Ability of reconstituted high density lipoproteins to inhibit cytokine-induced expression of vascular cell adhesion molecule-1 in human umbilical vein endothelial cells

Previous studies have shown that both high density lipoproteins (HDL) isolated from human plasma and reconstituted HDL (rHDL) are effective inhibitors of adhesion molecule expression in human endothelial cells. In this study rHDL have been used to investigate whether HDL particle shape, size, apolipoprotein composition or lipid composition are important determinants of the ability of HDL to inhibit the TNF-alpha induced expression of vascular cell adhesion molecule-1 (VCAM-1) in human umbilical vein endothelial cells (HUVECs). On the basis of these studies it is possible to draw several firm conclusions. i) Neither phospholipid-containing vesicles nor lipid-free apolipoprotein (apo) A-I inhibit VCAM-1 expression in HUVECs. ii) Simple discoidal complexes containing only phospholipid and apoA-I (discoidal (A-I)rHDL) are sufficient to inhibit the TNF-alpha-induced expression of VCAM-1 in HUVECs. iii) Spherical apoA-I-containing rHDL (spherical (A-I)rHDL) are superior to discoidal (A-I)rHDL as inhibitors. iv) The particle size of spherical (A-I)rHDL has no influence on the inhibition. v) Spherical rHDL that contain apoA-I are superior as inhibitors of VCAM-1 to those containing apoA-II when the rHDL preparations are equated for apolipoprotein molarity. However, when compared at equivalent particle molarities, this difference is no longer apparent. vi) Replacement of cholesteryl esters with triglyceride in the core of spherical (A-I)rHDL has no effect on the ability of these particles to inhibit VCAM-1 expression. From these results it is tempting to speculate that variations in inhibitory activity may contribute to the variations observed in the anti-atherogenicity of different HDL subpopulations.-Baker, P. W., K-A. Rye, J. R. Gamble, M. A. Vadas, and P. J. Barter. Ability of reconstituted high density lipoproteins to inhibit cytokine-induced expression of vascular cell adhesion molecule-1 in human umbilical vein endothelial cells.     

Rickettsia conorii infection enhances vascular cell adhesion molecule-1- and intercellular adhesion molecule-1-dependent mononuclear cell adherence to endothelial cells

Leukocyte adherence to the endothelium is an essential component of the inflammatory response during rickettsial infection. In vitro, Rickettsia conorii infection of endothelial cells enhances the expression of adhesive molecules E-selectin, intercellular adhesion molecule-1 (ICAM-1), and vascular cell adhesion molecule-1 (VCAM-1) in a time- and dose-dependent manner. Rickettsial lipopolysaccharide does not seem to be involved, because polymyxin B does not reduce their expression. The intracellular presence of the organism and de novo host protein synthesis are required for expression of cell adhesive molecules, since rickettsial inactivation by formol and pretreatment of cells with cycloheximide inhibits an increase in expression. The contribution of interleukin-1alpha (IL-1alpha) to this endothelial adhesive phenotype was shown by inhibitory experiments 8 and 24 h after infection with IL-1 receptor antagonist and IL-1alpha blocking antibodies. Enhanced adherence of mononuclear cells to infected endothelial cells involved VCAM-1- and ICAM-1-dependent mechanisms at the late phase of the inflammatory response. This endothelial adhesive phenotype may constitute a key pathophysiologic mechanism in R. conorii-induced vascular injury.     

Platelet endothelial cell adhesion molecule-1 expression modulates endothelial cell migration in vitro

Arabidopsis thaliana seeds imbibed for a short duration show phytochrome B (PhyB)-specific photo-induction of germination. Using this system, the relationship was determined between the amount of PhyB in seeds and photon energy required for PhyB-specific germination in two transgenic Arabidopsis lines transformed with either the Arabidopsis PhyB cDNA (ABO) or the rice PhyB cDNA (RBO). Immunochemical detection of PhyB apoprotein (PHYB) showed that the expression level of PHYB in ABO seeds was at least two times higher than that in the wild-type seeds, but in RBO seeds the PHYB level was indistinguishable from that in wild-type seeds. The photon fluence required for induction and photoreversible inhibition of germination was examined using the Okazaki large spectrograph. At the wavelengths of 400-710 nm, the ABO seeds required significantly less photon fluence than wild-type seeds for induction of germination, whereas the RBO seeds required similar fluence to wild-type seeds. A critical threshold wavelength for either induction or inhibition of germination of ABO seeds shifted towards the longer wavelengths relative to wild-type seeds. By assuming that PhyA and PhyB are similar in their photochemical parameters, amounts of Pfr at each wavelength were calculated. The photon fluence required for 50% germination was equivalent to the fluence generating a Pfr/Ptot ratio of 0.21-0.43 in wild-type seeds, and of 0.035-0.056 in ABO seeds. These results indicate that PhyB-specific seed germination is not strictly a function of the Pfr/Ptot ratio, but is probably a function of the absolute Pfr concentration.     

Eosinophil tethering to interleukin-4-activated endothelial cells requires both P-selectin and vascular cell adhesion molecule-1

We examined the mechanisms used by eosinophils to tether and accumulate on interleukin-4 (IL-4)-stimulated human umbilical vein endothelial cells (HUVECs) under flow conditions. As previously reported, HUVECs treated for 24 hours with 20 ng/mL IL-4 had increased expression of P-selectin and vascular cell adhesion molecule-1 (VCAM-1) but not E-selectin. We found that eosinophils tethered and rolled on IL-4-stimulated HUVECs at physiologic shear stresses. Eosinophil rolling was quickly followed by firm adhesion. Treatment with either an anti-P-selectin monoclonal antibody (MoAb) or an anti-VCAM-1 MoAb decreased both eosinophil tethering and accumulation at 2 dyn/cm2. VCAM-1 interacts with 4-integrins expressed on eosinophils. We found that an anti-4-integrin MoAb also blocked eosinophil tethering and accumulation at 2 dyn/cm2. None of these MoAbs alone had an impact on eosinophil accumulation at lower shear stresses, but when either an anti-VCAM-1 or an anti-4-integrin MoAb was used in combination with an anti-P-selectin MoAb, all eosinophil tethering and accumulation on IL-4-stimulated HUVECs were blocked. This was true at both high and low shear stresses. These data show that both P-selectin and VCAM-1 are required to tether eosinophils at high shear stresses, but at low shear stresses these adhesion proteins can act independently to recruit eosinophils to IL-4-stimulated HUVECs.     

Expression of vascular cell adhesion molecule-1 by vascular endothelial cells in immune and nonimmune inflammatory reactions in the skin

Expression of VCAM-1 was compared with that of E-selectin in cytokine-induced lesions and in delayed-type hypersensitivity reactions to tuberculin purified protein derivative (PPD) in pig skin. Lumenally expressed Ags were quantified by measuring localization in skin of i.v. injected (111)In-mAb 10.2C7 (anti-vascular cell adhesion molecule-1 (anti-VCAM-1), (125)I-mAb 1.2B6 (anti-E-selectin), and (99m)Tc-MOPC21 (control IgG1). Anti-VCAM-1 mAb uptake was greater following intradermal (i.d.) injection of TNF-alpha than following injection of IL-1, while the two cytokines induced similar uptake of anti-E-selectin. In immunologically naive pigs there was no detectable increase in anti-VCAM-1 after i.d. injection of PPD, although anti-E-selectin uptake was increased at 3 and 6 h. In contrast, i.d. injection of PPD in sensitized pigs led to increased uptake of both anti-VCAM-1 and anti-E-selectin at 6, 8, 24, and 48 h, each of which was significantly greater than the uptake of control IgG1 into the same lesions (each p < 0.01). Anti-TNF-alpha mAb abolished the increased uptake of anti-VCAM-1 3 and 8 h following i.d. injection of PPD in sensitized pigs and significantly inhibited uptake at 24 h (p = 0.0025), but did not significantly reduce uptake of anti-E-selectin. We conclude that in this delayed-type hypersensitivity model 1) E-selectin expression by endothelial cells follows sequential Ag nonspecific and immune-specific phases, 2) increased VCAM-1 expression by endothelial cells is only seen in sensitized animals, and 3) expression of VCAM-1 appears to be relatively more dependent on TNF-alpha than E-selectin. Differential expression of E-selectin and VCAM-1 may influence the leukocytic infiltrate during the course of nonspecific and immune-specific inflammatory reactions.     

Platelet endothelial cell adhesion molecule-1 expression during mouse postimplantation development

The proteasome is an unusually large multisubunit proteolytic complex, consisting of a central catalytic machine (equivalent to the 20S proteasome) and two terminal regulatory subcomplexes, termed PA700 or PA28, that are attached to both ends of the central portion in opposite orientations to form the enzymatically active proteasome. Totally about 40 subunits with sizes of 20-110 kDa are assembled to form two types of the proteasomal complexes with the same catalytic core and different regulatory modules. To date, cDNAs or genes encoding almost all subunits of human and the budding yeast proteasomes have been isolated by molecular-biological techniques. In this minireview, I summarize briefly available information on the structure-function relationships of the proteasome acting as a protein death machinery.     

Antibodies to proteinase 3 mediate expression of vascular cell adhesion molecule-1 (VCAM-1)

Although much is known about the characteristics of employees who smoke cigarettes, very little is known about workers who use smokeless tobacco. The current study was designed to understand the characteristics of smokeless tobacco users in relation to their performance at work and compare them with smokers and former tobacco users. Data were collected via interviews and questionnaires from a random sample of employees working at Pacific Lumber Company (N = 146), the largest single-site lumber mill in California. A total of 63 smokeless tobacco users (21 of whom also smoked cigarettes), 43 cigarette smokers, and 40 employees who had successfully quit using tobacco (34 of whom previously used cigarettes only) provided information about their health behavior, quality of work life, and performance at work. Analyses revealed that smokeless tobacco users reported less healthful sleep patterns, drank alcohol more often, were intoxicated more often, reported less job satisfaction and organizational commitment, and reported that both chewers and smokers do not work as hard and take more breaks than do tobacco-free employees (quitters). Specific differences among chewers-only, smokers-only, smokers-and-chewers, and quitters are presented. Results suggest the organizational value of developing worksite cessation programs for smokeless tobacco users.     

In vitro intercellular adhesion molecule-1 expression on brain endothelial cells in multiple sclerosis

To investigate the origin of intercellular adhesion molecule-1 (ICAM-1) and its expression on brain endothelial cells, we studied the expression in vitro of ICAM-1 on human brain endothelial cells after incubation of T cells from patients with multiple sclerosis (MS) using a histochemical technique and flow cytometry. We determined soluble forms of ICAM-1 (ICAM-1) in the supernatants after mixtures of brain endothelial cells and T cells from patients with MS using an enzyme-liked immunosorbent assay. Flow cytometric analysis showed that a number of ICAM-1-positive cells were significantly increased after incubation of brain endothelial cells with T cells from patients with acute relapsing MS during an exacerbation as compared with those of controls (P < 0.01). Patients with acute relapsing MS during an exacerbation and chronic progressive MS exhibited higher levels of ICAM-1 in the supernatants of mixtures with brain endothelial cells and lymphocytes than those of controls (P < 0.001 and P < 0.01, respectively). These results suggest that lymphocytes from patients with acute relapsing MS during an exacerbation lead to an increased expression of ICAM-1 on the brain endothelial cells and add to evidence involving this adhesion molecule in the pathogenesis of MS.     

Circulating vascular cell adhesion molecule-1 in pre-eclampsia, gestational hypertension, and normal pregnancy: evidence of selective dysregulation of vascular cell adhesion molecule-1 homeostasis in pre-eclampsia

The potential of DNase I to increase cystic fibrosis sputum elastase activity and lung damage was evaluated. Sputum from CF patients induced little lung hemorrhage when instilled intranasally in C57BL/6 mice. However, sputum treated in vitro by the addition of 1 mg/ml bovine DNase I showed increased neutrophil elastase activity (7.97 +/- 1.56 versus 3.91 +/- 0.62 microM, p < 0.01) and induced marked lung hemorrhage in mice (bronchoalveolar lavage fluid hemoglobin = 192.8 +/- 40.7 versus 44.5 +/- 12.0 microg/ml, p < 0.01). These effects were not observed with DNase I alone in phosphate buffer and were suppressed by the human neutrophil elastase inhibitor methoxysuccinyl-alanyl-alanyl-prolyl-valine-chloromethylketone (MeOSAAPV-CMK). In vivo administration of 2.5 mg aerosolized recombinant human DNase I to patients with CF resulted in a 2.2-fold increase of sputum elastase activity within 1 h of treatment. Elastase levels returned to pre-rhDNase therapy levels 24 h after aerosol treatment. Sputum collected 1 h after rhDNase on 4 separate days from two of six patients in which elastase levels were highest, induced lung hemorrhage when instilled intranasally in mice. We conclude that DNase I therapy of patients with cystic fibrosis can acutely increase the elastase activity of sputum and also its potential to induce hemorrhage in the murine lung.     

Circulating vascular cell adhesion molecule-1 (VCAM-1) in atherosclerotic NIDDM patients

Vascular cell adhesion molecule-1 (VCAM-1) has been shown to be highly expressed in atherosclerotic lesions. Although the soluble form of VCAM-1 (sVCAM-1) is detected in human sera, the relation between the degree of atherosclerosis and serum sVCAM-1 level has not been defined. In the present study, sVCAM-1 concentrations were measured in sera from 101 Japanese NIDDM patients. The mean +/- SD serum sVCAM-1 concentration in 26 patients with symptomatic atherosclerotic vascular diseases (789 +/- 187 ng/ml) was higher than that in 75 patients without the disease (664 +/- 175 ng/ml). Among the 101 NIDDM patients, 56 had atherosclerotic change of the carotid arteries, based on the evaluation by high-resolution B-mode ultrasonography. Their sVCAM-1 level was 759 +/- 201 ng/ml, higher than that in 45 patients without any detectable atherosclerosis of the carotid arteries (619 +/- 130 ng/ml). In addition, there was a positive correlation between sVCAM-1 concentration and thickness of the intimal plus medial complex (IMT) of the carotid arteries in the NIDDM patients (r = 0.41, P < 0.0001). Multivariate regression analysis revealed significant predictors of mean IMT value to be sVCAM-1 concentration (F = 62.88, P = 0.0001) and age (F = 9.59, P = 0.0026). By contrast, sVCAM-1 concentration was not increased in nondiabetic patients with atherosclerotic change of the carotid arteries (668 +/- 191 ng/ml; n = 36) compared with those without the atherosclerotic change (632 +/- 177 ng/ml; n = 28), and there was no correlation between sVCAM-1 level and IMT of the carotid arteries in the nondiabetic subjects. These results indicate that circulating sVCAM-1 may be a marker of atherosclerotic lesions in NIDDM patients with symptomatic and asymptomatic atherosclerosis.     

Lipoprotein(a) enhances the expression of intercellular adhesion molecule-1 in cultured human umbilical vein endothelial cells

Quite a substantial number of human disorders have been associated with a primary or a secondary impairment of one or several of the dopaminergic pathways. Among disorders associated with a primary impairment of dopaminergic transmission are Parkinson's disease, striatonigral degeneration, progressive supranuclear palsy, and possibly schizophrenia. Diseases of secondary dopamine dysfunction are chiefly represented by Huntington's disease in which dopaminergic transmission is being interrupted by progressive loss of the striatal neurons bearing the postsynaptic D1- and D2-dopamine receptors. Central dopaminergic systems have anatomical as well as organizational properties that render them unique by comparison to other neurotransmission systems, making them able to play a pivotal role in the modulation of various important brain functions such as locomotor activity, attention, and some cognitive abilities. These properties of dopamine neurons have obviously several implications in the clinical expression of human disorders involving dopamine neuron dysfunction. In addition, they can greatly influence the clinical/behavioral consequences of experimental lesions in animal models of dopamine dysfunctions.     

Corticosteroids inhibit the expression of the vascular endothelial growth factor gene in human vascular smooth muscle cells

The vascular endothelial growth factor (VEGF) is a specific mitogen for vascular endothelial cells and enhances vascular permeability and edemagenesis. VEGF is also a major regulator of angiogenesis and may be a key target for inhibiting angiogenesis in angiogenesis-associated diseases. Among the extensively studied angiostatic compounds are several corticosteroids when used alone or in combination with heparin. In this study we present evidence for an additional mechanism of action of hydrocortisone, cortisone and dexamethasone in inhibiting edemagenesis or angiogenesis. In cultures of aortic human vascular smooth muscle cells these corticosteroids (1 x 10(-8) to 1 x 10(-12) M) abolished the platelet-derived growth factor-induced (PDGF) expression of the VEGF gene in a dose-dependent manner. In contrast, two precursors of corticosteroids, desoxycorticosterone or pregnenolone, did not affect PDGF-induced VEGF expression. Our findings indicate that the capacity of corticosteroids to reduce edema or to prevent new blood vessel formation may be attributed, at least in part to the ability of these agents to abolish the expression of VEGF.