Proteoglycans and cutaneous vascular defense and repair

Proteoglycans are hybrid molecules composed of a core protein and covalentl y attached glycosamino-glycan chain(s), The structure, location, and proces sing of these molecules enables them to encode specific information that is used in multiple physiologic processes. Endothelial cells in the skin are influenced by proteoglycans through binding interactions between glycosamin oglycans and extracellular matrix, growth factors, cytokines, adhesion rece ptors, enzymes, and enzyme inhibitors. In wound repair, proteoglycans such as the syndecans are induced by antimicrobial peptides and can control grow th factor responsiveness. The glycosaminoglycans further signal endothelial cells to increase expression of ICAM-1 and other molecules important for l eukocyte adhesion. Thus, proteoglycans represent a powerful central regulat ory element in skin that influences a wide variety of events and participat es in host defense and tissue repair.