Oxidized low density lipoprotein (oxLDL) can trigger intracellular production of reactive oxygen species and lipid peroxidation (LPO), and is thought to contribute to initiation and progression of atherosclerosis. In order to understand the correlation between oxLDL and macromolecular damage, we measured levels of LPO-derived miscoding etheno-DNA adducts and LPO-modified proteins in cultured human vascular endothelial and smooth muscle cells after incubation with oxLDL for up to 48 h. A semi-quantative analysis method for 1, N6-ethenodeoxyadenosine (ɛdA) by immunohistochemistry was applied. After oxLDL stimulation, ɛdA-stained nuclei were significantly increased in both endothelial and smooth muscle cells. Similarly, 4-hydroxy-2-nonenal (4-HNE)-modified proteins, as analyzed by immunohistochemistry and Western blotting, were also 3-5 fold increased. It was concluded LPO-derived etheno-DNA adducts and LPO-modified proteins are strongly induced by oxLDL in human vascular endothelial and smooth muscle cells. This macromolecular damage may contribute to the dysfunction of arterial endothelium and the onset of atherosclerosis.
DNA ; metabolism ; Endothelium, Vascular ; cytology ; drug effects ; metabolism ; Humans ; Lipid Peroxidation ; drug effects ; Lipoproteins, LDL ; pharmacology ; Muscle, Smooth ; cytology ; drug effects ; metabolism ; Proteins ; metabolism

Cells, Cultured ; Endothelial Cells ; drug effects ; metabolism ; Endothelium, Vascular ; cytology ; metabolism ; Gene Expression Profiling ; Humans ; Ouabain ; pharmacology ; Umbilical Veins ; cytology

Extensive monocyte recruitment is an early phenomenon associated with the development of atherosclerotic lesion. Although the molecular mechanisms are not completely understood, monocyte recruitment into these early lesions may involve changes in endothelial adhesion for monocyte, in which adhesion molecules expressed by endothelial cell play an active role. In vivo, the function of endothelial cells is not only affected by the chemical factors, but also by the mechanical factors. The purpose of this article was to investigate the induction of adhesion molecules expression by synergistic effects of Lysophosphatidylcholine (Lyso-PC) and shear stress in cultured human umbilical vein endothelial cells (HUVEC). The surface expression of ICAM-1, VCAM-1 and E-selectin on HUVEC induced by Lyso-PC(30 micrograms/ml) and shear stress(2.23, 4.20 dyne/cm2) were analyzed using flow cytometry. The results showed that: Compared with what were simultaneously exposed to shear stress and Lyso-PC, activating the cells with Lyso-PC prior to shear stress, or pre-conditioning the cells exposed shear stress prior to Lyso-PC incubation, a significantly higher expression of ICAM-1 and VCAM-1(P < 0.05) was resulted. HUVEC were exposed to shear stress and Lyso-PC at the same time or treated with each agonist alone, E-selectin expression was not significantly different from the control group. However, a sequential action of the two stimuli significantly increased E-selectin expression(P < 0.05). We concluded that: a sequential action of the shear stress and Lyso-PC induced an even greater expression of ICAM-1 and VCAM-1, thus it could be understood that the flows-hear stress in combination with endothelial activated by chemical factors may increase the ability of endothelial cells to recruit leukocytes even under the mechanical environment unfavorable for cell adhesion.
Cell Adhesion Molecules ; biosynthesis ; Cells, Cultured ; Endothelium, Vascular ; cytology ; drug effects ; metabolism ; Humans ; Lysophosphatidylcholines ; pharmacology ; Stress, Mechanical ; Umbilical Veins ; cytology

OBJECTIVETo investigate the effects of simvastatin on vascular cell adhesion molecule-1 (VCAM-1) expression and adhesive function in ECV-304 cells treated with CD40L.

METHODSHuman umbilical vein endothelial cell (HUVEC) was cultured and treated with various concentrations CD40L alone or in combination with various concentrations simvastatin in the absence or presence of mevalonic acid (400 micromol/L). RT-PCR and FCM analysis were used to determine VCAM-1 expression and lymphocytes adhesion to endothelial cells.

RESULTSSimvastatin (0 - 10 micromol/L) decreased in a concentration-dependent manner the expression of VCAM-1 induced by CD40L and this effect could be blocked by cotreatment with mevalonic acid. Moreover, Simvastatin also significantly decreased adhesion capacity of lymphocytes to endothelial cells induced by CD40L.

CONCLUSIONSimvastatin downregulates VCAM-1 expression and adhesive capacity of lymphocytes to endothelial cells induced by CD40L.

CD40 Ligand ; metabolism ; Cell Adhesion ; Cells, Cultured ; Endothelium ; drug effects ; metabolism ; Endothelium, Vascular ; cytology ; Humans ; RNA, Messenger ; metabolism ; Simvastatin ; pharmacology ; Umbilical Veins ; cytology ; Vascular Cell Adhesion Molecule-1 ; metabolism

OBJECTIVEThe present study was designed to investigate whether Tumor necrosis factor (TNF)-alpha stimulates release of endothelial microparticles (EMPs) by human endothelial cells, and whether EMPs may serve as a promising marker for endothelial injury and dysfunction.

METHODSHuman umbilical venous endothelial cells (HUVEC) were incubated with or without TNF-alpha for 24 hours at 37 degrees C. EMPs generated on the surface of HUVEC were observed with a scanning electron microscopy. The CD31 and CD51 positive EMPs in culture supernatants were measured by flow cytometer.

RESULTSFewer vesicles were observed on cell surface of control group, in TNF-alpha-stimulated one, however, cells manifested a blebby surface (eruption phenomenon) and more vesicles on surface were observed. The levels of EMPs were significantly increased in TNF-alpha stimulated cells compared with controls [CD31 + EMP, (164 +/- 63)/1000 cells vs. (42 +/- 10)/1000 cells, P < 0.05; CD51 + EMP, (260 +/- 108)/1000 cells vs. (19 +/- 4)/1000 cells, P < 0.05].

CONCLUSIONTNF-alpha can stimulate HUVEC to release EMPs which may serve as a surrogate marker for endothelial injury and dysfunction.

Cells, Cultured ; Cytoplasmic Granules ; metabolism ; Endothelial Cells ; drug effects ; metabolism ; Endothelium, Vascular ; cytology ; Flow Cytometry ; Humans ; Tumor Necrosis Factor-alpha ; metabolism ; pharmacology ; Umbilical Veins ; cytology

Antioxidants ; pharmacology ; Ascorbic Acid ; pharmacology ; Carbon Disulfide ; adverse effects ; antagonists & inhibitors ; Cells, Cultured ; Endothelium, Vascular ; drug effects ; Humans ; Umbilical Veins ; cytology ; drug effects ; metabolism

AIMTo investigate the role of TNF-alpha in vascular endothelial cells injury mediated by freezing/thaw ing PMN.

METHODSFreezing/thawing cell model was founded using rat PMN isolated by dextran sedimentation technique and VEC cultured in vitro. The injury level of VEC was indicated by measuring activity of LDH in medium. The number of frozen/thawed PMN adhering to VEC was counted with Phagocytizing reactive dyes the degree of frozen/thawed PMN and VEC adhesion. Expression of LFA-1 on the surface of frozen/thawed PMN was analyzed with flow cytometry.

RESULTSTNF-alpha could obviously upregulate expression of LFA-1 on surfaced of frozen/thawed PMN. Upregulation of LFA-1 expression promoted adhesion of frozen/thawed PMN and normal VEC,and aggravated VEC injury. Monoclonal antibody against LFA-1 could partly block adhesion of frozen/thawed PMN and normal VEC,and attenuate VEC injury.

CONCLUSIONTNF-alpha can promote expression of LFA-1 on surface of frozen/thawed PMN adhering of frozen/thawed PMN to normal VEC and VEC injury increase, monoclonal antibody against LFA-1 could partly block PMN-VEC adhesion and attenuate VEC injury.

Animals ; Cell Adhesion ; Cells, Cultured ; Endothelial Cells ; drug effects ; Endothelium, Vascular ; cytology ; Freezing ; Lymphocyte Function-Associated Antigen-1 ; metabolism ; Neutrophils ; cytology ; metabolism ; Rats ; Tumor Necrosis Factor-alpha ; pharmacology

OBJECTIVEVerotoxin-producing Escherichia coli (VTEC) strains of serotype O157 : H7 have been implicated in a wide spectrum of diseases, including blood diarrhea, hemorrhagic colitis and hemolytic uremic syndrome (HUS). To further explore the pathological role of verotoxin (VT) in HUS and other VTEC associated diseases, we investigated the effects of recombinant verotoxin 2 (rVT2) on the biological activity of neutrophils.

METHODSThe technique of flow cytometry, a fluorescent probe 2,7-bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein acetoxymethyl ester (BCECF/AM), and the assay of reduced cytochrome c to detect superoxide production were used in this study.

RESULTSgammaVT2 significantly inhibited spontaneous apoptosis in neutrophils. Neutrophils with prolonged survival due to gammaVT2 maintained various biological functions, such as the expression of adhesion molecules (shading CD62L and raising CD11b/CD18), adherence to human umbilical vein endothelial cells (HUVECs), and generation of superoxide (O(2)(-)).

CONCLUSIONProlongation of the functional life-span of neutrophils by gammaVT2 may accelerate inflammatory responses at sites of inflammation. This may play a crucial role in neutrophil-mediated tissue injury in HUS and other VTEC-associated diseases.

Apoptosis ; drug effects ; Cell Adhesion ; Endothelium, Vascular ; cytology ; Humans ; Neutrophils ; drug effects ; physiology ; Recombinant Proteins ; toxicity ; Shiga Toxin 2 ; toxicity ; Superoxides ; metabolism

AIMTo observe the effect of quercetin (Que) on the adhesion of platelets to cultured endothelial cells and adhesion molecule expression by human umbilical vein endothelial cells (HUVEC) and platelets.

METHODS[3H]-Adenine labeled platelets were incubated with HUVEC to investigate the effect of Que on adhesion of platelets to HUVEC. The number of platelets adhering to the HUVEC monolayer was determined by liquid scintillation spectroscopy. TNF-alpha induced HUVEC expression ICAM-1 and thrombin induced platelets expression of P-selectin were measured by flow cytometry.

RESULTSQue (0.3-2.4 mumol.L-1) was shown to inhibit the increase of P-selectin expression of thrombin activated platelets. Pretreatment of HUVEC with tumor necrosis factor (TNF-alpha) significantly increased platelets adhesion to HUVEC and the expression ICAM-1. Que (0.6-2.4 mumol.L-1) inhibited this effect of TNF-alpha in a concentration-dependent manner.

CONCLUSIONQue can inhibit the adhesion of platelets to HUVEC and the expression of adhesion molecules (P-selectin and ICAM-1).

Blood Platelets ; drug effects ; metabolism ; Cell Adhesion ; drug effects ; Cells, Cultured ; Endothelium, Vascular ; drug effects ; metabolism ; Gene Expression ; drug effects ; Humans ; Intercellular Adhesion Molecule-1 ; metabolism ; P-Selectin ; metabolism ; Quercetin ; pharmacology ; Umbilical Veins ; cytology

Thrombospondin-1 (TSP-1), a multifunctional extracellular matrix protein, inhibits neovascularization and is implicated in the regression of tumor growth and metastasis. We found that the synthesis of TSP-1 in porcine aortic endothelial (PAE) cells was decreased in a dose-dependent manner by phorbol 12-myristate 13-acetate (PMA) treatment in porcine aortic endothelial (PAE) cells. In this study, a responsive site on the TSP-1 promotor affected by PMA treatment in PAE was characterized. The level of TSP-1 mRNA was also decreased by PMA after 1 h and persisted that way for at least 24 h. PMA treatment and c-Jun overexpression suppressed the transcription of TSP-1 promotor-luciferase reporter gene. A deletion between -767 and -657 on the TSP-1 promotor neutralized the PMA-induced down-regulation. In addition, oligo a (-767 approximately -723) was responsive to PMA-induced repression, while oligo b (-734 approximately -689) and c (-700 approximately -656) was not. Electrophoretic mobility shift assays showed that this PMA responsive element specifically bound a nuclear protein and that the binding activity was diminished by PMA treatment in PAE cells but not in Hep 3B cells. In supershift assay, potential regulatory elements in this region, SP1 and GATA-1, were not responsive to the inhibition of TSP-1 expression by PMA. Our results suggest that the repression of TSP-1 synthesis by PMA is mediated by blocking a particular unknown nuclear protein binding to the responsive site (-767 approximately -735), which is regulated by c-Jun.
Animal ; Aorta/cytology ; Cell Line ; Down-Regulation (Physiology) ; Endothelium, Vascular/drug effects* ; Endothelium, Vascular/cytology ; Promoter Regions (Genetics)* ; Proto-Oncogene Proteins c-jun/metabolism ; Response Elements* ; Swine ; Tetradecanoylphorbol Acetate/pharmacology* ; Thrombospondin 1/genetics* ; Thrombospondin 1/biosynthesis