RESUMO
Perivascular adipose tissue (PVAT) negatively regulates vascular muscle contraction. However, in the context of obesity, the PVAT releases vasoconstrictor substances that detrimentally affect vascular function. A pivotal player in this scenario is the peptide endothelin-1 (ET-1), which induces oxidative stress and disrupts vascular function. The present study postulates that obesity augments ET-1 production in the PVAT, decreases the function of the nuclear factor erythroid 2-related factor-2 (Nrf2) transcription factor, further increasing reactive oxygen species (ROS) generation, culminating in PVAT dysfunction. Male C57BL/6 mice were fed either a standard or a high-fat diet for 16 weeks. Mice were also treated with saline or a daily dose of 100 mg·kg-1 of the ETA and ETB receptor antagonist Bosentan, for 7 days. Vascular function was evaluated in thoracic aortic rings, with and without PVAT. Mechanistic studies utilized PVAT from all groups and cultured WT-1 mouse brown adipocytes. PVAT from obese mice exhibited increased ET-1 production, increased ECE1 and ETA gene expression, loss of the anticontractile effect, as well as increased ROS production, decreased Nrf2 activity, and downregulated expression of Nrf2-targeted antioxidant genes. PVAT of obese mice also exhibited increased expression of Tyr216-phosphorylated-GSK3ß and KEAP1, but not BACH1 - negative Nrf2 regulators. Bosentan treatment reversed all these effects. Similarly, ET-1 increased ROS generation and decreased Nrf2 activity in brown adipocytes, events mitigated by BQ123 (ETA receptor antagonist). These findings place ET-1 as a major contributor to PVAT dysfunction in obesity and highlight that pharmacological control of ET-1 effects restores PVAT's cardiovascular protective role.
Assuntos
Tecido Adiposo , Regulação para Baixo , Endotelina-1 , Camundongos Endogâmicos C57BL , Fator 2 Relacionado a NF-E2 , Obesidade , Espécies Reativas de Oxigênio , Animais , Endotelina-1/metabolismo , Obesidade/metabolismo , Obesidade/fisiopatologia , Masculino , Tecido Adiposo/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Bosentana/farmacologia , Dieta Hiperlipídica , Camundongos , Estresse Oxidativo , Receptor de Endotelina A/metabolismo , Receptor de Endotelina A/genética , Enzimas Conversoras de Endotelina/metabolismo , Aorta Torácica/metabolismo , Aorta Torácica/efeitos dos fármacos , Aorta Torácica/fisiopatologiaRESUMO
OBJECTIVE: We aimed to broaden our understanding of a potential interaction between B1R and TLR4, considering earlier studies suggesting that lipopolysaccharide (LPS) may trigger B1R stimulation. METHODS: We assessed the impact of DBK and LPS on the membrane potential of thoracic aortas from C57BL/6, B1R, or TLR4 knockout mice. Additionally, we examined the staining patterns of these receptors in the thoracic aortas of C57BL/6 and in endothelial cells (HBMEC). RESULTS: DBK does not affect the resting membrane potential of aortic rings in C57BL/6 mice, but it hyperpolarizes preparations in B1KO and TLR4KO mice. The hyperpolarization mechanism in B1KO mice involves B2R, and the TLR4KO response is independent of cytoplasmic calcium influx but relies on potassium channels. Conversely, LPS hyperpolarizes thoracic aorta rings in both C57BL/6 and B1KO mice, with the response unaffected by a B1R antagonist. Interestingly, the absence of B1R alters the LPS response to potassium channels. These activities are independent of nitric oxide synthase (NOS). While exposure to DBK and LPS does not alter B1R and TLR4 mRNA expression, treatment with these agonists increases B1R staining in endothelial cells of thoracic aortic rings and modifies the staining pattern of B1R and TLR4 in endothelial cells. Proximity ligation assay suggests a interaction between the receptors. CONCLUSION: Our findings provide additional support for a putative connection between B1R and TLR4 signaling. Given the involvement of these receptors and their agonists in inflammation, it suggests that drugs and therapies targeting their effects could be promising therapeutic avenues worth exploring.
Assuntos
Aorta Torácica , Células Endoteliais , Lipopolissacarídeos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Receptor B1 da Bradicinina , Receptor 4 Toll-Like , Animais , Masculino , Camundongos , Aorta Torácica/metabolismo , Bradicinina/farmacologia , Bradicinina/metabolismo , Células Cultivadas , Células Endoteliais/metabolismo , Inflamação/metabolismo , Lipopolissacarídeos/farmacologia , Potenciais da Membrana/efeitos dos fármacos , Receptor B1 da Bradicinina/metabolismo , Receptor B1 da Bradicinina/genética , Receptor 4 Toll-Like/metabolismo , Receptor 4 Toll-Like/genética , FemininoRESUMO
Perivascular adipose tissue (PVAT) is an adipose layer, surrounding blood vessels, with a local modulatory role. Interleukin-10 (IL-10) has been shown to modulate vascular tissue. This study aimed to characterize the endogenous role of IL-10 in vascular remodeling, and PVAT phenotyping. Thoracic aortic segments from control (C57BL/6J) and IL-10 knockout (IL-10-/-) male mice were used. Analyzes of aorta/PVAT morphometry, and elastin, collagen and reticulin deposition were performed. Tissue uncoupling protein 1 (UCP1) was accessed by Western blotting. Endogenous absence of IL-10 reduced total PVAT area (p = 0.0310), and wall/lumen ratio (p = 0.0024), whereas increased vascular area and thickness (p < 0.0001). Total collagen deposition was augmented in IL-10-/-, but under polarized light, the reduction of collagen-I (p = 0.0075) and the increase of collagen-III (p = 0.0055) was found, simultaneously with reduced elastic fibers deposition (p = 0.0282) and increased deposition of reticular fibers (p < 0.0001). Adipocyte area was augmented in the IL-10 absence (p = 0.0225), and UCP1 expression was reduced (p = 0.0420). Moreover, relative frequency of white adipose cells and connective tissue was augmented in IL-10-/- (p < 0.0001), added to a reduction in brown adipose cells (p < 0.0001). Altogether, these data characterize aorta PVAT from IL-10-/- as a white-like adipocyte phenotype. Endogenous IL-10 prevents vascular remodeling and favors a brown-like adipocyte phenotype, suggesting a modulatory role for IL-10 in PVAT plasticity.
Assuntos
Tecido Adiposo Branco , Interleucina-10 , Camundongos Endogâmicos C57BL , Camundongos Knockout , Remodelação Vascular , Animais , Interleucina-10/metabolismo , Interleucina-10/genética , Remodelação Vascular/genética , Masculino , Camundongos , Tecido Adiposo Branco/metabolismo , Proteína Desacopladora 1/metabolismo , Proteína Desacopladora 1/genética , Aorta Torácica/metabolismo , Aorta Torácica/patologia , Colágeno/metabolismo , Tecido Adiposo/metabolismoRESUMO
Long-term ß-adrenoceptor (ß-AR) stimulation is a pathological mechanism associated with cardiovascular diseases resulting in endothelial and perivascular adipose tissue (PVAT) dysfunction. In this study, we aimed to identify whether ß-adrenergic signaling has a direct effect on PVAT. Thoracic aorta PVAT was obtained from male Wistar rats and cultured ex vivo with the ß-AR agonist isoproterenol (Iso; 1â µM) or vehicle for 24 hours. Conditioned culture medium (CCM) from Iso-treated PVAT induced a marked increase in aorta contractile response, induced oxidative stress, and reduced nitric oxide production in PVAT compared to vehicle. In addition, Iso-treated PVAT and PVAT-derived differentiated adipocytes exhibited higher corticosterone release and protein expression of 11ß-hydroxysteroid dehydrogenase type 1 (11ß-HSD1), an enzyme responsible for de novo synthesis of corticosterone. Macrophages exposed to Iso also exhibited increased corticosterone release in response to ß-AR stimulation. Incubation of Iso-treated PVAT and PVAT-derived differentiated adipocytes with ß3-AR antagonist restored aorta contractile function modulated by Iso-CCM and normalized 11ß-HSD1 protein expression. These results show that ß3-AR signaling leads to upregulation of 11ß-HSD1 in PVAT, thus increasing corticosterone release and contributing to impair the anticontractile function of this tissue.
Assuntos
11-beta-Hidroxiesteroide Desidrogenase Tipo 1 , Corticosterona , Isoproterenol , Animais , Masculino , Ratos , 11-beta-Hidroxiesteroide Desidrogenase Tipo 1/metabolismo , 11-beta-Hidroxiesteroide Desidrogenase Tipo 1/genética , Adipócitos/metabolismo , Adipócitos/efeitos dos fármacos , Tecido Adiposo/metabolismo , Agonistas Adrenérgicos beta/farmacologia , Aorta Torácica/efeitos dos fármacos , Aorta Torácica/metabolismo , Corticosterona/metabolismo , Meios de Cultivo Condicionados/farmacologia , Isoproterenol/farmacologia , Óxido Nítrico/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Ratos Wistar , Receptores Adrenérgicos beta/metabolismoRESUMO
AIM: The present study evaluated whether topiramate (TPM) treatment during the peripubertal period affects vascular parameters of male rats and whether oxidative stress plays a role in these changes. MAIN METHODS: Rats were treated with TPM (41 mg/kg/day, gavage) or vehicle (CTR group) from the postnatal day (PND) 28 to 50. At PND 51 and 120 the rats were evaluated for: thoracic aorta reactivity to phenylephrine, in the presence (Endo+) or absence of endothelium (Endo-), to acetylcholine and to sodium nitroprusside (SNP), aortic thickness and endothelial nitric oxide synthase (eNOS) expression. In serum were analyzed: the antioxidant capacity by ferric reducing antioxidant power assay; endogenous antioxidant reduced glutathione, and superoxide anion. Results were expressed as mean ± s.e.m., differences when p < 0.05. STATISTICS: Two-way ANOVA (and Tukey's) or Student t-test. KEY FINDINGS: At PND 51, the contraction induced by phenylephrine in Endo+ ring was higher in TPM when compared to CTR. At PND 120, the aortic sensitivity to acetylcholine in TPM rats was reduced in comparison with CTR. The aortic eNOs expression and the aortic thickness were similar between the groups. At PND 51 and 120, TPM group presented a decrease in antioxidants when compared to CTR groups and at PND 120, in TPM group the superoxide anion was increased. SIGNIFICANCE: Taken together, the treatment of rats with TPM during peripubertal period promoted permanent impairment of endothelial function probably mediated by oxidative stress.
Assuntos
Acetilcolina , Antioxidantes , Ratos , Animais , Masculino , Antioxidantes/farmacologia , Antioxidantes/metabolismo , Topiramato/farmacologia , Acetilcolina/metabolismo , Superóxidos/metabolismo , Endotélio Vascular/metabolismo , Óxido Nítrico Sintase Tipo III/metabolismo , Estresse Oxidativo , Aorta Torácica/metabolismo , Fenilefrina/farmacologia , Óxido Nítrico/metabolismoRESUMO
Cuphea carthagenensis (Jacq.) J.âF. Macbr. is a popular plant in Brazilian folk medicine owing to its hypotensive and central nervous system depressant effects. This study aimed to validate the hypotensive effect of the plant's aqueous extract (AE) in rats and examine the vascular actions of three hydrolyzable tannins, oenothein B, woodfordin C, and eucalbanin B, isolated from AE. Systolic blood pressure in unanesthetized rats was determined using the non-invasive tail-cuff method. Oral treatment of normotensive rats with 0.5 and 1.0 g/kg/day AE induced a dose-related hypotensive effect after 1 week. In rat aortic rings pre-contracted with noradrenaline, all ellagitannins (20â-â180 µM) induced a concentration-related vasorelaxation. This effect was blocked by either removing the endothelium or pre-incubating with NG-nitro-l-arginine methyl ester (10 µM), an inhibitor of nitric oxide (NO) synthase. In KCl-depolarized rat portal vein preparations, the investigated compounds did not affect significantly the maximal contractile responses and pD2 values of the concentration-response curves to CaCl2. Our results demonstrated the hypotensive effect of C. carthagenensis AE in unanesthetized rats. All isolated ellagitannins induced vasorelaxation in vitro via activating NO synthesis/NO release from endothelial cells, without altering the Ca2+ influx in vascular smooth muscle preparations. Considering the low oral bioavailability of ellagitannins, the determined in vitro actions of these compounds are unlikely to account for the hypotensive effect of AE in vivo. It remains to be determined the role of the bioactive ellagitannin-derived metabolites in the hypotensive effect observed after oral treatment of unanesthetized rats with the plant extract.
Assuntos
Cuphea , Hipotensão , Ratos , Animais , Vasodilatadores/farmacologia , Cuphea/metabolismo , Taninos Hidrolisáveis/farmacologia , Ratos Wistar , Células Endoteliais , Vasodilatação , Endotélio Vascular , Óxido Nítrico/metabolismo , Aorta Torácica/metabolismo , NG-Nitroarginina Metil Éster/farmacologiaRESUMO
Gestational diabetes mellitus (GDM) affects 5-10% of pregnancies and increases the risk of fetal and maternal adverse outcomes. Interestingly, the vascular response to AngII is decreased by pregnancy while the response is increased by diabetes. It remains unclear how GDM affects vascular tone and how angiotensin II receptors contribute to these changes. In this work, we sought to establish the vascular impact of a hypercaloric diet-induced GDM through changes in AT1 and AT2 receptor's expression. Female rats fed for 7 weeks with standard (SD) or hypercaloric (HD) diet were divided at week 4. Half of the rats of each group were mated to become pregnant and those fed with a HD developed GDM. AngII-induced vasoconstriction was measured in thoracic or abdominal aorta rings using a conventional isolated organ bath and AT1 and AT2 receptors were searched by immunohistochemistry. Experiments where conducted on the pregnant standard diet group (PSD) and the pregnant hypercaloric-gestational diabetes mellitus group (PHD-GDM). Vasoconstriction was reduced in the thoracic aorta (P < 0.05 vs PSD) but increased in the abdominal aorta of PHD-GDM rats (P < 0.05 vs PSD). Blockade of AT2 receptors using PD123319 decreased vasoconstriction, particularly in the abdominal aorta of PHD-GDM animals (P < 0.05 vs PSD). PHD-GDM increased AT1 receptors expression (P < 0.05 vs PSD). Also, PHD-GDM reverted physiologic hypoglycemia and hypotension of healthy pregnancy. Findings provide new insight into the hypercaloric diet induced damage on the vasculature during pregnancy.
Assuntos
Aorta Abdominal/metabolismo , Aorta Torácica/metabolismo , Diabetes Gestacional/metabolismo , Endotélio Vascular/metabolismo , Receptor Tipo 1 de Angiotensina/metabolismo , Receptor Tipo 2 de Angiotensina/metabolismo , Vasoconstrição , Angiotensina II/farmacologia , Antagonistas de Receptores de Angiotensina/farmacologia , Animais , Aorta Abdominal/efeitos dos fármacos , Aorta Abdominal/fisiopatologia , Aorta Torácica/efeitos dos fármacos , Aorta Torácica/fisiopatologia , Diabetes Gestacional/fisiopatologia , Modelos Animais de Doenças , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/fisiopatologia , Feminino , Gravidez , Ratos Wistar , Receptor Tipo 1 de Angiotensina/agonistas , Receptor Tipo 2 de Angiotensina/agonistas , Transdução de Sinais , Vasoconstrição/efeitos dos fármacos , Vasoconstritores/farmacologiaRESUMO
We aimed to develop a standardized methodology to determine the metabolic profile of organic extracts from Malvaviscus arboreus Cav. (Malvaceae), a Mexican plant used in traditional medicine for the treatment of hypertension and other illnesses. Also, we determined the vasorelaxant activity of these extracts by ex vivo rat thoracic aorta assay. Organic extracts of stems and leaves were prepared by a comprehensive maceration process. The vasorelaxant activity was determined by measuring the relaxant capability of the extract to decrease a contraction induced by noradrenaline (0.1â µM). The hexane extract induced a significant vasorelaxant effect in a concentration- and endothelium-dependent manner. Secondary metabolites, such as polyunsaturated fatty acids, terpenes and one flavonoid, were annotated by liquid chromatography/quadrupole time-of-flight mass spectrometry (LC/QTOF-MS) in positive ion mode. This exploratory study allowed us to identify bioactive secondary metabolites from Malvaviscus arboreus, as well as identify potentially-new vasorelaxant molecules and scaffolds for drug discovery.
Assuntos
Aorta Torácica/química , Malvaceae/química , Extratos Vegetais/metabolismo , Vasodilatadores/metabolismo , Animais , Aorta Torácica/metabolismo , Cromatografia Líquida , Masculino , Malvaceae/metabolismo , Espectrometria de Massas , Estrutura Molecular , Extratos Vegetais/análise , Ratos , Ratos Wistar , Vasodilatadores/análiseRESUMO
Perivascular adipose tissue (PVAT) modulates the vascular tone. Hydrogen sulfide (H2S) is synthetized by cystathionine gamma-lyase (CSE) in brown PVAT. Modulation of vascular contractility by H2S is, in part, adenosine triphosphate (ATP)-sensitive potassium channels dependent. However, the role of PVAT-derived H2S in hypertensive pregnancy (HTN-Preg) is unclear. Therefore, we aimed to examine the involvement of H2S in the anticontractile effect of PVAT in aortae from normotensive and hypertensive pregnant rats. To this end, phenylephrine-induced contractions in the presence and absence of PVAT and endothelium in aortae from normotensive pregnant (Norm-Preg) and HTN-Preg rats were investigated. Maternal blood pressure, fetal-placental parameters, angiogenesis-related biomarkers, and H2S levels were also assessed. We found that circulating H2S is elevated in hypertensive pregnancy associated with angiogenic imbalance, fetal and placental growth restrictions, which revealed that there is H2S pathway activation. Moreover, under stimulated H2S formation PVAT, but not endothelium, reduced phenylephrine-induced contractions in aortae from HTN-Preg rats. Also, H2S synthesis inhibitor abolished anticontractile effects of PVAT and endothelium. Furthermore, anticontractile effect of PVAT, but not of endothelium, was eliminated by ATP-sensitive potassium channels blocker. In accordance, increases in H2S levels in PVAT and placenta, but not in aortae without PVAT, were also observed. In conclusion, anticontractile effect of PVAT is lost, at least in part, in HTN-Preg aortae and PVAT effect is ATP-sensitive potassium channels dependent in normotensive and hypertensive pregnant rat aortae. PVAT but not endothelium is responsive to the H2S stimulation in hypertensive pregnant rat aortae, implying a key role for PVAT-derived H2S under endothelial dysfunction.
Assuntos
Tecido Adiposo/metabolismo , Aorta Torácica/metabolismo , Endotélio Vascular/metabolismo , Sulfeto de Hidrogênio/metabolismo , Hipertensão Induzida pela Gravidez/metabolismo , Vasoconstrição , Adaptação Fisiológica , Tecido Adiposo/fisiopatologia , Animais , Aorta Torácica/fisiopatologia , Acetato de Desoxicorticosterona , Modelos Animais de Doenças , Endotélio Vascular/fisiopatologia , Feminino , Retardo do Crescimento Fetal/metabolismo , Retardo do Crescimento Fetal/fisiopatologia , Hipertensão Induzida pela Gravidez/etiologia , Hipertensão Induzida pela Gravidez/fisiopatologia , Canais KATP/metabolismo , Gravidez , Ratos Wistar , Transdução de Sinais , Cloreto de Sódio na Dieta , Regulação para CimaRESUMO
Background: Both supraphysiological and subphysiological testosterone levels are associated with increased cardiovascular risk. Testosterone consumption at supraphysiological doses has been linked to increased blood pressure, left ventricular hypertrophy, vascular dysfunction, and increased levels of inflammatory markers. Activation of the NLRP3 inflammasome contributes to the production of proinflammatory cytokines, leading to cardiovascular dysfunction. We hypothesized that supraphysiological levels of testosterone, via generation of mitochondrial reactive oxygen species (mROS), activates the NLRP3 inflammasome and promotes vascular dysfunction. Methods: Male, 12 week-old C57Bl/6J (WT) and NLRP3 knockout (NLRP3-/-) mice were used. Mice were treated with testosterone propionate [TP (10 mg/kg) in vivo] or vehicle for 30 days. In addition, vessels were incubated with testosterone [Testo (10-6 M, 2 h) in vitro]. Testosterone levels, blood pressure, vascular function (thoracic aortic rings), pro-caspase-1/caspase-1 and interleukin-1ß (IL-1ß) expression, and generation of reactive oxygen species were determined. Results: Testosterone increased contractile responses and reduced endothelium-dependent vasodilation, both in vivo and in vitro. These effects were not observed in arteries from NLRP3-/- mice. Aortas of TP-treated WT mice (in vivo), as well as aortas from WT mice incubated with testo (in vitro), exhibited increased mROS levels and increased caspase-1 and IL-1ß expression. These effects were not observed in arteries from NLRP3-/- mice. Flutamide [Flu, 10-5 M, androgen receptor (AR) antagonist], carbonyl cyanide m-chlorophenyl hydrazone (CCCP, 10-6 M, mitochondrial uncoupler) and MCC950 (MCC950, 10-6 M, a NLRP3 receptor inhibitor) prevented testosterone-induced mROS generation. Conclusion: Supraphysiological levels of testosterone induce vascular dysfunction via mROS generation and NLRP3 inflammasome activation. These events may contribute to increased cardiovascular risk.