Yang, DejunAbdallah, AbbasLi, ZhaodongLu, YubingAlmeida, SandraGao, Fen-Biao2022-08-232022-08-232015-10-012015-10-29Acta Neuropathol. 2015 Oct;130(4):525-35. doi: 10.1007/s00401-015-1448-6. Epub 2015 Jun 2. <a href="http://dx.doi.org/10.1007/s00401-015-1448-6">Link to article on publisher's site</a>0001-6322 (Linking)10.1007/s00401-015-1448-626031661https://hdl.handle.net/20.500.14038/39799C9ORF72 repeat expansion is the most common genetic mutation in frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS). Abnormal dipeptide repeat proteins (DPRs) generated from repeat-associated non-AUG (RAN) translation of repeat-containing RNAs are thought to be pathogenic; however, the mechanisms are unknown. Here we report that (GR)80 and (PR)80 are toxic in neuronal and non-neuronal cells in Drosophila. In contrast to reported shorter poly(GR) forms, (GR)80 is mostly localized throughout the cytosol without detectable accumulation in the nucleolus, accompanied by suppression of Notch signaling and cell loss in the wing. Some Notch target genes are also downregulated in brains and iPSC-derived cortical neurons of C9ORF72 patients. Increased Notch expression largely suppressed (GR)80-induced cell loss in the wing. When co-expressed in Drosophila, HeLa cells, or human neurons, (GA)80 recruited (GR)80 into cytoplasmic inclusions, partially decreasing the toxicity of (GR)80 and restoring Notch signaling in Drosophila. Thus, different DPRs have opposing roles in cell loss and we identify the Notch pathway as one of the receptor signaling pathways that might be compromised in C9ORF72 FTD/ALS.en-USCopyright © The Author(s) 2015. Open Access. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.http://creativecommons.org/licenses/by/4.0/ALSDPRDrosophilaFTDInclusionMotor neuronNotchPoly(GA)Poly(GR); Poly(PR)RAN translationGenetics and GenomicsMolecular and Cellular NeuroscienceNervous System DiseasesNeurologyNeuroscience and NeurobiologyJournal Articlehttps://escholarship.umassmed.edu/cgi/viewcontent.cgi?article=3600&amp;context=oapubs&amp;unstamped=1https://escholarship.umassmed.edu/oapubs/25967779453oapubs/2596