Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 16 de 16
Filtrar
1.
EMBO Rep ; 24(7): e56131, 2023 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-37184882

RESUMO

In addition to triggering humoral responses, conventional B cells have been described in vitro to cross-present exogenous antigens activating naïve CD8+ T cells. Nevertheless, the way B cells capture these exogenous antigens and the physiological roles of B cell-mediated cross-presentation remain poorly explored. Here, we show that B cells capture bacteria by trans-phagocytosis from previously infected dendritic cells (DC) when they are in close contact. Bacterial encounter "instructs" the B cells to acquire antigen cross-presentation abilities, in a process that involves autophagy. Bacteria-instructed B cells, henceforth referred to as BacB cells, rapidly degrade phagocytosed bacteria, process bacterial antigens and cross-prime naïve CD8+ T cells which differentiate into specific cytotoxic cells that efficiently control bacterial infections. Moreover, a proof-of-concept experiment shows that BacB cells that have captured bacteria expressing tumor antigens could be useful as novel cellular immunotherapies against cancer.


Assuntos
Linfócitos T CD8-Positivos , Células Dendríticas , Apresentação de Antígeno , Apresentação Cruzada , Antígenos de Bactérias
2.
Circulation ; 144(22): 1777-1794, 2021 11 30.
Artigo em Inglês | MEDLINE | ID: mdl-34694158

RESUMO

BACKGROUND: Hutchinson-Gilford progeria syndrome (HGPS) is a rare disorder characterized by premature aging and death mainly because of myocardial infarction, stroke, or heart failure. The disease is provoked by progerin, a variant of lamin A expressed in most differentiated cells. Patients look healthy at birth, and symptoms typically emerge in the first or second year of life. Assessing the reversibility of progerin-induced damage and the relative contribution of specific cell types is critical to determining the potential benefits of late treatment and to developing new therapies. METHODS: We used CRISPR-Cas9 technology to generate LmnaHGPSrev/HGPSrev (HGPSrev) mice engineered to ubiquitously express progerin while lacking lamin A and allowing progerin suppression and lamin A restoration in a time- and cell type-specific manner on Cre recombinase activation. We characterized the phenotype of HGPSrev mice and crossed them with Cre transgenic lines to assess the effects of suppressing progerin and restoring lamin A ubiquitously at different disease stages as well as specifically in vascular smooth muscle cells and cardiomyocytes. RESULTS: Like patients with HGPS, HGPSrev mice appear healthy at birth and progressively develop HGPS symptoms, including failure to thrive, lipodystrophy, vascular smooth muscle cell loss, vascular fibrosis, electrocardiographic anomalies, and precocious death (median lifespan of 15 months versus 26 months in wild-type controls, P<0.0001). Ubiquitous progerin suppression and lamin A restoration significantly extended lifespan when induced in 6-month-old mildly symptomatic mice and even in severely ill animals aged 13 months, although the benefit was much more pronounced on early intervention (84.5% lifespan extension in mildly symptomatic mice, P<0.0001, and 6.7% in severely ill mice, P<0.01). It is remarkable that major vascular alterations were prevented and lifespan normalized in HGPSrev mice when progerin suppression and lamin A restoration were restricted to vascular smooth muscle cells and cardiomyocytes. CONCLUSIONS: HGPSrev mice constitute a new experimental model for advancing knowledge of HGPS. Our findings suggest that it is never too late to treat HGPS, although benefit is much more pronounced when progerin is targeted in mice with mild symptoms. Despite the broad expression pattern of progerin and its deleterious effects in many organs, restricting its suppression to vascular smooth muscle cells and cardiomyocytes is sufficient to prevent vascular disease and normalize lifespan.


Assuntos
Lamina Tipo A/metabolismo , Músculo Liso Vascular/metabolismo , Miócitos Cardíacos/metabolismo , Miócitos de Músculo Liso/metabolismo , Progéria , Animais , Modelos Animais de Doenças , Humanos , Lamina Tipo A/genética , Camundongos , Camundongos Transgênicos , Progéria/genética , Progéria/metabolismo
3.
Annu Rev Physiol ; 80: 27-48, 2018 02 10.
Artigo em Inglês | MEDLINE | ID: mdl-28934587

RESUMO

Aging, the main risk factor for cardiovascular disease (CVD), is becoming progressively more prevalent in our societies. A better understanding of how aging promotes CVD is therefore urgently needed to develop new strategies to reduce disease burden. Atherosclerosis and heart failure contribute significantly to age-associated CVD-related morbimortality. CVD and aging are both accelerated in patients suffering from Hutchinson-Gilford progeria syndrome (HGPS), a rare genetic disorder caused by the prelamin A mutant progerin. Progerin causes extensive atherosclerosis and cardiac electrophysiological alterations that invariably lead to premature aging and death. This review summarizes the main structural and functional alterations to the cardiovascular system during physiological and premature aging and discusses the mechanisms underlying exaggerated CVD and aging induced by prelamin A and progerin. Because both proteins are expressed in normally aging non-HGPS individuals, and most hallmarks of normal aging occur in progeria, research on HGPS can identify mechanisms underlying physiological aging.


Assuntos
Envelhecimento/metabolismo , Doenças Cardiovasculares/metabolismo , Sistema Cardiovascular/metabolismo , Progéria/metabolismo , Calcificação Vascular/metabolismo , Animais , Doenças Cardiovasculares/fisiopatologia , Sistema Cardiovascular/fisiopatologia , Humanos , Progéria/fisiopatologia , Calcificação Vascular/fisiopatologia
4.
J Mol Cell Cardiol ; 116: 5-15, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29408196

RESUMO

Phosphorylation at serine 10 (S10) is the major posttranslational modification of the tumor suppressor p27, and is reduced in both human and mouse atherosclerosis. Moreover, a lack of p27-phospho-S10 in apolipoprotein E-null mice (apoE-/-) leads to increased high-fat diet-induced atherosclerosis associated with endothelial dysfunction and augmented leukocyte recruitment. In this study, we analyzed whether p27-phospho-S10 modulates additional endothelial functions and associated pathologies. Defective p27-phospho-S10 increases COX-2 activity in mouse aortic endothelial cells without affecting other key regulators of vascular reactivity, reduces endothelium-dependent dilation, and increases arterial contractility. Lack of p27-phospho-S10 also elevates aortic COX-2 expression and thromboxane A2 production, increases aortic lumen diameter, and aggravates angiotensin II-induced abdominal aortic aneurysm development in apoE-/- mice. All these abnormal responses linked to defective p27-phospho-S10 are blunted by pharmacological inhibition of COX-2. These results demonstrate that defective p27-phospho-S10 modifies endothelial behavior and promotes aneurysm formation via COX-2 activation.


Assuntos
Aneurisma da Aorta Abdominal/metabolismo , Aneurisma da Aorta Abdominal/fisiopatologia , Inibidor de Quinase Dependente de Ciclina p27/metabolismo , Ciclo-Oxigenase 2/metabolismo , Fosfosserina/metabolismo , Acetilcolina/farmacologia , Angiotensina II , Animais , Aorta/patologia , Pressão Sanguínea/efeitos dos fármacos , Células Endoteliais/metabolismo , Ativação Enzimática , Camundongos Endogâmicos C57BL , Fosforilação , Tromboxanos/metabolismo , Vasodilatação , Remodelação Ventricular/efeitos dos fármacos
5.
Clin Sci (Lond) ; 124(12): 719-28, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23330684

RESUMO

Increasing evidence shows that sex hormones exert a protective effect on the vasculature, especially in the regulation of the active vasomotor responses. However, whether sex hormones affect vascular remodelling is currently unclear. In the present study, we tested the hypothesis that testosterone in males and ß-oestradiol in females prevent inward remodelling, possibly through inhibition of cross-linking activity induced by enzymes of the TG (transglutaminase) family. Small mesenteric arteries were isolated from male and female Wistar rats. Dose-dependent relaxation to testosterone and ß-oestradiol was inhibited by the NO synthase inhibitor L-NAME (NG-nitro-L-arginine methyl ester), confirming that these hormones induce NO release. When arteries were cannulated, pressurized and kept in organ culture with ET-1 (endothelin-1) for 3 days we observed strong vasoconstriction and inward remodelling. Remodelling was significantly inhibited by testosterone in males, and by ß-oestradiol in females. This preventive effect of sex hormones was not observed in the presence of L-NAME. Inward remodelling was also reduced by the inhibitor of TG L682.777, both in males and females. In arteries from female rats, ET-1 increased TG activity, and this effect was prevented by ß-oestradiol. L-NAME induced a significant increase in TG activity in the presence of sex hormones in arteries from both genders. We conclude that testosterone and ß-oestradiol prevent constriction-induced inward remodelling. Inward remodelling, both in males and females, depends on NO and TG activity. In females, inhibition of inward remodelling could be mediated by NO-mediated inhibition of TG activity.


Assuntos
Estradiol/farmacologia , Artérias Mesentéricas/efeitos dos fármacos , Óxido Nítrico/metabolismo , Testosterona/farmacologia , Transglutaminases/metabolismo , Animais , Relação Dose-Resposta a Droga , Endotelina-1/farmacologia , Inibidores Enzimáticos/farmacologia , Feminino , Masculino , Artérias Mesentéricas/enzimologia , Artérias Mesentéricas/patologia , Miografia , NG-Nitroarginina Metil Éster/farmacologia , Óxido Nítrico Sintase/antagonistas & inibidores , Óxido Nítrico Sintase/metabolismo , Técnicas de Cultura de Órgãos , Ratos , Ratos Wistar , Transglutaminases/antagonistas & inibidores , Vasoconstrição/efeitos dos fármacos , Vasoconstritores/farmacologia
6.
Exp Physiol ; 96(3): 275-86, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21148625

RESUMO

Our study determines alterations in the vasoconstrictor response elicited by electric field stimulation (EFS) in mesenteric arteries from cirrhotic rats treated with CCl(4), and how calcitonin gene-related peptide (CGRP) participates in this response. Vasoconstriction induced by EFS was analysed in the absence and presence of the CGRP receptor antagonist CGRP(8-37) in arterial segments from control and cirrhotic rats. The vasodilator response to exogenous CGRP was tested in both groups of rats, and the interference of the guanylate cyclase inhibitor ODQ or the K(ATP) channel blocker glibenclamide was analysed only in segments from cirrhotic rats. The vasodilator response to the K(ATP) channel opener pinacidil and to 8-bromo-cyclic GMP was tested. The K(ATP) currents were recorded using the patch-clamp technique. Expression of receptor activity-modifying protein 1 (RAMP1), calcitonin receptor-like receptor, Kir 6.1 and sulfonylurea receptor 2B (SUR2B) was also analysed. Release of CGRP and cGMP was measured. The EFS-elicited vasoconstriction was less in segments from cirrhotic rats. The presence of CGRP(8-37) increased the EFS-induced response only in segments from cirrhotic rats. The CGRP-induced vasodilatation was greater in segments from cirrhotic rats, and was inhibited by ODQ or glibenclamide. Both pinacidil and 8-bromo-cyclic GMP induced a stronger vasodilator response in segments from cirrhotic rats. Pinacidil induced greater K(ATP) currents in cirrhotic myocytes. Expression of RAMP1, calcitonin receptor-like receptor, Kir 6.1 and SUR2B was not modified by liver cirrhosis. Liver cirrhosis increased CGRP release, but did not modify cGMP formation. The decreased vasoconstrictor response to EFS in cirrhosis is mediated by increased vasodilator response to CGRP, as well as increased K(ATP) channel gating. This effect of CGRP may play a role in the splanchnic vasodilatation present in liver cirrhosis.


Assuntos
Cirrose Hepática/fisiopatologia , Artérias Mesentéricas/efeitos dos fármacos , Artérias Mesentéricas/fisiologia , Receptores de Peptídeo Relacionado com o Gene de Calcitonina/fisiologia , Transportadores de Cassetes de Ligação de ATP/biossíntese , Transportadores de Cassetes de Ligação de ATP/genética , Animais , Peptídeo Relacionado com Gene de Calcitonina/farmacologia , Antagonistas do Receptor do Peptídeo Relacionado ao Gene de Calcitonina , Proteína Semelhante a Receptor de Calcitonina/sangue , Proteína Semelhante a Receptor de Calcitonina/genética , Tetracloreto de Carbono/farmacologia , GMP Cíclico/análogos & derivados , GMP Cíclico/metabolismo , GMP Cíclico/farmacologia , Estimulação Elétrica/métodos , Glibureto/farmacologia , Canais KATP/efeitos dos fármacos , Canais KATP/metabolismo , Canais KATP/fisiologia , Cirrose Hepática/metabolismo , Masculino , Artérias Mesentéricas/metabolismo , Células Musculares/efeitos dos fármacos , Células Musculares/metabolismo , Oxidiazóis/farmacologia , Fragmentos de Peptídeos/farmacologia , Pinacidil/farmacologia , Canais de Potássio Corretores do Fluxo de Internalização/biossíntese , Canais de Potássio Corretores do Fluxo de Internalização/genética , Quinoxalinas/farmacologia , Ratos , Ratos Sprague-Dawley , Proteína 1 Modificadora da Atividade de Receptores/biossíntese , Proteína 1 Modificadora da Atividade de Receptores/genética , Receptores de Droga/biossíntese , Receptores de Droga/genética , Receptores de Sulfonilureias , Vasoconstrição/efeitos dos fármacos , Vasodilatação/efeitos dos fármacos
7.
Cells ; 9(3)2020 03 08.
Artigo em Inglês | MEDLINE | ID: mdl-32182706

RESUMO

Cardiovascular disease (CVD) is the main cause of death worldwide, and aging is its leading risk factor. Aging is much accelerated in Hutchinson-Gilford progeria syndrome (HGPS), an ultra-rare genetic disorder provoked by the ubiquitous expression of a mutant protein called progerin. HGPS patients die in their teens, primarily due to cardiovascular complications. The primary causes of age-associated CVD are endothelial dysfunction and dysregulated vascular tone; however, their contribution to progerin-induced CVD remains poorly characterized. In the present study, we found that progeroid LmnaG609G/G609G mice with ubiquitous progerin expression show both endothelial dysfunction and severe contractile impairment. To assess the relative contribution of specific vascular cell types to these anomalies, we examined LmnaLCS/LCSTie2Cretg/+ and LmnaLCS/LCSSm22αCretg/+ mice, which express progerin specifically in endothelial cells (ECs) and vascular smooth muscle cells (VSMCs), respectively. Whereas vessel contraction was impaired in mice with VSMC-specific progerin expression, we observed no endothelial dysfunction in mice with progerin expression restricted to VSMCs or ECs. Vascular tone regulation in progeroid mice was ameliorated by dietary sodium nitrite supplementation. Our results identify VSMCs as the main cell type causing contractile impairment in a mouse model of HGPS that is ameliorated by nitrite treatment.


Assuntos
Lamina Tipo A/metabolismo , Músculo Liso Vascular/metabolismo , Nitritos/uso terapêutico , Progéria/tratamento farmacológico , Adolescente , Animais , Modelos Animais de Doenças , Humanos , Camundongos , Nitritos/farmacologia , Progéria/fisiopatologia
8.
Aging Cell ; 18(3): e12936, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30884114

RESUMO

Vascular stiffness is a major cause of cardiovascular disease during normal aging and in Hutchinson-Gilford progeria syndrome (HGPS), a rare genetic disorder caused by ubiquitous progerin expression. This mutant form of lamin A causes premature aging associated with cardiovascular alterations that lead to death at an average age of 14.6 years. We investigated the mechanisms underlying vessel stiffness in LmnaG609G/G609G mice with ubiquitous progerin expression, and tested the effect of treatment with nitrites. We also bred LmnaLCS/LCS Tie2Cre+/tg and LmnaLCS/LCS SM22αCre+/tg mice, which express progerin specifically in endothelial cells (ECs) and in vascular smooth muscle cells (VSMCs), respectively, to determine the specific contribution of each cell type to vascular pathology. We found vessel stiffness and inward remodeling in arteries of LmnaG609G/G609G and LmnaLCS/LCS SM22αCre+/tg , but not in those from LmnaLCS/LCS Tie2Cre+/tg mice. Structural alterations in aortas of progeroid mice were associated with decreased smooth muscle tissue content, increased collagen deposition, and decreased transverse waving of elastin layers in the media. Functional studies identified collagen (unlike elastin and the cytoskeleton) as an underlying cause of aortic stiffness in progeroid mice. Consistent with this, we found increased deposition of collagens III, IV, V, and XII in the media of progeroid aortas. Vessel stiffness and inward remodeling in progeroid mice were prevented by adding sodium nitrite in drinking water. In conclusion, LmnaG609G/G609G arteries exhibit stiffness and inward remodeling, mainly due to progerin-induced damage to VSMCs, which causes increased deposition of medial collagen and a secondary alteration in elastin structure. Treatment with nitrites prevents vascular stiffness in progeria.


Assuntos
Modelos Animais de Doenças , Músculo Liso Vascular/efeitos dos fármacos , Progéria/tratamento farmacológico , Progéria/genética , Nitrito de Sódio/farmacologia , Nitrito de Sódio/uso terapêutico , Rigidez Vascular/efeitos dos fármacos , Animais , Imageamento por Ressonância Magnética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Músculo Liso Vascular/metabolismo , Músculo Liso Vascular/patologia , Progéria/patologia , Nitrito de Sódio/administração & dosagem
9.
Clin Investig Arterioscler ; 30(3): 120-132, 2018.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-29602596

RESUMO

Aging is the main risk factor for cardiovascular disease (CVD). The increased prevalence of CVD is partly due to the global increase in life expectancy. In this context, it is essential to identify the mechanisms by which aging induces CVD, with the ultimate aim of reducing its incidence. Both atherosclerosis and heart failure significantly contribute to age-associated CVD morbidity and mortality. Hutchinson-Gilford progeria syndrome (HGPS) is a rare genetic disorder caused by the synthesis of progerin, which is noted for accelerated aging and CVD. This mutant form of prelamin A induces generalised atherosclerosis, vascular calcification, and cardiac electrophysiological abnormalities, leading to premature aging and death, mainly due to myocardial infarction and stroke. This review discusses the main vascular structural and functional abnormalities during physiological and premature aging, as well as the mechanisms involved in the exacerbated CVD and accelerated aging induced by the accumulation of progerin and prelamin A. Both proteins are expressed in non-HGPS individuals, and physiological aging shares many features of progeria. Research into HGPS could therefore shed light on novel mechanisms involved in the physiological aging of the cardiovascular system.


Assuntos
Envelhecimento/fisiologia , Doenças Cardiovasculares/fisiopatologia , Progéria/fisiopatologia , Fatores Etários , Doenças Cardiovasculares/epidemiologia , Doenças Cardiovasculares/etiologia , Sistema Cardiovascular/fisiopatologia , Humanos , Lamina Tipo A/metabolismo , Infarto do Miocárdio/epidemiologia , Infarto do Miocárdio/etiologia , Infarto do Miocárdio/mortalidade , Progéria/genética , Fatores de Risco , Acidente Vascular Cerebral/epidemiologia , Acidente Vascular Cerebral/etiologia , Acidente Vascular Cerebral/mortalidade
10.
PLoS One ; 12(1): e0168841, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28068359

RESUMO

Over the past few decades, the cardiovascular benefits of a high dietary intake of long-chain polyunsaturated fatty acids (PUFAs), like docosahexaenoic acid (DHA), have been extensively studied. However, many of the molecular mechanisms and effects exerted by PUFAs have yet to be well explained. The lack of sex hormones alters vascular tone, and we have described that a DHA-supplemented diet to orchidectomized rats improve vascular function of the aorta. Based on these data and since the mesenteric artery importantly controls the systemic vascular resistance, the objective of this study was to analyze the effect of a DHA-supplemented diet on the mesenteric vascular function from orchidectomized rats. For this purpose mesenteric artery segments obtained from control, orchidectomized or orchidectomized plus DHA-supplemented diet were utilized to analyze: (1) the release of prostanoids, (2) formation of NO and ROS, (3) the vasodilator response to acetylcholine (ACh), as well as the involvement of prostanoids and NO in this response, and (4) the vasoconstrictor response to electrical field stimulation (EFS), analyzing also the effect of exogenous noradrenaline (NA), and the NO donor, sodium nitroprusside (SNP). The results demonstrate beneficial effects of DHA on the vascular function in orchidectomized rats, which include a decrease in the prostanoids release and superoxide formation that were previously augmented by orchidectomy. Additionally, there was an increase in endothelial NO formation and the response to ACh, in which NO involvement and the participation of vasodilator prostanoids were increased. DHA also reversed the decrease in EFS-induced response caused by orchidectomy. All of these findings suggest beneficial effects of DHA on vascular function by reversing the neurogenic response and the endothelial dysfunction caused by orchidectomy.


Assuntos
Suplementos Nutricionais , Artérias Mesentéricas/efeitos dos fármacos , Artérias Mesentéricas/fisiopatologia , Orquiectomia , Acetilcolina/farmacologia , Animais , Pressão Sanguínea , Ácidos Docosa-Hexaenoicos/farmacologia , Masculino , Óxido Nítrico/biossíntese , Prostaglandinas/metabolismo , Ratos , Superóxidos/metabolismo , Vasodilatadores/farmacologia
11.
Methods Mol Biol ; 1339: 255-76, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26445795

RESUMO

Atherosclerosis is characterized by endothelial dysfunction and alterations in vascular reactivity, which can be investigated by wire myography. The method allows ex vivo monitoring of the transversal isometric tension developed by a vessel segment in response to different pathophysiological stimuli. Here we describe in detail how to use the wire myograph to evaluate endothelial function and vasoconstrictor or vasodilator properties of the vessel, as well as to identify and characterize different factors and molecular pathways that control vascular tone. We also describe how to use the wire myograph to analyze biomechanical and passive properties of vessels such as diameter and elasticity.


Assuntos
Artérias/fisiologia , Técnicas In Vitro , Miografia/métodos , Vasoconstrição , Vasodilatação , Animais , Artérias/efeitos dos fármacos , Fenômenos Biomecânicos , Dissecação , Elasticidade , Estimulação Elétrica , Camundongos , Miografia/instrumentação , Pressão , Processamento de Sinais Assistido por Computador , Fatores de Tempo , Rigidez Vascular , Vasoconstrição/efeitos dos fármacos , Vasoconstritores/farmacologia , Vasodilatação/efeitos dos fármacos , Vasodilatadores/farmacologia
12.
PLoS One ; 10(11): e0142039, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26540339

RESUMO

Benefits of n-3 polyunsaturated fatty acids (PUFAs) against cardiovascular diseases have been reported. Vascular tone regulation is largely mediated by endothelial factors whose release is modulated by sex hormones. Since the incidence of cardiovascular pathologies has been correlated with decreased levels of sex hormones, the aim of this study was to analyze whether a diet supplemented with the specific PUFA docosahexaenoic acid (DHA) could prevent vascular changes induced by an impaired gonadal function. For this purpose, control and orchidectomized rats were fed with a standard diet supplemented with 5% (w/w) sunflower oil or with 3% (w/w) sunflower oil plus 2% (w/w) DHA. The lipid profile, the blood pressure, the production of prostanoids and nitric oxide (NO), and the redox status of biological samples from control and orchidectomized rats, fed control or DHA-supplemented diet, were analyzed. The vasodilator response and the contribution of NO, prostanoids and hyperpolarizing mechanisms were also studied. The results showed that orchidectomy negatively affected the lipid profile, increased the production of prostanoids and reactive oxygen species (ROS), and decreased NO production and the antioxidant capacity, as well as the participation of hyperpolarizing mechanisms in the vasodilator responses. The DHA-supplemented diet of the orchidectomized rats decreased the release of prostanoids and ROS, while increasing NO production and the antioxidant capacity, and it also improved the lipid profile. Additionally, it restored the participation of hyperpolarizing mechanisms by activating potassium. Since the modifications induced by the DHA-supplemented diet were observed in the orchidectomized, but not in the healthy group, DHA seems to exert cardioprotective effects in physiopathological situations in which vascular dysfunction exists.


Assuntos
Aorta/efeitos dos fármacos , Ácidos Docosa-Hexaenoicos/farmacologia , Vasodilatação/efeitos dos fármacos , Vasodilatadores/farmacologia , Animais , Antioxidantes/metabolismo , Aorta/metabolismo , Pressão Sanguínea/efeitos dos fármacos , Dieta/métodos , Suplementos Nutricionais , Ácidos Graxos/farmacologia , Ácidos Graxos Ômega-3/farmacologia , Masculino , Óxido Nítrico/metabolismo , Orquiectomia/métodos , Óleos de Plantas/farmacologia , Prostaglandinas/metabolismo , Ratos , Ratos Sprague-Dawley , Espécies Reativas de Oxigênio/metabolismo , Óleo de Girassol
13.
PLoS One ; 9(7): e102523, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25013941

RESUMO

This study analyzes whether the release of nitric oxide (NO) and thromboxane A2 (TXA2) depends on the time lapsed since gonadal function is lost, and their correlation with the proliferation of vascular smooth muscle cells (VSMC) mediated by the epidermal growth factor receptor (EGFR). For this purpose, aortic and mesenteric artery segments from control and 6-weeks or 5-months orchidectomized rats were used to measure NO and TXA2 release. The results showed that the basal and acetylcholine (ACh)-induced NO release were decreased 6 weeks post-orchidectomy both in aorta and mesenteric artery, but were recovered 5 months thereafter up to levels similar to those found in arteries from control rats. The basal and ACh-induced TXA2 release increased in aorta and mesenteric artery 6 weeks post-orchidectomy, and was maintained at high levels 5 months thereafter. Since we previously observed that orchidectomy, which decreased testosterone level, enlarged the muscular layer of mesenteric arteries, the effect of testosterone on VSMC proliferation was analyzed. The results showed that treatment of cultured VSMC with testosterone downregulated mitogenic signaling pathways initiated by the ligand-dependent activation of the EGFR. In contrast, the EGFR pathways were constitutively active in mesenteric arteries of long-term orchidectomized rats. Thus, the exposure of mesenteric arteries from control rats to epidermal growth factor (EGF) induced the activation of EGFR signaling pathways. However, the addition of EGF to arteries from orchidectomized rats failed to induce a further activation of these pathways. In conclusion, this study shows that the release of NO depends on the time lapsed since the gonadal function is lost, while the release of TXA2 is already increased after short periods post-orchidectomy. The alterations in these signaling molecules could contribute to the constitutive activation of the EGFR and its downstream signaling pathways after long period post-orchidectomy enhancing the proliferation of the vascular muscular layer.


Assuntos
Aorta/metabolismo , Receptores ErbB/genética , Artérias Mesentéricas/metabolismo , Óxido Nítrico/metabolismo , Orquiectomia , Tromboxano A2/metabolismo , Acetilcolina/farmacologia , Animais , Aorta/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Endotélio Vascular/citologia , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/metabolismo , Fator de Crescimento Epidérmico/farmacologia , Receptores ErbB/agonistas , Receptores ErbB/metabolismo , Regulação da Expressão Gênica , Masculino , Artérias Mesentéricas/efeitos dos fármacos , Músculo Liso Vascular/citologia , Músculo Liso Vascular/efeitos dos fármacos , Músculo Liso Vascular/metabolismo , Miócitos de Músculo Liso/citologia , Miócitos de Músculo Liso/efeitos dos fármacos , Miócitos de Músculo Liso/metabolismo , Óxido Nítrico/biossíntese , Ratos , Ratos Sprague-Dawley , Transdução de Sinais , Testosterona/farmacologia , Tromboxano A2/biossíntese , Fatores de Tempo , Técnicas de Cultura de Tecidos
14.
PLoS One ; 8(9): e73474, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24058477

RESUMO

This study examines the downstream NO release pathway and the contribution of different vasodilator mediators in the acetylcholine-induced response in rat aorta 5-months after the loss of ovarian function. Aortic segments from ovariectomized and control female Sprague-Dawley rats were used to measure: the levels of superoxide anion, the superoxide dismutases (SODs) activity, the cGMP formation, the cGMP-dependent protein kinase (PKG) activity and the involvement of NO, cGMP, hydrogen peroxide and hyperpolarizing mechanisms in the ACh-induced relaxation. The results showed that ovariectomy did not alter ACh-induced relaxation; incubation with L-NAME, a NO synthase inhibitor, decreased the ACh-induced response to a lesser extent in aorta from ovariectomized than from control rats, while ODQ, a guanylate cyclase inhibitor, decreased that response to a similar extent; the blockade of hyperpolarizing mechanisms, by precontracting arteries with KCl, decreased the ACh-induced response to a greater extent in aortas from ovariectomized than those from control rats; catalase, that decomposes hydrogen peroxide, decreased the ACh-induced response only in aorta from ovariectomized rats. In addition, ovariectomy increased superoxide anion levels and SODs activity, decreased cGMP formation and increased PKG activity. Despite the increased superoxide anion and decreased cGMP in aorta from ovariectomized rats, ACh-induced relaxation is maintained by the existence of hyperpolarizing mechanisms in which hydrogen peroxide participates. The greater contribution of hydrogen peroxide in ACh-induced relaxation is due to increased SOD activity, in an attempt to compensate for increased superoxide anion formation. Increased PKG activity could represent a redundant mechanism to ensure vasodilator function in the aorta of ovariectomized rats.


Assuntos
Acetilcolina/farmacologia , Aorta/efeitos dos fármacos , Ovariectomia , Vasodilatação/efeitos dos fármacos , Vasodilatadores/farmacologia , Animais , Aorta/fisiologia , Catalase/genética , Catalase/metabolismo , Proteínas Quinases Dependentes de GMP Cíclico/genética , Proteínas Quinases Dependentes de GMP Cíclico/metabolismo , Inibidores Enzimáticos/farmacologia , Feminino , Expressão Gênica/efeitos dos fármacos , Guanilato Ciclase/genética , Guanilato Ciclase/metabolismo , Peróxido de Hidrogênio/metabolismo , NG-Nitroarginina Metil Éster/farmacologia , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase Tipo III/genética , Óxido Nítrico Sintase Tipo III/metabolismo , Oxidiazóis/farmacologia , Cloreto de Potássio/farmacologia , Quinoxalinas/farmacologia , Ratos , Ratos Sprague-Dawley , Superóxido Dismutase/genética , Superóxido Dismutase/metabolismo , Técnicas de Cultura de Tecidos
15.
Eur J Pharmacol ; 666(1-3): 142-9, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21620828

RESUMO

We evaluated the possible effects of long-term fenofibrate treatment on adrenergic, nitrergic and CGRP-ergic innervation function in mesenteric arteries from streptotozin-induced diabetic rats. We analysed the vasoconstrictor response to electrical field stimulation (EFS) and the effects of the α antagonist phentolamine, the calcitonin gene related peptide (CGRP) receptor antagonist CGRP (8-37) and the nitric oxide synthase (NOS) inhibitor L-NAME in segments from untreated and fenofibrate-treated (100 mg/kg/day) diabetic rats. The vasomotor responses to noradrenaline (NA), CGRP and the NO donor sodium nitroprusside (SNP) were analysed, and NA, CGRP, and NO releases were measured. Neuronal NOS (nNOS), phosphorylated nNOS (P-nNOS), and RAMP1 protein expression were also analysed. Fenofibrate enhanced EFS-induced contractions. Phentolamine reduced EFS-induced contractions more in segments from fenofibrate-treated than in untreated rats. Fenofibrate increased vasoconstrictor response to NA and did not modify NA release. L-NAME increased EFS-induced contractions to a higher extent in segments from fenofibrate-treated than untreated rats. Fenofibrate did not change the vasodilator response to SNP but increased EFS-induced nitric oxide release. CGRP (8-37) increased EFS-induced contractions less in segments from fenofibrate-treated rats. Fenofibrate increased the vasodilator response to CGRP and reduced CGRP release. P-nNOS and RAMP1 expression were increased in segments from fenofibrate-treated rats, while nNOS expression remained unmodified. Fenofibrate enhances the vasoconstrictor response to EFS in diabetic rats. This effect is the functional result of the modifications of at least: (i) adrenergic function, enhanced by increased sensitivity to noradrenaline; (ii) nitrergic function, enhanced by increased neuronal NO release; and (iii) CGRP function, decreased by a reduction in CGRP release.


Assuntos
Diabetes Mellitus/fisiopatologia , Fenofibrato/farmacologia , Artérias Mesentéricas/fisiopatologia , Neurônios/efeitos dos fármacos , Neurotransmissores/metabolismo , Vasoconstrição/efeitos dos fármacos , Animais , Peso Corporal/efeitos dos fármacos , Peptídeo Relacionado com Gene de Calcitonina/metabolismo , Diabetes Mellitus/enzimologia , Diabetes Mellitus/metabolismo , Diabetes Mellitus/patologia , Estimulação Elétrica , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Masculino , Artérias Mesentéricas/efeitos dos fármacos , Neurônios/metabolismo , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase Tipo I/metabolismo , Norepinefrina/metabolismo , Fosfoproteínas/metabolismo , Ratos , Ratos Sprague-Dawley , Proteína 1 Modificadora da Atividade de Receptores/metabolismo , Fatores de Tempo , Sistema Vasomotor/efeitos dos fármacos , Sistema Vasomotor/fisiopatologia
16.
J Hypertens ; 27(4): 791-9, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19516178

RESUMO

OBJECTIVES: To investigate whether hypertension could modify the function of adrenergic, nitrergic, and sensory innervations involved in the electrical field stimulation-induced response in mesenteric arteries from female rats. METHODS: Vascular reactivity experiments were performed in endothelium-denuded mesenteric arteries from normotensive, Wistar-Kyoto and spontaneously hypertensive female rats; protein expression was measured by western blot; nitric oxide release was measured by fluorometry; calcitonin gene-related peptide and noradrenaline release were determined by enzyme immunoassay. RESULTS: The electrical field stimulation-induced contractions were significantly lower in segments from spontaneously hypertensive rats than those of Wistar-Kyoto rats. Hypertension did not modify either the response or release of noradrenaline. Preincubation with the nitric oxide synthase inhibitor N(G)-nitro-L-arginine methyl ester increased the electrical field stimulation-induced contractions only in segments from Wistar-Kyoto rats. The relaxation induced by the nitric oxide donor sodium nitroprusside was similar in segments from both strains. The electrical field stimulation-induced nitric oxide release was decreased in segments from spontaneously hypertensive rats. The calcitonin gene-related peptide receptor antagonist CGRP(8-37) did not alter the electrical field stimulation-induced contractions in segments from Wistar-Kyoto rats but increased them in segments from spontaneously hypertensive rats. The calcitonin gene-related peptide-induced relaxation was increased in segments from spontaneously hypertensive rats. The expression of the 15-kDa active form of RAMP1 was increased in segments from spontaneously hypertensive rats. CONCLUSION: In contrast to male rats, electrical field stimulation-induced contractions are decreased in hypertensive female rats. Nitrergic innervation plays a role in the development and/or maintenance of hypertension, whereas sensory innervation is a counteracting mechanism through the increased calcitonin gene-related peptide response.


Assuntos
Peptídeo Relacionado com Gene de Calcitonina/fisiologia , Hipertensão/fisiopatologia , Artérias Mesentéricas/inervação , Óxido Nítrico/fisiologia , Norepinefrina/fisiologia , Animais , Relação Dose-Resposta a Droga , Estimulação Elétrica , Feminino , Peptídeos e Proteínas de Sinalização Intracelular/análise , Masculino , Proteínas de Membrana/análise , Artérias Mesentéricas/fisiologia , NG-Nitroarginina Metil Éster/farmacologia , Ratos , Ratos Endogâmicos SHR , Ratos Endogâmicos WKY , Proteínas Modificadoras da Atividade de Receptores , Caracteres Sexuais , Vasoconstrição/efeitos dos fármacos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA