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Effects of semaglutide and empagliflozin on markers of endothelial function in persons with type 2 diabetes: A post hoc analysis of a randomized clinical trial.

AIMS: The endothelium maintains vascular health by regulating blood flow and protecting against inflammatory damage. In type 2 diabetes (T2DM), however, hyperglycemia, hypertension, and hyperlipidemia place a significant burden on the endothelium, potentially leading to atherosclerosis and cardiovascular disease (CVD). While semaglutide and empagliflozin have been shown to reduce CVD risk in T2DM, it remains unclear whether these benefits are mediated by improved endothelial function. This post-hoc analysis explores the effects of these agents on markers of endothelial function, i.e. the reactive hyperaemic index (RHI) and the endothelial-derived cell adhesion molecules (CAMs) E-Selectin, ICAM-1, P-Selectin, and VCAM-1. METHODS: This was a post-hoc analysis of a 32-week randomized trial evaluating the separate and combined effects of semaglutide and empagliflozin on cardio-renal organ damage. One hundred and twenty participants with type 2 diabetes, age&#xa0;&#x2265;&#xa0;50 were randomized to four groups (semaglutide, empagliflozin, the combination or placebo). An increase in RHI and/or a decrease in CAMs were considered beneficial. RESULTS: RHI increased compared to baseline (0.11, 95%CI [0.008;0.21], p&#xa0;=&#xa0;0.03) but not compared to placebo in the semaglutide group (0.11, 95%CI [-0.04;0.24], p&#xa0;=&#xa0;0.16). There was no effect on RHI in the empagliflozin group. Compared to placebo, E-Selectin decreased significantly in the semaglutide and combination groups (-9, 95%CI [-14.1;-5.1] p&#xa0;<&#xa0;0.01 and&#xa0;-&#xa0;9, 95%CI [-14.3; -5.2] p&#xa0;<&#xa0;0.01, respectively). VCAM-1 increased in the same groups, compared to placebo (12.3, 95%CI[2.8;20.8] p&#xa0;=&#xa0;0.01 and 16.2, 95%CI [7.2;24.3], p&#xa0;<&#xa0;0.01, respectively).P-Selectin and ICAM-1 was not significantly affected in any of the groups, compared to placebo (p&#xa0;&#x2265;&#xa0;0.11 and p&#xa0;&#x2265;&#xa0;0.09, respectively). CONCLUSION: Semaglutide improved endothelial function compared to baseline, but not significantly versus placebo, which likely is due to limited power. CAM responses were heterogeneous, suggesting distinct roles in endothelial dysfunction and atherosclerosis. ClinicalTrialsRegister.eu: EudraCT 2019-000781-38.

Aged

Guidelines for evaluating endothelial function in vascular tissue.

The endothelium plays a central role in maintaining vascular homeostasis by orchestrating vascular tone, inflammation, healing, permeability, and thrombosis. Assessing endothelial function in vascular tissue is essential for understanding the cellular and molecular mechanisms underlying cardiovascular physiology and pathology. Traditional approaches, such as wire and pressure myography, have been instrumental in defining endothelium-dependent responses and identifying key pharmacological targets. However, the complexity and heterogeneity of endothelial cells across vascular beds and their dynamic phenotypic changes in health and disease necessitate the incorporation of new investigative strategies. Emerging methodologies, including bulk and single-cell transcriptomics, proteomics, and advanced imaging, now provide unprecedented insights into endothelial cell diversity and function. A team of leading experts in the field, who collectively reached a consensus on the most widely used techniques to evaluate endothelial function, developed these guidelines. The document establishes best practices for assessing endothelial function, from endothelial cell cultures to isolated vascular tissues, integrating conventional functional assays with modern molecular approaches. By fostering methodological consistency and embracing innovation, our goal is to enhance rigor, reproducibility, understanding, and discovery in endothelial biology.

Humans

Supplementations of docosahexaenoic acid and blueberry suppress a high-fat breakfast-induced postprandial inflammation but only docosahexaenoic acid improves endothelial function in healthy adults: a randomized, double-blind, placebo-controlled crossover intervention study.

Blueberries and n - 3 polyunsaturated fatty acids each can provide protection against inflammation and cardiometabolic disorders. However, the underlying mechanisms are not fully understood. We hypothesized that blueberry and docosahexaenoic acid (DHA) can suppress high fat (HF) meal-induced postprandial inflammation and improve endothelial function. Sixty-two healthy participants (age: 26.8 &#xb1; 1.2 y; BMI: 22.1 &#xb1; 1.2 kg/m&#xb2;) consumed an isoenergetic breakfast (850 kcal) containing 34.7 g mostly animal fat (36% kcal), 25.3 g protein, and 111 g carbohydrate, with or without either 42.2 g blueberry powder (BBP) or 1.76 g DHA in a randomized, double-blind, placebo-controlled crossover intervention study. Blood samples were collected before and 1 h, 3 h and 6 h after breakfast. Monocyte activation, proinflammatory gene expression, cytokine production and endothelial function were assessed. Compared with the placebo control, DHA supplementation suppressed the HF breakfast-induced: expression of IL-1&#x3b2; by 21.6% (P < .01) and prostaglandin-endoperoxide synthase 2 (PTGS2, i.e., cyclooxygenase 2) by 22.8% (P < .01) at 6 h; plasma IL-1&#x3b2; production by 40.1 to 49.8% (P < .01) at 1-6 h; lipoprotein lipase (LPL)-treated blood IL-1&#x3b2; production by 40.9% (P < .0001) at 6 h; and total cholesterol/HDL cholesterol ratio by 2.2% (P < .01) at 3 h and 3.5% (P < .0001) at 6 h. BBP supplementation suppressed LPL-treated blood IL-1&#x3b2; production by 23.1% (P < .05) at 6 h. BBP and DHA also induced postprandial increases in reactive hyperemia index (RHI) scores relative to the fasting baselines, with DHA producing a 13.3% increase compared with placebo at 6 h (P < .05). In conclusion, supplementation with BBP or DHA suppressed the HF meal-induced postprandial inflammation but only DHA improved postprandial endothelial function. This study was registered at clinicaltrails.gov (NCT02472171).

Blueberry

Endothelial function in relation to low-level chronic residential air pollution in a general population: a cohort study.

BACKGROUND: Given the recently updated clean-air targets, this population study assessed endothelial function at low exposure to particulate matter with an aerodynamic diameter of &#x2264;10&#xa0;&#xb5;m (PM10) and &#x2264;2.5&#x2009;&#xb5;m (PM2.5), nitrogen dioxide (NO2) and black carbon (BC). METHODS: In 453 Flemish participants (47.7% women; mean age, 52.8&#x2009;years), endothelial function was assessed by finger photoplethysmography after 5&#x2009;min of ischaemia. The outcome measures were the maximal ischaemic-to-control ratio (Rmax) and the maximal difference (Dmax) in pulse amplitude between the test and control fingers. The air pollutants were related to Rmax and Dmax using mixed models accounting for coresidence, to cardiovascular endpoints by proportional hazards regression, and to residential address by high-resolution spatiotemporal interpolation. RESULTS: From 2010 to 2015, PM10, PM2.5, NO2 and BC decreased (p&#x2009;<&#x2009;0.0001) with 6-year levels averaging 15.9, 12.8, 14.3 and 1.04&#xa0;&#xb5;g/m3. Irrespective of adjustment for risk factors, Dmax was inversely correlated with PM2.5, while associations of Rmax with PM2.5 and associations of both Dmax and Rmax with other pollutants were weaker (p values <0.10), but consistently inverse. Association sizes of Rmax and Dmax with PM10 and PM2.5 weakened over 6&#xa0;years, paralleling the decreasing air pollutants (p&#x2009;&#x2264;&#x2009;0.044). In adjusted analyses, the risk of a composite cardiovascular endpoint decreased (p&#x2009;&#x2264;&#x2009;0.043) with higher Rmax and Dmax with hazard ratios ranging from 0.31 to 0.49. Finally, in the geographical analysis, endothelial dysfunction followed the spatial gradients in PM2.5. CONCLUSIONS: Long-term low-level air pollution is associated with subclinical endothelial dysfunction, the initial and critical step leading to adverse cardiovascular outcomes.

Humans

The endothelial function of donor corneas: effects of delayed enucleation and refrigeration.

The endothelial viability of rabbit corneas subjected to various forms of cadaveric and moist chamber storage was evaluated by means of the specular microscope and the rate of stromal deturgescence during a temperature reversal response. Delays in the postmortem enucleation and refrigeration of potential donor corneas was shown to be detrimental to the functioning of the endothelium. To best preserve the endothelial function of donor corneas, the eyes should be removed as soon after death as possible and refrigerated at 4 degrees C. Refrigerated cadaveric storage was found not to be a substitute for early enucleation and refrigeration of the corneas. The limitations in the use of the rate of stromal deturgescence during a temperature reversal response as a quantitative indicator of endothelial function are discussed.

Animals

Targeted Nrf2 activation improves vascular endothelial function with aging and prevents vascular dysfunction following disuse in younger and older adults.

Aging and physical inactivity/disuse contribute to cardiovascular disease, which is attributable, in part, to vascular endothelial dysfunction associated with impaired nuclear-factor erythroid 2-related factor 2 (Nrf2) signaling. However, the ability to augment Nrf2 activation and its effects on age- and disuse-related vascular dysfunction in humans remains limited. In a double-blind, randomized, placebo-controlled study design 20 younger adults (8M/12F, age 27&#x202f;&#xb1;&#x202f;7&#x202f;y) and 24 older adults (12M/12F, age 67&#x202f;&#xb1;&#x202f;8&#x202f;y) were randomized to receive either placebo or PB125 (200&#x202f;mg/day, Nrf2 activator) across three visits: baseline, 2 weeks of supplementation, and following either 5 days of bed rest (old) or 2 weeks of limb immobilization (young). Brachial and popliteal artery flow-mediated dilation (FMD), passive leg movement-induced (PLM) leg blood flow (LBF) and vascular conductance (LVC) and serum antioxidant status (superoxide dismutase, SOD) were assessed at each timepoint. Compared to placebo, 2 weeks of PB125 increased brachial (PB125: 2.8&#x202f;&#xb1;&#x202f;1.5 to 3.8&#x202f;&#xb1;&#x202f;1.3%, p&#x202f;<&#x202f;0.0001) and popliteal FMD (PB125: 1.5&#x202f;&#xb1;&#x202f;1.5 to 2.3&#x202f;&#xb1;&#x202f;1.4%, p&#x202f;=&#x202f;0.033) in older, but not younger adults (both, p&#x202f;>&#x202f;0.27). During bed rest, PB125 preserved brachial (3.8&#x202f;&#xb1;&#x202f;1.3 to 3.6&#x202f;&#xb1;&#x202f;1.4%, p&#x202f;=&#x202f;0.543) and popliteal FMD (2.3&#x202f;&#xb1;&#x202f;1.4 to 2.7&#x202f;&#xb1;&#x202f;1.4%, p&#x202f;=&#x202f;0.269), LVC (1.1&#x202f;&#xb1;&#x202f;0.8 to 1.1&#x202f;&#xb1;&#x202f;1.5 AUC, p&#x202f;=&#x202f;0.530) and circulating SOD concentrations (28.3&#x202f;&#xb1;&#x202f;7.2 to 28.6&#x202f;&#xb1;&#x202f;8.6 U/mL, p&#x202f;=&#x202f;0.888) in older adults compared to placebo (all, p&#x202f;<&#x202f;0.05). Following limb immobilization, PB125 preserved popliteal FMD (4.4&#x202f;&#xb1;&#x202f;2.8 to 3.4&#x202f;&#xb1;&#x202f;1.8%, p&#x202f;=&#x202f;0.302) in younger adults compared to placebo (p&#x202f;<&#x202f;0.05). These findings demonstrate targeted Nrf2 activation with PB125 improves age-related vascular endothelial dysfunction while preserving vascular function and antioxidant capacity following periods of disuse.

Humans

Photodynamically induced alteration of cornea endothelial cell function.

Corneal endothelial cells were perfused in the specular microscope with varying concentrations of rose bengal. Corneas perfused with rose bengal in concentrations of 10(-6)M to 10(-5)M and exposed to light for periods of 0.5 to 5 min swelled at rates which were more rapid with both increasing concentration of rose bengal and increasing duration of light exposure. Corneas perfused with similar concentrations of rose bengal but not exposed to light did not swell. Combining rose bengal with 100 micrograms/ml superoxide dismutase did not reduce the corneal swelling following exposure to light, indicating that the photodynamically induced endothelial bengal perfusing solution eliminated corneal swelling following exposure of corneas to light. This indicates that the photodynamic effect of endothelium is secondary to cell functional alterations from the hydrogen peroxide produced during the dismutation reaction of superoxide free radical which is catalyzed by superoxide dismutase.

Animals

Effects of Sacubitril Valsartan Combined With Vericiguat on NT-proBNP and CK-MB Levels in Patients With Chronic Heart Failure.

This study aims to probe the influence of sacubitril valsartan sodium tablets combined with vericiguat on N-terminal pro-B-type natriuretic peptide (NT-proBNP) and creatine kinase isoenzyme (CK-MB) levels in patients with chronic heart failure (CHF). One hundred and twenty CHF patients were enrolled and stratified into a control group (sacubitril valsartan sodium tablets) and a combination group (sacubitril valsartan sodium tablets&#x2009;+&#x2009;vericiguat). Outcome measures included New York Heart Association (NYHA) functional class shifts, echocardiographic indices, cardiac injury markers, 6-min walk distance (6MWD), endothelial function parameters, inflammatory mediator levels, and adverse clinical events. Following a 6-month treatment period, patients in the combination group exhibited superior functional improvement, as reflected by greater advancement in NYHA class. Echocardiographic evaluation revealed more favorable ventricular remodeling in this group, with reduced left ventricular end-diastolic and end-systolic diameters and an elevated ejection fraction. The combination group had a higher 6MWD. Biomarker analysis showed lower NT-proBNP and CK-MB levels in the combination group. Furthermore, improvements in endothelial function were noted, with decreased endothelin and elevated NO, NOS, and CGRP levels in the combination group. Markers of systemic inflammation, including CRP and IL-6, were also attenuated in the combination group. The incidence of adverse reactions and cardiovascular events did not differ significantly between the groups. Co-administration of sacubitril/valsartan and vericiguat enhances cardiac performance, optimizes vascular endothelial responsiveness, modulates heart failure-related biomarkers, and mitigates inflammatory activity in patients with CHF without increasing the risk of adverse events.

Humans

Brain perivascular macrophages regulate endothelial cell function via a cMAF-dependent transcriptional program in mouse and human.

Brain perivascular macrophages maintain brain physiology, yet their transcriptional regulators and functions in health and disease remain unclear. Using single-cell multi-omics and functional experiments, we identify cellular musculoaponeurotic fibrosarcoma oncogene (cMAF) as a key transcription factor for brain perivascular macrophages, and conditional deletion of cMAF disrupts their phenotype in vivo. Functionally, cMAF drives insulin-like growth factor-1 (IGF1) expression in perivascular macrophages, enabling communication with endothelial cells. Consistently, cMAF deletion in perivascular macrophages causes transcriptional alterations in cerebral arteries, affecting vascular functions. Notably, cMAF emerges as the main transcription factor for human perivascular macrophages, suggesting conservation of this transcriptional module. During Alzheimer's disease (AD), human perivascular macrophages upregulate cMAF and IGF1 to enhance communication with vascular cells, and this response is abrogated in APOE4 carriers. Lastly, we explore an uncharacterized polymorphism in cMAF, providing evidence that the cMAF program is protective against AD. Targeting cMAF in perivascular macrophages may offer new therapeutic strategies for neurodegenerative and cerebrovascular diseases.

APOE4

The effect of penile tourniquet and continuous artificial erection on penile erectile tissues: An experimental study.

INTRODUCTION: Penile tourniquet (PT) is known to cause ischemic injury, which worsens with prolonged application. Artificial erection (AE), formed by intracorporal saline injection mostly under PT, has been practiced for decades to evaluate penile curvature, yet its effect on erectile tissues has never been investigated. In this study, we examined a modified approach, continuous artificial erection (CAE), and investigated its effects on erectile tissues. OBJECTIVE: This study aims to investigate the histopathological and immunohistochemical effects of CAE on penile erectile tissues. STUDY DESIGN: Thirty-five rats were randomized into five groups. Four experiment groups received 20 or 40 min of isolated PT (20T and 40T) or PT with CAE (20T&E and 40T&E). CAE was achieved through continuous intracavernosal saline injection. Penectomy was performed three weeks post-procedure in the experiment groups and directly in the control group. Erectile tissue samples were evaluated using light microscopy for histopathological parameters including inflammation, neovascularization and fibrosis, and by immunohistochemistry. Endothelial function was assessed by eNOS and e-selectin staining, while ICAM-1 staining was used to assess chronic inflammation. RESULTS: 40T showed the highest levels of inflammation, fibrosis, and endothelial dysfunction. 20T had significantly less inflammation than 40T, with a non-significant increase in fibrosis and alteration of endothelial markers. 40T&E displayed the second-highest fibrosis rate (adjusted p > 0.05), while 20T&E showed complete absence of fibrosis. Both 40T&E and 20T&E preserved strong eNOS and e-selectin expression, identical to controls. ICAM-1 expression in 20T&E was also consistent with the control group. The most significant difference in erectile tissue damage was noted between 40T and 20T&E. CONCLUSION: This is the first study to evaluate the effects of AE on erectile tissues. Findings of this experimental model support that, CAE does not increase the tissue damage that is already caused by PT, but rather reduces it, likely through the washout of blood elements contributing to reperfusion injury. CAE possibly provides a protective effect on erectile tissues by preserving endothelial function, reducing inflammation and fibrosis, especially under 20 minutes of duration. These findings may support that AE maneuvers such as "artificial erection test" and CAE are potentially safe, while further studies are needed to assess the detailed effects of CAE.

Male

Optimizing physical activity bouts to interrupt sedentary behaviour for cardiometabolic health: a systematic review and meta-analyses of randomized controlled trials.

AIMS: Chronic diseases such as type 2 diabetes mellitus and cardiovascular diseases are leading causes of mortality worldwide, with sedentary behaviour (SB) and physical inactivity recognized as major interrelated risk factors. Prolonged SB, particularly when combined with insufficient physical activity, adversely affects cardiometabolic health. This systematic review aimed to evaluate which characteristics of physical activity (PA) bouts, in terms of frequency, duration, and intensity, are associated with improvements in cardiometabolic outcomes. METHODS AND RESULTS: Studies assessing physical activity interventions compared with sedentary control conditions were included. Eligible studies involved adults aged 18-65 years, with or without cardiometabolic conditions. PubMed, Cochrane Central, Embase, and Web of Science were searched to February 2025. Random-effects models were used to calculate pooled standardized mean differences (SMD) with 95% confidence interval (CI). Subgroup and meta-regression analyses explored potential moderators. A total of 144 studies (247 intervention arms; 2216 participants) were included. Frequent PA bouts reduced blood glucose [SMD -0.22 (95% CI -0.27 to -0.16)]. Longer and/or more intense PA bouts decreased triglycerides [SMD -0.27 (-0.34 to -0.19)], with significant duration &#xd7; intensity interactions for glucose (P = 0.032) and triglycerides (P < 0.001). Moderate-to-vigorous PA bouts improved endothelial function [flow-mediated dilation SMD 0.88 (0.47-2.24); shear rate SMD 0.54 (0.31-0.78)]. PA bouts also lowered insulin [SMD -0.26 (-0.32 to -0.19)], systolic BP [SMD -0.29 (-0.39 to -0.19)], and diastolic BP [SMD -0.16 (-0.26 to -0.05)]. CONCLUSION: In acute experimental settings, glucose regulation appears to benefit more from frequent PA bouts, while triglyceride responses are more closely related to greater duration and/or intensity. Blood pressure shows favourable acute responses across PA types, whereas higher PA intensity is associated with improved endothelial function. Tailoring strategies to interrupt SB with PA bouts may help inform approaches to improve cardiometabolic health.

Humans

The endothelium: roles in thrombosis and hemostasis.

The renewed interest in endothelial function is based partly on success with tissue culture of endothelial cells. Endothelium functions primarily in the control of blood vessel wall permeability and in the provision of a blood-compatible lining surface. Recent findings indicate that endothelial cells are active metabolically in ways that may help prevent thrombosis. Endothelium actively degrades several different vasoactive compounds that circulate in blood and that can serve as platelet-aggregating agents. Endothelium also contains an inhibitor of platelet function and an activator of plasminogen, both of which can be released from the cell in response to appropriate stimuli. While intact endothelium functions primarily in prevention of thrombosis, damaged endothelium can contribute greatly to thrombus formation. Release of prostaglandins, adenine nucleotides, and other intracellular components from damaged endothelium can enhance platelet aggregation. Damaged endothelium may not function effectively in removal of vasoactive agents and may not release effective quantities of the inhibitor of platelet function or the activator of plasminogen. Altered endothelium exhibits tissue-factor activity, which can activate the extrinsic blood coagulation-system cascade. Finally, altered endothelial cells may contract and expose basement membrane to blood, thus enhancing thrombosis.

Blood Coagulation

Premeal insulin administration lowers postprandial blood glucose and increases myocardial microvascular blood flow in people with type 1 diabetes: a randomised, crossover clinical trial.

AIMS/HYPOTHESIS: We aimed to evaluate whether prandial insulin timing affects vascular function in people with type 1 diabetes. Our hypothesis was that premeal insulin administration would lead to greater myocardial microvascular blood flow (MBF) via blunting postprandial hyperglycaemia. METHODS: People with type 1 diabetes between 18 and 35 years of age with BMI <30 kg/m2 underwent two protocols with a 1:1 randomised crossover design wherein prandial insulin was injected either 15 min before or 15 min after meal intake began. To provide a physiological comparison, age-, sex- and BMI-matched control participants completed one study where they consumed the same meal but received no exogenous insulin. Glucose, insulin, vascular function (including ultrasound measures of myocardial and skeletal muscle microvascular perfusion, aortic stiffness, brachial artery endothelial function) and biomarkers of systemic inflammation and endothelial dysfunction were assessed at baseline and then 2 h after meal ingestion within each protocol. The primary outcome was change in myocardial MBF within each protocol. Study personnel assessing outcomes were masked to group assignment. RESULTS: Eighteen people with type 1 diabetes and 18 matched control participants were analysed within each protocol. Glucose area under the curve was significantly greater (p=0.015) in the postmeal insulin study compared with the premeal insulin study in participants with type 1 diabetes. Myocardial microvascular flow velocity significantly increased (p=0.031) with premeal insulin administration in people with type 1 diabetes and this consequently led to greater myocardial MBF (p=0.044). There were no changes in myocardial MBF within the other protocols. Changes in vital signs were similar between all protocols. CONCLUSIONS/INTERPRETATION: Appropriately timed premeal insulin led to lower postprandial blood glucose along with increased myocardial MBF in people with type 1 diabetes. Further work is needed to determine the underlying aetiology of these changes. TRIAL REGISTRATION: ClinicalTrials.gov NCT04730882.

Humans

Human iPSC-EV-loaded nanofiber stent coatings accelerate vascular repair by enhancing EGFR/HIF-1&#x3b1; signaling and suppressing ROCK1-mediated remodeling.

Arterial disease management is shifting from antiproliferative drug-eluting stents toward approaches that restore endothelial function and modulate smooth muscle cell (SMC) behavior. Stem cell-derived extracellular vesicles (EVs) carry miRNAs that promote endothelial proliferation and migration while restraining aberrant SMC growth and inflammation. Here, human induced pluripotent stem cell (iPSC)-derived EVs were collected by ultracentrifugation and incorporated into 50:50 poly (lactic-co-glycolic acid) (PLGA 503) core-shell nanofibrous membranes, which were fabricated as stent coatings for sustained release to overcome rapid clearance and poor tissue retention. EVs derived from three independent iPSC lines all enhanced tube formation in human umbilical vein endothelial cells (HUVECs) under hypoxic and serum-starved conditions and revealed a trend toward reduced platelet-derived growth factor-BB (PDGF-BB)-induced smooth muscle cell (SMC) migration. The fabricated core-shell nanofibers enabled sustained EV release, maintaining therapeutic efficacy for 28 days. Small RNA sequencing (NGS) analysis demonstrated that EVs from these independent iPSC lines shared miR-148a-3p and members of the miR-92 family, which collectively accounted for more than 75% of the reads within the 25 top-expressed miRNA set. In vitro, iPSC-EVs enhanced HUVEC proliferation and survival signaling by downregulating the negative regulators ERRFI1 and VHL, which are specific targets of miR-148a-3p and the miR-92 family, thereby activating the EGFR and HIF-1&#x3b1; axes and driving downstream ERK1/2 and VEGF expression under hypoxic and serum starvation stress conditions. Concurrently, iPSC-EVs prevented PDGF-BB-induced SMC phenotypic switching by downregulating ROCK1, a target of miR-148a-3p, thereby inhibiting downstream AKT and ERK signaling and preserving contractile markers while suppressing the synthetic phenotype. In vivo, the iPSC-EV-functionalized scaffolds significantly accelerated re-endothelialization and inhibited neointimal hyperplasia, evidenced by the upregulation of angiogenic factors (VEGF, CD31) and the concurrent suppression of pathological remodeling markers (&#x3b1;-SMA, MMPs) and inflammatory cytokines (IL-6, TGF-&#x3b2;1). Therefore, iPSC-EVs enriched with specific miRNAs and delivered via PLGA 503 core-shell nanofibers promote endothelial repair while suppressing SMC overgrowth, providing a promising strategy for vascular healing.

Core-shell nanofibers

[Vascular endothelium (author's transl)].

Studies during recent years have shown the importance of the vascular endothelium in several physiological and pathological circumstances. The culture of endothelial cells has permitted the direct study of endothelial functions. The endothelium is a selective barrier between blood and tissues: the molecules cross it, according to their size, either through the intercellular junctions or through the cells by pinocytotic vesicles. The permeability is modulated by vasomotor agents and modified during endothelial regeneration, especially for the lipids. The endothelium plays a prominent part in the maintenance of the blood flow through its nonthrombogenic properties. It metabolizes circulating thrombogenic substances (arachidonic acid, adenosine diphosphate) and produces potent antiaggregating agents (prostacyclin and adenosine). It may also release a plasminogen activator promoting thrombolysis. The endothelial cells contribute to the formation of the basement membrane by synthesizing collagen and fibronectin, which are involved in platelet adhesion and aggregation to exposed subendothelium. On the other hand, the endothelium has a modulating influence on the local blood flow by producing vasoconstrictors (angiotensin II and III) and vasodilating agents (adenosine and prostacyclin). It is not necessary to elucidate the coordination of these functions and their relationship to the endothelial disorders in vascular diseases.

Actins

Clinical specular microscopy.

Clinical specular microscopy (CSM) has recently been introduced as a means of qualitative and quantitative examination of the human corneal endothelium at high magnification. With the aid of CSM, a decline in endothelial cell density with age has been documented and several endothelial abnormalities from disease or trauma can be detected. Donor material for corneal grafting can be examined by CSM and keratoplasty procedures can be designed to decrease endothelial damage. Cataract surgical procedures can cause endothelial cell loss. According to most studies, intracapsular extraction causes less cell loss than does phacoemulsification, and cataract extraction with intraocular lens (IOL) insertion causes the greatest loss. Cell loss from IOL can be minimized by decreasing lens-corneal contact. Elevated intraocular pressure may lead to endothelial cell loss, as may therapy with epinephrine. Endothelial toxicity of other drugs and solutions can be studied by CSM. While long term studies are necessary to correlate the morphologic changes detected by CSM with future endothelial function, shortterm studies can be helpful in developing medical and surgical techniques that minimize corneal endothelial trauma.

Adolescent

Effect of epinephrine on the corneal edothelium.

Intracameral epinephrine has been advocated for treatment of iris bleeding and inadequate pupillary dilatation during intraocular surgery. Commercial epinephrine 1:1000 with its preservative sodium bisulfite damaged corneal endothelial function and ultrastructure in rabbit and monkey eyes with sodium bisulfite the source of the damage. Endothelial damage can be prevented with a 1:5000 dilution of commercially available epinephrine in 0.1% sodium bisulfite or freshly prepared epinephrine bitartrate 1:1000 with a bicarbonate Ringers.

Animals