Search Results (1,022)

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: Real-world evidence shows alarmingly suboptimal utilization of guideline directed medical therapy (GDMT) in heart failure with reduced ejection fraction (HFrEF). One of the barriers of GDMT implementation appears to be concerns about the potential development of drug-related adverse events (AEs), particularly in high-risk patients. This study aimed to evaluate whether advanced HFrEF (AHF) patients can be up-titrated safely and whether AHF predisposes individuals to the occurrence of putatively drug-related AEs. Methods: A total of 373 HFrEF patients with documented baseline, 2 months, and 12 months visits were analyzed for utilization and target dosages (TDs) of HF drugs. Successful up-titration and AEs were evaluated for different stages of HF reflected by N-terminal pro-B type natriuretic peptide (NT-proBNP) (<1000 pg/mL, 1000–2000 pg/mL, >2000 pg/mL). Results: A stepwise increase in HF medications was observed for all drug classes during follow-up. At 12 months, 73%, 75%, 62%, 86%, and 45% of patients received ≥90% of TDs of beta-blockers (BBs), renin–angiotensin system inhibitors (RASis), mineralocorticoid receptor antagonists (MRAs), sodium–glucose cotransporter-2 inhibitors (SGLT2 i), and triple-therapy, respectively. Predictors of successful up-titration in logistic regression were baseline HF drug TDs, estimated glomerular filtration rate (eGFR), and potassium, but not NT-proBNP or age. The development of AEs was rare, with hyperkalemia as the most common event (34% at 12 months). AEs were comparable in all stages of HF. However, the development of hyperkalemia was more frequent in patients with higher NT-proBNP and also accounted for most cases of incomplete up-titration. Conclusions: This study suggests that with dedicated protocols and frequent visits, GDMT can be successfully implemented across all stages of HFrEF, including patients with AHF. 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

Aminopeptidase A (APA) cleaves a single aspartate residue from the amino terminus of peptides within the renin angiotensin system (RAS). Since several RAS peptides contain an N-terminal aspartate, we developed an assay to evaluate the effect of recombinant APA on the cleavage of Ang I, Ang II, Ang-(1-7), Ang-(1-9), and Ang-(1-12). The latter peptide has been proposed to be a functional Ang II-forming substrate with a hypertensive action attributable to the formed Ang II acting on AT1 receptors. Here we investigated the following: (a) the hydrolytic action of APA on Ang-(1-12), Ang I (1-10), Ang-(1-9), Ang II and Ang-(1-7) and (b) whether Ang-(1-12) pressor activity is altered by recombinant APA (r-APA) or genetic APA deficiency. We found that (a) r-APA cleaves the N-terminal aspartate of not only Ang II but also [Ang-(1-12), Ang I (1-10), Ang-(1-9)] and [Ang-(1-7)]; (b) the pressor activity of Ang-(1-12) was abolished in the presence of Lisinopril or Telmisartan; (c) r-APA significantly attenuated the pressor activities of infused Ang I and Ang II but not Ang-(1-12); and (d) r-ACE2 also did not attenuate the pressor effect of infused Ang-(1-12). Thus, in addition to increasing blood pressure indirectly via the formation of Ang II, Ang-(1-12) increases blood pressure by an Ang II-independent mechanism. We conclude that APA has an antihypertensive effect attributable to rapid degradation of Ang II, and this action may have a therapeutic potential in forms of hypertension that are Ang II-dependent. In addition, APA metabolizes Ang-(1-12), a peptide that has a prohypertensive action, in part, as a source of Ang II formation but also by a yet to be determined action independent of Ang II. Full article

Metabolic dysfunction-associated fatty liver disease (MAFLD), a recently proposed term to replace non-alcoholic fatty liver disease (NAFLD), emphasizes the critical role of metabolic dysfunction and applies broader diagnostic criteria. Diagnosis of MAFLD requires evidence of hepatic steatosis combined with obesity, type 2 diabetes mellitus, or other metabolic dysregulation conditions, all of which significantly elevate the risk of chronic kidney disease (CKD). This review discusses the pathological mechanisms of lipid accumulation and insulin resistance in MAFLD and CKD, highlighting their mechanistic connections. Specifically, ectopic fat accumulation triggered by metabolic reprogramming, oxidative stress and inflammation induced by energy overload, modified lipids, uremic toxins, and senescence, as well as insulin resistance pathways activated by pro-inflammatory factors and lipotoxic products, collectively exacerbate simultaneous hepatic and renal injury. Moreover, interactions among hyperinsulinemia, the sympathetic nervous system, the renin–angiotensin system (RAS), and altered adipokine and hepatokine profiles further amplify insulin resistance, ectopic lipid deposition, and systemic damage. Finally, the review explores potential therapeutic strategies targeting lipid metabolism, insulin sensitivity, and RAS activity, which offer promise for dual-organ protection and improved outcomes in both hepatic and renal systems. 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

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

Background/Objectives: The renin–angiotensin system (RAS) is well-established as a moderator of cardiovascular equilibrium and blood pressure. Nevertheless, growing evidence indicates that angiotensin II (Ang II), the principal RAS effector peptide, together with additional constituents, is involved in various malignancies. Since the immune system is an important aspect in tumor development, this study sought to investigate the role of Ang II in the crosstalk between tumor-associated macrophages (TAMs) and breast cancer cells in the tumor microenvironment (TME). Methods: We treated THP-1-like macrophages with 100 nM Ang II for 24 h. The culture media thus obtained was used as conditioned media and applied at 50% on MCF-7 and MDA-MB-231 breast cancer cell lines. The effects of the conditioned media on cancer cell lines were then investigated by various methods such as a cell proliferation assay, migration assay, polarization assay, and by the detection of apoptosis and reactive oxygen species (ROS) generation. Results: We demonstrated that in vitro Ang II promotes macrophage polarization toward proinflammatory M1-like macrophages and anti-inflammatory M2-like macrophages. Interestingly, Ang II, through macrophages, showed varied effects on different breast cancer cell lines, promoting tumor growth and progression in MCF-7 while inhibiting tumor growth and progression in MDA-MB-23. Conclusions: This study has provided clear evidence that Ang II in the TME modulates TAM polarization and secretions, leading to different effects based on the type of breast cancer. Full article

Hypertension and metabolic dysfunction-associated fatty liver disease (MAFLD) are both common chronic diseases globally. Nearly half of patients with hypertension are complicated by MAFLD. The mechanisms of the bidirectional promotion between the two remain unclear. The (pro) renin receptor ((P)RR) is one of the classic members of the renin–angiotensin system (RAS) and serves as the receptor for prorenin. Although the role of (P)RR in the induction and progression of hypertension has been extensively studied, its role and underlying mechanisms in MAFLD remain underreported. In this study, we aim to investigate the role of (P)RR in the pathogenesis of hypertension combined with MAFLD. In this study, SHRs were used for the model for hypertension combined with MAFLD. Liver lipid content analysis, liver H&E staining, the detection of (P)RR, ERK and downstream proteins related to fatty acid synthesis and transport, and RNA sequencing and data analysis were performed. In the in vitro experiments, we activated (P)RR using renin and established the lipid deposition model of HepG2 cells induced by renin for the first time. (P)RR was specifically blocked using handle region peptide (HRP), and Nile red fluorescence staining, (P)RR/ERK/PPARγ protein expression analysis, and immunofluorescence were performed to further verify the role of (P)RR in the pathogenesis of hypertension combined with MAFLD. Our results demonstrate that (P)RR plays a role in the development and progression of hypertension combined with MAFLD. The hepatic TG and FFA levels in the SHRs were increased, and the protein expression of the (P)RR/ERK/PPARγ pathway and downstream proteins related to fatty acid synthesis and transport were upregulated. HRP reversed the activation of these proteins and reduced intracellular lipid accumulation. In conclusion, our study first reveals that (P)RR is a potential therapeutic target for hypertension combined with MAFLD. And we found the (P)RR/ERK/PPARγ axis for the first time, which plays an important role in the progression of spontaneous hypertension combined with MAFLD. 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