Integrin receptors and function on cultured glomerular endothelial cells.

Integrin expression and function on a cloned line of rat glomerular endothelial cells (GEndoC) were studied in an effort to obtain a better understanding of the means by which these cells interact with components of the glomerular basement membrane. Cultured GEndoC adhered to fibronectin, laminin and types I and IV collagen and expressed alpha 1 beta 1, alpha 2 beta 1, alpha 3 beta 1, alpha 5 beta 1, alpha v beta 1 and alpha v beta 3 integrins. Synthetic RGDS peptides significantly decreased adhesion to fibronectin (53.1 +/- 4.7% of control). Antibody to rat beta 1 integrin strongly inhibited adhesion to laminin, fibronectin and types I and IV collagen (11.2, 19.0, 67.3 and 31.9% of control adhesion, respectively), while antibody to the rat alpha 1 integrin chain strongly inhibited adhesion to laminin (65.2% of control), but only mildly inhibited adhesion to type IV collagen (77.2% of control) and did not affect adhesion to type I collagen (97.8% of control). Affinity chromatography of GEndoC lysates on a column of immobilized type I collagen displayed predominantly binding of alpha 3 beta 1 integrin with trace amounts of alpha 1 beta 1 and alpha 2 beta 1, documenting the major role of alpha 3 beta 1 in GEndoC adhesion to collagen. Chromatography on the immobilized cell-binding fragment of fibronectin revealed the alpha 5 beta 1 integrin to be the major fibronectin receptor on these cells, but antibody to alpha v beta 3 integrin also documented a minor role for alpha v beta 1 or alpha v beta 3 in fibronectin adhesion.(ABSTRACT TRUNCATED AT 250 WORDS)