scholarly journals The effects of hyperuricemia on endothelial cells are mediated via GLUT9 and the JAK2/STAT3 pathway

Author(s):  
Qian Nie ◽  
Miaomiao Liu ◽  
Zhimei Zhang ◽  
Xuemei Zhang ◽  
Chao Wang ◽  
...  

Abstract Background Uric acid (UA) transporters mediate the uptake and outflow of UA, and are greatly involved in the control of UA concentrations. Glucose transporter 9 (GLUT9), one of the UA transporters, has been confirmed to be expressed in human umbilical vein endothelial cells (HUVECs). This study aimed to characterize GLUT9’s effect on intracellular UA accumulation in HUVECs in a high-UA environment and to explore the mechanism of cellular dysfunction. Methods and results HUVECs were treated with UA to establish a model of cellular dysfunction. Then, UA uptake, GLUT9 expression and endothelial nitric oxide synthase (eNOS) and reactive oxygen species (ROS) amounts were measured. UA uptake was concentration- and time-dependent, and UA treatment significantly reduced nitric oxide (NO) levels and eNOS activity. UA also upregulated pro-inflammatory molecules and GLUT9, and increased intracellular ROS amounts in HUVECs. GLUT9 knockdown reduced UA uptake and ROS content, but antioxidant treatment did not reduce GLUT9 expression. To assess the function of JAK2/STAT3 signaling, HUVECs were treated with UA, and the phosphorylation levels of JAK2, STAT3, IL-6 and SOCS3 were increased by a high concentration of UA. In addition, GLUT9 knockdown reduced the phosphorylation of JAK2/STAT3 intermediates and increased p-eNOS amounts. Conclusions GLUT9 mediated the effects of high UA levels on HUVECs by increasing the cellular uptake of UA, activating JAK2/STAT3 signaling, and reduced the production of active eNOS and NO in HUVECs.

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.


2013 ◽  
Vol 305 (7) ◽  
pp. H969-H979 ◽  
Author(s):  
Jennifer Krupp ◽  
Derek S. Boeldt ◽  
Fu-Xian Yi ◽  
Mary A. Grummer ◽  
Heather A. Bankowski Anaya ◽  
...  

Approximately 8% of pregnancies are complicated by preeclampsia (PE), a hypertensive condition characterized by widespread endothelial dysfunction. Reduced nitric oxide (NO) output in PE subjects has been inferred but not directly measured, and there is little understanding of why this occurs. To address this we have used direct imaging of changes in intracellular Ca2+ concentration ([Ca2+]i) and NO in umbilical vein endothelium of normal and PE subjects that is still intact and on the vessel luminal surface. This was achieved by dissection and preloading with fura 2 and DAF-2 imaging dyes, respectively, before subsequent challenge with ATP (100 μM, 30 min). As a control to reveal the content of active endothelial nitric oxide synthase (eNOS) per vessel segment, results were compared with a maximal stimulus with ionomycin (5 μM, 30 min). We show for the first time that normal umbilical vein endothelial cells respond to ATP with sustained bursting that parallels sustained NO output. Furthermore, in subjects with PE, a failure of sustained [Ca2+]i bursting occurs in response to ATP and is associated with blunted NO output. In contrast, NO responses to maximal [Ca2+]i elevation using ionomycin and the levels of eNOS protein are more similar between groups than the responses to ATP. When the endothelial cells from PE subjects are isolated and allowed to recover in culture, they regain the ability under fura 2 imaging to show multiple [Ca2+]i bursts otherwise seen in the cells from normal subjects. Thus novel clinical therapy aimed at restoring function in vivo may be possible.


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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