Expression of ICAM-1, VCAM-1, E-selectin and TNF-alpha on the endothelium of femoral and iliac arteries in thromboangiitis obliterans

Immunohistochemical light and electron microscopical analysis of surgical biopsies obtained from femoral and iliac arteries of patients with thromboangiitis obliterans (TAO) were performed to investigate the presence of tumour necrosis factor-alpha (TNF-alpha) and expression of the endothelial cell adhesion molecules intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1) and E-selectin. Expression of ICAM-1, VCAM-1 and E-selectin was increased on endothelium and some inflammatory cells in the thickened intima in all TAO patients. Ultrastructural immunohistochemistry revealed contacts between mononuclear blood cells and ICAM-1-, and E-selectin-positive endothelial cells. These endothelial cells showed morphological signs of activation. The present data indicate that endothelial cells are activated in TAO and that vascular lesions are associated with TNF-alpha secretion by tissue-infiltrating inflammatory cells, ICAM-1-, VCAM-1- and E-selectin expression on endothelial cells and leukocyte adhesion via their ligands. The preferential expression of inducible adhesion molecules in microvessels and mononuclear inflammatory cells suggests that angiogenesis contributes to the persistence of the inflammatory process in TAO.     

Adhesion molecules and atherogenesis.

Atherosclerosis is an inflammatory disease of the vessel wall characterized by monocyte infiltration in response to pro-atherogenic factors such as oxidized lipids. Recently, the role of specific adhesion molecules in this process has been explored. The endothelium overlying atherosclerotic lesions expresses P-selectin and the shoulder regions express vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1), which is also expressed on endothelium in regions not prone to plaque development. Serum levels of soluble P-selectin, ICAM-1 and VCAM-1 are elevated in patients with angina pectoris or peripheral atherosclerotic disease. Reconstituted in vitro systems using monocytes on cytokine-activated endothelial cells under shear flow suggested the involvement of P-selectin, L-selectin, VCAM-1, its ligand, VLA-4 integrin and CD18 integrins. Studies of monocyte adhesion in isolated perfused carotid arteries harvested from atherosclerotic (apoE-/-) mice show a predominant involvement of P-selectin and its ligand P-selectin glycoprotein-1 (PSGL-1) in rolling and of VLA-4 and VCAM-1 in firm adhesion. Consistent with these findings, apoE-/- mice that are also deficient for P-selectin show significantly reduced atherosclerotic lesion sizes and are almost completely protected from neointimal growth after vascular injury. Milder effects are also seen in the low-density lipoprotein (LDL) receptor deficient (LDLR-/-) mouse. In a high cholesterol/cholate model, a role of ICAM-1 and CD18 integrins was also shown, but this awaits confirmation in more physiologic models. Transient blockade of the VLA-4/VCAM-1 adhesion pathway by antibodies or peptides in apoE-/- or LDLR-/- mice reduced monocyte and lipid accumulation in lesions. These data suggest that P-selectin, PSGL-1, VLA-4 and VCAM-1 are the most important adhesion molecules involved in monocyte recruitment to atherosclerotic lesions.     

Adhesion molecules on the endothelium and mononuclear cells in human atherosclerotic lesions.

Atherosclerotic lesions show features of a cell-mediated immune inflammatory process. From this viewpoint, the potential role of arterial endothelium in the recruitment of mononuclear cells (T lymphocytes and macrophages) was studied. The endothelium of diffuse intimal thickening (DIT) and atheromatous plaques (AP) in human coronary arteries and abdominal aortas was characterized for the expression of adhesion molecules ELAM-1, ICAM-1, and the major histocompatibility complex (MHC) class II antigens HLA-DR/DP. A marked increase in expression of ICAM-1 and ELAM-1, and to a lesser extent HLA-DR/DP was observed on endothelial cells that were adjacent to subendothelial infiltrates of T lymphocytes (CD3+, CD11a+, HLA-DR/DP+) and macrophages (CD14+, CD11a+, CD11c+, HLA-DR/DP+). This contrasted with a lower or absent expression of these activation markers at sites without prominent inflammatory cell infiltrates. These findings could be demonstrated in DIT as well as in AP. The observations suggest that cytokines produced by the subintimal infiltrates may activate the endothelium in a similar way as is observed in the microvasculature at sites of immune inflammation. The expression of these activation markers in the microvasculature is associated with enhanced leukocyte adhesion, permeability for macromolecules, and procoagulant activity, features known to occur also in early experimental atherosclerosis. The findings therefore support the concept that arterial endothelium plays an active role in the recruitment of mononuclear cells in atherosclerotic lesions.     

The expression of leukocyte-endothelial adhesion molecules is increased in perennial allergic rhinitis.

Accumulating evidence supports the importance of leukocyte-endothelial cell adhesion molecule (CAM) expression as an initiating process in tissue inflammation. To investigate the relevance of CAM expression to allergic airways inflammation, nasal biopsies from patients with perennial allergic rhinitis (n = 8) and from nonatopic healthy volunteers (n = 8) were immunostained with monoclonal antibodies directed against the CAMs, intercellular adhesion molecule-1 (ICAM-1), endothelial cell adhesion molecule-1 (ELAM-1), and vascular cell adhesion molecule-1 (VCAM-1). The endothelial staining of these CAMs was related to the number of vessels within each biopsy, delineated by a monoclonal antibody against Ulex europaeus-1 lectin bound to endothelial cells, and to the number of tissue leukocytes staining for one of the ligands of ICAM-1, the beta 2 integrin, lymphocyte function-associated antigen (LFA-1). Expression of CAMs was related to the number of infiltrating neutrophils, eosinophils, and lymphocytes identified immunohistochemically within the biopsies. ICAM-1 was the most prominent CAM present on the endothelium of the normal nasal mucosa, with less expression of ELAM-1 and only minimal or absent expression of VCAM-1. In perennial rhinitis, both ICAM-1 (P less than 0.05) and VCAM-1 (P less than 0.01) expression on endothelial cells were increased and were positively correlated in their level of expression (P less than 0.002). The number of tissue LFA-1-positive cells was significantly greater (P less than 0.05) in the biopsies from the perennial rhinitics (median, 27.3/mm2) than from the healthy controls (median, 5.3 cells/mm2). LFA-1 expression significantly correlated with the number of ICAM-1-positive vessels (P less than 0.03).(ABSTRACT TRUNCATED AT 250 WORDS)     

Endothelial and smooth muscle cells express leukocyte adhesion molecules heterogeneously during acute rejection of rabbit cardiac allografts.

Interactions of leukocytes with vascular wall cells figure prominently in acute rejection and development of vascular occlusive disease after cardiac transplantation. To investigate the time course and distribution among different types of vessels of expression of endothelial leukocyte adhesion molecules, issues difficult to address in humans, we studied heterotopic transplants of Dutch-Belted rabbit hearts into New Zealand white recipients without immunosuppression (average time to graft failure 8.2 +/- 0.4 days). We found constitutive expression of vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1) by coronary arterial endothelium in normal rabbits, whereas myocardial capillaries and the endocardial lining cells showed little or no expression of VCAM-1. VCAM-1 expression increased within 1 day after transplantation on the endothelium of the transplanted aorta and endocardium and on myocardial microvascular endothelial cells. ICAM-1 expression increased remarkably on all endothelia studied from 2 to 8 days after transplantation. Adhesion molecule expression on coronary artery endothelial cells also increased during severe allograft rejection (from a histological score of 1.7 +/- 0.6 pretransplant to 4.8 +/- 0.2 8 days after transplant for VCAM-1 and from 0.9 +/- 0.6 to 4.4 +/- 0.3 for ICAM-1, n = 43 arteries in 5 animals, mean +/- SD). In addition, coronary artery and aortic smooth muscle cells also showed induction of VCAM-1 and ICAM-1 8 days after transplant. We conclude that endothelial activation in a transplanted organ can occur rapidly and varies among microvascular, endocardial, and coronary artery endothelial cells, a point germane to the interpretation of endomyocardial biopsies. Augmented expression of adhesion molecules precedes temporally leukocyte accumulation in vessels. In addition, our finding of activation of coronary artery smooth muscle cells during acute rejection suggests that such episodes may contribute to the development of accelerated coronary arteriosclerosis.     

Elevated expression in situ of selectin and immunoglobulin superfamily type adhesion molecules in retroocular connective tissues from patients with Graves' ophthalmopathy.

Activation of certain adhesion molecules within vascular endothelium and the surrounding extravascular space is a critical event in the recruitment and targeting of an inflammatory response or autoimmune attack to a particular tissue site. We have recently demonstrated that the adhesion of lymphocytes to cultured retroocular fibroblasts obtained from patients with Graves' ophthalmopathy (GO) is mediated predominantly by the interaction of lymphocyte function-associated antigen-1 (LFA-1), expressed on lymphocytes, with intercellular adhesion molecule-1 (ICAM-1), expressed by these cells following exposure to interferon-gamma (IFN-gamma), tumour necrosis factor-alpha (TNF-alpha), IL-1 alpha or purified thyroid-stimulating immunoglobulins. We now report the expression and localization in situ of several adhesion molecules, ICAM-1, endothelial leucocyte adhesion molecule-1 (ELAM-1), vascular cell adhesion molecule-1 (VCAM-1), and LFA-3 in retroocular tissues derived from patients with severe GO (n = 4) and normal individuals (n = 3). Serial cryostat sections of tissue specimens were processed for immunoperoxidase staining using various MoAbs against ICAM-1, ELAM-1, VCAM-1 and LFA-3. In addition, consecutive sections were stained with MoAbs against LFA-1, CD45RO (UCHL-1)DR-human leucocyte antigen (HLA-DR), CD11b/CD18 (Mac-1), and CD11c/CD18 (p150,95). In GO-retroocular tissues, strong immunoreactivity for ICAM-1 and LFA-3 was detected in blood vessels (> 90%), in perimysial fibroblasts surrounding extraocular muscle fibres, and in connective tissue distinct from extraocular muscle. No ICAM-1 or LFA-3 immunoreactivity was present in extraocular muscle cells themselves. ICAM-1 and LFA-3 immunoreactivity in normal tissues was minimal or absent both in connective and muscle tissues. Vascular endothelium was strongly positive for ELAM-1 and VCAM-1 in GO-retroocular tissues, while VCAM-1 immunoreactivity was minimal (< 5% of blood vessels) and ELAM-1 immunoreactivity was generally absent in normal retroocular tissue. LFA-1-expressing, activated mononuclear cells and memory T lymphocytes (CD3+/CD45RO+) were only detected in GO-retrocular tissues, and were mainly localized around blood vessels and in areas of ICAM-1-expressing connective and perimysial tissue. HLA-DR expression was restricted to GO-tissue specimens, with strong immunoreactivity detected in blood vessels, macrophages and connective tissue and perimysial fibroblasts. No HLA-DR was detectable in extraocular muscle cells. In conclusion, infiltration of the orbit in GO by mononuclear cells, and their targeting within the orbit, may depend upon the coordinate expression of certain adhesion and MHC molecules.(ABSTRACT TRUNCATED AT 400 WORDS)     

Inducible expression of vascular cell adhesion molecule-1 by vascular smooth muscle cells in vitro and within rabbit atheroma.

Vascular cell adhesion molecule-1 (VCAM-1), a mononuclear leukocyte adhesion molecule, is expressed in cultured vascular endothelial cells activated by cytokines and is induced in rabbit aortic endothelium in vivo within 1 week after initiation of an atherogenic diet. We now demonstrate that vascular smooth muscle cells can also express VCAM-1 in rabbit atherosclerotic lesions in vivo and in response to cytokines in vitro. Immunohistochemical staining of aortas from rabbits fed a 0.3% cholesterol-containing diet revealed that a portion of smooth muscle cells within intimal foam cell-rich lesions expressed VCAM-1. The intimal VCAM-1-expressing cells localized predominantly in regions above the internal elastic lamina. These VCAM-1-positive cells had the typical spindle shape of smooth muscle cells but had reduced alpha-actin expression in comparison to normal medial smooth muscle cells, and did not bear markers for endothelium, macrophages, and T cells. In culture, rabbit aortic smooth muscle cells expressed VCAM-1 mRNA and protein in a time- and concentration-dependent fashion when exposed to interferon-gamma or Gram-negative bacterial lipopolysaccharide. Cultured human vascular smooth muscle cells also expressed VCAM-1 mRNA and protein in response to lipopolysaccharide, interferon-gamma, and interleukin-4. The monokines interleukin-1 alpha and tumor necrosis factor-alpha did not induce VCAM-1 expression in either rabbit or human vascular smooth muscle cells. Inducible VCAM-1 expression by vascular smooth muscle cells in vivo during hypercholesterolemia and in vitro in response to certain cytokines suggests a broader range of VCAM-1 functions in vascular biology than heretofore appreciated.     

Expression and cell distribution of the intercellular adhesion molecule, vascular cell adhesion molecule, endothelial leukocyte adhesion molecule, and endothelial cell adhesion molecule (CD31) in reactive human lymph nodes and in Hodgkin''s disease.

The immunocytochemical expression of intercellular adhesion molecule (ICAM-1), vascular cell adhesion molecule (VCAM-1), endothelial leukocyte adhesion molecule (ELAM-1), endothelial cell adhesion molecule (EndoCAM CD31), and HLA-DR antigens was investigated in sections of 24 reactive lymph nodes and in 15 cases of Hodgkin's disease. ICAM-1 was detected in sinus macrophages, follicular dendritic reticulum cells (FDRCs), interdigitating reticulum cells (IDRCs), epithelioid macrophages, Hodgkin's cells (HCs), and vascular endothelium. ICAM-1 expression was often associated with that of HLA-DR antigens. VCAM-1 was detected in FDRCs, in fibroblast reticulum cells (FRCs), in macrophages, and in rare blood vessels. EndoCAM (CD31) was constitutively expressed in all types of endothelial cells, sinus macrophages, and in epithelioid granulomas. ELAM-1 was selectively expressed by activated endothelial cells of high endothelium venules (HEVs). When expression of the inducible adhesion molecules ICAM-1, VCAM-1 and ELAM-1 was comparatively evaluated in HEVs, it was found that ICAM-1 + HEVs were present in all reactive and HD nodes, whereas ELAM-1 and/or VCAM-1 were expressed only in those pathologic conditions characterized by high levels of interleukin-1/tumor necrosis factor (IL-1/TNF) production, such as granulomatosis and Hodgkin's disease. In Hodgkin's disease, the expression of ELAM-1/VCAM-1 was more pronounced in cases of nodular sclerosis and was associated with a significantly higher content of perivascular neutrophils.     

Expression of intercellular adhesion molecule-1 in atherosclerotic plaques.

Immunohistochemistry of human atherosclerotic arteries demonstrates expression of the intercellular adhesion molecule-1 (ICAM-1) on endothelial cells, macrophages, and smooth muscle cells of the plaques. Normal arterial endothelial cells and intimal smooth muscle outside plaques give weaker or negative reactions; these differ from the strong endothelial expression in small vessels. Quantitative color-image analysis of the endothelial layer shows increased expression of ICAM-1 in all subtypes of atherosclerotic lesions, except fibrous plaques. Endothelial expression of ICAM-1 may be involved in the recruitment of monocytes to the lesion, as suggested by its role in the entry of leukocytes, including monocytes, into foci of inflammation. Collaboration with other mechanisms, particularly chemoattractant factors, may be important for this effect. ICAM-1 enhanced monocyte recruitment is a potential mechanism for the growth of an atherosclerotic plaque.     

Direct interaction with primed CD4+ CD45R0+ memory T lymphocytes induces expression of endothelial leukocyte adhesion molecule-1 and vascular cell adhesion molecule-1 on the surface of vascular endothelial cells.

The process of recruitment of leukocytes at sites of inflammation involves direct cell-to-cell interactions between leukocytes and vascular endothelial cells (EC) mediated by various adhesion receptors on leukocytes and their inducible endothelial ligands. In this study we have examined the induction on EC of endothelial leukocyte adhesion molecule-1 (ELAM-1), intercellular adhesion molecule-1 (ICAM-1), and vascular cell adhesion molecule-1 (VCAM-1) upon their interaction with subpopulations of human T cells. When co-cultured with EC both resting CD4+ T and CD8+ T cells caused a modest increase in the expression of endothelial ICAM-1. Moreover, resting CD4+ but not CD8+ T cells induced expression of ELAM-1 and VCAM-1 on a small fraction of unstimulated EC. Prior activation with phorbol 12-myristate 13-acetate (PMA) significantly increased the ability of T cells to up-regulate endothelial ICAM-1 and also induced the expression of both ELAM-1 and VCAM-1. PMA-primed CD4+ T cells induced both VCAM-1 and ELAM-1 on EC more efficiently than CD8+ T cells. Furthermore, the ability to induce the expression of ELAM-1 and VCAM-1 was confined to the CD4+ CD45R0+ memory/primed subpopulation of T cells. This induction of various endothelial adhesion ligands could also be mediated by antigen-primed CD4+ T cell lines. The CD4+ T cell-mediated induction of adhesion ligands required direct intercellular contact with EC because neither cultures of EC and PMA-primed CD4+ T cells separated by a microporous membrane insert nor the conditioned medium of PMA-primed T cells induced expression of ELAM-1 and VCAM-1 on EC. Cyclosporin A significantly inhibited the activation of T cells with PMA but had no effect on the ability of PMA-primed T cells to up-regulate endothelial CAM. Thus, CD4+CD45R0+ T cells via as yet unknown mechanism can significantly enhance the expression of each of the three endothelial adhesion ligands and, thereby, may facilitate the process of recruitment of additional leukocytes to exacerbate inflammation.     

Expression of adhesion molecules in human intestinal graft-versus-host disease.

The distribution of three cellular adhesion molecules, ICAM-1, ELAM-1 and VCAM-1, was studied in normal rectal mucosa and in graft-versus-host disease (GvHD) using immunohistological and morphometric techniques. In normal controls, ICAM-1 was demonstrable on endothelial cells and leucocytes within the lamina propria, ELAM-1 on endothelial cells only and VCAM-1 on lamina propria leucocytes, many of which exhibited long dendritic processes surrounding the glands. In GvHD, the enterocytes became positive for ICAM-1 and this was often associated with the presence of intra-epithelial LFA-1+ lymphocytes and macrophages, the latter containing debris of apoptotic cells. The staining was, however, restricted to the luminal membrane of the epithelial cells, raising doubts about the role of ICAM-1 as a ligand for LFA-1 on mucosal leucocytes in rectal GvHD. ELAM-1 expression was increased in GvHD both in terms of the length of positive endothelium and staining intensity. VACM-1 was increased on endothelial cells but not leucocytes in the lamina propria in contrast to our previous findings in cutaneous GvHD where VCAM-1+ dendritic cells were increased and endothelial cells remained negative. Normal patterns of adhesion molecule staining were seen in two biopsies exhibiting no morphological evidence of GvHD, from patients who had strong clinical evidence of the disease, indicating that immunostaining for these molecules is unlikely to be of help in improving the sensitivity of histological diagnosis. However, the possibility that adhesion molecule staining may be useful in improving diagnostic specificity by helping to distinguish GvHD from identical histological changes produced by irradiation and cytotoxic drugs is worthy of further investigation.     

Anti-atherosclerotic function of Astragali Radix extract: downregulation of adhesion molecules in vitro and in vivo

ABSTRACT: BACKGROUND: Atherosclerosis is considered to be a chronic inflammatory disease. Astragali Radix extract (ARE) is one of the major active ingredients extracted from the root of Astragalus membranaceus Bge. Although ARE has an anti-inflammatory function, its anti-atherosclerotic effects and mechanisms have not yet been elucidated. METHODS: Murine endothelial SVEC4-10 cells were pretreated with different doses of ARE at different times prior to induction with tumor necrosis factor (TNF)-alpha. Cell adhesion assays were performed using THP-1 cells and assessed by enzyme-linked immunosorbent assay, western blotting and immunofluorescence analyses to detect the expression of vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1), phosphorylated inhibitor of kappaB (p-ikappaB) and nuclear factor (NF)-kappaB. We also examined the effect of ARE on atherosclerosis in the aortic endothelium of apolipoprotein E-deficient (apoE-/-) mice. RESULTS: TNF-alpha strongly increased the expression of VCAM-1 and ICAM-1 accompanied by increased expression of p-ikappaB and NF-kappaB proteins. However, the expression levels of VCAM-1 and ICAM-1 were reduced by ARE in dose- and time-dependent manners, with the strongest effect at a dose of 120 mug/ml incubated for 4 h. This was accompanied by significantly decreased expression of p-ikappaB and inhibited activation of NF-kappaB. Immunofluorescence analysis also revealed that oral administration of ARE resulted in downregulation of adhesion molecules and decreased expression of macrophages in the aortic endothelium of apoE-/- mice. ARE could suppress the inflammatory reaction and inhibit the progression of atherosclerotic lesions in apoE-/- mice. CONCLUSION: This study demonstrated that ARE might be an effective anti-inflammatory agent for the treatment of atherosclerosis, possibly acting via the decreased expression of adhesion molecules.     

Progress in computer-generated three-dimensional reconstruction

The expression of PECAM, ICAM-1, VCAM-1, and E-selectin was studied in 64 samples of human coronary arteries taken from 15 explanted hearts obtained within 5 min of transplantation. Normal artery (n=12), predominantly fibrous plaques (n=23), and plaques containing extracellular lipid (n=26) and three segments showing recanalization channels were studied. All endothelial cells strongly and equally expressed PECAM; positive staining was used to check that artefactual denudation of the endothelial surface had not occurred. PECAM was also present in some lipid-filled macrophages. Normal arteries showed no VCAM-1 staining but focal segments of the endothelium were positive for ICAM-1 and E-selectin. ICAM-1 was strongly and constantly expressed by the endothelium over all types of plaques and in macrophages. E-selectin expression was confined to endothelial cells and occurred on the surface in 35 per cent of fibrous and 22 per cent of lipid-containing plaques. VCAM-1 staining of surface endothelium occurred in 39 per cent of fibrous and 20 per cent of lipid-containing plaques. A population of spindle-shaped cells of macrophage type (positive for EMB11 antigen) expressed VCAM-1 in lipid-containing plaques. Adventitial vessels adjacent to plaques showed endothelial expression of ICAM-1 and E-selectin. VCAM-1 staining of adventitial vessel endothelium was associated with local lymphoid aggregation. In conclusion, the expression of cell adhesion molecules is an important element in the inflammatory component of atherosclerosis and contributes to both monocyte and lymphocyte activation and recruitment from advential vessels and the arterial lumen.     

Adhesion molecule expression in Graves'' thyroid glands; potential relevance of granule membrane protein (GMP-140) and intercellular adhesion molecule-1 (ICAM-1) in the homing and antigen presentation processes.

To assess the potential role of adhesion molecules in the pathogenesis of Graves' disease, we examined the expression of several of these adhesion molecules, including intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule (VCAM-1) and granule membrane protein-140 (GMP-140), in sections of Graves' thyroid glands and control thyroids, using immunohistochemical techniques. Up-regulated expression of GMP-140 was frequently observed on endothelial cells (EC) of post-capilliary venules in all Graves' thyroids examined, compared with an occasional weak staining on EC control glands. Some capillary EC around thyroid follicles (perifollicular EC) were strongly positive for GMP-140 in the Graves' thyroids in contrast to a negative staining on the same structures in the control glands. In addition, there was a correlation between the reactivity and frequency of GMP-140 expression on EC and the severity of mononuclear cell (MNC) infiltration in the Graves' thyroids. The expression of ICAM-1 was up-regulated on perifollicular EC and EC of small venules in some thyroids of both Graves' and control groups. Conversely, no significant expression was observed on any type of EC for both endothelial-leucocyte adhesion molecule-1 (ELAM-1) and VCAM-1. However, dendritic-like cells, present within lymphocytic infiltrates, were positive for VCAM-1 in most of the Graves' thyroids examined, especially in those with a severe lymphocytic infiltration. Thyrocytes were constantly negative for the expression of all four adhesion molecules investigated. These data suggest that GMP-140, as well as ICAM-1, could play an important role in the initiation of MNC infiltration in Graves' disease. ELAM-1 and VCAM-1 appear not to be relevant for the migration of MNC from the blood vessels into the target gland, although VCAM-1 expression on dendritic-like cells might play an additively tissue-selective role in autoantigen presentation and subsequent elicitation of autoimmune phenomena.     

ADHESION MOLECULES IN HUMAN CRESCENTIC GLOMERULONEPHRITIS

The expression of the intercellular adhesion molecule-1 (ICAM-1) and its ligand lymphocyte function associated antigen-1 (LFA-1 or αL), the vascular cell adhesion molecule-1 (VCAM-1), endothelial leukocyte adhesion molecule-1 (ELAM-1), and the cellular receptors for extracellular matrix, α 1, α 2, α 3, α 5, α 6, α V, β 1, and β3 integrin subunits, was studied in 28 patients with crescentic glomerulonephritis (GN) related to several mechanisms: four patients with anti-glomerular basement membrane antibodies or anti-GBM disease; 16 with immune complex mediated GN; and eight with pauci-immune GN, associated with vasculitis in four cases. A three-step immunoperoxidase technique was used on sections obtained from frozen renal biopsies. At the initial stage of evolution of the lesions, all the cells of the crescents expressed the β 1, β 3, α 1, α 3, and α V subunits of integrins, ICAM-1, and VCAM-1, and some cells expressed the α 2, α 5, α 6, and αL subunits of integrins along the plasma membrane. At a later stage, when the crescents were fibrocellular, α 3 and α1 subunit expression was polarized, localized mainly in front of the extracellular matrix. In fibrotic crescents, the α 2, α 5, α 6, and αL chains were no longer detected, and VCAM-1 and ICAM-1 expression was decreased. VCAM-1 and ELAM-1 appeared on endothelial cells of peritubular capillaries in relation to the appearance of infiltrating inflammatory cells. The results of this study show that several adhesion molecules were expressed on cells forming crescents and were modified during crescent evolution; that these molecules were up-regulated on endothelial cells in relation to the severity of the inflammatory response; and that whatever the mechanism of the glomerulonephritis, adhesion molecule expression was identical. It can be postulated that adhesion molecules play a role in crescentic glomerulonephritis. Better knowledge of these molecules in human glomerulonephritis may open the way to a new therapeutic approach.     

Adhesion molecule expression in vivo on extraocular muscles (EOM) in thyroid-associated ophthalmopathy (TAO)

TAO is an autoimmune condition characterized by mononuclear cell infiltration of the extraocular muscles (EOM) and/or the orbital fat/connective tissue with associated deposition of glycosaminoglycans (GAG) in the interstitial spaces. In this study, the presence and distribution of the vascular adhesion molecules intercellular adhesion molecule-1 (ICAM-1), endothelial-leucocyte adhesion molecule-1 (ELAM-1), vascular cell adhesion molecule-1 (VCAM-1) and the leucocyte integrins CD11a/CD18, CD11b/CD18, CD11c/CD18 were investigated. Nineteen EOM biopsies were collected from 17 patients with early (n = 6) and late (n = 13) TAO as well as from 12 non-TAO control patients. Consecutive cryostat sections of these biopsies were immunostained with MoAbs to the above-mentioned molecules and haematoxylin and eosin. Primary antibody binding was visualized using an avidin-biotin system. In early untreated TAO specimens, the interstitial and perimysial connective tissue surrounding EOM fibres and numerous mononuclear cells stained strongly for ICAM-1. In contrast, the vascular endothelial cells (ulex lectin-positive) stained strongly for ELAM-1 (E-selectin), VCAM-1 as well as ICAM-1. In late disease, the same distribution of immunoreactivity for ICAM-1, ELAM-1 and VCAM-1 was observed, but with significantly lower staining. The leucocyte integrins (CD11a, CD11b, CD11c) were again expressed at significantly higher levels in early TAO specimens compared with late TAO specimens and were minimal or absent in the EOM biopsies harvested from control patients. In conclusion, increased expression of adhesion molecules studied correlated with early active disease and was reduced in later stages.     

Morphological analysis of leucocyte transmigration in the pleural cavity

The role that pleural mesothelial cells play in leucocyte transmigration into the pleural cavity was investigated in lipopolysaccharide-stimulated mice. Changes in mesothelial cell morphology and changes in expression of adhesion molecules on mesothelial cells and leucocytes were analysed by light microscopy, immunohistochemistry, transmission electron microscopy (TEM) and immuno-scanning electron microscopy (immuno-SEM). After stimulation, the mesothelial cells separated completely from one another before leucocyte penetration across the mesothelial layer occurred. These changes occurred primarily in the immediate vicinity of ribs, where a large number of leucocytes accumulated. Immuno-SEM showed that the expression of intercellular adhesion molecule-1 (ICAM-1) on the parietal pleural mesothelial cells was significantly up-regulated by lipopolysaccharide stimulation, and that of vascular cell adhesion molecule-1 (VCAM-1) was induced. Both were restricted to the microvilli of the mesothelial cells. By contrast, expression of intercellular adhesion molecule-2 (ICAM-2), platelet/endothelial cell adhesion molecule-1 (PECAM-1), mucosal addressin cell adhesion molecule-1 (MAdCAM-1), endothelial leucocyte adhesion molecule-1 (ELAM-1), peripheral node addressin (PNAd) and fibronectin were not detected. Lymphocyte function associated antigen-1 (LFA-1), macrophage-1 molecule (Mac-1) and very late appearing antigen-4 (VLA-4), all ligands of ICAM-1 and VCAM-1, were present on the transmigrated neutrophils and macrophages. These findings demonstrate that the immediate vicinity of ribs is a source of leucocyte migration into the pleural space.     

溶血磷脂酰胆碱对内皮细胞表面粘附分子表达的影响

大量的单核细胞募集是动脉粥样损伤形成的早期表现之一,相关的内皮细胞粘附分子在其中具有积极作用。本文研究了溶血磷脂酰胆碱（Ｌｙｓｏｐｈｏｓｐｈａｔｉｄｙｌｃｈｏｌｉｎｅ,Ｌｙｓｏ－ＰＣ）对培养的人脐静脉内皮细胞（ＨＵＶＥＣｓ）膜上细胞间粘附分子－（Ｉｎｔｅｒｃｅｌｌｕｌａｒ ａｄｈｅｓｉｏｎ ｍｏｌｅｃｕｌｅ－１,ＩＣＡＭ－１）、Ｅ选择素（Ｅｎｄｏｔｈｅｌｉａｌ－ｌｅｕｋｏｃｙｔｅ ａｄｈｅｓｉｏｎ     

Stimulation with thromboxane A2 (TXA2) receptor agonist enhances ICAM-1, VCAM-1 or ELAM-1 expression by human vascular endothelial cells

A previous study reported that intercellular adhesion molecule-1 (ICAM-1) expression by human vascular endothelial cells (HUVEC) is augmented by intracellular signal transmission mainly through the protein kinase C (PKC) system stimulated by TXA₂ receptors. In the present study, we show that a TXA₂ receptor agonist, U46619, augments the expression of not only ICAM-1, but also vascular cell adhesion molecule-1 (VCAM-1) or endothelial leucocyte adhesion molecule-1 (ELAM-1) in HUVEC both at protein and mRNA levels. Pretreatment with SQ29,548 (a TXA₂ receptor antagonist) or PKC inhibitors greatly diminished the extent of U46619-induced mRNA accumulation and surface expression of the adhesion molecules. An inhibitor of nuclear factor κB (NF-κB) activation, PDTC, diminishes U46619-induced VCAM-1 mRNA accumulation. NAC, which inhibits NF-κB and activation protein 1 (AP-1) binding activity, inhibits the expression of ICAM-1 or ELAM-1 at protein and mRNA levels. These findings suggest that ICAM-1 or ELAM-1 expression of HUVEC stimulated via TXA₂ receptors is augmented by induction of NF-κB and AP-1 binding activity through the PKC system, and that VCAM-1 expression is augmented by induction of NF-κB binding activity.     

Adhesion molecules in atopic dermatitis: VCAM-1 and ICAM-1 expression is increased in healthy-appearing skin

In the skin of normal and atopic individuals, the expression of E-selectin (ELAM-1), L-selectin (LECAM-1), P-selectin (CD62), CD31 (PECAM), vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1), and cutaneous lymphocyte antigen (CLA) were compared by immunostaining of skin biopsies which were taken from normal individuals ( n = 17), the healthy-appearing skin of patients with atopic dermatitis ( n = 10), and their acute ( n = 5) and chronic ( n = 6) skin lesions. In contrast to ELAM-1, the expression of VCAM-1 and ICAM-1 was found to be significantly increased in nonlesional atopic skin in comparison to the skin of normal individuals. Moreover, in contrast to normal skin of healthy individuals, nonlesional atopic skin showed a further increase of VCAM-1, ICAM-1, and ELAM-1 when cultured with medium alone. This suggests that certain adhesion molecules are constitutively upregulated in healthy-appearing skin of patients with atopic dermatitis. In addition, atopic skin appears to respond to nonspecific stimuli (such as culture with medium alone) with upregulation of VCAM-1, ICAM-1, and ELAM-1. It is suggested that the observed upregulation of adhesion molecules is mediated by the release of cytokines such as interleukin-4 from cells which reside in atopic skin. The question of whether the inherent upregulation of adhesion molecules in atopic skin contributes to the development of Th2 cells, which have been found to predominate in atopic inflammation, has to be further investigated.