Endothelium : journal of endothelial cell research最新文献

Endothelial dysfunction has been identified as a major mechanism involved in all the stages of atherogenesis. Evaluation of endothelial function seems to have a predictive role in humans, and therapeutic interventions improving nitric oxide bioavailability in the vasculature may improve the long-term outcome in healthy individuals, high-risk subjects, or patients with advanced atherosclerosis. Several therapeutic strategies are now available, targeting both the synthesis and oxidative inactivation of nitric oxide (NO) in human vasculature. Statins seem to be currently the most powerful category of these agents, improving endothelial function and decreasing cardiovascular risk after long-term administration. Other cardiovascular agents improving endothelial function in humans are angiotensin-converting enzyme inhibitors/angiotensin receptors blockers, which increase NO bioavailability by modifying the rennin-angiotensin-aldosterone system. Newer therapeutic approaches targeting endothelial dysfunction in specific disease states include insulin sensitizers, L-arginine (the substrate for endothelial NO synthase [eNOS]) as well as substances that target eNOS "coupling," such as folates or tetrahydrobiopterin. Although there are a variety of strategies to improve NO bioavailability in human endothelium, it is still unclear whether they have any direct benefit at a clinical level.

The authors have recently reported the presence and asymmetric distribution of the glucose transporters GLUT-1 to -5 and SGLT-1 in the endothelium of rat coronary artery (Gaudreault et al. 2004, Diabetologica, 47, 2081-2092). In the present study the authors investigate and compare the presence and subcellular distribution of the classic glucose transporter isoforms in endothelial cells of cerebral, renal, and mesenteric arteries. The GLUTs and SGLT-1 were examined with immunohistochemistry and wide-field fluorescence microscopy coupled to deconvolution in en face preparation of intact artery. We identified GLUT-1 to -5 and SGLT-1 in the endothelial cells of all three vascular beds. The relative level of expression for each isoform was found comparable amongst arteries. Clusters of the glucose transporter isoforms were found at a high density in proximity to the cell-to-cell junctions. In addition, a consistent asymmetric distribution of GLUT-1 to -5 was found, predominantly located on the abluminal side of the endothelium in all three vascular beds examined (ranging from 68% to 91%, p<.05). The authors conclude that the expression and subcellular distribution of glucose transporters are similar in endothelial cells from vascular beds of comparable diameter and suggest that their subcellular organization may facilitate transendothelial transport of glucose in small contractile arteries.

Clinical evidence suggests that vascular damage plays a key role in the pathophysiology of dengue hemorrhagic fever (DHF). In this study, the authors tested this hypothesis by examining the levels of soluble intercellular adhesion molecule and vascular cell adhesion molecule (sICAM-1 and sVCAM-1), and the presence of circulating endothelial cells (CECs), as evidence of vascular damage, in peripheral blood from DHF patients (n=13). A significant increase in plasma levels of sICAM-1 (n=12) and sVCAM-1 (n=13) was detected by enzyme-linked immunosorbent assay (ELISA) in DHF patients, compared with healthy individuals. Increased numbers of CECs, as detected by the expression of endothelial cell markers (ICAM-1, platelet cell adhesion molecule [PCAM]-1, and CD36) with flow cytometry, were observed in DHF patients (n=4), compared to healthy subjects. The high levels of sICAM-1 and sVCAM-1, together with the presence of CECs in DHF patients, provide further evidence of endothelium damage and activation in DHF patients.

With the commonly used in vivo animal models of angiogenesis, direct extrapolation of results to the human is not possible. The results presented from this study exemplify various phases of angiogenesis, from cell migration to apoptosis. This supports the use of the dental pulp of the developing human tooth as a viable model of in vivo physiologic angiogenesis.

As it was previously reported that Tris-elevated pH acutely activated extracellular regulated protein kinase (ERK) in rat aorta smooth muscle cells, this study tested whether this finding could be extended to endothelial cells and, moreover, the relevance of this finding in brain microvascular endothelial cells with respect to respiratory-induced hypocapnic alkalosis. Exposure of bovine brain microvascular endothelial cells to pH 7.90 due to Tris for 15 and 30 min activated ERK twofold. In contrast, pH elevated to 7.75 and 7.90 by lowered percent CO2 failed to activate ERK (15, 30, and 60 min). These results suggest that respiratory alkalosis due to hypocapnia does not activate ERK in brain microvascular endothelial cells. The ability of Tris to activate ERK suggests a novel pathway, possibly independent of pH elevation, whereby Tris activates ERK.

Coarctation of aorta (CoA) is often associated with development of vascular abnormalities and hypertension despite successful correction. The aim of the study was to compare concentrations of adhesion molecules and interleukin-6 (IL-6), an inflammatory cytokine in following groups: children with CoA before operation, chidren with CoA after operation, and healthy control children. Seventeen children with CoA and 18 healthy children (control) were investigated. Blood samples were taken 1 day preoperatively and during followup (10.2+/-7.5 months). Serum concentrations of soluble E- and L-selectin, intercellular adhesion molecule-1 (sICAM-1), and IL-6 were measured by enzyme-linked immunosorbent assay (ELISA). On arms, systolic and diastolic blood pressures decreased after surgery. On legs, only systolic, but not diastolic, blood pressure increased significantly. There was no difference in the concentrations of IL-6, sE-, sL-selectin, or sICAM-1 before and after CoA repair. Postoperative ICAM-1 concentration in children with CoA was significantly higher compared to control (321.7+/-93.4 versus 248.8+/-84.3 ng/mL, P=.002). Only preoperative concentration of L-selectin was higher in children with CoA compared to control (1617.7+/-387.5 ng/mL versus 1271.1+/-266.6 ng/mL). The correction of CoA leads to normalization of leukocyte activity. The markers of endothelial damage and proinflammatory activity are not significantly changed by correction of CoA in young children.

To investigate whether antihemostatic function of vascular endothelial cells (VECs) is changed in type-II diabetic model rats, the mRNA expressions of tissue-type and urokinase-type plasminogen activator (t-PA and u-PA), thrombomodulin (TM), PA inhibitor type-1 (PAI-1), and phosphodiesterases (type 3A, 3B, and 4D PDEs) were quantitated by the method of comparative reverse transcriptase-polymerase chain reaction (RT-PCR). VECs from type-II diabetic model Otsuka Long-Evans Tokushima Fatty (OLETF) rats and from its normal counterpart (LETO) rats were cultured for 24 h with dibutyryl adenosine 3',5'-cyclic monophosphate (db-cAMP) or a type-3 PDE inhibitor, cilostazol. Intracellular cAMP concentration was determined by the chemiluminescent enzyme-linked immunosorbent assay (ELISA) system. In cultured VECs from OLETF rats, the basal mRNA expressions of u-PA and TM were significantly decreased as compared to those in cultured VECs from LETO rats. TM mRNA expression in cultured VECs from OLETF rats was increased 2.1-fold at 24 h after treatment with db-cAMP (3 mmol/L). Basal mRNA expressions of type 3A, 3B, and 4D PDEs were significantly higher in VECs from OLETF rats than those from LETO rats. After treatment with cilostazol (30 micromol/L), intracellular cAMP was significantly increased at 60 min and TM mRNA expression was increased 1.5-fold at 24 h. Therefore, elevation of intracellular cAMP by db-cAMP or cilostazol up-regulated TM mRNA expression in cultured VECs from OLETF rats.

The liver sinusoidal endothelial cells (LSECs) constitute a very specialized endothelium. Due to their multiple functions and privileged location in the liver, these cells constitute an excellent target for gene therapy. In this work, the authors investigate the efficiency of retroviral gene transduction as a method for in vitro gene delivery into murine LSECs. Gene transduction into murine LSECs was performed using the PCMMP-eGFP/pIK-MLVgp retrovirus pseudotyped with the vesicular stomatitis virus G glycoprotein (VSV-g), containing eGFP as a reporter gene. Retroviral transduction resulted in a high efficiency of gene transfer (99%) and stable expression of eGFP in LSECs. The retroviral transduction protocol did not affect the morphology or expression of endothelial cell markers or the biological functions of LSECs. The authors have developed conditions for high-efficiency and stable retroviral gene transduction of LSECs. These results raise the possibility of liver gene therapy using LSECs as vehicle for the delivery of therapeutic proteins by means of retroviral vectors.

Immunoglobulins (Igs) against anti-human white blood cells are putative contributors to the development of transfusion-related adverse effects, particularly transfusion-related acute lung injury (TRALI). Studies of Igs that are considered to be implicated in transfusion-related adverse effects have mainly focused on immunoglobulin G (IgG) class antibodies (Abs). In the authors' previous in vitro study, the association of polymorphonuclear neutrophils (PMNs) and lung microvascular endothelial (LME) cells was up-regulated in the presence of normal human serum-derived IgMs, when F(ab')2 fragments of IgMs were specific to low-affinity Fc receptors (FcR) for IgG, namely, Fcgamma R III (CD16) and Fcgamma RII (CD32). In this study, the authors found that CD7 antigen notably expresses in LME cells and that it acts as an Fc receptor for IgM in LME cells.