Basement Membranes in Skin Are Differently Affected by Lack of Nidogen 1 and 2 (original) (raw)
Related papers
Lack of Nidogen-1 and -2 Prevents Basement Membrane Assembly in Skin-Organotypic Coculture
Journal of Investigative Dermatology, 2007
Nidogens are considered as classical linkers joining laminin and collagen IV networks in basement membranes (BMs); however, recent genetic approaches have suggested that nidogens function in a tissue-specific and developmental context. Thus, in mice lacking both nidogen-1 and-2 heart and lung were severely affected, causing neonatal death. Furthermore, in various locations, extravasation of erythrocytes was observed implying microvascular defects. Mice expressing solely either isoform, had a functional BM, although nidogen-2 binds with lower affinity to the laminin g1 chain. Having previously blocked BM formation by interfering with nidogen-1 binding to laminin in skin-organotypic cocultures, here we investigated the roles of nidogen-1 and-2 in this model. For that purpose, human HaCaT cells were grown in three-dimensional cocultures on collagen matrices containing murine fibroblasts of varying nidogen deficiency. As with our experiments blocking laminin-nidogen interaction, lack of both nidogens completely prevented BM deposition and ultrastructural assembly of BM and hemidesmosomes, although other BM proteins remained detectable at comparable levels with no signs of degradation. Supplementation by recombinant nidogen-1 or-2 restored these structures, as shown by immunofluorescence and electron microscopy, confirming that in this system nidogen-2 is equivalent to nidogen-1, and both can promote the development of a functional BM zone.
Experimental Cell Research, 2002
Organ culture and gene targeting approaches suggest that a high-affinity nidogen-binding site of the laminin ␥1 chain (␥1III4) is important for kidney development and for nerve guidance. Other proteins may also bind ␥1III4, although human nidogen-2 binds poorly to the mouse laminin ␥1 chain. We therefore characterized recombinant mouse nidogen-2 and its binding to basement membrane proteins and cells. Mouse nidogen-1 and -2 interacted at comparable levels with collagen IV, perlecan, and fibulin-2 and, most notably, also with laminin-1 fragments P1 and ␥1III3-5, which both contain the ␥1III4 module. In embryos, nidogen-2 mRNA was produced by mesenchyme at sites of epithelialmesenchymal interactions, but the protein was deposited on epithelial basement membranes, as previously shown for nidogen-1. Hence, binding of both nidogens to the epithelial laminin ␥1 chain is dependent on epithelial-mesenchymal interactions. Epidermal growth factor stimulated expression of both nidogens in embryonic submandibular glands. Both nidogens were found in all studied embryonic and adult basement membranes. Nidogen-2 was more adhesive than nidogen-1 for some cell lines and was mainly mediated by ␣31 and ␣61 integrins as shown by antibody inhibition. These findings revealed extensive coregulation of nidogen-1 and -2 expression and much more complementary functions of the two nidogens than previously recognized. © 2002 Elsevier Science (USA)
Binding of nidogen and the laminin-nidogen complex to basement membrane collagen type IV
European Journal of Biochemistry, 1989
The laminin-nidogen complex and purified nidogen both bind collagen IV but not other collagens, as shown by solid-state ligand-binding and inhibition assays. Laminin purified from the dissociated complex and a variety of laminin proteolytic fragments failed to bind collagen IV. Complexes formed in solution between nidogen or laminin-nidogen and collagen IV were visualized by rotary shadowing which identified one major binding site about 80 nm away from the C-terminus of the collagen triple helix. A second, weaker binding site may exist closer to its N-terminus. Binding sites of nidogen were assigned to its C-terminal globular domain which also possesses laminin-binding structures. A more diverse collagen-IV-binding pattern was observed for the laminin-nidogen complex, whereby interactions may involve both nidogen and short-arm structures of laminin.
The EMBO Journal, 1989
The whole amino acid sequence of nidogen was deduced from cDNA clones isolated from expression libraries and confirmed to-50% by Edman degradation of peptides. The protein consists of some 1217 amino acid residues and a 28-residue signal peptide. The data support a previously proposed dumb-bell model of nidogen by demonstrating a large N-terminal globular domain (641 residues), five EGF-like repeats constituting the rod-like domain (248 residues) and a smaller C-terminal globule (328 residues). Two more EGF-like repeats interrupt the N-terminal and terminate the C-terminal sequences. Weak sequence homologies (25%) were detected between some regions of nidogen, the LDL receptor, thyroglobulin and the EGF precursor. Nidogen contains two consensus sequences for tyrosine sulfation and for asparagine 3hydroxylation, two N-linked carbohydrate acceptor sites and, within one of the EGF-like repeats an Arg-Gly-Asp sequence. The latter was shown to be functional in cell attachment to nidogen. Binding sites for laminiin and collagen IV are present on the C-terminal globule but not yet precisely localized.
BioMed research international, 2013
The epidermis functions in skin as first defense line or barrier against environmental impacts, resting on extracellular matrix (ECM) of the dermis underneath. Both compartments are connected by the basement membrane (BM), composed of a set of distinct glycoproteins and proteoglycans. Herein we are reviewing molecular aspects of BM structure, composition, and function regarding not only (i) the dermoepidermal interface but also (ii) the resident microvasculature, primarily focusing on the per se nonscaffold forming components perlecan and nidogen-1 and nidogen-2. Depletion or functional deficiencies of any BM component are lethal at some stage of development or around birth, though BM defects vary between organs and tissues. Lethality problems were overcome by developmental stage- and skin-specific gene targeting or by cell grafting and organotypic (3D) cocultures of normal or defective cells, which allows recapitulating BM formation de novo. Thus, evidence is accumulating that BM a...
Nidogen mediates the formation of ternary complexes of basement membrane components
Kidney International, 1993
Nidogen mediates the formation of ternary complexes of basement membrane components. Using a recombinant nidogen we have probed the calcium binding potential of various nidogen domains, examined the binding of nidogen to various basement membrane proteins and assessed the ability of nidogen to mediate the formation of ternary complexes between laminin and heparan sulfate proteoglycan and collagen IV and laminin. The results of these experiments indicate that the Ca2 binding is on the rod-like domain with additional binding observed on the N-terminal Gi domain. With regard to the role of nidogen in mediating complex formation among basement membrane components it was demonstrated that nidogen effectively promotes the formation of a ternary complex between laminin and collagen IV, with both of these components interacting independently with nidogen. Similarly, nidogen mediates a ternary complex formation between laminin and proteoglycan. Interestingly, the interaction between proteoglycan and nidogen is through the protein core of the proteoglycan.