Induction of endothelial cell activation by a triple helical alpha2beta integrin ligand, derived from type I collagen alpha1(I)496-507.
Endothelial cell activation involves the elevated expression of cell adhesion molecules, chemoattractants, chemokines, and cytokines. These expression profiles may be regulated by integrin-mediated cell signaling pathways. In the current study, an alpha2beta1 integrin triple helical peptide ligand derived from type I collagen residues alpha1(I)496-507 was examined for induction of human aortic endothelial cell (HAEC) activation. In addition, a "miniextracellular matrix" composed of a mixture of the alpha1(I)496-507 ligand and a second, alpha-helical ligand incorporating the endothelial cell proliferating region of SPARC (secreted protein acidic and rich in cysteine) was studied for induction of HAEC activation. Following HAEC adhesion to alpha1(I)496-507, mRNA expression of E-selectin-1, vascular and intercellular cell adhesion molecules-1, and monocytic chemoattractant protein-1 was stimulated, whereas that of endothelin-1 was inhibited. Enzyme-linked immunosorbent assay analysis demonstrated that E-selectin-1 and monocytic chemoattractant protein-1 expression was also stimulated, whereas endothelin-1 protein expression diminished. Engagement of the alpha2beta1 integrin initiated a HAEC response similar to that of tumor necrosis factor-alpha-induced HAECs but was not sufficient to induce an inflammatory response. Addition of the SPARC119-122 region had only a slight effect on HAEC activation. Other cell-extracellular matrix interactions appear to be required to elicit an inflammatory response. The alpha2beta1 integrin specific triple helical peptide ligand described herein represents a more general in vitro model system by which gene expression and protein production profiles induced by binding to a single cellular receptor type can be quantified.
Department of Chemistry and Biochemistry, Florida Atlantic University, Boca Raton, Florida 33431-0991, USA.
Diane
D
Baronas-Lowell
Janelle L
JL
Lauer-Fields
Gregg B
GB
Fields
D001011:Aorta / Q000166:cytology; D002448:Cell Adhesion; D002455:Cell Division; D002460:Cell Line; D018932:Chemokine CCL2 / Q000096:biosynthesis; D024042:Collagen Type I / Q000737:chemistry*; D018076:DNA, Complementary / Q000378:metabolism; D019040:E-Selectin / Q000096:biosynthesis; D042783:Endothelial Cells / Q000378:metabolism*; D004730:Endothelium, Vascular / Q000166:cytology; D005109:Extracellular Matrix / Q000378:metabolism; D005260:Female; D006801:Humans; D015151:Immunoblotting; D007249:Inflammation; D038982:Integrin alpha2beta1 / Q000378:metabolism*; D018799:Intercellular Adhesion Molecule-1 / Q000096:biosynthesis; D008024:Ligands; D008297:Male; D008875:Middle Aged; D010455:Peptides / Q000737:chemistry; D012333:RNA, Messenger / Q000378:metabolism; D015398:Signal Transduction; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
D018932:Chemokine CCL2; D024042:Collagen Type I; D018076:DNA, Complementary; D019040:E-Selectin; D038982:Integrin alpha2beta1; D008024:Ligands; D010455:Peptides; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; D018799:Intercellular Adhesion Molecule-1