Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.24.17 (MMP-3)
 3,419 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Primary cultures of adherent rheumatoid synovial cells (ASC) are comprised of variable proportions of fibroblasts, macrophages and stellate cells (activated fibroblasts). These cultures were shown to produce the metalloproteinases stromelysin-1 (MMP-3), gelatinase A (MMP-2) and gelatinase B (MMP-9) by Western blotting and zymography techniques. Immunolocalisation studies showed that MMP-3 was mainly produced by the fibroblastic cells whereas MMP-9 was restricted to macrophages (CD68 positive). Subcultured synovial fibroblasts, devoid of macrophages, did not produce MMP-9 as judged by zymography and immunolocalisation; but when stimulated with phorbol myristate acetate and interleukin-1 alpha both MMP-9 and MMP-3 were co-expressed. These 'activated' fibroblasts assumed a dendritic or stellate morphology, which in localisation studies was usually associated with enhanced enzyme production. Immunolocalisation studies of rheumatoid synovial tissue showed that relatively few cells were positive for MMP-3 and MMP-9. Localisation of MMP-9 corresponded to a proportion of macrophages positive for the CD68 marker throughout the synovial tissue. MMP-3 localisation was not associated with the macrophage marker, but was observed in both the synovial lining layer and deeper stromal locations. Widespread distribution of both enzymes was not observed in fresh tissues, but this increased in tissues subjected to short-term explant cultures. Thus, both in vitro and in vivo studies indicated that synovial fibroblasts or B-cells are effective producers of MMP-3 whereas macrophages elaborate MMP-9, observations that demonstrated different metalloproteinase phenotypes under similar environmental conditions.
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PMID:Differential expression of gelatinase B (MMP-9) and stromelysin-1 (MMP-3) by rheumatoid synovial cells in vitro and in vivo. 835 91

We developed a reconstruction culture system simulating human synovium to investigate the synoviocytes in a more physiological condition. This system with two types of dishes provided the two separated spaces corresponding to the joint cavity and nutrient vessels. The isolated normal synoviocytes were cultured in type-I collagen gel with a layer-seeded on top in a smaller inner dish with a porous bottom, which was placed in a larger outer dish. We added hyaluronic acid solution to the space on the gel to make an environment close to the physiological joint cavity. The space between the inner and outer dishes was filled with a complete medium to nourish the synoviocytes through the porous filter (Experiment 1). In addition, to examine cell-to-cell interaction, we created a co-culture model by mixing synoviocytes and peripheral blood mononuclear cells in the collagen gel matrix (Experiment 2). In this way we could reconstruct the synovium in vitro. The synoviocytes could survive and maintain their characteristics for four weeks of culture. In Experiment 1, almost all the cells were similar to type B synovial cells by histological, immunohistochemical and electron microscopic observations. In Experiment 2, the spherical cells in abundance of lysosomes like type A synovial cells appeared sporadically in the lining layer. Immunohistochemically, the majority of cultured cells expressed CD68 and matrix metalloproteinase 3. This culture system promises to be of use in investigating the pathogenesis of various joint diseases.
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PMID:Reconstruction culture system simulating human synovium: a three-dimensional collagen gel culture of synoviocytes. 936 18

A specialized subset of invasive embryonic cytotrophoblast cells gains access to maternal uterine arteries early in the gestation of higher primates. These cells continue to migrate extensively within the lumina of spiral arteries, converting them to the highly modified uteroplacental arteries of pregnancy. Although trophoblast cell-mediated modifications are considered critical to the progress of normal pregnancy, few studies have addressed the cellular interactions between maternal arteries and embryonic cells in situ. Macaque placentas and endometrial tissues were collected from 12 animals from day 14 of gestation (blastocyst implantation begins on day 9) to day 49. Standard indirect immunoperoxidase methods were used to identify matrix metalloproteinases (MMP-1, MMP-3, MMP-9), cathepsin B, cathepsin D, platelet-endothelial cell adhesion molecule, cytokeratins, smooth muscle actin, CD68, and factor VIII-related antigen. Cytotrophoblast cells were located deep within spiral arteries in each of the specimens examined. In some examples tightly packed clusters of cytotrophoblast occluded the lumina of invaded arteries. Initial penetration of arterial tunica intima was revealed by discontinuities in the staining pattern for factor VIII and cytotrophoblast intrusion was indicated by cytokeratin staining of the trophoblast cells. Continued cytotrophoblast intrusion into the tunica media was apparent by gaps in the smooth muscle. MMP-1, MMP-3, and MMP-9 were localized within intraluminal and intramural cytotrophoblast. By contrast, neither cathepsin B nor cathepsin D were present, although both were seen in uterine macrophages and stromal cells. Upon reaching the surrounding uterine stroma the cytotrophoblast cells ceased migration. As cytotrophoblast accumulated in the arterial wall the vascular lumen expanded. Evidence of cell death was rarely encountered in associated maternal or embryonic tissues. We conclude that intra-arterial cytotrophoblast cells express several proteinases with substrate specificities sufficient to permit independent remodeling of the extracellular matrix comprising uterine artery walls. The remodeling of the arteries, which involves extensive displacement of maternal endothelium and smooth muscle, in addition to degradation and synthesis of extracellular matrix, is accomplished with little evidence of cell death or loss of the integrity of the arteries. This process provides an interesting example of cooperation between different types of interacting tissues from genetically distinct individuals.
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PMID:Trophoblast cell-mediated modifications to uterine spiral arteries during early gestation in the macaque. 941 53

Monocytes/macrophages (Mo) appear to play a critical role in the initiation and progression of atherosclerotic lesions. In this study, we characterized in vitro-differentiated embryonic stem (ES) cell macrophages as a model system for studying atherosclerosis-associated Mo functions. Using immunofluorescence staining and Western analysis, we demonstrate that ES Mo express typical macrophage cell surface markers, as well as the known receptors for modified forms of low density lipoprotein (LDL), including the Mo scavenger receptors (SR-A type I and type II), CD36, and CD68. Differentiated ES Mo specifically bind and degrade 125I-labeled acetylated LDL with high affinity, and their incubation with acetylated LDL (15 microg/mL) for 48 hours produces characteristic "foamy" Mo, as visualized by oil red O staining. ES Mo also express matrix-degrading metalloproteinases (MMP-3, MMP-9), which have been implicated in collagen breakdown in the fibrous cap of atherosclerotic plaques, and secrete cytokines (tumor necrosis factor-alpha, interleukin-6) in response to inflammatory stimuli. Transfection experiments, using a green fluorescent protein reporter gene, driven by the myeloid-specific promoter, CD11b, demonstrated that ES Mo can also be used to study macrophage-restricted gene expression in vitro. Taken together, these data demonstrate that ES Mo exhibit many properties typical of arterial lesion macrophages. Its ease of genetic manipulation makes it an attractive system for investigations of macrophage functions in vitro.
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PMID:In vitro-differentiated embryonic stem cell macrophages: a model system for studying atherosclerosis-associated macrophage functions. 976 39

To investigate the distribution and potential participation of microglia, the resident defense cells of the central nervous system, in the optic nerve head (ONH) in glaucoma, histological paraffin sections of optic nerves from normal and glaucoma patients with mild to advanced nerve damage were studied using double labeling immunohistofluorescence. A monoclonal antibody for HLA-DR, indicating activated microglia, was colocalized with antibodies for functional proteins. In normal ONHs, microglia do not contain TGF-beta2, COX-2, or TNF-alpha and are not positive for PCNA; however, in glaucomatous ONHs, microglia contain abundant TGF-beta2, TNF-alpha, and PCNA. In glaucomatous eyes, a few microglia are usually positive for COX-2. In normal ONHs, there are rarely microglia containing TGF-beta1, NOS-2, TSP, TIMP-2, and CD68, but, in glaucomatous tissue, a few microglia are positive from the prelaminar to the postlaminar regions. MMP-1, MMP-2, MMP-3, and MMP-14 are constitutively present in the perivascular microglia in normal ONHs and appear to be more abundant in glaucomatous tissue. COX-1, TNF-R1, TIMP-1, and c-fms are constitutively present in normal tissues and appear to be increased in microglia in the glaucomatous ONHs. HSP27 is not present in microglia. In glaucomatous ONHs, microglia become activated and phagocytic and produce cytokines, mediators, and enzymes that can alter the extracellular matrix. Our findings suggest that activated microglia may participate in stabilizing the tissue early in the disease process, but, as the severity of the glaucomatous damage increases, the activities of microglia may have detrimental consequences for the pathological course of glaucomatous optic neuropathy.
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PMID:Activated microglia in the human glaucomatous optic nerve head. 1139 7

Neovascularization and invasion are key features of malignant gliomas. Matrix metalloproteinases (MMPs) are supposed to play a major role mediating these processes. To analyze the expression patterns of MMPs in microvascular human cerebral endothelial cells (HCEC), we isolated endothelial cells from normal human brain microvessels. Characterization of cellular origin was performed by immunostaining, using the endothelial cell markers Ulex europaeus Agglutinin-1, von-Willebrand-Factor and Glucose-transporter-1. Contamination by other cell types was tracked by immunohistochemistry for GFAP (astrocytes), ASM (pericytes) and CD68 (macrophages). Secretion of MMPs was evaluated by ELISA and zymography. To determine whether HCEC show any difference in MMP expression compared to endothelial cells of other origin we analyzed human umbilical vein endothelial cells (HUVEC). HCEC show a decrease of MMP-3 and MMP-2 protein when treated with SU5416, a VEGF-R2 (KDR/flk-1) inhibitor, whereas MMP expression remained unchanged in HUVEC. To determine whether these findings show any effect in the motility of these cells we used a three-dimensional co-culture assay of avascular glioblastoma spheroids with primary HCEC spheroids. Untreated controls showed invasion of both cell populations into each other whereas treatment of the co-cultures with SU5416 resulted in complete inhibition of endothelial cell invasion hence indicating that flk-1 related motility of endothelial cells is critically involved in this process and can be studied with this assay. The results of different effects of anti-angiogenic treatment on proteolytic properties of two endothelial cell populations suggest that neovascularization of human brain tumors in vitro is dependent on the surrounding endothelial cell type and should therefore be studied with organ-specific human microvascular cerebral endothelial cells.
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PMID:Influence of VEGF-R2 inhibition on MMP secretion and motility of microvascular human cerebral endothelial cells (HCEC). 1277 73