Structure, compositon and function of the dermal-epidermal junction: Relevance in cutaneous disease and diagnosis

1989 ◽  
Vol 47 ◽  
pp. 868-869
Author(s):  
K. A. Holbrook
Keyword(s):  
Basement Membrane ◽  
Epidermolysis Bullosa ◽  
Normal Skin ◽  
Lamina Densa ◽  
Inherited Disorders ◽  
Ultrastructural Studies ◽  
Type Iv ◽  
Type Vii Collagen ◽  
Attachment Structures ◽  
Matrix Components

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.

scholarly journals Type VII collagen forms an extended network of anchoring fibrils.

1987 ◽  
Vol 104 (3) ◽  
pp. 611-621 ◽  
Author(s):  
D R Keene ◽  
L Y Sakai ◽  
G P Lunstrum ◽  
N P Morris ◽  
R E Burgeson
Keyword(s):  
Type Iv Collagen ◽  
Polyclonal Antibodies ◽  
Basement Membrane Zone ◽  
Lamina Densa ◽  
Type Iv ◽  
Type Vii Collagen ◽  
Major Structural Component ◽  
Stromal Matrix ◽  
Matrix Components ◽  
Carboxyl Terminal

Type VII collagen is one of the newly identified members of the collagen family. A variety of evidence, including ultrastructural immunolocalization, has previously shown that type VII collagen is a major structural component of anchoring fibrils, found immediately beneath the lamina densa of many epithelia. In the present study, ultrastructural immunolocalization with monoclonal and monospecific polyclonal antibodies to type VII collagen and with a monoclonal antibody to type IV collagen indicates that amorphous electron-dense structures which we term "anchoring plaques" are normal features of the basement membrane zone of skin and cornea. These plaques contain type IV collagen and the carboxyl-terminal domain of type VII collagen. Banded anchoring fibrils extend from both the lamina densa and from these plaques, and can be seen bridging the plaques with the lamina densa and with other anchoring plaques. These observations lead to the postulation of a multilayered network of anchoring fibrils and anchoring plaques which underlies the basal lamina of several anchoring fibril-containing tissues. This extended network is capable of entrapping a large number of banded collagen fibers, microfibrils, and other stromal matrix components. These observations support the hypothesis that anchoring fibrils provide additional adhesion of the lamina densa to its underlying stroma.

scholarly journals Kalinin: an epithelium-specific basement membrane adhesion molecule that is a component of anchoring filaments.

1991 ◽  
Vol 114 (3) ◽  
pp. 567-576 ◽  
Author(s):  
P Rousselle ◽  
G P Lunstrum ◽  
D R Keene ◽  
R E Burgeson
Keyword(s):  
Basement Membrane ◽  
Disulfide Bonds ◽  
Human Keratinocytes ◽  
Abundant Species ◽  
Lamina Densa ◽  
Basal Surface ◽  
Type Vii Collagen ◽  
Tissue Region ◽  
Long Rod ◽  
Membrane Adhesion

Basal keratinocytes attach to the underlying dermal stroma through an ultrastructurally unique and complex basement membrane zone. Electron-dense plaques along the basal surface plasma membrane, termed hemidesmosomes, appear to attach directly to the lamina densa of the basement membrane through fine strands, called anchoring filaments. The lamina densa is secured to the stroma through a complex of type VII collagen containing anchoring fibrils and anchoring plaques. We have identified what we believe is a novel antigen unique to this tissue region. The mAbs to this antigen localize to the anchoring filaments, just below the basal-dense plate of the hemidesmosomes. In cell culture, the antigen is deposited upon the culture substate by growing and migrating human keratinocytes. Addition of mAb to the cultures causes the cells to round and detach, but does not impair them metabolically. Skin fragments incubated with antibody extensively de-epithelialize. These findings strongly suggest that this antigen is intimately involved in attachment of keratinocytes to the basement membrane. This antigen was isolated from keratinocyte cultures by immunoaffinity chromatography. Two molecules are observed. The most intact species contains three nonidentical chains, 165, 155, and 140 kD linked by interchain disulfide bonds. The second and more abundant species contains the 165- and 140-kD chains, but the 155-kD chain has been proteolytically cleaved to 105 kD. Likewise, two rotary-shadowed images are observed. The larger of the two, presumably corresponding to the most intact form, appears as an asymmetric 107-nm-long rod, with a single globule at one end and two smaller globules at the other. The more abundant species, presumably the proteolytically cleaved form, lacks the distal small globule. We propose the name "kalinin" for this new molecule.

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
Keyword(s):  
Basement Membrane ◽  
Heparan Sulfate ◽  
Cell Line ◽  
Molecular Size ◽  
Sulfated Polysaccharide ◽  
Ruthenium Red ◽  
Basement Membranes ◽  
Gel Chromatography ◽  
Ultrastructural Studies ◽  
Type Iv

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.

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 Possible continuity of subplasmalemmal cytoplasmic network with basement membrane cord network: ultrastructural study

1995 ◽  
Vol 108 (5) ◽  
pp. 1971-1976
Author(s):  
S. Inoue
Keyword(s):  
Basement Membrane ◽  
Type Iv Collagen ◽  
Freeze Substitution ◽  
High Resolution Electron Microscopy ◽  
Sulfate Proteoglycan ◽  
Glutaraldehyde Fixation ◽  
Lamina Densa ◽  
Type Iv ◽  
Resolution Electron ◽  
Visceral Epithelium

The ultrastructure of the subplasmalemmal cytoplasm of the cell and the associated basement membrane as well as the area of the cell-basement membrane border were observed with high resolution electron microscopy after preparation of the tissues with cryofixation or glutaraldehyde fixation followed by freeze substitution. The subplasmalemmal cytoplasm of the smooth muscle cells of rat epididymal tubules and the podocyte processes of the mouse glomerular visceral epithelium were found to be composed of a fine network of irregular anastomosing strands. This network closely resembled the previously characterized cord network of the basement membrane. The cords are known to be composed of a 1.5 to 3 nm thick core filament made up of type IV collagen which is surrounded by an irregular ‘sheath’ of other components. The strands in the subplasmalemmal network showed ultrastructural features similar to those of the cord network. Ribbon-like, 4.5 nm wide heparan sulfate proteoglycan ‘double tracks’ were previously reported to be associated with the cord network. Structures similar in size and appearance to the double tracks were also found in the subplasmalemmal network. At the cell-basement membrane border, the lamina densa of the basement membrane was in contact with the cell without the intervening space of a lamina lucida which was recently found to be an artefact caused by conventional tissue processing. Furthermore, the subplasmalemmal network appeared to be continuous through the plasma membrane, with the cord network of the basement membrane.(ABSTRACT TRUNCATED AT 250 WORDS)

Real-Time PCR Quantification of Protein Expression in Skin Equivalent Monoculture and Coculture Model

2006 ◽  
Vol 15-17 ◽  
pp. 95-100 ◽  
Author(s):  
Tzu Wei Wang ◽  
Hsi Chin Wu ◽  
Jui Sheng Sun ◽  
Feng Huei Lin
Keyword(s):  
Basement Membrane ◽  
Real Time ◽  
Real Time Pcr ◽  
Dermal Fibroblasts ◽  
Collagen Type Iv ◽  
Laminin 5 ◽  
Type Iv ◽  
Type Vii Collagen ◽  
Coculture Model

Three-dimensional gelatin-chondroitin 6 sulphate-hyanuronic acid biomatrix was used as the scaffold to investigate the phenotypic and molecular expression in human keratinocytes (K) and dermal fibroblasts (FB) in three different culture conditions in vitro. The cells were cultured in either monolayer (K or FB only) or coculture (K&FB) model. The deposition of basement membrane proteins secreted by these two kinds of cells was quantitatively characterized by real-time PCR. In the results, dermal fibroblasts were shown to synthesize and deposit laminin 5, type IV and type VII collagen, whereas keratinocytes produced integrin alpha 6 and beta 4 as well as laminin 5 and collagen type IV, VII. Interestingly, the integrin beta 4 subunit was not expressed either in keratinocytes or dermal fibroblasts monoculture but was seen in organotypic coculture model in the early culture period. Furthermore, we found that the expression of those marker compounds was reciprocally regulated when keratinocytes and dermal fibroblasts were cultured together. These results indicated that keratinocyes and dermal fibroblasts worked together to reconstruct dermal-epidermal basement membrane (BM) zone. In brief, our data provide the first time in directly quantifying the expression of BM proteins by using real-time PCR, and also demonstrate that BM proteins were regulated by cell-cell interaction.

scholarly journals Basement membrane components in healing rabbit corneal epithelial wounds: immunofluorescence and ultrastructural studies.

1984 ◽  
Vol 98 (1) ◽  
pp. 128-138 ◽  
Author(s):  
L S Fujikawa ◽  
C S Foster ◽  
I K Gipson ◽  
R B Colvin
Keyword(s):  
Wound Healing ◽  
Basement Membrane ◽  
Corneal Epithelium ◽  
Type Iv Collagen ◽  
Normal Component ◽  
Conjunctival Epithelium ◽  
Epithelial Migration ◽  
Ultrastructural Studies ◽  
Type Iv ◽  
Essential Components

The nature of the substrate that supports epithelial migration in vivo is of interest, particularly with respect to mechanisms of wound healing. Immunofluorescence and electron microscopy were used to search for common substrate components in prototype rabbit corneal wounds: epithelial scrape wounds, in which the corneal or conjunctival epithelium migrated over the denuded lamina densa of the corneal basement membrane (CBM), and superficial keratectomy, in which the corneal epithelium migrated over a bare stroma without CBM. The corneal epithelium moved rapidly over the CBM or stroma to cover the defect within 2-3 d, whereas the conjunctival epithelium required 1-2 wk. In all wounds, fibronectin and fibrin/fibrinogen were deposited onto the bare surface within 8 h after wounding and persisted under the migrating epithelium until migration was complete. Bullous pemphigoid antigen (BPA), a normal component of the CBM, was removed with the epithelium upon scrape wounding and reappeared in the CBM after migration was completed. In contrast, the conjunctival epithelium had a continuous subepithelial band of BPA out to the migrating tip. Laminin, also a normal component of the CBM, was not removed in the scrape wounds, indicating that the region of least resistance to shear stress was between the BPA and laminin layers. Laminin was removed by superficial keratectomy and was not detectable under the leading edge of the migrating cells. Laminin and BPA were restored in the CBM by 2-4 wk. Type IV collagen could not be detected in normal CBM, but was conspicuously present in conjunctival basement membrane and in blood vessels. Focal bands of type IV collagen did appear in the newly synthesized CBM 2-4 wk after keratectomy. These results argue that BPA, laminin, and type IV collagen are not essential for the migration of corneal epithelium during wound healing and support the hypothesis that fibronectin and fibrin/fibrinogen are the common, perhaps the essential, components of the provisional matrix that serves as a substrate until the permanent attachment components are regenerated.

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