Limits...
The CXC-chemokine CXCL4 interacts with integrins implicated in angiogenesis.

Aidoudi S, Bujakowska K, Kieffer N, Bikfalvi A - PLoS ONE (2008)

Bottom Line: We further demonstrate that CXCL4-integrin interaction is of functional significance in vitro, since immobilized CXCL4 supported endothelial cell spreading and migration in an integrin-dependent manner.Soluble CXCL4, in turn, inhibits integrin-dependent endothelial cell adhesion and migration.As a whole, our study identifies integrins as novel receptors for CXCL4 that may contribute to its antiangiogenic effect.

View Article: PubMed Central - PubMed

Affiliation: INSERM, U920, Talence, France. salouaaidoudi@yahoo.fr

ABSTRACT
The human CXC-chemokine CXCL4 is a potent inhibitor of tumor-induced angiogenesis. Considering that CXCL4 is sequestered in platelet alpha-granules and released following platelet activation in the vicinity of vessel wall injury, we tested the hypothesis that CXCL4 might function as a ligand for integrins. Integrins are a family of adhesion receptors that play a crucial role in angiogenesis by regulating early angiogenic processes, such as endothelial cell adhesion and migration. Here, we show that CXCL4 interacts with alphavbeta3 on the surface of alphavbeta3-CHO. More importantly, human umbilical vein endothelial cells adhere to immobilized CXCL4 through alphavbeta3 integrin, and also through other integrins, such as alphavbeta5 and alpha5beta1. We further demonstrate that CXCL4-integrin interaction is of functional significance in vitro, since immobilized CXCL4 supported endothelial cell spreading and migration in an integrin-dependent manner. Soluble CXCL4, in turn, inhibits integrin-dependent endothelial cell adhesion and migration. As a whole, our study identifies integrins as novel receptors for CXCL4 that may contribute to its antiangiogenic effect.

Show MeSH

Related in: MedlinePlus

CXCL4 or CXCL4/CTF mediates αvβ3-CHO cell adhesion through αvβ3 integrins.In A. Dose dependence of αvβ3-CHO cell adhesion to CXCL4 or CXCL4/CTF. αvβ3-CHO and mock-transfected CHO were plated onto microtiter wells coated with the indicated concentrations of CXCL4 or CXCL4/CTF and cell attachment was analyzed as described in Material and Methods. In B, αvβ3-CHO adhesion to CXCL4 or CXCL4/CTF is αvβ3 integrin-dependent. Cells were incubated with the indicated antibodies or RGD-, RGE peptides before plating to wells coated with CXCL4 or CXCL4/CTF. Anti-integrin antibodies used were: anti-αvβ3 (LM609), anti-αv (ΑV1), anti-β3 (B3A). Cell attachment was analyzed as above. Error bars represent the mean±SD, *, P≤0.001; **, P≤0,00001 compared to CXCL4 or CXCL4/CTF in the presence of IgM control antibody; n = 4 independent experiments. In C, adhesion of αvβ3-CHO to immobilized CXCL4 or CXCL4/CTF is cation-dependent manner. The serum free medium used for the adhesion assay contained 0.25 mM of Mn2+, or 2 mM of Mg2+. Cell attachment was analyzed as above. Error bars represent the mean±SD, *, P≤0.005 compared to CXCL4 or CXCL4/CTF alone; n = 4 independent experiments.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC2481302&req=5

pone-0002657-g002: CXCL4 or CXCL4/CTF mediates αvβ3-CHO cell adhesion through αvβ3 integrins.In A. Dose dependence of αvβ3-CHO cell adhesion to CXCL4 or CXCL4/CTF. αvβ3-CHO and mock-transfected CHO were plated onto microtiter wells coated with the indicated concentrations of CXCL4 or CXCL4/CTF and cell attachment was analyzed as described in Material and Methods. In B, αvβ3-CHO adhesion to CXCL4 or CXCL4/CTF is αvβ3 integrin-dependent. Cells were incubated with the indicated antibodies or RGD-, RGE peptides before plating to wells coated with CXCL4 or CXCL4/CTF. Anti-integrin antibodies used were: anti-αvβ3 (LM609), anti-αv (ΑV1), anti-β3 (B3A). Cell attachment was analyzed as above. Error bars represent the mean±SD, *, P≤0.001; **, P≤0,00001 compared to CXCL4 or CXCL4/CTF in the presence of IgM control antibody; n = 4 independent experiments. In C, adhesion of αvβ3-CHO to immobilized CXCL4 or CXCL4/CTF is cation-dependent manner. The serum free medium used for the adhesion assay contained 0.25 mM of Mn2+, or 2 mM of Mg2+. Cell attachment was analyzed as above. Error bars represent the mean±SD, *, P≤0.005 compared to CXCL4 or CXCL4/CTF alone; n = 4 independent experiments.

Mentions: Quantitative cell attachment assays demonstrated that immobilized CXCL4 or CXCL4/CTF supported αvβ3-CHO cell adhesion, but not mock-transfected CHO cells, in a saturable and concentration-dependent manner (Fig. 2A). Also, as shown in Fig 2B, adhesion to CXCL4 or CXCL4/CTF was significantly inhibited by monoclonal antibodies LM609, AV1 and B3A against αvβ3, αv and β3, respectively. These results demonstrate that αvβ3-CHO adhesion on immobilized CXCL4 or CXCL4/CTF is mediated by αvβ3 integrin. Consistent with these results, addition of 10 mM of EDTA, a strong inhibitor of divalent cation-dependent cell integrin receptors, blocks the adhesion of αvβ3-CHO cells to CXCL4 or CXCL4/CTF (Fig. 2B). Furthermore, the incubation of cells with two well established cation activators integrins, Mn2+ and Mg2+ [26], prior to adhesion of cells to immobilized CXCL4 or CXCL4/CTF enhances the cell attachment about 25% (Fig. 2C). These findings indicate that immobilized CXCL4 or CXCL4/CTF mediates αvβ3-CHO cell adhesion in a divalent cation-dependent manner. As with EDTA, addition of RGD-peptides blocks the adhesion of αvβ3-CHO to CXCL4 or CXCL4/CTF, whereas control RGE peptide had no affect on adhesion (Fig. 2B). These findings suggest that the interaction of αvβ3-CHO cells with CXCL4 or -CXCL4/CTF is RGD-dependent. This is consistent with the idea that αvβ3 integrin is a CXCL4 receptor in αvβ3-CHO cells, since αvβ3 is RGD dependent. Taken together, these results demonstrate that αvβ3-CHO cells attachment on immobilized CXCL4 or CXCL4/CTF is a cation-dependent process and is αvβ3 integrin mediated.


The CXC-chemokine CXCL4 interacts with integrins implicated in angiogenesis.

Aidoudi S, Bujakowska K, Kieffer N, Bikfalvi A - PLoS ONE (2008)

CXCL4 or CXCL4/CTF mediates αvβ3-CHO cell adhesion through αvβ3 integrins.In A. Dose dependence of αvβ3-CHO cell adhesion to CXCL4 or CXCL4/CTF. αvβ3-CHO and mock-transfected CHO were plated onto microtiter wells coated with the indicated concentrations of CXCL4 or CXCL4/CTF and cell attachment was analyzed as described in Material and Methods. In B, αvβ3-CHO adhesion to CXCL4 or CXCL4/CTF is αvβ3 integrin-dependent. Cells were incubated with the indicated antibodies or RGD-, RGE peptides before plating to wells coated with CXCL4 or CXCL4/CTF. Anti-integrin antibodies used were: anti-αvβ3 (LM609), anti-αv (ΑV1), anti-β3 (B3A). Cell attachment was analyzed as above. Error bars represent the mean±SD, *, P≤0.001; **, P≤0,00001 compared to CXCL4 or CXCL4/CTF in the presence of IgM control antibody; n = 4 independent experiments. In C, adhesion of αvβ3-CHO to immobilized CXCL4 or CXCL4/CTF is cation-dependent manner. The serum free medium used for the adhesion assay contained 0.25 mM of Mn2+, or 2 mM of Mg2+. Cell attachment was analyzed as above. Error bars represent the mean±SD, *, P≤0.005 compared to CXCL4 or CXCL4/CTF alone; n = 4 independent experiments.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2481302&req=5

pone-0002657-g002: CXCL4 or CXCL4/CTF mediates αvβ3-CHO cell adhesion through αvβ3 integrins.In A. Dose dependence of αvβ3-CHO cell adhesion to CXCL4 or CXCL4/CTF. αvβ3-CHO and mock-transfected CHO were plated onto microtiter wells coated with the indicated concentrations of CXCL4 or CXCL4/CTF and cell attachment was analyzed as described in Material and Methods. In B, αvβ3-CHO adhesion to CXCL4 or CXCL4/CTF is αvβ3 integrin-dependent. Cells were incubated with the indicated antibodies or RGD-, RGE peptides before plating to wells coated with CXCL4 or CXCL4/CTF. Anti-integrin antibodies used were: anti-αvβ3 (LM609), anti-αv (ΑV1), anti-β3 (B3A). Cell attachment was analyzed as above. Error bars represent the mean±SD, *, P≤0.001; **, P≤0,00001 compared to CXCL4 or CXCL4/CTF in the presence of IgM control antibody; n = 4 independent experiments. In C, adhesion of αvβ3-CHO to immobilized CXCL4 or CXCL4/CTF is cation-dependent manner. The serum free medium used for the adhesion assay contained 0.25 mM of Mn2+, or 2 mM of Mg2+. Cell attachment was analyzed as above. Error bars represent the mean±SD, *, P≤0.005 compared to CXCL4 or CXCL4/CTF alone; n = 4 independent experiments.
Mentions: Quantitative cell attachment assays demonstrated that immobilized CXCL4 or CXCL4/CTF supported αvβ3-CHO cell adhesion, but not mock-transfected CHO cells, in a saturable and concentration-dependent manner (Fig. 2A). Also, as shown in Fig 2B, adhesion to CXCL4 or CXCL4/CTF was significantly inhibited by monoclonal antibodies LM609, AV1 and B3A against αvβ3, αv and β3, respectively. These results demonstrate that αvβ3-CHO adhesion on immobilized CXCL4 or CXCL4/CTF is mediated by αvβ3 integrin. Consistent with these results, addition of 10 mM of EDTA, a strong inhibitor of divalent cation-dependent cell integrin receptors, blocks the adhesion of αvβ3-CHO cells to CXCL4 or CXCL4/CTF (Fig. 2B). Furthermore, the incubation of cells with two well established cation activators integrins, Mn2+ and Mg2+ [26], prior to adhesion of cells to immobilized CXCL4 or CXCL4/CTF enhances the cell attachment about 25% (Fig. 2C). These findings indicate that immobilized CXCL4 or CXCL4/CTF mediates αvβ3-CHO cell adhesion in a divalent cation-dependent manner. As with EDTA, addition of RGD-peptides blocks the adhesion of αvβ3-CHO to CXCL4 or CXCL4/CTF, whereas control RGE peptide had no affect on adhesion (Fig. 2B). These findings suggest that the interaction of αvβ3-CHO cells with CXCL4 or -CXCL4/CTF is RGD-dependent. This is consistent with the idea that αvβ3 integrin is a CXCL4 receptor in αvβ3-CHO cells, since αvβ3 is RGD dependent. Taken together, these results demonstrate that αvβ3-CHO cells attachment on immobilized CXCL4 or CXCL4/CTF is a cation-dependent process and is αvβ3 integrin mediated.

Bottom Line: We further demonstrate that CXCL4-integrin interaction is of functional significance in vitro, since immobilized CXCL4 supported endothelial cell spreading and migration in an integrin-dependent manner.Soluble CXCL4, in turn, inhibits integrin-dependent endothelial cell adhesion and migration.As a whole, our study identifies integrins as novel receptors for CXCL4 that may contribute to its antiangiogenic effect.

View Article: PubMed Central - PubMed

Affiliation: INSERM, U920, Talence, France. salouaaidoudi@yahoo.fr

ABSTRACT
The human CXC-chemokine CXCL4 is a potent inhibitor of tumor-induced angiogenesis. Considering that CXCL4 is sequestered in platelet alpha-granules and released following platelet activation in the vicinity of vessel wall injury, we tested the hypothesis that CXCL4 might function as a ligand for integrins. Integrins are a family of adhesion receptors that play a crucial role in angiogenesis by regulating early angiogenic processes, such as endothelial cell adhesion and migration. Here, we show that CXCL4 interacts with alphavbeta3 on the surface of alphavbeta3-CHO. More importantly, human umbilical vein endothelial cells adhere to immobilized CXCL4 through alphavbeta3 integrin, and also through other integrins, such as alphavbeta5 and alpha5beta1. We further demonstrate that CXCL4-integrin interaction is of functional significance in vitro, since immobilized CXCL4 supported endothelial cell spreading and migration in an integrin-dependent manner. Soluble CXCL4, in turn, inhibits integrin-dependent endothelial cell adhesion and migration. As a whole, our study identifies integrins as novel receptors for CXCL4 that may contribute to its antiangiogenic effect.

Show MeSH
Related in: MedlinePlus