Induction of matrix metalloproteinase-1 in in vitro experimental model using a novel three-dimensional culture system

The aim of this study was to determine whether experimentally punched wounds may influence the connective tissue metabolism of human fibroblast in a three dimensional culture supplemented with L-ascorbic acid. This culture was designed for human dermal fibroblasts to organize a three-dimensional dermis-like structure by accumulating self-produced extracellular matrixes. In order to examine the effects of the wound, mRNA expression and production of type I collagen, matrix metalloproteinase-1 (MMP-1) and tissue inhibitors of metalloproteinase-1 (TIMP-1) were sequentially examined up to 72 hrs after the wound was created, The levels of mRNA expression of MMP-1 were higher at 12 and 24 hrs compared with the initial level and then gradually decreased in studies both with and without wounds. However, the levels of mRNA expression of MMP-1 between 6 to 48 hrs were higher in wounds than in non-wounds. The production of proMMP-1 was also significantly enhanced. There were no significant differences in the levels of mRNA expression or the production of type I collagen and TIMP-1 with the presence or absence of a wound. These results indicate that MMP-1 is synthesized to initiate the tissue restoration in response to the disruption of the three dimensional structure. Thus, this culture system provides a new experimental tool with which to examine the direct effect of mechanical changes on connective tissue metabolism in human dermal fibroblasts.