To identify Huntington's Disease therapeutics, we conducted high-content small molecule and RNAi suppressor screens using a Drosophila primary neural culture Huntingtin model. Drosophila primary neurons offer a sensitive readout for neurotoxicty, as their neurites develop dysmorphic features in the presence of mutant polyglutamine-expanded Huntingtin compared to nonpathogenic Huntingtin. By tracking the subcellular distribution of mRFP-tagged pathogenic Huntingtin and assaying neurite branch morphology via live-imaging, we identified suppressors that could reduce Huntingtin aggregation and/or prevent the formation of dystrophic neurites. The custom algorithms we used to quantify neurite morphologies in complex cultures provide a useful tool for future high-content screening approaches focused on neurodegenerative disease models. Compounds previously found to be effective aggregation inhibitors in mammalian systems were also effective in Drosophila primary cultures, suggesting translational capacity between these models. However, we did not observe a direct correlation between the ability of a compound or gene knockdown to suppress aggregate formation and its ability to rescue dysmorphic neurites. Only a subset of aggregation inhibitors could revert dysmorphic cellular profiles. We identified lkb1, an upstream kinase in the mTOR/Insulin pathway, and four novel drugs, Camptothecin, OH-Camptothecin, 18β-Glycyrrhetinic acid, and Carbenoxolone, that were strong suppressors of mutant Huntingtin-induced neurotoxicity. Huntingtin neurotoxicity suppressors identified through our screen also restored viability in an in vivo Drosophila Huntington's Disease model, making them attractive candidates for further therapeutic evaluation.
Disease-related studies
High-content chemical and RNAi screens for suppressors of neurotoxicity in a Huntington's disease model.” PLoS One, 6, 8, Pp. e23841.Abstract
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Drosophila RNAi screen reveals CD36 family member required for mycobacterial infection.” Science, 309, 5738, Pp. 1251-3.Abstract
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Genomic screening with RNAi: results and challenges.” Annu Rev Biochem, 79, Pp. 37-64.Abstract
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COPI activity coupled with fatty acid biosynthesis is required for viral replication.” PLoS Pathog, 2, 10, Pp. e102.Abstract
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A systems-level interrogation identifies regulators of Drosophila blood cell number and survival.” PLoS Genet, 11, 3, Pp. e1005056.Abstract
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Genetic determinants of phosphate response in Drosophila.” PLoS One, 8, 3, Pp. e56753.Abstract
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Drosophila genome-wide RNAi screen identifies multiple regulators of HIF-dependent transcription in hypoxia.” PLoS Genet, 6, 6, Pp. e1000994.Abstract
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A screen for morphological complexity identifies regulators of switch-like transitions between discrete cell shapes.” Nat Cell Biol, 15, 7, Pp. 860-71.Abstract
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Mechanisms to suppress multipolar divisions in cancer cells with extra centrosomes.” Genes Dev, 22, 16, Pp. 2189-203.Abstract
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An integrative approach to ortholog prediction for disease-focused and other functional studies.” BMC Bioinformatics, 12, Pp. 357.Abstract
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