Similarities Between Alzheimer's Disease and Glaucoma

Abstract

Purpose: : To determine whether presenilin participates in the optic nerve changes early after steroid-induced intraocular pressure (IOP) elevation in cows. To determine whether presenilin expression changes in the DBA/2 mouse retina with age.

Methods: : Adult female Braford cows were subjected to uniocular treatment with prednisolone acetate TID for a period of 6 weeks causing IOP elevation for a period of 2-3 weeks. Proteins were extracted from the optic nerve heads of ocular hypertensive and contralateral control eyes and subjected to immunoblotting using a presenilin-specific antibody. Fixed and paraffin-embedded nerves were also used for immunohistochemistry. Young pre-pathologic (3 month old) and aged glaucomatous (9 month old) DBA2 mice were also used. Eyes were fixed and subjected to immunohistochemical analysis. Presenilin immunoreactivity in the retina was compared between eyes of young (pre-pathologic) and aged mice.

Results: : The optic nerves of bovine eyes with high IOP showed significantly greater presenilin immunoreactivity as compared to contralateral controls. Aged glaucomatous DBA/2 mouse retinas exhibited a greater presenilin immunoreactivity as compared to the retinas of young DBA/2 mice. Most of the presenilin observed in aged DBA/2 retinas was localized by immunohistochemistry in the inner retina in a pattern consistent with presence of the protein in the Müller cell layer.

Conclusions: : Presenilin is upregulated in the bovine optic nerve early after IOP elevation. It is also upregulated in the retina of murine experimental glaucoma. Upregulation of presenilin (molecule implicated in Alzheimer’s pathology) suggests that there maybe similarities between Alzheimer’s disease and glaucoma and that presenilin participates in the retinal and optic nerve pathophysiology of glaucoma.

Keywords: immunohistochemistry • optic nerve • retina