The hydrogen sulfide donor, GYY 4137, exhibits anti‐atherosclerotic activity in high fat fed apolipoprotein E−/− mice

Abstract

Background and Purpose: Atherosclerosis is associated with reduced vascular hydrogen sulfide (H 2 S) biosynthesis. GYY4137 is a novel slow‐releasing H 2 S compound that may effectively mimic the time course of H 2 S release in vivo. However, it is not known whether GYY4137 affects atherosclerosis. Experimental Approach: RAW 264.7 cells and human blood monocyte‐derived macrophages were incubated with oxidized low density lipoprotein (ox‐LDL) with/without GYY4137. ApoE−/− mice were fed a high‐fat diet for 4 weeks and administered GYY4137 for 30 days. Lipid and atherosclerotic lesions were measured by oil red O staining. Endothelium‐dependent relaxation was assessed in response to acetylcholine. Superoxide production was detected by dihydroethidium staining. Expression of mRNA and protein were evaluated by quantitative real‐time PCR and Western blot. Key Results: GYY4137 inhibited ox‐LDL‐induced foam cell formation and cholesterol esterification in cultured cells. GYY4137 decreased the expression of lectin‐like ox‐LDL receptor‐1, iNOS, phosphorylated IκBα, NF‐κB, ICAM‐1, VCAM‐1 and chemokines, including CXCL 2, CXCR4, CXCL 10 and CCL 17, but increased the scavenger protein CD36, in ox‐LDL‐treated RAW 264.7 cells. In vivo, GYY4137 decreased aortic atherosclerotic plaque formation and partially restored aortic endothelium‐dependent relaxation in apoE−/− mice. GYY4137 decreased ICAM‐1, TNF‐α and IL‐6 mRNA expression as well as superoxide (O 2−) generation in aorta. In addition, GYY4137 increased aortic eNOS phosphorylation and expression of PI3K, enhanced A kt Ser 473 phosphorylation and down‐regulated the expression of LOX‐1. Conclusion and Implications: GYY4137 inhibits lipid accumulation induced by ox‐LDL in RAW 264.7 cells. In vivo, GYY4137 decreased vascular inflammation and oxidative stress, improved endothelial function and reduced atherosclerotic plaque formation in apo E−/− mice.