1
|
Song N, Mei S, Wang X, Hu G, Lu M. Focusing on mitochondria in the brain: from biology to therapeutics. Transl Neurodegener 2024; 13:23. [PMID: 38632601 PMCID: PMC11022390 DOI: 10.1186/s40035-024-00409-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2023] [Accepted: 03/13/2024] [Indexed: 04/19/2024] Open
Abstract
Mitochondria have multiple functions such as supplying energy, regulating the redox status, and producing proteins encoded by an independent genome. They are closely related to the physiology and pathology of many organs and tissues, among which the brain is particularly prominent. The brain demands 20% of the resting metabolic rate and holds highly active mitochondrial activities. Considerable research shows that mitochondria are closely related to brain function, while mitochondrial defects induce or exacerbate pathology in the brain. In this review, we provide comprehensive research advances of mitochondrial biology involved in brain functions, as well as the mitochondria-dependent cellular events in brain physiology and pathology. Furthermore, various perspectives are explored to better identify the mitochondrial roles in neurological diseases and the neurophenotypes of mitochondrial diseases. Finally, mitochondrial therapies are discussed. Mitochondrial-targeting therapeutics are showing great potentials in the treatment of brain diseases.
Collapse
Affiliation(s)
- Nanshan Song
- Department of Pharmacology, School of Medicine & Holistic Integrative Medicine, Nanjing University of Chinese Medicine, Nanjing, 210023, China
| | - Shuyuan Mei
- The First Clinical Medical College, Nanjing Medical University, Nanjing, 211166, China
| | - Xiangxu Wang
- Jiangsu Key Laboratory of Neurodegeneration, Department of Pharmacology, Neuroprotective Drug Discovery Key Laboratory, School of Basic Medical Sciences, Nanjing Medical University, Nanjing, 211166, China
| | - Gang Hu
- Department of Pharmacology, School of Medicine & Holistic Integrative Medicine, Nanjing University of Chinese Medicine, Nanjing, 210023, China.
- Jiangsu Key Laboratory of Neurodegeneration, Department of Pharmacology, Neuroprotective Drug Discovery Key Laboratory, School of Basic Medical Sciences, Nanjing Medical University, Nanjing, 211166, China.
| | - Ming Lu
- Jiangsu Key Laboratory of Neurodegeneration, Department of Pharmacology, Neuroprotective Drug Discovery Key Laboratory, School of Basic Medical Sciences, Nanjing Medical University, Nanjing, 211166, China.
- Changzhou Second People's Hospital, Changzhou Medical Center, Nanjing Medical University, Changzhou, 213000, China.
| |
Collapse
|
2
|
Zambon AA, Ghezzi D, Baldoli C, Cutillo G, Fontana K, Sofia V, Patricelli MG, Nasca A, Vinci S, Spiga I, Lamantea E, Fanelli GF, Sora MGN, Rovelli R, Poloniato A, Carrera P, Filippi M, Barera G. Expanding the spectrum of neonatal-onset AIFM1-associated disorders. Ann Clin Transl Neurol 2023; 10:1844-1853. [PMID: 37644805 PMCID: PMC10578896 DOI: 10.1002/acn3.51876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Revised: 07/14/2023] [Accepted: 07/31/2023] [Indexed: 08/31/2023] Open
Abstract
OBJECTIVES Pathogenic variants in AIFM1 have been associated with a wide spectrum of disorders, spanning from CMT4X to mitochondrial encephalopathy. Here we present a novel phenotype and review the existing literature on AIFM1-related disorders. METHODS We performed EEG recordings, brain MRI and MR Spectroscopy, metabolic screening, echocardiogram, clinical exome sequencing (CES) and family study. Effects of the variant were established on cultured fibroblasts from skin punch biopsy. RESULTS The patient presented with drug-resistant, electro-clinical, multifocal seizures 6 h after birth. Brain MRI revealed prominent brain swelling of both hemispheres and widespread signal alteration in large part of the cortex and of the thalami, with sparing of the basal nuclei. CES analysis revealed the likely pathogenic variant c.5T>C; p.(Phe2Ser) in the AIFM1 gene. The affected amino acid residue is located in the mitochondrial targeting sequence. Functional studies on cultured fibroblast showed a clear reduction in AIFM1 protein amount and defective activities of respiratory chain complexes I, III and IV. No evidence of protein mislocalization or accumulation of precursor protein was observed. Riboflavin, Coenzyme Q10 and thiamine supplementation was therefore given. At 6 months of age, the patient exhibited microcephaly but did not experience any further deterioration. He is still fed orally and there is no evidence of muscle weakness or atrophy. INTERPRETATION This is the first AIFM1 case associated with neonatal seizures and diffuse white matter involvement with relative sparing of basal ganglia, in the absence of clinical signs suggestive of myopathy or motor neuron disease.
Collapse
Affiliation(s)
- Alberto A. Zambon
- Unit of NeurologySan Raffaele Scientific InstituteMilanItaly
- Neuromuscular Repair Unit, Institute of Experimental Neurology (InSpe), Division of NeuroscienceIRCCS Ospedale San RaffaeleMilanItaly
| | - Daniele Ghezzi
- Medical Genetics and Neurogenetics UnitFondazione IRCCS Istituto Neurologico Carlo BestaMilanItaly
- Department of Pathophysiology and TransplantationUniversity of MilanMilanItaly
| | - Cristina Baldoli
- Department of NeuroradiologySan Raffaele Scientific InstituteMilanItaly
| | - Gianni Cutillo
- Unit of NeurologySan Raffaele Scientific InstituteMilanItaly
- Neurophysiology ServiceSan Raffaele Scientific InstituteMilanItaly
| | - Katia Fontana
- Department of NeonatologySan Raffaele Scientific InstituteMilanItaly
| | - Valentina Sofia
- Department of NeonatologySan Raffaele Scientific InstituteMilanItaly
| | | | - Alessia Nasca
- Medical Genetics and Neurogenetics UnitFondazione IRCCS Istituto Neurologico Carlo BestaMilanItaly
| | - Stefano Vinci
- Medical Genetics and Neurogenetics UnitFondazione IRCCS Istituto Neurologico Carlo BestaMilanItaly
| | - Ivana Spiga
- Laboratory of Genomics and Clinical GeneticsSan Raffaele Scientific InstituteMilanItaly
| | - Eleonora Lamantea
- Medical Genetics and Neurogenetics UnitFondazione IRCCS Istituto Neurologico Carlo BestaMilanItaly
| | | | | | - Rosanna Rovelli
- Medical Genetics and Neurogenetics UnitFondazione IRCCS Istituto Neurologico Carlo BestaMilanItaly
| | - Antonella Poloniato
- Medical Genetics and Neurogenetics UnitFondazione IRCCS Istituto Neurologico Carlo BestaMilanItaly
| | - Paola Carrera
- Laboratory of Genomics and Clinical GeneticsSan Raffaele Scientific InstituteMilanItaly
- Unit of Genomics for Human Disease DiagnosisSan Raffaele Scientific InstituteMilanItaly
| | - Massimo Filippi
- Unit of NeurologySan Raffaele Scientific InstituteMilanItaly
- Neurophysiology ServiceSan Raffaele Scientific InstituteMilanItaly
- Vita‐Salute San Raffaele UniversityMilanItaly
| | - Graziano Barera
- Medical Genetics and Neurogenetics UnitFondazione IRCCS Istituto Neurologico Carlo BestaMilanItaly
| |
Collapse
|
3
|
Wang R, Bai X, Yang H, Ma J, Yu S, Lu Z. Identification of a novel AIFM1 variant from a Chinese family with auditory neuropathy. Front Genet 2022; 13:1064823. [DOI: 10.3389/fgene.2022.1064823] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2022] [Accepted: 11/07/2022] [Indexed: 11/22/2022] Open
Abstract
Background: Auditory neuropathy (AN) is a specific type of hearing loss characterized by impaired language comprehension. Apoptosis inducing factor mitochondrion associated 1 (AIFM1) is the most common gene associated with late-onset AN. In this study, we aimed to screen the pathogenic variant of AIFM1 in a Chinese family with AN and to explore the molecular mechanism underlying the function of such variant in the development of AN.Methods: One patient with AN and eight unaffected individuals from a Chinese family were enrolled in this study. A comprehensive clinical evaluation was performed on all participants. A targeted next-generation sequencing (NGS) analysis of a total of 406 known deafness genes was performed to screen the potential pathogenic variants in the proband. Sanger sequencing was used to confirm the variants identified in all participants. The pathogenicity of variant was predicted by bioinformatics analysis. Immunofluorescence and Western blot analyses were performed to evaluate the subcellular distribution and expression of the wild type (WT) and mutant AIFM1 proteins. Cell apoptosis was evaluated based on the TUNEL analyses.Results: Based on the clinical evaluations, the proband in this family was diagnosed with AN. The results of NGS and Sanger sequencing showed that a novel missense mutation of AIFM1, i.e., c.1367A > G (p. D456G), was identified in this family. Bioinformatics analysis indicated that this variant was pathogenic. Functional analysis showed that in comparison with the WT, the mutation c.1367A > G of AIFM1 showed no effect on its subcellular localization and the ability to induce apoptosis, but changed its protein expression level.Conclusion: A novel variant of AIFM1 was identified for the first time, which was probably the genetic cause of AN in a Chinese family with AN.
Collapse
|
4
|
Hanaford A, Johnson SC. The immune system as a driver of mitochondrial disease pathogenesis: a review of evidence. Orphanet J Rare Dis 2022; 17:335. [PMID: 36056365 PMCID: PMC9438277 DOI: 10.1186/s13023-022-02495-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2022] [Accepted: 08/15/2022] [Indexed: 12/04/2022] Open
Abstract
Background Genetic mitochondrial diseases represent a significant challenge to human health. These diseases are extraordinarily heterogeneous in clinical presentation and genetic origin, and often involve multi-system disease with severe progressive symptoms. Mitochondrial diseases represent the most common cause of inherited metabolic disorders and one of the most common causes of inherited neurologic diseases, yet no proven therapeutic strategies yet exist. The basic cell and molecular mechanisms underlying the pathogenesis of mitochondrial diseases have not been resolved, hampering efforts to develop therapeutic agents. Main body In recent pre-clinical work, we have shown that pharmacologic agents targeting the immune system can prevent disease in the Ndufs4(KO) model of Leigh syndrome, indicating that the immune system plays a causal role in the pathogenesis of at least this form of mitochondrial disease. Intriguingly, a number of case reports have indicated that immune-targeting therapeutics may be beneficial in the setting of genetic mitochondrial disease. Here, we summarize clinical and pre-clinical evidence suggesting a key role for the immune system in mediating the pathogenesis of at least some forms of genetic mitochondrial disease. Conclusions Significant clinical and pre-clinical evidence indicates a key role for the immune system as a significant in the pathogenesis of at least some forms of genetic mitochondrial disease.
Collapse
Affiliation(s)
- Allison Hanaford
- Center for Integrative Brain Research, Seattle Children's Research Institute, 1900 9th Ave., JMB-925, Seattle, WA, 98101, USA
| | - Simon C Johnson
- Center for Integrative Brain Research, Seattle Children's Research Institute, 1900 9th Ave., JMB-925, Seattle, WA, 98101, USA. .,Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA, USA. .,Department of Anesthesiology and Pain Medicine, University of Washington, Seattle, WA, USA. .,Department of Neurology, University of Washington, Seattle, WA, USA.
| |
Collapse
|
5
|
Wischhof L, Scifo E, Ehninger D, Bano D. AIFM1 beyond cell death: An overview of this OXPHOS-inducing factor in mitochondrial diseases. EBioMedicine 2022; 83:104231. [PMID: 35994922 PMCID: PMC9420475 DOI: 10.1016/j.ebiom.2022.104231] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Revised: 08/01/2022] [Accepted: 08/02/2022] [Indexed: 11/17/2022] Open
Abstract
Apoptosis-inducing factor (AIF) is a mitochondrial intermembrane space flavoprotein with diverse functions in cellular physiology. In this regard, a large number of studies have elucidated AIF's participation to chromatin condensation during cell death in development, cancer, cardiovascular and brain disorders. However, the discovery of rare AIFM1 mutations in patients has shifted the interest of biomedical researchers towards AIF's contribution to pathogenic mechanisms underlying inherited AIFM1-linked metabolic diseases. The functional characterization of AIF binding partners has rapidly advanced our understanding of AIF biology within the mitochondria and beyond its widely reported role in cell death. At the present time, it is reasonable to assume that AIF contributes to cell survival by promoting biogenesis and maintenance of the mitochondrial oxidative phosphorylation (OXPHOS) system. With this review, we aim to outline the current knowledge around the vital role of AIF by primarily focusing on currently reported human diseases that have been linked to AIFM1 deficiency.
Collapse
Affiliation(s)
- Lena Wischhof
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Enzo Scifo
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Dan Ehninger
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Daniele Bano
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany.
| |
Collapse
|
6
|
Ma C, Wang X, He S, Zhang L, Bai J, Qu L, Qi J, Zheng X, Zhu X, Mei J, Guan X, Yuan H, Zhu D. Ubiquitinated AIF is a major mediator of hypoxia-induced mitochondrial dysfunction and pulmonary artery smooth muscle cell proliferation. Cell Biosci 2022; 12:9. [PMID: 35090552 PMCID: PMC8796423 DOI: 10.1186/s13578-022-00744-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Accepted: 12/30/2021] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Excessive proliferation of pulmonary artery smooth muscle cells (PASMCs) is the main cause of hypoxic pulmonary hypertension (PH), and mitochondrial homeostasis plays a crucial role. However, the specific molecular regulatory mechanism of mitochondrial function in PASMCs remains unclear. METHODS In this study, using the CCK8 assay, EdU incorporation, flow cytometry, Western blotting, co-IP, mass spectrometry, electron microscopy, immunofluorescence, Seahorse extracellular flux analysis and echocardiography, we investigated the specific involvement of apoptosis-inducing factor (AIF), a mitochondrial oxidoreductase in regulating mitochondrial energy metabolism and mitophagy in PASMCs. RESULTS In vitro, AIF deficiency in hypoxia leads to impaired oxidative phosphorylation and increased glycolysis and ROS release because of the loss of mitochondrial complex I activity. AIF was also downregulated and ubiquitinated under hypoxia leading to the abnormal occurrence of mitophagy and autophagy through its interaction with ubiquitin protein UBA52. In vivo, treatment with the adeno-associated virus vector to overexpress AIF protected pulmonary vascular remodeling from dysfunctional and abnormal proliferation. CONCLUSIONS Taken together, our results identify AIF as a potential therapeutic target for PH and reveal a novel posttranscriptional regulatory mechanism in hypoxia-induced mitochondrial dysfunction.
Collapse
Affiliation(s)
- Cui Ma
- Central Laboratory of Harbin Medical University (Daqing), 39 Xinyang Road, Daqing, 163319, People's Republic of China
- College of Medical Laboratory Science and Technology, Harbin Medical University (Daqing), Daqing, 163319, People's Republic of China
| | - Xiaoying Wang
- Central Laboratory of Harbin Medical University (Daqing), 39 Xinyang Road, Daqing, 163319, People's Republic of China
- College of Pharmacy, Harbin Medical University, Harbin, 150081, People's Republic of China
| | - Siyu He
- Central Laboratory of Harbin Medical University (Daqing), 39 Xinyang Road, Daqing, 163319, People's Republic of China
- College of Pharmacy, Harbin Medical University, Harbin, 150081, People's Republic of China
| | - Lixin Zhang
- Central Laboratory of Harbin Medical University (Daqing), 39 Xinyang Road, Daqing, 163319, People's Republic of China
- College of Medical Laboratory Science and Technology, Harbin Medical University (Daqing), Daqing, 163319, People's Republic of China
| | - June Bai
- Central Laboratory of Harbin Medical University (Daqing), 39 Xinyang Road, Daqing, 163319, People's Republic of China
- College of Pharmacy, Harbin Medical University, Harbin, 150081, People's Republic of China
| | - Lihui Qu
- College of Basic Medical Sciences, Harbin Medical University (Daqing), Daqing, 163319, People's Republic of China
| | - Jing Qi
- College of Basic Medical Sciences, Harbin Medical University (Daqing), Daqing, 163319, People's Republic of China
| | - Xiaodong Zheng
- College of Basic Medical Sciences, Harbin Medical University (Daqing), Daqing, 163319, People's Republic of China
| | - Xiangrui Zhu
- Central Laboratory of Harbin Medical University (Daqing), 39 Xinyang Road, Daqing, 163319, People's Republic of China
- College of Medical Laboratory Science and Technology, Harbin Medical University (Daqing), Daqing, 163319, People's Republic of China
| | - Jian Mei
- Central Laboratory of Harbin Medical University (Daqing), 39 Xinyang Road, Daqing, 163319, People's Republic of China
- College of Medical Laboratory Science and Technology, Harbin Medical University (Daqing), Daqing, 163319, People's Republic of China
| | - Xiaoyu Guan
- Central Laboratory of Harbin Medical University (Daqing), 39 Xinyang Road, Daqing, 163319, People's Republic of China
- College of Pharmacy, Harbin Medical University, Harbin, 150081, People's Republic of China
| | - Hao Yuan
- Central Laboratory of Harbin Medical University (Daqing), 39 Xinyang Road, Daqing, 163319, People's Republic of China
- College of Pharmacy, Harbin Medical University, Harbin, 150081, People's Republic of China
| | - Daling Zhu
- Central Laboratory of Harbin Medical University (Daqing), 39 Xinyang Road, Daqing, 163319, People's Republic of China.
- College of Pharmacy, Harbin Medical University, Harbin, 150081, People's Republic of China.
- State Province Key Laboratories of Biomedicine-Pharmaceutics of China, Daqing, 163319, People's Republic of China.
- Key Laboratory of Cardiovascular Medicine Research, Ministry of Education, Daqing, 163319, People's Republic of China.
| |
Collapse
|
7
|
Beijer D, Agnew T, Rack JGM, Prokhorova E, Deconinck T, Ceulemans B, Peric S, Milic Rasic V, De Jonghe P, Ahel I, Baets J. Biallelic ADPRHL2 mutations in complex neuropathy affect ADP ribosylation and DNA damage response. Life Sci Alliance 2021; 4:e202101057. [PMID: 34479984 PMCID: PMC8424258 DOI: 10.26508/lsa.202101057] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 08/24/2021] [Accepted: 08/25/2021] [Indexed: 12/28/2022] Open
Abstract
ADP ribosylation is a reversible posttranslational modification mediated by poly(ADP-ribose)transferases (e.g., PARP1) and (ADP-ribosyl)hydrolases (e.g., ARH3 and PARG), ensuring synthesis and removal of mono-ADP-ribose or poly-ADP-ribose chains on protein substrates. Dysregulation of ADP ribosylation signaling has been associated with several neurodegenerative diseases, including Parkinson's disease, amyotrophic lateral sclerosis, and Huntington's disease. Recessive ADPRHL2/ARH3 mutations are described to cause a stress-induced epileptic ataxia syndrome with developmental delay and axonal neuropathy (CONDSIAS). Here, we present two families with a neuropathy predominant disorder and homozygous mutations in ADPRHL2 We characterized a novel C26F mutation, demonstrating protein instability and reduced protein function. Characterization of the recurrent V335G mutant demonstrated mild loss of expression with retained enzymatic activity. Although the V335G mutation retains its mitochondrial localization, it has altered cytosolic/nuclear localization. This minimally affects basal ADP ribosylation but results in elevated nuclear ADP ribosylation during stress, demonstrating the vital role of ADP ribosylation reversal by ARH3 in DNA damage control.
Collapse
Affiliation(s)
- Danique Beijer
- Translational Neurosciences, Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium
- Laboratory of Neuromuscular Pathology, Institute Born-Bunge, University of Antwerp, Antwerp, Belgium
| | - Thomas Agnew
- Sir William Dunn School of Pathology, Oxford University, Oxford, UK
| | | | | | - Tine Deconinck
- Translational Neurosciences, Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium
- Laboratory of Neuromuscular Pathology, Institute Born-Bunge, University of Antwerp, Antwerp, Belgium
| | - Berten Ceulemans
- Department of Pediatric Neurology, Antwerp University Hospital, Antwerp, Belgium
| | - Stojan Peric
- Neurology Clinic, Clinical Center of Serbia, Faculty of Medicine, University of Belgrade, Belgrade, Serbia
| | - Vedrana Milic Rasic
- Clinic for Neurology and Psychiatry for Children and Youth, Faculty of Medicine, University of Belgrade, Belgrade, Serbia
| | - Peter De Jonghe
- Translational Neurosciences, Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium
- Laboratory of Neuromuscular Pathology, Institute Born-Bunge, University of Antwerp, Antwerp, Belgium
- Neuromuscular Reference Centre, Department of Neurology, Antwerp University Hospital, Antwerp, Belgium
| | - Ivan Ahel
- Sir William Dunn School of Pathology, Oxford University, Oxford, UK
| | - Jonathan Baets
- Translational Neurosciences, Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium
- Laboratory of Neuromuscular Pathology, Institute Born-Bunge, University of Antwerp, Antwerp, Belgium
- Neuromuscular Reference Centre, Department of Neurology, Antwerp University Hospital, Antwerp, Belgium
| |
Collapse
|
8
|
Gould RL, Craig SW, McClatchy S, Churchill GA, Pazdro R. Genetic mapping of renal glutathione suggests a novel regulatory locus on the murine X chromosome and overlap with hepatic glutathione regulation. Free Radic Biol Med 2021; 174:28-39. [PMID: 34324982 PMCID: PMC8597656 DOI: 10.1016/j.freeradbiomed.2021.07.035] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Revised: 07/14/2021] [Accepted: 07/25/2021] [Indexed: 11/29/2022]
Abstract
Glutathione (GSH) is a critical cellular antioxidant that protects against byproducts of aerobic metabolism and other reactive electrophiles to prevent oxidative stress and cell death. Proper maintenance of its reduced form, GSH, in excess of its oxidized form, GSSG, prevents oxidative stress in the kidney and protects against the development of chronic kidney disease. Evidence has indicated that renal concentrations of GSH and GSSG, as well as their ratio GSH/GSSG, are moderately heritable, and past research has identified polymorphisms and candidate genes associated with these phenotypes in mice. Yet those discoveries were made with in silico mapping methods that are prone to false positives and power limitations, so the true loci and candidate genes that control renal glutathione remain unknown. The present study utilized high-resolution gene mapping with the Diversity Outbred mouse stock to identify causal loci underlying variation in renal GSH levels and redox status. Mapping output identified a suggestive locus associated with renal GSH on murine chromosome X at 51.602 Mbp, and bioinformatic analyses identified apoptosis-inducing factor mitochondria-associated 1 (Aifm1) as the most plausible candidate. Then, mapping outputs were compiled and compared against the genetic architecture of the hepatic GSH system, and we discovered a locus on murine chromosome 14 that overlaps between hepatic GSH concentrations and renal GSH redox potential. Overall, the results support our previously proposed model that the GSH redox system is regulated by both global and tissue-specific loci, vastly improving our understanding of GSH and its regulation and proposing new candidate genes for future mechanistic studies.
Collapse
Affiliation(s)
- Rebecca L Gould
- Department of Nutritional Sciences, University of Georgia, 305 Sanford Drive, Athens, GA, 30602, USA
| | - Steven W Craig
- Department of Nutritional Sciences, University of Georgia, 305 Sanford Drive, Athens, GA, 30602, USA
| | - Susan McClatchy
- The Jackson Laboratory, 600 Main Street, Bar Harbor, ME, 04609, USA
| | - Gary A Churchill
- The Jackson Laboratory, 600 Main Street, Bar Harbor, ME, 04609, USA
| | - Robert Pazdro
- Department of Nutritional Sciences, University of Georgia, 305 Sanford Drive, Athens, GA, 30602, USA.
| |
Collapse
|
9
|
Molecular Insights into Mitochondrial Protein Translocation and Human Disease. Genes (Basel) 2021; 12:genes12071031. [PMID: 34356047 PMCID: PMC8305315 DOI: 10.3390/genes12071031] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2021] [Revised: 06/27/2021] [Accepted: 06/30/2021] [Indexed: 12/11/2022] Open
Abstract
In human mitochondria, mtDNA encodes for only 13 proteins, all components of the OXPHOS system. The rest of the mitochondrial components, which make up approximately 99% of its proteome, are encoded in the nuclear genome, synthesized in cytosolic ribosomes and imported into mitochondria. Different import machineries translocate mitochondrial precursors, depending on their nature and the final destination inside the organelle. The proper and coordinated function of these molecular pathways is critical for mitochondrial homeostasis. Here, we will review molecular details about these pathways, which components have been linked to human disease and future perspectives on the field to expand the genetic landscape of mitochondrial diseases.
Collapse
|
10
|
Liu S, Zhou M, Ruan Z, Wang Y, Chang C, Sasaki M, Rajaram V, Lemoff A, Nambiar K, Wang JE, Hatanpaa KJ, Luo W, Dawson TM, Dawson VL, Wang Y. AIF3 splicing switch triggers neurodegeneration. Mol Neurodegener 2021; 16:25. [PMID: 33853653 PMCID: PMC8048367 DOI: 10.1186/s13024-021-00442-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2020] [Accepted: 03/12/2021] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Apoptosis-inducing factor (AIF), as a mitochondrial flavoprotein, plays a fundamental role in mitochondrial bioenergetics that is critical for cell survival and also mediates caspase-independent cell death once it is released from mitochondria and translocated to the nucleus under ischemic stroke or neurodegenerative diseases. Although alternative splicing regulation of AIF has been implicated, it remains unknown which AIF splicing isoform will be induced under pathological conditions and how it impacts mitochondrial functions and neurodegeneration in adult brain. METHODS AIF splicing induction in brain was determined by multiple approaches including 5' RACE, Sanger sequencing, splicing-specific PCR assay and bottom-up proteomic analysis. The role of AIF splicing in mitochondria and neurodegeneration was determined by its biochemical properties, cell death analysis, morphological and functional alterations and animal behavior. Three animal models, including loss-of-function harlequin model, gain-of-function AIF3 knockin model and conditional inducible AIF splicing model established using either Cre-loxp recombination or CRISPR/Cas9 techniques, were applied to explore underlying mechanisms of AIF splicing-induced neurodegeneration. RESULTS We identified a nature splicing AIF isoform lacking exons 2 and 3 named as AIF3. AIF3 was undetectable under physiological conditions but its expression was increased in mouse and human postmortem brain after stroke. AIF3 splicing in mouse brain caused enlarged ventricles and severe neurodegeneration in the forebrain regions. These AIF3 splicing mice died 2-4 months after birth. AIF3 splicing-triggered neurodegeneration involves both mitochondrial dysfunction and AIF3 nuclear translocation. We showed that AIF3 inhibited NADH oxidase activity, ATP production, oxygen consumption, and mitochondrial biogenesis. In addition, expression of AIF3 significantly increased chromatin condensation and nuclear shrinkage leading to neuronal cell death. However, loss-of-AIF alone in harlequin or gain-of-AIF3 alone in AIF3 knockin mice did not cause robust neurodegeneration as that observed in AIF3 splicing mice. CONCLUSIONS We identified AIF3 as a disease-inducible isoform and established AIF3 splicing mouse model. The molecular mechanism underlying AIF3 splicing-induced neurodegeneration involves mitochondrial dysfunction and AIF3 nuclear translocation resulting from the synergistic effect of loss-of-AIF and gain-of-AIF3. Our study provides a valuable tool to understand the role of AIF3 splicing in brain and a potential therapeutic target to prevent/delay the progress of neurodegenerative diseases.
Collapse
Affiliation(s)
- Shuiqiao Liu
- Department of Pathology, University of Texas Southwestern Medical Center, Dallas, TX 75390 USA
- Department of Neurology, University of Texas Southwestern Medical Center, Dallas, TX 75390 USA
| | - Mi Zhou
- Department of Pathology, University of Texas Southwestern Medical Center, Dallas, TX 75390 USA
- Department of Neurology, University of Texas Southwestern Medical Center, Dallas, TX 75390 USA
| | - Zhi Ruan
- Department of Pathology, University of Texas Southwestern Medical Center, Dallas, TX 75390 USA
- Department of Neurology, University of Texas Southwestern Medical Center, Dallas, TX 75390 USA
| | - Yanan Wang
- Department of Pathology, University of Texas Southwestern Medical Center, Dallas, TX 75390 USA
- Department of Neurology, University of Texas Southwestern Medical Center, Dallas, TX 75390 USA
| | - Calvin Chang
- Neuroregeneration and Stem Cell Programs, Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205 USA
| | - Masayuki Sasaki
- Neuroregeneration and Stem Cell Programs, Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205 USA
- Departments of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205 USA
| | - Veena Rajaram
- Department of Pathology, University of Texas Southwestern Medical Center, Dallas, TX 75390 USA
| | - Andrew Lemoff
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75390 USA
| | - Kalyani Nambiar
- Neuroregeneration and Stem Cell Programs, Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205 USA
| | - Jennifer E. Wang
- Department of Pathology, University of Texas Southwestern Medical Center, Dallas, TX 75390 USA
- Department of Neurology, University of Texas Southwestern Medical Center, Dallas, TX 75390 USA
| | - Kimmo J. Hatanpaa
- Department of Pathology, University of Texas Southwestern Medical Center, Dallas, TX 75390 USA
| | - Weibo Luo
- Department of Pathology, University of Texas Southwestern Medical Center, Dallas, TX 75390 USA
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX 75390 USA
| | - Ted M. Dawson
- Neuroregeneration and Stem Cell Programs, Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205 USA
- Departments of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205 USA
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205 USA
| | - Valina L. Dawson
- Neuroregeneration and Stem Cell Programs, Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205 USA
- Departments of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205 USA
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205 USA
- Physiology, Johns Hopkins University School of Medicine, Baltimore, MD 21205 USA
| | - Yingfei Wang
- Department of Pathology, University of Texas Southwestern Medical Center, Dallas, TX 75390 USA
- Department of Neurology, University of Texas Southwestern Medical Center, Dallas, TX 75390 USA
- Neuroregeneration and Stem Cell Programs, Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205 USA
- Departments of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205 USA
| |
Collapse
|
11
|
Edwards R, Eaglesfield R, Tokatlidis K. The mitochondrial intermembrane space: the most constricted mitochondrial sub-compartment with the largest variety of protein import pathways. Open Biol 2021; 11:210002. [PMID: 33715390 PMCID: PMC8061763 DOI: 10.1098/rsob.210002] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The mitochondrial intermembrane space (IMS) is the most constricted sub-mitochondrial compartment, housing only about 5% of the mitochondrial proteome, and yet is endowed with the largest variability of protein import mechanisms. In this review, we summarize our current knowledge of the major IMS import pathway based on the oxidative protein folding pathway and discuss the stunning variability of other IMS protein import pathways. As IMS-localized proteins only have to cross the outer mitochondrial membrane, they do not require energy sources like ATP hydrolysis in the mitochondrial matrix or the inner membrane electrochemical potential which are critical for import into the matrix or insertion into the inner membrane. We also explore several atypical IMS import pathways that are still not very well understood and are guided by poorly defined or completely unknown targeting peptides. Importantly, many of the IMS proteins are linked to several human diseases, and it is therefore crucial to understand how they reach their normal site of function in the IMS. In the final part of this review, we discuss current understanding of how such IMS protein underpin a large spectrum of human disorders.
Collapse
Affiliation(s)
- Ruairidh Edwards
- Institute of Molecular Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, University Avenue, Glasgow G12 8QQ, UK
| | - Ross Eaglesfield
- Institute of Molecular Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, University Avenue, Glasgow G12 8QQ, UK
| | - Kostas Tokatlidis
- Institute of Molecular Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, University Avenue, Glasgow G12 8QQ, UK
| |
Collapse
|
12
|
Beijer D, Baets J. The expanding genetic landscape of hereditary motor neuropathies. Brain 2021; 143:3540-3563. [PMID: 33210134 DOI: 10.1093/brain/awaa311] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 07/15/2020] [Accepted: 07/27/2020] [Indexed: 12/12/2022] Open
Abstract
Hereditary motor neuropathies are clinically and genetically diverse disorders characterized by length-dependent axonal degeneration of lower motor neurons. Although currently as many as 26 causal genes are known, there is considerable missing heritability compared to other inherited neuropathies such as Charcot-Marie-Tooth disease. Intriguingly, this genetic landscape spans a discrete number of key biological processes within the peripheral nerve. Also, in terms of underlying pathophysiology, hereditary motor neuropathies show striking overlap with several other neuromuscular and neurological disorders. In this review, we provide a current overview of the genetic spectrum of hereditary motor neuropathies highlighting recent reports of novel genes and mutations or recent discoveries in the underlying disease mechanisms. In addition, we link hereditary motor neuropathies with various related disorders by addressing the main affected pathways of disease divided into five major processes: axonal transport, tRNA aminoacylation, RNA metabolism and DNA integrity, ion channels and transporters and endoplasmic reticulum.
Collapse
Affiliation(s)
- Danique Beijer
- Translational Neurosciences, Faculty of Medicine and Health Sciences, University of Antwerp, Belgium.,Laboratory of Neuromuscular Pathology, Institute Born-Bunge, University of Antwerp, Belgium
| | - Jonathan Baets
- Translational Neurosciences, Faculty of Medicine and Health Sciences, University of Antwerp, Belgium.,Laboratory of Neuromuscular Pathology, Institute Born-Bunge, University of Antwerp, Belgium.,Neuromuscular Reference Centre, Department of Neurology, Antwerp University Hospital, Belgium
| |
Collapse
|
13
|
Palmer CS, Anderson AJ, Stojanovski D. Mitochondrial protein import dysfunction: mitochondrial disease, neurodegenerative disease and cancer. FEBS Lett 2021; 595:1107-1131. [PMID: 33314127 DOI: 10.1002/1873-3468.14022] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 10/12/2020] [Accepted: 10/17/2020] [Indexed: 12/13/2022]
Abstract
The majority of proteins localised to mitochondria are encoded by the nuclear genome, with approximately 1500 proteins imported into mammalian mitochondria. Dysfunction in this fundamental cellular process is linked to a variety of pathologies including neuropathies, cardiovascular disorders, myopathies, neurodegenerative diseases and cancer, demonstrating the importance of mitochondrial protein import machinery for cellular function. Correct import of proteins into mitochondria requires the co-ordinated activity of multimeric protein translocation and sorting machineries located in both the outer and inner mitochondrial membranes, directing the imported proteins to the destined mitochondrial compartment. This dynamic process maintains cellular homeostasis, and its dysregulation significantly affects cellular signalling pathways and metabolism. This review summarises current knowledge of the mammalian mitochondrial import machinery and the pathological consequences of mutation of its components. In addition, we will discuss the role of mitochondrial import in cancer, and our current understanding of the role of mitochondrial import in neurodegenerative diseases including Alzheimer's disease, Huntington's disease and Parkinson's disease.
Collapse
Affiliation(s)
- Catherine S Palmer
- Department of Biochemistry and Molecular Biology and The Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Australia
| | - Alexander J Anderson
- Department of Biochemistry and Molecular Biology and The Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Australia
| | - Diana Stojanovski
- Department of Biochemistry and Molecular Biology and The Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Australia
| |
Collapse
|
14
|
W196 and the β-Hairpin Motif Modulate the Redox Switch of Conformation and the Biomolecular Interaction Network of the Apoptosis-Inducing Factor. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2021; 2021:6673661. [PMID: 33510840 PMCID: PMC7822688 DOI: 10.1155/2021/6673661] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 12/09/2020] [Accepted: 12/18/2020] [Indexed: 01/07/2023]
Abstract
The human apoptosis-inducing factor (hAIF) is a moonlight flavoprotein involved in mitochondrial respiratory complex assembly and caspase-independent programmed cell death. These functions might be modulated by its redox-linked structural transition that enables hAIF to act as a NAD(H/+) redox sensor. Upon reduction with NADH, hAIF undergoes a conformational reorganization in two specific insertions—the flexible regulatory C-loop and the 190-202 β-harpin—promoting protein dimerization and the stabilization of a long-life charge transfer complex (CTC) that modulates its monomer-dimer equilibrium and its protein interaction network in healthy mitochondria. In this regard, here, we investigated the precise function of the β-hairpin in the AIF conformation landscape related to its redox mechanism, by analyzing the role played by W196, a key residue in the interaction of this motif with the regulatory C-loop. Mutations at W196 decrease the compactness and stability of the oxidized hAIF, indicating that the β-hairpin and C-loop coupling contribute to protein stability. Kinetic studies complemented with computational simulations reveal that W196 and the β-hairpin conformation modulate the low efficiency of hAIF as NADH oxidoreductase, contributing to configure its active site in a noncompetent geometry for hydride transfer and to stabilize the CTC state by enhancing the affinity for NAD+. Finally, the β-hairpin motif contributes to define the conformation of AIF's interaction surfaces with its physiological partners. These findings improve our understanding on the molecular basis of hAIF's cellular activities, a crucial aspect for clarifying its associated pathological mechanisms and developing new molecular therapies.
Collapse
|
15
|
High Frequency of AIFM1 Variants and Phenotype Progression of Auditory Neuropathy in a Chinese Population. Neural Plast 2020; 2020:5625768. [PMID: 32684920 PMCID: PMC7350177 DOI: 10.1155/2020/5625768] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 05/14/2020] [Accepted: 06/02/2020] [Indexed: 12/12/2022] Open
Abstract
To decipher the genotype-phenotype correlation of auditory neuropathy (AN) caused by AIFM1 variations, as well as the phenotype progression of these patients, exploring the potential molecular pathogenic mechanism of AN. A total of 36 families of individuals with AN (50 cases) with AIFM1 variations were recruited and identified by Sanger sequencing or next-generation sequencing; the participants included 30 patients from 16 reported families and 20 new cases. We found that AIFM1-positive cases accounted for 18.6% of late-onset AN cases. Of the 50 AN patients with AIFM1 variants, 45 were male and 5 were female. The hotspot variation of this gene was p.Leu344Phe, accounting for 36.1%. A total of 19 AIFM1 variants were reported in this study, including 7 novel ones. A follow-up study was performed on 30 previously reported AIFM1-positive subjects, 16 follow-up cases (53.3%) were included in this study, and follow-up periods were recorded from 1 to 23 years with average 9.75 ± 9.89 years. There was no hearing threshold increase during the short-term follow-up period (1-10 years), but the low-frequency and high-frequency hearing thresholds showed a significant increase with the prolongation of follow-up time. The speech discrimination score progressed gradually and significantly along with the course of the disease and showed a more serious decline, which was disproportionately worse than the pure tone threshold. In addition to the X-linked recessive inheritance pattern, the X-linked dominant inheritance pattern is also observed in AIFM1-related AN and affects females. In conclusion, we confirmed that AIFM1 is the primary related gene among late-onset AN cases, and the most common recurrent variant is p.Leu344Phe. Except for the X-linked recessive inheritance pattern, the X-linked dominant inheritance pattern is another probability of AIFM1-related AN, with females affected. Phenotypical features of AIFM1-related AN suggested that auditory dyssynchrony progressively worsened over time.
Collapse
|
16
|
AIF meets the CHCHD4/Mia40-dependent mitochondrial import pathway. Biochim Biophys Acta Mol Basis Dis 2020; 1866:165746. [PMID: 32105825 DOI: 10.1016/j.bbadis.2020.165746] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2019] [Revised: 02/19/2020] [Accepted: 02/20/2020] [Indexed: 02/06/2023]
Abstract
In the mitochondria of healthy cells, Apoptosis-Inducing factor (AIF) is required for the optimal functioning of the respiratory chain machinery, mitochondrial integrity, cell survival, and proliferation. In all analysed species, it was revealed that the downregulation or depletion of AIF provokes mainly the post-transcriptional loss of respiratory chain Complex I protein subunits. Recent progress in the field has revealed that AIF fulfils its mitochondrial pro-survival function by interacting physically and functionally with CHCHD4, the evolutionarily-conserved human homolog of yeast Mia40. The redox-regulated CHCHD4/Mia40-dependent import machinery operates in the intermembrane space of the mitochondrion and controls the import of a set of nuclear-encoded cysteine-motif carrying protein substrates. In addition to their participation in the biogenesis of specific respiratory chain protein subunits, CHCHD4/Mia40 substrates are also implicated in the control of redox regulation, antioxidant response, translation, lipid homeostasis and mitochondrial ultrastructure and dynamics. Here, we discuss recent insights on the AIF/CHCHD4-dependent protein import pathway and review current data concerning the CHCHD4/Mia40 protein substrates in metazoan. Recent findings and the identification of disease-associated mutations in AIF or in specific CHCHD4/Mia40 substrates have highlighted these proteins as potential therapeutic targets in a variety of human disorders.
Collapse
|
17
|
Kawarai T, Yamazaki H, Yamakami K, Tsukamoto-Miyashiro A, Kodama M, Rumore R, Caltagirone C, Nishino I, Orlacchio A. A novel AIFM1 missense mutation in a Japanese patient with ataxic sensory neuronopathy and hearing impairment. J Neurol Sci 2019; 409:116584. [PMID: 31783324 DOI: 10.1016/j.jns.2019.116584] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 11/16/2019] [Accepted: 11/18/2019] [Indexed: 11/18/2022]
Affiliation(s)
- Toshitaka Kawarai
- Department of Clinical Neuroscience, Tokushima University Graduate School, Tokushima, Japan.
| | - Hiroki Yamazaki
- Department of Clinical Neuroscience, Tokushima University Graduate School, Tokushima, Japan
| | - Kei Yamakami
- Department of Clinical Neuroscience, Tokushima University Graduate School, Tokushima, Japan
| | - Ai Tsukamoto-Miyashiro
- Neurology Service, Tokushima National Hospital, National Hospital Organization, Tokushima, Japan
| | - Mizuki Kodama
- Faculty of Medicine-Student Laboratory, Tokushima University Graduate School, Tokushima, Japan
| | - Roberto Rumore
- Laboratorio di Neurogenetica, Centro Europeo di Ricerca sul Cervello (CERC), Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Fondazione Santa Lucia, Rome, Italy
| | - Carlo Caltagirone
- Laboratorio di Neurologia Clinica e Comportamentale, IRCCS Fondazione Santa Lucia, Rome, Italy
| | - Ichizo Nishino
- Department of Neuromuscular Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo, Japan
| | - Antonio Orlacchio
- Laboratorio di Neurogenetica, Centro Europeo di Ricerca sul Cervello (CERC), Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Fondazione Santa Lucia, Rome, Italy; Dipartimento di Scienze Chirurgiche e Biomediche, Università di Perugia, Perugia, Italy
| |
Collapse
|
18
|
Schapira AHV. Progress in neurology 2017-2018. Eur J Neurol 2018; 25:1389-1397. [DOI: 10.1111/ene.13846] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- A. H. V. Schapira
- Department of Clinical and Movement Neurosciences; UCL Queen Square Institute of Neurology; London UK
| |
Collapse
|
19
|
Mitochondrial diseases caused by dysfunctional mitochondrial protein import. Biochem Soc Trans 2018; 46:1225-1238. [PMID: 30287509 DOI: 10.1042/bst20180239] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Revised: 08/20/2018] [Accepted: 08/31/2018] [Indexed: 12/18/2022]
Abstract
Mitochondria are essential organelles which perform complex and varied functions within eukaryotic cells. Maintenance of mitochondrial health and functionality is thus a key cellular priority and relies on the organelle's extensive proteome. The mitochondrial proteome is largely encoded by nuclear genes, and mitochondrial proteins must be sorted to the correct mitochondrial sub-compartment post-translationally. This essential process is carried out by multimeric and dynamic translocation and sorting machineries, which can be found in all four mitochondrial compartments. Interestingly, advances in the diagnosis of genetic disease have revealed that mutations in various components of the human import machinery can cause mitochondrial disease, a heterogenous and often severe collection of disorders associated with energy generation defects and a multisystem presentation often affecting the cardiovascular and nervous systems. Here, we review our current understanding of mitochondrial protein import systems in human cells and the molecular basis of mitochondrial diseases caused by defects in these pathways.
Collapse
|
20
|
Wischhof L, Gioran A, Sonntag-Bensch D, Piazzesi A, Stork M, Nicotera P, Bano D. A disease-associated Aifm1 variant induces severe myopathy in knockin mice. Mol Metab 2018; 13:10-23. [PMID: 29780003 PMCID: PMC6026322 DOI: 10.1016/j.molmet.2018.05.002] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Revised: 05/02/2018] [Accepted: 05/03/2018] [Indexed: 12/16/2022] Open
Abstract
OBJECTIVE Mutations in the AIFM1 gene have been identified in recessive X-linked mitochondrial diseases. Functional and molecular consequences of these pathogenic AIFM1 mutations have been poorly studied in vivo. METHODS/RESULTS Here we provide evidence that the disease-associated apoptosis-inducing factor (AIF) deletion arginine 201 (R200 in rodents) causes pathology in knockin mice. Within a few months, posttranslational loss of the mutant AIF protein induces severe myopathy associated with a lower number of cytochrome c oxidase-positive muscle fibers. At a later stage, Aifm1 (R200 del) knockin mice manifest peripheral neuropathy, but they do not show neurodegenerative processes in the cerebellum, as observed in age-matched hypomorphic Harlequin (Hq) mutant mice. Quantitative proteomic and biochemical data highlight common molecular signatures of mitochondrial diseases, including aberrant folate-driven one-carbon metabolism and sustained Akt/mTOR signaling. CONCLUSION Our findings indicate metabolic defects and distinct tissue-specific vulnerability due to a disease-causing AIFM1 mutation, with many pathological hallmarks that resemble those seen in patients.
Collapse
Affiliation(s)
- Lena Wischhof
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Anna Gioran
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | | | - Antonia Piazzesi
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Miriam Stork
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | | | - Daniele Bano
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany.
| |
Collapse
|
21
|
Wang B, Li X, Wang J, Liu L, Xie Y, Huang S, Pakhrin PS, Jin Q, Zhu C, Tang B, Niu Q, Zhang R. A novel AIFM1 mutation in a Chinese family with X-linked Charcot-Marie-Tooth disease type 4. Neuromuscul Disord 2018; 28:652-659. [PMID: 30031633 DOI: 10.1016/j.nmd.2018.05.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Revised: 04/05/2018] [Accepted: 05/20/2018] [Indexed: 11/16/2022]
Abstract
X-linked Charcot-Marie-Tooth disease type 4 (CMTX4), caused by AIFM1 (Apoptosis-Inducing Factor, Mitochondrion associated 1) mutations and associated with deafness and cognitive impairment, is a rare subtype of Charcot-Marie-Tooth disease. Here, we report a novel missense variant of AIFM1 in a X-linked recessive Chinese family with childhood-onset, slowly progressive, isolated axonal motor and sensory neuropathy. Calf magnetic resonance imaging revealed fatty infiltration and atrophy severely involving the muscles of peroneal compartment. Pathologies exhibited abnormal mitochondrial morphology and accumulation in axoplasm of nerve fiber and subsarcolemmal area of muscle. A hemizygous variant (c.513G>A, p.Met171Ile) in the family was identified and was classified as likely pathogenic according to the standards and guidelines of the American College of Medical Genetics and Genomics. Our report expands the genetic spectrum of diseases related to AIFM1 mutations and indicates that fatty infiltration and atrophy of muscles in the peroneal compartment may be a feature of CMTX4 in early stage.
Collapse
Affiliation(s)
- Binghao Wang
- Department of Neurology, The Third Xiangya Hospital, Central South University, Changsha, Hunan 410013, China
| | - Xiaobo Li
- Department of Neurology, The Third Xiangya Hospital, Central South University, Changsha, Hunan 410013, China
| | - Junpu Wang
- Department of Pathology, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China
| | - Lei Liu
- Health Management Center, The Third Xiangya Hospital, Central South University, Changsha, Hunan 410013, China
| | - Yongzhi Xie
- Department of Neurology, The Third Xiangya Hospital, Central South University, Changsha, Hunan 410013, China
| | - Shunxiang Huang
- Department of Neurology, The Third Xiangya Hospital, Central South University, Changsha, Hunan 410013, China
| | - Pukar Singh Pakhrin
- Department of Neurology, The Third Xiangya Hospital, Central South University, Changsha, Hunan 410013, China
| | - Qingwen Jin
- Department of Neurology, Sir Run Run Hospital, Nanjing Medical University, Nanjing, Jiangsu 210029, China
| | - Chunmei Zhu
- Department of Neurology, Xuyi County Hospital of T.C.M, Huaian, Jiangsu 211700, China
| | - Beisha Tang
- Key Laboratory of Hunan Province in Neurodegenerative Disorders, Central South University, Changsha, Hunan 410008, China
| | - Qi Niu
- Department of Neurology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, China.
| | - Ruxu Zhang
- Department of Neurology, The Third Xiangya Hospital, Central South University, Changsha, Hunan 410013, China.
| |
Collapse
|
22
|
Bano D, Prehn JHM. Apoptosis-Inducing Factor (AIF) in Physiology and Disease: The Tale of a Repented Natural Born Killer. EBioMedicine 2018; 30:29-37. [PMID: 29605508 PMCID: PMC5952348 DOI: 10.1016/j.ebiom.2018.03.016] [Citation(s) in RCA: 130] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Revised: 03/05/2018] [Accepted: 03/13/2018] [Indexed: 12/12/2022] Open
Abstract
Apoptosis-inducing factor (AIF) is a mitochondrial oxidoreductase that contributes to cell death programmes and participates in the assembly of the respiratory chain. Importantly, AIF deficiency leads to severe mitochondrial dysfunction, causing muscle atrophy and neurodegeneration in model organisms as well as in humans. The purpose of this review is to describe functions of AIF and AIF-interacting proteins as regulators of cell death and mitochondrial bioenergetics. We describe how AIF deficiency induces pathogenic processes that alter metabolism and ultimately compromise cellular homeostasis. We report the currently known AIFM1 mutations identified in humans and discuss the variability of AIFM1-related disorders in terms of onset, organ involvement and symptoms. Finally, we summarize how the study of AIFM1-linked pathologies may help to further expand our understanding of rare inherited forms of mitochondrial diseases. AIF is a mitochondrial NADH-dependent oxidoreductase. Nuclear translocation of AIF occurs during cell death and has been associated with human disorders. Under physiological settings, AIF participates to the biogenesis of the respiratory complexes. AIFM1 mutations have been identified in patients with impaired mitochondrial bioenergetics. Inherited AIFM1 mutations lead to a variety of clinical manifestations, including severe childhood-onset mitochondrial diseases.
Collapse
Affiliation(s)
- Daniele Bano
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany.
| | - Jochen H M Prehn
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, Dublin 2, Ireland; FutureNeuro Research Centre, Royal College of Surgeons in Ireland, Dublin 2, Ireland
| |
Collapse
|