Central Endothelin-1 Confers Analgesia by Triggering Spinal Neuronal Histone Deacetylase 5 (HDAC5) Nuclear Exclusion in Peripheral Neuropathic Pain in Mice.

The rationale of spinal administration of endothelin-1(ET-1) mediated anti-nociceptive effect has not been elucidated. ET-1 is reported to promote nuclear effluxion of histone deacetylase 5 (HDAC5) in myocytes, and spinal HDAC5 is implicated in modulation of pain processing. In this study, we aimed to investigate whether central ET-1 plays an anti-nociceptive role by facilitating spinal HDAC5 nuclear shuttling under neuropathic pain. Here, we demonstrate that upregulating spinal ET-1 attenuated the nociception induced by partial sciatic nerve ligation surgery and this analgesic effect mediated by ET-1 was attenuated by intrathecal injection of endothelin A receptor selective inhibitor (BQ123) or by blocking the exportation of nuclear HDAC5 by adeno-associated viruses targeting neuronal HDAC5 (AVV-HDAC5 S259/498A Mutant). Notably, ET-1 administration increased spinal glutamate acid decarboxylases (GAD65/67) expression via initiating HDAC5 nuclear exportation and increased the acetylation of histone 3 at lysine 9 (Acetyl-H3K9) in the promotor regions of spinal Gad1 and Gad2 genes. This was reversed by blocking endothelin A receptor function or by inhibiting the spinal neuronal nuclear exportation of HDAC5. Therefore, inducing spinal GABAergic neuronal HDAC5 nuclear exportation may be a novel therapeutic approach for managing neuropathic pain. PERSPECTIVE: Neuropathic pain is intractable in a clinical setting, and epigenetic regulation is considered to contribute to this processing. Characterizing the anti-nociceptive effect of ET-1 and investigating the associated epigenetic mechanisms in animal models may lead to the development of new therapeutic strategies and targets for treating neuropathic pain.

17-Hydroxyprogesterone caproate improves hypertension and renal endothelin-1 in response to sFlt-1 induced hypertension in pregnant rats.

Preeclampsia (PE) is characterized by new onset hypertension in association with elevated soluble fms-like tyrosine kinase-1 (sFlt-1) and preproendothelin-1 (PPET-1) levels. Currently there is no effective treatment for PE except for early delivery of the fetal placental unit, making PE a leading cause for premature births worldwide. Administration of 17-hydroxyprogesterone caproate (17-OHPC) is used for prevention of recurrent preterm birth. This study was designed to test the hypothesis that 17-OHPC improves hypertension and ET-1 in response to elevated sFlt-1 in pregnant rats. sFlt-1 was infused into normal pregnant (NP) Sprague-Dawley rats (3.7 µg·kg-1·day-1 for 6 days, gestation days 13-19) in the presence or absence of 17-OHPC (3.32 mg/kg) administered via intraperitoneal injection on gestational days 15 and 18. Mean arterial blood pressure (MAP), pup and placenta weights, renal cortex PPET-1 mRNA levels and nitrate-nitrite levels were measured on GD 19. Infusion of sFlt-1 into NP rats elevated mean arterial pressure (MAP) compared with control NP rats: 115 ± 1 (n = 13) vs. 99 ± 2 mmHg (n = 12, p < 0.05). 17-OHPC attenuated this hypertension reducing MAP to 102 ± 3 mmHg in sFlt-1 treated pregnant rats (n = 8). Neither pup nor placental weight was affected by sFlt-1 or 17-OHPC. Importantly, renal cortex PPET-1 mRNA levels were elevated 3 fold in NP + sFlt-1 rats compare to NP rats, which decreased with 17-OHPC administration. Plasma nitrate-nitrite levels were 44 ± 9 µM in NP rats (n = 9), 20 ± 3 µM in NP + sFlt-1 (n = 7), which increased to 42 ± 11 µM NP + sFlt-1 + 17OHPC (n = 6). Administration of 17-OHPC improves clinical characteristics of preeclampsia in response to elevated sFlt-1 during pregnancy.

Inhibition of NFAT Signaling Restores Microvascular Endothelial Function in Diabetic Mice.

Central to the development of diabetic macro- and microvascular disease is endothelial dysfunction, which appears well before any clinical sign but, importantly, is potentially reversible. We previously demonstrated that hyperglycemia activates nuclear factor of activated T cells (NFAT) in conduit and medium-sized resistance arteries and that NFAT blockade abolishes diabetes-driven aggravation of atherosclerosis. In this study, we test whether NFAT plays a role in the development of endothelial dysfunction in diabetes. NFAT-dependent transcriptional activity was elevated in skin microvessels of diabetic Akita (Ins2 +/- ) mice when compared with nondiabetic littermates. Treatment of diabetic mice with the NFAT blocker A-285222 reduced NFATc3 nuclear accumulation and NFAT-luciferase transcriptional activity in skin microvessels, resulting in improved microvascular function, as assessed by laser Doppler imaging and iontophoresis of acetylcholine and localized heating. This improvement was abolished by pretreatment with the nitric oxide (NO) synthase inhibitor l-N G-nitro-l-arginine methyl ester, while iontophoresis of the NO donor sodium nitroprusside eliminated the observed differences. A-285222 treatment enhanced dermis endothelial NO synthase expression and plasma NO levels of diabetic mice. It also prevented induction of inflammatory cytokines interleukin-6 and osteopontin, lowered plasma endothelin-1 and blood pressure, and improved mouse survival without affecting blood glucose. In vivo inhibition of NFAT may represent a novel therapeutic modality to preserve endothelial function in diabetes.

[Effects of butylphthalide on plasma nitric oxide and endothelin-1 in severe elderly OSAHS patients].

Objective:To investigate the effect of butylphthalide on plasma nitric oxide(NO) and endothelin-1(ET-1) in severe elderly OSAHS patients. Method:A total of 120 severe elderly OSAHS patients were chosen by PSG measurement. According to random number table method, OSAHS patients were randomly divided into non-invasive ventilation control group(n=40), butylphthalide treatment group(n=40) and butylphthalide combined with non-invasive ventilation group (n=40). Non-invasive ventilation control group was given double level airway positive pressure ventilation treatment for six months, butylphthalide treatment group accepted oral butylphthalide therapy for six months, butylphthalide combined with non-invasive ventilation group was given double level airway positive pressure ventilation treatment and accepted oral butylphthalide therapy for six months. The changes of plasma NO and ET-1 were detected by immunoenzyme adsorption before treatment and three and six months after treatment. Result:The difference of plasma NO and ET-1 before treatment in the three groups was not statistically significant (P>0.05). Compared with before treatment, the level of plasma NO decreased and the level of plasma ET-1 increased in the three groups after three and six months treatment (P<0.01). Compared with butylphthalide treatment group, the level of plasma NO increased and the level of plasma ET-1 decreased after 3 and 6 months of treatment in both non-invasive ventilation control group and butylphthalide combined with non-invasive ventilation group (P<0.05). Compared with non-invasive ventilation control group, the level of plasma NO increased and the level of plasma ET-1 decreased after 3 and 6 months of treatment in butylphthalide combined with non-invasive ventilation group (P<0.05). Conclusion:Butylphthalide may improve the vascular endothelial function of severe elderly OSAHS patients by increasing the level of NO and decreasing the level of ET-1 in plasma.

Inhaled Nitric Oxide Protects Cerebral Autoregulation and Reduces Hippocampal Necrosis After Traumatic Brain Injury Through Inhibition of ET-1, ERK MAPK and IL-6 Upregulation in Pigs.

OBJECTIVE: Traumatic brain injury (TBI) is an important contributor to morbidity and mortality. Cerebral autoregulation is impaired after TBI, contributing to poor outcome. Extracellular signal-related kinase (ERK) mitogen activated protein kinase (MAPK) and ET-1 are upregulated and contribute to impairment of cerebral autoregulation and histopathology after porcine fluid percussion brain injury (FPI). Recent studies show that inhaled nitric oxide (iNO) prevents impairment of cerebral autoregulation and histopathology after FPI in pigs. Unrelated studies indicated an association between ERK and increased IL-6 after FPI. However, the role of IL-6 in central nervous system (CNS) pathology is not well understood. We investigated whether iNO protects autoregulation and limits histopathology after FPI in pigs due to modulation of brain injury associated upregulation of ET-1, ERK MAPK, and IL-6. METHODS: Lateral FPI was produced in anesthetized pigs equipped with a closed cranial window and iNO administered at 30 min or 2 h post injury. RESULTS: CSF ET-1, ERK MAPK, and IL-6 were increased by FPI, but release was blocked by iNO administered at 30 min or 2 h after TBI. The IL-6 antagonist LMT-28 prevented impairment of cerebral autoregulation and hippocampal CA1 and CA3 neuronal necrosis after FPI. Papaverine induced dilation was unchanged by FPI and LMT-28. Protection lasted for at least 2 h after iNO administration was stopped. CONCLUSIONS: These data indicate that iNO protects cerebral autoregulation and reduces hippocampal necrosis after traumatic brain injury through inhibition of ET-1, ERK MAPK, and IL-6 upregulation in pigs.

Endotelina-1, proteína C reactiva ultrasensible y actividad antioxidante en pacientes con hipotiroidismo subclínico y en eutiroideos con autoinmunidad tiroidea. Efectos del tratamiento con levotiroxina / Endothelin-1, high sensitivity C reactive protein and antioxidant activity in subclinical hypothyroid patients. Effects of levothyroxine treatment

RESUMEN La Endotelina-1 (ET1) y Proteína C Reactiva ultrasensible (PCRus) como marcadores de disfunción endotelial (DE) e inflamación vascular en hipotiroidismo subclínico (HS) han mostrado resultados controvertidos. El rol del estrés oxidativo y defensa antioxidante (TRAP) es motivo de discusión. Objetivos Establecer si el HS y la autoinmunidad tiroidea (AIT), excluyendo otros factores de riesgo cardiovascular, pueden causar DE e inflamación vascular, evaluadas a través de ET1 y PCRus, respectivamente. Establecer si TRAP juega algún rol. Evaluar cambios en ET1 y PCRus luego del tratamiento con levotiroxina (LT4). Material y métodos Se evaluaron prospectivamente 70 pacientes divididos en 3 grupos: HS: 41 pacientes (T4 normal,TSH >4,2 y <10 mUI/L), AIT: 10 pacientes eutiroideos (TSH <4,2 mUI/L) con aTPO y/o aTg (+) y Control: 19 pacientes eutiroideos sin AIT. Se excluyeron otros factores de riesgo cardiovascular. Se midió basalmente ET1, PCRus y TRAP plasmáticos, y en HS bajo LT4 (n = 24): ET1 y PCRus. Resultados No hubo diferencias significativas en edad, IMC, perfil lipídico y TRAP. ET1 y PCRus fueron significativamente mayores en pacientes con HS (media ± DS 1,77 ± 0,85 pg/ml y 1,5 ± 0,6 mg/l vs. controles (0,8 ± 0,3 pg/ml y 0,5 ± 0,2 mg/l) p <0,0001 y <0,008 respectivamente. Del mismo modo en AIT (1,4 ± 0.4 pg/ml y 2,3 ± 1,3 mg/l) vs controles p <0,0001 y <0,034, respectivamente. La TSH fue mayor en el grupo AIT vs. Control 2,57 ± 0,88 vs. 1,64 ± 0,5 mUI/L; p = 0,002. En HS bajo LT4 (8,7 ± 3,8 meses) se observó descenso de ET1 (p <0,001). ET1 correlacionó con TSH (r = 0,5 p <0,0001). El punto de corte de ET1 mediante curva ROC fue 1,32 pg/ml (Sensibilidad 81,6%-Especificidad 75%). Conclusiones ET1 y PCRus resultaron marcadores útiles para evaluar DE e inflamación vascular asociadas a HS. La defensa antioxidante no ejercería un rol en estos mecanismos. El tratamiento con LT4 produjo una significativa caída de ET1, pudiendo necesitarse un período más largo de eutiroidismo para normalizarla. En AIT, niveles de TSH >2,5 mUI/L podrían sugerir un mínimo grado de hipotiroidismo justificando la elevación en ET1 y PCR, sin descartar el rol de la AIT "per se".

ABSTRACT The measurement of endothelin-1 (ET1) and high sensitivity C-reactive protein (hsCRP) as markers of endothelial dysfunction (ED) and vascular inflammation in subclinical hypothyroidism (SH) has shown controversial results. The role of oxidative stress and antioxidant defense (TRAP) is a matter of discussion. Objectives To establish if SH and thyroid autoimmunity (TAI), excluding other cardiovascular risk factors, may cause ED and vascular inflammation, evaluated through the measurement of ET1 and hsCRP respectively. To determine if TRAP could have some role. Additionally, changes in these parameters after treatment with levothyroxine (LT4) will be evaluated. Material and methods: 70 patients were prospectively evaluated. They were classified into: SH Group: 41 patients (normal T4, TSH> 4.2 and <10 mIU/L), TAI Group: 10 euthyroid patients (TSH <4.2 mUI/L) with positive aTPO and/or aTg and Control Group: 19 euthyroid patients without TAI. Other cardiovascular risk factors were excluded in patients and controls. Plasma ET1, hsCRP and TRAP were measured basally, and ET1 and hsCRP under LT4 therapy in the HS Group. Results There were no significant differences between the 3 groups in age, BMI, lipids and TRAP. ET1 and hsCRP were significantly higher in patients with SH (mean ± SD 1.77 ± 0.85 pg/ml and 1.5 ± 0.6 mg/l) vs. controls (0.8 ± 0.3 pg/ml y 0.5 ± 0.2 mg/l) p <0.0001 y <0.008 respectively. Similarly, in TAI patients (1.4 ± 0.4 pg/ml y 2.3 ± 1.3 mg/l) vs controls, p <0.0001 and <0.034, respectively. TSH was higher in the TAI patients versus control group (2.5 ± 0.88 versus 1.64 ± 0.5 mIU/L, p = 0.002). Twenty-four patients with SH showed a significant decrease in ET1 (p <0.001) under treatment with LT4 (8.7 ± 3.8 months). ET1 had a highly significant correlation (p <0.0001) with TSH (r = 0.5). The cut-off level of ET1 established by ROC curve was 1.32 pg/ml (Sensitivity 81.6%-Specificity 75%). Conclusions ET1 and hsCRP were useful markers to evaluate ED and vascular inflammation associated with SH. There were no differences in TRAP levels between patients and controls, so it does not appear that oxidative stress would have played any role. Treatment with LT4 produced a significant drop in ET1. Probably, a longer period of euthyroidism might be necessary to normalize ET1 levels. In TAI Group, TSH levels >2.5 mUI/L could suggest a "minimal degree" of hypothyroidism justifying the elevation in ET1 and hs CRP. The role of the TAI "per se" couldn't be completely ruled out.

Curcumin exerts anti-inflammatory and vasoprotective effects through amelioration of NFAT-dependent endothelin-1 production in mice with acute Chagas cardiomyopathy.

BACKGROUND: The anti-inflammatory and cardioprotective properties of curcumin (Cur), a natural polyphenolic flavonoid isolated from the rhizomes of Curcuma longa, are increasingly considered to have beneficial effects on the progression of Chagas heart disease, caused by the protozoan parasite Trypanosoma cruzi. OBJECTIVE: To evaluate the effects of oral therapy with Cur on T. cruzi-mediated cardiovasculopathy in acutely infected mice and analyse the in vitro response of parasite-infected human microvascular endothelial cells treated with this phytochemical. METHODS: Inflammation of heart vessels from Cur-treated and untreated infected mice were analysed by histology, with benznidazole (Bz) as the reference compound. Parasitaemia was monitored by the direct method. Capillary permeability was visualised by Evans-blue assay. Myocardial ET-1, IL-6, and TNF-α mRNA expressions were measured by quantitative reverse transcription polymerase chain reaction (qRT-PCR). Microvascular endothelial HMEC-1 cells were infected in vitro with or without addition of Cur or Bz. Induction of the Ca2+/NFAT pathway was assessed by fluorometry, immunoblotting, and reporter assay. FINDINGS: Oral Cur therapy of recently infected mice reduced inflammatory cell infiltration of myocardial arteries without lowering parasite levels. Compared to that of the phosphate-buffered saline-receiving group, hearts from Cur-treated mice showed significantly decreased vessel inflammation scores (p < 0.001), vascular permeabilities (p < 0.001), and levels of IL-6/TNF-α (p < 0.01) and ET-1 (p < 0.05) mRNA. Moreover, Cur significantly (p < 0.05 for transcript; p < 0.01 for peptide) downregulated ET-1 secretion from infected HMEC-1 cells. Remarkably, Cur addition significantly (p < 0.05 at 27.0 µM) interfered with T. cruzi-dependent activation of the Ca2+/NFATc1 signalling pathway that promotes generation of inflammatory agents in HMEC-1 cells. CONCLUSIONS: Oral treatment with Cur dampens cardiovasculopathy in acute Chagas mice. Cur impairs the Ca2+/NFATc1-regulated release of ET-1 from T. cruzi-infected vascular endothelium. These findings identify new perspectives for exploring the potential of Cur-based interventions to ameliorate Chagas heart disease.

Salvinorin A ameliorates cerebral vasospasm through activation of endothelial nitric oxide synthase in a rat model of subarachnoid hemorrhage.

OBJECTIVE: This study aimed to demonstrate the potential of salvinorin A (SA) for cerebral vasospasm after subarachnoid hemorrhage (SAH) and investigate mechanisms of therapeutic effect using rat SAH model. METHODS: Salvinorin A was injected intraperitoneally, and the neurobehavioral changes were observed at 12 hours, 24 hours, 48 hours, and 72 hours after SAH. Basilar artery was observed by magnetic resonance imaging (MRI). The inner diameter and thickness of basilar artery were measured. The morphological changes and the apoptosis in CA1 area of hippocampus were detected. Endothelin-1 (ET-1) and nitric oxide (NO) levels were detected by ELISA kit. The protein expression of endothelial NO synthase (eNOS) and aquaporin-4 (AQP-4) was determined by Western blot for potential mechanism exploration. RESULTS: Salvinorin A administration could relieve neurological deficits, decrease the neuronal apoptosis, and alleviate the morphological changes in CA1 area of hippocampus. SA alleviated CVS by increasing diameter and decreasing thickness of basilar artery, and such changes were accompanied by the decreased concentration of ET-1 and increased level of NO. Meanwhile, SA increased the expression of eNOS and decreased the expression of AQP-4 protein in the basilar artery and hippocampus. CONCLUSIONS: Salvinorin A attenuated CVS and alleviated brain injury after SAH via increasing expression of eNOS and NO content, and decreasing ET-1 concentration and AQP-4 protein expression.

Bradykinin system is involved in endometriosis-related pain through endothelin-1 production.

BACKGROUND: Endometriosis is a gynaecological disease exhibiting severe pelvic pain, but the mechanism of pain production remains unknown. Bradykinin (BK) is known as an inflammatory mediator, and shows elevated levels in inflammatory diseases such as rheumatoid arthritis. In the present study, we evaluated whether BK is involved in endometriosis-related pain. METHODS: Endometriotic lesions were used for immunohistochemistry. Primary cultures of endometriotic stromal cells (ESC) were stimulated with IL-1ß and/or BK. Quantitative RT-PCR was used to evaluate the mRNA expressions of BK receptors (BKR) and endothelin-1 in ESC. The concentration of endothelin-1 in cystic fluid of endometrioma or non-endometrioma was measured with ELISA. The conditioned medium of ESC stimulated with IL-1ß and/or BK was injected intraplantarly in mice, and evaluated whether pain-related licking behaviour was elicited. RESULTS: The expressions of BK and BKR in endometriotic lesions were observed by immunohistochemistry. In vitro experiments showed that IL-1ß induced BKR-B1 and B2 on ESC. Activation of these receptors by BK significantly induced endothelin-1 expression in ESC, which was negated completely by HOE-140, a BKR-B2 antagonist. The cystic fluid of endometrioma contained higher amount of endothelin-1 compared to non-endometrioma. Intraplantar injection of the conditioned medium of ESC treated with IL-1ß and BK significantly induced licking behaviour, which was suppressed with BQ-123, an endothelin type-A receptor antagonist. CONCLUSIONS: The present study demonstrated the presence and the function of the BK axis in endometriosis, and established a potential new therapy target for endometriosis-related pain. SIGNIFICANCE: The present study demonstrated (1) the presence and the function of the BK system in endometriosis, (2) activation of BKR induced endothelin-1 in endometriotic lesion and (3) blocking endothelin-1 was effective to decrease pain.

Tanshinone IIA ameliorated endothelial dysfunction in rats with chronic intermittent hypoxia.

Chronic intermittent hypoxia (CIH) during repetitive airflow cessations may cause endothelial dysfunction. Tanshinone IIA (Tan IIA) has been used to treat various circulatory disturbance-related diseases because of its pharmacological actions, including vasodilation. However, the mechanism of the effect of its vasodilation is not well established. The objective of this study was to explore the effect of Tan IIA in endothelium-dependent contracting factors and endothelin receptors in aortic endothelial dysfunction in CIH rats. Aortas of rats were retrieved for use in in vitro experiments (isometric force measurement), histological analysis, immunohistochemistry, and Western blotting. Tan IIA treatment increased the expression of endothelial nitric oxide synthase (eNOS) and formation of nitric oxide (NO), inhibited the production of endothelin-1 (ET-1), down-regulated ETA receptor expression, and up-regulated ETB receptor expression. In conclusion, Tan IIA protects endothelial function by inhibiting strain-induced ET-1 expression, decreasing ETA receptors, increasing ETB receptors, increasing the formation of NO, and up-regulating eNOS in CIH.

Inhalation of methane preserves the epithelial barrier during ischemia and reperfusion in the rat small intestine.

BACKGROUND: Methane is part of the gaseous environment of the intestinal lumen. The purpose of this study was to elucidate the bioactivity of exogenous methane on the intestinal barrier function in an antigen-independent model of acute inflammation. METHODS: Anesthetized rats underwent sham operation or 45-min occlusion of the superior mesenteric artery. A normoxic methane (2.2%)-air mixture was inhaled for 15 min at the end of ischemia and at the beginning of a 60-min or 180-min reperfusion. The integrity of the epithelial barrier of the ileum was assessed by determining the lumen-to-blood clearance of fluorescent dextran, while microvascular permeability changes were detected by the Evans blue technique. Tissue levels of superoxide, nitrotyrosine, myeloperoxidase, and endothelin-1 were measured, the superficial mucosal damage was visualized and quantified, and the serosal microcirculation and mesenteric flow was recorded. Erythrocyte deformability and aggregation were tested in vitro. RESULTS: Reperfusion significantly increased epithelial permeability, worsened macro- and microcirculation, increased the production of proinflammatory mediators, and resulted in a rapid loss of the epithelium. Exogenous normoxic methane inhalation maintained the superficial mucosal structure, decreased epithelial permeability, and improved local microcirculation, with a decrease in reactive oxygen and nitrogen species generation. Both the deformability and aggregation of erythrocytes improved with incubation of methane. CONCLUSION: Normoxic methane decreases the signs of oxidative and nitrosative stress, improves tissue microcirculation, and thus appears to modulate the ischemia-reperfusion-induced epithelial permeability changes. These findings suggest that the administration of exogenous methane may be a useful strategy for maintaining the integrity of the mucosa sustaining an oxido-reductive attack.

Chronic Nebivolol Treatment Suppresses Endothelin-1-Mediated Vasoconstrictor Tone in Adults With Elevated Blood Pressure.

UNLABELLED: Endothelin-1 (ET-1) plays a major role in the pathophysiology of hypertension and its associated cardiovascular risk. We tested the hypothesis that chronic nebivolol treatment reduces ET-1-mediated vasoconstrictor tone in adult humans with elevated blood pressure (BP). Furthermore, reducing ET-1 vasoconstrictor activity contributes to the improvement in endothelial vasodilator function associated with nebivolol treatment. Forty-two middle-aged adults with elevated BP (systolic BP ≥130 mm Hg or diastolic BP ≥85 mm Hg) completed a 3-month, double-blind, randomized, placebo controlled trial: 14 received nebivolol (8 men/6 women; 5 mg per day); 14 received metoprolol succinate (9 men/5 women; 100 mg per day); and 14 received placebo (9 men/5 women). Forearm blood flow (plethysmography) responses to selective (BQ-123: 100 nmol/min; 60 minutes) and nonselective (BQ-123+BQ-788 [50 nmol/min]; 60 minutes) ET-1 receptor blockade, as well as acetylcholine (4.0, 8.0, and 16.0 µg per 100 mL of tissue per minute) in the absence and presence of nonselective ET-1 receptor blockade were determined before and after each treatment intervention. Forearm blood flow responses to BQ-123 and BQ-123+BQ-788 were similarly and significantly elevated (≈30% and 60%, respectively) from baseline in all 3 groups. Nebivolol, but not metoprolol or placebo, therapy resulted in a marked (≈25% and 45%; P<0.05) reduction in forearm blood flow response to BQ-123 and BQ-123+BQ-788. Moreover, after nebivolol therapy only, vasodilator response to acetylcholine was not significantly increased by ET-1 receptor blockade. These results demonstrate that nebivolol, but not metoprolol, treatment reduces ET-1-mediated vasoconstrictor tone in adult humans with elevated BP. In addition, nebivolol-induced reduction in ET-1-mediated vasoconstrictor tone underlies the favorable effects of this ß-blocker on endothelial vasodilation. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01395329.

Vascular effects of simvastatin are similar to hormone replacement therapy in postmenopausal women.

Aim of the study: To compare effect of six month transdermal 17 ß-estradiol supplementation with oral medroxyprogresterone acetate to oral simvastatin treatment on nitric oxide (NO), endothelin-1, ß-thromboglobulin, vascular endothelial growth factor (VEGF) and von Willebrand factor (vWF) levels during standard exercise test in post menopausal women. Patients and Methods: 32 women were included to the study. Group 1 treated with 17ß-estradiol combined with medroxyprogesterone. Group 2 treated with simvastatin, group 3 was the controls. VEGF plasma levels as well as basal and standard exercise test induced levels of vWF, NO, endothelin- 1, ß-thromboglobulin were measured at the beginning of the study, at 3rd and 6th month of the study. During standard exercise test these parameters were measured three times: at the beginning, at peak exercise and at the 15th minute of recovery. Results: 17ß-estradiol supplementation and simvastatin treatment reduced basal and exercise test induced endothelin-1 plasma level. 17ß-estradiol supplementation gradually increased NO release, whereas simvastatin initially reduced and finally increased nitric oxide release. NO/ET-1 ratio was increased at peak exercise and recovery time in group 1 whereas only at peak exercise in group 2. Basal VEGF plasma level and ß-thromboglobulin level at recovery time were reduced after 6 month of simvastatin therapy. Conclusion: Six months long oral simvastatin exerted beneficial influence on endothelial function equal to that of continuous transdermal 17ß-estradiol supplementation combined with medroxyprogesterone acetate. Simvastatin only exerted benefical effect on platelet function. The protective effect of both therapies was more pronounced during exercise and recovery time.

The effects of mycophenolate mofetil on cytokines and their receptors in pulmonary arterial hypertension in rats.

OBJECTIVES: To analyse the effects of mycophenolate mofetil (MMF) on pulmonary artery pressure (PAP) and the expression of cytokines and their receptors in a rat model of pulmonary arterial hypertension (PAH). METHOD: Thirty-eight healthy male inbred Sprague-Dawley rats were divided randomly into four groups: a control group, a monocrotaline (MCT) group, an MMF20 group (MCT+20 mg/kg/day MMF), and an MMF40 group (MCT+40 mg/kg/day MMF). Systolic PAP (SPAP), the right ventricular hypertrophy index (RVI), and the levels of expression of cytokines and their receptors were measured and analysed. RESULTS: SPAP, RVI, levels of expression of basic fibroblast growth factor (bFGF) in serum and lung homogenates, alveolar arterial wall thickness, and the number of muscular arteries in the MMF20 and MMF40 groups were decreased in comparison with the MCT group. CONCLUSIONS: MMF inhibits the formation of vascular muscle and decreases SPAP and RVI by inhibition of the expression of bFGF, endothelin-1 (ET-1), and their receptors, resulting in the inhibition of smooth muscle proliferation and amelioration of PAH.

Histone Methyltransferase SET1 Mediates Angiotensin II-Induced Endothelin-1 Transcription and Cardiac Hypertrophy in Mice.

OBJECTIVE: Endothelin-1 is a potent vasoconstrictor derived from vascular endothelium. Elevated endothelin-1 levels are observed in a host of cardiovascular pathologies including cardiomyopathy. The epigenetic mechanism responsible for endothelin-1 induction in these pathological processes remains elusive. APPROACH AND RESULTS: We report here that induction of endothelin-1 expression in endothelial cells by angiotensin II (Ang II) was accompanied by the accumulation of histone H3K4 trimethylation, a preeminent histone modification for transcriptional activation, on the endothelin-1 promoter. In the meantime, Ang II stimulated the expression and the occupancy of Suv, Ez, and Trithorax domain 1 (SET1), a mammalian histone H3K4 trimethyltransferase, on the endothelin-1 promoter, both in vitro and in vivo. SET1 was recruited to the endothelin-1 promoter by activating protein 1 (c-Jun/c-Fos) and synergized with activating protein 1 to activate endothelin-1 transcription in response to Ang II treatment. Knockdown of SET1 in endothelial cells blocked Ang II-induced endothelin-1 synthesis and abrogated hypertrophy of cultured cardiomyocyte. Finally, endothelial-specific depletion of SET1 in mice attenuated Ang II-induced pathological hypertrophy and cardiac fibrosis. CONCLUSIONS: Our data suggest that SET1 epigenetically activates endothelin-1 transcription in endothelial cells, thereby contributing to Ang II-induced cardiac hypertrophy. As such, screening of small-molecule compound that inhibits SET1 activity will likely offer a new therapeutic solution to the treatment of cardiomyopathy.

Bupivacaine inhibits endothelin-1-evoked increases in intracellular calcium in model sensory neurons.

BACKGROUND: Endothelin-1 (ET-1) induces pain-like behavior in animals and man by activating the Gq protein-coupled receptor endothelin-A (ETA ). Activation of ETA receptors on nociceptor membranes evokes intracellular calcium transients and alters membrane Na(+) and K(+) channel and TRPV1 currents, leading to neuronal hyper-excitability manifested by spontaneous and evoked pain behaviors in vivo. In addition to blocking sodium channels, local anesthetics inhibit the Gq protein-coupled signaling of several inflammatory and pro-algesic mediators. In this study, we aimed to investigate the actions of local anesthetics on ETA -mediated increases in intracellular calcium in ND7/104 model sensory neurons. METHODS: Increases in intracellular calcium were measured by the fluorescent indicator fura-2 in a sensory neuron-derived cell line (ND7/104), which endogenously expresses ETA receptors. Effects of lidocaine and bupivacaine, along with their respective membrane-impermeant derivatives QX-314, LEA-123 and LEA-124, on peak calcium responses to ET-1 were measured. RESULTS: Bupivacaine suppressed ET-1 responses in a concentration-dependent and non-competitive manner with an IC50 of 3.79 ± 1.63 mM. Bupivacaine (6 mM) reduced the Emax for ET-1 from 50.07 ± 1.91 mM to 27.30 ± 2.92 mM. The actions of bupivacaine occurred quickly and were rapidly reversible. Membrane-impermeant analogs of bupivacaine (LEA-123 and LEA-124, 6 mM) were without effect, as was lidocaine (10 mM) and its quaternary derivative QX-314 (10 mM). CONCLUSION: Bupivacaine inhibits ETA -mediated calcium transients at clinically relevant concentrations through an intracellular target. The anti-inflammatory and analgesic actions of bupivacaine may be at least partially due to its inhibitory action on Gq -coupled receptors, including ETA.

Modulation of Calcium Signaling of Angiotensin AT1, Endothelin ETA, and ETB Receptors by Silibinin, Quercetin, Crocin, Diallyl Sulfides, and Ginsenoside Rb1.

Angiotensin II and endothelin-1 are potent vasoconstrictive peptides that play a central role in blood pressure regulation. Both peptides exert their pleiotropic effects via binding to their respective G-protein-coupled receptors, i.e., angiotensin AT1 and endothelin type A and type B receptors. In the present study, we have selected six structurally different plant-derived compounds with known cardioprotective properties to evaluate their ability to modulate calcium signaling of the above-mentioned receptors. For this purpose, we used and validated a cellular luminescence-based read-out system in which we measured intracellular calcium signaling in Chinese hamster ovary cells that express the calcium sensitive apo-aequorin protein. Firstly, silibinin, a flavanolignan that occurs in milk thistle (Silybum marianum), was investigated and found to be an antagonist for the human angiotensin AT1 receptor with an affinity constant of about 9 µM, while it had no effect on endothelin type A or type B receptor activation. Quercetin and crocin partially impeded intracellular calcium signaling resulting in a non-receptor-related reduction of the responses recorded for the three investigated G-protein-coupled receptors. Two organosulfur compounds, diallyl disulfide and diallyl trisulfide, as well as the triterpene saponin ginsenoside Rb1 did not affect the activation of the angiotensin AT1 and endothelin type A and type B receptors. In conclusion, we were able, by using a nonradioactive cellular read-out system, to identify a novel pharmacological property of the flavanolignan silibinin.

Effects of recombinant human erythropoietin on resistance artery endothelial function in stage 4 chronic kidney disease.

BACKGROUND: Recent studies have raised concern about the safety of erythropoiesis-stimulating agents because of evidence of increased risk of hypertension and cardiovascular morbidity and mortality in chronic kidney disease (CKD) patients. In the present study, we investigated the effects of recombinant human erythropoietin (EPO) on endothelial function of gluteal subcutaneous resistance arteries isolated from 17 stage 4 patients (estimated glomerular filtration rate 21.9±7.4 mL/min per 1.73 m(2)) aged 63±13 years. METHODS AND RESULTS: Arteries were mounted on a pressurized myograph. EPO impaired endothelium-dependent relaxation in a concentration-dependent manner. The maximal response to acetylcholine with EPO at 1, 10, and 20 IU/mL was reduced by 12%, 34%, and 43%, respectively, compared with the absence of EPO (P<0.001). EPO-induced endothelial dysfunction was significantly associated with carotid stiffness and history of cardiovascular events. EPO had no effect on norepinephrine-induced vasoconstriction or sodium nitroprusside-induced relaxation. ABT-627, an endothelin type A receptor antagonist, and tempol, a superoxide dismutase mimetic, partially reversed the altered endothelial function in the presence of EPO (P<0.01). Increased expression of endothelin-1 was found in the vessel wall after incubation with EPO. CONCLUSIONS: EPO alters endothelial function of resistance arteries in CKD patients via a mechanism involving in part oxidative stress and signaling through an endothelin type A receptor. EPO-induced endothelial dysfunction could contribute to deleterious effects of EPO described in large interventional trials.

Effect of perindopril on pulse-wave velocity and endothelin-1 in black hypertensive patients.

INTRODUCTION: We investigated the effect of perindopril on pulse-wave velocity (as indicator of arterial elasticity) and endothelin-1 (ET-1) levels in black hypertensive patients. METHODS: Forty-four newly diagnosed hypertensive patients who received 4 mg perindopril daily were monitored for nine months. Pulse-wave velocity (PWV) was measured noninvasively along the carotid-femoral arterial segment (high elastic content) and the brachial-ulnar segment (low elastic content). RESULTS: There was a significant increase in arterial elasticity, as indicated by a slower PWV in the carotid-femoral segment of the treatment group, from 11.6 to 7.5 m/s after nine months. The PWV of the treatment group (7.5 m/s) after nine months was lower than that of the healthy volunteer group (8.2 m/s) but it was not statistically significant. No correlation between ET-1 and PWV could be found. CONCLUSION: In addition to its blood pressure-lowering effect, our study confirmed the improvement in arterial elasticity in patients on perindopril therapy, without involvement of ET-1.