Search Results (1,611)

Endothelial cell (EC) barrier integrity is tightly regulated by the activity of the non-muscle myosin light chain kinase (nmMLCK) under diverse pathological inflammatory conditions (pneumonia, sepsis) and exposure to mechanical stress. Inflammatory stimuli, including lipopolysaccharide (LPS), cytokines, and damage-associated molecular patterns (DAMPs), increase EC permeability through nmMLCK-dependent EC paracellular gap formation. However, the exact mechanisms by which nmMLCK regulates vascular barrier dysfunction in acute lung injury (ALI) remain incompletely understood. We hypothesized that inflammation-induced ROS results in the peroxynitrite-mediated nitration of nmMLCK that contributes to EC barrier disruption. Human lung EC exposure to either the peroxynitrite donor, SIN-1, or to LPS, triggered significant nmMLCK nitration, which was abolished by the oxidant scavenger, MnTMPyP. Mass spectrometry of SIN-1-treated nmMLCK identified multiple nitrated tyrosines. Nitration of Y1410 proved a critical PTM as site-directed substitution with alanine (Y1410A) abolished both SIN-1- and LPS-induced nmMLCK nitration. nmMLCK nitration disrupts wild-type nmMLCK interaction with Kindlin-2, a cytoskeletal regulator of vascular barrier stability, whereas EC transfected with the Y1410A nmMLCK mutant exhibited preserved Kindlin-2 binding, reflected by alterations in trans-EC electrical resistance (TEER). Consistent with these observations, LPS-challenged murine lungs displayed enhanced nmMLCK nitration and diminished nmMLCK-Kindlin-2 association. Functionally, SIN-1 markedly impaired EC barrier integrity (TEER), which was not observed in ECs expressing the Y1410A mutant. Together, these findings suggest that nmMLCK nitration at Y1410 is a critical molecular mechanism contributing to vascular leakage, highlighting this modification as a potential therapeutic target to reduce inflammation-induced vascular permeability. Given nmMLCK’s established role in barrier regulation, we hypothesized that LPS-induced peroxynitrite formation may promote the nitration of nmMLCK tyrosine residues: a PTM that potentially contribute to nmMLCK’s regulation of EC barrier integrity. Full article

Platelets have traditionally been viewed as passive cellular elements involved in hemostasis and vascular integrity. However, growing evidence over the last decade has radically changed this paradigm, revealing platelets as dynamic immune and inflammatory effectors that actively participate in host–pathogen interactions. In viral infections, platelets are not merely innocent bystanders but represent key players in a bidirectional and tightly regulated platelet–virus axis that influences viral dissemination, immune activation, endothelial dysfunction, and the development of thrombotic and hemorrhagic complications. Several clinically relevant viruses, including SARS-CoV-2, influenza virus, HIV, dengue virus, and viral hemorrhagic fever-associated pathogens, have been shown to directly or indirectly interact with platelets through surface receptors, immune complexes, and inflammatory mediators, leading to platelet activation, phenotypic reprogramming, and accelerated clearance. These processes contribute to the paradoxical coexistence of thrombocytopenia and hypercoagulability that characterizes many severe viral diseases. Moreover, platelets can act as immune sentinels by sensing viral components, releasing cytokines and chemokines, forming platelet–leukocyte aggregates, and modulating both innate and adaptive immune responses, thereby shaping the clinical course of infection. In this review, we synthesize current evidence on the molecular and cellular mechanisms governing virus–platelet interactions, with particular emphasis on their role in immune-thrombosis, endothelial injury, and organ dysfunction. We further discuss the clinical implications of platelet dysregulation in viral infections, including its potential value as a biomarker of disease severity and as a therapeutic target. Understanding the platelet–virus axis provides a unifying framework to explain the thrombo-inflammatory phenotype of viral diseases and may open new avenues for risk stratification and targeted interventions in affected patients. Full article

Essential hypertension is a leading cause of chronic kidney disease (CKD) and is frequently complicated by hypertensive nephropathy, characterized by nephroangiosclerosis and increased intrarenal vascular resistance, assessable by renal resistive index (RRI). Oxidative stress and endothelial dysfunction contribute to CKD progression, and the Mediterranean diet (MD) has been associated with a more favorable oxidative and endothelial profile, although data linking diet to renal microcirculation in hypertensive nephropathy remain limited. The aim of this study is to evaluate the relationship between RRI, oxidative stress, endothelial function, and adherence to the Mediterranean diet in patients with essential hypertension and hypertensive nephropathy. We performed a cross-sectional single-center study and we enrolled 99 patients with essential hypertension, hypertensive nephropathy, and CKD stages G1–G4 (KDIGO). All patients underwent laboratory testing, measurement of oxidative stress markers (sNOX2-dp, H₂O₂) and endothelial function (NO), renal ultrasound with interlobar RRI assessment, and PREDIMED questionnaire for MD adherence. A significant direct correlation was observed between RRI and oxidative stress markers (sNOX2-dp and H₂O₂) (p = 0.002, r = 0.302; p = 0.002, r = 0.322), while a significant inverse correlation was found between RRI and the endothelial function marker (NO) (p = 0.013, r = −0.302). The correlation between RRI and PREDIMED questionnaire scores did not reach statistical significance, but there was a trend toward an inverse association (p = 0.06, r = −0.18). In addition, a significant inverse correlation was observed between RRI and eGFR (p = 0.005, r = −0.27), consistent with published data. We also found a significant inverse correlation between sNOX2-dp and PREDIMED scores (p = 0.034, r = −0.21); no statistically significant correlations with H₂O₂ and NO were observed in this analysis. Higher intrarenal vascular resistance is associated with heightened oxidative stress, impaired endothelial function, and lower eGFR. Adherence to the Mediterranean diet is linked to lower NOX2-mediated oxidative stress, supporting a potential association between higher MD adherence and lower NOX2-related oxidative stress. These findings are hypothesis-generating and require confirmation in adequately powered longitudinal and interventional studies before any clinical inference on CKD progression can be made. Full article

Background: Refractory ulcerative colitis (rUC) represents a critical therapeutic challenge, with emerging evidence implicating gut vascular barrier (GVB) dysfunction in disease persistence. We investigated whether dysregulation of the endothelial BMP9-ALK1 signaling axis—a pathway not previously studied in UC—is associated with GVB impairment and treatment resistance, and explored its therapeutic potential. Methods: Serum BMP9 and mucosal ALK1 levels were compared across rUC, non-rUC, and healthy cohorts. The therapeutic efficacy of BMP9 was evaluated in DSS-induced murine colitis by examining vascular permeability, histopathology, and inflammatory markers, while mechanistic roles were investigated using human intestinal microvascular endothelial cells. Results: Serum BMP9 levels were significantly reduced in rUC versus non-rUC patients, inversely correlating with post-treatment disease severity (Modified Mayo Score: r = −0.471, 95% CI: −0.618 to −0.293, p < 0.001; UCEIS: r = −0.495, 95% CI: −0.637 to −0.321, p < 0.001). Stratified analyses confirmed that BMP9 deficiency was associated with treatment-refractory status independent of baseline disease severity. Intestinal ALK1 was downregulated in rUC mucosa. In murine DSS-colitis, BMP9 attenuated disease severity, colon shortening, histopathological damage, inflammatory cytokines, and early pro-fibrotic markers (Col1a1, Col3a1, α-SMA). BMP9 activated SMAD1, restored VE-cadherin, and reduced hyperpermeability (FITC-dextran leakage decreased from 10.2-fold to 2.1-fold, p < 0.001). In vitro, BMP9 inhibited TNF-α-induced neutrophil migration and enhanced endothelial tube stability via ALK1. Conclusions: Dysregulated BMP9-ALK1 signaling may contribute to GVB dysfunction in UC. BMP9 supplementation attenuates vascular leakage and inflammation in experimental colitis, identifying a potential therapeutic target warranting further investigation. Full article

Inflammatory bowel disease (IBD) is associated with an increased risk of venous thromboembolic events (VTEs) and a moderate risk of arterial cardiovascular events. This varies with inflammatory activity and acute-care exposure, with pathophysiological data supporting a thromboinflammatory phenotype in which intestinal inflammation influences systemic vascular homeostasis through innate immune activation, coagulation–platelet crosstalk, endothelial dysfunction, impaired fibrinolysis, and immunothrombosis. Clinically, prevention and management should be integrated into routine care and anchored in sustained, steroid-sparing disease control, combined with guideline-based in-hospital thromboprophylaxis and standard cardiovascular prevention. Decisions regarding anticoagulant therapy after VTEs should follow established principles while recognizing that recurrence prevention depends not only on anticoagulant choice but also on minimizing repeated inflammatory and treatment-related risk exposures. Cardiovascular risk assessment and optimization of modifiable factors should be considered before therapy escalation or treatment switching. Future advances will likely come from more personalized risk assessment across dynamic high-risk windows and from adjunctive, mechanism-informed strategies targeting key nodes of the gut–vascular interface and immunothrombosis. Full article

Insulin resistance (IR) is a central driver of cardiometabolic disease and an increasingly recognized modifier of inflammatory and vascular pathology. Beyond impaired glucose homeostasis, IR emerges from chronic, metabolically induced inflammation (“meta-inflammation”) and convergent cellular stress programs that propagate across tissues and organ systems, ultimately shaping endothelial dysfunction, atherogenesis, and cardiometabolic complications. Here, we synthesize multilevel links between insulin receptor signaling, intracellular stress modules (oxidative, endoplasmic reticulum, inflammatory, and fibrotic pathways), tissue-level dysfunction, and systemic inflammatory amplification. This work is a conceptual narrative review informed by targeted database searches and citation tracking, with explicit separation of mechanistic/experimental evidence from human observational and interventional data; causal inferences are framed primarily on mechanistic and interventional findings, whereas associative statements are reserved for observational evidence. We propose an integrative framework in which stress-response pathways are context-dependent and become maladaptive when chronically activated under nutrient excess and persistent inflammatory cues, generating self-reinforcing loops between IR and inflammation that accelerate vascular injury. This framework highlights points of convergence that can guide mechanistic prioritization and translational hypothesis testing. Full article

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is initiated by the viral spike proteins, which are key structural components that mediate host cell binding and entry and alter downstream signaling through multiple interactions with endothelial surface receptors. Endothelial dysfunction is a central consequence of COVID-19, contributing to vascular inflammation, barrier disruption, thrombosis, and multi-organ injury affecting the pulmonary, cardiovascular, cerebral, and renal systems. Emerging evidence demonstrates that spike protein-mediated effects, independent of productive viral infection, disrupt endothelial homeostasis through angiotensin-converting enzyme 2 (ACE2) dysregulation, integrin engagement, altered calcium signaling, junctional protein remodeling, oxidative stress, and pro-inflammatory and pro-apoptotic pathways. This review is intentionally focused on spike (S) protein-driven mechanisms of endothelial dysfunction; pathogenic vascular effects attributed to other SARS-CoV-2 structural proteins, including the nucleocapsid (N) protein, are beyond the scope of this discussion. In this review, we synthesize current experimental and translational data detailing the molecular mechanisms by which the SARS-CoV-2 spike protein drives endothelial dysfunction across multiple organ systems and discuss potential therapeutic strategies aimed at preserving endothelial integrity in acute COVID-19 and its long-term vascular sequela. Full article

Cardiovascular diseases (CVDs) remain the leading cause of mortality worldwide. CVDs are associated with multiple factors, including oxidative stress, mediated endothelial dysfunction, vascular inflammation, and atherothrombosis. Although traditional antioxidant supplementation (such as vitamins C, E, and β-carotene) has shown promising results in rigorous animal model studies, it has consistently failed to demonstrate clinical benefit in most human trials. Consequently, there is a substantial unmet need for novel paradigms involving mechanistically and biologically relevant pharmaceutical-grade antioxidant therapies (“next-generation antioxidants”). Rapid advancements in redox biology, nanotechnology, genetic modulation of redox processes, and metabolic regulation have enabled the development of new antioxidant therapeutics, including mitochondrial-targeted agents, NADPH oxidase (NOX) inhibitors, selenoprotein and Nrf2 activators, engineered nanoparticles, catalytic antioxidants, and RNA-based and gene-editing strategies. These interventions have the potential to modulate specific oxidative pathways that contribute to CVD pathogenesis. This review provides a comprehensive assessment of current oxidative stress–modulating modalities and their potential to inform personalized cardiovascular prevention and treatment strategies. Full article

Diabetic foot complications represent a major global health burden and arise from a multifactorial interaction between neuropathy, ischemia, infection, and impaired wound repair. Increasing evidence suggests that, beyond traditional vascular and metabolic risk factors, endocrine dysregulation plays a central role in shaping vascular dysfunction and tissue vulnerability in patients with diabetes. This narrative review provides an updated overview of the endocrine–vascular axis in the development, progression, and healing of diabetic foot ulcers (DFUs), integrating evidence from experimental and clinical studies identified through targeted searches of PubMed, Embase, and Scopus. We examine how alterations in insulin signaling, relative glucagon excess, adipokine imbalance, dysregulation of stress hormones, and thyroid dysfunction interact with chronic hyperglycemia, dyslipidemia, mitochondrial dysfunction, and low-grade inflammation to impair endothelial homeostasis. These disturbances promote oxidative stress, reduce nitric oxide bioavailability, and compromise microvascular perfusion, thereby creating a pro-ischemic and pro-inflammatory tissue environment that limits angiogenesis, extracellular matrix (ECM) remodeling, immune coordination, and effective wound repair. By linking pathophysiological mechanisms to clinical relevance, this review highlights potential biomarkers of endocrine–vascular dysfunction, implications for risk stratification, and emerging therapeutic perspectives targeting metabolic optimization, endothelial protection, and hormonal modulation. Finally, key knowledge gaps and priority areas for future translational and clinical research are discussed, supporting the development of integrated endocrine-based strategies aimed at improving DFU prevention, healing outcomes, and long-term limb preservation in patients with diabetes. Full article

Cardiovascular disease (CVD) is increasingly recognized as a significant comorbidity in people living with HIV (PWH), contributing to increased morbidity and mortality. Epidemiological studies indicate that PWH have a 1.2–2-fold higher risk of myocardial infarction (MI) and other CVD events compared to HIV-negative individuals. While the mechanisms underlying HIV-associated CVD are not fully understood, they are likely to include a combination of cardiovascular-related adverse effects of HIV medications, vascular dysfunction caused by HIV-induced monocyte activation, and cytokine secretion, in addition to existing comorbidities and lifestyle choices. This comprehensive review examines the complex relationship between HIV infection and CVD, highlighting key pathophysiological mechanisms such as chronic immune activation, inflammation, endothelial dysfunction, and the role of antiretroviral therapy (ART) in promoting cardiovascular risk. Alongside conventional risk factors such as smoking, hypertension, and dyslipidemia, HIV-specific elements, especially metabolic abnormalities associated with ART, significantly contribute to the development of CVD. Prevention strategies are crucial, focusing on the early identification and management of cardiovascular risk factors as well as optimizing ART regimens to minimize adverse metabolic effects. Clinical guidelines now recommend routine cardiovascular risk assessment in PWH, emphasizing aggressive management tailored to their unique health profiles. However, challenges exist in fully understanding the cardiovascular outcomes in this population. Future research directions include exploring the role of inflammation-modulating therapies and refining sustainable prevention strategies to mitigate the growing burden of CVD in PWH. Full article

Background/Objectives: Cerebral angiography is a cornerstone diagnostic and therapeutic procedure for cerebrovascular diseases; however, its potential effects on vascular integrity and cellular homeostasis remain incompletely elucidated. This systematic review aims to comprehensively evaluate endothelial and histopathological alterations induced by cerebral angiographic procedures, with particular emphasis on oxidative stress, inflammation, endothelial dysfunction, and blood–brain barrier disruption. Methods: This systematic review was conducted in accordance with the PRISMA 2020 guidelines. PubMed, Scopus, and Web of Science databases were systematically searched for studies published between 1981 and 2025 using predefined keywords related to cerebral angiography, endothelial injury, oxidative stress, inflammation, and histopathological changes. A total of 1142 records were identified, and 216 duplicates were removed. Following title and abstract screening, 312 full-text articles were assessed for eligibility, of which 112 were excluded due to irrelevance or insufficient endothelial or histopathological data. Ultimately, 200 studies were included in the qualitative synthesis. The literature identification, screening, and selection process are summarized in the manuscript. The review protocol was not prospectively registered. Results: The included studies demonstrated that cerebral angiographic procedures induce endothelial and microvascular alterations through both mechanical and contrast-mediated mechanisms. Iodinated contrast agents were consistently associated with increased reactive oxygen species production, reduced endothelial nitric oxide bioavailability, mitochondrial dysfunction, and activation of pro-inflammatory signaling pathways, including nuclear factor kappa B (NF-κB). Histopathological findings revealed endothelial swelling, vacuolization, apoptosis, microthrombus formation, inflammatory cell infiltration, and disruption of endothelial junctions, leading to increased vascular permeability and blood–brain barrier impairment. Mechanical factors related to catheter manipulation and high-pressure contrast injection further exacerbated endothelial injury by altering shear stress and promoting leukocyte adhesion. The severity of endothelial damage and inflammatory responses was consistently greater in patients with comorbid conditions such as diabetes mellitus, hypertension, and atherosclerotic disease. Conclusions: Cerebral angiography may induce endothelial dysfunction and histopathological vascular injury predominantly through oxidative and inflammatory mechanisms. Optimization of contrast agent selection, refinement of procedural techniques, and implementation of endothelial-protective strategies may mitigate vascular injury and improve procedural safety. Further translational and clinical studies are warranted to identify biomarkers and protective interventions targeting angiography-induced endothelial damage. Full article

Introduction: Gestational hypoxia (GH) increases the risk of cardiovascular diseases by inducing oxidative stress and vascular dysfunction. This study investigates whether prenatal melatonin can mitigate these effects in guinea pigs. Methods: Pregnant guinea pigs were exposed to normoxia or hypoxia and treated with melatonin (1 mg/kg/day). Echocardiography, vascular reactivity, and molecular assays were used to assess cardiovascular structure, function, and redox balance in neonates. Results: GH reduced neonatal birth weight and altered left ventricular (LV) development, resulting in increased LV systolic function and aortic blood flow velocity. Melatonin treatment reversed these effects, restoring endothelial-dependent vasodilation and decreasing oxidative stress in the LV and thoracic aorta. Catalase antioxidant enzyme activity was elevated in melatonin-treated hypoxic neonates. Unexpectedly, melatonin treatment altered cardiac structure in normoxic pregnancies, increasing LV length and decreasing LV myocardial nuclei density. Conclusions: Prenatal melatonin partially modulates GH-induced endothelial dysfunction and oxidative stress, offering potential therapeutic value. However, its effects under normoxic conditions deserve caution, emphasizing the need for targeted use only in pregnancies with evident hypoxic and oxidative stress conditions. Full article

Background and Objectives: Patients with type 2 diabetes mellitus (T2DM) and ischemic stroke present with endothelial, vascular and left ventricular (LV) myocardial dysfunction. We investigated the effects of treatment with either glucagon-like peptide-1 receptor agonists (GLP-1RA) or sodium-glucose contrasporter-2 inhibitors (SGLT-2i) on endothelial glycocalyx, arterial stiffness, and LV myocardial strain in patients with metformin-treated T2DM and a prior ischemic stroke. Materials and Methods: A total of 54 consecutive patients with T2DM and ischemic stroke who attended a cardiometabolic outpatient clinic in Athens, Greece, and received either GLP-1RA (dulaglutide; n = 27) or SGLT-2i (empagliflozin; n = 27) were enrolled in the study. We measured the perfused boundary region (PBR) of the sublingual microvessels, a marker of glycocalyx thickness, as well as carotid-femoral pulse wave velocity (PWV) and LV global longitudinal strain (GLS), at baseline and at 4 and 12 months of treatment. Results: Twelve months after treatment, all patients had reduced glycosylated hemoglobin and body mass index (BMI) (p < 0.001). Patients treated with dulaglutide showed a greater reduction in BMI (−11.8% vs. −4.8%, p < 0.001) compared to those treated with empagliflozin. Compared to baseline, all patients had reduced PBR, PWV and GLS (p < 0.001) after 12 months of treatment. However, empagliflozin presented a greater decrease in PWV (−14% vs. −10.9%, p = 0.041), while dulaglutide resulted in a greater increase in GLS (14.7% vs. 8.3%, p = 0.024) compared to empagliflozin. In all patients, the reduction in PBR at 12 months was correlated with a decrease in PWV and with an increase in GLS (p < 0.05). Conclusions: Both dulaglutide and empagliflozin improve cardiovascular function in T2DM patients with ischemic stroke. Dulaglutide appears to be more effective in the improvement of LV myocardial strain, whereas empagliflozin is more effective in reducing arterial stiffness. Full article

Oxidative stress (OS) resulting from an imbalance between reactive oxygen species (ROS) generation and antioxidant defenses plays a pivotal role in vascular diseases such as atherosclerosis and hypertension. ROS derived from NADPH oxidase, mitochondria, and xanthine oxidase promote endothelial dysfunction by inducing lipid and protein oxidation, apoptosis, and pro-inflammatory signaling, thereby enhancing smooth muscle proliferation and atherogenesis. This review summarizes the molecular mechanisms linking OS to vascular injury and aims to systematically elucidate the role of OS in vascular diseases, with a specific focus on critiquing the current challenges in translating biomarkers to clinical practice and the emerging trends in personalized antioxidant therapy. Particular attention is given to biomarkers of oxidative stress, including those assessing antioxidant enzyme activity and oxidative damage products, which possess potential for clinical use. Therapeutic strategies targeting OS, including dietary and pharmacological antioxidants, show promise in improving vascular health, although clinical outcomes have been inconsistent and it is necessary to resolve the standardization and validation of these biomarkers, develop precise targeted therapies against specific ROS sources (e.g., NOX inhibitors, mitochondrial antioxidants), and explore personalized clinical trials based on redox stratification. Overall, OS is a central mediator in vascular pathology, and progress in biomarker validation and targeted therapies will be essential to translate current knowledge into effective prevention, diagnosis, and treatment of cardiovascular diseases. Personalized approaches based on accurate redox profiling may enhance efficacy. Full article

Cardiovascular diseases (CVDs) remain the leading cause of death worldwide, with growing evidence indicating that epigenetic mechanisms play a central role in their onset and progression. This review provides a comprehensive overview of current knowledge on the epigenetic regulation and molecular mechanisms involved in CVDs, as well as their potential therapeutic implications. The findings demonstrate that DNA methylation, histone modifications, and non-coding RNAs are key regulators of gene expression associated with cardiac hypertrophy, atherosclerosis, myocardial infarction, and heart failure. Interactions between epigenetic alterations and inflammatory or oxidative stress pathways further contribute to endothelial dysfunction and vascular remodeling. Emerging therapeutic strategies targeting these mechanisms, including histone deacetylase inhibitors, DNA methyltransferase inhibitors, and RNA-based therapeutics, show promising cardioprotective effects in experimental and early clinical studies. Overall, this review underscores the significance of epigenetic regulation in cardiovascular pathophysiology and highlights the potential of epigenetic-based interventions as a foundation for precision medicine and novel therapeutic approaches in cardiology. Full article