Inactivation of NPC1L1 causes multiple lipid transport defects and protects against diet-induced hypercholesterolemia.
AuthorsDavies JP, Scott C, Oishi K, Liapis A, Ioannou YA
JournalJ Biol Chem
PubMed ID15671032
'NPC1L1, a recently identified relative of Niemann-Pick C1, was characterized to determine its subcellular location and potential function(s). NPC1L1 was highly expressed in HepG2 cells and localized in a subcellular vesicular compartment rich in the small GTPase Rab5. mRNA expression profiling revealed significant differences between mouse and man with highest ... More
High density lipoprotein-mediated cholesterol uptake and targeting to lipid droplets in intact L-cell fibroblasts. A single- and multiphoton fluorescence approach.
AuthorsFrolov A, Petrescu A, Atshaves BP, So PT, Gratton E, Serrero G, Schroeder F
JournalJ Biol Chem
PubMed ID10777574
'Fluorescent sterols, dehydroergosterol and NBD-cholesterol, were used to examine high density lipoprotein-mediated cholesterol uptake and intracellular targeting in L-cell fibroblasts. The uptake, but not esterification or targeting to lipid droplets, of these sterols differed >100-fold, suggesting significant differences in uptake pathways. NBD-cholesterol uptake kinetics and lipoprotein specificity reflected high density ... More
Lipid binding to sterol carrier protein-2 is inhibited by ethanol.
AuthorsAvdulov NA, Chochina SV, Igbavboa U, Warden CS, Schroeder F, Wood WG
JournalBiochim Biophys Acta
PubMed ID9931423
'Sterol carrier protein-2 (SCP-2) is an intracellular lipid carrier protein that binds cholesterol, phospholipids, fatty acids and other ligands. It has been reported that expression of SCP-2 was increased in brain nerve endings or synaptosomes of chronic ethanol-treated mice and it was shown that cholesterol homeostasis was altered in brain ... More
Formation of membrane domains created during the budding of vesicular stomatitis virus. A model for selective lipid and protein sorting in biological membranes.
AuthorsLuan P, Yang L, Glaser M
JournalBiochemistry
PubMed ID7543280
'Vesicular stomatitis virus buds from domains of the plasma membrane that have a unique protein and lipid composition. Fluorescence digital imaging microscopy and resonance energy transfer were used to determine how the two viral envelope-associated proteins, the G and the M proteins, could alter the lateral distribution of lipids in ... More
Membrane properties of D-erythro-N-acyl sphingomyelins and their corresponding dihydro species.
AuthorsKuikka M, Ramstedt B, Ohvo-Rekilä H, Tuuf J, Slotte JP
JournalBiophys J
PubMed ID11325733
'We have prepared acyl chain-defined D-erythro-sphingomyelins and D-erythro-dihydrosphingomyelins and compared their properties in monolayer and bilayer membranes. Surface pressure/molecular area isotherms of D-erythro-N-16:0-sphingomyelin (16:0-SM) and D-erythro-N-16:0-dihydrosphingomyelin (16:0-DHSM) show very similar packing properties, except that the expanded-to-condensed phase transition (crystallization) occurs at a lower surface pressure for 16:0-DHSM. The measured surface ... More
Lipid binding to amyloid beta-peptide aggregates: preferential binding of cholesterol as compared with phosphatidylcholine and fatty acids.
AuthorsAvdulov NA, Chochina SV, Igbavboa U, Warden CS, Vassiliev AV, Wood WG
JournalJ Neurochem
PubMed ID9326304
'Amyloid beta-peptide (A beta) aggregates are one of the key neuropathological characteristics of Alzheimer''s disease. A beta belongs to a group of proteins that aggregate and form beta-sheets, and some of these proteins bind cholesterol and other lipids. The purpose of the experiments reported here was to determine if cholesterol, ... More
Cholesterol distribution in the Golgi complex of DITNC1 astrocytes is differentially altered by fresh and aged amyloid beta-peptide-(1-42).
AuthorsIgbavboa U, Pidcock JM, Johnson LN, Malo TM, Studniski AE, Yu S, Sun GY, Wood WG
JournalJ Biol Chem
PubMed ID12584199
'The Golgi complex plays an important role in cholesterol trafficking in cells, and amyloid beta-peptides (Abetas) alter cholesterol trafficking. The hypothesis was tested that fresh and aged Abeta-(1-42) would differentially modify Golgi cholesterol content in DINTC1 astrocytes and that the effects of Abeta-(1-42) would be associated with the region of ... More
The membrane-permeabilizing effect of avenacin A-1 involves the reorganization of bilayer cholesterol.
AuthorsArmah CN, Mackie AR, Roy C, Price K, Osbourn AE, Bowyer P, Ladha S
JournalBiophys J
PubMed ID9876141
'Avenacin A-1 is a member of a group of naturally occurring compounds called saponins. It is found in oat plants, where it protects against fungal pathogens. A combined electrical and optical chamber was used to determine the interaction of avenacin A-1 with Montal-Mueller planar lipid bilayers. This system allowed simultaneous ... More
Dehydroergosterol structural organization in aqueous medium and in a model system of membranes.
AuthorsLoura LM, Prieto M
JournalBiophys J
PubMed ID9129825
'The aggregation of delta 5,7,9(11),22-ergostatetraen-3 beta-ol (dehydroergosterol or DHE), a fluorescent analog of cholesterol, was studied by photophysical techniques. It was concluded that the aqueous dispersions of DHE consist of strongly fluorescent microcrystals, and no evidence for self-quenching in micellar-type aggregates was found. The organization of DHE in model systems ... More
Evidence for a Trypanosoma brucei lipoprotein scavenger receptor.
AuthorsGreen HP, Del Pilar Molina Portela M, St Jean EN, Lugli EB, Raper J
JournalJ Biol Chem
PubMed ID12401813
'African trypanosomes are lipid auxotrophs that live in the bloodstream of their human and animal hosts. Trypanosomes require lipoproteins in addition to other serum components in order to multiply under axenic culture conditions. Delipidation of the lipoproteins abrogates their capacity to support trypanosome growth. Both major classes of serum lipoproteins, ... More
Steroidogenic acute regulatory protein binds cholesterol and modulates mitochondrial membrane sterol domain dynamics.
AuthorsPetrescu AD, Gallegos AM, Okamura Y, Strauss JF, Schroeder F
JournalJ Biol Chem
PubMed ID11489878
'The steroidogenic acute regulatory protein (StAR) mediates the rate-limiting step of steroidogenesis, delivery of cholesterol to the inner mitochondrial membrane. However, the mechanism whereby cholesterol translocation is accomplished has not been resolved. Recombinant StAR proteins lacking the first N-terminal 62 amino acids comprising the mitochondrial-targeting sequence were used to determine ... More
Cholesterol organization in membranes at low concentrations: effects of curvature stress and membrane thickness.
AuthorsRukmini R, Rawat SS, Biswas SC, Chattopadhyay A
JournalBiophys J
PubMed ID11566783
'Cholesterol is often found distributed nonrandomly in domains in biological and model membranes and has been reported to be distributed heterogeneously among various intracellular membranes. Although a large body of literature exists on the organization of cholesterol in plasma membranes or membranes with high cholesterol content, very little is known ... More
Sequestration of acetylated LDL and cholesterol crystals by human monocyte-derived macrophages.
AuthorsKruth HS, Skarlatos SI, Lilly K, Chang J, Ifrim I
JournalJ Cell Biol
PubMed ID7698980
'Monocyte-derived macrophages accumulate and process cholesterol in atherosclerotic lesions. Because of the importance of this process, we examined the interaction of cholesterol crystals and acetylated low density lipoprotein (AcLDL) with human monocyte-macrophages in a combined chemical and morphological study. These two forms of cholesterol induced extensive compartmentalization of the macrophage ... More
Fluorescent lipid uptake and transport in adult Schistosoma mansoni.
AuthorsMoffat D, Kusel JR
JournalParasitology
PubMed ID1437279
'Fluorescent lipophilic compounds can be used to label the surface membrane of Schistosoma mansoni by adding the compound in small amounts of organic solvents to aqueous medium in vitro. Under these conditions it is difficult to follow routes of distribution of the label. Here we have absorbed nitrobenzoxadiazolamine methylamino-(NBD)-ceramides to ... More
Cholesterol redistribution within human platelet plasma membrane: evidence for a stimulus-dependent event.
'The fluorescent analog NBD-phosphatidylethanolamine and the analogs of cholesterol NBD-cholesterol and cholestatrienol were used to study the distribution of these lipids within the plasma membrane bilayer of human platelets. The probes were incorporated into platelets using phosphatidylcholine donor vesicles. The distribution of NBD lipid and of cholestatrienol in the platelet ... More
The mechanism of membrane insertion for a cholesterol-dependent cytolysin: a novel paradigm for pore-forming toxins.
AuthorsShatursky O, Heuck AP, Shepard LA, Rossjohn J, Parker MW, Johnson AE, Tweten RK
JournalCell
PubMed ID10555145
'Perfringolysin O (PFO), a water-soluble monomeric cytolysin secreted by pathogenic Clostridium perfringens, oligomerizes and forms large pores upon encountering cholesterol-containing membranes. Whereas all pore-forming bacterial toxins examined previously have been shown to penetrate the membrane using a single amphipathic beta hairpin per polypeptide, cysteine-scanning mutagenesis and multiple independent fluorescence techniques ... More
Annexin 2-caveolin 1 complex is a target of ezetimibe and regulates intestinal cholesterol transport.
AuthorsSmart EJ, De Rose RA, Farber SA
JournalProc Natl Acad Sci U S A
PubMed ID14985510
'Modulation of cholesterol absorption in the intestine, the primary site of dietary cholesterol uptake in humans, can have profound clinical implications. We have undertaken a reverse genetic approach by disrupting putative cholesterol processing genes in zebrafish larvae by using morpholino (MO) antisense oligonucleotides. By using targeted MO injections and immunoprecipitation ... More
Cholesterol binding does not predict activity of the steroidogenic acute regulatory protein, StAR.
AuthorsBaker BY, Epand RF, Epand RM, Miller WL,
JournalJ Biol Chem
PubMed ID17301050
'Steroidogenic acute regulatory protein (StAR) stimulates adrenal and gonadal steroidogenesis by increasing the influx of cholesterol into mitochondria, where it is converted to pregnenolone to initiate steroidogenesis. StAR acts on the outer mitochondrial membrane where each molecule stimulates the mitochondrial import of several hundred molecules of cholesterol, but the precise ... More
The signal sequence moves through a ribosomal tunnel into a noncytoplasmic aqueous environment at the ER membrane early in translocation.
AuthorsCrowley KS, Reinhart GD, Johnson AE
JournalCell
PubMed ID8513496
'The signal sequence is in an aqueous milieu at an early stage in the translocation of a nascent secretory protein across the endoplasmic reticulum membrane. This was determined using fluorescent probes incorporated into the signal sequence of fully assembled ribosome-nascent chain-membrane complexes: the fluorescence lifetimes revealed that the probes were ... More
Determination of time-dependent inositol-1,4,5-trisphosphate concentrations during calcium release in a smooth muscle cell.
AuthorsFink CC, Slepchenko B, Loew LM
JournalBiophys J
PubMed ID10388786
'The level of [InsP3]cyt required for calcium release in A7r5 cells, a smooth muscle cell line, was determined by a new set of procedures using quantitative confocal microscopy to measure release of InsP3 from cells microinjected with caged InsP3. From these experiments, the [InsP3]cyt required to evoke a half-maximal calcium ... More
The potential of fluorescent and spin-labeled steroid analogs to mimic natural cholesterol.
AuthorsScheidt HA, Muller P, Herrmann A, Huster D
JournalJ Biol Chem
PubMed ID12947110
'Cholesterol analogs are often used to investigate lipid trafficking and membrane organization of native cholesterol. Here, the potential of various spin (doxyl moiety) and fluorescent (7-nitrobenz-2-oxa-1,3-diazol-4-yl (NBD) group) labeled cholesterol analogs as well as of fluorescent cholestatrienol and the naturally occurring dehydroergosterol to mimic the unique properties of native cholesterol ... More
Genetic analysis of digestive physiology using fluorescent phospholipid reporters.
AuthorsFarber SA, Pack M, Ho SY, Johnson ID, Wagner DS, Dosch R, Mullins MC, Hendrickson HS, Hendrickson EK, Halpern ME
JournalScience
PubMed ID11359013
'Zebrafish are a valuable model for mammalian lipid metabolism; larvae process lipids similarly through the intestine and hepatobiliary system and respond to drugs that block cholesterol synthesis in humans. After ingestion of fluorescently quenched phospholipids, endogenous lipase activity and rapid transport of cleavage products results in intense gall bladder fluorescence. ... More
NBD-cholesterol incorporation by rat macrophages and lymphocytes: a process dependent on the activation state of the cells.
AuthorsPortioli Silva EP, Peres CM, Roberto Mendonça J, Curi R
JournalCell Biochem Funct
PubMed ID14695650
'The time-course of incorporation of NBD-cholesterol by macrophages (Ma) and lymphocytes (LY) obtained from untreated and thioglycollate-injected (thio) rats was investigated. NBD-cholesterol incorporation was also examined in Ma obtained from untreated rats and stimulated in vitro by lipopolysaccharide (LPS) and phorbol-myristate acetate (PMA). The same measurement was performed in LY ... More
Charge-based heterogeneity of human plasma lipoproteins at hypertriglyceridemia: capillary isotachophoresis study.
AuthorsDergunov AD, Hoy A, Smirnova EA, Visvikis S, Siest G
JournalInt J Biochem Cell Biol
PubMed ID12565713
'To reveal the metabolic links between and within pools of pro-atherogenic triglyceride(TG)-rich lipoproteins and anti-atherogenic high density lipoproteins (HDL), the changes in lipoprotein profile at hypertriglyceridemia were analyzed by capillary isotachophoresis. Plasma samples from patients with apoE3/3 phenotype were stained with a fluorescent probe NBD-C6-ceramide and lipoproteins resolved into six ... More
Digital imaging fluorescence microscopy.
AuthorsSmith LC, Benson DM, Gotto AM, Bryan J
JournalMethods Enzymol
PubMed ID3724557
Electric field-induced concentration gradients in planar supported bilayers.
AuthorsGroves JT, Boxer SG
JournalBiophys J
PubMed ID8580340
A simple method of generating electric field-induced concentration gradients in planar supported bilayers has been developed. Gradients of charged, fluorescently labeled probes were visualized by epifluorescence microscopy and could be observed at field strengths as low as 1 V/cm. Steady-state concentration gradients can be described by a simple competition between ... More
Identification of mosquito sterol carrier protein-2 inhibitors.
AuthorsKim MS, Wessely V, Lan Q
JournalJ Lipid Res
PubMed ID15627652
A mosquito sterol carrier protein-2, AeSCP-2, has been shown to aid in the uptake of cholesterol in mosquito cells. The discovery of chemical inhibitors of AeSCP-2 is reported here. AeSCP-2 inhibitors (SCPIs) belong to several chemotypes of hydrophobic compounds. Those inhibitors competed with cholesterol for AeSCP-2, binding with relatively high ... More
Cholesterol controls lipid endocytosis through Rab11.
AuthorsTakahashi M, Murate M, Fukuda M, Sato SB, Ohta A, Kobayashi T,
JournalMol Biol Cell
PubMed ID17475773
Cellular cholesterol increases when cells reach confluency in Chinese hamster ovary (CHO) cells. We examined the endocytosis of several lipid probes in subconfluent and confluent CHO cells. In subconfluent cells, fluorescent lipid probes including poly(ethylene glycol)derivatized cholesterol, 22-(N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino)-23,24-bisnor-5-cholen-3beta-ol, and fluorescent sphingomyelin analogs were internalized to pericentriolar recycling endosomes. This accumulation ... More
Exclusion of a cholesterol analog from the cholesterol-rich phase in model membranes.
AuthorsLoura LM, Fedorov A, Prieto M
JournalBiochim Biophys Acta
PubMed ID11286966
Vesicles of phosphatidylcholine/cholesterol mixtures show a wide composition range with coexistence of two fluid phases, the 'liquid disordered' (cholesterol-poor) and 'liquid ordered' (cholesterol-rich) phases. These systems have been widely used as models of membranes exhibiting lateral heterogeneity (membrane domains). The distributions of two fluorescent probes (a fluorescent cholesterol analog, NBD-cholesterol, ... More
Internalized plasma membrane cholesterol passes through an endosome compartment that is distinct from the acid vesicle-lysosome compartment.
AuthorsPorpaczy Z, Tomasek JJ, Freeman DA
JournalExp Cell Res
PubMed ID9260888
Cholesterol from the plasma membrane of MA-10 Leydig tumor cells is internalized into the cell and either esterified or used as substrate for steroid hormone synthesis. In the present studies we show that chloroquine and sphinganine cause LDL cholesterol and cholesteryl esters to accumulate in the cells. A lysosome fraction ... More
A novel fluorescence method to monitor the lysosomal disintegration of low density lipoprotein.
AuthorsOhashi M, Murata M, Ohnishi S
JournalEur J Cell Biol
PubMed ID1468435
A novel fluorescence method to monitor the lysosomal disintegration of low density lipoprotein (LDL) particles in living cells has been developed. The method is based on the fluorescence resonance energy transfer (RET) between two fluorescent molecules incorporated into LDL particles. NBD-cholesterol linoleate (NBD-CL) and octadecyl rhodamine B (R18) were incorporated ... More
Molecular diffusion in sperm plasma membranes during epididymal maturation.
AuthorsChristova Y, James P, Mackie A, Cooper TG, Jones R
JournalMol Cell Endocrinol
PubMed ID15109743
Fluorescence recovery after photobleaching (FRAP) analysis has been used to measure lipid diffusion in different regions of the sperm plasma membrane. Our goal has been to understand how some membrane components are confined to specific surface domains, whilst others are freely diffusing and in some cases are able to migrate ... More
A pH-dependent molten globule transition is required for activity of the steroidogenic acute regulatory protein, StAR.
AuthorsBaker BY, Yaworsky DC, Miller WL
JournalJ Biol Chem
PubMed ID16234239
The steroidogenic acute regulatory protein (StAR) simulates steroid biosynthesis by increasing the flow of cholesterol from the outer mitochondrial membrane (OMM) to the inner membrane. StAR acts exclusively on the OMM, and only StAR's carboxyl-terminal alpha-helix (C-helix) interacts with membranes. Biophysical studies have shown that StAR becomes a molten globule ... More
Lateral diffusion in substrate-supported lipid monolayers as a function of ambient relative humidity.
AuthorsBaumgart T, Offenhäusser A
JournalBiophys J
PubMed ID12202374
We analyzed the influence of water activity on the lateral self-diffusion of supported phospholipid monolayers. Lipid monolayer membranes were supported by polysaccharide cushions (chitosan and agarose), or glass. A simple diffusion model was derived, based on activated diffusion with an activation energy, E(a), which depends on the hydration state of ... More
Identification of ACAT1- and ACAT2-specific inhibitors using a novel, cell-based fluorescence assay: individual ACAT uniqueness.
AuthorsLada AT, Davis M, Kent C, Chapman J, Tomoda H, Omura S, Rudel LL
JournalJ Lipid Res
PubMed ID14617738
Acyl CoA:cholesterol acyltransferase 1 (ACAT1) and ACAT2 are enzymes responsible for the formation of cholesteryl esters in tissues. While both ACAT1 and ACAT2 are present in the liver and intestine, the cells containing either enzyme within these tissues are distinct, suggesting that ACAT1 and ACAT2 have separate functions. In this ... More
HDL-mediated cholesterol uptake and targeting to lipid droplets in adipocytes.
AuthorsDagher G, Donne N, Klein C, Ferre P, Dugail I
JournalJ Lipid Res
PubMed ID12867544
Adipocytes express high levels of the HDL scavenger receptor class B type I in a differentiation-dependent manner. We thus have analyzed the routes of HDL cholesterol trafficking at different phases of adipocyte differentiation in the 3T3-L1 cell line. One novel and salient feature of this paper is the observation of ... More
Uptake and cellular localization of exogenous lipids by Giardia lamblia, a primitive eukaryote.
AuthorsStevens TL, Gibson GR, Adam R, Maier J, Allison-Ennis M, Das S
JournalExp Parasitol
PubMed ID9207743
Giardia lamblia trophozoites are unable to carry out de novo lipid synthesis. It is therefore likely that lipids are acquired from the small intestine of the host, in which the trophozoites are exposed to free and conjugated fatty acids, various sterols, phospholipids, bile acids, and bile-lipid mixed micelles. Here we ... More
The obligate intracellular protozoan Toxoplasma gondii resides within a specialized parasitophorous vacuole (PV), isolated from host vesicular traffic. In this study, the origin of parasite cholesterol was investigated. T. gondii cannot synthesize sterols via the mevalonate pathway. Host cholesterol biosynthesis remains unchanged after infection and a blockade in host de ... More
Recycling of apoprotein E is associated with cholesterol efflux and high density lipoprotein internalization.
AuthorsHeeren J, Grewal T, Laatsch A, Rottke D, Rinninger F, Enrich C, Beisiegel U
JournalJ Biol Chem
PubMed ID12584196
After receptor-mediated endocytosis of triglyceride-rich lipoproteins (TRL) into the liver, TRL particles are immediately disintegrated in peripheral endosomal compartments. Whereas core lipids and apoprotein B are delivered for degradation into lysosomes, TRL-derived apoE is efficiently recycled back to the plasma membrane. This is followed by apoE re-secretion and association of ... More
Lateral diffusion in model membranes is independent of the size of the hydrophobic region of molecules.
AuthorsBalcom BJ, Petersen NO
JournalBiophys J
PubMed ID8218892
We have systematically investigated the probe size and shape dependence of lateral diffusion in model dimyristoyl phosphatidylcholine membranes. Linear hydrophobic polymers, which differ in length by an order of magnitude, were used to explore the effect on the lateral diffusion coefficient of hydrodynamic restrictions in the bilayer interior. The polymers ... More
Pro-sterol carrier protein-2: role of the N-terminal presequence in structure, function, and peroxisomal targeting.
AuthorsSchroeder F, Frolov A, Starodub O, Atshaves BB, Russell W, Petrescu A, Huang H, Gallegos AM, McIntosh A, Tahotna D, Russell DH, Billheimer JT, Baum CL, Kier AB
JournalJ Biol Chem
PubMed ID10833510
Although the 20-amino acid presequence present in 15-kDa pro-sterol carrier protein-2 (pro-SCP-2, the precursor of the mature 13-kDa SCP-2) alters the function of SCP-2 in lipid metabolism, the molecular basis for this effect is unresolved. The presequence dramatically altered SCP-2 structure as determined by circular dichroism, mass spectroscopy, and antibody ... More
Sterol carrier protein-2 alters high density lipoprotein-mediated cholesterol efflux.
AuthorsAtshaves BP, Starodub O, McIntosh A, Petrescu A, Roths JB, Kier AB, Schroeder F
JournalJ Biol Chem
PubMed ID10954705
Although sterol carrier protein-2 (SCP-2) participates in the uptake and intracellular trafficking of cholesterol, its effect on "reverse cholesterol transport" has not been explored. As shown herein, SCP-2 expression inhibited high density lipoprotein (HDL)-mediated efflux of [(3)H]cholesterol and fluorescent 22-(N-(7-nitrobenz-2-oxa-1, 3-diazol-4-yl)amino)-23,24-bisnor-5-cholen-3b-ol (NBD-cholesterol) up to 61 and 157%, respectively. Confocal microscopy ... More
Cholesterol distribution in living cells: fluorescence imaging using dehydroergosterol as a fluorescent cholesterol analog.
AuthorsMukherjee S, Zha X, Tabas I, Maxfield FR
JournalBiophys J
PubMed ID9746532
Cholesterol is an important constituent of most mammalian cell membranes and its concentration in various cellular membranes is tightly regulated. Although there is much information about cholesterol distribution and trafficking in cells, it is primarily derived from indirect measurements, and the results obtained using different approaches are often conflicting. A ... More
Cellular uptake and intracellular localization of benzo(a)pyrene by digital fluorescence imaging microscopy.
AuthorsPlant AL, Benson DM, Smith LC
JournalJ Cell Biol
PubMed ID3980583
Uptake of benzo(a)pyrene by living cultured cells has been visualized in real time using digital fluorescence-imaging microscopy. Benzo(a)pyrene was noncovalently associated with lipoproteins, as a physiologic mode of presentation of the carcinogen to cells. When incubated with either human fibroblasts or murine P388D1 macrophages, benzo(a)pyrene uptake occurred in the absence ... More
Digital imaging fluorescence microscopy: spatial heterogeneity of photobleaching rate constants in individual cells.
AuthorsBenson DM, Bryan J, Plant AL, Gotto AM, Smith LC
JournalJ Cell Biol
PubMed ID3920227
Photobleaching and related photochemical processes are recognized experimental barriers to quantification of fluorescence by microscopy. We have measured the kinetics of photobleaching of fluorophores in living and fixed cells and in microemulsions, and have demonstrated the spatial variability of these processes within individual cells. An inverted fluorescence microscope and a ... More
Visualization of lateral phases in cholesterol and phosphatidylcholine monolayers at the air/water interface--a comparative study with two different reporter molecules.
AuthorsSlotte JP, Mattjus P
JournalBiochim Biophys Acta
PubMed ID7811742
This study has compared two chemically distinct NBD-lipids with regard to their partitioning properties into lateral phases of pure and mixed cholesterol/phosphatidylcholine monolayers. Pure NBD-cholesterol (22-(N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino)-23,24-bisnor++ +-5-cholen-3-ol), which has the NBD-function in the sterol side chain (at carbon 22), gave a liquid-expanded force-area isotherm on water at 22 degrees C ... More
A fluorescent cholesterol analog traces cholesterol absorption in hamsters and is esterified in vivo and in vitro.
AuthorsSparrow CP, Patel S, Baffic J, Chao YS, Hernandez M, Lam MH, Montenegro J, Wright SD, Detmers PA
JournalJ Lipid Res
PubMed ID10508194
The fluorescent cholesterol analog 22-(N-(7-nitrobenz-2-oxa-1, 3-diazol-4-yl)amino)-23,24-bisnor-5-cholen-3beta-ol (fluoresterol) was characterized as a tool for exploring the biochemistry and cell biology of intestinal cholesterol absorption. Hamsters absorbed fluoresterol in a concentration- and time-dependent manner, with an efficiency of about 15-30% that of cholesterol. Fluoresterol absorption was blocked by compounds known to inhibit ... More
Cholesterol efflux to high-density lipoproteins and apolipoprotein A-I phosphatidylcholine complexes is inhibited by ethanol: role of apolipoprotein structure and cooperative interaction of phosphatidylcholine and cholesterol.
AuthorsAvdulov NA, Chochina SV, Igbavboa U, Wood WG
JournalBiochemistry
PubMed ID10956052
There is a substantial body of evidence showing that moderate alcohol consumption is associated with a reduced risk of cardiovascular morbidity and mortality. One of the factors thought to contribute to this reduction in risk is an increase in the level of high-density lipoproteins (HDL) correlated with alcohol consumption. However, ... More
Impaired platelet activation in familial high density lipoprotein deficiency (Tangier disease).
AuthorsNofer JR, Herminghaus G, Brodde M, Morgenstern E, Rust S, Engel T, Seedorf U, Assmann G, Bluethmann H, Kehrel BE
JournalJ Biol Chem
PubMed ID15163665
ATP binding cassette transporter A1 (ABCA1) is involved in regulation of intracellular lipid trafficking and export of cholesterol from cells to high density lipoproteins. ABCA1 defects cause Tangier disease, a disorder characterized by absence of high density lipoprotein and thrombocytopenia. In the present study we have demonstrated that ABCA1 is ... More
Fluorescence assay for phospholipid membrane asymmetry.
AuthorsMcIntyre JC, Sleight RG
JournalBiochemistry
PubMed ID1751498
Highly fluorescent 7-nitro-2,1,3-benzoxadiazol-4-yl-lipid (NBD-lipid) analogues are widely used to examine lipid transport and membrane structure. We have developed a method for chemically modifying NBD-labeled lipids in both artificial and biological membranes. This was achieved by treating fluorescently labeled membranes with dithionite (S2O4(-2)). When small unilamellar vesicles containing NBD-labeled phospholipids were ... More
Ehrlichia chaffeensis and Anaplasma phagocytophilum lack genes for lipid A biosynthesis and incorporate cholesterol for their survival.
AuthorsLin M, Rikihisa Y
JournalInfect Immun
PubMed ID12933880
Ehrlichia chaffeensis and Anaplasma phagocytophilum are agents of human monocytic and granulocytic ehrlichioses, respectively. They are extremely sensitive to mechanical stress and are pleomorphic gram-negative bacteria. Membrane incorporation of cholesterol from the eukaryotic host is known to be essential for other fragile and pleomorphic bacteria and mycoplasmas that lack a ... More
Holo-sterol carrier protein-2. (13)C NMR investigation of cholesterol and fatty acid binding sites.
AuthorsStolowich N, Frolov A, Petrescu AD, Scott AI, Billheimer JT, Schroeder F
JournalJ Biol Chem
PubMed ID10585412
Although sterol carrier protein-2 (SCP-2) stimulates sterol transfer in vitro, almost nothing is known regarding the identity of the putative cholesterol binding site. Furthermore, the interrelationship(s) between this SCP-2 ligand binding site and the recently reported SCP-2 long chain fatty acid (LCFA) and long chain fatty acyl-CoA (LCFA-CoA) binding site(s) ... More
Protein-disulfide isomerase is a component of an NBD-cholesterol monomerizing protein complex from hamster small intestine.
AuthorsCai TQ, Guo Q, Wong B, Milot D, Zhang L, Wright SD
JournalBiochim Biophys Acta
PubMed ID12020637
A rapid in vitro assay was developed for monitoring protein-mediated cholesterol monomerization from bile acid aggregates. This assay uses a fluorescent cholesterol analog, 22-(N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino)-23,24-bisnor-5-cholen-3 beta-ol (NBD-cholesterol), which was shown to be absorbed by hamster in a fashion similar to cholesterol. The fluorescence of aggregates of NBD-cholesterol was strongly quenched in ... More
Lipid diffusion in the plasma membrane of mouse spermatozoa: changes during epididymal maturation, effects of pH, osmotic pressure, and knockout of the c-ros gene.
AuthorsChristova Y, James PS, Cooper TG, Jones R
JournalJ Androl
PubMed ID12002440
It is well known that the plasma membranes of mammalian spermatozoa undergo extensive remodeling during maturation in the epididymal duct. In this investigation, we have used fluorescence recovery after photobleaching (FRAP) techniques to: 1) measure rates of lipid diffusion in the plasma membrane of mouse spermatozoa at different stages of ... More
Embryonic cholesterol esterification is regulated by a cyclic AMP-dependent pathway in yolk sac membrane-derived endodermal epithelial cells.
Authors
JournalPLoS One
PubMed ID29161294
TMEM41B is a host factor required for the replication of diverse coronaviruses including SARS-CoV-2.
Authors
JournalPLoS Pathog
PubMed ID34043740
The effects of cigarette smoking and smoking cessation on high-density lipoprotein functions: implications for coronary artery disease.
Authors
JournalAnn Clin Biochem
PubMed ID29961342
The Cholinergic Anti-Inflammatory Pathway Attenuates the Development of Atherosclerosis in Apoe-/- Mice through Modulating Macrophage Functions.
Authors
JournalBiomedicines
PubMed ID34572339
Synergistic inflammatory signaling by cGAS may be involved in the development of atherosclerosis.
Authors
JournalAging (Albany NY)
PubMed ID33589571
Phospholipid nanoparticles: Therapeutic potentials against atherosclerosis via reducing cholesterol crystals and inhibiting inflammation.
Authors
JournalEBioMedicine
PubMed ID34879325
Naoxintong Retards Atherosclerosis by Inhibiting Foam Cell Formation Through Activating Pparα Pathway.
Authors
JournalCurr Mol Med
PubMed ID30734676
Ketone Body 3-Hydroxybutyrate Ameliorates Atherosclerosis via Receptor Gpr109a-Mediated Calcium Influx.
Authors
JournalAdv Sci (Weinh)
PubMed ID33977048
Association Between ApoA-I (Apolipoprotein A-I) Immune Complexes and Adverse Cardiovascular Events-Brief Report.
Authors
JournalArterioscler Thromb Vasc Biol
PubMed ID31315438
The Alzheimer's disease-associated C99 fragment of APP regulates cellular cholesterol trafficking.