Eotaxin-induced expression of membrane type 1 matrix metalloproteinase mRNA in human eosinophils

Abstract

Eosinophil penetration across the basement membrane (BM) is thought to be dependent on the degradation of membrane components. In this process, matrix metalloproteinases (MMP) appear to be primarily responsible for degradation of the BM. Matrix metalloproteinases -2 and MMP-9 degrade type IV collagen, which is a major component of the BM. In the present study, the effects of eotaxin, a selective chemoattractant for eosinophils, on the expression of MMP mRNA were examined. Incubation with chemotactically active concentrations of eotaxin for 24 h enhanced the expression of mRNA for membrane-type 1 MMP (MT1-MMP), but not of mRNA for MMP-2 and MMP-9. An increase in the protein level of MT1-MMP was also detected in the cell lysate of eotaxin-treated eosinophils. These results suggest that up-regulation of MT1-MMP expression may be involved in the eotaxin-induced penetration of eosinophils.