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)

Early steps in the biosynthesis of chondroitin sulfate proteoglycan (CSPG) and collagenous cartilage matrix molecules were examined by the comparison of products translated in mRNA-directed cell-free reactions and those synthesized by intact cartilage cells. RNA isolated from embryonic chicken sterna was used to direct cell-free translation reactions. Chicken sternal chondrocytes in culture were pulse-labeled with [35S]-methionine. The CSPG core protein was identified by immunoprecipitation. The Mr of the cartilage cell-synthetized core protein was determined to be 370K, approximately 10-15K greater than that of the comparable cell-free translation product. Experimental results strongly support the view that the observed difference in Mr reflects the cotranslational addition of mannose-rich, N-asparagine-linked oligosaccharides to the cell-synthesized core protein: 1) the cell-synthesized product was labeled with [3H]-mannose and precipitated by concanavalin A-sepharose beads; 2) the incorporated [3H]-mannose could be subsequently removed by digestion with endoglycosidase H (Endo H); 3) the Mr of the cell-synthesized core protein was reduced by Endo H digestion to that of the comparable cell-free translation product; 4) the core protein synthesized by tunicamycin-treated chondrocytes (inhibited in their ability to add N-asparagine-linked mannose-rich oligosaccharides to proteins) was comparable in electrophoretic mobility to that of the core protein cell-free translation product; and 5) the core protein translated in microsome-coupled cell-free reactions had an Mr 8-10K greater than that of the core protein translated in the absence of microsomes. For the purpose of examining biosynthetic intermediates, chondrocytes were labeled continuously or pulse-chase labeled for varying times. No biosynthetic CSPG intermediates migrating between the core protein and the CSPG monomer were detected. However, a band of 355Kdal appeared to share certain characteristics with the 307Kdal core protein (including its immunoprecipitability with CSPG antibodies), and a 340Kdal band was noted. Type II procollagen and other collagenase-sensitive products of 205Kdal and 110Kdal were observed among translation and chondrocyte-synthesized products. In chondrocytes, all three products exhibited labeling or chase time-dependent increases in Mr which were accelerated by ascorbate supplements and inhibited by the addition of alpha, alpha'-dipyridyl. These results suggest that the observed time-dependent increases in Mr are a consequence of collagen hydroxylation. The 110Kdal and 205Kdal collagenous proteins may be related to the minor collagens recently described in cartilage.
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PMID:Biosynthetic precursors of cartilage chondroitin sulfate proteoglycan. 330 Nov 84

We established culture lines derived from the subendothelial region of the porcine aortic valve. These cells were isolated by extensive collagenase digestion of valvular tissue and were serially propagated with stable morphology. In sparse culture, valve subendothelial cells resembled skin fibroblasts. When confluent, the valve subendothelial cells formed ridges and piles similar to vascular smooth muscle cells. Endogenous in vitro labeling experiments using 35S-methionine showed that valve subendothelial cells synthesized and released several proteins not observed in parallel experiments using porcine skin fibroblasts and smooth muscle cells. Mitogen assays using media conditioned by porcine aortic valvular endothelial cells showed that the valve subendothelial cells, when compared to skin fibroblasts and smooth muscle cells, were particularly avid responders to the growth factors released by valve endothelial cells in vitro. The valve subendothelial cells also released 10-fold more prostacyclin in response to arachidonate than did skin fibroblasts or smooth muscle cells. We conclude that valve subendothelial cells show features that distinguish them from other cultured mesenchymal cells, and that this culture system will be useful for studies of the cellular basis of valvular heart disease.
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PMID:Porcine cardiac valvular subendothelial cells in culture: cell isolation and growth characteristics. 332 49

Periportal and perivenous hepatocytes were isolated by the digitonin-collagenase perfusion technique. The activity of the cytosolic glutathione S-transferase was higher in perivenous cells, but the cytosolic glutathione reductase and the microsomal glutathione S-transferase activities were evenly distributed. In contrast, both the Se-dependent and the microsomal Se-independent glutathione peroxidase activity and the glucose-6-phosphate dehydrogenase activity was much lower in perivenous hepatocytes, suggesting that these cells have a lowered detoxification capacity, which may contribute to their greater susceptibility to damage by xenobiotics. The mechanism of the ethanol-induced GSH depletion in vivo was studied by incubating conventionally isolated hepatocytes. In the absence of glutathione precursors, ethanol (80 mM) did not influence the GSH content, despite accumulation of acetaldehyde (10-100 MicroM). L-Methionine or L-cysteine stimulated GSH replenishment to in vivo rates. Ethanol oxidation resulted in acetaldehyde accumulation, but did not inhibit GSH replenishment from L-methionine and even stimulated that from L-cysteine. This seems to exclude conjugation of GSH with acetaldehyde as a mechanism by which ethanol suppresses GSH levels in vivo.
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PMID:Glutathione metabolism in isolated rat hepatocytes: acinar heterogeneity of detoxifying enzymes and effects of ethanol. 342 86

The addition of highly purified elastic fibers to confluent human skin fibroblast or porcine aorta smooth muscle cell cultures resulted in a time-dependent, strong adhesion of the fibrils to the cell surface. The kinetics of adhesion was studied by video/time-lapse cinematography. After a 0.5-1 hr lag period, adhesion progressed to a maximum amount in 3-6 hr in the described conditions. Adhesion is strongly accelerated by the prior addition of soluble elastin peptides (kappa-elastin) to the cultures. Cycloheximide inhibits this induced adhesion. Adherent elastic fibers can be detached by treatment with elastase and trypsin but not with collagenase. The radioactive proteins adhering to elastic fibers, after a 6-hr incubation of the induced cultures in presence of [35S]methionine, were extracted and analyzed by NaDodSO4/PAGE. The proteins strongly adhering to the elastic fibers had apparent molecular sizes of about 120, 67, 60, and 45 kDa. Only the 120-kDa protein band showed a significant increase of its associated radioactivity in the induced cultures as compared to the noninduced cultures. We propose that the 120-kDa protein is responsible for the induced adhesion of mesenchymal cells to elastic fibers and designate it "elastonectin."
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PMID:Inducible adhesion of mesenchymal cells to elastic fibers: elastonectin. 346 47

We studied the effect of a progestin (R5020) on proteins released by stromal and epithelial endometrial cells in primary culture. Stromal and epithelial cells was isolated by collagenase and hyaluronidase digestion of endometrial tissue. The synthesis of proteins released into the cell culture medium was assayed by [35S]methionine incorporation and sodium dodecyl sulfate-polyacrylamide gel electrophoresis, followed by fluorography. The relative proportions of individual proteins secreted by stromal and epithelial cells varied. However, 29K, 128K, and 150K proteins were more abundant in media from epithelial cell cultures, whereas 60K and 70K proteins were more abundant in media from stromal cell cultures. More proteins were secreted by cells obtained in the luteal phase than by those obtained in the proliferative phase. R5020 consistently stimulated the synthesis of a minor protein of 51,000 mol wt secreted by both epithelial and stromal cells. Physiological concentrations of dexamethasone, dihydrotestosterone, or estradiol did not stimulate synthesis of the 51K protein. The effect of R5020 was concentration dependent; maximal synthesis occurred with 10 nM R5020 and 4 days of treatment. This 51K protein is different from the estrogen-regulated 52K protein of breast cancers. These results indicate that cultured endometrial cells can synthesize and release a variety of proteins in vitro. One of them, the 51K protein, is a marker of responsiveness to progestin.
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PMID:A 51K progestin-regulated protein secreted by human endometrial cells in primary culture. 357 30

The parent R3230 AC rat mammary carcinoma cell line and the two variant cell lines, R3230 AC MET and R3230 AC LR, differ with respect to their abilities to invade bony matrices and to form lung colonies (experimental metastases). Both the R3230 AC and the R3230 AC MET, a cell line selected in vivo for enhanced metastatic capability, express high potentials for invasiveness and lung colony formation, while the Con A- and WGA-resistant R3230 AC LR cell line grows expansively at the periosseus implantation site and is unable to form lung colonies after intravenous inoculation. The abilities to invade bone and to metastasize to the lung are well correlated with the fibrinolytic activity and the production of urokinase-type plasminogen activators. The contribution of plasminogen activators to invasiveness and metastasis has been ascribed to its role in the fibrinolytic and collagenolytic (i.e., activation of latent collagenase) cascades.
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PMID:Correlation of fibrinolytic activity with invasion and metastasis of R3230 AC rat mammary carcinoma cell lines. 359 83

To evaluate the role of small amounts of prostatic tissue dihydrotestosterone (DHT) as a stimulus to epithelial cell protein synthesis, we studied tissue from 27 patients given various androgen-blocking drugs for 1 week before transurethral resection of the prostate (TURP) and measured epithelial protein synthesis and DHT levels in the tissue specimens. Test drugs before TURP included megestrol acetate 160 mg per day, with and without Tamoxifen 40 mg per day, or ketoconazole 1200 mg per day. The tissue was processed immediately and epithelial cells separated by digestion of tissue with 0.5% collagenase. After separation, epithelial cells were labelled with either 3H-leucine or L-35S-methionine. The DHT level was measured in whole prostatic tissue. Megestrol acetate alone and with tamoxifen significantly decreased both the incorporation of 3H-leucine into protein and the tissue concentration of DHT; megestrol acetate plus ketoconazole significantly decreased L-35S-methionine incorporation into protein and the DHT level. When the data correlating DHT with protein synthesis using both labelling techniques were combined, the curves were parallel and a strong correlation was noted between DHT and protein synthesis over a wide range of values (P less than 0.001). These results suggest that in hormone-dependent prostatic cancer even small amounts of prostatic DHT such as may occur from adrenal androgens following castration may significantly stimulate protein synthesis of the tumour epithelial cells.
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PMID:Relationship between human prostatic epithelial cell protein synthesis and tissue dihydrotestosterone level. 366 14

A rapid method to obtain large amounts of tubular gland cells from chick oviduct was developed. Combined collagenase and trypsin treatment allowed within 1.5 h complete dissociation of the magnum portion of the oviduct. By differential attachment of cells, fibroblasts were separated from tubular gland- and ciliated cells. Tubular gland cells attached within 18 h to plastic Petri dishes, had large secretory granules and grew very actively. The responsiveness of cells to hormones and/or antihormone was tested by measurement of cell proliferation and specific protein synthesis. After 7 days of culture in the presence of estradiol (50 nM) or progesterone (100 nM), cell growth was increased by approximately 50 and 35% respectively. Tamoxifen (100 nM) inhibited the estradiol induced growth stimulation, but had also negative effects of its own. The anti-progesterone (in mammals) RU 486, inactive per se, did not antagonize progesterone induced growth. Ovalbumin- and conalbumin synthesis after 4-5 days of cultures under different hormonal conditions was assessed after immunoprecipitation of newly synthesized [35S]methionine labelled proteins. In the presence of estradiol (50 and 100 nM), progesterone (50 nM), and both estradiol and progesterone together (50 nM of each), ovalbumin and conalbumin synthesis was increased, when compared to control cultures without hormones, or to oviduct fibroblasts. Hormonal stimulation of ovalbumin synthesis was also shown in cell supernatant and culture medium after gel electrophoresis.
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PMID:Steroid hormones induce cell proliferation and specific protein synthesis in primary chick oviduct cultures. 370 11

To study kinetics and principles of cellular uptake of 13N-ammonia, a marker of coronary perfusion in myocardial scintigraphy, heart muscle cells of adult rats were isolated by perfusion with collagenase and hyaluronidase. Net uptake of 13N, measured by flow dialysis, reached equilibrium within 20 sec in the presence of sodium bicarbonate and carbon dioxide (pH 7.4, 37 degrees C). Total extraction, 80 sec after the reaction start, was 786 +/- 159 mumol/ml cell volume. Cells destroyed by calcium overload were unable to extract 13N-ammonia. Omission of bicarbonate and carbon dioxide reduced total extraction to 36% of control. 13N-Ammonia uptake could also be reduced by 50 muM 4,4' diisothiocyanostilbene 2,2' disulfonic acid, by 100 micrograms/ml 1-methionine sulfoximine, and by preincubation with 5 muM free oleic acid. These results indicate that in addition to metabolic trapping by glutamine synthetase, the extraction of 13N-ammonia by myocardial cells is influenced by cell membrane integrity, intracellular-extracellular pH gradient, and possibly an anion exchange system for bicarbonate. For this reason, the uptake of 13N-ammonia may not always provide a valid measurement of myocardial perfusion.
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PMID:Kinetics of 13N-ammonia uptake in myocardial single cells indicating potential limitations in its applicability as a marker of myocardial blood flow. 396 79

A 140 K glycoprotein was detected in the culture media of human sarcoma and melanoma cell lines by labeling with several radioactive amino acid and sugar precursors, followed by sodium dodecylsulfate-polyacrylamide gel electrophoresis and fluorography. In contrast to this, in the culture media of metabolically labeled embryonic and skin fibroblasts this glycoprotein was not found. Likewise, a protein with an identical molecular weight of 140 K was also found in culture media after cell surface labeling of the neoplastic cells but not in the culture media from control cells. The [35S]methionine-labeled 140 K was not split by collagenase and did not appear to be a fragment of fibronectin. We discuss the possibility that secretion of the 140 K glycoprotein is a transformation-related phenomenon.
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PMID:Release of an Mr 140,000 glycoprotein in the culture media of certain human sarcoma and melanoma cell lines. 400 10


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