Effects of thrombin on the fibronectin-containing extracellular matrix.

The effects of human alpha-thrombin on the incorporation of exogenous human fibronectin into the extracellular matrix of cultured human skin fibroblasts were studied. Thrombin had no effect on the saturable cell-surface receptor for soluble fibronectin. Thrombin, however, did digest fibronectin bound reversibly to the cell surface and fibronectin incorporated irreversibly into the extracellular matrix. The products of thrombin digestion of cell surface and matrix-bound fibronectin were similar to the products of thrombin digestion of soluble fibronectin. These results indicate that fibronectin can potentially modulate some of the effects of thrombin on cells.