Search results for " molecule"
showing 10 items of 1523 documents
Evolution of Cell Adhesion Systems: Evidence for Arg-Gly-Asp-Mediated Adhesion in the Protozoan Neoparamoeba aestuarina
1995
Developmental processes in multicellular organisms require structural elements, such as adhesion molecules, to stabilize cells at functional positions. In vertebrates, a series of extracellular matrix proteins, e.g. fibronectin and laminin, are involved in cell adhesion. These proteins contain Arg-Gly-Asp [RGD] at their binding sites. Here we show that at concentrations above 2 mM the peptide GRGDSPK, comprising the tripeptide RGD (Arg-Gly-Asp), prevents the adhesiveness of cells of the marine amoeba Neoparamoeba aestuarina. In addition, elevated levels of GRGDSPK cause cells to alter their shapes from those with digitiform subpseudopodia to rounded cells with small lobed pseudopodia. These…
Mechanisms of endothelial cell activation by endocannabinoid 2-arachidonoylglycerol
2020
Abstract Background Endothelial dysfunction promotes atherogenesis, vascular inflammation, and thrombus formation. Reendothelialization after angioplasty is required in order to restore vascular function and to prevent stent thrombosis. The endocannabinoid (eCB) 2-arachidonoylglycerol (2-AG) is a known modulator of inflammation. Earlier studies have demonstrated the relevance of this endocannabinoid in human pathophysiology during coronary artery disease and in murine experimental atherogenesis. However, evidence on the impact of 2-AG on endothelial cell function remains scarce. Methods Endothelial repair was studied in two treatment groups of wildtype mice following electrical denudation o…
Quantification of HSP27 and HSP70 Molecular Chaperone Activities
2011
Stress-inducible heat-shock proteins (HSPs, like HSP70 and HSP27) are molecular chaperones that -protect cells from stress damage by keeping cellular proteins in a folding competent state and preventing them from irreversible aggregation. HSP27 and HSP70 chaperone activities are useful indicators to test chemical products and physical stress impact on protein denaturation, to select HSP inhibitors, or to -determine the implication of the chaperone function in other HSP activities, such as apoptosis. We have developed two simple and fast chaperone activity tests for HSP27 and HSP70 that we initially set up to test the effect of potential HSP inhibitors obtained after screening of chemical an…
Overcoming of P-glycoprotein-mediated multidrug resistance of tumors in vivo by drug combinations
2014
Summary Inhibition of P-glycoprotein represents an attractive possibility to modulate resistance of cancer cells to anticancer drugs. One major strategy to overcome P-glycoprotein-mediated multidrug resistance (MDR) of tumors is to increase intracellular concentrations of anticancer drugs. This can be achieved by blocking of P-glycoprotein-mediated drug efflux using synthetic or natural small molecules or monoclonal antibodies, which bind to various parts of the efflux channel. Another possibility to increase intracellular drug concentrations can be reached by nanoparticles. A further major strategy to overcome MDR involves the downregulation of P-glycoprotein expression either by therapeut…
The Origin of Metazoan Complexity: Porifera as Integrated Animals
2011
SYNOPSIS. Sponges [Porifera] are the phylogenetically oldest metazoan phylum still extant today; they share the closest relationship with the hypothetical common metazoan ancestor, the Urmetazoa. During the past 8 years cDNAs coding for proteins involved in cell-cell- and cell-tissue interaction have been cloned from sponges, primarily from Suberites domuncula and Geodia cydonium and their functions have been studied in vivo as well as in vitro. Also, characteristic elements of the extracellular matrix have been identified and cloned. Those data confirmed that all metazoan phyla originate from one ancestor, the Urmetazoa. The existence of cell adhesion molecules allowed the emergence of a c…
Virulent and nonvirulent Flavobacterium columnare colony morphologies: characterization of chondroitin AC lyase activity and adhesion to polystyrene
2011
Aims: Colony morphology variants of fish pathogenic Flavobacterium columnare were studied to clarify the role of colony morphology change in the virulence of the bacterium. Typical rhizoid colony (Rz) variants are virulent and moderately adherent, nonrhizoid rough (R) colony variants are nonvirulent and highly adherent, and soft colony (S) variants are nonvirulent and poorly adherent. Methods and Results: Chondroitin AC lyase activity, adhesion to polystyrene at different temperatures and after modification of bacterial surface, and lipopolysaccharide (LPS) profiles of the variants were studied. The chondroitinase activity was significantly higher in the virulent, rhizoid variants than in…
Mildronate as a Regulator of Protein Expression in a Rat Model of Parkinson’s Disease
2011
Background. Mildronate (3-[2,2,2-trimethylhydrazinium] propionate dihydrate) traditionally is a well-known cardioprotective drug. However, our recent studies convincingly demonstrated its neuroprotective properties. The aim of the present study was to evaluate the influence of mildronate on the expression of proteins that are involved in the differentiation and survival of the nigrostriatal dopaminergic neurons in the rat model of Parkinson’s disease (PD). The following biomarkers were used: heat shock protein 70 (Hsp70, a molecular chaperone), glial cell line-derived nerve growth factor (GDNF, a growth factor promoting neuronal differentiation, regeneration, and survival), and neural cell …
Bis-urea macrocycles with a deep cavity.
2015
Two configurational isomers of bis-urea macrocycles have been synthesized, and their neutral molecule recognition was studied by X-ray crystallography and (1)H NMR experiments. Cooperative action between the deep cavity and the urea groups and the influence of dipole alignments on molecular recognition are discussed.
Coupling Proteomics and Fermentation Technology for the Improvement of Bioactive Molecule Production Yield in Actinomycetes
2013
Copyright: © 2013 Gallo. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Most bioactive molecules (like anticancers, antitumors, antibiotics, immunosuppressants, insecticidals, antivirals, herbicidals, antifungals) with valuable industrial and market value are naturally produced by actinomycetes [1-4], Gram-positive filamentous bacteria widespread in both terrestrial and aquatic environments [5,6]. Out of thousands of bioactive molecules, also known as secondary metabolites since they are not essential for…
Role of genetic polymorphisms in myocardial infarction at young age
2010
Acute myocardial infarction (AMI) in young adult presents a typical pattern of risk factors, clinical, angiographic and prognostic characteristics. In the last years we demonstrated that hemorheological profile is altered in these patients in a persistent way and independently of the number of risk factors and of the extent of coronary lesions. Thus, the hyperviscosity syndrome following AMI could be considered an intrinsic characteristic of these patients. Consequently it is possible to hypothesise the presence of a genetic background at the origin of this predisposition. If this background is able to influence the risk of ischemic heart disease, this should be particularly evident in youn…