Search results for "Phosphatidylethanol"
showing 10 items of 56 documents
Phospholipid-polyaspartamide micelles for pulmonary delivery of corticosteroids
2011
A novel drug delivery system for beclomethasone dipropionate (BDP) has been constructed through self-assembly of a pegylated phospholipid-polyaminoacid conjugate. This copolymer was obtained by chemical reaction of α,β-poly(N-2-hydroxyethyl)-DL-aspartamide (PHEA) with 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[amino(polyethyleneglycol)2000] (DSPE-PEG(2000)-NH(2)). Benefiting from the amphiphilic structure with the hydrophilic shell based on both PHEA and PEG and many hydrophobic stearoyl tails, PHEA-PEG(2000)-DSPE copolymer was able to self assemble into micelles in aqueous media above a concentration of 1.23 × 10(-7)M, determined by fluorescence studies. During the self-assembling …
Liver fatty acid composition in the spontaneously diabetic BB rat.
1991
The purpose of the present experiment was to investigate if the modulation by insulin of liver microsomal desaturase activities in the spontaneously diabetic adult male Bio-Breeding (BB) rat, with destructive insulitis resembling the lesions described in the human Type I (insulin-dependent) diabetes, corresponds to modifications in fatty acid composition, reflect of changes in fatty acid desaturation. We observed no significant differences between BB rats, during the hyper-(48 h), the normo-(17 h) and the hypo-glycemic (3 h) periods which followed the insulin injection, and control rats for the fatty acid composition of liver total lipids, phosphatidylethanolamines, phosphatidylcholines, tr…
RAB3GAP1 and RAB3GAP2 modulate basal and rapamycin-induced autophagy
2014
Macroautophagy is a degradative pathway that sequesters and transports cytosolic cargo in autophagosomes to lysosomes, and its deterioration affects intracellular proteostasis. Membrane dynamics accompanying autophagy are mostly elusive and depend on trafficking processes. RAB GTPase activating proteins (RABGAPs) are important factors for the coordination of cellular vesicle transport systems, and several TBC (TRE2-BUB2-CDC16) domain-containing RABGAPs are associated with autophagy. Employing C. elegans and human primary fibroblasts, we show that RAB3GAP1 and RAB3GAP2, which are components of the TBC domain-free RAB3GAP complex, influence protein aggregation and affect autophagy at basal an…
High-performance liquid chromatographic study of the regulation of phospholipid metabolism in cultured adrenocortical cells
1994
Abstract A rapid high-performance liquid chromatographic (HPLC) method for the separation of phospholipids was developed for minute samples of total lipids (ca. 200 μg). The method was applied to the study of the phospholipid metabolism in adrenocortical cell cultures. A complete separation of the different cellular phospholipid classes was achieved in 40 min. Good resolution of the phospholipid peaks was obtained, which allowed the collection of each individual class of phospholipids for further analysis of radioactivity and fatty acid composition by gas chromatography. When cells were incubated with [U-14C]glycerol or [U-14C]palmitate the bulk of the radioactivity was found in cellular ph…
Phospholipid distribution in the cytoplasmic membrane of Gram-negative bacteria is highly asymmetric, dynamic, and cell shape-dependent
2020
The cell shape of Gram-negative bacteria is maintained metabolically by asymmetric lipid distribution in biogenic plasma membrane.
Inhibition of astroglial cell proliferation by alcohols: interference with the protein kinase C-phospholipase D signaling pathway.
2000
Abstract Ethanol inhibits astroglial cell proliferation, an effect that may contribute to the development of alcoholic embryopathy in humans. In the present study, we investigated inhibitory effects of ethanol and butanol isomers (1-, 2- and t -butanol) on astroglial cell proliferation induced by the strongly mitogenic phorbol ester, 4s-phorbol-12α,13s-dibutyrate (PDB). 4s-Phorbol-12α,13s-dibutyrate (PDB) induced a 10-fold increase of [3H]thymidine incorporation in cortical astrocytes prepared from newborn rats (EC 50 : 70 nM) which was blocked by Ro 31-8220, a cell-permeable protein kinase C (PKC) inhibitor. Ethanol blocked PDB-induced astroglial proliferation in a concentration-dependent …
Identification of a putative membrane-inserted segment in the alpha-toxin of Staphylococcus aureus.
1994
To gain a fuller understanding of the regions of the Staphylococcus aureus alpha-toxin important in pore formation, we have used Forster dipole-dipole energy transfer to demonstrate that a central glycine-rich region of alpha-toxin (the so-called "hinge" region) inserts deeply into the bilayer on association of toxin with liposomes. Mutant alpha-toxins with unique cysteine (C) residues at positions 69 and 130 [Palmer, M., et al. (1993) J. Biol. Chem. 268, 11959) were reacted with the C-specific fluorophore acrylodan, which acted as an energy donor. The chosen acceptor was N-(7-nitrobenz-2-oxa-13- diazol-4-yl)-1,2-bis(hexadecanoyl)-sn-glycero-3-phosphoethanolamin e (NBD-PE). Measurement of t…
The influence of phase transitions in phosphatidylethanolamine models on the activity of violaxanthin de-epoxidase
2008
In the present study, the influence of the phospholipid phase state on the activity of the xanthophyll cycle enzyme violaxanthin de-epoxidase (VDE) was analyzed using different phosphatidylethanolamine species as model lipids. By using (31)P NMR spectroscopy, differential scanning calorimetry and temperature dependent enzyme assays, VDE activity could directly be related to the lipid structures the protein is associated with. Our results show that the gel (L beta) to liquid-crystalline (L alpha) phase transition in these single lipid component systems strongly enhances both the solubilization of the xanthophyll cycle pigment violaxanthin in the membrane and the activity of the VDE. This pha…
Lipidomic profiling identifies signatures of metabolic risk
2020
Background: Metabolic syndrome (MetS), the clustering of metabolic risk factors, is associated with cardiovascular disease risk. We sought to determine if dysregulation of the lipidome may contribute to metabolic risk factors. Methods: We measured 154 circulating lipid species in 658 participants from the Framingham Heart Study (FHS) using liquid chromatography-tandem mass spectrometry and tested for associations with obesity, dysglycemia, and dyslipidemia. Independent external validation was sought in three independent cohorts. Follow-up data from the FHS were used to test for lipid metabolites associated with longitudinal changes in metabolic risk factors. Results: Thirty-nine lipids were…
Stool Phospholipid Signature is Altered by Diet and Tumors
2014
Intake of saturated fat is a risk factor for ulcerative colitis (UC) and colon cancer. Changes in the microbiota have been implicated in the development of UC and colon cancer. The host and the microbiota generate metabolites that may contribute to or reflect disease pathogenesis. We used lipid class specific quantitative mass spectrometry to assess the phospholipid (PL) profile (phosphatidylcholine [PC], phosphatidylethanolamine [PE], phosphatidylinositol [PI], phosphatidylserine [PS]) of stool from mice fed a high fat (HFD) or control diet with or without induction of colitis-associated tumors using azoxymethane and dextran sodium sulfate. The microbiota was assessed using qPCR for severa…