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)

Endothelial cells and macrophages are located within the hepatic sinusoids. These two cell types play an important role in the clearance of bacterially derived lipopolysaccharide from the portal circulation. Our laboratory has previously demonstrated that treatment of rats with lipopolysaccharide results in the accumulation of macrophages in the liver that display properties of activated mononuclear phagocytes. This study was designed to analyze the effects of lipopolysaccharide on hepatic endothelial cells. Female Sprague-Dawley rats were treated with 5 mg/kg of lipopolysaccharide. Macrophages and endothelial cells were isolated from the rats 48 hr later by in situ perfusion of the liver with collagenase and pronase followed by differential centrifugation and centrifugal elutriation. We found that lipopolysaccharide treatment of rats resulted in an increase in the number of both macrophages and endothelial cells recovered from the liver. Using specific monoclonal antibodies and flow cytometry, both macrophages and endothelial cells were found to express cell surface markers for Ia antigen, leukocyte common antigen, CD4 and the macrophage antigen, ED2. Macrophages expressed greater levels of these markers than endothelial cells. Flow cytometric analysis also revealed considerable subpopulation heterogeneity in the endothelial cells in antigen expression, physical characteristics and functional activity. Treatment of rats with lipopolysaccharide decreased expression of cell surface markers on the macrophages but not on the endothelial cells. This may be due to the distinct origin of these cells. To determine whether endothelial cells, like macrophages, were activated by lipopolysaccharide, we examined their ability to produce reactive oxygen intermediates.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Lipopolysaccharide treatment of rats alters antigen expression and oxidative metabolism in hepatic macrophages and endothelial cells. 131 50

Cell surface markers of mouse thymic dendritic cells have been studied by flow cytometry after isolation by collagenase digestion, separation of the low-density cell fraction and differential adherence. The dendritic cell preparation had a purity of greater than 90%, the contaminating population being essentially composed of thymocytes, macrophages constituting less than 1%. Dendritic cells displayed high forward and low-intermediate side angle scatter, and expressed high levels of major histocompatibility complex (MHC) class I and class II molecules, the heat-stable antigen (HSA), the adhesion molecules Pgp-1 (CD44), LFA-1, ICAM-1 and low levels of Mac-1 and the leukocyte common antigen CD45. Thymic dendritic cells are negative for the stem cell antigen-2 (Sca-2), the B cell-specific form of CD45 (B220), the mouse macrophage markers Fc receptor and F4/80, and the granulocyte marker Gr-1. However, although they do not express the T cell markers Thy-1, CD2, CD3, CD4 and CD5, 20%-30% of dendritic cells are positive for the interleukin 2 receptor alpha chain (CD25), and about 30% express intermediate levels of CD8. These results are discussed with regard to the functional significance of the expression of CD8 by thymic dendritic cells, and the existence of different dendritic cell subpopulations in the murine thymus.
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PMID:Cell surface marker analysis of mouse thymic dendritic cells. 134 47

The authors have developed a procedure for the isolation of alveolar Type I (ATI) cells from adult rat lung. After an initial selective enzymatic digestion of the lungs by lavage with 0.2% collagenase, 0.05% trypsin, 0.008% elastase, and 0.005% DNAse Type I, the cells which are released are separated by density gradient centrifugation, and a fraction which includes all ATI cells (density, 1.0177-1.0411) is harvested. Contaminating leukocytes are excluded by specific surface adsorption, exploiting the fact that these cells have leukocyte common antigen on their surfaces, whereas ATI cells do not. Similarly, contaminating alveolar Type II (ATII) cells are removed by specific surface adsorption with the use of the lectin Maclura pomifera agglutinin, which binds to freshly isolated ATII cells and not to ATI cells. Our procedure yields 5 X 10(6) ATI cells per rat in a fraction that is at least 85-88% pure; the cells are immediately available for biochemical or pharmacologic analysis and represent a 98% recovery of the ATI cells loaded onto the density gradient. The ATI cells retain their essential in vivo morphologic characteristics, including their polarity.
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PMID:Isolation of pulmonary alveolar type I cells from adult rats. 294 39

A transplantable macrophage-like cell line has been obtained and established in W rats. This cell line is in its 85th passage and is perhaps the only established macrophage-like cell line that grows rapidly intraperitoneally in rats. The cells possess some of the typical characteristics of macrophages, such as adherence to glass, phagocytosis, presence of Fc receptors and C3d receptors, la determinants, leukocyte common antigen, lysozyme, non-specific esterase, and glycogen. The tumor also grows as solid when injected sc, intradermally, or intramuscularly. The cells have collagenase, tyrosine-specific protein kinase, and several other hydrolases. Histopathologic and ultrastructural observations suggest it to be a histiocytic tumor. The availability of a macrophage cell line of rat origin provides a useful experimental model to study different macrophage functions at the cellular and molecular level.
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PMID:Development and characterization of a rat histiocyte-macrophage tumor line. 345 75

Antigen-retaining follicular dendritic cells (FDC) have been identified and studied in sections of lymph nodes and spleen, but studies of these cells in culture have been extremely limited. The purpose of this study was to establish techniques to release these fragile cells from mouse lymph nodes in a viable state and to identify these cells routinely in lymph node cell suspensions. FDC were obtained from passively or actively immunized popliteal lymph nodes of mice injected in the footpads with 125I-labeled human serum albumin (HSA) or horseradish peroxidase (HRP). Lymph nodes were removed 1 hr after the footpads had been injected with collagenase. After another hour of incubation in vitro with collagenase, protease, and deoxyribonuclease, FDC were released by gentle teasing and enriched by centrifugation on a low density bovine serum albumin (BSA) or Percoll gradient. Most FDC with the associated radiolabel floated at densities greater than 1.06 g/ml on BSA or Percoll gradients. Slides of the FDC-enriched fraction were prepared, using a cytobucket which allowed the cells to be affixed to glass slides by centrifugation in a less disruptive manner than by cytocentrifugation. FDC that were air-dried and fixed with 3% glutaraldehyde had a characteristic pink acidophilic cytoplasm after Wright's staining, and had a faintly basophilic euchromatic nucleus frequently with peripherally-clumped chromatin. In addition, these cells were large and irregularly shaped (up to 60 micron long). Fixation of FDC with 0.6% paraformaldehyde/ 0.9% glutaraldehyde on poly-L-lysine-coated slides resulted in a preservation of FDC which made possible visualization of long dendritic processes by Nomarski optics. Antigen presence on the cell surface was confirmed by autoradiography and, in the case of HRP, was also visualized enzymatically using diaminobenzidine. In contrast to resident peritoneal macrophages or some contaminating lymph node macrophages present on the same slides, FDC did not phagocytize opsonized sheep red blood cells (SRBC) or adhere to plastic surfaces although they did form rosettes with opsonized SRBC. Cell marker studies indicated FDC have a distinctive phenotype. They were positive for Ia, Fc receptor, and leukocyte common antigen, but negative for Thy-1, Ly-1, Ly-2, endogenous Ig, Mac-1, Mac-2, Mac-3, and F4/80, and negative to weakly positive for nonspecific esterase. Cultured FDC remained viable and retained radiolabeled antigen-antibody complexes on their surfaces and were significantly enriched for FDC.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Follicular dendritic cells in suspension: identification, enrichment, and initial characterization indicating immune complex trapping and lack of adherence and phagocytic activity. 396 23

Mononuclear cells isolated from sinusoid of rat liver by collagenase perfusion method showed a strong inhibitory effect on epidermal growth factor-stimulated proliferation of cocultured autologous hepatocytes, while mononuclear cells from peripheral blood and spleen did not. This inhibitory effect depended on the effector/target ratio. In a single-color flow cytometric analysis, about 25% of sinusoidal mononuclear cells consisted of asialo GM1+ natural killer cells, and there were relatively small numbers of CD3+ T cells and a few leukocyte common antigen-positive B cells compared to peripheral blood mononuclear cells. The natural killer cell activity of sinusoidal mononuclear cells was much stronger than that of peripheral blood mononuclear cells and splenic mononuclear cells. This activity was completely suppressed by the treatment with anti-asialo GM1 antibody plus complement. However, their inhibitory activity on proliferation of autologous hepatocytes was not affected by this treatment. These results suggest that the sinusoidal mononuclear cells, probably CD3+ T cells, play a role in regulation of autologous hepatocyte proliferation.
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PMID:Inhibition of epidermal growth factor-stimulated hepatocytes proliferation by autologous sinusoidal mononuclear cells in rat liver. 840 41