@article{APS11509,
author = {Ye Peng and Sha-sha Wang and Ke-dao Lai and Jun-rui Ye and Wen-bing He and Xu Yan and Zhao Zhang and Shi-feng Chu and Nai-hong Chen},
title = {Protopanaxatriol restores cognitive function in okadaic acid-treated mice via direct inhibition of pathological CDK5 activity},
journal = {Acta Pharmacologica Sinica},
volume = {14},
number = {5},
year = {2026},
keywords = {},
abstract = {Alzheimer’s disease (AD), a prevalent neurodegenerative dementia, presents therapeutic challenges due to safety concerns about amyloid-targeting strategies. Traditional Chinese medicine (TCM) may offer alternative avenues for exploration. Ginsenoside Rg1, a key bioactive component of ginseng, has shown neuroprotective potential in okadaic acid (OKA)-induced rat model, its limited brain bioavailability suggests that its metabolite protopanaxatriol (Ppt) may exert these effects. In this study, we investigated the therapeutic effects of Ppt on OKA-induced mice model and the underlying mechanisms. Cultured hippocampal neurons were treated with OKA (0.5 nM) with or without Ppt co-treatment for 24 h. We showed that Ppt (1.25–40 nM) exerted dose-dependent neuroprotection against OKA-induced cytotoxicity, with the maximal protection observed at 10 nM. The suppressed tau aggregation by Ppt was confirmed using a Venus-tau bimolecular fluorescence complementation (BiFC) system. Molecular dynamics simulations and microscale thermophoresis (MST) revealed that Ppt bound to the catalytic domain of CDK5 at Cys83, destabilizing the CDK5/p25 complex. Co-immunoprecipitation (Co-IP) assays with CDK5 mutants (S159T, C83A, F80A and D86A) validated this interaction. In vivo mice were treated with Ppt (10 mg/kg, i.g.) for 25 days. On D8 and D9, the mice were bilaterally microinjected with OKA into the cerebral ventricles. We showed that Ppt administration improved spatial memory deficits in Novel Object Recognition and Barnes Maze tests; these effects were abolished in mice expressing a lentivirus-mediated CDK5[C83A] mutant. Hippocampal transcriptomic profiling in OKA-challenged mice following Ppt intervention revealed that Ppt modulated Drp1-mediated mitochondrial fission/fusion dynamics, mitigating OKA-induced mitochondrial homeostasis disruption. Collectively, these results demonstrate that Ppt attenuates tau pathology by selectively targeting CDK5 at Cys83, thereby reducing pathological kinase activity, rebalancing mitochondrial function, and improving cognitive outcomes in an OKA-induced mice neurodegeneration model. The study underscores the therapeutic potential of Ppt in AD treatment and supports CDK5 modulation as a strategic approach for addressing tau-related neurodegeneration.},
issn = {1745-7254}, url = {http://www.chinaphar.com/article/view/11509}
}