ABSTRACT
The cutaneous extracellular matrix (ECM) is compartmentalized into the collagenrich connective tissue matrix of the dermis and a specialized laminin-rich basement membrane that separates the epidermis from the underlying dermis. While both types of ECM are rich in various glycoproteins and proteoglycans, there are differences in the chemical composition and physical properties of the basement membrane and the dermal matrix. The cutaneous basement membrane is rich in laminins (i.e., laminins 5, 10/11), non-fibrillar collagens (i.e., collagen type IV) and proteoglycans (i.e., entactin, perlecan) and forms a sheet-like structure to which the basal keratinocyte layer of the stratified epidermis is attached (1,2). In contrast, the ECM of the dermis consists of layer of loose connective tissue adjacent to the basement membrane, and a deeper layer of dense connective tissue below the loose connective tissue. The dermal ECM consists of fibrillar collagens (i.e., collagens type II, III), non-collagenase proteins (i.e. fibronectin, elastin, fibrillin), and proteoglycans such as aggrecan, that are covalently linked to glycosaminoglycans (GAGs) such as hyaluronin (2,3).
