title: High-content chemical and RNAi screens for suppressors of neurotoxicity in a Huntington's disease model.
abstract: 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.
authors: Department of Biology, Department of Brain and Cognitive Sciences, The Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America. jschulte@mit.edu
authors: Joost
authors: J
authors: Schulte
authors: Katharine J
authors: KJ
authors: Sepp
authors: Chaohong
authors: C
authors: Wu
authors: Pengyu
authors: P
authors: Hong
authors: J Troy
authors: JT
authors: Littleton
mesh_terms: D000465:Algorithms; D000818:Animals; D002478:Cells, Cultured; D004195:Disease Models, Animal; D004331:Drosophila melanogaster / Q000187:drug effects* / Q000235:genetics*; D016153:Genes, Suppressor; D057166:High-Throughput Screening Assays / Q000379:methods*; D006801:Humans; D000071058:Huntingtin Protein; D006816:Huntington Disease / Q000235:genetics*; D050505:Mutant Proteins / Q000737:chemistry / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000737:chemistry / Q000378:metabolism; D016501:Neurites / Q000187:drug effects / Q000378:metabolism; D009474:Neurons / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D009498:Neurotoxins / Q000633:toxicity*; D009687:Nuclear Proteins / Q000737:chemistry / Q000378:metabolism; D020836:Protein Structure, Quaternary; D034622:RNA Interference; D015203:Reproducibility of Results
chemical_list: C086055:HTT protein, human; D000071058:Huntingtin Protein; D050505:Mutant Proteins; D009419:Nerve Tissue Proteins; D009498:Neurotoxins; D009687:Nuclear Proteins