Histone H3 lysine 18 lactylation attenuates neuroinflammation and neurological damage by regulating microglial plxnb2 after ischemic stroke

Microglia are major resident immune cells in the central nervous system and are actively involved in the pathogenesis of ischemic stroke. Histone lactylation confers macrophage homeostatic gene expressions and regulates physiological and immune-related pathological conditions. However, the spatiotemporal expression and functional role of histone lactylation in microglial reprogramming and neurological injuries after ischemic stroke remain elusive. In this study, we observed increased levels of histone lactylation in peri-infarct areas after the middle cerebral artery occlusion-induced focal cerebral ischemia in mice. The enhanced histone lactylation favored an anti-inflammatory micro-environment and provided neuroprotective effects after ischemia, which might be mediated by histone H3 lysine 18 lactylation (H3K18la)-regulated plxnb2 expression in microglia. Microglia-specific inhibition of plxnb2 abrogated the neuroprotective effects of lactate after ischemic stroke. These findings suggest that interventions aimed at the lactate/lactylation(H3K18la)/plxnb2 axis may represent a promising therapeutic strategy for ischemic stroke treatment.