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The endothelial glycocalyx covers the lumen of blood vessels throughout the body and plays an important role in endothelial homeostasis. Advances in electron microscopy techniques have provided clues to better understand the structure and composition of identical vascular endothelial glycocalyx. The morphology and thickness of the endothelial glycocalyx differ from organ to organ. The content of the endothelial glycocalyx covering the vascular lumen differs even in the brain, heart, and lungs, which have the same continuous capillaries. Various types of inflammation are known to attenuate the endothelial glycocalyx; however, we found that the morphology of the glycocalyx damaged by acute inflammation differed from that damaged by chronic inflammation. Acute inflammation breaks the endothelial glycocalyx unevenly, whereas chronic inflammation leads to the overall shortening of the endothelial glycocalyx. The same drug has different effects on the endothelial glycocalyx, depending on the location of the target blood vessels. This difference in response may reflect not only the size and shape of the endothelial glycocalyx but also the different constituents. In the cardiac tissue, the expression of glypican-1, a core protein of the endothelial glycocalyx, was enhanced. By contrast, in the pulmonary tissue, the expression of heparan sulfate 6-O-sulfotransferase 1 and endothelial cell-specific molecule-1 significantly increased in the treatment group compared with that in the no-treatment group. In this review, we present the latest findings on the evolution of the vascular endothelial glycocalyx and consider the microstructural differences.
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Coronary artery disease (CAD) remains one of the leading causes of cardiovascular morbidity and mortality worldwide. The maintenance of endothelial homeostasis and vitamin D metabolism play an important role in CAD pathogenesis. This study aimed to determine the association of endothelial homeostasis and vitamin D metabolism gene polymorphism with CAD severity. A total of 224 low-risk patients (SYNTAX score ≤ 31) and 36 high-risk patients (SYNTAX score > 31) were recruited for this study. The serum level of E-, L- and P-selectins; endothelin; eNOS; 25OH; and 1.25-dihydroxy vitamin D was measured using an enzyme-linked immunosorbent assay (ELISA). Polymorphic variants in SELE, SELP, SELPLG, END1, NOS3, VDR and GC were analyzed using a polymerase chain reaction (PCR). We found no differences in the serum levels of the studied markers between high- and low-risk patients. Three polymorphic variants associated with CAD severity were discovered: END1 rs3087459, END1 rs5370 and GC rs2298849 in the log-additive model. Moreover, we discovered a significantly decreased serum level of 1.25-dihydroxy vitamin D in high-risk CAD patients with the A/A-A/G genotypes of the rs2228570 polymorphism of the VDR gene, the A/A genotype of the rs7041 polymorphism of the GC gene and the A/A genotype of the rs2298849 polymorphism of the GC gene.
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Coronary artery disease (CAD), a leading cause of death worldwide, has a complex etiology comprising both traditional risk factors (type 2 diabetes, dyslipidemia, arterial hypertension, and cigarette smoking) and genetic factors. Vascular endothelial growth factor (VEGF) notably contributes to angiogenesis and endothelial homeostasis. However, little is known about the relationship between CAD and VEGF polymorphisms in Koreans. The aim of this study is to investigate the associations of 2 VEGF promoter region polymorphisms (−1154G>A [rs1570360], −1498T>C [rs833061]) and 4 VEGF 3'-UTR polymorphisms (+936C>T [rs3025039], +1451C>T [rs3025040], +1612G>A [rs10434], and +1725G>A [rs3025053]) with CAD susceptibility in Koreans. We studied 885 subjects: 463 CAD patients and 422 controls. Genotyping was conducted with polymerase chain reaction-restriction fragment length polymorphism analysis and TaqMan allelic discrimination assays, and the genotype frequencies were calculated. We then performed haplotype and genotype combination analyses and measured the associations between VEGF polymorphisms and clinical variables in both the CAD patients and control subjects. We detected statistically significant associations between CAD and certain VEGF allele combinations. In the haplotypes of 5 single-nucleotide polymorphisms, the VEGF allele combination −1154A/+936T was associated with a decreased prevalence of CAD (A-T-T-G-G of VEGF −1154G>A/−1498T>C/+936C>T/+1612G>A/+1725G>A, AOR = 0.077, p = 0.021). In contrast, the VEGF allele combinations −1498T/+1725A and −1498T/+1612A/+1725A were associated with an increased prevalence of CAD (G-T-C-C-A of VEGF −1154G>A/−1498T>C/+936C>T/+1451C>T/+1725G>A, AOR = 1.602, p = 0.047; T-C-C-A-A of VEGF −1498T>C/+936C>T/+1451C>T/+1612G>A/+1725G>A, AOR = 1.582, p = 0.045). Gene−environment combinatorial analysis showed that the combination of the VEGF +1725AA genotype and several clinical factors (e.g., body mass index, hemoglobin A1c, and low-density lipoprotein cholesterol) increased the risk of CAD. Therefore, we suggest that VEGF polymorphisms and clinical factors may impact CAD prevalence.
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Background Individuals infected with HIV have an increased risk of developing cardiovascular disease; yet, the underlying mechanisms remain unknown. Recent evidence has implicated the Tie-2 tyrosine kinase receptor system and its associated ligands ANG1 (angiopoietin 1) and ANG2 (angiopoietin 2) in maintaining vascular homeostasis. In the general population, lower ANG1 levels and higher ANG2 levels are strongly correlated with the development of cardiovascular disease. In this study, we aim to investigate the associations of HIV infection with angiopoietin levels and endothelial dysfunction. Methods and Results In this cross-sectional study, we compared measures of ANG1, ANG2, and endothelial dysfunction using flow-mediated vasodilation of the brachial artery in 39 untreated subjects infected with HIV, 47 treated subjects infected with HIV, and 46 uninfected subjects from the SCOPE (Observational Study of the Consequences of the Protease Inhibitor Era) cohort. Compared with uninfected controls, treated individuals infected with HIV had 53.1% lower mean ANG1 levels (P<0.01) and similar ANG2 levels. On the other hand, untreated individuals infected with HIV had similar ANG1 levels, and 29.2% had higher ANG2 levels (P<0.01) compared with uninfected controls. When compared with individuals with untreated HIV infection, those with treated HIV infection had 56% lower ANG1 levels (P<0.01) and 22% lower ANG2 levels (P<0.01).Both treated and untreated HIV infection were associated with significant impairment in hyperemic velocity, a key measure of microvascular dysfunction (median 61 versus 72 cm/s, P<0.01), compared with uninfected controls (median 73 cm/s). This difference persisted after adjustment for ANG1 and ANG2 levels. Interestingly, when compared with untreated individuals infected with HIV, treated individuals infected with HIV had worse hyperemic velocity (-12.35 cm/s, P=0.05). In contrast, HIV status, ANG1 levels, and ANG2 levels were not associated with macrovascular dysfunction as measured by flow-mediated dilatation and brachial artery diameter, 2 other measures of vascular homeostasis. Conclusions HIV infection affects the balance between levels of ANG1 and ANG2 and may disturb endothelial homeostasis through disruption of vascular homeostasis. Individuals with treated HIV had decreased ANG1 levels and similar ANG2 levels, whereas individuals with untreated HIV had similar ANG1 levels and increased ANG2 levels, suggesting that treatment status may alter the balance between ANG1 and ANG2. HIV also promotes endothelial dysfunction via impairment of microvascular dysfunction, independent of the Tie-2 receptor system; the finding of worse microvascular dysfunction in the setting of treated HIV infection may reflect the impact of viral persistence on the microvasculature or toxicities of specific antiretroviral regimens. Further research to clarify the mechanism of HIV-mediated endothelial dysfunction is necessary to advance treatment of cardiovascular complications of HIV infection.
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Angiopoyetina 1/metabolismo , Angiopoyetina 2/metabolismo , Enfermedades Cardiovasculares , Infecciones por VIH , VIH-1 , Estudios Transversales , Infecciones por VIH/diagnóstico , Infecciones por VIH/tratamiento farmacológico , Humanos , Receptor TIE-2RESUMEN
The amyloid-ß precursor protein (APP) is a ubiquitous membrane protein often associated with Alzheimer's disease (AD) and cerebral amyloid angiopathy (CAA). Despite its role in the development of the pathogenesis, APP exerts several physiological roles that have been mainly investigated in neuronal tissue. To date, the role of APP in vasculature and endothelial cells has not been fully elucidated. In this study, we used molecular and proteomic approaches to identify and investigate major cellular targets of APP down-regulation in endothelial cells. We found that APP is necessary for endothelial cells proliferation, migration and adhesion. The loss of APP alters focal adhesion stability and cell-cell junctions' expression. Moreover, APP is necessary to mediate endothelial response to the VEGF-A growth factor. Finally, we document that APP propagates exogenous stimuli and mediates cellular response in endothelial cells by modulating the Scr/FAK signaling pathway. Thus, the intact expression and processing of APP is required for normal endothelial function. The identification of molecular mechanisms responsible for vasoprotective properties of endothelial APP may have an impact on clinical efforts to preserve and protect healthy vasculature in patients at risk of the development of cerebrovascular disease and dementia including AD and CAA.
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Citoesqueleto de Actina/metabolismo , Precursor de Proteína beta-Amiloide/metabolismo , Células Endoteliales/metabolismo , Proliferación Celular , Regulación hacia Abajo , Humanos , TransfecciónRESUMEN
AIMS: Flavin adenine dinucleotide (FAD), participates in fatty acid ß oxidation as a cofactor, which has been confirmed to enhance SCAD activity and expression. However, the role of FAD on hypertensive vascular remodeling is unclear. In this study, we investigated the underlying mechanisms of FAD on vascular remodeling and endothelial homeostasis. MAIN METHODS: Morphological examination of vascular remodeling were analyzed with hematoxylin and eosin (HE) staining, Verhoeff's Van Gieson (EVG) staing, Dihydroethidium (DHE) staining and Sirius red staining. HUVECs apoptotic rate was detected by flow cytometry and HUVECs reactive oxygen species (ROS) was detected by DHE-probe. Enzymatic reactions were used to detect SCAD enzyme activity. The protein level was detected by Western Blots, the mRNA level was detected by quantitative real-time PCR. KEY FINDINGS: In vivo experiments, FAD significantly decreased blood pressure and ameliorated vascular remodeling by increasing SCAD expression, Nitric Oxide (NO) production and reducing ROS production. In vitro experiments, FAD protected against the tBHP induced injury in HUVEC, by increasing the activity of SCAD, increasing the elimination of free fatty acid (FFA), scavenging ROS, reducing apoptotic rate, thereby improving endothelial cell function. SIGNIFICANCE: FAD has a new possibility for preventing and treating hypertensive vascular remodeling.
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Acil-CoA Deshidrogenasas/metabolismo , Activadores de Enzimas/uso terapéutico , Flavina-Adenina Dinucleótido/uso terapéutico , Hipertensión/tratamiento farmacológico , Remodelación Vascular/efectos de los fármacos , Animales , Presión Sanguínea/efectos de los fármacos , Activadores de Enzimas/farmacología , Flavina-Adenina Dinucleótido/farmacología , Células Endoteliales de la Vena Umbilical Humana , Humanos , Hipertensión/metabolismo , Hipertensión/fisiopatología , Masculino , Ratas Endogámicas SHR , Ratas WistarRESUMEN
We investigated whether low-dose phloretin served as daily dietary supplements could ameliorate diabetic atherosclerosis and the role of kruppel-like factor 2 (KLF2). HUVECs cultured in high glucose medium were treated with different concentrations of phloretin and KLF2 mRNA, and protein level was detected. Diabetes was induced using streptozotocin in Apoe-/- mice after which they were fed a high-cholesterol diet for 8 weeks. Diabetic mice injected with KLF2 shRNA-lentivirus or control virus were treated with 20 mg/kg phloretin. Glucose, lipid profile, aortic atheroma, and endothelial nitric oxide synthase (eNOS) expression were detected. Phloretin retained endothelial function by KLF2-eNOS activation under hyperglycemia. Low-dose phloretin helped with lipid metabolism, and blocked the acceleration of atherosclerosis in STZ-induced diabetic mice since the early stage, which was diminished by KLF2 knockdown. Low-dose phloretin exhibited athero-protective effect in diabetic Apoe-/- mice dependent on KLF2 activation. This finding makes phloretin for diabetic atherosclerosis.
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Aterosclerosis/prevención & control , Diabetes Mellitus Experimental/complicaciones , Endotelio Vascular/metabolismo , Factores de Transcripción de Tipo Kruppel/metabolismo , Floretina/farmacología , Animales , Aterosclerosis/complicaciones , Aterosclerosis/metabolismo , Glucemia/análisis , Diabetes Mellitus Experimental/metabolismo , Relación Dosis-Respuesta a Droga , Activación Enzimática , Células Endoteliales de la Vena Umbilical Humana , Humanos , Hiperglucemia/metabolismo , Factores de Transcripción de Tipo Kruppel/genética , Lípidos/sangre , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Óxido Nítrico Sintasa de Tipo III/metabolismo , Floretina/administración & dosificación , Transducción GenéticaRESUMEN
MCP-1-induced protein (MCPIP, also known as Zc3h12a or Regnase-1), a newly identified suppressor of cytokine signaling, is expressed in endothelial cells (ECs). To investigate the role of endothelial MCPIP in vascular homeostasis and function, we deleted the MCPIP gene specifically in ECs using the Cre-LoxP system. EC-specific MCPIP deletion resulted in systemic inflammation, increased vessel permeability, edema, thrombus formation, and premature death in mice. Serum levels of cytokines, chemokines, and biomarkers of EC dysfunction were significantly elevated in these mice. Upon lipopolysaccharide (LPS) challenge, mice with EC-specific MCPIP depletion were highly susceptible to LPS-induced death. When subjected to ischemia, these mice showed defective post-ischemic angiogenesis and impaired blood flow recovery in hind limb ischemia. In aortic ring cultures, the MCPIP-deficient ECs displayed significantly impaired vessel sprouting and tube elongation. Mechanistically, silencing of MCPIP by small interfering RNAs in cultured ECs enhanced NF-κΒ activity and dysregulated synthesis of microRNAs linked with elevated cytokines and biomarkers of EC dysfunction. Collectively, these results establish that constitutive expression of MCPIP in ECs is essential to maintaining endothelial homeostasis and function by serving as a key negative feedback regulator that keeps the inflammatory signaling suppressed.
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Células Endoteliales de la Vena Umbilical Humana/metabolismo , Isquemia/metabolismo , Ribonucleasas/metabolismo , Animales , Coagulación Sanguínea , Permeabilidad Capilar , Citocinas/sangre , Eliminación de Gen , Humanos , Inflamación/metabolismo , Inflamación/patología , Isquemia/sangre , Isquemia/patología , Pulmón/patología , Ratones Noqueados , MicroARNs/metabolismo , Modelos Biológicos , FN-kappa B/metabolismo , Neovascularización Fisiológica , Especificidad de Órganos , Perfusión , Fenotipo , Ribonucleasas/deficiencia , Trombosis/sangre , Trombosis/patología , Trombosis/fisiopatologíaRESUMEN
The accelerated ageing disease Werner Syndrome (WRN) is characterized by pronounced atherosclerosis. Here, we investigated the influence of WRN downregulation on the functionality of non-replicating human endothelial cells. RNAi-mediated downregulation of WRN reduces cell motility and enhances the expression of factors regulating adhesion, inflammation, hemostasis and vasomotor tone. Moreover, WRN influences endothelial barrier function and Ca2+-release, while cell adhesion, Dil-acLDL-uptake and the mRNA expression of NO-synthases (eNOS, iNOS) remained unaffected. Regarding motility, we propose that WRN affects Rac1/FAK/ß1-integrin-related mechanisms regulating cell polarity and directed motility. Since oxidative DNA base damage contributes to aging and atherosclerosis and WRN affects DNA repair, we investigated whether downregulation of base excision repair (BER) factors mimics the effects of WRN knock-down. Indeed, downregulation of particular WRN-interacting base excision repair (BER) proteins (APE1, NEIL1, PARP1) imitates the inhibitory effect of WRN on motility. Knock-down of OGG1, which does not interact with WRN, does not influence motility but increases the mRNA expression of E-selectin, ICAM, VCAM, CCL2 and VEGFR and stimulates adhesion. Thus, individual BER factors themselves differently impact endothelial cell functionality and homeostasis. Impairment of endothelial activities caused by genotoxic stressor (tBHQ) remained largely unaffected by WRN. Summarizing, both WRN, WRN-associated BER proteins and OGG1 promote the maintenance of endothelial cell homeostasis, thereby counteracting the development of ageing-related endothelial malfunction in non-proliferating endothelial cells.
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ADN Helicasas/metabolismo , Reparación del ADN , Homeostasis , Células Endoteliales de la Vena Umbilical Humana/metabolismo , Síndrome de Werner/enzimología , Calcio/metabolismo , Adhesión Celular , Movimiento Celular , Expresión Génica , Humanos , Lipoproteínas LDL/metabolismo , Transporte de ProteínasRESUMEN
BACKGROUND: The disruption of endothelial homeostasis is a major determinant in the pathogenesis of systemic sclerosis (SSc) and is reflected by soluble and cellular markers of activation, injury and repair. We aimed to provide a combined assessment of endothelial markers to delineate specific profiles associated with SSc disease and its severity. METHODS: We conducted an observational, single-centre study comprising 45 patients with SSc and 41 healthy control subjects. Flow cytometry was used to quantify circulating endothelial microparticles (EMPs) and CD34+ progenitor cell subsets. Colony-forming unit-endothelial cells (CFU-ECs) were counted by culture assay. Circulating endothelial cells were enumerated using anti-CD146-based immunomagnetic separation. Blood levels of endothelin-1, vascular endothelial growth factor (VEGF) and soluble fractalkine (s-Fractalkine) were evaluated by enzyme-linked immunosorbent assay. Disease-associated markers were identified using univariate, correlation and multivariate analyses. RESULTS: Enhanced numbers of EMPs, CFU-ECs and non-haematopoietic CD34+CD45- endothelial progenitor cells (EPCs) were observed in patients with SSc. Patients with SSc also displayed higher serum levels of VEGF, endothelin-1 and s-Fractalkine. s-Fractalkine levels positively correlated with CD34+CD45- EPC numbers. EMPs, s-Fractalkine and endothelin-1 were independent factors associated with SSc. Patients with high CD34+CD45- EPC numbers had lower forced vital capacity values. Elevated s-Fractalkine levels were associated with disease severity, a higher frequency of pulmonary fibrosis and altered carbon monoxide diffusion. CONCLUSIONS: This study identifies the mobilisation of CD34+CD45- EPCs and high levels of s-Fractalkine as specific features of SSc-associated vascular activation and disease severity. This signature may provide novel insights linking endothelial inflammation and defective repair processes in the pathogenesis of SSc.
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Movimiento Celular , Quimiocina CX3CL1/sangre , Células Progenitoras Endoteliales/metabolismo , Esclerodermia Sistémica/metabolismo , Anciano , Antígenos CD34/metabolismo , Biomarcadores/sangre , Recuento de Células , Micropartículas Derivadas de Células/metabolismo , Células Progenitoras Endoteliales/patología , Endotelina-1/sangre , Ensayo de Inmunoadsorción Enzimática , Femenino , Citometría de Flujo , Humanos , Antígenos Comunes de Leucocito/metabolismo , Modelos Logísticos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Esclerodermia Sistémica/sangre , Esclerodermia Sistémica/patología , Índice de Severidad de la Enfermedad , Factor A de Crecimiento Endotelial Vascular/sangreRESUMEN
Over the last few years, the ETS transcription factor ERG has emerged as a major regulator of endothelial function. Multiple studies have shown that ERG plays a crucial role in promoting angiogenesis and vascular stability during development and after birth. In the mature vasculature ERG also functions to maintain endothelial homeostasis, by transactivating genes involved in key endothelial functions, while repressing expression of pro-inflammatory genes. Its homeostatic role is lineage-specific, since ectopic expression of ERG in non-endothelial tissues such as prostate is detrimental and contributes to oncogenesis. This review summarises the main roles and pathways controlled by ERG in the vascular endothelium, its transcriptional targets and its functional partners and the emerging evidence on the pathways regulating ERG's activity and expression.
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Endotelio Vascular/fisiología , Neovascularización Fisiológica/fisiología , Animales , Regulación de la Expresión Génica , Homeostasis , Humanos , Neovascularización Fisiológica/genética , Regulador Transcripcional ERG/genética , Regulador Transcripcional ERG/metabolismoRESUMEN
Endothelial cells (ECs) are constantly exposed to xenobiotics and endobiotics or their metabolites, which perturb EC function, as well as to shear stress, which plays a crucial role in vascular homeostasis. Pregnane X receptor (PXR) is a nuclear receptor and a key regulator of the detoxification of xeno- and endobiotics. Here we show that laminar shear stress (LSS), the atheroprotective flow, activates PXR in ECs, whereas oscillatory shear stress, the atheroprone flow, suppresses PXR. LSS activation of PXR in cultured ECs led to the increased expression of a PXR target gene, multidrug resistance 1 (MDR1). An in vivo study using rats showed that the expression of MDR1 was significantly higher in the endothelium from the descending thoracic aorta, where flow is mostly laminar, than from the inner curvature of aortic arch, where flow is disturbed. Functionally, LSS-activated PXR protects ECs from apoptosis triggered by doxorubicin via the induction of MDR1 and other detoxification genes. PXR also suppressed the expression of proinflammatory adhesion molecules and monocyte adhesion in response to TNF-α and lipopolysaccharide. Overexpression of a constitutively active PXR in rat carotid arteries potently attenuated proinflammatory responses. In addition, cDNA microarray revealed a large number of the PXR-activated endothelial genes whose products are responsible for major steps of detoxification, including phase I and II metabolizing enzymes and transporters. These detoxification genes in ECs are induced by LSS in ECs in a PXR-dependent manner. In conclusion, our results indicate that PXR represents a flow-activated detoxification system to protect ECs against damage by xeno- and endobiotics.