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.

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.

scholarly journals Atherosclerosis-Associated Endothelial Cell Apoptosis by MiR-429-Mediated Down Regulation of Bcl-2

2015 ◽  
Vol 37 (4) ◽  
pp. 1421-1430 ◽  
Author(s):  
Tao Zhang ◽  
Feng Tian ◽  
Jing Wang ◽  
Jing Jing ◽  
Shan-Shan Zhou ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Cell Apoptosis ◽  
Cell Injury ◽  
Luciferase Reporter ◽  
Lower Percentage ◽  
Endothelial Cell Apoptosis ◽  
Down Regulation ◽  
Bioinformatics Analyses

Background/Aims: Endothelial cell injury and subsequent apoptosis play a key role in the development and pathogenesis of atherosclerosis, which is hallmarked by dysregulated lipid homeostasis, aberrant immunity and inflammation, and plaque-instability-associated coronary occlusion. Nevertheless, our understanding of the mechanisms underlying endothelial cell apoptosis is still limited. MicroRNA-429 (miR-29) is a known cancer suppressor that promotes cancer cell apoptosis. However, it is unknown whether miR-429 may be involved in the development of atherosclerosis through similar mechanisms. We addressed these questions in the current study. Methods: We examined the levels of endothelial cell apoptosis in ApoE (-/-) mice suppled with high-fat diet (HFD), a mouse model for atherosclerosis (simplified as HFD mice). We analyzed the levels of anti-apoptotic protein Bcl-2 and the levels of miR-429 in the purified CD31+ endothelial cells from mouse aorta. Prediction of the binding between miR-429 and 3'-UTR of Bcl-2 mRNA was performed by bioinformatics analyses and confirmed by a dual luciferase reporter assay. The effects of miR-429 were further analyzed in an in vitro model using oxidized low-density lipoprotein (ox-LDL)-treated human aortic endothelial cells (HAECs). Results: HFD mice developed atherosclerosis in 12 weeks, while the control ApoE (-/-) mice that had received normal diet (simplified as NOR mice) did not. HFD mice had significantly lower percentage of endothelial cells and significantly higher percentage of mesenchymal cells in the aorta than NOR mice. Significantly higher levels of endothelial cell apoptosis were detected in HFD mice, resulting from decreases in Bcl-2 protein, but not mRNA. The decreases in Bcl-2 in endothelial cells were due to increased levels of miR-429, which suppressed the translation of Bcl-2 mRNA via 3'-UTR binding. These in vivo findings were reproduced in vitro on ox-LDL-treated HAECs. Conclusion: Atherosclerosis-associated endothelial cell apoptosis may result from down regulation of Bcl-2, through increased miR-429 that binds and suppresses translation of Bcl-2 mRNA.

scholarly journals Isoprenylcysteine Carboxyl Methyltransferase Activity Modulates Endothelial Cell Apoptosis

2003 ◽  
Vol 14 (3) ◽  
pp. 848-857 ◽  
Author(s):  
Kristina Kramer ◽  
Elizabeth O. Harrington ◽  
Qing Lu ◽  
Robert Bellas ◽  
Julie Newton ◽  
...  
Keyword(s):  
Endothelial Cell ◽  
Cell Apoptosis ◽  
Uv Light ◽  
Light Exposure ◽  
Small Gtpase ◽  
Endothelial Cell Apoptosis ◽  
Downstream Signaling ◽  
Carboxyl Methyltransferase ◽  
Endogenous Substrates ◽  
Induced Apoptosis

Extracellular ATP, adenosine (Ado), and adenosine plus homocysteine (Ado/HC) cause apoptosis of cultured pulmonary artery endothelial cells through the enhanced formation of intracellularS-adenosylhomocysteine and disruption of focal adhesion complexes. Because an increased intracellular ratio ofS-adenosylhomocysteine/S-adenosylmethionine favors inhibition of methylation, we hypothesized that Ado/HC might act by inhibition of isoprenylcysteine-O-carboxyl methyltransferase (ICMT). We found thatN-acetyl-S-geranylgeranyl-l-cysteine (AGGC) andN-acetyl-S-farnesyl-l-cysteine (AFC), which inhibit ICMT by competing with endogenous substrates for methylation, caused apoptosis. Transient overexpression of ICMT inhibited apoptosis caused by Ado/HC, UV light exposure, or tumor necrosis factor-α. Because the small GTPase, Ras, is a substrate for ICMT and may modulate apoptosis, we also hypothesized that inhibition of ICMT with Ado/HC or AGGC might cause endothelial apoptosis by altering Ras activation. We found that ICMT inhibition decreased Ras methylation and activity and the activation of the downstream signaling molecules Akt, ERK-1, and ERK-2. Furthermore, overexpression of wild-type or dominant active H-Ras blocked Ado/HC-induced apoptosis. These findings suggest that inhibition of ICMT causes endothelial cell apoptosis by attenuation of Ras GTPase methylation and activation and its downstream antiapoptotic signaling pathway.

scholarly journals MicroRNA-1185 Induces Endothelial Cell Apoptosis by Targeting UVRAG and KRIT1

2017 ◽  
Vol 41 (6) ◽  
pp. 2171-2182 ◽  
Author(s):  
Haoyuan Deng ◽  
Xia Chu ◽  
Zhenfeng Song ◽  
Xinrui Deng ◽  
Huan Xu ◽  
...  
Keyword(s):  
Endothelial Cell ◽  
Cell Apoptosis ◽  
Cell Injury ◽  
Luciferase Reporter ◽  
Endothelial Cell Apoptosis ◽  
Endothelial Apoptosis ◽  
Mechanistic Analysis ◽  
Interfering Rna ◽  
The Impact

Background/Aims: Atherosclerosis is a multifactorial chronic disease and is the main cause of death and impairment in the world. Endothelial injury and apoptosis play a crucial role in the onset and development of atherosclerosis. MicroRNAs (miRNAs) have been proven to be involved in the pathogenesis of atherosclerosis. However, studies of the functional role of apoptosis-related miRNAs in the endothelium during atherogenesis are limited. Methods: Cell injury and apoptosis were measured in five types of cells transfected with miR-1185 or co-transfected with miR-1185 and its inhibitor. Bioinformatics analysis and a luciferase reporter assay were used to confirm the targets of miR-1185. The effects of the targets of miR-1185 on endothelial apoptosis were determined using small-interfering RNA. Results: In this study, we first report that miR-1185 significantly promoted apoptosis in endothelial cells but not in vascular smooth muscle cells and macrophages. A mechanistic analysis showed that ultraviolet irradiation resistance-associated gene (UVRAG) and krev1 interaction trapped gene 1 (KRIT1), targets of miR-1185, mediated miR-1185-induced endothelial cell apoptosis. Conclusion: The results revealed the impact of miR-1185 on endothelial apoptosis, suggesting that miR-1185 may be a potential target for the prevention and treatment of atherosclerosis.

scholarly journals Glutathione in Cerebral Microvascular Endothelial Biology and Pathobiology: Implications for Brain Homeostasis

2012 ◽  
Vol 2012 ◽  
pp. 1-14 ◽  
Author(s):  
Wei Li ◽  
Carmina Busu ◽  
Magdalena L. Circu ◽  
Tak Yee Aw
Keyword(s):  
Cell Proliferation ◽  
Endothelial Cell ◽  
Cell Fate ◽  
Mammalian Cells ◽  
Redox Regulation ◽  
Cell Injury ◽  
Control Cell ◽  
Endothelial Cell Proliferation ◽  
Special Focus ◽  
Vascular Integrity

The integrity of the vascular endothelium of the blood-brain barrier (BBB) is central to cerebrovascular homeostasis. Given the function of the BBB as a physical and metabolic barrier that buffers the systemic environment, oxidative damage to the endothelial monolayer will have significant deleterious impact on the metabolic, immunological, and neurological functions of the brain. Glutathione (GSH) is a ubiquitous major thiol within mammalian cells that plays important roles in antioxidant defense, oxidation-reduction reactions in metabolic pathways, and redox signaling. The existence of distinct GSH pools within the subcellular organelles supports an elegant mode for independent redox regulation of metabolic processes, including those that control cell fate. GSH-dependent homeostatic control of neurovascular function is relatively unexplored. Significantly, GSH regulation of two aspects of endothelial function is paramount to barrier preservation, namely, GSH protection against oxidative endothelial cell injury and GSH control of postdamage cell proliferation in endothelial repair and/or wound healing. This paper highlights our current insights and hypotheses into the role of GSH in cerebral microvascular biology and pathobiology with special focus on endothelial GSH and vascular integrity, oxidative disruption of endothelial barrier function, GSH regulation of endothelial cell proliferation, and the pathological implications of GSH disruption in oxidative stress-associated neurovascular disorders, such as diabetes and stroke.

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.

Extracellular ATP and ADP Activate Transcription Factor NF-κB and Induce Endothelial Cell Apoptosis

1998 ◽  
Vol 248 (3) ◽  
pp. 822-829 ◽  
Author(s):  
Michaela von Albertini ◽  
Alois Palmetshofer ◽  
Elzbieta Kaczmarek ◽  
Katarzyna Koziak ◽  
Deborah Stroka ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Endothelial Cell ◽  
Cell Apoptosis ◽  
Extracellular Atp ◽  
Endothelial Cell Apoptosis ◽  
Activate Transcription Factor

Hyperoxia induces retinal vascular endothelial cell apoptosis through formation of peroxynitrite

2003 ◽  
Vol 285 (3) ◽  
pp. C546-C554 ◽  
Author(s):  
Xiaolin Gu ◽  
Azza B. El-Remessy ◽  
Steven E. Brooks ◽  
Mohamed Al-Shabrawey ◽  
Nai-Tsi Tsai ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Endothelial Cell ◽  
Cell Apoptosis ◽  
Vascular Endothelial Cell ◽  
In Vivo Studies ◽  
Endothelial Cell Apoptosis ◽  
Akt Kinase ◽  
Induced Apoptosis

Hyperoxia exposure induces capillary endothelial cell apoptosis in the developing retina, leading to vaso-obliteration followed by proliferative retinopathy. Previous in vivo studies have shown that endothelial nitric oxide synthase (NOS3) and peroxynitrite are important mediators of the vaso-obliteration. Now we have investigated the relationship between hyperoxia, NOS3, peroxynitrite, and endothelial cell apoptosis by in vitro experiments using bovine retinal endothelial cells (BREC). We found that BREC exposed to 40% oxygen (hyperoxia) for 48 h underwent apoptosis associated with activation of caspase-3 and cleavage of the caspase substrate poly(ADP-ribose) polymerase. Hyperoxia-induced apoptosis was associated with increased formation of nitric oxide, peroxynitrite, and superoxide anion and was blocked by treatment with uric acid, nitro-l-arginine methyl ester, or superoxide dismutase. Analyses of the phosphatidylinositol 3-kinase/Akt kinase survival pathway in cells directly treated with peroxynitrite revealed inhibition of VEGF- and basic FGF-induced activation of Akt kinase. These results suggest that hyperoxia-induced formation of peroxynitrite induces BREC apoptosis by crippling key survival pathways and that blocking peroxynitrite formation prevents apoptosis. These data may have important clinical implications for infants at risk of retinopathy of prematurity.

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