Sex-dependent effects of neonatal hyperoxia on prefrontal cortex development

Premature infants often require supplemental oxygen therapy, a major risk factor for bronchopulmonary dysplasia and subsequent neurodevelopmental impairment. To determine how neonatal hyperoxia affects prefrontal cortex (PFC) development, we exposed neonatal mice to 85% oxygen (O₂) from postnatal day (P)1-P14 and performed integrated single-nucleus transcriptomic and chromatin accessibility profiling with in vivo and in vitro validation. Hyperoxia induced sex-dependent cellular remodeling, reducing L4/5 intratelencephalic projecting glutamatergic neurons in females and mature oligodendrocytes in males. Across both sexes, hyperoxia suppressed oligodendrocyte maturation, with decreased expression of the myelination genes proteolipid protein 1 (Plp1) and myelin basic protein (Mbp), altered chromatin accessibility, and increased oligodendrocyte transcription factor 2 (OLIG2) protein expression. Regulatory responses were sex specific, with tumor protein p53 (TP53)-regulated metabolic disruption and lysine demethylase 3A (Kdm3a) induction in females, and Netrin-1 signaling in males. Hyperoxia impaired oligodendrocyte progenitor cell (OPC) proliferation and differentiation. These abnormalities were recapitulated in postmortem PFC tissue from infants with BPD and human induced pluripotent stem cell (iPSC)-derived OPCs. These findings show that neonatal hyperoxia disrupts PFC development through sex-dependent effects on neuronal and oligodendrocyte lineages while converging on impaired myelination, highlighting oligodendrocyte dysfunction as a clinically relevant consequence of neonatal oxygen exposure.