To explore the changes of wall shear stress(WSS) effect on arterial endothelial cell(EC) apoptosis after reducing arterial blood flow. The reducing flow model was established in 60 rabbits. Endothelial stretched preparations were made at 8 different time intervals from 0 to 30 days. The apoptosis rate of arterial endothelial cells (AEC) was measured with TdT-mediated dUTP-biotin nick end labeling(TUNEL) method. The results showed that the apoptosis rate of AEC was significantly higher from 1 day to 7 days after decreasing WSS than that of control, which peaked on day 3. While with progressively increasing in WSS, the apoptosis rate restored to the level of control from 14 days to 30 days. These suggest that the apoptosis state of AEC might be markedly influenced by the changes of WSS. The persist decreasing of WSS may be the important factor which induces the cell apoptosis.
Animals ; Apoptosis ; Arteries ; cytology ; physiology ; Endothelium, Vascular ; cytology ; physiology ; Male ; Rabbits ; Regional Blood Flow ; Shear Strength

The coupling between the endothelium and blood flow is an important biomedical problem and has drawn extensive research. Endothelial cells are known to adapt their shapes and functions in response to applied shear flow. Shear Stress being regarded as a primary triggering signal for cellular remodeling, it is important to understand the interaction mechanism between applied shear flow and endothelial cells. In present study we have established a theoretical model to simulate the coupling between the deformation of an endothelial cell and applied shear flow. A two dimensional computational fluid dynamic (CFD) is conducted to determine the local distributions of mechanical stress and pressure on cell surface. Our results show that: (1) the deformation of endothelial cell changes with alpha (corresponding to the shear stress imposed on cell surface by flow fluid). When alpha is greater than 0.021, the cell deformability increases greatly; (2) the distributions of stress and pressure on cell surface are not uniform, but the maximal shear stress and displacement are always at the top point of the cell. Meanwhile, we have measured the deformation of cultured human aortic endothelial cells (HAECs) exposed to shear flow by using a flow chamber. We found that the numerical results are well consistent with those of experiment. These results suggest that the non-uniformity distributions of mechanical stress and pressure on cell surface may play a particular role in the mechanism of cell activation and in the regulation of endothelial cells functions (modification of cytoskeleton, distributions of adhesion molecules, etc.). The present study offers a framework to facilitate the development of a comprehensive dynamic model for endothelial cells.
Aorta ; cytology ; Cells, Cultured ; Endothelium, Vascular ; cytology ; physiology ; Humans ; Models, Cardiovascular ; Stress, Mechanical

Antiendothelial cell antibodies (AECA) have been detected in the sera of patients of autoimmune diseases showing vasculitis. Using IgM-ELISA, we found AECA in 42 (56%) of 75 sera samples from patients with Behcet's disease in a previous study. All of the 15 AECA-positive sera of Behcet's disease patients had an increased expression of the intercellular cell adhesion molecule-1 (ICAM-1), 93.3% of the sera induced the vascular cell adhesion molecule-1 (VCAM-1), and 100% of the serum induced the E-selectin molecule on human dermal microvascular endothelial cells (HDMEC). After stimulation of HDMEC with AECA-positive sera of Behcet's disease patients, the expression of ICAM-1 and VCAM-1 on HDMEC increased significantly at 4 hours, reaching a peak at 16 hours. Expression of E-selectin was induced at 1 hour after stimulation with a peak at 4 hours and it decreased thereafter. Adherence of T lymphocytes to HDMEC increased significantly after stimulation with AECA-positive sera from Behcet's disease patients. Also, the adherence of T lymphocytes to HDMEC increased at 4 hours and returned to its normal level at 48 hours. These results show that AECA-positive sera of Behcet's disease patients are capable of activating HDMEC to promote the adherence of T lymphocytes to increase the expression of ICAM-1, VCAM-1, and E-selectin on the cell surfaces. The whole process may play an important role in the pathogenesis of vasculitis in Behcet's disease.
Antibodies/physiology* ; Antibodies/blood ; Behcet's Syndrome/immunology ; Behcet's Syndrome/blood* ; Blood Physiology ; Cell Adhesion/physiology ; Cells, Cultured ; Endothelium, Vascular/physiology* ; Endothelium, Vascular/immunology* ; Endothelium, Vascular/cytology ; Human ; Microcirculation/physiology ; Skin/blood supply* ; T-Lymphocytes/physiology*

The non-random distribution of atherosclerosis was related to local hemodynamic environment. The stabilization of endothelium was important in this process. We studied the effect of magnitude of shear stress on proliferation of endothelial cells. It was shown the proliferation of endothelial cells was inhibited by shear stress, and was related to the magnitude of shear stress. A parallel plate sudden-expansion flow chamber was constructed, and the effect of flow pattern was also studied. It was shown the inhibition effect produced by shear stress was decreased in this chamber.
Animals ; Aorta ; cytology ; Cattle ; Cell Division ; physiology ; Cells, Cultured ; Endothelium, Vascular ; cytology ; physiology ; Models, Cardiovascular ; Stress, Mechanical

It is the infent of this study to establish a simple method for cultivation of rat pulmonary microvascular endothelial cells(PMVECs) and investigate the viscoelasticity of PMVECs. First, we obtained rat's peripheral pulmonary tissue, which then was cut into small pieces and cultured with 3 ml DMEM containing 20% bovine calf serum, 90 U/ml heparin, 4 mmol L-glutamine, 100 U/ml penicillin and 100 micrograms/ml streptomycin. Next, moved away the pulmonary tissue pieces 60 h later, and started passage 2-4 days after continued culture. Last, digested and separated PMVECs and studied viscoelastic coefficients of PMVECs by using micropipette aspiration technique. The results revealed that the cultured PMVECs showed regular cobblestone morphology and conformed with endothelial cells morphological characterization by phase contrast microscopy. PMVECs elastic modulus K1 was 49.3 +/- 9.2 Pa, K2 was 73.2 +/- 24.8 Pa, and it's viscosity factor mu was 19.2 +/- 7.2 Pa. s. These data demonstrate that it is feasible to cultivate PMVECs with tissue pieces method, and PMVECs is of greater rigidity.
Animals ; Cells, Cultured ; Elasticity ; Endothelium, Vascular ; cytology ; physiology ; Lung ; blood supply ; Male ; Rats ; Rats, Wistar ; Viscosity

Endothelial progenitor cells (EPCs) are immature endothelial cells which have the capacity to proliferate, migrate and differentiate into mature endothelial cells from bone marrow to the peripheral circulation. EPCs have been shown to participate in postnatal endothelial repair and neovascularization of ischemic organs, and have been used as a new source of seeded cells in vascular tissue engineering. In this review, we focus on the origin, identification, property and function of EPCs as well as their application in vascular tissue engineering.
Animals ; Blood Vessels ; physiopathology ; Endothelial Cells ; cytology ; physiology ; Endothelium, Vascular ; pathology ; physiology ; Humans ; Neovascularization, Physiologic ; physiology ; Recovery of Function ; physiology ; Stem Cells ; cytology ; physiology ; Tissue Engineering ; methods

In order to determine the precise mechanism of the interactions between different types of cells, which are common phenomena in tissues and organs, the importance of coculture techniques are becoming increasingly important. In the area of cardiology, artificial arteries have been developed, based on the understanding of physiological communication of the arterial smooth muscle cells (SMC), endothelial cells (EC), and the extracellular matrix (ECM). In the study of atherosclerosis, the modification of low-density lipoprotein (LDL), which result in the recruitment and accumulation of white blood cells, especially, monocytes/macrophages, and foam cell formation, are hypothesized. Although there are well known animal models, an in vitro model of atherogenesis with a precisely known atherogenesis mechanism has not yet been developed. In this paper, an arterial wall reconstruction model using rabbit primary cultivated aortic SMCs and ECs, was shown. In addition, human peripheral monocytes were used and the transmigration of monocytes was observed by scanning electron and laser confocal microscopy. Monocyte differentiation into macrophages was shown by immunohistochemistry and comprehensive gene expression analysis. With the modified form of LDL, the macrophages were observed to accumulate lipids with a foamy appearance and differentiate into the foam cells in the ECM between the ECs and SMCs in the area of our coculture model.
Animal ; Aorta/physiology* ; Aorta/cytology* ; Arteriosclerosis/etiology* ; Cell Differentiation/physiology ; Cell Movement ; Coculture ; Endothelium, Vascular/physiology ; Endothelium, Vascular/cytology ; Extracellular Matrix/metabolism ; Foam Cells/ultrastructure ; Foam Cells/cytology ; Macrophages/physiology* ; Macrophages/cytology ; Male ; Microscopy, Confocal ; Microscopy, Electron ; Microscopy, Electron, Scanning ; Monocytes/ultrastructure ; Monocytes/physiology ; Muscle, Smooth, Vascular/physiology ; Muscle, Smooth, Vascular/cytology ; Myosin/metabolism ; Protein Isoforms/metabolism ; Rabbits

To determine applicability of the cryopreservation procedure for vessel grafts, the viability of endothelial cells (ECs) among the whole cells in three kinds of organs artery, vein, trachea in mongrel dogs was evaluated on the basis of histological analysis. The Griffonia simplicifolia agglutins-fluorescein isothiocyanate (GSA-FITC) and propidium iodide (PI) double staining methods were combined with flow cytometry (FCM), which was able to simultaneously determine the viability of whole cells and ECs from the same tissue, were performed after harvesting, after antibiotic solution treatment, and after cryopreservation and thawing. In most cases, the viability of ECs is lower than that of whole cells from veins and arteries. The viability of whole cells in veins was maintained until the antibiotic solution treatment and then decreased significantly after cryopreservation and thawing, while the ECs began to decrease significantly after the antibiotic solution treatment and more markedly decreased after thawing. The viability of ECs and whole cells from arteries was similar to that of the veins' conditions. The viability of whole cells from the trachea decreased with a similar pattern to that of the ECs from vessels. In consideration of maintaining cell viability among the three kinds of organs, the viability of arteries was better than that of the others. The cells in the trachea demonstrated a lower viability than the vessels. The effect of antibiotic solution treatment on the reduction of cell viability depends on the treatment time and temperature.
Animalt ; Arteries/transplantation ; Cell Survival ; Coronary Vessels*/transplantatione ; Cryopreservation* ; Dogs ; Endothelium, Vascular/physiology* ; Endothelium, Vascular/cytology ; Female ; Male ; Trachea*/transplantation ; Middle Age ; Veins/transplantation

OBJECTIVETo compare the differences in nitric oxide (NO) release and endothelium-derived hyperpolarizing factor (EDHF)-mediated hyperpolarization between human radial artery (RA) and saphenous vein (SV) through direct measurement of NO and membrane potential.

METHODSRA (n = 8), SV (n = 23), and surgical prepared SV (PV, n = 9, dilatation with normal saline solution at a pressure of 100 - 600 mmHg, 1 mmHg = 0.133 kPa) segments (5 mm long) taken from patients undergoing coronary artery bypass grafting were placed in an organ chamber. The NO-sensitive electrode and intracellular glass microelectrode was used to directly measure the NO release and the membrane potential changes in response to acetylcholine (ACh) and bradykinin (BK) before and after incubation with NG-nitro-L-arginine, indomethacin, and oxyhemoglobin.

RESULTSThe basal release of NO in RA [(11.9 ± 1.8) nmol/L] was significantly greater than that in SV [(9.9 ± 2.8) nmol/L, P = 0.041]. BK-induced NO release in RA was lower than that in SV [for BK 10(-7) mol/L: (25.8 ± 3.6) nmol/L vs. (43.7 ± 8.2) nmol/L, P = 0.006]. Both basal and ACh- or BK-induced NO release in PV were significantly reduced [basal release: PV (3.4 ± 1.4) nmol/L; P = 0.006 vs. RA; P = 0.002 vs. SV; stimulated release: for ACh 10(-5) mol/L: PV (4.8 ± 3.2) nmol/L; vs. RA (28.6 ± 7.9) nmol/L, P = 0.005; vs. SV (27.4 ± 3.7) nmol/L, P = 0.003; for BK 10(-7) mol/L: PV (7.0 ± 3.6) nmol/L; vs. RA (25.8 ± 3.6) nmol/L, P = 0.016; vs. SV (43.7 ± 8.2) nmol/L, P = 0.004]. EDHF-mediated hyperpolarization was greater in RA than that in SV [ACh 10(-5) mol/L: (-9.7 ± 1.9) mV vs. (-4.5 ± 1.1) mV, n = 17, P = 0.002].

CONCLUSIONSRA is superior to SV in terms of NO basal release and EDHF-mediated endothelial function. Surgical preparation and pressure dilatation may severely impair the NO-mediated endothelial function of SV, which may contribute to the poor long-term patency of SV coronary graft.

Biological Factors ; metabolism ; Endothelial Cells ; metabolism ; physiology ; Endothelium, Vascular ; cytology ; metabolism ; Female ; Humans ; Male ; Membrane Potentials ; physiology ; Middle Aged ; Nitric Oxide ; metabolism ; Radial Artery ; cytology ; Saphenous Vein ; cytology

Shear stresses acting on vascular endothelial cells due to blood fluid flow play an vital role in regulating their morphology, structure, growth rate and functions. The change in morphology is an instinctive response to biomechanical environment and is an indicator for the functional changes in the cells. In this paper, the morphological research literatures of endothelial cells in the recent years are reviewed and the common morphological parameters are described in detail. At the end, the difficulties of quantitative study of endothelial cell morphology and the future direction of morphological parameters research are also discussed.
Animals ; Biomechanical Phenomena ; Cell Size ; Cells, Cultured ; Endothelium, Vascular ; cytology ; physiology ; Humans ; Intercellular Junctions ; Microscopy, Atomic Force ; Stress, Mechanical