Fibronectin in formation and degradation of the pericellular matrix.

Fibronectin is a large multifunctional glycoprotein present both in soluble form in plasma and other body fluids and in an insoluble form in interstitial connective tissues and in association with most basement membranes. The protein seems to provide a link between circulating body fluids, cell surfaces and the extracellular matrix. At sites of injury, fibronectin, covalently cross-linked to the fibrin clot, may provide a growth substratum for the invading cells and appears through its multiple interactions with other matrix components and cell surfaces to be involved in the organization of the matrix that will replace the clot. Fibronectin deposition may serve as a useful early marker for connective tissue formation in pathological processes and its fragmentation may serve as an indicator of pathological conditions involving proteolytic events.