Drug Design, Development and Therapy (Sep 2016)
A triazole derivative elicits autophagic clearance of polyglutamine aggregation in neuronal cells
Abstract
Chang Heng Hsieh,1 Li-Ching Lee,1 Wai-Yin Leong,1 Tsai-Chen Yang,1 Ching-Fa Yao,2 Kang Fang1 1Department of Life Science, 2Department of Chemistry, National Taiwan Normal University, Taipei, Taiwan Abstract: Trinucleotide CAG repeat expansion in the coding region of genes has a propensity to form polyglutamine (polyQ) aggregates that contribute to neuronal disorders. Strategies in elevating autophagy to disintegrate the insoluble aggregates without injuring cells have become a major goal for therapy. In this work, a triazole derivative, OC-13, was found accelerating autophagic clearance of polyQ aggregation in human neuroblastoma cells following induction of the enhanced green fluorescence-conjugated chimeric protein that enclosed 79 polyQ repeats (Q79-EGFP). OC-13 accelerated autophagy development and removed nuclear Q79-EGFP aggregates. The increase of Beclin-1, turnover of LC3-I to LC3-II and degradation of p62 supported autophagy activation. Pretreatment of autophagy inhibitor, bafilomycin A1, not only suppressed autophagolysome fusion, but also impeded aggregate eradication. The study also showed that c-Jun N-terminal kinase/Beclin-1 pathway was activated during OC-13 treatment and c-Jun N-terminal kinase inhibitor impaired autophagy and final breakdown. Autophagic clearance of the insoluble aggregates demonstrated the feasibility of OC-13 in alleviating neuronal disorders because of expanded glutamine stretches. Keywords: autophagic flux, polyglutamine, aggregates clearance, triazole, JNK pathway, neuronal disorders, green fluorescence protein
