PICALM rescues glutamatergic neurotransmission, behavioural function and survival in a Drosophila model of A?42 toxicity.

ABSTRACT: Alzheimer's disease (AD) is the most common form of dementia and the most prevalent neurodegenerative disease. Genome-wide association studies have linked PICALM to AD risk. PICALM has been implicated in A?42 production and turnover, but whether it plays a direct role in modulating A?42 toxicity remains unclear. We found that increased expression of the Drosophila PICALM orthologue lap could rescue A?42 toxicity in an adult-onset model of AD, without affecting A?42 level. Imbalances in the glutamatergic system, leading to excessive, toxic stimulation, have been associated with AD. We found that A?42 caused the accumulation of presynaptic vesicular glutamate transporter (VGlut) and increased spontaneous glutamate release. Increased lap expression reversed these phenotypes back to control levels, suggesting that lap may modulate glutamatergic transmission. We also found that lap modulated the localization of amphiphysin (Amph), the homologue of another AD risk factor BIN1, and that Amph itself modulated postsynaptic glutamate receptor (GluRII) localization. We propose a model where PICALM modulates glutamatergic transmission, together with BIN1, to ameliorate synaptic dysfunction and disease progression.

SUBMITTER: Yu Y 

PROVIDER: S-EPMC7424762 | biostudies-literature | 2020 Aug

REPOSITORIES: biostudies-literature