Effects Of PGE1 On Production Of NO And Activity Of ENOS From Human Umbilical Vein Endothelial Cells

Endothelial dysfunction is associated with most forms of cardiovascular disease, such as hypertension, coronary artery disease, chronic heart failure, peripheral artery disease. Nitric oxide (NO) is a pivotal endothelium-derived substance, derived from its precursor L-arginine via the enzymatic action of endothelial NO synthase (eNOS). The hallmark of endothelial dysfunction is impaired endothelium dependent vasodilation, which is mediated by NO. A defect in NO production or activity has been proposed as a major mechanism of endothelial dysfunction and a contributor to atherosclerosis. Inflammatory factors, such as TNF-α, IL-1β induce vascular endothelial a proinflammatory and prothrombic state, inhibit the activation of eNOS , increase the activation of iNOS, affect the synthesis and release of NO, therefore, impair the endothelial function. Prostaglandin 1(PGE1) as a protect factor derived from vascular endothelial cells, have a protect function through various mechanisms.PGEl improve peripheral circulation by vasodilation, inhibit platelet aggregation and prevent thrombogenesis, and improve ischemic myocardium, which is generallyused to coronary heart disease, heart failure, hyperlipemia, diabetic neuropathy and chronic renal insufficiency. The mechanisms by which it alters the function of the vascular endothelial cell remain largely unknown.Therefore, we investigate the effects of PGEl on production of NO and eNOS from human umbilical vein endothelial cells (HUVECs), to explore the potential mechanism of PGE1 on cardiovascular disease. Methods1. HUVECs Culture: HUVECs were isolated by collagenase type I, digestion of human umbilical veins by means of standard techniques, and cultured in M199 medium with 15% fetal calf serum(FCS) and epidermal growth factor (EGF, 10 ng/mL). The medium was refreshed every 2-3 days. Cells were grown to near confluence and the medium replaced with fresh culture medium for 24h prior to treatment with homocysteine. The purity of EC cultures was checked by expression of factor Ⅷ and found to be greater than 99% positive.2. HUVECs were exposed to PGEl at different concentration (0.04ug/ml,0.1 ug/ml,0.2 ug/ml, 0.3 ug/ml,0.4 ug/ml) for 24h and different time (3h, 6h, 12h, 24h, 48h) at the concentration of 0.4 ug/ml. After these treatments, NO in cell supernatant was determined by NO kit;the activity of NOS was determined by NOS kit.Results1. Activity of eNOS and expression of NO was up-regulated by PGE1 inconcentration-dependent manner (P<0.05).2. Short-time intervention with PGEl had no effect on both activity of eNOS and expression of NO. The activation of eNOS increased after 24 hours(P<0.05), and the release of NO increased after 12 hours (P<0.05).3. PGEl could induce activition of eNOS which was inhibited by TNF-a. Conclusion1. PGEl may induce the expression of eNOS in HUVECs, and enhance release of NO2. PGEl could active eNOS which was inhibited by TNF-a.