Immunohistochemical study of chronological and photo-induced aging skins using the antibody raised against D-aspartyl residue-containing peptide.

Background:  Biologically uncommon d-aspartyl residues have been reported in the elderly tissues such as tooth, eye lens, aorta, and brain. We have previously prepared the antibody against d-aspartyl residue-containing peptide and found that it reacted with elastotic material of actinic elastosis. Methods:  Immunoreactivity of the normal skins obtained from sun-exposed and sun-protected skins of varied ages with this antibody was studied. Results:  In the sun-exposed skins, the antibody showed negative reaction with the skin specimens of young donors, whereas it reacted with elastotic materials of actinic elastosis of the elderly. In the sun-protected skins, the antibody recognized elastic fiber-like structures and inner layer of vessels found from the mid to lower dermis of old donors but showed no positive reaction to skin specimens of young donors. Conclusions:  The results suggest that the antibody is a potent marker for chronological and ultraviolet (UV)-induced skin aging. Unusual eosinophilic bodies seen in the superficial dermis in the sun-exposed area of the elderly skins were also immunoreactive with the antibody, suggesting that the eosinophilic bodies resulted from UV-induced skin damage.