Neuronal nicotinic alpha7 receptors modulate inflammatory cytokine production in the skin following ultraviolet radiation

The anti-inflammatory effects of the neuronal nicotinic receptor alpha7 (nAChR alpha 7) are proposed to require acetylcholine release from vagal efferents. The necessity for vagal innervation in this anti-inflammatory pathway was tested in the skin, which lacks parasympathetic innervation, using ultraviolet radiation (UVB) to induce a local pro-inflammatory response. Cytokine responses to UV in mice administered chronic oral nicotine, a naAChR agonist, were reduced. Conversely, nAChR alpha 7 knock-out mice exposed to UVB elicit an enhanced pro-inflammatory cytokine response in the skin. Altered pro-inflammatory responses correlated with changes in SOCS3 protein. These results demonstrate that nAChR alpha 7 can participate in modulating a local pro-inflammatory response in the absence of parasympathetic innervation. (C) 2007 Elsevier B.V. All rights reserved.