Accelerated accumulation of retinal α-synuclein (pSer129) and tau, neuroinflammation, and autophagic dysregulation in a seeded mouse model of Parkinson's disease

Date
2019-01-01
Authors
Valentine, Rudy
Yu, Chenxu
Mammadova, Najiba
Summers, Corey
Kokemuller, Robyn
He, Qing
Ding, Shaowei
Baron, Thierry
Sakaguchi, Donald
Yu, Chenxu
Valentine, Rudy
Sakaguchi, Donald
Kanthasamy, Anumantha
Greenlee, Justin
West Greenlee, M. Heather
Major Professor
Advisor
Committee Member
Journal Title
Journal ISSN
Volume Title
Publisher
Altmetrics
Authors
Research Projects
Organizational Units
Biomedical Sciences
Organizational Unit
Mechanical Engineering
Organizational Unit
Immunobiology
Organizational Unit
Neuroscience
Organizational Unit
Kinesiology
Organizational Unit
Journal Issue
Series
Department
Biomedical SciencesMechanical EngineeringImmunobiologyNeuroscienceKinesiologyGenetics, Development and Cell BiologyAgricultural and Biosystems EngineeringImmunobiology
Abstract

Parkinson's disease (PD) is a neurodegenerative disorder characterized by accumulation of misfolded α-synuclein within the central nervous system (CNS). Visual problems in PD patients are common, although retinal pathology associated with PD is not well understood. The purpose of this study was to investigate retinal pathology in a transgenic mouse model (TgM83) expressing the human A53T α-synuclein mutation and assess the effect of α-synuclein “seeding” on the development of retinal pathology. Two-month-old TgM83 mice were intracerebrally inoculated with brain homogenate from old (12–18 months) TgM83 mice. Retinas were then analyzed at 5 months of age. We analyzed retinas from 5-month-old and 8-month-old uninoculated healthy TgM83 mice, and old (12–18 months) mice that were euthanized following the development of clinical signs. Retinas of B6C3H mice (genetic background of the TgM83 mouse) served as control. We used immunohistochemistry and western blot analysis to detect accumulation of α-synuclein, pTauThr231, inflammation, changes in macroautophagy, and cell death. Raman spectroscopy was used to test the potential to differentiate between retinal tissues of healthy mice and diseased mice. This work demonstrates retinal changes associated with the A53T mutation. Retinas of non-inoculated TgM83 mice had accumulation of α-synuclein, “pre-tangle” tau, activation of retinal glial cells, and photoreceptor cell loss by 8 months of age. The development of these changes is accelerated by inoculation with brain homogenate from clinically ill TgM83 mice. Compared to non-inoculated 5-month-old TgM83 mice, retinas of inoculated 5-month-old mice had increased accumulation of α-synuclein (pSer129) and pTauThr231 proteins, upregulated microglial activation, and dysregulated macroautophagy. Raman spectroscopic analysis was able to discriminate between healthy and diseased mice. This study describes retinal pathology resulting from the A53T mutation. We show that seeding with brain homogenates from old TgM83 mice accelerates retinal pathology. We demonstrate that Raman spectroscopy can be used to accurately identify a diseased retina based on its biochemical profile, and that α-synuclein accumulation may contribute to accumulation of pTauThr231 proteins, neuroinflammation, metabolic dysregulation, and photoreceptor cell death. Our work provides insight into retinal changes associated with Parkinson's disease, and may contribute to a better understanding of visual symptoms experienced by patients.

Comments

This article is published as Mammadova, Najiba, Corey M. Summers, Robyn D. Kokemuller, Qing He, Shaowei Ding, Thierry Baron, Chenxu Yu, Rudy J. Valentine, Donald S. Sakaguchi, Anumantha G. Kanthasamy, Justin J. Greenlee, and M. Heather West Greenlee. "Accelerated accumulation of retinal α-synuclein (pSer129) and tau, neuroinflammation, and autophagic dysregulation in a seeded mouse model of Parkinson's disease." Neurobiology of Disease 121 (2019): 1-16. DOI: 10.1016/j.nbd.2018.09.013.

Description
Keywords
Citation
DOI
Collections