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Novel cytokine-independent induction of endothelial adhesion molecules regulated by platelet/endothelial cell adhesion molecule (CD31).

Litwin M, Clark K, Noack L, Furze J, Berndt M, Albelda S, Vadas M, Gamble J - J. Cell Biol. (1997)

Bottom Line: In contrast, cells plated at low density displayed a 17-fold greater expression of E-selectin than did high density ECs with 57 +/- 4% (n = 5) positive for E-selectin expression 15 h after plating, and significant expression still evident 72 h after plating.In contrast, untransfected L cells or L cells transfected with an adhesion-defective domain 2 deletion PECAM-1 mutant failed to regulate E-selectin expression.In an in vitro model of wounding the wound front displayed an increase in the number of E-selectin-expressing cells, and also an increase in the intensity of expression of E-selectin positive cells compared to the nonwounded monolayer.

View Article: PubMed Central - PubMed

Affiliation: Division of Human Immunology, Hanson Centre for Cancer Research, Adelaide, South Australia.

ABSTRACT
Tumor necrosis factor-alpha, interleukin-1, and endotoxin stimulate the expression of vascular endothelial cell (EC) adhesion molecules. Here we describe a novel pathway of adhesion molecule induction that is independent of exogenous factors, but which is dependent on integrin signaling and cell-cell interactions. Cells plated onto gelatin, fibronectin, collagen or fibrinogen, or anti-integrin antibodies, expressed increased amounts of E-selectin, vascular cell adhesion molecule-1, and intercellular adhesion molecule-1. In contrast, ECs failed to express E-selectin when plated on poly-L-lysine or when plated on fibrinogen in the presence of attachment-inhibiting, cyclic Arg-Gly-Asp peptides. The duration and magnitude of adhesion molecule expression was dependent on EC density. Induction of E-selectin on ECs plated at confluent density was transient and returned to basal levels by 15 h after plating when only 7 +/- 2% (n = 5) of cells were positive. In contrast, cells plated at low density displayed a 17-fold greater expression of E-selectin than did high density ECs with 57 +/- 4% (n = 5) positive for E-selectin expression 15 h after plating, and significant expression still evident 72 h after plating. The confluency-dependent inhibition of expression of E-selectin was at least partly mediated through the cell junctional protein, platelet/endothelial cell adhesion molecule-1 (PECAM-1). Antibodies against PECAM-1, but not against VE-cadherin, increased E-selectin expression on confluent ECs. Co- culture of subconfluent ECs with PECAM-1- coated beads or with L cells transfected with full-length PECAM-1 or with a cytoplasmic truncation PECAM-1 mutant, inhibited E-selectin expression. In contrast, untransfected L cells or L cells transfected with an adhesion-defective domain 2 deletion PECAM-1 mutant failed to regulate E-selectin expression. In an in vitro model of wounding the wound front displayed an increase in the number of E-selectin-expressing cells, and also an increase in the intensity of expression of E-selectin positive cells compared to the nonwounded monolayer. Thus we propose that the EC junction, and in particular, the junctional molecule PECAM-1, is a powerful regulator of endothelial adhesiveness.

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Immunofluorescence confocal microscopy of wounded ECs 40 h after plating and 11 h after wounding. a and c are cobblestone  monolayers distant from the wound front. b and d are ECs at wound edges. a and b are stained for PECAM-1, whereas c and d are  stained for E-selectin. b and d are not the same area but are of representative areas along the migrating front. The wound front is  marked with a vertical bar. Bar, 40 μm.
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Figure 11: Immunofluorescence confocal microscopy of wounded ECs 40 h after plating and 11 h after wounding. a and c are cobblestone monolayers distant from the wound front. b and d are ECs at wound edges. a and b are stained for PECAM-1, whereas c and d are stained for E-selectin. b and d are not the same area but are of representative areas along the migrating front. The wound front is marked with a vertical bar. Bar, 40 μm.

Mentions: An in vitro wound assay was established as an in vivo correlate of EC migration (Schimmenti et al., 1992; Taylor and Alexander, 1993). ECs were plated and allowed to come to confluence. At variable times thereafter wounds were made and the cells stained 11 and 27 h later for E-selectin and PECAM-1. As seen in Fig. 11 b, the cells at the wound front displayed a spread, motile, morphology, and had advanced beyond the wound edge. These migrating cells had less PECAM-1 staining at the cell-to-cell borders. Significantly more ECs at the wound front and immediately behind the front expressed E-selectin in comparison to the nonwounded areas (Fig. 11, c and d), and this was substantiated by direct counts of the number of E-selectin expressing cells (Table II). The proportion of ECs expressing E-selectin in the top 50% range of intensity of expression was 1.7 ± 0.7% in the cell monolayer compared to 16 ± 5.0% at the wound front (mean ± SEM of three separate experiments at 16 h after wounding; P = 0.05).


Novel cytokine-independent induction of endothelial adhesion molecules regulated by platelet/endothelial cell adhesion molecule (CD31).

Litwin M, Clark K, Noack L, Furze J, Berndt M, Albelda S, Vadas M, Gamble J - J. Cell Biol. (1997)

Immunofluorescence confocal microscopy of wounded ECs 40 h after plating and 11 h after wounding. a and c are cobblestone  monolayers distant from the wound front. b and d are ECs at wound edges. a and b are stained for PECAM-1, whereas c and d are  stained for E-selectin. b and d are not the same area but are of representative areas along the migrating front. The wound front is  marked with a vertical bar. Bar, 40 μm.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2139821&req=5

Figure 11: Immunofluorescence confocal microscopy of wounded ECs 40 h after plating and 11 h after wounding. a and c are cobblestone monolayers distant from the wound front. b and d are ECs at wound edges. a and b are stained for PECAM-1, whereas c and d are stained for E-selectin. b and d are not the same area but are of representative areas along the migrating front. The wound front is marked with a vertical bar. Bar, 40 μm.
Mentions: An in vitro wound assay was established as an in vivo correlate of EC migration (Schimmenti et al., 1992; Taylor and Alexander, 1993). ECs were plated and allowed to come to confluence. At variable times thereafter wounds were made and the cells stained 11 and 27 h later for E-selectin and PECAM-1. As seen in Fig. 11 b, the cells at the wound front displayed a spread, motile, morphology, and had advanced beyond the wound edge. These migrating cells had less PECAM-1 staining at the cell-to-cell borders. Significantly more ECs at the wound front and immediately behind the front expressed E-selectin in comparison to the nonwounded areas (Fig. 11, c and d), and this was substantiated by direct counts of the number of E-selectin expressing cells (Table II). The proportion of ECs expressing E-selectin in the top 50% range of intensity of expression was 1.7 ± 0.7% in the cell monolayer compared to 16 ± 5.0% at the wound front (mean ± SEM of three separate experiments at 16 h after wounding; P = 0.05).

Bottom Line: In contrast, cells plated at low density displayed a 17-fold greater expression of E-selectin than did high density ECs with 57 +/- 4% (n = 5) positive for E-selectin expression 15 h after plating, and significant expression still evident 72 h after plating.In contrast, untransfected L cells or L cells transfected with an adhesion-defective domain 2 deletion PECAM-1 mutant failed to regulate E-selectin expression.In an in vitro model of wounding the wound front displayed an increase in the number of E-selectin-expressing cells, and also an increase in the intensity of expression of E-selectin positive cells compared to the nonwounded monolayer.

View Article: PubMed Central - PubMed

Affiliation: Division of Human Immunology, Hanson Centre for Cancer Research, Adelaide, South Australia.

ABSTRACT
Tumor necrosis factor-alpha, interleukin-1, and endotoxin stimulate the expression of vascular endothelial cell (EC) adhesion molecules. Here we describe a novel pathway of adhesion molecule induction that is independent of exogenous factors, but which is dependent on integrin signaling and cell-cell interactions. Cells plated onto gelatin, fibronectin, collagen or fibrinogen, or anti-integrin antibodies, expressed increased amounts of E-selectin, vascular cell adhesion molecule-1, and intercellular adhesion molecule-1. In contrast, ECs failed to express E-selectin when plated on poly-L-lysine or when plated on fibrinogen in the presence of attachment-inhibiting, cyclic Arg-Gly-Asp peptides. The duration and magnitude of adhesion molecule expression was dependent on EC density. Induction of E-selectin on ECs plated at confluent density was transient and returned to basal levels by 15 h after plating when only 7 +/- 2% (n = 5) of cells were positive. In contrast, cells plated at low density displayed a 17-fold greater expression of E-selectin than did high density ECs with 57 +/- 4% (n = 5) positive for E-selectin expression 15 h after plating, and significant expression still evident 72 h after plating. The confluency-dependent inhibition of expression of E-selectin was at least partly mediated through the cell junctional protein, platelet/endothelial cell adhesion molecule-1 (PECAM-1). Antibodies against PECAM-1, but not against VE-cadherin, increased E-selectin expression on confluent ECs. Co- culture of subconfluent ECs with PECAM-1- coated beads or with L cells transfected with full-length PECAM-1 or with a cytoplasmic truncation PECAM-1 mutant, inhibited E-selectin expression. In contrast, untransfected L cells or L cells transfected with an adhesion-defective domain 2 deletion PECAM-1 mutant failed to regulate E-selectin expression. In an in vitro model of wounding the wound front displayed an increase in the number of E-selectin-expressing cells, and also an increase in the intensity of expression of E-selectin positive cells compared to the nonwounded monolayer. Thus we propose that the EC junction, and in particular, the junctional molecule PECAM-1, is a powerful regulator of endothelial adhesiveness.

Show MeSH
Related in: MedlinePlus