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)

In this paper the recognition of various rat tumor cells by rat liver cells is demonstrated in vitro. A liver cell receptor involved in the binding process has been identified. The ultrastructure of the cell contacts was examined by transmission electron microscopy. Hepatocytes and Kupffer cells were isolated from rat liver by collagenase treatment and cell adhesion tests were performed with 4 different tumor cells types. Hepatocytes were found to bind Walker sarcoma cells, lymphoma cells and Yoshida hepatoma cells but not leukemia 5222 cells. Kupffer cells bound all tumor cell types. Normal blood cells were not bound under the same conditions. Recognition of tumor cells by hepatocytes was mediated by a galactose specific lectin on the liver cell surface as shown by hapten inhibition experiments with specific saccharides. Although Kupffer cells express a similar lectin-like receptor adhesion of tumor cells could not or only slightly be inhibited by galactose or related saccharides. It is concluded that the spontaneous adhesion of tumor cells to liver cells in vitro is a specific recognition event which in part is mediated by lectin-carbohydrate interactions.
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PMID:Galactosyl specific receptor on liver cells: binding site for tumor cells. 728 63

Murine hepatocytes, isolated by an in situ collagenase-perfusion technique and cultured in Petri dishes, were shown to form rosettes with liver-metastasizing syngeneic tumor cells. Pretreatment of the tumor cells with neuraminidase generally increased the binding, whereas pretreatment of the liver cells with neuraminidase abolished the binding completely. The tumor-cell binding may be mediated by the previously described lectin-like receptor of hepatocytes that also was sensitive to neuraminidase treatment and that bound desialylated cells better than normal cells. Anti-H-2 sera could efficiently inhibit the rosette formation of metastatic tumor cells with the hepatocytes, which points to a possible role of H-2 molecules in this interaction of neoplastic and normal cells.
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PMID:Hepatocyte-tumor cell interaction in vitro. I. Conditions for rosette formation and inhibition by anti-H-2 antibody. 737 19

N-acetylglucosaminyltransferases III and V (GnT-III and -V) are key enzymes in the synthesis of the branches of asparagine-linked oligosaccharides. Although their messenger RNAs (mRNAs) are expressed in various rat tissues, they are not detected in normal rat liver. Expression of the GnT-III and -V mRNAs, however, increased in regenerating liver after two-thirds partial hepatectomy compared with sham-operated rats. The enzymatic activities of GnT-III and -V increased in proportion to mRNA expression. To determine which type of cells in the liver have high activities of these glycosyltransferases, hepatocytes and nonparenchymal cells were separated by means of a two-step collagenase perfusion technique. GnT-III activity was only detected in nonparenchymal cells of normal rat liver. However, during liver regeneration, GnT-III activity increased and thus was also detectable in hepatocytes. GnT-V activity was detected in both types of cells. These data were supported by reverse transcription-polymerase chain reaction results. Although the mechanism underlying the induction of these glycosyltransferases is unknown, lectin blot analysis showed that oligosaccharides in many glycoproteins, including hepatocyte growth factor, a major growth factor associated with liver regeneration, were newly synthesized during liver regeneration. This is the first report on the expression of glycosyltransferases during liver regeneration and suggests that there are different mechanisms involved in regulation of the genes of GnT-III and -V during liver regeneration.
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PMID:Gene expression of N-acetylglucosaminyltransferases III and V: a possible implication for liver regeneration. 748 97

To examine potential mechanisms by which hematopoiesis may be regulated by endothelial cells within the bone marrow (BM) microenvironment, we have devised a technique for the in vitro study of the interaction of human BM microvascular endothelial cells (BMEC) with hematopoietic cells. Microvessels isolated by collagenase digestion of spicules obtained from filtered BM aspirate were plated on gelatin-coated plastic dishes, and colonies of endothelial cells grown from microvessel explants were further purified by Ulex europaeus lectin affinity separation. BMEC monolayers isolated by this technique grew in typical cobblestone fashion, stained positively with antibody to factor VIII/von Willebrand factor, and incorporated acetylated LDL. Immunohistochemical studies showed that BM microvessels and BMEC monolayers express CD34, PECAM, and thrombospondin. Incubation of resting BMEC with BM mononuclear hematopoietic cells resulted in the selective adhesion of relatively large numbers of CD34+ progenitor cells and megakaryocytes. The binding of purified BM-derived CD34+ progenitor cells to BMEC was dependent on divalent cations and was partially blocked by antibodies to CD34. IL-1 beta treatment of BMEC monolayers resulted in an increase of CD34+ progenitor cell adhesion by mechanisms independent of CD34 or divalent cations. BMEC exhibit specific affinity for CD34+ progenitor cells and megakaryocytes, suggesting that the BM microvasculature may play a role in regulating the trafficking, proliferation, and differentiation of lineage specific hematopoietic elements, and possibly of pluripotent stem cells within the CD34+ population.
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PMID:Isolation and characterization of human bone marrow microvascular endothelial cells: hematopoietic progenitor cell adhesion. 751 3

Microvascular endothelial cells play an important part in inflammation as well as in organ specific leucocyte traffic, and may be functionally different from large vessel endothelium in this respect. This study therefore established a method for isolation and longterm culture of human intestinal microvascular endothelial cells (HIMEC). After dissociation by collagenase/dispase/DNase of mucosal and submucosal tissue obtained from normal adult jejunum, cells were plated and cultured to subconfluence in endothelial serum free medium containing 2.5% fetal calf serum, hydrocortisone, and N6, O2-dibutyryladenosine cyclic monophosphate. Primary cultures were trypsinised and endothelial cells were isolated by paramagnetic beads armed with monoclonal antibody to CD31. Optimal growth conditions for HIMEC cultures were established, allowing up to nine passages (three months in vitro). The cells contained Weibel-Palade bodies, expressed von Willebrand factor, CD31, and VE-cadherin; and bound Ulex Europaeus lectin I. A method to establish longterm cell cultures of HIMEC will facilitate further investigation of the function of intestinal endothelial cells and their participation in physiological and pathological events in the gut.
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PMID:Isolation and longterm culture of human intestinal microvascular endothelial cells. 755 73

In this study, we analyzed the expression of different leukocyte surface antigens, of the adhesion molecules ELAM-1 and GMP-140 and binding of various lectins and neoglycoproteins in inflamed gingival tissue. Cell suspensions from collagenase-digested gingiva were analyzed by flow cytometry in a FACScan. The expression of ELAM-1, GMP-140, carbohydrate structures and lectins in gingival specimens was also studied by immunohistochemistry. Gingival tissue of patients with active periodontal disease contained between 5% and 50% CD45+ mononuclear cells, consisting mainly of CD19+ cells (B lymphocytes). CD62, resembling GMP-140, and ELAM-1 were strongly expressed on endothelial cells of these patients. Control subjects usually contained almost no CD45+ cells in their gingiva and no CD62+ or ELAM-1-positive endothelial cells could be found in 5 of 6 control persons. Analysis of the glycosylation pattern revealed staining of infiltrating cells by peanut agglutinin (PNA; specificity for galactose), whereas soy bean agglutinin (SBA; specificity for N-acetyl-galactosamine) bound to epithelial cells. An endogenous lactosyl-specific lectin could be detected on endothelial cells by binding of lactosyl-BSA. Ulex europeus I agglutinin (UEA-1, specific for fucose) showed selective staining of endothelial and epithelial cells. Expression of a fucose-binding lectin, demonstrated by binding of fucosylated BSA, could be found on infiltrating cells. The adhesion molecules ELAM-1 and GMP-140 seem to be involved in cell adhesion during chronic inflammation of the gingiva. Interaction of other carbohydrate residues with endogenous lectins might resemble additional adhesion mechanisms in inflamed gingiva.
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PMID:Lectin binding to chronic inflammatory gingival tissue: possible adhesion mechanisms based on lectin-carbohydrate interactions. 768 52

Our experiments were designed to determine whether recombinant ribonuclease inhibitor (RNasin) could inhibit angiogenesis and reduce tumor growth in adult mice. We used the Fajardo disc angiogenesis assay as the primary means of measuring new blood vessel growth. This assay measures the penetration of cells into a polyvinyl alcohol sponge with a central core of ELVAX-coated sponge containing test substances. Cell penetration was reduced to 29.3% of control (phosphate-buffered saline; heat-inactivated RNasin) values. Endothelial cell influx was measured by lectin staining and confirmed by culturing cells isolated from sponges by collagenase treatment. RNasin also reduced the augmented reaction evoked by either basic fibroblast growth factor (bFGF) or sodium orthovanadate. To confirm the anti-angiogenic activity of RNasin, Hydron-coated polyvinyl sponges containing bFGF or bFGF plus RNasin were implanted into adult mouse corneas. bFGF induced a strong angiogenic response that was almost completely inhibited by RNasin. RNasin-containing ELVAX-coated sponges implanted subcutaneously underneath an intradermal inoculum of C755 mammary tumor cells caused significant reduction in tumor growth (P < 0.005). The antitumor effect of RNasin correlated with its effect on tumor-induced neovascularization, suggesting that the ability of RNasin to affect tumor growth was due to its ability to inhibit angiogenesis.
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PMID:A ribonuclease inhibitor expresses anti-angiogenic properties and leads to reduced tumor growth in mice. 768 85

Chorionic villi excised from freshly delivered human term placentae and small endothelial cell aggregates were released from them by the sequential use of collagenase and trypsin. The endothelial cells were further isolated by rosetting with magnetic polystyrene beads which were coated with QB END/40, the endothelial-specific monoclonal antibody (mAb) to thrombomodulin. Cell rosettes were plated on gelatin coated Petri dishes. The cells initially grew as discrete colonies but reached confluence within 7 days. The monolayers were sub-cultured five times, and grew to confluence each time. All the cells were immunoreactive to the endothelial markers von Willebrand factor, QB-End/40 and Ulex europaeus-1 lectin. They did not show immunoreactivity to trophoblast markers (mAbs ED341 and ED235). The isolated cells could also incorporate acetylated low-density lipoprotein. Most of the cells possessed an elongated morphology, though some were slightly spread and polygonal in shape. The cell monolayers did not resemble the typical cobblestone appearance of endothelial cells isolated from large vessels. Ultrastructurally, most of the cells resembled placental microvascular cells in shape and frequency of caveolae; undifferentiated cell-cell contacts and extracellular matrix material was observed. Human placental microvascular endothelial cells may offer an in vitro model which complements the use of the perfused term placental lobule in studies of microvascular permeability.
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PMID:Isolation of endothelial cells from human term placental villi using immunomagnetic beads. 793 93

A galactose-binding protein of M(r) = 30,000 previously described in baby hamster kidney cells (Foddy, L., Stamatoglou, S. C., and Hughes, R. C. (1990) J. Cell Sci. 97, 139-148) has been analyzed by the cloning and sequencing of cDNA clones encoding the complete sequence and an amino-terminal fragment. The intact lectin CBP30 contains 245 amino acid residues, including the initiating methionine residue, and is closely homologous to mammalian S-type lectins of similar size characterized in human, rat, and mouse species. The carboxyl-terminal domain contains the carbohydrate binding activity and the amino-terminal domain, which is extremely sensitive to bacterial collagenase, contains a repetitive sequence rich in glycine, tyrosine, and proline. There are 8 repeats in hamster CBP30, as in the human homologue, compared with about 10 in rat and mouse and > 10 in dog homologues. This repeat sequence is also sensitive to the tissue metalloproteinases, gelatinase B and matrilysin, but, unlike the bacterial collagenase, the mammalian enzymes also cause extensive degradation of the carbohydrate binding carboxyl domain. Physical measurements using CD and tryptophan fluorescence spectroscopy indicate that the two domains of CBP30 are structurally, as well as functionally, distinct and independent. Cross-linking studies indicate that the amino-terminal lectin fragment can efficiently self-assemble into oligomeric species, and less efficient but significant aggregation of the intact lectin is also shown. Domain-specific antibodies to hamster CBP30 have been prepared and used to show that only the full-length, undegraded form of CBP30 is present in whole cell lysates.
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PMID:Structure of baby hamster kidney carbohydrate-binding protein CBP30, an S-type animal lectin. 802 86

A lactose-binding lectin from rat lung (RL-29) and a related lectin from Madin-Darby canine kidney (MDCK) cells have been analyzed with the primary goal of identifying post-translational modifications. The sequences show that RL-29 and the dog lectin are homologues of a lectin designated here as L-29 and elsewhere as CBP-35, epsilon BP, Mac-2, or L-34. RL-29 has a 140-amino-acid COOH-terminal carbohydrate-binding domain, a 20-amino-acid NH2-terminal domain, and an intervening domain consisting of 11 repeating elements rich in Pro, Gly, and Tyr (R-domain). The dog homologue has 14 repeating elements in its R-domain explaining its larger size. The sensitivity of the R-domain to bacterial collagenase allowed us to isolate the NH2-terminal domain and show that the NH2 terminus was blocked by acetylation and, in the accompanying paper (Huflejt, M. E., Turck, C. W., Lindstedt, R., Barondes, S. H., and Leffler, H. (1993) J. Biol. Chem. 268, 26712-26718), that the NH2-terminal domain is phosphorylated. In addition, we unexpectedly found an endogenous component, resembling 92-kDa type IV collagenase, that co-purified with L-29 and slowly digested the R-domain. Hence, L-29 is a substrate for bacterial and tissue collagenases even though the R-domain is non-collagenous. Moreover, the co-purification suggests a non-enzymatic interaction between 92-kDa collagenase and L-29.
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PMID:Primary structure of the soluble lactose binding lectin L-29 from rat and dog and interaction of its non-collagenous proline-, glycine-, tyrosine-rich sequence with bacterial and tissue collagenase. 825 5


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