The CDK4/6 inhibitor abemaciclib attenuates cognitive impairment and neuroinflammation via DYRK1A in human tau transgenic mice.

We recently demonstrated that abemaciclib treatment modulates cognitive function, Alzheimer's disease (AD) pathology, and neuroinflammatory responses in wild-type mice treated with lipopolysaccharide and in 5xFAD mice. In this study, we investigated the influence of abemaciclib treatment on neuroinflammation and cognitive function in 6- or 9-month-old PS19 mice, a P301S mutant tauopathy model. We found that abemaciclib administration suppressed microglial activation in 6-month-old PS19 mice, whereas astrocytic activation was partially attenuated in the entorhinal cortex but not in the hippocampus. In addition, abemaciclib treatment improved short-term and recognition memory and the dendritic spine formation in 6- and 9-month-old PS19 mice. More importantly, abemaciclib administration enhanced short-term and recognition memory in a DYRK1A-dependent manner in 6-month-old PS19 mice. Collectively, our results suggest that abemaciclib treatment alleviates neuroinflammatory responses and cognitive impairment through DYRK1A in 6- or 9-month-old human tau transgenic PS19 mice, highlighting how this multi-kinase-targeting drug could be leveraged for the treatment of neurodegenerative diseases.