The extracellular matrix of human amniotic epithelium: ultrastructure, composition and deposition

1985 ◽  
Vol 79 (1) ◽  
pp. 119-136
Author(s):  
J.D. Aplin ◽  
S. Campbell ◽  
T.D. Allen
Keyword(s):  
Extracellular Matrix ◽  
Epithelial Cells ◽  
Basal Lamina ◽  
Basal Cell ◽  
Type I ◽  
Type Iv ◽  
Cell Processes ◽  
Complete Matrix

Ultrastructural comparisons have been made between human amnion extracellular matrix in tissue and cell culture. Immunochemical analysis of matrix deposited by monolayers of cultured amnion epithelial cells has also been undertaken. The basal cell surfaces are highly invaginated with an associated basal lamina that is more electron dense at the distal tips of basal cell processes where hemidesmosomes are frequent. Immediately below the lamina densa is a zone rich in collagen bundles. In the underlying stroma two types of fibril predominate, one striated of 50 nm diameter and one of 18 nm diameter. The observations suggest that at gestational term the epithelial cells are still active in the production of matrix. Secretion appears to occur into invaginations in the basal cell surface where a loosely organized mixture of stromal-type and basal laminal-type aggregates is formed. In culture on plastic, cells also deposit a mixture of basal laminal (type IV collagen + laminin) and stromal (collagens type I + III) components as well as fibronectin. However, segregation into a true basal lamina with underlying stroma does not occur in vitro, suggesting the need for an organized subcellular template to complete matrix morphogenesis. The in vitro and in vivo evidence suggest that the epithelium contributes to the subjacent dense collagenous zone as well as to the basal lamina.

scholarly journals Shift in collagen type as an early response to induction of the metanephric mesenchyme.

1981 ◽  
Vol 89 (2) ◽  
pp. 276-283 ◽  
Author(s):  
P Ekblom ◽  
E Lehtonen ◽  
L Saxén ◽  
R Timpl
Keyword(s):  
Basal Lamina ◽  
Type Iv Collagen ◽  
Early Response ◽  
Type I ◽  
Metanephric Mesenchyme ◽  
Type Iv ◽  
Interstitial Collagens ◽  
Membrane Components

Conversion of the nephrogenic mesenchyme into epithelial tubules requires an inductive stimulus from the ureter bud. Here we show with immunofluorescence techniques that the undifferentiated mesenchyme before induction expresses uniformly type I and type III collagens. Induction both in vivo and in vitro leads to a loss of these proteins and to the appearance of basement membrane components including type IV collagen. This change correlates both spatially and temporally with the determination of the mesenchyme and precedes and morphological events. During morphogenesis, type IV collagen concentrates at the borders of the developing tubular structures where, by electron microscopy, a thin, often discontinuous basal lamina was seen to cover the first pretubular cell aggregates. Subsequently, the differentiating tubules were surrounded by a well-developed basal lamina. No loss of the interstitial collagens was seen in the metanephric mesenchyme when brought into contact with noninducing tissues or when cultured alone. Similar observations were made with nonnephrogenic mesenchyme (salivary, lung) when exposed to various heterotypic tissues known to induce tubules in the nephrogenic mesenchyme. The sequential shift in the composition of the extracellular matrix from an interstitial, mesenchymal type to a differentiated, epithelial type is so far the first detectable response of the nephrogenic mesenchyme to the tubule-inducing signal.

scholarly journals Extracellular matrix of the human thymus: immunofluorescence studies on frozen sections and cultured epithelial cells.

1985 ◽  
Vol 33 (7) ◽  
pp. 655-664 ◽  
Author(s):  
S Berrih ◽  
W Savino ◽  
S Cohen
Keyword(s):  
Extracellular Matrix ◽  
Epithelial Cells ◽  
Type Iv Collagen ◽  
Type I Collagen ◽  
Basement Membranes ◽  
Thymic Epithelial Cells ◽  
Perivascular Spaces ◽  
Type I ◽  
Type Iv

The immunohistochemical detection of elements of the human thymic extracellular matrix in situ and in vitro is described. In the normal thymus, the intracapsular and intraseptal fibers were strongly labeled by anti-type I collagen antiserum. Basement membranes bordering the capsule, septae, and perivascular spaces were intensely stained by anti-type IV collagen, anti-fibronectin, and anti-laminin sera. In hyperplastic myasthenia gravis thymuses, the major changes consisted of discontinuities of the basement membrane adjacent to clusters of epithelial (keratin-containing) cells, among which an unusual connective framework (densely labeled by all the antisera) was observed. In vitro, most epithelial cells were strongly labeled by antifibronectin serum and to a lesser extent by the anti-type IV collagen and anti-laminin sera. In addition, fibronectin, laminin, and type IV collagen were detected in the intercellular spaces bordering the epithelial cells in culture. Results show that thymic epithelial cells participate in the synthesis of extracellular matrix elements, which as a result of their localization and influence on epithelial cell growth, should be regarded as constitutive components of the thymic microenvironment.

Extracellular matrix modulation of endothelial cell shape and motility following injury in vitro

1985 ◽  
Vol 73 (1) ◽  
pp. 19-32
Author(s):  
W.C. Young ◽  
I.M. Herman
Keyword(s):  
Extracellular Matrix ◽  
Basement Membrane ◽  
Fluorescence Microscopy ◽  
Type Iv Collagen ◽  
Type I ◽  
Post Injury ◽  
Type Iv ◽  
Interstitial Collagens

We utilized fluorescence microscopy and affinity-purified antibodies to probe the form and function of cytoplasmic actin in endothelial cells (EC) recovering from injury and grown on extracellular matrices in vitro. Bovine aortic EC were seeded onto glass microscope coverslips that had been coated with either BSA, fibronectin, type I and III (interstitial) collagens, type IV (basement membrane) collagen or gelatin. After EC that had been grown on glass, glass-BSA or extracellular matrix-coated coverslips reached confluence, a 300–400 micron zone of cells was mechanically removed to stimulate EC migration and proliferation. Post-injury EC movements were monitored with time-lapse, phase-contrast videomicrography before fixation for actin localization with fluorescence microscopy using affinity-purified antibodies. We found that the number of stress fibres within EC was inversely proportional to the rate of movement; and, the rates of movement for EC grown on glass or glass-BSA were approximately eight times faster than EC grown on gelatin or type IV collagen (X velocity = 0.5 micron/min versus 0.06 micron/min). EC movements on fibronectin and interstitial collagens were similar (X velocity = 0.2 micron/min). These results suggest that extracellular matrix molecules modulate EC stress fibre expression, thereby producing alterations in the cytoskeleton and the resultant EC movements that follow injury in vitro. Moreover, the induction of stress fibres in the presence of basement membrane (type IV) collagen may explain the failure of aortic EC to migrate and repopulate wounded regions of intima during atherogenesis in vivo.

scholarly journals Activation of transmembrane receptor tyrosine kinase DDR1-STAT3 cascade by extracellular matrix remodeling promotes liver metastatic colonization in uveal melanoma

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Wei Dai ◽  
Shenglan Liu ◽  
Shubo Wang ◽  
Li Zhao ◽  
Xiao Yang ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Cancer Cells ◽  
Uveal Melanoma ◽  
Specific Inhibitor ◽  
Type I ◽  
Matrix Remodeling ◽  
Metastatic Colonization ◽  
Tgf Β1

AbstractColonization is believed a rate-limiting step of metastasis cascade. However, its underlying mechanism is not well understood. Uveal melanoma (UM), which is featured with single organ liver metastasis, may provide a simplified model for realizing the complicated colonization process. Because DDR1 was identified to be overexpressed in UM cell lines and specimens, and abundant pathological deposition of extracellular matrix collagen, a type of DDR1 ligand, was noted in the microenvironment of liver in metastatic patients with UM, we postulated the hypothesis that DDR1 and its ligand might ignite the interaction between UM cells and their surrounding niche of liver thereby conferring strengthened survival, proliferation, stemness and eventually promoting metastatic colonization in liver. We tested this hypothesis and found that DDR1 promoted these malignant cellular phenotypes and facilitated metastatic colonization of UM in liver. Mechanistically, UM cells secreted TGF-β1 which induced quiescent hepatic stellate cells (qHSCs) into activated HSCs (aHSCs) which secreted collagen type I. Such a remodeling of extracellular matrix, in turn, activated DDR1, strengthening survival through upregulating STAT3-dependent Mcl-1 expression, enhancing stemness via upregulating STAT3-dependent SOX2, and promoting clonogenicity in cancer cells. Targeting DDR1 by using 7rh, a specific inhibitor, repressed proliferation and survival in vitro and in vivo outgrowth. More importantly, targeting cancer cells by pharmacological inactivation of DDR1 or targeting microenvironmental TGF-β1-collagen I loop exhibited a prominent anti-metastasis effect in mice. In conclusion, targeting DDR1 signaling and TGF-β signaling may be a novel approach to diminish hepatic metastasis in UM.

The extracellular matrix of hybrids between melanoma cells and normal fibroblasts

1988 ◽  
Vol 91 (2) ◽  
pp. 281-286
Author(s):  
M.C. Copeman ◽  
H. Harris
Keyword(s):  
Extracellular Matrix ◽  
Protease Activity ◽  
Malignant Tumour ◽  
Melanoma Cells ◽  
Chromosome Loss ◽  
Type I ◽  
Chromosome 4 ◽  
Hybrid Cells

It has been shown that when malignant tumour cells are fused with normal fibroblasts the suppression of malignancy in the hybrids is linked to their ability to produce a collagenous extracellular matrix in vivo. When, as a consequence of chromosome loss, segregants arise that reacquire malignancy, these do not produce any detectable matrix. In this paper we examine the main components of the extracellular matrix produced in vitro by hybrids between malignant mouse melanoma cells and normal mouse fibroblasts. Hybrids in which malignancy is suppressed synthesize about ten times as much type 1 procollagen as the malignant segregants derived from them; they also retain more fibronectin in the cell layer and release less protease activity into the medium. Malignant segregants more closely resemble the parental melanoma cells in producing fibronectin and mainly types IV and V procollagen. When hybrid cells in which malignancy is initially suppressed are grown continuously in vitro, the production of type I procollagen declines, and the production of type V procollagen and the release of protease activity into the medium increase. These changes, which are associated with the loss from the hybrid cells of both copies of the chromosome 4 derived from the parental fibroblast, predict the reacquisition of malignancy when the cells are inoculated into mice. It is possible that one gene or set of genes located on chromosome 4 determines both the execution of the fibroblast differentiation programme and the suppression of malignancy.

Dynamic extracellular matrix stiffening induces a phenotypic transformation and a migratory shift in epithelial cells

2020 ◽  
Vol 12 (6) ◽  
pp. 161-174
Author(s):  
Shane C Allen ◽  
Jessica A Widman ◽  
Anisha Datta ◽  
Laura J Suggs
Keyword(s):  
Extracellular Matrix ◽  
Epithelial Cells ◽  
Epithelial To Mesenchymal Transition ◽  
Soft Tissue Tumors ◽  
Tumor Formation ◽  
Matrix Stiffness ◽  
Mesenchymal Transition ◽  
Cell Clusters

Abstract Soft tissue tumors, including breast cancer, become stiffer throughout disease progression. This increase in stiffness has been shown to correlate to malignant phenotype and epithelial-to-mesenchymal transition (EMT) in vitro. Unlike current models, utilizing static increases in matrix stiffness, our group has previously created a system that allows for dynamic stiffening of an alginate–matrigel composite hydrogel to mirror the native dynamic process. Here, we utilize this system to evaluate the role of matrix stiffness on EMT and metastasis both in vitro and in vivo. Epithelial cells were seen to lose normal morphology and become protrusive and migratory after stiffening. This shift corresponded to a loss of epithelial markers and gain of mesenchymal markers in both the cell clusters and migrated cells. Furthermore, stiffening in a murine model reduced tumor burden and increased migratory behavior prior to tumor formation. Inhibition of FAK and PI3K in vitro abrogated the morphologic and migratory transformation of epithelial cell clusters. This work demonstrates the key role extracellular matrix stiffening has in tumor progression through integrin signaling and, in particular, its ability to drive EMT-related changes and metastasis.

scholarly journals Hypersensitivity Reactions to Monoclonal Antibodies in Children

Medicina ◽  
2020 ◽  
Vol 56 (5) ◽  
pp. 232
Author(s):  
Francesca Mori ◽  
Francesca Saretta ◽  
Annamaria Bianchi ◽  
Giuseppe Crisafulli ◽  
Silvia Caimmi ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Therapeutic Option ◽  
Provocation Test ◽  
Type I ◽  
Hypersensitivity Reactions ◽  
Biologic Drugs ◽  
Type Iv ◽  
Drug Provocation Test

Biologic drugs are widely used in pediatric medicine. Monoclonal antibodies (mAbs) in particular are a therapeutic option for rheumatic, autoinflammatory and oncologic diseases. Adverse drug reactions and hypersensitivity reactions (HSR) to mAbs may occur in children. Clinical presentation of HSRs to mAbs can be classified according to phenotypes in infusion-related reactions, cytokine release syndrome, both alpha type reactions and type I (IgE/non-IgE), type III, and type IV reactions, all beta-type reactions. The aim of this review is to focus on HSRs associated with the most frequent mAbs in childhood, with particular attention to beta-type reactions. When a reaction to mAbs is suspected a diagnostic work-up including in-vivo and in-vitro testing should be performed. A drug provocation test is recommended only when no alternative drugs are available. In selected patients with immediate IgE-mediated drug allergy a desensitization protocol is indicated. Despite the heavy use of mAbs in childhood, studies evaluating the reliability of diagnostic test are lacking. Although desensitization may be effective in reducing the risk of reactions in children, standardized pediatric protocols are still not available.

scholarly journals Airway Epithelial Cell Migration Dynamics: MMP-9 Role in Cell–Extracellular Matrix Remodeling

1999 ◽  
Vol 146 (2) ◽  
pp. 517-529 ◽  
Author(s):  
Claire Legrand ◽  
Christine Gilles ◽  
Jean-Marie Zahm ◽  
Myriam Polette ◽  
Anne-Cécile Buisson ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Cell Migration ◽  
Leading Edge ◽  
Collagen Iv ◽  
Matrix Remodeling ◽  
Airway Epithelial ◽  
Type Iv ◽  
Migration Dynamics

Cell spreading and migration associated with the expression of the 92-kD gelatinase (matrix metalloproteinase 9 or MMP-9) are important mechanisms involved in the repair of the respiratory epithelium. We investigated the location of MMP-9 and its potential role in migrating human bronchial epithelial cells (HBEC). In vivo and in vitro, MMP-9 accumulated in migrating HBEC located at the leading edge of a wound and MMP-9 expression paralleled cell migration speed. MMP-9 accumulated through an actin-dependent pathway in the advancing lamellipodia of migrating cells and was subsequently found active in the extracellular matrix (ECM). Lamellipodia became anchored through primordial contacts established with type IV collagen. MMP-9 became amassed behind collagen IV where there were fewer cell–ECM contacts. Both collagen IV and MMP-9 were involved in cell migration because when cell–collagen IV interaction was blocked, cells spread slightly but did not migrate; and when MMP-9 activation was prevented, cells remained fixed on primordial contacts and did not advance at all. These observations suggest that MMP-9 controls the migration of repairing HBEC by remodeling the provisional ECM implicated in primordial contacts.

scholarly journals Cells that emerge from embryonic explants produce fibers of type IV collagen.

1985 ◽  
Vol 101 (4) ◽  
pp. 1175-1181 ◽  
Author(s):  
J M Chen ◽  
C D Little
Keyword(s):  
Extracellular Matrix ◽  
Epithelial Cells ◽  
Basement Membrane ◽  
Type Iv Collagen ◽  
Polyclonal Antibodies ◽  
Mouse Lung ◽  
Embryonic Mouse ◽  
Type Iv ◽  
Collagen Substratum

Double immunofluorescence staining experiments designed to examine the synthesis and deposition of collagen types I and IV in cultured explants of embryonic mouse lung revealed the presence of connective tissue-like fibers that were immunoreactive with anti-type IV collagen antibodies. This observation is contrary to the widely accepted belief that type IV collagen is found only in sheet-like arrangements beneath epithelia or as a sheath-like layer enveloping bundles of nerve or muscle cells. The extracellular matrix produced by cells that migrate from embryonic mouse lung rudiments in vitro was examined by double indirect immunofluorescence microscopy. Affinity-purified monospecific polyclonal antibodies were used to examine cells after growth on glass or native collagen substrata. The data show that embryonic mesenchymal cells can produce organized fibers of type IV collagen that are not contained within a basement membrane, and that embryonic epithelial cells deposit fibers and strands of type IV collagen beneath their basal surface when grown on glass; however, when grown on a rat tail collagen substratum the epithelial cells produce a fine meshwork. To our knowledge this work represents the first report that type IV collagen can be organized by cells into a fibrous extracellular matrix that is not a basement membrane.

scholarly journals Fibroblasts promote the formation of a continuous basal lamina during myogenesis in vitro.

1986 ◽  
Vol 102 (3) ◽  
pp. 740-747 ◽  
Author(s):  
R D Sanderson ◽  
J M Fitch ◽  
T R Linsenmayer ◽  
R Mayne
Keyword(s):  
Basal Lamina ◽  
Collagen Gel ◽  
Muscle Cells ◽  
Immunofluorescent Staining ◽  
Electron Microscopic ◽  
Type Iv ◽  
Membrane Components ◽  
Rat Tail

Analyses were made of the requirements for the formation of a continuous basal lamina during myogenesis of quail muscle in vitro. A culture system was developed in which mass cultures of differentiating muscle cells were embedded in a native gel of rat tail collagen. Fibroblastic cells, which were also present in the cultures, migrated into the gel and within a few days surrounded the newly formed myotubes. In this environment, a continuous basal lamina was formed at the surface of the myotubes as demonstrated by immunofluorescent staining with monoclonal antibodies against type IV collagen, laminin, and heparan sulfate, as well as by electron microscopic immunolocalization. To distinguish between the role of the fibroblasts and the collagen gel in promoting basal lamina formation, clones of quail muscle cells lacking fibroblasts were subsequently embedded in a native rat tail collagen gel. Under these conditions, only very limited fluorescent staining for basement membrane components was observed associated with the myotubes. However, the introduction of chick muscle or skin fibroblasts into the clonal cultures just before gel formation resulted in the formation of an extensive basal lamina on the surface of the myotubes. Conditioned medium from fibroblast cultures by itself was not effective in promoting basal lamina formation. These results clearly show that during myogenesis in vitro fibroblasts must be in close proximity to the myotubes for a continuous basal lamina to form. These results probably relate closely to the interactions that must occur during myogenesis in vivo between the muscle cells and the surrounding connective tissue including the developing tendons.

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