AS1842856 Reduces β-Amyloid Burden via Inhibiting PLA2G4A-Mediated Lysosomal Dysfunction in APP/PS1 Mice

Aims: Both cytosolic Phospholipase A2 (PLA2G4A)-induced lysosomal membrane disruption and glycogen synthase kinase-3α/β (GSK3α/β)-mediated lysosomal dysfunction have been implicated in neurodegeneration, with a potential regulatory relationship between these two pathways. We recently identified AS1842856 (AS) as a suppressor of GSK3α/β. This study was therefore designed to investigate whether AS mitigates Alzheimer's disease (AD) progression by targeting PLA2G4A to restore lysosomal homeostasis.

Methods: The therapeutic potential of AS was investigated in APP/PS1 mice by analyzing cognitive function, β-amyloid (Aβ) load, and lysosomal integrity, with its mechanism of action further explored in N2a-sw cells.

Results: AS treatment reduced GSK3α/β expression in both APP/PS1 mice and N2a-sw cells. This suppression led to decreased PLA2G4A levels, restoration of lysosomal membrane integrity, and enhanced lysosomal degradation of Aβ. Consequently, AS administration alleviated Aβ burden and improved cognitive function in APP/PS1 mice. Moreover, AS was found to inhibit NF-κB-mediated PLA2G4A expression. Knockdown experiments further revealed that reduced GSK3β-but not GSK3α-reproduced the suppressive effect on PLA2G4A.

Conclusion: Our study identified the GSK3β/NF-κB/PLA2G4A signaling axis as a novel therapeutic target in AD, and AS could inhibit this axis to mitigate Aβ pathology by promoting lysosomal degradation of Aβ.