tRNA-derived fragments elevated in Alzheimer's disease facilitate Tau aggregation
Tauopathies, including Alzheimers disease (AD), are driven by pathological Tau aggregation, a process that requires co-factors. Small RNAs (sRNA) have been proposed as such co-factors, yet little is known about endogenous transcripts that promote Tau pathology. We identify stress-induced tRNA-derived RNAs or fragments (tDRs/tRFs) as the most dysregulated sRNA class in human AD brains, PS19 mice overexpressing mutant human Tau, and human neuronal tauopathy models. Notably, the highly accumulating 5GluCTC and 5GlyGCC tRFs directly bind Tau and induce its phosphorylation, oligomerization, fibril formation, and impact neurite growth. 5GluCTC is enriched in pathological Tau precipitates and co-localizes with oligomeric Tau in PS19 mouse brains. Inhibiting 5GluCTC mitigates Tau pathology. Furthermore, these tRFs are highly secreted by neurons and can be taken up by recipient cells, contributing to Tau pathology. Our findings establish 5GluCTC as a key regulator of Tau aggregation and suggest its inhibition as a promising therapeutic strategy for tauopathies. HighlightsO_LISpecific stress-induced 5tRFs strongly accumulate in Alzheimers disease brains C_LIO_LI5GluCTC binds and co-localizes with pathologic Tau in neurons and in the brain C_LIO_LI5GluCTC promotes pathologic Tau species while its inhibition reverses these effects C_LIO_LISpecific 5tRFs are horizontally transferred between neurons C_LI