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

Pseudoxanthoma elasticum (PXE) is an inherited disease characterized by calcified degenerative changes of elastin in the skin, eye, and vasculature. Previous studies suggested the abnormal presence of a protease from PXE fibroblasts that degrades sulfated proteoglycans. This study describes the use of a radioassay to quantitate proteoglycan degradation by proteases from normal and PXE fibroblasts. PXE protease had optimal activity at pH 6.0. Inhibition of activity by 5 mM diisopropylfluorophosphate, 5 mM phenylmethylsulfonylfluoride, and 0.1 mM HgCl2 was reversed by 10 mM dithiothreitol. Iodoacetamide (1 mM) irreversibly inhibited activity. Carbobenzyloxy-phenylalanyl-alanyl (0.1 mM) and carbobenzyloxy-lysyl-diazomethyl ketone (10 microM) inhibited the proteoglycanase activity. These data suggest that the PXE proteolytic proteoglycanase activity is a cysteine protease. After blocking activity with 5 mM EDTA, addition of 10 mM Mg++, Mn++, Cu++, or Co++ had little effect (less than 10%) on restoring activity, 10 mM CaCl2 restored approximately 70% recovery of the activity, and 10 mM ZnCl2 stimulated the activity to 500% of the initial level. Similar normal fibroblast samples contained little zinc-dependent activity and a substantial amount of calcium-dependent activity. Thus the distinction between the divalent ion requirements for proteoglycan degradation suggests that the PXE fibroblasts may produce a different cysteine protease than do normal fibroblasts.
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PMID:Cysteine protease characteristics of the proteoglycanase activity from normal and pseudoxanthoma elasticum (PXE) fibroblasts. 635 May 11

Culture of articular chondrocytes in alginate beads offers several advantages over culture in monolayer; cells retain their phenotype for 8 months or longer. Earlier studies of chondrocytes cultured in alginate concentrated on collagen and proteoglycan synthesis. However, gene expression by in situ hybridization (ISH) has not been investigated. The purposes of the present study on human chondrocytes were (a) to modify the ISH procedure for the alginate beads to examine the mRNA expression of alpha1 (II) procollagen, aggrecan, and two matrix metalloproteinases (MMP-3 and MMP-8) thought to be involved in cartilage matrix degradation, and (b) to compare expression in cultured chondrocytes with that in chondrocytes of intact human cartilage. The modifications made for ISH include the presence of CaCl2 and BaCl2 in the fixation and washing steps and exclusion of cetyl pyridinium chloride. By ISH we show that aggrecan, MMP-3, and MMP-8 are continuously expressed during 8 months of culture. The alpha1 (II) procollagen gene is expressed only during the first 2 months of culture and after 3 months its expression is undetectable, which is consistent with its absence in adult articular cartilage. By Western blotting, Type II collagen protein had been synthesized and deposited in both the cell-associated and further-removed matrix compartments at 7 and 14 days of culture. These data indicate that chondrocytes cultured in alginate beads could be preserved for immunohistochemistry and ISH and that culture of human chondrocytes in alginate beads may serve as a good model for studying cartilage-specific phenotype as well as factors that influence cartilage matrix turnover.
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PMID:Gene expression by human articular chondrocytes cultured in alginate beads. 1156 Oct 5

This in vitro study investigated the metabolism of human osteoarthritic (OA) chondrocytes encapsulated in a spherical matrix enriched of chitosan. Human OA chondrocytes were encapsulated and cultured for 28 days either in chitosan-alginate beads or in alginate beads. The beads were formed by slowly passing dropwise either the chitosan 0.6%-alginate 1.2% or the alginate 1.2% solution through a syringe into a 102 mM CaCl2 solution. Beads were analyzed histologically after 28 days. Interleukin (IL)-6 and -8, prostaglandin (PG) E2, matrix metalloproteinases (MMPs), hyaluronan and aggrecan were quantified directly in the culture supernatant by specific ELISA and nitric oxide (NO) by using a colorimetric method based on the Griess reaction. Hematoxylin and eosin staining showed that chitosan was homogeneously distributed through the matrix and was in direct contact with chondrocytes. The production of IL-6, IL-8 and MMP-3 by chondrocytes significantly decreased in chitosan-alginate beads compared to alginate beads. PGE2 and NO decreased also significantly but only during the first three days of culture. Hyaluronan and aggrecan production tended to increase in chitosan-alginate beads after 28 days of culture. Chitosan-alginate beads reduced the production of inflammatory and catabolic mediators by OA chondrocytes and tended to stimulate the synthesis of cartilage matrix components. These particular effects indicate that chitosan-alginate beads are an interesting scaffold for chondrocytes encapsulation before transplantation to repair cartilage defects.
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PMID:Chitosan enriched three-dimensional matrix reduces inflammatory and catabolic mediators production by human chondrocytes. 2602 Jul 73