HDAC3 Downregulation Improves Cerebral Ischemic Injury via Regulation of the SDC1-Dependent JAK1/STAT3 Signaling Pathway Through miR-19a Upregulation.

Histone deacetylase (HDAC) inhibitors can protect the brain from ischemic injury. This study aimed to identify the regulation of HDAC3 in cerebral ischemic injury. Middle cerebral artery occlusion (MCAO) was performed to establish a mouse model with cerebral ischemic injury, in which expression of HDAC3 and miR-19a was evaluated using RT-qPCR. In MCAO mice with silencing of HDAC3, infarct volume was determined using 2,3,5-triphenyl tetrazolium chloride (TTC) staining, and serum levels of TNF-α, IL-6, and IL-8 were measured using ELISA. An in vitro model was constructed in human umbilical vein endothelial cells (HUVECs) with oxygen-glucose deprivation/reoxygenation (OGD/R), followed by gain- and loss-of-function experiments. Relationships among miR-19a, HDAC3, and syndecan-1 (SDC1) were explored using RIP, ChIP, and dual-luciferase reporter assays. The expression of HDAC3, SDC1, JAK1, and STAT3 along with the extent of JAK1 and STAT3 phosphorylation was measured by Western blot analysis. HUVEC viability, apoptosis, and angiogenesis were assessed by CCK-8, flow cytometry, and angiogenesis assays in vitro separately. We found elevated HDAC3 and downregulated miR-19a expression in the MCAO mice. Decreased TNF-α, IL-6, and IL-8 serum levels were observed in response to silencing of HDAC3. HDAC3 inhibited the expression of miR-19a, which in turn targeted SDC1, leading to JAK1/STAT3 signaling pathway activation. HDAC3 overexpression or miR-19a inhibition repressed HUVEC viability and angiogenesis but enhanced HUVEC apoptosis. Our data unraveled the mechanism whereby HDAC3 inhibition ameliorated cerebral ischemic injury by activating the JAK1/STAT3 signaling pathway through miR-19a-mediated SDC1 inhibition.