SerpinA3N-APOE interaction in astrocytes exacerbates Alzheimer's disease progression through NFκB activation.

Alzheimer's disease (AD) is one of the most prevalent neurodegenerative disorders characterized by β-amyloid (Aβ) deposition, neurofibrillary tangles, neuronal loss, and neuroinflammation. It represents a growing global health crisis. Although astrocytes contribute to neuroinflammatory cascades, their molecular regulators in AD progression remains elusive. Here, through single-cell transcriptomic analysis, we identified SerpinA3N as a disease-progressive modulator upregulated in AD astrocytes, with expression levels correlating with pathological severity. Astrocytic SerpinA3N knockdown in AD mice rescued cognitive deficits across multiple behavioral tests, and concurrently attenuated neuroinflammatory responses, as evidenced by decreased astrocytic/microglial activation and reduced cytotoxic substance release. Moreover, histopathological analyses demonstrated decreased neuronal loss and Aβ deposition following SerpinA3N knockdown. Mechanistically, we elucidated that SerpinA3N cooperated with APOE to exacerbate AD pathology through NFκB signaling activation. Our study uncovers a novel astrocyte-mediated pathogenic cascade driving AD progression and establishes SerpinA3N as a promising therapeutic target for neuroinflammation modulation in AD.