Amyloid-β suppresses oligodendrocyte differentiation in adult oligodendrocyte precursor cells (OPCs), with inflammatory gene changes distinguishing it from developmental OPCs

BackgroundAlzheimer's disease (AD) involves white matter deterioration, but how amyloid-β (Aβ) affects oligodendrocyte lineage cells at different maturation stages remains unclear.ObjectiveTo determine whether Aβ impairs oligodendrocyte differentiation and myelination in adult oligodendrocyte precursor cells (OPCs) and to identify molecular correlates via RNA-seq.MethodsOligodendrocyte lineage cells were examined in plaque-associated regions of 8-month-old 5x familial Alzheimer's disease (FAD) mice by immunohistochemistry. Primary OPCs from neonatal and adult rats were cultured with or without amyloid-β_1-42 oligomers (oAβ₄₂) to assess differentiation. Myelination was evaluated in organotypic slice cultures. RNA-seq and qPCR were performed to identify oAβ₄₂-induced gene expression changes.ResultsIn 5xFAD mice, Olig2⁺ cells were reduced near plaques, with CC1⁺ mature oligodendrocytes showing a pronounced decrease, while PDGFRα⁺ OPCs remained unchanged. In vitro, oAβ₄₂ inhibited differentiation of both neonatal and adult OPCs, with adult OPCs exhibiting intrinsically slower maturation. Slice cultures revealed selective hypomyelination (reduced myelin basic protein) after oAβ₄₂ treatment. RNA-seq showed that oAβ₄₂ induced a distinct transcriptomic profile in adult OPCs, with upregulated genes enriched in immune/inflammatory pathways. Core inflammatory genes Nr4a1 and Tnf were significantly upregulated, validated by qPCR.ConclusionsoAβ₄₂ plaque pathology is associated with oligodendrocyte maturation blockade. Aβ impairs OPC differentiation in purified cultures accompanied by inflammatory transcriptional changes. These findings highlight oligodendrocyte dysfunction in AD white matter pathology and reveal a specific oAβ₄₂ response in adult OPCs.