Search results for "Scavenger"
showing 10 items of 129 documents
CD36 as a lipid sensor
2011
International audience; CD36 is a multifunctional protein homologous to the class B scavenger receptor SR-B1 mainly found in tissues with a sustained lipid metabolism and in several hematopoieic cells. CD36 is thought to be involved in various physiological and pathological processes like angiogenesis, thrombosis, atherogenesis, Alzheimer's disease or malaria. An additive emerging function for CD36 is a role as a lipid sensor. Location of CD36 and orthologue molecules in plasma membrane of cells in contact with the external environment (e.g. gustatory, intestinal or olfactory epithelia) allows the binding of exogenous-derived ligands including dietary lipids, diglycerides from bacterial wal…
Macrophage-Specific Lipid-Based Nanoparticles Improve Cardiac Magnetic Resonance Detection and Characterization of Human Atherosclerosis
2009
ObjectivesWe sought to determine whether gadolinium (Gd)-containing lipid-based nanoparticles (NPs) targeting the macrophage scavenger receptor-B (CD36) improve cardiac magnetic resonance (CMR) detection and characterization of human atherosclerosis.BackgroundGd-containing lipid-based NPs targeting macrophages have improved MR detection of murine atherosclerosis.MethodsGadolinium-containing untargeted NPs, anti-CD36 NPs, and nonspecific Fc-NPs were created. Macrophages were incubated with fluorescent targeted and nontargeted NPs to determine uptake via confocal microscopy and inductively coupled plasma mass spectroscopy (ICP-MS) quantified Gd uptake. Human aortic specimens were harvested at…
Impact of Glutathione Peroxidase-1 Deficiency on Macrophage Foam Cell Formation and Proliferation: Implications for Atherogenesis
2013
Clinical and experimental evidence suggests a protective role for the antioxidant enzyme glutathione peroxidase-1 (GPx-1) in the atherogenic process. GPx-1 deficiency accelerates atherosclerosis and increases lesion cellularity in ApoE(-/-) mice. However, the distribution of GPx-1 within the atherosclerotic lesion as well as the mechanisms leading to increased macrophage numbers in lesions is still unknown. Accordingly, the aims of the present study were (1) to analyze which cells express GPx-1 within atherosclerotic lesions and (2) to determine whether a lack of GPx-1 affects macrophage foam cell formation and cellular proliferation. Both in situ-hybridization and immunohistochemistry of l…
Induction of CD36 and thrombospondin-1 in macrophages by hypoxia-inducible factor 1 and its relevance in the inflammatory process.
2012
Inflammation is part of a complex biological response of vascular tissue to pathogens or damaged cells. First inflammatory cells attempt to remove the injurious stimuli and this is followed by a healing process mediated principally by phagocytosis of senescent cells. Hypoxia and p38-MAPK are associated with inflammation, and hypoxia inducible factor 1 (HIF-1) has been detected in inflamed tissues. We aimed to analyse the role of p38-MAPK and HIF-1 in the transcriptional regulation of CD36, a class B scavenger receptor, and its ligand thrombospondin (TSP-1) in macrophages and to evaluate the involvement of this pathway in phagocytosis of apoptotic neutrophils. We have also assessed HIF-1α, p…
Upregulation of liver VLDL receptor and FAT/CD36 expressions in LDLR-/- apoB100/100 mice fed trans-10,cis-12 conjugated linoleic acid
2006
International audience; This study explores the mechanisms responsible for the fatty liver setup in mice fed trans-10,cis-12 conjugated linoleic acid (t10c12 CLA), hypothesizing that an induction of low density lipoprotein receptor (LDLR) expression is associated with lipid accumulation. To this end, the effects of t10c12 CLA treatment on lipid parameters, serum lipoproteins, and expression of liver lipid receptors were measured in LDLR(-/-) apoB(100/100) mice as a model of human familial hypercholesterolemia itself depleted of LDLR. Mice were fed t10c12 CLA over 2 or 4 weeks. We first observed that the treatment induced liver steatosis, even in the absence of LDLR. Mice treated for 2 weeks…
Effects of glycation of the model food allergen ovalbumin on antigen uptake and presentation by human dendritic cells.
2010
Advanced glycation endproducts (AGEs) of food proteins resulting from the Maillard reaction after cooking or heating may have particular importance in food allergy. The underlying immunological mechanisms are only poorly understood. The aim of the study was to examine the effects of AGE derived from the model food allergen ovalbumin (AGE-OVA) on dendritic cells (DCs), their immunostimulatory capacity and the T-cell response compared with regular OVA. For this purpose, human immature DCs were exposed to fluorescein isothiocyanate (FITC)-labelled AGE-OVA and FITC-labelled regular OVA and uptake was analysed by flow cytometry and fluorescence microscopy. Furthermore, autologous CD4(+) T-cell p…
Nitric Oxide-Scavenging Properties of Some Chalcone Derivatives
2002
Abstract The implication of NO in many inflammatory diseases has been well documented. We have previously reported that some chalcone derivatives can control the iNOS pathway in inflammatory processes. In the present study, we have assessed the NO-scavenging capacity of three chalcone derivatives (CH8, CH11, and CH12) in a competitive assay with HbO2, a well-known physiologically relevant NO scavenger. Our data identify these chalcones as new NO scavengers. The estimated second-order rate constants (ks) for the reaction of the three derivatives with NO is in the same range as the value obtained for HbO2, with CH11 exerting the greatest effect. These results suggest an additional action of t…
First report of the scavenging isopod Natatolana neglecta (Crustacea: Isopoda: Cirolanidae) feeding on a sea turtle
2019
A juvenile male loggerhead sea turtle (Caretta caretta) was found dead in April 2015, entangled in a trammel net on the Mediterranean coast of Spain. Post-mortem examination revealed the presence of ninety-five isopods dispersed in the coelomic cavity, and inside the oesophagus and skull. All individuals found scavenging on the sea turtle were identified as Natatolana neglecta (Hansen, 1890) (Isopoda: Cirolanidae). Genetic analysis of the isopod gut contents showed that they were feeding on turtle tissue, confirming that N. neglecta can also attack dead sea turtles. This study shows the value of cirolanids as potential indicators of the cause of death in stranded sea turtles.
Anandamide-induced apoptosis in Chang liver cells involves ceramide and JNK/AP-1 pathway
2006
In the present study we demonstrate that anandamide, the most important endogenous cannabinoid, markedly induced apoptosis in Chang liver cells, an immortalized non-tumor cell line derived from normal liver tissue, while it induced only modest effects in a number of hepatoma cell lines. The apoptotic effect was reduced by methyl-beta-cyclodextrin, a membrane cholesterol depletor, suggesting an interaction between anandamide and the membrane microdomains named lipid rafts. Anandamide effects were mediated by the production of ceramide, as demonstrated by experiments performed with the sphingomyelinase inhibitor, desipramine, or with the sphingomyelinase activator, melittin. This conclusion w…
Synthesis and pharmacological evaluation of 2'-hydroxychalcones and flavones as inhibitors of inflammatory mediators generation.
1995
2'-Hydroxy-3,4-dimethoxy-3',4'-dimethylchalcone (3a), 2'-hydroxy-3',4',3,4-tetramethoxychalcone (3b), and their corresponding flavones, 3',4'-dimethoxy-7,8-dimethylflavone (4a) and 3',4',7,8-tetramethoxyflavone (4b), were prepared from 3,4-dimethoxycinnamic acid and the respective phenol. The four compounds inhibited enzymic lipid peroxidation and showed weak peroxyl scavenging activity. They also reduced LTB 4 release from human neutrophils stimulated by A23187. The chalcone 3b was the only compound able to inhibit in a concentration-dependent way, synovial human recombinant phospholipase A 2 activity, human platelet TXB 2 generation, and human neutrophil degranulation. This chalcone exert…