Background Alzheimer's disease (AD) involves white matter deterioration, but how amyloid-β (Aβ) affects oligodendrocyte lineage cells at different maturation stages remains unclear. Objective To determine whether Aβ impairs oligodendrocyte differentiation and myelination in adult oligodendrocyte precursor cells (OPCs) and to identify molecular correlates via RNA-seq. Methods Oligodendrocyte 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 (oAβ 42 ) to assess differentiation. Myelination was evaluated in organotypic slice cultures. RNA-seq and qPCR were performed to identify oAβ 42 -induced gene expression changes. Results In 5xFAD mice, Olig2 + cells were reduced near plaques, with CC1 + mature oligodendrocytes showing a pronounced decrease, while PDGFRα + OPCs remained unchanged. In vitro, oAβ 42 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 oAβ 42 treatment. RNA-seq showed that oAβ 42 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. Conclusions oAβ 42 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 oAβ 42 response in adult OPCs.
Li et al. (Mon,) studied this question.