Coordinate regulation of endothelin and adrenomedullin secretion by oxidative stress in endothelial cells

2001 ◽  
Vol 281 (3) ◽  
pp. H1364-H1371 ◽  
Author(s):  
Takatoshi Saito ◽  
Hiroshi Itoh ◽  
Tae-Hwa Chun ◽  
Yasutomo Fukunaga ◽  
Jun Yamashita ◽  
...  

To elucidate the significance of oxidative stress in the modulation of endothelial functions, we examined the effects of H2O2 on the expression of two endothelium-derived vasoactive peptides, endothelin (ET) and adrenomedullin (Am), and their interaction. H2O2 dose dependently suppressed ET secretion and ET-1 mRNA expression in bovine carotid endothelial cells (ECs). Menadion sodium bisulfate, a redox cycling drug, also decreased ET secretion in a dose-dependent manner. Catalase, a H2O2 reductase, and dl-α-tocopherol (vitamin E) significantly inhibited H2O2-induced suppression of ET secretion. Downregulation of ET-1 mRNA under oxidative stress was regulated at the transcriptional level. In contrast, H2O2increased Am secretion (and its mRNA expression) accompanied by the augmentation of cAMP production. Am, as well as 8-bromo-cAMP and forskolin decreased ET secretion in a dose-dependent fashion. Furthermore, an anti-Am monoclonal antibody that we developed abolished H2O2-induced suppression of ET secretion at 6–24 h after the addition of H2O2. H2O2 increased the intracellular Ca2+ concentration ([Ca2+]i). Moreover, treatment with ionomycin, a Ca2+ ionophore, and thapsigargin, an inhibitor of endoplasmic reticulum ATPase, decreased ET secretion dose dependently for 3 h. These results suggest that the production of ET was decreased via activation of the Am-cAMP pathway and by the elevation of [Ca2+]i under oxidative stress. These findings elucidate the coordinate expression of two local vascular hormones, ET and Am, under oxidative stress, which may protect against vascular diseases.

2001 ◽  
Vol 281 (3) ◽  
pp. C899-C907 ◽  
Author(s):  
Margarita D. Apostolova ◽  
Shali Chen ◽  
Subrata Chakrabarti ◽  
M. George Cherian

Vascular endothelial cells are constantly exposed to oxidative stress and must be protected by physiological responses. In diabetes mellitus, endothelial cell permeability is impaired and may be increased by high extracellular glucose concentrations. It has been postulated that metallothionein (MT) can protect endothelial cells from oxidative stress with its increased expression by cytokines, thrombin, and endothelin (ET)-1. In this study, we demonstrate that high glucose concentration can induce MT expression in endothelial cells through a distinct ET-dependent pathway. Exposure of human umbilical vein endothelial cells (HUVEC) to increasing concentrations of glucose resulted in a rapid dose-dependent increase in MT-2 and ET-1 mRNA expression. MT expression may be further augmented with addition of ET-1. Preincubation of the cells with the specific ETB antagonist BQ-788 blocked MT-2 mRNA expression more effectively than the ETA inhibitor TBC-11251. High glucose also increased immunoreactive MT protein expression and induced translocation of MT into the perinuclear area. Perinuclear localization of MT was related to high-glucose-induced reorganization of F-actin filaments. These results demonstrate that an increase in extracellular glucose in HUVEC can lead to a rapid dose-dependent increase in MT-2 mRNA expression and to perinuclear localization of MT protein with changes to the cytoskeleton. These effects are mediated via the ET receptor-dependent pathway.


2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Alejandro Cuevas ◽  
Nicolás Saavedra ◽  
Martina Rudnicki ◽  
Dulcineia S. P. Abdalla ◽  
Luis A. Salazar

Propolis has been shown to modulate the angiogenesis in bothin vitroandin vivomodels. Thus, we aimed to evaluate the antiangiogenic properties of an ethanolic extract of Chilean propolis (EEP) and Pinocembrin (Pn). Migration, formation of capillary-like structures of endothelial cells, and sprouting from rat aortic rings were used to assess the antiangiogenic properties of EEP or Pn. In addition, microRNAs and VEGFA mRNA expression were studied by qPCR. ERK1/2 phosphorylation and HIF1αstabilization were assessed by western blot. EEP or Pn attenuated the migration, the capillary-like tube formation, and the sprouting in thein vitroassays. In addition, the activation of HIF1αand ERK1/2 and the VEGFA mRNA expression was significantly inhibited in a dose-dependent manner. In summary, these results suggest that HIF1αand ERK1/2 phosphorylation could be involved in the antiangiogenic effect of Chilean propolis, but more studies are needed to corroborate these findings.


2003 ◽  
Vol 88 (2) ◽  
pp. 663-672 ◽  
Author(s):  
Shahram Khosravi ◽  
Peter C. K. Leung

In humans, reproduction was generally believed to be controlled by only one form of GnRH (called mammalian GnRH or GnRHI). However, recently, a second form of GnRH, analogous to chicken GnRHII, was discovered in several tissues, including the human ovary. The regulation and function of GnRHI in the hypothalamus has been well studied. However, the function and regulation of GnRHI, and particularly GnRHII in the ovary, is less well understood. Because gonadal sex steroids are one of the main regulators of reproduction, we investigated, in the present study, the regulation of GnRHI and GnRHII mRNA expression by 17β-estradiol (E2) and RU486 (a progesterone antagonist) in human granulosa luteal cells (hGLCs). The levels of the mRNA transcripts encoding the two GnRH forms were examined using semiquantitative RT-PCR followed by Southern blot analysis. With time in culture, GnRHI and GnRHII mRNA levels significantly increased, by 120% and 210%, at d 8 and d 1, respectively. The levels remained elevated until the termination of these experiments at d 10. A 24-h treatment of hGLCs with E2 (10−9 to 10−7m) resulted in a dose-dependent decrease and increase in mRNA expression of GnRHI and GnRHII, respectively. E2 (10−9m) significantly decreased GnRHI mRNA levels (by 55%) and increased GnRHII mRNA levels (by 294%). Time-course studies demonstrated that E2 (10−9m) significantly decreased GnRHI mRNA levels in a time-dependent manner, with maximal inhibition of 77% at 48 h. In contrast, GnRHII mRNA levels significantly increased in a time-dependent fashion, reaching a maximum level of 280% at 24 h. Cotreatment of hGLCs with E2 and tamoxifen (an E2 antagonist) reversed the inhibitory and stimulatory effects of E2 on the mRNA expression of GnRHI and GnRHII, respectively. Time- and dose-dependent treatment with RU486 did not affect GnRHI mRNA levels in hGLCs. In contrast, RU486 treatment significantly increased GnRHII mRNA levels in hGLCs in a time- and dose-dependent fashion, with a maximum increase being observed at 24 h (with 10−5m RU486). In summary, the present study demonstrated that the expression of GnRHI and GnRHII at the transcriptional level is differently regulated by E2 and P4 in hGLCs.


Blood ◽  
1997 ◽  
Vol 90 (6) ◽  
pp. 2345-2356 ◽  
Author(s):  
Hiroshi Deguchi ◽  
Hiroyuki Takeya ◽  
Hideo Wada ◽  
Esteban C. Gabazza ◽  
Nobuyuki Hayashi ◽  
...  

AbstractDilazep, an antiplatelet agent, is generally used as an antithrombotic drug in clinical practice. Dilazep is also known to exert cytoprotective and antioxidant effects on endothelial cells. However, its effect on the endothelial or monocyte procoagulant activity is unknown. In the current study, the effect of dilazep on the expression of tissue factor (TF ) in human umbilical vein endothelial cells (HUVECs) after the stimulation with tumor necrosis factor-α (TNF ), thrombin, or phorbol 12-myristate 13-acetate (PMA) was evaluated. We also evaluated the effect of dilazep on TNF (1,000 U/mL)-induced TF expression on monocytes. Dilazep inhibited TF activity induced on HUVECs by each stimulant, TNF (1000 U/mL), thrombin (25 nmol/L), or PMA (5 nmol/L) in a dose-dependent fashion (1 to 100 μg/mL). TF activity decreased to approximately 10% after treating with 100 μg/mL of dilazep. Dilazep also blocked the expression of TF antigen induced by each stimulant on the surface of HUVECs as determined by flow cytometric analysis. In addition, in HUVECs, it significantly decreased the expression of TF mRNA and the total TF antigen induced by thrombin or PMA, but not those induced by TNF, suggesting that dilazep blocks the TF expression induced by PMA or thrombin at a transcriptional level and that induced by TNF at a posttranscriptional level. Western blot analysis showed that dilazep reduces the accumulation of native TF but increases that in lower molecular weight TF derivatives. The adenosine receptor antagonist, 8-(p-sulfophenyl) theophylline, partially counteracted the anticoagulant activity of dilazep on HUVECs, thereby suggesting that the inhibitory effect of dilazep on TF expression in HUVECs depends, at least in part, on its adenosine potentiating activity. Dilazep also inhibited TNF-induced TF expression on monocytes in a dose-dependent fashion (0.1 to 100 μg/mL). In brief, the current study showed for the first time that dilazep, a commonly used antiplatelet drug, strongly inhibits the TF expression in HUVECs and monocytes. Dilazep may have a potent therapeutic value in patients with hypercoagulable state for its inhibitory property on the procoagulant activity of endothelial cells and monocytes.


Blood ◽  
1997 ◽  
Vol 90 (6) ◽  
pp. 2345-2356 ◽  
Author(s):  
Hiroshi Deguchi ◽  
Hiroyuki Takeya ◽  
Hideo Wada ◽  
Esteban C. Gabazza ◽  
Nobuyuki Hayashi ◽  
...  

Dilazep, an antiplatelet agent, is generally used as an antithrombotic drug in clinical practice. Dilazep is also known to exert cytoprotective and antioxidant effects on endothelial cells. However, its effect on the endothelial or monocyte procoagulant activity is unknown. In the current study, the effect of dilazep on the expression of tissue factor (TF ) in human umbilical vein endothelial cells (HUVECs) after the stimulation with tumor necrosis factor-α (TNF ), thrombin, or phorbol 12-myristate 13-acetate (PMA) was evaluated. We also evaluated the effect of dilazep on TNF (1,000 U/mL)-induced TF expression on monocytes. Dilazep inhibited TF activity induced on HUVECs by each stimulant, TNF (1000 U/mL), thrombin (25 nmol/L), or PMA (5 nmol/L) in a dose-dependent fashion (1 to 100 μg/mL). TF activity decreased to approximately 10% after treating with 100 μg/mL of dilazep. Dilazep also blocked the expression of TF antigen induced by each stimulant on the surface of HUVECs as determined by flow cytometric analysis. In addition, in HUVECs, it significantly decreased the expression of TF mRNA and the total TF antigen induced by thrombin or PMA, but not those induced by TNF, suggesting that dilazep blocks the TF expression induced by PMA or thrombin at a transcriptional level and that induced by TNF at a posttranscriptional level. Western blot analysis showed that dilazep reduces the accumulation of native TF but increases that in lower molecular weight TF derivatives. The adenosine receptor antagonist, 8-(p-sulfophenyl) theophylline, partially counteracted the anticoagulant activity of dilazep on HUVECs, thereby suggesting that the inhibitory effect of dilazep on TF expression in HUVECs depends, at least in part, on its adenosine potentiating activity. Dilazep also inhibited TNF-induced TF expression on monocytes in a dose-dependent fashion (0.1 to 100 μg/mL). In brief, the current study showed for the first time that dilazep, a commonly used antiplatelet drug, strongly inhibits the TF expression in HUVECs and monocytes. Dilazep may have a potent therapeutic value in patients with hypercoagulable state for its inhibitory property on the procoagulant activity of endothelial cells and monocytes.


2017 ◽  
Vol 43 (4) ◽  
pp. 1449-1459 ◽  
Author(s):  
Renata A. C. Silva ◽  
Andréa F. Gonçalves ◽  
Priscila P. dos Santos ◽  
Bruna Rafacho ◽  
Renan F. T. Claro ◽  
...  

Background/Aims: This study aimed to discern whether the cardiac alterations caused by retinoic acid (RA) in normal adult rats are physiologic or pathologic. Methods and Results: Wistar rats were assigned into four groups: control animals (C, n = 20) received a standard rat chow; animals fed a diet supplemented with 0.3 mg/kg/day all-trans-RA (AR1, n = 20); animals fed a diet supplemented with 5 mg/kg/day all-trans-RA (AR2, n = 20); and animals fed a diet supplemented with 10 mg/kg/day all-trans-RA (AR3, n = 20). After 2 months, the animals were submitted to echocardiogram, isolated heart study, histology, energy metabolism status, oxidative stress condition, and the signaling pathway involved in the cardiac remodeling induced by RA. RA increased myocyte cross-sectional area in a dose-dependent manner. The treatment did not change the morphological and functional variables, assessed by echocardiogram and isolated heart study. In contrast, RA changed catalases, superoxide dismutase, and glutathione peroxidases and was associated with increased values of lipid hydroperoxide, suggesting oxidative stress. RA also reduced citrate synthase, enzymatic mitochondrial complex II, ATP synthase, and enzymes of fatty acid metabolism and was associated with increased enzymes involved in glucose use. In addition, RA increased JNK 1/2 expression, without changes in TGF-β, PI3K, AKT, NFκB, S6K, and ERK. Conclusion: In normal rats, RA induces cardiac hypertrophy in a dose-dependent manner. The non-participation of the PI3K/Akt pathway, associated with the participation of the JNK pathway, oxidative stress, and changes in energy metabolism, suggests that cardiac remodeling induced by RA supplementation is deleterious.


2016 ◽  
Vol 94 (2) ◽  
pp. 129-137 ◽  
Author(s):  
Eleonora A. Starikova ◽  
Alexey V. Sokolov ◽  
Anna Yu. Vlasenko ◽  
Larisa A. Burova ◽  
Irina S. Freidlin ◽  
...  

Streptococcus pyogenes (group A Streptococcus; GAS) is an important gram-positive extracellular bacterial pathogen responsible for a number of suppurative infections. This micro-organism has developed complex virulence mechanisms to avoid the host’s defenses. We have previously reported that SDSC from GAS type M22 causes endothelial-cell dysfunction, and inhibits cell adhesion, migration, metabolism, and proliferation in a dose-dependent manner, without affecting cell viability. This work aimed to isolate and characterize a component from GAS type M22 supernatant that suppresses the proliferation of endothelial cells (EA.hy926). In the process of isolating a protein possessing antiproliferative activity we identified arginine deiminase (AD). Further study showed that this enzyme is most active at pH 6.8. Calculating Km and Vmax gave the values of 0.67 mmol·L–1 and 42 s−1, respectively. A distinctive feature of AD purified from GAS type M22 is that its optimum activity and the maximal rate of the catalytic process is close to neutral pH by comparison with enzymes from other micro-organisms. AD from GAS type M22 suppressed the proliferative activity of endothelial cells in a dose-dependent mode. At the same time, in the presence of AD, the proportion of cells in G0/G1 phase increased. When l-Arg was added at increasing concentrations to the culture medium containing AD (3 μg·mL–1), the enzyme’s capacity to inhibit cell proliferation became partially depressed. The proportion of cells in phases S/G2 increased concomitantly, although the cells did not fully recover their proliferation activity. This suggests that AD from GAS type M22 has potential for the suppression of excessive cell proliferation.


2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Purum Kang ◽  
Seung Ho Han ◽  
Hea Kyung Moon ◽  
Jeong-Min Lee ◽  
Hyo-Keun Kim ◽  
...  

The purpose of the present study is to examine the effects of essential oil ofCitrus bergamiaRisso (bergamot, BEO) on intracellular Ca2+in human umbilical vein endothelial cells. Fura-2 fluorescence was used to examine changes in intracellular Ca2+concentration[Ca2+]i. In the presence of extracellular Ca2+, BEO increased[Ca2+]i, which was partially inhibited by a nonselective Ca2+channel blocker La3+. In Ca2+-free extracellular solutions, BEO increased[Ca2+]iin a concentration-dependent manner, suggesting that BEO mobilizes intracellular Ca2+. BEO-induced[Ca2+]iincrease was partially inhibited by a Ca2+-induced Ca2+release inhibitor dantrolene, a phospholipase C inhibitor U73122, and an inositol 1,4,5-triphosphate (IP3)-gated Ca2+channel blocker, 2-aminoethoxydiphenyl borane (2-APB). BEO also increased[Ca2+]iin the presence of carbonyl cyanide m-chlorophenylhydrazone, an inhibitor of mitochondrial Ca2+uptake. In addition, store-operated Ca2+entry (SOC) was potentiated by BEO. These results suggest that BEO mobilizes Ca2+from primary intracellular stores via Ca2+-induced and IP3-mediated Ca2+release and affect promotion of Ca2+influx, likely via an SOC mechanism.


2021 ◽  
Author(s):  
Ahmed M Hamdan ◽  
Zuhair M. Mohammedsaleh ◽  
Aalaa Aboelnour ◽  
Sherif M.H. Elkhannishi

Abstract PurposeThe therapeutic activity of Glyceryl trinitrate (GTN) is mainly regulated by liberating nitric oxide (NO) and reactive nitrogen species (RNS). During this biotransformation, oxidative stress and lipid peroxidation inside the red blood cells (RBCs) occur. The principal objective of our research is to explain the ameliorating effect of L-ascorbic acid for the deleterious effects of chronic administration of nitrovasodilator drugs. MethodsWe studied some biochemical parameters for the oxidative stress using groups of high sucrose/fat (HSF) diet Wistar male rats chronically orally administered ISMN. Afterwards, we evaluated the role of L-ascorbic acid against these biochemical changes. ResultsChronic treatment with organic nitrates caused elevated serum levels of lipid peroxidation, hemoglobin derivatives as methemoglobin and carboxyhemoglobin, rate of hemoglobin autoxidation, the cellular levels of pro-inflammatory cytokines marker (NF-κB) and apoptosis markers (caspase-3) in myocardium muscles in a dose dependent manner. Meanwhile, such exposure caused decline in the enzymatic effect of superoxide dismutase (SOD), glutathione (GSH) and catalase activity (CAT) accompanied with a decrease of in the level of mitochondrial oxidative stress marker (nrf2) in myocardium muscles and decrease in the serum iron and total iron binding capacity (TIBC) in a dose dependent manner. Concomitant treatment with L-ascorbic acid significantly diminished these changes for all examined parameters.ConclusionChronic administration of organic nitrates leads to the alteration of the level of oxidative stress factors in the myocardium tissue due to generation of reactive oxygen species. Using vitamin C can effectively ameliorate such intoxication to overcome the nitrate tolerance.


2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Martha Lappas

A prominent feature of inflammatory diseases is endothelial dysfunction. Factors associated with endothelial dysfunction include proinflammatory cytokines, adhesion molecules, and matrix degrading enzymes. At the transcriptional level, they are regulated by the histone deacetylase sirtuin (SIRT) 1 via its actions on the proinflammatory transcription factor nuclear factor-κB (NF-κB). The role of SIRT6, also a histone deacetylase, in regulating inflammation in endothelial cells is not known. The aim of this study was to determine the effect of SIRT6 knockdown on inflammatory markers in human umbilical vein endothelial cells (HUVECs) in the presence of lipopolysaccharide (LPS). LPS decreased expression of SIRT6 in HUVECs. Knockdown of SIRT6 increased the expression of proinflammatory cytokines (IL-1β, IL-6, IL-8), COX-prostaglandin system, ECM remodelling enzymes (MMP-2, MMP-9 and PAI-1), the adhesion molecule ICAM-1, and proangiogenic growth factors VEGF and FGF-2; cell migration; cell adhesion to leukocytes. Loss of SIRT6 increased the expression of NF-κB, whereas overexpression of SIRT6 was associated with decreased NF-κB transcriptional activity. Taken together, these results demonstrate that the loss of SIRT6 in endothelial cells is associated with upregulation of genes involved in inflammation, vascular remodelling, and angiogenesis. SIRT6 may be a potential pharmacological target for inflammatory vascular diseases.


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