Amisulpride as a potential disease‐modifying drug in the treatment of tauopathies

Abstract INTRODUCTION Hyperphosphorylation and aggregation of the microtubule‐associated protein tau cause the development of tauopathies, such as Alzheimer's disease and frontotemporal dementia (FTD). We recently uncovered a causal link between constitutive serotonin receptor 7 (5‐HT7R) activity and pathological tau aggregation. Here, we evaluated 5‐HT7R inverse agonists as novel drugs in the treatment of tauopathies. METHODS Based on structural homology, we screened multiple approved drugs for their inverse agonism toward 5‐HT7R. Therapeutic potential was validated using biochemical, pharmacological, microscopic, and behavioral approaches in different cellular models including tau aggregation cell line HEK293 tau bimolecular fluorescence complementation, primary mouse neurons, and human induced pluripotent stem cell–derived neurons carrying an FTD‐associated tau mutation as well as in two mouse models of tauopathy. RESULTS Antipsychotic drug amisulpride is a potent 5‐HT7R inverse agonist. Amisulpride ameliorated tau hyperphosphorylation and aggregation in vitro. It further reduced tau pathology and abrogated memory impairment in mice. DISCUSSION Amisulpride may be a disease‐modifying drug for tauopathies.