AUTEN-67 (Autophagy Enhancer-67) Hampers the Progression of Neurodegenerative Symptoms in a Drosophila model of Huntington’s Disease

Article type: Research Article

Authors: Billes, Viktor^a | Kovács, Tibor^{a; b} | Hotzi, Bernadette^{a; b} | Manzéger, Anna^b | Tagscherer, Kinga^b | Komlós, Marcell^a | Tarnóci, Anna^a | Pádár, Zsolt^a | Erdős, Attila^a | Bjelik, Annamaria^c | Legradi, Adam^c | Gulya, Károly^c | Gulyás, Balázs^{d; e; f} | Vellai, Tibor^{a; b; *}

Affiliations: [a] Velgene Biotechnology Research Ltd., Szeged, Hungary | [b] Department of Genetics, Eötvös Loránd University, Budapest, Hungary | [c] Department of Cell Biology and Molecular Medicine, University of Szeged, Szeged, Hungary | [d] Karolinska Institute, Department of Clinical Neuroscience, Stockholm, Sweden | [e] Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore | [f] Imperial College London, Department of Medicine, Division of Brain Sciences, London, UK

Correspondence: [*] Correspondence to: T. Vellai, Department of Genetics, Eötvös Loránd University, Pázmány Péter stny. 1/C, Budapest, H-1117, Hungary. Tel.: +36 1 372 2500, Ext: 8684; Fax: +36 1 372 2641; E-mail: [email protected].

Abstract: Background: Autophagy, a lysosome-mediated self-degradation process of eukaryotic cells, serves as a main route for the elimination of cellular damage [1–3]. Such damages include aggregated, oxidized or misfolded proteins whose accumulation can cause various neurodegenerative pathologies, including Huntington’s disease (HD). Objective: Here we examined whether enhanced autophagic activity can alleviate neurophatological features in a Drosophila model of HD (the transgenic animals express a human mutant Huntingtin protein with a long polyglutamine repeat, 128Q). Methods: We have recently identified an autophagy-enhancing small molecule, AUTEN-67 (autophagy enhancer 67), with potent neuroprotective effects [4]. AUTEN-67 was applied to induce autophagic activity in the HD model used in this study. Results: We showed that AUTEN-67 treatment interferes with the progressive accumulation of ubiquitinated proteins in the brain of Drosophila transgenic for the pathological 128Q form of human Huntingtin protein. The compound significantly improved the climbing ability and moderately extended the mean life span of these flies. Furthermore, brain tissue samples from human patients diagnosed for HD displayed increased levels of the autophagy substrate SQSTM1/p62 protein, as compared with controls. Conclusions: These results imply that AUTEN-67 impedes the progression of neurodegenerative symptoms characterizing HD, and that autophagy is a promising therapeutic target for treating this pathology. In humans, AUTEN-67 may have the potential to delay the onset and decrease the severity of HD.

Keywords: Huntington’s disease, Huntingtin, polyQ, neurodegeneration, autophagy, AUTEN-67, Drosophila, climbing assay, ubiquitinated proteins, Ref(2)P/SQSTM1/p62

DOI: 10.3233/JHD-150180

Journal: Journal of Huntington's Disease, vol. 5, no. 2, pp. 133-147, 2016