Abstract 113: Nuclear Translocation of Neuronal Histone Deacetylase 4 (HDAC4) is Detrimental in Stroke

HDAC4 has been identified as a transcriptional corepressor that catalyzes local histone deacetylation. It is highly expressed in neurons and usually trapped in cytosol. In vitro, translocation of HDAC4 from cytosol into nucleus induced neuronal death in response to glutamate toxicity. Here we assessed the hypothesis that accumulation of nuclear HDAC4 occurs after stroke, this translocation is detrimental in stroke outcome and regulated by calcium/calmodulin-dependent protein kinase IV (CaMK IV). Wild type (WT) and CaMK IV knockout (KO) mice were subjected to transient middle cerebral artery occlusion and were sacrificed 6 hours for molecule assessments or 72 hours post stroke for outcome assessments. Primary cortical neurons underwent oxygen-glucose deprivation (OGD) and viability was measured 24 hours after OGD. Lentiviral vectors were utilized in culture and mice. Stroke induced HDAC4 nuclear translocation in WT mice as assessed by both Western blots and immunohistochemistry. Knockdown of HDAC4 improved cell viability after OGD (HDAC4 SiRNA: 87.19±7.57% vs. control: 68.09±3.83%, p In conclusion, we showed that ischemia induces HDAC4 nuclear shuttling in neurons and this translocation is deleterious in stroke outcome. Our data suggested CaMK IV inhibits HDAC4 nuclear accumulation in stroke.