Search Results (419)

The pivotal role of angiotensin II (AngII) in cardiovascular disease has been firmly established, as evidenced by a robust body of literature and the broad clinical application of AngII-inhibiting therapies. AngII type 1 receptor is the primary mediator of AngII action, and its activation initiates a multitude of cellular responses that contribute to the development of hypertension, structural changes in the heart and vasculature, and damage to target organs. This review examines AngII from a different perspective, exploring the link between the renin–angiotensin–aldosterone system and cardiovascular risk beyond hypertension, with particular emphasis on atherosclerosis development and progression. Full article

Cardiorenal syndrome (CRS) is a multifactorial clinical condition characterized by the bidirectional deterioration of cardiac and renal function, driven by mechanisms such as renin–angiotensin–aldosterone system (RAAS) overactivation, systemic inflammation, oxidative stress, endothelial dysfunction, and fibrosis. The aim of this narrative review is to explore the key molecular pathways involved in CRS and to highlight emerging therapeutic approaches, with a special emphasis on nutritional interventions. We examined recent evidence on the contribution of mitochondrial dysfunction, uremic toxins, and immune activation to CRS progression and assessed the role of dietary and micronutrient factors. Results indicate that a high dietary intake of sodium, phosphorus additives, and processed foods is associated with volume overload, vascular damage, and inflammation, whereas deficiencies in potassium, magnesium, and vitamin D correlate with worse clinical outcomes. Anti-inflammatory and antioxidant bioactives, such as omega-3 PUFAs, curcumin, and anthocyanins from maqui, demonstrate potential to modulate key CRS mechanisms, including the nuclear factor kappa B (NF-κB) pathway and the NLRP3 inflammasome. Gene therapy approaches targeting endothelial nitric oxide synthase (eNOS) and transforming growth factor-beta (TGF-β) signaling are also discussed. An integrative approach combining pharmacological RAAS modulation with personalized medical nutrition therapy and anti-inflammatory nutrients may offer a promising strategy to prevent or delay CRS progression and improve patient outcomes. Full article

Hypertension is an important risk factor for cardiovascular diseases. High salt intake when consumed with excess fructose enhances hypertension and resultant cardiovascular disease. Usually, the small intestine absorbs dietary fructose, and the proximal tubule of kidney reabsorbs filtered fructose into the circulation with the help of different transporters including SGLT4 and SGLT5. Very recently, SGLT5 mRNA has also been found to be expressed in the heart. High-fructose diet stimulates the sympathetic nervous system and renin–angiotensin–aldosterone (RAAS) activity, of which both are responsible for endothelial dysfunction and are associated with salt-sensitive hypertension. Few studies exist regarding the effects of SGLT4 and SGLT5 on cardiovascular function and blood pressure. However, SGLT4 gene knockout does not alter fructose-associated impact on blood pressure. In contrast, blood pressure does not increase in SGLT5 knockout rats even during fructose consumption. Given that limiting fructose and salt consumption as a public health strategy has proven challenging, we hope that studies into SGLT4 and SGLT5 transporters will open new research initiatives to address salt-sensitive hypertension and cardiovascular disease. This review highlights current information about SGLT4 and SGLT5 on fructose absorption, salt-sensitive hypertension, cardiovascular disease and points the way for the development of therapeutic fructose inhibitors that limit adverse effects. Full article

Background/Objectives: Perioperative hypotension during kidney transplantation poses a risk to graft function and survival. Angiotensin II (AngII) is an endogenous vasoconstrictor targeting the renin–angiotensin–aldosterone system (RAAS) to increase blood pressure. Black patients may have a different response to synthetic angiotensin II (AT2S) compared to non-Black patients, given differential expressions in renin profiles. The purpose of this study is to assess the difference between Black and non-Black patients in total vasopressor duration and usage when AT2S is first line for hypotension during kidney transplantation. Methods: A single-center, retrospective cohort study comparing Black and non-Black patients who required AT2S as a first-line vasopressor for hypotension during the perioperative period of kidney transplantation. Results: The primary outcome evaluating total usage of vasopressors found that Black patients required longer durations of vasopressors (36.9 ± 66.8 h vs. 23.7 ± 31.7 h; p = 0.022) but no difference in vasopressor amount (0.07 ± 0.1 NEE vs. 0.05 ± 0.1 NEE; p = 0.128) compared to non-Black patients. Regression analysis found that body weight was associated with the duration of vasopressors (p < 0.05), while baseline systolic blood pressure was inversely associated with it. Longer duration of vasopressors and duration of transplant surgery were associated with delayed graft function in regression analysis (p < 0.05). Conclusions: Black patients had a longer duration of vasopressors, but this was not driven by differences in usage of AT2S. As baseline weight was significantly higher in Black patients and associated with duration of usage, perhaps the metabolic differences in our Black patients led to the observed differences. Regardless, longer durations of vasopressors were associated with delayed graft function, making this an area of utmost importance for continued investigation. Full article

The renin–angiotensin–aldosterone system (RAAS) plays a central role in cardiovascular and renal homeostasis and is increasingly recognized for its broad immunomodulatory effects. Pharmacological RAAS inhibition, primarily via angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs), has demonstrated therapeutic value beyond its use in hypertension and heart failure, extending to autoimmune, infectious, oncologic, and neurodegenerative conditions. ACEIs and ARBs modulate both innate and adaptive immune responses through Ang II-dependent and -independent mechanisms, influencing macrophage polarization, T-cell differentiation, cytokine expression, and antigen presentation. Notably, ACEIs exhibit Ang II-independent effects by enhancing antigen processing and regulating amyloid-β metabolism, offering potential neuroprotective benefits in Alzheimer’s disease. ARBs, particularly telmisartan and candesartan, provide additional anti-inflammatory effects via PPARγ activation. In cancer, RAAS inhibition affects tumor growth, angiogenesis, and immune surveillance, with ACEIs and ARBs showing distinct yet complementary impacts on tumor microenvironment modulation and chemotherapy cardioprotection. Moreover, ACEIs have shown promise in autoimmune myocarditis, colitis, and diabetic nephropathy by attenuating inflammatory cytokines. While clinical evidence supports the use of centrally acting ACEIs to treat early cognitive decline, further investigation is warranted to determine the long-term outcomes across disease contexts. These findings highlight the evolving role of RAAS inhibitors as immunomodulatory agents with promising implications across multiple systemic pathologies. Full article

Background: SARS-CoV-2 infection has been associated with long-term health consequences, including dysregulation of the renin–angiotensin–aldosterone system (RAAS). This study aimed to evaluate long-term changes in selected RAAS-related biochemical parameters in repeat convalescent plasma donors, focusing on enzymes and peptides involved in vascular regulation and inflammation. Methods: Thirty repeat convalescent plasma donors were enrolled, each providing four serum samples at defined time points post-infection. Samples were collected during Period 1 (≤60 days), Period 2 (61–90 days), Period 3 (91–120 days), and Period 4 (>120 days) after confirmed SARS-CoV-2 infection. The analyzed parameters included angiotensin I (Ang I), angiotensin II (Ang II), angiotensin 1–7 (Ang 1–7), angiotensin 1–9 (Ang 1–9), ACE, ACE2, ADAM10, and ADAM17. Concentrations were determined using ELISA assays. The control group consisted of pre-pandemic serum samples from healthy individuals. Results: An initial post-infection increase was observed in most parameters, particularly in Period 1. Over time, levels of several markers declined, yet Ang 1–7 and Ang 1–9 remained elevated compared to controls even beyond 120 days. Significant correlations (p < 0.05) were found between ADAM10, ADAM17, and angiotensin peptides, suggesting prolonged RAAS modulation. Metalloproteinases were notably elevated early after infection, potentially contributing to inflammatory and cardiovascular responses. Conclusions: The findings indicate a transient but measurable biochemical response of the RAAS following SARS-CoV-2 infection, with most parameters normalizing after 120 days. However, the sustained elevation of certain markers suggests a potential long-term impact on vascular homeostasis, warranting further investigation. Full article

The renin-angiotensin-aldosterone system (RAAS) is a hormone system that controls blood pressure and fluid and electrolyte balance. Angiotensin II, a key effector, is produced from angiotensin I by angiotensin-converting enzyme (ACE) and exerts its effects through binding to its type 1 (AT1R) or type 2 (AT2R) receptors. AT1R activation promotes vasoconstriction, oxidative stress, endothelial dysfunction, peripheral vascular resistance, and atherosclerosis, all of which substantially contribute to cellular senescence and organismal ageing. Conversely, AT2R activation counteracts these effects by inducing vascular relaxation and attenuating vascular cell proliferation and migration, offering protection against occlusive vascular disease. Additionally, conversion of angiotensin II to angiotensin (1-7) or angiotensin I to angiotensin (1-9) by ACE2 provides further cardiovascular protection by lowering oxidative stress, inflammation, and abnormal cell growth. Bearing these in mind, measures to control angiotensin II synthesis or receptor activity have been at the forefront of antihypertensive treatment. This paper briefly reviews the RAAS and explores the dual role of angiotensin II in promoting disease and mediating vascular protection, with a focus on its impact on ageing and cardiovascular pathology. Full article

Contrast-associated acute kidney injury (CA-AKI) is a known complication of endovascular procedures using an iodinated contrast medium (ICM), especially in patients with peripheral artery disease (PAD) and chronic kidney disease (CKD). This retrospective study evaluated the incidence and risk factors of AKI in patients with PAD and CKD undergoing diagnostic angiography or endovascular intervention using carbon dioxide (CO₂) as the primary contrast medium, with optional bailout ICM use. We included 340 patients who underwent peripheral angiography or intervention between September 2014 and December 2020. CO₂ was used as the primary contrast medium for all patients, as the majority were classified with advanced CKD stages 3–5 according to the Kidney Disease: Improving Global Outcomes (KDIGO) guidelines. Bailout ICM was used in 80% of cases (mean 21.23 ± 14.09 mL). Postinterventional AKI occurred in 13.2% of patients, with over 70% classified as stage 1. Seven patients required new dialysis within 7 days. Multivariate analysis identified hypertension, heart failure, and coronary artery disease as independent AKI risk factors. Statin or Renin–Angiotensin–Aldosteron System (RAAS) inhibitor use and higher pre-interventional GFR were protective. AKI remains common in patients undergoing CO₂-guided peripheral procedures. Further studies are needed to explore underlying mechanisms and outcomes. Full article

Gastrointestinal (GI) complications are common in diabetes, but the role of the local renin-angiotensin-aldosterone system (RAAS) in gut remodeling remains unclear. This study examined histomorphometric alterations, oxidative stress, and systemic and tissue-specific angiotensin converting enzyme (ACE) and ACE2 activity in streptozotocin (STZ)-induced diabetic rats. Adult male Wistar rats (n = 24) were assigned to control (CTRL), diabetic (STZ), and diabetic groups treated with losartan (STZ-LOS, 20 mg/kg/day) or finerenone (STZ-FIN, 10 mg/kg/day). After 14 days, gut samples were collected from the stomach, duodenum, jejunum, ileum, and colon for histology, glutathione measurements (GSH/GSSG), and ACE/ACE2 activity assessment. Diabetic rats exhibited increased GI wall thickness—particularly in the mucosal and muscular layers—elevated GSSG levels, and a reduced GSH/GSSG ratio. Losartan prevented these changes, whereas finerenone did not produce a significant effect. Circulating ACE and ACE2 levels were elevated, but the ACE2/ACE ratio remained unchanged. Locally, ACE activity increased across gut segments, whereas ACE2 remained stable, lowering the ACE2/ACE ratio, particularly in the duodenum and jejunum. The Z-FHL/h-HL ratio was above 1 across segments but decreased in these same regions (jejunum and duodenum). These findings highlight the protective role of losartan against diabetic GI remodeling via AT₁R blockade and suggest complex, segment-specific RAAS regulation in diabetic gut pathology. Full article

Background/Objectives: Patients with chronic kidney disease (CKD) are associated with a significantly elevated cardiovascular risk. The incidence and prevalence of mediated cardiac disorders and major adverse cardiac events (MACEs), such as heart failure, arrhythmias, acute coronary syndrome (ACS) based on coronary artery disease (CAD), stroke, venous thromboembolism, and peripheral artery disease, are significantly higher in CKD patients as compared with the general population. Methods: This narrative review summarizes the current clinical understanding, the pathophysiological mechanisms, and the clinical consequences in the context of cardiovascular risk and disease in CKD. Results: The impact of CKD on mediated cardiovascular disorders and elevated MACE prevalence is complex and multifactorial. The underlying mechanisms involve various traditional cardiovascular risk factors, such as arterial hypertension, smoking, dyslipidemia, and diabetes. Furthermore, CKD-specific molecular and pathophysiological factors, such as chronic inflammation and associated oxidative stress and endothelial cell dysfunction, pro-coagulatory status, uremic toxins and uremic lipids, progressive vascular calcification, and alterations in the regulation of the renin–angiotensin–aldosterone system (RAAS) and sympathetic activation cause an increased cardiovascular risk. Conclusions: Understanding the complex disease mechanisms between CKD and elevated cardiovascular risk might contribute to optimizing individual patients’ risk stratification and result in individualized diagnostic and treatment strategies via appropriate clinical biomarker application and individualized anti-inflammatory approaches. Full article

The venom of Nemopilema nomurai jellyfish represents a promising source of bioactive compounds with potential pharmacological applications. In our previous work, we identified two novel angiotensin-converting enzyme (ACE)-inhibitory peptides—IVGRPLANG (896.48 Da) and IGDEPRHQYL (1227.65 Da)—isolated from N. nomurai venom hydrolysates via papain digestion. In this study, we conducted a detailed biochemical and computational characterization of these peptides. The IC₅₀ values were determined to be 23.81 µM for IVGRPLANG and 5.68 µM for IGDEPRHQYL. Kinetic analysis using Lineweaver–Burk plots revealed that both peptides act as competitive ACE inhibitors, with calculated inhibition constants (K_i) of 51.38 µM and 5.45 µM, respectively. To assess the structural stability of the ACE–peptide complexes, molecular dynamics simulations were performed. Root mean square deviation (RMSD) and root mean square fluctuation (RMSF) analyses provided insights into complex stability, while interaction fraction analysis elucidated key bond types and residue–ligand contacts involved in binding. Furthermore, a network pharmacology approach was employed to predict therapeutic targets within the renin–angiotensin–aldosterone system (RAAS). Eleven target proteins were identified: IVGRPLANG was associated with REN, ACE, CTSB, CTSS, and AGTR2; IGDEPRHQYL was linked to REN, AGT, AGTR1, AGTR2, KNG1, and BDKR2. Molecular docking analyses using HADDOCK software (version 2.4) were conducted for all targets to evaluate binding affinities, providing further insight into the peptides’ therapeutic potential. Full article

A growing body of evidence suggests the potent anti-inflammatory properties of the newly discovered arm of the renin–angiotensin–aldosterone system, ACE2/Ang-(1–7)/MasR, in various disease conditions. Our group was the first to report the anti-inflammatory properties of the Ang-(1–7) polypeptide in the murine dextran sulfate sodium (DSS) colitis model. Both its short half-life and high degradation rate limit the clinical use of Ang-(1–7). One way to compensate for these limitations is through the use of the non-peptide MasR agonist AVE0991. Herein, we aimed to study the anti-inflammatory effects of AVE0991 using the DSS model and the possible synergistic effects with other clinically available medications. Colitis severity was determined using both prophylactic and treatment approaches by gross anatomical and histological assessments and daily weight changes. The colonic expression level/activity of various pro-inflammatory and adhesion molecules was determined by western blotting, immunofluorescence, and proteomic profiling. We showed that AVE0991 treatment significantly reduced colitis severity more effectively with the prophylactic than the treatment approach. An additive anti-inflammatory effect was observed in the combination regimen with AVE0991 plus azathioprine, which was mediated through an increased colonic expression level of mucins and focal adhesion kinase, decreased colonic activity of p38 MAPK and Akt, and decreased colonic expression level of various pro-inflammatory mediators. In conclusion, these data suggest a promising potential for the non-peptide MasR agonist AVE0991 in the treatment of inflammatory bowel disease. Full article

Heart failure (HF) remains a global health burden with high morbidity and mortality, despite significant pharmacological advances. Vitamin D deficiency (VDD) is commonly observed in HF patients and may exacerbate disease progression through various pathophysiological mechanisms, including activation of the renin–angiotensin–aldosterone system, inflammation, oxidative stress, and impaired calcium homeostasis. While vitamin D (VD) supplementation may positively influence surrogate markers in selected patient groups—particularly those with reduced ejection fraction or severe vitamin D deficiency—its effect on primary endpoints such as mortality or HF-related hospitalization varies significantly across studies and patient populations. As a result, while VD supplementation may benefit VD-deficient HF patients, current evidence does not support routine administration across the whole HF population. It is still a matter of debate whether VDD belongs to prognostic markers of worse outcomes in HF or is instead their potential cause. Therefore, the clinical utility of VD in HF management remains underexplored. This review aims to assess the evidence regarding vitamin D status and its supplementation in the context of HF, with a focus on different HF phenotypes: reduced (HFrEF), mildly reduced (HFmrEF), and preserved ejection fraction (HFpEF). The aim is to synthesize findings from novel observational studies, randomized controlled trials, and meta-analyses that shed light onto this intricate relationship and may be valuable in everyday clinical practice. Full article

Heart failure (HF) is a major socioeconomic problem worldwide, associated with high morbidity and mortality due to several underlying diseases. HF is driven by several closely linked mechanisms whose effects are mutually reinforcing. Some of the signalling pathways involved in the progression of HF may initially be compensatory, such as the renin–angiotensin–aldosterone system (RAAS), whose hyperactivation plays a central role in the progression of HF by promoting fluid retention, inflammation, oxidative stress (OS), and myocardial dysfunction. Fluid retention is also promoted by the action of neprilysin, which contrasts natriuresis and vasodilation. Among the compensatory and subsequently maladaptive systems, chronic hyperactivation of the sympathetic nervous system (SNS) exacerbates maladaptive remodelling and drives the progression of HF. At the molecular level, mitochondrial dysfunction and inflammatory substances are involved in the development of a state of systemic oxidative stress and inflammation. The aim of the following manuscript was to revise the pathophysiology and role of OS in HF, focusing on the current knowledge of the molecular pathways involved. Full article

Background/Objectives: Current guidelines for the management of type 2 diabetes (T2D) strongly recommend the use of sodium–glucose cotransporter 2 inhibitors (SGLT2is) in patients with chronic kidney disease (CKD) to alleviate cardiorenal risk. However, the implementation of this guidance in daily practice remains limited. In a real-world setting, we evaluated the frequency of SGLT2i use in elderly people with T2D and CKD and compared patient profiles between SGLT2i users and non-users. Methods: We retrospectively analyzed the medical records of individuals over 65 years of age followed in outpatient internal medicine clinics in Greece. Demographic and laboratory parameters, comorbidity profiles, and medication use were recorded and compared between the SGLT2i and non-SGLT2i groups. Results: The analysis included 135 patients with T2D and CKD, of whom the majority (57.8%) did not receive SGLT2i treatment. The patients in the SGLT2i group were younger (p = 0.006), had higher creatinine (p = 0.001) and hemoglobin (p = 0.001) values, and lower levels of uric acid (p = 0.025) than the participants not treated with SGLT2is. Heart failure rates were similar between the groups (p = 0.252). There was no difference in the use of renin–angiotensin–aldosterone system inhibitors (p = 0.210); in contrast, treatment with glucagon-like peptide 1 receptor agonists was more frequent in the group receiving SGLT2is compared to the group not treated with gliflozins (p = 0.002). Conclusions: Real-world data confirm the benefits of SGLT2i treatment for elderly people with T2D and CKD. However, our findings indicate that the use of gliflozins in this population of patients remains suboptimal, highlighting the need for greater vigilance among prescribers to align with existing guidelines. Full article