Impact of endothelin blockade on acute exercise-induced changes in blood flow and endothelial function in type 2 diabetes mellitus.

Science.gov (United States)

Schreuder, Tim H A; van Lotringen, Jaap H; Hopman, Maria T E; Thijssen, Dick H J

2014-09-01

Positive vascular effects of exercise training are mediated by acute increases in blood flow. Type 2 diabetes patients show attenuated exercise-induced increases in blood flow, possibly mediated by the endothelin pathway, preventing an optimal stimulus for vascular adaptation. We examined the impact of endothelin receptor blockade (bosentan) on exercise-induced blood flow in the brachial artery and on pre- and postexercise endothelial function in type 2 diabetes patients (n = 9, 60 ± 7 years old) and control subjects (n = 10, 60 ± 5 years old). Subjects reported twice to the laboratory to perform hand-grip exercise in the presence of endothelin receptor blockade or placebo. We examined brachial artery endothelial function (via flow-mediated dilatation) before and after exercise, as well as blood flow during exercise. Endothelin receptor blockade resulted in a larger increase in blood flow during exercise in type 2 diabetes patients (P = 0.046), but not in control subjects (P = 0.309). Exercise increased shear rate across the exercise protocol, unaffected by endothelin receptor blockade. Exercise did not alter brachial artery diameter in either group, but endothelin receptor blockade resulted in a larger brachial artery diameter in type 2 diabetes patients (P = 0.033). Exercise significantly increased brachial artery flow-mediated dilatation in both groups, unaffected by endothelin receptor blockade. Endothelin receptor blockade increased exercise-induced brachial artery blood flow in type 2 diabetes patients, but not in control subjects. Despite this effect of endothelin receptor blockade on blood flow, we found no impact on baseline or post-exercise endothelial function in type 2 diabetes patients or control subjects, possibly related to normalization of the shear stimulus during exercise. The successful increase in blood flow during exercise in type 2 diabetes patients through endothelin receptor blockade may have beneficial effects in

Intraportal nicotine infusion in rats decreases hepatic blood flow through endothelin-1 and both endothelin A and endothelin B receptors

International Nuclear Information System (INIS)

Hashimoto, Takashi; Yoneda, Masashi; Shimada, Tadahito; Kurosawa, Mieko; Terano, Akira

2004-01-01

Smoking has been demonstrated to aggravate liver injury. Nicotine, a major pharmacological component of tobacco smoke, affects a multitude of functions. Smoking and nicotine induce synthesis of endothelin (ET)-1. The effect of intraportal infusion of nicotine on hepatic circulation and an involvement of ET-1 and ET receptor in the action of nicotine were investigated in rats. Nicotine (0-100 μg/kg/h) was infused into the portal vein of urethane-anesthetized rats, and changes of hepatic blood flow were evaluated. Intraportal infusion of nicotine dose-dependently decreased hepatic blood flow and increased portal pressure without any alteration of heart rate or arterial blood pressure. This action of intraportal nicotine was completely abolished by pretreatment of ET-1 antibody. Either BQ485 (ET A receptor antagonist) or BQ788 (ET B receptor antagonist) partially reversed the effect of nicotine, and combination of BQ788 and BQ485 completely abolished it. These findings suggest that nicotine inhibits hepatic circulation through ET-1, and ET A and ET B receptor

Physical activity opposes the age-related increase in skeletal muscle and plasma endothelin-1 levels and normalizes plasma endothelin-1 levels in individuals with essential hypertension

DEFF Research Database (Denmark)

Nyberg, Michael Permin; Mortensen, Stefan Peter; Hellsten, Ylva

2013-01-01

performed lifelong physical activity had similar plasma and muscle endothelin-1 levels as the young controls and had higher ET(A) receptor levels. CONCLUSION: Our findings suggest that aerobic exercise training opposes the age-related increase in skeletal muscle and plasma endothelin-1 levels and normalizes......AIMS: Endothelin-1 has potent constrictor and proliferative activity in vascular smooth muscle, and essential hypertension and aging are associated with increased endothelin-1-mediated vasoconstrictor tone. The aim of this study was to investigate the effect of physical activity, hypertension...... and age on endothelin-1 levels in plasma and skeletal muscle and endothelin receptors in skeletal muscle in human subjects. METHODS: In study 1, normotensive (46 ± 1 years, n = 11) and hypertensive (47 ± 1 years, n = 10) subjects were studied before and after 8 weeks of aerobic exercise training. In study...

Physical activity opposes the age-related increase in skeletal muscle and plasma endothelin-1 levels and normalizes plasma endothelin-1 levels in individuals with essential hypertension.

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Nyberg, M; Mortensen, S P; Hellsten, Y

2013-03-01

Endothelin-1 has potent constrictor and proliferative activity in vascular smooth muscle, and essential hypertension and aging are associated with increased endothelin-1-mediated vasoconstrictor tone. The aim of this study was to investigate the effect of physical activity, hypertension and age on endothelin-1 levels in plasma and skeletal muscle and endothelin receptors in skeletal muscle in human subjects. In study 1, normotensive (46 ± 1 years, n = 11) and hypertensive (47 ± 1 years, n = 10) subjects were studied before and after 8 weeks of aerobic exercise training. In study 2, young (23 ± 1 years, n = 8), older lifelong sedentary (66 ± 2 years, n = 8) and older lifelong endurance-trained (62 ± 2 years, n = 8) subjects were studied in a cross-sectional design. Skeletal muscle and plasma endothelin-1 levels were increased with age and plasma endothelin-1 levels were higher in hypertensive than normotensive individuals. Eight weeks of exercise training normalized plasma endothelin-1 levels in the hypertensive subjects and increased the protein expression of the ET(A) receptor in skeletal muscle of normotensive subjects. Similarly, individuals that had performed lifelong physical activity had similar plasma and muscle endothelin-1 levels as the young controls and had higher ET(A) receptor levels. Our findings suggest that aerobic exercise training opposes the age-related increase in skeletal muscle and plasma endothelin-1 levels and normalizes plasma endothelin-1 levels in individuals with essential hypertension. This effect may explain some of the beneficial effects of training on the cardiovascular system in older and hypertensive subjects. © 2012 The Authors Acta Physiologica © 2012 Scandinavian Physiological Society.

Cerebrovascular endothelin receptor upregulation in cerebral ischemia

DEFF Research Database (Denmark)

Edvinsson, Lars

2009-01-01

Stroke is a serious neurological disease and the third leading cause of death in the western world. In roughly 15 % of the cases, the cause is due to an intracranial haemorrhage, and the remaining 85 % represent ischemic strokes. Ischemic stroke is caused by the occlusion of a cerebral artery...... either by an embolus or by local thrombosis. Several studies have shown an involvement of the endothelin system in ischemic stroke. This review aims to examine the alterations of vascular endothelin receptor expression in ischemic stroke. Furthermore, studies of the intracellular signalling pathways...... leading to the enhanced expression of vascular endothelin receptors show that both protein kinase C (PKC) and mitogen activating protein kinase (MAPK) play important roles. The results from this work provide new perspectives on the pathophysiology of ischemic stroke, and give a possible explanation...

G-231A and G+70C polymorphisms of endothelin receptor type-A gene could affect the psoriasis area and severity index score and endothelin 1 levels

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Gökhan Okan

2015-01-01

Full Text Available Background: The etiopathogenesis of psoriasis has not been clearly elucidated although the role of chronic inflammation, imbalance between pro- and anti-inflammatory cytokines, and many immunological events have been established. Endothelin 1 (EDN1 and endothelin receptor type-A (EDNRA are implicated in the inflammatory process. The relationships between EDN1 and EDNRA polymorphisms with several diseases have been found. Aims and Objectives: This study examined the possible association of EDN1 (G5665T and T-1370G and EDNRA (G-231A and G + 70C single nucleotide polymorphisms (SNPs with the occurence of psoriasis, and evaluated the relationship between genotypes and clinical/laboratory manifestation of psoriasis. Materials and Methods: We analyzed genotype and allele distributions of the above-mentioned polymorphisms in 151 patients with psoriasis and 152 healthy controls by real-time PCR combined with melting curve analysis. Results: We did not find significant differences in the genotype and allele distributions of EDN1 T-1370G, EDNRA G-231A, and EDNRA G+70C polymorphisms between patients with psoriasis and healthy controls. Psoriasis area and severity index (PASI score of EDNRA -231 polymorphic A allele carrying subjects (AA and AA + AG was higher than that of wild homozygotes (P = 0.044 and P = 0.027, respectively. In addition, EDN1 levels in EDNRA+70 polymorphic C allele carriers (CC + CG were elevated when compared with GG genotype; however, the difference was at borderline significance (P = 0.05. Conclusion: Although there were no associations between studied polymorphisms and psoriasis susceptibility, the PASI score and EDN1 levels seem to be affected by EDNRA G-231A and G + 70C polymorphisms.

Slow receptor dissociation kinetics differentiate macitentan from other endothelin receptor antagonists in pulmonary arterial smooth muscle cells.

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John Gatfield

Full Text Available Two endothelin receptor antagonists (ERAs, bosentan and ambrisentan, are currently approved for the treatment of pulmonary arterial hypertension (PAH, a devastating disease involving an activated endothelin system and aberrant contraction and proliferation of pulmonary arterial smooth muscle cells (PASMC. The novel ERA macitentan has recently concluded testing in a Phase III morbidity/mortality clinical trial in PAH patients. Since the association and dissociation rates of G protein-coupled receptor antagonists can influence their pharmacological activity in vivo, we used human PASMC to characterize inhibitory potency and receptor inhibition kinetics of macitentan, ambrisentan and bosentan using calcium release and inositol-1-phosphate (IP(1 assays. In calcium release assays macitentan, ambrisentan and bosentan were highly potent ERAs with K(b values of 0.14 nM, 0.12 nM and 1.1 nM, respectively. Macitentan, but not ambrisentan and bosentan, displayed slow apparent receptor association kinetics as evidenced by increased antagonistic potency upon prolongation of antagonist pre-incubation times. In compound washout experiments, macitentan displayed a significantly lower receptor dissociation rate and longer receptor occupancy half-life (ROt(1/2 compared to bosentan and ambrisentan (ROt(1/2:17 minutes versus 70 seconds and 40 seconds, respectively. Because of its lower dissociation rate macitentan behaved as an insurmountable antagonist in calcium release and IP(1 assays, and unlike bosentan and ambrisentan it blocked endothelin receptor activation across a wide range of endothelin-1 (ET-1 concentrations. However, prolongation of the ET-1 stimulation time beyond ROt(1/2 rendered macitentan a surmountable antagonist, revealing its competitive binding mode. Bosentan and ambrisentan behaved as surmountable antagonists irrespective of the assay duration and they lacked inhibitory activity at high ET-1 concentrations. Thus, macitentan is a competitive

CPU0213, a novel endothelin type A and type B receptor antagonist, protects against myocardial ischemia/reperfusion injury in rats

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Z.Y. Wang

2011-11-01

Full Text Available The efficacy of endothelin receptor antagonists in protecting against myocardial ischemia/reperfusion (I/R injury is controversial, and the mechanisms remain unclear. The aim of this study was to investigate the effects of CPU0123, a novel endothelin type A and type B receptor antagonist, on myocardial I/R injury and to explore the mechanisms involved. Male Sprague-Dawley rats weighing 200-250 g were randomized to three groups (6-7 per group: group 1, Sham; group 2, I/R + vehicle. Rats were subjected to in vivo myocardial I/R injury by ligation of the left anterior descending coronary artery and 0.5% sodium carboxymethyl cellulose (1 mL/kg was injected intraperitoneally immediately prior to coronary occlusion. Group 3, I/R + CPU0213. Rats were subjected to identical surgical procedures and CPU0213 (30 mg/kg was injected intraperitoneally immediately prior to coronary occlusion. Infarct size, cardiac function and biochemical changes were measured. CPU0213 pretreatment reduced infarct size as a percentage of the ischemic area by 44.5% (I/R + vehicle: 61.3 ± 3.2 vs I/R + CPU0213: 34.0 ± 5.5%, P < 0.05 and improved ejection fraction by 17.2% (I/R + vehicle: 58.4 ± 2.8 vs I/R + CPU0213: 68.5 ± 2.2%, P < 0.05 compared to vehicle-treated animals. This protection was associated with inhibition of myocardial inflammation and oxidative stress. Moreover, reduction in Akt (protein kinase B and endothelial nitric oxide synthase (eNOS phosphorylation induced by myocardial I/R injury was limited by CPU0213 (P < 0.05. These data suggest that CPU0123, a non-selective antagonist, has protective effects against myocardial I/R injury in rats, which may be related to the Akt/eNOS pathway.

Endothelin B receptors contribute to retinal ganglion cell loss in a rat model of glaucoma.

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Alena Z Minton

Full Text Available Glaucoma is an optic neuropathy, commonly associated with elevated intraocular pressure (IOP characterized by optic nerve degeneration, cupping of the optic disc, and loss of retinal ganglion cells which could lead to loss of vision. Endothelin-1 (ET-1 is a 21-amino acid vasoactive peptide that plays a key role in the pathogenesis of glaucoma; however, the receptors mediating these effects have not been defined. In the current study, endothelin B (ET(B receptor expression was assessed in vivo, in the Morrison's ocular hypertension model of glaucoma in rats. Elevation of IOP in Brown Norway rats produced increased expression of ET(B receptors in the retina, mainly in retinal ganglion cells (RGCs, nerve fiber layer (NFL, and also in the inner plexiform layer (IPL and inner nuclear layer (INL. To determine the role of ET(B receptors in neurodegeneration, Wistar-Kyoto wild type (WT and ET(B receptor-deficient (KO rats were subjected to retrograde labeling with Fluoro-Gold (FG, following which IOP was elevated in one eye while the contralateral eye served as control. IOP elevation for 4 weeks in WT rats caused an appreciable loss of RGCs, which was significantly attenuated in KO rats. In addition, degenerative changes in the optic nerve were greatly reduced in KO rats compared to those in WT rats. Taken together, elevated intraocular pressure mediated increase in ET(B receptor expression and its activation may contribute to a decrease in RGC survival as seen in glaucoma. These findings raise the possibility of using endothelin receptor antagonists as neuroprotective agents for the treatment of glaucoma.

Overexpression of endothelin B receptor in glioblastoma: a prognostic marker and therapeutic target?

KAUST Repository

Vasaikar, Suhas; Tsipras, Giorgos; Landá zuri, Natalia; Costa, Helena; Wilhelmi, Vanessa; Scicluna, Patrick; Cui, Huanhuan L.; Mohammad, Abdul-Aleem; Davoudi, Belghis; Shang, Mingmei; Ananthaseshan, Sharan; Strå å t, Klas; Stragliotto, Giuseppe; Rahbar, Afsar; Wong, Kum Thong; Tegner, Jesper; Yaiw, Koon-Chu; Sö derberg-Naucler, Cecilia

2018-01-01

of endothelin B receptor (ETBR) has been demonstrated in gliomas, we aimed to test whether ETBR is a useful prognostic marker in GBM and examine if the clinically available endothelin receptor antagonists (ERA) could be useful in the disease treatment

The inhibition of the potassium channel TASK-1 in rat cardiac muscle by endothelin-1 is mediated by phospholipase C.

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Schiekel, Julia; Lindner, Moritz; Hetzel, Andrea; Wemhöner, Konstantin; Renigunta, Vijay; Schlichthörl, Günter; Decher, Niels; Oliver, Dominik; Daut, Jürgen

2013-01-01

The two-pore-domain potassium channel TASK-1 is robustly inhibited by the activation of receptors coupled to the Gα(q) subgroup of G-proteins, but the signal transduction pathway is still unclear. We have studied the mechanisms by which endothelin receptors inhibit the current carried by TASK-1 channels (I(TASK)) in cardiomyocytes. Patch-clamp measurements were carried out in isolated rat cardiomyocytes. I(TASK) was identified by extracellular acidification to pH 6.0 and by the application of the TASK-1 blockers A293 and A1899. Endothelin-1 completely inhibited I(TASK) with an EC(50) of Application of 20 nM endothelin-1 caused a significant increase in action potential duration under control conditions; this was significantly reduced after pre-incubation of the cardiomyocytes with 200 nM A1899. The inhibition of I(TASK) by endothelin-1 was not affected by inhibitors of protein kinase C or rho kinase, but was strongly reduced by U73122, an inhibitor of phospholipase C (PLC). The ability of endothelin-1 to activate PLC-mediated signalling pathways was examined in mammalian cells transfected with TASK-1 and the endothelin-A receptor using patch-clamp measurements and total internal reflection microscopy. U73122 prevented the inhibition of I(TASK) by endothelin-1 and blocked PLC-mediated signalling, as verified with a fluorescent probe for phosphatidylinositol-(4,5)-bisphosphate hydrolysis. Our results show that I(TASK) in rat cardiomyocytes is controlled by endothelin-1 and suggest that the inhibition of TASK-1 via endothelin receptors is mediated by the activation of PLC. The prolongation of the action potential observed with 20 nM endothelin-1 was mainly due to the inhibition of I(TASK).

Structural determinants for selective recognition of peptide ligands for endothelin receptor subtypes ETA and ETB.

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Lättig, Jens; Oksche, Alexander; Beyermann, Michael; Rosenthal, Walter; Krause, Gerd

2009-07-01

The molecular basis for recognition of peptide ligands endothelin-1, -2 and -3 in endothelin receptors is poorly understood. Especially the origin of ligand selectivity for ET(A) or ET(B) is not clearly resolved. We derived sequence-structure-function relationships of peptides and receptors from mutational data and homology modeling. Our major findings are the dissection of peptide ligands into four epitopes and the delineation of four complementary structural portions on receptor side explaining ligand recognition in both endothelin receptor subtypes. In addition, structural determinants for ligand selectivity could be described. As a result, we could improve the selectivity of BQ3020 about 10-fold by a single amino acid substitution, validating our hypothesis for ligand selectivity caused by different entrances to the receptors' transmembrane binding sites. A narrow tunnel shape in ET(A) is restrictive for a selected group of peptide ligands' N-termini, whereas a broad funnel-shaped entrance in ET(B) accepts a variety of different shapes and properties of ligands.

In depth pharmacological characterization of endothelin B receptors in the rat middle cerebral artery

DEFF Research Database (Denmark)

Szok, D; Hansen-Schwartz, J; Edvinsson, L

2001-01-01

Whereas the endothelin A receptor is generally believed to mediate vasoconstriction; the endothelin B receptor seems elusive; both dilative and constrictive responses have been reported. Using the in vitro arteriograph, a method allowing compartmentalized study of vessel segments, segments of rat...

Upregulation of contractile endothelin type B receptors by lipid-soluble cigarette smoking particles in rat cerebral arteries via activation of MAPK

International Nuclear Information System (INIS)

Sandhu, Hardip; Xu, Cang Bao; Edvinsson, Lars

2010-01-01

Cigarette smoke exposure increases the risk of stroke. However, the underlying molecular mechanisms are poorly understood. Endothelin system plays key roles in the pathogenesis of stroke. The present study was designed to examine if lipid-soluble (dimethyl sulfoxide-soluble) cigarette smoke particles (DSP) induces upregulation of contractile endothelin type B (ET B ) receptors in rat cerebral arteries and if activation of mitogen activated protein kinase (MAPK) and nuclear factor-kappaB (NF-κB) mediate the upregulation of contractile endothelin receptors in the cerebral arteries. Rat middle cerebral arteries were isolated and organ cultured in serum free medium for 24 h in the presence of DSP with or without specific inhibitors: MEK specific (U0126), p38 specific (SB202190), JNK specific (SP600125), NF-κB specific (BMS-345541) or (IMD-0354), transcription inhibitor (actinomycin D), or translation blocker (cycloheximide). Contractile responses to the ET B receptor agonist sarafotoxin 6c were investigated by a sensitive myograph. The expression of the ET B receptors were studied at mRNA and protein levels using quantitative real time PCR and immunohistochemistry, respectively. Results show that organ culture per se induced transcriptional upregulation of contractile ET B receptors in the cerebral vascular smooth muscle cells. This upregulation was further increased at the translational level by addition of DSP to the organ culture, but this increase was not seen by addition of nicotine or water-soluble cigarette smoke particles to the organ culture. The increased upregulation of contractile ET B receptors by DSP was abrogated by U0126, SP600125, actinomycin D, and cycloheximide, suggesting that the underlying molecular mechanisms involved in this process include activation of MEK and JNK MAPK-mediated transcription and translation of new contractile ET B receptors. Thus, the MAPK-mediated upregulation of contractile ET B receptors in cerebral arteries might be a

Iontophoresis of endothelin receptor antagonists in rats and men.

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Matthieu Roustit

Full Text Available The treatment of scleroderma-related digital ulcers is challenging. The oral endothelin receptor antagonist (ERA bosentan has been approved but it may induce liver toxicity. The objective of this study was to test whether ERAs bosentan and sitaxentan could be locally delivered using iontophoresis.Cathodal and anodal iontophoresis of bosentan and sitaxentan were performed on anaesthetized rat hindquarters without and during endothelin-1 infusion. Skin blood flow was quantified using laser-Doppler imaging and cutaneous tolerability was assessed. Iontophoresis of sitaxentan (20 min, 20 or 100 µA was subsequently performed on the forearm skin of healthy men (n = 5.In rats neither bosentan nor sitaxentan increased skin blood flux compared to NaCl. When simultaneously infusing endothelin-1, cathodal iontophoresis of sitaxentan increased skin blood flux compared to NaCl (AUC(0-20 were 44032.2 ± 12277 and 14957.5 ± 23818.8 %BL.s, respectively; P = 0.01. In humans, sitaxentan did not significantly increase skin blood flux as compared to NaCl. Iontophoresis of ERAs was well tolerated both in animals and humans.This study shows that cathodal iontophoresis of sitaxentan but not bosentan partially reverses endothelin-induced skin vasoconstriction in rats, suggesting that sitaxentan diffuses into the dermis. However, sitaxentan does not influence basal skin microvascular tone in rats or in humans.

The heart as an extravascular target of endothelin-1 in ...

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Exposure to particulate matter air pollution has been causally linked to cardiovascular disease in humans. Several broad and overlapping hypotheses describing the biological mechanisms by which particulate matter exposure leads to cardiovascular disease and cardiac dysfunction have been explored, though linkage with specific factors or genes remains limited. Given evidence pointing to autocrine/paracrine signaling systems as modulators of cardiac dysfunction, the present review highlights the emerging role of endothelins as mediators of cardiac dysfunction following particulate matter exposure. Endothelin-1 is a small multifunctional protein expressed in the pulmonary and cardiovascular system, known for its ability to constrict blood vessels. Although endothelin-1 can also directly and indirectly (via secondary signaling events) modulate cardiac contractility, heart rate, and rhythm, research on the role of endothelins in the context of air pollution has tended to focus on the vascular effects. The plausibility of endothelin as a mechanism underlying particulate matter-induced cardiac dysfunction is further supported by the therapeutic utility of certain endothelin receptor antagonists. Extravascular effects of endothelin on the heart could better explain one mechanism by which particulate matter exposure may lead to cardiac dysfunction. We propose and support the novel hypothesis that autocrine/paracrine signaling systems, such as endothelins, mediate cardiac

Role of ERK/MAPK in endothelin receptor signaling in human aortic smooth muscle cells

DEFF Research Database (Denmark)

Chen, Qing-wen; Edvinsson, Lars; Xu, Cang-Bao

2009-01-01

muscle cells (VSMCs) through activation of endothelin type A (ETA) and type B (ETB) receptors. The extracellular signal-regulated kinase 1 and 2 (ERK1/2) mitogen-activated protein kinases (MAPK) are involved in ET-1-induced VSMC contraction and proliferation. This study was designed to investigate...... agonist, Sarafotoxin 6c (S6c) caused a time-dependent ERK1/2 activation with a maximal effect by less than 20% of the ET-1-induced activation of ERK1/2. Increase in bosentan concentration up to 10 microM further inhibited ET-1-induced activation of ERK1/2 and had a stronger inhibitory effect than BQ123...

Endothelin-1 is associated with fibrosis in proliferative diabetic retinopathy membranes.

Science.gov (United States)

Chang, William; Lajko, Michelle; Fawzi, Amani A

2018-01-01

To characterize the relationship between endothelin-1 and fibrosis in epiretinal membranes in proliferative diabetic retinopathy and explore the role of endothelial-mesenchymal transition in these membranes. Membranes were obtained from eyes undergoing pars plana vitrectomy for complicated proliferative diabetic retinopathy or idiopathic epiretinal membrane. Through standard immunohistochemical techniques, we labeled membranes to explore the distribution of endothelin-1 and endothelin receptor B, comparing proliferative diabetic retinopathy and idiopathic epiretinal membranes. In addition, membranes were also labeled with markers for fibroblasts, endothelial, and glial cells and studied with confocal laser scanning microscopy. The intensity of endothelin-1 labeling was quantified using standard image analysis software. Fourteen membranes were included in the analysis, nine from eyes with proliferative diabetic retinopathy and five idiopathic membranes. Flatmount diabetic membranes showed co-localization of endothelin-1 with S100A4 and CD31. Immunohistochemistry and quantitative analysis of cross-sectional membranes showed significantly higher endothelin-1 labeling in proliferative diabetic retinopathy membranes compared to idiopathic membranes (pmembranes showed more elements staining positive for S100A4 compared to idiopathic membranes. Epiretinal membrane formation in proliferative diabetic retinopathy involves higher tissue levels of endothelin-1 and fibroblastic activity. Furthermore, endothelin-1, endothelial and fibroblastic staining appear to be correlated, suggestive of endothelial-to-mesenchymal transition in proliferative diabetic retinopathy.

Airborne fine particulate matter induces an upregulation of endothelin receptors on rat bronchi

International Nuclear Information System (INIS)

Wang, Rong; Xiao, Xue; Cao, Lei; Shen, Zhen-xing; Lei, Ying; Cao, Yong-xiao

2016-01-01

Airborne fine particulate matter (PM2.5) is a risk factor for respiratory diseases. However, little is known about the effects of PM2.5 on bronchi. The present study investigated the effect of airborne PM2.5 on rat bronchi and the underlying mechanisms. Isolated rat bronchial segments were cultured for 24 h. Endothelin (ET) receptor-mediated contractile responses were recorded using a wire myograph. The mRNA and protein expression levels of ET receptors were studied using quantitative real-time PCR, Western blotting, and immunohistochemistry. The results demonstrated that ET A and ET B receptor agonists induced remarkable contractile responses on fresh and cultured bronchial segments. PM2.5 (1.0 or 3.0 μg/ml) significantly enhanced ET A and ET B receptor-mediated contractile responses in bronchi with a markedly increased maximal contraction compared to the DMSO or fresh groups. PM2.5 increased the mRNA and protein expression levels of ET A and ET B receptors. U0126 (a MEK1/2 inhibitor) and SB203580 (a p38 inhibitor) significantly suppressed PM2.5-induced increases in ET B receptor-mediated contractile responses, mRNA and protein levels. SP600125 (a JNK inhibitor) and SB203580 significantly abrogated the PM2.5-induced enhancement of ET A receptor-mediated contraction and receptor expression. In conclusion, PM2.5 upregulates ET receptors in bronchi. ET B receptor upregulation is associated with MEK1/2 and p38 pathways, and the upregulation of ET A receptor is involved in JNK and p38 pathways. - Highlights: • Airborne PM2.5 induces bronchial hyperreactivity mediated with endothelin ET B and ET A receptors in rats. • PM2.5 increases mRNA and protein expressions of endothelin ET B and ET A receptors in bronchi. • The upregulation of ET B receptor is associated with MEK1/2 and p38 pathways. • The upregulation of ET A receptor is involved in JNK and p38 pathways. • The research provides novel understanding for PM2.5-associated respiratory diseases.

The Association of Endothelin-1 Signaling with Bone Alkaline Phosphatase Expression and Protumorigenic Activities in Canine Osteosarcoma.

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Neumann, Z L; Pondenis, H C; Masyr, A; Byrum, M L; Wycislo, K L; Fan, T M

2015-01-01

Canine osteosarcoma (OS) is an aggressive sarcoma characterized by pathologic skeletal resorption and pulmonary metastases. A number of negative prognostic factors, including bone alkaline phosphatase, have been identified in dogs with OS, but the underlying biologic factors responsible for such observations have not been thoroughly investigated. Endothelin-1-mediated signaling is active during bone repair, and is responsible for osteoblast migration, survival, proliferation, and bone alkaline phosphatase expression. The endothelin-1 signaling axis is active in canine OS cells, and this pathway is utilized by malignant osteoblasts for promoting cellular migration, survival, proliferation, and bone alkaline phosphatase activities. 45 dogs with appendicular OS. The expressions of endothelin-1 and endothelin A receptor were studied in OS cell lines and in samples from spontaneously occurring tumors. Activities mediated by endothelin-1 signaling were investigated by characterizing responses in 3 OS cell lines. In 45 dogs with OS, bone alkaline phosphatase concentrations were correlated with primary tumor osteoproductivity. Canine OS cells express endothelin-1 and endothelin A receptor, and this signaling axis mediates OS migration, survival, proliferation, and bone alkaline phosphatase activities. In OS-bearing dogs, circulating bone alkaline phosphatase activities were positively correlated with primary tumor relative bone mineral densities. Canine OS cells express endothelin-1 and functional endothelin A receptors, with the potential for a protumorigenic signaling loop. Increases in bone alkaline phosphatase activity are associated with osteoblastic OS lesions, and might be an epiphenomenon of active endothelin-1 signaling or excessive osteoproduction within the localized bone microenvironment. Copyright © 2015 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.

Novel nonsense mutation of the endothelin-B receptor gene in a family with Waardenburg-Hirschsprung disease.

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Syrris, P; Carter, N D; Patton, M A

1999-11-05

Waardenburg syndrome (WS) comprises sensorineural hearing loss, hypopigmentation of skin and hair, and pigmentary disturbances of the irides. Four types of WS have been classified to date; in WS type IV (WS4), patients additionally have colonic aganglionosis (Hirschsprung disease, HSCR). Mutations in the endothelin-3 (EDN3), endothelin-B receptor (EDNRB), and Sox10 genes have been identified as causative for WS type IV. We screened a family with a combined WS-HSCR phenotype for mutations in the EDNRB locus using standard DNA mutation analysis and sequencing techniques. We have identified a novel nonsense mutation at codon 253 (CGA-->TGA, Arg-->STOP). This mutation leads to a premature end of the translation of EDNRB at exon 3, and it is predicted to produce a truncated and nonfunctional endothelin-B receptor. All affected relatives were heterozygous for the Arg(253)-->STOP mutation, whereas it was not observed in over 50 unrelated individuals used as controls. These data confirm the role of EDNRB in the cause of the Waardenburg-Hirschsprung syndrome and demonstrate that in WS-HSCR there is a lack of correlation between phenotype and genotype and a variable expression of disease even within the same family. Copyright 1999 Wiley-Liss, Inc.

Cerebrovascular endothelin-1 hyper-reactivity is associated with transient receptor potential canonical channels 1 and 6 activation and delayed cerebral hypoperfusion after forebrain ischaemia in rats

DEFF Research Database (Denmark)

Johansson, S E; Andersen, X E D R; Hansen, R H

2015-01-01

. METHODS: Experimental forebrain ischaemia was induced in Wistar male rats by a two-vessel occlusion model, and the cerebral blood flow was measured by magnetic resonance imaging two days after reperfusion. In vitro vasoreactivity studies, immunofluorescence and quantitative PCR were performed on cerebral...... in the vascular smooth muscle cells was enhanced and correlated with decreased cerebral blood flow two days after forebrain ischaemia. Furthermore, under conditions when voltage-dependent calcium channels were inhibited, endothelin-1-induced cerebrovascular contraction was enhanced and this enhancement...... was presumably mediated by Ca(2+) influx via upregulated transient receptor potential canonical channels 1 and 6. CONCLUSIONS: Our data demonstrates that endothelin-1-mediated influx of extracellular Ca(2+) activates transient receptor potential canonical channels 1 and 6 in cerebral vascular smooth muscle cells...

Endothelin B receptor blockade attenuates pulmonary vasodilation in oxygen-ventilated fetal lambs.

Science.gov (United States)

Ivy, D Dunbar; Lee, Dong-Seok; Rairigh, Robyn L; Parker, Thomas A; Abman, Steven H

2004-01-01

Endothelin-1 (ET-1) contributes to the regulation of pulmonary vascular tone in the normal ovine fetus and in models of perinatal pulmonary hypertension. In the fetal lamb lung, the effects of ET-1 depend on the balance of at least two endothelin receptor subtypes: ETA and ETB. ETA receptors are located on smooth muscle cells and mediate vasoconstriction and smooth muscle proliferation. Stimulation of endothelial ETB receptors causes vasodilation through release of nitric oxide and also functions to remove ET-1 from the circulation. However, whether activation of ETB receptors contributes to the fall in pulmonary vascular tone at birth is unknown. To determine the role of acute ETB receptor blockade in pulmonary vasodilation in response to birth-related stimuli, we studied the hemodynamic effects of selective ETB receptor blockade with BQ-788 during mechanical ventilation with low (<10%) and high FiO2 (100%) in near-term fetal sheep. Intrapulmonary infusion of BQ-788 did not change left pulmonary artery (LPA) blood flow and pulmonary vascular resistance (PVR) at baseline. In comparison with controls, BQ-788 treatment attenuated the rise in LPA flow with low and high FiO2 ventilation (p <0.001 vs. control for each FiO2 concentration). PVR progressively decreased during mechanical ventilation with low and high FiO2 in both groups, but PVR remained higher after BQ-788 treatment throughout the study period (p <0.001). We conclude that selective ETB receptor blockade attenuates pulmonary vasodilation at birth. We speculate that ETB receptor stimulation contributes to pulmonary vasodilation at birth in the ovine fetus.

Celecoxib offsets the negative renal influences of cyclosporine via modulation of the TGF-β1/IL-2/COX-2/endothelin ET(B) receptor cascade.

Science.gov (United States)

El-Gowelli, Hanan M; Helmy, Maged W; Ali, Rabab M; El-Mas, Mahmoud M

2014-03-01

Endothelin (ET) signaling provokes nephrotoxicity induced by the immunosuppressant drug cyclosporine A (CSA). We tested the hypotheses that (i): celecoxib, a selective cyclooxygenase-2 (COX-2) inhibitor, counterbalances renal derangements caused by CSA in rats and (ii) the COX-2/endothelin ET(B) receptor signaling mediates the CSA-celecoxib interaction. Ten-day treatment with CSA (20 mg/kg/day) significantly increased biochemical indices of renal function (serum urea, creatinine), inflammation (interleukin-2, IL-2) and fibrosis (transforming growth factor-β₁, TGF-β₁). Histologically, CSA caused renal tubular atrophy along with interstitial fibrosis. These detrimental renal effects of CSA were largely reduced in rats treated concurrently with celecoxib (10 mg/kg/day). We also report that cortical glomerular and medullary tubular protein expressions of COX-2 and ET(B) receptors were reduced by CSA and restored to near-control values in rats treated simultaneously with celecoxib. The importance of ET(B) receptors in renal control and in the CSA-celecoxib interaction was further verified by the findings (i) most of the adverse biochemical, inflammatory, and histopathological profiles of CSA were replicated in rats treated with the endothelin ETB receptor antagonist BQ788 (0.1 mg/kg/day, 10 days), and (ii) the BQ788 effects, like those of CSA, were alleviated in rats treated concurrently with celecoxib. Together, the data suggest that the facilitation of the interplay between the TGF-β1/IL-2/COX-2 pathway and the endothelin ET(B) receptors constitutes the cellular mechanism by which celecoxib ameliorates the nephrotoxic manifestations of CSA in rats. Copyright © 2014 Elsevier Inc. All rights reserved.

Effects of Combined Endothelin A Receptor and Renin-Angiotensin System Blockade on the Course of End-Organ Damage in 5/6 Nephrectomized Ren-2 Hypertensive Rats

Czech Academy of Sciences Publication Activity Database

Vaněčková, Ivana; Kujal, P.; Husková, Z.; Vaňourková, Z.; Vernerová, Z.; Čertíková; Chábová, V.; Škaroupková, P.; Kramer, H. J.; Tesař, V.; Červenka, L.

2012-01-01

Roč. 35, č. 5 (2012), s. 382-392 ISSN 1420-4096 Institutional research plan: CEZ:AV0Z50110509 Keywords : 5/6 nephrectomy * Endothelin receptor type A * AT1 receptor blocker * end-organ damage * hypertension Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery Impact factor: 1.596, year: 2012

Significance of the Melanocortin 1 and Endothelin B Receptors in Melanocyte Homeostasis and Prevention of Sun-Induced Genotoxicity

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Zalfa A. Abdel-Malek

2016-08-01

Full Text Available The membrane bound melanocortin 1 receptor (MC1R, and the endothelin B receptor (ENDBR are two G-protein coupled receptors that play important roles in constitutive regulation of melanocytes and their response to ultraviolet radiation (UVR, the main etiological factor for melanoma. The human MC1R is a Gs protein-coupled receptor, which is activated by its agonists α-melanocyte stimulating hormone (α-melanocortin; α-MSH and adrenocorticotropic hormone (ACTH. The ENDBR is a Gq coupled-receptor, which is activated by Endothelin (ET-3 during embryonic development, and ET-1 postnatally. Pigmentation and the DNA repair capacity are two major factors that determine the risk for melanoma. Activation of the MC1R by its agonists stimulates the synthesis of eumelanin, the dark brown photoprotective pigment. In vitro studies showed that α-MSH and ET-1 interact synergistically in the presence of basic fibroblast growth factor (bFGF to stimulate human melanocyte proliferation and melanogenesis, and to inhibit UVR-induced apoptosis. An important function of the MC1R is reduction of oxidative stress and activation of DNA repair pathways. The human MC1R is highly polymorphic, and MC1R variants, particularly those that cause loss of function of the expressed receptor, are associated with increased melanoma risk independently of pigmentation. These variants compromise the DNA repair and antioxidant capacities of human melanocytes. Recently, activation of ENDBR by ET-1 was reported to reduce the induction and enhance the repair of UVR-induced DNA photoproducts. We conclude that α-MSH and ET-1 and their cognate receptors MC1R and ENDBR reduce the risk for melanoma by maintaining genomic stability of melanocytes via modulating the DNA damage response to solar UVR. Elucidating the response of melanocytes to UVR should improve our understanding of the process of melanomagenesis, and lead to effective melanoma chemoprevention, as well as therapeutic strategies.

Endothelin receptor a blockade is an ineffective treatment for adriamycin nephropathy.

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Roderick J Tan

Full Text Available Endothelin is a vasoconstricting peptide that plays a key role in vascular homeostasis, exerting its biologic effects via two receptors, the endothelin receptor A (ETA and endothelin receptor B (ETB. Activation of ETA and ETB has opposing actions, in which hyperactive ETA is generally vasoconstrictive and pathologic. Selective ETA blockade has been shown to be beneficial in renal injuries such as diabetic nephropathy and can improve proteinuria. Atrasentan is a selective pharmacologic ETA blocker that preferentially inhibits ETA activation. In this study, we evaluated the efficacy of ETA blockade by atrasentan in ameliorating proteinuria and kidney injury in murine adriamycin nephropathy, a model of human focal segmental glomerulosclerosis. We found that ETA expression was unaltered during the course of adriamycin nephropathy. Whether initiated prior to injury in a prevention protocol (5 mg/kg/day, i.p. or after injury onset in a therapeutic protocol (7 mg/kg or 20 mg/kg three times a week, i.p., atrasentan did not significantly affect the initiation and progression of adriamycin-induced albuminuria (as measured by urinary albumin-to-creatinine ratios. Indices of glomerular damage were also not improved in atrasentan-treated groups, in either the prevention or therapeutic protocols. Atrasentan also failed to improve kidney function as determined by serum creatinine, histologic damage, and mRNA expression of numerous fibrosis-related genes such as collagen-I and TGF-β1. Therefore, we conclude that selective blockade of ETA by atrasentan has no effect on preventing or ameliorating proteinuria and kidney injury in adriamycin nephropathy.

Insulin decreases atherosclerosis by inducing endothelin receptor B expression

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Park, Kyoungmin; Mima, Akira; Li, Qian

2016-01-01

Endothelial cell (EC) insulin resistance and dysfunction, caused by diabetes, accelerates atherosclerosis. It is unknown whether specifically enhancing EC-targeted insulin action can decrease atherosclerosis in diabetes. Accordingly, overexpressing insulin receptor substrate-1 (IRS1...... induction of NO action, which increases endothelin receptor B (EDNRB) expression and intracellular [Ca(2+)]. Using the mice with knockin mutation of eNOS, which had Ser1176 mutated to alanine (AKI), deleting the only known mechanism for insulin to activate eNOS/NO pathway, we observed that IRS1...... overexpression in the endothelia of Aki/ApoE(-/-) mice significantly decreased atherosclerosis. Interestingly, endothelial EDNRB expression was selectively reduced in intima of arteries from diabetic patients and rodents. However, endothelial EDNRB expression was upregulated by insulin via P13K/Akt pathway...

Regulatory mechanism of endothelin receptor B in the cerebral arteries after focal cerebral ischemia

DEFF Research Database (Denmark)

Grell, Anne-Sofie; Thigarajah, Rushani; Edvinsson, Lars

2014-01-01

BACKGROUND AND PURPOSE: Increased expression of endothelin receptor type B (ETBR), a vasoactive receptor, has recently been implied in the reduced cerebral blood flow and exacerbated neuronal damage after ischemia-reperfusion (I/R). The study explores the regulatory mechanisms of ETBR to identify...... drug targets to restore normal cerebral artery contractile function as part of successful neuroprotective therapy. METHODS: We have employed in vitro methods on human and rat cerebral arteries to study the regulatory mechanisms and the efficacy of target selective inhibitor, Mithramycin A (Mit...... the ETBR mRNA and protein levels. It also significantly reduced the ETBR mediated cerebrovascular contractility. Detailed analysis indicated that ERK1/2 mediated phosphorylation of Sp1 might be essential for ETBR transcription. CONCLUSION: Transcription factor Sp1 regulates the ETBR mediated...

Effect of the dual endothelin receptor antagonist bosentan on untreatable skin ulcers in a patient with diabetes: a case report

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Brito Suárez Manuel

2011-04-01

Full Text Available Abstract Introduction Refractory skin ulcers are a major burden in patients with diabetes. Their pathogenesis is multifactorial, and data increasingly implicate endothelin as a mediator of diabetic macro- and microvasculopathy. Here we describe the first reported case of an endothelin receptor antagonist being used to successfully treat refractory skin ulcers in a patient with diabetes. Case presentation An 85-year-old Caucasian man with a 30-year history of type 2 diabetes developed multiple skin ulcerations, including a right heel ulcer. Despite appropriate treatment, the ulcer showed little improvement and the risk of amputation was high. The patient was treated with the dual endothelin receptor antagonist bosentan. After three weeks of treatment, major improvements were observed, and after 21 weeks, all ulcers had healed. No abnormalities were observed during monitoring of blood pressure, erythrocyte sedimentation rate or serum aminotransferase levels. Conclusion In patients with refractory ulceration associated with diabetes, bosentan may be of real benefit, especially in terms of amputation prevention. This case supports the proposed role for endothelin in the pathogenesis of skin ulceration in diabetes and is suggestive of a potential benefit of bosentan in this patient type. This case report is of interest to diabetologists and dermatologists.

Endothelin-1 and endothelin-3 in cirrhosis: relations to systemic and splanchnic haemodynamics

DEFF Research Database (Denmark)

Møller, S; Gülberg, V; Gerbes, A L

1995-01-01

correlated with the hepatic venous pressure gradient (r = 0.61, p blood pressure (r = -0.31, p blood volume (-0.36, p ... haemodynamics. METHODS: Endothelin-1 and endothelin-3 were measured in samples from a hepatic vein and the femoral artery in 42 patients with cirrhosis, eight hypertensive controls and 10 normotensive controls. RESULTS: Hepatic venous endothelin-1 was significantly higher in the patients with cirrhosis, mean 21.......002). The same pattern was found in arterial endothelin-3. Hepatic venous endothelin-3 correlated significantly with central and arterial blood volume (r = 0.56, p

Endothelin-1 activation of ETB receptors leads to a reduced cellular proliferative rate and an increased cellular footprint

International Nuclear Information System (INIS)

Wilson, Jamie L.; Taylor, Linda; Polgar, Peter

2012-01-01

Endothelin-1 (ET-1) is a vasoactive peptide which signals through two G-protein coupled receptors, endothelin receptor A (ETA) and B (ETB). We determined that ET-1 activation of its ETB receptor in stably cDNA transfected CHO cells leads to a 55% reduction in cell number by end-point cell counting and a 35% decrease in cell growth by a real-time cell-substrate impedance-based assay after 24 h of cell growth. When CHO ETB cells were synchronized in the late G1 cell cycle phase, ET-1 delayed their S phase progression compared to control by 30% as determined by [ 3 H]-thymidine incorporation. On the other hand, no such delay was observed during late G2/M to G1 transit when cells were treated with ET-1 after release from mitotic arrest. Using the cell-substrate impedance-based assay, we observed that ET-1 induces opposing morphological changes in CHO ETA and CHO ETB cells with ETB causing an increase in the cell footprint and ETA a decrease. Likewise, in pulmonary artery smooth muscle cells, which express both ETA and ETB receptors, ET-1 induces an ETA-dependent contraction and an ETB dependent dilation. These results are shedding light on a possible beneficial role for ETB in diseases involving ET-1 dysfunction such as pulmonary hypertension. -- Highlights: ► ET- hinders cell proliferation in CHO cells transfected with ETB. ► ET-1 also decreases the rate of DNA synthesis in CHO ETB cells. ► JNK and PI3K appear to be involved in this reduction of DNA synthesis. ► ETB activation in CHO ETB cells and hSMCs leads to dilatory morphological changes. ► In CHO ETA and hSMCs, ETA activation leads to constrictive morphological changes.

Endothelin-1 activation of ETB receptors leads to a reduced cellular proliferative rate and an increased cellular footprint

Energy Technology Data Exchange (ETDEWEB)

Wilson, Jamie L.; Taylor, Linda; Polgar, Peter, E-mail: peterp@bu.edu

2012-06-10

Endothelin-1 (ET-1) is a vasoactive peptide which signals through two G-protein coupled receptors, endothelin receptor A (ETA) and B (ETB). We determined that ET-1 activation of its ETB receptor in stably cDNA transfected CHO cells leads to a 55% reduction in cell number by end-point cell counting and a 35% decrease in cell growth by a real-time cell-substrate impedance-based assay after 24 h of cell growth. When CHO ETB cells were synchronized in the late G1 cell cycle phase, ET-1 delayed their S phase progression compared to control by 30% as determined by [{sup 3}H]-thymidine incorporation. On the other hand, no such delay was observed during late G2/M to G1 transit when cells were treated with ET-1 after release from mitotic arrest. Using the cell-substrate impedance-based assay, we observed that ET-1 induces opposing morphological changes in CHO ETA and CHO ETB cells with ETB causing an increase in the cell footprint and ETA a decrease. Likewise, in pulmonary artery smooth muscle cells, which express both ETA and ETB receptors, ET-1 induces an ETA-dependent contraction and an ETB dependent dilation. These results are shedding light on a possible beneficial role for ETB in diseases involving ET-1 dysfunction such as pulmonary hypertension. -- Highlights: Black-Right-Pointing-Pointer ET- hinders cell proliferation in CHO cells transfected with ETB. Black-Right-Pointing-Pointer ET-1 also decreases the rate of DNA synthesis in CHO ETB cells. Black-Right-Pointing-Pointer JNK and PI3K appear to be involved in this reduction of DNA synthesis. Black-Right-Pointing-Pointer ETB activation in CHO ETB cells and hSMCs leads to dilatory morphological changes. Black-Right-Pointing-Pointer In CHO ETA and hSMCs, ETA activation leads to constrictive morphological changes.

The insulinotropic effect of endothelin-1 is mediated by glucagon release from the islet alpha cells

DEFF Research Database (Denmark)

Brock, B; Gregersen, S; Kristensen, K

1999-01-01

AIMS/HYPOTHESIS: The circulating concentrations of endothelin-1 (ET-1), a peptide derived from endothelium, are increased in hypertension and diabetes. Endothelin-1 has recently been shown to be an insulinotropic agent. The mechanism of action of endothelin-1 on the endocrine pancreas has not yet...... been clarified. METHODS: We investigated the action of endothelin-1 on the insulin secretion, the binding of (125)I-ET-1 to beta cells as well as its effects on purified beta and non-beta cells from normal rats. The expression of endothelin receptors in alpha- and beta-cell lines and in normal rat...... from purified beta cells. Endothelin-1-(100 nmol/l) increased, however, both insulin and glucagon secretion from a mixture of purified beta and non-beta cells indicating that alpha cells seem to have a key role for the action of ET-1 on insulin secretion. CONCLUSION/INTERPRETATION: The insulinotropic...

Orphan Nuclear Receptor Nur77 Is a Novel Negative Regulator of Endothelin-1 Expression In Vascular Endothelial Cells

OpenAIRE

Qin, Qing; Chen, Ming; Yi, Bing; You, Xiaohua; Yang, Ping; Sun, Jianxin

2014-01-01

Endothelin-1 (ET-1) produced by vascular endothelial cells plays essential roles in the regulation of vascular tone and development of cardiovascular diseases. The objective of this study is to identify novel regulators implicated in the regulation of ET-1 expression in vascular endothelial cells (ECs). By using quantitative real-time PCR (qRT-PCR) and Enzyme-linked immunosorbent assay (ELISA), we show that either ectopic expression of orphan nuclear receptor Nur77 or pharmacological activati...

Murine study of portal hypertension associated endothelin-1 hypo-response.

Science.gov (United States)

Theodorakis, Nicholas; Maluccio, Mary; Skill, Nicholas

2015-04-28

To investigate endothelin-1 hypo-responsive associated with portal hypertension in order to improve patient treatment outcomes. Wild type, eNOS(-/-) and iNOS(-/-) mice received partial portal vein ligation surgery to induce portal hypertension or sham surgery. Development of portal hypertension was determined by measuring the splenic pulp pressure, abdominal aortic flow and portal systemic shunting. To measure splenic pulp pressure, a microtip pressure transducer was inserted into the spleen pulp. Abdominal aortic flow was measured by placing an ultrasonic Doppler flow probe around the abdominal aorta between the diaphragm and celiac artery. Portal systemic shunting was calculated by injection of fluorescent microspheres in to the splenic vein and determining the percentage accumulation of spheres in liver and pulmonary beds. Endothelin-1 hypo-response was evaluated by measuring the change in abdominal aortic flow in response to endothelin-1 intravenous administration. In addition, thoracic aorta endothelin-1 contraction was measured in 5 mm isolated thoracic aorta rings ex-vivo using an ADI small vessel myograph. In wild type and iNOS(-/-) mice splenic pulp pressure increased from 7.5 ± 1.1 mmHg and 7.2 ± 1 mmHg to 25.4 ± 3.1 mmHg and 22 ± 4 mmHg respectively. In eNOS(-/-) mice splenic pulp pressure was increased after 1 d (P = NS), after which it decreased and by 7 d was not significantly elevated when compared to 7 d sham operated controls (6.9 ± 0.6 mmHg and 7.3 ± 0.8 mmHg respectively, P = 0.3). Abdominal aortic flow was increased by 80% and 73% in 7 d portal vein ligated wild type and iNOS when compared to shams, whereas there was no significant difference in 7 d portal vein ligated eNOS(-/-) mice when compared to shams. Endothelin-1 induced a rapid reduction in abdominal aortic blood flow in wild type, eNOS(-/-) and iNOS(-/-) sham mice (50% ± 8%, 73% ± 9% and 47% ± 9% respectively). Following portal vein ligation endothelin-1 reduction in blood flow

Pancreatic acini possess endothelin receptors whose internalization is regulated by PLC-activating agents.

Science.gov (United States)

Hildebrand, P; Mrozinski, J E; Mantey, S A; Patto, R J; Jensen, R T

1993-05-01

Endothelin-1 (ET-1) and ET-3 mRNA have been found in the pancreas. We investigated the ability of ET-1, ET-2, and ET-3 to interact with and alter dispersed rat pancreatic acinar cell function. Radiolabeled ETs bound in a time- and temperature-dependent fashion, which was specific and saturable. Analysis demonstrated two classes of receptors, one class (ETA receptor) had a high affinity for ET-1 but a low affinity for ET-3, and the other class (ETB receptor) had equally high affinities for ET-1 and ET-3. No specific receptor for ET-2 was identified. Pancreatic secretagogues that activate phospholipase C (PLC) inhibited binding of 125I-labeled ET-1 (125I-ET-1) or 125I-ET-3, whereas agents that act through adenosine 3',5'-cyclic monophosphate (cAMP) did not. A23187 had no effect on 125I-ET-1 or 125I-ET-3 binding, whereas the phorbol ester 12-O-tetradecanoylphorbol 13-acetate reduced binding. The effect of cholecystokinin octapeptide (CCK-8) was mediated through its own receptor. Stripping of surface bound ligand studies demonstrated that both 125I-labeled ET-1 and 125I-labeled ET-3 were rapidly internalized. CCK-8 decreased the internalization but did not change the amount of surface bound ligand. Endothelins neither stimulate nor alter changes in enzyme secretion, intracellular calcium, cAMP, or [3H]inositol trisphosphate (IP3). This study demonstrates the presence of ETA and ETB receptors on rat pancreatic acini; occupation of both receptors resulted in rapid internalization, which is regulated by PLC-activating secretagogues. Occupation of either ET receptor did not alter intracellular calcium, cAMP, IP3, or stimulate amylase release.

25 Years of endothelin research

DEFF Research Database (Denmark)

Emoto, Noriaki; Vignon-Zellweger, Nicolas; Lopes, Rhéure Alves Moreira

2014-01-01

In the past three decades, endothelin and endothelin receptor antagonists have received great scientific and clinical interest, leading to the publication of more than 27,000 scientific articles since its discovery. The Thirteenth International Conference on Endothelin (ET-13) was held on Septemb...

The emerging role of endothelin-1 in the pathogenesis of pre-eclampsia.

Science.gov (United States)

Saleh, Langeza; Verdonk, Koen; Visser, Willy; van den Meiracker, Anton H; Danser, A H Jan

2016-10-01

Pre-eclampsia (PE) is the most frequently encountered medical complication during pregnancy. It is characterized by a rise in systemic vascular resistance with a relatively low cardiac output and hypovolemia, combined with severe proteinuria. Despite the hypovolemia, renin-angiotensin system (RAS) activity is suppressed and aldosterone levels are decreased to the same degree as renin. This suggests that the RAS is not the cause of the hypertension in PE, but rather that its suppression is the consequence of the rise in blood pressure. Abnormal placentation early in pregnancy is widely assumed to be an important initial event in the onset of PE. Eventually, this results in the release of anti-angiogenic factors [in particular, soluble Fms-like tyrosine kinase-1 (sFlt-1)] and cytokines, leading to generalized vascular dysfunction. Elevated sFlt-1 levels bind and inactivate vascular endothelial growth factor (VEGF). Of interest, VEGF inhibition with drugs like sunitinib, applied in cancer patients, results in a PE-like syndrome, characterized by hypertension, proteinuria and renal toxicity. Both in cancer patients treated with sunitinib and in pregnant women with PE, significant rises in endothelin-1 occur. Multiple regression analysis revealed that endothelin-1 is an independent determinant of the hypertension and proteinuria in PE, and additionally a renin suppressor. Moreover, studies in animal models representative of PE, have shown that endothelin receptor blockers prevent the development of this disease. Similarly, endothelin receptor blockers are protective during sunitinib treatment. Taken together, activation of the endothelin system emerges as an important pathway causing the clinical manifestations of PE. This paper critically addresses this concept, taking into consideration both clinical and preclinical data, and simultaneously discusses the therapeutic consequences of this observation. © The Author(s), 2016.

Stimuli of sensory-motor nerves terminate arterial contractile effects of endothelin-1 by CGRP and dissociation of ET-1/ET(A)-receptor complexes

DEFF Research Database (Denmark)

Meens, Merlijn J P M T; Compeer, Matthijs G; Hackeng, Tilman M

2010-01-01

of the antagonists and (ii) can be selectively dissociated by an endogenous counterbalancing mechanism. METHODOLOGY/PRINCIPAL FINDINGS: In isolated rat mesenteric resistance arteries, ET(A)-antagonists, endothelium-derived relaxing factors and synthetic vasodilators transiently reduced contractile effects of ET-1......BACKGROUND: Endothelin-1 (ET-1), a long-acting paracrine mediator, is implicated in cardiovascular diseases but clinical trials with ET-receptor antagonists were not successful in some areas. We tested whether the quasi-irreversible receptor-binding of ET-1 (i) limits reversing effects...... but did not prevent persistent effects of the peptide. Stimuli of peri-vascular vasodilator sensory-motor nerves such as capsaicin not only reduced but also terminated long-lasting effects of ET-1. This was prevented by CGRP-receptor antagonists and was mimicked by exogenous calcitonin gene...

Subarachnoid hemorrhage enhances endothelin receptor expression and function in rat cerebral arteries

DEFF Research Database (Denmark)

Hansen-Schwartz, Jacob; Hoel, Natalie Løvland; Zhou, Mingfang

2003-01-01

OBJECTIVE: Inspired by organ culture-induced changes in the vascular endothelin (ET) receptor population, we investigated whether such changes occur in cerebral arteries in a rat subarachnoid hemorrhage (SAH) model. METHODS: SAH was induced with injection of 250 microl of blood into the prechiasm......OBJECTIVE: Inspired by organ culture-induced changes in the vascular endothelin (ET) receptor population, we investigated whether such changes occur in cerebral arteries in a rat subarachnoid hemorrhage (SAH) model. METHODS: SAH was induced with injection of 250 microl of blood...... into the prechiasmatic cistern. After 2 days, the middle cerebral artery, basilar artery, and posterior communicating artery were harvested. Pharmacological studies were performed in vitro, and levels of messenger ribonucleic acid (mRNA) were quantified in real-time reverse transcriptase-polymerase chain reaction assays....... RESULTS: In the middle cerebral artery and basilar artery from rats with induced SAH, enhanced biphasic responses to ET-1 were observed. The -log(50% effective concentration) value for the high-affinity phase was approximately 12, compared with approximately 8.5 for sham-operated animals...

A feed-forward regulation of endothelin receptors by c-Jun in human non-pigmented ciliary epithelial cells and retinal ganglion cells.

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Junming Wang

Full Text Available c-Jun, c-Jun N-terminal kinase(JNK and endothelin B (ETB receptor have been shown to contribute to the pathogenesis of glaucoma. Previously, we reported that an increase of c-Jun and CCAAT/enhancer binding protein β (C/EBPβ immunohistostaining is associated with upregulation of the ETB receptor within the ganglion cell layer of rats with elevated intraocular pressure (IOP. In addition, both transcription factors regulate the expression of the ETB receptor in human non-pigmented ciliary epithelial cells (HNPE. The current study addressed the mechanisms by which ET-1 produced upregulation of ET receptors in primary rat retinal ganglion cells (RGCs and HNPE cells. Treatment of ET-1 and ET-3 increased the immunocytochemical staining of c-Jun and C/EBPβ in primary rat RGCs and co-localization of both transcription factors was observed. A marked increase in DNA binding activity of AP-1 and C/EBPβ as well as elevated protein levels of c-Jun and c-Jun-N-terminal kinase (JNK were detected following ET-1 treatment in HNPE cells. Overexpression of ETA or ETB receptor promoted the upregulation of c-Jun and also elevated its promoter activity. In addition, upregulation of C/EBPβ augmented DNA binding and mRNA expression of c-Jun, and furthermore, the interaction of c-Jun and C/EBPβ was confirmed using co-immunoprecipitation. Apoptosis of HNPE cells was identified following ET-1 treatment, and overexpression of the ETA or ETB receptor produced enhanced apoptosis. ET-1 mediated upregulation of c-Jun and C/EBPβ and their interaction may represent a novel mechanism contributing to the regulation of endothelin receptor expression. Reciprocally, c-Jun was also found to regulate the ET receptors and C/EBPβ appeared to play a regulatory role in promoting expression of c-Jun. Taken together, the data suggests that ET-1 triggers the upregulation of c-Jun through both ETA and ETB receptors, and conversely c-Jun also upregulates endothelin receptor expression

Endothelin Regulates Porphyromonas gingivalis-Induced Production of Inflammatory Cytokines.

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Ga-Yeon Son

Full Text Available Periodontitis is a very common oral inflammatory disease that results in the destruction of supporting connective and osseous tissues of the teeth. Although the exact etiology is still unclear, Gram-negative bacteria, especially Porphyromonas gingivalis in subgingival pockets are thought to be one of the major etiologic agents of periodontitis. Endothelin (ET is a family of three 21-amino acid peptides, ET-1, -2, and -3, that activate G protein-coupled receptors, ETA and ETB. Endothelin is involved in the occurrence and progression of various inflammatory diseases. Previous reports have shown that ET-1 and its receptors, ETA and ETB are expressed in the periodontal tissues and, that ET-1 levels in gingival crevicular fluid are increased in periodontitis patients. Moreover, P. gingivalis infection has been shown to induce the production of ET-1 along with other inflammatory cytokines. Despite these studies, however, the functional significance of endothelin in periodontitis is still largely unknown. In this study, we explored the cellular and molecular mechanisms of ET-1 action in periodontitis using human gingival epithelial cells (HGECs. ET-1 and ETA, but not ETB, were abundantly expressed in HGECs. Stimulation of HGECs with P. gingivalis or P. gingivalis lipopolysaccharide increased the expression of ET-1 and ETA suggesting the activation of the endothelin signaling pathway. Production of inflammatory cytokines, IL-1β, TNFα, and IL-6, was significantly enhanced by exogenous ET-1 treatment, and this effect depended on the mitogen-activated protein kinases via intracellular Ca2+ increase, which resulted from the activation of the phospholipase C/inositol 1,4,5-trisphosphate pathway. The inhibition of the endothelin receptor-mediated signaling pathway with the dual receptor inhibitor, bosentan, partially ameliorated alveolar bone loss and immune cell infiltration. These results suggest that endothelin plays an important role in P. gingivalis

Binding sites for endothelin-1 in rat tissues: An autoradiographic study

International Nuclear Information System (INIS)

Koseki, C.; Imai, M.; Hirata, Y.; Yanagisawa, M.; Masaki, T.

1989-01-01

By tissue autoradiography in the rat, we demonstrated that receptors for endothelin-1 (ET-1) were distributed not only in the cardiovascular system but also in the noncardiovascular organs including the brain, lung, intestine, etc. In the brain, the receptors were mainly found in the basal ganglia and brainstem, in which nuclei are known to be cardiovascular regulatory sites. In addition to its direct vasoconstricting action, ET-1 may exert neural cardiovascular control as a neuropeptide

The endothelin antagonist atrasentan lowers residual albuminuria in patients with type 2 diabetic nephropathy

DEFF Research Database (Denmark)

de Zeeuw, Dick; Coll, Blai; Andress, Dennis

2014-01-01

Despite optimal treatment, including renin-angiotensin system (RAS) inhibitors, patients with type 2 diabetic nephropathy have high cardiorenal morbidity and mortality related to residual albuminuria. We evaluated whether or not atrasentan, a selective endothelin A receptor antagonist, further...... reduces albuminuria when administered concomitantly with maximum tolerated labeled doses of RAS inhibitors. We enrolled 211 patients with type 2 diabetes, urine albumin/creatinine ratios of 300-3500 mg/g, and eGFRs of 30-75 ml/min per 1.73 m(2) in two identically designed, parallel, multinational, double...... parameters returned to pretreatment levels. In conclusion, atrasentan reduced albuminuria and improved BP and lipid spectrum with manageable fluid overload-related adverse events in patients with type 2 diabetic nephropathy receiving RAS inhibitors....

Endothelin receptor antagonism in single ventricle physiology with fontan palliation: A systematic review and meta-analysis

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Gwendolyn Derk

2015-04-01

Conclusions: Bosentan was found to be a safe and well tolerated endothelin receptor antagonist in Fontan patients over 3–6 months of therapy. Bosentan use was associated with improved functional capacity. Future studies with larger sample size and longer duration are warranted to examine the long-term safety and efficacy of endothelin blockade in Fontan physiology.

Endothelin-1 Mediates Brain Microvascular Dysfunction Leading to Long-Term Cognitive Impairment in a Model of Experimental Cerebral Malaria.

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Brandi D Freeman

2016-03-01

Full Text Available Plasmodium falciparum infection causes a wide spectrum of diseases, including cerebral malaria, a potentially life-threatening encephalopathy. Vasculopathy is thought to contribute to cerebral malaria pathogenesis. The vasoactive compound endothelin-1, a key participant in many inflammatory processes, likely mediates vascular and cognitive dysfunctions in cerebral malaria. We previously demonstrated that C57BL6 mice infected with P. berghei ANKA, our fatal experimental cerebral malaria model, sustained memory loss. Herein, we demonstrate that an endothelin type A receptor (ETA antagonist prevented experimental cerebral malaria-induced neurocognitive impairments and improved survival. ETA antagonism prevented blood-brain barrier disruption and cerebral vasoconstriction during experimental cerebral malaria, and reduced brain endothelial activation, diminishing brain microvascular congestion. Furthermore, exogenous endothelin-1 administration to P. berghei NK65-infected mice, a model generally regarded as a non-cerebral malaria negative control for P. berghei ANKA infection, led to experimental cerebral malaria-like memory deficits. Our data indicate that endothelin-1 is critical in the development of cerebrovascular and cognitive impairments with experimental cerebral malaria. This vasoactive peptide may thus serve as a potential target for adjunctive therapy in the management of cerebral malaria.

A homozygous mutation in the endothelin-3 gene associated with a combined Waardenburg type 2 and Hirschsprung phenotype (Shah-Waardenburg syndrome).

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Hofstra, R M; Osinga, J; Tan-Sindhunata, G; Wu, Y; Kamsteeg, E J; Stulp, R P; van Ravenswaaij-Arts, C; Majoor-Krakauer, D; Angrist, M; Chakravarti, A; Meijers, C; Buys, C H

1996-04-01

Hirschsprung disease (HSCR) or colonic aganglionosis is a congenital disorder characterized by an absence of intramural ganglia along variable lengths of the colon resulting in intestinal obstruction. The incidence of HSCR is 1 in 5,000 live births. Mutations in the RET gene, which codes for a receptor tyrosine kinase, and in EDNRB which codes for the endothelin-B receptor, have been shown to be associated with HSCR in humans. The lethal-spotted mouse which has pigment abnormalities, but also colonic aganglionosis, carries a mutation in the gene coding for endothelin 3 (Edn3), the ligand for the receptor protein encoded by EDNRB. Here, we describe a mutation of the human gene for endothelin 3 (EDN3), homozygously present in a patient with a combined Waardenburg syndrome type 2 (WS2) and HSCR phenotype (Shah-Waardenburg syndrome). The mutation, Cys159Phe, in exon 3 in the ET-3 like domain of EDN3, presumably affects the proteolytic processing of the preproendothelin to the mature peptide EDN3. The patient's parents were first cousins. A previous child in this family had been diagnosed with a similar combination of HSCR, depigmentation and deafness. Depigmentation and deafness were present in other relatives. Moreover, we present a further indication for the involvement of EDNRB in HSCR by reporting a novel mutation detected in one of 40 unselected HSCR patients.

Progestins oppose the effects of estradiol on the endothelin-1 receptor type B in coronary arteries from ovariectomized hyperlipidemic rabbits

DEFF Research Database (Denmark)

Pedersen, Susan H; Nielsen, Lars B; Mortensen, Alicja

2008-01-01

OBJECTIVE: Progestins may be associated with the adverse cardiovascular outcomes observed with estrogen plus progestogen therapy, but the mechanism is not resolved. In this study we examined the effect of 17beta-estradiol (E2) alone and in combination with two progestins on the endothelin-1 (ET-1...

Role of Dlx6 in regulation of an endothelin-1-dependent, dHAND branchial arch enhancer

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Charité, Jeroen; McFadden, David G.; Merlo, Giorgio; Levi, Giovanni; Clouthier, David E.; Yanagisawa, Masashi; Richardson, James A.; Olson, Eric N.

2001-01-01

Neural crest cells play a key role in craniofacial development. The endothelin family of secreted polypeptides regulates development of several neural crest sublineages, including the branchial arch neural crest. The basic helix–loop–helix transcription factor dHAND is also required for craniofacial development, and in endothelin-1 (ET-1) mutant embryos, dHAND expression in the branchial arches is down-regulated, implicating it as a transcriptional effector of ET-1 action. To determine the mechanism that links ET-1 signaling to dHAND transcription, we analyzed the dHAND gene for cis-regulatory elements that control transcription in the branchial arches. We describe an evolutionarily conserved dHAND enhancer that requires ET-1 signaling for activity. This enhancer contains four homeodomain binding sites that are required for branchial arch expression. By comparing protein binding to these sites in branchial arch extracts from endothelin receptor A (EdnrA) mutant and wild-type mouse embryos, we identified Dlx6, a member of the Distal-less family of homeodomain proteins, as an ET-1-dependent binding factor. Consistent with this conclusion, Dlx6 was down-regulated in branchial arches from EdnrA mutant mice. These results suggest that Dlx6 acts as an intermediary between ET-1 signaling and dHAND transcription during craniofacial morphogenesis. PMID:11711438

Specific receptor for endothelin in cultured rat cardiocytes

International Nuclear Information System (INIS)

Hirata, Y.; Fukuda, Y.; Yoshimi, H.; Emori, T.; Shichiri, M.; Marumo, F.

1989-01-01

Specific binding sites for the endothelium-derived vasoconstrictor endothelin (ET) and its effect on cytosolic free Ca2+ concentrations [( Ca2+]i) were studied in a primary culture of cardiocytes from neonatal rats. Binding studies using 125 I-labeled-porcine ET as a radioligand revealed the presence of a single class of high-affinity binding sites for ET in cardiocytes with an apparent Kd of 6-9 x 10(-10) M and a Bmax of 50,000-80,000 sites/cell. Neither various vasoconstrictors nor Ca2+-channel blockers affected the binding. Pretreatment with ET substantially reduced the total number of ET receptors without changing their affinity. ET dose-dependently increased [Ca2+]i in fura-2-loaded cardiocytes. These data indicate that cardiocytes have specific ET receptors that are controlled by a down-regulation mechanism, and that ET induces a receptor-mediated increase in [Ca2+]i in cardiocytes

Stimuli of Sensory-Motor Nerves Terminate Arterial Contractile Effects of Endothelin-1 by CGRP and Dissociation of ET-1/ETA-Receptor Complexes

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Meens, Merlijn J. P. M. T.; Compeer, Matthijs G.; Hackeng, Tilman M.; van Zandvoort, Marc A.; Janssen, Ben J. A.; De Mey, Jo G. R.

2010-01-01

Background Endothelin-1 (ET-1), a long-acting paracrine mediator, is implicated in cardiovascular diseases but clinical trials with ET-receptor antagonists were not successful in some areas. We tested whether the quasi-irreversible receptor-binding of ET-1 (i) limits reversing effects of the antagonists and (ii) can be selectively dissociated by an endogenous counterbalancing mechanism. Methodology/Principal findings In isolated rat mesenteric resistance arteries, ETA-antagonists, endothelium-derived relaxing factors and synthetic vasodilators transiently reduced contractile effects of ET-1 but did not prevent persistent effects of the peptide. Stimuli of peri-vascular vasodilator sensory-motor nerves such as capsaicin not only reduced but also terminated long-lasting effects of ET-1. This was prevented by CGRP-receptor antagonists and was mimicked by exogenous calcitonin gene-related peptide (CGRP). Using 2-photon laser scanning microscopy in vital intact arteries, capsaicin and CGRP, but not ETA-antagonism, were observed to promote dissociation of pre-existing ET-1/ETA-receptor complexes. Conclusions Irreversible binding and activation of ETA-receptors by ET-1 (i) occur at an antagonist-insensitive site of the receptor and (ii) are selectively terminated by endogenously released CGRP. Hence, natural stimuli of sensory-motor nerves that stimulate release of endogenous CGRP can be considered for therapy of diseases involving ET-1. PMID:20532232

Involvement of endothelin and ET(A) endothelin receptor in mechanical allodynia in mice given orthotopic melanoma inoculation.

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Fujita, Masahide; Andoh, Tsugunobu; Saiki, Ikuo; Kuraishi, Yasushi

2008-02-01

We investigated whether endothelin (ET) would be involved in skin cancer pain in mice. Orthotopic inoculation of B16-BL6 melanoma cells into the plantar region of the hind paw produced marked mechanical allodynia in C57BL/6 mice. Intraplantar injections of the ET(A)-receptor antagonist BQ-123 (0.3 - 3 nmol/site), but not the ET(B)-receptor antagonist BQ-788 (1 and 3 nmol/site), inhibited mechanical allodynia in mice with grown melanoma. In naive mice, an intraplantar injection of tumor extract (1 and 3 mg/site), which was prepared from the grown melanoma in the paw, produced mechanical allodynia, which was inhibited by BQ-123 and BQ-788 at doses of 3 and 10 nmol/site. An intraplantar injection of ET-1 (1 and 10 pmol/site) elicited licking behavior, which was increased in the melanoma-bearing hind paw. BQ-123 (3 and 10 nmol/site) inhibited licking induced by ET-1 (10 pmol/site). The level of mRNA of ET(A), but not ET(B), receptor, was significantly increased in the dorsal root ganglia on the inoculated side. Cultured B16-BL6 cells contained ET, and the melanoma mass increased the concentration of ET as it grew bigger. These results suggest that ET-1 and ET(A) receptor are at least partly involved in the induction of pain induced by melanoma cell inoculation.

The vascular endothelial growth factor receptor inhibitor sunitinib causes a preeclampsia-like syndrome with activation of the endothelin system

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Kappers, Mariëtte H W; Smedts, Frank M M; Horn, Thomas

2011-01-01

of endothelin 1, decreased nitric oxide (NO) bioavailability, and increased oxidative stress in the development of sunitinib-induced hypertension and renal toxicity. In rats on sunitinib, light and electron microscopic examination revealed marked glomerular endotheliosis, a characteristic histological feature...... be prevented with the endothelin receptor antagonist macitentan (¿BP: 12.3±1.5 mm Hg) and only mildly with Tempol, a superoxide dismutase mimetic (¿BP: 25.9±2.3 mm Hg). Both compounds could not prevent the sunitinib-induced rise in serum creatinine or renal histological abnormalities and had no effect on urine...

The vascular endothelial growth factor receptor inhibitor sunitinib causes a preeclampsia-like syndrome with activation of the endothelin system

DEFF Research Database (Denmark)

Kappers, Mariëtte H W; Smedts, Frank M M; Horn, Thomas

2011-01-01

of endothelin 1, decreased nitric oxide (NO) bioavailability, and increased oxidative stress in the development of sunitinib-induced hypertension and renal toxicity. In rats on sunitinib, light and electron microscopic examination revealed marked glomerular endotheliosis, a characteristic histological feature...... be prevented with the endothelin receptor antagonist macitentan (ΔBP: 12.3±1.5 mm Hg) and only mildly with Tempol, a superoxide dismutase mimetic (ΔBP: 25.9±2.3 mm Hg). Both compounds could not prevent the sunitinib-induced rise in serum creatinine or renal histological abnormalities and had no effect on urine...

Stimuli of sensory-motor nerves terminate arterial contractile effects of endothelin-1 by CGRP and dissociation of ET-1/ET(A-receptor complexes.

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Merlijn J P M T Meens

Full Text Available BACKGROUND: Endothelin-1 (ET-1, a long-acting paracrine mediator, is implicated in cardiovascular diseases but clinical trials with ET-receptor antagonists were not successful in some areas. We tested whether the quasi-irreversible receptor-binding of ET-1 (i limits reversing effects of the antagonists and (ii can be selectively dissociated by an endogenous counterbalancing mechanism. METHODOLOGY/PRINCIPAL FINDINGS: In isolated rat mesenteric resistance arteries, ET(A-antagonists, endothelium-derived relaxing factors and synthetic vasodilators transiently reduced contractile effects of ET-1 but did not prevent persistent effects of the peptide. Stimuli of peri-vascular vasodilator sensory-motor nerves such as capsaicin not only reduced but also terminated long-lasting effects of ET-1. This was prevented by CGRP-receptor antagonists and was mimicked by exogenous calcitonin gene-related peptide (CGRP. Using 2-photon laser scanning microscopy in vital intact arteries, capsaicin and CGRP, but not ET(A-antagonism, were observed to promote dissociation of pre-existing ET-1/ET(A-receptor complexes. CONCLUSIONS: Irreversible binding and activation of ET(A-receptors by ET-1 (i occur at an antagonist-insensitive site of the receptor and (ii are selectively terminated by endogenously released CGRP. Hence, natural stimuli of sensory-motor nerves that stimulate release of endogenous CGRP can be considered for therapy of diseases involving ET-1.

Increased expression of endothelin ET(B) and angiotensin AT(1) receptors in peripheral resistance arteries of patients with suspected acute coronary syndrome

DEFF Research Database (Denmark)

Dimitrijevic, Ivan; Ekelund, Ulf; Edvinsson, Lars

2009-01-01

of arterial vasoconstrictor endothelin (ET) and angiotensin (AT) receptors. Our aim was to investigate if the arterial expressions of these receptors are changed in patients with suspected but ruled out acute coronary syndrome (ACS). Small subcutaneous arteries (diameter of 100 microm) were surgically removed...... in the regulation of coronary tone and in the development of atherosclerosis, and may be related to increased cardiovascular risk....

Inhibition of CPU0213, a Dual Endothelin Receptor Antagonist, on Apoptosis via Nox4-Dependent ROS in HK-2 Cells

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Qing Li

2016-06-01

Full Text Available Background/Aims: Our previous studies have indicated that a novel endothelin receptor antagonist CPU0213 effectively normalized renal function in diabetic nephropathy. However, the molecular mechanisms mediating the nephroprotective role of CPU0213 remain unknown. Methods and Results: In the present study, we first detected the role of CPU0213 on apoptosis in human renal tubular epithelial cell (HK-2. It was shown that high glucose significantly increased the protein expression of Bax and decreased Bcl-2 protein in HK-2 cells, which was reversed by CPU0213. The percentage of HK-2 cells that showed Annexin V-FITC binding was markedly suppressed by CPU0213, which confirmed the inhibitory role of CPU0213 on apoptosis. Given the regulation of endothelin (ET system to oxidative stress, we determined the role of redox signaling in the regulation of CPU0213 on apoptosis. It was demonstrated that the production of superoxide (O2-. was substantially attenuated by CPU0213 treatment in HK-2 cells. We further found that CPU0213 dramatically inhibited expression of Nox4 protein, which gene silencing mimicked the role of CPU0213 on the apoptosis under high glucose stimulation. We finally examined the role of CPU0213 on ET-1 receptors and found that high glucose-induced protein expression of endothelin A and B receptors was dramatically inhibited by CPU0213. Conclusion: Taken together, these results suggest that this Nox4-dependenet O2- production is critical for the apoptosis of HK-2 cells in high glucose. Endothelin receptor antagonist CPU0213 has an anti-apoptosis role through Nox4-dependent O2-.production, which address the nephroprotective role of CPU0213 in diabetic nephropathy.

Blockade of Endothelin-1 Receptor Type B Ameliorates Glucose Intolerance and Insulin Resistance in a Mouse Model of Obstructive Sleep Apnea

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Jan Polak

2018-05-01

Full Text Available Obstructive sleep apnea (OSA is associated with insulin resistance (IR and glucose intolerance. Elevated endothelin-1 (ET-1 levels have been observed in OSA patients and in mice exposed to intermittent hypoxia (IH. We examined whether pharmacological blockade of type A and type B ET-1 receptors (ETA and ETB would ameliorate glucose intolerance and IR in mice exposed to IH. Subcutaneously implanted pumps delivered BQ-123 (ETA antagonist; 200 nmol/kg/day, BQ-788 (ETB antagonist; 200 nmol/kg/day or vehicle (saline or propyleneglycol [PG] for 14 days in C57BL6/J mice (10/group. During treatment, mice were exposed to IH (decreasing the FiO2 from 20.9% to 6%, 60/h or intermittent air (IA. After IH or IA exposure, insulin (0.5 IU/kg or glucose (1 mg/kg was injected intraperitoneally and plasma glucose determined after injection and area under glucose curve (AUC was calculated. Fourteen-day IH increased fasting glucose levels (122 ± 7 vs. 157 ± 8 mg/dL, PG: 118 ± 6 vs. 139 ± 8; both p < 0.05 and impaired glucose tolerance (AUCglucose: 19,249 ± 1105 vs. 29,124 ± 1444, PG AUCglucose: 18,066 ± 947 vs. 25,135 ± 797; both p < 0.05 in vehicle-treated animals. IH-induced impairments in glucose tolerance were partially ameliorated with BQ-788 treatment (AUCglucose: 21,969 ± 662; p < 0.05. Fourteen-day IH also induced IR (AUCglucose: 7185 ± 401 vs. 8699 ± 401; p < 0.05. Treatment with BQ-788 decreased IR under IA (AUCglucose: 5281 ± 401, p < 0.05 and reduced worsening of IR with IH (AUCglucose: 7302 ± 401, p < 0.05. There was no effect of BQ-123 on IH-induced impairments in glucose tolerance or IR. Our results suggest that ET-1 plays a role in IH-induced impairments in glucose homeostasis.

Imaging evidence for endothelin ETA/ETB receptor heterodimers in isolated rat mesenteric resistance arteries

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Kapsokalyvas, Dimitrios; Schiffers, Paul M H; Maij, Nathan

2014-01-01

AIMS: In engineered cells, endothelin ETA and ETB receptors can heterodimerize. We tested whether this can also be observed in native tissue. MAIN METHODS: Rat mesenteric resistance arteries (rMRA) were maintained in organ culture for 24h to upregulate ETB-mediated contractions in addition to the...

Cooperation of endothelin-1 signaling with melanosomes plays a role in developing and/or maintaining human skin hyperpigmentation

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Daiki Murase

2015-10-01

Full Text Available Skin hyperpigmentation is characterized by increased melanin synthesis and deposition that can cause significant psychosocial and psychological distress. Although several cytokine-receptor signaling cascades contribute to the formation of ultraviolet B-induced cutaneous hyperpigmentation, their possible involvement in other types of skin hyperpigmentation has never been clearly addressed. Since our continuous studies using skin specimens from more than 30 subjects with ethnic skin diversity emphasized a consistent augmentation in the expression of endothelin-1 (ET-1 and its receptor (Endothelin B receptor, ET-B in hyperpigmented lesions, including senile lentigos (SLs, the precise function of ET-1 signaling was investigated in the present study. In line with previous studies, ET-1 significantly induced melanogenesis followed by increases in melanosome transport in melanocytes and in its transfer to keratinocytes while inhibition of ET-B function substantially depressed melanogenic ability in tissue-cultured SLs. Additionally, in agreement with a previous report that the formation of autophagosomes rather than melanosomes is stimulated according to starvation or defective melanosome production, ET-1 was found to remarkably augment the expression of components necessary for early melanosome formation, indicating its counteraction against autophagy-targeting melanosome degradation in melanocytes. Despite the lack of substantial impact of ET-1 on keratinocyte melanogenic functions, the expression of ET-1 was enhanced following melanosome uptake by keratinocytes. Taken together, our data suggest that ET-1 plays a substantial role in the development and/or maintenance of skin hyperpigmentation in reciprocal cooperation with increased melanosome incorporation.

Endothelin receptor antagonists influence cardiovascular morphology in uremic rats.

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Nabokov, A V; Amann, K; Wessels, S; Münter, K; Wagner, J; Ritz, E

1999-02-01

In is generally held that renal failure results in blood pressure (BP)-independent structural changes of the myocardium and the vasculature. The contribution, if any, of endothelin (ET) to these changes has been unknown. We morphometrically studied random samples of the left ventricle myocardium and small intramyocardial arteries in subtotally (5/6) nephrectomized (SNx) male Sprague-Dawley rats treated with either the selective ETA receptor antagonist BMS182874 (30 mg/kg/day) or the nonselective ETA/ETB receptor antagonist Ro46-2005 (30 mg/kg/day) in comparison with either sham-operated rats, untreated SNx, or SNx rats treated with the angiotensin-converting enzyme inhibitor trandolapril (0.1 mg/kg/day). Eight weeks later, systolic BP was lower in trandolapril-treated SNx compared with untreated SNx animals. No decrease in BP was seen following either ET receptor antagonist at the dose used. A significantly increased volume density of the myocardial interstitium was found in untreated SNx rats as compared with sham-operated controls. Such interstitial expansion was prevented by trandolapril and either ET receptor antagonist. SNx caused a substantial increase in the wall thickness of small intramyocardial arteries. The increase was prevented by trandolapril or BMS182874 treatment. The arteriolar wall:lumen ratio was significantly lower in all treated groups when compared with untreated SNx. In contrast, only trandolapril, but not the ET receptor antagonists, attenuated thickening of the aortic media in SNx animals. The ETA-selective and ETA/ETB-nonselective receptor antagonists appear to prevent development of myocardial fibrosis and structural changes of small intramyocardial arteries in experimental chronic renal failure. This effect is independent of systemic BP.

Gestational hypoxia induces preeclampsia-like symptoms via heightened endothelin-1 signaling in pregnant rats.

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Zhou, Jianjun; Xiao, Daliao; Hu, Yali; Wang, Zhiqun; Paradis, Alexandra; Mata-Greenwood, Eugenia; Zhang, Lubo

2013-09-01

Preeclampsia is a life-threatening pregnancy disorder. However, its pathogenesis remains unclear. We tested the hypothesis that gestational hypoxia induces preeclampsia-like symptoms via heightened endothelin-1 (ET-1) signaling. Time-dated pregnant and nonpregnant rats were divided into normoxic and hypoxic (10.5% O2 from the gestational day 6-21) groups. Chronic hypoxia had no significant effect on blood pressure or proteinuria in nonpregnant rats but significantly increased blood pressure on day 12 (systolic blood pressure, 111.7 ± 6.1 versus 138.5 ± 3.5 mm Hg; P=0.004) and day 20 (systolic blood pressure, 103.4 ± 4.6 versus 125.1 ± 6.1 mm Hg; P=0.02) in pregnant rats and urine protein (μg/μL)/creatinine (nmol/μL) ratio on day 20 (0.10 ± 0.01 versus 0.20 ± 0.04; P=0.04), as compared with the normoxic control group. This was accompanied with asymmetrical fetal growth restriction. Hypoxia resulted in impaired trophoblast invasion and uteroplacental vascular remodeling. In addition, plasma ET-1 levels, as well as the abundance of prepro-ET-1 mRNA, ET-1 type A receptor and angiotensin II type 1 receptor protein in the kidney and placenta were significantly increased in the chronic hypoxic group, as compared with the control animals. Treatment with the ET-1 type A receptor antagonist, BQ123, during the course of hypoxia exposure significantly attenuated the hypoxia-induced hypertension and other preeclampsia-like features. The results demonstrate that chronic hypoxia during gestation induces preeclamptic symptoms in pregnant rats via heightened ET-1 and ET-1 type A receptor-mediated signaling, providing a molecular mechanism linking gestational hypoxia and increased risk of preeclampsia.

Melatonin inhibits endothelin-1 and induces endothelial nitric oxide ...

African Journals Online (AJOL)

Although, I/R augmented the endothelin-1 (ET-1) gene expression and the level of big endothelin-1 (big ET-1) in liver tissue, melatonin attenuated these increases. Conversely, non-significant decrease in endothelial nitric oxide synthase (eNOS) mRNA expression in I/R group was significantly elevated by melatonin in ...

Polymorphisms of the endothelin-A and -B receptor genes in relation to blood pressure and myocardial infarction: the Etude Cas-Témoins sur l'Infarctus du Myocarde (ECTIM) Study.

Science.gov (United States)

Nicaud, V; Poirier, O; Behague, I; Herrmann, S M; Mallet, C; Troesch, A; Bouyer, J; Evans, A; Luc, G; Ruidavets, J B; Arveiler, D; Bingham, A; Tiret, L; Cambien, F

1999-03-01

Endothelin-1 is a potent vasoconstrictor that has also mitogenic properties, stimulating the synthesis and secretion of several vasoactive molecules. There is much evidence to suggest that endothelin-1 might be involved in the pathogenesis of hypertension, atherosclerosis, and ischemic heart disease. Endothelin-1 exerts its effects through at least two receptors, ET(A) and ET(B), which are encoded by different genes and have separate tissue distributions and biologic properties. The objective of this study was to identify polymorphisms of the ET(A) and ET(B) receptor genes and to study their association with myocardial infarction (MI) and blood pressure. The coding regions and 1.3 kb upstream of the ET(A) and ET(B) receptor genes were explored by polymerase chain reaction/single strand conformation polymorphism. Six polymorphisms were found in the ET(A) receptor gene and three in the ET(B) receptor gene. Most of these polymorphisms were frequent. Associations between the detected polymorphisms, blood pressure, and MI were examined in the ECTIM study, a multicenter study comparing 652 patients having survived an MI and 773 controls from Belfast (Northern Ireland) and France. Alleles at the different polymorphic sites were similarly distributed in patients with MI and controls. Allele frequencies were similar in both countries, except for the ET(A)/-231 G allele, which appeared more frequently in France than in Belfast (P < .01). The mean systolic and diastolic blood pressure levels did not significantly differ between genotypes. However, a C/T substitution located in the nontranslated part of exon 8 of the ET(A) receptor gene (ET(A)/EX8nt1363) was associated with pulse pressure (P < .005). These results do not support an involvement of the endothelin receptor genes in a predisposition to MI or the determination of blood pressure levels, but suggest that a polymorphism of the ET(A) receptor gene might influence the pulse pressure. This result will have to be

Endothelin-1-induced focal cerebral ischemia in the growth hormone/IGF-1 deficient Lewis Dwarf rat.

Science.gov (United States)

Yan, Han; Mitschelen, Matthew; Toth, Peter; Ashpole, Nicole M; Farley, Julie A; Hodges, Erik L; Warrington, Junie P; Han, Song; Fung, Kar-Ming; Csiszar, Anna; Ungvari, Zoltan; Sonntag, William E

2014-11-01

Aging is a major risk factor for cerebrovascular disease. Growth hormone (GH) and its anabolic mediator, insulin-like growth factor (IGF)-1, decrease with advancing age and this decline has been shown to promote vascular dysfunction. In addition, lower GH/IGF-1 levels are associated with higher stroke mortality in humans. These results suggest that decreased GH/IGF-1 level is an important factor in increased risk of cerebrovascular diseases. This study was designed to assess whether GH/IGF-1-deficiency influences the outcome of cerebral ischemia. We found that endothelin-1-induced middle cerebral artery occlusion resulted in a modest but nonsignificant decrease in cerebral infarct size in GH/IGF-1 deficient dw/dw rats compared with control heterozygous littermates and dw/dw rats with early-life GH treatment. Expression of endothelin receptors and endothelin-1-induced constriction of the middle cerebral arteries were similar in the three experimental groups. Interestingly, dw/dw rats exhibited reduced brain edema and less astrocytic infiltration compared with their heterozygous littermates and this effect was reversed by GH-treatment. Because reactive astrocytes are critical for the regulation of poststroke inflammatory processes, maintenance of the blood-brain barrier and neural repair, further studies are warranted to determine the long-term functional consequences of decreased astrocytic activation in GH/IGF-1 deficient animals after cerebral ischemia. Published by Oxford University Press on behalf of the Gerontological Society of America 2014.

Vascular mechanism of action of endothelin-1: Effect of Ca2+ antagonists

International Nuclear Information System (INIS)

Chabrier, P.E.; Auguet, M.; Roubert, P.; Lonchampt, M.O.; Gillard, V.; Guillon, J.M.; Delaflotte, S.; Braquet, P.

1989-01-01

The vasoconstrictive properties of the endothelium-derived peptide, endothelin-1 (ET-1), were investigated on rat isolated aorta and on cultured rat aortic smooth muscle cells. In rat isolated aorta, endothelin-1 induced a slow and sustained contraction in a Ca2+-free medium; after calcium readmission, an additional sustained contraction was elicited. In vascular smooth muscle cells, endothelin-1 provoked a dose-dependent Ca2+ influx that was not inhibited by calcium entry blockers (nifedipine, D 600, or diltiazem). In these cells, [ 125 I]-endothelin-1 bound to a specific, saturable, and high affinity recognition site (Kd about 10(-9) M and Bmax = 52 +/- 2 fmol/10(6) cells). The binding was not reversible and not affected by calcium antagonists. These data do not support the hypothesis that endothelin-1 acts as an endogenous agonist of the voltage-dependent Ca2+ channels. The action of endothelin-1 can be separated into two components: one dependent on Ca2+ influx but insensitive to calcium antagonists and another independent of extracellular Ca2+. The irreversible binding of endothelin-1 may reflect an internalization of the ligand inside the cell membrane, leading to multiple contractile events

Smooth Muscle Endothelin B Receptors Regulate Blood Pressure but Not Vascular Function or Neointimal Remodeling.

Science.gov (United States)

Miller, Eileen; Czopek, Alicja; Duthie, Karolina M; Kirkby, Nicholas S; van de Putte, Elisabeth E Fransen; Christen, Sibylle; Kimmitt, Robert A; Moorhouse, Rebecca; Castellan, Raphael F P; Kotelevtsev, Yuri V; Kuc, Rhoda E; Davenport, Anthony P; Dhaun, Neeraj; Webb, David J; Hadoke, Patrick W F

2017-02-01

The role of smooth muscle endothelin B (ET B ) receptors in regulating vascular function, blood pressure (BP), and neointimal remodeling has not been established. Selective knockout mice were generated to address the hypothesis that loss of smooth muscle ET B receptors would reduce BP, alter vascular contractility, and inhibit neointimal remodeling. ET B receptors were selectively deleted from smooth muscle by crossing floxed ET B mice with those expressing cre-recombinase controlled by the transgelin promoter. Functional consequences of ET B deletion were assessed using myography. BP was measured by telemetry, and neointimal lesion formation induced by femoral artery injury. Lesion size and composition (day 28) were analyzed using optical projection tomography, histology, and immunohistochemistry. Selective deletion of ET B was confirmed by genotyping, autoradiography, polymerase chain reaction, and immunohistochemistry. ET B -mediated contraction was reduced in trachea, but abolished from mesenteric veins, of knockout mice. Induction of ET B -mediated contraction in mesenteric arteries was also abolished in these mice. Femoral artery function was unaltered, and baseline BP modestly elevated in smooth muscle ET B knockout compared with controls (+4.2±0.2 mm Hg; P<0.0001), but salt-induced and ET B blockade-mediated hypertension were unaltered. Circulating endothelin-1 was not altered in knockout mice. ET B -mediated contraction was not induced in femoral arteries by incubation in culture medium or lesion formation, and lesion size was not altered in smooth muscle ET B knockout mice. In the absence of other pathology, ET B receptors in vascular smooth muscle make a small but significant contribution to ET B -dependent regulation of BP. These ET B receptors have no effect on vascular contraction or neointimal remodeling. © 2016 The Authors.

Expression profile of endothelin receptors (ETA and ETB) and microRNAs-155 and -199 in the corpus cavernosum of rats submitted to chronic alcoholism and diabetes mellitus.

Science.gov (United States)

Gonçalves, F Z; Lizarte Neto, F S; Novais, P C; Gattas, D; Lourenço, L G; de Carvalho, C A M; Tirapelli, D P C; Molina, C A F; Tirapelli, L F; Tucci, S

2018-03-01

Recent evidence shows that chronic ethanol consumption increases endothelin (ET)-1 induced sustained contraction of trabecular smooth muscle cells of the corpora cavernosa in corpus cavernosum of rats by a mechanism that involves increased expression of ETA and ETB receptors. Our goal was to evaluate the effects of alcohol and diabetes and their relationship to miRNA-155, miRNA-199 and endothelin receptors in the corpus cavernosum and blood of rats submitted to the experimental model of diabetes mellitus and chronic alcoholism. Forty-eight male Wistar rats were divided into four groups: control (C), alcoholic (A), diabetic (D), and alcoholic-diabetic (AD). Samples of the corpus cavernosum were prepared to study the protein expression of endothelin receptors by immunohistochemistry and expression of miRNAs-155 and -199 in serum and the cavernous tissue. Immunostaining for endothelin receptors was markedly higher in the A, D, and AD groups than in the C group. Moreover, a significant hypoexpression of the miRNA-199 in the corpus cavernosum tissue from the AD group was observed, compared to the C group. When analyzing the microRNA profile in blood, a significant hypoexpression of miRNA-155 in the AD group was observed compared to the C group. The miRNA-199 analysis demonstrated significant hypoexpression in D and AD groups compared to the C group. Our findings in corpus cavernosum showed downregulated miRNA-155 and miRNA-199 levels associated with upregulated protein expression and unaltered mRNA expression of ET receptors suggesting decreased ET receptor turnover, which can contribute to erectile dysfunction in diabetic rats exposed to high alcohol levels.

Expression profile of endothelin receptors (ETA and ETB and microRNAs-155 and -199 in the corpus cavernosum of rats submitted to chronic alcoholism and diabetes mellitus

Directory of Open Access Journals (Sweden)

F.Z. Gonçalves

2018-03-01

Full Text Available Recent evidence shows that chronic ethanol consumption increases endothelin (ET-1 induced sustained contraction of trabecular smooth muscle cells of the corpora cavernosa in corpus cavernosum of rats by a mechanism that involves increased expression of ETA and ETB receptors. Our goal was to evaluate the effects of alcohol and diabetes and their relationship to miRNA-155, miRNA-199 and endothelin receptors in the corpus cavernosum and blood of rats submitted to the experimental model of diabetes mellitus and chronic alcoholism. Forty-eight male Wistar rats were divided into four groups: control (C, alcoholic (A, diabetic (D, and alcoholic-diabetic (AD. Samples of the corpus cavernosum were prepared to study the protein expression of endothelin receptors by immunohistochemistry and expression of miRNAs-155 and -199 in serum and the cavernous tissue. Immunostaining for endothelin receptors was markedly higher in the A, D, and AD groups than in the C group. Moreover, a significant hypoexpression of the miRNA-199 in the corpus cavernosum tissue from the AD group was observed, compared to the C group. When analyzing the microRNA profile in blood, a significant hypoexpression of miRNA-155 in the AD group was observed compared to the C group. The miRNA-199 analysis demonstrated significant hypoexpression in D and AD groups compared to the C group. Our findings in corpus cavernosum showed downregulated miRNA-155 and miRNA-199 levels associated with upregulated protein expression and unaltered mRNA expression of ET receptors suggesting decreased ET receptor turnover, which can contribute to erectile dysfunction in diabetic rats exposed to high alcohol levels.

Plasma Interleukin-8 and Endothelin-1 in Symptomatic and Asymptomatic Children

International Nuclear Information System (INIS)

Radwan, Z.; El-Abiad, N.; Soliman, M. S.; Ali, A.I.; Ali, G.S.

2004-01-01

This study was designed to evaluate the extent to which IL-8 and endothelin-1 are involved in the development of acute exacerbation of atopic asthma. Two asthmatic groups, each of 20 patients were studied, the asymptomatic group where patients were free of symptoms and the symptomatic group where patients were suffering from acute exacerbation of their asthma. Both of asthmatic groups were subclassified into mild and moderate subgroups, each of 10 patients according to the asthma severity. All subjects were subjected to chest X-ray and peak expiratory flow rate (PEFR) recording for sub-classification of patients, skin prick testing using common allergens (patients only) for the identification of atopic asthmatic patients and laboratory investigations including complete blood count (CBC), absolute eosi-nophil count (AEC), urine and stool exam-ination, total serum 1 gE level, plasma inter-leukin-8 (IL-8) level and plasma endothelin-1 (ET-1) level. The data obtained revealed non-significant differences between the studied groups as regards AEC, while serum total 1 gE of the asthmatic groups showed highly significant elevations in comparison to control group. Also, There were highly significant elevations in plasma endothelin-1 and plasma IL-8 levels of the symptomatic asthmatic subgroups in comparison to control group and asymptomatic asthmatic subgroups in comparison to control group and asymptomatic asthmatic subgroups. In conclusion: although it is clear now that IL-8 and ET-1 are involved in acute exacerbation of atopic asthmatic patients, a causal link between those mediators and development of the exacerbation has not been definitively established. Surely, those mediators, their receptors, synthesis and degradation pathways offer potentially important therapeutic targets

Endothelin receptor-specific control of endoplasmic reticulum stress and apoptosis in the kidney.

Science.gov (United States)

De Miguel, Carmen; Hamrick, William C; Hobbs, Janet L; Pollock, David M; Carmines, Pamela K; Pollock, Jennifer S

2017-02-23

Endothelin-1 (ET-1) promotes renal damage during cardiovascular disease; yet, the molecular mechanisms involved remain unknown. Endoplasmic reticulum (ER) stress, triggered by unfolded protein accumulation in the ER, contributes to apoptosis and organ injury. These studies aimed to determine whether the ET-1 system promotes renal ER stress development in response to tunicamycin. ET B deficient (ET B def) or transgenic control (TG-con) rats were used in the presence or absence of ET A receptor antagonism. Tunicamycin treatment similarly increased cortical ER stress markers in both rat genotypes; however, only ET B def rats showed a 14-24 fold increase from baseline for medullary GRP78, sXBP-1, and CHOP. Pre-treatment of TG-con rats with the ET A blocker ABT-627 for 1 week prior to tunicamycin injection significantly reduced the ER stress response in cortex and medulla, and also inhibited renal apoptosis. Pre-treatment with ABT-627 failed to decrease renal ER stress and apoptosis in ET B def rats. In conclusion, the ET-1 system is important for the development of tunicamycin-induced renal ER stress and apoptosis. ET A receptor activation induces renal ER stress genes and apoptosis, while functional activation of the ET B receptor has protective effects. These results highlight targeting the ET A receptor as a therapeutic approach against ER stress-induced kidney injury.

Affinity and selectivity of PD156707, a novel nonpeptide endothelin antagonist, for human ET(A) and ET(B) receptors.

Science.gov (United States)

Maguire, J J; Kuc, R E; Davenport, A P

1997-02-01

We have determined the affinity and selectivity of a new nonpeptide antagonist PD156707 (sodium 2-benzo(1,3ioxol-5-yl-4-(4-methoxy-pheny l)-4-oxo-3-(3,4,5-trime tho xybenzyl)-but-2-enoate) for human endothelin (ET)(A) and ET(B) receptors. In human coronary artery and saphenous vein the affinity of the ET(A) receptor for PD156707 was 0.15 +/- 0.06 nM and 0.5 +/- 0.13 nM, respectively. Competition experiments in human left ventricle and kidney revealed that PD156707 had 1,000- to 15,000-fold selectivity for the ET(A) receptor over the ET(B) receptor. This selectivity was confirmed autoradiographically. In human coronary artery, mammary artery and saphenous vein PD156707 (3-300 nM) potently antagonized the vasoconstrictor responses to ET-1. The pA2 values estimated from the Gaddum-Schild equation were 8.07 +/- 0.09, 8.45 +/- 0.11 and 8.70 +/- 0.13, respectively. The concentration-response curves to ET-1 were shifted to the right in parallel fashion, without reduction of the maximum response. However, the regression lines fitted to the resulting Schild data deviated significantly from one. PD156707 appeared to be a more effective antagonist at lower concentrations than at the higher ones. It is possible that PD156707, a sodium salt, was reverting to a less soluble form which results in underestimation of its potency. These data show that PD156707 is a potent and selective antagonist at human ET(A) receptors and will be useful in clarifying the role of the endothelin peptides in human cardiovascular disease.

Activation of either the ETA or the ETB receptors is involved in the development of electrographic seizures following intrahippocampal infusion of the endothelin-1 in immature rats

Czech Academy of Sciences Publication Activity Database

Tsenov, Grygoriy; Vondráková, Kateřina; Otáhal, Jakub; Burchfiel, J.; Kubová, Hana

2015-01-01

Roč. 265, Mar 2015 (2015), s. 40-47 ISSN 0014-4886 R&D Projects: GA ČR(CZ) GPP304/11/P386; GA ČR(CZ) GBP304/12/G069; GA ČR(CZ) GA14-20613S Institutional support: RVO:67985823 Keywords : focal ischemia * endothelin-1 * cerebral blood flow * oxygen saturation * seizures * hippocampus * immature rat * ET receptors Subject RIV: FH - Neurology Impact factor: 4.657, year: 2015

Stretch induced endothelin-1 secretion by adult rat astrocytes involves calcium influx via stretch-activated ion channels (SACs)

International Nuclear Information System (INIS)

Ostrow, Lyle W.; Suchyna, Thomas M.; Sachs, Frederick

2011-01-01

Highlights: → Endothelin-1 expression by adult rat astrocytes correlates with cell proliferation. → Stretch-induced ET-1 is inhibited by GsMtx-4, a specific inhibitor of Ca 2+ permeant SACs. → The less specific SAC inhibitor streptomycin also inhibits ET-1 secretion. → Stretch-induced ET-1 production depends on a calcium influx. → SAC pharmacology may provide a new class of therapeutic agents for CNS pathology. -- Abstract: The expression of endothelins (ETs) and ET-receptors is often upregulated in brain pathology. ET-1, a potent vasoconstrictor, also inhibits the expression of astrocyte glutamate transporters and is mitogenic for astrocytes, glioma cells, neurons, and brain capillary endothelia. We have previously shown that mechanical stress stimulates ET-1 production by adult rat astrocytes. We now show in adult astrocytes that ET-1 production is driven by calcium influx through stretch-activated ion channels (SACs) and the ET-1 production correlates with cell proliferation. Mechanical stimulation using biaxial stretch ( 2+ threshold. This coupling of mechanical stress to the astrocyte endothelin system through SACs has treatment implications, since all pathology deforms the surrounding parenchyma.

Gene expression of endothelin receptors in replaced rheumatic mitral stenotic valves Expressão gênica de receptores de endotelina em valvas mitrais reumáticas estenóticas substituídas

Directory of Open Access Journals (Sweden)

Sydney Correia Leão

2012-12-01

Full Text Available OBJECTIVES: Rheumatic fever is a highly prevalent disease in Brazil, and it poses a major public health problem. It is the leading cause of acquired heart disease in childhood and adolescence. The aim of this study was to evaluate the gene expression of ET-3 and its receptors, in replaced rheumatic mitral valves. METHODS: We studied the gene expression of endothelin-3 (ET-3 and its receptors, endothelin receptor A and endothelin receptor B (ETr-A and ETr-B, in the rheumatic mitral valves of 17 patients who underwent valve replacement surgery. The samples also underwent a histological analysis. RESULTS: Our data showed that almost all patients, regardless of individual characteristics such as gender or age, expressed the endothelin receptor genes, but did not express the genes for ET-3. In quantitative analysis, the ETr-A/GAPDH mean ratio was 33.04 ± 18.09%; while the ETr-B/GAPDH mean ratio was 114.58 ± 42.30%. Regarding histopathological individual features, the frequency of fibrosis is 100%, 88.23% of mononuclear infiltrate, 52.94% of neovascularization, 58.82% of calcification and absence of ossification. CONCLUSION: The presence of receptors ETr-A and ETr-B in rheumatic mitral valves suggests its interaction with the system of circulating endothelins, particularly ETr-B (known for acting in the removal of excess endothelin detected in a greater proportion, which could explain the lack of expression of endothelin in rheumatic mitral valve, process to be elucidated.OBJETIVOS: A febre reumática é uma doença altamente prevalente no Brasil, e representa um importante problema de saúde pública. É a principal causa de cardiopatia adquirida na infância e adolescência. O objetivo deste estudo foi avaliar a expressão gênica de ET-3 e seus receptores, em valvas mitrais reumáticas substituídas. Métodos: Estudamos a expressão gênica de endotelina-3 (ET-3 e de seus receptores, receptor da endotelina A e receptor da endotelina B (ETr-A e

Different pressor and bronchoconstrictor properties of human big-endothelin-1, 2 (1-38) and 3 in ketamine/xylazine-anaesthetized guinea-pigs.

OpenAIRE

Gratton, J P; Rae, G A; Claing, A; Télémaque, S; D'Orléans-Juste, P

1995-01-01

1. In the present study, the precursors of endothelin-1, endothelin-2 and endothelin-3 were tested for their pressor and bronchoconstrictor properties in the anaesthetized guinea-pig. In addition, the effects of big-endothelin-1 and endothelin-1 were assessed under urethane or ketamine/xylazine anaesthesia. 2. When compared to ketamine/xylazine, urethane markedly depressed the pressor and bronchoconstrictor properties of endothelin-1 and big-endothelin-1. 3. Under ketamine/xylazine anaesthesi...

Overexpression of endothelin B receptor in glioblastoma: a prognostic marker and therapeutic target?

KAUST Repository

Vasaikar, Suhas

2018-02-06

BackgroundGlioblastoma (GBM) is the most common malignant brain tumor with median survival of 12-15 months. Owing to uncertainty in clinical outcome, additional prognostic marker(s) apart from existing markers are needed. Since overexpression of endothelin B receptor (ETBR) has been demonstrated in gliomas, we aimed to test whether ETBR is a useful prognostic marker in GBM and examine if the clinically available endothelin receptor antagonists (ERA) could be useful in the disease treatment.MethodsData from The Cancer Genome Atlas and the Gene Expression Omnibus database were analyzed to assess ETBR expression. For survival analysis, glioblastoma samples from 25 Swedish patients were immunostained for ETBR, and the findings were correlated with clinical history. The druggability of ETBR was assessed by protein-protein interaction network analysis. ERAs were analyzed for toxicity in in vitro assays with GBM and breast cancer cells.ResultsBy bioinformatics analysis, ETBR was found to be upregulated in glioblastoma patients, and its expression levels were correlated with reduced survival. ETBR interacts with key proteins involved in cancer pathogenesis, suggesting it as a druggable target. In vitro viability assays showed that ERAs may hold promise to treat glioblastoma and breast cancer.ConclusionsETBR is overexpressed in glioblastoma and other cancers and may be a prognostic marker in glioblastoma. ERAs may be useful for treating cancer patients.

Endothelin-like action of Pausinystalia yohimbe aqueous extract on vascular and renal regional hemodynamics in Sprague Dawley rats.

Science.gov (United States)

Ajayi, A A; Newaz, M; Hercule, H; Saleh, M; Bode, C O; Oyekan, A O

2003-12-01

The bark of the African tree Pausinystalia yohimbe has been used as a food additive with aphrodisiac and penile erection enhancing properties. The effect of an aqueous extract of P. yohimbe (CCD-X) on renal circulation was assessed in order to test the hypothesis that it possesses additional effects on nitric oxide production and/or endothelin-1 (ET-1)-like actions. In vivo studies with CCD-X in Sprague Dawley rats demonstrated a dose-dependent (1-1000 ng/kg) increase in mean blood pressure (p < 0.001) and an increase in medullary blood flow (MBF) (p < 0.001). Both the pressor action and renal medullary vasodilation were blocked by endothelinA (ETA) receptor antagonist BMS182874 and endothelinB (ETB) receptor antagonist BQ788 in combination. L-Nomega-nitro-l-arginine methyl ester (L-NAME; 10 mg/kg) also inhibited the increase in MBF induced by CCD-X. In vitro studies in isolated perfused kidney and in pressurized renal microvessels confirmed the dose-dependent vasoconstrictor action of this extract. ETA receptor antagonist BQ610 and ETB receptor antagonist BQ788 separately and significantly attenuated the renal vasoconstrictor actions of the extract (p < 0.001 ANOVA). These preliminary observations indicate that, in addition to the alpha-adrenergic antagonist actions that characterize yohimbine, CCD-X possesses endothelin-like actions and affects nitric oxide (NO) production in renal circulation. These findings suggest a strong possibility of post-receptor cross-talk between alpha2-adrenoceptors and endothelin, as well as a direct effect of alpha2-adrenoceptors on renal NO production. (c) 2003 Prous Science

Vascular endothelial cells mediate mechanical stimulation-induced enhancement of endothelin hyperalgesia via activation of P2X2/3 receptors on nociceptors.

Science.gov (United States)

Joseph, Elizabeth K; Green, Paul G; Bogen, Oliver; Alvarez, Pedro; Levine, Jon D

2013-02-13

Endothelin-1 (ET-1) is unique among a broad range of hyperalgesic agents in that it induces hyperalgesia in rats that is markedly enhanced by repeated mechanical stimulation at the site of administration. Antagonists to the ET-1 receptors, ET(A) and ET(B), attenuated both initial as well as stimulation-induced enhancement of hyperalgesia (SIEH) by endothelin. However, administering antisense oligodeoxynucleotide to attenuate ET(A) receptor expression on nociceptors attenuated ET-1 hyperalgesia but had no effect on SIEH, suggesting that this is mediated via a non-neuronal cell. Because vascular endothelial cells are both stretch sensitive and express ET(A) and ET(B) receptors, we tested the hypothesis that SIEH is dependent on endothelial cells by impairing vascular endothelial function with octoxynol-9 administration; this procedure eliminated SIEH without attenuating ET-1 hyperalgesia. A role for protein kinase Cε (PKCε), a second messenger implicated in the induction and maintenance of chronic pain, was explored. Intrathecal antisense for PKCε did not inhibit either ET-1 hyperalgesia or SIEH, suggesting no role for neuronal PKCε; however, administration of a PKCε inhibitor at the site of testing selectively attenuated SIEH. Compatible with endothelial cells releasing ATP in response to mechanical stimulation, P2X(2/3) receptor antagonists eliminated SIEH. The endothelium also appears to contribute to hyperalgesia in two ergonomic pain models (eccentric exercise and hindlimb vibration) and in a model of endometriosis. We propose that SIEH is produced by an effect of ET-1 on vascular endothelial cells, sensitizing its release of ATP in response to mechanical stimulation; ATP in turn acts at the nociceptor P2X(2/3) receptor.

Characterizing the role of endothelin-1 in the progression of cardiac hypertrophy in aryl hydrocarbon receptor (AhR) null mice

International Nuclear Information System (INIS)

Lund, Amie K.; Goens, M. Beth; Nunez, Bethany A.; Walker, Mary K.

2006-01-01

The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor characterized to play a role in detection and adaptation to environmental stimuli. Genetic deletion of AhR results in hypertension, and cardiac hypertrophy and fibrosis, associated with elevated plasma angiotensin II (Ang II) and endothelin-1 (ET-1), thus AhR appears to contribute to cardiovascular homeostasis. In these studies, we tested the hypothesis that ET-1 mediates cardiovascular pathology in AhR null mice via ET A receptor activation. First, we determine the time courses of cardiac hypertrophy, and of plasma and tissue ET-1 expression in AhR wildtype and null mice. AhR null mice exhibited increases in heart-to-body weight ratio and age-related expression of cardiac hypertrophy markers, β-myosin heavy chain (β-MHC), and atrial natriuretic factor (ANF), which were significant at 2 months. Similarly, plasma and tissue ET-1 expression was significantly elevated at 2 months and increased further with age. Second, AhR null mice were treated with ET A receptor antagonist, BQ-123 (100 nmol/kg/day), for 7, 28, or 58 days and blood pressure, cardiac fibrosis, and cardiac hypertrophy assessed, respectively. BQ-123 for 7 days significantly reduced mean arterial pressure in conscious, catheterized mice. BQ-123 for 28 days significantly reduced the histological appearance of cardiac fibrosis. Treatment for 58 days significantly reduced cardiac mass, assessed by heart weight, echocardiography, and β-MHC and ANF expression; and reduced cardiac fibrosis as determined by osteopontin and collagen I mRNA expression. These findings establish ET-1 and the ET A receptor as primary determinants of hypertension and cardiac pathology in AhR null mice

Sandwich-type enzyme immunoassay for big endothelin-I in plasma: concentrations in healthy human subjects unaffected by sex or posture.

Science.gov (United States)

Aubin, P; Le Brun, G; Moldovan, F; Villette, J M; Créminon, C; Dumas, J; Homyrda, L; Soliman, H; Azizi, M; Fiet, J

1997-01-01

A sandwich-type enzyme immunoassay has been developed for measuring human big endothelin-1 (big ET-1) in human plasma and supernatant fluids from human cell cultures. Big ET-1 is the precursor of endothelin 1 (ET-1), the most potent vasoconstrictor known. A rabbit antibody raised against the big ET-1 COOH-terminus fragment was used as an immobilized antibody (anti-P16). The Fab' fragment of a monoclonal antibody (1B3) raised against the ET-1 loop fragment was used as the enzyme-labeled antibody, after being coupled to acetylcholinesterase. The lowest detectable value in the assay was 1.2 pg/mL (0.12 pg/well). The assay was highly specific for big ET-1, demonstrating no cross-reactivity with ET-1, big endothelin-2 (big ET-2), and big endothelin-3 (big ET-3). We used this assay to evaluate the effect of two different postural positions (supine and standing) on plasma big ET-1 concentrations in 11 male and 11 female healthy subjects. Data analysis revealed that neither sex nor body position influenced plasma big ET-1 concentrations. This assay should thus permit the detection of possible variations in plasma concentrations of big ET-1 in certain pathologies and, in association with ET-1 assay, make possible in vitro study of endothelin-converting enzyme activity in cell models. Such studies could clarify the physiological and clinical roles of this family of peptides.

Endothelin-A-receptor antagonism with atrasentan exhibits limited activity on the KU-19-19 bladder cancer cell line in a mouse model.

Science.gov (United States)

Herrmann, Edwin; Tiemann, Arne; Eltze, Elke; Bolenz, Christian; Bremer, Christoph; Persigehl, Thorsten; Hertle, Lothar; Wülfing, Christian

2009-10-01

The endothelin axis consists of endothelin-1 (ET-1) and its two receptors, ET(A)- and ET(B)-receptor (ET(A)-R and ET(B)-R). In several tumor entities, the ET(A)-R plays a significant role as a drug target. In our study, we investigated whether inhibition of ET(A)-R with atrasentan leads to an antitumor effect in urinary bladder carcinoma as well. Twenty nude mice with thymic aplasia were subcutaneously administered 2 x 10(6) KU-19-19 bladder cancer cells in the right flank. Starting on the 22nd day after the injection, ten animals were treated with atrasentan (2.5 mg/kg BW intraperitoneally), and another ten animals were treated with placebo. During treatment, absolute tumor growth and relative growth rate over time were determined. After the end of treatment, the mitosis and necrosis rates, microvessel density, and receptor density in the tumor tissue were analyzed by immunohistochemistry. In addition, the expression intensities of ET-1, ET(A)-R, and ET(B)-R were evaluated semiquantitatively and compared between the groups. No significant differences between the active-treatment and placebo groups were detected, either with respect to absolute tumor growth (P = 0.333) or mitosis rate (P = 0.217). In the analysis of the necrosis rate and receptor density for ET(A)-R, a trend toward higher values in the active-treatment group (mean necrosis rate = 63.67%, receptor density: 1.417) than in the placebo group (mean necrosis rate = 46.25%, receptor density: 1.270) was found; however, neither difference was statistically significant (P = 0.08 and 0.219, respectively). ET(A)-R blockade with atrasentan in a bladder cancer xenograft model shows no significant antitumor effect.

Endothelin-1 and endothelin-3 in cirrhosis: relations to systemic and splanchnic haemodynamics

DEFF Research Database (Denmark)

Møller, Søren; Gülberg, V; Henriksen, Jens Henrik

1995-01-01

correlated with the hepatic venous pressure gradient (r = 0.61, p r = 0.35, p r = -0.31, p r = -0.41, p r = -0.56, p ... correlated to the cardiac output in the group with cirrhosis (r = 0.35, p ....002). The same pattern was found in arterial endothelin-3. Hepatic venous endothelin-3 correlated significantly with central and arterial blood volume (r = 0.56, p

High endothelin-converting enzyme-1 expression independently predicts poor survival of patients with esophageal squamous cell carcinoma.

Science.gov (United States)

Wu, Ching-Fang; Lee, Ching-Tai; Kuo, Yao-Hung; Chen, Tzu-Haw; Chang, Chi-Yang; Chang, I-Wei; Wang, Wen-Lun

2017-09-01

Patients with esophageal squamous cell carcinoma have poor survival and high recurrence rate, thus an effective prognostic biomarker is needed. Endothelin-converting enzyme-1 is responsible for biosynthesis of endothelin-1, which promotes growth and invasion of human cancers. The role of endothelin-converting enzyme-1 in esophageal squamous cell carcinoma is still unknown. Therefore, this study investigated the significance of endothelin-converting enzyme-1 expression in esophageal squamous cell carcinoma clinically. We enrolled patients with esophageal squamous cell carcinoma who provided pretreated tumor tissues. Tumor endothelin-converting enzyme-1 expression was evaluated by immunohistochemistry and was defined as either low or high expression. Then we evaluated whether tumor endothelin-converting enzyme-1 expression had any association with clinicopathological findings or predicted survival of patients with esophageal squamous cell carcinoma. Overall, 54 of 99 patients with esophageal squamous cell carcinoma had high tumor endothelin-converting enzyme-1 expression, which was significantly associated with lymph node metastasis ( p = 0.04). In addition, tumor endothelin-converting enzyme-1 expression independently predicted survival of patients with esophageal squamous cell carcinoma, and the 5-year survival was poorer in patients with high tumor endothelin-converting enzyme-1 expression ( p = 0.016). Among patients with locally advanced and potentially resectable esophageal squamous cell carcinoma (stage II and III), 5-year survival was poorer with high tumor endothelin-converting enzyme-1 expression ( p = 0.003). High tumor endothelin-converting enzyme-1 expression also significantly predicted poorer survival of patients in this population. In patients with esophageal squamous cell carcinoma, high tumor endothelin-converting enzyme-1 expression might indicate high tumor invasive property. Therefore, tumor endothelin-converting enzyme-1 expression

Vasoactive receptors in abdominal blood vessels of the dogfish shark, Squalus acanthias.

Science.gov (United States)

Evans, D H

2001-01-01

Previous studies have demonstrated that the ventral aorta of the dogfish shark, Squalus acanthias, responds to a variety of cell-signaling agents. To investigate the generality of vasoactive receptors in the shark vasculature, in particular a conductance artery (anterior mesenteric) and vein (posterior intestinal), I measured the effect of acetylcholine, endothelin, nitric oxide, natriuretic peptides, and prostaglandins on tension in isolated rings from these vessels. Both vessels responded to these agents, and responses to receptor-specific ligands for endothelin and natriuretic peptide receptors suggest that B-type endothelin receptors are expressed in both vessels and that the artery expresses both A- and B-type natriuretic peptide receptors; however, the vein (like the ventral aorta) expresses only the B-type natriuretic peptide receptor. My data suggest that a suite of signaling systems is ubiquitous in both arteries and veins in at least this elasmobranch species. Their role in hemodynamics and osmoregulation (perfusion of gill and rectal gland) remains to be determined.

The angiotensin type 2 receptor agonist Compound 21 elicits cerebroprotection in endothelin-1 induced ischemic stroke

DEFF Research Database (Denmark)

Joseph, Jason P; Mecca, Adam P; Regenhardt, Robert W

2014-01-01

Evidence indicates that angiotensin II type 2 receptors (AT2R) exert cerebroprotective actions during stroke. A selective non-peptide AT2R agonist, Compound 21 (C21), has been shown to exert beneficial effects in models of cardiac and renal disease, as well as hemorrhagic stroke. Here, we hypothe...

Inflammatory Murine Skin Responses to UV-B Light Are Partially Dependent on Endothelin-1 and Mast Cells

OpenAIRE

Metz, Martin; Lammel, Verena; Gibbs, Bernhard F.; Maurer, Marcus

2006-01-01

Endothelin (ET-1) has been shown to crucially contribute to UV-induced skin responses such as tanning. To test whether ET-1 is also involved in early cutaneous reactions to UV, we assessed ET-1 skin levels in UV-irradiated mice. In correlation with the levels of UV-induced skin inflammation, ET-1 concentrations increased substantially and continually. Moreover, blocking of ET-1 receptors (ETA) resulted in significantly decreased cutaneous inflammation following UV irradiation. When we assesse...

Synthesis and in vivo evaluation of a PET radioligand for imaging the endothelin-A receptor

Energy Technology Data Exchange (ETDEWEB)

Mathews, William B. [Department of Radiology, Johns Hopkins Medical Institutions, Baltimore, MD 21287 (United States)]. E-mail: bmathews@petscan.nm.jhu.edu; Zober, Tamas G. [Department of Radiology, Johns Hopkins Medical Institutions, Baltimore, MD 21287 (United States); Ravert, Hayden T. [Department of Radiology, Johns Hopkins Medical Institutions, Baltimore, MD 21287 (United States); Scheffel, Ursula [Department of Radiology, Johns Hopkins Medical Institutions, Baltimore, MD 21287 (United States); Hilton, John [Department of Radiology, Johns Hopkins Medical Institutions, Baltimore, MD 21287 (United States); Sleep, Darryl [Abbott Laboratories, Abbott Park, IL 60064 (United States); Dannals, Robert F. [Department of Radiology, Johns Hopkins Medical Institutions, Baltimore, MD 21287 (United States); Szabo, Zsolt [Department of Radiology, Johns Hopkins Medical Institutions, Baltimore, MD 21287 (United States)

2006-01-15

The endothelin-A receptor ligand Atrasentan (ABT-627) was radiolabeled by {sup 11}C-methylaton of the desmethyl precursor in phenolate form. In mice, the highest uptake of [{sup 11}C]ABT-627 was in the liver, kidneys and lungs. No significant binding was observed in mouse brain or heart. PET studies in a baboon, however, showed accumulation in the myocardium and lungs with a tissue/blood equilibrium reached at 40 min postinjection. Between 35 and 75 min, the heart/blood and lung/blood ratios were 1.72 and 1.31, respectively. Pretreatment with a 0.39 mg/kg dose of unlabeled ABT-627 inhibited the uptake of the tracer by 53-54% in both the myocardium and lungs at 65 min.

Synthesis and in vivo evaluation of a PET radioligand for imaging the endothelin-A receptor

International Nuclear Information System (INIS)

Mathews, William B.; Zober, Tamas G.; Ravert, Hayden T.; Scheffel, Ursula; Hilton, John; Sleep, Darryl; Dannals, Robert F.; Szabo, Zsolt

2006-01-01

The endothelin-A receptor ligand Atrasentan (ABT-627) was radiolabeled by 11 C-methylaton of the desmethyl precursor in phenolate form. In mice, the highest uptake of [ 11 C]ABT-627 was in the liver, kidneys and lungs. No significant binding was observed in mouse brain or heart. PET studies in a baboon, however, showed accumulation in the myocardium and lungs with a tissue/blood equilibrium reached at 40 min postinjection. Between 35 and 75 min, the heart/blood and lung/blood ratios were 1.72 and 1.31, respectively. Pretreatment with a 0.39 mg/kg dose of unlabeled ABT-627 inhibited the uptake of the tracer by 53-54% in both the myocardium and lungs at 65 min

Comparison of MEK/ERK pathway inhibitors on the upregulation of vascular G-protein coupled receptors in rat cerebral arteries

DEFF Research Database (Denmark)

Sandhu, Hardip; Ansar, Saema; Edvinsson, Lars

2010-01-01

on translational level and increased respective contractions. The prostanoid TP receptor mediated contraction curve was left-wards shifted by organ culture. Organ culture was associated with elevated pERK1/2 in the vascular smooth muscle cells: the MEK1/2 inhibitor U0126 attenuated the endothelin ET(B) receptor......Organ culture is an in vitro method for investigating cellular mechanisms involved in upregulation of vasocontractile G-protein coupled receptors. We hypothesize that mitogen-activated-protein kinase (MEK) and/or extracellular-signal-regulated kinase (ERK) specific inhibitors will attenuate the G......), prostanoid TP receptor, and angiotensin II receptor type 1 and type 2 were investigated. Results were verified by measurement of mRNA with real time PCR and by protein immunohistochemistry. Organ culture induced transcriptional upregulation of endothelin ET(B) receptor and of serotonin 5-HT(1B) receptor...

Endothelin-1 and antiangiogenesis

NARCIS (Netherlands)

S. Lankhorst (Stephanie); A.H.J. Danser (Jan); A.H. van den Meiracker (Anton)

2016-01-01

textabstractAntiangiogenesis, targeting vascular endothelial growth factor (VEGF), has become a well-established treatment for patients with cancer. This treatment is associated with nitric oxide (NO) suppression and a dose-dependent activation of the endothelin system, resulting in

UVB radiation generates sunburn pain and affects skin by activating epidermal TRPV4 ion channels and triggering endothelin-1 signaling.

Science.gov (United States)

Moore, Carlene; Cevikbas, Ferda; Pasolli, H Amalia; Chen, Yong; Kong, Wei; Kempkes, Cordula; Parekh, Puja; Lee, Suk Hee; Kontchou, Nelly-Ange; Yeh, Iwei; Ye, Iwei; Jokerst, Nan Marie; Fuchs, Elaine; Steinhoff, Martin; Liedtke, Wolfgang B

2013-08-20

At our body surface, the epidermis absorbs UV radiation. UV overexposure leads to sunburn with tissue injury and pain. To understand how, we focus on TRPV4, a nonselective cation channel highly expressed in epithelial skin cells and known to function in sensory transduction, a property shared with other transient receptor potential channels. We show that following UVB exposure mice with induced Trpv4 deletions, specifically in keratinocytes, are less sensitive to noxious thermal and mechanical stimuli than control animals. Exploring the mechanism, we find that epidermal TRPV4 orchestrates UVB-evoked skin tissue damage and increased expression of the proalgesic/algogenic mediator endothelin-1. In culture, UVB causes a direct, TRPV4-dependent Ca(2+) response in keratinocytes. In mice, topical treatment with a TRPV4-selective inhibitor decreases UVB-evoked pain behavior, epidermal tissue damage, and endothelin-1 expression. In humans, sunburn enhances epidermal expression of TRPV4 and endothelin-1, underscoring the potential of keratinocyte-derived TRPV4 as a therapeutic target for UVB-induced sunburn, in particular pain.

Increased endothelin-1 and diminished nitric oxide levels in blister fluids of patients with intermediate cold type complex regional pain syndrome type 1

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Niehof Sjoerd

2006-11-01

Full Text Available Abstract Background In complex regional pain syndrome type 1 (CRPS1 pro-inflammatory mediators and vascular changes play an important role in the sustained development and outcome of the disease. The aim of this study was to determine the involvement of vasoactive substances endothelin-1 (ET-1 and nitric oxide (NO during early chronic CRPS1. Methods Included were 29 patients with CRPS 1 who were diagnosed during the acute stage of their disease and observed during follow-up visits. Disease activity and impairment were determined and artificial suction blisters were made on the CRPS1 and the contralateral extremities for measurements of IL-6, TNF-α, ET-1 and nitrate/nitrite (NOx. Results The levels of IL-6, TNF-α and ET-1 in blister fluid in the CRPS1 extremity versus the contralateral extremity were significantly increased and correlated with each other, whereas NOx levels were decreased. Conclusion The NOx/ET-1 ratio appears to be disturbed in the intermediate stage of CRPS, resulting in vasoconstriction and consequently in a diminished tissue blood distribution.

The joint effect of the endothelin receptor B gene (EDNRB polymorphism rs10507875 and nitric oxide synthase 3 gene (NOS3 polymorphism rs869109213 in Slovenian patients with type 2 diabetes mellitus and diabetic retinopathy

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Dejan Bregar

2018-02-01

Full Text Available Increasing evidence suggests that endothelin and nitric oxide synthase genes and their products exert biological effects on the vasculature via the nitric oxide or endothelin pathway. The aim of the study was to evaluate the association of rs10507875 and rs869109213 (alone or in interaction with diabetic retinopathy (DR in subjects with type 2 diabetes mellitus (T2DM. We genotyped the single nucleotide polymorphism rs10507875 of the endothelin receptor B gene (EDNRB and variable number tandem repeats rs869109213 of the nitric oxide synthase 3 gene (NOS3 in 270 Slovenian patients with DR and T2DM and 256 controls with T2DM without clinical signs of DR. The genotyping was performed using either real-time polymerase chain reaction (PCR or standard PCR. We found a significant association between the genotypes of NOS3 rs869109213 polymorphism and the risk of DR in the co-dominant model (4a4b genotype; 1.99-fold increased risk [1.09-3.65]; 95% confidence interval [CI]; p = 0.02, co-dominant model (4a4a genotype; 4.16-fold increased risk [1.03-16.74]; 95% CI; p = 0.04, and dominant model (4a4a and 4a4b genotypes; 2.22-fold increased risk [1.26-3.92]; 95% CI; p = 0.01 compared to the 4b4b genotype. Moreover, the joint effect of the two polymorphisms on DR risk was greater than the individual effect of each polymorphism in the analyzed genetic models. Additionally, adjusted odds ratio showed an increased risk in dominant × dominant (4.15-fold [1.40-12.26]; 95% CI; p = 0.01 and recessive × dominant (2.24-fold [1.25-4.01]; 95% CI; p = 0.02 genotype combinations of the two polymorphisms. In conclusion, our results indicate that NOS3 rs869109213 polymorphism alone or in a combination with EDNRB rs10507875 polymorphism may be associated with DR in Slovenian patients with T2DM.

Elevated plasma endothelin-1 and pulmonary arterial pressure in children exposed to air pollution.

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Calderón-Garcidueñas, Lilian; Vincent, Renaud; Mora-Tiscareño, Antonieta; Franco-Lira, Maricela; Henríquez-Roldán, Carlos; Barragán-Mejía, Gerardo; Garrido-García, Luis; Camacho-Reyes, Laura; Valencia-Salazar, Gildardo; Paredes, Rogelio; Romero, Lina; Osnaya, Hector; Villarreal-Calderón, Rafael; Torres-Jardón, Ricardo; Hazucha, Milan J; Reed, William

2007-08-01

Controlled exposures of animals and humans to particulate matter (PM) or ozone air pollution cause an increase in plasma levels of endothelin-1, a potent vasoconstrictor that regulates pulmonary arterial pressure. The primary objective of this field study was to determine whether Mexico City children, who are chronically exposed to levels of PM and O(3) that exceed the United States air quality standards, have elevated plasma endothelin-1 levels and pulmonary arterial pressures. We conducted a study of 81 children, 7.9 +/- 1.3 years of age, lifelong residents of either northeast (n = 19) or southwest (n = 40) Mexico City or Polotitlán (n = 22), a control city with PM and O(3) levels below the U.S. air quality standards. Clinical histories, physical examinations, and complete blood counts were done. Plasma endothelin-1 concentrations were determined by immunoassay, and pulmonary arterial pressures were measured by Doppler echocardiography. Mexico City children had higher plasma endothelin-1 concentrations compared with controls (p < 0.001). Mean pulmonary arterial pressure was elevated in children from both northeast (p < 0.001) and southwest (p < 0.05) Mexico City compared with controls. Endothelin-1 levels in Mexico City children were positively correlated with daily outdoor hours (p = 0.012), and 7-day cumulative levels of PM air pollution < 2.5 mum in aerodynamic diameter (PM(2.5)) before endothelin-1 measurement (p = 0.03). Chronic exposure of children to PM(2.5) is associated with increased levels of circulating endothelin-1 and elevated mean pulmonary arterial pressure.

Elevated Plasma Endothelin-1 and Pulmonary Arterial Pressure in Children Exposed to Air Pollution

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Calderón-Garcidueñas, Lilian; Vincent, Renaud; Mora-Tiscareño, Antonieta; Franco-Lira, Maricela; Henríquez-Roldán, Carlos; Barragán-Mejía, Gerardo; Garrido-García, Luis; Camacho-Reyes, Laura; Valencia-Salazar, Gildardo; Paredes, Rogelio; Romero, Lina; Osnaya, Hector; Villarreal-Calderón, Rafael; Torres-Jardón, Ricardo; Hazucha, Milan J.; Reed, William

2007-01-01

Background Controlled exposures of animals and humans to particulate matter (PM) or ozone air pollution cause an increase in plasma levels of endothelin-1, a potent vasoconstrictor that regulates pulmonary arterial pressure. Objectives The primary objective of this field study was to determine whether Mexico City children, who are chronically exposed to levels of PM and O3 that exceed the United States air quality standards, have elevated plasma endothelin-1 levels and pulmonary arterial pressures. Methods We conducted a study of 81 children, 7.9 ± 1.3 years of age, lifelong residents of either northeast (n = 19) or southwest (n = 40) Mexico City or Polotitlán (n = 22), a control city with PM and O3 levels below the U.S. air quality standards. Clinical histories, physical examinations, and complete blood counts were done. Plasma endothelin-1 concentrations were determined by immunoassay, and pulmonary arterial pressures were measured by Doppler echocardiography. Results Mexico City children had higher plasma endothelin-1 concentrations compared with controls (p < 0.001). Mean pulmonary arterial pressure was elevated in children from both northeast (p < 0.001) and southwest (p < 0.05) Mexico City compared with controls. Endothelin-1 levels in Mexico City children were positively correlated with daily outdoor hours (p = 0.012), and 7-day cumulative levels of PM air pollution < 2.5 μm in aerodynamic diameter (PM2.5) before endothelin-1 measurement (p = 0.03). Conclusions Chronic exposure of children to PM2.5 is associated with increased levels of circulating endothelin-1 and elevated mean pulmonary arterial pressure. PMID:17687455

CaMKII inhibition with KN93 attenuates endothelin and serotonin receptor-mediated vasoconstriction and prevents subarachnoid hemorrhage-induced deficits in sensorimotor function

DEFF Research Database (Denmark)

Edvinsson, Lars; Povlsen, Gro Klitgaard; Ahnstedt, Hilda

2014-01-01

tested the hypothesis that inhibition of calcium calmodulin-dependent protein kinase II (CaMKII) may reduce cerebral vasoconstriction mediated by endothelin and serotonin receptors and improve neurological outcome after experimental SAH. METHODS: SAH was induced in adult rats by injection of 250 μ...

Characterization of endothelin receptors on a human neuroblastoma cell line: evidence for the ETA subtype.

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Wilkes, L C; Boarder, M R

1991-11-01

1. Specific binding sites for synthetic endothelin (ET) isoforms were studied on intact cells of the SK-N-MC cell line, derived from a human neuroblastoma. 2. [125I]-ET-1 (2.5 x 10(-11) M) specifically bound to a single class of binding sites on these cells (Hill coefficient of 1.06 +/- 0.04, n = 3) with an apparent Kd of 1.4 +/- 0.3 x 10(-9) M and a Bmax of 3.1 +/- 1.0 pmol mg-1 protein. [125I]-ET-3 (2.5 x 10(-11) M), did not specifically bind to SK-N-MC cells. 3. The binding of [125I]-ET-1 was competitively inhibited by other ET isoforms, the order of potency being ET-1 greater than sarafotoxin S6b greater than ET-3. 4. Association of 1 nM [125I]-ET-1 at 37 degrees C reached apparent equilibrium at 60-80 min, with half-maximal binding being achieved at 12 min. 5. Dissociation was measured after both 10 min and 60 min of association with 64% and 30% respectively of specifically bound [125I]-ET-1 dissociating. The actual amounts of [125I]-ET-1 dissociated were similar in both cases. 6. Incubation of [125I]-ET-3 with SK-N-MC cells at 37 degrees C for 60 min did not result in significant degradation of this peptide. However, [125I]-ET-1 was broken down by incubation with SK-N-MC cells, the pattern of degradation of dissociable [125I]-ET-1 (and that found in the supernatant) being different from that of non-dissociable [125I]-ET-1. 7. ET-1 concentration-dependently induced an increase in total inositol phosphate accumulation in subconfluent (but not in confluent) cultures of SK-N-MC cells (EC50 = 6.43 +/- 1.9 x 1010M). ET-3 was without effect. 8. These results show that ET-1 specifically binds to SK-N-MC cells with the characteristics of an ETA receptor. Our earlier finding that adrenal chromaffin cells express an ETB receptor indicates the existence of multiple ET receptor types on neuronal cells.

Plasma concentrations of endothelin in patients with abnormal vascular reactivity

International Nuclear Information System (INIS)

Predel, H.G.; Meyer-Lehnert, H.; Baecker, A.; Stelkens, H.; Kramer, H.J.

1990-01-01

We measured circulating concentrations of endothelin in healthy subjects and in patients with abnormal vascular reactivity. Endothelin concentrations were determined by radioimmunoassay after extraction of plasma using Sep-Pak C-18 cartridges in healthy subjects, in patients with diabetes mellitus type I, in patients with mild to moderate essential hypertension and in non-dialyzed patients with stable chronic renal failure. Plasma concentrations were similar in healthy controls, in diabetics and in hypertensive patients averaging 5.0±0.6 pg/ml, 4.7±0.2 pg/ml and 6.5±1.0 pg/ml, respectively. In contrast, plasma concentrations of endothelin were markedly elevated in patients with chronic renal failure averaging 16.6±2.9 pg/ml. No correlations were observed between serum creatinine concentrations ranging from 124 to 850 μmol/l or blood pressure and plasma concentrations of endothelin. Bicycle ergometric exercise in six healthy subjects and an acute modest i.v. saline load of 1,000 ml of 0.45% NaCl administered within 60 min in six patients with mild essential hypertension did not affect plasma concentrations of endothelin

Over, and Underexpression of Endothelin 1 and TGF-Beta Family Ligands and Receptors in Lung Tissue of Broilers with Pulmonary Hypertension

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Dominguez-Avila, Norma; Ruiz-Castañeda, Gabriel; González-Ramírez, Javier; Fernandez-Jaramillo, Nora; Escoto, Jorge; Sánchez-Muñoz, Fausto; Marquez-Velasco, Ricardo; Bojalil, Rafael; Espinosa-Cervantes, Román; Sánchez, Fausto

2013-01-01

Transforming growth factor beta (TGFβ) is a family of genes that play a key role in mediating tissue remodeling in various forms of acute and chronic lung disease. In order to assess their role on pulmonary hypertension in broilers, we determined mRNA expression of genes of the TGFβ family and endothelin 1 in lung samples from 4-week-old chickens raised either under normal or cold temperature conditions. Both in control and cold-treated groups of broilers, endothelin 1 mRNA expression levels in lungs from ascitic chickens were higher than levels from healthy birds (P 0.05). BAMBI mRNA gene expression was lowest in birds with ascites only in the control group as compared with the values from healthy birds (P < 0.05). PMID:24286074

Celecoxib, but not indomethacin, ameliorates the hypertensive and perivascular fibrotic actions of cyclosporine in rats: Role of endothelin signaling

International Nuclear Information System (INIS)

El-Mas, Mahmoud M.; Helmy, Maged W.; Ali, Rabab M.; El-Gowelli, Hanan M.

2015-01-01

The immunosuppressant drug cyclosporine (CSA) is used with nonsteroidal antiinflammatory drugs (NSAIDs) in arthritic conditions. In this study, we investigated whether NSAIDs modify the deleterious hypertensive action of CSA and the role of endothelin (ET) receptors in this interaction. Pharmacologic, protein expression, and histopathologic studies were performed in rats to investigate the roles of endothelin receptors (ET A /ET B ) in the hemodynamic interaction between CSA and two NSAIDs, indomethacin and celecoxib. Tail-cuff plethysmography measurements showed that CSA (20 mg kg −1 day −1 , 10 days) increased systolic blood pressure (SBP) and heart rate (HR). CSA hypertension was associated with renal perivascular fibrosis and divergent changes in immunohistochemical signals of renal arteriolar ET A (increases) and ET B (decreases) receptors. While these effects of CSA were preserved in rats treated concomitantly with indomethacin (5 mg kg −1 day −1 ), celecoxib (10 mg kg −1 day −1 ) abolished the pressor, tachycardic, and fibrotic effects of CSA and normalized the altered renal ET A /ET B receptor expressions. Selective blockade of ET A receptors by atrasentan (5 mg kg −1 day −1 ) abolished the pressor response elicited by CSA or CSA plus indomethacin. Alternatively, BQ788 (ET B receptor blocker, 0.1 mg kg −1 day −1 ) caused celecoxib-sensitive elevations in SBP and potentiated the pressor response evoked by CSA. Together, the improved renovascular fibrotic and endothelin receptor profile (ET A downregulation and ET B upregulation) mediate, at least partly, the protective effect of celecoxib against the hypertensive effect of CSA. Clinically, the use of celecoxib along with CSA in the management of arthritic conditions might provide hypertension-free regimen. - Highlights: • Chronic CSA causes hypertension and renal perivascular fibrosis in rats. • CSA increased and decreased renal ET A and ET B receptor expression, respectively. • CSA

Stimulation of phospholipase C in cultured microvascular endothelial cells from human frontal lobe by histamine, endothelin and purinoceptor agonists.

Science.gov (United States)

Purkiss, J. R.; West, D.; Wilkes, L. C.; Scott, C.; Yarrow, P.; Wilkinson, G. F.; Boarder, M. R.

1994-01-01

1. Cultures of endothelial cells derived from the microvasculature of human frontal lobe have been investigated for phospholipase C (PLC) responses to histamine, endothelins and purinoceptor agonists. 2. Using cells prelabelled with [3H]-inositol and measuring total [3H]-inositol (poly)phosphates, histamine acting at H1 receptors stimulated a substantial response with an EC50 of about 10 microM. 3. Endothelin-1 also gave a clear stimulation of phosphoinositide-specific phospholipase C. Both concentration-response curves and binding curves showed effective responses and binding in the rank order of endothelin-1 > sarafotoxin S6b > endothelin-3, suggesting an ETA receptor. 4. Assay of total [3H]-inositol (poly)phosphates showed no response to the purinoceptor agonists, 2-methylthioadenosine 5'-trisphosphate (2MeSATP), adenosine 5'-O-(3-thiotrisphosphate) (ATP gamma S) or beta,gamma-methylene ATP. Both ATP and UTP gave a small PLC response. 5. Similarly, when formation of [32P]-phosphatidic acid from cells prelabelled with 32Pi was used as an index of both PLC and phospholipase D, a small response to ATP and UTP was seen but there was no response to the other purinoceptor agonists tested. 6. Study by mass assay of stimulation by ATP of inositol (1,4,5) trisphosphate accumulation revealed a transient response in the first few seconds, a decline to basal, followed by a small sustained response. 7. These results show that human brain endothelial cells in culture are responsive to histamine and endothelins in a manner which may regulate brain capillary permeability. Purines exert a lesser influence. PMID:8032588

NITRIC OXIDE AND ENDOTHELIN-1 IN CHILDREN WITH DIGESTIVE DISORDERS

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I. V. Panova

2012-01-01

Full Text Available The important part in the group of biological compounds, participating in the regulation of the functions of the gastro-intestinal tract, is assigned to endothelial factors because of their impact on the majority of physiological and pathophysiological processes of the digestive system. The article provides information about physiological role of nitric oxide and endothelin-1 and presents a review of scientific data on the participation of nitric oxide and endothelin-1 in the pathogenesis of many digestive system diseases, emphasizing chronic inflammatory disorders of the upper gastrointestinal tract. The authors accentuate the importance of endothelium endocrine function research in children with esophagogastroduodenal disorders at the beginning of puberty, which is the critical period of ontogenesis.

Inhibitory effect of fentanyl citrate on the release of endothlin-1 induced by bradykinin in melanoma cells.

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Andoh, Tsugunobu; Shinohara, Akira; Kuraishi, Yasushi

2017-02-01

Our previous study showed that the μ-opioid receptor agonist fentanyl citrate inhibits endothelin-1-and bradykinin-mediated pain responses in mice orthotopically inoculated with melanoma cells. We also demonstrated that bradykinin induces endothelin-1 secretion in melanoma cells. However, the analgesic mechanisms of fentanyl citrate remain unclear. Thus, the present study was conducted to determine whether fentanyl citrate affects bradykinin-induced endothelin-1 secretion in B16-BL6 melanoma cells. The amount of endothelin-1 in the culture medium was measured using an enzyme immunoassay. The expression of endothelin-1, kinin B 2 receptors, and μ-opioid receptors in B16-BL/6 melanoma cells was determined using immunocytochemistry. Fentanyl citrate inhibited bradykinin-induced endothelin-1 secretion. The inhibitory effect of fentanyl citrate on the secretion of endothelin-1 was attenuated by the μ-opioid receptor antagonist naloxone methiodide. The immunoreactivities of endothelin-1, kinin B 2 receptors, and μ-opioid receptors in B16-BL6 melanoma cells were observed. These results suggest that fentanyl citrate regulates bradykinin-induced endothelin-1 secretion through μ-opioid receptors in melanoma cells. Copyright © 2016 Institute of Pharmacology, Polish Academy of Sciences. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

Study of Endothelin-1 and Vascular Endothelial Growth Factor in Patients with Cancer Colon

International Nuclear Information System (INIS)

ABDEL-GAWAD, I.A.; HASSANEIN, H.M.R.; BAHGAT, N.A.; ABDEL SATTAR, M.A.; EL-SISSY, A.H.; ALTAWEEL, M.A.; HELAL, A.M.

2008-01-01

Purpose: The levels of endothelin-1 and VEGF were evaluated in the sera of newly diagnosed patients with cancer colon and were compared with the routinely used tumor markers; CEA and CA19.9. Their relations with some prognostic factors of cancer colon were also investigated. Subjects and Methods: The study included 48 patients with cancer colon and 20 apparently healthy volunteers as a control group. Patients were 23 males and 25 females with age range from 18 to 71 years (mean = 47±1.8). Both serum and plasma samples were obtained from patients and controls. Results: Six percent of patients had grade 1 tumors, 77% had grade 2 and 17% had grade 3 disease. As regard to the stage, 52% of patients were stage II, 35.5% were stage III, while 12.5% were stage IV. Liver metastasis was present in 12.5%, while 35% showed lymph node metastasis. The VEGF, endothelin-1, CA 19.9 and CEA were significantly higher in the cancer colon patients than in control groups (p-value <0.001, 0.006, <0.001 and <0.001; respectively). Plasma level of endothelin-1 and serum level of VEGF showed significantly higher levels in advanced stages of the disease (p value <0 .001) and in presence of liver metastasis (p value <0.001 and 0.002 respectively), while VEGF showed significant result when compared with the grade (p value=0.032). In this study, when comparing the levels of plasma endothelin-1 and serum VEGF between the metastatic, non-metastatic liver patients of the cancer colon group and the control group, the comparison was statistically significant for both markers (p<0.001). Endothelin-1 and VEGF showed significant positive correlation (r=0.77 and p-value <0.0001). Serum VEGF and CA 19.9 showed good sensitivities which were not different (97.9% and 87.5%; respectively), while there was no significant difference between VEGF, CA 19.9 and CEA with respect to specificities (100%, 90% and 100% respectively). Conclusion: Both endothelin-1 and VEGF may be used for early detection of liver

Endothelin receptor antagonist and airway dysfunction in pulmonary arterial hypertension

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Borst Mathias M

2009-12-01

Full Text Available Abstract Background In idiopathic pulmonary arterial hypertension (IPAH, peripheral airway obstruction is frequent. This is partially attributed to the mediator dysbalance, particularly an excess of endothelin-1 (ET-1, to increased pulmonary vascular and airway tonus and to local inflammation. Bosentan (ET-1 receptor antagonist improves pulmonary hemodynamics, exercise limitation, and disease severity in IPAH. We hypothesized that bosentan might affect airway obstruction. Methods In 32 IPAH-patients (19 female, WHO functional class II (n = 10, III (n = 22; (data presented as mean ± standard deviation pulmonary vascular resistance (11 ± 5 Wood units, lung function, 6 minute walk test (6-MWT; 364 ± 363.7 (range 179.0-627.0 m, systolic pulmonary artery pressure, sPAP, 79 ± 19 mmHg, and NT-proBNP serum levels (1427 ± 2162.7 (range 59.3-10342.0 ng/L were measured at baseline, after 3 and 12 months of oral bosentan (125 mg twice per day. Results and Discussion At baseline, maximal expiratory flow at 50 and 25% vital capacity were reduced to 65 ± 25 and 45 ± 24% predicted. Total lung capacity was 95.6 ± 12.5% predicted and residual volume was 109 ± 21.4% predicted. During 3 and 12 months of treatment, 6-MWT increased by 32 ± 19 and 53 ± 69 m, respectively; p Conclusion This study gives first evidence in IPAH, that during long-term bosentan, improvement of hemodynamics, functional parameters or serum biomarker occur independently from persisting peripheral airway obstruction.

Alternatively Activated (M2) Macrophage Phenotype Is Inducible by Endothelin-1 in Cultured Human Macrophages.

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Soldano, Stefano; Pizzorni, Carmen; Paolino, Sabrina; Trombetta, Amelia Chiara; Montagna, Paola; Brizzolara, Renata; Ruaro, Barbara; Sulli, Alberto; Cutolo, Maurizio

2016-01-01

Alternatively activated (M2) macrophages are phenotypically characterized by the expression of specific markers, mainly macrophage scavenger receptors (CD204 and CD163) and mannose receptor-1 (CD206), and participate in the fibrotic process by over-producing pro-fibrotic molecules, such as transforming growth factor-beta1 (TGFbeta1) and metalloproteinase (MMP)-9. Endothelin-1 (ET-1) is implicated in the fibrotic process, exerting its pro-fibrotic effects through the interaction with its receptors (ETA and ETB). The study investigated the possible role of ET-1 in inducing the transition from cultured human macrophages into M2 cells. Cultured human monocytes (THP-1 cell line) were activated into macrophages (M0 macrophages) with phorbol myristate acetate and subsequently maintained in growth medium (M0-controls) or treated with either ET-1 (100nM) or interleukin-4 (IL-4, 10ng/mL, M2 inducer) for 72 hours. Similarly, primary cultures of human peripheral blood monocyte (PBM)-derived macrophages obtained from healthy subjects, were maintained in growth medium (untreated cells) or treated with ET-1 or IL-4 for 6 days. Both M0 and PBM-derived macrophages were pre-treated with ET receptor antagonist (ETA/BRA, bosentan 10-5M) for 1 hour before ET-1 stimulation. Protein and gene expression of CD204, CD206, CD163, TGFbeta1 were analysed by immunocytochemistry, Western blotting and quantitative real time polymerase chain reaction (qRT-PCR). Gene expression of interleukin(IL)-10 and macrophage derived chemokine (CCL-22) was evaluated by qRT-PCR. MMP-9 production was investigated by gel zymography. ET-1 significantly increased the expression of M2 phenotype markers CD204, CD206, CD163, IL-10 and CCL-22, and the production of MMP-9 in both cultures of M0 and PBM-derived macrophages compared to M0-controls and untreated cells. In cultured PBM-derived macrophages, ET-1 increased TGFbeta1 protein and gene expression compared to untreated cells. The ET-1-mediated effects were

Endothelin receptor antagonist attenuates oxidative stress in a neonatal sepsis piglet model.

Science.gov (United States)

Goto, Tatenobu; Hussein, Mohamed Hamed; Kato, Shin; Daoud, Ghada Abdel-Hamid; Kato, Takenori; Sugiura, Takahiro; Kakita, Hiroki; Nobata, Masanori; Kamei, Michi; Mizuno, Haruo; Imai, Masaki; Ito, Tetsuya; Kato, Ineko; Suzuki, Satoshi; Okada, Noriko; Togari, Hajime; Okada, Hidechika

2012-12-01

Oxidative stress (oxidant-antioxidant imbalance) plays an important role in the pathophysiology of neonatal sepsis. This study evaluated whether an antisense peptide endothelin receptor antagonist, ETR-P1/fl, could attenuate oxidative stress in a neonatal sepsis model. A total of 18 3-d-old piglets were anesthetized and mechanically ventilated. Six piglets received cecal ligation and perforation (CLP group) for induction of sepsis. Six piglets also received continuous infusion (0.05 mg/kg/h) of ETR-P1/fl 30 min after CLP (ETR-P1/fl group). Six piglets received a sham operation. Serum total hydroperoxide (TH), biological antioxidant potentials (BAPs), oxidative stress index (OSI, calculated as TH/BAP), interleukin (IL)-6, serum glutamic oxaloacetic transaminase (GOT), and creatinine were measured before CLP and at 1, 3, and 6 h after CLP. CLP evoked a state of shock resulting in elevated TH, OSI, and IL-6 levels. ETR-P1/fl administration after CLP resulted in lower serum TH at 1 and 3 h after CLP, OSI at 1 and 3 h after CLP, IL-6 at 1 and 3 h after CLP, and GOT at 3 and 6 h after CLP as compared with the CLP group. ETR-P1/fl treatment significantly attenuated the elevation of serum oxidative stress markers (TH and OSI), IL-6, and GOT in a progressive neonatal sepsis CLP model.

Confirmation of translatability and functionality certifies the dual endothelin1/VEGFsp receptor (DEspR) protein.

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Herrera, Victoria L M; Steffen, Martin; Moran, Ann Marie; Tan, Glaiza A; Pasion, Khristine A; Rivera, Keith; Pappin, Darryl J; Ruiz-Opazo, Nelson

2016-06-14

In contrast to rat and mouse databases, the NCBI gene database lists the human dual-endothelin1/VEGFsp receptor (DEspR, formerly Dear) as a unitary transcribed pseudogene due to a stop [TGA]-codon at codon#14 in automated DNA and RNA sequences. However, re-analysis is needed given prior single gene studies detected a tryptophan [TGG]-codon#14 by manual Sanger sequencing, demonstrated DEspR translatability and functionality, and since the demonstration of actual non-translatability through expression studies, the standard-of-excellence for pseudogene designation, has not been performed. Re-analysis must meet UNIPROT criteria for demonstration of a protein's existence at the highest (protein) level, which a priori, would override DNA- or RNA-based deductions. To dissect the nucleotide sequence discrepancy, we performed Maxam-Gilbert sequencing and reviewed 727 RNA-seq entries. To comply with the highest level multiple UNIPROT criteria for determining DEspR's existence, we performed various experiments using multiple anti-DEspR monoclonal antibodies (mAbs) targeting distinct DEspR epitopes with one spanning the contested tryptophan [TGG]-codon#14, assessing: (a) DEspR protein expression, (b) predicted full-length protein size, (c) sequence-predicted protein-specific properties beyond codon#14: receptor glycosylation and internalization, (d) protein-partner interactions, and (e) DEspR functionality via DEspR-inhibition effects. Maxam-Gilbert sequencing and some RNA-seq entries demonstrate two guanines, hence a tryptophan [TGG]-codon#14 within a compression site spanning an error-prone compression sequence motif. Western blot analysis using anti-DEspR mAbs targeting distinct DEspR epitopes detect the identical glycosylated 17.5 kDa pull-down protein. Decrease in DEspR-protein size after PNGase-F digest demonstrates post-translational glycosylation, concordant with the consensus-glycosylation site beyond codon#14. Like other small single-transmembrane proteins, mass

Sigma-1 Receptor Plays a Negative Modulation on N-type Calcium Channel

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Kang Zhang

2017-05-01

Full Text Available The sigma-1 receptor is a 223 amino acids molecular chaperone with a single transmembrane domain. It is resident to eukaryotic mitochondrial-associated endoplasmic reticulum and plasma membranes. By chaperone-mediated interactions with ion channels, G-protein coupled receptors and cell-signaling molecules, the sigma-1 receptor performs broad physiological and pharmacological functions. Despite sigma-1 receptors have been confirmed to regulate various types of ion channels, the relationship between the sigma-1 receptor and N-type Ca2+ channel is still unclear. Considering both sigma-1 receptors and N-type Ca2+ channels are involved in intracellular calcium homeostasis and neurotransmission, we undertake studies to explore the possible interaction between these two proteins. In the experiment, we confirmed the expression of the sigma-1 receptors and the N-type calcium channels in the cholinergic interneurons (ChIs in rat striatum by using single-cell reverse transcription-polymerase chain reaction (scRT-PCR and immunofluorescence staining. N-type Ca2+ currents recorded from ChIs in the brain slice of rat striatum was depressed when sigma-1 receptor agonists (SKF-10047 and Pre-084 were administrated. The inhibition was completely abolished by sigma-1 receptor antagonist (BD-1063. Co-expression of the sigma-1 receptors and the N-type calcium channels in Xenopus oocytes presented a decrease of N-type Ca2+ current amplitude with an increase of sigma-1 receptor expression. SKF-10047 could further depress N-type Ca2+ currents recorded from oocytes. The fluorescence resonance energy transfer (FRET assays and co-immunoprecipitation (Co-IP demonstrated that sigma-1 receptors and N-type Ca2+ channels formed a protein complex when they were co-expressed in HEK-293T (Human Embryonic Kidney -293T cells. Our results revealed that the sigma-1 receptors played a negative modulation on N-type Ca2+ channels. The mechanism for the inhibition of sigma-1 receptors on

Regular aerobic exercise reduces endothelin-1-mediated vasoconstrictor tone in overweight and obese adults.

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Dow, Caitlin A; Stauffer, Brian L; Brunjes, Danielle L; Greiner, Jared J; DeSouza, Christopher A

2017-09-01

What is the central question of this study? Does aerobic exercise training reduce endothelin-1 (ET-1)-mediated vasoconstrictor tone in overweight/obese adults? And, if so, does lower ET-1 vasoconstriction underlie the exercise-related enhancement in endothelium-dependent vasodilatation in overweight/obese adults? What is the main finding and its importance? Regular aerobic exercise reduces ET-1-mediated vasoconstrictor tone in previously sedentary overweight/obese adults, independent of weight loss. Decreased ET-1 vasoconstriction is an important mechanism underlying the aerobic exercise-induced improvement in endothelium-dependent vasodilator function in overweight/obese adults. Endothelin-1 (ET-1)-mediated vasoconstrictor tone is elevated in overweight and obese adults, contributing to vasomotor dysfunction and increased cardiovascular disease risk. Although the effects of habitual aerobic exercise on endothelium-dependent vasodilatation in overweight/obese adults have been studied, little is known regarding ET-1-mediated vasoconstriction. Accordingly, the aims of the present study were to determine the following: (i) whether regular aerobic exercise training reduces ET-1-mediated vasoconstrictor tone in overweight and obese adults; and, if so, (ii) whether the reduction in ET-1-mediated vasoconstriction contributes to exercise-induced improvement in endothelium-dependent vasodilatation in this population. Forearm blood flow (FBF) in response to intra-arterial infusion of selective ET A receptor blockade (BQ-123, 100 nmol min -1 for 60 min), acetylcholine [4.0, 8.0 and 16.0 μg (100 ml tissue) -1  min -1 ] in the absence and presence of ET A receptor blockade and sodium nitroprusside [1.0, 2.0 and 4.0 μg (100 ml tissue) -1  min -1 ] were determined before and after a 3 month aerobic exercise training intervention in 25 (16 men and nine women) overweight/obese (body mass index 30.1 ± 0.5 kg m -2 ) adults. The vasodilator response to BQ-123 was

Orphan nuclear receptor Nur77 is a novel negative regulator of endothelin-1 expression in vascular endothelial cells.

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Qin, Qing; Chen, Ming; Yi, Bing; You, Xiaohua; Yang, Ping; Sun, Jianxin

2014-12-01

Endothelin-1 (ET-1) produced by vascular endothelial cells plays essential roles in the regulation of vascular tone and development of cardiovascular diseases. The objective of this study is to identify novel regulators implicated in the regulation of ET-1 expression in vascular endothelial cells (ECs). By using quantitative real-time PCR (qRT-PCR) and enzyme-linked immunosorbent assay (ELISA), we show that either ectopic expression of orphan nuclear receptor Nur77 or pharmacological activation of Nur77 by 6-mercaptopurine (6-MP) substantially inhibits ET-1 expression in human umbilical vein endothelial cells (HUVECs), under both basal and thrombin-stimulated conditions. Furthermore, thrombin-stimulated ET expression is significantly augmented in both Nur77 knockdown ECs and aort from Nur77 knockout mice, suggesting that Nur77 is a negative regulator of ET-1 expression. Inhibition of ET-1 expression by Nur77 occurs at gene transcriptional levels, since Nur77 potently inhibits ET-1 promoter activity, without affecting ET-1 mRNA stability. As shown in electrophoretic mobility shift assay (EMSA), Nur77 overexpression markedly inhibits both basal and thrombin-stimulated transcriptional activity of AP-1. Mechanistically, we demonstrate that Nur77 specially interacts with c-Jun and inhibits AP-1 dependent c-Jun promoter activity, which leads to a decreased expression of c-Jun, a critical component involved in both AP-1 transcriptional activity and ET-1 expression in ECs. These findings demonstrate that Nur77 is a novel negative regulator of ET-1 expression in vascular ECs through an inhibitory interaction with the c-Jun/AP-1 pathway. Activation of Nur77 may represent a useful therapeutic strategy for preventing certain cardiovascular diseases, such as atherosclerosis and pulmonary artery hypertension. Copyright © 2014 Elsevier Ltd. All rights reserved.

Influence of specific and non-specific endothelin receptor antagonists on renal morphology in rats with surgical renal ablation.

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Nabokov, A; Amann, K; Wagner, J; Gehlen, F; Münter, K; Ritz, E

1996-03-01

Studies in experimental models of chronic renal failure suggest an important role for the endothelin system in the development of renal scarring. Endothelin receptor (ETR) anatagonists interfere with progression, but it has not been resolved (i) whether this is true for all models of renal damage, (ii) to what extent the effect is modulated by systemic blood pressure and (iii) whether the effect is similar for ETAR and ETA/ETBR antagonists. 5/6 subtotal nephrectomy (SNX) by surgical ablation in male Sprague-Dawley rats. Comparison of ACE inhibitor Trandolapril (0.1 mg/kg/day), ETAR antagonist BMS 182874 (30 mg/kg/day) and ETAR/ETBR antagonist Ro 46-2005 (30 mg/kg/day) by gavage. Duration of the experiment eight weeks. Systolic blood pressure by tail plethysmography. Perfusion fixation of kidneys and morphometric analysis ET-1 and ETA/ETBR by quantitative PCR. SNX caused a significant (P < 0.01) increase of systolic blood pressure (170 +/- 8.6 mmHg) compared to sham operated controls (131 +/- 5.3 mmHg). Blood pressure was significantly (P < 0.001) lower with Trandolapril (128 +/- 5.3 mmHg), but not with BMS 182874 (153 +/- 5.9 mmHg) or Ro 46-2005 (167 +/- 7.6 mmHg). Compared to sham operated rats (0.03 +/- 0.01) glomerulosclerosis index (GSI) was significantly (P < 0.01) higher in the untreated SNX group (0.9 +/- 0.15). Significantly lower GSI was found in Trandolapril treated (0.29 +/- 0.04), BMS 182874 treated (0.36 +/- 0.05), and Ro 46-2005 treated animals (0.45 +/- 0.11). The effect of BMS 182874 was accompanied by lower tubulointerstitial damage index. Mean glomerular volume was dramatically increased (P < 0.001) in SNX rats as compared to sham operated animals. This glomerular enlargement was partially prevented by Trandolapril (P < 0.05), but not by either ETR antagonist. ET-1 mRNA tended to be higher in SNX irrespective of treatment, while ETAR and ETBR mRNA were significantly lower. Both specific (ETAR) and non-specific (ETA/ETBR) endothelin antagonists

Modulation by endothelin-1 of spontaneous activity and membrane currents of atrioventricular node myocytes from the rabbit heart.

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Stéphanie C Choisy

Full Text Available The atrioventricular node (AVN is a key component of the cardiac pacemaker-conduction system. Although it is known that receptors for the peptide hormone endothelin-1 (ET-1 are expressed in the AVN, there is very little information available on the modulatory effects of ET-1 on AVN electrophysiology. This study characterises for the first time acute modulatory effects of ET-1 on AVN cellular electrophysiology.Electrophysiological experiments were conducted in which recordings were made from rabbit isolated AVN cells at 35-37°C using the whole-cell patch clamp recording technique.Application of ET-1 (10 nM to spontaneously active AVN cells led rapidly (within ~13 s to membrane potential hyperpolarisation and cessation of spontaneous action potentials (APs. This effect was prevented by pre-application of the ET(A receptor inhibitor BQ-123 (1 µM and was not mimicked by the ET(B receptor agonist IRL-1620 (300 nM. In whole-cell voltage-clamp experiments, ET-1 partially inhibited L-type calcium current (I(Ca,L and rapid delayed rectifier K(+ current (I(Kr, whilst it transiently activated the hyperpolarisation-activated current (I(f at voltages negative to the pacemaking range, and activated an inwardly rectifying current that was inhibited by both tertiapin-Q (300 nM and Ba(2+ ions (2 mM; each of these effects was sensitive to ET(A receptor inhibition. In cells exposed to tertiapin-Q, ET-1 application did not produce membrane potential hyperpolarisation or immediate cessation of spontaneous activity; instead, there was a progressive decline in AP amplitude and depolarisation of maximum diastolic potential.Acutely applied ET-1 exerts a direct modulatory effect on AVN cell electrophysiology. The dominant effect of ET-1 in this study was activation of a tertiapin-Q sensitive inwardly rectifying K(+ current via ET(A receptors, which led rapidly to cell quiescence.

Glucocorticoid receptors in monocytes in type 1 diabetes mellitus

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Damm, P; Binder, C

1989-01-01

Glucocorticoid receptor binding characteristics were investigated in 8 males with poorly controlled Type 1 diabetes mellitus and 14 healthy males. The cell type studied was monocytes, and a method for correction for heterogeneity in glucocorticoid binding in a mononuclear leucocyte population...... or with HbA1c. In conclusion, no major abnormalities in glucocorticoid receptor binding characteristics could be demonstrated in Type 1 diabetes mellitus....... was introduced. The number of receptors and the dissociation constant KD were, respectively, 13,699 and 2.93 X 10(-8) mol/l for the control group and 15,788 and 2.75 X 10(-8) mol/l for diabetics (p greater than 0.05). In diabetics, KD correlated negatively with blood glucose (r = 0.762, p less than 0...

Lactoferrin- Endothelin-1 Axis Contributes to the Development and Invasiveness of Triple Negative Breast Cancer Phenotypes

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Ha, Ngoc-Han; Nair, Vasudha; Reddy, Divijendra Natha Sirigiri; Mudvari, Prakriti; Ohshiro, Kazufumi; Ghanta, Krishna Sumanth; Pakala, Suresh B.; Li, Da-Qiang; Costa, Luis; Lipton, Allan; Badwe, Rajendra A.; Fuqua, Suzanne; Wallon, Margaretha; Prendergast, George C.; Kumar, Rakesh

2013-01-01

Triple-negative breast cancer (TNBC) is characterized by the lack of expression of ERα, PR and HER-2 receptors and the pathway(s) responsible for this downregulation and thus aggressiveness, remains unknown. Here we discovered that lactoferrin (Lf) efficiently downregulates the levels of ERα, PR and HER-2 receptors in a proteasome-dependent manner in breast cancer cells, and accounts for the loss of responsiveness to ER- or HER-2- targeted therapies. Further we found that Lf increases migration and invasiveness of both non-TNBC and TNBC cell lines. We discovered that Lf directly stimulates the transcription of endothelin-1 (ET-1), a secreted pro-invasive polypeptide that acts through a specific receptor ET(A)R, leading to secretion of bioactive ET-1 peptide. Interestingly, a therapeutic ET-1 receptor antagonist drug completely blocked Lf-dependent motility and invasiveness of breast cancer cells. Physiologic significance of this newly discovered Lf-ET-1 axis in the manifestation of TNBC phenotypes is revealed by elevated plasma and tissue Lf and ET-1 levels in TNBC patients as compared to those in ER+ cases. These findings describe the first physiologically relevant polypeptide as a functional determinant of downregulating all three therapeutic receptors in breast cancer which utilizes another secreted ET-1 system to confer invasiveness. Results presented here provide proof-of-principle evidence in support of therapeutic effectiveness of ET-1 receptor antagonist to completely block the Lf-induced motility and invasiveness of the TNBC as well as non-TBNC cells, and thus, opening a remarkable opportunity to treat TNBC by targeting the Lf-ET-1 axis using an approved developmental drug. PMID:22006997

The effects of endothelin-1 on the cardiorespiratory physiology of the freshwater trout (Oncorhynchus mykiss) and the marine dogfish (Squalus acanthias).

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Perry, S F; Montpetit, C J; McKendry, J; Desforges, P R; Gilmour, K M; Wood, C M; Olson, K R

2001-11-01

The aim of the present study was to evaluate the effects of endothelin-l-elicited cardiovascular events on respiratory gas transfer in the freshwater rainbow trout (Oncorhynchus mykiss) and the marine dogfish (Squalus acanthias). In both species, endothelin-1 (666 pmol kg(-1)) caused a rapid (within 4 min) reduction (ca. 30-50 mmHg) in arterial blood partial pressure of O2. The effects of endothelin-1 on arterial blood partial pressure of CO2 were not synchronised with the changes in O2 partial pressure and the responses were markedly different in trout and dogfish. In trout, arterial CO2 partial pressure was increased transiently by approximately 1.0 mmHg but the onset of the response was delayed and occurred 12 min after endothelin-1 injection. In contrast, CO2 partial pressure remained more-or-less constant in dogfish after injection of endothelin-1 and was increased only slightly (approximately 0.1 mmHg) after 60 min. Pre-treatment of trout with bovine carbonic anhydrase (5 mg ml(-1)) eliminated the increase in CO2 partial pressure that was normally observed after endothelin-1 injection. In both species, endothelin-1 injection caused a decrease in arterial blood pH that mirrored the changes in CO2 partial pressure. Endothelin-1 injection was associated with transient (trout) or persistent (dogfish) hyperventilation as indicated by pronounced increases in breathing frequency and amplitude. In trout, arterial blood pressure remained constant or was decreased slightly and was accompanied by a transient increase in systemic resistance, and a temporary reduction in cardiac output. The decrease in cardiac output was caused solely by a reduction in cardiac frequency; cardiac stroke volume was unaffected. In dogfish, arterial blood pressure was lowered by approximately 10 mmHg at 6-10 min after endothelin-1 injection but then was rapidly restored to pre-injection levels. The decrease in arterial blood pressure reflected an increase in branchial vascular resistance (as

Endothelin-1 receptor antagonists protect the kidney against the nephrotoxicity induced by cyclosporine-A in normotensive and hypertensive rats.

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Caires, A; Fernandes, G S; Leme, A M; Castino, B; Pessoa, E A; Fernandes, S M; Fonseca, C D; Vattimo, M F; Schor, N; Borges, F T

2017-12-11

Cyclosporin-A (CsA) is an immunosuppressant associated with acute kidney injury and chronic kidney disease. Nephrotoxicity associated with CsA involves the increase in afferent and efferent arteriole resistance, decreased renal blood flow (RBF) and glomerular filtration. The aim of this study was to evaluate the effect of Endothelin-1 (ET-1) receptor blockade with bosentan (BOS) and macitentan (MAC) antagonists on altered renal function induced by CsA in normotensive and hypertensive animals. Wistar and genetically hypertensive rats (SHR) were separated into control group, CsA group that received intraperitoneal injections of CsA (40 mg/kg) for 15 days, CsA+BOS and CsA+MAC that received CsA and BOS (5 mg/kg) or MAC (25 mg/kg) by gavage for 15 days. Plasma creatinine and urea, mean arterial pressure (MAP), RBF and renal vascular resistance (RVR), and immunohistochemistry for ET-1 in the kidney cortex were measured. CsA decreased renal function, as shown by increased creatinine and urea. There was a decrease in RBF and an increase in MAP and RVR in normotensive and hypertensive animals. These effects were partially reversed by ET-1 antagonists, especially in SHR where increased ET-1 production was observed in the kidney. Most MAC effects were similar to BOS, but BOS seemed to be better at reversing cyclosporine-induced changes in renal function in hypertensive animals. The results of this work suggested the direct participation of ET-1 in renal hemodynamics changes induced by cyclosporin in normotensive and hypertensive rats. The antagonists of ET-1 MAC and BOS reversed part of these effects.

Endothelin-1 receptor antagonists protect the kidney against the nephrotoxicity induced by cyclosporine-A in normotensive and hypertensive rats

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A. Caires

2017-12-01

Full Text Available Cyclosporin-A (CsA is an immunosuppressant associated with acute kidney injury and chronic kidney disease. Nephrotoxicity associated with CsA involves the increase in afferent and efferent arteriole resistance, decreased renal blood flow (RBF and glomerular filtration. The aim of this study was to evaluate the effect of Endothelin-1 (ET-1 receptor blockade with bosentan (BOS and macitentan (MAC antagonists on altered renal function induced by CsA in normotensive and hypertensive animals. Wistar and genetically hypertensive rats (SHR were separated into control group, CsA group that received intraperitoneal injections of CsA (40 mg/kg for 15 days, CsA+BOS and CsA+MAC that received CsA and BOS (5 mg/kg or MAC (25 mg/kg by gavage for 15 days. Plasma creatinine and urea, mean arterial pressure (MAP, RBF and renal vascular resistance (RVR, and immunohistochemistry for ET-1 in the kidney cortex were measured. CsA decreased renal function, as shown by increased creatinine and urea. There was a decrease in RBF and an increase in MAP and RVR in normotensive and hypertensive animals. These effects were partially reversed by ET-1 antagonists, especially in SHR where increased ET-1 production was observed in the kidney. Most MAC effects were similar to BOS, but BOS seemed to be better at reversing cyclosporine-induced changes in renal function in hypertensive animals. The results of this work suggested the direct participation of ET-1 in renal hemodynamics changes induced by cyclosporin in normotensive and hypertensive rats. The antagonists of ET-1 MAC and BOS reversed part of these effects.

Cannabinoid receptor type-1: breaking the dogmas [version 1; referees: 3 approved

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Arnau Busquets Garcia

2016-05-01

Full Text Available The endocannabinoid system (ECS is abundantly expressed in the brain. This system regulates a plethora of physiological functions and is composed of cannabinoid receptors, their endogenous ligands (endocannabinoids, and the enzymes involved in the metabolism of endocannabinoids. In this review, we highlight the new advances in cannabinoid signaling, focusing on a key component of the ECS, the type-1 cannabinoid receptor (CB1. In recent years, the development of new imaging and molecular tools has demonstrated that this receptor can be distributed in many cell types (e.g., neuronal or glial cells and intracellular compartments (e.g., mitochondria. Interestingly, cellular and molecular effects are differentially mediated by CB1 receptors according to their specific localization (e.g., glutamatergic or GABAergic neurons. Moreover, this receptor is expressed in the periphery, where it can modulate periphery-brain connections. Finally, the better understanding of the CB1 receptor structure led researchers to propose interesting and new allosteric modulators. Thus, the advances and the new directions of the CB1 receptor field will provide new insights and better approaches to profit from its interesting therapeutic profile.

Expression of ET(A) and ET(B) receptor mRNA in human cerebral arteries

DEFF Research Database (Denmark)

Hansen-Schwartz, J; Szok, D; Edvinsson, L

2002-01-01

The vascular effects of endothelins (ET) are in mammals mediated via two receptor subtypes, endothelin A (ET(A), mainly constrictive) and endothelin B (ET(B), mainly dilating) receptors. We have examined the presence of ET(A) and ET(B) receptor mRNA using the reverse transcription polymerase chai...

The endothelin system has a significant role in the pathogenesis and progression of Mycobacterium tuberculosis infection.

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Correa, Andre F; Bailão, Alexandre M; Bastos, Izabela M D; Orme, Ian M; Soares, Célia M A; Kipnis, Andre; Santana, Jaime M; Junqueira-Kipnis, Ana Paula

2014-12-01

Tuberculosis (TB) remains a major global health problem, and although multiple studies have addressed the relationship between Mycobacterium tuberculosis and the host on an immunological level, few studies have addressed the impact of host physiological responses. Proteases produced by bacteria have been associated with important alterations in the host tissues, and a limited number of these enzymes have been characterized in mycobacterial species. M. tuberculosis produces a protease called Zmp1, which appears to be associated with virulence and has a putative action as an endothelin-converting enzyme. Endothelins are a family of vasoactive peptides, of which 3 distinct isoforms exist, and endothelin 1 (ET-1) is the most abundant and the best-characterized isoform. The aim of this work was to characterize the Zmp1 protease and evaluate its role in pathogenicity. Here, we have shown that M. tuberculosis produces and secretes an enzyme with ET-1 cleavage activity. These data demonstrate a possible role of Zmp1 for mycobacterium-host interactions and highlights its potential as a drug target. Moreover, the results suggest that endothelin pathways have a role in the pathogenesis of M. tuberculosis infections, and ETA or ETB receptor signaling can modulate the host response to the infection. We hypothesize that a balance between Zmp1 control of ET-1 levels and ETA/ETB signaling can allow M. tuberculosis adaptation and survival in the lung tissues. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Venous plasma levels of endothelin-1 are not altered immediately after nitroglycerin infusion in healthy subjects

DEFF Research Database (Denmark)

Thomsen, L L; Iversen, Helle Klingenberg; Emmeluth, C

1995-01-01

before and immediately (5-30 s) after 80 min infusion of NTG (glyceryl trinitrate) or saline in 12 healthy subjects. On two different days separated by at least 1 week, NTG in four different doses, 0.015, 0.25, 1.0, and 2.0 micrograms. kg-1. min-1, or placebo (isotonic saline) was infused successively...... for 20 min each dose. During the infusion blood pressure and heart rate were measured. NTG infusion significantly decreased systolic blood pressure from 112.4 to 103.4 mmHg and pulse pressure from 39.3 to 29.5 mmHg. Heart rate increased from 62.7 to 73.1 beats. min-1. No changes in endothelin-1 plasma...... levels were induced by NTG infusion (2.4 pg.ml-1 before NTG vs. 2.7 pg.ml-1 after NTG) and placebo infusion also did not affect plasma endothelin-1. It is concluded that venous plasma levels of endothelin-1 are not altered immediately after NTG infusion....

Endothelin, a peptide inhibitor of Na(+)-K(+)-ATPase in intact renaltubular epithelial cells

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Zeidel, M.L.; Brady, H.R.; Kone, B.C.; Gullans, S.R. (Brigham and Women' s Hospital, Boston, MA (USA))

1989-12-01

Endothelin, a potent vasoconstrictor released by vascular endothelial cells, can induce natriuresis in vivo. These studies examined the regulation of Na+ transport by endothelin in suspensions of rabbit proximal tubule (PT) and inner medullary collecting duct (IMCD) cells. Endothelin reduced oxygen consumption (QO2) by 18 +/- 1% in IMCD cells but did not alter QO2 in PT cells. In IMCD cells, endothelin inhibited QO2 half maximally at approximately 5 x 10(-12) M. Several lines of evidence indicate that endothelin reduces QO2 by inhibiting the Na(+)-K(+)-ATPase. (1) Endothelin gave no further inhibition of QO2 after ouabain and blunted the stimulatory effect of amphotericin B on QO2 (+29 +/- 4% in absence of endothelin, 0 +/- 5% in presence of endothelin; n = 6 preparations, P less than 0.001). (2) Endothelin inhibited ouabain-sensitive 86Rb+ uptake by 46.6 +/- 8.6% at 10 s and by 35.4 +/- 5.3% at 30 s without altering uptake at (60 min. 3) Addition of endothelin to IMCD cells induced a net K+ efflux with an initial rate of 32.2 +/- 4.8 nmol.min-1.mg protein-1, consistent with inhibition of the Na(+)-K(+)-ATPase. In contrast to the response observed in intact cells, in permeabilized IMCD cells endothelin did not inhibit ouabain-sensitive ATPase. Several observations indicated that prostaglandin E2 (PGE2) mediates endothelin inhibition of Na(+)-K(+)-ATPase activity. (1) The response to endothelin was blocked by ibuprofen in assays of QO2, net K+ flux, and 86Rb+ uptake. (2) Endothelin and PGE2 gave equivalent, nonadditive inhibition of ouabain-sensitive 86Rb+ uptake.

Endothelin, a peptide inhibitor of Na(+)-K(+)-ATPase in intact renaltubular epithelial cells

International Nuclear Information System (INIS)

Zeidel, M.L.; Brady, H.R.; Kone, B.C.; Gullans, S.R.

1989-01-01

Endothelin, a potent vasoconstrictor released by vascular endothelial cells, can induce natriuresis in vivo. These studies examined the regulation of Na+ transport by endothelin in suspensions of rabbit proximal tubule (PT) and inner medullary collecting duct (IMCD) cells. Endothelin reduced oxygen consumption (QO2) by 18 +/- 1% in IMCD cells but did not alter QO2 in PT cells. In IMCD cells, endothelin inhibited QO2 half maximally at approximately 5 x 10(-12) M. Several lines of evidence indicate that endothelin reduces QO2 by inhibiting the Na(+)-K(+)-ATPase. (1) Endothelin gave no further inhibition of QO2 after ouabain and blunted the stimulatory effect of amphotericin B on QO2 (+29 +/- 4% in absence of endothelin, 0 +/- 5% in presence of endothelin; n = 6 preparations, P less than 0.001). (2) Endothelin inhibited ouabain-sensitive 86Rb+ uptake by 46.6 +/- 8.6% at 10 s and by 35.4 +/- 5.3% at 30 s without altering uptake at (60 min. 3) Addition of endothelin to IMCD cells induced a net K+ efflux with an initial rate of 32.2 +/- 4.8 nmol.min-1.mg protein-1, consistent with inhibition of the Na(+)-K(+)-ATPase. In contrast to the response observed in intact cells, in permeabilized IMCD cells endothelin did not inhibit ouabain-sensitive ATPase. Several observations indicated that prostaglandin E2 (PGE2) mediates endothelin inhibition of Na(+)-K(+)-ATPase activity. (1) The response to endothelin was blocked by ibuprofen in assays of QO2, net K+ flux, and 86Rb+ uptake. (2) Endothelin and PGE2 gave equivalent, nonadditive inhibition of ouabain-sensitive 86Rb+ uptake

Contractile effects and binding properties of endothelins/sarafotoxins in the guinea pig ileum.

Science.gov (United States)

Wollberg, Z; Bdolah, A; Galron, R; Sokolovsky, M; Kochva, E

1991-05-30

Seven of the eight known isopeptides of the endothelin/sarafotoxin (ET/SRTX) family were tested on the isolated guinea pig ileum and found to cause a concentration-dependent increase in basal tone. The rate or the amplitude of the spontaneous rhythmic contractions of the ileal smooth muscle were essentially not affected by any of the peptides. The maximum contraction elicited by vasoactive intestinal contractor (VIC) was slightly stronger than that induced by endothelin-1 (ET-1) or sarafotoxin-b (SRTX-b), and significantly stronger than the maximal contractions elicited by sarafotoxin-a (SRTX-a), sarafotoxin-c (SRTX-c), or endothelin-3 (ET-3). Sarafotoxin-d (SRTX-d) caused, essentially, no contraction but a rather marked relaxation. The potencies of the various peptides to induce the increase in tension, in terms of EC50 values (cumulative effective concentrations that induce half-maximum response), ranged between 6 and 95 nM depending on the peptide. VIC, ET-1, SRTX-b and SRTX-a had similar potencies and were significantly more potent than SRTX-c and ET-3. A high concentration of SRTX-b elicited no additional response when applied to the organ bath after one of the other peptides had shown a maximal effect. Binding experiments with ileal membranes revealed similar binding properties for the various peptides. Competition with iodinated SRTX-b showed no meaningful differences between the various peptides. It is concluded that all the ET/SRTX peptides compete for the same receptor subtype in the ileum. In terms of efficacy, VIC can be considered as a full agonist of this receptor, SRTX-d is probably an antagonist, while all the other peptides behave as partial agonists.

Facial hyperalgesia due to direct action of endothelin-1 in the trigeminal ganglion of mice.

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Gomes, Lenyta Oliveira; Chichorro, Juliana Geremias; Araya, Erika Ivanna; de Oliveira, Jade; Rae, Giles Alexander

2018-03-23

This study assessed the ability of endothelin-1 (ET-1) to evoke heat hyperalgesia when injected directly into the trigeminal ganglia (TG) of mice and determined the receptors implicated in this effect. The effects of TG ET A and ET B receptor blockade on alleviation of heat hyperalgesia in a model of trigeminal neuropathic pain induced by infraorbital nerve constriction (CION) were also examined. Naive mice received an intraganglionar (i.g.) injection of ET-1 (0.3-3 pmol) or the selective ET B R agonist sarafotoxin S6c (3-30 pmol), and response latencies to ipsilateral heat stimulation were assessed before the treatment and at 1-h intervals up to 5 h after the treatment. Heat hyperalgesia induced by i.g. ET-1 or CION was assessed after i.g. injections of ET A R and ET B R antagonists (BQ-123 and BQ-788, respectively, each at 0.5 nmol). Intraganglionar ET-1 or sarafotoxin S6c injection induced heat hyperalgesia lasting 4 and 2 h, respectively. Heat hyperalgesia induced by ET-1 was attenuated by i.g. BQ-123 or BQ-788. On day 5 after CION, i.g. BQ-788 injection produced a more robust antihyperalgesic effect compared with BQ-123. ET-1 injection into the TG promotes ET A R/ET B R-mediated facial heat hyperalgesia, and both receptors are clearly implicated in CION-induced hyperalgesia in the murine TG system. © 2018 Royal Pharmaceutical Society.

Knockout of endothelial cell-derived endothelin-1 attenuates skin fibrosis but accelerates cutaneous wound healing.

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Katsunari Makino

Full Text Available Endothelin (ET-1 is known for the most potent vasoconstrictive peptide that is released mainly from endothelial cells. Several studies have reported ET-1 signaling is involved in the process of wound healing or fibrosis as well as vasodilation. However, little is known about the role of ET-1 in these processes. To clarify its mechanism, we compared skin fibrogenesis and wound repair between vascular endothelial cell-specific ET-1 knockout mice and their wild-type littermates. Bleomycin-injected fibrotic skin of the knockout mice showed significantly decreased skin thickness and collagen content compared to that of wild-type mice, indicating that bleomycin-induced skin fibrosis is attenuated in the knockout mice. The mRNA levels of transforming growth factor (TGF-β were decreased in the bleomycin-treated skin of ET-1 knockout mice. On the other hand, skin wound healing was accelerated in ET-1 knockout mice, which was indicated by earlier granulation tissue reduction and re-epithelialization in these mice. The mRNA levels of TGF-β, tumor necrosis factor (TNF-α and connective tissue growth factor (CTGF were reduced in the wound of ET-1 knockout mice. In endothelial ET-1 knockout mouse, the expression of TNF-α, CTGF and TGF-β was down-regulated. Bosentan, an antagonist of dual ET receptors, is known to attenuate skin fibrosis and accelerate wound healing in systemic sclerosis, and such contradictory effect may be mediated by above molecules. The endothelial cell-derived ET-1 is the potent therapeutic target in fibrosis or wound healing, and investigations of the overall regulatory mechanisms of these pathological conditions by ET-1 may lead to a new therapeutic approach.

Clinical variability of Waardenburg-Shah syndrome in patients with proximal 13q deletion syndrome including the endothelin-B receptor locus.

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Tüysüz, Beyhan; Collin, Anna; Arapoğlu, Müjde; Suyugül, Nezir

2009-10-01

Waardenburg-Shah syndrome (Waardenburg syndrome type IV-WS4) is an auditory-pigmentary disorder that combines clinical features of pigmentary abnormalities of the skin, hair and irides, sensorineural hearing loss, and Hirschsprung disease (HSCR). Mutations in the endothelin-B receptor (EDNRB) gene on 13q22 have been found to cause this syndrome. Mutations in both alleles cause the full phenotype, while heterozygous mutations cause isolated HSCR or HSCR with minor pigmentary anomalies and/or sensorineural deafness. We investigated the status of the EDNRB gene, by FISH analysis, in three patients with de novo proximal 13q deletions detected at cytogenetic analysis and examined the clinical variability of WS4 among these patients. Chromosome 13q was screened with locus specific FISH probes and breakpoints were determined at 13q22.1q31.3 in Patients 1 and 3, and at 13q21.1q31.3 in Patient 2. An EDNRB specific FISH probe was deleted in all three patients. All patients had common facial features seen in proximal 13q deletion syndrome and mild mental retardation. However, findings related to WS4 were variable; Patient 1 had hypopigmentation of the irides and HSCR, Patient 2 had prominent bicolored irides and mild bilateral hearing loss, and Patient 3 had only mild unilateral hearing loss. These data contribute new insights into the pathogenesis of WS4.

Endothelin-A receptor blockade slows the progression of renal injury in experimental renovascular disease.

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Kelsen, Silvia; Hall, John E; Chade, Alejandro R

2011-07-01

Endothelin (ET)-1, a potent renal vasoconstrictor with mitogenic properties, is upregulated by ischemia and has been shown to induce renal injury via the ET-A receptor. The potential role of ET-A blockade in chronic renovascular disease (RVD) has not, to our knowledge, been previously reported. We hypothesized that chronic ET-A receptor blockade would preserve renal hemodynamics and slow the progression of injury of the stenotic kidney in experimental RVD. Renal artery stenosis, a major cause of chronic RVD, was induced in 14 pigs and observed for 6 wk. In half of the pigs, chronic ET-A blockade was initiated (RVD+ET-A, 0.75 mg·kg(-1)·day(-1)) at the onset of RVD. Single-kidney renal blood flow, glomerular filtration rate, and perfusion were quantified in vivo after 6 wk using multidetector computer tomography. Renal microvascular density was quantified ex vivo using three-dimensional microcomputer tomography, and growth factors, inflammation, apoptosis, and fibrosis were determined in renal tissue. The degree of stenosis and increase in blood pressure were similar in RVD and RVD+ET-A pigs. Renal hemodynamics, function, and microvascular density were decreased in the stenotic kidney but preserved by ET-A blockade, accompanied by increased renal expression of vascular endothelial growth factor, hepatocyte growth factor, and downstream mediators such as phosphorilated-Akt, angiopoietins, and endothelial nitric oxide synthase. ET-A blockade also reduced renal apoptosis, inflammation, and glomerulosclerosis. This study shows that ET-A blockade slows the progression of renal injury in experimental RVD and preserves renal hemodynamics, function, and microvascular density in the stenotic kidney. These results support a role for ET-1/ET-A as a potential therapeutic target in chronic RVD.

β-arrestins negatively control human adrenomedullin type 1-receptor internalization.

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Kuwasako, Kenji; Kitamura, Kazuo; Nagata, Sayaka; Sekiguchi, Toshio; Danfeng, Jiang; Murakami, Manabu; Hattori, Yuichi; Kato, Johji

2017-05-27

Adrenomedullin (AM) is a potent hypotensive peptide that exerts a powerful variety of protective effects against multiorgan damage through the AM type 1 receptor (AM 1 receptor), which consists of the calcitonin receptor-like receptor (CLR) and receptor activity-modifying protein 2 (RAMP2). Two β-arrestin (β-arr) isoforms, β-arr-1 and β-arr-2, play a central role in the agonist-induced internalization of many receptors for receptor resensitization. Notably, β-arr-biased agonists are now being tested in phase II clinical trials, targeting acute pain and acute heart failure. Here, we examined the effects of β-arr-1 and β-arr-2 on human AM 1 receptor internalization. We constructed a V5-tagged chimera in which the cytoplasmic C-terminal tail (C-tail) of CLR was replaced with that of the β 2 -adrenergic receptor (β 2 -AR), and it was transiently transfected into HEK-293 cells that stably expressed RAMP2. The cell-surface expression and internalization of the wild-type or chimeric receptor were quantified by flow cytometric analysis. The [ 125 I]AM binding and the AM-induced cAMP production of these receptors were also determined. Surprisingly, the coexpression of β-arr-1 or -2 resulted in significant decreases in AM 1 receptor internalization without affecting AM binding and signaling prior to receptor internalization. Dominant-negative (DN) β-arr-1 or -2 also significantly decreased AM-induced AM 1 receptor internalization. In contrast, the AM-induced internalization of the chimeric AM 1 receptor was markedly augmented by the cotransfection of β-arr-1 or -2 and significantly reduced by the coexpression of DN-β-arr-1 or -2. These results were consistent with those seen for β 2 -AR. Thus, both β-arrs negatively control AM 1 receptor internalization, which depends on the C-tail of CLR. Copyright © 2017 Elsevier Inc. All rights reserved.

Plasma endothelin-1 and tumor necrosis factor-alpha concentrations in pregnant and cyclic rats after low-dose endotoxin infusion

NARCIS (Netherlands)

Faas, MM; Bakker, WW; Valkhof, N; Baller, JFW; Schuiling, GA

Plasma endothelin-1 and tumor necrosis factor-alpha were determined in pregnant and cyclic rats after infusion of either endotoxin (1.0 mu g/kg of body weight) or saline solution. After endotoxin, but not after saline solution, administration there was a transient endothelin-1 response in pregnant

Protein kinase mediated upregulation of endothelin A, endothelin B and 5-hydroxytryptamine 1B/1D receptors during organ culture in rat basilar artery

DEFF Research Database (Denmark)

Hansen-Schwartz, Jacob; Svensson, Carl-Lennart; Xu, Cang-Bao

2002-01-01

with ET-1 (unspecific ET(A) and ET(B) agonist), S6c (specific ET(B) agonist) and 5-CT (5-HT(1) agonist). Levels of mRNA coding for the ET(A), ET(B), 5-HT(1B) and 5-HT(1D) receptors were analysed using real-time RT-PCR. 3. Classical PKC's are critically involved in the appearance of the ET(B) receptor; co....... 2. The effect of inhibiting protein kinases during organ culture with staurosporine (unspecific protein kinase inhibitor), RO 31-7549 (specific inhibitor of classical PKC's) and H 89 (specific inhibitor of PKA) was examined using in vitro pharmacological examination of cultured vessel segments......-culture with RO 31-7549 abolished the contractile response (6.9 +/- 1.8%) and reduced the ET(B) receptor mRNA by 44 +/- 4% as compared to the cultured control. Correlation between decreased ET(B) receptor mRNA and abolished contractile function indicates upstream involvement of PKC. 4. Inhibition of PKA generally...

Plasma Endothelin-1 Levels in Preterm Neonatal Infants with Acute Respiratory Failure

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D. V. Dmitriyev

2008-01-01

Full Text Available Increased pulmonary vascular resistance in preterm infants is associated with acute respiratory failure (ARF and at the same time endothelin-1 (E-1 plays an important role in neonatal pulmonary vascular responsiveness. Methods. Endothelin-1 levels were measured in two blood samples in 12 preterm infants with ARF and in 12 controls (at 32.2±1.3 and 29.8±1.2 weeks of gestation, respectively by enzyme immunoassay. For this, the first and second blood samples were taken at 18 to 40 hours after birth. Results. The plasma level of E-1 in the first sample did not differ between the neonates of both groups. In the second sample, significantly higher E-1 concentrations were observed in the newborns with ARF than in the controls. In the first sample, E-1 concentration were higher than in the second one in both groups (p<0.001. There was a significant positive correlation between the second E-1 sample and the SNAPPE 2 scale rating (r=0.38; p=0.02. The plasma level of E-1 in the first sample did not differ in both groups (11.9 and 12.2 pg/ml, respectively. Conclusion. Neonates with and without ARF had the similar plasma E-1 levels in the first sample, by taking into account the fact that the E-1 levels were higher in ARF than in the controls at 18 to 40 hour after birth. Increased vascular resistance in ARF may be associated with the high level of E-1. Key words: endothe-lin-1, acute respiratory failure.

β-arrestins negatively control human adrenomedullin type 1-receptor internalization

International Nuclear Information System (INIS)

Kuwasako, Kenji; Kitamura, Kazuo; Nagata, Sayaka; Sekiguchi, Toshio; Danfeng, Jiang; Murakami, Manabu; Hattori, Yuichi; Kato, Johji

2017-01-01

Adrenomedullin (AM) is a potent hypotensive peptide that exerts a powerful variety of protective effects against multiorgan damage through the AM type 1 receptor (AM 1 receptor), which consists of the calcitonin receptor-like receptor (CLR) and receptor activity-modifying protein 2 (RAMP2). Two β-arrestin (β-arr) isoforms, β-arr-1 and β-arr-2, play a central role in the agonist-induced internalization of many receptors for receptor resensitization. Notably, β-arr-biased agonists are now being tested in phase II clinical trials, targeting acute pain and acute heart failure. Here, we examined the effects of β-arr-1 and β-arr-2 on human AM 1 receptor internalization. We constructed a V5-tagged chimera in which the cytoplasmic C-terminal tail (C-tail) of CLR was replaced with that of the β 2 -adrenergic receptor (β 2 -AR), and it was transiently transfected into HEK-293 cells that stably expressed RAMP2. The cell-surface expression and internalization of the wild-type or chimeric receptor were quantified by flow cytometric analysis. The [ 125 I]AM binding and the AM-induced cAMP production of these receptors were also determined. Surprisingly, the coexpression of β-arr-1 or -2 resulted in significant decreases in AM 1 receptor internalization without affecting AM binding and signaling prior to receptor internalization. Dominant-negative (DN) β-arr-1 or -2 also significantly decreased AM-induced AM 1 receptor internalization. In contrast, the AM-induced internalization of the chimeric AM 1 receptor was markedly augmented by the cotransfection of β-arr-1 or -2 and significantly reduced by the coexpression of DN-β-arr-1 or -2. These results were consistent with those seen for β 2 -AR. Thus, both β-arrs negatively control AM 1 receptor internalization, which depends on the C-tail of CLR. - Highlights: • We found that β-arrestins 1 and 2 negatively control agonist-induced GPCR internalization. • β-arrestins 1 and 2 significantly inhibits the AM

Endothelin-1 and -3 plasma concentrations in patients with cirrhosis: role of splanchnic and renal passage and liver function

DEFF Research Database (Denmark)

Gerbes, A L; Møller, S; Gülberg, V

1995-01-01

of splanchnic and renal passage and of liver function on plasma concentrations of endothelin-1 (ET-1) and endothelin-3 (ET-3) in patients with cirrhosis compared with controls. Eighteen patients with cirrhosis and 8 normotensive controls of similar age were investigated. Arterial and venous plasma samples were...

Agonist-dependent effects of mutations in the sphingosine-1-phosphate type 1 receptor

NARCIS (Netherlands)

van Loenen, Pieter B.; de Graaf, Chris; Verzijl, Dennis; Leurs, Rob; Rognan, Didier; Peters, Stephan L. M.; Alewijnse, Astrid E.

2011-01-01

The sphingosine-1-phosphate type 1 (S1P(1)) receptor is a new target in the treatment of auto-immune diseases as evidenced by the recent approval of FTY720 (Fingolimod). The ligand-binding pocket of the S1P(1) receptor has been generally characterised but detailed insight into ligand-specific

The endothelin ET(B) receptor agonist [125I]BQ-3020 binds predominantly to nerves in the bovine retractor penis muscle and penile artery.

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Parkkisenniemi, U M; Palkama, A; Virtanen, I; Klinge, E

2000-11-01

Preliminary pharmacological experiments have suggested that in the bovine retractor penis muscle there are relaxation-mediating endothelin ET(B) receptors, at least part of which are located on the inhibitory nitrergic nerves. The present work was undertaken to test this hypothesis by means of receptor autoradiography and additional pharmacological experiments. In the retractor penis muscle and the penile artery, specific binding of the ETB receptor-selective agonist [125I]BQ-3020 took place predominantly to nerve trunks and minor nerve branches. The situation was the same in the dorsal metatarsal artery, that was included as a reference because of its different innervation. Throughout the nerves the silver grains were evenly distributed over the nuclei of Schwann cells and the spaces between them. In the retractor penis there was also a small amount of specific binding to smooth muscle. No specific endothelial binding was observed in any of the tissues examined. The pharmacological studies confirmed that the relaxation of the retractor penis muscle induced by the ET(B) receptor-selective agonist, sarafotoxin S6c, is susceptible to tetrodotoxin as well as to inhibition of nitric oxide synthase. The relaxation was also characterized by inconsistency, weakness and tachyphylaxis. The electrical field stimulation-induced submaximal relaxation of the retractor penis was unaffected by stimulation or blockade of ET(B) receptors. The autoradiography suggests that in all the three bovine tissues studied there are ET(B) receptors located on nerves independently of the type of efferent nerve. The pharmacological experiments do not support the concept that in the bovine retractor penis muscle neuronal ET(B) receptors exert important immediate effects on the functioning of the penile erection-mediating nitrergic nerves.

Design and Rationale for the Endothelin-1 Receptor Antagonism in the Prevention of Microvascular Injury in Patients with non-ST Elevation Acute Coronary Syndrome Undergoing Percutaneous Coronary Intervention (ENDORA-PCI) Trial.

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Liou, Kevin; Jepson, Nigel; Buckley, Nicolas; Chen, Vivien; Thomas, Shane; Russell, Elizabeth Anne; Ooi, Sze-Yuan

2016-04-01

Peri-procedural myocardial infarction (PMI) occurs in a small but significant portion of patients undergoing percutaneous intervention (PCI). The underlying mechanisms are complex and may include neurohormonal activation and release of vasoactive substances resulting in disruption of the coronary microcirculation. Endothelin in particular has been found in abundance in atherosclerotic plaques and in systemic circulation following PCI, and may be a potential culprit for PMI through its action on microvascular vasoconstriction, and platelet and neutrophil activation. In this study we aim to characterize the behavior of the coronary microcirculation during a PCI with the index of microvascular resistance (IMR) and the effect of peri-procedural endothelin antagonism. The ENDORA-PCI trial is a randomized, double-blind, placebo-controlled, single-center clinical trial designed to evaluate the efficacy of endothelin antagonism in attenuating the peri-procedural rise in IMR as a surrogate marker for PMI. The patients of interest are those with non-ST elevation acute coronary syndrome (NSTEACS) undergoing PCI, and we aim to recruit 52 patients overall to give the study a power of 80 % at an α level of 5 %. Patients will be randomized in a 1:1 fashion to either Ambrisentan, an endothelin antagonist, or placebo, prior to their PCI. IMR will be measured before and after PCI. The primary endpoint is the difference in peri-procedural changes in patients' IMR between the two groups. The ENDORA-PCI study will investigate whether endothelin antagonism with Ambrisentan attenuates the peri-procedural rise in IMR in patients with NSTEACS undergoing PCI, and thus potentially the risk of PMI.

The changes in plasma endothelin after dosing intervention in type 2 diabetes and its clinical significance

International Nuclear Information System (INIS)

Yang Xixiu; Sun Jinfeng; Li Lusheng; Wang Shufang; Zhao Xin

2002-01-01

To explore the correlation of endothelin (ET), insulin resistance and microvascular complications in type 2 diabetes, the serum concentrations of OGTT, INS, C-P and plasma ET were measured by radioimmunoassay in 30 normal subjects and 82 patients with type 2 diabetes. ET level had a linear negative correlationship with IAI. The level of ET were significantly greater in group with microangiopathy than in group without microangiopathy (P<0.01). Insulin sensitivity are strongly correlated with vascular endothelial cells. The intervention may play an important role in decreasing insulin resistance of type 2 diabetes, and it is a vascular complications

Low levels of plasma endothelin-1 in patients with retinitis pigmentosa

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Hiroshi Ohguro

2010-06-01

Full Text Available Hiroshi Ohguro1, Yukihiko Mashima2, Mitsuru Nakazawa31Department of Ophthalmology, Sapporo Medical University School of Medicine, 2Department of Ophthalmology, Keio University School of Medicine, 3Department of Ophthalmology, Hirosaki University School of Medicine, JapanPurpose: The aim of this study was to elucidate the role of endothelin-1 (ET-1 in the pathophysiology of retinitis pigmentosa (RP.Methods: Plasma ET-1 levels and ophthalmic features in 50 RP patients were compared with those in 20 healthy-eye control subjects. Plasma ET-1 concentrations were determined using a commercially available enzyme-linked immunosorbent assay kit.Results: Mean plasma ET-1 levels of RP patients (1.88 ± 0.56 pg/mL were significantly lower than those of control subjects (2.30 ± 0.30 pg/mL, Mann-Whitney’s U test; P < 0.01. However, ET-1 concentrations varied markedly in each patient. Among RP patients, a significant correlation of ET-1 concentrations was not observed in terms of its hereditary forms or other clinical factors.Conclusion: ET-1 may be important in the pathogenesis of RP, and measurement of its plasma concentrations may also contribute to additional insights into the retinal hemodynamics of RP.Keywords: endothelin-1, retinitis pigmentosa, retinal hemodynamics

Angiotensin-II type 1 receptor gene polymorphism and diabetic microangiopathy

DEFF Research Database (Denmark)

Tarnow, L; Cambien, Francois; Rossing, P

1996-01-01

with proliferative retinopathy and without diabetic retinopathy was found either: 77 (50%) / 66 (42%) / 13 (8%) vs. 42 (63%) / 22 (33%) / 3 (4%) had AA/AC/CC genotypes, respectively. CONCLUSIONS: The A1166-->C polymorphism in the angiotensin-II type 1 receptor gene does not contribute to the genetic susceptibility...... is present particularly in vascular smooth muscle cells, myocardium and the kidney. A transversion of adenine to cytosine at nucleotide position 1166 in the gene coding for the angiotensin-II type 1 receptor has been associated with hypertension in the non-diabetic population. METHODS: We studied...... the relationship between the A1166-->C polymorphism in the angiotensin-II type 1 receptor gene in patients with insulin dependent diabetes mellitus (IDDM) and diabetic nephropathy (121 men, 77 women, age 41 +/- 10 years, diabetes duration 27 +/- 8 years) and in IDDM patients with normoalbuminuria (116 men, 74...

Impact of endothelin blockade on acute exercise-induced changes in blood flow and endothelial function in type 2 diabetes mellitus.

NARCIS (Netherlands)

Schreuder, T.H.A.; Lotringen, J.H. van; Hopman, M.T.E.; Thijssen, D.H.J.

2014-01-01

Positive vascular effects of exercise training are mediated by acute increases in blood flow. Type 2 diabetes patients show attenuated exercise-induced increases in blood flow, possibly mediated by the endothelin pathway, preventing an optimal stimulus for vascular adaptation. We examined the impact

Polymorphisms in nitric oxide synthase and endothelin genes among children with obstructive sleep apnea.

Science.gov (United States)

Chatsuriyawong, Siriporn; Gozal, David; Kheirandish-Gozal, Leila; Bhattacharjee, Rakesh; Khalyfa, Ahamed A; Wang, Yang; Sukhumsirichart, Wasana; Khalyfa, Abdelnaby

2013-09-06

Obstructive sleep apnea (OSA) is associated with adverse and interdependent cognitive and cardiovascular consequences. Increasing evidence suggests that nitric oxide synthase (NOS) and endothelin family (EDN) genes underlie mechanistic aspects of OSA-associated morbidities. We aimed to identify single nucleotide polymorphisms (SNPs) in the NOS family (3 isoforms), and EDN family (3 isoforms) to identify potential associations of these SNPs in children with OSA. A pediatric community cohort (ages 5-10 years) enriched for snoring underwent overnight polysomnographic (NPSG) and a fasting morning blood draw. The diagnostic criteria for OSA were an obstructive apnea-hypopnea Index (AHI) >2/h total sleep time (TST), snoring during the night, and a nadir oxyhemoglobin saturation DNA from peripheral blood was extracted and allelic frequencies were assessed for, NOS1 (209 SNPs), NOS2 (122 SNPs), NOS3 (50 SNPs), EDN1 (43 SNPs), EDN2 (48 SNPs), EDN3 (14 SNPs), endothelin receptor A, EDNRA, (27 SNPs), and endothelin receptor B, EDNRB (23 SNPs) using a custom SNPs array. The relative frequencies of NOS-1,-2, and -3, and EDN-1,-2,-3,-EDNRA, and-EDNRB genotypes were evaluated in 608 subjects [128 with OSA, and 480 without OSA (NOSA)]. Furthermore, subjects with OSA were divided into 2 subgroups: OSA with normal endothelial function (OSA-NEF), and OSA with endothelial dysfunction (OSA-ED). Linkage disequilibrium was analyzed using Haploview version 4.2 software. For NOSA vs. OSA groups, 15 differentially distributed SNPs for NOS1 gene, and 1 SNP for NOS3 emerged, while 4 SNPs for EDN1 and 1 SNP for both EDN2 and EDN3 were identified. However, in the smaller sub-group for whom endothelial function was available, none of the significant SNPs was retained due to lack of statistical power. Differences in the distribution of polymorphisms among NOS and EDN gene families suggest that these SNPs could play a contributory role in the pathophysiology and risk of OSA-induced cardiovascular

Correlation between plasma endothelin-1 levels and severity of septic liver failure quantified by maximal liver function capacity (LiMAx test. A prospective study.

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Magnus F Kaffarnik

Full Text Available To investigate the relationship between the degree of liver dysfunction, quantified by maximal liver function capacity (LiMAx test and endothelin-1, TNF-α and IL-6 in septic surgical patients.28 septic patients (8 female, 20 male, age range 35-80y were prospectively investigated on a surgical intensive care unit. Liver function, defined by LiMAx test, and measurements of plasma levels of endothelin-1, TNF-α and IL-6 were carried out within the first 24 hours after onset of septic symptoms, followed by day 2, 5 and 10. Patients were divided into 2 groups (group A: LiMAx ≥100 μg/kg/h, moderate liver dysfunction; group B: LiMAx <100 μg/kg/h, severe liver dysfunction for analysis and investigated regarding the correlation between endothelin-1 and the severity of liver failure, quantified by LiMAx test.Group B showed significant higher results for endothelin-1 than patients in group A (P = 0.01, d5; 0.02, d10. For TNF-α, group B revealed higher results than group A, with a significant difference on day 10 (P = 0.005. IL-6 showed a non-significant trend to higher results in group B. The Spearman's rank correlation coefficient revealed a significant correlation between LiMAx and endothelin-1 (-0.434; P <0.001, TNF-α (-0.515; P <0.001 and IL-6 (-0.590; P <0.001.Sepsis-related hepatic dysfunction is associated with elevated plasma levels of endothelin-1, TNF-α and IL-6. Low LiMAx results combined with increased endothelin-1 and TNF-α and a favourable correlation between LiMAx and cytokine values support the findings of a crucial role of Endothelin-1 and TNF-α in development of septic liver failure.

Selectivity and specificity of sphingosine-1-phosphate receptor ligands: caveats and critical thinking in characterizing receptor-mediated effects.

Science.gov (United States)

Salomone, Salvatore; Waeber, Christian

2011-01-01

Receptors for sphingosine-1-phosphate (S1P) have been identified only recently. Their medicinal chemistry is therefore still in its infancy, and few selective agonists or antagonists are available. Furthermore, the selectivity of S1P receptor agonists or antagonists is not well established. JTE-013 and BML-241 (also known as CAY10444), used extensively as specific S1P(2) and S1P(3) receptors antagonists respectively, are cases in point. When analyzing S1P-induced vasoconstriction in mouse basilar artery, we observed that JTE-013 inhibited not only the effect of S1P, but also the effect of U46619, endothelin-1 or high KCl; JTE-013 strongly inhibited responses to S1P in S1P(2) receptor knockout mice. Similarly, BML-241 has been shown to inhibit increases in intracellular Ca(2+) concentration via P(2) receptor or α(1A)-adrenoceptor stimulation and α(1A)-adrenoceptor-mediated contraction of rat mesenteric artery, while it did not affect S1P(3)-mediated decrease of forskolin-induced cyclic AMP accumulation. Another putative S1P(1/3) receptor antagonist, VPC23019, does not inhibit S1P(3)-mediated vasoconstriction. With these examples in mind, we discuss caveats about relying on available pharmacological tools to characterize receptor subtypes.

Selectivity and specificity of sphingosine-1-phosphate receptor ligands: caveats and critical thinking in characterizing receptor-mediated effects

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Christian eWaeber

2011-02-01

Full Text Available Receptors for sphingosine-1-phosphate (S1P have been identified only recently. Their medicinal chemistry is therefore still in its infancy, and few selective agonists or antagonists are available. Furthermore, the selectivity of S1P receptor agonists or antagonists is not well established. JTE-013 and BML-241 (also known as CAY10444, used extensively as specific S1P2 and S1P3 receptors antagonists respectively, are cases in point. When analyzing S1P-induced vasoconstriction in mouse basilar artery, we observed that JTE-013 inhibited not only the effect of S1P, but also the effect of U46619, endothelin-1 or high KCl; JTE-013 strongly inhibited responses to S1P in S1P2 receptor knockout mice. Similarly, BML-241 has been shown to inhibit increases in intracellular Ca2+ concentration via P2 receptor or α1A-adrenoceptor stimulation and α1A-adrenoceptor-mediated contraction of rat mesenteric artery, while it did not affect S1P3-mediated decrease of forskolin-induced cyclic AMP accumulation. Another putative S1P1/3 receptor antagonist, VPC23019, does not inhibit S1P3-mediated vasoconstriction. With these examples in mind, we discuss caveats about relying on available pharmacological tools to characterize receptor subtypes.

PeaTAR1B: Characterization of a Second Type 1 Tyramine Receptor of the American Cockroach, Periplaneta americana.

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Blenau, Wolfgang; Balfanz, Sabine; Baumann, Arnd

2017-10-30

The catecholamines norepinephrine and epinephrine regulate important physiological functions in vertebrates. In insects; these neuroactive substances are functionally replaced by the phenolamines octopamine and tyramine. Phenolamines activate specific guanine nucleotide-binding (G) protein-coupled receptors (GPCRs). Type 1 tyramine receptors are better activated by tyramine than by octopamine. In contrast; type 2 tyramine receptors are almost exclusively activated by tyramine. Functionally; activation of type 1 tyramine receptors leads to a decrease in the intracellular concentration of cAMP ([cAMP] i ) whereas type 2 tyramine receptors can mediate Ca 2+ signals or both Ca 2+ signals and effects on [cAMP] i . Here; we report that the American cockroach ( Periplaneta americana ) expresses a second type 1 tyramine receptor (PeaTAR1B) in addition to PeaTAR1A (previously called PeaTYR1). When heterologously expressed in flpTM cells; activation of PeaTAR1B by tyramine leads to a concentration-dependent decrease in [cAMP] i . Its activity can be blocked by a series of established antagonists. The functional characterization of two type 1 tyramine receptors from P. americana ; PeaTAR1A and PeaTAR1B; which respond to tyramine by changing cAMP levels; is a major step towards understanding the actions of tyramine in cockroach physiology and behavior; particularly in comparison to the effects of octopamine.

PeaTAR1B: Characterization of a Second Type 1 Tyramine Receptor of the American Cockroach, Periplaneta americana

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Wolfgang Blenau

2017-10-01

Full Text Available The catecholamines norepinephrine and epinephrine regulate important physiological functions in vertebrates. In insects; these neuroactive substances are functionally replaced by the phenolamines octopamine and tyramine. Phenolamines activate specific guanine nucleotide-binding (G protein-coupled receptors (GPCRs. Type 1 tyramine receptors are better activated by tyramine than by octopamine. In contrast; type 2 tyramine receptors are almost exclusively activated by tyramine. Functionally; activation of type 1 tyramine receptors leads to a decrease in the intracellular concentration of cAMP ([cAMP]i whereas type 2 tyramine receptors can mediate Ca2+ signals or both Ca2+ signals and effects on [cAMP]i. Here; we report that the American cockroach (Periplaneta americana expresses a second type 1 tyramine receptor (PeaTAR1B in addition to PeaTAR1A (previously called PeaTYR1. When heterologously expressed in flpTM cells; activation of PeaTAR1B by tyramine leads to a concentration-dependent decrease in [cAMP]i. Its activity can be blocked by a series of established antagonists. The functional characterization of two type 1 tyramine receptors from P. americana; PeaTAR1A and PeaTAR1B; which respond to tyramine by changing cAMP levels; is a major step towards understanding the actions of tyramine in cockroach physiology and behavior; particularly in comparison to the effects of octopamine.

Preservation of endothelium-dependent relaxation in atherosclerotic mice with endothelium-restricted endothelin-1 overexpression.

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Mian, Muhammad Oneeb Rehman; Idris-Khodja, Noureddine; Li, Melissa W; Leibowitz, Avshalom; Paradis, Pierre; Rautureau, Yohann; Schiffrin, Ernesto L

2013-10-01

In human atherosclerosis, which is associated with elevated plasma and coronary endothelin (ET)-1 levels, ETA receptor antagonists improve coronary endothelial function. Mice overexpressing ET-1 specifically in the endothelium (eET-1) crossed with atherosclerosis-prone apolipoprotein E knockout mice (Apoe(-/-)) exhibit exaggerated high-fat diet (HFD)-induced atherosclerosis. Since endothelial dysfunction often precedes atherosclerosis development, we hypothesized that mice overexpressing endothelial ET-1 on a genetic background deficient in apolipoprotein E (eET-1/Apoe(-/-)) would have severe endothelial dysfunction. To test this hypothesis, we investigated endothelium-dependent relaxation (EDR) to acetylcholine in eET-1/Apoe(-/-) mice. EDR in mesenteric resistance arteries from 8- and 16-week-old mice fed a normal diet or HFD was improved in eET-1/Apoe(-/-) compared with Apoe(-/-) mice. Nitric oxide synthase (NOS) inhibition abolished EDR in Apoe(-/-). EDR in eET-1/Apoe(-/-) mice was resistant to NOS inhibition irrespective of age or diet. Inhibition of cyclooxygenase, the cytochrome P450 pathway, and endothelium-dependent hyperpolarization (EDH) resulted in little or no inhibition of EDR in eET-1/Apoe(-/-) compared with wild-type (WT) mice. In eET-1/Apoe(-/-) mice, blocking of EDH or soluble guanylate cyclase (sGC), in addition to NOS inhibition, decreased EDR by 36 and 30%, respectively. The activation of 4-aminopyridine-sensitive voltage-dependent potassium channels (Kv) during EDR was increased in eET-1/Apoe(-/-) compared with WT mice. We conclude that increasing eET-1 in mice that develop atherosclerosis results in decreased mutual dependence of endothelial signaling pathways responsible for EDR, and that NOS-independent activation of sGC and increased activation of Kv are responsible for enhanced EDR in this model of atherosclerosis associated with elevated endothelial and circulating ET-1.

Myoendothelial coupling in the mesenteric arterial bed; segmental differences and interplay between nitric oxide and endothelin-1

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Hilgers, RHP; De Mey, JGR

2009-01-01

Background and purpose: We tested the hypothesis that activated arterial smooth muscle (ASM) stimulates endothelial vasomotor influences via gap junctions and that the significance of this myoendothelial coupling increases with decreasing arterial diameter. Experimental approach: From WKY rats, first-, second-, third-and fourth-order branches of the superior mesenteric artery (MA1, MA2, MA3 and MA4 respectively) were isolated and mounted in wire-myographs to record vasomotor responses to 0.16–20 µmol·L−1 phenylephrine. Key results: Removal of endothelium increased the sensitivity (pEC50) to phenylephrine in all arteries. The nitric oxide (NO) synthase inhibitor Nω-nitro-L-arginine methyl ester (L-NAME) (100 µmol·L−1) did not modify pEC50 to phenylephrine in all denuded arteries, and increased it in intact MA1, MA2 and MA3 to the same extent as denudation. However, in intact MA4, the effect of L-NAME was significantly larger (ΔpEC50 0.57 ± 0.02) than the effect of endothelium removal (ΔpEC50 0.20 ± 0.06). This endothelium-dependent effect of L-NAME in MA4 was inhibited by (i) steroidal and peptidergic uncouplers of gap junctions; (ii) a low concentration of the NO donor sodium nitroprusside; and (iii) by the endothelin-receptor antagonist bosentan. It was also observed during contractions induced by (i) calcium channel activation (BayK 8644, 0.001–1 µmol·L−1); (ii) depolarization (10–40 mmol·L−1 K+); and (iii) sympathetic nerve stimulation (0.25–32 Hz). Conclusions and implications: These pharmacological observations indicated feedback control by endothelium of ASM reactivity involving gap junctions and a balance between endothelium-derived NO and endothelin-1. This myoendothelial coupling was most prominent in distal resistance arteries. PMID:19302591

Vascular reactivity of mesenteric arteries and veins to endothelin-1 in a murine model of high blood pressure.

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Pérez-Rivera, Alex A; Fink, Gregory D; Galligan, James J

2005-06-01

We characterized vascular reactivity to endothelin-1 (ET-1) in mesenteric vessels from DOCA-salt hypertensive and SHAM control mice and assessed the effect that endothelial-derived vasodilators have on ET-1-induced vasoconstriction. Changes in the diameter of unpressurized small mesenteric arteries and veins (100- to 300-microm outside diameter) were measured in vitro using computer-assisted video microscopy. Veins were more sensitive than arteries to the contractile effects of ET-1. There was a decrease in arterial maximal responses (E(max)) compared to veins, this effect was larger in DOCA-salt arteries. The selective ET(B) receptor agonist, sarafotoxin 6c (S6c), contracted DOCA-salt and SHAM veins but did not contract arteries. The ET(B) receptor antagonist, BQ-788 (100 nM), but not the ET(A) receptor antagonist, BQ-610 (100 nM), blocked S6c responses. BQ-610 partially inhibited responses to ET-1 in mesenteric veins from DOCA-salt and SHAM mice while BQ-788 did not affect responses to ET-1. Co-administration of both antagonists inhibited responses to ET-1 to a greater extent than BQ-610 alone suggesting a possible functional interaction between ET(A) and ET(B) receptors. Responses to ET-1 in mesenteric arteries were completely inhibited by BQ-610 while BQ-788 did not affect arterial responses. Nitric oxide synthase inhibition potentiated ET-1 responses in veins from SHAM but not DOCA-salt mice. There was a prominent role for ET-mediated nitric oxide release in DOCA-salt but not SHAM arteries. In summary, these studies showed a differential regulation of ET-1 contractile mechanisms between murine mesenteric arteries and veins.

Endothelin-1 Regulation of exercise-induced changes in flow: Dynamic regulation of vascular tone

NARCIS (Netherlands)

Rapoport, R.M. (Robert M.); D. Merkus (Daphne)

2017-01-01

textabstractAlthough endothelin (ET)-1 is a highly potent vasoconstrictor with considerable efficacy in numerous vascular beds, the role of endogenous ET-1 in the regulation of vascular tone remains unclear. The perspective that ET-1 plays little role in the on-going regulation of vascular tone at

Neurosensory changes in a human model of endothelin-1 induced pain: a behavioral study

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Hans, Guy; Deseure, Kristof; Robert, Dominique; de Hert, Stefan

2007-01-01

Although pain is a frequent feature in patients with cancer, its etiology is still poorly understood. In recent years, endothelin-1 (ET-1) has become a major target molecule in the etiology of cancer pain. In this randomised, double-blind study the effects of intradermal injection of ET-1 on

Interleukin-1-receptor antagonist in type 2 diabetes mellitus

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Larsen, Claus M; Faulenbach, Mirjam; Vaag, Allan

2007-01-01

BACKGROUND: The expression of interleukin-1-receptor antagonist is reduced in pancreatic islets of patients with type 2 diabetes mellitus, and high glucose concentrations induce the production of interleukin-1beta in human pancreatic beta cells, leading to impaired insulin secretion, decreased cell...... proliferation, and apoptosis. METHODS: In this double-blind, parallel-group trial involving 70 patients with type 2 diabetes, we randomly assigned 34 patients to receive 100 mg of anakinra (a recombinant human interleukin-1-receptor antagonist) subcutaneously once daily for 13 weeks and 36 patients to receive...... placebo. At baseline and at 13 weeks, all patients underwent an oral glucose-tolerance test, followed by an intravenous bolus of 0.3 g of glucose per kilogram of body weight, 0.5 mg of glucagon, and 5 g of arginine. In addition, 35 patients underwent a hyperinsulinemic-euglycemic clamp study. The primary...

The future of type 1 cannabinoid receptor allosteric ligands.

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Alaverdashvili, Mariam; Laprairie, Robert B

2018-02-01

Allosteric modulation of the type 1 cannabinoid receptor (CB1R) holds great therapeutic potential. This is because allosteric modulators do not possess intrinsic efficacy, but instead augment (positive allosteric modulation) or diminish (negative allosteric modulation) the receptor's response to endogenous ligand. Consequently, CB1R allosteric modulators have an effect ceiling which allows for the tempering of CB1R signaling without the desensitization, tolerance, dependence, and psychoactivity associated with orthosteric compounds. Pain, movement disorders, epilepsy, obesity are all potential therapeutic targets for CB1R allosteric modulation. Several challenges exist for the development of CB1R allosteric modulators, such as receptor subtype specificity, translation to in vivo systems, and mixed allosteric/agonist/inverse agonist activity. Despite these challenges, elucidation of crystal structures of CB1R and compound design based on structure-activity relationships will advance the field. In this review, we will cover recent progress for CB1R allosteric modulators and discuss the future promise of this research.

Elevated endothelin-1 (ET-1) levels may contribute to hypoadiponectinemia in childhood obesity.

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Nacci, Carmela; Leo, Valentina; De Benedictis, Leonarda; Carratù, Maria Rosaria; Bartolomeo, Nicola; Altomare, Maria; Giordano, Paola; Faienza, Maria Felicia; Montagnani, Monica

2013-04-01

Pediatric obesity is associated with endothelial dysfunction and hypoadiponectinemia, but the relationship between these two conditions remains to be fully clarified. Whether enhanced release of endothelin-1 (ET-1) may directly impair adiponectin (Ad) production in obese children is not known. The aim of the study was to explore whether and how high circulating levels of ET-1 may contribute to impair Ad production, release, and vascular activity. Sixty children were included into obese (Ob; n = 30), overweight (OW; n = 11), and lean (n = 19) groups. Total and high-molecular-weight Ad, ET-1, vascular cell adhesion molecule-1, and von Willebrand factor levels were measured in serum samples. Adipocytes were stimulated with exogenous ET-1 or with sera from lean, OW, and Ob, and Ad production and release measured in the absence or in the presence of ETA (BQ-123) and ETB (BQ-788) receptor blockers, p42/44 MAPK inhibitor PD-98059, or c-Jun NH2-terminal protein kinase inhibitor SP-600125. Vasodilation to Ad was evaluated in rat isolated arteries in the absence or in the presence of BQ-123/788. Total and high-molecular-weight Ad was significantly decreased and ET-1 levels significantly increased in OW (P ET-1. Exposure of adipocytes to exogenous ET-1 or serum from OW and Ob significantly decreased Ad mRNA and protein levels (P ET-1 on Ad was reverted by BQ-123/788 or PD-98059 but not SP-600125. Ad-mediated vasodilation was further increased in arteries pretreated with BQ-123/788. ET-1-mediated inhibition of Ad synthesis via p42/44 MAPK signaling may provide a possible explanation for hypoadiponectinemia in pediatric obesity and contribute to the development of cardiovascular complications.

Chronic Blockade of Brain Endothelin Receptor Type-A (ETA Reduces Blood Pressure and Prevents Catecholaminergic Overactivity in the Right Olfactory Bulb of DOCA-Salt Hypertensive Rats

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Luis R. Cassinotti

2018-02-01

Full Text Available Overactivity of the sympathetic nervous system and central endothelins (ETs are involved in the development of hypertension. Besides the well-known brain structures involved in the regulation of blood pressure like the hypothalamus or locus coeruleus, evidence suggests that the olfactory bulb (OB also modulates cardiovascular function. In the present study, we evaluated the interaction between the endothelinergic and catecholaminergic systems in the OB of deoxycorticosterone acetate (DOCA-salt hypertensive rats. Following brain ET receptor type A (ETA blockade by BQ610 (selective antagonist, transcriptional, traductional, and post-traductional changes in tyrosine hydroxylase (TH were assessed in the OB of normotensive and DOCA-salt hypertensive rats. Time course variations in systolic blood pressure and heart rate were also registered. Results showed that ETA blockade dose dependently reduced blood pressure in hypertensive rats, but it did not change heart rate. It also prevented the increase in TH activity and expression (mRNA and protein in the right OB of hypertensive animals. However, ETA blockade did not affect hemodynamics or TH in normotensive animals. Present results support that brain ETA are not involved in blood pressure regulation in normal rats, but they significantly contribute to chronic blood pressure elevation in hypertensive animals. Changes in TH activity and expression were observed in the right but not in the left OB, supporting functional asymmetry, in line with previous studies regarding cardiovascular regulation. Present findings provide further evidence on the role of ETs in the regulation of catecholaminergic activity and the contribution of the right OB to DOCA-salt hypertension.

Chronic Blockade of Brain Endothelin Receptor Type-A (ETA) Reduces Blood Pressure and Prevents Catecholaminergic Overactivity in the Right Olfactory Bulb of DOCA-Salt Hypertensive Rats.

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Cassinotti, Luis R; Guil, María J; Schöller, Mercedes I; Navarro, Mónica P; Bianciotti, Liliana G; Vatta, Marcelo S

2018-02-27

Overactivity of the sympathetic nervous system and central endothelins (ETs) are involved in the development of hypertension. Besides the well-known brain structures involved in the regulation of blood pressure like the hypothalamus or locus coeruleus, evidence suggests that the olfactory bulb (OB) also modulates cardiovascular function. In the present study, we evaluated the interaction between the endothelinergic and catecholaminergic systems in the OB of deoxycorticosterone acetate (DOCA)-salt hypertensive rats. Following brain ET receptor type A (ET A ) blockade by BQ610 (selective antagonist), transcriptional, traductional, and post-traductional changes in tyrosine hydroxylase (TH) were assessed in the OB of normotensive and DOCA-salt hypertensive rats. Time course variations in systolic blood pressure and heart rate were also registered. Results showed that ET A blockade dose dependently reduced blood pressure in hypertensive rats, but it did not change heart rate. It also prevented the increase in TH activity and expression (mRNA and protein) in the right OB of hypertensive animals. However, ET A blockade did not affect hemodynamics or TH in normotensive animals. Present results support that brain ET A are not involved in blood pressure regulation in normal rats, but they significantly contribute to chronic blood pressure elevation in hypertensive animals. Changes in TH activity and expression were observed in the right but not in the left OB, supporting functional asymmetry, in line with previous studies regarding cardiovascular regulation. Present findings provide further evidence on the role of ETs in the regulation of catecholaminergic activity and the contribution of the right OB to DOCA-salt hypertension.

Argirein alleviates stress-induced and diabetic hypogonadism in rats via normalizing testis endothelin receptor A and connexin 43.

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Xu, Ming; Hu, Chen; Khan, Hussein-hamed; Shi, Fang-hong; Cong, Xiao-dong; Li, Qing; Dai, Yin; Dai, De-zai

2016-02-01

Argirein (rhein-arginine) is a derivative of rhein isolated from Chinese rhubarb (Rheum Officinale Baill.) that exhibits antioxidant and anti-inflammatory activities. In the present study we investigated the effects of argirein on stress-induced (hypergonadotrophic) and diabetic (hypogonadotrophic) hypogonadism in male rats. Stress-induced and diabetic hypogonadism was induced in male rats via injection of isoproterenol (ISO) or streptozotocin (STZ). ISO-injected rats were treated with argirein (30 mg·kg(-1)·d(-1), po) or testosterone replacement (0.5 mg·kg(-1)·d(-1), sc) for 5 days, and STZ-injected rats were treated with argirein (40-120 mg·kg(-1)·d(-1), po) or aminoguanidine (100 mg·kg(-1)·d(-1), po) for 4 weeks. After the rats were euthanized, blood samples and testes were collected. Serum hormone levels were measured, and the expression of endothelin receptor A (ETA), connexin 43 (Cx43) and other proteins in testes was detected. For in vitro experiments, testis homogenate was prepared from normal male rats, and incubated with ISO (1 μmol/L) or high glucose (27 mmol/L). ISO injection induced hyper-gonadotrophic hypogonadism characterized by low testosterone and high FSH and LH levels in the serum, whereas STZ injection induced hypogonadotrophic hypogonadism as evidenced by low testosterone and low FSH and LH levels in the serum. In the testes of ISO- and STZ-injected rats, the expression of ETA, MMP-9, NADPH oxidase and pPKCε was significantly increased, and the expression of Cx43 was decreased. Administration of argirein attenuated both the abnormal serum hormone levels and the testis changes in ISO- and STZ-injected rats, and aminoguanidine produced similar actions in STZ-injected rats; testosterone replacement reversed the abnormal serum hormone levels, but did not affect the testis changes in ISO-injected rats. Argirein (0.3-3 μmol/L) exerted similar effects in testis homogenate incubated with ISO or high glucose in vitro. Two types of

Effects of angiotensin II type 1 receptor blocker on bones in mice with type 1 diabetes induced by streptozotocin.

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Zhang, Yan; Diao, Teng-Yue; Gu, Sa-Sa; Wu, Shu-Yan; Gebru, Yoseph A; Chen, Xi; Wang, Jing-Yu; Ran, Shu; Wong, Man-Sau

2014-09-01

This study was performed to address the pathological roles of the skeletal renin-angiotensin system (RAS) in type 1 diabetes-induced osteoporosis and the effects of the angiotensin II type 1 receptor blocker losartan on bones in diabetic mice. Bone histomorphology was detected by H&E staining, Safranin O staining and X-ray radiography. Micro-CT was performed for the analysis of bone parameters. Gene and protein expression were determined by RT-PCR and immunoblotting. Type 1 diabetic mice displayed osteopenia phenotype, and losartan treatment had no osteoprotective effects on diabetic mice as shown by the reduction of bone mineral density and microarchitectural parameters at the proximal metaphysis of the tibia. The mRNA expression of AGT, renin receptor and ACE, and protein expression of renin and AT1R were markedly up-regulated in the bones of vehicle-treated diabetic mice compared to those of non-diabetic mice. The treatment with losartan further significantly increased the expression of AGT, renin, angiotensin II and AT1R, and reduced the expression of AT2R receptor as compared to those of diabetic mice. Local bone RAS functionally played a role in the development of type 1 diabetic osteoporosis, and losartan had no bone-sparing function in diabetes mice because of enhance skeletal RAS activity. © The Author(s) 2013.

A sensitive radioimmunoassay measuring endothelin-like immunoreactivity in human plasma: comparison of levels in patients with essential hypertension and normotensive control subjects

International Nuclear Information System (INIS)

Davenport, A.P.; Ashby, M.J.; Easton, Patricia

1990-01-01

A radioimmunoassay was developed to measure endothelin-like immunoreactivity in human plasma using antibody raised against endothelin-1 which also cross-reacts with big endothelin-1 and endothelin-2 but not endothelin-3. The sensitivity was 1 fmol/tube with inter- and intra-assay coefficients of variation of 13% and 9%, respectively. Cross-reactivity with endothelin-3 and non-endothelin peptides was less than 1%. Endothelin-like immunoreactivity was present in plasma of hypertensive patients (n = 25) at 5.7±0.5 pmol/1 (mean±SEM), not significantly different from that of age-matched control subjects (5.1±0.5 pmol/1). At these levels, endothelin-1 is unlikely to function as a circulating hormone. In the normotensive group, the concentration of endothelin-like immunoreactivity in plasma was positively correlated with mean arterial blood pressure, but in hypertensive patients it showed significant negative correlation. (author)

Endothelin-1 Regulation of Exercise-Induced Changes in Flow: Dynamic Regulation of Vascular Tone

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Robert M. Rapoport

2017-10-01

Full Text Available Although endothelin (ET-1 is a highly potent vasoconstrictor with considerable efficacy in numerous vascular beds, the role of endogenous ET-1 in the regulation of vascular tone remains unclear. The perspective that ET-1 plays little role in the on-going regulation of vascular tone at least under physiologic conditions is supported by findings that potential ET-1 constriction is minimized by the release of the vasodilator and ET-1 synthesis inhibitor, nitric oxide (NO. Indeed, ET-1 release and constriction is self-limited by ET-1-induced, endothelial ETB receptor-mediated release of NO. Moreover, even if the balance between ET-1 and NO were reversed as the result of lowered NO activity, as occurs in a number of pathophysiologies associated with endothelial dysfunction, the well-known resistance of ET-1 constriction to reversal (as determined with exogenous ET-1 precludes ET-1 in the dynamic, i.e., moment-to-moment, regulation of vascular tone. On the other hand, and as presently reviewed, findings of ET-1-dependent modulation of organ blood flow with exercise under physiologic conditions demonstrate the dynamic regulation of vascular tone by ET-1. We speculate that this regulation is mediated at least in part through changes in ET-1 synthesis/release caused by pulsatile flow-induced shear stress and NO.

Randomized controlled trial using bosentan to enhance the impact of exercise training in subjects with type 2 diabetes mellitus.

NARCIS (Netherlands)

Schreuder, T.H.A.; Duncker, D.J.; Hopman, M.T.E.; Thijssen, D.H.J.

2014-01-01

In type 2 diabetes patients, endothelin (ET) receptor blockade may enhance blood flow responses to exercise training. The combination of exercise training and ET receptor blockade may represent a more potent stimulus than training alone to improve vascular function, physical fitness and glucose

The mechanisms behind decreased internalization of angiotensin II type 1 receptor.

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Bian, Jingwei; Zhang, Suli; Yi, Ming; Yue, Mingming; Liu, Huirong

2018-04-01

The internalization of angiotensin II type 1 receptor (AT 1 R) plays an important role in maintaining cardiovascular homeostasis. Decreased receptor internalization is closely related to cardiovascular diseases induced by the abnormal activation of AT 1 R, such as hypertension. However, the mechanism behind reduced AT 1 R internalization is not fully understood. This review focuses on four parts of the receptor internalization process (the combination of agonists and receptors, receptor phosphorylation, endocytosis, and recycling) and summarizes the possible mechanisms by which AT 1 R internalization is reduced based on these four parts of the process. (1) The agonist has a large molecular weight or a stronger ability to hydrolyze phosphatidylinositol 4,5-bisphosphate (PtdIns (4,5) P 2 ), which can increase the consumption of PtdIns (4,5) P 2 . (2) AT 1 R phosphorylation is weakened because of an abnormal function of phosphorylated kinase or changes in phospho-barcoding and GPCR-β-arrestin complex conformation. (3) The abnormal formation of vesicles or AT 1 R heterodimers with fewer endocytic receptors results in less AT 1 R endocytosis. (4) The enhanced activity and upregulated expression of small GTP-binding protein 4 (Rab4) and 11 (Rab11), which regulate receptor recycling, and phosphatidylinositol 3-kinase increase AT 1 R recycling. In addition, lower expression of AT 1 R-associated protein (ATRAP) or higher expression of AT 1 R-associated protein 1 (ARAP1) can reduce receptor internalization. Copyright © 2018 Elsevier Inc. All rights reserved.

Enhanced expressions of microvascular smooth muscle receptors after focal cerebral ischemia occur via the MAPK MEK/ERK pathway

DEFF Research Database (Denmark)

Maddahi, A.; Edvinsson, L.

2008-01-01

), the enhanced vascular receptor expression, and attenuated the cerebral infarct and improved neurology score. CONCLUSION: Our results show that MCAO results in upregulation of cerebrovascular ETB, AT1 and 5-HT1B receptors. Blockade of this event with a MEK1 inhibitor as late as 6 h after the insult reduced...... the role of the MEK/ERK pathway in receptor expression following ischemic brain injury using the specific MEK1 inhibitor U0126. METHODS AND RESULT: Rats were subjected to a 2-h middle cerebral artery occlusion (MCAO) followed by reperfusion for 48-h and the ischemic area was calculated. The expression...... of phosphorylated ERK1/2 and Elk-1, and of endothelin ETA and ETB, angiotensin AT1, and 5-hydroxytryptamine 5-HT1B receptors were analyzed with immunohistochemistry using confocal microscopy in cerebral arteries, microvessels and in brain tissue. The expression of endothelin ETB receptor was analyzed...

Endothelin-1 in systemic sclerosis

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C. Pizzorni

2011-09-01

Full Text Available We evaluated endothelin-1 (ET-1 plasma levels in patients affected by primary Raynaud’s phenomenon (PRP, as well as in patients with systemic sclerosis (SSc and secondary Raynaud’s phenomenon (SRP. Furthermore, ET-1 levels were investigated in SSc patients with different patterns of peripheral microvascular damage, as evaluated by nailfold videocapillaroscopy (NVC. Methods: 23 PRP patients, 67 SSc patients according to ACR criteria, and 23 healthy subjects were enrolled. SSc microvascular involvement was classified in three different patterns (Early, Active, and Late by NVC, as previously described. Results: ET-1 was found significantly higher in both PRP and SRP, when compared with controls (median ±IQR: 3.3±2.8, 2.7±2.2, 2.0±2.2, respectively (p=0.05. No statistically significant difference of ET-1 levels was observed between PRP and SRP patients. ET-1 was found higher in patients with Late NVC pattern, when compared with both Active and Early NVC patterns (median±IQR: 3.4±2.5, 2.4±2.2, 2.5±2.1, respectively, but without statistical significance. Patients with Late NVC pattern showed significantly higher ET-1 plasma levels than controls (p=0.03. No correlation was found between ET-1 levels and disease duration in both groups, as well as between ET-1 levels and age of patients. Conclusions: These data support previous studies, reporting increased ET-1 plasma levels in both PRP and SRP patients. Interestingly, patients with the Late NVC pattern of microangiopathy showed higher ET-1 plasma levels than controls. The high levels of ET-1 detected in the Late NVC pattern of microangiopathy might be related to the larger fibrotic involvement typical of the advanced stages of disease.

Anti-hypotensive treatment and endothelin blockade synergistically antagonize exercise fatigue in rats under simulated high altitude.

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Daniel Radiloff

Full Text Available Rapid ascent to high altitude causes illness and fatigue, and there is a demand for effective acute treatments to alleviate such effects. We hypothesized that increased oxygen delivery to the tissue using a combination of a hypertensive agent and an endothelin receptor A antagonist drugs would limit exercise-induced fatigue at simulated high altitude. Our data showed that the combination of 0.1 mg/kg ambrisentan with either 20 mg/kg ephedrine or 10 mg/kg methylphenidate significantly improved exercise duration in rats at simulated altitude of 4,267 m, whereas the individual compounds did not. In normoxic, anesthetized rats, ephedrine alone and in combination with ambrisentan increased heart rate, peripheral blood flow, carotid and pulmonary arterial pressures, breathing rate, and vastus lateralis muscle oxygenation, but under inspired hypoxia, only the combination treatment significantly enhanced muscle oxygenation. Our results suggest that sympathomimetic agents combined with endothelin-A receptor blockers offset altitude-induced fatigue in rats by synergistically increasing the delivery rate of oxygen to hypoxic muscle by concomitantly augmenting perfusion pressure and improving capillary conductance in the skeletal muscle. Our findings might therefore serve as a basis to develop an effective treatment to prevent high-altitude illness and fatigue in humans.

Role of endothelin receptor activation in secondary pulmonary hypertension in awake swine after myocardial infarction

NARCIS (Netherlands)

B. Houweling (Birgit); D. Merkus (Daphne); O. Sorop (Oana); F. Boomsma (Frans); D.J.G.M. Duncker (Dirk)

2006-01-01

textabstractWe previously observed that pulmonary hypertension secondary to myocardial infarction (MI) in swine is characterized by elevated plasma endothelin (ET) levels and pulmonary vascular resistance (PVR). Consequently, we tested the hypothesis that an increased ET-mediated vasoconstrictor

Reduced post-synaptic serotonin type 1A receptor binding in bipolar depression

Science.gov (United States)

Nugent, Allison C.; Bain, Earle E.; Carlson, Paul J.; Neumeister, Alexander; Bonne, Omer; Carson, Richard E.; Eckelman, William; Herscovitch, Peter; Zarate, Carlos A.; Charney, Dennis S.; Drevets, Wayne C.

2013-01-01

Multiple lines of evidence suggest that serotonin type 1A (5-HT1A) receptor dysfunction is involved in the pathophysiology of mood disorders, and that alterations in 5-HT1A receptor function play a role in the mechanisms of antidepressant and mood stabilizer treatment. The literature is in disagreement, however, as to whether 5-HT1A receptor binding abnormalities exist in bipolar disorder (BD). We acquired PET images of 5-HT1A receptor binding in 26 unmedicated BD subjects and 37 healthy controls using [18F]FCWAY, a highly selective 5-HT1A receptor radio-ligand. The mean 5-HT1A receptor binding potential (BPP) was significantly lower in BD subjects compared to controls in cortical regions where 5-HT1A receptors are expressed post-synaptically, most prominently in the mesiotemporal cortex. Post-hoc assessments involving other receptor specific binding parameters suggested that this difference particularly affected the females with BD. The mean BPP did not differ between groups in the raphe nucleus, however, where 5-HT1A receptors are predominantly expressed pre-synaptically. Across subjects the BPP in the mesiotemporal cortex was inversely correlated with trough plasma cortisol levels, consistent with preclinical literature indicating that hippocampal 5-HT1A receptor expression is inhibited by glucocorticoid receptor stimulation. These findings suggest that 5-HT1A receptor binding is abnormally reduced in BD, and this abnormality may particularly involve the postsynaptic 5-HT1A receptor system of individuals with a tendency toward cortisol hypersecretion. PMID:23434290

Multiple sleep alterations in mice lacking cannabinoid type 1 receptors.

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Alessandro Silvani

Full Text Available Cannabinoid type 1 (CB1 receptors are highly expressed in the brain and play a role in behavior control. Endogenous cannabinoid signaling is modulated by high-fat diet (HFD. We investigated the consequences of congenital lack of CB1 receptors on sleep in mice fed standard diet (SD and HFD. CB1 cannabinoid receptor knock-out (KO and wild-type (WT mice were fed SD or HFD for 4 months (n = 9-10 per group. Mice were instrumented with electroencephalographic (EEG and electromyographic electrodes. Recordings were performed during baseline (48 hours, sleep deprivation (gentle handling, 6 hours, sleep recovery (18 hours, and after cage switch (insomnia model paradigm, 6 hours. We found multiple significant effects of genotype on sleep. In particular, KO spent more time awake and less time in non-rapid-eye-movement sleep (NREMS and rapid-eye-movement sleep (REMS than WT during the dark (active period but not during the light (rest period, enhancing the day-night variation of wake-sleep amounts. KO had slower EEG theta rhythm during REMS. REMS homeostasis after sleep deprivation was less effective in KO than in WT. Finally, KO habituated more rapidly to the arousing effect of the cage-switch test than WT. We did not find any significant effects of diet or of diet x genotype interaction on sleep. The occurrence of multiple sleep alterations in KO indicates important roles of CB1 cannabinoid receptors in limiting arousal during the active period of the day, in sleep regulation, and in sleep EEG in mice.

Effects of bosentan on collagen type I synthesis on in vitro culture of scleroderma skin fibroblasts

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S. Soldano

2011-01-01

Full Text Available The present study evaluated the effects of a non-selective endothelin (ETA/B receptors antagonist, on collagen type I (COLI synthesis on in vitro culture of scleroderma (SSc skin fibroblasts (Fb. Fb were obtained from skin biopsies of 6 female SSc patients (mean age 64. 1±6 years, after informed consent and Ethical Committee Approval. Cells were treated with endothelin-I [ET-I, 100nM] for 24 and 48 hrs, pre-treated for I hr with ETA/B receptors antagonist [10nM] alone or followed by ET-I for 24 and 48 hrs. Untreated Fb were used as controls. Immunocytochemistry and western blot analysis were performed to evaluate COLI synthesis. ET-I increased COLI synthesis both at 24 and 48 hrs when compared to controls. ETA/B receptor antagonost blocks the increased COLI synthesis ET-I-mediated both at 24 and 48 hrs vs. ET-I. Results showed that ET-I receptors blockage by ETA/B receptors antagonist might prevent the excessive synthesis of COLI, supporting its positive action in the management of skin fibrosis.

Endothelin-1 mediates natriuresis but not polyuria during vitamin D-induced acute hypercalcaemia.

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Tokonami, Natsuko; Cheval, Lydie; Monnay, Isabelle; Meurice, Guillaume; Loffing, Johannes; Feraille, Eric; Houillier, Pascal

2017-04-15

Hypercalcaemia can occur under various pathological conditions, such as primary hyperparathyroidism, malignancy or granulomatosis, and it induces natriuresis and polyuria in various species via an unknown mechanism. A previous study demonstrated that hypercalcaemia induced by vitamin D in rats increased endothelin (ET)-1 expression in the distal nephron, which suggests the involvement of the ET system in hypercalcaemia-induced effects. In the present study, we demonstrate that, during vitamin D-induced hypercalcaemia, the activation of ET system by increased ET-1 is responsible for natriuresis but not for polyuria. Vitamin D-treated hypercalcaemic mice showed a blunted response to amiloride, suggesting that epithelial sodium channel function is inhibited. We have identified an original pathway that specifically mediates the effects of vitamin D-induced hypercalcaemia on sodium handling in the distal nephron without affecting water handling. Acute hypercalcaemia increases urinary sodium and water excretion; however, the underlying molecular mechanism remains unclear. Because vitamin D-induced hypercalcaemia increases the renal expression of endothelin (ET)-1, we hypothesized that ET-1 mediates the effects of hypercalcaemia on renal sodium and water handling. Hypercalcaemia was induced in 8-week-old, parathyroid hormone-supplemented, male mice by oral administration of dihydrotachysterol (DHT) for 3 days. DHT-treated mice became hypercalcaemic and displayed increased urinary water and sodium excretion compared to controls. mRNA levels of ET-1 and the transcription factors CCAAT-enhancer binding protein β and δ were specifically increased in the distal convoluted tubule and downstream segments in DHT-treated mice. To examine the role of the ET system in hypercalcaemia-induced natriuresis and polyuria, mice were treated with the ET-1 receptor antagonist macitentan, with or without DHT. Mice treated with both macitentan and DHT displayed hypercalcaemia and polyuria

Increased transient receptor potential vanilloid type 1 (TRPV1) channel expression in hypertrophic heart

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Thilo, Florian; Liu, Ying; Schulz, Nico

2010-01-01

The aim of this study was to compare the expression of transient receptor potential vanilloid type 1 (TRPV1) channels in hypertrophic hearts from transgenic mice showing overexpression of the catalytic subunit alpha of protein phosphatase 2A alpha (PP2Ac alpha) with wild-type mice and with TRPV1-...... alpha transgenic mice compared to wild-type mice and TRPV1-/- mice (8.6±1.3mg/g; 5.4±0.3mg/g; and 5.4±0.4mg/g; respectively; p...

Design of ET(B) receptor agonists: NMR spectroscopic and conformational studies of ET7-21[Leu7, Aib11, Cys(Acm)15].

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Hewage, Chandralal M; Jiang, Lu; Parkinson, John A; Ramage, Robert; Sadler, Ian H

2002-03-01

In a previous report we have shown that the endothelin-B receptor-selective linear endothelin peptide, ET-1[Cys (Acm)1,15, Ala3, Leu7, Aib11], folds into an alpha-helical conformation in a methanol-d3/water co-solvent [Hewage et al. (1998) FEBS Lett., 425, 234-238]. To study the requirements for the structure-activity relationships, truncated analogues of this peptide were subjected to further studies. Here we report the solution conformation of ET7-21[Leu7, Aib11, Cys(Acm)15], in a methanol-d3/water co-solvent at pH 3.6, by NMR spectroscopic and molecular modelling studies. Further truncation of this short peptide results in it displaying poor agonist activity. The modelled structure shows that the peptide folds into an alpha-helical conformation between residues Lys9-His16, whereas the C-terminus prefers no fixed conformation. This truncated linear endothelin analogue is pivotal for designing endothelin-B receptor agonists.

Co-inhibition of Angiotensin II Receptor and Endothelin-1 Attenuates Renal Injury in Unilateral Ureteral Obstructed Mice

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Yoon-Kyung Chang

2016-07-01

Full Text Available Background/Aims: Both endothelin-1 (ET-1 and the renin-angiotensin system (RAS may play important roles in renal fibrosis in the obstructed kidney. However, there have been few clear demonstrations of a relationship between their activation and additive or synergistic roles in renal fibrosis. We investigated the protective roles and relationship between renal RAS and ET-1 in unilateral ureteral obstruction (UUO mice. Methods: 8-week-old male C57BL/6 mice were divided into seven groups: sham, bosentan+sham, valsartan+sham, vehicle+UUO, bosentan+UUO, valsartan+UUO, and valsartan+bosentan+UUO. Valsartan and bosentan were administered orally using an NG tube (valsartan 10 mg/kg/day, bosentan 100 mg/kg/day for 8 days, after which the molecular and structural kidney parameters were evaluated. Bosentan treatment elevated plasma renin activity, renal renin, and AT1R expression in UUO mice. Results: Although valsartan decreased plasma ET-1 in these mice, it did not affect ET(A or ET(B in their kidneys. Co-treatment with valsartan and bosentan decreased ET-1 in these mice compared to the single treatments. Bosentan, but not valsartan, elevated eNOS expression in their kidneys. Co-treatment with valsartan and bosentan reduced TGF-β, α-SMA, and collagen IV expression, and the Masson's trichrome stained area in their kidneys. Conclusions: Bosentan and valsartan acted complementarily, and co-treatment with both drugs had an additive protective effect against renal fibrosis.

Greater Sensitivity of Blood Pressure Than Renal Toxicity to Tyrosine Kinase Receptor Inhibition With Sunitinib

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Lankhorst, Stephanie; Baelde, Hans J; Kappers, Mariëtte H W

2015-01-01

Hypertension and renal injury are off-target effects of sunitinib, a tyrosine kinase receptor inhibitor used for the treatment of various tumor types. Importantly, these untoward effects are accompanied by activation of the endothelin system. Here, we set up a study to explore the dose dependency...

The observation on plasma endothelin levels in patients with graves' disease

International Nuclear Information System (INIS)

Hao Xiaojun; Liu Changshan; Yang Lianrong; Zhang Qiliang; Wang Honggang; Liu Xudong

2002-01-01

Observing the plasma endothelin levels in patients with Graves' disease to probe its clinical significance, plasma endothelin levels were measured in 55 cases of Graves' disease before and after treatment respectively, and these were compared with that of 23 health subjects. Results: plasma endothelin levels in patients with Graves' disease significantly increase, compared with heath subjects (150.4 +- 29.31 ng/L vs 42.80 +- 7.58 ng/L, P < 0.01); post-treatment endothelin levels apparently decrease (97.61 +- 15.99 ng/L vs 150.4 +- 29.31 ng/L, P < 0.01). Plasma endothelin levels in patients with Graves' disease significantly increase, and after treatment the endothelin levels decrease following decreasing of thyroid hormone level and high hemodynamics

Accessibility of receptor-bound urokinase to type-1 plasminogen activator inhibitor

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Cubellis, M.V.; Andreasen, P.; Ragno, P.; Mayer, M.; Dano, K.; Blasi, F. (Univ. of Copenhagen (Denmark))

1989-07-01

Urokinase plasminogen activator (uPA) interacts with a surface receptor and with specific inhibitors, such as plasminogen activator inhibitor type 1 (PAI-1). These interactions are mediated by two functionally independent domains of the molecule: the catalytic domain (at the carboxyl terminus) and the growth factor domain (at the amino terminus). The authors have now investigated whether PAI-1 can bind and inhibit receptor-bound uPA. Binding of {sup 125}I-labeled ATF (amino-terminal fragment of uPA) to human U937 monocyte-like cells can be competed for by uPA-PAI-1 complexes, but not by PAI-1 alone. Preformed {sup 125}I-labeled uPA-PAI-1 complexes can bind to uPA receptor with the same binding specificity as uPA. PAI-1 also binds to, and inhibits the activity of, receptor-bound uPA in U937 cells, as shown in U937 cells by a caseinolytic plaque assay. Plasminogen activator activity of these cells is dependent on exogenous uPA, is competed for by receptor-binding diisopropyl fluorophosphate-treated uPA, and is inhibited by the addition of PAI-1. In conclusion, in U937 cells the binding to the receptor does not shield uPA from the action of PAI-1. The possibility that in adherent cells a different localization of PAI-1 and uPA leads to protection of uPA from PAI-1 is to be considered.

The Role of Endothelin System in Renal Structure and Function during the Postnatal Development of the Rat Kidney.

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Albertoni Borghese, María F; Ortiz, María C; Balonga, Sabrina; Moreira Szokalo, Rocío; Majowicz, Mónica P

2016-01-01

Renal development in rodents, unlike in humans, continues during early postnatal period. We aimed to evaluate whether the pharmacological inhibition of Endothelin system during this period affects renal development, both at structural and functional level in male and female rats. Newborn rats were treated orally from postnatal day 1 to 20 with vehicle or bosentan (Actelion, 20 mg/kg/day), a dual endothelin receptor antagonist (ERA). The animals were divided in 4 groups: control males, control females, ERA males and ERA females. At day 21, we evaluated renal function, determined the glomerular number by a maceration method and by morphometric analysis and evaluated possible structural renal alterations by three methods: 〈alpha〉-Smooth muscle actin (α-SMA) immunohistochemistry, Masson's trichrome and Sirius red staining. The pharmacological inhibition of Endothelin system with a dual ERA during the early postnatal period of the rat did not leads to renal damage in the kidneys of male and female rats. However, ERA administration decreased the number of glomeruli, the juxtamedullary filtration surface area and the glomerular filtration rate and increased the proteinuria. These effects could predispose to hypertension or renal diseases in the adulthood. On the other hand, these effects were more pronounced in male rats, suggesting that there are sex differences that could be greater later in life. These results provide evidence that Endothelin has an important role in rat renal postnatal development. However these results do not imply that the same could happen in humans, since human renal development is complete at birth.

Prognostic value of plasma midregional pro-adrenomedullin and C-terminal-pro-endothelin-1 in chronic heart failure outpatients.

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Adlbrecht, Christopher; Hülsmann, Martin; Strunk, Guido; Berger, Rudolf; Mörtl, Deddo; Struck, Joachim; Morgenthaler, Nils G; Bergmann, Andreas; Jakowitsch, Johannes; Maurer, Gerald; Lang, Irene M; Pacher, Richard

2009-04-01

The identification of chronic heart failure (CHF) patients at high risk of adverse outcome remains a challenge. New peptides are emerging that may give additional information. In CHF patients, endothelin (ET) levels predict mortality risk. Adrenomedullin has been shown to predict mortality in ischaemic heart failure, but not in unselected or non-ischaemic CHF patients. Moreover, ADM and ET have never been assessed in one model. The aim of the present study was to assess the prognostic value of midregional-pro-adrenomedullin (MR-proADM) and C-terminal-pro-endothelin-1 (CT-proET-1) in outpatients with CHF. We measured plasma MR-proADM and CT-proET-1 levels in 786 consecutive CHF outpatients and compared them with B-type natriuretic peptide (BNP) levels. At 24-month follow-up, 233 patients had died. A stepwise forward Cox regression model with age, sex, estimated glomerular filtration rate, NYHA > II, left ventricular ejection fraction (LVEF), MR-proADM, CT-proET-1, and BNP as possible predictors revealed that MR-proADM levels [hazard ratio (HR) = 1.77, P II (HR = 1.86, P < 0.001) were predictors of death at 24 months. When the analysis was repeated dependent on NYHA-stage, MR-proADM (HR = 2.12, P < 0.001) and LVEF (HR = 0.96, P = 0.006) were significant markers, but only in patients with mild/moderate CHF. Our data suggest that MR-proADM may be an important prognostic humoral marker, especially in mild/moderately symptomatic and non-ischaemic CHF patients.

Effect of endothelin-1 on the excitability of rat cortical and hippocampal slices in vitro

Czech Academy of Sciences Publication Activity Database

Konopková, Renata; Világi, I.; Borbély, S.; Kubová, Hana; Otáhal, Jakub

2012-01-01

Roč. 61, č. 2 (2012), s. 215-219 ISSN 0862-8408 R&D Projects: GA MŠk(CZ) LC554; GA AV ČR(CZ) 1QS501210509; GA ČR(CZ) GD305/08/H037 Institutional research plan: CEZ:AV0Z50110509 Keywords : Endothelin-1 * excitability * hippocampus * somatosensory cortex * rat * epileptogenesis Subject RIV: FH - Neurology Impact factor: 1.531, year: 2012

Computer modeling of Cannabinoid receptor type 1

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Sapundzhi Fatima

2018-01-01

Full Text Available Cannabinoid receptors are important class of receptors as they are involved in various physiological processes such as appetite, pain-sensation, mood, and memory. It is important to design receptor-selective ligands in order to treat a particular disorder. The aim of the present study is to model the structure of cannabinoid receptor CB1 and to perform docking between obtained models and known ligands. Two models of CBR1 were prepared with two different methods (Modeller of Chimera and MOE. They were used for docking with GOLD 5.2. It was established a high correlation between inhibitory constant Ki of CB1 cannabinoid ligands and the ChemScore scoring function of GOLD, which concerns both models. This suggests that the models of the CB1 receptors obtained could be used for docking studies and in further investigation and design of new potential, selective and active cannabinoids with the desired effects.

Relationships between endothelin and insulin receptor of red blood cell and insulin resistance in patients with hypertension

International Nuclear Information System (INIS)

Tong Qian; Zheng Yang; Xu Hui

2004-01-01

Objective: To find the relationships between endothelin (ET) and insulin resistance (IR) and insulin receptor (INSR) in patients with essential hypertension. Methods: Forty patients including 20 cases of essential hypertension disease (EHD) and 20 health persons were divided into experimental group and control group. Blood glucose, serum insulin, ET and the number of erythrocyte INSR in all patients during fasting condition were detected by radioimmunoassay and radiometric analysis. Results: Both insulin sensitivity index (ISI) and the number of INSR in EHD group were much less than that of control group, on the contrary, ET level of EHD group was significantly higher than that of control group (P<0.05). Statistical analysis demonstrated a negative correlation between ET and ISI and INSR number existed in EHD group. Conclusion: IR is a common phenomenon in patient with EHD and possibly due to decrease of INSR number. The ET levels are higher in patients with EHD than that in health people and correlate with INSR, and the change of INSR number is the possible mediator for their relationship

Amelioration of cold injury-induced cortical brain edema formation by selective endothelin ETB receptor antagonists in mice.

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Michinaga, Shotaro; Nagase, Marina; Matsuyama, Emi; Yamanaka, Daisuke; Seno, Naoki; Fuka, Mayu; Yamamoto, Yui; Koyama, Yutaka

2014-01-01

Brain edema is a potentially fatal pathological condition that often occurs in stroke and head trauma. Following brain insults, endothelins (ETs) are increased and promote several pathophysiological responses. This study examined the effects of ETB antagonists on brain edema formation and disruption of the blood-brain barrier in a mouse cold injury model (Five- to six-week-old male ddY mice). Cold injury increased the water content of the injured cerebrum, and promoted extravasation of both Evans blue and endogenous albumin. In the injury area, expression of prepro-ET-1 mRNA and ET-1 peptide increased. Intracerebroventricular (ICV) administration of BQ788 (ETB antagonist), IRL-2500 (ETB antagonist), or FR139317 (ETA antagonist) prior to cold injury significantly attenuated the increase in brain water content. Bolus administration of BQ788, IRL-2500, or FR139317 also inhibited the cold injury-induced extravasation of Evans blue and albumin. Repeated administration of BQ788 and IRL-2500 beginning at 24 h after cold injury attenuated both the increase in brain water content and extravasation of markers. In contrast, FR139317 had no effect on edema formation when administrated after cold injury. Cold injury stimulated induction of glial fibrillary acidic protein-positive reactive astrocytes in the injured cerebrum. Induction of reactive astrocytes after cold injury was attenuated by ICV administration of BQ788 or IRL-2500. These results suggest that ETB receptor antagonists may be an effective approach to ameliorate brain edema formation following brain insults.

The angiotensin II type 1 receptor antagonist Losartan binds and activates bradykinin B2 receptor signaling

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Bonde, Marie Mi; Olsen, Kristine Boisen; Erikstrup, Niels

2011-01-01

The angiotensin II type 1 receptor (AT1R) blocker (ARB) Losartan has cardioprotective effects during ischemia-reperfusion injury and inhibits reperfusion arrhythmias -effects that go beyond the benefits of lowering blood pressure. The renin-angiotensin and kallikrein-kinin systems are intricately...

Striatal D1- and D2-type dopamine receptors are linked to motor response inhibition in human subjects.

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Robertson, Chelsea L; Ishibashi, Kenji; Mandelkern, Mark A; Brown, Amira K; Ghahremani, Dara G; Sabb, Fred; Bilder, Robert; Cannon, Tyrone; Borg, Jacqueline; London, Edythe D

2015-04-15

Motor response inhibition is mediated by neural circuits involving dopaminergic transmission; however, the relative contributions of dopaminergic signaling via D1- and D2-type receptors are unclear. Although evidence supports dissociable contributions of D1- and D2-type receptors to response inhibition in rats and associations of D2-type receptors to response inhibition in humans, the relationship between D1-type receptors and response inhibition has not been evaluated in humans. Here, we tested whether individual differences in striatal D1- and D2-type receptors are related to response inhibition in human subjects, possibly in opposing ways. Thirty-one volunteers participated. Response inhibition was indexed by stop-signal reaction time on the stop-signal task and commission errors on the continuous performance task, and tested for association with striatal D1- and D2-type receptor availability [binding potential referred to nondisplaceable uptake (BPND)], measured using positron emission tomography with [(11)C]NNC-112 and [(18)F]fallypride, respectively. Stop-signal reaction time was negatively correlated with D1- and D2-type BPND in whole striatum, with significant relationships involving the dorsal striatum, but not the ventral striatum, and no significant correlations involving the continuous performance task. The results indicate that dopamine D1- and D2-type receptors are associated with response inhibition, and identify the dorsal striatum as an important locus of dopaminergic control in stopping. Moreover, the similar contribution of both receptor subtypes suggests the importance of a relative balance between phasic and tonic dopaminergic activity subserved by D1- and D2-type receptors, respectively, in support of response inhibition. The results also suggest that the stop-signal task and the continuous performance task use different neurochemical mechanisms subserving motor response inhibition. Copyright © 2015 the authors 0270-6474/15/355990-08$15.00/0.

Protein kinase C inhibition prevents upregulation of vascular ET(B) and 5-HT(1B) receptors and reverses cerebral blood flow reduction after subarachnoid haemorrhage in rats

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Beg, Saema S; Hansen-Schwartz, Jacob A; Vikman, Petter J

2007-01-01

with Western blot; only PKCdelta and PKCalpha subtypes were increased after SAH RO-31-7549 treatment abolished this. At 2 days after the SAH basilar and middle cerebral arteries were harvested and the contractile response to endothelin-1 (ET-1; ET(A) and ET(B) receptor agonist) and 5-carboxamidotryptamine (5......-CT; 5-HT(1) receptor agonist) were investigated with a myograph. The contractile responses to ET-1 and 5-CT were increased (Poperated rats. In parallel, the ET(B) and 5-HT(1B) receptor mRNA and protein expression were significantly elevated after SAH, as analysed...

The Angiotensin II Type 1 Receptor Antagonist Losartan Affects NHE1-Dependent Melanoma Cell Behavior

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Daniel Navin Olschewski

2018-03-01

Full Text Available Background/Aims: The peptide hormone angiotensin II (ATII plays a prominent role in regulating vasoconstriction and blood pressure. Its primary target is the angiotensin II receptor type 1 (AT1, the stimulation of which induces an increase in cytosolic [Ca2+] and calmodulin activation. Ca2+-bound (activated calmodulin stimulates the activity of the Na+/ H+ exchanger isoform 1 (NHE1; and increased NHE1 activity is known to promote melanoma cell motility. The competitive AT1 receptor inhibitor losartan is often used to lower blood pressure in hypertensive patients. Since AT1 mediates ATII-stimulated NHE1 activity, we set out to investigate whether ATII and losartan have an impact on NHE1-dependent behavior of human melanoma (MV3 cells. Methods: ATII receptor expression was verified by PCR, F-actin was visualized using fluorescently labeled phalloidin, and cytosolic [Ca2+] and pH were determined ratiometrically using Fura-2 and BCECF, respectively. MV3 cell behavior was analyzed using migration, adhesion, invasion and proliferation assays. Results: MV3 cells express both AT1 and the angiotensin II receptor type 2 (AT2. Stimulation of MV3 cells with ATII increased NHE1 activity which could be counteracted by both losartan and the Ca2+/ calmodulin inhibitor ophiobolin-A. ATII stimulation induced a decrease in MV3 cell migration and a more spherical cell morphology accompanied by an increase in the density of F-actin. Independently of the presence of ATII, both NHE1 and migratory activity were reduced when AT1 was blocked by losartan. On the other hand, losartan clearly increased cell adhesion to, and the invasion of, a collagen type I substrate. The AT2 inhibitor PD123319 did not affect NHE1 activity, proliferation and migration, but increased adhesion and invasion. Conclusion: Losartan inhibits NHE1 activity and the migration of human melanoma cells. At the same time, losartan promotes MV3 cell adhesion and invasion. The therapeutic use of AT1

In vivo experimental stroke and in vitro organ culture induce similar changes in vasoconstrictor receptors and intracellular calcium handling in rat cerebral arteries

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Povlsen, Gro Klitgaard; Waldsee, Roya; Ahnstedt, Hilda

2012-01-01

Cerebral arteries subjected to different types of experimental stroke upregulate their expression of certain G-protein-coupled vasoconstrictor receptors, a phenomenon that worsens the ischemic brain damage. Upregulation of contractile endothelin B (ET(B)) and 5-hydroxytryptamine 1B (5-HT(1B......)) receptors has been demonstrated after subarachnoid hemorrhage and global ischemic stroke, but the situation is less clear after focal ischemic stroke. Changes in smooth muscle calcium handling have been implicated in different vascular diseases but have not hitherto been investigated in cerebral arteries...... and extracellular sources, whereas 5-HT(1B) receptor-mediated contraction was solely dependent on extracellular calcium. Organ culture and stroke increased basal intracellular calcium levels in MCA smooth muscle cells and decreased the expression of inositol triphosphate receptor and transient receptor potential...

Serotonin type-1A receptor imaging in depression

International Nuclear Information System (INIS)

Drevets, Wayne C.; Frank, Ellen; Price, Julie C.; Kupfer, David J.; Greer, Phil J.; Mathis, Chester

2000-01-01

Regional 5-hydroxytryptamine 1A (5-HT 1A ) receptor binding potential (BP) of depressed subjects with primary, recurrent, familial mood disorders was compared to that of healthy controls by using positron emission tomography and [carbonyl- 11 C]WAY-100635 {[ 11 C]N-(2-(4-(2-methoxyphenyl)-1-piperazin-1-yl)ethyl)-N-(2-pyridyl) cyclohexanecarboxamide}. The mean 5-HT 1A receptor BP was reduced 42% in the midbrain raphe and 25-33% in limbic and neocortical areas in the mesiotemporal, occipital, and parietal cortex. The magnitude of these abnormalities was most prominent in bipolar depressives and unipolar depressives who had bipolar relatives. These abnormal reductions in 5-HT 1A receptor BP are consistent with in vivo evidence that 5-HT 1A receptor sensitivity is reduced in major depressive disorder and postmortem data showing a widespread deficit of 5-HT 1A receptor expression in primary mood disorders

Endothelin-1 and Exercise Intensity in Sedentary Adolescents with Obesity

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Brooke E. Starkoff

2015-01-01

Full Text Available Inactivity combined with obesity during adolescence increases the risk of future cardiovascular disease. The study purpose was to compare the influence of differing intensities of exercise on endothelial function in sedentary adolescents with obesity. Participants were randomized to one of two groups in a 6-week exercise intervention: moderate intensity (MOD or high intensity interval exercise (HIIE. Endothelial function was assessed pre- and post-intervention via fasted serum levels of endothelin-1 (ET-1. Pre-measures of ET-1 concentrations were elevated at baseline. No significant differences in ET-1 were found between or within exercise groups. However, in the HIIE group, ET-1 was inversely associated with percentages of age predicted maximal heart rate achieved during the intervention (p=0.035, r=-0.567. The exercise interventions did not positively change ET-1 levels, yet participants who exercised at higher intensities in the HIIE group experienced greater decreases in ET-1. Keywords: childhood obesity, endothelial function, high intensity interval exercise

BmpR1A is a major type 1 BMP receptor for BMP-Smad signaling during skull development.

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Pan, Haichun; Zhang, Honghao; Abraham, Ponnu; Komatsu, Yoshihiro; Lyons, Karen; Kaartinen, Vesa; Mishina, Yuji

2017-09-01

Craniosynostosis is caused by premature fusion of one or more sutures in an infant skull, resulting in abnormal facial features. The molecular and cellular mechanisms by which genetic mutations cause craniosynostosis are incompletely characterized, and many of the causative genes for diverse types of syndromic craniosynostosis have not yet been identified. We previously demonstrated that augmentation of BMP signaling mediated by a constitutively active BMP type IA receptor (ca-BmpR1A) in neural crest cells (ca1A hereafter) causes craniosynostosis and superimposition of heterozygous null mutation of Bmpr1a rescues premature suture fusion (ca1A;1aH hereafter). In this study, we superimposed heterozygous null mutations of the other two BMP type I receptors, Bmpr1b and Acvr1 (ca1A;1bH and ca1A;AcH respectively hereafter) to further dissect involvement of BMP-Smad signaling. Unlike caA1;1aH, ca1A;1bH and ca1A;AcH did not restore the craniosynostosis phenotypes. In our in vivo study, Smad-dependent BMP signaling was decreased to normal levels in mut;1aH mice. However, BMP receptor-regulated Smads (R-Smads; pSmad1/5/9 hereafter) levels were comparable between ca1A, ca1A;1bH and ca1A;AcH mice, and elevated compared to control mice. Bmpr1a, Bmpr1b and Acvr1 null cells were used to examine potential mechanisms underlying the differences in ability of heterozygosity for Bmpr1a vs. Bmpr1b or Acvr1 to rescue the mut phenotype. pSmad1/5/9 level was undetectable in Bmpr1a homozygous null cells while pSmad1/5/9 levels did not decrease in Bmpr1b or Acvr1 homozygous null cells. Taken together, our study indicates that different levels of expression and subsequent activation of Smad signaling differentially contribute each BMP type I receptor to BMP-Smad signaling and craniofacial development. These results also suggest differential involvement of each type 1 receptor in pathogenesis of syndromic craniosynostoses. Copyright © 2017 Elsevier Inc. All rights reserved.

Serotonin type-1A receptor imaging in depression

Energy Technology Data Exchange (ETDEWEB)

Drevets, Wayne C. E-mail: drevets@pet.upmc.edu; Frank, Ellen; Price, Julie C.; Kupfer, David J.; Greer, Phil J.; Mathis, Chester

2000-07-01

Regional 5-hydroxytryptamine{sub 1A} (5-HT{sub 1A}) receptor binding potential (BP) of depressed subjects with primary, recurrent, familial mood disorders was compared to that of healthy controls by using positron emission tomography and [carbonyl-{sup 11}C]WAY-100635 {l_brace}[{sup 11}C]N-(2-(4-(2-methoxyphenyl)-1-piperazin-1-yl)ethyl)-N-(2-pyridyl) cyclohexanecarboxamide{r_brace}. The mean 5-HT{sub 1A} receptor BP was reduced 42% in the midbrain raphe and 25-33% in limbic and neocortical areas in the mesiotemporal, occipital, and parietal cortex. The magnitude of these abnormalities was most prominent in bipolar depressives and unipolar depressives who had bipolar relatives. These abnormal reductions in 5-HT{sub 1A} receptor BP are consistent with in vivo evidence that 5-HT{sub 1A} receptor sensitivity is reduced in major depressive disorder and postmortem data showing a widespread deficit of 5-HT{sub 1A} receptor expression in primary mood disorders.

Distortion of maternal-fetal angiotensin II type 1 receptor allele transmission in pre-eclampsia.

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Morgan, L; Crawshaw, S; Baker, P N; Brookfield, J F; Broughton Pipkin, F; Kalsheker, N

1998-01-01

OBJECTIVE: To investigate the fetal angiotensin II type 1 receptor genotype in pre-eclampsia. DESIGN: Case-control study. POPULATION: Forty-one maternal-fetal pairs from pre-eclamptic pregnancies and 80 maternal-fetal pairs from normotensive pregnancies. METHODS: Maternal and fetal DNA was genotyped at three diallelic polymorphisms, at nucleotides 573, 1062, and 1166, in the coding exon of the angiotensin II type 1 receptor gene, and at a dinucleotide repeat polymorphism in its 3' flanking region. RESULTS: Allele and genotype frequencies at the four polymorphic regions investigated did not differ between pre-eclamptic and normotensive groups, in either fetal or maternal samples. Mothers heterozygous for the dinucleotide repeat allele designated A4 transmitted this allele to the fetus in 15 of 18 informative pre-eclamptic pregnancies and in eight of 26 normotensive pregnancies. This was greater than the expected probability in pre-eclamptic pregnancies (p=0.04) and less than expected in normotensive pregnancies (p<0.005). The 573T variant, which is in partial linkage disequilibrium with the A4 allele, showed a similar distortion of maternal-fetal transmission. CONCLUSION: Angiotensin II type 1 receptor gene expression in the fetus may contribute to the aetiology of pre-eclampsia. It is unclear whether susceptibility is conferred by the fetal genotype acting alone, or by allele sharing by mother and fetus. Possible mechanisms for the effect of the angiotensin II type 1 receptor gene are suggested by the association of the 573T variant with low levels of surface receptor expression on platelets. If receptor expression is similarly genetically determined in the placenta, responsiveness to angiotensin II may be affected, with the potential to influence placentation or placental prostaglandin secretion. PMID:9719367

Exercise reduces adipose tissue via cannabinoid receptor type 1 which is regulated by peroxisome proliferator-activated receptor-delta

DEFF Research Database (Denmark)

Yan, Zhen Cheng; Liu, Dao Yan; Zhang, Li Li

2007-01-01

Obesity is one major cardiovascular risk factor. We tested effects of endurance exercise on cannabinoid receptor type 1 (CB1) and peroxisome proliferator-activated receptor-delta (PPAR-delta)-dependent pathways in adipose tissue. Male Wistar rats were randomly assigned to standard laboratory chow...... or a high-fat diet without and with regular endurance exercise. Exercise in rats on high-fat diet significantly reduced visceral fat mass, blood pressure, and adipocyte size (each p...

Modelling of absorption, distribution and physicochemical properties of AT1 receptor antagonists / Modelovanie absorpcie, distribúcie a fyzikálnochemických vlastnosti antagonistov AT1 receptorov

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Ježko Pavol

2015-12-01

Full Text Available The theoretical chemistry methods were used to elucidate absorption, distribution and physicochemical properties of AT1 receptor antagonists and dual angiotensin II and endothelin A receptor antagonist (PS-433540. Computed partition coefficients (ALOGPS method studied for drugs varied between 2.98 and 6.66. Neutral compounds are described as lipophilic drugs. Telmisartan is a drug with the highest lipophilicity. The neutral forms of the studied AT1 receptor antagonists are practically insoluble in water, and their computed solubilities is in interval between 2.04 and 22.65 mg/l (ALOGpS method. The calculated pKa values for tetrazolyle moiety are in the range 3.92-5.00 and for carboxylic moiety 3.12-5.50. Telmisartan (polar surface area = 72.95 A and irbesartan (polar surface area = 87.14 A belong to the AT1 receptor antagonists with increased absorption.

Intrahippocampal Injection of Endothelin-1: A New Model of Ischemia-induced Seizures in Immature Rats

Czech Academy of Sciences Publication Activity Database

Tsenov, Grygoriy; Máttéffyová, Adéla; Mareš, Pavel; Otáhal, Jakub; Kubová, Hana

2007-01-01

Roč. 48, Suppl.5 (2007), s. 7-13 ISSN 0013-9580 R&D Projects: GA MŠk(CZ) LC554; GA ČR(CZ) GA305/06/0713; GA ČR(CZ) GD305/03/H148 Institutional research plan: CEZ:AV0Z50110509 Keywords : endothelin-1 * epileptic seizures * immature rats Subject RIV: ED - Physiology Impact factor: 3.569, year: 2007

Characterization of [125I]endothelin-1 binding sites in rat cardiac membrane fragments

International Nuclear Information System (INIS)

Gu, X.H.; Casley, D.J.; Nayler, W.G.

1989-01-01

Standard binding and displacement techniques were used to identify high-affinity binding sites for [ 125 I]-labeled endothelin-1 (ET-1) in membranes harvested from the hearts of adult female Sprague-Dawley rats. A single population of binding sites was identified, with a KD of 0.20 +/- 0.03 nM at 37 degrees C, and a Bmax of 93.5 +/- 6.4 fmol/mg protein. Bound [ 125 I]ET-1 was displaced by ET-1 (10(-13)-10(-8) M), with a Ki of 0.08 nM. Neither (-)Bay K 8644 (10(-11)-10(-5) M), prenylamine (10(-11)-10(-5) M), (+)-cis-diltiazem (10(-10)-10(-5) M), (-)D888 (10(-10)-10(-5) M), nicardipine (10(-10)-10(-5) M), lidoflazine (10(-11)-10(-5) M), flunarizine (10(-11)-10(-5) M), omega-conotoxin (10(-13)-10(-7) M), nor prazosin (10(-10)-10(-5) M) displaced the bound ligand. Binding occurred in the absence of Ca2+ and was absent in heat-denatured membranes. These results are interpreted to mean that [ 125 I]ET-1 binds to a single class of high-affinity binding sites that differ from those occupied by known regulators of voltage activated L- and N-type Ca2+ channels

Amelioration of cold injury-induced cortical brain edema formation by selective endothelin ETB receptor antagonists in mice.

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Shotaro Michinaga

Full Text Available Brain edema is a potentially fatal pathological condition that often occurs in stroke and head trauma. Following brain insults, endothelins (ETs are increased and promote several pathophysiological responses. This study examined the effects of ETB antagonists on brain edema formation and disruption of the blood-brain barrier in a mouse cold injury model (Five- to six-week-old male ddY mice. Cold injury increased the water content of the injured cerebrum, and promoted extravasation of both Evans blue and endogenous albumin. In the injury area, expression of prepro-ET-1 mRNA and ET-1 peptide increased. Intracerebroventricular (ICV administration of BQ788 (ETB antagonist, IRL-2500 (ETB antagonist, or FR139317 (ETA antagonist prior to cold injury significantly attenuated the increase in brain water content. Bolus administration of BQ788, IRL-2500, or FR139317 also inhibited the cold injury-induced extravasation of Evans blue and albumin. Repeated administration of BQ788 and IRL-2500 beginning at 24 h after cold injury attenuated both the increase in brain water content and extravasation of markers. In contrast, FR139317 had no effect on edema formation when administrated after cold injury. Cold injury stimulated induction of glial fibrillary acidic protein-positive reactive astrocytes in the injured cerebrum. Induction of reactive astrocytes after cold injury was attenuated by ICV administration of BQ788 or IRL-2500. These results suggest that ETB receptor antagonists may be an effective approach to ameliorate brain edema formation following brain insults.

Enhanced Human-Type Receptor Binding by Ferret-Transmissible H5N1 with a K193T Mutation.

Science.gov (United States)

Peng, Wenjie; Bouwman, Kim M; McBride, Ryan; Grant, Oliver C; Woods, Robert J; Verheije, Monique H; Paulson, James C; de Vries, Robert P

2018-05-15

All human influenza pandemics have originated from avian influenza viruses. Although multiple changes are needed for an avian virus to be able to transmit between humans, binding to human-type receptors is essential. Several research groups have reported mutations in H5N1 viruses that exhibit specificity for human-type receptors and promote respiratory droplet transmission between ferrets. Upon detailed analysis, we have found that these mutants exhibit significant differences in fine receptor specificity compared to human H1N1 and H3N2 and retain avian-type receptor binding. We have recently shown that human influenza viruses preferentially bind to α2-6-sialylated branched N-linked glycans, where the sialic acids on each branch can bind to receptor sites on two protomers of the same hemagglutinin (HA) trimer. In this binding mode, the glycan projects over the 190 helix at the top of the receptor-binding pocket, which in H5N1 would create a stearic clash with lysine at position 193. Thus, we hypothesized that a K193T mutation would improve binding to branched N-linked receptors. Indeed, the addition of the K193T mutation to the H5 HA of a respiratory-droplet-transmissible virus dramatically improves both binding to human trachea epithelial cells and specificity for extended α2-6-sialylated N-linked glycans recognized by human influenza viruses. IMPORTANCE Infections by avian H5N1 viruses are associated with a high mortality rate in several species, including humans. Fortunately, H5N1 viruses do not transmit between humans because they do not bind to human-type receptors. In 2012, three seminal papers have shown how these viruses can be engineered to transmit between ferrets, the human model for influenza virus infection. Receptor binding, among others, was changed, and the viruses now bind to human-type receptors. Receptor specificity was still markedly different compared to that of human influenza viruses. Here we report an additional mutation in ferret

Role of σ1 Receptors in Learning and Memory and Alzheimer's Disease-Type Dementia.

Science.gov (United States)

Maurice, Tangui; Goguadze, Nino

2017-01-01

The present chapter will review the role of σ 1 receptor in learning and memory and neuroprotection , against Alzheimer's type dementia. σ 1 Receptor agonists have been tested in a variety of pharmacological and pathological models of learning impairments in rodents these last past 20 years. Their anti-amnesic effects have been explained by the wide-range modulatory role of σ 1 receptors on Ca 2+ mobilizations, neurotransmitter responses, and particularly glutamate and acetylcholine systems, and neurotrophic factors. Recent observations from genetic and pharmacological studies have shown that σ 1 receptor can also be targeted in neurodegenerative diseases, and particularly Alzheimer's disease . Several compounds, acting partly through the σ 1 receptor, have showed effective neuroprotection in transgenic mouse models of Alzheimer's disease . We will review the data and discuss the possible mechanisms of action, particularly focusing on oxidative stress and mitochondrial integrity, trophic factors and a novel hypothesis suggesting a functional interaction between the σ 1 receptor and α 7 nicotinic acetylcholine receptor. Finally, we will discuss the pharmacological peculiarities of non-selective σ 1 receptor ligands, now developed as neuroprotectants in Alzheimer's disease , and positive modulators, recently described and that showed efficacy against learning and memory deficits.

Polyphenol fraction of extra virgin olive oil protects against endothelial dysfunction induced by high glucose and free fatty acids through modulation of nitric oxide and endothelin-1

OpenAIRE

Storniolo, Carolina Emilia; Roselló-Catafau, Joan; Pintó, Xavier; Mitjavila, María Teresa; Moreno, Juan José

2014-01-01

© 2014 The Authors. Epidemiological and clinical studies have reported that olive oil reduces the incidence of cardiovascular disease. However, the mechanisms involved in this beneficial effect have not been delineated. The endothelium plays an important role in blood pressure regulation through the release of potent vasodilator and vasoconstrictor agents such as nitric oxide (NO) and endothelin-1 (ET-1), respectively, events that are disrupted in type 2 diabetes. Extra virgin olive oil conta...

Involvement of α₂-adrenoceptors, imidazoline, and endothelin-A receptors in the effect of agmatine on morphine and oxycodone-induced hypothermia in mice.

Science.gov (United States)

Bhalla, Shaifali; Andurkar, Shridhar V; Gulati, Anil

2013-10-01

Potentiation of opioid analgesia by endothelin-A (ET(A)) receptor antagonist, BMS182874, and imidazoline receptor/α₂-adrenoceptor agonists such as clonidine and agmatine are well known. It is also known that agmatine blocks morphine hyperthermia in rats. However, the effect of agmatine on morphine or oxycodone hypothermia in mice is unknown. The present study was carried out to study the role of α₂-adrenoceptors, imidazoline, and ET(A) receptors in morphine and oxycodone hypothermia in mice. Body temperature was determined over 6 h in male Swiss Webster mice treated with morphine, oxycodone, agmatine, and combination of agmatine with morphine or oxycodone. Yohimbine, idazoxan, and BMS182874 were used to determine involvement of α₂-adrenoceptors, imidazoline, and ET(A) receptors, respectively. Morphine and oxycodone produced significant hypothermia that was not affected by α₂-adrenoceptor antagonist yohimbine, imidazoline receptor/α₂ adrenoceptor antagonist idazoxan, or ET(A) receptor antagonist, BMS182874. Agmatine did not produce hypothermia; however, it blocked oxycodone but not morphine-induced hypothermia. Agmatine-induced blockade of oxycodone hypothermia was inhibited by idazoxan and yohimbine. The blockade by idazoxan was more pronounced compared with yohimbine. Combined administration of BMS182874 and agmatine did not produce changes in body temperature in mice. However, when BMS182874 was administered along with agmatine and oxycodone, it blocked agmatine-induced reversal of oxycodone hypothermia. This is the first report demonstrating that agmatine does not affect morphine hypothermia in mice, but reverses oxycodone hypothermia. Imidazoline receptors and α₂-adrenoceptors are involved in agmatine-induced reversal of oxycodone hypothermia. Our findings also suggest that ET(A) receptors may be involved in blockade of oxycodone hypothermia by agmatine. © 2012 The Authors Fundamental and Clinical Pharmacology © 2012 Société Française de

Neurobiology of opioid withdrawal: Role of the endothelin system.

Science.gov (United States)

Bhalla, Shaifali; Andurkar, Shridhar V; Gulati, Anil

2016-08-15

Morphine and oxycodone are potent opioid analgesics most commonly used for the management of moderate to severe acute and chronic pain. Their clinical utility is limited by undesired side effects like analgesic tolerance, dependence, and withdrawal. We have previously demonstrated that endothelin-A (ETA) receptor antagonists potentiate opioid analgesia and eliminate analgesic tolerance. Mechanistically, G proteins and regulatory proteins such as β-arrestins have shown to play an important role in mediating opioid tolerance, dependence, and withdrawal. Recently, the involvement of central ET mechanisms in opioid withdrawal was investigated. ETA receptor antagonist was shown to block majority of the signs and symptoms associated with opioid withdrawal. This review focuses on ET as one of the potential novel strategies to manage the challenge of opioid withdrawal. An overview of additional players in this process (G proteins and β-arrestin2), and the possible therapeutic implications of these findings are presented. Copyright © 2016 Elsevier Inc. All rights reserved.

Treatment of type 2 diabetes with glucagon-like peptide-1 receptor agonists

DEFF Research Database (Denmark)

Hansen, K B; Knop, F K; Holst, Jens Juul

2009-01-01

of hypoglycaemia with GLP-1 receptor agonists is low, the compounds have clinically relevant effects on body weight, and data are suggesting beneficial effects on cardiovascular risk factors. Exenatide was released in 2005 for the treatment of type 2 diabetes and liraglutide is expected to be approved by the Food......The incretin system is an area of great interest for the development of new therapies for the management of type 2 diabetes. Existing antidiabetic drugs are often insufficient at getting patients to glycaemic goals. Furthermore, current treatment modalities are not able to prevent the continued...... ongoing decline in pancreatic beta-cell function and, lastly, they have a number of side effects including hypoglycaemia and weight gain. Glucagon-like peptide-1 (GLP-1) receptor agonists are a new class of pharmacological agents, which improve glucose homeostasis in a multifaceted way. Their effects...

Expression of Angiotensin II Types 1 and 2 Receptors in Endometriotic Lesions.

Science.gov (United States)

Nakao, Takehiro; Chishima, Fumihisa; Sugitani, Masahiko; Tsujimura, Ryusuke; Hayashi, Chuyu; Yamamoto, Tatsuo

2017-01-01

The aim of this study was to evaluate the gene and protein expression of angiotensin type (AT) 1, AT2 receptors in endometriotic lesions and its relation to prostaglandin (PG) synthases. Endometriosis samples were obtained from 32 patients with endometriotic cysts. Endometrial tissues were obtained during operations for benign gynecological conditions. The expression of the AT1 and AT2 receptor mRNA and that of PG-endoperoxide synthase 2 and microsomal PGE2 synthase-1 (mPGES-1) was examined by quantitative RT-PCR. Immunohistochemical staining was performed for these receptors. AT1 and AT2 receptor proteins were mostly located in endometrial glandular epithelium and some stromal cells. Immunoreactivity of the receptor proteins was observed in both the eutopic endometrium and endometriotic lesions. The AT1/AT2 ratio in endometriotic cysts (median 7.29, range 1.88-187.60) was significantly increased compared with that in the eutopic endometrium in the proliferative-phase in controls (median 1.01, range 0.37-2.09, p < 0.001). There was a relationship between the AT1 mRNA expression and that of mPGES-1 mRNA in the endometriotic cysts (r = 0.394089, p < 0.05). There was a significant relationship between the mRNA expression of the AT2 receptor and that of mPGES-1 in eutopic endometrium of non-endometriotic control (r = 0.610714, p < 0.05). Renin-angiotensin system may play an important role in the pathophysiology of endometriosis. © 2016 S. Karger AG, Basel.

Effects of age and caloric restriction in the vascular response of renal arteries to endothelin-1 in rats.

Science.gov (United States)

Amor, Sara; García-Villalón, Angel Luis; Rubio, Carmen; Carrascosa, Jose Ma; Monge, Luis; Fernández, Nuria; Martín-Carro, Beatriz; Granado, Miriam

2017-02-01

Cardiovascular alterations are the most prevalent cause of impaired physiological function in aged individuals with kidney being one the most affected organs. Aging-induced alterations in renal circulation are associated with a decrease in endothelium-derived relaxing factors such as nitric oxide (NO) and with an increase in contracting factors such as endothelin-1(ET-1). As caloric restriction (CR) exerts beneficial effects preventing some of the aging-induced alterations in cardiovascular system, the aim of this study was to analyze the effects of age and caloric restriction in the vascular response of renal arteries to ET-1 in aged rats. Vascular function was studied in renal arteries from 3-month-old Wistar rats fed ad libitum (3m) and in renal arteries from 8-and 24-month-old Wistar rats fed ad libitum (8m and 24m), or subjected to 20% caloric restriction during their three last months of life (8m-CR and 24m-CR). The contractile response to ET-1 was increased in renal arteries from 8m and 24m compared to 3m rats. ET-1-induced contraction was mediated by ET-A receptors in all experimental groups and also by ET-B receptors in 24m rats. Caloric restriction attenuated the increased contraction to ET-1 in renal arteries from 8m but not from 24m rats possibly through NO release proceeding from ET-B endothelial receptors. In 24m rats, CR did not attenuate the aging-increased response of renal arteries to ET-1, but it prevented the aging-induced increase in iNOS mRNA levels and the aging-induced decrease in eNOS mRNA levels in arterial tissue. In conclusion, aging is associated with an increased response to ET-1 in renal arteries that is prevented by CR in 8m but not in 24m rats. Copyright © 2016 Elsevier Inc. All rights reserved.

Liberación de endotelina-1 por angiotensina ll en miocitos cardíacos aislados Angiotensin II-induced endothelin-1 release in cardiac myocytes

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María C. Villa-Abrille

2006-06-01

Full Text Available Muchos de los efectos de la angiotensina II (Ang II son mediados en realidad por la acción de endotelina (ET endógena liberada y/o producida en respuesta a la Ang II. En este trabajo evaluamos la interacción Ang II/ET-1, sus consecuencias en la contractilidad cardíaca y el papel de las especies reactivas del oxígeno (EROs. Se usaron cardiomiocitos aislados de gato. La Ang II, 1 nM, produjo un efecto inotrópico positivo (EIP de 31.8±3.8% que fue cancelado por inhibición de los receptores AT1, de los receptores de ET, del intercambiador Na+/H+ (NHE, del modo inverso del intercambiador Na+/Ca2+ (NCX o por el secuestro de EROs. La Ang II, 100 nM, produjo un EIP de 70.5±7.6% que fue cancelado por inhibición de los receptores AT1 y bloqueado en parte por inhibición de los receptores de ET, del NHE, del modo inverso del NCX o por el secuestro de EROs. La Ang II, 1 nM, incrementó el ARNm de la preproET-1 lo cual fue anulado por el bloqueo de los receptores AT1. Los resultados permiten concluir que el EIP de la Ang II es debido a la acción de la ET-1 endógena liberada/formada por la Ang II. La ET-1 produce: estimulación del NHE, activación del modo inverso del NCX y un consecuente EIP. Dentro de esta cascada también participarían los EROs.Many of the effects thought to be due to angiotensin II (Ang II are due to the release/formation of endothelin (ET. We tested whether Ang II elicits its positive inotropic effect (PIE by the action of endogenous ET-1 and the role played by the reactive oxygen species (ROS in this mechanism. Experiments were performed in cat isolated ventricular myocytes in which sarcomere shortening (SS was measured to asses contractility after pharmacological interventions and the effect of Ang II on inotropism were analyzed. Ang II 1 nM increased SS by 31.8±3.8% (p<0.05. This PIE was cancelled by AT1 receptor blockade, by ET-1 receptors blockade, by Na+/H+ exchanger (NHE inhibition, by reverse mode Na+/Ca2

Correlation of Endothelin-1 Concentration and Angiotensin-Converting Enzyme Activity with the Staging of Liver Fibrosis

OpenAIRE

Kardum, Duško; Fabijanić, Damir; Lukić, Anita; Romić, Željko; Petrovečki, Mladen; Bogdanović, Zoran; Jurić, Klara; Urek-Crnčević, Marija; Banić, Marko

2012-01-01

Increased serum angiotensin-converting enzyme (SACE) activity and serum concentration of endothelin-1 (ET-1) were found in liver cirrhosis. We investigated a correlation between the different stages of liver fibrosis and SACE activity and serum ET-1 concentration. Seventy patients with pathohistologically established chronic liver disease were divided in three groups according to Ishak criteria for liver fibrosis: minimal fibrosis (Ishak score 0–1, n=20), medium fibrosis (Ishak sc...

A de novo deletion mutation in SOX10 in a Chinese family with Waardenburg syndrome type 4.

Science.gov (United States)

Wang, Xiong; Zhu, Yaowu; Shen, Na; Peng, Jing; Wang, Chunyu; Liu, Haiyi; Lu, Yanjun

2017-01-27

Waardenburg syndrome type 4 (WS4) or Waardenburg-Shah syndrome is a rare genetic disorder with a prevalence of <1/1,000,000 and characterized by the association of congenital sensorineural hearing loss, pigmentary abnormalities, and intestinal aganglionosis. There are three types of WS4 (WS4A-C) caused by mutations in endothelin receptor type B, endothelin 3, and SRY-box 10 (SOX10), respectively. This study investigated a genetic mutation in a Chinese family with one WS4 patient in order to improve genetic counselling. Genomic DNA was extracted, and mutation analysis of the three WS4 related genes was performed using Sanger sequencing. We detected a de novo heterozygous deletion mutation [c.1333delT (p.Ser445Glnfs*57)] in SOX10 in the patient; however, this mutation was absent in the unaffected parents and 40 ethnicity matched healthy controls. Subsequent phylogenetic analysis and three-dimensional modelling of the SOX10 protein confirmed that the c.1333delT heterozygous mutation was pathogenic, indicating that this mutation might constitute a candidate disease-causing mutation.

beta-Arrestin 1 and 2 stabilize the angiotensin II type I receptor in distinct high-affinity conformations

DEFF Research Database (Denmark)

Sanni, S J; Hansen, J T; Bonde, M M

2010-01-01

The angiotensin II type 1 (AT(1)) receptor belongs to family A of 7 transmembrane (7TM) receptors. The receptor has important roles in the cardiovascular system and is commonly used as a drug target in cardiovascular diseases. Interaction of 7TM receptors with G proteins or beta-arrestins often...

Investigation of role of plasma endothelin in diabetes mellitus patients complicated with angiocardiopathy

International Nuclear Information System (INIS)

Cong Jingbo; Wang Zhihua; Niu Aijun

2001-01-01

Objective: To study the role of plasma endothelin in diabetes mellitus (DM) patients complicated with angiocardiopathy. Methods: Plasma endothelin levels were determined by radioimmunoassay in 34 diabetics, 27 diabetics complicated with angiocardiopathy and in 30 controls. Results: Plasma endothelin levels in both diabetic groups were significantly higher than those in normal subjects (p < 0.01); plasma endothelin levels in DM patients complicated with angiocardiopathy were significantly higher than those in patients with diabetes only (p < 0.01). Conclusion: Plasma endothelin was of important role in the pathogenesis of DM complicated with angiocardiopathy and could be used as an early and sensitive marker

Erratum Aldosterone synthase C-344T, angiotensin II type 1 receptor ...

Indian Academy of Sciences (India)

Aldosterone synthase C-344T, angiotensin II type 1 receptor A1166C and 11-β hydroxysteroid dehydrogenase G534A gene polymorphisms and essential hypertension in the population of Odisha, India. Manisha Patnaik, Pallabi Pati, Surendra N. Swain, Manoj K. Mohapatra, Bhagirathi Dwibedi, Shantanu K. Kar.

High density lipoprotein stimulated migration of macrophages depends on the scavenger receptor class B, type I, PDZK1 and Akt1 and is blocked by sphingosine 1 phosphate receptor antagonists.

Directory of Open Access Journals (Sweden)

Aishah Al-Jarallah

Full Text Available HDL carries biologically active lipids such as sphingosine-1-phosphate (S1P and stimulates a variety of cell signaling pathways in diverse cell types, which may contribute to its ability to protect against atherosclerosis. HDL and sphingosine-1-phosphate receptor agonists, FTY720 and SEW2871 triggered macrophage migration. HDL-, but not FTY720-stimulated migration was inhibited by an antibody against the HDL receptor, SR-BI, and an inhibitor of SR-BI mediated lipid transfer. HDL and FTY720-stimulated migration was also inhibited in macrophages lacking either SR-BI or PDZK1, an adaptor protein that binds to SR-BI's C-terminal cytoplasmic tail. Migration in response to HDL and S1P receptor agonists was inhibited by treatment of macrophages with sphingosine-1-phosphate receptor type 1 (S1PR1 antagonists and by pertussis toxin. S1PR1 activates signaling pathways including PI3K-Akt, PKC, p38 MAPK, ERK1/2 and Rho kinases. Using selective inhibitors or macrophages from gene targeted mice, we demonstrated the involvement of each of these pathways in HDL-dependent macrophage migration. These data suggest that HDL stimulates the migration of macrophages in a manner that requires the activities of the HDL receptor SR-BI as well as S1PR1 activity.

A single mutation in Taiwanese H6N1 influenza hemagglutinin switches binding to human-type receptors

Energy Technology Data Exchange (ETDEWEB)

de Vries, Robert P.; Tzarum, Netanel; Peng, Wenjie; Thompson, Andrew J.; Ambepitiya Wickramasinghe, Iresha N.; de la Pena, Alba T. Torrents; van Breemen, Marielle J.; Bouwman, Kim M.; Zhu, Xueyong; McBride, Ryan; Yu, Wenli; Sanders, Rogier W.; Verheije, Monique H.; Wilson, Ian A.; Paulson, James C.

2017-07-10

In June 2013, the first case of human infection with an avian H6N1 virus was reported in a Taiwanese woman. Although this was a single non-fatal case, the virus continues to circulate in Taiwanese poultry. As with any emerging avian virus that infects humans, there is concern that acquisition of human-type receptor specificity could enable transmission in the human population. Despite mutations in the receptor-binding pocket of the human H6N1 isolate, it has retained avian-type (NeuAcα2-3Gal) receptor specificity. However, we show here that a single nucleotide substitution, resulting in a change from Gly to Asp at position 225 (G225D), completely switches specificity to human-type (NeuAcα2-6Gal) receptors. Significantly, G225D H6 loses binding to chicken trachea epithelium and is now able to bind to human tracheal tissue. Structural analysis reveals that Asp225 directly interacts with the penultimate Gal of the human-type receptor, stabilizing human receptor binding.

Endothelins in chronic liver disease

DEFF Research Database (Denmark)

Møller, Søren; Henriksen, Jens Henrik

1996-01-01

This review describes recent progress in the accumulation of knowledge about the endothelins (ETs), a family of vasoactive 21-amino acid polypeptides, in chronic liver disease. Particular prominence is given to the dynamics of ET-1 and ET-3 and their possible relation to the disturbed circulation...... renal failure. Studies on liver biopsies have revealed synthesis of ET-1 in hepatic endothelial and other cells, and recent investigations have identified the hepatosplanchnic system as a major source of ET-1 and ET-3 spillover into the circulation, with a direct relation to portal venous hypertension...

Relaxing Responses to Hydrogen Peroxide and Nitric Oxide in Human Pericardial Resistance Arteries Stimulated with Endothelin-1

DEFF Research Database (Denmark)

Leurgans, Thomas M; Bloksgaard, Maria; Irmukhamedov, Akhmadjon

2018-01-01

In human pericardial resistance arteries, effects of the endothelium-dependent vasodilator bradykinin are mediated by NO during contraction induced by K(+) or the TxA2 analogue U46619 and by H2 O2 during contraction by endothelin-1 (ET-1), respectively. We tested the hypotheses that ET-1 reduces...... also acts as an endothelium-dependent vasodilator. This article is protected by copyright. All rights reserved....

Increasing plasma fibrinogen, but unchanged levels of intraplatelet cyclic nucleotides, plasma endothelin-1, factor VII, and neopterin during cholesterol lowering with fluvastatin.

Science.gov (United States)

Gottsäter, A; Anwaar, I; Lind, P; Mattiasson, I; Lindgärde, F

1999-04-01

Lipid-lowering statin treatment reduces cardiovascular morbidity and mortality and improves endothelial function in patients with hypercholesterolemia. The aim of the present study was to evaluate plasma levels of fibrinogen, factor VII, and the macrophage-derived inflammatory mediator neopterin during lipid lowering. In addition, the endothelial production of platelet antiaggregatory and vasodilatory factors such as nitric oxide and prostacyclin, and vasoconstrictive factors such as endothelin-1, was assessed. Plasma fibrinogen, factor VII, endothelin-1, and the neopterin and intraplatelet nitric oxide and prostacyclin mediators cyclic 3'-5'guanosine monophosphate (cGMP) and cyclic 3'-5'adenosine monophosphate (cAMP) were measured before and 6 months after the institution of treatment with fluvastatin in 17 patients (eight men and nine women, median age 60 years) with vascular disease and previously untreated hypercholesterolemia. After 6 months, a decrease of 1.62 mmol/l [1.26-2.18 (19%); P factor VII [from 1.14 IE/ml (0.58-1.38) to 1.22 IE/ml (0.96-1.46); NS], or plasma neopterin [from 8.6 nmol/l (7.1-11.5) to 8.7 nmol/l (7.9-11.3); NS]. In conclusion, during cholesterol-lowering treatment with fluvastatin, plasma levels of fibrinogen increased whereas intraplatelet cyclic nucleotide levels and plasma endothelin-1, factor VII and neopterin levels were unchanged.

Stimulation of Transforming Growth Factor-β1-Induced Endothelial-To-Mesenchymal Transition and Tissue Fibrosis by Endothelin-1 (ET-1): A Novel Profibrotic Effect of ET-1.

Science.gov (United States)

Wermuth, Peter J; Li, Zhaodong; Mendoza, Fabian A; Jimenez, Sergio A

2016-01-01

TGF-β-induced endothelial-to-mesenchymal transition (EndoMT) is a newly recognized source of profibrotic activated myofibroblasts and has been suggested to play a role in the pathogenesis of various fibrotic processes. Endothelin-1 (ET-1) has been implicated in the development of tissue fibrosis but its participation in TGF-β-induced EndoMT has not been studied. Here we evaluated the role of ET-1 on TGF-β1-induced EndoMT in immunopurified CD31+/CD102+ murine lung microvascular endothelial cells. The expression levels of α-smooth muscle actin (α-SMA), of relevant profibrotic genes, and of various transcription factors involved in the EndoMT process were assessed employing quantitative RT-PCR, immunofluorescence histology and Western blot analysis. TGF-β1 caused potent induction of EndoMT whereas ET-1 alone had a minimal effect. However, ET-1 potentiated TGF-β1-induced EndoMT and TGF-β1-stimulated expression of mesenchymal cell specific and profibrotic genes and proteins. ET-1 also induced expression of the TGF-β receptor 1 and 2 genes, suggesting a plausible autocrine mechanism to potentiate TGF-β-mediated EndoMT and fibrosis. Stimulation of TGF-β1-induced skin and lung fibrosis by ET-1 was confirmed in vivo in an animal model of TGF-β1-induced tissue fibrosis. These results suggest a novel role for ET-1 in the establishment and progression of tissue fibrosis.

LPS from Porphyromonas gingivalis increases the sensitivity of contractile response mediated by endothelin-B (ET(B)) receptors in cultured endothelium-intact rat coronary arteries

DEFF Research Database (Denmark)

Ghorbani, Bahareh; Holmstrup, Palle; Edvinsson, Lars

2010-01-01

The purpose of our study was to examine if lipopolysaccharide (LPS) from Porphyromonas gingivalis (P.g.) modifies the vasomotor responses to Endothelin-1 (ET-1) and Sarafotoxin 6c (S6c) in rat coronary arteries. The arteries were studied directly or following organ culture for 24h in absence...

Purslane Effect on GLP-1 and GLP-1 receptor in type 2 diabetes

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Roja Daliri

2013-01-01

Full Text Available Abstract:Background: The aim of this study was to examine the effect of purslane seeds in glucagon-like peptide-1 concentration and glucagon-like peptide-1 receptor in women with diabetes.Methods: This was a quasi-experimental study. The population was consisted of the city of Sari where diabetic women with diabetes II who had no history of using purslane seeds. All individuals used the same dose of metformin under the specialist supervision. Among these individuals, 16 were assigned at random to Purslane group and control group. The purslane group consumed 2.5 grams Purslane with lunch and along with 5 grams of purslane (Portulaca oleracea seeds 7.5 g daily with dinner meals twice daily for 8 weeks. Blood sample was taken before and after 8 weeks, after 12 hours of fasting to 5 ml of the left brachial vein.Results: After 8 weeks using purslane seeds in the experimental group, a significant increase was seen in glucagon-like peptide-1 concentrations (p<0.007, but there was no significant difference in the concentration of glucagon-like peptide-1 receptor (p <0.455. No significant relationship was found between changes in glucagon-like peptide-1 and its receptor.Conclusion: The use of purslane seeds improved Type II diabetes; therefore it can be effective in improving the health of women with diabetes.

Association of endothelin-1 expression and cartilaginous endplate degeneration in humans.

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Wei Yuan

Full Text Available BACKGROUND: Inflammatory cytokines are involved in intervertebral disc (IVD degeneration. Endothelin-1 (ET-1, a 21-amino-acid cytokine implicated with cartilage degradation, is secreted by vascular endothelial cells and also by many other cell types. The expression of ET-1 in human IVD cartilage endplate (CEP and its role in disc degeneration have not been explored. METHODS AND FINDINGS: The expression of ET-1 in degenerated CEP was analyzed by immunohistochemical staining and Western blotting; ET-1 was demonstrated in cartilaginous endplate cells (CECs by immunofluorescent staining. The ET-1 mRNA expression and protein production by CECs stimulated by tumor necrosis factor alpha (TNF-α, a pro-inflammatory cytokine, were determined by real-time PCR analysis and Western blotting, respectively. The matrix metalloprotease-1 (MMP-1, MMP-13 and tissue inhibitor of metalloproteases-1 (TIMP-1 levels in the supernatant of cultured CECs treated with ET-1 were determined using enzyme-linked immunosorbent assays. Nitric oxide (NO release and nitric oxide synthase (NOS activity were measured using a spectrophotometric assay. The apoptosis of CECs by ET-1 was measured by an Annexin V-FITC detection assay. The production of ET-1 in degenerated cartilage endplate was significantly higher than normal CEP. The results showed that ET-1 was expressed by CECs and modulated by TNF-α in a dose-dependent manner. ET-1 increased production of MMP-1 and MMP-13, decreased TIMP-1 production, and induced NO and NOS release by cultured CECs. The direct stimulation of CECs by ET-1 did not promote cell apoptosis. CONCLUSION: The study results suggest that ET-1 played a pivotal role in human CEP degeneration, and may be a new target for development of therapies for this condition.

Endothelin-1 stimulates catalase activity through the PKCδ mediated phosphorylation of Serine 167

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Rafikov, Ruslan; Kumar, Sanjiv; Aggarwal, Saurabh; Hou, Yali; Kangath, Archana; Pardo, Daniel; Fineman, Jeffrey R.; Black, Stephen M.

2013-01-01

Our previous studies have shown that endothelin-1 (ET-1) stimulates catalase activity in endothelial cells and lambs with acute increases in pulmonary blood flow (PBF), without altering gene expression. The purpose of this study was to investigate the molecular mechanism by which this occurs. Exposing pulmonary arterial endothelial cells (PAEC) to ET-1 increased catalase activity and decreased cellular hydrogen peroxide (H2O2) levels. These changes correlated with an increase in serine phosphorylated catalase. Using the inhibitory peptide δV1.1, this phosphorylation was shown to be PKCδ dependent. Mass spectrometry identified serine167 as the phosphorylation site. Site-directed mutagenesis was used to generate a phospho-mimic (S167D) catalase. Activity assays using recombinant protein purified from E.coli or transiently transfected COS-7 cells, demonstrated that S167D-catalase had an increased ability to degrade H2O2 compared to the wildtype enzyme. Using a phospho-specific antibody, we were able to verify that pS167 catalase levels are modulated in lambs with acute increases in PBF in the presence and absence of the ET receptor antagonist, tezosentan. S167 is being located on the dimeric interface suggesting it could be involved in regulating the formation of catalase tetramers. To evaluate this possibility we utilized analytical gel-filtration to examine the multimeric structure of recombinant wildtype- and S167D-catalase. We found that recombinant wildtype catalase was present as a mixture of monomers and dimers while S167D catalase was primarily tetrameric. Further, the incubation of wildtype catalase with PKCδ was sufficient to convert wildtype catalase into a tetrameric structure. In conclusion, this is the first report indicating that the phosphorylation of catalase regulates its multimeric structure and activity. PMID:24211614

Correlations between plasma endothelin-1 levels and breakthrough pain in patients with cancer

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Yan XB

2015-12-01

Full Text Available Xue-bin Yan, Tuo-chao Peng, Dong Huang Department of Anesthesiologist, The Third Xiangya Hospital of Central South University, Changsha, Hunan Province, People’s Republic of China Abstract: Endothelin-1 (ET-1 may be involved in driving pain in patients with advanced cancer. However, a few studies focus on the role of ET-1 in breakthrough pain (BP. The aim of this pivotal study was to explore the correlation between the plasma (ET-1 level and BP intensity. A total of 40 patients were enrolled in the study, and they were divided into two groups: BP group and non-BP group. Moreover, 20 healthy adults were used as the normal control group. Pain intensity was measured using visual analog scale (VAS scores of 1–10. Plasma ET-1 levels were detected by an ET radioimmunoassay kit. Subsequently, the correlation of ET-1 level with the VAS score and cancer types was analyzed by Pearson’s correlation coefficient. The plasma ET-1 level in the BP group (35.31±8.02 pg/mL was higher than that in the non-BP group (29.51±6.78 pg/mL and the normal control group (24.77±10.10 pg/mL, P<0.05. In addition, the VAS score in the BP group (7.45±0.82 was higher than that in the non-BP group (2.80±1.23, P<0.05. The plasma ET-1 level was positively correlated with the VAS score of the BP group (Pearson’s r=0.42. There was no significant correlation between the plasma ET-1 level and VAS score of the non-BP group (Pearson’s r=–0.22 or/and cancer types (P>0.05. The elevated plasma ET-1 levels were positively related to BP, and targeting ET-1 may provide a novel pain-reducing therapeutic treatment in BP. Keywords: visual analog scale, correlation, cancer types, background pain

Normalization of hemoglobin-based oxygen carrier-201 induced vasoconstriction: targeting nitric oxide and endothelin.

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Taverne, Yannick J; de Wijs-Meijler, Daphne; Te Lintel Hekkert, Maaike; Moon-Massat, Paula F; Dubé, Gregory P; Duncker, Dirk J; Merkus, Daphne

2017-05-01

Hemoglobin-based oxygen carrier (HBOC)-201 is a cell-free modified hemoglobin solution potentially facilitating oxygen uptake and delivery in cardiovascular disorders and hemorrhagic shock. Clinical use has been hampered by vasoconstriction in the systemic and pulmonary beds. Therefore, we aimed to 1 ) determine the possibility of counteracting HBOC-201-induced pressor effects with either adenosine (ADO) or nitroglycerin (NTG); 2 ) assess the potential roles of nitric oxide (NO) scavenging, reactive oxygen species (ROS), and endothelin (ET) in mediating the observed vasoconstriction; and 3 ) compare these effects in resting and exercising swine. Chronically instrumented swine were studied at rest and during exercise after administration of HBOC-201 alone or in combination with ADO. The role of NO was assessed by supplementation with NTG or administration of the eNOS inhibitor N ω -nitro-l-arginine. Alternative vasoactive pathways were investigated via intravenous administration of the ET A /ET B receptor blocker tezosentan or a mixture of ROS scavengers. The systemic and to a lesser extent the pulmonary pressor effects of HBOC-201 could be counteracted by ADO; however, dosage titration was very important to avoid systemic hypotension. Similarly, supplementation of NO with NTG negated the pressor effects but also required titration of the dose. The pressor response to HBOC-201 was reduced after eNOS inhibition and abolished by simultaneous ET A /ET B receptor blockade, while ROS scavenging had no effect. In conclusion, the pressor response to HBOC-201 is mediated by vasoconstriction due to NO scavenging and production of ET. Further research should explore the effect of longer-acting ET receptor blockers to counteract the side effect of hemoglobin-based oxygen carriers. NEW & NOTEWORTHY Hemoglobin-based oxygen carrier (HBOC)-201 can disrupt hemodynamic homeostasis, mimicking some aspects of endothelial dysfunction, resulting in elevated systemic and pulmonary blood

Chronic endothelin A receptor blockade attenuates contribution of sympathetic nervous system to salt hypertension development in adult but not in young Dahl rats

Czech Academy of Sciences Publication Activity Database

Zicha, Josef; Dobešová, Zdenka; Kuneš, Jaroslav; Vaněčková, Ivana

2012-01-01

Roč. 205, č. 1 (2012), s. 124-132 ISSN 1748-1708 R&D Projects: GA MŠk(CZ) 1M0510; GA ČR(CZ) GA305/09/0336; GA AV ČR(CZ) IAA500110902 Institutional research plan: CEZ:AV0Z50110509 Keywords : Endothelin-1 * salt hypertension * Dahl rats Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery Impact factor: 4.382, year: 2012

A chimeric antigen receptor for TRAIL-receptor 1 induces apoptosis in various types of tumor cells.

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Kobayashi, Eiji; Kishi, Hiroyuki; Ozawa, Tatsuhiko; Hamana, Hiroshi; Nakagawa, Hidetoshi; Jin, Aishun; Lin, Zhezhu; Muraguchi, Atsushi

2014-10-31

Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) and its associated receptors (TRAIL-R/TR) are attractive targets for cancer therapy because TRAIL induces apoptosis in tumor cells through TR while having little cytotoxicity on normal cells. Therefore, many agonistic monoclonal antibodies (mAbs) specific for TR have been produced, and these induce apoptosis in multiple tumor cell types. However, some TR-expressing tumor cells are resistant to TR-specific mAb-induced apoptosis. In this study, we constructed a chimeric antigen receptor (CAR) of a TRAIL-receptor 1 (TR1)-specific single chain variable fragment (scFv) antibody (TR1-scFv-CAR) and expressed it on a Jurkat T cell line, the KHYG-1 NK cell line, and human peripheral blood lymphocytes (PBLs). We found that the TR1-scFv-CAR-expressing Jurkat cells killed target cells via TR1-mediated apoptosis, whereas TR1-scFv-CAR-expressing KHYG-1 cells and PBLs killed target cells not only via TR1-mediated apoptosis but also via CAR signal-induced cytolysis, resulting in cytotoxicity on a broader range if target cells than with TR1-scFv-CAR-expressing Jurkat cells. The results suggest that TR1-scFv-CAR could be a new candidate for cancer gene therapy. Copyright © 2014 Elsevier Inc. All rights reserved.

Lactate, endothelin, and central venous oxygen saturation as predictors of mortality in patients with Tetralogy of Fallot

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Poonam Malhotra Kapoor

2016-01-01

Full Text Available Background: Lactate and central venous oxygen saturation (ScVO2 are well known biomarkers for adequacy of tissue oxygenation. Endothelin, an inflammatory marker has been associated with patient′s nutritional status and degree of cyanosis. The aim of this study was to explore the hypothesis that lactate, ScVO2 and endothelin before induction may be predictive of mortality in pediatric cardiac surgery. Methods: We conducted a prospective observational study of 150 pediatric (6 months to 12 years patients who were posted for intracardiac repair for tetralogy of fallot and measured lactate, ScVO2 and endothelin before induction (T1, 20 minutes after protamine administration (T2 and 24 hours after admission to ICU (T3. Results: Preinduction lactate and endothelin levels were found to predict mortality in patients of tetralogy of fallot with an odds ratio of 6.020 (95% CI 2.111-17.168 and 1.292(95% CI 1.091-1.531 respectively. In the ROC curve analysis for lactate at T1, the AUC was 0.713 (95% CI 0.526-0.899 P = 0.019. At the cutoff value of 1.750mmol/lt, the sensitivity and specificity for the prediction of mortality was 63.6% and 65.5%, respectively. For endothelin at T1, the AUC was 0.699 (95% CI 0.516-0.883, P = 0.028 and the cutoff value was ≤2.50 (sensitivity, 63.6%; specificity, 58.3 %. ScVO2 (odds ratio 0.85 at all three time intervals, suggested that improving ScVO2 can lead to 15% reduction in mortality. Conclusions: Lactate, ScVO2 and endothelin all showed association with mortality with lactate having the maximum prediction. Lactate was found to be an independent, reliable and cost-effective measure of prediction of mortality in patients with tetralogy of fallot.

Type I and type II interferons upregulate functional type I interleukin-1 receptor in a human fibroblast cell line TIG-1.

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Takii, T; Niki, N; Yang, D; Kimura, H; Ito, A; Hayashi, H; Onozaki, K

1995-12-01

The regulation of type I interleukin-1 receptor (IL-1R) expression by type I, interferon (IFN)-alpha A/D, and type II IFN, IFN-gamma, in a human fibroblast cell line TIG-1 was investigated. After 2 h stimulation with human IFN-alpha A/D or IFN-gamma, the levels of type I IL-1R mRNA increased. We previously reported that IL-1 upregulates transcription and cell surface molecules of type I IL-1R in TIG-1 cells through induction of prostaglandin (PG) E2 and cAMP accumulation. However, indomethacin was unable to inhibit the effect of IFNs, indicating that IFNs augment IL-1R expression through a pathway distinct from that of IL-1. The augmentation was also observed in other fibroblast cell lines. Nuclear run-on assays and studies of the stability of mRNA suggested that the increase in IL-1R mRNA was a result of the enhanced transcription of IL-1R gene. Binding studies using 125I-IL-1 alpha revealed that the number of cell surface IL-1R increased with no change in binding affinity by treatment with these IFNs. Pretreatment of the cells with IFNs enhanced IL-1-induced IL-6 production, indicating that IFNs upregulate functional IL-1R. IL-1 and IFNs are produced by the same cell types, as well as by the adjacent different cell types, and are concomitantly present in lesions of immune and inflammatory reactions. These results therefore suggest that IFNs exhibit synergistic effects with IL-1 through upregulation of IL-1R. Augmented production of IL-6 may also contribute to the reactions.

Male-female differences in upregulation of vasoconstrictor responses in human cerebral arteries.

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Hilda Ahnstedt

Full Text Available BACKGROUND AND PURPOSE: Male-female differences may significantly impact stroke prevention and treatment in men and women, however underlying mechanisms for sexual dimorphism in stroke are not understood. We previously found in males that cerebral ischemia upregulates contractile receptors in cerebral arteries, which is associated with lower blood flow. The present study investigates if cerebral arteries from men and women differ in cerebrovascular receptor upregulation. EXPERIMENTAL APPROACH: Freshly obtained human cerebral arteries were placed in organ culture, an established model for studying receptor upregulation. 5-hydroxtryptamine type 1B (5-HT1B, angiotensin II type 1 (AT1 and endothelin-1 type A and B (ETA and ETB receptors were evaluated using wire myograph for contractile responses, real-time PCR for mRNA and immunohistochemistry for receptor expression. KEY RESULTS: Vascular sensitivity to angiotensin II and endothelin-1 was markedly lower in cultured cerebral arteries from women as compared to men. ETB receptor-mediated contraction occurred in male but not female arteries. Interestingly, there were similar upregulation in mRNA and expression of 5-HT1B, AT1, and ETB receptors and in local expression of Ang II after organ culture. CONCLUSIONS AND IMPLICATIONS: In spite of receptor upregulation after organ culture in both sexes, cerebral arteries from women were significantly less responsive to vasoconstrictors angiotensin II and endothelin-1 as compared to arteries from men. This suggests receptor coupling and/or signal transduction mechanisms involved in cerebrovascular contractility may be suppressed in females. This is the first study to demonstrate sex differences in the vascular function of human brain arteries.

Favorable Vascular Actions of Angiotensin-(1-7) in Human Obesity.

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Schinzari, Francesca; Tesauro, Manfredi; Veneziani, Augusto; Mores, Nadia; Di Daniele, Nicola; Cardillo, Carmine

2018-01-01

Obese patients have vascular dysfunction related to impaired insulin-stimulated vasodilation and increased endothelin-1-mediated vasoconstriction. In contrast to the harmful vascular actions of angiotensin (Ang) II, the angiotensin-converting enzyme 2 product Ang-(1-7) has shown to exert cardiovascular and metabolic benefits in experimental models through stimulation of the Mas receptor. We, therefore, examined the effects of exogenous Ang-(1-7) on vasodilator tone and endothelin-1-dependent vasoconstriction in obese patients. Intra-arterial infusion of Ang-(1-7) (10 nmol/min) resulted in significant increase in unstimulated forearm flow ( P =0.03), an effect that was not affected by the Mas receptor antagonist A779 (10 nmol/min; P >0.05). In the absence of hyperinsulinemia, however, forearm flow responses to graded doses of acetylcholine and sodium nitroprusside were not different during Ang-(1-7) administration compared with saline (both P >0.05). During infusion of regular insulin (0.15 mU/kg per minute), by contrast, endothelium-dependent vasodilator response to acetylcholine was significantly enhanced by Ang-(1-7) ( P =0.04 versus saline), whereas endothelium-independent response to sodium nitroprusside was not modified ( P =0.91). Finally, Ang-(1-7) decreased the vasodilator response to endothelin A receptor blockade (BQ-123; 10 nmol/min) compared with saline (6±1% versus 93±17%; P obese patients Ang-(1-7) has favorable effects not only to improve insulin-stimulated endothelium-dependent vasodilation but also to blunt endothelin-1-dependent vasoconstrictor tone. These findings provide support for targeting Ang-(1-7) to counteract the hemodynamic abnormalities of human obesity. © 2017 American Heart Association, Inc.

Mood stabilizer treatment increases serotonin type 1A receptor binding in bipolar depression

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Nugent, Allison C; Carlson, Paul J; Bain, Earle E; Eckelman, William; Herscovitch, Peter; Manji, Husseini; Zarate, Carlos A; Drevets, Wayne C

2013-01-01

Abnormal serotonin type 1A (5-HT1A) receptor function and binding have been implicated in the pathophysiology of mood disorders. Preclinical studies have consistently shown that stress decreases the gene expression of 5-HT1A receptors in experimental animals, and that the associated increase in hormone secretion plays a crucial role in mediating this effect. Chronic administration of the mood stabilizers lithium and divalproex (valproate semisodium) reduces glucocorticoid signaling and function in the hippocampus. Lithium has further been shown to enhance 5-HT1A receptor function. To assess whether these effects translate to human subject with bipolar disorder (BD), positron emission tomography (PET) and [18F]trans-4-fluoro-N-(2-[4-(2-methoxyphenyl) piperazino]-ethyl)-N-(2-pyridyl) cyclohexanecarboxamide ([18F]FCWAY) were used to acquire PET images of 5-HT1A receptor binding in 10 subjects with BD, before and after treatment with lithium or divalproex. Mean 5-HT1A binding potential (BPP) significantly increased following mood stabilizer treatment, most prominently in the mesiotemporal cortex (hippocampus plus amygdala). When mood state was also controlled for, treatment was associated with increases in BPP in widespread cortical areas. These preliminary findings are consistent with the hypothesis that these mood stabilizers enhance 5-HT1A receptor expression in BD, which may underscore an important component of these agents' mechanism of action. PMID:23926239

Efecto de la endotelina-1 sobre las arterias tumorales de pacientes con neoplasia colorrectal Effect of endothelin-1 on tumor arteries in patients with colorectal cancer

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E. Ferrero Herrero

2008-06-01

types of arteries, but that sensitivity to this peptide was greater in arteries supplying blood flow to the tumor than in arteries far from the tumor or arteries from patients without cancer. These results suggest that endothelin-1 may regulate blood flow to colorectal tumors by inducing a greater contraction in tumor-supplying arteries than in non-tumor arteries.

The safety of endothelin receptor antagonists in the treatment of pulmonary arterial hypertension: Protocol for a systemic review and network meta-analysis.

Science.gov (United States)

Gu, Zhi-Chun; Zhang, Yi-Jing; Pan, Mang-Mang; Zhang, Chi; Liu, Xiao-Yan; Wei, An-Hua; Su, Ying-Jie

2018-03-01

Pulmonary arterial hypertension (PAH) is a progressive disease and ultimately leads to right heart failure. Endothelin receptor antagonists (ERAs) have been demonstrated to significantly improve prognosis in PAH. However, ERAs-induced side effects can result in poor patient tolerance. Thus, we aim to evaluate current safety evidence of ERAs in PAH. An electronic search will be performed for randomized controlled trials (RCTs) that reported the interested safety data (abnormal liver function, peripheral edema, and anemia) of ERAs in PAH. Risk ratios (RRs) with their confidence intervals (CIs) and the surface under the cumulative ranking curve (SUCRA) will be calculated using a network analysis. This study will provide the safety evidence of ERAs in PAH by combining the results of individual studies based on direct- and network comparison, and to rank ERAs in the evidence network. The results will supplement missing evidence of head-to-head comparisons between different ERAs and guide both clinical decision-making and future research.

A novel mutation of the MITF gene in a family with Waardenburg syndrome type 2: A case report.

Science.gov (United States)

Shi, Yunfang; Li, Xiaozhou; Ju, Duan; Li, Yan; Zhang, Xiuling; Zhang, Ying

2016-04-01

Waardenburg syndrome (WS) is an autosomal dominant disorder with varying degrees of sensorineural hearing loss, and accumulation of pigmentation in hair, skin and iris. There are four types of WS (WS1-4) with differing characteristics. Mutations in six genes [paired box gene 3 ( PAX3 ), microphthalmia-associated transcription factor ( MITF ), endothelin 3 ( END3 ), endothelin receptor type B ( EDNRB ), SRY (sex determining region Y)-box 10 ( SOX10 ) and snail homolog 2 ( SNAI2 )] have been identified to be associated with the various types. This case report describes the investigation of genetic mutations in three patients with WS2 from a single family. Genomic DNA was extracted, and the six WS-related genes were sequenced using next-generation sequencing technology. In addition to mutations in PAX3, EDNRB and SOX10, a novel heterozygous MITF mutation, p.Δ315Arg (c.944_946delGAA) on exon 8 was identified. This is predicted to be a candidate disease-causing mutation that may affect the structure and function of the enzyme.

Interleukin-1 receptor type I gene-deficient mice are less susceptible to Staphylococcus epidermidis biomaterial-associated infection than are wild-type mice

NARCIS (Netherlands)

Boelens, J. J.; van der Poll, T.; Zaat, S. A.; Murk, J. L.; Weening, J. J.; Dankert, J.

2000-01-01

Elevated concentrations of interleukin-1 (IL-1) were found in tissue surrounding biomaterials infected with Staphylococcus epidermidis. To determine the role of IL-1 in biomaterial-associated infection (BAI), IL-1 receptor type I-deficient (IL-1R(-/-)) and wild-type mice received subcutaneous

Phenotypic characterization of Grm1crv4 mice reveals a functional role for the type 1 metabotropic glutamate receptor in bone mineralization.

Science.gov (United States)

Musante, Ilaria; Mattinzoli, Deborah; Otescu, Lavinia Alexandra; Bossi, Simone; Ikehata, Masami; Gentili, Chiara; Cangemi, Giuliana; Gatti, Cinzia; Emionite, Laura; Messa, Piergiorgio; Ravazzolo, Roberto; Rastaldi, Maria Pia; Riccardi, Daniela; Puliti, Aldamaria

2017-01-01

Recent increasing evidence supports a role for neuronal type signaling in bone. Specifically glutamate receptors have been found in cells responsible for bone remodeling, namely the osteoblasts and the osteoclasts. While most studies have focused on ionotropic glutamate receptors, the relevance of the metabotropic glutamate signaling in bone is poorly understood. Specifically type 1 metabotropic glutamate (mGlu1) receptors are expressed in bone, but the effect of its ablation on skeletal development has never been investigated. Here we report that Grm1 crv4/crv4 mice, homozygous for an inactivating mutation of the mGlu1 receptor, and mainly characterized by ataxia and renal dysfunction, exhibit decreased body weight, bone length and bone mineral density compared to wild type (WT) animals. Blood analyses of the affected mice demonstrate the absence of changes in circulating factors, such as vitamin D and PTH, suggesting renal damage is not the main culprit of the skeletal phenotype. Cultures of osteoblasts lacking functional mGlu1 receptors exhibit less homogeneous collagen deposition than WT cells, and present increased expression of osteocalcin, a marker of osteoblast maturation. These data suggest that the skeletal damage is directly linked to the absence of the receptor, which in turn leads to osteoblasts dysfunction and earlier maturation. Accordingly, skeletal histomorphology suggests that Grm1 crv4/crv4 mice exhibit enhanced bone maturation, resulting in premature fusion of the growth plate and shortened long bones, and further slowdown of bone apposition rate compared to the WT animals. In summary, this work reveals novel functions of mGlu1 receptors in the bone and indicates that in osteoblasts mGlu1 receptors are necessary for production of normal bone matrix, longitudinal bone growth, and normal skeletal development. Copyright © 2016 Elsevier Inc. All rights reserved.

Effect of endothelin antagonism on apnea frequency following chronic intermittent hypoxia.

Science.gov (United States)

Donovan, Lucas M; Liu, Yuzhen; Weiss, J Woodrow

2014-04-01

Chronic hypoxia increases the hypoxic ventilatory response (HVR). Augmented HVR contributes to central apneas seen in heart failure and complex sleep apnea. Endothelin receptor (ETR) antagonism decreases carotid body afferent activity following chronic intermittent hypoxia (CIH). We speculated ETR antagonism would reduce HVR and apneas following CIH. HVR and apneas were measured after exposure to CIH and room air sham (SHAM). ETR blocker Ambrisentan was administered via the chow of CIH-exposed animals from days 1 to 12 of CIH (CIH/AMB). A separate crossover group was exposed to CIH and fed normal chow (placebo) days 1-6, and Ambrisentan days 7-12 (CIH/PLA-AMB). SHAM and CIH/PLA animals were fed placebo days 1-12. The CIH/AMB and CIH/PLA-AMB rats had reduced HVR compared to CIH/PLA, similar HVR compared to sham exposed animals, and reduced apnea frequency compared to CIH/PLA animals. The reduced HVR and post-hypoxic apneas resulting from Ambrisentan administration suggests ETR antagonists may have utility in reducing central apneas following CIH. Copyright © 2014 Elsevier B.V. All rights reserved.

Flavonol-rich dark cocoa significantly decreases plasma endothelin-1 and improves cognition in urban children.

Science.gov (United States)

Calderón-Garcidueñas, Lilian; Mora-Tiscareño, Antonieta; Franco-Lira, Maricela; Cross, Janet V; Engle, Randall; Aragón-Flores, Mariana; Gómez-Garza, Gilberto; Jewells, Valerie; Medina-Cortina, Humberto; Solorio, Edelmira; Chao, Chih-Kai; Zhu, Hongtu; Mukherjee, Partha S; Ferreira-Azevedo, Lara; Torres-Jardón, Ricardo; D'Angiulli, Amedeo

2013-01-01

Air pollution exposures are linked to systemic inflammation, cardiovascular and respiratory morbidity and mortality, neuroinflammation and neuropathology in young urbanites. In particular, most Mexico City Metropolitan Area (MCMA) children exhibit subtle cognitive deficits, and neuropathology studies show 40% of them exhibiting frontal tau hyperphosphorylation and 51% amyloid-β diffuse plaques (compared to 0% in low pollution control children). We assessed whether a short cocoa intervention can be effective in decreasing plasma endothelin 1 (ET-1) and/or inflammatory mediators in MCMA children. Thirty gram of dark cocoa with 680 mg of total flavonols were given daily for 10.11 ± 3.4 days (range 9-24 days) to 18 children (10.55 years, SD = 1.45; 11F/7M). Key metabolite ratios in frontal white matter and in hippocampus pre and during cocoa intervention were quantified by magnetic resonance spectroscopy. ET-1 significantly decreased after cocoa treatment (p = 0.0002). Fifteen children (83%) showed a marginally significant individual improvement in one or both of the applied simple short memory tasks. Endothelial dysfunction is a key feature of exposure to particulate matter (PM) and decreased endothelin-1 bioavailability is likely useful for brain function in the context of air pollution. Our findings suggest that cocoa interventions may be critical for early implementation of neuroprotection of highly exposed urban children. Multi-domain nutraceutical interventions could limit the risk for endothelial dysfunction, cerebral hypoperfusion, neuroinflammation, cognitive deficits, structural volumetric detrimental brain effects, and the early development of the neuropathological hallmarks of Alzheimer's and Parkinson's diseases.

Development of occlusive neointimal lesions in distal pulmonary arteries of endothelin B receptor-deficient rats: a new model of severe pulmonary arterial hypertension.

Science.gov (United States)

Ivy, D Dunbar; McMurtry, Ivan F; Colvin, Kelley; Imamura, Masatoshi; Oka, Masahiko; Lee, Dong-Seok; Gebb, Sarah; Jones, Peter Lloyd

2005-06-07

Human pulmonary arterial hypertension (PAH) is characterized by proliferation of vascular smooth muscle and, in its more severe form, by the development of occlusive neointimal lesions. However, few animal models of pulmonary neointimal proliferation exist, thereby limiting a complete understanding of the pathobiology of PAH. Recent studies of the endothelin (ET) system demonstrate that deficiency of the ET(B) receptor predisposes adult rats to acute and chronic hypoxic PAH, yet these animals fail to develop neointimal lesions. Herein, we determined and thereafter showed that exposure of ET(B) receptor-deficient rats to the endothelial toxin monocrotaline (MCT) leads to the development of neointimal lesions that share hallmarks of human PAH. The pulmonary hemodynamic and morphometric effects of 60 mg/kg MCT in control (MCT(+/+)) and ET(B) receptor-deficient (MCT(sl/sl)) rats at 6 weeks of age were assessed. MCT(sl/sl) rats developed more severe PAH, characterized by elevated pulmonary artery pressure, diminished cardiac output, and right ventricular hypertrophy. In MCT(sl/sl) rats, morphometric evaluation revealed the presence of neointimal lesions within small distal pulmonary arteries, increased medial wall thickness, and decreased arterial-to-alveolar ratio. In keeping with this, barium angiography revealed diminished distal pulmonary vasculature of MCT(sl/sl) rat lungs. Cells within neointimal lesions expressed smooth muscle and endothelial cell markers. Moreover, cells within neointimal lesions exhibited increased levels of proliferation and were located in a tissue microenvironment enriched with vascular endothelial growth factor, tenascin-C, and activated matrix metalloproteinase-9, factors already implicated in human PAH. Finally, assessment of steady state mRNA showed that whereas expression of ET(B) receptors was decreased in MCT(sl/sl) rat lungs, ET(A) receptor expression increased. Deficiency of the ET(B) receptor markedly accelerates the progression of

Mutation analysis of peroxisome proliferator-activated receptor-gamma coactivator-1 (PGC-1) and relationships of identified amino acid polymorphisms to Type II diabetes mellitus

DEFF Research Database (Denmark)

Ek, J; Andersen, G; Urhammer, S A

2001-01-01

This study aimed to investigate if variability in the peroxisome proliferator-activated receptor-gamma coactivator-1 (PGC-1) gene is associated with Type II (non-insulin-dependent) diabetes mellitus.......This study aimed to investigate if variability in the peroxisome proliferator-activated receptor-gamma coactivator-1 (PGC-1) gene is associated with Type II (non-insulin-dependent) diabetes mellitus....

Comparison of MEK/ERK pathway inhibitors on the upregulation of vascular G-protein coupled receptors in rat cerebral arteries

DEFF Research Database (Denmark)

Sandhu, Hardip; Ansar, Saema; Edvinsson, Lars

2010-01-01

on translational level and increased respective contractions. The prostanoid TP receptor mediated contraction curve was left-wards shifted by organ culture. Organ culture was associated with elevated pERK1/2 in the vascular smooth muscle cells: the MEK1/2 inhibitor U0126 attenuated the endothelin ET(B) receptor...... mediated contraction at post-translational level or by changing the receptor affinities. The serotonin 5-HT(1B) receptor and prostanoid TP receptor mediated contractions were abolished by U0126. Administration of U0126 6h after start of incubation blocked the receptor upregulation. In conclusion, MEK...

Targeting the ROS-HIF-1-endothelin axis as a therapeutic approach for the treatment of obstructive sleep apnea-related cardiovascular complications.

Science.gov (United States)

Belaidi, Elise; Morand, Jessica; Gras, Emmanuelle; Pépin, Jean-Louis; Godin-Ribuot, Diane

2016-12-01

Obstructive sleep apnea (OSA) is now recognized as an independent and important risk factor for cardiovascular diseases such as hypertension, coronary heart disease, heart failure and stroke. Clinical and experimental data have confirmed that intermittent hypoxia is a major contributor to these deleterious consequences. The repetitive occurrence of hypoxia-reoxygenation sequences generates significant amounts of free radicals, particularly in moderate to severe OSA patients. Moreover, in addition to hypoxia, reactive oxygen species (ROS) are potential inducers of the hypoxia inducible transcription factor-1 (HIF-1) that promotes the transcription of numerous adaptive genes some of which being deleterious for the cardiovascular system, such as the endothelin-1 gene. This review will focus on the involvement of the ROS-HIF-1-endothelin signaling pathway in OSA and intermittent hypoxia and discuss current and potential therapeutic approaches targeting this pathway to treat or prevent cardiovascular disease in moderate to severe OSA patients. Copyright © 2016 Elsevier Inc. All rights reserved.

Enhanced expression of Gqα and PLC-β1 proteins contributes to vascular smooth muscle cell hypertrophy in SHR: role of endogenous angiotensin II and endothelin-1.

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Atef, Mohammed Emehdi; Anand-Srivastava, Madhu B

2014-07-01

Vascular Gqα signaling has been shown to contribute to cardiac hypertrophy. In addition, angiotensin II (ANG II) was shown to induce vascular smooth muscle cell (VSMC) hypertrophy through Gqα signaling; however, the studies on the role of Gqα and PLC-β1 proteins in VSMC hypertrophy in animal model are lacking. The present study was therefore undertaken to examine the role of Gqα/PLC-β1 proteins and the signaling pathways in VSMC hypertrophy using spontaneously hypertensive rats (SHR). VSMC from 16-wk-old SHR and not from 12-wk-old SHR exhibited enhanced levels of Gqα/PLC-β1 proteins compared with age-matched Wistar-Kyoto (WKY) rats as determined by Western blotting. However, protein synthesis as determined by [(3)H]leucine incorporation was significantly enhanced in VSMC from both 12- and 16-wk-old SHR compared with VSMC from age-matched WKY rats. Furthermore, the knockdown of Gqα/PLC-β1 in VSMC from 16-wk-old SHR by antisense and small interfering RNA resulted in attenuation of protein synthesis. In addition, the enhanced expression of Gqα/PLC-β1 proteins, enhanced phosphorylation of ERK1/2, and enhanced protein synthesis in VSMC from SHR were attenuated by the ANG II AT1 and endothelin-1 (ET-1) ETA receptor antagonists losartan and BQ123, respectively, but not by the ETB receptor antagonist BQ788. In addition, PD98059 decreased the enhanced expression of Gqα/PLC-β1 and protein synthesis in VSMC from SHR. These results suggest that the enhanced levels of endogenous ANG II and ET-1 through the activation of AT1 and ETA receptors, respectively, and MAP kinase signaling, enhanced the expression of Gqα/PLC-β1 proteins in VSMC from 16-wk-old SHR and result in VSMC hypertrophy. Copyright © 2014 the American Physiological Society.

The role of the biomarker and the genetic polymorphism of endothelin-1 in pulmonary arterial hypertension among Egyptians

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Emad Ibrahim

2012-10-01

Conclusions: In conclusion, our findings suggest a potential link between endothelin-1 level and specific genotypes in the EDN1 gene and susceptibility for PAH with a worse haemodynamic profile. Further investigations are warranted to understand the molecular basis and to confirm the potential clinical importance of these findings on larger cohorts of patients with PAH. This will impact on the management of PAH of Egyptian patients in the near future.

Analysis of endotoxin and endothelin-1 levels in patients with type 1 hepatorenal syndrome

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GAO Baoxiu

2014-01-01

Full Text Available ObjectiveTo analyze the clinical data, laboratory parameters, infection rate, and serum procalcitonin (PCT and ET-1 levels of patients with cirrhotic ascites and type 1 hepatorenal syndrome (HRS and to investigate the roles of endotoxin and ET-1 in the development of HRS. MethodsBetween January 2009 and October 2012, 56 inpatients with cirrhotic ascites and type 1 HRS (HRS group and 60 inpatients with cirrhotic ascites who had normal renal function (non-HRS group were included in the study. Their general data, causes of liver cirrhosis, infection rates and types, Child-Pugh classification, systemic inflammatory response syndrome (SIRS score, and mean arterial pressure (MAP were recorded; blood samples were collected to evaluate liver and renal function and measure serum electrolyte, PCT, and ET-1 levels. The clinical data and laboratory parameters were compared between the two groups. Categorical data were analyzed by chi-square test; comparison of normally distributed continuous data between the two groups was made by independent-samples t test, and comparison of non-normally distributed continuous data between the two groups was made by Wilcoxon rank sum test. ResultsThe infection rate of HRS group (75.0% was significantly higher than that of non-HRS group (28.4% (χ2=11.91, P＜0.05. The PCT and ET-1 levels and SIRS score of HRS group ［8.72 (3.14, 31.68 ng/L, 13.04±2.82 pg/ml, and 2.1±1.1］ were significantly higher than those of non-HRS group ［0.11 (0.04, 0.45 ng/L, 5.76±1.68 pg/ml, and 0.6±0.6］ (P＜0.05. In addition, the HRS group had significantly higher serum urea, creatine, cystatin C, and K levels than the non-HRS group (P＜0.05, while the HRS group had significantly lower Na and Cl levels than the non-HRS group (P＜0.05. There were no significant differences in ALT and AST levels between the two groups (P＞005. ConclusionEndotoxin causes elevated expression of ET-1, and ET-1 induces renal perfusion deficiency by

Identification of chronic heart failure patients with a high 12-month mortality risk using biomarkers including plasma C-terminal pro-endothelin-1.

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Ewa A Jankowska

Full Text Available OBJECTIVES: We hypothesised that assessment of plasma C-terminal pro-endothelin-1 (CT-proET-1, a stable endothelin-1 precursor fragment, is of prognostic value in patients with chronic heart failure (CHF, beyond other prognosticators, including N-terminal pro-B-type natriuretic peptide (NT-proBNP. METHODS: We examined 491 patients with systolic CHF (age: 63±11 years, 91% men, New York Heart Association [NYHA] class [I/II/III/IV]: 9%/45%/38%/8%, 69% ischemic etiology. Plasma CT-proET-1 was detected using a chemiluminescence immunoassay. RESULTS: Increasing CT-proET-1 was a predictor of increased cardiovascular mortality at 12-months of follow-up (standardized hazard ratio 1.42, 95% confidence interval [CI] 1.04-1.95, p = 0.03 after adjusting for NT-proBNP, left ventricular ejection fraction (LVEF, age, creatinine, NYHA class. In receiver operating characteristic curve analysis, areas under curve for 12-month follow-up were similar for CT-proET-1 and NT-proBNP (p = 0.40. Both NT-proBNP and CT-proET-1 added prognostic value to a base model that included LVEF, age, creatinine, and NYHA class. Adding CT-proET-1 to the base model had stronger prognostic power (p<0.01 than adding NT-proBNP (p<0.01. Adding CT-proET-1 to NT-proBNP in this model yielded further prognostic information (p = 0.02. CONCLUSIONS: Plasma CT-proET-1 constitutes a novel predictor of increased 12-month cardiovascular mortality in patients with CHF. High CT-proET-1 together with high NT-proBNP enable to identify patients with CHF and particularly unfavourable outcomes.

Randomized controlled trial using bosentan to enhance the impact of exercise training in subjects with type 2 diabetes mellitus.

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Schreuder, Tim H A; Duncker, Dirk J; Hopman, Maria T E; Thijssen, Dick H J

2014-11-01

In type 2 diabetes patients, endothelin (ET) receptor blockade may enhance blood flow responses to exercise training. The combination of exercise training and ET receptor blockade may represent a more potent stimulus than training alone to improve vascular function, physical fitness and glucose homeostasis. We assessed the effect of an 8 week exercise training programme combined with either ET blockade or placebo on vasculature, fitness and glucose homeostasis in people with type 2 diabetes. In a double-blind randomized controlled trial, brachial endothelium-dependent and ‑independent dilatation (using flow-mediated dilatation and glyceryl trinitrate, respectively), glucose homeostasis (using Homeostasis Model Assessment for Insulin Resistance (HOMA-IR)) and physical fitness (maximal cycling test) were assessed in 18 men with type 2 diabetes (60 ± 6 years old). Subjects underwent an 8 week exercise training programme, with half of the subjects receiving ET receptor blockade (bosentan) and the other half a placebo, followed by reassessment of the tests above. Exercise training improved physical fitness to a similar extent in both groups, but we did not detect changes in vascular function in either group. This study suggests that there is no adaptation in brachial and femoral artery endothelial function after 8 weeks of training in type 2 diabetes patients. Endothelin receptor blockade combined with exercise training does not additionally alter conduit artery endothelial function or physical fitness in type 2 diabetes. © 2014 The Authors. Experimental Physiology © 2014 The Physiological Society.

Endothelin-1 promotes epithelial–mesenchymal transition in human chondrosarcoma cells by repressing miR-300

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Wu, Min-Huan; Huang, Pei-Han; Hsieh, Mingli; Tsai, Chun-Hao; Chen, Hsien-Te; Tang, Chih-Hsin

2016-01-01

Chondrosarcoma is a malignant tumor of mesenchymal origin predominantly composed of cartilage-producing cells. This type of bone cancer is extremely resistant to radiotherapy and chemotherapy. Surgical resection is the primary treatment, but is often difficult and not always practical for metastatic disease, so more effective treatments are needed. In particular, it would be helpful to identify molecular markers as targets for therapeutic intervention. Endothelin-1 (ET-1), a potent vasoconstrictor, has been shown to enhance chondrosarcoma angiogenesis and metastasis. We report that ET-1 promotes epithelial–mesenchymal transition (EMT) in human chondrosarcoma cells. EMT is a key pathological event in cancer progression, during which epithelial cells lose their junctions and apical-basal polarity and adopt an invasive phenotype. Our study verifies that ET-1 induces the EMT phenotype in chondrosarcoma cells via the AMP-activated protein kinase (AMPK) pathway. In addition, we show that ET-1 increases EMT by repressing miR-300, which plays an important role in EMT-enhanced tumor metastasis. We also show that miR-300 directly targets Twist, which in turn results in a negative regulation of EMT. We found a highly positive correlation between ET-1 and Twist expression levels as well as tumor stage in chondrosarcoma patient specimens. Therefore, ET-1 may represent a potential novel molecular therapeutic target in chondrosarcoma metastasis. PMID:27602960

Endothelin-1 promotes epithelial-mesenchymal transition in human chondrosarcoma cells by repressing miR-300.

Science.gov (United States)

Wu, Min-Huan; Huang, Pei-Han; Hsieh, Mingli; Tsai, Chun-Hao; Chen, Hsien-Te; Tang, Chih-Hsin

2016-10-25

Chondrosarcoma is a malignant tumor of mesenchymal origin predominantly composed of cartilage-producing cells. This type of bone cancer is extremely resistant to radiotherapy and chemotherapy. Surgical resection is the primary treatment, but is often difficult and not always practical for metastatic disease, so more effective treatments are needed. In particular, it would be helpful to identify molecular markers as targets for therapeutic intervention. Endothelin-1 (ET-1), a potent vasoconstrictor, has been shown to enhance chondrosarcoma angiogenesis and metastasis. We report that ET-1 promotes epithelial-mesenchymal transition (EMT) in human chondrosarcoma cells. EMT is a key pathological event in cancer progression, during which epithelial cells lose their junctions and apical-basal polarity and adopt an invasive phenotype. Our study verifies that ET-1 induces the EMT phenotype in chondrosarcoma cells via the AMP-activated protein kinase (AMPK) pathway. In addition, we show that ET-1 increases EMT by repressing miR-300, which plays an important role in EMT-enhanced tumor metastasis. We also show that miR-300 directly targets Twist, which in turn results in a negative regulation of EMT. We found a highly positive correlation between ET-1 and Twist expression levels as well as tumor stage in chondrosarcoma patient specimens. Therefore, ET-1 may represent a potential novel molecular therapeutic target in chondrosarcoma metastasis.

Plasmatic endothelin-1 levels in hyperthyroid patients before and after antithyroid therapy.

Science.gov (United States)

Cesareo, R; Tarabuso, A; Di Benedetto, M; Lacerna, F; Reda, G

2000-03-01

The Endothelin-1 (ET-1) is a powerful vasoconstrictor peptide produced by endothelial cells in many vascular diseases probably as a response to vessel damage. In hyperthyroidism as in other endocrinological diseases elevated ET-1 plasma levels have been found. The effect of antithyroid therapy on ET-1 plasmatic levels was evaluated by measuring ET-1 plasma levels before and 2 and 6 months after treatment with methimazole in 14 patients affected by hyperthyroidism. The hyperthyroid patients had significantly higher ET-1 levels than the controls (18.85 +/- 5.7 vs 10.9 +/- 2.1 pg/ml), while after treatment no difference was found. The ET-1 plasma levels of hyperthyroid patients correlated closely with the raised thyroid metabolic activity independently of its cause. It is possible that the increased ET-1 levels in hyperthyroid patients are the expression of blood vessel damage caused by high thyroid hormone levels. Moreover the results of this study could suggest that, in future, ET-1 plasmatic levels might be considered as a functional thyroid index in hyperthyroid diseases.

Type 1 IGF receptor translocates to the nucleus of human tumor cells

OpenAIRE

Aleksic, Tamara; Chitnis, Meenali M.; Perestenko, Olga V.; Gao, Shan; Thomas, Peter H.; Turner, Gareth D.; Protheroe, Andrew S.; Howarth, Mark; Macaulay, Valentine M.

2010-01-01

The type 1 insulin-like growth factor receptor (IGF-1R) is a transmembrane glycoprotein comprising two extracellular α subunits and two β subunits with tyrosine kinase activity. The IGF-1R is frequently upregulated in cancers, and signals from the cell surface to promote proliferation and cell survival. Recent attention has focused on the IGF-1R as a target for cancer treatment. Here we report that the nuclei of human tumor cells contain IGF-1R, detectable using multiple antibodies to α- and ...

Short-acting glucagon-like peptide-1 receptor agonists as add-on to insulin therapy in type 1 diabetes

DEFF Research Database (Denmark)

Albèr, Anders; Brønden, Andreas; Knop, Filip K

2017-01-01

emptying in patients with type 1 diabetes, which could translate into effective lowering of postprandial glucose excursions; however, these observations regarding short-acting GLP-1RAs are all derived from small open-label trials and should thus be interpreted with caution. In the present paper we review......A large proportion of patients with type 1 diabetes do not reach their glycaemic target of glycated hemoglobin (HbA1c) type 1 diabetes are overweight and obese. Treatment of type 1 diabetes is based on insulin therapy......, which is associated with well-described and unfortunate adverse effects such as hypoglycaemia and increased body weight. Glucagon-like peptide-1 (GLP-1) receptor agonists (RAs) are the focus of increasing interest as a possible adjunctive treatment to insulin in type 1 diabetes because...

Lipid-soluble smoke particles upregulate vascular smooth muscle ETB receptors via activation of mitogen-activating protein kinases and NF-kappaB pathways

DEFF Research Database (Denmark)

Xu, C.B.; Zheng, J.P.; Zhang, W.

2008-01-01

Cigarette smoke is a strong risk factor for cardiovascular disease. However, the underlying molecular mechanisms that lead to cigarette smoke-associated cardiovascular disease remain elusive. With functional and molecular methods, we demonstrate for the first time that lipid-soluble cigarette smoke...... particles (dimethylsulfoxide-soluble cigarette smoke particles; DSP) increased the expression of endothelin type B (ET(B)) receptors in arterial smooth muscle cells. The increased ET(B) receptors in arterial smooth muscle cells was documented as enhanced contractility (sensitive myograph technique...

Membrane Estrogen Receptor-α Interacts with Metabotropic Glutamate Receptor Type 1a to Mobilize Intracellular Calcium in Hypothalamic Astrocytes

Science.gov (United States)

Kuo, John; Hariri, Omid R.; Bondar, Galyna; Ogi, Julie; Micevych, Paul

2009-01-01

Estradiol, acting on a membrane-associated estrogen receptor-α (mERα), induces an increase in free cytoplasmic calcium concentration ([Ca2+]i) needed for progesterone synthesis in hypothalamic astrocytes. To determine whether rapid estradiol signaling involves an interaction of mERα with metabotropic glutamate receptor type 1a (mGluR1a), changes in [Ca2+]i were monitored with the calcium indicator, Fluo-4 AM, in primary cultures of female postpubertal hypothalamic astrocytes. 17β-Estradiol over a range of 1 nm to 100 nm induced a maximal increase in [Ca2+]i flux measured as a change in relative fluorescence [ΔF Ca2+ = 615 ± 36 to 641 ± 47 relative fluorescent units (RFU)], whereas 0.1 nm of estradiol stimulated a moderate [Ca2+]i increase (275 ± 16 RFU). The rapid estradiol-induced [Ca2+]i flux was blocked with 1 μm of the estrogen receptor antagonist ICI 182,780 (635 ± 24 vs. 102 ± 11 RFU, P estradiol-induced membrane signaling in astrocytes. PMID:18948402

CRF1 receptor-deficiency increases cocaine reward.

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Contarino, Angelo; Kitchener, Pierre; Vallée, Monique; Papaleo, Francesco; Piazza, Pier-Vincenzo

2017-05-01

Stimulant drugs produce reward but also activate stress-responsive systems. The corticotropin-releasing factor (CRF) and the related hypothalamus-pituitary-adrenal (HPA) axis stress-responsive systems are activated by stimulant drugs. However, their role in stimulant drug-induced reward remains poorly understood. Herein, we report that CRF 1 receptor-deficient (CRF 1 -/-), but not wild-type, mice show conditioned place preference (CPP) responses to a relatively low cocaine dose (5 mg/kg, i.p.). Conversely, wild-type, but not CRF 1 -/-, mice display CPP responses to a relatively high cocaine dose (20 mg/kg, i.p.), indicating that CRF 1 receptor-deficiency alters the rewarding effects of cocaine. Acute pharmacological antagonism of the CRF 1 receptor by antalarmin also eliminates cocaine reward. Nevertheless, CRF 1 -/- mice display higher stereotypy responses to cocaine than wild-type mice. Despite the very low plasma corticosterone concentration, CRF 1 -/- mice show higher nuclear glucocorticoid receptor (GR) levels in the brain region of the hippocampus than wild-type mice. Full rescue of wild-type-like corticosterone and GR circadian rhythm and level in CRF 1 -/- mice by exogenous corticosterone does not affect CRF 1 receptor-dependent cocaine reward but induces stereotypy responses to cocaine. These results indicate a critical role for the CRF 1 receptor in cocaine reward, independently of the closely related HPA axis activity. Copyright © 2017 Elsevier Ltd. All rights reserved.

The Matrix Metalloproteases and Endothelin-1 in Infection-Associated Preterm Birth

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Nicole S. Olgun

2010-01-01

Full Text Available Preterm birth (PTB is clinically defined as any delivery which occurs before the completion of 37 weeks of gestation, and is currently the most important problem in obstetrics. In the United States, PTB accounts for 12-13% of all live births, and, with the exception of fetuses suffering from anomalies, is the primary cause of perinatal mortality. While the risk factors for PTB are numerous, the single most common cause is intrauterine infection. As there is currently no FDA-approved therapy for infection-associated PTB, understanding the pathogenesis of preterm labor (PTL and delivery should be given high priority. The matrix metalloproteinases (MMPs are a family of enzymes that have been implicated in normal parturition as well as infection-triggered rupture of membranes and preterm birth. Several lines of evidence also suggest a role for endothelin-1 (ET-1 in infection-associated preterm delivery. This paper focuses on the evidence that the MMPs and ET-1 act in the same molecular pathway in preterm birth.

Type 1 diabetes promotes disruption of advanced atherosclerotic lesions in LDL receptor-deficient mice

OpenAIRE

Johansson, Fredrik; Kramer, Farah; Barnhart, Shelley; Kanter, Jenny E.; Vaisar, Tomas; Merrill, Rachel D.; Geng, Linda; Oka, Kazuhiro; Chan, Lawrence; Chait, Alan; Heinecke, Jay W.; Bornfeldt, Karin E.

2008-01-01

Cardiovascular disease, largely because of disruption of atherosclerotic lesions, accounts for the majority of deaths in people with type 1 diabetes. Recent mouse models have provided insights into the accelerated atherosclerotic lesion initiation in diabetes, but it is unknown whether diabetes directly worsens more clinically relevant advanced lesions. We therefore used an LDL receptor-deficient mouse model, in which type 1 diabetes can be induced at will, to investigate the effects of diabe...

Flavonol-rich dark cocoa significantly decreases plasma endothelin-1 and improves cognitive responses in urban children.

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Lilian eCalderon-Garciduenas

2013-08-01

Full Text Available Air pollution exposures are linked to systemic inflammation, cardiovascular and respiratory morbidity and mortality, neuroinflammation and neuropathology in young urbanites. In particular, most Mexico City Metropolitan Area (MCMA children exhibit subtle cognitive deficits, and neuropathology studies show 40% of them exhibiting frontal tau hyperphosphorylation and 51% amyloid-β diffuse plaques (compared to 0% in low pollution control children. We assessed whether a short cocoa intervention can be effective in decreasing plasma endothelin 1 (ET-1 and/or inflammatory mediators in MCMA children. Thirty g of dark cocoa with 680 mg of total flavonols were given daily for 10.11± 3.4 days (range 9 to 24 days to 18 children (10.55yrs, SD =1.45; 11F/7M. Key metabolite ratios in frontal white matter and in hippocampus pre and during cocoa intervention were quantified by magnetic resonance spectroscopy. ET-1 significantly decreased after cocoa treatment (p=0.0002. Fifteen children (83% showed a marginally significant individual improvement in one or both of the applied simple short memory tasks. Endothelial dysfunction is a key feature of exposure to particulate matter and decreased endothelin-1 bioavailability is likely useful for brain function in the context of air pollution. Our findings suggest that cocoa interventions may be critical for early implementation of neuroprotection of highly exposed urban children. Multi-domain nutraceutical interventions could limit the risk for endothelial dysfunction, cerebral hypoperfusion, neuroinflammation, cognitive deficits, structural volumetric detrimental brain effects, and the early development of the neuropathological hallmarks of Alzheimer’s and Parkinson’s diseases.

Exercise reduces adipose tissue via cannabinoid receptor type 1 which is regulated by peroxisome proliferator-activated receptor-δ

International Nuclear Information System (INIS)

Yan Zhencheng; Liu Daoyan; Zhang Lili; Shen Chenyi; Ma Qunli; Cao Tingbing; Wang Lijuan; Nie Hai; Zidek, Walter; Tepel, Martin; Zhu Zhiming

2007-01-01

Obesity is one major cardiovascular risk factor. We tested effects of endurance exercise on cannabinoid receptor type 1 (CB1) and peroxisome proliferator-activated receptor-δ (PPAR-δ)-dependent pathways in adipose tissue. Male Wistar rats were randomly assigned to standard laboratory chow or a high-fat diet without and with regular endurance exercise. Exercise in rats on high-fat diet significantly reduced visceral fat mass, blood pressure, and adipocyte size (each p < 0.05). Adipocyte hypertrophy induced by high-fat diet was accompanied by increased CB1 expression in adipose tissue, whereas exercise significantly reduced CB1 expression (each p < 0.05). CB1 receptor expression and adipocyte differentiation were directly regulated by PPAR-δ. Adipocyte hypertrophy induced by high-fat diet was accompanied by reduced PPAR-δ. Furthermore, selective silencing of PPAR-δ by RNA interference in 3T3-L1-preadipocyte cells significantly increased CB1 expression from 1.00 ± 0.06 (n = 3) to 1.91 ± 0.06 (n = 3; p < 0.01) and increased adipocyte differentiation, whereas adenovirus-mediated overexpression of PPAR-δ significantly reduced CB1 expression to 0.39 ± 0.03 (n = 3; p < 0.01) and reduced adipocyte differentiation. In the presence of the CB1 antagonist rimonabant adipocyte differentiation in stimulated 3T3 L1 preadipocyte cells was significantly reduced. The study indicates that high-fat diet-induced hypertrophy of adipocytes is associated with increased CB1 receptor expression which is directly regulated by PPAR-δ. Both CB1 and PPAR-δ are intimately involved in therapeutic interventions against a most important cardiovascular risk factor

Evolution of the C-Type Lectin-Like Receptor Genes of the DECTIN-1 Cluster in the NK Gene Complex

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Susanne Sattler

2012-01-01

Full Text Available Pattern recognition receptors are crucial in initiating and shaping innate and adaptive immune responses and often belong to families of structurally and evolutionarily related proteins. The human C-type lectin-like receptors encoded in the DECTIN-1 cluster within the NK gene complex contain prominent receptors with pattern recognition function, such as DECTIN-1 and LOX-1. All members of this cluster share significant homology and are considered to have arisen from subsequent gene duplications. Recent developments in sequencing and the availability of comprehensive sequence data comprising many species showed that the receptors of the DECTIN-1 cluster are not only homologous to each other but also highly conserved between species. Even in Caenorhabditis elegans, genes displaying homology to the mammalian C-type lectin-like receptors have been detected. In this paper, we conduct a comprehensive phylogenetic survey and give an up-to-date overview of the currently available data on the evolutionary emergence of the DECTIN-1 cluster genes.

Effects of muscarinic receptor antagonists on cocaine discrimination in wild-type mice and in muscarinic receptor M1, M2, and M4 receptor knockout mice.

Science.gov (United States)

Joseph, Lauren; Thomsen, Morgane

2017-06-30

Muscarinic M 1 /M 4 receptor stimulation can reduce abuse-related effects of cocaine and may represent avenues for treating cocaine addiction. Muscarinic antagonists can mimic and enhance effects of cocaine, including discriminative stimulus (S D ) effects, but the receptor subtypes mediating those effects are not known. A better understanding of the complex cocaine/muscarinic interactions is needed to evaluate and develop potential muscarinic-based medications. Here, knockout mice lacking M 1 , M 2 , or M 4 receptors (M 1 -/- , M 2 -/- , M 4 -/- ), as well as control wild-type mice and outbred Swiss-Webster mice, were trained to discriminate 10mg/kg cocaine from saline. Muscarinic receptor antagonists with no subtype selectivity (scopolamine), or preferential affinity at the M 1 , M 2 , or M 4 subtype (telenzepine, trihexyphenidyl; methoctramine, AQ-RA 741; tropicamide) were tested alone and in combination with cocaine. In intact animals, antagonists with high affinity at M 1 /M 4 receptors partially substituted for cocaine and increased the S D effect of cocaine, while M 2 -preferring antagonists did not substitute, and reduced the S D effect of cocaine. The cocaine-like effects of scopolamine were absent in M 1 -/- mice. The cocaine S D attenuating effects of methoctramine were absent in M 2 -/- mice and almost absent in M 1 -/- mice. The findings indicate that the cocaine-like S D effects of muscarinic antagonists are primarily mediated through M 1 receptors, with a minor contribution of M 4 receptors. The data also support our previous findings that stimulation of M 1 receptors and M 4 receptors can each attenuate the S D effect of cocaine, and show that this can also be achieved by blocking M 2 autoreceptors, likely via increased acetylcholine release. Copyright © 2017 Elsevier B.V. All rights reserved.

Role of endothelin-converting enzyme, chymase and neutral endopeptidase in the processing of big ET-1, ET-1(1-21) and ET-1(1-31) in the trachea of allergic mice.

Science.gov (United States)

De Campo, Benjamin A; Goldie, Roy G; Jeng, Arco Y; Henry, Peter J

2002-08-01

The present study examined the roles of endothelin-converting enzyme (ECE), neutral endopeptidase (NEP) and mast cell chymase as processors of the endothelin (ET) analogues ET-1(1-21), ET-1(1-31) and big ET-1 in the trachea of allergic mice. Male CBA/CaH mice were sensitized with ovalbumin (10 microg) delivered intraperitoneal on days 1 and 14, and exposed to aerosolized ovalbumin on days 14, 25, 26 and 27 (OVA mice). Mice were killed and the trachea excised for histological analysis and contraction studies on day 28. Tracheae from OVA mice had 40% more mast cells than vehicle-sensitized mice (sham mice). Ovalbumin (10 microg/ml) induced transient contractions (15+/-3% of the C(max)) in tracheae from OVA mice. The ECE inhibitor CGS35066 (10 microM) inhibited contractions induced by big ET-1 (4.8-fold rightward shift of dose-response curve; Peffect on contractions induced by any of the ET analogues used. The NEP inhibitor CGS24592 (10 microM) inhibited contractions induced by ET-1(1-31) (6.2-fold rightward shift; Pbig ET-1. These data suggest that big ET-1 is processed predominantly by a CGS35066-sensitive ECE within allergic airways rather than by mast cell-derived proteases such as chymase. If endogenous ET-1(1-31) is formed within allergic airways, it is likely to undergo further conversion by NEP to more active products.

Upregulation of Cannabinoid Type 1 Receptors in Dopamine D2 Receptor Knockout Mice Is Reversed by Chronic Forced Ethanol Consumption

Energy Technology Data Exchange (ETDEWEB)

Thanos, P.K.; Wang, G.; Thanos, P.K.; Gopez, V.; Delis, F.; Michaelides, M.; Grand, D.K.; Wang, G.-J.; Kunos, G.; Volkow, N.D.

2011-01-01

The anatomical proximity of the cannabinoid type 1 (CNR1/CB1R) and the dopamine D2 receptors (DRD2), their ability to form CB1R-DRD2 heteromers, their opposing roles in locomotion, and their involvement in ethanol's reinforcing and addictive properties prompted us to study the levels and distribution of CB1R after chronic ethanol intake, in the presence and absence of DRD2. We monitored the drinking patterns and locomotor activity of Drd2+/+ and Drd2-/- mice consuming either water or a 20% (v/v) ethanol solution (forced ethanol intake) for 6 months and used the selective CB1 receptor antagonist [{sup 3}H]SR141716A to quantify CB1R levels in different brain regions with in vitro receptor autoradiography. We found that the lack of DRD2 leads to a marked upregulation (approximately 2-fold increase) of CB1R in the cerebral cortex, the caudate-putamen, and the nucleus accumbens, which was reversed by chronic ethanol intake. The results suggest that DRD2-mediated dopaminergic neurotransmission and chronic ethanol intake exert an inhibitory effect on cannabinoid receptor expression in cortical and striatal regions implicated in the reinforcing and addictive properties of ethanol.

Endothelin A receptor blocker atrasentan lowers blood pressure by the reduction of nifedipine-sensitive calcium influx in Ren-2 transgenic rats fed a high-salt diet

Czech Academy of Sciences Publication Activity Database

Vaněčková, Ivana; Dobešová, Zdenka; Kuneš, Jaroslav; Vernerová, Z.; Zicha, Josef

2015-01-01

Roč. 33, č. 1 (2015), s. 161-169 ISSN 0263-6352 R&D Projects: GA ČR(CZ) GAP304/12/0259 Institutional support: RVO:67985823 Keywords : endothelin * high-salt intake * hypertension * Ren-2 Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery Impact factor: 5.062, year: 2015

Effect of breed on plasma endothelin-1 concentration, plasma renin activity, and serum cortisol concentration in healthy dogs

DEFF Research Database (Denmark)

Höglund, K.; Lequarré, A.-S.; Ljungvall, I.

2016-01-01

BACKGROUND: There are breed differences in several blood variables in healthy dogs. OBJECTIVE: Investigate breed variation in plasma endothelin-1 (ET-1) concentration, plasma renin activity, and serum cortisol concentration. ANIMALS: Five-hundred and thirty-one healthy dogs of 9 breeds examined...... at 5 centers (2-4 breeds/center). METHODS: Prospective observational study. Circulating concentrations of ET-1 and cortisol, and renin activity, were measured using commercially available assays. Absence of organ-related or systemic disease was ensured by thorough clinical investigations, including...

Comparative effects of chlorpyrifos in wild type and cannabinoid Cb1 receptor knockout mice

Energy Technology Data Exchange (ETDEWEB)

Baireddy, Praveena; Liu, Jing; Hinsdale, Myron; Pope, Carey, E-mail: carey.pope@okstate.edu

2011-11-15

Endocannabinoids (eCBs) modulate neurotransmission by inhibiting the release of a variety of neurotransmitters. The cannabinoid receptor agonist WIN 55.212-2 (WIN) can modulate organophosphorus (OP) anticholinesterase toxicity in rats, presumably by inhibiting acetylcholine (ACh) release. Some OP anticholinesterases also inhibit eCB-degrading enzymes. We studied the effects of the OP insecticide chlorpyrifos (CPF) on cholinergic signs of toxicity, cholinesterase activity and ACh release in tissues from wild type (+/+) and cannabinoid CB1 receptor knockout (-/-) mice. Mice of both genotypes (n = 5-6/treatment group) were challenged with CPF (300 mg/kg, 2 ml/kg in peanut oil, sc) and evaluated for functional and neurochemical changes. Both genotypes exhibited similar cholinergic signs and cholinesterase inhibition (82-95% at 48 h after dosing) in cortex, cerebellum and heart. WIN reduced depolarization-induced ACh release in vitro in hippocampal slices from wild type mice, but had no effect in hippocampal slices from knockouts or in striatal slices from either genotype. Chlorpyrifos oxon (CPO, 100 {mu}M) reduced release in hippocampal slices from both genotypes in vitro, but with a greater reduction in tissues from wild types (21% vs 12%). CPO had no significant in vitro effect on ACh release in striatum. CPF reduced ACh release in hippocampus from both genotypes ex vivo, but reduction was again significantly greater in tissues from wild types (52% vs 36%). In striatum, CPF led to a similar reduction (20-23%) in tissues from both genotypes. Thus, while CB1 deletion in mice had little influence on the expression of acute toxicity following CPF, CPF- or CPO-induced changes in ACh release appeared sensitive to modulation by CB1-mediated eCB signaling in a brain-regional manner. -- Highlights: Black-Right-Pointing-Pointer C57Bl/6 mice showed dose-related cholinergic toxicity following subcutaneous chlorpyrifos exposure. Black-Right-Pointing-Pointer Wild type and

Comparative effects of chlorpyrifos in wild type and cannabinoid Cb1 receptor knockout mice

International Nuclear Information System (INIS)

Baireddy, Praveena; Liu, Jing; Hinsdale, Myron; Pope, Carey

2011-01-01

Endocannabinoids (eCBs) modulate neurotransmission by inhibiting the release of a variety of neurotransmitters. The cannabinoid receptor agonist WIN 55.212-2 (WIN) can modulate organophosphorus (OP) anticholinesterase toxicity in rats, presumably by inhibiting acetylcholine (ACh) release. Some OP anticholinesterases also inhibit eCB-degrading enzymes. We studied the effects of the OP insecticide chlorpyrifos (CPF) on cholinergic signs of toxicity, cholinesterase activity and ACh release in tissues from wild type (+/+) and cannabinoid CB1 receptor knockout (−/−) mice. Mice of both genotypes (n = 5–6/treatment group) were challenged with CPF (300 mg/kg, 2 ml/kg in peanut oil, sc) and evaluated for functional and neurochemical changes. Both genotypes exhibited similar cholinergic signs and cholinesterase inhibition (82–95% at 48 h after dosing) in cortex, cerebellum and heart. WIN reduced depolarization-induced ACh release in vitro in hippocampal slices from wild type mice, but had no effect in hippocampal slices from knockouts or in striatal slices from either genotype. Chlorpyrifos oxon (CPO, 100 μM) reduced release in hippocampal slices from both genotypes in vitro, but with a greater reduction in tissues from wild types (21% vs 12%). CPO had no significant in vitro effect on ACh release in striatum. CPF reduced ACh release in hippocampus from both genotypes ex vivo, but reduction was again significantly greater in tissues from wild types (52% vs 36%). In striatum, CPF led to a similar reduction (20–23%) in tissues from both genotypes. Thus, while CB1 deletion in mice had little influence on the expression of acute toxicity following CPF, CPF- or CPO-induced changes in ACh release appeared sensitive to modulation by CB1-mediated eCB signaling in a brain-regional manner. -- Highlights: ► C57Bl/6 mice showed dose-related cholinergic toxicity following subcutaneous chlorpyrifos exposure. ► Wild type and cannabinoid CB1 receptor knockout littermates

L-arginine does not prevent the renal effects of endothelin in humans

NARCIS (Netherlands)

Bijlsma, J. A.; Rabelink, A. J.; Kaasjager, K. A.; Koomans, H. A.

1995-01-01

The infusion of endothelin to obtain plasma levels as present in sodium-retaining conditions such as heart failure and hepatorenal syndrome has been shown to cause sodium retention and renal vasoconstriction. Whether these renal effects of endothelin could be modulated by the stimulation of nitric

The inhibitory effect of an extract of Sanguisorba officinalis L. on ultraviolet B-induced pigmentation via the suppression of endothelin-converting enzyme-1{alpha}

Energy Technology Data Exchange (ETDEWEB)

Hachiya, Akira; Kobayashi, Akemi; Ohuchi, Atsushi; Kitahara, Takashi; Takema, Yoshinori [Kao Biological Science Lab., Ichikai, Tochigi (Japan)

2001-06-01

Endothelin-1 (ET-1) has been reported to be expressed in human epidermis at both the gene and protein levels. ET-1 plays a pivotal role in ultraviolet B (UVB)-induced pigmentation due to its accentuated secretion after UVB irradiation and its function as a mitogen and as a melanogen for human melanocytes. We have recently found that endothelin-converting enzyme (ECE)-1{alpha} plays a constitutive role in the secretion of ET-1 by human keratinocytes and that an extract of Sanguisorba officinalis L. inhibits ECE activity in human endothelial cells, which predominantly express ECE-1{alpha}. In this report, to clarify the potential use of this botanical extract as a whitening agent, we examined whether this extract inhibits UVB-induced pigmentation in vivo. When this extract was applied to human keratinocytes after UVB irradiation, secretion of ET-1 by those cells was reduced, and this was accompanied by a concomitant increase in the secretion of inactive precursor Big endothelin-1. When hairless mice were exposed to UVB light and were treated with the extract, it suppressed the induction of ET-1 in the UVB-irradiated epidermis. In the course of UVB-induced pigmentation of brownish guinea pig skin, this extract significantly diminished pigmentation in UVB-exposed areas. These findings indicate that ECE-1{alpha} in keratinocytes plays a pivotal role in the induction of pigmentation following UVB irradiation and that an extract of S. officinalis, which inhibits ET-1 production in human keratinocytes, is a good ingredient for a whitening agent. (author)

The inhibitory effect of an extract of Sanguisorba officinalis L. on ultraviolet B-induced pigmentation via the suppression of endothelin-converting enzyme-1α

International Nuclear Information System (INIS)

Hachiya, Akira; Kobayashi, Akemi; Ohuchi, Atsushi; Kitahara, Takashi; Takema, Yoshinori

2001-01-01

Endothelin-1 (ET-1) has been reported to be expressed in human epidermis at both the gene and protein levels. ET-1 plays a pivotal role in ultraviolet B (UVB)-induced pigmentation due to its accentuated secretion after UVB irradiation and its function as a mitogen and as a melanogen for human melanocytes. We have recently found that endothelin-converting enzyme (ECE)-1α plays a constitutive role in the secretion of ET-1 by human keratinocytes and that an extract of Sanguisorba officinalis L. inhibits ECE activity in human endothelial cells, which predominantly express ECE-1α. In this report, to clarify the potential use of this botanical extract as a whitening agent, we examined whether this extract inhibits UVB-induced pigmentation in vivo. When this extract was applied to human keratinocytes after UVB irradiation, secretion of ET-1 by those cells was reduced, and this was accompanied by a concomitant increase in the secretion of inactive precursor Big endothelin-1. When hairless mice were exposed to UVB light and were treated with the extract, it suppressed the induction of ET-1 in the UVB-irradiated epidermis. In the course of UVB-induced pigmentation of brownish guinea pig skin, this extract significantly diminished pigmentation in UVB-exposed areas. These findings indicate that ECE-1α in keratinocytes plays a pivotal role in the induction of pigmentation following UVB irradiation and that an extract of S. officinalis, which inhibits ET-1 production in human keratinocytes, is a good ingredient for a whitening agent. (author)

Spatial distribution of cannabinoid receptor type 1 (CB1 in normal canine central and peripheral nervous system.

Directory of Open Access Journals (Sweden)

Jessica Freundt-Revilla

Full Text Available The endocannabinoid system is a regulatory pathway consisting of two main types of cannabinoid receptors (CB1 and CB2 and their endogenous ligands, the endocannabinoids. The CB1 receptor is highly expressed in the central and peripheral nervous systems (PNS in mammalians and is involved in neuromodulatory functions. Since endocannabinoids were shown to be elevated in cerebrospinal fluid of epileptic dogs, knowledge about the species specific CB receptor expression in the nervous system is required. Therefore, we assessed the spatial distribution of CB1 receptors in the normal canine CNS and PNS. Immunohistochemistry of several regions of the brain, spinal cord and peripheral nerves from a healthy four-week-old puppy, three six-month-old dogs, and one ten-year-old dog revealed strong dot-like immunoreactivity in the neuropil of the cerebral cortex, Cornu Ammonis (CA and dentate gyrus of the hippocampus, midbrain, cerebellum, medulla oblongata and grey matter of the spinal cord. Dense CB1 expression was found in fibres of the globus pallidus and substantia nigra surrounding immunonegative neurons. Astrocytes were constantly positive in all examined regions. CB1 labelled neurons and satellite cells of the dorsal root ganglia, and myelinating Schwann cells in the PNS. These results demonstrate for the first time the spatial distribution of CB1 receptors in the healthy canine CNS and PNS. These results can be used as a basis for further studies aiming to elucidate the physiological consequences of this particular anatomical and cellular distribution.

Pharmacological characterization of homobaclofen on wild type and mutant GABA(B)1b receptors coexpressed with the GABA(B)2 receptor

DEFF Research Database (Denmark)

Jensen, Anders A.; Madsen, Bo E.; Krogsgaard-Larsen, P

2001-01-01

homogenate and in an assay of electrically induced contractions of guinea pig ileum. The results from the two tissues did, however, not correlate very well, and in order to further investigate these discrepancies, we have pharmacologically characterized these enantiomers on recombinant wild type and mutant...... rat GABA(B)1b receptors coexpressed with rat GABA(B)2 receptors. The results from this study correlate nicely with the binding data from rat brain. (R)-Homobaclofen was shown to act like (R)-baclofen albeit with 20-fold less potency, and (S)-homobaclofen was inactive on the receptor. The discrepancies...

A chimeric receptor of the insulin-like growth factor receptor type 1 (IGFR1) and a single chain antibody specific to myelin oligodendrocyte glycoprotein activates the IGF1R signalling cascade in CG4 oligodendrocyte progenitors

NARCIS (Netherlands)

Annenkov, A.; Rigby, A.; Amor, S.; Zhou, D.M.; Yousaf, N.; Hemmer, B.; Chernajovsky, Y.

2011-01-01

In order to generate neural stem cells with increased ability to survive after transplantation in brain parenchyma we developed a chimeric receptor (ChR) that binds to myelin oligodendrocyte glycoprotein (MOG) via its ectodomain and activates the insulin-like growth factor receptor type 1 (IGF1R)

Human endothelin subtype A receptor enhancement during tissue culture via de novo transcription

DEFF Research Database (Denmark)

Hansen-Schwartz, Jacob; Nordström, Carl-Henrik; Edvinsson, Lars

2002-01-01

OBJECTIVE: Endothelin (ET) has, since its discovery, increasingly been considered a key player in the pathophysiological processes of cerebral vasospasm in the course of subarachnoid hemorrhage, although it remains unclear how ET is involved. We present data that indicate an inherent capacity...... of human cerebral arteries to change their sensitivity to ET. METHODS: Human cerebral arteries were obtained from patients undergoing intracranial tumor surgery. The vessels were divided into segments and subjected to organ culture for 48 hours. The vessels were then examined by using in vitro...... pharmacological methods and molecular biological techniques. RESULTS: After organ culture of the cerebral arteries, both the sensitivity to and potency of ET were enhanced (maximal response, 152 +/- 9%; -log (50% effective concentration), 10.3 +/- 0.3), in comparison with data for fresh cerebral arteries...

Relationship between insulin resistance and plasma endothelin in hypertension patients

International Nuclear Information System (INIS)

Duan Yongqiang; Wang Zuobing; Yu Hui; Cao Wei; Wang Jing; Li Xiaoqin

2011-01-01

To explore the relationship between plasma endothelin and hypertension insulin resistance, and the improvement of insulin resistance in hypertension patients treated with captopril and l-amlodipine, 25 patients with primary hypertension and impaired glucose tolerance were selected and treated by captopril and l-amlodipine. Systolic pressure, diastolic pressure, fasting blood glucose, insulin and insulin antibody were measured before and after treatment and compared with healthy controls. The results showed that the plasma ET-1 level in hypertension group was significantly higher than that of healthy controls (P<0.01), and he plasma ET-1 level was positively correlated with FPG, FINS, Anti-INS, HOMA-IR. The systolic pressure, diastolic pressure, fasting blood glucose, insulin, insulin antibody and insulin resistance index in hypertension patients were decreased significantly after treatment (P<0.05). There is a good correlation between endothelin and insulin resistance index in hypertension patients. Captopril and l-amlodipine had obvious improvement effect on insulin resistance in hypertension patients. (authors)

Association studies suggest a key role for endothelin-1 in the pathogenesis of preeclampsia and the accompanying renin-angiotensin-aldosterone system suppression.

Science.gov (United States)

Verdonk, Koen; Saleh, Langeza; Lankhorst, Stephanie; Smilde, J E Ilse; van Ingen, Manon M; Garrelds, Ingrid M; Friesema, Edith C H; Russcher, Henk; van den Meiracker, Anton H; Visser, Willy; Danser, A H Jan

2015-06-01

Women with preeclampsia display low renin-angiotensin-aldosterone system activity and a high antiangiogenic state, the latter characterized by high levels of soluble Fms-like tyrosine kinase (sFlt)-1 and reduced placental growth factor levels. To investigate whether renin-angiotensin-aldosterone system suppression in preeclampsia is because of this disturbed angiogenic balance, we measured mean arterial pressure, creatinine, endothelin-1 (ET-1), and renin-angiotensin-aldosterone system components in pregnant women with a high (≥85; n=38) or low (<85; n=65) soluble Fms-like tyrosine kinase-1/placental growth factor ratio. Plasma ET-1 levels were increased in women with a high ratio, whereas their plasma renin activity and plasma concentrations of renin, angiotensinogen, and aldosterone were decreased. Plasma renin activity-aldosterone relationships were identical in both the groups. Multiple regression analysis revealed that plasma renin concentration correlated independently with mean arterial pressure and plasma ET-1. Plasma ET-1 correlated positively with soluble Fms-like tyrosine kinase-1 and negatively with plasma renin concentration, and urinary protein correlated with plasma ET-1 and mean arterial pressure. Despite the lower plasma levels of renin and angiotensinogen in the high-ratio group, their urinary levels of these components were elevated. Correction for albumin revealed that this was because of increased glomerular filtration. Subcutaneous arteries obtained from patients with preeclampsia displayed an enhanced, AT2 receptor-mediated response to angiotensin II. In conclusion, a high antiangiogenic state associates with ET-1 activation, which together with the increased mean arterial pressure may underlie the parallel reductions in renin and aldosterone in preeclampsia. Because ET-1 also was a major determinant of urinary protein, our data reveal a key role for ET-1 in the pathogenesis of preeclampsia. Finally, the enhanced angiotensin responsiveness

Discovery of a Series of Imidazo[4,5-b]pyridines with Dual Activity at Angiotensin II Type 1 Receptor and Peroxisome Proliferator-Activated Receptor-[gamma

Energy Technology Data Exchange (ETDEWEB)

Casimiro-Garcia, Agustin; Filzen, Gary F.; Flynn, Declan; Bigge, Christopher F.; Chen, Jing; Davis, Jo Ann; Dudley, Danette A.; Edmunds, Jeremy J.; Esmaeil, Nadia; Geyer, Andrew; Heemstra, Ronald J.; Jalaie, Mehran; Ohren, Jeffrey F.; Ostroski, Robert; Ellis, Teresa; Schaum, Robert P.; Stoner, Chad (Pfizer)

2013-03-07

Mining of an in-house collection of angiotensin II type 1 receptor antagonists to identify compounds with activity at the peroxisome proliferator-activated receptor-{gamma} (PPAR{gamma}) revealed a new series of imidazo[4,5-b]pyridines 2 possessing activity at these two receptors. Early availability of the crystal structure of the lead compound 2a bound to the ligand binding domain of human PPAR{gamma} confirmed the mode of interaction of this scaffold to the nuclear receptor and assisted in the optimization of PPAR{gamma} activity. Among the new compounds, (S)-3-(5-(2-(1H-tetrazol-5-yl)phenyl)-2,3-dihydro-1H-inden-1-yl)-2-ethyl-5-isobutyl-7-methyl-3H-imidazo[4,5-b]pyridine (2l) was identified as a potent angiotensin II type I receptor blocker (IC{sub 50} = 1.6 nM) with partial PPAR{gamma} agonism (EC{sub 50} = 212 nM, 31% max) and oral bioavailability in rat. The dual pharmacology of 2l was demonstrated in animal models of hypertension (SHR) and insulin resistance (ZDF rat). In the SHR, 2l was highly efficacious in lowering blood pressure, while robust lowering of glucose and triglycerides was observed in the male ZDF rat.

Down-regulation of endothelin binding sites in rat vascular smooth muscle cells

International Nuclear Information System (INIS)

Roubert, P.; Gillard, V.; Plas, P.; Chabrier, P.E.; Braquet, P.

1990-01-01

In cultured rat aortic smooth muscle cells, [ 125 I]endothelin (ET-1) bound to an apparent single class of high affinity recognition sites with a dissociation constant of 1.84 +/- 0.29 nmol/L and a maximum binding of 62 +/- 10.5 fmol/10(6) cells. The binding was not affected by calcium antagonists or vasoactive substances, including angiotensin II, arginine vasopressin, atrial natriuretic factor and bradykinin. Exposure of the cells to ET-1 (0.01 nmol/L to 10 nmol/L) resulted in an apparent dose-dependent reduction of the number of endothelin binding sites with no significant modification of its binding affinity. The time course of the down-regulation of ET-1 binding sites showed that this effect was present after 30 min incubation and persisted after 18 h. This indicates that down-regulation of ET-1 binding sites can modulate the activity of ET-1 and suggests a rapid internalization of ET-1 in vascular cells

Influence of radiographic contrast media (Iodixanol and Iomeprol) on the endothelin-1 release from human arterial and venous endothelial cells cultured on an extracellular matrix.

Science.gov (United States)

Franke, R P; Fuhrmann, R; Hiebl, B; Jung, F

2012-01-01

Various radiographic contrast media (RCM) are available for visualization of blood vessels in interventional cardiology which can vary widely in their physicochemical properties thereby influencing different functions of blood cells. In the in vitro study described here the influence of two RCMs on arterial as well as on venous endothelial cells was compared to control cultures and examined under statical culture conditions, thus eliminating the influence of RCM viscosity almost completely. The supplementation of the culture medium with RCM (30% v/v) resulted in clearly different reactions of the endothelial cells exposed. Exposition to Iodixanol supplemented culture medium was followed by endothelin-1 release from venous endothelial cells which was equivalent to the endothelin-1 release from venous control cultures. Compared to control cultures, venous endothelial cells exposed to culture medium supplemented with Iomeprol displayed a completely different reaction, the increase in endothelin-1 secretion was missing completely after a 12 hours exposure. Following a 12 hours exposure to both RCMs there were no longer endothelial cells adherent, neither in venous nor in arterial endothelial cell cultures. The study showed that not the wall shear stress was responsible for the differing effects visible after 1.5 min, 5 min, and 12 hours exposure to culture media supplemented with RCM but differences in chemotoxicity of the RCM applied.

Endothelin-1 is a Risk Factor for Pathogenesis of Hypertension

International Nuclear Information System (INIS)

Abdelhalim, Mohamed Anwar K.

2007-01-01

The purpose of this present study was to investigate the effects of endothelin-1 (ET-1) on the systemic blood pressure, microvascular blood flow velocity and diameter of arterioles and venules of the rat mesentery in vivo. For this purpose, the mesentery was arranged for in situ intravital microscopic observation under transillumination, and cumulative injections of ET-1(30-2000 p mole/kg) were infused intravenously through a catheter inserted into the right jugular vein. Infusion of low doses of ET-1(30-125 pmole/kg) induced a slight increase in the systemic blood pressure, a dose-dependent increase in blood flow velocity of arterioles (20-30 micron m) and venules (30-50 micron m). Diameters of arterioles and venules exhibited no significant change as compared with the control data. On the contrary, the infusion of high doses of ET-1 (250-2000 pmole/kg) induced a long-lasting pressor effect, a dose-dependent decrease in the blood flow velocity of arterioles and venules. Microvascular diameter exhibited a vasoconstrictive effect more prominent in arterioles than in venules. These findings suggest that vasoconstriction produced by ET-1 in rat mesenteric microcirculation may be the causal factor for its potent pressor effect in rats. Moreover, ET-1 may be involved in the regulation of the blood flow velocity distribution of rat mesenteric microcirculation. Finally, ET-1 may be considered as one of the more important risk factors which contribute to the pathogenesis of hypertension. (author)

On the Emerging Role of the Taste Receptor Type 1 (T1R Family of Nutrient-Sensors in the Musculoskeletal System

Directory of Open Access Journals (Sweden)

Shoichiro Kokabu

2017-03-01

Full Text Available The special sense of taste guides and guards food intake and is essential for body maintenance. Salty and sour tastes are sensed via ion channels or gated ion channels while G protein-coupled receptors (GPCRs of the taste receptor type 1 (T1R family sense sweet and umami tastes and GPCRs of the taste receptor type 2 (T2R family sense bitter tastes. T1R and T2R receptors share similar downstream signaling pathways that result in the stimulation of phospholipase-C-β2. The T1R family includes three members that form heterodimeric complexes to recognize either amino acids or sweet molecules such as glucose. Although these functions were originally described in gustatory tissue, T1R family members are expressed in numerous non-gustatory tissues and are now viewed as nutrient sensors that play important roles in monitoring global glucose and amino acid status. Here, we highlight emerging evidence detailing the function of T1R family members in the musculoskeletal system and review these findings in the context of the musculoskeletal diseases sarcopenia and osteoporosis, which are major public health problems among the elderly that affect locomotion, activities of daily living, and quality of life. These studies raise the possibility that T1R family member function may be modulated for therapeutic benefit.

Insulin-like growth factor type-1 receptor down-regulation associated with dwarfism in Holstein calves.

Science.gov (United States)

Blum, J W; Elsasser, T H; Greger, D L; Wittenberg, S; de Vries, F; Distl, O

2007-10-01

Perturbations in endocrine functions can impact normal growth. Endocrine traits were studied in three dwarf calves exhibiting retarded but proportionate growth and four phenotypically normal half-siblings, sired by the same bull, and four unrelated control calves. Plasma 3,5,3'-triiodothyronine and thyroxine concentrations in dwarfs and half-siblings were in the physiological range and responded normally to injected thyroid-releasing hormone. Plasma glucagon concentrations were different (dwarfs, controls>half-siblings; Pcontrols, Pcontrols, P=0.08). Responses of GH to xylazine and to a GH-releasing-factor analogue were similar in dwarfs and half-siblings. Relative gene expression of IGF-1, IGF-2, GH receptor (GHR), insulin receptor, IGF-1 type-1 and -2 receptors (IGF-1R, IGF-2R), and IGF binding proteins were measured in liver and anconeus muscle. GHR mRNA levels were different in liver (dwarfsdwarfism in studied calves.

Endothelins in chronic liver disease

DEFF Research Database (Denmark)

Møller, S; Henriksen, Jens Henrik Sahl

1996-01-01

renal failure. Studies on liver biopsies have revealed synthesis of ET-1 in hepatic endothelial and other cells, and recent investigations have identified the hepatosplanchnic system as a major source of ET-1 and ET-3 spillover into the circulation, with a direct relation to portal venous hypertension......This review describes recent progress in the accumulation of knowledge about the endothelins (ETs), a family of vasoactive 21-amino acid polypeptides, in chronic liver disease. Particular prominence is given to the dynamics of ET-1 and ET-3 and their possible relation to the disturbed circulation....... In addition, marked associations with disturbance of systemic haemodynamics and with abnormal distribution of blood volume have been reported. Although the pathophysiological importance of the ET system in chronic liver disease is not completely understood, similarities to other vasopressive...

Mesenchymal Stem Cells Sense Three Dimensional Type I Collagen through Discoidin Domain Receptor 1.

Science.gov (United States)

Lund, A W; Stegemann, J P; Plopper, G E

2009-01-01

The extracellular matrix provides structural and organizational cues for tissue development and defines and maintains cellular phenotype during cell fate determination. Multipotent mesenchymal stem cells use this matrix to tightly regulate the balance between their differentiation potential and self-renewal in the native niche. When understood, the mechanisms that govern cell-matrix crosstalk during differentiation will allow for efficient engineering of natural and synthetic matrices to specifically direct and maintain stem cell phenotype. This work identifies the discoidin domain receptor 1 (DDR1), a collagen activated receptor tyrosine kinase, as a potential link through which stem cells sense and respond to the 3D organization of their extracellular matrix microenvironment. DDR1 is dependent upon both the structure and proteolytic state of its collagen ligand and is specifically expressed and localized in three dimensional type I collagen culture. Inhibition of DDR1 expression results in decreased osteogenic potential, increased cell spreading, stress fiber formation and ERK1/2 phosphorylation. Additionally, loss of DDR1 activity alters the cell-mediated organization of the naïve type I collagen matrix. Taken together, these results demonstrate a role for DDR1 in the stem cell response to and interaction with three dimensional type I collagen. Dynamic changes in cell shape in 3D culture and the tuning of the local ECM microstructure, directs crosstalk between DDR1 and two dimensional mechanisms of osteogenesis that can alter their traditional roles.

Expression of endothelin-1 gene and protein in human granulosa cells

Energy Technology Data Exchange (ETDEWEB)

Magini, A.; Granchi, S.; Susini, T. [Univ. of Florence (Italy)] [and others

1996-04-01

Previous studies in animal models indicated an autocrine/paracrine action of endothelin-1 (ET-1) in the ovary. We now report evidence on the presence of ET-1 in human ovary during reproductive life. Immunohistochemical and in situ hybridization studies demonstrated a positive signal into cytoplasm of granulosa cells (GC) of follicles at different growth stages. The concentration of ET-1-like immunoreactivity (ET-1-Li) was also measured by a specific RIA in human follicular fluid (FF). FF samples were obtained from women in an in vitro fertilization program undergoing gonadotropin stimulation (group A; n = 24) or no treatment (group B; n = 7). The mean ({+-}SD) ET-1-LI FF level in group A (4.85 {+-} 2.06 pg/mL) was significantly higher than that in group B (1.29 {+-} 0.43 pg/mL; P < 0.01), whereas the corresponding mean plasma levels were not significantly different and were not correlated to respective FF values. Our results indicate for the first time the presence of ET-1 and its messenger ribonucleic acid in the GC of the human ovary. The higher ET-1-LI levels found in the FF from women undergoing gonadotropin treatment suggest a modulation by gonadotropins and/or ovarian steroids of ET-1 production by GC. 19 refs., 4 figs., 1 tab.

Molecular characterization of a novel human hybrid-type receptor that binds the alpha2-macroglobulin receptor-associated protein

DEFF Research Database (Denmark)

Jacobsen, Linda; Madsen, P; Moestrup, S K

1996-01-01

the corresponding cDNA. The gene, designated SORL1, maps to chromosome 11q 23/24 and encodes a 2214-residue type 1 receptor containing a furin cleavage site immediately preceding the N terminus determined in the purified protein. The receptor, designated sorLA-1, has a short cytoplasmic tail containing a tyrosine...... density lipoprotein receptor gene family receptors, and 3) six tandemly arranged fibronectin type III repeats also found in certain neural adhesion proteins. sorLA-1 may therefore be classified as a hybrid receptor. Northern blotting revealed specific mRNA transcripts in brain, spinal cord, and testis......The 39-40-kDa receptor-associated protein (RAP) binds to the members of the low density lipoprotein receptor gene family and functions as a specialized endoplasmic reticulum/Golgi chaperone. Using RAP affinity chromatography, we have purified a novel approximately 250-kDa brain protein and isolated...

Functional ET(A)-ET(B) Receptor Cross-talk in Basilar Artery In Situ From ET(B) Receptor Deficient Rats.

Science.gov (United States)

Yoon, SeongHun; Gariepy, Cheryl E; Yanagisawa, Masashi; Zuccarello, Mario; Rapoport, Robert M

2016-03-01

The role of endothelin (ET)(A)-ET(B) receptor cross-talk in limiting the ET(A) receptor antagonist inhibition of ET-1 constriction is revealed by the partial or complete dependency of the ET(A) receptor antagonist inhibition on functional removal of the ET(B) receptor. Although functional removal of the ET(B) receptor is generally accomplished with ET(B) receptor antagonist, a novel approach using rats containing a naturally occurring deletion mutation in the ET(B) receptor [rescued "spotting lethal" (sl) rats; ET(B)(sl/sl)] demonstrated increased ET(A) receptor antagonist inhibition of ET-1 constriction in vena cava. We investigated whether this deletion mutation was also sufficient to remove the ET(B) receptor dependency of the ET(A) receptor antagonist inhibition of ET-1 constriction in the basilar artery. Consistent with previous reports, ET-1 plasma levels were elevated in ET(B)(sl/sl) as compared with ET(B)(+/+) rats. ET(B) receptor antagonist failed to relax the ET-1 constricted basilar artery from ET(B)(+/+) and ET(B)(sl/sl) rats. Relaxation to combined ET(A) and ET(B) receptor antagonist was greater than relaxation to ET(A) receptor antagonist in the basilar artery from ET(B)(+/+) and, unexpectedly, ET(B)(sl/sl) rats. These findings confirm the presence of ET(A)-ET(B) receptor cross-talk in the basilar artery. We speculate that mutant ET(B) receptor expression produced by alternative splicing may be sufficient to allow cross-talk.

Casein Kinase 1α Mediates the Degradation of Receptors for Type I and Type II Interferons Caused by Hemagglutinin of Influenza A Virus.

Science.gov (United States)

Xia, Chuan; Wolf, Jennifer J; Vijayan, Madhuvanthi; Studstill, Caleb J; Ma, Wenjun; Hahm, Bumsuk

2018-04-01

Although influenza A virus (IAV) evades cellular defense systems to effectively propagate in the host, the viral immune-evasive mechanisms are incompletely understood. Our recent data showed that hemagglutinin (HA) of IAV induces degradation of type I IFN receptor 1 (IFNAR1). Here, we demonstrate that IAV HA induces degradation of type II IFN (IFN-γ) receptor 1 (IFNGR1), as well as IFNAR1, via casein kinase 1α (CK1α), resulting in the impairment of cellular responsiveness to both type I and II IFNs. IAV infection or transient HA expression induced degradation of both IFNGR1 and IFNAR1, whereas HA gene-deficient IAV failed to downregulate the receptors. IAV HA caused the phosphorylation and ubiquitination of IFNGR1, leading to the lysosome-dependent degradation of IFNGR1. Influenza viral HA strongly decreased cellular sensitivity to type II IFNs, as it suppressed the activation of STAT1 and the induction of IFN-γ-stimulated genes in response to exogenously supplied recombinant IFN-γ. Importantly, CK1α, but not p38 MAP kinase or protein kinase D2, was proven to be critical for HA-induced degradation of both IFNGR1 and IFNAR1. Pharmacologic inhibition of CK1α or small interfering RNA (siRNA)-based knockdown of CK1α repressed the degradation processes of both IFNGR1 and IFNAR1 triggered by IAV infection. Further, CK1α was shown to be pivotal for proficient replication of IAV. Collectively, the results suggest that IAV HA induces degradation of IFN receptors via CK1α, creating conditions favorable for viral propagation. Therefore, the study uncovers a new immune-evasive pathway of influenza virus. IMPORTANCE Influenza A virus (IAV) remains a grave threat to humans, causing seasonal and pandemic influenza. Upon infection, innate and adaptive immunity, such as the interferon (IFN) response, is induced to protect hosts against IAV infection. However, IAV seems to be equipped with tactics to evade the IFN-mediated antiviral responses, although the detailed

Effects of NR1 splicing on NR1/NR3B-type excitatory glycine receptors

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Orth Angela

2009-04-01

Full Text Available Abstract Background N-methyl-D-aspartate receptors (NMDARs are the most complex of ionotropic glutamate receptors (iGluRs. Subunits of this subfamily assemble into heteromers, which – depending on the subunit combination – may display very different pharmacological and electrophysiological properties. The least studied members of the NMDAR family, the NR3 subunits, have been reported to assemble with NR1 to form excitatory glycine receptors in heterologous expression systems. The heterogeneity of NMDARs in vivo is in part conferred to the receptors by splicing of the NR1 subunit, especially with regard to proton sensitivity. Results Here, we have investigated whether the NR3B subunit is capable of assembly with each of the eight functional NR1 splice variants, and whether the resulting receptors share the unique functional properties described for NR1-1a/NR3. We provide evidence that functional excitatory glycine receptors formed regardless of the NR1 isoform, and their pharmacological profile matched the one reported for NR1-1a/NR3: glycine alone fully activated the receptors, which were insensitive to glutamate and block by Mg2+. Surprisingly, amplitudes of agonist-induced currents showed little dependency on the C-terminally spliced NR1 variants in NR1/NR3B diheteromers. Even more strikingly, NR3B conferred proton sensitivity also to receptors containing NR1b variants – possibly via disturbing the "proton shield" of NR1b splice variants. Conclusion While functional assembly could be demonstrated for all combinations, not all of the specific interactions seen for NR1 isoforms with coexpressed NR2 subunits could be corroborated for NR1 assembly with NR3. Rather, NR3 abates trafficking effects mediated by the NR1 C terminus as well as the N-terminally mediated proton insensitivity. Thus, this study establishes that NR3B overrides important NR1 splice variant-specific receptor properties in NR1/NR3B excitatory glycine receptors.

Homozygous EDNRB mutation in a patient with Waardenburg syndrome type 1.

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Morimoto, Noriko; Mutai, Hideki; Namba, Kazunori; Kaneko, Hiroki; Kosaki, Rika; Matsunaga, Tatsuo

2018-04-01

To examine and expand the genetic spectrum of Waardenburg syndrome type 1 (WS1). Clinical features related to Waardenburg syndrome (WS) were examined in a five-year old patient. Mutation analysis of genes related to WS was performed in the proband and her parents. Molecular modeling of EDNRB and the p.R319W mutant was conducted to predict the pathogenicity of the mutation. The proband showed sensorineural hearing loss, heterochromia iridis, and dystopia canthorum, fulfilling the clinical criteria of WS1. Genetic analyses revealed that the proband had no mutation in PAX3 which has been known as the cause of WS1, but had a homozygous missense mutation (p.R319W) in endothelin receptor type B (EDNRB) gene. The asymptomatic parents had the mutation in a heterozygote state. This mutation has been previously reported in a heterozygous state in a patient with Hirschsprung's disease unaccompanied by WS, but the patient and her parents did not show any symptoms in gastrointestinal tract. Molecular modeling of EDNRB with the p.R319W mutation demonstrated reduction of the positively charged surface area in this region, which might reduce binding ability of EDNRB to G protein and lead to abnormal signal transduction underlying the WS phenotype. Our findings suggested that autosomal recessive mutation in EDNRB may underlie a part of WS1 with the current diagnostic criteria, and supported that Hirschsprung's disease is a multifactorial genetic disease which requires additional factors. Further molecular analysis is necessary to elucidate the gene interaction and to reappraise the current WS classification. Copyright © 2017 Elsevier B.V. All rights reserved.

Permanent Distal Occlusion of Middle Cerebral Artery in Rat Causes Local Increased ETB, 5-HT1B and AT1 Receptor-Mediated Contractility Downstream of Occlusion

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Rasmussen, Marianne N P; Hornbak, Malene; Larsen, Stine S

2013-01-01

Background/Aims: In response to experimental stroke, a characteristic functional and expressional upregulation of contractile G-protein-coupled receptors has been uncovered in the affected cerebral vasculature; however, the mechanism initiating this phenomenon remains unknown. Methods: Using...... a model of permanent distal occlusion of rat middle cerebral arteries, we investigated whether there was a regional difference in receptor-mediated contractility of segments located upstream and downstream of the occlusion site. The contractile response to endothelin, angiotensin and 5-hydroxytryptamine...... receptor stimulation was studied by sensitive wire myograph. Results: Only downstream segments exhibited an augmented contractile response to stimulation with each of the three ligands, with the response towards sarafotoxin 6c being especially augmented compared to sham, upstream and contralateral controls...

Evaluation of Homocysteine, Lipoprotein(a and Endothelin as diagnostic markers of Coronary Artery Disease in Indian population

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Vandana Saini

2013-01-01

Full Text Available Indians have been reported to have high prevalence rates of coronary artery disease (CAD even in the absence of traditional risk factors. The objective of this study was to assess the role of endothelin, lipoprotein(a, homocysteine and lipid profile as markers of CAD in Indian population. It was a hospital based observational case-control study, which included 60 documented patients of CAD, and 50 age and sex matched controls. Routine biochemical parameters were performed. Lipoprotein(a, homocysteine and endothelin levels were estimated by enzyme linked immunosorbent assay. The levels of endothelin (9.78±0.40 pg/ml vs. 7.86±0.31 pg/ml, lipoprotein(a (51.42±1.71 mg/dl vs. 36.26±1.21 mg/dl, homocysteine (21.31±1.22 µmol/L vs. 10.41±0.844 µmol/L and LDL/HDL cholesterol ratio (4.23±0.32 vs. 2.60±0.10 were significantly higher whereas that of HDL (29.82±1.39 mg/dl vs. 40.82±6.24 mg/dl was significantly lower in patients of CAD as compared to the controls (p0.7 for all the markers. Higher levels of homocysteine, endothelin, and lipoprotein(a were independently associated with increased risk of CAD. Thus, they may be helpful in risk assessment in premature cardiovascular disease and in individuals where traditional risk factors are not present.

Endothelin-1 overexpression exacerbates atherosclerosis and induces aortic aneurysms in apolipoprotein E knockout mice.

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Li, Melissa W; Mian, Muhammad Oneeb Rehman; Barhoumi, Tlili; Rehman, Asia; Mann, Koren; Paradis, Pierre; Schiffrin, Ernesto L

2013-10-01

Endothelin (ET)-1 plays a role in vascular reactive oxygen species production and inflammation. ET-1 has been implicated in human atherosclerosis and abdominal aortic aneurysm (AAA) development. ET-1 overexpression exacerbates high-fat diet-induced atherosclerosis in apolipoprotein E(-/-) (Apoe(-/-)) mice. ET-1-induced reactive oxygen species and inflammation may contribute to atherosclerosis progression and AAA development. Eight-week-old male wild-type mice, transgenic mice overexpressing ET-1 selectively in endothelium (eET-1), Apoe(-/-) mice, and eET-1/Apoe(-/-) mice were fed high-fat diet for 8 weeks. eET-1/Apoe(-/-) had a 45% reduction in plasma high-density lipoprotein (P<0.05) and presented ≥ 2-fold more aortic atherosclerotic lesions compared with Apoe(-/-) (P<0.01). AAAs were detected only in eET-1/Apoe(-/-) (8/21; P<0.05). Reactive oxygen species production was increased ≥ 2-fold in perivascular fat, media, or atherosclerotic lesions in the ascending aorta and AAAs of eET-1/Apoe(-/-) compared with Apoe(-/-) (P<0.05). Monocyte/macrophage infiltration was enhanced ≥ 2.5-fold in perivascular fat of ascending aorta and AAAs in eET-1/Apoe(-/-) compared with Apoe(-/-) (P<0.05). CD4(+) T cells were detected almost exclusively in perivascular fat (3/6) and atherosclerotic lesions (5/6) in ascending aorta of eET-1/Apoe(-/-) (P<0.05). The percentage of spleen proinflammatory Ly-6C(hi) monocytes was enhanced 26% by ET-1 overexpression in Apoe(-/-) (P<0.05), and matrix metalloproteinase-2 was increased 2-fold in plaques of eET-1/Apoe(-/-) (P<0.05) compared with Apoe(-/-). ET-1 plays a role in progression of atherosclerosis and AAA formation by decreasing high-density lipoprotein, and increasing oxidative stress, inflammatory cell infiltration, and matrix metalloproteinase-2 in perivascular fat, vascular wall, and atherosclerotic lesions.

Determination of HIV-1 co-receptor usage.

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Cavarelli, Mariangela; Scarlatti, Gabriella

2014-01-01

Human immunodeficiency virus type I (HIV-1) infects target cells through interaction with the CD4 molecule and chemokine receptors, mainly the β-chemokine receptor 5 (CCR5) and the α-chemokine receptor 4 (CXCR4). Viral isolates can be phenotypically classified based on the co-receptor they utilize to infect target cells. In this chapter, methods to determine the co-receptor usage of HIV-1 variants are described.

Cardiac Alpha1-Adrenergic Receptors: Novel Aspects of Expression, Signaling Mechanisms, Physiologic Function, and Clinical Importance

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O’Connell, Timothy D.; Jensen, Brian C.; Baker, Anthony J.

2014-01-01

Adrenergic receptors (AR) are G-protein-coupled receptors (GPCRs) that have a crucial role in cardiac physiology in health and disease. Alpha1-ARs signal through Gαq, and signaling through Gq, for example, by endothelin and angiotensin receptors, is thought to be detrimental to the heart. In contrast, cardiac alpha1-ARs mediate important protective and adaptive functions in the heart, although alpha1-ARs are only a minor fraction of total cardiac ARs. Cardiac alpha1-ARs activate pleiotropic downstream signaling to prevent pathologic remodeling in heart failure. Mechanisms defined in animal and cell models include activation of adaptive hypertrophy, prevention of cardiac myocyte death, augmentation of contractility, and induction of ischemic preconditioning. Surprisingly, at the molecular level, alpha1-ARs localize to and signal at the nucleus in cardiac myocytes, and, unlike most GPCRs, activate “inside-out” signaling to cause cardioprotection. Contrary to past opinion, human cardiac alpha1-AR expression is similar to that in the mouse, where alpha1-AR effects are seen most convincingly in knockout models. Human clinical studies show that alpha1-blockade worsens heart failure in hypertension and does not improve outcomes in heart failure, implying a cardioprotective role for human alpha1-ARs. In summary, these findings identify novel functional and mechanistic aspects of cardiac alpha1-AR function and suggest that activation of cardiac alpha1-AR might be a viable therapeutic strategy in heart failure. PMID:24368739

The ocular endothelin system: a novel target for the treatment of endotoxin-induced uveitis with bosentan.

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Keles, Sadullah; Halici, Zekai; Atmaca, Hasan Tarik; Yayla, Muhammed; Yildirim, Kenan; Ekinci, Metin; Akpinar, Erol; Altuner, Durdu; Cakici, Ozgur; Bayraktutan, Zafer

2014-05-15

We compared the anti-inflammatory effects of bosentan and dexamethasone in endotoxin-induced uveitis (EIU). Endotoxin-induced uveitis was induced by subcutaneous injection of lipopolysaccharide (LPS, 200 μg) in Wistar rats. Rats were divided randomly into 10 groups (n = 6). Bosentan at doses of 50 and 100 mg/kg were administered orally 1 hour before and 12 hours after LPS injection, and dexamethasone was administered by intraperitoneally 30 minutes before and 30 minutes after LPS injection at a dose of 1 mg/kg. Data were collected at two time points for each control and treatment; animals were killed at either 3 or 24 hours after LPS injection. Histopathologic evaluation and aqueous humour measurements of TNF-α level were performed, and endothelin-1 (ET-1), inducible nitric oxide synthase (iNOS), and endothelin receptor A and B (EDNRA and B) expression were analyzed. The group treated with 100 mg/kg bosentan at 24 hours displayed significantly milder uveitis and fewer inflammatory cells compared to LPS-injected animals, and there were similar findings in the dexamethasone-treated group at 24 hours. The TNF-α levels in the dexamethasone treatment group were lower than those in the LPS-induced uveitis control group (P treatment groups at 3 and 24 hours after LPS administration. Bosentan treatment at doses of 50 and 100 mg/kg significantly decreased iNOS expression compared to LPS-injected animals (P treatment groups was statistically significantly lower than that in the LPS-induced uveitis control group at 3 and 24 hours after LPS administration (P < 0.05). Bosentan reduces intraocular inflammation and has similar effects as dexamethasone in a rat model of EIU. Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.

Enhanced expressions of microvascular smooth muscle receptors after focal cerebral ischemia occur via the MAPK MEK/ERK pathway

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Edvinsson Lars

2008-09-01

Full Text Available Abstract Background MEK1/2 is a serine/threonine protein that phosphorylates extracellular signal-regulated kinase (ERK1/2. Cerebral ischemia results in enhanced expression of cerebrovascular contractile receptors in the middle cerebral artery (MCA leading to the ischemic region. Here we explored the role of the MEK/ERK pathway in receptor expression following ischemic brain injury using the specific MEK1 inhibitor U0126. Methods and result Rats were subjected to a 2-h middle cerebral artery occlusion (MCAO followed by reperfusion for 48-h and the ischemic area was calculated. The expression of phosphorylated ERK1/2 and Elk-1, and of endothelin ETA and ETB, angiotensin AT1, and 5-hydroxytryptamine 5-HT1B receptors were analyzed with immunohistochemistry using confocal microscopy in cerebral arteries, microvessels and in brain tissue. The expression of endothelin ETB receptor was analyzed by quantitative Western blot. We demonstrate that there is an increase in the number of contractile smooth muscle receptors in the MCA and in micro- vessels within the ischemic region. The enhanced expression occurs in the smooth muscle cells as verified by co-localization studies. This receptor upregulation is furthermore associated with enhanced expression of pERK1/2 and of transcription factor pElk-1 in the vascular smooth muscle cells. Blockade of transcription with the MEK1 inhibitor U0126, given at the onset of reperfusion or as late as 6 hours after the insult, reduced transcription (pERK1/2 and pElk-1, the enhanced vascular receptor expression, and attenuated the cerebral infarct and improved neurology score. Conclusion Our results show that MCAO results in upregulation of cerebrovascular ETB, AT1 and 5-HT1B receptors. Blockade of this event with a MEK1 inhibitor as late as 6 h after the insult reduced the enhanced vascular receptor expression and the associated cerebral infarction.

Association of connexin43 with a receptor protein tyrosine phosphatase

NARCIS (Netherlands)

Giepmans, Ben N G; Feiken, Elles; Gebbink, Martijn F B G; Moolenaar, Wouter H

2003-01-01

Connexin-43(Cx43)-based gap junctional communication is transiently inhibited by certain G protein-coupled receptor agonists, including lysophosphatidic acid, endothelin and thrombin. Our previous studies have implicated the c-Src protein tyrosine kinase in mediating closure of Cx43 based gap

Intrahippocampal injection of endothelin-1 in immature rats results in neuronal death, development of epilepsy and behavioral abnormalities later in life