Extracellular matrix molecules in skin wound repair

Wound microenvironment has been shown to be critical to the wound healing. Skin wound microenvironment is primarily composed of cells such as fibroblasts, endothelial cells, and matrix proteins such as collagen and laminin and other extracellular matrix (ECM) proteins, as well as cytokines/growth factors released as a result of injury and inflammation. The ECM proteins play important roles in wound healing processes by providing both scaffold support and signaling roles. During wound repair, ECM proteins promote cell adhesion and migration, and mediate the interactions between cells as well as cells and matrices. In addition, they serve as reservoir and modulator for growth factors. ECM binds cells through specific cell surface receptors, of which integrins are likely most important and best studied receptors. The expression and function of these ECM molecules and their receptors are highly regulated spatially and temporally during wound healing and tissue remodeling. In human skin, fibroblasts are the major source for ECM synthesis, however keratinocytes and endothelial cells also produce some of the ECM components, such as type IV and type VII collagens and laminins in basement membranes. Inappropriate deposition of ECM components impairs normal healing and function. In this chapter, we will discuss ECM components and their roles in wound repair.