NLRP3 activation contributes to endothelin-1-induced erectile dysfunction.

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.

Nesiritide protects endothelial function after balloon-induced trauma in the iliac artery in rabbits

To assess the effect of nesiritide on the endothelial function of iliac arteries following endothelia trauma. Right iliac artery trauma was created with a balloon catheter. Ten rabbits were treated with a 4-week subcutaneous injection of nesiritide at a fixed daily dose of 0.1mg/kg. Ten rabbits received daily normal saline injection. Plasma endothelin 1 (ET-1), nitric oxide (NO), and Von Willebrand Factor (vWF) were measured before and after the therapies. Tissue proliferating cell nuclear antigen (PCNA) was measured after the treatment. After the treatment, in the therapeutic group, the area under internal elastic membrane and the residual lumen area were higher than in the normal saline group (P <0.05). The plasma levels of ET-1 (91.6±6.8 vs 114.9±6.3 ng/L, P =0.001), vWF (134.6±10.8% vs 188.8±10.4%, P =0.001) and the ratio of PCNA positive expression (11.7±4.2% vs 36.2±11.4%, P =0.005) in the therapeutic group was lower than in the normal saline group, while the plasma levels of NO was higher (89.7±9.3 vs 43.5±5.3 µmol/L, P =0.001). Nesiritide inhibited remodeling of rabbit iliac artery following endothelial trauma. The inhibition of vascular remodeling may be related to the alleviated endothelial dysfunction and reduced expression of tissue proliferating cell nuclear antigen

The Histone Demethylase JMJD2A Modulates the Induction of Hypertrophy Markers in iPSC-Derived Cardiomyocytes.

The development of cardiovascular pathologies is partly attributed to epigenetic causes, including histone methylation, which appears to be an important marker in hearts that develop cardiac hypertrophy. Previous studies showed that the histone demethylase JMJD2A can regulate the hypertrophic process in murine cardiomyocytes. However, the influence of JMJD2A on cardiac hypertrophy in a human cardiomyocyte model is still poorly understood. In the present study, cardiomyocytes derived from human induced pluripotent stem cells (iPSCs) were used. Hypertrophy was induced by angiotensin II and endothelin-1 (ET-1), and transfections were performed to overexpress JMJD2A and for small interfering RNA (siRNA)-induced silencing of JMJD2A. Gene expression analyses were determined using RT-PCR and Western blot. The expression levels of B-type natriuretic peptide (BNP), natriuretic peptide A (ANP), and beta myosin heavy chain (ß-MHC) were increased by nearly 2-10-fold with ET-1 compared with the control. However, a higher level of JMJD2A and UTX was detected, whereas the level of JMJD2C was lower. When cardiomyocytes were transiently transfected with JMJD2A, an increase close to 150% in BNP was observed, and this increase was greater after treatment with ET-1. To verify the specificity of JMJD2A activity, a knockdown was performed by means of siRNA-JMJD2A, which led to a significant reduction in BNP. The involvement of JMJD2A suggests that histone-specific modifications are associated with genes encoding proteins that are actively transcribed during the hypertrophy process. Since BNP is closely related to JMJD2A expression, we suggest that there could be a direct influence of JMJD2A on the expression of BNP. These results may be studied further to reduce cardiac hypertrophy via the regulation of epigenetic modifiers.

Sildenafil (Viagra®) Prevents Cox-1/ TXA2 Pathway-Mediated Vascular Hypercontractility in ApoE-/- Mice.

BACKGROUND/AIMS: The atherosclerotic apolipoprotein E-deficient (apoE-/-) mouse exhibits impaired vasodilation and enhanced vasoconstriction responsiveness. The objectives of this study were: a) to determine the relative contribution of cyclooxygenases (Cox-1 and Cox-2), thromboxane A2 (TXA2) and endothelin-1 (ET-1) to enhancing vascular hyperresponsiveness in this model of atherosclerosis and b) to investigate the beneficial effects of the phosphodiesterase 5 inhibitor sildenafil on this endothelial dysfunction. METHODS: Adult male apoE-/- mice were treated with sildenafil (40 mg/kg/day, for 3 weeks) and compared with non-treated ApoE-/- and wild-type mice. The beneficial effects of sildenafil on vascular contractile response to phenylephrine (PE) in aortic rings were evaluated before and after incubation with Cox-1 (SC-560) or Cox-2 (NS-398) inhibitors or the TP antagonist SQ-29548, and on contractile responsiveness to ET-1. RESULTS: ApoE-/- mice exhibited enhanced vasoconstriction to PE (Rmax ∼35%, p<0.01), which was prevented by treatment with sildenafil. The enhanced PE-induced contractions were abolished by both Cox-1 inhibition and TP antagonist, but were not modified by Cox-2 inhibition. Aortic rings from ApoE-/- mice also exhibited enhanced contractions to ET-1 (Rmax ∼30%, p<0.01), which were attenuated in sildenafil-treated ApoE-/- mice. In addition, we observed augmented levels of vascular proinflammatory cytokines in ApoE-/- mice, which were partially corrected by treatment with sildenafil (IL-6, IL-10/IL-6 ratio and MCP-1). CONCLUSION: The present data show that the Cox-1/TXA2 pathway prevails over the Cox-2 isoform in the mediation of vascular hypercontractility observed in apoE-/-mice. The results also show a beneficial effect of sildenafil on this endothelial dysfunction and on the proinflammatory cytokines in atherosclerotic animals, opening new perspectives for the treatment of other endothelium-related cardiovascular abnormalities.

Evaluation of biochemical and clinical markers of endothelial dysfunction and their correlation with urinary albumin excretion in patients with type 1 diabetes mellitus

ABSTRACT Objective Endothelial dysfunction (ED) plays an important role in the pathogenesis of diabetic nephropathy. The purpose of the study was to determine flow mediated endothelial dependent vasodilatation (FMD) measurements and serum soluble (s) endothelin-1 (ET-1), intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule (VCAM-1) levels in patients with type 1 diabetes mellitus (T1DM) with or without increased urinary albumin excretion (UAE) and compare them with the healthy controls. Subjects and methods Seventy three patients with T1DM were enrolled. Patients were divided into two subgroups according to microalbumin measurements in 24-hr urine collections. The diabetic patients without microalbuminuria (41 patients) were defined as Group I and those with microalbuminuria (32 patients) were defined as group II. A hundred age and sex matched healthy subjects participated as the control group (Group III). Serum sET-1, sICAM-1, sVCAM-1 levels and FMD measurements were determined in all participants. Results Median FMD measurement was significantly lower in the diabetic groups compared with the control group (6.6, 6.4 and 7.8% in Group I, II and III, respectively) (p < 0.05). FMD was negatively correlated with age (p = 0.042). Median serum sICAM-1 level was higher in the patient groups compared to the control group (p < 0.05). Median serum sVCAM-1 level was higher in the group of patients with increased albuminuria compared to the normoalbuinuric and the control group (p < 0.05). Serum sVCAM-1 level was found to be positively correlated with degree of urinary albumin excretion (p < 0.001). Conclusion We assume that sVCAM-1 may be used as a predictive marker for risk stratification for nephropathy development and progression.

Mensuração de endotelina-1 sérica em gatos sadios da raça maine coon / Serum endothelin-1 measurement in healthy maine coon cats

A concentração plasmática de endotelina (ET)-1 aumenta em pacientes humanos com insuficiência cardíaca congestiva, sendo correlacionada com o grau de alteração hemodinâmica e funcional e, ainda, com proliferação celular, vasoconstricção, hipertrofia de miócitos cardíacos e ativação de fibroblastos cardíacos, que se associam às manifestações clínicas da insuficiência cardíaca (IC) e ao remodelamento patológico do coração. A cardiomiopatia hipertrófica (CMH) é a doença cardíaca mais diagnosticada em gatos e caracterizada por aumento da massa cardíaca associado à hipertrofia concêntrica do ventrículo esquerdo (HVE) que, em gatos da raça Maine Coon (MC), está associada à mutação do gene da ß-miosina ligada à proteína C (MYBPC3). Foram mensuradas concentrações séricas de ET-1 em 38 gatos sadios da raça MC utilizando ensaio ELISA humano, validado para a espécie felina. Infelizmente, não foi possível determinar os valores de ET-1 no presente estudo, pois estes se encontravam acima dos níveis de sensibilidade do ensaio utilizado. A mensuração sérica de ET-1 sem adição de aprotinina em gatos saudáveis da raça MC são superiores aos valores de concentração plasmática de ET-1 com adição de aprotinina em gatos saudáveis como reportado pela literatura com o kit diagnóstico Biomédica Endothelin (1-21). Ao utilizar esse kit diagnóstico para mensuração sérica de ET-1 sem aprotinina em gatos da

The plasma concentration of endothelin (ET)-1 increases in human patients with congestive heart failure and is correlated with the degree of hemodynamic and functional changes. An increase in plasma ET-1 concentration is also correlated with cell proliferation, vasoconstriction, hypertrophy of cardi omyocytes and activation of cardiac fibroblasts, all of which are associated with clinical manifestations of heart failure (HF) and pathological remodeling of the heart. Hypertrophic cardiomyopathy (HCM) is the most commonly diagnosed heart disease in cats and is characterized by increased cardiac mass associated with concentric left ventricular hypertrophy (LVH), which is associated with mutations in the cardiac myosin binding protein C (MYBPC3) gene in Maine Coon (MC) cats. ET-1 serum concentrations were measured in 38 healthy MC cats using the human ELISA assay validated for the feline species. Unfortunately, the ET-1 values could not be assessed in the present study because they were above the maximum levels of sensitivity of the test used. ET-1 serum measurements without aprotinin in healthy MC cats is greater than values ET-1 plasma concentration with aprotinin reported by literature in healthy cats using the Biomedica Endothelin (1-21) diagnosis kit. Using this kit for serum ET-1 measurements without aprotinin in MC cats the dilution of samples is necessary.

Mensuração de endotelina-1 sérica em gatos sadios da raça maine coon / Serum endothelin-1 measurement in healthy maine coon cats

A concentração plasmática de endotelina (ET)-1 aumenta em pacientes humanos com insuficiência cardíaca congestiva, sendo correlacionada com o grau de alteração hemodinâmica e funcional e, ainda, com proliferação celular, vasoconstricção, hipertrofia de miócitos cardíacos e ativação de fibroblastos cardíacos, que se associam às manifestações clínicas da insuficiência cardíaca (IC) e ao remodelamento patológico do coração. A cardiomiopatia hipertrófica (CMH) é a doença cardíaca mais diagnosticada em gatos e caracterizada por aumento da massa cardíaca associado à hipertrofia concêntrica do ventrículo esquerdo (HVE) que, em gatos da raça Maine Coon (MC), está associada à mutação do gene da ß-miosina ligada à proteína C (MYBPC3). Foram mensuradas concentrações séricas de ET-1 em 38 gatos sadios da raça MC utilizando ensaio ELISA humano, validado para a espécie felina. Infelizmente, não foi possível determinar os valores de ET-1 no presente estudo, pois estes se encontravam acima dos níveis de sensibilidade do ensaio utilizado. A mensuração sérica de ET-1 sem adição de aprotinina em gatos saudáveis da raça MC são superiores aos valores de concentração plasmática de ET-1 com adição de aprotinina em gatos saudáveis como reportado pela literatura com o kit diagnóstico Biomédica Endothelin (1-21). Ao utilizar esse kit diagnóstico para mensuração sérica de ET-1 sem aprotinina em gatos da

The plasma concentration of endothelin (ET)-1 increases in human patients with congestive heart failure and is correlated with the degree of hemodynamic and functional changes. An increase in plasma ET-1 concentration is also correlated with cell proliferation, vasoconstriction, hypertrophy of cardi omyocytes and activation of cardiac fibroblasts, all of which are associated with clinical manifestations of heart failure (HF) and pathological remodeling of the heart. Hypertrophic cardiomyopathy (HCM) is the most commonly diagnosed heart disease in cats and is characterized by increased cardiac mass associated with concentric left ventricular hypertrophy (LVH), which is associated with mutations in the cardiac myosin binding protein C (MYBPC3) gene in Maine Coon (MC) cats. ET-1 serum concentrations were measured in 38 healthy MC cats using the human ELISA assay validated for the feline species. Unfortunately, the ET-1 values could not be assessed in the present study because they were above the maximum levels of sensitivity of the test used. ET-1 serum measurements without aprotinin in healthy MC cats is greater than values ET-1 plasma concentration with aprotinin reported by literature in healthy cats using the Biomedica Endothelin (1-21) diagnosis kit. Using this kit for serum ET-1 measurements without aprotinin in MC cats the dilution of samples is necessary.