Analysis of P-glycoprotein-mediated membrane transport in human peripheral blood lymphocytes using the UIC2 shift assay.
AuthorsPark SW, Lomri N, Simeoni LA, Fruehauf JP, Mechetner E
JournalCytometry A
PubMed ID12766968
'BACKGROUND: During transport-associated adenosine triphosphate hydrolysis, P-glycoprotein (Pgp) undergoes conformation transitions detected by UIC2, a functional anti-Pgp monoclonal antibody. A newly developed UIC2 shift assay is based on increased UIC2 reactivity in the presence of Pgp substrates. All peripheral blood leukocytes express low Pgp levels. The existing antibody-based detection methods ... More
Fluorescent cationic probes of mitochondria. Metrics and mechanism of interaction.
AuthorsBunting JR, Phan TV, Kamali E, Dowben RM
JournalBiophys J
PubMed ID2605307
'Mitochondria strongly accumulate amphiphilic cations. We report here a study of the association of respiring rat liver mitochondria with several fluorescent cationic dyes from differing structural classes. Using gravimetric and fluorometric analysis of dye partition, we find that dyes and mitochondria interact in three ways: (a) uptake with fluorescence quenching, ... More
The repetitive calcium waves in the fertilized ascidian egg are initiated near the vegetal pole by a cortical pacemaker.
AuthorsSpeksnijder JE
JournalDev Biol
PubMed ID1397683
'Ascidian eggs respond to fertilization with a series of repetitive calcium waves that originate mostly from the vegetal/contraction pole region (J. E. Speksnijder, C. Sardet, and L. F. Jaffe, 1990, Dev. Biol. 142, 246-249), where the myoplasm is concentrated during the first phase of ooplasmic segregation. This suggests that the ... More
Transmembrane inhibitors of P-glycoprotein, an ABC transporter.
AuthorsTarasova NI, Seth R, Tarasov SG, Kosakowska-Cholody T, Hrycyna CA, Gottesman MM, Michejda CJ
JournalJ Med Chem
PubMed ID15916428
'Drug resistance mediated by ABC transporters such as P-glycoprotein (P-gp) continues to be a major impediment to effective cancer chemotherapy. We have developed a panel of highly specific peptide inhibitors of P-gp based on the structure of the transmembrane domains of the transporter. These peptides are thought to exert their ... More
DiOC2(3) is not a substrate for multidrug resistance protein (MRP)-mediated drug efflux.
AuthorsMinderman H, Vanhoefer U, Toth K, Yin MB, Minderman MD, Wrzosek C, Slovak ML, Rustum YM
JournalCytometry
PubMed ID8875050
'Multidrug resistance (MDR) is often related to expression of P-glycoprotein (Pgp) or Multidrug Resistance Protein (MRP). Pgp-mediated MDR can be evaluated by determining cellular retention of fluorescent substrates by flow cytometry. This study determined if agents used to evaluate Pgp function also can be used to evaluate MRP function. Cellular ... More
A test of the singlet oxygen mechanism of cationic dye photosensitization of mitochondrial damage.
AuthorsBunting JR
JournalPhotochem Photobiol
PubMed ID1603852
'Aromatic cationic dyes have a potential as photo-chemotherapeutic agents because they are selectively concentrated into the mitochondria of cancerous cells. The mechanism of cytophototoxicity has been proposed to be primarily due to dye sensitized photogeneration of highly toxic singlet oxygen (1O2) at the mitochondria. We tested this hypothesis by measuring ... More
Membrane potential modulates photocycling rates of bacterial rhodopsins.
AuthorsManor D, Hasselbacher CA, Spudich JL
JournalBiochemistry
PubMed ID3191096
'Effects of membrane potential on photochemical reactions of three retinal-containing chromoproteins in Halobacterium halobium, sensory rhodopsin I (sR-I), bacteriorhodopsin, and halorhodopsin, are described. Each of the three exhibits a decreased rate of thermal decay of its principal intermediate when photoactivated in an artificially energized compared to a deenergized membrane. The ... More
Selective staining by the fluorochrome, 5,5-diphenyl-9-ethyl-DiOC2(3). I. Physicochemical studies of dye-dye and dye-tissue interactions.
AuthorsHermel H, Schmahl W, Möhwald H
JournalBiotech Histochem
PubMed ID10711501
'The 5,5''-diphenyl-9-ethyl-oxacarbocyanine (5,5''-diphenyl-9-ethyl-DiOC2(3); CD) has properties suitable for histological investigations including the spectral range for absorption and fluorescence emission, the values of the corresponding molar coefficients and fluorescence quantum yield. Furthermore, CD remains relatively unchanged over the entire pH range and interacts with protein beta-sheets. The latter fact is detectable ... More
Dicarbocyanine fluorescent probes of membrane potential block lymphocyte capping, deplete cellular ATP and inhibit respiration of isolated mitochondria.
AuthorsMontecucco C, Pozzan T, Rink T
JournalBiochim Biophys Acta
PubMed ID87222
'3,3''-Dipropylthiodicarbocyanine iodide, a widely used fluorescent probe of membrane potential, was found to inhibit anti-Ig antibody, induced capping of mouse lymphocytes. The dye also lowered the cell ATP content. Experiments with isolated mitochondria revealed that the probe had a potent inhibitory action at site I of the respiratory chain. This ... More
Flow cytometric probes of early events in cell activation.
AuthorsShapiro HM
JournalCytometry
PubMed ID7023883
Role of actin in the responses of adrenal cells to ACTH and cyclic AMP: inhibition by DNase I.
AuthorsOsawa S, Betz G, Hall PF
JournalJ Cell Biol
PubMed ID6090470
'Erythrocyte ghosts were loaded with pancreatic DNase I and fused with Y-1 adrenal tumor cells to test the possibility that this enzyme might inhibit the steroidogenic responses of the cells to ACTH and cyclic AMP. Fusion of erythrocyte ghosts loaded with DNase I, but not those containing albumin, ovalbumin, boiled ... More
Accurate flow cytometric membrane potential measurement in bacteria using diethyloxacarbocyanine and a ratiometric technique.
AuthorsNovo D, Perlmutter NG, Hunt RH, Shapiro HM
JournalCytometry
PubMed ID10554181
'BACKGROUND: Membrane potential (MP) plays a critical role in bacterial physiology. Existing methods for MP estimation by flow cytometry are neither accurate nor precise, due in part to the heterogeneity of size of the particles analyzed. The ratio of a size- and MP-sensitive measurement, and an MP-independent, size-sensitive measurement, should ... More
The ability of membrane potential dyes and calcafluor white to distinguish between viable and non-viable bacteria.
AuthorsMason DJ, Lopéz-Amorós R, Allman R, Stark JM, Lloyd D
JournalJ Appl Bacteriol
PubMed ID7537262
'Various dyes were assessed for their ability to discriminate between viable and non-viable bacteria. Two methods of killing were employed: by heat treatment or by gramicidin treatment. Staining was carried out in two ways; by staining directly in the medium or by washing cells prior to staining in buffer. Carbocyanine ... More
Nondestructive detection of gangliosides with lipophilic fluorochromes and their employment for preparative high-performance thin-layer chromatography.
AuthorsMüthing J, Heitmann D
JournalAnal Biochem
PubMed ID8434781
'A simple and effective procedure for the isolation and purification of gangliosides by preparative thin-layer chromatography is described. The method is based on nondestructive visualization of gangliosides on silica gel-precoated thin-layer chromatography plates by staining with uncharged lipophilic fluorochromes. Fluorescent dyes were added in low concentrations into the mobile phase ... More
Studies on the mechanism by which cyanine dyes measure membrane potential in red blood cells and phosphatidylcholine vesicles.
AuthorsSims PJ, Waggoner AS, Wang CH, Hoffman JF
JournalBiochemistry
PubMed ID4842277
Carbocyanine dyes inhibit Ca-dependent K efflux from human red cell ghosts.
AuthorsSimons TJ
JournalNature
PubMed ID1004580
Lipid and salt effects on carbocyanine dye-induced photo-voltages in bilayer membranes.
Voltage transients induced by flash illumination of bilayer membranes with sorbed dye, 3,3' -dimethyl-2,2' -oxacarbocyanine chloride (diO-C1-3-CI), vary with membrane lipid composition and aqueous solution salt concentration. The voltage transients are probably induced by physical movements of sorbed dye molecules following photo-isomerization. Increased salt (NaCl and NaBr) concentrations in the ... More
Expression and activity of P-glycoprotein, a multidrug efflux pump, in human hematopoietic stem cells.
AuthorsChaudhary PM, Roninson IB
JournalCell
PubMed ID1712673
Hematopoietic stem cells show reduced staining with a mitochondrial fluorescent dye, rhodamine 123 (Rh-123), which was supposed to indicate decreased mitochondrial activity in these cells. Rh123 and several other fluorescent dyes are substrates for transport mediated by P-glycoprotein (P-gp), an efflux pump responsible for multidrug resistance in tumor cells. We ... More
Monitoring of relative mitochondrial membrane potential in living cells by fluorescence microscopy.
AuthorsJohnson LV, Walsh ML, Bockus BJ, Chen LB
JournalJ Cell Biol
PubMed ID6783667
Permeant cationic fluorescent probes are shown to be selectively accumulated by the mitochondria of living cells. Mitochondria-specific interaction of such molecules is apparently dependent on the high trans-membrane potential (inside negative) maintained by functional mitochondria. Dissipation of the mitochondrial trans-membrane and potential by ionophores or inhibitors of electron transport eliminates ... More
Microbial analysis at the single-cell level: tasks and techniques.
AuthorsShapiro HM
JournalJ Microbiol Methods
PubMed ID11000426
The heterogeneity of microorganisms themselves is orders of magnitude greater than the heterogeneity of perspectives from which they are contemplated by human observers. Even closely related species may exhibit marked differences in biochemistry and behavior, and, under many conditions, similar, striking heterogeneity may exist within a clonal population of organisms ... More
Influx and efflux kinetics of cationic dye binding to respiring mitochondria.
AuthorsBunting JR
JournalBiophys Chem
PubMed ID1567988
We have investigated the kinetics of interaction of cationic fluorescent lipophiles (dyes) rhodamine 123, rhodamine 6G, tetramethyl rhodamine ethyl ester, safranine O, 1,1'-diethyloxacarbocyanine, 1,1'-diethyloxadicarbocyanine, and 1,1'-diethylthiadicarbocyanine iodide with isolated respiring rat-liver mitochondria (RLM). Dye flux across the RLM inner membrane was measured by following the kinetics of fluorescence signal change ... More
Kinetics of transport of dialkyloxacarbocyanines in multidrug-resistant cell lines overexpressing P-glycoprotein: interrelationship of dye alkyl chain length, cellular flux, and drug resistance.
AuthorsWadkins RM, Houghton PJ
JournalBiochemistry
PubMed ID7893683
The membrane transport properties of a series of dialkyloxacarbocyanine [DiOCn(3)] dyes in multidrug-resistant KB cell lines were investigated to determine the influence of alkyl chain length on the ability of p-glycoprotein (i) to protect cells from the toxicity of the dyes and (ii) to affect the plasma membrane flux of ... More
Inhibition of mitochondrial and Paracoccus denitrificans NADH-ubiquinone reductase by oxacarbocyanine dyes. A structure-activity study.
AuthorsAnderson WM, Wood JM, Anderson AC
JournalBiochem Pharmacol
PubMed ID8512593
In this study, we determined that three structurally related oxacarbocyanine dyes, 3,3'-diethyloxacarbocyanine (DiOC2(3)), 3,3'-dipentyloxacarbocyanine (DiOC5(3)), and 3,3'-dihexyloxacarbocyanine (DiOC6(3)), and one oxadicarbocyanine, 3,3'-diethyloxadicarbocyanine (DiOC2(4)), inhibit bovine heart mitochondrial NADH oxidase activity and one of them, DiOC6(3), inhibits Paracoccus denitrificans NADH oxidase activity. The mitochondrial I50 values were 9 microM (DiOC2(3)), approximately ... More
Direct observation of sub-picosecond equilibration of excitation energy in the light-harvesting antenna of Rhodospirillum rubrum.
AuthorsVisser HM, Somsen OJ, van Mourik F, Lin S, van Stokkum IH, van Grondelle R
JournalBiophys J
PubMed ID8519962
Excitation energy transfer in the light-harvesting antenna of Rhodospirillum rubrum was studied at room temperature using sub-picosecond transient absorption measurements. Upon excitation of Rs. rubrum membranes with a 200 fs, 600 nm laser flash in the Qx transition of the bacteriochlorophyll-a (BChl-a) absorption, the induced transient absorption changes in the ... More
Highly sensitive and specific detection of P-glycoprotein function for haematological and solid tumour cells using a novel nucleic acid stain.
AuthorsBroxterman HJ, Schuurhuis GJ, Lankelma J, Oberink JW, Eekman CA, Claessen AM, Hoekman K, Poot M, Pinedo HM
JournalBr J Cancer
PubMed ID9376262
Progress in our understanding of the contribution of P-glycoprotein (P-gp)-mediated resistance to chemotherapy failure in haematological as well as solid tumours has been hampered by the lack of highly sensitive, reliable methods for the detection of P-gp function in fresh human tumour cells. The present study identifies the novel nucleic ... More
Cyanine dye structural and voltage-induced variations in photo-voltages of bilayer membranes.
AuthorsHuebner JS
JournalJ Membr Biol
PubMed ID641979
Flash illumination alters the voltage across bilayer lipid membranes in the presence of certain cyanine dyes. The waveforms of the photo-voltage vary systematically with dye structure and imposed transmembrane voltage. Experimental results are reported for 27 positively charged cyanine dyes, primarily oxazole derivatives, using lecithin/oxidized cholesterol bilayer membranes and 10-mM ... More
Membrane potential estimation by flow cytometry.
AuthorsShapiro HM
JournalMethods
PubMed ID10873481
Membrane potential (delta psi) is generated and maintained by concentration gradients of ions such as sodium, potassium, chloride, and hydrogen. Changes in cytoplasmic delta psi in the course of surface-receptor-mediated processes related to the development, function, and pathology of many cell types often play a role in transmembrane signaling. Cytoplasmic ... More
Evaluation of the clinical relevance of the expression and function of P-glycoprotein, multidrug resistance protein and lung resistance protein in patients with primary acute myelogenous leukemia.
AuthorsTsimberidou AM, Paterakis G, Androutsos G, Anagnostopoulos N, Galanopoulos A, Kalmantis T, Meletis J, Rombos Y, Sagriotis A, Symeonidis A, Tiniakou M, Zoumbos N, Yataganas X
JournalLeuk Res
PubMed ID11755464
The multidrug resistance (MDR) transporter-proteins P-glycoprotein (Pgp), multidrug resistance protein (MRP) and lung resistance protein (LRP) have been associated with treatment failure. The aim of this study was to investigate prospectively the clinical significance of expression and function of the MDR proteins, considering other prognostic factors, such as age, immunophenotype, ... More
Anti-apoptotic role of telomerase in pheochromocytoma cells.
AuthorsFu W, Begley JG, Killen MW, Mattson MP
JournalJ Biol Chem
PubMed ID10066788
Telomerase is a protein-RNA enzyme complex that adds a six-base DNA sequence (TTAGGG) to the ends of chromosomes and thereby prevents their shortening. Reduced telomerase activity is associated with cell differentiation and accelerated cellular senescence, whereas increased telomerase activity is associated with cell transformation and immortalization. Because many types of ... More
Dehydrothyrsiferol does not modulate multidrug resistance-associated protein 1 resistance: a functional screening system for MRP1 substrates.
AuthorsPec MK, Aguirre A, Fernández JJ, Souto ML, Dorta JF, Villar J
JournalInt J Mol Med
PubMed ID12373300
We had shown previously that the novel, marine, anticancer compound dehydrothyrsiferol (DHT) does not modulate P-glycoprotein (P-gp) dependent drug efflux. Many chemotherapeutics with clinical impact are substrates for the structurally distant related membrane transport protein MRP1 (multidrug resistance-associated protein 1). Thus, we were interested in analysing the behaviour of DHT ... More
Multiparameter flow cytometric analysis of antibiotic effects on membrane potential, membrane permeability, and bacterial counts of Staphylococcus aureus and Micrococcus luteus.
Although flow cytometry has been used to study antibiotic effects on bacterial membrane potential (MP) and membrane permeability, flow cytometric results are not always well correlated to changes in bacterial counts. Using new, precise techniques, we simultaneously measured MP, membrane permeability, and particle counts of antibiotic-treated and untreated Staphylococcus aureus ... More
Actions of a carbocyanine dye on calcium-dependent potassium transport in human red cell ghosts.
AuthorsSimons TJ
JournalJ Physiol
PubMed ID469731
1. 3,3'-Diethylthiadicarbocyanine iodide (diS-C2-(5)), a fluorescent dye widely used to estimate membrane potentials, inhibits the Ca-dependent K transport system of human red cells and ghosts. It does not affect non-specific cation leaks, net chloride movements or the Ca-activated ATPase. 2. The nature of the inhibitory effect depends upon the conditions ... More
Membrane activity profiling of small molecule B. subtilis growth inhibitors utilizing novel duel-dye fluorescence assay.