Lineage-specific Nrf2 signaling orchestrates distinct neuroprotective mechanisms in acute ischemic stroke.

Nuclear factor erythroid 2-related factor 2 (Nrf2), a key antioxidant transcription factor, shows neuroprotective potential in ischemic stroke (IS); however, its cell type-specific functions across different neural lineages remain partially understood. This study innovatively employs a comparative knockout paradigm, utilizing neural lineage knockout (Nrf2flox/flox; Nestin-Cre, targeting neural progenitor cells and their derived lineages) and astrocyte-biased knockout (Nrf2flox/flox; GFAP-Cre) mouse models, combined with an in vitro co-culture system, to elucidate the lineage-dependent and differential protective mechanisms of Nrf2 in acute IS (AIS). Results demonstrated that both knockout models exacerbated neurological deficits, increased cerebral infarct volumes, and reduced cerebral blood flow. However, a marked phenotypic divergence was observed. The Nestin-Cre model exhibited more severe neurological deterioration, associated with dysregulated iron metabolism, enhanced lipid peroxidation, and aggravated neuroinflammation, suggesting a predominant role for neuronal Nrf2 in counteracting ferroptosis and neuroinflammatory responses. In contrast, the GFAP-Cre model did not induce ferroptosis but promoted neurotoxic A1-type astrocyte polarization and enhanced inflammatory injury via NF-κB pathway activation. This finding underscores the unique function of astrocytic Nrf2 in modulating the neuroinflammatory microenvironment. These cell-type-specific effects were further validated in an in vitro oxygen-glucose deprivation/reoxygenation (OGD/R) model. Through this cross-lineage comparative analysis, our study systematically elucidates, for the first time, the distinct protective mechanisms of Nrf2 in neurons and astrocytes, thereby advancing understanding of its functional heterogeneity and providing a novel theoretical basis for developing cell-type-biased, Nrf2-targeted therapeutic strategies.