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

Pingyangmycin (bleomycin A5 hydrochloride, PYM) is one of the anti-neoplastic agents which have been commonly used to treat venous malformations. However, the underlying mechanism by which PYM treats venous malformations remains poorly understood. It was reported that venous endothelial cells could recruit neutrophils via adhesion molecules (E-selectin, ICAM-1, ICAM-3, VCAM-1) during the acute/chronic inflammation and subsequent histological fibrosis after sclerotherapy with PYM. This study explored if the expression of E-selectin, ICAM-1, ICAM-3 and VCAM-1 in human venous malformation endothelial cells could be affected by PYM. HVMECs were cultured from human venous malformation tissue. Expressions of E-selectin, ICAM-1, ICAM-3 and VCAM-1 on HVMECs in response to PYM were analyzed by cell ELISA. The relative levels of mRNA expression in the cells were semi-quantified. The results showed that PYM up-regulated the expressions of E-selectin, ICAM-3, VCAM-1 and ICAM-1 in both time- and concentration-dependent manner. Our findings suggested that PYM could induce the expression of adhesion molecules in HVMECs, which might be a possible mechanism by which sclerotherapy by intralesional injection of PYM treats venous malformations.
Bleomycin ; analogs & derivatives ; pharmacology ; Cell Adhesion Molecules ; genetics ; metabolism ; Cells, Cultured ; Endothelial Cells ; drug effects ; metabolism ; Endothelium, Vascular ; drug effects ; metabolism ; Gene Expression ; drug effects ; genetics ; Humans

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

OBJECTIVETo examine the effect of cinobufacini on rat thoracic aorta and its mechanism.

METHODSIsolated rat thoracic aorta was perfused and isometric tension was recorded by organ bath technique before and after cinobufacini treatment.

RESULTCinobufacini induced contraction of isolated thoracic aorta with or without endothelium in a concentration-dependent manner (at concentration of 2.5,5.0,7.5,10.0 g/L). The vasoconstriction effect of cinobufacini was more potent in endothelium-denuded aorta ring [(16.3+/-3.39)%, (52.5+/-7.70)%, (60.9+/-8.84)%, (69.2+/-11.34)%] than in endothelium-intact aorta ring [(6.2+/-2.07)%, (14.7+/-4.91), (17.6+/-5.86)%, (20.3+/-6.78)% (P<0.01)]. Its contractile effect was attenuated in Ca(2+)-free solution (about 1/10 of that in buffer with 1.25 mmol/L CaCl(2)) or by the treatment with verapamil (10(-7)mol/L), an L-type calcium channel antagonist. Cinobufacini induced contraction on the endothelium-intact rat aorta was augmented by pretreatment with L-NAME (10(-4)mol/L), a nitric oxide synthase inhibitor.

CONCLUSIONCinobufacini contracts rat thoracic aorta by opening the voltage-dependent Ca(2+) channel and increasing Ca(2+) influx into vascular smooth muscle. Cinobufacini can also stimulate the release of vascular relaxant factor, nitric oxide, from the endothelium and thus antagonize cinobufacini-induced contraction.

Animals ; Aorta, Thoracic ; drug effects ; Bufanolides ; pharmacology ; Endothelium, Vascular ; drug effects ; metabolism ; In Vitro Techniques ; Male ; Nitric Oxide ; biosynthesis ; Rats ; Rats, Sprague-Dawley ; Vasoconstriction ; drug effects ; Vasoconstrictor Agents ; pharmacology

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 observe the protective effect of metformin on the endothelial function and the mechanisms in rats with low-density lipoprotein (LDL) injection.

METHODSA single dose (4 mg/kg) of natural LDL was injected through the sublingual vein of rats to induce vascular endothelial dysfunction. Blood samples were then collected from the rats to detect the concentrations of malondialdehyde (MDA) and nitric oxide (NO), activity of superoxide dismutase (SOD) and serum lipid levels. The thoracic aorta of rats was obtained to assay acetylcholine (ACh)-induced endothelium-dependent relaxation (EDR) and sodium nitroprusside (SNP)-induced endothelium-independent relaxation. The effects of metformin pretreatment on the endothelial functions in the rats were investigated.

RESULTSA single-dose LDL significantly inhibited ACh-induced EDR without affecting SNP-induced endothelial-independent relaxation. The injection decreased serum NO and elevated serum MDA level, but had no effect on serum lipid level. Metformin markedly attenuated LDL-induced inhibition of EDR, serum MDA elevation, and serum NO reduction without affecting the serum lipid levels.

CONCLUSIONMetformin provides protection against vascular endothelial dysfunction induced by LDL in rats, the mechanism of which is probably associated with protection of endothelium-dependent relaxation factor and inhibition of the oxidative stress.

Animals ; Endothelium, Vascular ; drug effects ; physiopathology ; Endothelium-Dependent Relaxing Factors ; metabolism ; Lipoproteins, LDL ; administration & dosage ; Male ; Malondialdehyde ; blood ; Metformin ; pharmacology ; Nitric Oxide ; blood ; Oxidative Stress ; drug effects ; Rats ; Rats, Sprague-Dawley ; Superoxide Dismutase ; metabolism ; Vasodilation ; drug effects ; physiology

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

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

To investigate the effects and potential mechanisms of hyperoside (Hyp) on the vascular endothelium function in middle cerebral artery (MCA) ex vivo in rats. Isolated arterial segments from MCAs of rats were used for surveying vasomotoricity in a pressurized chamber. Transmembrane potential was recorded by using glass microelectrodes to evaluate hyperpolarization. Hyp (1 x 10(-6)-1 x 10(-4) mol . L-1) was utilized to observe the effect on 1 x 10(-7) mol . L-1 U46619-preconstricted MCA in rats. The results showed that 1 x 10(-6)-1 x 10(-4) mol . L-1 Hyp significantly induced concentration-dependent vasodilatation and hyperpolarization, leading to the maximal diastolic ratio of (73. 2 ± 6. 1)% and maximal changes in membrane potentials of (-13. 2 ± 2. 2) mV. Hyp still elicited vasorelaxation and hyperpolarization by removal of endothelium in MCA of rat, which was notably attenuated as compared with vascular endothelium-intact group (P <0. 01). In the MCAs preconstricted by U46619 (1 x 10(-7) mol . L-1), Hyp (1 x 10(-6)-1 x 10(-4) mol . L-1) produced concentration-dependent vasorelaxation and hyperpolarizition that were partially attenuated by 3 x 10(-5) mol . L-1 L-NAME(a NOS inhibitor) plus 1 x 10(-5) mol . L-1 PGI2 ,(a synthetase inhibitor). The residual effects were further decreased by 1 x 10(-3) mol . L-1 TEA (an inhibitor of Ca2+-activated potassium channel) or 1 x 10(-5) mol . L-1 PPG (a blocker of endogenous H2S synthese-CSE). Similarly, 1 x 10(-5)-1 x 10(-3) mol . L-1 NaHS (a donor of exogenous H2S) or 1 x 10(-5)-1 x 10(-3) mol . L-1 L-Cys (the substrate of endogenous H2S synthesis) obviously evoked dose-dependent vasodilatation and hyperpolarization of MCA in rats. These findings indicated that Hyp may induce endothelium-dependent and endothelium-independent responses. And the endothelium-dependent vasodilatation may be related to the increases of endogenous H2S that has been promoted Hyp in the endotheliocyte of MCAs, and activated Kca and opening of Kca channels, resulting in the hyperpolarization of vascular smooth muscle cell membrane and subsequent reduction of Ca2+ influx and vasodilation.
Animals ; Endothelium, Vascular ; drug effects ; Enzyme Inhibitors ; pharmacology ; Female ; Male ; Middle Cerebral Artery ; Muscle, Smooth, Vascular ; drug effects ; Nitric Oxide ; metabolism ; Potassium Channels ; metabolism ; Quercetin ; analogs & derivatives ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Sulfides ; metabolism ; Vasodilation ; drug effects ; Vasodilator Agents ; pharmacology

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