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Riley-Gillis B, Huh H, Shen J, den Hollander AI. Genetic and molecular biomarkers for geographic atrophy. Acta Ophthalmol 2023; 101:869-880. [PMID: 37933607 DOI: 10.1111/aos.15803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Revised: 10/14/2023] [Accepted: 10/14/2023] [Indexed: 11/08/2023]
Abstract
Geographic atrophy (GA) is characterized by atrophy of the retina, retinal pigment epithelium and choriocapillaris, causing a gradual loss of vision over time. Treatment options to prevent initiation or progression of GA are limited; two recently FDA-approved inhibitors of the complement system (pegcetacoplan, avacincaptad pegol) showed a modest decrease in GA lesion growth in phase 3 clinical trials. Exploration of genetic and molecular biomarkers in GA plays a critical role in our battle against this blinding disease to improve early disease detection, to find more effective therapies, and to provide personalized care to patients. In this review, we provide a comprehensive overview of the current literature investigating genetic and molecular biomarkers for GA. Genetic studies identified multiple genes and variants that play a role in progression to GA and GA lesion growth, involving pathways such as complement activation, extracellular matrix interaction and lipid metabolism. The number of published studies assessing molecular biomarkers for GA initiation and progression in ocular matrices is limited. Several studies evaluated molecular biomarkers in the systemic circulation, showing higher levels of complement activation and a causal role of lipid subfractions in GA. Larger, well-powered studies are needed to identify novel and validate existing biomarkers, and to investigate the potential of combining genetic and molecular markers with imaging techniques for more accurate diagnosis and monitoring of GA. The development of personalized medicine approaches based on individual genetic and molecular profiles could hold promise for more effective and targeted treatments for this devastating disease.
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Affiliation(s)
| | - Hannah Huh
- AbbVie, Local Delivery Translational Sciences, Irvine, California, USA
| | - Jie Shen
- AbbVie, Local Delivery Translational Sciences, Irvine, California, USA
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2
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Lenin RR, Koh YH, Zhang Z, Yeo YZ, Parikh BH, Seah I, Wong W, Su X. Dysfunctional Autophagy, Proteostasis, and Mitochondria as a Prelude to Age-Related Macular Degeneration. Int J Mol Sci 2023; 24:ijms24108763. [PMID: 37240109 DOI: 10.3390/ijms24108763] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 05/05/2023] [Accepted: 05/06/2023] [Indexed: 05/28/2023] Open
Abstract
Retinal pigment epithelial (RPE) cell dysfunction is a key driving force of AMD. RPE cells form a metabolic interface between photoreceptors and choriocapillaris, performing essential functions for retinal homeostasis. Through their multiple functions, RPE cells are constantly exposed to oxidative stress, which leads to the accumulation of damaged proteins, lipids, nucleic acids, and cellular organelles, including mitochondria. As miniature chemical engines of the cell, self-replicating mitochondria are heavily implicated in the aging process through a variety of mechanisms. In the eye, mitochondrial dysfunction is strongly associated with several diseases, including age-related macular degeneration (AMD), which is a leading cause of irreversible vision loss in millions of people globally. Aged mitochondria exhibit decreased rates of oxidative phosphorylation, increased reactive oxygen species (ROS) generation, and increased numbers of mitochondrial DNA mutations. Mitochondrial bioenergetics and autophagy decline during aging because of insufficient free radical scavenger systems, the impairment of DNA repair mechanisms, and reductions in mitochondrial turnover. Recent research has uncovered a much more complex role of mitochondrial function and cytosolic protein translation and proteostasis in AMD pathogenesis. The coupling of autophagy and mitochondrial apoptosis modulates the proteostasis and aging processes. This review aims to summarise and provide a perspective on (i) the current evidence of autophagy, proteostasis, and mitochondrial dysfunction in dry AMD; (ii) current in vitro and in vivo disease models relevant to assessing mitochondrial dysfunction in AMD, and their utility in drug screening; and (iii) ongoing clinical trials targeting mitochondrial dysfunction for AMD therapeutics.
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Affiliation(s)
- Raji Rajesh Lenin
- Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore (NUS), 1E Kent Ridge Road, NUHS Tower Block Level 7, Singapore 119228, Singapore
- Department of Medical Research, SRM Institute of Science and Technology, Kattankulathur 603203, Tamil Nadu, India
| | - Yi Hui Koh
- Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore (NUS), 1E Kent Ridge Road, NUHS Tower Block Level 7, Singapore 119228, Singapore
| | - Zheting Zhang
- Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore (NUS), 1E Kent Ridge Road, NUHS Tower Block Level 7, Singapore 119228, Singapore
- Lee Kong Chian School of Medicine, Nanyang Technological University (NTU), 11 Mandalay Road, Experimental Medicine Building, Singapore 308232, Singapore
| | - Yan Zhuang Yeo
- Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology, and Research (A*STAR), 61 Biopolis Drive, Proteos, Singapore 138673, Singapore
| | - Bhav Harshad Parikh
- Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology, and Research (A*STAR), 61 Biopolis Drive, Proteos, Singapore 138673, Singapore
| | - Ivan Seah
- Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore (NUS), 1E Kent Ridge Road, NUHS Tower Block Level 7, Singapore 119228, Singapore
| | - Wendy Wong
- Department of Ophthalmology, National University Hospital (NUH), 1E Kent Ridge Road, NUHS Tower Block Level 7, Singapore 119228, Singapore
| | - Xinyi Su
- Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore (NUS), 1E Kent Ridge Road, NUHS Tower Block Level 7, Singapore 119228, Singapore
- Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology, and Research (A*STAR), 61 Biopolis Drive, Proteos, Singapore 138673, Singapore
- Department of Ophthalmology, National University Hospital (NUH), 1E Kent Ridge Road, NUHS Tower Block Level 7, Singapore 119228, Singapore
- Singapore Eye Research Institute (SERI), The Academia, 20 College Road, Level 6 Discovery Tower, Singapore 169856, Singapore
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3
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Blasiak J, Sobczuk P, Pawlowska E, Kaarniranta K. Interplay between aging and other factors of the pathogenesis of age-related macular degeneration. Ageing Res Rev 2022; 81:101735. [PMID: 36113764 DOI: 10.1016/j.arr.2022.101735] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Revised: 08/03/2022] [Accepted: 09/12/2022] [Indexed: 01/31/2023]
Abstract
Age-related macular degeneration (AMD) is a complex eye disease with the retina as the target tissue and aging as per definition the most serious risk factor. However, the retina contains over 60 kinds of cells that form different structures, including the neuroretina and retinal pigment epithelium (RPE) which can age at different rates. Other established or putative AMD risk factors can differentially affect the neuroretina and RPE and can differently interplay with aging of these structures. The occurrence of β-amyloid plaques and increased levels of cholesterol in AMD retinas suggest that AMD may be a syndrome of accelerated brain aging. Therefore, the question about the real meaning of age in AMD is justified. In this review we present and update information on how aging may interplay with some aspects of AMD pathogenesis, such as oxidative stress, amyloid beta formation, circadian rhythm, metabolic aging and cellular senescence. Also, we show how this interplay can be specific for photoreceptors, microglia cells and RPE cells as well as in Bruch's membrane and the choroid. Therefore, the process of aging may differentially affect different retinal structures. As an accurate quantification of biological aging is important for risk stratification and early intervention for age-related diseases, the determination how photoreceptors, microglial and RPE cells age in AMD may be helpful for a precise diagnosis and treatment of this largely untreatable disease.
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Affiliation(s)
- Janusz Blasiak
- Department of Molecular Genetics, University of Lodz, Pomorska 141/143, 90-236, Lodz, Poland.
| | - Piotr Sobczuk
- Emergency Medicine and Disaster Medicine Department, Medical University of Lodz, Pomorska 251, 92-209 Lodz, Poland; Department of Orthopaedics and Traumatology, Polish Mothers' Memorial Hospital - Research Institute, Rzgowska 281, 93-338 Lodz, Poland
| | - Elzbieta Pawlowska
- Department of Pediatric Dentistry, Medical University of Lodz, Pomorska 251, 92-216 Lodz, Poland
| | - Kai Kaarniranta
- Department of Ophthalmology, Institute of Clinical Medicine, University of Eastern Finland, P.O. Box 1627, FI-70211, Kuopio, Finland; Department of Ophthalmology, Kuopio University Hospital, KYS, P.O. Box 100, FI-70029 Finland
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4
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Duarri A, Rodríguez-Bocanegra E, Martínez-Navarrete G, Biarnés M, García M, Ferraro LL, Kuebler B, Aran B, Izquierdo E, Aguilera-Xiol E, Casaroli-Marano RP, Trias E, Fernandez E, Raya Á, Veiga A, Monés J. Transplantation of Human Induced Pluripotent Stem Cell-Derived Retinal Pigment Epithelium in a Swine Model of Geographic Atrophy. Int J Mol Sci 2021; 22:ijms221910497. [PMID: 34638840 PMCID: PMC8508834 DOI: 10.3390/ijms221910497] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Revised: 09/24/2021] [Accepted: 09/24/2021] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND The aim of this study was to test the feasibility and safety of subretinal transplantation of human induced pluripotent stem cell (hiPSC)-derived retinal pigment epithelium (RPE) cells into the healthy margins and within areas of degenerative retina in a swine model of geographic atrophy (GA). METHODS Well-delimited selective outer retinal damage was induced by subretinal injection of NaIO3 into one eye in minipigs (n = 10). Thirty days later, a suspension of hiPSC-derived RPE cells expressing green fluorescent protein was injected into the subretinal space, into the healthy margins, and within areas of degenerative retina. In vivo follow-up was performed by multimodal imaging. Post-mortem retinas were analyzed by immunohistochemistry and histology. RESULTS In vitro differentiated hiPSC-RPE cells showed a typical epithelial morphology, expressed RPE-related genes, and had phagocytic ability. Engrafted hiPSC-RPE cells were detected in 60% of the eyes, forming mature epithelium in healthy retina extending towards the border of the atrophy. Histological analysis revealed RPE interaction with host photoreceptors in the healthy retina. Engrafted cells in the atrophic zone were found in a patchy distribution but failed to form an epithelial-like layer. CONCLUSIONS These results might support the use of hiPSC-RPE cells to treat atrophic GA by providing a housekeeping function to aid the overwhelmed remnant RPE, which might improve its survival and therefore slow down the progression of GA.
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Affiliation(s)
- Anna Duarri
- Program for Clinical Translation of Regenerative Medicine in Catalonia–P-CMR[C], Bellvitge Biomedical Research Institute (IDIBELL), Hospitalet de Llobregat, 08908 Barcelona, Spain; (A.D.); (B.K.); (B.A.); (Á.R.)
- National Stem Cell Bank-Barcelona Node, Biomolecular and Bioinformatics Resources Platform PRB2, ISCIII, IDIBELL, Hospitalet de Llobregat, 08908 Barcelona, Spain
- Ophthalmology Research Group, Vall d’Hebron Institut de Recerca (VHIR), 08036 Barcelona, Spain
| | - Eduardo Rodríguez-Bocanegra
- Barcelona Macula Foundation: Research for Vision, 08022 Barcelona, Spain; (E.R.-B.); (M.B.); (M.G.); (L.L.F.)
- Institut de la Màcula, Centro Médico Teknon, 08022 Barcelona, Spain
| | - Gema Martínez-Navarrete
- Networking Research Center of Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), 28029 Madrid, Spain; (G.M.-N.); (E.F.)
- Institute of Bioengineering, Universidad Miguel Hernández, 03202 Alicante, Spain
| | - Marc Biarnés
- Barcelona Macula Foundation: Research for Vision, 08022 Barcelona, Spain; (E.R.-B.); (M.B.); (M.G.); (L.L.F.)
- Institut de la Màcula, Centro Médico Teknon, 08022 Barcelona, Spain
| | - Miriam García
- Barcelona Macula Foundation: Research for Vision, 08022 Barcelona, Spain; (E.R.-B.); (M.B.); (M.G.); (L.L.F.)
- Institut de la Màcula, Centro Médico Teknon, 08022 Barcelona, Spain
| | - Lucía Lee Ferraro
- Barcelona Macula Foundation: Research for Vision, 08022 Barcelona, Spain; (E.R.-B.); (M.B.); (M.G.); (L.L.F.)
- Institut de la Màcula, Centro Médico Teknon, 08022 Barcelona, Spain
| | - Bernd Kuebler
- Program for Clinical Translation of Regenerative Medicine in Catalonia–P-CMR[C], Bellvitge Biomedical Research Institute (IDIBELL), Hospitalet de Llobregat, 08908 Barcelona, Spain; (A.D.); (B.K.); (B.A.); (Á.R.)
| | - Begoña Aran
- Program for Clinical Translation of Regenerative Medicine in Catalonia–P-CMR[C], Bellvitge Biomedical Research Institute (IDIBELL), Hospitalet de Llobregat, 08908 Barcelona, Spain; (A.D.); (B.K.); (B.A.); (Á.R.)
- National Stem Cell Bank-Barcelona Node, Biomolecular and Bioinformatics Resources Platform PRB2, ISCIII, IDIBELL, Hospitalet de Llobregat, 08908 Barcelona, Spain
| | | | | | - Ricardo P. Casaroli-Marano
- Banc de Sang i Teixits (BST), Institute of Biomedical Research (IIB-Sant Pau), 08025 Barcelona, Spain;
- Department of Surgery, School of Medicine and Health Science, Hospital Clinic de Barcelona, University of Barcelona, 08036 Barcelona, Spain
| | - Esteve Trias
- LEITAT Technological Center, 08005 Barcelona, Spain;
- Advanced Therapies Unit, Hospital Clínic de Barcelona, 08005 Barcelona, Spain
| | - Eduardo Fernandez
- Networking Research Center of Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), 28029 Madrid, Spain; (G.M.-N.); (E.F.)
- Institute of Bioengineering, Universidad Miguel Hernández, 03202 Alicante, Spain
| | - Ángel Raya
- Program for Clinical Translation of Regenerative Medicine in Catalonia–P-CMR[C], Bellvitge Biomedical Research Institute (IDIBELL), Hospitalet de Llobregat, 08908 Barcelona, Spain; (A.D.); (B.K.); (B.A.); (Á.R.)
- Networking Research Center of Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), 28029 Madrid, Spain; (G.M.-N.); (E.F.)
- Institució Catalana de Recerca i Estudis Avançats (ICREA), 08010 Barcelona, Spain
| | - Anna Veiga
- Program for Clinical Translation of Regenerative Medicine in Catalonia–P-CMR[C], Bellvitge Biomedical Research Institute (IDIBELL), Hospitalet de Llobregat, 08908 Barcelona, Spain; (A.D.); (B.K.); (B.A.); (Á.R.)
- National Stem Cell Bank-Barcelona Node, Biomolecular and Bioinformatics Resources Platform PRB2, ISCIII, IDIBELL, Hospitalet de Llobregat, 08908 Barcelona, Spain
- Correspondence: (A.V.); (J.M.)
| | - Jordi Monés
- Barcelona Macula Foundation: Research for Vision, 08022 Barcelona, Spain; (E.R.-B.); (M.B.); (M.G.); (L.L.F.)
- Institut de la Màcula, Centro Médico Teknon, 08022 Barcelona, Spain
- Correspondence: (A.V.); (J.M.)
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5
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Csincsik L, Quinn N, Yong KXX, Crutch SJ, Peto T, Lengyel I. Retinal phenotyping of variants of Alzheimer's disease using ultra-widefield retinal images. ALZHEIMER'S & DEMENTIA (AMSTERDAM, NETHERLANDS) 2021; 13:e12232. [PMID: 34458553 PMCID: PMC8377778 DOI: 10.1002/dad2.12232] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 06/25/2021] [Accepted: 07/01/2021] [Indexed: 11/19/2022]
Abstract
BACKGROUND Posterior cortical atrophy (PCA) is the most common atypical variant of Alzheimer's disease (AD). Changes associated with PCA in the brain affect the visual cortex, but little is known about retinal changes in PCA. In this study, we explored retinal phenotypic variations in typical AD (tAD) and PCA. METHODS Retinal phenotyping was carried out on ultra-widefield (UWF) images of 69 control, 24 tAD, and 25 PCA participants. RESULTS Individuals with tAD (odds ratio [OR] = 2.76 [confidence interval (CI):1.24 to 6.10], P = .012) and PCA (OR = 3.40 [CI:1.25 to 9.22], P = .016) were more likely phenotyped as hard drusen. tAD (OR = 0.34 [CI:0.12 to 0.92], P = .035) were less likely to have soft drusen compared to control. Almost 3-fold increase in reticular pseudodrusen formation in tAD (OR = 2.93 [CI:1.10 to 7.76], P = .030) compared to control was estimated. DISCUSSION Studying the peripheral retina may contribute to a better understanding of differences in retinal phenotypes of different AD variants.
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Affiliation(s)
- Lajos Csincsik
- Wellcome‐Wolfson Institute for Experimental MedicineQueen's University BelfastBelfastUK
| | - Nicola Quinn
- Centre for Public HealthQueen's University BelfastBelfastUK
| | - Keir X. X. Yong
- Dementia Research CentreUCL Queen Square Institute of NeurologyUniversity College LondonLondonUK
| | - Sebastian J. Crutch
- Dementia Research CentreUCL Queen Square Institute of NeurologyUniversity College LondonLondonUK
| | - Tunde Peto
- Centre for Public HealthQueen's University BelfastBelfastUK
| | - Imre Lengyel
- Wellcome‐Wolfson Institute for Experimental MedicineQueen's University BelfastBelfastUK
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Dlouha L, Pelikanova T, Veleba J, Adamkova V, Lanska V, Sosna T, Pacal L, Kankova K, Hubacek JA. The APOE4 allele is associated with a decreased risk of retinopathy in type 2 diabetics. Mol Biol Rep 2021; 48:5873-5879. [PMID: 34328600 DOI: 10.1007/s11033-021-06581-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Accepted: 07/20/2021] [Indexed: 11/25/2022]
Abstract
BACKGROUND Common polymorphisms within the apolipoprotein E (APOE) gene are suggested to be associated with the development of type 2 diabetes mellitus (T2DM), but the potential association with T2DM complications (nephropathy, neuropathy and retinopathy) remains unclear. We perform the case-control study to analyse the association between the APOE polymorphism and risk of T2DM and to analysed the potential relationship between the APOE and T2DM complications. METHODS AND RESULTS APOE variants (rs429358 and rs7412) were genotyped by TaqMan assay in T2DM patients (N = 1274; N = 829 with complications including retinopathy, neuropathy and nephropathy status) and with PCR-RFLP in healthy nondiabetic controls (N = 2055). The comparison of subjects with genotypes associated with low plasma cholesterol (APOE2/E2 and APOE2/E3 carriers vs. others) did not show an association with T2DM (OR [95% CI] = 0.88 [0.71-1.08). The differences remained insignificant after adjusting for diabetes duration, sex and BMI. Carriers of at least one APOE4 allele (rs429358) are protected against T2DM related retinopathy (OR [95% CI] = 0.65 [0.42-0.99]. Protection against retinopathy is driven mostly by females (OR [95% CI] = 0.50 [0.25-0.99]); and remains significant (P = 0.044) after adjustment for diabetes duration and BMI. CONCLUSION Common APOE polymorphism was not associated with T2DM in the Czech population. Yet, APOE4 allele revealed an association with retinopathy. In particular, female T2DM patients with at least one APOE4 allele exhibit lower prevalence of retinopathy in our study subjects.
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Affiliation(s)
- Lucie Dlouha
- Experimental Medicine Centre, Institute for Clinical and Experimental Medicine, Videnska 1958/9, Prague, 14021, Czech Republic
- Department of Anthropology and Human Genetics, Faculty of Science, Charles University, Vinicka 7, 12808, Prague, Czech Republic
| | - Terezie Pelikanova
- Diabetes Centre, Institute for Clinical and Experimental Medicine, Videnska 1958/9, Prague, 14021, Czech Republic
| | - Jiří Veleba
- Diabetes Centre, Institute for Clinical and Experimental Medicine, Videnska 1958/9, Prague, 14021, Czech Republic
| | - Vera Adamkova
- Department of Preventive Cardiology, Institute for Clinical and Experimental Medicine, Videnska 1958/9, Prague, 14021, Czech Republic
| | - Vera Lanska
- Statistical Unit, Institute for Clinical and Experimental Medicine, Videnska 1958/9, Prague, 14021, Czech Republic
| | - Tomas Sosna
- Diabetes Centre, Institute for Clinical and Experimental Medicine, Videnska 1958/9, Prague, 14021, Czech Republic
| | - Lukas Pacal
- Department of Pathophysiology, Faculty of Medicine, Masaryk University, Kamenice 753/5, 62500, Brno, Czech Republic
| | - Katerina Kankova
- Department of Pathophysiology, Faculty of Medicine, Masaryk University, Kamenice 753/5, 62500, Brno, Czech Republic
| | - Jaroslav A Hubacek
- Experimental Medicine Centre, Institute for Clinical and Experimental Medicine, Videnska 1958/9, Prague, 14021, Czech Republic.
- 3rd Department of Internal Medicine, 1st Faculty of Medicine, Charles University, U Nemocnice 1, 12808, Prague, Czech Republic.
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Foveal Avascular Zone and Choroidal Thickness Are Decreased in Subjects with Hard Drusen and without High Genetic Risk of Developing Alzheimer's Disease. Biomedicines 2021; 9:biomedicines9060638. [PMID: 34199664 PMCID: PMC8229973 DOI: 10.3390/biomedicines9060638] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 06/01/2021] [Accepted: 06/01/2021] [Indexed: 01/08/2023] Open
Abstract
A family history (FH+) of Alzheimer’s disease (AD) and ɛ4 allele of the ApoE gene are the main genetic risk factors for developing AD, whereas ɛ4 allele plays a protective role in age-related macular degeneration. Ocular vascular changes have been reported in both pathologies. We analyzed the choroidal thickness using optical coherence tomography (OCT) and the foveal avascular zone (FAZ) using OCT-angiography and compared the results with ApoE gene expression, AD FH+, and the presence or absence of hard drusen (HD) in 184 cognitively healthy subjects. Choroidal thickness was statistically significantly different in the (FH−, ɛ4−, HD+) group compared with (i) both the (FH−, ɛ4−, HD−) and the (FH+, ɛ4+, HD+) groups in the superior and inferior points at 1500 μm, and (ii) the (FH+, ɛ4−, HD+) group in the superior point at 1500 μm. There were statistically significant differences in the superficial FAZ between the (FH+, ɛ4−, HD+) group and (i) the (FH+, ɛ4−, HD−) group and (ii) the (FH+, ɛ4+, HD−) group. In conclusion, ocular vascular changes are not yet evident in participants with a genetic risk of developing AD.
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8
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La Cunza N, Tan LX, Thamban T, Germer CJ, Rathnasamy G, Toops KA, Lakkaraju A. Mitochondria-dependent phase separation of disease-relevant proteins drives pathological features of age-related macular degeneration. JCI Insight 2021; 6:142254. [PMID: 33822768 PMCID: PMC8262309 DOI: 10.1172/jci.insight.142254] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Accepted: 03/31/2021] [Indexed: 01/21/2023] Open
Abstract
Age-related macular degeneration (AMD) damages the retinal pigment epithelium (RPE), the tissue that safeguards photoreceptor health, leading to irreversible vision loss. Polymorphisms in cholesterol and complement genes are implicated in AMD, yet mechanisms linking risk variants to RPE injury remain unclear. We sought to determine how allelic variants in the apolipoprotein E cholesterol transporter modulate RPE homeostasis and function. Using live-cell imaging, we show that inefficient cholesterol transport by the AMD risk-associated ApoE2 increases RPE ceramide, leading to autophagic defects and complement-mediated mitochondrial damage. Mitochondrial injury drives redox state–sensitive cysteine-mediated phase separation of ApoE2, forming biomolecular condensates that could nucleate drusen. The protective ApoE4 isoform lacks these cysteines and is resistant to phase separation and condensate formation. In Abca–/– Stargardt macular degeneration mice, mitochondrial dysfunction induces liquid-liquid phase separation of p62/SQSTM1, a multifunctional protein that regulates autophagy. Drugs that decrease RPE cholesterol or ceramide prevent mitochondrial injury and phase separation in vitro and in vivo. In AMD donor RPE, mitochondrial fragmentation correlates with ApoE and p62 condensates. Our studies demonstrate that major AMD genetic and biological risk pathways converge upon RPE mitochondria, and identify mitochondrial stress-mediated protein phase separation as an important pathogenic mechanism and promising therapeutic target in AMD.
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Affiliation(s)
- Nilsa La Cunza
- Department of Ophthalmology, School of Medicine, and.,Pharmaceutical Sciences and Pharmacogenomics Graduate Program, Graduate Division, University of California, San Francisco, California, USA
| | - Li Xuan Tan
- Department of Ophthalmology, School of Medicine, and
| | | | - Colin J Germer
- Department of Ophthalmology, School of Medicine, and.,Pharmaceutical Sciences and Pharmacogenomics Graduate Program, Graduate Division, University of California, San Francisco, California, USA
| | | | - Kimberly A Toops
- Department of Ophthalmology and Visual Sciences, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Aparna Lakkaraju
- Department of Ophthalmology, School of Medicine, and.,Pharmaceutical Sciences and Pharmacogenomics Graduate Program, Graduate Division, University of California, San Francisco, California, USA.,Department of Anatomy, School of Medicine, University of California, San Francisco, California, USA
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9
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Tan LX, Germer CJ, La Cunza N, Lakkaraju A. Complement activation, lipid metabolism, and mitochondrial injury: Converging pathways in age-related macular degeneration. Redox Biol 2020; 37:101781. [PMID: 33162377 PMCID: PMC7767764 DOI: 10.1016/j.redox.2020.101781] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2020] [Revised: 10/22/2020] [Accepted: 10/29/2020] [Indexed: 02/07/2023] Open
Abstract
The retinal pigment epithelium (RPE) is the primary site of injury in non-neovascular age-related macular degeneration or dry AMD. Polymorphisms in genes that regulate complement activation and cholesterol metabolism are strongly associated with AMD, but the biology underlying disease-associated variants is not well understood. Here, we highlight recent studies that have used molecular, biochemical, and live-cell imaging methods to elucidate mechanisms by which aging-associated insults conspire with AMD genetic risk variants to tip the balance towards disease. We discuss how critical functions including lipid metabolism, autophagy, complement regulation, and mitochondrial dynamics are compromised in the RPE, and how a deeper understanding of these mechanisms has helped identify promising therapeutic targets to preserve RPE homeostasis in AMD.
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Affiliation(s)
- Li Xuan Tan
- Department of Ophthalmology, School of Medicine, University of California, San Francisco, CA, USA
| | - Colin J Germer
- Department of Ophthalmology, School of Medicine, University of California, San Francisco, CA, USA; Pharmaceutical Sciences and Pharmacogenomics Graduate Program, University of California, San Francisco, CA, USA
| | - Nilsa La Cunza
- Department of Ophthalmology, School of Medicine, University of California, San Francisco, CA, USA; Pharmaceutical Sciences and Pharmacogenomics Graduate Program, University of California, San Francisco, CA, USA
| | - Aparna Lakkaraju
- Department of Ophthalmology, School of Medicine, University of California, San Francisco, CA, USA; Pharmaceutical Sciences and Pharmacogenomics Graduate Program, University of California, San Francisco, CA, USA; Department of Anatomy, School of Medicine, University of California, San Francisco, CA, USA.
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10
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Raghavachari N. The Impact of Apolipoprotein E Genetic Variability in Health and Life Span. J Gerontol A Biol Sci Med Sci 2020; 75:1855-1857. [PMID: 32789475 DOI: 10.1093/gerona/glaa175] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Indexed: 11/12/2022] Open
Affiliation(s)
- Nalini Raghavachari
- Division of Geriatrics and Clinical Gerontology, National Institute on Aging, NIH, Bethesda, Maryland
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11
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APOE2 promotes the development and progression of subretinal neovascularization in age-related macular degeneration via MAPKs signaling pathway. Saudi J Biol Sci 2020; 27:2770-2777. [PMID: 32994736 PMCID: PMC7499293 DOI: 10.1016/j.sjbs.2020.06.037] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 06/19/2020] [Accepted: 06/22/2020] [Indexed: 12/11/2022] Open
Abstract
Background Neovascular age-related macular degeneration (nvAMD) is one of the main pathological features of wet AMD. Apolipoprotein E2 is involved in the formation of nvAMD but the molecular mechanism has not been reported. Methods The APOE alleles in AMD patients were detected by genotyping. Mouse models were divided into 4 groups according to transfection different gene segments and laser-induced treatment. APOE2, VEGF, PDGF-BB, b-FGF and inflammatory cytokines (including p-NF-κB, TNF-α, IL-1β and IL-6) were tested by ELISA in mice retinal lysate. The formation of nvAMD in the indicated treatment groups at 3rd, 7th and 14th day after laser-induced damage were detected by FFA. Besides, qRT-PCR was used to determine the mRNA levels of p38, JNK and ERK in ARPE-19 cells. Finally, the inflammatory cytokines and MAPK proteins (including P38, p-P38, JNK, p-JNK, ERK and p-ERK) were detected by western blot. Results The statistics of APOE alleles showed that APOE2 allele carriers were more likely to nvAMD. VEGF, PDGF-BB, b-FGF and related inflammatory cytokines were up-regulated significantly after treatment with APOE2, which were reduced after silencing the MAPK family genes, however. Further, the expression levels of neovascular growth factors and inflammatory cytokines were highly consistent between mouse models and ARPE-19 cells. Besides, the phosphorylation levels of p38, JNK and ERK were affected by APOE2. Conclusion nvAMD was affected directly by the overexpression of VEGF, PDGF-BB and b-FGF, which were regulated by APOE2 through activating MAPKs pathway.
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12
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Conner SC, Benayoun L, Himali JJ, Adams SL, Yang Q, DeCarli C, Blusztajn JK, Beiser A, Seshadri S, Delalle I. Methionine Sulfoxide Reductase-B3 Risk Allele Implicated in Alzheimer's Disease Associates with Increased Odds for Brain Infarcts. J Alzheimers Dis 2020; 68:357-365. [PMID: 30775993 DOI: 10.3233/jad-180977] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Genome-wide association studies identified a single nucleotide polymorphism (SNP) in the MSRB3 gene encoding Methionine Sulfoxide Reductase-B3 (MsrB3) to be associated with the risk for low hippocampal volume and late onset Alzheimer's disease (AD). Subsequently, we identified AD-associated abnormal patterns of neuronal and vascular MsrB3 expression in postmortem hippocampi. The present study investigated the relationship between the MSRB3 SNP rs61921502, G (minor/risk allele) and MRI measures of brain injury including total brain volume, hippocampal volume, and white matter hyperintensities using linear regression models; the presence of brain infarcts using logistic regression models; and the incidence of stroke, dementia, and AD using Cox proportional hazards models in 2,038 Framingham Heart Study Offspring participants with MRI administered close to examination cycle 7 (1998-2001). Participants with neurological conditions that impede evaluation of vascular pathology by MRI, i.e., brain tumors, multiple sclerosis, and major head trauma, were excluded from the study. When adjusted for age and age squared at MRI exam, sex, and presence of Apolipoproteinɛ4 allele (APOE4), individuals with MSRB3 rs61921502 minor allele had increased odds for brain infarcts on MRI compared to those with no minor allele. However, in stratified analyses, MSRB3 rs61921502 minor allele was significantly associated with increased odds for MRI brain infarcts only in the absence of APOE4.
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Affiliation(s)
- Sarah C Conner
- Framingham Heart Study, Boston University School of Public Health, Boston, MA, USA.,Department of Biostatistics, Boston University School of Public Health, Boston, MA, USA
| | - Laurent Benayoun
- Department of Pathology and Laboratory Medicine, Boston University School of Medicine, Boston, MA, USA
| | - Jayandra J Himali
- Framingham Heart Study, Boston University School of Public Health, Boston, MA, USA.,Department of Biostatistics, Boston University School of Public Health, Boston, MA, USA.,Department of Neurology, Boston University School of Medicine, Boston, MA, USA
| | - Stephanie L Adams
- Department of Pathology and Laboratory Medicine, Boston University School of Medicine, Boston, MA, USA
| | - Qiong Yang
- Framingham Heart Study, Boston University School of Public Health, Boston, MA, USA.,Department of Biostatistics, Boston University School of Public Health, Boston, MA, USA
| | - Charles DeCarli
- Department of Neurology, University of California Davis School of Medicine, Sacramento, CA, USA
| | - Jan K Blusztajn
- Department of Pathology and Laboratory Medicine, Boston University School of Medicine, Boston, MA, USA
| | - Alexa Beiser
- Framingham Heart Study, Boston University School of Public Health, Boston, MA, USA.,Department of Biostatistics, Boston University School of Public Health, Boston, MA, USA.,Department of Neurology, Boston University School of Medicine, Boston, MA, USA
| | - Sudha Seshadri
- Framingham Heart Study, Boston University School of Public Health, Boston, MA, USA.,Department of Neurology, Boston University School of Medicine, Boston, MA, USA
| | - Ivana Delalle
- Department of Pathology and Laboratory Medicine, Boston University School of Medicine, Boston, MA, USA.,Department of Neurology, Boston University School of Medicine, Boston, MA, USA
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13
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Heesterbeek TJ, Lorés-Motta L, Hoyng CB, Lechanteur YTE, den Hollander AI. Risk factors for progression of age-related macular degeneration. Ophthalmic Physiol Opt 2020; 40:140-170. [PMID: 32100327 PMCID: PMC7155063 DOI: 10.1111/opo.12675] [Citation(s) in RCA: 176] [Impact Index Per Article: 44.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Accepted: 01/18/2020] [Indexed: 12/18/2022]
Abstract
Purpose Age‐related macular degeneration (AMD) is a degenerative disease of the macula, often leading to progressive vision loss. The rate of disease progression can vary among individuals and has been associated with multiple risk factors. In this review, we provide an overview of the current literature investigating phenotypic, demographic, environmental, genetic, and molecular risk factors, and propose the most consistently identified risk factors for disease progression in AMD based on these studies. Finally, we describe the potential use of these risk factors for personalised healthcare. Recent findings While phenotypic risk factors such as drusen and pigment abnormalities become more important to predict disease progression during the course of the disease, demographic, environmental, genetic and molecular risk factors are more valuable at earlier disease stages. Demographic and environmental risk factors such as age and smoking are consistently reported to be related to disease progression, while other factors such as sex, body mass index (BMI) and education are less often associated. Of all known AMD variants, variants that are most consistently reported with disease progression are rs10922109 and rs570618 in CFH, rs116503776 in C2/CFB/SKIV2L, rs3750846 in ARMS2/HTRA1 and rs2230199 in C3. However, it seems likely that other AMD variants also contribute to disease progression but to a lesser extent. Rare variants have probably a large effect on disease progression in highly affected families. Furthermore, current prediction models do not include molecular risk factors, while these factors can be measured accurately in the blood. Possible promising molecular risk factors are High‐Density Lipoprotein Cholesterol (HDL‐C), Docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), zeaxanthin and lutein. Summary Phenotypic, demographic, environmental, genetic and molecular risk factors can be combined in prediction models to predict disease progression, but the selection of the proper risk factors for personalised risk prediction will differ among individuals and is dependent on their current disease stage. Future prediction models should include a wider set of genetic variants to determine the genetic risk more accurately, and rare variants should be taken into account in highly affected families. In addition, adding molecular factors in prediction models may lead to preventive strategies and personalised advice.
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Affiliation(s)
- Thomas J Heesterbeek
- Departments of, Department of, Ophthalmology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Laura Lorés-Motta
- Departments of, Department of, Ophthalmology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands.,Department of, Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Carel B Hoyng
- Departments of, Department of, Ophthalmology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Yara T E Lechanteur
- Departments of, Department of, Ophthalmology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Anneke I den Hollander
- Departments of, Department of, Ophthalmology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands.,Department of, Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
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14
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Pool FM, Kiel C, Serrano L, Luthert PJ. Repository of proposed pathways and protein-protein interaction networks in age-related macular degeneration. NPJ Aging Mech Dis 2020; 6:2. [PMID: 31934346 PMCID: PMC6946811 DOI: 10.1038/s41514-019-0039-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Accepted: 11/18/2019] [Indexed: 12/21/2022] Open
Abstract
Age-related macular degeneration (AMD) is one of the commonest causes of sight loss in the elderly population and to date there is no intervention that slows or prevents early AMD disease progressing to blinding neovascularization or geographic atrophy. AMD is a complex disease and factors proposed to contribute to the development and progression of disease include aging, genetics, epigenetics, oxidative stress, pro-inflammatory state, and life-style factors such as smoking, alcohol, and high fat diet. Here, we generate a knowledge repository of pathways and protein–protein interaction (PPI) networks likely to be implicated in AMD pathogenesis, such as complement activation, lipid trafficking and metabolism, vitamin A cycle, oxidative stress, proteostasis, bioenergetics, autophagy/mitophagy, extracellular matrix (ECM) turnover, and choroidal vascular dropout. Two disctinct clusters ermerged from the networks for parainflamation and ECM homeostasis, which may represent two different disease modules underlying AMD pathology. Our analyses also suggest that the disease manifests primarily in RPE/choroid and less in neural retina. The use of standardized syntax when generating maps of these biological processes (SBGN standard) and networks (PSI standard) enables visualization of complex information in graphical programs such as CellDesigner and Cytoscape and enhances reusability and extension of data. The ability to focus onto subnetworks, multiple visualizations and simulation options will enable the AMD research community to computationally model subnetworks or to test experimentally new hypotheses arising from connectivities in the AMD pathway map.
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Affiliation(s)
- Fran M Pool
- 1UCL Institute of Ophthalmology, and NIHR Moorfields Biomedical Research Centre, University College London, 11-43 Bath Street, London, EC1V 9EL UK
| | - Christina Kiel
- 2Systems Biology Ireland & Charles Institute of Dermatology & School of Medicine, University College Dublin, Belfield Dublin, 4 Ireland
| | - Luis Serrano
- 3Centre for Genomic Regulation (CRG), Systems Biology Programme. The Barcelona Institute of Science and Technology, Dr. Aiguader 88, Barcelona, 08003 Spain.,4Universitat Pompeu Fabra (UPF), Barcelona, 08003 Spain.,5Institució Catalana de Recerca i Estudis Avançats (ICREA), Pg. Lluis Companys 23, Barcelona, 08010 Spain
| | - Philip J Luthert
- 1UCL Institute of Ophthalmology, and NIHR Moorfields Biomedical Research Centre, University College London, 11-43 Bath Street, London, EC1V 9EL UK
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15
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McGuinness MB, Kasza J, Karahalios A, Guymer RH, Finger RP, Simpson JA. A comparison of methods to estimate the survivor average causal effect in the presence of missing data: a simulation study. BMC Med Res Methodol 2019; 19:223. [PMID: 31795945 PMCID: PMC6892197 DOI: 10.1186/s12874-019-0874-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Accepted: 11/20/2019] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND Attrition due to death and non-attendance are common sources of bias in studies of age-related diseases. A simulation study is presented to compare two methods for estimating the survivor average causal effect (SACE) of a binary exposure (sex-specific dietary iron intake) on a binary outcome (age-related macular degeneration, AMD) in this setting. METHODS A dataset of 10,000 participants was simulated 1200 times under each scenario with outcome data missing dependent on measured and unmeasured covariates and survival. Scenarios differed by the magnitude and direction of effect of an unmeasured confounder on both survival and the outcome, and whether participants who died following a protective exposure would also die if they had not received the exposure (validity of the monotonicity assumption). The performance of a marginal structural model (MSM, weighting for exposure, survival and missing data) was compared to a sensitivity approach for estimating the SACE. As an illustrative example, the SACE of iron intake on AMD was estimated using data from 39,918 participants of the Melbourne Collaborative Cohort Study. RESULTS The MSM approach tended to underestimate the true magnitude of effect when the unmeasured confounder had opposing directions of effect on survival and the outcome. Overestimation was observed when the unmeasured confounder had the same direction of effect on survival and the outcome. Violation of the monotonicity assumption did not increase bias. The estimates were similar between the MSM approach and the sensitivity approach assessed at the sensitivity parameter of 1 (assuming no survival bias). In the illustrative example, high iron intake was found to be protective of AMD (adjusted OR 0.57, 95% CI 0.40-0.82) using complete case analysis via traditional logistic regression. The adjusted SACE odds ratio did not differ substantially from the complete case estimate, ranging from 0.54 to 0.58 for each of the SACE methods. CONCLUSIONS On average, MSMs with weighting for exposure, missing data and survival produced biased estimates of the SACE in the presence of an unmeasured survival-outcome confounder. The direction and magnitude of effect of unmeasured survival-outcome confounders should be considered when assessing exposure-outcome associations in the presence of attrition due to death.
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Affiliation(s)
- Myra B. McGuinness
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Australia
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, Melbourne, Australia
| | - Jessica Kasza
- Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, Victoria 3010 Australia
| | - Amalia Karahalios
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, Melbourne, Australia
| | - Robyn H. Guymer
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Australia
- Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, Australia
| | | | - Julie A. Simpson
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, Melbourne, Australia
- Cancer Epidemiology Centre, Cancer Council Victoria, Melbourne, Australia
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16
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Meyer JG, Garcia TY, Schilling B, Gibson BW, Lamba DA. Proteome and Secretome Dynamics of Human Retinal Pigment Epithelium in Response to Reactive Oxygen Species. Sci Rep 2019; 9:15440. [PMID: 31659173 PMCID: PMC6817852 DOI: 10.1038/s41598-019-51777-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Accepted: 10/04/2019] [Indexed: 12/22/2022] Open
Abstract
Age-related macular degeneration (AMD) is the leading cause of blindness in developed countries, and is characterized by slow retinal degeneration linked to chronic reactive oxygen species (ROS) in the retinal pigmented epithelium (RPE). The molecular mechanisms leading to RPE dysfunction in response to ROS are unclear. Here, human stem cell-derived RPE samples were stressed with ROS for 1 or 3 weeks, and both intracellular and secreted proteomes were quantified by mass spectrometry. ROS increased glycolytic proteins but decreased mitochondrial complex I subunits, as well as membrane proteins required for endocytosis. RPE secreted over 1,000 proteins, many of which changed significantly due to ROS. Notably, secreted APOE is decreased 4-fold, and urotensin-II, the strongest known vasoconstrictor, doubled. Furthermore, secreted TGF-beta is increased, and its cognate signaler BMP1 decreased in the secretome. Together, our results paint a detailed molecular picture of the retinal stress response in space and time.
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Affiliation(s)
- Jesse G Meyer
- Buck Institute for Research on Aging, Novato, CA, 94945, USA.
- Department of Chemistry, Department of Biomolecular Chemistry, National Center for Quantitative Biology of Complex Systems, University of Wisconsin - Madison, Madison, WI, 53706, USA.
| | - Thelma Y Garcia
- Buck Institute for Research on Aging, Novato, CA, 94945, USA
| | | | - Bradford W Gibson
- Buck Institute for Research on Aging, Novato, CA, 94945, USA
- Discovery Attribute Sciences, Research, Amgen, South San Francisco, CA, 94080, USA
| | - Deepak A Lamba
- Buck Institute for Research on Aging, Novato, CA, 94945, USA.
- Department of Ophthalmology, Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California - San Francisco, San Francisco, CA, 94143, USA.
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17
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On the origin of proteins in human drusen: The meet, greet and stick hypothesis. Prog Retin Eye Res 2018; 70:55-84. [PMID: 30572124 DOI: 10.1016/j.preteyeres.2018.12.003] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Revised: 12/11/2018] [Accepted: 12/12/2018] [Indexed: 12/12/2022]
Abstract
Retinal drusen formation is not only a clinical hallmark for the development of age-related macular degeneration (AMD) but also for other disorders, such as Alzheimer's disease and renal diseases. The initiation and growth of drusen is poorly understood. Attention has focused on lipids and minerals, but relatively little is known about the origin of drusen-associated proteins and how they are retained in the space between the basal lamina of the retinal pigment epithelium and the inner collagenous layer space (sub-RPE-BL space). While some authors suggested that drusen proteins are mainly derived from cellular debris from processed photoreceptor outer segments and the RPE, others suggest a choroidal cell or blood origin. Here, we reviewed and supplemented the existing literature on the molecular composition of the retina/choroid complex, to gain a more complete understanding of the sources of proteins in drusen. These "drusenomics" studies showed that a considerable proportion of currently identified drusen proteins is uniquely originating from the blood. A smaller, but still large fraction of drusen proteins comes from both blood and/or RPE. Only a small proportion of drusen proteins is uniquely derived from the photoreceptors or choroid. We next evaluated how drusen components may "meet, greet and stick" to each other and/or to structures like hydroxyapatite spherules to form macroscopic deposits in the sub-RPE-BL space. Finally, we discuss implications of our findings with respect to the previously proposed homology between drusenogenesis in AMD and plaque formation in atherosclerosis.
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18
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Saadane A, Petrov A, Mast N, El-Darzi N, Dao T, Alnemri A, Song Y, Dunaief JL, Pikuleva IA. Mechanisms that minimize retinal impact of apolipoprotein E absence. J Lipid Res 2018; 59:2368-2382. [PMID: 30333155 DOI: 10.1194/jlr.m090043] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Revised: 10/17/2018] [Indexed: 01/28/2023] Open
Abstract
Apolipoprotein E (APOE) is a component of lipid-transporting particles and a recognition ligand for receptors, which bind these particles. The APOE isoform ε2 is a risk factor for age-related macular degeneration; nevertheless, APOE absence in humans and mice does not significantly affect the retina. We found that retinal cholesterol biosynthesis and the levels of retinal cholesterol were increased in Apoe-/- mice, whereas cholesterol elimination by metabolism was decreased. No focal cholesterol deposits were observed in the Apoe-/- retina. Retinal proteomics identified the most abundant cholesterol-related proteins in WT mice and revealed that, of these cholesterol-related proteins, only APOA4 had increased expression in the Apoe-/- retina. In addition, there were changes in retinal abundance of proteins involved in proinflammatory and antiinflammatory responses, cellular cytoskeleton maintenance, vesicular traffic, and retinal iron homeostasis. The data obtained indicate that when APOE is absent, particles containing APOA1, APOA4, and APOJ still transport cholesterol in the intraretinal space, but these particles are not taken up by retinal cells. Therefore, cholesterol biosynthesis inside retinal cells increase, whereas metabolism to oxysterols decreases to prevent cells from cholesterol depletion. These and other compensatory changes underlie only a minor retinal phenotype in Apoe-/- mice.
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Affiliation(s)
- Aicha Saadane
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH
| | - Alexey Petrov
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH
| | - Natalia Mast
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH
| | - Nicole El-Darzi
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH
| | - Tung Dao
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH
| | - Ahab Alnemri
- F. M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Ying Song
- F. M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Joshua L Dunaief
- F. M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Irina A Pikuleva
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH
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19
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Apolipoprotein E as a novel therapeutic neuroprotection target after traumatic spinal cord injury. Exp Neurol 2017; 299:97-108. [PMID: 29056364 DOI: 10.1016/j.expneurol.2017.10.014] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Revised: 09/26/2017] [Accepted: 10/17/2017] [Indexed: 11/23/2022]
Abstract
Apolipoprotein E (apoE), a plasma lipoprotein well known for its important role in lipid and cholesterol metabolism, has also been implicated in many neurological diseases. In this study, we examined the effect of apoE on the pathophysiology of traumatic spinal cord injury (SCI). ApoE-deficient mutant (apoE-/-) and wild-type mice received a T9 moderate contusion SCI and were evaluated using histological and behavioral analyses after injury. At 3days after injury, the permeability of spinal cord-blood-barrier, measured by extravasation of Evans blue dye, was significantly increased in apoE-/- mice compared to wild type. The inflammation and spared white matter was also significantly increased and decreased, respectively, in apoE-/- mice compared to the wild type ones. The apoptosis of both neurons and oligodendrocytes was also significantly increased in apoE-/- mice. At 42days after injury, the inflammation was still robust in the injured spinal cord in apoE-/- but not wild type mice. CD45+ leukocytes from peripheral blood persisted in the injured spinal cord of apoE-/- mice. The spared white matter was significantly decreased in apoE-/- mice compared to wild type ones. Locomotor function was significantly decreased in apoE-/- mice compared to wild type ones from week 1 to week 8 after contusion. Treatment of exogenous apoE mimetic peptides partially restored the permeability of spinal cord-blood-barrier in apoE-/- mice after SCI. Importantly, the exogenous apoE peptides decreased inflammation, increased spared white matter and promoted locomotor recovery in apoE-/- mice after SCI. Our results indicate that endogenous apoE plays important roles in maintaining the spinal cord-blood-barrier and decreasing inflammation and spinal cord tissue loss after SCI, suggesting its important neuroprotective function after SCI. Our results further suggest that exogenous apoE mimetic peptides could be a novel and promising neuroprotective reagent for SCI.
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20
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Beta-amyloid sequelae in the eye: a critical review on its diagnostic significance and clinical relevance in Alzheimer's disease. Mol Psychiatry 2017; 22:353-363. [PMID: 28093567 DOI: 10.1038/mp.2016.251] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Revised: 10/31/2016] [Accepted: 11/22/2016] [Indexed: 01/14/2023]
Abstract
Alzheimer's disease (AD) is a progressive and fatal neurodegenerative disorder. There is no test for its definitive diagnosis in routine clinical practice. Although phase III clinical trials have failed, only symptomatic treatment is currently available; a possible reason for these failed trials is that intervention commenced at an advanced stage of the disease. The hallmarks of an AD brain include plaques comprising of extracellular beta-amyloid (Aβ) protein aggregates and intracellular hyperphosphorylated neurofibrillary tangles of tau. Research into the preclinical diagnosis of AD has provided considerable evidence regarding early neuropathological changes using brain Aβ imaging and the cerebrospinal fluid biomarkers, Aβ and tau. Both these approaches have limitations that are expensive, invasive or time consuming and thus preclude them from screening at-risk population. Recent studies have demonstrated the presence of Aβ plaques in the eyes of AD subjects, which is positively associated with their brain Aβ burden. Thus ocular biomarkers point to a potential avenue for an earlier, relatively low-cost diagnosis in order for therapeutic interventions to be effective. Here we review the literature that spans the investigation for the presence of Aβ in aging eyes and the significance of its deposition in relation to AD pathology. We discuss clinical studies investigating in vivo imaging of Aβ in the eye and its association with brain Aβ burden and therapies that target ocular Aβ. Finally, we focus on the need to characterize AD-specific retinal Aβ to differentiate Aβ found in some eye diseases. Based on the current evidence, we conclude that integration of ocular biomarkers that can correctly predict brain Aβ burden would have an important role as a non-invasive, yet economical surrogate marker in the diagnostic process of AD.
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21
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Moriarty PM, Varvel SA, Gordts PLSM, McConnell JP, Tsimikas S. Lipoprotein(a) Mass Levels Increase Significantly According to APOE Genotype: An Analysis of 431 239 Patients. Arterioscler Thromb Vasc Biol 2017; 37:580-588. [PMID: 28062489 DOI: 10.1161/atvbaha.116.308704] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2016] [Accepted: 12/21/2016] [Indexed: 11/16/2022]
Abstract
OBJECTIVE Lipoprotein(a) [Lp(a)] levels are genetically determined by hepatocyte apolipoprotein(a) synthesis, but catabolic pathways also influence circulating levels. APOE genotypes have different affinities for the low-density lipoprotein (LDL) receptor and LDL-related protein-1, with ε2 having the weakest binding to LDL receptor at <2% relative to ε3 and ε4. APPROACH AND RESULTS: APOE genotypes (ε2/ε2, ε2/ε3, ε2/ε4, ε3/ε3, ε3/ε4, and ε4/ε4), Lp(a) mass, directly measured Lp(a)-cholesterol levels, and a variety of apoB-related lipoproteins were measured in 431 239 patients. The prevalence of APOE traits were ε2: 7.35%, ε3: 77.56%, and ε4: 15.09%. Mean (SD) Lp(a) levels were 65% higher in ε4/ε4 compared with ε2/ε2 genotypes and increased significantly according to APOE genotype: ε2/ε2: 23.4 (29.2), ε2/ε3: 31.3 (38.0), ε2/ε4: 32.8 (38.5), ε3/ε3: 33.2 (39.1), ε3/ε4: 35.5 (41.6), and ε4/ε4: 38.5 (44.1) mg/dL (P<0.0001). LDL-cholesterol, apoB, Lp(a)-cholesterol, LDL-cholesterol corrected for Lp(a)-cholesterol content, LDL-particle number, and small, dense LDL also had similar patterns. Patients with LDL-cholesterol ≥250 mg/dL, who are more likely to have LDL receptor mutations and reduced affinity for apoB, had higher Lp(a) levels across all apoE isoforms, but particularly in patients with ε2 alleles, compared with LDL <250 mg/dL. The lowest Lp(a) mass levels were present in patients with ε2 isoforms and lowest LDL-cholesterol. CONCLUSIONS APOE genotypes strongly influence Lp(a) and apoB-related lipoprotein levels. This suggests that differences in affinity of apoE proteins for lipoprotein clearance receptors may affect Lp(a) catabolism, suggesting a competition between Lp(a) and apoE protein for similar receptors.
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Affiliation(s)
- Patrick M Moriarty
- From the Division of Clinical Pharmacology, Department of Internal Medicine, University of Kansas Medical Center, Kansas City (P.M.M.); Salveo Diagnostics, Inc, Richmond, VA (S.A.V., J.P.M.); Department of Cellular and Molecular Medicine, Glycobiology Research and Training Center (P.L.S.M.G.), Department of Medicine, Division of Endocrinology and Metabolism (P.L.S.M.G.), and Division of Cardiovascular Medicine, Sulpizio Cardiovascular Center (S.T.), University of California San Diego, La Jolla
| | - Stephen A Varvel
- From the Division of Clinical Pharmacology, Department of Internal Medicine, University of Kansas Medical Center, Kansas City (P.M.M.); Salveo Diagnostics, Inc, Richmond, VA (S.A.V., J.P.M.); Department of Cellular and Molecular Medicine, Glycobiology Research and Training Center (P.L.S.M.G.), Department of Medicine, Division of Endocrinology and Metabolism (P.L.S.M.G.), and Division of Cardiovascular Medicine, Sulpizio Cardiovascular Center (S.T.), University of California San Diego, La Jolla
| | - Philip L S M Gordts
- From the Division of Clinical Pharmacology, Department of Internal Medicine, University of Kansas Medical Center, Kansas City (P.M.M.); Salveo Diagnostics, Inc, Richmond, VA (S.A.V., J.P.M.); Department of Cellular and Molecular Medicine, Glycobiology Research and Training Center (P.L.S.M.G.), Department of Medicine, Division of Endocrinology and Metabolism (P.L.S.M.G.), and Division of Cardiovascular Medicine, Sulpizio Cardiovascular Center (S.T.), University of California San Diego, La Jolla
| | - Joseph P McConnell
- From the Division of Clinical Pharmacology, Department of Internal Medicine, University of Kansas Medical Center, Kansas City (P.M.M.); Salveo Diagnostics, Inc, Richmond, VA (S.A.V., J.P.M.); Department of Cellular and Molecular Medicine, Glycobiology Research and Training Center (P.L.S.M.G.), Department of Medicine, Division of Endocrinology and Metabolism (P.L.S.M.G.), and Division of Cardiovascular Medicine, Sulpizio Cardiovascular Center (S.T.), University of California San Diego, La Jolla
| | - Sotirios Tsimikas
- From the Division of Clinical Pharmacology, Department of Internal Medicine, University of Kansas Medical Center, Kansas City (P.M.M.); Salveo Diagnostics, Inc, Richmond, VA (S.A.V., J.P.M.); Department of Cellular and Molecular Medicine, Glycobiology Research and Training Center (P.L.S.M.G.), Department of Medicine, Division of Endocrinology and Metabolism (P.L.S.M.G.), and Division of Cardiovascular Medicine, Sulpizio Cardiovascular Center (S.T.), University of California San Diego, La Jolla.
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22
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Lambert NG, ElShelmani H, Singh MK, Mansergh FC, Wride MA, Padilla M, Keegan D, Hogg RE, Ambati BK. Risk factors and biomarkers of age-related macular degeneration. Prog Retin Eye Res 2016; 54:64-102. [PMID: 27156982 DOI: 10.1016/j.preteyeres.2016.04.003] [Citation(s) in RCA: 230] [Impact Index Per Article: 28.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2015] [Revised: 04/01/2016] [Accepted: 04/12/2016] [Indexed: 02/03/2023]
Abstract
A biomarker can be a substance or structure measured in body parts, fluids or products that can affect or predict disease incidence. As age-related macular degeneration (AMD) is the leading cause of blindness in the developed world, much research and effort has been invested in the identification of different biomarkers to predict disease incidence, identify at risk individuals, elucidate causative pathophysiological etiologies, guide screening, monitoring and treatment parameters, and predict disease outcomes. To date, a host of genetic, environmental, proteomic, and cellular targets have been identified as both risk factors and potential biomarkers for AMD. Despite this, their use has been confined to research settings and has not yet crossed into the clinical arena. A greater understanding of these factors and their use as potential biomarkers for AMD can guide future research and clinical practice. This article will discuss known risk factors and novel, potential biomarkers of AMD in addition to their application in both academic and clinical settings.
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Affiliation(s)
- Nathan G Lambert
- Ambati Lab, John A. Moran Eye Center, 65 Mario Capecchi Drive, Salt Lake City, UT, USA; Department of Ophthalmology & Visual Sciences, University of Utah, 65 Mario Capecchi Drive, Salt Lake City, UT, USA.
| | - Hanan ElShelmani
- Ocular Development and Neurobiology Research Group, Zoology Department, School of Natural Sciences, University of Dublin, Trinity College, Dublin 2, Ireland.
| | - Malkit K Singh
- Ambati Lab, John A. Moran Eye Center, 65 Mario Capecchi Drive, Salt Lake City, UT, USA; Department of Ophthalmology & Visual Sciences, University of Utah, 65 Mario Capecchi Drive, Salt Lake City, UT, USA.
| | - Fiona C Mansergh
- Smurfit Institute of Genetics, Trinity College Dublin, Dublin 2, Ireland.
| | - Michael A Wride
- Ocular Development and Neurobiology Research Group, Zoology Department, School of Natural Sciences, University of Dublin, Trinity College, Dublin 2, Ireland.
| | - Maximilian Padilla
- Ambati Lab, John A. Moran Eye Center, 65 Mario Capecchi Drive, Salt Lake City, UT, USA; Department of Ophthalmology & Visual Sciences, University of Utah, 65 Mario Capecchi Drive, Salt Lake City, UT, USA.
| | - David Keegan
- Mater Misericordia Hospital, Eccles St, Dublin 7, Ireland.
| | - Ruth E Hogg
- Centre for Experimental Medicine, Institute of Clinical Science Block A, Grosvenor Road, Belfast, Co.Antrim, Northern Ireland, UK.
| | - Balamurali K Ambati
- Ambati Lab, John A. Moran Eye Center, 65 Mario Capecchi Drive, Salt Lake City, UT, USA; Department of Ophthalmology & Visual Sciences, University of Utah, 65 Mario Capecchi Drive, Salt Lake City, UT, USA.
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23
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Du H, Xiao X, Stiles T, Douglas C, Ho D, Shaw PX. Novel Mechanistic Interplay between Products of Oxidative Stress and Components of the Complement System in AMD Pathogenesis. ACTA ACUST UNITED AC 2016; 6:43-50. [PMID: 27668132 PMCID: PMC5035113 DOI: 10.4236/ojoph.2016.61006] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Age-related macular degeneration (AMD) is a leading cause of vision loss affecting tens of millions of elderly worldwide. Early AMD includes soft drusen and pigmentary changes in the retinal pigment epithelium (RPE). As people age, such soft confluent drusen can progress into two forms of advanced AMD, geographic atrophy (GA, or dry AMD) or choroidal neovascularization (CNV, or wet AMD) and result in the loss of central vision. The exact mechanism for developing early AMD and progressing to advanced stage of disease is still largely unknown. However, significant evidence exists demonstrating a complex interplay of genetic and environmental factors as the cause of AMD progression. Together, complement factor H (CFH) and HTRA1/ARMS polymorphisms contribute to more than 50% of the genetic risk for AMD. Environmentally, oxidative stress from activities such as smoking has also demonstrated a powerful contribution to AMD progression. To extend our previous finding that genetic polymorphisms in CFH results in OxPLs and the risk-form of CFH (CFH Y402H) has reduced affinity for oxidized phospholipids, and subsequent diminished capacity which subsequently diminishes the capability to attenuate the inflammatory effects of these molecules, we compared the binding properties of CFH and CFH related protein 1 (CFHR1), which is also associated with disease risk, to OxPLs and their effects on modulating inflammation and lipids uptake. As both CFH-402H and CFHR1 are associated with increased risk to AMD, we hypothesized that like CFH-402H, CFHR1 contribution to AMD risk may also be due to its diminished affinity for OxPLs. Interestingly, we found that association of CFHR1 with OxPLs was not statistically different than CFH. However, binding of CFHR1 did not elicit the same protective benefits as CFH in that both inflammation and lipid uptake are unaffected by CFHR1 association with OxPLs. These findings demonstrate a novel and interesting complexity to the potential interplay between the complement system and oxidative stress byproducts, such as OxPLs, in the mechanistic contribution to AMD. Future work will aim to identify the molecular distinctions between CFH and CFHR1 which confer protection by the former, but not latter molecules. Understanding the molecular domains necessary for protection could provide interventional insights in the generation of novel therapeutics for AMD and other diseases associated with oxidative stress.
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Affiliation(s)
- Hongjun Du
- Department of Ophthalmology, Xijing Hospital, Xi'an, China; Department of Ophthalmology and Shiley Eye Institute, University of California San Diego, San Diego, USA
| | - Xu Xiao
- Sichuan Provincial People's Hospital, Chengdu, China
| | - Travis Stiles
- Department of Ophthalmology and Shiley Eye Institute, University of California San Diego, San Diego, USA
| | - Christopher Douglas
- Department of Ophthalmology and Shiley Eye Institute, University of California San Diego, San Diego, USA
| | - Daisy Ho
- Department of Ophthalmology and Shiley Eye Institute, University of California San Diego, San Diego, USA
| | - Peter X Shaw
- Department of Ophthalmology and Shiley Eye Institute, University of California San Diego, San Diego, USA
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