Abstract
Although mast cells are pivotal effector cells in allergic inflammatory reactions, their role of mast cells in the onset and progression of atopic dermatitis is not fully understood. We have recently cloned a novel protein, mast cell surface antigen-1 (MASA-1), and reported that the MASA-1 expression is specifically induced by inflammatory cytokines such as TGF-β1 in chronic inflammatory lung diseases. In this study, the kinetics of mast cell increase in relation to MASA-1 expression was investigated in an animal model of atopic dermatitis. NC/Nga mice were repeatedly treated with 0.1% picryl chloride (PiCl) once a week according to the method reported by Matsuda et al. The scratching behavior was more frequently observed in PiCl-treated mice compared to non-treated mice (control), and the thickness of PiCl-treated ear gradually increased up to 2 months. The symptoms of dermatitis such as dry skin and flare in PiCl-treated mice were also increasingly developed. Histologically, infiltration of mononuclear cells was evident in the lesional tissues, and the number of mast cells was gradually increased. MASA-1 was specifically expressed on mast cells in the skin lesions of atopic dermatitis in PiCl-treated mice, while in the control mice few mast cells showed its expression. These results suggest that MASA-1 may be involved in the pathogenesis of atopic dermatitis. [Jpn J Physiol 54 Suppl:S251 (2004)]
