Showing papers on "Extracellular matrix component published in 1989"
TL;DR: It is shown that bFGF associated with ECM is a required ECM component for ECM-mediated cell proliferation and differentiation and is inhibited by anti-bFGF antibodies but not byAnti-nerve growth factor antibodies or nonimmune rabbit IgG.
Abstract: Vascular endothelial cells (ECs) seeded sparsely on extracellular matrix (ECM) will proliferate in the absence of exogenous basic fibroblast growth factor (bFGF). This ECM will also stimulate neurite outgrowth in PC12 cells in the absence of exogenous growth factors. We have previously shown that bFGF is found in subendothelial ECM (Vlodavsky, I., J. Folkman, R. Sullivan, R. Fridman, R. Ishai-Michaeli, J. Sasse, and M. Klagsburn. 1987. Proc. Natl. Acad. Sci. USA. 84:2292-2296) and in basement membranes (Folkman, J., M. Klagsburn, J. Sasse, M. Wadzinski, D. Ingber, and I. Vlodavsky. 1988. Am. J. Pathol. 130:393-400). The actual requirement of ECM-associated bFGF for the growth of ECs and differentiation of PC12 cells was shown in two ways. First, polyclonal anti-bFGF antibodies added to subendothelial ECM inhibited both EC proliferation and PC12 neurite outgrowth. Secondly, PF-HR-9 cells, which do not synthesize bFGF and which produce an ECM not permissive for EC proliferation and PC12 neurite outgrowth, were transfected with bFGF cDNA. PF-HR-9 cells transfected with bFGF, but not with the dominant selectable marker SV2-neomycin, were found to express bFGF and to produce an ECM which did support both EC proliferation and PC12 differentiation. The ECM-mediated stimulatory effects were inhibited by anti-bFGF antibodies but not by anti-nerve growth factor antibodies or nonimmune rabbit IgG. These results indicate that bFGF associated with ECM is a required ECM component for ECM-mediated cell proliferation and differentiation.
185 citations
TL;DR: It is demonstrated that the gene encoding an extracellular matrix component contains two widely separated promoters controlling the generation of different transcripts in a tissue-specific fashion, providing a novel clue to answering the general question of what mechanisms are used to generate unique fibrillar patterns in different tissues.
139 citations
TL;DR: Evidence is obtained for a variety of structures not previously reported to exist on murine laminin including hybrid biantennary complex and biantENNary complex structures containing poly(lactosaminyl) repeating units.
Abstract: Laminin, a high molecular weight (1,000,000) glycoprotein component of basement membranes, was isolated from the EHS murine tumor as a noncovalent complex with entactin by lectin affinity chromatography using the alpha-D-galactosyl binding lectin Griffonia simplicifolia I (GS I). Entactin was removed from this complex by passage over Sephacryl S-1000 in the presence of SDS. Compositional analysis showed that the affinity-purified laminin contained 25-30% carbohydrate by weight. Methylation analysis revealed that the oligosaccharides of laminin contained bi- and triantennary chains, the blood group I structure, and repeating sequences of 3Gal beta 1,4GlcNAc beta 1 units. Free oligosaccharides were derived from the asparagine-linked glycans of affinity-purified laminin by hydrazinolysis, re-N-acetylation, and reduction with NaB3H4. When fractionated by affinity chromatography on concanavalin A (Con A)-Sepharose, 80% of the oligosaccharides passed through the column unretarded and a single peak corresponding to 20% of the oligosaccharides was adsorbed and specifically eluted with a linear gradient of 0-30 mM methyl alpha-D-glucopyranoside. Further fractionation of the Con A reactive oligosaccharides on GS I-Sepharose demonstrated that 70% of these oligosaccharides possess at least one terminal nonreducing alpha-D-galactopyranosyl unit. The Con A reactive oligosaccharides were subjected to sequential digestion with endo- and exoglycosidases, and the reaction products were analyzed by gel filtration chromatography on a column of Bio-Gel P4. We thereby obtained evidence for a variety of structures not previously reported to exist on murine laminin including hybrid biantennary complex and biantennary complex structures containing poly(lactosaminyl) repeating units. The poly(lactosaminyl) units occur either on one or on both branches of the biantennary chains, as well as in more highly branched blood group I poly(lactosamine) structures. All sialic acid is present as N-acetylneuraminic acid linked alpha 2,3 to galactose.
113 citations
Journal Article•
TL;DR: It is suggested that chemoattractants augment the expression of laminin receptors which mediate PMN attachment to basement membranes, followed by laminIn-induced increases in the expressionof cryptic chemoATTractant receptors contained in intracellular granules, with resultant augmentation of the oxidative burst.
Abstract: The extracellular matrix component, laminin, enhances the chemotactic responsiveness of polymorphonuclear leukocytes (PMN) in vitro, and low doses of chemoattractant substances augment the expression of PMN cell surface receptors for laminin. This study determined whether laminin acts in concert with chemoattractants to activate PMN. Laminin (5 to 100 micrograms/ml) stimulated lysozyme release and superoxide production in response to the chemoattractant, FMLP by as much as 69%. These results could be explained by changes in cell surface chemoattractant receptor expression in that incubation of normal PMN with laminin (5 to 75 micrograms/ml) increased the binding of 19 nM FML[3H]P by 35 to 80%. This corresponded to as much as a 2.5-fold increase in the number of chemoattractant receptors/cells which had a lower average affinity. Laminin did not change the number or affinity of FML[3H]P receptors present on organelle-depleted PMN cytoplasts, and the laminin-induced increase in FML[3H]P receptors expressed on PMN from a patient with a specific granule deficiency was only 11 to 21% of that seen in normal PMN. These findings suggest that chemoattractants augment the expression of laminin receptors which mediate PMN attachment to basement membranes, followed by laminin-induced increases in the expression of cryptic chemoattractant receptors contained in intracellular granules, with resultant augmentation of the oxidative burst.
37 citations
TL;DR: The biological fate of a bovine collagen implant (Zyderm Collagen Implant ZCI), injected subcutaneously into rats, was studied by the immunoperoxidase technique using specific antibodies against the bovin implant and against types I, III, IV, V collagens, fibronectin and elastin.
Abstract: The biological fate of a bovine collagen implant (Zyderm Collagen Implant ZCI), injected subcutaneously into rats, was studied by the immunoperoxidase technique using specific antibodies against the bovine implant and against types I, III, IV, V collagens, fibronectin and elastin. The implant remained in the animals until the end of the experiment (90 days), with no visible modification, as demonstrated by immunoperoxidase labelling and scanning electron microscopy. A slight inflammatory reaction was visible around the implant 24 h after injection and within the implant 3 days after injection. Fibroblast invasion began 7 days after injection. The chronology of the deposition in the implant of the host (rat) extracellular matrix components was as follows: by 24 h after injection, fibronectin was observed throughout the implant; types I and V collagens appeared on the 7th day, and, in contrast to surrounding connective tissue, type V collagen labelling was obtained without acid pretreatment of the section. Types III and IV collagens were detected inside the implant only 30 days after injection. At the end of the experiment (90 days), there was abundant types I and IV collagens after fibroblast migration, and abundant type IV collagen demonstrating an important vascularization. No elastic fibres could be detected inside the implant but they appeared as a dense network around the implant in host connective tissue.
35 citations
TL;DR: The results indicated that dexamethasone reduced the relative collagen synthesis and collagen mRNA levels in HSFs and increased the total incorporation of proline into proteins and reduced the mRNA level of glyceraldehyde-3-phosphate dehydrogenase, indicating that glucocorticoids and retinoids have both similar and different effects on gene expression in HSF.
Abstract: The effects of glucocorticoids and retinoids on connective tissue biosynthesis were studied in cultured human skin fibroblasts (HSFs). More specifically attention was paid to the effects of dexamethasone and 13-cis-retinoic acid (RA) on total protein and collagen synthesis and on collagen and fibronectin mRNA levels. The results indicated that dexamethasone reduced the relative collagen synthesis and collagen mRNA levels in HSFs and increased the total incorporation of proline into proteins, the latter effect being due to increased activity in the intracellular proline pool. 13-cis-RA did not affect collagen synthesis at the concentration studied (10-7
M) but it did reduce the corresponding mRNA levels. Simultaneous addition of both dexamethasone and 13-cis-RA or etretinate resulted in the largest decrease in type I and type III procollagen mRNA levels, indicating that retinoids do not oppose the effect of glucocorticoids on collagen synthesis in cultured HSFs. For comparison the effects of dexamethasone and 13-cis-RA on the mRNA levels of another extracellular matrix component, fibronectin, and of a constitutive enzyme, glyceraldehyde-3-phosphate dehydrogenase, were also studied. The results indicated, that dexamethasone treatment did not alter fibronectin mRNA levels in HSFs, while 13-cis-RA did so to a marked extent. Both dexamethasone and 13-cis-RA also reduced the mRNA level of glyceraldehyde-3-phosphate dehydrogenase, indicating that glucocorticoids and retinoids have both similar and different effects on gene expression in HSF.
28 citations
TL;DR: Laminin-containing pellets appeared to support appreciable axonal elongation in both systems, but this effect was dose-dependent and not exerted by collagen pellets, substrate-free pellets, or pellets containing irradiated laminin.
Abstract: Laminin is an extracellular matrix component which can promote neuritic elongation in vitro and has been implicated in the promotion of nerve regeneration in vivo. The present study was undertaken to determine if implantation of Elvax pellets containing exogenous laminin distal to site of lesion could promote regenerative responses in vivo in the adult rat peripheral (sciatic) and central (optic) nerve. In peripheral nerve preparations, Elvax pellets containing laminin or collagen were assessed for their ability to "lure" transected axons into 5-mm-long silicone tubes. In optic nerve studies, laminin pellets were inserted distal to site of nerve crush, and the extent of axonal elongation 2.5 mm to the injury site was assessed. Laminin-containing pellets appeared to support appreciable axonal elongation in both systems. This effect was dose-dependent and not exerted by collagen pellets, substrate-free pellets, or pellets containing irradiated laminin. Collagen IV had some beneficial effect in peripheral, but not central, nerve preparations.
17 citations
Patent•
13 Jan 1989
TL;DR: In this article, the authors used stationery culture in a medium for animal cell containing animal serum and antibiotics and 0.05-0.4mM ascorbic acid-2- phosphoric ester at pH 7-7.4 for >= 3 weeks and about 4 months to form tissue consisting of connective tissue and ECM (extracellular matrix component).
Abstract: PURPOSE:To obtain artificial tissue useful as artificial skin, artificial blood vessel, artificial bone or artificial liver, by cultivating cells for connective tissue in an ascorbic acid phosphoric ester-containing medium and forming tissues consisting of the connective tissue and ECM. CONSTITUTION:Cells of connective tissue such as fibroblast, smooth muscle cell, cartilage cell or endothelial cell is cultivated by stationery culture in a medium for animal cell containing animal serum and antibiotics and 0.01-5mM, preferably 0.05-0.4mM ascorbic acid phosphoric ester such as ascorbic acid-2- phosphoric ester at 35-38 deg.C at pH 7-7.4 for >=3 weeks and about 4 months to form tissue consisting of connective tissue and ECM (extracellular matrix component). The prepared artificial tissue is formed in a sheetlike state on the container wall of a culture container. The artificial tissue is directly used as it is and optionally separated into a sheetlike state by using EDTA, etc.
4 citations
01 Jan 1989
TL;DR: Although the aetiology of the fibrosis is not yet fully established, such an accumulation of inflammatory leukocytes is firmly implicated in the pathogenesis of the occupational lung diseases.
Abstract: Occupational exposure to harmful mineral dusts is frequently associated with development of chronic fibrotic lung disease e.g. silicosis, asbestosis or coal workers’ pneumoconiosis (Morgan and Seaton, 1984). Alveolitis is a characteristic feature of such diseases (Begin et al. 1986; Voisin et al. 1985) and although the aetiology of the fibrosis is not yet fully established, such an accumulation of inflammatory leukocytes is firmly implicated in the pathogenesis of the occupational lung diseases.
4 citations
01 Jan 1989
TL;DR: Hemopoietic progenitor cells circulate freely in the blood and are exposed to the microenvironments of virtually every organ of the body, but normally are confined to a limited number of organs that differ during various stages of ontogeny and in different species.
Abstract: Despite the fact that hemopoietic progenitor cells circulate freely in the blood and are exposed to the microenvironments of virtually every organ of the body, hematopoietic cell proliferation and differentiation normally is confined to a limited number of organs that differ during various stages of ontogeny and in different species.1–5 In humans, the yolk sac is the site of hemopoiesis in the early embryonic stages. The liver becomes the major hemopoietic organ during the end of the first trimester and through most of the second trimester, and the spleen has a minor hemopoietic role in the middle portion of fetal development. In the last trimester, the liver and spleen lose their capacity to support hemopoiesis.
3 citations
01 Jan 1989
TL;DR: Examination of inflammatory bronchoalveolar leukocytes lavaged from chrysotile asbestos-exposed lung is extended, in terms of ability to cause epithelial injury in vitro, to examine the ability of exogenous protease and mineral dust-elicited inflammatoryLeukocytes, to injure epithelial cells cultured on surfaces coated with purified extracellular matrix components.
Abstract: Deposition of mineral dust associated with the development of pneumoconiosis causes a range of changes in the lung parenchyma including alveolar inflammation and, in the longer term, septal fibrosis and epithelial abnormalities (Begin et al. 1986; Gibbs et al. 1984). We have been studying the role of inflammatory leukocytes in the development of pathology in dust-exposed lung and have previously reported on the ability of inflammatory bronchoalveolar leukocytes from rat lung, exposed by intratracheal installation to quartz, to cause proteolytic injury to cells of an alveolar epithelial cell line in vitro (Donaldson et al. 1988c). In the present paper we extend these studies by examining inflammatory bronchoalveolar leukocytes lavaged from chrysotile asbestos-exposed lung, in terms of ability to cause epithelial injury in vitro. We further report on the ability of bronchoalveolar leukocytes from lung exposed by the more appropriate inhalation route to coalmine dust, with the regard to causing epithelial injury and proteolytic degradation of fibronectin. In order to study the role of the extracellular matrix in epithelial injury in vitro, we have examined the ability of exogenous protease and mineral dust-elicited inflammatory bronchoalveolar leukocytes, to injure epithelial cells cultured on surfaces coated with purified extracellular matrix components.