scholarly journals The role of HYAL2 in LSS-induced glycocalyx impairment and the PKA-mediated decrease in eNOS–Ser-633 phosphorylation and nitric oxide production

2016 ◽  
Vol 27 (25) ◽  
pp. 3972-3979 ◽  
Author(s):  
Xiangquan Kong ◽  
Liang Chen ◽  
Peng Ye ◽  
Zhimei Wang ◽  
Junjie Zhang ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Shear Stress ◽  
Umbilical Vein ◽  
Endothelial Glycocalyx ◽  
No Production ◽  
Enos Phosphorylation ◽  
Umbilical Vein Endothelial Cells ◽  
Oxide Synthase ◽  
Endothelial Nitric Oxide

Hyaluronan (HA) in the endothelial glycocalyx serves as a mechanotransducer for high-shear-stress–stimulated endothelial nitric oxide synthase (eNOS) phosphorylation and nitric oxide (NO) production. Low shear stress (LSS) has been shown to contribute to endothelial inflammation and atherosclerosis by impairing the barrier and mechanotransduction properties of the glycocalyx. Here we focus on the possible role of hyaluronidase 2 (HYAL2) in LSS-induced glycocalyx impairment and the resulting alterations in eNOS phosphorylation and NO production in human umbilical vein endothelial cells (HUVECs). We show that LSS strongly activates HYAL2 to degrade HA in the glycocalyx. The dephosphorylation of eNOS–Ser-633 under LSS was triggered after HA degradation by hyaluronidase and prevented by repairing the glycocalyx with high–molecular weight hyaluronan. Knocking down HYAL2 in HUVECs protected against HA degradation in the glycocalyx by inhibiting the expression and activity of HYAL2 and further blocked the dephosphorylation of eNOS–Ser-633 and the decrease in NO production in response to LSS. The LSS-induced dephosphorylation of PKA was completely abrogated in HYAL2 siRNA–transfected HUVECs. The LSS-induced dephosphorylation of eNOS–Ser-633 was also reversed by the PKA activator 8-Br-cAMP. We thus suggest that LSS inhibits eNOS–Ser-633 phosphorylation and, at least partially, NO production by activating HYAL2 to degrade HA in the glycocalyx.

scholarly journals Cilostazol Induces eNOS and TM Expression via Activation with Sirtuin 1/Krüppel-like Factor 2 Pathway in Endothelial Cells

2021 ◽  
Vol 22 (19) ◽  
pp. 10287
Author(s):  
Chih-Hsien Wu ◽  
Yi-Lin Chiu ◽  
Chung-Yueh Hsieh ◽  
Guo-Shiang Tsung ◽  
Lian-Shan Wu ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Endothelial Cells ◽  
Endothelial Nitric Oxide Synthase ◽  
Umbilical Vein ◽  
Sirtuin 1 ◽  
No Production ◽  
Beneficial Effects ◽  
Umbilical Vein Endothelial Cells ◽  
Oxide Synthase ◽  
Endothelial Nitric Oxide

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.

Abstract P198: Differential Regulation of Endothelial Nitric Oxide Synthase Phosphorylation by Protease-Activated Receptors in Adult Human Endothelial Cells

Hypertension ◽  
2015 ◽  
Vol 66 (suppl_1) ◽  
Author(s):  
Lakeisha C Tillery ◽  
Evangeline D Motley-Johnson
Keyword(s):  
Nitric Oxide ◽  
Endothelial Cells ◽  
Endothelial Nitric Oxide Synthase ◽  
Umbilical Vein ◽  
Differential Regulation ◽  
No Production ◽  
Protease Activated Receptors ◽  
Umbilical Vein Endothelial Cells ◽  
Oxide Synthase ◽  
Endothelial Nitric Oxide

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.

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 ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Endothelial Nitric Oxide Synthase ◽  
Promoter Activity ◽  
Umbilical Vein ◽  
Scavenger Receptor ◽  
Scavenger Receptor Class ◽  
Enos Phosphorylation ◽  
Umbilical Vein Endothelial Cells ◽  
Oxide Synthase ◽  
Endothelial Nitric Oxide

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.

scholarly journals Mechanism of endothelial nitric oxide synthase phosphorylation and activation by tentacle extract from the jellyfishCyanea capillata

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3172 ◽  
Author(s):  
Beilei Wang ◽  
Dan Liu ◽  
Chao Wang ◽  
Qianqian Wang ◽  
Hui Zhang ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Kinase Inhibitor ◽  
Umbilical Vein ◽  
Critical Role ◽  
No Production ◽  
Enos Activity ◽  
Enos Phosphorylation ◽  
Isolated Aorta ◽  
Umbilical Vein Endothelial Cells

Our previous study demonstrated that tentacle extract (TE) from the jellyfishCyanea capillata(C. capillata) could cause a weak relaxation response mediated by nitric oxide (NO) using isolated aorta rings. However, the intracellular mechanisms of TE-induced vasodilation remain unclear. Thus, this study was conducted to examine the role of TE on Akt/eNOS/NO and Ca2+signaling pathways in human umbilical vein endothelial cells (HUVECs). Our results showed that TE induced dose- and time-dependent increases of eNOS activity and NO production. And TE also induced Akt and eNOS phosphorylation in HUVECs. However, treatment with specific PI3-kinase inhibitor (Wortmannin) significantly inhibited the increases in NO production and Akt/eNOS phosphorylation. In addition, TE also stimulated an increase in the intracellular Ca2+concentration ([Ca2+]i), which was significantly attenuated by either IP3receptor blocker (Heparin) or PKC inhibitor (PKC 412). In contrast, extracellular Ca2+-free, L-type calcium channel blocker (Nifedipine), or PKA inhibitor (H89) had no influence on the [Ca2+]ielevation. Since calcium ions also play a critical role in stimulating eNOS activity, we next explored the role of Ca2+in TE-induced Akt/eNOS activation. In consistent with the attenuation of [Ca2+]ielevation, we found that Akt/eNOS phosphorylation was also dramatically decreased by Heparin or PKC 412, but not affected by Nifedipine or H89. However, the phosphorylation level could also be decreased by the removal of extracellular calcium. Taken together, our findings indicated that TE-induced eNOS phosphorylation and activation were mainly through PI3K/Akt-dependent, PKC/IP3R-sensitive and Ca2+-dependent pathways.

Abstract P069: Microvesicles From Enos-suppressed Endothelial Cells Induce Endothelial Cell Dysfunction

Hypertension ◽  
2020 ◽  
Vol 76 (Suppl_1) ◽  
Author(s):  
Vinicius P Garcia ◽  
Jamie G Hijmans ◽  
Kelly A Stockelman ◽  
Madden Brewster ◽  
Hannah Fandl ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Umbilical Vein ◽  
No Production ◽  
Cell Dysfunction ◽  
Enos Activity ◽  
Umbilical Vein Endothelial Cells ◽  
And Function ◽  
Oxide Synthase ◽  
Endothelial Nitric Oxide

Introduction: Endothelial nitric oxide synthase (eNOS) activity is critical to vascular health. Impaired eNOS activity and diminished NO production are common characteristics of a proatherogenic, dysfunctional endothelial phenotype that is associated with cardiovascular risk factors and disease. Extracellular microvesicles, particularly endothelial cell derived microvesicles (EMVs) represent novel mechanistic mediators of endothelial dysfunction and vascular disease. It is unknown whether eNOS suppression affects EMV number and function. We tested the following hypotheses: 1) eNOS blockade increases EMV release; and 2) EMVs derived from eNOS-suppressed cells adversely affect endothelial cell inflammation, apoptosis and NO production. Methods: Human umbilical vein endothelial cells (HUVECs) were treated with the eNOS inhibitor, L-N G -Nitroarginine methyl ester (L-NAME; 300mM) for 24 h. EMVs (CD144 + ) released into the supernatant from cells treated with L-NAME or vehicle were isolated and quantified by flow cytometry. Fresh HUVECs were then treated with either L-NAME-derived or control EMVs for 24 h. To evaluate the role of endocytosis on the endothelial effects of EMVs, HUVECs were pre-incubated (12 h) with EIPA, filipin and chlorpromazine for 2 h, and all experiments repeated. Results: EMV release was markedly higher (~100%; P<0.05) in cells treated with L-NAME compared with control (81±6 vs. 40±7 EMV/μL). L-NAME-generated EMVs induced significantly higher release of IL-6 (38.4±5.1 vs. 21.0±1.9 pg/mL) and IL-8 (38.9±3.5 vs. 27.2±3.1 pg/mL) as well as greater active NF-κB p65 (Ser-536) (9.7±0.7 vs. 6.1±0.6 AU) expression than control EMVs. The expression of activated-caspase-3 was significantly higher in the cells treated with L-NAME (9.5±1.1 vs. 6.4±0.4 AU). Total eNOS (97.1±8.2 vs. 157.5±15.6 AU), activated eNOS (4.9±1.2 vs. 9.1±1.3 AU) and NO production (5.0±0.8 vs. 7.0±0.6 μmol/L) were significantly lower in endothelial cells treated with EMVs from eNOS suppressed cells. Endocytosis blockers mitigated the deleterious endothelial effects of EMVs. Conclusion: eNOS-suppression increases EMV release. Moreover, EMVs from eNOS-suppressed cells increase endothelial cell inflammation and apoptosis and decrease NO production.

scholarly journals Exacerbation of endothelial dysfunction during the progression of diabetes: role of oxidative stress

2012 ◽  
Vol 302 (6) ◽  
pp. R674-R681 ◽  
Author(s):  
An Huang ◽  
Yang-Ming Yang ◽  
Attila Feher ◽  
Zsolt Bagi ◽  
Gabor Kaley ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Shear Stress ◽  
Endothelial Dysfunction ◽  
Nadph Oxidase ◽  
Nitrosative Stress ◽  
Mesenteric Arteries ◽  
Enos Phosphorylation ◽  
Oxidase Inhibition ◽  
Oxide Synthase ◽  
Endothelial Nitric Oxide

To test the deterioration of endothelial function during the progression of diabetes, shear stress-induced dilation (SSID; 10, 20, and 40 dyn/cm2) was determined in isolated mesenteric arteries (80–120 μm in diameter) of 6-wk (6W), 3-mo (3M), and 9-mo (9M)-old male db/db mice and their wild-type (WT) controls. Nitric oxide (NO)-mediated SSID was comparable in 6W WT and db/db mice, but the dilation was significantly reduced in 3M db/db mice and declined further in 9M db/db mice. Vascular superoxide production was progressively increased in 3M and 9M db/db mice, associated with an increased expression of NADPH oxidase. Inhibition of NADPH oxidase significantly improved NO-mediated SSID in arteries of 3M, but not in 9M, db/db mice. Although endothelial nitric oxide synthase (eNOS) expression was comparable in all groups, a progressive reduction in shear stress-induced eNOS phosphorylation existed in vessels of 3M and 9M db/db mice. Moreover, inducible NOS (iNOS) that was not detected in WT, nor in 6W and 3M db/db mice, was expressed in vessels of 9M db/db mice. A significantly increased expression of nitrotyrosine in total protein and immunoprecipitated eNOS was also found in vessels of 9M db/db mice. Thus, impaired NO bioavailability plays an essential role in the endothelial dysfunction of diabetic mice, which becomes aggravated when endothelial nitrosative stress is further activated via perhaps, an additional iNOS-mediated pathway during the progression of diabetes.

Endothelial nitric oxide production during in vitro simulation of external limb compression

2002 ◽  
Vol 282 (6) ◽  
pp. H2066-H2075 ◽  
Author(s):  
Guohao Dai ◽  
Olga Tsukurov ◽  
Michael Chen ◽  
Jonathan P. Gertler ◽  
Roger D. Kamm
Keyword(s):  
Nitric Oxide ◽  
Mrna Expression ◽  
Umbilical Vein ◽  
Control Group ◽  
No Production ◽  
Vein Thrombosis ◽  
Enos Mrna ◽  
Umbilical Vein Endothelial Cells ◽  
Endothelial Nitric Oxide

External pneumatic compression (EPC) is effective in preventing deep vein thrombosis (DVT) and is thought to alter endothelial thromboresistant properties. We investigated the effect of EPC on changes in nitric oxide (NO), a critical mediator in the regulation of vasomotor and platelet function. An in vitro cell culture system was developed to simulate flow and vessel collapse conditions under EPC. Human umbilical vein endothelial cells were cultured and subjected to tube compression (C), pulsatile flow (F), or a combination of the two (FC). NO production and endothelial nitric oxide synthase (eNOS) mRNA expression were measured. The data demonstrate that in the F and FC groups, there is a rapid release of NO followed by a sustained increase. NO production levels in the F and FC groups were almost identical, whereas the C group produced the same low amount of NO as the control group. Conditions F and FC also upregulate eNOS mRNA expression by a factor of 2.08 ± 0.25 and 2.11 ± 0.21, respectively, at 6 h. Experiments with different modes of EPC show that NO production and eNOS mRNA expression respond to different time cycles of compression. These results implicate enhanced NO release as a potentially important factor in the prevention of DVT.

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