Cyanine dye conjugates of a 2'-deoxycytidine-based auto- and mitophagy activator extend Caenorhabditis elegans lifespan

BackgroundAutophagy and mitophagy are essential for cellular homeostasis and play key roles in longevity and healthy aging, whereas their age-associated decline contributes to the development of age-related diseases. The identification of small-molecule activators of these pathways therefore represents an important therapeutic objective. MethodsIn this study, we investigated a series of compounds based on a 2'-deoxycitidine-derived scaffold and systematically analyzed the impact of structural substitutions on their ability to induce autophagy and mitophagy. Chemical optimization and functional assays were combined with pathway analysis, cellular readouts of proteostasis, and in vivo lifespan assessment in Caenorhabditis elegans. ResultsThe lead compound enhanced autophagy predominantly via activation of the AMPK-ULK1 signaling pathway and induced mitophagy in a Parkin-independent manner. It promoted autophagosome formation and facilitated functional clearance of aggregation-prone mutant huntingtin. Conjugation of the lead compound with the mitochondria-targeting Cy5 dye further potentiated mitophagy induction, likely through preferential mitochondrial accumulation, while reducing cytotoxicity. Importantly, the conjugated compound significantly extended C. elegans lifespan at lower concentrations compared with the unconjugated analogue. ConclusionsTogether, these results identify a promising chemical scaffold for the development of auto-and mitophagy activators and validate mitochondria-targeted conjugation as an effective strategy to enhance their biological performance. The demonstrated in vivo efficacy supports the potential relevance of these compounds for interventions aimed at preserving proteostasis and mitochondrial quality control, with possible implications for geroprotective applications.