No abstract

In this study, we demonstrated that tissue inhibitor of metalloproteinases (TIMP) produced by human bone marrow stromal cell line KM-102 had erythroid-potentiating activity (EPA) which stimulates the proliferation of erythroid progenitor cells. We, then, propose a scheme for the bifunctional role of TIMP/EPA in hematopoietic microenvironment, that is, the maintenance of the integrity of bone marrow matrix and the proliferation of erythroid progenitor cells proceeding on the matrix.Tissue inhibitor of metalloproteinases (TIMP); Erythroid-potentiating activity (EPA); Bone marrow stromal cell line (KM 102)

These findings suggest that P. gingivalis SBE may cause connective tissue to be destroyed, contributing to the process of periapical disease, by activating pro-MMP-2 as well as by inactivating TIMP-1 and TIMP-2.

No abstract

We previously found that the enhanced activity to invade Matrigel upon stimulation with 12-O-tetradecanoylphorbol-13-acetate (TPA) was one of the major properties of a highly metastatic variant (L-10) of a human rectal adenocarcinoma cell line RCM-1. To clarify the mechanism of this enhancement, we examined the effect of TPA on 2 major biological factors involved in tumor cell invasion: cell motility and matrix-degrading metalloproteinase activity. The enhanced invasiveness was inhibited by protein-kinase-C inhibitors. TPA markedly enhanced both haptotactic response to type-IV collagen and motility on tissue-culture glass substrate of L-10 cells in a dose-response manner quite similar to that of TPA-enhanced invasion of Matrigel. On the other hand, TPA showed little enhancement of metalloproteinase production, which was assessed by gelatin- and casein-zymography, and of type-IV collagenolytic activity. Addition of TIMP (tissue inhibitors of metalloproteinase)-I inhibited TPA-enhanced invasion of Matrigel by only up to 13%. Thus, TPA treatment of L-10 cells enhanced invasion of Matrigel in association with augmentation of cell motility but did not enhance metalloproteinase activity.