1
|
Chen M, Wang Y, Dalal R, Du J, Vollrath D. Alternative oxidase blunts pseudohypoxia and photoreceptor degeneration due to RPE mitochondrial dysfunction. Proc Natl Acad Sci U S A 2024; 121:e2402384121. [PMID: 38865272 PMCID: PMC11194566 DOI: 10.1073/pnas.2402384121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Accepted: 05/15/2024] [Indexed: 06/14/2024] Open
Abstract
Loss of mitochondrial electron transport complex (ETC) function in the retinal pigment epithelium (RPE) in vivo results in RPE dedifferentiation and progressive photoreceptor degeneration, and has been implicated in the pathogenesis of age-related macular degeneration. Xenogenic expression of alternative oxidases in mammalian cells and tissues mitigates phenotypes arising from some mitochondrial electron transport defects, but can exacerbate others. We expressed an alternative oxidase from Ciona intestinalis (AOX) in ETC-deficient murine RPE in vivo to assess the retinal consequences of stimulating coenzyme Q oxidation and respiration without ATP generation. RPE-restricted expression of AOX in this context is surprisingly beneficial. This focused intervention mitigates RPE mTORC1 activation, dedifferentiation, hypertrophy, stress marker expression, pseudohypoxia, and aerobic glycolysis. These RPE cell autonomous changes are accompanied by increased glucose delivery to photoreceptors with attendant improvements in photoreceptor structure and function. RPE-restricted AOX expression normalizes accumulated levels of succinate and 2-hydroxyglutarate in ETC-deficient RPE, and counteracts deficiencies in numerous neural retinal metabolites. These features can be attributed to the activation of mitochondrial inner membrane flavoproteins such as succinate dehydrogenase and proline dehydrogenase, and alleviation of inhibition of 2-oxyglutarate-dependent dioxygenases such as prolyl hydroxylases and epigenetic modifiers. Our work underscores the importance to outer retinal health of coenzyme Q oxidation in the RPE and identifies a metabolic network critical for photoreceptor survival in the context of RPE mitochondrial dysfunction.
Collapse
Affiliation(s)
- Ming Chen
- Department of Genetics, Stanford University School of Medicine, Palo Alto, CA94305
| | - Yekai Wang
- Department of Ophthalmology and Visual Sciences, West Virginia University, Morgantown, WV26506
- Department of Biochemistry and Molecular Medicine, West Virginia University, Morgantown, WV26506
| | - Roopa Dalal
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA94305
| | - Jianhai Du
- Department of Ophthalmology and Visual Sciences, West Virginia University, Morgantown, WV26506
- Department of Biochemistry and Molecular Medicine, West Virginia University, Morgantown, WV26506
| | - Douglas Vollrath
- Department of Genetics, Stanford University School of Medicine, Palo Alto, CA94305
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA94305
| |
Collapse
|
2
|
Zhao N, Hao XN, Huang JM, Song ZM, Tao Y. Crosstalk Between Microglia and Müller Glia in the Age-Related Macular Degeneration: Role and Therapeutic Value of Neuroinflammation. Aging Dis 2024; 15:1132-1154. [PMID: 37728589 PMCID: PMC11081163 DOI: 10.14336/ad.2023.0823-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Accepted: 08/23/2023] [Indexed: 09/21/2023] Open
Abstract
Age-related macular degeneration (AMD) is a progressive neurodegeneration disease that causes photoreceptor demise and vision impairments. In AMD pathogenesis, the primary death of retinal neurons always leads to the activation of resident microglia. The migration of activated microglia to the ongoing retinal lesion and their morphological transformation from branching to ameboid-like are recognized as hallmarks of AMD pathogenesis. Activated microglia send signals to Müller cells and promote them to react correspondingly to damaging stimulus. Müller cells are a type of neuroglia cells that maintain the normal function of retinal neurons, modulating innate inflammatory responses, and stabilize retinal structure. Activated Müller cells can accelerate the progression of AMD by damaging neurons and blood vessels. Therefore, the crosstalk between microglia and Müller cells plays a homeostatic role in maintaining the retinal environment, and this interaction is complicatedly modulated. In particular, the mechanism of mutual regulation between the two glia populations is complex under pathological conditions. This paper reviews recent findings on the crosstalk between microglia and Müller glia during AMD pathology process, with special emphasis on its therapeutic potentials.
Collapse
Affiliation(s)
- Na Zhao
- Henan Eye Institute, Henan Eye Hospital, People’s Hospital of Zhengzhou University, Zhengzhou, China.
- Department of Physiology and Neurobiology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou 450001, China.
| | - Xiao-Na Hao
- Henan Eye Institute, Henan Eye Hospital, People’s Hospital of Zhengzhou University, Zhengzhou, China.
- Department of Physiology and Neurobiology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou 450001, China.
| | - Jie-Min Huang
- Henan Eye Institute, Henan Eye Hospital, People’s Hospital of Zhengzhou University, Zhengzhou, China.
- Department of Physiology and Neurobiology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou 450001, China.
| | - Zong-Ming Song
- Henan Eye Institute, Henan Eye Hospital, People’s Hospital of Zhengzhou University, Zhengzhou, China.
- Department of Physiology and Neurobiology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou 450001, China.
| | - Ye Tao
- Henan Eye Institute, Henan Eye Hospital, People’s Hospital of Zhengzhou University, Zhengzhou, China.
- Department of Physiology and Neurobiology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou 450001, China.
| |
Collapse
|
3
|
Koller A, Lamina C, Brandl C, Zimmermann ME, Stark KJ, Weissensteiner H, Würzner R, Heid IM, Kronenberg F. Systemic Evidence for Mitochondrial Dysfunction in Age-Related Macular Degeneration as Revealed by mtDNA Copy Number Measurements in Peripheral Blood. Int J Mol Sci 2023; 24:16406. [PMID: 38003595 PMCID: PMC10671207 DOI: 10.3390/ijms242216406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Revised: 11/09/2023] [Accepted: 11/14/2023] [Indexed: 11/26/2023] Open
Abstract
Mitochondrial dysfunction is a common occurrence in the aging process and is observed in diseases such as age-related macular degeneration (AMD). Increased levels of reactive oxygen species lead to damaged mitochondrial DNA (mtDNA), resulting in dysfunctional mitochondria, and, consequently, mtDNA causes further harm in the retinal tissue. However, it is unclear whether the effects are locally restricted to the high-energy-demanding retinal pigment epithelium or are also systematically present. Therefore, we measured mtDNA copy number (mtDNA-CN) in peripheral blood using a qPCR approach with plasmid normalization in elderly participants with and without AMD from the AugUR study (n = 2262). We found significantly lower mtDNA-CN in the blood of participants with early (n = 453) and late (n = 170) AMD compared to AMD-free participants (n = 1630). In regression analyses, we found lower mtDNA-CN to be associated with late AMD when compared with AMD-free participants. Each reduction of mtDNA-CN by one standard deviation increased the risk for late AMD by 24%. This association was most pronounced in geographic atrophy (OR = 1.76, 95% CI 1.19-2.60, p = 0.004), which has limited treatment options. These findings provide new insights into the relationship between mtDNA-CN in blood and AMD, suggesting that it may serve as a more accessible biomarker than mtDNA-CN in the retina.
Collapse
Affiliation(s)
- Adriana Koller
- Institute of Genetic Epidemiology, Medical University of Innsbruck, 6020 Innsbruck, Austria; (A.K.); (C.L.); (H.W.)
| | - Claudia Lamina
- Institute of Genetic Epidemiology, Medical University of Innsbruck, 6020 Innsbruck, Austria; (A.K.); (C.L.); (H.W.)
| | - Caroline Brandl
- Department of Genetic Epidemiology, University of Regensburg, 93053 Regensburg, Germany; (C.B.); (M.E.Z.); (K.J.S.); (I.M.H.)
- Department of Ophthalmology, University Hospital Regensburg, 93053 Regensburg, Germany
| | - Martina E. Zimmermann
- Department of Genetic Epidemiology, University of Regensburg, 93053 Regensburg, Germany; (C.B.); (M.E.Z.); (K.J.S.); (I.M.H.)
| | - Klaus J. Stark
- Department of Genetic Epidemiology, University of Regensburg, 93053 Regensburg, Germany; (C.B.); (M.E.Z.); (K.J.S.); (I.M.H.)
| | - Hansi Weissensteiner
- Institute of Genetic Epidemiology, Medical University of Innsbruck, 6020 Innsbruck, Austria; (A.K.); (C.L.); (H.W.)
| | - Reinhard Würzner
- Institute of Hygiene and Medical Microbiology, Medical University of Innsbruck, 6020 Innsbruck, Austria;
| | - Iris M. Heid
- Department of Genetic Epidemiology, University of Regensburg, 93053 Regensburg, Germany; (C.B.); (M.E.Z.); (K.J.S.); (I.M.H.)
| | - Florian Kronenberg
- Institute of Genetic Epidemiology, Medical University of Innsbruck, 6020 Innsbruck, Austria; (A.K.); (C.L.); (H.W.)
| |
Collapse
|
4
|
Sun R, Zhu H, Wang Y, Wang J, Jiang C, Cao Q, Zhang Y, Zhang Y, Yuan S, Liu Q. Circular RNA expression and the competitive endogenous RNA network in pathological, age-related macular degeneration events: A cross-platform normalization study. J Biomed Res 2023; 37:367-381. [PMID: 37366063 PMCID: PMC10541779 DOI: 10.7555/jbr.37.20230010] [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: 01/16/2023] [Revised: 02/20/2023] [Accepted: 02/20/2023] [Indexed: 06/28/2023] Open
Abstract
Age-related macular degeneration (AMD) causes irreversible blindness in people aged over 50 worldwide. The dysfunction of the retinal pigment epithelium is the primary cause of atrophic AMD. In the current study, we used the ComBat and Training Distribution Matching method to integrate data obtained from the Gene Expression Omnibus database. We analyzed the integrated sequencing data by the Gene Set Enrichment Analysis. Peroxisome and tumor necrosis factor-α (TNF-α) signaling and nuclear factor kappa B (NF-κB) were among the top 10 pathways, and thus we selected them to construct AMD cell models to identify differentially expressed circular RNAs (circRNAs). We then constructed a competing endogenous RNA network, which is related to differentially expressed circRNAs. This network included seven circRNAs, 15 microRNAs, and 82 mRNAs. The Kyoto Encyclopedia of Genes and Genomes analysis of mRNAs in this network showed that the hypoxia-inducible factor-1 (HIF-1) signaling pathway was a common downstream event. The results of the current study may provide insights into the pathological processes of atrophic AMD.
Collapse
Affiliation(s)
- Ruxu Sun
- Department of Ophthalmology, the First Affiliated Hospital of Nanjing Medical University, Nanjing Medical University, Nanjing, Jiangsu 211166, China
| | - Hongjing Zhu
- Department of Ophthalmology, the First Affiliated Hospital of Nanjing Medical University, Nanjing Medical University, Nanjing, Jiangsu 211166, China
| | - Ying Wang
- Department of Ophthalmology, the First Affiliated Hospital of Nanjing Medical University, Nanjing Medical University, Nanjing, Jiangsu 211166, China
| | - Jianan Wang
- Department of Ophthalmology, the First Affiliated Hospital of Nanjing Medical University, Nanjing Medical University, Nanjing, Jiangsu 211166, China
| | - Chao Jiang
- Department of Ophthalmology, the First Affiliated Hospital of Nanjing Medical University, Nanjing Medical University, Nanjing, Jiangsu 211166, China
| | - Qiuchen Cao
- Department of Ophthalmology, the First Affiliated Hospital of Nanjing Medical University, Nanjing Medical University, Nanjing, Jiangsu 211166, China
| | - Yeran Zhang
- Department of Ophthalmology, the First Affiliated Hospital of Nanjing Medical University, Nanjing Medical University, Nanjing, Jiangsu 211166, China
| | - Yichen Zhang
- Department of Ophthalmology, the First Affiliated Hospital of Nanjing Medical University, Nanjing Medical University, Nanjing, Jiangsu 211166, China
| | - Songtao Yuan
- Department of Ophthalmology, the First Affiliated Hospital of Nanjing Medical University, Nanjing Medical University, Nanjing, Jiangsu 211166, China
| | - Qinghuai Liu
- Department of Ophthalmology, the First Affiliated Hospital of Nanjing Medical University, Nanjing Medical University, Nanjing, Jiangsu 211166, China
| |
Collapse
|
5
|
Schneider K, Chwa M, Atilano SR, Nashine S, Udar N, Boyer DS, Jazwinski SM, Miceli MV, Nesburn AB, Kuppermann BD, Kenney MC. Differential modulation of cancer-related genes by mitochondrial DNA haplogroups and the STING DNA sensing system. FASEB Bioadv 2022; 4:675-689. [PMID: 36238361 PMCID: PMC9536090 DOI: 10.1096/fba.2019-00044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Revised: 07/10/2022] [Accepted: 08/11/2022] [Indexed: 11/13/2022] Open
Abstract
Activation of the Simulator of Interferon Genes (STING) system by mitochondrial (mt) DNA can upregulate type 1 interferon genes and enhance immune responses to combat bacterial and viral infections. In cancers, the tumor-derived DNA activates STING leading to upregulation of IFN-beta and induction of antitumor T cells. The entire mtDNA from the cell lines was sequenced using next-generation sequencing (NGS) technology with independent sequencing of both strands in both directions, allowing identification of low-frequency heteroplasmy SNPs. There were 15 heteroplasmy SNPs showing a range from 3.4% to 40.5% occurrence in the K cybrid cell lines. Three H haplogroup cybrids possessed SNP heteroplasmy that ranged from 4.39% to 30.7%. The present study used qRT-PCR to determine if cybrids of H and K haplogroups differentially regulate expression levels of five cancer genes (BRAC1, ALK, PD1, EGFR, and HER2) and seven STING subunits genes (CGAS, TBK1, IRF3, IκBa, NFκB, TRAF2, and TNFRSF19). Some cybrids underwent siRNA knockdown of STING followed by qRT-PCR in order to determine the impact of STING on gene expression. Rho0 (lacking mtDNA) ARPE-19 cells were used to determine if mtDNA is required for the expression of the cancer genes studied. Our results showed that (a) K cybrids have lower expression levels for BRAC1, ALK, PD1, EGFR, IRF3, and TNFRSF19 genes but increased transcription for IκBa and NFκB compared to H cybrids; (b) STING KD decreases expression of EGFR in both H and K cybrids, and (c) PD1 expression is negligible in Rho0 cells. Our findings suggest that the STING DNA sensing pathway may be a previously unrecognized pathway to target modulation of cancer-related genes and the PD1 expression requires the presence of mtDNA.
Collapse
Affiliation(s)
- Kevin Schneider
- Department of Ophthalmology, Gavin Herbert Eye InstituteUniversity of California IrvineIrvineCaliforniaUSA
| | - Marilyn Chwa
- Department of Ophthalmology, Gavin Herbert Eye InstituteUniversity of California IrvineIrvineCaliforniaUSA
| | - Shari R. Atilano
- Department of Ophthalmology, Gavin Herbert Eye InstituteUniversity of California IrvineIrvineCaliforniaUSA
| | - Sonali Nashine
- Department of Ophthalmology, Gavin Herbert Eye InstituteUniversity of California IrvineIrvineCaliforniaUSA
| | - Nitin Udar
- Department of Ophthalmology, Gavin Herbert Eye InstituteUniversity of California IrvineIrvineCaliforniaUSA
| | - David S. Boyer
- Retina‐Vitreous Associates Medical GroupBeverly HillsCaliforniaUSA
| | - S. Michal Jazwinski
- Tulane Center for Aging and Department of MedicineTulane UniversityNew OrleansLouisianaUSA
| | - Michael V. Miceli
- Tulane Center for Aging and Department of MedicineTulane UniversityNew OrleansLouisianaUSA
| | - Anthony B. Nesburn
- Department of Ophthalmology, Gavin Herbert Eye InstituteUniversity of California IrvineIrvineCaliforniaUSA
- Cedars‐Sinai Medical CenterLos AngelesCaliforniaUSA
| | - Baruch D. Kuppermann
- Department of Ophthalmology, Gavin Herbert Eye InstituteUniversity of California IrvineIrvineCaliforniaUSA
| | - M. Cristina Kenney
- Department of Ophthalmology, Gavin Herbert Eye InstituteUniversity of California IrvineIrvineCaliforniaUSA
- Department of Pathology and Laboratory MedicineUniversity of California IrvineIrvineCaliforniaUSA
| |
Collapse
|
6
|
Nadeem U, Xie B, Xie EF, D'Souza M, Dao D, Sulakhe D, Skondra D. Using Advanced Bioinformatics Tools to Identify Novel Therapeutic Candidates for Age-Related Macular Degeneration. Transl Vis Sci Technol 2022; 11:10. [PMID: 35972434 PMCID: PMC9396676 DOI: 10.1167/tvst.11.8.10] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose Age-related macular degeneration (AMD) is the most common cause of aging-related blindness in the developing world. Although medications can slow progressive wet AMD, currently, no drugs to treat dry-AMD are available. We use a systems or in silico biology analysis to identify chemicals and drugs approved by the Food and Drug Administration for other indications that can be used to treat and prevent AMD. Methods We queried National Center for Biotechnology Information to identify genes associated with AMD, wet AMD, dry AMD, intermediate AMD, and geographic atrophy to date. We combined genes from various AMD subtypes to reflect distinct stages of disease. Enrichment analysis using the ToppGene platform predicted molecules that can influence AMD genes. Compounds without clinical indications or with deleterious effects were manually filtered. Results We identified several drug/chemical classes that can affect multiple genes involved in AMD. The drugs predicted from this analysis include antidiabetics, lipid-lowering agents, and antioxidants, which could theoretically be repurposed for AMD. Metformin was identified as the drug with the strongest association with wet AMD genes and is among the top candidates in all dry AMD subtypes. Curcumin, statins, and antioxidants are also among the top drugs correlating with AMD-risk genes. Conclusions We use a systematic computational process to discover potential therapeutic targets for AMD. Our systematic and unbiased approach can be used to guide targeted preclinical/clinical studies for AMD and other ocular diseases. Translational Relevance Advanced bioinformatics models identify novel chemicals and approved drug candidates that can be efficacious for different subtypes of AMD.
Collapse
Affiliation(s)
- Urooba Nadeem
- Department of Pathology, University of Chicago, Chicago, IL, USA
| | - Bingqing Xie
- Department of Medicine, University of Chicago, IL, USA
| | - Edward F Xie
- Chicago Medical School at Rosalind Franklin University of Medicine and Science, Chicago, IL, USA
| | - Mark D'Souza
- Center for Research Informatics, The University of Chicago, Chicago, IL, USA
| | - David Dao
- Department of Ophthalmology and Visual Science, University of Chicago, Chicago, IL, USA
| | | | - Dimitra Skondra
- Department of Ophthalmology and Visual Science, University of Chicago, Chicago, IL, USA
| |
Collapse
|
7
|
Zhang C, Owen LA, Lillvis JH, Zhang SX, Kim IK, DeAngelis MM. AMD Genomics: Non-Coding RNAs as Biomarkers and Therapeutic Targets. J Clin Med 2022; 11:jcm11061484. [PMID: 35329812 PMCID: PMC8954267 DOI: 10.3390/jcm11061484] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Revised: 02/22/2022] [Accepted: 03/01/2022] [Indexed: 12/04/2022] Open
Abstract
Age-related macular degeneration (AMD) is a progressive neurodegenerative disease that is the world’s leading cause of blindness in the aging population. Although the clinical stages and forms of AMD have been elucidated, more specific prognostic tools are required to determine when patients with early and intermediate AMD will progress into the advanced stages of AMD. Another challenge in the field has been the appropriate development of therapies for intermediate AMD and advanced atrophic AMD. After numerous negative clinical trials, an anti-C5 agent and anti-C3 agent have recently shown promising results in phase 3 clinical trials, in terms of slowing the growth of geographic atrophy, an advanced form of AMD. Interestingly, both drugs appear to be associated with an increased incidence of wet AMD, another advanced form of the disease, and will require frequent intravitreal injections. Certainly, there remains a need for other therapeutic agents with the potential to prevent progression to advanced stages of the disease. Investigation of the role and clinical utility of non-coding RNAs (ncRNAs) is a major advancement in biology that has only been minimally applied to AMD. In the following review, we discuss the clinical relevance of ncRNAs in AMD as both biomarkers and therapeutic targets.
Collapse
Affiliation(s)
- Charles Zhang
- Department of Ophthalmology, Ross Eye Institute, Jacobs School of Medicine and Biomedical Sciences, State University of New York, University at Buffalo, Buffalo, NY 14203, USA; (C.Z.); (L.A.O.); (J.H.L.); (S.X.Z.)
| | - Leah A. Owen
- Department of Ophthalmology, Ross Eye Institute, Jacobs School of Medicine and Biomedical Sciences, State University of New York, University at Buffalo, Buffalo, NY 14203, USA; (C.Z.); (L.A.O.); (J.H.L.); (S.X.Z.)
- Department of Ophthalmology and Visual Sciences, University of Utah School of Medicine, The University of Utah, Salt Lake City, UT 84132, USA
- Department of Population Health Sciences, University of Utah School of Medicine, The University of Utah, Salt Lake City, UT 84132, USA
- Department of Obstetrics and Gynecology, University of Utah School of Medicine, The University of Utah, Salt Lake City, UT 84132, USA
| | - John H. Lillvis
- Department of Ophthalmology, Ross Eye Institute, Jacobs School of Medicine and Biomedical Sciences, State University of New York, University at Buffalo, Buffalo, NY 14203, USA; (C.Z.); (L.A.O.); (J.H.L.); (S.X.Z.)
- Veterans Administration Western New York Healthcare System, Buffalo, NY 14212, USA
| | - Sarah X. Zhang
- Department of Ophthalmology, Ross Eye Institute, Jacobs School of Medicine and Biomedical Sciences, State University of New York, University at Buffalo, Buffalo, NY 14203, USA; (C.Z.); (L.A.O.); (J.H.L.); (S.X.Z.)
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, State University of New York, University at Buffalo, Buffalo, NY 14203, USA
- Neuroscience Graduate Program, Jacobs School of Medicine and Biomedical Sciences, State University of New York, University at Buffalo, Buffalo, NY 14203, USA
| | - Ivana K. Kim
- Retina Service, Massachusetts Eye & Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA 02114, USA
- Correspondence: (I.K.K.); (M.M.D.)
| | - Margaret M. DeAngelis
- Department of Ophthalmology, Ross Eye Institute, Jacobs School of Medicine and Biomedical Sciences, State University of New York, University at Buffalo, Buffalo, NY 14203, USA; (C.Z.); (L.A.O.); (J.H.L.); (S.X.Z.)
- Department of Ophthalmology and Visual Sciences, University of Utah School of Medicine, The University of Utah, Salt Lake City, UT 84132, USA
- Department of Population Health Sciences, University of Utah School of Medicine, The University of Utah, Salt Lake City, UT 84132, USA
- Veterans Administration Western New York Healthcare System, Buffalo, NY 14212, USA
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, State University of New York, University at Buffalo, Buffalo, NY 14203, USA
- Neuroscience Graduate Program, Jacobs School of Medicine and Biomedical Sciences, State University of New York, University at Buffalo, Buffalo, NY 14203, USA
- Genetics, Genomics and Bioinformatics Graduate Program, Jacobs School of Medicine and Biomedical Sciences, State University of New York, University at Buffalo, Buffalo, NY 14203, USA
- Correspondence: (I.K.K.); (M.M.D.)
| |
Collapse
|
8
|
Finnegan LK, Chadderton N, Kenna PF, Palfi A, Carty M, Bowie AG, Millington-Ward S, Farrar GJ. SARM1 Ablation Is Protective and Preserves Spatial Vision in an In Vivo Mouse Model of Retinal Ganglion Cell Degeneration. Int J Mol Sci 2022; 23:ijms23031606. [PMID: 35163535 PMCID: PMC8835928 DOI: 10.3390/ijms23031606] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 01/21/2022] [Accepted: 01/26/2022] [Indexed: 02/04/2023] Open
Abstract
The challenge of developing gene therapies for genetic forms of blindness is heightened by the heterogeneity of these conditions. However, mechanistic commonalities indicate key pathways that may be targeted in a gene-independent approach. Mitochondrial dysfunction and axon degeneration are common features of many neurodegenerative conditions including retinal degenerations. Here we explore the neuroprotective effect afforded by the absence of sterile alpha and Toll/interleukin-1 receptor motif-containing 1 (SARM1), a prodegenerative NADase, in a rotenone-induced mouse model of retinal ganglion cell loss and visual dysfunction. Sarm1 knockout mice retain visual function after rotenone insult, displaying preservation of photopic negative response following rotenone treatment in addition to significantly higher optokinetic response measurements than wild type mice following rotenone. Protection of spatial vision is sustained over time in both sexes and is accompanied by increased RGC survival and additionally preservation of axonal density in optic nerves of Sarm1−/− mice insulted with rotenone. Primary fibroblasts extracted from Sarm1−/− mice demonstrate an increased oxygen consumption rate relative to those from wild type mice, with significantly higher basal, maximal and spare respiratory capacity. Collectively, our data indicate that Sarm1 ablation increases mitochondrial bioenergetics and confers histological and functional protection in vivo in the mouse retina against mitochondrial dysfunction, a hallmark of many neurodegenerative conditions including a variety of ocular disorders.
Collapse
Affiliation(s)
- Laura K. Finnegan
- Department of Genetics, The School of Genetics and Microbiology, Trinity College Dublin, D02 VF25 Dublin, Ireland; (N.C.); (P.F.K.); (A.P.); (S.M.-W.); (G.J.F.)
- Correspondence:
| | - Naomi Chadderton
- Department of Genetics, The School of Genetics and Microbiology, Trinity College Dublin, D02 VF25 Dublin, Ireland; (N.C.); (P.F.K.); (A.P.); (S.M.-W.); (G.J.F.)
| | - Paul F. Kenna
- Department of Genetics, The School of Genetics and Microbiology, Trinity College Dublin, D02 VF25 Dublin, Ireland; (N.C.); (P.F.K.); (A.P.); (S.M.-W.); (G.J.F.)
- The Research Foundation, Royal Victoria Eye and Ear Hospital, D02 XK51 Dublin, Ireland
| | - Arpad Palfi
- Department of Genetics, The School of Genetics and Microbiology, Trinity College Dublin, D02 VF25 Dublin, Ireland; (N.C.); (P.F.K.); (A.P.); (S.M.-W.); (G.J.F.)
| | - Michael Carty
- Trinity Biomedical Sciences Institute, The School of Biochemistry and Immunology, Trinity College Dublin, D02 R590 Dublin, Ireland; (M.C.); (A.G.B.)
| | - Andrew G. Bowie
- Trinity Biomedical Sciences Institute, The School of Biochemistry and Immunology, Trinity College Dublin, D02 R590 Dublin, Ireland; (M.C.); (A.G.B.)
| | - Sophia Millington-Ward
- Department of Genetics, The School of Genetics and Microbiology, Trinity College Dublin, D02 VF25 Dublin, Ireland; (N.C.); (P.F.K.); (A.P.); (S.M.-W.); (G.J.F.)
| | - G. Jane Farrar
- Department of Genetics, The School of Genetics and Microbiology, Trinity College Dublin, D02 VF25 Dublin, Ireland; (N.C.); (P.F.K.); (A.P.); (S.M.-W.); (G.J.F.)
| |
Collapse
|
9
|
Fleckenstein M, Keenan TDL, Guymer RH, Chakravarthy U, Schmitz-Valckenberg S, Klaver CC, Wong WT, Chew EY. Age-related macular degeneration. Nat Rev Dis Primers 2021; 7:31. [PMID: 33958600 DOI: 10.1038/s41572-021-00265-2] [Citation(s) in RCA: 376] [Impact Index Per Article: 125.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 03/23/2021] [Indexed: 02/07/2023]
Abstract
Age-related macular degeneration (AMD) is the leading cause of legal blindness in the industrialized world. AMD is characterized by accumulation of extracellular deposits, namely drusen, along with progressive degeneration of photoreceptors and adjacent tissues. AMD is a multifactorial disease encompassing a complex interplay between ageing, environmental risk factors and genetic susceptibility. Chronic inflammation, lipid deposition, oxidative stress and impaired extracellular matrix maintenance are strongly implicated in AMD pathogenesis. However, the exact interactions of pathophysiological events that culminate in drusen formation and the associated degeneration processes remain to be elucidated. Despite tremendous advances in clinical care and in unravelling pathophysiological mechanisms, the unmet medical need related to AMD remains substantial. Although there have been major breakthroughs in the treatment of exudative AMD, no efficacious treatment is yet available to prevent progressive irreversible photoreceptor degeneration, which leads to central vision loss. Compelling progress in high-resolution retinal imaging has enabled refined phenotyping of AMD in vivo. These insights, in combination with clinicopathological and genetic correlations, have underscored the heterogeneity of AMD. Hence, our current understanding promotes the view that AMD represents a disease spectrum comprising distinct phenotypes with different mechanisms of pathogenesis. Hence, tailoring therapeutics to specific phenotypes and stages may, in the future, be the key to preventing irreversible vision loss.
Collapse
Affiliation(s)
- Monika Fleckenstein
- Department of Ophthalmology and Visual Science, John A. Moran Eye Center, University of Utah, Salt Lake City, UT, USA.
| | - Tiarnán D L Keenan
- Division of Epidemiology and Clinical Applications, National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Robyn H Guymer
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, Melbourne, VIC, Australia.,Ophthalmology, Department of Surgery, The University of Melbourne, Melbourne, VIC, Australia
| | - Usha Chakravarthy
- Department of Ophthalmology, Centre for Public Health, Queen's University of Belfast, Belfast, UK
| | - Steffen Schmitz-Valckenberg
- Department of Ophthalmology and Visual Science, John A. Moran Eye Center, University of Utah, Salt Lake City, UT, USA.,Department of Ophthalmology, University of Bonn, Bonn, Germany
| | - Caroline C Klaver
- Department of Ophthalmology, Erasmus MC, Rotterdam, Netherlands.,Department of Epidemiology, Erasmus MC, Rotterdam, Netherlands.,Department of Ophthalmology, Radboud Medical Center, Nijmegen, Netherlands.,Institute of Molecular and Clinical Ophthalmology, Basel, Switzerland
| | - Wai T Wong
- Section on Neuron-Glia Interactions in Retinal Disease, National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Emily Y Chew
- Division of Epidemiology and Clinical Applications, National Eye Institute, National Institutes of Health, Bethesda, MD, USA.
| |
Collapse
|
10
|
Cai H, Gong J, Noggle S, Paull D, Rizzolo LJ, Del Priore LV, Fields MA. Altered transcriptome and disease-related phenotype emerge only after fibroblasts harvested from patients with age-related macular degeneration are differentiated into retinal pigment epithelium. Exp Eye Res 2021; 207:108576. [PMID: 33895162 DOI: 10.1016/j.exer.2021.108576] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 03/03/2021] [Accepted: 04/07/2021] [Indexed: 11/30/2022]
Abstract
We have reported previously that retinal pigment epithelium (RPE) differentiated from induced pluripotent stem cells (iPSC) generated from fibroblasts of patients with age-related macular degeneration (AMD) exhibit a retinal degenerative disease phenotype and a distinct transcriptome compared to age-matched controls. Since the genetic composition of the iPSC and RPE are inherited from fibroblasts, we investigated whether differential behavior was present in the parental fibroblasts and iPSC prior to differentiation of the cell lines into RPE. Principal component analyses revealed significant overlap (essentially no differences) in the transcriptome of fibroblasts between AMD and controls. After reprogramming, there was no significant difference in the transcriptome of iPSC generated from AMD versus normal donors. In contrast, the transcriptome of RPE derived from iPSC segregated into two distinct clusters of AMD-derived cells versus controls. Interestingly, mitochondrial dysfunction in AMD-derived RPE was evident after approximately two months in culture. Moreover, these differences in mitochondrial dysfunction were not evident in the parental fibroblasts and iPSC. This study demonstrates an altered transcriptome and impaired mitochondrial function in RPE derived from AMD patients versus controls, and demonstrates these differences are not present in the original fibroblasts or iPSC. These results suggest that pathology in AMD is triggered upon differentiation of parent cells into RPE. More study of this phenomenon could advance the current understandings of the etiology of AMD and the development of novel therapeutic targets.
Collapse
Affiliation(s)
- Hui Cai
- Department of Ophthalmology and Visual Science, Yale University School of Medicine, 300 George St., Suite 8100, New Haven, CT, 06510, USA
| | - Jie Gong
- Department of Ophthalmology and Visual Science, Yale University School of Medicine, 300 George St., Suite 8100, New Haven, CT, 06510, USA
| | -
- The New York Stem Cell Foundation (NYSCF) Research Institute, 619 West 54th St., New York, NY, 10019, USA
| | - Scott Noggle
- The New York Stem Cell Foundation (NYSCF) Research Institute, 619 West 54th St., New York, NY, 10019, USA
| | - Daniel Paull
- The New York Stem Cell Foundation (NYSCF) Research Institute, 619 West 54th St., New York, NY, 10019, USA
| | - Lawrence J Rizzolo
- Department of Ophthalmology and Visual Science, Yale University School of Medicine, 300 George St., Suite 8100, New Haven, CT, 06510, USA; Department of Surgery, Yale University School of Medicine, PO Box 208062, New Haven, CT, 06520-8062, USA
| | - Lucian V Del Priore
- Department of Ophthalmology and Visual Science, Yale University School of Medicine, 300 George St., Suite 8100, New Haven, CT, 06510, USA
| | - Mark A Fields
- Department of Ophthalmology and Visual Science, Yale University School of Medicine, 300 George St., Suite 8100, New Haven, CT, 06510, USA.
| |
Collapse
|
11
|
Nicholson C, Ishii M, Annamalai B, Chandler K, Chwa M, Kenney MC, Shah N, Rohrer B. J or H mtDNA haplogroups in retinal pigment epithelial cells: Effects on cell physiology, cargo in extracellular vesicles, and differential uptake of such vesicles by naïve recipient cells. Biochim Biophys Acta Gen Subj 2021; 1865:129798. [PMID: 33217521 PMCID: PMC8396072 DOI: 10.1016/j.bbagen.2020.129798] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 10/19/2020] [Accepted: 10/23/2020] [Indexed: 01/11/2023]
Abstract
PURPOSE Extracellular vesicles (EVs) are predicted to represent the internal state of cells. In polarized RPE monolayers, EVs can mediate long-distance communication, requiring endocytosis via protein-protein interactions. EV uptake from oxidatively stressed donor cells triggers loss in transepithelial resistance (TER) in recipient monolayers mediated by HDAC6. Here, we examine EVs released from RPE cells with identical nuclear genes but different mitochondrial (mt)DNA haplogroups (H, J). J-cybrids produce less ATP, and the J-haplogroup is associated with a higher risk for age-related macular degeneration. METHODS Cells were grown as mature monolayers to either collect EVs from apical surfaces or to serve as naïve recipient cells. Transfer assays, transferring EVs to a recipient monolayer were performed, monitoring TER and EV-uptake. The presence of known EV surface proteins was quantified by protein chemistry. RESULTS H- and J-cybrids were confirmed to exhibit different levels of TER and energy metabolism. EVs from J-cybrids reduced TER in recipient ARPE-19 cells, whereas EVs from H-cybrids were ineffective. TER reduction was mediated by HDAC6 activity, and EV uptake required interaction between integrin and its ligands and surface proteoglycans. Protein quantifications confirmed elevated levels of fibronectin and annexin A2 on J-cybrid EVs. CONCLUSIONS We speculate that RPE EVs have a finite set of ligands (membrane proteoglycans and integrins and/or annexin A2) that are elevated in EVs from stressed cells; and that if EVs released by the RPE could be captured from serum, that they might provide a disease biomarker of RPE-dependent diseases.
Collapse
Affiliation(s)
- Crystal Nicholson
- Department of Ophthalmology, Medical University of South Carolina, Charleston, SC 29425, United States of America
| | - Masaaki Ishii
- Department of Ophthalmology, Medical University of South Carolina, Charleston, SC 29425, United States of America
| | - Balasubramaniam Annamalai
- Department of Ophthalmology, Medical University of South Carolina, Charleston, SC 29425, United States of America
| | - Kyrie Chandler
- Department of Ophthalmology, Medical University of South Carolina, Charleston, SC 29425, United States of America
| | - Marilyn Chwa
- Gavin Herbert Eye Institute, Department of Ophthalmology, University of California Irvine, Irvine, CA 92697, United States of America
| | - M Cristina Kenney
- Gavin Herbert Eye Institute, Department of Ophthalmology, University of California Irvine, Irvine, CA 92697, United States of America
| | - Navjot Shah
- Department of Ophthalmology, Medical University of South Carolina, Charleston, SC 29425, United States of America
| | - Bärbel Rohrer
- Department of Ophthalmology, Medical University of South Carolina, Charleston, SC 29425, United States of America; Department of Neurosciences Medical University of South Carolina, Charleston, SC 29425, United States of America; Ralph H. Johnson VA Medical Center, Charleston, SC 29401, United States of America.
| |
Collapse
|
12
|
Mitochondria: The Retina's Achilles' Heel in AMD. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1256:237-264. [PMID: 33848005 DOI: 10.1007/978-3-030-66014-7_10] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Strong experimental evidence from studies in human donor retinas and animal models supports the idea that the retinal pathology associated with age-related macular degeneration (AMD) involves mitochondrial dysfunction and consequent altered retinal metabolism. This chapter provides a brief overview of mitochondrial structure and function, summarizes evidence for mitochondrial defects in AMD, and highlights the potential ramifications of these defects on retinal health and function. Discussion of mitochondrial haplogroups and their association with AMD brings to light how mitochondrial genetics can influence disease outcome. As one of the most metabolically active tissues in the human body, there is strong evidence that disruption in key metabolic pathways contributes to AMD pathology. The section on retinal metabolism reviews cell-specific metabolic differences and how the metabolic interdependence of each retinal cell type creates a unique ecosystem that is disrupted in the diseased retina. The final discussion includes strategies for therapeutic interventions that target key mitochondrial pathways as a treatment for AMD.
Collapse
|
13
|
Crosstalk between Long-Term Sublethal Oxidative Stress and Detrimental Inflammation as Potential Drivers for Age-Related Retinal Degeneration. Antioxidants (Basel) 2020; 10:antiox10010025. [PMID: 33383836 PMCID: PMC7823845 DOI: 10.3390/antiox10010025] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Revised: 12/23/2020] [Accepted: 12/25/2020] [Indexed: 12/16/2022] Open
Abstract
Age-related retinal degenerations, including age-related macular degeneration (AMD), are caused by the loss of retinal pigmented epithelial (RPE) cells and photoreceptors. The pathogenesis of AMD, deeply linked to the aging process, also involves oxidative stress and inflammatory responses. However, the molecular mechanisms contributing to the shift from healthy aging to AMD are still poorly understood. Since RPE cells in the retina are chronically exposed to a pro-oxidant microenvironment throughout life, we simulated in vivo conditions by growing ARPE-19 cells in the presence of 10 μM H2O2 for several passages. This long-term oxidative insult induced senescence in ARPE-19 cells without affecting cell proliferation. Global proteomic analysis revealed a dysregulated expression in proteins involved in antioxidant response, mitochondrial homeostasis, and extracellular matrix organization. The analyses of mitochondrial functionality showed increased mitochondrial biogenesis and ATP generation and improved response to oxidative stress. The latter, however, was linked to nuclear factor-κB (NF-κB) rather than nuclear factor erythroid 2–related factor 2 (Nrf2) activation. NF-κB hyperactivation also resulted in increased pro-inflammatory cytokines expression and inflammasome activation. Moreover, in response to additional pro-inflammatory insults, senescent ARPE-19 cells underwent an exaggerated inflammatory reaction. Our results indicate senescence as an important link between chronic oxidative insult and detrimental chronic inflammation, with possible future repercussions for therapeutic interventions.
Collapse
|
14
|
Kaarniranta K, Uusitalo H, Blasiak J, Felszeghy S, Kannan R, Kauppinen A, Salminen A, Sinha D, Ferrington D. Mechanisms of mitochondrial dysfunction and their impact on age-related macular degeneration. Prog Retin Eye Res 2020; 79:100858. [PMID: 32298788 PMCID: PMC7650008 DOI: 10.1016/j.preteyeres.2020.100858] [Citation(s) in RCA: 266] [Impact Index Per Article: 66.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Revised: 03/18/2020] [Accepted: 03/19/2020] [Indexed: 12/21/2022]
Abstract
Oxidative stress-induced damage to the retinal pigment epithelium (RPE) is considered to be a key factor in age-related macular degeneration (AMD) pathology. RPE cells are constantly exposed to oxidative stress that may lead to the accumulation of damaged cellular proteins, lipids, nucleic acids, and cellular organelles, including mitochondria. The ubiquitin-proteasome and the lysosomal/autophagy pathways are the two major proteolytic systems to remove damaged proteins and organelles. There is increasing evidence that proteostasis is disturbed in RPE as evidenced by lysosomal lipofuscin and extracellular drusen accumulation in AMD. Nuclear factor-erythroid 2-related factor-2 (NFE2L2) and peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α) are master transcription factors in the regulation of antioxidant enzymes, clearance systems, and biogenesis of mitochondria. The precise cause of RPE degeneration and the onset and progression of AMD are not fully understood. However, mitochondria dysfunction, increased reactive oxygen species (ROS) production, and mitochondrial DNA (mtDNA) damage are observed together with increased protein aggregation and inflammation in AMD. In contrast, functional mitochondria prevent RPE cells damage and suppress inflammation. Here, we will discuss the role of mitochondria in RPE degeneration and AMD pathology focused on mtDNA damage and repair, autophagy/mitophagy signaling, and regulation of inflammation. Mitochondria are putative therapeutic targets to prevent or treat AMD.
Collapse
Affiliation(s)
- Kai Kaarniranta
- Department of Ophthalmology, Institute of Clinical Medicine, University of Eastern Finland and Kuopio University Hospital, P.O. Box 1627, FI-70211, Kuopio, Finland.
| | - Hannu Uusitalo
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland and Tays Eye Centre, Tampere University Hospital, P.O.Box 2000, 33521 Tampere, Finland
| | - Janusz Blasiak
- Department of Molecular Genetics, Faculty of Biology and Environmental Protection, University of Lodz, 90-236, Lodz, Poland
| | - Szabolcs Felszeghy
- Department of Biomedicine, Faculty of Health Sciences, University of Eastern Finland, P.O. Box 1627, FI-70211, Kuopio, Finland
| | - Ram Kannan
- The Stephen J. Ryan Initiative for Macular Research (RIMR), Doheny Eye Institute, 1355 San Pablo St, Los Angeles, CA, 90033, USA
| | - Anu Kauppinen
- School of Pharmacy, Faculty of Health Sciences, University of Eastern Finland, P.O. Box 1627, FI-70211, Kuopio, Finland
| | - Antero Salminen
- Department of Neurology, Institute of Clinical Medicine, University of Eastern Finland, P.O. Box 1627, FI-70211, Kuopio, Finland
| | - Debasish Sinha
- Glia Research Laboratory, Department of Ophthalmology, University of Pittsburgh, 4401 Penn Avenue, Pittsburgh, PA, PA 15224, USA; Wilmer Eye Institute, The Johns Hopkins University School of Medicine, Room M035 Robert and Clarice Smith Bldg, 400 N Broadway, Baltimore, MD, 21287, USA
| | - Deborah Ferrington
- Department of Ophthalmology and Visual Neurosciences, 2001 6th St SE, University of Minnesota, Minneapolis, MN 55455, USA
| |
Collapse
|
15
|
Jabbehdari S, Handa JT. Oxidative stress as a therapeutic target for the prevention and treatment of early age-related macular degeneration. Surv Ophthalmol 2020; 66:423-440. [PMID: 32961209 DOI: 10.1016/j.survophthal.2020.09.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 09/10/2020] [Accepted: 09/14/2020] [Indexed: 12/13/2022]
Abstract
Age-related macular degeneration, the leading cause of irreversible visual loss among older adults in developed countries, is a chronic, multifactorial, and progressive disease with the development of painless, central vision loss. Retinal pigment epithelial cell dysfunction is a core change in age-related macular degeneration that results from aging and the accumulated effects of genetic and environmental factors that, in part, is both caused by and leads to oxidative stress. In this review, we describe the role of oxidative stress, the cytoprotective oxidative stress pathways, and the impact of oxidative stress on critical cellular processes involved in age-related macular degeneration pathobiology. We also offer targeted therapy that may define how antioxidant therapy can either prevent or improve specific stages of age-related macular degeneration.
Collapse
Affiliation(s)
- Sayena Jabbehdari
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, Illinois, USA
| | - James T Handa
- Wilmer Eye Institute, Johns Hopkins School of Medicine, Baltimore, Maryland, USA.
| |
Collapse
|
16
|
Macular impairment in mitochondrial diseases: a potential biomarker of disease severity. Sci Rep 2020; 10:8554. [PMID: 32444699 PMCID: PMC7244507 DOI: 10.1038/s41598-020-65482-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Accepted: 05/05/2020] [Indexed: 11/08/2022] Open
Abstract
The high-energy demands of the retina are thought to contribute to its particular vulnerability to mitochondrial dysfunction. Photoreceptors are the cells with the higher oxygen consumption within the retina, and among these, the cones contain more mitochondria and have a higher energy demand than rods. A cohort of twenty-two patients with genetically-defined mitochondrial diseases (MDs) were enrolled to determine if the macula is functionally and anatomically impaired in these metabolic disorders. Visual acuity and fERG amplitude of patients with primary mitochondrial dysfunction were reduced compared to controls. Furthermore, SD-OCT layer segmentation showed a reduction of retinal and outer nuclear layer (ONL) volume in the macula of the patients. fERG amplitude showed a positive correlation with both ONL volume and thickness. A negative relationship was noted between fERG amplitude and disease severity assessed with Newcastle Mitochondrial Disease Adult Scale. In conclusion, MDs are associated with functional and anatomical alteration of macular cone system, characterized by its strong correlation with clinical disease severity suggesting a role as a potential biomarker of primary mitochondrial disorders.
Collapse
|
17
|
Mehrzadi S, Hemati K, Reiter RJ, Hosseinzadeh A. Mitochondrial dysfunction in age-related macular degeneration: melatonin as a potential treatment. Expert Opin Ther Targets 2020; 24:359-378. [PMID: 32116056 DOI: 10.1080/14728222.2020.1737015] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Introduction: Age-related Macular Degeneration (AMD), a retinal neurodegenerative disease is the most common cause of blindness among the elderly in developed countries. The impairment of mitochondrial biogenesis has been reported in human retinal pigment epithelium (RPE) cells affected by AMD. Oxidative/nitrosative stress plays an important role in AMD development. The mitochondrial respiratory system is considered a major site of reactive oxygen species (ROS) generation. During aging, insufficient free radical scavenger systems, impairment of DNA repair mechanisms and reduction of mitochondrial degradation and turnover contribute to the massive accumulation of ROS disrupting mitochondrial function. Impaired mitochondrial function leads to the decline in the autophagic capacity and induction of inflammation and apoptosis in human RPE cells affected by AMD.Areas covered: This article evaluates the ameliorative effect of melatonin on AMD and examines AMD pathogenesis with an emphasis on mitochondrial dysfunction. It also considers the potential effects of melatonin on mitochondrial function.Expert opinion: The effect of melatonin on mitochondrial function results in the reduction of oxidative stress, inflammation and apoptosis in the retina; these findings demonstrate that melatonin has the potential to prevent and treat AMD.
Collapse
Affiliation(s)
- Saeed Mehrzadi
- Razi Drug Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Karim Hemati
- Department of Anesthesiology, Iran University of Medical Sciences, Tehran, Iran
| | - Russel J Reiter
- Department of Cellular and Structural Biology, University of Texas Health Science Center, San Antonio, TX, USA
| | - Azam Hosseinzadeh
- Razi Drug Research Center, Iran University of Medical Sciences, Tehran, Iran
| |
Collapse
|
18
|
Predictive genetics for AMD: Hype and hopes for genetics-based strategies for treatment and prevention. Exp Eye Res 2019; 191:107894. [PMID: 31862397 DOI: 10.1016/j.exer.2019.107894] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 10/14/2019] [Accepted: 12/04/2019] [Indexed: 01/18/2023]
Abstract
Age-related macular degeneration (AMD) is a complex disease with multiple genetic and environmental risk factors. In the age of molecular genetics, many investigators have established a link between genes and development or progression of the disease. This later evolved to determine whether phenotypic features of AMD have distinct genetic profiles. Molecular genetics have subsequently been introduced as factors in risk assessment models, increasing the predictive value of these tools. Models seek to predict either development or progression of disease, and different AMD-related genes aid our understanding of these respective features. Several investigators have attempted to link molecular genetics with treatment response, but results and their clinical significance vary. Ocular and systemic biomarkers may interact with established genes, promising future routes of ongoing clinical assessment. Our understanding of AMD molecular genetics is not yet sufficient to recommend routine testing, despite its utility in the research setting. Clinicians must be wary of misusing population-based risk models from genetic and biomarker associations, as they are not necessarily relevant for individual counseling. This review addresses the known uses of predictive genetics, and suggests future directions.
Collapse
|
19
|
Handa JT, Bowes Rickman C, Dick AD, Gorin MB, Miller JW, Toth CA, Ueffing M, Zarbin M, Farrer LA. A systems biology approach towards understanding and treating non-neovascular age-related macular degeneration. Nat Commun 2019; 10:3347. [PMID: 31350409 PMCID: PMC6659646 DOI: 10.1038/s41467-019-11262-1] [Citation(s) in RCA: 169] [Impact Index Per Article: 33.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Accepted: 07/03/2019] [Indexed: 12/20/2022] Open
Abstract
Age-related macular degeneration (AMD) is the most common cause of blindness among the elderly in the developed world. While treatment is effective for the neovascular or “wet” form of AMD, no therapy is successful for the non-neovascular or “dry” form. Here we discuss the current knowledge on dry AMD pathobiology and propose future research directions that would expedite the development of new treatments. In our view, these should emphasize system biology approaches that integrate omic, pharmacological, and clinical data into mathematical models that can predict disease onset and progression, identify biomarkers, establish disease causing mechanisms, and monitor response to therapy. No effective therapies exist for dry age-related macular degeneration. In this perspective, the authors propose that research should emphasize system biology approaches that integrate various ‘omics’ data into mathematical models to establish pathogenic mechanisms on which to design novel treatments, and identify biomarkers that predict disease progression and therapeutic response.
Collapse
Affiliation(s)
- James T Handa
- Wilmer Eye Institute, Johns Hopkins University, Baltimore, 21287, MD, USA.
| | - Cathy Bowes Rickman
- Department of Ophthalmology, Duke University Medical Center, Durham, 27708, NC, USA
| | - Andrew D Dick
- Translational Health Sciences (Ophthalmology), University of Bristol, Bristol, BS8 1TH, UK.,University College London, Institute of Ophthalmology and the National Institute for Health Research Biomedical Research Centre, Moorfields Eye Hospital and UCL-Institute of Ophthalmology, London, WC1E 6BT, UK
| | - Michael B Gorin
- Department of Ophthalmology, Jules Stein Eye Institute, David Geffen School of Medicine, UCLA, Los Angeles, 90095, CA, USA.,Brain Research Institute, UCLA, Los Angeles, 90095, CA, USA
| | - Joan W Miller
- Retina Service, Massachusetts Eye and Ear, Harvard Ophthalmology AMD Center of Excellence, Department of Ophthalmology, Harvard Medical School, Boston, 02114, MA, USA
| | - Cynthia A Toth
- Department of Ophthalmology, Duke University Medical Center, Durham, 27708, NC, USA
| | - Marius Ueffing
- Department of Ophthalmology, Institute for Ophthalmic Research, University of Tübingen, Tübingen, D-72076, Germany
| | - Marco Zarbin
- Institute of Ophthalmology and Visual Science, New Jersey Medical School, Rutgers University, Newark, 07103, NJ, USA
| | - Lindsay A Farrer
- Departments of Medicine (Biomedical Genetics), Neurology, Ophthalmology, Epidemiology, and Biostatistics, Boston University Schools of Medicine and Public Health, Boston, 02118, MA, USA.
| |
Collapse
|
20
|
Role of Mitochondrial DNA Damage in ROS-Mediated Pathogenesis of Age-Related Macular Degeneration (AMD). Int J Mol Sci 2019; 20:ijms20102374. [PMID: 31091656 PMCID: PMC6566654 DOI: 10.3390/ijms20102374] [Citation(s) in RCA: 116] [Impact Index Per Article: 23.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Revised: 04/17/2019] [Accepted: 04/28/2019] [Indexed: 12/19/2022] Open
Abstract
Age-related macular degeneration (AMD) is a complex eye disease that affects millions of people worldwide and is the main reason for legal blindness and vision loss in the elderly in developed countries. Although the cause of AMD pathogenesis is not known, oxidative stress-related damage to retinal pigment epithelium (RPE) is considered an early event in AMD induction. However, the precise cause of such damage and of the induction of oxidative stress, including related oxidative effects occurring in RPE and the onset and progression of AMD, are not well understood. Many results point to mitochondria as a source of elevated levels of reactive oxygen species (ROS) in AMD. This ROS increase can be associated with aging and effects induced by other AMD risk factors and is correlated with damage to mitochondrial DNA. Therefore, mitochondrial DNA (mtDNA) damage can be an essential element of AMD pathogenesis. This is supported by many studies that show a greater susceptibility of mtDNA than nuclear DNA to DNA-damaging agents in AMD. Therefore, the mitochondrial DNA damage reaction (mtDDR) is important in AMD prevention and in slowing down its progression as is ROS-targeting AMD therapy. However, we know far less about mtDNA than its nuclear counterparts. Further research should measure DNA damage in order to compare it in mitochondria and the nucleus, as current methods have serious disadvantages.
Collapse
|
21
|
Núñez-Álvarez C, Suárez-Barrio C, del Olmo Aguado S, Osborne NN. Blue light negatively affects the survival of ARPE19 cells through an action on their mitochondria and blunted by red light. Acta Ophthalmol 2019; 97:e103-e115. [PMID: 30198155 DOI: 10.1111/aos.13812] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Accepted: 04/08/2018] [Indexed: 12/18/2022]
Abstract
PURPOSE To ascertain whether red light, known to enhance mitochondrial function, can blunt a blue light insult to ARPE19 cells in culture. METHODS Semi-confluent ARPE19 cells cultured in 10% FBS were subjected to various regimes of treatment with blue (465-475 nm, 800 lux, 26 W/m2 ) and red (625-635 nm, 950 lux, 6.5 W/m2 ) light, as well as with toxins that inactivate specific enzymes associated with mitochondrial oxidative phosphorylation. Cultures were then analysed for cell viability (MTT assay), mitochondrial status (JC-1), ROS formation, immunocytochemistry and the activation of specific proteins by electrophoresis/Western blotting. In addition, ARPE19 cells were cultured in polycarbonate membrane inserts in culture medium containing 1% FBS. Such cultures were exposed to cycles of red, blue or a combination of red and blue light for up to 6 weeks. Culture medium was changed and the trans-epithelium membrane resistance (TER) of the inserts-containing cells was measured twice weekly. RESULTS ARPE19 cells in culture are affected negatively when exposed to blue light. This is indicated by a loss of viability, a depolarization of their mitochondria and a stimulation of ROS. Moreover, blue light causes an up-regulation of HO-1 and phospho-p-38-MAPK and a cleavage of apoptosis inhibitory factor, proteins which are all known to be activated during cell death. All of these negative effects of blue light are significantly blunted by the red light administered after the blue light insult in each case. ARPE19 cell loss of viability and mitochondrial potential caused by toxins that inhibit specific mitochondrial enzyme complexes was additive to an insult delivered by blue light in each case. After a time, ARPE19 cells in culture express the tight junction protein ZO-1, which is affected by blue light. The development of tight junctions between ARPE19 cells grown in inserts reached a steady peak of resistance after about 40 days and then increased very slightly over the next 40 days when still in darkness. However, maximum resistance was significantly attenuated, when cultures were treated with cycles of blue light after the initial 40 days in the dark and counteracted significantly when the blue light cycle insult was combined with red light. CONCLUSION Blue light affects mitochondrial function and also the development tight junctions between ARPE19 cells, which results in a loss of cell viability. Importantly, red light delivered after a blue light insult is significantly blunted. These findings argue for the therapeutic use of red light as a noninvasive procedure to attenuate insults caused by blue light and other insults to retinal pigment epithelial cell mitochondria that are likely to occur in age-related macular degeneration.
Collapse
|
22
|
Chinnery PF, Gomez-Duran A. Oldies but Goldies mtDNA Population Variants and Neurodegenerative Diseases. Front Neurosci 2018; 12:682. [PMID: 30369864 PMCID: PMC6194173 DOI: 10.3389/fnins.2018.00682] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Accepted: 09/10/2018] [Indexed: 12/31/2022] Open
Abstract
mtDNA is transmitted through the maternal line and its sequence variability, which is population specific, is assumed to be phenotypically neutral. However, several studies have shown associations between the variants defining some genetic backgrounds and the susceptibility to several pathogenic phenotypes, including neurodegenerative diseases. Many of these studies have found that some of these variants impact many of these phenotypes, including the ones defining the Caucasian haplogroups H, J, and Uk, while others, such as the ones defining the T haplogroup, have phenotype specific associations. In this review, we will focus on those that have shown a pleiotropic effect in population studies in neurological diseases. We will also explore their bioenergetic and genomic characteristics in order to provide an insight into the role of these variants in disease. Given the importance of mitochondrial population variants in neurodegenerative diseases a deeper analysis of their effects might unravel new mechanisms of disease and help design new strategies for successful treatments.
Collapse
Affiliation(s)
- Patrick F Chinnery
- Department of Clinical Neurosciences, School of Clinical Medicine, University of Cambridge, Cambridge, United Kingdom.,Medical Research Council-Mitochondrial Biology Unit, Cambridge Biomedical Campus, Cambridge, United Kingdom
| | - Aurora Gomez-Duran
- Department of Clinical Neurosciences, School of Clinical Medicine, University of Cambridge, Cambridge, United Kingdom.,Medical Research Council-Mitochondrial Biology Unit, Cambridge Biomedical Campus, Cambridge, United Kingdom
| |
Collapse
|
23
|
Hyttinen JMT, Viiri J, Kaarniranta K, Błasiak J. Mitochondrial quality control in AMD: does mitophagy play a pivotal role? Cell Mol Life Sci 2018; 75:2991-3008. [PMID: 29777261 PMCID: PMC11105454 DOI: 10.1007/s00018-018-2843-7] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Revised: 04/25/2018] [Accepted: 05/16/2018] [Indexed: 01/05/2023]
Abstract
Age-related macular degeneration (AMD) is the predominant cause of visual loss in old people in the developed world, whose incidence is increasing. This disease is caused by the decrease in macular function, due to the degeneration of retinal pigment epithelium (RPE) cells. The aged retina is characterised by increased levels of reactive oxygen species (ROS), impaired autophagy, and DNA damage that are linked to AMD pathogenesis. Mitophagy, a mitochondria-specific type of autophagy, is an essential part of mitochondrial quality control, the collective mechanism responsible for this organelle's homeostasis. The abundance of ROS, DNA damage, and the excessive energy consumption in the ageing retina all contribute to the degeneration of RPE cells and their mitochondria. We discuss the role of mitophagy in the cell and argue that its impairment may play a role in AMD pathogenesis. Thus, mitophagy as a potential therapeutic target in AMD and other degenerative diseases is as well explored.
Collapse
Affiliation(s)
- Juha M T Hyttinen
- Department of Ophthalmology, Institute of Clinical Medicine, University of Eastern Finland, P.O. Box 1627, 70211, Kuopio, Finland.
| | - Johanna Viiri
- Department of Ophthalmology, Institute of Clinical Medicine, University of Eastern Finland, P.O. Box 1627, 70211, Kuopio, Finland
| | - Kai Kaarniranta
- Department of Ophthalmology, Institute of Clinical Medicine, University of Eastern Finland, P.O. Box 1627, 70211, Kuopio, Finland
- Department of Ophthalmology, Kuopio University Hospital, P.O. Box 100, 70029 KYS, Kuopio, Finland
| | - Janusz Błasiak
- Department of Molecular Genetics, University of Łódź, Pomorska 141/143, 90-236, Łódź, Poland
| |
Collapse
|
24
|
Persad PJ, Heid IM, Weeks DE, Baird PN, de Jong EK, Haines JL, Pericak-Vance MA, Scott WK. Joint Analysis of Nuclear and Mitochondrial Variants in Age-Related Macular Degeneration Identifies Novel Loci TRPM1 and ABHD2/RLBP1. Invest Ophthalmol Vis Sci 2017; 58:4027-4038. [PMID: 28813576 PMCID: PMC5559178 DOI: 10.1167/iovs.17-21734] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Purpose Presently, 52 independent nuclear single nucleotide polymorphisms (nSNPs) have been associated with age-related macular degeneration (AMD) but their effects do not explain all its variance. Genetic interactions between the nuclear and mitochondrial (mt) genome may unearth additional genetic loci previously unassociated with AMD risk. Methods Joint effects of nSNPs and selected mtSNPs were analyzed by two degree of freedom (2df) joint tests of association in the International AMD Genomics Consortium (IAMDGC) dataset (17,832 controls and 16,144 advanced AMD cases of European ancestry). Subjects were genotyped on the Illumina HumanCoreExome array. After imputation using MINIMAC and the 1000 Genomes Project Phase I reference panel, pairwise linkage disequilibrium pruning, and quality control, 3.9 million nSNPs were analyzed for interaction with mtSNPs chosen based on association in this dataset or publications: A4917G, T5004C, G12771A, and C16069T. Results Novel locus TRPM1 was identified with genome-wide significant joint effects (P < 5.0 × 10−8) of two intronic TRPM1 nSNPs and AMD-associated nonsynonymous MT-ND2 mtSNP A4917G. Stratified analysis by mt allele identified an association only in 4917A (major allele) carriers (P = 4.4 × 10−9, odds ratio [OR] = 0.90, 95% confidence interval [CI] = 0.87–0.93). Intronic and intergenic ABHD2/RLBP1 nSNPs demonstrated genome-wide significant joint effects (2df joint test P values from 1.8 × 10−8 to 4.9 × 10−8) and nominally statistically significant interaction effects with MT-ND5 synonymous mtSNP G12771A. Although a positive association was detected in both strata, the association was stronger in 12771A subjects (P = 0.0020, OR = 2.17, 95% CI = 1.34–3.60). Conclusions These results show that joint tests of main effects and gene–gene interaction reveal associations at some novel loci that were missed when considering main effects alone.
Collapse
Affiliation(s)
- Patrice J Persad
- John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, Florida, United States
| | - Iris M Heid
- Department of Genetic Epidemiology, University of Regensburg, Regensburg, Germany
| | - Daniel E Weeks
- Department of Human Genetics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, Pennsylvania, United States.,Department of Biostatistics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, Pennsylvania, United States
| | - Paul N Baird
- Centre for Eye Research Australia, Department of Surgery (Ophthalmology) University of Melbourne, Royal Victorian Eye and Ear Hospital, East Melbourne, Victoria, Australia
| | - Eiko K de Jong
- Department of Ophthalmology, Donders Institute for Brain, Cognition, and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Jonathan L Haines
- Department of Population and Quantitative Health Sciences, Case Western Reserve University, Cleveland, Ohio, United States
| | - Margaret A Pericak-Vance
- John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, Florida, United States
| | - William K Scott
- John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, Florida, United States
| | | |
Collapse
|
25
|
The impact of oxidative stress and inflammation on RPE degeneration in non-neovascular AMD. Prog Retin Eye Res 2017; 60:201-218. [PMID: 28336424 DOI: 10.1016/j.preteyeres.2017.03.002] [Citation(s) in RCA: 487] [Impact Index Per Article: 69.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Revised: 03/13/2017] [Accepted: 03/14/2017] [Indexed: 02/07/2023]
Abstract
The retinal pigment epithelium (RPE) is a highly specialized, unique epithelial cell that interacts with photoreceptors on its apical side and with Bruch's membrane and the choriocapillaris on its basal side. Due to vital functions that keep photoreceptors healthy, the RPE is essential for maintaining vision. With aging and the accumulated effects of environmental stresses, the RPE can become dysfunctional and die. This degeneration plays a central role in age-related macular degeneration (AMD) pathobiology, the leading cause of blindness among the elderly in western societies. Oxidative stress and inflammation have both physiological and potentially pathological roles in RPE degeneration. Given the central role of the RPE, this review will focus on the impact of oxidative stress and inflammation on the RPE with AMD pathobiology. Physiological sources of oxidative stress as well as unique sources from photo-oxidative stress, the phagocytosis of photoreceptor outer segments, and modifiable factors such as cigarette smoking and high fat diet ingestion that can convert oxidative stress into a pathological role, and the negative impact of impairing the cytoprotective roles of mitochondrial dynamics and the Nrf2 signaling system on RPE health in AMD will be discussed. Likewise, the response by the innate immune system to an inciting trigger, and the potential role of local RPE production of inflammation, as well as a potential role for damage by inflammation with chronicity if the inciting trigger is not neutralized, will be debated.
Collapse
|
26
|
Riazi-Esfahani M, Kuppermann BD, Kenney MC. The Role of Mitochondria in AMD: Current Knowledge and Future Applications. J Ophthalmic Vis Res 2017; 12:424-428. [PMID: 29090054 PMCID: PMC5644411 DOI: 10.4103/jovr.jovr_182_17] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Mitochondria are organelles which comprise the main respiratory machinery in the eukaryotic cells. In addition to their crucial role in energy production, they have profound effects on apoptosis and retrograde signaling to nucleus. Mitochondria have their own DNA, which codes for different proteins mostly involved in oxidative phosphorylation. Significant changes in the mitochondria of retinal pigment epithelium have been reported in age-related macular degeneration (AMD), which is correlated with the severity of the disease. Cybrid cell lines that have identical nuclei but mitochondria from different individuals can provide a unique means for studying the relationship between mitochondria and AMD. Different approaches for protection of mitochondria have been introduced which can be considered as potential future treatments for AMD and other age- related disorders.
Collapse
Affiliation(s)
- Mohammad Riazi-Esfahani
- Department of Ophthalmology, Gavin Herbert Eye Institute, University of California Irvine, Irvine, California, USA.,Eye Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Baruch D Kuppermann
- Department of Ophthalmology, Gavin Herbert Eye Institute, University of California Irvine, Irvine, California, USA.,Department of Biomedical Engineering, University of California Irvine, Irvine, California, USA
| | - M Cristina Kenney
- Department of Ophthalmology, Gavin Herbert Eye Institute, University of California Irvine, Irvine, California, USA.,Department of Pathology and Laboratory Medicine, University of California Irvine, Irvine, CA, USA
| |
Collapse
|
27
|
Male-specific association between MT-ND4 11719 A/G polymorphism and ulcerative colitis: a mitochondria-wide genetic association study. BMC Gastroenterol 2016; 16:118. [PMID: 27716073 PMCID: PMC5048482 DOI: 10.1186/s12876-016-0509-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Accepted: 08/02/2016] [Indexed: 12/17/2022] Open
Abstract
Background Ulcerative colitis (UC) is a chronic inflammatory disorder of still unknown pathogenesis. Increasing evidence indicates that alterations in mitochondrial respiration and thus adenosine triphosphate (ATP) production are involved. This may contribute to mucosal energy deficiency and subsequently intestinal barrier malfunction, which is accepted to be a major hallmark of UC. Genetic alterations of the mitochondrial genome are one cause of mitochondrial dysfunction. However, less is known about mitochondrial gene polymorphisms in UC. Therefore, we aimed at identifying genetic associations between mitochondrial polymorphisms and UC. Methods German UC cases (n = 1062) and German healthy controls (n = 3030) were genotyped using the Affymetrix Genome-Wide Human SNP Array 6.0. The primary association analysis was to test for associations between mitochondrial single nucleotide polymorphisms (SNPs) and UC using Fisher’s exact test in the total sample and stratified by sex. In addition, we tested for associations between mitochondrial haplogroups and UC and for interactions between the most promising mitochondrial SNPs and nuclear SNPs. An independent set of German subjects with 1625 UC cases and 3575 controls was used for replication. Results We identified a genetic association between the MT-ND4 11719 A/G polymorphism and UC in the subgroup of males (rs2853495; odds ratio, 1.40; 95 % confidence interval, 1.13 to 1.73; p = 0.002). This association was replicated in the second independent cohort. In the association analysis based on mitochondrial haplogroups the lowest p values were reached for haplogroups HV and T (p = 0.029 and 0.035). Haplogroup HV is determined by the mitochondrial 11719 A/G polymorphism. Accordingly, this association was only found in the subgroup of males (p = 0.009). Conclusions For the first time, we observed an association between the MT-ND4 11719 A/G polymorphism and UC. The gene MT-ND4 encodes for a subunit of the mitochondrial electron transport chain complex I, which is pivotal for ATP production and might therefore contribute to mucosal energy deficiency. The male-specific association indicates differences between males and females concerning the impact of mitochondrial gene polymorphisms on the development of UC. Further investigations of the functional mechanism underlying this association and the relevance of the gender-specificity are highly warranted. Electronic supplementary material The online version of this article (doi:10.1186/s12876-016-0509-1) contains supplementary material, which is available to authorized users.
Collapse
|
28
|
Boya P, Esteban-Martínez L, Serrano-Puebla A, Gómez-Sintes R, Villarejo-Zori B. Autophagy in the eye: Development, degeneration, and aging. Prog Retin Eye Res 2016; 55:206-245. [PMID: 27566190 DOI: 10.1016/j.preteyeres.2016.08.001] [Citation(s) in RCA: 162] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2016] [Revised: 08/15/2016] [Accepted: 08/18/2016] [Indexed: 02/06/2023]
Abstract
Autophagy is a catabolic pathway that promotes the degradation and recycling of cellular components. Proteins, lipids, and even whole organelles are engulfed in autophagosomes and delivered to the lysosome for elimination. In response to stress, autophagy mediates the degradation of cell components, which are recycled to generate the nutrients and building blocks required to sustain cellular homeostasis. Moreover, it plays an important role in cellular quality control, particularly in neurons, in which the total burden of altered proteins and damaged organelles cannot be reduced by redistribution to daughter cells through cell division. Research has only begun to examine the role of autophagy in the visual system. The retina, a light-sensitive tissue, detects and transmits electrical impulses through the optic nerve to the visual cortex in the brain. Both the retina and the eye are exposed to a variety of environmental insults and stressors, including genetic mutations and age-associated alterations that impair their function. Here, we review the main studies that have sought to explain autophagy's importance in visual function. We describe the role of autophagy in retinal development and cell differentiation, and discuss the implications of autophagy dysregulation both in physiological aging and in important diseases such as age-associated macular degeneration and glaucoma. We also address the putative role of autophagy in promoting photoreceptor survival and discuss how selective autophagy could provide alternative means of protecting retinal cells. The findings reviewed here underscore the important role of autophagy in maintaining proper retinal function and highlight novel therapeutic approaches for blindness and other diseases of the eye.
Collapse
Affiliation(s)
- Patricia Boya
- Autophagy Lab, Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu 9, 28040, Madrid, Spain.
| | - Lorena Esteban-Martínez
- Autophagy Lab, Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu 9, 28040, Madrid, Spain
| | - Ana Serrano-Puebla
- Autophagy Lab, Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu 9, 28040, Madrid, Spain
| | - Raquel Gómez-Sintes
- Autophagy Lab, Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu 9, 28040, Madrid, Spain
| | - Beatriz Villarejo-Zori
- Autophagy Lab, Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu 9, 28040, Madrid, Spain
| |
Collapse
|
29
|
Mohanty K, Dada R, Dada T. Neurodegenerative Eye Disorders: Role of Mitochondrial Dynamics and Genomics. Asia Pac J Ophthalmol (Phila) 2016; 5:293-9. [PMID: 27101384 DOI: 10.1097/apo.0000000000000203] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
As a major source of cellular energy, mitochondria are critical for optimal ocular function. They are also essential for cell differentiation and survival. Mitochondrial mutations and oxidative damage to the mitochondrial DNA are important factors underlying the pathology of many ocular disorders. With increasing age, mitochondrial DNA damage accumulates and results in several eye diseases. It is evident that the mitochondrial genome is more susceptible to stress and damage than the nuclear genome, as it lacks histone protection, a nucleotide excision repair system, and recombination repair, and it is the source and target of free radicals. Accumulation of mitochondrial mutations beyond a certain threshold explains the marked variations in phenotypes seen in mitochondrial diseases and the molecular mechanisms related to the pathogenesis of several chronic disorders in the eye. This review details the structure and function of mitochondria and the mitochondrial genome along with the mitochondrial involvement in various neurodegenerative ophthalmic disorders.
Collapse
Affiliation(s)
- Kuldeep Mohanty
- From the *Department of Ophthalmology, Dr. Rajendra Prasad Centre for Ophthalmic Sciences, AIIMS, New Delhi, India; and †Laboratory for Molecular Reproduction and Genetics, Department of Anatomy, AIIMS, New Delhi, India
| | | | | |
Collapse
|
30
|
Zhang Y, Zhao Y, Wen S, Yan R, Yang Q, Chen H. Associations of mitochondrial haplogroups and mitochondrial DNA copy numbers with end-stage renal disease in a Han population. Mitochondrial DNA A DNA Mapp Seq Anal 2016; 28:725-731. [PMID: 27159351 DOI: 10.1080/24701394.2016.1177038] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Mitochondrial DNA (mtDNA) is closely related to mitochondrion function, and variations have been suggested to be involved in pathogenesis of complex diseases. The present study sought to elucidate mitochondrial haplogroups and mtDNA copy number in end-stage renal disease (ESRD) in a Han population. First, the mitochondrial haplogroups of 37 ESRD patients were clustered into several haplogroups, and haplogroup A & D were taken as the candidate risk haplogroups for ESRD. Second, the frequencies of A and D were assessed in 344 ESRD patients and 438 healthy controls, respectively. Haplogroup D was found to be risk maker for ESRD in young subjects (<30 years) with an OR of 2.274. Finally, intracellular and cell-free mtDNA copy numbers were evaluated with quantitative-PCR. The ESRD patients exhibited greater cell-free mtDNA contents than the healthy controls but less intracellular mtDNA. Haplogroup D exhibited a further increase in cell-free mtDNA content and a decrease in intracellular mtDNA content among the ESRDs patients. Our findings suggest that mtNDA haplogroup D may contributes to pathogenesis of early-onset ESRD through alterations of mtDNA copy numbers.
Collapse
Affiliation(s)
- Yuheng Zhang
- a Medical School of Nanjing University , Nanjing , Jiangsu Province , China.,b Jiangsu Key Laboratory of Molecular Medicine, Department of Medical Genetics , Nanjing University , Nanjing , Jiangsu Province , China
| | - Ying Zhao
- a Medical School of Nanjing University , Nanjing , Jiangsu Province , China.,b Jiangsu Key Laboratory of Molecular Medicine, Department of Medical Genetics , Nanjing University , Nanjing , Jiangsu Province , China
| | - Shuzhen Wen
- a Medical School of Nanjing University , Nanjing , Jiangsu Province , China.,b Jiangsu Key Laboratory of Molecular Medicine, Department of Medical Genetics , Nanjing University , Nanjing , Jiangsu Province , China
| | - Rengna Yan
- c Department of Endocrinology , Nanjing First Hospital, Nanjing Medical University , Nanjing , China
| | - Qinglan Yang
- a Medical School of Nanjing University , Nanjing , Jiangsu Province , China.,b Jiangsu Key Laboratory of Molecular Medicine, Department of Medical Genetics , Nanjing University , Nanjing , Jiangsu Province , China
| | - Huimei Chen
- a Medical School of Nanjing University , Nanjing , Jiangsu Province , China.,b Jiangsu Key Laboratory of Molecular Medicine, Department of Medical Genetics , Nanjing University , Nanjing , Jiangsu Province , China
| |
Collapse
|
31
|
Thaker K, Chwa M, Atilano SR, Coskun P, Cáceres-Del-Carpio J, Udar N, Boyer DS, Jazwinski SM, Miceli MV, Nesburn AB, Kuppermann BD, Kenney MC. Increased expression of ApoE and protection from amyloid-beta toxicity in transmitochondrial cybrids with haplogroup K mtDNA. Neurobiol Dis 2016; 93:64-77. [PMID: 27109188 DOI: 10.1016/j.nbd.2016.04.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Revised: 04/13/2016] [Accepted: 04/20/2016] [Indexed: 01/09/2023] Open
Abstract
Mitochondrial (mt) DNA haplogroups, defined by specific single nucleotide polymorphism (SNP) patterns, represent populations of diverse geographic origins and have been associated with increased risk or protection of many diseases. The H haplogroup is the most common European haplogroup while the K haplogroup is highly associated with the Ashkenazi Jewish population. Transmitochondrial cybrids (cell lines with identical nuclei, but mtDNA from either H (n=8) or K (n=8) subjects) were analyzed by the Seahorse flux analyzer, quantitative polymerase chain reaction (Q-PCR) and immunohistochemistry (IHC). Cybrids were treated with amyloid-β peptides and cell viabilities were measured. Other cybrids were demethylated with 5-aza-2'-deoxycytidine (5-aza-dC) and expression levels for APOE and NFkB2 were measured. Results show K cybrids have (a) significantly lower mtDNA copy numbers, (b) higher expression levels for MT-DNA encoded genes critical for oxidative phosphorylation, (c) lower Spare Respiratory Capacity, (d) increased expression of inhibitors of the complement pathway and important inflammasome-related genes; and (e) significantly higher levels of APOE transcription that were independent of methylation status. After exposure to amyloid-β1-42 peptides (active form), H haplogroup cybrids demonstrated decreased cell viability compared to those treated with amyloid-β42-1 (inactive form) (p<0.0001), while this was not observed in the K cybrids (p=0.2). K cybrids had significantly higher total global methylation levels and differences in expression levels for two acetylation genes and four methylation genes. Demethylation with 5-aza-dC altered expression levels for NFkB2, while APOE transcription patterns were unchanged. Our findings support the hypothesis that mtDNA-nuclear retrograde signaling may mediate expression levels of APOE, a key factor in many age-related diseases. Future studies will focus on identification of the mitochondrial-nuclear retrograde signaling mechanism(s) contributing to these mtDNA-mediated differences.
Collapse
Affiliation(s)
- Kunal Thaker
- Gavin Herbert Eye Institute, University of California Irvine, Irvine, CA, United States
| | - Marilyn Chwa
- Gavin Herbert Eye Institute, University of California Irvine, Irvine, CA, United States
| | - Shari R Atilano
- Gavin Herbert Eye Institute, University of California Irvine, Irvine, CA, United States
| | - Pinar Coskun
- Department of Neurobiology and Behavior, University of California Irvine, Irvine, CA, United States
| | | | - Nitin Udar
- Gavin Herbert Eye Institute, University of California Irvine, Irvine, CA, United States
| | - David S Boyer
- Retina-Vitreous Associates Medical Group, Beverly Hills, CA, United States
| | - S Michal Jazwinski
- Tulane Center for Aging and Department of Medicine, Tulane University, New Orleans, LA, United States
| | - Michael V Miceli
- Tulane Center for Aging and Department of Medicine, Tulane University, New Orleans, LA, United States
| | - Anthony B Nesburn
- Gavin Herbert Eye Institute, University of California Irvine, Irvine, CA, United States; Cedars-Sinai Medical Center, Los Angeles, CA, United States
| | - Baruch D Kuppermann
- Gavin Herbert Eye Institute, University of California Irvine, Irvine, CA, United States
| | - M Cristina Kenney
- Gavin Herbert Eye Institute, University of California Irvine, Irvine, CA, United States; Department of Pathology and Laboratory Medicine, University of California Irvine, Irvine, CA, United States.
| |
Collapse
|
32
|
Cherry C, Thompson B, Saptarshi N, Wu J, Hoh J. 2016: A 'Mitochondria' Odyssey. Trends Mol Med 2016; 22:391-403. [PMID: 27151392 DOI: 10.1016/j.molmed.2016.03.009] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Revised: 03/21/2016] [Accepted: 03/22/2016] [Indexed: 12/16/2022]
Abstract
The integration of the many roles of mitochondria in cellular function and the contribution of mitochondrial dysfunction to disease are major areas of research. Within this realm, the roles of mitochondria in immune defense, epigenetics, and stem cell (SC) development have recently come into the spotlight. With new understanding, mitochondria may bring together these seemingly unrelated fields, a crucial process in treatment and prevention for various diseases. In this review we describe novel findings in these three arenas, discussing the significance of the interplay between mitochondria and the cell nucleus in response to environmental cues. While we optimistically anticipate that further research in these areas can have a profound impact on disease management, we also bring forth some of the key questions and challenges that remain.
Collapse
Affiliation(s)
- Catherine Cherry
- School of Medicine, Departments of Environmental Health Science and Ophthalmology, Yale University, New Haven, CT, USA
| | - Brian Thompson
- School of Medicine, Departments of Environmental Health Science and Ophthalmology, Yale University, New Haven, CT, USA
| | - Neil Saptarshi
- School of Medicine, Departments of Environmental Health Science and Ophthalmology, Yale University, New Haven, CT, USA
| | - Jianyu Wu
- School of Medicine, Departments of Environmental Health Science and Ophthalmology, Yale University, New Haven, CT, USA
| | - Josephine Hoh
- School of Medicine, Departments of Environmental Health Science and Ophthalmology, Yale University, New Haven, CT, USA.
| |
Collapse
|
33
|
Atilano SR, Malik D, Chwa M, Cáceres-Del-Carpio J, Nesburn AB, Boyer DS, Kuppermann BD, Jazwinski SM, Miceli MV, Wallace DC, Udar N, Kenney MC. Mitochondrial DNA variants can mediate methylation status of inflammation, angiogenesis and signaling genes. Hum Mol Genet 2015; 24:4491-503. [PMID: 25964427 PMCID: PMC4512622 DOI: 10.1093/hmg/ddv173] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Accepted: 05/05/2015] [Indexed: 12/21/2022] Open
Abstract
Mitochondrial (mt) DNA can be classified into haplogroups representing different geographic and/or racial origins of populations. The H haplogroup is protective against age-related macular degeneration (AMD), while the J haplogroup is high risk for AMD. In the present study, we performed comparison analyses of human retinal cell cybrids, which possess identical nuclei, but mtDNA from subjects with either the H or J haplogroups, and demonstrate differences in total global methylation, and expression patterns for two genes related to acetylation and five genes related to methylation. Analyses revealed that untreated-H and -J cybrids have different expression levels for nuclear genes (CFH, EFEMP1, VEGFA and NFkB2). However, expression levels for these genes become equivalent after treatment with a methylation inhibitor, 5-aza-2'-deoxycytidine. Moreover, sequencing of the entire mtDNA suggests that differences in epigenetic status found in cybrids are likely due to single nucleotide polymorphisms (SNPs) within the haplogroup profiles rather than rare variants or private SNPs. In conclusion, our findings indicate that mtDNA variants can mediate methylation profiles and transcription for inflammation, angiogenesis and various signaling pathways, which are important in several common diseases.
Collapse
Affiliation(s)
| | | | | | | | - Anthony B Nesburn
- Gavin Herbert Eye Institute and Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - David S Boyer
- Retina-Vitreous Associates Medical Group, Beverly Hills, CA 90211, USA
| | | | - S Michal Jazwinski
- Tulane Center for Aging and Department of Medicine, Tulane University, New Orleans, LA 70118, USA and
| | - Michael V Miceli
- Tulane Center for Aging and Department of Medicine, Tulane University, New Orleans, LA 70118, USA and
| | - Douglas C Wallace
- Center of Mitochondrial and Epigenomic Medicine, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | | | - M Cristina Kenney
- Gavin Herbert Eye Institute and Department of Pathology and Laboratory Medicine, University of California Irvine, Irvine, CA 92697, USA,
| |
Collapse
|
34
|
Endophenotypes for Age-Related Macular Degeneration: Extending Our Reach into the Preclinical Stages of Disease. J Clin Med 2015; 3:1335-56. [PMID: 25568804 PMCID: PMC4284143 DOI: 10.3390/jcm3041335] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The key to reducing the individual and societal burden of age-related macular degeneration (AMD)-related vision loss, is to be able to initiate therapies that slow or halt the progression at a point that will yield the maximum benefit while minimizing personal risk and cost. There is a critical need to find clinical markers that, when combined with the specificity of genetic testing, will identify individuals at the earliest stages of AMD who would benefit from preventive therapies. These clinical markers are endophenotypes for AMD, present in those who are likely to develop AMD, as well as in those who have clinical evidence of AMD. Clinical characteristics associated with AMD may also be possible endophenotypes if they can be detected before or at the earliest stages of the condition, but we and others have shown that this may not always be valid. Several studies have suggested that dynamic changes in rhodopsin regeneration (dark adaptation kinetics and/or critical flicker fusion frequencies) may be more subtle indicators of AMD-associated early retinal dysfunction. One can test for the relevance of these measures using genetic risk profiles based on known genetic risk variants. These functional measures may improve the sensitivity and specificity of predictive models for AMD and may also serve to delineate clinical subtypes of AMD that may differ with respect to prognosis and treatment.
Collapse
|
35
|
Abstract
Age-related macular degeneration (AMD) is the leading cause of blindness among older adults in the developed world. Although the pathological mechanisms have not been definitively elucidated, evidence suggests a key role for mitochondrial (mt) dysfunction. The current study used our unique collection of human retinal samples graded for the donor's stage of AMD to address fundamental questions about mtDNA damage in the retina. To evaluate the distribution of mtDNA damage in the diseased retina, damage in the retinal pigment epithelium (RPE) and neural retina from individual donors were compared. To directly test a long-held belief that the macula is selectively damaged with AMD, RPE mtDNA damage was measured in the macula and peripheral sections from individual donors. Small segments of the entire mt genome were examined to determine whether specific regions are preferentially damaged. Our results show that mtDNA damage is limited to the RPE, equivalent mtDNA damage is found in the macular and peripheral RPE, and sites of damage are localized to regions of the mt genome that may impact mt function. These results provide a scientific basis for targeting the RPE mitochondria with therapies that protect and enhance mt function as a strategy for combating AMD.
Collapse
|
36
|
Restrepo NA, Mitchell SL, Goodloe RJ, Murdock DG, Haines JL, Crawford DC. Mitochondrial variation and the risk of age-related macular degeneration across diverse populations. PACIFIC SYMPOSIUM ON BIOCOMPUTING. PACIFIC SYMPOSIUM ON BIOCOMPUTING 2015:243-254. [PMID: 25592585 PMCID: PMC4299880] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Substantial progress has been made in identifying susceptibility variants for age-related macular degeneration (AMD). The majority of research to identify genetic variants associated with AMD has focused on nuclear genetic variation. While there is some evidence that mitochondrial genetic variation contributes to AMD susceptibility, to date, these studies have been limited to populations of European descent resulting in a lack of data in diverse populations. A major goal of the Epidemiologic Architecture for Genes Linked to Environment (EAGLE) study is to describe the underlying genetic architecture of common, complex diseases across diverse populations. This present study sought to determine if mitochondrial genetic variation influences risk of AMD across diverse populations. We performed a genetic association study to investigate the contribution of mitochondrial DNA variation to AMD risk. We accessed samples from the National Health and Nutrition Examination Surveys, a U.S population-based, cross-sectional survey collected without regard to health status. AMD cases and controls were selected from the Third NHANES and NHANES 2007-2008 datasets which include non-Hispanic whites, non-Hispanic blacks, and Mexican Americans. AMD cases were defined as those > 60 years of age with early/late AMD, as determined by fundus photography. Targeted genotyping was performed for 63 mitochondrial SNPs and participants were then classified into mitochondrial haplogroups. We used logistic regression assuming a dominant genetic model adjusting for age, sex, body mass index, and smoking status (ever vs. never). Regressions and meta-analyses were performed for individual SNPs and mitochondrial haplogroups J, T, and U. We identified five SNPs associated with AMD in Mexican Americans at p < 0.05, including three located in the control region (mt16111, mt16362, and mt16319), one in MT-RNR2 (mt1736), and one in MT-ND4 (mt12007). No mitochondrial variant or haplogroup was significantly associated in non-Hispanic blacks or non- Hispanic whites in the final meta-analysis. This study provides further evidence that mitochondrial variation plays a role in susceptibility to AMD and contributes to the knowledge of the genetic architecture of AMD in Mexican Americans.
Collapse
Affiliation(s)
- Nicole A Restrepo
- Center for Human Genetics Research, Vanderbilt University, 2215 Garland Avenue, 519 Light Hall, Nashville, TN 37232, USA.
| | | | | | | | | | | |
Collapse
|
37
|
Levin L, Blumberg A, Barshad G, Mishmar D. Mito-nuclear co-evolution: the positive and negative sides of functional ancient mutations. Front Genet 2014; 5:448. [PMID: 25566330 PMCID: PMC4274989 DOI: 10.3389/fgene.2014.00448] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Accepted: 12/08/2014] [Indexed: 12/31/2022] Open
Abstract
Most cell functions are carried out by interacting factors, thus underlying the functional importance of genetic interactions between genes, termed epistasis. Epistasis could be under strong selective pressures especially in conditions where the mutation rate of one of the interacting partners notably differs from the other. Accordingly, the order of magnitude higher mitochondrial DNA (mtDNA) mutation rate as compared to the nuclear DNA (nDNA) of all tested animals, should influence systems involving mitochondrial-nuclear (mito-nuclear) interactions. Such is the case of the energy producing oxidative phosphorylation (OXPHOS) and mitochondrial translational machineries which are comprised of factors encoded by both the mtDNA and the nDNA. Additionally, the mitochondrial RNA transcription and mtDNA replication systems are operated by nDNA-encoded proteins that bind mtDNA regulatory elements. As these systems are central to cell life there is strong selection toward mito-nuclear co-evolution to maintain their function. However, it is unclear whether (A) mito-nuclear co-evolution befalls only to retain mitochondrial functions during evolution or, also, (B) serves as an adaptive tool to adjust for the evolving energetic demands as species' complexity increases. As the first step to answer these questions we discuss evidence of both negative and adaptive (positive) selection acting on the mtDNA and nDNA-encoded genes and the effect of both types of selection on mito-nuclear interacting factors. Emphasis is given to the crucial role of recurrent ancient (nodal) mutations in such selective events. We apply this point-of-view to the three available types of mito-nuclear co-evolution: protein-protein (within the OXPHOS system), protein-RNA (mainly within the mitochondrial ribosome), and protein-DNA (at the mitochondrial replication and transcription machineries).
Collapse
Affiliation(s)
- Liron Levin
- Department of Life Sciences, Ben-Gurion University of the Negev Beersheba, Israel
| | - Amit Blumberg
- Department of Life Sciences, Ben-Gurion University of the Negev Beersheba, Israel
| | - Gilad Barshad
- Department of Life Sciences, Ben-Gurion University of the Negev Beersheba, Israel
| | - Dan Mishmar
- Department of Life Sciences, Ben-Gurion University of the Negev Beersheba, Israel
| |
Collapse
|
38
|
Estopinal CB, Chocron IM, Parks MB, Wade EA, Roberson RM, Burgess LG, Brantley MA, Samuels DC. Mitochondrial haplogroups are associated with severity of diabetic retinopathy. Invest Ophthalmol Vis Sci 2014; 55:5589-95. [PMID: 25118268 DOI: 10.1167/iovs.14-15149] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
PURPOSE To determine if specific mitochondrial haplogroups associate with nonproliferative diabetic retinopathy (NPDR) and proliferative diabetic retinopathy (PDR). METHODS Deidentified medical records for Caucasian patients with diabetic retinopathy (DR; 153 NPDR and 138 PDR) were obtained from BioVU, Vanderbilt University's electronic, deidentified DNA databank. An independent cohort of Caucasian patients with DR (44 NPDR and 57 PDR) from the Vanderbilt Eye Institute (VEI) was used for validation. We tested for an association between mitochondrial haplogroups and PDR among patients with DR. RESULTS In the BioVU cohort, PDR frequency among Caucasian DR patients differed significantly by mitochondrial haplogroup (P = 0.027). Replication in the VEI cohort confirmed this association (P = 0.0064). In the combined cohort, patients from the common haplogroup H were more likely to have PDR (odds ratio [OR] = 2.0 [95% confidence interval (CI) = 1.3-3.0], P = 0.0012), while patients from haplogroup Uk were less likely to have PDR (OR = 0.5 [95% CI = 0.3-0.8], P = 0.0049). In logistic regression analyses, the addition of diabetes duration, hemoglobin A1c (HgbA1c) levels, and hypertension had no effect on the associations of haplogroups H and Uk with PDR. CONCLUSIONS In this study, DR patients from mitochondrial haplogroup H were more likely to have PDR, while DR patients from haplogroup Uk were less likely to have PDR. The association was independent of the major clinical variables affecting PDR. The mitochondrial haplogroups were as strong a risk factor for PDR as were elevated HgbA1c levels.
Collapse
Affiliation(s)
- Christopher B Estopinal
- Vanderbilt Eye Institute, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - Isaac M Chocron
- Vanderbilt Eye Institute, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - Megan B Parks
- Vanderbilt Eye Institute, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - Emily A Wade
- Vanderbilt Eye Institute, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - Rachel M Roberson
- Vanderbilt Eye Institute, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - L Goodwin Burgess
- Vanderbilt Eye Institute, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - Milam A Brantley
- Vanderbilt Eye Institute, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - David C Samuels
- Center for Human Genetics Research and Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| |
Collapse
|
39
|
Anand A, Sharma K, Chen W, Sharma NK. Using current data to define new approach in age related macular degeneration: need to accelerate translational research. Curr Genomics 2014; 15:266-77. [PMID: 25132797 PMCID: PMC4133950 DOI: 10.2174/1389202915666140516204512] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2014] [Revised: 05/16/2014] [Accepted: 05/16/2014] [Indexed: 11/22/2022] Open
Abstract
Age related macular degeneration (AMD) is one of the major retinal degenerative disease of ageing whose complex genetic basis remains undeciphered. The involvement of various other factors like mitochondrial genes, cytoskeletal proteins and the role of epigenetics has been described in this review. Several population based AMD genetic studies have been carried out worldwide. Despite the increased publication of reports, clinical translation still eludes this davastating disease. We suggest models to address roadblocks in clinical translation hoping that these would be beneficial to drive AMD research towards innovative biomarkers and therapeutics Therefore, addressing the need large autopsy studies and combining it with efficient use of bioinformatic tools, statistical modeling and probing SNP-biomarker association are key to time bound resolution of this disease.
Collapse
Affiliation(s)
- Akshay Anand
- Neuroscience Research Lab, Department of Neurology, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - Kaushal Sharma
- Neuroscience Research Lab, Department of Neurology, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - Wei Chen
- Division of Pulmonary Medicine, Allergy and Immunology, University of Pittsburgh, Pittsburgh, PA 15224 USA
| | - Neel Kamal Sharma
- Neurobiology-Neurodegeneration and Repair Laboratory, National Eye Institute, Bethesda, USA
| |
Collapse
|
40
|
Kenney MC, Chwa M, Atilano SR, Falatoonzadeh P, Ramirez C, Malik D, Tarek M, Cáceres-del-Carpio J, Nesburn AB, Boyer DS, Kuppermann BD, Vawter M, Jazwinski SM, Miceli M, Wallace DC, Udar N. Inherited mitochondrial DNA variants can affect complement, inflammation and apoptosis pathways: insights into mitochondrial-nuclear interactions. Hum Mol Genet 2014; 23:3537-51. [PMID: 24584571 PMCID: PMC4049308 DOI: 10.1093/hmg/ddu065] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2013] [Revised: 02/03/2014] [Accepted: 02/10/2014] [Indexed: 12/21/2022] Open
Abstract
Age-related macular degeneration (AMD) is the leading cause of vision loss in developed countries. While linked to genetic polymorphisms in the complement pathway, there are many individuals with high risk alleles that do not develop AMD, suggesting that other 'modifiers' may be involved. Mitochondrial (mt) haplogroups, defined by accumulations of specific mtDNA single nucleotide polymorphisms (SNPs) which represent population origins, may be one such modifier. J haplogroup has been associated with high risk for AMD while the H haplogroup is protective. It has been difficult to assign biological consequences for haplogroups so we created human ARPE-19 cybrids (cytoplasmic hybrids), which have identical nuclei but mitochondria of either J or H haplogroups, to investigate their effects upon bioenergetics and molecular pathways. J cybrids have altered bioenergetic profiles compared with H cybrids. Q-PCR analyses show significantly lower expression levels for seven respiratory complex genes encoded by mtDNA. J and H cybrids have significantly altered expression of eight nuclear genes of the alternative complement, inflammation and apoptosis pathways. Sequencing of the entire mtDNA was carried out for all the cybrids to identify haplogroup and non-haplogroup defining SNPs. mtDNA can mediate cellular bioenergetics and expression levels of nuclear genes related to complement, inflammation and apoptosis. Sequencing data suggest that observed effects are not due to rare mtDNA variants but rather the combination of SNPs representing the J versus H haplogroups. These findings represent a paradigm shift in our concepts of mt-nuclear interactions.
Collapse
Affiliation(s)
- M Cristina Kenney
- Gavin Herbert Eye Institute, Department of Pathology and Laboratory Medicine,
| | | | | | | | | | | | | | | | - Anthony B Nesburn
- Gavin Herbert Eye Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - David S Boyer
- Retina-Vitreous Associates Medical Group, Beverly Hills, CA, USA
| | | | - Marquis Vawter
- Functional Genomics Laboratory, Department of Psychiatry and Human Behavior, University of California Irvine, Irvine, CA, USA
| | | | - Michael Miceli
- Tulane Center for Aging, Tulane University, New Orleans, LA, USA
| | - Douglas C Wallace
- Children's Hospital of Philadelphia, Center for Mitochondrial and Epigenomic Medicine, Philadelphia, PA, USA
| | | |
Collapse
|
41
|
Retinal pigment epithelial cells undergoing mitotic catastrophe are vulnerable to autophagy inhibition. Cell Death Dis 2014; 5:e1303. [PMID: 24967965 PMCID: PMC4611738 DOI: 10.1038/cddis.2014.266] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Revised: 03/20/2014] [Accepted: 05/20/2014] [Indexed: 12/03/2022]
Abstract
The increased mitochondrial DNA damage leads to altered functional capacities of retinal pigment epithelial (RPE) cells. A previous study showed the increased autophagy in RPE cells caused by low concentrations of rotenone, a selective inhibitor of mitochondrial complex I. However, the mechanism by which autophagy regulates RPE cell death is still unclear. In the present study, we examined the mechanism underlying the regulation of RPE cell death through the inhibition of mitochondrial complex I. We report herein that rotenone induced mitotic catastrophe (MC) in RPE cells. We further observed an increased level of autophagy in the RPE cells undergoing MC (RPE-MC cells). Importantly, autophagy inhibition induced nonapoptotic cell death in RPE-MC cells. These findings indicate that autophagy has a pivotal role in the survival of RPE-MC cells. We next observed PINK1 accumulation in the mitochondrial membrane and parkin translocation into the mitochondria from the cytosol in the rotenone-treated RPE-MC cells, which indicates that increased mitophagy accompanies MC in ARPE-19 cells. Noticeably, the mitophagy also contributed to the cytoprotection of RPE-MC cells. Although there might be a significant gap in the roles of autophagy and mitophagy in the RPE cells in vivo, our in vitro study suggests that autophagy and mitophagy presumably prevent the RPE-MC cells from plunging into cell death, resulting in the prevention of RPE cell loss.
Collapse
|
42
|
Malik D, Hsu T, Falatoonzadeh P, Cáceres-del-Carpio J, Tarek M, Chwa M, Atilano SR, Ramirez C, Nesburn AB, Boyer DS, Kuppermann BD, Jazwinski SM, Miceli MV, Wallace DC, Udar N, Kenney MC. Human retinal transmitochondrial cybrids with J or H mtDNA haplogroups respond differently to ultraviolet radiation: implications for retinal diseases. PLoS One 2014; 9:e99003. [PMID: 24919117 PMCID: PMC4053329 DOI: 10.1371/journal.pone.0099003] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2013] [Accepted: 05/08/2014] [Indexed: 01/04/2023] Open
Abstract
Background It has been recognized that cells do not respond equally to ultraviolet (UV) radiation but it is not clear whether this is due to genetic, biochemical or structural differences of the cells. We have a novel cybrid (cytoplasmic hybrids) model that allows us to analyze the contribution of mitochondrial DNA (mtDNA) to cellular response after exposure to sub-lethal dose of UV. mtDNA can be classified into haplogroups as defined by accumulations of specific single nucleotide polymorphisms (SNPs). Recent studies have shown that J haplogroup is high risk for age-related macular degeneration while the H haplogroup is protective. This study investigates gene expression responses in J cybrids versus H cybrids after exposure to sub-lethal doses of UV-radiation. Methodology/Principal Findings Cybrids were created by fusing platelets isolated from subjects with either H (n = 3) or J (n = 3) haplogroups with mitochondria-free (Rho0) ARPE-19 cells. The H and J cybrids were cultured for 24 hours, treated with 10 mJ of UV-radiation and cultured for an additional 120 hours. Untreated and treated cybrids were analyzed for growth rates and gene expression profiles. The UV-treated and untreated J cybrids had higher growth rates compared to H cybrids. Before treatment, J cybrids showed lower expression levels for CFH, CD55, IL-33, TGF-A, EFEMP-1, RARA, BCL2L13 and BBC3. At 120 hours after UV-treatment, the J cybrids had decreased CFH, RARA and BBC3 levels but increased CD55, IL-33 and EFEMP-1 compared to UV-treated H cybrids. Conclusion/Significance In cells with identical nuclei, the cellular response to sub-lethal UV-radiation is mediated in part by the mtDNA haplogroup. This supports the hypothesis that differences in growth rates and expression levels of complement, inflammation and apoptosis genes may result from population-specific, hereditary SNP variations in mtDNA. Therefore, when analyzing UV-induced damage in tissues, the mtDNA haplogroup background may be important to consider.
Collapse
Affiliation(s)
- Deepika Malik
- Gavin Herbert Eye Institute, University California Irvine, Irvine, California, United States of America
| | - Tiffany Hsu
- Gavin Herbert Eye Institute, University California Irvine, Irvine, California, United States of America
| | - Payam Falatoonzadeh
- Gavin Herbert Eye Institute, University California Irvine, Irvine, California, United States of America
| | - Javier Cáceres-del-Carpio
- Gavin Herbert Eye Institute, University California Irvine, Irvine, California, United States of America
| | - Mohamed Tarek
- Gavin Herbert Eye Institute, University California Irvine, Irvine, California, United States of America
- Department of Ophthalmology, El-Minya University, El-Minya, Egypt
| | - Marilyn Chwa
- Gavin Herbert Eye Institute, University California Irvine, Irvine, California, United States of America
| | - Shari R. Atilano
- Gavin Herbert Eye Institute, University California Irvine, Irvine, California, United States of America
| | - Claudio Ramirez
- Gavin Herbert Eye Institute, University California Irvine, Irvine, California, United States of America
| | - Anthony B. Nesburn
- Gavin Herbert Eye Institute, University California Irvine, Irvine, California, United States of America
- Cedars-Sinai Medical Center, Los Angeles, California, United States of America
| | - David S. Boyer
- Retina-Vitreous Associates Medical Group; Beverly Hills, California, United States of America
| | - Baruch D. Kuppermann
- Gavin Herbert Eye Institute, University California Irvine, Irvine, California, United States of America
| | - S. Michal Jazwinski
- Tulane Center for Aging, Tulane University, New Orleans, Louisiana, United States of America
| | - Michael V. Miceli
- Tulane Center for Aging, Tulane University, New Orleans, Louisiana, United States of America
| | - Douglas C. Wallace
- Center for Mitochondrial and Epigenomic Medicine, Children’s Hospital of Philadelphia and Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Nitin Udar
- Gavin Herbert Eye Institute, University California Irvine, Irvine, California, United States of America
| | - M. Cristina Kenney
- Gavin Herbert Eye Institute, University California Irvine, Irvine, California, United States of America
- Department of Pathology and Laboratory Medicine, University California Irvine, Irvine, California, United States of America
- * E-mail:
| |
Collapse
|
43
|
Fritsche LG, Fariss RN, Stambolian D, Abecasis GR, Curcio CA, Swaroop A. Age-related macular degeneration: genetics and biology coming together. Annu Rev Genomics Hum Genet 2014; 15:151-71. [PMID: 24773320 DOI: 10.1146/annurev-genom-090413-025610] [Citation(s) in RCA: 340] [Impact Index Per Article: 34.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Genetic and genomic studies have enhanced our understanding of complex neurodegenerative diseases that exert a devastating impact on individuals and society. One such disease, age-related macular degeneration (AMD), is a major cause of progressive and debilitating visual impairment. Since the pioneering discovery in 2005 of complement factor H (CFH) as a major AMD susceptibility gene, extensive investigations have confirmed 19 additional genetic risk loci, and more are anticipated. In addition to common variants identified by now-conventional genome-wide association studies, targeted genomic sequencing and exome-chip analyses are uncovering rare variant alleles of high impact. Here, we provide a critical review of the ongoing genetic studies and of common and rare risk variants at a total of 20 susceptibility loci, which together explain 40-60% of the disease heritability but provide limited power for diagnostic testing of disease risk. Identification of these susceptibility loci has begun to untangle the complex biological pathways underlying AMD pathophysiology, pointing to new testable paradigms for treatment.
Collapse
Affiliation(s)
- Lars G Fritsche
- Center for Statistical Genetics, Department of Biostatistics, School of Public Health, University of Michigan, Ann Arbor, Michigan 48109; ,
| | | | | | | | | | | |
Collapse
|
44
|
Gene therapy for mitochondrial diseases: Leber Hereditary Optic Neuropathy as the first candidate for a clinical trial. C R Biol 2014; 337:193-206. [PMID: 24702846 DOI: 10.1016/j.crvi.2013.11.011] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2013] [Accepted: 11/28/2013] [Indexed: 12/30/2022]
Abstract
Mitochondrial disorders cannot be ignored anymore in most medical disciplines; indeed their minimum estimated prevalence is superior to 1 in 5000 births. Despite the progress made in the last 25 years on the identification of gene mutations causing mitochondrial pathologies, only slow progress was made towards their effective treatments. Ocular involvement is a frequent feature in mitochondrial diseases and corresponds to severe and irreversible visual handicap due to retinal neuron loss and optic atrophy. Interestingly, three clinical trials for Leber Congenital Amaurosis due to RPE65 mutations are ongoing since 2007. Overall, the feasibility and safety of ocular Adeno-Associated Virus delivery in adult and younger patients and consistent visual function improvements have been demonstrated. The success of gene-replacement therapy for RPE65 opens the way for the development of similar approaches for a broad range of eye disorders, including those with mitochondrial etiology such as Leber Hereditary Optic Neuropathy (LHON).
Collapse
|
45
|
Dhillon VS, Fenech M. Mutations that affect mitochondrial functions and their association with neurodegenerative diseases. MUTATION RESEARCH-REVIEWS IN MUTATION RESEARCH 2013; 759:1-13. [PMID: 24055911 DOI: 10.1016/j.mrrev.2013.09.001] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2013] [Revised: 09/05/2013] [Accepted: 09/08/2013] [Indexed: 12/20/2022]
Abstract
Mitochondria are essential for mammalian and human cell function as they generate ATP via aerobic respiration. The proteins required in the electron transport chain are mainly encoded by the circular mitochondrial genome but other essential mitochondrial proteins such as DNA repair genes, are coded in the nuclear genome and require transport into the mitochondria. In this review we summarize current knowledge on the association of point mutations and deletions in the mitochondrial genome that are detrimental to mitochondrial function and are associated with accelerated ageing and neurological disorders including Alzheimer's, Parkinson's, Huntington's and Amyotrophic lateral sclerosis (ALS). Mutations in the nuclear encoded genes that disrupt mitochondrial functions are also discussed. It is evident that a greater understanding of the causes of mutations that adversely affect mitochondrial metabolism is required to develop preventive measures against accelerated ageing and neurological disorders caused by mitochondrial dysfunction.
Collapse
Affiliation(s)
- Varinderpal S Dhillon
- Preventative-Health Flagship, Gate 13, Kintore Avenue, Adelaide, SA 5000, Australia; CSIRO Animal, Food and Health Sciences, Gate 13, Kintore Avenue, Adelaide, SA 5000, Australia.
| | - Michael Fenech
- Preventative-Health Flagship, Gate 13, Kintore Avenue, Adelaide, SA 5000, Australia; CSIRO Animal, Food and Health Sciences, Gate 13, Kintore Avenue, Adelaide, SA 5000, Australia
| |
Collapse
|
46
|
Shadrach KG, Rayborn ME, Hollyfield JG, Bonilha VL. DJ-1-dependent regulation of oxidative stress in the retinal pigment epithelium (RPE). PLoS One 2013; 8:e67983. [PMID: 23844142 PMCID: PMC3699467 DOI: 10.1371/journal.pone.0067983] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2013] [Accepted: 05/23/2013] [Indexed: 01/16/2023] Open
Abstract
BACKGROUND DJ-1 is found in many tissues, including the brain, where it has been extensively studied due to its association with Parkinson's disease. DJ-1 functions as a redox-sensitive molecular chaperone and transcription regulator that robustly protects cells from oxidative stress. METHODOLOGY Retinal pigment epithelial (RPE) cultures were treated with H2O2 for various times followed by biochemical and immunohistological analysis. Cells were transfected with adenoviruses carrying the full-length human DJ-1 cDNA and a mutant construct, which has the cysteine residues at amino acid 46, 53 and 106 mutated to serine (C to S) prior to stress experiments. DJ-1 localization, levels of expression and reactive oxygen species (ROS) generation were also analyzed in cells expressing exogenous DJ-1 under baseline and oxidative stress conditions. The presence of DJ-1 and oxidized DJ-1 was evaluated in human RPE total lysates. The distribution of DJ-1 was assessed in AMD and non-AMD cryosectionss and in isolated human Bruch's membrane (BM)/choroid from AMD eyes. PRINCIPAL FINDINGS DJ-1 in RPE cells under baseline conditions, displays a diffuse cytoplasmic and nuclear staining. After oxidative challenge, more DJ-1 was associated with mitochondria. Increasing concentrations of H2O2 resulted in a dose-dependent increase in DJ-1. Overexpression of DJ-1 but not the C to S mutant prior to exposure to oxidative stress led to significant decrease in the generation of ROS. DJ-1 and oxDJ-1 intensity of immunoreactivity was significantly higher in the RPE lysates from AMD eyes. More DJ-1 was localized to RPE cells from AMD donors with geographic atrophy and DJ-1 was also present in isolated human BM/choroid from AMD eyes. CONCLUSIONS/SIGNIFICANCE DJ-1 regulates RPE responses to oxidative stress. Most importantly, increased DJ-1 expression prior to oxidative stress leads to decreased generation of ROS, which will be relevant for future studies of AMD since oxidative stress is a known factor affecting this disease.
Collapse
Affiliation(s)
- Karen G. Shadrach
- Department of Ophthalmic Research, The Cole Eye Institute, Cleveland Clinic Lerner College of Medicine, Cleveland, Ohio, United States of America
| | - Mary E. Rayborn
- Department of Ophthalmic Research, The Cole Eye Institute, Cleveland Clinic Lerner College of Medicine, Cleveland, Ohio, United States of America
| | - Joe G. Hollyfield
- Department of Ophthalmic Research, The Cole Eye Institute, Cleveland Clinic Lerner College of Medicine, Cleveland, Ohio, United States of America
| | - Vera L. Bonilha
- Department of Ophthalmic Research, The Cole Eye Institute, Cleveland Clinic Lerner College of Medicine, Cleveland, Ohio, United States of America
- * E-mail:
| |
Collapse
|
47
|
Tilleul J, Richard F, Puche N, Zerbib J, Leveziel N, Sahel JA, Cohen SY, Korobelnik JF, Feingold J, Munnich A, Kaplan J, Rozet JM, Souied EH. Genetic association study of mitochondrial polymorphisms in neovascular age-related macular degeneration. Mol Vis 2013; 19:1132-40. [PMID: 23734082 PMCID: PMC3669531] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2012] [Accepted: 05/27/2013] [Indexed: 11/29/2022] Open
Abstract
PURPOSE Age-related macular degeneration (AMD) is a multifactorial disease involving genetic and environmental factors. Most of the genetic factors identified so far involve the nuclear genome. Recently, two studies in North America and Australia reported an association between advanced AMD and the mitochondrial T2 haplogroup. Our purpose was to assess this association in a large French population. METHODS This case control study included 1,224 patients with neovascular AMD and 559 controls with normal fundus. Mitochondrial DNA polymorphisms at and around nucleotides 4917, 11,812, and 14,233 were determined using PCR amplification and direct sequencing of mitochondrial DNA. RESULTS No association was found between the mitochondrial T2 haplogroup and neovascular AMD in the French population: 94/1,152 patients with neovascular AMD had the T2 haplogroup (8.2%) versus 34/482 controls (7.1%; odds ratio=0.9 [0.5-1.5], p=0.66). CONCLUSIONS An association between AMD and the T2 haplogroup, previously described in North American and Australian populations, was not confirmed in a large French population.
Collapse
Affiliation(s)
- Julien Tilleul
- Department of Ophthalmology, Hôpital Intercommunal de Creteil, University of Paris Est Creteil, France,Department of Genetics, INSERM U781, Hôpital Necker Enfants Malades, University of Paris Descartes, Paris, France
| | - Florence Richard
- University Lille Nord of France, INSERM, UMR744, Institut Pasteur of Lille, Lille, France
| | - Nathalie Puche
- Department of Ophthalmology, Hôpital Intercommunal de Creteil, University of Paris Est Creteil, France
| | - Jennyfer Zerbib
- Department of Ophthalmology, Hôpital Intercommunal de Creteil, University of Paris Est Creteil, France
| | - Nicolas Leveziel
- Department of Ophthalmology, Hôpital Intercommunal de Creteil, University of Paris Est Creteil, France
| | - Jose Alain Sahel
- Department of Ophthalmology, Institut de la Vision, Inserm, Pierre et Marie Curie University, Paris, France
| | | | - Jean-Francois Korobelnik
- Ophthalmology, Hôpital Pellegrin CHU de Bordeaux, Université Bordeaux 2, INSERM U897, Bordeaux, France
| | - Josue Feingold
- Department of Genetics, INSERM U781, Hôpital Necker Enfants Malades, University of Paris Descartes, Paris, France
| | - Arnold Munnich
- Department of Genetics, INSERM U781, Hôpital Necker Enfants Malades, University of Paris Descartes, Paris, France
| | - Josseline Kaplan
- Department of Genetics, INSERM U781, Hôpital Necker Enfants Malades, University of Paris Descartes, Paris, France
| | - Jean-Michel Rozet
- Department of Genetics, INSERM U781, Hôpital Necker Enfants Malades, University of Paris Descartes, Paris, France
| | - Eric H. Souied
- Department of Ophthalmology, Hôpital Intercommunal de Creteil, University of Paris Est Creteil, France
| |
Collapse
|
48
|
Melville H, Carpiniello M, Hollis K, Staffaroni A, Golestaneh N. Stem cells: a new paradigm for disease modeling and developing therapies for age-related macular degeneration. J Transl Med 2013; 11:53. [PMID: 23452406 PMCID: PMC3599723 DOI: 10.1186/1479-5876-11-53] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2012] [Accepted: 02/19/2013] [Indexed: 02/06/2023] Open
Abstract
Age-related macular degeneration (AMD) is the leading cause of blindness in people over age 55 in the U.S. and the developed world. This condition leads to the progressive impairment of central visual acuity. There are significant limitations in the understanding of disease progression in AMD as well as a lack of effective methods of treatment. Lately, there has been considerable enthusiasm for application of stem cell biology for both disease modeling and therapeutic application. Human embryonic stem cells and induced pluripotent stem cells (iPSCs) have been used in cell culture assays and in vivo animal models. Recently a clinical trial was approved by FDA to investigate the safety and efficacy of the human embryonic stem cell-derived retinal pigment epithelium (RPE) transplantation in sub-retinal space of patients with dry AMD These studies suggest that stem cell research may provide both insight regarding disease development and progression, as well as direction for therapeutic innovation for the millions of patients afflicted with AMD.
Collapse
Affiliation(s)
- Heather Melville
- Georgetown University School of Medicine, 3900 Reservoir Rd, Washington, DC 20057, USA
| | - Matthew Carpiniello
- Georgetown University School of Medicine, 3900 Reservoir Rd, Washington, DC 20057, USA
| | - Kia Hollis
- Georgetown University School of Medicine, 3900 Reservoir Rd, Washington, DC 20057, USA
| | - Andrew Staffaroni
- Georgetown University School of Medicine, 3900 Reservoir Rd, Washington, DC 20057, USA
| | - Nady Golestaneh
- Georgetown University School of Medicine, 3900 Reservoir Rd, Washington, DC 20057, USA
- Department of Ophthalmology, Georgetown University, School of Medicine, 3900 Reservoir Rd, Washington, DC 20057, USA
- Department of Neurology, Georgetown University, School of Medicine, 3900 Reservoir Rd, Washington, DC 20057, USA
- Department of Biochemistry and Molecular & Cellular Biology, Georgetown University, School of Medicine, 3900 Reservoir Rd, Washington, DC 20057, USA
| |
Collapse
|
49
|
The eye as a model of ageing in translational research--molecular, epigenetic and clinical aspects. Ageing Res Rev 2013; 12:490-508. [PMID: 23274270 DOI: 10.1016/j.arr.2012.11.002] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2012] [Revised: 11/16/2012] [Accepted: 11/19/2012] [Indexed: 12/13/2022]
Abstract
The eye and visual system are valuable in many areas of translational research such as stem cell therapy, transplantation research and gene therapy. Changes in many ocular tissues can be measured directly, easily and objectively in vivo (e.g. lens transparency; retinal blood vessel calibre; corneal endothelial cell counts) and so the eye may also be a uniquely useful site as a model of ageing. This review details cellular, molecular and epigenetic mechanisms related to ageing within the eye, and describes ocular parameters that can be directly measured clinically and which might be of value in ageing research as the translational "window to the rest of the body". The eye is likely to provide a valuable model for validating biomarkers of ageing at molecular, epigenetic, cellular and clinical levels. A research agenda to definitively establish the relationship between biomarkers of ageing and ocular parameters is proposed.
Collapse
|
50
|
Kenney MC, Chwa M, Atilano SR, Pavlis JM, Falatoonzadeh P, Ramirez C, Malik D, Hsu T, Woo G, Soe K, Nesburn AB, Boyer DS, Kuppermann BD, Jazwinski SM, Miceli MV, Wallace DC, Udar N. Mitochondrial DNA variants mediate energy production and expression levels for CFH, C3 and EFEMP1 genes: implications for age-related macular degeneration. PLoS One 2013; 8:e54339. [PMID: 23365660 PMCID: PMC3554762 DOI: 10.1371/journal.pone.0054339] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2012] [Accepted: 12/10/2012] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Mitochondrial dysfunction is associated with the development and progression of age-related macular degeneration (AMD). Recent studies using populations from the United States and Australia have demonstrated that AMD is associated with mitochondrial (mt) DNA haplogroups (as defined by combinations of mtDNA polymorphisms) that represent Northern European Caucasians. The aim of this study was to use the cytoplasmic hybrid (cybrid) model to investigate the molecular and biological functional consequences that occur when comparing the mtDNA H haplogroup (protective for AMD) versus J haplogroup (high risk for AMD). METHODOLOGY/PRINCIPAL FINDINGS Cybrids were created by introducing mitochondria from individuals with either H or J haplogroups into a human retinal epithelial cell line (ARPE-19) that was devoid of mitochondrial DNA (Rho0). In cybrid lines, all of the cells carry the same nuclear genes but vary in mtDNA content. The J cybrids had significantly lower levels of ATP and reactive oxygen/nitrogen species production, but increased lactate levels and rates of growth. Q-PCR analyses showed J cybrids had decreased expressions for CFH, C3, and EFEMP1 genes, high risk genes for AMD, and higher expression for MYO7A, a gene associated with retinal degeneration in Usher type IB syndrome. The H and J cybrids also have comparatively altered expression of nuclear genes involved in pathways for cell signaling, inflammation, and metabolism. CONCLUSION/SIGNIFICANCE Our findings demonstrate that mtDNA haplogroup variants mediate not only energy production and cell growth, but also cell signaling for major molecular pathways. These data support the hypothesis that mtDNA variants play important roles in numerous cellular functions and disease processes, including AMD.
Collapse
Affiliation(s)
- M Cristina Kenney
- Gavin Herbert Eye Institute, University of California Irvine, Irvine, California, United States of America.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|