Background: Sensory neuropeptides such as neurokinin A or substance P modulate skin and immune cells the functions of neurokinin receptor activation during neurogenic inflammation. Zinc metalloproteases, such as neutral endopeptidase (NEP) and angiotensin-converting enzyme (ACE), effectively control the bioavailability of these neuropeptide mediators, which are released from sensory nerves, immune and skin cells during cutaneous responses to endogenous or exogenous noxious stimuli. Recently, studies have suggested that neuropeptides are one of the major pathogenetic fact in many dermatoses, such as allergic contact dermatitis (ACD), atopic dermatitis and psoriasis.
Aim: To investigate the expression of major neuropeptides, SP and its degrading enzymes such as NEP and ACE, in the lesions of ACD.
Methods: A skin biopsy was obtained from 10 patients with ACD. We analysed the expression of these molecules by immunohistochemical staining, confocal laser scanning microscopy, western blotting and reverse transcription PCR.
Results: There was a significant increase in expression of SP in keratinocytes from ACD lesions compared with those in control skin. There was also increased expression of ACE but not NEP in ACD.
Conclusion: Neuropeptides and their degrading enzymes, particularly SP and ACE, have a significant role in the pathogenesis of ACD.