25-Hydroxycholesterol impairs endothelial function and vasodilation by uncoupling and inhibiting endothelial nitric oxide synthase

2016 ◽  
Vol 311 (4) ◽  
pp. E781-E790 ◽  
Author(s):  
Zhi-Jun Ou ◽  
Jing Chen ◽  
Wei-Ping Dai ◽  
Xiang Liu ◽  
Yin-Ke Yang ◽  
...  
Keyword(s):  
Endothelial Cell ◽  
Endothelial Function ◽  
Cell Apoptosis ◽  
Caspase 3 ◽  
Immunoblot Analysis ◽  
Tube Formation ◽  
Endothelial Cell Proliferation ◽  
No Production ◽  
Endothelial Cell Apoptosis ◽  
Caspase 9

Endothelial dysfunction is a key early step in atherosclerosis. 25-Hydroxycholesterol (25-OHC) is found in atherosclerotic lesions. However, whether 25-OHC promotes atherosclerosis is unclear. Here, we hypothesized that 25-OHC, a proinflammatory lipid, can impair endothelial function, which may play an important role in atherosclerosis. Bovine aortic endothelial cells were incubated with 25-OHC. Endothelial cell proliferation, migration, and tube formation were measured. Nitric oxide (NO) production and superoxide anion generation were determined. The expression and phosphorylation of endothelial NO synthase (eNOS) and Akt as well as the association of eNOS and heat shock protein (HSP)90 were detected by immunoblot analysis and immunoprecipitation. Endothelial cell apoptosis was monitored by TUNEL staining and caspase-3 activity, and expression of Bcl-2, Bax, cleaved caspase-9, and cleaved caspase-3 were detected by immunoblot analysis. Finally, aortic rings from Sprague-Dawley rats were isolated and treated with 25-OHC, and endothelium-dependent vasodilation was evaluated. 25-OHC significantly inhibited endothelial cell proliferation, migration, and tube formation. 25-OHC markedly decreased NO production and increased superoxide anion generation. 25-OHC reduced the phosphorylation of Akt and eNOS and the association of eNOS and HSP90. 25-OHC also enhanced endothelial cell apoptosis by decreasing Bcl-2 expression and increasing cleaved caspase-9 and cleaved caspase-3 expressions as well as caspase-3 activity. 25-OHC impaired endothelium-dependent vasodilation. These data demonstrated that 25-OHC could impair endothelial function by uncoupling and inhibiting eNOS activity as well as by inducing endothelial cell apoptosis. Our findings indicate that 25-OHC may play an important role in regulating atherosclerosis.

The interferon-inducible gene IFI16, a member of the HIN200 family, triggers primary endothelial cell apoptosis through caspase 2 and caspase 3 pathway

Cytokine ◽  
2009 ◽  
Vol 48 (1-2) ◽  
pp. 85
Author(s):  
Francesca Gugliesi ◽  
Marco De Andrea ◽  
Michele Mondini ◽  
Paola Cappello ◽  
Mirella Giovarelli ◽  
...  
Keyword(s):  
Endothelial Cell ◽  
Cell Apoptosis ◽  
Caspase 3 ◽  
Endothelial Cell Apoptosis ◽  
Caspase 2 ◽  
Inducible Gene

scholarly journals Downregulation of Endogenous Hydrogen Sulfide Pathway Is Involved in Mitochondrion-Related Endothelial Cell Apoptosis Induced by High Salt

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Yanfang Zong ◽  
Yaqian Huang ◽  
Siyao Chen ◽  
Mingzhu Zhu ◽  
Qinghua Chen ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Endothelial Cells ◽  
Membrane Potential ◽  
Endothelial Cell ◽  
Cell Apoptosis ◽  
Superoxide Anion ◽  
Mitochondrial Membrane ◽  
Caspase 3 ◽  
High Salt ◽  
Caspase 9

Background. The study aimed to investigate whether endogenous H2S pathway was involved in high-salt-stimulated mitochondria-related vascular endothelial cell (VEC) apoptosis.Methods. Cultured human umbilical vein endothelial cells (HUVECs) were used in the study. H2S content in the supernatant was detected. Western blot was used to detect expression of cystathionine gamma-lyase (CSE), cleaved-caspase-3, and mitochondrial and cytosolic cytochrome c (cytc). Fluorescent probes were used to quantitatively detect superoxide anion generation and measure thein situsuperoxide anion generation in HUVEC. Mitochondrial membrane pore opening, mitochondrial membrane potential, and caspase-9 activities were measured. The cell apoptosis was detected by cell death ELISA and TdT-mediated dUTP nick end labeling (TUNEL) methods.Results. High-salt treatment downregulated the endogenous VEC H2S/CSE pathway, in association with increased generation of oxygen free radicals, decreased mitochondrial membrane potential, enhanced the opening of mitochondrial membrane permeability transition pore and leakage of mitochondrial cytc, activated cytoplasmic caspase-9 and caspase-3 and subsequently induced VEC apoptosis. However, supplementation of H2S donor markedly inhibited VEC oxidative stress and mitochondria-related VEC apoptosis induced by high salt.Conclusion. H2S/CSE pathway is an important endogenous defensive system in endothelial cells antagonizing high-salt insult. The protective mechanisms for VEC damage might involve inhibiting oxidative stress and protecting mitochondrial injury.

Mechanism of extracellular ATP- and adenosine-induced apoptosis of cultured pulmonary artery endothelial cells

1998 ◽  
Vol 275 (2) ◽  
pp. L379-L388 ◽  
Author(s):  
Sharon Rounds ◽  
Winnie Lin Yee ◽  
Doloretta D. Dawicki ◽  
Elizabeth Harrington ◽  
Nancy Parks ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Endothelial Cell ◽  
Adenosine Deaminase ◽  
Cell Apoptosis ◽  
Cell Injury ◽  
Extracellular Atp ◽  
Endothelial Cell Proliferation ◽  
Endothelial Cell Apoptosis ◽  
Intracellular Acidosis ◽  
Induced Apoptosis

Apoptosis may be important in the exacerbation of endothelial cell injury or limitation of endothelial cell proliferation. We have found that extracellular ATP (exATP) and adenosine cause endothelial apoptosis and that the development of apoptosis is linked to intracellular metabolism of adenosine [Dawicki, D. D., D. Chatterjee, J. Wyche, and S. Rounds. Am. J. Physiol. 273 ( Lung Cell Mol. Physiol. 17): L485–L494, 1997]. In the present study, we investigated the mechanism of this effect. We found that exATP, adenosine, and the S-adenosyl-l-homocysteine (SAH) hydrolase inhibitor MDL-28842 caused apoptosis and decreased the ratio of S-adenosyl-l-methionine to SAH compared with untreated control cells. Using release of soluble [3H]thymidine as a measure of DNA fragmentation, we found that the effect of adenosine on soluble DNA release was potentiated by coincubation with homocysteine. These results suggest that the mechanism of exATP- and adenosine-induced endothelial cell apoptosis involves inhibition of SAH hydrolase. exATP-induced apoptosis was enhanced by an inhibitor of adenosine deaminase, whereas exogenous adenosine-induced apoptosis was partially inhibited by an adenosine deaminase inhibitor. These results suggest that adenosine deaminase may also be involved in the mechanism of adenosine-induced endothelial cell apoptosis. Adenosine and MDL-28842 caused intracellular acidosis as assessed with the fluorescent probe 2′,7′-bis(2-carboxyethyl)-5(6)-carboxyfluorescein. The cell-permeant base chloroquine prevented adenosine-induced acidosis but not apoptosis. Thus, although intracellular acidosis is associated with adenosine-induced apoptosis, it is not necessary for this effect. We speculate that exATP- and adenosine-induced endothelial cell apoptosis may be due to an inhibition of methyltransferase(s) activity. Purine-induced endothelial cell apoptosis may be important in limiting endothelial cell proliferation after vascular injury.

Simvastatin causes endothelial cell apoptosis and attenuates severe pulmonary hypertension

2006 ◽  
Vol 291 (4) ◽  
pp. L668-L676 ◽  
Author(s):  
Laimute Taraseviciene-Stewart ◽  
Robertas Scerbavicius ◽  
Kang-Hyeon Choe ◽  
Carlyne Cool ◽  
Kathy Wood ◽  
...  
Keyword(s):  
Pulmonary Hypertension ◽  
Endothelial Cell ◽  
Right Ventricular ◽  
Cell Apoptosis ◽  
Ventricular Hypertrophy ◽  
Caspase 3 ◽  
Right Ventricular Hypertrophy ◽  
Severe Pulmonary Hypertension ◽  
Endothelial Cell Apoptosis ◽  
Microvascular Endothelial

Severe pulmonary hypertension (SPH) is characterized by precapillary arteriolar lumen obliteration, dramatic right ventricular hypertrophy, and pericardial effusion. Our recently published rat model of SPH recapitulates major components of the human disease. We used this model to develop new treatment strategies for SPH. SPH in rats was induced using VEGF receptor blockade in combination with chronic hypoxia. A large variety of drugs used in this study, including anticancer drugs (cyclophosphamide and paclitaxel), the angiotensin-converting enzyme inhibitor lisinopril, the antiangiogenic agent thalidomide, and the peroxisome proliferator-actived receptor-γ agonist PGJ2, failed to decrease mean pulmonary artery pressure (PAP) or right ventricular hypertrophy. In contrast, treatment of rats with established SPH with simvastatin markedly reduced mean PAP and right ventricular hypertrophy, and this reduction was associated with caspase-3 activation and pulmonary microvascular endothelial cell apoptosis. Simvastatin partially restored caveolin-1, caveolin-2, and phospho-caveolin expression in vessel walls. In rat primary pulmonary microvascular endothelial cells, simvastatin induced caspase 3 activation and Rac 1 expression while suppressing Rho A and attenuated levels of Akt and ERK phosphorylation. We conclude that simvastatin is effective in inducing apoptosis in hyperproliferative pulmonary vascular lesions and could be considered as a potential drug for treatment of human SPH.

scholarly journals The Src family tyrosine kinases src and yes have differential effects on inflammation-induced apoptosis in human pulmonary microvascular endothelial cells

2016 ◽  
Vol 310 (9) ◽  
pp. L880-L888 ◽  
Author(s):  
Leif D. Nelin ◽  
Hilary A. White ◽  
Yi Jin ◽  
Jennifer K. Trittmann ◽  
Bernadette Chen ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Cell Apoptosis ◽  
Caspase 3 ◽  
Microvascular Endothelial Cells ◽  
Erk Pathway ◽  
Endothelial Cell Apoptosis ◽  
Phosphatidylinositol 3 Kinase ◽  
Erk Activation ◽  
Differential Effects

Endothelial cells are essential for normal lung function: they sense and respond to circulating factors and hemodynamic alterations. In inflammatory lung diseases such as acute respiratory distress syndrome, endothelial cell apoptosis is an inciting event in pathogenesis and a prominent pathological feature. Endothelial cell apoptosis is mediated by circulating inflammatory factors, which bind to receptors on the cell surface, activating signal transduction pathways, leading to caspase-3-mediated apoptosis. We hypothesized that yes and src have differential effects on caspase-3 activation in human pulmonary microvascular endothelial cells (hPMVEC) due to differential downstream signaling effects. To test this hypothesis, hPMVEC were treated with siRNA against src (siRNAsrc), siRNA against yes (siRNAyes), or their respective scramble controls. After recovery, the hPMVEC were treated with cytomix (LPS, IL-1β, TNF-α, and IFN-γ). Treatment with cytomix induced activation of the extracellular signal-regulated kinase (ERK) pathway and caspase-3-mediated apoptosis. Treatment with siRNAsrc blunted cytomix-induced ERK activation and enhanced cleaved caspase-3 levels, while treatment with siRNAyes enhanced cytomix-induced ERK activation and attenuated levels of cleaved caspase-3. Inhibition of the ERK pathway using U0126 enhanced cytomix-induced caspase-3 activity. Treatment of hPMVEC with cytomix induced Akt activation, which was inhibited by siRNAsrc. Inhibition of the phosphatidylinositol 3-kinase/Akt pathway using LY294002 prevented cytomix-induced ERK activation and augmented cytomix-induced caspase-3 cleavage. Together, our data demonstrate that, in hPMVEC, yes activation blunts the ERK cascade in response to cytomix, resulting in greater apoptosis, while cytomix-induced src activation induces the phosphatidylinositol 3-kinase pathway, which leads to activation of Akt and ERK and attenuation of apoptosis.

scholarly journals Homophilic PECAM-1(CD31) interactions prevent endothelial cell apoptosis but do not support cell spreading or migration

1999 ◽  
Vol 112 (12) ◽  
pp. 1989-1997 ◽  
Author(s):  
I.N. Bird ◽  
V. Taylor ◽  
J.P. Newton ◽  
J.H. Spragg ◽  
D.L. Simmons ◽  
...  
Keyword(s):  
Cell Adhesion ◽  
Endothelial Cell ◽  
Cell Apoptosis ◽  
Cell Spreading ◽  
Tube Formation ◽  
Surface Glycoprotein ◽  
Endothelial Cell Apoptosis ◽  
Cell Surface Glycoprotein ◽  
Support Cell ◽  
Induced Apoptosis

PECAM-1 (CD31) is a highly abundant cell surface glycoprotein expressed on haemopoietic and endothelial cells. As well as mediating homophilic (PECAM-1/PECAM-1) adhesion, PECAM-1 can also bind the integrin alphavbeta3. Both PECAM-1 and alphavbeta3 have been shown to have roles in regulating angiogenesis, endothelial tube formation and in the case of alphavbeta3, endothelial cell apoptosis. In this study we show that despite being expressed at equivalent levels, endothelial alphavbeta3 is not a ligand for PECAM-1. Rather, PECAM-1 supports homophilic binding on HUVEC with similar characteristics to those we have previously reported for leukocytes and becomes tyrosine phosphorylated after homophilic PECAM-1 and integrin/fibronectin engagement. Immunoprecipitation studies show that in addition to SHP-2, tyrosine phosphorylated PECAM-1 can interact with at least four other phosphoproteins in pervanadate stimulated HUVEC. While PECAM-1/PECAM-1 interactions support robust endothelial cell adhesion, they do not support cell spreading or migration. In addition PECAM-1 homophilic adhesion rescues HUVEC from serum deprivation-induced apoptosis. Taken together our results indicate that PECAM-1 homophilic interactions play an important role in interendothelial cell adhesion, survival and signalling.

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