Search results for "acids"
showing 10 items of 3520 documents
Prostaglandin E2 regulates inducible nitric oxide synthase in the murine macrophage cell line J774.
1995
We have evaluated the role of prostaglandin E2 (PGE2) in the synthesis of nitric oxide (NO) by the activation of the inducible form of nitric oxide synthase (NOS) in the murine macrophage cell line, J774, stimulated with different doses of lipopolysaccharide (LPS). The stimulation of the J774 line with suboptimal doses of LPS (0.1 microgram/mL) caused a production of endogenous PGE2 that was capable of stimulating NOS activity inducing an increase in the NO synthesis, as attested by the fact that cyclooxygenase enzyme inhibitor, indomethacin, significantly reduced NO secretion. On the contrary, a higher dose of LPS (1 microgram/mL) produced high levels of PGE2 that reduced the levels of NOS…
Anandamide inhibits IL-12p40 production by acting on the promoter repressor element GA-12: Possible involvement of the COX-2 metabolite prostamide E 2
2007
The eCB [endoCB (cannabinoid)] system is being considered as a novel therapeutic target for immune disorders. Cytokines of the IL-12 (interleukin-12) family have essential functions in cell-mediated immunity. In the present study, we have addressed the mechanisms of action of the eCB AEA (anandamide) on the regulation of IL-12p40 in activated microglia/macrophages. We demonstrated that AEA can inhibit the expression of p35, p19 and p40 subunits, which form the biologically-active cytokines IL-12 and IL-23 in microglia stimulated with LPS (lipopolysaccharide)/IFNγ (interferon γ). Additionally, we have provided evidence that AEA reduces the transcriptional activity of the IL-12p40 gene in LPS…
Mice Expressing Only Covalent Dimeric Heparin Binding-deficient Lipoprotein Lipase
2004
Lipoprotein lipase (LpL) hydrolyzes triglycerides of circulating lipoproteins while bound as homodimers to endothelial cell surface heparan sulfate proteoglycans. This primarily occurs in the capillary beds of muscle and adipose tissue. By creating a mouse line that expresses covalent dimers of heparin-binding deficient LpL (hLpLHBM-Dimer) in muscle, we confirmed in vivo that linking two LpL monomers in a head to tail configuration creates a functional LpL. The hLpLHBM-Dimer transgene produced abundant activity and protein in muscle, and the LpL was the expected size of a dimer (approximately 110 kDa). Unlike the heparin-binding mutant monomer, hLpLHBM-Dimer had the same stability as nonmut…
A New Look at Novel Cardiovascular Risk Biomarkers: The Role of Atherogenic Lipoproteins and Innovative Antidiabetic Therapies.
2022
The presence of residual cardiovascular disease (CVD) risk is a current dilemma in clinical practice; indeed, despite optimal management and treatment, a considerable proportion of patients still undergo major CV events. Novel lipoprotein biomarkers are suggested as possible targets for improving the outcomes of patients at higher risk for CVD, and their impact on major CV events and mortality have previously been investigated. Innovative antidiabetic therapies have recently shown a significant reduction in atherogenic lipoproteins, beyond their effects on glucose parameters; it has also been suggested that such anti-atherogenic effect may represent a valuable mechanistic explanation for th…
Geometric and thermodynamic considerations about the lipid vesicles formation in water (I. Unilamellar vesicles)
2001
Abstract A parametrization based on the differential geometry and on the thermodynamics of dispersed systems has been developed in order to explain the processes leading to the formation of lipid vesicles in water. Several factors of known importance such as aqueous interlayer, chain-length, lipid chain-packing and membrane asymmetry, as well as the existence of two different surfaces in the vesicular bilayer have been considered. The barrier which amphiphile molecules need to surpass in order to the vesicle be formed has three contributions related to the surface energy, the mechanical energy due to overpressure and the excess of chemical potential. The theoretical results define the condi…
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…
Nanoparticle structure development in the gastro‐intestinal model fluid FaSSIF mod6.5 from several phospholipids at various water content relevant fo…
2014
The characteristics of intestinal model fluids were investigated at conditions, which simulate the passage from the middle to the end of the duodenum. The formation and decay of liposomes and micelles in model bile fluids were studied, because of their role as an intermediate host for the resolution and uptake of hydrophobic drugs (BCS classes II, IV). The conditions, which may influence the formation of these nanoparticulate intermediates were studied, i.e., the lipid composition of the bile, the preparation method, the time of the passage through the modelled duodenum segment and the concentration, which results from the variable dilution of the bile by mixing with the transfer medium rep…
Preparation of large unilamellar vesicles
1982
Single (unilamellar) and oligolamellar lipid bilayer vesicles of large diameter have great potential in membrane research. In particular, large unilamellar bilayer vesicles (diam. >50 m) would permit the insertion of microelectrodes for the measurement of the electrical properties of lipid bilayer membranes of different compositions. Furthermore, vesicles large enough to be observed by light microscopy could be fused with cells with the aid of the electric field method [l-4]. Since vesicles (liposomes) can be loaded with macromolecules, this might be an elegant means of transferring proteins or plasmids into cells. Large vesicles with different lipid compositions and only one unit membrane …
Polymeric Monolayers and Liposomes as Models for Biomembranes and Cells
1984
Conventional model membrane systems based on natural lipids usually lack long term stability. Polymer chemistry can help to overcome this disadvantage introducing polymerizable lipids into these systems. Polymerizable lipids used are diacetylenes, butadienes, acrylates or lipids which can undergo polycondensation.
Macromolecules in ordered media: 7. Influence of ionic strength and bilayer composition on the association of polyelectrolytes to mixed liposomes
1997
The effect of both the phospholipid composition of the bilayer and the ionic strength of the medium on the association between poly(2-vinyl pyridine) and mixed liposomes based on dimyristoyl phosphatidic acid and dimyristoyl phosphatidil choline was investigated using fluorescence spectroscopy. Intensity changes upon addition of vesicles have allowed us to estimate the extent of the association and data have been processed as association isotherms. We found that the association is enhanced by increasing both the ionic strength and the anionic phospholipid fraction. However, whereas the negative net charge of the bilayer strongly enhances the interaction, the presence of more and more electr…