Neuropeptides: role in inflammatory skin diseases

The cutaneous nervous system recently has been demonstrated to interact with multiple target cells in the skin and to mediate actions important in inflammatory conditions. Neuropeptides released by cutaneous neurons such as substance P (SP), vasointenstinal peptide (VIP), calcitonine gene regulated peptide (CGRP), proopiomelancortin (POMC) peptides and others modulate the function of immunocompetent and inflammatory cells as well as epithelial and endothelial cells. They have been found to function as mediators of cell proliferation, cytokine and growth factor production as well as adhesion molecule and cell surface receptor expression. In addition many cells including keratinocytes, fibroblasts, endothelial cells and inflammatory cells have been shown to release several neuropeptides and they express their corresponding receptors. These findings indicate that neuropeptides participate in the complex network of mediators that regulate cutaneous inflammation, hyperproliferation and wound healing.