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Yang Q, Liu L, He F, Zhao W, Chen Z, Wu X, Rao B, Lin X, Mao F, Qu J, Zhang J. Retinal ganglion cell type-specific expression of synuclein family members revealed by scRNA-sequencing. Int J Med Sci 2024; 21:1472-1490. [PMID: 38903914 PMCID: PMC11186421 DOI: 10.7150/ijms.95598] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2024] [Accepted: 04/30/2024] [Indexed: 06/22/2024] Open
Abstract
Synuclein family members (Snca, Sncb, and Scng) are expressed in the retina, but their precise locations and roles are poorly understood. We performed an extensive analysis of the single-cell transcriptome in healthy and injured retinas to investigate their expression patterns and roles. We observed the expression of all synuclein family members in retinal ganglion cells (RGCs), which remained consistent across species (human, mouse, and chicken). We unveiled differential expression of Snca across distinct clusters (highly expressed in most), while Sncb and Sncg displayed uniform expression across all clusters. Further, we observed a decreased expression in RGCs following traumatic axonal injury. However, the proportion of α-Syn-positive RGCs in all RGCs and α-Syn-positive intrinsically photosensitive retinal ganglion cells (ipRGCs) in all ipRGCs remained unaltered. Lastly, we identified changes in communication patterns preceding cell death, with particular significance in the pleiotrophin-nucleolin (Ptn-Ncl) and neural cell adhesion molecule signaling pathways, where communication differences were pronounced between cells with varying expression levels of Snca. Our study employs an innovative approach using scRNA-seq to characterize synuclein expression in health retinal cells, specifically focusing on RGC subtypes, advances our knowledge of retinal physiology and pathology.
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Affiliation(s)
- Qingwen Yang
- Laboratory of Retinal Physiology and Disease, School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, 325027, China
| | - Lin Liu
- Laboratory of Retinal Physiology and Disease, School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, 325027, China
| | - Fang He
- Laboratory of Retinal Physiology and Disease, School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, 325027, China
| | - Wenna Zhao
- Laboratory of Retinal Physiology and Disease, School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, 325027, China
| | - Zhongqun Chen
- Laboratory of Retinal Physiology and Disease, School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, 325027, China
| | - Xiaotian Wu
- Laboratory of Retinal Physiology and Disease, School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, 325027, China
| | - Bilin Rao
- State Key Laboratory of Ophthalmology, Optometry and Visual Science, Eye Hospital, Wenzhou Medical University, Wenzhou, 325027, China
- Laboratory of Retinal Physiology and Disease, School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, 325027, China
| | - Xin Lin
- State Key Laboratory of Ophthalmology, Optometry and Visual Science, Eye Hospital, Wenzhou Medical University, Wenzhou, 325027, China
- Laboratory of Retinal Physiology and Disease, School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, 325027, China
| | - Fangyuan Mao
- Alberta Institute, Wenzhou Medical University, Wenzhou, 325027, China
| | - Jia Qu
- State Key Laboratory of Ophthalmology, Optometry and Visual Science, Eye Hospital, Wenzhou Medical University, Wenzhou, 325027, China
| | - Jun Zhang
- State Key Laboratory of Ophthalmology, Optometry and Visual Science, Eye Hospital, Wenzhou Medical University, Wenzhou, 325027, China
- Laboratory of Retinal Physiology and Disease, School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, 325027, China
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Casciano F, Zauli E, Celeghini C, Caruso L, Gonelli A, Zauli G, Pignatelli A. Retinal Alterations Predict Early Prodromal Signs of Neurodegenerative Disease. Int J Mol Sci 2024; 25:1689. [PMID: 38338966 PMCID: PMC10855697 DOI: 10.3390/ijms25031689] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Revised: 01/25/2024] [Accepted: 01/27/2024] [Indexed: 02/12/2024] Open
Abstract
Neurodegenerative diseases are an increasingly common group of diseases that occur late in life with a significant impact on personal, family, and economic life. Among these, Alzheimer's disease (AD) and Parkinson's disease (PD) are the major disorders that lead to mild to severe cognitive and physical impairment and dementia. Interestingly, those diseases may show onset of prodromal symptoms early after middle age. Commonly, the evaluation of these neurodegenerative diseases is based on the detection of biomarkers, where functional and structural magnetic resonance imaging (MRI) have shown a central role in revealing early or prodromal phases, although it can be expensive, time-consuming, and not always available. The aforementioned diseases have a common impact on the visual system due to the pathophysiological mechanisms shared between the eye and the brain. In Parkinson's disease, α-synuclein deposition in the retinal cells, as well as in dopaminergic neurons of the substantia nigra, alters the visual cortex and retinal function, resulting in modifications to the visual field. Similarly, the visual cortex is modified by the neurofibrillary tangles and neuritic amyloid β plaques typically seen in the Alzheimer's disease brain, and this may reflect the accumulation of these biomarkers in the retina during the early stages of the disease, as seen in postmortem retinas of AD patients. In this light, the ophthalmic evaluation of retinal neurodegeneration could become a cost-effective method for the early diagnosis of those diseases, overcoming the limitations of functional and structural imaging of the deep brain. This analysis is commonly used in ophthalmic practice, and interest in it has risen in recent years. This review will discuss the relationship between Alzheimer's disease and Parkinson's disease with retinal degeneration, highlighting how retinal analysis may represent a noninvasive and straightforward method for the early diagnosis of these neurodegenerative diseases.
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Affiliation(s)
- Fabio Casciano
- Department of Translational Medicine and LTTA Centre, University of Ferrara, 44121 Ferrara, Italy
| | - Enrico Zauli
- Department of Translational Medicine, University of Ferrara, 44121 Ferrara, Italy
| | - Claudio Celeghini
- Department of Translational Medicine, University of Ferrara, 44121 Ferrara, Italy
| | - Lorenzo Caruso
- Department of Environment and Prevention Sciences, University of Ferrara, 44121 Ferrara, Italy
| | - Arianna Gonelli
- Department of Translational Medicine, University of Ferrara, 44121 Ferrara, Italy
| | - Giorgio Zauli
- Research Department, King Khaled Eye Specialistic Hospital, Riyadh 12329, Saudi Arabia
| | - Angela Pignatelli
- Department of Neuroscience and Rehabilitation, University of Ferrara, 44124 Ferrara, Italy
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Tran KKN, Wong VHY, Vessey KA, Finkelstein DI, Bui BV, Nguyen CTO. Levodopa Rescues Retinal Function in the Transgenic A53T Alpha-Synuclein Model of Parkinson's Disease. Biomedicines 2024; 12:130. [PMID: 38255235 PMCID: PMC10813165 DOI: 10.3390/biomedicines12010130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Revised: 12/11/2023] [Accepted: 01/05/2024] [Indexed: 01/24/2024] Open
Abstract
BACKGROUND Loss of substantia nigra dopaminergic cells and alpha-synuclein (α-syn)-rich intraneuronal deposits within the central nervous system are key hallmarks of Parkinson's disease (PD). Levodopa (L-DOPA) is the current gold-standard treatment for PD. This study aimed to evaluate in vivo retinal changes in a transgenic PD model of α-syn overexpression and the effect of acute levodopa (L-DOPA) treatment. METHODS Anaesthetised 6-month-old mice expressing human A53T alpha-synuclein (HOM) and wildtype (WT) control littermates were intraperitoneally given 20 mg/kg L-DOPA (50 mg levodopa, 2.5 mg benserazide) or vehicle saline (n = 11-18 per group). In vivo retinal function (dark-adapted full-field ERG) and structure (optical coherence tomography, OCT) were recorded before and after drug treatment for 30 min. Ex vivo immunohistochemistry (IHC) on flat-mounted retina was conducted to assess tyrosine hydroxylase (TH) positive cell counts (n = 7-8 per group). RESULTS We found that photoreceptor (a-wave) and bipolar cell (b-wave) ERG responses (p < 0.01) in A53T HOM mice treated with L-DOPA grew in amplitude more (47 ± 9%) than WT mice (16 ± 9%) treated with L-DOPA, which was similar to the vehicle group (A53T HOM 25 ± 9%; WT 19 ± 7%). While outer retinal thinning (outer nuclear layer, ONL, and outer plexiform layer, OPL) was confirmed in A53T HOM mice (p < 0.01), L-DOPA did not have an ameliorative effect on retinal layer thickness. These findings were observed in the absence of changes to the number of TH-positive amacrine cells across experiment groups. Acute L-DOPA treatment transiently improves visual dysfunction caused by abnormal alpha-synuclein accumulation. CONCLUSIONS These findings deepen our understanding of dopamine and alpha-synuclein interactions in the retina and provide a high-throughput preclinical framework, primed for translation, through which novel therapeutic compounds can be objectively screened and assessed for fast-tracking PD drug discovery.
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Affiliation(s)
- Katie K. N. Tran
- Department of Optometry and Vision Sciences, The University of Melbourne, Parkville, VIC 3010, Australia; (K.K.N.T.); (V.H.Y.W.); (B.V.B.)
| | - Vickie H. Y. Wong
- Department of Optometry and Vision Sciences, The University of Melbourne, Parkville, VIC 3010, Australia; (K.K.N.T.); (V.H.Y.W.); (B.V.B.)
| | - Kirstan A. Vessey
- Department of Anatomy and Physiology, The University of Melbourne, Parkville, VIC 3010, Australia;
| | - David I. Finkelstein
- The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, VIC 3010, Australia;
| | - Bang V. Bui
- Department of Optometry and Vision Sciences, The University of Melbourne, Parkville, VIC 3010, Australia; (K.K.N.T.); (V.H.Y.W.); (B.V.B.)
| | - Christine T. O. Nguyen
- Department of Optometry and Vision Sciences, The University of Melbourne, Parkville, VIC 3010, Australia; (K.K.N.T.); (V.H.Y.W.); (B.V.B.)
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Camacho-Ordonez A, Cervantes-Arriaga A, Rodríguez-Violante M, Hernandez-Medrano AJ, Somilleda-Ventura SA, Pérez-Cano HJ, Nava-Castañeda Á, Guerrero-Berger O. Is there any correlation between alpha-synuclein levels in tears and retinal layer thickness in Parkinson's disease? Eur J Ophthalmol 2024; 34:252-259. [PMID: 37151018 DOI: 10.1177/11206721231173725] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
PURPOSE To determine the total alpha-synuclein (αSyn) reflex tears and its association with retinal layers thickness in Parkinson's disease (PD). METHODS Fifty-two eyes of 26 PD subjects and 52 eyes of age-and sex-matched healthy controls were included. Total αSyn in reflex tears was quantified using a human total αSyn enzyme-linked immunosorbent assay (ELISA) kit. The retinal thickness was evaluated with spectral-domain optical coherence tomography. The Movement Disorder Society-Unified Parkinsońs Disease Rating Scale (MDS-UPDRS), Non-Motor Symptoms Scale (NMSS), and Montreal Cognitive Assessment (MoCA) were used to assess motor, non-motor, and cognition. RESULTS In PD, total αSyn levels were increased compared to control subjects [1.76pg/mL (IQR 1.74-1.80) vs 1.73pg/mL (IQR 1.70-1.77), p < 0.004]. The nerve fiber layer, ganglion cell layer, internal plexiform layer, inner nuclear layer, and outer nuclear layer were thinner in PD in comparison with controls (p < 0.05). The outer plexiform layer and retinal pigment epithelium were thicker in PD (p < 0.05). The total αSyn levels positively correlated with the central volume of the inner nuclear layer (r = 0.357, p = 0.009). CONCLUSION Total αSyn reflex tear levels were increased in subjects with PD compared to controls. PD patients showed significant thinning of the inner retinal layers and thickening of outer retinal layers in comparison with controls. Total αSyn levels positively correlate with the central volume of the inner nuclear layer in PD. The combination of these biomarkers might have a possible role as a diagnostic tool in PD subjects.
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Affiliation(s)
- Azyadeh Camacho-Ordonez
- Neuro-ophthalmology Clinic, National Institute of Neurology and Neurosurgery, Mexico City, Mexico
- Anterior Segment Department, Fundacion Hospital Nuestra Señora de la Luz, IAP, Mexico City, Mexico
| | - Amin Cervantes-Arriaga
- Movement Disorder Clinic, National Institute of Neurology and Neurosurgery, Mexico City, Mexico
| | | | | | | | - Hector J Pérez-Cano
- Biomedical Research Center, Fundacion Hospital Nuestra Señora de la Luz, IAP, Mexico City, Mexico
| | - Ángel Nava-Castañeda
- Oculoplastics Department, Instituto de Oftalmologia Fundacion Conde de Valenciana IAP, Mexico City, Mexico
| | - Oscar Guerrero-Berger
- Anterior Segment Department, Fundacion Hospital Nuestra Señora de la Luz, IAP, Mexico City, Mexico
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Tu M, Yang S, Zeng L, Tan Y, Wang X. Retinal Vessel Density and Retinal Nerve Fiber Layer Thickness: A Prospective Study of One-Year Follow-Up of Patients with Parkinson's Disease. Int J Gen Med 2023; 16:3701-3712. [PMID: 37637710 PMCID: PMC10460207 DOI: 10.2147/ijgm.s426501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Accepted: 08/14/2023] [Indexed: 08/29/2023] Open
Abstract
Objective This study aims to compare the superficial vascular density from the macular region and the retinal nerve fiber layer (RNFL) thickness from the optic disc region between Parkinson's disease (PD) patients and controls. Methods We enrolled 56 idiopathic PD patients, totaling 86 eyes (PD group), and 45 sex- and age-matched healthy individuals, amounting to 90 eyes (control group). All subjects underwent examination using Zeiss wide-field vascular optical coherence tomography (OCT) (Cirrus HD-OCT 5000 Carl Zeiss, Germany), with a scanning range of 3 mm × 3 mm. We divided the images into two concentric circles with diameters of 1 mm and 3 mm at the macular fovea's center. Patients with PD were evaluated during their "off" phase using the Unified Parkinson's Disease Rating Scale III (UPDRS-III) and the Hoehn-Yahr scale (H-Y scale) to assess disease severity. Results The PD group exhibited significantly lower RNFL thickness (106.13±12.36 μm) compared to the control group (115.95±11.37 μm, P < 0.05). Similarly, the superficial retinal vessel length density was significantly lower in the PD group (20.7 [19.62, 22.17] mm-1) than in the control group (21.79±1.16 mm-1, P < 0.05). Correlation analysis revealed a negative correlation between RNFL thickness and UPDRS III score (rs=-0.036, P=0.037), and RNFL thickness tended to decrease with increasing severity of movement disorders. However, during the 6 and 12-month follow-up of some PD patients, we observed no progressive thinning of the RNFL or decreased superficial vascular density. Conclusion PD patients show retinal structural damage characterized by RNFL thinning and reduced retinal vessel length density. However, RNFL thickness did not correlate with vascular density nor did it decrease with the disease's progression.
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Affiliation(s)
- Min Tu
- People’s Hospital of Deyang City, Department of Neurology, Deyang, People’s Republic of China
- Affiliated Hospital of North Sichuan Medical College, Department of Neurology, Nanchong, People’s Republic of China
| | - Shuangfeng Yang
- People’s Hospital of Yuechi County, Department of Neurology, Guangan, People’s Republic of China
| | - Lan Zeng
- Affiliated Hospital of North Sichuan Medical College, Department of Neurology, Nanchong, People’s Republic of China
| | - Yuling Tan
- Affiliated Hospital of North Sichuan Medical College, Department of Neurology, Nanchong, People’s Republic of China
| | - Xiaoming Wang
- Affiliated Hospital of North Sichuan Medical College, Department of Neurology, Nanchong, People’s Republic of China
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Móvio MI, de Lima-Vasconcellos TH, Dos Santos GB, Echeverry MB, Colombo E, Mattos LS, Resende RR, Kihara AH. Retinal organoids from human-induced pluripotent stem cells: From studying retinal dystrophies to early diagnosis of Alzheimer's and Parkinson's disease. Semin Cell Dev Biol 2023; 144:77-86. [PMID: 36210260 DOI: 10.1016/j.semcdb.2022.09.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2022] [Revised: 09/15/2022] [Accepted: 09/17/2022] [Indexed: 11/18/2022]
Abstract
Human-induced pluripotent stem cells (hiPSCs) have provided new methods to study neurodegenerative diseases. In addition to their wide application in neuronal disorders, hiPSCs technology can also encompass specific conditions, such as inherited retinal dystrophies. The possibility of evaluating alterations related to retinal disorders in 3D organoids increases the truthfulness of in vitro models. Moreover, both Alzheimer's (AD) and Parkinson's disease (PD) have been described as causing early retinal alterations, generating beta-amyloid protein accumulation, or affecting dopaminergic amacrine cells. This review addresses recent advances and future perspectives obtained from in vitro modeling of retinal diseases, focusing on retinitis pigmentosa (RP). Additionally, we depicted the possibility of evaluating changes related to AD and PD in retinal organoids obtained from potential patients long before the onset of the disease, constituting a valuable tool in early diagnosis. With this, we pointed out prospects in the study of retinal dystrophies and early diagnosis of AD and PD.
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Affiliation(s)
- Marília Inês Móvio
- Laboratório de Neurogenética, Universidade Federal do ABC, São Bernardo do Campo, SP, Brazil
| | | | | | - Marcela Bermudez Echeverry
- Centro de Matemática, Computação e Cognição, Universidade Federal do ABC, São Bernardo do Campo, SP, Brazil
| | - Elisabetta Colombo
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Genoa, Italy; IRCCS Ospedale Policlinico San Martino, Genoa, Italy
| | - Leonardo S Mattos
- Biomedical Robotics Laboratory, Department of Advanced Robotics, Istituto Italiano di Tecnologia, Genoa, Italy
| | - Rodrigo Ribeiro Resende
- Department of Biochemistry and Immunology, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| | - Alexandre Hiroaki Kihara
- Laboratório de Neurogenética, Universidade Federal do ABC, São Bernardo do Campo, SP, Brazil; Centro de Matemática, Computação e Cognição, Universidade Federal do ABC, São Bernardo do Campo, SP, Brazil.
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Iemolo A, De Risi M, Giordano N, Torromino G, Somma C, Cavezza D, Colucci M, Mancini M, de Iure A, Granata R, Picconi B, Calabresi P, De Leonibus E. Synaptic mechanisms underlying onset and progression of memory deficits caused by hippocampal and midbrain synucleinopathy. NPJ Parkinsons Dis 2023; 9:92. [PMID: 37328503 DOI: 10.1038/s41531-023-00520-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Accepted: 05/15/2023] [Indexed: 06/18/2023] Open
Abstract
Cognitive deficits, including working memory, and visuospatial deficits are common and debilitating in Parkinson's disease. α-synucleinopathy in the hippocampus and cortex is considered as the major risk factor. However, little is known about the progression and specific synaptic mechanisms underlying the memory deficits induced by α-synucleinopathy. Here, we tested the hypothesis that pathologic α-Synuclein (α-Syn), initiated in different brain regions, leads to distinct onset and progression of the pathology. We report that overexpression of human α-Syn in the murine mesencephalon leads to late onset memory impairment and sensorimotor deficits accompanied by reduced dopamine D1 expression in the hippocampus. In contrast, human α-Syn overexpression in the hippocampus leads to early memory impairment, altered synaptic transmission and plasticity, and decreased expression of GluA1 AMPA-type glutamate receptors. These findings identify the synaptic mechanisms leading to memory impairment induced by hippocampal α-synucleinopathy and provide functional evidence of the major neuronal networks involved in disease progression.
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Affiliation(s)
- Attilio Iemolo
- Telethon Institute of Genetics and Medicine, Via dei Campi Flegrei 34, Pozzuoli, Naples, Italy
- Institute of Genetics and Biophysics (IGB), Consiglio Nazionale delle Ricerche (CNR), via Pietro Castellino 111, Naples, Italy
| | - Maria De Risi
- Telethon Institute of Genetics and Medicine, Via dei Campi Flegrei 34, Pozzuoli, Naples, Italy
- Institute of Biochemistry and Cell Biology, Consiglio Nazionale delle Ricerche (CNR), Via Ramarini 33, Monterotondo Scalo, Rome, Italy
| | - Nadia Giordano
- Telethon Institute of Genetics and Medicine, Via dei Campi Flegrei 34, Pozzuoli, Naples, Italy
| | - Giulia Torromino
- Institute of Biochemistry and Cell Biology, Consiglio Nazionale delle Ricerche (CNR), Via Ramarini 33, Monterotondo Scalo, Rome, Italy
- University of Naples Federico II, Department of Humanistic Studies, Naples, Italy
| | - Cristina Somma
- Telethon Institute of Genetics and Medicine, Via dei Campi Flegrei 34, Pozzuoli, Naples, Italy
| | - Diletta Cavezza
- Institute of Biochemistry and Cell Biology, Consiglio Nazionale delle Ricerche (CNR), Via Ramarini 33, Monterotondo Scalo, Rome, Italy
| | - Martina Colucci
- Telethon Institute of Genetics and Medicine, Via dei Campi Flegrei 34, Pozzuoli, Naples, Italy
- Institute of Genetics and Biophysics (IGB), Consiglio Nazionale delle Ricerche (CNR), via Pietro Castellino 111, Naples, Italy
| | - Maria Mancini
- Institute of Neuroscience (IN), Consiglio Nazionale delle Ricerche (CNR), via Raoul Follereau 3, Vedano al Lambro, Monza e Brianza, Italy
| | - Antonio de Iure
- Lab. Experimental Neurophysiology, IRCCS San Raffaele, Rome, 00166, Italy
| | - Rocco Granata
- Institute of Biochemistry and Cell Biology, Consiglio Nazionale delle Ricerche (CNR), Via Ramarini 33, Monterotondo Scalo, Rome, Italy
| | - Barbara Picconi
- Lab. Experimental Neurophysiology, IRCCS San Raffaele, Rome, 00166, Italy
- Telematic University San Raffaele, Rome, 00166, Italy
| | - Paolo Calabresi
- Neurological Clinic, Fondazione Policlinico Universitario Agostino Gemelli IRCCS, 00168, Rome, Italy
- Neurology, Department of Neuroscience, Faculty of Medicine, Università Cattolica del "Sacro Cuore", 00168, Rome, Italy
| | - Elvira De Leonibus
- Telethon Institute of Genetics and Medicine, Via dei Campi Flegrei 34, Pozzuoli, Naples, Italy.
- Institute of Genetics and Biophysics (IGB), Consiglio Nazionale delle Ricerche (CNR), via Pietro Castellino 111, Naples, Italy.
- Institute of Biochemistry and Cell Biology, Consiglio Nazionale delle Ricerche (CNR), Via Ramarini 33, Monterotondo Scalo, Rome, Italy.
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Pérez-Acuña D, Rhee KH, Shin SJ, Ahn J, Lee JY, Lee SJ. Retina-to-brain spreading of α-synuclein after intravitreal injection of preformed fibrils. Acta Neuropathol Commun 2023; 11:83. [PMID: 37210559 PMCID: PMC10199563 DOI: 10.1186/s40478-023-01575-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Accepted: 04/30/2023] [Indexed: 05/22/2023] Open
Abstract
Parkinson's disease (PD) is a neurodegenerative disorder characterized by the aggregation of misfolded α-synuclein and progressive spreading of the aggregates from a few discrete regions to wider brain regions. Although PD has been classically considered a movement disorder, a large body of clinical evidence has revealed the progressive occurrence of non-motor symptoms. Patients present visual symptoms in the initial stages of the disease, and accumulation of phospho-α-synuclein, dopaminergic neuronal loss, and retinal thinning has been observed in the retinas of PD patients. Based on such human data, we hypothesized that α-synuclein aggregation can initiate in the retina and spread to the brain through the visual pathway. Here, we demonstrate accumulation of α-synuclein in the retinas and brains of naive mice after intravitreal injection of α-synuclein preformed fibrils (PFFs). Histological analyses showed deposition of phospho-α-synuclein inclusions within the retina 2 months after injection, with increased oxidative stress leading to loss of retinal ganglion cells and dopaminergic dysfunction. In addition, we found accumulation of phospho-α-synuclein in cortical areas with accompanying neuroinflammation after 5 months. Collectively, our findings suggest that retinal synucleinopathy lesions initiated by intravitreal injection of α-synuclein PFFs spread to various brain regions through the visual pathway in mice.
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Affiliation(s)
- Dayana Pérez-Acuña
- Department of Biomedical Sciences, Seoul National University College of Medicine, 103 Daehak-Ro, Jongro-Gu, Seoul, 03080, Korea
| | - Ka Hyun Rhee
- Department of Biomedical Sciences, Seoul National University College of Medicine, 103 Daehak-Ro, Jongro-Gu, Seoul, 03080, Korea
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Soo Jean Shin
- Department of Biomedical Sciences, Seoul National University College of Medicine, 103 Daehak-Ro, Jongro-Gu, Seoul, 03080, Korea
| | - Jeeyun Ahn
- Department of Ophthalmology, College of Medicine, Seoul Metropolitan Government-Seoul National University Boramae Medical Center, Seoul National University, Seoul, South Korea
| | - Jee-Young Lee
- Department of Neurology, Seoul Metropolitan Government-Seoul National University Boramae Medical Center, Seoul National University College of Medicine, Seoul, South Korea
| | - Seung-Jae Lee
- Department of Biomedical Sciences, Seoul National University College of Medicine, 103 Daehak-Ro, Jongro-Gu, Seoul, 03080, Korea.
- Neuroscience Research Institute, Seoul National University College of Medicine, Seoul, South Korea.
- Convergence Research Center for Dementia, Seoul National University College of Medicine, Seoul, South Korea.
- Neuramedy, Seoul, South Korea.
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Tran KKN, Wong VHY, Hoang A, Finkelstein DI, Bui BV, Nguyen CTO. Retinal alpha-synuclein accumulation correlates with retinal dysfunction and structural thinning in the A53T mouse model of Parkinson's disease. Front Neurosci 2023; 17:1146979. [PMID: 37214398 PMCID: PMC10196133 DOI: 10.3389/fnins.2023.1146979] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2023] [Accepted: 04/17/2023] [Indexed: 05/24/2023] Open
Abstract
Abnormal alpha-synuclein (α-SYN) protein deposition has long been recognized as one of the pathological hallmarks of Parkinson's disease's (PD). This study considers the potential utility of PD retinal biomarkers by investigating retinal changes in a well characterized PD model of α-SYN overexpression and how these correspond to the presence of retinal α-SYN. Transgenic A53T homozygous (HOM) mice overexpressing human α-SYN and wildtype (WT) control littermates were assessed at 4, 6, and 14 months of age (male and female, n = 15-29 per group). In vivo retinal function (electroretinography, ERG) and structure (optical coherence tomography, OCT) were recorded, and retinal immunohistochemistry and western blot assays were performed to examine retinal α-SYN and tyrosine hydroxylase. Compared to WT controls, A53T mice exhibited reduced light-adapted (cone photoreceptor and bipolar cell amplitude, p < 0.0001) ERG responses and outer retinal thinning (outer plexiform layer, outer nuclear layer, p < 0.0001) which correlated with elevated levels of α-SYN. These retinal signatures provide a high throughput means to study α-SYN induced neurodegeneration and may be useful in vivo endpoints for PD drug discovery.
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Affiliation(s)
- Katie K. N. Tran
- Department of Optometry and Vision Sciences, The University of Melbourne, Parkville, VIC, Australia
| | - Vickie H. Y. Wong
- Department of Optometry and Vision Sciences, The University of Melbourne, Parkville, VIC, Australia
| | - Anh Hoang
- Department of Optometry and Vision Sciences, The University of Melbourne, Parkville, VIC, Australia
| | - David I. Finkelstein
- The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, VIC, Australia
| | - Bang V. Bui
- Department of Optometry and Vision Sciences, The University of Melbourne, Parkville, VIC, Australia
| | - Christine T. O. Nguyen
- Department of Optometry and Vision Sciences, The University of Melbourne, Parkville, VIC, Australia
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10
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Sanches ES, Boia R, Leitão RA, Madeira MH, Fontes-Ribeiro CA, Ambrósio AF, Fernandes R, Silva AP. Attention-Deficit/Hyperactivity Disorder Animal Model Presents Retinal Alterations and Methylphenidate Has a Differential Effect in ADHD versus Control Conditions. Antioxidants (Basel) 2023; 12:antiox12040937. [PMID: 37107312 PMCID: PMC10135983 DOI: 10.3390/antiox12040937] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 04/07/2023] [Accepted: 04/11/2023] [Indexed: 04/29/2023] Open
Abstract
Attention-Deficit/Hyperactivity Disorder (ADHD) is one of the most prevalent neurodevelopmental disorders. Interestingly, children with ADHD seem to experience more ophthalmologic abnormalities, and the impact of methylphenidate (MPH) use on retinal physiology remains unclear. Thus, we aimed to unravel the retina's structural, functional, and cellular alterations and the impact of MPH in ADHD versus the control conditions. For that, spontaneously hypertensive rats (SHR) and Wistar Kyoto rats (WKY) were used as animal models of ADHD and the controls, respectively. Animals were divided into four experimental groups as follows: WKY vehicle (Veh; tap water), WKY MPH (1.5 mg/kg/day), SHR Veh, SHR MPH. Individual administration was performed by gavage between P28-P55. Retinal physiology and structure were evaluated at P56 followed by tissue collection and analysis. The ADHD animal model presents the retinal structural, functional, and neuronal deficits, as well as the microglial reactivity, astrogliosis, blood-retinal barrier (BRB) hyperpermeability and a pro-inflammatory status. In this model, MPH had a beneficial effect on reducing microgliosis, BRB dysfunction, and inflammatory response, but did not correct the neuronal and functional alterations in the retina. Curiously, in the control animals, MPH showed an opposite effect since it impaired the retinal function, neuronal cells, and BRB integrity, and also promoted both microglia reactivity and upregulation of pro-inflammatory mediators. This study unveils the retinal alterations in ADHD and the opposite effects induced by MPH in the retina of ADHD and the control animal models.
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Affiliation(s)
- Eliane S Sanches
- Institute of Pharmacology and Experimental Therapeutics, Faculty of Medicine, University of Coimbra, 3000-548 Coimbra, Portugal
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, 3000-548 Coimbra, Portugal
- Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, 3004-531 Coimbra, Portugal
| | - Raquel Boia
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, 3000-548 Coimbra, Portugal
- Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, 3004-531 Coimbra, Portugal
- Clinical Academic Center of Coimbra (CACC), 3004-561 Coimbra, Portugal
| | - Ricardo A Leitão
- Institute of Pharmacology and Experimental Therapeutics, Faculty of Medicine, University of Coimbra, 3000-548 Coimbra, Portugal
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, 3000-548 Coimbra, Portugal
- Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, 3004-531 Coimbra, Portugal
| | - Maria H Madeira
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, 3000-548 Coimbra, Portugal
- Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, 3004-531 Coimbra, Portugal
| | - Carlos A Fontes-Ribeiro
- Institute of Pharmacology and Experimental Therapeutics, Faculty of Medicine, University of Coimbra, 3000-548 Coimbra, Portugal
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, 3000-548 Coimbra, Portugal
- Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, 3004-531 Coimbra, Portugal
- Clinical Academic Center of Coimbra (CACC), 3004-561 Coimbra, Portugal
| | - António Francisco Ambrósio
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, 3000-548 Coimbra, Portugal
- Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, 3004-531 Coimbra, Portugal
- Clinical Academic Center of Coimbra (CACC), 3004-561 Coimbra, Portugal
- Association for Innovation and Biomedical Research on Light and Image (AIBILI), 3000-548 Coimbra, Portugal
| | - Rosa Fernandes
- Institute of Pharmacology and Experimental Therapeutics, Faculty of Medicine, University of Coimbra, 3000-548 Coimbra, Portugal
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, 3000-548 Coimbra, Portugal
- Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, 3004-531 Coimbra, Portugal
- Clinical Academic Center of Coimbra (CACC), 3004-561 Coimbra, Portugal
- Association for Innovation and Biomedical Research on Light and Image (AIBILI), 3000-548 Coimbra, Portugal
| | - Ana Paula Silva
- Institute of Pharmacology and Experimental Therapeutics, Faculty of Medicine, University of Coimbra, 3000-548 Coimbra, Portugal
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, 3000-548 Coimbra, Portugal
- Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, 3004-531 Coimbra, Portugal
- Clinical Academic Center of Coimbra (CACC), 3004-561 Coimbra, Portugal
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11
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Sánchez-Sáez X, Ortuño-Lizarán I, Sánchez-Castillo C, Lax P, Cuenca N. Starburst amacrine cells, involved in visual motion perception, loose their synaptic input from dopaminergic amacrine cells and degenerate in Parkinson's disease patients. Transl Neurodegener 2023; 12:17. [PMID: 37013599 PMCID: PMC10071607 DOI: 10.1186/s40035-023-00348-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Accepted: 03/10/2023] [Indexed: 04/05/2023] Open
Abstract
BACKGROUND The main clinical symptoms characteristic of Parkinson's disease (PD) are bradykinesia, tremor, and other motor deficits. However, non-motor symptoms, such as visual disturbances, can be identified at early stages of the disease. One of these symptoms is the impairment of visual motion perception. Hence, we sought to determine if the starburst amacrine cells, which are the main cellular type involved in motion direction selectivity, are degenerated in PD and if the dopaminergic system is related to this degeneration. METHODS Human eyes from control (n = 10) and PD (n = 9) donors were available for this study. Using immunohistochemistry and confocal microscopy, we quantified starburst amacrine cell density (choline acetyltransferase [ChAT]-positive cells) and the relationship between these cells and dopaminergic amacrine cells (tyrosine hydroxylase-positive cells and vesicular monoamine transporter-2-positive presynapses) in cross-sections and wholemount retinas. RESULTS First, we found two different ChAT amacrine populations in the human retina that presented different ChAT immunoreactivity intensity and different expression of calcium-binding proteins. Both populations are affected in PD and their density is reduced compared to controls. Also, we report, for the first time, synaptic contacts between dopaminergic amacrine cells and ChAT-positive cells in the human retina. We found that, in PD retinas, there is a reduction of the dopaminergic synaptic contacts into ChAT cells. CONCLUSIONS Taken together, this work indicates degeneration of starburst amacrine cells in PD related to dopaminergic degeneration and that dopaminergic amacrine cells could modulate the function of starburst amacrine cells. Since motion perception circuitries are affected in PD, their assessment using visual tests could provide new insights into the diagnosis of PD.
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Grants
- FEDER-PID 2019-106230RB-I00 Ministerio de Ciencia e Innovación
- FEDER-PID 2019-106230RB-I00 Ministerio de Ciencia e Innovación
- FPU16/04114 Ministerio de Universidades
- RETICS-FEDER RD16/0008/0016 Instituto de Salud Carlos III
- IDIFEDER/2017/064 Conselleria de Innovación, Universidades, Ciencia y Sociedad Digital, Generalitat Valenciana
- PROMETEO/2021/024 Conselleria de Innovación, Universidades, Ciencia y Sociedad Digital, Generalitat Valenciana
- PROMETEO/2021/024 Conselleria de Innovación, Universidades, Ciencia y Sociedad Digital, Generalitat Valenciana
- APOSTD/2020/245 Conselleria de Innovación, Universidades, Ciencia y Sociedad Digital, Generalitat Valenciana
- 2019/00286/001 Es Retina Asturias
- 2019/00286/001 Es Retina Asturias
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Affiliation(s)
- Xavier Sánchez-Sáez
- Department of Physiology, Genetics and Microbiology, University of Alicante, San Vicente del Raspeig, Spain
| | - Isabel Ortuño-Lizarán
- Department of Physiology, Genetics and Microbiology, University of Alicante, San Vicente del Raspeig, Spain
| | - Carla Sánchez-Castillo
- Department of Physiology, Genetics and Microbiology, University of Alicante, San Vicente del Raspeig, Spain
| | - Pedro Lax
- Department of Physiology, Genetics and Microbiology, University of Alicante, San Vicente del Raspeig, Spain
- Alicante Institute for Health and Biomedical Research (ISABIAL), Alicante, Spain
| | - Nicolás Cuenca
- Department of Physiology, Genetics and Microbiology, University of Alicante, San Vicente del Raspeig, Spain.
- Alicante Institute for Health and Biomedical Research (ISABIAL), Alicante, Spain.
- Ramón Margalef Institute, University of Alicante, San Vicente del Raspeig, Spain.
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12
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The Role of Alpha-Synuclein Deposits in Parkinson's Disease: A Focus on the Human Retina. Int J Mol Sci 2023; 24:ijms24054391. [PMID: 36901822 PMCID: PMC10002434 DOI: 10.3390/ijms24054391] [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: 01/09/2023] [Revised: 02/16/2023] [Accepted: 02/21/2023] [Indexed: 02/25/2023] Open
Abstract
Parkinson's disease (PD) is a neurodegenerative condition characterized by the progressive deterioration of dopaminergic neurons in the central and peripheral autonomous system and the intraneuronal cytoplasmic accumulation of misfolded α-synuclein. The clinical features are the classic triad of tremor, rigidity, and bradykinesia and a set of non-motor symptoms, including visual deficits. The latter seems to arise years before the onset of motor symptoms and reflects the course of brain disease. The retina, by virtue of its similarity to brain tissue, is an excellent site for the analysis of the known histopathological changes of PD that occur in the brain. Numerous studies conducted on animal and human models of PD have shown the presence of α-synuclein in retinal tissue. Spectral-domain optical coherence tomography (SD-OCT) could be a technique that enables the study of these retinal alterations in vivo. The objective of this review is to describe recent evidence on the accumulation of native or modified α-synuclein in the human retina of patients with PD and its effects on the retinal tissue evaluated through SD-OCT.
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13
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Alves JN, Westner BU, Højlund A, Weil RS, Dalal SS. Structural and functional changes in the retina in Parkinson's disease. J Neurol Neurosurg Psychiatry 2023; 94:448-456. [PMID: 36806480 PMCID: PMC7614544 DOI: 10.1136/jnnp-2022-329342] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Accepted: 01/05/2023] [Indexed: 02/19/2023]
Abstract
Parkinson's disease is caused by degeneration of dopaminergic neurons, originating in the substantia nigra pars compacta and characterised by bradykinesia, rest tremor and rigidity. In addition, visual disorders and retinal abnormalities are often present and can be identified by decreased visual acuity, abnormal spatial contrast sensitivity or even difficulty in complex visual task completion. Because of their early onset in patients with de novo Parkinson's disease, the anatomical retinal changes and electrophysiological modification could be valuable markers even at early stages of the disease. However, due to the concomitant occurrence of normal ageing, the relevance and specificity of these predictive values can be difficult to interpret. This review examines retinal dysfunction arising in Parkinson's disease. We highlight the electrophysiological delays and decreased amplitude in the electroretinography recorded in patients and animal models. We relate this to coexisting anatomical changes such as retinal nerve fibre layer and macular thinning, measured using optical coherence tomography, and show that functional measures are more consistent overall than optical coherence-measured structural changes. We review the underlying chemical changes seen with loss of retinal dopaminergic neurons and the effect of levodopa treatment on the retina in Parkinson's disease. Finally, we consider whether retinal abnormalities in Parkinson's disease could have a role as potential markers of poorer outcomes and help stratify patients at early stages of the disease. We emphasise that retinal measures can be valuable, accessible and cost-effective methods in the early evaluation of Parkinson's disease pathogenesis with potential for patient stratification.
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Affiliation(s)
- Jordan N Alves
- Center of Functionally Integrative Neuroscience, Aarhus University, Aarhus, Denmark
| | - Britta U Westner
- Radboud University, Donders Institute for Brain, Cognition and Behaviours, Nijmegen, The Netherlands
| | - Andreas Højlund
- Department of Linguistics, Cognitive Science & Semiotics, Aarhus University, Aarhus, Denmark
| | - Rimona Sharon Weil
- Dementia Research Centre, University College London, London, UK.,Movement Disorders Consortium, University College London, London, UK.,Wellcome Centre for Human Neuroimaging, University College London, London, UK
| | - Sarang S Dalal
- Center of Functionally Integrative Neuroscience, Aarhus University, Aarhus, Denmark
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14
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Latina V, De Introna M, Caligiuri C, Loviglio A, Florio R, La Regina F, Pignataro A, Ammassari-Teule M, Calissano P, Amadoro G. Immunotherapy with Cleavage-Specific 12A12mAb Reduces the Tau Cleavage in Visual Cortex and Improves Visuo-Spatial Recognition Memory in Tg2576 AD Mouse Model. Pharmaceutics 2023; 15:pharmaceutics15020509. [PMID: 36839831 PMCID: PMC9965010 DOI: 10.3390/pharmaceutics15020509] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 01/25/2023] [Accepted: 01/31/2023] [Indexed: 02/05/2023] Open
Abstract
Tau-targeted immunotherapy is a promising approach for treatment of Alzheimer's disease (AD). Beyond cognitive decline, AD features visual deficits consistent with the manifestation of Amyloid β-protein (Aβ) plaques and neurofibrillary tangles (NFT) in the eyes and higher visual centers, both in animal models and affected subjects. We reported that 12A12-a monoclonal cleavage-specific antibody (mAb) which in vivo neutralizes the neurotoxic, N-terminal 20-22 kDa tau fragment(s)-significantly reduces the retinal accumulation in Tg(HuAPP695Swe)2576 mice of both tau and APP/Aβ pathologies correlated with local inflammation and synaptic deterioration. Here, we report the occurrence of N-terminal tau cleavage in the primary visual cortex (V1 area) and the beneficial effect of 12A12mAb treatment on phenotype-associated visuo-spatial deficits in this AD animal model. We found out that non-invasive administration of 12 A12mAb markedly reduced the pathological accumulation of both truncated tau and Aβ in the V1 area, correlated to significant improvement in visual recognition memory performance along with local increase in two direct readouts of cortical synaptic plasticity, including the dendritic spine density and the expression level of activity-regulated cytoskeleton protein Arc/Arg3.1. Translation of these findings to clinical therapeutic interventions could offer an innovative tau-directed opportunity to delay or halt the visual impairments occurring during AD progression.
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Affiliation(s)
- Valentina Latina
- European Brain Research Institute (EBRI), Viale Regina Elena 295, 00161 Rome, Italy
| | - Margherita De Introna
- Institute of Translational Pharmacology (IFT), National Research Council (CNR), Via Fosso del Cavaliere 100, 00133 Rome, Italy
- IRCCS Santa Lucia Foundation (FSL), Centro di Ricerca Europeo sul Cervello (CERC), Via Fosso del Fiorano 64-65, 00143 Rome, Italy
| | - Chiara Caligiuri
- IRCCS Santa Lucia Foundation (FSL), Centro di Ricerca Europeo sul Cervello (CERC), Via Fosso del Fiorano 64-65, 00143 Rome, Italy
| | - Alessia Loviglio
- European Brain Research Institute (EBRI), Viale Regina Elena 295, 00161 Rome, Italy
| | - Rita Florio
- European Brain Research Institute (EBRI), Viale Regina Elena 295, 00161 Rome, Italy
| | - Federico La Regina
- European Brain Research Institute (EBRI), Viale Regina Elena 295, 00161 Rome, Italy
| | - Annabella Pignataro
- Institute of Translational Pharmacology (IFT), National Research Council (CNR), Via Fosso del Cavaliere 100, 00133 Rome, Italy
- IRCCS Santa Lucia Foundation (FSL), Centro di Ricerca Europeo sul Cervello (CERC), Via Fosso del Fiorano 64-65, 00143 Rome, Italy
| | - Martine Ammassari-Teule
- IRCCS Santa Lucia Foundation (FSL), Centro di Ricerca Europeo sul Cervello (CERC), Via Fosso del Fiorano 64-65, 00143 Rome, Italy
- Institute of Biochemistry and Cell Biology (IBBC), National Research Council (CNR), Via Ercole Ramarini 32, 00015 Rome, Italy
| | - Pietro Calissano
- European Brain Research Institute (EBRI), Viale Regina Elena 295, 00161 Rome, Italy
| | - Giuseppina Amadoro
- European Brain Research Institute (EBRI), Viale Regina Elena 295, 00161 Rome, Italy
- Institute of Translational Pharmacology (IFT), National Research Council (CNR), Via Fosso del Cavaliere 100, 00133 Rome, Italy
- Correspondence: ; Tel.: +39-06-49255252
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15
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Dias SB, de Lemos L, Sousa L, Bitoque DB, Silva GA, Seabra MC, Tenreiro S. Age-Related Changes of the Synucleins Profile in the Mouse Retina. Biomolecules 2023; 13:biom13010180. [PMID: 36671565 PMCID: PMC9855780 DOI: 10.3390/biom13010180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Revised: 12/28/2022] [Accepted: 01/11/2023] [Indexed: 01/18/2023] Open
Abstract
Alpha-synuclein (aSyn) plays a central role in Parkinson's disease (PD) and has been extensively studied in the brain. This protein is part of the synuclein family, which is also composed of beta-synuclein (bSyn) and gamma-synuclein (gSyn). In addition to its neurotoxic role, synucleins have important functions in the nervous system, modulating synaptic transmission. Synucleins are expressed in the retina, but they have been poorly characterized. However, there is evidence that they are important for visual function and that they can play a role in retinal degeneration. This study aimed to profile synucleins in the retina of naturally aged mice and to correlate their patterns with specific retinal cells. With aging, we observed a decrease in the thickness of specific retinal layers, accompanied by an increase in glial reactivity. Moreover, the aSyn levels decreased, whereas bSyn increased with aging. The colocalization of both proteins was decreased in the inner plexiform layer (IPL) of the aged retina. gSyn presented an age-related decrease at the inner nuclear layer but was not significantly changed in the ganglion cell layer. The synaptic marker synaptophysin was shown to be preferentially colocalized with aSyn in the IPL with aging. At the same time, aSyn was found to exist at the presynaptic endings of bipolar cells and was affected by aging. Overall, this study suggests that physiological aging can be responsible for changes in the retinal tissue, implicating functional alterations that could affect synuclein family function.
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Affiliation(s)
- Sarah Batista Dias
- iNOVA4Health, NOVA Medical School|Faculdade de Ciências Médicas, NMS|FCM, Universidade Nova de Lisboa, 1169-056 Lisboa, Portugal
| | - Luísa de Lemos
- iNOVA4Health, NOVA Medical School|Faculdade de Ciências Médicas, NMS|FCM, Universidade Nova de Lisboa, 1169-056 Lisboa, Portugal
| | - Luís Sousa
- iNOVA4Health, NOVA Medical School|Faculdade de Ciências Médicas, NMS|FCM, Universidade Nova de Lisboa, 1169-056 Lisboa, Portugal
| | - Diogo B. Bitoque
- iNOVA4Health, NOVA Medical School|Faculdade de Ciências Médicas, NMS|FCM, Universidade Nova de Lisboa, 1169-056 Lisboa, Portugal
| | - Gabriela Araújo Silva
- iNOVA4Health, NOVA Medical School|Faculdade de Ciências Médicas, NMS|FCM, Universidade Nova de Lisboa, 1169-056 Lisboa, Portugal
| | - Miguel C. Seabra
- iNOVA4Health, NOVA Medical School|Faculdade de Ciências Médicas, NMS|FCM, Universidade Nova de Lisboa, 1169-056 Lisboa, Portugal
- UCL Institute of Ophthalmology, London EC1V 9EL, UK
| | - Sandra Tenreiro
- iNOVA4Health, NOVA Medical School|Faculdade de Ciências Médicas, NMS|FCM, Universidade Nova de Lisboa, 1169-056 Lisboa, Portugal
- Correspondence:
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16
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Carrella S, Di Guida M, Brillante S, Piccolo D, Ciampi L, Guadagnino I, Garcia Piqueras J, Pizzo M, Marrocco E, Molinari M, Petrogiannakis G, Barbato S, Ezhova Y, Auricchio A, Franco B, De Leonibus E, Surace EM, Indrieri A, Banfi S. miR-181a/b downregulation: a mutation-independent therapeutic approach for inherited retinal diseases. EMBO Mol Med 2022; 14:e15941. [PMID: 36194668 DOI: 10.15252/emmm.202215941] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 09/15/2022] [Accepted: 09/19/2022] [Indexed: 11/09/2022] Open
Abstract
Inherited retinal diseases (IRDs) are a group of diseases whose common landmark is progressive photoreceptor loss. The development of gene-specific therapies for IRDs is hampered by their wide genetic heterogeneity. Mitochondrial dysfunction is proving to constitute one of the key pathogenic events in IRDs; hence, approaches that enhance mitochondrial activities have a promising therapeutic potential for these conditions. We previously reported that miR-181a/b downregulation boosts mitochondrial turnover in models of primary retinal mitochondrial diseases. Here, we show that miR-181a/b silencing has a beneficial effect also in IRDs. In particular, the injection in the subretinal space of an adeno-associated viral vector (AAV) that harbors a miR-181a/b inhibitor (sponge) sequence (AAV2/8-GFP-Sponge-miR-181a/b) improves retinal morphology and visual function both in models of autosomal dominant (RHO-P347S) and of autosomal recessive (rd10) retinitis pigmentosa. Moreover, we demonstrate that miR-181a/b downregulation modulates the level of the mitochondrial fission-related protein Drp1 and rescues the mitochondrial fragmentation in RHO-P347S photoreceptors. Overall, these data support the potential use of miR-181a/b downregulation as an innovative mutation-independent therapeutic strategy for IRDs, which can be effective both to delay disease progression and to aid gene-specific therapeutic approaches.
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Affiliation(s)
- Sabrina Carrella
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy.,Ecosustainable Marine Biotechnology Department, Stazione Zoologica Anton Dohrn, Naples, Italy
| | - Martina Di Guida
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy.,Medical Genetics, Department of Precision Medicine, University of Campania "L. Vanvitelli", Naples, Italy
| | - Simona Brillante
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy
| | - Davide Piccolo
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy
| | - Ludovica Ciampi
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy
| | - Irene Guadagnino
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy.,Medical Genetics, Department of Precision Medicine, University of Campania "L. Vanvitelli", Naples, Italy
| | - Jorge Garcia Piqueras
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy.,Medical Genetics, Department of Precision Medicine, University of Campania "L. Vanvitelli", Naples, Italy
| | - Mariateresa Pizzo
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy
| | - Elena Marrocco
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy
| | - Marta Molinari
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy
| | - Georgios Petrogiannakis
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy.,Molecular Life Science, Department of Science and Environmental, Biological and Farmaceutical Technologies, University of Campania "Luigi Vanvitelli", Naples, Italy
| | - Sara Barbato
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy
| | - Yulia Ezhova
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy.,Molecular Life Science, Department of Science and Environmental, Biological and Farmaceutical Technologies, University of Campania "Luigi Vanvitelli", Naples, Italy
| | - Alberto Auricchio
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy.,Medical Genetics, Department of Advanced Biomedicine, University of Naples "Federico II", Naples, Italy
| | - Brunella Franco
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy.,Medical Genetics, Department of Translational Medical Science, University of Naples "Federico II", Naples, Italy.,Scuola Superiore Meridionale, School of Advanced Studies, Naples, Italy
| | - Elvira De Leonibus
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy.,Institute of Biochemistry and Cellular Biology (IBBC), National Research Council (CNR), Monterotondo, Rome, Italy
| | - Enrico Maria Surace
- Medical Genetics, Department of Translational Medical Science, University of Naples "Federico II", Naples, Italy
| | - Alessia Indrieri
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy.,Institute for Genetic and Biomedical Research (IRGB), National Research Council (CNR), Milan, Italy
| | - Sandro Banfi
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy.,Medical Genetics, Department of Precision Medicine, University of Campania "L. Vanvitelli", Naples, Italy
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17
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Zhang Y, Zhang X, Yue Y, Tian T. Retinal Degeneration: A Window to Understand the Origin and Progression of Parkinson’s Disease? Front Neurosci 2022; 15:799526. [PMID: 35185448 PMCID: PMC8854654 DOI: 10.3389/fnins.2021.799526] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Accepted: 12/09/2021] [Indexed: 11/13/2022] Open
Abstract
Parkinson’s disease (PD), the second most prevalent neurodegenerative disorder, manifests with motor and non-motor symptoms associated with two main pathological hallmarks, including the deterioration of dopaminergic cells and aggregation of alpha-synuclein. Yet, PD is a neurodegenerative process whose origin is uncertain and progression difficult to monitor and predict. Currently, a possibility is that PD may be secondary to long lasting peripheral affectations. In this regard, it has been shown that retinal degeneration is present in PD patients. Although it is unknown if retinal degeneration precedes PD motor symptoms, the possibility exists since degeneration of peripheral organs (e.g., olfaction, gut) have already been proven to antedate PD motor symptoms. In this paper, we explore this possibility by introducing the anatomical and functional relationship of retina and brain and providing an overview of the physiopathological changes of retinal structure and visual function in PD. On the basis of the current status of visual deficits in individuals with PD, we discuss the modalities and pathological mechanism of visual function or morphological changes in the retina and focus on the correlation between visual impairment and some representative structural features with clinical significance. To consider retinal degeneration as a contributor to PD origin and progress is important because PD evolution may be monitored and predicted by retinal studies through state-of-the-art techniques of the retina. It is significant to integrally understand the role of retinal morphological and functional changes in the neurodegenerative process for the diagnosis and therapeutic strategies of PD.
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Affiliation(s)
- Yanyan Zhang
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, China
- Department of Neurology, Yangpu Hospital, School of Medicine, Tongji University, Shanghai, China
| | - Xiaoguang Zhang
- Department of Neurology, Yangpu Hospital, School of Medicine, Tongji University, Shanghai, China
| | - Yunhua Yue
- Department of Neurology, Yangpu Hospital, School of Medicine, Tongji University, Shanghai, China
- *Correspondence: Yunhua Yue,
| | - Tian Tian
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, China
- Tian Tian,
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18
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Zhu Z, Hu W, Liao H, Tan Z, Chen Y, Shi D, Shang X, Zhang X, Huang Y, Yu H, Wang W, He M, Yang X. Association of visual impairment with risk for future Parkinson's disease. EClinicalMedicine 2021; 42:101189. [PMID: 34805812 PMCID: PMC8585627 DOI: 10.1016/j.eclinm.2021.101189] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 10/18/2021] [Accepted: 10/19/2021] [Indexed: 10/26/2022] Open
Abstract
BACKGROUND Although visual dysfunction is one of the most common non-motor symptoms among patients with Parkinson's disease (PD), it is not known whether visual impairment (VI) predates the onset of clinical PD. Therefore, we aim to examine the association of VI with the future development of PD in the UK Biobank Study. METHODS The UK Biobank Study is one of the largest cohort studies of health, enrolling over 500,000 participants aged 40-69 years between 2006 and 2010 across the UK. VI was defined as a habitual distance visual acuity (VA) worse than 0·3 logarithm of the minimum angle of resolution (LogMAR) in the better-seeing eye. Incident cases of PD were determined by self report data, hospital admission records or death records, whichever came first. Multivariable Cox proportional hazard regression models were used to investigate the association between VI and the risk of incident PD. FINDINGS A total of 117,050 participants were free of PD at the baseline assessment. During the median observation period of 5·96 (IQR: 5·77-6·23) years, PD occurred in 222 (0·19%) participants. Visually impaired participants were at a higher risk of developing PD than non-VI participants (p < 0·001). Compared with the non-VI group, the adjusted hazard ratio was 2·28 (95% CI 1·29-4·05, p = 0·005) in the VI group. These results were consistent in the sensitivity analysis, where incident PD cases diagnosed within one year after the baseline assessment were excluded. INTERPRETATION This cohort study found that VI was associated with an increased risk of incident PD, suggesting that VI may serve as a modifiable risk factor for prevention of future PD.
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Key Words
- Ageing
- BMI, body mass index
- CI, confidence intervals
- HR, hazard ratios
- IQR, interquartile range
- LogMAR, logarithm of the minimum angle of resolution
- NHS, National Health Service
- PD, Parkinson's disease
- PHQ-2, Patient Health Questionnaire-2
- PPV, positive predictive value
- Parkinson's disease
- SD, standard deviations
- VA, visual acuity
- VI, visual impairment
- Visual impairment
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Affiliation(s)
- Zhuoting Zhu
- Department of Ophthalmology, Guangdong Academy of Medical Sciences, Guangdong Provincial People's Hospital, Guangzhou, China
| | - Wenyi Hu
- Shanghai Jiaotong University, Shanghai, China
- Centre for Eye Research, University of Melbourne, East Melbourne, Victoria, Australia
| | - Huan Liao
- Neural Regeneration Group, Institute of Reconstructive Neurobiology, University of Bonn, Bonn, Germany
| | - Zachary Tan
- Centre for Eye Research, University of Melbourne, East Melbourne, Victoria, Australia
| | - Yifan Chen
- John Radcliffe Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | - Danli Shi
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Xianwen Shang
- Department of Ophthalmology, Guangdong Academy of Medical Sciences, Guangdong Provincial People's Hospital, Guangzhou, China
| | - Xueli Zhang
- Department of Ophthalmology, Guangdong Academy of Medical Sciences, Guangdong Provincial People's Hospital, Guangzhou, China
| | - Yu Huang
- Department of Ophthalmology, Guangdong Academy of Medical Sciences, Guangdong Provincial People's Hospital, Guangzhou, China
| | - Honghua Yu
- Department of Ophthalmology, Guangdong Academy of Medical Sciences, Guangdong Provincial People's Hospital, Guangzhou, China
| | - Wei Wang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
- Corresponding authors.
| | - Mingguang He
- Department of Ophthalmology, Guangdong Academy of Medical Sciences, Guangdong Provincial People's Hospital, Guangzhou, China
- Centre for Eye Research, University of Melbourne, East Melbourne, Victoria, Australia
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
- Centre for Eye Research, University of Melbourne, East Melbourne, Victoria, Australia
| | - Xiaohong Yang
- Department of Ophthalmology, Guangdong Academy of Medical Sciences, Guangdong Provincial People's Hospital, Guangzhou, China
- Corresponding authors.
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Hanna-Pladdy B, Pahwa R, Lyons KE. Dopaminergic Basis of Spatial Deficits in Early Parkinson's Disease. Cereb Cortex Commun 2021; 2:tgab042. [PMID: 34738086 DOI: 10.1093/texcom/tgab042] [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: 02/25/2021] [Revised: 06/06/2021] [Accepted: 06/07/2021] [Indexed: 11/14/2022] Open
Abstract
Dopaminergic mechanisms regulating cognitive and motor control were evaluated comparing visuoperceptual and perceptuomotor functions in Parkinson's disease (PD). The performance of PD patients (n = 40) was contrasted with healthy controls (n = 42) across two separate visits (on and off dopaminergic medications) on computerized tasks of perception and aiming to a target at variable stimulus lengths (4, 8, 12 cm). Novel visuoperceptual tasks of length equivalence and width interval estimations without motor demands were compared with tasks estimating spatial deviation in movement termination. The findings support the presence of spatial deficits in early PD, more pronounced with increased discrimination difficulty, and with shorter stimulus lengths of 4 cm for both visuoperceptual and perceptumotor functions. Dopaminergic medication had an adverse impact on visuoperceptual accuracy in particular for length equivalence estimations, in contrast with dopaminergic modulation of perceptuomotor functions that reduced angular displacements toward the target. The differential outcomes for spatial accuracy in perception versus movement termination in PD are consistent with involvement of the direct pathway and models of progressive loss of dopamine through corticostriatal loops. Future research should develop validated and sensitive standardized tests of perception and explore dopaminergic selective deficits in PD to optimize medication titration for motor and cognitive symptoms of the disease.
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Affiliation(s)
- B Hanna-Pladdy
- Center for Advanced Imaging Research (CAIR), Department of Diagnostic Radiology & Nuclear Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - R Pahwa
- Parkinson's Disease and Movement Disorder Center, Department of Neurology, University of Kansas Medical Center, Kansas City, KS 66160, USA
| | - K E Lyons
- Parkinson's Disease and Movement Disorder Center, Department of Neurology, University of Kansas Medical Center, Kansas City, KS 66160, USA
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20
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The Impact of SNCA Variations and Its Product Alpha-Synuclein on Non-Motor Features of Parkinson's Disease. Life (Basel) 2021; 11:life11080804. [PMID: 34440548 PMCID: PMC8401994 DOI: 10.3390/life11080804] [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: 07/02/2021] [Revised: 08/04/2021] [Accepted: 08/06/2021] [Indexed: 12/14/2022] Open
Abstract
Parkinson’s disease (PD) is a common and progressive neurodegenerative disease, caused by the loss of dopaminergic neurons in the substantia nigra pars compacta in the midbrain, which is clinically characterized by a constellation of motor and non-motor manifestations. The latter include hyposmia, constipation, depression, pain and, in later stages, cognitive decline and dysautonomia. The main pathological features of PD are neuronal loss and consequent accumulation of Lewy bodies (LB) in the surviving neurons. Alpha-synuclein (α-syn) is the main component of LB, and α-syn aggregation and accumulation perpetuate neuronal degeneration. Mutations in the α-syn gene (SNCA) were the first genetic cause of PD to be identified. Generally, patients carrying SNCA mutations present early-onset parkinsonism with severe and early non-motor symptoms, including cognitive decline. Several SNCA polymorphisms were also identified, and some of them showed association with non-motor manifestations. The functional role of these polymorphisms is only partially understood. In this review we explore the contribution of SNCA and its product, α-syn, in predisposing to the non-motor manifestations of PD.
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21
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Carrella S, Massa F, Indrieri A. The Role of MicroRNAs in Mitochondria-Mediated Eye Diseases. Front Cell Dev Biol 2021; 9:653522. [PMID: 34222230 PMCID: PMC8249810 DOI: 10.3389/fcell.2021.653522] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Accepted: 05/20/2021] [Indexed: 12/15/2022] Open
Abstract
The retina is among the most metabolically active tissues with high-energy demands. The peculiar distribution of mitochondria in cells of retinal layers is necessary to assure the appropriate energy supply for the transmission of the light signal. Photoreceptor cells (PRs), retinal pigment epithelium (RPE), and retinal ganglion cells (RGCs) present a great concentration of mitochondria, which makes them particularly sensitive to mitochondrial dysfunction. To date, visual loss has been extensively correlated to defective mitochondrial functions. Many mitochondrial diseases (MDs) show indeed neuro-ophthalmic manifestations, including retinal and optic nerve phenotypes. Moreover, abnormal mitochondrial functions are frequently found in the most common retinal pathologies, i.e., glaucoma, age-related macular degeneration (AMD), and diabetic retinopathy (DR), that share clinical similarities with the hereditary primary MDs. MicroRNAs (miRNAs) are established as key regulators of several developmental, physiological, and pathological processes. Dysregulated miRNA expression profiles in retinal degeneration models and in patients underline the potentiality of miRNA modulation as a possible gene/mutation-independent strategy in retinal diseases and highlight their promising role as disease predictive or prognostic biomarkers. In this review, we will summarize the current knowledge about the participation of miRNAs in both rare and common mitochondria-mediated eye diseases. Definitely, given the involvement of miRNAs in retina pathologies and therapy as well as their use as molecular biomarkers, they represent a determining target for clinical applications.
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Affiliation(s)
| | - Filomena Massa
- Telethon Institute of Genetics and Medicine, Naples, Italy
| | - Alessia Indrieri
- Telethon Institute of Genetics and Medicine, Naples, Italy.,Institute for Genetic and Biomedical Research, National Research Council (CNR), Milan, Italy
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22
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Bridi JC, Bereczki E, Smith SK, Poças GM, Kottler B, Domingos PM, Elliott CJ, Aarsland D, Hirth F. Presynaptic accumulation of α-synuclein causes synaptopathy and progressive neurodegeneration in Drosophila. Brain Commun 2021; 3:fcab049. [PMID: 33997781 PMCID: PMC8111063 DOI: 10.1093/braincomms/fcab049] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Revised: 02/13/2021] [Accepted: 02/15/2021] [Indexed: 11/13/2022] Open
Abstract
Alpha-synuclein (α-syn) mislocalization and accumulation in intracellular inclusions is the major pathological hallmark of degenerative synucleinopathies, including Parkinson's disease, Parkinson's disease with dementia and dementia with Lewy bodies. Typical symptoms are behavioural abnormalities including motor deficits that mark disease progression, while non-motor symptoms and synaptic deficits are already apparent during the early stages of disease. Synucleinopathies have therefore been considered synaptopathies that exhibit synaptic dysfunction prior to neurodegeneration. However, the mechanisms and events underlying synaptopathy are largely unknown. Here we investigated the cascade of pathological events underlying α-syn accumulation and toxicity in a Drosophila model of synucleinopathy by employing a combination of histological, biochemical, behavioural and electrophysiological assays. Our findings demonstrate that targeted expression of human α-syn leads to its accumulation in presynaptic terminals that caused downregulation of synaptic proteins, cysteine string protein, synapsin, and syntaxin 1A, and a reduction in the number of Bruchpilot puncta, the core component of the presynaptic active zone essential for its structural integrity and function. These α-syn-mediated presynaptic alterations resulted in impaired neuronal function, which triggered behavioural deficits in ageing Drosophila that occurred prior to progressive degeneration of dopaminergic neurons. Comparable alterations in presynaptic active zone protein were found in patient brain samples of dementia with Lewy bodies. Together, these findings demonstrate that presynaptic accumulation of α-syn impairs the active zone and neuronal function, which together cause synaptopathy that results in behavioural deficits and the progressive loss of dopaminergic neurons. This sequence of events resembles the cytological and behavioural phenotypes that characterise the onset and progression of synucleinopathies, suggesting that α-syn-mediated synaptopathy is an initiating cause of age-related neurodegeneration.
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Affiliation(s)
- Jessika C Bridi
- Department of Basic & Clinical Neuroscience, King's College London, Institute of Psychiatry, Psychology & Neuroscience, Maurice Wohl Clinical Neuroscience Institute, London SE5 9RX, UK
| | - Erika Bereczki
- Department of Neurobiology, Care Sciences and Society, Center for Alzheimer Research, Division of Neurogeriatrics, Karolinska Institutet, Novum, Stockholm 171 77, Sweden
| | - Saffron K Smith
- Department of Biology and York Biomedical Research Institute, University of York, York YO1 5DD, UK
| | - Gonçalo M Poças
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa (ITQB NOVA), Oeiras, Lisbon 2780-157, Portugal
- School of Biological Sciences, Monash University, Melbourne, VIC 34QP+JV, Australia
| | - Benjamin Kottler
- Department of Basic & Clinical Neuroscience, King's College London, Institute of Psychiatry, Psychology & Neuroscience, Maurice Wohl Clinical Neuroscience Institute, London SE5 9RX, UK
| | - Pedro M Domingos
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa (ITQB NOVA), Oeiras, Lisbon 2780-157, Portugal
| | - Christopher J Elliott
- Department of Biology and York Biomedical Research Institute, University of York, York YO1 5DD, UK
| | - Dag Aarsland
- Department of Old Age Psychiatry, Institute of Psychiatry Psychology and Neuroscience, King’s College London, London, UK
- Centre for Age-Related Diseases, Stavanger University Hospital, Stavanger 4068, Norway
| | - Frank Hirth
- Department of Basic & Clinical Neuroscience, King's College London, Institute of Psychiatry, Psychology & Neuroscience, Maurice Wohl Clinical Neuroscience Institute, London SE5 9RX, UK
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23
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Ortuño-Lizarán I, Sánchez-Sáez X, Lax P, Serrano GE, Beach TG, Adler CH, Cuenca N. Dopaminergic Retinal Cell Loss and Visual Dysfunction in Parkinson Disease. Ann Neurol 2020; 88:893-906. [PMID: 32881029 PMCID: PMC10005860 DOI: 10.1002/ana.25897] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Revised: 08/29/2020] [Accepted: 08/31/2020] [Indexed: 12/31/2022]
Abstract
OBJECTIVE Considering the demonstrated implication of the retina in Parkinson disease (PD) pathology and the importance of dopaminergic cells in this tissue, we aimed to analyze the state of the dopaminergic amacrine cells and some of their main postsynaptic neurons in the retina of PD. METHODS Using immunohistochemistry and confocal microscopy, we evaluated morphology, number, and synaptic connections of dopaminergic cells and their postsynaptic cells, AII amacrine and melanopsin-containing retinal ganglion cells, in control and PD eyes from human donors. RESULTS In PD, dopaminergic amacrine cell number was reduced between 58% and 26% in different retinal regions, involving a decline in the number of synaptic contacts with AII amacrine cells (by 60%) and melanopsin cells (by 35%). Despite losing their main synaptic input, AII cells were not reduced in number, but they showed cellular alterations compromising their adequate function: (1) a loss of mitochondria inside their lobular appendages, which may indicate an energetic failure; and (2) a loss of connexin 36, suggesting alterations in the AII coupling and in visual signal transmission from the rod pathway. INTERPRETATION The dopaminergic system impairment and the affection of the rod pathway through the AII cells may explain and be partially responsible for the reduced contrast sensitivity or electroretinographic response described in PD. Also, dopamine reduction and the loss of synaptic contacts with melanopsin cells may contribute to the melanopsin retinal ganglion cell loss previously described and to the disturbances in circadian rhythm and sleep reported in PD patients. These data support the idea that the retina reproduces brain neurodegeneration and is highly involved in PD pathology. ANN NEUROL 2020;88:893-906.
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Affiliation(s)
- Isabel Ortuño-Lizarán
- Department of Physiology, Genetics and Microbiology, University of Alicante, Alicante, Spain
| | - Xavier Sánchez-Sáez
- Department of Physiology, Genetics and Microbiology, University of Alicante, Alicante, Spain
| | - Pedro Lax
- Department of Physiology, Genetics and Microbiology, University of Alicante, Alicante, Spain
| | | | | | | | - Nicolás Cuenca
- Department of Physiology, Genetics and Microbiology, University of Alicante, Alicante, Spain
- Institute Ramón Margalef, University of Alicante, Alicante, Spain
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24
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Indrieri A, Pizzarelli R, Franco B, De Leonibus E. Dopamine, Alpha-Synuclein, and Mitochondrial Dysfunctions in Parkinsonian Eyes. Front Neurosci 2020; 14:567129. [PMID: 33192254 PMCID: PMC7604532 DOI: 10.3389/fnins.2020.567129] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 09/22/2020] [Indexed: 12/21/2022] Open
Abstract
Parkinson’s disease (PD) is characterized by motor dysfunctions including bradykinesia, tremor at rest and motor instability. These symptoms are associated with the progressive degeneration of dopaminergic neurons originating in the substantia nigra pars compacta and projecting to the corpus striatum, and by accumulation of cytoplasmic inclusions mainly consisting of aggregated alpha-synuclein, called Lewy bodies. PD is a complex, multifactorial disorder and its pathogenesis involves multiple pathways and mechanisms such as α-synuclein proteostasis, mitochondrial function, oxidative stress, calcium homeostasis, axonal transport, and neuroinflammation. Motor symptoms manifest when there is already an extensive dopamine denervation. There is therefore an urgent need for early biomarkers to apply disease-modifying therapeutic strategies. Visual defects and retinal abnormalities, including decreased visual acuity, abnormal spatial contrast sensitivity, color vision defects, or deficits in more complex visual tasks are present in the majority of PD patients. They are being considered for early diagnosis together with retinal imaging techniques are being considered as non-invasive biomarkers for PD. Dopaminergic cells can be found in the retina in a subpopulation of amacrine cells; however, the molecular mechanisms leading to visual deficits observed in PD patients are still largely unknown. This review provides a comprehensive analysis of the retinal abnormalities observed in PD patients and animal models and of the molecular mechanisms underlying neurodegeneration in parkinsonian eyes. We will review the role of α-synuclein aggregates in the retina pathology and/or in the onset of visual symptoms in PD suggesting that α-synuclein aggregates are harmful for the retina as well as for the brain. Moreover, we will summarize experimental evidence suggesting that the optic nerve pathology observed in PD resembles that seen in mitochondrial optic neuropathies highlighting the possible involvement of mitochondrial abnormalities in the development of PD visual defects. We finally propose that the eye may be considered as a complementary experimental model to identify possible novel disease’ pathways or to test novel therapeutic approaches for PD.
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Affiliation(s)
- Alessia Indrieri
- Telethon Institute of Genetics and Medicine, Pozzuoli, Italy.,Institute for Genetic and Biomedical Research, National Research Council, Milan, Italy
| | - Rocco Pizzarelli
- Center for Life Nanoscience, Istituto Italiano di Tecnologia, Rome, Italy
| | - Brunella Franco
- Telethon Institute of Genetics and Medicine, Pozzuoli, Italy.,Medical Genetics, Department of Translational Medical Science, University of Naples "Federico II", Naples, Italy
| | - Elvira De Leonibus
- Telethon Institute of Genetics and Medicine, Pozzuoli, Italy.,Institute of Biochemistry and Cellular Biology, National Research Council, Rome, Italy
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