id_706. LIGHT POLLUTION AS A DRIVER OF RETINAL AGEING AND NEURODEGENERATION IN DROSOPHILA MELANOGASTER.
Kinga Skoczek1,2, Milena Damulewicz2
1 Jagiellonian University, Doctoral School of Exact and Natural Sciences, Prof. St. Łojasiewicza St 11, Kraków, Poland
2 Jagiellonian Univeristy, Department of Cell Biology and Imaging, Institute of Zoology and Biomedical Research, Gronostajowa St 9, Kraków, Poland
INTRODUCTION: Retinal ageing is followed by visual decline and disturbed circadian regulation. Artificial light at night (ALAN) and blue light disrupt circadian rhythms and may promote neurodegeneration, however, their impact on retinal neurodegeneration and ageing still remains poorly characterized. Bruchpilot (BRP), a presynaptic protein forming active zones in photoreceptor terminals, enables efficient neurotransmission in the first visual neuropil of Drosophila. The α subunit of the Na⁺/K⁺-ATPase (αATP), present in epithelial glial cells, maintains ionic homeostasis, supporting synaptic transmission and circadian regulation. Both BRP and αATP are regulated by light and the circadian clock, showing a distinct pattern with peaks at the beginning of day and night, serving as markers of visual system clock alterations.
AIM(S): This study investigates the combined effect of aging and light pollution conditions on circadian rhythmicity in the visual system.
METHOD(S): Male CantonS flies were kept under standard light (LD12:12), dim light at night (L-DIM), or 1h of blue light before night (LBD), aged to 7, 30 or 60 days. Flies were decapitated at four time points; heads were fixed,cryosectioned and immunostained for BRP or αATP. Immunofluorescence in the lamina was quantified by confocal microscopy. In addition, retinas were dissected at 6 time points, brp and αATP mRNA levels in young and old flies were measured by qPCR.
RESULTS: Under LD12:12, young flies displayed rhythmic BRP and αATP expression in the lamina, which weakened with age. L-DIM and LBD caused additional shifts in the protein expression. qPCR showed that rhythms in retina differ from those in lamina and vary with age and exposure to light pollution.
CONCLUSIONS: Our results show that ageing weakens circadian regulation in the Drosophila visual system, indicated by molecular changes both in the photoreceptors and glial cells, with artificial light accelerating that process. These changes suggest that disrupted circadian control may contribute to retinal ageing.
FINANCIAL SUPPORT: 2022/47/B/NZ3/00250