Measurement of rat mast cell surface antigen-1 (MASA-1) mRNA in a rat model of type I allergy

Abstract

We have reported that rat mast cell surface antigen-1 (MASA-1) with a molecular weight of about 90 kDa was cloned from a rat mast cell line (RBL-2H3 cells). MASA-1 was specifically expressed in the lesional tissues of human chronic inflammatory diseases associated with fibrosis such as interstitial pneumonia and hypertrophic scar. However, the expression of MASA-1 in type I allergy is not clear. In this study, the expression of MASA-1 protein and mRNA were investigated in a rat model of type I allergy using immunostaining and real time PCR. MASA-1 protein was found to be expressed on day 3 to 25 after antigenic stimulation, coincidentally with the infiltration of inflammatory cells, but not immediately after antigenic stimulation. Increments in MASA-1 mRNA levels were observed from 1 to 25 days after stimulation by real time PCR. MASA-1 mRNA levels at 3 and 5 days after stimulation were significantly higher than that before stimulation. These results suggest that inflammatory cells are involved in the expression of MASA-1 on mast cells. We investigated on the effect of TNF-α, one of the chemical mediators in mast cells, on MASA-1 expression by human mast cell line (HMC-1 cells). TNF-α induced MASA-1 protein expression on HMC-1 cells one day after stimulation by immunoblotting. Thus, MASA-1 might be specifically expressed on mast cells in the late phase of type I allergy, and TNF-α induced the up-regulated expression of MASA-1. [J Physiol Sci. 2006;56 Suppl:S240]