Fibrin Is a Many Splendored Thing

Abstract

The many splendors of fibrin go far beyond its intrinsic role in hemostasis. Fibrin indirectly contributes to the healing of injured tissue through its ability to bind proenzymes, enzyme inhibitors, extracellular matrix molecules and cells (Clark, 2001). In this issue of the JournalGreer and Andreadis (2003) extend the multiplicity of fibrin functions during wound repair. They demonstrate that by its capacity to bind plasminogen, fibrin indirectly promotes epidermal cell migration. This concept is especially attractive since epidermal cells do not express a receptor for fibrin (Kubo et al, 2001), yet fibrin has been reported to facilitate epithelialization in vitro (Greer et al, 2002) and in vivo (Horch et al, 1998;Pellegrini et al, 1999). To better appreciate the multitude of molecules that can interact with the fibrin clot, a brief overview of the structure and function of fibrinogen and fibrin is warranted.