Search Results (164)

Background: The renin-angiotensin system (RAS), traditionally known for its role in cardiovascular regulation, has also emerged as a key regulator of tumor progression and metastasis. Dysregulation of the RAS components has been implicated in breast cancer due to the significant presence of the RAS-related proteins in the breast tissue. This study aims to identify the dysregulated RAS components and investigate their potential as candidate biomarkers. Methods: A pilot case–control study was carried out with 21 treatment-naïve breast cancer patients and 17 healthy controls. Plasma levels of Ang 1-7, Ang II, ACE2 and selected cytokines (IL-6, IL-8, IL-10 and IFN-γ) were measured using LC-MS/MS and ELISA. ROC curves were used to assess changes in biomarker levels across the RAS components. Results: This pilot cohort showed evidence of altered circulating RAS-related analytes and IL-10 in treatment-naïve breast cancer patients compared with controls. The ratio of Ang 1-7/Ang II was reduced by over two-fold in breast cancer patients (p = 0.0442). While plasma ACE2 was significantly elevated in breast cancer patients (p = 0.0005), IL-10 was significantly suppressed (p = 0.0420). In exploratory logistic regression analysis, ACE2 showed potential as a classifier with improved discrimination when combined with Ang 1-7 and Ang II (AUC = 0.9396 [95% bootstrap CI: 0.84–1.00], accuracy = 92.59% at the Youden-optimized threshold). However, due to the small sample size and methodological limitations, these findings require further validation. Conclusions: In this exploratory pilot study, plasma ACE2, the Ang 1-7/Ang II ratio, and IL-10 showed promising discriminatory performance. However, these findings are hypothesis-generating and require external validation in larger, prospectively enrolled cohorts before any clinical inference can be drawn. Full article

Background: Renin is a hypoperfusion marker and a good index of renin–angiotensin–aldosterone system (RAAS) activity. The purpose of this study was to evaluate whether the plasma renin concentration (PRC) can represent a tissue perfusion marker for predicting mortality in patients with circulatory shock in intensive care. Methods: This prospective study included patients aged 18 years or older who were hospitalized in the intensive care unit (ICU). A total of 69 patients were enrolled, of whom 37 had circulatory shock and were all diagnosed with septic shock according to Sepsis-3 criteria, while 32 patients did not have shock. Patient groups were compared, and survival analysis was carried out. Mortality predictions of PRC, lactate and combined tests (including PRC, mottling scores, central venous saturation of oxygen, C-reactive protein, procalcitonin, and lactate) were investigated with ROC analysis. Results: ICU 28-day mortality was 36.2% (n = 25) and was significantly higher in patients with circulatory shock than those without (CS:21, 56.8% vs. NS:4, 12.5%, respectively, p < 0.001). The survival was significantly higher in patients without circulatory shock than those with shock (17 vs. 16 days; p = 0.038). The increase in mottling score (HR: 1.64 [95%CI: 1.15–2.33]; p < 0.01) and PRC (HR = 1.01 [95%CI: 1.00–1.02]; p < 0.05) levels and the decrease in glomerular filtration rate (GFR) (HR = 0.98 [95%CI: 0.96–0.99]; p < 0.05) were associated with decreased survival times in the ICU patients (p < 0.001). Combined tests yielded better prediction of mortality than PRC level alone. Conclusions: PRC may reflect circulatory shock and predict survival in critically ill patients; however, larger prospective studies incorporating serial PRC measurements are needed before it can be recommended as an independent biomarker of mortality. Full article

COVID-19 perturbs the renin-angiotensin system (RAAS) and inflammatory pathways, shaping disease severity. Soluble ACE2 (sACE2) and angiotensin II (Ang II) are central regulators of vascular and immune homeostasis. We profiled plasma from COVID-19 patients and controls using ELISA, together with 48 cytokine profiling and clinical data. Both sACE2 and Ang II were significantly elevated in patients. Increased Ang II was associated with oxygen supplementation and dyspnea, and negatively correlated with IL-3, whereas sACE2 correlated with IL-13 and FGF. Comorbidities modulated cytokine expression: diabetes mellitus was linked to reduced LIF and MCP-1, hypertension to decreased LIF and increased IP-10, and obesity to elevated IL-12p70. Age correlated with TNF and HGF, and reduced oxygen saturation was associated with lower LIF. These findings reveal that acute COVID-19 disrupts RAAS and amplifies immune dysregulation, with Ang II emerging as a pivotal mediator of respiratory compromise and inflammatory imbalance, underscoring its potential as a biomarker and therapeutic relevance. Full article

Objective: The COVID-19 pandemic has strained healthcare systems and has been associated with substantial morbidity and mortality. Severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2) enters host cells by binding to angiotensin-converting enzyme 2 (ACE2), implicating dysregulation of the renin–angiotensin system (RAS) in COVID-19 pathophysiology. Measurement of circulating RAS components, including ACE and ACE2, may therefore provide an insight into disease severity and underlying mechanisms. Subjects and Methods: In this retrospective cohort study, 224 adults with PCR-confirmed COVID-19 were stratified by World Health Organization disease-severity criteria into asymptomatic, mild, mild-pneumonia, severe, and critical groups. Plasma ACE and ACE2 concentrations were quantified by ELISA. Demographic, clinical, and laboratory data were extracted from electronic medical records. Results and Conclusions: Increasing disease severity was associated with higher mortality, elevated body mass index, and higher viral load estimates. Severe and critical illness was characterized by leukocytosis with neutrophilia, marked lymphopenia, anemia, elevated inflammatory and coagulation markers, renal dysfunction, and hypoalbuminemia. Plasma ACE2 levels declined progressively with increasing severity and were significantly lower in patients with mild-pneumonia, severe, or critical illness compared with asymptomatic or mild cases, showing a strong inverse correlation with severity. In contrast, plasma ACE levels increased significantly with disease severity. The resulting increase in the ACE/ACE2 ratio indicates a progressive shift toward the pro-inflammatory arm of the RAS, providing mechanistic insight into the COVID-19 pathophysiology. Full article

Background: Secondary pseudohypoaldosteronism (PHA) is a rare, transient condition caused by renal tubular resistance to aldosterone, most commonly associated with urinary tract infection (UTI) and/or congenital anomalies of the kidney and urinary tract (CAKUT). It mimics primary adrenal disorders, presenting with life-threatening electrolyte disturbances in early infancy. Case Presentation: We report a male infant admitted twice within the first four months of life with severe dehydration, hyponatremia, hyperkalemia, metabolic acidosis, and acute kidney injury (AKI). Urine cultures grew Klebsiella pneumoniae and later Escherichia coli. Imaging studies demonstrated obstructive CAKUT, including posterior urethral valves, bilateral megaureters, hydronephrosis, and bladder diverticulosis. Congenital adrenal hyperplasia was excluded. Further evaluation showed markedly elevated plasma renin and aldosterone levels, confirming secondary PHA. The patient was successfully treated with intravenous fluids, electrolyte correction, and antibiotic therapy. Subsequently, oral sodium chloride and bicarbonate supplementation were added. Stepwise surgical correction of the urinary tract anomalies was initiated. Conclusions: Secondary PHA should be considered in infants presenting with failure to thrive, dehydration, hyponatremia, and hyperkalemia, particularly in the presence of UTI or CAKUT. Early recognition and differentiation from primary adrenal disorders are essential to prevent life-threatening complications. Prompt correction of electrolyte imbalance and management of the underlying urinary tract pathology are crucial for favorable outcomes. Full article

Obesity is a chronic, highly prevalent disease affecting nearly one-third of the global population and represents a major independent risk factor for heart failure (HF), particularly heart failure with preserved ejection fraction (HFpEF). Excess adiposity—especially visceral and epicardial adipose tissue (EAT)—acts as an active endocrine and immune organ, promoting chronic low-grade inflammation, oxidative stress, endothelial dysfunction, and adverse myocardial remodeling. Expanded EAT exerts both paracrine inflammatory effects and mechanical constraint on the myocardium, contributing to diastolic dysfunction, microvascular impairment, atrial arrhythmogenesis, and elevated filling pressures despite preserved systolic function. Evidence demonstrates a dose–response relationship between increasing body mass index and incident HF. Clinically, obesity-related HFpEF is characterized by concentric left ventricular hypertrophy, impaired relaxation, increased plasma volume, reduced exercise tolerance, and relatively low natriuretic peptide levels, complicating diagnosis. HF management includes traditional treatment with diuretics, renin-angiotensin system inhibitors, β-blockers, mineralocorticoid receptor antagonists, and angiotensin receptor-neprilysin inhibitors. These agents widely remain foundational as they primarily target hemodynamic and neurohormonal pathways in HF. In contrast, sodium–glucose cotransporter 2 inhibitors consistently reduce HF hospitalizations across the ejection fraction spectrum, while glucagon-like peptide-1 receptor agonists and dual incretin therapies (e.g., tirzepatide) promote substantial weight loss, improve symptoms, and demonstrate promising anti-remodeling effects in obesity-related HFpEF. Recognizing obesity-driven HF as a distinct cardiometabolic entity supports an integrated therapeutic strategy combining structured weight reduction with guideline-directed HF polypharmacotherapy to address both hemodynamic burden and upstream adiposity-related mechanisms. Full article

Background: Obstructive sleep apnea (OSA) is associated with lower urinary tract symptoms (LUTS), particularly nocturia, though mechanisms including hypoxia, intrathoracic pressure changes, and hormonal alterations. While age and severity may influence these associations, stratified analyses remain limited. This study examined polysomnographic (PSG) parameters, International Prostate Symptom Score (IPSS) components, and hormonal/electrolyte markers in age- and severity-stratified men with suspected OSA. Methods: In this cross-sectional study, 104 men (mean age 60.8 ± 9.8 years) underwent PSG. Analyses were stratified by age (<60 vs. ≥60 years) and respiratory disturbance index (RDI) severity. Correlations were used to assess PSG indices, IPSS subdomains (irritative, obstructive, quality of life [QoL]), and markers including antidiuretic hormone [ADH], aldosterone, plasma renin activity [PRA], sodium, potassium. Nocturnal polyuria index (NPI ≥ 33%) was calculated in a subset of participants. Pearson correlations, ANOVA, and Kruskal–Wallis tests were used (p < 0.05), with adjustments for multiple comparisons. Results: Moderate OSA predominated (RDI 27.2 ± 20.4 events/h); nocturia affected 61.5% of the cohort. In those <60 years (n = 48), mild RDI correlated with nocturia (r = 0.42, p = 0.028), while severe RDI correlated strongly with the obstructive subscore (r = 0.96, p = 0.009). In those ≥60 years (n = 56), QoL correlated with sleep efficiency (r = 0.48, p = 0.012) and total sleep time (r = 0.46, p = 0.015). Severe RDI was associated with higher IPSS (14.5 ± 6.2 vs. 10.5 ± 4.8, p = 0.028) and nocturia (3.5 ± 1.7 vs. 2.4 ± 1.1, p = 0.02). ADH was significantly lower in severe OSA (1.4 ± 0.8 vs. 2.7 ± 1.1 pg/mL, p = 0.03). Conclusions: Age and OSA severity modulate PSG–LUTS–hormonal associations. Younger men exhibit hypoxia-linked obstructive symptoms, whereas older men experience sleep fragmentation that impacts QoL. ADH suppression is associated with severe OSA. Full article

Traffic-related air pollution (TRAP) is known to contribute to oxidative stress in the central nervous system (CNS) and has been linked to increased risk of Alzheimer’s disease (AD). Alterations in the renin–angiotensin system (RAS), specifically increased angiotensin II (Ang II) signaling via the angiotensin II type 1 (AT₁) receptor, are implicated in increased oxidative stress in the CNS via activation of NADPH oxidase (NOX). As exposure to TRAP may further elevate AD risk, we investigated whether exposure to inhaled mixed gasoline and diesel vehicle emissions (MVE) promotes RAS-dependent expression of factors that contribute to AD pathophysiology in an apolipoprotein E-deficient (ApoE^−/−) mouse model. Male ApoE^−/− mice (6–8 weeks old) on a high-fat diet were treated with either an ACE inhibitor (captopril, 4 mg/kg/day) or water and exposed to filtered air (FA) or MVE (200 µg PM/m³) for 30 days. MVE exposure elevated plasma Ang II, inflammation, and oxidative stress in the hippocampus, associated with increased levels of Aph-1 homolog B (APH1B), a gamma-secretase subunit, and beta-secretase 1 (BACE1), involved in Aβ production. Each of these endpoints was normalized with ACEi treatment. These findings indicate that TRAP exposure in ApoE^−/− mice drives a RAS- and NOX-dependent oxidative and inflammatory response and shifts Aβ processing towards an amyloidogenic profile before overt Aβ deposition, suggesting a potential therapeutic approach for air pollution-induced AD risk. Full article

Background/Objectives: We evaluated Goreisan, a traditional Chinese medicine, for its effects on nephrotic syndrome in a rat model. Methods: Male Sprague–Dawley rats underwent right nephrectomy at 5 weeks of age, followed by adriamycin administration (5 mg/kg) at 6 and 8 weeks of age to induce nephrotic syndrome. At 10 weeks, rats were divided into three groups: vehicle (control), Goreisan 0.5 g/kg (GL), and Goreisan 1.0 g/kg (GH). Goreisan was administered daily for 4 weeks. At 14 weeks, blood, urine, mRNA expressions, and kidney histopathology were analyzed. Data were analyzed using one-way ANOVA followed by Tukey–Kramer post hoc testing. Results: Goreisan prevented worsening kidney function, with reduced glomerular and tubulointerstitial damage, lower systemic and intrarenal 8-hydroxy-2′-deoxyguanosine levels, and lower plasma aldosterone levels and expression of intrarenal renin–angiotensin–aldosterone system (RAAS)-related factors. Urine volume significantly increased in GL and GH groups compared with the control group. In the GH group, urine volume increased markedly (Δ urine volume: 10.0 ± 2.6 mL/day), whereas it tended to decrease in the Vehicle group (Δ urine volume: −1.3 ± 2.5 mL/day). Urine osmolality was lower in the GH group, with a larger decrease in Δ urine osmolality (−616.3 ± 132.8 mOsm/L). These changes occurred without an increase in urinary sodium excretion, suggesting an aquaretic effect independent of natriuresis. Creatinine clearance (CCr/kg) declined markedly in the Vehicle group but was significantly preserved in the GH group (Δ CCr/kg: −2.2 ± 0.19 vs. −0.7 ± 0.28), indicating renoprotective effects. No differences were found in serum arginine–vasopressin levels. Real-time PCR and immunohistochemical staining showed no significant differences in aquaporin (AQP) mRNA expression (AQP1, AQP2, AQP3, and AQP4), but AQP2 localization to the apical membrane in the collecting ducts was reduced with Goreisan treatment. Conclusions: Goreisan demonstrates kidney-protective and diuretic effects in nephrotic syndrome, potentially through reducing systemic oxidative stress, modulating RAAS activation, and altering AQP2 trafficking. Full article

Objective: We aimed to assess the expression and localization of renin-angiotensin system (RAS) receptors in lung tissue and the plasma concentration of related peptides in IPF patients. Materials and Methods: This case–control study involved 19 patients from southern Brazil undergoing lung resection or transplantation. Plasma levels of Angiotensin I, II, A, 1-7, Alamandine were measured via liquid chromatography–tandem mass spectrometry. Lung tissue expression and localization of angiotensin type 1 (AT1), Mas, and Mas-related G-protein-coupled receptor D (MrgD) receptors were evaluated using Western blot and immunohistochemistry. Clinical data and the 6-min walk test were analyzed to correlate receptor expression with lung function and oxygen dependence. Results: IPF patients showed reduced forced vital capacity (FVC) at 49 ± 13% and forced expiratory volume (FEV1) at 51 ± 14%, with a 60% increase in oxygen dependence. Plasma peptide concentrations were similar between the groups, except for Angiotensin I, which was significantly higher in the control group. In IPF lungs, AT1 and Mas receptors were expressed 2.31 and 2.13 times more, respectively, while MrgD expression was lower. Mas receptors were mostly found in bronchiole areas, whereas MrgD was predominant in the lung parenchyma. Conclusions: This study indicates that the RAS operates independently within tissue, in addition to its systemic functions, highlighting distinct differences between tissue and plasma RAS activities. The distinct roles of MrgD and Mas receptors in lung structure and function could be pivotal for new therapies, potentially leading to more effective IPF treatments. Full article

Background: Despite anatomically successful surgical correction, postoperative hypertension remains a significant concern in patients with coarctation of the aorta, even when repair is performed during infancy. Inflammation and neurohormonal activation have been proposed as contributing mechanisms. Objective: To investigate the association between preoperative inflammatory biomarkers—specifically the interleukin-6 (IL-6) to tumor necrosis factor-alpha (TNF-α) ratio—and the development of hypertension in patients with successful isolated coarctation of the aorta repair under one year of age. Methods: This observational study included 42 infants with isolated CoA. Clinical, echocardiographic, and biochemical parameters were analyzed. Preoperative plasma levels of IL-6, TNF-α, von Willebrand factor (vWF), and renin were measured. Patients were classified based on hypertensive status at 2-year follow-up. Univariate and multivariate logistic regression analyses were performed to identify predictors of postoperative hypertension. Results: Hypertension was diagnosed in 16 out of 41 patients (39%) at follow-up. A preoperative IL-6/TNF-α ratio > 2 was an independent predictor in multivariate analysis for postoperative HT (OR = 6.1, 95% CI = 6.23–9.31, p = 0.02). Conclusions: In this small single-center cohort, an elevated IL-6/TNF-α ratio was associated with postoperative hypertension after coarctation repair. These exploratory findings should be considered hypothesis-generating and warrant confirmation in larger, multicenter studies. Full article

Background: Ibrutinib has been associated with an increased risk of cardiovascular adverse events (CVAEs), including atrial fibrillation (AF), hypertension (HTN), heart failure (HF), and ventricular arrhythmias (VAs). However, baseline predictors of CVAEs remain poorly characterized. In this study, we sought to identify baseline patient characteristics associated with the occurrence of ibrutinib-related CVAEs, with particular emphasis on parameters linked to the renin–angiotensin system. Methods: We conducted a prospective, single-center cohort study of consecutive patients treated with ibrutinib for B-cell malignancy, with systematic assessment of a predefined panel of potential predictors of CVAEs at baseline (NCT03678337). These predictors included demographic and clinical variables, 16 circulating biomarkers related to inflammation, fibrosis, and neurohormonal activation, as well as nine echocardiographic parameters. The primary objective was to evaluate the association between baseline patient characteristics and the occurrence of CVAEs from ibrutinib initiation through the end of follow-up. The CVAE endpoint was defined as a composite of atrial fibrillation, new or worsening hypertension, new or worsening heart failure, and ventricular arrhythmias. Statistical analyses were performed using the Wilcoxon–Mann–Whitney test or Fisher’s exact test, with a p-value < 0.05 considered statistically significant. Results: Among the 25 patients included, 7 experienced a total of 9 CVAEs over a median follow-up of 672 days. Elevated baseline plasma renin levels (>1336.10 pg/mL) were significantly associated with CVAEs occurrence (57% vs. 11%, p = 0.032). Higher baseline plasma aldosterone levels (>488.95 pg/mL) were also observed in patients who developed CVAEs, although this association did not reach statistical significance (p = 0.058). Conclusions: Baseline plasma renin level was univariably associated with CVAEs occurrence, while plasma aldosterone levels were higher among patients with CVAEs but did not reach statistical significance. These findings provide preliminary insights into the mechanisms underlying ibrutinib-related cardiovascular toxicity, suggesting a potential role for the renin–angiotensin–aldosterone system. Confirmation of this hypothesis, however, will require larger, dedicated studies. Full article

Background/Objective: Sacubitril/Valsartan are a combination drug approved for heart failure treatment, known to enhance natriuretic peptide activity and inhibit the renin–angiotensin–aldosterone system (RAAS). While its clinical efficacy is well-established, its broader impact on human metabolism remains insufficiently characterized. This study aimed to explore the time-resolved metabolic changes induced by Sacubitril/Valsartan in healthy individuals using an untargeted metabolomics approach. Methods: Fourteen healthy male volunteers received a single oral dose of Sacubitril/Valsartan (200 mg; 97.2 mg Sacubitril and 102.8 mg Valsartan) across two phases separated by a two-week washout period. Plasma samples were collected at eight individualized time points based on pharmacokinetic profiles. Metabolites were extracted and analyzed using high-resolution liquid chromatography–mass spectrometry (LC-QToF HRMS). Data processing included peak alignment, annotation via HMDB and METLIN, and statistical modeling through multivariate (PLS-DA, OPLS-DA) and univariate (ANOVA with FDR correction) analyses. Results: Out of 20,472 detected features, 13,840 were retained after quality filtering. A total of 315 metabolites were significantly dysregulated (FDR p < 0.05), of which 31 were confidently annotated as endogenous human metabolites. Among these, key changes were observed in the pyrimidine metabolism pathway, particularly elevated levels of uridine triphosphate (UTP) associated with cellular proliferation and metabolic remodeling. OPLS-DA models demonstrated clear separation between pre-dose and Cmax samples (R²Y = 0.993, Q² = 0.768), supporting the robustness of the time-dependent effects. Conclusions: This is the first study to characterize the dynamic metabolomic signature of Sacubitril/Valsartan in healthy humans. The findings reveal a distinctive perturbation in pyrimidine metabolism, suggesting possible links to drug mechanisms relevant to cardiac cell cycle regulation. These results underscore the utility of untargeted pharmacometabolomics in uncovering systemic drug effects and highlight potential biomarkers for monitoring therapeutic response or guiding precision treatment strategies in heart failure. Full article

Background/Objectives: Nelumbo nucifera Gaertn. (lotus) seeds have traditionally been used to treat hypertension, though their mechanisms remain unclear. This study investigated the antihypertensive effects of lotus seed extract (LSE) and its mechanisms in rats with N^ω-nitro-L-arginine methyl ester (L-NAME)-induced hypertension. Methods: Male Sprague Dawley rats received L-NAME (40 mg/kg/day) in drinking water and were treated orally with LSE (5, 10, or 100 mg/kg/day), captopril (5 mg/kg/day), or a combination of LSE and captopril (2.5 mg/kg/day each) for 5 weeks. Hemodynamic parameters and histological changes in the left ventricle and aorta were assessed. Mechanistic studies included measurements of plasma nitric oxide (NO) metabolites, malondialdehyde (MDA), superoxide dismutase (SOD) activity, angiotensin II (Ang II), angiotensin-converting enzyme (ACE) activity, and protein expression via western blot. Results: L-NAME elevated systolic blood pressure and induced cardiovascular remodeling, oxidative stress, and renin-angiotensin system activation. LSE treatment reduced blood pressure, improved antioxidant status, increased NO bioavailability, and downregulated gp91^phox and AT₁R expression. The combination of low-dose LSE and captopril produced stronger effects than LSE alone, with efficacy comparable to captopril. Conclusions: These findings suggest that LSE exerts antihypertensive effects via antioxidant activity and inhibition of the renin-angiotensin system, supporting its potential as an adjunct therapy for hypertension. Full article

The renin–angiotensin system (RAS) plays a central role in cardiovascular regulation and has gained prominence in the pathogenesis of Coronavirus Disease 2019 (COVID-19) due to the critical function of angiotensin-converting enzyme 2 (ACE2) as the entry receptor for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Angiotensin IV, but not angiotensin II, has recently been reported to enhance the binding between the viral spike protein and ACE2. To investigate the virological significance of this effect, we developed a single-round infection assay using SARS-CoV-2 viral-like particles expressing the spike protein. Our results demonstrate that while angiotensin II does not affect viral infectivity across concentrations ranging from 40 nM to 400 nM, angiotensin IV enhances viral entry at a low concentration but exhibits dose-dependent inhibition at higher concentrations. These findings highlight the unique dual role of angiotensin IV in modulating SARS-CoV-2 entry. In silico molecular docking simulations indicate that angiotensin IV was predicted to associate with the S1 domain near the receptor-binding domain in the open spike conformation. Given that reported plasma concentrations of angiotensin IV range widely from 17 pM to 81 nM, these levels may be sufficient to promote, rather than inhibit, SARS-CoV-2 infection. This study identifies a novel link between RAS-derived peptides and SARS-CoV-2 infectivity, offering new insights into COVID-19 pathophysiology and informing potential therapeutic strategies. Full article