title: Interleukin-20 as a target in psoriasis treatment.
abstract: Interleukin-20 (IL-20) is a new member of the IL-10 cytokine family discovered by a structural algorithm. IL-20 transgenic mice displayed skin abnormalities reminiscent of psoriasis, a finding that has prompted the investigation of this new interleukin in relation to this disease. This article reviews the role of IL-20 and its implication in psoriasis. It is shown that IL-20 and its receptors are found in human skin and that IL-20 is involved in proliferation, angiogenesis, and chemotaxis, all characteristics of psoriasis. We demonstrated that IL-20 induced the thickening of human epidermis in vivo; however, this thickening does not seem to be related to a direct effect of IL-20 on hyperproliferation since the growth of normal human epidermal keratinocytes (NHEKs) cultured in vitro was not affected by IL-20. On the other hand, in vitro, IL-20 stimulated human peripheral blood mononuclear cells (PBMCs) to produce proinflammatory cytokines and, in vivo, IL-20 in combination with PBMCs induced psoriasis. This may suggest that IL-20 indirectly exerts its proliferative effects on keratinocytes via immune cells present in the skin. Finally, we found that blocking IL-20 signaling in psoriasis improves psoriasis, suggesting that IL-20 is a potential target in psoriasis treatment.
authors.affiliation: Department of Dermatology, Aarhus University Hospital, P.P. Oerumsgade 11, Bldg. 15, DK-8000 Aarhus, Denmark. Karin.Stenderup@email.dk
authors.forename: Karin
authors.initials: K
authors.lastname: Stenderup
authors.forename: Cecilia
authors.initials: C
authors.lastname: Rosada
authors.forename: Anne
authors.initials: A
authors.lastname: Worsaae
authors.forename: Jes Thorn
authors.initials: JT
authors.lastname: Clausen
authors.forename: Tomas
authors.initials: T
authors.lastname: Norman Dam
mesh_terms: D000818:Animals; D049109:Cell Proliferation; D006801:Humans; D007378:Interleukins / Q000276:immunology* / Q000378:metabolism; D011565:Psoriasis / Q000276:immunology* / Q000378:metabolism / Q000473:pathology / Q000628:therapy*; D018123:Receptors, Interleukin / Q000276:immunology; D015398:Signal Transduction
chemical_list: D007378:Interleukins; D018123:Receptors, Interleukin; C492510:interleukin-20 receptor; C422042:interleukin 20