Long non-coding RNA drives stress granule formation in tauopathies.

Tauopathies are a heterogenous group of neurodegenerative disorders characterized by tau aggregation in the brain. In a subset of tauopathies, rare mutations in the gene, which encodes the tau protein, are sufficient to cause disease; however, the events downstream of mutations are poorly understood. Here, we investigate the role of long non-coding RNAs (lncRNAs), transcripts >200 nucleotides with low/no coding potential that regulate transcription and translation, and their role in tauopathy. Using stem cell derived neurons from patients carrying a p.P301L, IVS10+16, or p.R406W mutation, and CRISPR-corrected isogenic controls, we identified transcriptomic changes that occur as a function of the mutant allele. We identified 15 lncRNAs that were commonly differentially expressed across the three mutations. The commonly differentially expressed lncRNAs interact with RNA-binding proteins that regulate stress granule formation. Among these lncRNAs, was significantly reduced in a mouse model of tauopathy and in FTLD-tau, progressive supranuclear palsy, and Alzheimer’s disease brains. We show that interacts with tau and stress granule-associated RNA-binding protein TIA1. Overexpression of mutant tau is sufficient to reduce expression and induce stress granule formation. Rescuing expression leads to reduced stress granule formation and reduced TIA1 levels, suggesting that dysregulation of this non-coding RNA is a causal factor driving stress granule formation via TIA1 in tauopathies.