Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P08758 (annexin V)
 9,383 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Eryptosis, the suicidal death of erythrocytes, is characterized by cell shrinkage and by cell membrane scrambling with phosphatidylserine exposure at the erythrocyte surface. Eryptosis is triggered by several stress conditions including isotonic cell shrinkage (Cl(-) removal) and energy depletion (glucose removal). Both are effective through an increase in the cytosolic Ca(2+) concentration. Phosphatidylserine-exposing erythrocytes are cleared from circulating blood. Enhanced eryptosis thus leads to anemia. Accordingly, drugs interfering with eryptosis may prove useful in the treatment of anemia. The present study explored, whether caffeine interferes with eryptosis. Erythrocyte phosphatidylserine exposure was estimated from annexin V-binding, cell volume from forward scatter and cytosolic Ca(2+) activity from Fluo3 fluorescence. Under control conditions, eryptosis affected less than 5% of the erythrocytes and was not significantly modified by the presence of caffeine (50-500 microM). Glucose depletion (for 48 hours) significantly increased Fluo3 fluorescence and annexin V-binding and decreased forward scatter, effects partially reversed by caffeine (500 microM). Low Cl(-) solution (Cl(-) exchanged by gluconate for 48 hours) similarly increased annexin V-binding and decreased forward scatter, effects again reversed by caffeine (50-500 microM). In conclusion, caffeine inhibits Ca(2+) entry following glucose depletion and thus counteracts eryptosis during isotonic cell shrinkage and energy depletion.
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PMID:Caffeine inhibits suicidal erythrocyte death. 1876 52

Chlorpromazine has previously been shown to trigger suicidal erythrocyte death or eryptosis, which is characterized by exposure of phosphatidylserine at the erythrocyte surface and cell shrinkage. Premature suicidal death of infected erythrocytes is in turn considered to delay development of parasitemia and thus favourably influence the clinical course of malaria. The present experiments have been performed to explore whether chlorpromazine influences in vitro parasite growth and eryptosis of Plasmodium falciparum infected human erythrocytes and in vivo parasitemia and survival of P. berghei infected mice. Phosphatidylserine was estimated from annexin V binding and cell volume from forward scatter in FACS analysis. In vitro infection of human erythrocytes increased annexin binding and decreased forward scatter, effects augmented in the presence of chlorpromazine (>or=10 microM). Chlorpromazine did not significantly alter intraerythrocytic DNA/RNA content but significantly (>or=1 microM) decreased in vitro parasitemia. In chlorpromazine treated mice erythrocytes were more rapidly cleared from circulating blood than in nontreated mice. Parasitemia in P. berghei infected mice was significantly decreased (from 50 % to 28 % of circulating erythrocytes 22 days after infection) and mouse survival significantly enhanced (from 0 % to 80 % 30 days after infection) by addition of 1 mM chlorpromazine to the drinking water from the first day of infection. In conclusion, chlorpromazine favourably influences the course of malaria, an effect at least partially due to stimulation of suicidal erythrocyte death.
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PMID:Influence of chlorpromazine on eryptosis, parasitemia and survival of Plasmodium berghe infected mice. 1876 53

Phosphatidylserine (PS) exposure occurs during the cell death program and fluorescein-labeled lactadherin permits the detection of PS exposure earlier than annexin V in suspended cell lines. Adherent cell lines were studied for this apoptosis-associated phenomenon to determine if PS probing methods are reliable because specific membrane damage may occur during harvesting. Apoptosis was induced in the human tongue squamous carcinoma cell line (Tca8113) and the adenoid cystic carcinoma cell line (ACC-2) by arsenic trioxide. Cells were harvested with a modified procedure and labeled with lactadherin and/or annexin V. PS exposure was localized by confocal microscopy and apoptosis was quantified by flow cytometry. The detachment procedure without trypsinization did not induce cell damage. In competition binding experiments, phospholipid vesicles competed for more than 95 and 90% of lactadherin but only about 75 and 70% of annexin V binding to Tca8113 and ACC-2 cells. These data indicate that PS exposure occurs in three stages during the cell death program and that fluorescein-labeled lactadherin permitted the detection of early PS exposure. A similar pattern of PS exposure has been observed in two malignant cell lines with different adherence, suggesting that this pattern of PS exposure is common in adherent cells. Both lactadherin and annexin V could be used in adherent Tca8113 and ACC-2 cell lines when an appropriate harvesting procedure was used. Lactadherin is more sensitive than annexin V for the detection of PS exposure as the physical structure of PS in these blebs and condensed apoptotic cell surface may be more conducive to binding lactadherin than annexin V.
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PMID:Measurement of annexin V uptake and lactadherin labeling for the quantification of apoptosis in adherent Tca8113 and ACC-2 cells. 1882 Jul 63

Bismuth is used for multiple industrial purposes and in the treatment of several gastrointestinal diseases. Untoward effects of bismuth include anemia, which could, in theory, result from suicidal erythrocyte death or eryptosis. Hallmarks of eryptosis are cell shrinkage and cell membrane scrambling with phosphatidylserine exposure at the cell surface. Phosphatidylserine-exposing cells are rapidly cleared from circulating blood. Signaling leading to eryptosis includes increase in cytosolic Ca(2+) activity and formation of ceramide. The present experiments explored whether bismuth elicits eryptosis. To this end, phosphatidylserine exposure was estimated from annexin V-binding, cell shrinkage from decrease of forward scatter in FACS analysis, cytosolic Ca(2+) activity from Fluo3 fluorescence and ceramide abundance from binding of fluorescent antibodies. A 48 h exposure to bismuth (> or =500 microg/l BiCl(3)) enhanced the percentage of annexin V-binding cells and decreased forward scatter, increased cytosolic Ca(2+) activity, and stimulated ceramide formation. In conclusion, bismuth stimulates eryptosis, the suicidal death of erythrocytes. The effect may contribute to or even account for the development of anemia during bismuth treatment. Moreover, ceramide formation in intestinal cells may participate in the therapeutic efficacy of bismuth preparations.
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PMID:Eryptosis triggered by bismuth. 1904 90

Plasmodia express a sphingomyelinase, which is apparently required for their development. On the other hand, the sphingomyelinase product ceramide has previously been shown to delay parasite development. Moreover, ceramide triggers suicidal erythrocyte death or eryptosis, characterized by exposure of phosphatidylserine at the erythrocyte surface and cell shrinkage. Accelerated eryptosis of infected erythrocytes is considered to clear infected erythrocytes from circulating blood and, thus, to favourably influence the clinical course of malaria. The present experiments explored whether the sphingomyelinase inhibitor amitriptyline or genetic knockout of host acid sphingomyelinase influence in vitro parasite growth, eryptosis of Plasmodium falciparum-infected human erythrocytes, in vivo parasitemia and survival of P. berghei-infected mice. Phosphatidylserine exposure was determined by annexin V-binding and cell volume by forward scatter in FACS analysis. In vitro infection of human erythrocytes increased annexin- binding, an effect blunted in the presence of amitriptyline (>or=50 microM). Amitriptyline did not significantly alter intraerythrocytic parasite development but significantly (>or= 1 microM) delayed the increase in parasitemia in vitro. Most importantly, amitriptyline treatment (1 mM in drinking water) resulted in a significant delay of parasitemia and death of infected mice. However, upon infection, ceramide formation was stimulated in both, acid sphingomyelinase knockout mice (Smpd1(-/-)) and their wild type littermates (Smpd1(+/+)). Parasitemia following P. berghei infection was significantly lower in Smpd1(-/-) than in Smpd1(+/+) mice but did not significantly extend the life span of infected animals. In conclusion, mammalian and parasite sphingomyelinase contribute to ceramide formation during malaria, whereby the parasite sphingomyelinase ultimately determines the course of the infection. Amitriptyline presumably blocks both sphingomyelinases and, thus, its use might be a novel strategy to treat malaria.
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PMID:Influence of amitriptyline on eryptosis, parasitemia and survival of Plasmodium berghei-infected mice. 1908 22

Paclitaxel triggers suicidal erythrocyte death or eryptosis, characterized by exposure of phosphatidylserine at the erythrocyte surface and cell shrinkage. Eryptosis of infected erythrocytes may delay development of parasitemia and thus favourably influence the course of malaria. The present study explored whether paclitaxel influences in vitro parasite growth and eryptosis of Plasmodium falciparum infected human erythrocytes and in vivo parasitemia and survival of Plasmodium berghei infected mice. Phosphatidylserine exposing erythrocytes were identified utilizing annexin V binding and erythrocyte volume was estimated from forward scatter in FACS analysis. In vitro infection of human erythrocytes with P. falciparum increased annexin binding and decreased forward scatter, effects augmented in the presence of paclitaxel (> or = 0.01 microM). Paclitaxel (> or = 0.01 microM) significantly decreased intraerythrocytic DNA/RNA content and in vitro parasitemia. In Plasmodium berghei infected mice parasitemia was significantly decreased (from 55.8% to 28.6% of circulating erythrocytes 20 days after infection) and mouse survival significantly enhanced (from 0% to 69.23% 25 days after infection) by administration of 8.5 mg/kg.b.w. of paclitaxel intraperitoneally from the eighth day of infection. In conclusion, paclitaxel decreases parasitemia and enhances survival of P. berghei infected mice, an effect, which may be due to stimulation of eryptosis and/or a direct toxic effect on the parasite.
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PMID:Influence of paclitaxel on parasitemia and survival of Plasmodium berghei infected mice. 1925 13

Owing to its antibiotic activity, silver is used for water purification, wound care and a wide variety of implants. Silver metal and silver compounds ionize in solution, and silver ions interfere with the function of a wide variety of proteins. In mammalian cells, silver ions may trigger apoptosis by stimulation of cytochrome c release from mitochondria. The present study explored the effect of AgNO3 on eryptosis, the suicidal death of erythrocytes, cells devoid of mitochondria. Similar to apoptosis of nucleated cells, eryptosis is characterized by cell shrinkage and cell membrane scrambling with phosphatidylserine exposure at the cell surface. Eryptosis is triggered by energy depletion, cellular depletion of nitric oxide (NO) and activation of protein kinase C (PKC). Phosphatidylserine exposure was determined by annexin V-binding, cell volume by forward scatter, cellular ATP by a luciferin-luciferase assay kit, and hemolysis by photometry. A 48 h exposure to AgNO3 (> or =100 nm) but not to NaNO3 significantly enhanced the percentage of annexin V-binding cells, slightly but significantly decreased forward scatter and significantly decreased cytosolic ATP. Furthermore, inhibition of PKC by staurosporine and donation of NO by sodium nitroprusside significantly blunted silver-induced eryptosis. In conclusion, AgNO3 triggers cell membrane scrambling, an effect attributed to ATP depletion, PKC activation and decrease of cellular NO.
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PMID:Silver ion-induced suicidal erythrocyte death. 1944 54

Phospholipids are asymmetrically distributed across the membrane of all cells, including red blood cells (RBCs). Phosphatidylserine (PS) is mainly localized in the cytoplasmic membrane leaflet, but during RBC ageing it flip-flops to the external leaflet--a process that is increased in certain pathological conditions (e.g., beta-thalassemia). PS externalization in RBCs mediates their phagocytosis by macrophages and removal from the circulation. PS is usually measured by flow cytometry and is reported as the percentage of cells with external PS. In the current study, we developed a novel two-step flow cytometry procedure to quantitatively measure not only the external PS but also the intracellular and shed PS. In this method, PS is first bound to fluorescent annexin V, and then the residual nonbound annexin is quantified by binding to PS exposed on apoptotic cells. Using this method, we measured 1.1+/-0.2 and 0.12+/-0.04 micromol inner and external PS, respectively, per 10(7) normal RBCs. Thalassemic RBCs demonstrated increased PS externalization (1.7-fold) and shedding (11-fold) that was accompanied by lower intracellular PS (31%). These results suggest that quantitative flow cytometry of PS could have a diagnostic value in evaluating the pathology of RBCs in hemolytic anemias associated with increased PS externalization and shortening of the RBC life span.
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PMID:A flow cytometry approach for quantitative analysis of cellular phosphatidylserine distribution and shedding. 1953 62

Eryptosis, the suicidal death of erythrocytes, is characterized by exposure of phosphatidylserine at the erythrocyte surface and cell shrinkage. Triggers of eryptosis include anandamide. Enhanced eryptosis of infected human erythrocytes is expected to delay the development of parasitaemia during infection with Plasmodium, the parasite causing malaria. The present experiments aimed to test, whether anandamide influences eryptosis, parasite growth and/or host survival during in vitro or in vivo infection with Plasmodia. Human erythrocytes were infected in vitro with P. falciparum, and mice in vivo with P. berghei. Parasitemia was determined with Syto16. Phosphatidylserine-exposing erythrocytes were identified by analysing annexin V-binding in FACS analysis. In vitro infection of human erythrocytes was followed by a significant increase in annexin V-binding, an effect slightly enhanced by anandamide (> or = 50 microM), which significantly reduced intraerythrocytic DNA/RNA content and in vitro parasitaemia. In vivo administration of anandamide (5 mg/kg b.w. subcutaneously) blunted the parasitaemia (from 36.9% to 24.2% of circulating erythrocytes 21 days after infection) and significantly enhanced the survival of P. berghei-infected mice (from 0% to 67% 26 days after infection). The percentage of phosphatidylserine-exposing erythrocytes was significantly increased in anandamide-treated infected mice compared to non-treated infected mice. In conclusion, anandamide stimulated eryptosis of infected erythrocytes thus counteracting parasitaemia and a lethal course of the disease.
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PMID:Effect of anandamide in Plasmodium Berghei-infected mice. 2079 20

The analysis of lipid protein interaction is difficult because lipids are embedded in cell membranes and therefore, inaccessible to most purification procedures. As an alternative, lipids can be coated on flat surfaces as used for lipid ELISA and Plasmon resonance spectroscopy. However, surface coating lipids do not form microdomain structures, which may be important for the lipid binding properties. Further, these methods do not allow for the purification of larger amounts of proteins binding to their target lipids. To overcome these limitations of testing lipid protein interaction and to purify lipid binding proteins we developed a novel method termed lipid vesicle-mediated affinity chromatography using magnetic-activated cell sorting (LIMACS). In this method, lipid vesicles are prepared with the target lipid and phosphatidylserine as the anchor lipid for Annexin V MACS. Phosphatidylserine is a ubiquitous cell membrane phospholipid that shows high affinity to the protein Annexin V. Using magnetic beads conjugated to Annexin V the phosphatidylserine-containing lipid vesicles will bind to the magnetic beads. When the lipid vesicles are incubated with a cell lysate the protein binding to the target lipid will also be bound to the beads and can be co-purified using MACS. This method can also be used to test if recombinant proteins reconstitute a protein complex binding to the target lipid. We have used this method to show the interaction of atypical PKC (aPKC) with the sphingolipid ceramide and to co-purify prostate apoptosis response 4 (PAR-4), a protein binding to ceramide-associated aPKC. We have also used this method for the reconstitution of a ceramide-associated complex of recombinant aPKC with the cell polarity-related proteins Par6 and Cdc42. Since lipid vesicles can be prepared with a variety of sphingo- or phospholipids, LIMACS offers a versatile test for lipid-protein interaction in a lipid environment that resembles closely that of the cell membrane. Additional lipid protein complexes can be identified using proteomics analysis of lipid binding protein co-purified with the lipid vesicles.
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PMID:Lipid vesicle-mediated affinity chromatography using magnetic activated cell sorting (LIMACS): a novel method to analyze protein-lipid interaction. 2154 Aug 29


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