Expression of neuropeptides and their receptors in melasma

Abstract

Background: The pathogenesis of melasma has not yet been clearly demonstrated. But, clinical manifestations such as remarkable lesional symmetry and the distribution related to trigeminal nerves, suggest that the neural system could play a pathogenic role in melasma. Objective: This study was carried out to examine the expression of some neuropeptides and their receptors, which are well known to be major contributors of neuroinflammation in many dermatoses, in melasma lesions. Methods: Skin biopsies were obtained from the lesional and non-lesional facial skin of 6 Korean women with melasma. Immunofluorecence staining and confocal laser scanning microscopy were performed. Results: In our results, no difference could be detected with regard to the intensity of immunoreactivity for vasoactive intestinal peptide (VIP), calcitonin gene-related peptide (CGRP), calcitonin gene-related peptide receptor (CGRPR), substance P (SP), substance P receptor (SPR), somatostatin (SOM), pituitary adenylate cyclase activating peptide (PACAP) and pituitary adenylate cyclase activating peptide receptor (PACAPR) in the lesional skins compared with the non-lesional skins. Conclusion: These results suggest that neuroinflammation induced by neuropeptides such as substance P, calcitonin gene-related peptide, vasoactive intestinal peptide, and somatostatin and their receptors included in this study, are not directly associated with melasma pathogenesis.