The Experts below are selected from a list of 183 Experts worldwide ranked by ideXlab platform
Detlef Schuppan - One of the best experts on this subject based on the ideXlab platform.
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fibrogenesis and fibrolysis in collagenous colitis patterns of procollagen types i and iv matrix metalloproteinase 1 and 13 and timp 1 gene expression
American Journal of Pathology, 1999Co-Authors: Ute Gunther, Detlef Schuppan, Michael Bauer, H Matthes, A Stallmach, Annette Schmittgraff, E O Riecken, H HerbstAbstract:Collagenous colitis is characterized by the deposition of a superficial subepithelial collagenous layer, the pathogenesis of which is unknown. Because the excess matrix deposition is potentially reversible, a labile imbalance between fibrogenesis and fibrolysis may be suspected. Expression of procollagen α1(I) and α1(IV), matrix-metalloproteinase (MMP)-1 and -13, and tissue inhibitor of metalloproteinase (TIMP)-1 genes was semiquantitated by in situ hybridization on serial biopsies of 12 patients with collagenous colitis and compared to controls. Collagen types I, III, IV, and VI, tenascin, Undulin/collagen XIV, and α-actin were localized by immunohistology. The superficial collagen layer stained strongly for collagen types I, III, and VI, and particularly for tenascin, but not for Undulin. Elevated procollagen α1(I), procollagen α1(IV), and TIMP-1 transcript levels were found in α-actin-positive cells with linear distribution underneath the superficial collagenous layer, whereas MMP-1 RNA expression was variable and restricted to cell clusters. MMP-13 expression was undetectable. The patterns of procollagen α1(I)- and α1(IV)-specific labeling, combined with an intense tenascin- but absent Undulin-specific staining, indicate deposition of an immature interstitial matrix that may be susceptible to degradation. The restricted MMP-1 RNA expression, counteracted by increased TIMP-1 expression, suggests locally impaired fibrolysis as a relevant factor in the pathogenesis of collagenous colitis.
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localization of a cell adhesion site on collagen xiv Undulin
Experimental Cell Research, 1998Co-Authors: Tobias Ehnis, Walburga Dieterich, Michael Bauer, Detlef SchuppanAbstract:Abstract Cell adhesion to collagen XIV is implied to be mediated by proteoglycans as cellular receptors (T. Ehniset al.,1996,Exp. Cell Res.229, 388–397). In order to define the cell binding region(s), fusion proteins expressed inEscherichia coliand covering the large noncollagenous domain NC3 of collagen XIV were used as substrates for the adhesion of skin fibroblasts. A prominent cell binding site could be localized in the N-terminal fibronectin type III repeat of collagen XIV and its immediate C-terminal extension. Since this region also mediates the binding of the small chondroitin/dermatan sulfate proteoglycan decorin (T. Ehniset al.,1997,J. Biol. Chem.272, 20414–20419), our finding could provide the molecular basis for the observation that decorin serves as inhibitor and potential modulator of cellular interactions with collagen XIV.
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differential expression of type xiv collagen Undulin by human mammary gland intralobular and interlobular fibroblasts
Cell and Tissue Research, 1998Co-Authors: Amanda J Atherton, Detlef Schuppan, Michael J Warburton, Michael J Ohare, Paul Monaghan, Barry A GustersonAbstract:Immunolocalisation of type XIV collagen/Undulin in the human mammary gland revealed greater deposition in the interlobular stroma than in the intralobular stroma. The interlobular stroma is located between the breast lobules and their associated intralobular stroma. Fibroblasts isolated from the interlobular stroma synthesised 3- to 5-fold more type XIV collagen/Undulin than intralobular fibroblasts, but synthesised type I and type IV collagens in similar amounts. The differential expression of type XIV collagen/Undulin was maintained with passage in culture. The results suggest a role for type XIV collagen/Undulin in stabilising dense collagen fibrils. The maintenance of two types of structurally distinct stromas may be important during developmental processes in the mammary gland.
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complete primary structure of human collagen type xiv Undulin
Biochimica et Biophysica Acta, 1997Co-Authors: Michael Bauer, Walburga Dieterich, Tobias Ehnis, Detlef SchuppanAbstract:Abstract A partial cDNA sequence coding for the human extracellular matrix protein Undulin has been completed. The completed sequence provides conclusive evidence for the suggested identity of Undulin and collagen type XIV. Two differently sized polyproteins of 1780 and 1796 amino acids, with an overall amino acid sequence identity of 75% compared to chicken CXIV, emerge from variant 3′ sequence ends encoding the C-terminal non-collagenous (NC) NC1 domain of human collagen type XIV.
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localization of a binding site for the proteoglycan decorin on collagen xiv Undulin
Journal of Biological Chemistry, 1997Co-Authors: Tobias Ehnis, Walburga Dieterich, Michael Bauer, Hans Kresse, Detlef SchuppanAbstract:Abstract Through its ability to bind extracellular matrix constituents and growth factors the small leucine-rich chondroitin/dermatan sulfate proteoglycan decorin which is present in many types of connective tissues may play an important biological role in remodeling and maintenance of extracellular matrices during inflammation, fibrosis, and cancer growth. In this study we investigated the known binding of decorin to human collagen XIV. This binding was unaffected when the small collagenous moiety of collagen XIV was removed with collagenase. Therefore, fragments covering the large noncollagenous domain NC3 of collagen XIV were expressed inEscherichia coli, each fused to a 26-kDa fragment of glutathione S-transferase. Using radioiodinated decorin as ligand for the immobilized fusion proteins, a binding site that interacted with the decorin core protein could be assigned to the NH2-terminal fibronectin type III repeat of collagen XIV. In addition, an auxiliary binding site located COOH-terminal to this fibronectin type III repeat interacted with the glycosaminoglycan component of decorin.
Michael Bauer - One of the best experts on this subject based on the ideXlab platform.
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fibrogenesis and fibrolysis in collagenous colitis patterns of procollagen types i and iv matrix metalloproteinase 1 and 13 and timp 1 gene expression
American Journal of Pathology, 1999Co-Authors: Ute Gunther, Detlef Schuppan, Michael Bauer, H Matthes, A Stallmach, Annette Schmittgraff, E O Riecken, H HerbstAbstract:Collagenous colitis is characterized by the deposition of a superficial subepithelial collagenous layer, the pathogenesis of which is unknown. Because the excess matrix deposition is potentially reversible, a labile imbalance between fibrogenesis and fibrolysis may be suspected. Expression of procollagen α1(I) and α1(IV), matrix-metalloproteinase (MMP)-1 and -13, and tissue inhibitor of metalloproteinase (TIMP)-1 genes was semiquantitated by in situ hybridization on serial biopsies of 12 patients with collagenous colitis and compared to controls. Collagen types I, III, IV, and VI, tenascin, Undulin/collagen XIV, and α-actin were localized by immunohistology. The superficial collagen layer stained strongly for collagen types I, III, and VI, and particularly for tenascin, but not for Undulin. Elevated procollagen α1(I), procollagen α1(IV), and TIMP-1 transcript levels were found in α-actin-positive cells with linear distribution underneath the superficial collagenous layer, whereas MMP-1 RNA expression was variable and restricted to cell clusters. MMP-13 expression was undetectable. The patterns of procollagen α1(I)- and α1(IV)-specific labeling, combined with an intense tenascin- but absent Undulin-specific staining, indicate deposition of an immature interstitial matrix that may be susceptible to degradation. The restricted MMP-1 RNA expression, counteracted by increased TIMP-1 expression, suggests locally impaired fibrolysis as a relevant factor in the pathogenesis of collagenous colitis.
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localization of a cell adhesion site on collagen xiv Undulin
Experimental Cell Research, 1998Co-Authors: Tobias Ehnis, Walburga Dieterich, Michael Bauer, Detlef SchuppanAbstract:Abstract Cell adhesion to collagen XIV is implied to be mediated by proteoglycans as cellular receptors (T. Ehniset al.,1996,Exp. Cell Res.229, 388–397). In order to define the cell binding region(s), fusion proteins expressed inEscherichia coliand covering the large noncollagenous domain NC3 of collagen XIV were used as substrates for the adhesion of skin fibroblasts. A prominent cell binding site could be localized in the N-terminal fibronectin type III repeat of collagen XIV and its immediate C-terminal extension. Since this region also mediates the binding of the small chondroitin/dermatan sulfate proteoglycan decorin (T. Ehniset al.,1997,J. Biol. Chem.272, 20414–20419), our finding could provide the molecular basis for the observation that decorin serves as inhibitor and potential modulator of cellular interactions with collagen XIV.
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complete primary structure of human collagen type xiv Undulin
Biochimica et Biophysica Acta, 1997Co-Authors: Michael Bauer, Walburga Dieterich, Tobias Ehnis, Detlef SchuppanAbstract:Abstract A partial cDNA sequence coding for the human extracellular matrix protein Undulin has been completed. The completed sequence provides conclusive evidence for the suggested identity of Undulin and collagen type XIV. Two differently sized polyproteins of 1780 and 1796 amino acids, with an overall amino acid sequence identity of 75% compared to chicken CXIV, emerge from variant 3′ sequence ends encoding the C-terminal non-collagenous (NC) NC1 domain of human collagen type XIV.
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localization of a binding site for the proteoglycan decorin on collagen xiv Undulin
Journal of Biological Chemistry, 1997Co-Authors: Tobias Ehnis, Walburga Dieterich, Michael Bauer, Hans Kresse, Detlef SchuppanAbstract:Abstract Through its ability to bind extracellular matrix constituents and growth factors the small leucine-rich chondroitin/dermatan sulfate proteoglycan decorin which is present in many types of connective tissues may play an important biological role in remodeling and maintenance of extracellular matrices during inflammation, fibrosis, and cancer growth. In this study we investigated the known binding of decorin to human collagen XIV. This binding was unaffected when the small collagenous moiety of collagen XIV was removed with collagenase. Therefore, fragments covering the large noncollagenous domain NC3 of collagen XIV were expressed inEscherichia coli, each fused to a 26-kDa fragment of glutathione S-transferase. Using radioiodinated decorin as ligand for the immobilized fusion proteins, a binding site that interacted with the decorin core protein could be assigned to the NH2-terminal fibronectin type III repeat of collagen XIV. In addition, an auxiliary binding site located COOH-terminal to this fibronectin type III repeat interacted with the glycosaminoglycan component of decorin.
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a chondroitin dermatan sulfate form of cd44 is a receptor for collagen xiv Undulin
Experimental Cell Research, 1996Co-Authors: Tobias Ehnis, Walburga Dieterich, Michael Bauer, Bernd Von Lampe, Detlef SchuppanAbstract:Collagen XIV, a fibril-associated collagen with interrupted triple helices, is expressed in differentiated soft connective tissues and in cartilage. However, a cellular receptor for this protein has not been identified. Here we show that human placental collagen XIV, isolated by a mild and simple two-step method, serves as adhesive protein for a variety of mesenchymal and some epithelial cells. Cell adhesion could be inhibited by preincubation of the collagen XIV substrate with heparin or with the chondroitin/dermatan sulfate proteoglycan decorin and by pretreatment of cells with chondroitinase ABC or heparinase III, suggesting a cell membrane proteoglycan as receptor. Affinity chromatography of125I-labeled fibroblast cell surface proteins on collagen XIV–Sepharose yielded a chondroitin/dermatan sulfate proteoglycan with a molecular mass of 97–105 kDa after chondroitinase ABC digestion and of 60–70 kDa after further treatment withN-glycosidase F. The eluates contained also some high-molecular-weight material that was susceptible to digestion with heparinase but no detectable integrins. Immunoprecipitation with a specific monoclonal antibody identified the prominent chondroitin/dermatan sulfate proteoglycan as a member of the CD44 family. The interaction between collagen XIV and cells appears to be finely tuned, since matrix-associated glycosaminoglycans, and particularly proteoglycans like decorin, could compete with cells for the binding site(s) on collagen XIV under physiological conditions.
Giuliano Ramadori - One of the best experts on this subject based on the ideXlab platform.
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synthesis of Undulin by rat liver fat storing cells comparison with fibronectin and tenascin
Experimental Cell Research, 1992Co-Authors: T Knittel, Detlef Schuppan, Margarete Odenthal, S Schwogler, Martin Just, Karlherrmann Meyer Zum Buschenfelde, Giuliano RamadoriAbstract: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-free translation revealed two polypeptides migrating about 5000 Da below the B1 and B2 subunits. Treatment of FSCs with tunicamycin created two novel bands slightly below the B2 chain. Since the electrophoretic patterns of Undulin chains recovered by cell-free translation and tunicamycin treatment of cells were very similar we suggest that N-glycosylation is the major post-translational processing event. Newly synthesized Undulin was detected after 30 min of pulse labeling in the cell layer fraction and was secreted into the medium at a slower rate than fibronectin. In contrast to fibronectin and tenascin, Undulin was already synthesized by freshly isolated FSCs and during the early stage of primary FSC culture (“resting” cells), supporting the hypothesis that Undulin is associated with a differentiated mesenchyma. However, in analogy to fibronectin and tenascin, Undulin was also synthesized by “activated” FSCs, indicating that Undulin might also be of importance in dedifferentiated tissues.
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distribution and cellular origin of Undulin in rat liver
Laboratory Investigation, 1992Co-Authors: T Knittel, Detlef Schuppan, S Schwogler, T Armbrust, Giuliano RamadoriAbstract:BACKGROUND Undulin is a novel large glycoprotein of the interstitial extracellular matrix belonging to the fibronectin-tenascin glycoprotein gene family. The distribution in diseased liver and the cellular origin of this protein are unknown. EXPERIMENTAL DESIGN Immunohistochemistry studies were performed on cryostat sections of normal and damaged rat livers (CCl4 model). Hepatocytes, Kupffer cells, fat-storing cells (FSC), and sinusoidal endothelial cells (EC) were isolated by standard methods and kept in culture. Undulin biosynthesis in vitro was studied by indirect immunofluorescence and by immunoprecipitation of endogenously labeled protein followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and autoradiography. RESULTS Undulin was demonstrated in portal stroma, in vascular adventitia, and inside the space of Disse of normal liver. Acutely and chronically damaged livers revealed strong staining reactions in damaged areas, scars, and sinusoids. The overall distribution of Undulin resembled the pattern noted for fibronectin. In contrast to Undulin, tenascin was not detectable within the adventitia of vascular and ductular structures of normal and damaged livers, and tenascin accumulated preferentially at scar-parenchyma interfaces in fibrotic livers. In vivo, desmin and smooth muscle alpha-actin positive cells were in part codistributed with Undulin fibers as shown by double staining techniques. In vitro, Undulin was detected in granules of freshly isolated FSCs and ECs and was localized as fibers in the extracellular matrix of cultivated FSCs and ECs. Synthesis of Undulin was demonstrated by immunoprecipitation of the protein from cultured FSCs and ECs. No experimental evidence was found for Undulin synthesis in vitro by hepatocytes and Kupffer cells. CONCLUSIONS The novel glycoprotein Undulin is present in the normal rat liver and accumulates during acute and chronic liver injury. Our results suggest that among the resident cells of the liver, FSCs and ECs are the major sources of Undulin.
T Knittel - One of the best experts on this subject based on the ideXlab platform.
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coexpression of extracellular matrix glycoproteins Undulin and tenascin in human autosomal dominant polycystic kidney disease
Nephron, 1993Co-Authors: Reinhard Klingel, Detlef Schuppan, T Knittel, G Ramadori, K Meyer Zum H Buschenfelde, Hans KohlerAbstract:Autosomal dominant polycystic kidney disease (ADPKD) is the most common entity of cystic diseases of the kidney leading to end-stage renal insufficiency. Changes in extracellular matrix (ECM) are regarded to be an important pathogenic factor connected with the genes assumed to be responsible for human ADPKD. In order to assess the biological significance of altered expression and deposition of ECM glycoproteins for human ADPKD at molecular levels fresh-frozen tissue from ADPKD kidneys, fetal kidneys and normal adult kidneys were comparatively tested by immunohistochemistry for the presence of multifunctional ECM glycoproteins Undulin, tenascin and fibronectin, interstitial collagen types I, III and VI and intrinsic basement membrane components laminin and collagen type IV using monoclonal antibodies and polyclonal antisera. Studies were especially focused on ECM glycoproteins Undulin and tenascin which in connection with interstitial collagens and fibronectin have specific structural and functional roles in tissue development and differentiation. Cultures of cyst-lining epithelial cells from two polycystic kidneys and autologous fibroblasts were investigated in vitro. By Northern blot analysis mRNA levels of Undulin, tenascin and the ECM-regulating growth factor transforming growth factory (TGF-β1) were investigated. A strong increase of fibrogenesis was demonstrated in tissue architecture of polycystic kidneys. Immunohistochemically subepithelial fibrous tissue of cyst walls in ADPKD kidneys showed strong coexpression of both Undulin and tenascin with marked intensity adjacent to cyst-lining epithelium. In contrast the normal adult human kidney and developmental stages of the fetal kidney showed expression patterns of Undulin and tenascin which were significantly different. Expression of interstitial coUagens I, III and VI and fibronectin reflected the overall increase of fibrogenesis indicating that in particular interactions with collagens to trigger organization of tissue architecture are abnormal. In vitro cyst-lining epithelial cells showed abundant TGF-β1 mRNA by Northern blot analysis. Tenascin transcripts were detected both in fibroblasts and in cocultures of cyst-lining epithelia and autologous fibroblasts in vitro. Undulin transcripts were not detectable under identical culture conditions, which did not yet represent the appropriate experimental model system to imitate the particular epithelial-mesenchymal interactions leading to the expression of both ECM components in ADPKD kidneys in vivo.
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synthesis of Undulin by rat liver fat storing cells comparison with fibronectin and tenascin
Experimental Cell Research, 1992Co-Authors: T Knittel, Detlef Schuppan, Margarete Odenthal, S Schwogler, Martin Just, Karlherrmann Meyer Zum Buschenfelde, Giuliano RamadoriAbstract: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-free translation revealed two polypeptides migrating about 5000 Da below the B1 and B2 subunits. Treatment of FSCs with tunicamycin created two novel bands slightly below the B2 chain. Since the electrophoretic patterns of Undulin chains recovered by cell-free translation and tunicamycin treatment of cells were very similar we suggest that N-glycosylation is the major post-translational processing event. Newly synthesized Undulin was detected after 30 min of pulse labeling in the cell layer fraction and was secreted into the medium at a slower rate than fibronectin. In contrast to fibronectin and tenascin, Undulin was already synthesized by freshly isolated FSCs and during the early stage of primary FSC culture (“resting” cells), supporting the hypothesis that Undulin is associated with a differentiated mesenchyma. However, in analogy to fibronectin and tenascin, Undulin was also synthesized by “activated” FSCs, indicating that Undulin might also be of importance in dedifferentiated tissues.
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distribution and cellular origin of Undulin in rat liver
Laboratory Investigation, 1992Co-Authors: T Knittel, Detlef Schuppan, S Schwogler, T Armbrust, Giuliano RamadoriAbstract:BACKGROUND Undulin is a novel large glycoprotein of the interstitial extracellular matrix belonging to the fibronectin-tenascin glycoprotein gene family. The distribution in diseased liver and the cellular origin of this protein are unknown. EXPERIMENTAL DESIGN Immunohistochemistry studies were performed on cryostat sections of normal and damaged rat livers (CCl4 model). Hepatocytes, Kupffer cells, fat-storing cells (FSC), and sinusoidal endothelial cells (EC) were isolated by standard methods and kept in culture. Undulin biosynthesis in vitro was studied by indirect immunofluorescence and by immunoprecipitation of endogenously labeled protein followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and autoradiography. RESULTS Undulin was demonstrated in portal stroma, in vascular adventitia, and inside the space of Disse of normal liver. Acutely and chronically damaged livers revealed strong staining reactions in damaged areas, scars, and sinusoids. The overall distribution of Undulin resembled the pattern noted for fibronectin. In contrast to Undulin, tenascin was not detectable within the adventitia of vascular and ductular structures of normal and damaged livers, and tenascin accumulated preferentially at scar-parenchyma interfaces in fibrotic livers. In vivo, desmin and smooth muscle alpha-actin positive cells were in part codistributed with Undulin fibers as shown by double staining techniques. In vitro, Undulin was detected in granules of freshly isolated FSCs and ECs and was localized as fibers in the extracellular matrix of cultivated FSCs and ECs. Synthesis of Undulin was demonstrated by immunoprecipitation of the protein from cultured FSCs and ECs. No experimental evidence was found for Undulin synthesis in vitro by hepatocytes and Kupffer cells. CONCLUSIONS The novel glycoprotein Undulin is present in the normal rat liver and accumulates during acute and chronic liver injury. Our results suggest that among the resident cells of the liver, FSCs and ECs are the major sources of Undulin.
Tobias Ehnis - One of the best experts on this subject based on the ideXlab platform.
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localization of a cell adhesion site on collagen xiv Undulin
Experimental Cell Research, 1998Co-Authors: Tobias Ehnis, Walburga Dieterich, Michael Bauer, Detlef SchuppanAbstract:Abstract Cell adhesion to collagen XIV is implied to be mediated by proteoglycans as cellular receptors (T. Ehniset al.,1996,Exp. Cell Res.229, 388–397). In order to define the cell binding region(s), fusion proteins expressed inEscherichia coliand covering the large noncollagenous domain NC3 of collagen XIV were used as substrates for the adhesion of skin fibroblasts. A prominent cell binding site could be localized in the N-terminal fibronectin type III repeat of collagen XIV and its immediate C-terminal extension. Since this region also mediates the binding of the small chondroitin/dermatan sulfate proteoglycan decorin (T. Ehniset al.,1997,J. Biol. Chem.272, 20414–20419), our finding could provide the molecular basis for the observation that decorin serves as inhibitor and potential modulator of cellular interactions with collagen XIV.
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complete primary structure of human collagen type xiv Undulin
Biochimica et Biophysica Acta, 1997Co-Authors: Michael Bauer, Walburga Dieterich, Tobias Ehnis, Detlef SchuppanAbstract:Abstract A partial cDNA sequence coding for the human extracellular matrix protein Undulin has been completed. The completed sequence provides conclusive evidence for the suggested identity of Undulin and collagen type XIV. Two differently sized polyproteins of 1780 and 1796 amino acids, with an overall amino acid sequence identity of 75% compared to chicken CXIV, emerge from variant 3′ sequence ends encoding the C-terminal non-collagenous (NC) NC1 domain of human collagen type XIV.
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localization of a binding site for the proteoglycan decorin on collagen xiv Undulin
Journal of Biological Chemistry, 1997Co-Authors: Tobias Ehnis, Walburga Dieterich, Michael Bauer, Hans Kresse, Detlef SchuppanAbstract:Abstract Through its ability to bind extracellular matrix constituents and growth factors the small leucine-rich chondroitin/dermatan sulfate proteoglycan decorin which is present in many types of connective tissues may play an important biological role in remodeling and maintenance of extracellular matrices during inflammation, fibrosis, and cancer growth. In this study we investigated the known binding of decorin to human collagen XIV. This binding was unaffected when the small collagenous moiety of collagen XIV was removed with collagenase. Therefore, fragments covering the large noncollagenous domain NC3 of collagen XIV were expressed inEscherichia coli, each fused to a 26-kDa fragment of glutathione S-transferase. Using radioiodinated decorin as ligand for the immobilized fusion proteins, a binding site that interacted with the decorin core protein could be assigned to the NH2-terminal fibronectin type III repeat of collagen XIV. In addition, an auxiliary binding site located COOH-terminal to this fibronectin type III repeat interacted with the glycosaminoglycan component of decorin.
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a chondroitin dermatan sulfate form of cd44 is a receptor for collagen xiv Undulin
Experimental Cell Research, 1996Co-Authors: Tobias Ehnis, Walburga Dieterich, Michael Bauer, Bernd Von Lampe, Detlef SchuppanAbstract:Collagen XIV, a fibril-associated collagen with interrupted triple helices, is expressed in differentiated soft connective tissues and in cartilage. However, a cellular receptor for this protein has not been identified. Here we show that human placental collagen XIV, isolated by a mild and simple two-step method, serves as adhesive protein for a variety of mesenchymal and some epithelial cells. Cell adhesion could be inhibited by preincubation of the collagen XIV substrate with heparin or with the chondroitin/dermatan sulfate proteoglycan decorin and by pretreatment of cells with chondroitinase ABC or heparinase III, suggesting a cell membrane proteoglycan as receptor. Affinity chromatography of125I-labeled fibroblast cell surface proteins on collagen XIV–Sepharose yielded a chondroitin/dermatan sulfate proteoglycan with a molecular mass of 97–105 kDa after chondroitinase ABC digestion and of 60–70 kDa after further treatment withN-glycosidase F. The eluates contained also some high-molecular-weight material that was susceptible to digestion with heparinase but no detectable integrins. Immunoprecipitation with a specific monoclonal antibody identified the prominent chondroitin/dermatan sulfate proteoglycan as a member of the CD44 family. The interaction between collagen XIV and cells appears to be finely tuned, since matrix-associated glycosaminoglycans, and particularly proteoglycans like decorin, could compete with cells for the binding site(s) on collagen XIV under physiological conditions.
