Increased oxidative damage to fibroblasts in skin with and without lesionsin psoriasis

Differences in oxidative damage, as measured by an increase in the carbonyl ation of macromolecules, were determined in situ with skin biopsies from ps oriatic patients and controls. High levels of carbonyl residues were consis tently detected in the dermis and never in the epidermis of sections of the se skin biopsy samples. The dermis of psoriatic skin without lesions had a higher level of carbonylation than the dermis of normal skin. In this study , we found that there was more oxidative damage in cultured fibroblasts pre pared from skin with and without lesions from psoriasis patients than in no rmal fibroblasts from the skin of age-matched controls. The extent of prote in carbonylation in cell extracts was determined by immunoblotting, using a n antidinitrophenylhydrazone antibody, and in intact cells was determined b y immunocytochemical analysis with the same antibody. The higher level of c arbonylation detected was used here as a measure of oxidative stress, and s howed that some oxidative damage occurred before the appearance of typical psoriatic plaques. These results suggest that fibroblasts are affected befo re the onset of psoriasis and that this damage is independent of any inflam matory infiltrate.