Psoriasis is a chronic inflammatory and immune-mediated skin disease, characterized by epidermal hyperproliferation, abnormal keratinocyte differentiation and angiogenesis, whose skin lesions are promoted by exogenous and endogenous factors. The cutaneous and systemic over-expression of several pro-inflammatory cytokines, observed in the initiation, maintenance and recurrence of skin lesions, is known to be caused also by reactive oxygen species (ROS). For this reason it has been postulated that ROS production and compromised function of antioxidant system may be involved in the pathogenesis of psoriasis. Some typical features of psoriasis, like growth rate, expression of VEGF and iNOS as well as the production of VEGF and nitric oxide (NO) and some antioxidant responses, have already been extensively evaluated in differentiated cells of psoriatic skin, but no indications are still available about, the mesenchymal stem, that may be isolated from skin (S-MSCs)
