Genetic variation in Aquaporin-4 moderates the relationship between sleep and brain A?-amyloid burden.

ABSTRACT: The glymphatic system is postulated to be a mechanism of brain A?-amyloid clearance and to be most effective during sleep. Ablation of the astrocytic end-feet expressed water-channel protein, Aquaporin-4, in mice, results in impairment of this clearance mechanism and increased brain A?-amyloid deposition, suggesting that Aquaporin-4 plays a pivotal role in glymphatic function. Currently there is a paucity of literature regarding the impact of AQP4 genetic variation on sleep, brain A?-amyloid burden and their relationship to each other in humans. To address this a cross-sectional observational study was undertaken in cognitively normal older adults from the Australian Imaging, Biomarkers and Lifestyle (AIBL) study. Genetic variants in AQP4 were investigated with respect to self-reported Pittsburgh Sleep Quality Index sleep parameters, positron emission tomography derived brain A?-amyloid burden and whether these genetic variants moderated the sleep-A?-amyloid burden relationship. One AQP4 variant, rs72878776, was associated with poorer overall sleep quality, while several SNPs moderated the effect of sleep latency (rs491148, rs9951307, rs7135406, rs3875089, rs151246) and duration (rs72878776, rs491148 and rs2339214) on brain A?-amyloid burden. This study suggests that AQP4 genetic variation moderates the relationship between sleep and brain A?-amyloid burden, which adds weight to the proposed glymphatic system being a potential A?-amyloid clearance mechanism and suggests that AQP4 genetic variation may impair this function. Further, AQP4 genetic variation should be considered when interpreting sleep-A? relationships.

SUBMITTER: Rainey-Smith SR 

PROVIDER: S-EPMC5865132 | biostudies-literature | 2018 Feb

REPOSITORIES: biostudies-literature