Disease relevance of Vtn

• In initial experiments, Vn levels were measured during the surgically induced acute phase response in humans [1].
• When BSP was used as an affinity matrix to isolate a cell surface receptor from rat osteosarcoma cells, a protein composed of polypeptides similar in size to those of a previously characterized vitronectin receptor was obtained [2].
• The leading edges of migrating osteoclasts, and the attachment structure, a broad vinculin band, which forms before bone resorption, also expressed vitronectin receptor, particularly when the antibody against the alpha v subunit was used.(ABSTRACT TRUNCATED AT 250 WORDS)[3]
• Pretreatment of PVG/c+ rats with antibodies against vitronectin, followed by administration of ER4G, resulted in the immediate development of proteinuria (maximum, 119 mg/24 h on day 3; P < 0.05), whereas Wistar rats did not become more proteinuric [4].
• All these effects were inhibited by pertussis toxin, or by antibodies directed against the urokinase receptor (uPAR) or against the VN receptor alpha(v)beta(3) suggesting that an association between the two receptors is required to mediate both signals [5].

High impact information on Vtn

• Silicone elastomer strain plates were coated at varying densities with elastin, laminin, type I collagen, fibronectin, or vitronectin [6].
• Overexpression of TAP20 decreased cell adhesion and enhanced migration on vitronectin and tube formation in three-dimensional culture [7].
• Vitronectin at sites of cell-substrate contact in cultures of rat myotubes [8].
• Our results are consistent with the hypothesis that vitronectin is present at all sites of cell-substrate contact, but that its antigenic sites are obscured by material deposited by both myotube and fibroblast cells [8].
• Furthermore, the vitronectin receptor, which has known specificity for osteopontin, is shown preferentially localized at the corresponding area of the osteoclast plasma membrane [9].

Chemical compound and disease context of Vtn

• Our experimental model was represented by CMH5123 cells, a line of neoplastic hepatocytes derived from the minimal deviation Morris hepatoma 5123c of the rat, which adhered to substrata coated with fetal calf serum (FCS) by an integrin-mediated mechanism, being vitronectin the specific serum protein which sustained cell adhesion [10].
• The interaction of vascular endothelial cells and dorsal root ganglion neurites is mediated by vitronectin and heparan sulfate proteoglycans [11].
• Because vitronectin and its receptor may have a role in various renal physiological and pathological processes, we evaluated their expression in renal tissues of streptozotocin-induced short- and long-term hyperglycemic rats by applying quantitative immunoelectron microscopy and Western blot analysis [12].

Biological context of Vtn

• To characterize the primary structure of rat Vn, a cDNA library constructed from freshly isolated rat hepatocytes, was screened with a human Vn cDNA probe [13].
• Vitronectin, an ECM component that is generally prominent in wound healing, has been detected in PCO specimens [14].
• Here we set out to investigate the distribution of vitronectin in the lens and determine how it, and other ECM components, influence the lens epithelial phenotype [14].
• Vitronectin and its integrin receptor subunits alpha(v) are expressed in the inner part of the external germinal layer where granule cell precursors exit the cell cycle and commence differentiation [15].
• Vitronectin regulates Sonic hedgehog activity during cerebellum development through CREB phosphorylation [15].

Anatomical context of Vtn

• To specify the liver cell type involved in the biosynthesis of Vn, we used a competitive PCR-assay to discriminate between expression levels [13].
• We found that expression of Vn in hepatocytes is at least 1000-fold higher than in Kupffer cells and 3000-fold higher than in endothelial liver cells [13].
• Vitronectin is present in epithelial cells of the intact lens and promotes epithelial mesenchymal transition in lens epithelial explants [14].
• In explants cultured on vitronectin and fibronectin, but not laminin, cell nuclei showed prominent reactivity for Smad 2/3 [14].
• Oligodendrocytes bound to surfaces coated with fibronectin, vitronectin and a protein component of the glial matrix [16].

Associations of Vtn with chemical compounds

• Affinity-purified antibodies to the serum glycoprotein, vitronectin, were used to study sites of cell-substrate contact in cultures of rat myotubes and fibroblasts [8].
• The tyrosine kinase blockers genistein and methyl 2,5-dihydroxycinnamate caused significant concentration-dependent inhibitions of Lp increases due to vitronectin and zymosan-activated serum [17].
• No changes were observed with either vitronectin or the integrin chain alpha(v) [18].
• Peptides containing the tripeptide sequence Arg-Gly-Asp can duplicate or inhibit the cell attachment-promoting effects of fibronectin and vitronectin [19].
• To analyze the individual effects of raised corticosterone and IL-6 levels on the expression of hepatic Vn mRNA, rats were injected (i.p.) with either dexamethasone or purified recombinant rat IL-6 [1].

Physical interactions of Vtn

• Vitronectin receptor (alpha(v)beta(3)) blockade interferes with binding of this integrin to MMP-2 and proteolyzed collagen, thereby reducing cell invasion [20].

Regulatory relationships of Vtn

• These results demonstrate that the adhesion of vitronectin to rat VSMCs is inhibited by ET-1 via the ET(A) receptors by suppressing integrin alpha(v) gene transcription, suggesting that ET-1 is involved in regulation of vascular integrin alpha(v) gene expression [21].
• Plasminogen activator inhibitor-1 and vitronectin promote the cellular clearance of thrombin by low density lipoprotein receptor-related proteins 1 and 2 [22].
• In the present investigation it was shown that RMCP-1 is inhibited by vitronectin (VN), an RGD-containing adhesive glycoprotein with heparin-binding properties [23].
• From these results, it is suggested that vitronectin is synthesized by myocardial cells and some cushion mesenchymal cells, and that vitronectin inhibits cell movement on fibronectin [24].

Other interactions of Vtn

• Vitronectin overrides a negative effect of TNF-alpha on astrocyte migration [25].
• In addition, cell migration mediated by fibronectin or vitronectin, but not that induced by insulin, was impaired by overexpression of the SHP-2 mutant [26].
• In group 1, degradation of the collagen layer in the anastomosis was observed, with disappearance of immunostaining for fibronectin and vitronectin on day 3 [27].
• In both groups 3 and 4, these changes were significantly attenuated with intense immunostaining for plasminogen activator inhibitor-1; fibronectin and vitronectin were seen particularly among collagen fibers on both sides of the anastomosis [27].
• We considered the Lp effects of vitronectin and the vitronectin-containing complement complex SC5b-9, which ligate the integrin alpha v beta 3 [17].

Analytical, diagnostic and therapeutic context of Vtn

• Vitronectin expression was analyzed in embryonic and postnatal rodent lens development by immunohistochemistry, western blotting, and in situ hybridization [14].
• When stained for vitronectin by indirect immunofluorescence, large areas of the substrate were brightly labeled [8].
• With VN or beta3 antibody coated onto microbeads and presented as an insoluble ligand, current was also inhibited [28].
• The expression of Vn mRNA in the liver increased markedly as early as 3 h after treatment in these models and remained elevated up to 18 h [1].
• Spatial organization of microfilaments and vitronectin receptor, alpha v beta 3, in osteoclasts. A study using confocal laser scanning microscopy [3].

References