Production of tissue inhibitor of metalloproteinase-1 and -2 by cultured keratinocytes.

Abstract The imbalance between metalloproteinases and their inhibitors in tissue remodelling is likely to play an important role in various pathologic conditions. In order to understand the role of keratinocytes in regulating extracellular matrix degradation in skin, we analyzed the production of metalloproteinase inhibitors in keratinocytes. Tissue inhibitor of metalloproteinase-1 (TIMP-1) and tissue inhibitor of metalloproteinase-2 (TIMP-2) mRNA were detected in cultured human keratinocytes and mouse transformed keratinocyte cell line (KCMH-1) cells by RT-PCR. On several column chromatography separation steps of the KCMH-1 conditioned medium, two specific inhibitors for mammalian collagenase were purified showing an Mr of 29 kDa and an Mr of 22 kDa, respectively. The analysis of their N-terminal amino acid sequence revealed that two inhibitors were TIMP-1 and TIMP-2. The final preparation of TIMP-1 had a specific activity of 56 000 U/mg and that of TIMP-2 had a specific activity of 26 200 U/mg. Our results suggest that keratinocytes take part in tissue remodelling in skin in secreting both TIMP-1 and TIMP-2.