Search results for "Nectin"
showing 10 items of 355 documents
Fibronectin-bound α5β1 integrins sense load and signal to reinforce adhesion in less than a second
2017
Integrin-mediated mechanosensing of the extracellular environment allows cells to control adhesion and signalling. Whether cells sense and respond to force immediately upon ligand-binding is unknown. Here, we report that during adhesion initiation, fibroblasts respond to mechanical load by strengthening integrin-mediated adhesion to fibronectin (FN) in a biphasic manner. In the first phase, which depends on talin and kindlin as well as on the actin nucleators Arp2/3 and mDia, FN-engaged α5β1 integrins activate focal adhesion kinase (FAK) and c-Src in less than 0.5 s to steeply strengthen α5β1- and αV-class integrin-mediated adhesion. When the mechanical load exceeds a certain threshold, fib…
Promotion of osteogenic cell response using quasicovalent immobilized fibronectin on titanium surfaces: introduction of a novel biomimetic layer syst…
2012
Purpose Despite the undeniable potential of cell adhesion molecules such as fibronectin to support osteogenic cell responses and consecutive dental implant healing, the most beneficial mode of application onto titanium implant surfaces still requires investigation. Unspecific fibronectin adsorption on titanium dioxide (TiO2) surfaces can result in low-loading, high-desorption rates and protein–metal interactions with impaired biologic activity. The aim of the present study was to monitor the osteogenic cell responses (cell adhesion, proliferation, and differentiation) specifically to fibronectin biofunctionalized TiO2. Materials and Methods An innovative biomimetic streptavidin-biotin layer…
TOPOLOGY OPTIMIZATION OF A CONNECTING ROD FOR AN INTERNAL COMBUSTION ENGINE
2009
The topology optimization of a structure is a process that allows to establish if in a point of an assigned domain there should be some material. No assumption is made with regard to the number and the distribution of the contours and the final topology, that can be very different compared to that one initially hypothesized. In this paper a study related to the topology optimization of a connecting rod for an internal combustion engine is presented. The used technique for the optimization is the density (or distribution of material) method. The developed application, besides giving an innovative solution of the topology of the connecting rod with a lower mass in comparison with the initial …
Analysis of the Biological Response of Endothelial and Fibroblast Cells Cultured on Synthetic Scaffolds with Various Hydrophilic/Hydrophobic Ratios: …
2009
In this study we developed polymer scaffolds intended as anchorage rings for cornea prostheses among other applications, and examined their cell compatibility. In particular, a series of interconnected porous polymer scaffolds with pore sizes from 80 to 110 microns were manufactured varying the ratio of hydrophobic to hydrophilic monomeric units along the polymer chains. Further, the effects of fibronectin precoating, a physiological adhesion molecule, were tested. The interactions between the normal human fibroblast cell line MRC-5 and primary human umbilical vein endothelial cells (HUVECs) with the scaffold surfaces were evaluated. Adhesion and growth of the cells was examined by confocal…
Fibronectin urothelial gene expression as a new reliable biomarker for early detection of local toxicity secondary to adjuvant intravesical therapy f…
2020
Background: A marker of urothelial damage could be helpful for early detection and monitoring of local toxicity due to intravesical therapy for non-muscle invasive bladder cancer (NMIBC). The aim of the study was to investigate the correlation between fibronectin (FN) gene expression in bladder washings and local toxicity secondary to adjuvant intravesical therapy. Materials and methods: Patients undergoing adjuvant intravesical therapy for NMIBC and age-matched healthy patients were enrolled. Real time polymerase chain reaction was performed to analyze FN expression in bladder washings. Local toxicity was classified as: 0–1 mild (no medical therapy), 2 moderate (medical therapy and/or inst…
Integrin-dependent and -independent functions of astrocytic fibronectin in retinal angiogenesis
2011
Fibronectin (FN) is a major component of the extracellular matrix and functions in cell adhesion, cell spreading and cell migration. In the retina, FN is transiently expressed and assembled on astrocytes (ACs), which guide sprouting tip cells and deposit a provisional matrix for sprouting angiogenesis. The precise function of FN in retinal angiogenesis is largely unknown. Using genetic tools, we show that astrocytes are the major source of cellular FN during angiogenesis in the mouse retina. Deletion of astrocytic FN reduces radial endothelial migration during vascular plexus formation in a gene dose-dependent manner. This effect correlates with reduced VEGF receptor 2 and PI3K/AKT signalli…
Comparison of growth & function of endothelial progenitor cells cultured on deproteinized bovine bone modified with covalently bound fibronectin …
2016
Objectives The objective of this study was to assess and compare the growth and function of Endothelial Progenitor Cells (EPCs) cultured on covalently bonded Vascular Endothelial Growth Factor (VEGF) and covalently bonded Fibronectin (FN) coating on deproteinized bovine bone (DBB) (test samples), compared to non-modified DBB blocks (control sample). Materials and methods The test samples were prepared by plasma polymerization of allylamine onto DBB blocks. Group1 of test samples were prepared with VEGF coating (VEGF-DBB) where as the Group2 test samples were coated with FN (FN-DBB). Non-modified DBB blocks served as a Control. EPCs were isolated and cultivated from buffy coats of peripheral…
Endothelial progenitor cells: Are they displaying a function in autoimmune disorders?
2016
Endothelial Progenitor Cells (EPCs) are bone marrow derived cells able to differentiate in mature endothelial cells (EC) contributing to the generation of new vessels, connecting to fibronectin, and forming colonies and/or colony forming units. Since circulating EPCs can be actively considered part of endothelial damage in several cardiovascular diseases and autoimmune disorders the possibility to have a measure for endothelium damage should be considered of interest to predict the patient out-come. At the same time the EPCs proliferative and regenerative role could be considered for therapeutic applications. Studies have been performed to elucidate the role of EPCs in Systemic Sclerosis an…
Fat storing cells (FSC) of rat liver synthesize and secrete fibronectin
1987
Summary Fat storing cells (FSC) of rat liver were isolated and kept in culture for up to 2 weeks. Freshly isolated cells and cells in culture were characterized functionally (vitamin A content) and morphologically. Their synthetic capacity for fibronectin was studied quantitatively by ELISA-measurement and qualitatively by biosynthetic labeling, immunoprecipitation and SDS-PAGE analysis. The synthesis product and the kinetics of the synthesis and secretion were compared with those obtained from culture of hepatocytes. FSC were shown to synthesize and secrete fibronectin under the culture conditions used. No fibronectin synthesis was detected during the first 3 days of culture. Thereafter th…
Vitamin A Deficiency and Alterations in the Extracellular Matrix
2014
Vitamin A or retinol which is the natural precursor of several biologically active metabolites can be considered the most multifunctional vitamin in mammals. Its deficiency is currently, along with protein malnutrition, the most serious and common nutritional disorder worldwide. It is necessary for normal embryonic development and postnatal tissue homeostasis, and exerts important effects on cell proliferation, differentiation and apoptosis. These actions are produced mainly by regulating the expression of a variety of proteins through transcriptional and non-transcriptional mechanisms. Extracellular matrix proteins are among those whose synthesis is known to be modulated by vitamin A. Reti…