Can the brain inhibit inflammation generated in the skin? The lesson of gamma-melanocyte-stimulating hormone.

The neuro-immuno-cutaneous-endocrine network is not a simple construct featuring organ systems intimately involved in the bridge between body and mind. Mind-body influences are bi-directional and the skin should be considered an active neuroimmunoendocrine interface, where effector molecules of neuropeptides act as common words used in a dynamic dialogue between brain, immune system and skin. Gamma-melanocyte stimulating hormone (gamma-MSH), one of the principal neuroimmunomodulating peptides, seems to exercise some control on the cutaneous inflammatory process, through a central action mediated by descending anti-inflammatory neural pathways and via local direct influence on inflammatory cells infiltrating the dermis, such as monocytes, macrophages and neutrophils. Gamma-MSH down-regulates the production of proinflammatory cytokines, while the production of the anti-inflammatory cytokine IL-10 is stimulated by gamma-MSH. Finally, gamma-MSH seems to regulate the expression of surface molecules in immunocompetent cells. Thus, further studies may lead to the use of gamma-MSH as an important anti-inflammatory agent in clinical dermatology.