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1
Hsiao, L. L., R. J. Howard, M. Aikawa, and T. F. Taraschi. "Modification of host cell membrane lipid composition by the intra-erythrocytic human malaria parasite Plasmodium falciparum." Biochemical Journal 274, no. 1 (February 15, 1991): 121–32. http://dx.doi.org/10.1042/bj2740121.
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The phospholipid and fatty acid compositions of the host infected erythrocyte plasma membrane (IEPM) have been determined for erythrocytes infected with the human malaria parasite Plasmodium falciparum. IEPM were prepared by selective lysis of the host erythrocyte (but not of the parasite membranes) with 0.1% saponin, followed by differential centrifugation. The purity of the IEPM was determined by measuring the membrane-specific enzyme markers acetylcholinesterase, glutamate dehydrogenase and lactate dehydrogenase, and by immunoelectron microscopy using monoclonal antibodies specific for human erythrocyte glycophorin A (4E7) and for a 195 kDa parasite membrane glycoprotein (Pf6 3B10.1). Both approaches demonstrated that the host erythrocyte plasma membrane preparation was free from contamination by parasite membranes. During intra-erythrocytic development of the parasite, the phospholipid composition of the erythrocyte membrane was strikingly altered. IEPM contained more phosphatidylcholine (38.7% versus 31.7%) and phosphatidylinositol (2.1% versus 0.8%) and less sphingomyelin (14.6% versus 28.0%) than normal uninfected erythrocytes. Similar alterations in phospholipid composition were determined for erythrocyte membranes of parasitized cells isolated by an alternative method utilizing polycationic polyacrylamide microbeads (Affigel 731). The total fatty acid compositions of the major phospholipids in IEPM were determined by g.l.c. The percentage of polyunsaturated fatty acids in normal erythrocyte phospholipids (39.4%) was much higher than in phospholipids from purified parasites (23.3%) or IEPM (24.0%). The unsaturation index of phospholipids in IEPM was considerably lower than in uninfected erythrocytes (107.5 versus 161.0) and was very similar to that in purified parasites (107.5 versus 98.5). Large increases in palmitic acid (C16:0) (from 21.88% to 31.21%) and in oleic acid (C18:1) (from 14.64% to 24.60%), and major decreases in arachidonic acid (C20:4) (from 17.36% to 7.85%) and in docosahexaenoic acid (C22:6) (from 4.34% to 1.8%) occurred as a result of infection. The fatty acid profiles of individual phospholipid classes from IEPM resembled in many instances the fatty acid profiles of parasite phospholipids rather than those of uninfected erythrocytes. Analysis of IEPM from P. falciparum-infected erythrocytes (trophozoite stage) revealed that, during intra-erythrocytic maturation of the parasite, the host erythrocyte phospholipid composition was markedly refashioned. These alterations were not dependent on the method used to isolate the IEPM, with similar results obtained using either a saponin-lysis method or binding to Affigel beads. Since mature erythrocytes have negligible lipid synthesis and metabolism, these alterations must occur as a result of parasite-directed metabolism of erythrocyte lipids and/or trafficking of lipids between the parasite and erythrocyte membranes.
2
Murakami, K., and K. Tanabe. "An antigen of Plasmodium yoelii that translocates into the mouse erythrocyte membrane upon entry into the host cell." Journal of Cell Science 73, no. 1 (February 1, 1985): 311–20. http://dx.doi.org/10.1242/jcs.73.1.311.
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Monoclonal antibodies against the rodent malaria parasite, Plasmodium yoelii, have been prepared and characterized by indirect immunofluorescence on acetone-fixed infected mouse erythrocytes. The antibody of clone K2 reacted strongly with late trophozoites and schizonts, whereas it did so weakly and diffusely with ring forms and early trophozoites. Strong fluorescence was confined to granular structures in schizonts and merozoites. Parasites that invaded erythrocytes in vitro lost the strong fluorescence. Instead, immunofluorescence appeared in the membranes of erythrocytes infected in vitro with merozoites. Erythrocytes infected with more than one merozoite had intensified immunofluorescence in their membranes. Staining of the invaded erythrocytes with 4′,6-diamidino-2-phenylindole (DAPI) hydrochloride demonstrated that membranes of all the invaded erythrocytes acquired the P. yoelii antigen. These results suggest that the P. yoelii antigen in merozoites is translocated into erythrocyte membranes upon entry into the host cell. Immunofluorescence continued to appear in membranes of infected erythrocytes throughout the intra-erythrocytic parasite growth. Staining of unfixed infected erythrocytes with the K2 antibody failed to detect the parasite antigen. In contrast, immunofluorescence was present in unfixed membranes of erythrocyte ghosts, which had been spontaneously formed after rupture of schizont-infected erythrocytes by merozoite release. No immunofluorescence appeared in either acetone-fixed or unfixed ghosts of normal erythrocytes. These results suggest the antigenic determinant of the P. yoelii antigen is exposed at the cytoplasmic surface of the infected erythrocyte membrane. Immunoprecipitation has revealed that the K2 antibody recognizes a 160 X 10(3) Mr P. yoelii antigen.
3
Nunes-Correia, Isabel, João Ramalho-Santos, and Maria C. Pedroso de Lima. "Sendai Virus Fusion Activity as Modulated by Target Membrane Components." Bioscience Reports 18, no. 2 (April 1, 1998): 59–68. http://dx.doi.org/10.1023/a:1020180109275.
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We have studied the differences between erythrocytes and erythrocyte ghosts as target membranes for the study of Sendai virus fusion activity. Fusion was monitored continuously by fluorescence dequenching of R18-labeled virus. Experiments were carried out either with or without virus/target membrane prebinding. When Sendai virus was added directly to a erythrocyte/erythrocyte ghost suspension, fusion was always lower than that obtained when experiments were carried out with virus already bound to the erythrocyte/erythrocyte ghost in the cold, since with virus prebinding fusion can be triggered more rapidly. Although virus binding to both erythrocytes and erythrocyte ghosts was similar, fusion activity was much more pronounced when erythrocyte ghosts were used as target membranes. These observations indicate that intact erythrocytes and erythrocyte ghosts are not equivalent as target membranes for the study of Sendai virus fusion activity. Fusion of Sendai virus with both target membranes was inhibited when erythrocytes or erythrocyte ghosts were pretreated with proteinase K, suggesting a role of target membrane proteins in this process. Treatment of both target membranes with neuraminidase, which removes sialic acid residues (the biological receptors for Sendai virus) greatly reduced viral binding. Interestingly, this treatment had no significant effect on the fusion reaction itself.
4
Campanella, M. Estela, Haiyan Chu, Nancy J. Wandersee, Luanne L. Peters, Narla Mohandas, Diana M. Gilligan, and Philip S. Low. "Characterization of glycolytic enzyme interactions with murine erythrocyte membranes in wild-type and membrane protein knockout mice." Blood 112, no. 9 (November 1, 2008): 3900–3906. http://dx.doi.org/10.1182/blood-2008-03-146159.
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Previous research has shown that glycolytic enzymes (GEs) exist as multienzyme complexes on the inner surface of human erythrocyte membranes. Because GE binding sites have been mapped to sequences on the membrane protein, band 3, that are not conserved in other mammalian homologs, the question arose whether GEs can organize into complexes on other mammalian erythrocyte membranes. To address this, murine erythrocytes were stained with antibodies to glyceraldehyde-3-phosphate dehydrogenase, aldolase, phosphofructokinase, lactate dehydrogenase, and pyruvate kinase and analyzed by confocal microscopy. GEs were found to localize to the membrane in oxygenated erythrocytes but redistributed to the cytoplasm upon deoxygenation, as seen in human erythrocytes. To identify membrane proteins involved in GE assembly, erythrocytes from mice lacking each of the major erythrocyte membrane proteins were examined for GE localization. GEs from band 3 knockout mice were not membrane associated but distributed throughout the cytoplasm, regardless of erythrocyte oxygenation state. In contrast, erythrocytes from mice lacking α-spectrin, ankyrin, protein 4.2, protein 4.1, β-adducin, or dematin headpiece exhibited GEs bound to the membrane. These data suggest that oxygenation-dependent assembly of GEs on the membrane could be a general phenomenon of mammalian erythrocytes and that stability of these interactions depends primarily on band 3.
5
Nardid, O., S. Repina, E. Bobrova, Yu Govorova, S. Narozhnyi, and E. Rozanova. "Beneficial impact of human placenta extracts on erythrocyte membrane thermostability." Trakia Journal of Sciences 16, no. 3 (2018): 204–11. http://dx.doi.org/10.15547/tjs.2018.03.006.
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PURPOSE: To study the influence of human placenta extract (HPE) and its individual fractions on the thermal stability of human erythrocyte membrane. METHODS: HPE fractions were isolated by gel chromatography. Thermal hemolysis of erythrocytes, exposed to 55°C was measured spectrophotometrically. Cytosol microvscosity and barrier function of erythrocyte membranes at hyperthermia were investigated by EPR spin probe TEMPON. Thermal denaturation of erythrocyte membrane proteins were studied by differential scanning calorimetry. RESULTS: Pre-treatment of erythrocytes with HPE or its fractions inhibited thermal hemolysis. Low-molecular fractions (below 4 kDa and 12-20 kDa) were the most effective in thermal hemolysis inhibition ((31.7±3.3) % and (31.5±3.2) %, respectively). The latter fractions markedly reduced the hyperthermia (55°C)-induced permeability of erythrocytes for ferricyanide ions and inhibited the thermo-induced structural transitions in erythrocyte membrane between 40 and 50°C, which are associated with cytoskeletal proteins. HPE fractions reversibly increased the denaturation temperatures of erythrocyte membrane proteins, except that of spectrin, and enlarged the enthalpy of denaturation of all membrane proteins. CONCLUSIONS: HPE and its individual fractions increased the thermal stability of erythrocyte membranes and erythrocytes. This effect was attributed to the reversible binding of some low molecular ingredient of HPE to the integral proteins and consequent stabilization of their interaction with under-membrane cytoskeleton.
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Naparlo, Katarzyna, Grzegorz Bartosz, Ireneusz Stefaniuk, Bogumil Cieniek, Miroslaw Soszynski, and Izabela Sadowska-Bartosz. "Interaction of Catechins with Human Erythrocytes." Molecules 25, no. 6 (March 24, 2020): 1456. http://dx.doi.org/10.3390/molecules25061456.
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The aim of this study was to characterize the interaction of chosen catechins ((+)-catechin, (−)-epigallocatechin (EGC), and (−)-epigallocatechin gallate (EGCG)) with human erythrocytes and their protective effects against oxidative damage of erythrocytes. Uptake of the catechins by erythrocytes was studied by fluorimetry, their interaction with erythrocyte membrane was probed by changes in erythrocyte osmotic fragility and in membrane fluidity evaluated with spin labels, while protection against oxidative damage was assessed by protection against hemolysis induced by permanganate and protection of erythrocyte membranes against lipid peroxidation and protein thiol group oxidation. Catechin uptake was similar for all the compounds studied. Accumulation of catechins in the erythrocyte membrane was demonstrated by the catechin-induced increase in osmotic resistance and rigidification of the erythrocyte membrane detected by spin labels 5-doxyl stearic acid and 16-doxyl stearic acid. (−)-Epigallocatechin and EGCG inhibited erythrocyte acetylcholinesterase (mixed-type inhibition). Catechins protected erythrocytes against permanganate-induced hemolysis, oxidation of erythrocyte protein thiol groups, as well as membrane lipid peroxidation. These results contribute to the knowledge of the beneficial effects of catechins present in plant-derived food and beverages.
7
Walker, Britta, Syeda T. Towhid, Evi Schmid, Sascha M. Hoffmann, Majed Abed, Patrick Münzer, Sebastian Vogel, et al. "Dynamic adhesion of eryptotic erythrocytes to immobilized platelets via platelet phosphatidylserine receptors." American Journal of Physiology-Cell Physiology 306, no. 3 (February 1, 2014): C291—C297. http://dx.doi.org/10.1152/ajpcell.00318.2013.
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Glucose depletion of erythrocytes triggers suicidal erythrocyte death or eryptosis, which leads to cell membrane scrambling with phosphatidylserine exposure at the cell surface. Eryptotic erythrocytes adhere to endothelial cells by a mechanism involving phosphatidylserine at the erythrocyte surface and CXCL16 as well as CD36 at the endothelial cell membrane. Nothing has hitherto been known about an interaction between eryptotic erythrocytes and platelets, the decisive cells in primary hemostasis and major players in thrombotic vascular occlusion. The present study thus explored whether and how glucose-depleted erythrocytes adhere to platelets. To this end, adhesion of phosphatidylserine-exposing erythrocytes to platelets under flow conditions was examined in a flow chamber model at arterial shear rates. Platelets were immobilized on collagen and further stimulated with adenosine diphosphate (ADP, 10 μM) or thrombin (0.1 U/ml). As a result, a 48-h glucose depletion triggered phosphatidylserine translocation to the erythrocyte surface and augmented the adhesion of erythrocytes to immobilized platelets, an effect significantly increased upon platelet stimulation. Adherence of erythrocytes to platelets was blunted by coating of erythrocytic phosphatidylserine with annexin V or by neutralization of platelet phosphatidylserine receptors CXCL16 and CD36 with respective antibodies. In conclusion, glucose-depleted erythrocytes adhere to platelets. The adhesive properties of platelets are augmented by platelet activation. Erythrocyte adhesion to immobilized platelets requires phosphatidylserine at the erythrocyte surface and CXCL16 as well as CD36 expression on platelets. Thus platelet-mediated erythrocyte adhesion may foster thromboocclusive complications in diseases with stimulated phosphatidylserine exposure of erythrocytes.
8
Murali, J., D. Koteeswari, J. M. Rifkind, and R. Jayakumar. "Amyloid insulin interaction with erythrocytes." Biochemistry and Cell Biology 81, no. 1 (January 1, 2003): 51–59. http://dx.doi.org/10.1139/o03-009.
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Erythrocyte membrane interactions with insulin fibrils (amyloid) have been investigated using centrifugation, fluorescence spectroscopy, light scattering, and flow cytometric techniques. The results indicate that insulin fibrils are having moderate affinity to erythrocyte membrane. However, analysis of the apparent dissociation constants of human erythrocyte membranes (leaky and resealed vesicles) with amyloid insulin reveal that the insulin binding is drastically reduced on attaining the fibrillar state compared with native insulin. To understand the role of insulin receptors on erythrocytes binding to amyloid, we have studied the interaction of biotinylated forms of denatured and amyloidic insulin with erythrocytes. FITC-streptavidin was used as a counter staining in flow cytometry measurements. We found that insulin fibrils bind 10 times more with erythrocyte membranes than with amylin and denatured insulin.Key words: insulin amyloid, erythrocyte membrane, amyloid binding, flow cytometry, dissociation constant.
9
Sblano, Cesare, Silvia Micelli, and Daniela Meleleo. "Effects of n-Octyl-β-D-Glucopyranoside on Human and Rat Erythrocyte Membrane Stability Against Hemolysis." Open Biology Journal 5, no. 1 (April 11, 2012): 1–5. http://dx.doi.org/10.2174/1874196701205010001.
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The practical importance for the pharmaceutical and cosmetics industries of the interactions between biological membranes and surfactant molecules has led to intensive research within this area. The interactions of non-ionic surfactant n-octyl-β-D-glucopyranoside (OG) with the human and rat erythrocyte membranes were studied. The in vitro hemolytic and antihemolytic activities were determined by employing a method in which both erythrocytes were added to the hypotonic medium containing OG at different concentrations, and the amount of haemoglobin released was determined. noctyl- β-D-glucopyranoside was found to have a biphasic effect on both types of erythrocyte membrane. We also investigated the interactions of OG with the erythrocyte membrane in isotonic medium; the dose-dependent curves show similar behaviour in both human and rat erythrocytes. Our results showed that OG has greater antihemolytic potency on rat than on human erythrocytes; furthermore, rat erythrocytes were more sensitive than human erythrocytes to hypotonic shock. How the different lipoprotein structure of these erythrocytes determines a difference in antihemolytic activity is discussed.
10
Benga, Gheorghe, Anthony Brain, Victor I. Pop, and John Wrigglesworth. "Freeze-fracture Electron Microscopic observations on the effects of sulphydryl group reagents on human erythrocyte membranes." Proceedings, annual meeting, Electron Microscopy Society of America 48, no. 3 (August 12, 1990): 524–25. http://dx.doi.org/10.1017/s0424820100160170.
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The intra-membrane particles (IMPs) observed on the fracture face of frozen erythrocyte membranes are thought to correspond primarily to “band 3” tetramers or dimers. Some recent studies correlating the inhibition of water diffusion in erythrocytes by p-chloromercuribenzene sulfonate (PCMBS) with the binding of 203Hg to erythrocyte membrane proteins has enabled band 3 and the polypeptides in band 4.5 to be identified as the proteins associated with the channels for water permeation in human erythrocytes. A further characterization of the effects of the incubation of human erythrocyte membranes with PCMBS and N-ethylmaleimide (NEM) has been performed as previously described. Experimental conditions have been previously described.A comparison was made of the appearance of freeze-etched membranes of control erythrocytes and erythrocytes with the sulphydryl reagents. It was found that on many of the control and NEM-treated cells, small (50-100 nm) elevated patches could be seen (Fig. 1, 2 and 3). These are present on both fracture and etch faces and are devoid of any intramembrane particles. The patch elevations were never observed in the membranes of PCMBS-treated cells (Fig. 4).
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Ajdžanović, Vladimir, Ivan Spasojević, Jasmina Pantelić, Branka Šošić-Jurjević, Branko Filipović, Verica Milošević, and Walter Severs. "Vitex Agnus-Castus L. Essential Oil Increases Human Erythrocyte Membrane Fluidity." Journal of Medical Biochemistry 31, no. 3 (July 1, 2012): 222–27. http://dx.doi.org/10.2478/v10011-011-0055-x.
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Vitex Agnus-CastusL. Essential Oil Increases Human Erythrocyte Membrane FluidityErythrocyte membrane fluidity is related to their rheologic behavior, the dynamic quality of erythrocytes, which is tempted in hypertension and atherosclerosis. An increased risk of these and other cardiovascular diseases occurs in ageing women. Menopause-related conditions are often treated with hormone replacement therapy that may increase the risk of malignancies.Vitex agnus-castusL. essential oil contains various organic compounds (monoterpenes, sesquiterpenes and terpenoids), and is increasingly used as an alternative therapy for menopausal symptoms. These components of the oil may be incorporated into cell membranes, thereby changing the membrane fluidity. The aim of this study was to determine the effects ofVitex agnus-castusessential oil on human erythrocyte membrane fluidity at graded depths. We used Electron Paramagnetic Resonance spectroscopy and fatty acid spin probes (5-doxyl stearic acid and 12-doxyl stearic acid), whose spectra depend on membrane fluidity. After treatment withVitex agnus-castusessential oil the erythrocytes had a significant (p=0.029) and reversible increase in membrane fluidity in the deeper hydrophobic membrane regions, with no change (p>0.05) in fluidity near the membrane's hydrophilic surface. These results document increased fluidity of the human erythrocyte membrane byVitex agnus-castusessential oil, and this action may be useful in patients with menopause-related hypertension and other cardiovascular conditions.
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Fukuda, MN, G. Klier, J. Yu, and P. Scartezzini. "Anomalous clustering of underglycosylated band 3 in erythrocytes and their precursor cells in congenital dyserythropoietic anemia type II." Blood 68, no. 2 (August 1, 1986): 521–29. http://dx.doi.org/10.1182/blood.v68.2.521.521.
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Abstract Congenital dyserythropoietic anemia type II (CDA II or HEMPAS) is a genetic anemia caused by membrane abnormality. Our previous studies indicated that in HEMPAS, erythrocytes band 3 and band 4.5 are not glycosylated by polylactosaminoglycans. The present study was aimed at determining how such underglycosylated band 3 behaves in erythrocyte membranes. By using anti-band 3 antibodies, immunogold electron microscopy revealed that band 3s are clustered in HEMPAS erythrocyte membranes. By freeze-fracture electron microscopy, band 3s were also seen as lightly clumped intramembrane particles on a protoplasmic fracture face. Erythrocyte precursor cells stained by anti-band 3 antibodies showed that band 3s are present in the cytoplasmic area of the reticulocytes as scattered single particles. However, in young erythrocytes in which intracellular membranes are almost degenerated, band 3s were clustered in the cytoplasmic area of the cell. These observations suggest that band 3s cluster before they are incorporated into the plasma membranes of HEMPAS erythrocytes. In contrast to band 3, glycophorin A detected by anti-glycophorin A antibodies did not show a noticeable difference between normal and HEMPAS. Such a clustering of band 3 may cause abnormal localization of band 3-associated proteins and may thus result in the macroscopic membrane abnormality seen in HEMPAS erythrocytes.
13
Fukuda, MN, G. Klier, J. Yu, and P. Scartezzini. "Anomalous clustering of underglycosylated band 3 in erythrocytes and their precursor cells in congenital dyserythropoietic anemia type II." Blood 68, no. 2 (August 1, 1986): 521–29. http://dx.doi.org/10.1182/blood.v68.2.521.bloodjournal682521.
Full textAbstract:
Congenital dyserythropoietic anemia type II (CDA II or HEMPAS) is a genetic anemia caused by membrane abnormality. Our previous studies indicated that in HEMPAS, erythrocytes band 3 and band 4.5 are not glycosylated by polylactosaminoglycans. The present study was aimed at determining how such underglycosylated band 3 behaves in erythrocyte membranes. By using anti-band 3 antibodies, immunogold electron microscopy revealed that band 3s are clustered in HEMPAS erythrocyte membranes. By freeze-fracture electron microscopy, band 3s were also seen as lightly clumped intramembrane particles on a protoplasmic fracture face. Erythrocyte precursor cells stained by anti-band 3 antibodies showed that band 3s are present in the cytoplasmic area of the reticulocytes as scattered single particles. However, in young erythrocytes in which intracellular membranes are almost degenerated, band 3s were clustered in the cytoplasmic area of the cell. These observations suggest that band 3s cluster before they are incorporated into the plasma membranes of HEMPAS erythrocytes. In contrast to band 3, glycophorin A detected by anti-glycophorin A antibodies did not show a noticeable difference between normal and HEMPAS. Such a clustering of band 3 may cause abnormal localization of band 3-associated proteins and may thus result in the macroscopic membrane abnormality seen in HEMPAS erythrocytes.
14
Jakuš, Vladimír, Uwe Fuhr, Wolfgang Wörner, and Norbert Rietbrock. "Erythrocyte Membrane Fluidity in Diabetics: Fluorescence Study." Collection of Czechoslovak Chemical Communications 64, no. 3 (1999): 548–52. http://dx.doi.org/10.1135/cccc19990548.
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Erythrocyte membrane fluidity is changed in diabetic subjects with long-term complications. As membrane fluidity indicator, the mean steady-state fluorescence anisotropy was measured in 1,6-diphenylhexa-1,3,5-triene labelled erythrocyte membranes prepared from six control healthy donors and six poorly controlled diabetic subjects. Fluorescence anisotropy values of membranes prepared from erythrocytes of diabetic subjects were significantly higher than in control subjects. This indicates a decreased fluidity of membranes prepared from diabetic subjects. The decreased fluidity of diabetic membranes was raised by glycation inhibitors - penicillamine, captopril, and lipoic acid.
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Yadavalli, Raghavendra, John W. Peterson, Judith A. Drazba, and Tobili Y. Sam-Yellowe. "Trafficking and Association of Plasmodium falciparum MC-2TM with the Maurer’s Clefts." Pathogens 10, no. 4 (April 5, 2021): 431. http://dx.doi.org/10.3390/pathogens10040431.
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In this study, we investigated stage specific expression, trafficking, solubility and topology of endogenous PfMC-2TM in P. falciparum (3D7) infected erythrocytes. Following Brefeldin A (BFA) treatment of parasites, PfMC-2TM traffic was evaluated using immunofluorescence with antibodies reactive with PfMC-2TM. PfMC-2TM is sensitive to BFA treatment and permeabilization of infected erythrocytes with streptolysin O (SLO) and saponin, showed that the N and C-termini of PfMC-2TM are exposed to the erythrocyte cytoplasm with the central portion of the protein protected in the MC membranes. PfMC-2TM was expressed as early as 4 h post invasion (hpi), was tightly colocalized with REX-1 and trafficked to the erythrocyte membrane without a change in solubility. PfMC-2TM associated with the MC and infected erythrocyte membrane and was resistant to extraction with alkaline sodium carbonate, suggestive of protein-lipid interactions with membranes of the MC and erythrocyte. PfMC-2TM is an additional marker of the nascent MCs.
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Shaw, M. K., and L. G. Tilney. "The entry of Theileria parva merozoites into bovine erythrocytes occurs by a process similar to sporozoite invasion of lymphocytes." Parasitology 111, no. 4 (November 1995): 455–61. http://dx.doi.org/10.1017/s0031182000065951.
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SUMMARYThe entry of Theileria parva merozoites into bovine erythrocytes in vivo is described and compared to sporozoite invasion of lymphocytes. Merozoites make initial contact with erythrocytes with any part of their surface and invasion of the host cell does not require the re-orientation of the apical end of the merozoite towards the surface of the erythrocyte. After the initial attachment the merozoite and host cell membranes form a continual close junction with the two apposed membranes separated by a 6–8 nm gap containing moderately dense material. The progressive circumferential ‘zippering’ of these closely apposed membranes leads to the movement of the parasite into the erythrocyte. The newly internalized merozoite which is completely surrounded by the erythrocyte plasma membrane escapes from this enclosing membrane by a process involving the discharge of at least the rhoptries; whether the merozoite also contain other types of secretory organelles (e.g. micronemes, microspheres or dense bodies) remains to be determined. Morphologically, the events involved in merozoite invasion of erythrocytes are almost identical to the process of sporozoite invasion of lymphocytes but differ significantly from the entry process of the invasive stages of other Apicomplexan parasites.
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Ercolani, L., D. Brown, A. Stuart-Tilley, and S. L. Alper. "Colocalization of GAPDH and band 3 (AE1) proteins in rat erythrocytes and kidney intercalated cell membranes." American Journal of Physiology-Renal Physiology 262, no. 5 (May 1, 1992): F892—F896. http://dx.doi.org/10.1152/ajprenal.1992.262.5.f892.
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Glyceraldehyde-3-phosphate dehydrogenase (EC 1.2.2.12) (GAPDH) is a multifunctional protein that associates with the cytoplasmic face of intact human erythrocyte membranes. This association has been postulated to be critically dependent on the interaction of GAPDH with the highly acidic NH2-terminal domain of the principal integral membrane protein of the erythrocyte plasma membrane, the band 3 anion exchanger (AE1). This domain is not conserved in murine erythrocyte AE1 and is fully deleted in the alternatively spliced AE1 isoform that is expressed in the kidney. The lack of conservation of this domain has been proposed to explain the reported absence of GAPDH association with rodent erythrocyte membranes. To determine whether GAPDH could be associated with AE1 proteins in rodent cell membranes, specific rabbit antibodies to peptide sequences of rat GAPDH and mouse AE1 were used to immunolocalize these proteins in sequential semithin sections of rat erythrocytes and kidney medulla. In rat erythrocytes, GAPDH immunoreactivity was predominantly membrane associated and colocalized with AE1. In the kidney medulla, GAPDH was concentrated in the basolateral membrane of type A intercalated cells, where it colocalized with the alternatively spliced kidney form of AE1. GAPDH immunoreactivity was not detected in the plasma membrane of any other cell type in the kidney, indicating its predominant association with AE1-rich membranes. If this membrane interaction occurs via AE1 binding, then GAPDH must have binding sites in addition to those previously described for such binding in human AE1.
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Jackson, John K., Helen Burt, Wilson Mok, Hassan Salari, Erukulla Ravi Kumar, Hoe-Sup Byun, and Robert Bittman. "A comparison of the lytic properties of two ether-linked lipids, one with and one without antineoplastic activity." Biochemistry and Cell Biology 72, no. 7-8 (July 1, 1994): 297–303. http://dx.doi.org/10.1139/o94-042.
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We have synthesized two ether lipids: 2′-(trimethylammonio)ethyl 4-(hexadecyloxy)-3(S)-methoxybutanephosphonate (compound 1) with antineoplastic activity and a maltosyl derivative (compound 2) without antineoplastic activity. We have compared the antineoplastic activity of these two compounds against WEHI-3B cells with their ability to disrupt the membranes of erythrocytes or neutrophils. Since ether lipids are highly hydrophobic molecules, it is possible that they may exert their cytotoxic action by inducing the nonspecific perturbation of cellular membranes, causing lysis and cell death. Membrane disruption was monitored by the lysis of cells or the change in erythrocyte membrane microviscocity and compared with the effect of detergents (known nonspecific lytic agents). Both compounds 1 and 2 caused the lysis of erythrocytes and neutrophils. The rate of lysis of erythrocytes was comparable to the rate of change of erythrocyte membrane microviscosity caused by both compounds 1 and 2. Both compounds caused the lysis of erythrocytes via a noncolloid osmotic mechanism that displayed features of the lysis caused by detergents at high concentrations.Key words: ether-linked lipids, antineoplastic, lysis, anisotropy.
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Bhalla, Pankaj, and Deepa Agrawal. "Alterations in rat erythrocyte membrane due to hexachlorocyclohexane (technical) exposure." Human & Experimental Toxicology 17, no. 11 (November 1998): 638–42. http://dx.doi.org/10.1177/096032719801701109.
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1 Hexachlorocyclohexane (HCH), an organochlorine pesticide having hydrophobic molecule is known to act on membranes. HCH mediated alterations in erythrocyte membrane occur through disorganization of the lipid bilayer. Therefore the changes in erythrocyte membrane fluidity, osmotic fragility and certain membrane bound enzymes were studied. Administration of HCH (technical) to rats at 5 mg/kg, orally, 5 days a week for 1, 2 and 3 months caused marked increase in erythrocyte membrane fluidity, osmotic fragility anddecreaseinlevelsofNa+, K+-ATPase, acetylcholinesterase in erythrocytes and glutathione in blood. 2 These changes indicate that HCH adversely affects membrane structure and function.
20
Gormley, J. A., R. J. Howard, and T. F. Taraschi. "Trafficking of malarial proteins to the host cell cytoplasm and erythrocyte surface membrane involves multiple pathways." Journal of Cell Biology 119, no. 6 (December 15, 1992): 1481–95. http://dx.doi.org/10.1083/jcb.119.6.1481.
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During the asexual stage of malaria infection, the intracellular parasite exports membranes into the erythrocyte cytoplasm and lipids and proteins to the host cell membrane, essentially "transforming" the erythrocyte. To investigate lipid and protein trafficking pathways within Plasmodium falciparum-infected erythrocytes, synchronous cultures are temporally analyzed by confocal fluorescence imaging microscopy for the production, location and morphology of exported membranes (vesicles) and parasite proteins. Highly mobile vesicles are observed as early as 4 h postinvasion in the erythrocyte cytoplasm of infected erythrocytes incubated in vitro with C6-NBD-labeled phospholipids. These vesicles are most prevalent in the trophozoite stage. An immunofluorescence technique is developed to simultaneously determine the morphology and distribution of the fluorescent membranes and a number of parasite proteins within a single parasitized erythrocyte. Parasite proteins are visualized with FITC- or Texas red-labeled monoclonal antibodies. Double-label immunofluorescence reveals that of the five parasite antigens examined, only one was predominantly associated with membranes in the erythrocyte cytoplasm. Two other parasite antigens localized only in part to these vesicles, with the majority of the exported antigens present in lipid-free aggregates in the host cell cytoplasm. Another parasite antigen transported into the erythrocyte cytoplasm is localized exclusively in lipid-free aggregates. A parasite plasma membrane (PPM) and/or parasitophorous vacuolar membrane (PVM) antigen which is not exported always colocalizes with fluorescent lipids in the PPM/PVM. Visualization of two parasite proteins simultaneously using FITC- and Texas red-labeled 2 degrees antibodies reveals that some parasite proteins are constitutively transported in the same vesicles, whereas other are segregated before export. Of the four exported antigens, only one appears to cross the barriers of the PPM and PVM through membrane-mediated events, whereas the others are exported across the PPM/PVM to the host cell cytoplasm and surface membrane through lipid (vesicle)-independent pathways.
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Hayakawa, Eri H., Seiki Kobayashi, and Hiroyuki Matsuoka. "Physicochemical Aspects of thePlasmodium chabaudi-Infected Erythrocyte." BioMed Research International 2015 (2015): 1–8. http://dx.doi.org/10.1155/2015/642729.
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Membrane electrochemical potential is a feature of the molecular profile of the cell membrane and the two-dimensional arrangement of its charge-bearing molecules.Plasmodiumspecies, the causative agents of malaria, are intracellular parasites that remodel host erythrocytes by expressing their own proteins on erythrocyte membranes. Although various aspects of the modifications made to the host erythrocyte membrane have been extensively studied in some humanPlasmodiumspecies (such asPlasmodium falciparum), details of the structural and molecular biological modifications made to host erythrocytes by nonhumanPlasmodiumparasites have not been studied. We employed zeta potential analysis of erythrocytes parasitized byP. chabaudi, a nonhumanPlasmodiumparasite. From these measurements, we found that the surface potential shift was more negative forP. chabaudi-infected erythrocytes than forP. falciparum-infected erythrocytes. However, electron microscopic analysis of the surface ofP. chabaudi-infected erythrocytes did not reveal any modifications as compared with nonparasitized erythrocytes. These results suggest that differences in the membrane modifications found herein represent unique attributes related to the pathogenesis profiles of the two different malaria parasite species in different host animals and that these features have been acquired through parasite adaptations acquired over long evolutionary time periods.
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Koter, Maria, Ida Franiak, Marlena Broncel, and Julita Chojnowska-Jezierska. "Effects of simvastatin and pravastatin on peroxidation of erythrocyte plasma membrane lipids in patients with type 2 hypercholesterolemia." Canadian Journal of Physiology and Pharmacology 81, no. 5 (May 1, 2003): 485–92. http://dx.doi.org/10.1139/y03-042.
Full textAbstract:
Since hypercholesterolemia directly modifies the composition of erythrocytes plasma membrane, the influence of statins on erythrocytes has been researched. The beneficial effects of statins on clinical events may involve mechanisms that modify endothelial dysfunction, plaque stability, thrombus formation and inflammatory responses. The aim of the study was to evaluate the hypolipemic efficacy and effects of pravastatin and simvastatin on erythrocyte membrane fluidity and damage of erythrocytes in patients with type 2 hypercholesterolemia in comparison with a control group of healthy subjects. The study involved 53 patients affected by type 2 hypercholesterolemia (mean age, 53.3 ± 10.3) with initial total serum cholesterol (TC) levels > 250 mg/dL, LDL-cholesterol (LDL-C) levels > 170 mg/dL, and triglycerides (TG) levels < 400 mg/dL. The control group consisted of 30 healthy individuals (mean age 56.9 ± 6.3). Statins were given for 12 weeks. The dosages for oral administration of simvastatin and pravastatin were 20 mg/day. Laboratory tests were carried out before and after 4 and 12 weeks of the pharmacological treatment. The damage to plasma membrane of erythrocytes was measured on the basis of lipid peroxidation. The fluidity of plasma membrane of erythrocytes was determined by electron paramagnetic resonance (EPR) spectroscopy, using two spin labels: 5-DSA and 16-DSA. The cholesterol level in the membrane of red blood cells was estimated. Simvastatin and pravastatin reduced the total cholesterol concentration and LDL-cholesterol in plasma, as well as the cholesterol concentration in erythrocytes membranes. Hypercholesterolemia induced changes in the basic properties of human erythrocyte plasma membrane, including its fluidity and the intensity of lipid peroxidation. These results indicate that the simvastatin and pravastatin therapy reverses the alteration in the erythrocyte plasma membrane properties.Key words: hypercholesterolemia, cholesterol, erythrocyte, plasma membrane, peroxidation, spin labels, statins.
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Kubow, Stan J., and William J. Bettger. "The mobility and reactivity of maleimide-binding proteins in the rat erythrocyte membrane. Effects of dietary zinc deficiency and incubation with zinc in vitro." Canadian Journal of Physiology and Pharmacology 66, no. 1 (January 1, 1988): 66–71. http://dx.doi.org/10.1139/y88-012.
Full textAbstract:
Erythrocyte ghosts, prepared from rats fed zinc-deficient diets, were analyzed for the mobility of membrane proteins by electron spin resonance spectroscopy of the sulfhydryl-binding spin probe, 4-maleimido-2,2,6,6-tetramethylpiperidine-N-oxyl. Compared with erythrocyte membranes from rats fed zinc-adequate diets ad libitum or pair-fed, erythrocyte membranes from zinc-deficient rats had a significantly increased ratio of weakly immobilized to strongly immobilized probe-binding proteins. This suggests that dietary zinc deficiency causes a conformational change in erythrocyte membrane proteins. Dietary zinc deficiency did not significantly affect N-ethylmaleimide (NEM)-induced thermal sensitivity or NEM-induced mechanical fragility in rat erythrocytes; however, the addition of zinc in vitro to red cells significantly inhibits NEM-induced mechanical fragility.
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Lurie, K. G., J. H. Chin, and B. B. Hoffman. "Decreased membrane fluidity and beta-adrenergic responsiveness in atherosclerotic quail." American Journal of Physiology-Heart and Circulatory Physiology 249, no. 2 (August 1, 1985): H380—H385. http://dx.doi.org/10.1152/ajpheart.1985.249.2.h380.
Full textAbstract:
The effects of increased cholesterol on erythrocyte membrane fluidity and beta-adrenergic function were studied in a quail model of atherosclerosis. Birds fed a cholesterol-supplemented diet developed severe atherosclerosis and hypercholesterolemia after 6 wk. This cholesterol-enriched diet led to a markedly elevated serum cholesterol and a 26% increase in the cholesterol-to-phospholipid ratio in erythrocyte membranes. Electron paramagnetic resonance spectra measured with 5- and 12-doxyl-stearic acid spin-label probes were used to estimate the order of quail erythrocyte membranes. Membrane preparations from cholesterol-fed birds were more highly ordered near the membrane leaflet surface, as well as deeper in the membrane interior, compared with controls. beta-Adrenergic receptor stimulation of adenosine 3',5'-cyclic monophosphate accumulation was blunted in erythrocytes from the hypercholesterolemic quail. There was no change in beta-receptor density or affinity in the cholesterol-enriched membranes. These studies demonstrate that cholesterol incorporation into erythrocyte membranes in vivo is associated with decreased membrane fluidity and decreased beta-adrenergic responsiveness. The atherosclerotic quail may serve as a useful model to further probe the sequelae of hypercholesterolemia on the function of integral membrane proteins.
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Kravets, T. Y., E. A. Stepovaya, T. Yu Koshchevets, N. B. Matyusheva, A. A. Bulanova, O. V. Mukhacheva, and E. A. Ananina. "Erythrocyte membranes in metabolic syndrome." Problems of Endocrinology 55, no. 5 (October 15, 2009): 23–25. http://dx.doi.org/10.14341/probl200955523-25.
Full textAbstract:
The authors discuss results of investigations into the structure and functional status of erythrocyte membranes in patients with metabolic syndrome. It is shown that the pathological process involves not only well known changes in serum lipid metabolism but also highly specialized cells, such as erythrocytes. Specifically, erythrocytes undergo marked disorganization of membranous lipid phase in conjunction with a relative increase of cholesterol fraction and a decrease in phospholipids levels. Analysis of fractional lipid composition in erythrocyte membranes reveals reduced content of phospholipids, sphingomyelin, and phosphatidylcholine coupled to increased content of cholesterol, lysophosphatidylcholine, phosphatidylserine, and phosphatidylethanolamine. It is concluded that disturbances of carbohydrate metabolism in patients with metabolic syndrome aggravate manifestations of the underlying disease.
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Sukhoveev, O. V., Y. B. Burlaka, N. V. Grin, A. I. Vovk, and S. V. Verevka. "STUDIES OF ALTERATIONS OF THE CELLULAR MEMBRANE BARRIER FUNCTION AT LARYNGEAL CANCER." Medical and Clinical Chemistry, no. 1 (May 22, 2021): 5–12. http://dx.doi.org/10.11603/mcch.2410-681x.2021.i1.12101.
Full textAbstract:
Introduction. Cellular membrane barrier alterations lead to metabolic and functional disorders. However, in the case of laryngeal cancer (LC) they are insufficiently studied.
The aim of the study – to learn the nature of the interaction of erythrocyte membranes with introduced spin probes as an indicator of changes in the barrier function of membranes at LC.
Research Methods. Samples of the erythrocyte membranes from 40 patients with LC stages II and III and 20 healthy volunteers were probed by EPR with AdTEMPO test. Microviscosity of erythrocyte membranes was determined by the τeff and the decreasing in RSSI. The content of MWM was identified in the blood plasma and in erythrocyte. The partition coefficient between blood plasma proteins and erythrocyte glycocalyx was calculated. SCEM was evaluated by amount of unabsorbed methylene blue.
Results and Discussion. It was established that LC patient’s endogenous intoxication is characterized by excessive accumulation of the total pool of MWM both in blood plasma and glycocalyx of erythrocyte. SCEM was significantly decreased in samples of both LC stages in comparison to control. The most apparent decline in τeff was observed prior to washing of erythrocytes for 5 min after probe insertion. The deceleration after 60 min was observed only in LC stage II. The value of τeff was at control values levels after washing of erythrocytes of LC stage II 5 min after probe insertion and was significantly reduced in stage III LC in comparison to control. RSSI in samples both stage of patients prior to and after washing of erythrocytes was on average 1.5-fold higher than that of control.
Conclusions. It was established that the LC patient’s endogenous intoxication is characterized by excessive accumulation of the total pool of MWM both in blood plasma and glycocalyx of erythrocytes, activation of catabolic processes in plasma, redistribution of MWM between the pool of erythrocyte proteins, which corresponds to the second stage of endotoxicosis. The reduction of the SCEM is shown, which is a manifestation of pathological changes in the surface functional activity of erythrocyte membranes. The effectiveness of AdTEMPO for the evaluation of microviscosity of erythrocyte membranes in patients with LC was confirmed.
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Good, A. H., J. D. Craik, S. M. Jarvis, F. Y. P. Kwong, J. D. Young, A. R. P. Paterson, and C. E. Cass. "Characterization of monoclonal antibodies that recognize band 4.5 polypeptides associated with nucleoside transport in pig erythrocytes." Biochemical Journal 244, no. 3 (June 15, 1987): 749–55. http://dx.doi.org/10.1042/bj2440749.
Full textAbstract:
Three monoclonal antibodies have been raised against partially purified band 4.5 polypeptides [Steck (1974) J. Cell Biol. 62, 1-19] from pig erythrocyte membranes. The antibodies were capable of binding to both intact pig erythrocytes and protein-depleted membrane preparations and recognized detergent-solubilized polypeptides from adult and neonatal pig erythrocytes that were photolabelled with [G-3H]nitrobenzylthioinosine (NBMPR), a potent specific inhibitor of nucleoside transport. The antibodies did not recognize polypeptides from neonatal pig erythrocytes that were photolabelled with the glucose-transport inhibitor [3H]cytochalasin B. Reactivity with polypeptides of apparent Mr 64,000 [10% (w/v) acrylamide gels] was demonstrated by Western-blot analysis. The antibodies recognized pig band 4.5 polypeptides after prolonged treatment with endoglycosidase F, a finding consistent with reactivity against polypeptide, rather than carbohydrate, determinants. Trypsin digestion of NBMPR-labelled protein-depleted pig erythrocyte membranes generated two labelled polypeptide fragments (Mr 43,000 and 26,000). Two of the antibodies recognized both fragments on Western blots, whereas the third bound to the larger, but not to the smaller, fragment. The antibodies had no significant effect on reversible binding of NBMPR to protein-depleted pig erythrocyte membranes and did not bind to NBMPR-labelled polypeptides in human, rabbit or mouse erythrocytes.
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Frankland, Sarah, Akinola Adisa, Paul Horrocks, Theodore F. Taraschi, Timothy Schneider, Salenna R. Elliott, Stephen J. Rogerson, et al. "Delivery of the Malaria Virulence Protein PfEMP1 to the Erythrocyte Surface Requires Cholesterol-Rich Domains." Eukaryotic Cell 5, no. 5 (May 2006): 849–60. http://dx.doi.org/10.1128/ec.5.5.849-860.2006.
Full textAbstract:
ABSTRACT The particular virulence of the human malaria parasite Plasmodium falciparum derives from export of parasite-encoded proteins to the surface of the mature erythrocytes in which it resides. The mechanisms and machinery for the export of proteins to the erythrocyte membrane are largely unknown. In other eukaryotic cells, cholesterol-rich membrane microdomains or “rafts” have been shown to play an important role in the export of proteins to the cell surface. Our data suggest that depletion of cholesterol from the erythrocyte membrane with methyl-β-cyclodextrin significantly inhibits the delivery of the major virulence factor P. falciparum erythrocyte membrane protein 1 (PfEMP1). The trafficking defect appears to lie at the level of transfer of PfEMP1 from parasite-derived membranous structures within the infected erythrocyte cytoplasm, known as the Maurer's clefts, to the erythrocyte membrane. Thus our data suggest that delivery of this key cytoadherence-mediating protein to the host erythrocyte membrane involves insertion of PfEMP1 at cholesterol-rich microdomains. GTP-dependent vesicle budding and fusion events are also involved in many trafficking processes. To determine whether GTP-dependent events are involved in PfEMP1 trafficking, we have incorporated non-membrane-permeating GTP analogs inside resealed erythrocytes. Although these nonhydrolyzable GTP analogs reduced erythrocyte invasion efficiency and partially retarded growth of the intracellular parasite, they appeared to have little direct effect on PfEMP1 trafficking.
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TUFTS, B. L., R. A. FERGUSON, and R. G. BOUTILIER. "In Vivo and In Vitro Effects of Adrenergic Stimulation on Chloride/Bicarbonate Exchange in Rainbow Trout Erythrocytes." Journal of Experimental Biology 140, no. 1 (November 1, 1988): 301–12. http://dx.doi.org/10.1242/jeb.140.1.301.
Full textAbstract:
In vitro and in vivo experiments were carried out to determine the effect of catecholamines on erythrocytic chloride/bicarbonate exchange in the rainbow trout. A further modified boat assay is described and was used to measure bicarbonate flux through intact erythrocytes. Catecholamines had no significant effect on the bicarbonate flux in vitro. The erythrocytes were sensitive to adrenergic stimulation, however, since the agonists used caused a decrease in the pH gradient across the erythrocyte membrane. Exhaustive exercise was associated with an increase in bicarbonate flux through the intact erythrocytes. The mechanism for this increase is not clear, but it is evidently not adrenergic in origin.
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Schwarz-Benmeir, N., T. Glaser, S. Barnoy, and N. S. Kosower. "Calpastatin in erythrocytes of young and old individuals." Biochemical Journal 304, no. 2 (December 1, 1994): 365–70. http://dx.doi.org/10.1042/bj3040365.
Full textAbstract:
To gain knowledge about the behaviour of calpastatin (the specific inhibitor of the Ca(2+)-dependent thiol protease calpain) in the intact cell, we analysed the inhibitor by specific antibodies and determined its activity in erythrocytes from individuals 20-34 years old (young) and 70-93 years old (old). Differences between old and young in the behaviour of erythrocyte calpastatin were observed. Erythrocytes of old individuals had lower amounts of calpastatin and less calpastatin activity than those of young ones. A difference between old and young was also found in the molecular-mass distribution of calpastatin subunits. Increasing the erythrocyte Ca2+ induced changes in calpastatin in young individuals, rendering it similar to calpastatin in cells of old individuals. When calpastatin (isolated from erythrocytes of a young individual) was added to erythrocyte membranes, the initial binding and subsequent association of calpastatin with the membrane were lower in old than in young individuals. We had previously found that calpain binding and activation were enhanced in erythrocyte membranes from old individuals, along with enhanced degradation of band 3 (a major erythrocyte transmembrane anion-transport protein). The overall results indicate an interaction of calpain with calpastatin in the intact cell. Enhanced activation of erythrocyte calpain and degradation of calpastatin occur under conditions of increased cellular Ca2+ and in cells of the aged.
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Low, Philip S., Estela M. Campanella, William A. Anong, Nancy J. Wandersee, Cheryl A. Hillary, and Athar Chishti. "Characterization of Glycolytic Enzyme Complexes on Murine Erythrocyte Membranes." Blood 104, no. 11 (November 16, 2004): 1571. http://dx.doi.org/10.1182/blood.v104.11.1571.1571.
Full textAbstract:
Abstract Glycolytic enzymes have been recently shown to exist as multi-enzyme complexes in association with the cytoplasmic domain of band 3 at the inner surface of the human erythrocyte membrane. Because several of the glycolytic enzyme binding sites have been mapped to sequences near the NH2-terminus of band 3 (DDYED and EEYED) that are not conserved in mice (EEVLE and EELEN), the question naturally arose whether the existence of glycolytic enzyme complexes on erythrocyte membranes might be only a product of recent evolution. To test this hypothesis, fresh murine erythrocytes were fixed and stained with antibodies to glyceraldehyde-3-phosphate dehydrogenase (GAPDH), aldolase, phosphofructokinase (PFK), pyruvate kinase (PK), lactate dehydrogenase (LDH) and carbonic anhydrase II (CA II was used as a control, since it binds to a distant site near the COOH-terminus of band 3). Importantly, analysis of intact murine erythrocytes by confocal microscopy demonstrated that all of the above enzymes are localized to the membrane in oxygenated cells. In contrast, upon deoxygenation of the intact cells, release of the glycolytic enzymes (but not CA II) from the erythrocyte membrane and their uniform redistribution throughout the cytoplasm is observed. Because deoxyhemoglobin has been shown in human erythrocytes to compete with glycolytic enzymes (but not with CA II) for a common binding site at the NH2-terminus of band 3, these data argue that murine band 3, despite its weak homology to human band 3, still constitutes an organization center for glycolytic enzymes on the erythrocyte membrane. To further test this hypothesis, erythrocytes from band 3 knockout mice were similarly examined by confocal microscopy. Not surprisingly, all of the enzymes in all of the cells were evenly distributed throughout the cytoplasm, regardless of the oxygenation state of the cell. Further, immunoblot analyses demonstrated that glycolytic enzyme content of the band 3 knockout erythrocytes was measurably reduced compared to healthy mice, suggesting that the anion transporter may also contribute to enzyme stabilization during the lifetime of the erythrocyte. Finally, to determine whether the integrity of other membrane structures might impact the assembly of glycolytic enzyme complexes on the erythrocyte membrane, α-spectrin deficient mice were also examined for their enzyme distributions. Curiously, > 50% of the cells in any field exhibited glycolytic enzyme staining throughout the cytoplasm, with the remainder showing mainly membrane staining. Conceivably, the stabiity of glycolytic enzyme complexes on the membrane may also depend on the integrity of the membrane skeleton. Taken together, these data argue that glycolytic enzymes assemble in an oxygenation-dependent manner into complexes on murine erythrocyte membranes and that the stability of these complexes depends on the presence of band 3 and to a lesser extent α-spectrin. Supported by NIH grant GM24417.
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Hughes, T. R., S. J. Piddlesden, J. D. Williams, R. A. Harrison, and B. P. Morgan. "Isolation and characterization of a membrane protein from rat erythrocytes which inhibits lysis by the membrane attack complex of rat complement." Biochemical Journal 284, no. 1 (May 15, 1992): 169–76. http://dx.doi.org/10.1042/bj2840169.
Full textAbstract:
The membrane attack complex (MAC) of complement in humans is regulated by several membrane-bound proteins; however, no such proteins have so far been described in other species. Here we report the isolation and characterization of a rat erythrocyte membrane glycoprotein of molecular mass 21 kDa which inserts into cell membranes and is a potent inhibitor of the rat MAC. This protein, here called rat inhibitory protein (RIP), was first partially purified by column chromatography from a butanol extract of rat erythrocyte membranes. Monoclonal antibodies (Mabs) were raised against RIP and used for its affinity purification. Affinity-purified RIP was shown to inhibit in a dose-dependent manner the cobra venom factor (CVF)-mediated ‘reactive’ lysis of guinea pig erythrocytes by rat complement. Conversely, the anti-RIP MAbs 6D1 and TH9 were shown to markedly enhance the CVF-mediated lysis of rat erythrocytes by rat complement. RIP acted late in the assembly of the MAC (at or after the C5b-8 stage) and was releasable from the membranes of rat erythrocytes by phosphatidylinositol-specific phospholipase C. These features, together with its size, deglycosylation pattern and N-terminal amino acid sequence, lead us to conclude that RIP is the rat homologue of the human MAC-inhibitory protein CD59 antigen.
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Rabadanova, A. I. "Structural and Functional State of Erythrocyte Membranes at Drug Addiction." Journal of Ural Medical Academic Science 18, no. 1 (2021): 13–19. http://dx.doi.org/10.22138/2500-0918-2021-18-1-13-19.
Full textAbstract:
The steady growth in the number of drug addicts, especially among young people, dictates the need to find ways to prevent and treat this disease. In this regard, there is a need for a more detailed study of the mechanisms of the course of this disease using modern research methods, such as atomic force microscopy and fluorescence analysis of amino acid residues. Purpose of the work: to reveal the structural and functional state of erythrocyte membranes in drug addiction. Materials and methods. The studies were carried out on the erythrocyte membranes of 60 subjects suffering from heroin addiction. The shape and topography of the erythrocyte surface were studied, and spectral analysis of the proteins of the erythrocyte membranes was carried out. Results. The conducted AFM studies of erythrocyte membranes indicate the heterogeneity of the surface mechanical properties of the erythrocyte membranes of drug addicts. The data obtained indicate an acceleration of the aging process of erythrocytes in drug addiction, which goes in two ways: the formation of outgrowths on the plasmolemma, which subsequently die off (echinocytes) and invagination of the plasmolemma of erythrocytes (spherocytes). The fluorescence spectrum of amino acids in erythrocytes of drug addicts is characterized by a significant decrease in the intensity of almost all peaks and a shift of the fluorescence peak to the short-wave region. Findings. With drug addiction, changes in the structural integrity of red blood cells are noted. In people with drug addiction, in comparison with healthy people, there is a higher variability of the morphology of erythrocytes, which is expressed in a significant increase in the proportion of echinocytes and spherocytes against the background of a significant decrease in the number of discocytes. For the membrane proteins of erythrocytes of drug addicts, conformational changes are characteristic, manifested in a decrease in the intensity of fluorescence of aromatic amino acids, which indicates their structural modification and significant vulnerability of the hematopoietic system. They are largely determined by changes in the fluorescence intensity of tryptophan and, to a lesser extent, tyrosine, which indicates the preservation of the three-dimensional structure of the protein.
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Suwalsky, M., P. Hernández, F. Villena, F. Aguilar, and C. P. Sotomayor. "Interaction of the Anticancer Drug Tamoxifen with the Human Erythrocyte Membrane and Molecular Models." Zeitschrift für Naturforschung C 53, no. 3-4 (April 1, 1998): 182–90. http://dx.doi.org/10.1515/znc-1998-3-407.
Full textAbstract:
Abstract Tamoxifen, Anticancer Drug, Erythrocyte Membrane, Phospholipid Bilayer Tamoxifen is a non steroidal antiestrogen drug extensively used in the prevention and treatment of hormone-dependent breast cancer. To evaluate its perturbing effect upon cell membranes it was made to interact with human erythrocytes and molecular models. These consisted of bilayers of dimyristoylphosphatidylcholine (DMPC) and of dimyristoylphospha-tidylethanolamine (DMPE), representative of phospholipids classes located in the outer and inner leaflets of the erythrocyte membrane, respectively. Experiments by fluorescence spectroscopy showed that tamoxifen interacted with DMPC vesicles fluidizing both its polar head and acyl chain regions. These results were confirmed by X-ray diffraction which indi cated that tamoxifen perturbed the same regions of the lipid. However, it did not cause any significant structural perturbation to DMPE bilayers. The examination by electron micro scopy of human erythrocytes incubated with tamoxifen revealed that they changed their normal discoid shape to stomatocytes. According to the bilayer couple hypothesis, this result means that the drug is inserted in the inner leaflet of the erythrocyte membrane. Given the fact that tamoxifen did not interact with DMPE, it is concluded that it interacted with a protein located in the cytoplasmic moiety of the erythrocyte membrane.
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AMOAKO, K., Y. GOTO, N. MISAWA, D. XU, and T. SHINJO. "Interactions between hemolysin, erythrocytes and erythrocyte membranes." FEMS Microbiology Letters 150, no. 1 (May 1, 1997): 101–6. http://dx.doi.org/10.1016/s0378-1097(97)00104-3.
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Muslim, Zulfahmi, Aris Prasetyo, and Septa Surya Wahyudi. "Pengaruh Vitamin C terhadap Fragilitas Osmotik Eritrosit pada Mahasiswa Kedokteran Universitas Jember yang Mengalami Stres Psikologis." Pustaka Kesehatan 7, no. 1 (April 26, 2020): 14. http://dx.doi.org/10.19184/pk.v7i1.17585.
Full textAbstract:
Medical students are constantly getting stress that could lead to oxidative stress where the level of free radicals is higher than the level of antioxidants in the body. Free radicals can bind to erythrocyte membranes and alter membrane structure that lead to the integrity of the erythrocyte membrane resulting in decreased erythrocyte ability in preventing hemolysis. Vitamin C is an antioxidant that could prevent free radicals bond to erythrocyte membrane. Vitamin C works by donating electrons to free radicals and prevent binding to erythrocyte membranes. The purposed of this study was to determine the effect of vitamin C consumption on osmotic fragility of erythrocytes in medical students with psychological stress. This research was clinical trial research with quasi experimental with pretest-posttest control group design. Researchers used Depression Anxiety Stress Scale (DASS) questionnaire to measure the stress level. Data analysis using T test obtained mean of percentage of hemolysis between pretest and posttest was p= 0,02. It can be concluded that there is significant difference on osmotic fragility due to Vitamin C consumption in medical Student of Jember University with psychological stress.
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Sahakyan, G. V., G. G. Artsruni, and G. A. Poghosyan. "The in vitro influence of external electrostatic field on the lipid-protein interactions in membranes of rat erythrocytes." COMPEL: The International Journal for Computation and Mathematics in Electrical and Electronic Engineering 34, no. 4 (July 6, 2015): 1070–75. http://dx.doi.org/10.1108/compel-10-2014-0242.
Full textAbstract:
Purpose – The purpose of this paper is to investigate the in vitro influence of 200 kV/m electrostatic fields (ESF) on the microviscosity, viscosity and polarity of rat erythrocyte membranes for revealing the possible changes in lipid-protein interactions due to the field influence. Design/methodology/approach – The investigation of the parameters of erythrocyte membranes and their ghosts, particularly, their microviscosity, the amount and immersion degree of membrane proteins in lipid bilayer, polarity in depth of membrane and its viscosity carried out by the spectrofluorimetric method using the hydrophobic fluorescent probe pyrene. Findings – The carried out investigations shown that the in vitro influence of ESF changes membrane microviscosity, the quantity of membrane peripheral proteins and their immersion degree in the lipid bilayer, if the ghosts have prepared from erythrocytes previously exposed in the field. The analysis of the same parameters for previously prepared erythrocyte ghosts exposed to the 200 kV/m ESF during an hour did not reveal any changes. Originality/value – Data obtained and their comparison with the results of the previous works allow authors to conclude that the in vitro influence of ESF leads to the changes in the lipid-protein interactions in erythrocyte membranes.
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Fujimagari, M., PL Williamson, and RA Schlegel. "Ca2(+)-dependent membrane-binding proteins in normal erythrocytes and erythrocytes from patients with chronic myelogenous leukemia." Blood 75, no. 6 (March 15, 1990): 1337–45. http://dx.doi.org/10.1182/blood.v75.6.1337.1337.
Full textAbstract:
Abstract Cytosolic and membrane fractions of human erythrocytes were probed with antisera raised against several members of the annexin family of Ca2(+)- dependent phospholipid/membrane-binding proteins. One of the antisera, that against the 67 Kd calcimedin, identified erythrocyte polypeptides of molecular weights 48 and 67 Kd, which were found in the cytoplasm when normal erythrocytes were lysed in the presence of EGTA but on the membrane when lysis buffers contained Ca2+. In contrast, membranes of erythrocytes from patients with chronic myelogenous leukemia (CML) contained the 67 Kd protein even when prepared in the absence of Ca2+, as well as the antibody-reactive proteins of 35 and 38 Kd. When prepared in the presence of Ca2+, CML membranes contained increased levels of these three species and the 48 Kd protein, as well. These results suggest that normal erythrocytes contain a calcimedin-like protein that is translocated to the membrane in the presence of Ca2+ and that CML erythrocytes have both an abnormal amount and distribution of calcimedin-like proteins.
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Fujimagari, M., PL Williamson, and RA Schlegel. "Ca2(+)-dependent membrane-binding proteins in normal erythrocytes and erythrocytes from patients with chronic myelogenous leukemia." Blood 75, no. 6 (March 15, 1990): 1337–45. http://dx.doi.org/10.1182/blood.v75.6.1337.bloodjournal7561337.
Full textAbstract:
Cytosolic and membrane fractions of human erythrocytes were probed with antisera raised against several members of the annexin family of Ca2(+)- dependent phospholipid/membrane-binding proteins. One of the antisera, that against the 67 Kd calcimedin, identified erythrocyte polypeptides of molecular weights 48 and 67 Kd, which were found in the cytoplasm when normal erythrocytes were lysed in the presence of EGTA but on the membrane when lysis buffers contained Ca2+. In contrast, membranes of erythrocytes from patients with chronic myelogenous leukemia (CML) contained the 67 Kd protein even when prepared in the absence of Ca2+, as well as the antibody-reactive proteins of 35 and 38 Kd. When prepared in the presence of Ca2+, CML membranes contained increased levels of these three species and the 48 Kd protein, as well. These results suggest that normal erythrocytes contain a calcimedin-like protein that is translocated to the membrane in the presence of Ca2+ and that CML erythrocytes have both an abnormal amount and distribution of calcimedin-like proteins.
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Olorunsogo, O. O., F. O. Agbolade, S. O. Owojuyigbe, J. A. Adebisi, A. O. Adebayo, and W. G. Okunade. "Comparative action of calpain on erythrocyte Ca2+-pumping ATPase in sickle cell anaemia, essential hypertension and kwashiorkor." Bioscience Reports 10, no. 3 (June 1, 1990): 281–91. http://dx.doi.org/10.1007/bf01117244.
Full textAbstract:
Calpain, a calcium-dependent, neutral cysteine-protease was purified from the erythrocyte cytosol of subjects having essential hypertension (HTN), sickle cell anaemia, (SCA), or kwashiorkor (KWA). Identical electrophoretic mobility on SDS-polyacrylamide gradient gel, sensitivity to micromolar amounts of Ca2+, absolute requirement for a reducing environment and a high susceptibility to inhibition by leupeptin and thiol-group modifying reagents confirm that calpain preparations from these erythrocytes are equivalent to calpain I. Whereas the extent of calpain activation of erythrocyte membrane Ca2+-pumping ATPase of normal subjects was almost equal to that due to calmodulin, calpain activation of the HTN and SCA pump was greater than activation by calmodulin. Like in normal membranes, exogenous calmodulin protected the Ca2+-pumping ATPase of these erythrocytes against calpainization; the degree of protection by calmodulin is least in SCA and HTN. Electrophoretic separation of erythrocyte membranes and the purified Ca2+-pumping ATPase of HTN, SCA and KWA subjects does not indicate the presence of fragments resulting from the proteolytic action of calpain.
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Linko, Anna-Maria, and Herman Adlercreutz. "Whole-grain rye and wheat alkylresorcinols are incorporated into human erythrocyte membranes." British Journal of Nutrition 93, no. 1 (January 2005): 11–13. http://dx.doi.org/10.1079/bjn20041281.
Full textAbstract:
Alkylresorcinols (AR), a group of phenolic lipids, exist in the human diet in whole-grain rye and wheat. They are absorbed by humans and have been quantified in plasma. In this 2-week study we assessed AR incorporation into human erythrocyte membranes. Nine subjects attended the study; four avoided whole-grain products for 1 week and then included whole-grain rye and wheat bread in the diet for the second week, four included whole-grain rye and wheat products in the diet during the whole follow-up and one followed a gluten-free diet. Plasma and erythrocyte membrane AR were analysed after weeks 1 and 2. Erythrocyte membrane AR concentrations increased an average of 231 nmol/l of packed erythrocytes (P=0·036) after consumption of whole-grain rye and wheat products. Plasma AR levels increased an average of 175 nmol/l (P=0·058) When intake of whole-grain products was constant, erythrocyte membrane and plasma AR levels remained stable. Long-chain AR were incorporated into erythrocyte membranes in a higher proportion compared to shorter-chain AR. This preliminary study shows that AR are incorporated into human erythrocyte membranesin vivo.
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Kushnerova, Natalia F., Yu A. Rakhmanin, T. V. Momot, S. E. Fomenko, V. G. Sprygin, L. N. Lesnikova, E. S. Drugova, V. Yu Merzliakov, and L. N. Fedyanina. "IMPACT OF HYPERBARIC STRESS ON LIPID COMPOSITION OF BLOOD PLASMA AND PHYSIOLOGICAL-BIOCHEMICAL CHARACTERISTICS OF ERYTHROCYTES IN DIVERS: PREVENTION OF VIOLATIONS BY VEGETABLE POLYPHENOLS." Hygiene and sanitation 98, no. 3 (April 29, 2019): 250–55. http://dx.doi.org/10.18821/0016-9900-2019-98-3-250-255.
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There was studied lipid composition of blood plasma and erythrocyte membranes, physiological characteristics of erythrocytes in divers, exposed to extreme factors of the hyperbaric environment in the process of the occupational activity. There was observed a group of 10 male divers from 25 to 30 years of age, whose work is associated with the systematic implementation of submarine dives at medium and large depths (20-60 m) using compressed air for breathing. The influence of hyperbaric stress was shown to be accompanied by the change in a ratio of fatty acids in the total lipids of blood plasma and erythrocyte membranes. In total lipids of blood plasma and erythrocyte membranes the number of all kinds of saturated fatty acids (myristic acid, palmitic acid, stearic acid), the monounsaturated fatty acids (palmitoleic acid) was increased and an amount of polyunsaturated fatty acids of n-6 family (arachidonic acid) and n-3 (eicosapentaenoic acid) was reduced, which caused a change in physicochemical properties of erythrocytes, permeability, and lability. The increase in the amount of cholesterol in the erythrocyte membranes correlates with its elevation in blood plasma. There was an increase in the volume of erythrocytes by 5% and diameter by 13%, due to the inclusion of cholesterol in the membrane. It was recorded a shift in the threshold of hemolysis start at 0.50 ± 0.02% NaCl and its completion at 0.40 ± 0.01% NaCI. Preventive administration of the Kalifen food supplement for two months before the dive would help to remove metabolic disorders caused by the hyperbaric factors.
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Watts, M. J., J. R. Dankert, and B. P. Morgan. "Isolation and characterization of a membrane-attack-complex-inhibiting protein present in human serum and other biological fluids." Biochemical Journal 265, no. 2 (January 15, 1990): 471–77. http://dx.doi.org/10.1042/bj2650471.
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We have previously reported the isolation of a membrane-attack-complex-inhibiting protein (MIP) from human erythrocyte membranes [Watts, Patel & Morgan (1987) Complement 4, 236] and the production of polyclonal antibodies to this protein. Here we report the identification in plasma, urine, saliva and cerebrospinal fluid of a protein immunochemically identical with the membrane-derived MIP. The protein has been isolated from plasma by immunoaffinity chromatography on an anti-(erythrocyte MIP)-Sepharose column and shown by SDS/polyacrylamide-gel electrophoresis to be of similar molecular mass to the erythrocyte protein (55 kDa non-reduced and 65 kDa under reducing conditions). Monoclonal antibodies have been raised against plasma MIP and used to establish a two-site enzyme-linked immunoadsorbent assay, enabling quantification of MIP in plasma, urine and cerebrospinal fluid. Plasma MIP, though not able to incorporate spontaneously into membranes, was deposited on heterologous and homologous erythrocyte membranes during complement activation in a C8-dependent manner. Depletion of MIP from plasma resulted in enhancement of the lytic capacity of the plasma on heterologous erythrocytes.
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Kirch, H. J., G. Spates, R. Droleskey, W. J. Kloft, and J. R. DeLoach. "Hemolysis of erythrocytes by the hemolytic system from the blood-feeding stable fly, Stomoxys calcitrans." Proceedings, annual meeting, Electron Microscopy Society of America 50, no. 1 (August 1992): 690–91. http://dx.doi.org/10.1017/s0424820100123854.
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Blood feeding insects have to rely on the protein content of mammalian blood to insure reproduction. A substantial quantity of protein is provided by hemoglobin present in erythrocytes. Access to hemoglobin is accomplished only via erythrocyte lysis. It has been shown that midgut homogenates from the blood feeding stable fly, Stomoxys calcitrans, contain free fatty acids and it was proposed that these detergent-like compounds play a major role as hemolysins in the digestive physiology of this species. More recently sphingomyelinase activity was detected in midgut preparations of this fly, which would provide a potential tool for the enzymatic cleavage of the erythrocyte's membrane sphingomyelin. The action of specific hemolytic factors should affect the erythrocyte's morphology. The shape of bovine erythrocytes undergoing in vitro hemolysis by crude midgut homogenates from the stable fly was examined by scanning and transmission electron microscopy.
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Ficarra, Silvana, Annamaria Russo, Davide Barreca, Elena Giunta, Antonio Galtieri, and Ester Tellone. "Short-Term Effects of Chlorpromazine on Oxidative Stress in Erythrocyte Functionality: Activation of Metabolism and Membrane Perturbation." Oxidative Medicine and Cellular Longevity 2016 (2016): 1–10. http://dx.doi.org/10.1155/2016/2394130.
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The purpose of this paper is to focus on the short-term effects of chlorpromazine on erythrocytes because it is reported that the drug, unstable in plasma but more stable in erythrocytes, interacts with erythrocyte membranes, membrane lipids, and hemoglobin. There is a rich literature about the side and therapeutic effects or complications due to chlorpromazine, but most of these studies explore the influence of long-term treatment. We think that evaluating the short-term effects of the drug may help to clarify the sequence of chlorpromazine molecular targets from which some long-term effects derive. Our results indicate that although the drug is primarily intercalated in the innermost side of the membrane, it does not influence band 3 anionic flux, lipid peroxidation, and protein carbonylation processes. On the other hand, it destabilizes and increases the autooxidation of haemoglobin, induces activation of caspase 3, and, markedly, influences the ATP and reduced glutathione levels, with subsequent exposure of phosphatidylserine at the erythrocyte surface. Overall our observations on the early stage of chlorpromazine influence on erythrocytes may contribute to better understanding of new and interesting characteristics of this compound improving knowledge of erythrocyte metabolism.
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Ajdžanović, Vladimir, Ivan Spasojević, Branko Filipović, Branka Šošić-Jurjević, Milka Sekulić, and Verica Milošević. "Effects of genistein and daidzein on erythrocyte membrane fluidity: an electron paramagnetic resonance study." Canadian Journal of Physiology and Pharmacology 88, no. 4 (April 2010): 497–500. http://dx.doi.org/10.1139/y10-020.
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The maintenance of erythrocyte membrane fluidity at the physiological level is an important factor affecting the ability of erythrocytes to pass through blood vessels of small luminal diameter. Genistein and daidzein, which are used as alternative therapeutics in cardiovascular conditions, can be incorporated into the cell membrane and change its fluidity. The aim of this study was to examine the effects of genistein and daidzein on erythrocyte membrane fluidity at graded depths. We used electron paramagnetic resonance (EPR) spectroscopy and fatty acid spin probes (5-DS and 12-DS) where EPR spectra were dependent on fluidity. The results showed that genistein significantly (p < 0.05) decreased erythrocyte membrane fluidity near the hydrophilic surface, while daidzein significantly (p < 0.05) increased the same parameter in deeper regions of the membrane. These data suggest that the deep fluidizing effects of daidzein on erythrocyte membranes make it a better therapeutic choice than genistein in some cardiovascular conditions.
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Ortiz, G. G., F. Pacheco-Moisés, M. El Hafidi, A. Jiménez-Delgado, M. A. Macías-Islas, S. A. Rosales Corral, A. Célis de la Rosa, V. J. Sánchez-González, E. D. Arias-Merino, and I. E. Velázquez-Brizuela. "Detection of Membrane Fluidity in Submitochondrial Particles of Platelets and Erythrocyte Membranes from Mexican Patients with Alzheimer Disease by Intramolecular Excimer Formation of 1,3 Dipyrenylpropane." Disease Markers 24, no. 3 (2008): 151–56. http://dx.doi.org/10.1155/2008/642120.
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It has been suggested that mitochondrial dysfunction and defects in membrane structure could be implied in AD pathogenesis. The aim of the present work was the study of membrane fluidity in submitochondrial platelet particles and erythrocyte membranes from Mexican patients. Blood samples were obtained from 30 patients with Alzheimer disease and 30 aged-matched control subjects. Membrane fluidity determinations were done using a very low concentration of the fluorescent dipyrenylpropane probe incorporated in both types of membranes. This probe is able to give excimer and monomer fluorescence, therefore it can be used to monitor fluidity changes in biological membranes.The data obtained showed that in submitochondrial particles from AD patients, the excimer to monomer fluorescent intensity ratio was lower (0.231 ± 0.008) than aged-matched control subjects (0.363 ± 0.014). Therefore, membrane fluidity was lower in AD samples. On the other hand, we found similar membrane fluidity in erythrocytes from AD patients and aged-matched controls: the fluorescent intensity ratios were 0.312 ± 0.03 and 0.305 ± 0.033, respectively. In addition, lipid peroxidation in submitochondrial particles and erythrocyte membranes was higher in AD samples than in aged-matched controls. These data suggest that submitochondrial platelet particles are more sensitive to oxidative stress than erythrocyte membranes.
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Caulfield, J. P., and C. M. Cianci. "Human erythrocytes adhering to schistosomula of Schistosoma mansoni lyse and fail to transfer membrane components to the parasite." Journal of Cell Biology 101, no. 1 (July 1, 1985): 158–66. http://dx.doi.org/10.1083/jcb.101.1.158.
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We studied the adherence of human erythrocytes to larvae of the intravascular parasite Schistosoma mansoni by transmission microscopy, freeze fracture, and fluorescence techniques. In addition, we used the adherent cells to investigate the problem of host antigen acquisition. Schistosomula were cultured for from 24 to 48 h after transformation in order to clear the remnants of the cercarial glycocalyx. In some cases, the worms were preincubated with wheat germ agglutinin to promote adherence of the erythrocytes. The results were similar with and without the lectin except that more cells attached to the lectin-coated parasites. Erythrocytes adhered within a few hours and, unlike neutrophils, did not fuse with the parasite. A layer of 10-20-nm electron dense material separated the outer leaflets of the tegumental and plasma membranes. In addition, many deformed and lysed cells were seen on the parasite surface. The ability of the worm to acquire erythrocyte membrane constituents was tested with carbocyanine dyes, fluorescein covalently conjugated to glycophorin, monoclonal antibodies against B and H blood group glycolipids, and rabbit alpha-human erythrocyte IgG. In summary, glycophorin, erythrocyte proteins, and glycolipids were not transferred to the parasite membrane within 48 h. Carbocyanine dyes were rapidly transferred to the parasite with or without lectin preincubation. Thus, the dye in the worm membrane came from both adherent and nonadherent cells. These studies suggest that, in the absence of membrane fusion, the parasite may acquire some lipid molecules similar in structure to host membrane glycolipids by simple transfer through the medium but that B and H glycolipids and erythrocyte membrane proteins are not transferred from adhering cells to the worm.
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Magowan, C., RL Coppel, AO Lau, MM Moronne, G. Tchernia, and N. Mohandas. "Role of the Plasmodium falciparum mature-parasite-infected erythrocyte surface antigen (MESA/PfEMP-2) in malarial infection of erythrocytes." Blood 86, no. 8 (October 15, 1995): 3196–204. http://dx.doi.org/10.1182/blood.v86.8.3196.3196.
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Abstract During intraerythrocytic growth of Plasmodium falciparum, several parasite proteins are transported from the parasite to the erythrocyte membrane, where they bind to membrane skeletal proteins. Mature-parasite-infected erythrocyte surface antigen (MESA) has previously been shown to associate with host erythrocyte membrane skeletal protein 4.1. Using a spontaneous mutant of P falciparum that has lost the ability to synthesize MESA and 4.1-deficient erythrocytes, we examined growth of MESA(+) and MESA(-) parasites in normal and 4.1-deficient erythrocytes. Viability of MESA(+) parasites was reduced in 4.1-deficient erythrocytes as compared with that for normal erythrocytes, but MESA(-) parasites grew equally well in 4.1-deficient and normal erythrocytes. Cytoadherence of MESA(+)- and MESA (-)-parasitized normal and 4.1-deficient erythrocytes to C32 melanoma cells was similar, indicating that neither protein 4.1 nor MESA plays a major role in cytoadherence of infected erythrocytes. Localization of MESA in normal and 4.1-deficient erythrocytes was examined by confocal microscopy. MESA was diffusely distributed in the cytosol of 4.1-deficient erythrocytes but was membrane-associated in normal erythrocytes. These findings suggest that MESA binding to protein 4.1 plays a major role in intraerythrocytic parasite viability.
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Magowan, C., RL Coppel, AO Lau, MM Moronne, G. Tchernia, and N. Mohandas. "Role of the Plasmodium falciparum mature-parasite-infected erythrocyte surface antigen (MESA/PfEMP-2) in malarial infection of erythrocytes." Blood 86, no. 8 (October 15, 1995): 3196–204. http://dx.doi.org/10.1182/blood.v86.8.3196.bloodjournal8683196.
Full textAbstract:
During intraerythrocytic growth of Plasmodium falciparum, several parasite proteins are transported from the parasite to the erythrocyte membrane, where they bind to membrane skeletal proteins. Mature-parasite-infected erythrocyte surface antigen (MESA) has previously been shown to associate with host erythrocyte membrane skeletal protein 4.1. Using a spontaneous mutant of P falciparum that has lost the ability to synthesize MESA and 4.1-deficient erythrocytes, we examined growth of MESA(+) and MESA(-) parasites in normal and 4.1-deficient erythrocytes. Viability of MESA(+) parasites was reduced in 4.1-deficient erythrocytes as compared with that for normal erythrocytes, but MESA(-) parasites grew equally well in 4.1-deficient and normal erythrocytes. Cytoadherence of MESA(+)- and MESA (-)-parasitized normal and 4.1-deficient erythrocytes to C32 melanoma cells was similar, indicating that neither protein 4.1 nor MESA plays a major role in cytoadherence of infected erythrocytes. Localization of MESA in normal and 4.1-deficient erythrocytes was examined by confocal microscopy. MESA was diffusely distributed in the cytosol of 4.1-deficient erythrocytes but was membrane-associated in normal erythrocytes. These findings suggest that MESA binding to protein 4.1 plays a major role in intraerythrocytic parasite viability.