Transcriptional Stimulation of the eNOS Gene by the Stable Prostacyclin Analogue Beraprost Is Mediated Through cAMP-Responsive Element in Vascular Endothelial Cells

Abstract

Abstract-Beraprost sodium (BPS), an orally active prostacyclin analogue, has been reported to be beneficial in the treatment of primary pulmonary hypertension and obstructive peripheral arterial disease. Although BPS was originally described for its effects on platelet aggregation and vasodilatory response, the effect on endothelial cells has been poorly understood. In this study, we examined the effects of BPS on the eNOS gene expression in mouse aorta and cultured human and bovine aortic endothelial cells. Treatment of these cells with BPS increased the eNOS expression as assessed by Northern blots, Western blots, and NO production by NO-specific fluorescence (DAF2-DA) and by the Griess method. Standard mRNA decay assays showed that BPS increases the stability of eNOS mRNA. In addition, BPS increased the promoter activity of the human eNOS gene, as determined by luciferase assays of the eNOS promoter gene. Progressive 5Ј-deletion and site-specific mutation analyses defined the BPS-responsive sequences as cAMPresponsive elements (CRE) located at Ϫ733 and Ϫ603. By using the oligonucleotide probe containing this CRE sequence in electrophoretic mobility shift assays, we showed that the phosphorylated form of CRE-binding protein is a major constituent of the complex in BPS-treated cells.

The G-protein coupled bile salt receptor TGR5 is expressed in liver sinusoidal endothelial cells

“…46 In line with this, a fourfold increase in eNOS expression was found in cirrhotic as compared with noncirrhotic human livers. 47 Because bile salts are increased in cirrhosis and the promoter of the human eNOS contains a cAMP-responsive elements, 48 the increase in eNOS expression in cirrhotic livers may be partly mediated by the "bile salt-TGR5-cAMP pathway" as supported by our data. Apart from effects of NO on vascular resistance, NO may protect from oxidative stress and lipid peroxidation.…”

Eicosapentaenoic Acid (EPA) Reduces Cardiovascular Events: Relationship with the EPA/Arachidonic Acid Ratio

“…In their physiological state, PGI2 and NO play complementary roles in vasodilation 56) . At the same time, PGI2 regulates the endothelial function via crosstalk with endothelial nitric oxide synthase (eNOS) 57) . This indicates that NO activates PGI2 synthase and increases PGI2 production 58) .…”

Protective effects of prostaglandin E1 on human umbilical vein endothelial cell injury induced by hydrogen peroxide

“…PGE 1 activates adenylate cyclase and increases intracellular cAMP via binding to prostanoid receptor subtypes EP2, EP3, EP4, and IP [31] . The cAMP-responsive elements (CRE) within the human eNOS promoter play an important role in the inducible expression of the human eNOS gene [32,33] . Progressive 5′-deletion and site-specific mutation analyses defined the beraprost-responsive sequences as CRE, located at -733 and -603 within the human eNOS promoter [32,33] , and the hypoxia- [34] , while the PGE 1 -responsive sequences are still unclear.…”

“…PGE 1 increases eNOS expression through PKA pathway activation and cAMPresponsive element binding protein (CREB) phosphorylation. Phosphorylated CREB predominantly binds to CRE, which leads to increased promoter activity and upregulation of the eNOS protein and mRNA expression [32][33][34] . Previous studies have also reported that PKA signaling increased phosphorylation of Ser-1177 and dephosphorylation of Thr-495 to activate eNOS, which led to the upregulation of NO [35] .…”