Distinct Ca2+ Requirement for NO Production between Proteinase-Activated Receptor 1 and 4 (PAR1 and PAR4) in Vascular Endothelial Cells

2007 ◽  
Vol 322 (2) ◽  
pp. 668-677 ◽  
Author(s):  
Katsuya Hirano ◽  
Namie Nomoto ◽  
Mayumi Hirano ◽  
Fumi Momota ◽  
Akiko Hanada ◽  
...  

Phytomedicine ◽  
2019 ◽  
Vol 52 ◽  
pp. 206-215 ◽  
Author(s):  
Weirong Wang ◽  
Chenxu Shang ◽  
Wei Zhang ◽  
Zhen Jin ◽  
Feng Yao ◽  
...  


2013 ◽  
Vol 33 (7) ◽  
pp. 1663-1669 ◽  
Author(s):  
Taiki Kida ◽  
Yoshiki Tsubosaka ◽  
Masatoshi Hori ◽  
Hiroshi Ozaki ◽  
Takahisa Murata


2012 ◽  
Vol 32 (suppl_1) ◽  
Author(s):  
Taiki Kida ◽  
Yoshiki Tsubosaka ◽  
Masatoshi Hori ◽  
Hiroshi Ozaki ◽  
Takahisa Murata

Objective TGR5, a membrane-bound, G-protein-coupled receptor for bile acids, is known to be involved in regulation of energy homeostasis and inflammation. However, little is known about the function of TGR5 in vascular endothelial cells. In the present study, we examined whether TGR5 agonism represents anti-inflammatory effects in vascular endothelial cells focusing on nitric oxide (NO) production. Methods and Results In human umbilical vein endothelial cells (HUVECs), treatment with taurolithocholic acid (TLCA), which has the highest affinity to TGR5 among various bile acids, significantly reduced tumor necrosis factor (TNF)-α-induced vascular cell adhesion molecule (VCAM)-1 protein expression and adhesion of human monocytes, U937. These effects were abrogated by a NO synthase (NOS) inhibitor, N G -Monomethyl-L-arginine (L-NMMA). In bovine aortic endothelial cells (BAECs), treatment with TLCA as well as lithocholic acid, which also has high affinity to TGR5, significantly increased the NO production. In contrast, deoxycholic acid and chenodeoxycholic acid, which possess low affinity to TGR5, did not affect the NO production. Gene depletion of TGR5 by siRNA transfection abolished TLCA-induced NO production in BAECs. TLCA-induced NO production was also observed in HUVECs measured as intracellular cGMP accumulation. We next investigated the signal pathways responsible for the TLCA-induced NO production in endothelial cells. Treatment with TLCA increased endothelial NOS (eNOS) ser1177 phosphorylation in HUVECs. This response was accompanied by increased Akt ser473 phosphorylation and intracellular Ca 2+ ([Ca 2+ ] i ). Treatment with phosphoinositide 3-kinase (PI3K) inhibitor, LY294002, or blockade of calcium channel with La 3+ , significantly decreased TLCA-induced eNOS ser1177 phosphorylation and subsequent NO production. Conclusion These results indicate that TGR5 agonism can mediate anti-inflammatory responses by suppressing VCAM-1 expression and monocytes adhesion to endothelial cells. This function is dependent on NO production via Akt activation and [Ca 2+ ] i increase.



2020 ◽  
Vol 10 (8) ◽  
pp. 330
Author(s):  
Chiaki Domae ◽  
Hitoshi Ashida ◽  
Yoko Yamashita

Background: Black soybean seed coat contains an abundance of flavan-3-ols and possesses various bioregulatory functions. Nitric oxide (NO) is produced by endothelial nitric oxide synthase (eNOS) in vascular endothelial cells and regulates vascular function through vasodilation and the inhibition of platelet aggregation in blood vessels. It has been reported that flavan-3-ols increase NO production, but many previous reports used a high concentration of flavan-3-ols. In the present study, we investigated the effect of flavan-3-ol-rich black soybean seed coat extract (BE) on NO production at a lower concentration that is close to the concentration after permeation through the monolayer of Caco-2 cells.Methods: Human umbilical vein endothelial cells (HUVEC) were incubated with BE, and then NO production in the medium and eNOS phosphorylation in the cells were examined. Intestinal epithelial Caco-2 cells on the upper side of a transwell filter were co-cultured with HUVEC on the basolateral compartment of the transwell apparatus. BE was added from the upper side, and the basolateral medium was collected to measure the concentration of NO and the content of flavan-3-ols. Furthermore, HUVEC were incubated with each flavan-3-ol in order to individuate the most effective compound in BE.Results: BE significantly increased NO production in the medium of HUVEC. When polyphenols in BE were removed from the basolateral medium by ethyl acetate extraction, increased NO production from HUVEC was not observed. Additionally, BE increased phosphorylation of eNOS and Akt in HUVEC. A portion of flavan-3-ols in BE had permeated through intestinal epithelial cells. Among the flavan-3-ols that had permeated, procyanidin C1 had the strongest effect on NO production in HUVEC at the concentration that had permeated the monolayer of Caco-2 cells. Procyanidin C1 (0.05 µM) also induced phosphorylation of eNOS and Akt in HUVEC without affecting the cAMP level. Conclusion: A portion of flavan-3-ols in BE directly promoted NO production through the Akt/eNOS pathway in vascular endothelial cells. These findings suggest that flavan-3-ols in the black soybean seed coat may contribute to improve the vascular function.Keywords: Black soybean seed coat polyphenols; NO; eNOS; Akt; vascular endothelial cells



1997 ◽  
Vol 272 (6) ◽  
pp. L1161-L1166 ◽  
Author(s):  
A. R. Whorton ◽  
D. B. Simonds ◽  
C. A. Piantadosi

Vascular endothelial cells synthesize nitric oxide (NO) in response to agonists that elevate cytosolic free Ca2+ concentrations. Once activated, NO synthase (NOS) requires arginine, NADPH, and O2 as cosubstrates. In this study, we investigated the role of O2 in regulating endothelial NOS activity in intact bovine aortic endothelial cells by measuring the rate of nitrite (NO2-) and nitrate (NO3-) production after conversion of NO2- to S-nitrosoglutathione before analysis or after reduction of NO2- and NO3- to NO using acidic vanadium chloride. The basal rate of NO2- production was 6.5 +/- 0.8 pmol.min-1.mg protein-1. Thapsigargin (TG, 1 microM) elevated free cytosolic Ca2+ concentration and increased the rate of NO2- synthesis. At maximal concentrations of TG, the rate of stimulated NO2- production was linear for at least 20 min and was eightfold higher than the basal rate (53.5 +/- 1.8 pmol.min-1.mg protein-1). Incubation of cells in gas mixtures chosen to produce PO2 values in the physiological range led to a progressive fall in the rate of TG-stimulated NO2- production, as O2 concentrations were reduced from that of room air. The half-maximal effective concentration for NO2- production by intact cells was found to occur at 38 Torr. PO2 values higher than that of room air did not lead to a change in the rate of TG-stimulated NO2- production. To confirm that measurement of NO2- accurately reflects total NO production, both NO2- plus NO3- were measured in buffer samples from cells incubated in either room air or N2. The sum of these NO oxidation products was inhibited similarly by hypoxia. These findings suggest that O2 is an important determinant of NOS activity in hypoxic tissues or in vascular beds such as the pulmonary arterial or fetal circulation where PO2 values in the range of 40 Torr are encountered normally.



2004 ◽  
Vol 35 (3-4) ◽  
pp. 205-208 ◽  
Author(s):  
Wang Bochu ◽  
Tang Chunhong ◽  
Zhu Liancai ◽  
Chen Qi


2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Richard H. W. Funk ◽  
Lilla Knels ◽  
Antje Augstein ◽  
Rainer Marquetant ◽  
Hermann F. Dertinger

A novel hand-held low-frequency magnetic stimulator (MagCell-SR) was tested for its ability to stimulate microcirculation in fingers of healthy volunteers. Blood flow during and after 5 minutes exposure was quantified using Laser Doppler Perfusion Imaging Technique. The device was positioned between the wrist and the dorsal part of the backhand. Because the increase in blood flow could be caused by a release of nitric oxide (NO) from the vascular endothelial cells we tested NO production with a fluorescence marker and quantified the measurements in cell cultures of human umbilical endothelial cells (HUVEC). Exposure increased blood flow significantly, persisted several minutes, and then disappeared gradually. In order to assess the effect of a static magnetic field, the measurements were also carried out with the device shutoff. Here, only a small increase in blood flow was noted. The application of the rotating MagCell-SR to the HUVEC cultures leads to a rapid onset and a significant increase of NO release after 15 minutes. Thus, frequencies between 4 and 12 Hz supplied by the device improve microcirculation significantly. Therefore, this device can be used in all clinical situations where an improvement of the microcirculation is useful like in chronic wound healing deficits.



2018 ◽  
Vol 41 (7) ◽  
pp. 506-514 ◽  
Author(s):  
Mitsuhiro Nishimoto ◽  
Risuke Mizuno ◽  
Toshiro Fujita ◽  
Masashi Isshiki


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