SEARCH · PubMed Health

Results for “Extracellular Matrix”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 397 records · Page 22Linked to original sources

PubMed1999

Degradation of extracellular matrix by metastatic follicular thyroid carcinoma cell lines: role of the plasmin activation system.

The plasmin activation system plays a key role in extracellular matrix degradation in many malignant tumors. Because no data are available on the involvement of the plasmin activation system in matrix degradation by thyroid carcinoma, the present study was performed using follicular thyroid carcinoma cell lines obtained from a primary tumor (FTC-133) and metastases (FTC-236 and FTC-238) of one patient. Matrix degradation by these cell lines was studied assessing the release of radioactivity from S35-methionine labeled extracellular matrix coated onto plastic. The involvement of constituents of the plasmin activation system as well as matrix metalloproteinases (MMPs), another class of proteolytic enzymes, which can be activated by plasmin, were assessed by semiquantitative reverse transcriptase-polymerase chain reaction (RT-PCR) and zymography. In the matrix degradation experiment, S35 release by FTC-133 was significantly higher than FTC-236 and FTC-238. S35 degradation could be inhibited by the plasmin inhibitor aprotinin and by anti-human urokinase-type plasminogen activator (uPA) antibody, indicating the involvement of the plasmin activation system. Matrix degradation could also be inhibited by the MMP inhibitor marimastat, thus demonstrating the involvement of MMPs in matrix degradation by these cell lines. Zymographic assays revealed activity of uPA in all cell lines. However, in contrast with FTC-236 and FTC-238, no plasminogen activator inhibitor (PAI) or PAI1 mRNA were found in FTC-133. Therefore, the differences in PAI activity as observed between the cell lines may originate from differences in PAI1 gene transcription. Differences in PAI1 expression did not affect the attachment of these cell lines to vitronectin. We conclude that the plasmin activation system is involved in extracellular matrix degradation by these metastatic follicular thyroid carcinoma cell lines. Differences in extracellular matrix degradation between the cell lines correspond with differences in PAI1 gene expression, indicating the significance of PAI1 in extracellular matrix degradation by metastatic follicular thyroid carcinoma.

Adenocarcinoma, Follicular↗

PubMed1989

Extracellular matrix organization modulates fibroblast growth and growth factor responsiveness.

To learn more about the relationship between extracellular matrix organization, cell shape, and cell growth control, we studied DNA synthesis by fibroblasts in collagen gels that were either attached to culture dishes or floating in culture medium during gel contraction. After 4 days of contraction, the collagen density (initially 1.5 mg/ml) reached 22 mg/ml in attached gels and 55 mg/ml in floating gels. After contraction, attached collagen gels were well organized; collagen fibrils were aligned in the plane of cell spreading; and fibroblasts had an elongated, bipolar morphology. Floating collagen gels, however, were unorganized; collagen fibrils were arranged randomly; and fibroblasts had a stellate morphology. DNA synthesis by fibroblasts in contracted collagen gels was suppressed if the gels were floating in medium but not if the gels were attached, and inhibition was independent of the extent of gel contraction. Therefore, growth of fibroblasts in contracted collagen gels could be regulated by differences in extracellular matrix organization and cell shape independently of extracellular matrix density. We also compared the responses of fibroblasts in contracted collagen gels and monolayer culture to peptide growth factors including fibroblast growth factor, platelet-derived growth factor, transforming growth factor-beta, and interleukin 1. Cells in floating collagen gels were generally unresponsive to any of the growth factors. Cells in attached collagen gels and monolayer culture were affected similarly by fibroblast growth factor but not by the others. Our results indicate that extracellular matrix organization influenced not only cell growth, but also fibroblast responsiveness to peptide growth factors.

Cell Adhesion↗

PubMed1994

Targeting of the immunoglobulin-binding domain of protein A to the extracellular matrix using a minifibronectin expression vector.

A truncated form of fibronectin consisting of the N-terminal 70-kDa and C-terminal 37-kDa regions, referred to as "minifibronectin," retains the ability to assemble into the extracellular matrix, even though it lacks the central approximately 120-kDa region containing most of the type III modules (Ichihara-Tanaka, K., Titani, K., and Sekiguchi, K., FEBS Lett. 299, 155-158, 1992). Taking advantage of the matrix assembly activity of minifibronectin, we developed a novel method to target non-matrix proteins to the extracellular matrix by inserting them between the N-terminal 70-kDa and the C-terminal 37-kDa regions of minifibronectin. Using the immunoglobulin-binding domain of Staphylococcal protein A as a model, we demonstrated that the bacterial protein expressed in mouse L cells as a chimeric protein with minifibronectin is secreted as disulfide-bonded dimers and successfully deposited onto the extracellular matrix of transfected cells. The chimeric protein retained the immunoglobulin-binding activity not only in solution but also after deposition at the matrix. This targeting strategy we developed will provide a means to manipulate the biological functions of the extracellular matrix through targeting of a wide variety of non-matrix proteins.

Animals↗

PubMed2005

Nanoarchitectures of the animal extracellular matrix: opportunities for synchrotron radiation studies on collagen and fibrillin.

The extracellular matrix comprises structures that support the architectural organization of virtually all animal tissues. Within this architecture, two classes of protein assemblies found as long slender fibrils (collagen and fibrillin) characterize the bulk of the extracellular matrix. In both classes of fibrous protein, the molecular organization within a fibril ensures that the properties of the individual molecules transcend to the nanostructural and mesoscopic levels of structural organization and thence the tissue itself. The composition of the fibrils, in conjunction with other biomolecules and their suprafibrillar architecture, facilitates the formation of tissues as diverse as skin, tendon, cornea ciliary zonules and aorta. Here the relative tear resistance, strength, transparency and optical properties are paramount for proper function. Many structural investigations of fibrous protein structure have relied heavily on the use of synchrotron radiation in order to elucidate molecular packing, primarily due to the distinct benefits that X-ray diffraction provides, such as minimal sample preparation, rapid data collection and in situ mechanical testing. In this paper, an overview of the investigations that have revealed different levels of molecular architecture in fibril-based tissues is presented. Emerging future technology and how this can be matched with the pressing questions in extracellular matrix biology are also discussed.

Animals↗

PubMed1998

Regulation of cellular adhesion to extracellular matrix proteins by galectin-3.

The control of cellular adhesion to extracellular matrix proteins is poorly understood. In the present analyses, we set out to test the hypothesis that high galectin-3 concentration on the cell surface downregulates cellular adhesion to the extracellular matrix proteins. Various tumor cell lines were briefly incubated without or with galectin-3 and then allowed to adhere to wells coated with laminin-1, collagen IV and fibronectin. Our data demonstrated that the cells which were incubated with galectin-3 prior to plating had significantly reduced adhesion to extracellular matrix proteins. This inhibition involved the carbohydrate recognition domain of the lectin because adhesion was achieved in the presence of galectin-3 and lactose but not galectin-3 and sucrose. Furthermore we demonstrated that galectin-3 associates with alpha 1 beta 1 integrin in a lactose dependent manner.

Animals↗

PubMed2004

Smooth muscle cell biglycan overexpression results in increased lipoprotein retention on extracellular matrix: implications for the retention of lipoproteins in atherosclerosis.

Lipoprotein retention on extracellular matrix (ECM) may play a central role in atherogenesis, and a specific extracellular matrix proteoglycan, biglycan, has been implicated in lipoprotein retention in human atherosclerosis. To test whether increased cellular biglycan expression results in increased retention of lipoproteins on ECM, rat aortic smooth muscle cells (SMCs) were transduced with a human biglycan cDNA-containing retroviral vector (LBSN) or with an empty retroviral vector (LXSN). To assess the importance of biglycan's glycosaminoglycan side chains in lipoprotein retention, ECM binding studies were also performed using RASMCs transduced with a retroviral vector encoding for a mutant, glycosaminoglycan-deficient biglycan (LBmutSN). Human biglycan mRNA and protein were confirmed in LBSN and LBmutSN RASMCs by Northern and Western blot analyses. HDL3+E binding to SMC ECM was increased significantly (as determined by 95% confidence intervals for binding curves) for LBSN as compared to either LXSN or LBmutSN cells; the increases for LBSN cell ECM were due primarily to an approximately 50% increase in binding sites (increased Bmax) versus LXSN cell ECM and of approximately 25% versus LBmutSN cell ECM. These results are consistent with the hypothesis that biglycan, through its glycosaminoglycan side chains, may mediate lipoprotein retention on atherosclerotic plaque ECM.

Animals↗

PubMed1997

Deposition of extracellular matrix on intraocular lenses in rabbits: an immunohistochemical and transmission electron microscopic study.

BACKGROUND: We examined by transmission electron microscopy the accumulation of extracellular matrix on intraocular lenses (IOLs) implanted experimentally into rabbit eyes, and evaluated the immunolocalization of such extracellular matrix components as collagen types I, III, and IV, and cellular fibronectin on these IOLs. METHODS: Phacoemulsification and aspiration of the crystalline lens were performed and an IOL was implanted into the capsular bag of each eye of each of 16 adult albino rabbits under general anesthesia. After up to 12 weeks, the animals were killed and the IOLs were removed. Specimens were processed for transmission electron microscopy or for immunohistochemical detection collagen types I, III, and IV, and cellular fibronectin. RESULTS: Transmission electron microscopy revealed an accumulation of extracellular matrix between the residual anterior lens capsule and the surface of an IOL explanted 4 weeks after surgery. Collagen types I and III and cellular fibronectin were detected immunohistochemically on each IOL in association with cellular deposits. Type IV collagen-immunoreactive matrix was not seen on the optic portion, but was detected on the haptic portion of one of six IOLs examined. CONCLUSION: Each component of the extracellular matrix that is deposited on the IOL supplies scaffolding for the adhesion and proliferation of cells. These components are considered to be produced by cells such as lens epithelial cells and macrophages that adhere to the IOL surface.

Animals↗

PubMed1995

Cytoskeletal filament assembly and the control of cell spreading and function by extracellular matrix.

This study was undertaken to analyze how cell binding to extracellular matrix produces changes in cell shape. We focused on the initial process of cell spreading that follows cell attachment to matrix and, thus, cell 'shape' changes are defined here in terms of alterations in projected cell areas, as determined by computerized image analysis. Cell spreading kinetics and changes in microtubule and actin microfilament mass were simultaneously quantitated in hepatocytes plated on different extracellular matrix substrata. The initial rate of cell spreading was highly dependent on the matrix coating density and decreased from 740 microns 2/h to 50 microns 2/h as the coating density was lowered from 1000 to 1 ng/cm2. At approximately 4 to 6 hours after plating, this initial rapid spreading rate slowed and became independent of the matrix density regardless of whether laminin, fibronectin, type I collagen or type IV collagen was used for cell attachment. Analysis of F-actin mass revealed that cell adhesion to extracellular matrix resulted in a 20-fold increase in polymerized actin within 30 minutes after plating, before any significant change in cell shape was observed. This was followed by a phase of actin microfilament disassembly which correlated with the most rapid phase of cell extension and ended at about 6 hours; F-actin mass remained relatively constant during the slow matrix-independent spreading phase. Microtubule mass increased more slowly in spreading cells, peaking at 4 hours, the time at which the transition between rapid and slow spreading rates was observed. However, inhibition of this early rise in microtubule mass using either nocodazole or cycloheximide did not prevent this transition. Use of cytochalasin D revealed that microfilament integrity was absolutely required for hepatocyte spreading whereas interference with microtubule assembly (using nocodazole or taxol) or protein synthesis (using cycloheximide) only partially suppressed cell extension. In contrast, cell spreading could be completely inhibited by combining suboptimal doses of cytochalasin D and nocodazole, suggesting that intact microtubules can stabilize cell form when the microfilament lattice is partially compromised. The physiological relevance of the cytoskeleton and cell shape in hepatocyte physiology was highlighted by the finding that a short exposure (6 hour) of cells to nocodazole resulted in production of smaller cells 42 hours later that exhibited enhanced production of a liver-specific product (albumin). These data demonstrate that spreading and flattening of the entire cell body is not driven directly by net polymerization of either microfilaments or microtubules.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗

PubMed1997

Extracellular matrix is reduced by inhibition of transforming growth factor beta1 in pancreatitis in the rat.

BACKGROUND & AIMS: Regeneration from cerulein-induced pancreatitis is accompanied by a transient synthesis and deposition of extracellular matrix components in the rat pancreas. The pleiotropic transforming growth factor (TGF)-beta1 has been suggested to regulate extracellular matrix remodeling during regeneration from acute pancreatitis. The present study was designed to verify this hypothesis by investigating the effect of TGF-beta1 inhibition. METHODS: Experimental acute pancreatitis was induced in rats by supramaximal doses of cerulein. The biological activity of TGF-beta1 was inhibited by injections of neutralizing TGF-beta1 antibody. Changes in the content of extracellular matrix proteins, TGFs, and their messenger RNA concentrations were monitored. RESULTS: TGF-beta1 expression in pancreatic cells was suppressed after induction of acute pancreatitis by the application of neutralizing TGF-beta1 antibody. Immunochemical analysis showed a clear reduction of extracellular matrix formation during the regeneration of the pancreas in antibody-treated animals. The hydroxyproline content and the concentration of collagen types I and III, fibronectin on protein, and messenger RNA level were significantly reduced in the pancreas of treated animals. CONCLUSIONS: These results provide evidence that TGF-beta1 is involved in the regulation of extracellular matrix remodeling in the rat pancreas during regeneration from acute pancreatitis.

Acute Disease↗

PubMed1994

[Interdependence of the immune system and structure of extracellular matrix proteins].

The major proteins from plasma and extracellular matrices (ECM) are described. The interaction of lymphoid cells with their microenvironment is critical for their growth and function. The interaction with ECM may play a significant role in defining the biological properties of many cells. ECM form a network of bioactive proteins, that is being linked with an increasing number of processes, including antigen-independent activation, proliferation, homing and cell migration. Some aspects of the participation of the extracellular matrix in the language of intracellular communication is discussed.

Cell Communication↗

PubMed1985

Glycosaminoglycan production in cultures of early and late passage human endothelial cells: the influence of an anionic endothelial cell growth factor and the extracellular matrix.

An endothelial cell (EC) growth factor isolated from bovine brain stimulates in vitro growth of human umbilical vein endothelial cells, and permits long term serial propagation. In the presence of increasing concentrations of EC growth factor, confluent cultures of early (CPDL less than or equal to 20) and late (CPDL greater than 20) passage human endothelial cells exhibit an increased incorporation of 3H-glucosamine and Na235SO4 into the glycosaminoglycans (GAG), hyaluronic acid, chondroitin, chondroitin-4-sulfate, dermatan-4-sulfate, and chondroitin-6-sulfate. An increase in both labelled sulfated and nonsulfated GAG was observed in the cytosol, membrane, secreted and extracellular matrix fractions. In contrast, endothelial cells grown in the presence of EC growth factor contained decreased amounts of labelled heparan sulfate than cells grown without EC growth factor. Confluent cultures of early passage cells had significantly more labelled GAG but significantly less heparan sulfate than cultures of late passage cells on a per cell basis. Extracellular matrix from early passage cells contained about two- to seven-fold more labelled GAG than extracellular matrix from late passage cells, but only about half as much labelled heparan sulfate. Cell adhesion was enhanced when cells were grown in the presence of EC growth factor as compared to adhesion of cells grown without EC growth factor. Conversely, trypsin-mediated detachment of cells grown in the presence of growth factor was inhibited as compared to detachment of cells grown in medium without EC growth factor. The composition of the extracellular matrix influenced incorporation of labelled GAG into extracellular matrix. Early passage cells grown to confluence on a matrix from late passage cells incorporated significantly less labelled GAG into extracellular matrix than when grown to confluence on matrix from early passage cells. Incorporation of labelled GAG into extracellular matrix was significantly higher when late passage cells were grown on a matrix from early passage endothelial cells than when grown on matrix from late passage cells. We conclude that EC growth factor selectively stimulates incorporation of isotopic precursors into GAG in cultures of early and late passage endothelial cells but inhibits incorporation of radiolabel into heparan sulfate; early passage cells contain more GAG but less heparan sulfate than late passage cells, extracellular matrix controls the amount of GAG and heparan sulfate incorporated into matrix.(ABSTRACT TRUNCATED AT 400 WORDS)

Cell Adhesion↗

PubMed2000

Extracellular matrix and growth factors during heart growth.

The effects of growth factors on tissue remodeling and cell differentiation depend on the nature of the extracellular matrix, the type and organization of integrins, the activation of metalloproteinases and the presence of secreted proteins associated to the matrix. These interactions are actually poorly known in the cardiovascular system. We describe here: 1) the main components of extracellular matrix within the cardiovascular system; 2) the role of integrins in the transmission of growth signals; 3) the shift in the expression of the components of the extracellular matrix (fibronectin and collagens) and the stimulation of the synthesis of metalloproteinases during normal and hypertrophic growth of the myocardium; 4) the effects of growth factors, such as Angiotensin II, Fibroblast Growth Factors (FGF), Transforming Growth Factor-beta (TGF-beta), on the synthesis of proteins of the extracellular matrix in the heart.

Animals↗

PubMed2005

Extracellular matrix of ostrich articular cartilage.

The composition and organization of the extracellular matrix of ostrich articular cartilage was investigated, using samples from the proximal and distal surfaces of the tarsometatarsus. For morphological analysis, sections were stained with toluidine blue and analyzed by polarized light microscopy. For biochemical analysis, extracellular matrix components were extracted with 4 M guanidinium chloride, fractionated on DEAE-Sephacel and analyzed by SDS-PAGE. Glycosaminoglycans were analyzed by electrophoresis in agarose gels. Structural analysis showed that the fibrils were arranged in different directions, especially on the distal surface. The protein and glycosaminoglycan contents of this region were higher than in the other regions. SDS-PAGE showed the presence of proteins with molecular masses ranging from 17 to 121 kDa and polydisperse components of 67, 80-100, and 250-300 kDa in all regions. The analysis of glycosaminoglycans in agarose-propylene diamine gels revealed the presence of only chondroitin-sulfate. The electrophoretic band corresponding to putative decorin was a small proteoglycan containing chondroitin-sufate and not dermatan-sulfate, unlike other cartilages. The higher amounts of proteins and glycosaminoglycans and the multidirectional arrangement of fibrils seen in the distal region may be correlated with the higher compression normally exerted on this region.

Animals↗

PubMed2003

Microfluidic patterning of cells in extracellular matrix biopolymers: effects of channel size, cell type, and matrix composition on pattern integrity.

The organization of cells within an extracellular matrix is critical to promote appropriate cellular interactions and tissue function in vivo. The ability to design and create biologically relevant cellular arrangements via microfluidic patterning on surfaces provides new capabilities for tissue engineering and biomimetics. The purpose of this article is to describe techniques using microfluidic patterning of three-dimensional biopolymer matrices to improve cellular pattern integrity and to provide microscale control over cellular microenvironments. Results demonstrated that the incorporation of extracellular matrix biopolymers in cell microfluidic patterning results in a more stable pattern of adherent human endothelial cells than patterning without matrix components after several days in vitro. This may be important for carrying out long-term biological experiments and tissue engineering in vitro. Moreover, chemical components in the patterned biopolymer matrices, such as collagen, chitosan, and fibronectin, influenced the ability of the matrices to control cell migration and pattern stability over time. Thus, microfluidic patterning of cells in extracellular matrix biopolymers was shown to be useful in patterning multiple cell types in well-defined three-dimensional geometries.

Biopolymers↗

PubMed1997

Extracellular matrix proteins induce changes in intracellular calcium and cyclic AMP signalling systems in cultured human keratinocytes.

The purpose of this study was to investigate whether extracellular matrix proteins which influence human keratinocyte behaviour are capable of altering intracellular signalling systems in these cells. The effects of extracellular matrix proteins on two major signal transduction pathways, intracellular calcium and cyclic adenosine monophosphate (cyclic AMP), were investigated. The extracellular matrix proteins examined were the basement membrane preparation matrigel, collagens type I and IV, vitronectin and its active tripeptide component Arg-Gly-Asp (RGD). Acute additions of matrigel, vitronectin and RGD caused rapid transient increases in intracellular calcium and, together with collagen type I, also caused sustained elevations in basal calcium when cells were grown on these substrates. Cyclic AMP production was unaffected by acute exposure to these extracellular matrix proteins. Culture of cells on matrigel, collagen type I or IV, however, significantly reduced basal cyclic AMP accumulation and increased the response of the cells to the receptor-independent agonist forskolin. It is concluded that in vitro some extracellular matrix proteins can initiate both acute and sustained changes in intracellular signalling in human keratinocytes.

Calcium↗

PubMed1998

Effect of latanoprost on the extracellular matrix of the ciliary muscle. A study on cultured cells and tissue sections.

Prostaglandin F2alpha and its analogue latanoprost, both prostanoid FP receptor agonists, reduce the intraocular pressure mainly by enhancing uveoscleral outflow. Changes in the extracellular matrix of the ciliary muscle may be involved in the increased outflow. The effect of latanoprost and prostaglandin F2alpha on the extracellular matrix of the ciliary muscle was investigated. Cell cultures of human ciliary muscle were treated with latanoprost acid or prostaglandin F2alpha for 1-2 days and were immunostained against various extracellular matrix components and metalloproteinases. Proteinases were also analysed by zymography and by measuring plasmin generating ability. For comparison, matrix components were immunolocalized on tissue sections from monkey eyes, treated topically once daily with latanoprost for 10 days. In response to both prostaglandins collagens I, III, and IV, fibronectin, laminin and hyaluronan were reduced, while metalloproteinase -2 and -3 were increased. Zymography demonstrated the presence of functionally active metalloproteinase -2. Both prostaglandins enhanced the generation of plasmin, an activator of metalloproteinases. In the anterior part of the ciliary muscle in latanoprost-treated eyes immunostained collagen VI was decreased in 5 out of 5 monkeys and collagen IV was decreased in 4 of the 5 monkeys. These results suggest a role for latanoprost in the remodeling of extracellular matrix in the ciliary muscle. A latanoprost-induced change in the extracellular matrix might augment the flow of aqueous humour through the ciliary muscle bundles of the uveoscleral pathway.

Aged↗

PubMed1986

Extracellular matrix proteoglycans and cell-substratum adhesion of human endothelial cells: the effect of methyl beta-D-xylopyranoside.

The influence of methyl beta-D-xylopyranoside on human endothelial cell proteoglycans isolated from the medium and extracellular matrix was investigated. Confluent cultures of human endothelial cells incorporate significant amounts of heparan sulfate (78%), chondroitin sulfate (10%), and dermatan sulfate (12%) into the extracellular matrix. Chondroitin sulfate (35%) and dermatan sulfate (37%) were the major glycosaminoglycans present in the medium. In the presence of methyl beta-D-xylopyranoside, incorporation of labeled proteoglycans into extracellular matrix was diminished by approximately 70%. Heparan sulfate comprised the major proteoglycan present in extracellular matrix (89%) in cells grown in the presence of methyl beta-D-xylopyranoside. In contrast to the incorporation of proteoglycan into extracellular matrix, methyl beta-D-xylopyranoside stimulated the secretion of labeled glycosaminoglycan chains into the medium 2.5-fold. In the presence of methyl beta-D-xylopyranoside, secretion of chondroitin sulfate into the medium was markedly stimulated, with a slight increase in secretion of heparan sulfate. Chondroitin sulfate (62%) and heparan sulfate (34%) were the major labeled glycosaminoglycans present in medium from methyl beta-D-xylopyranoside-treated cultures. The effect of methyl beta-D-xylopyranoside on cell adhesion and detachment was investigated. Cell detachment from extracellular matrix depleted of proteoglycan was significantly faster than detachment from normal matrix. Conversely, human endothelial cells adhered faster to normal matrix than to matrix depleted of proteoglycan.

Cell Adhesion↗

PubMed1995

Bacterial plasminogen receptors: in vitro evidence for a role in degradation of the mammalian extracellular matrix.

The potential of bacterium-bound plasmin to degrade mammalian extracellular matrix and to enhance bacterial penetration through basement membrane was assessed with the adherent strain SH401-1 of Salmonella enterica serovar Typhimurium. Typhimurium SH401-1 was able to bind plasminogen and to enhance the tissue-type plasminogen activator-mediated activation of the single-chain plasminogen to the two-chain plasmin. The end product, the enzymatically active, bacterium-bound plasmin activity, was also formed in a normal human plasma milieu in the presence of exogenous tissue-type plasminogen activator, indicating that plasmin was protected from the plasminogen activator inhibitors and plasmin inhibitors of plasma. Plasmin bound on Typhimurium cells degraded 125I-labeled laminin as well as 3H-labeled extracellular matrix prepared from the human endothelial cell line EA.hy926. The degradations were not seen with Typhimurium cells without plasminogen and were inhibited by the low-molecular-weight plasmin inhibitor aprotinin. Plasmin bound on Typhimurium cells also potentiated penetration of bacterial cells through the basement membrane preparation Matrigel reconstituted on membrane filters. The results give in vitro evidence for degradation of the mammalian extracellular matrix by bacterium-bound plasmin and for a pathogenetic role for bacterial plasminogen receptors.

Extracellular Matrix↗