Although mutations in these genes clearly implicate mitochondrial dysfunction in rare cases of POI, data are scant as to whether these genes in particular, and mitochondrial dysfunction in general, contribute to most POI cases that lack a known etiology. Further studies are needed to better elucidate the contribution of mitochondria to POI and determine whether there is a common molecular defect in mitochondrial function that distinguishes mitochondria-related genes that when mutated cause POI vs those that do not. Nonetheless, the clear implication of mitochondrial dysfunction in POI suggests that manipulation of mitochondrial function represents an important therapeutic target for the treatment or prevention of POI.
Collapse
Affiliation(s)
- Dov Tiosano
- Division of Pediatric Endocrinology, Ruth Rappaport Children’s Hospital, Rambam Medical Center, Haifa, Israel
- Rappaport Family Faculty of Medicine, Technion—Israel Institute of Technology, Haifa, Israel
- Correspondence: David A. Buchner, PhD, Case Western Reserve University School of Medicine, 10900 Euclid Avenue, Cleveland, Ohio 44106. E-mail: ; or Dov Tiosano, MD, Division of Pediatric Endocrinology, Ruth Rappaport Children’s Hospital, Rambam Medical Center, HaAliya HaShniya Street 8, Haifa 3109601, Israel. E-mail:
| | - Jason A Mears
- Center for Mitochondrial Diseases, Case Western Reserve University, Cleveland, Ohio
- Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio
| | - David A Buchner
- Department of Genetics and Genome Sciences, Case Western Reserve University, Cleveland, Ohio
- Department of Biochemistry, Case Western Reserve University, Cleveland, Ohio
- Research Institute for Children’s Health, Case Western Reserve University, Cleveland, Ohio
- Correspondence: David A. Buchner, PhD, Case Western Reserve University School of Medicine, 10900 Euclid Avenue, Cleveland, Ohio 44106. E-mail: ; or Dov Tiosano, MD, Division of Pediatric Endocrinology, Ruth Rappaport Children’s Hospital, Rambam Medical Center, HaAliya HaShniya Street 8, Haifa 3109601, Israel. E-mail:
| |
Collapse
|
26
|
Lethal Interaction of Nuclear and Mitochondrial Genotypes in Drosophila melanogaster. G3-GENES GENOMES GENETICS 2019; 9:2225-2234. [PMID: 31076384 PMCID: PMC6643882 DOI: 10.1534/g3.119.400315] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Drosophilamelanogaster, like most animal species, displays considerable genetic variation in both nuclear and mitochondrial DNA (mtDNA). Here we tested whether any of four natural mtDNA variants was able to modify the effect of the phenotypically mild, nuclear tko25t mutation, affecting mitochondrial protein synthesis. When combined with tko25t, the mtDNA from wild strain KSA2 produced pupal lethality, accompanied by the presence of melanotic nodules in L3 larvae. KSA2 mtDNA, which carries a substitution at a conserved residue of cytochrome b that is predicted to be involved in subunit interactions within respiratory complex III, conferred drastically decreased respiratory capacity and complex III activity in the tko25t but not a wild-type nuclear background. The complex III inhibitor antimycin A was able to phenocopy effects of the tko25t mutation in the KSA2 mtDNA background. This is the first report of a lethal, nuclear-mitochondrial interaction within a metazoan species, representing a paradigm for understanding genetic interactions between nuclear and mitochondrial genotype relevant to human health and disease.
Collapse
|
27
|
Jackson CB, Huemer M, Bolognini R, Martin F, Szinnai G, Donner BC, Richter U, Battersby BJ, Nuoffer JM, Suomalainen A, Schaller A. A variant in MRPS14 (uS14m) causes perinatal hypertrophic cardiomyopathy with neonatal lactic acidosis, growth retardation, dysmorphic features and neurological involvement. Hum Mol Genet 2019; 28:639-649. [PMID: 30358850 DOI: 10.1093/hmg/ddy374] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Accepted: 10/16/2018] [Indexed: 11/13/2022] Open
Abstract
Dysfunction of mitochondrial translation is an increasingly important molecular cause of human disease, but structural defects of mitochondrial ribosomal subunits are rare. We used next-generation sequencing to identify a homozygous variant in the mitochondrial small ribosomal protein 14 (MRPS14, uS14m) in a patient manifesting with perinatal hypertrophic cardiomyopathy, growth retardation, muscle hypotonia, elevated lactate, dysmorphy and mental retardation. In skeletal muscle and fibroblasts from the patient, there was biochemical deficiency in complex IV of the respiratory chain. In fibroblasts, mitochondrial translation was impaired, and ectopic expression of a wild-type MRPS14 cDNA functionally complemented this defect. Surprisingly, the mutant uS14m was stable and did not affect assembly of the small ribosomal subunit. Instead, structural modeling of the uS14m mutation predicted a disruption to the ribosomal mRNA channel.Collectively, our data demonstrate pathogenic mutations in MRPS14 can manifest as a perinatal-onset mitochondrial hypertrophic cardiomyopathy with a novel molecular pathogenic mechanism that impairs the function of mitochondrial ribosomes during translation elongation or mitochondrial mRNA recruitment rather than assembly.
Collapse
Affiliation(s)
- Christopher B Jackson
- Research Programs Unit, Molecular Neurology, Biomedicum Helsinki, University of Helsinki, Helsinki FIN, Finland
| | - Martina Huemer
- Division of Metabolism and Children's Research Center, University Children's Hospital Zürich, Zürich CH, Switzerland.,University Children's Hospital Basel, University of Basel, Switzerland
| | - Ramona Bolognini
- Division of Human Genetics, Department of Pediatrics, Inselspital, Bern University Hospital, University of Bern, Bern CH, Switzerland
| | - Franck Martin
- CNRS, Architecture et Réactivité de l'ARN, Université de Strasbourg, UPR 9002, Strasbourg F, France
| | - Gabor Szinnai
- University Children's Hospital Basel, University of Basel, Switzerland.,Division of Pediatric Endocrinology, University Children's Hospital Basel, Basel CH, Switzerland
| | - Birgit C Donner
- Division of Cardiology, University of Basel, Basel CH, Switzerland
| | - Uwe Richter
- Institute of Biotechnology, University of Helsinki, Helsinki, FIN, Finland
| | | | - Jean-Marc Nuoffer
- Institute of Clinical Chemistry, University of Bern, Inselspital, Bern CH, Switzerland.,Division of Endocrinology Diabetology and Metabolism, University Children's Hospital, University of Bern, Bern CH, Switzerland
| | - Anu Suomalainen
- Research Programs Unit, Molecular Neurology, Biomedicum Helsinki, University of Helsinki, Helsinki FIN, Finland.,Neuroscience Center, University of Helsinki, Helsinki FIN, Finland
| | - André Schaller
- Division of Human Genetics, Department of Pediatrics, Inselspital, Bern University Hospital, University of Bern, Bern CH, Switzerland
| |
Collapse
|
28
|
Kinetics and Mechanism of Mammalian Mitochondrial Ribosome Assembly. Cell Rep 2019; 22:1935-1944. [PMID: 29444443 DOI: 10.1016/j.celrep.2018.01.066] [Citation(s) in RCA: 78] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Revised: 11/01/2017] [Accepted: 01/22/2018] [Indexed: 01/08/2023] Open
Abstract
Mammalian mtDNA encodes only 13 proteins, all essential components of respiratory complexes, synthesized by mitochondrial ribosomes. Mitoribosomes contain greatly truncated RNAs transcribed from mtDNA, including a structural tRNA in place of 5S RNA as a scaffold for binding 82 nucleus-encoded proteins, mitoribosomal proteins (MRPs). Cryoelectron microscopy (cryo-EM) studies have determined the structure of the mitoribosome, but its mechanism of assembly is unknown. Our SILAC pulse-labeling experiments determine the rates of mitochondrial import of MRPs and their assembly into intact mitoribosomes, providing a basis for distinguishing MRPs that bind at early and late stages in mitoribosome assembly to generate a working model for mitoribosome assembly. Mitoribosome assembly is a slow process initiated at the mtDNA nucleoid driven by excess synthesis of individual MRPs. MRPs that are tightly associated in the structure frequently join the complex in a coordinated manner. Clinically significant MRP mutations reported to date affect proteins that bind early on during assembly.
Collapse
|
29
|
Farre-Garros R, Lee JY, Natanek SA, Connolly M, Sayer AA, Patel H, Cooper C, Polkey MI, Kemp PR. Quadriceps miR-542-3p and -5p are elevated in COPD and reduce function by inhibiting ribosomal and protein synthesis. J Appl Physiol (1985) 2019; 126:1514-1524. [PMID: 30676868 PMCID: PMC6551227 DOI: 10.1152/japplphysiol.00882.2018] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Revised: 01/04/2019] [Accepted: 01/21/2019] [Indexed: 01/07/2023] Open
Abstract
Reduced physical performance reduces quality of life in patients with chronic obstructive pulmonary disease (COPD). Impaired physical performance is, in part, a consequence of reduced muscle mass and function, which is accompanied by mitochondrial dysfunction. We recently showed that miR-542-3p and miR-542-5p were elevated in a small cohort of COPD patients and more markedly in critical care patients. In mice, these microRNAs (miRNAs) promoted mitochondrial dysfunction suggesting that they would affect physical performance in patients with COPD, but we did not explore the association of these miRNAs with disease severity or physical performance further. We therefore quantified miR-542-3p/5p and mitochondrial rRNA expression in RNA extracted from quadriceps muscle of patients with COPD and determined their association with physical performance. As miR-542-3p inhibits ribosomal protein synthesis its ability to inhibit protein synthesis was also determined in vitro. Both miR-542-3p expression and -5p expression were elevated in patients with COPD (5-fold P < 0.001) and the degree of elevation associated with impaired lung function (transfer capacity of the lung for CO in % and forced expiratory volume in 1 s in %) and physical performance (6-min walk distance in %). In COPD patients, the ratio of 12S rRNA to 16S rRNA was suppressed suggesting mitochondrial ribosomal stress and mitochondrial dysfunction and miR-542-3p/5p expression was inversely associated with mitochondrial gene expression and positively associated with p53 activity. miR-542-3p suppressed RPS23 expression and maximal protein synthesis in vitro. Our data show that miR-542-3p and -5p expression is elevated in COPD patients and may suppress physical performance at least in part by inhibiting mitochondrial and cytoplasmic ribosome synthesis and suppressing protein synthesis. NEW & NOTEWORTHY miR-542-3p and -5p are elevated in the quadriceps muscle of patients with chronic obstructive pulmonary disease (COPD) in proportion to the severity of their lung disease. These microRNAs inhibit mitochondrial and cytoplasmic protein synthesis suggesting that they contribute to impaired exercise performance in COPD.
Collapse
Affiliation(s)
- Roser Farre-Garros
- Molecular Medicine Section, National Heart and Lung Institute, Imperial College, South Kensington Campus, London , United Kingdom
| | - Jen Y Lee
- Molecular Medicine Section, National Heart and Lung Institute, Imperial College, South Kensington Campus, London , United Kingdom
| | - S Amanda Natanek
- Molecular Medicine Section, National Heart and Lung Institute, Imperial College, South Kensington Campus, London , United Kingdom
| | - Martin Connolly
- Molecular Medicine Section, National Heart and Lung Institute, Imperial College, South Kensington Campus, London , United Kingdom
| | - Avan A Sayer
- Medical Research Council Lifecourse Epidemiology Unit, University of Southampton, Southampton General Hospital , Southampton , United Kingdom
- Academic Geriatric Medicine, Faculty of Medicine, University of Southampton , Southampton , United Kingdom
- Ageing Geriatrics and Epidemiology Research Group, Institute of Neuroscience, Faculty of Medical Sciences, Newcastle University , Newcastle upon Tyne , United Kingdom
- National Institute for Health Research Newcastle Biomedical Research Centre, Newcastle upon Tyne Hospitals National Health Service Foundation Trust and Newcastle University , Newcastle upon Tyne , United Kingdom
| | - Harnish Patel
- Medical Research Council Lifecourse Epidemiology Unit, University of Southampton, Southampton General Hospital , Southampton , United Kingdom
- Academic Geriatric Medicine, Faculty of Medicine, University of Southampton , Southampton , United Kingdom
| | - Cyrus Cooper
- Medical Research Council Lifecourse Epidemiology Unit, University of Southampton, Southampton General Hospital , Southampton , United Kingdom
| | - Michael I Polkey
- National Institute for Health Research Respiratory Biomedical Research Unit at Royal Brompton and Harefield National Health Service Foundation Trust and Imperial College , London , United Kingdom
| | - Paul R Kemp
- Molecular Medicine Section, National Heart and Lung Institute, Imperial College, South Kensington Campus, London , United Kingdom
| |
Collapse
|
30
|
Bugiardini E, Mitchell AL, Rosa ID, Horning-Do HT, Pitmann AM, Poole OV, Holton JL, Shah S, Woodward C, Hargreaves I, Quinlivan R, Amunts A, Wiesner RJ, Houlden H, Holt IJ, Hanna MG, Pitceathly RDS, Spinazzola A. MRPS25 mutations impair mitochondrial translation and cause encephalomyopathy. Hum Mol Genet 2019; 28:2711-2719. [PMID: 31039582 PMCID: PMC6687946 DOI: 10.1093/hmg/ddz093] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2019] [Revised: 04/25/2019] [Accepted: 04/25/2019] [Indexed: 12/22/2022] Open
Abstract
Mitochondrial disorders are clinically and genetically heterogeneous and are associated with a variety of disease mechanisms. Defects of mitochondrial protein synthesis account for the largest subgroup of disorders manifesting with impaired respiratory chain capacity; yet, only a few have been linked to dysfunction in the protein components of the mitochondrial ribosomes. Here, we report a subject presenting with dyskinetic cerebral palsy and partial agenesis of the corpus callosum, while histochemical and biochemical analyses of skeletal muscle revealed signs of mitochondrial myopathy. Using exome sequencing, we identified a homozygous variant c.215C>T in MRPS25, which encodes for a structural component of the 28S small subunit of the mitochondrial ribosome (mS25). The variant segregated with the disease and substitutes a highly conserved proline residue with leucine (p.P72L) that, based on the high-resolution structure of the 28S ribosome, is predicted to compromise inter-protein contacts and destabilize the small subunit. Concordant with the in silico analysis, patient’s fibroblasts showed decreased levels of MRPS25 and other components of the 28S subunit. Moreover, assembled 28S subunits were scarce in the fibroblasts with mutant mS25 leading to impaired mitochondrial translation and decreased levels of multiple respiratory chain subunits. Crucially, these abnormalities were rescued by transgenic expression of wild-type MRPS25 in the mutant fibroblasts. Collectively, our data demonstrate the pathogenicity of the p.P72L variant and identify MRPS25 mutations as a new cause of mitochondrial translation defect.
Collapse
Affiliation(s)
- Enrico Bugiardini
- MRC Centre for Neuromuscular Diseases, UCL Queen Square Institute of Neurology and National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, Queen Square, London WC1N 3BG, UK
| | - Alice L Mitchell
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, Royal Free Campus, London NW3 2PF, UK
| | - Ilaria Dalla Rosa
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, Royal Free Campus, London NW3 2PF, UK
| | - Hue-Tran Horning-Do
- Center for Physiology and Pathophysiology, Institute of Vegetative Physiology, Medical Faculty, University of Köln, 50931 Köln, Germany
| | - Alan M Pitmann
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, Queen Square, London WC1N 3BG, UK
| | - Olivia V Poole
- MRC Centre for Neuromuscular Diseases, UCL Queen Square Institute of Neurology and National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, Queen Square, London WC1N 3BG, UK
| | - Janice L Holton
- MRC Centre for Neuromuscular Diseases, UCL Queen Square Institute of Neurology and National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
| | - Sachit Shah
- MRC Centre for Neuromuscular Diseases, UCL Queen Square Institute of Neurology and National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
| | - Cathy Woodward
- Neurogenetic Unit, National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
| | - Iain Hargreaves
- Neurometabolic Unit, National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
| | - Rosaline Quinlivan
- MRC Centre for Neuromuscular Diseases, UCL Queen Square Institute of Neurology and National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
| | - Alexey Amunts
- Science for Life Laboratory, Department of Biochemistry and Biophysics, Stockholm University, 17165 Solna, Sweden
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, 17177 Stockholm, Sweden
| | - Rudolf J Wiesner
- Center for Physiology and Pathophysiology, Institute of Vegetative Physiology, Medical Faculty, University of Köln, 50931 Köln, Germany
| | - Henry Houlden
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, Queen Square, London WC1N 3BG, UK
| | - Ian J Holt
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, Royal Free Campus, London NW3 2PF, UK
- Biodonostia Health Research Institute, 20014 San Sebastián, Spain
- IKERBASQUE, Basque Foundation for Science, 48013 Bilbao, Spain
- CIBERNED (Center for Networked Biomedical Research on Neurodegenerative Diseases, Ministry of Economy and Competitiveness, Institute Carlos III), Madrid, Spain
| | - Michael G Hanna
- MRC Centre for Neuromuscular Diseases, UCL Queen Square Institute of Neurology and National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, Queen Square, London WC1N 3BG, UK
| | - Robert D S Pitceathly
- MRC Centre for Neuromuscular Diseases, UCL Queen Square Institute of Neurology and National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, Queen Square, London WC1N 3BG, UK
| | - Antonella Spinazzola
- MRC Centre for Neuromuscular Diseases, UCL Queen Square Institute of Neurology and National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, Royal Free Campus, London NW3 2PF, UK
| |
Collapse
|
31
|
Bertini V, Valetto A, Baldinotti F, Azzarà A, Cambi F, Toschi B, Giacomina A, Gatti GL, Gana S, Caligo MA, Bertelloni S. Blepharophimosis, Ptosis, Epicanthus Inversus Syndrome: New Report with a 197-kb Deletion Upstream of FOXL2 and Review of the Literature. Mol Syndromol 2019; 10:147-153. [PMID: 31191203 DOI: 10.1159/000497092] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/17/2018] [Indexed: 11/19/2022] Open
Abstract
Blepharophimosis, ptosis, and epicanthus inversus syndrome (BPES) is due to heterozygous FOXL2 intragenic mutations in about 70% of the patients, whereas total or partial gene deletions account for a minority of cases. Alteration of FOXL2 regulatory elements has been rarely described in patients with BPES. In this study, a prepubertal girl with BPES due to a 197-kb de novo deletion of the regulatory elements upstream of FOXL2 is reported. This girl presented with additional clinical features such as a soft cleft palate and microcephaly; thus, this copy number variant might have other somatic effects. The present deletion encompasses 2 coding genes (MRPS22 and COPB2), whose homozygous mutations have been associated with microcephaly. In our case, the sequences of the non-deleted allele were normal, ruling out a compound genetic defect. Normal levels of new biomarkers of ovarian reserve (anti-müllerian hormone, inhibin B) likely indicate an early diagnosis of type 2 BPES, but an evolutive gonadal damage will be excluded only by long-term follow-up. Additional reports of microdeletions upstream of FOXL2 are needed to better define the underlying genetic mechanism and the related phenotypic spectrum; the ability of the new hormonal markers to predict ovarian function in adolescence and adulthood should be confirmed.
Collapse
Affiliation(s)
- Veronica Bertini
- SOD Citogenetica, Azienda Ospedaliero-Universitaria Pisana, Pisa, Italy
| | - Angelo Valetto
- SOD Citogenetica, Azienda Ospedaliero-Universitaria Pisana, Pisa, Italy
| | - Fulvia Baldinotti
- SOD Genetica Molecolare, Azienda Ospedaliero-Universitaria Pisana, Pisa, Italy
| | - Alessia Azzarà
- SOD Citogenetica, Azienda Ospedaliero-Universitaria Pisana, Pisa, Italy
| | - Francesca Cambi
- SOD Citogenetica, Azienda Ospedaliero-Universitaria Pisana, Pisa, Italy
| | - Benedetta Toschi
- Sezione Genetica Medica, Medicina Interna 1, Azienda Ospedaliero-Universitaria Pisana, Pisa, Italy
| | | | - Gian L Gatti
- U.O. Chirurgia Plastica, Azienda Ospedaliero-Universitaria Pisana, Pisa, Italy
| | - Simone Gana
- Sezione Genetica Medica, Medicina Interna 1, Azienda Ospedaliero-Universitaria Pisana, Pisa, Italy
| | - Maria A Caligo
- SOD Genetica Molecolare, Azienda Ospedaliero-Universitaria Pisana, Pisa, Italy
| | - Silvano Bertelloni
- Pediatric Division, Department of Obstetrics, Gynecology and Pediatrics, Azienda Ospedaliero-Universitaria Pisana, Pisa, Italy
| |
Collapse
|
32
|
Chen A, Tiosano D, Guran T, Baris HN, Bayram Y, Mory A, Shapiro-Kulnane L, Hodges CA, Akdemir ZC, Turan S, Jhangiani SN, van den Akker F, Hoppel CL, Salz HK, Lupski JR, Buchner DA. Mutations in the mitochondrial ribosomal protein MRPS22 lead to primary ovarian insufficiency. Hum Mol Genet 2019; 27:1913-1926. [PMID: 29566152 DOI: 10.1093/hmg/ddy098] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Accepted: 03/14/2018] [Indexed: 11/12/2022] Open
Abstract
Primary ovarian insufficiency (POI) is characterized by amenorrhea and loss or dysfunction of ovarian follicles prior to the age of 40. POI has been associated with autosomal recessive mutations in genes involving hormonal signaling and folliculogenesis, however, the genetic etiology of POI most often remains unknown. Here we report MRPS22 homozygous missense variants c.404G>A (p.R135Q) and c.605G>A (p.R202H) identified in four females from two independent consanguineous families as a novel genetic cause of POI in adolescents. Both missense mutations identified in MRPS22 are rare, occurred in highly evolutionarily conserved residues, and are predicted to be deleterious to protein function. In contrast to prior reports of mutations in MRPS22 associated with severe mitochondrial disease, the POI phenotype is far less severe. Consistent with this genotype-phenotype correlation, mitochondrial defects in oxidative phosphorylation or rRNA levels were not detected in fibroblasts derived from the POI patients, suggesting a non-bioenergetic or tissue-specific mitochondrial defect. Furthermore, we demonstrate in a Drosophila model that mRpS22 deficiency specifically in somatic cells of the ovary had no effect on fertility, whereas flies with mRpS22 deficiency specifically in germ cells were infertile and agametic, demonstrating a cell autonomous requirement for mRpS22 in germ cell development. These findings collectively identify that MRPS22, a component of the small mitochondrial ribosome subunit, is critical for ovarian development and may therefore provide insight into the pathophysiology and treatment of ovarian dysfunction.
Collapse
Affiliation(s)
- Anlu Chen
- Department of Biochemistry, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Dov Tiosano
- Division of Pediatric Endocrinology, Ruth Children's Hospital, Rambam Medical Center, Haifa 30196, Israel.,Rappaport Family Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 30196, Israel
| | - Tulay Guran
- Department of Pediatric Endocrinology and Diabetes, Marmara University Hospital, Istanbul 34899, Turkey
| | - Hagit N Baris
- Rappaport Family Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 30196, Israel.,The Genetics Institute, Rambam Health Care Campus, Haifa 3109601, Israel
| | - Yavuz Bayram
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Adi Mory
- The Genetics Institute, Rambam Health Care Campus, Haifa 3109601, Israel
| | - Laura Shapiro-Kulnane
- Department of Genetics and Genome Sciences, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Craig A Hodges
- Department of Genetics and Genome Sciences, Case Western Reserve University, Cleveland, OH 44106, USA.,Department of Pediatrics, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Zeynep C Akdemir
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Serap Turan
- Department of Pediatric Endocrinology and Diabetes, Marmara University Hospital, Istanbul 34899, Turkey
| | - Shalini N Jhangiani
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Focco van den Akker
- Department of Biochemistry, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Charles L Hoppel
- Department of Pharmacology, Center for Mitochondrial Diseases, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Helen K Salz
- Department of Genetics and Genome Sciences, Case Western Reserve University, Cleveland, OH 44106, USA
| | - James R Lupski
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA.,Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX 77030, USA.,Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA.,Texas Children's Hospital, Houston, TX 77030, USA
| | - David A Buchner
- Department of Biochemistry, Case Western Reserve University, Cleveland, OH 44106, USA.,Department of Genetics and Genome Sciences, Case Western Reserve University, Cleveland, OH 44106, USA.,Research Institute for Children's Health, Case Western Reserve University, Cleveland, OH 44106, USA
| |
Collapse
|
33
|
Xu D, Zhao Y, Weng X, Lu Y, Li W, Tang K, Chen W, Liu Z, Qi X, Zheng J, Fassett J, Zhang Y, Xu Y. Novel role of mitochondrial GTPases 1 in pathological cardiac hypertrophy. J Mol Cell Cardiol 2019; 128:105-116. [PMID: 30707992 DOI: 10.1016/j.yjmcc.2019.01.025] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Revised: 01/22/2019] [Accepted: 01/28/2019] [Indexed: 11/28/2022]
Abstract
While most mitochondrial proteins are encoded in the nucleus and translated on cytosolic/endoplasmic reticulum ribosomes, proteins encoded by mitochondrial DNA are translated on mitochondrial ribosomes. Mitochondrial GTPases 1 (MTG1) regulates mitochondrial ribosome assembly and translation, but its impact on cardiac adaptation to stress is unknown. Here, we found that MTG1 is dramatically elevated in hearts of dilated cardiomyopathy patients and in mice exposed to left ventricular pressure overload (AB). To examine the role of MTG1 in cardiac hypertrophy and heart failure, MTG1 loss/gain of function studies were performed in cultured cardiomyocytes and mice exposed to hypertrophic stress. MTG1 shRNA and adenoviral overexpression studies indicated that MTG1 expression attenuates angiotensin II-induced hypertrophy in cultured cardiomyocytes, while MTG1 KO mice exhibited no observable cardiac phenotype under basal conditions. MTG1 deficiency significantly exacerbated AB-induced cardiac hypertrophy, expression of hypertrophic stress markers, fibrosis, and LV dysfunction in comparison to WT mice. Conversely, transgenic cardiac MTG1 expression attenuated AB-induced hypertrophy and LV dysfunction. Mechanistically, MTG1 preserved mitochondrial respiratory chain complex activity during pressure overload, which further attenuated ROS generation. Moreover, we demonstrated that TAK1, P38 and JNK1/2 activity is downregulated in the MTG1 overexpression group. Importantly, dampening oxidative stress with N-acetylcysteine (NAC) lowered hypertrophy in MTG1 KO to WT levels. Collectively, our data indicate that MTG1 protects against pressure overload-induced cardiac hypertrophy and dysfunction by preserving mitochondrial function and reducing oxidative stress and downstream TAK1 stress signaling.
Collapse
Affiliation(s)
- Dachun Xu
- Department of Cardiology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China
| | - Yifan Zhao
- Department of Cardiology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China
| | - Xinyu Weng
- Department of Cardiology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China
| | - Yuyan Lu
- Department of Cardiology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China
| | - Weiming Li
- Department of Cardiology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China
| | - Kai Tang
- Department of Cardiology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China
| | - Wei Chen
- Department of Cardiology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China
| | - Zheng Liu
- Wadsworth Center, New York State Department of Health, Albany, USA
| | - Xinrui Qi
- Center for Translational Neurodegeneration and Regenerative Therapy, Shanghai Tenth People's Hospital Affiliated with Tongji University School of Medicine, China
| | - Jialing Zheng
- Center for Translational Neurodegeneration and Regenerative Therapy, Shanghai Tenth People's Hospital Affiliated with Tongji University School of Medicine, China
| | - John Fassett
- Department of Pharmacology and Toxicology, University of Graz, Graz 8020, Austria
| | - Yi Zhang
- Department of Cardiology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China.
| | - Yawei Xu
- Department of Cardiology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China.
| |
Collapse
|
34
|
Kemp PR, Griffiths M, Polkey MI. Muscle wasting in the presence of disease, why is it so variable? Biol Rev Camb Philos Soc 2018; 94:1038-1055. [PMID: 30588725 DOI: 10.1111/brv.12489] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Revised: 11/22/2018] [Accepted: 11/27/2018] [Indexed: 12/16/2022]
Abstract
Skeletal muscle wasting is a common clinical feature of many chronic diseases and also occurs in response to single acute events. The accompanying loss of strength can lead to significant disability, increased care needs and have profound negative effects on quality of life. As muscle is the most abundant source of amino acids in the body, it appears to function as a buffer for fuel and substrates that can be used to repair damage elsewhere and to feed the immune system. In essence, the fundamentals of muscle wasting are simple: less muscle is made than is broken down. However, although well-described mechanisms modulate muscle protein turnover, significant individual differences in the amount of muscle lost in the presence of a given severity of disease complicate the understanding of underlying mechanisms and suggest that individuals have different sensitivities to signals for muscle loss. Furthermore, the rate at which muscle protein is turned over under normal conditions means that clinically significant muscle loss can occur with changes in the rate of protein synthesis and/or breakdown that are too small to be measurable. Consequently, the changes in expression of factors regulating muscle turnover required to cause a decline in muscle mass are small and, except in cases of rapid wasting, there is no consistent pattern of change in the expression of factors that regulate muscle mass. MicroRNAs are fine tuners of cell phenotype and are therefore ideally suited to cause the subtle changes in proteome required to tilt the balance between synthesis and degradation in a way that causes clinically significant wasting. Herein we present a model in which muscle loss as a consequence of disease in non-muscle tissue is modulated by a set of microRNAs, the muscle expression of which is associated with severity of disease in the non-muscle tissue. These microRNAs alter fundamental biological processes including the synthesis of ribosomes and mitochondria leading to reduced protein synthesis and increased protein breakdown, thereby freeing amino acids from the muscle. We argue that the variability in muscle loss observed in the human population arises from at least two sources. The first is from pre-existing or disease-induced variation in the expression of microRNAs controlling the sensitivity of muscle to the atrophic signal and the second is from the expression of microRNAs from imprinted loci (i.e. only expressed from the maternally or paternally inherited allele) and may control the rate of myonuclear recruitment. In the absence of disease, these factors do not correlate with muscle mass, since there is no challenge to the established balance. However, in the presence of such a challenge, these microRNAs determine the rate of decline for a given disease severity. Together these mechanisms provide novel insight into the loss of muscle mass and its variation in the human population. The involvement of imprinted loci also suggests that genes that regulate early development also contribute to the ability of individuals to resist muscle loss in response to disease.
Collapse
Affiliation(s)
- Paul R Kemp
- National Heart & Lung Institute, Imperial College London, South Kensington Campus, London, SW7 2AZ, U.K
| | - Mark Griffiths
- National Heart & Lung Institute, Imperial College London, South Kensington Campus, London, SW7 2AZ, U.K
| | - Michael I Polkey
- National Institute for Health Research Respiratory Biomedical Research Unit, Royal Brompton and Harefield NHS Foundation Trust and Imperial College London, Sydney Street, London SW3 6NP, U.K
| |
Collapse
|
35
|
Calamita P, Gatti G, Miluzio A, Scagliola A, Biffo S. Translating the Game: Ribosomes as Active Players. Front Genet 2018; 9:533. [PMID: 30498507 PMCID: PMC6249331 DOI: 10.3389/fgene.2018.00533] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Accepted: 10/22/2018] [Indexed: 12/18/2022] Open
Abstract
Ribosomes have been long considered as executors of the translational program. The fact that ribosomes can control the translation of specific mRNAs or entire cellular programs is often neglected. Ribosomopathies, inherited diseases with mutations in ribosomal factors, show tissue specific defects and cancer predisposition. Studies of ribosomopathies have paved the way to the concept that ribosomes may control translation of specific mRNAs. Studies in Drosophila and mice support the existence of heterogeneous ribosomes that differentially translate mRNAs to coordinate cellular programs. Recent studies have now shown that ribosomal activity is not only a critical regulator of growth but also of metabolism. For instance, glycolysis and mitochondrial function have been found to be affected by ribosomal availability. Also, ATP levels drop in models of ribosomopathies. We discuss findings highlighting the relevance of ribosome heterogeneity in physiological and pathological conditions, as well as the possibility that in rate-limiting situations, ribosomes may favor some translational programs. We discuss the effects of ribosome heterogeneity on cellular metabolism, tumorigenesis and aging. We speculate a scenario in which ribosomes are not only executors of a metabolic program but act as modulators.
Collapse
Affiliation(s)
- Piera Calamita
- INGM, National Institute of Molecular Genetics, "Romeo ed Enrica Invernizzi", Milan, Italy.,Dipartimento di Bioscienze, Università Degli Studi Di Milano, Milan, Italy
| | - Guido Gatti
- INGM, National Institute of Molecular Genetics, "Romeo ed Enrica Invernizzi", Milan, Italy.,Dipartimento di Bioscienze, Università Degli Studi Di Milano, Milan, Italy
| | - Annarita Miluzio
- INGM, National Institute of Molecular Genetics, "Romeo ed Enrica Invernizzi", Milan, Italy
| | - Alessandra Scagliola
- INGM, National Institute of Molecular Genetics, "Romeo ed Enrica Invernizzi", Milan, Italy.,Dipartimento di Bioscienze, Università Degli Studi Di Milano, Milan, Italy
| | - Stefano Biffo
- INGM, National Institute of Molecular Genetics, "Romeo ed Enrica Invernizzi", Milan, Italy.,Dipartimento di Bioscienze, Università Degli Studi Di Milano, Milan, Italy
| |
Collapse
|
36
|
Mitochondrial DNA transcription and translation: clinical syndromes. Essays Biochem 2018; 62:321-340. [PMID: 29980628 PMCID: PMC6056718 DOI: 10.1042/ebc20170103] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Revised: 05/17/2018] [Accepted: 05/21/2018] [Indexed: 01/15/2023]
Abstract
Diagnosing primary mitochondrial diseases is challenging in clinical practice. Although, defective oxidative phosphorylation (OXPHOS) is the common final pathway, it is unknown why different mtDNA or nuclear mutations result in largely heterogeneous and often tissue -specific clinical presentations. Mitochondrial tRNA (mt-tRNA) mutations are frequent causes of mitochondrial diseases both in children and adults. However numerous nuclear mutations involved in mitochondrial protein synthesis affecting ubiquitously expressed genes have been reported in association with very tissue specific clinical manifestations suggesting that there are so far unknown factors determining the tissue specificity in mitochondrial translation. Most of these gene defects result in histological abnormalities and multiple respiratory chain defects in the affected organs. The clinical phenotypes are usually early-onset, severe, and often fatal, implying the importance of mitochondrial translation from birth. However, some rare, reversible infantile mitochondrial diseases are caused by very specific defects of mitochondrial translation. An unbiased genetic approach (whole exome sequencing, RNA sequencing) combined with proteomics and functional studies revealed novel factors involved in mitochondrial translation which contribute to the clinical manifestation and recovery in these rare reversible mitochondrial conditions.
Collapse
|
37
|
Gardeitchik T, Mohamed M, Ruzzenente B, Karall D, Guerrero-Castillo S, Dalloyaux D, van den Brand M, van Kraaij S, van Asbeck E, Assouline Z, Rio M, de Lonlay P, Scholl-Buergi S, Wolthuis DFGJ, Hoischen A, Rodenburg RJ, Sperl W, Urban Z, Brandt U, Mayr JA, Wong S, de Brouwer APM, Nijtmans L, Munnich A, Rötig A, Wevers RA, Metodiev MD, Morava E. Bi-allelic Mutations in the Mitochondrial Ribosomal Protein MRPS2 Cause Sensorineural Hearing Loss, Hypoglycemia, and Multiple OXPHOS Complex Deficiencies. Am J Hum Genet 2018; 102:685-695. [PMID: 29576219 DOI: 10.1016/j.ajhg.2018.1002.1012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Accepted: 02/19/2018] [Indexed: 05/26/2023] Open
Abstract
Biogenesis of the mitochondrial oxidative phosphorylation system, which produces the bulk of ATP for almost all eukaryotic cells, depends on the translation of 13 mtDNA-encoded polypeptides by mitochondria-specific ribosomes in the mitochondrial matrix. These mitoribosomes are dual-origin ribonucleoprotein complexes, which contain mtDNA-encoded rRNAs and tRNAs and ∼80 nucleus-encoded proteins. An increasing number of gene mutations that impair mitoribosomal function and result in multiple OXPHOS deficiencies are being linked to human mitochondrial diseases. Using exome sequencing in two unrelated subjects presenting with sensorineural hearing impairment, mild developmental delay, hypoglycemia, and a combined OXPHOS deficiency, we identified mutations in the gene encoding the mitochondrial ribosomal protein S2, which has not previously been implicated in disease. Characterization of subjects' fibroblasts revealed a decrease in the steady-state amounts of mutant MRPS2, and this decrease was shown by complexome profiling to prevent the assembly of the small mitoribosomal subunit. In turn, mitochondrial translation was inhibited, resulting in a combined OXPHOS deficiency detectable in subjects' muscle and liver biopsies as well as in cultured skin fibroblasts. Reintroduction of wild-type MRPS2 restored mitochondrial translation and OXPHOS assembly. The combination of lactic acidemia, hypoglycemia, and sensorineural hearing loss, especially in the presence of a combined OXPHOS deficiency, should raise suspicion for a ribosomal-subunit-related mitochondrial defect, and clinical recognition could allow for a targeted diagnostic approach. The identification of MRPS2 as an additional gene related to mitochondrial disease further expands the genetic and phenotypic spectra of OXPHOS deficiencies caused by impaired mitochondrial translation.
Collapse
Affiliation(s)
- Thatjana Gardeitchik
- Department of Pediatrics, Radboud University Medical Center, 6500 HB Nijmegen, the Netherlands; Department of Human Genetics, Radboud University Medical Center, 6500 HB Nijmegen, the Netherlands
| | - Miski Mohamed
- Department of Pediatrics, Radboud University Medical Center, 6500 HB Nijmegen, the Netherlands
| | - Benedetta Ruzzenente
- INSERM U1163, Université Paris Descartes-Sorbonne Paris Cité, Institut Imagine, 75015 Paris, France
| | - Daniela Karall
- Clinic for Pediatrics, Inherited Metabolic Disorders, Medical University of Innsbruck, 6020 Innsbruck, Austria
| | - Sergio Guerrero-Castillo
- Department of Pediatrics, Radboud University Medical Center, 6500 HB Nijmegen, the Netherlands; Radboud Center for Mitochondrial Medicine, Department of Pediatrics, Medical Center, 6500 HB Nijmegen, the Netherlands; Translational Metabolic Laboratory, Department of Laboratory Medicine, Radboud University Medical Center, 6500 HB Nijmegen, the Netherlands
| | - Daisy Dalloyaux
- Department of Pediatrics, Radboud University Medical Center, 6500 HB Nijmegen, the Netherlands
| | - Mariël van den Brand
- Department of Pediatrics, Radboud University Medical Center, 6500 HB Nijmegen, the Netherlands; Radboud Center for Mitochondrial Medicine, Department of Pediatrics, Medical Center, 6500 HB Nijmegen, the Netherlands
| | - Sanne van Kraaij
- Department of Pediatrics, Radboud University Medical Center, 6500 HB Nijmegen, the Netherlands; Translational Metabolic Laboratory, Department of Laboratory Medicine, Radboud University Medical Center, 6500 HB Nijmegen, the Netherlands
| | - Ellyze van Asbeck
- Department of Pediatrics, Radboud University Medical Center, 6500 HB Nijmegen, the Netherlands
| | - Zahra Assouline
- Departments of Pediatrics, Neurology, and Genetics, Hôpital Necker-Enfants-Malades, 75015 Paris, France
| | - Marlene Rio
- Departments of Pediatrics, Neurology, and Genetics, Hôpital Necker-Enfants-Malades, 75015 Paris, France
| | - Pascale de Lonlay
- Reference Center for Inherited Metabolic Diseases, Hôpital Necker-Enfants-Malades, Assistance Publique - Hôpitaux de Paris, Université Paris Descartes, Institut Imagine, 75015 Paris, France
| | - Sabine Scholl-Buergi
- Clinic for Pediatrics, Inherited Metabolic Disorders, Medical University of Innsbruck, 6020 Innsbruck, Austria
| | - David F G J Wolthuis
- Department of Pediatrics, Radboud University Medical Center, 6500 HB Nijmegen, the Netherlands
| | - Alexander Hoischen
- Department of Human Genetics, Radboud University Medical Center, 6500 HB Nijmegen, the Netherlands
| | - Richard J Rodenburg
- Radboud Center for Mitochondrial Medicine, Department of Pediatrics, Medical Center, 6500 HB Nijmegen, the Netherlands; Translational Metabolic Laboratory, Department of Laboratory Medicine, Radboud University Medical Center, 6500 HB Nijmegen, the Netherlands
| | - Wolfgang Sperl
- Clinic for Pediatrics, Inherited Metabolic Disorders, Medical University of Innsbruck, 6020 Innsbruck, Austria
| | - Zsolt Urban
- Department of Human Genetics, University of Pittsburgh Graduate School of Public Health, Pittsburgh, PA 15261, USA
| | - Ulrich Brandt
- Department of Pediatrics, Radboud University Medical Center, 6500 HB Nijmegen, the Netherlands; Radboud Center for Mitochondrial Medicine, Department of Pediatrics, Medical Center, 6500 HB Nijmegen, the Netherlands; Translational Metabolic Laboratory, Department of Laboratory Medicine, Radboud University Medical Center, 6500 HB Nijmegen, the Netherlands
| | - Johannes A Mayr
- Department of Pediatrics, Paracelsus Medical University, Salzburg, Austria
| | - Sunnie Wong
- Hayward Genetics Center, Tulane University, LA 70112, USA
| | - Arjan P M de Brouwer
- Department of Human Genetics, Radboud University Medical Center, 6500 HB Nijmegen, the Netherlands; Donders Institute for Brain, Cognition and Behaviour, Medical Center, 6500 HB Nijmegen, the Netherlands
| | - Leo Nijtmans
- Department of Pediatrics, Radboud University Medical Center, 6500 HB Nijmegen, the Netherlands; Radboud Center for Mitochondrial Medicine, Department of Pediatrics, Medical Center, 6500 HB Nijmegen, the Netherlands
| | - Arnold Munnich
- INSERM U1163, Université Paris Descartes-Sorbonne Paris Cité, Institut Imagine, 75015 Paris, France; Departments of Pediatrics, Neurology, and Genetics, Hôpital Necker-Enfants-Malades, 75015 Paris, France
| | - Agnès Rötig
- INSERM U1163, Université Paris Descartes-Sorbonne Paris Cité, Institut Imagine, 75015 Paris, France
| | - Ron A Wevers
- Translational Metabolic Laboratory, Department of Laboratory Medicine, Radboud University Medical Center, 6500 HB Nijmegen, the Netherlands
| | - Metodi D Metodiev
- INSERM U1163, Université Paris Descartes-Sorbonne Paris Cité, Institut Imagine, 75015 Paris, France.
| | - Eva Morava
- Department of Clinical Genomics, Mayo Clinic, Rochester, MN 55905, USA.
| |
Collapse
|
38
|
Bi-allelic Mutations in the Mitochondrial Ribosomal Protein MRPS2 Cause Sensorineural Hearing Loss, Hypoglycemia, and Multiple OXPHOS Complex Deficiencies. Am J Hum Genet 2018; 102:685-695. [PMID: 29576219 DOI: 10.1016/j.ajhg.2018.02.012] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Accepted: 02/19/2018] [Indexed: 12/11/2022] Open
Abstract
Biogenesis of the mitochondrial oxidative phosphorylation system, which produces the bulk of ATP for almost all eukaryotic cells, depends on the translation of 13 mtDNA-encoded polypeptides by mitochondria-specific ribosomes in the mitochondrial matrix. These mitoribosomes are dual-origin ribonucleoprotein complexes, which contain mtDNA-encoded rRNAs and tRNAs and ∼80 nucleus-encoded proteins. An increasing number of gene mutations that impair mitoribosomal function and result in multiple OXPHOS deficiencies are being linked to human mitochondrial diseases. Using exome sequencing in two unrelated subjects presenting with sensorineural hearing impairment, mild developmental delay, hypoglycemia, and a combined OXPHOS deficiency, we identified mutations in the gene encoding the mitochondrial ribosomal protein S2, which has not previously been implicated in disease. Characterization of subjects' fibroblasts revealed a decrease in the steady-state amounts of mutant MRPS2, and this decrease was shown by complexome profiling to prevent the assembly of the small mitoribosomal subunit. In turn, mitochondrial translation was inhibited, resulting in a combined OXPHOS deficiency detectable in subjects' muscle and liver biopsies as well as in cultured skin fibroblasts. Reintroduction of wild-type MRPS2 restored mitochondrial translation and OXPHOS assembly. The combination of lactic acidemia, hypoglycemia, and sensorineural hearing loss, especially in the presence of a combined OXPHOS deficiency, should raise suspicion for a ribosomal-subunit-related mitochondrial defect, and clinical recognition could allow for a targeted diagnostic approach. The identification of MRPS2 as an additional gene related to mitochondrial disease further expands the genetic and phenotypic spectra of OXPHOS deficiencies caused by impaired mitochondrial translation.
Collapse
|
39
|
Stals KL, Wakeling M, Baptista J, Caswell R, Parrish A, Rankin J, Tysoe C, Jones G, Gunning AC, Lango Allen H, Bradley L, Brady AF, Carley H, Carmichael J, Castle B, Cilliers D, Cox H, Deshpande C, Dixit A, Eason J, Elmslie F, Fry AE, Fryer A, Holder M, Homfray T, Kivuva E, McKay V, Newbury‐Ecob R, Parker M, Savarirayan R, Searle C, Shannon N, Shears D, Smithson S, Thomas E, Turnpenny PD, Varghese V, Vasudevan P, Wakeling E, Baple EL, Ellard S. Diagnosis of lethal or prenatal-onset autosomal recessive disorders by parental exome sequencing. Prenat Diagn 2018; 38:33-43. [PMID: 29096039 PMCID: PMC5836855 DOI: 10.1002/pd.5175] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Revised: 10/10/2017] [Accepted: 10/23/2017] [Indexed: 12/11/2022]
Abstract
OBJECTIVE Rare genetic disorders resulting in prenatal or neonatal death are genetically heterogeneous, but testing is often limited by the availability of fetal DNA, leaving couples without a potential prenatal test for future pregnancies. We describe our novel strategy of exome sequencing parental DNA samples to diagnose recessive monogenic disorders in an audit of the first 50 couples referred. METHOD Exome sequencing was carried out in a consecutive series of 50 couples who had 1 or more pregnancies affected with a lethal or prenatal-onset disorder. In all cases, there was insufficient DNA for exome sequencing of the affected fetus. Heterozygous rare variants (MAF < 0.001) in the same gene in both parents were selected for analysis. Likely, disease-causing variants were tested in fetal DNA to confirm co-segregation. RESULTS Parental exome analysis identified heterozygous pathogenic (or likely pathogenic) variants in 24 different genes in 26/50 couples (52%). Where 2 or more fetuses were affected, a genetic diagnosis was obtained in 18/29 cases (62%). In most cases, the clinical features were typical of the disorder, but in others, they result from a hypomorphic variant or represent the most severe form of a variable phenotypic spectrum. CONCLUSION We conclude that exome sequencing of parental samples is a powerful strategy with high clinical utility for the genetic diagnosis of lethal or prenatal-onset recessive disorders. © 2017 The Authors Prenatal Diagnosis published by John Wiley & Sons Ltd.
Collapse
|
40
|
Garros RF, Paul R, Connolly M, Lewis A, Garfield BE, Natanek SA, Bloch S, Mouly V, Griffiths MJ, Polkey MI, Kemp PR. MicroRNA-542 Promotes Mitochondrial Dysfunction and SMAD Activity and Is Elevated in Intensive Care Unit-acquired Weakness. Am J Respir Crit Care Med 2017; 196:1422-1433. [PMID: 28809518 DOI: 10.1164/rccm.201701-0101oc] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
RATIONALE Loss of skeletal muscle mass and function is a common consequence of critical illness and a range of chronic diseases, but the mechanisms by which this occurs are unclear. OBJECTIVES To identify microRNAs (miRNAs) that were increased in the quadriceps of patients with muscle wasting and to determine the molecular pathways by which they contributed to muscle dysfunction. METHODS miRNA-542-3p/5p (miR-542-3p/5p) were quantified in the quadriceps of patients with chronic obstructive pulmonary disease and intensive care unit-acquired weakness (ICUAW). The effect of miR-542-3p/5p was determined on mitochondrial function and transforming growth factor-β signaling in vitro and in vivo. MEASUREMENTS AND MAIN RESULTS miR-542-3p/5p were elevated in patients with chronic obstructive pulmonary disease but more markedly in patients with ICUAW. In vitro, miR-542-3p suppressed the expression of the mitochondrial ribosomal protein MRPS10 and reduced 12S ribosomal RNA (rRNA) expression, suggesting mitochondrial ribosomal stress. miR-542-5p increased nuclear phospho-SMAD2/3 and suppressed expression of SMAD7, SMURF1, and PPP2CA, proteins that inhibit or reduce SMAD2/3 phosphorylation, suggesting that miR-542-5p increased transforming growth factor-β signaling. In mice, miR-542 overexpression caused muscle wasting, and reduced mitochondrial function, 12S rRNA expression, and SMAD7 expression, consistent with the effects of the miRNAs in vitro. Similarly, in patients with ICUAW, the expression of 12S rRNA and of the inhibitors of SMAD2/3 phosphorylation were reduced, indicative of mitochondrial ribosomal stress and increased transforming growth factor-β signaling. In patients undergoing aortic surgery, preoperative levels of miR-542-3p/5p were positively correlated with muscle loss after surgery. CONCLUSIONS Elevated miR-542-3p/5p may cause muscle atrophy in intensive care unit patients through the promotion of mitochondrial dysfunction and activation of SMAD2/3 phosphorylation.
Collapse
Affiliation(s)
| | - Richard Paul
- 1 Molecular Medicine Section and.,2 National Institute for Health Research Respiratory Biomedical Research Unit at Royal Brompton and Harefield NHS Foundation Trust and Imperial College London, London, United Kingdom; and
| | | | | | | | | | - Susannah Bloch
- 1 Molecular Medicine Section and.,2 National Institute for Health Research Respiratory Biomedical Research Unit at Royal Brompton and Harefield NHS Foundation Trust and Imperial College London, London, United Kingdom; and
| | - Vincent Mouly
- 3 Sorbonne Universités, UPMC Univ Paris 06, INSERM UMRS974, CNRS FRE3617, Center for Research in Myology, Paris, France
| | - Mark J Griffiths
- 4 Inflammation, Repair and Development, National Heart and Lung Institute, Imperial College, South Kensington Campus, London, United Kingdom
| | - Michael I Polkey
- 2 National Institute for Health Research Respiratory Biomedical Research Unit at Royal Brompton and Harefield NHS Foundation Trust and Imperial College London, London, United Kingdom; and
| | | |
Collapse
|
41
|
Kılıç M, Oğuz KK, Kılıç E, Yüksel D, Demirci H, Sağıroğlu MŞ, Yücel-Yılmaz D, Özgül RK. A patient with mitochondrial disorder due to a novel mutation in MRPS22. Metab Brain Dis 2017; 32:1389-1393. [PMID: 28752220 DOI: 10.1007/s11011-017-0074-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Accepted: 07/19/2017] [Indexed: 11/27/2022]
Abstract
MRPS22 gene defect is a very rare newly discovered mitochondrial disorder. We report a 4-month-old severely affected male infant with MRPS22 mutation. Whole exome sequencing revealed a novel homozygous splicing mutation c.339 + 5 G > A in MRPS22 gene. He has mild dysmorphism, hypotonia, developmental delay but not hypertrophic cardiomyopathy and tubulopathy which differ from other majority of reported patients. Therefore, hypertrophic cardiomyopathy and tubulopathy may not be considered as constant features of MRPS22. With this case report, we also present first symmetrical bilateral brainstem and medial thalamic lesions, and cerebellar and cerebral atrophy on a brain MR imaging follow-up of ten months.
Collapse
Affiliation(s)
- Mustafa Kılıç
- Sami Ulus Children Hospital, Metabolism Unit, Babur cad. No: 44, 06080, Altındağ, Ankara, Turkey.
| | | | - Esra Kılıç
- Pediatric Hematology-Oncology Training and Research Hospital, Pediatric Genetic Unit, Ankara, Turkey
| | - Deniz Yüksel
- Sami Ulus Children Hospital, Pediatric Neurology Unit, Ankara, Turkey
| | | | | | - Didem Yücel-Yılmaz
- Institute of Child Health, Metabolism Unit, Hacettepe University, Ankara, Turkey
| | - Rıza Köksal Özgül
- Institute of Child Health, Metabolism Unit, Hacettepe University, Ankara, Turkey
| |
Collapse
|
42
|
Abstract
PURPOSE OF REVIEW Mitochondrial disorders are an increasingly recognized cause of heart dysfunction, with the primary manifestations being cardiomyopathy and conduction defects. This review focuses on the complex genetics of mitochondrial disease and recently discovered conditions that affect mitochondrial function. RECENT FINDINGS Next-generation sequencing techniques, especially whole-exome sequencing, have led to the discovery of a number of conditions that cause mitochondrial dysfunction and subsequent cardiac abnormalities. Nuclear DNA defects are the main cause of mitochondrial disease in children, with disease pathogenesis being related to either abnormalities in specific mitochondrial electron transport chain subunits or in proteins related to subunit or mitochondrial DNA maintenance, mitochondrial protein translation, lipid bilayer structure, or other aspects of mitochondrial function. SUMMARY Currently, symptomatic therapy using standard medications targeting relief of complications is the primary approach to treatment. There are no US Food and Drug Administration-approved therapies for the specific treatment of mitochondrial disease. However, on the basis of recent advances in understanding of the pathophysiology of these complex disorders, various novel approaches are either in clinical trials or in development.
Collapse
Affiliation(s)
- Gregory M Enns
- Department of Pediatrics, Stanford University, Stanford, California, USA
| |
Collapse
|
43
|
Lake NJ, Webb BD, Stroud DA, Richman TR, Ruzzenente B, Compton AG, Mountford HS, Pulman J, Zangarelli C, Rio M, Boddaert N, Assouline Z, Sherpa MD, Schadt EE, Houten SM, Byrnes J, McCormick EM, Zolkipli-Cunningham Z, Haude K, Zhang Z, Retterer K, Bai R, Calvo SE, Mootha VK, Christodoulou J, Rötig A, Filipovska A, Cristian I, Falk MJ, Metodiev MD, Thorburn DR. Biallelic Mutations in MRPS34 Lead to Instability of the Small Mitoribosomal Subunit and Leigh Syndrome. Am J Hum Genet 2017; 101:239-254. [PMID: 28777931 DOI: 10.1016/j.ajhg.2017.07.005] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Accepted: 07/09/2017] [Indexed: 12/30/2022] Open
Abstract
The synthesis of all 13 mitochondrial DNA (mtDNA)-encoded protein subunits of the human oxidative phosphorylation (OXPHOS) system is carried out by mitochondrial ribosomes (mitoribosomes). Defects in the stability of mitoribosomal proteins or mitoribosome assembly impair mitochondrial protein translation, causing combined OXPHOS enzyme deficiency and clinical disease. Here we report four autosomal-recessive pathogenic mutations in the gene encoding the small mitoribosomal subunit protein, MRPS34, in six subjects from four unrelated families with Leigh syndrome and combined OXPHOS defects. Whole-exome sequencing was used to independently identify all variants. Two splice-site mutations were identified, including homozygous c.321+1G>T in a subject of Italian ancestry and homozygous c.322-10G>A in affected sibling pairs from two unrelated families of Puerto Rican descent. In addition, compound heterozygous MRPS34 mutations were identified in a proband of French ancestry; a missense (c.37G>A [p.Glu13Lys]) and a nonsense (c.94C>T [p.Gln32∗]) variant. We demonstrated that these mutations reduce MRPS34 protein levels and the synthesis of OXPHOS subunits encoded by mtDNA. Examination of the mitoribosome profile and quantitative proteomics showed that the mitochondrial translation defect was caused by destabilization of the small mitoribosomal subunit and impaired monosome assembly. Lentiviral-mediated expression of wild-type MRPS34 rescued the defect in mitochondrial translation observed in skin fibroblasts from affected subjects, confirming the pathogenicity of MRPS34 mutations. Our data establish that MRPS34 is required for normal function of the mitoribosome in humans and furthermore demonstrate the power of quantitative proteomic analysis to identify signatures of defects in specific cellular pathways in fibroblasts from subjects with inherited disease.
Collapse
|
44
|
Finsterer J, Scorza FA. Renal manifestations of primary mitochondrial disorders. Biomed Rep 2017; 6:487-494. [PMID: 28515908 DOI: 10.3892/br.2017.892] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Accepted: 03/31/2017] [Indexed: 12/19/2022] Open
Abstract
The aim of the present review was to summarize and discuss previous findings concerning renal manifestations of primary mitochondrial disorders (MIDs). A literature review was performed using frequently used databases. The study identified that primary MIDs frequently present as mitochondrial multiorgan disorder syndrome (MIMODS) at onset or in the later course of the MID. Occasionally, the kidneys are affected in MIDs. Renal manifestations of MIDs include renal insufficiency, nephrolithiasis, nephrotic syndrome, renal cysts, renal tubular acidosis, Bartter-like syndrome, Fanconi syndrome, focal segmental glomerulosclerosis, tubulointerstitial nephritis, nephrocalcinosis, and benign or malign neoplasms. Among the syndromic MIDs, renal involvement has been most frequently reported in patients with mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes syndrome, Kearns-Sayre syndrome, Leigh syndrome and mitochondrial depletion syndromes. Only in single cases was renal involvement also reported in chronic progressive external ophthalmoplegia, Pearson syndrome, Leber's hereditary optic neuropathy, coenzyme-Q deficiency, X-linked sideroblastic anemia and ataxia, myopathy, lactic acidosis, and sideroblastic anemia, pyruvate dehydrogenase deficiency, growth retardation, aminoaciduria, cholestasis, iron overload, lactacidosis, and early death, and hyperuricemia, pulmonary hypertension, renal failure in infancy and alkalosis syndrome. The present study proposes that the frequency of renal involvement in MIDs is probably underestimated. Diagnosis of renal involvement follows general guidelines and treatment is symptomatic. Thus, renal manifestations of primary MIDs require recognition and appropriate management, as they determine the outcome of MID patients.
Collapse
Affiliation(s)
- Josef Finsterer
- Neurological Department, Municipal Hospital Rudolfstiftung, A-1030 Vienna, Austria
| | - Fulvio Alexandre Scorza
- Paulista de Medicina School, Federal University of São Paulo, Primeiro Andar CEP, São Paulo 04039-032, SP, Brazil
| |
Collapse
|
45
|
The Effects of Ascorbate, N-Acetylcysteine, and Resveratrol on Fibroblasts from Patients with Mitochondrial Disorders. J Clin Med 2016; 6:jcm6010001. [PMID: 28025489 PMCID: PMC5294954 DOI: 10.3390/jcm6010001] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Revised: 12/11/2016] [Accepted: 12/14/2016] [Indexed: 12/15/2022] Open
Abstract
Reactive oxygen species (ROS) are assumed to be implicated in the pathogenesis of inborn mitochondrial diseases affecting oxidative phosphorylation (OXPHOS). In the current study, we characterized the effects of three small molecules with antioxidant properties (N-acetylcysteine, ascorbate, and resveratrol) on ROS production and several OXPHOS parameters (growth in glucose free medium, ATP production, mitochondrial content and membrane potential (MMP)), in primary fibroblasts derived from seven patients with different molecularly defined and undefined mitochondrial diseases. N-acetylcysteine appeared to be the most beneficial compound, reducing ROS while increasing growth and ATP production in some patients' cells. Ascorbate showed a variable positive or negative effect on ROS, ATP production, and mitochondrial content, while incubation with resveratrol disclosed either no effect or detrimental effect on ATP production and MMP in some cells. The individual responses highlight the importance of investigating multiple parameters in addition to ROS to obtain a more balanced view of the overall effect on OXPHOS when evaluating antioxidant treatment options for mitochondrial diseases.
Collapse
|
46
|
Schaeffer RD, Liao Y, Cheng H, Grishin NV. ECOD: new developments in the evolutionary classification of domains. Nucleic Acids Res 2016; 45:D296-D302. [PMID: 27899594 PMCID: PMC5210594 DOI: 10.1093/nar/gkw1137] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Revised: 10/25/2016] [Accepted: 11/16/2016] [Indexed: 12/21/2022] Open
Abstract
Evolutionary Classification Of protein Domains (ECOD) (http://prodata.swmed.edu/ecod) comprehensively classifies protein with known spatial structures maintained by the Protein Data Bank (PDB) into evolutionary groups of protein domains. ECOD relies on a combination of automatic and manual weekly updates to achieve its high accuracy and coverage with a short update cycle. ECOD classifies the approximately 120 000 depositions of the PDB into more than 500 000 domains in ∼3400 homologous groups. We show the performance of the weekly update pipeline since the release of ECOD, describe improvements to the ECOD website and available search options, and discuss novel structures and homologous groups that have been classified in the recent updates. Finally, we discuss the future directions of ECOD and further improvements planned for the hierarchy and update process.
Collapse
Affiliation(s)
- R Dustin Schaeffer
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX 75390-9050, USA
| | - Yuxing Liao
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX 75390-9050, USA
| | - Hua Cheng
- Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390-9050, USA
| | - Nick V Grishin
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX 75390-9050, USA.,Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390-9050, USA
| |
Collapse
|
47
|
Bursle C, Narendra A, Chuk R, Cardinal J, Justo R, Lewis B, Coman D. COXPD9 an Evolving Multisystem Disease; Congenital Lactic Acidosis, Sensorineural Hearing Loss, Hypertrophic Cardiomyopathy, Cirrhosis and Interstitial Nephritis. JIMD Rep 2016; 34:105-109. [PMID: 27815843 PMCID: PMC5509545 DOI: 10.1007/8904_2016_13] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Revised: 09/13/2016] [Accepted: 09/14/2016] [Indexed: 12/03/2022] Open
Abstract
We present the second report of combined oxidative phosphorylation deficiency-9. The infant presented in the neonatal period with poor feeding, lactic acidosis and sensorineural hearing loss. He subsequently developed a lethal hypertrophic cardiomyopathy during infancy. Cirrhosis and interstitial nephritis were identified at autopsy. Exome sequencing has detected compound heterozygous mutations in the MRPL3 gene which encodes a large mitochondrial ribosome subunit protein. We identified a known heterozygous variant NM_007208 c.950>G (Pro317Arg) in the MRPL3 gene and a novel heterozygous mutation NM_007208 c.49delC p.(Arg17Aspfs*57). Mutations in MRPL3 have previously been shown to alter ribosome assembly and cause abnormal function of multiple respiratory chain complexes. Our case adds to the evolving knowledge of disorders of mitochondrial translation.
Collapse
Affiliation(s)
- C Bursle
- Neuroscience Department, The Lady Cilento Children's Hospital, Brisbane, QLD, Australia
| | - A Narendra
- Department of Paediatrics, The Wesley Hospital, 40 Chasley Street, Auchenflower, 4068, Brisbane, QLD, Australia
- UnitingCare Clinical School, The Wesley Hospital, Brisbane, QLD, Australia
| | - R Chuk
- Department of Paediatrics, The Wesley Hospital, 40 Chasley Street, Auchenflower, 4068, Brisbane, QLD, Australia
- UnitingCare Clinical School, The Wesley Hospital, Brisbane, QLD, Australia
- The School of Medicine, University of Queensland, Brisbane, QLD, Australia
| | - J Cardinal
- Advanced Medical Diagnostics, Brisbane, QLD, Australia
| | - R Justo
- The School of Medicine, University of Queensland, Brisbane, QLD, Australia
- Heart Care Partners, The Wesley Hospital, Brisbane, QLD, Australia
- Department of Cardiology, The Lady Cilento Children's Hospital, Brisbane, QLD, Australia
| | - B Lewis
- Department of Paediatrics, The Wesley Hospital, 40 Chasley Street, Auchenflower, 4068, Brisbane, QLD, Australia
- UnitingCare Clinical School, The Wesley Hospital, Brisbane, QLD, Australia
- The School of Medicine, Griffith University, Gold Coast, Nathan, QLD, Australia
| | - D Coman
- Neuroscience Department, The Lady Cilento Children's Hospital, Brisbane, QLD, Australia.
- Department of Paediatrics, The Wesley Hospital, 40 Chasley Street, Auchenflower, 4068, Brisbane, QLD, Australia.
- UnitingCare Clinical School, The Wesley Hospital, Brisbane, QLD, Australia.
- The School of Medicine, University of Queensland, Brisbane, QLD, Australia.
- Advanced Medical Diagnostics, Brisbane, QLD, Australia.
- The School of Medicine, Griffith University, Gold Coast, Nathan, QLD, Australia.
| |
Collapse
|
48
|
Guebel DV, Torres NV. Sexual Dimorphism and Aging in the Human Hyppocampus: Identification, Validation, and Impact of Differentially Expressed Genes by Factorial Microarray and Network Analysis. Front Aging Neurosci 2016; 8:229. [PMID: 27761111 PMCID: PMC5050216 DOI: 10.3389/fnagi.2016.00229] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Accepted: 09/14/2016] [Indexed: 01/09/2023] Open
Abstract
Motivation: In the brain of elderly-healthy individuals, the effects of sexual dimorphism and those due to normal aging appear overlapped. Discrimination of these two dimensions would powerfully contribute to a better understanding of the etiology of some neurodegenerative diseases, such as “sporadic” Alzheimer. Methods: Following a system biology approach, top-down and bottom-up strategies were combined. First, public transcriptome data corresponding to the transition from adulthood to the aging stage in normal, human hippocampus were analyzed through an optimized microarray post-processing (Q-GDEMAR method) together with a proper experimental design (full factorial analysis). Second, the identified genes were placed in context by building compatible networks. The subsequent ontology analyses carried out on these networks clarify the main functionalities involved. Results: Noticeably we could identify large sets of genes according to three groups: those that exclusively depend on the sex, those that exclusively depend on the age, and those that depend on the particular combinations of sex and age (interaction). The genes identified were validated against three independent sources (a proteomic study of aging, a senescence database, and a mitochondrial genetic database). We arrived to several new inferences about the biological functions compromised during aging in two ways: by taking into account the sex-independent effects of aging, and considering the interaction between age and sex where pertinent. In particular, we discuss the impact of our findings on the functions of mitochondria, autophagy, mitophagia, and microRNAs. Conclusions: The evidence obtained herein supports the occurrence of significant neurobiological differences in the hippocampus, not only between adult and elderly individuals, but between old-healthy women and old-healthy men. Hence, to obtain realistic results in further analysis of the transition from the normal aging to incipient Alzheimer, the features derived from the sexual dimorphism in hippocampus should be explicitly considered.
Collapse
Affiliation(s)
- Daniel V Guebel
- Biotechnology Counselling ServicesBuenos Aires, Argentina; Systems Biology and Mathematical Modelling Group, Departamento de Bioquímica, Microbiología, Biología Celular y Genética, Facultad de Ciencias, Universidad de La LagunaSan Cristóbal de La Laguna, España
| | - Néstor V Torres
- Systems Biology and Mathematical Modelling Group, Departamento de Bioquímica, Microbiología, Biología Celular y Genética, Facultad de Ciencias, Universidad de La Laguna San Cristóbal de La Laguna, España
| |
Collapse
|
49
|
Abstract
Oxidative phosphorylation (OXPHOS) is the mechanism whereby ATP, the major energy source for the cell, is produced by harnessing cellular respiration in the mitochondrion. This is facilitated by five multi-subunit complexes housed within the inner mitochondrial membrane. These complexes, with the exception of complex II, are of a dual genetic origin, requiring expression from nuclear and mitochondrial genes. Mitochondrially encoded mRNA is translated on the mitochondrial ribosome (mitoribosome) and the recent release of the near atomic resolution structure of the mammalian mitoribosome has highlighted its peculiar features. However, whereas some aspects of mitochondrial translation are understood, much is to be learnt about the presentation of mitochondrial mRNA to the mitoribosome, the biogenesis of the machinery, the exact role of the membrane, the constitution of the translocon/insertion machinery and the regulation of translation in the mitochondrion. This review addresses our current knowledge of mammalian mitochondrial gene expression, highlights key questions and indicates how defects in this process can result in profound mitochondrial disease.
Collapse
|
50
|
Gopisetty G, Thangarajan R. Mammalian mitochondrial ribosomal small subunit (MRPS) genes: A putative role in human disease. Gene 2016; 589:27-35. [PMID: 27170550 DOI: 10.1016/j.gene.2016.05.008] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2016] [Accepted: 05/06/2016] [Indexed: 12/25/2022]
Abstract
Mitochondria are prominently understood as power houses producing ATP the primary energy currency of the cell. However, mitochondria are also known to play an important role in apoptosis and autophagy, and mitochondrial dysregulation can lead to pathological outcomes. Mitochondria are known to contain 1500 proteins of which only 13 are coded by mitochondrial DNA and the rest are coded by nuclear genes. Protein synthesis in mitochondria involves mitochondrial ribosomes which are 55-60S particles and are composed of small 28S and large 39S subunits. A feature of mammalian mitoribosome which differentiate it from bacterial ribosomes is the increased protein content. The human mitochondrial ribosomal protein (MRP) gene family comprises of 30 genes which code for mitochondrial ribosomal small subunit and 50 genes for the large subunit. The present review focuses on the mitochondrial ribosomal small subunit genes (MRPS), presents an overview of the literature and data gleaned from publicly available gene and protein expression databases. The survey revealed aberrations in MRPS gene expression patterns in varied human diseases indicating a putative role in their etiology.
Collapse
Affiliation(s)
- Gopal Gopisetty
- Department of Molecular Oncology, Cancer Institute (WIA), Chennai, India
| | | |
Collapse
|