Search Results (1,968)

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

Intravenous thrombolysis with recombinant tissue-type plasminogen activator (tPA) remains a keystone of acute ischemic stroke treatment but in a subset of patients is complicated by angioedema, a potentially life-threatening adverse event largely mediated by bradykinin signaling. The unpredictable and idiosyncratic nature of this reaction has long suggested an underlying genetic contribution, yet its molecular architecture has remained poorly characterized. We hypothesized that alteplase-associated angioedema represents a multigenic susceptibility phenotype, arising from the convergence of rare genetic variants across multiple interacting physiological systems rather than from a single causal variant. To explore this hypothesis, we performed clinical exome sequencing in a cohort of 11 patients who developed angioedema following alteplase administration. Rather than identifying a shared pathogenic variant, we observed distinct yet convergent patterns of genetic vulnerability, allowing patients to be grouped according to dominant, but overlapping, biological axes. These included alterations affecting bradykinin regulation (e.g., ACE, SERPING1, XPNPEP2), endothelial structure and hemostasis (e.g., VWF, COL4A1), neurovascular and calcium signaling (e.g., SCN10A, RYR1), and vascular repair or remodeling pathways (e.g., PSEN2, BRCA2). Notably, many of the identified variants were classified as Variant of Uncertain Significance (VUS) or likely benign significance in isolation. However, when considered within an integrated, pathway-based framework, these variants can be interpreted as capable of contributing cumulatively to system level fragility, a phenomenon best described as “contextual pathogenicity”. Under the acute biochemical and proteolytic stress imposed by thrombolysis, this reduced physiological reserve may allow otherwise compensated vulnerabilities to become clinically manifest. Together, these findings support a model in which severe alteplase-associated angioedema appears as an emergent property of interacting genetic networks, rather than a monogenic disorder. This systems level perspective underscores the limitations of gene centric interpretation for adverse drug reactions and highlights the potential value of pathway informed, multi-genic approaches to risk stratification. Such frameworks may ultimately contribute to safer, more personalized thrombolytic decision, while providing a conceptual foundation for future functional and translational studies. 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

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

As the brain’s resident macrophages, microglia on the one side are increasingly recognized as essential players in discrete developmental stages, where immune, metabolic, and activity-derived signals are coordinately integrated to guide brain development. On the other side, the precise temporal and molecular coordination of microglial maturation is imperative for the structural and functional integrity of the developing central nervous system (CNS). In this review, we synthesize recent data that reposition microglia from a uniform population of immune sentinels to temporally programmed and regionally specialized regulators of circuit maturation. This involves dissecting the embryonic origins and migratory pathways of microglial progenitors in mouse and human systems and illustrating how gradual transcriptional and morphological maturation aligns the biology of microglia with progressive phases of neurogenesis, synaptic fine-tuning, myelination, and vascular stabilization. In addition, we discuss how individual gene mutations, inflammatory insults during perinatal life, and environmental disturbances intersect with these temporal programs to alter microglial phenotypes and compromise circuit formation. With a special emphasis on epilepsy and autism spectrum disorder, often sharing the common etiology, we illustrate how early malfunction of microglia may drive neural network dysfunction. Full article

Juvenile idiopathic arthritis (JIA) is the most prevalent chronic rheumatologic condition in childhood, with an incidence that continues to rise worldwide. Despite substantial progress in therapeutic strategies over the past two decades, JIA remains a major health concern. Beyond joint inflammation and musculoskeletal impairment, accumulating evidence indicates that JIA is associated with metabolic disturbances and altered body composition, which may predispose affected children to an elevated cardiovascular risk in the long term. The objective of this review is to synthesize current knowledge on these metabolic and anthropometric alterations and to evaluate the role of non-invasive diagnostic methods in detecting early cardiovascular changes. A narrative review of the literature was conducted using PubMed and Scopus databases, focusing on studies assessing lipid metabolism, insulin resistance, adiposity, and cardiovascular markers in pediatric patients with JIA. Special attention was given to non-invasive diagnostic approaches, including bioelectrical impedance analysis (BIA), dual-energy X-ray absorptiometry (DXA), skinfold thickness, transient elastography, carotid intima–media thickness (cIMT), as well as selected biochemical markers. Evidence suggests that children with JIA frequently present with dyslipidemia, increased insulin resistance, and abnormal body fat distribution compared with their healthy peers. Non-invasive assessment methods, particularly DXA and cIMT, have demonstrated sensitivity in detecting subclinical metabolic and vascular changes. These alterations resemble early features of metabolic syndrome and are thought to contribute to premature cardiovascular morbidity in this population. Incorporating non-invasive cardiovascular risk assessment into routine rheumatology practice may improve early detection of metabolic and vascular complications in JIA, support timely preventive interventions, and ultimately enhance long-term outcomes for affected children. Most available evidence is derived from cross-sectional studies, highlighting the need for longitudinal investigations to better define long-term cardiometabolic risk in JIA. Full article

Abdominal aortic aneurysm (AAA) is a lethal vascular disease characterized by intramural hemorrhage. This study delineates the signatures of heme and its metabolic imbalance related to progression and inflammation in AAA. Clinical analyses of patients undergoing open AAA surgery show that AAA patients exhibit vascular inflammation, with elevated serum CRP, IL-6, and heme levels correlating with the expression of heme-regulated gene Hmox1/HO-1 (heme oxygenase-1) in the affected aortic wall. Oxidation of hemoglobin to ferri state leading to accumulation of methemoglobin readily releasing heme occurs in human AAA and in angiotensin II (AngII)-induced AAA in apolipoprotein E-deficient mice. Transcriptomic analysis for AngII-induced AAA identifies upregulated genes predominantly enriched in inflammatory signaling, extracellular matrix degradation, oxidative stress pathways, and altered expression of genes related to heme metabolism including Hmox1. Immunohistochemistry for IL1β and TNFα confirms inflammatory activation within AAA tissues. The signatures of heme-responsive gene inductions, enhanced expression of HO-1 and H-ferritin, are detected. Mechanistic studies employing endothelial cells and smooth muscle cells reveal that heme exposure of resident cells markedly enhances the expression of IL1β and ICAM1, as well as the inflammasome component NLRP3, and such inflammatory response is controlled by HO-1. Intervention with Normosang (heme arginate), an HO-1 inducer, attenuates aneurysm progression, whereas HO-1 inhibition by Tin protoporphyrin IX abolishes this protection. Induction of HO-1 accompanied by elevated H-ferritin level also mitigated aortic wall inflammation as reflected by lowering IL1β and TNFα. These findings highlight the heme-HO-1-H-ferritin axis as an element of AAA pathogenesis and a potential therapeutic target. Full article

Premelanosomal protein (Pmel, also known as Pmel17) is the major component of melanosomal fibrils and plays a key role in melanin polymerization, making it an important factor in melanogenesis. We investigated how the absence of Pmel affects the properties of B16F10 melanoma cells. Pmel-knockout B16F10 cells were generated using CRISPR/Cas9-mediated genome editing. A viability assay revealed no significant differences between wild-type (WT) and Pmel-knockout (KO) sublines; however, melanosome maturation was impaired. In Pmel KO cells, the cell cycle was disrupted, and higher levels of reactive oxygen species (ROS) were observed compared with WT cells. Moreover, the migration capacity and tube formation of melanoma cells were increased. Tumors derived from Pmel KO cells exhibited unchanged growth kinetics but reduced melanin content, along with enhanced vascularization and oxygenation. Thus, knockout of the Pmel17 gene in melanoma cells alters pigmentation, vascularization, and oxygenation of tumors. These parameters are crucial for both tumor progression and therapeutic response. Full article

Vascular smooth muscle cells (VSMCs) in the tunica media are essential for maintaining the structure and function of the arterial wall. These cells regulate vascular tone and contribute to vasculogenesis and angiogenesis, particularly during development. Proper control of VSMC differentiation ensures the correct size and patterning of vessels. Dysregulation of VSMC behaviour in adulthood, however, is linked to serious cardiovascular diseases, including aortic aneurysm, coronary artery disease, atherosclerosis and pulmonary hypertension. VSMCs are characterised by their phenotypic plasticity, which is the capacity to transition from a contractile to a synthetic, dedifferentiated state in response to environmental cues. This phenotypic switch plays a central role in vascular remodelling, a process that drives the progression of many vascular pathologies. Epigenetic mechanisms, which are defined as heritable but reversible changes in gene expression that do not involve alterations to the DNA sequence, have emerged as key regulators of VSMC identity and behaviour. These mechanisms include DNA methylation, histone modifications, chromatin remodelling, non-coding RNA and RNA modifications. Understanding how these epigenetic processes influence VSMC plasticity is crucial to uncovering the molecular basis of vascular development and disease. This review explores the current understanding of VSMC biology, focusing on epigenetic regulation in health and pathology. Full article

During the COVID-19 pandemic, SARS-CoV-2 quickly spread all over the world in a pattern of waves. In Mexico, the first wave was from March 2020 to September 2020, and during this time autopsies were forbidden. After that, the postmortem lung samples allowed us to identify histological alterations because of COVID-19. Moreover, SARS-CoV-2 infections are characterized by the manifestation of cytopathic effects like inclusion bodies, and multinucleated cells in alveolar spaces and alveolar walls. Additionally, atypical, enlarged cells, presence of macrophages in alveolar spaces, and congestion of vascular vessels were the other histopathologic alterations of the lung. Our study covered the analysis of nine postmortem lung samples from patients with severe COVID-19 diagnosed by qRT-PCR. The samples were stained with Hematoxylin-Eosin to identify the histological alterations related to lung architecture and cell populations and were subjected to immunohistochemistry for the SARS-CoV-2 Spike and Nucleocapsid proteins. All samples showed alterations associated with diffuse alveolar damage and 1/9 presented no alveolar space, 5/9 presented different levels of pleural fibrosis, and 4/9 presented distention of the small capillaries. Immunohistochemistry results revealed that 4/9 samples showed Spike-positive cytoplasmic inclusion bodies in type I pneumocytes and 2/9 Spike-positive nuclear inclusion bodies in type I pneumocytes. These inclusion bodies were found to be eosinophilic with H&E stains. The H&E results suggest tissue alterations that may contribute to the signs and symptoms of severe COVID-19, as well as the Spike protein expression, as its distribution suggests its participation in pathophysiology. Full article

Background/Objectives: The global prevalence and incidence of inflammatory bowel diseases have risen in the past two decades. Among them, Crohn’s disease and ulcerative colitis are still challenging to treat due to vascular and proliferative alterations. Studies in rats suggest that blocking histamine receptors (H1–H4) can improve colitis progression. However, the specific histamine receptor responsible for this effect remains debated. The experiment aimed to assess the role of specific histamine receptor subtypes in colitis development, focusing on oxidative stress markers in the liver and skeletal muscle. Methods: The study involved 60 adult male Wistar rats, divided into control and colitis experimental groups. Colitis was induced through intracolonic administration of 2,4,6-trinitrobenzenesulfonic acid. Animals in both experimental groups received intramuscular injections of NaCl (non-treated, NT) or H1, H2, H3, and H4 receptor antagonists (10 study subgroups in total). On day eight, the animals were re-anesthetized and euthanized via exsanguination. Then, liver and skeletal muscle (m. soleus) samples were collected for analysis of oxidative stress markers. Results: The analyses of skeletal muscle samples showed that using the H1 and H2 receptor antagonists increased superoxide dismutase (SOD) and catalase (CAT) activities, as well as parameters related to glutathione metabolism (reduced glutathione (GSH), glutathione S-transferase (GST)) in rats from the control groups, indicating enhanced antioxidant defense. In rats with chemically induced colitis, we observed that H1 receptor antagonists elevated CAT activity, whereas β-esterase (β-EST) activity remained elevated across all colitis subgroups. In the liver, histamine receptor antagonists produced receptor-specific redox effects: the H2 receptor antagonist reduced oxidative damage (malondialdehyde (MDA)); the H1 receptor antagonist attenuated SOD hyperactivity, but depleted GSH; and the H4 receptor antagonist increased GSH while elevating MDA. Chemically induced colitis increased α- and β-EST activities, whereas administration of the H1 or H3 antagonist reduced β-EST levels. Conclusions: Histamine receptor antagonists modulated oxidative stress responses in both liver and skeletal muscle tissues in a receptor-dependent manner. Among them, the H2 receptor antagonist most effectively mitigated hepatic oxidative injury, highlighting its potential as a therapeutic target in colitis-associated systemic oxidative stress. Full article

The close connections between the intestine and distal systems, known as axes, are a growing focus of scientific research; however, the gut–vascular axis, particularly as a target of microbial metabolites, remains underexplored. In this study, three supernatants derived from probiotic formulations composed of Lactobacillus and Bifidobacterium strains (MIX-1, MIX-2, and MIX-3) were evaluated in counteracting vascular alterations associated with dysbiosis. Human aortic smooth muscle (HASMCs) and endothelial (HAECs) cells were exposed to pro-oxidative (H₂O₂) and pro-inflammatory (TMAO) stimuli. Concentrations up to 5–10% (v/v) were tolerated in both cell lines, with MIX-1 and MIX-3 showing the greatest protective efficacy. These formulations exerted antioxidant effects by reducing H₂O₂-induced ROS production and cell viability loss, and anti-inflammatory effects by limiting TMAO-induced IL-1β release. MIX-1 also attenuated TMAO-induced IL-6 release. Further analyses indicated a partial involvement of the SIRT1-pathway in its vascular antioxidant effects. Chromatographic profiling revealed comparable qualitative metabolites among the probiotic supernatants, while quantitative differences were observed, with higher lactate levels in MIX-1 and MIX-3 compared to MIX-2. Finally, we have determined that Limosilactobacillus reuteri-PBS072 is mainly responsible for the antioxidant effect of MIX-1 and MIX-3. Overall, these findings highlight the potential of probiotic-derived metabolites in modulating the gut–vascular axis and promoting vascular protection. Full article

Background/Objectives: Cardiovascular (CV) and cerebrovascular diseases, primarily attributed to atherosclerosis, stand as leading global causes of morbidity and mortality. This study aims to evaluate the impact of preclinical atherosclerosis parameters, including intima-media thickness (IMT) and arterial stiffness, in a seven-year follow-up of 100 patients with CV risk factors but no known history of CV or cerebrovascular diseases. Methods: Between April 2014 and December 2015, 100 patients presenting with suspected ischemic heart disease were enrolled. The study integrates the color Doppler examination of the supra-aortic trunks with the evaluation of preclinical parameters of atherosclerosis, such as intima-media thickness (IMT), βeta index, and pulse wave velocity (PWV), as well as echocardiographic evaluations, including global longitudinal strain (GLS). CV risk factors, metabolic syndrome, and insulin resistance were assessed and measured for each patient using the Homeostasis Model Assessment of Insulin Resistance (HOMA-IR). Two- and seven-year follow-ups assessed various CV events. Results: The study population comprised 67% males and 33% females. Metabolic syndrome, impaired fasting glycemia and hypertension were prevalent. The mean value of IMT was 1.21 ± 0.26 mm, and PWV was 8.47 ± 2.14 m/s. The 7-year follow-up identified IMT, PWV, and HOMA-IR as strong positive predictors of cardiovascular events, with PWV emerging as a particularly sensitive indicator of early events. Conclusions: Insulin resistance and cardiovascular risk factors may contribute to early alterations in myocardial and vascular function, even in the absence of overt disease. PWV, as a recognized surrogate marker of arterial stiffness, may serve as a sensitive tool for the early prediction of cardiovascular events. A comprehensive screening, including the assessment of markers indicating subclinical vascular alterations, along with the implementation of preventive interventions, is crucial for populations at risk. 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