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)

Apoptosis of tumor cells and of apparently normal renal cells (ANRC) isolated from the same kidney in 42 untreated patients with renal carcinomas (RC) was evaluated. Thirty five of the investigated tumors were of Grawitz type in different grades of differentiation. The intensity of the apoptotic process was routinely assessed by propidium iodide staining and flow-cytometry analysis. Similar results were obtained in the same cases by using TUNEL assay, by staining with annexin V and by DNA electrophoresis. In 85% of Grawitz carcinomas the proportion of apoptotic tumor cells was quite high, with mean% +/- SD of 57.7+/-27.3, whereas in transitional cell carcinoma of the bladder (TCC), the mean percentage of cells in apoptosis was of 22.3+/-13.9. Unexpectedly, in ANRC displaying normal morphology and normal DNA content (diploidy), the mean% +/- SD of apoptotic cells were found to exceed that of apoptotic tumor cells, 79.2+/-21.6. The percentages of cells expressing Fas receptor and/or Fas ligand varied between large ranges in both tumor and ANRC, thus suggesting that other mechanisms are also involved in the activation of apoptosis. Immunohistochemical studies showed that the intensity of apoptosis correlated well with high p-53 and low bcl-2 expression. The intensity of apoptosis was generally not correlated with the cell proliferation index (S phase fraction), suggesting that in RC apoptosis can be activated in any stage of the cell cycle. Further investigations are necessary to understand the peculiar behaviour of tumor cells as well as of ANRC in renal carcinomas as compared to other types of malignancies.
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PMID:Evaluation of apoptosis of tumor and of apparently normal cells in human renal carcinoma. 1021 1

The present study investigated whether all-trans retinoic acid (ATRA)-induced apoptosis in acute myeloblastic leukaemia (AML) is related to changes in mitochondrial function. Two human AML cell lines, OU-AML-3 and OU-AML-7, known to be inducible to time-dependent apoptosis of varying degrees by ATRA, were used. Apoptosis induced by ATRA was shown to be a slow event. It was detected by the DNA electrophoretic method and cytofluorimetrical annexin V assay after 48 h exposure, and by morphology and polyADPribose polymerase (PARP) cleavage after 72 h exposure of AML cells to ATRA. The efflux of mitochondrial cytochrome c to cytosol was notable in Western blotting after 48 h exposure of the cells to ATRA and was observed before the drop in the mitochondrial membrane potential, which only took place after 72 h exposure, when measured by flow cytometry and a JC-1 probe. The apoptotic events in mitochondria were more evident in the OU-AML-3 than the OU-AML-7 cell line. This might relate to the different bcl-2 contents of the cell lines: the basic bcl-2 levels of the OU-AML-7 cell line were almost twofold compared to that of the OU-AML-3 cell line, as analysed by the ELISA method. However, both of the cell lines showed progressive down-regulation of bcl-2, which began after 12-24 h exposure of the cells to ATRA as determined by ELISA, Western blotting and flow cytometry. The present results show that mitochondria have a role in ATRA-induced apoptosis in AML cells and down-regulation of bcl-2 is related to it. In view of the previously published studies, the present results underline the fact that the timing of apoptotic events, such as fragmentation of DNA, externalization of phosphatidylserine, cytochrome c efflux, change in mitochondrial membrane potential and cleavage of PARP, are, to a notable extent, cell type and inducer-dependent.
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PMID:An association between mitochondrial function and all-trans retinoic acid-induced apoptosis in acute myeloblastic leukaemia cells. 1023 86

Activated mucosal macrophages are derived from circulating monocytes and appear to play a major role in the pathogenesis of IBD. We have recently shown that IBD, but not normal, mucosal macrophages express the active form of IL-1beta converting enzyme (ICE) and are therefore capable of releasing mature IL-1beta. ICE expression by other mucosal cell types is unknown. Active ICE expression has also been implicated in apoptosis. The aim of this study was to investigate ICE expression (using an antibody that recognizes both active and precursor forms) in normal and IBD mucosa and to determine whether ICE-expressing macrophages are undergoing apoptosis. Normal and active IBD mucosal cells, in tissue sections and after isolation, were studied by immunohistochemistry and flow cytometry. In the mucosa, macrophages were the predominant ICE-expressing cell type. In contrast to normal, most IBD mucosal macrophages expressed ICE. Of IBD colonic macrophages 11.8 +/- 3.2%, and of normal colonic macrophages 6.6 +/- 0.6% expressed Apo2.7, a marker for apoptotic cells. Similar data were obtained when annexin V was used to identify cells undergoing apoptosis. DNA fluorescence flow cytometric analysis of normal and IBD lamina propria cells showed the presence of only small hypodiploid DNA peaks. We conclude that in the human intestinal mucosa, macrophages are the predominant ICE-expressing cell type. Expression of the active form of ICE and macrophage apoptosis are not interdependent. One mechanism of loss of resident macrophages from normal mucosa and of recruited macrophages from IBD mucosa is by apoptosis.
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PMID:Investigation of the expression of IL-1beta converting enzyme and apoptosis in normal and inflammatory bowel disease (IBD) mucosal macrophages. 1033 15

Accumulating evidence indicates that fragmentation of ovulated murine oocytes, resulting spontaneously or following exposure to lethal stimuli such as anticancer drugs during in-vitro culture, occurs with several hallmark features of apoptosis. However, recent work has failed to demonstrate a correlation between DNA cleavage, as assessed by DNA 3'-end-labelling, or of phosphatidylserine exposure on the outer leaflet of the plasma membrane, as measured by annexin V-staining, with fragmentation of ovulated mouse or human oocytes maintained in vitro. Consequently, these authors stated that it is 'premature to conclude that apoptosis occurs in ovulated oocytes or that such a mechanism is involved in the elimination or prevention of fertilization of oocytes with cytoplasmic or chromosomal defects'. Here, we have re-assessed DNA cleavage in normal and fragmented murine oocytes, have provided new evidence of an additional biochemical marker of apoptosis in fragmented oocytes (i.e. caspase activity), and have re-evaluated published reports regarding oocyte fragmentation, in an effort to clarify these discrepant findings. The results and discussions presented herein fully support previous conclusions reached by ourselves and others that fragmentation of ovulated oocytes is in fact an unequivocal example of apoptotic cell death.
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PMID:Fragmentation and death (a.k.a. apoptosis) of ovulated oocytes. 1033 64

Scavenger receptor class B type I (SR-BI) mediates the selective uptake of high density lipoprotein cholesterol. SR-BI is expressed at high levels in the ovary, indicating that it plays a role in the delivery of cholesterol as substrate for steroid hormone production. However, SR-BI also binds anionic phospholipids with high affinity and could therefore be involved in the recognition of apoptotic cells. In this study we have characterized the expression of SR-BI in rat ovarian follicles undergoing atresia. Atretic follicles with cells undergoing apoptosis were identified by in situ DNA end labeling, and SR-BI expression was determined by in situ hybridization and immunohistochemistry. SR-BI was expressed in thecal cells at all stages of follicular development, including atretic follicles, and in corpus luteum. Isolated apoptotic granulosa cells (but not viable granulosa cells) bound annexin V, indicating that they display anionic phospholipids on the cell surface. Transfection of COS-7 cells with an expression vector carrying the rat SR-BI complementary DNA resulted in increased binding to apoptotic granulosa cells (46 +/- 2% of the SR-BI-expressing cells bound at least one granulosa cell compared with 24 +/- 3% for the mock-transfected cells; P < 0.0001), whereas the binding to viable granulosa cells was unchanged. Apoptotic granulosa cells also bound to isolated thecal shells. We conclude that thecal cells of both nonatretic and atretic follicles express SR-BI. The location of SR-BI expression in the ovary supports a role of this receptor in the uptake of high density lipoprotein cholesterol. In addition, our data suggest that SR-BI mediates the recognition of apoptotic granulosa cells by the surrounding thecal cells and that it therefore may play a role in the remodeling of atretic follicles to secondary interstitial cells.
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PMID:Scavenger receptor class B type I in the rat ovary: possible role in high density lipoprotein cholesterol uptake and in the recognition of apoptotic granulosa cells. 1034 34

Three documented cell death pathways, apoptosis, necrosis, and oncosis will be discussed. The end result of each pathway is cell death; however, the path by which death is achieved and the morphological and physiological traits of each may be strikingly distinct. Now that well characterized models have been established for particularly apoptosis, the induction pathway(s) has received much attention and the pathway pathology is beginning to be understood. Three model systems were investigated: APO-1/Fas, hypoxia, and oncosis. Cell death was induced, and during a time course sampling, a variety of methodologies, including DNA fragmentation by flow cytometry and gel electrophoresis, DNA staining, flow cytometric light scatter, transmission electron microscopy, anti-tubulin, Trypan blue, annexin V, and anti-APO2.7 were employed to monitor the cell death progress. The apoptotic pathway in the CD95-induced Jurkat cell model was further investigated using caspase inhibitor peptides and analyzed for APO2.7 antigen expression and DNA fragmentation by flow cytometry. Time course sampling characterized the cell death pathway and helped to differentiate the capabilities of the methods. The time to response and duration of the response were dependent upon cell type and method of induction. The CD95-induced Jurkat cell model showed a classical apoptotic response; however the MDA-MB-175-VII hypoxia model and the anti-5A9 induced oncosis model were not as clear. Each methodology shows advantages and disadvantages that allow the investigator to select several methods to identify, monitor, and enumerate cells with respect to cell death progression using time course studies.
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PMID:Differentiation and assessment of cell death. 1035 77

HL-60 and MCF-7 cells were treated with 0.15 microM camptothecin (CPT) or with the solvent dimethylsulfoxide (DMSO) for the controls, for 2, 3 and 4 h or for 24, 48 and 72 h, respectively. The apoptotic index (AI) was then evaluated in parallel by the following flow cytometric methods: (1) double staining of unfixed cells with fluoresceinated annexin V and propidium iodide (PI), this after detachment by trypsinization in the case of MCF-7 cultures; (2) prefixation in 70% ethanol, extraction of degraded, low molecular weight DNA with 0.2 M phosphatecitrate buffer and analysis of the DNA content stained with PI; (3) TUNEL, i.e. labelling of DNA strand breaks with biotin-dUTP, followed by staining with streptavidin-fluorescein and counterstaining with PI. In HL-60 cells, the three methods gave similar results for the AI (3-4% in the controls and at 2 h of CPT treatment, and 35-43% at 3 and 4 h after CPT). This indicates that CPT-induced membrane alteration and DNA fragmentation occurred concomitantly in those cells. For MCF-7 cells, CPT-induced apoptosis developed more slowly, the AI, whether based on annexin V or on DNA content, remained unchanged at 24 h, then was increasing to 8% at 48 h and to 25% at 72 h of treatment. In these cells, the TUNEL index did not increase prior to 72 h, and the increase was minor (up to 9% vs. 2-3% in the controls) at 72 h of the treatment. This indicates that in MCF-7 cells DNA strand breaks cannot be effectively labelled, which may be due to inaccessibility of 3'-OH ends in the breaks to exogenous terminal deoxynucleotidyl transferase. The mechanism of endonucleolytic DNA fragmentation thus may be different, depending on the cell type.
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PMID:Comparison of methods based on annexin-V binding, DNA content or TUNEL for evaluating cell death in HL-60 and adherent MCF-7 cells. 1037 1

Apoptosis and necrosis are two forms of cell death that are induced under different conditions and that differ in morphological and biochemical features. In this report, we show that, in the presence of oxidative stress, human B lymphoma cells are unable to undergo apoptosis and die instead by a form of necrosis. This was established using the chemotherapy drug VP-16 or the calcium ionophore A23187 to induce apoptosis in Burkitt's lymphoma cell lines and by measuring classical markers of apoptotic death, including cell morphology, annexin V binding, DNA ladder formation, and caspase activation. In the presence of relatively low levels of H2O2 (75-100 microM), VP-16 and A23187 were unable to induce apoptosis in these cells. Instead, the cells underwent non-apoptotic cell death with mild cytoplasmic swelling and nuclear shrinkage, similar to the death observed when they were treated with H2O2 alone. We found that H2O2 inhibits apoptosis by depleting the cells of ATP. The effects of H2O2 can be overcome by inhibitors of poly(ADP)-ribosylation, which also preserve cellular ATP levels, and can be mimicked by agents such as oligomycin, which inhibit ATP synthesis. The results show that oxidants can manipulate cell death pathways, diverting the cell away from apoptosis. The potential physiological ramifications of this finding will be discussed.
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PMID:Oxidative stress inhibits apoptosis in human lymphoma cells. 1039 22

In addition to its inhibitory activity against viral DNA polymerases and reverse transcriptase, the acyclic nucleoside phosphonate 9-(2-phosphonylmethoxyethyl)adenine (PMEA) also markedly inhibits the replicative cellular DNA polymerases alpha, delta, and epsilon. We have previously shown that PMEA is a strong inducer of differentiation in several in vitro tumor cell models and has marked antitumor potential in vivo. To elucidate the molecular mechanism of the differentiation-inducing activity of PMEA, we have now investigated the effects of the drug on cell proliferation and differentiation, cell cycle regulation, and oncogene expression in the human erythroleukemia K562 cell line. Terminal, irreversible erythroid differentiation of PMEA-treated K562 cells was evidenced by hemoglobin production, increased expression of glycophorin A on the K562 cell membrane, and induction of acetylcholinesterase activity. After exposure to PMEA, K562 cell cultures displayed a marked retardation of S-phase progression, leading to a severe perturbation of the normal cell cycle distribution pattern. Whereas no substantial changes in c-myc mRNA levels and p21, PCNA, cdc2, and CDK2 protein levels were noted in PMEA-treated K562 cells, there was a marked accumulation of cyclin A and, most strikingly, cyclins E and B1. A similar picture of cell cycle deregulation was also observed in PMEA-exposed human myeloid THP-1 cells. However, in contrast to the strong differentiation-inducing activity of PMEA in K562 cells, the drug completely failed to induce monocytic maturation of human myeloid THP-1 cells. On the contrary, THP-1 cells underwent apoptotic cell death in the presence of PMEA, as demonstrated by prelytic, intracellular DNA fragmentation and the binding of annexin V to the cell surface. We hypothesize that, depending on the nature of the tumor cell line, PMEA triggers a process of either differentiation or apoptosis by the uncoupling of normally integrated cell cycle processes through inhibition of DNA replication during the S phase.
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PMID:9-(2-Phosphonylmethoxyethyl)adenine induces tumor cell differentiation or cell death by blocking cell cycle progression through the S phase. 1039 5

Oxidized low density lipoproteins (oxLDLs) and activated T lymphocytes are present in early atherosclerotic plaques. It has been shown that oxLDLs are cytotoxic to cultured vascular cells but their possible toxic action on T lymphocytes has not been described. Peripheral blood lymphocytes from healthy individuals were stimulated in vitro with the polyclonal activator phytohemagglutinin and treated with various doses of native and mildly oxidized LDLs. Low doses of oxLDLs inhibited cell growth and DNA synthesis after 48 h culture and at 200 microg apoB/ml we observed a loss of cell viability. Dead cells did not exhibit significant increase of alteration of membrane integrity (i.e., necrosis) but showed chromatin fragmentation evaluated by DNA staining with 4', 6-diamidino-2-phenylindole and propidium iodide. This fragmentation increased with TBARS and hydroperoxide levels. The expression of early apoptosis marker Apo2.7 rose among the CD3(+) T-cell population. In addition, morphological analysis showed apoptotic features (cell shrinking, nucleus condensation, and fragmentation). Study of phosphatidylserine expression using Annexin V confirmed that oxLDLs induced apoptosis in activated lymphocytes. In the Jurkat T-cell line cultured with oxLDLs, apoptotic morphological changes (condensation and nucleus fragmentation) were observed and they were accompanied by DNA fragmentation visualized by propidium iodide staining and electrophoresis showing apoptotic ladder. These results demonstrate that mildly oxidized LDLs induce apoptosis in a part of activated and proliferating T cells. T-lymphocyte apoptosis induction in atherosclerotic lesions might contribute to the development of an inappropriate local T cell response.
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PMID:Oxidized low density lipoproteins induce apoptosis in PHA-activated peripheral blood mononuclear cells and in the Jurkat T-cell line. 1039 5


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