Fibrinogen and fibronectin as substrates for epidermal cell migration during wound closure

Pieces of glass coverslip coated with human fibronectin or human fibrinogen were implanted under one margin of a skin wound on adult newt (Notophthalmus viridescens) hind limbs. In contrast to uncoated glass or glass coated with nest serum, bovine serum or bovine serum albumin, glass treated with either fibronectin or fibrinogen supported considerable epidermal cell migration. When optimal amounts of each protein were used, the amount of migration on fibrinogen-coated glass did not differ from the amount on fibronectin-coated glass or from the amount on the wound bed. Migration on a fibronectin substrate, could be blocked by treating the substrate with an antiserum against fibronectin just prior to implantation. Similarly, migration on a fibrinogen substrate could be blocked by exposing it to an antiserum against fibrinogen. While we have yet to determine it fibrinogen and fibronectin are interacting directly with the cell surface, our observations suggest that these two proteins may play an important role in wound closure by providing a suitable substrate for epithelial cell migration.