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 Formation of basement membranes in the embryonic kidney: an immunohistological study

1981 ◽  
Vol 91 (1) ◽  
pp. 1-10 ◽  
Author(s):  
P Ekblom
Keyword(s):  
Extracellular Matrix ◽  
Basement Membrane ◽  
Type Iv Collagen ◽  
Basement Membranes ◽  
Glomerular Endothelial Cell ◽  
Type Iv ◽  
Endothelial Cell Differentiation ◽  
Inductive Interaction ◽  
Immunohistological Study

Specific antibodies to laminin, type IV collagen, basement-membrane proteoglycan, and fibronectin have been used in immunofluorescence microscopy to study the development of basement membranes of the embryonic kidney. Kidney tubules are known to form from the nephrogenic mesenchyme as a result of an inductive tissue interaction. This involves a change in the composition of the extracellular matrix. The undifferentiated mesenchyme expresses in the composition of the extracellular matrix. The undifferentiated mesenchyme expresses fibronectin but no detectable laminin, type IV collagen, or basement-membrane proteoglycan. During the inductive interaction, basement-membrane specific components (laminin, type IV collagen, basement membrane proteoglycan) become detectable in the induced area, whereas fibronectin is lost. While the differentiation to epithelial cells of the kidney requires an inductive interaction, the development of the vasculature seems to involve an ingrowth of cells which throughout development deposits basement-membrane specific components, as well as fibronectin. These cells form the endothelium and possibly also the mesangium of the glomerulus, and contribute to the formation of the glomerular basement membrane. An analysis of differentiation of the kidney mesenchyme in vitro in the absence of circulation supports these conclusions. Because a continuity with vasculature is required for glomerular endothelial cell differentiation, it is possible that these cells are derived from outside vasculature.

scholarly journals Assembly of the exogenous extracellular matrix during basement membrane formation by alveolar epithelial cells in vitro

2000 ◽  
Vol 113 (5) ◽  
pp. 859-868 ◽  
Author(s):  
A. Furuyama ◽  
K. Mochitate
Keyword(s):  
Epithelial Cells ◽  
Basement Membrane ◽  
Type Iv Collagen ◽  
Alveolar Epithelial Cells ◽  
Coarse Mesh ◽  
Lamina Densa ◽  
Alveolar Epithelial ◽  
Type Iv ◽  
Laminin 1

We found that immortalized alveolar type II epithelial cells (SV40-T2 cells) that were cultured on dense fibrillar collagen supplemented with Matrigel gel formed a thin and continuous lamina densa beneath them. Immunohistochemical analysis of laminin-1, type IV collagen, entactin (nidogen) and perlecan in the culture indicated that all these components were integrated into a sheet structure of basement membrane beneath the cells. Analysis of the temporal and spatial distribution of the basement membrane macromolecules revealed that the initial deposits of laminin-1 and entactin were significantly greater in area in the presence of Matrigel. These globular deposits and the coarse mesh of basement membrane macromolecules developed into a flat membranous basement membrane. In the absence of Matrigel, the SV40-T2 cells failed to form a continuous lamina densa, and the deposits stayed in the coarse mesh. The major biotinylated Matrigel components that were integrated into the basement membrane were laminin-1 and entactin. Furthermore, SV40-T2 cells supplemented with exogenous laminin-1 alone as well as laminin-1 contaminated with entactin formed a continuous lamina densa. These results indicate that the laminin-1 and entactin supplied from the Matrigel were incorporated into a basement membrane beneath the SV40-T2 cells, and contributed to the formation of basement membrane. Therefore, we concluded that the alveolar epithelial cells synthesize laminin-1, entactin, type IV collagen, and perlecan, but that they also needed to assemble exogenous laminin-1 into the basement membrane to complete its formation in vitro.

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 Heparanase Localization during Palatogenesis in Mice

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Azumi Hirata ◽  
Kentaro Katayama ◽  
Takehito Tsuji ◽  
Nagato Natsume ◽  
Toshio Sugahara ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Epithelial Cells ◽  
Basement Membrane ◽  
Matrix Metalloproteinase ◽  
Heparan Sulfate ◽  
Type Iv Collagen ◽  
Early Stages ◽  
Type Iv

Palatogenesis is directed by epithelial-mesenchymal interactions and results partly from remodeling of the extracellular matrix (ECM) of the palatal shelves. Here, we assessed heparanase distribution in developing mouse palates. No heparanase was observed in the vertically oriented palatal shelves in early stages of palate formation. As palate formation progressed, the palatal shelves were reorganized and arranged horizontally above the tongue, and heparanase localized to the epithelial cells of these shelves. When the palatal bilateral shelves first made contact, the heparanase localized to epithelial cells at the tips of shelves. Later in fusing palatal shelves, the cells of the medial epithelial seam (MES) were labeled with intense heparanase signal. In contrast, the basement membrane heparan sulfate (HS) was scarcely observed in the palatal shelves in contact. Moreover, perlecan labeling was sparse in the basement membrane of the MES, on which laminin and type IV collagen were observed. Moreover, we assessed the distribution of matrix metalloproteinase- (MMP-) 9, MMP-2, and MMP-3 in developing mouse palates and these MMPs were observed in the MES. Our findings indicated that heparanase was important for palate formation because it mediated degradation of the ECM of palatal shelves. Heparanase may, in concert with other proteases, participate in the regression of the MES.

scholarly journals Plumbagin Alleviates Capillarization of Hepatic Sinusoids In Vitro by Downregulating ET-1, VEGF, LN, and Type IV Collagen

2017 ◽  
Vol 2017 ◽  
pp. 1-12
Author(s):  
Guiyu Li ◽  
Yue Peng ◽  
Tiejian Zhao ◽  
Jiyong Lin ◽  
Xuelin Duan ◽  
...  
Keyword(s):  
Liver Fibrosis ◽  
Basement Membrane ◽  
Molecular Mechanisms ◽  
Type Iv Collagen ◽  
Vascular Endothelial ◽  
Liver Sinusoidal Endothelial Cells ◽  
Collagen Mrna ◽  
Type Iv ◽  
Endothelial Growth Factor

Critical roles for liver sinusoidal endothelial cells (LSECs) in liver fibrosis have been demonstrated, while little is known regarding the underlying molecular mechanisms of drugs delivered to the LSECs. Our previous study revealed that plumbagin plays an antifibrotic role in liver fibrosis. In this study, we investigated whether plumbagin alleviates capillarization of hepatic sinusoids by downregulating endothelin-1 (ET-1), vascular endothelial growth factor (VEGF), laminin (LN), and type IV collagen on leptin-stimulated LSECs. We found that normal LSECs had mostly open fenestrae and no organized basement membrane. Leptin-stimulated LSECs showed the formation of a continuous basement membrane with few open fenestrae, which were the features of capillarization. Expression of ET-1, VEGF, LN, and type IV collagen was enhanced in leptin-stimulated LSECs. Plumbagin was used to treat leptin-stimulated LSECs. The sizes and numbers of open fenestrae were markedly decreased, and no basement membrane production was found after plumbagin administration. Plumbagin decreased the levels of ET-1, VEGF, LN, and type IV collagen in leptin-stimulated LSECs. Plumbagin promoted downregulation of ET-1, VEGF, LN, and type IV collagen mRNA. Altogether, our data reveal that plumbagin reverses capillarization of hepatic sinusoids by downregulation of ET-1, VEGF, LN, and type IV collagen.

scholarly journals Binding of human plasminogen to basement-membrane (type IV) collagen

1992 ◽  
Vol 284 (1) ◽  
pp. 103-108 ◽  
Author(s):  
M S Stack ◽  
T L Moser ◽  
S V Pizzo
Keyword(s):  
Extracellular Matrix ◽  
Basement Membrane ◽  
Type Iv Collagen ◽  
Specific Interaction ◽  
Serine Proteinase ◽  
Type Iv ◽  
Basement Membrane Collagen ◽  
Extracellular Matrix Remodelling ◽  
Membrane Type ◽  
Protein Components

Plasminogen, the zymogen form of the serine proteinase plasmin, has been implicated in numerous physiological and pathological processes involving extracellular-matrix remodelling. We have previously demonstrated that the activation of plasminogen catalysed by tissue plasminogen activator is dramatically stimulated in the presence of basement-membrane-specific type IV collagen [Stack, Gonzalez-Gronow & Pizzo (1990) Biochemistry 29, 4966-4970]. The present paper describes the binding of plasminogen to type IV collagen. Plasminogen binds to both the alpha 1(IV) and alpha 2(IV) chains of basement-membrane collagen, with binding to the alpha 2(IV) chain preferentially inhibited by 6-aminohexanoic acid. This binding is specific and saturable, with Kd,app. values of 11.5 and 12.7 nM for collagen and gelatin respectively. Although collagen also binds to immobilized plasminogen, this interaction is unaffected by 6-aminohexanoic acid. Limited elastase proteolysis of plasminogen generated distinct collagen-binding fragments, which were identified as the kringle 1-3 and kringle 4 domains. No binding of collagen to mini-plasminogen was observed. These studies demonstrate a specific interaction between plasminogen and type IV collagen and provide further evidence for regulation of plasminogen activation by protein components of the extracellular matrix.

scholarly journals Puromycin Aminonucleoside Suppresses Integrin Expression in Cultured Glomerular Epithelial Cells

2001 ◽  
Vol 12 (4) ◽  
pp. 758-766 ◽  
Author(s):  
UMA KRISHNAMURTI ◽  
BING ZHOU ◽  
WEI-WEI FAN ◽  
EFFIE TSILIBARY ◽  
ELIZABETH WAYNER ◽  
...  
Keyword(s):  
Epithelial Cell ◽  
Epithelial Cells ◽  
Basement Membrane ◽  
Glomerular Basement Membrane ◽  
Type Iv Collagen ◽  
Cell Detachment ◽  
Puromycin Aminonucleoside ◽  
Glomerular Epithelial Cell ◽  
Type Iv ◽  
Glomerular Epithelial Cells

Abstract. Puromycin aminonucleoside (PAN)-induced nephrosis is a well-described model of human idiopathic nephrotic syndrome, but the mechanism of PAN's effect is not completely understood. Because PAN injection into rats results in retraction of glomerular epithelial cell foot processes and glomerular epithelial cell detachment, it was hypothesized that PAN might alter the contacts between these cells and the glomerular basement membrane. The major integrin expressed by glomerular epithelial cells is α3β1, which mediates attachment of these cells to extracellular matrix proteins including type IV collagen. T-SV 40 immortalized human glomerular epithelial cells were used to study PAN's effects on α3β1 expression, as well as that of podocalyxin and the slit diaphragm component ZO-1. Glomerular epithelial cells were seeded into plastic flasks and allowed to attach and proliferate for 48 h. The cells were then incubated for another 48 h in media containing 0, 0.5, or 5.0 μg/ml PAN. PAN exposure resulted in dose-dependent decreases in α3 and β1 expression, both at the protein level and at the mRNA level. This was accompanied by a significant decrease in the adhesion of glomerular epithelial cells to type IV collagen. PAN did not affect ZO-1 protein expression. Treatment with PAN increased the expression of podocalyxin at the protein and mRNA levels. Reduced glomerular epithelial cell expression of α3β1 integrins and impaired adhesion to type IV collagen may contribute to the glomerular epithelial cell detachment from glomerular basement membrane seen in the PAN nephrosis model.

scholarly journals Glomerular epithelial cells secrete a glomerular basement membrane-degrading metalloproteinase.

1992 ◽  
Vol 2 (9) ◽  
pp. 1388-1397
Author(s):  
R Johnson ◽  
H Yamabe ◽  
Y P Chen ◽  
C Campbell ◽  
K Gordon ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Basement Membrane ◽  
Glomerular Basement Membrane ◽  
Type Iv Collagen ◽  
Dependent Manner ◽  
Type Iv Collagenase ◽  
Glomerular Diseases ◽  
Major Band ◽  
Type Iv ◽  
Glomerular Epithelial Cells

Cultured rat glomerular epithelial cells (GEC) were examined for their ability to release extracellular matrix-degrading proteinases with [3H]gelatin as substrate. GEC-conditioned media, under serum-free conditions, contained modest amounts of gelatinase activity (1 to 10 U/mg of protein); the activity was maximal at neutral pH, was inhibited by zinc chelators, was not inhibited by tissue inhibitor of metalloproteinase-2, and could not be further activated by trypsin or organomercurials. Gelatin substrate sodium dodecyl sulfate-polyacrylamide gels of GEC-conditioned medium revealed several zones of lysis, with molecular sizes of 150 kd (major band), and 220, 86 to 93, and 52 to 54 kd (minor bands). Northern blot analysis demonstrated that the GEC metalloproteinase(s) were distinct from the 68- to 72-kd type IV collagenase/gelatinase present in mesangial cells or the 92-kd type IV collagenase present in neutrophils. The GEC gelatinolytic activity also degraded insoluble type IV collagen in glomerular basement membrane in a dose-dependent manner. The major metalloproteinase activity responsible for the type IV collagen degradation has a molecular size of 150 kd with a type IV collagen substrate gel. Thus, GEC produce several neutral metalloproteinases, which, by virtue of their substrate specificity, may play an important role in glomerular basement membrane remodeling and in glomerular diseases characterized by alterations in basement membrane permeability.

Macromolecular organization of basement membrane laminin

1991 ◽  
Vol 49 ◽  
pp. 176-177
Author(s):  
Peter D. Yurchenco
Keyword(s):  
Basement Membrane ◽  
Type Iv Collagen ◽  
Embryonal Carcinoma ◽  
Basement Membranes ◽  
Carcinoma Cells ◽  
Structural Studies ◽  
Type Iv ◽  
Polypeptide Chains ◽  
Macromolecular Organization

Laminin isoforms are major structural and cell-interacting components of basement membranes. The most extensively studied isoform of this glycoprotein (800 kDa) is murine EHS laminin which consists of three polypeptide chains (A,B1,B2) disulfide linked to form a flexible four-armed molecule which in turn is often complexed to entactin, a smaller dumbell-shaped sulfated glycoprotein. One of the functions proposed for laminin is selfassembly into a polymer that constitutes a major part of basement membrane architecture. The principal evidence for this hypothesis has derived from biochemical and structural studies of laminin polymerization in vitro. Embryonal carcinoma cells (M1536B3) grown in suspension culture will differentiate into multicellular spherules that produce basement membrane cores rich in laminin/entactin but devoid of type IV collagen, a characteristic of some basement membranes of developing tissues. We now report that these cores share the same structural/biochemical features with reconstituted laminin polymers.

Sign in / Sign up

Export Citation Format

Share Document