Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.24.23 (MMP)
 4,246 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The midcycle surge of luteinizing hormone (LH) triggers events within the primate periovulatory follicle that culminate in follicle rupture and luteinization of the follicle wall; these events include the shift from primarily estrogen to primarily progesterone production, vascularization of the granulosa cell layer, and expression of matrix metalloproteinases and their inhibitors (MMPs and TIMPs) thought to be necessary for follicle rupture. However, it is unknown if LH acts directly at granulosa cells to regulate these important periovulatory processes. The ovulatory LH surge also stimulates the production of prostaglandins (PGs) by the follicle just before follicle rupture, suggesting that LH may have both PG-dependent and PG-independent actions. To address these questions, gonadotropins were administered to adult female rhesus monkeys to stimulate the development of multiple, large preovulatory follicles. Granulosa cells were aspirated and maintained in vitro for up to 48 h in serum-free, chemically defined medium. Granulosa cells were cultured with LH alone or in combination with PGs to determine if these hormones act directly at granulosa cells to induce the production of factors implicated in periovulatory processes. LH treatment increased media progesterone (p < 0.05) and vascular endothelial growth factor (VEGF; p < 0.05) levels as well as stimulating expression of mRNAs for MMP-1 (p = 0.05), MMP-9 (p < 0.05), and TIMP-1 (p < 0.05), similar to the effects of an ovulatory dose of gonadotropin in vivo. PGE2 alone elevated media progesterone levels but decreased LH stimulation of MMP- 1 mRNA (p < 0.05). PGF2alpha reduced LH-stimulated TIMP-1 mRNA (p < 0.05) levels. These studies suggest a direct action of LH on granulosa cells to stimulate the processes involved in tissue remodeling and neovascularization, i.e., MMPs/TIMPs and angiogenic factors, as well as steroidogenesis. LH-stimulated PGs may have a regulatory role to modulate some effects of the LH surge, such as MMP/TIMP expression.
 ...
PMID:Luteinizing hormone acts directly at granulosa cells to stimulate periovulatory processes: modulation of luteinizing hormone effects by prostaglandins. 1470 98

Membrane-type 1 matrix metalloproteinase (MT1-MMP) and vascular endothelial growth factor (VEGF) are two key molecules involved in pericellular proteolysis and cell proliferation during tumor growth and angiogenesis. Our previous data showed that MT1-MMP overexpression in human breast carcinoma MCF7 cells induced an up-regulation of VEGF expression. This effect was associated in vivo with accelerated tumor growth and angiogenesis. We now provide evidence that MT1-MMP overexpression specifically affected VEGF-A production and failed to influence that of other VEGF family members (VEGF, B, C, D, or PlGF) or their receptors. The up-regulation of VEGF-A by MT1-MMP was related to an increased transcriptional activation rather than to a modification of mRNA stability. It was blocked by synthetic MMP inhibitors, TIMP2, but not TIMP-1 and abolished by a partial deletion of the catalytic domain or the cytoplasmic tail of MT1-MMP. Analysis of the signal transduction mechanisms demonstrated that MT1-MMP acts through a signaling pathway involving Src tyrosine kinases. Thus, our results provide new insight into the mechanisms of action of MT1-MMP during angiogenesis and suggest that the full enzymatic activity of MT1-MMP is required for a specific up-regulation of VEGF-A through an activation of Src tyrosine kinase pathways.
 ...
PMID:Up-regulation of vascular endothelial growth factor-A by active membrane-type 1 matrix metalloproteinase through activation of Src-tyrosine kinases. 1472 79

Association of matrix metalloprotease 9 (MMP9) to the cell membrane is considered important in tumor growth and angiogenesis. To dissect this regulatory mechanism, we generated raft and non-raft MMP9 chimeras to force membrane expression in the MCF-7 human breast carcinoma cell line. MMP9 targeting to non-raft cell surface domains rendered a constitutive active membrane MMP9 form, suggesting a contribution by the lipid environment in MMP activation. We generated human breast cancer xenograft models using MCF-7 cells overexpressing secreted and membrane-anchored MMP9. The non-raft MMP9 chimera was constitutively active at the cell membrane in xenografts, but this activation did not correlate with an increase in MMP9-induced angiogenesis. Capillary number and vessel perimeter were specifically increased only in tumors overexpressing wild-type MMP9 (the secreted form); this increase was inhibited when tumors were induced in doxycycline-treated mice. Xenografts from tumor cells overexpressing wild-type MMP9 showed increased vascular endothelial growth factor (VEGF)/VEGFR2 receptor association, which was also dependent on MMP9 activity. These observations indicate that membrane location can influence MMP9 activity in vitro and in vivo, and confirm the relevance of stromal-associated, but not tumor-bound MMP9 in mediating tumor-induced angiogenesis.
 ...
PMID:Secreted MMP9 promotes angiogenesis more efficiently than constitutive active MMP9 bound to the tumor cell surface. 1507 44

Distraction osteogenesis (DO) is one of the most dramatic in vivo applications of mechanical stimulation as a means of inducing bone regeneration. A simple and reproducible murine model of tibia distraction osteogenesis was developed using a monolateral fixator. Bone formation was assessed histologically over a 35-day time course. The steady state expression of a broad family of angiogenesis-associated genes was assessed by microarray hybridization analyses over the same time course, while the immediate gene response that was induced during each cycle of distraction was assessed at 30 min and 8 h after the first and last rounds of activation of the fixator. Distraction osteogenesis promoted new bone formation primarily through an intramembranous process with maximal osteogenesis during the active distraction period. Histological analysis also showed that dense cortical bone continued to be formed, during the consolidation phase, for 2 weeks after distraction ended. The analysis of steady state mRNA expression levels over the time course of DO showed that VEGF-A and neuropilin, an alternate receptor for VEGF-A, both angiopoietin (Ang) 1 and 2 factors, and the Ang receptor Tie2 were the critical angiogenic factors during DO. A key transcriptional regulator of many of the angiogenic factors, hypoxia-induced factor1alpha (Hif-1a), the FGF binding protein pleiotropin/OSF1, and multiple MMP(s), were also induced during the active distraction period. Examination of the expression of angiogenic factors that were induced after each cycle of activation, demonstrated that Hif-1a, Nrp1, and VEGF-A were all cyclically induced after each increment of distraction. These results suggest that these factors are early mediators that are produced by distraction and contribute toward the processes that promote bone formation. These experiments represent the first step in defining the molecular mechanisms that regulate skeletal regeneration and the functional relationship between angiogenesis and osteogenesis during distraction osteogenesis.
 ...
PMID:The role of angiogenesis in a murine tibial model of distraction osteogenesis. 1512 Oct 17

We have recently shown that stimulation of endothelial cells with vascular endothelial growth factor (VEGF) induces dissociation of caveolin-1 from the VEGFR-2 receptor, followed by Src family kinase-dependent tyrosine phosphorylation of the protein (Labrecque, L., Royal, I., Surprenant, D. S., Patterson, C., Gingras, D., and Beliveau, R. (2003) Mol. Biol. Cell 14, 334-347). In this study, we provide evidence that the VEGF-dependent tyrosine phosphorylation of caveolin-1 induces interaction of the protein with the membrane-type 1 matrix metalloproteinase (MT1-MMP). This interaction requires the phosphorylation of caveolin-1 on tyrosine 14 by members of the Src family of protein kinases, such as Src and Fyn, because it is completely abolished by expression of a catalytically inactive Src mutant or by site-directed mutagenesis of tyrosine 14 of caveolin-1. Most interestingly, the association of MT1-MMP with phosphorylated caveolin-1 induced the recruitment of Src and a concomitant inhibition of the kinase activity of the enzyme, suggesting that this complex may be involved in the negative regulation of Src activity. The association of MT1-MMP with phosphorylated caveolin-1 occurs in caveolae membranes and involves the cytoplasmic domain of MT1-MMP because it was markedly reduced by mutation of Cys574 and Val582 residues of the cytoplasmic tail of the enzyme. Most interestingly, the reduction of the interaction between MT1-MMP and caveolin-1 by using these mutants also decreases MT1-MMP-dependent cell locomotion. Overall these results indicate that MT1-MMP associates with tyrosine-phosphorylated caveolin-1 and that this complex may play an important role in MT1-MMP regulation and function.
 ...
PMID:Src-mediated tyrosine phosphorylation of caveolin-1 induces its association with membrane type 1 matrix metalloproteinase. 1546 65

Although matrilysin (MMP-7) is overexpressed in various malignancies, few studies have evaluated its role in epithelial ovarian cancer (EOC) invasion and metastasis. We report that the secretion of MMP-7 in EOC is stimulated significantly by vascular endothelial growth factor (VEGF) and interlukin-8 (IL-8). We also examined the in vivo expression of MMP-7 in EOC and its effects on the in vitro invasion and progelatinase activation. We report that MMP-7 is overexpressed in ovarian cancer cell lines and EOC surgical specimens. DOV13 cells incubated with active rhMMP-7 significantly increased cellular invasion and proMMP-2 activation. RhMMP-7 also showed the ability to activate proMMP-2 and proMMP-9 in immortalized ovarian epithelial cell (IOSE-29) conditioned medium. In addition, rhMMP-7 was able to activate progelatinase in a concentration-dependent manner in vitro. TIMP-2 or the generic MMP inhibitor-GM6001 inhibited both the activation of proMMP-2 and the increased invasion of DOV13 cells promoted by rhMMP-7. By incubation of MMP2-TIMP-2 complex with equal molar rhMMP-7, MMP-2 was dissociated from the complex and activated in a time-dependent manner, suggesting that TIMP-2 helps to keep the latency of MMP-2. TIMP-2 also showed inhibitory effects on the MMP-7 induced increase of gelatinolytic activity in DOV13 and IOSE-29 conditioned media. A strong co-localization of MMP-7 and MMP-2 was observed in DOV13 cells and ovarian carcinoma permanent tissue sections. These results indicate MMP-7 is overexpressed in malignant ovarian epithelium and suggest MMP-7 may facilitate tumor cell invasion in vivo partly through the induction of progelatinase activation.
 ...
PMID:Matrilysin (MMP-7) promotes invasion of ovarian cancer cells by activation of progelatinase. 1552 95

The Runx2 (Cbfa1/AML3) transcription factor and matrix metalloproteinase 9 (MMP9) are key regulators of growth plate maturation and bone formation. The genes for both proteins are characteristic markers of breast and prostate cancer cells that metastasize to bone. Here we experimentally addressed the compelling question of whether Runx2 and MMP are functionally linked. By cDNA expression array analysis, we identified MMP9 as a novel downstream target of Runx2. Like that of MMP13, MMP9 expression is nearly depleted in Runx2 mutant mice. Chromatin immunoprecipitation and electrophoretic mobility shift assays revealed the recruitment of Runx2 to the MMP9 promoter. We show by mutational analysis that the Runx2 site mediates transactivation of the MMP9 promoter in osteoblasts (MC3T3-E1) and nonosseous (HeLa) cells. The overexpression of Runx2 by adenovirus delivery in nonmetastatic (MCF-7) and metastatic breast (MDA-MB-231) and prostate (PC3) cancer cell lines significantly increases the endogenous levels of MMP9. The knockdown of Runx2 by RNA interference decreases MMP9 expression, as well as that of other Runx2 target genes, including the genes for MMP13 and vascular endothelial growth factor. Importantly, we have demonstrated using a cell invasion assay that Runx2-regulated MMP9 levels are functionally related to the invasion properties of cancer cells. These results are consistent with Runx2 control of multiple genes that contribute to the metastatic properties of cancer cells and their activity in the bone microenvironment.
 ...
PMID:The Runx2 osteogenic transcription factor regulates matrix metalloproteinase 9 in bone metastatic cancer cells and controls cell invasion. 1616 39

We subcloned cell lines from SW620 cells establishing that, despite the dynamic nature of the mitochondrial membrane potential (Deltapsim), there are significant and stable differences in the intrinsic Deltapsim among cells within an in vitro population of human colonic carcinoma cells. Whereas more dramatic differences in Deltapsim would likely perturb essential mitochondrial functions, the differences in Deltapsim of the subclones did not affect steady-state reactive oxygen species levels, electron transport activity, or cellular viability and growth rates. However, the differences in intrinsic Deltapsim had a significant effect on the tumorigenic behavior of the cells. Subcloned cell lines with higher Deltapsim were more likely to exhibit elevated steady-state levels of vascular endothelial growth factor and matrix metalloproteinase 7, and increased invasive behavior (properties associated with tumor progression), than cells with lower intrinsic Deltapsim, whereas cells with lower Deltapsim were more likely to respond to the chemopreventive activities of butyrate, including Deltapsim dissipation, growth arrest, and apoptosis, than cells with higher Deltapsim. Therefore, these data establish that the probability for tumor development and progression is linked to stable differences in the intrinsic Deltapsim of colonic epithelial cells.
 ...
PMID:The intrinsic mitochondrial membrane potential of colonic carcinoma cells is linked to the probability of tumor progression. 1626 9

ADAMs (a disintegrin and metalloproteinases) comprise a new gene family of metalloproteinases, and may play roles in cell-cell interaction, cell migration, signal transduction, shedding of membrane-anchored proteins and degradation of extracellular matrix. We screened the mRNA expression of 10 different ADAMs with a putative metalloproteinase motif in synovial tissues from patients with rheumatoid arthritis (RA) or osteoarthritis (OA). Reverse transcription PCR and real-time quantitative PCR analyses indicated that among the ADAMs, ADAM15 mRNA was more frequently expressed in the RA samples and its expression level was significantly 3.8-fold higher in RA than in OA (p < 0.01). In situ hybridization, immunohistochemistry and immunoblotting demonstrated that ADAM15 is expressed in active and precursor forms in the synovial lining cells, endothelial cells of blood vessels and macrophage-like cells in the sublining layer of RA synovium. There was a direct correlation between ADAM15 mRNA expression levels and vascular density in the synovial tissues (r = 0.907, p < 0.001; n = 20). ADAM15 was constitutively expressed in RA synovial fibroblasts and human umbilical vein endothelial cells (HUVECs), and the expression level was increased in HUVECs by treatment with vascular endothelial growth factor (VEGF)165. On the other hand, ADAM15 expression in RA synovial fibroblasts was enhanced with VEGF165 only if vascular endothelial growth factor receptor (VEGFR)-2 expression was induced by treatment with tumor necrosis factor-alpha, and the expression was blocked with SU1498, a specific inhibitor of VEGFR-2. These data demonstrate that ADAM15 is overexpressed in RA synovium and its expression is up-regulated by the action of VEGF165 through VEGFR-2, and suggest the possibility that ADAM15 is involved in angiogenesis in RA synovium.
 ...
PMID:Expression of ADAM15 in rheumatoid synovium: up-regulation by vascular endothelial growth factor and possible implications for angiogenesis. 1627 68

Tears in the peripheral part of the menisci have a better healing potential than tears in the central part, because the central two-thirds of the menisci are avascular. The avascular status of the meniscus is maintained by the expression of antiangiogenic factors such as endostatin. The distribution of endostatin in the menisci correlates with the degree of vascularization. Endostatin immunostaining is strong in the avascular zone and reduced in the vascularized outer one-third. Endostatin interacts with signal transduction of the vascular endothelial growth factor (VEGF) by reducing VEGF-induced kinase (Erk1/2) phosphorylation. VEGF plays an important role in angiogenesis in fetal menisci and it is down-regulated in the adult meniscus. We hypothesized that healing of meniscal tears in the avascular zone can be promoted by the local application of the angiogenic factor VEGF. To evaluate this hypothesis a tear was created in the avascular zone of the medial meniscus in 18 merino sheep. The tear was then repaired with an uncoated suture (group 1), a suture coated with PDLLA (group 2), and by a suture coated with PDLLA/VEGF (group 3). After 6 weeks we observed increased factor VIII immunostaining in the VEGF-treated group. However, in this treatment group (VEGF/PDLLA) no meniscus healed. In the uncoated suture group and in the PDLLA-coated suture group partial healing was observed in three animals and complete healing in three animals, respectively. Factor VIII expression is normally restricted to vascular endothelial cells. In this study, however, single endothelial cells could be detected in the menisci of the VEGF/PDLLA group. This finding suggests that the application of VEGF might have stimulated proliferation of vascular endothelial cells but the application of VEGF was not successful in stimulating the more complex process of vasculogenesis. Further immunohistochemical examinations of the specimen have shown that in the VEGF/PDLLA group there is strong immunostaining against matrix metalloproteinase 13 (MMP-13). In vitro studies have shown that VEGF can stimulate chondrocytes to proliferate but also to express MMP-13 via HIF1-alpha induction. Since meniscal fibrochondrocytes express the VEGF receptor 2 (KDR) the induction of MMP expression might be another factor which inhibits healing despite increased angiogenesis. In conclusion, the local application of VEGF via PDLLA-coated sutures does not promote meniscal healing. A single growth factor might not always be a promising tool for the promotion of tissue repair. Further studies have to find out if growth factor combinations (VEGF and angiopoitin) might be more effective in stimulating vasculogenesis during meniscal healing.
 ...
PMID:Locally applied angiogenic factors--a new therapeutic tool for meniscal repair. 1632 Aug 30


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