Identification of novel modifiers of Aβ toxicity by transcriptomic analysis in the fruitfly

The strongest risk factor for developing Alzheimer's Disease (AD) is age. Here, we study the relationship between ageing and AD using a systems biology approach that employs a Drosophila (fruitfly) model of AD in which the flies overexpress the human A beta(42) peptide. We identified 712 genes that are differentially expressed between control and A beta-expressing flies. We further divided these genes according to how they change over the animal's lifetime and discovered that the AD-related gene expression signature is age-independent. We have identified a number of differentially expressed pathways that are likely to play an important role in the disease, including oxidative stress and innate immunity. In particular, we uncovered two new modifiers of the A beta phenotype, namely Sod3 and PGRP-SC1b.