RESUMO
Many behaviors require the coordinated actions of somatic and autonomic functions. However, the underlying mechanisms remain elusive. By opto-stimulating different populations of descending spinal projecting neurons (SPNs) in anesthetized mice, we show that stimulation of excitatory SPNs in the rostral ventromedial medulla (rVMM) resulted in a simultaneous increase in somatomotor and sympathetic activities. Conversely, opto-stimulation of rVMM inhibitory SPNs decreased both activities. Anatomically, these SPNs innervate both sympathetic preganglionic neurons and motor-related regions in the spinal cord. Fiber-photometry recording indicated that the activities of rVMM SPNs correlate with different levels of muscle and sympathetic tone during distinct arousal states. Inhibiting rVMM excitatory SPNs reduced basal muscle and sympathetic tone, impairing locomotion initiation and high-speed performance. In contrast, silencing the inhibitory population abolished muscle atonia and sympathetic hypoactivity during rapid eye movement (REM) sleep. Together, these results identify rVMM SPNs as descending spinal projecting pathways controlling the tone of both the somatomotor and sympathetic systems.
Assuntos
Bulbo , Medula Espinal , Sistema Nervoso Simpático , Animais , Masculino , Camundongos , Locomoção/fisiologia , Bulbo/fisiologia , Camundongos Endogâmicos C57BL , Neurônios Motores/fisiologia , Neurônios/fisiologia , Sono REM/fisiologia , Medula Espinal/fisiologia , Sistema Nervoso Simpático/fisiologia , Comportamento Animal , Contagem de Células , Músculo EsqueléticoRESUMO
The surprising discovery that the diatomic gas nitric oxide (NO) is generated by mammalian cells and serves to regulate a multitude of physiological processes has continued to fascinate biologists for almost four decades. The biochemistry of NO is complex, and novel insights into the control of NO biosynthesis and mechanisms of signal transduction are continuously emerging. NO is a key regulator of cardiovascular function, metabolism, neurotransmission, immunity, and more, and aberrant NO signaling is a central feature of many major disorders including cardiovascular disease, diabetes, and cancer. Here, we discuss the basics of NO biology emphasizing recent advances in the field including novel means of increasing NO bioactivity with therapeutic and nutritional implications.
Assuntos
Doenças Cardiovasculares , Nitritos , Animais , Doenças Cardiovasculares/tratamento farmacológico , Fenômenos Fisiológicos Cardiovasculares , Humanos , Mamíferos/metabolismo , Óxido Nítrico/metabolismo , Nitritos/metabolismo , Nitritos/uso terapêutico , Transdução de SinaisRESUMO
The teleology of sex differences has been argued since at least as early as Aristotle's controversial Generation of Animals more than 300 years BC, which reflects the sex bias of the time to contemporary readers. Although the question "why are the sexes different" remains a topic of debate in the present day in metaphysics, the recent emphasis on sex comparison in research studies has led to the question "how are the sexes different" being addressed in health science through numerous observational studies in both health and disease susceptibility, including blood pressure regulation and hypertension. These efforts have resulted in better understanding of differences in males and females at the molecular level that partially explain their differences in vascular function and renal sodium handling and hence blood pressure and the consequential cardiovascular and kidney disease risks in hypertension. This review focuses on clinical studies comparing differences between men and women in blood pressure over the life span and response to dietary sodium and highlights experimental models investigating sexual dimorphism in the renin-angiotensin-aldosterone, vascular, sympathetic nervous, and immune systems, endothelin, the major renal sodium transporters/exchangers/channels, and the impact of sex hormones on these systems in blood pressure homeostasis. Understanding the mechanisms governing sex differences in blood pressure regulation could guide novel therapeutic approaches in a sex-specific manner to lower cardiovascular risks in hypertension and advance personalized medicine.
Assuntos
Hipertensão , Caracteres Sexuais , Animais , Feminino , Humanos , Masculino , Pressão Sanguínea/fisiologia , Rim , Hemodinâmica , SódioRESUMO
Intercalated cells (ICs) are found in the connecting tubule and the collecting duct. Of the three IC subtypes identified, type B intercalated cells are one of the best characterized and known to mediate Cl- absorption and HCO3- secretion, largely through the anion exchanger pendrin. This exchanger is thought to act in tandem with the Na+-dependent Cl-/HCO3- exchanger, NDCBE, to mediate net NaCl absorption. Pendrin is stimulated by angiotensin II and aldosterone administration via the angiotensin type 1a and the mineralocorticoid receptors, respectively. It is also stimulated in models of metabolic alkalosis, such as with NaHCO3 administration. In some rodent models, pendrin-mediated HCO3- secretion modulates acid-base balance. However, of probably more physiological or clinical significance is the role of these pendrin-positive ICs in blood pressure regulation, which occurs, at least in part, through pendrin-mediated renal Cl- absorption, as well as their effect on the epithelial Na+ channel, ENaC. Aldosterone stimulates ENaC directly through principal cell mineralocorticoid hormone receptor (ligand) binding and also indirectly through its effect on pendrin expression and function. In so doing, pendrin contributes to the aldosterone pressor response. Pendrin may also modulate blood pressure in part through its action in the adrenal medulla, where it modulates the release of catecholamines, or through an indirect effect on vascular contractile force. In addition to its role in Na+ and Cl- balance, pendrin affects the balance of other ions, such as K+ and I-. This review describes how aldosterone and angiotensin II-induced signaling regulate pendrin and the contribution of pendrin-positive ICs in the kidney to distal nephron function and blood pressure.
Assuntos
Rim/citologia , Rim/fisiologia , Transportadores de Sulfato/metabolismo , Equilíbrio Ácido-Base/efeitos dos fármacos , Equilíbrio Ácido-Base/fisiologia , Aldosterona/farmacologia , Angiotensina II/farmacologia , Animais , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica/fisiologia , HumanosRESUMO
Variability in quantitative traits has clinical, ecological, and evolutionary significance. Most genetic variants identified for complex quantitative traits have only a detectable effect on the mean of trait. We have developed the mean-variance test (MVtest) to simultaneously model the mean and log-variance of a quantitative trait as functions of genotypes and covariates by using estimating equations. The advantages of MVtest include the facts that it can detect effect modification, that multiple testing can follow conventional thresholds, that it is robust to non-normal outcomes, and that association statistics can be meta-analyzed. In simulations, we show control of type I error of MVtest over several alternatives. We identified 51 and 37 previously unreported associations for effects on blood-pressure variance and mean, respectively, in the UK Biobank. Transcriptome-wide association studies revealed 633 significant unique gene associations with blood-pressure mean variance. MVtest is broadly applicable to studies of complex quantitative traits and provides an important opportunity to detect novel loci.
Assuntos
Pressão Sanguínea , Estudo de Associação Genômica Ampla , Locos de Características Quantitativas , Humanos , Pressão Sanguínea/genética , Polimorfismo de Nucleotídeo Único , Modelos Genéticos , Genótipo , Variação Genética , Simulação por Computador , FenótipoRESUMO
Genome-wide association studies of blood pressure (BP) have identified >1,000 loci, but the effector genes and biological pathways at these loci are mostly unknown. Using published association summary statistics, we conducted annotation-informed fine-mapping incorporating tissue-specific chromatin segmentation and colocalization to identify causal variants and candidate effector genes for systolic BP, diastolic BP, and pulse pressure. We observed 532 distinct signals associated with ≥2 BP traits and 84 with all three. For >20% of signals, a single variant accounted for >75% posterior probability, 65 were missense variants in known (SLC39A8, ADRB2, and DBH) and previously unreported BP candidate genes (NRIP1 and MMP14). In disease-relevant tissues, we colocalized >80 and >400 distinct signals for each BP trait with cis-eQTLs and regulatory regions from promoter capture Hi-C, respectively. Integrating mouse, human disorder, gene expression and tissue abundance data, and literature review, we provide consolidated evidence for 436 BP candidate genes for future functional validation and discover several potential drug targets.
Assuntos
Estudo de Associação Genômica Ampla , Hipertensão , Humanos , Animais , Camundongos , Locos de Características Quantitativas/genética , Multiômica , Predisposição Genética para Doença , Hipertensão/genética , Polimorfismo de Nucleotídeo Único/genéticaRESUMO
Epidemiological studies have found that transportation noise increases the risk for cardiovascular morbidity and mortality, with solid evidence for ischemic heart disease, heart failure, and stroke. According to the World Health Organization, at least 1.6 million healthy life years are lost annually from traffic-related noise in Western Europe. Traffic noise at night causes fragmentation and shortening of sleep, elevation of stress hormone levels, and increased oxidative stress in the vasculature and the brain. These factors can promote vascular (endothelial) dysfunction, inflammation, and arterial hypertension, thus elevating cardiovascular risk. The present review focusses on the indirect, nonauditory cardiovascular health effects of noise. We provide an updated overview of epidemiological research on the effects of transportation noise on cardiovascular risk factors and disease, and mechanistic insights based on the latest clinical and experimental studies and propose new risk markers to address noise-induced cardiovascular effects in the general population. We will discuss the potential effects of noise on vascular dysfunction, oxidative stress, and inflammation in humans and animals. We will elaborately explain the underlying pathomechanisms by alterations of gene networks, epigenetic pathways, circadian rhythm, signal transduction along the neuronal-cardiovascular axis, and metabolism. We will describe current and future noise mitigation strategies. Finally, we will conduct an overall evaluation of the status of the current evidence of noise as a significant cardiovascular risk factor.
Assuntos
Doenças Cardiovasculares , Ruído dos Transportes , Estresse Oxidativo , Humanos , Ruído dos Transportes/efeitos adversos , Doenças Cardiovasculares/metabolismo , Doenças Cardiovasculares/etiologia , Doenças Cardiovasculares/epidemiologia , Animais , Fatores de Risco de Doenças Cardíacas , Exposição Ambiental/efeitos adversos , Fatores de RiscoRESUMO
BACKGROUND: The precise origin of newly formed ACTA2+ (alpha smooth muscle actin-positive) cells appearing in nonmuscularized vessels in the context of pulmonary hypertension is still debatable although it is believed that they predominantly derive from preexisting vascular smooth muscle cells (VSMCs). METHODS: Gli1Cre-ERT2; tdTomatoflox mice were used to lineage trace GLI1+ (glioma-associated oncogene homolog 1-positive) cells in the context of pulmonary hypertension using 2 independent models of vascular remodeling and reverse remodeling: hypoxia and cigarette smoke exposure. Hemodynamic measurements, right ventricular hypertrophy assessment, flow cytometry, and histological analysis of thick lung sections followed by state-of-the-art 3-dimensional reconstruction and quantification using Imaris software were used to investigate the contribution of GLI1+ cells to neomuscularization of the pulmonary vasculature. RESULTS: The data show that GLI1+ cells are abundant around distal, nonmuscularized vessels during steady state, and this lineage contributes to around 50% of newly formed ACTA2+ cells around these normally nonmuscularized vessels. During reverse remodeling, cells derived from the GLI1+ lineage are largely cleared in parallel to the reversal of muscularization. Partial ablation of GLI1+ cells greatly prevented vascular remodeling in response to hypoxia and attenuated the increase in right ventricular systolic pressure and right heart hypertrophy. Single-cell RNA sequencing on sorted lineage-labeled GLI1+ cells revealed an Acta2high fraction of cells with pathways in cancer and MAPK (mitogen-activated protein kinase) signaling as potential players in reprogramming these cells during vascular remodeling. Analysis of human lung-derived material suggests that GLI1 signaling is overactivated in both group 1 and group 3 pulmonary hypertension and can promote proliferation and myogenic differentiation. CONCLUSIONS: Our data highlight GLI1+ cells as an alternative cellular source of VSMCs in pulmonary hypertension and suggest that these cells and the associated signaling pathways represent an important therapeutic target for further studies.
Assuntos
Hipertensão Pulmonar , Remodelação Vascular , Proteína GLI1 em Dedos de Zinco , Animais , Proteína GLI1 em Dedos de Zinco/metabolismo , Proteína GLI1 em Dedos de Zinco/genética , Camundongos , Hipertensão Pulmonar/metabolismo , Hipertensão Pulmonar/fisiopatologia , Hipertensão Pulmonar/patologia , Músculo Liso Vascular/metabolismo , Músculo Liso Vascular/patologia , Miócitos de Músculo Liso/metabolismo , Miócitos de Músculo Liso/patologia , Camundongos Endogâmicos C57BL , Artéria Pulmonar/metabolismo , Artéria Pulmonar/patologia , Artéria Pulmonar/fisiopatologia , Camundongos Transgênicos , Masculino , Humanos , Hipóxia/metabolismo , Hipóxia/fisiopatologiaRESUMO
BACKGROUND: Nearly half of adults have hypertension, a major risk factor for cardiovascular disease. Mitochondrial hyperacetylation is linked to hypertension, but the role of acetylation of specific proteins is not clear. We hypothesized that acetylation of mitochondrial CypD (cyclophilin D) at K166 contributes to endothelial dysfunction and hypertension. METHODS: To test this hypothesis, we studied CypD acetylation in patients with essential hypertension, defined a pathogenic role of CypD acetylation in deacetylation mimetic CypD-K166R mutant mice and endothelial-specific GCN5L1 (general control of amino acid synthesis 5 like 1)-deficient mice using an Ang II (angiotensin II) model of hypertension. RESULTS: Arterioles from hypertensive patients had 280% higher CypD acetylation coupled with reduced Sirt3 (sirtuin 3) and increased GCN5L1 levels. GCN5L1 regulates mitochondrial protein acetylation and promotes CypD acetylation, which is counteracted by mitochondrial deacetylase Sirt3. In human aortic endothelial cells, GCN5L1 depletion prevents superoxide overproduction. Deacetylation mimetic CypD-K166R mice were protected from vascular oxidative stress, endothelial dysfunction, and Ang II-induced hypertension. Ang II-induced hypertension increased mitochondrial GCN5L1 and reduced Sirt3 levels resulting in a 250% increase in GCN5L1/Sirt3 ratio promoting CypD acetylation. Treatment with mitochondria-targeted scavenger of cytotoxic isolevuglandins (mito2HOBA) normalized GCN5L1/Sirt3 ratio, reduced CypD acetylation, and attenuated hypertension. The role of mitochondrial acetyltransferase GCN5L1 in the endothelial function was tested in endothelial-specific GCN5L1 knockout mice. Depletion of endothelial GCN5L1 prevented Ang II-induced mitochondrial oxidative stress, reduced the maladaptive switch of vascular metabolism to glycolysis, prevented inactivation of endothelial nitric oxide, preserved endothelial-dependent relaxation, and attenuated hypertension. CONCLUSIONS: These data support the pathogenic role of CypD acetylation in endothelial dysfunction and hypertension. We suggest that targeting cytotoxic mitochondrial isolevuglandins and GCN5L1 reduces CypD acetylation, which may be beneficial in cardiovascular disease.
Assuntos
Endotélio Vascular , Hipertensão , Mitocôndrias , Sirtuína 3 , Animais , Feminino , Humanos , Masculino , Camundongos , Acetilação , Angiotensina II , Células Cultivadas , Células Endoteliais/metabolismo , Células Endoteliais/enzimologia , Endotélio Vascular/metabolismo , Endotélio Vascular/fisiopatologia , Hipertensão/metabolismo , Hipertensão/fisiopatologia , Hipertensão/genética , Camundongos Endogâmicos C57BL , Camundongos Knockout , Mitocôndrias/metabolismo , Proteínas Mitocondriais/metabolismo , Proteínas Mitocondriais/genética , Proteínas do Tecido Nervoso , Estresse Oxidativo , Sirtuína 3/metabolismo , Sirtuína 3/genéticaRESUMO
Energetic demand and nutrient supply fluctuate as a function of time-of-day, in alignment with sleep-wake and fasting-feeding cycles. These daily rhythms are mirrored by 24-hour oscillations in numerous cardiovascular functional parameters, including blood pressure, heart rate, and myocardial contractility. It is, therefore, not surprising that metabolic processes also fluctuate over the course of the day, to ensure temporal needs for ATP, building blocks, and metabolism-based signaling molecules are met. What has become increasingly clear is that in addition to classic signal-response coupling (termed reactionary mechanisms), cardiovascular-relevant cells use autonomous circadian clocks to temporally orchestrate metabolic pathways in preparation for predicted stimuli/stresses (termed anticipatory mechanisms). Here, we review current knowledge regarding circadian regulation of metabolism, how metabolic rhythms are synchronized with cardiovascular function, and whether circadian misalignment/disruption of metabolic processes contribute toward the pathogenesis of cardiovascular disease.
Assuntos
Relógios Circadianos , Ritmo Circadiano , Coração , Relógios Circadianos/fisiologia , Sono/fisiologia , Miocárdio/metabolismoRESUMO
Hypertension is extremely common, affecting approximately 1 in every 2 adults globally. Chronic hypertension is the leading modifiable risk factor for cardiovascular disease and premature mortality worldwide. Despite considerable efforts to define mechanisms that underlie hypertension, a potentially major component of the disease, the role of circadian biology has been relatively overlooked in both preclinical models and humans. Although the presence of daily and circadian patterns has been observed from the level of the genome to the whole organism, the functional and structural impact of biological rhythms, including mechanisms such as circadian misalignment, remains relatively poorly defined. Here, we review the impact of daily rhythms and circadian systems in regulating blood pressure and the onset, progression, and consequences of hypertension. There is an emphasis on the impact of circadian biology in relation to vascular disease and end-organ effects that, individually or in combination, contribute to complex phenotypes such as cognitive decline and the loss of cardiac and brain health. Despite effective treatment options for some individuals, control of blood pressure remains inadequate in a substantial portion of the hypertensive population. Greater insight into circadian biology may form a foundation for novel and more widely effective molecular therapies or interventions to help in the prevention, treatment, and management of hypertension and its related pathophysiology.
Assuntos
Doenças Cardiovasculares , Hipertensão , Adulto , Humanos , Pressão Sanguínea/fisiologia , Ritmo Circadiano , CoraçãoRESUMO
BACKGROUND: Hypoxia and oxidative stress contribute to the development of pulmonary hypertension (PH). tRNA-derived fragments play important roles in RNA interference and cell proliferation, but their epitranscriptional roles in PH development have not been investigated. We aimed to gain insight into the mechanistic contribution of oxidative stress-induced 8-oxoguanine in pulmonary vascular remodeling. METHODS: Through small RNA modification array analysis and quantitative polymerase chain reaction, a significant upregulation of the 8-oxoguanine -modified tRF-1-AspGTC was found in the lung tissues and the serum of patients with PH. RESULTS: This modification occurs at the position 5 of the tRF-1-AspGTC (5o8G tRF). Inhibition of the 5o8G tRF reversed hypoxia-induced proliferation and apoptosis resistance in pulmonary artery smooth muscle cells. Further investigation unveiled that the 5o8G tRF retargeted mRNA of WNT5A (Wingless-type MMTV integration site family, member 5A) and CASP3 (Caspase3) and inhibited their expression. Ultimately, BMPR2 (Bone morphogenetic protein receptor 2) -reactive oxygen species/5o8G tRF/WNT5A signaling pathway exacerbated the progression of PH. CONCLUSIONS: Our study highlights the role of site-specific 8-oxoguanine-modified tRF in promoting the development of PH. Our findings present a promising therapeutic avenue for managing PH and propose 5o8G tRF as a potential innovative marker for diagnosing this disease.
Assuntos
Biomarcadores , Receptores de Proteínas Morfogenéticas Ósseas Tipo II , Hipertensão Pulmonar , Artéria Pulmonar , Hipertensão Pulmonar/metabolismo , Hipertensão Pulmonar/genética , Hipertensão Pulmonar/etiologia , Humanos , Receptores de Proteínas Morfogenéticas Ósseas Tipo II/metabolismo , Receptores de Proteínas Morfogenéticas Ósseas Tipo II/genética , Animais , Biomarcadores/metabolismo , Biomarcadores/sangue , Artéria Pulmonar/metabolismo , Proteína Wnt-5a/metabolismo , Proteína Wnt-5a/genética , Guanina/análogos & derivados , Guanina/metabolismo , Masculino , Estresse Oxidativo , Caspase 3/metabolismo , Miócitos de Músculo Liso/metabolismo , Proliferação de Células , Apoptose , Células Cultivadas , Remodelação Vascular , Feminino , Ratos , Espécies Reativas de Oxigênio/metabolismo , Músculo Liso Vascular/metabolismoRESUMO
The year 2024 marks the centennial of the initiation of the American Heart Association. Over the past 100 years, the American Heart Association has led groundbreaking discoveries in cardiovascular disease including salt sensitivity of blood pressure, which has been studied since the mid-1900s. Salt sensitivity of blood pressure is an important risk factor for cardiovascular events, but the phenotype remains unclear because of insufficient understanding of the underlying mechanisms and lack of feasible diagnostic tools. In honor of this centennial, we commemorate the initial discovery of salt sensitivity of blood pressure and chronicle the subsequent scientific discoveries and efforts to mitigate salt-induced cardiovascular disease with American Heart Association leading the way. We also highlight determinants of the pathophysiology of salt sensitivity of blood pressure in humans and recent developments in diagnostic methods and future prospects.
Assuntos
Pressão Sanguínea , Hipertensão , Cloreto de Sódio na Dieta , Animais , Humanos , American Heart Association/história , Pressão Sanguínea/efeitos dos fármacos , Doenças Cardiovasculares/fisiopatologia , Doenças Cardiovasculares/etiologia , Hipertensão/etiologia , Hipertensão/história , Hipertensão/fisiopatologia , Cloreto de Sódio na Dieta/efeitos adversos , Cloreto de Sódio na Dieta/história , Estados Unidos/epidemiologia , História do Século XX , História do Século XXIRESUMO
Circadian and diurnal variation in cerebral blood flow directly contributes to the diurnal variation in the risk of stroke, either through factors that trigger stroke or due to impaired compensatory mechanisms. Cerebral blood flow results from the integration of systemic hemodynamics, including heart rate, cardiac output, and blood pressure, with cerebrovascular regulatory mechanisms, including cerebrovascular reactivity, autoregulation, and neurovascular coupling. We review the evidence for the circadian and diurnal variation in each of these mechanisms and their integration, from the detailed evidence for mechanisms underlying the nocturnal nadir and morning surge in blood pressure to identifying limited available evidence for circadian and diurnal variation in cerebrovascular compensatory mechanisms. We, thus, identify key systemic hemodynamic factors related to the diurnal variation in the risk of stroke but particularly identify the need for further research focused on cerebrovascular regulatory mechanisms.
Assuntos
Acidente Vascular Cerebral , Humanos , Pressão Sanguínea/fisiologia , Hemodinâmica , Ritmo Circadiano , Circulação Cerebrovascular/fisiologiaRESUMO
BACKGROUND: GPCRs (G-protein-coupled receptors) play a central role in the regulation of smooth muscle cell (SMC) contractility, but the function of SMC-expressed orphan GPCR class C group 5 member C (GPRC5C) is unclear. The aim of this project is to define the role of GPRC5C in SMC in vitro and in vivo. METHODS: We studied the role of GPRC5C in the regulation of SMC contractility and differentiation in human and murine SMC in vitro, as well as in tamoxifen-inducible, SMC-specific GPRC5C knockout mice under basal conditions and in vascular disease in vivo. RESULTS: Mesenteric arteries from tamoxifen-inducible, SMC-specific GPRC5C knockout mice showed ex vivo significantly reduced angiotensin II (Ang II)-dependent calcium mobilization and contraction, whereas responses to other relaxant or contractile factors were normal. In vitro, the knockdown of GPRC5C in human aortic SMC resulted in diminished Ang II-dependent inositol phosphate production and lower myosin light chain phosphorylation. In line with this, tamoxifen-inducible, SMC-specific GPRC5C knockout mice showed reduced Ang II-induced arterial hypertension, and acute inactivation of GPRC5C was able to ameliorate established arterial hypertension. Mechanistically, we show that GPRC5C and the Ang II receptor AT1 dimerize, and knockdown of GPRC5C resulted in reduced binding of Ang II to AT1 receptors in HEK293 cells, human and murine SMC, and arteries from tamoxifen-inducible, SMC-specific GPRC5C knockout mice. CONCLUSIONS: Our data show that GPRC5C regulates Ang II-dependent vascular contraction by facilitating AT1 receptor-ligand binding and signaling.
Assuntos
Angiotensina II , Músculo Liso Vascular , Receptores Acoplados a Proteínas G , Animais , Humanos , Masculino , Camundongos , Angiotensina II/farmacologia , Células Cultivadas , Hipertensão/metabolismo , Hipertensão/fisiopatologia , Hipertensão/induzido quimicamente , Hipertensão/genética , Artérias Mesentéricas/metabolismo , Camundongos Endogâmicos C57BL , Camundongos Knockout , Contração Muscular , Músculo Liso Vascular/metabolismo , Miócitos de Músculo Liso/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Receptores Acoplados a Proteínas G/genética , VasoconstriçãoRESUMO
Cardiovascular homeostasis is maintained, in part, by neural signals arising from arterial baroreceptors that apprise the brain of blood volume and pressure. Here, we test whether neurons within the nodose ganglia that express angiotensin type-1a receptors (referred to as NGAT1aR) serve as baroreceptors that differentially influence blood pressure (BP) in male and female mice. Using Agtr1a-Cre mice and Cre-dependent AAVs to direct tdTomato to NGAT1aR, neuroanatomical studies revealed that NGAT1aR receive input from the aortic arch, project to the caudal nucleus of the solitary tract (NTS), and synthesize mechanosensitive ion channels, Piezo1/2 To evaluate the functionality of NGAT1aR, we directed the fluorescent calcium indicator (GCaMP6s) or the light-sensitive channelrhodopsin-2 (ChR2) to Agtr1a-containing neurons. Two-photon intravital imaging in Agtr1a-GCaMP6s mice revealed that NGAT1aR couple their firing to elevated BP, induced by phenylephrine (i.v.). Furthermore, optical excitation of NGAT1aR at their soma or axon terminals within the caudal NTS of Agtr1a-ChR2 mice elicited robust frequency-dependent decreases in BP and heart rate, indicating that NGAT1aR are sufficient to elicit appropriate compensatory responses to vascular mechanosensation. Optical excitation also elicited hypotensive and bradycardic responses in ChR2-expressing mice that were subjected to deoxycorticosterone acetate (DOCA)-salt hypertension; however, the duration of these effects was altered, suggestive of hypertension-induced impairment of the baroreflex. Similarly, increased GCaMP6s fluorescence observed after administration of phenylephrine was delayed in mice subjected to DOCA-salt or chronic delivery of angiotensin II. Collectively, these results reveal the structure and function of NGAT1aR and suggest that such neurons may be exploited to discern and relieve hypertension.
Assuntos
Acetato de Desoxicorticosterona , Hipertensão , Proteína Vermelha Fluorescente , Camundongos , Masculino , Feminino , Animais , Acetato de Desoxicorticosterona/farmacologia , Núcleo Solitário/fisiologia , Células Receptoras Sensoriais , Pressão Sanguínea/fisiologia , Fenilefrina/farmacologia , Canais IônicosRESUMO
Glucagon-like peptide-1 (GLP-1) and its analogs are widely used for diabetes treatment. The paraventricular nucleus (PVN) is crucial for regulating cardiovascular activity. This study aims to determine the roles of GLP-1 and its receptors (GLP-1R) in the PVN in regulating sympathetic outflow and blood pressure. Experiments were carried out in male normotensive rats and spontaneously hypertensive rats (SHR). Renal sympathetic nerve activity (RSNA) and mean arterial pressure (MAP) were recorded. GLP-1 and GLP-1R expressions were present in the PVN. PVN microinjection of GLP-1R agonist recombinant human GLP-1 (rhGLP-1) or EX-4 increased RSNA and MAP, which were prevented by GLP-1R antagonist exendin 9-39 (EX9-39) or GLP-1R antagonist 1, superoxide scavenger tempol, antioxidant N-acetylcysteine, NADPH oxidase (NOX) inhibitor apocynin, adenylyl cyclase (AC) inhibitor SQ22536 or protein kinase A (PKA) inhibitor H89. PVN microinjection of rhGLP-1 increased superoxide production, NADPH oxidase activity, cAMP level, AC, and PKA activity, which were prevented by SQ22536 or H89. GLP-1 and GLP-1R were upregulated in the PVN of SHR. PVN microinjection of GLP-1 agonist increased RSNA and MAP in both WKY and SHR, but GLP-1 antagonists caused greater effects in reducing RSNA and MAP in SHR than in WKY. The increased superoxide production and NADPH oxidase activity in the PVN of SHR were augmented by GLP-1R agonists but attenuated by GLP-1R antagonists. These results indicate that activation of GLP-1R in the PVN increased sympathetic outflow and blood pressure via cAMP-PKA-mediated NADPH oxidase activation and subsequent superoxide production. GLP-1 and GLP-1R upregulation in the PVN partially contributes to sympathetic overactivity and hypertension.
Assuntos
Peptídeo 1 Semelhante ao Glucagon , Receptor do Peptídeo Semelhante ao Glucagon 1 , Hipertensão , Núcleo Hipotalâmico Paraventricular , Ratos Endogâmicos SHR , Sistema Nervoso Simpático , Animais , Núcleo Hipotalâmico Paraventricular/efeitos dos fármacos , Núcleo Hipotalâmico Paraventricular/metabolismo , Masculino , Hipertensão/fisiopatologia , Hipertensão/metabolismo , Ratos , Sistema Nervoso Simpático/efeitos dos fármacos , Sistema Nervoso Simpático/fisiologia , Peptídeo 1 Semelhante ao Glucagon/metabolismo , Receptor do Peptídeo Semelhante ao Glucagon 1/metabolismo , Receptor do Peptídeo Semelhante ao Glucagon 1/antagonistas & inibidores , Pressão Sanguínea/efeitos dos fármacos , Pressão Sanguínea/fisiologia , Ratos Endogâmicos WKY , Ratos Sprague-DawleyRESUMO
BACKGROUND: The relationship between systolic blood pressure (SBP) and longevity is not fully understood. We aimed to determine which SBP levels in women ≥65 years of age with or without blood pressure medication were associated with the highest probability of surviving to 90 years of age. METHODS: The study population consisted of 16 570 participants enrolled in the Women's Health Initiative who were eligible to survive to 90 years of age by February 28, 2020, without a history of cardiovascular disease, diabetes, or cancer. Blood pressure was measured at baseline (1993 through 1998) and then annually through 2005. The outcome was defined as survival to 90 years of age with follow-up. Absolute probabilities of surviving to 90 years of age were estimated for all combinations of SBP and age using generalized additive logistic regression modeling. The SBP that maximized survival was estimated for each age, and a 95% CI was generated. RESULTS: During a median follow-up of 19.8 years, 9723 of 16 570 women (59%) survived to 90 years of age. Women with an SBP between 110 and 130 mm Hg at attained ages of 65, 70, 75, and 80 years had a 38% (95% CI, 34%-48%), 54% (52%-56%), 66% (64%-67%), or 75% (73%-78%) absolute probability to survive to 90 years of age, respectively. The probability of surviving to 90 years of age was lower for greater SBP levels. Women at the attained age of 80 years with 0%, 20%, 40%, 60%, 80%, or 100% time in therapeutic range (defined as an SBP between 110 and 130 mm Hg) had a 66% (64%-69%), 68% (67%-70%), 71% (69%-72%), 73% (71%-74%), 75% (72%-77%), or 77% (74%-79%) absolute survival probability to 90 years of age. CONCLUSIONS: For women >65 years of age with low cardiovascular disease and other chronic disease risk, an SBP level <130 mm Hg was found to be associated with longevity. These findings reinforce current guidelines targeting an SBP target <130 mm Hg in older women.
Assuntos
Pressão Sanguínea , Saúde da Mulher , Humanos , Feminino , Idoso , Idoso de 80 Anos ou mais , Longevidade , Seguimentos , Fatores Etários , Hipertensão/mortalidade , Hipertensão/fisiopatologia , Hipertensão/epidemiologia , Hipertensão/diagnóstico , Fatores de Risco , Sístole , Anti-Hipertensivos/uso terapêuticoRESUMO
BACKGROUND: The randomized, sham-controlled RADIANCE-HTN (A Study of the Recor Medical Paradise System in Clinical Hypertension) SOLO, RADIANCE-HTN TRIO, and RADIANCE II (A Study of the Recor Medical Paradise System in Stage II Hypertension) trials independently met their primary end point of a greater reduction in daytime ambulatory systolic blood pressure (SBP) 2 months after ultrasound renal denervation (uRDN) in patients with hypertension. To characterize the longer-term effectiveness and safety of uRDN versus sham at 6 months, after the blinded addition of antihypertensive treatments (AHTs), we pooled individual patient data across these 3 similarly designed trials. METHODS: Patients with mild to moderate hypertension who were not on AHT or with hypertension resistant to a standardized combination triple AHT were randomized to uRDN (n=293) versus sham (n=213); they were to remain off of added AHT throughout 2 months of follow-up unless specified blood pressure (BP) criteria were exceeded. In each trial, if monthly home BP was ≥135/85 mm Hg from 2 to 5 months, standardized AHT was sequentially added to target home BP <135/85 mm Hg under blinding to initial treatment assignment. Six-month outcomes included baseline- and AHT-adjusted change in daytime ambulatory, home, and office SBP; change in AHT; and safety. Linear mixed regression models using all BP measurements and change in AHT from baseline through 6 months were used. RESULTS: Patients (70% men) were 54.1±9.3 years of age with a baseline daytime ambulatory/home/office SBP of 150.5±9.8/151.0±12.4/155.5±14.4 mm Hg, respectively. From 2 to 6 months, BP decreased in both groups with AHT titration, but fewer uRDN patients were prescribed AHT (P=0.004), and fewer additional AHT were prescribed to uRDN patients versus sham patients (P=0.001). Whereas the unadjusted between-group difference in daytime ambulatory SBP was similar at 6 months, the baseline and medication-adjusted between-group difference at 6 months was -3.0 mm Hg (95% CI, -5.7, -0.2; P=0.033), in favor of uRDN+AHT. For home and office SBP, the adjusted between-group differences in favor of uRDN+AHT over 6 months were -5.4 mm Hg (-6.8, -4.0; P<0.001) and -5.2 mm Hg (-7.1, -3.3; P<0.001), respectively. There was no heterogeneity between trials. Safety outcomes were few and did not differ between groups. CONCLUSIONS: This individual patient-data analysis of 506 patients included in the RADIANCE trials demonstrates the maintenance of BP-lowering efficacy of uRDN versus sham at 6 months, with fewer added AHTs. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifiers: NCT02649426 and NCT03614260.
Assuntos
Hipertensão , Artéria Renal , Feminino , Humanos , Masculino , Anti-Hipertensivos/uso terapêutico , Pressão Sanguínea , Monitorização Ambulatorial da Pressão Arterial , Denervação/efeitos adversos , Denervação/métodos , Hipertensão/diagnóstico , Hipertensão/tratamento farmacológico , Rim , Artéria Renal/diagnóstico por imagem , Simpatectomia/métodos , Resultado do Tratamento , Pessoa de Meia-IdadeRESUMO
BACKGROUND: Disparities in hypertension control are well documented but underaddressed. METHODS: RICH LIFE (Reducing Inequities in Care of Hypertension: Lifestyle Improvement for Everyone) was a 2-arm, cluster randomized trial comparing the effect on blood pressure (BP) control (systolic BP ≤140 mm Hg, diastolic BP ≤90 mm Hg), patient activation, and disparities in BP control of 2 multilevel interventions, standard of care plus (SCP) and collaborative care/stepped care (CC/SC). SCP included BP measurement standardization, audit and feedback, and equity-leadership training. CC/SC added roles to address social or medical needs. Primary outcomes were BP control and patient activation at 12 months. Generalized estimating equations and mixed-effects regression models with fixed effects of time, intervention, and their interaction compared change in outcomes at 12 months from baseline. RESULTS: A total of 1820 adults with uncontrolled BP and ≥1 other risk factors enrolled in the study. Their mean age was 60.3 years, and baseline BP was 152.3/85.5 mm Hg; 59.4% were women; 57.4% were Black, 33.2% were White, and 9.4% were Hispanic; 74% had hyperlipidemia; and 45.1% had type 2 diabetes. CC/SC did not improve BP control rates more than SCP. Both groups achieved statistically and clinically significant BP control rates at 12 months (CC/SC: 57.3% [95% CI, 52.7%-62.0%]; SCP: 56.7% [95% CI, 51.9%-61.5%]). Pairwise comparisons between racial and ethnic groups showed overall no significant differences in BP control at 12 months. Patients with coronary heart disease showed greater achievement of BP control in CC/SC than in SCP (64.0% [95% CI, 54.1%-73.9%] versus 50.8% [95% CI, 42.6%-59.0%]; P=0.04), as did patients in rural areas (67.3% [95% CI, 49.8%-84.8%] versus 47.8% [95% CI, 32.4%-63.2%]; P=0.01). Individuals in both arms experienced statistically and clinically significant reductions in mean systolic BP (CC/SC: -13.8 mm Hg [95% CI, -15.2 to -12.5]; SCP: -14.6 mm Hg [95% CI, -15.9 to -13.2]) and diastolic BP (CC/SC: -6.9 mm Hg [95% CI, -7.8 to -6.1]; SCP: -5.5 mm Hg [95% CI, -6.4 to -4.6]) over time. The difference in diastolic BP reduction between CC/SC and SCP over time was statistically significant (-1.4 mm Hg [95% CI, -2.6 to -0.2). Patient activation did not differ between arms. CC/SC showed greater improvements in patient ratings of chronic illness care (Patient Assessment of Chronic Illness Care score) over 12 months (0.12 [95% CI, 0.02-0.22]). CONCLUSIONS: Adding a collaborative care team to enhanced standard of care did not improve BP control but did improve patient ratings of chronic illness care.