Abstract 18462: Heparin Cofactor II Promotes Angiogenesis in Response to Ischemic Hindlimb via an AMPK-eNOS-dependent Manner

Abstract

Background: Heparin cofactor II (HCII) generally exerts to suppress activated thrombin by binding to dermatan sulfate at injured vascular walls. We have revealed that protective actions of HCII against cardiovascular disease in both experimental and clinical studies. In the present study, we investigated to clarify HCII effect on angiogenesis. Methods and Results: Male heterozygous HCII deficient (HCII+/−) mice and male littermate wild-type (HCII+/+) mice at the age of 12-16 weeks were subjected to unilateral ischemic hindlimb surgery. The analysis of laser speckle blood flow showed that blood flow recovery in response to ischemia was insufficient in HCII+/− mice compared to HCII+/+ mice. Number of capillaries and arterioles, eNOS and AMPK phosphorylation in ischemic adductor muscles were reduced in HCII+/− mice. Blood flow recovery and capillary density, as well as phosphorylation levels of eNOS and AMPK in ischemic muscles of HCII+/− mice were almost restored by administration of human purified HCII (h-HCII) protein. In in vitro studies, h-HCII treatment augmented tube formation, cell proliferation and migration of human aortic endothelial cells (HAECs). h-HCII increased the phosphorylation levels of endothelial nitric oxide synthesis (eNOS) and AMP-activated protein kinase (AMPK) in HAECs. On the other hand, h-HCII-induced tube formation, cellular migration and proliferation and eNOS phosphorylation in HAECs were abolished by compound C, an AMPK inhibitor. Thrombin-induced reduction of eNOS phosphorylation and expression was also prevented by h-HCII asministration. Conclusion: HCII enhances cellular activity of endothelial cells and promotes angiogenesis in response to ischemic hindlimb via an AMPK-eNOS signaling pathway. HCII potentiates to be a new therapeutic target for treatment in patients with peripheral artery disease.