scholarly journals Endothelial nitric oxide synthase interactions with G-protein-coupled receptors

1999 ◽  
Vol 343 (2) ◽  
pp. 335-340 ◽  
Author(s):  
Mario B. MARRERO ◽  
Virginia J. VENEMA ◽  
Hong JU ◽  
Han HE ◽  
Haiying LIANG ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Endothelial Cells ◽  
Endothelial Nitric Oxide Synthase ◽  
G Protein Coupled Receptors ◽  
Ang Ii ◽  
Tyrosine Residues ◽  
Oxide Synthase ◽  
Endothelial Nitric Oxide ◽  
G Protein Coupled

The endothelial nitric oxide synthase (eNOS) is activated in response to stimulation of endothelial cells by a number of vasoactive substances including, bradykinin (BK), angiotensin II (Ang II), endothelin-1 (ET-1) and ATP. In the present study we have used in vitro activity assays of purified eNOS and in vitro binding assays with glutathione S-transferase fusion proteins to show that the capacity to bind and inhibit eNOS is a common feature of membrane-proximal regions of intracellular domain 4 of the BK B2, the Ang II AT1 and the ET-1 ETB receptors, but not of the ATP P2Y2 receptor. Phosphorylation of serine or tyrosine residues in the eNOS-interacting region of the B2 receptor results in a loss of eNOS inhibition due to a decrease in the binding affinity of the receptor domain for the eNOS enzyme. Furthermore, the B2 receptor is transiently phosphorylated on tyrosine residues in cultured endothelial cells in response to BK stimulation. Phosphorylation occurs during the time in which eNOS transiently dissociates from the receptor accompanied by a transient increase in nitric oxide production. Taken together, these data support the hypotheses that eNOS is regulated in endothelial cells by reversible and inhibitory interactions with G-protein-coupled receptors and that these interactions can be modulated by receptor phosphorylation.

scholarly journals Endothelial Nitric Oxide Synthase Expression Is Progressively Increased in Primary Cerebral Microvascular Endothelial Cells During Hyperbaric Oxygen Exposure

2009 ◽  
Vol 2 (1) ◽  
pp. 7-13 ◽  
Author(s):  
Xiongfei Xu ◽  
Zhongzhuang Wang ◽  
Quan Li ◽  
Xiang Xiao ◽  
Qinglin Lian ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Endothelial Cells ◽  
Nitric Oxide Synthase ◽  
Hyperbaric Oxygen ◽  
Endothelial Nitric Oxide Synthase ◽  
Microvascular Endothelial Cells ◽  
Oxide Synthase ◽  
Endothelial Nitric Oxide ◽  
Enos Protein

Exposure to hyperbaric oxygen (HBO) can lead to seizures. Many studies have demonstrated that there exist a very close relationship between the alteration of cerebral blood flow (CBF) and the onset of seizures. Nitric oxide (NO) may play a key role in the change of CBF during exposure, and modulation of endothelial nitric oxide synthase (eNOS)-derived NO by HBO is responsible for early vasoconstriction, whereas late HBO-induced vasodilation depends upon a large amount of NO from both eNOS and neuronal nitric oxide synthase (nNOS). To investigate the effect of HBO on the activity and expression of eNOS in cerebral microvascular endothelial cells (CMEC) in vitro, primarily cultured CMEC from neonatal rats were exposed to oxygen at 500 kPa [5 atmosphere absolute (ATA)] for 10, 20, 30, 60 and 120 minutes (min), then eNOS activity, protein and mRNA contents in cells were detected. Our results showed that immediately after exposure, 30, 60 and 120 min HBO exposures did not alter NOS activity. When detected no matter immediately or six hours (h) after exposure, these exposures also did not alter eNOS protein and mRNA levels. However, when detected 24 h after exposure, 30, 60 and 120 min exposures upregulated eNOS protein content by 39%, 60% and 40% respectively. 10 and 20 min exposures upregulated eNOS mRNA content by about 15%, while 30, 60 and 120 min exposures upregulated it by about 20–30%. The increased eNOS protein and mRNA contents at 24 h after exposure may reflect new protein synthesis for eNOS. Our studies showed that with the exposing protocols we used, HBO did induce eNOS expression increase in CMEC. However, compared with the decrease of CBF in vivo, which occurred in a relative short time after rat was exposed to HBO above 4 ATA, the responses of eNOS in CMEC in vitro were a little slow. Thus we considered that for the vasodilation in the late period of HBO exposure before seizure, the effect of NO produced by eNOS was limited.

scholarly journals Shear-induced nitric oxide production by endothelial cells

2016 ◽  
Author(s):  
K. Sriram ◽  
J. G. Laughlin ◽  
P. Rangamani ◽  
D. M. Tartakovsky
Keyword(s):  
Nitric Oxide ◽  
Endothelial Nitric Oxide Synthase ◽  
Calcium Influx ◽  
Cyclic Guanosine Monophosphate ◽  
G Protein Coupled Receptors ◽  
Guanosine Monophosphate ◽  
No Production ◽  
Oxide Synthase ◽  
Endothelial Nitric Oxide ◽  
G Protein Coupled

AbstractWe present a biochemical model of the wall shear stress (WSS)-induced activation of endothelial nitric oxide synthase (eNOS) in an endothelial cell (EC). The model includes three key mechanotransducers: mechanosensing ion channels, integrins and G-protein-coupled receptors. The reaction cascade consists of two interconnected parts. The first is rapid activation of calcium, which results in formation of calcium-calmodulin complexes, followed by recruitment of eNOS from caveolae. The second is phosphoryaltion of eNOS by protein kinases PKC and AKT. The model also includes a negative feedback loop due to inhibition of calcium influx into the cell by cyclic guanosine monophosphate (cGMP). In this feedback, increased nitric oxide (NO) levels cause an increase in cGMP levels, so that cGMP inhibition of calcium influx can limit NO production. The model was used to predict the dynamics of NO production by an EC subjected to a step increase of WSS from zero to a finite physiologically relevant value. Among several experimentally observed features, the model predicts a highly nonlinear, bipha-sic transient behavior of eNOS activation and NO production: a rapid initial activation due to the very rapid influx of calcium into the cytosol (occurring within 1 to 5 minutes) is followed by a sustained period of activation due to protein kinases.AcronymsAKT, protein kinase B; [Ca2+]c, [Ca2+]s, [Ca2+]e and [Ca2+]b, cytosolic, stored, external and buffer concentrations of calcium ions, respectively; Ca3-CaM and Ca4-CaM, calcium-calmodulin complexes with 3 and 4 calcium ions bound to CaM, respectively; CaM, calmodulin; CCE, capacitative calcium entry; cGMP, cyclic guanosine monophosphate; EC, endothelial cell; ECM, extracellular matrix; eNOS, endothelial nitric oxide synthase; eNOScav, eNOS bound to caveolin; eNOS*, eNOS-CaM complex phosphorylated at Ser-1197; eNOS0, caveolin-bound eNOS phosphorylated at Thr-495; ER, endoplasmic reticulum; FAK, focal adhesion kinase; G, active G proteins; Gt, total G proteins; GPCR, G-protein-coupled receptors; Hsp90, heat shock protein 90; GTP, guanosine triphosphate; IP3, inositol triphosphate; L-Arg, L-form of arginine; MSIC, mechanosensing ion channel; NO, nitric oxide; O2, oxygen; PIP2, phosphatidylinositol 4,5-bisphosphate; PIP3, phos-phatidylinositol (3,4,5)-triphosphate; PI3K, phosphatidylinositide 3-kinases; PKC, protein kinase C; RBC, red blood cell; sGC, soluble guanylate cyclase; WSS, wall shear stress

scholarly journals Endothelial nitric oxide synthase interactions with G-protein-coupled receptors

1999 ◽  
Vol 343 (2) ◽  
pp. 335 ◽  
Author(s):  
Mario B. MARRERO ◽  
Virginia J. VENEMA ◽  
Hong JU ◽  
Han HE ◽  
Haiying LIANG ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Nitric Oxide Synthase ◽  
G Protein ◽  
Endothelial Nitric Oxide Synthase ◽  
G Protein Coupled Receptors ◽  
Oxide Synthase ◽  
Endothelial Nitric Oxide ◽  
G Protein Coupled

scholarly journals Rho GTPase/Rho Kinase Negatively Regulates Endothelial Nitric Oxide Synthase Phosphorylation through the Inhibition of Protein Kinase B/Akt in Human Endothelial Cells

2002 ◽  
Vol 22 (24) ◽  
pp. 8467-8477 ◽  
Author(s):  
Xiu-Fen Ming ◽  
Hema Viswambharan ◽  
Christine Barandier ◽  
Jean Ruffieux ◽  
Kozo Kaibuchi ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Endothelial Cells ◽  
Endothelial Nitric Oxide Synthase ◽  
Rho Gtpase ◽  
Protein Kinase B ◽  
Rho Kinase ◽  
Enos Expression ◽  
Enos Phosphorylation ◽  
Oxide Synthase ◽  
Endothelial Nitric Oxide

ABSTRACT Endothelial nitric oxide synthase (eNOS) is an important regulator of cardiovascular homeostasis by production of nitric oxide (NO) from vascular endothelial cells. It can be activated by protein kinase B (PKB)/Akt via phosphorylation at Ser-1177. We are interested in the role of Rho GTPase/Rho kinase (ROCK) pathway in regulation of eNOS expression and activation. Using adenovirus-mediated gene transfer in human umbilical vein endothelial cells (HUVECs), we show here that both active RhoA and ROCK not only downregulate eNOS gene expression as reported previously but also inhibit eNOS phosphorylation at Ser-1177 and cellular NO production with concomitant suppression of PKB activation. Moreover, coexpression of a constitutive active form of PKB restores the phosphorylation but not gene expression of eNOS in the presence of active RhoA. Furthermore, we show that thrombin inhibits eNOS phosphorylation, as well as expression via Rho/ROCK pathway. Expression of the active PKB reverses eNOS phosphorylation but has no effect on downregulation of eNOS expression induced by thrombin. Taken together, these data demonstrate that Rho/ROCK pathway negatively regulates eNOS phosphorylation through inhibition of PKB, whereas it downregulates eNOS expression independent of PKB.

Sign in / Sign up

Export Citation Format

Share Document