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Donato L, Mordà D, Scimone C, Alibrandi S, D’Angelo R, Sidoti A. Bridging Retinal and Cerebral Neurodegeneration: A Focus on Crosslinks between Alzheimer-Perusini's Disease and Retinal Dystrophies. Biomedicines 2023; 11:3258. [PMID: 38137479 PMCID: PMC10741418 DOI: 10.3390/biomedicines11123258] [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: 11/01/2023] [Revised: 12/02/2023] [Accepted: 12/07/2023] [Indexed: 12/24/2023] Open
Abstract
In the early stages of Alzheimer-Perusini's disease (AD), individuals often experience vision-related issues such as color vision impairment, reduced contrast sensitivity, and visual acuity problems. As the disease progresses, there is a connection with glaucoma and age-related macular degeneration (AMD) leading to retinal cell death. The retina's involvement suggests a link with the hippocampus, where most AD forms start. A thinning of the retinal nerve fiber layer (RNFL) due to the loss of retinal ganglion cells (RGCs) is seen as a potential AD diagnostic marker using electroretinography (ERG) and optical coherence tomography (OCT). Amyloid beta fragments (Aβ), found in the eye's vitreous and aqueous humor, are also present in the cerebrospinal fluid (CSF) and accumulate in the retina. Aβ is known to cause tau hyperphosphorylation, leading to its buildup in various retinal layers. However, diseases like AD are now seen as mixed proteinopathies, with deposits of the prion protein (PrP) and α-synuclein found in affected brains and retinas. Glial cells, especially microglial cells, play a crucial role in these diseases, maintaining immunoproteostasis. Studies have shown similarities between retinal and brain microglia in terms of transcription factor expression and morphotypes. All these findings constitute a good start to achieving better comprehension of neurodegeneration in both the eye and the brain. New insights will be able to bring the scientific community closer to specific disease-modifying therapies.
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Affiliation(s)
- Luigi Donato
- Department of Biomedical and Dental Sciences and Morphofunctional Imaging, Division of Medical Biotechnologies and Preventive Medicine, University of Messina, 98122 Messina, Italy; (L.D.); (C.S.); (R.D.); (A.S.)
- Department of Biomolecular Strategies, Genetics, Cutting-Edge Therapies, Euro-Mediterranean Institute of Science and Technology (I.E.ME.S.T.), 90139 Palermo, Italy;
| | - Domenico Mordà
- Department of Biomolecular Strategies, Genetics, Cutting-Edge Therapies, Euro-Mediterranean Institute of Science and Technology (I.E.ME.S.T.), 90139 Palermo, Italy;
- Department of Veterinary Sciences, University of Messina, 98122 Messina, Italy
| | - Concetta Scimone
- Department of Biomedical and Dental Sciences and Morphofunctional Imaging, Division of Medical Biotechnologies and Preventive Medicine, University of Messina, 98122 Messina, Italy; (L.D.); (C.S.); (R.D.); (A.S.)
- Department of Biomolecular Strategies, Genetics, Cutting-Edge Therapies, Euro-Mediterranean Institute of Science and Technology (I.E.ME.S.T.), 90139 Palermo, Italy;
| | - Simona Alibrandi
- Department of Biomedical and Dental Sciences and Morphofunctional Imaging, Division of Medical Biotechnologies and Preventive Medicine, University of Messina, 98122 Messina, Italy; (L.D.); (C.S.); (R.D.); (A.S.)
- Department of Biomolecular Strategies, Genetics, Cutting-Edge Therapies, Euro-Mediterranean Institute of Science and Technology (I.E.ME.S.T.), 90139 Palermo, Italy;
| | - Rosalia D’Angelo
- Department of Biomedical and Dental Sciences and Morphofunctional Imaging, Division of Medical Biotechnologies and Preventive Medicine, University of Messina, 98122 Messina, Italy; (L.D.); (C.S.); (R.D.); (A.S.)
| | - Antonina Sidoti
- Department of Biomedical and Dental Sciences and Morphofunctional Imaging, Division of Medical Biotechnologies and Preventive Medicine, University of Messina, 98122 Messina, Italy; (L.D.); (C.S.); (R.D.); (A.S.)
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García-Bermúdez MY, Vohra R, Freude K, van Wijngaarden P, Martin K, Thomsen MS, Aldana BI, Kolko M. Potential Retinal Biomarkers in Alzheimer's Disease. Int J Mol Sci 2023; 24:15834. [PMID: 37958816 PMCID: PMC10649108 DOI: 10.3390/ijms242115834] [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: 09/01/2023] [Revised: 10/18/2023] [Accepted: 10/25/2023] [Indexed: 11/15/2023] Open
Abstract
Alzheimer's disease (AD) represents a major diagnostic challenge, as early detection is crucial for effective intervention. This review examines the diagnostic challenges facing current AD evaluations and explores the emerging field of retinal alterations as early indicators. Recognizing the potential of the retina as a noninvasive window to the brain, we emphasize the importance of identifying retinal biomarkers in the early stages of AD. However, the examination of AD is not without its challenges, as the similarities shared with other retinal diseases introduce complexity in the search for AD-specific markers. In this review, we address the relevance of using the retina for the early diagnosis of AD and the complex challenges associated with the search for AD-specific retinal biomarkers. We provide a comprehensive overview of the current landscape and highlight avenues for progress in AD diagnosis by retinal examination.
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Affiliation(s)
| | - Rupali Vohra
- Eye Translational Research Unit, Department of Drug Design and Pharmacology, University of Copenhagen, 2100 Copenhagen, Denmark
- Department of Ophthalmology, Copenhagen University Hospital, Rigshospitalet, 2600 Glostrup, Denmark
| | - Kristine Freude
- Group of Stem Cell Models and Embryology, Department of Veterinary and Animal Sciences, University of Copenhagen, 1870 Frederiksberg, Denmark
| | - Peter van Wijngaarden
- Center for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, VIC 3002, Australia
- Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, VIC 3010, Australia
| | - Keith Martin
- Center for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, VIC 3002, Australia
- Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, VIC 3010, Australia
- Department of Clinical Neurosciences, University of Cambridge, Cambridge CB2 0QQ, UK
| | - Maj Schneider Thomsen
- Neurobiology Research and Drug Delivery, Department of Health, Science and Technology, Aalborg University, 9220 Aalborg, Denmark
| | - Blanca Irene Aldana
- Neurometabolism Research Group, Department of Drug Design and Pharmacology, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Miriam Kolko
- Eye Translational Research Unit, Department of Drug Design and Pharmacology, University of Copenhagen, 2100 Copenhagen, Denmark
- Department of Ophthalmology, Copenhagen University Hospital, Rigshospitalet, 2600 Glostrup, Denmark
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Maran JJ, Adesina MM, Green CR, Kwakowsky A, Mugisho OO. The central role of the NLRP3 inflammasome pathway in the pathogenesis of age-related diseases in the eye and the brain. Ageing Res Rev 2023; 88:101954. [PMID: 37187367 DOI: 10.1016/j.arr.2023.101954] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 05/08/2023] [Accepted: 05/12/2023] [Indexed: 05/17/2023]
Abstract
With increasing age, structural changes occur in the eye and brain. Neuronal death, inflammation, vascular disruption, and microglial activation are among many of the pathological changes that can occur during ageing. Furthermore, ageing individuals are at increased risk of developing neurodegenerative diseases in these organs, including Alzheimer's disease (AD), Parkinson's disease (PD), glaucoma and age-related macular degeneration (AMD). Although these diseases pose a significant global public health burden, current treatment options focus on slowing disease progression and symptomatic control rather than targeting underlying causes. Interestingly, recent investigations have proposed an analogous aetiology between age-related diseases in the eye and brain, where a process of chronic low-grade inflammation is implicated. Studies have suggested that patients with AD or PD are also associated with an increased risk of AMD, glaucoma, and cataracts. Moreover, pathognomonic amyloid-β and α-synuclein aggregates, which accumulate in AD and PD, respectively, can be found in ocular parenchyma. In terms of a common molecular pathway that underpins these diseases, the nucleotide-binding domain, leucine-rich-containing family, and pyrin domain-containing-3 (NLRP3) inflammasome is thought to play a vital role in the manifestation of all these diseases. This review summarises the current evidence regarding cellular and molecular changes in the brain and eye with age, similarities between ocular and cerebral age-related diseases, and the role of the NLRP3 inflammasome as a critical mediator of disease propagation in the eye and the brain during ageing.
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Affiliation(s)
- Jack J Maran
- Buchanan Ocular Therapeutics Unit, Department of Ophthalmology and the New Zealand National Eye Centre, University of Auckland, New Zealand
| | - Moradeke M Adesina
- Buchanan Ocular Therapeutics Unit, Department of Ophthalmology and the New Zealand National Eye Centre, University of Auckland, New Zealand
| | - Colin R Green
- Department of Ophthalmology and the New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, New Zealand
| | - Andrea Kwakowsky
- Pharmacology and Therapeutics, School of Medicine, Galway Neuroscience Centre, University of Galway, Galway, Ireland
| | - Odunayo O Mugisho
- Buchanan Ocular Therapeutics Unit, Department of Ophthalmology and the New Zealand National Eye Centre, University of Auckland, New Zealand.
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Vig V, Garg I, Tuz-Zahra F, Xu J, Tripodis Y, Nicks R, Xia W, Alvarez VE, Alosco ML, Stein TD, Subramanian ML. Vitreous Humor Biomarkers Reflect Pathological Changes in the Brain for Alzheimer's Disease and Chronic Traumatic Encephalopathy. J Alzheimers Dis 2023:JAD230167. [PMID: 37182888 DOI: 10.3233/jad-230167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
BACKGROUND Patients with eye disease have an increased risk for developing neurodegenerative disease. Neurodegenerative proteins can be measured in the eye; however, correlations between biomarker levels in eye fluid and neuropathological diagnoses have not been established. OBJECTIVE This exploratory, retrospective study examined vitreous humor from 41 postmortem eyes and brain tissue with neuropathological diagnoses of Alzheimer's disease (AD, n = 7), chronic traumatic encephalopathy (CTE, n = 15), both AD + CTE (n = 10), and without significant neuropathology (controls, n = 9). METHODS Protein biomarkers i.e., amyloid-β (Aβ 40,42), total tau (tTau), phosphorylated tau (pTau181,231), neurofilament light chain (NfL), and eotaxin-1 were quantitatively measured by immunoassay. Non-parametric tests were used to compare vitreous biomarker levels between groups. Spearman's rank correlation tests were used to correlate biomarker levels in vitreous and cortical tissue. The level of significance was set to α= 0.10. RESULTS In pairwise comparisons, tTau levels were significantly increased in AD and CTE groups versus controls (p = 0.08 for both) as well as AD versus AD+CTE group and CTE versus AD+CTE group (p = 0.049 for both). Vitreous NfL levels were significantly increased in low CTE (Stage I/II) versus no CTE (p = 0.096) and in low CTE versus high CTE stage (p = 0.03). Vitreous and cortical tissue levels of pTau 231 (p = 0.02, r = 0.38) and t-Tau (p = 0.04, r = -0.34) were significantly correlated. CONCLUSION The postmortem vitreous humor biomarker levels significantly correlate with AD and CTE pathology in corresponding brains, while vitreous NfL was correlated with the CTE staging. This exploratory study indicates that biomarkers in the vitreous humor may serve as a proxy for neuropathological disease.
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Affiliation(s)
- Viha Vig
- Department of Ophthalmology, Boston Medical Center, Boston University School of Medicine, Boston, MA, USA
| | - Itika Garg
- Department of Ophthalmology, Tulane University School of Medicine, New Orleans, LA, USA
| | - Fatima Tuz-Zahra
- Department of Biostatistics, Boston University School of Public Health, Boston, MA, USA
| | - Jia Xu
- Department of Ophthalmology, Boston Medical Center, Boston University School of Medicine, Boston, MA, USA
| | - Yorghos Tripodis
- Department of Biostatistics, Boston University School of Public Health, Boston, MA, USA
| | - Raymond Nicks
- Boston University Alzheimer's Disease Research Center and CTE Center, Boston University Chobanian & Avedisian School of Medicine, Boston, MA, USA
| | - Weiming Xia
- Department of Pharmacology and Experimental Therapeutics, Boston University School of Medicine, Boston, MA, USA
- Geriatric Research Education and Clinical Center, Bedford Veterans Affairs Medical Center, Bedford, MA, USA
| | - Victor E Alvarez
- Boston University Alzheimer's Disease Research Center and CTE Center, Boston University Chobanian & Avedisian School of Medicine, Boston, MA, USA
- Department of Pathology and Laboratory Medicine, Boston Medical Center, Boston University School of Medicine, Boston, MA USA
- VA Bedford Healthcare System, Bedford, MA, USA
- VA Boston Healthcare System, Boston, MA, USA
| | - Michael L Alosco
- Boston University Alzheimer's Disease Research Center and CTE Center, Boston University Chobanian & Avedisian School of Medicine, Boston, MA, USA
| | - Thor D Stein
- Boston University Alzheimer's Disease Research Center and CTE Center, Boston University Chobanian & Avedisian School of Medicine, Boston, MA, USA
- Department of Pathology and Laboratory Medicine, Boston Medical Center, Boston University School of Medicine, Boston, MA USA
- VA Bedford Healthcare System, Bedford, MA, USA
- VA Boston Healthcare System, Boston, MA, USA
| | - Manju L Subramanian
- Department of Ophthalmology, Boston Medical Center, Boston University School of Medicine, Boston, MA, USA
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Hussain A, Sheikh Z, Subramanian M. The Eye as a Diagnostic Tool for Alzheimer’s Disease. Life (Basel) 2023; 13:life13030726. [PMID: 36983883 PMCID: PMC10052959 DOI: 10.3390/life13030726] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2023] [Revised: 02/23/2023] [Accepted: 03/04/2023] [Indexed: 03/10/2023] Open
Abstract
Alzheimer’s disease (AD) is a progressive neurodegenerative disorder impacting cognition, function, and behavior in the elderly population. While there are currently no disease-modifying agents capable of curing AD, early diagnosis and management in the preclinical stage can significantly improve patient morbidity and life expectancy. Currently, the diagnosis of Alzheimer’s disease is a clinical one, often supplemented by invasive and expensive biomarker testing. Over the last decade, significant advancements have been made in our understanding of AD and the role of ocular tissue as a potential biomarker. Ocular biomarkers hold the potential to provide noninvasive and easily accessible diagnostic and monitoring capabilities. This review summarizes current research for detecting biomarkers of Alzheimer’s disease in ocular tissue.
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Prasad M, Xu J, Agranat JS, Xia W, Daley S, Ness S, Chen X, Siegel NH, Stein TD, Chung J, Subramanian ML. Upregulation of Neuroinflammatory Protein Biomarkers in Acute Rhegmatogenous Retinal Detachments. LIFE (BASEL, SWITZERLAND) 2022; 13:life13010118. [PMID: 36676067 PMCID: PMC9862737 DOI: 10.3390/life13010118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 12/20/2022] [Accepted: 12/26/2022] [Indexed: 01/04/2023]
Abstract
The purpose of this study is to characterize the inflammatory cytokine profile in rhegmatogenous retinal detachments (RRDs) compared to surgical controls. Vitreous humor was collected from patients undergoing vitrectomy for RRD and noninflammatory vitreoretinal diseases. A quantitative immunoassay was used to measure the levels of 36 cytokine markers. Linear regression analysis with the duration of detachment as the predictor and log-transformed cytokine levels as the outcome was conducted for normally distributed cytokines as determined by the Shapiro-Wilk test. The analysis was adjusted for age, sex, and race. The Kruskal-Wallis test was used for cytokines not normally distributed. Twenty-seven RRD cases and thirteen control cases were studied. Between all RRDs and controls, fibroblast growth factor 2 (FGF2) (p = 0.0029), inducible protein-10(IP-10) (p = 0.0021), monocyte chemoattractant protein-1 (MCP-1) (p = 0.0040), interleukin (IL)-16 (p = 0.018), IL-8 (p = 0.0148), IL-6 (p = 0.0071), eotaxin (p = 0.0323), macrophage inflammatory protein (MIP)-1 alpha (p = 0.0149), MIP-1 beta (p = 0.0032), and the thymus and activation regulated cytokine (TARC) (p = 0.0121) were elevated in RRD cases. Between acute RRDs (n = 16) and controls, FGF2 (p = 0.0001), IP10 (p = 0.0027), MCP-1 (p = 0.0015), MIP-1β (p = 0.0004), IL-8 (p = 0.0146), and IL-6 (p = 0.0031) were elevated. Determining alterations in inflammatory cytokine profiles may aid in understanding their impact on RRD development, clinical course, and complications before and after surgical repair.
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Affiliation(s)
- Minali Prasad
- Department of Ophthalmology, Boston University School of Medicine & Boston Medical Center, Boston, MA 02118, USA
| | - Jia Xu
- Department of Ophthalmology, Boston University School of Medicine & Boston Medical Center, Boston, MA 02118, USA
| | - Joshua S. Agranat
- Department of Ophthalmology, Boston University School of Medicine & Boston Medical Center, Boston, MA 02118, USA
| | - Weiming Xia
- Department of Pharmacology and Experimental Therapeutics, Boston University School of Medicine, 72 East Concord Street, Boston, MA 02118, USA
- Geriatric Research Education and Clinical Center, VA Bedford Healthcare System, Bedford, MA 01730, USA
| | - Sarah Daley
- Department of Pharmacology and Experimental Therapeutics, Boston University School of Medicine, 72 East Concord Street, Boston, MA 02118, USA
- Geriatric Research Education and Clinical Center, VA Bedford Healthcare System, Bedford, MA 01730, USA
| | - Steven Ness
- Department of Ophthalmology, Boston University School of Medicine & Boston Medical Center, Boston, MA 02118, USA
| | - Xuejing Chen
- Department of Ophthalmology, Boston University School of Medicine & Boston Medical Center, Boston, MA 02118, USA
| | - Nicole H. Siegel
- Department of Ophthalmology, Boston University School of Medicine & Boston Medical Center, Boston, MA 02118, USA
| | - Thor D. Stein
- Laboratory Medicine, Department of Pathology, Boston University School of Medicine, Boston, MA 02118, USA
- VA Bedford Healthcare System, Bedford, MA 01730, USA
- VA Boston Healthcare System, Boston, MA 02130, USA
| | - Jaeyoon Chung
- Department of Medicine (Biomedical Genetics), Boston University School of Medicine, 72 East Concord Street, Boston, MA 02118, USA
| | - Manju L. Subramanian
- Department of Ophthalmology, Boston University School of Medicine & Boston Medical Center, Boston, MA 02118, USA
- Correspondence: ; Tel.: +617-414-2020
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Lynn SA, Soubigou F, Dewing JM, Smith A, Ballingall J, Sass T, Nica I, Watkins C, Gupta B, Almuhtaseb H, Lash SC, Yuen HM, Cree A, Newman TA, Lotery AJ, Ratnayaka JA. An Exploratory Study Provides Insights into MMP9 and Aβ Levels in the Vitreous and Blood across Different Ages and in a Subset of AMD Patients. Int J Mol Sci 2022; 23:ijms232314603. [PMID: 36498929 PMCID: PMC9736887 DOI: 10.3390/ijms232314603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 11/15/2022] [Accepted: 11/18/2022] [Indexed: 11/24/2022] Open
Abstract
Matrix metalloproteinase-9 (MMP9) and total amyloid-beta (Aβ) are prospective biomarkers of ocular ageing and retinopathy. These were quantified by ELISA in the vitreous and blood from controls (n = 55) and in a subset of age-related macular degeneration (AMD) patients (n = 12) for insights and possible additional links between the ocular and systemic compartments. Vitreous MMP9 levels in control and AMD groups were 932.5 ± 240.9 pg/mL and 813.7 ± 157.6 pg/mL, whilst serum levels were 2228 ± 193 pg/mL and 2386.8 ± 449.4 pg/mL, respectively. Vitreous Aβ in control and AMD groups were 1173.5 ± 117.1 pg/mL and 1275.6 ± 332.9 pg/mL, whilst plasma Aβ were 574.3 ± 104.8 pg/mL and 542.2 ± 139.9 pg/mL, respectively. MMP9 and Aβ showed variable levels across the lifecourse, indicating no correlation to each other or with age nor AMD status, though the smaller AMD cohort was a limiting factor. Aβ and MMP9 levels in the vitreous and blood were unrelated to mean arterial pressure. Smoking, another modifiable risk, showed no association with vitreous Aβ. However, smoking may be linked with vitreous (p = 0.004) and serum (p = 0.005) MMP9 levels in control and AMD groups, though this did not reach our elevated (p = 0.001) significance. A bioinformatics analysis revealed promising MMP9 and APP/Aβ partners for further scrutiny, many of which are already linked with retinopathy.
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Affiliation(s)
- Savannah A. Lynn
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, MP806, Tremona Road, Southampton SO16 6YD, UK
| | - Flavie Soubigou
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, MP806, Tremona Road, Southampton SO16 6YD, UK
| | - Jennifer M. Dewing
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, MP806, Tremona Road, Southampton SO16 6YD, UK
| | - Amanda Smith
- Eye Unit, University Hospital Southampton NHS Foundation Trust, Southampton SO16 6YD, UK
| | - Joanna Ballingall
- Eye Unit, University Hospital Southampton NHS Foundation Trust, Southampton SO16 6YD, UK
| | - Thea Sass
- Eye Unit, University Hospital Southampton NHS Foundation Trust, Southampton SO16 6YD, UK
| | - Isabela Nica
- Eye Unit, University Hospital Southampton NHS Foundation Trust, Southampton SO16 6YD, UK
| | - Catrin Watkins
- Eye Unit, University Hospital Southampton NHS Foundation Trust, Southampton SO16 6YD, UK
| | - Bhaskar Gupta
- Eye Unit, University Hospital Southampton NHS Foundation Trust, Southampton SO16 6YD, UK
| | - Hussein Almuhtaseb
- Eye Unit, University Hospital Southampton NHS Foundation Trust, Southampton SO16 6YD, UK
| | - Stephen C. Lash
- Eye Unit, University Hospital Southampton NHS Foundation Trust, Southampton SO16 6YD, UK
| | - Ho Ming Yuen
- Primary Care, Population Sciences and Medical Education, Faculty of Medicine, University of Southampton, MP 801, Tremona Road, Southampton SO16 6YD, UK
| | - Angela Cree
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, MP806, Tremona Road, Southampton SO16 6YD, UK
| | - Tracey A. Newman
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, MP806, Tremona Road, Southampton SO16 6YD, UK
| | - Andrew J. Lotery
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, MP806, Tremona Road, Southampton SO16 6YD, UK
- Eye Unit, University Hospital Southampton NHS Foundation Trust, Southampton SO16 6YD, UK
- Correspondence: (A.J.L.); (J.A.R.)
| | - J. Arjuna Ratnayaka
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, MP806, Tremona Road, Southampton SO16 6YD, UK
- Correspondence: (A.J.L.); (J.A.R.)
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Moncaster JA, Moir RD, Burton MA, Chadwick O, Minaeva O, Alvarez VE, Ericsson M, Clark JI, McKee AC, Tanzi RE, Goldstein LE. Alzheimer's disease amyloid-β pathology in the lens of the eye. Exp Eye Res 2022; 221:108974. [PMID: 35202705 PMCID: PMC9873124 DOI: 10.1016/j.exer.2022.108974] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Revised: 01/31/2022] [Accepted: 02/02/2022] [Indexed: 01/26/2023]
Abstract
Neuropathological hallmarks of Alzheimer's disease (AD) include pathogenic accumulation of amyloid-β (Aβ) peptides and age-dependent formation of amyloid plaques in the brain. AD-associated Aβ neuropathology begins decades before onset of cognitive symptoms and slowly progresses over the course of the disease. We previously reported discovery of Aβ deposition, β-amyloidopathy, and co-localizing supranuclear cataracts (SNC) in lenses from people with AD, but not other neurodegenerative disorders or normal aging. We confirmed AD-associated Aβ molecular pathology in the lens by immunohistopathology, amyloid histochemistry, immunoblot analysis, epitope mapping, immunogold electron microscopy, quantitative immunoassays, and tryptic digest mass spectrometry peptide sequencing. Ultrastructural analysis revealed that AD-associated Aβ deposits in AD lenses localize as electron-dense microaggregates in the cytoplasm of supranuclear (deep cortex) fiber cells. These Aβ microaggregates also contain αB-crystallin and scatter light, thus linking Aβ pathology and SNC phenotype expression in the lenses of people with AD. Subsequent research identified Aβ lens pathology as the molecular origin of the distinctive cataracts associated with Down syndrome (DS, trisomy 21), a chromosomal disorder invariantly associated with early-onset Aβ accumulation and Aβ amyloidopathy in the brain. Investigation of 1249 participants in the Framingham Eye Study found that AD-associated quantitative traits in brain and lens are co-heritable. Moreover, AD-associated lens traits preceded MRI brain traits and cognitive deficits by a decade or more and predicted future AD. A genome-wide association study of bivariate outcomes in the same subjects identified a new AD risk factor locus in the CTNND2 gene encoding δ-catenin, a protein that modulates Aβ production in brain and lens. Here we report identification of AD-related human Aβ (hAβ) lens pathology and age-dependent SNC phenotype expression in the Tg2576 transgenic mouse model of AD. Tg2576 mice express Swedish mutant human amyloid precursor protein (APP-Swe), accumulate hAβ peptides and amyloid pathology in the brain, and exhibit cognitive deficits that slowly progress with increasing age. We found that Tg2576 trangenic (Tg+) mice, but not non-transgenic (Tg-) control mice, also express human APP, accumulate hAβ peptides, and develop hAβ molecular and ultrastructural pathologies in the lens. Tg2576 Tg+ mice exhibit age-dependent Aβ supranuclear lens opacification that recapitulates lens pathology and SNC phenotype expression in human AD. In addition, we detected hAβ in conditioned medium from lens explant cultures prepared from Tg+ mice, but not Tg- control mice, a finding consistent with constitutive hAβ generation in the lens. In vitro studies showed that hAβ promoted mouse lens protein aggregation detected by quasi-elastic light scattering (QLS) spectroscopy. These results support mechanistic (genotype-phenotype) linkage between Aβ pathology and AD-related phenotypes in lens and brain. Collectively, our findings identify Aβ pathology as the shared molecular etiology of two age-dependent AD-related cataracts associated with two human diseases (AD, DS) and homologous murine cataracts in the Tg2576 transgenic mouse model of AD. These results represent the first evidence of AD-related Aβ pathology outside the brain and point to lens Aβ as an optically-accessible AD biomarker for early detection and longitudinal monitoring of this devastating neurodegenerative disease.
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Affiliation(s)
- Juliet A. Moncaster
- Molecular Aging and Development Laboratory, Boston University School of Medicine, Boston, MA, 02118, USA,Boston University Alzheimer’s Disease Research Center, Boston University School of Medicine, 72 East Concord Street, B-7800 Boston, MA, 02118, USA
| | - Robert D. Moir
- Genetics and Aging Research Unit, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, 02129, USA
| | - Mark A. Burton
- Molecular Aging and Development Laboratory, Boston University School of Medicine, Boston, MA, 02118, USA
| | - Oliver Chadwick
- Genetics and Aging Research Unit, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, 02129, USA
| | - Olga Minaeva
- Molecular Aging and Development Laboratory, Boston University School of Medicine, Boston, MA, 02118, USA,Boston University Alzheimer’s Disease Research Center, Boston University School of Medicine, 72 East Concord Street, B-7800 Boston, MA, 02118, USA
| | - Victor E. Alvarez
- Boston University Alzheimer’s Disease Research Center, Boston University School of Medicine, 72 East Concord Street, B-7800 Boston, MA, 02118, USA,Edith Nourse Rogers Memorial Veterans’ Hospital, Bedford, MA, 01730, USA
| | - Maria Ericsson
- Electron Microscopy Facility, Harvard Medical School, Boston, MA, 02115, USA
| | - John I. Clark
- Departments of Biological Structure and Ophthalmology, University of Washington, Seattle, WA, 98195, USA
| | - Ann C. McKee
- Boston University Alzheimer’s Disease Research Center, Boston University School of Medicine, 72 East Concord Street, B-7800 Boston, MA, 02118, USA,Edith Nourse Rogers Memorial Veterans’ Hospital, Bedford, MA, 01730, USA
| | - Rudolph E. Tanzi
- Genetics and Aging Research Unit, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, 02129, USA
| | - Lee E. Goldstein
- Molecular Aging and Development Laboratory, Boston University School of Medicine, Boston, MA, 02118, USA,Boston University Alzheimer’s Disease Research Center, Boston University School of Medicine, 72 East Concord Street, B-7800 Boston, MA, 02118, USA,Corresponding author. Molecular Aging & Development Laboratory, Boston University, School of Medicine, 670 Albany Street, Boston, MA, 02118, USA. (L.E. Goldstein)
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9
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Kirchler M, Konigorski S, Norden M, Meltendorf C, Kloft M, Schurmann C, Lippert C. transferGWAS: GWAS of images using deep transfer learning. Bioinformatics 2022; 38:3621-3628. [PMID: 35640976 DOI: 10.1093/bioinformatics/btac369] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 05/05/2022] [Accepted: 05/26/2022] [Indexed: 11/13/2022] Open
Abstract
MOTIVATION Medical images can provide rich information about diseases and their biology. However, investigating their association with genetic variation requires non-standard methods. We propose transferGWAS, a novel approach to perform genome-wide association studies directly on full medical images. First, we learn semantically meaningful representations of the images based on a transfer learning task, during which a deep neural network is trained on independent but similar data. Then, we perform genetic association tests with these representations. RESULTS We validate the type I error rates and power of transferGWAS in simulation studies of synthetic images. Then we apply transferGWAS in a genome-wide association study of retinal fundus images from the UK Biobank. This first-of-a-kind GWAS of full imaging data yielded 60 genomic regions associated with retinal fundus images, of which 7 are novel candidate loci for eye-related traits and diseases. AVAILABILITY AND IMPLEMENTATION Our method is implemented in Python and available at https://github.com/mkirchler/transferGWAS/. SUPPLEMENTARY INFORMATION Supplementary data are available at Bioinformatics online.
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Affiliation(s)
- Matthias Kirchler
- Digital Health-Machine Learning Research Group, Digital Health Center, Hasso Plattner Institute, University of Potsdam, 14482 Potsdam, Germany.,Department of Computer Science, TU Kaiserslautern, 67663 Kaiserslautern, Germany
| | - Stefan Konigorski
- Digital Health-Machine Learning Research Group, Digital Health Center, Hasso Plattner Institute, University of Potsdam, 14482 Potsdam, Germany.,Hasso Plattner Institute for Digital Health at Mount Sinai, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Matthias Norden
- Digital Health & Personalized Medicine Research Group, Digital Health Center, Hasso Plattner Institute, University of Potsdam, 14482 Potsdam, Germany.,Department of Anesthesiology and Intensive Care Medicine, Charité-Universitätsmedizin Berlin, 10117 Berlin, Germany
| | - Christian Meltendorf
- Department of Electrical Engineering - Mechatronics - Optometry, Beuth University of Applied Sciences Berlin, 13353 Berlin, Germany
| | - Marius Kloft
- Department of Computer Science, TU Kaiserslautern, 67663 Kaiserslautern, Germany
| | - Claudia Schurmann
- Hasso Plattner Institute for Digital Health at Mount Sinai, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.,Digital Health & Personalized Medicine Research Group, Digital Health Center, Hasso Plattner Institute, University of Potsdam, 14482 Potsdam, Germany
| | - Christoph Lippert
- Digital Health-Machine Learning Research Group, Digital Health Center, Hasso Plattner Institute, University of Potsdam, 14482 Potsdam, Germany.,Hasso Plattner Institute for Digital Health at Mount Sinai, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
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10
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Alzheimer's Disease Seen through the Eye: Ocular Alterations and Neurodegeneration. Int J Mol Sci 2022; 23:ijms23052486. [PMID: 35269629 PMCID: PMC8910735 DOI: 10.3390/ijms23052486] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 02/21/2022] [Accepted: 02/22/2022] [Indexed: 12/18/2022] Open
Abstract
Alzheimer’s Disease (AD) is one of the main neurodegenerative diseases worldwide. Unfortunately, AD shares many similarities with other dementias at early stages, which impedes an accurate premortem diagnosis. Therefore, it is urgent to find biomarkers to allow for early diagnosis of the disease. There is increasing scientific evidence highlighting the similarities between the eye and other structures of the CNS, suggesting that knowledge acquired in eye research could be useful for research and diagnosis of AD. For example, the retina and optic nerve are considered part of the central nervous system, and their damage can result in retrograde and anterograde axon degeneration, as well as abnormal protein aggregation. In the anterior eye segment, the aqueous humor and tear film may be comparable to the cerebrospinal fluid. Both fluids are enriched with molecules that can be potential neurodegenerative biomarkers. Indeed, the pathophysiology of AD, characterized by cerebral deposits of amyloid-beta (Aβ) and tau protein, is also present in the eyes of AD patients, besides numerous structural and functional changes observed in the structure of the eyes. Therefore, all this evidence suggests that ocular changes have the potential to be used as either predictive values for AD assessment or as diagnostic tools.
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11
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Abstract
There has been increasing interest in finding non-invasive biomarkers for neurodegenerative diseases such as Alzheimer's disease (AD). This observational study investigated AD-specific biomarkers in tear fluid. Tear fluid was collected from a total of 65 subjects, including 23 patients with subjective cognitive decline (SCD), 22 patients with mild cognitive impairment (MCI), 11 dementia patients and 9 healthy controls (HC). Levels of amyloid-beta peptides (AB38, AB40, AB42), total-tau (t-tau) and phosphorylated-tau (p-tau) were determined using multiplex immunoassays. Levels of AB40 and t-tau were detectable in the vast majority (> 94%) of tear fluid samples. Cerebrospinal fluid (CSF) was available from a subset of patients. In this group, tear t-tau levels were significantly higher in people with dementia compared to SCD patients. Tear t-tau levels were elevated in patients with neurodegeneration (classified according to the A/T/N system) compared to patients without neurodegeneration. Negative correlations were found between CSF AB42 and CSF t-tau, and between CSF AB42 and tear t-tau. In summary, this study shows the potential of tau proteins in tear fluid to be associated with disease severity and neurodegeneration.
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12
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Gijs M, Ramakers IHGB, Visser PJ, Verhey FRJ, van de Waarenburg MPH, Schalkwijk CG, Nuijts RMMA, Webers CAB. Association of tear fluid amyloid and tau levels with disease severity and neurodegeneration. Sci Rep 2021; 11:22675. [PMID: 34811435 PMCID: PMC8608861 DOI: 10.1038/s41598-021-01993-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Accepted: 11/08/2021] [Indexed: 02/07/2023] Open
Abstract
There has been increasing interest in finding non-invasive biomarkers for neurodegenerative diseases such as Alzheimer's disease (AD). This observational study investigated AD-specific biomarkers in tear fluid. Tear fluid was collected from a total of 65 subjects, including 23 patients with subjective cognitive decline (SCD), 22 patients with mild cognitive impairment (MCI), 11 dementia patients and 9 healthy controls (HC). Levels of amyloid-beta peptides (AB38, AB40, AB42), total-tau (t-tau) and phosphorylated-tau (p-tau) were determined using multiplex immunoassays. Levels of AB40 and t-tau were detectable in the vast majority (> 94%) of tear fluid samples. Cerebrospinal fluid (CSF) was available from a subset of patients. In this group, tear t-tau levels were significantly higher in people with dementia compared to SCD patients. Tear t-tau levels were elevated in patients with neurodegeneration (classified according to the A/T/N system) compared to patients without neurodegeneration. Negative correlations were found between CSF AB42 and CSF t-tau, and between CSF AB42 and tear t-tau. In summary, this study shows the potential of tau proteins in tear fluid to be associated with disease severity and neurodegeneration.
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Affiliation(s)
- Marlies Gijs
- University Eye Clinic Maastricht, Maastricht University Medical Center (MUMC+), School for Mental Health and Neuroscience, Maastricht University, P. Debyelaan 25, 6229 HX, Maastricht, The Netherlands.
| | - Inez H G B Ramakers
- Department of Psychiatry and Neuropsychology, Alzheimer Center Limburg, School for Mental Health and Neuroscience, Maastricht University, Maastricht, The Netherlands
| | - Pieter Jelle Visser
- Department of Psychiatry and Neuropsychology, Alzheimer Center Limburg, School for Mental Health and Neuroscience, Maastricht University, Maastricht, The Netherlands.,Department of Neurology, Alzheimer Center Amsterdam, Vrije Universiteit Medical Center, Neuroscience Campus Amsterdam, Amsterdam, The Netherlands
| | - Frans R J Verhey
- Department of Psychiatry and Neuropsychology, Alzheimer Center Limburg, School for Mental Health and Neuroscience, Maastricht University, Maastricht, The Netherlands
| | - Marjo P H van de Waarenburg
- Department of Internal Medicine, School for Cardiovascular Diseases (CARIM), Maastricht University Medical Center, Maastricht, The Netherlands
| | - Casper G Schalkwijk
- Department of Internal Medicine, School for Cardiovascular Diseases (CARIM), Maastricht University Medical Center, Maastricht, The Netherlands
| | - Rudy M M A Nuijts
- University Eye Clinic Maastricht, Maastricht University Medical Center (MUMC+), School for Mental Health and Neuroscience, Maastricht University, P. Debyelaan 25, 6229 HX, Maastricht, The Netherlands
| | - Carroll A B Webers
- University Eye Clinic Maastricht, Maastricht University Medical Center (MUMC+), School for Mental Health and Neuroscience, Maastricht University, P. Debyelaan 25, 6229 HX, Maastricht, The Netherlands
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13
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Wang YR, Chuang HC, Tripathi A, Wang YL, Ko ML, Chuang CC, Chen JC. High-Sensitivity and Trace-Amount Specimen Electrochemical Sensors for Exploring the Levels of β-Amyloid in Human Blood and Tears. Anal Chem 2021; 93:8099-8106. [PMID: 34047190 DOI: 10.1021/acs.analchem.0c04980] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
As the occurrence of Alzheimer's disease (AD) has increased, the detection and treatment of AD have become global social issues. Effective early detection and wide-range screening of AD allow patients to gain early control and delay brain degeneration. For these reasons, we choose electrochemical sensors to complete the detection task. Although bio-electrochemical technology for antibody and antigen sensing is not a new technology, considering the scarcity of tear samples for dementia and since the existing AD detection techniques are highly invasive and expensive for subjects, we have to use the traditional detection techniques for the early screening of Alzheimer's disease via trace-amount specimens. An AD-related protein in the eye is thought to be an important biomarker for early detection. To carry out detection using tear samples as a test specimens, a tear collection device was developed in this study that extracted 10 μL of tear fluid from a tear Schirmer strip. In this research, we distinguished healthy people in different age groups and detect Aβ in both tear and blood samples. We developed a biosensor, which could detect Aβ in tear specimen from 1 to 100 pg/mL. Also, this biosensor is inexpensive, disposable, and easy to use. In our result, the concentration of Aβ in tears was approximately 10 times more than that in blood. This study demonstrates the feasibility and prospects of future screening for AD-associated biomarkers by a dynamic comparison between blood and tears.
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Affiliation(s)
- Yu-Rong Wang
- Institute of Biomedical Engineering, National Chiao Tung University, Hsinchu 30010, Taiwan
| | - Han-Chien Chuang
- Institute of Biomedical Engineering, National Chiao Tung University, Hsinchu 30010, Taiwan
| | - Adarsh Tripathi
- Institute of Molecular Medicine, National Tsing Hua University, Hsinchu 30010, Taiwan.,Institute of Nanoengineering and Microsystems, National Tsing Hua University, Hsinchu 30010, Taiwan
| | - Yu-Lin Wang
- Institute of Nanoengineering and Microsystems, National Tsing Hua University, Hsinchu 30010, Taiwan.,Department of Power Mechanical Engineering, National Tsing Hua University, Hsinchu 30010, Taiwan
| | - Mei-Lan Ko
- Department of Ophthalmology, National Taiwan University Hospital Hsin-Chu Branch, Hsinchu 30010, Taiwan.,Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu 30010, Taiwan
| | - Ching-Cheng Chuang
- Institute of Biomedical Engineering, National Chiao Tung University, Hsinchu 30010, Taiwan.,Department of Electrical and Computer Engineering, National Chiao Tung University, Hsinchu 30010, Taiwan
| | - Jung-Chih Chen
- Institute of Biomedical Engineering, National Chiao Tung University, Hsinchu 30010, Taiwan.,Department of Electrical and Computer Engineering, National Chiao Tung University, Hsinchu 30010, Taiwan.,Department of Biological Science and Technology, National Chiao Tung University, Hsinchu 30010, Taiwan
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14
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Chalkias IN, Tegos T, Topouzis F, Tsolaki M. Ocular biomarkers and their role in the early diagnosis of neurocognitive disorders. Eur J Ophthalmol 2021; 31:2808-2817. [PMID: 34000876 DOI: 10.1177/11206721211016311] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Given the fact that different types of dementia can be diagnosed only postmortem or when the disease has progressed enough to cause irreversible damage to certain brain areas, there has been an increasing need for the development of sensitive and reliable methods that can detect early preclinical forms of dementia, before the symptoms have even appeared. Ideally, such a method would have the following characteristics: to be inexpensive, sensitive and specific, Non-invasive, fast and easily accessible. The ophthalmologic examination and especially the study of the retina, has caught the attention of many researchers, as it can provide a lot of information about the CNS and it fulfills many of the aforementioned criteria. Since the introduction of the non-invasive optical coherence tomography (OCT) and the newly developed modality OCT-angiography (OCT-A) that can demonstrate the structure and the microvasculature of the retina and choroid, respectively, there have been promising results regarding the value of the ophthalmologic examination in the early diagnosis of Alzheimer's disease. In this review paper, we summarize and discuss the ocular findings in patients with cognitive impairment disorders and we highlight the importance of the ophthalmologic examination to the diagnosis of these disorders.
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Affiliation(s)
- Ioannis-Nikolaos Chalkias
- 1st Department of Ophthalmology, School of Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, Thessaloniki, Makedonia Thraki, Greece
| | - Thomas Tegos
- 1st Department of Neurology, School of Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, Thessaloniki, Makedonia Thraki, Greece
| | - Fotis Topouzis
- 1st Department of Ophthalmology, School of Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, Thessaloniki, Makedonia Thraki, Greece
| | - Magda Tsolaki
- 1st Department of Neurology, School of Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, Thessaloniki, Makedonia Thraki, Greece.,Greek Association of Alzheimer's Disease and Related Disorders, Thessaloniki, Greece
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15
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Fereshetian S, Agranat JS, Siegel N, Ness S, Stein TD, Subramanian ML. Protein and Imaging Biomarkers in the Eye for Early Detection of Alzheimer's Disease. J Alzheimers Dis Rep 2021; 5:375-387. [PMID: 34189409 PMCID: PMC8203283 DOI: 10.3233/adr-210283] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/26/2021] [Indexed: 12/28/2022] Open
Abstract
Alzheimer's disease (AD) is one of the most common causes of dementia worldwide. Although no formal curative therapy exists for the treatment of AD, considerable research has been performed to identify biomarkers for early detection of this disease, and thus improved subsequent management. Given that the eye can be examined and imaged non-invasively with relative ease, it has emerged as an exciting area of research for evidence of biomarkers and to aid in the early diagnosis of AD. This review explores the current understanding of both protein and retinal imaging biomarkers in the eye. Herein, primary findings in the literature regarding AD biomarkers associated with the lens, retina, and other ocular structures are reviewed.
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Affiliation(s)
- Shaunt Fereshetian
- Boston University School of Medicine, Department of Ophthalmology, Boston, MA, USA
| | - Joshua S. Agranat
- Boston University School of Medicine, Department of Ophthalmology, Boston, MA, USA
- Boston Medical Center, Boston, MA, USA
| | - Nicole Siegel
- Boston University School of Medicine, Department of Ophthalmology, Boston, MA, USA
- Boston Medical Center, Boston, MA, USA
| | - Steven Ness
- Boston University School of Medicine, Department of Ophthalmology, Boston, MA, USA
- Boston Medical Center, Boston, MA, USA
| | - Thor D. Stein
- Boston University Alzheimer’s Disease and CTE Center, Boston University School of Medicine, Boston, MA, USA
- Department of Pathology and Laboratory Medicine, Boston University School of Medicine, Boston, MA, USA
- VA Boston Healthcare System, Boston, MA, USA
- Department of Veterans Affairs Medical Center, Bedford, MA, USA
| | - Manju L. Subramanian
- Boston University School of Medicine, Department of Ophthalmology, Boston, MA, USA
- Boston Medical Center, Boston, MA, USA
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16
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Latina V, Giacovazzo G, Cordella F, Balzamino BO, Micera A, Varano M, Marchetti C, Malerba F, Florio R, Ercole BB, La Regina F, Atlante A, Coccurello R, Di Angelantonio S, Calissano P, Amadoro G. Systemic delivery of a specific antibody targeting the pathological N-terminal truncated tau peptide reduces retinal degeneration in a mouse model of Alzheimer's Disease. Acta Neuropathol Commun 2021; 9:38. [PMID: 33750467 PMCID: PMC7942014 DOI: 10.1186/s40478-021-01138-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Accepted: 02/26/2021] [Indexed: 12/28/2022] Open
Abstract
Retina and optic nerve are sites of extra-cerebral manifestations of Alzheimer's Disease (AD). Amyloid-β (Aβ) plaques and neurofibrillary tangles of hyperphosphorylated tau protein are detected in eyes from AD patients and transgenic animals in correlation with inflammation, reduction of synapses, visual deficits, loss of retinal cells and nerve fiber. However, neither the pathological relevance of other post-translational tau modifications-such as truncation with generation of toxic fragments-nor the potential neuroprotective action induced by their in vivo clearance have been investigated in the context of AD retinal degeneration. We have recently developed a monoclonal tau antibody (12A12mAb) which selectively targets the neurotoxic 20-22 kDa NH2-derived peptide generated from pathological truncation at the N-terminal domain of tau without cross-reacting with its full-length normal protein. Previous studies have shown that 12A12mAb, when intravenously (i.v.)-injected into 6-month-old Tg2576 animals, markedly improves their AD-like, behavioural and neuropathological syndrome. By taking advantage of this well-established tau-directed immunization regimen, we found that 12A12mAb administration also exerts a beneficial action on biochemical, morphological and metabolic parameters (i.e. APP/Aβ processing, tau hyperphosphorylation, neuroinflammation, synaptic proteins, microtubule stability, mitochondria-based energy production, neuronal death) associated with ocular injury in the AD phenotype. These findings prospect translational implications in the AD field by: (1) showing for the first time that cleavage of tau takes part in several pathological changes occurring in vivo in affected retinas and vitreous bodies and that its deleterious effects are successfully antagonized by administration of the specific 12A12mAb; (2) shedding further insights on the tight connections between neurosensory retina and brain, in particular following tau-based immunotherapy. In our view, the parallel response we detected in this preclinical animal model, both in the eye and in the hippocampus, following i.v. 12A12mAb injection opens novel diagnostic and therapeutic avenues for the clinical management of cerebral and extracerebral AD signs in human beings.
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Affiliation(s)
- Valentina Latina
- European Brain Research Institute (EBRI), Viale Regina Elena 295, 00161 Rome, Italy
| | - Giacomo Giacovazzo
- IRCSS Santa Lucia Foundation, Via Fosso del Fiorano 64-65, 00143 Rome, Italy
| | - Federica Cordella
- Department of Physiology and Pharmacology, University of Rome La Sapienza, Piazzale Aldo Moro 5, 00185 Rome, Italy
- Center for Life Nanoscience, Istituto Italiano Di Tecnologia, Viale Regina Elena 291, 00161 Rome, Italy
| | - Bijorn Omar Balzamino
- Research Laboratories in Ophthalmology, IRCCS - Fondazione Bietti, Via Santo Stefano Rotondo, 6, 00184 Rome, Italy
| | - Alessandra Micera
- Research Laboratories in Ophthalmology, IRCCS - Fondazione Bietti, Via Santo Stefano Rotondo, 6, 00184 Rome, Italy
| | - Monica Varano
- Research Laboratories in Ophthalmology, IRCCS - Fondazione Bietti, Via Santo Stefano Rotondo, 6, 00184 Rome, Italy
| | - Cristina Marchetti
- European Brain Research Institute (EBRI), Viale Regina Elena 295, 00161 Rome, Italy
| | - Francesca Malerba
- European Brain Research Institute (EBRI), Viale Regina Elena 295, 00161 Rome, Italy
| | - Rita Florio
- European Brain Research Institute (EBRI), Viale Regina Elena 295, 00161 Rome, Italy
| | - Bruno Bruni Ercole
- European Brain Research Institute (EBRI), Viale Regina Elena 295, 00161 Rome, Italy
| | - Federico La Regina
- European Brain Research Institute (EBRI), Viale Regina Elena 295, 00161 Rome, Italy
| | - Anna Atlante
- Institute of Biomembranes, Bioenergetics and Molecular Biotechnologies (IBIOM)-CNR, Via Amendola 122/O, 70126 Bari, Italy
| | - Roberto Coccurello
- IRCSS Santa Lucia Foundation, Via Fosso del Fiorano 64-65, 00143 Rome, Italy
- Institute for Complex System (ISC)-CNR, Via dei Taurini 19, 00185 Rome, Italy
| | - Silvia Di Angelantonio
- Department of Physiology and Pharmacology, University of Rome La Sapienza, Piazzale Aldo Moro 5, 00185 Rome, Italy
- Center for Life Nanoscience, Istituto Italiano Di Tecnologia, Viale Regina Elena 291, 00161 Rome, Italy
| | - Pietro Calissano
- European Brain Research Institute (EBRI), Viale Regina Elena 295, 00161 Rome, Italy
| | - Giuseppina Amadoro
- European Brain Research Institute (EBRI), Viale Regina Elena 295, 00161 Rome, Italy
- Institute of Translational Pharmacology (IFT), National Research Council (CNR), Via Fosso del Cavaliere 100, 00133 Rome, Italy
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17
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Wang L, Mao X. Role of Retinal Amyloid-β in Neurodegenerative Diseases: Overlapping Mechanisms and Emerging Clinical Applications. Int J Mol Sci 2021; 22:2360. [PMID: 33653000 PMCID: PMC7956232 DOI: 10.3390/ijms22052360] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 02/23/2021] [Accepted: 02/23/2021] [Indexed: 02/03/2023] Open
Abstract
Amyloid-β (Aβ) accumulations have been identified in the retina for neurodegeneration-associated disorders like Alzheimer's disease (AD), glaucoma, and age-related macular degeneration (AMD). Elevated retinal Aβ levels were associated with progressive retinal neurodegeneration, elevated cerebral Aβ accumulation, and increased disease severity with a decline in cognition and vision. Retinal Aβ accumulation and its pathological effects were demonstrated to occur prior to irreversible neurodegeneration, which highlights its potential in early disease detection and intervention. Using the retina as a model of the brain, recent studies have focused on characterizing retinal Aβ to determine its applicability for population-based screening of AD, which warrants a further understanding of how Aβ manifests between these disorders. While current treatments directly targeting Aβ accumulations have had limited results, continued exploration of Aβ-associated pathological pathways may yield new therapeutic targets for preserving cognition and vision. Here, we provide a review on the role of retinal Aβ manifestations in these distinct neurodegeneration-associated disorders. We also discuss the recent applications of retinal Aβ for AD screening and current clinical trial outcomes for Aβ-associated treatment approaches. Lastly, we explore potential future therapeutic targets based on overlapping mechanisms of pathophysiology in AD, glaucoma, and AMD.
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Affiliation(s)
- Liang Wang
- Miller School of Medicine, University of Miami, Miami, FL 33136, USA;
| | - Xiaobo Mao
- Neuroregeneration and Stem Cell Programs, Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
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18
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Retinal Degeneration and Alzheimer's Disease: An Evolving Link. Int J Mol Sci 2020; 21:ijms21197290. [PMID: 33023198 PMCID: PMC7582766 DOI: 10.3390/ijms21197290] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2020] [Revised: 09/15/2020] [Accepted: 09/25/2020] [Indexed: 12/13/2022] Open
Abstract
Age-related macular degeneration (AMD) and glaucoma are degenerative conditions of the retina and a significant cause of irreversible blindness in developed countries. Alzheimer’s disease (AD), the most common dementia of the elderly, is often associated with AMD and glaucoma. The cardinal features of AD include extracellular accumulation of amyloid β (Aβ) and intracellular deposits of hyper-phosphorylated tau (p-tau). Neuroinflammation and brain iron dyshomeostasis accompany Aβ and p-tau deposits and, together, lead to progressive neuronal death and dementia. The accumulation of Aβ and iron in drusen, the hallmark of AMD, and Aβ and p-tau in retinal ganglion cells (RGC), the main retinal cell type implicated in glaucoma, and accompanying inflammation suggest overlapping pathology. Visual abnormalities are prominent in AD and are believed to develop before cognitive decline. Some are caused by degeneration of the visual cortex, while others are due to RGC loss or AMD-associated retinal degeneration. Here, we review recent information on Aβ, p-tau, chronic inflammation, and iron dyshomeostasis as common pathogenic mechanisms linking the three degenerative conditions, and iron chelation as a common therapeutic option for these disorders. Additionally discussed is the role of prion protein, infamous for prion disorders, in Aβ-mediated toxicity and, paradoxically, in neuroprotection.
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19
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Subramanian ML, Vig V, Chung J, Fiorello MG, Xia W, Zetterberg H, Blennow K, Zetterberg M, Shareef F, Siegel NH, Ness S, Jun GR, Stein TD. Neurofilament light chain in the vitreous humor of the eye. Alzheimers Res Ther 2020; 12:111. [PMID: 32943089 PMCID: PMC7500015 DOI: 10.1186/s13195-020-00677-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Accepted: 09/01/2020] [Indexed: 12/13/2022]
Abstract
BACKGROUND Neurofilament light chain (NfL) is a promising biomarker of neurodegeneration in the cerebrospinal fluid and blood. This study investigated the presence of NfL in the vitreous humor and its associations with amyloid beta, tau, inflammatory cytokines and vascular proteins, apolipoprotein E (APOE) genotypes, Mini-Mental State Examination (MMSE) scores, systemic disease, and ophthalmic diseases. METHODS This is a single-site, prospective, cross-sectional cohort study. Undiluted vitreous fluid (0.5-1.0 mL) was aspirated during vitrectomy, and whole blood was drawn for APOE genotyping. NfL, amyloid beta (Aβ), total Tau (t-Tau), phosphorylated Tau (p-Tau181), inflammatory cytokines, chemokines, and vascular proteins in the vitreous were quantitatively measured by immunoassay. The main outcome measures were the detection of NfL levels in the vitreous humor and its associations with the aforementioned proteins. Linear regression was used to test the associations of NfL with other proteins, APOE genotypes, MMSE scores, and ophthalmic and systemic diseases after adjustment for age, sex, education level, and other eye diseases. RESULTS NfL was detected in all 77 vitreous samples. NfL was not found to be associated with ophthalmic conditions, APOE genotypes, MMSE scores, or systemic disease (p > 0.05). NfL levels were positively associated with increased vitreous levels of Aβ40 (p = 7.7 × 10-5), Aβ42 (p = 2.8 × 10-4), and t-tau (p = 5.5 × 10-7), but not with p-tau181 (p = 0.53). NfL also had significant associations with inflammatory cytokines such as interleukin-15 (IL-15, p = 5.3 × 10-4), IL-16 (p = 2.2 × 10-4), monocyte chemoattractant protein-1 (MCP1, p = 4.1 × 10-4), and vascular proteins such as vascular endothelial growth factor receptor-1 (VEGFR1, p = 2.9 × 10-6), Vegf-C (p = 8.6 × 10-6), vascular cell adhesion molecule-1 (VCAM-1, p = 5.0 × 10-4), Tie-2 (p = 6.3 × 10-4), and intracellular adhesion molecular-1 (ICAM-1, p = 1.6 × 10-4). CONCLUSION NfL is detectable in the vitreous humor of the eye and significantly associated with amyloid beta, t-tau, and select inflammatory and vascular proteins in the vitreous. Additionally, NfL was not associated with patients' clinical eye condition. Our results serve as a foundation for further investigation of NfL in the ocular fluids to inform us about the potential utility of its presence in the eye.
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Affiliation(s)
- Manju L Subramanian
- Department of Ophthalmology, Boston Medical Center, Boston University School of Medicine, 85 E Concord St. #8813, Boston, MA, 02118, USA.
| | - Viha Vig
- Department of Ophthalmology, Boston Medical Center, Boston University School of Medicine, 85 E Concord St. #8813, Boston, MA, 02118, USA
| | - Jaeyoon Chung
- Department of Medicine (Biomedical Genetics Section), Boston University School of Medicine, Boston, MA, USA
| | - Marissa G Fiorello
- Department of Ophthalmology, Boston Medical Center, Boston University School of Medicine, 85 E Concord St. #8813, Boston, MA, 02118, USA
| | - Weiming Xia
- Department of Pharmacology and Experimental Therapeutics, Boston University School of Medicine, Boston, MA, USA
- Geriatric Research Education and Clinical Center, Bedford Veterans Affairs Medical Center, Bedford, MA, USA
| | - Henrik Zetterberg
- Department of Psychiatry and Neurochemistry at Institute of Neuroscience and Physiology, Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden
- Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Mölndal, Sweden
- Department of Neurodegenerative Diseases, UCL Institute of Neurology, London, UK
- UK Dementia Research Institute at UCL, London, UK
| | - Kaj Blennow
- Department of Psychiatry and Neurochemistry at Institute of Neuroscience and Physiology, Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden
- Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Mölndal, Sweden
| | - Madeleine Zetterberg
- Department of Clinical Neuroscience at Institute of Neuroscience and Physiology, Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden
| | - Farah Shareef
- Department of Ophthalmology, University of Illinois at Chicago School of Medicine, Chicago, IL, USA
| | - Nicole H Siegel
- Department of Ophthalmology, Boston Medical Center, Boston University School of Medicine, 85 E Concord St. #8813, Boston, MA, 02118, USA
| | - Steven Ness
- Department of Ophthalmology, Boston Medical Center, Boston University School of Medicine, 85 E Concord St. #8813, Boston, MA, 02118, USA
| | - Gyungah R Jun
- Department of Medicine (Biomedical Genetics Section), Boston University School of Medicine, Boston, MA, USA
| | - Thor D Stein
- Boston University Alzheimer's Disease and CTE Center, Boston University School of Medicine, Boston, MA, USA
- Department of Pathology and Laboratory Medicine, Boston Medical Center, Boston University School of Medicine, Boston, MA, USA
- Department of Veterans Affairs Medical Center, VA Boston Healthcare System, Boston, MA, USA
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Bassi S. Commentary: Viewing Alzheimer's disease from an ophthalmologist's eyes. Indian J Ophthalmol 2020; 68:562-563. [PMID: 32174568 PMCID: PMC7210853 DOI: 10.4103/ijo.ijo_2132_19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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More SS, Beach JM, McClelland C, Mokhtarzadeh A, Vince R. In Vivo Assessment of Retinal Biomarkers by Hyperspectral Imaging: Early Detection of Alzheimer's Disease. ACS Chem Neurosci 2019; 10:4492-4501. [PMID: 31603648 DOI: 10.1021/acschemneuro.9b00331] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
A noninvasive and cost-effective means to detect preclinical Alzheimer's disease (AD) and monitor disease progression would be invaluable. The retina is a developmental extension of the brain and has been viewed as a window to evaluate AD-related pathology. Cross-sectional studies have shown structural changes in the retina of AD patients that include thinning of the retinal nerve-fiber layer and changes in retinal vasculature. However, such changes do not manifest in early stages of the disease nor are they specific biomarkers for AD. Described herein is the utilization of our retinal hyperspectral imaging (rHSI) technique as a biomarker for identification of AD-related early pathological changes in the retina. Specifically, this account concerns the translation of our rHSI technique from animal models to human AD subjects. The underlying principle is Rayleigh light scattering, which is expected from low-order Aβ aggregates present in early pathology. Recruitment was restricted to AD subjects (N = 19) and age-matched controls, with no family history of AD (N = 16). To limit the influence of skin pigmentation, subjects were restricted to those with skin pigmentation values of 2-3 on the Fitzpatrick scale. The largest spectral deviation from control subjects, rHSI signature, was obtained at the MCI stage with MMSE scores ⩾22, suggesting higher sensitivity of this technique in early disease stages. The rHSI signature observed is unaffected by eye pathologies such as glaucoma and cataract. Age of the subjects minimally influenced the spectral signatures. The rHSI technique shows promise for detection of preclinical AD; it is conducted in a truly noninvasive manner, without application of an exogenous label, and is thus potentially suitable for population screening.
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