Filamin-A and Myosin VI colocalize with fibrillary Tau protein in Alzheimer's disease and FTDP-17 brains

Tauopathies, including Alzheimer's disease (AD), fronto-temporal dementia with parkinsonism linked to chromosome 17 (FTDP-17), Pick's disease and progressive supranuclear palsy, are neurodegenerative disorders neuropathologically characterized by the presence of intraneuronal fibrillary inclusions composed of abnormally phosphorylated-Tau. Tau protein is a neuronal microtubule-associated protein (MAP) involved in microtubules polymerization and stabilization. So far, the molecular mechanisms underlying Tau-mediated cellular toxicity remain elusive. To address the determinants of Tau neurotoxicity, we previously performed a misexpression screening in a Drosophila tauopathy model to identify genetic modifiers of the human Tau-induced neurodegeneration. We identified several components of the actin network as modifiers of Tau V337M-induced neurodegeneration, i.e. Filamin-A, Myosin VI, Paxillin and Transgelin-3. The aim of this study was to assess whether these genetic interactions were associated with a colocalization of the proteins (i) in the brains of patients with Tau pathologies, and (ii) in the brain of transgenic mice overexpressing human mutant Tau. We found that Filamin-A and Myosin VI indeed colocalize with fibrillary Tau protein in AD and FTDP-17 and in Thy-Tau22 transgenic mice.