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.

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 Inhibition of laminin self-assembly and interaction with type IV collagen by antibodies to the terminal domain of the long arm.

1986 ◽  
Vol 103 (5) ◽  
pp. 1689-1697 ◽  
Author(s):  
A S Charonis ◽  
E C Tsilibary ◽  
T Saku ◽  
H Furthmayr
Keyword(s):  
Self Assembly ◽  
Binding Sites ◽  
Type Iv Collagen ◽  
Specific Interaction ◽  
Basement Membranes ◽  
Complex Domain ◽  
Peptide Fragment ◽  
Type Iv ◽  
Collagen Molecules

Laminin is a major glycoprotein of the basement membrane. Although its precise localization and orientation within this structure is unknown, it is presumably anchored to other macromolecules such as type IV collagen or proteoheparan sulfate. In vitro, laminin has the ability to self-assemble and to bind to type IV collagen molecules at distinct sites. To identify more precisely the domains of the complex, cross-shaped laminin molecule that are involved in these interactions, images of laminin-laminin dimers and laminin-type IV collagen complexes obtained by the rotary shadowing method were analyzed. We observed that the complex domain at the end of the long arm of laminin is predominantly involved in these interactions. By using Fab fragments of antibodies specific for a peptide fragment derived from this complex domain, it is shown that laminin self-assembly is inhibited in their presence, as measured by turbidity and by electron microscopy. In addition, these antibodies inhibit the specific interaction of laminin with type IV collagen. These data suggest that the complex domain at the end of the long arm of laminin contains binding sites of potential importance for the assembly of basement membranes.

scholarly journals Developmental acquisition of basement membrane heterogeneity: type IV collagen in the avian lens capsule.

1983 ◽  
Vol 97 (3) ◽  
pp. 940-943 ◽  
Author(s):  
J M Fitch ◽  
R Mayne ◽  
T F Linsenmayer
Keyword(s):  
Basement Membrane ◽  
Type Iv Collagen ◽  
Lens Capsule ◽  
Basement Membranes ◽  
Developmentally Regulated ◽  
Membrane Heterogeneity ◽  
Domain Specific ◽  
Type Iv ◽  
Anterior Lens Capsule ◽  
Immunohistochemical Analyses

To investigate potential heterogeneity and developmental changes in basement membranes during embryogenesis, we performed immunohistochemical analyses on lens capsules in chicken embryos of different ages using domain-specific monoclonal antibodies against type IV collagen. We found that the capsule of the newly formed lens stained uniformly with antibodies against this component of basement membranes, but with increasing age and differentiation of the lens cells the anterior lens capsule remained brightly fluorescent while staining of the posterior capsule became relatively much less intense. This antero-posterior gradient of anti-type IV collagen antibody reactivity demonstrated that developmentally-regulated changes can occur within a single, continuous basement membrane.

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.

Platelet Interaction With Basement Membrane Proteins

1981 ◽  
Author(s):  
L Balleisen ◽  
J Rauterberg ◽  
J Risteli ◽  
H Rohde ◽  
R Timpl
Keyword(s):  
Membrane Proteins ◽  
Basement Membrane ◽  
Type Iv Collagen ◽  
Fibrin Clot ◽  
Basement Membranes ◽  
Plastic Substrate ◽  
Acid Extraction ◽  
Clot Retraction ◽  
Type Iv ◽  
Basement Membrane Proteins

Basement membranes consist mainly of two components: non-fibrillar type IV collagen and the non-collagenous glycoprotein laminin (m.w.900.000) which is capable to interact with cell surfaces. The collagenous protein was studied in form of two major fragments comprising together the total mass of the molecule. 7-S collagen which resembles the crosslinking domain of type IV collagen was isolated after collagenase digestion and consisted of four triple helices aligned in a parallel fasion (m.w.360.000). The major triple helical domain of type IV collagen (m.w.450.000) could be obtained by a acid extraction but had lost most of the 7-S domain.Interaction with platelets was examined in aggregation, cell spreading and fibrin clot retraction assays including the determination of malondialdehyde formation. 7-S collagen was the most active component in all three assays. Aggregation was induced by as little as 25 µg/ml and was confirmed by electronmicroscopy. When compared to interstitial collagens, however, 10-20 fold higher amounts of 7-S collagen are required to produce the same effects. Acid extracted type IV collagen possessed virtually no activity. Laminin did not aggregate platelets but promoted strongly their attachment and spreading on a plastic substrate. Thus both basement membrane proteins apparently interact with platelets in different ways via distinct domains of the molecules.

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 Domain and basement membrane specificity of a monoclonal antibody against chicken type IV collagen.

1982 ◽  
Vol 95 (2) ◽  
pp. 641-647 ◽  
Author(s):  
J M Fitch ◽  
E Gibney ◽  
R D Sanderson ◽  
R Mayne ◽  
T F Linsenmayer
Keyword(s):  
Monoclonal Antibody ◽  
Basement Membrane ◽  
Type Iv Collagen ◽  
Helical Structure ◽  
Immunohistochemical Localization ◽  
Basement Membranes ◽  
Optical Rotatory Dispersion ◽  
Collagen Molecule ◽  
Type Iv ◽  
Triple Helical Domain

A monoclonal antibody, IV-IA8, generated against chicken type IV collagen has been characterized and shown to bind specifically to a conformational-dependent site within a major, triple helical domain of the type IV molecule. Immunohistochemical localization of the antigenic determinant with IV-IA8 revealed that the basement membranes of a variety of chick tissues were stained but that the basement membrane of the corneal epithelium showed little, if any, staining. Thus, basement membranes may differ in their content of type IV collagen, or in the way in which it is assembled. The specificity of the antibody was determined by inhibition ELISA using purified collagen types I-V and three purified molecular domains of chick type IV collagen ([F1]2F2, F3, and 7S) as inhibitors. Only unfractionated type IV collagen and the (F1)2F2 domain bound the antibody. Antibody binding was destroyed by thermal denaturation of the collagen, the loss occurring at a temperature similar to that at which previous optical rotatory dispersion studies had shown melting of the triple helical structure of (F1)2F2. Such domain-specific monoclonal antibodies should prove to be useful probes in studies involving immunological dissection of the type IV collagen molecule, its assembly within basement membranes, and changes in its distribution during normal development and in disease.

scholarly journals Immunohistochemical evidence for the intracellular formation of basement membrane collagen (type IV) in developing tissues.

1980 ◽  
Vol 28 (12) ◽  
pp. 1267-1274 ◽  
Author(s):  
G W Laurie ◽  
C P Leblond ◽  
I Cournil ◽  
G R Martin
Keyword(s):  
Basement Membrane ◽  
Type Iv Collagen ◽  
Early Stage ◽  
Basement Membranes ◽  
Incisor Tooth ◽  
Rat Incisor ◽  
Type Iv ◽  
Stage Of Development ◽  
Basement Membrane Collagen ◽  
Membrane Collagen

Antibodies to type IV collagen obtained from the basement membrane of the mouse EHS tumor were incubated with sections of rat incisor teeth and other tissues for immunostaining by direct or indirect methods. In all locations, the immunostaining was pronounced in basement membranes in which it was restricted to the "basal lamina" layer, from which "bridges" often extended to nearby basal laminae. Usually no immunostaining was detectable in the cells associated with the basement membranes. However, examination of the capillaries at the posterior extremity of the rat incisor tooth, where tissues are at an early stage of development, showed immunostaining not only of the basement membrane, but also of the endothelial cells. The staining was localized in rough endoplasmic reticulum cisternae, some Golgi saccules and their peripheral distensions, and structures believed to be secretory granules. These findings suggest that the synthesis of type IV collagen proceeds along the classical secretory pathways through rough endoplasmic reticulum and Golgi apparatus. At the same time, immunostaining was usually lacking in the cells of the capillaries that had migrated about 2 mm away from the posterior end of the incisor tooth and also in the cells of most other tissues examined, even though the associated basal laminae were reactive. It is, therefore, presumed that the production of type IV collagen may be high in cells at an early stage of development and that any later production and turnover of basement membrane collagen can only be minimal.

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 Basement membrane structure in situ: evidence for lateral associations in the type IV collagen network.

1987 ◽  
Vol 105 (6) ◽  
pp. 2559-2568 ◽  
Author(s):  
P D Yurchenco ◽  
G C Ruben
Keyword(s):  
Basement Membrane ◽  
Type Iv Collagen ◽  
Thin Sheet ◽  
Great Part ◽  
Molecular Architecture ◽  
Branch Points ◽  
Collagen Network ◽  
Type Iv

To determine molecular architecture of the type IV collagen network in situ, the human amniotic basement membrane has been studied en face in stereo relief by high resolution unidirectional metal shadow casting aided by antibody decoration and morphometry. The appearance of the intact basement membrane is that of a thin sheet in which there are regions of branching strands. Salt extraction further exposes these strands to reveal an extensive irregular polygonal network that can be specifically decorated with gold-conjugated anti-type IV collagen antibody. At high magnification one sees that the network, which contains integral (9-11 nm net diameter) globular domains, is formed in great part by lateral association of monomolecular filaments to form branching strands of variable but narrow diameters. Branch points are variably spaced apart by an average of 45 nm with 4.4 globular domains per micron of strand length. Monomolecular filaments (1.7-nm net diameter) often appear to twist around each other along the strand axis; we propose that super helix formation is an inherent characteristic of lateral assembly. A previous study (Yurchenco, P. D., and H. Furthmayr. 1984. Biochemistry. 23:1839) presented evidence that purified murine type IV collagen dimers polymerize to form polygonal arrays of laterally as well as end-domain-associated molecules. The architecture of this polymer is similar to the network seen in the amnion, with lateral binding a major contributor to each. Thus, to a first approximation, isolated type IV collagen can reconstitute in vitro the polymeric molecular architecture it assumes in vivo.

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