Search results for " adhesion"
showing 10 items of 980 documents
Endothelialization and Anticoagulation Potential of Surface-Modified PET Intended for Vascular Applications.
2018
In vascular tissue engineering, great attention is paid to the immobilization of biomolecules onto synthetic grafts to increase bio- and hemocompatibility-two critical milestones in the field. The surface modification field of poly(ethylene terephthalate) (PET), a well-known vascular-graft material, is matured and oversaturated. Nevertheless, most developed methods are laborious multistep procedures generally accompanied by coating instability or toxicity issues. Herein, a straightforward surface modification procedure is presented engineered to simultaneously promote surface endothelialization and anticoagulation properties via the covalent immobilization of gelatin through a photoactivate…
Application of X-ray microanalysis to study of the expression of endothelial adhesion molecules on human umbilical vein endothelial cells in vitro
1994
A semi-quantitative procedure is described, which allows the evaluation of expression levels of endothelial adhesion molecules on cultured human umbilical vein endothelial cells (HUVEC) using energy dispersive X-ray microanalysis (EDX). As a model two adhesion molecules, E-selection (CD62E; ELAM-1/endothelial leukocyte adhesion molecule-1) and ICAM-1 (intercellular adhesion molecule-1; CD54), were localized by the use of the silver-enhancement colloidal gold method after stimulation of HUVEC with endotoxin lipopolysaccharide (LPS), tumour necrosis factor (TNF) or a phorbol ester (PMA). The analysis was performed in a scanning electron microscope (SEM) at an accelerating voltage of 15 kV wit…
Polysialic acid can mediate membrane interactions by interacting with phospholipids
2009
Polysialic acid (polySia) is expressed on the surface of neural cells, neuroinvasive bacterial cells and several tumor cells. PolySia chains attached to NCAM can influence both trans interactions between membranes of two cells and cis interactions. Here, we report on the involvement of phospholipids in regulation of membrane interactions by polySia. The pH at the surface of liposomes, specific molecular area of phosphatidylcholine molecules, phase transition of DPPC bilayers, cyclic voltammograms of BLMs, and electron micrographs of phosphatidylcholine vesicles were studied after addition of polysialic acid free in solution. The results indicate that polySia chains can associate with phosph…
Sphingosine-1-phosphate increases human alveolar epithelial IL-8 secretion, proliferation and neutrophil chemotaxis
2009
Sphingosine-1-phosphate (S1P) has been presented recently as a pro-inflammatory agent in the airway epithelium since S1P levels are increased in bronchoalveolar lavage fluid of human asthmatics. However, the effects of S1P over the alveolar epithelium and neutrophil interactions are poorly understood. Here, we show that S1P increased interleukin 8 (IL-8) gene expression and protein secretion and proliferation in alveolar epithelial cells A549 at physiological concentrations (1 microM). At the same time, S1P increased intracellular Ca2+ concentration (potency 17.91 microM, measured by epifluorescence microscopy), phospholipase D (PLD) activity (measured by chemiluminiscence method) and extra…
Analysis of cell-free human alpha1 integrin with a monoclonal antibody to the I-domain: detection in ocular fluid and function as an adhesion substra…
2002
The alpha1 beta1 integrin, an inserted (1) domain containing collagen receptor, is expressed in the cell surface membrane of normal and malignant cells, and may play a role in their migration through tissues or in metastatic spread. Here we report that a functional anti-human alpha1beta1 integrin monoclonal antibody (mAb) (1B3.1) directly and specifically binds plastic bound recombinant human alpha1 I-domain protein containing the collagen binding site. Detection was diminished by acidification of the I-domain protein but was enhanced by increasing concentrations of Mg2+ cation. Furthermore, we detected binding of the mAb to proteins from the ocular fluids of 6 patients, with the highest co…
Microangiectasias: Structural regulators of lymphocyte transmigration
2003
The migration of lymphocytes into inflammatory tissue requires the migrating cell to overcome mechanical forces produced by blood flow. A generally accepted hypothesis is that these forces are overcome by a multistep sequence of adhesive interactions between lymphocytes and endothelial cells. This hypothesis has been recently challenged by results demonstrating wall shear stress on the order of 20 dyn/cm 2 in vivo and infrequent lymphocyte–endothelial adhesion at wall shear stress >1–2 dyn/cm 2 in vitro . Here, we show that lymphocyte slowing and transmigration in the skin is associated with microangiectasias, i.e., focal structural dilatations of microvessel segments. Microangiectasias…
Requirement of caveolae microdomains in extracellular signal-regulated kinase and focal adhesion kinase activation induced by endothelin-1 in primary…
1999
Endothelin-1 (ET-1) mitogenic activity in astrocytes is mediated by the activation of the extracellular signal-regulated kinase (ERK) pathway together with the Rho-dependent activation of the focal adhesion kinase (FAK) pathway. To clarify the mechanisms responsible for the coordinate activation of both pathways in the ET-1 signal propagation, the involvement of caveolae microdomains, suggested to play a role in signal transduction, was evaluated. In this study, it is reported that caveolae of primary astrocytes are enriched in endothelin receptor (ETB-R). Furthermore, signaling molecules such as the adaptor proteins Shc and Grb2, and the small G protein Rho, also reside within these microd…
IAPs and cell migration.
2015
Inhibitors of apoptosis (IAPs) constitute a family of cell signaling regulators controlling several fundamental biological processes such as innate immunity, inflammation, cell death, cell proliferation, and cell differentiation. Increasing evidence from in vivo and in vitro studies indicate a function for IAPs in the modulation of invasive and migratory properties of cells. Here, we present and discuss the mechanisms whereby IAPs can control cell migration.
Dissecting the different biological effects of oncogenic Ras isoforms in cancer cell lines: Could stimulation of oxidative stress be the one more wea…
2012
Abstract Ras proteins are small GTPase functioning as molecular switches that, in response to particular extracellular signalling, as growth factors, activate a diverse array of intracellular effector cascades regulating cell proliferation, differentiation and apoptosis. Human tumours frequently express Ras proteins (Ha-, Ki-, N-Ras) activated by point mutations which contribute to malignant phenotype, including invasiveness and angiogenesis. Despite the common signalling pathways leading to similar cellular responses, studies clearly demonstrate unique roles of the Ras family members in normal and pathological conditions and the lack of functional redundancy seems to be explainable, at lea…
Evaluation of the Role of Candida albicans Agglutinin-Like Sequence (Als) Proteins in Human Oral Epithelial Cell Interactions
2012
The fungus C. albicans uses adhesins to interact with human epithelial surfaces in the processes of colonization and pathogenesis. The C. albicans ALS (agglutinin-like sequence) gene family encodes eight large cell-surface glycoproteins (Als1-Als7 and Als9) that have adhesive function. This study utilized C. albicans Δals mutant strains to investigate the role of the Als family in oral epithelial cell adhesion and damage, cytokine induction and activation of a MAPK-based (MKP1/c-Fos) signaling pathway that discriminates between yeast and hyphae. Of the eight Δals mutants tested, only the Δals3 strain showed significant reductions in oral epithelial cell adhesion and damage, and cytokine pro…