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Ulhaq ZS, Bittencourt GB, Soraya GV, Istifiani LA, Pamungkas SA, Ogino Y, Nurputra DK, Tse WKF. Association between glaucoma susceptibility with combined defects in mitochondrial oxidative phosphorylation and fatty acid beta oxidation. Mol Aspects Med 2024; 96:101238. [PMID: 38215610 DOI: 10.1016/j.mam.2023.101238] [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: 06/28/2023] [Revised: 11/08/2023] [Accepted: 11/28/2023] [Indexed: 01/14/2024]
Abstract
Glaucoma is one of the leading causes of visual impairment and blindness worldwide, and is characterized by the progressive damage of retinal ganglion cells (RGCs) and the atrophy of the optic nerve head (ONH). The exact cause of RGC loss and optic nerve damage in glaucoma is not fully understood. The high energy demands of these cells imply a higher sensitivity to mitochondrial defects. Moreover, it has been postulated that the optic nerve is vulnerable towards damage from oxidative stress and mitochondrial dysfunction. To investigate this further, we conducted a pooled analysis of mitochondrial variants related to energy production, specifically focusing on oxidative phosphorylation (OXPHOS) and fatty acid β-oxidation (FAO). Our findings revealed that patients carrying non-synonymous (NS) mitochondrial DNA (mtDNA) variants within the OXPHOS complexes had an almost two-fold increased risk of developing glaucoma. Regarding FAO, our results demonstrated that longer-chain acylcarnitines (AC) tended to decrease, while shorter-chain AC tended to increase in patients with glaucoma. Furthermore, we observed that the knocking down cpt1a (a key rate-limiting enzyme involved in FAO) in zebrafish induced a degenerative process in the optic nerve and RGC, which resembled the characteristics observed in glaucoma. In conclusion, our study provides evidence that genes encoding mitochondrial proteins involved in energy metabolisms, such as OXPHOS and FAO, are associated with glaucoma. These findings contribute to a better understanding of the molecular mechanisms underlying glaucoma pathogenesis and may offer potential targets for therapeutic interventions in the future.
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Affiliation(s)
- Zulvikar Syambani Ulhaq
- Research Center for Pre-clinical and Clinical Medicine, National Research and Innovation Agency Republic of Indonesia, Cibinong, Indonesia; Laboratory of Developmental Disorders and Toxicology, Center for Promotion of International Education and Research, Faculty of Agriculture, Kyushu University, Fukuoka, Japan.
| | - Guido Barbieri Bittencourt
- Departamento de Psicologia Experimental, Instituto de Psicologia, Universidade de São Paulo, São Paulo, Brazil
| | - Gita Vita Soraya
- Department of Biochemistry, Faculty of Medicine, Hasanuddin University, Makassar, Indonesia
| | - Lola Ayu Istifiani
- Department of Nutrition, Faculty of Health Sciences, Brawijaya University, Malang, Indonesia
| | | | - Yukiko Ogino
- Laboratory of Aquatic Molecular Developmental Biology, Center for Promotion of International Education and Research, Faculty of Agriculture, Kyushu University, Fukuoka, Japan
| | | | - William Ka Fai Tse
- Laboratory of Developmental Disorders and Toxicology, Center for Promotion of International Education and Research, Faculty of Agriculture, Kyushu University, Fukuoka, Japan.
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2
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Ju WK, Perkins GA, Kim KY, Bastola T, Choi WY, Choi SH. Glaucomatous optic neuropathy: Mitochondrial dynamics, dysfunction and protection in retinal ganglion cells. Prog Retin Eye Res 2023; 95:101136. [PMID: 36400670 DOI: 10.1016/j.preteyeres.2022.101136] [Citation(s) in RCA: 23] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Revised: 10/04/2022] [Accepted: 11/03/2022] [Indexed: 11/18/2022]
Abstract
Glaucoma is a leading cause of irreversible blindness worldwide and is characterized by a slow, progressive, and multifactorial degeneration of retinal ganglion cells (RGCs) and their axons, resulting in vision loss. Despite its high prevalence in individuals 60 years of age and older, the causing factors contributing to glaucoma progression are currently not well characterized. Intraocular pressure (IOP) is the only proven treatable risk factor. However, lowering IOP is insufficient for preventing disease progression. One of the significant interests in glaucoma pathogenesis is understanding the structural and functional impairment of mitochondria in RGCs and their axons and synapses. Glaucomatous risk factors such as IOP elevation, aging, genetic variation, neuroinflammation, neurotrophic factor deprivation, and vascular dysregulation, are potential inducers for mitochondrial dysfunction in glaucoma. Because oxidative phosphorylation stress-mediated mitochondrial dysfunction is associated with structural and functional impairment of mitochondria in glaucomatous RGCs, understanding the underlying mechanisms and relationship between structural and functional alterations in mitochondria would be beneficial to developing mitochondria-related neuroprotection in RGCs and their axons and synapses against glaucomatous neurodegeneration. Here, we review the current studies focusing on mitochondrial dynamics-based structural and functional alterations in the mitochondria of glaucomatous RGCs and therapeutic strategies to protect RGCs against glaucomatous neurodegeneration.
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Affiliation(s)
- Won-Kyu Ju
- Hamilton Glaucoma Center and Viterbi Family Department of Ophthalmology and Shiley Eye Institute, University of California San Diego, La Jolla, CA, 92093, USA.
| | - Guy A Perkins
- National Center for Microscopy and Imaging Research, Department of Neurosciences, University of California San Diego, La Jolla, CA, 92093, USA
| | - Keun-Young Kim
- National Center for Microscopy and Imaging Research, Department of Neurosciences, University of California San Diego, La Jolla, CA, 92093, USA
| | - Tonking Bastola
- Hamilton Glaucoma Center and Viterbi Family Department of Ophthalmology and Shiley Eye Institute, University of California San Diego, La Jolla, CA, 92093, USA
| | - Woo-Young Choi
- Hamilton Glaucoma Center and Viterbi Family Department of Ophthalmology and Shiley Eye Institute, University of California San Diego, La Jolla, CA, 92093, USA; Department of Plastic Surgery, College of Medicine, Chosun University, Gwang-ju, South Korea
| | - Soo-Ho Choi
- Department of Medicine, University of California San Diego, La Jolla, CA, 92093, USA
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3
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Sharma R, Sharma A. Population stratification strategies in artificial intelligence-based glaucoma monitoring, "corneal anthropology" to bridge gap between genetics and clinics? Indian J Ophthalmol 2023; 71:2304-2306. [PMID: 37202987 PMCID: PMC10391406 DOI: 10.4103/ijo.ijo_3061_22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/20/2023] Open
Affiliation(s)
- Rajan Sharma
- Research Associate, Dr. Ashok Sharma's Cornea Centre, Chandigarh, India
| | - Ashok Sharma
- Senior Cornea Consultant and Medical Director, Dr. Ashok Sharma's Cornea Centre, Chandigarh, India
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4
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Arévalo-López C, Gleitze S, Madariaga S, Plaza-Rosales I. Pupillary response to chromatic light stimuli as a possible biomarker at the early stage of glaucoma: a review. Int Ophthalmol 2023; 43:343-356. [PMID: 35781599 DOI: 10.1007/s10792-022-02381-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Accepted: 06/14/2022] [Indexed: 02/07/2023]
Abstract
Glaucoma is a multifactorial neurodegenerative disease of the optic nerve currently considered a severe health problem because of its high prevalence, being the primary cause of irreversible blindness worldwide. The most common type corresponds to Primary Open-Angle Glaucoma. Glaucoma produces, among other alterations, a progressive loss of retinal ganglion cells (RGC) and its axons which are the key contributors to generate action potentials that reach the visual cortex to create the visual image. Glaucoma is characterized by Visual Field loss whose main feature is to be painless and therefore makes early detection difficult, causing a late diagnosis and a delayed treatment indication that slows down its progression. Intrinsically photosensitive retinal ganglion cells, which represent a subgroup of RGCs are characterized by their response to short-wave light stimulation close to 480 nm, their non-visual function, and their role in the generation of the pupillary reflex. Currently, the sensitivity of clinical examinations correlates to RGC damage; however, the need for an early damage biomarker is still relevant. It is an urgent task to create new diagnostic approaches to detect an early stage of glaucoma in a prompt, quick, and economical manner. We summarize the pathology of glaucoma and its current clinical detection methods, and we suggest evaluating the pupillary response to chromatic light as a potential biomarker of disease, due to its diagnostic benefit and its cost-effectiveness in clinical practice in order to reduce irreversible damage caused by glaucoma.
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Affiliation(s)
- Carla Arévalo-López
- Department of Medical Technology, Faculty of Medicine, Universidad de Chile, Santiago, Chile
| | - Silvia Gleitze
- Biomedical Neuroscience Institute, Faculty of Medicine, Universidad de Chile, Santiago, Chile
| | - Samuel Madariaga
- Biomedical Neuroscience Institute, Faculty of Medicine, Universidad de Chile, Santiago, Chile.,Laboratorio de Neurosistemas, Department of Neuroscience, Faculty of Medicine, Universidad de Chile, Santiago, Chile.,Ecological Cognitive Neuroscience Group, Santiago, Chile
| | - Iván Plaza-Rosales
- Department of Medical Technology, Faculty of Medicine, Universidad de Chile, Santiago, Chile. .,Biomedical Neuroscience Institute, Faculty of Medicine, Universidad de Chile, Santiago, Chile. .,Laboratorio de Neurosistemas, Department of Neuroscience, Faculty of Medicine, Universidad de Chile, Santiago, Chile. .,Ecological Cognitive Neuroscience Group, Santiago, Chile.
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5
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Anand S, Trounce IA, Gangoda L. Role of extracellular vesicles in mitochondrial eye diseases. IUBMB Life 2022; 74:1264-1272. [PMID: 36308309 PMCID: PMC10947567 DOI: 10.1002/iub.2687] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Accepted: 10/14/2022] [Indexed: 03/20/2024]
Abstract
Extracellular vesicles (EVs) are small packages that are released by almost all types of cells. While the role of EVs in pathogenesis of certain diseases such as cancer is well established, EVs role in ocular health and disease is still at early stages of investigation. Given the significant role of EVs in pathological development and progression of diseases such as cancer, EVs present a similar opportunity for investigation in ocular pathophysiology. Studies have shown the presence of EVs in fluids from the ocular environment have close links with ocular health and disease. Hence, the cargo carried in EVs from ocular fluids can be used for monitoring disease phenotypes or therapeutic outcomes in eye-related disorders. Furthermore, in recent times EVs have increasingly gained attention as therapeutics and drug-delivery vehicles for treatment of eye diseases. There is a close relationship between EVs and mitochondria functioning with mitochondria dysfunction leading to a significant number of ophthalmic disorders. This review discusses the current knowledge of EVs in visual systems with a special focus on eye diseases resulting from dysfunctional mitochondria.
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Affiliation(s)
- Sushma Anand
- Centre for Eye Research AustraliaRoyal Victorian Eye and Ear HospitalEast MelbourneVictoriaAustralia
- Opthalmology, Department of SurgeryUniversity of MelbourneMelbourneVictoriaAustralia
| | - Ian A. Trounce
- Centre for Eye Research AustraliaRoyal Victorian Eye and Ear HospitalEast MelbourneVictoriaAustralia
- Opthalmology, Department of SurgeryUniversity of MelbourneMelbourneVictoriaAustralia
| | - Lahiru Gangoda
- Centre for Eye Research AustraliaRoyal Victorian Eye and Ear HospitalEast MelbourneVictoriaAustralia
- Opthalmology, Department of SurgeryUniversity of MelbourneMelbourneVictoriaAustralia
- The Walter and Eliza Hall Institute of Medical Research (WEHI)MelbourneVictoriaAustralia
- Department of Medical BiologyUniversity of MelbourneMelbourneVictoriaAustralia
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6
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Chakraborty M, Rao A. Alternate Causes for Pathogenesis of Exfoliation Glaucoma, a Multifactorial Elastotic Disorder: A Literature Review. Curr Issues Mol Biol 2022; 44:1191-1202. [PMID: 35723301 PMCID: PMC8946964 DOI: 10.3390/cimb44030078] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2022] [Revised: 02/17/2022] [Accepted: 02/19/2022] [Indexed: 12/27/2022] Open
Abstract
Exfoliation glaucoma (XFG) is the most recognizable form of secondary open-angle glaucoma associated with a high risk of blindness. This disease is characterized by white flaky granular deposits in the anterior chamber that leads to the elevation of intraocular pressure (IOP) and subsequent glaucomatous optic nerve damage. Conventionally, XFG is known to respond poorly to medical therapy, and surgical intervention is the only management option in most cases. Various genetic and nongenetic factors are known to be linked to the development of XFG. Despite decades of research on the genetic factors in exfoliation syndrome (XFS) by study groups and global consortia involving different ethnic populations, the pathogenesis of XFS and the mechanism of onset of glaucoma still remains an unsolved mystery. The key lies in understanding how the function of a gene (or set of genes) is altered by environmental triggers, along with other molecular events that underlie the key disease attributes, namely, oxidative stress and the disruption of the blood–aqueous barrier (BAB). It remains a challenge to evolve a theory encompassing all factions of molecular events occurring independently or parallelly that determine the disease manifestation (phenotype) or the stage of the disease in the eye (or in any tissue) in exfoliation. Our enhanced understanding of the underlying molecular pathophysiology of XFG, beyond the known genes or polymorphisms involved in the disease, will lead to improved diagnosis and management and the ability to recognize how the environment influences these key events that lead to the disease phenotype or disease progression. This review summarizes the recent observations and discoveries of four key factors that may hold the answers to the non-lysyl oxidase-like 1 (LOXL1) mechanisms behind XFG pathogenesis, namely, the epigenetic factor miRNA, disordered autophagy along with the potential involvement of mitochondrial mutations, and a compromised aqueous–blood barrier.
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Affiliation(s)
- Munmun Chakraborty
- Hyderabad Eye Research Foundation (HERF), L.V. Prasad Eye Institute, Bhubaneswar 751024, Odisha, India;
- School of Biotechnology, KIIT University, Bhubaneswar 751024, Odisha, India
| | - Aparna Rao
- Hyderabad Eye Research Foundation (HERF), L.V. Prasad Eye Institute, Bhubaneswar 751024, Odisha, India;
- School of Biotechnology, KIIT University, Bhubaneswar 751024, Odisha, India
- Correspondence:
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Lo Faro V, Nolte IM, Ten Brink JB, Snieder H, Jansonius NM, Bergen AA. Mitochondrial Genome Study Identifies Association Between Primary Open-Angle Glaucoma and Variants in MT-CYB, MT-ND4 Genes and Haplogroups. Front Genet 2021; 12:781189. [PMID: 34976016 PMCID: PMC8719162 DOI: 10.3389/fgene.2021.781189] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Accepted: 11/29/2021] [Indexed: 11/21/2022] Open
Abstract
Background and purpose: Primary open-angle glaucoma (POAG) is an optic neuropathy characterized by death of retinal ganglion cells and atrophy of the optic nerve head. The susceptibility of the optic nerve to damage has been shown to be mediated by mitochondrial dysfunction. In this study, we aimed to determine a possible association between mitochondrial SNPs or haplogroups and POAG. Methods: Mitochondrial DNA single nucleotide polymorphisms (mtSNPs) were genotyped using the Illumina Infinium Global Screening Array-24 (GSA) 700K array set. Genetic analyses were performed in a POAG case-control study involving the cohorts, Groningen Longitudinal Glaucoma Study-Lifelines Cohort Study and Amsterdam Glaucoma Study, including 721 patients and 1951 controls in total. We excluded samples not passing quality control for nuclear genotypes and samples with low call rate for mitochondrial variation. The mitochondrial variants were analyzed both as SNPs and haplogroups. These were determined with the bioinformatics software HaploGrep, and logistic regression analysis was used for the association, as well as for SNPs. Results: Meta-analysis of the results from both cohorts revealed a significant association between POAG and the allele A of rs2853496 [odds ratio (OR) = 0.64; p = 0.006] within the MT-ND4 gene, and for the T allele of rs35788393 (OR = 0.75; p = 0.041) located in the MT-CYB gene. In the mitochondrial haplogroup analysis, the most significant p-value was reached by haplogroup K (p = 1.2 × 10−05), which increases the risk of POAG with an OR of 5.8 (95% CI 2.7–13.1). Conclusion: We identified an association between POAG and polymorphisms in the mitochondrial genes MT-ND4 (rs2853496) and MT-CYB (rs35788393), and with haplogroup K. The present study provides further evidence that mitochondrial genome variations are implicated in POAG. Further genetic and functional studies are required to substantiate the association between mitochondrial gene polymorphisms and POAG and to define the pathophysiological mechanisms of mitochondrial dysfunction in glaucoma.
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Affiliation(s)
- Valeria Lo Faro
- Department of Ophthalmology, University of Groningen, University Medical Center Groningen, Groningen, Netherlands
- Department of Clinical Genetics, Amsterdam University Medical Center (AMC), Amsterdam, Netherlands
| | - Ilja M. Nolte
- Department of Epidemiology, University of Groningen, University Medical Center Groningen, Groningen, Netherlands
| | - Jacoline B. Ten Brink
- Department of Clinical Genetics, Amsterdam University Medical Center (AMC), Amsterdam, Netherlands
| | - Harold Snieder
- Department of Epidemiology, University of Groningen, University Medical Center Groningen, Groningen, Netherlands
| | - Nomdo M. Jansonius
- Department of Ophthalmology, University of Groningen, University Medical Center Groningen, Groningen, Netherlands
| | - Arthur A. Bergen
- Department of Clinical Genetics, Amsterdam University Medical Center (AMC), Amsterdam, Netherlands
- Department of Ophthalmology, Amsterdam UMC, Amsterdam, Netherlands
- *Correspondence: Arthur A. Bergen,
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8
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Singh LN, Kao SH, Wallace DC. Unlocking the Complexity of Mitochondrial DNA: A Key to Understanding Neurodegenerative Disease Caused by Injury. Cells 2021; 10:cells10123460. [PMID: 34943968 PMCID: PMC8715673 DOI: 10.3390/cells10123460] [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: 09/30/2021] [Revised: 12/03/2021] [Accepted: 12/06/2021] [Indexed: 12/12/2022] Open
Abstract
Neurodegenerative disorders that are triggered by injury typically have variable and unpredictable outcomes due to the complex and multifactorial cascade of events following the injury and during recovery. Hence, several factors beyond the initial injury likely contribute to the disease progression and pathology, and among these are genetic factors. Genetics is a recognized factor in determining the outcome of common neurodegenerative diseases. The role of mitochondrial genetics and function in traditional neurodegenerative diseases, such as Alzheimer’s and Parkinson’s diseases, is well-established. Much less is known about mitochondrial genetics, however, regarding neurodegenerative diseases that result from injuries such as traumatic brain injury and ischaemic stroke. We discuss the potential role of mitochondrial DNA genetics in the progression and outcome of injury-related neurodegenerative diseases. We present a guide for understanding mitochondrial genetic variation, along with the nuances of quantifying mitochondrial DNA variation. Evidence supporting a role for mitochondrial DNA as a risk factor for neurodegenerative disease is also reviewed and examined. Further research into the impact of mitochondrial DNA on neurodegenerative disease resulting from injury will likely offer key insights into the genetic factors that determine the outcome of these diseases together with potential targets for treatment.
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Affiliation(s)
- Larry N. Singh
- Center for Mitochondrial and Epigenomic Medicine, Division of Human Genetics, The Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA;
- Correspondence:
| | - Shih-Han Kao
- Resuscitation Science Center, The Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA;
| | - Douglas C. Wallace
- Center for Mitochondrial and Epigenomic Medicine, Division of Human Genetics, The Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA;
- Department of Pediatrics, Division of Human Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
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9
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Singh LN, Ennis B, Loneragan B, Tsao NL, Lopez Sanchez MIG, Li J, Acheampong P, Tran O, Trounce IA, Zhu Y, Potluri P, Emanuel BS, Rader DJ, Arany Z, Damrauer SM, Resnick AC, Anderson SA, Wallace DC. MitoScape: A big-data, machine-learning platform for obtaining mitochondrial DNA from next-generation sequencing data. PLoS Comput Biol 2021; 17:e1009594. [PMID: 34762648 PMCID: PMC8610268 DOI: 10.1371/journal.pcbi.1009594] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Revised: 11/23/2021] [Accepted: 10/27/2021] [Indexed: 11/18/2022] Open
Abstract
The growing number of next-generation sequencing (NGS) data presents a unique opportunity to study the combined impact of mitochondrial and nuclear-encoded genetic variation in complex disease. Mitochondrial DNA variants and in particular, heteroplasmic variants, are critical for determining human disease severity. While there are approaches for obtaining mitochondrial DNA variants from NGS data, these software do not account for the unique characteristics of mitochondrial genetics and can be inaccurate even for homoplasmic variants. We introduce MitoScape, a novel, big-data, software for extracting mitochondrial DNA sequences from NGS. MitoScape adopts a novel departure from other algorithms by using machine learning to model the unique characteristics of mitochondrial genetics. We also employ a novel approach of using rho-zero (mitochondrial DNA-depleted) data to model nuclear-encoded mitochondrial sequences. We showed that MitoScape produces accurate heteroplasmy estimates using gold-standard mitochondrial DNA data. We provide a comprehensive comparison of the most common tools for obtaining mtDNA variants from NGS and showed that MitoScape had superior performance to compared tools in every statistically category we compared, including false positives and false negatives. By applying MitoScape to common disease examples, we illustrate how MitoScape facilitates important heteroplasmy-disease association discoveries by expanding upon a reported association between hypertrophic cardiomyopathy and mitochondrial haplogroup T in men (adjusted p-value = 0.003). The improved accuracy of mitochondrial DNA variants produced by MitoScape will be instrumental in diagnosing disease in the context of personalized medicine and clinical diagnostics. Recent studies have highlighted the importance of mitochondrial DNA variation in both primary mitochondrial disease and complex, human pathology including COVID-19, and space-flight stress. The vast amount of existing, next-generation sequencing (NGS) data can be leveraged to interrogate both nuclear and mitochondrial DNA (mtDNA) sequence simultaneously, allowing for analysis of the interplay between mitochondrial and nuclear encoded genes in mitochondrial function. Identifying mtDNA sequence accurately is complicated by the presence of nuclear encoded mitochondrial sequences (NUMTs), which are homologous to mtDNA. Current software for analyzing mtDNA from NGS do not accurately model the unique characteristics of mitochondrial genetics. We introduce MitoScape, a novel, big-data, software which models mitochondrial genetics through machine learning to accurately identify mtDNA sequence from NGS data. MitoScape takes advantage of rho-zero cell data to model the characteristics of NUMTs. We show that MitoScape produces more accurate heteroplasmy estimates compared to published software. We provide an example of applying MitoScape in replicating an association between hypertrophic cardiomyopathy and mitochondrial haplogroup T in men. MitoScape is an important contribution to mitochondrial genomics allowing for accurate mtDNA variants, and the ability to tailor mtDNA analysis in different population and disease contexts, which is not available in other software.
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Affiliation(s)
- Larry N. Singh
- Center for Mitochondrial and Epigenomic Medicine, Division of Human Genetics, The Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, United States of America
- * E-mail:
| | - Brian Ennis
- Center for Data-Driven Discovery in Biomedicine (D3b), The Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, United States of America
| | - Bryn Loneragan
- Center for Eye Research Australia, Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, Australia
| | - Noah L. Tsao
- Department of Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - M. Isabel G. Lopez Sanchez
- Center for Eye Research Australia, Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, Australia
| | - Jianping Li
- Department of Psychiatry, The Children’s Hospital of Philadelphia and the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Patrick Acheampong
- Center for Mitochondrial and Epigenomic Medicine, Division of Human Genetics, The Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, United States of America
| | - Oanh Tran
- 22q and You Center, Division of Human Genetics, The Children’s Hospital of Philadelphia and the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Ian A. Trounce
- Center for Eye Research Australia, Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, Australia
| | - Yuankun Zhu
- Center for Data-Driven Discovery in Biomedicine (D3b), The Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, United States of America
| | - Prasanth Potluri
- Center for Mitochondrial and Epigenomic Medicine, Division of Human Genetics, The Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, United States of America
| | | | - Beverly S. Emanuel
- 22q and You Center, Division of Human Genetics, The Children’s Hospital of Philadelphia and the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Daniel J. Rader
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Zoltan Arany
- Cardiovascular Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Scott M. Damrauer
- Department of Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Adam C. Resnick
- Center for Data-Driven Discovery in Biomedicine (D3b), The Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, United States of America
| | - Stewart A. Anderson
- Department of Psychiatry, The Children’s Hospital of Philadelphia and the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Douglas C. Wallace
- Center for Mitochondrial and Epigenomic Medicine, Division of Human Genetics, The Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, United States of America
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10
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Carrella S, Massa F, Indrieri A. The Role of MicroRNAs in Mitochondria-Mediated Eye Diseases. Front Cell Dev Biol 2021; 9:653522. [PMID: 34222230 PMCID: PMC8249810 DOI: 10.3389/fcell.2021.653522] [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] [Received: 01/14/2021] [Accepted: 05/20/2021] [Indexed: 12/15/2022] Open
Abstract
The retina is among the most metabolically active tissues with high-energy demands. The peculiar distribution of mitochondria in cells of retinal layers is necessary to assure the appropriate energy supply for the transmission of the light signal. Photoreceptor cells (PRs), retinal pigment epithelium (RPE), and retinal ganglion cells (RGCs) present a great concentration of mitochondria, which makes them particularly sensitive to mitochondrial dysfunction. To date, visual loss has been extensively correlated to defective mitochondrial functions. Many mitochondrial diseases (MDs) show indeed neuro-ophthalmic manifestations, including retinal and optic nerve phenotypes. Moreover, abnormal mitochondrial functions are frequently found in the most common retinal pathologies, i.e., glaucoma, age-related macular degeneration (AMD), and diabetic retinopathy (DR), that share clinical similarities with the hereditary primary MDs. MicroRNAs (miRNAs) are established as key regulators of several developmental, physiological, and pathological processes. Dysregulated miRNA expression profiles in retinal degeneration models and in patients underline the potentiality of miRNA modulation as a possible gene/mutation-independent strategy in retinal diseases and highlight their promising role as disease predictive or prognostic biomarkers. In this review, we will summarize the current knowledge about the participation of miRNAs in both rare and common mitochondria-mediated eye diseases. Definitely, given the involvement of miRNAs in retina pathologies and therapy as well as their use as molecular biomarkers, they represent a determining target for clinical applications.
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Affiliation(s)
| | - Filomena Massa
- Telethon Institute of Genetics and Medicine, Naples, Italy
| | - Alessia Indrieri
- Telethon Institute of Genetics and Medicine, Naples, Italy.,Institute for Genetic and Biomedical Research, National Research Council (CNR), Milan, Italy
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11
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Mitochondrial DNA A3243G variant-associated retinopathy: Current perspectives and clinical implications. Surv Ophthalmol 2021; 66:838-855. [PMID: 33610586 DOI: 10.1016/j.survophthal.2021.02.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2020] [Revised: 02/08/2021] [Accepted: 02/09/2021] [Indexed: 12/12/2022]
Abstract
Cellular function and survival are critically dependent on the proper functionality of the mitochondrion. Neurodegenerative cellular processes including cellular adenosine triphosphate production, intermediary metabolism control, and apoptosis regulation are all mitochondrially mediated. The A to G transition at position 3243 in the mitochondrial MTTL1 gene that encodes for the leucine transfer RNA (m.3243A>G) causes a variety of diseases, including maternally inherited loss of hearing and diabetes syndrome (MIDD), mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes syndrome (MELAS). Ophthalmological findings-including posterior sub-capsular cataract, ptosis, external ophthalmoplegia, and pigmentary retinopathy- have all been associated with the m.3243A>G variant. Pigmentary retinopathy is, however, the most common ocular finding, occurring in 38% to 86% of cases. To date, little is known about the pathogenesis, natural history, and heteroplasmic and phenotypic correlations of m.3243A>G-associated pigmentary retinopathy. We summarize the current understanding of mitochondrial genetics and pathogenesis of some associated diseases. We then review the pathophysiology, histology, clinical features, treatment, and important ocular and systemic phenotypic manifestations of m.3243A>G variant associated retinopathy. Mitochondrial diseases require a multidisciplinary team approach to ensure effective treatment, regular follow-up, and accurate genetic counseling.
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Atilano SR, Udar N, Satalich TA, Udar V, Chwa M, Kenney MC. Low frequency mitochondrial DNA heteroplasmy SNPs in blood, retina, and [RPE+choroid] of age-related macular degeneration subjects. PLoS One 2021; 16:e0246114. [PMID: 33513185 PMCID: PMC7846006 DOI: 10.1371/journal.pone.0246114] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2020] [Accepted: 01/13/2021] [Indexed: 01/07/2023] Open
Abstract
Purpose Mitochondrial (mt) DNA damage is associated with age-related macular degeneration (AMD) and other human aging diseases. This study was designed to quantify and characterize mtDNA low-frequency heteroplasmy single nucleotide polymorphisms (SNPs) of three different tissues isolated from AMD subjects using Next Generation Sequencing (NGS) technology. Methods DNA was extracted from neural retina, [RPE+choroid] and blood from three deceased age-related macular degeneration (AMD) subjects. Entire mitochondrial genomes were analyzed for low-frequency heteroplasmy SNPs using NGS technology that independently sequenced both mtDNA strands. This deep sequencing method (average sequencing depth of 30,000; range 1,000–100,000) can accurately differentiate low-frequency heteroplasmy SNPs from DNA modification artifacts. Twenty-three ‘hot-spot’ heteroplasmy mtDNA SNPs were analyzed in 222 additional blood samples. Results Germline homoplasmy SNPs that defined mtDNA haplogroups were consistent in the three tissues of each subject. Analyses of SNPs with <40% heteroplasmy revealed the blood had significantly greater numbers of heteroplasmy SNPs than retina alone (p≤0.05) or retina+choroid combined (p = 0.008). Twenty-three ‘hot-spot’ mtDNA heteroplasmy SNPs were present, with three being non-synonymous (amino acid change). Four ‘hot-spot’ heteroplasmy SNPs (m.1120C>T, m.1284T>C, m.1556C>T, m.7256C>T) were found in additional samples (n = 222). Five heteroplasmy SNPs (m.4104A>G, m.5320C>T, m.5471G>A, m.5474A>G, m.5498A>G) declined with age. Two heteroplasmy SNPs (m.13095T>C, m.13105A>G) increased in AMD compared to Normal samples. In the heteroplasmy SNPs, very few transversion mutations (purine to pyrimidine or vice versa, associated with oxidative damage) were found and the majority were transition changes (purine to purine or pyrimidine to pyrimidine, associated with replication errors). Conclusion Within an individual, the blood, retina and [RPE+choroid] contained identical homoplasmy SNPs representing inherited germline mtDNA haplogroup. NGS methodology showed significantly more mtDNA heteroplasmy SNPs in blood compared to retina and [RPE+choroid], suggesting the latter tissues have substantial protection. Significantly higher heteroplasmy levels of m.13095T>C and m.13105A>G may represent potential AMD biomarkers. Finally, high levels of transition mutations suggest that accumulation of heteroplasmic SNPs may occur through replication errors rather than oxidative damage.
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Affiliation(s)
- Shari R. Atilano
- Gavin Herbert Eye Institute, University of California Irvine, Irvine, CA, United States of America
| | - Nitin Udar
- Gavin Herbert Eye Institute, University of California Irvine, Irvine, CA, United States of America
| | - Timothy A. Satalich
- Institute for Mathematical Behavioral Science, University of California Irvine, Irvine, CA, United States of America
| | - Viraat Udar
- Gavin Herbert Eye Institute, University of California Irvine, Irvine, CA, United States of America
| | - Marilyn Chwa
- Gavin Herbert Eye Institute, University of California Irvine, Irvine, CA, United States of America
| | - M. Cristina Kenney
- Gavin Herbert Eye Institute, University of California Irvine, Irvine, CA, United States of America
- Department of Pathology and Laboratory Medicine, University of California Irvine, Irvine, CA, United States of America
- * E-mail:
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Piotrowska-Nowak A, Krawczyński MR, Kosior-Jarecka E, Ambroziak AM, Korwin M, Ołdak M, Tońska K, Bartnik E. Mitochondrial genome variation in male LHON patients with the m.11778G > A mutation. Metab Brain Dis 2020; 35:1317-1327. [PMID: 32740724 PMCID: PMC7584531 DOI: 10.1007/s11011-020-00605-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Accepted: 07/21/2020] [Indexed: 11/30/2022]
Abstract
Leber hereditary optic neuropathy (LHON) is a mitochondrial disorder with symptoms limited to a single tissue, optic nerve, resulting in vision loss. In the majority of cases it is caused by one of three point mutations in mitochondrial DNA (mtDNA) but their presence is not sufficient for disease development, since ~50% of men and ~10% women who carry them are affected. Thus additional modifying factors must exist. In this study, we use next generation sequencing to investigate the role of whole mtDNA variation in male Polish patients with LHON and m.11778G > A, the most frequent LHON mutation. We present a possible association between mtDNA haplogroup K and variants in its background, a combination of m.3480A > G, m.9055G > A, m.11299 T > C and m.14167C > T, and LHON mutation. These variants may have a negative effect on m.11778G > A increasing its penetrance and the risk of LHON in the Polish population. Surprisingly, we did not observe associations previously reported for m.11778G > A and LHON in European populations, particularly for haplogroup J as a risk factor, implying that mtDNA variation is much more complex. Our results indicate possible contribution of novel combination of mtDNA genetic factors to the LHON phenotype.
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Affiliation(s)
- Agnieszka Piotrowska-Nowak
- Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, 5a Pawińskiego Street, 02-106 Warsaw, Poland
| | - Maciej R. Krawczyński
- Department of Medical Genetics, Poznań University of Medical Sciences, 8 Rokietnicka Street, 60-806 Poznań, Poland
- Centers for Medical Genetics GENESIS, 4 Grudzieniec Street, 60-601 Poznań, Poland
| | - Ewa Kosior-Jarecka
- Department of Diagnostics and Microsurgery of Glaucoma, Medical University of Lublin, 1 Chmielna Street, 20-079 Lublin, Poland
| | - Anna M. Ambroziak
- Faculty of Physics, University of Warsaw, 5 Pasteur Street, 02-093 Warsaw, Poland
| | - Magdalena Korwin
- Department of Ophthalmology, Medical University of Warsaw, 13 Sierakowskiego Street, 03-709 Warsaw, Poland
| | - Monika Ołdak
- Department of Genetics, Institute of Physiology and Pathology of Hearing, 10 Mochnackiego Street, 02-042 Warsaw, Poland
- Department of Histology and Embryology, Center of Biostructure Research, Medical University of Warsaw, 5 Chałubińskiego Street, 02-004 Warsaw, Poland
| | - Katarzyna Tońska
- Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, 5a Pawińskiego Street, 02-106 Warsaw, Poland
| | - Ewa Bartnik
- Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, 5a Pawińskiego Street, 02-106 Warsaw, Poland
- Institute of Biochemistry and Biophysics Polish Academy of Sciences, 5a Pawińskiego Street, 02-106 Warsaw, Poland
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Pang Y, Qin M, Hu P, Ji K, Xiao R, Sun N, Pan X, Zhang X. Resveratrol protects retinal ganglion cells against ischemia induced damage by increasing Opa1 expression. Int J Mol Med 2020; 46:1707-1720. [PMID: 32901846 PMCID: PMC7521588 DOI: 10.3892/ijmm.2020.4711] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Accepted: 07/27/2020] [Indexed: 12/15/2022] Open
Abstract
Loss of idiopathic retinal ganglion cells (RGCs) leads to irreversible vision defects and is considered the primary characteristic of glaucoma. However, effective treatment strategies in terms of RGC neuroprotection remain elusive. In the present study, the protective effects of resveratrol on RGC apoptosis, and the mechanisms underlying its effects were investigated, with a particular emphasis on the function of optic atrophy 1 (Opa1). In an ischemia/reperfusion (I/R) injury model, the notable thinning of the retina, significant apoptosis of RGCs, reduction in Opa1 expression and long Opa1 isoform to short Opa1 isoform ratios (L-Opa1/S-Opa1 ratio) were observed, all of which were reversed by resveratrol administration. Serum deprivation resulted in reductions in R28 cell viability, superoxide dismutase (SOD) activity, Opa1 expression and induced apoptosis, which were also partially reversed by resveratrol treatment. To conclude, results from the present study suggest that resveratrol treatment significantly reduced retinal damage and RGC apoptosis in I/R injury and serum deprivation models. In addition, resveratrol reversed the downregulated expression of Opa1 and reduced SOD activity. Mechanistically, resveratrol influenced mitochondrial dynamics by regulating the L-Opa1/S-Opa1 ratio. Therefore, these observations suggest that resveratrol may exhibit potential as a therapeutic agent for RGC damage in the future.
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Affiliation(s)
- Yulian Pang
- Affiliated Eye Hospital of Nanchang University, Jiangxi Research Institute of Ophthalmology and Visual Science, Jiangxi Provincial Key Laboratory for Ophthalmology, Nanchang, Jiangxi 330006, P.R. China
| | - Mengqi Qin
- Affiliated Eye Hospital of Nanchang University, Jiangxi Research Institute of Ophthalmology and Visual Science, Jiangxi Provincial Key Laboratory for Ophthalmology, Nanchang, Jiangxi 330006, P.R. China
| | - Piaopiao Hu
- Affiliated Eye Hospital of Nanchang University, Jiangxi Research Institute of Ophthalmology and Visual Science, Jiangxi Provincial Key Laboratory for Ophthalmology, Nanchang, Jiangxi 330006, P.R. China
| | - Kaibao Ji
- Affiliated Eye Hospital of Nanchang University, Jiangxi Research Institute of Ophthalmology and Visual Science, Jiangxi Provincial Key Laboratory for Ophthalmology, Nanchang, Jiangxi 330006, P.R. China
| | - Ruihan Xiao
- Affiliated Eye Hospital of Nanchang University, Jiangxi Research Institute of Ophthalmology and Visual Science, Jiangxi Provincial Key Laboratory for Ophthalmology, Nanchang, Jiangxi 330006, P.R. China
| | - Nan Sun
- Affiliated Eye Hospital of Nanchang University, Jiangxi Research Institute of Ophthalmology and Visual Science, Jiangxi Provincial Key Laboratory for Ophthalmology, Nanchang, Jiangxi 330006, P.R. China
| | - Xinghui Pan
- Affiliated Eye Hospital of Nanchang University, Jiangxi Research Institute of Ophthalmology and Visual Science, Jiangxi Provincial Key Laboratory for Ophthalmology, Nanchang, Jiangxi 330006, P.R. China
| | - Xu Zhang
- Affiliated Eye Hospital of Nanchang University, Jiangxi Research Institute of Ophthalmology and Visual Science, Jiangxi Provincial Key Laboratory for Ophthalmology, Nanchang, Jiangxi 330006, P.R. China
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15
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Retinal energy metabolism in health and glaucoma. Prog Retin Eye Res 2020; 81:100881. [PMID: 32712136 DOI: 10.1016/j.preteyeres.2020.100881] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Revised: 06/25/2020] [Accepted: 06/28/2020] [Indexed: 01/17/2023]
Abstract
Energy metabolism refers to the processes by which life transfers energy to do cellular work. The retina's relatively large energy demands make it vulnerable to energy insufficiency. In addition, evolutionary pressures to optimize human vision have been traded against retinal ganglion cell bioenergetic fragility. Details of the metabolic profiles of the different retinal cells remain poorly understood and are challenging to resolve. Detailed immunohistochemical mapping of the energy pathway enzymes and substrate transporters has provided some insights and highlighted interspecies differences. The different spatial metabolic patterns between the vascular and avascular retinas can account for some inconsistent data in the literature. There is a consilience of evidence that at least some individuals with glaucoma have impaired RGC energy metabolism, either due to impaired nutrient supply or intrinsic metabolic perturbations. Bioenergetic-based therapy for glaucoma has a compelling pathophysiological foundation and is supported by recent successes in animal models. Recent demonstrations of visual and electrophysiological neurorecovery in humans with glaucoma is highly encouraging and motivates longer duration trials investigating bioenergetic neuroprotection.
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Edwards G, Perkins GA, Kim KY, Kong Y, Lee Y, Choi SH, Liu Y, Skowronska-Krawczyk D, Weinreb RN, Zangwill L, Strack S, Ju WK. Loss of AKAP1 triggers Drp1 dephosphorylation-mediated mitochondrial fission and loss in retinal ganglion cells. Cell Death Dis 2020; 11:254. [PMID: 32312949 PMCID: PMC7170863 DOI: 10.1038/s41419-020-2456-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Revised: 04/06/2020] [Accepted: 04/07/2020] [Indexed: 12/14/2022]
Abstract
Impairment of mitochondrial structure and function is strongly linked to glaucoma pathogenesis. Despite the widely appreciated disease relevance of mitochondrial dysfunction and loss, the molecular mechanisms underlying mitochondrial fragmentation and metabolic stress in glaucoma are poorly understood. We demonstrate here that glaucomatous retinal ganglion cells (RGCs) show loss of A-kinase anchoring protein 1 (AKAP1), activation of calcineurin (CaN) and reduction of dynamin-related protein 1 (Drp1) phosphorylation at serine 637 (Ser637). These findings suggest that AKAP1-mediated phosphorylation of Drp1 at Ser637 has a critical role in RGC survival in glaucomatous neurodegeneration. Male mice lacking AKAP1 show increases in CaN and total Drp1 levels, as well as a decrease in Drp1 phosphorylation at Ser637 in the retina. Ultrastructural analysis of mitochondria shows that loss of AKAP1 triggers mitochondrial fragmentation and loss, as well as mitophagosome formation in RGCs. Loss of AKAP1 deregulates oxidative phosphorylation (OXPHOS) complexes (Cxs) by increasing CxII and decreasing CxIII-V, leading to metabolic and oxidative stress. Also, loss of AKAP1 decreases Akt phosphorylation at Serine 473 (Ser473) and threonine 308 (Thr308) and activates the Bim/Bax signaling pathway in the retina. These results suggest that loss of AKAP1 has a critical role in RGC dysfunction by decreasing Drp1 phosphorylation at Ser637, deregulating OXPHOS, decreasing Akt phosphorylation at Ser473 and Thr308, and activating the Bim/Bax pathway in glaucomatous neurodegeneration. Thus, we propose that overexpression of AKAP1 or modulation of Drp1 phosphorylation at Ser637 are potential therapeutic strategies for neuroprotective intervention in glaucoma and other mitochondria-related optic neuropathies.
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Affiliation(s)
- Genea Edwards
- Hamilton Glaucoma Center and Shiley Eye Center, The Viterbi Family Department of Ophthalmology, University of California San Diego, La Jolla, CA, USA
| | - Guy A Perkins
- National Center for Microscopy and Imaging Research and Department of Neurosciences, University of California San Diego, La Jolla, CA, USA
| | - Keun-Young Kim
- National Center for Microscopy and Imaging Research and Department of Neurosciences, University of California San Diego, La Jolla, CA, USA
| | - YeEun Kong
- Hamilton Glaucoma Center and Shiley Eye Center, The Viterbi Family Department of Ophthalmology, University of California San Diego, La Jolla, CA, USA
| | - Yonghoon Lee
- Hamilton Glaucoma Center and Shiley Eye Center, The Viterbi Family Department of Ophthalmology, University of California San Diego, La Jolla, CA, USA
| | - Soo-Ho Choi
- Department of Medicine, University of California San Diego, La Jolla, CA, USA
| | - Yujia Liu
- Department of Pharmacology and Iowa Neuroscience Institute, University of Iowa, Iowa City, IA, USA
| | - Dorota Skowronska-Krawczyk
- Hamilton Glaucoma Center and Shiley Eye Center, The Viterbi Family Department of Ophthalmology, University of California San Diego, La Jolla, CA, USA
| | - Robert N Weinreb
- Hamilton Glaucoma Center and Shiley Eye Center, The Viterbi Family Department of Ophthalmology, University of California San Diego, La Jolla, CA, USA
| | - Linda Zangwill
- Hamilton Glaucoma Center and Shiley Eye Center, The Viterbi Family Department of Ophthalmology, University of California San Diego, La Jolla, CA, USA
| | - Stefan Strack
- Department of Pharmacology and Iowa Neuroscience Institute, University of Iowa, Iowa City, IA, USA
| | - Won-Kyu Ju
- Hamilton Glaucoma Center and Shiley Eye Center, The Viterbi Family Department of Ophthalmology, University of California San Diego, La Jolla, CA, USA.
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The mito-QC Reporter for Quantitative Mitophagy Assessment in Primary Retinal Ganglion Cells and Experimental Glaucoma Models. Int J Mol Sci 2020; 21:ijms21051882. [PMID: 32164182 PMCID: PMC7084520 DOI: 10.3390/ijms21051882] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Revised: 03/05/2020] [Accepted: 03/06/2020] [Indexed: 12/15/2022] Open
Abstract
Mitochondrial damage plays a prominent role in glaucoma. The only way cells can degrade whole mitochondria is via autophagy, in a process called mitophagy. Thus, studying mitophagy in the context of glaucoma is essential to understand the disease. Up to date limited tools are available for analyzing mitophagy in vivo. We have taken advantage of the mito-QC reporter, a recently generated mouse model that allows an accurate mitophagy assessment to fill this gap. We used primary RGCs and retinal explants derived from mito-QC mice to quantify mitophagy activation in vitro and ex vivo. We also analyzed mitophagy in retinal ganglion cells (RGCs), in vivo, using different mitophagy inducers, as well as after optic nerve crush (ONC) in mice, a commonly used surgical procedure to model glaucoma. Using mito-QC reporter we quantified mitophagy induced by several known inducers in primary RGCs in vitro, ex vivo and in vivo. We also found that RGCs were rescued from some glaucoma relevant stress factors by incubation with the iron chelator deferiprone (DFP). Thus, the mito-QC reporter-based model is a valuable tool for accurately analyzing mitophagy in the context of glaucoma.
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