Epigenetic Regulation in Ischemic Neuroprotection: The Dual Role of HDACs and HATs in Neuroinflammation and Recovery

Ischemic brain and retinal injuries trigger complex molecular cascades involving neuroinflammation, oxidative stress, and neuronal death. Among these mechanisms, epigenetic regulation has emerged as a critical modulator of the injury response. Histone deacetylases (HDACs) and histone acetyltransferases (HATs) dynamically control gene expression by altering chromatin structure. HDACs often promote neuroinflammation and neuronal apoptosis through repression of neuroprotective and anti-inflammatory genes, while HATs generally enhance the transcription of genes involved in cell survival and repair. In ischemia, specific HDAC isoforms (e.g., HDAC1, HDAC2, HDAC3, and HDAC6) have been implicated in microglial activation, glial reactivity, and disruption of immune balance. Conversely, HATs such as CBP/p300 and Tip60 contribute to neuronal resilience and immune regulation. Understanding the dual and context-dependent roles of these epigenetic enzymes offers promising therapeutic avenues. Selective HDAC inhibitors or HAT activators may represent novel strategies to mitigate ischemic damage, support neuroprotection, and facilitate functional recovery.