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Özcan, G. G.

Publications and source records attributed to Özcan, G. G..

2 recordsLinked to original sources

Behavioural pharmacology predicts disrupted signalling pathways and candidate therapeutics from zebrafish mutants of Alzheimer's disease risk genes

By exposing genes associated with disease, genomic studies provide hundreds of starting points that should lead to druggable processes. However, our ability to systematically translate these genomic findings into biological pathways remains limited. Here, we combine rapid loss-of-function mutagenesis of Alzheimers risk genes and behavioural pharmacology in zebrafish to predict disrupted processes and candidate therapeutics. FramebyFrame, our expanded package for the analysis of larval behaviours, revealed that decreased night-time sleep was common to F0 knockouts of all four late-onset Alzheimers risk genes tested. We developed an online tool, ZOLTAR, which compares any behavioural fingerprint to a library of fingerprints from larvae treated with 3,677 compounds. ZOLTAR successfully predicted that sorl1 mutants have disrupted serotonin signalling and identified betamethasone as a drug which normalises the excessive day-time sleep of presenilin-2 knockout larvae with minimal side effects. Predictive behavioural pharmacology offers a general framework to rapidly link disease-associated genes to druggable pathways.

neuroscience↗

Genetic and chemical disruption of Amyloid Precursor Protein processing impairs zebrafish sleep maintenance

Amyloid precursor protein (APP) is a brain-rich, single pass transmembrane protein that is proteolytically processed into multiple products, including Amyloid-beta (A{beta}), a major driver of Alzheimers disease (AD). Although both over-expression of APP, as in mouse models used to study AD, and exogenously delivered A{beta} lead to changes in sleep behaviors, whether APP processing plays an endogenous role in regulating sleep is unknown. Here, we demonstrate that APP processing into A{beta}40 and A{beta}42 is conserved in zebrafish and then describe sleep/wake phenotypes in loss of function appa and appb mutants. Larvae with mutations in appa had reduced waking activity but normal sleep patterns, while larvae that lacked appb had shortened sleep bout durations at night. Treatment with the {gamma}-secretase inhibitor DAPT also shortened sleep bouts at night, while the BACE-1 inhibitor lanabecestat lengthened sleep bouts. Since both drugs fail to further alter sleep in appb mutants, and intraventricular injection of the App cleavage product P3 also shortens night-time sleep bouts, we conclude that the proper balance of Appb proteolytic processing is required for normal sleep maintenance in zebrafish.

neuroscience↗