1
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Carrero L, Antequera D, Municio C, Carro E. Circadian rhythm disruption and retinal dysfunction: a bidirectional link in Alzheimer's disease? Neural Regen Res 2024; 19:1967-1972. [PMID: 38227523 DOI: 10.4103/1673-5374.390962] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Accepted: 11/07/2023] [Indexed: 01/17/2024] Open
Abstract
Dysfunction in circadian rhythms is a common occurrence in patients with Alzheimer's disease. A predominant function of the retina is circadian synchronization, carrying information to the brain through the retinohypothalamic tract, which projects to the suprachiasmatic nucleus. Notably, Alzheimer's disease hallmarks, including amyloid-β, are present in the retinas of Alzheimer's disease patients, followed/associated by structural and functional disturbances. However, the mechanistic link between circadian dysfunction and the pathological changes affecting the retina in Alzheimer's disease is not fully understood, although some studies point to the possibility that retinal dysfunction could be considered an early pathological process that directly modulates the circadian rhythm.
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Affiliation(s)
- Laura Carrero
- Group of Neurodegenerative Diseases, Hospital Universitario 12 de Octubre Research Institute (imas12), Madrid, Spain; Network Center for Biomedical Research in Neurodegenerative Diseases (CIBERNED), ISCIII, Madrid, Spain
- PhD Program in Neuroscience, Autonoma de Madrid University, Madrid, Spain
| | - Desireé Antequera
- Neurobiology of Alzheimer's Disease Unit, Functional Unit for Research into Chronic Diseases, Instituto de Salud Carlos III, Madrid, Spain; Network Centre for Biomedical Research in Neurodegenerative Diseases (CIBERNED), ISCIII, Madrid, Spain
| | - Cristina Municio
- Group of Neurodegenerative Diseases, Hospital Universitario 12 de Octubre Research Institute (imas12), Madrid, Spain; Network Center for Biomedical Research in Neurodegenerative Diseases (CIBERNED), ISCIII, Madrid, Spain
| | - Eva Carro
- Neurobiology of Alzheimer's Disease Unit, Functional Unit for Research into Chronic Diseases, Instituto de Salud Carlos III, Madrid, Spain; Network Centre for Biomedical Research in Neurodegenerative Diseases (CIBERNED), ISCIII, Madrid, Spain
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2
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Hemsley KM, Beard H, Chidlow G, Mammone T, Winner LK, Neumann D, King B, Snel MF, Trim PJ, Casson RJ. Repetitive, non-invasive imaging of neurodegeneration, and prevention of it with gene replacement, in mice with Sanfilippo syndrome. Exp Neurol 2024; 371:114610. [PMID: 37944880 DOI: 10.1016/j.expneurol.2023.114610] [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: 05/24/2023] [Revised: 10/22/2023] [Accepted: 11/06/2023] [Indexed: 11/12/2023]
Abstract
Hampering assessment of treatment outcomes in gene therapy and other clinical trials in patients with childhood dementia is the lack of an objective, non-invasive measure of neurodegeneration. Optical coherence tomography (OCT) is a widely available, rapid, non-invasive, and quantitative method for examining the integrity of the neuroretina. Profound brain and retinal dysfunction occur in patients and animal models of childhood dementia, including Sanfilippo syndrome and we recently revealed a correlation between the age of onset and rate of progression of retinal and brain degeneration in sulfamidase-deficient Sanfilippo mice. The aim of the current study was to use OCT to visualise the discrete changes in retinal structure that occur during disease progression. A progressive decline in retinal thickness was readily observable in Sanfilippo mice using OCT, with differences seen in affected animals from 10-weeks of age. OCT applied to i.v. AAV9-sulfamidase-treated Sanfilippo mice enabled visualisation of improved retinal anatomy in living animals, an outcome confirmed via histology. Importantly, brain disease lesions were also ameliorated in treated Sanfilippo mice. The findings highlight the sensitivity, ease of repetitive use and quantitative capacity of OCT for detection of discrete changes in retinal structure and their prevention with a therapeutic. Combined with the knowledge that retinal and brain degeneration are correlated in Sanfilippo syndrome, OCT provides a window to the brain in this and potentially other childhood dementias.
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Affiliation(s)
- Kim M Hemsley
- Childhood Dementia Research Group, Hopwood Centre for Neurobiology, Lifelong Health Theme, South Australian Health and Medical Research Institute, Adelaide, SA, Australia.
| | - Helen Beard
- Childhood Dementia Research Group, Hopwood Centre for Neurobiology, Lifelong Health Theme, South Australian Health and Medical Research Institute, Adelaide, SA, Australia
| | - Glyn Chidlow
- Ophthalmic Research Laboratories, Discipline of Ophthalmology and Visual Sciences, University of Adelaide, Adelaide, SA, Australia
| | - Teresa Mammone
- Ophthalmic Research Laboratories, Discipline of Ophthalmology and Visual Sciences, University of Adelaide, Adelaide, SA, Australia
| | - Leanne K Winner
- Childhood Dementia Research Group, Hopwood Centre for Neurobiology, Lifelong Health Theme, South Australian Health and Medical Research Institute, Adelaide, SA, Australia
| | - Daniel Neumann
- Childhood Dementia Research Group, Hopwood Centre for Neurobiology, Lifelong Health Theme, South Australian Health and Medical Research Institute, Adelaide, SA, Australia
| | - Barbara King
- Childhood Dementia Research Group, Hopwood Centre for Neurobiology, Lifelong Health Theme, South Australian Health and Medical Research Institute, Adelaide, SA, Australia
| | - Marten F Snel
- Proteomics, Metabolomics and MS-Imaging Facility, South Australian Health, and Medical Research Institute, Adelaide, SA, Australia
| | - Paul J Trim
- Proteomics, Metabolomics and MS-Imaging Facility, South Australian Health, and Medical Research Institute, Adelaide, SA, Australia
| | - Robert J Casson
- Ophthalmic Research Laboratories, Discipline of Ophthalmology and Visual Sciences, University of Adelaide, Adelaide, SA, Australia
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3
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Shen L, Tang X, Zhang H, Zhuang H, Lin J, Zhao Y, Liu X. Targeted Metabolomic Analysis of the Eye Tissue of Triple Transgenic Alzheimer's Disease Mice at an Early Pathological Stage. Mol Neurobiol 2023; 60:7309-7328. [PMID: 37553545 DOI: 10.1007/s12035-023-03533-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Accepted: 07/22/2023] [Indexed: 08/10/2023]
Abstract
Alzheimer's disease (AD) is a severe neurodegenerative disease in older people. Despite some consensus on pathogenesis of AD established by previous researches, further elucidation is still required for better understanding. This study analyzed the eye tissues of 2- and 6-month-old triple transgenic AD (3 × Tg-AD) male mice and age-sex-matched wild-type (WT) mice using a targeted metabolomics approach. Compared with WT mice, 20 and 44 differential metabolites were identified in 2- and 6-month-old AD mice, respectively. They were associated with purine metabolism, pantothenate and CoA biosynthesis, pyruvate metabolism, lysine degradation, glycolysis/gluconeogenesis, and pyrimidine metabolism pathways. Among them, 8 metabolites presented differences in both the two groups, and 5 of them showed constant trend of change. The results indicated that the eye tissues of 3 × Tg-AD mice underwent changes in the early stages of the disease, with changes in metabolites observed at 2 months of age and more pronounced at 6 months of age, which is consistent with our previous studies on hippocampal targeted metabolomics in 3 × Tg-AD mice. Therefore, a joint analysis of data from this study and previous hippocampal study was performed, and the differential metabolites and their associated mechanisms were similar in eye and hippocampal tissues, but with tissue specificity.
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Affiliation(s)
- Liming Shen
- College of Life Science and Oceanography, Shenzhen University, Xueyuan Ave 1688, Shenzhen, 518060, People's Republic of China
- Shenzhen Bay Laboratory, Shenzhen, People's Republic of China
- Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen, 518055, People's Republic of China
- Shenzhen Key Laboratory of Marine, Biotechnology, and Ecology, Shenzhen, People's Republic of China
| | - Xiaoxiao Tang
- College of Life Science and Oceanography, Shenzhen University, Xueyuan Ave 1688, Shenzhen, 518060, People's Republic of China
| | - Huajie Zhang
- College of Life Science and Oceanography, Shenzhen University, Xueyuan Ave 1688, Shenzhen, 518060, People's Republic of China
| | - Hongbin Zhuang
- College of Life Science and Oceanography, Shenzhen University, Xueyuan Ave 1688, Shenzhen, 518060, People's Republic of China
| | - Jing Lin
- College of Life Science and Oceanography, Shenzhen University, Xueyuan Ave 1688, Shenzhen, 518060, People's Republic of China
| | - Yuxi Zhao
- College of Life Science and Oceanography, Shenzhen University, Xueyuan Ave 1688, Shenzhen, 518060, People's Republic of China
| | - Xukun Liu
- College of Life Science and Oceanography, Shenzhen University, Xueyuan Ave 1688, Shenzhen, 518060, People's Republic of China.
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4
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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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5
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Carrero L, Antequera D, Alcalde I, Megias D, Ordoñez-Gutierrez L, Gutierrez C, Merayo-Lloves J, Wandosell F, Municio C, Carro E. Altered Clock Gene Expression in Female APP/PS1 Mice and Aquaporin-Dependent Amyloid Accumulation in the Retina. Int J Mol Sci 2023; 24:15679. [PMID: 37958666 PMCID: PMC10648501 DOI: 10.3390/ijms242115679] [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: 09/28/2023] [Revised: 10/18/2023] [Accepted: 10/23/2023] [Indexed: 11/15/2023] Open
Abstract
Alzheimer's disease (AD), the most prevalent form of dementia, is a neurodegenerative disorder characterized by different pathological symptomatology, including disrupted circadian rhythm. The regulation of circadian rhythm depends on the light information that is projected from the retina to the suprachiasmatic nucleus in the hypothalamus. Studies of AD patients and AD transgenic mice have revealed AD retinal pathology, including amyloid-β (Aβ) accumulation that can directly interfere with the regulation of the circadian cycle. Although the cause of AD pathology is poorly understood, one of the main risk factors for AD is female gender. Here, we found that female APP/PS1 mice at 6- and 12-months old display severe circadian rhythm disturbances and retinal pathological hallmarks, including Aβ deposits in retinal layers. Since brain Aβ transport is facilitated by aquaporin (AQP)4, the expression of AQPs were also explored in APP/PS1 retina to investigate a potential correlation between retinal Aβ deposits and AQPs expression. Important reductions in AQP1, AQP4, and AQP5 were detected in the retinal tissue of these transgenic mice, mainly at 6-months of age. Taken together, our findings suggest that abnormal transport of Aβ, mediated by impaired AQPs expression, contributes to the retinal degeneration in the early stages of AD.
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Affiliation(s)
- Laura Carrero
- Neurobiology of Alzheimer’s Disease Unit, Functional Unit for Research into Chronic Diseases, Instituto de Salud Carlos III, Network Centre for Biomedical Research in Neurodegenerative Diseases (CIBERNED), ISCIII, 28029 Madrid, Spain; (L.C.); (D.A.); (C.G.)
- PhD Program in Neuroscience, Autonoma de Madrid University, 28049 Madrid, Spain
| | - Desireé Antequera
- Neurobiology of Alzheimer’s Disease Unit, Functional Unit for Research into Chronic Diseases, Instituto de Salud Carlos III, Network Centre for Biomedical Research in Neurodegenerative Diseases (CIBERNED), ISCIII, 28029 Madrid, Spain; (L.C.); (D.A.); (C.G.)
| | - Ignacio Alcalde
- Instituto Universitario Fernández-Vega, Universidad de Oviedo, Fundación de Investigación Oftalmológica, 28012 Oviedo, Spain; (I.A.); (J.M.-L.)
- Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), 33011 Oviedo, Spain
| | - Diego Megias
- Advanced Optical Microscopy Unit, Unidades Centrales Científico-Técnicas, Instituto de Salud Carlos III, 28222 Madrid, Spain;
| | - Lara Ordoñez-Gutierrez
- Centro de Biología Molecular “Severo Ochoa” (CSIC-UAM), Universidad Autónoma de Madrid, Network Centre for Biomedical Research in Neurodegenerative Diseases (CIBERNED), ISCIII, 28029 Madrid, Spain; (L.O.-G.); (F.W.)
| | - Cristina Gutierrez
- Neurobiology of Alzheimer’s Disease Unit, Functional Unit for Research into Chronic Diseases, Instituto de Salud Carlos III, Network Centre for Biomedical Research in Neurodegenerative Diseases (CIBERNED), ISCIII, 28029 Madrid, Spain; (L.C.); (D.A.); (C.G.)
| | - Jesús Merayo-Lloves
- Instituto Universitario Fernández-Vega, Universidad de Oviedo, Fundación de Investigación Oftalmológica, 28012 Oviedo, Spain; (I.A.); (J.M.-L.)
- Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), 33011 Oviedo, Spain
| | - Francisco Wandosell
- Centro de Biología Molecular “Severo Ochoa” (CSIC-UAM), Universidad Autónoma de Madrid, Network Centre for Biomedical Research in Neurodegenerative Diseases (CIBERNED), ISCIII, 28029 Madrid, Spain; (L.O.-G.); (F.W.)
| | - Cristina Municio
- Neurobiology of Alzheimer’s Disease Unit, Functional Unit for Research into Chronic Diseases, Instituto de Salud Carlos III, Network Centre for Biomedical Research in Neurodegenerative Diseases (CIBERNED), ISCIII, 28029 Madrid, Spain; (L.C.); (D.A.); (C.G.)
| | - Eva Carro
- Neurobiology of Alzheimer’s Disease Unit, Functional Unit for Research into Chronic Diseases, Instituto de Salud Carlos III, Network Centre for Biomedical Research in Neurodegenerative Diseases (CIBERNED), ISCIII, 28029 Madrid, Spain; (L.C.); (D.A.); (C.G.)
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6
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Holcombe B, Foes A, Banerjee S, Yeh K, Wang SHJ, Bhargava R, Ghosh A. Intermediate Antiparallel β Structure in Amyloid β Plaques Revealed by Infrared Spectroscopic Imaging. ACS Chem Neurosci 2023; 14:3794-3803. [PMID: 37800883 PMCID: PMC10662787 DOI: 10.1021/acschemneuro.3c00400] [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] [Indexed: 10/07/2023] Open
Abstract
Aggregation of amyloid β (Aβ) peptides into extracellular plaques is a hallmark of the molecular pathology of Alzheimer's disease (AD). Amyloid aggregates have been extensively studied in vitro, and it is well-known that mature amyloid fibrils contain an ordered parallel β structure. The structural evolution from unaggregated peptide to fibrils can be mediated through intermediate structures that deviate significantly from mature fibrils, such as antiparallel β-sheets. However, it is currently unknown if these intermediate structures exist in plaques, which limits the translation of findings from in vitro structural characterizations of amyloid aggregates to AD. This arises from the inability to extend common structural biology techniques to ex vivo tissue measurements. Here we report the use of infrared (IR) imaging, wherein we can spatially localize plaques and probe their protein structural distributions with the molecular sensitivity of IR spectroscopy. Analyzing individual plaques in AD tissues, we demonstrate that fibrillar amyloid plaques exhibit antiparallel β-sheet signatures, thus providing a direct connection between in vitro structures and amyloid aggregates in the AD brain. We further validate results with IR imaging of in vitro aggregates and show that the antiparallel β-sheet structure is a distinct structural facet of amyloid fibrils.
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Affiliation(s)
- Brooke Holcombe
- Department of Chemistry and Biochemistry, University of Alabama, Tuscaloosa, AL 35401, USA
| | - Abigail Foes
- Department of Chemistry and Biochemistry, University of Alabama, Tuscaloosa, AL 35401, USA
| | - Siddhartha Banerjee
- Department of Chemistry and Biochemistry, University of Alabama, Tuscaloosa, AL 35401, USA
| | - Kevin Yeh
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Shih-Hsiu J. Wang
- Departments of Pathology and Neurology, Duke University, Durham, NC 27710, USA
| | - Rohit Bhargava
- Departments of Bioengineering, Electrical and Computer Engineering, Mechanical Science and Engineering, Chemical and Biomolecular Engineering, and Chemistry, Beckman Institute for Advanced Science and Technology, Cancer Center at Illinois, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Ayanjeet Ghosh
- Department of Chemistry and Biochemistry, University of Alabama, Tuscaloosa, AL 35401, USA
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7
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Wang S, Jiang X, Peng W, Yang S, Pi R, Zhou S. Acrolein Induces Retinal Abnormalities of Alzheimer's Disease in Mice. Int J Mol Sci 2023; 24:13576. [PMID: 37686379 PMCID: PMC10487815 DOI: 10.3390/ijms241713576] [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: 07/18/2023] [Revised: 08/12/2023] [Accepted: 08/17/2023] [Indexed: 09/10/2023] Open
Abstract
It is reported that retinal abnormities are related to Alzheimer's disease (AD) in patients and animal models. However, it is unclear whether the retinal abnormities appear in the mouse model of sporadic Alzheimer's disease (sAD) induced by acrolein. We investigated the alterations of retinal function and structure, the levels of β-amyloid (Aβ) and phosphorylated Tau (p-Tau) in the retina, and the changes in the retinal vascular system in this mouse model. We demonstrated that the levels of Aβ and p-Tau were increased in the retinas of mice from the acrolein groups. Subsequently, a decreased amplitudes of b-waves in the scotopic and photopic electroretinogram (ERG), decreased thicknesses of the retinal nerve fiber layer (RNFL) in the retina, and slight retinal venous beading were found in the mice induced by acrolein. We propose that sAD mice induced by acrolein showed abnormalities in the retina, which may provide a valuable reference for the study of the retina in sAD.
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Affiliation(s)
- Shuyi Wang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
| | - Xiuying Jiang
- Department of Ophthalmology, Affiliated Foshan Hospital, Southern Medical University, Foshan 528000, China
| | - Weijia Peng
- School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Shuangjian Yang
- Guangdong Provincial Institute for Vision and Eye Research, Guangzhou 510060, China
| | - Rongbiao Pi
- School of Medicine, Sun Yat-sen University, Shenzhen 528406, China
| | - Shiyou Zhou
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
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8
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Holcombe B, Foes A, Banerjee S, Yeh K, Wang SHJ, Bhargava R, Ghosh A. Intermediate antiparallel beta structure in amyloid plaques revealed by infrared spectroscopic imaging. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.18.537414. [PMID: 37131832 PMCID: PMC10153194 DOI: 10.1101/2023.04.18.537414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Aggregation of amyloid beta (Aβ) peptides into extracellular plaques is a hallmark of the molecular pathology of Alzheimer's disease (AD). Amyloid aggregates have been extensively studied in-vitro, and it is well known that mature amyloid fibrils contain an ordered parallel β structure. The structural evolution from unaggregated peptide to fibrils can be mediated through intermediate structures that deviate significantly from mature fibrils, such as antiparallel β-sheets. However, it is currently unknown if these intermediate structures exist in plaques, which limits the translation of findings from in-vitro structural characterizations of amyloid aggregates to AD. This arises from the inability to extend common structural biology techniques to ex-vivo tissue measurements. Here we report the use of infrared (IR) imaging, wherein we can spatially localize plaques and probe their protein structural distributions with the molecular sensitivity of IR spectroscopy. Analyzing individual plaques in AD tissues, we demonstrate that fibrillar amyloid plaques exhibit antiparallel β-sheet signatures, thus providing a direct connection between in-vitro structures and amyloid aggregates in AD brain. We further validate results with IR imaging of in-vitro aggregates and show that antiparallel β-sheet structure is a distinct structural facet of amyloid fibrils.
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Affiliation(s)
- Brooke Holcombe
- Department of Chemistry and Biochemistry, University of Alabama, Tuscaloosa, AL 35401, USA
| | - Abigail Foes
- Department of Chemistry and Biochemistry, University of Alabama, Tuscaloosa, AL 35401, USA
| | - Siddhartha Banerjee
- Department of Chemistry and Biochemistry, University of Alabama, Tuscaloosa, AL 35401, USA
| | - Kevin Yeh
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Shih-Hsiu J. Wang
- Departments of Pathology and Neurology, Duke University, Durham, NC 27710, USA
| | - Rohit Bhargava
- Departments of Bioengineering, Electrical and Computer Engineering, Mechanical Science and Engineering, Chemical and Biomolecular Engineering, and Chemistry, Beckman Institute for Advanced Science and Technology, Cancer Center at Illinois, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Ayanjeet Ghosh
- Department of Chemistry and Biochemistry, University of Alabama, Tuscaloosa, AL 35401, USA
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9
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Batista A, Guimarães P, Martins J, Moreira PI, Ambrósio AF, Castelo-Branco M, Serranho P, Bernardes R. Normative mice retinal thickness: 16-month longitudinal characterization of wild-type mice and changes in a model of Alzheimer's disease. Front Aging Neurosci 2023; 15:1161847. [PMID: 37091517 PMCID: PMC10117679 DOI: 10.3389/fnagi.2023.1161847] [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: 02/08/2023] [Accepted: 03/21/2023] [Indexed: 04/08/2023] Open
Abstract
Animal models of disease are paramount to understand retinal development, the pathophysiology of eye diseases, and to study neurodegeneration using optical coherence tomography (OCT) data. In this study, we present a comprehensive normative database of retinal thickness in C57BL6/129S mice using spectral-domain OCT data. The database covers a longitudinal period of 16 months, from 1 to 16 months of age, and provides valuable insights into retinal development and changes over time. Our findings reveal that total retinal thickness decreases with age, while the thickness of individual retinal layers and layer aggregates changes in different ways. For example, the outer plexiform layer (OPL), photoreceptor inner segments (ILS), and retinal pigment epithelium (RPE) thickened over time, whereas other retinal layers and layer aggregates became thinner. Additionally, we compare the retinal thickness of wild-type (WT) mice with an animal model of Alzheimer's disease (3 × Tg-AD) and show that the transgenic mice exhibit a decrease in total retinal thickness compared to age-matched WT mice, with statistically significant differences observed at all evaluated ages. This normative database of retinal thickness in mice will serve as a reference for future studies on retinal changes in neurodegenerative and eye diseases and will further our understanding of the pathophysiology of these conditions.
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Affiliation(s)
- Ana Batista
- Coimbra Institute for Biomedical Imaging and Translational Research (CIBIT), Institute for Nuclear Sciences Applied to Health (ICNAS), University of Coimbra, Coimbra, Portugal
| | - Pedro Guimarães
- Coimbra Institute for Biomedical Imaging and Translational Research (CIBIT), Institute for Nuclear Sciences Applied to Health (ICNAS), University of Coimbra, Coimbra, Portugal
| | - João Martins
- Coimbra Institute for Biomedical Imaging and Translational Research (CIBIT), Institute for Nuclear Sciences Applied to Health (ICNAS), University of Coimbra, Coimbra, Portugal
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine (FMUC), University of Coimbra, Coimbra, Portugal
- Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, Coimbra, Portugal
- Clinical Academic Center of Coimbra (CACC), Faculty of Medicine (FMUC), University of Coimbra, Coimbra, Portugal
| | - Paula I. Moreira
- Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, Coimbra, Portugal
- Clinical Academic Center of Coimbra (CACC), Faculty of Medicine (FMUC), University of Coimbra, Coimbra, Portugal
- Laboratory of Physiology, Faculty of Medicine (FMUC), University of Coimbra, Coimbra, Portugal
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Coimbra, Portugal
| | - António Francisco Ambrósio
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine (FMUC), University of Coimbra, Coimbra, Portugal
- Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, Coimbra, Portugal
- Clinical Academic Center of Coimbra (CACC), Faculty of Medicine (FMUC), University of Coimbra, Coimbra, Portugal
| | - Miguel Castelo-Branco
- Coimbra Institute for Biomedical Imaging and Translational Research (CIBIT), Institute for Nuclear Sciences Applied to Health (ICNAS), University of Coimbra, Coimbra, Portugal
- Clinical Academic Center of Coimbra (CACC), Faculty of Medicine (FMUC), University of Coimbra, Coimbra, Portugal
| | - Pedro Serranho
- Coimbra Institute for Biomedical Imaging and Translational Research (CIBIT), Institute for Nuclear Sciences Applied to Health (ICNAS), University of Coimbra, Coimbra, Portugal
- Mathematics Section, Department of Sciences and Technology, Universidade Aberta, Lisbon, Portugal
| | - Rui Bernardes
- Coimbra Institute for Biomedical Imaging and Translational Research (CIBIT), Institute for Nuclear Sciences Applied to Health (ICNAS), University of Coimbra, Coimbra, Portugal
- Clinical Academic Center of Coimbra (CACC), Faculty of Medicine (FMUC), University of Coimbra, Coimbra, Portugal
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10
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Brain region-specific myelinogenesis is not directly linked to amyloid-β in APP/PS1 transgenic mice. Exp Neurol 2023; 362:114344. [PMID: 36736651 DOI: 10.1016/j.expneurol.2023.114344] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Revised: 01/23/2023] [Accepted: 01/29/2023] [Indexed: 02/05/2023]
Abstract
Alzheimer's disease (AD) is characterized by aggregating amyloid beta-protein (Aβ). Recent evidence has shown that insufficient myelinogenesis contributes to AD-related functional deficits. However, it remains unclear whether Aβ, in either plaque or soluble form, could alter myelinogenesis in AD brains. By cell-lineage tracing and labeling, we found both myelinogenesis and Aβ deposits displayed a region-specific pattern in the 13-month-old APP/PS1 transgenic mouse brains. Aβ plaques cause focal demyelination, but only about 15% Aβ plaques are closely associated with newly formed myelin in the APP/PS1 brains. Further, the Aβ plaque total area and the amount of new myelin are not linearly correlated across different cortical regions, suggesting that Aβ plaques induce demyelination but may not exclusively trigger remyelination. To understand the role of soluble Aβ in regulating myelinogenesis, we chose to observe the visual system, wherein soluble Aβ is detectable but without the presence of Aβ plaques in the APP/PS1 retina, optic nerve, and optic tract. Interestingly, newly-formed myelin density was not significantly altered in the APP/PS1 optic nerves and optic tracts as compared to the wildtype controls, suggesting soluble Aβ probably does not change myelinogenesis. Further, treatment of purified oligodendrocyte precursor cells (OPCs) with soluble Aβ (oligomers) for 48 h did not change the cell densities of MBP positive cells and PDGFRα positive OPCs in vitro. Consistently, injection of soluble Aβ into the lateral ventricles did not alter myelinogenesis in the corpus callosum of NG2-CreErt; Tau-mGFP mice significantly. Together, these findings indicate that the region-dependent myelinogenesis in AD brains is not directly linked to Aβ, but rather probably a synergic result in adapting to AD pathology.
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11
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Hart de Ruyter FJ, Morrema THJ, den Haan J, Twisk JWR, de Boer JF, Scheltens P, Boon BDC, Thal DR, Rozemuller AJ, Verbraak FD, Bouwman FH, Hoozemans JJM. Phosphorylated tau in the retina correlates with tau pathology in the brain in Alzheimer's disease and primary tauopathies. Acta Neuropathol 2023; 145:197-218. [PMID: 36480077 DOI: 10.1007/s00401-022-02525-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Revised: 11/22/2022] [Accepted: 11/22/2022] [Indexed: 12/13/2022]
Abstract
The retina is a potential source of biomarkers for the detection of neurodegenerative diseases. Accumulation of phosphorylated tau (p-tau) in the brain is a pathological feature characteristic for Alzheimer's disease (AD) and primary tauopathies. In this study the presence of p-tau in the retina in relation to tau pathology in the brain was assessed. Post-mortem eyes and brains were collected through the Netherlands Brain Bank from donors with AD (n = 17), primary tauopathies (n = 8), α-synucleinopathies (n = 13), other neurodegenerative diseases including non-tau frontotemporal lobar degeneration (FTLD) (n = 9), and controls (n = 15). Retina cross-sections were assessed by immunohistochemistry using antibodies directed against total tau (HT7), 3R and 4R tau isoforms (RD3, RD4), and phospho-epitopes Ser202/Thr205 (AT8), Thr217 (anti-T217), Thr212/Ser214 (AT100), Thr181 (AT270), Ser396 (anti-pS396) and Ser422 (anti-pS422). Retinal tau load was compared to p-tau Ser202/Thr205 and p-tau Thr217 load in various brain regions. Total tau, 3R and 4R tau isoforms were most prominently present in the inner plexiform layer (IPL) and outer plexiform layer (OPL) of the retina and were detected in all cases and controls as a diffuse and somatodendritic signal. Total tau, p-tau Ser202/Thr205 and p-tau Thr217 was observed in amacrine and horizontal cells of the inner nuclear layer (INL). Various antibodies directed against phospho-epitopes of tau showed immunoreactivity in the IPL, OPL, and INL. P-tau Ser202/Thr205 and Thr217 showed significant discrimination between AD and other tauopathies, and non-tauopathy cases including controls. Whilst immunopositivity was observed for p-tau Thr212/Ser214, Thr181 and Ser396, there were no group differences. P-tau Ser422 did not show any immunoreactivity in the retina. The presence of retinal p-tau Ser202/Thr205 and Thr217 correlated with Braak stage for NFTs and with the presence of p-tau Ser202/Thr205 in hippocampus and cortical brain regions. Depending on the phospho-epitope, p-tau in the retina is a potential biomarker for AD and primary tauopathies.
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Affiliation(s)
- Frederique J Hart de Ruyter
- Amsterdam UMC Location Vrije Universiteit Amsterdam, Pathology, De Boelelaan 1117, Amsterdam, The Netherlands.
- Alzheimer Center Amsterdam, Neurology, Vrije Universiteit Amsterdam, Amsterdam UMC Location VUmc, Amsterdam, The Netherlands.
| | - Tjado H J Morrema
- Amsterdam UMC Location Vrije Universiteit Amsterdam, Pathology, De Boelelaan 1117, Amsterdam, The Netherlands
| | - Jurre den Haan
- Alzheimer Center Amsterdam, Neurology, Vrije Universiteit Amsterdam, Amsterdam UMC Location VUmc, Amsterdam, The Netherlands
| | - Jos W R Twisk
- Epidemiology and Data Science, Amsterdam UMC Location Vrije Universiteit Amsterdam, De Boelelaan 1117, Amsterdam, The Netherlands
| | - Johannes F de Boer
- Vrije Universiteit Amsterdam, LaserLaB, Physics and Astronomy, Amsterdam, The Netherlands
| | - Philip Scheltens
- Alzheimer Center Amsterdam, Neurology, Vrije Universiteit Amsterdam, Amsterdam UMC Location VUmc, Amsterdam, The Netherlands
| | - Baayla D C Boon
- Amsterdam UMC Location Vrije Universiteit Amsterdam, Pathology, De Boelelaan 1117, Amsterdam, The Netherlands
- Alzheimer Center Amsterdam, Neurology, Vrije Universiteit Amsterdam, Amsterdam UMC Location VUmc, Amsterdam, The Netherlands
- Mayo Clinic, Neuroscience, Jacksonville, FL, USA
| | - Dietmar R Thal
- Laboratory for Neuropathology, Department of Imaging and Pathology, KU Leuven (University of Leuven), Leuven Brain Institute, O&N IV Herestraat 49, 3000, Louvain, Belgium
- Department of Pathology, University Hospitals Leuven, 3000, Louvain, Belgium
| | - Annemieke J Rozemuller
- Amsterdam UMC Location Vrije Universiteit Amsterdam, Pathology, De Boelelaan 1117, Amsterdam, The Netherlands
| | - Frank D Verbraak
- Amsterdam UMC Location Vrije Universiteit Amsterdam, Ophthalmology, De Boelelaan 1117, Amsterdam, The Netherlands
| | - Femke H Bouwman
- Alzheimer Center Amsterdam, Neurology, Vrije Universiteit Amsterdam, Amsterdam UMC Location VUmc, Amsterdam, The Netherlands
- Amsterdam Neuroscience, Neurodegeneration, Amsterdam, The Netherlands
| | - Jeroen J M Hoozemans
- Amsterdam UMC Location Vrije Universiteit Amsterdam, Pathology, De Boelelaan 1117, Amsterdam, The Netherlands.
- Amsterdam Neuroscience, Neurodegeneration, Amsterdam, The Netherlands.
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12
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Construction and functional enrichment analysis of the competitive endogenous RNA regulatory network for nonarteritic anterior ischemic optic neuropathy based on high-throughput sequencing. Funct Integr Genomics 2022; 22:1253-1267. [DOI: 10.1007/s10142-022-00914-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 09/26/2022] [Accepted: 11/03/2022] [Indexed: 11/11/2022]
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13
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Guimarães P, Serranho P, Martins J, Moreira PI, Ambrósio AF, Castelo-Branco M, Bernardes R. Retinal Aging in 3× Tg-AD Mice Model of Alzheimer's Disease. Front Aging Neurosci 2022; 14:832195. [PMID: 35783138 PMCID: PMC9244797 DOI: 10.3389/fnagi.2022.832195] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Accepted: 05/16/2022] [Indexed: 11/13/2022] Open
Abstract
The retina, as part of the central nervous system (CNS), can be the perfect target for in vivo, in situ, and noninvasive neuropathology diagnosis and assessment of therapeutic efficacy. It has long been established that several age-related brain changes are more pronounced in Alzheimer's disease (AD). Nevertheless, in the retina such link is still under-explored. This study investigates the differences in the aging of the CNS through the retina of 3× Tg-AD and wild-type mice. A dedicated optical coherence tomograph imaged mice's retinas for 16 months. Two neural networks were developed to model independently each group's ages and were then applied to an independent set containing images from both groups. Our analysis shows a mean absolute error of 0.875±1.1 × 10−2 and 1.112±1.4 × 10−2 months, depending on training group. Our deep learning approach appears to be a reliable retinal OCT aging marker. We show that retina aging is distinct in the two classes: the presence of the three mutated human genes in the mouse genome has an impact on the aging of the retina. For mice over 4 months-old, transgenic mice consistently present a negative retina age-gap when compared to wild-type mice, regardless of training set. This appears to contradict AD observations in the brain. However, the ‘black-box” nature of deep-learning implies that one cannot infer reasoning. We can only speculate that some healthy age-dependent neural adaptations may be altered in transgenic animals.
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Affiliation(s)
- Pedro Guimarães
- Coimbra Institute for Biomedical Imaging and Translational Research (CIBIT), Institute for Nuclear Sciences Applied to Health (ICNAS), University of Coimbra, Coimbra, Portugal
- *Correspondence: Pedro Guimarães
| | - Pedro Serranho
- Coimbra Institute for Biomedical Imaging and Translational Research (CIBIT), Institute for Nuclear Sciences Applied to Health (ICNAS), University of Coimbra, Coimbra, Portugal
- Department of Sciences and Technology, Universidade Aberta, Lisbon, Portugal
| | - João Martins
- Coimbra Institute for Biomedical Imaging and Translational Research (CIBIT), Institute for Nuclear Sciences Applied to Health (ICNAS), University of Coimbra, Coimbra, Portugal
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine (FMUC), University of Coimbra, Coimbra, Portugal
- Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, Coimbra, Portugal
- Clinical Academic Center of Coimbra (CACC), Faculty of Medicine (FMUC), University of Coimbra, Coimbra, Portugal
| | - Paula I. Moreira
- Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, Coimbra, Portugal
- Clinical Academic Center of Coimbra (CACC), Faculty of Medicine (FMUC), University of Coimbra, Coimbra, Portugal
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Coimbra, Portugal
| | - António Francisco Ambrósio
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine (FMUC), University of Coimbra, Coimbra, Portugal
- Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, Coimbra, Portugal
- Clinical Academic Center of Coimbra (CACC), Faculty of Medicine (FMUC), University of Coimbra, Coimbra, Portugal
| | - Miguel Castelo-Branco
- Coimbra Institute for Biomedical Imaging and Translational Research (CIBIT), Institute for Nuclear Sciences Applied to Health (ICNAS), University of Coimbra, Coimbra, Portugal
- Clinical Academic Center of Coimbra (CACC), Faculty of Medicine (FMUC), University of Coimbra, Coimbra, Portugal
| | - Rui Bernardes
- Coimbra Institute for Biomedical Imaging and Translational Research (CIBIT), Institute for Nuclear Sciences Applied to Health (ICNAS), University of Coimbra, Coimbra, Portugal
- Clinical Academic Center of Coimbra (CACC), Faculty of Medicine (FMUC), University of Coimbra, Coimbra, Portugal
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14
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Guo L, Choi S, Bikkannavar P, Cordeiro MF. Microglia: Key Players in Retinal Ageing and Neurodegeneration. Front Cell Neurosci 2022; 16:804782. [PMID: 35370560 PMCID: PMC8968040 DOI: 10.3389/fncel.2022.804782] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Accepted: 02/11/2022] [Indexed: 12/20/2022] Open
Abstract
Microglia are the resident immune cells of the central nervous system (CNS) and play a key role in maintaining the normal function of the retina and brain. During early development, microglia migrate into the retina, transform into a highly ramified phenotype, and scan their environment constantly. Microglia can be activated by any homeostatic disturbance that may endanger neurons and threaten tissue integrity. Once activated, the young microglia exhibit a high diversity in their phenotypes as well as their functions, which relate to either beneficial or harmful consequences. Microglial activation is associated with the release of cytokines, chemokines, and growth factors that can determine pathological outcomes. As the professional phagocytes in the retina, microglia are responsible for the clearance of pathogens, dead cells, and protein aggregates. However, their phenotypic diversity and phagocytic capacity is compromised with ageing. This may result in the accumulation of protein aggregates and myelin debris leading to retinal neuroinflammation and neurodegeneration. In this review, we describe microglial phenotypes and functions in the context of the young and ageing retina, and the mechanisms underlying changes in ageing. Additionally, we review microglia-mediated retinal neuroinflammation and discuss the mechanisms of microglial involvement in retinal neurodegenerative diseases.
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Affiliation(s)
- Li Guo
- Institute of Ophthalmology, University College London, London, United Kingdom
- *Correspondence: Li Guo,
| | - Soyoung Choi
- Institute of Ophthalmology, University College London, London, United Kingdom
| | | | - M. Francesca Cordeiro
- Institute of Ophthalmology, University College London, London, United Kingdom
- Imperial College Ophthalmology Research Group, Imperial College London, London, United Kingdom
- M. Francesca Cordeiro,
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15
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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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16
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Mahaman YAR, Embaye KS, Huang F, Li L, Zhu F, Wang JZ, Liu R, Feng J, Wang X. Biomarkers used in Alzheimer's disease diagnosis, treatment, and prevention. Ageing Res Rev 2022; 74:101544. [PMID: 34933129 DOI: 10.1016/j.arr.2021.101544] [Citation(s) in RCA: 47] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 12/09/2021] [Accepted: 12/15/2021] [Indexed: 12/12/2022]
Abstract
Alzheimer's disease (AD), being the number one in terms of dementia burden, is an insidious age-related neurodegenerative disease and is presently considered a global public health threat. Its main histological hallmarks are the Aβ senile plaques and the P-tau neurofibrillary tangles, while clinically it is marked by a progressive cognitive decline that reflects the underlying synaptic loss and neurodegeneration. Many of the drug therapies targeting the two pathological hallmarks namely Aβ and P-tau have been proven futile. This is probably attributed to the initiation of therapy at a stage where cognitive alterations are already obvious. In other words, the underlying neuropathological changes are at a stage where these drugs lack any therapeutic value in reversing the damage. Therefore, there is an urgent need to start treatment in the very early stage where these changes can be reversed, and hence, early diagnosis is of primordial importance. To this aim, the use of robust and informative biomarkers that could provide accurate diagnosis preferably at an earlier phase of the disease is of the essence. To date, several biomarkers have been established that, to a different extent, allow researchers and clinicians to evaluate, diagnose, and more specially exclude other related pathologies. In this study, we extensively reviewed data on the currently explored biomarkers in terms of AD pathology-specific and non-specific biomarkers and highlighted the recent developments in the diagnostic and theragnostic domains. In the end, we have presented a separate elaboration on aspects of future perspectives and concluding remarks.
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17
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Liu J, Baum L, Yu S, Lin Y, Xiong G, Chang RCC, So KF, Chiu K. Preservation of Retinal Function Through Synaptic Stabilization in Alzheimer's Disease Model Mouse Retina by Lycium Barbarum Extracts. Front Aging Neurosci 2022; 13:788798. [PMID: 35095474 PMCID: PMC8792986 DOI: 10.3389/fnagi.2021.788798] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2021] [Accepted: 12/20/2021] [Indexed: 01/11/2023] Open
Abstract
In Alzheimer's disease (AD), amyloid β deposition-induced hippocampal synaptic dysfunction generally begins prior to neuronal degeneration and memory impairment. Lycium barbarum extracts (LBE) have been demonstrated to be neuroprotective in various animal models of neurodegeneration. In this study, we aimed to investigate the effects of LBE on the synapse loss in AD through the avenue of the retina in a triple transgenic mouse model of AD (3xTg-AD). We fed 3xTg-AD mice with low (200 mg/kg) or high (2 g/kg) dose hydrophilic LBE daily for 2 months from the starting age of 4- or 6-month-old. For those started at 6 month age, at 1 month (though not 2 months) after starting treatment, mice given high dose LBE showed a significant increase of a wave and b wave in scotopic ERG. After 2 months of treatment with high dose LBE, calpain-2, calpain-5, and the oxidative RNA marker 8-OHG were downregulated, and presynaptic densities in the inner plexiform layer but not the outer plexiform layer of the retina were significantly increased, suggesting the presynaptic structure of retina was preserved. Our results indicate that LBE feeding may preserve synapse stability in the retina of 3xTg-AD mice, probably by decreasing both oxidative stress and intracellular calcium influx. Thus, LBE might have potential as a neuroprotectant for AD through synapse preservation.
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Affiliation(s)
- Jinfeng Liu
- Department of Ophthalmology, LKS Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
| | - Larry Baum
- Department of Psychiatry, LKS Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
- State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
| | - Shasha Yu
- Department of Ophthalmology, LKS Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
- Tianjin Key Lab of Ophthalmology and Visual Science, Clinical College of Ophthalmology, Tianjin Eye Hospital, Nankai University Eye Hospital, Tianjin Eye Institute, Tianjin Medical University, Tianjin, China
| | - Youhong Lin
- Department of Ophthalmology, LKS Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
| | - Guoying Xiong
- Department of Ophthalmology, LKS Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
| | - Raymond Chuen-Chung Chang
- State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
- Laboratory of Neurodegenerative Diseases, School of Biomedical Sciences, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
| | - Kwok Fai So
- Department of Ophthalmology, LKS Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
- State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
- Department of Psychology, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
- Guangdong-Hongkong-Macau Institute of CNS Regeneration, Jinan University, Guangzhou, China
- Kwok Fai So
| | - Kin Chiu
- Department of Ophthalmology, LKS Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
- State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
- Department of Psychology, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
- *Correspondence: Kin Chiu
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18
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Confer MP, Holcombe BM, Foes AG, Holmquist JM, Walker SC, Deb S, Ghosh A. Label-Free Infrared Spectroscopic Imaging Reveals Heterogeneity of β-Sheet Aggregates in Alzheimer's Disease. J Phys Chem Lett 2021; 12:9662-9671. [PMID: 34590866 PMCID: PMC8933041 DOI: 10.1021/acs.jpclett.1c02306] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
The aggregation of the amyloid beta (Aβ) protein into plaques is a pathological feature of Alzheimer's disease (AD). While amyloid aggregates have been extensively studied in vitro, their structural aspects and associated chemistry in the brain are not fully understood. In this report, we demonstrate, using infrared spectroscopic imaging, that Aβ plaques exhibit significant heterogeneities in terms of their secondary structure and phospholipid content. We show that the capabilities of discrete frequency infrared imaging (DFIR) are ideally suited for characterization of amyloid deposits in brain tissues and employ DFIR to identify nonplaque β-sheet aggregates distributed throughout brain tissues. We further demonstrate that phospholipid-rich β-sheet deposits exist outside of plaques in all diseased tissues, indicating their potential clinical significance. This is the very first application of DFIR toward a characterization of protein aggregates in an AD brain and provides a rapid, label-free approach that allows us to uncover β-sheet heterogeneities in the AD, which may be significant for targeted therapeutic strategies in the future.
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19
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Zhang M, Zhong L, Han X, Xiong G, Xu D, Zhang S, Cheng H, Chiu K, Xu Y. Brain and Retinal Abnormalities in the 5xFAD Mouse Model of Alzheimer's Disease at Early Stages. Front Neurosci 2021; 15:681831. [PMID: 34366774 PMCID: PMC8343228 DOI: 10.3389/fnins.2021.681831] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 06/16/2021] [Indexed: 11/13/2022] Open
Abstract
One of the major challenges in treating Alzheimer's disease (AD) is its early diagnosis. Increasing data from clinical and animal research indicate that the retina may facilitate an early diagnosis of AD. However, a previous study on the 5xFAD (a fast AD model), showing retinal changes before those in the brain, has been questioned because of the involvement of the retinal degeneration allele Pde6brd1. Here, we tested in parallel, at 4 and 6 months of age, both the retinal and the brain structure and function in a 5xFAD mouse line that carries no mutation of rd1. In the three tested regions of the 5xFAD brain (hippocampus, visual cortex, and olfactory bulb), the Aβ plaques were more numerous than in wild-type (WT) littermates already at 4 months, but deterioration in the cognitive behavioral test and long-term potentiation (LTP) lagged behind, showing significant deterioration only at 6 months. Similarly in the retina, structural changes preceded functional decay. At 4 months, the retina was generally normal except for a thicker outer nuclear layer in the middle region than WT. At 6 months, the visual behavior (as seen by an optomotor test) was clearly impaired. While the full-field and pattern electroretinogram (ERG) responses were relatively normal, the light responses of the retinal ganglion cells (measured with multielectrode-array recording) were decreased. Structurally, the retina became abnormally thick with few more Aβ plaques and activated glia cells. In conclusion, the timeline of the degenerative processes in the retina and the brain is similar, supporting the use of non-invasive methods to test the retinal structure and function to reflect changes in the brain for early AD diagnosis.
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Affiliation(s)
- Mengrong Zhang
- Guangdong-Hongkong-Macau Institute of Central Nervous System Regeneration, Jinan University, Guangzhou, China
| | - Liting Zhong
- Guangdong-Hongkong-Macau Institute of Central Nervous System Regeneration, Jinan University, Guangzhou, China
| | - Xiu Han
- Guangdong-Hongkong-Macau Institute of Central Nervous System Regeneration, Jinan University, Guangzhou, China
| | - Guoyin Xiong
- Department of Ophthalmology, LKF Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Di Xu
- Guangdong-Hongkong-Macau Institute of Central Nervous System Regeneration, Jinan University, Guangzhou, China
| | - Sensen Zhang
- Guangdong-Hongkong-Macau Institute of Central Nervous System Regeneration, Jinan University, Guangzhou, China
| | - Haiyang Cheng
- Guangdong-Hongkong-Macau Institute of Central Nervous System Regeneration, Jinan University, Guangzhou, China
| | - Kin Chiu
- Department of Ophthalmology, LKF Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China.,State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Hong Kong SAR, China
| | - Ying Xu
- Guangdong-Hongkong-Macau Institute of Central Nervous System Regeneration, Jinan University, Guangzhou, China.,Key Laboratory of Central Nervous System Regeneration, Jinan University, Ministry of Education, Guangzhou, China.,Co-Innovation Center of Neuroregeneration, Nantong University, Jiangsu, China
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20
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Cao KJ, Kim JH, Kroeger H, Gaffney PM, Lin JH, Sigurdson CJ, Yang J. ARCAM-1 Facilitates Fluorescence Detection of Amyloid-Containing Deposits in the Retina. Transl Vis Sci Technol 2021; 10:5. [PMID: 34096989 PMCID: PMC8185402 DOI: 10.1167/tvst.10.7.5] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Purpose To investigate the use of an amyloid-targeting fluorescent probe, ARCAM-1, to identify amyloid-containing deposits in the retina of a transgenic mouse model of Alzheimer's disease (AD) and in human postmortem AD patients. Methods Aged APP/PS1 transgenic AD and wild-type (WT) mice were given an intraperitoneal (IP) injection of ARCAM-1 and their retinas imaged in vivo using a fluorescence ophthalmoscope. Eyes were enucleated and dissected for ex vivo inspection of retinal amyloid deposits. Additionally, formalin-fixed eyes from human AD and control patients were dissected, and the retinas were stained using ARCAM-1 or with an anti-amyloid-β antibody. Confocal microscopy was used to image amyloid-containing deposits stained with ARCAM-1 or with immunostaining. Results Four out of eight APP/PS1 mice showed the presence of amyloid aggregates in the retina during antemortem imaging. Retinas from three human AD patients stained with ARCAM-1 showed an apparent increased density of fluorescently labeled amyloid-containing deposits compared to the retinas from two healthy, cognitively normal (CN) patients. Immunolabeling confirmed the presence of amyloid deposits in both the retinal neuronal layers and in retinal vasculature. Conclusions ARCAM-1 facilitates antemortem detection of amyloid aggregates in the retina of a mouse model for AD, and postmortem detection of amyloid-containing deposits in human retinal tissues from AD patients. These results support the hypothesis of AD pathology manifesting in the eye and highlight a novel area for fluorophore development for the optical detection of retinal amyloid in AD patients. Translational Relevance This paper represents an initial examination for potential translation of an amyloid-targeting fluorescent probe to a retinal imaging agent for aiding in the diagnosis of Alzheimer's disease.
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Affiliation(s)
- Kevin J Cao
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA, USA
| | - John H Kim
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA, USA
| | - Heike Kroeger
- Departments of Pathology and Medicine, University of California, San Diego, La Jolla, CA, USA.,Department of Cellular Biology, Franklin College of Arts and Sciences, University of Georgia, Athens, GA, USA
| | - Patricia M Gaffney
- Departments of Pathology and Medicine, University of California, San Diego, La Jolla, CA, USA.,Department of Disease Investigations, San Diego Zoo Wildlife Alliance, San Diego, CA, USA
| | - Jonathan H Lin
- Departments of Pathology and Medicine, University of California, San Diego, La Jolla, CA, USA.,Departments of Pathology and Byers Eye Institute, Stanford University, Palo Alto, CA, USA
| | - Christina J Sigurdson
- Departments of Pathology and Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Jerry Yang
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA, USA
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21
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Guo L, Ravindran N, Shamsher E, Hill D, Cordeiro MF. Retinal Changes in Transgenic Mouse Models of Alzheimer's Disease. Curr Alzheimer Res 2021; 18:89-102. [PMID: 33855942 DOI: 10.2174/1567205018666210414113634] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2020] [Revised: 02/09/2021] [Accepted: 04/05/2021] [Indexed: 11/22/2022]
Abstract
Alzheimer's disease (AD) is a neurodegenerative disorder, the most common form of dementia. AD is characterised by amyloid-β (Aβ) plaques and neurofibrillary tangles (NFT) in the brain, in association with neuronal loss and synaptic failure, causing cognitive deficits. Accurate and early diagnosis is currently unavailable in lifespan, hampering early intervention of potential new treatments. Visual deficits have been well documented in AD patients, and the pathological changes identified in the brain are also believed to be found in the retina, an integral part of the central nervous system. Retinal changes can be detected by real-time non-invasive imaging, due to the transparent nature of the ocular media, potentially allowing an earlier diagnosis as well as monitoring disease progression and treatment outcome. Animal models are essential for AD research, and this review has a focus on retinal changes in various transgenic AD mouse models with retinal imaging and immunohistochemical analysis as well as therapeutic effects in those models. We also discuss the limitations of transgenic AD models in clinical translations.
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Affiliation(s)
- Li Guo
- Glaucoma & Retinal Neurodegeneration Research Group, Institute of Ophthalmology, University College London, London, United Kingdom
| | - Nivedita Ravindran
- Glaucoma & Retinal Neurodegeneration Research Group, Institute of Ophthalmology, University College London, London, United Kingdom
| | - Ehtesham Shamsher
- Glaucoma & Retinal Neurodegeneration Research Group, Institute of Ophthalmology, University College London, London, United Kingdom
| | - Daniel Hill
- Glaucoma & Retinal Neurodegeneration Research Group, Institute of Ophthalmology, University College London, London, United Kingdom
| | - M Francesca Cordeiro
- Glaucoma & Retinal Neurodegeneration Research Group, Institute of Ophthalmology, University College London, London, United Kingdom
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22
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Kuo S, Chio C, Yeh C, Ma J, Liu W, Lin M, Lin K, Chang C. Mesenchymal stem cell-conditioned medium attenuates the retinal pathology in amyloid-β-induced rat model of Alzheimer's disease: Underlying mechanisms. Aging Cell 2021; 20:e13340. [PMID: 33783931 PMCID: PMC8135003 DOI: 10.1111/acel.13340] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 12/08/2020] [Accepted: 02/14/2021] [Indexed: 12/11/2022] Open
Abstract
Amyloid‐beta (Aβ) oligomer is known to contribute to the pathophysiology of age‐related macular degeneration. Herein, we aimed to elucidate the in vivo and in vitro effects of Aβ1‐42 application on retinal morphology in rats. Our in vivo studies revealed that intracerebroventricular administration of Aβ1‐42 oligomer caused dysmorphological changes in both retinal ganglion cells and retinal pigment epithelium. In addition, in vitro studies revealed that ARPE‐19 cells following Aβ1‐42 oligomer application had decreased viability along with apoptosis and decreased expression of the tight junction proteins, increased expression of both phosphor‐AKT and phosphor‐GSK3β and decreased expression of both SIRT1 and β‐catenin. Application of conditioned medium (CM) obtained from mesenchymal stem cells (MSC) protected against Aβ1‐42 oligomer‐induced retinal pathology in both rats and ARPE‐19 cells. In order to explore the potential role of peptides secreted from the MSCs, we applied mass spectrometry to compare the peptidomics profiles of the MSC‐CM. Gene ontology enrichment analysis and String analysis were performed to explore the differentially expressed peptides by predicting the functions of their precursor proteins. Bioinformatics analysis showed that 3‐8 out of 155–163 proteins in the MSC‐CM maybe associated with SIRT1/pAKT/pGSK3β/β‐catenin, tight junction proteins, and apoptosis pathway. In particular, the secretomes information on the MSC‐CM may be helpful for the prevention and treatment of retinal pathology in age‐related macular degeneration.
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Affiliation(s)
- Shu‐Chun Kuo
- Department of Ophthalmology Chi Mei Medical Center Tainan Taiwan
- Department of Optometry Chung Hwa University of Medical Technology Tainan Taiwan
| | - Chung‐Ching Chio
- Division of Neurosurgery Department of Surgery Chi Mei Medical Center Tainan Taiwan
| | - Chao‐Hung Yeh
- Department of Optometry Chung Hwa University of Medical Technology Tainan Taiwan
- Division of Neurosurgery Department of Surgery Chi Mei Medical Center Tainan Taiwan
| | - Jui‐Ti Ma
- Department of Medical Research Chi Mei Medical Center Tainan Taiwan
| | - Wen‐Pin Liu
- Department of Medical Research Chi Mei Medical Center Tainan Taiwan
| | - Mao‐Tsun Lin
- Department of Medical Research Chi Mei Medical Center Tainan Taiwan
| | - Kao‐Chang Lin
- Department of Holistic Care Chi Mei Medical Center Tainan Taiwan
- Department of Neurology Chi Mei Medical Center Tainan Taiwan
| | - Ching‐Ping Chang
- Department of Medical Research Chi Mei Medical Center Tainan Taiwan
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23
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Ferreira H, Martins J, Moreira PI, Ambrósio AF, Castelo-Branco M, Serranho P, Bernardes R. Longitudinal normative OCT retinal thickness data for wild-type mice, and characterization of changes in the 3×Tg-AD mice model of Alzheimer's disease. Aging (Albany NY) 2021; 13:9433-9454. [PMID: 33799308 PMCID: PMC8064224 DOI: 10.18632/aging.202916] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2020] [Accepted: 03/23/2021] [Indexed: 11/25/2022]
Abstract
Mice are widely used as models for many diseases, including eye and neurodegenerative diseases. However, there is a lack of normative data for retinal thickness over time, especially at young ages. In this work, we present a normative thickness database from one to four-months-old, for nine layers/layer-aggregates, including the total retinal thickness, obtained from the segmentation of spectral-domain optical coherence tomography (SD-OCT) data from the C57BL6/129S mouse strain. Based on fifty-seven mice, this normative database provides an opportunity to study the ageing of control mice and characterise disease models' ageing, such as the triple transgenic mouse model of Alzheimer's disease (3×Tg-AD) used in this work. We report thickness measurements, the differences in thickness per layer, demonstrate a nasal-temporal asymmetry, and the variation of thickness as a function to the distance to the optic disc centre. Significant differences were found between the transgenic group's thickness and the normative database for the entire period covered in this study. Even though it is well accepted that retinal nerve fibre layer (RNFL) thinning is a hallmark of neurodegeneration, our results show a thicker RNFL-GCL (RNFL-Ganglion cell layer) aggregate for the 3×Tg-AD mice until four-months-old.
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Affiliation(s)
- Hugo Ferreira
- University of Coimbra, Coimbra Institute for Biomedical Imaging and Translational Research (CIBIT), Institute for Nuclear Sciences Applied to Health (ICNAS), Coimbra, Portugal
| | - João Martins
- University of Coimbra, Coimbra Institute for Biomedical Imaging and Translational Research (CIBIT), Institute for Nuclear Sciences Applied to Health (ICNAS), Coimbra, Portugal.,University of Coimbra, Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine (FMUC), Coimbra, Portugal.,University of Coimbra, Center for Innovative Biomedicine and Biotechnology (CIBB), Coimbra, Portugal.,University of Coimbra, Clinical Academic Center of Coimbra (CACC), Faculty of Medicine (FMUC), Coimbra, Portugal
| | - Paula I Moreira
- University of Coimbra, Center for Innovative Biomedicine and Biotechnology (CIBB), Coimbra, Portugal.,University of Coimbra, Clinical Academic Center of Coimbra (CACC), Faculty of Medicine (FMUC), Coimbra, Portugal.,University of Coimbra, Laboratory of Physiology, Faculty of Medicine (FMUC), Coimbra, Portugal.,University of Coimbra, Center for Neuroscience and Cell Biology (CNC), Coimbra, Portugal
| | - António Francisco Ambrósio
- University of Coimbra, Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine (FMUC), Coimbra, Portugal.,University of Coimbra, Center for Innovative Biomedicine and Biotechnology (CIBB), Coimbra, Portugal.,University of Coimbra, Clinical Academic Center of Coimbra (CACC), Faculty of Medicine (FMUC), Coimbra, Portugal
| | - Miguel Castelo-Branco
- University of Coimbra, Coimbra Institute for Biomedical Imaging and Translational Research (CIBIT), Institute for Nuclear Sciences Applied to Health (ICNAS), Coimbra, Portugal.,University of Coimbra, Clinical Academic Center of Coimbra (CACC), Faculty of Medicine (FMUC), Coimbra, Portugal
| | - Pedro Serranho
- University of Coimbra, Coimbra Institute for Biomedical Imaging and Translational Research (CIBIT), Institute for Nuclear Sciences Applied to Health (ICNAS), Coimbra, Portugal.,Universidade Aberta, Department of Sciences and Technology, Lisboa, Portugal
| | - Rui Bernardes
- University of Coimbra, Coimbra Institute for Biomedical Imaging and Translational Research (CIBIT), Institute for Nuclear Sciences Applied to Health (ICNAS), Coimbra, Portugal.,University of Coimbra, Clinical Academic Center of Coimbra (CACC), Faculty of Medicine (FMUC), Coimbra, Portugal
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24
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Rodrigues-Neves AC, Carecho R, Correia SC, Carvalho C, Campos EJ, Baptista FI, Moreira PI, Ambrósio AF. Retina and Brain Display Early and Differential Molecular and Cellular Changes in the 3xTg-AD Mouse Model of Alzheimer's Disease. Mol Neurobiol 2021; 58:3043-3060. [PMID: 33606195 DOI: 10.1007/s12035-021-02316-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Accepted: 01/27/2021] [Indexed: 11/25/2022]
Abstract
The concept 'the retina as a window to the brain' has been increasingly explored in Alzheimer´s disease (AD) in recent years, since some patients present visual alterations before the first symptoms of dementia. The retina is an extension of the brain and can be assessed by noninvasive methods. However, assessing the retina for AD diagnosis is still a matter of debate. Using the triple transgenic mouse model of AD (3xTg-AD; males), this study was undertaken to investigate whether the retina and brain (hippocampus and cortex) undergo similar molecular and cellular changes during the early stages (4 and 8 months) of the pathology, and if the retina can anticipate the alterations occurring in the brain. We assessed amyloid-beta (Aβ) and hyperphosphorylated tau (p-tau) levels, barrier integrity, cell death, neurotransmitter levels, and glial changes. Overall, the retina, hippocampus, and cortex of 3xTg-AD are not significantly affected at these early stages. However, we detected a few differential changes in the retina and brain regions, and particularly a different profile in microglia branching in the retina and hippocampus, only at 4 months, where the number and length of the processes decreased in the retina and increased in the hippocampus. In summary, at the early stages of pathology, the retina, hippocampus, and cortex are not significantly affected but already present some molecular and cellular alterations. The retina did not mirror the changes detected in the brain, and these observations should be taking into account when using the retina as a potential diagnostic tool for AD.
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Affiliation(s)
- Ana Catarina Rodrigues-Neves
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, Coimbra, Portugal.,Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, Coimbra, Portugal.,Clinical Academic Center of Coimbra (CACC), Coimbra, Portugal
| | - Rafael Carecho
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, Coimbra, Portugal.,Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, Coimbra, Portugal.,Clinical Academic Center of Coimbra (CACC), Coimbra, Portugal
| | - Sónia Catarina Correia
- Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, Coimbra, Portugal.,Clinical Academic Center of Coimbra (CACC), Coimbra, Portugal.,Center for Neuroscience and Cell Biology (CNC), Coimbra, Portugal
| | - Cristina Carvalho
- Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, Coimbra, Portugal.,Clinical Academic Center of Coimbra (CACC), Coimbra, Portugal.,Center for Neuroscience and Cell Biology (CNC), Coimbra, Portugal
| | - Elisa Julião Campos
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, Coimbra, Portugal.,Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, Coimbra, Portugal.,Clinical Academic Center of Coimbra (CACC), Coimbra, Portugal.,Association for Innovation and Biomedical Research on Light and Image (AIBILI), Coimbra, Portugal
| | - Filipa Isabel Baptista
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, Coimbra, Portugal.,Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, Coimbra, Portugal.,Clinical Academic Center of Coimbra (CACC), Coimbra, Portugal
| | - Paula Isabel Moreira
- Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, Coimbra, Portugal.,Clinical Academic Center of Coimbra (CACC), Coimbra, Portugal.,Center for Neuroscience and Cell Biology (CNC), Coimbra, Portugal.,Institute of Physiology, Faculty of Medicine, University of Coimbra, Coimbra, Portugal
| | - António Francisco Ambrósio
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, Coimbra, Portugal. .,Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, Coimbra, Portugal. .,Clinical Academic Center of Coimbra (CACC), Coimbra, Portugal. .,Association for Innovation and Biomedical Research on Light and Image (AIBILI), Coimbra, Portugal.
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25
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Bevan RJ, Hughes TR, Williams PA, Good MA, Morgan BP, Morgan JE. Retinal ganglion cell degeneration correlates with hippocampal spine loss in experimental Alzheimer's disease. Acta Neuropathol Commun 2020; 8:216. [PMID: 33287900 PMCID: PMC7720390 DOI: 10.1186/s40478-020-01094-2] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Accepted: 11/23/2020] [Indexed: 02/06/2023] Open
Abstract
Neuronal dendritic and synaptic pruning are early features of neurodegenerative diseases, including Alzheimer’s disease. In addition to brain pathology, amyloid plaque deposition, microglial activation, and cell loss occur in the retinas of human patients and animal models of Alzheimer’s disease. Retinal ganglion cells, the output neurons of the retina, are vulnerable to damage in neurodegenerative diseases and are a potential opportunity for non-invasive clinical diagnosis and monitoring of Alzheimer’s progression. However, the extent of retinal involvement in Alzheimer’s models and how well this reflects brain pathology is unclear. Here we have quantified changes in retinal ganglion cells dendritic structure and hippocampal dendritic spines in three well-studied Alzheimer’s mouse models, Tg2576, 3xTg-AD and APPNL-G-F. Dendritic complexity of DiOlistically labelled retinal ganglion cells from retinal explants was reduced in all three models in an age-, gender-, and receptive field-dependent manner. DiOlistically labelled hippocampal slices showed spine loss in CA1 apical dendrites in all three Alzheimer’s models, mirroring the early stages of neurodegeneration as seen in the retina. Morphological classification showed that loss of thin spines predominated in all. The demonstration that retinal ganglion cells dendritic field reduction occurs in parallel with hippocampal dendritic spine loss in all three Alzheimer’s models provide compelling support for the use of retinal neurodegeneration. As retinal dendritic changes are within the optical range of current clinical imaging systems (for example optical coherence tomography), our study makes a case for imaging the retina as a non-invasive way to diagnose disease and monitor progression in Alzheimer’s disease.
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26
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Beard H, Chidlow G, Neumann D, Nazri N, Douglass M, Trim PJ, Snel MF, Casson RJ, Hemsley KM. Is the eye a window to the brain in Sanfilippo syndrome? Acta Neuropathol Commun 2020; 8:194. [PMID: 33203474 PMCID: PMC7672954 DOI: 10.1186/s40478-020-01070-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Accepted: 10/28/2020] [Indexed: 11/10/2022] Open
Abstract
Sanfilippo syndrome is an untreatable form of childhood-onset dementia. Whilst several therapeutic strategies are being evaluated in human clinical trials including i.v. delivery of AAV9-based gene therapy, an urgent unmet need is the availability of non-invasive, quantitative measures of neurodegeneration. We hypothesise that as part of the central nervous system, the retina may provide a window through which to 'visualise' degenerative lesions in brain and amelioration of them following treatment. This is reliant on the age of onset and the rate of disease progression being equivalent in retina and brain. For the first time we have assessed in parallel, the nature, age of onset and rate of retinal and brain degeneration in a mouse model of Sanfilippo syndrome. Significant accumulation of heparan sulphate and expansion of the endo/lysosomal system was observed in both retina and brain pre-symptomatically (by 3 weeks of age). Robust and early activation of micro- and macroglia was also observed in both tissues. There was substantial thinning of retina and loss of rod and cone photoreceptors by ~ 12 weeks of age, a time at which cognitive symptoms are noted. Intravenous delivery of a clinically relevant AAV9-human sulphamidase vector to neonatal mice prevented disease lesion appearance in retina and most areas of brain when assessed 6 weeks later. Collectively, the findings highlight the previously unrecognised early and significant involvement of retina in the Sanfilippo disease process, lesions that are preventable by neonatal treatment with AAV9-sulphamidase. Critically, our data demonstrate for the first time that the advancement of retinal disease parallels that occurring in brain in Sanfilippo syndrome, thus retina may provide an easily accessible neural tissue via which brain disease development and its amelioration with treatment can be monitored.
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27
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Alber J, Goldfarb D, Thompson LI, Arthur E, Hernandez K, Cheng D, DeBuc DC, Cordeiro F, Provetti-Cunha L, den Haan J, Van Stavern GP, Salloway SP, Sinoff S, Snyder PJ. Developing retinal biomarkers for the earliest stages of Alzheimer's disease: What we know, what we don't, and how to move forward. Alzheimers Dement 2020; 16:229-243. [PMID: 31914225 DOI: 10.1002/alz.12006] [Citation(s) in RCA: 80] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Revised: 10/23/2019] [Accepted: 11/18/2019] [Indexed: 12/12/2022]
Abstract
The last decade has seen a substantial increase in research focused on the identification, development, and validation of diagnostic and prognostic retinal biomarkers for Alzheimer's disease (AD). Sensitive retinal biomarkers may be advantageous because they are cost and time efficient, non-invasive, and present a minimal degree of patient risk and a high degree of accessibility. Much of the work in this area thus far has focused on distinguishing between symptomatic AD and/or mild cognitive impairment (MCI) and cognitively normal older adults. Minimal work has been done on the detection of preclinical AD, the earliest stage of AD pathogenesis characterized by the accumulation of cerebral amyloid absent clinical symptoms of MCI or dementia. The following review examines retinal structural changes, proteinopathies, and vascular alterations that have been proposed as potential AD biomarkers, with a focus on studies examining the earliest stages of disease pathogenesis. In addition, we present recommendations for future research to move beyond the discovery phase and toward validation of AD risk biomarkers that could potentially be used as a first step in a multistep screening process for AD risk detection.
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Affiliation(s)
- Jessica Alber
- Department of Biomedical and Pharmaceutical Sciences, University of Rhode Island, Kingston, Rhode Island, USA.,George and Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, Rhode Island, USA.,Department of Psychiatry and Human Behavior, Alpert Medical School of Brown University, Providence, Rhode Island, USA.,Butler Hospital Memory & Aging Program, Providence, Rhode Island, USA
| | | | - Louisa I Thompson
- Department of Psychiatry and Human Behavior, Alpert Medical School of Brown University, Providence, Rhode Island, USA.,Butler Hospital Memory & Aging Program, Providence, Rhode Island, USA
| | - Edmund Arthur
- Department of Biomedical and Pharmaceutical Sciences, University of Rhode Island, Kingston, Rhode Island, USA.,George and Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, Rhode Island, USA.,Butler Hospital Memory & Aging Program, Providence, Rhode Island, USA
| | | | - Derrick Cheng
- Alpert Medical School of Brown University, Providence, Rhode Island, USA
| | - Delia Cabrera DeBuc
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami, Miami, Florida, USA
| | - Francesca Cordeiro
- Imperial College London, London, UK.,University College London, London, UK.,Western Eye Hospital, London, UK
| | - Leonardo Provetti-Cunha
- Federal University of Juiz de Fora Medical School, Juiz de Fora, Minas Gerais, Brazil.,Juiz de Fora Eye Hospital, Juiz de Fora, Minas Gerais, Brazil.,University of São Paulo Medical School, São Paulo, Brazil
| | - Jurre den Haan
- Alzheimer Center Amsterdam, Department of Neurology, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam UMC, Amsterdam, the Netherlands
| | - Gregory P Van Stavern
- Department of Ophthalmology and Visual Sciences, Washington University in St. Louis School of Medicine, St. Louis, Missouri, USA
| | - Stephen P Salloway
- Department of Psychiatry and Human Behavior, Alpert Medical School of Brown University, Providence, Rhode Island, USA.,Butler Hospital Memory & Aging Program, Providence, Rhode Island, USA.,Department of Neurology, Alpert Medical School of Brown University, Providence, Rhode Island, USA
| | | | - Peter J Snyder
- Department of Biomedical and Pharmaceutical Sciences, University of Rhode Island, Kingston, Rhode Island, USA.,George and Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, Rhode Island, USA.,Department of Neurology and Department of Surgery (Ophthalmology), Alpert Medical School of Brown University, Providence, Rhode Island, USA
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28
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Wang Y, Liu X, Zhu L, Li W, Li Z, Lu X, Liu J, Hua W, Zhou Y, Gu Y, Zhu M. PG545 alleviates diabetic retinopathy by promoting retinal Müller cell autophagy to inhibit the inflammatory response. Biochem Biophys Res Commun 2020; 531:452-458. [PMID: 32800548 DOI: 10.1016/j.bbrc.2020.07.134] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Accepted: 07/29/2020] [Indexed: 10/23/2022]
Abstract
Diabetic retinopathy (DR), a major cause of blindness in working-age people, is attributed to the inflammatory response of retinal Müller cells (RMCs). The heparanase inhibitor PG545 plays proautophagic and anti-inflammatory roles. Intraperitoneal injection of PG545 at a dose of 20 mg/kg/d clearly reduced diabetes-induced body weight changes and fasting blood glucose levels in mice. PG545 also mitigated the reduction in retinal thickness and the formation of microaneurysms by promoting autophagy to inhibit the inflammatory response. In vitro, PG545 stimulated autophagy to downregulate the inflammatory response in high glucose-induced primary adult mouse RMCs. These data suggest that PG545 mitigates DR by promoting RMC autophagy to inhibit the inflammatory response.
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Affiliation(s)
- Ying Wang
- Department of Ophthalmology, Suzhou Municipal Hospital, The Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou, Jiangsu, China
| | - Xiaojuan Liu
- Department of Pathogen Biology, Medical College, Nantong University, Nantong, Jiangsu, China
| | - Linling Zhu
- Department of Ophthalmology, Lixiang Eye Hospital of Soochow University, Suzhou, Jiangsu, China
| | - Wendie Li
- Department of Ophthalmology, Ningbo Eye Hospital, Ningbo, China
| | - Zhizhe Li
- Department of Ophthalmology, Suzhou Municipal Hospital, The Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou, Jiangsu, China
| | - Xiting Lu
- Department of Ophthalmology, Suzhou Municipal Hospital, The Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou, Jiangsu, China
| | - Jie Liu
- Department of Ophthalmology, Suzhou Municipal Hospital, The Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou, Jiangsu, China
| | - Wenjuan Hua
- Department of Ophthalmology, Suzhou Municipal Hospital, The Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou, Jiangsu, China
| | - Yamei Zhou
- Department of Pathogen Biology, Medical College, Nantong University, Nantong, Jiangsu, China
| | - Yonghui Gu
- Department of Ophthalmology, Suzhou Municipal Hospital, The Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou, Jiangsu, China.
| | - Manhui Zhu
- Department of Ophthalmology, Lixiang Eye Hospital of Soochow University, Suzhou, Jiangsu, China.
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29
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Harper DJ, Augustin M, Lichtenegger A, Gesperger J, Himmel T, Muck M, Merkle CW, Eugui P, Kummer S, Woehrer A, Glösmann M, Baumann B. Retinal analysis of a mouse model of Alzheimer's disease with multicontrast optical coherence tomography. NEUROPHOTONICS 2020; 7:015006. [PMID: 32042855 PMCID: PMC6999077 DOI: 10.1117/1.nph.7.1.015006] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Accepted: 01/07/2020] [Indexed: 05/18/2023]
Abstract
Significance. Recent Alzheimer's disease (AD) patient studies have focused on retinal analysis, as the retina is the only part of the central nervous system that can be imaged noninvasively by optical methods. However, as this is a relatively new approach, the occurrence and role of retinal pathological features are still debated. Aim. The retina of an APP/PS1 mouse model was investigated using multicontrast optical coherence tomography (OCT) in order to provide a documentation of what was observed in both transgenic and wild-type mice. Approach. Both eyes of 24 APP/PS1 transgenic mice (age: 45 to 104 weeks) and 15 age-matched wild-type littermates were imaged by the custom-built OCT system. At the end of the experiment, retinas and brains were harvested from a subset of the mice (14 transgenic, 7 age-matched control) in order to compare the in vivo results to histological analysis and to quantify the cortical amyloid beta plaque load. Results. The system provided a combination of standard reflectivity data, polarization-sensitive data, and OCT angiograms. Qualitative and quantitative information from the resultant OCT images was extracted on retinal layer thickness and structure, presence of hyper-reflective foci, phase retardation abnormalities, and retinal vasculature. Conclusions. Although multicontrast OCT revealed abnormal structural properties and phase retardation signals in the retina of this APP/PS1 mouse model, the observations were very similar in transgenic and control mice.
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Affiliation(s)
- Danielle J. Harper
- Medical University of Vienna, Center for Medical Physics and Biomedical Engineering, Vienna, Austria
- Address all correspondence to Danielle J. Harper, E-mail:
| | - Marco Augustin
- Medical University of Vienna, Center for Medical Physics and Biomedical Engineering, Vienna, Austria
| | - Antonia Lichtenegger
- Medical University of Vienna, Center for Medical Physics and Biomedical Engineering, Vienna, Austria
| | - Johanna Gesperger
- Medical University of Vienna, Center for Medical Physics and Biomedical Engineering, Vienna, Austria
- General Hospital and Medical University of Vienna, Institute of Neurology, Vienna, Austria
| | - Tanja Himmel
- University of Veterinary Medicine, Institute of Pathology, Vienna, Austria
| | - Martina Muck
- Medical University of Vienna, Center for Medical Physics and Biomedical Engineering, Vienna, Austria
| | - Conrad W. Merkle
- Medical University of Vienna, Center for Medical Physics and Biomedical Engineering, Vienna, Austria
| | - Pablo Eugui
- Medical University of Vienna, Center for Medical Physics and Biomedical Engineering, Vienna, Austria
| | - Stefan Kummer
- University of Veterinary Medicine, Core Facility for Research and Technology, Vienna, Austria
| | - Adelheid Woehrer
- General Hospital and Medical University of Vienna, Institute of Neurology, Vienna, Austria
| | - Martin Glösmann
- University of Veterinary Medicine, Core Facility for Research and Technology, Vienna, Austria
| | - Bernhard Baumann
- Medical University of Vienna, Center for Medical Physics and Biomedical Engineering, Vienna, Austria
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30
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Liu Y, Wei W, Baazaoui N, Liu F, Iqbal K. Inhibition of AMD-Like Pathology With a Neurotrophic Compound in Aged Rats and 3xTg-AD Mice. Front Aging Neurosci 2019; 11:309. [PMID: 31803044 PMCID: PMC6877482 DOI: 10.3389/fnagi.2019.00309] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Accepted: 10/28/2019] [Indexed: 11/17/2022] Open
Abstract
Age-associated macular degeneration (AMD), which leads to loss of vision at its end stage, is one of the most common neurodegenerative diseases among the elderly. However, to date, no effective drug therapy is available for the prevention of AMD. Here, we report the occurrence of AMD pathology and its prevention by chronic treatment with the neurotrophic peptidergic compound P021, in aged rats and 3xTg-AD mice. We found photoreceptor degeneration, lipofuscin granules, vacuoles, and atrophy in retinal pigment epithelium (RPE) as well as Bruch’s membrane (BM) thickening; in aged rats, we even found rosette-like structure formation. Microgliosis and astrogliosis were observed in different retinal layers. In addition, we also found that total tau, phosphorylated tau, Aβ/APP, and VEGF were widely distributed in the sub-retina of aged rats and 3xTg mice. Importantly, chronic treatment with P021 for 3 months in rats and for 18 months in 3xTg mice ameliorated the pathological changes above. These findings indicate the therapeutic potential of P021 for prevention and treatment of AMD and retinal changes associated with aging and Alzheimer’s disease.
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Affiliation(s)
- Yinghua Liu
- Department of Neurochemistry, Inge Grundke-Iqbal Research Floor, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, NY, United States.,Department of Pharmacology, School of Pharmaceutical Sciences, Guangzhou Medical University, Guangzhou, China.,Key Laboratory of Molecular Clinical Pharmacology, Fifth Affiliated Hospital, Guangzhou Medical University, Guangzhou, China
| | - Wei Wei
- Department of Neurochemistry, Inge Grundke-Iqbal Research Floor, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, NY, United States.,Key Laboratory of State Administration of Traditional Chinese Medicine of China, Department of Pathophysiology, School of Medicine, Institute of Brain Research, Jinan University, Guangzhou, China
| | - Narjes Baazaoui
- Department of Neurochemistry, Inge Grundke-Iqbal Research Floor, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, NY, United States
| | - Fei Liu
- Department of Neurochemistry, Inge Grundke-Iqbal Research Floor, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, NY, United States
| | - Khalid Iqbal
- Department of Neurochemistry, Inge Grundke-Iqbal Research Floor, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, NY, United States
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31
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Chiquita S, Rodrigues-Neves AC, Baptista FI, Carecho R, Moreira PI, Castelo-Branco M, Ambrósio AF. The Retina as a Window or Mirror of the Brain Changes Detected in Alzheimer's Disease: Critical Aspects to Unravel. Mol Neurobiol 2019; 56:5416-5435. [PMID: 30612332 DOI: 10.1007/s12035-018-1461-6] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Accepted: 12/17/2018] [Indexed: 11/24/2022]
Abstract
Alzheimer's disease is the most frequent cause of dementia worldwide, representing a global health challenge, with a massive impact on the quality of life of Alzheimer's disease patients and their relatives. The diagnosis of Alzheimer's disease constitutes a real challenge, because the symptoms manifest years after the first degenerative changes occurring in the brain and the diagnosis is based on invasive and/or expensive techniques. Therefore, there is an urgent need to identify new reliable biomarkers to detect Alzheimer's disease at an early stage. Taking into account the evidence for visual deficits in Alzheimer's disease patients, sometimes even before the appearance of the first disease symptoms, and that the retina is an extension of the brain, the concept of the retina as a window to look into the brain or a mirror of the brain has received increasing interest in recent years. However, only a few studies have assessed the changes occurring in the retina and the brain at the same time points. Unlike previous reviews on this subject, which are mainly focused on brain changes, we organized this review by comprehensively summarizing findings related with structural, functional, cellular, and molecular parameters in the retina reported in both Alzheimer's disease patients and animal models. Moreover, we separated the studies that assessed only the retina, and those that assessed both the retina and brain, which are few but allow establishing correlations between the retina and brain. This review also highlights some inconsistent results in the literature as well as relevant missing gaps in this field.
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Affiliation(s)
- Samuel Chiquita
- iCBR, Coimbra Institute for Clinical and Biomedical Research, Faculty of Medicine, University of Coimbra, Coimbra, Portugal
- CNC.IBILI Consortium, University of Coimbra, Coimbra, Portugal
| | - Ana C Rodrigues-Neves
- iCBR, Coimbra Institute for Clinical and Biomedical Research, Faculty of Medicine, University of Coimbra, Coimbra, Portugal
- CNC.IBILI Consortium, University of Coimbra, Coimbra, Portugal
| | - Filipa I Baptista
- iCBR, Coimbra Institute for Clinical and Biomedical Research, Faculty of Medicine, University of Coimbra, Coimbra, Portugal
- CNC.IBILI Consortium, University of Coimbra, Coimbra, Portugal
| | - Rafael Carecho
- iCBR, Coimbra Institute for Clinical and Biomedical Research, Faculty of Medicine, University of Coimbra, Coimbra, Portugal
- CNC.IBILI Consortium, University of Coimbra, Coimbra, Portugal
| | - Paula I Moreira
- CNC.IBILI Consortium, University of Coimbra, Coimbra, Portugal
- CNC, Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
- Institute of Physiology, Faculty of Medicine, University of Coimbra, Coimbra, Portugal
| | - Miguel Castelo-Branco
- CNC.IBILI Consortium, University of Coimbra, Coimbra, Portugal
- CIBIT, Coimbra Institute for Biomedical Imaging and Translational Research, ICNAS, Institute of Nuclear Sciences Applied to Health, University of Coimbra, Coimbra, Portugal
| | - António F Ambrósio
- iCBR, Coimbra Institute for Clinical and Biomedical Research, Faculty of Medicine, University of Coimbra, Coimbra, Portugal.
- CNC.IBILI Consortium, University of Coimbra, Coimbra, Portugal.
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32
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Cerquera-Jaramillo MA, Nava-Mesa MO, González-Reyes RE, Tellez-Conti C, de-la-Torre A. Visual Features in Alzheimer's Disease: From Basic Mechanisms to Clinical Overview. Neural Plast 2018; 2018:2941783. [PMID: 30405709 PMCID: PMC6204169 DOI: 10.1155/2018/2941783] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Accepted: 08/07/2018] [Indexed: 12/16/2022] Open
Abstract
Alzheimer's disease (AD) is the leading cause of dementia worldwide. It compromises patients' daily activities owing to progressive cognitive deterioration, which has elevated direct and indirect costs. Although AD has several risk factors, aging is considered the most important. Unfortunately, clinical diagnosis is usually performed at an advanced disease stage when dementia is established, making implementation of successful therapeutic interventions difficult. Current biomarkers tend to be expensive, insufficient, or invasive, raising the need for novel, improved tools aimed at early disease detection. AD is characterized by brain atrophy due to neuronal and synaptic loss, extracellular amyloid plaques composed of amyloid-beta peptide (Aβ), and neurofibrillary tangles of hyperphosphorylated tau protein. The visual system and central nervous system share many functional components. Thus, it is plausible that damage induced by Aβ, tau, and neuroinflammation may be observed in visual components such as the retina, even at an early disease stage. This underscores the importance of implementing ophthalmological examinations, less invasive and expensive than other biomarkers, as useful measures to assess disease progression and severity in individuals with or at risk of AD. Here, we review functional and morphological changes of the retina and visual pathway in AD from pathophysiological and clinical perspectives.
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Affiliation(s)
| | - Mauricio O. Nava-Mesa
- Grupo de Investigación en Neurociencias (NeURos), Escuela de Medicina y Ciencias de la Salud, Universidad del Rosario, Bogotá, Colombia
| | - Rodrigo E. González-Reyes
- Grupo de Investigación en Neurociencias (NeURos), Escuela de Medicina y Ciencias de la Salud, Universidad del Rosario, Bogotá, Colombia
| | - Carlos Tellez-Conti
- Escuela Superior de Oftalmología-Instituto Barraquer de América, Bogotá, Colombia
| | - Alejandra de-la-Torre
- Grupo de Investigación en Neurociencias (NeURos), Escuela de Medicina y Ciencias de la Salud, Universidad del Rosario, Bogotá, Colombia
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33
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Rodriguez L, Mdzomba JB, Joly S, Boudreau-Laprise M, Planel E, Pernet V. Human Tau Expression Does Not Induce Mouse Retina Neurodegeneration, Suggesting Differential Toxicity of Tau in Brain vs. Retinal Neurons. Front Mol Neurosci 2018; 11:293. [PMID: 30197586 PMCID: PMC6117378 DOI: 10.3389/fnmol.2018.00293] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 08/03/2018] [Indexed: 02/03/2023] Open
Abstract
The implication of the microtubule-associated protein (MAP) Tau in the ocular manifestations of Alzheimer’s disease (AD) is elusive due to the lack of relevant animal model. However, signs of AD have been reported in the brain of transgenic mice expressing human Tau (hTau). To assess whether hTau is sufficient to induce AD pathogenesis in the retina as well, in the present study, we compared the retinal structure and function of KO mice deprived of Tau (mTKO) with those of transgenic mice expressing hTau. Our results revealed that hTau is particularly abundant in the inner nuclear layer (INL) cells of the retina. By electroretinogram (ERG) recording, light-induced retinal cell activation was not altered in hTau compared with mTKO littermates. Surprisingly, the ERG response mediated by cone photoreceptor stimulation was even stronger in hTau than in mTKO retinae. Immunofluorescent analysis of retinal sections allowed us to observe thicker inner retina in hTau than in mTKO eyes. By Western Blotting (WB), the upregulation of mTOR that was found in hTau mice may underlie retinal structure and function increases. Taken together, our results not only indicate that hTau expression is not toxic for retinal cells but they also suggest that it may play a positive role in visual physiology. The use of hTau may be envisaged to improve visual recovery in ocular diseases affecting the retinal function such as glaucoma or diabetic retinopathy.
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Affiliation(s)
- Léa Rodriguez
- CUO-Recherche, Centre de Recherche du CHU de Québec, Quebec, QC, Canada.,Département d'ophtalmologie, Faculté de Médecine, Université Laval, Quebec, QC, Canada
| | - Julius Baya Mdzomba
- CUO-Recherche, Centre de Recherche du CHU de Québec, Quebec, QC, Canada.,Département d'ophtalmologie, Faculté de Médecine, Université Laval, Quebec, QC, Canada
| | - Sandrine Joly
- CUO-Recherche, Centre de Recherche du CHU de Québec, Quebec, QC, Canada.,Département d'ophtalmologie, Faculté de Médecine, Université Laval, Quebec, QC, Canada
| | - Mélissa Boudreau-Laprise
- CUO-Recherche, Centre de Recherche du CHU de Québec, Quebec, QC, Canada.,Département d'ophtalmologie, Faculté de Médecine, Université Laval, Quebec, QC, Canada
| | - Emmanuel Planel
- Axe Neurosciences, Centre de Recherche du CHU de Québec, Quebec, QC, Canada.,Département de Psychiatrie et de Neurosciences, Faculté de Médecine, Université Laval, Quebec, QC, Canada
| | - Vincent Pernet
- CUO-Recherche, Centre de Recherche du CHU de Québec, Quebec, QC, Canada.,Département d'ophtalmologie, Faculté de Médecine, Université Laval, Quebec, QC, Canada
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34
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Ocular and Visual Manifestation of the Alzheimer’s Disease: A Literature Review, Part I: Animal Models and Human Pathology. ARCHIVES OF NEUROSCIENCE 2018. [DOI: 10.5812/ans.74225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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35
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Buccarello L, Sclip A, Sacchi M, Castaldo AM, Bertani I, ReCecconi A, Maestroni S, Zerbini G, Nucci P, Borsello T. The c-jun N-terminal kinase plays a key role in ocular degenerative changes in a mouse model of Alzheimer disease suggesting a correlation between ocular and brain pathologies. Oncotarget 2017; 8:83038-83051. [PMID: 29137322 PMCID: PMC5669948 DOI: 10.18632/oncotarget.19886] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Accepted: 07/12/2017] [Indexed: 11/25/2022] Open
Abstract
Recently a range of ocular manifestations such as retinal and lens amyloid-beta accumulation and retinal nerve fiber layer loss have been proposed as potential biomarkers in Alzheimer disease (AD). The TgCRND8 mouse model of AD exhibits age-dependent amyloid β (Aβ) oligomers accumulation and cognitive defects, amyloid plaques and hyperphosphorylated Tau deposition and inflammation. We proved the correlation between ocular pathologies and AD, observing increased levels of p-APP and p-Tau, accumulation of Aβ oligomers in the retina, eye, and optic nerve. The accumulation of amyloid markers was significantly stronger in the retinal ganglion cell (RGC) layer, suggesting that RGC might be more susceptible to degeneration. We detected a thinning of the RGC layer as well as RGC death in the retina of TgCRND8 mice, by using a combination of Optical Coherence Tomography (OCT), immunofluorescence, immunohistochemistry and Western blotting techniques. We proved for the first time the key role of C-Jun N-terminal Kinase (JNK) in the ocular degeneration. In support of this, the administration of the JNK inhibitor, D-JNKI1, was able to counteract the Aβ and p-Tau accumulation in the retina of TgCRND8 mice, and consequently reduce RGCs loss. These results confirm that degenerative changes in the retina/eye of AD mouse model mirrors the events observed in the brain parenchyma. Ocular changes can be detected by non-invasive imaging techniques, such as OCT, to study and test different therapeutic strategies against degenerative events associated to AD.
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Affiliation(s)
- Lucia Buccarello
- IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri", Milan, Italy
| | - Alessandra Sclip
- IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri", Milan, Italy
| | - Matteo Sacchi
- University Eye Clinic, San Giuseppe Hospital, University of Milan, Milan, Italy
| | | | - Ilaria Bertani
- IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri", Milan, Italy
| | - Andrea ReCecconi
- IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri", Milan, Italy
| | - Silvia Maestroni
- Unità Complicanze del Diabete, Istituto Scientifico San Raffaele, Milan, Italy
| | - Gianpaolo Zerbini
- Unità Complicanze del Diabete, Istituto Scientifico San Raffaele, Milan, Italy
| | - Paolo Nucci
- University Eye Clinic, San Giuseppe Hospital, University of Milan, Milan, Italy
| | - Tiziana Borsello
- IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri", Milan, Italy.,Department of Pharmacological and Biomolecular Sciences, University of Milan, Milan, Italy
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