Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

---

Query: EC:3.4.24.35 (matrix metalloproteinase 9)
2,207 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have examined the effect that cell shape has on production of the 92-kDa gelatinase B, an enzyme of the matrix metalloproteinase family thought to contribute to the invasiveness of both normal and malignant cells. Using the agent poly(HEMA) and a human melanoma cell line that constitutively produces both the 72- and 92-kDa gelatinases, we have found that alteration in cell shape, that is, a change in cell "roundness," resulted in a specific loss of the constitutive production of the 92-kDa gelatinase B. To examine this phenomenon further, cells were treated with an inhibitor of actin polymerization, cytochalasin D. This treatment also resulted in a loss of 92-kDa gelatinase B production, provided the cells were treated with drug from the out-set of the experiment. If the cells were allowed to attach and spread prior to drug exposure, no loss of 92-kDa gelatinase B production was observed. Similar to the poly (HEMA) results, cytochalasin D had little effect on production of the 72-kDa gelatinase A. Treatment with the tubulin polymerization inhibitor colchicine had no effect on 92-kDa gelatinase B production, nor did growth of the cells as three-dimensional tumor spheroids, although an alteration in cell morphology was observed in both instances. This phenomenon was studied in another system, namely, HL-60 cells, which were induced to differentiate into macrophage-like cells in response to TPA treatment and consequently produce the 92-kDa gelatinase B. HL-60 cells treated with TPA and cytochalasin D failed to produce the 92-kDa gelatinase B. These results suggest that the 92-kDa gelatinase B can be regulated by alterations in cell shape but more specifically, by alterations in the organization of the actin cytoskeleton. Furthermore, the mechanism responsible for cell shape/actin cytoskeletal down-regulation of the 92-kDa gelatinase B may be common to many cell types competent to produce this enzymatic activity.
...
PMID:Constitutive production of 92-kDa gelatinase B can be suppressed by alterations in cell shape. 779 86

The levels of mRNA of both gelatinases A and B were dramatically decreased in HIV-infected cells, when compared to uninfected cells. The expression of gelatinase A in HIV-infected cells was selectively increased by tumor necrosis factor (TNF alpha) while the expression of gelatinase B was not affected. In contrast, in uninfected cells TNF alpha down regulated gelatinase B mRNA level, without affecting the gelatinase A. N-acethylcysteine (NAC) increased the levels of mRNA of both gelatinases. The conditioned media from HIV-infected and uninfected cells had comparable level of secreted gelatinase A protein. These data suggest that in monocytic cells different regulatory pathways control gelatinases A and B and that HIV could modulate in vivo the expression of these proteolytic enzymes, critically involved in regulation of invasion of basement membrane.
...
PMID:HIV-1 modulates the expression of gelatinase A and B in monocytic cells. 780 56

Immunohistochemical studies of prostate carcinoma reveal that most primary carcinomas, including high-grade tumors, are surrounded by a basal lamina composed of laminin, type IV collagen, and entactin. In addition to the expected laminin subchains A, B1, B2, subchains M and S are also found. Tenascin, found around normal glands, is seen in 60% of carcinomas. The basal cells of the normal gland express several integrin alpha units including alpha 2,3,4,5,6, and v. Both beta 1 and beta 4 subunits are observed. These integrin units are polarized at the base of the cells where they codistribute with the surrounding extracellular matrix. The integrin alpha 6 beta 4 is associated with hemidesmosomal-like structures, as detected by transmission electron microscopy (TEM). In carcinoma, the beta 4 is not observed and the alpha 6 and beta 1 subunits are variably expressed. The integrin expression in carcinoma is diffuse in the cytoplasmic membrane and not restricted to the basal aspects of the cell. In addition, type VII collagen and the BP 180 protein which are associated with hemidesmosomes are lost, although the BP 230, plectin, and HD1 proteins are variably expressed. Using immunohistochemistry and northern analysis we observed three metalloproteinases in prostate carcinoma--matrilysin, gelatinase A, and gelatinase B. Western blotting and zymogram analysis reveal that of these three, only matrilysin appears to be present in its active form. Recent in situ hybridization studies reveal focal expression of the matrilysin mRNA in 25/33 primary carcinomas. Matrilysin also appears to be highly expressed in prostatic ducts and atrophic glands. Expression of the three metalloproteinases is also seen in prostatic intraepithelial neoplasia lesions.(ABSTRACT TRUNCATED AT 250 WORDS)
...
PMID:Adhesion molecules, extracellular matrix, and proteases in prostate carcinoma. 782 96

Expression of the T24ras oncogene induces malignancy (tumor growth, invasion and metastasis) in cloned rat embryo fibroblasts (CREF T24). In CREF T24, the rate of phosphorylation of eukaryotic translation initiation factor 4E (eIF-4E) is increased, resulting in increased protein synthesis rates. We have recently shown that reducing the protein levels of eIF-4E in CREF T24 (AS4E line) markedly decreases soft-agar colonization, increases tumor latency periods and increases tumor doubling times without significantly altering monolayer growth. In this study, cells with reduced eIF-4E had delayed and reduced invasiveness and decreased experimental metastasis. Furthermore, reduced eIF-4E levels correlated with decreased expression of the metastasis-associated 92-kDa collagenase type-IV and exon-6 variants of the CD44 adhesion molecule [CD44(6v)]. Reduced eIF-4E levels correlated inversely with increased levels of the putative metastasis-suppressor protein nm23. Cell lines established from AS4E tumors and lung metastases exhibited increased levels of eIF-4E protein and protein synthesis rates compared to the AS4E line. Tumor-derived AS4E had the shortened tumor latency periods of CREF T24 but displayed the slow tumor-growth rates of AS4E. Tumor-derived AS4E exhibited the metastatic capacity of CREF T24 controls. Furthermore, tumor- and lung-nodule-derived AS4E expressed levels of CD44 (6v) and the 92-kDa collagenase type IV comparable to CREF T24 and displayed reduced levels of nm23 relative to AS4E. These results demonstrate that eIF-4E is an important effector molecule involved in oncogenic p21ras-induced malignant transformation.
...
PMID:Reduction of translation initiation factor 4E decreases the malignancy of ras-transformed cloned rat embryo fibroblasts. 782 25

The balance between matrix deposition and tissue turnover is fundamental in wound healing. It is likely that the balance between proteolytic enzymes and their inhibitors contributes to this balance. Matrix metalloproteinases are clearly important in tissue turnover, but their roles in wound healing are poorly understood. To investigate this, fluid from healing wounds resulting from mastectomies was collected from 1 h to 10 d post-surgery, and was analyzed for tissue inhibitor of metalloproteinases-1 concentrations. In all cases, tissue inhibitor of metalloproteinases-1 levels were initially comparable to those in serum, but increased rapidly to significantly higher levels within two days, with a tenfold average increase for five patients. On the other hand, zymography revealed that gelatinase A (72 kDa) levels increased moderately, whereas gelatinase B levels (92 kDa) decreased an average of twofold within 4 d. In contrast, fluid from chronic wounds had significantly more gelatinolytic activity, including lower-molecular-weight proteinase species that may represent activated or superactivated gelatinase fragments, as suggested by immunoprecipitation with specific antibodies. Tissue inhibitor of metalloproteinases-1 levels were lower in chronic than in healing wounds. These data may indicate that excess proteolysis in chronic wounds retards successful healing, and results from an imbalance of proteinase and inhibitors, as well as the presence of higher levels of activated metalloproteinases.
...
PMID:Tissue inhibitor of metalloproteinases-1 is decreased and activated gelatinases are increased in chronic wounds. 782 79

Monocyte-derived foam cells figure prominently in rupture-prone regions of atherosclerotic plaques. Peripheral blood monocytes in culture can produce certain enzymes that degrade extracellular matrix, known as matrix metalloproteinases (MMPs). Lipid-laden macrophages may thus contribute to weakening of extracellular matrix of rupture-prone atherosclerotic plaques. However, the spectrum and regulation of MMP production by foam cells remain unknown. To investigate this issue, we isolated lipid-laden macrophages from rabbit aortic lesions produced by a combination of hypercholesterolemia and balloon injury. Freshly isolated aortic macrophage foam cells, identified using cell-specific antibodies, contained immunoreactive stromelysin and interstitial collagenase, whereas alveolar macrophages isolated from the lungs of same rabbits did not. Macrophages from both tissue sources released gelatinolytic activity consistent with the 92-kDa gelatinase. In vitro, lipid-laden aortic macrophages, but not alveolar macrophages, synthesized de novo and released immunoprecipitable stromelysin and collagenase, with or without stimulation by phorbol ester or bacterial lipopolysaccharide. These stimuli caused foam cells to release additional gelatinolytic activity that migrated faster than a purified preparation of 92-kDa gelatinase in substrate-containing polyacrylamide gels, indicating activation of the 92-kDa gelatinase or induction of the 72-kDa gelatinase. Our results show that lipid-laden macrophages elaborate MMPs capable of degrading the major constituents of vascular extracellular matrix even without further stimulation. Therefore, these cells may contribute to remodeling of the extracellular matrix during atherogenesis and to the disruption of plaques often responsible for acute clinical manifestations of atherosclerosis.
...
PMID:Macrophage foam cells from experimental atheroma constitutively produce matrix-degrading proteinases. 783 Dec 99

Matrix metalloproteinase 9 (MMP-9/gelatinase B) has recently been proposed to participate in the destruction of articular cartilage. Here, we report that interleukin 1 (IL-1) enhances the production of the precursor of MMP-9 in rabbit articular chondrocytes in primary culture, and this IL-1-mediated production of proMMP-9 is greatly augmented by cyclooxygenase inhibitors such as diclofenac and indomethacin, whereas the constitutive production of proMMP-2 (progelatinase A) is not modulated by IL-1 and/or cyclooxygenase inhibitors. Exogenous prostaglandin (PG) E1 and PGE2 suppress the proMMP-9 production in a dose-dependent manner. Similar results are also obtained with cultured rabbit synoviocytes. These results provide the first evidence that PGE down-regulates the production of proMMP-9 in chondrocytes and synoviocytes. Thus, cyclooxygenase inhibitors probably exert undesirable catabolic actions on the maintenance of articular cartilage under inflammatory conditions.
...
PMID:Cyclooxygenase inhibitors augment the production of pro-matrix metalloproteinase 9 (progelatinase B) in rabbit articular chondrocytes. 787 5

An extracellular proteasome-like (EP) structure has been isolated from serum-free media conditioned by C6 astrocytoma cells. EP has a native molecular mass of 1000 kDa and is composed of three subunits, two isoelectric variants at 70 kDa and one at 65 kDa. The extracellular proteasome degraded collagen IV, alpha-casein, beta-insulin, and certain synthetic peptide substrates. A 68-kDa type IV collagenase, identified as the activated form of gelatinase A, was also isolated from this medium. The type IV collagenase activity of the proteasome was sensitive to serine protease inhibitors, while the 68-kDa collagenase IV represented the matrix metalloprotease gelatinase A. The general protease activity of the proteasome was sensitive to metalloprotease inhibitors. Western blot analysis indicates a sequence relationship between the 68-kDa type IV collagenase and either one or both of the 70-kDa isoelectric variants of the proteasome; however, the two enzymes appear to be distinct functionally. Comparison with known proteasomes indicates that EP represents a novel proteasome. The complexity of degradative enzymes in the extracellular microenvironment implies that complete inhibition of tumor growth requires at least a combination of serine and metalloprotease inhibitors.
...
PMID:An extracellular proteasome-like structure from C6 astrocytoma cells with serine collagenase IV activity and metallo-dependent activity on alpha-casein and beta-insulin. 787 29

Two human ovarian adenocarcinoma cell lines, MCAS-3 and OVISE-3 were found to secrete little of any type of gelatinase in tissue culture. However, when these cell lines were implanted subcutaneously into nude mice the cyst fluids from the resultant tumors contained gelatinase A and/or B. The enzyme activities, especially of gelatinase B, were much higher in the malignant MCAS-3 tumors than in those of the less malignant OVISE-3 tumor cells. To elucidate the origin of gelatinase B in cyst fluids of the MCAS-3 tumors, murine skin fibroblasts (MSF) were isolated from a subcutaneous tumor in a nude mouse and tested for their proteinase secretion in culture. MSF cells, which secreted some gelatinase A and gelatinase B, were induced to secrete high levels of both enzymes, especially gelatinase B, by co-cultivation with MCAS-3 cells. In addition, gelatinase A activity was induced by incubation of MSF cells with the conditioned medium of either MCAS-3 or OVISE-3 cells, whereas gelatinase B was induced only with that of MCAS-3. Although cytokines or growth factors such as IL-1 beta, TGF-beta 1, TNF-alpha or EGF stimulated the secretion of gelatinases A and B from MSF cells, their effects on gelatinase B activity were far less than that of the MCAS-3 conditioned medium. These results indicate that the major part of gelatinase B activity in the cyst fluids of the ovarian tumors is secreted by host interstitial cells stimulated by tumor-derived humoral factors. Similar tumor cell-host cell interactions may be important in the production of various proteinases in other tumor types.
...
PMID:Marked induction of gelatinases, especially type B, in host fibroblasts by human ovarian cancer cells in athymic mice. 788 18

Progelatinase A is a matrix metalloproteinase involved in the turnover of extracellular matrix (ECM). We report that the ECM produced by bovine corneal endothelial (BCE) cells contains progelatinase A free of tissue inhibitor of metalloproteinase (TIMP2). The matrix-bound progelatinase A can be activated by APMA to generate a 62 kDa and a 45 kDa species with enzymatic activity and is inhibited by TIMP2. The bound progelatinase can be released after treatment of the ECM with gelatinase B. These studies suggest that the ECM can function as a reservoir for progelatinase A which may be readily available for cells in processes such as metastasis, angiogenesis, inflammation and wound healing.
...
PMID:The extracellular matrix produced by bovine corneal endothelial cells contains progelatinase A. 789 41


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>

---