A novel transgenic mouse line with hippocampus-dominant and inducible expression of truncated human tau.

Background: Intraneuronal accumulation of hyperphosphorylated tau is a defining hallmark of Alzheimer's disease (AD). However, mouse models imitating AD-exclusive neuronal tau pathologies are lacking.

Methods: We generated a new tet-on transgenic mouse model expressing truncated human tau N1-368 (termed hTau368), a tau fragment increased in the brains of AD patients and aged mouse brains. Doxycycline (dox) was administered in drinking water to induce hTau368 expression. Immunostaining and Western blotting were performed to measure the tau level. RNA sequencing was performed to evaluate gene expression, and several behavioral tests were conducted to evaluate mouse cognitive functions, emotion and locomotion.

Results: Dox treatment for 1-2 months at a young age induced overt and reversible human tau accumulation in the brains of hTau368 transgenic mice, predominantly in the hippocampus. Meanwhile, the transgenic mice exhibited AD-like high level of tau phosphorylation, glial activation, loss of mature neurons, impaired hippocampal neurogenesis, synaptic degeneration and cognitive deficits.

Conclusions: This study developed a well-characterized and easy-to-use tool for the investigations and drug development for AD and other tauopathies.