Search Results (2,143)

Oxidative stress occurs within bovine when exposed to harmful stimuli, accompanied by substantial accumulation of reactive oxygen species. Without timely clearance, these reactive oxygen species attack vascular endothelial cells, concurrently inducing extensive production of lipid peroxides within the vascular endothelium, and thereby triggering ferroptosis. Aspirin eugenol ester (AEE) showed pharmacological activity against oxidative stress-induced vascular endothelial damage. However, whether it could alleviate vascular endothelial damage by inhibiting ferroptosis remains unclear. This study aimed to evaluate the effects of AEE on vascular endothelial ferroptosis and elucidate its underlying molecular mechanisms. This study established vascular endothelial damage models in vitro and in vivo to explore the ability of AEE to inhibit ferroptosis and oxidative stress by measuring ferroptosis- and oxidative stress-related biomarkers. Transcriptomic and network pharmacology analyses were performed to identify AEE-regulated pathways and key targets. Validation of the pathways were conducted using molecular docking, cellular thermal shift assay, and specific protein agonists/inhibitors. AEE inhibited oxidative stress and ferroptosis in bovine aortic endothelial cells induced by hydrogen peroxide (H₂O₂) or RSL3 via suppressing the upregulation of ferroptosis-related genes and enhancing the expression of antioxidant genes. Transcriptomic and network pharmacology analyses identified JNK as a core target of AEE in regulating ferroptosis. JNK agonists enhanced H₂O₂-induced ferritinophagy; on the contrary, JNK inhibitors alleviated it. AEE suppressed H₂O₂-induced phosphorylation of JNK/c-Jun and ferritinophagy. In a carrageenan-induced rat aortic vascular endothelial damage model, AEE alleviated vascular endothelial damage and ferroptosis-related gene changes, promoted antioxidant gene expression, and inhibited JNK/c-Jun phosphorylation and ferritinophagy. AEE inhibited vascular endothelial ferroptosis by enhancing antioxidant ability, blocking downstream ferritinophagy, and reducing ferrous ion release. Full article

Background: Type 2 diabetes mellitus (DM) is a major cardiovascular risk factor that induces monocyte dysfunction and contributes to their accumulation in atherosclerotic lesions. Monocyte recruitment and accumulation in the tissues contribute to chronic inflammation and are essential to the pathobiology of diabetes-induced atherosclerosis. However, the mechanisms that drive the accumulation of monocytes in the diabetic environment are not clearly understood. Methods: Primary monocytes from type 2 (T2) DM and non-T2DM individuals were isolated using magnet-assisted cell sorting. To examine the influence of a diabetic milieu on monocyte function, monocytes from T2DM patients, db/db mice, or human monocytes subjected to hyperglycaemia were analysed for their responses to pro-atherogenic cytokines using Boyden chamber assays. Furthermore, the interactions of non-diabetic and diabetic monocytes with TNFα-inflamed endothelium were studied using live-cell imaging under physiological flow conditions. RT-qPCR and FACS were used to study the expression of relevant molecules involved in monocyte-endothelium interaction. Results: CD14⁺CD16⁻ monocytes isolated from T2DM patients or monocytes exposed to hyperglycaemic conditions showed reduced chemotactic responses towards atherosclerosis-promoting cytokines, CCL2 and CX3CL1, indicating monocyte dysfunction. Under flow conditions, the transendothelial migration (TEM) capacity of T2DM monocytes was significantly reduced. Even though these monocytes adhered to the endothelial monolayer, only a few transmigrated. Interestingly, the T2DM monocytes and monocytes exposed to hyperglycaemic conditions accumulated in the ablumen following transendothelial migration. The time period in the ablumen of T2DM cells was prolonged, as there was a significant impairment of the reverse transendothelial migration (rTEM). Mechanistically, the T2DM milieu specifically induced the activation of monocyte integrins, Macrophage-1 antigen (Mac-1; integrin αMβ2 consisting of CD11b and CD18), and Lymphocyte function-associated antigen 1 (LFA-1; αLβ2 consisting of CD11a and CD18). Furthermore, elevated levels of CD18 transcripts were detected in T2DM monocytes. Junctional Adhesion Molecule 3 (JAM-3)–MAC-1 interactions are known to impede rTEM and T2DM milieu-potentiated JAM-3 expression in human coronary artery endothelial cells (HCAEC). Finally, the overexpression of JAM-3 on HCAEC was sufficient to completely recapitulate the impaired rTEM phenotype. Conclusions: Our results revealed for the first time that the enhanced T2DM monocyte accumulation in the ablumen is not secondary to the elevated transmigration through the endothelium. Instead, the accumulation of monocytes is due to the direct consequence of a dysfunctional rTEM, potentially due to enhanced JAM3-MAC1 engagement. Our results highlight the importance of restoring the rTEM capacity of monocytes to reduce monocyte accumulation-dependent inflammation induction and atherogenesis in the T2DM environment. Full article

Background/Objectives: Enhancing endothelial nitric oxide (NO) bioavailability through natural products may provide a promising strategy for the prevention and management of hypertension. This study investigated the phytochemical composition of ethanolic lotus (Nelumbo nucifera) seed extract (LSE), its vasorelaxant mechanisms, effects on endothelial NO production, and antihypertensive activity. Methods: LSE was characterized via LC-ESI-QTOF-MS using accurate mass data and fragmentation patterns. Vasorelaxant effects were evaluated in isolated rat aortas, and the underlying mechanisms were explored using pharmacological inhibitors. NO production was assessed in human endothelial EA.hy926 cells. Hypotensive activity was examined in normotensive rats following intravenous administration of LSE (10, 30, and 100 mg/kg). Molecular docking was performed to analyze interactions between LSE bioactive compounds and endothelial nitric oxide synthase (eNOS). Results: LC-ESI-QTOF-MS analysis identified 114 compounds, including primary and secondary metabolites. LSE induced vasorelaxation in endothelium-intact aortas, which was reduced by endothelium removal (p < 0.001) and by L-NAME (p < 0.001). LSE also inhibited receptor-operated, Ca²⁺ channel-mediated vasoconstriction (p < 0.05). In vivo, LSE decreased blood pressure in a dose-dependent manner. In EA.hy926 cells, LSE (750 and 1000 µg/mL) increased NO production, an effect attenuated by L-NAME. Molecular docking showed that LSE alkaloids, including nelumborine, nelumboferine, neferine, and isoliensinine had strong affinities for binding with eNOS at the tetrahydrobiopterin (BH4) binding site. Nelumborine exhibited the highest affinity, suggesting its potential as an eNOS modulator. Conclusions: LSE promotes vasorelaxation through the stimulation of endothelium-derived NO release and Ca²⁺ influx inhibition, contributing to blood pressure reduction. These findings support LSE as a potential natural antihypertensive supplement. Full article

We investigated the repeatability of the MS-39 in determining power vector components—the spherical equivalent (SEQ) and astigmatic powers (C0 and C45) and asphericity (Q)—of corneal epithelium, stroma, and endothelium in a large patient cohort. In this retrospective cross-sectional single-centre study, we evaluated a dataset containing 600 MS-39 anterior segment tomography measurements from 200 eyes (three repeat measurements each) taken prior to cataract surgery. The exported measurements included height map data for the epithelium, stroma, and endothelium surface. Model surfaces (spherocylinder (SphCyl), cylindrical conoid (CylConoid), and biconic (Biconic), all in the 3/6 mm zone) were fitted using nonlinear iterative optimisation, minimising the height difference between the measurement and model. The mean (MEAN) and standard deviation (SD) for each sequence of measurements were derived and analysed. In the 3 mm and 6 mm zone, the MEAN SEQ was 53.47/53.56/53.57 and 53.21/53.54/53.54 D for SphCyl/CylConoid/Biconic for the epithelium, −4.47/−4.51/−4.51 and −4.45/−4.50/−4.50 D for the stroma, and −6.23/−6.26/−6.26 and −6.18/−6.29/−6.30 D for the endothelium. With the three surface models and the 3/6 mm zone, the SD for SEQ/C0/C45 was in the range of 0.04 to 0.11/0.05 to 0.13/0.04 to 0.11 D for epithelium; 0.01 to 0.02/0.01 to 0.05/0.01 to 0.06 D for stroma; and 0.01 to 0.02/0.02 to 0.07/0.03 to 0.07 D for endothelium. Fitting floating model surfaces with astigmatism to map data of the corneal epithelium, stroma, and endothelium seems to be a robust and reliable method for extracting equivalent power and astigmatism using all the datapoints within a region of interest. Full article

Atherosclerotic cardiovascular disease treatment is being reevaluated, since a residual cardiovascular risk (RCR) persists even in patients who achieve optimal LDL-C values. Underlying causes are metabolic dysfunction, lipoprotein(a), inflammation, and triglyceride-rich lipoproteins and their remnants. Dietary treatment options like time-restricted eating (TRE) are becoming more widely acknowledged for their potential advantages in metabolic health and weight control, as a treatment of atherosclerosis expanding beyond LDL-C medication. Beyond weight loss, TRE (which restricts meals to a window of 6 to 8 h) appears as the most accessible treatment, and has been shown to improve blood pressure, lipid profiles, and glucose regulation through mechanisms like metabolic switching and circadian synchronization. We hypothesize, and will present our arguments, that a key mechanism underlying the cardiovascular and weight-related benefits of TRE is its impact on the circadian regulation of angiopoietin-like protein 4 (ANGPTL4) activity within adipose tissue. Additionally, lipolysis is accelerated by ANGPTL4 activation. TRE, via its actions on ANGPTL4, therefore not only inhibits adipose fatty acid uptake but stimulates their release as well. Additionally, TRE may increase intravascular very low-density lipoprotein (VLDL) catabolism by muscle due to the reduced exposure of lipoprotein lipase (LPL) to competing chylomicrons, known to slow the rate of VLDL catabolism. During the prolonged fasting, VLDL residence time is thus shortened, limiting the exposure to endothelium and hepatic lipases and thus reducing the amount of atherogenic remnant particles. Larger, longer-term randomized controlled studies in a variety of groups are required to further clarify TRE’s function in RCR prevention and therapy. As knowledge of triglyceride lipoprotein (TRL) metabolism expands, a comprehensive strategy for the management of RCR emerges, and a broader spectrum of LPL regulator-based therapeutics is created. Consequently, it is advisable to prioritize further research into the influence of TRE on LPL modulation via ANGPTL4 and ANGPTL8, which provides a natural, accessible, and low-cost alternative. Full article

Pulmonary arterial hypertension (PAH) is a rare condition characterized by high pulmonary artery pressure leading to right ventricular dysfunction and potential life-threatening consequences. It primarily affects the pre-capillary pulmonary vascular system. The exact pathophysiological mechanisms underlying PAH are not entirely known. Environmental factors; genetic predisposition; mitochondrial and microRNA dysfunction; and inflammatory, metabolic, and hormonal mechanisms may be involved. A central role is played by the dysfunction of the pulmonary vascular endothelium. This alteration is characterized by a reduction in vasodilatory and antiproliferative factors such as prostacyclin and nitric oxide and an increase in vasoconstrictive and mitogenic substances such as endothelin and thromboxane A2. Such imbalance leads to a progressive increase in pulmonary vascular resistance. The aim of the present review is to focus on the vascular endothelium and its role as a potential therapeutic target in PAH. Full article

The vascular 5-HT sympatho-modulation may involve inhibitory or potentiating pathways: nitric oxide (NO), endothelium-dependent hyperpolarization (EDH)-K⁺ channels, prostanoids, angiotensin II (Ang-II), or endothelin. Compared to males, female rats show differences in the serotonergic sympatho-regulation; therefore, we aimed to study the involvement of indirect pathways via 5-HT_1D-mediated inhibition and 5-HT_2A/3-mediated potentiation of vascular noradrenergic neurotransmission in females. An i.v. bolus of different inhibitors/blockers of modulators/mediators (NO, K⁺ channels, prostanoids, Ang-II, or endothelin) was administered prior to the infusion of the agonists, L-694,247 (5-HT_1D), TCB-2 (5-HT_2A), or 1-PBG (5-HT₃), in female pithed rats. In these conditions, the vascular sympathetic outflow was electrically stimulated to assess the vasopressor responses. The L-694,247 vascular sympatho-inhibition was abolished by a non-selective K⁺ channel blocker, tetraethylammonium. The 1-PBG sympatho-excitatory vascular effect was not modified by any of the inhibitors tested, whereas TCB-2 sympatho-potentiation was blocked solely by losartan (Ang-II type 1 receptor antagonist). Moreover, Ang-II levels were increased after TCB-2 infusion in females. The EDH pathway mediates the 5-HT_1D-induced sympatho-inhibition, while the 5-HT_2A-evoked sympatho-excitatory effect is associated with Ang-II. In contrast, the 5-HT₃ sympatho-potentiation does not involve any indirect pathway. These findings advance current understanding of the complex interactions between 5-HT and vascular homeostasis in female rats. Full article

Background: Elevated serum IgE has been reported in severe COVID-19, suggesting that mast cell activation, allergic-like responses, and possible viral immune evasion occur. Objective: This study aimed to assess serum IgE, IgG, eosinophils, basophils, IL-10, and IL-33 in COVID-19 patients, and evaluate the infiltration of mast cells, basophils, and plasma cells in fatal cases. Methods: This retrospective study included 21 patients with severe COVID-19 or related respiratory conditions hospitalized in Plovdiv, Bulgaria (February 2020–May 2022). Serum immunoglobulins were quantified via immunoassays; IL-10 and IL-33 were also measured. Lung tissues from 30 autopsies were examined histologically and immunohistochemically using CD117 (mast cells) and CD138 (plasma cells). Results: Elevated IgE (>100 IU/mL) occurred in 10/21 patients, with two patients exhibiting levels exceeding 1000 IU/mL. High IgE correlated with reduced eosinophils and basophils, except in post-COVID lobar pneumonia. IL-10 was significantly increased, while IL-33 was reduced in acute and long COVID. Lung histology showed the accumulation of mast cells and plasma cells (5–20/field) during the diffuse alveolar damage and acute respiratory distress syndrome (ARDS) phases, but not in later fibrotic stages. Basophils are located near capillary basement membranes and the endothelium. Conclusions: SARS-CoV-2 may induce IgE-driven allergic-like mechanisms that contribute to severity. Monitoring IgE and mast cell activity may provide prognostic and therapeutic value, while elevated IgG4 could mitigate the effects of IgE. Full article

Background/Objectives: Biological aging phenotypes in coronary artery disease (CAD) include coronary atherosclerosis, vascular aging, and endothelial dysfunction. The aim of the present study was to investigate the potential links between aging phenotypes, regulatory immune cells, and features of the thymus in patients with CAD. Methods: A single-center, cross-sectional, comparative study was conducted. Patients were stratified according to the severity of coronary atherosclerosis: patients with a Gensini score ≥ 65 points and patients with a Gensini score < 65 points. Peripheral blood and thymus biopsy were obtained. Imaging flow cytometry, ELISA, and immunohistochemical analysis were used for analysis. Results: Thymic morphology ranged from total fatty involution to a preserved structure of the thymus (20–80% area in 31% of obtained samples) but was not associated with the severity of atherosclerosis. Meanwhile, patients with a Gensini score ≥ 65 had impaired thymus cellular composition compared to patients with a Gensini score < 65 points; increased frequency of CD8+ T lymphocytes and NK cells; and decreased frequency of CD4 + CD8+ T lymphocytes. In peripheral blood, the main determinants of a Gensini score ≥ 65 points were low absolute counts of eMDSCs and CD25^low Tregs with FoxP3 nuclear translocation, while advanced vascular aging was associated with elevated eMDSC absolute counts. Advanced coronary atherosclerosis was also associated with decreased numbers of endothelial progenitor cells in circulation. Conclusions: Thymus dysfunction accompanies CAD progression and is manifested in changes in cellular composition rather than morphology. In CAD patients, MDSC and Treg lymphocytes are equally involved in the progression of coronary atherosclerosis, which is aggravated by the decreased regulatory potential of the endothelium. Vascular aging represents a distinct phenotype of biological aging in CAD patients, characterized by the expansion of eMDSCs. Full article

Objective: To synthesize the current evidence on the cardiovascular effects of electronic cigarettes (ECs) in young adults (18–30 years), distinguishing between acute and chronic exposure, and comparing their effects to conventional tobacco (CT) use. Methods: A systematic review and meta-analysis (PROSPERO: CRD420251072847) was conducted following PRISMA guidelines. A total of 21 studies (12 RCTs, 8 case–control, 1 cohort) involving 17241 participants were included. Results: Acute EC use, particularly with nicotine, significantly increased systolic blood pressure (SBP: MD = 3.14 mmHg, 95% CI: 0.76 to 5.52), diastolic blood pressure (DBP: MD = 2.05 mmHg, 95% CI: 0.85 to 3.25), and heart rate (HR: MD = 4.23 bpm, 95% CI: 2.10 to 6.37), with effects most pronounced at 0 min post-exposure and dissipating within 1 h. Chronic EC use was associated with reduced endothelium-dependent vasodilation and early atherosclerotic changes. Nicotine-free ECs induced fewer cardiovascular alterations. Comparisons with CT revealed less severe cardiovascular damage with ECs, though still significant when compared to non-smokers. Conclusion: Nicotine-containing EC use in young individuals is associated with modest, predominantly acute and dose-dependent, cardiovascular effects, including transient increases in BP and HR. While initially less harmful than CT, the evidence is largely from cross-sectional studies and acute use, so ECs cannot be considered safe and their use warrants caution in youth. Full article

One of the main targets for snake venoms in animal and human organisms is the circulatory system. Mechanisms of circulatory system injury within the victim’s body include, among others, the direct effect of snake toxins on structures in blood vessel walls. The interaction of a toxin with cells and the extracellular matrix of the vessel wall may manifest as cytotoxicity, leading to cell death by necrosis or apoptosis, and damage to vascular wall structures. Such interactions may increase capillary permeability, promoting hemorrhage or edema, and may also induce alterations in vascular tone, resulting in changes in blood pressure. Snake toxins may also affect the growth, function, and regenerative ability of the endothelium, thus modulating angiogenesis; some toxins exert protective or anti-atherosclerotic effects. Toxins interacting with the vasculature may be classified as enzymes (phospholipases A₂, metalloproteinases, L-amino acid oxidases, and hyaluronidases), proteins without enzymatic activity (vascular endothelial growth factors, disintegrins, C-type lectins and snaclecs, three-finger toxins, etc.), peptides (bradykinin-potentiating peptides, natriuretic peptides, sarafotoxins), and low-molecular-weight substances. This review summarizes the data on the vascular effects, particularly on the blood vessel wall, exhibited by various classes and groups of snake toxins. Full article

Endothelial dysfunction (characterized by reduced vasodilation or vasoconstriction, oxidative stress, inflammation, and pro-thrombotic condition) is a critical factor in the pathophysiology of various cardiovascular conditions, and the application of anesthetics can affect this dysfunction. Patients undergoing major surgery, especially cardiovascular surgery, are at increased risk of endothelial dysfunction. The impact of anesthetics on endothelial function can vary depending on the specific agent, dosage, duration of exposure, comorbidities, etc. Certain anesthetics, especially at higher doses, may increase the production of reactive oxygen species (ROS), leading to oxidative stress and endothelial dysfunction through reduced nitric oxid (NO) availability. Some anesthetics can modulate inflammatory responses, either by suppressing or exacerbating inflammation, or may affect the permeability of the endothelium, potentially leading to pulmonary edema and disruption of the blood-brain barrier. Anesthetics can influence endothelial glycocalyx. Understanding anesthetics effects is crucial for optimizing anesthetic management, particularly in patients with pre-existing cardiovascular issues. Therefore, the aim of this review is to critically evaluate the effects of different classes of anesthetics on endothelial function and oxidative stress. Specifically, we address how anesthetics influence NO bioavailability, endothelial glycocalyx integrity, inflammatory and oxidative pathways, and clinical outcomes in surgical patients. By summarizing current evidence, we aim to highlight mechanistic insights and identify potential perioperative strategies to minimize endothelial dysfunction. Full article

Reactive oxygen species (ROS) overproduction contributes to endothelial dysfunction in Type 2 diabetes mellitus (T2DM). Pequi (Caryocar brasiliense, Camb), a native Brazilian fruit, is rich in polyphenolic antioxidants. We investigated whether its ethanolic bark extract modulates ROS levels and promotes proliferation in human coronary artery endothelial cells from patients with diabetes (D-HCAECs). Cells were treated with pequi extract under normoxic, hypoxic, or H₂O₂-induced oxidative stress conditions. Cytosolic and mitochondrial ROS levels, cell proliferation, and the expression of antioxidant proteins (Nrf2, HO-1, SOD1, SOD2, catalase, and GPx1) were assessed. Pequi significantly reduced cytosolic ROS under normoxia and both cytosolic and mitochondrial ROS under stress. It also upregulated antioxidant enzymes through the Nrf2 pathway and enhanced D-HCAEC proliferation under all tested conditions. These results suggest that pequi’s antioxidant effects may be mediated by the increased expression of endogenous enzymes, leading to improved redox balance and endothelial function in diabetic coronary vasculature. Full article

Metastatic spread remains the primary cause of mortality in melanoma. Our aim was to investigate the role of dermal endothelial cells in modulating melanoma cell invasiveness and cytokine/chemokine pattern. Primary melanoma cell lines were co-cultured with human dermal endothelial cells and assessed using Matrigel invasion assays. Invasive and non-invasive subpopulations were separated for gene expression analyses, and candidate molecules were further evaluated in patient tissue and plasma samples. Co-culture of melanoma and dermal endothelial cells revealed altered expression of several cytokine receptor genes (CCR5, CXCR7, IL1RAPL2, IL4R, IL6ST, IL18R1, IL22RA2, TNFRSF10A, TNFRSF11B, and TNFRSF21). Analysis of clinical melanoma samples showed significant downregulation of IL1RAPL2 and TNFRSF10A in cutaneous metastases, whereas IL6ST expression correlated with Breslow thickness of the primary tumor rather than metastatic site. Proteome profiling of dermal endothelial cells revealed alterations in Midkine, GROα, MIP-3α, IL-8, and SDF-1 following co-culture with melanoma cells. Plasma measurements in melanoma patients confirmed elevated Midkine levels in skin metastases and decreased MIP-3α in metastatic disease. These results highlight potential cytokine and chemokine-mediated pathways involved in melanoma dermal invasion and cutaneous metastasis. While some findings did not reach statistical significance, concordant trends between in vitro and patient-derived data suggest their relevance and warrant further investigation in larger cohorts. Full article

Antiphospholipid syndrome (APS) is the most common acquired form of thrombophilia and is associated with the presence of antiphospholipid antibodies (aPL) in the patient’s serum. Until now, the “double-hit” hypothesis remains the prevailing theory for APS pathogenesis. According to this model, the presence of aPL (first hit) is insufficient to trigger thrombosis. A secondary event, such as an inflammatory trigger or vascular injury (second hit), is required to initiate immunothrombosis, which ultimately leads to thromboembolism. Although immunothrombosis has a critical role in several mechanisms, such as in defense against pathogens, chronic immune system activation by aPL appears to disrupt its protective function. In the last three decades, the role of the complement system has gained increasing recognition in the pathophysiology of APS. aPL are involved in the dysregulation of multiple components, such as platelets, β2-glycoprotein I, and complement factor H, resulting in excessive activation of the complement system. Thus, the complement system is a key driver of thrombosis in APS and stands as a promising target for the development of future therapeutic strategies. In the current review article, we aim to summarize the ongoing research regarding the role of complement system dysregulation in APS-associated thrombosis development, while recognizing potential therapeutic targets. In the era of precision medicine, more data concerning targeted therapeutics in the field of APS are essential. Full article