Abstract 229: Hydrogen sulfide donor, the Organic Polysulfide Diallyl Trisulfide Augments Ischemia-induced Angiogenesis by Upregulation of VEGF-Akt-eNOS Pathway

Abstract

Introduction: Hydrogen sulfide (H2S) upregulates anti-oxidant, anti-apoptosis, anti-inflammatory, and cell survival. H2S plays an extremely important role in the homeostasis of the cardiovascular system and in the pathogenesis of cardiovascular disease. The diallyl trisulfide (DATS) is a polysulfide constituent found in garlic oil, and known as H2S donor that is able to release H2S continuously. Peripheral artery disease (PAD) causes considerable morbidity and mortality. The aim of this study was investigate whether the DATS would augment ischemia-induced angiogenesis. Methods: The unilateral permanent femoral artery ligation was performed in C57BL/6J mice (8-10 weeks old, n=8-10/group) and eNOS KO mice (8-10 weeks old, n=5-8/group), and vehicle or DATS (500 μg/kg/day) was injected intra-peritonealy up to 1 week following the hind limb ischemia (HLI). We evaluated the blood flow recovery using the laser Doppler perfusion image and capillary density stained with CD31 at 3 weeks following HLI. We assessed VEGF level by qPCR analysis and activations of eNOS and Akt by western blot analysis in ischemic tissues. Moreover, we cultured HUVECs in a hypoxic chamber with serum starvation for 24 hour, and then evaluated apoptosis by tunnel staining and oxidative stress by DHE staining with or without DATS (50 μmol). We also evaluated activations of eNOS and Akt in cultured HUVECs with or without DATS. Results: DATS treatment significantly increased blood flow (0.45 vs 0.78,p<0.05) and capillary density (1.57 vs 1.85,p<0.05) at 3 weeks following HLI compared to vehicle. DATS also increased mRNA level of VEGF and activation of Akt and eNOS at 3 days following HLI. On the other hand, DATS treatment failed to increase blood flow and capillary density at 3 weeks following HLI in eNOS KO mice. The DATS treatment inhibited apoptosis and oxidative stress in cultured HUVECs via activation of Akt and eNOS pathway in vitro. Conclusions: Our results indicate that DATS treatment could augment ischemia-induced angiogenesis by upregulation of VEGF-Akt-eNOS pathway that leads to inhibitions of apoptosis and oxidative stress. These results suggest that administration of H2S releasing agents might be efficacious for the treatment of PAD.