Exploring the relationship between melanopsin gene variants, sleep, and markers of brain health

Abstract

INTRODUCTION: Melanopsin is a photopigment with roles in mediating sleep and circadian-related processes, which are often disrupted in Alzheimer's disease (AD). Melanopsin also impacts cognition and synaptogenesis. This study investigated the associations between melanopsin genetic variants, sleep, and markers of brain health. METHODS: Linear regression analyses examined the relationship of single-nucleotide polymorphisms (SNPs) within the melanopsin gene (OPN4), with cortical amyloid beta (Aβ), cognition, brain volumes, and self-reported sleep traits in cognitively unimpaired older adults. Further analyses assessed whether sleep traits x OPN4 SNP interactions were associated with markers of brain health. RESULTS: OPN4 SNPs rs2355009 and rs3740334 were associated with attention and processing speed and ventricular volume and language, respectively. Furthermore, rs3740334 and rs1079610 showed significant interactions with sleep traits in association with language. DISCUSSION: This study shows associations of OPN4 genetic variants with markers of brain health, and suggests that these variants interact with sleep to exacerbate cognitive effects. Highlights: The relationships between melanopsin gene (OPN4) variants and markers of brain health were examined cross-sectionally in cognitively unimpaired older individuals. Variation within OPN4is associated with differences in cognition and ventricular volume. rs2355009 and rs3740334 show small–moderate associations with differences in attention and processing speed. Further to this, rs2355009 and rs3740334 were associated with ventricular volumes and language performance, respectively. The interactions between rs3740334 and rs1079610 and sleep traits also showed small–moderate associations with differences in language performance.