scholarly journals Membrane Estrogen Receptor-Dependent Extracellular Signal-Regulated Kinase Pathway Mediates Acute Activation of Endothelial Nitric Oxide Synthase by Estrogen in Uterine Artery Endothelial Cells

Endocrinology ◽  
2004 ◽  
Vol 145 (1) ◽  
pp. 113-125 ◽  
Author(s):  
Dong-bao Chen ◽  
Ian M. Bird ◽  
Jing Zheng ◽  
Ronald R. Magness

Abstract Rapid uterine vasodilatation after estrogen administration is believed to be mediated by endothelial production of nitric oxide (NO) via endothelial NO synthase (eNOS). However, the mechanism(s) by which estrogen activates eNOS in uterine artery endothelial cells (UAEC) is unknown. In this study, we observed that estradiol-17β (E2) and E2-BSA rapidly (<2 min) increased total NOx production in UAEC in vitro. This was associated with rapid eNOS phosphorylation and activation but was unaltered by pretreatment with actinomycin-D. estrogen receptor-α protein was detectable in isolated plasma membrane proteins by immunoblotting, and E2-BSA-fluorescein isothiocyanate binding was evident on the plasma membrane of UAEC. E2 did not mobilize intracellular Ca2+, but E2 and ionomycin in combination induced greater eNOS phosphorylation than either E2 or ionomycin alone. E2 did not stimulate rapid Akt phosphorylation. E2 stimulated rapid ERK2/1 activation in a time- and dose-dependent manner, with maximal responses observed at 5–10 min with E2 (10 nm to 1 μm) treatment. Acute activation of eNOS and NOx production by E2 could be inhibited by PD98059 but not by LY294002. When E2-BSA was applied, similar responses in NOx production, eNOS, and ERK2/1 activation to those of E2 were achieved. In addition, E2 and E2-BSA-induced ERK2/1 activation and ICI 182,780 could inhibit NOx production by E2. Thus, acute activation of eNOS to produce NO in UAEC by estrogen is at least partially through an ERK pathway, possibly via estrogen receptor localized on the plasma membrane. This pathway may provide a novel mechanism for NO-mediated rapid uterine vasodilatation by estrogen.

Blood ◽  
1998 ◽  
Vol 92 (9) ◽  
pp. 3268-3276 ◽  
Author(s):  
Chia Hsin Yeh ◽  
Hui-Chin Peng ◽  
Tur-Fu Huang

Abstract Endothelial integrins play an essential role in angiogenesis and cell survival. Accutin, a new member of disintegrin family derived from venom of Agkistrodon acutus, potently inhibited human platelet aggregation caused by various agonists (eg, thrombin, collagen, and, adenosine diphosphate [ADP]) through the blockade of fibrinogen binding to platelet glycoprotein IIb/IIIa (ie, integrin IIbβ3). In this report, we describe that accutin specifically inhibited the binding of monoclonal antibody (MoAb) 7E3, which recognizes integrin vβ3, to human umbilical vein endothelial cells (HUVECs), but not those of other anti-integrin MoAbs such as 2β1, 3β1, and 5β1. Moreover, accutin, but not the control peptide GRGES, dose-dependently inhibited the 7E3 interaction with HUVECs. Both 7E3 and GRGDS, but not GRGES or Integrelin, significantly blocked fluorescein isothiocyanate-conjugated accutin binding to HUVEC. In functional studies, accutin exhibited inhibitory effects on HUVEC adhesion to immobilized fibrinogen, fibronectin and vitronectin, and the capillary-like tube formation on Matrigel in a dose- and RGD-dependent manner. In addition, it exhibited an effective antiangiogenic effect in vivo when assayed by using the 10-day-old embryo chick CAM model. Furthermore, it potently induced HUVEC apoptotic DNA fragmentation as examined by electrophoretic and flow cytometric assays. In conclusion, accutin inhibits angiogenesis in vivo and in vitro by blocking integrin vβ3 of endothelial cells and by inducing apoptosis. The antiangiogenic activity of disintegrins might be explored as the target of developing the potential antimetastatic agents. © 1998 by The American Society of Hematology.


2011 ◽  
Vol 301 (3) ◽  
pp. H803-H812 ◽  
Author(s):  
Anne R. Diers ◽  
Katarzyna A. Broniowska ◽  
Victor M. Darley-Usmar ◽  
Neil Hogg

S-nitrosation of thiols in key proteins in cell signaling pathways is thought to be an important contributor to nitric oxide (NO)-dependent control of vascular (patho)physiology. Multiple metabolic enzymes are targets of both NO and S-nitrosation, including those involved in glycolysis and oxidative phosphorylation. Thus it is important to understand how these metabolic pathways are integrated by NO-dependent mechanisms. Here, we compared the effects of NO and S-nitrosation on both glycolysis and oxidative phosphorylation in bovine aortic endothelial cells using extracellular flux technology to determine common and unique points of regulation. The compound S-nitroso-l-cysteine (l-CysNO) was used to initiate intracellular S-nitrosation since it is transported into cells and results in stable S-nitrosation in vitro. Its effects were compared with the NO donor DetaNONOate (DetaNO). DetaNO treatment caused only a decrease in the reserve respiratory capacity; however, l-CysNO impaired both this parameter and basal respiration in a concentration-dependent manner. In addition, DetaNO stimulated extracellular acidification rate (ECAR), a surrogate marker of glycolysis, whereas l-CysNO stimulated ECAR at low concentrations and inhibited it at higher concentrations. Moreover, a temporal relationship between NO- and S-nitrosation-mediated effects on metabolism was identified, whereby NO caused a rapid impairment in mitochondrial function, which was eventually overwhelmed by S-nitrosation-dependent processes. Taken together, these results suggest that severe pharmacological nitrosative stress may differentially regulate metabolic pathways through both intracellular S-nitrosation and NO-dependent mechanisms. Moreover, these data provide insight into the role of NO and related compounds in vascular (patho)physiology.


Endocrinology ◽  
2010 ◽  
Vol 151 (4) ◽  
pp. 1822-1828 ◽  
Author(s):  
Jing Yu ◽  
Masahiro Akishita ◽  
Masato Eto ◽  
Sumito Ogawa ◽  
Bo-Kyung Son ◽  
...  

The mechanisms of testosterone-induced vasodilatation are not fully understood. This study investigated the effect of testosterone on nitric oxide (NO) synthesis and its molecular mechanism using human aortic endothelial cells (HAEC). Testosterone at physiological concentrations (1–100 nm) induced a rapid (15–30 min) increase in NO production, which was associated with phosphorylation and activation of endothelial NO synthase (eNOS). Then, the involvement of the androgen receptor (AR), which is abundantly expressed in HAEC, was examined. The effect of testosterone on eNOS activation and NO production were abolished by pretreatment with an AR antagonist nilutamide and by transfection with AR small interference RNA. In contrast, testosterone-induced eNOS phosphorylation was unchanged by pretreatment with an aromatase inhibitor or by transfection with ERα small interference RNA. 5α-Dihydrotestosterone, a nonaromatizable androgen, also stimulated eNOS phosphorylation. Next, the signaling cascade that leads to eNOS phosphorylation was explored. Testosterone stimulated rapid phosphorylation of Akt in a time- and dose-dependent manner, with maximal response at 15–60 min. The rapid phosphorylation of eNOS or NO production induced by testosterone was inhibited by Akt inhibitor SH-5 or by phosphatidylinositol (PI) 3-kinase inhibitor wortmannin. Co-immunoprecipitation assays revealed a testosterone-dependent interaction between AR and the p85α subunit of PI3-kinase. In conclusion, testosterone rapidly induces NO production via AR-dependent activation of eNOS in HAEC. Activation of PI3-kinase/Akt signaling and the direct interaction of AR with p85α are involved, at least in part, in eNOS phosphorylation.


2005 ◽  
Vol 16 (1) ◽  
pp. 231-237 ◽  
Author(s):  
Filippo Acconcia ◽  
Paolo Ascenzi ◽  
Alessio Bocedi ◽  
Enzo Spisni ◽  
Vittorio Tomasi ◽  
...  

A fraction of the nuclear estrogen receptor α (ERα) is localized to the plasma membrane region of 17β-estradiol (E2) target cells. We previously reported that ERα is a palmitoylated protein. To gain insight into the molecular mechanism of ERα residence at the plasma membrane, we tested both the role of palmitoylation and the impact of E2 stimulation on ERα membrane localization. The cancer cell lines expressing transfected or endogenous human ERα (HeLa and HepG2, respectively) or the ERα nonpalmitoylable Cys447Ala mutant transfected in HeLa cells were used as experimental models. We found that palmitoylation of ERα enacts ERα association with the plasma membrane, interaction with the membrane protein caveolin-1, and nongenomic activities, including activation of signaling pathways and cell proliferation (i.e., ERK and AKT activation, cyclin D1 promoter activity, DNA synthesis). Moreover, E2 reduces both ERα palmitoylation and its interaction with caveolin-1, in a time- and dose-dependent manner. These data point to the physiological role of ERα palmitoylation in the receptor localization to the cell membrane and in the regulation of the E2-induced cell proliferation.


2018 ◽  
Vol 96 (9) ◽  
pp. 879-885 ◽  
Author(s):  
Thanaporn Sriwantana ◽  
Pornpun Vivithanaporn ◽  
Kittiphong Paiboonsukwong ◽  
Krit Rattanawonsakul ◽  
Sirada Srihirun ◽  
...  

Iron chelation can improve endothelial function. However, effect on endothelial function of deferiprone has not been reported. We hypothesized deferiprone could promote nitric oxide (NO) production in endothelial cells. We studied effects of deferiprone on blood nitrite and blood pressure after single oral dose (25 mg/kg) in healthy subjects and hemoglobin E/β-thalassemia patients. Further, effects of deferiprone on NO production and endothelial NO synthase (eNOS) phosphorylation in primary human pulmonary artery endothelial cells (HPAEC) were investigated in vitro. Blood nitrite levels were higher in patients with deferiprone therapy than those without deferiprone (P = 0.023, n = 16 each). Deferiprone increased nitrite in plasma and whole blood of healthy subjects (P = 0.002 and 0.044) and thalassemia patients (P = 0.003 and 0.046) at time 180 min (n = 20 each). Asymptomatic reduction in diastolic blood pressure (P = 0.005) and increase in heart rate (P = 0.009) were observed in healthy subjects, but not in thalassemia patients. In HPAEC, deferiprone increased cellular nitrite and phospho-eNOS (Ser1177) (P = 0.012 and 0.035, n = 6) without alteration in total eNOS protein and mRNA. We conclude that deferiprone can induce NO production by enhancing eNOS phosphorylation in endothelial cells.


Author(s):  
Xianghua Yin ◽  
Yan Liu ◽  
Jiarui Qin ◽  
Yixuan Wu ◽  
Jiayan Huang ◽  
...  

Endometrial cancer (EC) is a common leading cause of cancer-related death in women, which is associated with the increased level of estrogen in the body. Artesunate (ART), an active compound derived from Artemisia annua L., exerted antitumor properties in several cancer types. However, the role of artesunate and the molecular basis on EC remains unclear. Here, we aimed to explore the effects and mechanisms of artesunate. Our results identified that estrogen receptor-α (ER-α) was a key factor for the type I EC (ER-α-positive), which might suppress the downstream LKB1/AMPK/mTOR pathway. Besides, we found ART significantly inhibited tumor proliferation in a dose-dependent manner. Mechanistic studies identified that ART led to tumor cell apoptosis and cell cycle arrest by downregulating the ER-α expression and activating the LKB1/AMPK/mTOR pathway. In addition, we found ART could increase the expression of heart and neural crest derivatives expressed 2 (HAND2) in the ER-α-positive EC cells, which could interact with ER-α. Through the gain-and loss-function experiments, we showed that over expression of HAND2 repressed the proliferation and migration of ER-α-positive EC cells via inhibition of ER-α expression. HAND2 knockdown increased ER-α expression and alleviated the antitumor effect of ART in vitro and in vivo. Overall, our study first showed that ART could be an effective antitumor agent through modulating ER-α-mediated LKB1/AMPK/mTOR pathway in the HAND2 dependent manner. Our findings provide an effective therapeutic agent for ER-α-positive EC treatment.


1997 ◽  
Vol 273 (1) ◽  
pp. H347-H355 ◽  
Author(s):  
H. L. Knudsen ◽  
J. A. Frangos

To study the role of the cytoskeleton in mechanochemical transduction, human umbilical vein endothelial cells were exposed to cytoskeleton-disrupting or -stabilizing agents, and the flow-induced production of nitric oxide (NO) as monitored by intracellular levels of guanosine 3',5'-cyclic monophosphate (cGMP) was examined. A shear stress of 20 dyn/cm2 elevated cGMP levels approximately twofold relative to basal (stationary) levels (1.9 +/- 0.1 pmol cGMP in stationary controls; P < 0.01). Treatment with 1 microM phalloidin and 0.5 microM cytochalasin D did not significantly affect the flow-induced response (1.77 +/- 0.23 and 2.89 +/- 0.18 pmol cGMP in stationary controls, respectively), whereas disruption of microtubules with 0.5 microM colchicine significantly elevated the response (3.64 +/- 0.18 pmol cGMP in stationary controls; P < 0.01). The NO synthase inhibitor NG-amino-L-arginine abrogated all flow-induced elevations of cGMP, indicating that increased cGMP levels were mediated by NO. Cytoskeletal disruption with 0.2 microM cytochalasin D or 0.5 microM colchicine did not alter cGMP levels in response to 10 nM bradykinin. The role of the plasma membrane in mechanochemical transduction was examined by treatment with cholesteryl hemisuccinate, which attenuated the flow-induced response in a dose-dependent manner. In conclusion, the pathways of flow- and bradykinin-mediated NO production in endothelial cells did not require actin filament turnover or intact actin or microtubule cytoskeletons, and cholesterol, possibly by stiffening the plasma membrane, attenuated the flow response.


Blood ◽  
1998 ◽  
Vol 92 (9) ◽  
pp. 3268-3276 ◽  
Author(s):  
Chia Hsin Yeh ◽  
Hui-Chin Peng ◽  
Tur-Fu Huang

Endothelial integrins play an essential role in angiogenesis and cell survival. Accutin, a new member of disintegrin family derived from venom of Agkistrodon acutus, potently inhibited human platelet aggregation caused by various agonists (eg, thrombin, collagen, and, adenosine diphosphate [ADP]) through the blockade of fibrinogen binding to platelet glycoprotein IIb/IIIa (ie, integrin IIbβ3). In this report, we describe that accutin specifically inhibited the binding of monoclonal antibody (MoAb) 7E3, which recognizes integrin vβ3, to human umbilical vein endothelial cells (HUVECs), but not those of other anti-integrin MoAbs such as 2β1, 3β1, and 5β1. Moreover, accutin, but not the control peptide GRGES, dose-dependently inhibited the 7E3 interaction with HUVECs. Both 7E3 and GRGDS, but not GRGES or Integrelin, significantly blocked fluorescein isothiocyanate-conjugated accutin binding to HUVEC. In functional studies, accutin exhibited inhibitory effects on HUVEC adhesion to immobilized fibrinogen, fibronectin and vitronectin, and the capillary-like tube formation on Matrigel in a dose- and RGD-dependent manner. In addition, it exhibited an effective antiangiogenic effect in vivo when assayed by using the 10-day-old embryo chick CAM model. Furthermore, it potently induced HUVEC apoptotic DNA fragmentation as examined by electrophoretic and flow cytometric assays. In conclusion, accutin inhibits angiogenesis in vivo and in vitro by blocking integrin vβ3 of endothelial cells and by inducing apoptosis. The antiangiogenic activity of disintegrins might be explored as the target of developing the potential antimetastatic agents.© 1998 by The American Society of Hematology.


2007 ◽  
Vol 85 (6) ◽  
pp. 709-720 ◽  
Author(s):  
Syamantak Majumder ◽  
K. P. Tamilarasan ◽  
Gopi Krishna Kolluru ◽  
Ajit Muley ◽  
C. Madhavan Nair ◽  
...  

Hepatic stellate cells are liver-specific pericytes and exist in close proximity with endothelial cells. The activation of liver pericytes is intrinsic to liver pathogenesis, and leads to endothelial dysfunction, including the low bioavailability of nitric oxide (NO). However, the role of nitric oxide in pericyte–endothelium cross-talk has not yet been elucidated. This work examines the cellular mechanism of action of NO in pericyte-mediated endothelial dysfunction. We used in vitro coculture and conditioned medium systems to study the effects of activated liver pericytes on endothelial function, and an egg yolk vascular bed model was used to study the effects of activated pericytes on angiogenesis. This study also demonstrates that activated pericytes attenuate the migration, proliferation, permeability, and NO production of endothelial cells. Our results demonstrate that activated pericytes restrict angiogenesis in egg yolk vascular bed models, and NO supplementation recovers 70% of the inhibition. Our results also demonstrate that supplementation with NO, sildenafil citrate (phosphodiesterase inhibitor), and 8-bromo-cGMP (cGMP analog) partially recovers activated-pericyte-mediated endothelium dysfunction. We conclude that NO–cGMP alleviates activated-pericyte-associated endothelial dysfunction, including angiogenesis, in a cGMP-dependent manner.


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