scholarly journals Biochemical and ultrastructural studies of proteoheparan sulfates synthesized by PYS-2, a basement membrane-producing cell line.

1982 ◽  
Vol 92 (2) ◽  
pp. 357-367 ◽  
Author(s):  
A Oohira ◽  
T N Wight ◽  
J McPherson ◽  
P Bornstein

The mouse teratocarcinoma-derived cell line, PYS-2, has been shown to produce laminin, a basement membrane-specific glycoprotein. In these studies we demonstrate that PYS-2 cells synthesize and secrete into the culture medium a proteoglycan which contains only heparan sulfate as its sulfated polysaccharide side chains, as well as type IV procollagen and laminin. The apparent molecular weights of the proteoglycan and its heparan sulfate side chain were estimated to be 400,000 and 25,000, respectively, by gel chromatography. A proteoheparan sulfate with properties closely similar, if not identical, to those of the proteoglycan in the medium, together with two heparan sulfate single chains of different molecular size, were extracted from the cell layer with 2% SDS in the presence of protease inhibitors. Ultrastructurally, a fine fibrillar intercellular matrix was recognized which contained discrete 100-200 A diameter ruthenium red-positive granules interspersed throughout the filamentous meshwork. The PYS-2 cultures were shown by immunofluorescence to react with antibodies against the heparan sulfate-containing proteoglycan isolated from the mouse EHS sarcoma (Hassell, J. R., P. G. Robey, H. J. Barrach, J. Wilczek, S. I. Rennard, and G. R. Martin. 1980. Proc. Natl. Acad. Sci. U. S. A. 77:4494-4498). Immunoelectron microscopic examination, using the same antibodies, revealed that the proteoheparan sulfate was located not only at the edges but also within the interstices of the matrix. These findings indicate that PYS-2 cells synthesize and secrete a proteoglycan with properties similar to those of basement membrane proteoglycan. These cells may therefore serve as a useful model system for the study of the biosynthesis and structure of basement membranes.

1983 ◽  
Vol 31 (1) ◽  
pp. 35-45 ◽  
Author(s):  
I Leivo

Teratocarcinoma-derived endodermal PYS-2 cells are known to synthesize an extracellular matrix containing the basement membrane molecules laminin, type IV collagen, and heparan sulfate proteoglycan as major constituents (I. Leivo, K. Alitalo, L. Risteli, A. Vaheri, R. Timpl, J. Wartiovaara, Exp Cell Res 137:15-23, 1982). Immunoferritin techniques with specific antibodies were used in the present study to define the ultrastructural localization of the above constituents in the fibrillar network. Laminin was detected in matrix network adjacent to the basal cell membrane and in protruding matrix fibrils that connect the matrix to the cell membrane. Ruthenium red-stainable heparinase-sensitive 10- to 20-nm particles were often present at the junction of the attachment fibrils and the matrix network, or along the attachment fibrils. A corresponding distribution of ferritin label was observed for basement membrane heparan sulfate proteoglycan. Type IV collagen was found in the matrix network but not in the attachment fibrils. The results suggest that the PYS-2 cells are connected to their pericellular matrix by fibrils containing laminin associated with heparan sulfate-containing particles. These results may also have relevance for the attachment of epithelial cells to basement membranes.


1982 ◽  
Vol 95 (1) ◽  
pp. 340-344 ◽  
Author(s):  
G W Laurie ◽  
C P Leblond ◽  
G R Martin

Electron microscopic immunostaining of rat duodenum and incisor tooth was used to examine the location of four known components of the basement-membrane region: type IV collagen, laminin, heparan sulfate proteoglycan, and fibronectin. Antibodies or antisera against these substances were localized by direct or indirect peroxidase methods on 60-microns thick slices of formaldehyde-fixed tissues. In the basement-membrane region of the duodenal epithelium, enamel-organ epithelium, and blood-vessel endothelium, immunostaining for all four components was observed in the basal lamina (also called lamina densa). The bulk of the lamina lucida (rara) was unstained, but it was traversed by narrow projections of the basal lamina that were immunostained for all four components. In the subbasement-membrane fibrous elements or reticular lamina, immunostaining was confined to occasional "bridges" extending from the epithelial basal-lamina to that of adjacent capillaries. The joint presence of type IV collagen, laminin, heparan sulfate proteoglycan, and fibronectin in the basal lamina indicates that these substances do not occur in separate layers but are integrated into a common structure.


Author(s):  
K. A. Holbrook

The dermal-epidermal junction (DEJ), or basement membrane rone, is the boundary between the epithelial and mesenchymal compartments of the skin; epidermal and fibroblastic cells in these two regions collaborate to synthesire its components. Ultrastructural studies (TEM and SEM) have defined a series of planes or layers (basal epidermal, lamina lucida, lamina densa, sublamina densa) and the morphology and density of attachment structures (hemidesmosomes, anchoring filaments, anchoring fibrils and anchoring plaques) in this region of normal skin. Change in structure of the DEJ provides information about the history of the tissue; reduplication of the lamina densa, for example, indicates a site of cell detachment or migration, or remodelling that accompanies repair of focal damage. In normal skin the structure of the DEJ is stable; in pathologic conditions it can be compromised by the congenital absence of certain structures or antigens (e.g., in the inherited disorders, epidermolysis bullosa [EB]) or by enzymatic degradation (e.g., in tumor invasion). Dissolution of the DEJ can also occur normally during the formation of epidermal appendages (e.g., hair follicles) and as melanocytes and Langerhans cells migrate into the epidermis during development.Biochemical and immunohisto/cytochemical studies have identified more than 20 molecules at the DEJ. These include well known matrix molecules (e.g., types IV and V collagen, laminin and fibronectin) and skin-specific antigens. The latter have been identified by autoantibodies or specific polyclonal or monoclonal antibodies raised against the skin, cultured cells and other epithelia. Some of the molecules of the DEJ are are present in basement membrane zones of many epithelia and thus are considered ubiquitous components (type IV, V, laminin, fibronectin, nidogen, entactin, HSPG, LDA-1, CSP [3B3]). All of them (that have been investigated in developing skin) appear ontogenetically as early as human embryonic tissue can be obtained and their expression is typically normal in patients with EB. The known properties of many of these molecules (particularly the matrix components) suggest functions they might impart to the DEJ: support of an epithelium (type IV collagen), regulation of permeability (heparan sulfate proteoglycan) or facilitation of cell attachment (fibronectin) and movement (laminin). Another group of matrix components and antigens of the DEJ includes molecules that are skin-specific or characteristic of stratified squamous epithelia (type VII collagen=LH 7:2 antigen, bullous pemphigoid antigen, AA3, GB3, KF-1,19-DEJ-1, epidermolysis bullosa acquisita antigen [EBA], AF-1 and AF-2, cicatricial pemphigoid antigen [CPA]) . These molecules are expressed in the DEJ later in development than the first group of molecules, in conjunction with the morphologic appearance of the structure they represent. Their appearance is also coordinated with specific developmental events (e.g., epidermal stratification) and the expression of molecules of differentiation in the epidermis and dermis. One or more of them is typically absent or reduced in expression in the skin of patients with heritable disorders affecting this region. There is no apparent correlation between the location of molecules in the DEJ and the stability of their expression.


2018 ◽  
Vol 39 (04) ◽  
pp. 494-503 ◽  
Author(s):  
Charles Pusey ◽  
Stephen McAdoo

AbstractAntiglomerular basement membrane (anti-GBM) disease is a rare but life-threatening autoimmune vasculitis that is characterized by the development of pathogenic autoantibodies to type IV collagen antigens expressed in the glomerular and alveolar basement membranes. Once deposited in tissue, these autoantibodies incite a local capillaritis which manifests as rapidly progressive glomerulonephritis (GN) in 80 to 90% of patients, and with concurrent alveolar hemorrhage in ∼50%. A small proportion of cases may present with pulmonary disease in isolation. Serological testing for anti-GBM antibodies may facilitate rapid diagnosis, though renal biopsy is often required to confirm the presence of necrotizing or crescentic GN and linear deposition of autoantibody on the glomerular basement membrane. Alveolar hemorrhage may be evident clinically, or detected on imaging, pulmonary function testing, or bronchoscopy. Prompt treatment with plasmapheresis, cyclophosphamide, and steroids is usually indicated to remove pathogenic autoantibodies, to prevent their ongoing production, and to ameliorate end-organ inflammation. Alveolar hemorrhage is usually responsive to this treatment, and long-term respiratory sequelae are uncommon. Renal prognosis is more variable, though with aggressive treatment, independent renal function is maintained at 1 year in more than 80% of patients not requiring renal replacement therapy at presentation. Relapse in uncommon in anti-GBM disease, unless there is a concomitant antineutrophil cytoplasm antibody (present in 30–40%), in which case maintenance immunosuppression is recommended.


1983 ◽  
Vol 97 (3) ◽  
pp. 940-943 ◽  
Author(s):  
J M Fitch ◽  
R Mayne ◽  
T F Linsenmayer

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.


1981 ◽  
Vol 91 (2) ◽  
pp. 427-437 ◽  
Author(s):  
C A Vaccaro ◽  
J S Brody

The ultrastructural characteristics of alveolar (ABM) and capillary (CBM) basement membranes in the adult rat lung have been defined using tannic acid fixation, ruthenium red staining, or incubation in guanidine HCl. ABM is dense and amorphous, has 3- to 5-nm filaments in the lamina rara externa (facing the alveolus) that run between the lamina densa and the basal cell surface of the epithelium, has an orderly array of ruthenium red-positive anionic sites that appear predominantly (79%) on the lamina rara externa, and has discontinuities beneath alveolar type II cells but not type I cells that allow penetration of type II cytoplasmic processes into the interstitium of the alveolar wall. The CBM is fibrillar and less compact than ABM, has no lamina rara filaments, and has one fifth the number of ruthenium red-positive anionic sites of ABM that appear predominantly (64%) overlying the lamina densa. Incubation of lung tissue with Flavobacterium heparinum enzyme or with chondroitinase has shown that ABM anionic sites represent heparan sulfate proteoglycans, whereas CBM anionic sites contain this and other sulfated proteoglycans. The CBM fuses in a local fashion with ABM, compartmentalizing the alveolar wall into a thick and thin side and establishing a thin, single, basement-membrane gas-exchange surface between alveolar air, and capillary blood. The potential implications of ABM and CBM ultrastructure for permeability, cell differentiation, and repair and morphogenesis of the lung are discussed.


1981 ◽  
Author(s):  
L Balleisen ◽  
J Rauterberg ◽  
J Risteli ◽  
H Rohde ◽  
R Timpl

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.


1991 ◽  
Vol 113 (5) ◽  
pp. 1231-1241 ◽  
Author(s):  
C J Soroka ◽  
M G Farquhar

A novel heparan sulfate proteoglycan (HSPG) present in the extracellular matrix of rat liver has been partially characterized. Proteoglycans were purified from a high salt extract of total microsomes from rat liver and found to consist predominantly (approximately 90%) of HSPG. A polyclonal antiserum raised against this fraction specifically recognized HSPG by immunoprecipitation and immunoblotting. The intact, fully glycosylated HSPG migrated as a broad smear (150-300 kD) by SDS-PAGE, but after deglycosylation with trifluoromethanesulfonic acid only a single approximately 40-kD band was seen. By immunocytochemistry this HSPG was localized in the perisinusoidal space of Disse associated with irregular clumps of basement membrane-like extracellular matrix material, some of which was closely associated with the hepatocyte sinusoidal cell surface. It was also localized in biosynthetic compartments (rough ER and Golgi cisternae) of hepatocytes, suggesting that this HSPG is synthesized and deposited in the space of Disse by the hepatocyte. The anti-liver HSPG IgG also stained basement membranes of hepatic blood vessels and bile ducts as well as those of kidney and several other organs (heart, pancreas, and intestine). An antibody that recognizes the basement membrane HSPG found in the rat glomerular basement membrane did not precipitate the 150-300-kD rat liver HSPG. We conclude that the liver sinusoidal space of Disse contains a novel population of HSPG that differs in its overall size, its distribution and in the size of its core protein from other HSPG (i.e., membrane-intercalated HSPG) previously described in rat liver. It also differs in its core protein size from HSPG purified from other extracellular matrix sources. This population of HSPG appears to be a member of the basement membrane HSPG family.


1980 ◽  
Vol 85 (3) ◽  
pp. 735-753 ◽  
Author(s):  
W H Reeves ◽  
Y S Kanwar ◽  
M G Farquhar

Glomerular development was studied in the newborn rat kidney by electron microscopy and cytochemistry. Glomerular structure at different developmental stages was related to the permeability properties of its components and to the differentiation of anionic sites in the glomerular basement membrane (GBM) and on endothelial and epithelia cell surfaces. Cationic probes (cationized ferritin, ruthenium red, colloidal iron) were used to determine the time of appearance and distribution of anionic sites, and digestion with specific enzymes (neuraminidase, heparinase, chondroitinases, hyaluronidases) was used to determine their nature. Native (anionic) ferritin was used to investigate glomerular permeability. The main findings were: (a) The first endothelial fenestrae (which appear before the GBM is fully assembled) possess transient, negatively charged diaphragms that bind cationized ferritin and are impermeable to native ferritin. (b). Two types of glycosaminoglycan particles can be identified by staining with ruthenium red. Large (30-nm) granules are seen only in the cleft of the S-shaped body at the time of mesenchymal migration into the renal vesicle. They consist of hyaluronic acid and possibly also chondroitin sulfate. Smaller (10-15-nm) particles are seen in the earliest endothelial and epithelial basement membranes (S-shaped body stage), become concentrated in the laminae rarae after fusion of these two membranes to form the GBM, and contain heparan sulfate. They are assumed to be precursors of the heparan sulfate-rich granules present in the mature GBM. (c) Distinctive sialic acid-rich, and sialic acid-poor plasmalemmal domains have been delineated on both the epithelial and endothelial cell surfaces. (d) The appearance of sialoglycoproteins on the epithelial cell surface concides with the development of foot processes and filtration slits. (e) Initially the GBM is loosely organized and quite permeable to native ferritin ;it becomes increasinly impermeable to ferritin as the lamina densa becomes more compact. (f) The number of endothelial fenestrae and open epithelial slits increases as the GBM matures and becomes organized into an effective barrier to the passage of native ferritin.


1981 ◽  
Vol 91 (1) ◽  
pp. 1-10 ◽  
Author(s):  
P Ekblom

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.


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