High-speed photodamage cell selection using bromodeoxyuridine/Hoechst 33342 photosensitized cell killing.
AuthorsHerweijer H, Stokdijk W, Visser JW
JournalCytometry
PubMed ID2452055
One of the major drawbacks of droplet sorting in a flow cytometer is the relatively low sorting speed. Thus, we have developed an alternative, faster sorting technique: photodamage cell sorting. In a photodamage cell sorter all unwanted cells, as detected with the first, measuring laser, are killed with the second, ... More
Mechanism and kinetics of merocyanine 540 binding to phospholipid membranes.
AuthorsVerkman AS
JournalBiochemistry
PubMed ID3651436
The physicochemical mechanism for merocyanine 540 (M540) binding to unilamellar phosphatidylcholine (PC) vesicles was examined by steady-state and dynamic fluorescence and fluorescence stopped-flow methods. At 530-nm excitation, aqueous M540 has an emission peak at 565 nm, which red shifts to 580 nm with formation of membrane-bound monomers (M); bound dimers ... More
Photodynamic action of merocyanine 540 on leukemia cells: iron-stimulated lipid peroxidation and cell killing.
AuthorsLin F, Girotti AW
JournalArch Biochem Biophys
PubMed ID8434951
'Merocyanine 540 (MC540) is a lipophilic photosensitizing dye of biomedical interest in connection with its ability to preferentially inactivate leukemia cells in bone marrow grafts and enveloped viruses in blood products. Evidence that iron plays a role in dye-mediated photokilling is presented in this report. When sensitized with MC540 and ... More
Temperature-jump studies of merocyanine 540 relaxation kinetics in lipid bilayer membranes.
AuthorsVerkman AS, Frosch MP
JournalBiochemistry
PubMed ID4084566
'The temperature-jump technique was used to study the rapid kinetics of merocyanine 540 (M-540) interactions with single-walled phosphatidylcholine (PC) vesicles. The absorption spectrum of M-540 in PC vesicles has an isosbestic point at 560 nm at low [PC]/[M-540], where solution M-540 and membrane-bound M-540 dimers are present, and an isosbestic ... More
Herpes virus infection and repair in cells pretreated with gilvocarcin V or merocyanine 540 and radiation.
AuthorsLytle CD, Routson LB, Prodouz KN
JournalJ Photochem Photobiol B
PubMed ID8021752
'Pretreatment of mammalian cells with certain genotoxic agents decreases the ability of the cell monolayers to support virus plaque formation but enhances repair of UV-irradiated virus. This study was made to determine whether these phenomena extend to pretreatments with light and photosensitizers, including one dye that primarily affects cell membranes. ... More
The components of merocyanine-540 absorption spectra in aqueous, micellar and bilayer environments.
AuthorsKaschny P, Goñi FM
JournalEur J Biochem
PubMed ID1379915
'Spectral-data-processing and curve-fitting techniques have been applied to the decomposition of merocyanine-540 absorption spectra in aqueous, micellar and bilayer environments. The various resolved component bands have been assigned to dye monomers, dimers, or larger aggregates, either in polar or non-polar environments. The analysis of spectral parameters (lambda max and integrated ... More
Heat-induced alterations in monkey erythrocyte membrane phospholipid organization and skeletal protein structure and interactions.
AuthorsKumar A, Gudi SR, Gokhale SM, Bhakuni V, Gupta CM
JournalBiochim Biophys Acta
PubMed ID2261489
'Rhesus monkey erythrocytes were subjected to heating at 50 degrees C for 5-15 min, and the heat-induced effects on the membrane structure were ascertained by analysing the membrane phospholipid organization and membrane skeleton dynamics and interactions in the heated cells. Membrane skeleton dynamics and interactions were determined by measuring the ... More
Fc receptor off-signal in the B cell involves apoptosis.
AuthorsAshman RF, Peckham D, Stunz LL
JournalJ Immunol
PubMed ID8683155
'By linking surface Ig to the FcR Fc gamma RII on the mouse B lymphocyte surface, whole anti-Ig has been shown to block cell cycle entry and subsequent Ab production, a phenomenon called the "Fc receptor off-signal." IL-4 or blocking Ab to Fc gamma RII, present with whole anti-Ig, restores ... More
Ionizing radiation down-regulates p53 protein in primary Egr-1-/- mouse embryonic fibroblast cells causing enhanced resistance to apoptosis.
AuthorsDas A, Chendil D, Dey S, Mohiuddin M, Mohiuddin M, Milbrandt J, Rangnekar VM, Ahmed MM
JournalJ Biol Chem
PubMed ID11035041
'In this study, we sought to investigate the mechanism of the proapoptotic function of Egr-1 in relation to p53 status in normal isogenic cell backgrounds by using primary MEF cells established from homozygous (Egr-1(-/-)) and heterozygous (Egr-1(+/-)) Egr-1 knock-out mice. Ionizing radiation caused significantly enhanced apoptosis in Egr-1(+/-) cells (22.8%; ... More
CpG oligodeoxyribonucleotides rescue mature spleen B cells from spontaneous apoptosis and promote cell cycle entry.
AuthorsYi AK, Chang M, Peckham DW, Krieg AM, Ashman RF
JournalJ Immunol
PubMed ID9637502
'Isolated murine splenic B cells undergo spontaneous apoptosis. Motifs containing unmethylated CpG dinucleotides in bacterial DNA or in synthetic oligodeoxynucleotides (ODN) are known to activate murine B cells. Now we show that ODN that induce spleen B cell cycle entry also inhibit spontaneous apoptosis in a sequence-specific fashion. Reversal of ... More
Direct observation of singlet oxygen production by merocyanine 540 associated with phosphatidylcholine liposomes.
AuthorsFeix JB, Kalyanaraman B, Chignell CF, Hall RD
JournalJ Biol Chem
PubMed ID3182846
'The production of singlet molecular oxygen (1O2) by the photosensitizing dye merocyanine 540 (MC540) bound to phosphatidylcholine liposomes has been demonstrated by direct detection of 1O2 luminescence at 1268 nm. 1O2 phosphorescence emission was enhanced in deuterated buffer and upon saturation of the sample with oxygen and could be quenched ... More
Interaction of merocyanine 540 with nicotinic acetylcholine receptor membranes from Discopyge tschudii electric organ.
'Interactions between merocyanine 540 (MC540) and nicotinic acetylcholine receptor (AChR) have been studied by visible absorption spectroscopy using native receptor-rich membranes from Discopyge tschudii electric tissue and liposomes obtained by aqueous dispersion of endogenous lipids extracted from the same tissue. The fact that merocyanine partitions into the membrane when this ... More
Nucleic acid dyes for detection of apoptosis in live cells.
AuthorsFrey T
JournalCytometry
PubMed ID8582249
'Apoptotic thymocytes were found to be much dimmer than normal thymocytes when stained with several nucleic acid dyes. These dyes provide a quick and simple assay for apoptosis which works for live cells and does not require a UV laser. The collection of dyes giving this staining pattern includes reagents ... More
Relation between the organization of spectrin and of membrane lipids in lymphocytes.
AuthorsDel Buono BJ, Williamson PL, Schlegel RA
JournalJ Cell Biol
PubMed ID3279051
'In lymphocytes, the cytoskeletal protein spectrin exhibits two organizational states. Because the plasma membrane lipids of lymphocytes also display two organizational states, it was asked whether there is a relation between the organization of spectrin and of membrane lipids. When mouse thymocytes were stained with merocyanine 540 (MC540), a fluorescent ... More
Echinocytosis and microvesiculation of human erythrocytes induced by insertion of merocyanine 540 into the outer membrane leaflet.
AuthorsAllan D, Hagelberg C, Kallen KJ, Haest CW
JournalBiochim Biophys Acta
PubMed ID2819089
'Echinocytosis and release of microvesicles from human erythrocytes treated with the impermeant fluorescent dye merocyanine 540 (MC540) has been correlated with the extent of dye binding to intact cells and ghosts. At 20 degrees C binding appeared to saturate at about 9.3.10(6) molecules per cell (3.6 mol/100 mol phospholipid), equivalent ... More
Merocyanine 540 recognizes membrane abnormalities of erythrocytes in chronic myelogenous leukemia.
AuthorsReed JA, Kough RH, Williamson PL, Schlegel RA
JournalCell Biol Int Rep
PubMed ID3856489
'Merocyanine 540 is a fluorescent dye which stains erythrocytes that have lost their normal membrane phospholipid asymmetry. Because erythrocytes from patients with chronic myelogenous leukemia have been reported to display this abnormal phenotype, peripheral blood erythrocytes from such patients were examined for their ability to stain with the dye. Erythrocytes ... More
Fluid flow increases membrane permeability to merocyanine 540 in human endothelial cells.
AuthorsBerthiaume F, Frangos JA
JournalBiochim Biophys Acta
PubMed ID8155677
'Fluid shear stress is a ubiquitous stimulus of mammalian cell metabolism; however, its signal transduction pathway is unknown. We hypothesized that shear stress may alter some physical properties of the cell membrane. Using primary human umbilical vein endothelial cells (HUVECs), we investigated the effects of shear on the cell membrane ... More
Cellular membrane composition defines A beta-lipid interactions.
AuthorsWaschuk SA, Elton EA, Darabie AA, Fraser PE, McLaurin JA
JournalJ Biol Chem
PubMed ID11438533
'Alzheimer''s disease pathology has demonstrated amyloid plaque formation associated with plasma membranes and the presence of intracellular amyloid-beta (A beta) accumulation in specific vesicular compartments. This suggests that lipid composition in different compartments may play a role in A beta aggregation. To test this hypothesis, we have isolated cellular membranes ... More
Light-induced permeabilization and merocyanine 540 staining of mouse spleen cells.
AuthorsSzabo G, Rédai I, Bacso Z, Hevessy J, Damjanovich S
JournalBiochim Biophys Acta
PubMed ID2466486
'Merocyanine 540 (M540) is a potential-sensitive, hydrophobic dye that preferentially incorporates into the ''fluid'' domains of cellular membranes, distinguishing between hemopoietic cells according to their differentiation state. A bright staining with M540 is usually achieved by UV illumination of the cells during staining. We show by flow cytometric analysis that: ... More
Lipid composition determines the effects of arbutin on the stability of membranes.
AuthorsHincha DK, Oliver AE, Crowe JH
JournalBiophys J
PubMed ID10512822
'Arbutin (hydroquinone-beta-D-glucopyranoside) is an abundant solute in the leaves of many freezing- or desiccation-tolerant plants. Its physiological role in plants, however, is not known. Here we show that arbutin protects isolated spinach (Spinacia oleracea L.) thylakoid membranes from freeze-thaw damage. During freezing of liposomes, the presence of only 20 mM ... More
Studies of light emission, absorption and energy transfer in nerve membranes labelled with fluorescent probes.
AuthorsTasaki I, Warashina A, Pant H
JournalBiophys Chem
PubMed ID1247647
'Physicochemical properties of fluorescent membrane probes, 2-p-Cl-anilinonaphthalene-6-sulfonate (p-Cl-ANS), 2-p-Br-anilinonaphthalene-6-sulfonate (p-Br-ANS), merocyanine-540, methyl violet, etc., were examined because of the possibility of demonstrating resonance energy-transfer between probes. The emission psectra of p-Cl-ANS and p-Br-ANS and the absorption (or fluorescence excitation) spectra of Eastman Kodak merocyanine-540 (M-540) and other probes were found ... More
Alterations in plasma membrane lipid organization during lymphocyte differentiation.
AuthorsDel Buono BJ, Williamson PL, Schlegel RA
JournalJ Cell Physiol
PubMed ID2419347
'The fluorescent probe merocyanine 540, which binds preferentially to bilayers in which the lipids are loosely packed, was used to investigate changes in the organization of the lipids of the lymphocyte plasma membrane during primary and secondary lymphopoiesis. When mouse thymocytes were incubated with the dye, most immature cells stained, ... More
Merocyanine 540 as a probe to monitor the molecular packing of phosphatidylcholine: a monolayer epifluorescence microscopy and spectroscopy study.
AuthorsYu H, Hui SW
JournalBiochim Biophys Acta
PubMed ID1504069
'The characteristics of the fluorescent dye, merocyanine 540 (MC-540), incorporated in monolayers of 1,2-dipalmitoyl-phosphatidylcholine (DPPC), and 1-palmitoyl-2-oleoylphosphatidylcholine (POPC) were studied in different states of molecular packing. Conditions for phase separation in these monolayers were defined by their pressure/area (pi-A) isotherms. Within the liquid expanded (LE) and the liquid condensed (LC) ... More
Effect of glycerol on the interfacial properties of dipalmitoylphosphatidylcholine liposomes as measured with merocyanine 540.
AuthorsBiondi AC, Disalvo EA
JournalBiochim Biophys Acta
PubMed ID1698456
'Liposomes of dipalmitoylphosphatidylcholine (DPPC) prepared in increasing glycerol/glucose ratios show an increase in the absorbance at 570 nm of merocyanine spectra at temperatures below the phase transition. Since this effect is not observed when liposomes are prepared in solutions containing solely glucose, it is attributed to specific interactions of glycerol ... More
Merocyanine 540-sensitized photoinactivation of high-grade non-Hodgkin's lymphoma cells: potential application in autologous BMT.
AuthorsItoh T, Messner HA, Jamal N, Tweeddale M, Sieber F
JournalBone Marrow Transplant
PubMed ID8241975
'This paper reports on the preclinical evaluation of merocyanine 540 (MC540) as an agent for the inactivation of tumour cells in BM grafts from non-Hodgkin''s lymphoma (NHL) patients. The three cell lines used for this study, OCI-LY13.1, OCI-LY13.2 and OCI-LY9, originate from two patients with high-grade NHL. The OCI-LY13.1 and ... More
Plasma membrane lipid order of leukemic and normal immature avian erythroid cells.
AuthorsCofer GP, Williamson P, Schlegel RA
JournalExp Cell Res
PubMed ID6376154
'Mammalian erythroblasts and their leukemic counterparts contain characteristic disordered regions of plasma membrane identified as putative membrane protein collection sites. In order to determine whether erythroid cells which do not enucleate contain homologous membrane domains, immature avian erythroid precursor cells and avian erythroleukemic cells were examined using merocyanine 540 (MC540), ... More
Apoptotic events induced by the phosphatase inhibitor okadaic acid in normal human lung fibroblasts.
AuthorsLeira F, Vieites JM, Vieytes MR, Botana LM
JournalToxicol In Vitro
PubMed ID11377092
'We have studied different biochemical indicators of apoptosis in okadaic acid-treated normal human lung fibroblasts (NHLF). Apoptosis was identified by fluorimetric microplate measurements of DNA content, caspase-3 activation and changes in mitochondrial and plasma membrane after 1-48-h treatments with 1-1000 nM okadaic acid. Cells exposed to okadaic acid showed activation ... More
Abnormal membrane protein methylation and merocyanine 540 fluorescence in sickle erythrocyte membranes.
AuthorsManna C, Hermanowicz N, Ro JY, Neilan B, Glushko V, Kim S
JournalBiochem Med
PubMed ID6477541
'Sickle cell erythrocytes exhibit reduced carboxyl methylation of membrane proteins compared to normal erythrocytes. This altered methylation in sickle membrane proteins is also observable when extracted membranes, both intact and alkali treated, were used as substrates for the homologous protein methylase II (S-adenosylmethionine:protein-carboxyl O-methyltransferase, EC. 2.1.1.24). However, when glycophorin A, ... More
Phototherapeutic potential of alternative photosensitizers to porphyrins.
AuthorsDiwu Z, Lown JW
JournalPharmacol Ther
PubMed ID7972342
'Because of promising clinical results obtained with photodynamic therapy, more and more photosensitizers continue to be isolated (from natural sources), synthesized and evaluated, the development of which is considered to be a key factor for the successful clinical application of photodynamic therapy. Porphyrins and their analogs (as classical types of ... More
Cholesterol content but not plasma membrane fluidity influences the susceptibility of L1210 leukemia cells to merocyanine 540-sensitized irradiation.
AuthorsGaffney DK, Feix JB, Schwarz HP, Struve MF, Sieber F
JournalPhotochem Photobiol
PubMed ID1798749
'This paper examines the relationship between lipid composition, plasma membrane fluidity, expression of dye binding sites, and susceptibility to merocyanine 540 (MC540)-sensitized irradiation in L1210 leukemia cells. Reducing the cells'' cholesterol content by exchange diffusion with phosphatidylcholine liposomes or by inhibiting its biosynthesis with 25-hydroxycholesterol enhanced plasma membrane fluidity, the ... More
Mechanisms governing the level of susceptibility of erythrocyte membranes to secretory phospholipase A2.
AuthorsJensen LB, Burgess NK, Gonda DD, Spencer E, Wilson-Ashworth HA, Driscoll E, Vu MP, Fairbourn JL, Judd AM, Bell JD
JournalBiophys J
PubMed ID15681653
'Although cell membranes normally resist the hydrolytic action of secretory phospholipase A(2) (sPLA(2)), they become susceptible during apoptosis or after cellular trauma. Experimentally, susceptibility to the enzyme can be induced by loading cells with calcium. In human erythrocytes, the ability of the calcium ionophore to cause susceptibility depends on temperature, ... More
Versatility of merocyanine 540 for the flow cytometric detection of apoptosis in human and murine cells.
AuthorsLaakko T, King L, Fraker P
JournalJ Immunol Methods
PubMed ID11861071
'Since apoptosis plays many roles in development, immune function, and disease, there is an ongoing need to identify inexpensive and reliable fluorochromes for the quantitation of apoptosis. Merocyanine 540 (MC540) binds to the outer membrane of cells and readily fluoresces in the highly disordered membranes of apoptotic cells making them ... More
Gel state surface properties of phosphatidylcholine liposomes as measured with merocyanine 540.
AuthorsBernik DL, Disalvo EA
JournalBiochim Biophys Acta
PubMed ID7680899
'The surface properties of liposomes composed by saturated phosphatidylcholines and their mixtures with cholesterol in the gel state have been studied using merocyanine 540 as a fluorescent and optical probe. A new absorption peak at 450 nm and a new fluorescent band at 630 nm were observed when the dye ... More
Plasma membrane lipid organization and the adherence of differentiating lymphocytes to macrophages.
AuthorsDel Buono BJ, White SM, Williamson PL, Schlegel RA
JournalJ Cell Physiol
PubMed ID2910888
'Changes in the packing of phospholipids in the plasma membrane of lymphocytes occur during differentiation within primary and secondary lymphoid organs. As they differentiate, lymphocytes interact with a variety of reticuloendothelial cells, including macrophages. To investigate a possible relation between these two phenomena, the strength of the interactions between lymphocytes ... More
Cathepsin D and H2O2 stimulate degradation of thioredoxin-1: implication for endothelial cell apoptosis.
'Cathepsin D (CatD) is a lysosomal aspartic proteinase and plays an important role in the degradation of proteins and in apoptotic processes induced by oxidative stress, cytokines, and aging. All of these stimuli are potent inducers of endothelial cell apoptosis. Therefore, we investigated the role of CatD in endothelial cell ... More
Photobleaching of merocyanine 540: involvement of singlet molecular oxygen.
AuthorsSingh RJ, Feix JB, Kalyanaraman B
JournalPhotochem Photobiol
PubMed ID1620725
'The purpose of this study was to assess the mechanism of merocyanine 540 (MC540) photobleaching in a liposomal system. Broad based visible irradiation of MC540 in unilamellar dilauroylphosphatidylcholine (DLPC) vesicles resulted in dye bleaching that was strictly O2 dependent. The rate of self-sensitized photobleaching was enhanced in D2O and inhibited ... More
A model for the extracellular release of PAF: the influence of plasma membrane phospholipid asymmetry.
AuthorsBratton DL, Kailey JM, Clay KL, Henson PM
JournalBiochim Biophys Acta
PubMed ID1705442
'Recent studies suggesting that cellular activation leads to enhanced transbilayer movement of phospholipids and loss of plasma membrane phospholipid asymmetry lead us to hypothesize that such events may govern the release of PAF, a potent, but variably release, lipid mediator synthesized by numerous inflammatory cells. To model these membrane events, ... More
Plasma membrane vesicles from BHK and HL60 cells treated with merocyanine 540 and iodoacetamide.
AuthorsWhatmore J, Quinn P, Allan D
JournalBiochim Biophys Acta
PubMed ID8218330
'Treatment of BHK or HL60 cell lines with merocyanine 540 in the presence of the sulphydryl blocker iodoacetamide caused budding of the cell surface to release vesicles about 50-100 nm in diameter which accounted for up to 25% of the total surface membrane lipid. Smaller amounts of vesicular material were ... More
Identification of normal and leukemic granulocytic cells with merocyanine 540.
AuthorsKass L
JournalStain Technol
PubMed ID2420042
'After fixation in a modified Bouin''s solution, the acid dye merocyanine 540 stained granules in granulocytic cells intensely. In immature granulocytes, such as promyelocytes and myelocytes, granules stained pink to violet. In some leukemic myeloblasts, promyelocytes and monocytes, granules also stained deep pink to violet. In more mature granulocytes, such ... More
A fluorescent dye which recognizes mature peripheral erythrocytes of myeloproliferative disorders.
AuthorsReed JA, Green R, Yamada Y, Kough RH, Williamson P, Schlegel RA
JournalCell Biol Int Rep
PubMed ID3829130
'Based on the previous finding that erythrocytes from patients with chronic myelogenous leukemia stain with the fluorescent dye merocyanine 540, erythrocytes from patients with other myeloproliferative disorders were examined for their ability to bind the membrane probe. As assessed by both fluorescence staining and a quantitative dye removal assay, all ... More
Cytoprotection against merocyanine 540-sensitized photoinactivation of the Na+,K(+)-adenosine triphosphatase in leukemia cells: glutathione and selenoperoxidase involvement.
AuthorsLin F, Girotti AW
JournalPhotochem Photobiol
PubMed ID8016211
'When irradiated with broad-band visible light in the presence of merocyanine 540 (MC540), murine leukemia L1210 cells grown under selenium-deficient conditions (Se(-) cells) accumulated lipid hydroperoxides and lost viability more rapidly than selenium-satisfied (Se(+) cells). These findings suggest that cytoprotection against photoperoxidation and photokilling is mediated at least in part ... More
Production of singlet oxygen-derived hydroxyl radical adducts during merocyanine-540-mediated photosensitization: analysis by ESR-spin trapping and HPLC with electrochemical detection.
AuthorsFeix JB, Kalyanaraman B
JournalArch Biochem Biophys
PubMed ID1656888
'Activated oxygen species produced during merocyanine 540 (MC540)-mediated photosensitization have been examined by electron spin resonance (ESR) spin trapping and by trapping reactive intermediates with salicylic acid using HPLC with electrochemical detection (HPLC-EC) for product analysis. Visible light irradiation of MC540 associated with dilauroylphosphatidylcholine liposomes in the presence of the ... More
Increased saturated triacylglycerol levels in plasma membranes of human neutrophils stimulated by lipopolysaccharide.
'Neutrophils isolated from patients with bacterial infections or stimulated in vitro with lipopolysaccharide (LPS) produce a high resolution, lipid-dominated spectrum on 1H-NMR spectroscopy (May et al, 1993. J. Infect. Dis. 168: 386-392). We have investigated the origin of this lipid signal using NMR and chemical analyses of both whole neutrophils ... More
Spectroscopic evidence for interactions of merocyanine 540 with valinomycin in the presence of potassium.
AuthorsLavie E, Sonenberg M
JournalFEBS Lett
PubMed ID7358170
Merocyanine 540-mediated photosensitization of leukemia and solid tumor cells.
AuthorsSieber F
JournalProg Clin Biol Res
PubMed ID3887425
Flow cytometric probes of early events in cell activation.
AuthorsShapiro HM
JournalCytometry
PubMed ID7023883
Inactivation of photosensitizing merocyanine dyes by plasma, serum and serum components.
AuthorsAnderson GS, Günther WH, Searle R, Bilitz JM, Krieg M, Sieber F
JournalPhotochem Photobiol
PubMed ID8863474
'Merocyanine dyes with an oxygen in the electron donor heterocycle were rapidly degraded by plasma, serum and serum components. Replacement of the oxygen by a sulfur or selenium atom rendered the dyes refractory to degradation. The degradation of labile merocyanine dyes was temperature dependent and oxygen independent. The plasma component ... More
Differential sensitivity of mouse hematopoietic stem cells to merocyanine 540.
AuthorsSieber F, Meagher RC, Spivak JL
JournalDifferentiation
PubMed ID7327314
'In vivo and in vitro clonal assays of immature mouse blood cells showed that different populations of hematopoietic progenitor cells differ considerably with respect to their sensitivity to photodynamic damages caused by the fluorescent dye Merocyanine 540. Late erythroid progenitors were the most sensitive cells followed in order of decreasing ... More
Perturbations of membrane structure by optical probes: I. Location and structural sensitivity of merocyanine 540 bound to phospholipid membranes.
AuthorsLelkes PI, Miller IR
JournalJ Membr Biol
PubMed ID6892646
Merocyanine 540 alters the self-renewal capacity of murine pluripotent hemopoietic stem cells.
AuthorsKerk DK, Myers CP, Hays EF
JournalExp Hematol
PubMed ID6641826
'Merocyanine 540 (MC 540), an impermeant photoreactive dye with a high affinity for the plasma membrane of hemopoietic precursors, was examined for effects on the self-replicative capacity (SR) of CFUS from normal mouse marrow, and on various CFUS subpopulations fractionated by velocity sedimentation. Brief exposure (30 s) of whole marrow ... More
Cytoskeletal influence on merocyanine 540 receptors in the plasma membrane of erythroleukemic cells.
AuthorsHunt RC, Hood JA
JournalBiochim Biophys Acta
PubMed ID6949612
'When human erythroleukemic cells are induced to differentiate in vitro, the lipids in the plasma membrane that bind the fluorescent dye merocyanine 540 are redistributed into a cap at one pole of the cell. This capping phenomenon can also be observed in uninduced cells that have been incubated with cytochalasin ... More
Dynamics of merocyanine 540 in model biomembranes: photoisomerization studies in small unilamellar vesicles.
AuthorsOnganer Y, Quitevis EL
JournalBiochim Biophys Acta
PubMed ID8204647
'The fluorescence lifetime, tau f, of merocyanine 540 (MC540) in small unilamellar vesicles was measured as a function of temperature and cholesterol content by using phase modulation fluorometry. These vesicles were formed by probe sonication of aqueous suspensions of egg phosphatidylcholine (PC) and cholesterol. The fluorescence lifetime of MC540 in ... More
Destruction of stearic acid nitroxyl radicals mediated by photoexcited merocyanine 540 in liposomal and micellar systems.
AuthorsHoebeke M, Seret A, Piette J, Van de Vorst A
JournalBiochemistry
PubMed ID8383524
'Fatty acid spin labels have been included into liposomes and micelles, in order to study the photochemical behavior of merocyanine 540 toward nitroxyl radicals situated at various depths in the bilayer or the surfactant layer. Visible illumination of the dye, either free in ethanol or bound to liposomes or micelles, ... More
Comparison of the cytotoxic effects of merocyanine-540 on leukemic cells and normal human bone marrow.
AuthorsAtzpodien J, Gulati SC, Clarkson BD
JournalCancer Res
PubMed ID3756850
'Various chemical compounds have been described to induce photosensitization of tumor cells resulting in cell death. We studied the effect of merocyanine-540 (MC-540) on both leukemic and normal bone marrow (BM) cells. Acute promyelocytic leukemia (HL-60) and common acute lymphoblastic leukemia antigen-positive non-T, non-B acute lymphoblastic leukemia (Reh) cell lines ... More
Transport of the cationic fluorochrome rhodamine 123 in an insect's Malpighian tubule: indications of a reabsorptive function of the secondary cell type.
AuthorsMeulemans W, De Loof A
JournalJ Cell Sci
PubMed ID1629249
'The pathway of rhodamine 123 was examined after injection into Sarcophaga flies and after in vitro labeling of the Malpighian tubules. After in vitro labeling the primary cells only retained this potential-sensitive dye for a short period while all secondary cells accumulated the dye from the tubule lumen. In vivo ... More
Enhancement of merocyanine 540-mediated phototherapy by salicylate.
AuthorsAnderson MS, Kalyanaraman B, Feix JB
JournalCancer Res
PubMed ID8381329
'Merocyanine 540 (MC540) is a photosensitizing dye of potential use in the purging of cancer cells from autologous bone marrow explants. Treatment of marrow with MC540, followed by illumination with visible light, selectively kills neoplastic cells while sparing a sufficient number of stem cells to allow marrow engraftment. The photodynamic ... More
Mechanism of the membrane potential sensitivity of the fluorescent membrane probe merocyanine 540.
AuthorsDragsten PR, Webb WW
JournalBiochemistry
PubMed ID728397
'The fluorescence and optical absorption of the membrane-staining dye merocyanine 540 (M-540) have been widely used to measure cellular transmembrane potentials. We have studied the molecular mechanisms of these optical changes by measuring the fluorescence polarization of M-540 and its response to membrane potential changes in hemispherical lipid bilayer membranes. ... More
Photosensitized lipid peroxidation and enzyme inactivation by membrane-bound merocyanine 540: reaction mechanisms in the absence and presence of ascorbate.
AuthorsBachowski GJ, Pintar TJ, Girotti AW
JournalPhotochem Photobiol
PubMed ID1857743
'The lipophilic photosensitizing dye merocyanine 540 (MC540) is being studied intensively as an antitumor and antiviral agent. Since plasma membranes are believed to be the principal cellular targets of MC540-mediated photodamage, we have studied membrane damage in a well characterized test system, the human erythrocyte ghost. When irradiated with white ... More
Dye-mediated photosensitization of murine neuroblastoma cells.
AuthorsSieber F, Sieber-Blum M
JournalCancer Res
PubMed ID3512078
'The purpose of this study was to determine if photosensitization mediated by the fluorescent dye, merocyanine 540, could be used to preferentially kill murine neuroblastoma cells in simulated autologous remission marrow grafts. Simultaneous exposure of Neuro 2a or NB41A3 neuroblastoma cells to merocyanine 540 and white light reduced the concentration ... More
Photochemical purging of autologous bone marrow grafts: assessment of damage to stem cells and the microenvironment in long-term marrow cultures.
AuthorsKubo Y, Sieber F
JournalBone Marrow Transplant
PubMed ID9232252
'Toxicity of merocyanine 540 (MC540) was assessed in long-term (Dexter-type) bone marrow cultures and in a short-term in vitro clonal assay of fibroblast colony-forming cells (CFU-F). Exposure of freshly explanted mouse bone marrow cells to MC540 (15 micrograms/ml) and white light (fluence: 126 kJ/m2) reduced CFU-F by approximately 2 logs ... More
Fluorescent properties of merocyanine 540 in solutions of sialogangliosides.
AuthorsGuarcello V, Stern A, Rizza V
JournalBiochim Biophys Acta
PubMed ID3801506
'The spectral modifications in the absorption and emission properties of merocyanine 540 have been evaluated in solvents of varying dielectric constants. The fluorescence behavior of dye in solutions of low dielectric constant has offered a possibility for monitoring the micropolarity of sialoganglioside micelles in aqueous solutions. Our results demonstrate that ... More
Limited cell-cycle dependence of the merocyanine 540-sensitized photoinactivation of L1210 leukemia cells.
AuthorsQiu K, Traul DL, Sieber F
JournalPhotochem Photobiol
PubMed ID1502271
'L1210 leukemia cells were synchronized by a double thymidine block technique and then characterized with regard to their susceptibility to merocyanine 540 (MC540)-sensitized photoinactivation. Cells harvested 5 (G2/M phase) h after release from the second thymidine block were most susceptible to MC540-sensitized photoinactivation followed, in order of decreasing sensitivity, by ... More
Phosphatidylserine exposure in B lymphocytes: a role for lipid packing.
AuthorsElliott JI, Sardini A, Cooper JC, Alexander DR, Davanture S, Chimini G, Higgins CF,
JournalBlood
PubMed ID16684961
'Plasma membrane lipids are usually distributed asymmetrically, with phosphatidylserine (PS) confined to the inner leaflet. PS exposure at the outer leaflet occurs early in apoptosis, but it is also constitutive on some nonapoptotic cell populations where it plays a role in cell signaling. How PS is transported ("flopped") to the ... More
Singlet oxygen production and photoisomerization: two competitive processes for merocyanine 540 irradiated with visible light.
AuthorsHoebeke M, Seret A, Piette J, van de Vorst A
JournalJ Photochem Photobiol B
PubMed ID3149292
'The quantum yields of singlet oxygen production by merocyanine 540 have been measured during visible light irradiation performed in methanol and ethanol. These appear to be one hundred times smaller than the quantum yield for rose bengal measured under the same conditions. Flash photolysis experiments demonstrate the ability of merocyanine ... More
Determination of singlet oxygen quantum yields with 1,3-diphenylisobenzofuran in model membrane systems.
AuthorsKrieg M
JournalJ Biochem Biophys Methods
PubMed ID8227944
'The oxidation of 1,3-diphenylisobenzofuran by singlet oxygen was investigated in methanol and in two different types of liposomes. It was found that at high concentrations of scavenger 1,3-diphenylisobenzofuran, e.g., > 100 microM in methanol, the 1:1 oxidation stoichiometry is lost and more than one scavenger molecule per molecule of singlet ... More
Changes in absorption, fluorescence, dichroism, and Birefringence in stained giant axons: : optical measurement of membrane potential.
AuthorsRoss WN, Salzberg BM, Cohen LB, Grinvald A, Davila HV, Waggoner AS, Wang CH
JournalJ Membr Biol
PubMed ID864685
'The absorption, fluorescence, dichroism, and birefringence of stained squid axons were measured during action potentials and voltage clamp steps in an effort to find large optical signals that could be used to monitor membrane potential. Changes in all four optical properties were found that were linearly related to membrane potential ... More
Internal and external application of photodynamic sensitizers on squid giant axons.
AuthorsOxford GS, Pooler JP, Narahashi T
JournalJ Membr Biol
PubMed ID903963
'Squid giant axons were photosensitized by dyes applied internally or externally in air saturated solutions and photochemically modified by visible light. For most dyes the modifications included an irreversible block of sodium channels, a destruction of inactivation in some of the unblocked channels, and a slowing of inactivation. Internal application ... More
Mechanism of photosensitization of glioblastoma and neuroblastoma cells by merocyanine 540: a lipid peroxidation study.
AuthorsSharma M, Joshi PG, Joshi NB
JournalIndian J Biochem Biophys
PubMed ID9491648
'Mechanism of merocyanine 540 (MC540) mediated photosensitization in glioblastoma (U-87MG) and neuroblastoma (Neuro 2a) cells was investigated. Photoinduced lipid peroxidation was measured in the presence of mechanistic probes-deuterium oxide (D2O), sodium azide, superoxide dismutase (SOD), mannitol and sodium benzoate. In both the types of cells, the photoinduced lipid peroxidation was ... More
Cholesterol-free phospholipid domains may be the membrane feature selected by N epsilon-dansyl-L-lysine and merocyanine 540.
AuthorsHumphries GM, Lovejoy JP
JournalBiochem Biophys Res Commun
PubMed ID6404276
'We have used N epsilon-dansyl-L-lysine as a fluorescent membrane probe, to study cells taken from tissues concerned with immune function. There is a striking similarity between the staining selectivity of this compound and that reported by others for merocyanine 540. Both compounds stain leukemic, human, peripheral leukocytes, an erythroleukemia line, ... More
Photodynamic action of merocyanine 540 in artificial bilayers and natural membranes: action spectra and quantum yields.
AuthorsSingh RJ, Feix JB, Pintar TJ, Girotti AW, Kalyanaraman B
JournalPhotochem Photobiol
PubMed ID1857744
'The action spectra and quantum yields for singlet oxygen (1O2) generation by merocyanine 540 (MC540) in liposomes and isolated erythrocyte membranes were obtained using electron spin resonance techniques. Oxygen consumption was measured by spin label oximetry in the presence of histidine for fully-saturated dimyristoylphosphatidylcholine vesicles, mono-unsaturated 1-palmitoyl-2-oleoylphosphatidylcholine vesicles and erythrocyte ... More
A large change in axon fluorescence that provides a promising method for measuring membrane potential.
AuthorsDavila HV, Salzberg BM, Cohen LB, Waggoner AS
JournalNat New Biol
PubMed ID4512623
Merocyanine 540.
AuthorsSieber F
JournalPhotochem Photobiol
PubMed ID3325998
Dye laser intracavity absorption as an optical probe in condensed phase and biological systems.
AuthorsGiniger R, Gutman M
JournalPhotochem Photobiol
PubMed ID4011699
The photophysics of merocyanine 540. A comparative study in ethanol and in liposomes.
AuthorsAramendia PF, Krieg M, Nitsch C, Bittersmann E, Braslavsky SE
AuthorsSchlegel RA, Reed JA, McEvoy L, Algarin L, Williamson P
JournalMethods Enzymol
PubMed ID3695965
The acute intravenous toxicity of biological stains, dyes, and other fluorescent substances.
AuthorsLutty GA
JournalToxicol Appl Pharmacol
PubMed ID79242
Dye indicators of membrane potential.
AuthorsWaggoner AS
JournalAnnu Rev Biophys Bioeng
PubMed ID383007
Kinetics of the association of potential-sensitive dyes with model and energy-transducing membranes: implications for fast probe response times.
AuthorsSmith JC, Frank SJ, Bashford CL, Chance B, Rudkin B
JournalJ Membr Biol
PubMed ID7401166
Applications of dye-sensitized photoreactions in neurobiology.
AuthorsSpikes JD
JournalPhotochem Photobiol
PubMed ID1775530
Potential-sensitive molecular probes in membranes of bioenergetic relevance.
AuthorsSmith JC
JournalBiochim Biophys Acta
PubMed ID2178682
The use of optical probes to monitor membrane potential.
AuthorsBashford CL, Smith JC
JournalMethods Enzymol
PubMed ID459857
Optical measurement of membrane potential in cells, organelles, and vesicles.
AuthorsFreedman JC, Novak TS
JournalMethods Enzymol
PubMed ID2747524
Selective killing of leukemic cells by merocyanine 540-mediated photosensitization.
AuthorsSieber F, Spivak JL, Sutcliffe AM
JournalProc Natl Acad Sci U S A
PubMed ID6594700
In vitro incubation of leukemic bone marrow with the lipophilic fluorescent dye merocyanine 540 and simultaneous exposure to light reduced the concentration of L1210 leukemia cells by about 5 orders of magnitude but spared enough normal pluripotent hematopoietic stem cells to allow hematopoietic reconstitution of lethally irradiated syngeneic mice. This ... More
Imaging membrane potential with voltage-sensitive dyes.
AuthorsZochowski M, Wachowiak M, Falk CX, Cohen LB, Lam YW, Antic S, Zecevic D
JournalBiol Bull
PubMed ID10707808
Membrane potential can be measured optically using a variety of molecular probes. These measurements can be useful in studying function at the level of an individual cell, for determining how groups of neurons generate a behavior, and for studying the correlated behavior of populations of neurons. Examples of the three ... More
Photooxidation products of merocyanine 540 formed under preactivation conditions for tumor therapy.
AuthorsFranck B, Schneider U
JournalPhotochem Photobiol
PubMed ID1502270
In order to gain insight into the preactivation of merocyanine 540 (MC540) 1 for the photodynamic therapy (Gulliya et al., 1990a, Photochem. Photobiol. 52, 831-838) its photo-oxidation was investigated. After irradiation of MC540 1 on a preparative scale three main photodegradation products were isolated with 16-20% yields. They turned out ... More
Dye-mediated photolysis of human neuroblastoma cells: implications for autologous bone marrow transplantation.
AuthorsSieber F, Rao S, Rowley SD, Sieber-Blum M
JournalBlood
PubMed ID3521764
Cells from three different human neuroblastoma cell lines and normal human bone marrow cells were exposed to the lipophilic fluorescent dye, merocyanine 540 (MC 540), and white light. In vitro clonogenic tumor cells were inactivated up to 25,000 times more rapidly than multipotent hematopoietic progenitor cells (CFU-GEMM). It is conceivable ... More
Spectral properties of fluorescent dyes in lecithin vesicles. Probes for the structure of lipid bilayer membranes and for membrane potentials.
AuthorsPohl GW
JournalZ Naturforsch [C]
PubMed ID136128
Three fluorescent dyes (a merocyanin, a cyanin and a modified umbeliferon) have been incorporated into vesicles from three different lecithins. Their absorption spectrum, emission spectrum and fluorescence polarization in the lipid vesicles has been studied and compared with the spectral properties in homogeneous organic solutions. The reactivity of lipid bound ... More
Triplet yield of merocyanine 540 in water is wavelength dependent.
AuthorsSeret A, Hoebeke M, Van de Vorst A
JournalPhotochem Photobiol
PubMed ID2284351
Monomers and aggregates of Merocyanine 540 (MC540) in water are able to photoisomerize. The shape of the photoisomer absorption spectrum is very similar to that of the ground state. Triplet state of MC540 in water has been produced by energy transfer from triplet anthracene and displays a broad absorption spectrum ... More
Virucidal activity of pure singlet oxygen generated by thermolysis of a water-soluble naphthalene endoperoxide.
AuthorsDewilde A, Pellieux C, Hajjam S, Wattré P, Pierlot C, Hober D, Aubry JM
JournalJ Photochem Photobiol B
PubMed ID8988609
Using the water-soluble naphthalene carrier of singlet oxygen NDPO2, we have shown that pure singlet oxygen is able to inactivate enveloped viruses (human immunodeficiency virus type 1, herpes simplex virus type 1, cytomegalovirus, vesicular stomatitis virus), but has no effect on non-enveloped viruses (adenovirus and poliovirus 1). These results are ... More
Usefulness of MC-540 fluorescent dye as probe versus scanning electron microscopy for assessing membrane changes.
AuthorsAgarwal S, Khardori R, Agarwal SS
JournalToxicol Lett
PubMed ID2260114
The effect of primaquine enantiomers on cell membranes of glucose-6-phosphate (G-6PD)-deficient erythrocytes was studied in vitro. Staining with merocyanine (Mc-540) showed that exposure to primaquine enantiomers produces significant fluorescence in G-6PD-deficient erythrocytes, indicating marked drug-induced alterations in membrane fluidity. Scanning electron microscopy (SEM) studies confirmed that primaquine enantiomers altered membrane ... More
Modulation by thiols of the merocyanine 540-sensitized photolysis of leukemia cells, red cells, and herpes simplex virus type 1.
AuthorsGaffney DK, O'Brien JM, Sieber F
JournalPhotochem Photobiol
PubMed ID1851305
This paper reports on the role of endogenous and exogenous thiols in the merocyanine 540 (MC 540)-sensitized photoirradiation of L1210 leukemia cells, human erythrocytes, and human Herpes simplex virus type 1. Several measures taken to decrease the intracellular content of glutathione enhanced the cells' sensitivity to MC 540-sensitized photoirradiation while ... More
Electrostatic interaction between merocyanine 540 and liposomal and mitochondrial membranes.
AuthorsAiuchi T, Kobatake Y
JournalJ Membr Biol
PubMed ID458842
The fluorescence of merocyanine 540 (MC) in liposomal and mitochondrial suspensions was measured under various conditions. Under a given condition, both the amount of dye bound to the membrane and the zeta potential were determined simultaneously. It was found that the fluorescence intensity was proportional to the amount of bound ... More
Ionizing radiation-inducible apoptosis in the absence of p53 linked to transcription factor EGR-1.
AuthorsAhmed MM, Sells SF, Venkatasubbarao K, Fruitwala SM, Muthukkumar S, Harp C, Mohiuddin M, Rangnekar VM
JournalJ Biol Chem
PubMed ID9407088
The tumor suppressor protein p53 is a pivotal regulator of apoptosis, and prostate cancer cells that lack p53 protein are moderately resistant to apoptotic death by ionizing radiation. Genes encoding the transcription factor early growth response-1 (EGR-1) and cytokine tumor necrosis factor-alpha (TNF-alpha) were induced upon irradiation of prostate cancer ... More
'Photo-degeneration' of neurones after extracellular dye application.
AuthorsPicaud S, Wunderer HJ, Franceschini N
JournalNeurosci Lett
PubMed ID3226611
Irradiation in the presence of a dye applied to the extracellular space was found to trigger neuronal degeneration in fly photoreceptor neurones. This phenomenon endowed the selected cells with a dark and fine-grained label such that they could be traced and scrutinized for synaptic specializations. It also initiated their phagocytotic ... More
Metabolic effects of some electrofluorimetric dyes.
AuthorsKinnally KW, Tedeschi H
JournalBiochim Biophys Acta
PubMed ID687611
The effect of five electrofluorimetric dyes on mitochondrial metabolism was examined to determine their suitability for mitochondrial studies and other biological uses. The dyes merocyanine 540, 8-anilino-1-naphthalene sulfonic acid and bis(1,3-dibutyl barbituric acid-(5))-pentamethane oxonol were found to be inhibitors of the respiratory chain. However, the first two exerted their effect ... More
AuthorsSchlegel RA, Stevens M, Lumley-Sapanski K, Williamson P
JournalImmunol Lett
PubMed ID8370600
To test whether apoptotic thymocytes can be identified by altered packing of lipids in their plasma membranes, thymocytes were isolated from mice injected with hydrocortisone and stained with merocyanine 540 (MC540), a fluorescent probe sensitive to lipid packing. At 9-10 h after injection, a subpopulation of H2-Klo cells with increased ... More
A study of the binding of merocyanine 540 to myeloid leukemia M1 cells using an intensified charge-coupled device for fluorescence imaging microscopy.
The binding of merocyanine 540 (MC540) to murine myeloid leukemia (M1) cells and normal erythrocytes was measured by fluorescence digital imaging microscopy using an intensified charge-coupled device. It was found that, on average, about three times more MC540 were bound to a unit membrane area of M1 cells than erythrocytes, ... More
Photodynamic action of merocyanine 540 on artificial and natural cell membranes: involvement of singlet molecular oxygen.
AuthorsKalyanaraman B, Feix JB, Sieber F, Thomas JP, Girotti AW
JournalProc Natl Acad Sci U S A
PubMed ID3033673
The photochemistry of merocyanine 540 (MC 540), a sensitizing dye that binds preferentially to leukemia and electrically excitable cells, has been investigated. MC 540-mediated photooxidation of histidine, arachidonate, and unsaturated phospholipid vesicles was assessed by spin label oximetry and shown to involve type II (singlet oxygen) chemistry. The dye was ... More
Increased membrane permeability of apoptotic thymocytes: a flow cytometric study.
We have recently developed a method for the separation and quantification of viable apoptotic cells without the need for permeabilisation or fixation of the cells. The method is based on the observation that apoptotic rat thymocytes fluoresce more brightly than normal cells after a brief incubation with the DNA binding ... More