Integrins and extracellular matrix

Fibronectin is a cell-surface compound with domains that interact with many compounds, including integrins and extracellular matrix proteins such as collagen. Fibronectin expression can be stimulated by I GF-[3 and by CTGF,41 although increases in fibronectin expression can also be mediated by TGF-(3-independent means 42 We found some evidence of increased expression of fibronectin in FBC tissue, but not to the degree in which I GF-[3, CTGF, and decorin were expressed.16,17... 

Several families of integral proteins in the plasma membrane provide specific points of attachment between cells, or between a cell and extracellular matrix proteins. Integrins are heterodimeric proteins (two unlike subunits, a and /3) anchored to the plasma membrane by a single hydrophobic transmembrane helix in each subunit (Fig. 11-22 see also Fig. 7-30). The large extracellular domains of the a and /3 subunits combine to form a specific binding site for extracellular proteins... 

Bergelson JM, Chan BM, Finberg RW, Hemler ME The integrin VLA-2 binds echovinis 1 and extracellular matrix ligands by different mechanisms. J Clin Invest 92 232-239,1993... 

Fibronectin. Fibronectin is expressed in and around neoplastic blood vessels during tumor growth and angiogenesis. Fibronectin is an extracellular adhesion glycoprotein that binds to integrin receptors and mediates interactions between cells and extracellular matrix components. Antibodies against fibronectin have been studied for targeting. " ... 

Integrins are the major type of cell surface receptors and are formed by a heterodimer with a and P subunits. Most integrins bind extracellular matrix components like fibronectin, collagen or intronectin. It seems that integrins activate PTKs clustering. 

Mousa SA, Lorelli W, Campochiaro PA. 1999. Role of hypoxia and extracellular matrix-integrin binding in the modulation of angiogenic growth factors secretion by retinal pigmented epithelial cells. J Cell Biochem 74 135-143. 

Integrins Transmembrane a)S-heterodimer a 165 kDa j , 90-120 kDa Plasmalemma Binding to laminins, fibronectin, collagen specificity depends on a)S composition Maintenance of cell to basement membrane and extracellular matrix binding... 

Matrix Proteins for Cell Adhesion. Cell adhesion in a receptor-mediated fashion is key for cellular processes such as intracellular signaling, synthesis of ECM proteins, and mitosis. Specific cell adhesion to scaffolds often occurs via ECM molecules that are presented on the scaffold surface. One adhesion study confirmed that smooth muscle cells adhere via integrins to extracellular matrix proteins (Nikolovski and Mooney, 2000). By immobilizing matrix proteins to the material, cell adhesion can be facilitated. 

Crocidolite Intraperitoneal injection in rats mRNA expression pattern Upregulation of c-myc,fra-l and egfr Sand HU et al. (2000) Fibres may affect integrin-linked signal transduction and extracellular matrix proteins... 

Hence, integrins, the extracellular matrix, and the cytoskeleton control tissue structure around the implant and tissue development by mediating mechanotransduction. 

Integrins, selectins, cadherins, claudins and other cell adhesion molecules are involved in the interaction of cells with other cells or with extracellular matrix components. Some of them also serve as receptors by inducing outside-in or additional inside-out signaling. 

Integrins constitute a large family of a (3 heterodimeric cell surface, transmembrane proteins that interact with a large number of extracellular matrix components through a metal ion-dependent interaction. The term integrin reflects their function in integrating cell adhesion and migration with the cystoskeleton. 

Integrins themselves are found on nearly all cells and mediate several physiological responses, such as cell-cell and cell-matrix interactions. Three families of integrins, each family with a common beta subunit in combination with distinct alpha subunits, have been recognized. The beta 1 family, also called very late lymphocyte-activation antigen or VLA, has receptors mediating extracellular matrix interactions with molecules such as collagen, laminin, and fibronectin. Naturally, platelets contain many of the receptors of the beta 1 family. 

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