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BACKGROUND: Salt sensitivity of blood pressure is an independent predictor of cardiovascular morbidity and mortality. The exact mechanism by which salt intake increases blood pressure and cardiovascular risk is unknown. We previously found that sodium entry into antigen-presenting cells (APCs) via the amiloride-sensitive epithelial sodium channel EnaC (epithelial sodium channel) leads to the formation of IsoLGs (isolevuglandins) and release of proinflammatory cytokines to activate T cells and modulate salt-sensitive hypertension. In the current study, we hypothesized that ENaC-dependent entry of sodium into APCs activates the NLRP3 (NOD [nucleotide-binding and oligomerization domain]-like receptor family pyrin domain containing 3) inflammasome via IsoLG formation leading to salt-sensitive hypertension. METHODS: We performed RNA sequencing on human monocytes treated with elevated sodium in vitro and Cellular Indexing of Transcriptomes and Epitopes by Sequencing analysis of peripheral blood mononuclear cells from participants rigorously phenotyped for salt sensitivity of blood pressure using an established inpatient protocol. To determine mechanisms, we analyzed inflammasome activation in mouse models of deoxycorticosterone acetate salt-induced hypertension as well as salt-sensitive mice with ENaC inhibition or expression, IsoLG scavenging, and adoptive transfer of wild-type dendritic cells into NLRP3 deficient mice. RESULTS: We found that high levels of salt exposure upregulates the NLRP3 inflammasome, pyroptotic and apoptotic caspases, and IL (interleukin)-1ß transcription in human monocytes. Cellular Indexing of Transcriptomes and Epitopes by Sequencing revealed that components of the NLRP3 inflammasome and activation marker IL-1ß dynamically vary with changes in salt loading/depletion. Mechanistically, we found that sodium-induced activation of the NLRP3 inflammasome is ENaC and IsoLG dependent. NLRP3 deficient mice develop a blunted hypertensive response to elevated sodium, and this is restored by the adoptive transfer of NLRP3 replete APCs. CONCLUSIONS: These findings reveal a mechanistic link between ENaC, inflammation, and salt-sensitive hypertension involving NLRP3 inflammasome activation in APCs. APC activation via the NLRP3 inflammasome can serve as a potential diagnostic biomarker for salt sensitivity of blood pressure.
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Hipertensión , Inflamasomas , Animales , Canales Epiteliales de Sodio/genética , Epítopos , Humanos , Hipertensión/inducido químicamente , Hipertensión/genética , Inflamasomas/metabolismo , Interleucina-1beta/metabolismo , Leucocitos Mononucleares/metabolismo , Ratones , Ratones Endogámicos C57BL , Proteína con Dominio Pirina 3 de la Familia NLR/genética , Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo , Sodio/metabolismo , Cloruro de Sodio/metabolismo , Cloruro de Sodio Dietético/efectos adversosRESUMEN
BACKGROUND AND AIMS: High sodium intake is associated with obesity and insulin resistance, and high extracellular sodium content may induce systemic inflammation, leading to cardiovascular disease. In this study, we aim to investigate whether high tissue sodium accumulation relates with obesity-related insulin resistance and whether the pro-inflammatory effects of excess tissue sodium accumulation may contribute to such association. METHODS AND RESULTS: In a cross-sectional study of 30 obese and 53 non-obese subjects, we measured insulin sensitivity determined as glucose disposal rate (GDR) using hyperinsulinemic euglycemic clamp, and tissue sodium content using 23Na magnetic resonance imaging. Median age was 48 years, 68% were female and 41% were African American. Median (interquartile range) BMI was 33 (31.5, 36.3) and 25 (23.5, 27.2) kg/m2 in the obese and non-obese individuals, respectively. In obese individuals, insulin sensitivity negatively correlated with muscle (r = -0.45, p = 0.01) and skin sodium (r = -0.46, p = 0.01). In interaction analysis among obese individuals, tissue sodium had a greater effect on insulin sensitivity at higher levels of high-sensitivity C-reactive protein (p-interaction = 0.03 and 0.01 for muscle and skin Na+, respectively) and interleukin-6 (p-interaction = 0.024 and 0.003 for muscle and skin Na+, respectively). In interaction analysis of the entire cohort, the association between muscle sodium and insulin sensitivity was stronger with increasing levels of serum leptin (p-interaction = 0.01). CONCLUSIONS: Higher muscle and skin sodium are associated with insulin resistance in obese patients. Whether high tissue sodium accumulation has a mechanistic role in the development of obesity-related insulin resistance through systemic inflammation and leptin dysregulation remains to be examined in future studies. CLINICALTRIALS: gov registration: NCT02236520.
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Resistencia a la Insulina , Humanos , Femenino , Persona de Mediana Edad , Masculino , Leptina , Glucemia/metabolismo , Insulina , Estudios Transversales , Obesidad , Inflamación/diagnóstico , SodioRESUMEN
Salt-sensitivity of blood pressure (SSBP) affects 50% of the hypertensive and 25% of the normotensive populations. Importantly, SSBP is associated with increased risk for mortality in both populations independent of blood pressure. Despite its deleterious effects, the pathogenesis of SSBP is not fully understood. Emerging evidence suggests a novel role of bile acids in salt-sensitive hypertension and that they may play a crucial role in regulating inflammation and fluid volume homeostasis. Mechanistic evidence implicates alterations in the gut microbiome, the epithelial sodium channel (ENaC), the farnesoid X receptor, and the G protein-coupled bile acid receptor TGR5 in bile acid-mediated effects on cardiovascular function. The mechanistic interplay between excess dietary sodium-induced alterations in the gut microbiome and immune cell activation, bile acid signaling, and whether such interplay may contribute to the etiology of SSBP is still yet to be defined. The main goal of this review is to discuss the potential role of bile acids in the pathogenesis of cardiovascular disease with a focus on salt-sensitive hypertension.
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Microbioma Gastrointestinal , Hipertensión , Ácidos y Sales Biliares , Microbioma Gastrointestinal/fisiología , Humanos , Hipertensión/inducido químicamente , Hígado , Cloruro de Sodio Dietético/efectos adversosRESUMEN
PURPOSE OF REVIEW: The study aims to review recent advances in knowledge on the interplay between miRNAs and the sex-determining Region Y (SRY)-related high-mobility-group box 6 (Sox6) in physiology and pathophysiology, highlighting an important role in autoimmune and cardiometabolic conditions. RECENT FINDINGS: The transcription factor Sox6 is an important member of the SoxD family and plays an indispensable role in adult tissue homeostasis, regeneration, and physiology. Abnormal expression of the Sox6 gene has been implicated in several disease conditions including diabetes, cardiomyopathy, autoimmune diseases, and hypertension. Expression of Sox6 is regulated by miRNAs, which are RNAs of about 22 nucleotides, and have also been implicated in several pathophysiological conditions where Sox6 plays a role. Regulation of Sox6 by miRNAs is important in diverse physiological tissues and organs. Dysregulation of the interplay between miRNAs and Sox6 is an important determinant of various disease conditions and may be actionable for therapeutic purposes.
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Hipertensión , MicroARNs , Humanos , MicroARNs/genética , MicroARNs/metabolismo , Factores de Transcripción SOXD/genética , Factores de Transcripción SOXD/metabolismoRESUMEN
Post-transplant diabetes mellitus (PTDM) is a common complication of solid organ transplantation and a major cause of increased morbidity and mortality. Additionally, solid organ transplant patients may have pre-existent type 2 diabetes mellitus (T2DM). While insulin is the treatment of choice for hyperglycemia in the first weeks after transplantation, there is no preferred first line agent for long-term management of PTDM or pre-existent T2DM. Glucagon-like peptide-1 receptor agonists (GLP-1RA) and sodium-glucose cotransporter 2 (SGLT2) inhibitors improve glycemic control, lower body weight, and blood pressure, are recommended after lifestyle and metformin as initial therapy for diabetic patients with cardiovascular or kidney comorbidities regarding their cardiorenal benefits. Furthermore, the mechanisms of action of GLP-1RA may counteract some of the driving forces for PTDM, as calcineurin-induced ß cell toxicity as per preclinical data, and improve obesity. However, their use in the treatment of PTDM is currently limited by a paucity of data. Retrospective observational and small exploratory studies suggest that GLP-1RA effectively improve glycemic control and induce weight loss in patients with PTDM without interacting with commonly used immunosuppressive agents, although randomized-controlled clinical trials are required to confirm their safety and efficacy. In this narrative review, we evaluate the risk factors and pathogenesis of PTDM and compare the potential roles of GLP-1RA and SGLT2 inhibitors in PTDM prevention and management as well as in pre-existent T2DM, and providing a roadmap for evidence generation on newer antidiabetic drugs for solid organ transplantation.
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Diabetes Mellitus Tipo 2 , Trasplante de Órganos , Diabetes Mellitus Tipo 2/complicaciones , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Receptor del Péptido 1 Similar al Glucagón , Glucosa , Humanos , Hipoglucemiantes/uso terapéutico , Estudios Retrospectivos , SodioRESUMEN
BACKGROUND: To investigate if remote ischemic preconditioning (RIPC) can offer any renoprotective value by counteracting the deleterious effect of partial nephrectomy (PN) under warm ischemia on renal function. METHODS: Four groups, each with 5 Wistar albino rats, were constructed; RIPC + PN, PN, RIPC and sham. Right nephrectomy was performed to constitute a solitary kidney model. RIPC denoted sequential clamping/declamping of the femoral artery/vein complex. PN was performed under warm-ischemia following RIPC. Blood samples were collected on multiple occasions until euthanasia on day 7. Immunoassays were conducted to measure the serum and tissues levels of kidney injury markers. Kidneys were examined histologically and morphometric analyzes were performed using digital scanning. RESULTS: IL-33 levels did not differ significantly between the groups. Serum levels of KIM-1, NGAL, and aldose reductase in RIPC + PN, PN and RIPC groups were significantly lower than that of sham group. Tissue biomarker levels were similar across groups. The observed trend in mean necrosis area of PN group was higher than that of RIPC + PN group (p > 0.05). The transitional zone between necrosis and healthy tissue showed a trend towards increasing width in the rats subjected to RIPC before PN vs. those who underwent PN without RIPC (p > 0.05). CONCLUSION: RIPC failed to counteract the renal functional consequences of PN under warm ischemia in a solitary kidney animal model. The supportive but marginal histological findings in favor of RIPC's renoprotective potential were not supplemented with the changes in serum and tissue biomarker levels.
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Moléculas de Adhesión Celular/análisis , Precondicionamiento Isquémico/métodos , Riñón , Lipocalina 2/análisis , Nefrectomía , Daño por Reperfusión , Aldehído Reductasa/análisis , Animales , Biomarcadores/análisis , Modelos Animales de Enfermedad , Riñón/metabolismo , Riñón/patología , Riñón/fisiopatología , Pruebas de Función Renal , Nefrectomía/efectos adversos , Nefrectomía/métodos , Ratas , Ratas Wistar , Daño por Reperfusión/sangre , Daño por Reperfusión/etiología , Daño por Reperfusión/patología , Resultado del Tratamiento , Isquemia Tibia/métodosRESUMEN
WHAT IS KNOWN AND OBJECTIVE: Erlotinib is a small molecule tyrosine kinase inhibitor which blocks the activation of epidermal growth factor receptor (EGFR), a transmembrane receptor that is upregulated in many cancer types. Inhibition of angiogenesis with consequent impairments in intratumoral microcirculation is one of the mechanisms through which EGFR inhibition halts the progression of cancer. A consequence of impaired microcirculation is intratumoral hypoxia, which results in increases in serum uric acid levels. The goal of this study was to investigate the relationship between serum uric acid levels and response to erlotinib in metastatic non-small-cell lung cancer (NSCLC). METHODS: A total of 56 patients with metastatic non-small-cell lung cancer who received erlotinib for a duration of at least 3 months were included in this retrospective cohort study. Demographic characteristics, progression status, baseline serum uric levels and 3-month serum uric acid levels were recorded and analysed. RESULTS AND DISCUSSION: Of the study population, 21 (37.5%) were female and 35 (62.5%) were male patients. No significant difference in above demographic characteristics was observed among exitus, survivor with progression and survivor without progression groups. Patients who responded favourably to erlotinib with no progression of their disease had significantly increased uric acid levels at 3-month follow-up (P = .01). Such a correlation was not observed if the patient was exitus (P = .47) or had progressed on erlotinib therapy (P = .19). WHAT IS NEW AND CONCLUSION: In conclusion, this study is the first to demonstrate significant increases in serum uric acid levels in patients with metastatic NSCLC who responded favourably to erlotinib and had no progression under erlotinib therapy. Further studies are required to confirm and characterize serum uric acid as a novel biomarker in predicting the outcome in those with metastatic NSCLC.
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Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Clorhidrato de Erlotinib/administración & dosificación , Neoplasias Pulmonares/tratamiento farmacológico , Inhibidores de Proteínas Quinasas/administración & dosificación , Ácido Úrico/sangre , Anciano , Biomarcadores de Tumor/sangre , Carcinoma de Pulmón de Células no Pequeñas/patología , Estudios de Cohortes , Progresión de la Enfermedad , Receptores ErbB/antagonistas & inhibidores , Femenino , Estudios de Seguimiento , Humanos , Neoplasias Pulmonares/patología , Masculino , Persona de Mediana Edad , Metástasis de la Neoplasia , Estudios Retrospectivos , Resultado del TratamientoRESUMEN
The Coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) started in December 2019 and has affected millions of lives worldwide, while many aspects of the illness are still unknown. Current data show that many hospitalized COVID-19 patients suffer from kidney damage, in the form of proteinuria, hematuria or acute kidney injury (AKI). AKI is especially prevalent among severe and critically ill COVID-19 patients and is a predictor of mortality. The pathophysiology of AKI in COVID-19 is unclear. Early reports of histopathologic examination from autopsied kidney tissue show SARS-CoV-2 viral particles in renal tubular cells and podocytes, suggesting direct viral infection, as well as findings of acute tubular necrosis, while rhabdomyolysis-associated AKI and glomerulopathies may also occur. As of today, only remdesivir has been authorized to treat COVID-19. Ongoing research investigates potential of anti-viral and anti-inflammatory agents along with safety and efficacy of commonly prescribed drugs such as renin-angiotensin-aldosterone system blockers. This review discusses the prevalence of AKI and its association with outcome, while highlighting possible mechanisms of AKI and suggesting organ protective measures to prevent the development of kidney damage.
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Lesión Renal Aguda/epidemiología , COVID-19/epidemiología , SARS-CoV-2 , Lesión Renal Aguda/complicaciones , COVID-19/complicaciones , Salud Global , Humanos , PrevalenciaRESUMEN
Renal hyperfiltration, defined as an increased glomerular filtration rate above normal values, is associated with early phases of kidney disease in the setting of various conditions such as obesity and diabetes. Although it is recognized that glomerular hyperfiltration, that is, increased filtration per nephron unit (usually studied at low glomerular filtration levels and often referred to as single nephron hyperfiltration), is a risk factor for the progression of chronic kidney disease, the implications of having renal hyperfiltration for cardiovascular disease and mortality risk are incompletely understood. Recent evidence from diverse populations, including healthy individuals and patients with diabetes or established cardiovascular disease, suggests that renal hyperfiltration is associated with a higher risk of cardiovascular disease and all-cause mortality. In this review, we critically summarize the existing studies, discuss possible mechanisms, and describe the remaining gaps in our knowledge regarding the association of renal hyperfiltration with cardiovascular disease and mortality risk.
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Enfermedades Cardiovasculares , Tasa de Filtración Glomerular/fisiología , Insuficiencia Renal Crónica , Adulto , Anciano , Anciano de 80 o más Años , Enfermedades Cardiovasculares/complicaciones , Enfermedades Cardiovasculares/epidemiología , Enfermedades Cardiovasculares/mortalidad , Complicaciones de la Diabetes/epidemiología , Complicaciones de la Diabetes/mortalidad , Complicaciones de la Diabetes/fisiopatología , Femenino , Humanos , Glomérulos Renales/fisiopatología , Masculino , Persona de Mediana Edad , Insuficiencia Renal Crónica/complicaciones , Insuficiencia Renal Crónica/epidemiología , Insuficiencia Renal Crónica/mortalidad , Insuficiencia Renal Crónica/fisiopatología , Factores de Riesgo , Adulto JovenRESUMEN
We report the first synthesis of silicon nanocrystals embedded in a silicon nitride matrix through a direct pyrolysis of a preceramic polymer (perhydropolysilazane). Structural analysis carried out by XRD, XPS, Raman and TEM reveals the formation of silicon quantum dots and correlates the microstructures with the annealing temperature. The photoluminescence of the nanocomposites was investigated by both linear and nonlinear measurements. Furthermore we demonstrate an enhanced chemical resistance of the nitride matrix, compared to the typical oxide one, in both strongly acidic and basic environments. The proposed synthesis via polymer pyrolysis is a striking innovation potentially allowing a mass-scale production nitride embedded Si nanocrystals.
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BACKGROUND: Chronic inflammation and insulin resistance are highly prevalent in patients on maintenance haemodialysis (MHD) and are strongly associated with protein energy wasting. We conducted a pilot, randomized, placebo-controlled trial of recombinant human interleukin-1 receptor antagonist (IL-1ra) and pioglitazone to explore the safety, feasibility and efficacy for insulin-mediated protein metabolism in patients undergoing MHD. METHODS: Twenty-four patients were randomized to receive IL-1ra, pioglitazone or placebo for 12 weeks. Changes in serum inflammatory markers and insulin-mediated protein synthesis, breakdown and net balance in the whole-body and skeletal muscle compartments were assessed using hyperinsulinaemic-hyperaminoacidemic clamp technique at baseline and Week 12. RESULTS: Among 24 patients, median (interquartile range) age was 51 (40, 61), 79% were African American and 21% had diabetes mellitus. All patients initiated on intervention completed the study, and no serious adverse events were observed. There was a statistically significant decrease in serum high-sensitivity C-reactive protein in the pioglitazone group compared with placebo, but not in the IL-1ra group. No significant differences in the changes of whole-body or skeletal muscle protein synthesis, breakdown and net balance were found between the groups. CONCLUSIONS: In this pilot study, there were no statistically significant effects of 12 weeks of IL-1ra or pioglitazone on protein metabolism in patients on MHD. CLINICALTRIALS: gov registration: NCT02278562.
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Proteína Antagonista del Receptor de Interleucina 1 , Diálisis Renal , Humanos , Pioglitazona/uso terapéutico , Proteína Antagonista del Receptor de Interleucina 1/uso terapéutico , Proyectos Piloto , Insulina , BiomarcadoresRESUMEN
BACKGROUND: The mechanisms by which salt increases blood pressure in people with salt sensitivity remain unclear. Our previous studies found that high sodium enters antigen-presenting cells (APCs) via the epithelial sodium channel and leads to the production of isolevuglandins and hypertension. In the current mechanistic clinical study, we hypothesized that epithelial sodium channel-dependent isolevuglandin-adduct formation in APCs is regulated by epoxyeicosatrienoic acids (EETs) and leads to salt-sensitive hypertension in humans. METHODS: Salt sensitivity was assessed in 19 hypertensive subjects using an inpatient salt loading and depletion protocol. Isolevuglandin-adduct accumulation in APCs was analyzed using flow cytometry. Gene expression in APCs was analyzed using cellular indexing of transcriptomes and epitopes by sequencing analysis of blood mononuclear cells. Plasma and urine EETs were measured using liquid chromatography-mass spectrometry. RESULTS: Baseline isolevuglandin+ APCs correlated with higher salt-sensitivity index. Isolevuglandin+ APCs significantly decreased from salt loading to depletion with an increasing salt-sensitivity index. We observed that human APCs express the epithelial sodium channel δ subunit, SGK1 (salt-sensing kinase serum/glucocorticoid kinase 1), and cytochrome P450 2S1. We found a direct correlation between baseline urinary 14,15 EET and salt-sensitivity index, whereas changes in urinary 14,15 EET negatively correlated with isolevuglandin+ monocytes from salt loading to depletion. Coincubation with 14,15 EET inhibited high-salt-induced increase in isolevuglandin+ APC. CONCLUSIONS: Isolevuglandin formation in APCs responds to acute changes in salt intake in salt-sensitive but not salt-resistant people with hypertension, and this may be regulated by renal 14,15 EET. Baseline levels of isolevuglandin+ APCs or urinary 14,15 EET may provide diagnostic tools for salt sensitivity without a protocol of salt loading.
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Hipertensión , Lípidos , Cloruro de Sodio Dietético , Humanos , Cloruro de Sodio Dietético/metabolismo , Canales Epiteliales de Sodio/metabolismo , Cloruro de Sodio/metabolismo , Eicosanoides , Presión Sanguínea/fisiologíaRESUMEN
BACKGROUND AND AIMS: High tissue sodium accumulation and intermuscular adipose tissue (IMAT) are associated with aging, type 2 diabetes, and chronic kidney disease. In this study, we aim to investigate whether high lower-extremity tissue sodium accumulation relates to IMAT quantity and whether systemic inflammatory mediators and adipocytokines contribute to such association. METHODS: Tissue sodium content and IMAT accumulation (percentage of IMAT area to muscle area) were measured in 83 healthy individuals using sodium imaging (23Na-MRI) and proton (1H-MRI) imaging of the calf. Insulin sensitivity was assessed by glucose disposal rate (GDR) measured with the hyperinsulinemic-euglycemic clamp. RESULTS: Median (interquartile range) muscle and skin sodium contents were 16.6 (14.9, 19.0) and 12.6 (10.9, 16.7) mmol/L, respectively. Median IMAT was 3.69 (2.80, 5.37) %. In models adjusted for age, sex, BMI, GDR, adiponectin, and high-sensitivity C-reactive protein, increasing tissue sodium content was significantly associated with higher IMAT quantity (p = 0.018 and 0.032 for muscle and skin tissue sodium, respectively). In subgroup analysis stratified by sex, skin sodium was significantly associated with IMAT only among men. In interaction analysis, the association between skin sodium and IMAT was greater with increasing levels of high-sensitivity C-reactive protein and interleukin-6 (p for interaction = 0.022 and 0.006, respectively). CONCLUSIONS: Leg muscle and skin sodium are associated with IMAT quantity among healthy individuals. The relationship between skin sodium and IMAT may be mediated by systemic inflammation.
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Tejido Adiposo , Músculo Esquelético , Sodio , Humanos , Masculino , Femenino , Tejido Adiposo/metabolismo , Tejido Adiposo/diagnóstico por imagen , Adulto , Sodio/metabolismo , Músculo Esquelético/metabolismo , Persona de Mediana Edad , Piel/metabolismo , Resistencia a la Insulina , Imagen por Resonancia Magnética/métodosRESUMEN
BACKGROUND: Salt sensitivity of blood pressure (SSBP) is an independent risk factor for cardiovascular morbidity and mortality, yet the etiology is poorly understood. We previously found that serum/glucocorticoid-regulated kinase 1 (SGK1) and epoxyeicosatrienoic acids (EETs) regulate epithelial sodium channel (ENaC)-dependent sodium entry into monocyte-derived antigen-presenting cells (APCs) and activation of NADPH oxidase, leading to the formation of isolevuglandins (IsoLGs) in SSBP. Whereas aldosterone via the mineralocorticoid receptor (MR) activates SGK1 leading to hypertension, our past findings indicate that levels of plasma aldosterone do not correlate with SSBP, and there is little to no MR expression in APCs. Thus, we hypothesized that cortisol acting via the glucocorticoid receptor (GR), not the MR in APCs mediates SGK1 actions to induce SSBP. METHODS: We performed cellular indexing of transcriptomes and epitopes by sequencing (CITE-Seq) analysis on peripheral blood mononuclear cells of humans rigorously phenotyped for SSBP using an inpatient salt loading/depletion protocol to determine expression of MR, GR, and SGK1 in immune cells. In additional experiments, we performed bulk transcriptomic analysis on isolated human monocytes following in vitro treatment with high salt from a separate cohort. We then measured urine and plasma cortisol, cortisone, renin, and aldosterone. Subsequently, we measured the association of these hormones with changes in systolic, diastolic, mean arterial pressure and pulse pressure as well as immune cell activation via IsoLG formation. RESULTS: We found that myeloid APCs predominantly express the GR and SGK1 with no expression of the MR. Expression of the GR in APCs increased after salt loading and decreased with salt depletion in salt-sensitive but not salt-resistant people and was associated with increased expression of SGK1. Moreover, we found that plasma and urine cortisol/cortisone but not aldosterone/renin correlated with SSBP and APCs activation via IsoLGs. We also found that cortisol negatively correlates with EETs. CONCLUSION: Our findings suggest that renal cortisol signaling via the GR but not the MR in APCs contributes to SSBP via cortisol. Urine and plasma cortisol may provide an important currently unavailable feasible diagnostic tool for SSBP. Moreover, cortisol-GR-SGK1-ENaC signaling pathway may provide treatment options for SSBP.
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A major regulator of blood pressure and volume homeostasis in the kidney is the epithelial sodium channel (ENaC). ENaC is composed of alpha(α)/beta(ß)/gamma(γ) or delta(δ)/beta(ß)/gamma(γ) subunits. The δ subunit is functional in the guinea pig, but not in routinely used experimental rodent models including rat or mouse, and thus remains the least understood of the four subunits. While the δ subunit is poorly expressed in the human kidney, we recently found that its gene variants are associated with blood pressure and kidney function. The δ subunit is expressed in the human vasculature where it may influence vascular function. Moreover, we recently found that the δ subunit is also expressed human antigen presenting cells (APCs). Our studies indicate that extracellular Na+ enters APCs via ENaC leading to inflammation and salt-induced hypertension. In this review, we highlight recent findings on the role of extra-renal ENaC in inflammation, vascular dysfunction, and blood pressure modulation. Targeting extra-renal ENaC may provide new drug therapies for salt-induced hypertension.
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Introduction: Salt sensitivity of blood pressure is a phenomenon in which blood pressure changes according to dietary sodium intake. Our previous studies found that high salt activates antigen presenting cells, resulting in the development of hypertension. The mechanisms by which salt-induced immune cell activation is regulated in salt sensitivity of blood pressure are unknown. In the current study, we investigated dietary salt-induced effects on the renin-angiotensin-aldosterone system (RAAS) gene expression in myeloid immune cells and their impact on salt sensitive hypertension in humans. Methods: We performed both bulk and single-cell sequencing analysis on immune cells with in vitro and in vivo high dietary salt treatment in humans using a rigorous salt-loading/depletion protocol to phenotype salt-sensitivity of blood pressure. We also measured plasma renin and aldosterone using radioimmunoassay. Results: We found that while in vitro high sodium exposure downregulated the expression of renin, renin binding protein and renin receptor, there were no significant changes in the genes of the renin-angiotensin system in response to dietary salt loading and depletion in vivo. Plasma renin in salt sensitive individuals tended to be lower with a blunted response to the salt loading/depletion challenge as previously reported. Discussion: These findings suggest that unlike systemic RAAS, acute changes in dietary salt intake do not regulate RAAS expression in myeloid immune cells.
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Salt-sensitive hypertension is a major risk factor for cardiovascular morbidity and mortality. The pathophysiologic mechanisms leading to different individual BP responses to changes in dietary salt remain elusive. Research in the last two decades revealed that the immune system plays a critical role in the development of hypertension and related end organ damage. Moreover, sodium accumulates nonosmotically in human tissue, including the skin and muscle, shifting the dogma on body sodium balance and its regulation. Emerging evidence suggests that high concentrations of extracellular sodium can directly trigger an inflammatory response in antigen-presenting cells (APCs), leading to hypertension and vascular and renal injury. Importantly, sodium entry into APCs is mediated by the epithelial sodium channel (ENaC). Although the role of the ENaC in renal regulation of sodium excretion and BP is well established, these new findings imply that the ENaC may also exert BP modulatory effects in extrarenal tissue through an immune-dependent pathway. In this review, we discuss the recent advances in our understanding of the pathophysiology of salt-sensitive hypertension with a particular focus on the roles of APCs and the extrarenal ENaC.
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Hipertensión , Cloruro de Sodio Dietético , Presión Sanguínea/fisiología , Células Dendríticas/metabolismo , Canales Epiteliales de Sodio/metabolismo , Humanos , Hipertensión/etiología , Inflamación/complicaciones , Riñón/metabolismo , Sodio/metabolismo , Cloruro de Sodio/metabolismo , Cloruro de Sodio Dietético/efectos adversosRESUMEN
OBJECTIVE: Metabolic syndrome (MetS) and obesity are important public health problems associated with adipose tissue mass. Asprosin, visfatin, and subfatin are new members of which fate in MetS and obesity has not been fully revealed yet. Thus, this study was to investigate the association between asprosin, visfatin, subfatin, and biochemical values, demographic data, and body composition measurement values in MetS patients with and without obesity. PATIENTS AND METHODS: Blood samples were taken from a total of 90 people, including 31 MetS patients with obesity, 29 MetS patients without obesity, and 30 healthy (control). Asprosin, visfatin, and subfatin were studied by the ELISA method. RESULTS: There was a negative correlation between asprosin and Body Mass Index (BMI) in the MetS + Obese group. The correlations between asprosin and urea and fasting insulin (FI) levels in the MetS group were positive and statistically significant (p < 0.05). While there was a statistically significant negative correlation (p < 0.05) between visfatin and BMI in the MetS + Obese group, the correlation with waist circumference in the MetS + Obese and MetS groups was statistically significant and negative (p < 0.05). There was a statistically significant negative relationship (p < 0.05) between aspartate aminotransferase value and visfatin. The results between visfatin values and asprosin and subfatin in all groups were significant (p < 0.05). CONCLUSIONS: There is a direct relationship between circulating amounts of asprosin, visfatin, and subfatin hormones and age, weight, height, diastolic blood pressure, high-density lipoprotein-cholesterol, aspartate aminotransferase, alanine transaminase, and creatinine. Therefore, asprosin, visfatin, and subfatin hormones are the new biomarkers of metabolic turbulence.
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Síndrome Metabólico , Nicotinamida Fosforribosiltransferasa , Biomarcadores , Índice de Masa Corporal , Humanos , ObesidadRESUMEN
Salt-sensitivity of blood pressure is an independent risk factor for cardiovascular disease and affects approximately half of the hypertensive population. While the precise mechanisms of salt-sensitivity remain unclear, recent findings on body sodium homeostasis and salt-induced immune cell activation provide new insights into the relationship between high salt intake, inflammation, and hypertension. The immune system, specifically antigen-presenting cells (APCs) and T cells, are directly implicated in salt-induced renal and vascular injury and hypertension. Emerging evidence suggests that oxidative stress and activation of the NLRP3 inflammasome drive high sodium-mediated activation of APCs and T cells and contribute to the development of renal and vascular inflammation and hypertension. In this review, we summarize the recent insights into our understanding of the mechanisms of salt-sensitive hypertension and discuss the role of inflammasome activation as a potential therapeutic target.
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PURPOSE OF REVIEW: With the wide recognition of the importance of dietary patterns rather than isolated nutrient groups on health outcomes, numerous diet quality indices have been designed to evaluate the overall food intake quality in the last two decades. RECENT FINDINGS: The newest version of the Healthy Eating Index (HEI), HEI-2015, is a diet quality index that measures adherence to the recommendations of the 2015-2020 Dietary Guidelines for Americans. While the key nutrient groups are included in most diet quality indices, differences in other components and the scoring system differentiate HEI. The Healthy Beverage Index (HBI) was recently introduced. Previous literature has confirmed the association of the older versions of HEI with metabolic syndrome, inflammatory markers, and negative health outcomes including cardiovascular disease, type 2 diabetes mellitus, chronic kidney disease, and all-cause mortality. This review presents the existing evidence on the association of HEI-2015 and HBI with health markers and long-term outcome, provides guidance on their use, and identifies persisting challenges such as the development of simple, unified, and objective tools to characterize healthy diets in routine clinical practice.