Modelization of skin endothelium reactivity, modulation by neuropeptides

The endothelial cells which constitute the vascular wall are organo-specific and reflect the biological reaction taking place in the tissue underlying the endothelial layer. This is the key for reparation after local injury, as, for example, response to UV induced production of neuromediators by neurosensory cells and keratinocytes. Endothelial cells react to the injury, mainly by the production of adhesion molecules to recruit competent cells which are selected to adhere extravasate and can operate local anti-inflammatory/immune reaction. We demonstrate that the skin model constituted here by the cooperation of keratinocytes and skin-derived microvascular endothelial cells is specific to the dermal selective processes as compared with the reaction of other organ microvasculary endothelial cells. Consequently, our data confirm that in order to reproduce in vitro local biological reactions it is indeed crucial to use the proper and representative endothelial cells. This is especially illustrated in this work by the conjugated effects produced by the UV of mediators production by keratinocytes and the modulation of their subsequent effect on activation of endothelial cell adhesion capacity.