title: Acidic catalase in human skin in vivo: a new marker of permanent damage.
abstract: Malignant melanoma incidence is increasing rapidly in Western countries. Its prevention requires a deep knowledge of the biological basis of the neoplasm leading to the identification of new biological risk markers. In in-vitro and ex-vivo models we demonstrated that catalase was modified not only in its activity but also in its charge properties after ultraviolet A irradiation through pheomelanin. Here we focus on the electrophoretic behaviour of catalase in the human skin in vivo, in association with cutaneous phototype. Zymographic analysis of the enzyme on skin biopsies from Caucasian population (phototype I-IV), collected from the trunk in autumn-winter, to exclude possible influences of an acute photoexposure, evidenced a protein doublet, representing the coexistence of two active isoforms of catalase with different charge properties. In the skin from low-phototype subjects, the percent contribution of the more acidic component of the doublet was prevalent, inversely correlated with total melanin concentration in hair, and associated with a high number of melanocytic nevi. In summary, this study shows for the first time the existence of an acidic catalase in association with clinically defined risk characteristics in low phototype skin in vivo, contributing to the knowledge of a new biochemical marker of cutaneous photosusceptibility.
authors.affiliation: San Gallicano Dermatological Institute IRCCS, Rome, Italy.
authors.forename: Vittoria
authors.initials: V
authors.lastname: Maresca
authors.forename: Enrica
authors.initials: E
authors.lastname: Flori
authors.forename: Claudia
authors.initials: C
authors.lastname: Fabbri
authors.forename: Stefania
authors.initials: S
authors.lastname: Briganti
authors.forename: Giustino
authors.initials: G
authors.lastname: Mariani
authors.forename: Caterina
authors.initials: C
authors.lastname: Catricalà
authors.forename: Mauro
authors.initials: M
authors.lastname: Picardo
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor; D002374:Catalase / Q000378:metabolism*; D005260:Female; D006197:Hair / Q000201:enzymology* / Q000378:metabolism; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D008543:Melanins; D008545:Melanoma / Q000201:enzymology* / Q000378:metabolism*; D008875:Middle Aged; D009508:Nevus, Pigmented; D020033:Protein Isoforms; D012867:Skin / Q000201:enzymology* / Q000378:metabolism; D012878:Skin Neoplasms / Q000201:enzymology / Q000378:metabolism; D014466:Ultraviolet Rays; D055815:Young Adult
chemical_list: D014408:Biomarkers, Tumor; D008543:Melanins; D020033:Protein Isoforms; C018362:pheomelanin; D002374:Catalase