Ibuprofen Suppresses Plaque Pathology and Inflammation in a Mouse Model for Alzheimer's Disease

TLDR

Alzheimer’s disease is marked by chronic neuroinflammation around amyloid plaques, and epidemiological data suggest NSAID use lowers AD risk. The study aimed to evaluate whether chronic oral ibuprofen could mitigate amyloid pathology and inflammation in a transgenic AD mouse model. Transgenic mice overexpressing a familial AD APP variant were given 375 ppm ibuprofen chow from 10 months of age for six months. Ibuprofen treatment significantly lowered IL‑1β, GFAP, amyloid plaque burden, SDS‑insoluble Aβ, dystrophic neurites, and microglial activation, indicating delayed AD pathology.

Abstract

The brain in Alzheimer's disease (AD) shows a chronic inflammatory response characterized by activated glial cells and increased expression of cytokines and complement factors surrounding amyloid deposits. Several epidemiological studies have demonstrated a reduced risk for AD in patients using nonsteroidal anti-inflammatory drugs (NSAIDs), prompting further inquiries about how NSAIDs might influence the development of AD pathology and inflammation in the CNS. We tested the impact of chronic orally administered ibuprofen, the most commonly used NSAID, in a transgenic model of AD displaying widespread microglial activation, age-related amyloid deposits, and dystrophic neurites. These mice were created by overexpressing a variant of the amyloid precursor protein found in familial AD. Transgene-positive (Tg+) and negative (Tg−) mice began receiving chow containing 375 ppm ibuprofen at 10 months of age, when amyloid plaques first appear, and were fed continuously for 6 months. This treatment produced significant reductions in final interleukin-1β and glial fibrillary acidic protein levels, as well as a significant diminution in the ultimate number and total area of β-amyloid deposits. Reductions in amyloid deposition were supported by ELISA measurements showing significantly decreased SDS-insoluble Aβ. Ibuprofen also decreased the numbers of ubiquitin-labeled dystrophic neurites and the percentage area per plaque of anti-phosphotyrosine-labeled microglia. Thus, the anti-inflammatory drug ibuprofen, which has been associated with reduced AD risk in human epidemiological studies, can significantly delay some forms of AD pathology, including amyloid deposition, when administered early in the disease course of a transgenic mouse model of AD.