Gastrodin inhibits the formation of ataxin-3 aggregates by regulating the level of ERK1/2/P38 proteins

Background: Spinocerebellar ataxia type 3 (SCA3/Machado-Joseph disease), an incurable autosomal dominant neurodegenerative disorder, is caused by cytotoxic aggregation of polyglutamine-expanded ataxin-3 protein. Novel therapeutic strategies targeting its pathogenesis are urgently needed. Purpose: Given gastrodin's established antioxidative and neuroprotective properties, this study investigated its therapeutic potential against SCA3 pathogenesis. Methods: Three distinct cell models including parental HEK293T, ataxin-3-15Q (physiologic), and ataxin-3-77Q (pathogenic) were employed to assess gastrodin cytotoxicity, quantify insoluble aggregate formation and measure soluble ataxin-3 levels. Mechanistic studies included antioxidant capacity assays, human phosphokinase array profiling (37 kinases) and western blot validation of MAPK pathway components. Results: Gastrodin treatment showed no cytotoxicity, significantly suppressed ataxin-3-77Q aggregate accumulation (p<0.01), increased soluble ataxin-3 levels, enhanced cellular antioxidant capacity and selectively downregulated ERK1/2 and p38 proteins in MAPK pathways. Conclusion: We provide first evidence that gastrodin mitigates polyQ-mediated proteotoxicity by reducing ataxin-3 aggregation through suppression of the ERK1/2-p38 signaling axis, revealing a novel mechanistic basis for SCA3 therapeutic development.