A prominent feature of inflammatory diseases is endothelial dysfunction. Factors associated with endothelial dysfunction include proinflammatory cytokines, adhesion molecules, and matrix degrading enzymes. At the transcriptional level, they are regulated by the histone deacetylase sirtuin (SIRT) 1 via its actions on the proinflammatory transcription factor nuclear factor-κB (NF-κB). The role of SIRT6, also a histone deacetylase, in regulating inflammation in endothelial cells is not known. The aim of this study was to determine the effect of SIRT6 knockdown on inflammatory markers in human umbilical vein endothelial cells (HUVECs) in the presence of lipopolysaccharide (LPS). LPS decreased expression of SIRT6 in HUVECs. Knockdown of SIRT6 increased the expression of proinflammatory cytokines (IL-1β, IL-6, IL-8), COX-prostaglandin system, ECM remodelling enzymes (MMP-2, MMP-9 and PAI-1), the adhesion molecule ICAM-1, and proangiogenic growth factors VEGF and FGF-2; cell migration; cell adhesion to leukocytes. Loss of SIRT6 increased the expression of NF-κB, whereas overexpression of SIRT6 was associated with decreased NF-κB transcriptional activity. Taken together, these results demonstrate that the loss of SIRT6 in endothelial cells is associated with upregulation of genes involved in inflammation, vascular remodelling, and angiogenesis. SIRT6 may be a potential pharmacological target for inflammatory vascular diseases.

Mono-(2-ethylhexyl) phthalate (MEHP), the active metabolite of di-(2-ethylhexyl) phthalate (DEHP), is a widespread environmental contaminant and has been proved to have potential adverse effects on the reproductive system, carcinogenicity, liver, kidney and developmental toxicities. However, the effect of MEHP on vascular system remains unclear. The main purpose of this study was to evaluate the cytotoxic effects of MEHP on human umbilical endothelial cells (HUVEC) and its possible molecular mechanism. HUVEC cells were treated with MEHP (0, 6.25, 12.5, 25,50 and 100 µM), and the cellular apoptosis and mitochondrial membrane potential as well as intracellular reactive oxygen species were determined. In present study, MEHP induced a dose-dependent cell injury in HUVEC cell via an apoptosis pathway as characterized by increased percentage of sub-G1, activation of caspase-3, -8 and -9, and increased ratio of Bax/bcl-2 mRNA and protein expression as well as cytochrome C releasing. In addition, there was obvious oxidative stress, represented by decreased glutathione level, increased malondialdehyde level and superoxide dismutase activity. N-Acetylcysteine, as an antioxidant that is a direct reactive oxygen species scavenger, could effectively block MEHP-induced reactive oxygen species generation, mitochondrial membrane potential loss and cell apoptosis. These data indicated that MEHP induced apoptosis in HUVEC cells through a reactive oxygen species-mediated mitochondria-dependent pathway.

We have previously demonstrated that therapy with orally administered L-glutamine improves nicotinamide adenosine dinucleotide (NAD) redox potential of sickle red blood cells (RBC). On further analysis of L-glutamine therapy for sickle cell anemia patients, the effect of L-glutamine on adhesion of sickle RBC to human umbilical vein endothelial cells (HUVEC) was examined.

Hyperhomocysteinemia is an independent risk factor for cardiovascular diseases. The enhanced nitrative stress plays an important role in homocysteine-induced endothelial dysfunction. Previous studies have showed that phytoestrogen α -zearalanol alleviated endothelial injury in ovariectomized hyperhomocysteinemic rats; however, the underlying mechanism remains to be clarified. This study was to investigate the effects of α -zearalanol on homocysteine-induced endothelial apoptosis in vitro and explore the possible role of nitrative stress in these effects. Results showed that homocysteine (500  μ mol/L, 24 h) induced the apoptosis of human umbilical vein endothelial cells (HUVECs) obviously, and this effect was significantly attenuated by pretreatment with α -zearalanol (10(-8)~10(-6) mol/L). Moreover, α -zearalanol downregulated proapoptotic protein Bax, upregulated antiapoptotic proteins Bcl-2 and Bcl-XL, and decreased the expression and activity of caspase-9. These findings demonstrated that α -zearalanol could effectively alleviate homocysteine-induced endothelial apoptosis, and this antiapoptosis effect might be related to the inhibition of the intrinsic pathway. Western blot indicated an enhanced 3-nitrotyrosine expression in HUVECs when challenged with homocysteine, which was attenuated by pretreatment with α -zearalanol. This result implied that inhibition of nitrative stress might play a role in the protective effect of α -zearalanol on endothelial cells. Such discovery may shed a novel light on the antiatherogenic activities of α -zearalanol in hyperhomocysteinemia.

Despite the well-established sex-specific differences in the incidence of bronchopulmonary dysplasia (BPD), the molecular mechanism(s) behind these are not completely understood. Pulmonary angiogenesis is critical for alveolarization and arrest in vascular development adversely affects lung development. Human neonatal umbilical vein endothelial cells (HUVECs) provide a robust in vitro model for the study of endothelial cell physiology and function. Male and Female HUVECs were exposed to room air (21% O2, 5% CO2) or hyperoxia (95% O2, 5% CO2) for up to 72 h. Cell viability, proliferation, H2O2 production and angiogenesis were analyzed. Sex-specific differences in the expression of VEGFR2 and modulation of NF-kappa B pathway were measured. Male HUVECs have decreased survival, greater oxidative stress and impairment in angiogenesis compared to similarly exposed female cells. There is differential expression of VEGFR2 between male and female HUVECs and greater activation of the NF-kappa B pathway in female HUVECs under hyperoxic conditions. The results indicate that sex differences exist between male and female HUVECs in vitro after hyperoxia exposure. Since endothelial dysfunction has a major role in the pathogenesis of BPD, these differences could explain in part the mechanisms behind sex-specific differences in the incidence of this disease.

Oxysterol-binding protein (OSBP) is a cholesterol/PI4P exchanger at contacts of the endoplasmic reticulum (ER) with trans-Golgi network (TGN) and endosomes. Several central endothelial cell (EC) functions depend on adequate cholesterol distribution in cellular membranes. Here we elucidated the effects of pharmacologic OSBP inhibition on the lipidome and transcriptome of human umbilical vein endothelial cells (HUVECs). OSBP was inhibited for 24 h with 25 nM Schweinfurthin G (SWG) or Orsaponin (OSW-1), followed by analyses of cellular cholesterol, 27-hydroxy-cholesterol, and triacylglycerol concentration, phosphatidylserine synthesis rate, the lipidome, as well as lipid droplet staining and western analysis of OSBP protein. Next-generation RNA sequencing of the SWG-treated and control HUVECs and angiogenesis assays were performed. Protein-normalized lipidomes of the inhibitor-treated cells revealed decreases in glycerophospholipids, the most pronounced effect being on phosphatidylserines and the rate of their synthesis, as well as increases in cholesteryl esters, triacylglycerols and lipid droplet number. Transcriptome analysis of SWG-treated cells suggested ER stress responses apparently caused by disturbed cholesterol exit from the ER, as indicated by suppression of cholesterol biosynthetic genes. OSBP was associated with the TGN in the absence of inhibitors and disappeared therefrom in inhibitor-treated cells in a time-dependent manner, coinciding with OSBP reduction on western blots. Prolonged treatment with SWG or OSW-1 inhibited angiogenesis in vitro. To conclude, inhibition of OSBP in primary endothelial cells induced multiple effects on the lipidome, transcriptome changes suggesting ER stress, and disruption of in vitro angiogenic capacity. Thus, OSBP is a crucial regulator of EC lipid homeostasis and angiogenic capacity.

BACKGROUND Although the peroxisome proliferator-activated receptor-g (PPARg) agonist rosiglitazone has significant anti-inflammatory properties, no scientific studies have provided new insights in its pharmacological properties with respect to acute respiratory distress syndrome (ARDS). The present investigation aimed to evaluate whether rosiglitazone can reduce apoptosis and inflammation in a lipopolysaccharide (LPS)-induced acute respiratory distress syndrome in vitro model. MATERIAL AND METHODS Human umbilical vein endothelial cells (HUVECs) were treated with 1 µg/ml LPS in the absence or presence of 10 µM rosiglitazone for 24 h. Cell viability was measured by MTT assay. Flow cytometry was used to examine the cell apoptosis and ROS production in HUVECs response to LPS and rosiglitazone. The levels of pro-inflammatory cytokine factors, including TNF-α, IL-6, CXCL12, and CXCR4, were measured by ELISA, real-time PCR, and Western blot assay, respectively. The expression of PPARg, Bcl-2, and Bax and the activity of JAK2 and STAT3 were also investigated by Western blot assay. RESULTS We found that rosiglitazone significantly inhibited LPS-induced cell apoptosis, ROS production, and inflammation in HUVECs. Furthermore, we found a significant reduction of JAK2/STAT3 activation and the Bax/Bcl-2 ratio in LPS-induced HUVECs response to rosiglitazone treatment. CONCLUSIONS Treatment with rosiglitazone can reduce apoptosis and inflammation in HUVECs induced by LPS.

To explore the possible role of miR-499a-3p in the function of primary human umbilical vein endothelial cells (HUVECs) and the expression of ADAM10 in primary HUVEC.

We aimed to determine the toxic effects of tritiated water (HTO) on 12 generations (T1-T12) of human umbilical vein vascular endothelial cells (HUVECs) and elucidate the underlying mechanisms. We evaluated cellular senescence, interleukin (IL) 8 concentrations, and angiogenesis using β-galactosidase staining, enzyme-linked immunosorbent assay, and in vitro assays, respectively. The adhesion properties of contaminated cells and differentially expressed genes were assessed using the xCELLigence RTCA SP system and gene chip analysis, respectively. We found that long-term exposure to low levels of HTO can reduce the adhesion of HUVECs to the cellular matrix as well as their angiogenic capacity, while increasing their permeability, senescence, and adhesion to monocytes. Interleukin 8 activated the p38 and Epidermal Growth Factor Receptor (EGFR) pathways in HTO-treated cells and hence was identified as a key candidate of biomarker. The present study clarified the toxicity of HTO in vascular endothelial cells and identified IL8 as a novel protective target with important theoretical and practical values.

Compounds with anti-angiogenic properties are useful in combating cancer by preventing new blood vessel formation to support the tumor. In this report we introduce a rapid method for screening potential anti-angiogenic compounds in a model system that stimulates the production of secondary defense chemicals in plants. This methodology identified an inducible vascular factor (IVF3), which was found to be inhibitory in all of the model systems tested. Thyme plants were exposed to highly vascular mint plants and the methanol extracts were analyzed by reverse phase HPLC. The thyme compounds induced by the invading mint tissue, and not present in the thyme plants grown alone, were tested in a vertical plate assay measuring root length as a quantitative assay for drug sensitivity. The HPLC-purified extract, referred to as IVF3, reduced the growth of root vascular tissue compared to the control and vehicle control, and 50% as well as known angiogenesis inhibitors, VEGF receptor tyrosine kinase inhibitor and amiloride hydrochloride. Extracted compounds that were effective inhibitors of plant roots were assayed in Madin Darby canine kidney epithelial cells (MDCK) for toxicity, and in human umbilical vein endothelial cells (HUVEC) for their effect on migration. IVF3 was effective at limiting HUVEC migration in VEGF-stimulated cultures. In vivo video capture of intersegmental vessel circulation between 48 and 72 h post fertilization in the developing vasculature of zebrafish embryos showed IVF3 also significantly reduced ISV functional circulation. This report demonstrates the anti-angiogenic effects of IVF3 extract in endothelial cells and in an intact vertebrate model for angiogenesis.

Vitronectin (VN) is a multi-functional protein involved in extracellular matrix (ECM)-cell binding through integrin receptors on the cell surface, which is an important environmental process for maintaining biological homeostasis. We investigated how VN affects the survival of endothelial cells after radiation damage. VN attenuated radiation-induced expression of p21, an inhibitor of cell cycle progression, and selectively inhibited Erk- and p38 MAPK-dependent p21 induction after radiation exposure through regulation of the activity of GSK-3β. VN also reduced the cleavage of caspase-3, thereby inhibiting radiation-induced apoptotic cell death. These results suggest that VN has important roles in cell survival after radiation damage.

Hyperglycemia could induce oxidative stress, activate transcription factor nuclear factor kappa B (NF-κB), up-regulate expression of endothelial adhesion molecules, and lead to endothelial injury. Studies have indicated that propofol could attenuate oxidative stress and suppress NF-κB activation in some situations. In the present study, we examined whether and how propofol improved high glucose-induced up-regulation of endothelial adhesion molecules in human umbilical vein endothelial cells (HUVECs).

Nuclear factor kappa B (NF-κB) has been implicated in anesthetic preconditioning (APC) induced protection against anoxia and reoxygenation (A/R) injury. The authors hypothesized that desflurane preconditioning would induce NF-κB oscillation and prevent endothelial cells apoptosis.

(1) Background: Perfluorooctane sulfonate (PFOS) is a persistent organic pollutant, and it is receiving increasing attention regarding its human health risks due to its extensive use. Endothelial dysfunction is a mark of cardiovascular disease, but the basic mechanism of PFOS-induced endothelial dysfunction is still not fully understood. Ferroptosis is a newly defined regulatory cell death driven by cellular metabolism and iron-dependent lipid peroxidation. Although ferroptosis has been shown to be involved in the pathogenesis of cardiovascular diseases, the involvement of ferroptosis in the pathogenesis of endothelial dysfunction caused by PFOS remains unclear. (2) Purpose: To explore the role of ferroptosis in the dysfunction of endothelial cells and underlying mechanisms. (3) Methods: Human umbilical vein endothelial cells (HUVECs) were exposed to PFOS or PFOS and Fer-1. The viability, morphology change under electronic microscope, lipid-reactive oxygen species (lipid-ROS), and production of nitric oxide (NO) were determined. The expression of glutathione peroxidase 4(GPX4), ferritin heavy chain protein 1 (FTH1), heme oxygenase 1 (HO-1) and Acyl-CoA synthetase long-chain family member 4 (ACSL4) were analyzed via Western blot analysis. (4) Results: PFOS was shown to cause a decrease in viability and morphological changes of mitochondria, and well as an increase in lipid droplets. The expression of GPX4, FTH1 and HO-1 was decreased, and that of ACSL4 was increased after exposure to PFOS. In addition to the above-mentioned ferroptosis-related manifestations, there was also a reduction in NO content. (5) Conclusions: PFOS induces ferroptosis by regulating the GPX4 and ACSL4 pathways, which leads to HUVEC dysfunction.

As an evolutionarily conserved metabolic process, autophagy is involved in the process of atherosclerosis (AS). MicroRNA-155 (miR-155), a multifunctional miRNA, plays an important role in many physiological and pathological conditions, including AS and autophagy. However, the effect of miR-155 on the regulation of autophagy in endothelial cells has not been reported to date. Therefore, the objective of our study was to investigate the role of miR-155 in autophagy induced by oxidized low-density lipoprotein (ox-LDL) in human umbilical vein endothelial cells (HUVECs). Our results demonstrated that ox-LDL induced autophagy in HUVECs and increased the expression of miR-155 significantly. Overexpression of miR-155 improved autophagic activity, whereas low expression of miR-155 inhibited autophagic activity. Therefore, the data demonstrated that miR-155 has a modulating effect on the autophagy of vascular endothelial cells.

The influence of 1-deoxynojirimycin (DNJ) derived from mulberry on senescence of endothelial cells was examined with the goal of discovery of a method for prevention of senescence of blood vessels. The effect of DNJ on senescence of human umbilical vein endothelial cells (HUVECs) promoted under high glucose condition was determined. HUVECs were cultured in normal glucose (5.6mmol/L, NG group), normal glucose plus DNJ (10μmol/L, DNJ group), high glucose (30mmol/L, HG group), or high glucose plus DNJ (10μmol/L, HG+DNJ group) and passaged until they reached senescence. The proliferation rate was markedly decreased in the HG group compared with the NG group, and this phenomenon was reversed by DNJ. The frequency of senescent (SA-ß-Gal-positive) cells and the expression level of senescence genes (PAI-1 and p21) were significantly higher in the HG group compared with the NG group, and these changes were blocked by DNJ. Monocyte adhesion, NF-kB activity, and reactive oxygen species production, all of which promote cellular senescence, were significantly increased in the HG group compared with the NG group, and again these changes were blocked by DNJ. Therefore, these results show that DNJ delays cellular senescence that is promoted under high glucose condition.

As angiogenesis plays important roles in tumor growth and metastasis, searching for antiangiogenic compounds is a promising tactic for treating cancers. Cafestol, a diterpene found mainly in unfiltered coffee, provides benefit through varied biological activity, including antitumorigenic, antioxidative, and anti-inflammatory effects. This study aimed to investigate the effects of cafestol on angiogenesis and to uncover the associated mechanism. We show that cafestol inhibits angiogenesis of human umbilical vascular endothelial cells. This inhibition affects the following specific steps of the angiogenic process: proliferation, migration, and tube formation. The inhibitory effects of cafestol are accompanied by decreasing phosphorylation of FAK and Akt and by a decrease in nitric oxide production. Overall, cafestol inhibits angiogenesis by affecting the angiogenic signaling pathway.

Kinase non-catalytic C-lobe domain containing 1 (KNDC1) exists in dendrites, guanine nucleotide exchange factor complexes and neuronal cell bodies as a putative protein‑protein interaction module that regulates a number of signaling pathways. Previous studies have demonstrated that the knockdown of KNDC1 delays human umbilical vein endothelial cell (HUVEC) senescence. However, the effect of KNDC1 overexpression on HUVEC function remains unclear. In the present study, an adenovirus vector carrying KNDC1 was constructed and then transfected into endothelial cells to observe cell senescence. Furthermore, the effect of KNDC1 overexpression on HUVEC senescence was investigated in vitro and the underlying molecular mechanism was investigated. Senescence‑associated β‑galactosidase staining was used to determine cellular senescence and reactive oxygen species (ROS) were monitored to detect the level of cell oxidative stress. The mRNA transcription level and protein expression were analyzed by reverse transcription‑quantitative polymerase chain reaction and western blot analysis, respectively. The results demonstrated that KNDC1 overexpression possibly inhibited HUVEC activity and function and promoted HUVEC senescence. Mechanistic studies demonstrated that KNDC1 triggered a p53‑ROS positive feedback loop, which serves a crucial role in regulating senescence. In conclusion, to the best of the authors' knowledge, this is the first time that KNDC1‑adenovirus vector inhibition of HUVEC proliferation by activating the p53 signaling pathway has been reported. Theoretically, the results of the present study also support KNDC1 as a therapeutic target for future anti-senescence.

Sialic acids represent common terminal residues on numerous mammalian glycoconjugates, thereby influencing e.g. lumen formation in developing blood vessels. Interestingly, besides monosialylated also polysialylated glycoconjugates are produced by endothelial cells. Polysialic acid (polySia) is formed in several organs during embryonal and postnatal development influencing, for instance, cell migration processes. Furthermore, the function of cytokines like basic fibroblast growth factor (bFGF) is modulated by polySia.

Magnesium sulfate (MgSO4) is utilized for fetal neuroprotection in preterm birth but its mechanism of action is still poorly understood. P2X7 receptor (P2X7R) is required for secretion of IL-1β, and can be blocked by divalent cations such as magnesium (Mg) and its own antagonist, Brilliant Blue G (BBG). We sought to determine whether during inflammation MgSO4 can block endothelial IL-1β secretion, using an in-vitro model.