BMAL1-GPX3 axis in the choroid plexus mitigates Aβ pathology in an amyloid mouse model.

Alzheimer’s disease (AD) is the most common neurodegenerative disorder, with circadian rhythm disturbances strongly linked to its pathogenesis. The choroid plexus (ChP) is a circadian-regulated structure in the brain ventricles, but the role of the core clock gene brain and muscle ARNT-like protein 1 (BMAL1) in ChP in relation to AD pathology remains unclear. Here, we report that knockdown of Bmal1 in ChP epithelial cells of 5xFAD mice alleviates amyloid-β (Aβ) pathology, primarily by improving the function of astrocytes and border-associated macrophages (BAMs), with the latter potentially mediated by the upregulation of the secreted protein glutathione peroxidase 3 (GPX3), which reduces lipid peroxidation in BAMs. Collectively, our findings establish the ChP-driven BMAL1-GPX3 axis as a new Aβ clearance mechanism, with GPX3 representing a promising therapeutic target. These findings provide new mechanistic insights into AD and suggest innovative treatment approaches.