Glycosaminoglycan localization and role in maintenance of tissue spaces in the early chick embryo1

Development ◽  
1977 ◽  
Vol 42 (1) ◽  
pp. 195-207
Author(s):  
Marilyn Fisher ◽  
Michael Solursh

Comparison of sections stained with Alcian blue at pH 1·0 or 2·5 demonstrates the distribution of sulfated and non-sulfated glycosaminoglycans in the extracellular matrix of the stage-8 (Hamburger & Hamilton, 1951) chick embryo. Both types of GAG are present in basement membranes throughout the embryo. Treatment of sections with Streptomyces hyaluronidase, reported to be specific for hyaluronic acid, prior to staining with Alcian blue at pH 2·5 reveals that hyaluronate is an important constituent of the extracellular matrix in basement membranes and in intercellular spaces within the mesoderm. Hyaluronate is shown to be the predominant glycosaminoglycan in the matrix of the head mesenchyme. In addition, examination by SEM and light microscopy of embryos after treatment in ovo with hyaluronidase shows that removal of hyaluronate from living embryos results in a dramatic decrease in cell-free spaces and a weakening of the association between mesoderm and ectoderm in the head.

Development ◽  
1979 ◽  
Vol 54 (1) ◽  
pp. 75-98
Author(s):  
Michael Solursh ◽  
Marilyn Fisher ◽  
Stephen Meier ◽  
Carl T. Singley

The development of the sclerotome is considered as a model for the formation of mesenchyme from an epithelium. In early epithelial somites, transmission and scanning electron microscopy indicate considerable ultrastructural similarity between the future sclerotome and dermamyotomal regions. Subsequently, these two regions diverge in their development. In the forming dermamyotome, junctional complexes become more extensive and the cells become elongated, closely applied to each other, and have angular surface contours. In the forming sclerotome, there is an early reduction in apical junctions. The cells elongate, keeping their original polarity, and acquire numerous filopodia which contain punctate junctions at sites of cell-to-cell contact. Associated with cellular extension is an expansion of the intercellular spaces which do not contain any ultrastructurally recognizable material. Evidence for a role of hyaluronic acid in the expansion of the intercellular spaces is presented. As identified by the susceptibility of cetylpyridinium chloride precipitates to Streptomyces hyaluronidase and chromatographic separation of chondroitinase ABC digestion products, as much as 64–68% of the [3H]glucosamine-labeled glycosaminoglycans synthesized by explanted somites is hyaluronic acid. In addition, hyaluronidase-sensitive label is localized in the intercellular spaces of the sclerotome, as demonstrated by autoradiography. When ,Streptomyces hyaluronidase is injected in ovo into living embryos, the sclerotomal mesenchyme differentiates morphologically, but intercellular spaces are drastically reduced. It is hypothesized that the sclerotomal cells produce a hyaluronate-enriched extracellular matrix which is inflated by hydration to mediate the expansion of the sclerotomal mass towards the notochord.


Development ◽  
1986 ◽  
Vol 94 (1) ◽  
pp. 95-112
Author(s):  
Fiona Tuckett ◽  
Gillian M. Morriss-Kay

This paper forms part of our study of the extracellular matrix and its role in the morphogenesis of the brain during the period of neurulation in the rat embryo. Using indirect immunofluorescence with polyclonal antibodies, we present here a descriptive study of the distribution of the matrix glycoproteins fibronectin, laminin and entactin. The observed distribution of the fibronectin matrix implicates it in providing a structural element in several morphologically active sites; in addition our observations support the previously suggested involvement of fibronectin in the migration of neural crest cells. Entactin was present only in the basement membranes in conjunction with laminin which was not itself confined to these regions. Laminin was also identified within the mesenchymal extracellular matrix, and its general distribution confirms the previously documented role of laminin in maintaining epithelial structure and organization. No patterning in the distribution of these three glycoproteins could be correlated with the change in shape of the neural epithelium associated with either tube formation or neuromere morphogenesis.


1980 ◽  
Vol 87 (1) ◽  
pp. 14-22 ◽  
Author(s):  
P Hsieh ◽  
R Segal ◽  
L B Chen

We have used fluorescein isosthiocyanate-conjugated gelatin (FITC-gelatin) (1 mg/ml) to localize cell surface fibronectin in unfixed live cells in cultures. FITC-gelatin stains the fibronectin matrix on primary cultures of rat and chick embryo fibroblasts as well as untransformed, established cell lines. In live cultured cells, fibronectin in many areas of the extracellular matrix is inaccessible to antibody and cannot be visualized by immunofluorescence staining. In contrast, fibronectin in these areas is fully stainable by FITC-gelatin. At a low concentration (20 micrograms/ml), FITC-gelatin stains the fibronectin matrix of primary cultured cells but not of "untransformed" established cell lines. SEM can detect only the matrix stainable with the low concentration of FITC-gelatin, such as that expressed by primary chick embryo fibroblasts. The binding of fibronectin to the extracellular matrix is very stable and FITC-gelatin remained bound to the matrix for at least 10 d in culture. Radioiodinated gelatin has been used to quantitate the level of cell surface fibronectin in living normal and transformed cells. FITC-gelatin appears to be a useful probe for studying the fibronectin of living cells in culture.


1988 ◽  
Vol 107 (6) ◽  
pp. 2757-2767 ◽  
Author(s):  
E J Mackie ◽  
W Halfter ◽  
D Liverani

The distribution of the extracellular matrix glycoprotein, tenascin, in normal skin and healing skin wounds in rats, has been investigated by immunohistochemistry. In normal skin, tenascin was sparsely distributed, predominantly in association with basement membranes. In wounds, there was a marked increase in the expression of tenascin at the wound edge in all levels of the skin. There was also particularly strong tenascin staining at the dermal-epidermal junction beneath migrating, proliferating epidermis. Tenascin was present throughout the matrix of the granulation tissue, which filled full-thickness wounds, but was not detectable in the scar after wound contraction was complete. The distribution of tenascin was spatially and temporally different from that of fibronectin, and tenascin appeared before laminin beneath migrating epidermis. Tenascin was not entirely codistributed with myofibroblasts, the contractile wound fibroblasts. In EM studies of wounds, tenascin was localized in the basal lamina at the dermal-epidermal junction, as well as in the extracellular matrix of the adjacent dermal stroma, where it was either distributed homogeneously or bound to the surface of collagen fibers. In cultured skin explants, in which epidermis migrated over the cut edge of the dermis, tenascin, but not fibronectin, appeared in the dermis underlying the migrating epithelium. This demonstrates that migrating, proliferating epidermis induces the production of tenascin. The results presented here suggest that tenascin is important in wound healing and is subject to quite different regulatory mechanisms than is fibronectin.


Development ◽  
1983 ◽  
Vol 73 (1) ◽  
pp. 1-15
Author(s):  
Gary C. Schoenwolf ◽  
Marilyn Fisher

Chick embryos at stages 8 to 9 were treated in ovo with Streptomyces hyaluronidase (SH) to determine whether neurulation occurs normally in embryos depleted of hyaluronic acid, a major component of the extracellular matrix. Open neural tube defects occurred in 60–94 % (depending on the particular enzyme batch) of the embryos treated with SH and examined after an additional 24 h of incubation. Defects were confined mainly to the spinal cord. The neural folds underwent elevation in defective regions but failed to converge and fuse across the dorsal midline. The extracellular matrix of embryos treated with SH was depleted consistently, as determined with sections stained with Alcian blue. Control experiments were done to ensure that neural tube defects were not caused by non-specific protease contamination of SH, or by digestion products of hyaluronic acid. We propose several plausible and testable mechanisms through which the extracellular matrix might influence the complex developmental process of neurulation.


1997 ◽  
Vol 3 (S2) ◽  
pp. 179-180
Author(s):  
M. González-Santander Martinez ◽  
M. Monteagudo de la Rosa ◽  
G. Martinez Cuadrado ◽  
R. González Santander

Somite disintegration begins with the disruption and dispersion of cells in its ventromedial region, that upon detaching from the somite form a defined group of cells called “sclerotome”. The sclerotome is formed by scleroblasts that originate paraxial segments. Scleroblasts disperse and migrate forming the “sclerotomal mesenchyma”. This sclerotomal mesenchyma, in its evolution and cell differentiation, will give rise to skeletal tissues. One of the first features of the scleroblast is the production of extracellular matrix rich in hialuronic acid that facilitates the spreading of filopodia and the migration of the sclerotome. Sclerotome development is closely associated to the microenvironment created by the extracellular matrix in which scleroblasts are located. Hialuronic acid is found in the ample intercellular spaces occupied by the hydrated matrix.White Leghorn chick embryos at H.H. stages 9 to 12 were fixed in 2.5% glutaraldehyde, postfixed in 1 % osmium tetroxide and embedded in araldite. Semithin transversal sections were stained with toluidine blue and visualized under the light microscope to locate the sclerotome.


1991 ◽  
Vol 99 (2) ◽  
pp. 443-451
Author(s):  
M.R. Austria ◽  
J.R. Couchman

Basement membranes are complex extracellular matrices contributing to the regulation of growth, migration and differentiation of many cell types. However, little is known about the mechanisms regulating the deposition and assembly of basement membrane from its constituents. We have investigated the role of extracellular matrix molecules in the control of basement membrane matrix assembly by cultured endodermal (PFHR-9) cells. In the presence of fibronectin-depleted serum, substrata of fibronectin or laminin induced an increase in deposition of laminin, type IV collagen and proteoglycans by PFHR-9 cells, in comparison to cells adherent to type I collagen-coated, vitronectin-coated or uncoated substrata. Direct effects of fibronectin or laminin on the degree of cell spreading or rate of proliferation were not responsible for enhanced matrix deposition. The effect did not result from a redirection of basement membrane components to the matrix, since there was no decrease in matrix constituents released to the culture supernatants. Furthermore, the synthesis and release of other molecules that are not basement membrane constituents was unaltered in response to different extracellular matrix substrata. Experiments with fibronectin fragments showed that a 105 × 10(3) Mr ‘cell’-binding domain (containing the cell attachment sequence Arg-Gly-Asp-Ser) was an important contributor to enhanced matrix deposition, while the N-terminal 29 × 10(3) Mr heparin-binding domain also contributed to the effect, particularly with respect to heparan sulfate proteoglycan deposition. It seems that fibronectin has a dual role of action in promoting basement membrane matrix assembly, through direct cell surface interactions, and through the binding of fibronectin to other matrix components that may nucleate or stabilize the matrix assembly.


2019 ◽  
Vol 47 (5) ◽  
pp. 1543-1555 ◽  
Author(s):  
Maurizio Mongiat ◽  
Simone Buraschi ◽  
Eva Andreuzzi ◽  
Thomas Neill ◽  
Renato V. Iozzo

Abstract The extracellular matrix is a network of secreted macromolecules that provides a harmonious meshwork for the growth and homeostatic development of organisms. It conveys multiple signaling cascades affecting specific surface receptors that impact cell behavior. During cancer growth, this bioactive meshwork is remodeled and enriched in newly formed blood vessels, which provide nutrients and oxygen to the growing tumor cells. Remodeling of the tumor microenvironment leads to the formation of bioactive fragments that may have a distinct function from their parent molecules, and the balance among these factors directly influence cell viability and metastatic progression. Indeed, the matrix acts as a gatekeeper by regulating the access of cancer cells to nutrients. Here, we will critically evaluate the role of selected matrix constituents in regulating tumor angiogenesis and provide up-to-date information concerning their primary mechanisms of action.


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