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1.
Curr Vasc Pharmacol ; 21(4): 246-256, 2023.
Article in English | MEDLINE | ID: mdl-37349999

ABSTRACT

BACKGROUND: We previously reported that endothelins (ETs) regulate tyrosine hydroxylase (TH) activity and expression in the olfactory bulb (OB) of normotensive and hypertensive animals. Applying an ET receptor type A (ETA) antagonist to the brain suggested that endogenous ETs bind to ET receptor type B (ETB) to elicit effects. OBJECTIVE: The aim of the present work was to evaluate the role of central ETB stimulation on the regulation of blood pressure (BP) and the catecholaminergic system in the OB of deoxycorticosterone acetate (DOCA)-salt hypertensive rats. METHODS: DOCA-salt hypertensive rats were infused for 7 days with cerebrospinal fluid or IRL-1620 (ETB receptor agonist) through a cannula placed in the lateral brain ventricle. Systolic BP (SBP) and heart rate were recorded by plethysmography. The expression of TH and its phosphorylated forms in the OB were determined by immunoblotting, TH activity by a radioenzymatic assay, and TH mRNA by quantitative real-time polymerase chain reaction. RESULTS: Chronic administration of IRL-1620 decreased SBP in hypertensive rats but not in normotensive animals. Furthermore, the blockade of ETB receptors also decreased TH-mRNA in DOCA-salt rats, but it did not modify TH activity or protein expression. CONCLUSION: These findings suggest that brain ETs through the activation of ETB receptors contribute to SBP regulation in DOCA-salt hypertension. However, the catecholaminergic system in the OB does not appear to be conclusively involved although mRNA TH was reduced. Present and previous findings suggest that in this salt-sensitive animal model of hypertension, the OB contributes to chronic BP elevation.


Subject(s)
Desoxycorticosterone Acetate , Hypertension , Rats , Animals , Desoxycorticosterone Acetate/pharmacology , Tyrosine 3-Monooxygenase/metabolism , Tyrosine 3-Monooxygenase/pharmacology , Olfactory Bulb/metabolism , Hypertension/chemically induced , Hypertension/metabolism , Blood Pressure , Endothelins/metabolism , Endothelins/pharmacology , Receptor, Endothelin B/genetics , Receptor, Endothelin B/metabolism , RNA, Messenger/metabolism , Endothelin-1/genetics , Endothelin-1/metabolism , Endothelin-1/pharmacology , Receptor, Endothelin A/genetics , Receptor, Endothelin A/metabolism
2.
Oncol Rep ; 46(2)2021 Aug.
Article in English | MEDLINE | ID: mdl-34165174

ABSTRACT

Endothelin­1 (ET­1) is involved in the regulation of steroidogenesis. Additionally, patients with castration­resistant prostate cancer (PCa) have a higher ET­1 plasma concentration than those with localized PCa and healthy individuals. The aim of the present study was to evaluate the effect of ET­1 on steroidogenesis enzymes, androgen receptor (AR) and testosterone (T) production in PCa cells. The expression levels of endothelin receptors in prostate tissue from patients with localized PCa by immunohistochemistry, and those in LNCaP and PC3 cells were determined reverse transcription­quantitative PCR (RT­qPCR) and western blotting. Furthermore, the expression levels of ET­1 were determined in LNCaP and PC3 cells by RT­qPCR and western blotting. The ET­1 receptor activation was evaluated by intracellular calcium measurement, the expression levels of AR and enzymes participating in steroidogenesis [cytochrome P450 family 11 subfamily A member 1 (CyP11A1), cytochrome P450 family 17 subfamily A member 1, aldo­keto reductase family member C2 and 3ß­hydroxysteroid dehydrogenase/isomerase 2 (3ß HSD2)] were determined by western blotting and T concentration was determined by ELISA using PC3 cells. The present results revealed higher expression levels of endothelin A receptor (ETAR) in tissues obtained from samples of patients with PCa with a low Gleason Score. No changes were identified for endothelin B receptor (ETBR). PC3 cells expressed higher levels of ET­1 and ETAR, while LNCaP cells exhibited higher expression levels of ETBR. Blocking of ETAR and endothelin B receptor decreased the expression levels of CyP11A1 and 3ß HSD2 enzymes and AR in PC3 cells, as well as T secretion. These findings suggested that ET­1 has a potential role in modulating the intratumoral steroidogenesis pathway and might have relevance as a possible therapeutic target.


Subject(s)
Endothelin-1/metabolism , Prostatic Neoplasms/metabolism , Receptor, Endothelin A/metabolism , Receptors, Androgen/genetics , Testosterone/metabolism , 3-Hydroxysteroid Dehydrogenases/metabolism , Aged , Aged, 80 and over , Cell Line, Tumor , Cholesterol Side-Chain Cleavage Enzyme/metabolism , Humans , Male , Middle Aged , Neoplasm Grading , PC-3 Cells , Prostatic Neoplasms/genetics , Prostatic Neoplasms/pathology , Receptor, Endothelin B/metabolism , Tissue Array Analysis , Up-Regulation
3.
Neurotox Res ; 36(4): 688-699, 2019 Nov.
Article in English | MEDLINE | ID: mdl-31228092

ABSTRACT

The aim of this study was to evaluate the participation of the endothelin ETA and ETB receptors and the effects of bosentan in oxaliplatin-induced peripheral sensory neuropathy (OIN) in mice. Adult male Swiss mice received 1 mg/kg of oxaliplatin intravenously, twice a week for 5 weeks. Dorsal root ganglia (DRG) and spinal cords were removed for evaluation of the endothelin ETA and ETB receptor expression. Afterwards, selective (BQ-123 and BQ-788; 10 nmol in 30 µL, intraplantarly) and non-selective (bosentan, 100 mg/kg, orally) antagonists were administered in order to evaluate the involvement of the endothelin receptors in OIN. Mechanical and thermal nociception tests were performed once a week for 56 days. Oxaliplatin induced mechanical and thermal hypersensitivity and increased the endothelin ETA receptor expression in both the DRG and spinal cord (P < 0.05). Endothelin ETB receptor expression was increased in the DRG (P < 0.05) but not in the spinal cord. Both endothelin ETA and ETB receptor selective antagonists partially prevented mechanical hyperalgesia in mice with OIN (P < 0.05). Moreover, bosentan prevented mechanical and thermal hypersensitivity in oxaliplatin-treated mice (P < 0.05). In conclusion, both endothelin ETA and ETB receptors seem to be involved in the OIN in mice and they should be considered possible targets for the management of this clinical feature.


Subject(s)
Oxaliplatin/toxicity , Peripheral Nervous System Diseases/chemically induced , Receptor, Endothelin A/metabolism , Receptor, Endothelin B/metabolism , Animals , Bosentan/administration & dosage , Endothelin Receptor Antagonists , Ganglia, Spinal/drug effects , Ganglia, Spinal/metabolism , Hyperalgesia/chemically induced , Hyperalgesia/drug therapy , Male , Mice , Peripheral Nervous System Diseases/metabolism , Spinal Cord Dorsal Horn/drug effects , Spinal Cord Dorsal Horn/metabolism
4.
Mol Cell Endocrinol ; 493: 110455, 2019 08 01.
Article in English | MEDLINE | ID: mdl-31145933

ABSTRACT

Although studies have provided significant evidence about the role of RAS in mediating cancer risk in type 2 diabetes mellitus (DM), conclusions about the central molecular mechanisms underlying this disease remain to be reached, because this type of information requires an integrative multi-omics approach. In the current study, meta-analysis was performed on type 2 diabetes and breast, bladder, liver, pancreas, colon and rectum cancer-associated transcriptome data, and reporter biomolecules were identified at RNA, protein, and metabolite levels using the integration of gene expression profiles with genome-scale biomolecular networks in diabetes samples. This approach revealed that RAS biomarkers could be associated with cancer initiation and progression, which include metabolites (particularly, aminoacyl-tRNA biosynthesis and ABC transporters) as novel biomarker candidates and potential therapeutic targets. We detected downregulation and upregulation of differentially expressed genes (DEGs) in blood, pancreatic islets, liver and skeletal muscle from normal and diabetic patients. DEGs were combined with 211 renin-angiotensin-system related genes. Upregulated genes were enriched using Pathway analysis of cancer in pancreatic islets, blood and skeletal muscle samples. It seems that the changes in mRNA are contributing to the phenotypic changes in carcinogenesis, or that they are as a result of the phenotypic changes associated with the malignant transformation. Our analyses showed that Ctsg and Ednrb are downregulated in cancer samples. However, by immunohistochemistry experiments we observed that EDNRB protein showed increased expression in tumor samples. It is true that alterations in mRNA expression do not always reflect alterations in protein expression, since post-translational changes can occur in proteins. In this study, we report valuable data for further experimental and clinical analysis, because the proposed biomolecules have significant potential as systems biomarkers for screening or for therapeutic purposes in type 2 diabetes and cancer-associated pathways.


Subject(s)
Diabetes Mellitus, Type 2/genetics , Gene Expression Profiling/methods , Neoplasms/genetics , Renin-Angiotensin System , Cathepsin G/genetics , Cathepsin G/metabolism , Diabetes Mellitus, Type 2/metabolism , Female , Gene Expression Regulation , Gene Regulatory Networks , Humans , Meta-Analysis as Topic , Metabolomics , Neoplasms/metabolism , Organ Specificity , Protein Interaction Maps , Proteomics , Receptor, Endothelin B/genetics , Receptor, Endothelin B/metabolism
5.
Nephrol Dial Transplant ; 34(5): 794-801, 2019 05 01.
Article in English | MEDLINE | ID: mdl-30107561

ABSTRACT

BACKGROUND: Acute kidney injury (AKI) is not as harmless as previously thought since it may lead to chronic kidney disease (CKD). Because most of the time ischemic AKI occurs unexpectedly, it is difficult to prevent its occurrence and there are no specific therapeutic approaches to prevent the AKI to CKD transition. We aimed to determine whether mineralocorticoid receptor blockade (MRB) in the first days after ischemia/reperfusion (IR) can prevent progression to CKD. METHODS: Four groups of male Wistar rats were included: sham and three groups of bilateral renal ischemia for 45 min, one without treatment and the other two receiving spironolactone for 5 or 10 days, starting 24 h after IR. The rats were studied at 10 days or 5 months after ischemia induction. RESULTS: After 5 months of follow-up, the untreated group exhibited clear evidence of AKI to CKD progression, such as proteinuria, reduced renal blood flow, tubulointerstitial fibrosis, glomerulosclerosis and glomerular hypertrophy. All these alterations were prevented by both spironolactone treatments initiated 24 h after IR, the 10-day treatment being more effective. Within the early mechanisms of the MRB protective effect are the reduction of inflammation and increased endothelin-B-receptor expression and endothelial nitric oxide synthase activation in the first 10 days after IR. CONCLUSIONS: We propose that MRB, administered 24 h after the ischemic injury that leads to AKI, reduces inflammation and promotes efficient tissue repair that avoids the AKI to CKD transition. These data highlight a therapeutic window to preclude CKD development after AKI.


Subject(s)
Acute Kidney Injury/drug therapy , Inflammation/metabolism , Kidney/pathology , Receptor, Endothelin B/metabolism , Renal Insufficiency, Chronic/prevention & control , Spironolactone/administration & dosage , Acute Kidney Injury/metabolism , Acute Kidney Injury/pathology , Animals , Delayed-Action Preparations , Disease Models, Animal , Disease Progression , Inflammation/pathology , Kidney/metabolism , Male , Mineralocorticoid Receptor Antagonists/administration & dosage , Rats , Rats, Wistar , Renal Insufficiency, Chronic/metabolism , Renal Insufficiency, Chronic/pathology
6.
Pflugers Arch ; 470(12): 1815-1827, 2018 12.
Article in English | MEDLINE | ID: mdl-30094478

ABSTRACT

Complex regional pain syndrome (CRPS) is a disorder that involves abnormal inflammation and nerve dysfunction frequently resistant to a broad range of treatments. Peripheral nerve stimulation with electroacupuncture (EA) has been widely used in different clinical conditions to control pain and inflammation; however, the use of EA in the treatment of CRPS is under investigation. In this study, we explore the effects of EA on hyperalgesia and edema induced in an animal model of chronic post-ischemia pain (CPIP model) and the possible involvement of endothelin receptor type B (ETB) in this effect. Female Swiss mice were subjected to 3 h hind paw ischemia/reperfusion CPIP model. EA treatment produced time-dependent inhibition of mechanical and cold hyperalgesia, as well as edema in CPIP mice. Peripheral administration (i.pl.) of BQ-788 (10 nmol), an ETB antagonist, prevented EA-induced antihyperalgesia while intrathecal administration prolonged EA's effect. Additionally, peripheral pre-treatment with sarafotoxin (SRTX S6c, 30 pmol, ETB agonist) increased EA anti-hyperalgesic effect. Furthermore, the expression of peripheral ETB receptors was increased after EA treatments, as measured by western blot. These results may suggest that EA's analgesic effect is synergic with ETB receptor activation in the periphery, as well as central (spinal cord) ETB receptor blockade. These data support the use of EA as a nonpharmacological approach for the management of CRPS-I, in an adjuvant manner to ETB receptor targeting drugs.


Subject(s)
Complex Regional Pain Syndromes/therapy , Electroacupuncture/methods , Hyperalgesia/therapy , Receptor, Endothelin B/metabolism , Animals , Complex Regional Pain Syndromes/metabolism , Endothelin B Receptor Antagonists/administration & dosage , Endothelin B Receptor Antagonists/pharmacology , Female , Hyperalgesia/metabolism , Mice , Oligopeptides/administration & dosage , Oligopeptides/pharmacology , Peripheral Nerves/drug effects , Piperidines/administration & dosage , Piperidines/pharmacology , Receptor, Endothelin B/agonists , Spinal Cord/drug effects , Viper Venoms/administration & dosage , Viper Venoms/pharmacology
7.
Curr Hypertens Rev ; 13(1): 33-40, 2017.
Article in English | MEDLINE | ID: mdl-28413991

ABSTRACT

Early vascular aging is a process associated with gradual alterations in the vessels, regarding their structure and function, taking a more rapid course than normal biological aging in the arteries. In the presence of cardiovascular disease, these age-associated alterations are accelerated, contributing in the appearance or the progression of cardiovascular disease, such as high blood pressure, dyslipidemia, smoking and diabetes. Endothelin-1 (ET-1) is the most abundant and important endothelin produced by vascular cells. ET-1 exerts its biological actions through the activation of two receptors: ETA and ETB. Many important functions are mediated by the activation of these receptors, such as cardiovascular remodeling, vasoconstriction, cell proliferation and differentiation, production of extracellular matrix, and water and sodium secretion control. ETA receptor seems to participate in the pathogenesis and development of diseases, such as diabetes, atherosclerosis, systemic and pulmonary hypertension, and cardiac remodeling after myocardial ischemia, whereas ETB receptor seems to prevent the overstimulation of ETA receptor, acting as a clearance receptor. Increased ET-1 system activity may contribute to vascular dysfunction in aging via multiple pathways, such as direct hemodynamic effects, vascular oxidative stress, inflammatory activity, mitogenic stimulation of the vascular smooth muscle cells and fibrotic processes. Endothelin receptor antagonists were considered to be used for the treatment of some diseases like hypertension, diabetes and chronic kidney disease. However, besides pulmonary hypertension, this class is not in clinical use because of the side effects and the availability of safer drugs for the treatment of these diseases.


Subject(s)
Aging/physiology , Blood Vessels/physiopathology , Endothelin Receptor Antagonists/therapeutic use , Endothelin-1/physiology , Hypertension/drug therapy , Blood Vessels/pathology , Cardiovascular Diseases/etiology , Disease Progression , Endothelins/physiology , Humans , Hypertension/etiology , Hypertension, Pulmonary/drug therapy , Hypertension, Pulmonary/etiology , Muscle, Smooth, Vascular , Receptor, Endothelin A/metabolism , Receptor, Endothelin B/metabolism , Vasoconstriction/physiology
8.
Exp Physiol ; 100(6): 617-27, 2015 Jun.
Article in English | MEDLINE | ID: mdl-25809871

ABSTRACT

NEW FINDINGS: What is the central question of this study? Does ex vivo administration of endothelin-1 and endothelin-3 regulate noradrenergic transmission in the posterior hypothalamus of deoxycorticosterone acetate-salt hypertensive rats compared with normotensive rats? What is the main finding and its importance? Endothelin-1 and endothelin-3 enhanced diverse mechanisms leading to increased noradrenergic transmission in the posterior hypothalamus of deoxycorticosterone acetate-salt hypertensive rats. Unveiling the role of brain endothelins in hypertension would probably favour the development of new therapeutic targets for the treatment of essential hypertension, which still represents a challenging disease with high mortality. Brain catecholamines participate in diverse biological functions regulated by the hypothalamus. We have previously reported that endothelin-1 and endothelin-3 (ET-1 and ET-3) modulate catecholaminergic activity in the anterior and posterior hypothalamus of normotensive rats. The aim of the present study was to evaluate the interaction between endothelins and noradrenergic transmission in the posterior hypothalamus of deoxycorticosterone acetate (DOCA)-salt hypertensive rats. We assessed the effects of ET-1 and ET-3 on tyrosine hydroxylase activity and expression, neuronal noradrenaline (NA) release, neuronal NA transporter (NAT) activity and expression, monoamine oxidase activity and NA endogenous content and utilization (as a marker of turnover) in the posterior hypothalamus of DOCA-salt hypertensive rats. In addition, levels of ETA and ETB receptors were assayed in normotensive and hypertensive rats. Results showed that tyrosine hydroxylase activity and total and phosphorylated levels, NAT activity and content, NA release, monoamine oxidase activity and NA utilization were increased in DOCA-salt rats. Both ET-1 and ET-3 further enhanced all noradrenergic parameters except for total tyrosine hydroxylase level and NA endogenous content and utilization. The expression of ETA receptors was increased in the posterior hypothalamus of DOCA-salt rats, but ETB receptors showed no changes. These results show that ET-1 and ET-3 upregulate noradrenergic activity in the posterior hypothalamus of DOCA-salt hypertensive rats. Our findings suggest that the interaction between noradrenergic transmission and the endothelinergic system in the posterior hypothalamus may be involved in the development and/or maintenance of hypertension in this animal model.


Subject(s)
Adrenergic Neurons/drug effects , Desoxycorticosterone Acetate , Endothelin-1/administration & dosage , Endothelin-3/administration & dosage , Hypertension/metabolism , Hypothalamus, Posterior/drug effects , Norepinephrine/metabolism , Sodium Chloride, Dietary , Synaptic Transmission/drug effects , Adrenergic Neurons/metabolism , Animals , Blood Pressure/drug effects , Disease Models, Animal , Hypertension/chemically induced , Hypertension/physiopathology , Hypothalamus, Posterior/metabolism , Hypothalamus, Posterior/physiopathology , Male , Monoamine Oxidase/metabolism , Norepinephrine Plasma Membrane Transport Proteins/metabolism , Phosphorylation , Rats, Sprague-Dawley , Receptor, Endothelin A/drug effects , Receptor, Endothelin A/metabolism , Receptor, Endothelin B/drug effects , Receptor, Endothelin B/metabolism , Tyrosine 3-Monooxygenase/metabolism
9.
Clin Sci (Lond) ; 125(11): 521-32, 2013 Dec.
Article in English | MEDLINE | ID: mdl-23642207

ABSTRACT

We have reported previously that centrally applied ET (endothelin)-1 and ET-3 induce either choleresis or cholestasis depending on the dose. In the present study, we sought to establish the role of these endothelins in the short-term peripheral regulation of bile secretion in the rat. Intravenously infused endothelins induced significant choleresis in a dose-dependent fashion, ET-1 being more potent than ET-3. Endothelins (with the exception of a higher dose of ET-1) did not affect BP (blood pressure), portal venous pressure or portal blood flow. ET-1 and ET-3 augmented the biliary excretion of bile salts, glutathione and electrolytes, suggesting enhanced bile acid-dependent and -independent bile flows. ET-induced choleresis was mediated by ET(B) receptors coupled to NO and inhibited by truncal vagotomy, atropine administration and capsaicin perivagal application, supporting the participation of vagovagal reflexes. RT (reverse transcription)-PCR and Western blot analysis revealed ETA and ET(B) receptor expression in the vagus nerve. Endothelins, through ET(B) receptors, augmented the hepatocyte plasma membrane expression of Ntcp (Na⁺/taurocholate co-transporting polypeptide; Slc10a1), Bsep (bile-salt export pump; Abcb11), Mrp2 (multidrug resistance protein-2; Abcc2) and Aqp8 (aquaporin 8). Endothelins also increased the mRNAs of these transporters. ET-1 and ET-3 induced choleresis mediated by ET(B) receptors coupled to NO release and vagovagal reflexes without involving haemodynamic changes. Endothelin-induced choleresis seems to be caused by increased plasma membrane translocation and transcriptional expression of key bile transporters. These findings indicate that endothelins are able to elicit haemodynamic-independent biological effects in the liver and suggest that these peptides may play a beneficial role in pathophysiological situations where bile secretion is impaired.


Subject(s)
Cholestasis/chemically induced , Endothelin-1/pharmacology , Endothelin-3/pharmacology , Nitric Oxide/physiology , Receptor, Endothelin B/physiology , Vagus Nerve/drug effects , Animals , Bile/metabolism , Blood Pressure/drug effects , Cholagogues and Choleretics/pharmacology , Cholestasis/metabolism , Hemodynamics/drug effects , Nitric Oxide/metabolism , Rats , Rats, Sprague-Dawley , Receptor, Endothelin B/metabolism , Reflex/drug effects , Regional Blood Flow/drug effects , Vagotomy , Vagus Nerve/metabolism , Vagus Nerve/physiology
10.
Rev. bras. cir. cardiovasc ; Rev. bras. cir. cardiovasc;27(4): 512-519, out.-dez. 2012. ilus, tab
Article in English | LILACS | ID: lil-668112

ABSTRACT

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 ETr-B), nas valvas mitrais reumáticas de 17 pacientes que se submeteram à cirurgia de troca valvar. As amostras também foram submetidas à análise histológica. RESULTADOS: Nossos dados mostraram que praticamente todos os pacientes, independentemente de características individuais, como sexo ou idade, expressaram os genes de receptores de endotelina, porém não expressaram os genes para ET-3. Na análise quantitativa, a média da proporção ETr-A/GAPDH foi de 33,04 ± 18,09%; enquanto que a média da proporção ETr-B/GAPDH foi de 114,58 ± 42,30%. Em relação às características histopatológicas individuais, a frequência de fibrose foi de 100%, infiltrado mononuclear de 88,23%, neovascularização de 52,94%, calcificação de 58,82% e houve ausência de ossificação. CONCLUSÃO: A presença de receptores ETr-A e ETr-B em valvas mitrais reumáticas sugere sua interação com o sistema de endotelinas circulantes, particularmente ETr-B (reconhecido por atuar na remoção do excesso de endotelina), detectado em maior proporção, o que poderia explicar a ausência da expressão de endotelina em valva mitral reumática, processo a ser elucidado.


Subject(s)
Adult , Female , Humans , Male , /genetics , Gene Expression/genetics , Mitral Valve Stenosis/genetics , Receptor, Endothelin A/genetics , Receptor, Endothelin B/genetics , Rheumatic Heart Disease/genetics , /metabolism , Heart Valve Prosthesis Implantation , Mitral Valve Stenosis/surgery , Receptor, Endothelin A/metabolism , Receptor, Endothelin B/metabolism , Rheumatic Heart Disease/metabolism , Rheumatic Heart Disease/surgery
11.
Reprod Toxicol ; 34(4): 598-606, 2012 Dec.
Article in English | MEDLINE | ID: mdl-22975478

ABSTRACT

Previous studies have shown that particulate matter (PM) compromise birth weight and placental morphology. We hypothesized that exposing mice to ambient PM would affect umbilical cord (UC) morphology. To test this, mice were kept in paired open-top exposure chambers at the same location and ambient conditions but, in one chamber, the air was filtered (F) and, in the other, it was not (NF). UCs were analysed stereologically and by immunohistochemistry to localize isoprostane and endothelin receptors. The cords of mice from NF chambers were smaller in volume due to loss of mucoid connective tissue and decrease in volume of collagen. These structural changes and in umbilical vessels were associated with greater volumes of regions immunostained for isoprostane, ET(A)R and ET(B)R. Findings indicate that the adverse effects of PM on birth weight may be mediated in part by alterations in UC structure or imbalances in the endogenous regulators of vascular tone and oxidative stress.


Subject(s)
Air Pollution/adverse effects , Particulate Matter/toxicity , Umbilical Cord/drug effects , Animals , Collagen/metabolism , Female , Immunohistochemistry , Male , Mice , Mice, Inbred BALB C , Pregnancy , Receptor, Endothelin A/metabolism , Receptor, Endothelin B/metabolism , Umbilical Cord/blood supply , Umbilical Cord/metabolism , Umbilical Cord/pathology
12.
Life Sci ; 91(13-14): 628-33, 2012 Oct 15.
Article in English | MEDLINE | ID: mdl-22483687

ABSTRACT

AIMS: To date, suggestions that endothelin-1 (ET-1) causes nociception and pruritus are based on results in preclinical models in which responses to pruritic and nociceptive stimuli cannot be distinguished. This study reexamines these sensory effects of ET-1 in the new mouse cheek model, in which pruritogens and algogens evoke distinct behavioral responses. MAIN METHODS: Mice received intradermal (i.d.) injections of test substances into the left cheek and bouts of hind limb scratches or forepaw wipes, directed to the injection site, were considered indicative of pruritus and nociception, respectively. KEY FINDINGS: Histamine and capsaicin selectively evoked scratching and wipes, respectively, whereas ET-1 (3-60 pmol) promoted dose-dependent bouts of both behaviors. While scratching and wipe responses to ET-1 (30 pmol) were potentiated by BQ-788 (an ET(B) receptor antagonist) and reduced by co-injection of BQ-788 plus BQ-123 (an ET(A) receptor antagonist), BQ-123 alone inhibited scratching responses only. CTOP (µ-opioid receptor selective antagonist) only augmented scratching responses to ET-1, whereas DAMGO (µ-opioid receptor selective agonist) reduced both behaviors. Loratadine (histamine H(1) receptor antagonist) marginally reduced scratching, but markedly suppressed wipes. SIGNIFICANCE: These results demonstrate that ET-1 evokes pruritic and nociceptive behaviors in the mouse cheek model. Both responses to ET-1 appear to be mediated via ET(A) receptors and subjected to limitation by simultaneous ET(B) receptor activation. Local endogenous opioids acting on µ-opioid receptors selectively modulate the pruritic response to ET-1, whereas histamine, possibly derived from mast cells and acting on H(1) receptors, contributes importantly to the nociceptive effect of ET-1 in this model.


Subject(s)
Endothelin-1/metabolism , Pain/physiopathology , Pruritus/physiopathology , Receptor, Endothelin A/metabolism , Animals , Behavior, Animal , Capsaicin/administration & dosage , Cheek , Dose-Response Relationship, Drug , Endothelin A Receptor Antagonists , Endothelin B Receptor Antagonists , Endothelin-1/administration & dosage , Histamine/administration & dosage , Injections, Intradermal , Male , Mice , Pain/etiology , Pruritus/etiology , Receptor, Endothelin A/agonists , Receptor, Endothelin B/agonists , Receptor, Endothelin B/metabolism , Receptors, Histamine H1/drug effects , Receptors, Histamine H1/metabolism , Receptors, Opioid, mu/agonists , Receptors, Opioid, mu/antagonists & inhibitors , Receptors, Opioid, mu/metabolism
13.
Can J Physiol Pharmacol ; 90(2): 187-99, 2012 Feb.
Article in English | MEDLINE | ID: mdl-22320712

ABSTRACT

Endothelin mediates neutrophil recruitment during innate inflammation. Herein we address whether endothelin-1 (ET-1) is involved in neutrophil recruitment in adaptive inflammation in mice, and its mechanisms. Pharmacological treatments were used to determine the role of endothelin in neutrophil recruitment to the peritoneal cavity of mice challenged with antigen (ovalbumin) or ET-1. Levels of ET-1, tumour necrosis factor α (TNFα), and CXC chemokine ligand 1 (CXCL1) were determined by enzyme-linked immunosorbent assay. Neutrophil migration and flow cytometry analyses were performed 4 h after the intraperitoneal stimulus. ET-1 induced dose-dependent neutrophil recruitment to the peritoneal cavity. Treatment with the non-selective ET(A)/ET(B) receptor antagonist bosentan, and selective ET(A) or ET(B) receptor antagonists BQ-123 or BQ-788, respectively, inhibited ET-1- and ovalbumin-induced neutrophil migration to the peritoneal cavity. In agreement with the above, the antigen challenge significantly increased levels of ET-1 in peritoneal exudates. The ET-1- and ovalbumin-induced neutrophil recruitment were reduced in TNFR1 deficient mice, and by treatments targeting CXCL1 or CXC chemokine receptor 2 (CXCR2); further, treatment with bosentan, BQ-123, or BQ-788 inhibited ET-1- and antigen-induced production of TNFα and CXCL1. Furthermore, ET-1 and ovalbumin challenge induced an increase in the number of cells expressing the Gr1(+) markers in the granulocyte gate, CD11c(+) markers in the monocyte gate, and CD4(+) and CD45(+) (B220) markers in the lymphocyte gate in an ET(A)- and ET(B)-dependent manner, as determined by flow cytometry analysis, suggesting that ET-1 might be involved in the recruitment of neutrophils and other cells in adaptive inflammation. Therefore, the present study demonstrates that ET-1 is an important mediator for neutrophil recruitment in adaptive inflammation via TNFα and CXCL1/CXCR2-dependent mechanism.


Subject(s)
Adaptive Immunity , Chemokine CXCL1/metabolism , Chemotaxis, Leukocyte , Endothelin-1/metabolism , Inflammation/metabolism , Neutrophils/metabolism , Receptors, Interleukin-8B/metabolism , Tumor Necrosis Factor-alpha/metabolism , Animals , Disease Models, Animal , Endothelin-1/administration & dosage , Enzyme-Linked Immunosorbent Assay , Flow Cytometry , Inflammation/chemically induced , Inflammation/immunology , Injections, Intraperitoneal , Mice , Mice, Inbred C57BL , Mice, Knockout , Neutrophils/immunology , Ovalbumin , Receptor, Endothelin A/metabolism , Receptor, Endothelin B/metabolism , Receptors, Tumor Necrosis Factor, Type I/deficiency , Receptors, Tumor Necrosis Factor, Type I/genetics , Time Factors
14.
Biochem Biophys Res Commun ; 417(4): 1113-8, 2012 Jan 27.
Article in English | MEDLINE | ID: mdl-22209790

ABSTRACT

The endothelin system consists of three ligands (ET-1, ET-2 and ET-3) and at least two receptors (ETA and ETB). In mice ET-2 counterpart is a peptide originally called "vasoactive intestinal contractor" (VIC) for this reason, this peptide is frequently named ET-2/VIC. In intestinal villi, fibroblasts-like cells express endothelin's receptors and response to ET-1 and ET-3 peptides, changing their cellular shape. Several functions have been attributed to these peptides in the "architecture" maintenance of intestinal villi acting over sub-epithelial fibroblasts. Despite this, ET-2/VIC has not been analyzed in depth. In this work we show the intestine gene expression and immunolocalization of ET-1, ET-2 and the ETA and ETB receptors from duodenum to rectus and in the villus-crypt axis in mice, allowing a complete analysis of their functions. While ET-1 is expressed uniformly, ET-2 had a particular distribution, being higher at the bottom of the villi of duodenum, ileum and jejunum and reverting this pattern in the crypts of colon and rectus, where the higher expression was at the top. We postulated that ET-2 would act in a cooperative manner with ET-1, giving to the villus the straight enough to withstand mechanical stress.


Subject(s)
Endothelin-1/metabolism , Endothelin-2/metabolism , Intestines/cytology , Intestines/physiology , Stress, Mechanical , Animals , Endothelin-1/genetics , Endothelin-2/genetics , Fibroblasts/metabolism , Gene Expression Regulation , Intestinal Mucosa/metabolism , Male , Mice , Mice, Inbred ICR , Muscle Contraction , Muscle, Smooth/physiology , Permeability , Receptor, Endothelin A/genetics , Receptor, Endothelin A/metabolism , Receptor, Endothelin B/genetics , Receptor, Endothelin B/metabolism
15.
Br J Pharmacol ; 165(5): 1333-47, 2012 Mar.
Article in English | MEDLINE | ID: mdl-21797847

ABSTRACT

BACKGROUND AND PURPOSE: Independent studies in experimental models of Trypanosoma cruzi appointed different roles for endothelin-1 (ET-1) and bradykinin (BK) in the immunopathogenesis of Chagas disease. Here, we addressed the hypothesis that pathogenic outcome is influenced by functional interplay between endothelin receptors (ET(A)R and ET(B)R) and bradykinin B(2) receptors (B(2)R). EXPERIMENTAL APPROACH: Intravital microscopy was used to determine whether ETR/B(2)R drives the accumulation of rhodamine-labelled leucocytes in the hamster cheek pouch (HCP). Inflammatory oedema was measured in the infected BALB/c paw of mice. Parasite invasion was assessed in CHO over-expressing ETRs, mouse cardiomyocytes, endothelium (human umbilical vein endothelial cells) or smooth muscle cells (HSMCs), in the presence/absence of antagonists of B(2)R (HOE-140), ET(A)R (BQ-123) and ET(B)R (BQ-788), specific IgG antibodies to each GPCRs; cholesterol or calcium-depleting drugs. RNA interference (ET(A)R or ET(B)R genes) in parasite infectivity was investigated in HSMCs. KEY RESULTS: BQ-123, BQ-788 and HOE-140 reduced leucocyte accumulation in HCP topically exposed to trypomastigotes and blocked inflammatory oedema in infected mice. Acting synergistically, ET(A)R and ET(B)R antagonists reduced parasite invasion of HSMCs to the same extent as HOE-140. Exogenous ET-1 potentiated T. cruzi uptake by HSMCs via ETRs/B(2)R, whereas RNA interference of ET(A)R and ET(B)R genes conversely reduced parasite internalization. ETRs/B(2)R-driven infection in HSMCs was reduced in HSMC pretreated with methyl-ß-cyclodextrin, a cholesterol-depleting drug, or in thapsigargin- or verapamil-treated target cells. CONCLUSIONS AND IMPLICATIONS: Our findings suggest that plasma leakage, a neutrophil-driven inflammatory response evoked by trypomastigotes via the kinin/endothelin pathways, may offer a window of opportunity for enhanced parasite invasion of cardiovascular cells.


Subject(s)
Chagas Disease/metabolism , Chagas Disease/parasitology , Receptor, Bradykinin B2/metabolism , Receptor, Endothelin A/metabolism , Receptor, Endothelin B/metabolism , Trypanosoma cruzi/metabolism , Animals , Bradykinin B2 Receptor Antagonists , CHO Cells , Calcium/metabolism , Cells, Cultured , Chagas Disease/immunology , Chagas Disease/pathology , Cricetinae , Edema/metabolism , Edema/pathology , Endothelin A Receptor Antagonists , Endothelin B Receptor Antagonists , Endothelin-1/metabolism , Human Umbilical Vein Endothelial Cells/parasitology , Humans , Inflammation/metabolism , Inflammation/pathology , Kinins/metabolism , Mice , Mice, Inbred BALB C , Myocytes, Cardiac/metabolism , Myocytes, Cardiac/pathology , Myocytes, Smooth Muscle/metabolism , Myocytes, Smooth Muscle/pathology , Trypanosoma cruzi/immunology
16.
Rev Bras Cir Cardiovasc ; 27(4): 512-9, 2012 Dec.
Article in English | MEDLINE | ID: mdl-23515723

ABSTRACT

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.


Subject(s)
Endothelin-3/genetics , Gene Expression/genetics , Mitral Valve Stenosis/genetics , Receptor, Endothelin A/genetics , Receptor, Endothelin B/genetics , Rheumatic Heart Disease/genetics , Adult , Endothelin-3/metabolism , Female , Heart Valve Prosthesis Implantation , Humans , Male , Mitral Valve Stenosis/surgery , Receptor, Endothelin A/metabolism , Receptor, Endothelin B/metabolism , Rheumatic Heart Disease/metabolism , Rheumatic Heart Disease/surgery
17.
Neurochem Int ; 57(3): 306-13, 2010 Oct.
Article in English | MEDLINE | ID: mdl-20600439

ABSTRACT

We have previously reported that endothelin-1 and -3 modulate different steps of noradrenergic transmission in the hypothalamus. We showed that endothelins modify neuronal norepinephrine transport activity through the regulation of the kinetic constant and internalization. In the present work we sought to define the endothelin receptors and intracellular mechanisms involved in the down-regulation of neuronal norepinephrine uptake induced by endothelin-1 and -3 in the rat posterior hypothalamic region. Results showed that endothelin-1 reduced norepinephrine uptake through ET(B) receptors, whereas endothelin-3 through a non-conventional or atypical endothelin receptor. In both cases, the effect on norepinephrine uptake was coupled to protein kinase A and C as well as nitric oxide pathways. However, neither protein kinase G nor intracellular or extracellular calcium and calcium/calmodulin-dependent protein kinase II were involved. In addition, the same intracellular mechanisms participated in the reduction of nisoxetine binding (norepinephrine transporter internalization index) induced by both endothelins. Present findings reveal the underlying mechanisms involved in the regulation of the neuronal norepinephrine transporter by endothelins and further support the role of these peptides in the modulation of noradrenergic transmission at the presynaptic nerve endings in the posterior hypothalamus.


Subject(s)
Endothelin-1/pharmacology , Endothelin-3/pharmacology , Hypothalamus, Posterior/metabolism , Neurons/metabolism , Norepinephrine Plasma Membrane Transport Proteins/metabolism , Signal Transduction/drug effects , Adenylyl Cyclases/metabolism , Animals , Cyclic AMP-Dependent Protein Kinases/metabolism , Enzyme Activation/drug effects , Fluoxetine/analogs & derivatives , Fluoxetine/metabolism , Hypothalamus, Posterior/drug effects , Male , Neurons/drug effects , Nitric Oxide/metabolism , Norepinephrine/metabolism , Oligopeptides/pharmacology , Piperidines/pharmacology , Protein Kinase C/metabolism , Rats , Rats, Sprague-Dawley , Receptor, Endothelin A/drug effects , Receptor, Endothelin A/metabolism , Receptor, Endothelin B/drug effects , Receptor, Endothelin B/metabolism
18.
Brain Res ; 1345: 73-83, 2010 Jul 23.
Article in English | MEDLINE | ID: mdl-20450894

ABSTRACT

The trigeminal nerve is comprised of three main divisions, ophthalmic, maxillary and mandibular, each providing somatosensory innervation to distinct regions of the head, face and oral cavity. Recently, a role for endothelins in nociceptive signaling in the trigeminal system has been proposed. The present study aimed to gain better insight into the participation of the endothelin system in trigeminal nociceptive transmission. Herein ET-1 and ET-3 mRNA was detected in the rats' trigeminal ganglion (TG). Fluorescent labeling of TG neurons revealed that ET(A) and ET(B) receptors are distributed along the entire TG, but ET(A) receptor expression slightly predominated within the three divisions. TRPV1 receptors were also detected throughout the entire TG, and a significant proportion of TRPV1-positive neurons (approximately 30%) co-expressed either ET(A) or ET(B) receptors. Our behavioral data showed that ET-1 (3 to 30 pmol/site) induced overt nociceptive responses after injection into the upper lip or temporomandibular joint (TMJ) and hyperalgesic actions when applied to the eye, while ET-3 and the selective ET(B) receptor agonist IRL-1620 (each at 3 to 30 pmol/site) showed only the first two effects. Injection of BQ-123, but not BQ-788 (ET(A) and ET(B) receptor antagonists, respectively, 10 nmol/site each, 30 min beforehand), into the ipsilateral upper lip abolished ET-1 induced facial grooming, but both antagonists markedly reduced the nociceptive responses induced by ET-1 injected into the TMJ. Taken together, these findings suggest that endothelins, acting through ET(A) and/or ET(B) receptors, may play an important role in mediating pain resulting from activation of most trigeminal nerve branches.


Subject(s)
Endothelin-1/metabolism , Endothelin-3/metabolism , Facial Pain/metabolism , Receptor, Endothelin A/metabolism , Receptor, Endothelin B/metabolism , Trigeminal Ganglion/metabolism , Animals , Endothelin A Receptor Antagonists , Endothelin B Receptor Antagonists , Endothelins/metabolism , Endothelins/pharmacology , Eye/metabolism , Facial Pain/drug therapy , Lip/metabolism , Male , Neurons/drug effects , Neurons/metabolism , Oligopeptides/pharmacology , Peptide Fragments/pharmacology , Peptides, Cyclic/pharmacology , Piperidines/pharmacology , RNA, Messenger/metabolism , Rats , Rats, Wistar , Sensory System Agents/pharmacology , TRPV Cation Channels/metabolism , Temporomandibular Joint/metabolism , Trigeminal Ganglion/drug effects
19.
Neurosci Lett ; 457(3): 146-50, 2009 Jul 03.
Article in English | MEDLINE | ID: mdl-19429182

ABSTRACT

Increasing evidence indicates that endothelin-1 (ET-1) activates nociceptive neurons and sensitizes them to different noxious stimuli, but involvement of TRPV1-dependent mechanisms in mediation of such effects is not yet fully understood. Here we report that intraplantar (i.pl.) injection of ET-1 (10 pmol) into the hind paw of rats induced overt nociceptive behavior over the first hour, followed by a slowly developing thermal hyperalgesia, lasting from 3 to 8h after injection. Both effects were also induced by similar injections of capsaicin (10-1000 pmol), but these responses were shorter lasting than those caused by ET-1. Local pre-treatment with the TRPV1 antagonist capsazepine (30 nmol, i.pl.) reduced only the thermal hyperalgesia induced by ET-1, but fully suppressed both responses to capsaicin (1000 pmol). Injection of a sub-threshold dose of ET-1 (0.1 pmol, i.pl.) prior to capsaicin (1 pmol, i.pl.) markedly sensitized the hind paw to the overt nociceptive and thermal hyperalgesic effects of the later. The potentiation of capsaicin-induced nociception by ET-1 was abolished by prior i.pl. injection of BQ-123 (ET(A) receptor antagonist, 10 nmol), but unaffected by BQ-788 (ET(B) receptors antagonist, 10 nmol), whereas the enhancement of capsaicin-induced hyperalgesia by ET-1 was attenuated by both antagonists. Therefore, differently to what has been reported in mice, in rats TRPV1 receptors contribute selectively to thermal hyperalgesia, but not overt nociception, induced by ET-1. Importantly, although ET-1 augments capsaicin-induced overt nociception and thermal hyperalgesia, potentiation of the former relies solely on ET(A) receptor-mediated signaling mechanisms, whereas both receptors contribute to the latter.


Subject(s)
Capsaicin/pharmacology , Endothelin-1/metabolism , Hyperalgesia/physiopathology , Receptor, Endothelin A/metabolism , Receptor, Endothelin B/metabolism , Sensory System Agents/pharmacology , Analysis of Variance , Animals , Capsaicin/analogs & derivatives , Dose-Response Relationship, Drug , Endothelin A Receptor Antagonists , Endothelin B Receptor Antagonists , Hindlimb/drug effects , Hyperalgesia/chemically induced , Male , Oligopeptides/pharmacology , Pain Measurement , Peptides, Cyclic/pharmacology , Physical Stimulation , Piperidines/pharmacology , Rats , Rats, Wistar , TRPV Cation Channels/antagonists & inhibitors , Temperature
20.
Article in English | MEDLINE | ID: mdl-18436483

ABSTRACT

Endothelins (ETs) are vasoactive peptides evolutionary well conserved that exert their effects through two specific receptors (ET(A) and ET(B)) widely distributed in all vertebrates. In snakes, the presence and function of endothelins and their receptors are still scarcely described. We have recently demonstrated the presence of ET(A) and ET(B2) receptors in the snake Bothrops jararaca (Bj). In the present work we showed that distinctively from Bj, the vascular contraction induced by endothelin in Oxyrhopus guibei (Og) snake is mediated only by ET(A) receptors. Selective ET(B) agonists (SRTX-c and IRL(1620)) and antagonists (IRL(1038) and BQ(788)) were ineffective in Og preparations of isolated aorta. We also showed that ET-1 response on Og arterial blood pressure was monophasic hypertensive as opposed to biphasic (hypotension followed by hypertension) in Bj. Furthermore, we characterized the relaxing properties of endothelin receptor ET(B1) in pre-contracted aorta preparations. We showed that IRL(1620) induced relaxation of pre-contracted Bj aorta but was ineffective in relaxing Og preparations. IRL(1620) relaxing effect on Bj aorta was abolished by l-NAME, indicating involvement of NO release, and was reduced by selective ET(B) antagonists. Our findings suggest that Og snake has a more primitive spectrum of ET receptors (only ET(A) receptor) than Bj (presence of ET(A), ET(B1) and ET(B2) receptors).


Subject(s)
Aorta/metabolism , Bothrops/metabolism , Colubridae/metabolism , Endothelins/metabolism , Receptor, Endothelin A/metabolism , Receptor, Endothelin B/metabolism , Vasoconstriction , Vasodilation , Animals , Aorta/drug effects , Blood Pressure/drug effects , Dose-Response Relationship, Drug , Endothelins/pharmacology , Enzyme Inhibitors/pharmacology , NG-Nitroarginine Methyl Ester/pharmacology , Nitric Oxide/metabolism , Nitric Oxide Synthase/antagonists & inhibitors , Nitric Oxide Synthase/metabolism , Oligopeptides/pharmacology , Peptide Fragments/pharmacology , Peptides/pharmacology , Piperidines/pharmacology , Receptor, Endothelin A/drug effects , Receptor, Endothelin B/drug effects , Vasoconstriction/drug effects , Vasodilation/drug effects , Viper Venoms
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