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Results for “Extracellular Matrix”

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PubMed2005

[Extracellular-superoxide dismutase production in mesangial cell growing in extracellular matrix].

To study the protective function against oxygen radicals in the mesangial area, we assessed extracellular superoxide dismutase (EC-SOD) production in mesangial cells (MCs) in vitro. These cells have a major protective function against oxygen radicals in the extracellular space. In two different kinds of culture conditions: "growth medium" with fetal cow serum, and "differentiation medium" with reduced growth factor, and four extracellular matrixes; type I collagen, type IV collagen, laminin and fibronectin, were added to the MC culture. With the difference in the culture media, differentiation medium induced EC-SOD hyper-production associated with the both of the slowing down of cell proliferation and the suppression of IL-6 and IL-8 production. With difference in the extracellular matrix, the presence of type VI collagen and laminin promoted higher production of EC-SOD than fibronectin and type I collagen. Type IV collagen and laminin associated with the physiological condition of the glomeruli promoted EC-SOD production compared with the presence of type I collagen and fibronectin dominantly located in pathological condition. Suppression of EC-SOD production in growth medium along with MC proliferation and chemokine hyper-production compared with production in differentiation medium might mimic reduction of the protective capacity against oxygen radical toxity during mesangial proliferation in the glomerular nephritis. MC proliferation with type I collagen and fibronectin might enhance oxygen radical toxity in the glomeruli, and accelerate glomerular sclerosis through the suppression of EC-SOD production.

Cell Proliferation↗

PubMed2002

Cells, rather than extracellular matrix, nucleate apatite in glutaraldehyde-treated vascular tissue.

Glutaraldehyde (GA) causes a large increase in [Ca(2+)](i) and [P(i)](i) and calcification of porcine aortic valve fibroblasts. Calcification in GA-treated vascular tissue is likely to begin intracellularly, but the potential role of extracellular matrix has not been taken into account in earlier studies. To compare the role of cells and matrix in calcification, intestinal pouches made of a lipid-extracted rat small intestine were prepared. Lipid-extracted porcine aortic valves, or cells cultured from those same valves, were placed in intestinal pouches, sealed, fixed with GA, and grafted in rat subcutis. Cells in the pouches calcified in 3 weeks whereas the valvular matrix did not calcify for 9 weeks. Cellular calcification spread to the wall of the intestinal pouches and grew heavier after 9 weeks. Similarly, smooth muscle cells calcified exclusively in GA-treated rat aorta grafted in rat subcutis for 3 weeks. Calcification of extracellular matrix was seen after 9 weeks. Cells initiate calcification and extracellular matrix serves as a substrate for the subsequent growth of apatite in GA-treated vascular tissue.

Animals↗

PubMedDate not supplied

The amphibian embryo: an experimental model for the in vivo analysis of interactions between embryonic cells and extracellular matrix molecules.

The early amphibian embryo provides an attractive model for the in vivo analysis of cell interactions with extracellular matrix components. During gastrulation, mesodermal cells use an anastomosing network of extracellular fibrils as substratum for their migration. These fibrils contain glycosaminoglycans and non collagenous proteins including laminin and fibronectin. The function of these extracellular components in the mesodermal cell migration process has been inferred from grafting experiments and microinjection of probes such as specific antibodies or GRGDS-containing peptides. Using the amphibian embryo as an experimental system, combination of microsurgical, cell behavioral and molecular approaches will provide new insights into cell-extracellular matrix interactions directing morphogenetic cell movements.

Amino Acid Sequence↗

PubMed1987

Further characterisation of the extracellular matrix in the mandibular condyle in neonatal mice.

This study provides newer information concerning the extracellular matrix of neonatal condylar cartilage--a genuine representative of a secondary type of cartilage. In addition, the data presented hereby indicate that the condylar cartilage contains a population of progenitor cells that synthesise Type I collagen rather than Type II. Under normal conditions in vivo local biomechanical factors influence the progenitor cells to differentiate into cartilage cells and thereby to shift their synthetic pathway from Type I collagen to Type II collagen--the typical collagen of cartilage extracellular matrix. In the absence of such biomechanical effects the condylar progenitor cells seem to proceed with their inherent differentiation pathway and express an osteogenic phenotype (Fig. 21).

Animals↗

PubMed2001

Homology and evolutionary novelty in the deployment of extracellular matrix molecules during pigment pattern formation in the salamanders Taricha torosa and T. rivularis (Salamandridae).

Salamander larvae exhibit a diverse array of pigment patterns shortly after hatching. Previous studies have identified roles for the extracellular matrix and lateral line sensory system in promoting the development of a phylogenetically common pattern of horizontal melanophore stripes. In contrast, salamanders in the genus Taricha exhibit evolutionarily derived pigment patterns and pattern-forming mechanisms. Taricha torosa larvae exhibit compact melanophore stripes that develop via redundant, lateral line-independent mechanisms, whereas T. rivularis larvae lack stripes and instead have melanophores uniformly distributed over the flank. In this study, I test roles for candidate patterning molecules of the extracellular matrix in promoting the development of species-specific pigment patterns in Taricha. I show that tenascin deposition is negatively correlated with melanophore distributions both intraspecifically and interspecifically: this matrix molecule is present where melanophores do not localize in T. torosa and is absent from these same regions where melanophores are abundant in T. rivularis. Embryological manipulations further indicate that transient expression of tenascin in a prospective interstripe region of T. torosa reflects a phylogenetically conserved effect of lateral line development. Finally, anti-laminin immunoreactivity is negatively correlated with melanophore distributions in T. torosa, and this species exhibits a general retardation of extracellular matrix development that may allow persistent, evolutionarily novel melanophore motility in this species. Together these findings identify tenascin and laminin, or molecules co-regulated with these matrix components, as candidates for promoting early larval pigment pattern development in Taricha.

Animals↗

PubMed1990

The extracellular matrix during neural crest formation and migration in rat embryos.

Changes in the distribution of extracellular matrix components have been investigated immunohistochemically during neural crest development in the rat. Inside the ectodermal epithelium basal lamina components are formed resulting in a separation of neurectoderm and epidermal ectoderm. Within the presumptive neural crest area fibronectin, hyaluronan and chondroitin sulphate become apparent. Upon subsequent neural crest migration the basal lamina becomes disrupted. As the neural crest cells take part in mesectoderm formation, fragments of the basal lamina remain attached to their surface, as is demonstrated with antibodies against laminin and collagen type IV. The extracellular matrix is therefore active both in the separation of neuroectoderm from epidermal ectoderm and in mesectoderm formation.

Animals↗

PubMed1996

Chemical and physical properties of the extracellular matrix are required for the actin ring formation in osteoclasts.

To examine the effect of extracellular matrix on osteoclast polarization, we focused on the actin organization in osteoclasts, using murine osteoclast-like multinucleated cells (OCLs) formed in cocultures of osteoblastic cells and bone marrow cells. When OCLs were cultured on either a plastic plate, calcified dentine, or calcium phosphate thin films in the presence of fetal bovine serum (FBS), they similarly formed ringed structures of F-actin dots (actin rings). However, OCLs placed on demineralized dentine or type I collagen gel matrix (collagen gel) failed to form actin rings. In the absence of FBS, actin ring formation in OCLs was induced on plastic plates coated with vitronectin, fibronectin, or type I collagen, but not on those coated with laminin, poly-L-lysine, or bovine serum albumin. Actin ring formation appeared to depend on integrins, since the GRGDS, but not the GRGES, peptide inhibited it in a dose-dependent manner. Moreover, immunoelectron microscopic examination revealed that vacuolar proton ATPase (V-ATPase) was localized along the apical membrane in much higher densities than the basolateral membrane in OCLs placed on plastic coverslips. In OCLs placed on collagen gel, however, V-ATPase was found to be distributed throughout the cytoplasm without polarity. These results suggest that actin ring formation in osteoclasts was dependent on matrix substrates, matrix proteins and integrins, and was closely related to osteoclast function.

Actins↗

PubMed1999

Cell-extracellular matrix interaction in glioma invasion.

Astrocytic tumours of the central nervous system express cell adhesion receptors of the integrin superfamily, CD44 and adhesion receptors of the immunoglobulin superfamily. Glioma cells utilize these receptors to adhere to and migrate along components of the extracellular matrix (ECM), which is uniquely distributed and regulated within the brain and the spinal cord. For penetration into healthy brain tissue a number of proteases are expressed, which degrade proteins of the extracellular matrix. Thus, glioma cell invasion into the adjacent brain tissue is dependent on the interaction of glioma cells with the extracellular matrix and the subsequent destruction of matrix barriers. There is a critical balance between expression of various adhesion receptors and proteases. The tight regulation of critical levels of proteases and receptors expressed by glioma cells or other cells is necessary for the "physiological" behaviour of glioma cells. Shifts in the balance of protein expression determine glioma cell behaviour in their micro-environment and can initiate or influence the complex process of glioma cell invasion. The complex receptor-ECM interaction in glioma cell invasion is discussed focussing upon the role of integrin receptors and matrix-metalloproteinases. Influencing these molecules or their regulation may lead to novel therapeutic approaches in the treatment of malignant glioma.

Animals↗

PubMed1990

Extracellular matrix disruption and pain after eccentric muscle action.

Pain, stiffness, and indicators of muscle damage occur at different times after eccentric muscle action. After a single bout of maximal resisted lengthening of the elbow flexors, elbow position, pain perception, and indicators of cellular damage were measured. Immediately postexercise, a significant decrease in resting muscle length was observed that continued to 48 h. At this time, an increase in perceived muscle soreness was noted (P less than 0.05), and a biopsy of the biceps brachii revealed mast cell degranulation, separations of the extracellular matrix from myofibers, and increased plasma constituents in the extracellular space. It is proposed that myofiber disruption allows intracellular proteins to escape and extracellular proteins and ions to enter, causing swelling, whereas the disrupted extracellular matrix initiates the inflammatory response, which includes the release of mast cell granules seen at 48 h postexercise. Thus the delayed sensation of pain (soreness) after repeated eccentric muscle actions probably results from inflammation in response to extracellular matrix disruption.

Adult↗

PubMed1997

Analysis of extracellular matrix proteins in malignant chicken cell lines.

The adherent chicken cell line, MDCC-MSB1-41C, was highly transplantable and metastatic in vivo, compared with the parental non-adherent cell line MDCC-MSB1 from Marek's disease (MD) lymphoblastoid tumor. For clarification of differences in extracellular matrix proteins in MSB1-41C and MSB1 cells, examination was made of various components of extracellular matrix proteins. A detachment experiment indicated the protein(s) recognizing the Arg-Gly-Asp (RGD) sequence, the minimum structure required for recognition by the cell-surface receptors, is essential for the adherent character. Immunoblot assay using antibodies showed increased expression of fibronectin, fibronectin receptors, and vinculin on MSB1-41C cell lines. RGD-directed integrins mediate important cell-cell adhesive interaction and these interactions with extracellular matrix proteins may thus possibly be requisite for migration, proliferation and metastatic dissemination of MDCC-MSB1-41C cells. The RGD-containing peptide in the culture medium could cause detachment of cultured adhesive lymphoid leukosis LSCC-1104X5 cells from the dish too.

Amino Acid Sequence↗

PubMed1989

Relationship between extracellular matrix interactions and degree of differentiation in human colon carcinoma cell lines.

Human colon carcinoma cell lines that vary in their degree of differentiation were examined for their ability to interact with extracellular matrix components. For this purpose, established cell lines were classified on the basis of several criteria that relate to degree of differentiation. These criteria include histology of the original tumor, histology of xenografts, in vitro morphology, and carcinoembryonic antigen expression. On this basis, the cell lines used were either moderately well or poorly differentiated. The poorly differentiated cell lines adhered to surfaces coated with laminin or reconstituted basement membrane extract (Matrigel) to a significantly greater extent than the moderately well differentiated lines with the exception of one moderately well differentiated line that was derived from a highly aggressive signet ring cell carcinoma. In addition, the poorly differentiated cell lines exhibited considerable spreading on laminin and Matrigel after adherence that was not evident for the moderately well differentiated lines. The adherence of these cell lines on fibronectin-coated surfaces did not correlate as well with differentiation although, in general, poorly differentiated cell lines adhered better than moderately well differentiated lines. None of the cells that adhered to fibronectin exhibited the extensive spreading seen on laminin. The specificity of tumor cell interactions with extracellular matrix glycoproteins was examined using synthetic peptides which correspond to sequences within these proteins that are recognized by cell surface receptors. The pentapeptide YIGSR-NH2 significantly inhibited the adherence and spreading of the tumor cell lines on laminin, but not on fibronectin. The peptide RGDS, however, did not inhibit tumor cell interactions with laminin although it did inhibit their interactions with fibronectin. Thus, the interactions of colon carcinoma cells with laminin and fibronectin are probably mediated by separate receptors. Taken together, the data demonstrate that cells derived from colon carcinomas exhibit considerable variation in their ability to interact with extracellular matrix components, and that this variability is related to the degree of differentiation of original tumor.

Carcinoembryonic Antigen↗

PubMed1992

Differential modulation of vascular cell integrin and extracellular matrix expression in vitro by TGF-beta 1 correlates with reciprocal effects on cell migration.

In vitro, BAEC and BASMC migratory phenotypes are known to be reciprocally modulated by both soluble factors and extracellular matrix proteins. In addition, integrin matrix receptors mediate endothelial and smooth muscle cell attachment and migration. To further elucidate these phenomena, we studied the effects of TGF-beta 1 on integrin expression by vascular BASMC and BAEC in tissue culture. TGF-beta 1 upregulated mRNA levels and surface pools of BASMC beta 3 integrin classes without modulating beta 1 integrin mRNA levels or expression of beta 1 integrin organization. In contrast to its effects on BASMC, TGF-beta 1 increased BAEC mRNA levels and surface expression of beta 1 and beta 3 integrins without altering their organization. Conversely, extracellular matrix components (fibronectin, laminin, and fibrinogen) organized cell surface integrins in both BASMC and BAEC without affecting the size of their cell surface pools. These data are consistent with the hypothesis that SMC and EC behavior in neointimal lesions may be modulated, in part, through a coordination of soluble factor and extracellular matrix protein regulation of integrin surface expression and organization.

Animals↗

PubMed2005

Recognition of extracellular matrix proteins by Paracoccidioides brasiliensis yeast cells.

The adhesion of microorganism to host cells or extracellular matrix (ECM) proteins is the first step in the establishment of an infectious process. Interaction between Paracoccidioides brasiliensis yeast cells and ECM proteins has been previously noted. In vivo, in the chronic phase of experimental paracoccidioidomycosis (PCM), laminin and fibronectin have been detected on the surface of yeast cells located inside granulomatous lesions. The aim of the present study was to examine the ability of P. brasiliensis yeast cells to interact with extracellular matrix proteins (laminin, fibrinogen and fibronectin) and to establish which molecules were involved in this interaction. Immunofluorescence microscopy and flow cytometry demonstrated that all three ECM proteins tested were able to bind to the surface of P. brasiliensis yeast cells. Treatment with trypsin, chymotrypsin, chitinase, proteinase K or different sugars resulted in no change in laminin binding. In addition, ligand affinity assays were performed using different yeast extracts (total homogenates, beta-mercaptoethanol, SDS extracts). These assays demonstrated the presence of 19 and 32-kDa proteins in the cell wall with the ability to bind to laminin, fibrinogen and fibronectin. This interaction could be important in mediating attachment of the fungus to host tissues and may consequently play a role in the pathogenesis of PCM.

Adhesiveness↗

PubMed1996

Degradation of human plasma and extracellular matrix fibronectin by tissue type plasminogen activator and urokinase.

Fibronectins and plasminogen activators, both tissue and urokinase types, are involved in the physiopathological degradation of the extracellular matrix. Previous reports indicate that fibronectin can be degraded by urokinase without plasminogen. Also, we have shown that tissue-type plasminogen activator can cleave fibronectin, without plasminogen, generating fragments of 30 and 220-250 kDa detectable by immunoblotting analysis. A comparison with urokinase-induced degradation indicates that the cleavage sites are the same for both plasminogen activators. One is close to the carboxyl-terminal, disrupting the fibronectin dimeric structure, and one is near the amino-terminal, generating a 30 kDa fragment. In solution, the activity of tissue-type plasminogen activator was prevalent on the amino-terminal site, while urokinase activity was prevalent on the carboxyl-terminal site. On fibronectin immobilized onto a gelatin coated surface, only the 30 kDa fragment was released when treated with both plasminogen activators. Plasminogen activators also were active on fibronectin assembled into the extracellular matrix of cultured fibroblasts. Urokinase caused the complete disappearance of extracellular matrix fibronectin, together with the release of the 30 and the 220-250 kDa fibronectin fragments, but left a flat morphology, while tissue-type plasminogen activator induced the release of the 30 kDa fragment associated with changes in cellular morphology. The plasminogen-independent fibronectin degradation exerted by tissue-type plasminogen activator and urokinase is 100 times lower than that exerted by plasmin. This may provide a mechanism for localized and limited degradation of fibronectin preventing the generalized proteolysis associated with plasminogen activation.

Fibronectins↗

PubMed1993

A pentapeptide from type I procollagen promotes extracellular matrix production.

The NH2 and COOH propieces of fibril-forming collagens are cleaved off extracellularly and have been implicated in feedback regulation of their own synthesis. Recently, we showed that a subfragment of the carboxyl-terminal propeptide of type I collagen (residues 197-241) dramatically augments extracellular matrix production in subconfluent fibroblasts. This stimulation of type I collagen, type III collagen, and fibronectin production occurred in a dose- and time-dependent manner with no effect on total protein synthesis or on the ratio of secreted proteins to cell-associated proteins (Katayama, K., Seyer, J.M., Raghow, R., and Kang, A.H. (1991) Biochemistry 30, 7097-7104). In the present report, we have extensively dissected this subfragment of the propeptide and found that the pentapeptide Lys-Thr-Thr-Lys-Ser (residues 212-216) is the minimum sequence necessary for potent stimulation of collagen and fibronectin production in a variety of mesenchymal cells. We postulate that the extracellular matrix production in fibroblasts may be subject to either positive or negative feedback regulation depending on the repertoire of specific proteases during postinflammatory tissue regeneration and fibrosis.

Amino Acid Sequence↗

PubMed1999

Biologic roles of gangliosides G(M3) and G(D3) in the attachment of human melanoma cells to extracellular matrix proteins.

The biologic functions of gangliosides G(M3) and G(D3) in the attachment of human melanoma cells to extracellular matrix proteins (type I and IV collagens, fibronectin, and laminin) were investigated by using the G(D3)-deficient mutant clone (SK-MEL-28-N1) and the parent cell line SK-MEL28. SK-MEL-28-N1 (N1) (high G(M3) expression: G(M3), 97.3%; G(D3), 0%) was selected by treating SK-MEL-28 (high G(D3) but low G(M3): G(M3), 6.5%, G(D3), 93.5%) with an anti-G(D3) monoclonal antibody (R24) and rabbit complement and subsequent subcloning of the surviving cells. The N1 clone showed significantly higher ability to adhere to type I and IV collagens and laminin than the parent clone SK-MEL-28. In the N1 clone, the expression of alpha2beta1 and alpha3beta1 integrin receptors was increased, whereas in SK-MEL-28, their expression was very low or undetectable. The treatment with monoclonal antibodies directed specifically to G(D3) expressed on SK-MEL-28 inhibited the cell attachment to type IV collagen (33% inhibition of control), fibronectin (59%), and laminin (71%). These findings suggest that gangliosides G(M3) (by influencing integrin receptor levels) and G(D3) (by interacting directly with matrix proteins) might play some functional roles in attachment to extracellular matrix proteins and thereby enhance the metastatic potency of melanoma cells.

Animals↗

PubMed1989

Immunolocalization of extracellular matrix proteins during brain tumor invasion in BD IX rats.

The distribution of several native extracellular matrix proteins (type I, III, and IV collagens and fibronectin) using immunofluorescent localization is described for in two different malignant gliomas (BT4A and BT4An). In addition, antibodies against denatured forms of type I and III collagens were used to localize areas of active degradation within the tumors. We have shown that both tumors express the native connective tissue components studied, although the distribution of these components within and between the tumors was different. In addition, native type I and III collagens and fibronectin were overexpressed in the tumors compared to the normal brain. Morphometry on immunostained type IV collagen sections showed an increase in vascular elements in both tumors compared to normal brain tissue. The BT4A tumor, which by light microscopy showed a degradative mode of invasion, expressed denatured type I and III collagens at the tumor-brain border zone, suggesting that this tumor has collagenolytic activity. The present article suggests that the distribution and changes in extracellular matrix protein synthesis and degradation may play an important role in the progressive growth of brain tumors in vivo.

Animals↗

PubMed1993

The extracellular matrix in diabetic nephropathy.

In the subgroup of diabetic patients who are destined to develop the full spectrum of the clinical syndrome of diabetic nephropathy, the kidney is afflicted with a series of distinct structural lesions principally involving the extracellular matrices. Diabetic nephropathy is characterized by hypertrophy of both glomerular and tubular elements, progressive accumulation of extracellular matrix components in the glomerular mesangium, and thickening of the glomerular and tubular basement membranes. Albeit less well recognized, progressive tubulointerstitial fibrosis is also a feature of the syndrome. Irrespective of pathogenetic mechanisms (be they metabolic, hemodynamic, or genetic), the structural changes involving the renal extracellular matrix compartments are believed to be the basis for the appearance of overt dysfunction, namely, proteinuria, hypertension, and renal failure. Therefore, a full understanding of the mechanisms that culminate in irreversible kidney failure requires a closer inspection of the status of the extracellular matrix in diabetes. This review outlines the different structural changes that typically occur during the course of the disease. Both glomerular and tubulointerstitial changes are reviewed. Valuable structural-functional correlations have been derived from examining kidney specimens obtained from patients with a wide spectrum of disease stages. Experimental animal models, supplanted with recent investigations in tissue culture on the effect of high ambient glucose levels, have increased our understanding of the cellular mechanisms that underlie the disordered matrix composition. Alterations in the metabolism of the collagens, proteoglycans, and other matrix constituents are reviewed.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗