Perturbation of β₁ integrin function using anti-sense or function-blocking antibodies on corneal cells grown on fibronectin and tenascin

During corneal development, neural crest derivatives from the periocular mesenchyme migrate into the cornea and differentiate into corneal fibroblasts. During this time, these cells interact with a variety of extracellular matrices for proper orientation and development. In the present studies, we have examined the interaction of β₁ integrins on periocular mesenchyme cells (POM) and corneal fibroblasts (CF) with fibronectin and tenascin by perturbing the function of this integrin. POM and CF attached and spread to a much greater extent on fibronectin than on tenascin. An antibody against β₁ integrin, CSAT, decreased spreading and attachment, and resulted in a lack of immuno-detectable β₁ integrin in focal adhesions on fibronectin; few β₁ positive focal adhesions were observed in cells grown on tenascin. An anti-sense retroviral construct decreased endogenous levels of β₁ integrin protein, and caused decreased attachment and spreading as well as sparse, disorganized focal adhesions. These data indicate that in vitro, both POM and CF have β₁ integrins that interact with fibronectin and allow them to attach and spread, while tenascin is anti-adhesive. Further studies using both of these experimental paradigms will clarify whether these interactions also occur in vivo.