Crystallin distribution in Bruch's membrane-choroid complex from AMD and age-matched donor eyes.

Crystallins were consistently found in a recent proteomic analysis of drusen from age-related macular degeneration (AMD) donor eyes. Here we compare the distribution of several crystallins in drusen, Bruch's membrane and choroid from AMD and non-AMD age-matched control eyes. Immunohistochemistry and Western blots of tissue samples were performed using antibodies to alphaA- and alphaB-crystallins. Bruch's membrane, drusen and the subjacent choroidal connective tissue from AMD tissues showed greater immunoreactivity for alphaA- and alphaB-crystallins than were observed in normal age-matched control tissues. Western blots also demonstrated more intense alphaA- and alphaB-crystallin signals from AMD tissues than were present in age-matched controls. These data indicate that alphaA- and alphaB-crystallins accumulate in Bruch's membrane and choroidal connective tissues to a greater degree in AMD than in normal aging. These findings suggest that the accumulation of these small heat shock proteins at this critical interface below the RPE reflects a disease-related stress response manifested during the progression of AMD.