RESUMO
AIMS: Aldosterone has been found to influence cancer cell growth, cell cycle regulation and cell migration, including in prostate cancer cells. Spironolactone is an aldosterone antagonist used for managing chronic heart failure (HF) with known antiandrogenic effects. We examined the effect of spironolactone exposure amongst men with HF on the incidence of prostate cancer. METHODS: This retrospective cohort study utilized provincial clinical and administrative databases from the Manitoba Centre for Health Policy. Incident cases of prostate cancer were identified from the provincial cancer registry, and spironolactone exposure was quantified from pharmacare databases. A multivariable proportional hazards model was used to assess the time-dependent impact of spironolactone exposure on prostate cancer incidence. RESULTS: A total of 18 562 men with newly diagnosed HF from 2007 to 2015 with a median age of 72 years (interquartile range: 61-81) and a median follow-up from HF diagnosis to prostate cancer incidence of 2.7 years (interquartile range: 1.1-4.9) were included. A time-dependent multivariable analysis of spironolactone exposure following HF diagnosis found a reduced the risk of prostate cancer hazard ratio 0.55 (95% confidence interval 0.31-0.98, P = .043). CONCLUSION: Spironolactone exposure significantly reduced the incidence of prostate cancer amongst men with HF. These findings support the plausibility of aldosterone as a promoter of prostate cancer growth and development. Prospective clinical trials are warranted to further assess the role of spironolactone or other mineralocorticoid receptor antagonists as a means to prevent prostate cancer development or as an adjunctive measure to prostate cancer treatments.
Assuntos
Insuficiência Cardíaca , Neoplasias da Próstata , Idoso , Idoso de 80 Anos ou mais , Insuficiência Cardíaca/epidemiologia , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Antagonistas de Receptores de Mineralocorticoides/efeitos adversos , Estudos Prospectivos , Neoplasias da Próstata/epidemiologia , Estudos Retrospectivos , Espironolactona/efeitos adversos , Resultado do TratamentoRESUMO
Although the rapid effects of steroids, such as estrogen and aldosterone, were postulated originally to be nongenomic, it is now appreciated that activation of such signaling pathways via a steroid-acting G protein-coupled receptor, the G protein estrogen receptor (GPER), has important transcription-dependent outcomes in the regulation of cell growth and programmed cell death secondary to GPER-regulated second-messenger pathways. GPER is expressed ubiquitously and has diverse biological effects, including regulation of endocrine, immune, neuronal, and cardiovascular functions. Perhaps the most biologically important consequences of GPER activation are the regulation of cell growth, migration, and apoptotic cell death. These cell growth regulatory effects, important in cancer biology, are also relevant in the regulation of cardiac and vascular hypertrophy and in the response to ischemia. This review provides a summary of relevant findings of the impact of GPER regulation by either estradiol or aldosterone in in vitro model systems and extends those findings to in vivo studies of direct clinical relevance for development of GPER-directed agents for treatment of cancer and cardiovascular diseases associated with cellular proliferation.
Assuntos
Aldosterona/metabolismo , Doenças Cardiovasculares/metabolismo , Estradiol/metabolismo , Neoplasias/metabolismo , Receptores de Estrogênio/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Aldosterona/farmacologia , Aldosterona/uso terapêutico , Animais , Doenças Cardiovasculares/tratamento farmacológico , Morte Celular/efeitos dos fármacos , Morte Celular/fisiologia , Estradiol/farmacologia , Estradiol/uso terapêutico , Hormônios Esteroides Gonadais/metabolismo , Hormônios Esteroides Gonadais/farmacologia , Hormônios Esteroides Gonadais/uso terapêutico , Humanos , Neoplasias/tratamento farmacológicoRESUMO
The mineralocorticoid aldosterone is a key regulator of water and electrolyte homeostasis. Numerous recent developments have advanced the field of mineralocorticoid pharmacologynamely, clinical trials have shown the beneficial effects of aldosterone antagonists in chronic heart failure and post-myocardial infarction treatment. Experimental studies using cell type-specific gene targeting of the mineralocorticoid receptor (MR) gene in mice have revealed the importance of extrarenal aldosterone signaling in cardiac myocytes, endothelial cells, vascular smooth cells, and macrophages. In addition, several molecular pathways involving signal transduction via the classical MR as well as the G protein-coupled receptor GPER mediate the diverse spectrum of effects of aldosterone on cells. This knowledge has initiated the development of new pharmacological ligands to specifically interfere with targets on different levels of aldosterone signaling. For example, aldosterone synthase inhibitors such as LCI699 and the novel nonsteroidal MR antagonist BAY 94-8862 have been tested in clinical trials. Interference with the interaction between MR and its coregulators seems to be a promising strategy toward the development of selective MR modulators.
Assuntos
Aldosterona/metabolismo , Vasos Sanguíneos/metabolismo , Doenças Cardiovasculares/metabolismo , Miocárdio/metabolismo , Receptores de Mineralocorticoides/metabolismo , Animais , Vasos Sanguíneos/efeitos dos fármacos , Vasos Sanguíneos/fisiopatologia , Doenças Cardiovasculares/tratamento farmacológico , Doenças Cardiovasculares/fisiopatologia , Desenho de Fármacos , Humanos , Antagonistas de Receptores de Mineralocorticoides/farmacologia , Terapia de Alvo Molecular , Receptores de Mineralocorticoides/efeitos dos fármacos , Transdução de SinaisRESUMO
Although aldosterone is a known regulator of renal and cardiovascular function, its role as a regulator of cancer growth and spread has not been widely considered. This study tested the hypothesis that aldosterone regulates cancer cell growth/spread via G protein-coupled estrogen receptor (GPER) activation. In vitro in murine renal cortical adenocarcinoma (RENCA) cells, a widely used murine in vitro model for the study of renal cell adenocarcinoma, aldosterone increased RENCA cell proliferation to a maximum of 125 ± 3% of control at a concentration of 10 nM, an effect blocked by the GPER antagonist G15 or by GPER knockdown using short interfering (sh) RNA techniques. Further, aldosterone increased RENCA cell migration to a maximum of 170 ± 20% of control at a concentration of 100 nM, an effect also blocked by G15 or by GPER down-regulation. In vivo, after orthotopic RENCA cell renal transplantation, pulmonary tumor spread was inhibited by pharmacologic blockade of aldosterone effects with spironolactone (percentage of lung occupied by metastasis: control = 68 ± 13, spironolactone = 26 ± 8, P < 0.05) or inhibition of aldosterone synthesis with a high dietary salt diet (percentage of lung: control = 44 ± 6, high salt = 12 ± 3, P < 0.05), without reducing primary tumor size. Additionally, adrenalectomy significantly reduced the extent of pulmonary tumor spread, whereas aldosterone infusion recovered pulmonary metastatic spread toward baseline levels. Finally, inhibition of GPER either with the GPER antagonist G15 or by GPER knockdown comparably inhibited RENCA cell pulmonary metastatic cancer spread. Taken together, these findings provide strong evidence for aldosterone serving a causal role in renal cell cancer regulation via its GPER receptor; thus, antagonism of GPER represents a potential new target for treatment to reduce metastatic spread.-Feldman, R. D., Ding, Q., Hussain, Y., Limbird, L. E., Pickering, J. G., Gros, R. Aldosterone mediates metastatic spread of renal cancer via the G protein-coupled estrogen receptor (GPER).
Assuntos
Aldosterona/metabolismo , Regulação Neoplásica da Expressão Gênica/fisiologia , Neoplasias Renais/metabolismo , Metástase Neoplásica/fisiopatologia , Neoplasias Experimentais/metabolismo , Receptores de Estrogênio/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Aldosterona/genética , Animais , Linhagem Celular Tumoral , Regulação para Baixo , Neoplasias Renais/patologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Antagonistas de Receptores de Mineralocorticoides/farmacologia , Interferência de RNA , RNA Interferente Pequeno , Receptores de Estrogênio/genética , Receptores Acoplados a Proteínas G/genética , Espironolactona/farmacologiaRESUMO
OBJECTIVE: Estrogen deficiency is linked with increased low-density lipoprotein (LDL) cholesterol. The hormone receptor mediating this effect is unknown. G-protein estrogen receptor (GPER) is a recently recognized G-protein-coupled receptor that is activated by estrogens. We recently identified a common hypofunctional missense variant of GPER, namely P16L. However, the role of GPER in LDL metabolism is unknown. Therefore, we examined the association of the P16L genotype with plasma LDL cholesterol level. Furthermore, we studied the role of GPER in regulating expression of the LDL receptor and proprotein convertase subtilisin kexin type 9. APPROACH AND RESULTS: Our discovery cohort was a genetically isolated population of Northern European descent, and our validation cohort consisted of normal, healthy women aged 18 to 56 years from London, Ontario. In addition, we examined the effect of GPER on the regulation of proprotein convertase subtilisin kexin type 9 and LDL receptor expression by the treatment with the GPER agonist, G1. In the discovery cohort, GPER P16L genotype was associated with a significant increase in LDL cholesterol (mean±SEM): 3.18±0.05, 3.25±0.08, and 4.25±0.33 mmol/L, respectively, in subjects with CC (homozygous for P16), CT (heterozygotes), and TT (homozygous for L16) genotypes (P<0.05). In the validation cohort (n=339), the GPER P16L genotype was associated with a similar increase in LDL cholesterol: 2.17±0.05, 2.34±0.06, and 2.42±0.16 mmol/L, respectively, in subjects with CC, CT, and TT genotypes (P<0.05). In the human hepatic carcinoma cell line, the GPER agonist, G1, mediated a concentration-dependent increase in LDL receptor expression, blocked by either pretreatment with the GPER antagonist G15 or by shRNA-mediated GPER downregulation. G1 also mediated a GPER- and concentration-dependent decrease in proprotein convertase subtilisin kexin type 9 expression. CONCLUSIONS: GPER activation upregulates LDL receptor expression, probably at least, in part, via proprotein convertase subtilisin kexin type 9 downregulation. Furthermore, humans carrying the hypofunctional P16L genetic variant of GPER have increased plasma LDL cholesterol. In aggregate, these data suggest an important role of GPER in the regulation of LDL receptor expression and consequently LDL metabolism.
Assuntos
LDL-Colesterol/sangue , Mutação de Sentido Incorreto , Receptores de Estrogênio/genética , Receptores de Estrogênio/metabolismo , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/metabolismo , Adolescente , Adulto , Idoso , Canadá , Relação Dose-Resposta a Droga , Feminino , Regulação da Expressão Gênica , Frequência do Gene , Genética Populacional , Células Hep G2 , Heterozigoto , Homozigoto , Humanos , Masculino , Pessoa de Meia-Idade , Fenótipo , Pró-Proteína Convertase 9 , Pró-Proteína Convertases/genética , Pró-Proteína Convertases/metabolismo , Interferência de RNA , Receptores de Estrogênio/efeitos dos fármacos , Receptores Acoplados a Proteínas G/efeitos dos fármacos , Receptores de LDL/genética , Receptores de LDL/metabolismo , Serina Endopeptidases/genética , Serina Endopeptidases/metabolismo , Transfecção , População Branca/genética , Adulto JovemRESUMO
Heart disease in women remains underappreciated, underdiagnosed and undertreated. Further, although we are starting to understand some of the social and behavioral determinants for this, the biological basis for the increased rate of rise in atherosclerosis risk in women after menopause remains very poorly understand. In this review we will outline the scope of the clinical issues related to heart disease in women, the emerging findings regarding the biological basis underlying the increased prevalence of atherosclerotic risk factors in postmenopausal women (vs. men) and the role of the G protein-coupled estrogen receptor (GPER) and its genetic regulation as a determinant of these sex-specific risks. GPER is a recently appreciated GPCR that mediates the rapid effects of estrogen and aldosterone. Recent studies have identified that GPER activation regulates both blood pressure. We have shown that regulation of GPER function via expression of a hypofunctional GPER genetic variant is an important determinant of blood pressure and risk of hypertension in women. Further, our most recent studies have identified that GPER activation is an important regulator of low density lipoprotein (LDL) receptor metabolism and that expression of the hypofunctional GPER genetic variant is an important contributor to the development of hypercholesterolemia in women. GPER appears to be an important determinant of the two major risk factors for coronary artery disease-blood pressure and LDL cholesterol. Further, the importance of this mechanism appears to be greater in women. Thus, the appreciation of the role of GPER function as a determinant of the progression of atherosclerotic disease may be important both in our understanding of cardiometabolic function but also in opening the way to greater appreciation of the sex-specific regulation of atherosclerotic risk factors.
Assuntos
Cardiopatias/genética , Cardiopatias/patologia , Receptores de Estrogênio/genética , Receptores Acoplados a Proteínas G/genética , Feminino , Regulação da Expressão Gênica , Predisposição Genética para Doença , Cardiopatias/tratamento farmacológico , Cardiopatias/metabolismo , Humanos , Hipertensão/genética , Terapia de Alvo Molecular , Pós-Menopausa , Receptores de Estrogênio/antagonistas & inibidores , Receptores Acoplados a Proteínas G/antagonistas & inibidores , Receptores de LDL/metabolismo , Fatores de RiscoRESUMO
AIMS: Activation of vascular GPER has been linked to vasodepressor effects in animals. However, the significance of GPER regulation on chronic blood pressure control in humans is unknown. METHODS: To examine this question we determined the functional significance of expression of a common missense single nucleotide variant of GPER, P16L in vascular smooth muscle cells, and its association with blood pressure in humans. Further, to validate the importance of carrying GPER P16L in the development of hypertension we assessed allele frequency in a cohort of hard-to-treat hypertensive patients referred to a tertiary care clinic. RESULTS: Expression of the GPER P16L variant (V) vs. wild type (WT) in rat aortic vascular smooth muscle cells, was associated with a significant decrease in G1 (1 µm, a GPER agonist)-mediated ERK phosphorylation (slope of the function of G1-stimulated ERK phosphorylation: GPER content WT: 16.2, 95% CI 9.9, 22.6; V: 5.0, 95% CI 1.0, 9.0; P < 0.005) and apoptosis (slope of the function of G1-stimulated apoptosis: GPER content: WT: 4.4, 95% CI: 3.4, 5.4; V: 2.5, 95% CI 1.6, 2.3 P < 0.005). Normotensive female subjects, but not male subjects, carrying this hypofunctional variant (allele frequency 22%) have increased blood pressure [mean arterial pressure: P16/P16: 80 ± 1 mmHg (n = 204) vs.â P16L carriers: 82 ± 1 mmHg (n = 127), 95% CI for difference: 0.6, 4.0 mmHg, P < 0.05], [systolic blood pressure: P16/P16: 105 ± 1 mmHg vs. P16L carriers: 108 ± 1 mmHg, 95% CI for difference:1.0, 5.1 mmHg, P < 0.05], [diastolic blood pressure: P16/P16: 66 ± 0.5 mmHg vs. P16L carriers 68 ± 0.7, 95% CI for difference: 0.2, 3.6 mmHg, P < 0.05]. Further, the P16L allele frequency was almost two-fold higher in female vs. male hypertensive patients (31% vs. 16%, allele ratio 0.5, 95% CI 0.32, 0.76, P < 0.05). CONCLUSIONS: The common genetic variant, GPER P16L, is hypofunctional and female carriers of this allele have increased blood pressure. There was an increased prevalence in a population of hard-to-treat hypertensive female patients. Cumulatively, these data suggest that in females, impaired GPER function might be associated with increased blood pressure and risk of hypertension.
Assuntos
Hipertensão/genética , Receptores de Estrogênio/genética , Receptores Acoplados a Proteínas G/genética , Adolescente , Adulto , Animais , Apoptose , Células Cultivadas , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Feminino , Frequência do Gene , Variação Genética , Humanos , Hipertensão/etiologia , Masculino , Fosforilação , Ratos , Caracteres SexuaisRESUMO
The importance of the rapid vascular effects of aldosterone is increasingly appreciated. Through these rapid pathways, aldosterone has been shown to regulate vascular contractility, cell growth, and apoptosis. In our most recent studies, we demonstrated the effects of aldosterone on cell growth and contractility in vascular smooth muscle cells. We showed that these effects could occur via activation of the classic mineralocorticoid receptor, as well the recently characterized G protein-coupled estrogen receptor (GPER), initially characterized as an estrogen-specific receptor. However, the mechanisms underlying aldosterone's endothelium-dependent actions are unknown. Furthermore, the ERK regulatory and proapoptotic effects of aldosterone mediated by GPER activation in cultured vascular smooth muscle cells were only apparent when GPER was reintroduced into these cells by gene transfer. Whether GPER activation via aldosterone might be an important regulator in native vascular cells has been questioned. Therefore, to determine the role of GPER in mediating aldosterone's effects on cell growth and vascular reactivity in native cells, we examined rat aortic vascular endothelial cells, a model characterized by persistent robust expression of GPER, but without detectable mineralocorticoid receptor expression. In these endothelial cells, the GPER agonist G1 mediates a rapid increase in ERK phosphorylation that is wholly GPER-dependent, paralleling the actions of aldosterone. The effects of G1 and aldosterone to stimulate ERK phosphorylation paralleled their proapoptotic and antiproliferative effects. In previous studies, we reported that aldosterone mediates a rapid endothelium-dependent vasodilatory effect, antagonistic to its direct vasoconstrictor effect in endothelium-denuded preparations. Using a rat aortic ring/organ bath preparation to determine the GPER dependence of aldosterone's endothelium-dependent vasodilator effects, we demonstrate that aldosterone inhibits phenylephrine-mediated contraction. This vasodilator effect parallels the actions of the GPER agonist G1. Furthermore, the effects of aldosterone were completely ablated by the GPER antagonist G15. These data support an important role of GPER activation in aldosterone-mediated regulation of endothelial cell growth, as well as in aldosterone's endothelium-mediated regulation of vasoreactivity.
Assuntos
Aldosterona/metabolismo , Células Endoteliais/fisiologia , Músculo Liso Vascular/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Receptores de Mineralocorticoides/metabolismo , Animais , Aorta/metabolismo , Aorta/fisiologia , Apoptose/efeitos dos fármacos , Cardiotônicos/farmacologia , Proliferação de Células/efeitos dos fármacos , Fatores Relaxantes Dependentes do Endotélio/metabolismo , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Técnicas de Transferência de Genes , Antagonistas de Receptores de Mineralocorticoides , Músculo Liso Vascular/efeitos dos fármacos , Músculo Liso Vascular/fisiologia , Fenilefrina/farmacologia , Fosforilação , Ratos , Receptores de Estrogênio/genética , Receptores de Estrogênio/metabolismo , Receptores Acoplados a Proteínas G/genética , Transdução de Sinais/efeitos dos fármacos , Vasoconstrição/fisiologia , Vasoconstritores/farmacologia , Vasodilatação/fisiologiaRESUMO
Aldosterone has actions far beyond its role as a renal regulator of sodium reabsorption, and broader mechanisms of action than simply a transcriptional regulator. Aldosterone has a number of vascular effects, including regulation of vascular reactivity and vascular growth and/or development. Aldosterone-mediated effects on vascular reactivity reflect a balance between its endothelial-dependent vasodilator effects and its direct smooth muscle vasoconstrictor effects. The endothelial vasodilator effects of aldosterone are mediated by phosphatidylinositol 3-kinase-dependent activation of nitric oxide synthase. G-Protein oestrogen receptor (GPER) is a recently recognized G-protein coupled receptor (GPCR) that is activated by steroid hormones. It was first recognized as the GPCR mediating the rapid effects of oestrogens. Activation of GPER also mediates at least some of the vascular effects of aldosterone in smooth muscle and endothelial cells. In vascular endothelial cells, aldosterone activation of GPER mediates vasodilation. In contrast, activation of endothelial mineralocorticoid receptors has been linked to enhanced vasoconstrictor and/or impaired vasodilator responses.
Assuntos
Aldosterona/fisiologia , Endotélio Vascular/metabolismo , Músculo Liso Vascular/metabolismo , Receptores de Estrogênio/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Receptores de Mineralocorticoides/metabolismo , Aldosterona/metabolismo , Endotélio Vascular/fisiopatologia , Humanos , Ligantes , Músculo Liso Vascular/fisiopatologia , Vasoconstrição/fisiologia , Vasodilatação/fisiologiaRESUMO
Aldosterone was initially identified as a hormone primarily related to regulation of fluid and electrolyte homeostasis. However, over the past 20 years there has been an increasing appreciation of its role in regulation of vascular function and pathophysiology in the setting of hypertension, atherosclerosis, and heart failure. This review highlights recent advances in our understanding the biology of aldosterone as it relates to the pathophysiology and the management of vascular disease-especially related to hypertension. The review focuses on 3 key areas: 1) advances in our understanding of the cellular mechanisms by which aldosterone mediates its cellular effects, 2) identification of the hidden epidemic of aldosteronism as a mediator of hypertension, and 3) appreciating new therapeutic advances in the clinical pharmacology of aldosterone inhibition in cardiovascular and renal disease.
Assuntos
Sistema Cardiovascular , Insuficiência Cardíaca , Hiperaldosteronismo , Hipertensão , Humanos , Aldosterona , Hipertensão/tratamento farmacológico , Insuficiência Cardíaca/tratamento farmacológico , Antagonistas de Receptores de Mineralocorticoides/uso terapêuticoRESUMO
Aldosterone exerts some of its effects not by binding to mineralocorticoid receptors, but rather by acting via G protein-coupled estrogen receptors (GPER). To determine if aldosterone binds directly to GPER, we studied the ability of aldosterone to compete for the binding of [3 H] 2-methoxyestradiol ([3 H] 2-ME), a high potency GPER-selective agonist. We used GPER gene transfer to engineer Sf9-cultured insect cells to express GPER. We chose insect cells to avoid interactions with any intrinsic mammalian receptors for aldosterone. [3 H] 2-ME binding was saturable and reversible to a high-affinity population of receptors with Kd = 3.7 nM and Bmax = 2.2 pmol/mg. Consistent with agonist binding to G Protein-coupled receptors, [3 H] 2-ME high-affinity state binding was reduced in the presence of the hydrolysis-resistant GTP analog, GppNHp. [3 H] 2-ME binding was competed for by the GPER agonist G1, the GPER antagonist G15, estradiol (E2), as well as aldosterone (Aldo). The order of potency for competing for [3 H] 2-ME binding, namely 2ME > Aldo > E2 ≥ G1, paralleled the orders of potency for inhibition of cell proliferation and inhibition of ERK phosphorylation by ligands acting at GPER. These data confirm the ability of aldosterone to interact with the GPER, consistent with the interpretation that aldosterone likely mediates its GPER-dependent effects by direct binding to the GPER. SIGNIFICANCE STATEMENT: Despite the growing evidence for aldosterone's actions via G protein-coupled estrogen receptors (GPER), there remains significant skepticism that aldosterone can directly interact with GPER. The current studies are the first to demonstrate directly that aldosterone indeed is capable of binding to the GPER and thus likely mediates its GPER-dependent effects by direct binding to the receptor.
Assuntos
Aldosterona , Receptores de Estrogênio , Aldosterona/metabolismo , Animais , Estrogênios , Proteínas de Ligação ao GTP/metabolismo , Mamíferos/metabolismo , Mercaptoetanol , Receptores Acoplados a Proteínas G/metabolismoRESUMO
beta-Arrestins are important in chemoattractant receptor-induced granule release, a process that may involve Ral-dependent regulation of the actin cytoskeleton. We have identified the Ral GDP dissociation stimulator (Ral-GDS) as a beta-arrestin-binding protein by yeast two-hybrid screening and co-immunoprecipitation from human polymorphonuclear neutrophilic leukocytes (PMNs). Under basal conditions, Ral-GDS is localized to the cytosol and remains inactive in a complex formed with beta-arrestins. In response to formyl-Met-Leu-Phe (fMLP) receptor stimulation, beta-arrestin Ral-GDS protein complexes dissociate and Ral-GDS translocates with beta-arrestin from the cytosol to the plasma membrane, resulting in the Ras-independent activation of the Ral effector pathway required for cytoskeletal rearrangement. The subsequent re-association of beta-arrestin Ral-GDS complexes is associated with the inactivation of Ral signalling. Thus, beta-arrestins regulate multiple steps in the Ral-dependent processes that result in chemoattractant-induced cytoskeletal reorganization.
Assuntos
Arrestinas/metabolismo , Citoesqueleto/metabolismo , Proteínas ral de Ligação ao GTP/metabolismo , Fator ral de Troca do Nucleotídeo Guanina/metabolismo , Animais , Arrestinas/química , Transporte Biológico Ativo , Células COS , Linhagem Celular , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Citoesqueleto/efeitos dos fármacos , Guanosina 5'-O-(3-Tiotrifosfato)/metabolismo , Humanos , Substâncias Macromoleculares , Modelos Biológicos , N-Formilmetionina Leucil-Fenilalanina/farmacologia , Neutrófilos/efeitos dos fármacos , Neutrófilos/metabolismo , Ratos , Receptores de Formil Peptídeo , Receptores Imunológicos/metabolismo , Receptores de Peptídeos/metabolismo , Transdução de Sinais , Técnicas do Sistema de Duplo-Híbrido , beta-Arrestinas , Proteínas ral de Ligação ao GTP/química , Fator ral de Troca do Nucleotídeo Guanina/químicaRESUMO
It is increasingly appreciated that steroid hormones such as aldosterone and estradiol can mediate important cardiovascular effects. Many of these effects occur over a time course not consistent with the genomic actions of these hormones acting through classical nuclear receptors / transcription factors. Further, multiple receptors have been implicated in mediating these rapid effects of both aldosterone and estradiol, including a newly appreciated G-protein-coupled receptor, GPR30. In previous studies we demonstrated that both aldosterone and estradiol mediate contraction in vascular smooth muscle cells, as assessed in single cell assays. However, the receptor mechanisms underlying these effects remained unclear. Therefore, we studied the actions of estradiol and aldosterone on rat aortic vascular smooth muscle cells. Both aldosterone and estradiol mediated a concentration-dependent increase in contraction, as assessed in substrate deformation assays with EC(50)s in the range of nanomoles per litre. These effects paralleled increased myosin light chain phosphorylation. The effects of aldosterone were inhibited by the mineralocorticoid selective antagonist eplerenone. Further, aldosterone's contractile effects were enhanced by increased expression of the mineralocorticoid receptor. The contractile effects of estradiol were inhibited by estrogen receptor (ER)-selective antagonists, tamoxifen, and ICI 182780, as well as eplerenone. Further, estradiol's effects were enhanced by the increased expression of both ERα and the mineralocorticoid receptor (MR). To assess the potential role of GPR30 in mediating the effects of aldosterone and estradiol, GPR30 was re-introduced, since these cells lose endogenous GPR30 expression in culture. Re-expression of GPR30 enhanced both estradiol- and aldosterone-mediated contraction. These studies demonstrate that in rat aortic vascular smooth muscle cells, both aldosterone and estradiol mediate vascular smooth muscle contraction and that these effects can be mediated by MR, ERα, and by GPR30.
Assuntos
Aldosterona/farmacologia , Estradiol/farmacologia , Músculo Liso Vascular/efeitos dos fármacos , Músculo Liso Vascular/metabolismo , Miócitos de Músculo Liso/efeitos dos fármacos , Miócitos de Músculo Liso/metabolismo , Vasoconstrição/efeitos dos fármacos , Animais , Células Cultivadas , Eplerenona , Receptor alfa de Estrogênio/genética , Receptor alfa de Estrogênio/metabolismo , Contração Muscular/efeitos dos fármacos , Contração Muscular/genética , Cadeias Leves de Miosina/metabolismo , Fosforilação/efeitos dos fármacos , Ratos , Ratos Endogâmicos WKY , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/metabolismo , Receptores de Mineralocorticoides/genética , Receptores de Mineralocorticoides/metabolismo , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Espironolactona/análogos & derivados , Espironolactona/farmacologia , Tamoxifeno/farmacologia , Vasoconstrição/genéticaRESUMO
Adenylyl cyclase (ADCY) is a critical regulator of metabolic and cardiovascular function. We have identified a genetic variant (A674S) in ADCY isoform 6 (ADCY6). Subsequent studies demonstrated that the expression of this ADCY6 variant paralleled an increase in adenylyl cyclase-mediated functions. However, the impact of this hyperfunctional variant on cardiovascular function is unknown. Therefore, we evaluated the hemodynamic profile of carriers of ADCY6 A674S. The association of ADCY6 A674S with anthropometric and hemodynamic parameters was assessed in 364 healthy white subjects. The allele encoding this variant was present in 6.9% of the subjects, and those individuals had increased blood pressure. To determine the hemodynamic basis for increased blood pressure in carriers of ADCY6 A674S, we assessed forearm blood flow (FBF) and cardiac output at rest, during handgrip exercise (to test vasodilator responsiveness), and with lower body negative pressure [to test forearm vasoconstrictor and heart rate (HR) responsiveness] in a subsample of 21 subjects. At rest, cardiac output and blood pressure were higher in carriers of ADCY6 A674S. This was paralleled by an increase in plasma renin activity, but not in plasma norepinephrine. During handgrip exercise, FBF and vasodilator responses were greater in carriers of ADCY6 A674S. Responses to reactive hyperemia were not different between genotypes. With lower body negative pressure, the HR response to this orthostatic stress was markedly higher in carriers of ADCY6 A674S. These data indicate that the relatively common hyperfunctional ADCY6 A674S variant underlies a hyperdynamic cardiovascular response and increased blood pressure.
Assuntos
Adenilil Ciclases/genética , Pressão Sanguínea/genética , Fenômenos Fisiológicos Cardiovasculares/genética , Variação Genética , Adolescente , Adulto , Antropometria , Débito Cardíaco/genética , Exercício Físico , Antebraço/irrigação sanguínea , Frequência do Gene , Genótipo , Frequência Cardíaca/genética , Humanos , Pressão Negativa da Região Corporal Inferior , Pessoa de Meia-Idade , Fluxo Sanguíneo Regional/genética , Vasoconstrição/genética , Vasodilatação/genética , Adulto JovemRESUMO
PURPOSE OF REVIEW: To critically examine the scientific basis of emerging concepts in the monitoring and treatment of hypertension. RECENT FINDINGS: Effective targeting of treatment strategies requires accurate assessment of blood pressure. Isolated use of manual office blood pressure measurement cannot detect white coat or masked hypertension. New information comparing automated office blood pressure (AOBP) to ambulatory blood pressure monitoring (ABPM) demonstrates that AOBP can minimize occurrence of white coat hypertension. From the public health perspective, reduction in salt consumption may be the single most important intervention, and could have a very significant impact on hypertension control. Further salt restriction strategies are effective means to decrease blood pressure even in patients with resistant hypertension. Provision of pharmacotherapy as single pill combinations is more effective than multiple drugs provided as monotherapy. From the hypertension practitioner perspective, complex choices are simplified, thus reducing therapeutic inertia. From the patient perspective, therapeutic turbulence is reduced and adherence to therapy increased. Combinations studied include thiazide diuretics with an inhibitor of the angiotensin system and the combination of amlodipine with angiotensin-converting enzyme (ACE) inhibitor. Amlodipine-based combinations are emerging as a valuable tool in the management of hypertension. SUMMARY: Progress in the monitoring of blood pressure, understanding of the public health benefits of more aggressive efforts to reduce dietary sodium intake and use of simplified algorithms featuring the use of low-dose single pill combinations will be expected to improve blood pressure control and reduce hypertension-related complications.
Assuntos
Anti-Hipertensivos/uso terapêutico , Dieta Hipossódica , Hipertensão/dietoterapia , Sódio na Dieta , Bloqueadores do Receptor Tipo 1 de Angiotensina II/uso terapêutico , Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Anti-Hipertensivos/administração & dosagem , Pressão Sanguínea/efeitos dos fármacos , Monitorização Ambulatorial da Pressão Arterial , Humanos , Hipertensão/diagnóstico , Hipertensão/tratamento farmacológico , Sistema Renina-Angiotensina/efeitos dos fármacos , Inibidores de Simportadores de Cloreto de Sódio/uso terapêuticoRESUMO
The way we view coronary artery disease in women has changed dramatically over the past decades. From an initial perspective that coronary artery disease was a male disorder and that women were protected by estrogens, there has been the gradual appreciation that this is an equal opportunity disease. Postmenopausal women are more likely than men to be hypertensive, dyslipidemic, and have multiple risk factors. Beyond the appreciation of estrogen's global effects on cardiovascular and metabolic function, our further advances in the understanding of sex-specific risks and management will be based on a greater understanding of the diversity of estrogen-mediated receptor pathways, including appreciation of the sometimes divergent effects of estrogen when acting either via the classic estrogen receptor or the more recently appreciated G protein-coupled estrogen receptor. In addition, the importance of sex-specific regulation of cardiometabolic processes beyond the sex hormones, specifically via SRY regulation, is only beginning to be understood. Finally, the author summarizes his recent studies demonstrating sex-specific G protein-coupled estrogen receptor regulation of blood pressure and cholesterol metabolism that may serve as a paradigm for the elucidation of sex-specific determinants of cardiovascular risk and the basis for sex-specific management of those risks.
Assuntos
Aterosclerose/genética , Doença da Artéria Coronariana/genética , Aterosclerose/fisiopatologia , Pressão Sanguínea/genética , Pressão Sanguínea/fisiologia , Colesterol/metabolismo , Doença da Artéria Coronariana/fisiopatologia , Estrogênios/fisiologia , Humanos , Receptores de Estrogênio/genética , Receptores de Estrogênio/fisiologia , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/fisiologia , Fatores de Risco , Cromossomos Sexuais/genética , Cromossomos Sexuais/fisiologia , Fatores SexuaisRESUMO
Hypertension Canada's 2020 guidelines for the prevention, diagnosis, risk assessment, and treatment of hypertension in adults and children provide comprehensive, evidence-based guidance for health care professionals and patients. Hypertension Canada develops the guidelines using rigourous methodology, carefully mitigating the risk of bias in our process. All draft recommendations undergo critical review by expert methodologists without conflict to ensure quality. Our guideline panel is diverse, including multiple health professional groups (nurses, pharmacy, academics, and physicians), and worked in concert with experts in primary care and implementation to ensure optimal usability. The 2020 guidelines include new guidance on the management of resistant hypertension and the management of hypertension in women planning pregnancy.
Assuntos
Hipertensão/diagnóstico , Hipertensão/terapia , Adulto , Algoritmos , Anti-Hipertensivos/uso terapêutico , Monitorização Ambulatorial da Pressão Arterial , Canadá , Doenças Cardiovasculares/complicações , Doenças Cardiovasculares/prevenção & controle , Criança , Complicações do Diabetes , Resistência a Medicamentos , Feminino , Promoção da Saúde , Insuficiência Cardíaca/complicações , Humanos , Hipertensão/complicações , Hipertensão/etiologia , Hipertrofia Ventricular Esquerda/complicações , Adesão à Medicação , Cuidado Pré-Concepcional , Gravidez , Complicações Cardiovasculares na Gravidez/terapia , Insuficiência Renal Crônica/complicações , Medição de Risco , Acidente Vascular Cerebral/complicações , TelemedicinaRESUMO
Recent studies suggest that the rapid and nongenomic effects of estradiol may be mediated through the G protein-coupled receptor dubbed GPR30 receptor. The present study examines the role of GPR30 versus a classical estrogen receptor (ERalpha) in mediating the growth regulatory effects of estradiol. GPR30 is readily detectable in freshly isolated vascular tissue but barely detectable in cultured vascular smooth muscle cells (VSMC). In freshly isolated aortic tissue, estradiol stimulated extracellular signal-regulated kinases (ERK) phosphorylation. In contrast, in cultured VSMC, where GPR30 expression is significantly reduced, estradiol inhibits ERK phosphorylation. Transfer of the genes encoding GPR30 led to estradiol stimulation of ERK phosphorylation, which is opposite the effects of estradiol in the primary culture of VSMCs. Transduction of the mineralocorticoid receptor (MR) had no effect on estradiol effects on ERK. Estradiol-mediated stimulation of ERK subsequent to heterologous GPR30 expression was pertussis toxin sensitive and phosphoinositide 3-kinase (PI3 kinase) dependent; under these conditions, estradiol also inhibited protein kinase A (PKA). In contrast, in the absence of GPR30 expression in cultured VSMC, estradiol stimulated PKA activity and inhibited ERK phosphorylation. To determine the functional effect of GPR30 (vs. estrogen receptor expression), we assessed estradiol-mediated apoptosis. In the absence of GPR30 expression, estradiol inhibited apoptosis. This effect was enhanced with ERalpha expression. In contrast, with GPR30 expression, estradiol stimulated apoptosis in an ERK-dependent manner. Thus the effect of estradiol on vascular smooth muscle cell apoptosis is likely dependent on the balance between ER-mediated PKA activation and GPR30-mediated PKA inhibition and PI3 kinase activation. Taken together, we postulate that modulation of GPR30 expression or activity may be an important determinant of the effects of estradiol in the vasculature.
Assuntos
Apoptose/fisiologia , Estradiol/metabolismo , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Músculo Liso Vascular/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Animais , Western Blotting , Células Cultivadas , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Ativação Enzimática/fisiologia , Miócitos de Músculo Liso/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Fosforilação , Ratos , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
BACKGROUND: Single-pill amlodipine/atorvastatin targets the two most common modifiable cardiovascular risk factors, hypertension and dyslipidaemia. We evaluated the clinical utility of this single pill to help patients across Europe and Canada achieve country-specific targets for blood pressure (BP) and low-density lipoprotein cholesterol (LDL-C). DESIGN: Two 16-week, open-label studies conducted in 122 study centres across the United Kingdom and Canada (JEWEL 1) and 113 centres across 11 European countries (JEWEL 2). METHODS: Patients with uncontrolled BP and controlled/uncontrolled LDL-C qualifying for treatment according to local governing guidelines were administered single-pill amlodipine/atorvastatin with appropriate lifestyle modification. Eight dosages of amlodipine/atorvastatin (5/10-10/80 mg) were titrated to achieve country-specific BP and LDL-C targets. The primary outcome was the percentage of patients reaching country-specific BP and LDL-C targets in 16 weeks. RESULTS: Among 2245 patients enrolled in the studies (JEWEL 1, n = 1138; JEWEL 2, n = 1107), 62.9% in JEWEL 1 and 50.6% in JEWEL 2 achieved both country-specific BP and LDL-C goals. BP was reduced by 20.4/10.7 and 21.8/12.6 mmHg in JEWEL 1 and JEWEL 2, respectively, and reductions in LDL-C were 0.90 mmol/l (34.8 mg/dl) and 1.09 mmol/l (42.2 mg/dl), respectively. The most common adverse events were peripheral oedema (11.0%), joint swelling (2.9%) and headache (2.9%), of which, only oedema was linked to study treatment. CONCLUSION: Single-pill amlodipine/atorvastatin is an effective and well-tolerated treatment, which in a real-world setting helped more than half of the patients achieve both BP and LDL-C targets as recommended by local guidelines. Although fewer patients met their goals in JEWEL 2 than JEWEL 1, reductions in BP and LDL-C were slightly greater in JEWEL 2, suggesting that the observed differences are likely because of more stringent targets in Europe than in the UK/Canada.