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Pérez MJ, Ibarra-García-Padilla R, Tang M, Porter GA, Johnson GVW, Quintanilla RA. Caspase-3 cleaved tau impairs mitochondrial function through the opening of the mitochondrial permeability transition pore. Biochim Biophys Acta Mol Basis Dis 2024; 1870:166898. [PMID: 37774936 DOI: 10.1016/j.bbadis.2023.166898] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Revised: 09/10/2023] [Accepted: 09/24/2023] [Indexed: 10/01/2023]
Abstract
Mitochondrial dysfunction is a significant factor in the development of Alzheimer's disease (AD). Previous studies have demonstrated that the expression of tau cleaved at Asp421 by caspase-3 leads to mitochondrial abnormalities and bioenergetic impairment. However, the underlying mechanism behind these alterations and their impact on neuronal function remains unknown. To investigate the mechanism behind mitochondrial dysfunction caused by this tau form, we used transient transfection and pharmacological approaches in immortalized cortical neurons and mouse primary hippocampal neurons. We assessed mitochondrial morphology and bioenergetics function after expression of full-length tau and caspase-3-cleaved tau. We also evaluated the mitochondrial permeability transition pore (mPTP) opening and its conformation as a possible mechanism to explain mitochondrial impairment induced by caspase-3 cleaved tau. Our studies showed that pharmacological inhibition of mPTP by cyclosporine A (CsA) prevented all mitochondrial length and bioenergetics abnormalities in neuronal cells expressing caspase-3 cleaved tau. Neuronal cells expressing caspase-3-cleaved tau showed sustained mPTP opening which is mostly dependent on cyclophilin D (CypD) protein expression. Moreover, the impairment of mitochondrial length and bioenergetics induced by caspase-3-cleaved tau were prevented in hippocampal neurons obtained from CypD knock-out mice. Interestingly, previous studies using these mice showed a prevention of mPTP opening and a reduction of mitochondrial failure and neurodegeneration induced by AD. Therefore, our findings showed that caspase-3-cleaved tau negatively impacts mitochondrial bioenergetics through mPTP activation, highlighting the importance of this channel and its regulatory protein, CypD, in the neuronal damage induced by tau pathology in AD.
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Affiliation(s)
- María José Pérez
- Laboratory of Neurodegenerative Diseases, Centro de Investigaciones Biomédicas, Universidad Autónoma de Chile, Santiago, Chile
| | - Rodrigo Ibarra-García-Padilla
- Laboratory of Neurodegenerative Diseases, Centro de Investigaciones Biomédicas, Universidad Autónoma de Chile, Santiago, Chile
| | - Maoping Tang
- Department of Anesthesiology, University of Rochester Medical Center, New York, USA
| | - George A Porter
- Department of Pediatrics, University of Rochester Medical Center, New York, USA
| | - Gail V W Johnson
- Department of Anesthesiology, University of Rochester Medical Center, New York, USA
| | - Rodrigo A Quintanilla
- Laboratory of Neurodegenerative Diseases, Centro de Investigaciones Biomédicas, Universidad Autónoma de Chile, Santiago, Chile.
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Chen W, Zhao H, Li Y. Mitochondrial dynamics in health and disease: mechanisms and potential targets. Signal Transduct Target Ther 2023; 8:333. [PMID: 37669960 PMCID: PMC10480456 DOI: 10.1038/s41392-023-01547-9] [Citation(s) in RCA: 43] [Impact Index Per Article: 43.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 05/29/2023] [Accepted: 06/24/2023] [Indexed: 09/07/2023] Open
Abstract
Mitochondria are organelles that are able to adjust and respond to different stressors and metabolic needs within a cell, showcasing their plasticity and dynamic nature. These abilities allow them to effectively coordinate various cellular functions. Mitochondrial dynamics refers to the changing process of fission, fusion, mitophagy and transport, which is crucial for optimal function in signal transduction and metabolism. An imbalance in mitochondrial dynamics can disrupt mitochondrial function, leading to abnormal cellular fate, and a range of diseases, including neurodegenerative disorders, metabolic diseases, cardiovascular diseases and cancers. Herein, we review the mechanism of mitochondrial dynamics, and its impacts on cellular function. We also delve into the changes that occur in mitochondrial dynamics during health and disease, and offer novel perspectives on how to target the modulation of mitochondrial dynamics.
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Affiliation(s)
- Wen Chen
- Department of Medical Oncology, Chongqing University Cancer Hospital, Chongqing, 400030, China
| | - Huakan Zhao
- Department of Medical Oncology, Chongqing University Cancer Hospital, Chongqing, 400030, China.
| | - Yongsheng Li
- Department of Medical Oncology, Chongqing University Cancer Hospital, Chongqing, 400030, China.
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3
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Liu C, Liu Y, Ma B, Zhou M, Zhao X, Fu X, Kan S, Hu W, Zhu R. Mitochondrial regulatory mechanisms in spinal cord injury: A narrative review. Medicine (Baltimore) 2022; 101:e31930. [PMID: 36401438 PMCID: PMC9678589 DOI: 10.1097/md.0000000000031930] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
Spinal cord injury is a severe central nervous system injury that results in the permanent loss of motor, sensory, and autonomic functions below the level of injury with limited recovery. The pathological process of spinal cord injury includes primary and secondary injuries, characterized by a progressive cascade. Secondary injury impairs the ability of the mitochondria to maintain homeostasis and leads to calcium overload, excitotoxicity, and oxidative stress, further exacerbating the injury. The defective mitochondrial function observed in these pathologies accelerates neuronal cell death and inhibits regeneration. Treatment of spinal cord injury by preserving mitochondrial biological function is a promising, although still underexplored, therapeutic strategy. This review aimed to explore mitochondrial-based therapeutic advances after spinal cord injury. Specifically, it briefly describes the characteristics of spinal cord injury. It then broadly discusses the drugs used to protect the mitochondria (e.g., cyclosporine A, acetyl-L-carnitine, and alpha-tocopherol), phenomena associated with mitochondrial damage processes (e.g., mitophagy, ferroptosis, and cuproptosis), mitochondrial transplantation for nerve cell regeneration, and innovative mitochondrial combined protection therapy.
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Affiliation(s)
- Chengjiang Liu
- Department of Spine Surgery, Tianjin Union Medical Center Tianjin, Tianjin, China
| | - Yidong Liu
- Department of Spine Surgery, Tianjin Union Medical Center Tianjin, Tianjin, China
| | - Boyuan Ma
- Department of Spine Surgery, Tianjin Union Medical Center Tianjin, Tianjin, China
| | - Mengmeng Zhou
- Department of Spine Surgery, Tianjin Union Medical Center Tianjin, Tianjin, China
| | - Xinyan Zhao
- Department of Spine Surgery, Tianjin Union Medical Center Tianjin, Tianjin, China
| | - Xuanhao Fu
- Department of Spine Surgery, Tianjin Union Medical Center Tianjin, Tianjin, China
| | - Shunli Kan
- Department of Spine Surgery, Tianjin Union Medical Center Tianjin, Tianjin, China
| | - Wei Hu
- Department of Spine Surgery, Tianjin Union Medical Center Tianjin, Tianjin, China
| | - Rusen Zhu
- Department of Spine Surgery, Tianjin Union Medical Center Tianjin, Tianjin, China
- *Correspondence: Rusen Zhu, Department of Spine Surgery, Tianjin Union Medical Center190jieyuan Road, Honggiao District, Tianjin 300121, China (e-mail: )
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4
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Aung LHH, Jumbo JCC, Wang Y, Li P. Therapeutic potential and recent advances on targeting mitochondrial dynamics in cardiac hypertrophy: A concise review. MOLECULAR THERAPY. NUCLEIC ACIDS 2021; 25:416-443. [PMID: 34484866 PMCID: PMC8405900 DOI: 10.1016/j.omtn.2021.06.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Pathological cardiac hypertrophy begins as an adaptive response to increased workload; however, sustained hemodynamic stress will lead it to maladaptation and eventually cardiac failure. Mitochondria, being the powerhouse of the cells, can regulate cardiac hypertrophy in both adaptive and maladaptive phases; they are dynamic organelles that can adjust their number, size, and shape through a process called mitochondrial dynamics. Recently, several studies indicate that promoting mitochondrial fusion along with preventing mitochondrial fission could improve cardiac function during cardiac hypertrophy and avert its progression toward heart failure. However, some studies also indicate that either hyperfusion or hypo-fission could induce apoptosis and cardiac dysfunction. In this review, we summarize the recent knowledge regarding the effects of mitochondrial dynamics on the development and progression of cardiac hypertrophy with particular emphasis on the regulatory role of mitochondrial dynamics proteins through the genetic, epigenetic, and post-translational mechanisms, followed by discussing the novel therapeutic strategies targeting mitochondrial dynamic pathways.
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Affiliation(s)
- Lynn Htet Htet Aung
- Center for Molecular Genetics, Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao 266021, China.,Center for Bioinformatics, Institute for Translational Medicine, School of Basic Science, College of Medicine, Qingdao University, Qingdao 266021, China
| | - Juan Carlos Cueva Jumbo
- School of Preclinical Medicine, Nanobody Research Center, Guangxi Medical University, Nanning 530021, China
| | - Yin Wang
- Center for Molecular Genetics, Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao 266021, China
| | - Peifeng Li
- Center for Molecular Genetics, Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao 266021, China.,Center for Bioinformatics, Institute for Translational Medicine, School of Basic Science, College of Medicine, Qingdao University, Qingdao 266021, China
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de Freitas JL, Rezende Filho FM, Sallum JM, França MC, Pedroso JL, Barsottini OG. Ophthalmological changes in hereditary spastic paraplegia and other genetic diseases with spastic paraplegia. J Neurol Sci 2020; 409:116620. [DOI: 10.1016/j.jns.2019.116620] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Revised: 11/16/2019] [Accepted: 12/05/2019] [Indexed: 01/05/2023]
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Ham M, Han J, Osann K, Smith M, Kimonis V. Meta-analysis of genotype-phenotype analysis of OPA1 mutations in autosomal dominant optic atrophy. Mitochondrion 2018; 46:262-269. [PMID: 30165240 DOI: 10.1016/j.mito.2018.07.006] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Revised: 05/20/2018] [Accepted: 07/31/2018] [Indexed: 01/21/2023]
Abstract
Autosomal Dominant Optic Atrophy (ADOA) is a neuro-ophthalmic disease characterized by progressive bilateral vision loss, pallor of the optic disc, central vision loss, and impairment of color vision. Additionally, a small percentage of patients experience hearing loss and ataxia, while recent studies suggest disruption of cardiac and neuromuscular functions. In order to obtain a better understanding of the genotype-phenotype correlation of the various mutations in the optic atrophy 1 (OPA1) gene, we obtained both clinical and genetic information of ADOA patients from published reports. We conducted a systematic review of published OPA1 literature and identified 408 individuals with confirmed OPA1 mutations, 120 of whom reported extra-ocular (ADOA 'plus') manifestations through their descriptions of visual and multi-systemic symptoms. Our results show that there is a significant variation in frequency of the specific exons involved between the ADOA classic and ADOA 'plus' patients. Classic ADOA groups were more likely to have mutations in exon 8 and 9, while ADOA 'plus' groups were more likely to have mutations in exons 14, 15 and 17. Additional comparisons revealed significant differences between mutation types/domains and specific ADOA 'plus' manifestations. We also found that individuals with maternally inherited OPA1 mutations were significantly more likely to develop 'plus' manifestations than those with paternally inherited mutations. Overall, this study provides novel information regarding genotype-phenotype correlations of ADOA which warrants additional recommendations added to the current clinical management of ADOA patients.
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Affiliation(s)
- Michelle Ham
- Division of Genetics and Genomic Medicine, Department of Pediatrics, University of California, Irvine, CA, USA
| | - Julia Han
- Division of Genetics and Genomic Medicine, Department of Pediatrics, University of California, Irvine, CA, USA
| | - Kathryn Osann
- Department of Medicine, Division of Hematology-Oncology, University of California, Irvine, CA, USA
| | - Moyra Smith
- Division of Genetics and Genomic Medicine, Department of Pediatrics, University of California, Irvine, CA, USA
| | - Virginia Kimonis
- Division of Genetics and Genomic Medicine, Department of Pediatrics, University of California, Irvine, CA, USA.
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7
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Li H, Jones EM, Li H, Yang L, Sun Z, Yuan Z, Chen R, Dong F, Sui R. Clinical and genetic features of eight Chinese autosomal-dominant optic atrophy pedigrees with six novel OPA1 pathogenic variants. Ophthalmic Genet 2018; 39:569-576. [PMID: 29952689 DOI: 10.1080/13816810.2018.1466337] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
BACKGROUND Autosomal-dominant optic atrophy (ADOA) is one of the most common types of inherited optic atrophy. We identify OPA1 pathogenic variants and assess the clinical features of a cohort of Chinese ADOA patients Materials and Methods: Detailed clinical evaluations were performed and genomic DNA was extracted from peripheral blood for all the participants. Sanger sequencing was used to analyze all exons and exon/intron junctions of OPA1 for eight pedigrees. Target exome capture plus next-generation sequencing (NGS) were applied for one atypical family with photophobia. Reverse transcription polymerase chain reaction was carried out to further characterize the mRNA change of selected splicing alteration. RESULTS All 17 patients had impaired vision and optic-disk pallor; however, the clinical severity varied markedly. Two patients complicated with hearing loss. Six novel and two reported pathogenic variants in OPA1 (GenBank Accession No. NM_130837.2) were identified including four nonsynonymous variants (c.2400T > G, c.1468T > C, c.1567A > G and c.1466T > C), two splicing variants (c.2984-1_2986delGAGA and c.2983 + 5G > A), one small deletion (c.2960_2968delGCGTTCAAC), and one small insertion (c.3009_3010insA). RNA analysis revealed the splicing variant c.2984-1_2986delGAGA caused small deletion of mRNA (r.2983_2988del). CONCLUSIONS ADOA patients presented variable clinical manifestations. Novel OPA1 pathogenic variants are the main genetic defect for Chinese ADOA cases. NGS may be a useful molecular testing tool for atypical ADOA.
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Affiliation(s)
- Huajin Li
- a Department of Ophthalmology , Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences , Beijing , China
| | - Evan M Jones
- b Department of Molecular and Human Genetics , Baylor College of Medicine , Houston , TX , USA
| | - Hui Li
- a Department of Ophthalmology , Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences , Beijing , China
| | - Lizhu Yang
- a Department of Ophthalmology , Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences , Beijing , China
| | - Zixi Sun
- a Department of Ophthalmology , Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences , Beijing , China
| | - Zhisheng Yuan
- a Department of Ophthalmology , Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences , Beijing , China
| | - Rui Chen
- b Department of Molecular and Human Genetics , Baylor College of Medicine , Houston , TX , USA
| | - Fangtian Dong
- a Department of Ophthalmology , Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences , Beijing , China
| | - Ruifang Sui
- a Department of Ophthalmology , Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences , Beijing , China
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8
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The mitochondrial dynamics in cancer and immune-surveillance. Semin Cancer Biol 2017; 47:29-42. [DOI: 10.1016/j.semcancer.2017.06.007] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Revised: 06/09/2017] [Accepted: 06/15/2017] [Indexed: 12/15/2022]
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9
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Scholpa NE, Schnellmann RG. Mitochondrial-Based Therapeutics for the Treatment of Spinal Cord Injury: Mitochondrial Biogenesis as a Potential Pharmacological Target. J Pharmacol Exp Ther 2017; 363:303-313. [PMID: 28935700 PMCID: PMC5676296 DOI: 10.1124/jpet.117.244806] [Citation(s) in RCA: 77] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Accepted: 09/20/2017] [Indexed: 12/24/2022] Open
Abstract
Spinal cord injury (SCI) is characterized by an initial trauma followed by a progressive cascade of damage referred to as secondary injury. A hallmark of secondary injury is vascular disruption leading to vasoconstriction and decreased oxygen delivery, which directly reduces the ability of mitochondria to maintain homeostasis and leads to loss of ATP-dependent cellular functions, calcium overload, excitotoxicity, and oxidative stress, further exacerbating injury. Restoration of mitochondria dysfunction during the acute phases of secondary injury after SCI represents a potentially effective therapeutic strategy. This review discusses the past and present pharmacological options for the treatment of SCI as well as current research on mitochondria-targeted approaches. Increased antioxidant activity, inhibition of the mitochondrial permeability transition, alternate energy sources, and manipulation of mitochondrial morphology are among the strategies under investigation. Unfortunately, many of these tactics address single aspects of mitochondrial dysfunction, ultimately proving largely ineffective. Therefore, this review also examines the unexplored therapeutic efficacy of pharmacological enhancement of mitochondrial biogenesis, which has the potential to more comprehensively improve mitochondrial function after SCI.
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Affiliation(s)
- Natalie E Scholpa
- Department of Pharmacology and Toxicology, College of Pharmacy, University of Arizona, Tucson, Arizona (N.E.S., R.G.S.); and Southern Arizona VA Health Care System, Tucson, Arizona (R.G.S.)
| | - Rick G Schnellmann
- Department of Pharmacology and Toxicology, College of Pharmacy, University of Arizona, Tucson, Arizona (N.E.S., R.G.S.); and Southern Arizona VA Health Care System, Tucson, Arizona (R.G.S.)
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10
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Ścieżyńska A, Ruszkowska E, Szulborski K, Rydz K, Wierzbowska J, Kosińska J, Rękas M, Płoski R, Szaflik JP, Ołdak M. Processing of OPA1 with a novel N-terminal mutation in patients with autosomal dominant optic atrophy: Escape from nonsense-mediated decay. PLoS One 2017; 12:e0183866. [PMID: 28841713 PMCID: PMC5571936 DOI: 10.1371/journal.pone.0183866] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2017] [Accepted: 08/11/2017] [Indexed: 12/02/2022] Open
Abstract
Autosomal Dominant Optic Atrophy (ADOA) is the most common dominantly inherited optic neuropathy. In the majority of patients it is caused by OPA1 mutations and those predicted to introduce a premature termination codon (PTC) are frequently detected. Transcripts containing PTC may be degraded by nonsense-mediated mRNA decay (NMD), however very little is known about an effect of OPA1 mutations on NMD activation. Here, using a combination of linkage analysis and DNA sequencing, we have identified a novel c.91C>T OPA1 mutation with a putative premature stop codon (Q31*), which segregated with ADOA in two Polish families. At the mRNA level we found no changes in the amount of OPA1 transcript among mutation carriers vs. non-carriers. Specific allele quantification revealed a considerable level of the OPA1 mutant transcript. Our study identifies a novel pathogenic OPA1 mutation and shows that it is located in the transcript region not prone for NMD activation. The data emphasizes the importance of analyzing how mutated genes are being processed in the cell. This gives an insight into the molecular mechanism of a genetic disease and promotes development of innovative therapeutic approaches.
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Affiliation(s)
- Aneta Ścieżyńska
- Department of Histology and Embryology, Medical University of Warsaw, Warsaw, Poland
| | - Ewelina Ruszkowska
- Department of Histology and Embryology, Medical University of Warsaw, Warsaw, Poland
| | - Kamil Szulborski
- Department of Ophthalmology, Medical University of Warsaw, Warsaw, Poland
| | - Katarzyna Rydz
- Department of Histology and Embryology, Medical University of Warsaw, Warsaw, Poland
| | - Joanna Wierzbowska
- Department of Ophthalmology, Military Institute of Medicine, Warsaw, Poland
| | - Joanna Kosińska
- Department of Medical Genetics, Medical University of Warsaw, Warsaw, Poland
| | - Marek Rękas
- Department of Ophthalmology, Military Institute of Medicine, Warsaw, Poland
| | - Rafał Płoski
- Department of Medical Genetics, Medical University of Warsaw, Warsaw, Poland
| | | | - Monika Ołdak
- Department of Histology and Embryology, Medical University of Warsaw, Warsaw, Poland
- * E-mail:
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11
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Gaier ED, Boudreault K, Nakata I, Janessian M, Skidd P, DelBono E, Allen KF, Pasquale LR, Place E, Cestari DM, Stacy RC, Rizzo JF, Wiggs JL. Diagnostic genetic testing for patients with bilateral optic neuropathy and comparison of clinical features according to OPA1 mutation status. Mol Vis 2017; 23:548-560. [PMID: 28848318 PMCID: PMC5561143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2017] [Accepted: 08/08/2017] [Indexed: 10/26/2022] Open
Abstract
PURPOSE Inherited optic neuropathy is genetically heterogeneous, and genetic testing has an important role in risk assessment and counseling. The purpose of this study is to determine the prevalence and spectrum of mutations in a group of patients referred for genetic testing to a tertiary center in the United States. In addition, we compared the clinical features of patients with and without mutations in OPA1, the gene most commonly involved in dominantly inherited optic atrophy. METHODS Clinical data and genetic testing results were reviewed for 74 unrelated, consecutive patients referred with a history of insidious, relatively symmetric, bilateral visual loss secondary to an optic neuropathy. Patients were evaluated for disease-causing variants in OPA1, OPA3, WFS1, and the entire mitochondrial genome with DNA sequencing and copy number variation (CNV) testing. RESULTS Pathogenic DNA variants were found in 25 cases, with the majority (24 patients) located in OPA1. Demographics, clinical history, and clinical features for the group of patients with mutations in OPA1 were compared to those without disease-causing variants. Compared to the patients without mutations, cases with mutations in OPA1 were more likely to have a family history of optic nerve disease (p = 0.027); however, 30.4% of patients without a family history of disease also had mutations in OPA1. OPA1 mutation carriers had less severe mean deviation and pattern standard deviation on automated visual field testing than patients with optic atrophy without mutations in OPA1 (p<0.005). Other demographic and ocular features were not statistically significantly different between the two groups, including the fraction of patients with central scotomas (42.9% of OPA1 mutation positive and 66.0% of OPA1 mutation negative). CONCLUSIONS Genetic testing identified disease-causing mutations in 34% of referred cases, with the majority of these in OPA1. Patients with mutations in OPA1 were more likely to have a family history of disease; however, 30.4% of patients without a family history were also found to have an OPA1 mutation. This observation, as well as similar frequencies of central scotomas in the groups with and without mutations in OPA1, underscores the need for genetic testing to establish an OPA1 genetic diagnosis.
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Affiliation(s)
- Eric D. Gaier
- Department of Ophthalmology, Harvard Medical School, Massachusetts Eye and Ear Infirmary Boston, MA
| | - Katherine Boudreault
- Department of Ophthalmology, Harvard Medical School, Massachusetts Eye and Ear Infirmary Boston, MA
| | - Isao Nakata
- Department of Ophthalmology, Harvard Medical School, Massachusetts Eye and Ear Infirmary Boston, MA
| | - Maria Janessian
- Department of Ophthalmology, Harvard Medical School, Massachusetts Eye and Ear Infirmary Boston, MA
| | - Philip Skidd
- Departments of Ophthalmology and Neurology, University of Vermont College of Medicine, Burlington, MA
| | - Elizabeth DelBono
- Department of Ophthalmology, Harvard Medical School, Massachusetts Eye and Ear Infirmary Boston, MA
| | - Keri F. Allen
- Department of Ophthalmology, Harvard Medical School, Massachusetts Eye and Ear Infirmary Boston, MA
| | - Louis R. Pasquale
- Department of Ophthalmology, Harvard Medical School, Massachusetts Eye and Ear Infirmary Boston, MA,Channing Division of Network Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA
| | - Emily Place
- Department of Ophthalmology, Harvard Medical School, Massachusetts Eye and Ear Infirmary Boston, MA
| | - Dean M. Cestari
- Department of Ophthalmology, Harvard Medical School, Massachusetts Eye and Ear Infirmary Boston, MA
| | - Rebecca C. Stacy
- Department of Ophthalmology, Harvard Medical School, Massachusetts Eye and Ear Infirmary Boston, MA
| | - Joseph F. Rizzo
- Department of Ophthalmology, Harvard Medical School, Massachusetts Eye and Ear Infirmary Boston, MA
| | - Janey L. Wiggs
- Department of Ophthalmology, Harvard Medical School, Massachusetts Eye and Ear Infirmary Boston, MA
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The Interplay between Oncogenic Signaling Networks and Mitochondrial Dynamics. Antioxidants (Basel) 2017; 6:antiox6020033. [PMID: 28513539 PMCID: PMC5488013 DOI: 10.3390/antiox6020033] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2017] [Revised: 05/10/2017] [Accepted: 05/12/2017] [Indexed: 12/18/2022] Open
Abstract
Mitochondria are dynamic organelles that alter their organization in response to a variety of cellular cues. Mitochondria are central in many biologic processes, such as cellular bioenergetics and apoptosis, and mitochondrial network morphology can contribute to those physiologic processes. Some of the biologic processes that are in part governed by mitochondria are also commonly deregulated in cancers. Furthermore, patient tumor samples from a variety of cancers have revealed that mitochondrial dynamics machinery may be deregulated in tumors. In this review, we will discuss how commonly mutated oncogenes and their downstream effector pathways regulate the mitochondrial dynamics machinery to promote changes in mitochondrial morphology as well as the physiologic consequences of altered mitochondrial morphology for tumorigenic growth.
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13
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Mitochondrial dynamics as regulators of cancer biology. Cell Mol Life Sci 2017; 74:1999-2017. [PMID: 28083595 DOI: 10.1007/s00018-016-2451-3] [Citation(s) in RCA: 154] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Revised: 12/22/2016] [Accepted: 12/29/2016] [Indexed: 02/07/2023]
Abstract
Mitochondria are dynamic organelles that supply energy required to drive key cellular processes, such as survival, proliferation, and migration. Critical to all of these processes are changes in mitochondrial architecture, a mechanical mechanism encompassing both fusion and fragmentation (fission) of the mitochondrial network. Changes to mitochondrial shape, size, and localization occur in a regulated manner to maintain energy and metabolic homeostasis, while deregulation of mitochondrial dynamics is associated with the onset of metabolic dysfunction and disease. In cancers, oncogenic signals that drive excessive proliferation, increase intracellular stress, and limit nutrient supply are all able to alter the bioenergetic and biosynthetic requirements of cancer cells. Consequently, mitochondrial function and shape rapidly adapt to these hostile conditions to support cancer cell proliferation and evade activation of cell death programs. In this review, we will discuss the molecular mechanisms governing mitochondrial dynamics and integrate recent insights into how changes in mitochondrial shape affect cellular migration, differentiation, apoptosis, and opportunities for the development of novel targeted cancer therapies.
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15
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Zhang L, Shi W, Song L, Zhang X, Cheng L, Wang Y, Ge X, Li W, Zhang W, Min Q, Jin ZB, Qu J, Gu F. A recurrent deletion mutation in OPA1 causes autosomal dominant optic atrophy in a Chinese family. Sci Rep 2014; 4:6936. [PMID: 25374051 PMCID: PMC4221781 DOI: 10.1038/srep06936] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Accepted: 10/20/2014] [Indexed: 11/23/2022] Open
Abstract
Autosomal dominant optic atrophy (ADOA) is the most frequent form of hereditary optic neuropathy and occurs due to the degeneration of the retinal ganglion cells. To identify the genetic defect in a family with putative ADOA, we performed capture next generation sequencing (CNGS) to screen known retinal disease genes. However, six exons failed to be sequenced by CNGS in optic atrophy 1 gene (OPA1). Sequencing of those exons identified a 4 bp deletion mutation (c.2983-1_2985del) in OPA1. Furthermore, we sequenced the transcripts of OPA1 from the patient skin fibroblasts and found there is six-nucleotide deletion (c.2984-c.2989, AGAAAG). Quantitative-PCR and Western blotting showed that OPA1 mRNA and its protein expression have no obvious difference between patient skin fibroblast and control. The analysis of protein structure by molecular modeling suggests that the mutation may change the structure of OPA1 by formation of an alpha helix protruding into an existing pocket. Taken together, we identified an OPA1 mutation in a family with ADOA by filling the missing CNGS data. We also showed that this mutation affects the structural intactness of OPA1. It provides molecular insights for clinical genetic diagnosis and treatment of optic atrophy.
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Affiliation(s)
- Liping Zhang
- School of Ophthalmology and Optometry, Eye Hospital, Wenzhou Medical University, State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health and Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry, Wenzhou, Zhejiang 325027 China
| | - Wei Shi
- National Key Discipline of Pediatrics, Ministry of Education, Department of Ophthalmology, Beijing Children's Hospital, Capital Medical University, Beijing 100045, China
| | - Liming Song
- Department of Urology, Beijing Chao-yang Hospital, Capital Medical University, Beijing 100020 China
| | - Xiao Zhang
- School of Ophthalmology and Optometry, Eye Hospital, Wenzhou Medical University, State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health and Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry, Wenzhou, Zhejiang 325027 China
| | - Lulu Cheng
- School of Ophthalmology and Optometry, Eye Hospital, Wenzhou Medical University, State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health and Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry, Wenzhou, Zhejiang 325027 China
| | - Yanfang Wang
- Zhejiang Key Laboratory of Medical Genetics, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang 325035 China
| | - Xianglian Ge
- School of Ophthalmology and Optometry, Eye Hospital, Wenzhou Medical University, State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health and Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry, Wenzhou, Zhejiang 325027 China
| | - Wei Li
- Zhejiang Key Laboratory of Medical Genetics, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang 325035 China
| | - Wei Zhang
- Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101 China
| | - Qingjie Min
- Institute of Genomic Medicine, Wenzhou Medical University, Wenzhou, Zhejiang 325027 China
| | - Zi-Bing Jin
- School of Ophthalmology and Optometry, Eye Hospital, Wenzhou Medical University, State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health and Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry, Wenzhou, Zhejiang 325027 China
| | - Jia Qu
- School of Ophthalmology and Optometry, Eye Hospital, Wenzhou Medical University, State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health and Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry, Wenzhou, Zhejiang 325027 China
| | - Feng Gu
- School of Ophthalmology and Optometry, Eye Hospital, Wenzhou Medical University, State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health and Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry, Wenzhou, Zhejiang 325027 China
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First cases of dominant optic atrophy in Saudi Arabia: report of two novel OPA1 mutations. J Neuroophthalmol 2013; 33:349-53. [PMID: 24051421 DOI: 10.1097/wno.0b013e31829ffb9a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Fifty to 60% of patients with dominant optic atrophy (DOA) have mutations of the OPA1 gene, which encodes dynamin-related GTPase, a protein of the internal mitochondrial membrane. To date, more than 200 OPA1 mutations in the OPA1 gene have been described. However, DOA is genetically heterogeneous with certain families linked to other chromosomal loci, that is, OPA3, OPA4, OPA5, and OPA7. METHODS This study describes a clinical series of 40 patients from Saudi Arabia with a positive DOA phenotype (i.e., decreased visual acuity during the first 2 decades of life, temporal or global optic disc pallor, and absence of other neurological or ophthalmological diseases that could explain the optic neuropathy) who underwent molecular genetic testing for OPA1 (and, in some cases, for OPA3). RESULTS This study describes for the first time 4 OPA1 mutations in DOA patients from Saudi Arabia, including 2 novel OPA1 mutations in 2 different patients. CONCLUSION The question remains whether certain patients in Saudi Arabia with a clearly defined DOA phenotype may be due to mutations in chromosomal loci other than OPA1 and OPA3. It is likely that genetic alterations associated with different loci will be discovered in the future.
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Abstract
Mitochondrial diseases involve the respiratory chain, which is under the dual control of nuclear and mitochondrial DNA (mtDNA). The complexity of mitochondrial genetics provides one explanation for the clinical heterogeneity of mitochondrial diseases, but our understanding of disease pathogenesis remains limited. Classification of Mendelian mitochondrial encephalomyopathies has been laborious, but whole-exome sequencing studies have revealed unexpected molecular aetiologies for both typical and atypical mitochondrial disease phenotypes. Mendelian mitochondrial defects can affect five components of mitochondrial biology: subunits of respiratory chain complexes (direct hits); mitochondrial assembly proteins; mtDNA translation; phospholipid composition of the inner mitochondrial membrane; or mitochondrial dynamics. A sixth category-defects of mtDNA maintenance-combines features of Mendelian and mitochondrial genetics. Genetic defects in mitochondrial dynamics are especially important in neurology as they cause optic atrophy, hereditary spastic paraplegia, and Charcot-Marie-Tooth disease. Therapy is inadequate and mostly palliative, but promising new avenues are being identified. Here, we review current knowledge on the genetics and pathogenesis of the six categories of mitochondrial disorders outlined above, focusing on their salient clinical manifestations and highlighting novel clinical entities. An outline of diagnostic clues for the various forms of mitochondrial disease, as well as potential therapeutic strategies, is also discussed.
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Rahn JJ, Stackley KD, Chan SSL. Opa1 is required for proper mitochondrial metabolism in early development. PLoS One 2013; 8:e59218. [PMID: 23516612 PMCID: PMC3597633 DOI: 10.1371/journal.pone.0059218] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2012] [Accepted: 02/12/2013] [Indexed: 12/03/2022] Open
Abstract
Opa1 catalyzes fusion of inner mitochondrial membranes and formation of the cristae. OPA1 mutations in humans lead to autosomal dominant optic atrophy. OPA1 knockout mice lose viability around embryonic day 9 from unknown reasons, indicating that OPA1 is essential for embryonic development. Zebrafish are an attractive model for studying vertebrate development and have been used for many years to describe developmental events that are difficult or impractical to view in mammalian models. In this study, Opa1 was successfully depleted in zebrafish embryos using antisense morpholinos, which resulted in disrupted mitochondrial morphology. Phenotypically, these embryos exhibited abnormal blood circulation and heart defects, as well as small eyes and small pectoral fin buds. Additionally, startle response was reduced and locomotor activity was impaired. Furthermore, Opa1 depletion caused bioenergetic defects, without impairing mitochondrial efficiency. In response to mitochondrial dysfunction, a transient upregulation of the master regulator of mitochondrial biogenesis, pgc1a, was observed. These results not only reveal a new Opa1-associated phenotype in a vertebrate model system, but also further elucidates the absolute requirement of Opa1 for successful vertebrate development.
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Affiliation(s)
- Jennifer J Rahn
- Department of Drug Discovery and Biomedical Sciences, Medical University of South Carolina, Charleston, South Carolina, United States of America
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