Role of Basement Membranes in Cell Differentiation (original) (raw)
Related papers
The role of laminins in basement membrane function
Journal of Anatomy, 1998
Laminins are a family of multifunctional macromolecules, ubiquitous in basement membranes, and represent the most abundant structural noncollagenous glycoproteins of these highly specialised extracellular matrices. Their discovery started with the difficult task of isolating molecules produced by cultivated cells or extracted from tissues. The development of molecular biology techniques has facilitated and accelerated the identification and the characterisation of new laminin variants making it feasible to identify full-length polypeptides which have not been purified. Further, genetically engineered laminin fragments can be generated for studies of their structure-function relationship, permitting the demonstration that laminins are involved in multiple interactions with themselves, with other components of the basal lamina, and with cells. It endows laminins with a central role in the formation, the architecture, and the stability of basement membranes. In addition, laminins may both separate and connect different tissues, i.e. the parenchymal and the interstitial connective tissues. Laminins also provide adjacent cells with a mechanical scaffold and biological information either directly by interacting with cell surface components, or indirectly by trapping growth factors. In doing so they trigger and control cellular functions. Recently, the structural and biological diversity of the laminins has started to be elucidated by gene targeting and by the identification of laminin defects in acquired or inherited human diseases. The consequent phenotypes highlight the pivotal role of laminins in determining heterogeneity in basement membrane functions.
The Bi-Functional Organization of Human Basement Membranes
PLoS ONE, 2013
The current basement membrane (BM) model proposes a single-layered extracellular matrix (ECM) sheet that is predominantly composed of laminins, collagen IVs and proteoglycans. The present data show that BM proteins and their domains are asymmetrically organized providing human BMs with side-specific properties: A) isolated human BMs roll up in a side-specific pattern, with the epithelial side facing outward and the stromal side inward. The rolling is independent of the curvature of the tissue from which the BMs were isolated. B) The epithelial side of BMs is twice as stiff as the stromal side, and C) epithelial cells adhere to the epithelial side of BMs only. Side-selective cell adhesion was also confirmed for BMs from mice and from chick embryos. We propose that the bi-functional organization of BMs is an inherent property of BMs and helps build the basic tissue architecture of metazoans with alternating epithelial and connective tissue layers.
Basement membrane in health and disease- an enigma to histopathologist
IP Innovative Publication Pvt. Ltd., 2018
Basement membrane is known to play a role in the pathogenesis of inflammatory, tumor invasion, metastases and autoimmune diseases. A basement membrane (BM) is a thick sheet of extracellular matrix molecules, upon which epithelial cells attach and form a boundary between epithelium and the connective tissue. It also provides structural support for epithelial, mesothelial, and endothelial cells and surrounds adipocytes, muscles and Schwann cells. This literature review describes terminologies, histology, ultrastructure, molecular aspects, functions and histochemical studies of basement membrane in health and disease. Keywords: Basement membrane, Extracellular matrix, Health, Disease
The Journal of Cell Biology, 1992
Laminin self-assembles in vitro into a polymer by a reversible, entropy-driven and calcium-facilitated process dependent upon the participation of the short arm globular domains. We now find that this polymer is required for the structural integrity of the collagen-free basement membrane of cultured embryonal carcinoma cells (ECC) and for the supramolecular organization and anchorage of laminin in the collagenrich basement membrane of the Engelbreth-Holm-Swarm tumor (EHS). First, low temperature and EDnA induced the dissolution of ECC basement membranes and released "-,80% of total laminin from the EHS basement membrane. Second, laminin elastase fragments (E,4 and E1 ') possessing the short ann globules of the B1, B2, and A chains selectively acted as competitive ligands that dissolved ECC basement membranes and displaced laminin from the EHS basement membrane into solution. The fraction of laminin re
Molecular architecture of basement membranes
FASEB journal : official publication of the Federation of American Societies for Experimental Biology, 1990
Basement membranes are specialized extracellular matrices with support, sieving, and cell regulatory functions. The molecular architectures of these matrices are created through specific binding interactions between unique glycoprotein and proteoglycan protomers. Type IV collagen chains, using NH2-terminal, COOH-terminal, and lateral association, form a covalently stabilized polygonal framework. Laminin, a four-armed glycoprotein, self-assembles through terminal-domain interactions to form a second polymer network, Entactin/nidogen, a dumbbell-shaped sulfated glycoprotein, binds laminin near its center and interacts with type IV collagen, bridging the two. A large heparan sulfate proteoglycan, important for charge-dependent molecular sieving, is firmly anchored in the basement membrane and can bind itself through a core-protein interaction to form dimers and oligomers and bind laminin and type IV collagen through its glycosaminoglycan chains. Heterogeneity of structure and function ...