Abstract 12215: Death Associated Protein Kinase (DAPK) 3 Mediates Neointimal Hyperplasia via Stimulating Proliferation and Migration of Vascular Smooth Muscle Cells: Implication for Pathogenesis of Hypertensive Vascular Remodeling
Death associated protein kinase (DAPK) is a widely expressed serine/threonine kinase that has been implicated in apoptosis and transcriptional regulation. We have recently found that expression of DAPK3 protein increases in mesenteric artery of spontaneously hypertensive rats (SHR) and determined that DAPK3 mediates the development of hypertension in SHR through promoting reactive oxygen species (ROS)-dependent vascular inflammation. Since pathogenesis of hypertension is in part regulated by vascular structural remodeling via proliferation and migration of vascular smooth muscle cells (SMCs), we tested the hypothesis whether DAPK3 controls SMCs proliferation and migration. In rat mesenteric arterial SMCs, small interfering RNA (siRNA) against DAPK3 inhibited platelet-derived growth factor (PDGF)-BB-induced SMCs proliferation as determined by a cell counting (n=4) or bromodeoxyuridine incorporation assay (n=4). PDGF-BB-induced SMCs migration was significantly inhibited by DAPKs inhibitor (n=10-11, P≤0.01) or DAPK3 siRNA (n=6, P≤0.01) as determined by a Boyden chamber assay. In an wound healing assay, fetal bovine serum (FBS)-induced SMCs migration was significantly inhibited by DAPKs inhibitor (n=5-11, P≤0.01). DAPKs inhibitor or DAPK3 siRNA significantly inhibited PDGF-induced phosphorylation of p38 (n=8, P≤0.05, n=4, P≤0.05, respectively) and heat shock protein (HSP) 27 (n=8, P≤0.05, n=4, respectively) as measured by Western blotting. In an ex vivo mesenteric arterial ring assay, FBS-induced SMCs out-growth was significantly inhibited by DAPKs inhibitor (n=5, P≤0.05). In vivo, DAPKs inhibitor prevented neointimal formation in mice carotid ligation model (n=5-8, P≤0.05). The present results for the first time demonstrate that DAPK3 controls PDGF-BB-induced SMCs proliferation and migration through activation of p38/HSP27 signals, which may lead to the vascular structural remodeling such as neointimal hyperplasia in vivo. Our study suggests DAPK3 as a novel pharmaceutical target for the prevention of hypertensive cardiovascular diseases.
- © 2013 by American Heart Association, Inc.