Collagen IV of basement membranes: III. Chloride pressure is a primordial innovation that drives and maintains the assembly of scaffolds.

Collagen IV scaffold is a primordial innovation enabling the assembly of a fundamental architectural unit of epithelial tissues-a basement membrane attached to polarized cells. A family of six α-chains (α1 to α6) coassemble into three distinct protomers that form supramolecular scaffolds, noted as collagen IV, collagen IV, and collagen IV. Chloride ions play a pivotal role in scaffold assembly, based on studies of NC1 hexamers from mammalian tissues.

Basement membrane collagen IV: Isolation of functional domains.

Collagen IV is a major constituent of basement membranes, specialized form of extracellular matrix that provides a mechanical support for tissues, serves as a polyvalent ligand for cell adhesion receptors and as a scaffold for other proteins, and plays a key role in tissue genesis, differentiation, homeostasis, and remodeling. Collagen IV underlies the pathogenesis of several human disorders including Goodpasture's disease, Alport's syndrome, diabetic nephropathy, angiopathy, and porencephaly. While the isolation of the collagen IV molecules from tissues is an ultimate prerequisite for structural and functional studies, it has been always hampered by the protein insolubility due to extensive intermolecular crosslinking and noncovalent associations with other components of basement membranes.

Collagen IV and basement membrane at the evolutionary dawn of metazoan tissues.

The role of the cellular microenvironment in enabling metazoan tissue genesis remains obscure. Ctenophora has recently emerged as one of the earliest-branching extant animal phyla, providing a unique opportunity to explore the evolutionary role of the cellular microenvironment in tissue genesis. Here, we characterized the extracellular matrix (ECM), with a focus on collagen IV and its variant, spongin short-chain collagens, of non-bilaterian animal phyla.

A unique covalent bond in basement membrane is a primordial innovation for tissue evolution.

Basement membrane, a specialized ECM that underlies polarized epithelium of eumetazoans, provides signaling cues that regulate cell behavior and function in tissue genesis and homeostasis. A collagen IV scaffold, a major component, is essential for tissues and dysfunctional in several diseases. Studies of bovine and Drosophila tissues reveal that the scaffold is stabilized by sulfilimine chemical bonds (S = N) that covalently cross-link methionine and hydroxylysine residues at the interface of adjoining triple helical protomers.

Mechanism of perturbation of integrin-mediated cell-matrix interactions by reactive carbonyl compounds and its implication for pathogenesis of diabetic nephropathy.

Perturbation of interactions between cells and the extracellular matrix (ECM) of renal glomeruli may contribute to characteristic histopathological lesions found in the kidneys of patients with diabetic nephropathy. However, the mechanism by which the diabetic conditions may affect cell-ECM interactions is unknown. Existing hypotheses suggest a role of glucose in direct modification of ECM.

Hormone/growth factor interactions mediating epithelial/stromal communication in mammary gland development and carcinogenesis.

Epithelial/mesenchymal interactions begin during embryonic development of the mammary gland and continue throughout mammary gland development into adult life. Stromal and epithelial growth factors that may mediate interactions between these compartments of the mammary gland are reviewed. Since mammogenic hormones are the primary regulators of mammary gland development, special consideration is given to hormonal regulation of growth factors in order to explore the integration of hormones and growth factors in the regulation of mammary gland growth and neoplasia.