0000000000218921
AUTHOR
S. Schwögler
showing 7 related works from this author
Expression of the gene of the alpha-smooth muscle-actin isoform in rat liver and in rat fat-storing (ITO) cells.
1990
Fat storing cells (FSCs) in the liver represent the main site of vitamin A deposition in the body. These cells are considered to play an important role during scar formation and fibrogenesis in the liver. The putative descent of FSCs from the fibroblastic or from the myofibroblastic system have not been determined yet by morphological or immunohistochemical studies. To further define the origin of these liver cells, we analysed the pattern of expression of three structural proteins: vimentin, desmin and the α-smooth muscle (SM)-actin isoform in FSCs of the rat liver, in smooth muscle cells (SMCs) from the aorta and in rat skin fibroblasts. FSCs were studied by immunohistochemical methods im…
Dexamethasone modulates α2-macroglobulin and apolipoprotein E gene expression in cultured rat liver fat-storing (Ito) cells
1991
Fat-storing (Ito) cells are perisinusoidal liver cells thought to play a central role in vitamin A metabolism and fibrogenesis. Glucocorticoids have been shown to be beneficial in the treatment of certain types of liver diseases by delaying the development of cirrhosis. To study the regulatory effects of dexamethasone on Ito cell gene expression, Ito cells were isolated from normal rat liver and primary cultures were established. The effect of dexamethasone on the synthesis of α2-macroglobulin, apolipoprotein E, fibronectin and actin was examined. Protein synthesis was studied both at the protein level and at the RNA level by means of biosynthetic labeling, immunoprecipitation followed by s…
Synthesis of undulin by rat liver fat-storing cells: Comparison with fibronectin and tenascin
1992
Abstract Fat-storing cells (FSCs) are known to synthesize various components of the hepatic extracellular matrix and thereby play an important role during liver fibrogenesis. The aim of our study was to investigate the synthesis of undulin, a recently described connective tissue protein belonging to the fibronectin—tenascin superfamily of glycoproteins, by fat-storing cells in primary culture. SDS-PAGE analysis of immunoprecipitates from cell layer lysates or media pulse-labeled with radioactive methionine revealed undulin-specific bands A (270 kDa), B1 (190 kDa), and B2 (180 kDa) after reduction. A single undulin-specific transcript was detected at about 7 kb. Undulin synthesized by cell-f…
Fat-storing cells of the rat liver synthesize and secrete C1-esterase inhibitor; modulation by cytokines.
1992
During liver fibrogenesis, fat-storing cells transform into myofibroblast-like cells and produce increasing amounts of extracellular matrix proteins. Because fat-storing cells produce α2-macroglobulin, an important serine protease inhibitor (serpin), we investigated whether fat-storing cells also synthesize C1-esterase inhibitor, another important serpin. C1-esterase inhibitor synthesis was studied in rat fatstoring cells at day 0, 3 and 7 after isolation by biosynthetic labeling, immunoprecipitation and sodium dodecyl sulfate–polyacrylamide gel electrophoresis. Messenger RNA was examined by Northern-blot analysis. C1-esterase inhibitor gene expression and synthesis were detectable in fresh…
The gene of hepatocyte growth factor is expressed in fat-storing cells of rat liver and is downregulated during cell growth and by transforming growt…
1992
Hepatocyte growth factor (HGF) has been detected in non-parenchymal cells but not in hepatocytes. We performed Northern blot analysis of total RNA extracted from rat hepatocytes, Kupffer cells, endothelial cells and fat-storing (Ito-) cells. Total RNA was extracted from fat-storing cells at different times after isolation and from cells treated with different amounts of transforming growth factor beta. The RNA was hybridized with HGF, fibronectin-, and alpha-actin-specific cDNA probes, consecutively. We found an abundant amount of HGF mRNA in freshly isolated fat-storing cells, but not in other liver cells. The amount of the HGF transcripts decreases significantly in FSC during the time of …
Tenascin gene expression in rat liver and in rat liver cells. In vivo and in vitro studies.
1991
Tenascin is a major glycoprotein constituent of the extracellular matrix with a strong affinity to fibronectin; its distribution is believed to be temporarily and spatially limited. Tenascin gene expression is increased during wound healing processes. As repair mechanisms in chronic liver diseases resemble wound healing we studied tenascin gene expression in rat liver and in isolated rat liver cells. In normal rat liver a tenascin specific antiserum stains sinusoidal cells with fiber-like prolongations, which at the same time are desmin-positive (ITO-cells). In the CCl4-acutely-damaged liver a strong tenascin staining is detected in cells located among the mononuclear cells of the inflammat…
Alternative splicing products of the tenascin gene distinguish rat liver fat storing cells from arterial smooth muscle cells and skin fibroblasts
1992
Abstract Fat storing-(Ito-)cells (FSC) transform into a myofibroblast-like cell type during liver fibrogenesis. A similar development can be observed in cell culture. At the moment, a definite marker to differentiate transformed FSC from smooth muscle cells (SMC) is not available. We recently found that FSC, SMC and skin fibroblasts (SF) synthesize tenascin, a novel matrix protein. As it is reported that various tissues express different tenascin forms by the mechanism of alternative pre-mRNA splicing, we analyzed the tenascin transcripts in these cell types. Total RNA extracted from cultured FSC, SMC and SF, analyzed by Northern blot hybridization, showed a 7.2 kb transcript in FSC, a 8.7 …