Microglia have emerged as key regulators in Alzheimer's disease (AD), yet the molecular factors driving their dysfunction remain unclear. Through integrative transcriptomic and proteomic analyses, we identified PLXDC2, a transmembrane receptor, as a protein consistently upregulated in the AD brain and cerebrospinal fluid. Single-nucleus RNA-seq confirmed its microglia-specific enrichment, particularly in lipid-processing, phagocytic, and inflammatory subclusters. Functional assays revealed that PLXDC2 overexpression in BV2 microglial cells impaired Aβ uptake and suppressed pro-inflammatory cytokines Il-6 and Il-1β, without altering lipid droplet formation. These findings indicate that PLXDC2 plays a regulatory role in critical microglial functions and may drive AD pathogenesis by disrupting phagocytic activity and immune responses.
This work was supported by the New Faculty Startup Fund (370C-20220110), Creative-Pioneering Researchers Program (370C-20230108), and a research grant (370C-20240120) from Seoul National University. M-KS also acknowledges support from the National Research Foundation of Korea (RS2023-00209597, RS-2024-00352229, RS-2024-00440679, RS-2024-00466703), and Seoul R&BD program (BT240041). We acknowledge the use of BioRender.com for the creation of schematic figures.