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Reduced Adhesion (reduced + adhesion)
Selected AbstractsFibroblast activation protein increases apoptosis, cell adhesion, and migration by the LX-2 human stellate cell line,HEPATOLOGY, Issue 4 2005Xin Maggie Wang Injury and repair in chronic liver disease involve cell adhesion, migration, apoptosis, proliferation, and a wound healing response. In liver, fibroblast activation protein (FAP) has both collagenase and dipeptidyl peptidase IV (DPIV) activities and is expressed only by activated hepatic stellate cells (HSC) and myofibroblasts, which produce and degrade extracellular matrix (ECM). FAP was colocalized with collagen fibers, fibronectin, and collagen type I in human liver. FAP function was examined in vitro by expressing green fluorescent protein FAP fusion protein in cell lines cultured on collagen-I, fibronectin, and Matrigel. Glutamates at 203 and 204 as well as serine624 of FAP were essential for peptidase activity. Human embryonic kidney 293T cells overexpressing FAP showed reduced adhesion and migration. FAP overexpression in the human HSC line LX-2 caused increased cell adhesion and migration on ECM proteins as well as invasion across transwells in the absence or presence of transforming growth factor beta-1. FAP overexpression enhanced staurosporine streptomyces,stimulated apoptosis in both cell lines. Interestingly, the enzyme activity of FAP was not required for these functions. Overexpressing FAP increased the expression of matrix metalloproteinase-2 and CD44 and reduced integrin-,1 expression in 293T cells, suggesting potential pathways of FAP-mediated impairment of cell adhesion and migration in this epithelial cell line. In conclusion, these findings further support a pro-fibrogenic role for FAP by indicating that, in addition to its enzymatic functions, FAP has important nonenzymatic functions that in chronic liver injury may facilitate tissue remodeling through FAP-mediated enhancement of HSC cell adhesion, migration, and apoptosis. Supplementary material for this article can be found on the HEPATOLOGY website (http://www.interscience.wiley.com/jpages/0270-9139/suppmat/index.html). (HEPATOLOGY 2005;42:935,945.) [source] The regulation of integrin-linked kinase in human platelets: evidence for involvement in the regulation of integrin ,2,1JOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 8 2004J. M. Stevens Summary.,Background: Activation of the platelet integrin ,2,1 is closely regulated due to the high thrombogenicity of its ligand. As a ,1 interacting kinase, ILK represents a candidate intracellular regulator of ,2,1 in human platelets. Objectives We investigated the regulation of ILK in human platelets and the role of ILK in regulating ,2,1 activation in HEL cells, a megakaryocytic cell line. Methods: An in-vitro kinase assay was used to determine the effect of platelet agonists on ILK kinase activity together with the contribution of PI3K and PKC on ILK activation. Interaction of ILK with ,1 -integrin subunits was investigated by coimmunoprecipitation and the role of ILK in regulating ,2,1 function assessed by overexpression studies in HEL cells. Results: We report that collagen and thrombin modulate ILK kinase activity in human platelets in an aggregation-independent manner. Furthermore, ILK activity is dually regulated by PI3K and PKC in thrombin-stimulated platelets and regulated by PI3K in collagen-stimulated cells. ILK associates with the ,1 -integrin subunits immunoprecipitated from platelet cell lysates, an association which increased upon collagen stimulation. Overexpression of ILK in HEL cells enhanced ,2,1 -mediated adhesion whereas overexpression of kinase-dead ILK reduced adhesion, indicating a role for this kinase in the positive regulation of ,2,1. Conclusions: Our findings that ILK regulates ,2,1 in HEL cells, is activated in platelets and associates with ,1 -integrins, raise the possibility that it may play a key role in adhesion events upon agonist stimulation of platelets. [source] Comparison of flat film to total package water vapour transmission rates for several commercial food wrapsPACKAGING TECHNOLOGY AND SCIENCE, Issue 1 2002Matthew D. Steven Abstract The barrier properties of a package are the sum of material and seal permeations. Although addressed for hermetically sealed and modified atmosphere packages, little consideration of total package permeation has been given to commercial food wraps. Standard protocols were used to compare the water vapour transmission rates (WVTRs) of materials and packages for seven commercial food wraps: aluminum foil; poly(vinylidene chloride) (PVdC) film; three poly(ethylene) (PE) films; an adhesive-modified PE film; and plasticized poly(vinyl chloride) (PVC) film. Water ingress for a complete package was compared to calculated material permeation based on film WVTRs. Film-to-glass adhesion strength was also measured. Model systems (desiccant) were compared to foods at ambient and refrigeration temperatures. Aluminum foil had the lowest material WVTR (0.10 g/h/m2), closely followed by PVdC (0.13 g/h/m2). These WVTRs were approximately five-fold lower than the PEs (,0.65 g/h/m2), which were nearly 10-fold lower than PVC (4.9 g/h/m2). The adhesive-modified PE film had the lowest difference between material and package transmission rates (0.7 E-03 g/h), approximately half that of the PVdC film (1.1 E-03 g/h), which was significantly lower than the remaining films (2.3 E-03 ,3.9 E-03 g/h). The adhesive PE film had the strongest film,glass adhesion. Ambient food product test results were similar to model system (desiccant) results, but refrigerated trials showed significantly different relative package transmission rates. This was attributed to the reduced adhesion of most wraps at refrigeration temperatures. Copyright © 2002 John Wiley & Sons, Ltd. [source] Gold-coated fused-silica sheathless electrospray emitters based on vapor-deposited titanium adhesion layersRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 14 2003Stefan Nilsson Gold-coated fused-silica electrospray (ES) emitters based on vapor-deposited adhesion layers of titanium have been manufactured to investigate the possibilities of producing durable ES emitters applicable in chip-based analytical devices. The stabilities of the emitters were studied by both electrospray and electrochemical experiments and a marked increase in the emitter lifetime, compared to that for Cr/Au coated emitters, was found for the Ti/Au emitters in the ES durability tests. This indicates that Ti (rather than Cr) adhesion layers should be used in association with large-scale fabrication of ES emitters by vapor-deposition techniques. The lifetime of about 500,700 hours also allowed the Ti/Au-coated emitter to be used as an integrated part of a capillary liquid chromatography column coupled to a mass spectrometer in a series of LC/MS experiments. The Ti/Au coating was further studied by electrochemical techniques and scanning electron microscopy in conjunction with X-ray spectroscopy. It is shown that the eventual failure of the Ti/Au emitters in ES experiments was due to an almost complete detachment of the gold layer. Experimental evidence suggests that the detachment of the gold coating was due to a reduced adhesion to the titanium layer during oxidation in positive electrospray. Most likely, this was caused by the formation of an oxide layer on the titanium film. It is thus shown that unlimited emitter stabilities are not automatically obtained even if the metallic adhesion layer is stabilized by an oxide formation under positive electrospray conditions. Copyright © 2003 John Wiley & Sons, Ltd. 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