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

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Query: EC:3.4.24.3 (collagenase)
18,340 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Epidermal growth factor and cartilage-derived basic fibroblast growth factor (EGF and CD-bFGF) are mitogens shown to increase the rate of wound repair in animal models. In addition to being a mitogen for granulation tissue, CD-bFGF stimulates the recruitment of cells to the wound site. CD-bFGF and a closely-related chondrosarcoma-derived fibroblast growth factor stimulated chemotaxis of granulation tissue cells in vitro, each factor having a maximum activity at a concentration of 55 pM. Epidermal growth factor was also a potent chemoattractant for rat granulation tissue fibroblasts; however, maximum activity was obtained at 1.7 nM. Cells from all stages of wound repair were chemotactically responsive to these factors, but there was some attenuation of the response to bFGF in cells derived from fully-organized day 28 granulation tissue. Collagenase-catalyzed restructuring of collagen, an additional significant feature of wound repair, is probably critical to cell movement in an extracellular matrix. Cells derived from organizing (6-day old) sponge granulation tissue secreted latent collagenase constitutively in vitro. In the presence of serum, the production of collagenase was stimulated three-four fold by 1.8 nM bFGF derived either from cartilage or chondrosarcoma. When serum was present, as at a wound site, collagenase production was not enhanced by the addition of EGF. Cells from fully organized, day 21 sponge granulation tissue did not secrete latent collagenase constitutively and could not be stimulated to do so by the addition of EGF, bFGF, or phorbol ester. Human skin fibroblast collagenase production was also stimulated by bFGF and was refractory to EGF. While both classes of growth factor have the ability to promote wound healing, the varying responses they elicit in cell populations from the wound site emphasize the different pathways of cellular activation.
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PMID:Differential stimulation of collagenase and chemotactic activity in fibroblasts derived from rat wound repair tissue and human skin by growth factors. 253 37

Swarm rat chondrosarcoma chondrocytes produce an inhibitor of collagenase similar to that found in bovine articular chondrocytes and extracts of bovine scapular cartilage. These cells synthesize normal levels of cartilage type proteoglycans when cultured in serum free medium with insulin. Collagen synthesis is also increased when insulin is added to chondrosarcoma chondrocytes. We have demonstrated that insulin stimulates collagenase inhibitor production by these chondrocytes. Enhancement of inhibitory activity occurs over the range of 10 to 1000 ng/ml. A 3.2 fold stimulation was observed at a concentration of 1 microgram/ml. There was a lag period of 24 to 48 hours before the insulin effect became evident. Latent or active collagenase was not detectable under these conditions. These results suggest that the hormone insulin controls the levels of collagen in this tumor by stimulating synthesis of collagen and inhibitors of collagenase.
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PMID:Insulin stimulates secretion of a collagenase inhibitor by Swarm rat chondrosarcoma chondrocytes. 282 Apr 7

Cells from a rat chondrosarcoma in primary suspension culture were used for labeling studies and isolation of RNA. With extended labeling, a distinct fraction of poly(A+)RNA sedimented in the region of 26S on denaturing sucrose gradients. Similar profiles were obtained with labeled poly(A+)RNA isolated from normal cartilage tissues, as well as from chondrocytes in culture. This mRNA coded for collagenous protein when translated in a cell-free system derived from wheat germ. Among the polypeptides synthesized in vitro, one distinctive component of approximately 150,000 daltons was detected by gel electrophoresis. Polypeptides of identical size, sensitive to bacterial collagenase, were also synthesized in vitro by polysomes isolated from the chondrosarcoma.
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PMID:Partial characterization of procollagen messenger ribonucleic acid in a murine chondrosarcoma. 615 97

Type II procollagen messenger ribonucleic acid (mRNA) was isolated from chick sternum and rat chondrosarcoma cells and translated in a reticulocyte lysate cell-free system. A high molecular weight band was identified as type II procollagen by gel electrophoresis, collagenase digestion, and specific immunoprecipitation. The translation of type II mRNA was specifically inhibited by addition of type I procollagen amino-terminal extension peptide. When this peptide was added to the media of cultured fetal calf chondrocytes, chick sternal chondrocytes, or chick tendon fibroblasts, no inhibition of collagen synthesis was evident. These data suggest a general regulation of collagen biosynthesis by these peptides in the cell-free translation system. However, as indicated by the cell culture experiments, cellular characteristics and evolutionary divergence of animal species seem to restrict the effect of the peptides.
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PMID:Effects of procollagen peptides on the translation of type II collagen messenger ribonucleic acid and on collagen biosynthesis in chondrocytes. 626 56

Polysomes were isolated from calcified and matrix-containing tissues, such as rat calvaria, rat chondrosarcoma and chick embryos. The method of isolation involves preliminary swelling of the tissues in hypotonic buffer containing heparin and cycloheximide. After homogenization, differential centrifugation is used to separate membrane-bound and non-bound polysomes. Each fraction is rehomogenized in the presence of detergent (Triton X-100) and potassium ions (0.25M). Polysomes are harvested by centrifugation through sucrose cushions in the continued presence of high levels of potassium ions and heparin. Total, non-bound, and membrane-bound polysomes prepared in this manner are equally active in protein synthesizing activity in an heterologous cell-free system. The distribution between non-bound and membrane-bound polysomes in the 12 day old chick embryo is 43 and 57 per cent respectively. Sucrose gradient profiles of polypeptide chains on polysomes labeled in organ culture correlate well with the protein synthetic activity of the isolated polysomes. Much of the protein synthetic activity is devoted to collagen. Polysomal fractions obtained from sucrose gradients show preferential incorporation of 3H-proline and nearly 60 per cent of trichloroacetic acid precipitable material is susceptible to collagenase digestion. Products of synthesis are also substrates for collagen specific enzyme, prolyl hydroxylase. The method described in this communication overcomes the inherent difficulties in obtaining active polysomes from calcified and matrix-containing tissues.
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PMID:Isolation and partial characterization of active polysomes from calcified and matrix-containing tissues. 627 Oct 84

The anabolic effects of insulin on collagen production of freshly isolated Swarm rat chondrosarcoma chondrocytes were investigated. The specific radioactivity of newly synthesized collagen was not increased by insulin, indicating that the hormone has no effect on the specific radioactivity of the aminoacyl tRNA pool. Results of further studies obtained from collagen degradation experiments demonstrated that insulin did not alter the rate of [3H]collagen degradation. Together, these results clearly indicate that insulin stimulates collagen biosynthesis. Polyacrylamide gel analysis of the newly synthesized collagen of both control and insulin-stimulated cells revealed a large-molecular-weight component which migrated with authentic alpha 1(II) collagen and was collagenase-sensitive. Additional studies showed that, although insulin increased the processing and secretion of collagen, the hormone did not cause a shift in the distribution of the extracellular and intracellular collagen pools. Finally, results of studies conducted with the transcriptional inhibitor, actinomycin D, indicated that the anabolic effects of insulin on collagen and non-collagen proteins were mediated at a post-transcriptional site.
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PMID:The anabolic effects of insulin on type II collagen synthesis of Swarm rat chondrosarcoma chondrocytes. 638 Apr 13

Protein synthesis by human chondrosarcoma tissue and normal articular cartilage was studied in organ and primary monolayer cell culture systems. Protein synthesis by cell cultures was evaluated at 2.7 and 21 days after plating. When compared to normal, incorporation of 3H-proline and 35S-methionine into proteins was elevated in chondrosarcoma samples under both culture conditions. Hydroxyproline analyses of tissue hydrolysates indicated that chondrosarcoma samples contained significantly less collagen than normal articular cartilage, yet were incorporating significantly greater amounts of 3H-proline into 3H-hydroxyproline. Collagen production by cell cultures was assessed by digestion of samples with purified clostridial collagenase. Chondrosarcoma cells produced more collagenase-sensitive protein than normal cells at all intervals. SDS polyacrylamide gel analyses of all preparations showed two collagenase-sensitive proteins with apparent molecular weights of 165,000 and 175,000. Decreased synthesis of another major protein, apparent molecular weight 210-220,000 was noted in chondrosarcoma preparations in both culture systems.
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PMID:De novo protein synthesis by human chondrosarcoma in cell and organ culture: evidence of unusually high collagen production by a neoplastic tissue. 645 Jun 65

When chondrocytes from the Swarm rat chondrosarcoma are isolated by trypsin and collagenase digestion and cultured in Petri dishes, they form a new extracellular matrix within 24 hours, with proteoglycan matrix granules and collagen fibrils. This rapid synthesis of new matrix, together with the biochemical and morphological characterization of the proteoglycans as typical of cartilage, demonstrates the value of these cultures as a model system for studies of synthesis, secretion, and organization of extracellular matrix.
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PMID:The ultrastructure of cultures from the Swarm rat chondrosarcoma. 727 Sep 28

Monoclonal antibodies have been prepared that react specifically with the neoepitopes present on proteoglycan degradation products generated from the proteolytic cleavage of aggrecan in the interglobular domain. Antibody BC-3 recognizes the new N-terminus (ARGSV...) on aggrecan degradation products produced by the action of the as yet uncharacterized proteolytic activity, 'aggrecanase', and antibody BC-4 recognizes the new C-terminus (...DIPEN) generated by the proteolytic action of matrix metalloproteinases. Specificity for these neoepitope sequences was determined in competitive e.l.i.s.a. using synthetic peptide antigens as inhibitors. Antibody BC-3 was used in the detection of aggrecan degradation products in the culture medium obtained from two different in vitro culture systems: bovine cartilage explants treated with either retinoic acid or interleukin-1, and secondly, rat chondrosarcoma cells treated with retinoic acid. Both interleukin-1 and retinoic acid treatment caused an increase in aggrecan catabolism resulting in an increased release to the medium of specific aggrecan degradation products containing the BC-3 neoepitope generated by the action of 'aggrecanase'. However, several additional aggrecan catabolites were present that were not immunoreactive with antibody BC-3. In addition, under control conditions, in the bovine cartilage cultures the BC-3 epitope was found on some of these aggrecan catabolites. In contrast, no immune-reactive material was found in the aggrecan degradation products present in control media of rat chondrosarcoma cells cultured in the absence of retinoic acid. Collectively, these results demonstrate that 'aggrecanase' activity is not a constitutive event in all cartilage culture systems and also suggest that proteolytic agents other than 'aggrecanase' are involved in aggrecan catabolism in normal turnover compared with pathological conditions. Antibody BC-4 was used to demonstrate the identity of the G1 domain of aggrecan following proteolytic cleavage of a purified G1-G2 preparation with collagenase, gelatinase A or stromelysin. The G2 product of this cleavage did not react with antibody BC-3, indicating that, under the experimental conditions used, none of these enzymes exhibited 'aggrecanase' activity. It is expected that both of these antibodies will play a pivotal role in detailed studies elucidating molecular mechanisms of aggrecan degradation and they will be particularly useful for the sensitive monitoring of aggrecan degradation products in tissue extracts and body fluids.
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PMID:Monoclonal antibodies that specifically recognize neoepitope sequences generated by 'aggrecanase' and matrix metalloproteinase cleavage of aggrecan: application to catabolism in situ and in vitro. 753 36

The biosynthesis of type XI and type II collagens was examined using a stable rat chondrocyte cell line established by W. E. Horton et al. (1988, Exp. Cell Res. 178, 457-468.). These cells (IRC; immortalized rat chondrocytes) were created by transformation with a murine retrovirus carrying the v-myc and v-raf oncogenes. They grow in suspension culture as multicellular aggregates and synthesize typical cartilage proteins, aggrecan and link protein. Type II collagen is absent or synthesized at severely reduced levels, as shown by Northern analysis of mRNA. Thus, this cell type represents a unique model in which to study cartilage matrix protein interactions in the absence of type II collagen. A more detailed look at the proteins secreted into the medium by metabolically labeled IRC cells revealed the presence of collagenase-sensitive bands when analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The bands were identified as the alpha 1, alpha 2, and alpha 3 chains of heterotrimeric type XI collagen by electrophoretic migration after pepsin digestion, by CNBr peptide mapping, and by immunoprecipitation with antibodies to rat alpha 1(XI). mRNA for all three chains was detected by Northern blot analysis. The data indicate that the low level of alpha 1(II) mRNA previously detected in these cells is translated into pro alpha 3(XI) polypeptide chains which are incorporated into molecules of type XI. Under normal culture conditions, homotrimers of type II collagen were not detected. The carboxyl propeptide domain of the fibrillar collagens directs chain selection and molecular assembly of the trimeric molecules. The sequence of the carboxyl propeptide domain from pro alpha 3(XI) of IRC cells was found to be identical to this domain from pro alpha 1(II) of swarm rat chondrosarcoma, supporting previous evidence that pro alpha 3(XI) and pro alpha 1(II) have the same primary structure. When cultured in the presence of 50 mM arginine, IRC cells could be induced to synthesize pro alpha 1(II) chains in excess over pro alpha 1(XI) and pro alpha 2(XI). Only under these conditions were type II collagen molecules detected, suggesting a preferential association of pro alpha 1(II) with the pro alpha 1 and/or pro alpha 2 chains of type XI collagen.
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PMID:Characterization of type II and type XI collagen synthesis by an immortalized rat chondrocyte cell line (IRC) having a low level of type II collagen mRNA expression. 802 Jun


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