scholarly journals Treatment with 2-methoxyestradiol increases endothelial nitric oxide synthase activity via scavenger receptor class BI in human umbilical vein endothelial cells

2020 ◽  
Vol 26 (6) ◽  
pp. 441-451
Author(s):  
Tao Dong ◽  
Seisuke Sato ◽  
Jingya Lyu ◽  
Hitomi Imachi ◽  
Toshihiro Kobayashi ◽  
...  

Abstract Concentrations of 2-methoxyestradiol (2ME2), a principal metabolite of estradiol, are significantly lower in women with severe preeclampsia. Nitric oxide (NO) released by endothelial nitric oxide synthase (eNOS) plays an important role in regulating cardiovascular homeostasis. Importantly, high-density lipoprotein (HDL) stimulates eNOS activity via endothelial human scavenger receptor class B type I (hSR-BI/CLA-1). Here, we aimed to determine the effect of 2ME2 on hSR-BI/CLA-1 expression in human umbilical vein endothelial cells (HUVECs). hSR-BI/CLA-1 expression was measured by real-time PCR, western blotting and reporter gene assays; eNOS activity was assessed by the measurement of eNOS phosphorylation. Both the mRNA and protein concentrations of hSR-BI/CLA-1 were significantly increased by 2ME2 in HUVECs. 2ME2 also dose-dependently increased the transcriptional activity of the hSR-BI/CLA-1 promoter. The effect of 2ME2 treatment on the promoter activity of hSR-BI/CLA-1 was abrogated by treatment with LY294002, a specific inhibitor of phosphatidylinositol 3-kinase, as was the increase in HDL-induced eNOS activation. Notably, constitutively active Akt increased the activity of the hSR-BI/CLA-1 promoter, whereas dominant-negative Akt abolished the effect of 2ME2 treatment on hSR-BI/CLA-1 promoter activity. The nuclear Sp1 protein concentration was significantly increased by exposure to 2ME2 and Sp1 overexpression increased the promoter activity of the hSR-BI/CLA gene. Furthermore, knockdown of Sp1 inhibited the effect of 2ME2 treatment on hSR-BI/CLA-1 protein expression. These results indicate that 2ME2 treatment increases HDL-dependent eNOS phosphorylation by upregulating endothelial hSR-BI/CLA-1 expression, suggesting that 2ME2 has a potential therapeutic value in the treatment of preeclampsia.

2021 ◽  
Vol 22 (19) ◽  
pp. 10287
Author(s):  
Chih-Hsien Wu ◽  
Yi-Lin Chiu ◽  
Chung-Yueh Hsieh ◽  
Guo-Shiang Tsung ◽  
Lian-Shan Wu ◽  
...  

Cilostazol was suggested to be beneficial to retard in-stent atherosclerosis and prevent stent thrombosis. However, the mechanisms responsible for the beneficial effects of cilostazol are not fully understood. In this study, we attempted to verify the mechanism of the antithrombotic effect of cilostazol. Human umbilical vein endothelial cells (HUVECs) were cultured with various concentrations of cilostazol to verify its impact on endothelial cells. KLF2, silent information regulator transcript-1 (SIRT1), endothelial nitric oxide synthase (eNOS), and endothelial thrombomodulin (TM) expression levels were examined. We found cilostazol significantly activated KLF2 expression and KLF2-related endothelial function, including eNOS activation, Nitric oxide (NO) production, and TM secretion. The activation was regulated by SIRT1, which was also stimulated by cilostazol. These findings suggest that cilostazol may be capable of an antithrombotic and vasculoprotective effect in endothelial cells.


2015 ◽  
Vol 29 (8) ◽  
pp. 984-992 ◽  
Author(s):  
Bruno K. Rodiño-Janeiro ◽  
Beatriz Paradela-Dobarro ◽  
Sergio Raposeiras-Roubín ◽  
Mercedes González-Peteiro ◽  
José R. González-Juanatey ◽  
...  

Hypertension ◽  
2015 ◽  
Vol 66 (suppl_1) ◽  
Author(s):  
Lakeisha C Tillery ◽  
Evangeline D Motley-Johnson

Protease-activated receptors (PARs) have been shown to regulate endothelial nitric oxide synthase (eNOS) through the activation of specific sites on the enzyme. It has been established that phosphorylation of eNOS-Ser-1177 leads to the production of the potent vasodilator nitric oxide (NO), and is associated with PAR-2 activation; while phosphorylation of eNOS-Thr-495 decreases NO production, and is coupled to PAR-1 activation. In this study, we demonstrate a differential regulation of the eNOS/NO pathway by the PARs using primary adult human coronary artery endothelial cells (HCAEC). Thrombin and the PAR-1 activating peptide, TFLLR, which are known to phosphorylate eNOS-Thr-495 in bovine and human umbilical vein endothelial cells, phosphorylated eNOS-Ser-1177 in HCAECs, and increased NO production. The PAR-1 responses were blocked using SCH-79797, a PAR-1 inhibitor, and L-NAME was used to inhibit NO production. A PAR-2 specific ligand, SLIGRL, which has been shown to phosphorylate eNOS-Ser-1177 in bovine and human umbilical vein endothelial cells, primarily regulated eNOS-Thr-495 phosphorylation and suppressed NO production in the HCAECs. PAR-3, known for its non-signaling potential, was activated by TFRGAP, a PAR-3 mimicking peptide, and only induced phosphorylation of eNOS-Thr-495 with no effect on NO production. In addition, we confirmed that PAR-mediated eNOS-Ser-1177 phosphorylation was calcium-dependent using the calcium chelator, BAPTA, and eNOS-Thr-495 phosphorylation was mediated via Rho kinase using the ROCK inhibitor, Y-27632. These data suggest a vascular bed specific differential coupling of PARs to the signaling pathways that regulate eNOS and NO production that may be responsible for the modulation of endothelial function associated with cardiovascular disease.


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