RESUMO
In the present study, we hypothesized that endothelin (ET) receptors (ETA and ETB ) stimulation, through increased calcium and ROS formation, leads to Nucleotide Oligomerization Domain-Like Receptor Family, Pyrin Domain Containing 3 (NLRP3) activation. Intracavernosal pressure (ICP/MAP) was measured in C57BL/6 (WT) mice. Functional and immunoblotting assays were performed in corpora cavernosa (CC) strips from WT, NLRP3-/- and caspase-/- mice in the presence of ET-1 (100 nM) and vehicle, MCC950, tiron, BAPTA AM, BQ123, or BQ788. ET-1 reduced the ICP/MAP in WT mice, and MCC950 prevented the ET-1 effect. ET-1 decreased CC ACh-, sodium nitroprusside (SNP)-induced relaxation, and increased caspase-1 expression. BQ123 an ETA receptor antagonist reversed the effect. The ETB receptor antagonist BQ788 also reversed ET-1 inhibition of ACh and SNP relaxation. Additionally, tiron, BAPTA AM, and NLRP3 genetic deletion prevented the ET-1-induced loss of ACh and SNP relaxation. Moreover, BQ123 diminished CC caspase-1 expression, while BQ788 increased caspase-1 and IL-1ß levels in a concentration-dependent manner (100 nM-10 µM). Furthermore, tiron and BAPTA AM prevented ET-1-induced increase in caspase-1. In addition, BAPTA AM blocked ET-1-induced ROS generation. In conclusion, ET-1-induced erectile dysfunction depends on ETA - and ETB -mediated activation of NLRP3 in mouse CC via Ca2+ -dependent ROS generation.
Assuntos
Endotelina-1 , Disfunção Erétil , Proteína 3 que Contém Domínio de Pirina da Família NLR , Animais , Masculino , Camundongos , Sal Dissódico do Ácido 1,2-Di-Hidroxibenzeno-3,5 Dissulfônico , Antagonistas dos Receptores de Endotelina , Endotelina-1/metabolismo , Disfunção Erétil/metabolismo , Camundongos Endogâmicos C57BL , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Espécies Reativas de Oxigênio , Receptores de EndotelinaRESUMO
Proline-rich oligopeptides (PROs) are a large family which comprises the bradykinin-potentiating peptides (BPPs). They inhibit the activity of the angiotensin I-converting enzyme (ACE) and have a typical pyroglutamyl (Pyr)/proline-rich structure at the N- and C-terminus, respectively. Furthermore, PROs decrease blood pressure in animals. In the present study, the isolation and biological characterization of a novel vasoactive BPP isolated from the skin secretion of the frog Brachycephalus ephippium is described. This new PRO, termed BPP-Brachy, has the primary structure WPPPKVSP and the amidated form termed BPP-BrachyNH2 inhibits efficiently ACE in rat serum. In silico molecular modeling and docking studies suggest that BPP-BrachyNH2 is capable of forming a hydrogen bond network as well as multiple van der Waals interactions with the rat ACE, which blocks the access of the substrate to the C-domain active site. Moreover, in rat thoracic aorta BPP-BrachyNH2 induces potent endothelium-dependent vasodilatation with similar magnitude as captopril. In DAF-FM DA-loaded aortic cross sections examined by confocal microscopy, BPP-BrachyNH2 was found to increase the release of nitric oxide (NO). Moreover, BPP-BrachyNH2 was devoid of toxicity in endothelial and smooth muscle cell cultures. In conclusion, the peptide BPP-BrachyNH2 has a novel sequence being the first BPP isolated from the skin secretion of the Brachycephalidae family. This opens for exploring amphibians as a source of new biomolecules. The BPP-BrachyNH2 is devoid of cytotoxicity and elicits endothelium-dependent vasodilatation mediated by NO. These findings open for the possibility of potential application of these peptides in the treatment of endothelial dysfunction and cardiovascular diseases.
Assuntos
Inibidores da Enzima Conversora de Angiotensina/metabolismo , Anuros/metabolismo , Oligopeptídeos/metabolismo , Pele/metabolismo , Sequência de Aminoácidos , Inibidores da Enzima Conversora de Angiotensina/síntese química , Inibidores da Enzima Conversora de Angiotensina/farmacologia , Animais , Aorta Torácica/citologia , Domínio Catalítico , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Células Endoteliais da Veia Umbilical Humana , Humanos , Masculino , Óxido Nítrico/metabolismo , Oligopeptídeos/química , Oligopeptídeos/farmacologia , Peptidil Dipeptidase A/química , Peptidil Dipeptidase A/metabolismo , Prolina/química , Ligação Proteica , Estrutura Secundária de Proteína , Ratos , Ratos WistarRESUMO
El Síndrome de Ovarios Poliquísticos (PCOS/SOP) es la patología endocrinológica más común en la mujer en edad reproductiva. Este trabajo tuvo como objetivo ilustrar, a través de una revisión sistemática de la literatura publicada hasta el presente la presencia de Hipertensión y enfermedad macro/microvascular, evaluada por la presencia de pre- o microalbuminuria (PMA o MA), en el Síndrome de Ovarios Poliquísticos. La búsqueda bibliográfica se realizó siguiendo los principios que rigen el "método de revisión sistemática" (systematic review). En muchos de los artículos y trabajos revisados, se ha demostrado, que el Síndrome Metabólico (SM) y PCOS están fisiopatológicamente vinculados, ya que ambos comparten, como central elemento en su mecanismo fisiopatológico, la resistencia a la insulina (IR). Dicha IR produce un efecto deletéreo sobre la función vascular, es decir que la misma coexiste junto a una disfunción vascular generalizada, lo cual se refleja en la excresión aumentada de albúmina en orina, más precisamente microalbuminuria. Luego de haber realizado una búsqueda sistemática del tema en todas las bases de datos internacionales, podemos concluir que existen numerosos artículos e investigaciones en los que se describe en detalle la alta tasa de incidencia de hipertensión entre las pacientes con PCOS. Por el contrario, la presencia de microalbuminuria (MA) como marcador de riesgo de enfermedad macro/ microvascular en pacientes con PCOS, está pobremente descripta; pero los escasos artículos encontrados señalan una alta prevalencia de la misma (16% o 24% dependiendo de los criterios con los que se define MA) y de premicroalbuminuria (PMA) (31,2% ) entre estas pacientes. Además se encontró que 30,9% de estas pacientes con PMA y PCOS tienen: Síndrome metabólico, elevada prevalencia de hipertensión y elevada ALAT sérica. La evaluación de la excreción de albúmina en orina (EAU) en presencia de PCOS proporciona importante información clínica y puede ayudar en la selección apropiada de aquellas pacientes que necesiten un tratamiento más agresivo con respecto a su hipertensión o a una posible hipertensión al límite (borderline). A pesar de la elevada prevalencia a nivel mundial del PCOS, todavía no se ha establecido, en el plano internacional, una estrategia de diagnóstico y un programa de seguimiento para detectar la presencia de enfermedad cardiovascular, así como un plan de tratamiento completo para estas pacientes.
The polycystic ovary syndrome (PCOS) is the most prevalent endocrinological disease in premenopausal women. The incidence is increasing, partly due to the increased incidence of obesity. PCOS is associated with an increased morbidity from cardiovascular disease and a number of risk factors described in the metabolic syndrome have been identified also in PCOS. We conducted a systematic review of the literature to descibe the prevalence of hypertension as a marker of permanent, and microalbuminuria as a marker of early, vascular stress. Hypertension was described as frequent among patients with PCOS, particularly frequent with obesity, severe menstrual disturbances and severe hyperandrogenemia. Microalbuminuria (MA) and premicroalbuminuria( PMA) as risk factors were poorly described in PCOS. However a prevalence of 16% or 24% (depending of the used criteria) of MA and a prevalence of 31,2% of PMA has been proposed among these patients, indicating a need to monitor, and in future trials intervene against, these risk factors.