Characterisation of amyloid-induced inflammatory responses in the rat retina

Amyloid-induced inflammation is thought to play a critical and early role in the pathophysiology of Alzheimer's disease. As such, robust models with relevant and accessible compartments that provide a means of assessing anti-inflammatory agents are essential for the development of therapeutic agents. In the present work, we have characterised the induction of inflammation in the rat retina following intravitreal administration of amyloid-beta protein (Aβ). Histology and mRNA endpoints in the retina demonstrate Aβ1-42-, but not Aβ42-1-, induced inflammatory responses characterised by increases in markers for microglia and astrocytes (ionised calcium-binding adaptor molecule 1 (iba-1), GFAP and nestin) and increases in mRNA for inflammatory cytokines and chemokines such as IL1-β, MIP1α and TNFα. Likewise, analysis of vitreal cytokines also revealed increases in inflammatory cytokines and chemokines, including IL1-β, MIP1α and MCP1, induced by Aβ1-42 but not Aβ42-1. This profile of pro-inflammatory gene and protein expression is consistent with that observed in the Alzheimer's disease brain and suggest that this preclinical model may provide a useful relevant tool in the development of anti-inflammatory approaches directed towards Alzheimer's disease therapy.