Cilostazol Reduces Atherosclerosis by Inhibition of Superoxide and Tumor Necrosis Factor-α Formation in Low-Density Lipoprotein Receptor-Null Mice Fed High Cholesterol

Abstract

This study shows that 6-[4-(1-cyclohexyl-1H-tetrazol-5-yl) butoxy]-3,4-dihydro-2(1H)-quinolinone (cilostazol) suppresses the atherosclerotic lesion formation in the low-density lipoprotein receptor (Ldlr)-null mice. Ldlr-null mice fed a high cholesterol diet showed multiple plaque lesions in the proximal ascending aorta including aortic sinus, accompanied by increased macrophage accumulation with increased expression of vascular cell adhesion molecule-1 (VCAM-1) and monocyte chemoattractant protein-1 (MCP-1). Supplementation of cilostazol (0.2% w/w) in diet significantly decreased the plaque lesions with reduced macrophage accumulation and suppression of VCAM-1 and MCP-1 in situ. Increased superoxide and tumor necrosis factor-␣ (TNF-␣) production were significantly lowered by cilostazol in situ as well as in cultured human umbilical vein endothelial cells (HUVECs). TNF-␣-induced increased inhibitory B␣ degradation in the cytoplasm and nuclear factor-B (NF-B) p65 activation in the nuclei of HUVECs were reversed by cilostazol (1 ϳ 100 M) as well as by (E)-3[(4-t-butylphenyl)sulfonyl]-2-propenenitrile (BAY 11-7085) (10 M), suggesting that cilostazol strongly inhibits NF-B activation and p65 translocation into the nuclei. Furthermore, in gel shift and DNA-binding assay, cilostazol inhibited NF-B/DNA complex and nuclear DNA-binding activity of the NF-B in the nuclear extracts of the RAW 264.7 cells. Taken together, it is suggested that the antiatherogenic effect of cilostazol in cholesterol-fed Ldlr-null mice is ascribed to its property to suppress superoxide and TNF-␣ formation, and thereby reducing NF-B activation/transcription, VCAM-1/MCP-1 expressions, and monocyte recruitments.Evidence accumulates that atherogenesis is closely related to the inflammatory and proliferative responses of the endothelium after injury (Ross, 1993). During early stages of the atherosclerosis, adhesion and chemoattractant molecules, including vascular cell adhesion molecule-1 (VCAM-1) and monocyte chemoattractant protein-1 (MCP-1), are secreted by the activated endothelial cells in the atherosclerotic lesions, by which the immune cells and monocytes are recruited and migrated into the intimal area of the vascular wall (Reape and Groot, 1999). Reactive oxygen species and TNF-␣ are critically implicated not only in the induction of endothelial apoptosis (Dimmeler et al., 1998) but also in the development and progression of atherosclerotic lesions in humans (Meyer et al., 1999).Inactive NF-B resides in the cytoplasm bound by its inhibitory subunit, IB␣ (Pahl, 1999). Inflammatory stimuli including TNF-␣ and endotoxin lead to degradation of IB␣ by its phosphorylation pathway (Chen et al., 1995), which allows translocation of active NF-B into the nucleus, where it regulates gene expression and binds to the promoter of the target genes such as VCAM-1 and MCP-1.The low-density lipoprotein receptor (Ldlr)-null mouse is an animal model of homozygous familial hypercholesterolemia characterized by an absence of functional LDL receptors. Th...

Effect of Cilostazol Treatment on Adiponectin and Soluble CD40 Ligand Levels in Diabetic Patients With Peripheral Arterial Occlusion Disease

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Cilostazol improves endothelium-derived hyperpolarizing factor-type relaxation in mesenteric arteries from diabetic rats

“…Several recent studies (3,20,28,41,46) have reported that cilostazol has beneficial effects on the cardiovascular system through several cellular pathways. For instance, cilostazol possesses the ability to inhibit not only PDE3 activity but also adenosine uptake (20,29).…”

Anti-atherogenic Effects of a New Thienylacylhydrazone Derivative, LASSBio-788, in Rats Fed a Hypercholesterolemic Diet

“…Numerous studies have shown that atherogenesis is closely related to the inflammatory and endothelial responses after injury (1,2).…”