The University of Southampton
University of Southampton Institutional Repository

A mouse model to study Aβ-driven pathology in the ageing retina

A mouse model to study Aβ-driven pathology in the ageing retina
A mouse model to study Aβ-driven pathology in the ageing retina
Purpose : The Alzheimer’s-linked Amyloid beta (Aβ) peptide is reported to be deposited in aged retinas. Aβ has been implicated in key stages of Age-related Macular Degeneration (AMD), yet its role remains poorly understood. Here we employ a mouse model to study the in-vivo effects of Aβ to delineate its mechanisms of action and to understand how Aβ triggers/drives retinal pathology with age.Methods : Aβ was characterised by negative stain TEM and immunogold labelling. C57BL/6 mice were subretinally injected with 3µL of oligomeric Aβ1-42 (625nM, n=5) or vehicle control (n=3). At 8 days post-injection eyes were enucleated, OCT-embedded and cryosectioned at 16µM intervals for histological analysis. H&E staining and confocal immunofluorescence analysed retinal morphology in response to Aβ exposure and reported Aβ localisation. Exclusion criteria included a 200µM radius from the injection site to omit areas of mechanical trauma. Morphometric analysis was performed blind using OlyVIA and ImageJ. Data is expressed as means ± SEM with a statistical significance of *P ≤ 0.05.Results : TEM and Dot Blot assay enabled us to identify a window in which Aβ is reported to be most toxic. Fundus images showed large areas of pathology in Aβ exposed mice (9582 ± 4831) compared to controls (48.33 ± 8.97) which were indistinguishable from non-injected littermates, p=0.12. Serial line scans of Aβ injected mice revealed a 2-fold increase in RPE hypopigmentation associated with photoreceptor outer segment (POS) loss, RPE disorganisation and RPE hypertrophy compared to controls. Similarly, confocal data showed POS and inner segment disorganisation compared to well-preserved retinal architecture in control retinas. Aβ was detected in multiple retinal locations including POS, the RPE/choroid interface and the outer and inner plexiform layers.Conclusions : Our findings demonstrate that subretinal Aβ injections faithfully recapitulate key features of early AMD including dysfunctional RPE and damaged photoreceptors. Critically, we found no obvious indication of apoptosis or disruption of the blood-retinal barrier indicating gradual cellular impairment over time. Previously published literature showing static images of Abeta in human post-mortem eyes tantalisingly correlates the presence of Aβ with high drusen-loads and AMD. Our model therefore represents a powerful tool to investigate the dynamic nature of Aβ-mediated pathology in living retinas.
0146-0404
6534
Lynn, Savannah
de0c4ec2-8a3c-4b16-9e47-ea13abc32a3b
Goverdhan, Srini
9ae32d5a-5c82-48a4-962d-1ed8acc3991e
Munday, Rosie
fbc25981-b45b-42da-9b86-86704cc1f8b1
Scott, Jennifer
bdc803de-3082-4727-a4ca-f5a1cf3fcfcc
Freeman, Thomas
a90df177-6a04-47fa-84d0-9566c30b8e1a
Johnston, David
b41163c9-b9d2-425c-af99-2a357204014e
Lotery, Andrew
5ecc2d2d-d0b4-468f-ad2c-df7156f8e514
Ratnayaka, J. Arjuna
002499b8-1a9f-45b6-9539-5ac145799dfd
Lynn, Savannah
de0c4ec2-8a3c-4b16-9e47-ea13abc32a3b
Goverdhan, Srini
9ae32d5a-5c82-48a4-962d-1ed8acc3991e
Munday, Rosie
fbc25981-b45b-42da-9b86-86704cc1f8b1
Scott, Jennifer
bdc803de-3082-4727-a4ca-f5a1cf3fcfcc
Freeman, Thomas
a90df177-6a04-47fa-84d0-9566c30b8e1a
Johnston, David
b41163c9-b9d2-425c-af99-2a357204014e
Lotery, Andrew
5ecc2d2d-d0b4-468f-ad2c-df7156f8e514
Ratnayaka, J. Arjuna
002499b8-1a9f-45b6-9539-5ac145799dfd

Lynn, Savannah, Goverdhan, Srini, Munday, Rosie, Scott, Jennifer, Freeman, Thomas, Johnston, David, Lotery, Andrew and Ratnayaka, J. Arjuna (2016) A mouse model to study Aβ-driven pathology in the ageing retina. Investigative Ophthalmology & Visual Science, 57 (12), 6534.

Record type: Meeting abstract

Abstract

Purpose : The Alzheimer’s-linked Amyloid beta (Aβ) peptide is reported to be deposited in aged retinas. Aβ has been implicated in key stages of Age-related Macular Degeneration (AMD), yet its role remains poorly understood. Here we employ a mouse model to study the in-vivo effects of Aβ to delineate its mechanisms of action and to understand how Aβ triggers/drives retinal pathology with age.Methods : Aβ was characterised by negative stain TEM and immunogold labelling. C57BL/6 mice were subretinally injected with 3µL of oligomeric Aβ1-42 (625nM, n=5) or vehicle control (n=3). At 8 days post-injection eyes were enucleated, OCT-embedded and cryosectioned at 16µM intervals for histological analysis. H&E staining and confocal immunofluorescence analysed retinal morphology in response to Aβ exposure and reported Aβ localisation. Exclusion criteria included a 200µM radius from the injection site to omit areas of mechanical trauma. Morphometric analysis was performed blind using OlyVIA and ImageJ. Data is expressed as means ± SEM with a statistical significance of *P ≤ 0.05.Results : TEM and Dot Blot assay enabled us to identify a window in which Aβ is reported to be most toxic. Fundus images showed large areas of pathology in Aβ exposed mice (9582 ± 4831) compared to controls (48.33 ± 8.97) which were indistinguishable from non-injected littermates, p=0.12. Serial line scans of Aβ injected mice revealed a 2-fold increase in RPE hypopigmentation associated with photoreceptor outer segment (POS) loss, RPE disorganisation and RPE hypertrophy compared to controls. Similarly, confocal data showed POS and inner segment disorganisation compared to well-preserved retinal architecture in control retinas. Aβ was detected in multiple retinal locations including POS, the RPE/choroid interface and the outer and inner plexiform layers.Conclusions : Our findings demonstrate that subretinal Aβ injections faithfully recapitulate key features of early AMD including dysfunctional RPE and damaged photoreceptors. Critically, we found no obvious indication of apoptosis or disruption of the blood-retinal barrier indicating gradual cellular impairment over time. Previously published literature showing static images of Abeta in human post-mortem eyes tantalisingly correlates the presence of Aβ with high drusen-loads and AMD. Our model therefore represents a powerful tool to investigate the dynamic nature of Aβ-mediated pathology in living retinas.

Full text not available from this repository.

More information

Published date: 1 September 2016

Identifiers

Local EPrints ID: 423104
URI: https://eprints.soton.ac.uk/id/eprint/423104
ISSN: 0146-0404
PURE UUID: 6d6c3b82-c1bf-4107-b511-e36fe25f1b23
ORCID for Savannah Lynn: ORCID iD orcid.org/0000-0003-2513-3144
ORCID for David Johnston: ORCID iD orcid.org/0000-0001-6703-6014
ORCID for Andrew Lotery: ORCID iD orcid.org/0000-0001-5541-4305
ORCID for J. Arjuna Ratnayaka: ORCID iD orcid.org/0000-0002-1027-6938

Catalogue record

Date deposited: 14 Aug 2018 16:30
Last modified: 14 Mar 2019 01:44

Export record

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of https://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×