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At least 235 records · Page 13Linked to original sources
PubMed1998

Regulation of matrix metalloproteinase-2 (gelatinase A, MMP-2), membrane-type matrix metalloproteinase-1 (MT1-MMP) and tissue inhibitor of metalloproteinases-2 (TIMP-2) expression by elastin-derived peptides in human HT-1080 fibrosarcoma cell line.

Soluble kappa-elastin peptides were shown to stimulate the expression of MMP-2 (but not MMP-9) by human fibrosarcoma HT-1080 cells, both at the protein and mRNA levels; maximal effect being observed at a concentration of 25 microg/ml of kappa-elastin. The stimulatory effect could be reproduced using Val-Gly-Val-Ala-Pro-Gly (VGVAPG) peptide, an elastin-derived hydrophobic hexapeptide which represented the elastin receptor binding sequence of tropoelastin. Furthermore, treatment of cells with lactose (30 mM), which dissociated 67-kDa elastin binding protein (EBP) from cell surfaces, completely abolished this effect, suggesting that the elastin receptor could mediate such a response. Using a specific monoclonal antibody, 67-kDa EBP was detected in HT-1080 membrane preparations by Western immunoblotting. Following treatment with 25 microg/ml kappa-elastin or 200 microg/ml VGVAPG, increased levels of the active 62-kDa form of MMP-2 were found in HT-1080 cell extracts. Stimulation of MT1-MMP mRNA expression by treatment with elastin-derived peptides (EDPs) was shown by competitive polymerase chain reaction (PCR). A reverse zymography analysis revealed that EDPs also stimulated TIMP-2 (but not TIMP-1) production by HT-1080 cells. Competitive PCR confirmed increased TIMP-2 mRNA expression by such treatment. These results suggest that occupancy of the 67-kDa elastin receptor by elastin-derived peptides enhanced both expression and activation of proMMP-2 and consequently, could promote the invasive/metastatic ability of tumor cells expressing this receptor.

Elastin↗
PubMed1998

Cloning of the gene for interstitial collagenase-3 (matrix metalloproteinase-13) from rabbit synovial fibroblasts: differential expression with collagenase-1 (matrix metalloproteinase-1).

Cartilage, bone and the interstitial stroma, composed largely of the interstitial collagens, types I, II and III, are remodelled by three members of the metalloproteinase (MMP) family, collagenase-1 (MMP-1), collagenase-2 (MMP-8) and collagenase-3 (MMP-13). MMP-1 and MMP-13 may contribute directly to disease progression, since they are induced in patients with rheumatoid arthritis and osteoarthritis. The study of MMP-1 and MMP-13 gene regulation in models of arthritic disease has been problematic because mice and rats, which are typically used, only possess a homologue of MMP-13. Here we show that in contrast with mice and rats, rabbits possess distinct genes homologous to human MMP-1 and MMP-13. Furthermore, rabbit MMP-13 is expressed simultaneously with MMP-1 in chondrocytes and synovial fibroblasts in response to the cytokines interleukin-1 and tumour necrosis factor-alpha, or the phorbol ester PMA. The time course of MMP-13 induction is more rapid and transient than that of MMP-1, suggesting that distinct mechanisms regulate the expression of these two collagenases. We have cloned the rabbit MMP-13 gene from synovial fibroblasts and demonstrated that the rabbit gene shares greater homology with human MMP-13 than does the mouse interstitial collagenase. Together with the fact that mice and rats do not possess a homologue to human MMP-1, our data suggest that the rabbit provides an appropriate model for studying the roles of interstitial collagenases in connective-tissue diseases, such as rheumatoid arthritis and osteoarthritis.

Amino Acid Sequence↗
PubMed1996

Matrix metalloprotease 2 (MMP-2) and matrix metalloprotease 9 (MMP-9) type IV collagenases in colorectal cancer.

Using quantitative zymography, we measured activity of the type IV collagenases metalloprotease 2 (MMP-2) and MMP-9 in 192 biopsies from colorectal carcinomas, adenomas, and normal bowel. The median level of MMP-9 in samples from Dukes' stage A (n = 18) or C (n = 48) tumors was significantly higher than in stage B carcinomas (n = 65), adenomas (n = 25), and normals (n = 36; P = 0.0001). The median level of active MMP-2 was significantly higher in stage A or C compared with adenomas (P = 0.0001) and normals (P = 0.0001). The median level of inactive MMP-2 was higher in all Dukes' stages compared with normals and adenomas (P = 0.0001). There was a significant increase in inactive MMP-2 from Jass prognostic groups I-IV (P = 0.006) but no correlation with the active enzyme. MMP activity was not related to tumor differentiation, colon versus rectal location, or disease-free, 5-year survival. All groups expressed mRNA for both enzymes, but there were quantitative and locational differences in MMP-2 mRNA expression between normal, benign, and malignant tissues. Thus MMP-2 is controlled at the level of mRNA and protein production and activation in colorectal cancer, and active MMP-2 and MMP-9 enzymes are associated strongly with Dukes' A and C stages of the disease. Variations in MMP levels with the stage or prognostic group of colorectal cancer reflect their differing stromal content.

Adenoma↗
PubMed1989

Growth rate of human fibroblasts is repressed by the culture within reconstituted collagen matrix but not by the culture on the matrix.

Effect of reconstituted type I collagen gel on in vitro growth of fibroblasts was examined. A prolonged lag period was observed by culture either on the surface of three-dimensional collagen gel ("on-gel") or within the gels ("in-gel") as compared with the culture on plastic dishes. The rate of cell proliferation in logarithmic phase growth was repressed by the culture "in-gel" but not by the culture "on-gel". The differential growth rates between "in-gel" culture and "on-gel" culture should be ascribed to difference in distributions of interacting sites between cell and collagen fibrils. The repression of cell growth was more marked in a contracting collagen gel which contains higher density of collagen fibrils. The cell density in contracted gel per unit cross-section area was found to be much lower than that of confluent monolayer culture. These results suggest that the repression of cell growth by collagen fibrils in the three-dimensional gels is not due to direct cell-cell contact, but due to the distribution and number of contact sites between a cell and collagen fibrils.

Cell Count↗
PubMed1984

Epidermal cell migration on laminin-coated substrates. Comparison with other extracellular matrix and non-matrix proteins.

Pieces of coverslip glass coated with various proteins were implanted under one edge of a fresh skin wound on adult newt hind limbs so that the implant served as wound bed for the migrating wound epithelium. Laminin, a protein that has been implicated as an epithelial-specific adhesin, was a moderately good migration substrate. Type-IV collagen, fibrinogen and fibronectin, however, were significantly better. Fetuin, myoglobin, and casein all proved to be very poor substrates, allowing practically no migration. The inability of fetuin, myoglobin, and casein to support migration is further evidence that the considerable migration that occurs on collagen (Donaldson et al. 1982) fibrinogen and fibronectin (Donaldson and Mahan 1983) and the moderate migration on laminin, is a relatively specific response to these proteins and is therefore of special significance. The fact that laminin is a poorer migration substrate than collagen, fibrinogen or fibronectin suggests that the absence of cell surface laminin that has been associated with epithelial movement in several studies (Stanley et al. 1981; Clark et al. 1982; Madri and Stenn 1982; Gulati et al. 1983) may promote motility by allowing epithelial cells to interact directly with other extracellular macromolecules.

Animals↗