Expression of human endothelin-converting enzyme isoforms: role of angiotensin IIThis article is one of a selection of papers published in the special issue (part 1 of 2) on Forefronts in Endothelin.

2008 ◽  
Vol 86 (6) ◽  
pp. 299-309 ◽  
Author(s):  
W. Goettsch ◽  
A. Schubert ◽  
H. Morawietz
Keyword(s):  
Endothelial Cells ◽  
Mrna Expression ◽  
Umbilical Vein ◽  
Artery Bypass ◽  
Control Group ◽  
Ang Ii ◽  
Converting Enzyme ◽  
Mammary Arteries ◽  
Endothelin Converting Enzyme ◽  
Internal Mammary

A key step in endothelin-1 (ET-1) synthesis is the proteolytic cleavage of big ET-1 by the endothelin-converting enzyme-1 (ECE-1). Four alternatively spliced isoforms, ECE-1a to ECE-1d, have been discovered; however, regulation of the expression of specific ECE-1 isoforms is not well understood. Therefore, we stimulated primary human umbilical vein endothelial cells (HUVECs) with angiotensin II (Ang II). Furthermore, expression of ECE-1 isoforms was determined in internal mammary arteries of patients undergoing coronary artery bypass grafting surgery. Patients had received one of 4 therapies: angiotensin-converting enzyme inhibitors (ACE-I), Ang II type 1 receptor blockers (ARB), HMG-CoA reductase inhibitors (statins), and a control group that had received neither ACE-I, ARB (that is, treatment not interfering in the renin–angiotensin system), nor statins. Under control conditions, ECE-1a is the dominant isoform in HUVECs (4.5 ± 2.8 amol/μg RNA), followed by ECE-1c (2.7 ± 1.0 amol/μg), ECE-1d (0.49 ± 0.17 amol/μg), and ECE-1b (0.17 ± 0.04 amol/μg). Stimulation with Ang II did not change the ECE-1 expression pattern or the ET-1 release. We found that ECE-1 mRNA expression was higher in patients treated with statins than in patients treated with ARB therapy (5.8 ± 0.76 RU versus 3.0 ± 0.4 RU), mainly attributed to ECE-1a. In addition, ECE-1a mRNA expression was higher in patients receiving ACE-I therapy than in patients receiving ARB therapy (1.68 ± 0.27 RU versus 0.83 ± 0.07 RU). We conclude that ECE-1a is the major ECE-1 isoform in primary human endothelial cells. Its expression in internal mammary arteries can be regulated by statin therapy and differs between patients with ACE-I and ARB therapy.

scholarly journals The expression of Drosha, DGCR8, Dicer and Ago-2 genes are upregulated in human umbilical vein endothelial cells under hyperglycemic condition

2018 ◽  
Vol 52 (3) ◽  
pp. 123-127 ◽  
Author(s):  
Farhad Ghadiri Soufi ◽  
Ali Akbar Poursadegh Zonouzi ◽  
Ebrahim Eftekhar ◽  
Kamila Kamali ◽  
Sara Aghakhani Chegeni ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Mrna Expression ◽  
Umbilical Vein ◽  
Control Group ◽  
Human Umbilical Vein ◽  
Expression Levels ◽  
Expression Of Genes ◽  
Mirnas Expression ◽  
Umbilical Vein Endothelial Cells ◽  
Mrna Expression Levels

AbstractObjectives. It has been shown that dysregulation of miRNAs expression contributes to the pathogenesis and progression of the diabetes and diabetes-related complications. Drosha, DGCR8, Dicer, and Ago-2 are involved in the miRNA maturation. The aim of the present study was to investigate the mRNA expression levels of these genes in the human umbilical vein endothelial cells (HUVECs) under hyperglycemic condition.Methods. HUVECs were cultured in normo-(5 mM) and hyperglycemic (25 mM) conditions for 24 h. As osmotic control, cells were treated with D-mannitol (25 mM, for 24 h). The mRNA expression levels of Drosha, DGCR8, Dicer and Ago-2 were evaluated using quantitative real-time PCR.Results. The expression level of Drosha, DGCR8, Dicer, and Ago-2 were increased in hyperglycemic HUVECs compared to the control group.Conclusion. Our results show that under hyperglycemic condition, expression of genes involved in the miRNA maturation was significantly increased in HUVECs. Upregulation of these genes may have role in diabetic complications through the dysregulation of the miRNA expression.

Abstract 259: Sam68 Regulates Endothelin-Converting Enzyme-1b Expression and Blood Pressure Homeostasis

Hypertension ◽  
2012 ◽  
Vol 60 (suppl_1) ◽  
Author(s):  
Junlan Zhou ◽  
Gangjian Qin
Keyword(s):  
Blood Pressure ◽  
Cell Cycle ◽  
Endothelial Cells ◽  
Molecular Mechanisms ◽  
Rna Binding ◽  
Umbilical Vein ◽  
Converting Enzyme ◽  
Proteomic Approach ◽  
Endothelin Converting Enzyme

We have previously reported that E2F2, a transcription factor known for its role in cell cycle, regulates the expression of endothelin-converting enzyme-1b (ECE-1b) in endothelial cells and contributes to the maintenance of vascular contractility and blood pressure (BP). However, the molecular mechanisms underlying this novel, cell-cycle independent function of E2F2 remain largely elusive. In this study, we profiled E2F2 interactome in the nucleus of human umbilical vein endothelial cells by utilizing a proteomic approach. We identified that Sam68, a classic RNA-binding protein and Src kinase substrate, acts as an E2F2-interacting protein; co-immunoprecipitation analyses confirmed that both endogenous and ectopically-expressed Sam68 interact with E2F2. Overexpression of Sam68 repressed whereas knockdown of Sam68 increased E2F2-induced ECE-1b promoter activity and mRNA expression. Chromatin immunoprecipitation assays further confirmed that E2F2 and Sam68 co-localize on ECE-1b promoter, indicating that ECE-1b is a direct transcriptional target of E2F2 and Sam68. In vivo, Sam68 knockout (KO) mice displayed a significantly lowered BP as compared to WT littermates (tail-cuff measurements of mean BP, KO vs. WT: 104 ± 6 vs. 123 ± 7 mmHg, n=25 males of age 4-6 months, P<0.05). Together, our studies have revealed a previously unknown function of Sam68 as a transcriptional co-repressor of E2F2 and a critical regulator of BP homeostasis.

Abstract 261: Endothelial Cells Contribute to RAS Activation in Microvascular Smooth Muscle Cells

2012 ◽  
Vol 111 (suppl_1) ◽  
Author(s):  
Kayoko Miyata ◽  
Ryousuke Satou ◽  
L Gabriel Navar
Keyword(s):  
Endothelial Cells ◽  
Smooth Muscle ◽  
Mrna Expression ◽  
Culture Medium ◽  
Primary Cultures ◽  
Mrna Levels ◽  
Ang Ii ◽  
Relative Ratio ◽  
Renin Mrna ◽  
Afferent Arterioles

Introduction: We have demonstrated that Ang II augments angiotensinogen (AGT) expression in rat preglomerular vascular smooth muscle cells (VSMCs). However, it is unclear if endothelial cells (ECs) are involved in augmentation of AGT in renal afferent arterioles. Hypothesis: We assessed the hypothesis that the ECs respond to paracrine signals that Ang II contribute to AGT augmentation in VSMCs. Objective: We established primary cultures of preglomerular ECs and examined the effects of Ang II and/or culture medium from ECs on AGT expression in preglomerular VSMCs. Methods and Results: We established primary cultures of preglomerular ECs, isolated from afferent arterioles of Sprague-Dawley rats. The cells were identified as ECs by being positive for a marker, CD34 and endothelial NOS and negative for alpha-SMA (a marker for VSMCs) and P4H-b (a marker for Fibroblasts) by immnostaining. The expression levels of AGT mRNA and renin mRNA in preglomerular ECs were examined by real-time RT-PCR. Ang II (100 pmol/L) increased AGT mRNA levels (1.34 +/- 0.16, by 100 pmol/L, N=4) and Renin mRNA levels (6.16 +/- 0.96, by 100 nmol/L, N=4) in ECs. On the other hand, the same dose of Ang II suppressed Renin mRNA expression in isolated Juxtaglomerular cells (JGs). These results indicate that preglomerular ECs are respond to Ang II and exclude the possible contamination of JGs into ECs. 100 pmol/L of Ang II increased AGT mRNA expression levels (1.37 +/- 0.03, relative ratio, N=4) in preglomerular VSMCs and the culture medium of ECs without Ang II treatment also more increased AGT mRNA expression (1.62 +/- 0.13, relative ratio, N=4) in preglomerular VSMCs. The AGT mRNA expression augmentation was enhanced when preglomerular VSMCs were treated with culture medium of Ang II-treated preglomerular ECs (2.39 +/- 0.41, relative ratio, N=4). The synergistic effects of Ang II and preglomerular ECs were also observed in PAI-1 expression in preglomerular VSMCs. Conclusion: These data demonstrate that preglomerular ECs contribute to Ang II-upregulation of AGT in renal afferent arterioles leading to further Ang II augmentation, which leads to increases in inflammatory and sclerotic factors in preglomerular VSMCs.

scholarly journals Alpha-Asarone Protects Endothelial Cells from Injury by Angiotensin II

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Hai-Xia Shi ◽  
Jiajun Yang ◽  
Tao Yang ◽  
Yong-Liang Xue ◽  
Jun Liu ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Endothelial Cells ◽  
Angiotensin Ii ◽  
Cell Injury ◽  
Fluorescent Dyes ◽  
Umbilical Vein ◽  
Protective Effects ◽  
Ang Ii ◽  
Versus Model

α-Asarone is the major therapeutical constituent ofAcorus tatarinowiiSchott. In this study, the potential protective effects ofα-asarone against endothelial cell injury induced by angiotensin II were investigatedin vitro. The EA.hy926 cell line derived from human umbilical vein endothelial cells was pretreated withα-asarone (10, 50, 100 µmol/L) for 1 h, followed by coincubation with Ang II (0.1 µmol/L) for 24 h. Intracellular nitric oxide (NO) and reactive oxygen species (ROS) were detected by fluorescent dyes, and phosphorylation of endothelial nitric oxide synthase (eNOS) atSer1177was determined by Western blotting.α-Asarone dose-dependently mitigated the Ang II-induced intracellular NO reduction (P<0.01versus model) and ROS production (P<0.01versus model). Furthermore, eNOS phosphorylation (Ser1177) by acetylcholine was significantly inhibited by Ang II, while pretreatment for 1 h withα-asarone partially prevented this effect (P<0.05versus model). Additionally, cell viability determined by the MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay (105~114.5% versus control,P>0.05) was not affected after 24 h of incubation withα-asarone at 1–100 µmol/L. Therefore,α-asarone protects against Ang II-mediated damage of endothelial cells and may be developed to prevent injury to cardiovascular tissues.

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