Search results for "Phosphatidic acid"

NT-3 protein levels are enhanced in the hippocampus of PRG1-deficient mice but remain unchanged in PRG1/LPA2 double mutants

2015

The plasticity-related gene 1 (PRG1) modulates bioactive lipids at the postsynaptic density and is a novel player in neuronal plasticity and regulation of glutamatergic transmission at principal neurons. PRG1, a neuronal molecule, is highly expressed during development and regeneration processes at the postsynaptic density, modulates synaptic lysophosphatidic acid (LPA) levels and is related to epilepsy and brain injury. In the present study, we analyzed the interaction between the synaptic molecules PRG1 and LPA2R with other plasticity-related molecules the neurotrophins. The protein levels of NGF, BDNF and NT-3 were measured using ELISA in hippocampal tissue of homozygous (PRG(-/-)) and h…

Endurance Training Counteracts the High-Fat Diet-Induced Profiling Changes of ω-3 Polyunsaturated Fatty Acids in Skeletal Muscle of Middle-Aged Rats.

2019

Purpose To investigate the effects of endurance training on the content of ω-3 polyunsaturated fatty acids (PUFAs) and their distribution among lipid classes in skeletal muscle in middle aged, high-fat diet fed rats. Method Thirty 10-month old male Sprague Dawley (SD) rats were assigned to four groups. Two groups of rats remained sedentary and were fed chow diet (C group), or high-fat diet (H group), respectively. The other two groups of rats were subjected to endurance training while maintaining their chow diet (EC group), or high-fat diet (EH group). After 16 weeks endurance training and/or diet intervention, the content of ω-3 PUFAs and ω-3 PUFA-containing lipids in rat soleus muscle wer…

Plasma and fibroblasts of Tangier disease patients are disturbed in transferring phospholipids onto apolipoprotein A-I

1998

Plasmas of patients with Tangier disease (TD) lack lipid-rich α-HDL which, in normal plasma, constitutes the majority of high density lipoprotein (HDL). Residual amounts of apolipoprotein (apo)A-I in TD plasma occur as lipid-poor or even lipid-free preβ-HDL. By contrast to normal plasma, TD plasma does not convert preβ-HDL into α-HDL. Moreover, fibroblasts of TD patients were found to be defective in secreting cholesterol or phospholipids in the presence of lipid-free apoA-I. We have therefore hypothesized that both defective conversion of preβ-HDL into α-HDL and defective lipid efflux from TD cells onto lipid-free apoA-I result from a disturbance in phospholipid transfer occurring in both …

Glutamate Activates Phospholipase D in Hippocampal Slices of Newborn and Adult Rats

1993

Phospholipase D (PLD) is activated by many neurotransmitters in a novel signal transduction pathway. In the present work, PLD activity was studied comparatively in hippocampal slices of newborn and adult rats. Basal PLD activity in adult rats was almost three times higher than in newborn rats. In newborn rats, L-glutamate and 1S,3R-1-aminocyclopentane-1,3-dicarboxylic acid (1S,3R-ACPD) time- and concentration-dependently enhanced the formation of [3H]phosphatidylpropanol ([3H]PP) and of [3H]phosphatidic acid in the presence of 2% propanol. N-Methyl-D-aspartate and kainate (both 1 mM) caused small, but significant increases (approximately 50%), whereas alpha-amino-3-hydroxy-5-methylisoxazole…

Ionotrophic 5-hydroxytryptamine type 3 receptor activates the protein kinase C-dependent phospholipase D pathway in human T-cells

1999

The present study was undertaken to investigate the role of the 5-hydroxytryptamine (5-HT) ionotrophic receptor 5-HT3 in the activation of human Jurkat T-cells. 5-HT and 2-methyl-5-HT (2Me-5-HT), an agonist of the 5-HT3 receptor, induced increases in intracellular free Na+ concentrations, [Na+]i, via opening of the ionotrophic receptor in these cells. These two serotonergic (5-hydroxytryptaminergic) agents potentiated phytohaemagglutinin (PHA)-induced T-cell activation. However, they failed to potentiate dioctanoglycerol-plus-ionomycin-stimulated T-cell blastogenesis. Interestingly, an inhibitor of protein kinase C (PKC), GF 109203X, curtailed significantly 5-HT and 2Me-5-HT-potentiated T-c…

Thermodynamic Study of Small Hydrophobic Ions at the Water–Lipid Interface

2001

Abstract The thermodynamics of binding of two small hydrophobic ions such as norharman and tryptophan to neutral and negatively charged small unilamellar vesicles was investigated at pH 7.4 using fluorescence spectroscopy. Vesicles were formed at room temperature from dimyristoyl phosphatidylcholine (DMPC) or DMPC/dimyristoylphosphatidic acid and DMPC/dimyristoylphosphatidylglycerol. The changes in fluorescence properties were used to obtain association isotherms at variable membrane surface negative charge and at different ionic strengths. The binding of both ions was found to be quantitatively enhanced as the percentage of negative phospholipid increases in the membrane. Also, a decrease …

Giant liposomes as model membranes for immunological studies: spontaneous insertion of purified K1-antigen (poly-alpha-2,8-NeuAc) of Escherichia coli.

1990

A flow chamber has been constructed to use giant liposomes (diameter 5-50 microns) as model membranes for immunological studies and other experiments involving the interaction with water-soluble compounds. As an example of immunological importance, the insertion of purified K-antigen from Escherichia coli K1 has been studied. Despite its large hydrophilic part (poly-alpha-2,8-NeuAc), which is capped at its potential reducing end with phosphatidic acid acting as a lipid anchor group, this water-soluble material is readily incorporated into liposomal membranes of dimyristoylphosphatidylcholine (DMPC). The incorporation has been proven by immunofluorescence using a FITC-labeled monoclonal anti…

Mitogenic effects of phospholipase D and phosphatidic acid in transiently permeabilized astrocytes: effects of ethanol.

2003

Investigations of lipid-mediated signalling pathways are often limited by a lack of methods for the intracellular delivery of lipid messengers. We established a procedure for the transient permeabilization of astrocytes by an oxygen-insensitive mutant of streptolysin-O (SLO) to investigate the participation of the phospholipase D (PLD) signalling pathway in astroglial cell proliferation. Exogenous PLD, when incubated in the presence of SLO, caused an increase in DNA synthesis (measured by thymidine incorporation) which was completely suppressed by ethanol (0.3%, v/v). In parallel experiments, phosphatidic acid also induced a dose-dependent mitogenic response which, however, was not affected…

Molecular organization via ionic interactions at interfaces. 1. Monolayers and LB films of cyclic bisbipyridinium tetracations and dimyristoylphospha…

1993

Cross-talk between phosphatidic acid and ceramide during ethanol-induced apoptosis in astrocytes

2005

Background Ethanol inhibits proliferation in astrocytes, an effect that was recently linked to the suppression of phosphatidic acid (PA) formation by phospholipase D (PLD). The present study investigates ethanol's effect on the induction of apoptosis in astrocytes and the formation of ceramide, an apoptotic signal. Evidence is presented that the formation of PA and ceramide may be reciprocally linked during ethanol exposure. Results In cultured rat cortical astrocytes, ethanol (0.3–1 %, v/v) induced nuclear fragmentation and DNA laddering indicative of apoptosis. Concomitantly, in cells prelabeled with [3H]-serine, ethanol caused a dose-dependent, biphasic increase of the [3H]-ceramide/ [3H…